WorldWideScience

Sample records for particle levels aboard

  1. Determination of polar cusp position by low-energy particle measurements made aboard AUREOLE satellite

    International Nuclear Information System (INIS)

    Gladyshev, V.A.; Jorjio, M.V.; Shuiskaya, F.K.; Crasnier, J.; Sauvaud, J.A.

    1974-01-01

    The Franco-Soviet experiment ARCAD, launched aboard the satellite AUREOLE December 27, 1971, has verified the existence of a particle penetration from the transition zone up to ionospheric altitudes across the polar cusp. The polar cusp is characterized by proton fluxes >10 7 particles/(cm 2 .s.sr.KeV) at 0.5KeV, with energy spectra similar to those in the transition zone. The position and form of the polar cusp are studied from measurements of protons in the range 0.4 to 30KeV during geomagnetically quiet periods (Kp [fr

  2. In situ energetic particle observations at comet Halley recorded by instrumentation aboard the Giotto and Vega 1 missions

    Energy Technology Data Exchange (ETDEWEB)

    McKenna-Lawlor, S.; Daly, P.; Kirsch, E.; Wilken, B.; O' Sullivan, D.; Thompson, A.; Kecskemety, K.; Somogyi, A.; Coates, A.

    1989-04-01

    Three important observations recorded in the energetic particle data secured at Halley's comet during March 1986 are reviewed. These include (a) quasi periodic variations of cometary ion fluxes observed inbound and outbound by both the EPONA instrument aboard Giotto and by the Tunde-M instrument aboard Vega 1. A possible explanation of the results in terms of a spin modulation of the outgassing rate of the nucleus is discussed; (b) by combining the EPONA data with JPA-IIS data it is possible to infer that the ion fluxes measured at encounter by EPONA were of the water group. These particles displayed energies in excess of those attained by the pick-up process acting alone. Comparisons between energy spectra prepared using the composite observational data and, corresponding, theoretically derived plots suggest that, downstream of the shock (inbound), stochastic (second-order-Fermi) acceleration may have contributed to energizing the particles; (c) large fluxes of electrons (E>300keV) and ions (E>3.5 MeV) were unexpectedly recorded by EPONA in the magnetic cavity. The observed enhancements (up to approximately three orders of magnitude) appear to be cometary in origin.

  3. In situ energetic particle observations at comet Halley recorded by instrumentation aboard the Giotto and Vega 1 missions

    International Nuclear Information System (INIS)

    McKenna-Lawlor, S.; Daly, P.; Kirsch, E.; Wilken, B.; O'Sullivan, D.; Thompson, A.; Kecskemety, K.; Somogyi, A.

    1989-01-01

    Three important observations recorded in the energetic particle data secured at Halley's comet during March 1986 are reviewed. These include (a) quasi periodic variations of cometary ion fluxes observed inbound and outbound by both the EPONA instrument aboard Giotto and by the Tunde-M instrument aboard Vega 1. A possible explanation of the results in terms of a spin modulation of the outgassing rate of the nucleus is discussed; (b) by combining the EPONA data with JPA-IIS data it is possible to infer that the ion fluxes measured at encounter by EPONA were of the water group. These particles displayed energies in excess of those attained by the pick-up process acting alone. Comparisons between energy spectra prepared using the composite observational data and, corresponding, theoretically derived plots suggest that, downstream of the shock (inbound), stochastic (second-order-Fermi) acceleration may have contributed to energizing the particles; (c) large fluxes of electrons (E>300keV) and ions (E>3.5 MeV) were unexpectedly recorded by EPONA in the magnetic cavity. The observed enhancements (up to approximately three orders of magnitude) appear to be cometary in origin

  4. Proton energy spectra during ground level enhancements as measured by EPHIN aboard SOHO

    Energy Technology Data Exchange (ETDEWEB)

    Heber, Bernd; Kuehl, Patrick; Klassen, Andreas; Dresing, Nina [Christian-Albrechts-Universitaet zu Kiel, 24118 Kiel (Germany); Gomez-Herrero, Raul [Universidad de Alcala (Spain)

    2016-07-01

    Ground Level Enhancements (GLEs) are solar energetic particle (SEP) events that are recorded by ground-based instrumentation. The energy of the particles is so high that they produce secondary particles in the Earth's atmosphere, i.e. protons and neutrons, which are detected as sudden increases in cosmic ray intensities measured by e.g. neutron monitors. Since the launch of SOHO in December 1995 the neutron monitor network recorded 16 GLEs. The Electron Proton Helium INstrument on board SOHO has been designed to measure protons and helium up to 53 MeV/nucleon as well as electrons up to 8.3 MeV. Above these energies, particles penetrate all detector elements and thus, a separation between different particle species becomes more complicated. Recently we developed a method that allows deriving the energy spectrum for penetrating protons up to more than 1 GeV. In this contribution we present the proton energy spectra and time profiles of above mentioned GLEs and compare them to previous measurements. Although there are differences of up to a factor two the overall shape of the energy spectra agree surprisingly well. Thus it has been demonstrated that EPHIN measurements are a valuable tool for understanding GLE.

  5. Single particle level scheme for alpha decay

    International Nuclear Information System (INIS)

    Mirea, M.

    1998-01-01

    The fine structure phenomenon in alpha decay was evidenced by Rosenblum. In this process the kinetic energy of the emitted particle has several determined values related to the structure of the parent and the daughter nucleus. The probability to find the daughter in a low lying state was considered strongly dependent on the spectroscopic factor defined as the square of overlap between the wave function of the parent in the ground state and the wave functions of the specific excited states of the daughter. This treatment provides a qualitative agreement with the experimental results if the variations of the penetrability between different excited states are neglected. Based on single particle structure during fission, a new formalism explained quantitatively the fine structure of the cluster decay. It was suggested that this formalism can be applied also to alpha decay. For this purpose, the first step is to construct the level scheme of this type of decay. Such a scheme, obtained with the super-asymmetric two-center potential, is plotted for the alpha decay of 223 Ra. It is interesting to note that, diabatically, the level with spin 3/2 emerging from 1i 11/2 (ground state of the parent) reaches an excited state of the daughter in agreement with the experiment. (author)

  6. All aboard!

    CERN Multimedia

    Anaïs Schaeffer

    2012-01-01

    Every year, CERN's surveyors take detailed measurements to check the alignment of the LHC components. This year, from 16 to 18 January, they took some of those measurements for the first time using a brand-new remotely controlled train in one of the long straight sections.   From left to right: Thierry Feniet, Patrick Bestmann and Cédric Charrondière in the arms of the measuring wagon. This train doesn’t take people, it takes pictures. Its purpose? To save CERN’s surveyors from having to take the alignment measurements manually, particularly in areas where operators are subject to constraints due to radioactivity (in line with the ALARA principle of keeping radiation exposure to a level that is “as low as reasonably achievable”). The surveyors’ train, over four years in development, is the joint brain-child of several groups from the EN and BE Departments. The result is a state-of-the-art device which, as Thierr...

  7. Hexagon POPE: effective particles and tree level resummation

    Energy Technology Data Exchange (ETDEWEB)

    Córdova, Lucía [Perimeter Institute for Theoretical Physics,Waterloo, Ontario N2L 2Y5 (Canada); Department of Physics and Astronomy & Guelph-Waterloo Physics Institute,University of Waterloo,Waterloo, Ontario N2L 3G1 (Canada)

    2017-01-12

    We present the resummation of the full Pentagon Operator Product Expansion series of the hexagon Wilson loop in planar N=4 SYM at tree level. We do so by considering the one effective particle states formed by a fundamental flux tube excitation and an arbitrary number of the so called small fermions which are then integrated out. We derive the one effective particle measures at finite coupling. By evaluating these measures at tree level and summing over all one effective particle states we reproduce the full 6 point tree level amplitude.

  8. UARS Particle Environment Monitor (PEM) Level 3TP V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Particle Environment Monitor (PEM) Level 3TP data product consists of daily, 65.536 second and 2.048 interval time-ordered, vertical profiles of electron and...

  9. On Adiabatic Processes at the Elementary Particle Level

    OpenAIRE

    A, Michaud

    2016-01-01

    Analysis of adiabatic processes at the elementary particle level and of the manner in which they correlate with the principle of conservation of energy, the principle of least action and entropy. Analysis of the initial and irreversible adiabatic acceleration sequence of newly created elementary particles and its relation to these principles. Exploration of the consequences if this first initial acceleration sequence is not subject to the principle of conservation.

  10. Development of low level alpha particle counting system

    International Nuclear Information System (INIS)

    Minobe, Masao; Kondo, Hiraku; Chinuki, Takashi; Hirano, Hiromichi

    1987-01-01

    Much attention has been paid to the trace analysis of uranium and thorium contained in the base material of LSI or VLSI, since the so-called ''soft-error'' of the memory device was known to be due to alpha particles emitted from these radioactive elements. We have developed an apparatus to meet the needs of estimating such a very small quantity of U and Th of the level of ppb, by directly counting alpha particles using a gas-flow type proportional counter. This method requires no sophisticated analytical skill, and the accuracy of the result is satisfactory. The instrumentation and some application of this apparatus are described. (author)

  11. Catalyst Particles for Fluid Catalytic Cracking Visualized at the Individual Particle Level by Micro-Spectroscopy

    NARCIS (Netherlands)

    Buurmans, I.L.C.

    2011-01-01

    In this PhD research the investigation of the reactivity and acidity of Fluid Catalytic Cracking (FCC) catalysts at the level of an individual catalyst particles is described. A range of micro-spectroscopic techniques has been applied to visualize both the active zeolite component within the

  12. Aboard the Space Shuttle.

    Science.gov (United States)

    Steinberg, Florence S.

    This 32-page pamphlet contains color photographs and detailed diagrams which illustrate general descriptive comments about living conditions aboard the space shuttle. Described are details of the launch, the cabin, the condition of weightlessness, food, sleep, exercise, atmosphere, personal hygiene, medicine, going EVA (extra-vehicular activity),…

  13. Single particle level density in a finite depth potential well

    International Nuclear Information System (INIS)

    Shlomo, S.; Kolomietz, V.M.; Dejbakhsh, H.

    1997-01-01

    We consider the single particle level density g(ε) of a realistic finite depth potential well, concentrating on the continuum (ε>0) region. We carry out quantum-mechanical calculations of the partial level density g l (ε), associated with a well-defined orbital angular momentum l≤40, using the phase-shift derivative method and the Greens-function method and compare the results with those obtained using the Thomas-Fermi approximation. We also numerically calculate g(ε) as a l sum of g l (ε) up to a certain value of scr(l) max ≤40 and determine the corresponding smooth level densities using the Strutinsky smoothing procedure. We demonstrate, in accordance with Levinson close-quote s theorem, that the partial contribution g l (ε) to the single particle level density from continuum states has positive and negative values. However, g(ε) is nonnegative. We also point out that this is not the case for an energy-dependent potential well. copyright 1997 The American Physical Society

  14. Predictable Particle Engineering: Programming the Energy Level, Carrier Generation, and Conductivity of Core-Shell Particles.

    Science.gov (United States)

    Yuan, Conghui; Wu, Tong; Mao, Jie; Chen, Ting; Li, Yuntong; Li, Min; Xu, Yiting; Zeng, Birong; Luo, Weiang; Yu, Lingke; Zheng, Gaofeng; Dai, Lizong

    2018-06-20

    Core-shell structures are of particular interest in the development of advanced composite materials as they can efficiently bring different components together at nanoscale. The advantage of this structure greatly relies on the crucial design of both core and shell, thus achieving an intercomponent synergistic effect. In this report, we show that decorating semiconductor nanocrystals with a boronate polymer shell can easily achieve programmable core-shell interactions. Taking ZnO and anatase TiO 2 nanocrystals as inner core examples, the effective core-shell interactions can narrow the band gap of semiconductor nanocrystals, change the HOMO and LUMO levels of boronate polymer shell, and significantly improve the carrier density of core-shell particles. The hole mobility of core-shell particles can be improved by almost 9 orders of magnitude in comparison with net boronate polymer, while the conductivity of core-shell particles is at most 30-fold of nanocrystals. The particle engineering strategy is based on two driving forces: catechol-surface binding and B-N dative bonding and having a high ability to control and predict the shell thickness. Also, this approach is applicable to various inorganic nanoparticles with different components, sizes, and shapes.

  15. Charged particles radiation measurements with Liulin-MO dosimeter of FREND instrument aboard ExoMars Trace Gas Orbiter during the transit and in high elliptic Mars orbit

    Science.gov (United States)

    Semkova, Jordanka; Koleva, Rositza; Benghin, Victor; Dachev, Tsvetan; Matviichuk, Yuri; Tomov, Borislav; Krastev, Krasimir; Maltchev, Stephan; Dimitrov, Plamen; Mitrofanov, Igor; Malahov, Alexey; Golovin, Dmitry; Mokrousov, Maxim; Sanin, Anton; Litvak, Maxim; Kozyrev, Andrey; Tretyakov, Vladislav; Nikiforov, Sergey; Vostrukhin, Andrey; Fedosov, Fedor; Grebennikova, Natalia; Zelenyi, Lev; Shurshakov, Vyacheslav; Drobishev, Sergey

    2018-03-01

    ExoMars is a joint ESA-Rosscosmos program for investigating Mars. Two missions are foreseen within this program: one consisting of the Trace Gas Orbiter (TGO), that carries scientific instruments for the detection of trace gases in the Martian atmosphere and for the location of their source regions, plus an Entry, Descent and landing demonstrator Module (EDM), launched on March 14, 2016; and the other, featuring a rover and a surface platform, with a launch date of 2020. On October 19, 2016 TGO was inserted into high elliptic Mars' orbit. The dosimetric telescope Liulin-MO for measuring the radiation environment onboard the ExoMars 2016 TGO is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present first results from measurements of the charged particle fluxes, dose rates, Linear Energy Transfer (LET) spectra and estimation of dose equivalent rates in the interplanetary space during the cruise of TGO to Mars and first results from dosimetric measurements in high elliptic Mars' orbit. A comparison is made with the dose rates obtained by RAD instrument onboard Mars Science Laboratory during the cruise to Mars in 2011-2012 and with the Galactic Cosmic Rays (GCR) count rates provided by other particle detectors currently in space. The average measured dose rate in Si from GCR during the transit to Mars for the period April 22-September 15, 2016 is 372 ± 37 μGy d-1 and 390 ± 39 μGy d-1 in two perpendicular directions. The dose equivalent rate from GCR for the same time period is about 2 ± 0.3 mSv d-1. This is in good agreement with RAD results for radiation dose rate in Si from GCR in the interplanetary space, taking into account the different solar activity during the measurements of both instruments. About 10% increase of the dose rate, and 15% increase of the dose equivalent rate for 10.5 months flight is observed. It is due to the increase of Liulin-MO particle fluxes for that period and corresponds to the overall GCR intensity

  16. Polycrystalline CVD diamond device level modeling for particle detection applications

    Science.gov (United States)

    Morozzi, A.; Passeri, D.; Kanxheri, K.; Servoli, L.; Lagomarsino, S.; Sciortino, S.

    2016-12-01

    Diamond is a promising material whose excellent physical properties foster its use for radiation detection applications, in particular in those hostile operating environments where the silicon-based detectors behavior is limited due to the high radiation fluence. Within this framework, the application of Technology Computer Aided Design (TCAD) simulation tools is highly envisaged for the study, the optimization and the predictive analysis of sensing devices. Since the novelty of using diamond in electronics, this material is not included in the library of commercial, state-of-the-art TCAD software tools. In this work, we propose the development, the application and the validation of numerical models to simulate the electrical behavior of polycrystalline (pc)CVD diamond conceived for diamond sensors for particle detection. The model focuses on the characterization of a physically-based pcCVD diamond bandgap taking into account deep-level defects acting as recombination centers and/or trap states. While a definite picture of the polycrystalline diamond band-gap is still debated, the effect of the main parameters (e.g. trap densities, capture cross-sections, etc.) can be deeply investigated thanks to the simulated approach. The charge collection efficiency due to β -particle irradiation of diamond materials provided by different vendors and with different electrode configurations has been selected as figure of merit for the model validation. The good agreement between measurements and simulation findings, keeping the traps density as the only one fitting parameter, assesses the suitability of the TCAD modeling approach as a predictive tool for the design and the optimization of diamond-based radiation detectors.

  17. Polycrystalline CVD diamond device level modeling for particle detection applications

    International Nuclear Information System (INIS)

    Morozzi, A.; Passeri, D.; Kanxheri, K.; Servoli, L.; Lagomarsino, S.; Sciortino, S.

    2016-01-01

    Diamond is a promising material whose excellent physical properties foster its use for radiation detection applications, in particular in those hostile operating environments where the silicon-based detectors behavior is limited due to the high radiation fluence. Within this framework, the application of Technology Computer Aided Design (TCAD) simulation tools is highly envisaged for the study, the optimization and the predictive analysis of sensing devices. Since the novelty of using diamond in electronics, this material is not included in the library of commercial, state-of-the-art TCAD software tools. In this work, we propose the development, the application and the validation of numerical models to simulate the electrical behavior of polycrystalline (pc)CVD diamond conceived for diamond sensors for particle detection. The model focuses on the characterization of a physically-based pcCVD diamond bandgap taking into account deep-level defects acting as recombination centers and/or trap states. While a definite picture of the polycrystalline diamond band-gap is still debated, the effect of the main parameters (e.g. trap densities, capture cross-sections, etc.) can be deeply investigated thanks to the simulated approach. The charge collection efficiency due to β -particle irradiation of diamond materials provided by different vendors and with different electrode configurations has been selected as figure of merit for the model validation. The good agreement between measurements and simulation findings, keeping the traps density as the only one fitting parameter, assesses the suitability of the TCAD modeling approach as a predictive tool for the design and the optimization of diamond-based radiation detectors.

  18. Probabilistic Teleportation of an Arbitrary Three-Level Two-Particle State and Classical Communication Cost

    Institute of Scientific and Technical Information of China (English)

    DAIHong-Yi; KUANGLe-Man; LICheng-Zu

    2005-01-01

    We propose a scheme to probabilistically teleport an unknown arbitrary three-level two-particle state by using two partial entangled two-particle states of three-level as the quantum channel. The classical communication cost required in the ideal probabilistic teleportation process is also calculated. This scheme can be directly generalized to teleport an unknown and arbitrary three-level K-particle state by using K partial entangled two-particle states of three-level as the quantum channel.

  19. Single Particle energy levels in ODD-A Nuclei

    International Nuclear Information System (INIS)

    Lasijo, R.S.

    1997-01-01

    Singe particle energies for atomic nuclei with odd-A number of nucleons, i.e. nuclei possessing odd number of protons or odd number of neutrons, were calculated based on Nilsson's theory, and then the diagrams were made. the energy diagram is in the from of plot of energies as function of deformations, entities identifying the deviations from the spherical shape. The energy calculations were done using FORTRAN 77 language of PC (Personal Computer) version with Microsoft Fortran Power Station compiler, which was then combined with WORD version 6.0 and EXCEL version 5.0 of WINDOWS WORKGROUP to make the plot

  20. Particle size and radionuclide levels in some west Cumbrian soils

    International Nuclear Information System (INIS)

    Livens, F.R.

    1988-01-01

    Four west Cumbrian soils of contrasting types, together with an estuarine silt sample, were separated into different particle size fractions by a combination of sieving and settling techniques. These sub-samples were analysed by quantitative gamma-ray spectrometry for several nuclides, principally 137 Cs, 106 Ru and 241 Am, followed by chemical separation and alpha spectrometric determination of 238,239,240 Pu. A simple empirical method of correction for differing sample sizes, and hence counting geometries, was developed for gamma spectrometry and found to give good results. The radionuclides were concentrated into the finer size fractions, with clay-sized ( 137 Cs from 3 to 35 times. The enhancement was greatest for all radionuclides in a sandy soil with a very low clay content (0.2% by weight) and it was found that, as the abundance of fine particles increased, so the concentration effect decreased. No evidence was found for a simple relationship between organic content and radionuclide activity, although the organic matter does have some effect. 17 refs.; 3 figs.; 6 tabs

  1. Analysis of filler particle levels and sizes in dental alginates

    Directory of Open Access Journals (Sweden)

    Hugo Lemes Carlo

    2010-06-01

    Full Text Available The aim of this study was to determine the inorganic filler fractions and sizes of commercially alginates. The inorganic particles volumetric fractions of five alginates - Jeltrate(J, Jeltrate Plus(JP, Jeltrate Chromatic Ortho(JC, Hydrogum(H and Ezact Krom(E were accessed by weighing a previously determined mass of each material in water before and after burning samples at 450 °C for 3 hours. Unsettled materials were soaked in acetone and chloroform and sputter-coated with gold for SEM evaluation of fillers' morphology and size. The results for the volumetric inorganic particle content were (%: J - 48.33, JP - 48.33, JC - 33.79, H - 37.55 and E - 40.55. The fillers presented a circular appearance with helical form and various perforations. Hydrogum fillers looked like cylindrical, perforated sticks. The mean values for fillers size were (μm: J - 12.91, JP - 13.67, JC - 13.44, E - 14.59 and H - 9 (diameter, 8.81 (length. The results of this study revealed differences in filler characteristics that could lead to different results when testing mechanical properties.

  2. On the evaluation of semiclassical nuclear many-particle many-hole level densities

    International Nuclear Information System (INIS)

    Blin, A.H.; Hiller, B.; Schuck, P.; Yannouleas, C.

    1985-10-01

    An exact general scheme is described to calculate the m-particle n-hole fermion level densities for an arbitrary single particle Hamiltonian taking into account the Pauli exclusion principle. This technique is applied to obtain level densities of the three dimensional isotropic harmonic oscillator semiclassically in the Thomas-Fermi approach. In addition, we study the l-particle l-hole level density of the Woods-Saxon potential. For the harmonic oscillator we analyze the temperature dependence of the linear response function and the influence of pairing correlations on the l-particle l-hole level density. Finally, a Taylor expansion method of the m-particle n-hole level densities is discussed

  3. Optimizing Low Light Level Imaging Techniques and Sensor Design Parameters using CCD Digital Cameras for Potential NASA Earth Science Research aboard a Small Satellite or ISS

    Data.gov (United States)

    National Aeronautics and Space Administration — For this project, the potential of using state-of-the-art aerial digital framing cameras that have time delayed integration (TDI) to acquire useful low light level...

  4. Occupational accidents aboard merchant ships

    DEFF Research Database (Denmark)

    Hansen, H.L.; Nielsen, D.; Frydenberg, Morten

    2002-01-01

    Objectives: To investigate the frequency, circumstances, and causes of occupational accidents aboard merchant ships in international trade, and to identify risk factors for the occurrence of occupational accidents as well as dangerous working situations where possible preventive measures may...... be initiated. Methods: The study is a historical follow up on occupational accidents among crew aboard Danish merchant ships in the period 1993–7. Data were extracted from the Danish Maritime Authority and insurance data. Exact data on time at risk were available. Results: A total of 1993 accidents were...... aboard. Relative risks for notified accidents and accidents causing permanent disability of 5% or more were calculated in a multivariate analysis including ship type, occupation, age, time on board, change of ship since last employment period, and nationality. Foreigners had a considerably lower recorded...

  5. Effect of corn silage particle size and level of soybean oil on ruminal ...

    African Journals Online (AJOL)

    To determine the effects of two corn silage particle size (coarse particle with geometric mean of 5.83 ± 2.47 mm and fine particle with geometric mean of 4.74 ± 2.74 mm) and two levels of soybean oil (0 and 4% of DM) on ruminal mat composition, distribution and consistency, four two years fistulated ruminant Zel ewes (BW ...

  6. Schemes for Probabilistic Teleportation of an Unknown Three-Particle Three-Level Entangled State

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, two schemes for teleporting an unknown three-particle three-level entangled state are proposed. In the first scheme, two partial three-particle three-level entangled states are used as the quantum channels, while in the second scheme, three two-particle three-level non-maximally entangled states are employed as quantum channels.It is shown that the teleportation can be successfully realized with certain probability, for both two schemes, if a receiver adopts some appropriate unitary transformations. It is shown also that the successful probabilities of these two schemes are different.

  7. Probabilistic Teleportation of Multi-particle d-Level Quantum State

    Institute of Scientific and Technical Information of China (English)

    CAO Min; ZHU Shi-Qun

    2005-01-01

    The general scheme for teleportation of a multi-particle d-level quantum state is presented when m pairs of partially entangled particles are utilized as quantum channels. The probabilistic teleportation can be achieved with a successful probability of d-1∏N=0(CN0)2/dM,which is determined by the smallest coefficients of each entangled channels.

  8. Localization and force analysis at the single virus particle level using atomic force microscopy

    International Nuclear Information System (INIS)

    Liu, Chih-Hao; Horng, Jim-Tong; Chang, Jeng-Shian; Hsieh, Chung-Fan; Tseng, You-Chen; Lin, Shiming

    2012-01-01

    Highlights: ► Localization of single virus particle. ► Force measurements. ► Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  9. Indoor particle levels in small- and medium-sized commercial buildings in California.

    Science.gov (United States)

    Wu, Xiangmei May; Apte, Michael G; Bennett, Deborah H

    2012-11-20

    This study monitored indoor and outdoor particle concentrations in 37 small and medium commercial buildings (SMCBs) in California with three buildings sampled on two occasions, resulting in 40 sampling days. Sampled buildings included offices, retail establishments, restaurants, dental offices, and hair salons, among others. Continuous measurements were made for both ultrafine and fine particulate matter as well as black carbon inside and outside of the building. Integrated PM(2.5), PM(2.5-10), and PM(10) samples were also collected inside and outside the building. The majority of the buildings had indoor/outdoor (I/O) particle concentration ratios less than 1.0, indicating that contributions from indoor sources are less than removal of outdoor particles. However, some of the buildings had I/O ratios greater than 1, indicating significant indoor particle sources. This was particularly true of restaurants, hair salons, and dental offices. The infiltration factor was estimated from a regression analysis of indoor and outdoor concentrations for each particle size fraction, finding lower values for ultrafine and coarse particles than for submicrometer particles, as expected. The I/O ratio of black carbon was used as a relative measure of the infiltration factor of particles among buildings, with a geometric mean of 0.62. The contribution of indoor sources to indoor particle levels was estimated for each building.

  10. Summertime observations of elevated levels of ultrafine particles in the high Arctic marine boundary layer

    Science.gov (United States)

    Burkart, Julia; Willis, Megan D.; Bozem, Heiko; Thomas, Jennie L.; Law, Kathy; Hoor, Peter; Aliabadi, Amir A.; Köllner, Franziska; Schneider, Johannes; Herber, Andreas; Abbatt, Jonathan P. D.; Leaitch, W. Richard

    2017-05-01

    Motivated by increasing levels of open ocean in the Arctic summer and the lack of prior altitude-resolved studies, extensive aerosol measurements were made during 11 flights of the NETCARE July 2014 airborne campaign from Resolute Bay, Nunavut. Flights included vertical profiles (60 to 3000 m above ground level) over open ocean, fast ice, and boundary layer clouds and fogs. A general conclusion, from observations of particle numbers between 5 and 20 nm in diameter (N5 - 20), is that ultrafine particle formation occurs readily in the Canadian high Arctic marine boundary layer, especially just above ocean and clouds, reaching values of a few thousand particles cm-3. By contrast, ultrafine particle concentrations are much lower in the free troposphere. Elevated levels of larger particles (for example, from 20 to 40 nm in size, N20 - 40) are sometimes associated with high N5 - 20, especially over low clouds, suggestive of aerosol growth. The number densities of particles greater than 40 nm in diameter (N > 40) are relatively depleted at the lowest altitudes, indicative of depositional processes that will lower the condensation sink and promote new particle formation. The number of cloud condensation nuclei (CCN; measured at 0.6 % supersaturation) are positively correlated with the numbers of small particles (down to roughly 30 nm), indicating that some fraction of these newly formed particles are capable of being involved in cloud activation. Given that the summertime marine Arctic is a biologically active region, it is important to better establish the links between emissions from the ocean and the formation and growth of ultrafine particles within this rapidly changing environment.

  11. New particle formation at ground level and in the vertical column over the Barcelona area

    Science.gov (United States)

    Minguillón, M. C.; Brines, M.; Pérez, N.; Reche, C.; Pandolfi, M.; Fonseca, A. S.; Amato, F.; Alastuey, A.; Lyasota, A.; Codina, B.; Lee, H.-K.; Eun, H.-R.; Ahn, K.-H.; Querol, X.

    2015-10-01

    The vertical profiles (up to 975 m a.s.l.) of ultrafine and micronic particles across the planetary boundary layer and the free troposphere over a Mediterranean urban environment were investigated. Measurements were carried out using a tethered balloon equipped with a miniaturized condensation particle counter, a miniaturized optical particle counter, a micro-aethalometer, a rotating impactor, and meteorological instrumentation. Simultaneous ground measurements were carried out at an urban and a regional background site. New particle formation episodes initiating in the urban area were observed under high insolation conditions. The precursors were emitted by the city and urban photochemically-activated nucleation occurred both at high atmospheric levels (tens to hundreds of meters) and at ground level. The new particle formation at ground level was limited by the high particulate matter concentrations recorded during the morning traffic rush hours that increase the condensation sink and prevent new particle formation, and therefore restricted to midday and early afternoon. The aloft new particle formation occurred earlier as the thermally ascending polluted air mass was diluted. The regional background was only affected from midday and early afternoon when sea and mountain breezes transported the urban air mass after particle growth. These events are different from most new particle formation events described in literature, characterized by a regionally originated nucleation, starting early in the morning in the regional background and persisting with a subsequent growth during a long period. An idealized and simplified model of the spatial and time occurrence of these two types of new particle formation episodes into, around and over the city was elaborated.

  12. Fermi level equilibration between colloidal lead and silver particles in aqueous solution

    International Nuclear Information System (INIS)

    Henglein, A.; Holzwarth, A.; Mulvaney, P.

    1992-01-01

    Colloidal solutions of lead and silver were mixed under the exclusion of air. The equilibration of the Fermi levels in the two different types of metal particles took place over a few days at room temperature. The equilibration took place by the transfer of lead atoms from lead to silver particles until the latter carried a lead mantle of one to two monolayers. This could be concluded from the observed changes in the optical spectrum of the silver particles. The results are discussed in terms of two mechanisms: (1) Pb atom transfer following heterocoagulation of the lead and silver particles and (2) electron transfer during Brownian encounters, followed by Pb 2+ desorption from the lead particles and subsequent Pb 2+ reductor on the silver particles carrying the transferred electrons. Traces of methylviologen, MV 2+ , in the solution drastically increase the rate of equilibration; this is explained by a relay mechanism in which electrons in the lead particles are first picked up by MV 2+ and are then transferred from MV + to the silver particles. 2 refs., 4 figs

  13. Localization and force analysis at the single virus particle level using atomic force microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Chih-Hao [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Horng, Jim-Tong [Department of Biochemistry, Chang Gung University, 259 Wen-Hwa First Road, Kweishan, Taoyuan 333, Taiwan (China); Chang, Jeng-Shian [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Hsieh, Chung-Fan [Graduate Institute of Biomedical Sciences, Chang Gung University, Kweishan, Taoyuan 333, Taiwan (China); Tseng, You-Chen [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Lin, Shiming, E-mail: til@ntu.edu.tw [Institute of Applied Mechanics, Nation Taiwan University, Roosevelt Road, Taipei 10617, Taiwan (China); Center for Optoelectronic Biomedicine, College of Medicine, Nation Taiwan University, 1-1 Jen-Ai Road, Taipei 10051, Taiwan (China)

    2012-01-06

    Highlights: Black-Right-Pointing-Pointer Localization of single virus particle. Black-Right-Pointing-Pointer Force measurements. Black-Right-Pointing-Pointer Force mapping. -- Abstract: Atomic force microscopy (AFM) is a vital instrument in nanobiotechnology. In this study, we developed a method that enables AFM to simultaneously measure specific unbinding force and map the viral glycoprotein at the single virus particle level. The average diameter of virus particles from AFM images and the specificity between the viral surface antigen and antibody probe were integrated to design a three-stage method that sets the measuring area to a single virus particle before obtaining the force measurements, where the influenza virus was used as the object of measurements. Based on the purposed method and performed analysis, several findings can be derived from the results. The mean unbinding force of a single virus particle can be quantified, and no significant difference exists in this value among virus particles. Furthermore, the repeatability of the proposed method is demonstrated. The force mapping images reveal that the distributions of surface viral antigens recognized by antibody probe were dispersed on the whole surface of individual virus particles under the proposed method and experimental criteria; meanwhile, the binding probabilities are similar among particles. This approach can be easily applied to most AFM systems without specific components or configurations. These results help understand the force-based analysis at the single virus particle level, and therefore, can reinforce the capability of AFM to investigate a specific type of viral surface protein and its distributions.

  14. Concentrations and size distributions of fine aerosol particles measured at roof level in urban zone

    Science.gov (United States)

    Despiau, S.; Croci, D.

    2007-05-01

    During the experimental Field Experiments to Constrain Models of Atmospheric Pollution and Transport of Emissions (ESCOMPTE) campaign in June-July 2001, concentrations and size distributions of fine particles (14-722 nm) were measured at roof level in downtown Marseille (France). Part of the campaign was dedicated to the study of aerosol behavior in relation to strong photochemical events (which were identified as "IOP" days) and their regional modeling. The analysis of the concentration variations and the evolution of average diurnal size distribution showed that an "IOP day" is not characterized by a specific concentration or its variation, nor by a specific evolution of the average size distribution. The morning traffic rush is detected at roof level by a net increase in particle concentration over the whole size range measured, indicating a production of ultrafine particles by the traffic but also the raising to roof level of particles of the accumulation mode. The increase is observed about 1 hour after the traffic peak at street level, which is characterized by strong increases in NOx and CO concentrations. The corresponding flux of particles at roof level has been estimated around 3 × 104 cm-2 s-1. A specific signature characterized by a strong and rapid burst of concentration (factor 2 to 4 in 15 min) of particles between 25 and 50 nm, independent of the traffic source, has been detected on six occasions during the campaign. These events occur systematically around noon, in cases of strong radiation, low relative humidity, and common wind direction. Despite the high-diameter value of these particles, it is suggested that they could result from a specific "secondary aerosol process" event involving ozone, biogenic, and/or anthropogenic gas precursors like iodine and VOCs.

  15. Impact of wood combustion on particle levels in a residential area in Denmark

    DEFF Research Database (Denmark)

    Glasius, M.; Ketzel, M.; Wåhlin, P.

    2006-01-01

    The influence of residential wood-combustion on local air quality was studied during two periods in 2002 and 2003/04 in a small rural town with widespread use of wood combustion for heating. During one 6-week winter period, particle levels (PM2.5) in the residential area were about 4 μg m-3 higher...... than at a nearby background site. This was comparable to the local traffic contribution observed at a busy street (about 70,000 vehicles per day) in the city of Copenhagen. The diurnal variation in the residential area showed increased particle levels (PM2.5) in the evening and night as expected from...... local heating sources. Particle size distributions showed highest volume concentrations of particles with diameters of 400-500 nm, and the diurnal variation of particle volume was similar to PM2.5. The particle measurements were supported by measurements of combustion gases in both the residential area...

  16. Relativistic corrections to one-particle neutron levels in the harmonic oscillator well

    International Nuclear Information System (INIS)

    Yanavichyus, A.I.

    1983-01-01

    Relativistic corrections to mass and potential energy for one-particle levels in the harmonic oscillator well are calculated in the first approximation of the perturbation theory. These corrections are, mainly negliqible, but they sharply increase with growth of the head and orbital quantum numbers. For the state 1s the relativistic correction is of the order of 0.01 MeV, and for 3p it is equal to 0.4 MeV. Thus, the relativistic correction for certain states approaches the energy of spin-orbital interactions and it should be taken into account in calculating the energy of one-particle levels

  17. A Case for Hypogravity Studies Aboard ISS

    Science.gov (United States)

    Paloski, William H.

    2014-01-01

    Future human space exploration missions being contemplated by NASA and other spacefaring nations include some that would require long stays upon bodies having gravity levels much lower than that of Earth. While we have been able to quantify the physiological effects of sustained exposure to microgravity during various spaceflight programs over the past half-century, there has been no opportunity to study the physiological adaptations to gravity levels between zero-g and one-g. We know now that the microgravity environment of spaceflight drives adaptive responses of the bone, muscle, cardiovascular, and sensorimotor systems, causing bone demineralization, muscle atrophy, reduced aerobic capacity, motion sickness, and malcoordination. All of these outcomes can affect crew health and performance, particularly after return to a one-g environment. An important question for physicians, scientists, and mission designers planning human exploration missions to Mars (3/8 g), the Moon (1/6 g), or asteroids (likely negligible g) is: What protection can be expected from gravitational levels between zero-g and one-g? Will crewmembers deconditioned by six months of microgravity exposure on their way to Mars experience continued deconditioning on the Martian surface? Or, will the 3/8 g be sufficient to arrest or even reverse these adaptive changes? The implications for countermeasure deployment, habitat accommodations, and mission design warrant further investigation into the physiological responses to hypogravity. It is not possible to fully simulate hypogravity exposure on Earth for other than transient episodes (e.g., parabolic flight). However, it would be possible to do so in low Earth orbit (LEO) using the centrifugal forces produced in a live-aboard centrifuge. As we're not likely to launch a rotating human spacecraft into LEO anytime in the near future, we could take advantage of rodent subjects aboard the ISS if we had a centrifuge that could accommodate the rodent

  18. Treatment of Electronic Energy Level Transition and Ionization Following the Particle-Based Chemistry Model

    Science.gov (United States)

    Liechty, Derek S.; Lewis, Mark

    2010-01-01

    A new method of treating electronic energy level transitions as well as linking ionization to electronic energy levels is proposed following the particle-based chemistry model of Bird. Although the use of electronic energy levels and ionization reactions in DSMC are not new ideas, the current method of selecting what level to transition to, how to reproduce transition rates, and the linking of the electronic energy levels to ionization are, to the author s knowledge, novel concepts. The resulting equilibrium temperatures are shown to remain constant, and the electronic energy level distributions are shown to reproduce the Boltzmann distribution. The electronic energy level transition rates and ionization rates due to electron impacts are shown to reproduce theoretical and measured rates. The rates due to heavy particle impacts, while not as favorable as the electron impact rates, compare favorably to values from the literature. Thus, these new extensions to the particle-based chemistry model of Bird provide an accurate method for predicting electronic energy level transition and ionization rates in gases.

  19. Adsorption of NO{sub 2} on carbon aerosols particles at the low ppb-level

    Energy Technology Data Exchange (ETDEWEB)

    Kalberer, M.; Ammann, M.; Baltensperger, U.; Gaeggeler, H.W. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    The adsorption of NO{sub 2} at the low ppb-level (3-40 ppb) on carbon aerosol particles was investigated. A sticking coefficient of about 2.10{sup -4} was found, similar to that in previous studies using radioactively labeled {sup 13}NO{sub 2}. (author) 2 figs., 2 refs.

  20. Learning about a Level Physics Students' Understandings of Particle Physics Using Concept Mapping

    Science.gov (United States)

    Gourlay, H.

    2017-01-01

    This paper describes a small-scale piece of research using concept mapping to elicit A level students' understandings of particle physics. Fifty-nine year 12 (16- and 17 year-old) students from two London schools participated. The exercise took place during school physics lessons. Students were instructed how to make a concept map and were…

  1. Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport

    International Nuclear Information System (INIS)

    Vukovic, B.; Radolic, V.; Lisjak, I.; Vekic, B.; Poje, M.; Planinic, J.

    2008-01-01

    When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or 10 B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb-Paris-Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 μSv/h and the TLD dosimeter registered the dose equivalent of 75 μSv or the average dose rate of 2.7 μSv/h; the neutron dosimeter gave the dose rate of 2.4 μSv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 μSv/h; the neutron dosimeter gave the dose rate of 2.5 μSv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data

  2. Some cosmic radiation dose measurements aboard flights connecting Zagreb Airport

    Energy Technology Data Exchange (ETDEWEB)

    Vukovic, B.; Radolic, V. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Lisjak, I. [Croatia Airlines, Zagreb (Croatia); Vekic, B. [Rudjer Boskovic Institute, Zagreb (Croatia); Poje, M. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia); Planinic, J. [Department of Physics, University of Osijek, Osijek, P.O. Box 125 (Croatia)], E-mail: planinic@ffos.hr

    2008-02-15

    When primary particles from space, mainly protons, enter the atmosphere, they produce interactions with air nuclei, and cosmic-ray showers are induced. The radiation field at aircraft altitude is complex, with different types of particles, mainly photons, electrons, positrons and neutrons, with a large energy range. The non-neutron component of cosmic radiation dose aboard A320 and ATR40 aircraft was measured with TLD-100 (LiF:Mg,Ti) detectors and the Mini 6100 semiconductor dosimeter; the neutron dose was measured with the neutron dosimeter consisted of LR-115 track detector and boron foil BN-1 or {sup 10}B converter. The estimated occupational effective dose for the aircraft crew (A320) working 500 h per year was 1.64 mSv. Another experiment was performed at the flights Zagreb-Paris-Buenos Aires and reversely, when one measured non-neutron cosmic radiation dose; for 26.7 h of flight, the MINI 6100 dosimeter gave an average dose rate of 2.3 {mu}Sv/h and the TLD dosimeter registered the dose equivalent of 75 {mu}Sv or the average dose rate of 2.7 {mu}Sv/h; the neutron dosimeter gave the dose rate of 2.4 {mu}Sv/h. In the same month, February 2005, a traveling to Japan (24-h-flight: Zagreb-Frankfurt-Tokyo and reversely) and the TLD-100 measurement showed the average dose rate of 2.4 {mu}Sv/h; the neutron dosimeter gave the dose rate of 2.5 {mu}Sv/h. Comparing dose rates of the non-neutron component (low LET) and the neutron one (high LET) of the radiation field at the aircraft flight level, we could conclude that the neutron component carried about 50% of the total dose, that was near other known data.

  3. Do microplastic particles affect Daphnia magna at the morphological, life history and molecular level?

    Directory of Open Access Journals (Sweden)

    Hannes K Imhof

    Full Text Available Microplastic particles are ubiquitous not only in marine but also in freshwater ecosystems. However, the impacts of microplastics, consisting of a large variety of synthetic polymers, on freshwater organisms remains poorly understood. We examined the effects of two polymer mixtures on the morphology, life history and on the molecular level of the waterflea Daphnia magna (three different clones. Microplastic particles of ~40 μm were supplied at a low concentration (1% of the food particles leading to an average of ~30 particles in the digestive tract which reflects a high microplastic contamination but still resembles a natural situation. Neither increased mortality nor changes on the morphological (body length, width and tail spine length or reproductive parameters were observed for adult Daphnia. The analyses of juvenile Daphnia revealed a variety of small and rather subtle responses of morphological traits (body length, width and tail spine length. For adult Daphnia, alterations in expression of genes related to stress responses (i.e. HSP60, HSP70 & GST as well as of other genes involved in body function and body composition (i.e. SERCA were observed already 48h after exposure. We anticipate that the adverse effects of microplastic might be influenced by many additional factors like size, shape, type and even age of the particles and that the rather weak effects, as detected in a laboratory, may lead to reduced fitness in a natural multi-stressor environment.

  4. Removal of Aerosol Particles Generated from Vitrification Process for High-Level Liquid Wastes

    OpenAIRE

    加藤 功

    1990-01-01

    The vitrification technology has been developed for the high-level liquid waste (HLLW) from reprocessing nuclear spent fuel in PNC. The removal performance of the aerosol particles generated from the melting process was studied in a nonradioactive full-scale mock-up test facility (MTF). The off-gas treatment system consists of submerged bed scrubber (SBS), venturi scrubber, NOx absorber, high efficiency mist eliminater (HEME). Deoomtamination factors (DFs) were derived from the mass ratio of ...

  5. Quantum private comparison with d-level single-particle states

    International Nuclear Information System (INIS)

    Yu, Chao-Hua; Guo, Gong-De; Lin, Song

    2013-01-01

    In this paper, a quantum private comparison protocol with d-level single-particle states is proposed. In the protocol, a semi-honest third party is introduced to help two participants compare the size relationship of their secrets without revealing them to any other people. It is shown that the protocol is secure in theory. Moreover, the security of the protocol in real circumstance is also discussed. (paper)

  6. Effect of energy level sequences and neutron–proton interaction on α-particle preformation probability

    International Nuclear Information System (INIS)

    Ismail, M.; Adel, A.

    2013-01-01

    A realistic density-dependent nucleon–nucleon (NN) interaction with finite-range exchange part which produces the nuclear matter saturation curve and the energy dependence of the nucleon–nucleus optical model potential is used to calculate the preformation probability, S α , of α-decay from different isotones with neutron numbers N=124,126,128,130 and 132. We studied the variation of S α with the proton number, Z, for each isotone and found the effect of neutron and proton energy levels of parent nuclei on the behavior of the α-particle preformation probability. We found that S α increases regularly with the proton number when the proton pair in α-particle is emitted from the same level and the neutron level sequence is not changed during the Z-variation. In this case the neutron–proton (n–p) interaction of the two levels, contributing to emission process, is too small. On the contrary, if the proton or neutron level sequence is changed during the emission process, S α behaves irregularly, the irregular behavior increases if both proton and neutron levels are changed. This behavior is accompanied by change or rapid increase in the strength of n–p interaction

  7. Alpha particle emission as a probe of the level density in highly excited A∼200 nuclei

    International Nuclear Information System (INIS)

    Fabris, D.; Fioretto, E.; Viesti, G.; Cinausero, M.; Gelli, N.; Hagel, K.; Lucarelli, F.; Natowitz, J.B.; Nebbia, G.; Prete, G.; Wada, R.

    1994-01-01

    The alpha particle emission from 90 to 140 MeV 19 F+ 181 Ta fusion-evaporation reactions has been studied. The comparisons of the experimental spectral shapes and multiplicities with statistical model predictions indicate a need to use an excitation energy dependent level-density parameter a=A/K in which K increases with excitation energy. This increase is more rapid than that in lower mass nuclei. The effect of this change in level density on the prescission multiplicities in fission is significant

  8. Particle count monitoring of reverse osmosis water treatment for removal of low-level radionuclides

    International Nuclear Information System (INIS)

    Moritz, E.J.; Hoffman, C.R.; Hergert, T.R.

    1995-01-01

    Laser diode particle counting technology and analytical measurements were used to evaluate a pilot-scale reverse osmosis (RO) water treatment system for removal of particulate matter and sub-picocurie low-level radionuclides. Stormwater mixed with Waste Water Treatment Plant (WWTP) effluent from the Rocky Flats Environmental Technology Site (RFETS), formerly a Department of Energy (DOE) nuclear weapons production facility, were treated. No chemical pretreatment of the water was utilized during this study. The treatment system was staged as follows: multimedia filtration, granular activated carbon adsorption, hollow tube ultrafiltration, and reverse osmosis membrane filtration. Various recovery rates and two RO membrane models were tested. Analytical measurements included total suspended solids (TSS), total dissolved solids (TDS), gross alpha (α) and gross beta (β) activity, uranium isotopes 233/234 U and 238 U, plutonium 239/240 Pu, and americium 241 Am. Particle measurement between 1--150 microns (μ) included differential particle counts (DPC), and total particle counts (TPC) before and after treatment at various sampling points throughout the test. Performance testing showed this treatment system produced a high quality effluent in clarity and purity. Compared to raw water levels, TSS was reduced to below detection of 5 milligrams per liter (mg/L) and TDS reduced by 98%. Gross α was essentially removed 100%, and gross β was reduced an average of 94%. Uranium activity was reduced by 99%. TPC between 1-150μ were reduced by an average 99.8% to less than 1,000 counts per milliliter (mL), similar in purity to a good drinking water treatment plant. Raw water levels of 239/240 Pu and 241 Am were below reliable quantitation limits and thus no removal efficiencies could be determined for these species

  9. An Alternative Derivation of the Energy Levels of the "Particle on a Ring" System

    Science.gov (United States)

    Vincent, Alan

    1996-10-01

    All acceptable wave functions must be continuous mathematical functions. This criterion limits the acceptable functions for a particle in a linear 1-dimensional box to sine functions. If, however, the linear box is bent round into a ring, acceptable wave functions are those which are continuous at the 'join'. On this model some acceptable linear functions become unacceptable for the ring and some unacceptable cosine functions become acceptable. This approach can be used to produce a straightforward derivation of the energy levels and wave functions of the particle on a ring. These simple wave mechanical systems can be used as models of linear and cyclic delocalised systems such as conjugated hydrocarbons or the benzene ring. The promotion energy of an electron can then be used to calculate the wavelength of absorption of uv light. The simple model gives results of the correct order of magnitude and shows that, as the chain length increases, the uv maximum moves to longer wavelengths, as found experimentally.

  10. Design of shared unit-dose drug distribution network using multi-level particle swarm optimization.

    Science.gov (United States)

    Chen, Linjie; Monteiro, Thibaud; Wang, Tao; Marcon, Eric

    2018-03-01

    Unit-dose drug distribution systems provide optimal choices in terms of medication security and efficiency for organizing the drug-use process in large hospitals. As small hospitals have to share such automatic systems for economic reasons, the structure of their logistic organization becomes a very sensitive issue. In the research reported here, we develop a generalized multi-level optimization method - multi-level particle swarm optimization (MLPSO) - to design a shared unit-dose drug distribution network. Structurally, the problem studied can be considered as a type of capacitated location-routing problem (CLRP) with new constraints related to specific production planning. This kind of problem implies that a multi-level optimization should be performed in order to minimize logistic operating costs. Our results show that with the proposed algorithm, a more suitable modeling framework, as well as computational time savings and better optimization performance are obtained than that reported in the literature on this subject.

  11. Weiss oscillations and particle-hole symmetry at the half-filled Landau level

    Science.gov (United States)

    Cheung, Alfred K. C.; Raghu, S.; Mulligan, Michael

    2017-06-01

    Particle-hole symmetry in the lowest Landau level of the two-dimensional electron gas requires the electrical Hall conductivity to equal ±e2/2 h at half filling. We study the consequences of weakly broken particle-hole symmetry for magnetoresistance oscillations about half filling in the presence of an applied periodic one-dimensional electrostatic potential using the Dirac composite fermion theory proposed by Son [Son, Phys. Rev. X 5, 031027 (2015), 10.1103/PhysRevX.5.031027]. At fixed electron density, the oscillation minima are asymmetrically biased towards higher magnetic fields, while at fixed magnetic field the oscillations occur symmetrically as the electron density is varied about half filling. We find an approximate "sum rule" obeyed for all pairs of oscillation minima that can be tested in experiment. The locations of the magnetoresistance oscillation minima for the composite fermion theory of Halperin, Lee, and Read (HLR) and its particle-hole conjugate agree exactly. Within the current experimental resolution, the locations of the oscillation minima produced by the Dirac composite fermion coincide with those of HLR. These results may indicate that all three composite fermion theories describe the same long-wavelength physics.

  12. Pairing in the BCS and LN approximations using continuum single particle level density

    International Nuclear Information System (INIS)

    Id Betan, R.M.; Repetto, C.E.

    2017-01-01

    Understanding the properties of drip line nuclei requires to take into account the correlations with the continuum spectrum of energy of the system. This paper has the purpose to show that the continuum single particle level density is a convenient way to consider the pairing correlation in the continuum. Isospin mean-field and isospin pairing strength are used to find the Bardeen–Cooper–Schrieffer (BCS) and Lipkin–Nogami (LN) approximate solutions of the pairing Hamiltonian. Several physical properties of the whole chain of the Tin isotope, as gap parameter, Fermi level, binding energy, and one- and two-neutron separation energies, were calculated and compared with other methods and with experimental data when they exist. It is shown that the use of the continuum single particle level density is an economical way to include explicitly the correlations with the continuum spectrum of energy in large scale mass calculation. It is also shown that the computed properties are in good agreement with experimental data and with more sophisticated treatment of the pairing interaction.

  13. Delayed Proton Emission in the A=70 Region, a Strobe for Level Density and Particle Width

    CERN Multimedia

    2002-01-01

    The delayed particle emission, which is a characteristic signature of the most exotic nuclei decay, provides a wide variety of spectroscopic information among which level density, and gives in some cases access to selected microscopic structures. In regard to these two aspects the $\\beta^+$-EC delayed proton emission in the A=70 neutron deficient mass region is of special interest to be investigated. Indeed, in this area located close to the proton drip line and along the N=Z line, the delayed proton emission constitutes an access to level density in the Q$_{EC}$-S$_p$ window of the emitting nucleus. Moreover, the unbound states populated by the EC process are expected to exhibit lifetimes in the vicinity of the K electronic shell filling time ($\\tau\\!\\sim\\!2\\times10^{-16}$s) and so the particle widths can be reached via proton X-ray coincidence measurements (PXCT). From theoretical approaches strongly deformed low-spin proton unbound levels which may be populated in the T$_Z$ = 1/2 precursors decay are predi...

  14. Nuclear and Particle Physics Simulations: The Consortium of Upper-Level Physics Software

    Science.gov (United States)

    Bigelow, Roberta; Moloney, Michael J.; Philpott, John; Rothberg, Joseph

    1995-06-01

    The Consortium for Upper Level Physics Software (CUPS) has developed a comprehensive series of Nine Book/Software packages that Wiley will publish in FY `95 and `96. CUPS is an international group of 27 physicists, all with extensive backgrounds in the research, teaching, and development of instructional software. The project is being supported by the National Science Foundation (PHY-9014548), and it has received other support from the IBM Corp., Apple Computer Corp., and George Mason University. The Simulations being developed are: Astrophysics, Classical Mechanics, Electricity & Magnetism, Modern Physics, Nuclear and Particle Physics, Quantum Mechanics, Solid State, Thermal and Statistical, and Wave and Optics.

  15. Inversion of single-particle levels in nuclear Hartree-Fock and Brueckner-HF calculations with broken symmetry

    International Nuclear Information System (INIS)

    Becker, R.L.; Svenne, J.P.

    1975-12-01

    Energy levels of states connected by a symmetry of the Hamiltonian normally should be degenerate. In self-consistent field theories, when only one of a pair of single-particle levels connected by a symmetry of the full Hamiltonian is occupied, the degeneracy is split and the unoccupied level often lies below the occupied one. Inversions of neutron-proton (charge) and time-reversal doublets in odd nuclei, charge doublets in even nuclei with a neutron excess, and spin-orbit doublets in spherical configurations with spin-unsaturated shells are examined. The origin of the level inversion is investigated, and the following explanation offered. Unoccupied single-particle levels, from a calculation in an A-particle system, should be interpreted as levels of the (A + 1)-particle system. When the symmetry-related level, occupied in the A-particle system, is also calculated in the (A + 1)-particle system it is degenerate with or lies lower than the other. That is, when both levels are calculated in the (A + 1)-particle system, they are not inverted. It is demonstrated that the usual prescription to occupy the lowest-lying orbitals should be modified to refer to the single-particle energies calculated in the (A + 1)- or the (A - 1)-particle system. This observation is shown to provide a justification for avoiding an oscillation of occupancy between symmetry-related partners in successive iterations leading to a self-consistency. It is pointed out that two degenerate determinants arise from occupying one or the other partner of an initially degenerate pair of levels and then iterating to self-consistency. The existence of the degenerate determinants indicates the need for introducing correlations, either by mixing the two configurations or by allowing additional symmetry-breaking (resulting in a more highly deformed non-degenerate configuration). 2 figures, 3 tables, 43 references

  16. Investigation of electrically-active deep levels in single-crystalline diamond by particle-induced charge transient spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Kada, W., E-mail: kada.wataru@gunma-u.ac.jp [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kambayashi, Y.; Ando, Y. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Onoda, S. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Umezawa, H.; Mokuno, Y. [National Institute of Advanced Industrial Science and Technology (AIST), 1-8-31 Midorigaoka, Ikeda, Osaka 563-8577 (Japan); Shikata, S. [Kwansei Gakuin Univ., 2-1, Gakuen, Mita, Hyogo 669-1337 (Japan); Makino, T.; Koka, M. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan); Hanaizumi, O. [Faculty of Science and Technology, Gunma University, Kiryu, Gunma 376-8515 (Japan); Kamiya, T.; Ohshima, T. [Japan Atomic Energy Agency, Takasaki, Gunma 370-1292 (Japan)

    2016-04-01

    To investigate electrically-active deep levels in high-resistivity single-crystalline diamond, particle-induced charge transient spectroscopy (QTS) techniques were performed using 5.5 MeV alpha particles and 9 MeV carbon focused microprobes. For unintentionally-doped (UID) chemical vapor deposition (CVD) diamond, deep levels with activation energies of 0.35 eV and 0.43 eV were detected which correspond to the activation energy of boron acceptors in diamond. The results suggested that alpha particle and heavy ion induced QTS techniques are the promising candidate for in-situ investigation of deep levels in high-resistivity semiconductors.

  17. Organic matter content and particle size modifications in mangrove sediments as responses to sea level rise.

    Science.gov (United States)

    Sanders, Christian J; Smoak, Joseph M; Waters, Mathew N; Sanders, Luciana M; Brandini, Nilva; Patchineelam, Sambasiva R

    2012-06-01

    Mangroves sediments contain large reservoirs of organic material (OM) as mangrove ecosystems produce large quantities and rapidly burial OM. Sediment accumulation rates of approximately 2.0 mm year(-1), based on (210)Pb(ex) dating, were estimated at the margin of two well-developed mangrove forest in southern Brazil. Regional data point to a relative sea level (RSL) rise of up to ∼4.0 mm year(-1). This RSL rise in turn, may directly influence the origin and quantity of organic matter (OM) deposited along mangrove sediments. Lithostratigraphic changes show that sand deposition is replacing the mud (<63 μm) fraction and OM content is decreasing in successively younger sediments. Sediment accumulation in coastal areas that are not keeping pace with sea level rise is potentially conducive to the observed shifts in particle size and OM content. Copyright © 2012 Elsevier Ltd. All rights reserved.

  18. Very low level α-particle detection by means of pulse shape discrimination

    International Nuclear Information System (INIS)

    Omori, M.

    1993-01-01

    A charge comparison pulse shape discriminator has been shown to be capable of low level alpha particle detection in a NE213 scintillator by discriminating against a high rate of gamma background. The clearly observed alpha peaks were due to 212 Po in 232 Th chain and 214 Po in 238 U chain with rates of 13.5/h and 15.6/h, and energies of 8.95 and 7.83 MeV respectively. For the 8.95 MeV alpha, the gamma background rate was reduced by a factor of 2.1 x 10 4 to a level of 22.5/h. The measurements were made in a low muon flux environment underground (1230 m deep). The detection limit for the alphas could be lowered to as low as 0.1-1 event per day deep underground by use of high purity PSD scintillators. (orig.)

  19. Incense, sparklers and cigarettes are significant contributors to indoor benzene and particle levels

    Directory of Open Access Journals (Sweden)

    Werner Tirler

    2015-03-01

    Full Text Available Introduction. The increased use of incense, magic candles and other flameless products often produces indoor pollutants that may represent a health risk for humans. Today, in fact, incense and air fresheners are used inside homes as well as in public places including stores, shopping malls and places of worship. As a source of indoor contamination, the impact of smoke, incense and sparklers on human health cannot be ignored. Aim. In the present work, we report the results of an emission study regarding particles (PM10 and particle number concentration, PNC and benzene, produced by various incense sticks and sparklers. Results and discussion.The results obtained for benzene, PM10 and PNC, showed a strong negative influence on air quality when these products were used indoors. Various incense sticks gave completely different benzene results: from a small increase of the benzene concentration in the air, just slightly above the background levels of ambient air, to very high concentrations, of more than 200 µg/m³ of benzene in the test room after the incense sticks had been tested.

  20. Incense, sparklers and cigarettes are significant contributors to indoor benzene and particle levels.

    Science.gov (United States)

    Tirler, Werner; Settimo, Gaetano

    2015-01-01

    The increased use of incense, magic candles and other flameless products often produces indoor pollutants that may represent a health risk for humans. Today, in fact, incense and air fresheners are used inside homes as well as in public places including stores, shopping malls and places of worship. As a source of indoor contamination, the impact of smoke, incense and sparklers on human health cannot be ignored. In the present work, we report the results of an emission study regarding particles (PM10 and particle number concentration, PNC) and benzene, produced by various incense sticks and sparklers. The results obtained for benzene, PM10 and PNC, showed a strong negative influence on air quality when these products were used indoors. Various incense sticks gave completely different benzene results: from a small increase of the benzene concentration in the air, just slightly above the background levels of ambient air, to very high concentrations, of more than 200 µg/m of benzene in the test room after the incense sticks had been tested.

  1. Particle swarm optimization based PID controller tuning for level control of two tank system

    Science.gov (United States)

    Vincent, Anju K.; Nersisson, Ruban

    2017-11-01

    Automatic control plays a vital role in industrial operation. In process industries, in order to have an improved and stable control system, we need a robust tuning method. In this paper Particle Swarm Optimization (PSO) based algorithm is proposed for the optimization of a PID controller for level control process. A two tank system is considered. Initially a PID controller is designed using an Internal Model Control (IMC). The results are compared with the PSO based controller setting. The performance of the controller is compared and analyzed by time domain specification. In order to validate the robustness of PID controller, disturbance is imposed. The system is simulated using MATLAB. The results show that the proposed method provides better controller performance.

  2. Particle-level simulations of flocculation in a fiber suspension flowing through a diffuser

    Directory of Open Access Journals (Sweden)

    Andrić Jelena S.

    2017-01-01

    Full Text Available We investigate flocculation in dilute suspensions of rigid, straight fibers in a decelerating flow field of a diffuser. We carry out numerical studies using a particle-level simulation technique that takes into account the fiber inertia and the non-creeping fiber-flow interactions. The fluid flow is governed by the Reynolds-averaged Navier-Stokes equations with the standard k-omega eddy-viscosity turbulence model. A one-way coupling between the fibers and the flow is considered with a stochastic model for the fiber dispersion due to turbulence. The fibers interact through short-range attractive forces that cause them to aggregate into flocs when fiber-fiber collisions occur. We show that ballistic deflection of fibers greatly increases the flocculation in the diffuser. The inlet fiber kinematics and the fiber inertia are the main parameters that affect fiber flocculation in the prediffuser region.

  3. Indoor and Outdoor Levels and Sources of Submicron Particles (PM1) at Homes in Edmonton, Canada.

    Science.gov (United States)

    Bari, Md Aynul; Kindzierski, Warren B; Wallace, Lance A; Wheeler, Amanda J; MacNeill, Morgan; Héroux, Marie-Ève

    2015-06-02

    Exposure to submicron particles (PM1) is of interest due to their possible chronic and acute health effects. Seven consecutive 24-h PM1 samples were collected during winter and summer 2010 in a total of 74 nonsmoking homes in Edmonton, Canada. Median winter concentrations of PM1 were 2.2 μg/m(3) (interquartile range, IQR = 0.8-6.1 μg/m(3)) and 3.3 μg/m(3) (IQR = 1.5-6.9 μg/m(3)) for indoors and outdoors, respectively. In the summer, indoor (median 4.4 μg/m(3), IQR = 2.4-8.6 μg/m(3)) and outdoor (median 4.3 μg/m(3), IQR = 2.6-7.4 μg/m(3)) levels were similar. Positive matrix factorization (PMF) was applied to identify and apportion indoor and outdoor sources of elements in PM1 mass. Nine sources contributing to both indoor and outdoor PM1 concentrations were identified including secondary sulfate, soil, biomass smoke and environmental tobacco smoke (ETS), traffic, settled and mixed dust, coal combustion, road salt/road dust, and urban mixture. Three additional indoor sources were identified i.e., carpet dust, copper-rich, and silver-rich. Secondary sulfate, soil, biomass smoke and ETS contributed more than 70% (indoors: 0.29 μg/m(3), outdoors: 0.39 μg/m(3)) of measured elemental mass in PM1. These findings can aid understanding of relationships between submicron particles and health outcomes for indoor/outdoor sources.

  4. Secondary particle background levels and effects on detectors at future hadron colliders

    International Nuclear Information System (INIS)

    Pal, T.

    1993-01-01

    The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC(LHC) √s=40TeV (√s=16TeV) and L=10 33 cm -2 s -1 (L=3x10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the open-quotes task force on radiation levels in the SSC interaction regions.close quotes The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes

  5. Secondary particle in background levels and effects on detectors at future hadron colliders

    International Nuclear Information System (INIS)

    Pal, T.

    1993-06-01

    The next generation of hadron colliders, the Superconducting Super Collider (SSC) and the Large Hadron Collider (LHC), will operate at high center-of-mass energies and luminosities. Namely, for the SSC (LHC) √s = 40 TeV (√s = 16 TeV) and L = 10 33 cm -2 s -1 (L = 3 x 10 34 cm -2 s -1 ). These conditions will result in the production of large backgrounds as well as radiation environments. Ascertaining the backgrounds, in terms of the production of secondary charged and neutral particles, and the radiation environments are important considerations for the detectors proposed for these colliders. An initial investigation of the radiation levels in the SSC detectors was undertaken by D. Groom and colleagues, in the context of the ''task force on radiation levels in the SSC interaction regions.'' The method consisted essentially of an analytic approach, using standard descriptions of average events in conjunction with simulations of secondary processes. Following Groom's work, extensive Monte Carlo simulations were performed to address the issues of backgrounds and radiation environments for the GEM and SD C3 experiments proposed at the SSC, and for the ATLAS and CMS experiments planned for the LHC. The purpose of the present article is to give a brief summary of some aspects of the methods, assumptions, and calculations performed to date (principally for the SSC detectors), and to stress the relevance of such calculations to the detectors proposed for the study of B-physics in particular

  6. Plastic scintillators in coincidence for the study of multi-particle production of sea level cosmic rays in dense medium

    Science.gov (United States)

    Chuang, L. S.; Chan, K. W.; Wada, M.

    1985-01-01

    Cosmic ray particles at sea level penetrate a thick layer of dense medium without appreciable interaction. These penetrating particles are identified with muons. The only appreciable interaction of muons are by knock on processes. A muon may have single, double or any number of knock on with atoms of the material so that one, two, three or more particles will come out from the medium in which the knock on processes occur. The probability of multiparticle production is expected to decrease with the increase of multiplicity. Measurements of the single, double, and triple particles generated in a dense medium (Fe and Al) by sea level cosmic rays at 22.42 N. Lat. and 114.20 E. Long. (Hong Kong) are presented using a detector composed of two plastic scintillators connected in coincidence.

  7. Reduction of atmospheric fine particle level by restricting the idling vehicles around a sensitive area.

    Science.gov (United States)

    Lee, Yen-Yi; Lin, Sheng-Lun; Yuan, Chung-Shin; Lin, Ming-Yeng; Chen, Kang-Shin

    2018-07-01

    Atmospheric particles are a major problem that could lead to harmful effects on human health, especially in densely populated urban areas. Chiayi is a typical city with very high population and traffic density, as well as being located at the downwind side of several pollution sources. Multiple contributors for PM 2.5 (particulate matter with an aerodynamic diameter ≥2.5 μm) and ultrafine particles cause complicated air quality problems. This study focused on the inhibition of local emission sources by restricting the idling vehicles around a school area and evaluating the changes in surrounding atmospheric PM conditions. Two stationary sites were monitored, including a background site on the upwind side of the school and a campus site inside the school, to monitor the exposure level, before and after the idling prohibition. In the base condition, the PM 2.5  mass concentrations were found to increase 15% from the background, whereas the nitrate (NO 3 - ) content had a significant increase at the campus site. The anthropogenic metal contents in PM 2.5 were higher at the campus site than the background site. Mobile emissions were found to be the most likely contributor to the school hot spot area by chemical mass balance modeling (CMB8.2). On the other hand, the PM 2.5 in the school campus fell to only 2% after idling vehicle control, when the mobile source contribution reduced from 42.8% to 36.7%. The mobile monitoring also showed significant reductions in atmospheric PM 2.5 , PM 0.1 , polycyclic aromatic hydrocarbons (PAHs), and black carbon (BC) levels by 16.5%, 33.3%, 48.0%, and 11.5%, respectively. Consequently, the restriction of local idling emission was proven to significantly reduce PM and harmful pollutants in the hot spots around the school environment. The emission of idling vehicles strongly affects the levels of particles and relative pollutants in near-ground air around a school area. The PM 2.5 mass concentration at a campus site increased from

  8. A Level-set based framework for viscous simulation of particle-laden supersonic flows

    Science.gov (United States)

    Das, Pratik; Sen, Oishik; Jacobs, Gustaaf; Udaykumar, H. S.

    2017-06-01

    Particle-laden supersonic flows are important in natural and industrial processes, such as, volcanic eruptions, explosions, pneumatic conveyance of particle in material processing etc. Numerical study of such high-speed particle laden flows at the mesoscale calls for a numerical framework which allows simulation of supersonic flow around multiple moving solid objects. Only a few efforts have been made toward development of numerical frameworks for viscous simulation of particle-fluid interaction in supersonic flow regime. The current work presents a Cartesian grid based sharp-interface method for viscous simulations of interaction between supersonic flow with moving rigid particles. The no-slip boundary condition is imposed at the solid-fluid interfaces using a modified ghost fluid method (GFM). The current method is validated against the similarity solution of compressible boundary layer over flat-plate and benchmark numerical solution for steady supersonic flow over cylinder. Further validation is carried out against benchmark numerical results for shock induced lift-off of a cylinder in a shock tube. 3D simulation of steady supersonic flow over sphere is performed to compare the numerically obtained drag co-efficient with experimental results. A particle-resolved viscous simulation of shock interaction with a cloud of particles is performed to demonstrate that the current method is suitable for large-scale particle resolved simulations of particle-laden supersonic flows.

  9. Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells

    DEFF Research Database (Denmark)

    Jantzen, Kim; Møller, Peter Horn; Karottki, Dorina Gabriela

    2016-01-01

    . Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate......Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked...... to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related...

  10. A frozen Gaussian approximation-based multi-level particle swarm optimization for seismic inversion

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jinglai, E-mail: jinglaili@sjtu.edu.cn [Institute of Natural Sciences, Department of Mathematics, and MOE Key Laboratory of Scientific and Engineering Computing, Shanghai Jiao Tong University, Shanghai 200240 (China); Lin, Guang, E-mail: lin491@purdue.edu [Department of Mathematics, School of Mechanical Engineering, Purdue University, West Lafayette, IN 47907 (United States); Computational Sciences and Mathematics Division, Pacific Northwest National Laboratory, Richland, WA 99352 (United States); Yang, Xu, E-mail: xuyang@math.ucsb.edu [Department of Mathematics, University of California, Santa Barbara, CA 93106 (United States)

    2015-09-01

    In this paper, we propose a frozen Gaussian approximation (FGA)-based multi-level particle swarm optimization (MLPSO) method for seismic inversion of high-frequency wave data. The method addresses two challenges in it: First, the optimization problem is highly non-convex, which makes hard for gradient-based methods to reach global minima. This is tackled by MLPSO which can escape from undesired local minima. Second, the character of high-frequency of seismic waves requires a large number of grid points in direct computational methods, and thus renders an extremely high computational demand on the simulation of each sample in MLPSO. We overcome this difficulty by three steps: First, we use FGA to compute high-frequency wave propagation based on asymptotic analysis on phase plane; Then we design a constrained full waveform inversion problem to prevent the optimization search getting into regions of velocity where FGA is not accurate; Last, we solve the constrained optimization problem by MLPSO that employs FGA solvers with different fidelity. The performance of the proposed method is demonstrated by a two-dimensional full-waveform inversion example of the smoothed Marmousi model.

  11. Dynamics of fibres in a turbulent flow field - A particle-level simulation technique

    International Nuclear Information System (INIS)

    Sasic, Srdjan; Almstedt, Alf-Erik

    2010-01-01

    A particle-level simulation technique has been developed for modelling the flow of fibres in a turbulent flow field. A single fibre is conceived here as a chain of segments, thus enabling the model fibre to have all the degrees of freedom (translation, rotation, bending and twisting) needed to realistically reproduce the dynamics of real fibres. Equations of motion are solved for each segment, accounting for the interaction forces with the fluid, the contact forces with other fibres and the forces that maintain integrity of the fibre. The motion of the fluid is resolved as a combination of 3D mean flow velocities obtained from a CFD code and fluctuating turbulent velocities derived from the Langevin equation. A case of homogeneous turbulence is treated in this paper. The results obtained show that fibre flocs in air-fibre flows can be created even when attractive forces are not present. In such a case, contacts between fibres, properties of an individual fibre (such as flexibility and equilibrium shapes) and properties of the flow of the carrying fluid are shown to govern the physics behind formation and breaking up of fibre flocs. Highly irregular fibre shapes and stiff fibres lead to strong flocculation. The modelling framework applied in this work aims at making possible a numerical model applicable for designing processes involving transport of fibres by air at industrial scale.

  12. Diffusion of dust particles from a point-source above ground level

    International Nuclear Information System (INIS)

    Hassan, M.H.A.; Eltayeb, I.A.

    1998-10-01

    A pollutant of small particles is emitted by a point source at a height h above ground level in an atmosphere in which a uni-directional wind speed, U, is prevailing. The pollutant is subjected to diffusion in all directions in the presence of advection and settling due to gravity. The equation governing the concentration of the pollutant is studied with the wind speed and the different components of diffusion tensor are proportional to the distance above ground level and the source has a uniform strength. Adopting a Cartesian system of coordinates in which the x-axis lies along the direction of the wind velocity, the z-axis is vertically upwards and the y-axis completes the right-hand triad, the solution for the concentration c(x,y,z) is obtained in closed form. The relative importance of the components of diffusion along the three axes is discussed. It is found that for any plane y=constant (=A), c(x,y,z) is concentrated along a curve of ''extensive pollution''. In the plane A=0, the concentration decreases along the line of extensive pollution as we move away from the source. However, for planes A≅0, the line of extensive pollution possesses a point of accumulation, which lies at a nonzero value of x. As we move away from the plane A=0, the point of accumulation moves laterally away from the plane x=0 and towards the plane z=0. The presence of the point of accumulation is entirely due to the presence of lateral diffusion. (author)

  13. Airborne particle-bound brominated flame retardants: Levels, size distribution and indoor-outdoor exchange.

    Science.gov (United States)

    Zhu, Yue-Shan; Yang, Wan-Dong; Li, Xiu-Wen; Ni, Hong-Gang; Zeng, Hui

    2018-02-01

    The quality of indoor environments has a significant impact on public health. Usually, an indoor environment is treated as a static box, in which physicochemical reactions of indoor air contaminants are negligible. This results in conservative estimates for primary indoor air pollutant concentrations, while also ignoring secondary pollutants. Thus, understanding the relationship between indoor and outdoor particles and particle-bound pollutants is of great significance. For this reason, we collected simultaneous indoor and outdoor measurements of the size distribution of airborne brominated flame retardant (BFR) congeners. The time-dependent concentrations of indoor particles and particle-bound BFRs were then estimated with the mass balance model, accounting for the outdoor concentration, indoor source strength, infiltration, penetration, deposition and indoor resuspension. Based on qualitative observation, the size distributions of ΣPBDE and ΣHBCD were characterized by bimodal peaks. According to our results, particle-bound BDE209 and γ-HBCD underwent degradation. Regardless of the surface adsorption capability of particles and the physicochemical properties of the target compounds, the concentration of BFRs in particles of different size fractions seemed to be governed by the particle distribution. Based on our estimations, for airborne particles and particle-bound BFRs, a window-open ventilated room only takes a quarter of the time to reach an equilibrium between the concentration of pollutants inside and outside compared to a closed room. Unfortunately, indoor pollutants and outdoor pollutants always exist simultaneously, which poses a window-open-or-closed dilemma to achieve proper ventilation. Copyright © 2017 Elsevier Ltd. All rights reserved.

  14. ML-Space: Hybrid Spatial Gillespie and Particle Simulation of Multi-Level Rule-Based Models in Cell Biology.

    Science.gov (United States)

    Bittig, Arne T; Uhrmacher, Adelinde M

    2017-01-01

    Spatio-temporal dynamics of cellular processes can be simulated at different levels of detail, from (deterministic) partial differential equations via the spatial Stochastic Simulation algorithm to tracking Brownian trajectories of individual particles. We present a spatial simulation approach for multi-level rule-based models, which includes dynamically hierarchically nested cellular compartments and entities. Our approach ML-Space combines discrete compartmental dynamics, stochastic spatial approaches in discrete space, and particles moving in continuous space. The rule-based specification language of ML-Space supports concise and compact descriptions of models and to adapt the spatial resolution of models easily.

  15. PAHs levels in gas and particle-bound phase in schools at different locations in Serbia

    Directory of Open Access Journals (Sweden)

    Živković Marija

    2015-01-01

    Full Text Available This study investigated seasonal variation of PAHs and their partition between gas and particulate-bounded phases in indoor and outdoor air in 4 schools in Serbia located at different locations. The sampling campaigns were conducted during one workweek at each school successively. Campaigns were conducted in schools during heating and non-heating seasons in December 2011 and June 2012. Seasonal variations of gas and particle-bounded PAHs concentrations were observed with higher levels during heating season. The highest total PAH values were associated with the gas phase in both sampling periods. The total PAHs concentration at indoor and at the outdoor sites, during heating season, ranged from 88.45 to 447.72 ng/m3 and 201.69 to 1017.15 ng/m3, respectively. During non-heating season, the total PAHs concentration ranged from 36.91 to 271.57 ng/m3 in indoor environment and 27.00 to 132.32 ng/m3 in outdoor environment. Most of the I/O ratios were less than 1, which indicated that the indoor PAHs were mostly from outdoor sources. The use of diagnostic ratio showed that traffic emission and coal combustion are the major sources of PAHs. Only the diagnostic ratios for the school, located near the industrial area, showed significant deviation compared to other schools. [Projekat Ministarstva nauke Republike Srbije, br. TR33036: Development of new meteorological mast for turbulence parameters characterization and br. III42008: Evaluation of Energy Performances and Indoor Environment Quality of Educational Buildings in Serbia with Impact to Health

  16. Exposure to ultrafine particles, intracellular production of reactive oxygen species in leukocytes and altered levels of endothelial progenitor cells

    International Nuclear Information System (INIS)

    Jantzen, Kim; Møller, Peter; Karottki, Dorina Gabriela; Olsen, Yulia; Bekö, Gabriel; Clausen, Geo; Hersoug, Lars-Georg; Loft, Steffen

    2016-01-01

    Exposure to particles in the fine and ultrafine size range has been linked to induction of low-grade systemic inflammation, oxidative stress and development of cardiovascular diseases. Declining levels of endothelial progenitor cells within systemic circulation have likewise been linked to progression of cardiovascular diseases. The objective was to determine if exposure to fine and ultrafine particles from indoor and outdoor sources, assessed by personal and residential indoor monitoring, is associated with altered levels of endothelial progenitor cells, and whether such effects are related to leukocyte-mediated oxidative stress. The study utilized a cross sectional design performed in 58 study participants from a larger cohort. Levels of circulating endothelial progenitor cells, defined as either late (CD34 + KDR + cells) or early (CD34 + CD133 + KDR + cells) subsets were measured using polychromatic flow cytometry. We additionally measured production of reactive oxygen species in leukocyte subsets (lymphocytes, monocytes and granulocytes) by flow cytometry using intracellular 2′,7′-dichlorofluoroscein. The measurements encompassed both basal levels of reactive oxygen species production and capacity for reactive oxygen species production for each leukocyte subset. We found that the late endothelial progenitor subset was negatively associated with levels of ultrafine particles measured within the participant residences and with reactive oxygen species production capacity in lymphocytes. Additionally, the early endothelial progenitor cell levels were positively associated with a personalised measure of ultrafine particle exposure and negatively associated with both basal and capacity for reactive oxygen species production in lymphocytes and granulocytes, respectively. Our results indicate that exposure to fine and ultrafine particles derived from indoor sources may have adverse effects on human vascular health.

  17. Effects of supplementation level and particle size of alfalfa hay on growth characteristics and rumen development in dairy calves

    NARCIS (Netherlands)

    Mirzaei, M.; Khorvash, M.; Ghorbani, G.R.; Kazemi-Bonchenari, M.; Riasi, A.; Nabipour, A.; Borne, van den J.J.G.C.

    2015-01-01

    The aim of this study was to assess the effects of particle size (PS) of alfalfa hay on growth characteristics and rumen development in dairy calves at two levels of alfalfa supplementation. Fifty newborn dairy calves (42.7 ± 2.2 kg BW) were used in a 2 × 2 factorial arrangement with the factors

  18. Effects of silica and calcium levels in nanobioglass ceramic particles on osteoblast proliferation

    International Nuclear Information System (INIS)

    Moorthi, A.; Parihar, P.R.; Saravanan, S.; Vairamani, M.; Selvamurugan, N.

    2014-01-01

    At nanoscale, bioglass ceramic (nBGC) particles containing calcium oxide (lime), silica and phosphorus pentoxide promote osteoblast proliferation. However, the role of varied amounts of calcium and silica present in nBGC particles on osteoblast proliferation is not yet completely known. Hence, the current work was aimed at synthesizing two different nBGC particles with varied amounts of calcium oxide and silica, nBGC-1: SiO 2 :CaO:P 2 O 5 ; mol% ∼ 70:25:5 and nBGC-2: SiO 2 :CaO:P 2 O 5 ; mol% ∼ 64:31:5, and investigating their role on osteoblast proliferation. The synthesized nBGC particles were characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) studies. They exhibited their size at nanoscale and were non-toxic to human osteoblastic cells (MG-63). The nBGC-2 particles were found to have more effect on stimulation of osteoblast proliferation and promoted entering of more cells into G2/M cell cycle phase compared to nBGC-1 particles. There was a differential expression of cyclin proteins in MG-63 cells by nBGC-1 and nBGC-2 treatments, and the expression of cyclin B1 and E proteins was found to be more by nBGC-2 treatment. Thus, these results provide us a new insight in understanding the design of various nBGC particles by altering their ionic constituents with desirable biological properties thereby supporting bone augmentation. - Highlights: • nBGC particles with varied amounts of calcium and silica were synthesized. • They were non-toxic to human osteoblastic cells. • nBGC-2 particles had more effect on stimulation of osteoblast proliferation. • nBGC-2 particles promoted entering of osteoblasts into G2/M cell cycle phase. • Expression of cyclin B1 and E proteins was found to be more by nBGC-2 treatment

  19. Effects of silica and calcium levels in nanobioglass ceramic particles on osteoblast proliferation

    Energy Technology Data Exchange (ETDEWEB)

    Moorthi, A.; Parihar, P.R.; Saravanan, S.; Vairamani, M.; Selvamurugan, N., E-mail: selvamurugan.n@ktr.srmuniv.ac.in

    2014-10-01

    At nanoscale, bioglass ceramic (nBGC) particles containing calcium oxide (lime), silica and phosphorus pentoxide promote osteoblast proliferation. However, the role of varied amounts of calcium and silica present in nBGC particles on osteoblast proliferation is not yet completely known. Hence, the current work was aimed at synthesizing two different nBGC particles with varied amounts of calcium oxide and silica, nBGC-1: SiO{sub 2}:CaO:P{sub 2}O{sub 5}; mol% ∼ 70:25:5 and nBGC-2: SiO{sub 2}:CaO:P{sub 2}O{sub 5}; mol% ∼ 64:31:5, and investigating their role on osteoblast proliferation. The synthesized nBGC particles were characterized by transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDS), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) studies. They exhibited their size at nanoscale and were non-toxic to human osteoblastic cells (MG-63). The nBGC-2 particles were found to have more effect on stimulation of osteoblast proliferation and promoted entering of more cells into G2/M cell cycle phase compared to nBGC-1 particles. There was a differential expression of cyclin proteins in MG-63 cells by nBGC-1 and nBGC-2 treatments, and the expression of cyclin B1 and E proteins was found to be more by nBGC-2 treatment. Thus, these results provide us a new insight in understanding the design of various nBGC particles by altering their ionic constituents with desirable biological properties thereby supporting bone augmentation. - Highlights: • nBGC particles with varied amounts of calcium and silica were synthesized. • They were non-toxic to human osteoblastic cells. • nBGC-2 particles had more effect on stimulation of osteoblast proliferation. • nBGC-2 particles promoted entering of osteoblasts into G2/M cell cycle phase. • Expression of cyclin B1 and E proteins was found to be more by nBGC-2 treatment.

  20. Particle-particle and hole-hole RPA correlations at finite temperature and the temperature dependence of the level density parameter

    International Nuclear Information System (INIS)

    Vinh Mau, N.

    1987-11-01

    The pp-hh RPA equations obtained by summing the infinite series of ladder, upwards and backwards going diagrams in the temperature two particle Green's functions are derived at finite temperature. The contribution to the thermodynamic grand potential due to pp-hh RPA correlations is calculated simultaneously to that of ph RPA correlations. A schematic model is constructed which shows that, as for ph RPA states, the energies of pp and hh RPA states have no temperature dependence at not too high temperature. Within the same model, the temperature dependence of the level density parameter is discussed

  1. Particle-particle and hole-hole RPA correlations at finite temperature and the temperature dependence of the level density parameter

    International Nuclear Information System (INIS)

    Vinh Mau, N.

    1989-01-01

    The pp-hh RPA equations obtained by summing the infinite series of ladder, upwards- and backwards-going diagrams in the temperature two-particle Green functions are derived at finite temperature. The contribution to the thermodynamic grand potential due to pp-hh RPA correlations is calculated simultaneously to that of ph RPA correlations. A schematic model is constructed which shows that, as for ph RPA states, the energies of pp and hh RPA states have no temperature dependence at not too high temperature. Within the same model, the temperature dependence of the level density parameter is discussed. (orig.)

  2. Development of a fluidized bed agglomeration modeling methodology to include particle-level heterogeneities in ash chemistry and granular physics

    Science.gov (United States)

    Khadilkar, Aditi B.

    The utility of fluidized bed reactors for combustion and gasification can be enhanced if operational issues such as agglomeration are mitigated. The monetary and efficiency losses could be avoided through a mechanistic understanding of the agglomeration process and prediction of operational conditions that promote agglomeration. Pilot-scale experimentation prior to operation for each specific condition can be cumbersome and expensive. So the development of a mathematical model would aid predictions. With this motivation, the study comprised of the following model development stages- 1) development of an agglomeration modeling methodology based on binary particle collisions, 2) study of heterogeneities in ash chemical composition and gaseous atmosphere, 3) computation of a distribution of particle collision frequencies based on granular physics for a poly-disperse particle size distribution, 4) combining the ash chemistry and granular physics inputs to obtain agglomerate growth probabilities and 5) validation of the modeling methodology. The modeling methodology comprised of testing every binary particle collision in the system for sticking, based on the extent of dissipation of the particles' kinetic energy through viscous dissipation by slag-liquid (molten ash) covering the particles. In the modeling methodology developed in this study, thermodynamic equilibrium calculations are used to estimate the amount of slag-liquid in the system, and the changes in particle collision frequencies are accounted for by continuously tracking the number density of the various particle sizes. In this study, the heterogeneities in chemical composition of fuel ash were studied by separating the bulk fuel into particle classes that are rich in specific minerals. FactSage simulations were performed on two bituminous coals and an anthracite to understand the effect of particle-level heterogeneities on agglomeration. The mineral matter behavior of these constituent classes was studied

  3. Probing correlated quantum many-body systems at the single-particle level

    International Nuclear Information System (INIS)

    Endres, Manuel

    2013-01-01

    The detection of correlation and response functions plays a crucial role in the experimental characterization of quantum many-body systems. In this thesis, we present novel techniques for the measurement of such functions at the single-particle level. Specifically, we show the single-atom- and single-site-resolved detection of an ultracold quantum gas in an optical lattice. The quantum gas is described by the Bose-Hubbard model, which features a zero temperature phase transition from a superfluid to a Mott-insulating state, a paradigm example of a quantum phase transition. We used the aforementioned detection techniques to study correlation and response properties across the superfluid-Mott-insulator transition. The single-atom sensitivity of our method is achieved by fluorescence detection of individual atoms with a high signal-to-noise ratio. A high-resolution objective collects the fluorescence light and yields in situ 'snapshots' of the quantum gas that allow for a single-site-resolved reconstruction of the atomic distribution. This allowed us to measure two-site and non-local correlation-functions across the superfluid-Mott-insulator transition. Non-local correlation functions are based on the information of an extended region of the system and play an important role for the characterization of low-dimensional quantum phases. While non-local correlation functions were so far only theoretical tools, our results show that they are actually experimentally accessible. Furthermore, we used a new thermometry scheme, based on the counting of individual thermal excitations, to measure the response of the system to lattice modulation. Using this method, we studied the excitation spectrum of the system across the two-dimensional superfluid-Mott-insulator transition. In particular, we detected a 'Higgs' amplitude mode in the strongly-interacting superfluid close to the transition point where the system is described by an effectively Lorentz-invariant low-energy theory

  4. Probing correlated quantum many-body systems at the single-particle level

    Energy Technology Data Exchange (ETDEWEB)

    Endres, Manuel

    2013-02-27

    The detection of correlation and response functions plays a crucial role in the experimental characterization of quantum many-body systems. In this thesis, we present novel techniques for the measurement of such functions at the single-particle level. Specifically, we show the single-atom- and single-site-resolved detection of an ultracold quantum gas in an optical lattice. The quantum gas is described by the Bose-Hubbard model, which features a zero temperature phase transition from a superfluid to a Mott-insulating state, a paradigm example of a quantum phase transition. We used the aforementioned detection techniques to study correlation and response properties across the superfluid-Mott-insulator transition. The single-atom sensitivity of our method is achieved by fluorescence detection of individual atoms with a high signal-to-noise ratio. A high-resolution objective collects the fluorescence light and yields in situ 'snapshots' of the quantum gas that allow for a single-site-resolved reconstruction of the atomic distribution. This allowed us to measure two-site and non-local correlation-functions across the superfluid-Mott-insulator transition. Non-local correlation functions are based on the information of an extended region of the system and play an important role for the characterization of low-dimensional quantum phases. While non-local correlation functions were so far only theoretical tools, our results show that they are actually experimentally accessible. Furthermore, we used a new thermometry scheme, based on the counting of individual thermal excitations, to measure the response of the system to lattice modulation. Using this method, we studied the excitation spectrum of the system across the two-dimensional superfluid-Mott-insulator transition. In particular, we detected a 'Higgs' amplitude mode in the strongly-interacting superfluid close to the transition point where the system is described by an effectively Lorentz

  5. Intragenotypic JFH1 based recombinant hepatitis C virus produces high levels of infectious particles but causes increased cell death

    DEFF Research Database (Denmark)

    Mateu, Guaniri; Donis, Ruben O; Wakita, Takaji

    2008-01-01

    The full-length hepatitis C virus (HCV) JFH1 genome (genotype 2a) produces moderate titers of infectious particles in cell culture but the optimal determinants required for virion production are unclear. It has been shown that intragenotypic recombinants encoding core to NS2 from J6CF...... in the context of JFH1 are more robust in the release of viral particles. To understand the contributions of structural and nonstructural genes to HCV replication potential and infectivity, we have characterized intragenotypic recombinant genotype 2a viruses with different portions of the J6 isolate engineered...... into the JFH1 infectious clone. All genomes produced high levels of intracellular HCV RNA and NS3 protein in Huh-7.5 transfected cells. However, JFH1 genomes containing J6 sequences from C to E2 (CE2) or C to p7 (Cp7) secreted up to 100-fold more infectious HCV particles than the parental JFH1 clone...

  6. Validation of new empirical model for self-leveling behavior of cylindrical particle beds based on experimental database

    International Nuclear Information System (INIS)

    Morita, Koji; Matsumoto, Tatsuya; Taketa, Shohei; Nishi, Shinpei; Cheng, Songbai; Suzuki, Tohru; Tobita, Yoshiharu

    2014-01-01

    During a material relocation phase of core disruptive accidents (CDAs) in sodium cooled fast reactors (SFRs), debris beds can be formed in the lower plenum region due to rapid quenching and fragmentation of molten core materials. Heat removal from debris beds is crucial to achieve so called in-vessel retention (IVR) of degraded core materials. Coolant boiling in the beds may lead to leveling of their mound shape, and then changes coolability of the beds with decay heat as well as neutronic characteristics. To clarify the mechanisms underlying this self-leveling behavior, several series of experiments using simulant materials has been performed in collaboration between Japan Atomic Energy Agency (JAEA) and Kyushu University in Japan. In the present study, experiments in a cylindrical system were employed to develop experimental data on self-leveling process of particle beds. In the experiments, to simulate the coolant boiling due to the decay heat in fuel, nitrogen gas was percolated uniformly through the bottom of the particle bed with a conical shape mound using a gas injection method. Time variations in bed height during the self-leveling process were measured for key experimental parameters on particle size, density and sphericity, and gas flow rate. Using a dimensional analysis approach, a new model was proposed to correlate the experimental data on transient bed height with an empirical equation using a characteristic time of self-leveling development and a terminal equilibrium height of the bed. It was demonstrated that the proposed model predicts self-leveling development of particle beds with reasonable accuracy in the present ranges of experimental conditions. (author)

  7. Fixed-target particle fluxes and radiation levels at SSC energies

    International Nuclear Information System (INIS)

    Dukes, E.C.

    1993-01-01

    The author calculates the charged particle fluxes and radiation doses from minimum ionizing particles (MIP), electromagnetic showers, and hadronic showers, in a fixed-target experiment at the SSC. This work follows the work of Groom, essentially boosting his results into the laboratory frame. The radiation in dense matter, such as a calorimeter, is produced by several sources: electromagnetic showers, hadronic showers, and minimum ionizing particles. The author does not consider other sources of radiation such as beam halo, a dependent effects, and low energy neutrons from secondary sources. Nor does he consider the effects of magnetic fields. Low energy neutrons have been shown to be an important source of radiation for collider experiments at the SSC. In fixed-target experiments, where the spectrometer is more open and where most detector elements are far away from secondary particle dumps, these sources are not as important. They are also very much detector and experimental hall dependent. Hence the results presented here are only a lower limit of the estimated radiation dose

  8. On mass in 4π solid angle around song CsI scintillator aboard coronas-I satellite

    International Nuclear Information System (INIS)

    Bucik, R.; Kudela, K.

    2003-01-01

    The complex geometric setup around the SONG CsI scintillator aboard the CORONAS-1 satellite has been modelled, to evaluate the mass thickness passed through by the cosmic ray particle striking the detector. The analytic functional form giving the amount of matter traversed in absorbers for an arbitrary incident directions is present. The population mean and variance of the mass thickness are estimated by random sampling of the uniformly distributed particle trajectories in the several solid angles (Authors)

  9. Particle Generation by Laser Ablation in Support of Chemical Analysis of High Level Mixed Waste from Plutonium Production Operations

    International Nuclear Information System (INIS)

    Dickinson, J. Thomas; Alexander, Michael L.

    2001-01-01

    Investigate particles produced by laser irradiation and their analysis by Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA/ICP-MS), with a view towards optimizing particle production for analysis of high level waste materials and waste glass. LA/ICP-MS has considerable potential to increase the safety and speed of analysis required for the remediation of high level wastes from cold war plutonium production operations. In some sample types, notably the sodium nitrate-based wastes at Hanford and elsewhere, chemical analysis using typical laser conditions depends strongly on the details of sample history composition in a complex fashion, rendering the results of analysis uncertain. Conversely, waste glass materials appear to be better behaved and require different strategies to optimize analysis

  10. Concentration levels and source apportionment of ultrafine particles in road microenvironments

    Science.gov (United States)

    Argyropoulos, G.; Samara, C.; Voutsa, D.; Kouras, A.; Manoli, E.; Voliotis, A.; Tsakis, A.; Chasapidis, L.; Konstandopoulos, A.; Eleftheriadis, K.

    2016-03-01

    A mobile laboratory unit (MOBILAB) with on-board instrumentation (Scanning Mobility Particle Sizer, SMPS; Ambient NOx analyzer) was used to measure size-resolved particle number concentrations (PNCs) of quasi-ultrafine particles (UFPs, 9-372 nm), along with NOx, in road microenvironments. On-road measurements were carried out in and around a large Greek urban agglomeration, the Thessaloniki Metropolitan Area (TMA). Two 2-week measurement campaigns were conducted during the warm period of 2011 and the cold period of 2012. During each sampling campaign, MOBILAB was driven through a 5-day inner-city route and a second 5-day external route covering in total a wide range of districts (urban, urban background, industrial and residential), and road types (major and minor urban roads, freeways, arterial and interurban roads). All routes were conducted during working days, in morning and in afternoon hours under real-world traffic conditions. Spatial classification of MOBILAB measurements involved the assignment of measurement points to location bins defined by the aspect ratio of adjacent urban street canyons (USCs). Source apportionment was further carried out, by applying Positive Matrix Factorization (PMF) to particle size distribution data. Apportioned PMF factors were interpreted, by employing a two-step methodology, which involved (a) statistical association of PMF factor contributions with 12 h air-mass back-trajectories ending at the TMA during MOBILAB measurements, and (b) Multiple Linear Regression (MLR) using PMF factor contributions as the dependent variables, while relative humidity, solar radiation flux, and vehicle speed were used as the independent variables. The applied data analysis showed that low-speed cruise and high-load engine operation modes are the two dominant sources of UFPs in most of the road microenvironments in the TMA, with significant contributions from background photochemical processes during the warm period, explaining the reversed

  11. Optimal control of quantum gates and suppression of decoherence in a system of interacting two-level particles

    International Nuclear Information System (INIS)

    Grace, Matthew; Brif, Constantin; Rabitz, Herschel; Walmsley, Ian A; Kosut, Robert L; Lidar, Daniel A

    2007-01-01

    Methods of optimal control are applied to a model system of interacting two-level particles (e.g., spin-half atomic nuclei or electrons or two-level atoms) to produce high-fidelity quantum gates while simultaneously negating the detrimental effect of decoherence. One set of particles functions as the quantum information processor, whose evolution is controlled by a time-dependent external field. The other particles are not directly controlled and serve as an effective environment, coupling to which is the source of decoherence. The control objective is to generate target one- and two-qubit unitary gates in the presence of strong environmentally-induced decoherence and under physically motivated restrictions on the control field. The quantum-gate fidelity, expressed in terms of a novel state-independent distance measure, is maximized with respect to the control field using combined genetic and gradient algorithms. The resulting high-fidelity gates demonstrate the feasibility of precisely guiding the quantum evolution via optimal control, even when the system complexity is exacerbated by environmental coupling. It is found that the gate duration has an important effect on the control mechanism and resulting fidelity. An analysis of the sensitivity of the gate performance to random variations in the system parameters reveals a significant degree of robustness attained by the optimal control solutions

  12. Types of Lightning Discharges that Abruptly Terminate Enhanced Fluxes of Energetic Radiation and Particles Observed at Ground Level

    International Nuclear Information System (INIS)

    Chilingarian, A.; Khanikyants, Y.; Pokhsraryan, D.; Soghomonyan, S.; Mareev, E.; Rakov, V.

    2017-01-01

    We present ground-based measurements of thunderstorm-related enhancements of fluxes of energetic radiation and particles that are abruptly terminated by lightning discharges. All measurements were performed at an altitude of 3200 m above sea level on Mt. Aragats (Armenia). Lightning signatures were recorded using a network of five electric field mills, three of which were placed at the Aragats station, one at the Nor Amberd station (12.8 km from Aragats), and one at the Yerevan station (39 km from Aragats), and a wideband electric field measuring system with a useful frequency bandwidth of 50 Hz to 12 MHZ. It appears that the flux-enhancement termination is associated with close (within 10 km or so of the particle detector) -CGs and normal polarity ICs; that is, with lightning types which reduce the upward-directed electric field below the cloud and, hence, suppress the acceleration of electrons toward the ground. (author)

  13. Energy levels of a scalar particle in a static gravitational field close to the black hole limit

    Science.gov (United States)

    Gossel, G. H.; Berengut, J. C.; Flambaum, V. V.

    2011-10-01

    The bound-state energy levels of a scalar particle in the gravitational field of finite-sized objects with interiors described by the Florides and Schwarzschild metrics are found. For these metrics, bound states with zero energy (where the binding energy is equal to the rest mass of the scalar particle) only exist when a singularity occurs in the metric. Therefore, in contrast to the Coulomb case, no pairs are produced in the non-singular static metric. For the Florides metric the singularity occurs in the black hole limit, while for the Schwarzschild interior metric it corresponds to infinite pressure at the center. Moreover, the energy spectrum is shown to become quasi-continuous as the metric becomes singular.

  14. Applications to particle and atomic physics of a ''theorem'' on the order of energy levels

    International Nuclear Information System (INIS)

    Grosse, H.; Pflug, A.; Martin, A.

    1984-01-01

    The sign of the Laplacian of the potential, in the Schroedinger equation, indicates in which way Coulomb degeneracy is lifted. We propose three applications of this property. The first one concerns the order of levels in heavy quark systems, the second the effects of the finite size of nuclei in mesic atoms, and the third the filling of atomic shells and the order of levels in alkaline atoms [fr

  15. Phone camera detection of glucose blood level based on magnetic particles entrapped inside bubble wrap.

    Science.gov (United States)

    Martinkova, Pavla; Pohanka, Miroslav

    2016-12-18

    Glucose is an important diagnostic biochemical marker of diabetes but also for organophosphates, carbamates, acetaminophens or salicylates poisoning. Hence, innovation of accurate and fast detection assay is still one of priorities in biomedical research. Glucose sensor based on magnetic particles (MPs) with immobilized enzymes glucose oxidase (GOx) and horseradish peroxidase (HRP) was developed and the GOx catalyzed reaction was visualized by a smart-phone-integrated camera. Exponential decay concentration curve with correlation coefficient 0.997 and with limit of detection 0.4 mmol/l was achieved. Interfering and matrix substances were measured due to possibility of assay influencing and no effect of the tested substances was observed. Spiked plasma samples were also measured and no influence of plasma matrix on the assay was proved. The presented assay showed complying results with reference method (standard spectrophotometry based on enzymes glucose oxidase and peroxidase inside plastic cuvettes) with linear dependence and correlation coefficient 0.999 in concentration range between 0 and 4 mmol/l. On the grounds of measured results, method was considered as highly specific, accurate and fast assay for detection of glucose.

  16. Solutions to HYDROCOIN [Hydrologic Code Intercomparison] Level 1 problems using STOKES and PARTICLE (Cases 1,2,4,7)

    International Nuclear Information System (INIS)

    Gureghian, A.B.; Andrews, A.; Steidl, S.B.; Brandstetter, A.

    1987-10-01

    HYDROCOIN (Hydrologic Code Intercomparison) Level 1 benchmark problems are solved using the finite element ground-water flow code STOKES and the pathline generating code PARTICLE developed for the Office of Crystalline Repository Development (OCRD). The objective of the Level 1 benchmark problems is to verify the numerical accuracy of ground-water flow codes by intercomparison of their results with analytical solutions and other numerical computer codes. Seven test cases were proposed for Level 1 to the Swedish Nuclear Power Inspectorate, the managing participant of HYDROCOIN. Cases 1, 2, 4, and 7 were selected by OCRD because of their appropriateness to the nature of crystalline repository hydrologic performance. The background relevance, conceptual model, and assumptions of each case are presented. The governing equations, boundary conditions, input parameters, and the solution schemes applied to each case are discussed. The results are shown in graphic and tabular form with concluding remarks. The results demonstrate the two-dimensional verification of STOKES and PARTICLE. 5 refs., 61 figs., 30 tabs

  17. A Bi-Level Particle Swarm Optimization Algorithm for Solving Unit Commitment Problems with Wind-EVs Coordinated Dispatch

    Science.gov (United States)

    Song, Lei; Zhang, Bo

    2017-07-01

    Nowadays, the grid faces much more challenges caused by wind power and the accessing of electric vehicles (EVs). Based on the potentiality of coordinated dispatch, a model of wind-EVs coordinated dispatch was developed. Then, A bi-level particle swarm optimization algorithm for solving the model was proposed in this paper. The application of this algorithm to 10-unit test system carried out that coordinated dispatch can benefit the power system from the following aspects: (1) Reducing operating costs; (2) Improving the utilization of wind power; (3) Stabilizing the peak-valley difference.

  18. Simultaneous measurements of particle number size distributions at ground level and 260 m on a meteorological tower in urban Beijing, China

    Science.gov (United States)

    Du, Wei; Zhao, Jian; Wang, Yuying; Zhang, Yingjie; Wang, Qingqing; Xu, Weiqi; Chen, Chen; Han, Tingting; Zhang, Fang; Li, Zhanqing; Fu, Pingqing; Li, Jie; Wang, Zifa; Sun, Yele

    2017-06-01

    Despite extensive studies into the characterization of particle number size distributions at ground level, real-time measurements above the urban canopy in the megacity of Beijing have never been performed to date. Here we conducted the first simultaneous measurements of size-resolved particle number concentrations at ground level and 260 m in urban Beijing from 22 August to 30 September. Our results showed overall similar temporal variations in number size distributions between ground level and 260 m, yet periods with significant differences were also observed. Particularly, accumulation-mode particles were highly correlated (r2 = 0. 85) at the two heights, while Aitken-mode particles presented more differences. Detailed analysis suggests that the vertical differences in number concentrations strongly depended on particle size, and particles with a mobility diameter between 100 and 200 nm generally showed higher concentrations at higher altitudes. Particle growth rates and condensation sinks were also calculated, which were 3.2 and 3.6 nm h-1, and 2.8 × 10-2 and 2.9 × 10-2 s-1, at ground level and 260 m, respectively. By linking particle growth with aerosol composition, we found that organics appeared to play an important role in the early stage of the growth (09:00-12:00 LT) while sulfate was also important during the later period. Positive matrix factorization of size-resolved number concentrations identified three common sources at ground level and 260 m, including a factor associated with new particle formation and growth events (NPEs), and two secondary factors that represent photochemical processing and regional transport. Cooking emission was found to have a large contribution to small particles and showed much higher concentration at ground level than 260 m in the evening. These results imply that investigation of NPEs at ground level in megacities needs to consider the influences of local cooking emissions. The impacts of regional emission controls on

  19. Continuous weeklong measurements of indoor particle levels in a Minnesota Tribal Casino Resort.

    Science.gov (United States)

    Zhou, Zheng; Bohac, David; Boyle, Raymond G

    2016-08-24

    Secondhand smoke (SHS) exposure for workers and patrons in hospitality venues is a persistent and significant public health concern. We designed this study to provide a comprehensive assessment of SHS exposure inside an Indian Tribal Casino in Minnesota. Real-time fine particulate matter (PM2.5) concentrations were measured at multiple locations for up to 7 days. The field monitoring provided information on the day of week and time of day variation of SHS exposure, as well as comparisons between smoking and non-smoking areas. Indoor PM2.5 level was nearly 13 times the concurrent outdoor PM2.5 level. Gaming floor hourly PM2.5 level was highest on Saturday night, averaged at 62.9 μg/m(3). Highest PM2.5 concentration was observed in smoking-permitted employee break room, reaching 600 μg/m(3). PM2.5 readings in non-smoking sections exhibited same temporal pattern as the readings in smoking sections. The results show that indoor concentration of PM2.5 is substantially higher than the outdoor level, posing health risks to casino workers and patrons. SHS can migrate into adjacent non-smoking areas very quickly. The casino's ventilation system did not fully eliminate SHS. A completely smoke-free casino would be the only way to fully protect non-smoking patrons and employees from the dangers of tobacco smoke.

  20. Shell-Tunneling Spectroscopy of the Single-Particle Energy Levels of Insulating Quantum Dots

    NARCIS (Netherlands)

    Bakkers, E.P.A.M.; Hens, Z.; Zunger, A.; Franceschetti, A; Kouwenhoven, L.P.; Gurevich, L.; Vanmaekelbergh, D.

    2001-01-01

    The energy levels of CdSe quantum dots are studied by scanning tunneling spectroscopy. By varying the tip-dot distance, we switch from "shell-filling" spectroscopy (where electrons accumulate in the dot and experience mutual repulsion) to "shell-tunneling" spectroscopy (where electrons tunnel, one

  1. Continuous weeklong measurements of indoor particle levels in a Minnesota Tribal Casino Resort

    Directory of Open Access Journals (Sweden)

    Zheng Zhou

    2016-08-01

    Full Text Available Abstract Background Secondhand smoke (SHS exposure for workers and patrons in hospitality venues is a persistent and significant public health concern. We designed this study to provide a comprehensive assessment of SHS exposure inside an Indian Tribal Casino in Minnesota. Methods Real-time fine particulate matter (PM2.5 concentrations were measured at multiple locations for up to 7 days. The field monitoring provided information on the day of week and time of day variation of SHS exposure, as well as comparisons between smoking and non-smoking areas. Results Indoor PM2.5 level was nearly 13 times the concurrent outdoor PM2.5 level. Gaming floor hourly PM2.5 level was highest on Saturday night, averaged at 62.9 μg/m3. Highest PM2.5 concentration was observed in smoking-permitted employee break room, reaching 600 μg/m3. PM2.5 readings in non-smoking sections exhibited same temporal pattern as the readings in smoking sections. Conclusions The results show that indoor concentration of PM2.5 is substantially higher than the outdoor level, posing health risks to casino workers and patrons. SHS can migrate into adjacent non-smoking areas very quickly. The casino’s ventilation system did not fully eliminate SHS. A completely smoke-free casino would be the only way to fully protect non-smoking patrons and employees from the dangers of tobacco smoke.

  2. Particle swarm optimization based artificial neural network model for forecasting groundwater level in Udupi district

    Science.gov (United States)

    Balavalikar, Supreetha; Nayak, Prabhakar; Shenoy, Narayan; Nayak, Krishnamurthy

    2018-04-01

    The decline in groundwater is a global problem due to increase in population, industries, and environmental aspects such as increase in temperature, decrease in overall rainfall, loss of forests etc. In Udupi district, India, the water source fully depends on the River Swarna for drinking and agriculture purposes. Since the water storage in Bajae dam is declining day-by-day and the people of Udupi district are under immense pressure due to scarcity of drinking water, alternatively depend on ground water. As the groundwater is being heavily used for drinking and agricultural purposes, there is a decline in its water table. Therefore, the groundwater resources must be identified and preserved for human survival. This research proposes a data driven approach for forecasting the groundwater level. The monthly variations in groundwater level and rainfall data in three observation wells located in Brahmavar, Kundapur and Hebri were investigated and the scenarios were examined for 2000-2013. The focus of this research work is to develop an ANN based groundwater level forecasting model and compare with hybrid ANN-PSO forecasting model. The model parameters are tested using different combinations of the data. The results reveal that PSO-ANN based hybrid model gives a better prediction accuracy, than ANN alone.

  3. A Chaotic Particle Swarm Optimization-Based Heuristic for Market-Oriented Task-Level Scheduling in Cloud Workflow Systems.

    Science.gov (United States)

    Li, Xuejun; Xu, Jia; Yang, Yun

    2015-01-01

    Cloud workflow system is a kind of platform service based on cloud computing. It facilitates the automation of workflow applications. Between cloud workflow system and its counterparts, market-oriented business model is one of the most prominent factors. The optimization of task-level scheduling in cloud workflow system is a hot topic. As the scheduling is a NP problem, Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) have been proposed to optimize the cost. However, they have the characteristic of premature convergence in optimization process and therefore cannot effectively reduce the cost. To solve these problems, Chaotic Particle Swarm Optimization (CPSO) algorithm with chaotic sequence and adaptive inertia weight factor is applied to present the task-level scheduling. Chaotic sequence with high randomness improves the diversity of solutions, and its regularity assures a good global convergence. Adaptive inertia weight factor depends on the estimate value of cost. It makes the scheduling avoid premature convergence by properly balancing between global and local exploration. The experimental simulation shows that the cost obtained by our scheduling is always lower than the other two representative counterparts.

  4. A Chaotic Particle Swarm Optimization-Based Heuristic for Market-Oriented Task-Level Scheduling in Cloud Workflow Systems

    Directory of Open Access Journals (Sweden)

    Xuejun Li

    2015-01-01

    Full Text Available Cloud workflow system is a kind of platform service based on cloud computing. It facilitates the automation of workflow applications. Between cloud workflow system and its counterparts, market-oriented business model is one of the most prominent factors. The optimization of task-level scheduling in cloud workflow system is a hot topic. As the scheduling is a NP problem, Ant Colony Optimization (ACO and Particle Swarm Optimization (PSO have been proposed to optimize the cost. However, they have the characteristic of premature convergence in optimization process and therefore cannot effectively reduce the cost. To solve these problems, Chaotic Particle Swarm Optimization (CPSO algorithm with chaotic sequence and adaptive inertia weight factor is applied to present the task-level scheduling. Chaotic sequence with high randomness improves the diversity of solutions, and its regularity assures a good global convergence. Adaptive inertia weight factor depends on the estimate value of cost. It makes the scheduling avoid premature convergence by properly balancing between global and local exploration. The experimental simulation shows that the cost obtained by our scheduling is always lower than the other two representative counterparts.

  5. Ice particle production in mid-level stratiform mixed-phase clouds observed with collocated A-Train measurements

    Directory of Open Access Journals (Sweden)

    D. Zhang

    2018-03-01

    Full Text Available Collocated A-Train CloudSat radar and CALIPSO lidar measurements between 2006 and 2010 are analyzed to study primary ice particle production characteristics in mid-level stratiform mixed-phase clouds on a global scale. For similar clouds in terms of cloud top temperature and liquid water path, Northern Hemisphere latitude bands have layer-maximum radar reflectivity (ZL that is  ∼  1 to 8 dBZ larger than their counterparts in the Southern Hemisphere. The systematically larger ZL under similar cloud conditions suggests larger ice number concentrations in mid-level stratiform mixed-phase clouds over the Northern Hemisphere, which is possibly related to higher background aerosol loadings. Furthermore, we show that springtime northern mid- and high latitudes have ZL that is larger by up to 6 dBZ (a factor of 4 higher ice number concentration than other seasons, which might be related to more dust events that provide effective ice nucleating particles. Our study suggests that aerosol-dependent ice number concentration parameterizations are required in climate models to improve mixed-phase cloud simulations, especially over the Northern Hemisphere.

  6. Characterization and Correlation of Particle-Level Interactions to the Macroscopic Rheology of Powders, Granular Slurries, and Colloidal Suspensions

    Energy Technology Data Exchange (ETDEWEB)

    Poloski, Adam P.; Daniel, Richard C.; Rector, David R.; Bredt, Paul R.; Buck, Edgar C.; Berg, John C.; Saez, Avelino E.

    2006-09-29

    Hanford TRU tank sludges are complex mixtures of undissolved minerals and salt solids in an aqueous phase of high ionic strength. They show complex rheological behavior resulting from interactions at the macroscopic level, such as interparticle friction between grains in the coarse fraction, as well as from interactions at the nano-scale level, such as the agglomeration of colloidal particles. An understanding of how phenomena such as interparticle friction and aggregate stability under shear will allow better control of Hanford TRU tank sludges being processed for disposal. The project described in this report had two objectives. The first was to understand the physical properties and behavior of the Hanford transuranic (TRU) tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of sludge physical properties by correlating the macroscopic behavior with interactions occurring at the particle/colloidal scale. These objectives were accomplished by: 1) developing continuum models for coarse granular slurries and 2) studying the behavior of colloidal agglomerates under shear and under irradiation.

  7. Effect of copper oxide wire particles dosage and feed supplement level on Haemonchus contortus infection in lambs.

    Science.gov (United States)

    Burke, J M; Miller, J E; Olcott, D D; Olcott, B M; Terrill, T H

    2004-09-02

    The objective of the experiment was to determine the optimal dose of copper oxide wire particles (COWPs) to reduce infection of Haemonchus contortus in male lambs. Five to six-month-old hair breed lambs were housed on concrete and fed 450 (L; n = 25) or 675 g (H; n = 25) corn/soybean meal supplement and bermudagrass hay. In July, lambs were inoculated with 10,000 L(3) larvae (97% H. contortus; Day 0). Lambs were administered 0, 2, 4, or 6 g COWP on Day 28. Concentrations of copper in the liver were determined. There were no effects of supplement level on concentrations of copper in the liver and a linear relationship existed between COWP treatment and concentrations of copper in liver (P copper in the liver of the COWP treatment groups. PCV values were more favorable for lambs fed the higher level of supplement, especially when FEC were greater than 8000 epg.

  8. Levels of 31P from [alpha]-particle capture in 27Al

    NARCIS (Netherlands)

    Voigt, M.J.A. de; Regenboog, D.A.; Grootenhuis, J.; Leun, C. van der

    1971-01-01

    Resonance energies, strengths and decay schemes have been determined for seventeen 27Al(α, γ)31P resonances in the range Eα = 2.3–3.3 MeV. New levels of 31P are reported at Ex = 6503±3, 6792±3, 7117.7±1.0, 7441.4±1.0 and 8345.5±1.5 keV. The reaction Q-value is found as 9665.1 ±1.3 keV. Doppler-shift

  9. Alteration of sperm quality and hormone levels by polycyclic aromatic hydrocarbons on airborne particulate particles.

    Science.gov (United States)

    Jeng, Hueiwang Anna; Yu, Liang

    2008-06-01

    The objective of this study was to assess whether polycyclic aromatic hydrocarbons (PAHs) affect male reproductive functions in vivo. Male reproductive parameters included testis weight, sperm counts and motility, circulating follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone. The average body weight, testis weight, and epididymis weight in the exposed group were not significantly lower than that in the control group (p sperm in the PAH-exposed groups were significantly lower than those in the control group. The motility of sperm in the PAH-exposed groups was significantly less than those in the control group. Plasma LH concentrations increased at the end of the exposure period and continued to increase after post-cessation of exposure to PAHs. Testosterone decreased at the end of the exposure period and increased after post-cessation of exposure. However, the follicle-stimulation hormone level remained relatively stable during the study period. The present study showed that PAHs can compromise sperm functions and alter endocrine hormone levels.

  10. A guide to radiation and radioactivity levels near high energy particle accelerators

    International Nuclear Information System (INIS)

    Sullivan, A.H.

    1992-01-01

    An estimate of likely radiation and radioactivity levels is needed at the design stage of an accelerator for deciding the radiation safety features to be incorporated in the infrastructure of the machine and for predicting where radiation damage possibilities will have to be taken into account. Both these aspects can have a significant influence on the machine layout and cost. Failure to make a reasonable assessment at the right time may have far reaching consequences for future costs. The purpose of this guide is to bring together basic data and methods that have been found useful in assessing radiation situations around accelerators and to provide a practical means of arriving at the radiation and induced radioactivity levels that could occur under a wide variety of circumstances. An attempt is made to present the information in a direct and unambiguous way with sufficient confidence that the necessity for large safety factors is avoided. In many cases assumptions and simplifications have been made and reliance placed on extrapolating from experimental data into regions where the basic physics is too complicated to make meaningful absolute calculations. Wherever possible such extrapolations have been tied to real or otherwise acceptable data originating from independent sources. (Author)

  11. ARE THERE TWO DISTINCT SOLAR ENERGETIC PARTICLE RELEASES IN THE 2012 MAY 17 GROUND LEVEL ENHANCEMENT EVENT?

    International Nuclear Information System (INIS)

    Ding, Liu-Guan; Jiang, Yong; Li, Gang

    2016-01-01

    We examine ion release times in the solar vicinity for the 2012 May 17 Ground Level Enhancement event using the velocity dispersion analysis method. In situ energetic proton data from Solar and Heliospheric Observatory (SOHO)/Energetic and Relativistic Nuclei and Electron and Geostationary Operational Environmental Satellite are used. We find two distinct releases of Solar Energetic Particles (SEPs) near the Sun, separated by ∼40 minutes. From soft X-ray observations, we find that the first release coincides with the solar flare eruption: the release starts from the flare onset and ends near the peak of the soft X-ray; type-III radio bursts also occur when the release starts. A type II radio burst may also start at the begining of the release. However, the associated Coronal Mass Ejection (CME) only has a height of 0.08R s from extrapolation of SOHO/LASCO data. At the start of the second release, the CME propagates to more than 8.4R s in height, and there are signatures of an enhanced type II radio burst. The time-integrated spectra for the two releases differ. The spectrum for the second release shows the common double-power-law feature of gradual SEP events. The spectrum for the first release does not resemble power laws because there is considerable modulation at lower energies. Based on our analysis, we suggest that SEPs of the first release were dominated by particles accelerated at the flare, and those of the second release were dominated by particles accelerated at the associated CME-driven shock. Our study may be important to understand certain extreme SEP events

  12. The Resource utilization by ATLAS High Level Triggers. The contributed talk for the Technology and Instrumentation in Particle Physics 2011.

    CERN Document Server

    Ospanov, R; The ATLAS collaboration

    2011-01-01

    In 2010 the ATLAS experiment has successfully recorded data from LHC collisions with high efficiency and excellent data quality. ATLAS employs a three-level trigger system to select events of interest for physics analyses and detector commissioning. The trigger system consists of a custom-designed hardware trigger at level-1 (L1) and software algorithms executing on commodity servers at the two higher levels: second level trigger (L2) and event filter (EF). The corresponding trigger rates are 75~kHz, 3~kHz and 200~Hz. The L2 uses custom algorithms to examine a small fraction of data at full detector granularity in Regions of Interest selected by the L1. The EF employs offline algorithms and full detector data for more computationally intensive analysis. The trigger selection is defined by trigger menus which consist of more than 500 individual trigger signatures, such as electrons, muons, particle jets, etc. An execution of a trigger signature incurs computing and data storage costs. A composition of the depl...

  13. Single-particle resonance levels in {sup 14}O examined by N13+p elastic resonance scattering

    Energy Technology Data Exchange (ETDEWEB)

    Teranishi, T. [Dept. of Physics, Kyushu Univ., 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)]. E-mail: teranishi@nucl.phys.kyushu-u.ac.jp; Kubono, S. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Yamaguchi, H. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); He, J.J. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Saito, A. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Fujikawa, H. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Amadio, G. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Niikura, M.; Shimoura, S. [Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Wakabayashi, Y. [Dept. of Physics, Kyushu Univ., 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)]|[Center for Nuclear Study (CNS), Univ. of Tokyo, Wako Branch at RIKEN, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Nishimura, S.; Nishimura, M. [RIKEN Nishina Center for Accelerator-Based Science, 2-1 Hirosawa, Wako, Saitama 351-0198 (Japan); Moon, J.Y.; Lee, C.S. [Dept. of Physics, Chung-Ang Univ., Seoul 156-756 (Korea, Republic of); Odahara, A. [Nishinippon Inst. of Technology, Kanda, Fukuoka 800-0394 (Japan); Sohler, D. [Inst. of Nuclear Research (ATOMKI), H-4001 Debrecen, P.O. Box 51 (Hungary); Khiem, L.H. [Inst. of Physics and Electronics (IOP), Vietnamese Academy for Science and Technology (VAST), 10 Daotan, Congvi, Badinh, P.O. Box 429-BOHO, Hanoi 10000 (Viet Nam); Li, Z.H.; Lian, G.; Liu, W.P. [China Inst. of Atomic Energy, P.O. Box 275(46), Beijing 102413 (China)

    2007-06-28

    Single-particle properties of low-lying resonance levels in {sup 14}O have been studied efficiently by utilizing a technique of proton elastic resonance scattering with a {sup 13}N secondary beam and a thick proton target. The excitation functions for the N13+p elastic scattering were measured over a wide energy range of E{sub CM}=0.4-3.3 MeV and fitted with an R-matrix calculation. A clear assignment of J{sup {pi}}=2{sup -} has been made for the level at E{sub x}=6.767(11) MeV in {sup 14}O for the first time. The excitation functions show a signature of a new 0{sup -} level at E{sub x}=5.71(2) MeV with {gamma}=400(100) keV. The excitation energies and widths of the {sup 14}O levels are discussed in conjunction with the spectroscopic structure of A=14 nuclei with T=1.

  14. Passive dosimetry aboard the Mir Orbital Station: internal measurements

    International Nuclear Information System (INIS)

    Benton, E.R.; Benton, E.V.; Frank, A.L.

    2002-01-01

    Passive radiation dosimeters were exposed aboard the Mir Orbital Station over a substantial portion of the solar cycle in order to measure the change in dose and dose equivalent rates as a function of time. During solar minimum, simultaneous measurements of the radiation environment throughout the habitable volume of the Mir were made using passive dosimeters in order to investigate the effect of localized shielding on dose and dose equivalent. The passive dosimeters consisted of a combination of thermoluminescent detectors to measure absorbed dose and CR-39 PNTDs to measure the linear energy transfer (LET) spectrum from charged particles of LET ∞ H 2 O≥5 keV/μm. Results from the two detector types were then combined to yield mean total dose rate, mean dose equivalent rate, and average quality factor. Contrary to expectations, both dose and dose equivalent rates measured during May-October 1991 near solar maximum were higher than similar measurements carried out in 1996-1997 during solar minimum. The elevated dose and dose equivalent rates measured in 1991 were probably due to a combination of intense solar activity, including a large solar particle event on 9 June 1991, and the temporary trapped radiation belt created in the slot region by the solar particle event and ensuing magnetic storm of 24 March 1991. During solar minimum, mean dose and dose equivalent rates were found to vary by factors of 1.55 and 1.37, respectively, between different locations through the interior of Mir. More heavily shielded locations tended to yield lower total dose and dose equivalent rates, but higher average quality factor than did more lightly shielding locations. However, other factors such as changes in the immediate shielding environment surrounding a given detector location, changes in the orientation of the Mir relative to its velocity vector, and changes in the altitude of the station also contributed to the variation. Proton and neutron-induced target fragment

  15. [EIA-IgG antibody measles prevention level estimated from measles neutralizing, particle agglutination and hemagglutination-inhibition antibody titer].

    Science.gov (United States)

    Takayama, Naohide; Saika, Shizuko; Ichinohe, Sadato

    2009-09-01

    Measles hemagglutination inhibition (HI) antibody titer, widely used in clinical practice to simply and easily determine the measles immunity level has, in recent years, been increasingly replaced by measles IgG-antibody titer determined by enzyme-immunoassay (EIA). HI antibody titer appears to reflect this protective level, because HI measures the antibody against H protein required for the measles virus to adhere to host cells. EIA-IgG antibody titer does not correlate with the protective level, similar to particle agglutination (PA) titer, because EIA measures different antibodies, including those unrelated to measles protection. After determining HI, PA, neutralizing test (NT) results, and EIA-IgG antibody titer for individual specimens, we compared EIA-IgG antibody titer obtained using an EIA-Kit (Denka Seiken) to HI, PA, and NT titer with the following results: (1) Subjects with EIA-IgG titer of > or = 12.0 may be protected against measles: (2) Subjects with EIA-IgG titer of 4.0 to 8.0 appear to be protected insufficiently requiring a booster dose against measles: (3) Subjects with EIA-IgG titer of 8.0 to 12.0 may benefit from booster vaccination.

  16. Particle Engulfment and Pushing

    Science.gov (United States)

    2001-01-01

    As a liquefied metal solidifies, particles dispersed in the liquid are either pushed ahead of or engulfed by the moving solidification front. Similar effects can be seen when the ground freezes and pushes large particles out of the soil. The Particle Engulfment and Pushing (PEP) experiment, conducted aboard the fourth U.S. Microgravity Payload (USMP-4) mission in 1997, used a glass and plastic beads suspended in a transparent liquid. The liquid was then frozen, trapping or pushing the particles as the solidifying front moved. This simulated the formation of advanced alloys and composite materials. Such studies help scientists to understand how to improve the processes for making advanced materials on Earth. The principal investigator is Dr. Doru Stefanescu of the University of Alabama. This image is from a video downlink.

  17. Levels, chemical composition and sources of fine aerosol particles (PM1) in an area of the Mediterranean basin

    International Nuclear Information System (INIS)

    Caggiano, Rosa; Macchiato, Maria; Trippetta, Serena

    2010-01-01

    Daily samples of fine aerosol particles (i.e., PM1, aerosol particles with an aerodynamic diameter less than 1.0 μm) were collected in Tito Scalo - Southern Italy - from April 2006 to March 2007. Measurements were performed by means of a low-volume gravimetric sampler, and each PM1 sample was analyzed by means of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) or Atomic Absorption Spectrometry (GFAAS and FAAS) techniques in order to determine its content in fourteen trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Ti and Zn). During the period examined, PM1 daily concentrations ranged between 0.3 μg m -3 and 55 μg m -3 with a mean value of 8 μg m -3 , a standard deviation of 7 μg m -3 and a median value of 6 μg m -3 . As far as PM1 chemical composition is concerned, the mean values of the trace element concentrations decreased in the following order: Ca > Fe > Al > Na > K > Cr > Mg > Pb > Ni ∼ Ti ∼ Zn > Cd ∼ Cu > Mn. Principal Component Analysis (PCA) allowed the identification of three probable PM1 sources: industrial emissions, traffic and re-suspension of soil dust. Moreover, the results of a procedure applied to study the potential long-range transport contribution to PM1 chemical composition, showed that trace element concentrations do not seem to be affected by air mass origin and path. This was probably due to the strong impact of the local emission sources and the lack of the concentration measurements of some important elements and compounds that could better reveal the long-range transport influence on PM1 measurements at ground level.

  18. Levels, chemical composition and sources of fine aerosol particles (PM1) in an area of the Mediterranean basin.

    Science.gov (United States)

    Caggiano, Rosa; Macchiato, Maria; Trippetta, Serena

    2010-01-15

    Daily samples of fine aerosol particles (i.e., PM1, aerosol particles with an aerodynamic diameter less than 1.0mum) were collected in Tito Scalo - Southern Italy - from April 2006 to March 2007. Measurements were performed by means of a low-volume gravimetric sampler, and each PM1 sample was analyzed by means of Inductively Coupled Plasma Optical Emission Spectrometry (ICP-OES) or Atomic Absorption Spectrometry (GFAAS and FAAS) techniques in order to determine its content in fourteen trace elements (Al, Ca, Cd, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, Ti and Zn). During the period examined, PM1 daily concentrations ranged between 0.3microgm(-3) and 55microgm(-3) with a mean value of 8 microg m(-3), a standard deviation of 7microgm(-3) and a median value of 6microgm(-3). As far as PM1 chemical composition is concerned, the mean values of the trace element concentrations decreased in the following order: Ca>Fe>Al>Na>K>Cr>Mg>Pb>Ni approximately Ti approximately Zn>Cd approximately Cu>Mn. Principal Component Analysis (PCA) allowed the identification of three probable PM1 sources: industrial emissions, traffic and re-suspension of soil dust. Moreover, the results of a procedure applied to study the potential long-range transport contribution to PM1 chemical composition, showed that trace element concentrations do not seem to be affected by air mass origin and path. This was probably due to the strong impact of the local emission sources and the lack of the concentration measurements of some important elements and compounds that could better reveal the long-range transport influence on PM1 measurements at ground level. Copyright 2009 Elsevier B.V. All rights reserved.

  19. Ultrafine particle levels at an international port of entry between the US and Mexico: exposure implications for users, workers, and neighbors.

    Science.gov (United States)

    Olvera, Hector A; Lopez, Mario; Guerrero, Veronica; Garcia, Humberto; Li, Wen-Whai

    2013-01-01

    Exposure to diesel-emitted particles has been linked to increased cancer risk and cardiopulmonary diseases. Because of their size (risks than those associated with larger particles. Seasonal UFP levels at the International Bridge of the Americas, which connects the US and Mexico and has high HDDV traffic demands, were characterized. Hourly average UFP concentrations ranged between 1.7 × 10(3)/cc and 2.9 × 10(5)/cc with a mean of 3.5 × 10(4)/cc. Wind speeds <2 m s(-1) and temperatures <15 °C were associated with particle number concentrations above normal conditions. The presence of HDDV had the strongest impact on local UFP levels. Varying particle size distributions were associated with south- and northbound HDDV traffic. Peak exposure occurred on weekday afternoons. Although in winter, high exposure episodes were also observed in the morning. Particle number concentrations were estimated to reach background levels at 400 m away from traffic. The populations exposed to UFP above background levels include law enforcement officers, street vendors, private commuters, and commercial vehicle drivers as well as neighbors on both sides of the border, including a church and several schools.

  20. Viral fusion efficacy of specific H3N2 influenza virus reassortant combinations at single-particle level

    Science.gov (United States)

    Hsu, Hung-Lun; Millet, Jean K.; Costello, Deirdre A.; Whittaker, Gary R.; Daniel, Susan

    2016-01-01

    Virus pseudotyping is a useful and safe technique for studying entry of emerging strains of influenza virus. However, few studies have compared different reassortant combinations in pseudoparticle systems, or compared entry kinetics of native viruses and their pseudotyped analogs. Here, vesicular stomatitis virus (VSV)-based pseudovirions displaying distinct influenza virus envelope proteins were tested for fusion activity. We produced VSV pseudotypes containing the prototypical X-31 (H3) HA, either alone or with strain-matched or mismatched N2 NAs. We performed single-particle fusion assays using total internal reflection fluorescence microscopy to compare hemifusion kinetics among these pairings. Results illustrate that matching pseudoparticles behaved very similarly to native virus. Pseudoparticles harboring mismatched HA-NA pairings fuse at significantly slower rates than native virus, and NA-lacking pseudoparticles exhibiting the slowest fusion rates. Relative viral membrane HA density of matching pseudoparticles was higher than in mismatching or NA-lacking pseudoparticles. An equivalent trend of HA expression level on cell membranes of HA/NA co-transfected cells was observed and intracellular trafficking of HA was affected by NA co-expression. Overall, we show that specific influenza HA-NA combinations can profoundly affect the critical role played by HA during entry, which may factor into viral fitness and the emergence of new pandemic influenza viruses. PMID:27752100

  1. Magnetic particles

    Science.gov (United States)

    Chang, Manchium (Inventor); Colvin, Michael S. (Inventor)

    1989-01-01

    Magnetic polymer particles are formed by swelling porous, polymer particles and impregnating the particles with an aqueous solution of precursor magnetic metal salt such as an equimolar mixture of ferrous chloride and ferric chloride. On addition of a basic reagent such as dilute sodium hydroxide, the metal salts are converted to crystals of magnetite which are uniformly contained througout the pores of the polymer particle. The magnetite content can be increased and neutral buoyancy achieved by repetition of the impregnaton and neutralization steps to adjust the magnetite content to a desired level.

  2. Simulation of the time structure of Extensive Air Showers with CORSIKA initiated by various primary particles at Alborz-I observatory level

    Science.gov (United States)

    Bahmanabadi, Mahmud; Moghaddam, Saba Mortazavi

    2018-05-01

    A detailed simulation of showers with various zenith angles in atmosphere produced by different primary particles including gamma, proton, carbon, and iron at Alborz-I observatory level (35∘43‧N, 51∘20‧E, 1200 m a.s.l= 890 gcm-2), in the energy range 3 × 1013 eV-3 × 1015 eV, has been performed by means of the CORSIKA Monte Carlo code. The aim of this study is to examine the time structure of secondary particles in Extensive Air Showers (EAS) produced by the different primary particles. For each primary particle, the distribution of the mean values of the time delays of secondary particles relative to the first particle hitting the ground level in each EAS, = , and the distribution of their mean standard deviations, in terms of distance from the shower core are obtained. The mean thickness and profile of showers as a function of their energy, primary mass, and zenith angle is described.

  3. Skeletal muscle glycogen content and particle size of distinct subcellular localizations in the recovery period after a high-level soccer match

    DEFF Research Database (Denmark)

    Nielsen, Joachim; Krustrup, Peter; Nybo, Lars

    2012-01-01

    Whole muscle glycogen levels remain low for a prolonged period following a soccer match. The present study was conducted to investigate how this relates to glycogen content and particle size in distinct subcellular localizations. Seven high-level male soccer players had a vastus lateralis muscle...... biopsy collected immediately after and 24, 48, 72 and 120 h after a competitive soccer match. Transmission electron microscopy was used to estimate the subcellular distribution of glycogen and individual particle size. During the first day of recovery, glycogen content increased by ~60% in all...

  4. Particles geometry influence in the thermal stress level in an SiC reinforced aluminum matrix composite considering the material non-linear behavior

    International Nuclear Information System (INIS)

    Miranda, Carlos A. de J.; Libardi, Rosani M.P.; Boari, Zoroastro de M.

    2009-01-01

    An analytical methodology was developed to predict the thermal stress level that occurs in a metallic matrix composite reinforced with SiC particles, when the temperature decreases from 600 deg C to 20 deg C during the fabrication process. This analytical development is based on the Eshelby method, dislocation mechanisms, and the Maxwell-Boltzmann distribution model. The material was assumed to have a linear elastic behavior. The analytical results from this formulation were verified against numerical linear analyses that were performed over a set of random non-uniform distribution of particles that covers a wide range of volumetric ratios. To stick with the analytical hypothesis, particles with round geometry were used. Each stress distribution, represented by the isostress curves at ΔT=-580 deg C, was analyzed with an image analyzer. A statistical procedure was applied to obtain the most probable thermal stress level. Analytical and numerical results compared very well. Plastic deformation as well as particle geometry can alter significantly the stress field in the material. To account for these effects, in this work, several numerical analyses were performed considering the non-linear behavior for the aluminum matrix and distinct particle geometries. Two distinct sets of data with were used. To allow a direct comparison, the first set has the same models (particle form, size and distribution) as used previously. The second set analyze quadrilateral particles and present very tight range of volumetric ratio, closer to what is found in actual SiC composites. A simple and fast algorithm was developed to analyze the new results. The comparison of these results with the previous ones shows, as expected, the strong influence of the elastic-plastic behavior of the aluminum matrix on the composite thermal stress distribution due to its manufacturing process and shows, also, a small influence of the particles geometry and volumetric ratio. (author)

  5. Particle swarm optimization based support vector machine for damage level prediction of non-reshaped berm breakwater

    Digital Repository Service at National Institute of Oceanography (India)

    Harish, N.; Mandal, S.; Rao, S.; Patil, S.G.

    breakwater. Soft computing tools like Artificial Neural Network, Fuzzy Logic, Support Vector Machine (SVM), etc, are successfully used to solve complex problems. In the present study, SVM and hybrid of Particle Swarm Optimization (PSO) with SVM (PSO...

  6. Liouvillian propagator technique for perturbed wave functions, level shifts and broadenings of composite particles in a many-body medium

    International Nuclear Information System (INIS)

    Girardeau, M.D.; Oregon Univ., Eugene

    1981-01-01

    Many problems in several areas of physics and chemistry involve many-body systems of interacting composite particles, in regimes where their internal transitions and/or reactive collisions (breakup, recombination, rearrangement) are important. Standard many-body Green's function and quantum field theoretic techniques are not well adapted to such situations. I discuss generalized representations which allow application of standard techniques to more complicated systems of interacting composite particles and their constituents. (orig./HSI)

  7. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

    Provides step-by-step derivations. Contains numerous tables and diagrams. Supports learning and teaching with numerous worked examples, questions and problems with answers. Sketches also the historical development of the subject. This textbook teaches particle physics very didactically. It supports learning and teaching with numerous worked examples, questions and problems with answers. Numerous tables and diagrams lead to a better understanding of the explanations. The content of the book covers all important topics of particle physics: Elementary particles are classified from the point of view of the four fundamental interactions. The nomenclature used in particle physics is explained. The discoveries and properties of known elementary particles and resonances are given. The particles considered are positrons, muon, pions, anti-protons, strange particles, neutrino and hadrons. The conservation laws governing the interactions of elementary particles are given. The concepts of parity, spin, charge conjugation, time reversal and gauge invariance are explained. The quark theory is introduced to explain the hadron structure and strong interactions. The solar neutrino problem is considered. Weak interactions are classified into various types, and the selection rules are stated. Non-conservation of parity and the universality of the weak interactions are discussed. Neutral and charged currents, discovery of W and Z bosons and the early universe form important topics of the electroweak interactions. The principles of high energy accelerators including colliders are elaborately explained. Additionally, in the book detectors used in nuclear and particle physics are described. This book is on the upper undergraduate level.

  8. Camera aboard 'Friendship 7' photographs John Glenn during spaceflight

    Science.gov (United States)

    1962-01-01

    A camera aboard the 'Friendship 7' Mercury spacecraft photographs Astronaut John H. Glenn Jr. during the Mercury-Atlas 6 spaceflight (00302-3); Photographs Glenn as he uses a photometer to view the sun during sunsent on the MA-6 space flight (00304).

  9. Editorial: aboard the Red Dragon in 2017 | Thurman | Shakespeare ...

    African Journals Online (AJOL)

    Editorial: aboard the Red Dragon in 2017. Chris Thurman. Abstract. No Abstract. Full Text: EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/sisa.v29i1.1 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors ...

  10. Mixing fuel particles for space combustion research using acoustics

    Science.gov (United States)

    Burns, Robert J.; Johnson, Jerome A.; Klimek, Robert B.

    1988-01-01

    Part of the microgravity science to be conducted aboard the Shuttle (STS) involves combustion using solids, particles, and liquid droplets. The central experimental facts needed for characterization of premixed quiescent particle cloud flames cannot be adequately established by normal gravity studies alone. The experimental results to date of acoustically mixing a prototypical particulate, lycopodium, in a 5 cm diameter by 75 cm long flame tube aboard a Learjet aircraft flying a 20-sec low-gravity trajectory are described. Photographic and light detector instrumentation combine to measure and characterize particle cloud uniformity.

  11. Low Energy Particle Oscillations and Correlations with Hydromagnetic Waves in the Jovian Magnetosphere: Ulysses Measurements

    Science.gov (United States)

    Krupp, N.; Tsurutani, B. T.; Lanzerotti, L. J.; Maclennan, C. G.

    1996-01-01

    We report on measurements of energetic particle modulations observed by the HI-SCALE instrument aboard the Ulysses Spacecraft that were associated with the only hydromagnetic wave event measured inside the Jovian magnetosphere by the Ulysses magnetometer investigation.

  12. Transport and Deposition of Micro-and Nano-Particles in Human Tracheobronchial Tree by an Asymmetric Multi-Level Bifurcation Model

    Directory of Open Access Journals (Sweden)

    Lin Tian

    2012-06-01

    Full Text Available Transport and deposition of particles in the upper tracheobronchial tree were analyzed using a multi-level asymmetric lung bifurcation model. The first three generations of tracheobronchial tree were included in the study. The laryngeal jet at the trachea entrance was modeled as an effective turbulence disturbance, and the study was focused on how to accurately simulate the airflow and predict the motion of the inhaled particles. Downstream in the lower level of the bronchial region, a laminar flow model was used, as smoother flow condition was expected. Transport and deposition of nano- and micro-scale spherical particles in the range of 0.01 μm to 30 μm were evaluated. The particle local deposition pattern and deposition rate in the lung bifurcation was discussed. The proposed multi-level asymmetric lung bifurcation model was found to be flexible, easy to use and computationally highly efficient. It was also shown that the selection of the anisotropic Reynolds stress transport turbulence model (RSTM was appropriate, and the use of the enhanced two-layer model boundary treatment was needed for accurate simulation of the turbulent airflow conditions in the upper airways.

  13. Results on artemia cysts, lettuce and tobacco seeds in the Biobloc 4 experiment flown aboard the Soviet biosatellite Cosmos 1129

    International Nuclear Information System (INIS)

    Gaubin, Y.; Planel, H.; Gasset, G.; Pianezzi, B.

    1983-01-01

    The effects of space flight factors, in particular the heavy ion component of cosmic rays, on dormant stages of life forms were investigated as part of the Biobloc 4 experiment flown aboard the Cosmos 1129 biosatellite. Artemia cysts and seeds of tobacco and lettuce plants were placed in tubes and in monolayers sandwiched between layers of visual particle track detectors. Although Artemia cysts exposed in the dry state did not differ from ground controls, hydrated cysts exhibited a slight decrease in hatchability and reduced (C-14)O2 incorporation and protein and nucleic acid synthesis. For cysts held in the monolayers, hits by HZE particles were observed to stimulate emergence, hatching and survival. Higher proportions of chromosomal aberrations were found in lettuce seeds hit by HZE particles, while space flight produced a stimulatory effect on both germination rate and abnormality frequency in both hit and nonhit tobacco seeds. 9 references

  14. Reduced ultrafine particle levels in São Paulo's atmosphere during shifts from gasoline to ethanol use.

    Science.gov (United States)

    Salvo, Alberto; Brito, Joel; Artaxo, Paulo; Geiger, Franz M

    2017-07-18

    Despite ethanol's penetration into urban transportation, observational evidence quantifying the consequence for the atmospheric particulate burden during actual, not hypothetical, fuel-fleet shifts, has been lacking. Here we analyze aerosol, meteorological, traffic, and consumer behavior data and find, empirically, that ambient number concentrations of 7-100-nm diameter particles rise by one-third during the morning commute when higher ethanol prices induce 2 million drivers in the real-world megacity of São Paulo to substitute to gasoline use (95% confidence intervals: +4,154 to +13,272 cm -3 ). Similarly, concentrations fall when consumers return to ethanol. Changes in larger particle concentrations, including US-regulated PM2.5, are statistically indistinguishable from zero. The prospect of increased biofuel use and mounting evidence on ultrafines' health effects make our result acutely policy relevant, to be weighed against possible ozone increases. The finding motivates further studies in real-world environments. We innovate in using econometrics to quantify a key source of urban ultrafine particles.The biofuel ethanol has been introduced into urban transportation in many countries. Here, by measuring aerosols in São Paulo, the authors find that high ethanol prices coincided with an increase in harmful nanoparticles by a third, as drivers switched from ethanol to cheaper gasoline, showing a benefit of ethanol.

  15. CNAM: care and treatment aboard in oncology

    International Nuclear Information System (INIS)

    Cherif, Leila; Bayoudh, L.; Riahi, S.; Zarrad, M.

    2013-01-01

    The Tunisian National Health Insurance Fund (TNHIF) has 186 practitioners and advisers (physicians, dentists and pharmacists) in the service of medical supervision. These advisers are distributed on three levels (regional, district and national). In the present paper we have discussed the CNAM support in the different types of oncology (FSD (Fully Supported Disorders), Hospitalization, the scans, the radiation therapy, specific drugs and treatment abroad). We begin by presenting expenditures by year and age group for FSD and hospitalization in the private and the public sectors. We then give the conventional packages for scans, radiotherapy: either for CLAM or CRAM. Daily benefits for the sickness leave and the disability will be presented briefly. Then we will give the administrative process for the approval of the commission for specific medication. The medical advice is based on certain criteria that will be explained in the paper. In certain cases definitive medical advice needs to call for the recommendation of a national commission and oncology or different experts. The spending trend of the TNHIF from 2001 to 2012 will be discussed. TNHIF generally considered Herceptin, Nexavar Erbitaux as the main drugs for targeted therapies. We present for the treatment cost and expenditure trends for the first drug from 2008 to 2012 as well as the estimation for 2013, which increases from one year to year. For the treatment with the second and the third drug we give the evolution of expenditure between 2010 and 2012. Cancer is a serious disease that requires a costly multidisciplinary support for the patients. This support has changed the prognosis survival (see cases of healing). The financial coverage of this support can never be supported by the family (whatever the wealth level) without any TNHIF support. The real gain in survival and expenditure control are closely related to awareness and early detection of the disease. TNHIF usually intervenes in the financing of

  16. Microgravity Science Glovebox Aboard the International Space Station

    Science.gov (United States)

    2003-01-01

    In the Destiny laboratory aboard the International Space Station (ISS), European Space Agency (ESA) astronaut Pedro Duque of Spain is seen working at the Microgravity Science Glovebox (MSG). He is working with the PROMISS experiment, which will investigate the growth processes of proteins during weightless conditions. The PROMISS is one of the Cervantes program of tests (consisting of 20 commercial experiments). The MSG is managed by NASA's Marshall Space Flight Center (MSFC).

  17. Effect of particle- and specimen-level transport on product state in compacted-powder combustion synthesis and thermal debinding of polymers from molded powders

    Science.gov (United States)

    Oliveira, Amir Antonio Martins

    The existence of large gradients within particles and fast temporal variations in the temperature and species concentration prevents the use of asymptotic approximations for the closure of the volume-averaged, specimen-level formulations. In this case a solution of the particle-level transport problem is needed to complement the specimen-level volume-averaged equations. Here, the use of combined specimen-level and particle-level models for transport in reactive porous media is demonstrated with two examples. For the gasless compacted-powder combustion synthesis, a three-scale model is developed. The specimen-level model is based on the volume-averaged equations for species and temperature. Local thermal equilibrium is assumed and the macroscopic mass diffusion and convection fluxes are neglected. The particle-level model accounts for the interparticle diffusion (i.e., the liquid migration from liquid-rich to liquid-lean regions) and the intraparticle diffusion (i.e., the species mass diffusion within the product layer formed at the surface of the high melting temperature component). It is found that the interparticle diffusion controls the extent of conversion to the final product, the maximum temperature, and to a smaller degree the propagation velocity. The intraparticle diffusion controls the propagation velocity and to a smaller degree the maximum temperature. The initial stages of thermal degradation of EVA from molded specimens is modeled using volume-averaged equations for the species and empirical models for the kinetics of the thermal degradation, the vapor-liquid equilibrium, and the diffusion coefficient of acetic acid in the molten polymer. It is assumed that a bubble forms when the partial pressure of acetic acid exceeds the external ambient pressure. It is found that the removal of acetic acid is characterized by two regimes, a pre-charge dominated regime and a generation dominated regime. For the development of an optimum debinding schedule, the

  18. Assessment of homogeneity of candidate reference material at the nanogram level and investigation on representativeness of single particle analysis using electron probe X ray microanalysis

    International Nuclear Information System (INIS)

    Ro, Chul-Un; Hoornaerta, S.; Griekena, R. van

    2002-01-01

    Particulate samples of a candidate reference material are evaluated on their homogeneity from bottle to bottle using electron probe X ray microanalysis technique. The evaluation on the homogeneity is done by the utilization of the Kolmogorov-Smirnov statistics to the processing of the quantitative electron probe X ray microanalysis data. Due to a limitation, existing even in computer controlled electron probe X ray microanalysis, in terms of analysis time and expenses, the number of particles analyzed is much smaller compared to that in the sample. Therefore, it is investigated whether this technique provides representative analysis results for the characteristics of the sample, even though a very small portion of the sample is really analyzed. Furthermore, the required number of particles for the analysis, to insure a certain level of reproducibility, e.g. 5% relative standard deviation, is determined by the application of the Ingamells sampling theory. (author)

  19. Characterization and Correlation of Particle-Level Interactions to the Macroscopic Rheology of Powders, Granular Slurries, and Colloidal Suspensions

    Energy Technology Data Exchange (ETDEWEB)

    A.P. Poloski; R.C. Daniel; D.R. Rector; P.R. Bredt; E.C. Buck; Berg, J.C.; Saez, A.E.

    2006-09-29

    This project had two primary objectives. The first was to understand the physical properties and behavior of select Hanford tank sludges under conditions that might exist during retrieval, treatment, packaging, and transportation for disposal at the Waste Isolation Pilot Plant (WIPP). The second objective was to develop a fundamental understanding of these sludge suspensions by correlating the macroscopic properties with particle interactions occurring at the colloidal scale. The specific tank wastes considered herein are contained in thirteen Hanford tanks including three double-shell tanks (DSTs) (AW-103, AW-105, and SY-102) and ten single-shell tanks (SSTs) (B-201 through B-204, T-201 through T-204, T-110, and T-111). At the outset of the project, these tanks were designated as potentially containing transuranic (TRU) process wastes that would be treated and disposed of in a manner different from the majority of the tank wastes.

  20. High-Level Systemic Expression of Conserved Influenza Epitope in Plants on the Surface of Rod-Shaped Chimeric Particles

    Directory of Open Access Journals (Sweden)

    Natalia V. Petukhova

    2014-04-01

    Full Text Available Recombinant viruses based on the cDNA copy of the tobacco mosaic virus (TMV genome carrying different versions of the conserved M2e epitope from influenza virus A cloned into the coat protein (CP gene were obtained and partially characterized by our group previously; cysteines in the human consensus M2e sequence were changed to serine residues. This work intends to show some biological properties of these viruses following plant infections. Agroinfiltration experiments on Nicotiana benthamiana confirmed the efficient systemic expression of M2e peptides, and two point amino acid substitutions in recombinant CPs significantly influenced the symptoms and development of viral infections. Joint expression of RNA interference suppressor protein p19 from tomato bushy stunt virus (TBSV did not affect the accumulation of CP-M2e-ser recombinant protein in non-inoculated leaves. RT-PCR analysis of RNA isolated from either infected leaves or purified TMV-M2e particles proved the genetic stability of TMV‑based viral vectors. Immunoelectron microscopy of crude plant extracts demonstrated that foreign epitopes are located on the surface of chimeric virions. The rod‑shaped geometry of plant-produced M2e epitopes is different from the icosahedral or helical filamentous arrangement of M2e antigens on the carrier virus-like particles (VLP described earlier. Thereby, we created a simple and efficient system that employs agrobacteria and plant viral vectors in order to produce a candidate broad-spectrum flu vaccine.

  1. Particle Pollution

    Science.gov (United States)

    ... Your Health Particle Pollution Public Health Issues Particle Pollution Recommend on Facebook Tweet Share Compartir Particle pollution — ... see them in the air. Where does particle pollution come from? Particle pollution can come from two ...

  2. BEAR RFQ-beam experiment aboard a rocket

    International Nuclear Information System (INIS)

    Schrage, D.; Young, L.; Campbell, B.; Billen, J.H.; Stovall, J.; Martinez, F.; Clark, W.; Bolme, G.; Gibbs, S.; King, D.; O'Shea, P.; Butler, T.; Rathke, J.; Micich, R.; Rose, J.; Richter, R.; Rosato, G.

    1989-01-01

    Los Alamos National Laboratory, Grumman, and GAR Electroformers have completed the design and fabrication of an electroformed RFQ for the BEAR (beam experiments aboard a rocket) project. The design of this 1 m long, lightweight (< 55 kg accelerator incorporates four aluminum vane/cavity quadrants joined by an electroforming process. With the vane and cavity fabricated as a monolithic structure, there are no mechanical rf, vacuum or structural joints. The completed BEAR RFQ has successfully passed flight qualification and beam transport tests in preparation for the flight, which is scheduled for March 1989. (orig.)

  3. In-flight radiation measurements aboard French airliners

    International Nuclear Information System (INIS)

    Montagne, C.; Donne, J.P.; Pelcot, D.; Nguyen, V.D.; Bouisset, P.; Kerlau, G.

    1993-01-01

    Routine radiation monitoring has been carried out for more than 15 years aboard Air France airliners. Annual dose received by aircrews can be estimated in the 2-3 mSv range for subsonic long-haul aircrews. Recent dosimetric measurements, using CIRCE devices based on low-pressure TEPC microdosimetry techniques and by using new types of bubble damage detectors, seem to confirm partly these results. More investigations by these new techniques could be undertaken at other phases of the 11 year solar cycle. (author)

  4. BEAR RFQ-beam experiment aboard a rocket

    Energy Technology Data Exchange (ETDEWEB)

    Schrage, D.; Young, L.; Campbell, B.; Billen, J.H.; Stovall, J.; Martinez, F.; Clark, W.; Bolme, G.; Gibbs, S.; King, D.; O' Shea, P.; Butler, T. (Los Alamos National Lab., NM (USA)); Rathke, J.; Micich, R.; Rose, J. (Grumman Space Systems, Bethpage, NY (USA)); Richter, R.; Rosato, G. (GAR Electroformers, Danbury, CT (USA))

    1989-04-01

    Los Alamos National Laboratory, Grumman, and GAR Electroformers have completed the design and fabrication of an electroformed RFQ for the BEAR (beam experiments aboard a rocket) project. The design of this 1 m long, lightweight < 55 kg accelerator incorporates four aluminum vane/cavity quadrants joined by an electroforming process. With the vane and cavity fabricated as a monolithic structure, there are no mechanical rf, vacuum or structural joints. The completed BEAR RFQ has successfully passed flight qualification and beam transport tests in preparation for the flight, which is scheduled for March 1989. (orig.).

  5. The Lowest Spin and Parity Levels on Two Particle System for Odd-oddNuclei 60Co and 46K

    International Nuclear Information System (INIS)

    Wardhani, VIS; Siagian, Toga

    2000-01-01

    For obtaining the lowest spin and parity levels of odd-odd nuclei, theanalyzing of the nuclei 60 Co and 46 K has been done using delta forcemodel. The calculation is done by theoretically and compared with experiment.To get a result optimally, the data analyzed using least square method. It isshown that the lowest spin and parity level from calculation result and theexperiment result are similar. (author)

  6. Estimating of aquifer parameters from the single-well water-level measurements in response to advancing longwall mine by using particle swarm optimization

    Science.gov (United States)

    Buyuk, Ersin; Karaman, Abdullah

    2017-04-01

    We estimated transmissivity and storage coefficient values from the single well water-level measurements positioned ahead of the mining face by using particle swarm optimization (PSO) technique. The water-level response to the advancing mining face contains an semi-analytical function that is not suitable for conventional inversion shemes because the partial derivative is difficult to calculate . Morever, the logaritmic behaviour of the model create difficulty for obtaining an initial model that may lead to a stable convergence. The PSO appears to obtain a reliable solution that produce a reasonable fit between water-level data and model function response. Optimization methods have been used to find optimum conditions consisting either minimum or maximum of a given objective function with regard to some criteria. Unlike PSO, traditional non-linear optimization methods have been used for many hydrogeologic and geophysical engineering problems. These methods indicate some difficulties such as dependencies to initial model, evolution of the partial derivatives that is required while linearizing the model and trapping at local optimum. Recently, Particle swarm optimization (PSO) became the focus of modern global optimization method that is inspired from the social behaviour of birds of swarms, and appears to be a reliable and powerful algorithms for complex engineering applications. PSO that is not dependent on an initial model, and non-derivative stochastic process appears to be capable of searching all possible solutions in the model space either around local or global optimum points.

  7. Promoting smoke-free homes: a novel behavioral intervention using real-time audio-visual feedback on airborne particle levels.

    Directory of Open Access Journals (Sweden)

    Neil E Klepeis

    Full Text Available Interventions are needed to protect the health of children who live with smokers. We pilot-tested a real-time intervention for promoting behavior change in homes that reduces second hand tobacco smoke (SHS levels. The intervention uses a monitor and feedback system to provide immediate auditory and visual signals triggered at defined thresholds of fine particle concentration. Dynamic graphs of real-time particle levels are also shown on a computer screen. We experimentally evaluated the system, field-tested it in homes with smokers, and conducted focus groups to obtain general opinions. Laboratory tests of the monitor demonstrated SHS sensitivity, stability, precision equivalent to at least 1 µg/m(3, and low noise. A linear relationship (R(2 = 0.98 was observed between the monitor and average SHS mass concentrations up to 150 µg/m(3. Focus groups and interviews with intervention participants showed in-home use to be acceptable and feasible. The intervention was evaluated in 3 homes with combined baseline and intervention periods lasting 9 to 15 full days. Two families modified their behavior by opening windows or doors, smoking outdoors, or smoking less. We observed evidence of lower SHS levels in these homes. The remaining household voiced reluctance to changing their smoking activity and did not exhibit lower SHS levels in main smoking areas or clear behavior change; however, family members expressed receptivity to smoking outdoors. This study established the feasibility of the real-time intervention, laying the groundwork for controlled trials with larger sample sizes. Visual and auditory cues may prompt family members to take immediate action to reduce SHS levels. Dynamic graphs of SHS levels may help families make decisions about specific mitigation approaches.

  8. Rumen fermentation, blood metabolites, and growth performance of calves during transition from liquid to solid feed: Effects of dietary level and particle size of alfalfa hay.

    Science.gov (United States)

    Nemati, M; Amanlou, H; Khorvash, M; Moshiri, B; Mirzaei, M; Khan, M A; Ghaffari, M H

    2015-10-01

    This study evaluated the effects of particle size (PS) and dietary level of alfalfa hay (AH) on rumen fermentation parameters, blood metabolites, eating behavior, and growth performance in dairy calves during transition from liquid to solid feed. Sixty newborn dairy calves (41 ± 2.5,kg of body weight) were used in a 2 × 2 factorial arrangement with the factors dietary AH level (medium, 12.5%, or high, 25%, on DM basis) and PS (fine = 1mm or medium = 3mm, as geometric means) of AH. Hence, the dietary treatments were (1) medium level of AH with fine PS (M-FPS), (2) medium level of AH with medium PS (M-MPS), (3) high level of AH with fine PS (H-FPS), and (4) high level of AH with medium PS (H-MPS). Particle size of AH did not affect total DMI (TDMI) during the preweaning period, although TDMI was greater for calves fed MPS than in those fed FPS during the postweaning and overall periods. Calves fed MPS spent more time eating solid feed and ruminating and less time on nonnutritive oral behaviors compared with FPS calves. The dietary level of AH did not affect behavioral parameters. Average daily gain of calves was not affected by dietary treatment before weaning. During the postweaning and overall periods, average daily gain was greater in calves fed MPS than in those fed FPS at the 25% AH level, but this effect was absent with 12.5% AH. Furthermore, the rumen pH values on d 35 and 70 of the study were greater for MPS than for FPS, regardless of the dietary level of AH. Effects of AH level, PS, and their interaction did not affect blood glucose concentrations in developing calves. These results indicate that feed intake, feeding behavior, rumen fermentation parameters, and blood β-hydroxybutyrate concentration may be affected by rations differing in forage PS; thus, providing calves with MPS can improve calf performance and reduce their nonnutritive oral behaviors. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  9. [Pollution Level and Source Apportionment of Atmospheric Particles PM₂.₅ in Southwest Suburb of Chengdu in Spring].

    Science.gov (United States)

    Lin, Yu; Ye, Zhi-xiang; Yang, Huai-jin; Zhang, Ju; Yin, Wei-wen; Li, Xiao-fen

    2016-05-15

    In order to understand the characteristics of PM₂.₅ pollution in the atmosphere of Chengdu southwest suburb, PM₂.₅ particles in Chengdu southwest suburb were collected and analyzed from March 18 to March 31st, 2015. The results showed that the daily average concentration of PM₂.₅ in the southwest suburb of Chengdu reached 121.21 µg · m⁻³, and the average daily concentration of 24 samples in 31 PM₂.₅ samples was over 75 µg · m⁻³, the daily excessive rate was 77%, indicating the PM₂.₅ pollution in the study area was serious in March. When studying the relationship between atmospheric and meteorological factors, it was found that there was a significant index correlation between PM₂.₅ concentration and atmospheric visibility, and it had a positive correlation with temperature and humidity, but the correlation was not obvious. NH₄⁺ (16.24%), SO₄²- (12.58%) and NO₃⁻ (9.91%) were dominant in PM₂.₅ The ratio of NO₃⁻/SO₄²⁻ was 0.77, which indicated that the pollution of stationary sources in the southwest suburb was more severe than that of mobile sources. Organic carbon (OC)/elemental carbon (EC) ratios were higher than 2, which indicated the existence of second organic carbon (SOC). Using OC/EC ratio method to estimate the concentration of SOC, it was found that the average concentration of SOC in the southwest suburb of Chengdu in March was 3.49 µ · m⁻³, and the contribution rate of OC was 20.6%, which showed that the main source of OC in the southwest suburb of Chengdu was primary discharge. The correlation analysis of OC and EC showed that the correlation coefficient reached 0.95, indicating that the OC and EC sources were similar and relatively stable, and there was a great impact of local source emissions on Chengdu southwest suburb in spring, and primary discharge played a dominant role, while the contribution of SOC to OC was relatively small, which was consistent with the SOC characteristics obtained

  10. Energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in electric and magnetic fields

    International Nuclear Information System (INIS)

    Cruz, Philip Christopher S.; Bernardo, Reginald Christian S.; Esguerra, Jose Perico H.

    2017-01-01

    We calculate the energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in uniform electric and magnetic fields. Using separation of variables method and a change of independent variable, we show that the problem can be reduced to a one-dimensional Schrödinger equation for a periodic potential. The effects of varying the shape of the cross-section while keeping the same perimeter and the strengths of the electric and magnetic fields are investigated for elliptical, corrugated, and nearly-rectangular tubes with radial dimensions of the order of a nanometer. The geometric potential has minima at the angular positions where there is a significant amount of curvature. For the elliptical and corrugated tubes, it is shown that as the tube departs from the circular shape of cross-section the double-degeneracy between the energy levels is lifted. For the nearly-rectangular tube, it is shown that energy level crossings occur as the horizontal dimension of the tube is varied while keeping the same perimeter and radius of circular corners. The interplay between the curvature and the strength of the electric and magnetic fields determines the overall behavior of the energy levels. As the strength of the electric field increases, the overall potential gets skewed creating a potential well on the side corresponding to the more negative electric potential. The energy levels of the first few excited states approach more positive values while the ground state energy level approaches a more negative value. For large electric fields, all bound state energy levels tend to more negative values. The contribution of weak magnetic fields to the overall potential behaves in the same way as the electric field contribution but with its sign depending on the direction of the component of the momentum parallel to the cylindrical axis. Large magnetic fields lead to pairing of energy levels reminiscent of 2D Landau levels for the elliptical and nearly

  11. Energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in electric and magnetic fields

    Energy Technology Data Exchange (ETDEWEB)

    Cruz, Philip Christopher S., E-mail: pscruz1@up.edu.ph; Bernardo, Reginald Christian S., E-mail: rcbernardo@nip.upd.edu.ph; Esguerra, Jose Perico H., E-mail: jesguerra@nip.upd.edu.ph

    2017-04-15

    We calculate the energy levels of a quantum particle on a cylindrical surface with non-circular cross-section in uniform electric and magnetic fields. Using separation of variables method and a change of independent variable, we show that the problem can be reduced to a one-dimensional Schrödinger equation for a periodic potential. The effects of varying the shape of the cross-section while keeping the same perimeter and the strengths of the electric and magnetic fields are investigated for elliptical, corrugated, and nearly-rectangular tubes with radial dimensions of the order of a nanometer. The geometric potential has minima at the angular positions where there is a significant amount of curvature. For the elliptical and corrugated tubes, it is shown that as the tube departs from the circular shape of cross-section the double-degeneracy between the energy levels is lifted. For the nearly-rectangular tube, it is shown that energy level crossings occur as the horizontal dimension of the tube is varied while keeping the same perimeter and radius of circular corners. The interplay between the curvature and the strength of the electric and magnetic fields determines the overall behavior of the energy levels. As the strength of the electric field increases, the overall potential gets skewed creating a potential well on the side corresponding to the more negative electric potential. The energy levels of the first few excited states approach more positive values while the ground state energy level approaches a more negative value. For large electric fields, all bound state energy levels tend to more negative values. The contribution of weak magnetic fields to the overall potential behaves in the same way as the electric field contribution but with its sign depending on the direction of the component of the momentum parallel to the cylindrical axis. Large magnetic fields lead to pairing of energy levels reminiscent of 2D Landau levels for the elliptical and nearly

  12. Landau levels from neutral Bogoliubov particles in two-dimensional nodal superconductors under strain and doping gradients

    Science.gov (United States)

    Nica, Emilian M.; Franz, Marcel

    2018-02-01

    Motivated by recent work on strain-induced pseudomagnetic fields in Dirac and Weyl semimetals, we analyze the possibility of analogous fields in two-dimensional nodal superconductors. We consider the prototypical case of a d -wave superconductor, a representative of the cuprate family, and find that the presence of weak, spatially varying strain leads to pseudomagnetic fields and Landau quantization of Bogoliubov quasiparticles in the low-energy sector. A similar effect is induced by the presence of generic, weak doping gradients. In contrast to genuine magnetic fields in superconductors, the strain- and doping-gradient-induced pseudomagnetic fields couple in a way that preserves time-reversal symmetry and is not subject to the screening associated with the Meissner effect. These effects can be probed by tuning weak applied supercurrents which lead to shifts in the energies of the Landau levels and hence to quantum oscillations in thermodynamic and transport quantities.

  13. Level and Contamination Assessment of Environmentally Sensitive Elements in Smaller than 100 μm Street Dust Particles from Xining, China

    Directory of Open Access Journals (Sweden)

    Ni Zhao

    2014-02-01

    Full Text Available Concentrations of the environmentally sensitive elements (ESEs As, Co, Cu, Mn, Ni, Pb, V and Zn in smaller than 100 μm street dust particles from Xining were measured using X-ray fluorescence spectrometry and their contamination levels were assessed based on enrichment factor (EF, geoaccumulation index (Igeo and pollution load index (PLI. The concentrations of As, Co, Cu, Mn, Ni, Pb, V and Zn in smaller than 100 μm street dust particles from Xining are 0.1–0.8, 2.7–10.9, 0.7–5.2, 0.3–1.1, 0.6–2.5, 1.2–11.1, 0.7–1.3 and 0.4–2.9 times the background values of Qinghai soil, respectively. The calculated EF and Igeo values reveal the order Co > Pb > Cu > Zn > V > Ni > Mn > As. The EF and Igeo values of Co, Cu, Pb and Zn are higher indicating that there is considerable pollution by these elements in smaller than 100 μm street dust particles, especially for Co. The EF and Igeo of Mn, Ni and V are lower and the assessment results indicate an absence of distinct Mn, Ni and V pollution in the studied samples. The mean value of PLIsite is 1.14, indicating a slightly pollution in the whole city of Xining. The order of PLIarea for the five tested districts is Center District (CD > East District (ED > West District (WD > North District (ND > South District (SD, showing that ESEs pollution in the South District is the lightest while it is the highest in the Central District.

  14. Exposure to ultrafine carbon particles at levels below detectable pulmonary inflammation affects cardiovascular performance in spontaneously hypertensive rats

    Directory of Open Access Journals (Sweden)

    Bader Michael

    2008-12-01

    Full Text Available Abstract Background Exposure to particulate matter is a risk factor for cardiopulmonary disease but the underlying molecular mechanisms remain poorly understood. In the present study we sought to investigate the cardiopulmonary responses on spontaneously hypertensive rats (SHRs following inhalation of UfCPs (24 h, 172 μg·m-3, to assess whether compromised animals (SHR exhibit a different response pattern compared to the previously studied healthy rats (WKY. Methods Cardiophysiological response in SHRs was analyzed using radiotelemetry. Blood pressure (BP and its biomarkers plasma renin-angiotensin system were also assessed. Lung and cardiac mRNA expressions for markers of oxidative stress (hemeoxygenase-1, blood coagulation (tissue factor, plasminogen activator inhibitor-1, and endothelial function (endothelin-1, and endothelin receptors A and B were analyzed following UfCPs exposure in SHRs. UfCPs-mediated inflammatory responses were assessed from broncho-alveolar-lavage fluid (BALF. Results Increased BP and heart rate (HR by about 5% with a lag of 1–3 days were detected in UfCPs exposed SHRs. Inflammatory markers of BALF, lung (pulmonary and blood (systemic were not affected. However, mRNA expression of hemeoxygenase-1, endothelin-1, endothelin receptors A and B, tissue factor, and plasminogen activator inhibitor showed a significant induction (~2.5-fold; p Conclusion Our finding shows that UfCPs exposure at levels which does not induce detectable pulmonary neutrophilic inflammation, triggers distinct effects in the lung and also at the systemic level in compromised SHRs. These effects are characterized by increased activity of plasma renin-angiotensin system and circulating white blood cells together with moderate increases in the BP, HR and decreases in heart rate variability. This systemic effect is associated with pulmonary, but not cardiac, mRNA induction of biomarkers reflective of oxidative stress; activation of vasoconstriction

  15. 78 FR 19172 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-29

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Parts 2 and 25 [IB Docket No. 12-376; FCC 12-161] Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit Space Stations... the Federal Register of March 8, 2013. The document proposed rules for Earth Stations Aboard Aircraft...

  16. No significant level of inheritable interchromosomal aberrations in the progeny of bystander primary human fibroblasts after alpha particle irradiation

    Science.gov (United States)

    Hu, Burong; Zhu, Jiayun; Zhou, Hongning; Hei, Tom K.

    2013-02-01

    A major concern for bystander effects is the probability that normal healthy cells adjacent to the irradiated cells become genomically unstable and undergo further carcinogenesis after therapeutic irradiation or space mission where astronauts are exposed to low dose of heavy ions. Genomic instability is a hallmark of cancer cells. In the present study, two irradiation protocols were performed in order to ensure pure populations of bystander cells and the genomic instability in their progeny were investigated. After irradiation, chromosomal aberrations of cells were analyzed at designated time points using G2 phase premature chromosome condensation (G2-PCC) coupled with Giemsa staining and with multiplex fluorescent in situ hybridization (mFISH). Our Giemsa staining assay demonstrated that elevated yields of chromatid breaks were induced in the progeny of pure bystander primary fibroblasts up to 20 days after irradiation. mFISH assay showed no significant level of inheritable interchromosomal aberrations were induced in the progeny of the bystander cell groups, while the fractions of gross aberrations (chromatid breaks or chromosomal breaks) significantly increased in some bystander cell groups. These results suggest that genomic instability occurred in the progeny of the irradiation associated bystander normal fibroblasts exclude the inheritable interchromosomal aberration.

  17. Assessing exposure to cosmic radiation aboard aircraft: the SIEVERT system

    International Nuclear Information System (INIS)

    Bottolier-Depois, J.F.; Clairand, I.; Blanchard, P.; Dessarps, P.; Lantos, P.

    2005-01-01

    Full text: The study of naturally-occurring radiation and its associated risk is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher on board aircraft that at ground level. Furthermore, its intensity depends on solar activity and eruptions. Due to their professional activity, flight crews and frequent flyers may receive an annual dose of some milliSieverts. This is why the European directive adopted in 1996 requires the aircraft operators to assess the dose and to inform their flight crews about the risk. The effective dose is to be estimated using various experimental and calculation means. In France, the computerized system for flight assessment of exposure to cosmic radiation in air transport (SIEVERT) is delivered to airlines for assisting them in the application of the European directive. This dose assessment tool was developed by the French General Directorate of Civil Aviation (DGAC) and partners: the Institute for Radiation Protection and Nuclear Safety (IRSN), the Paris Observatory and the French Institute for Polar Research - PaulEmile Victor (IPEV). This professional service is available since more than two years on an Internet server accessible to companies with a public section. The system provides doses that consider the routes flown by aircraft. Various results obtained are presented: experimental validation, in particular for the ground level event model (large solar eruption), and statistics on routes and personal doses. (author)

  18. Determination of the levels of particles PM10 and nitrogen dioxide at the city of Heredia, Costa Rica: 2005-2006

    International Nuclear Information System (INIS)

    Herrera-Murillo, Jorge; Rodriguez-Roman, Susana; Solis-Torres, Ligia Dina

    2009-01-01

    The levels of particulate matter PM 10 were determined at two sites of Heredia City (Rectory of the Universidad Nacional and Plazoleta del Fortin) of March to August 2006, obtaining as annual average 48 ± 8 and 31 ± 8 μg/m 3 , respectively. Also, the levels of sulfates, nitrates and chlorides were measured for both sites. The annual averages have resulted not to be significantly different for both sites, with a level of significance of 5%. In one of the ten sites of measurement of the concentration of nitrogen dioxide in the city, has presented higher values to the recommendation of the World Health Organization, monitoring for one month. The principal component analysis that were applied to the data of this gas, has showed that the variations in the levels are due to large-scale phenomena (meteorological). However, the concentration of sulfate present in the particulate matter has reached higher values to those recorded in cities like Rio de Janeiro and Mexico D.F., product probably of the high sulfur content present in the fuels that are used by the vehicle fleet at Costa Rica. The principal component analysis indicates that has existed a a strong correlation between the concentrations of sulfate and nitrate present in the particles PM 10 , pointing the contribution of anthropogenic sources. In the case of chloride, has highlighted the strong existing relationship with the meteorological parameters that were registered during the sampling period. (author) [es

  19. Evaluation of the levels of particles PM10 and nitrogen dioxide at the city of San Jose, Costa Rica: 2005-2006

    International Nuclear Information System (INIS)

    Herrera-Murillo, Jorge; Rodriguez Roman, Susana

    2009-01-01

    The levels of particulate matter PM 10 were determined at two sites of San Jose City (Catedral Metropolitana and Junta de Educacion), during a year (September 2005-September 2006), obtaining as annual average 36 ± 8 μg/m 3 and 25 ± 7 μg/m 3 , respectively. Also, the levels of sulfates, nitrates and chlorides were measured for both sites. The annual averages have resulted not to be significantly different for both sites, with a level of significance of 5%. Three of the fourteen sites of measurement of the concentration of nitrogen dioxide in the city, have presented higher values to the recommendation of the World Health Organization, monitoring for one month. The principal component analysis that were applied to the data of this gas, has showed that the variations in the levels are due to large-scale phenomena (meteorological). However, the concentration of sulfate present in the particulate matter has reached higher values to those recorded in cities like Rio de Janeiro and Mexico D.F., product probably of the high sulfur content present in the fuels that are used by the vehicle fleet at Costa Rica. The principal component analysis indicates that has existed a strong correlation between the concentrations of sulfate and nitrate present in the particles PM 10 , pointing the contribution of anthropogenic sources. In the case of chloride, has highlighted the strong existing relationship with the meteorological parameters that were registered during the sampling period. (author) [es

  20. Determination of elemental concentrations at trace levels in alumina by charged particle activation analysis using proton beam from VEC accelerator

    International Nuclear Information System (INIS)

    Datta, J.; Dasgupta, S.; Chowdhury, D.P.; Verma, R.

    2015-01-01

    The elemental impurities have been determined in high purity alumina material used in nuclear reactors at ppb (μg kg -1 ) to ppm (mg kg -1 ) levels by CPAA using proton beam from VEC machine. Proton beam has the advantage of high cross section for (p, n) reaction to produce suitable nuclide for activation analysis by instrumental approach. The cross sections of higher reaction channels like (p, 2n), (p, pn) are found to be less than 1 mb below 13 MeV proton by theoretical calculation using ALICE 91 computer code. Therefore, 13 MeV proton beam was used to irradiate the alumina samples along with standards, Lake (IAEA-SL -1 ) and Marine (PACS-2) sediments, both in pellet and powder forms. The irradiation was carried out with 50 nA to 1μA beam current for 10 min to 10 h depending on types of samples and standards. The beam current was measured by Faraday cup and also checked by putting Ti monitoring foil before the target. Ni is determined by (p, pn) reaction using 18 MeV proton as there is no suitable product from (p, n) reaction. The counting measurements of irradiated samples were performed with a high resolution γ-spectrometer using HPGe detector (relative efficiency - 40%, resolution - 2.0 keV at 1332 keV) coupled to a PC based 8 k MCA. The validation of the CPAA results has been carried out by INAA with the same alumina samples, carried out in Dhruva reactor with neutron flux 10 14 cm 2 s -1 using standards IAEA-SL-1 and PACS-2

  1. Power level control of the TRIGA Mark-II research reactor using the multifeedback layer neural network and the particle swarm optimization

    International Nuclear Information System (INIS)

    Coban, Ramazan

    2014-01-01

    Highlights: • A multifeedback-layer neural network controller is presented for a research reactor. • Off-line learning of the MFLNN is accomplished by the PSO algorithm. • The results revealed that the MFLNN–PSO controller has a remarkable performance. - Abstract: In this paper, an artificial neural network controller is presented using the Multifeedback-Layer Neural Network (MFLNN), which is a recently proposed recurrent neural network, for neutronic power level control of a nuclear research reactor. Off-line learning of the MFLNN is accomplished by the Particle Swarm Optimization (PSO) algorithm. The MFLNN-PSO controller design is based on a nonlinear model of the TRIGA Mark-II research reactor. The learning and the test processes are implemented by means of a computer program at different power levels. The simulation results obtained reveal that the MFLNN-PSO controller has a remarkable performance on the neutronic power level control of the reactor for tracking the step reference power trajectories

  2. Radiobiological experiments with plant seeds aboard the biosatellite Kosmos 1887

    International Nuclear Information System (INIS)

    Anikeeva, I.D.; Vaulina, E.N.; Kostina, L.N.; Benton, E.V.

    1990-01-01

    The effects of spaceflight factors on the seeds of Arabidopsis thaliana and Crepis capillaris were studied. The seeds were located either inside the satellite or in open space, protected with aluminium foil or exposed without the foil cover. When the seeds were in open space without any protection, their viability was found to be suppressed; the survival rate and fertility of plants grown from these seeds were also diminished. An increase in the frequency of chromosome aberrations (CA) and in the number of multiple injuries was registered in this case. Experiments with the aluminium foil shielding showed a decrease in the suppression of the seeds' viability, but mutational changes were found to be even more increased, while the survival rate and fertility of the plants decreased. An increase in the thickness of shielding resulted in a decrease in the effects up to the level of the control, except for the effects connected with CA and fertility of the plants. Analysis of the results shows that these impairments can be ascribed to the action of single heavy charged particles. The seeds can be thus regarded as an integral biological 'dosimeter' which allows estimation of the total effects of radiation, ecological and biological factors. (author)

  3. Assessing exposure to cosmic radiation aboard aircraft: the Sievert system

    International Nuclear Information System (INIS)

    Bottollier-Depois, J.F.; Biau, A.; Clairand, I.; Saint-Lo, D.; Valero, M.; Blanchard, P.; Dessarps, P.; Lantos, P.

    2003-01-01

    The study of naturally-occurring radiation and its associated risk is one of the preoccupations of bodies responsible for radiation protection. Cosmic particle flux is significantly higher on board aircraft that at ground level. Furthermore, its intensity depends on solar activity and eruptions. Due to their professional activity, flight crews and frequent flyers may receive an annual dose of some milli-sieverts. This is why the European directive adopted in 1996 requires the aircraft operators to assess the dose and to inform their flight crews about the risk. The effective dose is to be estimated using various experimental and calculation means. In France, the computerized system for flight assessment of exposure to cosmic radiation in air transport (SIEVERT) is delivered to airlines for assisting them in the application of the European directive. This dose assessment tool was developed by the French General Directorate of Civil Aviation (DGAC) and partners: the Institute for Radiation Protection and Nuclear Safety (IRSN), the Paris Observatory and the French Institute for Polar Research - Paul-Emile Victor (IPEV). This professional service is available on an Internet server accessible to companies with a public section. The system provides doses that consider the routes flown by aircraft Various results obtained are presented. (authors)

  4. Determination of concentration levels of arsenic, gold and antimony in particle-size fractions of gold ore using Neutron Activation Analysis

    International Nuclear Information System (INIS)

    Nyarku, M.

    2009-02-01

    Instrumental Neutron Activation Analysis (INAA) has been used to quantify the concentrations of arsenic, gold and antimony in particle-size fractions of a gold ore. The ore, which was taken from the Ahafo project site of Newmont Ghana Gold Ltd, was first fractionated into fourteen (14) particle-size fractions using state-of-the-art analytical sieve machine. The minimum sieve mesh size used was 36 microns and grains >2000 microns were not considered for analysis. Results of the sieving were analysed with easysieve software. The < 36 microns sub fraction was found to be the optimum, hosting bulk of all three elements. For arsenic, the element was found to be highly concentrated in < 36 to +100 microns size fractions and erratically distributed from +150 microns fraction and above. For gold, in exception of the sub fraction <36 which had exceptionally high concentration, the element is distributed in all the size fractions but slightly 'plays out' in the +150 to +400 microns fractions. Antimony occurrence in the sample was relatively high in <36 microns size fraction followed by 600 - 800, 800 - 1000, 400 - 600 and 36 - 40 microns size fractions in that order. Gold content in the sample was far higher than that of arsenic and antimony. Gold concentration in the composite sample was in the range 564 - 8420 ppm. Arsenic levels were higher as compared to antimony. The range of arsenic concentration in the composite sample was 14.33 - 186.92 ppm. Antimony concentration was in the range 1.09 - 9.48 ppm. (au)

  5. Development of particle filters for ships; Udvikling af partikelfiltre til skibe

    Energy Technology Data Exchange (ETDEWEB)

    Jakobsen, O.; Norre Holm, J.; Koecks, M. [Teknologisk Institut, Aarhus (Denmark)

    2013-04-01

    The project has resulted in a solution with a well-functioning maritime particle filter which reduces the particle emission significantly. The visible smoke from the vessels funnel, which typically is seen while manoeuvring in the harbour, is also reduced to a minimum. The system is constructed in such a way that the exhaust gases can be bypassed around the filter unit, in this situation to ensure the engines operation in case of filter clogging. The system has been provided with safety functions to prevent an excessive exhaust gas back-pressure and there are fitted remote controlled exhaust valves. Some of the challenges in the project have been the requirement from the engine manufacturer of keeping a low turbocharger back-pressure, besides the space conditions aboard the test vessel and the achievement of sufficient temperatures for regeneration of the particle filter. To oppose the requirement of low exhaust gas back-pressure, the filter housing was designed with space for twice as many monoliths as originally planned. In the funnel casing the original installations were removed to make space for the filter housing, and the system was enlarged with electrically controlled exhaust valves to improve the daily operation of the crew. The regeneration issue was solved by mounting electric automatically controlled heating elements in the filter housing and by an ash exhaust system. Regeneration is carried out by the crew when the vessel lies in harbour in the evening after the last tour of the day. Before mounting the particle filter, measurements were carried out aboard, showing a compound of particle emissions with an expected high NO{sub x}-level of 8.33 g/kW, whereas the other emissions were lower than expected at first. Especially HC and CO were very low, but also the particle mass (PM) had a relatively low value of 0.22 g/kWh. After commissioning the particle filter, a significant reduction of 93% of the particle number (N) was observed. A reduction in N was

  6. New particles

    Energy Technology Data Exchange (ETDEWEB)

    Khare, A.

    1980-07-01

    Current state of art in the discovery of new elementary particles is reviewed. At present, quarks and mesons are accepted as the basic constituents of matter. The charmonium model (canti-c system), and the 'open charm' are discussed. Explanations are offered for the recent discovery of the heavy lepton tau. Quark states such as the beauty and taste are also dealt with at length. The properties of the tanti-t bound system are speculated. It is concluded that the understanding of canti-c and banti-b families is facilitated by the assumption of the quarkonium model. Implications at the astrophysical level are indicated.

  7. Virus-like particle production with yeast: ultrastructural and immunocytochemical insights into Pichia pastoris producing high levels of the Hepatitis B surface antigen

    Directory of Open Access Journals (Sweden)

    Adnan Ahmad

    2011-06-01

    Full Text Available Abstract Background A protective immune response against Hepatitis B infection can be obtained through the administration of a single viral polypeptide, the Hepatitis B surface antigen (HBsAg. Thus, the Hepatitis B vaccine is generated through the utilization of recombinant DNA technology, preferentially by using yeast-based expression systems. However, the polypeptide needs to assemble into spherical particles, so-called virus-like particles (VLPs, to elicit the required protective immune response. So far, no clear evidence has been presented showing whether HBsAg assembles in vivo inside the yeast cell into VLPs or later in vitro during down-stream processing and purification. Results High level production of HBsAg was carried out with recombinant Pichia pastoris using the methanol inducible AOX1 expression system. The recombinant vaccine was isolated in form of VLPs after several down-stream steps from detergent-treated cell lysates. Search for the intracellular localization of the antigen using electron microscopic studies in combination with immunogold labeling revealed the presence of HBsAg in an extended endoplasmic reticulum where it was found to assemble into defined multi-layered, lamellar structures. The distance between two layers was determined as ~6 nm indicating that these lamellas represent monolayers of well-ordered HBsAg subunits. We did not find any evidence for the presence of VLPs within the endoplasmic reticulum or other parts of the yeast cell. Conclusions It is concluded that high level production and intrinsic slow HBsAg VLP assembly kinetics are leading to retention and accumulation of the antigen in the endoplasmic reticulum where it assembles at least partly into defined lamellar structures. Further transport of HBsAg to the Golgi apparatus is impaired thus leading to secretory pathway disfunction and the formation of an extended endoplasmic reticulum which bulges into irregular cloud-shaped formations. As VLPs were

  8. Liquid penetrant and magnetic particle testing at level 2. Manual for the syllabi contained in IAEA-TECDOC-628, training guidelines in non-destructive testing techniques

    International Nuclear Information System (INIS)

    2000-01-01

    The International Atomic Energy Agency (IAEA) has been active in the promotion of non-destructive testing (NDT) technology in the world for many decades. The prime reason for this has been the need for stringent standards for quality control for safe operation of industrial as well a nuclear installations. It has successfully executed a number of programmes and regional projects of which NDT was an important part. Through these programmes a large number of persons have been trained in the member states and a state of self sufficiency in this area of technology has been achieved in many of them. All along there has been a realization of the need to have well established training guidelines and related books in order, firstly, to guide the IAEA experts who were involved in this training programme and, secondly, to achieve some level of international uniformity and harmonization of training materials and consequent competence of personnel. The syllabi for training courses have been published in the form of two TECDOC publications. The first was IAEA-TECDOC-407 which contained syllabi for the basic five methods, i.e. liquid penetrant testing, magnetic particle testing, eddy current testing, radiographic testing and ultrasonic testing, and the second and revised is IAEA-TECDOC-628 which includes additional methods of visual testing and leak testing. IAEA-TECDOC-628, as well as most of the international standards on the subject of training and certification of NDT personnel including ISO 9712, define three levels of competence, namely, Level 1, Level 2 and Level 3. Among these, Level 1 is the lowest and Level 3 the highest. The intermediate Level 2 is considered to be the most appropriate for persons who, beside other duties, are expected to independently undertake practical testing in the relevant method of NDT; develop NDT procedures adapted to various problems; prepare written instructions; make accept/reject decisions in accordance with relevant standards and

  9. Liquid penetrant and magnetic particle testing at level 2. Manual for the syllabi contained in IAEA-TECDOC-628, training guidelines in non-destructive testing techniques

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-02-01

    The International Atomic Energy Agency (IAEA) has been active in the promotion of non-destructive testing (NDT) technology in the world for many decades. The prime reason for this has been the need for stringent standards for quality control for safe operation of industrial as well a nuclear installations. It has successfully executed a number of programmes and regional projects of which NDT was an important part. Through these programmes a large number of persons have been trained in the member states and a state of self sufficiency in this area of technology has been achieved in many of them. All along there has been a realization of the need to have well established training guidelines and related books in order, firstly, to guide the IAEA experts who were involved in this training programme and, secondly, to achieve some level of international uniformity and harmonization of training materials and consequent competence of personnel. The syllabi for training courses have been published in the form of two TECDOC publications. The first was IAEA-TECDOC-407 which contained syllabi for the basic five methods, i.e. liquid penetrant testing, magnetic particle testing, eddy current testing, radiographic testing and ultrasonic testing, and the second and revised is IAEA-TECDOC-628 which includes additional methods of visual testing and leak testing. IAEA-TECDOC-628, as well as most of the international standards on the subject of training and certification of NDT personnel including ISO 9712, define three levels of competence, namely, Level 1, Level 2 and Level 3. Among these, Level 1 is the lowest and Level 3 the highest. The intermediate Level 2 is considered to be the most appropriate for persons who, beside other duties, are expected to independently undertake practical testing in the relevant method of NDT; develop NDT procedures adapted to various problems; prepare written instructions; make accept/reject decisions in accordance with relevant standards and

  10. Use of low density lipoprotein particle number levels as an aid in statin treatment decisions for intermediate risk patients: a cost-effectiveness analysis.

    Science.gov (United States)

    Shiffman, Dov; Arellano, Andre R; Caulfield, Michael P; Louie, Judy Z; Bare, Lance A; Devlin, James J; Melander, Olle

    2016-12-07

    The 2013 ACC/AHA guideline recommended either no statin therapy or moderate-intensity statin therapy (MST) for intermediate risk patients-those with 5-7.5% 10-year risk and without cardiovascular disease (CVD), hypercholesterolemia or diabetes. The guideline further suggested that the therapy choice be based on patient-clinician discussions of risks and benefits. Since low-density lipoprotein particle (LDL-P) levels were reported to be associated with CVD independently of traditional risk factors in intermediate and low risk patients, we investigated the cost-effectiveness of using LDL-P levels to identify intermediate risk patients likely to benefit from initiating or intensifying statin therapy. We evaluated 5 care strategies for intermediate risk patients. These included the strategies suggested by the guideline: no-statin therapy and MST. We compared each of these strategies to a related strategy that incorporated LDL-P testing. No-statin therapy was compared with the strategy of MST for those with high LDL-P levels and no statin therapy for all other patients (test-and-MST). MST was compared with the strategy of high-intensity statin therapy (HST) for those with high LDL-P levels and MST for all other patients (test-and-HST). We also evaluated the strategy of HST for all. Costs (payer perspective) and utilities were assessed over a 5-year time horizon in a Markov model of 100,000 hypothetical intermediate risk patients. HST dominated all other strategies, costing less and-despite causing 739 more cases of diabetes than did MST-resulting in more quality adjusted life-years (QALYs). For patient-clinician discussions that would otherwise lead to the MST strategy, we found the test-and-HST strategy reduced costs by $4.67 MM and resulted in 134 fewer CVD events and 115 additional QALYs. For patient-clinician discussions that would otherwise lead to no statin therapy, we found that the test-and-MST strategy reduced costs by $3.25 MM, resulted in 97 fewer CVD events

  11. Pregnancy outcomes after paternal radiofrequency field exposure aboard fast patrol boats.

    Science.gov (United States)

    Baste, Valborg; Moen, Bente E; Oftedal, Gunnhild; Strand, Leif Age; Bjørge, Line; Mild, Kjell Hansson

    2012-04-01

    To investigate adverse reproductive outcomes among male employees in the Royal Norwegian Navy exposed to radiofrequency electromagnetic fields aboard fast patrol boats. Cohort study of Royal Norwegian Navy servicemen linked to the Medical Birth Registry of Norway, including singleton offspring born between 1967 and 2008 (n = 37,920). Exposure during the last 3 months before conception (acute) and exposure more than 3 months before conception (nonacute) were analyzed. Perinatal mortality and preeclampsia increased after service aboard fast patrol boats during an acute period and also after increased estimated radiofrequency exposure during an acute period, compared with service aboard other vessels. No associations were found between nonacute exposure and any of the reproductive outcomes. Paternal work aboard fast patrol boats during an acute period was associated with perinatal mortality and preeclampsia, but the cause is not clear.

  12. Effects of Quartz Particle Size and Sucrose Addition on Melting Behavior of a Melter Feed for High-Level Waste Glass

    International Nuclear Information System (INIS)

    Marcial, Jose; Hrma, Pavel R.; Schweiger, Michael J.; Swearingen, Kevin J.; Tegrotenhuis, Nathan E.; Henager, Samuel H.

    2010-01-01

    The behavior of melter feed (a mixture of nuclear waste and glass-forming additives) during waste-glass processing has a significant impact on the rate of the vitrification process. We studied the effects of silica particle size and sucrose addition on the volumetric expansion (foaming) of a high-alumina feed and the rate of dissolution of silica particles in feed samples heated at 5 C/min up to 1200 C. The initial size of quartz particles in feed ranged from 5 to 195 (micro)m. The fraction of the sucrose added ranged from 0 to 0.20 g per g glass. Extensive foaming occurred only in feeds with 5-(micro)m quartz particles; particles (ge) 150 (micro)m formed clusters. Particles of 5 (micro)m completely dissolved by 900 C whereas particles (ge) 150 (micro)m did not fully dissolve even when the temperature reached 1200 C. Sucrose addition had virtually zero impact on both foaming and the dissolution of silica particles.

  13. Rare particles

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

    The use of Accelerator Mass Spectrometry (AMS) to search for hypothetical particles and known particles of rare processes is discussed. The hypothetical particles considered include fractionally charged particles, anomalously heavy isotopes, and superheavy elements. The known particles produced in rare processes discussed include doubly-charged negative ions, counting neutrino-produced atoms in detectors for solar neutrino detection, and the spontaneous emission of 14 C from 223 Ra. 35 references

  14. Decabrominated Diphenyl Ethers (BDE-209) in Chinese and Global Air: Levels, Gas/Particle Partitioning, and Long-Range Transport: Is Long-Range Transport of BDE-209 Really Governed by the Movement of Particles?

    Science.gov (United States)

    Li, Yi-Fan; Qiao, Li-Na; Ren, Nan-Qi; Sverko, Ed; Mackay, Donald; Macdonald, Robie W

    2017-01-17

    In this paper, we report air concentrations of BDE-209 in both gas- and particle-phases across China. The annual mean concentrations of BDE-209 were from below detection limit (BDL) to 77.0 pg·m -3 in the gas-phase and 1.06-728 pg·m -3 in the particle-phase. Among the nine PBDEs measured, BDE-209 is the dominant congener in Chinese atmosphere in both gas and particle phases. We predicted the partitioning behavior of BDE-209 in air using our newly developed steady state equation, and the results matched the monitoring data worldwide very well. It was found that the logarithm of the partition quotient of BDE-209 is a constant, and equal to -1.53 under the global ambient temperature range (from -50 to +50 °C). The gaseous fractions of BDE-209 in air depends on the concentration of total suspended particle (TSP). The most important conclusion derived from this study is that, BDE-209, like other semivolatile organic compounds (SVOCs), cannot be sorbed entirely to atmospheric particles; and there is a significant amount of gaseous BDE-209 in global atmosphere, which is subject to long-range atmospheric transport (LRAT). Therefore, it is not surprising that BDE-209 can enter the Arctic through LRAT mainly by air transport rather than by particle movement. This is a significant advancement in understanding the global transport process and the pathways entering the Arctic for chemicals with low volatility and high octanol-air partition coefficients, such as BDE-209.

  15. Association between magnetic field fluctuations and energetic particle bursts in the earth's magnetotail

    Science.gov (United States)

    Lui, A. T. Y.; Krimigis, S. M.; Armstrong, T. P.

    1982-01-01

    The association between energetic protons (0.29-0.50 MeV) and simultaneous local fluctuations of magnetic field at 35 to 45 earth radii in the magnetotail is examined statistically with data from APL/JHU particle telescopes aboard IMP 7 and IMP 8. About four satellite years of 5.5 min averaged measurements are used in this study. In addition to confirming that the level of magnetic field fluctuations generally increases with the presence of energetic protons and their streaming anisotropy, it is found that increases in occurrence frequency of streaming of energetic protons are ordered far better by magnetic field fluctuations than by proximity to the neutral sheet. However, the presence of large magnetic field fluctuations (delta B greater than 5 nT or delta B/B greater than 50%) is neither a necessary nor a sufficient condition for the detection of large streaming in energetic protons.

  16. Introduction to particle physics

    International Nuclear Information System (INIS)

    Zitoun, R.

    2000-01-01

    This book proposes an introduction to particle physics that requires only a high-school level mathematical knowledge. Elementary particles (leptons, quarks, bosons) are presented according to a modern view taking into account of their symmetries and interactions. The author shows how physicists have elaborated the standard model and what are its implications in cosmology. (J.S.)

  17. Teaching particle physics

    CERN Document Server

    Hanley, P

    2000-01-01

    Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students. (0 refs).

  18. Regolith X-Ray Imaging Spectrometer (REXIS) Aboard the OSIRIS-REx Asteroid Sample Return Mission

    Science.gov (United States)

    Masterson, R. A.; Chodas, M.; Bayley, L.; Allen, B.; Hong, J.; Biswas, P.; McMenamin, C.; Stout, K.; Bokhour, E.; Bralower, H.; Carte, D.; Chen, S.; Jones, M.; Kissel, S.; Schmidt, F.; Smith, M.; Sondecker, G.; Lim, L. F.; Lauretta, D. S.; Grindlay, J. E.; Binzel, R. P.

    2018-02-01

    The Regolith X-ray Imaging Spectrometer (REXIS) is the student collaboration experiment proposed and built by an MIT-Harvard team, launched aboard NASA's OSIRIS-REx asteroid sample return mission. REXIS complements the scientific investigations of other OSIRIS-REx instruments by determining the relative abundances of key elements present on the asteroid's surface by measuring the X-ray fluorescence spectrum (stimulated by the natural solar X-ray flux) over the range of energies 0.5 to 7 keV. REXIS consists of two components: a main imaging spectrometer with a coded aperture mask and a separate solar X-ray monitor to account for the Sun's variability. In addition to element abundance ratios (relative to Si) pinpointing the asteroid's most likely meteorite association, REXIS also maps elemental abundance variability across the asteroid's surface using the asteroid's rotation as well as the spacecraft's orbital motion. Image reconstruction at the highest resolution is facilitated by the coded aperture mask. Through this operation, REXIS will be the first application of X-ray coded aperture imaging to planetary surface mapping, making this student-built instrument a pathfinder toward future planetary exploration. To date, 60 students at the undergraduate and graduate levels have been involved with the REXIS project, with the hands-on experience translating to a dozen Master's and Ph.D. theses and other student publications.

  19. Pineal physiology in microgravity - Relation to rat gonadal function aboard Cosmos 1887

    Science.gov (United States)

    Holley, Daniel C.; Markley, Carol L.; Soliman, Magdi R. I.; Kaddis, Farida; Krasnov, Igor'

    1991-01-01

    Results are reported from an analysis of pineal glands obtained for five male rats flown aboard an orbiting satellite for their melatonin, serotonin (5-HT), 5-hydroxyindole acetic acid (5-HIA), and calcium content. Plasma 5-HT and 5-HIAA were measured. These parameters were compared to indicators of gonadal function: plasma testosterone concentration and spermatogonia development. Plasma melotonin was found to be low at the time of euthanasia and was not different among the experimental groups. Pineal calcium of flight animals was not different from ground controls. Pineal 5-HT and 5-HIAA in the flight group were significantly higher than those in ground controls. These findings suggest a possible increase in pineal 5-HT turnover in flight animals which may result in increased melatonin secretion. It is argued that the alteration of pinal 5-HT turnover and its expected effects on melatonin secretion may partially explain the lower plasma testosterone levels and 4-11 percent fewer spermatogonia cells observed in flight animals.

  20. Measurement of particle directions in low earth orbit with a Timepix

    International Nuclear Information System (INIS)

    Gohl, St.; Bergmann, B.; Granja, C.; Pichotka, M.; Polansky, S.; Pospisil, S.; Owens, A.

    2016-01-01

    In Low Earth Orbit (LEO) in space electronic equipment aboard satellites and space crews are exposed to high ionizing radiation levels. To reduce radiation damage and the exposure of astronauts, to improve shielding and to assess dose levels, it is valuable to know the composition of the radiation fields and particle directions. The presented measurements are carried out with the Space Application of Timepix Radiation Monitor (SATRAM). There, a Timepix detector (300 μm thick silicon sensor, pixel pitch 55 μm, 256 × 256 pixels) is attached to the Proba-V, an earth observing satellite of the European Space Agency (ESA). The Timepix detector's capability was used to determine the directions of energetic charged particles and their corresponding stopping powers. Data are continuously taken at an altitude of 820 km on a sun-synchronous orbit. The particles pitch angles with respect to the sensor layer were measured and converted to an Earth Centred Earth Fixed (ECEF) coordinate system. Deviations from an isotropic field are extracted by normalization of the observed angular distributions by a Geant4 Monte Carlo simulation —taking the systematics of the reconstruction algorithm and the pixelation into account.

  1. Logarithmic contributions in the particle-mass ratio to the fine shift of S energy levels of hydrogen-like atoms in the fifth order in the fine-structure constant

    International Nuclear Information System (INIS)

    Boikova, N.A.; Kleshchevskaya, S.V.; Tyukhtyaev, Yu.N.; Faustov, R.N.

    2004-01-01

    A high-precision investigation of a logarithmic contribution in the particle-mass ratio to the fine shift of the S energy levels of hydrogen-like atoms from the exchange of a Coulomb photon is performed. It is shown that diagrams describing the exchange of one transverse photon and two Coulomb photons do not make such contributions

  2. Particle detection

    International Nuclear Information System (INIS)

    Charpak, G.

    2000-01-01

    In this article G.Charpak presents the principles on which particle detection is based. Particle accelerators are becoming more and more powerful and require new detectors able to track the right particle in a huge flux of particles. The gigantic size of detectors in high energy physics is often due to the necessity of getting a long enough trajectory in a magnetic field in order to deduce from the curvature an accurate account of impulses in the reaction. (A.C.)

  3. Strange particles

    International Nuclear Information System (INIS)

    Chinowsky, W.

    1989-01-01

    Work done in the mid 1950s at Brookhaven National Laboratory on strange particles is described. Experiments were done on the Cosmotron. The author describes his own and others' work on neutral kaons, lambda and theta particles and points out the theoretical gap between predictions and experimental findings. By the end of the decade, the theory of strange particles was better understood. (UK)

  4. An new derivation of the Marshalek-Okubo realization of the shell-model algebra SO(2ν+1) for even and odd systems with ν single-particle levels

    International Nuclear Information System (INIS)

    Klein, A.; Marshalek, E.R.

    1988-01-01

    In recent years, the method for unitarizing nonunitary Dyson boson realizations of shell-model algebras has been both generalized and substantially simplified through the introduction of overtly group-theoretical methods. In this paper, these methods are applied to the boson-odd-particle realization of the algebra SO(2ν+1) for ν single-particle levels, adapted to the group chain SO(2ν+1) contains SO(2ν) contains U(ν), which Marshalek first derived by brute force summation of a Taylor expansion and later Okubo by a largely algebraic technique. (orig.)

  5. A Case Study of Project ATHENA: Tactical Level Technological Innovation Aboard the USS Benfold

    Science.gov (United States)

    2014-12-01

    frequently cited as a fundamental contributor to the laborious and often-disappointing acquisition process. While entire text books are filled with... secondhand accounts and archival records instead of personal observation to chronicle the project from its inception. Fortunately, the researcher had...social phenomenon (Strauss & Glaser, 1999). John Creswell (2009) further elaborates on the merits of qualitative research in his book Research Design

  6. Low-level radioactive river sediment particles originating from the Chalk river nuclear site carry a mixture of radionuclides and metals

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Ole Christian; Cagno, Simone; Salbu, Brit [Norwegian University of Life Sciences - NMBU, Center of Excellence in Environmental Radioactivity - CERAD, P.O. Box 5003, N-1432 Aas (Norway); Falkenberg, Gerald [Photon science, DESY, Hamburg (Germany); Janssens, Koen; Nuyts, Gert; Vanmeert, Frederik [AXIL, Department of Chemistry, University of Antwerpen (Belgium); Jaroszewicz, Jakub [Faculty of Materials Science and Engineering, Warsaw University of Technology, Warsaw (Poland); Priest, Nicholas D.; Audet, Marc [Nuclear Science Division, AECL Chalk River Laboratories (Canada)

    2014-07-01

    The Chalk River Laboratory of Atomic Energy of Canada Ltd., site is located on the Ottawa River approximately 200 km northwest of Ottawa, Canada. The site has two large research reactors: NRX, which operated from 1947 to 1991 and NRU, which continues to operate and is used to produce a significant fraction of the world's supply of medical isotopes. During the course of the operation of the NRX reactor small quantities of radioactive particles were discharged to the Ottawa River through a process sewer discharge pipe. These are now located in river bed sediments within a 0.08 km² area close to the discharge pipe. In the present study, selected particles were isolated from riverbed sediments. These were then characterized by environmental scanning electron microscopy with energy dispersive micro X-ray analysis (ESEM-EDX). This was undertaken to obtain information on particle size, structure and the distribution of elements across particle surfaces. Based on the results of ESEM-EDX, particles were selected for X-ray absorption nano-tomography analysis, which provides videos showing the 3D density distribution of the particles. Furthermore, 2D and 3D Synchrotron Radiation based X-ray techniques (micro-X-ray fluorescence; micro-XRF, micro-X-ray absorption near edge spectroscopy; micro-XANES and micro-X-ray diffraction; micro-XRD) with submicron resolution (beam size 0.5 μm) were employed to investigate the elemental and phase composition (micro-XRF/XRD) and oxidation states (micro-XANES) of matrix elements with high spatial resolution and sensitivity. Results show that the particles investigated so far varied according to: 1) <~40 μm diameter sized U fuel particles similar in structure to particles observed from Chernobyl and Krasnoyarsk-26 and 2) larger particles with diameters up to several hundred μm. The larger particles comprised a matrix of low density, sediment material with high density inclusions that contained a range of metals including Cu, Cr, As

  7. Perspectives on chemical oceanography in the 21st century: Participants of the COME ABOARD Meeting examine aspects of the field in the context of 40 years of DISCO

    Science.gov (United States)

    Fassbender, Andrea J.; Palevsky, Hilary I.; Martz, Todd R.; Ingalls, Anitra E.; Gledhill, Martha; Fawcett, Sarah E.; Brandes, Jay; Aluwihare, Lihini; Anderson, Robert M.; Bender, Sara; Boyle, Ed; Bronk, Debbie; Buesseler, Ken; Burdige, David J.; Casciotti, Karen; Close, Hilary; Conte, Maureen; Cutter, Greg; Estapa, Meg; Fennel, Katja; Ferron, Sara; Glazer, Brian; Goni, Miguel; Grand, Max; Guay, Chris; Hatta, Mariko; Hayes, Chris; Horner, Tristan; Ingall, Ellery; Johnson, Kenneth G.; Juranek, Laurie; Knapp, Angela; Lam, Phoebe; Luther, George; Matrai, Paty; Nicholson, David; Paytan, Adina; Pellenbarg, Robert; Popendorf, Kim; Reddy, Christopher M.; Ruttenberg, Kathleen; Sabine, Chris; Sansone, Frank; Shaltout, Nayrah; Sikes, Liz; Sundquist, Eric T.; Valentine, David; Wang, Zhao (Aleck); Wilson, Sam; Barrett, Pamela; Behrens, Melanie; Belcher, Anna; Biermann, Lauren; Boiteau, Rene; Clarke, Jennifer; Collins, Jamie; Coppola, Alysha; Ebling, Alina M.; Garcia-Tigreros, Fenix; Goldman, Johanna; Guallart, Elisa F.; Haskell, William; Hurley, Sarah; Janssen, David; Johnson, Winn; Lennhartz, Sinikka; Liu, Shuting; Rahman, Shaily; Ray, Daisy; Sarkar, Amit; Steiner, Zvika; Widner, Brittany; Yang, Bo

    2017-01-01

    The questions that chemical oceanographers prioritize over the coming decades, and the methods we use to address these questions, will define our field's contribution to 21st century science. In recognition of this, the U.S. National Science Foundation and National Oceanic and Atmospheric Administration galvanized a community effort (the Chemical Oceanography MEeting: A BOttom-up Approach to Research Directions, or COME ABOARD) to synthesize bottom-up perspectives on selected areas of research in Chemical Oceanography. Representing only a small subset of the community, COME ABOARD participants did not attempt to identify targeted research directions for the field. Instead, we focused on how best to foster diverse research in Chemical Oceanography, placing emphasis on the following themes: strengthening our core chemical skillset; expanding our tools through collaboration with chemists, engineers, and computer scientists; considering new roles for large programs; enhancing interface research through interdisciplinary collaboration; and expanding ocean literacy by engaging with the public. For each theme, COME ABOARD participants reflected on the present state of Chemical Oceanography, where the community hopes to go and why, and actionable pathways to get there. A unifying concept among the discussions was that dissimilar funding structures and metrics of success may be required to accommodate the various levels of readiness and stages of knowledge development found throughout our community. In addition to the science, participants of the concurrent Dissertations Symposium in Chemical Oceanography (DISCO) XXV, a meeting of recent and forthcoming Ph.D. graduates in Chemical Oceanography, provided perspectives on how our field could show leadership in addressing long-standing diversity and early-career challenges that are pervasive throughout science. Here we summarize the COME ABOARD Meeting discussions, providing a synthesis of reflections and perspectives on the

  8. The association between the incidence of postmenopausal breast cancer and concentrations at street-level of nitrogen dioxide and ultrafine particles.

    Science.gov (United States)

    Goldberg, Mark S; Labrèche, France; Weichenthal, Scott; Lavigne, Eric; Valois, Marie-France; Hatzopoulou, Marianne; Van Ryswyk, Keith; Shekarrizfard, Maryam; Villeneuve, Paul J; Crouse, Daniel; Parent, Marie-Élise

    2017-10-01

    There is scant information as to whether traffic-related air pollution is associated with the incidence of breast cancer. Nitrogen dioxide (NO 2 ) and ultrafine particles (UFPs, variations in traffic-related air pollution and may also be associated with incidence. We conducted a population-based, case-control study of street-level concentrations of NO 2 and UFPs and incident postmenopausal breast cancer in Montreal, Canada. Incident cases were identified between 2008 and 2011 from all but one hospital that treated breast cancer in the Montreal area. Population controls were identified from provincial electoral lists of Montreal residents and frequency-matched to cases using 5-year age groups. Concentrations of NO 2 and UFPs were estimated using two separate land-use regression models. Exposures were assigned to residential locations at the time of recruitment, and we identified residential histories of women who had lived in these residences for 10 years or more. Odds ratios (OR) and 95% confidence intervals (CI) were estimated using logistic regression models adjusting for individual-level and ecological covariates. We assessed the functional form of NO 2 and UFP exposures using natural cubic splines. We found that the functional form of the response functions between incident postmenopausal breast cancer and concentrations of NO 2 and UFPs were consistent with linearity. For NO 2 , we found increasing risks of breast cancer for all subjects combined and stronger associations when analyses were restricted to those women who had lived at their current address for 10 years or more. Specifically, the OR, adjusted for personal covariates, per increase in the interquartile range (IQR=3.75 ppb) of NO 2 was 1.08 (95%CI: 0.92-1.27). For women living in their homes for 10 years or more, the adjusted OR was 1.17 (95%CI: 0.93-1.46; IQR=3.84 ppb); for those not living at that home 10 years before the study, it was 0.93 (95%CI: 0.64, 1.36; IQR=3.65 ppb). For UFPs, the ORs were

  9. Lunar particle shadows and boundary layer experiment: plasma and energetic particles on the Apollo 15 and 16 subsatellites. Final report

    International Nuclear Information System (INIS)

    Anderson, K.A.; Chase, L.M.; Lin, R.P.; McCoy, J.E.; McGuire, R.E.

    1974-01-01

    The lunar particle shadows and boundary layer experiments aboard the Apollo 15 and 16 subsatellites and scientific reduction and analysis of the data to date are discussed with emphasis on four major topics: solar particles; interplanetary particle phenomena; lunar interactions; and topology and dynamics of the magnetosphere at lunar orbit. The studies of solar and interplanetary particles concentrated on the low energy region which was essentially unexplored, and the studies of lunar interaction pointed up the transition from single particle to plasma characteristics. The analysis concentrated on the electron angular distributions as highly sensitive indicators of localized magnetization of the lunar surface. Magnetosphere experiments provided the first electric field measurements in the distant magnetotail, as well as comprehensive low energy particle measurements at lunar distance

  10. Particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.

    1993-09-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics.

  11. Particle therapy

    International Nuclear Information System (INIS)

    Raju, M.R.

    1993-01-01

    Particle therapy has a long history. The experimentation with particles for their therapeutic application got started soon after they were produced in the laboratory. Physicists played a major role in proposing the potential applications in radiotherapy as well as in the development of particle therapy. A brief review of the current status of particle radiotherapy with some historical perspective is presented and specific contributions made by physicists will be pointed out wherever appropriate. The rationale of using particles in cancer treatment is to reduce the treatment volume to the target volume by using precise dose distributions in three dimensions by using particles such as protons and to improve the differential effects on tumors compared to normal tissues by using high-LET radiations such as neutrons. Pions and heavy ions combine the above two characteristics

  12. Particle cosmology

    CERN Multimedia

    CERN. Geneva

    2007-01-01

    The understanding of the Universe at the largest and smallest scales traditionally has been the subject of cosmology and particle physics, respectively. Studying the evolution of the Universe connects today's large scales with the tiny scales in the very early Universe and provides the link between the physics of particles and of the cosmos. This series of five lectures aims at a modern and critical presentation of the basic ideas, methods, models and observations in today's particle cosmology.

  13. Effects of feeding level and NDF content of grass-clover silages on chewing activity, fecal particle size and NDF digestibility in dairy heifers

    DEFF Research Database (Denmark)

    Schulze, Anne-Katrine Skovsted; Weisbjerg, Martin Riis; Nørgaard, Peder

    2014-01-01

    intake (PRumination time per kg DM intake (Pcontents (Prumination with greater...... NDF content (Prumination time increased with greater NDF content (Pcontent (P...The objective of this study was to assess effects of feed intake and NDF content of highly digestible grass-clover silage on chewing behavior, fecal particle size distribution and apparent digestibility in restrictively fed heifers. Four grass-clover silages (Lolium perenne, Trifolium pratense...

  14. Microgravity Science Glovebox (MSG), Space Science's Past, Present and Future Aboard the International Space Station (ISS)

    Science.gov (United States)

    Spivey, Reggie; Spearing, Scott; Jordan, Lee

    2012-01-01

    The Microgravity Science Glovebox (MSG) is a double rack facility aboard the International Space Station (ISS), which accommodates science and technology investigations in a "workbench' type environment. The MSG has been operating on the ISS since July 2002 and is currently located in the US Laboratory Module. In fact, the MSG has been used for over 10,000 hours of scientific payload operations and plans to continue for the life of ISS. The facility has an enclosed working volume that is held at a negative pressure with respect to the crew living area. This allows the facility to provide two levels of containment for small parts, particulates, fluids, and gases. This containment approach protects the crew from possible hazardous operations that take place inside the MSG work volume and allows researchers a controlled pristine environment for their needs. Research investigations operating inside the MSG are provided a large 255 liter enclosed work space, 1000 watts of dc power via a versatile supply interface (120, 28, + 12, and 5 Vdc), 1000 watts of cooling capability, video and data recording and real time downlink, ground commanding capabilities, access to ISS Vacuum Exhaust and Vacuum Resource Systems, and gaseous nitrogen supply. These capabilities make the MSG one of the most utilized facilities on ISS. MSG investigations have involved research in cryogenic fluid management, fluid physics, spacecraft fire safety, materials science, combustion, and plant growth technologies. Modifications to the MSG facility are currently under way to expand the capabilities and provide for investigations involving Life Science and Biological research. In addition, the MSG video system is being replaced with a state-of-the-art, digital video system with high definition/high speed capabilities, and with near real-time downlink capabilities. This paper will provide an overview of the MSG facility, a synopsis of the research that has already been accomplished in the MSG, and an

  15. Particle accelerator

    International Nuclear Information System (INIS)

    Ress, R.I.

    1976-01-01

    Charged particles are entrained in a predetermined direction, independent of their polarity, in a circular orbit by a magnetic field rotating at high speed about an axis in a closed cylindrical or toroidal vessel. The field may be generated by a cylindrical laser structure, whose beam is polygonally reflected from the walls of an excited cavity centered on the axis, or by high-frequency energization of a set of electromagnets perpendicular to the axis. In the latter case, a separate magnetostatic axial field limits the orbital radius of the particles. These rotating and stationary magnetic fields may be generated centrally or by individual magnets peripherally spaced along its circular orbit. Chemical or nuclear reactions can be induced by collisions between the orbiting particles and an injected reactant, or by diverting high-speed particles from one doughnut into the path of counterrotating particles in an adjoining doughnut

  16. All Aboard the "Titanic": Character Journals Are Just the Tip of the Iceberg.

    Science.gov (United States)

    Mercurio, Mia Lynn

    1999-01-01

    Describes how a 7th-grade reading class used character journals to explore the sailing and the sinking of the "Titanic." Describes how the students took ownership of their research and enjoyed reading and writing about actual events as they became a passenger or crew member aboard the "Titanic," explored the ship, experienced…

  17. 78 FR 14952 - Earth Stations Aboard Aircraft Communicating with Fixed-Satellite Service Geostationary-Orbit...

    Science.gov (United States)

    2013-03-08

    ... FEDERAL COMMUNICATIONS COMMISSION 47 CFR Part 2 [IB Docket No. 12-376; FCC 12-161] Earth Stations... (NPRM) seeks comment on a proposal to elevate the allocation status of Earth Stations Aboard Aircraft... with GSO space stations of the FSS on a primary basis in the 11.7-12.2 GHz band (space-to-Earth), on an...

  18. Characterization of the particle radiation environment at three potential landing sites on Mars using ESA’s MEREM models

    Science.gov (United States)

    McKenna-Lawlor, S.; Gonçalves, P.; Keating, A.; Morgado, B.; Heynderickx, D.; Nieminen, P.; Santin, G.; Truscott, P.; Lei, F.; Foing, B.; Balaz, J.

    2012-03-01

    The ‘Mars Energetic Radiation Environment Models’ (dMEREM and eMEREM) recently developed for the European Space Agency are herein used to estimate, for the first time, background Galactic Cosmic Ray (GCR) radiation and flare related solar energetic particle (SEP) events at three candidate martian landing sites under conditions where particle arrival occurred at solar minimum (December, 2006) and solar maximum (April, 2002) during Solar Cycle 23. The three landing sites were selected on the basis that they are characterized by significantly different hydrological conditions and soil compositions. Energetic particle data sets recorded on orbit at Mars at the relevant times were incomplete because of gaps in the measurements due to operational constraints. Thus, in the present study, comprehensive near-Earth particle measurements made aboard the GOES spacecraft were used as proxies to estimate the overall particle doses at each perspective landing site, assuming in each case that the fluxes fell off as 1/r2 (where r is the helio-radial distance) and that good magnetic connectivity always prevailed. The results indicate that the particle radiation environment on Mars can vary according to the epoch concerned and the landing site selected. Particle estimations obtained using MEREM are in reasonable agreement, given the inherent differences between the models, with the related NASA Heavy Ion-Nucleon Transport Code for Space Radiation/HZETRN. Both sets of results indicated that, for short (30 days) stays, the atmosphere of Mars, in the cases of the SEPs studied and the then prevailing background galactic cosmic radiation, provided sufficient shielding at the planetary surface to maintain annual skin and blood forming organ/BFO dose levels below currently accepted ionizing radiation exposure limits. The threat of occurrence of a hard spectrum SEP during Cruise-Phase transfers to/from Mars over 400 days, combined with the associated cumulative effect of prolonged GCR

  19. Stability of Dosage Forms in the Pharmaceutical Payload Aboard Space Missions

    Science.gov (United States)

    Du, Brian J.; Daniels, Vernie; Boyd, Jason L.; Crady, Camille; Satterfield, Rick; Younker, Diane R.; Putcha, Lakshmi

    2009-01-01

    Efficacious pharmaceuticals with adequate shelf lives are essential for successful space medical operations. Stability of pharmaceuticals, therefore, is of paramount importance for assuring the health and wellness of astronauts on future space exploration missions. Unique physical and environmental factors of space missions may contribute to the instability of pharmaceuticals, e.g., radiation, humidity and temperature variations. Degradation of pharmaceutical formulations can result in inadequate efficacy and/or untoward toxic effects, which could compromise astronaut safety and health. Methods: Four identical pharmaceutical payload kits containing 31 medications in different dosage forms (liquid, tablet, capsule, ointment and suppository) were transported to the International Space Station aboard the Space Shuttle (STS-121). One of the 4 kits was stored on the Shuttle and the other 3 were stored on the International Space Station (ISS) for return to Earth at 6-month interval aboard a pre-designated Shuttle flight for each kit. The kit stored on the Shuttle was returned to Earth aboard STS-121 and 2 kits from ISS were returned on STS 117 and STS-122. Results: Analysis of standard physical and chemical parameters of degradation was completed for pharmaceuticals returned by STS-121 after14 days, STS - 117 after11 months and STS 122 after 19 months storage aboard ISS. Analysis of all flight samples along with ground-based matching controls was completed and results were compiled. Conclusion: Evaluation of results from the shuttle (1) and ISS increments (2) indicate that the number of formulations degraded in space increased with duration of storage in space and was higher in space compared to their ground-based counterparts. Rate of degradation for some of the formulations tested was faster in space than on Earth. Additionally, some of the formulations included in the medical kits were unstable, more so in space than on the ground. These results indicate that the

  20. The amino-terminus of the hepatitis C virus (HCV p7 viroporin and its cleavage from glycoprotein E2-p7 precursor determine specific infectivity and secretion levels of HCV particle types.

    Directory of Open Access Journals (Sweden)

    Solène Denolly

    2017-12-01

    Full Text Available Viroporins are small transmembrane proteins with ion channel activities modulating properties of intracellular membranes that have diverse proviral functions. Hepatitis C virus (HCV encodes a viroporin, p7, acting during assembly, envelopment and secretion of viral particles (VP. HCV p7 is released from the viral polyprotein through cleavage at E2-p7 and p7-NS2 junctions by signal peptidase, but also exists as an E2p7 precursor, of poorly defined properties. Here, we found that ectopic p7 expression in HCVcc-infected cells reduced secretion of particle-associated E2 glycoproteins. Using biochemical assays, we show that p7 dose-dependently slows down the ER-to-Golgi traffic, leading to intracellular retention of E2, which suggested that timely E2p7 cleavage and p7 liberation are critical events to control E2 levels. By studying HCV mutants with accelerated E2p7 processing, we demonstrate that E2p7 cleavage controls E2 intracellular expression and secretion levels of nucleocapsid-free subviral particles and infectious virions. In addition, our imaging data reveal that, following p7 liberation, the amino-terminus of p7 is exposed towards the cytosol and coordinates the encounter between NS5A and NS2-based assembly sites loaded with E1E2 glycoproteins, which subsequently leads to nucleocapsid envelopment. We identify punctual mutants at p7 membrane interface that, by abrogating NS2/NS5A interaction, are defective for transmission of infectivity owing to decreased secretion of core and RNA and to increased secretion of non/partially-enveloped particles. Altogether, our results indicate that the retarded E2p7 precursor cleavage is essential to regulate the intracellular and secreted levels of E2 through p7-mediated modulation of the cell secretory pathway and to unmask critical novel assembly functions located at p7 amino-terminus.

  1. Plasma antioxidant capacity, sexual and thyroid hormones levels, sperm quantity and quality parameters in stressed male rats received nano-particle of selenium

    Directory of Open Access Journals (Sweden)

    M Rezaeian-Tabrizi

    2017-01-01

    Full Text Available Objective: To evaluate the effects of nano-particle of selenium (nSe on plasma antioxidant capacity, sexual and thyroid hormones and spermatogenesis in male rats exposed to oxidative stress.Methods: Forty rats were randomly divided into four treatments with ten replicates. Treatment groups were: C, the control group received normal saline as gavage and injection (i.p.; OS, received tert-butyl hydroperoxide (0.2 mmol/kg body weight for inducing oxidative stress; nSe, received nSe (0.3 mg/kg body weight as gavage, and OS+nSe, received tert-butyl hydroperoxide and nSe. All groups were treated for 28 d and administrations were done each 48 h.Results: Oxidative stress decreased and gavage of nSe to stressed rats increased the antioxidant capacity and activities (P0.05 between rats exposed to oxidative stress and those in the control group for sperm quantity and quality. Gavage of nSe to stressed rats had no effect (P>0.05 on the sperm parameters, except increased viability and progressive percentages.Conclusions: Nano-particle of Selenium administration in stressed rats could ameliorate the negative effects of oxidative stress on the antioxidant capacity and activities, but not on the quantity and quality parameters of sperm.

  2. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen

    1992-01-01

    We shall discuss the principles of the main techniques applied to particle detection (including front-end electronics), the construction and performance of some of the devices presently in operation and a few ideas on future developments.

  3. Auroral particles

    International Nuclear Information System (INIS)

    Evans, D.S.

    1987-01-01

    The problems concerning the aurora posed prior to the war are now either solved in principle or were restated in a more fundamental form. The pre-war hypothesis concerning the nature of the auroral particles and their energies was fully confirmed, with the exception that helium and oxygen ions were identified as participating in the auroral particle precipitation in addition to the protons. The nature of the near-Earth energization processes affecting auroral particles was clarified. Charged particle trajectories in various electric field geometries were modeled. The physical problems have now moved from determining the nature and geometry of the electric fields, which accelerate charged particles near the Earth, to accounting for the existence of these electric fields as a natural consequence of the solar wind's interaction with Earth. Ultimately the reward in continuing the work in auroral and magnetospheric particle dynamics will be a deeper understanding of the subtleties of classical electricity and magnetism as applied to situations not blessed with well-defined and invariant geometries

  4. Elementary particles and particle interactions

    International Nuclear Information System (INIS)

    Bethge, K.; Schroeder, U.E.

    1986-01-01

    This book is a textbook for an introductory course of elementary particle physics. After a general introduction the symmetry principles governing the interactions of elementary particles are discussed. Then the phenomenology of the electroweak and strong interactions are described together with a short introduction to the Weinberg-Salam theory respectively to quantum chromodynamics. Finally a short outlook is given to grand unification with special regards to SU(5) and cosmology in the framework of the current understanding of the fundamental principles of nature. In the appendix is a table of particle properties and physical constants. (HSI) [de

  5. Interferometry for the LISA technology package (LTP) aboard SMART-2

    International Nuclear Information System (INIS)

    Heinzel, G; Braxmaier, C; Schilling, R; Ruediger, A; Robertson, D; Plate, M te; Wand, V; Arai, K; Johann, U; Danzmann, K

    2003-01-01

    The interferometer of the LISA technology package (LTP) on SMART-2 is needed to verify the performance of the gravitational sensors by monitoring the distance between two test masses with a noise level of 10 pm Hz -1/2 between 3 mHz and 30 mHz. It must continuously track the motion of the test mass distance while that distance changes by many μm with a speed of up to 20 μm s -1 , without losing track of the sign of the motion and without exerting any influence on the test masses that might lead to a motion above that level. As a result of a detailed comparison study, a heterodyne Mach-Zehnder interferometer was selected as the baseline for the SMART-2 mission. Its design and expected performance are described in this paper

  6. Modern particle physics

    CERN Document Server

    AUTHOR|(CDS)2079874

    2013-01-01

    Unique in its coverage of all aspects of modern particle physics, this textbook provides a clear connection between the theory and recent experimental results, including the discovery of the Higgs boson at CERN. It provides a comprehensive and self-contained description of the Standard Model of particle physics suitable for upper-level undergraduate students and graduate students studying experimental particle physics. Physical theory is introduced in a straightforward manner with full mathematical derivations throughout. Fully-worked examples enable students to link the mathematical theory to results from modern particle physics experiments. End-of-chapter exercises, graded by difficulty, provide students with a deeper understanding of the subject. Online resources available at www.cambridge.org/MPP feature password-protected fully-worked solutions to problems for instructors, numerical solutions and hints to the problems for students and PowerPoint slides and JPEGs of figures from the book

  7. Neutron production in a spherical phantom aboard ISS

    International Nuclear Information System (INIS)

    Tasbaz, A.; Machrafi, R.

    2012-01-01

    As part of an ongoing research program on radiation monitoring on International Space Station (ISS) that was established to analyze the radiation exposure levels onboard the ISS using different radiation instruments and a spherical phantom to simulate human body. Monte Carlo transport code was used to simulate the interaction of high energy protons and neutrons with the spherical phantom currently onboard ISS. The phantom has been exposed to individual proton energies and to a spectrum of neutrons. The internal to external neutron flux ratio was calculated and compared to the experimental data, recently, measured on the ISS. (author)

  8. Particle detectors

    CERN Document Server

    Hilke, Hans Jürgen; Joram, Christian; CERN. Geneva

    1991-01-01

    Lecture 5: Detector characteristics: ALEPH Experiment cut through the devices and events - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operartion and a few ideas on the future performance. Lecture 4-pt. b Following the Scintillators. Lecture 4-pt. a : Scintillators - Used for: -Timing (TOF, Trigger) - Energy Measurement (Calorimeters) - Tracking (Fibres) Basic scintillation processes- Inorganic Scintillators - Organic Scintil - Discuss the principles of the main techniques applied to particle detection ( including front-end electronics), the construction and performance of some of the devices presently in operation and a fiew ideas on future developpement session 3 - part. b Following Calorimeters lecture 3-pt. a Calorimeters - determine energy E by total absorption of charged or neutral particles - fraction of E is transformed into measurable quantities - try to acheive sig...

  9. Stable particles

    International Nuclear Information System (INIS)

    Samios, N.P.

    1993-01-01

    I have been asked to review the subject of stable particles, essentially the particles that eventually comprised the meson and baryon octets. with a few more additions -- with an emphasis on the contributions made by experiments utilizing the bubble chamber technique. In this activity, much work had been done by the photographic emulsion technique and cloud chambers-exposed to cosmic rays as well as accelerator based beams. In fact, many if not most of the stable particles were found by these latter two techniques, however, the forte of the bubble chamber (coupled with the newer and more powerful accelerators) was to verify, and reinforce with large statistics, the existence of these states, to find some of the more difficult ones, mainly neutrals and further to elucidate their properties, i.e., spin, parity, lifetimes, decay parameters, etc

  10. Particle physics

    CERN Document Server

    Martin, Brian R

    2017-01-01

    An accessible and carefully structured introduction to Particle Physics, including important coverage of the Higgs Boson and recent progress in neutrino physics. Fourth edition of this successful title in the Manchester Physics series. Includes information on recent key discoveries including : An account of the discovery of exotic hadrons, beyond the simple quark model; Expanded treatments of neutrino physics and CP violation in B-decays; An updated account of ‘physics beyond the standard model’, including the interaction of particle physics with cosmology; Additional problems in all chapters, with solutions to selected problems available on the book’s website; Advanced material appears in optional starred sections.

  11. Swimming classroom. Environmental education aboard a solar powered boat; Schwimmendes Klassenzimmer. Umweltbildungsangebote an Bord einer Solarfaehre

    Energy Technology Data Exchange (ETDEWEB)

    Moerk, M. [Bodensee-Stiftung, Radolfzell (Germany)

    2006-07-01

    Summary: The swimming classroom is a particular environmental education programme. Since 2002 school classes are taught aboard the solar ferry Helio at the Lower Lake Constance. Schoolboys and girls as well as teachers have the opportunity to enlarge their knowledge about Lake Constance, its natural environment and the solar ferry Helio. They also get informed about photovoltaic systems, water pollution control and environment-friendly tourism in the Lake Constance region. Solar ferry is most suitable for nature and adventure pedagogy as well as experimental instruction. School classes and advanced training groups can easily carry out a comprehensive programme aboard the Helio and experience nature and solar technology cruising on the lake. Issues are - Energy/Photovoltaic - Limnology - Life in and on the water - Water pollution control - Geography/Landscape development. (orig.)

  12. Comparative study of proliferation kinetics of paramecium tetraurelia aboard a satellite and a balloon flight

    Energy Technology Data Exchange (ETDEWEB)

    Tixador, R.; Richoilley, G.; Gasset, G.; Planel, H. (Faculte de Medecine, Toulouse-Purpan (France))

    1982-05-17

    A possible effect of cosmic rays on cell proliferation was investigated in cultures of Paramecium tetraurelia during a stratospheric balloon flight, with the techniques already used for the CYTOS experiments, performed aboard the orbital station Salyut 6. The results show that the stimulating effect of space on cell proliferation, reported in the CYTOS experiments, also occurs in the balloon flight. The respective roles of cosmic rays and weightlesness in the biological responses are discussed.

  13. Comparative study of proliferation kinetics of paramecium tetraurelia aboard a satellite and a balloon flight

    International Nuclear Information System (INIS)

    Tixador, Rene; Richoilley, Gerard; Gasset, Gilbert; Planel, Hubert

    1982-01-01

    A possible effect of cosmic rays on cell proliferation was investigated in cultures of Paramecium tetraurelia during a stratospheric balloon flight, with the techniques already used for the CYTOS experiments, performed aboard the orbital station Salyut 6. The results show that the stimulating effect of space on cell proliferation, reported in the CYTOS experiments, also occurs in the balloon flight. The respective roles of cosmic rays and weightlesness in the biological responses are discussed [fr

  14. Soft X-ray Focusing Telescope Aboard AstroSat: Design, Characteristics and Performance

    DEFF Research Database (Denmark)

    Singh, K; Stewart, G.; Westergaard, Niels Jørgen Stenfeldt

    2017-01-01

    The Soft X-ray focusing Telescope (SXT), India’s first X-ray telescope based on the principle of grazing incidence, was launched aboard the AstroSat and made operational on October 26, 2015. X-rays in the energy band of 0.3–8.0 keV are focussed on to a cooled charge coupled device thus providing ...

  15. Modified ECC ozone sonde for long-duration flights aboard isopicnic drifting balloons

    Science.gov (United States)

    Gheusi, Francois; Durand, Pierre; Verdier, Nicolas; Dulac, François; Attié, Jean-Luc; Commun, Philippe; Barret, Brice; Basdevant, Claude; Clénet, Antoine; Fontaine, Alain; Jambert, Corinne; Meyerfeld, Yves; Roblou, Laurent; Tocquer, Flore

    2015-04-01

    Since few years, the French space agency CNES has developed boundary-layer pressurized balloons (BLPB) with the capability to transport scientific payloads at isopicnic level over very long distances and durations (up to several weeks in absence of navigation limits). However, the autonomy of conventional electrochemical concentration cell (ECC) ozone sondes, that are widely used for tropospheric and stratospheric soundings, is limited to few hours due to power consumption and electrolyte evaporation (owing to air bubbling in the cathode solution). In collaboration with the French research community, CNES has developed a new ozone payload suited for long duration flights aboard BLPB. The mechanical elements (Teflon pump and motor) and the electrochemical cell of conventional ECC sondes have been kept but the electronic implementation is entirely new. The main feature is the possibility of programming periodic measurement sequences -- with possible remote control during the flight. To increase the ozone sonde autonomy, a strategy has been adopted of short measurement sequences (typically 2-3 min) regularly spaced in time (e.g. every 15 min, which is usually sufficient for air quality studies). The rest of the time, the sonde is at rest (pump motor off). The response time of an ECC sonde to an ozone concentration step is below one minute. Consequently, the measurement sequence is typically composed of a one-minute spin-up period after the pump has been turned on, followed by a one- to two-minute acquisition period. All time intervals can be adjusted before and during the flight. Results of a preliminary ground-based test in spring 2012 are first presented. The sonde provided correct ozone concentrations against a reference UV analyzer every 15 minutes during 4 days. Then we illustrate results from 16 BLBP flights launched in the low troposphere over the Mediterranean during summer field campaings in 2012 and 2013 (TRAQA and ChArMEx programmes). BLPB drifting

  16. Elementary particles

    International Nuclear Information System (INIS)

    Prasad, R.

    1984-01-01

    Two previous monographs report on investigations into the extent to which a unified field theory can satisfactorily describe physical reality. The first, Unified field Theory, showed that the paths within a non-Riemannian space are governed by eigenvalue equations. The second, Fundamental Constants, show that the field tensors satisfy sets of differential equations with solutions which represent the evolution of the fields along the paths of the space. The results from the first two monographs are used in this one to make progress on the theory of elementary particles. The five chapters are as follows - Quantum mechanics, gravitation and electromagnetism are aspects of the Unified theory; the fields inside the particle; the quadratic and linear theories; the calculation of the eigenvalues and elementary particles as stable configurations of interacting fields. It is shown that it is possible to construct an internal structure theory for elementary particles. The theory lies within the framework of Einstein's programme-to identify physical reality with a specified geometrical structure. (U.K.)

  17. Pinpointing particles

    International Nuclear Information System (INIS)

    Miller, David J.

    1987-01-01

    The Conference on Position-Sensitive Detectors held at London's University College from 7-11 September highlighted the importance and the growing applications of these precision devices in many branches of science, underlining once again the high spinoff potential for techniques developed inside particle physics

  18. Particle tracking

    International Nuclear Information System (INIS)

    Mais, H.; Ripken, G.; Wrulich, A.; Schmidt, F.

    1986-02-01

    After a brief description of typical applications of particle tracking in storage rings and after a short discussion of some limitations and problems related with tracking we summarize some concepts and methods developed in the qualitative theory of dynamical systems. We show how these concepts can be applied to the proton ring HERA. (orig.)

  19. Pinpointing particles

    Energy Technology Data Exchange (ETDEWEB)

    Miller, David J.

    1987-10-15

    The Conference on Position-Sensitive Detectors held at London's University College from 7-11 September highlighted the importance and the growing applications of these precision devices in many branches of science, underlining once again the high spinoff potential for techniques developed inside particle physics.

  20. Particle Physics

    CERN Multimedia

    2005-01-01

    While biomedicine and geoscience use grids to bring together many different sub-disciplines, particle physicists use grid computing to increase computing power and storage resources, and to access and analyze vast amounts of data collected from detectors at the world's most powerful accelerators (1 page)

  1. Qualification of a Multi-Channel Infrared Laser Absorption Spectrometer for Monitoring CO, HCl, HCN, HF, and CO2 Aboard Manned Spacecraft

    Science.gov (United States)

    Briggs, Ryan M.; Frez, Clifford; Forouhar, Siamak; May, Randy D.; Meyer, Marit E.; Kulis, Michael J.; Berger, Gordon M.

    2015-01-01

    Monitoring of specific combustion products can provide early-warning detection of accidental fires aboard manned spacecraft and also identify the source and severity of combustion events. Furthermore, quantitative in situ measurements are important for gauging levels of exposure to hazardous gases, particularly on long-duration missions where analysis of returned samples becomes impractical. Absorption spectroscopy using tunable laser sources in the 2 to 5 micrometer wavelength range enables accurate, unambiguous detection of CO, HCl, HCN, HF, and CO2, which are produced in varying amounts through the heating of electrical components and packaging materials commonly used aboard spacecraft. Here, we report on calibration and testing of a five-channel laser absorption spectrometer designed to accurately monitor ambient gas-phase concentrations of these five compounds, with low-level detection limits based on the Spacecraft Maximum Allowable Concentrations. The instrument employs a two-pass absorption cell with a total optical pathlength of 50 cm and a dedicated infrared semiconductor laser source for each target gas. We present results from testing the five-channel sensor in the presence of trace concentrations of the target compounds that were introduced using both gas sources and oxidative pyrolysis (non-flaming combustion) of solid material mixtures.

  2. Welcome aboard (but don't change a thing).

    Science.gov (United States)

    McNulty, Eric

    2002-10-01

    Cheryl Hailstrom, the CEO of Lakeland Wonders, a manufacturer of high-quality wooden toys, is the first person outside the Swensen family to hold the top job. But she's not a stranger to this 94-year-old company: She'd been the COO of one of its largest customers and had worked with Lakeland to develop many best-selling products. Wally Swensen IV, the previous CEO, chose Cheryl because she knew how to generate profits and because he believed her energy and enthusiasm could take the company to the next level. Yet here she is, nearing her six-month anniversary, wondering why her expansive vision for the company isn't taking hold. She's tried to lead by example: traveling a pounding schedule to visit customers, setting aggressive project deadlines, and proposing a bonus schedule. She has a plan to reach the board's growth goals--going beyond Lakeland's core upscale market and launching into the midmarket with an exclusive toy contract with a new customer. The problem is that while Cheryl's senior managers are giving her the nod on the surface, they're all really dragging their feet. Some fear that offshore outsourcing will hurt their brand, not to mention make for tricky union negotiations. Others are balking at trying a new design firm. Is Cheryl pushing too much change too quickly? Should she bring in outsiders to speedily adopt the changes she envisions and overhaul Lakeland's corporate culture? Or should she keep trying to work with the current team? Commentators Kathleen Calcidise of Apple Retail Stores; executive coach Debra Benton; Dan Cohen, coauthor of The Heart of Change; and consultant Nina Aversano offer advice in this fictional case study.

  3. Temperature, salinity, nutrients, and meteorological data collected from 1926 to 1991 aboard multiple platforms in Caspian Sea (NODC Accession 0072200)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0072200 contains temperature, salinity, nutrients, and meteorological data collected from 1926 to 1991 aboard multiple platforms in Caspian Sea.

  4. Photocatalytic/Magnetic Composite Particles

    Science.gov (United States)

    Wu, Chang-Yu; Goswami, Yogi; Garretson, Charles; Andino, Jean; Mazyck, David

    2007-01-01

    Photocatalytic/magnetic composite particles have been invented as improved means of exploiting established methods of photocatalysis for removal of chemical and biological pollutants from air and water. The photocatalytic components of the composite particles are formulated for high levels of photocatalytic activity, while the magnetic components make it possible to control the movements of the particles through the application of magnetic fields. The combination of photocatalytic and magnetic properties can be exploited in designing improved air- and water treatment reactors.

  5. In-orbit performance of the soft X-ray imaging system aboard Hitomi (ASTRO-H)

    Science.gov (United States)

    Nakajima, Hiroshi; Maeda, Yoshitomo; Uchida, Hiroyuki; Tanaka, Takaaki; Tsunemi, Hiroshi; Hayashida, Kiyoshi; Tsuru, Takeshi G.; Dotani, Tadayasu; Nagino, Ryo; Inoue, Shota; Ozaki, Masanobu; Tomida, Hiroshi; Natsukari, Chikara; Ueda, Shutaro; Mori, Koji; Yamauchi, Makoto; Hatsukade, Isamu; Nishioka, Yusuke; Sakata, Miho; Beppu, Tatsuhiko; Honda, Daigo; Nobukawa, Masayoshi; Hiraga, Junko S.; Kohmura, Takayoshi; Murakami, Hiroshi; Nobukawa, Kumiko K.; Bamba, Aya; Doty, John P.; Iizuka, Ryo; Sato, Toshiki; Kurashima, Sho; Nakaniwa, Nozomi; Asai, Ryota; Ishida, Manadu; Mori, Hideyuki; Soong, Yang; Okajima, Takashi; Serlemitsos, Peter; Tawara, Yuzuru; Mitsuishi, Ikuyuki; Ishibashi, Kazunori; Tamura, Keisuke; Hayashi, Takayuki; Furuzawa, Akihiro; Sugita, Satoshi; Miyazawa, Takuya; Awaki, Hisamitsu; Miller, Eric D.; Yamaguchi, Hiroya

    2018-03-01

    We describe the in-orbit performance of the soft X-ray imaging system consisting of the Soft X-ray Telescope and the Soft X-ray Imager aboard Hitomi. Verification and calibration of imaging and spectroscopic performance are carried out, making the best use of the limited data of less than three weeks. Basic performance, including a large field of view of {38^' }} × {38^' }}, is verified with the first-light image of the Perseus cluster of galaxies. Amongst the small number of observed targets, the on-minus-off pulse image for the out-of-time events of the Crab pulsar enables us to measure the half-power diameter of the telescope as ˜{1 {^'.} 3}. The average energy resolution measured with the onboard calibration source events at 5.89 keV is 179 ± 3 eV in full width at half maximum. Light leak and crosstalk issues affected the effective exposure time and the effective area, respectively, because all the observations were performed before optimizing an observation schedule and the parameters for the dark-level calculation. Screening the data affected by these two issues, we measure the background level to be 5.6 × 10-6 counts s-1 arcmin-2 cm-2 in the energy band of 5-12 keV, which is seven times lower than that of the Suzaku XIS-BI.

  6. Active particles

    CERN Document Server

    Degond, Pierre; Tadmor, Eitan

    2017-01-01

    This volume collects ten surveys on the modeling, simulation, and applications of active particles using methods ranging from mathematical kinetic theory to nonequilibrium statistical mechanics. The contributing authors are leading experts working in this challenging field, and each of their chapters provides a review of the most recent results in their areas and looks ahead to future research directions. The approaches to studying active matter are presented here from many different perspectives, such as individual-based models, evolutionary games, Brownian motion, and continuum theories, as well as various combinations of these. Applications covered include biological network formation and network theory; opinion formation and social systems; control theory of sparse systems; theory and applications of mean field games; population learning; dynamics of flocking systems; vehicular traffic flow; and stochastic particles and mean field approximation. Mathematicians and other members of the scientific commu...

  7. Hot particles

    International Nuclear Information System (INIS)

    Merwin, S.E.; Moeller, M.P.

    1989-01-01

    Nuclear Regulatory Commission (NRC) licensees are required to assess the dose to skin from a hot particle contamination event at a depth of skin of7mg/cm 2 over an area of 1 cm 2 and compare the value to the current dose limit for the skin. Although the resulting number is interesting from a comparative standpoint and can be used to predict local skin reactions, comparison of the number to existing limits based on uniform exposures is inappropriate. Most incidents that can be classified as overexposures based on this interpretation of dose actually have no effect on the health of the worker. As a result, resources are expended to reduce the likelihood that an overexposure event will occur when they could be directed toward eliminating the cause of the problem or enhancing existing programs such as contamination control. Furthermore, from a risk standpoint, this practice is not ALARA because some workers receive whole body doses in order to minimize the occurrence of hot particle skin contaminations. In this paper the authors suggest an alternative approach to controlling hot particle exposures

  8. Relativistic particle in a box

    OpenAIRE

    Alberto, P.; Fiolhais, Carlos; Gil, Victor

    1996-01-01

    The problem of a relativistic spin 1/2 particle confined to a one-dimensional box is solved in a way that resembles closely the solution of the well known quantum-mechanical textbook problem of a non-relativistic particle in a box. The energy levels and probability density are computed and compared with the non-relativistic case

  9. TEACHING PHYSICS: Teaching particle physics

    Science.gov (United States)

    Hanley, Phil

    2000-09-01

    Particle physics attracts many students who hear of news from CERN or elsewhere in the media. This article examines which current A-level syllabuses include which bits of particle physics and surveys the many different types of resource available to teachers and students.

  10. The Lack of Cytotoxic Effect and Radioadaptive Response in Splenocytes of Mice Exposed to Low Level Internal β-Particle Irradiation through Tritiated Drinking Water in Vivo

    Directory of Open Access Journals (Sweden)

    Matthew Flegal

    2013-12-01

    Full Text Available Health effects of tritium, a β-emitter and a by-product of the nuclear industry, is a subject of significant controversy. This mouse in vivo study was undertaken to monitor biological effects of low level tritium exposure. Mice were exposed to tritiated drinking water (HTO at 10 KBq/L, 1 MBq/L and 20 MBq/L concentrations for one month. The treatment did not result in a significant increase of apoptosis in splenocytes. To examine if this low level tritium exposure alters radiosensitivity, the extracted splenocytes were challenged in vitro with 2 Gy γ-radiation, and apoptotic responses at 1 and 24 h were measured. No alterations in the radiosensitivity were detected in cells from mice exposed to tritium compared to sham-treated mice. In contrast, low dose γ-irradiation at 20 or 100 mGy, resulted in a significant increase in resistance to apoptotic cell death after 2 Gy irradiation; an indication of the radioadaptive response. Overall, our data suggest that low concentrations of tritium given to mice as HTO in drinking water do not exert cytotoxic effect in splenocytes, nor do they change cellular sensitivity to additional high dose γ-radiation. The latter may be considered as the lack of a radioadaptive response, typically observed after low dose γ-irradiation.

  11. High spin levels in 66Ga, 68Ga, 70Ga and 68Ge, 70Ge, 72Ge via fusion evaporation reactions induced by α-particles

    International Nuclear Information System (INIS)

    Morand, C.

    1979-01-01

    The high spin (J 70 Ga all the members (except the 3 - one) of the (πpsub(3/2), νgsub(9/2)) configuration have been identified, in addition with the (πfsub(5/2), νgsub(9/2))sub(7 - ) and (πgsub(9/2), νgsub(9/2))sub(9 + ) states. In 66 Ga and 68 Ga most of the levels with J>7 ca be described as a result of maximum coupling of a gsub(9/2) neutron with the odd Ga core. Thus the (πgsub(9/2), νgsub(9/2))sub(9 + ) states have been safely located. In the same way the even Ge, the backbending effect at the Jsup(π)=8 + state is less and less pronouced from the 68 Ge to the 72 Ge; that can be explained by the (νgsub(9/2)) 2 sub(8 + ) configuration of this state, so that the 8 + →6 + γ-transition is more and more allowed with increasing N, i.e. as the νgsub(9/2) shell acts more and more in the lower yrast levels Jsup(π)=0 + , 2 + , 4 + , 6 + configurations [fr

  12. DYN1: a 66 MHz front end analog memory chip with first level trigger capture for use in future high luminosity particle physics experiments

    International Nuclear Information System (INIS)

    Anghinolfi, F.; Aspell, P.; Bonino, R.; Campbell, D.; Campbell, M.; Clark, A.G.; Heijne, E.H.M.; Jarron, P.; Santiard, J.C.; Verweij, H.

    1994-01-01

    DYN1 is a 32 channel, 128 cell analog memory with continuous write and read access. The chip amplifies the detector signals and integrates the signal currents onto capacitors within the memory during each bunch crossing interval. Dense dynamic logic circuitry accepts multiple first level triggers, freezes the corresponding analog data and stores their addresses in an external FIFO. The triggered data can then be read out at leisure whilst simultaneously sampling and storing new triggered events. A first level trigger latency of up to 2 μs is accepted at the maximum LHC clock frequency of 66 MHz. The chip shows an overall gain of 48.2 mV/25 000 e - . The mean channel noise is 4.5 mV and the pedestal variation from cell to cell within one channel is 1.9 mV. The total dynamic range has been measured at 4.6 V giving a resolution of 11 bits (0.05%) for the memory itself. (orig.)

  13. Coulomb scatter of diamagnetic dust particles in a cusp magnetic trap under microgravity conditions

    Energy Technology Data Exchange (ETDEWEB)

    Myasnikov, M. I., E-mail: miasnikovmi@mail.ru; D’yachkov, L. G.; Petrov, O. F.; Vasiliev, M. M., E-mail: mixxy@mail.ru; Fortov, V. E. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation); Savin, S. F.; Serova, E. O. [Korolev Rocket and Space Corporation Energia, ul. Lenina 4A (Russian Federation)

    2017-02-15

    The effect of a dc electric field on strongly nonideal Coulomb systems consisting of a large number (~10{sup 4}) of charged diamagnetic dust particles in a cusp magnetic trap are carried out aboard the Russian segment of the International Space Station (ISS) within the Coulomb Crystal experiment. Graphite particles of 100–400 μm in size are used in the experiments. Coulomb scatter of a dust cluster and the formation of threadlike chains of dust particles are observed experimentally. The processes observed are simulated by the molecular dynamics (MD) method.

  14. All aboard!

    Science.gov (United States)

    Sharkey, Shirlee

    2014-01-01

    With technology and the health/wellness arena in the midst of a sea change that will revolutionize the system and allow more integration and information than ever before, this article reframes the discussion to broaden the opportunities for virtualization, enhanced information and communication and self-serve options. Considering these three consumer themes, the author explores how we can leverage current behaviours to achieve better connections with people, which will naturally lead to better uptake and help to narrow the gap between desire for and use of consumer health solutions.

  15. Particle Mechanics

    CERN Document Server

    Collinson, Chris

    1995-01-01

    * Assumes no prior knowledge* Adopts a modelling approach* Numerous tutorial problems, worked examples and exercises included* Elementary topics augmented by planetary motion and rotating framesThis text provides an invaluable introduction to mechanicsm confining attention to the motion of a particle. It begins with a full discussion of the foundations of the subject within the context of mathematical modelling before covering more advanced topics including the theory of planetary orbits and the use of rotating frames of reference. Truly introductory , the style adoped is perfect for those u

  16. 'Sea legs': sharpened Romberg test after three days on a live-aboard dive boat.

    Science.gov (United States)

    Gibbs, Clinton R; Commons, Katherine H; Brown, Lawrence H; Blake, Denise F

    2010-12-01

    The sharpened Romberg test (SRT) is commonly used by diving and hyperbaric physicians as an indicator of neurological decompression illness (DCI). People who spend a prolonged time on a boat at sea experience impairment in their balance on returning to shore, a condition known as mal de debarquement ('sea legs'). This conditioning of the vestibular system to the rocking motion of a boat at sea may impact on the utility of the SRT in assessing a diver with potential DCI after a live-aboard dive trip. To assess the impact 'sea legs' has on the SRT after three days on a live-aboard dive trip. Thirty-nine staff and passengers of a three-day, live-aboard dive trip performed a SRT before and after their journey, with assessment of potential variables, including middle ear barotrauma, alcohol consumption, sea-sickness and occult DCI. There was no statistically significant impact on SRT performance, with 100% completion pre-trip and 35 out of 36 divers (97.2%) post-trip. There were trends towards more attempts being required and time needed for successful SRT post-trip, but these were not statistically significant. There was a small, but noteworthy incidence of middle-ear barotrauma, with seven people affected pre-trip, and 13 post-trip. There was a higher incidence in student divers. Middle-ear barotrauma did not appear to have a direct impact on SRT performance. There was no significant impact on SRT performance resulting from 'sea legs' after three days at sea. Recreational divers, especially dive students, have a substantial incidence of mild middle ear barotrauma.

  17. Australian Aboriginal people and Torres Strait Islanders have an atherogenic lipid profile that is characterised by low HDL-cholesterol level and small LDL particles.

    Science.gov (United States)

    O'Neal, D N; Piers, L S; Iser, D M; Rowley, K G; Jenkins, A J; Best, J D; O'Dea, K

    2008-12-01

    To characterise lipid profiles for Australian Aboriginal people and Torres Strait Islanders. Community-based, cross-sectional surveys in 1995-1997 including: 407 female and 322 male Australian Aboriginal people and 207 female and 186 male Torres Strait Islanders over 15 years old. A comparator of 78 female (44 with diabetes) and 148 male (73 with diabetes) non-indigenous participants recruited to clinical epidemiological studies was used. Lipids were determined by standard assays and LDL diameter by gradient gel electrophoresis. Diabetes prevalence was 14.8% and 22.6% among Aboriginal people and Torres Strait Islanders, respectively. LDL size (mean [95% CI (confidence interval)]) was smaller (P<0.05) in non-diabetic Aboriginal (26.02 [25.96-26.07] nm) and Torres Strait Islander women (26.01 [25.92-26.09] nm) than in non-diabetic non-indigenous women (26.29 [26.13-26.44] nm). LDL size correlated (P<0.0005) inversely with triglyceride, WHR, and fasting insulin and positively with HDL-cholesterol. HDL-cholesterol (mean [95% CI] mmol/L) was lower (P<0.0005) in indigenous Australians than in non-indigenous subjects, independent of age, sex, diabetes, WHR, insulin, triglyceride, and LDL size: Aboriginal (non-diabetic women, 0.86 [0.84-0.88]; diabetic women, 0.76 [0.72-0.80]; non-diabetic men, 0.79 [0.76-0.81]; diabetic men, 0.76 [0.71-0.82]); Torres Strait Islander (non-diabetic women, 1.00 [0.95-1.04]; diabetic women, 0.89 [0.83-0.96]; non-diabetic men, 1.00 [0.95-1.04]; diabetic men, 0.87 [0.79-0.96]); non-indigenous (non-diabetic women, 1.49 [1.33-1.67]; diabetic women, 1.12 [1.03-1.21]; non-diabetic men, 1.18 [1.11-1.25]; diabetic men, 1.05 [0.98-1.12]). Indigenous Australians have a dyslipidaemia which includes small LDL and very low HDL-cholesterol levels. The dyslipidaemia was equally severe in both genders. Strategies aimed at increasing HDL-cholesterol and LDL size may reduce high CVD risk for indigenous populations.

  18. Mechanical and thermal design of an experiment aboard the space shuttle: the Spacelab spectrometer

    International Nuclear Information System (INIS)

    Besson, J.

    1985-01-01

    The spectrometer designed by ONERA and IASB (Belgium Space Aeronomy Institute) to measure atmospheric trace constituents was flown aboard Spacelab 1 during the 9 th mission of the American Space Shuttle from November 28 to December 8, 1983. After a brief summary of the history of the project related to Spacelab, the mechanical and thermal design of the spectrometer is described. Some methods, calculations and characteristic tests are detailed as examples. The behaviour of the experiment during the mission and the results of the post-flight tests are shortly analyzed in order to prepare the qualification for a reflight [fr

  19. Sex Differences in Health Care Requirements Aboard U.S. Navy Ships

    Science.gov (United States)

    1990-03-20

    asymptomatic in females, and yet may lead to serious complications, requires more sensitive laboratory and test capabilities than currently exist aboard...DISEASES OF THE DIGESTIVE SYSTEM (520-579) 18.0 28.1 14.7 1.92 522 Diseases of pulp or periapical tissues .08 .00 .11 -- 523 Gingival or periodontal ...ORGANIZATION 6b OFFICE SYMBOL 7a. NAME OF MONITORING ORGANIZATiON Naval Health Research Center (if apicable ) Chief 40 Bureau of Medicine and Surgery 6c ADDRESS

  20. SEL monitoring of the earth's energetic particle radiation environment

    International Nuclear Information System (INIS)

    Sauer, H.H.

    1989-01-01

    The Space Environment Laboratory (SEL) of the National Oceanic and Atmospheric Administration (NOAA) maintains instruments on board the GOES series of geostationary satellites, and aboard the NOAA/TIROS series of low-altitude, polar-orbiting satellites, which provide monitoring of the energetic particle radiation environment as well as monitoring the geostationary magnetic field and the solar x-ray flux. The data are used by the SEL Space Environment Services Center (SESC) to help provide real-time monitoring and forecasting of the state of the near earth environment and its disturbances, and to maintain a source of reliable information to research and operational activities of a variety of users

  1. Solar Energetic Particle Events at the Rise Phase of the 23rd Solar ...

    Indian Academy of Sciences (India)

    tribpo

    Abstract. The experiment with 10K-80 aboard the INTER-BALL-2. (which detects protons with energies >7, 27-41, 41-58, 58-88, 88-180 and 180-300 MeV) registered six events of the solar energetic particle. (SEP) increase. These events are during the initial rise phase of the 23rd solar activity cycle. Solar flares with the ...

  2. Fermilab | Particle Physics Division

    Science.gov (United States)

    Diversity Education Safety Sustainability and Environment Contact Science Science Particle Physics Neutrinos Scientific Computing Research & Development Key Discoveries Benefits of Particle Physics Particle Superconducting Test Accelerator LHC and Future Accelerators Accelerators for Science and Society Particle Physics

  3. Investigation of Mycobacterium tuberculosis transmission aboard the U.S.S. Ronald Reagan, 2006.

    Science.gov (United States)

    Buff, Ann M; Deshpande, Swati J; Harrington, Theresa A; Wofford, Taylor S; O'Hara, Timothy W; Carrigan, Kenichi; Martin, Nicholas J; McDowell, Jackie C; Ijaz, Kashef; Jensen, Paul A; Lambert, Lauren A; Moore, Marisa; Oeltmann, John E

    2008-06-01

    Pulmonary tuberculosis (TB) was diagnosed in a sailor aboard the U.S.S. Ronald Reagan; an investigation was conducted to determine a screening strategy for 1,172 civilian passengers who were aboard during a temporary guest rider program. Sailors were screened for latent TB infection (LTBI) and TB disease. A case-control study was conducted among sailors to determine factors associated with new LTBI. No secondary TB disease was identified; 13% of close contacts had new LTBI. Factors associated with new LTBI among sailors were having been born outside the United States (adjusted odds ratio = 2.80; 95% confidence interval, 1.55--5.07) and being a carrier air wing member (adjusted odds ratio = 2.89; 95% confidence interval, 1.83--4.58). Among 38 civilian passengers berthed near the patient, 1 (3%) had LTBI. The investigation results indicated that Mycobacterium tuberculosis transmission was minimal and eliminated unnecessary TB screening for 1,134 civilians which saved public health resources.

  4. Allergic reactions to peanuts, tree nuts, and seeds aboard commercial airliners.

    Science.gov (United States)

    Comstock, Sarah S; DeMera, Rich; Vega, Laura C; Boren, Eric J; Deane, Sean; Haapanen, Lori A D; Teuber, Suzanne S

    2008-07-01

    Minimal data exist on the prevalence and characteristics of in-flight reactions to foods. To characterize reactions to foods experienced by passengers aboard commercial airplanes and to examine information about flying with a food allergy available from airlines. Telephone questionnaires were administered to individuals in a peanut, tree nut, and seed allergy database who self-reported reactions aboard aircraft. Airlines were contacted to obtain information on food allergy policies. Forty-one of 471 individuals reported allergic reactions to food while on airplanes, including 4 reporting more than 1 reaction. Peanuts accounted for most of the reactions. Twenty-one individuals (51%) treated their reactions during flight. Only 12 individuals (29%) reported the reaction to a flight attendant. Six individuals went to an emergency department after landing, including 1 after a flight diversion. Airline personnel were notified of only 3 of these severe reactions. Comparison of information given to 3 different investigators by airline customer service representatives showed that inconsistencies regarding important information occurred, such as whether the airline regularly serves peanuts. In this group of mainly adults with severe nut/seed allergy, approximately 9% reported experiencing an allergic reaction to food while on board an airplane. Some reactions were serious and potentially life-threatening. Individuals commonly did not inform airline personnel about their experiences. In addition, the quality of information about flying with food allergies available from customer service departments is highly variable and, in some cases, incomplete or inaccurate.

  5. First results from the GPS atmosphere sounding experiment TOR aboard the TerraSAR-X satellite

    Directory of Open Access Journals (Sweden)

    G. Beyerle

    2011-07-01

    Full Text Available GPS radio occultation events observed between 24 July and 17 November 2008 by the IGOR occultation receiver aboard the TerraSAR-X satellite are processed and analyzed. The comparison of 15 327 refractivity profiles with collocated ECMWF data yield a mean bias between zero and −0.30 % at altitudes between 5 and 30 km. Standard deviations decrease from about 1.4 % at 5 km to about 0.6 % at 10 km altitude, however, increase significantly in the upper stratosphere. At low latitudes mean biases and standard deviations are larger, in particular in the lower troposphere. The results are consistent with 15 159 refractivity observations collected during the same time period by the BlackJack receiver aboard GRACE-A and processed by GFZ's operational processing system. The main difference between the two occultation instruments is the implementation of open-loop signal tracking in the IGOR (TerraSAR-X receiver which improves the tropospheric penetration depth in terms of ray height by about 2 km compared to the conventional closed-loop data acquired by BlackJack (GRACE-A.

  6. Single Particle Entropy in Heated Nuclei

    International Nuclear Information System (INIS)

    Guttormsen, M.; Chankova, R.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Syed, N. U. H.; Agvaanluvsan, U.; Schiller, A.; Voinov, A.

    2006-01-01

    The thermal motion of single particles represents the largest contribution to level density (or entropy) in atomic nuclei. The concept of single particle entropy is presented and shown to be an approximate extensive (additive) quantity for mid-shell nuclei. A few applications of single particle entropy are demonstrated

  7. Nuclear energy levels and elementary particles

    International Nuclear Information System (INIS)

    de Wet, J.A.

    1982-01-01

    Considering only exchange forces, the binding energies and excited states of nuclei up to 24 Mg are predicted to within charge independence, and there is no reason why the model should not be extended to cover all of the elements. A comparison of theory with experiment shows that the energy of one exchange is 2.56 MeV. Moreover, there is an attractive well of depth 30 MeV, corresponding to the helium nucleus. before exchange forces become operative. A possible explanation of the origin of mesons is also presented

  8. Occupational Safety and Health Conditions Aboard Small- and Medium-Size Fishing Vessels: Differences among Age Groups.

    Science.gov (United States)

    Zytoon, Mohamed A; Basahel, Abdulrahman M

    2017-02-24

    Although marine fishing is one of the most hazardous occupations, research on the occupational safety and health (OSH) conditions aboard marine fishing vessels is scarce. For instance, little is known about the working conditions of vulnerable groups such as young and aging fishermen. The objective of the current paper is to study the OSH conditions of young and aging fishermen compared to middle-aged fishermen in the small- and medium-size (SM) marine fishing sector. A cross-sectional study was designed, and 686 fishermen working aboard SM fishing vessels were interviewed to collect information about their safety and health. The associations of physical and psychosocial work conditions with safety and health outcomes, e.g., injuries, illnesses and job satisfaction, are presented. The results of the current study can be utilized in the design of effective accident prevention and OSH training programs for the three age groups and in the regulation of working conditions aboard fishing vessels.

  9. Prospects of particle physics

    International Nuclear Information System (INIS)

    Meyer-Berkhout, U.

    1986-01-01

    Remarkable progress has been achieved in the last two decades in the field of particle physics. From the insight gained by the many experimental data, physicists derive a framework picture of matter on the sub-nuclear level, consisting of fundamental components which interact with each other in a defined and quantitatively detectable manner. The data now available allowed a quantum field theory of strong interactions to be set up for the first time, and a unified theory of electromagnetic and weak interaction. Particle physicists today take particular interest in the problem of whether the strong interaction might fit into an extended unified theory. Such a grand unified theory would have a far-reaching impact on the conceptual models both of the cosmic and sub-nuclear dimensions, and possibly lead to observable effects in domains of energy and mass which will be opened up for experiments by the new accelerator generation underway. Current activities throughout the world for constructing or projecting the new high-energy particle accelerators are outlined in the article, together with the prospects expected by particle physicists, and a look back on the history and achievements of this field of science. (orig.) [de

  10. Particle kickers

    CERN Multimedia

    Antonella Del Rosso

    2014-01-01

    These devices are designed to provide a current pulse of 5000 Amps which will in turn generate a fast magnetic pulse that steers the incoming beam into the LHC. Today, the comprehensive upgrade of the LHC injection kicker system is entering its final stages. The upgraded system will ensure the LHC can be refilled without needing to wait for the kicker magnets to cool, thus enhancing the performance of the whole accelerator.   An upgraded kicker magnet in its vacuum tank, with an upgraded beam screen. The LHC is equipped with two kicker systems installed at the injection points (near points 2 and 8, see schematic diagram) where the particle beams coming from the SPS are injected into the accelerator’s orbit. Each system comprises four magnets and four pulse generators in which the field rises to 0.12 Tesla in less than 900 nanoseconds and for a duration of approximately 8 microseconds. Although the injection kickers only pulse 12 times to fill the LHC up with beam, the LHC beam circ...

  11. Investigations of the effects of cosmic rays on Artemia cysts and tobacco seeds: results of Exobloc II experiment, flown aboard Biocosmos 1887

    Energy Technology Data Exchange (ETDEWEB)

    Gaubin, Y; Pianezzi, B; Gasset, G; Planel, H [Laboratoire de Biologie Medicale, Faculte de Medecine, Toulouse (France); Delpoux, M [Laboratoire de Biogeographie, Faculte des Sciences, Toulouse (France); Heilmann, C [Strasbourg-1 Univ., 67 (France). Centre de Recherches Nucleaires

    1990-01-01

    Artemia (Brine shrimp) cysts and tobacco seeds, dormant biological material devoid of metabolic activity, were flown aboard the Soviet Biocosmos 1887 in order to investigate the effects of cosmic rays. Artemia cysts and tobacco seeds were used in bulk or in monolayers sandwiched with track detectors. Biological and physical units were located outside and inside the spacecraft. Stacks included lead shielding in order to expose the objects to different doses of radiation. Total dosimetry was performed using thermoluminescent detectors. In spite of low levels of doses, the space flight resulted in a decrease in developmental capacity of Artemia cysts, and in a higher mutation rate in tobacco seeds. The more obvious responses occurred, in both cases, in biological objects exposed to the highest doses. These results are compared to those of previous space experiments. (author).

  12. Hard sell for particle physics?

    International Nuclear Information System (INIS)

    Brown, Julian.

    1994-01-01

    With particle physics experimental research becoming ever more expensive, the author considers whether the cost of such research is worthwhile. As costs escalated on the Superconducting Supercollider, the project has now been terminated. Particle physicists must now look for commercial imperatives to justify their work. Many of the important spin-offs from particle physics research are described in order to justify the subject's continued funding, albeit at very high levels, where funds might otherwise be directed to more mundane but very necessary causes such as health care or education. (UK)

  13. Direct Signal-to-Noise Quality Comparison between an Electronic and Conventional Stethoscope aboard the International Space Station

    Science.gov (United States)

    Marshburn, Thomas; Cole, Richard; Ebert, Doug; Bauer, Pete

    2014-01-01

    Introduction: Evaluation of heart, lung, and bowel sounds is routinely performed with the use of a stethoscope to help detect a broad range of medical conditions. Stethoscope acquired information is even more valuable in a resource limited environments such as the International Space Station (ISS) where additional testing is not available. The high ambient noise level aboard the ISS poses a specific challenge to auscultation by stethoscope. An electronic stethoscope's ambient noise-reduction, greater sound amplification, recording capabilities, and sound visualization software may be an advantage to a conventional stethoscope in this environment. Methods: A single operator rated signal-to-noise quality from a conventional stethoscope (Littman 2218BE) and an electronic stethoscope (Litmann 3200). Borborygmi, pulmonic, and cardiac sound quality was ranked with both stethoscopes. Signal-to-noise rankings were preformed on a 1 to 10 subjective scale with 1 being inaudible, 6 the expected quality in an emergency department, 8 the expected quality in a clinic, and 10 the clearest possible quality. Testing took place in the Japanese Pressurized Module (JPM), Unity (Node 2), Destiny (US Lab), Tranquility (Node 3), and the Cupola of the International Space Station. All examinations were conducted at a single point in time. Results: The electronic stethoscope's performance ranked higher than the conventional stethoscope for each body sound in all modules tested. The electronic stethoscope's sound quality was rated between 7 and 10 in all modules tested. In comparison, the traditional stethoscope's sound quality was rated between 4 and 7. The signal to noise ratio of borborygmi showed the biggest difference between stethoscopes. In the modules tested, the auscultation of borborygmi was rated between 5 and 7 by the conventional stethoscope and consistently 10 by the electronic stethoscope. Discussion: This stethoscope comparison was limited to a single operator. However, we

  14. Tunable diode laser in-situ CH4 measurements aboard the CARIBIC passenger aircraft: instrument performance assessment

    Science.gov (United States)

    Dyroff, C.; Zahn, A.; Sanati, S.; Christner, E.; Rauthe-Schöch, A.; Schuck, T. J.

    2014-03-01

    A laser spectrometer for automated monthly measurements of methane (CH4) mixing ratios aboard the CARIBIC passenger aircraft is presented. The instrument is based on a commercial Fast Greenhouse Gas Analyser (FGGA, Los Gatos Res.), which was adapted to meet the requirements imposed by unattended airborne operation. It was characterised in the laboratory with respect to instrument stability, precision, cross sensitivity to H2O, and accuracy. For airborne operation, a calibration strategy is described that utilises CH4 measurements obtained from flask samples taken during the same flights. The precision of airborne measurements is 2 ppb for 10 s averages. The accuracy at aircraft cruising altitude is 3.85 ppb. During aircraft ascent and descent, where no flask samples were obtained, instrumental drifts can be less accurately determined and the uncertainty is estimated to be 12.4 ppb. A linear humidity bias correction was applied to the CH4 measurements, which was most important in the lower troposphere. On average, the correction bias was around 6.5 ppb at an altitude of 2 km, and negligible at cruising flight level. Observations from 103 long-distance flights are presented that span a large part of the northern hemispheric upper troposphere and lowermost stratosphere (UT/LMS), with occasional crossing of the tropics on flights to southern Africa. These accurate data mark the largest UT/LMS in-situ CH4 dataset worldwide. An example of a tracer-tracer correlation study with ozone is given, highlighting the possibility for accurate cross-tropopause transport analyses.

  15. Microscale packed bed reactor for controlled hydrogen peroxide decomposition as a fuel cell oxidant aboard unmanned undersea vehicles

    Energy Technology Data Exchange (ETDEWEB)

    Lennon, E.; Ocampo, M.; Besser, R.S. [Department of Chemical Engineering and Materials Science, Stevens Institute of Technology, Castle Point on Hudson, Hoboken, NJ 07030 (United States); Burke, A.A. [Naval Undersea Warfare Center, Newport, RI 02841 (United States)

    2010-01-01

    The multiphase catalytic decomposition of hydrogen peroxide into water and oxygen is notoriously susceptible to thermal runaway (heat of reaction: -98 kJ mol{sup -1}). The high surface area to volume ratio (S/V) in a microscale packed bed (MPB) reactor (radius 0.5 mm) was investigated for reducing the risk of thermal runaway during hydrogen peroxide decomposition to oxygen intended as a fuel cell oxidant aboard an unmanned undersea vehicle (UUV). A microscale reactor channel with a S/V of {proportional_to}2 x 10{sup 3} m{sup 2} m{sup -3} simulated under convective cooling generated a significant heat rise (T rise {proportional_to} 100 K), whereas a microreactor with a higher S/V ({proportional_to}200 x 10{sup 3} m{sup 2} m{sup -3}) achieved thermal control (T rise < 10 K) over the simulated reaction zone. Although thermal management was successfully accomplished using the higher S/V, experimental conversions of hydrogen peroxide to oxygen (5-18%) measured from the outlet were lower than simulated conversions (38-63%). Simulation assumptions, such as homogeneously dispersed flow and perfect catalyst interaction among other factors, contributed to the discrepancies between the simulated and experimental degrees of peroxide conversion to oxygen. Even though thermal control of the MPB was achieved, this work indicates that mass transfer limitations are a factor in the MPB reactor during a multiphase reaction, like decomposition of hydrogen peroxide to oxygen and water, and suggests means to overcome them even on the microscale level. (author)

  16. Design progress of the solar UV-Vis-IR telescope (SUVIT) aboard SOLAR-C

    Science.gov (United States)

    Katsukawa, Y.; Ichimoto, K.; Suematsu, Y.; Hara, H.; Kano, R.; Shimizu, T.; Matsuzaki, K.

    2013-09-01

    We present a design progress of the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. SUVIT has an aperture diameter of ~1.4 m for achieving spectro-polarimetric observations with spatial and temporal resolution exceeding the Hinode Solar Optical Telescope (SOT). We have studied structural and thermal designs of the optical telescope as well as the optical interface between the telescope and the focal plane instruments. The focal plane instruments are installed into two packages, filtergraph and spectrograph packages. The spectropolarimeter is the instrument dedicated to accurate polarimetry in the three spectrum windows at 525 nm, 854 nm, and 1083 nm for observing magnetic fields at both the photospheric and chromospheric layers. We made optical design of the spectrograph accommodating the conventional slit spectrograph and the integral field unit (IFU) for two-dimensional coverage. We are running feasibility study of the IFU using fiber arrays consisting of rectangular cores.

  17. Gamma radiation measurement, through a spark chamber put aboard of a stratospheric balloon

    International Nuclear Information System (INIS)

    Santo, C.M.E.; Rao, K.R.

    1982-06-01

    For determining the diffuse component of gamma rays in the 15 to 75 Mev range arriving from near the galactic center, a digitized spark chamber was launched aboard two balloons from Resende, Brazil, on 19 November and 3 December 1975. In each flight the detector reached an altitude of 2,2 g/cm 2 . Based on these data, a diffuse gamma ray flux 6,0x10 - 5 , 2,0x10 - 5 , 4,6x10 - 6 and 1,3x10 - 6 photons (cm 2 .s.sterad.Mev) at energies of 21, 36, 52, 67 Mev respectively was obtained. These values give a power law spectrum with spectral index equal to -3,3. The dependence of this radiation with the galactic latitude and longitude in the interval -5 0 0 and 325 0 0 was also obtained. Finally, our results were compared with other experiments' results. (Author) [pt

  18. Fermilab | Science | Particle Physics

    Science.gov (United States)

    Photos and videos Latest news For the media Particle Physics Neutrinos Fermilab and the LHC Dark matter initiatives Research and development Key discoveries Benefits of particle physics Particle Accelerators society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery

  19. The application of land-based computerized spectrometers for effluent monitoring aboard nuclear powered ships. Final technical report

    International Nuclear Information System (INIS)

    Kamykowski, E.A.

    1975-12-01

    This report assesses the applicability of computer-based, Ge(Li) detector spectroscopy systems as effluent monitors aboard nuclear powered ships. A survey of the principal commercial spectrometers, in light of the expected shipboard use, indicates these systems may be employed for automatic radioisotope analysis in a seagoing environment if adequate protective measures are adopted

  20. Particle theory and cosmology

    International Nuclear Information System (INIS)

    Gaisser, T.K.; Shafi, Q.; Barr, S.M.; Seckel, D.; Rusjan, E.; Fletcher, R.S.

    1991-01-01

    This report discusses research of professor at Bartol research institute in the following general areas: particle phenomenology and non-accelerator physics; particle physics and cosmology; theories with higher symmetry; and particle astrophysics and cosmology

  1. Particle ID in LHCb

    International Nuclear Information System (INIS)

    Powell, Andrew

    2010-01-01

    Particle identification (PID) is a fundamental requirement for LHCb and is provided by CALO, MUON and RICH sub-detectors. The Calorimeters provide identification of electrons, photons and hadrons in addition to the measurement of their energies and positions. As well as being part of the LHCb trigger, the MUON system provides identification of muons to a very high level of purity, essential for many CP-sensitive measurements that have J/ψ's in their final states. Hadron identification, in particular the ability to distinguish kaons and pions, is crucial to many LHCB analyses, particularly where the final states of interest are purely hadronic. The LHCb RICH system provides this, covering a momentum range between 1 and 100 GeV/c. To maintain the integrity of the LHCb physics performance, it is essential to measure and monitor the particle identification efficiency and mis-identification fraction over time. This can be done by using specific decays, such as K-shorts, φ's, Λ's, J/ψ's and D*'s, for which pure samples can be isolated using only kinematic quantities, due to their unique decay topologies. This allows for clean samples of known particle types to be selected, which can then be used to calibrate and monitor the PID performance from data. The procedures for performing this will be presented, together with preliminary results from the 2009 and 2010 LHC runs. (author)

  2. New particles and interactions

    International Nuclear Information System (INIS)

    Gilman, F.J.; Grannis, P.D.

    1984-04-01

    The Working Group on New Particles and Interactions met as a whole at the beginning and at the end of the Workshop. However, much of what was accomplished was done in five subgroups. These were devoted to: (1) new quarks and leptons; (2) technicolor; (3) supersymmetry; (4) rare decays and CP; and (5) substructure of quarks and leptons. Other aspects of new particles, e.g., Higgs, W', Z', fell to the Electroweak Working Group to consider. The central question of this Workshop of comparing anti pp (with L = 10 32 /cm 2 -sec) with pp (with L = 10 33 /cm 2 -sec) colliders carried through to all these subgroups. In addition there were several other aspects of hadron colliders which were considered: what does an increase in √s gain in cross section and resultant sensitivity to new physics versus an increase in luminosity; will polarized beams or the use of asymmetries be essential in finding new interactions; where and at what level do rate limitations due to triggering or detection systems play a role; and how and where will the detection of particles with short, but detectable, lifetimes be important. 25 references

  3. Level densities

    International Nuclear Information System (INIS)

    Ignatyuk, A.V.

    1998-01-01

    For any applications of the statistical theory of nuclear reactions it is very important to obtain the parameters of the level density description from the reliable experimental data. The cumulative numbers of low-lying levels and the average spacings between neutron resonances are usually used as such data. The level density parameters fitted to such data are compiled in the RIPL Starter File for the tree models most frequently used in practical calculations: i) For the Gilber-Cameron model the parameters of the Beijing group, based on a rather recent compilations of the neutron resonance and low-lying level densities and included into the beijing-gc.dat file, are chosen as recommended. As alternative versions the parameters provided by other groups are given into the files: jaeri-gc.dat, bombay-gc.dat, obninsk-gc.dat. Additionally the iljinov-gc.dat, and mengoni-gc.dat files include sets of the level density parameters that take into account the damping of shell effects at high energies. ii) For the backed-shifted Fermi gas model the beijing-bs.dat file is selected as the recommended one. Alternative parameters of the Obninsk group are given in the obninsk-bs.dat file and those of Bombay in bombay-bs.dat. iii) For the generalized superfluid model the Obninsk group parameters included into the obninsk-bcs.dat file are chosen as recommended ones and the beijing-bcs.dat file is included as an alternative set of parameters. iv) For the microscopic approach to the level densities the files are: obninsk-micro.for -FORTRAN 77 source for the microscopical statistical level density code developed in Obninsk by Ignatyuk and coworkers, moller-levels.gz - Moeller single-particle level and ground state deformation data base, moller-levels.for -retrieval code for Moeller single-particle level scheme. (author)

  4. Health effects of exhaust particles

    Energy Technology Data Exchange (ETDEWEB)

    Pihlava, T.; Uuppo, M.; Niemi, S.

    2013-11-01

    , they can migrate far away from their source and they can even spread into the blood circulation and the brain. Transition metals on the surface of particles together with carcinogenic compounds found in the PM have been shown to cause cancer. Diesel ultra-fine particles are mainly elemental carbon, organic carbon and sulphuric acid. Sulphur still exists in diesel fuel in certain regions and if the amount of sulphur in the fuel is reduced, particles are reduced as well. Metallic compounds originate mainly from the lubrication oil, but also from the fuel and engine wear. In urban areas the amounts of particles are usually higher than in rural areas. Regulations for air quality in urban areas have been set to protect people living in the cities. Regulations are also becoming stricter in the field of internal combustion engines and particle numbers along with their mass are regulated in the EURO 6 standard. Diesel PM can be reduced by several means. Reformulating the fuel and lubrication oil directly influences PM emissions while different aftertreatment systems can be used to remove PM from the engine exhaust gases. With a well-optimized injection system, burning is more complete and PM emissions are also reduced. Exposure to particles can be decreased by avoiding busy roads where the level of particles is usually high, having a hobby that involves less exertion and decreasing exercise time. Outdoor activities should be reduced when PM concentration in the air is high. (orig.)

  5. Effects of aerodynamic particle interaction in turbulent non-dilute particle-laden flow

    DEFF Research Database (Denmark)

    Salewski, Mirko; Fuchs, Laszlo

    2008-01-01

    Aerodynamic four-way coupling models are necessary to handle two-phase flows with a dispersed phase in regimes in which the particles are neither dilute enough to neglect particle interaction nor dense enough to bring the mixture to equilibrium. We include an aerodynamic particle interaction model...... levels in the flow then decrease. The impact of the stochastic particle description on the four-way coupling model is shown to be relatively small. If particles are also allowed to break up according to a wave breakup model, the particles become polydisperse. An ad hoc model for handling polydisperse...

  6. Elementary Particles A New Approach

    Directory of Open Access Journals (Sweden)

    FranciscoMartnezFlores.

    2015-07-01

    Full Text Available ABSTRACT It is shown the inexistence of neutrinos to define precisely the concept of relativistics mass under this scheme to elementarys particles as electron and interactions particles like photons correspond an electromagnetic and virtual mass. Nucleons protons and neutrons have real or inertial mass for being composite particles since inertia needs structure it is provided by an interactive network originated by strong and weak forces. This mass is building up atoms and all the material world under Classical Physics and Chemistrys laws.These actual masses may be considered as electromagnetic and virtual one thanks to its charge in order to establish the high energies level needed to obtain all particles physics elementary or not which are governed by the laws of Quantum Physics. With all this one may set up amore reasonable and understandable new Standard Model which being projected into Cosmological Model can get rid of some inconsistencies and concepts difficult to be admitted.

  7. End-To-END Performance of the future MOMA intrument aboard the EXOMARS MISSION

    Science.gov (United States)

    Buch, A.; Pinnick, V. T.; Szopa, C.; Grand, N.; Danell, R.; van Amerom, F. H. W.; Freissinet, C.; Glavin, D. P.; Stalport, F.; Arevalo, R. D., Jr.; Coll, P. J.; Steininger, H.; Raulin, F.; Goesmann, F.; Mahaffy, P. R.; Brinckerhoff, W. B.

    2016-12-01

    After the SAM experiment aboard the curiosity rover, the Mars Organic Molecule Analyzer (MOMA) experiment aboard the future ExoMars mission will be the continuation of the search for the organic composition of the Mars surface with the advantage that the sample will be extracted as deep as 2 meters below the martian surface to minimize effects of radiation and oxidation on organic materials. To analyse the wide range of organic composition (volatile and non volatils compounds) of the martian soil MOMA is composed with an UV laser desorption / ionization (LDI) and a pyrolysis gas chromatography ion trap mass spectrometry (pyr-GC-ITMS). In order to analyse refractory organic compounds and chirality samples which undergo GC-ITMS analysis may be submitted to a derivatization process, consisting of the reaction of the sample components with specific reactants (MTBSTFA [1], DMF-DMA [2] or TMAH [3]). To optimize and test the performance of the GC-ITMS instrument we have performed several coupling tests campaigns between the GC, providing by the French team (LISA, LATMOS, CentraleSupelec), and the MS, providing by the US team (NASA, GSFC). Last campaign has been done with the ITU models wich is similar to the flight model and wich include the oven and the taping station providing by the German team (MPS). The results obtained demonstrate the current status of the end-to-end performance of the gas chromatography-mass spectrometry mode of operation. References:[1] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [2] Freissinet et al. (2011) J Chrom A, 1306, 59-71. [3] Geffroy-Rodier, C. et al. (2009) JAAP, 85, 454-459. Acknowledgements: Funding provided by the Mars Exploration Program (point of contact, George Tahu, NASA/HQ). MOMA is a collaboration between NASA and ESA (PI Goesmann, MPS). MOMA-GC team acknowledges support from the French Space Agency (CNES), French National Programme of Planetology (PNP), National French Council (CNRS), Pierre Simon Laplace Institute.

  8. Multi-spacecraft observations and transport simulations of solar energetic particles for the May 17th 2012 event

    Science.gov (United States)

    Battarbee, M.; Guo, J.; Dalla, S.; Wimmer-Schweingruber, R.; Swalwell, B.; Lawrence, D. J.

    2018-05-01

    Context. The injection, propagation and arrival of solar energetic particles (SEPs) during eruptive solar events is an important and current research topic of heliospheric physics. During the largest solar events, particles may have energies up to a few GeVs and sometimes even trigger ground-level enhancements (GLEs) at Earth. These large SEP events are best investigated through multi-spacecraft observations. Aims: We aim to study the first GLE-event of solar cycle 24, from 17th May 2012, using data from multiple spacecraft (SOHO, GOES, MSL, STEREO-A, STEREO-B and MESSENGER). These spacecraft are located throughout the inner heliosphere, at heliocentric distances between 0.34 and 1.5 astronomical units (au), covering nearly the whole range of heliospheric longitudes. Methods: We present and investigate sub-GeV proton time profiles for the event at several energy channels, obtained via different instruments aboard the above spacecraft. We investigated issues caused by magnetic connectivity, and present results of three-dimensional SEP propagation simulations. We gathered virtual time profiles and perform qualitative and quantitative comparisons with observations, assessed longitudinal injection and transport effects as well as peak intensities. Results: We distinguish different time profile shapes for well-connected and weakly connected observers, and find our onset time analysis to agree with this distinction. At select observers, we identify an additional low-energy component of Energetic Storm Particles (ESPs). Using well-connected observers for normalisation, our simulations are able to accurately recreate both time profile shapes and peak intensities at multiple observer locations. Conclusions: This synergetic approach combining numerical modelling with multi-spacecraft observations is crucial for understanding the propagation of SEPs within the interplanetary magnetic field. Our novel analysis provides valuable proof of the ability to simulate SEP propagation

  9. The relations of particles

    International Nuclear Information System (INIS)

    Okun, L.B.

    1991-01-01

    This book presents papers on elementary particle physics, relations between various particles, and the connections between particle physics with other branches of physics. The papers include: Contemporary status and prospects of high-energy physics; Particle physics prospects; and High energy physics

  10. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

    The book provides a comprehensive and easily accessible reference source covering all important aspects of particle adhesion and removal.  The core objective is to cover both fundamental and applied aspects of particle adhesion and removal with emphasis on recent developments.  Among the topics to be covered include: 1. Fundamentals of surface forces in particle adhesion and removal.2. Mechanisms of particle adhesion and removal.3. Experimental methods (e.g. AFM, SFA,SFM,IFM, etc.) to understand  particle-particle and particle-substrate interactions.4. Mechanics of adhesion of micro- and  n

  11. The T10 beam produces a few hits per event. In ALICE the SSD will have to cope with many hits per strip. In the three centimeters of aluminium the beam will produce many secondary particles. This increases the chance of multiple hits per strip, although not to the level in ALICE.

    CERN Multimedia

    Nooren, G.

    2004-01-01

    The T10 beam produces a few hits per event. In ALICE the SSD will have to cope with many hits per strip. In the three centimeters of aluminium the beam will produce many secondary particles. This increases the chance of multiple hits per strip, although not to the level in ALICE.

  12. Review of particle properties. Particle Data Group

    International Nuclear Information System (INIS)

    1978-04-01

    This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Rev. Mod. Phys. 48 (1976) No. 2, Part II; and Supplement, Phys. Lett. 68B (1977) 1]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available

  13. 'Hot' particles in the atmosphere (Vilnius, 1986)

    International Nuclear Information System (INIS)

    Lujanas, V.; Shpirkauskaite, N.

    1992-01-01

    After the Chernobyl accident in the atmosphere above Vilnius the alpha-and beta- 'hot' particles were discovered. The amount of particles and their size were measured by the alpha-radiography. After the exposition of nuclear plates the 'auroras' of the beta hot particles were of the size 0.37-22.2 μm. The change in time of the beta- 'hot' particles amount in the ground level air from the 25th of April to the 9th of May, 1986 was given. The amount of this particles deposited in the adult man respiratory tract was calculated. The energy of the discovered 8 'hot' alpha-particles ranged from 4.2 to 6.6 MeV. All the samples in which alpha- 'hot' particles found were taken in anticyclone conditions. (author). 1 tab., 1 ref

  14. Wetlab-2 - Quantitative PCR Tools for Spaceflight Studies of Gene Expression Aboard the International Space Station

    Science.gov (United States)

    Schonfeld, Julie E.

    2015-01-01

    Wetlab-2 is a research platform for conducting real-time quantitative gene expression analysis aboard the International Space Station. The system enables spaceflight genomic studies involving a wide variety of biospecimen types in the unique microgravity environment of space. Currently, gene expression analyses of space flown biospecimens must be conducted post flight after living cultures or frozen or chemically fixed samples are returned to Earth from the space station. Post-flight analysis is limited for several reasons. First, changes in gene expression can be transient, changing over a timescale of minutes. The delay between sampling on Earth can range from days to months, and RNA may degrade during this period of time, even in fixed or frozen samples. Second, living organisms that return to Earth may quickly re-adapt to terrestrial conditions. Third, forces exerted on samples during reentry and return to Earth may affect results. Lastly, follow up experiments designed in response to post-flight results must wait for a new flight opportunity to be tested.

  15. Studying Planarian Regeneration Aboard the International Space Station within the Student Space Flight Experimental Program

    Science.gov (United States)

    Vista SSEP Mission 11 Team; Hagstrom, Danielle; Bartee, Christine; Collins, Eva-Maria S.

    2018-05-01

    The growing possibilities of space travel are quickly moving from science fiction to reality. However, to realize the dream of long-term space travel, we must understand how these conditions affect biological and physiological processes. Planarians are master regenerators, famous for their ability to regenerate from very small parts of the original animal. Understanding how this self-repair works may inspire regenerative therapies in humans. Two studies conducted aboard the International Space Station (ISS) showed that planarian regeneration is possible in microgravity. One study reported no regenerative defects, whereas the other study reported behavioral and microbiome alterations post-space travel and found that 1 of 15 planarians regenerated a Janus head, suggesting that microgravity exposure may not be without consequences. Given the limited number of studies and specimens, further microgravity experiments are necessary to evaluate the effects of microgravity on planarian regeneration. Such studies, however, are generally difficult and expensive to conduct. We were fortunate to be sponsored by the Student Spaceflight Experiment Program (SSEP) to investigate how microgravity affects regeneration of the planarian species Dugesia japonica on the ISS. While we were unable to successfully study planarian regeneration within the experimental constraints of our SSEP Mission, we systematically analyzed the cause for the failed experiment, leading us to propose a modified protocol. This work thus opens the door for future experiments on the effects of microgravity on planarian regeneration on SSEP Missions as well as for more advanced experiments by professional researchers.

  16. The RTE inversion on FPGA aboard the solar orbiter PHI instrument

    Science.gov (United States)

    Cobos Carrascosa, J. P.; Aparicio del Moral, B.; Ramos Mas, J. L.; Balaguer, M.; López Jiménez, A. C.; del Toro Iniesta, J. C.

    2016-07-01

    In this work we propose a multiprocessor architecture to reach high performance in floating point operations by using radiation tolerant FPGA devices, and under narrow time and power constraints. This architecture is used in the PHI instrument that carries out the scientific analysis aboard the ESA's Solar Orbiter mission. The proposed architecture, in a SIMD flavor, is aimed to be an accelerator within the Data Processing Unit (it is composed by a main Leon processor and two FPGAs) for carrying out the RTE inversion on board the spacecraft using a relatively slow FPGA device - Xilinx XQR4VSX55-. The proposed architecture squeezes the FPGA resources in order to reach the computational requirements and improves the ground-based system performance based on commercial CPUs regarding time and power consumption. In this work we demonstrate the feasibility of using this FPGA devices embedded in the SO/PHI instrument. With that goal in mind, we perform tests to evaluate the scientific results and to measure the processing time and power consumption for carrying out the RTE inversion.

  17. Studying Planarian Regeneration Aboard the International Space Station Within the Student Space Flight Experimental Program

    Directory of Open Access Journals (Sweden)

    Vista SSEP Mission 11 Team

    2018-05-01

    Full Text Available The growing possibilities of space travel are quickly moving from science fiction to reality. However, to realize the dream of long-term space travel, we must understand how these conditions affect biological and physiological processes. Planarians are master regenerators, famous for their ability to regenerate from very small parts of the original animal. Understanding how this self-repair works may inspire regenerative therapies in humans. Two studies conducted aboard the International Space Station (ISS showed that planarian regeneration is possible in microgravity. One study reported no regenerative defects, whereas the other study reported behavioral and microbiome alterations post-space travel and found that 1 of 15 planarians regenerated a Janus head, suggesting that microgravity exposure may not be without consequences. Given the limited number of studies and specimens, further microgravity experiments are necessary to evaluate the effects of microgravity on planarian regeneration. Such studies, however, are generally difficult and expensive to conduct. We were fortunate to be sponsored by the Student Spaceflight Experiment Program (SSEP to investigate how microgravity affects regeneration of the planarian species Dugesia japonica on the ISS. While we were unable to successfully study planarian regeneration within the experimental constraints of our SSEP Mission, we systematically analyzed the cause for the failed experiment, leading us to propose a modified protocol. This work thus opens the door for future experiments on the effects of microgravity on planarian regeneration on SSEP Missions as well as for more advanced experiments by professional researchers.

  18. X-ray polarimetry. [aboard Ariel 5 and OSO 8 for observation of galactic sources

    Science.gov (United States)

    Long, K. S.; Chanan, G. A.; Helfand, D. J.; Ku, W. H.-M.; Novick, R.

    1979-01-01

    The method by which the Bragg-crystal X-ray polarimeters aboard Ariel 5 and OSO 8 operate is briefly described, and some results obtained with these instruments for six Galactic X-ray sources are summarized. A precision measurement of the linear polarization in the Crab Nebula at energies of 2.6 and 5.2 keV is presented. Evidence is given for polarization in Sco X-1, Cyg X-2, Cen X-3, and the X-ray transient A0620-00. The determined or estimated polarizations are approximately 19.2% at 2.6 keV and 19.5% at 5.2 keV for the Crab Nebula, 1.1% at 2.6 keV and 2.4% at 5.2 keV for Sco X-1, 2.5% at 2.6 keV and 9.8% at 5.2 keV for Cyg X-1, an upper limit of 13.5% for A0620-00, an upper limit of 13.5% to the time-averaged polarization of Cen X-3, and an apparent value of about 5% for Cyg X-2.

  19. Radon-222 measurements aboard an airplane for the description of atmospheric diffusion

    International Nuclear Information System (INIS)

    Bogen, J.

    1973-01-01

    Radon-222 is absorbed aboard an airplane in tubes filled with 50 g of selected charcoal and cooked in Dewars by carbon dioxide and freon. After air collection at different heights up to 5 km, the tubes are evacuated and heated in the laboratory for desorption of the gas molecules and for transfer into a decay chamber covered with zinc-sulfide serving as a scintillator for the detection of alpha activity from radon-222 and its daughters. In general, the measurements show an exponential decrease of the concentration up to 5 km in height, if there is no cloud layer. The height for a reduction by a factor of two is about 900 meters. Assuming a constant diffusion coefficient K 0 up to 5 km, the measurements yield a K 0 of approximately 3.7 x 10 4 cm 2 s -1 . For flights in stratiform clouds a decrease is observed of the concentration up to a certain height, then radon-222 is again increasing or remains constant. This must be explained with respect to the meteorological situation. Assuming only a constant value for K 0 between the different flying heights, it was possible to appraise the development of the eddy diffusion coefficient with height

  20. Trace Gas Measurements Along the South Korean Coast Aboard the Jangmok During KOCOA

    Science.gov (United States)

    Erickson, M.; Stauffer, R. M.; Thompson, A. M.; Flynn, J. H., III

    2017-12-01

    The University of Houston deployed four instruments aboard the Jangmok during the KOrean Coastal water Ocean & Atmosphere (KOCOA) project to quantify O3, NOx, CO, and SO2 along the South Korea coast. The study explores influences of China pollution transport, estimation of the East Asia O3 background, comparisons with ground, ship, and airborne based measurements, and potential source regions along the coast. The Jangmok sailed from May 20 to June 5, 2016 from Ulsan on the east coast traversing along the southern coast to Bigeum in the west. The ship docked each night and measurements were collected only while the vessel was at sea. Sampling was divided into three profiles: anchored, drifting, and transits. Measurements while anchored and drifting provide good temporal data in a small area while transit data provide spatial coverage. The combination of sampling profiles give a better understanding of pollutants over the open water around southern Korea. A few case studies address pollutant transport from China, exploration of the relatively high East Asia O3 background, and coastal emissions along the Jangmok route and ports. The KOCOA project was conducted at the same time as the KORUS project, which provides a number of measurement platforms to compare observations. The Onnuri vessel was sailing as part of the KORUS-OC, while KORUS-AQ included a number of NIER monitoring sites and aircraft measurements. While a number of factors limited close proximity measurements with the other platforms, comparisons were explored where applicable.

  1. Focal plane instrument for the Solar UV-Vis-IR Telescope aboard SOLAR-C

    Science.gov (United States)

    Katsukawa, Yukio; Suematsu, Yoshinori; Shimizu, Toshifumi; Ichimoto, Kiyoshi; Takeyama, Norihide

    2011-10-01

    It is presented the conceptual design of a focal plane instrument for the Solar UV-Vis-IR Telescope (SUVIT) aboard the next Japanese solar mission SOLAR-C. A primary purpose of the telescope is to achieve precise as well as high resolution spectroscopic and polarimetric measurements of the solar chromosphere with a big aperture of 1.5 m, which is expected to make a significant progress in understanding basic MHD processes in the solar atmosphere. The focal plane instrument consists of two packages: A filtergraph package is to get not only monochromatic images but also Dopplergrams and magnetograms using a tunable narrow-band filter and interference filters. A spectrograph package is to perform accurate spectro-polarimetric observations for measuring chromospheric magnetic fields, and is employing a Littrow-type spectrograph. The most challenging aspect in the instrument design is wide wavelength coverage from 280 nm to 1.1 μm to observe multiple chromospheric lines, which is to be realized with a lens unit including fluoride glasses. A high-speed camera for correlation tracking of granular motion is also implemented in one of the packages for an image stabilization system, which is essential to achieve high spatial resolution and high polarimetric accuracy.

  2. Which Ballast Water Management System Will You Put Aboard? Remnant Anxieties: A Mini-Review

    Directory of Open Access Journals (Sweden)

    William R. Batista

    2017-08-01

    Full Text Available An accepted solution to the environmental problems related to a ship’s ballast water has been the adoption and proper utilization of approved onboard ballast water plans and management systems (BWMS. On 8 September 2017, the International Maritime Organization Ballast Water Management Convention comes into force, and under this Convention, ships engaged in international trade must have an approved BWMS aboard to discharge ballast water, reducing species transfer. In response to enormous global concern about this problem, the overwhelming majority of the BWMS, approved currently for use by International Maritime Organization (IMO and United States Coast Guard, utilize two main technologies (electro-chlorination or ultraviolet irradiation as their principle mode of disinfection, often used in combination with filtration. However, both technologies have been questioned regarding their practically, efficiency, and possible environmental impacts upon discharge. This review article aims to explore some questions about these two technologies, drawing attention to some current uncertainties associated with their use. Also, it draws attention to some technical obstacles and regulatory impediments related to the new development of green biocide technology, which largely has been ignored, despite its potential as a simpler, cleaner and effective technology.

  3. Characterization of the Protein Crystal Growth Apparatus for Microgravity Aboard the Space Station

    Science.gov (United States)

    Kundrot, Craig E.; Roeber, D.; Achari, A.; Stinson, Thomas N. (Technical Monitor)

    2002-01-01

    We have conducted experiments to determine the equilibration rates of some major precipitants used in protein crystallography aboard the International Space Station (ISS). The solutions were placed in the Protein Crystallization Apparatus for Microgravity (PCAM) which mimic Cryschem sitting drop trays. The trays were placed in cylinders. These cylinders were placed inside a Single locker Thermal Enclosure System (STES), and were activated for different durations during the flight. Bumpers pressed against elastomers seal drops in a deactivated state during pre-flight and prior to transfer to the ISS. Activation occurs while in flight on the ISS by releasing the bumpers allowing the drops to be exposed to the reservoir. PCAM was flown to the ISS on STS 100, Flight 6A, on April 19, 2001. Six series of equilibration experiments were tested for each precipitant with a small amount of Green Fluorescent Protein (GFP). Cylinder 10 was never activated, 7 was activated for 40 days, 8 was activated for 20 days, 9 was activated for 10 days, 11 was activated for 4 days and 12 was activated for 2 days. Upon the return to Earth by STS 104 on July 24,2001 the samples were transferred to Marshall Space Flight Center. The samples were then brought to the lab and the volumes of each sample were measured.

  4. AllAboard: Visual Exploration of Cellphone Mobility Data to Optimise Public Transport.

    Science.gov (United States)

    Di Lorenzo, G; Sbodio, M; Calabrese, F; Berlingerio, M; Pinelli, F; Nair, R

    2016-02-01

    The deep penetration of mobile phones offers cities the ability to opportunistically monitor citizens' mobility and use data-driven insights to better plan and manage services. With large scale data on mobility patterns, operators can move away from the costly, mostly survey based, transportation planning processes, to a more data-centric view, that places the instrumented user at the center of development. In this framework, using mobile phone data to perform transit analysis and optimization represents a new frontier with significant societal impact, especially in developing countries. In this paper we present AllAboard, an intelligent tool that analyses cellphone data to help city authorities in visually exploring urban mobility and optimizing public transport. This is performed within a self contained tool, as opposed to the current solutions which rely on a combination of several distinct tools for analysis, reporting, optimisation and planning. An interactive user interface allows transit operators to visually explore the travel demand in both space and time, correlate it with the transit network, and evaluate the quality of service that a transit network provides to the citizens at very fine grain. Operators can visually test scenarios for transit network improvements, and compare the expected impact on the travellers' experience. The system has been tested using real telecommunication data for the city of Abidjan, Ivory Coast, and evaluated from a data mining, optimisation and user prospective.

  5. Comparison of Directionally Solidified Samples Solidified Terrestrially and Aboard the International Space Station

    Science.gov (United States)

    Angart, S.; Lauer, M.; Tewari, S. N.; Grugel, R. N.; Poirier, D. R.

    2014-01-01

    This article reports research that has been carried out under the aegis of NASA as part of a collaboration between ESA and NASA for solidification experiments on the International Space Station (ISS). The focus has been on the effect of convection on the microstructural evolution and macrosegregation in hypoeutectic Al-Si alloys during directional solidification (DS). Terrestrial DS-experiments have been carried out at Cleveland State University (CSU) and under microgravity on the International Space Station (ISS). The thermal processing-history of the experiments is well defined for both the terrestrially processed samples and the ISS-processed samples. As of this writing, two dendritic metrics was measured: primary dendrite arm spacings and primary dendrite trunk diameters. We have observed that these dendrite-metrics of two samples grown in the microgravity environment show good agreements with models based on diffusion controlled growth and diffusion controlled ripening, respectively. The gravity-driven convection (i.e., thermosolutal convection) in terrestrially grown samples has the effect of decreasing the primary dendrite arm spacings and causes macrosegregation. Dendrite trunk diameters also show differences between the earth- and space-grown samples. In order to process DS-samples aboard the ISS, the dendritic seed crystals were partially remelted in a stationary thermal gradient before the DS was carried out. Microstructural changes and macrosegregation effects during this period are described and have modeled.

  6. Innovative Sea Surface Monitoring with GNSS-Reflectometry aboard ISS: Overview and Recent Results from GEROS-ISS

    DEFF Research Database (Denmark)

    Wickert, Jens; Andersen, Ole Baltazar; Bandeiras, J.

    GEROS-ISS (GEROS hereafter) stands for GNSS REflectometry, Radio Occultation and Scatterometry onboard the International Space Station. It is a scientific experiment, proposed to the European Space Agency (ESA)in 2011 for installation aboard the ISS. The main focus of GEROS is the dedicated use o...... of signals from the currently available Global Navigation Satellite Systems (GNSS) for remote sensing of the System Earth with focus to Climate Change characterisation. The GEROS mission idea and the current status are briefly reviewed....

  7. Requirements and specifications for a particle database

    International Nuclear Information System (INIS)

    2015-01-01

    One of the tasks of WPEC Subgroup 38 (SG38) is to design a database structure for storing the particle information needed for nuclear reaction databases and transport codes. Since the same particle may appear many times in a reaction database (produced by many different reactions on different targets), one of the long-term goals for SG38 is to move towards a central database of particle information to reduce redundancy and ensure consistency among evaluations. The database structure must be general enough to describe all relevant particles and their properties, including mass, charge, spin and parity, half-life, decay properties, and so on. Furthermore, it must be broad enough to handle not only excited nuclear states but also excited atomic states that can de-excite through atomic relaxation. Databases built with this hierarchy will serve as central repositories for particle information that can be linked to from codes and other databases. It is hoped that the final product is general enough for use in other projects besides SG38. While this is called a 'particle database', the definition of a particle (as described in Section 2) is very broad. The database must describe nucleons, nuclei, excited nuclear states (and possibly atomic states) in addition to fundamental particles like photons, electrons, muons, etc. Under this definition the list of possible particles becomes quite large. To help organize them the database will need a way of grouping related particles (e.g., all the isotopes of an element, or all the excited levels of an isotope) together into particle 'groups'. The database will also need a way to classify particles that belong to the same 'family' (such as 'leptons', 'baryons', etc.). Each family of particles may have special requirements as to what properties are required. One important function of the particle database will be to provide an easy way for codes and external databases to look up any particle stored inside. In order to make access as

  8. ``Out To Sea: Life as a Crew Member Aboard a Geologic Research Ship'' - Production of a Video and Teachers Guide.

    Science.gov (United States)

    Rack, F. R.; Tauxe, K.

    2004-12-01

    In May 2002, Joint Oceanographic Institutions (JOI) received a proposal entitled "Motivating Middle School Students with the JOIDES Resolution", from a middle school teacher in New Mexico named Katie Tauxe. Katie was a former Marine Technician who has worked aboard the R/V JOIDES Resolution in the early years of the Ocean Drilling Program (ODP). She proposed to engage the interest of middle school students using the ODP drillship as the centerpiece of a presentation focused on the lives of the people who work aboard the ship and the excitement of science communicated through an active shipboard experience. The proposal asked for travel funds to and from the ship, the loan of video camera equipment from JOI, and a small amount of funding to cover expendable supplies, video editing, and production at the local Public Broadcasting Station in Los Alamos, NM. Katie sailed on the transit of the JOIDES Resolution through the Panama Canal, following the completion of ODP Leg 206 in late 2002. This presentation will focus on the outcome of this video production effort, which is a 19 minute-long video entitled "Out to Sea: Life as a Crew Member Aboard a Geologic Research Ship", and a teacher's guide that can be found online.

  9. Traffic of indistinguishable particles in complex networks

    International Nuclear Information System (INIS)

    Qing-Kuan, Meng; Jian-Yang, Zhu

    2009-01-01

    In this paper, we apply a simple walk mechanism to the study of the traffic of many indistinguishable particles in complex networks. The network with particles stands for a particle system, and every vertex in the network stands for a quantum state with the corresponding energy determined by the vertex degree. Although the particles are indistinguishable, the quantum states can be distinguished. When the many indistinguishable particles walk randomly in the system for a long enough time and the system reaches dynamic equilibrium, we find that under different restrictive conditions the particle distributions satisfy different forms, including the Bose–Einstein distribution, the Fermi–Dirac distribution and the non-Fermi distribution (as we temporarily call it). As for the Bose–Einstein distribution, we find that only if the particle density is larger than zero, with increasing particle density, do more and more particles condense in the lowest energy level. While the particle density is very low, the particle distribution transforms from the quantum statistical form to the classically statistical form, i.e., transforms from the Bose distribution or the Fermi distribution to the Boltzmann distribution. The numerical results fit well with the analytical predictions

  10. Historical underway surface temperature data collected aboard the ship Skelton Castle on a voyage from England to India, 28 February 1800 to 3 June 1800 (NODC Accession 0095925)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Underway surface air temperature and sea water temperature were collected aboard the Skelton Castle while in route from England to Bombay India as part of the East...

  11. Bottle profile data collected aboard the USCGC SENECA in the Atlantic Ocean from 2 April 1915 to 20 May 1915 (NODC Accession 9700096)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 9700096 contains temperature and salinity profile data from bottle casts collected aboard the USCGC Seneca in the Grand Banks of Newfoundland and...

  12. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Oscar Elton Sette in the North Pacific Ocean on 2016-06-22 (NCEI Accession 0155170)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0155170 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  13. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Ronald H. Brown in the Bering Sea on 2015-09-04 (NCEI Accession 0137446)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NODC Accession 0137446 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  14. Underway meteorological, navigational, physical and time series data collected aboard NOAA Ship Henry B. Bigelow in the North Atlantic Ocean on 2016-08-26 (NCEI Accession 0162238)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NCEI Accession 0162238 contains raw underway meteorological, navigational, physical and time series data logged by the Scientific Computer System (SCS) aboard NOAA...

  15. Power and particle control

    International Nuclear Information System (INIS)

    1999-01-01

    The ability to exhaust the plasma power loss from a large tokamak onto material walls surrounding the plasma has been perceived to be a large obstacle to the successful production of a fusion power reactor in the past. There have been tremendous strides in understanding the physics relevant to this power exhaust over the past five years. This improvement in understanding has arisen because of both improved diagnostics of the plasma outside the last closed flux surface, and because of improved two dimensional computer models of this plasma. This understanding has led to innovative plasma solutions that reduce the power load to the divertor region of ITER to levels that are acceptable for a successful engineering design of the divertors. These plasma solutions have been realized in the devices that are active today. Analysis using the improved plasma models also indicates that particle control, both of fuel and impurity particles, is adequate for successful operation of ITER. This paper presents the current status of both the experimental and theoretical understanding of the plasma, neutral and atomic physics relevant to the plasma at the edge of fusion devices. Since understanding of the subject of this paper is progressing rapidly, we should emphasize that this paper was written in the spring of 1998 and, as such, presents the status of the subject at that time. (author)

  16. Particle physics---Experimental

    International Nuclear Information System (INIS)

    Lord, J.J.; Boynton, P.E.; Burnett, T.H.; Wilkes, R.J.

    1991-01-01

    We are continuing a research program in particle astrophysics and high energy experimental particle physics. We have joined the DUMAND Collaboration, which is constructing a deep undersea astrophysical neutrino detector near Hawaii. Studies of high energy hadronic interactions using emulsion chamber techniques were also continued, using balloon flight exposures to ultra-high cosmic ray nuclei (JACEE) and accelerator beams. As members of the DUMAND Collaboration, we have responsibility for development a construction of critical components for the deep undersea neutrino detector facility. We have designed and developed the acoustical positioning system required to permit reconstruction of muon tracks with sufficient precision to meet the astrophysical goals of the experiment. In addition, we are making significant contributions to the design of the database and triggering system to be used. Work has been continuing in other aspects of the study of multiparticle production processes in nuclei. We are participants in a joint US/Japan program to study nuclear interactions at energies two orders of magnitude greater than those of existing accelerators, using balloon-borne emulsion chambers. On one of the flights we found two nuclear interactions of multiplicity over 1000 -- one with a multiplicity of over 2000 and pseudorapidity density ∼ 800 in the central region. At the statistical level of the JACEE experiment, the frequency of occurrence of such events is orders of magnitude too large. We have continued our ongoing program to study hadronic interactions in emulsions exposed to high energy accelerator beams

  17. Removal of ultrafine particles from indoor environment

    DEFF Research Database (Denmark)

    Ardkapan, Siamak Rahimi

    in a CFD simulation or if particles are considered of one single size, a deviation from reality may occur. It was concluded that an ozone generating air cleaning technology may increase the level of ozone to a level that exceeds the allowed level of 120 μgm-3 according to Air Quality Guidelines for Europe...... effect on the removal effectiveness in a room with a displacement airflow pattern. According to the simulation study of particle dispersion in a room, it was concluded that the location of a particle source has impact on the UFP concentration profile in the room....

  18. Shannon entropy and particle decays

    Science.gov (United States)

    Carrasco Millán, Pedro; García-Ferrero, M. Ángeles; Llanes-Estrada, Felipe J.; Porras Riojano, Ana; Sánchez García, Esteban M.

    2018-05-01

    We deploy Shannon's information entropy to the distribution of branching fractions in a particle decay. This serves to quantify how important a given new reported decay channel is, from the point of view of the information that it adds to the already known ones. Because the entropy is additive, one can subdivide the set of channels and discuss, for example, how much information the discovery of a new decay branching would add; or subdivide the decay distribution down to the level of individual quantum states (which can be quickly counted by the phase space). We illustrate the concept with some examples of experimentally known particle decay distributions.

  19. Controlled Directional Solidification of Aluminum - 7 wt Percent Silicon Alloys: Comparison Between Samples Processed on Earth and in the Microgravity Environment Aboard the International Space Station

    Science.gov (United States)

    Grugel, Richard N.; Tewari, Surendra N.; Erdman, Robert G.; Poirier, David R.

    2012-01-01

    An overview of the international "MIcrostructure Formation in CASTing of Technical Alloys" (MICAST) program is given. Directional solidification processing of metals and alloys is described, and why experiments conducted in the microgravity environment aboard the International Space Station (ISS) are expected to promote our understanding of this commercially relevant practice. Microstructural differences observed when comparing the aluminum - 7 wt% silicon alloys directionally solidified on Earth to those aboard the ISS are presented and discussed.

  20. Particles and nuclei, letters

    International Nuclear Information System (INIS)

    2004-01-01

    The present collection of letters from JINR, Dubna, contains nine separate letters on nonlocal chiral quark model with confinement, perturbation of finite-lattice spectral levels by nearby nuclear resonances, on the application of 'Z 0 + jet' events for determining the gluon distribution in a proton at the LHC, account of light velocity constancy in the Galilean problem on the free movement of a particle and its fall onto the ground, first results of crystal deflector investigations at the Nuclotron external beams, decay parameters of K mesons, measured at proton synchrotron U-70 using 'Hyperon' set-up and modern world data, prototype of atomic-emission spectrometer on the basis of one-electrode impulse RF discharge for analytical measurements, polarimeter for Nuclotron internal beam and primordial bubbles of colour superconducting quark matter

  1. Particle physics: a new course for schools and colleges

    International Nuclear Information System (INIS)

    Swinbank, Elizabeth

    1992-01-01

    Some questions relating to the introduction of particle physics into post-GCSE courses are considered. A new project that is producing teacher and student materials to support teaching particle physics at this level is described. (author)

  2. GNSS reflectometry aboard the International Space Station: phase-altimetry simulation to detect ocean topography anomalies

    Science.gov (United States)

    Semmling, Maximilian; Leister, Vera; Saynisch, Jan; Zus, Florian; Wickert, Jens

    2016-04-01

    An ocean altimetry experiment using Earth reflected GNSS signals has been proposed to the European Space Agency (ESA). It is part of the GNSS Reflectometry Radio Occultation Scatterometry (GEROS) mission that is planned aboard the International Space Station (ISS). Altimetric simulations are presented that examine the detection of ocean topography anomalies assuming GNSS phase delay observations. Such delay measurements are well established for positioning and are possible due to a sufficient synchronization of GNSS receiver and transmitter. For altimetric purpose delays of Earth reflected GNSS signals can be observed similar to radar altimeter signals. The advantage of GNSS is the synchronized separation of transmitter and receiver that allow a significantly increased number of observation per receiver due to more than 70 GNSS transmitters currently in orbit. The altimetric concept has already been applied successfully to flight data recorded over the Mediterranean Sea. The presented altimetric simulation considers anomalies in the Agulhas current region which are obtained from the Region Ocean Model System (ROMS). Suitable reflection events in an elevation range between 3° and 30° last about 10min with ground track's length >3000km. Typical along-track footprints (1s signal integration time) have a length of about 5km. The reflection's Fresnel zone limits the footprint of coherent observations to a major axis extention between 1 to 6km dependent on the elevation. The altimetric performance depends on the signal-to-noise ratio (SNR) of the reflection. Simulation results show that precision is better than 10cm for SNR of 30dB. Whereas, it is worse than 0.5m if SNR goes down to 10dB. Precision, in general, improves towards higher elevation angles. Critical biases are introduced by atmospheric and ionospheric refraction. Corresponding correction strategies are still under investigation.

  3. Initial Results from the STEM Student Experiences Aboard Ships (STEMSEAS) Program

    Science.gov (United States)

    Lewis, J. C.; Cooper, S. K.; Thomson, K.; Rabin, B.; Alberts, J.

    2016-12-01

    The Science Technology Engineering and Math Student Experiences Aboard Ships (STEMSEAS) program was created as a response to NSF's call (through GEOPATHS) for improving undergraduate STEM education and enhancing diversity in the geosciences. It takes advantage of unused berths on UNOLS ships during transits between expeditions. During its 2016 pilot year - which consisted of three transits on three different research vessels in different parts of the country, each with a slightly different focus - the program has gained significant insights into how best to create and structure these opportunities and create impact on individual students. A call for applications resulted in nearly 900 applicants for 30 available spots. Of these applicants, 32% are from minority groups underrepresented in the geosciences (Black, Hispanic, or American Indian) and 20% attend community colleges. The program was able to sail socioeconomically diverse cohorts and include women, veterans, and students with disabilities and from two- and four-year colleges. Twenty-three are underrepresented minorities, 6 attend community colleges, 5 attend an HBCU or tribal college, and many are at HSIs or other MSIs. While longer term impact assessment will have to wait, initial results and 6-month tracking for the first cohort indicate that these kinds of relatively short but intense experiences can indeed achieve significant impacts on students' perception of the geosciences, in their understanding of STEM career opportunities, their desire to work in a geoscience lab setting, and to incorporate geosciences into non-STEM careers. Insights were also gained into the successful makeup of mentor/leader groups, factors to consider in student selection, necessary pre- and post-cruise logistics management, follow-up activities, structure of activities during daily life at sea, increasing student networks and access to mentorships, and leveraging of pre-existing resources and ship-based opportunities

  4. High-energy electron experiments (HEP) aboard the ERG (Arase) satellite

    Science.gov (United States)

    Mitani, Takefumi; Takashima, Takeshi; Kasahara, Satoshi; Miyake, Wataru; Hirahara, Masafumi

    2018-05-01

    This paper reports the design, calibration, and operation of high-energy electron experiments (HEP) aboard the exploration of energization and radiation in geospace (ERG) satellite. HEP detects 70 keV-2 MeV electrons and generates a three-dimensional velocity distribution for these electrons in every period of the satellite's rotation. Electrons are detected by two instruments, namely HEP-L and HEP-H, which differ in their geometric factor (G-factor) and range of energies they detect. HEP-L detects 70 keV-1 MeV electrons and its G-factor is 9.3 × 10-4 cm2 sr at maximum, while HEP-H observes 0.7-2 MeV electrons and its G-factor is 9.3 × 10-3 cm2 sr at maximum. The instruments utilize silicon strip detectors and application-specific integrated circuits to readout the incident charge signal from each strip. Before the launch, we calibrated the detectors by measuring the energy spectra of all strips using γ-ray sources. To evaluate the overall performance of the HEP instruments, we measured the energy spectra and angular responses with electron beams. After HEP was first put into operation, on February 2, 2017, it was demonstrated that the instruments performed normally. HEP began its exploratory observations with regard to energization and radiation in geospace in late March 2017. The initial results of the in-orbit observations are introduced briefly in this paper.[Figure not available: see fulltext.

  5. The Capillary Flow Experiments Aboard the International Space Station: Increments 9-15

    Science.gov (United States)

    Jenson, Ryan M.; Weislogel, Mark M.; Tavan, Noel T.; Chen, Yongkang; Semerjian, Ben; Bunnell, Charles T.; Collicott, Steven H.; Klatte, Jorg; dreyer, Michael E.

    2009-01-01

    This report provides a summary of the experimental, analytical, and numerical results of the Capillary Flow Experiment (CFE) performed aboard the International Space Station (ISS). The experiments were conducted in space beginning with Increment 9 through Increment 16, beginning August 2004 and ending December 2007. Both primary and extra science experiments were conducted during 19 operations performed by 7 astronauts including: M. Fincke, W. McArthur, J. Williams, S. Williams, M. Lopez-Alegria, C. Anderson, and P. Whitson. CFE consists of 6 approximately 1 to 2 kg handheld experiment units designed to investigate a selection of capillary phenomena of fundamental and applied importance, such as large length scale contact line dynamics (CFE-Contact Line), critical wetting in discontinuous structures (CFE-Vane Gap), and capillary flows and passive phase separations in complex containers (CFE-Interior Corner Flow). Highly quantitative video from the simply performed flight experiments provide data helpful in benchmarking numerical methods, confirming theoretical models, and guiding new model development. In an extensive executive summary, a brief history of the experiment is reviewed before introducing the science investigated. A selection of experimental results and comparisons with both analytic and numerical predictions is given. The subsequent chapters provide additional details of the experimental and analytical methods developed and employed. These include current presentations of the state of the data reduction which we anticipate will continue throughout the year and culminate in several more publications. An extensive appendix is used to provide support material such as an experiment history, dissemination items to date (CFE publication, etc.), detailed design drawings, and crew procedures. Despite the simple nature of the experiments and procedures, many of the experimental results may be practically employed to enhance the design of spacecraft engineering

  6. Accelerators of atomic particles

    International Nuclear Information System (INIS)

    Sarancev, V.

    1975-01-01

    A brief survey is presented of accelerators and methods of accelerating elementary particles. The principle of collective accelerating of elementary particles is clarified and the problems are discussed of its realization. (B.S.)

  7. Elementary particles and cosmology

    International Nuclear Information System (INIS)

    Audouze, J.; Paty, M.

    2000-01-01

    The universe is the most efficient laboratory of particle physics and the understanding of cosmological processes implies the knowledge of how elementary particles interact. This article recalls the mutual influences between on the one hand: astrophysics and cosmology and on the other hand: nuclear physics and particle physics. The big-bang theory relies on nuclear physics to explain the successive stages of nucleo-synthesis and the study of solar neutrinos has led to discover new aspects of this particle: it is likely that neutrinos undergo oscillations from one neutrino type to another. In some universe events such as the bursting of a super-nova, particles are released with a kinetic energy that would be impossible to reach on earth with a particle accelerator. These events are become common points of interest between astrophysicists and particle physicists and have promoted a deeper cooperation between astrophysics and elementary particle physics. (A.C.)

  8. Particle Physics Education Sites

    Science.gov (United States)

    back to home page Particle Physics Education Sites quick reference Education and Information - National Laboratory Education Programs - Women and Minorities in Physics - Other Physics Sites - Physics Alliance - Accelerators at National Laboratories icon Particle Physics Education and Information sites: top

  9. Review of particle properties

    Energy Technology Data Exchange (ETDEWEB)

    Yost, G P; Barnett, R M; Hinchliffe, I; Lynch, G R; Rittenberg, A; Ross, R R; Suzuki, M; Trippe, T G; Wohl, C G; Armstrong, B

    1988-04-14

    This review of the properties of gauge bosons, leptons, mesons, and baryons is an updating of the Review of Particle Properties, Particle Data Group (Phys. Lett. 170B (1986)). Data are evaluated, listed, averaged, and summarized in tables. We continue the more orderly set of particle names implemented in the 1986 edition. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available.

  10. Beyond the God particle

    CERN Document Server

    Lederman, Leon M

    2013-01-01

    On July 4, 2012, the long-sought Higgs Boson--aka "the God Particle"--was discovered at the world's largest particle accelerator, the LHC, in Geneva, Switzerland. On March 14, 2013, physicists at CERN confirmed it. This elusive subatomic particle forms a field that permeates the entire universe, creating the masses of the elementary particles that are the basic building blocks of everything in the known world--from viruses to elephants, from atoms to quasars.

  11. Numerical Study of Particle Interaction in Gas-Particle and Liquid-Particle Flows: Part II Particle Response

    Directory of Open Access Journals (Sweden)

    K. Mohanarangam

    2009-09-01

    Full Text Available In this paper the numerical model, which was presented in the first paper (Mohanarangam & Tu; 2009 of this series of study, is employed to study the different particle responses under the influence of two carrier phases namely the gas and the liquid. The numerical model takes into consideration the turbulent behaviour of both the carrier and the dispersed phases, with additional equations to take into account the combined fluid particle behaviour, thereby effecting a two-way coupling. The first paper in this series showed the distinct difference in particulate response both at the mean as well as at the turbulent level for two varied carrier phases. In this paper further investigation has been carried out over a broad range of particle Stokes number to further understand their behaviour in turbulent environments. In order to carry out this prognostic study, the backward facing step geometry of Fessler and Eaton (1999 has been adopted, while the inlet conditions for the carrier as well as the particle phases correspond to that of the experiments of Founti and Klipfel (1998. It is observed that at the mean velocity level the particulate velocities increased with a subsequent increase in the Stokes number for both the GP (Gas-Particle as well as the LP (Liquid-Particle flow. It was also observed that across the Stokes number there was a steady increase in the particulate turbulence for the GP flows with successive increase in Stokes number. However, for the LP flows, the magnitude of the increase in the particulate turbulence across the increasing of Stokes number is not as characteristic as the GP flow. Across the same sections for LP flows the majority of the trend shows a decrease after which they remain more or less a constant.

  12. Particle physics and cosmology

    International Nuclear Information System (INIS)

    Schramm, D.N.; Turner, M.S.

    1982-06-01

    work is described in these areas: cosmological baryon production; cosmological production of free quarks and other exotic particle species; the quark-hadron transition in the early universe; astrophysical and cosmological constraints on particle properties; massive neutrinos; phase transitions in the early universe; and astrophysical implications of an axion-like particle

  13. Particle-nuclear intersections

    International Nuclear Information System (INIS)

    Anon.

    1994-01-01

    With the traditional distinctions between particle and nuclear physics becoming increasing blurred, the Fifth Conference on the Intersections of Particle and Nuclear Physics, held from May 31 to June 6 in St. Petersburg, Florida, brought together particle and nuclear physicists to discuss common research efforts and to define and plan a united approach

  14. Review of particle properties

    International Nuclear Information System (INIS)

    Trippe, T.G.; Barbaro-Galtieri, A.; Kelly, R.L.; Rittenberg, A.; Rosenfeld, A.H.; Yost, G.P.; Barash-Schmidt, N.; Bricman, C.; Hemingway, R.J.; Losty, M.J.; Roos, M.; Chaloupka, V.; Armstrong, B.

    1976-01-01

    This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Phys. Letters 50B, No.1 (1974), and Supplement, Rev. Mod. Phys. 47 (1975) 535]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available

  15. Atomic Particle Detection

    Energy Technology Data Exchange (ETDEWEB)

    Hellman, Hal

    1970-01-01

    This booklet tells how scientists observe the particles and electromagnetic radiation that emerges from an atomic nucleus. The equipment used falls into two general categories: counters which count each particle as it passes by, and track detectors, which make a photographic record of the particle's track.

  16. Particle cosmology comes of age

    International Nuclear Information System (INIS)

    Turner, M.S.

    1988-01-01

    The application of modern ideas in particle physics to astrophysical and cosmological settings is a continuation of a fruitful tradition in astrophysics which began with the application of atomic physics, and then nuclear physics. In the past decade particle cosmology and particle astrophysics have been recognized as 'legitimate activities' by both particle physicists and astrophysicists and astronomers. During this time there has been a high level of theoretical activity producing much speculation about the earliest history of the Universe, as well as important and interesting astrophysical and cosmological constraints to particle physics theories. This period of intense theoretical activity has produced a number of ideas most worthy of careful consideration and scrutiny, and even more importantly, amenable to experimental/observational test. Among the ideas which are likely to be tested in the next decade are: the cosmological bound to the number of neutrino flavors, inflation, relic WIMPs as the dark matter, and MSW neutrino oscillations as a solution to the solar neutrino problems. (orig.)

  17. Particle cosmology comes of age

    International Nuclear Information System (INIS)

    Turner, M.S.

    1987-12-01

    The application of modern ideas in particle physics to astrophysical and cosmological settings is a continuation of a fruitful tradition in astrophysics which began with the application of atomic physics, and then nuclear physics. In the past decade particle cosmology and particle astrophysics have been recognized as 'legitimate activities' by both particle physicists and astrophysicists and astronomers. During this time there has been a high level of theoretical activity producing much speculation about the earliest history of the Universe, as well as important and interesting astrophysical and cosmological constraints to particle physics theories. This period of intense theoretical activity has produced a number of ideas most worthy of careful consideration and scrutiny, and even more importantly, amenable to experimental/observational test. Among the ideas which are likely to be tested in the next decade are: the cosmological bound to the number of neutrino flavors, inflation, relic WIMPs as the dark matter, and MSW neutrino oscillations as a solution to the solar neutrino problems. 94 refs

  18. Particle Emissions from Domestic Gas Cookers

    DEFF Research Database (Denmark)

    Glarborg, Peter; Livbjerg, Hans; Wagner, Ayten Yilmaz

    2010-01-01

    The authors experimentally studied the formation of submicron particles from a domestic gas cooker in a compartment free from external particle sources. The effects of fuel (methane, natural gas, odorant-free natural gas), primary aeration, flow rate, and fuel sulphur content on particle emissions...... of the emitted particles were found to have a mean value of about 7 nm for partially premixed flames, increasing to ∼10 nm for nonpremixed flames. The quantity of primary air had a strong impact on the particle emissions, showing a minimum at a primary aeration level of 60-65%. Presence of sulphur in small...... quantities may enhance particle formation under some conditions, but results were not conclusive....

  19. Study of particle swarm optimization particle trajectories

    CSIR Research Space (South Africa)

    Van den Bergh, F

    2006-01-01

    Full Text Available . These theoretical studies concentrate mainly on simplified PSO systems. This paper overviews current theoretical studies, and extend these studies to investigate particle trajectories for general swarms to include the influence of the inertia term. The paper also...

  20. Light scattering by cosmic particles

    NARCIS (Netherlands)

    Hovenier, J.W.; Min, M.

    2008-01-01

    We define cosmic particles as particles outside the Earth. Two types of cosmic particles can be distinguished, namely liquid and solid particles. The solid particles are often called grains or cosmic dust particles. Cosmic particles occur in a great variety of astronomical objects and environments.

  1. Slowing of charged particles by particle methods

    International Nuclear Information System (INIS)

    Mercier, B.

    1985-03-01

    We review some facts about particle methods for solving linear hyperbolic equations. We show how one gets an evaluation of integral quantities like: ∫ u(x,t) zeta(x,t) dxdt where u denotes the solution and zeta an arbitrary weight function. Then, we apply the method to the equation describing charged particle transport in a plasma with emphasis on the evaluation of energy deposition on ions and electrons [fr

  2. Elementary particles. 2

    International Nuclear Information System (INIS)

    Ranft, G.; Ranft, J.

    1977-01-01

    In this part the subject is covered under the following headings, methods for producing high-energy particles; interaction of high-energy particles with matter; methods for the detection of high-energy particles; symmetry properties and conservation laws; quantum number and selection rules; theorem of scattering behaviour at asymptotically high energies; statistical methods in elementary particle physics; interaction of high-energy particles with nuclei; relations of high-energy physics to other branches of science and its response to engineering. Intended as information on high-energy physics for graduate students and research workers familiar with the fundamentals of classical and quantum physics

  3. Review of particle properties

    International Nuclear Information System (INIS)

    Montanet, L.; Gieselmann, K. Technical Associate; Barnett, R.M.; Groom, D.E.; Trippe, T.G.; Wohl, C.G.; Armstrong, B. Technical Associate; Wagman, G.S. Technical Associate; Murayama, H.; Stone, J.; Hernandez, J.J.; Porter, F.C.; Morrison, R.J.; Manohar, A.; Aguilar-Benitez, M.; Caso, C.; Lantero, P. Technical Associate; Crawford, R.L.; Roos, M.; Toernqvist, N.A.; Hayes, K.G.; Hoehler, G.

    1994-01-01

    This biennial review summarizes much of Particle Physics. Using data from previous editions, plus 2300 new measurements from 700 papers, we list evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, monopoles, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review

  4. Alpha particle emitters in medicine

    International Nuclear Information System (INIS)

    Fisher, D.R.

    1989-09-01

    Radiation-induced cancer of bone, liver and lung has been a prominent harmful side-effect of medical applications of alpha emitters. In recent years, however, the potential use of antibodies labeled with alpha emitting radionuclides against cancer has seemed promising because alpha particles are highly effective in cell killing. High dose rates at high LET, effectiveness under hypoxic conditions, and minimal expectancy of repair are additional advantages of alpha emitters over antibodies labeled with beta emitting radionuclides for cancer therapy. Cyclotron-produced astatine-211 ( 211 At) and natural bismuth-212 ( 212 Bi) have been proposed and are under extensive study in the United States and Europe. Radium-223 ( 223 Ra) also has favorable properties as a potential alpha emitting label, including a short-lived daughter chain with four alpha emissions. The radiation dosimetry of internal alpha emitters is complex due to nonuniformly distributed sources, short particle tracks, and high relative specific ionization. The variations in dose at the cellular level may be extreme. Alpha-particle radiation dosimetry, therefore, must involve analysis of statistical energy deposition probabilities for cellular level targets. It must also account fully for nonuniform distributions of sources in tissues, source-target geometries, and particle-track physics. 18 refs., 4 figs

  5. Fluidization of spherocylindrical particles

    Science.gov (United States)

    Mahajan, Vinay V.; Nijssen, Tim M. J.; Fitzgerald, Barry W.; Hofman, Jeroen; Kuipers, Hans; Padding, Johan T.

    2017-06-01

    Multiphase (gas-solid) flows are encountered in numerous industrial applications such as pharmaceutical, food, agricultural processing and energy generation. A coupled computational fluid dynamics (CFD) and discrete element method (DEM) approach is a popular way to study such flows at a particle scale. However, most of these studies deal with spherical particles while in reality, the particles are rarely spherical. The particle shape can have significant effect on hydrodynamics in a fluidized bed. Moreover, most studies in literature use inaccurate drag laws because accurate laws are not readily available. The drag force acting on a non-spherical particle can vary considerably with particle shape, orientation with the flow, Reynolds number and packing fraction. In this work, the CFD-DEM approach is extended to model a laboratory scale fluidized bed of spherocylinder (rod-like) particles. These rod-like particles can be classified as Geldart D particles and have an aspect ratio of 4. Experiments are performed to study the particle flow behavior in a quasi-2D fluidized bed. Numerically obtained results for pressure drop and bed height are compared with experiments. The capability of CFD-DEM approach to efficiently describe the global bed dynamics for fluidized bed of rod-like particles is demonstrated.

  6. Monosodium titanate particle characterization

    International Nuclear Information System (INIS)

    Chandler, G.T.; Hobbs, D.T.

    1993-01-01

    A characterization study was performed on monosodium titanate (MST) particles to determine the effect of high shear forces expected from the In-Tank Precipitation (ITP) process pumps on the particle size distribution. The particles were characterized using particle size analysis and scanning electron microscopy (SEM). No significant changes in particle size distributions were observed between as-received MST and after 2--4 hours of shearing. Both as-received and sheared MST particles contained a large percentage of porosity with pore sizes on the order of 500 to 2,000 Angstroms. Because of the large percentage of porosity, the overall surface area of the MST is dominated by the internal surfaces. The uranium and plutonium species present in the waste solution will have access to both interior and exterior surfaces. Therefore, uranium and plutonium loading should not be a strong function of MST particle size

  7. Measurement of plasma and energetic charged particles in the proximity of Halley's comet

    International Nuclear Information System (INIS)

    Erdoes, Geza; Gombosi, Tamas; Kecskemety, Karoly; Somogyi, Antal; Tatrallyay, Mariella; Varga, Andras

    1987-01-01

    The instrumentation aboard the space probe VEGA for the exploration of Halley's comet contained the particle analyzers PLAZMAG and TUENDE-M. PLAZMAG was used for the measurement of the interaction between the low-energy solar plasma and the heavy ions from the comet. From the energy spectra measured near the nucleus of the comet the density distribution of ion groups can also be determined. TUENDE-M recorded the distribution of energetic heavy ions from the comet. The properties of various plasma regions within the 10 million km range from the comet's nucleus are discussed in detail. (R.P.)

  8. Tomographic retrieval of cloud liquid water fields from a single scanning microwave radiometer aboard a moving platform – Part 1: Field trial results from the Wakasa Bay experiment

    Directory of Open Access Journals (Sweden)

    D. Huang

    2010-07-01

    Full Text Available Tomographic methods offer great potential for retrieving three-dimensional spatial distributions of cloud liquid water from radiometric observations by passive microwave sensors. Fixed tomographic systems require multiple radiometers, while mobile systems can use just a single radiometer. Part 1 (this paper examines the results from a limited cloud tomography trial with a single-radiometer airborne system carried out as part of the 2003 AMSR-E validation campaign over Wakasa Bay of the Sea of Japan. During this trial, the Polarimetric Scanning Radiometer (PSR and Microwave Imaging Radiometer (MIR aboard the NASA P-3 research aircraft provided a useful dataset for testing the cloud tomography method over a system of low-level clouds. We do tomographic retrievals with a constrained inversion algorithm using three configurations: PSR, MIR, and combined PSR and MIR data. The liquid water paths from the PSR retrieval are consistent with those from the MIR retrieval. The retrieved cloud field based on the combined data appears to be physically plausible and consistent with the cloud image obtained by a cloud radar. We find that some vertically-uniform clouds appear at high altitudes in the retrieved field where the radar shows clear sky. This is likely due to the sub-optimal data collection strategy. This sets the stage for Part 2 of this study that aims to define optimal data collection strategies using observation system simulation experiments.

  9. Women at Sea: modesty, privacy, and sexual misconduct of passengers and sailors aboard Islamic ships

    Directory of Open Access Journals (Sweden)

    Khalilieh, Hassan S.

    2006-06-01

    Full Text Available The article deals with the attitude of Islamic law towards the carriage of women by water and how Muslim judicial authorities viewed their presence on ships. It discusses the conditions under which women were carried, accommodated and treated, in addition to their personal and social behavior in ships. To apply Islamic religious ethics and navigational regulations during maritime journeys, jurists instructed owners of ships, crews, and passengers how to act in the event of an immoral behavior on the part of both or either party. Women could protect themselves against temptation and sexual harassment by dressing modestly, behaving properly, and traveling with mahrams. Even though this work focuses on the Islamic Mediterranean, the article briefly describes the punishment of sexual misconduct as established in the thirteenth century C.E. in Islamic Malay. Lastly, it touches the Islamic legal position on the transportation of Muslims aboard Christian ships.

    Este artículo trata de la actitud de la ley islámica acerca del transporte marítimo de las mujeres y de cómo las autoridades jurídicas musulmanas consideraban su presencia en los barcos. Discute las condiciones bajo las cuales las mujeres eran acomodadas y tratadas en los barcos así como el comportamiento personal y social que se esperaba de ellas. Con el fin de aplicar la ética islámica y las normas marítimas, los juristas informaban a los armadores, tripulaciones y pasajeros de cómo actuar en el caso de comportamiento inmoral por alguna o varias de las partes. El trabajo se centra en el Mediterráneo Islámico, pero trata brevemente el castigo de la conducta

  10. Peculiarities of lens and tail regeneration detected in newts after spaceflight aboard Foton M3

    Science.gov (United States)

    Grigoryan, Eleonora N.; Almeida, Eduardo; Poplinskaya, Valentina; Novikova, Julia; Domaratskaya, Elena; Aleinikova, Karina; Souza, Kenneth; Skidmore, Mike; Grigoryan, Eleonora N.

    In September 2007 the joint, 12 day long experiment was carried out aboard Russian satellite Foton M3. The goal of the experiment was to study eye lens, tail and forelimb toe regeneration in adult 16 newts (Pl. waltl.) operated 10 days before taking-off. In spaceflight and synchronous ground control we used video recording, temperature and irradiation control, as well as constant availability of thymidine analog BrdU for its absorption via animals' skin. New techniques allowed us to analyze animals' behavior in hyperand microgravity periods of time, to take proper account of spaceflight factors, and measure accumulated pools of DNA-synthesizing cells in regenerating tissues. All tissue specimens obtained from animals were isolated in the day of landing and then prepared for morphological, immunochemical and molecular investigations. Synchronous control was shifted for two days and reproduced flight conditions except changes of gravity influence. As a result in flown animals as compared with synchronous ground control we found lens regeneration of 0.5-1 stage speeded up and an increased BrdU+ (S-phase) cell number in eye cornea, growth zone, limbus and newly forming lens. These features of regeneration were accompanied by an increase of FGF2 expression in eye growth zone and heat shock protein (HSP90) induction purely in retinal macroglial cells of regenerating eyes. Toe regeneration rate was equal and achieved the stage of accomplished healing of amputation area in both groups - "flown" and control animals. We found no essential differences in tail regeneration rate and tail regenerate sizes in the newts exposed to space and on ground. In both groups tail regeneration reached the stage IV-V when tail length and square were around 4.4 mm and 15.5 mm2, correspondingly. However we did observe remarkable changes of tail regenerate form and some of pigmentation. Computer morphometrical analysis showed that only in ground control animals the evident dorso

  11. Charged particle accelerator

    International Nuclear Information System (INIS)

    Arakawa, Kazuo.

    1969-01-01

    An accelerator is disclosed having a device which permits the electrodes of an accelerator tube to be readily conditioned in an uncomplicated manner before commencing operation. In particle accelerators, it is necessary to condition the accelerator electrodes before a stable high voltage can be applied. Large current accelerators of the cockcroft-walton type require a complicated manual operation which entails applying to the electrodes a low voltage which is gradually increased to induce a vacuum discharge and then terminated. When the discharge attains an extremely low level, the voltage is again impressed and again raised to a high value in low current type accelerators, a high voltage power supply charges the electrodes once to induce discharge followed by reapplying the voltage when the vacuum discharge reaches a low level, according to which high voltage is automatically applied. This procedure, however, requires that the high voltage power supply be provided with a large internal resistance to limit the current to within several milliamps. The present invention connects a high voltage power supply and an accelerator tube through a discharge current limiting resistor wired in parallel with a switch. Initially, the switch is opened enabling the power supply to impress a voltage limited to a prescribed value by a suitably chosen resistor. Conditioning is effected by allowing the voltage between electrodes to increase and is followed by closing the switch through which high voltage is applied directly to the accelerator for operation. (K.J. Owens)

  12. Particle hygroscopicity during atmospheric new particle formation events: implications for the chemical species contributing to particle growth

    Directory of Open Access Journals (Sweden)

    Z. Wu

    2013-07-01

    Full Text Available This study examines the hygroscopicity of newly formed particles (diameters range 25–45 nm during two atmospheric new particle formation (NPF events in the German mid-level mountains during the Hill Cap Cloud Thuringia 2010 (HCCT-2010 field experiment. At the end of the NPF event involving clear particle growth, we measured an unusually high soluble particle fraction of 58.5% at 45 nm particle size. The particle growth rate contributed through sulfuric acid condensation only accounts for around 6.5% of the observed growth rate. Estimations showed that sulfuric acid condensation explained, however, only around 10% of that soluble particle fraction. Therefore, the formation of additional water-soluble matter appears imperative to explain the missing soluble fraction. Although direct evidence is missing, we consider water-soluble organics as candidates for this mechanism. For the case with clear growth process, the particle growth rate was determined by two alternative methods based on tracking the mode diameter of the nucleation mode. The mean particle growth rate obtained from the inter-site data comparison using Lagrangian consideration is 3.8 (± 2.6 nm h−1. During the same period, the growth rate calculated based on one site data is 5.0 nm h−1 using log-normal distribution function method. In light of the fact that considerable uncertainties could be involved in both methods, we consider both estimated growth rates consistent.

  13. A densitometric analysis of IIaO film flown aboard the space shuttle transportation system STS #3, 7, and 8

    Science.gov (United States)

    Hammond, Ernest C., Jr.

    1989-01-01

    Since the United States of America is moving into an age of reusable space vehicles, both electronic and photographic materials will continue to be an integral part of the recording techniques available. Film as a scientifically viable recording technique in astronomy is well documented. There is a real need to expose various types of films to the Shuttle environment. Thus, the main objective was to look at the subtle densitometric changes of canisters of IIaO film that was placed aboard the Space Shuttle 3 (STS-3).

  14. HAMLET -Matroshka IIA and IIB experiments aboard the ISS: comparison of organ doses

    Science.gov (United States)

    Kato, Zoltan; Reitz, Guenther; Berger, Thomas; Bilski, Pawel; Hajek, Michael; Sihver, Lembit; Palfalvi, Jozsef K.; Hager, Luke; Burmeister, Soenke

    The Matroshka experiments and the related FP7 HAMLET project aimed to study the dose burden of the cosmic rays in the organs of the crew working inside and outside the ISS. Two of the experiments will be discussed. They were performed in two different locations inside the ISS: during the Matroshka 2A (in 2006) the phantom was stored in the Russian Docking Module (Pirs), while during the Matroshka 2B (in 2007-08) it was inside the Russian Service Module (Zvezda). Both experiments were performed in the decreasing phase of the solar cycle. Solid state nuclear track detectors (SSNTD) were applied to investigate the dose contribution of the high LET radiation above ˜10 keV/µm. Two configurations of SSNTDs stacks were constructed: one for the exposure in the so called organ dose boxes (in the lung and kidney), another one for the skin dose measurements, embedded in the nomex poncho of the Phantom. In addition a reference package was placed outside the phantom. After exposure the detectors were transferred to the Earth for data evaluation. Short and long etching procedures were applied to distinguish the high and low LET particles, respectively. The particle tracks were evaluated by a semi automated image analyzer. Addi-tionally manual track parameter measurements were performed on very long tracks. As the result of measurements the LET spectra were deduced. Based on these spectra, the absorbed dose, the dose equivalent and the mean quality factor were calculated. The configuration of the stacks, the methods of the calibration and evaluation and finally the results will be presented and compared. The multiple etching and the combined evaluation method allowed to determine the fraction of the dose originated from HZE particles (Z>2 and range > major axis). Further on, data eval-uation was performed to separate the secondary particles (target fragments) from the primary particles. Although the number of high LET particles above a ˜80 keV/µm was found to be higher during

  15. Particle transport in 3He-rich events: wave-particle interactions and particle anisotropy measurements

    Directory of Open Access Journals (Sweden)

    B. T. Tsurutani

    2002-04-01

    Full Text Available Energetic particles and MHD waves are studied using simultaneous ISEE-3 data to investigate particle propagation and scattering between the source near the Sun and 1 AU. 3 He-rich events are of particular interest because they are typically low intensity "scatter-free" events. The largest solar proton events are of interest because they have been postulated to generate their own waves through beam instabilities. For 3 He-rich events, simultaneous interplanetary magnetic spectra are measured. The intensity of the interplanetary "fossil" turbulence through which the particles have traversed is found to be at the "quiet" to "intermediate" level of IMF activity. Pitch angle scattering rates and the corresponding particle mean free paths lW - P are calculated using the measured wave intensities, polarizations, and k directions. The values of lW - P are found to be ~ 5 times less than the value of lHe , the latter derived from He intensity and anisotropy time profiles. It is demonstrated by computer simulation that scattering rates through a 90° pitch angle are lower than that of other pitch angles, and that this is a possible explanation for the discrepancy between the lW - P and lHe values. At this time the scattering mechanism(s is unknown. We suggest a means where a direct comparison between the two l values could be made. Computer simulations indicate that although scattering through 90° is lower, it still occurs. Possibilities are either large pitch angle scattering through resonant interactions, or particle mirroring off of field compression regions. The largest solar proton events are analyzed to investigate the possibilities of local wave generation at 1 AU. In accordance with the results of a previous calculation (Gary et al., 1985 of beam stability, proton beams at 1 AU are found to be marginally stable. No evidence for substantial wave amplitude was found. Locally generated waves, if present, were less than 10-3 nT 2 Hz-1 at the leading

  16. Particle transport in 3He-rich events: wave-particle interactions and particle anisotropy measurements

    Directory of Open Access Journals (Sweden)

    T. Hada

    Full Text Available Energetic particles and MHD waves are studied using simultaneous ISEE-3 data to investigate particle propagation and scattering between the source near the Sun and 1 AU. 3 He-rich events are of particular interest because they are typically low intensity "scatter-free" events. The largest solar proton events are of interest because they have been postulated to generate their own waves through beam instabilities. For 3 He-rich events, simultaneous interplanetary magnetic spectra are measured. The intensity of the interplanetary "fossil" turbulence through which the particles have traversed is found to be at the "quiet" to "intermediate" level of IMF activity. Pitch angle scattering rates and the corresponding particle mean free paths lW - P are calculated using the measured wave intensities, polarizations, and k directions. The values of lW - P are found to be ~ 5 times less than the value of lHe , the latter derived from He intensity and anisotropy time profiles. It is demonstrated by computer simulation that scattering rates through a 90° pitch angle are lower than that of other pitch angles, and that this is a possible explanation for the discrepancy between the lW - P and lHe values. At this time the scattering mechanism(s is unknown. We suggest a means where a direct comparison between the two l values could be made. Computer simulations indicate that although scattering through 90° is lower, it still occurs. Possibilities are either large pitch angle scattering through resonant interactions, or particle mirroring off of field compression regions. The largest solar proton events are analyzed to investigate the possibilities of local wave generation at 1 AU. In accordance with the results of a previous calculation (Gary et al., 1985 of beam stability, proton beams at 1 AU are found to be marginally stable. No evidence for substantial wave amplitude was found. Locally generated waves, if present, were less than 10-3 nT 2 Hz-1 at the leading

  17. Particles and nuclei in PANIC

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-07-15

    PANIC is the triennal International Conference on Particles and Nuclei, and judging from the latest PANIC, held in Kyoto from 20-24 April there is no need for panic yet. Faced with two pictures – one of nuclei described in nucleon and meson terms, and another of nucleons containing quarks and gluons – physicists are intrigued to know what new insights from the quark level can tell us about nuclear physics, or vice versa.

  18. Particle production at AGS energies

    International Nuclear Information System (INIS)

    Steadman, S.G.; Rothschild, P.J.; Sung, T.W.; Zachary, D.

    1995-01-01

    The authors discuss particle production from 14.6 A·GeV/c Si and 11.6 A·GeV/c Au projectiles on Al and Au targets. The second-level trigger utilized by E859 allows high precision measurements of K - , bar p, Λ and bar Λ. The bar Λ yield is larger than expected, and a surprisingly large fraction of the bar p's are observed to arise from the decay of bar Λ

  19. Particles and nuclei in PANIC

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    PANIC is the triennal International Conference on Particles and Nuclei, and judging from the latest PANIC, held in Kyoto from 20-24 April there is no need for panic yet. Faced with two pictures – one of nuclei described in nucleon and meson terms, and another of nucleons containing quarks and gluons – physicists are intrigued to know what new insights from the quark level can tell us about nuclear physics, or vice versa

  20. Lecture II. Charmed particle spectroscopy

    International Nuclear Information System (INIS)

    Anon.

    1978-01-01

    The discussion of charmed particle spectroscopy covers the particle properties and interrelations from a charmed quark composition point of view including SU(4)-symmetry generalities, mesons, baryons, charmed particle masses, and decays of charmed particles. 6 references

  1. Solar energetic particle anisotropies and insights into particle transport

    Energy Technology Data Exchange (ETDEWEB)

    Leske, R. A., E-mail: ral@srl.caltech.edu; Cummings, A. C.; Cohen, C. M. S.; Mewaldt, R. A.; Labrador, A. W.; Stone, E. C. [California Institute of Technology, Pasadena, CA 91125 (United States); Wiedenbeck, M. E. [Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA 91109 (United States); Christian, E. R.; Rosenvinge, T. T. von [NASA/Goddard Space Flight Center, Greenbelt, MD 20771 (United States)

    2016-03-25

    As solar energetic particles (SEPs) travel through interplanetary space, their pitch-angle distributions are shaped by the competing effects of magnetic focusing and scattering. Measurements of SEP anisotropies can therefore reveal information about interplanetary conditions such as magnetic field strength, topology, and turbulence levels at remote locations from the observer. Onboard each of the two STEREO spacecraft, the Low Energy Telescope (LET) measures pitch-angle distributions for protons and heavier ions up to iron at energies of about 2-12 MeV/nucleon. Anisotropies observed using LET include bidirectional flows within interplanetary coronal mass ejections, sunward-flowing particles when STEREO was magnetically connected to the back side of a shock, and loss-cone distributions in which particles with large pitch angles underwent magnetic mirroring at an interplanetary field enhancement that was too weak to reflect particles with the smallest pitch angles. Unusual oscillations in the width of a beamed distribution at the onset of the 23 July 2012 SEP event were also observed and remain puzzling. We report LET anisotropy observations at both STEREO spacecraft and discuss their implications for SEP transport, focusing exclusively on the extreme event of 23 July 2012 in which a large variety of anisotropies were present at various times during the event.

  2. Solar energetic particle anisotropies and insights into particle transport

    Science.gov (United States)

    Leske, R. A.; Cummings, A. C.; Cohen, C. M. S.; Mewaldt, R. A.; Labrador, A. W.; Stone, E. C.; Wiedenbeck, M. E.; Christian, E. R.; Rosenvinge, T. T. von

    2016-03-01

    As solar energetic particles (SEPs) travel through interplanetary space, their pitch-angle distributions are shaped by the competing effects of magnetic focusing and scattering. Measurements of SEP anisotropies can therefore reveal information about interplanetary conditions such as magnetic field strength, topology, and turbulence levels at remote locations from the observer. Onboard each of the two STEREO spacecraft, the Low Energy Telescope (LET) measures pitch-angle distributions for protons and heavier ions up to iron at energies of about 2-12 MeV/nucleon. Anisotropies observed using LET include bidirectional flows within interplanetary coronal mass ejections, sunward-flowing particles when STEREO was magnetically connected to the back side of a shock, and loss-cone distributions in which particles with large pitch angles underwent magnetic mirroring at an interplanetary field enhancement that was too weak to reflect particles with the smallest pitch angles. Unusual oscillations in the width of a beamed distribution at the onset of the 23 July 2012 SEP event were also observed and remain puzzling. We report LET anisotropy observations at both STEREO spacecraft and discuss their implications for SEP transport, focusing exclusively on the extreme event of 23 July 2012 in which a large variety of anisotropies were present at various times during the event.

  3. Galaxy bispectrum from massive spinning particles

    Science.gov (United States)

    Moradinezhad Dizgah, Azadeh; Lee, Hayden; Muñoz, Julian B.; Dvorkin, Cora

    2018-05-01

    Massive spinning particles, if present during inflation, lead to a distinctive bispectrum of primordial perturbations, the shape and amplitude of which depend on the masses and spins of the extra particles. This signal, in turn, leaves an imprint in the statistical distribution of galaxies; in particular, as a non-vanishing galaxy bispectrum, which can be used to probe the masses and spins of these particles. In this paper, we present for the first time a new theoretical template for the bispectrum generated by massive spinning particles, valid for a general triangle configuration. We then proceed to perform a Fisher-matrix forecast to assess the potential of two next-generation spectroscopic galaxy surveys, EUCLID and DESI, to constrain the primordial non-Gaussianity sourced by these extra particles. We model the galaxy bispectrum using tree-level perturbation theory, accounting for redshift-space distortions and the Alcock-Paczynski effect, and forecast constraints on the primordial non-Gaussianity parameters marginalizing over all relevant biases and cosmological parameters. Our results suggest that these surveys would potentially be sensitive to any primordial non-Gaussianity with an amplitude larger than fNL≈ 1, for massive particles with spins 2, 3, and 4. Interestingly, if non-Gaussianities are present at that level, these surveys will be able to infer the masses of these spinning particles to within tens of percent. If detected, this would provide a very clear window into the particle content of our Universe during inflation.

  4. Methods for forming particles

    Science.gov (United States)

    Fox, Robert V.; Zhang, Fengyan; Rodriguez, Rene G.; Pak, Joshua J.; Sun, Chivin

    2016-06-21

    Single source precursors or pre-copolymers of single source precursors are subjected to microwave radiation to form particles of a I-III-VI.sub.2 material. Such particles may be formed in a wurtzite phase and may be converted to a chalcopyrite phase by, for example, exposure to heat. The particles in the wurtzite phase may have a substantially hexagonal shape that enables stacking into ordered layers. The particles in the wurtzite phase may be mixed with particles in the chalcopyrite phase (i.e., chalcopyrite nanoparticles) that may fill voids within the ordered layers of the particles in the wurtzite phase thus produce films with good coverage. In some embodiments, the methods are used to form layers of semiconductor materials comprising a I-III-VI.sub.2 material. Devices such as, for example, thin-film solar cells may be fabricated using such methods.

  5. LHCb unveils new particles

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

    The LHCb collaboration announces the observation of four “exotic” particles from its analysis of the LHC data.   The LHCb experimental cavern. On 28 June, the LHCb collaboration reported the observation of three new "exotic" particles and confirmation of the existence of a fourth one in data from the LHC. These particles each appear to be formed by four quarks (the fundamental constituents of the matter inside all the atoms of the universe): two quarks and two antiquarks (that is, a tetraquark). Due to their non-standard quark content, the newly observed particles have been included in the broad category of so-called exotic particles, although their exact theoretical interpretation is still under study.            The quark model, proposed by Murray Gell-Mann and George Zweig in 1964, is considered to be the most valid scheme for the classification of hadrons (all the composite particles) that has been fou...

  6. Particle Swarm Optimization

    Science.gov (United States)

    Venter, Gerhard; Sobieszczanski-Sobieski Jaroslaw

    2002-01-01

    The purpose of this paper is to show how the search algorithm known as particle swarm optimization performs. Here, particle swarm optimization is applied to structural design problems, but the method has a much wider range of possible applications. The paper's new contributions are improvements to the particle swarm optimization algorithm and conclusions and recommendations as to the utility of the algorithm, Results of numerical experiments for both continuous and discrete applications are presented in the paper. The results indicate that the particle swarm optimization algorithm does locate the constrained minimum design in continuous applications with very good precision, albeit at a much higher computational cost than that of a typical gradient based optimizer. However, the true potential of particle swarm optimization is primarily in applications with discrete and/or discontinuous functions and variables. Additionally, particle swarm optimization has the potential of efficient computation with very large numbers of concurrently operating processors.

  7. Music of elementary particles

    International Nuclear Information System (INIS)

    Sternheimer, J.

    1983-01-01

    This Note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter [fr

  8. Low energy particle composition

    International Nuclear Information System (INIS)

    Gloeckler, G.

    1975-01-01

    More than 50 papers presented at this Conference dealt with the composition of low energy particles. The topics can be divided roughly into two broad categories. The first is the study of the energy spectra and composition of the steady or 'quiet-time' particle flux, whose origin is at this time unknown. The second category includes the study of particles and photons which are associated with solar flares or active regions on the sun. (orig.) [de

  9. Music of elementary particles

    Energy Technology Data Exchange (ETDEWEB)

    Sternheimer, J.

    1983-12-12

    This note offers a new point of view on particle masses. It is shown that they are distributed following a musical scale, the chromatic tempered scale -for stable particles- subdivided into microintervals including unstable particles. A theoretical explanation, based on causality, allows one also to calculate their global distribution along the mass scale, in agreement with experiment, and indicating the existence of ''musical'' laws in the vibratory organisation of matter.

  10. Review of particle properties

    International Nuclear Information System (INIS)

    Bricman, C.; Dionisi, C.; Hemingway, R.J.; Mazzucato, M.; Montanet, L.; Barash-Schmidt, N.; Crawford, R.C.; Roos, M.; Barbaro-Galtieri, A.; Horne, C.P.; Kelly, R.L.; Losty, M.J.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Armstrong, B.

    1978-01-01

    This review of the properties of leptons, mesons, and baryons is an updating of Review of Particle Properties, Particle Data Group [Rev. Mod. Phys. 48 (1976) No. 2, Part II; and Supplement, Phys. Lett. 68B (1977) 1]. Data are evaluated, listed, averaged, and summarized in tables. Numerous tables, figures, and formulae of interest to particle physicists are also included. A data booklet is available. (Auth.)

  11. Condensed elementary particle matter

    International Nuclear Information System (INIS)

    Kajantie, K.

    1996-01-01

    Quark matter is a special case of condensed elementary particle matter, matter governed by the laws of particle physics. The talk discusses how far one can get in the study of particle matter by reducing the problem to computations based on the action. As an example the computation of the phase diagram of electroweak matter is presented. It is quite possible that ultimately an antireductionist attitude will prevail: experiments will reveal unpredicted phenomena not obviously reducible to the study of the action. (orig.)

  12. Particle correlations at ALICE

    Energy Technology Data Exchange (ETDEWEB)

    Erazmus, B.; Lednicky, R.; Lyuboshitz, V.; Martin, L.; Mikhailov, K.; Pluta, J.; Sinyukov, Yu.; Stavinsky, A.; Werner, K

    1998-12-31

    The ability of the ALICE detector for determination of the space-time characteristics of particle production in heavy-ion collisions at LHC from measurements of the correlation functions of identical and non-identical particles at small relative velocities is discussed. The possibility to use the correlations of non-identical particles for a direct determination of the delays in emission of various particle species at time scales as small as 10{sup -23} s is demonstrated. The influence of the multi-boson effects on pion multiplicities, single-pion spectra and two-pion correlation functions is discussed. (author) 63 refs.

  13. Particle Correlations at LEP

    CERN Document Server

    Kress, Thomas

    2002-01-01

    Particle correlations are extensively studied to obtain information about the dynamics of hadron production. From 1989 to 2000 the four LEP collaborations recorded more than 16 million hadronic Z0 decays and several thousand W+W- events. In Z0 decays, two-particle correlations were analysed in detail to study Bose-Einstein and Fermi-Dirac correlations for various particle species. In fully-hadronic W+W- decays, particle correlations were used to study whether the two W bosons decay independently. A review of selected results is presented.

  14. Particle Image Velocimetry

    DEFF Research Database (Denmark)

    Zhang, Chen; Vasilevskis, Sandijs; Kozlowski, Bartosz

    Particle image velocimetry (PIV) is a non-intrusive, whole filed optical method providing instantaneous velocity information in fluids. The flow is seeded with tracer particles. The particles are illuminated in the target area with a light sheet at least twice within a short time interval....... The camera images the target area and captures each light pulse in separate image frames. The displacement of the particle between the light pulses can be used to determine the velocity vectors. This guideline introduces the principle of the PIV system and the system configuration. The measurement procedure...

  15. Review of particle properties

    International Nuclear Information System (INIS)

    Hikasa, K.; Hagiwara, K.; Kawabata, S.; Barnett, R.M.; Groom, D.E.; Trippe, T.G.; Wohl, C.G.; Yost, G.P.; Armstrong, B. Technical Associate; Wagman, G.S. Technical Associate; Stone, J.; Porter, F.C.; Morrison, R.J.; Cutkosky, R.E.; Montanet, L.; Gieselmann, K. Technical Associate; Aguilar-Benitez, M.; Caso, C.; Crawford, R.L.; Roos, M.; Toernqvist, N.A.; Hayes, K.G.; Hoehler, G.; Manley, D.M.

    1992-01-01

    In this Review, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We also summarize searches for hypothetical particles such as Higgs bosons, the top quark, heavy neutrinos, monopoles, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. A booklet is available containing the Summary Tables and abbreviated versions of some other sections of this full Review

  16. Elementary particle theory

    International Nuclear Information System (INIS)

    Marciano, W.J.

    1984-12-01

    The present state of the art in elementary particle theory is reviewed. Topics include quantum electrodynamics, weak interactions, electroweak unification, quantum chromodynamics, and grand unified theories. 113 references

  17. Particle physics experiments 1983

    International Nuclear Information System (INIS)

    Stuart, G.W.

    1983-01-01

    The report describes work carried out in 1983 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)

  18. Particle Physics & Astrophysics (PPA)

    Data.gov (United States)

    Federal Laboratory Consortium — Scientists at SLAC's Particle Physics and Astrophysics develop and utilize unique instruments from underground to outer space to explore the ultimate laws of nature...

  19. Particle Shape Anisotropy in Pickering Emulsions: Cubes and Peanuts

    NARCIS (Netherlands)

    de Folter, J.W.J.; Hutter, E.M.; Castillo, S.I.R.; Klop, K.E.; Philipse, A.P.; Kegel, W.K.

    2014-01-01

    We have investigated the effect of particle shape in Pickering emulsions by employing, for the first time, cubic and peanut-shaped particles. The interfacial packing and orientation of anisotropic microparticles are revealed at the single-particle level by direct microscopy observations. The uniform

  20. Particle bed reactor scaling relationships

    Science.gov (United States)

    Slovik, G.; Araj, K.; Horn, F. L.; Ludewig, H.; Benenati, R.

    The Particle Bed Reactor (PBR) concept can be used in several applications both as part of a power generating system or as a direct propulsion unit. In order to carry out optimization studies of systems involving a PBR, it is necessary to know the variation of the critical mass with pertinent system parameters such as weight, size, power level and thrust level. A parametric study is presented for all the practical combinations of fuel and moderating material. The PBR is described, the practical combinations of materials and dimensions are discussed, and an example is presented.

  1. Materials International Space Station Experiment (MISSE) 5 Developed to Test Advanced Solar Cell Technology Aboard the ISS

    Science.gov (United States)

    Wilt, David M.

    2004-01-01

    The testing of new technologies aboard the International Space Station (ISS) is facilitated through the use of a passive experiment container, or PEC, developed at the NASA Langley Research Center. The PEC is an aluminum suitcase approximately 2 ft square and 5 in. thick. Inside the PEC are mounted Materials International Space Station Experiment (MISSE) plates that contain the test articles. The PEC is carried to the ISS aboard the space shuttle or a Russian resupply vehicle, where astronauts attach it to a handrail on the outer surface of the ISS and deploy the PEC, which is to say the suitcase is opened 180 deg. Typically, the PEC is left in this position for approximately 1 year, at which point astronauts close the PEC and it is returned to Earth. In the past, the PECs have contained passive experiments, principally designed to characterize the durability of materials subjected to the ultraviolet radiation and atomic oxygen present at the ISS orbit. The MISSE5 experiment is intended to characterize state-of-art (SOA) and beyond photovoltaic technologies.

  2. Particle Swarm Optimisation with Spatial Particle Extension

    DEFF Research Database (Denmark)

    Krink, Thiemo; Vesterstrøm, Jakob Svaneborg; Riget, Jacques

    2002-01-01

    In this paper, we introduce spatial extension to particles in the PSO model in order to overcome premature convergence in iterative optimisation. The standard PSO and the new model (SEPSO) are compared w.r.t. performance on well-studied benchmark problems. We show that the SEPSO indeed managed...

  3. Violation of Particle Anti-particle Symmetry

    CERN Multimedia

    CERN. Geneva

    2001-01-01

    Symmetry is a fundamental concept which can be found in the whole range of human activities e. g. from arts to science. The beauty of a statues is often related to its symmetric form. In physics, all the laws are related to some sort of symmetry. Equally important is a small breakdown ofsymmetry. Even for the case of a statue, its beauty might be enhanced by introducing small distortions. In this course, we investigate the role symmetry in the world of elementary particles. Some symmetries found there are very similar to those which can be seen in our daily life, while others are more exotic and related to the quantum nature of the elementary particles. Our particular focus ismade on symmetry and its violation between the matter and anti-matter, known as CP violation. It is experimentally well established that particleand anti-particle behave a tiny bit differently in the world of elementary particles. We discuss how this would be explained and how we can extendour knowledge. Evolution of our universe is stro...

  4. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

    Allen, Rachel; MacVean, Lissa; Tse, Ian; Mazzaro, Laura; Stacey, Mark; Variano, Evan

    2014-11-01

    Particle settling velocities can be altered by turbulence. In turbulence, dense particles may get trapped in convergent flow regions, and falling particles may be swept towards the downward side of turbulent eddies, resulting in enhanced settling velocities. The degree of velocity enhancement may depend on the Stokes number, the Rouse number, and the turbulent Reynolds number. In a homogeneous, isotropic turbulence tank, we tested the effects of particle size and type, suspended sediment concentration, and level of turbulence on the settling velocities of particles typically found in muddy estuaries. Two Acoustic Doppler Velocimeters (ADVs), separated vertically, measured turbulent velocities and suspended sediment concentrations, which yield condition dependent settling velocities, via ∂/á C ñ ∂ t = -∂/∂ z (ws á C ñ + á w ' C ' ñ) . These results are pertinent to fine sediment transport in estuaries, where high concentrations of suspended material are transported and impacted by low energy turbulence.

  5. Entanglement of identical particles and the detection process

    DEFF Research Database (Denmark)

    Tichy, Malte C.; de Melo, Fernando; Kus, Marek

    2013-01-01

    We introduce detector-level entanglement, a unified entanglement concept for identical particles that takes into account the possible deletion of many-particle which-way information through the detection process. The concept implies a measure for the effective indistinguishability of the particles...... statistical behavior depends on their initial entanglement. Our results show that entanglement cannot be attributed to a state of identical particles alone, but that the detection process has to be incorporated in the analysis....

  6. Particle size determination

    International Nuclear Information System (INIS)

    Burr, K.J.

    1979-01-01

    A specification is given for an apparatus to provide a completely automatic testing cycle to determine the proportion of particles of less than a predetermined size in one of a number of fluid suspensions. Monitoring of the particle concentration during part of the process can be carried out by an x-ray source and detector. (U.K.)

  7. Elementary particle theory

    CERN Document Server

    Stefanovich, Eugene

    2018-01-01

    This book introduces notation, terminology, and basic ideas of relativistic quantum theories. The discussion proceeds systematically from the principle of relativity and postulates of quantum logics to the construction of Poincaré invariant few-particle models of interaction and scattering. It is the first of three volumes formulating a consistent relativistic quantum theory of interacting charged particles.

  8. History of Particle Physics

    Science.gov (United States)

    back to history page Back Particle Physics Timeline For over two thousand years people have thought the Standard Model. We invite you to explore this history of particle physics with a focus on the : Quantum Theory 1964 - Present: The Modern View (the Standard Model) back to history page Back Sections of

  9. Light particles in turbulence

    NARCIS (Netherlands)

    Nagendra Prakash, Vivek

    2013-01-01

    This thesis deals with the broad topic of particles in turbulence, which has applications in a diverse number of fields. A vast majority of fluid flows found in nature and in the industry are turbulent and contain dispersed elements. In this thesis, I have focused on light particles (air bubbles in

  10. Particle physics instrumentation

    International Nuclear Information System (INIS)

    Riegler, W.

    2011-01-01

    This report summarizes a series of three lectures aimed at giving an overview of basic particle detection principles, the interaction of particles with matter, the application of these principles in modern detector systems, as well techniques to read out detector signals in high-rate experiments. (author)

  11. Particles, contacts, bulk behavior

    NARCIS (Netherlands)

    Luding, Stefan; Tomas, J.

    2014-01-01

    Granular matter consists of discrete “particles”. These can be separate sand-grains, agglomerates (made of many primary particles), or solid materials like rock, composites, or metal-alloys—all with particulate inhomogeneous, possibly anisotropic micro-structure. Particles can be as small as

  12. Particle Astrophysics of Neutrinos

    Indian Academy of Sciences (India)

    Amol Dighe

    Energy spectra of neutrino sources. ASPERA. Page 4. Some unique features of neutrinos. The second most abundant particles in the universe. Cosmic microwave background photons: 400 / cm3. Cosmic background neutrinos: 330 / cm3. The lightest massive particles. A million times lighter than the electron. No direct mass ...

  13. Astro-particle-physics

    International Nuclear Information System (INIS)

    Salam, A.

    1985-09-01

    Opening remarks at the Fourth Marcel Grossman Meeting, 17-21 June 1985, in Rome, Italy, are reported. The meeting was concerned with the symbiosis of cosmology and particle physics. Numerous connections between work in particle physics and cosmology, in both experimental and theoretical areas, are pointed out

  14. When is a particle

    International Nuclear Information System (INIS)

    Drell, S.D.

    1978-01-01

    The concept of elementary constituents or ultimate building blocks of nature in recent years is reviewed. The quark hypothesis, neutrinos, color, hard collisions, psi and other recent resonances, flavor, quantum chromodynamics, the tau particle, and particle structure are among the ideas considered. 22 references

  15. Concepts of particle physics

    International Nuclear Information System (INIS)

    Gottfried, K.; Weisskopf, V.F.

    1984-01-01

    This volume elucidates basic and well-established concepts of particle physics for the autodidact who is curious about recent developments in fundamental physics. Elementary quantum mechanics is a background must. Contents, abridged: The evolution of the particle concept before the advent of quantum mechanics. Nonrelativistic quantum mechanics and atomic physics. Relativistic quantum theory. Nuclear phenomena. Subnuclear phenomena. Index

  16. RESEARCH IN PARTICLE PHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Kearns, Edward [Boston Universiy

    2013-07-12

    This is the final report for the Department of Energy Grant to Principal Investigators in Experimental and Theoretical Particle Physics at Boston University. The research performed was in the Energy Frontier at the LHC, the Intensity Frontier at Super-Kamiokande and T2K, the Cosmic Frontier and detector R&D in dark matter detector development, and in particle theory.

  17. Optics of charged particles

    International Nuclear Information System (INIS)

    Wollnik, H.

    1987-01-01

    Suitable for both the specialist and non-specialist, this book develops all statements from first principles. Key chapters of the book focus upon how to design particle-optical systems, the systematics of image abberations, the effects of fringing fields, systematics of beams, and solutions for particle-optical systems. An undergraduate background in physics and mathematics is required for this work

  18. Microchip Coulter particle counter

    DEFF Research Database (Denmark)

    Larsen, Ulrik Darling; Blankenstein, Gert; Branebjerg, J.

    1997-01-01

    This paper presents a micro device employing the Coulter principle for counting and sizing of living cells and particles in liquid suspension. The microchip Coulter particle counter (μCPC) has been employed in a planar silicon structure covered with glass, which enables detailed observation during...

  19. Interactive Terascale Particle Visualization

    Science.gov (United States)

    Ellsworth, David; Green, Bryan; Moran, Patrick

    2004-01-01

    This paper describes the methods used to produce an interactive visualization of a 2 TB computational fluid dynamics (CFD) data set using particle tracing (streaklines). We use the method introduced by Bruckschen et al. [2001] that pre-computes a large number of particles, stores them on disk using a space-filling curve ordering that minimizes seeks, and then retrieves and displays the particles according to the user's command. We describe how the particle computation can be performed using a PC cluster, how the algorithm can be adapted to work with a multi-block curvilinear mesh, and how the out-of-core visualization can be scaled to 296 billion particles while still achieving interactive performance on PG hardware. Compared to the earlier work, our data set size and total number of particles are an order of magnitude larger. We also describe a new compression technique that allows the lossless compression of the particles by 41% and speeds the particle retrieval by about 30%.

  20. Particles, imaging and nuclei

    International Nuclear Information System (INIS)

    Harris, J.

    1986-01-01

    The book on particles, imaging and nuclei is one of the Background Readers for the Revised Nuffield Advanced Physics course. The contents contain five educational articles, which extend concepts covered in the course and examine recent developments in physics. Four of the articles on:- particles and the forces of nature, radioisotopes, lasers probe the atomic nucleus, and nuclear history, are indexed separately. (UK)

  1. Particle processing technology

    Science.gov (United States)

    Sakka, Yoshio

    2014-02-01

    In recent years, there has been strong demand for the development of novel devices and equipment that support advanced industries including IT/semiconductors, the environment, energy and aerospace along with the achievement of higher efficiency and reduced environmental impact. Many studies have been conducted on the fabrication of innovative inorganic materials with novel individual properties and/or multifunctional properties including electrical, dielectric, thermal, optical, chemical and mechanical properties through the development of particle processing. The fundamental technologies that are key to realizing such materials are (i) the synthesis of nanoparticles with uniform composition and controlled crystallite size, (ii) the arrangement/assembly and controlled dispersion of nanoparticles with controlled particle size, (iii) the precise structural control at all levels from micrometer to nanometer order and (iv) the nanostructural design based on theoretical/experimental studies of the correlation between the local structure and the functions of interest. In particular, it is now understood that the application of an external stimulus, such as magnetic energy, electrical energy and/or stress, to a reaction field is effective in realizing advanced particle processing [1-3]. This special issue comprises 12 papers including three review papers. Among them, seven papers are concerned with phosphor particles, such as silicon, metals, Si3N4-related nitrides, rare-earth oxides, garnet oxides, rare-earth sulfur oxides and rare-earth hydroxides. In these papers, the effects of particle size, morphology, dispersion, surface states, dopant concentration and other factors on the optical properties of phosphor particles and their applications are discussed. These nanoparticles are classified as zero-dimensional materials. Carbon nanotubes (CNT) and graphene are well-known one-dimensional (1D) and two-dimensional (2D) materials, respectively. This special issue also

  2. UARS PEM Level 2 MEPS V001

    Data.gov (United States)

    National Aeronautics and Space Administration — The Particle Environment Monitor (PEM) level 2 Medium-Energy Particle Spectrometer (MEPS) daily product contains the electron and proton high-resolution spectral...

  3. Compact particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Elizondo-Decanini, Juan M.

    2017-08-29

    A compact particle accelerator having an input portion configured to receive power to produce particles for acceleration, where the input portion includes a switch, is provided. In a general embodiment, a vacuum tube receives particles produced from the input portion at a first end, and a plurality of wafer stacks are positioned serially along the vacuum tube. Each of the plurality of wafer stacks include a dielectric and metal-oxide pair, wherein each of the plurality of wafer stacks further accelerate the particles in the vacuum tube. A beam shaper coupled to a second end of the vacuum tube shapes the particles accelerated by the plurality of wafer stacks into a beam and an output portion outputs the beam.

  4. DEM Particle Fracture Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Boning [Univ. of Colorado, Boulder, CO (United States); Herbold, Eric B. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Homel, Michael A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Regueiro, Richard A. [Univ. of Colorado, Boulder, CO (United States)

    2015-12-01

    An adaptive particle fracture model in poly-ellipsoidal Discrete Element Method is developed. The poly-ellipsoidal particle will break into several sub-poly-ellipsoids by Hoek-Brown fracture criterion based on continuum stress and the maximum tensile stress in contacts. Also Weibull theory is introduced to consider the statistics and size effects on particle strength. Finally, high strain-rate split Hopkinson pressure bar experiment of silica sand is simulated using this newly developed model. Comparisons with experiments show that our particle fracture model can capture the mechanical behavior of this experiment very well, both in stress-strain response and particle size redistribution. The effects of density and packings o the samples are also studied in numerical examples.

  5. Particle-assisted wetting

    International Nuclear Information System (INIS)

    Xu Hui; Yan Feng; Tierno, Pietro; Marczewski, Dawid; Goedel, Werner A

    2005-01-01

    Wetting of a solid surface by a liquid is dramatically impeded if either the solid or the liquid is decorated by particles. Here it is shown that in the case of contact between two liquids the opposite effect may occur; mixtures of a hydrophobic liquid and suitable particles form wetting layers on a water surface though the liquid alone is non-wetting. In these wetting layers, the particles adsorb to, and partially penetrate through, the liquid/air and/or the liquid/water interface. This formation of wetting layers can be explained by the reduction in total interfacial energy due to the replacement of part of the fluid/fluid interfaces by the particles. It is most prominent if the contact angles at the fluid/fluid/particle contact lines are close to 90 0

  6. Simultaneous observations of E- and B-ULF waves aboard a sounding rocket payload

    International Nuclear Information System (INIS)

    Kloecker, N.; Luehr, H.; Grabowski, R.

    1980-01-01

    Magnetic and electric field variations in the frequency range of 0.5 to 4 Hz were made on a payload flown within the IMS sounding rocket campaign 'Substormphenomena'. The payload was launched into an auroral break-up. The waves show amplitudes up to 100 nT in B and 100 mV/m in E. Mutual correlation of B and E as well as correlation with electron precipitation are observed. The energy flux of the waves and the particles are equally directed and of the same order of magnitude. (Auth.)

  7. Measurement of charge and energy spectra of heavy nuclei aboard Cosmos-936 artificial Earth satellite

    International Nuclear Information System (INIS)

    Dashin, S.A.; Marennyy, A.M.; Gertsen, G.P.

    1982-07-01

    Charge and energy spectra of heavy charged particles were measured. Measurements were performed by a package of dielectric track detectors mounted behind the shield of 60-80 kg m to the minus second power thick. The charge of nuclei was determined from the complete track length. A group of 1915 tracks of nuclei with Z 6 in the energy range 100-450 MeV/nuclon were identified. The differential charge spectrum of nuclei with 6 Z 28 and the energy spectrum of nuclei of the iron group were built

  8. Examining Model Atmospheric Particles Inside and Out

    Science.gov (United States)

    Wingen, L. M.; Zhao, Y.; Fairhurst, M. C.; Perraud, V. M.; Ezell, M. J.; Finlayson-Pitts, B. J.

    2017-12-01

    Atmospheric particles scatter incoming solar radiation and act as cloud condensation nuclei (CCN), thereby directly and indirectly affecting the earth's radiative balance and reducing visibility. These atmospheric particles may not be uniform in composition. Differences in the composition of a particle's outer surface from its core can arise during particle growth, (photo)chemical aging, and exchange of species with the gas phase. The nature of the surface on a molecular level is expected to impact growth mechanisms as well as their ability to act as CCN. Model laboratory particle systems are explored using direct analysis in real time-mass spectrometry (DART-MS), which is sensitive to surface composition, and contrasted with average composition measurements using high resolution, time-of-flight aerosol mass spectrometry (HR-ToF-AMS). Results include studies of the heterogeneous reactions of amines with solid dicarboxylic acid particles, which are shown to generate aminium dicarboxylate salts at the particle surface, leaving an unreacted core. Combination of both mass spectrometric techniques reveals a trend in reactivity of C3-C7 dicarboxylic acids with amines and allows calculation of the DART probe depth into the particles. The results of studies on additional model systems that are currently being explored will also be reported.

  9. Discrete element method modeling of the triboelectric charging of polyethylene particles: Can particle size distribution and segregation reduce the charging?

    International Nuclear Information System (INIS)

    Konopka, Ladislav; Kosek, Juraj

    2015-01-01

    Polyethylene particles of various sizes are present in industrial gas-dispersion reactors and downstream processing units. The contact of the particles with a device wall as well as the mutual particle collisions cause electrons on the particle surface to redistribute in the system. The undesirable triboelectric charging results in several operational problems and safety risks in industrial systems, for example in the fluidized-bed polymerization reactor. We studied the charging of polyethylene particles caused by the particle-particle interactions in gas. Our model employs the Discrete Element Method (DEM) describing the particle dynamics and incorporates the ‘Trapped Electron Approach’ as the physical basis for the considered charging mechanism. The model predicts the particle charge distribution for systems with various particle size distributions and various level of segregation. Simulation results are in a qualitative agreement with experimental observations of similar particulate systems specifically in two aspects: 1) Big particles tend to gain positive charge and small particles the negative one. 2) The wider the particle size distribution is, the more pronounced is the charging process. Our results suggest that not only the size distribution, but also the effect of the spatial segregation of the polyethylene particles significantly influence the resulting charge distribution ‘generated’ in the system. The level of particle segregation as well as the particle size distribution of polyethylene particles can be in practice adjusted by the choice of supported catalysts, by the conditions in the fluidized-bed polymerization reactor and by the fluid dynamics. We also attempt to predict how the reactor temperature affects the triboelectric charging of particles. (paper)

  10. Particle agglomeration and properties of nanofluids

    Energy Technology Data Exchange (ETDEWEB)

    Yang Yijun; Oztekin, Alparslan, E-mail: alo2@lehigh.edu; Neti, Sudhakar [Lehigh University, Department of Mechanical Engineering and Mechanics (United States); Mohapatra, Satish [Dynalene Inc. (United States)

    2012-05-15

    The present study demonstrates the importance of actual agglomerated particle size in the nanofluid and its effect on the fluid properties. The current work deals with 5 to 100 nm nanoparticles dispersed in fluids that resulted in 200 to 800 nm agglomerates. Particle size distributions for a range of nanofluids are measured by dynamic light scattering (DLS). Wet scanning electron microscopy method is used to visualize agglomerated particles in the dispersed state and to confirm particle size measurements by DLS. Our results show that a combination of base fluid chemistry and nanoparticle type is very important to create stable nanofluids. Several nanofluids resulted in stable state without any stabilizers, but in the long term had agglomerations of 250 % over a 2 month period. The effects of agglomeration on the thermal and rheological properties are presented for several types of nanoparticle and base fluid chemistries. Despite using nanodiamond particles with high thermal conductivity and a very sensitive laser flash thermal conductivity measurement technique, no anomalous increases of thermal conductivity was measured. The thermal conductivity increases of nanofluid with the particle concentration are as those predicted by Maxwell and Bruggeman models. The level of agglomeration of nanoparticles hardly influenced the thermal conductivity of the nanofluid. The viscosity of nanofluids increased strongly as the concentration of particle is increased; it displays shear thinning and is a strong function of the level of agglomeration. The viscosity increase is significantly above of that predicted by the Einstein model even for very small concentration of nanoparticles.

  11. Particle agglomeration and properties of nanofluids

    International Nuclear Information System (INIS)

    Yang Yijun; Oztekin, Alparslan; Neti, Sudhakar; Mohapatra, Satish

    2012-01-01

    The present study demonstrates the importance of actual agglomerated particle size in the nanofluid and its effect on the fluid properties. The current work deals with 5 to 100 nm nanoparticles dispersed in fluids that resulted in 200 to 800 nm agglomerates. Particle size distributions for a range of nanofluids are measured by dynamic light scattering (DLS). Wet scanning electron microscopy method is used to visualize agglomerated particles in the dispersed state and to confirm particle size measurements by DLS. Our results show that a combination of base fluid chemistry and nanoparticle type is very important to create stable nanofluids. Several nanofluids resulted in stable state without any stabilizers, but in the long term had agglomerations of 250 % over a 2 month period. The effects of agglomeration on the thermal and rheological properties are presented for several types of nanoparticle and base fluid chemistries. Despite using nanodiamond particles with high thermal conductivity and a very sensitive laser flash thermal conductivity measurement technique, no anomalous increases of thermal conductivity was measured. The thermal conductivity increases of nanofluid with the particle concentration are as those predicted by Maxwell and Bruggeman models. The level of agglomeration of nanoparticles hardly influenced the thermal conductivity of the nanofluid. The viscosity of nanofluids increased strongly as the concentration of particle is increased; it displays shear thinning and is a strong function of the level of agglomeration. The viscosity increase is significantly above of that predicted by the Einstein model even for very small concentration of nanoparticles.

  12. GOCI Level-2 Processing Improvements and Cloud Motion Analysis

    Science.gov (United States)

    Robinson, Wayne D.

    2015-01-01

    The Ocean Biology Processing Group has been working with the Korean Institute of Ocean Science and Technology (KIOST) to process geosynchronous ocean color data from the GOCI (Geostationary Ocean Color Instrument) aboard the COMS (Communications, Ocean and Meteorological Satellite). The level-2 processing program, l2gen has GOCI processing as an option. Improvements made to that processing are discussed here as well as a discussion about cloud motion effects.

  13. Fermilab | Science | Particle Physics | Benefits of Particle Physics

    Science.gov (United States)

    Photos and videos Latest news For the media Particle Physics Neutrinos Fermilab and the LHC Dark matter initiatives Research and development Key discoveries Benefits of particle physics Particle Accelerators society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery

  14. Introducing particle physics a graphic guide

    CERN Document Server

    AUTHOR|(CDS)2071677

    2013-01-01

    What really happens at the most fundamental levels of nature? Introducing Particle Physics explores the very frontiers of our knowledge, even showing how particle physicists are now using theory and experiment to probe our very concept of what is real. From the earliest history of the atomic theory through to supersymmetry, micro-black holes, dark matter, the Higgs boson, and the possibly mythical graviton, practising physicist and CERN contributor Tom Whyntie gives us a mind-expanding tour of cutting-edge science. Featuring brilliant illustrations from Oliver Pugh, Introducing Particle Physics is a unique tour through the most astonishing and challenging science being undertaken today.

  15. Classical dynamics of particles and systems

    CERN Document Server

    Marion, Jerry B

    1965-01-01

    Classical Dynamics of Particles and Systems presents a modern and reasonably complete account of the classical mechanics of particles, systems of particles, and rigid bodies for physics students at the advanced undergraduate level. The book aims to present a modern treatment of classical mechanical systems in such a way that the transition to the quantum theory of physics can be made with the least possible difficulty; to acquaint the student with new mathematical techniques and provide sufficient practice in solving problems; and to impart to the student some degree of sophistication in handl

  16. Particle Entrainment in Spherical-Cap Wakes

    Energy Technology Data Exchange (ETDEWEB)

    Warncke, Norbert G W; Delfos, Rene; Ooms, Gijs; Westerweel, Jerry, E-mail: n.g.w.warncke@tudelft.nl [Laboratory for Aero- and Hydrodynamics, Delft University of Technology (Netherlands)

    2011-12-22

    In this work we study the preferential concentration of small particles in the turbulent wake behind a spherical-cap object. We present a model predicting the mean particle concentration in the near-wake as a function of the characteristic Stokes number of the problem, the turbulence level and the Froude number. We compare the model with our experimental results on this flow, measured in a vertical water tunnel.

  17. Linear particle accelerator

    International Nuclear Information System (INIS)

    Richards, J.A.

    1977-01-01

    A linear particle accelerator which provides a pulsed beam of charged particles of uniform energy is described. The accelerator is in the form of an evacuated dielectric tube, inside of which a particle source is located at one end of the tube, with a target or window located at the other end of the dielectric tube. Along the length of the tube are externally located pairs of metal plates, each insulated from each other in an insulated housing. Each of the plates of a pair are connected to an electrical source of voltage of opposed polarity, with the polarity of the voltage of the plates oriented so that the plate of a pair, nearer to the particle source, is of the opposed polarity to the charge of the particle emitted by the source. Thus, a first plate about the tube located nearest the particle source, attracts a particle which as it passes through the tube past the first plate is then repelled by the reverse polarity of the second plate of the pair to continue moving towards the target

  18. Charged particle detector

    International Nuclear Information System (INIS)

    Hagen, R.D.

    1975-01-01

    A device for detecting the emission of charged particles from a specimen is described. The specimen is placed within an accumulator means which statically accumulates any charged particles emitted from the specimen. The accumulator means is pivotally positioned between a first capacitor plate having a positive electrical charge and a second capacitor plate having a negative electrical charge. The accumulator means is attracted to one capacitor plate and repelled from the other capacitor plate by an amount proportional to the amount and intensity of charged particles emitted by the specimen. (auth)

  19. Cosmology and particle physics

    International Nuclear Information System (INIS)

    Barrow, J.D.

    1982-01-01

    A brief overview is given of recent work that integrates cosmology and particle physics. The observational data regarding the abundance of matter and radiation in the Universe is described. The manner in which the cosmological survival density of stable massive particles can be calculated is discussed along with the process of cosmological nucleosynthesis. Several applications of these general arguments are given with reference to the survival density of nucleons, neutrinos and unconfined fractionally charge particles. The use of nucleosynthesis to limit the number of lepton generations is described together with the implications of a small neutrino mass for the origin of galaxies and clusters. (Auth.)

  20. Particles near threshold

    International Nuclear Information System (INIS)

    Bhattacharya, T.; Willenbrock, S.

    1993-01-01

    We propose returning to the definition of the width of a particle in terms of the pole in the particle's propagator. Away from thresholds, this definition of width is equivalent to the standard perturbative definition, up to next-to-leading order; however, near a threshold, the two definitions differ significantly. The width as defined by the pole position provides more information in the threshold region than the standard perturbative definition and, in contrast with the perturbative definition, does not vanish when a two-particle s-wave threshold is approached from below

  1. Sources for charged particles

    International Nuclear Information System (INIS)

    Arianer, J.

    1997-01-01

    This document is a basic course on charged particle sources for post-graduate students and thematic schools on large facilities and accelerator physics. A simple but precise description of the creation and the emission of charged particles is presented. This course relies on every year upgraded reference documents. Following relevant topics are considered: electronic emission processes, technological and practical considerations on electron guns, positron sources, production of neutral atoms, ionization, plasma and discharge, different types of positive and negative ion sources, polarized particle sources, materials for the construction of ion sources, low energy beam production and transport. (N.T.)

  2. Cosmology and particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Steigman, G [California Univ., Santa Barbara (USA). Inst. for Theoretical Physics; Bartol Research Foundation, Newark, Delaware (USA))

    1982-01-29

    The cosmic connections between physics on the very largest and very smallest scales are reviewed with an emphasis on the symbiotic relation between elementary particle physics and cosmology. After a review of the early Universe as a cosmic accelerator, various cosmological and astrophysical constraints on models of particle physics are outlined. To illustrate this approach to particle physics via cosmology, reference is made to several areas of current research: baryon non-conservation and baryon asymmetry; free quarks, heavy hadrons and other exotic relics; primordial nucleosynthesis and neutrino masses.

  3. Particle physics and cosmology

    International Nuclear Information System (INIS)

    Srednicki, M.

    1990-01-01

    At least eighty percent of the mass of the universe consists of some material which, unlike ordinary matter, neither emits nor absorbs light. This book collects key papers related to the discovery of this astonishing fact and its profound implications for astrophysics, cosmology, and the physics of elementary particles. The book focusses on the likely possibility that the dark matter is composed of an as yet undiscovered elementary particle, and examines the boundaries of our present knowledge of the properties such a particle must possess. (author). refs.; figs.; tabs

  4. Subway particles are more genotoxic than street particles and induce oxidative stress in cultured human lung cells.

    Science.gov (United States)

    Karlsson, Hanna L; Nilsson, Lennart; Möller, Lennart

    2005-01-01

    Epidemiological studies have shown an association between airborne particles and a wide range of adverse health effects. The mechanisms behind these effects include oxidative stress and inflammation. Even though traffic gives rise to high levels of particles in the urban air, people are exposed to even higher levels in the subway. However, there is a lack of knowledge regarding how particles from different urban subenvironments differ in toxicity. The main aim of the present study was to compare the ability of particles from a subway station and a nearby very busy urban street, respectively, to damage DNA and to induce oxidative stress. Cultured human lung cells (A549) were exposed to particles, DNA damage was analyzed using single cell gel electrophoresis (the comet assay), and the ability to induce oxidative stress was measured as 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation in lung cell DNA. We found that the subway particles were approximately eight times more genotoxic and four times more likely to cause oxidative stress in the lung cells. When the particles, water extracts from the particles, or particles treated with the metal chelator deferoxamine mesylate were incubated with 2'-deoxyguanosine (dG) and 8-oxodG was analyzed, we found that the oxidative capacity of the subway particles was due to redox active solid metals. Furthermore, analysis of the atomic composition showed that the subway particles to a dominating degree (atomic %) consisted of iron, mainly in the form of magnetite (Fe3O4). By using electron microscopy, the interaction between the particles and the lung cells was shown. The in vitro reactivity of the subway particles in combination with the high particle levels in subway systems give cause of concern due to the high number of people that are exposed to subway particles on a daily basis. To what extent the subway particles cause health effects in humans needs to be further evaluated.

  5. Particle emissions from compressed natural gas engines

    International Nuclear Information System (INIS)

    Ristovski, Z.D.; Morawska, L.; Hitchins, J.; Thomas, S.; Greenaway, C.; Gilbert, D.

    2000-01-01

    This paper presents the results of measurements conducted to determine particle and gas emissions from two large compressed natural gas (CNG) spark ignition (SI) engines. Particle size distributions in the range from 0.01-30 μm, and gas composition were measured for five power settings of the engines: 35, 50, 65, 80 and 100% of full power. Particle emissions in the size range between 0.5 and 30 μm, measured by the aerodynamic particle sizer (APS), were very low at a level below two particles cm -3 . These concentrations were comparable with average ambient concentration, and were not considered in the succeeding analysis. Both engines produce significant amounts of particles in the size range between 0.015 and 0.7 μm, measured by the scanning mobility particle size (SMPS). Maximum number of concentrations of about 1 x 10 7 particles cm -3 were very similar for both engines. The CMDs were in the range between 0.020 and 0.060 μm. The observed levels of particulate emission are in terms of number of the same order as emissions from heavy duty diesel engines (Morawska et al., Environ. Sci. Tech. 32, 2033-2042). On the other hand, emissions of CO and NO x of 5.53 and 3.33 g k W h -1 , respectively, for one of the tested engines, were considerably lower than set by the standards. According to the specifications for the gas emissions, provided by the US EPA (US EPA, 1997), this engine can be considered as a 'low-emission' engine, although emissions of submicrometer particles are of the same order as heavy-duty vehicles. (Author)

  6. The HUS solar flare and cosmic gamma-ray burst detector aboard the Ulysses spacecraft

    International Nuclear Information System (INIS)

    Boer, M.; Sommer, M.; Hurley, K.

    1990-02-01

    An overview of the instruments and of the scientific objectives of the Ulysses spacecraft is given. The experiment consists of two detectors: Two Si sensors operating in the range 5-20 keV, and two CsI (Tl) scintillators for the range 15-200 keV. The bit rate of the HUS experiment in the Ulysses telemetry is 40 bits/seconds and the time resolution is up to 4 s for the Si sensors and up to 8 ms for the scintillators. The total mass is 2.02 kg. The scientific objectives of the Ulysses mission are investigations on the physics of solar flares, such as their impulsive energy release, the heating and particle acceleration, the storage and the energy transport. The experiment will take place during the next solar maximum of 1991. (orig./HM)

  7. Descent imager/spectral radiometer (DISR) instrument aboard the Huygens probe of Titan

    Science.gov (United States)

    Tomasko, Martin G.; Doose, Lyn R.; Smith, Peter H.; Fellows, C.; Rizk, B.; See, C.; Bushroe, M.; McFarlane, E.; Wegryn, E.; Frans, E.; Clark, R.; Prout, M.; Clapp, S.

    1996-10-01

    The Huygen's probe of the atmosphere of Saturn's moon Titan includes one optical instrument sensitive to the wavelengths of solar radiation. The goals of this investigation fall into four broad areas: 1) the measurement of the profile of solar heating to support an improved understanding of the thermal balance of Titan and the role of the greenhouse effect in maintaining Titan's temperature structure; 2) the measurement of the size, vertical distribution, and optical properties of the aerosol and cloud particles in Titan's atmosphere to support studies of the origin, chemistry, life cycles, and role in the radiation balance of Titan played by these particles; 3) the composition of the atmosphere, particularly the vertical profile of the mixing ratio of methane, a condensable constituent in Titan's atmosphere; and 4) the physical state, composition, topography, and physical processes at work in determining the nature of the surface of Titan and its interaction with Titan's atmosphere. In order to accomplish these objectives, the Descent Imager/Spectral Radiometer (DISR) instrument makes extensive use of fiber optics to bring the light from several different sets of foreoptics to a silicon CCD detector, to a pair of InGaAs linear array detectors, and to three silicon photometers. Together these detectors permit DISR to make panoramic images of the clouds and surface of Titan, to measure the spectrum of upward and downward streaming sunlight from 350 to 1700 nm at a resolving power of about 200, to measure the reflection spectrum of >= 3000 locations on the surface, to measure the brightness and polarization of the solar aureole between 4 and 30 degrees from the sun at 500 and 935 nm, to separate the direct and diffuse downward solar flux at each wavelength measured, and to measure the continuous reflection spectrum of the ground between 850 and 1600 nm using an onboard lamp in the last 100 m of the descent.

  8. SUBMICRON PARTICLES EMISSION CONTROL BY ELECTROSTATIC AGGLOMERATION

    Directory of Open Access Journals (Sweden)

    Andrzej Krupa

    2017-04-01

    Full Text Available The aim of the study was to develop a device for more effective treatment of flue gases from submicron particles emitted by power plants burning bituminous coal and by this way the reduction of environment pollution. Electrostatic processes were employed to this goal, as the most effective solution. The solutions hitherto applied in electrostatic precipitation techniques were designed for large particles, typically with sizes> 5 µm, which are easily removed by the action of electrostatic force on the electrically charged particles. In submicron size range (0.1-1 µm the collection efficiency of an ESP is minimal, because of the low value of electric charge on such particles. In order to avoid problems with the removal of submicron particles of fly ash from the flue gases electrostatic agglomeration has been used. In this process, by applying an alternating electric field, larger charged particles (> 1 µm oscillate, and the particles "collect" smaller uncharged particles. In the developed agglomerator with alternating electric field, the charging of particles and the coagulation takes place in one stage that greatly simplified the construction of the device, compared to other solutions. The scope of this study included measurements of fractional collection efficiency of particles in the system comprising of agglomerator and ESP for PM1 and PM2.5 ranges, in device made in pilot scale. The collection efficiency for PM2.5 was greater than 90% and PM1 slightly dropped below 90%. The mass collection efficiency for PM2.5 was greater than 95%. The agglomerator stage increases the collection efficiency for PM1 at a level of 5-10%.

  9. Elementary particle interactions

    International Nuclear Information System (INIS)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.

    1992-10-01

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out

  10. Particle physics experiments 1989

    International Nuclear Information System (INIS)

    Bairstow, R.

    1990-01-01

    This report describes work carried out in 1989 on experiments approved by the Particle Physics Experiments Selection Panel of Rutherford Appleton Laboratory. The contents consist of unedited contributions from each experiment. (author)

  11. The Acquisition of Particles

    African Journals Online (AJOL)

    process of language acquisition on the basis of linguistic evidence the child is exposed to. ..... particle verbs are recognized in language processing differs from the way morphologically ..... In Natural Language and Linguistic Theory 11.

  12. Particle physics experiments 1987

    International Nuclear Information System (INIS)

    Stuart, G.W.

    1988-01-01

    This report describes work carried out in 1987 on experiments approved by the Particle Physics Experiments Selection Panel (United Kingdom). The contents consist of unedited contributions from each experiment. (author)

  13. Particle physics experiments

    International Nuclear Information System (INIS)

    Stuart, G.W.

    1986-01-01

    The report of the Rutherford Appleton Laboratory describes the work carried out in 1985 on experiments approved by the Particle Physics Experiments Selection Panel. The contents consist of unedited contributions from each experiment. (author)

  14. Particle physics experiments 1984

    International Nuclear Information System (INIS)

    Stuart, G.

    1985-01-01

    The Rutherford Appleton laboratory report describes work carried out in 1984 on experiments approved by the Particle Physics selection panel. The contents consist of unedited contributions from each experiment. (author)

  15. Search for Hidden Particles

    CERN Multimedia

    Solovev, V

    The SHiP Experiment is a new general-purpose fixed target facility at the SPS to search for hidden particles as predicted by a very large number of recently elaborated models of Hidden Sectors which are capable of accommodating dark matter, neutrino oscillations, and the origin of the full baryon asymmetry in the Universe. Specifically, the experiment is aimed at searching for very weakly interacting long lived particles including Heavy Neutral Leptons - right-handed partners of the active neutrinos; light supersymmetric particles - sgoldstinos, etc.; scalar, axion and vector portals to the hidden sector. The high intensity of the SPS and in particular the large production of charm mesons with the 400 GeV beam allow accessing a wide variety of light long-lived exotic particles of such models and of SUSY. Moreover, the facility is ideally suited to study the interactions of tau neutrinos.

  16. Blog: the God particle

    CERN Multimedia

    2007-01-01

    "Dateline video journalist Aaron Lewis this week reprots on the search to find the elusive "God particle", which, if found, could explain to scientists how everything in the world got its mass."(1/2 page)

  17. Research in particle theory

    International Nuclear Information System (INIS)

    Mansouri, F.; Suranyi, P; Wijewardhana, L.C.R.

    1991-10-01

    In the test particle approximation, the scattering amplitude for two-particle scattering in (2+1)-dimensional Chern-Simons-Witten gravity and supergravity was computed and compared to the corresponding metric solutions. The formalism was then extended to the exact gauge theoretic treatment of the two-particle scattering problem and compared to 't Hooft's results from the metric approach. We have studied dynamical symmetry breaking in 2+1 dimensional field theories. We have analyzed strong Extended Technicolor (ETC) models where the ETC coupling is close to a critical value. There are effective scalar fields in each of the theories. We have worked our how such scalar particles can be produced and how they decay. The φ 4 field theory was investigated in the Schrodinger representation. The critical behavior was extracted in an arbitrary number of dimensions in second order of a systematic truncation approximation. The correlation exponent agrees with known values within a few percent

  18. Big Bang Day: 5 Particles - 5. The Next Particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.

  19. Energetic particles detected by the Electron Reflectometer instrument on the Mars Global Surveyor, 1999-2006

    DEFF Research Database (Denmark)

    Delory, Gregory T.; Luhmann, Janet G.; Brain, David

    2012-01-01

    events at Mars associated with solar flares and coronal mass ejections, which includes the identification of interplanetary shocks. MGS observations of energetic particles at varying geometries between the Earth and Mars that include shocks produced by halo, limb, and backsided events provide a unique......We report the observation of galactic cosmic rays and solar energetic particles by the Electron Reflectometer instrument aboard the Mars Global Surveyor (MGS) spacecraft from May of 1999 to the mission conclusion in November 2006. Originally designed to detect low-energy electrons, the Electron...... recorded high energy galactic cosmic rays with similar to 45% efficiency. Comparisons of this data to galactic cosmic ray proton fluxes obtained from the Advanced Composition Explorer yield agreement to within 10% and reveal the expected solar cycle modulation as well as shorter timescale variations. Solar...

  20. Pore Formation and Mobility Investigation (PFMI): Concept, Hardware Development, and Initial Analysis of Experiments Conducted Aboard the International Space Station

    Science.gov (United States)

    Grugel, Richard N.

    2003-01-01

    Porosity in the form of "bubbles and pipes" can occur during controlled directional solidification processing of metal alloys. This is a consequence that 1) precludes obtaining any meaningful scientific results and 2) is detrimental to desired material properties. Unfortunately, several Microgravity experiments have been compromised by porosity. The intent of the PFMl investigation is to conduct a systematic effort directed towards understanding porosity formation and mobility during controlled directional solidification (DS) in a microgravity environment. PFMl uses a pure transparent material, succinonitrile (SCN), as well as SCN "alloyed" with water, in conjunction with a translating temperature gradient stage so that direct observation and recording of pore generation and mobility can be made. PFMl is investigating the role of thermocapillary forces and temperature gradients in affecting bubble dynamics as well as other solidification processes in a microgravity environment. This presentation will cover the concept, hardware development, operations, and the initial results from experiments conducted aboard the International Space Station.

  1. Design of an experiment to measure the fire exposure of radioactive materials packages aboard container cargo ships

    International Nuclear Information System (INIS)

    Koski, J.A.

    1997-11-01

    The test described in this paper is intended to measure the typical accident environment for a radioactive materials package in a fire aboard a container cargo ship. A stack of nine used standard cargo containers will be variously loaded with empty packages, simulated packages and combustible cargo and placed over a large hydrocarbon pool fire of one hour duration. Both internal and external fire container fire environments typical of on-deck stowage will be measured as well as the potential for container to container fire spread. With the use of the inverse heat conduction calculations, the local heat transfer to the simulated packages can be estimated from thermocouple data. Data recorded will also provide information on fire durations in each container, fire intensity and container to container fire spread characteristics

  2. Contribution to the study of solar prominences from observations performed on the LPSP instrument aboard the OSO-8 satellite

    International Nuclear Information System (INIS)

    Vial, Jean-Claude

    1981-01-01

    Notably by reprinting various documents and articles, this research reports works undertaken from the design of an experiment performed with the LPSP instrument aboard the OSO-8 satellite, to its data processing and interpretation. This experiment aimed at the study of the chromosphere fine structure by means of simultaneous high resolution observations of the L α, L β, Mg II, Ca II, H and K lines. The first part presents the on-board LPSP instrument. The second part reports observations of active and quiescent solar prominences. The third part reports the transfer calculation for five resonance lines (H Lα, Mg II H and K, Ca II H and K), and the comparison with observations performed on OSO-8

  3. Safe biodegradable fluorescent particles

    Science.gov (United States)

    Martin, Sue I [Berkeley, CA; Fergenson, David P [Alamo, CA; Srivastava, Abneesh [Santa Clara, CA; Bogan, Michael J [Dublin, CA; Riot, Vincent J [Oakland, CA; Frank, Matthias [Oakland, CA

    2010-08-24

    A human-safe fluorescence particle that can be used for fluorescence detection instruments or act as a safe simulant for mimicking the fluorescence properties of microorganisms. The particle comprises a non-biological carrier and natural fluorophores encapsulated in the non-biological carrier. By doping biodegradable-polymer drug delivery microspheres with natural or synthetic fluorophores, the desired fluorescence can be attained or biological organisms can be simulated without the associated risks and logistical difficulties of live microorganisms.

  4. PARTICLE BEAMS: Frontier course

    International Nuclear Information System (INIS)

    Anon.

    1987-01-01

    Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe

  5. Particle physics and cosmology

    International Nuclear Information System (INIS)

    Turner, M.S.; Schramm, D.N.

    1985-01-01

    During the past year, the research of the members of our group has spanned virtually all the topics at the interface of cosmology and particle physics: inflationary Universe scenarios, astrophysical and cosmological constraints on particle properties, ultra-high energy cosmic ray physics, quantum field theory in curved space-time, cosmology with extra dimensions, superstring cosmology, neutrino astronomy with large, underground detectors, and the formation of structure in the Universe

  6. Ionization particle detector

    International Nuclear Information System (INIS)

    Ried, L.

    1982-01-01

    A new device is claimed for detecting particles in a gas. The invention comprises a low cost, easy to assemble, and highly accurate particle detector using a single ionization chamber to contain a reference region and a sensing region. The chamber is designed with the radioactive source near one electrode and the second electrode located at a distance less than the distance of maximum ionization from the radioactive source

  7. PARTICLE BEAMS: Frontier course

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1987-01-15

    Driven by the quest for higher energies and optimal physics conditions, the behaviour of particle beams in accelerators and storage rings is the subject of increasing attention. Thus the second course organized jointly by the US and CERN Accelerator Schools looked towards the frontiers of particle beam knowledge. The programme held at South Padre Island, Texas, from 23-29 October attracted 125 participants including some 35 from Europe.

  8. The Least Particle Theory

    Science.gov (United States)

    Hartsock, Robert

    2011-10-01

    The Least Particle Theory states that the universe was cast as a great sea of energy. MaX Planck declared a quantum of energy to be the least value in the universe. We declare the quantum of energy to be the least particle in the universe. Stephen Hawking declared quantum mechanics to be of no value in todays gross mechanics. That's like saying the number 1 has no place in mathematics.

  9. Single particle dynamics

    International Nuclear Information System (INIS)

    Siemens, P.J.; Jensen, A.S.

    1985-01-01

    It is shown that the opening of the 3-quasiparticle continuum at 3Δ sets the energy scale for the enhancement of the effective mass near the Fermi surface of nuclei. The authors argue that the spreading width of single-particle states due to coupling with low-lying collective modes is qualitatively different from the two-body collision mechanism, and contributes little to the single-particle lifetime in the sense of the optical model. (orig.)

  10. Particle physics experiments 1986

    International Nuclear Information System (INIS)

    Stuart, G.W.

    1987-01-01

    The paper presents research work carried out in 1986 on 52 elementary particle experiments approved by the Particle Physics Experiments Selection Panel. Most of the experiments were collaborative and involved research groups from different countries. About half of the experiments were conducted at CERN, the remaining experiments employed the accelerators: LAMPT, LEP, PETRA, SLAC, and HERA. The contents consist of unedited contributions from each experiment. (U.K.)

  11. Gravity, particles and astrophysics

    International Nuclear Information System (INIS)

    Wesson, P.S.

    1980-01-01

    The author deals with the relationship between gravitation and elementary particle physics, and the implications of these subjects for astrophysics. The text is split up into two parts. The first part represents a relatively non-technical overview of the subject, while the second part represents a technical examination of the most important aspects of non-Einsteinian gravitational theory and its relation to astrophysics. Relevant references from the fields of gravitation, elementary particle theory and astrophysics are included. (Auth.)

  12. Particle electric dipole moments

    CERN Document Server

    Pendlebury, J M

    2000-01-01

    Measurements of particle electric dipole moments (EDMs) continue to put powerful constraints on theories of T-symmetry and CP-symmetry violation, which form currently one of the most prominent fields in particle physics. EDM measurements have been concentrated on neutral systems such as the neutron and atoms and molecules. These measurements allow one to deduce, in turn, the electric dipole moments of the fundamental fermions, that is, the lighter leptons and quarks and also those of some heavy nuclei.

  13. Applications of particle accelerators

    International Nuclear Information System (INIS)

    Barbalat, O.

    1994-01-01

    Particle accelerators are now widely used in a variety of applications for scientific research, applied physics, medicine, industrial processing, while possible utilisation in power engineering is envisaged. Earlier presentations of this subject, given at previous CERN Accelerator School sessions have been updated with papers contributed to the first European Conference on Accelerators in Applied Research and Technology (ECAART) held in September 1989 in Frankfurt and to the Second European Particle Accelerator Conference in Nice in June 1990. (orig.)

  14. Synthetic torpor: A method for safely and practically transporting experimental animals aboard spaceflight missions to deep space

    Science.gov (United States)

    Griko, Yuri; Regan, Matthew D.

    2018-02-01

    Animal research aboard the Space Shuttle and International Space Station has provided vital information on the physiological, cellular, and molecular effects of spaceflight. The relevance of this information to human spaceflight is enhanced when it is coupled with information gleaned from human-based research. As NASA and other space agencies initiate plans for human exploration missions beyond low Earth orbit (LEO), incorporating animal research into these missions is vitally important to understanding the biological impacts of deep space. However, new technologies will be required to integrate experimental animals into spacecraft design and transport them beyond LEO in a safe and practical way. In this communication, we propose the use of metabolic control technologies to reversibly depress the metabolic rates of experimental animals while in transit aboard the spacecraft. Compared to holding experimental animals in active metabolic states, the advantages of artificially inducing regulated, depressed metabolic states (called synthetic torpor) include significantly reduced mass, volume, and power requirements within the spacecraft owing to reduced life support requirements, and mitigated radiation- and microgravity-induced negative health effects on the animals owing to intrinsic physiological properties of torpor. In addition to directly benefitting animal research, synthetic torpor-inducing systems will also serve as test beds for systems that may eventually hold human crewmembers in similar metabolic states on long-duration missions. The technologies for inducing synthetic torpor, which we discuss, are at relatively early stages of development, but there is ample evidence to show that this is a viable idea and one with very real benefits to spaceflight programs. The increasingly ambitious goals of world's many spaceflight programs will be most quickly and safely achieved with the help of animal research systems transported beyond LEO; synthetic torpor may

  15. Dispersal of sticky particles

    Science.gov (United States)

    Reddy, Ramana; Kumar, Sanjeev

    2007-12-01

    In this paper, we show through simulations that when sticky particles are broken continually, particles are dispersed into fine dust only if they are present in a narrow range of volume fractions. The upper limit of this range is 0.20 in the 2D and 0.10 in the 3D space. An increase in the dimensionality of space reduces the upper limit nearly by a factor of two. This scaling holds for dispersal of particles in hyperdimensional space of dimensions up to ten, the maximum dimension studied in this work. The maximum values of volume fractions obtained are significantly lower than those required for close packing and random packing of discs in 2D and spheres in 3D space. These values are also smaller than those required for critical phenomena of cluster percolation. The results obtained are attributed to merger cascades of sticky particles, triggered by breakup events. A simple theory that incorporates this cascade is developed to quantitatively explain the observed scaling of the upper limit with the dimensionality of space. The theory also captures the dynamics of the dispersal process in the corresponding range of particle volume fractions. The theory suggests that cascades of order one and two predominantly decide the upper limit for complete dispersal of particles.

  16. Selection Of Suitable Particle Size And Particle Ratio For Japanese Cucumber Cucumis Sativus L. Plants

    Directory of Open Access Journals (Sweden)

    Galahitigama GAH

    2015-08-01

    Full Text Available This study was conducted to select the best particle size of coco peat for cucumber nurseries as well as best particle ratio for optimum plant growth and development of cucumber. The experiment was carried out in International Foodstuff Company and Faculty of Agriculture University of Ruhuna Sri Lanka during 2015 to 2016. Under experiment one three types of different particle sizes were used namely fine amp88040.5mm T2 medium 3mm-0.5mm T3 and coarse 4mm T4 with normal coco peat T1 as treatments. Complete Randomized Design CRD used as experimental design with five replicates. Germination percentage number of leaves per seedling seedling height in frequent day intervals was taken as growth parameters. Analysis of variance procedure was applied to analyze the data at 5 probability level. The results revealed that medium size particle media sieve size 0.5mm -3mm of coco peat was the best particle size for cucumber nursery practice when considered the physical and chemical properties of medium particles of coco peat. In the experiment of selecting of suitable particle ratio for cucumber plants the compressed mixture of coco peat particles that contain 70 ww unsieved coco peat 20 ww coarse particles and 10 ww coconut husk chips 5 12mm has given best results for growth performances compared to other treatments and cucumber grown in this mixture has shown maximum growth and yield performances.

  17. spinning self-dual particles

    International Nuclear Information System (INIS)

    Gamboa, J.; Rivelles, V.O.

    1989-01-01

    Self-dual particles in two-dimensions are presented. They were obtained from chiral boson particle by square root technique. The propagator of spinning self-dual particle is calculated using the BFV formalism. (M.C.K.)

  18. Effect of silica particle size on macrophage inflammatory responses.

    Directory of Open Access Journals (Sweden)

    Toshimasa Kusaka

    Full Text Available Amorphous silica particles, such as nanoparticles (<100 nm diameter particles, are used in a wide variety of products, including pharmaceuticals, paints, cosmetics, and food. Nevertheless, the immunotoxicity of these particles and the relationship between silica particle size and pro-inflammatory activity are not fully understood. In this study, we addressed the relationship between the size of amorphous silica (particle dose, diameter, number, and surface area and the inflammatory activity (macrophage phagocytosis, inflammasome activation, IL-1β secretion, cell death and lung inflammation. Irrespective of diameter size, silica particles were efficiently internalized by mouse bone marrow-derived macrophages via an actin cytoskeleton-dependent pathway, and induced caspase-1, but not caspase-11, activation. Of note, 30 nm-1000 nm diameter silica particles induced lysosomal destabilization, cell death, and IL-1β secretion at markedly higher levels than did 3000 nm-10000 nm silica particles. Consistent with in vitro results, intra-tracheal administration of 30 nm silica particles into mice caused more severe lung inflammation than that of 3000 nm silica particles, as assessed by measurement of pro-inflammatory cytokines and neutrophil infiltration in bronchoalveolar lavage fluid of mice, and by the micro-computed tomography analysis. Taken together, these results suggest that silica particle size impacts immune responses, with submicron amorphous silica particles inducing higher inflammatory responses than silica particles over 1000 nm in size, which is ascribed not only to their ability to induce caspase-1 activation but also to their cytotoxicity.

  19. The CPLEAR particle identification detector

    International Nuclear Information System (INIS)

    Angelopoulos, A.; Apostolakis, A.; Rozaki, E.; Sakeliou, L.; Backenstoss, G.; Kuzminski, J.; Rickenbach, R.; Wildi, M.; Carlson, P.; Francis, D.; Jansson, K.; Jon-And, K.; Kerek, A.; Szilagyi, S.; Carvalho, J.; Cobbaert, H.; Ferreira-Marques, R.; Machado, E.; Onofre, A.; Pinto da Cunha, J.; Policarpo, A.; Charalambous, S.; Chardalas, M.; Dedoussis, S.; Touramanis, C.; Fassnacht, P.; Pelucchi, F.; Fetcher, W.; Gerber, H.J.; Fuglesang, C.; Kesseler, G.; Montanet, F.; Go, A.; Lawry, T.; Miller, J.; Roberts, B.L.; Varner, G.; Warner, D.; Zimmerman, D.; Kokkas, P.; Pavlopoulos, P.; Sarigiannis, K.; Triantis, F.

    1992-01-01

    The CPLEAR experiment will measure CP violation parameters in the neutral kaon system, using a low energy antiproton beam from the Low Energy Antiproton Ring (LEAR) at CERN. One of its subdetectors, the Particle Identification Detector (PID), makes a fast separation of pions and kaons, which is essential for the experiment. This article describes the design of the PID and its performance during beam tests and during initial runs at LEAR. A pion rejection efficiency of 99.7% for the first level trigger (after 60 ns) is found in the relevant momentum region. (orig.)

  20. Nonlinear dynamics in particle accelerators

    CERN Document Server

    Dilão, Rui

    1996-01-01

    This book is an introductory course to accelerator physics at the level of graduate students. It has been written for a large audience which includes users of accelerator facilities, accelerator physicists and engineers, and undergraduates aiming to learn the basic principles of construction, operation and applications of accelerators.The new concepts of dynamical systems developed in the last twenty years give the theoretical setting to analyse the stability of particle beams in accelerator. In this book a common language to both accelerator physics and dynamical systems is integrated and dev

  1. The CPLEAR particle identification detector

    Energy Technology Data Exchange (ETDEWEB)

    Angelopoulos, A.; Apostolakis, A.; Rozaki, E.; Sakeliou, L. (Univ. Athens (Greece)); Backenstoss, G.; Kuzminski, J.; Rickenbach, R.; Wildi, M. (Univ. Basel (Switzerland)); Carlson, P.; Francis, D.; Jansson, K.; Jon-And, K.; Kerek, A.; Szilagyi, S. (Manne Siegbahn Inst. Stockholm (Sweden)); Carvalho, J.; Cobbaert, H.; Ferreira-Marques, R.; Machado, E.; Onofre, A.; Pinto da Cunha, J.; Policarpo, A. (Univ. Coimbra, LIP (Portugal) Technical Univ., Delft (Netherlands)); Charalambous, S.; Chardalas, M.; Dedoussis, S.; Touramanis, C. (Univ. Thessaloniki (Greece)); Fassnacht, P.; Pelucchi, F. (CPPM, Marseille (France) CSNSM, Orsay (France) P. Scherrer Inst., Villingen (Switzerland) DPhPe, CEN-Saclay, 91 - Gif-sur-Yvette (France)); Fetcher, W.; Gerber, H.J. (Inst. fuer Mittelenergiephysik, ETH Villingen (Switzerland)); Fuglesang, C.; Kesseler, G.; Montanet, F. (CERN, Geneva (Switzerland)); Go, A.; Lawry, T.; Miller, J.; Roberts, B.L.; Varner, G.; Warner, D.; Zimmerman, D. (Univ. Boston,; CPLEAR Collaboration

    1992-01-01

    The CPLEAR experiment will measure CP violation parameters in the neutral kaon system, using a low energy antiproton beam from the Low Energy Antiproton Ring (LEAR) at CERN. One of its subdetectors, the Particle Identification Detector (PID), makes a fast separation of pions and kaons, which is essential for the experiment. This article describes the design of the PID and its performance during beam tests and during initial runs at LEAR. A pion rejection efficiency of 99.7% for the first level trigger (after 60 ns) is found in the relevant momentum region. (orig.).

  2. Nuclear thermodynamics below particle threshold

    International Nuclear Information System (INIS)

    Schiller, A.; Agvaanluvsan, U.; Algin, E.; Bagheri, A.; Chankova, R.; Guttormsen, M.; Hjorth-Jensen, M.; Rekstad, J.; Siem, S.; Sunde, A. C.; Voinov, A.

    2005-01-01

    From a starting point of experimentally measured nuclear level densities, we discuss thermodynamical properties of nuclei below the particle emission threshold. Since nuclei are essentially mesoscopic systems, a straightforward generalization of macroscopic ensemble theory often yields unphysical results. A careful critique of traditional thermodynamical concepts reveals problems commonly encountered in mesoscopic systems. One of which is the fact that microcanonical and canonical ensemble theory yield different results, another concerns the introduction of temperature for small, closed systems. Finally, the concept of phase transitions is investigated for mesoscopic systems

  3. Laboratory evaluation of a gasifier particle sampling system using model compounds of different particle morphology

    Energy Technology Data Exchange (ETDEWEB)

    Nilsson, Patrik T.; Malik, Azhar; Pagels, Joakim; Lindskog, Magnus; Rissler, Jenny; Gudmundsson, Anders; Bohgard, Mats; Sanati, Mehri [Lund University, Division of Ergonomics and Aerosol Technology, P.O. Box 118, Lund (Sweden)

    2011-07-15

    The objective of this work was to design and evaluate an experimental setup to be used for field studies of particle formation in biomass gasification processes. The setup includes a high-temperature dilution probe and a denuder to separate solid particles from condensable volatile material. The efficiency of the setup to remove volatile material from the sampled stream and the influence from condensation on particles with different morphologies is presented. In order to study the sampling setup model, aerosols were created with a nebulizer to produce compact and solid KCl particles and a diffusion flame burner to produce agglomerated and irregular soot particles. The nebulizer and soot generator was followed by an evaporation-condensation section where volatile material, dioctylsebacete (DOS), was added to the system as a tar model compound. The model aerosol particles were heated to 200 C to create a system containing both solid particles and volatile organic material in gas phase. The heated aerosol particles were sampled and diluted at the same temperature with the dilution probe. Downstream the probe, the DOS was adsorbed in the denuder. This was achieved by slowly decreasing the temperature of the diluted sample towards ambient level in the denuder. Thereby the supersaturation of organic vapors was reduced which decreased the probability for tar condensation and nucleation of new particles. Both the generation system and the sampling technique gave reproducible results. A DOS collection efficiency of >99% was achieved if the denuder inlet concentration was diluted to less than 1-6 mg/m{sup 3} depending on the denuder flow rate. Concentrations higher than that lead to significant impact on the resulting KCl size distribution. The choice of model compounds was done to study the effect from the particle morphology on the achieved particle characteristics after the sampling setup. When similar amounts of volatile material condensed on soot agglomerates and

  4. On the mass spectrum of particles

    International Nuclear Information System (INIS)

    Sajo, Istvan

    1983-01-01

    An eigenvalue formula of general validity was developed with correct mathematical methods from measured data of the stationary mass and self-energy of stationary particles; this is able to generate universally the mass of particles belonging to any class or group, i.e. to produce the spectra of particles with a stationary mass surpassing that of the electron. The author shows that this eigenvalue formula can be produced as the produc t of several partial formulae which, separately, are not more complicated than that developed by Balmer from data measured on the spectrum of the hydrogen atom. The validity of the first version of the formulae was checked for many particles discovered subsequently. The results are published in detail in the present paper, together with the method of development of the universal eigenvalue formula generating the mass spectrum of elementary particles. The formulae describing the discrete energy levels of the particles can be extended by considering the theory of special relativity, also to the mass of moving particles proportional with their inertia. (author)

  5. Sedimentation of athermal particles in clay suspensions

    Science.gov (United States)

    Clotet, Xavier; Kudrolli, Arshad

    2015-03-01

    We discuss sedimentation of athermal particles in dense clay suspensions which appear liquid-like to glass-like. These studies are motivated by the physics important to a diverse range of problems including remediation of oil sands after the extraction of hydrocarbons, and formation of filter cakes in bore wells. We approach this problem by first considering collective sedimentation of athermal spherical particles in a viscous liquid in quasi-two dimensional and three dimensional containers. We examine the system using optical and x-ray tomography techniques which gives particle level information besides global information on the evolution of the volume fraction. Unlike sediments in the dilute limit - which can be modeled as isolated particles that sediment with a constant velocity and slow down exponentially as they approach the bottom of the container - we find interaction between the particles through the viscous fluids leads to qualitatively differences. We find significant avalanching behavior and cooperative motion as the grains collectively settle, and non-exponential increase in settling time. We discuss the effect of stirring caused by the sedimenting particles on their viscosity and consequently the sedimentation rates as a function of particle concentration. Supported by Petroleum Research Fund Grant PRF # 54045-ND9.

  6. Short-duration Electron Precipitation Studied by Test Particle Simulation

    Directory of Open Access Journals (Sweden)

    Jaejin Lee

    2015-12-01

    Full Text Available Energy spectra of electron microbursts from 170 keV to 340 keV have been measured by the solid-state detectors aboard the low-altitude (680 km polar-orbiting Korean STSAT-1 (Science and Technology SATellite. These measurements have revealed two important characteristics unique to the microbursts: (1 They are produced by a fast-loss cone-filling process in which the interaction time for pitch-angle scattering is less than 50 ms and (2 The e-folding energy of the perpendicular component is larger than that of the parallel component, and the loss cone is not completely filled by electrons. To understand how wave-particle interactions could generate microbursts, we performed a test particle simulation and investigated how the waves scattered electron pitch angles within the timescale required for microburst precipitation. The application of rising-frequency whistler-mode waves to electrons of different energies moving in a dipole magnetic field showed that chorus magnetic wave fields, rather than electric fields, were the main cause of microburst events, which implied that microbursts could be produced by a quasi-adiabatic process. In addition, the simulation results showed that high-energy electrons could resonate with chorus waves at high magnetic latitudes where the loss cone was larger, which might explain the decreased e-folding energy of precipitated microbursts compared to that of trapped electrons.

  7. On the origin of particle fluxes from thunderclouds

    International Nuclear Information System (INIS)

    Chilingarian, A.; Chilingaryan, S.; Karapetyan, T.; Khanikyants, Y.; Pokhsraryan, D.; Soghomonyan, S.

    2017-01-01

    We present the observational data on registration of atmospheric discharges simultaneously with the detection of elementary particles performed during thunderstorms at 3200m altitudes above sea level on Mt. Aragats in Armenia. Throughout the 2016 summer campaign on Aragats we monitored lightning occurrences and signals from NaI spectrometers, plastic scintillators, and Neutron Monitor proportional counters, and analyzed the shape of registered pulses. Particle detector signals were synchronized with lightning occurrences on microsecond time scale. Our measurements prove that all signals registered by particle detectors simultaneously with lightning were Electromagnetic interferences (EMI) and not typical responses of particle detectors on the passage of neutral or charged elementary particles. (author)

  8. The GNSS polarimetric radio-occultation technique to sense precipitation events: a new concept to be tested aboard PAZ Low Earth Satellite

    Science.gov (United States)

    Tomás, Sergio; Oliveras, Santi; Cardellach, Estel; Rius, Antonio

    2013-04-01

    The Radio Occultation and Heavy Precipitation (ROHP) experiment, to be conducted aboard the Spanish PAZ satellite, consists of a radio occultation (RO) mission provided with dual-polarization capabilities. The research with polarimetric RO data has the goal of assessing the capabilities and limitations of this technique to infer profiles of heavy precipitation. The technique aims to provide vertical profiles of precipitation simultaneously to the vertical profiles of thermodynamic parameters (standard RO products) perfectly collocated both in space and time. If successful, the polarimetric RO will represent the first technique able to provide these complementary information on precipitation. This is a relevant input for studies on heavy and violent rainfall events, which being poorly represented by the current-generation of Numerical Weather Prediction and General Circulation Models appear to be difficult to forecast on all time-scales. The Low Earth Orbiter hosting this experiment, to be launched in 2013, will orbit at 500 km altitude in a near-Polar orbit. The Radio Occulation payload includes a RO GNSS receiver and a dual polarization (H/V) limb oriented antenna to capture the signals of setting GNSS transmitters. NOAA and UCAR participate in the ground-segment of the radiometric experiment to enable near-real time dissemination of the level-1 standard RO products. The space-based GNSS RO technique scans the atmosphere vertically at fine resolution (close to 300 meter in the troposphere) by precisely measure the delay between a GNSS transmitter and a GNSS receiver aboard a Low Earth Orbiter, when the former is setting below or rising above the Earth limb. The standard, thermodynamical, products are extracted from the excess delay induced by the atmosphere at different layers. This presentation will not focus on this well-established application, but a novel concept using polarimetry to also retrieve rain information. The precipitation-measurement principle is

  9. Cytotoxic effect of galvanically coupled magnesium-titanium particles.

    Science.gov (United States)

    Kim, Jua; Gilbert, Jeremy L

    2016-01-01

    Recent work has shown that reduction reactions at metallic biomaterial surfaces can induce significant killing of cells in proximity to the surface. To exploit this phenomenon for therapeutic purposes, for example, for cancer tumor killing or antibacterial effects (amongst other applications), magnesium metal particles, galvanically coupled to titanium by sputtering, have been evaluated for their cell-killing capability (i.e. cytotoxicity). Magnesium (Mg) particles large enough to prevent particle phagocytosis were investigated, so that only electrochemical reactions, and not particle toxicity per se, caused cytotoxic effects. Titanium (Ti) coated magnesium particles, as well as magnesium-only particles were introduced into MC3T3-E1 mouse pre-osteoblast cell cultures over a range of particle concentrations, and cells were observed to die in a dosage-dependent manner. Ti-coated magnesium particles killed more cells at lower particle concentration than magnesium alone (Pmagnesium and magnesium-titanium had no significant difference at similar particle concentrations. Complete cell killing occurred at 750μg/ml and 1500μg/ml for Mg-Ti and Mg, respectively. Thus, this work demonstrates that galvanically coupled Mg-Ti particles have a significant cell killing capability greater than Mg alone. In addition, when the pH associated with complete killing with particles was created using NaOH only (no particles), then the percentage of cells killed was significantly less (Pmagnesium-titanium microparticles kill cells more effectively than magnesium particles alone. The killing effect was shown to not be due to pH shifts since no differences were seen for different particle types and pH adjusted medium without particles did not exhibit the same level of killing. The significance of this work is the recognition of this killing effect with Mg particles and the potential therapeutic applications in infection control and cancer treatment that this process may provide. Copyright

  10. Proton: the particle.

    Science.gov (United States)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10(80). Protons were created at 10(-6) -1 second after the Big Bang at ≈1.37 × 10(10) years beforethe present. Proton life span has been experimentally determined to be ≥10(34) years; that is, the age of the universe is 10(-24)th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W(+), W(-), Z(0), and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter. Copyright © 2013 Elsevier Inc. All

  11. Proton: The Particle

    Energy Technology Data Exchange (ETDEWEB)

    Suit, Herman

    2013-11-01

    The purpose of this article is to review briefly the nature of protons: creation at the Big Bang, abundance, physical characteristics, internal components, and life span. Several particle discoveries by proton as the experimental tool are considered. Protons play important roles in science, medicine, and industry. This article was prompted by my experience in the curative treatment of cancer patients by protons and my interest in the nature of protons as particles. The latter has been stimulated by many discussions with particle physicists and reading related books and journals. Protons in our universe number ≈10{sup 80}. Protons were created at 10{sup −6} –1 second after the Big Bang at ≈1.37 × 10{sup 10} years beforethe present. Proton life span has been experimentally determined to be ≥10{sup 34} years; that is, the age of the universe is 10{sup −24}th of the minimum life span of a proton. The abundance of the elements is hydrogen, ≈74%; helium, ≈24%; and heavier atoms, ≈2%. Accordingly, protons are the dominant baryonic subatomic particle in the universe because ≈87% are protons. They are in each atom in our universe and thus involved in virtually every activity of matter in the visible universe, including life on our planet. Protons were discovered in 1919. In 1968, they were determined to be composed of even smaller particles, principally quarks and gluons. Protons have been the experimental tool in the discoveries of quarks (charm, bottom, and top), bosons (W{sup +}, W{sup −}, Z{sup 0}, and Higgs), antiprotons, and antineutrons. Industrial applications of protons are numerous and important. Additionally, protons are well appreciated in medicine for their role in radiation oncology and in magnetic resonance imaging. Protons are the dominant baryonic subatomic particle in the visible universe, comprising ≈87% of the particle mass. They are present in each atom of our universe and thus a participant in every activity involving matter.

  12. Higgs Boson: god particle or divine comedy?

    Science.gov (United States)

    Rangacharyulu, Chary

    2013-10-01

    While particle physicists around the world rejoice the announcement of discovery of Higgs particle as a momentous event, it is also an opportune moment to assess the physicists' conception of nature. Particle theorists, in their ingenious efforts to unravel mysteries of the physical universe at a very fundamental level, resort to macroscopic many body theoretical methods of solid state physicists. Their efforts render the universe a superconductor of correlated quasi-particle pairs. Experimentalists, devoted to ascertain the elementary constituents and symmetries, depend heavily on numerical simulations based on those models and conform to theoretical slang in planning and interpretation of measurements . It is to the extent that the boundaries between theory/modeling and experiment are blurred. Is it possible that they are meandering in Dante's Inferno?

  13. Entanglement between particle partitions in itinerant many-particle states

    NARCIS (Netherlands)

    Haque, M.; Zozulya, O.S.; Schoutens, K.

    2009-01-01

    We review 'particle-partitioning entanglement' for itinerant many-particle systems. This is defined as the entanglement between two subsets of particles making up the system. We identify generic features and mechanisms of particle entanglement that are valid over whole classes of itinerant quantum

  14. Particle physics and cosmology

    International Nuclear Information System (INIS)

    Kolb, E.W.

    1986-10-01

    This series of lectures is about the role of particle physics in physical processes that occurred in the very early stages of the bug gang. Of particular interest is the role of particle physics in determining the evolution of the early Universe, and the effect of particle physics on the present structure of the Universe. The use of the big bang as a laboratory for placing limits on new particle physics theories will also be discussed. Section 1 reviews the standard cosmology, including primordial nucleosynthesis. Section 2 reviews the decoupling of weakly interacting particles in the early Universe, and discusses neutrino cosmology and the resulting limits that may be placed on the mass and lifetime of massive neutrinos. Section 3 discusses the evolution of the vacuum through phase transitions in the early Universe and the formation of topological defects in the transitions. Section 4 covers recent work on the generation of the baryon asymmetry by baryon-number violating reactions in Grand Unified Theories, and mentions some recent work on baryon number violation effects at the electroweak transition. Section 5 is devoted to theories of cosmic inflation. Finally, Section 6 is a discussion of the role of extra spatial dimensions in the evolution of the early Universe. 78 refs., 32 figs., 6 tabs

  15. Neutron particle injection device

    International Nuclear Information System (INIS)

    Hashimoto, Kiyoshi.

    1997-01-01

    Plasma particles are used as target particles for converting ions to neutral particles by a charge exchange reaction in a neutralization cell, and a neutralization cell is disposed in adjacent with drawing electrodes. In addition, a magnetic field generation means is disposed additionally for generating magnetic rays substantially in parallel with the drawing electrode at the downmost stream in the progressing direction of the ions. The intensity of electric fields between the drawing electrode at the downmost stream and the nearest electrode, among electrodes present at the upstream, is made smaller than the intensity of electric fields between other electrodes. Since magnetic rays substantially in parallel with the drawing electrode at the downmost stream in the progressing direction of the ions are generated, the ions are prevented from being accelerated in the direction reverse to the progressing direction thereby further enhancing the neutralization efficiency of the neutralizing cell. Then, there can be provided effects that the constitution of the electrode of NBI (Neutral particle Beam Injector) can be simplified and the power source for preventing acceleration of neutral particles can be saved. (N.H.)

  16. Cosmology and particle physics

    International Nuclear Information System (INIS)

    Salati, P.

    1986-01-01

    If the hot Big Bang model is correct, the very early universe provides us with a good laboratory to test our ideas on particle physics. The temperature and the density at that time are so high that each known particle must exist in chemical and in thermal equilibrium with the others. When the universe cools, the particles freeze out, leaving us today with a cosmic background. Such a kind of relic is of great interest because we can probe the Big Bang Model by studying the fossilized gas of a known particle. Conversely we can use that model to derive information about a hypothetical particle. Basically the freezing of a gas occurs a temperature T o and may be thermal or chemical. Studying the decoupling of a stable neutrino brings information on its mass: if the mass M ν lies in the forbidden range, the neutrino has to be unstable and its lifetime is constrained by cosmology. As for the G.U.T. Monopole, cosmology tells us that its present mass density is either to big or to small (1 monopole/observable universe) owing to a predicted flux far from the Parker Limit. Finally, the super red-giant star life time constrains the axion or the Higgs to be more massive than .2 MeV [fr

  17. New particle searches

    International Nuclear Information System (INIS)

    Derrick, M.

    1985-01-01

    The Standard Model is a remarkable result of decades of work in particle physics, but it is clearly an incomplete representation of the world. Exploring possibilities beyond the Standard Model is a major preoccupation of both theorists and experimentalists. Despite the many suggestions that are extant about the missing links within the Standard Model as well as extensions beyond it, no hard experimental evidence exists. In particular, in more than five years of experimentation both at PETRA and PEP no new particles have been found that would indicate new physics. Several reasons are possible for these negative results: the particles may be too heavy; the experiments may not be looking in the proper way; the cross sections may be too small or finally the particles may not exist. A continuing PEP program, at high luminosity will ensure that the second and third reason continue to be addressed. The higher energy e + e - storage rings such as TRISTAN and LEP will extend the mass limits. High mass particles can also be produced at the CERN collider and soon with the Tevatron collider. A concise summary of the mass limits from the PETRA experiments has been given in a recent Mark J publication. The results shown provide a convenient yardstick against which to measure future search experiments

  18. Big Bang Day: 5 Particles - 3. The Anti-particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

  19. Cytotoxicity evaluation of ceramic particles of different sizes and shapes.

    Science.gov (United States)

    Yamamoto, Akiko; Honma, Rieko; Sumita, Masae; Hanawa, Takao

    2004-02-01

    When artificial hip or knee joints are implanted in the human body, they release metallic, ceramic, and polymeric debris into the surrounding tissues. The toxicity of the released particles is of two types: chemical, caused by the released soluble ions and monomers, and mechanical, a result of mechanical stimulation produced by the insoluble particles. In this study, the cytotoxicity of particles of TiO2, Al2O3, ZrO2, Si3N4, and SiC for murine fibroblasts and macrophages were examined to evaluate just their mechanical toxicity because these particles are not expected to release soluble metal ions. Different sizes and shapes of TiO2 particles were used to evaluate the effect of size and shape on particle cytotoxicity. The results suggest that the cytotoxicity of ceramic particles does not depend on their chemical species. Cytotoxicity levels were lower than those of corresponding metal ions, indicating that the mechanical toxicity of particles is lower than the chemical toxicity of released soluble ions and monomers. The differences in size did not affect the mechanical toxicity of these particles. The dendritic particles had a higher cytotoxicity level for macrophages than did spindle and spheric particles. Copyright 2003 Wiley Periodicals, Inc. J Biomed Mater Res 68A: 244-256, 2004

  20. Dynamics of magnetic particles near a surface : model and experiments on field-induced disaggregation

    NARCIS (Netherlands)

    van Reenen, A.; Gao, Y.; de Jong, Arthur; Hulsen, M.A.; den Toonder, J.M.J.; Prins, M.W.J.

    2014-01-01

    Magnetic particles are widely used in biological research and bioanalytical applications. As the corresponding tools are progressively being miniaturized and integrated, the understanding of particle dynamics and the control of particles down to the level of single particles become important. Here,

  1. Effects of fluvial processes in different order river valleys on redistribution and storage of particle-bound radioactive caesium-137 in area of significant Chernobyl fallout and impact on linked rivers with lower contamination levels

    Science.gov (United States)

    Belyaev, Vladimir; Golosov, Valentin; Shamshurina, Evgeniya; Ivanov, Maxim; Ivanova, Nadezhda; Bezukhov, Dmitry; Onda, Yuichi; Wakiyama, Yoshifumi; Evrard, Olivier

    2015-04-01

    Detailed investigations of the post-fallout fate of radionuclide contamination represent an important task in terms of environmental quality assessment. In addition, particle-bound radionuclides such as the most widespread anthropogenic isotope caesium-137 can be used as tracers for quantitative assessment of different sediment redistribution processes. In landscapes of humid plains with agriculture-dominated land use the post-fallout redistribution of caesium-137 is primarily associated with fluvial activity of various scales in cascade systems starting from soil erosion on cultivated hillslopes through gully and small dry valley network into different order perennial streams and rivers. Our investigations in the so-called Plavsk hotspot (area of very high Chernobyl caesium-137 contamination within the Plava River basin, Tula Region, Central European Russia) has been continuing for more than 15 years by now, while the time passed since the Chernobyl disaster and associated radioactive fallout (1986) is almost 29 years. Detailed information on the fluvial sediment and associated caesium-137 redistribution has been obtained for case study sites of different size from individual cultivated slopes and small catchments of different size (2-180 km2) to the entire Plava River basin scale (1856 km2). It has been shown that most of the contaminated sediment over the time passed since the fallout has remained stored within the small dry valleys of the 1-4 Hortonian order and local reservoirs (>70%), while only about 5% reached the 5-6 order valleys (main tributaries of the Plava River) and storage of the Plava floodplain itself represents as low as 0.3% of the basin-scale total sediment production from eroded cultivated hillslopes. Nevertheless, it has been shown that contaminated sediment yield from the Plava River basin exerts significant influence on less polluted downstream-linked river system. Recent progress of the investigations involved sampling of 7 detailed depth

  2. Particles in flows

    CERN Document Server

    Galdi, Giovanni; Nečasová, Šárka

    2017-01-01

    This book aims to face particles in flows from many different, but essentially interconnected sides and points of view. Thus the selection of authors and topics represented in the chapters, ranges from deep mathematical analysis of the associated models, through the techniques of their numerical solution, towards real applications and physical implications. The scope and structure of the book as well as the selection of authors was motivated by the very successful summer course and workshop "Particles in Flows'' that was held in Prague in the August of 2014. This meeting revealed the need for a book dealing with this specific and challenging multidisciplinary subject, i.e. particles in industrial, environmental and biomedical flows and the combination of fluid mechanics, solid body mechanics with various aspects of specific applications.

  3. Charged particle accelerator

    International Nuclear Information System (INIS)

    Ress, T.I.; Nolde, G.V.

    1974-01-01

    A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to said enclosure for generating therein a magnetic field moving in a predetermined direction with respect to each point of said path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships [fr

  4. Detectors for Particle Radiation

    Science.gov (United States)

    Kleinknecht, Konrad

    1999-01-01

    This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

  5. Charged particle accelerator

    Energy Technology Data Exchange (ETDEWEB)

    Ress, T I; Nolde, G V

    1974-11-25

    A charged particle accelerator is described. It is made of an enclosure arranged for channeling a stream of charged particles along a predetermined path, and propelling means juxtaposed to the enclosure for generating a magnetic field moving in a predetermined direction with respect to each point of the path, the magnetic flux vector of that field being transverse to that path at every point, which gives the particles, along said path, a velocity connected to that of the mobile field by a predetermined relation. This can be applied to the fast production of chemical compounds, to the emission of neutrons and of thermal energy, and to the production of mechanical energy for propelling space ships.

  6. Radiance and particle fluence

    International Nuclear Information System (INIS)

    Papiez, L.; Battista, J.J.

    1994-01-01

    The International Commission on Radiological Units and Measurements (ICRU) has defined fluence in terms of the number of the radiation particles crossing a small sampling sphere. A second definition has been proposed in which the length of track segments contained within any sampling volume are used to calculate the incident fluence. This approach is often used in Monte Carlo simulations of individual particle tracks, allowing the fluence to be scored in small volumes of any shape. In this paper we stress that the second definition generalizes the classical (ICRU) concept of fluence. We also identify the assumptions inherent in the two definitions of fluence and prove their equivalence for the case of straight-line particle trajectories. (author)

  7. New particle data

    CERN Multimedia

    2002-01-01

    The 2002 edition of the Review of Particle Physics has been published. It appears in the July 1st edition of Physical Review D with the reference: K. Hagiwara et al., Physical Review D66, 010001 (2002). The printing of the Particle Physics Booklets is planned to be finished at the end of August, so copies are expected to arrive at CERN for distribution by mid-September. The full data are available at the Berkeley site, as well as at various other mirrors around the world. As for copies of the full Review, for which CERN is responsible for the distribution outside the Americas, the Far East and Australasia, the quantity has been reduced by 60% compared to the 2000 edition. It will thus no longer be possible for all individuals to have their personal copy. Priority will be given to ensure that copies are sent to all groups and institutes engaged in particle physics research.

  8. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2015-01-01

    This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

  9. The particle zoo

    CERN Document Server

    AUTHOR|(CDS)2079223

    2016-01-01

    What is everything really made of? If we split matter down into smaller and infinitesimally smaller pieces, where do we arrive? At the Particle Zoo - the extraordinary subatomic world of antimatter, neutrinos, strange-flavoured quarks and yetis, gravitons, ghosts and glueballs, mindboggling eleven-dimensional strings and the elusive Higgs boson itself. Be guided around this strangest of zoos by Gavin Hesketh, experimental particle physicist at humanity's greatest experiment, the Large Hadron Collider. Concisely and with a rare clarity, he demystifies how we are uncovering the inner workings of the universe and heading towards the next scientific revolution. Why are atoms so small? How did the Higgs boson save the universe? And is there a theory of everything? The Particle Zoo answers these and many other profound questions, and explains the big ideas of Quantum Physics, String Theory, The Big Bang and Dark Matter...and, ultimately, what we know about the true, fundamental nature of reality.

  10. Precision wood particle feedstocks

    Science.gov (United States)

    Dooley, James H; Lanning, David N

    2013-07-30

    Wood particles having fibers aligned in a grain, wherein: the wood particles are characterized by a length dimension (L) aligned substantially parallel to the grain, a width dimension (W) normal to L and aligned cross grain, and a height dimension (H) normal to W and L; the L.times.H dimensions define two side surfaces characterized by substantially intact longitudinally arrayed fibers; the W.times.H dimensions define two cross-grain end surfaces characterized individually as aligned either normal to the grain or oblique to the grain; the L.times.W dimensions define two substantially parallel top and bottom surfaces; and, a majority of the W.times.H surfaces in the mixture of wood particles have end checking.

  11. Magnetic particle inspection

    Science.gov (United States)

    Sastri, Sankar

    1990-01-01

    The purpose of this experiment is to familiarize the student with magnetic particle inspection and relate it to classification of various defects. Magnetic particle inspection is a method of detecting the presence of cracks, laps, tears, inclusions, and similar discontinuities in ferromagnetic materials such as iron and steel. This method will most clearly show defects that are perpendicular to the magnetic field. The Magnaglo method uses a liquid which is sprayed on the workpiece to be inspected, and the part is magnetized at the same time. The workpiece is then viewed under a black light, and the presence of discontinuity is shown by the formation of a bright indication formed by the magnetic particles over the discontinuity. The equipment and experimental procedures are described.

  12. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  13. WORKSHOP: Stable particle motion

    International Nuclear Information System (INIS)

    Ruggiero, Alessandro G.

    1993-01-01

    Full text: Particle beam stability is crucial to any accelerator or collider, particularly big ones, such as Brookhaven's RHIC heavy ion collider and the larger SSC and LHC proton collider schemes. A workshop on the Stability of Particle Motion in Storage Rings held at Brookhaven in October dealt with the important issue of determining the short- and long-term stability of single particle motion in hadron storage rings and colliders, and explored new methods for ensuring it. In the quest for realistic environments, the imperfections of superconducting magnets and the effects of field modulation and noise were taken into account. The workshop was divided into three study groups: Short-Term Stability in storage rings, including chromatic and geometric effects and correction strategies; Long-Term Stability, including modulation and random noise effects and slow varying effects; and Methods for determining the stability of particle motion. The first two were run in parallel, but the third was attended by everyone. Each group considered analytical, computational and experimental methods, reviewing work done so far, comparing results and approaches and underlining outstanding issues. By resolving conflicts, it was possible to identify problems of common interest. The workshop reaffirmed the validity of methods proposed several years ago. Major breakthroughs have been in the rapid improvement of computer capacity and speed, in the development of more sophisticated mathematical packages, and in the introduction of more powerful analytic approaches. In a typical storage ring, a particle may be required to circulate for about a billion revolutions. While ten years ago it was only possible to predict accurately stability over about a thousand revolutions, it is now possible to predict over as many as one million turns. If this trend continues, in ten years it could become feasible to predict particle stability over the entire storage period. About ninety participants

  14. Plasma particle accelerators

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1988-01-01

    The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs

  15. Composite magnetic particles

    International Nuclear Information System (INIS)

    Davies, G.E.; Janata, J.

    1981-01-01

    This patent claim on behalf of I.C.I. Ltd., relates to the preparation and use of composite magnetic particles, comprising a low density core, and having a magnetic coating over at least a proportion of the surface. The density of such particles can be chosen to suit a range of applications, e.g. in affinity chromatography, in radioimmunoassay, in the transport of the associated component, such as a drug or enzyme, to a specific site in a living organism. (U.K.)

  16. Overview of particle physics

    International Nuclear Information System (INIS)

    Salam, A.

    1993-01-01

    This article presents an overview of the situation in particle physics and a prognosis of its future: ideas which have been tested or will soon be tested (standard model and the light Higgs particle), ideas whose time has not yet come (supersymmetry, supersymmetry and N=1 supergravity, right-left symmetry and preons, unification of gravity with other forces, anomaly-free supergravities, supersymmetry strings, string theory as the ''Theory of Everything'' (T.O.E.); passive and non accelerator experiments. 6 figs., 2 tabs

  17. Collection of particles

    International Nuclear Information System (INIS)

    Frew, J.D.

    1979-01-01

    Apparatus and a method for collecting particles formed by vaporisation during a high temperature treatment of steel (eg cutting or welding) are described in which gas is drawn from the area in which the treatment is taking place through a collector in which the particles are separated magnetically. The air may be drawn by an air ejector from a hood around the treatment area. The invention has particular application where the high temperature treatment is the laser cutting of the stainless steel wrapper around a nuclear fuel sub-assembly. (author)

  18. The paradox particle

    Energy Technology Data Exchange (ETDEWEB)

    Sutton, Christine

    1993-11-15

    As well as being a leading physics writer, Christine Sutton of Oxford is also a particle physicist, currently working on the Zeus experiment at DESY's HERA electron-proton collider. Her latest book ''Spaceship Neutrino'' Cambridge University Press ISBN 0 521 36404 3 [hardback] or 0 521 36703 4 [paperback]) is a fascinating account of the emergence of the neutrino on the stage of science. In sixty years, the neutrino has been transformed from an apologetic idea its originator dared not publish to one of the main experimental tools of modern high energy research, while cosmologists have realized that this bizarre particle could play a major role in the Universe.

  19. Beta particle measurement fundamentals

    International Nuclear Information System (INIS)

    Alvarez, J.L.

    1986-01-01

    The necessary concepts for understanding beta particle behavior are stopping power, range, and scattering. Dose as a consequence of beta particle interaction with tissue can be derived and explained by these concepts. Any calculations of dose, however, assume or require detailed knowledge of the beta spectrum at the tissue depth of calculation. A rudimentary knowledge of the incident spectrum can be of use in estimating dose, interpretating dose measuring devices and designing protection. The stopping power and range based on the csda will give a conservative estimate in cases of protection design, as scattering will reduce the range. Estimates of dose may be low because scattering effects were neglected

  20. Particles and forces

    International Nuclear Information System (INIS)

    Peierls, R.

    1981-01-01

    The particles and forces of matter, found in the Universe, are discussed with especial reference to some of the laws which govern behaviour in the sub-atomic world and which determine the way forces work to give matter its various characteristics. The recent history of the search for elementary constituents of matter in this century is outlined and the replacement of the simplicity anticipated in the 1930s by the proliferation of particle states uncovered in the 1950s and 1960s which led to the quark model is examined. (U.K.)

  1. Single particle detecting telescope system

    International Nuclear Information System (INIS)

    Yamamoto, I.; Tomiyama, T.; Iga, Y.; Komatsubara, T.; Kanada, M.; Yamashita, Y.; Wada, T.; Furukawa, S.

    1981-01-01

    We constructed the single particle detecting telescope system for detecting a fractionally charged particle. The telescope consists of position detecting counters, wall-less multi-cell chambers, single detecting circuits and microcomputer system as data I/0 processor. Especially, a frequency of double particle is compared the case of the single particle detecting with the case of an ordinary measurement

  2. Amorphous silicon ionizing particle detectors

    Science.gov (United States)

    Street, Robert A.; Mendez, Victor P.; Kaplan, Selig N.

    1988-01-01

    Amorphous silicon ionizing particle detectors having a hydrogenated amorphous silicon (a--Si:H) thin film deposited via plasma assisted chemical vapor deposition techniques are utilized to detect the presence, position and counting of high energy ionizing particles, such as electrons, x-rays, alpha particles, beta particles and gamma radiation.

  3. New particle searches and discoveries

    International Nuclear Information System (INIS)

    Trippe, T.G.; Barbaro-Galtieri, A.; Horne, C.P.; Kelly, R.L.; Rittenberg, A.; Rosenfeld, A.H.; Yost, G.P.; Armstrong, B.; Bricman, C.; Hemingway, R.J.; Losty, M.J.; Roos, M.

    1977-01-01

    This supplement to the 1976 edition of 'Review of particle properties', Particle Data Group [Rev. Mod. Phys. 48, No. 2, Part II (1976)], contains tabulations of experimental data bearing on the 'new particles' and related topics; categories covered include charmed particles, psi's and their decay products, and heavy leptons. Errata to the previous edition are also given. (Auth.)

  4. Department of Particle Theory - Overview

    International Nuclear Information System (INIS)

    Jezabek, M.

    1999-01-01

    Full text: Research performed at the Department of Particle Theory is devoted to fundamental particles and their interactions. These studies are closely related to the current and future high energy experiments at e + e - and hadron-hadron colliders: LEP, TESLA, Tevatron and LHC. The papers reported below cover a wide range of particle physics from neutrino masses and oscillations to processes involving heavy particles like gauge and Higgs bosons or the top quark. An evidence of neutrino oscillations observed by the SuperKamiokande Collaboration was the most spectacular discovery of the year 1998. In a theoretical investigation performed at our department a relation has been found between the so called see-saw mechanism and the bi-maximal neutrino mixing. Since many years a very important and labour-consuming part of the research activities is related to precision tests of the Standard Model. In the last year successful runs of LEP2 stimulated an impressive progress in theoretical description of processes with two- and four-fermion final states in electron-positron annihilation. It is worth stressing that the results of the calculations have been distributed in the form of the computer programs (Monte Carlo and other types) which serve as an indispensable tool in the analysis of the experimental data. Although the whole scientific program is a natural continuation of the activities started earlier a few results obtained in the last year should be mentioned: Publication of the four-fermion Monte Carlo program KORALW for high energy e + e - colliders; Development of the exponentiation scheme at the spin amplitude level and studies of the anomalous couplings for the e + e - → f (anti)f (nγ) processes; Relation between QCD static potentials in momentum and position spaces, and its consequences for bottom and top quark pair production and spectroscopy; Participation in the preparation of the physics program of the pp experiments on LHC collider particularly for Higgs

  5. Personal exposure to ultrafine particles.

    Science.gov (United States)

    Wallace, Lance; Ott, Wayne

    2011-01-01

    Personal exposure to ultrafine particles (UFP) can occur while people are cooking, driving, smoking, operating small appliances such as hair dryers, or eating out in restaurants. These exposures can often be higher than outdoor concentrations. For 3 years, portable monitors were employed in homes, cars, and restaurants. More than 300 measurement periods in several homes were documented, along with 25 h of driving two cars, and 22 visits to restaurants. Cooking on gas or electric stoves and electric toaster ovens was a major source of UFP, with peak personal exposures often exceeding 100,000 particles/cm³ and estimated emission rates in the neighborhood of 10¹² particles/min. Other common sources of high UFP exposures were cigarettes, a vented gas clothes dryer, an air popcorn popper, candles, an electric mixer, a toaster, a hair dryer, a curling iron, and a steam iron. Relatively low indoor UFP emissions were noted for a fireplace, several space heaters, and a laser printer. Driving resulted in moderate exposures averaging about 30,000 particles/cm³ in each of two cars driven on 17 trips on major highways on the East and West Coasts. Most of the restaurants visited maintained consistently high levels of 50,000-200,000 particles/cm³ for the entire length of the meal. The indoor/outdoor ratios of size-resolved UFP were much lower than for PM₂.₅ or PM₁₀, suggesting that outdoor UFP have difficulty in penetrating a home. This in turn implies that outdoor concentrations of UFP have only a moderate effect on personal exposures if indoor sources are present. A time-weighted scenario suggests that for typical suburban nonsmoker lifestyles, indoor sources provide about 47% and outdoor sources about 36% of total daily UFP exposure and in-vehicle exposures add the remainder (17%). However, the effect of one smoker in the home results in an overwhelming increase in the importance of indoor sources (77% of the total).

  6. Effect of heavy particles in low-energy light-particle processes

    International Nuclear Information System (INIS)

    Chan, L.H.; Hagiwara, T.; Ovrut, B.

    1979-01-01

    The ''decoupling theorem'' of Appelquist and Carazzone is found not always to be applicable to light-scalar-particle processes in spontaneously broken theories. If the Higgs scalar is considered to be light, then Higgs-scalar processes see the effect of heavy fermions and heavy vector gauge bosons at the one-loop level. If there is more than one scalar multiplet in a spontaneously broken gauge theory, the effect of a heavy Higgs particle in light-scalar-particle processes is significant at the tree level. In the latter case, such an effect can be absorbed completely into an effective phi 4 coupling constant, lambda/sub eff/, of the light particle provided that lambda/sub eff/ is positive definite

  7. Optimizing parameter of particle damping based on Leidenfrost effect of particle flows

    Science.gov (United States)

    Lei, Xiaofei; Wu, Chengjun; Chen, Peng

    2018-05-01

    Particle damping (PD) has strongly nonlinearity. With sufficiently vigorous vibration conditions, it always plays excellent damping performance and the particles which are filled into cavity are on Leidenfrost state considered in particle flow theory. For investigating the interesting phenomenon, the damping effect of PD on this state is discussed by the developed numerical model which is established based on principle of gas and solid. Furtherly, the numerical model is reformed and applied to study the relationship of Leidenfrost velocity with characteristic parameters of PD such as particle density, diameter, mass packing ratio and diameter-length ratio. The results indicate that particle density and mass packing ratio can drastically improve the damping performance as opposed as particle diameter and diameter-length ratio, mass packing ratio and diameter-length ratio can low the excited intensity for Leidenfrost state. For discussing the application of the phenomenon in engineering, bound optimization by quadratic approximation (BOBYQA) method is employed to optimize mass packing ratio of PD for minimize maximum amplitude (MMA) and minimize total vibration level (MTVL). It is noted that the particle damping can drastically reduce the vibrating amplitude for MMA as Leidenfrost velocity equal to the vibrating velocity relative to maximum vibration amplitude. For MTVL, larger mass packing ratio is best option because particles at relatively wide frequency range is adjacent to Leidenfrost state.

  8. Radiation level measured by a portable Geiger-Mueller counter at the altitude of commercial air routes

    International Nuclear Information System (INIS)

    Araki, Takashi

    1995-01-01

    The background intensities of naturally occurring radiation were measured aboard scheduled commercial airplanes using a newly developed Geiger-Mueller counter with a pocket computer. The preliminary results show that the radiation at the cruising altitude of a commercial airplane on a transcontinental flight is 40 times higher than the ground-level. (author)

  9. Exposure to electromagnetic fields aboard high-speed electric multiple unit trains.

    Science.gov (United States)

    Niu, D; Zhu, F; Qiu, R; Niu, Q

    2016-01-01

    High-speed electric multiple unit (EMU) trains generate high-frequency electric fields, low-frequency magnetic fields, and high-frequency wideband electromagnetic emissions when running. Potential human health concerns arise because the electromagnetic disturbances are transmitted mainly into the car body from windows, and from there to passengers and train staff. The transmission amount and amplitude distribution characteristics that dominate electromagnetic field emission need to be studied, and the exposure level of electromagnetic field emission to humans should be measured. We conducted a series of tests of the on board electromagnetic field distribution on several high-speed railway lines. While results showed that exposure was within permitted levels, the possibility of long-term health effects should be investigated.

  10. Measurements with the PNNL Density Sensor aboard the Essayons, July 2009

    International Nuclear Information System (INIS)

    Greenwood, Margaret S.

    2009-01-01

    Report of the measurements and analysis of the density data. On July 9, 2009, the Pacific Northwest National Laboratory (PNNL) ultrasonic sensor obtained density data for the sand slurry dredged near the mouth of the Columbia River by the Essayons. The objective of these measurements was to compare the data from the ultrasonic sensor with that obtained by the radioactive sensor, currently in use. The U. S. Corps of Engineers is interested in a sensor technology capable of competing with the radioactive sensor to ease regulatory concerns. The average density obtained during the data acquisition was smaller than the expected value of 1.3 g/cm3. Further investigation showed that the radioactive sensor measured a density of 1.11 g/cm3 for the calibration liquid, but the code was set up with the density of seawater of 1.025 g/cm3. This mismatch partially explained the low density value. However, the conclusion was that, while the basic data is very good, the current interpretation of that data needed modification. A new model has been developed that describes how the ultrasound interacts with the sand particles in the slurry. The new model requires the evaluation of a constant ksurf from a laboratory experiment. This was carried out at PNNL using sand obtained from the Oregon coast during a previous visit to the Essayons. A value for ksurf was determined with an error of ±10%, which, of course, is too large. For future work, another design is proposed and a more accurate value is expected. Measurements with the refractometer showed the effects of tides. That is, in the morning the density of the seawater was very close to that for fresh water, while in the afternoon, the density was due to salt water. The results of the analysis showed that the average density of the sand slurry varies between 1.230 and 1.235 g/cm3. The last section of this report discusses in detail improvements for future development. The conclusion is that, once these improvements have been made

  11. Measurement of OCS, CO2, CO and H2O aboard NASA's WB-57 High Altitude Platform Using Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS)

    Science.gov (United States)

    Leen, J. B.; Owano, T. G.; Du, X.; Gardner, A.; Gupta, M.

    2014-12-01

    Carbonyl sulfide (OCS) is the most abundant sulfur gas in the atmosphere and has been implicated in controlling the sulfur budget and aerosol loading of the stratosphere. In the troposphere, OCS is irreversibly consumed during photosynthesis and may serve as a tracer for gross primary production (GPP). Its primary sources are ocean outgassing, industrial processes, and biomass burning. Its primary sinks are vegetation and soils. Despite the importance of OCS in atmospheric processes, the OCS atmospheric budget is poorly determined and has high uncertainty. OCS is typically monitored using either canisters analyzed by gas chromatography or integrated atmospheric column measurements. Improved in-situ terrestrial flux and airborne measurements are required to constrain the OCS budget and further elucidate its role in stratospheric aerosol formation and as a tracer for biogenic volatile organics and photosynthesis. Los Gatos Research has developed a flight capable mid-infrared Off-Axis Integrated Cavity Output Spectroscopy (OA-ICOS) analyzer to simultaneously quantify OCS, CO2, CO, and H2O in ambient air at up to 2 Hz. The prototype was tested on diluted, certified samples and found to be precise (OCS, CO2, CO, and H2O to better than ±4 ppt, ±0.2 ppm, ±0.31 ppb, and ±3.7 ppm respectively, 1s in 1 sec) and linear (R2 > 0.9997 for all gases) over a wide dynamic range (OCS, CO2, CO, and H2O ranging from 0.2 - 70 ppb, 500 - 3000 ppm, 150 - 480 ppb, and 7000 - 21000 ppm respectively). Cross-interference measurements showed no appreciable change in measured OCS concentration with variations in CO2 (500 - 3500 ppm) or CO. We report on high altitude measurements made aboard NASA's WB-57 research aircraft. Two research flights were conducted from Houston, TX. The concentration of OCS, CO2, CO, and H2O were continuously recorded from sea level to approximately 60,000 feet. The concentration of OCS was observed to increase with altitude through the troposphere due to the

  12. Matter: the fundamental particles

    CERN Multimedia

    Landua, Rolf

    2007-01-01

    "The largest particle physics centre in the world is located in Europe. It straddles the Franco-Swiss border, near Geneva. At CERN - the European Organisation for Nuclear Research , which is focused on the science of nuclear matter rather than on the exploitation of atomic energy - there are over 6 500 scientists." (1 page)

  13. Our Particle Universe

    Indian Academy of Sciences (India)

    and “why is the universe the way it is?” Not long before ... to each other. The interactions of particles in the universe ... theory by Jean Perrin in 1908 convinced people that atoms and ..... ing the origin and evolution of our universe13. This is an ...

  14. Elementary particle interactions

    International Nuclear Information System (INIS)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Ward, B.F.L.; Close, F.E.; Christophorou, L.G.

    1990-10-01

    This report discusses freon bubble chamber experiments exposed to μ + and neutrinos, photon-proton interactions; shower counter simulations; SLD detectors at the Stanford Linear Collider, and the detectors at the Superconducting Super Collider; elementary particle interactions; physical properties of dielectric materials used in High Energy Physics detectors; and Nuclear Physics

  15. Particle physics and cosmology

    International Nuclear Information System (INIS)

    Ellis, J.; Nanopoulos, D.

    1983-01-01

    The authors describe the connection between cosmology and particle physics in an introductory way. In this connection the big bang theory and unified gauge models of strong, electromagnetic, and weak interactions are considered. Furthermore cosmological nucleosynthesis is discussed in this framework, and the problem of cosmic neutrinos is considered with special regards to its rest mass. (HSI).

  16. Charged particle beams

    CERN Document Server

    Humphries, Stanley

    2013-01-01

    Detailed enough for a text and sufficiently comprehensive for a reference, this volume addresses topics vital to understanding high-power accelerators and high-brightness-charged particle beams. Subjects include stochastic cooling, high-brightness injectors, and the free electron laser. Humphries provides students with the critical skills necessary for the problem-solving insights unique to collective physics problems. 1990 edition.

  17. Lord of the particles

    CERN Multimedia

    Loll, Anna-Cathrin

    2009-01-01

    "Rolf-Dieter Heuer is the new director general of the world's largest particle physics research center. Though the German physicist never expected to gain this influential position in Switzerland, it seems a natural step in his career trajectory" (1.5 pages)

  18. Particle physics experiments 1982

    International Nuclear Information System (INIS)

    Rousseau, M.D.; Stuart, G.

    1983-01-01

    Work carried out in 1982 on 52 experiments approved by the Particle Physics Experiments Selection Panel is described. Each experiment is listed under title, collaboration, technique, accelerator, year of running, status and spokesman. Unedited contributions are given from each experiment. (U.K.)

  19. Energetic solar particles

    International Nuclear Information System (INIS)

    Biswas, M.

    1975-01-01

    In this review, some of the important aspects of energetic solar particles and their relation to solar physics are discussed. The major aspects of solar cosmic ray studies currently under investigation are identified and attention is focussed on the problems of the physical processes in the sun which may be responsible for these phenomena. The studies of the composition and energy spectra of solar cosmic ray nuclei are related to the basic problem of particle acceleration process in sun and to the composition of elements in solar atmosphere. The composition of higher energy (>20 MeV/amu) multiply charged nuclei of He, C, N, O, Ne, Mg, Si and Fe give information on the abundance of elements in the solar atmosphere. At lower energies (approximately 1-10 MeV/amu), the abundances of these elements show enhancements relative to solar abundances and these enhancements are believed to be due to particle acceleration mechanisms operative in the sun which are not fully understood at present. Studies of the relative abundances of H 2 , H 3 and He 3 isotopes and Li, Be, B nuclei in the solar cosmic rays can also be studied. The question of the relationship of the accelerated particles in the sun to the optical flare phenomena is discussed. Further studies of different aspects of these phenomena may give important clues to a wide ranging phenomena in the active sun. The observational methods employed for these studies are mentioned. (A.K.)

  20. Exotic Long - Lived Particles

    CERN Document Server

    Jørgensen, Morten Dam

    A search for hadronising long-lived massive particles at the Large Hadron Collider is conducted with the ATLAS detector. No excess events are found. Based on statistical analysis, upper limits on the production cross section are observed to be between $0.01$ pb and $0.006$ pb for colour octet particles (gluinos) with masses ranging from $300 \\ \\mathrm{GeV/c}^2$ to $1400 \\ \\mathrm{GeV/c}^2$, and $0.01$ pb to $0.004$ pb for colour triplet particles (stops and sbottoms) with masses ranging from $200 \\ \\mathrm{GeV/c}^2$ to $900 \\ \\mathrm{GeV/c}^2$. In the context of Supersymmetry with decoupled sfermion and sboson sectors (Split-SUSY), this gives a lower limit on the gluino mass of $989 \\ \\mathrm{GeV/c}^2$, and $683 \\ \\mathrm{GeV/c}^2$ for the stop mass and $618 \\ \\mathrm{GeV/c}^2$ for the sbottom mass. In addition, a new method is presented that improves the speed ($\\beta$) estimation for long-lived particles in the ATLAS tile calorimeter with a factor of $7$ improvement in resolution at low-$\\beta$ and ...