WorldWideScience

Sample records for cascade showers

  1. Time structure of cascade showers

    International Nuclear Information System (INIS)

    Nakatsuka, Takao

    1984-01-01

    Interesting results have been reported on the time structure of the electromagnetic components of air showers which have been obtained by using recent fast electronic circuit technology. However, these analyses and explanations seem not very persuasive. One of the reasons is that there is not satisfactory theoretical calculation yet to explain the delay of electromagnetic components in cascade processes which are the object of direct observation. Therefore, Monte Carlo calculation was attempted for examining the relationship between the altitude at which high energy γ-ray is generated up in the air and the time structure of cascade showers at the level of observation. The investigation of a dominant factor over the delay of electromagnetic components indicated that the delay due to the multiple scattering of electrons was essential. The author used the analytical solution found by himself of C. N. Yang's equation for the study on the delay due to multiple scattering. The results were as follows: The average delay time and the spread of distribution of electromagnetic cascades were approximately in linear relationship with the mass of a material having passed in a thin uniform medium; the rise time of arrival time distribution for electromagnetic cascade showers was very steep under the condition that they were generated up in the air and observed on the ground; the subpeaks delayed by tens of ns in arrival time may sometimes appear due to the perturbation in electromagnetic cascade processes. (Wakatsuki, Y.)

  2. Techniques for detecting the Cherenkov light from cascade showers in water

    Science.gov (United States)

    Khomyakov, V. A.; Bogdanov, A. G.; Kindin, V. V.; Kokoulin, R. P.; Petrukhin, A. A.; Khokhlov, S. S.; Shutenko, V. V.; Yashin, I. I.

    2018-01-01

    The NEVOD Cherenkov water detector (CWD) features a denser lattice of sensitive elements than the existing large-scale CWDs, whereby the spatial distribution of Cherenkov light from cascade showers is sampled with a superior resolution of 0.5 m, which is close to one radiation length for water (36 cm). The experimental techniques for investigating the Cherenkov light generated by particle cascades in water is proposed. The dependence of light intensity on the depth of shower development is for the first time measured at different distances from the shower axis. The results are compared with the Cherenkov light distributions predicted by various model descriptions for the scattering of cascade particles.

  3. Monte-Carlo calculation and comparison with experimental data of cascade curves and fluctuations of mean number of shower particles initiated by γ-quanta in liquid xenon

    International Nuclear Information System (INIS)

    Vrotnyak, Ya.; Strugal'skij, Z.; Yablonskij, Z.

    1976-01-01

    The cascade curves and corresponding fluctuations of the numbers of shower particles are evaluated, using the Monte-Carlo calculation method, for showers initiated by gamma quanta of energies from 20 to 2000 MeV in liquid xenon. While making the calculation program, processes of electron-positron pair production, the compton effect, bremsstrahlung radiation of secondary photons by electrons and ionization losses of electrons were taken into consideration. The multiple Coulomb scattering and escape angles of particles were not taken into account in the model. The calculation program is performed in a variant providing calculations of shower parameters for any substance. The following values have been calculated: distribution of the number of particles with the depth, distribution of the energy of shower particles with the depth, mean number of particles with the depth, and the standard deviation. The calculation results for electrons are compared with experimental data. The calculation provides a correct position of maxima of particles and that of number of particles at the depth, shower tails exclusive

  4. Comparison of hybrid and pure Monte Carlo shower generators on an event by event basis

    OpenAIRE

    Allen, Jeff; Drescher, Hans-Joachim; Farrar, Glennys

    2007-01-01

    SENECA is a hybrid air shower simulation written by H. Drescher that utilizes both Monte Carlo simulation and cascade equations. By using the cascade equations only in the high energy portion of the shower, where the shower is inherently one-dimensional, SENECA is able to utilize the advantages in speed from the cascade equations yet still produce complete, three dimensional particle distributions at ground level which capture the shower to shower variations coming from the early interactions...

  5. Meteor Showers.

    Science.gov (United States)

    Kronk, Gary W.

    1988-01-01

    Described are the history, formation, and observing techniques of meteors and comets. Provided are several pictures, diagrams, meteor organizations and publications, and meteor shower observation tables. (YP)

  6. EGS code system: computer programs for the Monte Carlo simulation of electromagnetic cascade showers. Version 3. [EGS, PEGS, TESTSR, in MORTRAN

    Energy Technology Data Exchange (ETDEWEB)

    Ford, R.L.; Nelson, W.R.

    1978-06-01

    A code to simulate almost any electron--photon transport problem conceivable is described. The report begins with a lengthy historical introduction and a description of the shower generation process. Then the detailed physics of the shower processes and the methods used to simulate them are presented. Ideas of sampling theory, transport techniques, particle interactions in general, and programing details are discussed. Next, EGS calculations and various experiments and other Monte Carlo results are compared. The remainder of the report consists of user manuals for EGS, PEGS, and TESTSR codes; options, input specifications, and typical output are included. 38 figures, 12 tables. (RWR)

  7. Structure of air shower disc near the core

    International Nuclear Information System (INIS)

    Inoue, N.; Kawamoto, M.; Misaki, Y.; Maeda, T.; Takeuchi, T.; Toyoda, Y.

    1985-01-01

    The longitudinal structure of the air shower disk is studied by measuring the arrival time distributions of air shower particles for showers with electron size in the range 3.2 x 10 to the 5.5. power to 3.2 x 10 to the 7.5 power in the Akeno air-shower array (930 gcm squared atmospheric depth). The average FWHM as a parameter of thickness of air shower disk increases with core distances at less than 50m. At the present stage, dependence on electron size, zenith angle and air shower age is not apparent. The average thickness of the air shower disk within a core distance of 50m could be determined by an electromagnetic cascade starting from the lower altitude

  8. A new way of air shower detection: measuring the properties of cosmic rays with LOFAR

    NARCIS (Netherlands)

    Nelles, A.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Rachen, J. P.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, T.N.G.

    2015-01-01

    High-energy cosmic rays impinging onto the atmosphere of the Earth initiate cascades of secondary particles: extensive air showers. Many of the particles in a shower are electrons and positrons. During the development of the air shower and by interacting with the geomagnetic field, the

  9. Electromagnetic pulses from high-energy showers: Implications for neutrino detection

    International Nuclear Information System (INIS)

    Zas, E.; Halzen, F.; Stanev, T.

    1992-01-01

    We review the properties of electromagnetic showers in dense media and calculate in detail the associated electromagnetic pulses generated by shower electrons. We perform real-time simulations recording the charge, trajectory, and time of each cascade particle and compute the associated electromagnetic wave. Our results are relevant to experiments detecting radio pulses from showers initiated by cosmic particles interacting with the Earth

  10. Fractal Electromagnetic Showers

    OpenAIRE

    Anchordoqui, L. A.; Kirasirova, M.; McCauley, T. P.; Paul, T.; Reucroft, S.; Swain, J. D.

    2000-01-01

    We study the self-similar structure of electromagnetic showers and introduce the notion of the fractal dimension of a shower. Studies underway of showers in various materials and at various energies are presented, and the range over which the fractal scaling behaviour is observed is discussed. Applications to fast shower simulations and identification, particularly in the context of extensive air showers, are also discussed.

  11. An air shower array for LOFAR: LORA

    NARCIS (Netherlands)

    Thoudam, S.; Aar, G. V.; Akker, M. V. D.; Bähren, L.; Corstanje, A.; Falcke, H.; Hörandel, J. R.; Horneffer, A.; James, C.; Mevius, M.; Scholten, O.; Singh, K.; Ter Veen, S.

    2011-01-01

    LOFAR is a new form of radio telescope which can detect radio emission from air showers induced by very high-energy cosmic rays. It can also look for radio emission from particle cascades on the Moon induced by ultra high-energy cosmic rays or neutrinos. To complement the radio detection, we are

  12. Extensive Air Showers: from the muonic smoking guns to the hadronic backbone

    Directory of Open Access Journals (Sweden)

    Cazon L.

    2013-06-01

    Full Text Available Extensive Air Showers are complex macroscopic objects initiated by single ultra-high energy particles. They are the result of millions of high energy reactions in the atmosphere and can be described as the superposition of hadronic and electromagnetic cascades. The hadronic cascade is the air shower backbone, and it is mainly made of pions. Decays of neutral pions initiate electromagnetic cascades, while the decays of charged pions produce muons which leave the hadronic core and travel many kilometers almost unaffected. Muons are smoking guns of the hadronic cascade: the energy, transverse momentum, spatial distribution and depth of production are key to reconstruct the history of the air shower. In this work, we overview the phenomenology of muons on the air shower and its relation to the hadronic cascade. We briefly review the experimental efforts to analyze muons within air showers and discuss possible paths to use this information.

  13. The Vincia parton shower

    NARCIS (Netherlands)

    Giele, W.T.; Hartgring, L.; Kosower, D.A.; Laenen, E.L.M.P.; Larkoski, A.J.; Lopez-Villarejo, J.; Ritzmann, M.; Skands, P.

    2013-01-01

    We summarize recent developments in the VINCIA parton shower. After a brief review of the basics of the formalism, the extension of VINCIA to hadron collisions is sketched. We then turn to improvements of the efficiency of tree-level matching by making the shower history unique and by incorporating

  14. Shower counter resolution scaling

    International Nuclear Information System (INIS)

    Kirk, T.B.W.

    1991-01-01

    The EM shower counter for the SDC detector has a resolution expression containing two stochastic terms plus a constant term. Recent measurements clarifying the sources of these terms are presented here. 3 refs., 4 figs

  15. On hadronic shower simulation

    CERN Document Server

    Wellisch, J P

    1999-01-01

    The exploitation of hadronic final states played a key role in the successes of all recent HEP collider experiments, and the ability to use the hadronic final state will continue to be one of the decisive issues during the LHC era. Monte Carlo techniques to make efficient use of hadronic final states have been developed for many years, and have a technological culmination in object oriented tool-kits for hadronic shower simulation that now are becoming available. In the present paper we give a brief overview on the physics modeling underlying hadronic shower simulation, and report on advanced techniques used and developed for simulation of hadronic showers in HEP experiments. We will discuss the three basic types of modelling - data driven, parametrisation driven, and theory driven modelling - and demonstrate ways to combine them in a flexible manner for concrete applications. We will confront the different types of modelling with the stringent requirements on hadronic shower simulation posed by LHC, and inve...

  16. The CASTOR shower library

    International Nuclear Information System (INIS)

    Mundim Filho, Luiz Martins; Carvalho, Wagner de Paula

    2012-01-01

    Full text: CASTOR (Centaur And Strange Object Research) is an electromagnetic (EM) and hadronic (HAD) calorimeter, based on tungsten and quartz plates, operating in the CMS Detector (Compact Muon Solenoid) at LHC. The calorimeter detects Cerenkov radiation and is positioned around the beam pipe in the very forward region of CMS (at 14.38 m from the interaction point), covering the pseudo-rapidity range between -6.6 ≤ η≤-5.1 . It is longitudinally segmented into 14 sections, 2 for the EM and 12 for the HAD parts and is 16-fold azimuthally symmetric around the beam pipe. A Shower Library is needed for CASTOR Monte Carlo simulation, as the full simulation of showers takes a long time and the high multiplicity of particles in the forward region makes this simulation very time consuming. The Shower Library is used as a look-up table in the form of a ROOT file, so that when a simulated particle enters the detector with a certain energy and direction, characterized by the azimuthal angle φ and the pseudo-rapidity η, instead of making the full simulation of the shower in CASTOR, it is substituted by one already stored in the Shower Library. Showers corresponding to two types of particles are included in the Shower Library: electrons (or photons) and charged pions. The software implemented to make the Shower Library is described, as well as the validation of this library and timing studies. This package has been developed in the context of the official software of the CMS Collaboration, CMSSW. (author)

  17. Biofilms in shower hoses.

    Science.gov (United States)

    Proctor, Caitlin R; Reimann, Mauro; Vriens, Bas; Hammes, Frederik

    2017-12-14

    Shower hoses offer an excellent bacterial growth environment in close proximity to a critical end-user exposure route within building drinking water plumbing. However, the health risks associated with and processes underlying the development of biofilms in shower hoses are poorly studied. In a global survey, biofilms from 78 shower hoses from 11 countries were characterized in terms of cell concentration (4.1 × 10 4 -5.8 × 10 8  cells/cm 2 ), metal accumulation (including iron, lead, and copper), and microbiome composition (including presence of potential opportunistic pathogens). In countries using disinfectant, biofilms had on average lower cell concentrations and diversity. Metal accumulation (up to 5 μg-Fe/cm 2 , 75 ng-Pb/cm 2 , and 460 ng-Cu/cm 2 ) seemed to be partially responsible for discoloration in biofilms, and likely originated from other pipes upstream in the building. While some genera that may contain potential opportunistic pathogens (Legionella, detected in 21/78 shower hoses) were positively correlated with biofilm cell concentration, others (Mycobacterium, Pseudomonas) had surprisingly non-existent or negative correlations with biofilm cell concentrations. In a controlled study, 15 identical shower hoses were installed for the same time period in the same country, and both stagnant and flowing water samples were collected. Ecological theory of dispersal and selection helped to explain microbiome composition and diversity of different sample types. Shower hose age was related to metal accumulation but not biofilm cell concentration, while frequency of use appeared to influence biofilm cell concentration. This study shows that shower hose biofilms are clearly a critical element of building drinking water plumbing, and a potential target for building drinking water plumbing monitoring. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Time-dependent intranuclear cascade model

    International Nuclear Information System (INIS)

    Barashenkov, V.S.; Kostenko, B.F.; Zadorogny, A.M.

    1980-01-01

    An intranuclear cascade model with explicit consideration of the time coordinate in the Monte Carlo simulation of the development of a cascade particle shower has been considered. Calculations have been performed using a diffuse nuclear boundary without any step approximation of the density distribution. Changes in the properties of the target nucleus during the cascade development have been taken into account. The results of these calculations have been compared with experiment and with the data which had been obtained by means of a time-independent cascade model. The consideration of time improved agreement between experiment and theory particularly for high-energy shower particles; however, for low-energy cascade particles (with grey and black tracks in photoemulsion) a discrepancy remains at T >= 10 GeV. (orig.)

  19. Some dipole shower studies

    Science.gov (United States)

    Cabouat, Baptiste; Sjöstrand, Torbjörn

    2018-03-01

    Parton showers have become a standard component in the description of high-energy collisions. Nowadays most final-state ones are of the dipole character, wherein a pair of partons branches into three, with energy and momentum preserved inside this subsystem. For initial-state showers a dipole picture is also possible and commonly used, but the older global-recoil strategy remains a valid alternative, wherein larger groups of partons share the energy-momentum preservation task. In this article we introduce and implement a dipole picture also for initial-state radiation in Pythia, and compare with the existing global-recoil one, and with data. For the case of Deeply Inelastic Scattering we can directly compare with matrix element expressions and show that the dipole picture gives a very good description over the whole phase space, at least for the first branching.

  20. Portable shower apparatus

    Science.gov (United States)

    Grenier, Francis E. (Inventor)

    1993-01-01

    A multipurpose, collapsible, shower apparatus for use almost anywhere but especially adapted for use in places somewhat remote from civilization such as recreational vehicles, campers, the outdoors, space vehicles and the like where there may be a limited amount of water or other liquid. The collapsible shower apparatus includes a curtain assembly having an inner wall, an outer wall and a porous element for separating the inner and outer walls; a series of spaced hollow hoops connected by one or more sets of hollow tubes (manifolds); one or more nozzles connected to and in communication with at least one of the hollow hoops; a source of fluid under pressure in communication with at least one of the hollow hoops; and a suction pump for withdrawing fluid from the interior of the curtain assembly.

  1. Extensive air showers

    CERN Document Server

    Rao, M V S

    1997-01-01

    Ultrahigh energy cosmic rays carry information about their sources and the intervening medium apart from providing a beam of particles for studying certain features of high energy interactions currently inaccessible at man-made accelerators. They can at present be studied only via the extensive air showers (EAS's) they generate while passing through the Earth's atmosphere, since their fluxes are too low for the experiments of limited capability flown in balloons and satellites. The EAS is generated by a series of interactions of the primary cosmic ray and its progeny with the atmospheric nucle

  2. Air shower density spectrum

    Science.gov (United States)

    Porter, M. R.; Foster, J. M.; Hodson, A. L.; Hazen, W. E.; Hendel, A. Z.; Bull, R. M.

    Results are presented of a measurement of the differential local density spectrum of extensive air showers at sea level using 1 sq m current-limited spark chambers. The 2 cm gap, Ne/He-filled discharge chambers with 6 mm thick 'Georgia-wired' glass faces, were mounted directly on the underside of a light, uniform, sandwich-panel roof. Separate runs with different trigger requirements were made. Low density spectra according to different counting criteria are presented in a graph. Another graph shows a differential local density spectrum. The results of the measurements are compared with previous measurements

  3. Hadron cascades produced by electromagnetic cascades

    International Nuclear Information System (INIS)

    Nelson, W.R.; Jenkins, T.M.; Ranft, J.

    1986-12-01

    A method for calculating high energy hadron cascades induced by multi-GeV electron and photon beams is described. Using the EGS4 computer program, high energy photons in the EM shower are allowed to interact hadronically according to the vector meson dominance (VMD) model, facilitated by a Monte Carlo version of the dual multistring fragmentation model which is used in the hadron cascade code FLUKA. The results of this calculation compare very favorably with experimental data on hadron production in photon-proton collisions and on the hadron production by electron beams on targets (i.e., yields in secondary particle beam lines). Electron beam induced hadron star density contours are also presented and are compared with those produced by proton beams. This FLUKA-EGS4 coupling technique could find use in the design of secondary beams, in the determination high energy hadron source terms for shielding purposes, and in the estimation of induced radioactivity in targets, collimators and beam dumps

  4. Meteor showers an annotated catalog

    CERN Document Server

    Kronk, Gary W

    2014-01-01

    Meteor showers are among the most spectacular celestial events that may be observed by the naked eye, and have been the object of fascination throughout human history. In “Meteor Showers: An Annotated Catalog,” the interested observer can access detailed research on over 100 annual and periodic meteor streams in order to capitalize on these majestic spectacles. Each meteor shower entry includes details of their discovery, important observations and orbits, and gives a full picture of duration, location in the sky, and expected hourly rates. Armed with a fuller understanding, the amateur observer can better view and appreciate the shower of their choice. The original book, published in 1988, has been updated with over 25 years of research in this new and improved edition. Almost every meteor shower study is expanded, with some original minor showers being dropped while new ones are added. The book also includes breakthroughs in the study of meteor showers, such as accurate predictions of outbursts as well ...

  5. New meteor showers – yes or not?

    Science.gov (United States)

    Koukal, Jakub

    2018-01-01

    The development of meteor astronomy associated with the development of CCD technology is reflected in a huge increase in databases of meteor orbits. It has never been possible before in the history of meteor astronomy to examine properties of meteors or meteor showers. Existing methods for detecting new meteor showers seem to be inadequate in these circumstances. The spontaneous discovery of new meteor showers leads to ambiguous specifications of new meteor showers. There is a duplication of already discovered meteor showers and a division of existing meteor showers based on their own criteria. The analysis in this article considers some new meteor showers in the IAU MDC database.

  6. Sunshine and light showers

    International Nuclear Information System (INIS)

    2008-01-01

    Full text: Sunshine and light showers are forecast for the Oscar winning actor Cate Blanchett as she increasingly greens her lifestyle. She is installing solar panels to power her Sydney home and has cut her showers back to a maximum of four minutes to help save water in drought-stricken Australia. And that is only a beginning, for she is also greening her main place of work, is campaigning on solar power and climate change, and has committed to other changes in her life to save energy and water. Blanchett - who sprang to fame in the title role of the film Elisabeth ten years ago - learned conservation when growing up in Melbourne in the 1970s from her grandmother who had lived through the Great Depression and, as a result, insisted in recycling and on letting nothing go to waste. She grew up to win an Oscar for her role in Martin Scorsese's The Aviator, amid a host of other top awards, and was spurred into environmental activism by reading about her country's growing water crisis. She says: 'As I see it, there is no greater challenge we face as a species than dealing with climate change and its effects. I care about it because of my children. I want to safeguard their future. It is an inescapable problem, but also provides us with an opportunity to change for the better. To change the way we consume, the way we think, and the way we behave. By assuming responsibility, we protect and respect the generations behind us.' Together with her husband, playwright Andrew Upton, she has started by setting out to 'greenovate' their home: powering it with solar energy, using natural air flows rather than air conditioning to cool it, and recycling grey water. The couple also plan to extend the improvements to the Sydney Theatre Company, where they are joint artistic directors, with the aim of running off-grid for a whole season. 'I really love a refreshing shower,' she says, but has installed a timer to stop them after four minutes. Indeed she tries to make them even shorter

  7. Distinguishability of Neutrino Flavors Through Their Different Shower Characteristics

    Science.gov (United States)

    Chen, Chih-Ching; Chen, Pisin; Hu, Chia-Yu; Lai, K.-C.

    2013-12-01

    We propose a new avor identification method to distinguish mu and tau type ultra high energy cosmic neutrinos (UHECN). Energy loss of leptons in matter is an important information for the detection of neutrinos originated from high energy astrophysical sources. 50 years ago, Askaryan proposed to detect Cherenkov radiowave signals emitted from the negative charge excess of neutrino-induced particle shower. The theory of Cherenkov radiation under Fraunhofer approximation has been widely studied in the past two decades. However, at high energies or for high density materials, electromagnetic shower should be elongated due to the Landau-Pomeranchuck-Migdal (LPM) effect. As such the standard Fraunhofer approximation ceases to be valid when the distance between the shower and the detector becomes comparable with the shower length. Monte Carlo simulations have been performed recently to investigate this regime. Here we adopt the deduced relationship between the radio signal and the cascade development profile to investigate its implication to lepton signatures. Our method provides a straightforward technique to identify the neutrino avor through the detected Cherenkov signals.

  8. Various meteor scenes III: Recurrent showers and some minor showers

    Science.gov (United States)

    Koseki, Masahiro

    2015-02-01

    Meteor activities vary widely from year to year. We study here the June Bootids (JBO), τ-Herculids (TAH), and Andromedids (AND) which are basic examples for the recurrent nature of meteor showers. Half a century has passed since well-known photographic or radar meteor showers were detected. It is necessary to note that some `established' IAU showers are historical ones and we cannot always see them. We find the historical trace of AND by video and four distinct activities in the area of JBC (=JBO+TAH). Meteor showers look different by different observational techniques. Many minor showers in the IAU list have been detected only by observations stored for many days and many years; visual observations in a single night cannot perceive them naturally. We studied the φ-Piscids (PPS), χ-Taurids (CTA), γ-Ursae Minorids (GUM), η-Pegasids (ETP), and α-Sextantids (ASX) as examples and found they have not been recognized by visual observers at all. It is noteworthy that some of them have possible identifications in the IAU list and in preceding observations or reports. The difference in search methods makes the situations much more complicated. The five minor showers we studied here do not have confirmations by all observational techniques. Geobased search (radiant point, time of the observation, and possibly geocentric velocity) may overlook showers which are dispersed in radiant position. A search using the D-criterion is dependent on the presumption of a spherical distribution in the orbital space and may not represent the real distribution, or may overestimate the accuracy of the observations and lead to subdividing the showers into several parts. We must use these search methods properly.

  9. Extensive Air Showers High Energy Phenomena and Astrophysical Aspects - A Tutorial, Reference Manual and Data Book

    CERN Document Server

    Grieder, Peter K.F

    2010-01-01

    Extensive air showers are a very unique phenomenon. In the more than six decades since their discovery by Auger et al. we have learned a great deal about these extremely energetic events and gained deep insights into high-energy phenomena, particle physics and astrophysics. In this Tutorial, Reference Manual and Data Book Peter K. F. Grieder provides the reader with a comprehensive view of the phenomenology and facts of the various types of interactions and cascades, theoretical background, experimental methods, data evaluation and interpretation, and air shower simulation. He discusses astrophysical aspects of the primary radiation and addresses the questions that continue to puzzle researchers. The book is divided into two parts, each in its own separate volume: Part I in Volume I deals mainly with the basic theoretical framework of the processes that determine an air shower and ends with a summary of ways to extract information on the primary radiation from air shower observations. It also presents a compi...

  10. Monte Carlo simulations of the timing structure of Cherenkov wavefronts of sub-100 GeV gamma ray air showers

    International Nuclear Information System (INIS)

    Peaper, D. R.; Gottbrath, C. L.; Kertzman, M. P.; Sembroski, G. H.

    1997-01-01

    We present a Monte-Carlo study of the phenomenology of Cherenkov light wavefronts from low energy gamma ray induced air showers. Experimentally the measurements of the spatially distributed arrival times of the wavefronts of the Cherenkov light of gamma ray air showers have been used to extract the directions of the showers. This has mainly been done for >500 GeV showers using a conical fit to the timing structure of the wavefront. This directionality is then used to contribute to the rejection of background showers (mainly hadron induced showers) which arrive isotropically. Investigation of the arrival times of simulated Cherenkov photons from gamma ray induced air showers of energies 100 GeV and below reveals that there is greater variation in the morphology of the wavefronts than at the higher energies and that the fitting of simple conical functions to determine arrival directions may no longer be appropriate. We demonstrate that the detailed structure of the wavefront of these low energy gamma ray showers is primarily determined by the height distribution of the emitting cascade particles. Preliminary work suggests a correlation between the shape of the wavefront and the height of shower-maximum

  11. The Time Structure of Hadronic Showers in Calorimeters with Scintillator and with Gas Readout

    CERN Document Server

    Szalay, M

    2015-01-01

    The time structure of hadronic showers is characterized by apromptcomponent from relativistic particles and by late components predominantly connected to neutrons in the cascade.The sensitivity to this late component thus depends on the choice of the active medium for hadronic calorimeters.

  12. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    NARCIS (Netherlands)

    Pierre Auger Collaboration, [No Value; Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Samarai, I. Al; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; D\\'\\iaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garc\\'\\ia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Albarracin, F.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Lopez Agëra, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Mart\\'\\inez Bravo, O.; Martraire, D.; Mas\\'\\ias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Ortiz, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pȩkala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodr\\'\\iguez-Fr\\'\\ias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Rühle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiał kowski, A.; Šm\\'\\ida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.

    2014-01-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade

  13. Simulation Study on Identifiability of UHE Gamma-ray Air Showers

    International Nuclear Information System (INIS)

    Wada, Y.; Inoue, N.; Miyazawa, K.; Vankov, H.P.

    2008-01-01

    The chemical composition of Ultra-High-Energy (UHE) comic rays is one of unsolved mysteries, and its study will give us fruitful information on the origin and acceleration mechanism of UHE cosmic rays. Especially, a detection of UHE gamma-rays by hybrid experiments, such as AUGER and TA, will be a key to solve these questions. The characteristics of UHE gamma-ray showers have been studied by comparing the lateral and longitudinal structures of shower particles calculated with AIRES and our own simulation code, so far. There are apparent differences in a slope of lateral distribution (η) and a depth of shower maximum (Xmax) between gamma-ray and proton induced showers because UHE gamma-ray showers are affected by the LPM effect and the geomagnetic cascading process in an energy region of >10 19.5 eV. Different features between gamma-ray and proton showers are pointed out from the simulation study and an identifiability of gamma-ray showers from proton ones is also discussed by the method of Neural-Network-Analysis

  14. Increasing Geminid meteor shower activity

    Science.gov (United States)

    Ryabova, G. O.; Rendtel, J.

    2018-03-01

    Mathematical modelling has shown that activity of the Geminid meteor shower should rise with time, and that was confirmed by analysis of visual observations 1985-2016. We do not expect any outburst activity of the Geminid shower in 2017, even though the asteroid (3200) Phaethon has a close approach to Earth in December of 2017. A small probability to observe dust ejected at perihelia 2009-2016 still exists.

  15. Meteor Shower Forecasting for Spacecraft Operations

    Science.gov (United States)

    Moorhead, Althea V.; Cooke, William J.; Campbell-Brown, Margaret D.

    2017-01-01

    Although sporadic meteoroids are a much greater hazard to spacecraft than shower meteoroids in general, meteor showers can significantly increase the risk of damage over short time periods. Because showers are brief, it is sometimes possible to mitigate the risk operationally, which requires accurate predictions of shower activity. NASA's Meteoroid Environment Office generates an annual meteor shower forecast that describes the variations in the near-Earth meteoroid flux produced by meteor showers, which presents the shower flux both in absolute terms and relative to the sporadic ux. The shower forecast incorporates model predictions of annual variations in shower activity and quotes fluxes to several limiting particle kinetic energies. In this work, we describe our forecasting methods, compare them to actual observations, and highlight recent improvements to the temporal pro les based on flux measurements from the Canadian Meteor Orbit Radar (CMOR).

  16. The Mbale meteorite shower

    Science.gov (United States)

    Jenniskens, Peter; Betlem, Hans; Betlem, Jan; Barifaijo, Erasmus; Schluter, Thomas; Hampton, Craig; Laubenstien, Matthias; Kunz, Joachim; Heusser, Gerd

    1994-01-01

    On 1992 August 14 at 12:40 UTC, an ordinary chondrite of type L5/6 entered the atmosphere over Mbale, Uganda, broke up, and caused a strewn field of size 3 x 7 km. Shortly after the fall, an expedition gathered eye witness accounts and located the position of 48 impacts of masses between 0.19 and 27.4 kg. Short-lived radionuclide data were measured for two specimens, one of which was only 12 days after the fall. Subsequent recoveries of fragements has resulted in a total of 863 mass estimates by 1993 October. The surfaces of all fragments contain fusion crust. The meteorite shower caused some minor inconveniences. Most remarkably, a young boy was hit on the head by a small specimen. The data interpreted as to indicate that the meteorite had an initial mass between 400-1000 kg (most likely approximately 1000 kg) and approached Mbale from AZ = 185 +/- 15, H = 55 +/- 15, and V(sub infinity) = 13.5 +/- 1.5/s. Orbital elements are given. Fragmentation of the initial mass started probably above 25 km altitude, but the final catastrophic breakup occurred at an altitude of 10-14 km. An estimated 190 +/- 40 kg reached the Earth's surface minutes after the final breakup of which 150 kg of material has been recovered.

  17. Track reconstruction in BES barrel shower counter

    International Nuclear Information System (INIS)

    Zhao Haiwen; Wang Taijie; Mao Zepu; Li Jin; Li Weiguo; Yan Wuguang; Chen Guangpei; Liu Jing; Li Peiqin; Rong Gang; Yuan Ye; Liu Hongtao

    1999-01-01

    The track reconstruction of BES barrel shower counter was presented and the shower finding, pattern recognition technique were described. The reconstruction results from experimental data were presented and discussed

  18. Time distribution of shower particle arrivals at various distances from the axis of extensive air shower

    International Nuclear Information System (INIS)

    Vedeneev, O.V.; Kulikov, G.V.; Matsenov, S.I.

    1986-01-01

    Experimental data on time structure of an extensive air shower (EAS) disk obtained at the Mosscow University EAS are presented. Particle distributions in the depth of a shower disk and radii of shower front curvature at distance interval from the axis of the shower 200-600 m, are obtained

  19. 1997 Leonid Shower From Space

    Science.gov (United States)

    Jenniskens, Peter; Nugent, David; Murthy, Jayant; Tedesco, Ed; DeVincenzi, Donal L. (Technical Monitor)

    2000-01-01

    In November 1997, the Midcourse Space Experiment satellite (MSX) was deployed to observe the Leonid shower from space. The shower lived up to expectations, with abundant bright fireballs. Twenty-nine meteors were detected by a wide-angle, visible wavelength, camera near the limb of the Earth in a 48-minute interval, and three meteors by the narrow field camera. This amounts to a meteoroid influx of 5.5 +/- 0.6 10(exp -5)/sq km hr for masses greater than 0.3 gram. The limiting magnitude for limb observations of Leonid meteors was measured at M(sub v) = -1.5 magn The Leonid shower magnitude population index was 1.6 +/- 0.2 down to M(sub v) = -7 magn., with no sign of an upper mass cut-off.

  20. QCD Matrix Elements + Parton Showers

    CERN Document Server

    Catani, S; Kühn, R; Webber, Bryan R

    2001-01-01

    We propose a method for combining QCD matrix elements and parton showers in Monte Carlo simulations of hadronic final states in $e^+e^-$ annihilation. The matrix element and parton shower domains are separated at some value $y_{ini}$ of the jet resolution, defined according to the $k_T$-clustering algorithm. The matrix elements are modified by Sudakov form factors and the parton showers are subjected to a veto procedure to cancel dependence on $y_{ini}$ to next-to-leading logarithmic accuracy. The method provides a leading-order description of hard multi-jet configurations together with jet fragmentation, while avoiding the most serious problems of double counting. We present first results of an approximate implementation using the event generator APACIC++.

  1. Calculations with off-shell matrix elements, TMD parton densities and TMD parton showers

    Science.gov (United States)

    Bury, Marcin; van Hameren, Andreas; Jung, Hannes; Kutak, Krzysztof; Sapeta, Sebastian; Serino, Mirko

    2018-02-01

    A new calculation using off-shell matrix elements with TMD parton densities supplemented with a newly developed initial state TMD parton shower is described. The calculation is based on the KaTie package for an automated calculation of the partonic process in high-energy factorization, making use of TMD parton densities implemented in TMDlib. The partonic events are stored in an LHE file, similar to the conventional LHE files, but now containing the transverse momenta of the initial partons. The LHE files are read in by the Cascade package for the full TMD parton shower, final state shower and hadronization from Pythia where events in HEPMC format are produced. We have determined a full set of TMD parton densities and developed an initial state TMD parton shower, including all flavors following the TMD distribution. As an example of application we have calculated the azimuthal de-correlation of high p_t dijets as measured at the LHC and found very good agreement with the measurement when including initial state TMD parton showers together with conventional final state parton showers and hadronization.

  2. Calculations with off-shell matrix elements, TMD parton densities and TMD parton showers.

    Science.gov (United States)

    Bury, Marcin; van Hameren, Andreas; Jung, Hannes; Kutak, Krzysztof; Sapeta, Sebastian; Serino, Mirko

    2018-01-01

    A new calculation using off-shell matrix elements with TMD parton densities supplemented with a newly developed initial state TMD parton shower is described. The calculation is based on the KaTie package for an automated calculation of the partonic process in high-energy factorization, making use of TMD parton densities implemented in TMDlib. The partonic events are stored in an LHE file, similar to the conventional LHE files, but now containing the transverse momenta of the initial partons. The LHE files are read in by the Cascade package for the full TMD parton shower, final state shower and hadronization from Pythia where events in HEPMC format are produced. We have determined a full set of TMD parton densities and developed an initial state TMD parton shower, including all flavors following the TMD distribution. As an example of application we have calculated the azimuthal de-correlation of high [Formula: see text] dijets as measured at the LHC and found very good agreement with the measurement when including initial state TMD parton showers together with conventional final state parton showers and hadronization.

  3. 46 CFR 154.1410 - Decontamination shower.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Decontamination shower. 154.1410 Section 154.1410... Equipment § 154.1410 Decontamination shower. When Table 4 references this section, a vessel carrying the listed cargo must have a decontamination shower and an eye wash that: (a) Are on the weatherdeck; and (b...

  4. Subleading-Nc improved parton showers

    International Nuclear Information System (INIS)

    Plaetzer, Simon; Sjoedahl, Malin

    2012-06-01

    We present an algorithm for improving subsequent parton shower emissions by full SU(3) colour correlations in the framework of a dipole-type shower. As a proof of concept, we present results from the first implementation of such an algorithm for a final state shower.

  5. Wavelet cascades

    Science.gov (United States)

    Giesemann, Jens; Greiner, Martin; Lipa, Peter

    1997-02-01

    The generators of binary multiplicative cascade models with a non-overlapping branching structure are given by the Haar wavelets. We construct specific generalizations of these models for which any given wavelet represents the generators of the local cascade branchings. Such “wavelet cascades”, for which we calculate spatial correlation functions, have spatially overlapping branches and are therefore useful for modeling recombination effects in hierarchical branching processes.

  6. Air shower measurements with LOFAR

    NARCIS (Netherlands)

    Horneffer, A.; Bähren, L.; Buitink, S.; Falcke, H.; Hörandel, J.R.; Kuijpers, J.; Lafebre, S.; Nigl, A.; Scholten, O.; Singh, K.

    2009-01-01

    Air showers from cosmic rays emit short, intense radio pulses. The Low Frequency Array (LOFAR) is a new radio telescope, that is being built in the Netherlands and Europe. Designed primarily as a radio interferometer, the core of LOFAR will have a high density of radio antennas, which will be

  7. An analytic initial-state parton shower

    International Nuclear Information System (INIS)

    Kilian, W.

    2011-12-01

    We present a new algorithm for an analytic parton shower. While the algorithm for the final-state shower has been known in the literature, the construction of an initial-state shower along these lines is new. The aim is to have a parton shower algorithm for which the full analytic form of the probability distribution for all branchings is known. For these parton shower algorithms it is therefore possible to calculate the probability for a given event to be generated, providing the potential to reweight the event after the simulation. We develop the algorithm for this shower including scale choices and angular ordering. Merging to matrix elements is used to describe high-energy tails of distributions correctly. Finally, we compare our results with those of other parton showers and with experimental data from LEP, Tevatron and LHC. (orig.)

  8. Reconstruction of inclined air showers detected with the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    collaboration, The Pierre Augur

    2014-08-01

    We describe the method devised to reconstruct inclined cosmic-ray air showers with zenith angles greater than 60° detected with the surface array of the Pierre Auger Observatory. The measured signals at the ground level are fitted to muon density distributions predicted with atmospheric cascade models to obtain the relative shower size as an overall normalization parameter. The method is evaluated using simulated showers to test its performance. The energy of the cosmic rays is calibrated using a sub-sample of events reconstructed with both the fluorescence and surface array techniques. The reconstruction method described here provides the basis of complementary analyses including an independent measurement of the energy spectrum of ultra-high energy cosmic rays using very inclined events collected by the Pierre Auger Observatory.

  9. Measurement of the ultra high energy cosmic ray flux from data of very inclined showers at the Pierre Auger Observatory

    Energy Technology Data Exchange (ETDEWEB)

    Dembinski, Hans Peter

    2009-12-03

    This work describes the derivation of the energy dependent flux of ultra-high energy cosmic rays from data of very inclined air showers observed with the Pierre Auger Observatory. It focuses on the event class of very inclined air showers with zenith angles larger than 60 . The lateral ground profile of these showers is muon dominated and not radially symmetric around the shower axis due to geomagnetic deflections and other effects. The dependency of this profile on the direction, energy and mass of the cosmic ray is discussed with a mixture of detailed Monte-Carlo simulations and a simplified analytical model of the air shower cascade. It is found in agreement with other studies that the normalized shape of the muon density profile is approximately universal over the range of cosmic ray energies and masses measured at the Pierre Auger Observatory, that the amplitude of the profile is almost proportional to the cosmic ray energy, and that its shower-to-shower fluctuations are sensitive to the mass composition of the cosmic rays. (orig.)

  10. Measurement of the ultra high energy cosmic ray flux from data of very inclined showers at the Pierre Auger Observatory

    International Nuclear Information System (INIS)

    Dembinski, Hans Peter

    2009-01-01

    This work describes the derivation of the energy dependent flux of ultra-high energy cosmic rays from data of very inclined air showers observed with the Pierre Auger Observatory. It focuses on the event class of very inclined air showers with zenith angles larger than 60 . The lateral ground profile of these showers is muon dominated and not radially symmetric around the shower axis due to geomagnetic deflections and other effects. The dependency of this profile on the direction, energy and mass of the cosmic ray is discussed with a mixture of detailed Monte-Carlo simulations and a simplified analytical model of the air shower cascade. It is found in agreement with other studies that the normalized shape of the muon density profile is approximately universal over the range of cosmic ray energies and masses measured at the Pierre Auger Observatory, that the amplitude of the profile is almost proportional to the cosmic ray energy, and that its shower-to-shower fluctuations are sensitive to the mass composition of the cosmic rays. (orig.)

  11. Learning Cascading

    CERN Document Server

    Covert, Michael

    2015-01-01

    This book is intended for software developers, system architects and analysts, big data project managers, and data scientists who wish to deploy big data solutions using the Cascading framework. You must have a basic understanding of the big data paradigm and should be familiar with Java development techniques.

  12. Ordering variable for parton showers

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2014-01-01

    The parton splittings in a parton shower are ordered according to an ordering variable, for example the transverse momentum of the daughter partons relative to the direction of the mother, the virtuality of the splitting, or the angle between the daughter partons. We analyze the choice of the ordering variable and conclude that one particular choice has the advantage of factoring softer splittings from harder splittings graph by graph in a physical gauge.

  13. Study of electromagnetic and hadronic showers with liquid-argon calorimeters

    International Nuclear Information System (INIS)

    Rauschnabel, K.

    1978-05-01

    High energy electrons, pions and protons have been detected by two liquid-argon calorimeters. Measurements of the linearity and energy resolution of the detectors have been performed. As one of the detectors consisted of 80 sections, the spatial development of hadronic cascades could be studied. The results are in reasonable agreement with Monte-Carlo simulations. The spatial and angular resolutions of the detector have been evaluated. Using their different longitudinal shower development, electrons and hadrons could be separated. (orig.) [de

  14. Shower maximum detector for SDC calorimetry

    International Nuclear Information System (INIS)

    Ernwein, J.

    1994-01-01

    A prototype for the SDC end-cap (EM) calorimeter complete with a pre-shower and a shower maximum detector was tested in beams of electrons and Π's at CERN by an SDC subsystem group. The prototype was manufactured from scintillator tiles and strips read out with 1 mm diameter wave-length shifting fibers. The design and construction of the shower maximum detector is described, and results of laboratory tests on light yield and performance of the scintillator-fiber system are given. Preliminary results on energy and position measurements with the shower max detector in the test beam are shown. (authors). 4 refs., 5 figs

  15. Fast Shower Simulation in the ATLAS Calorimeter

    International Nuclear Information System (INIS)

    Butler, B.; Young, C.C.

    2011-01-01

    The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterization is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to ∼ 1 GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper.

  16. The return of the Andromedids meteor shower

    OpenAIRE

    Wiegert, Paul A.; Brown, Peter G.; Weryk, Robert J.; Wong, Daniel K.

    2012-01-01

    The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as `stars fell like rain' in Chinese records of the time. The shower originates from comet 3D/Biela whose disintegration in the mid-1800's is linked to the outbursts, but the shower has been weak or absent since the late 19th Century. This shower returned in December 2011 with a zenithal hourly rate of approximately 50, the strongest return in over a hund...

  17. Fast shower simulation in the ATLAS calorimeter

    International Nuclear Information System (INIS)

    Barberio, E; Boudreau, J; Mueller, J; Tsulaia, V; Butler, B; Young, C C; Cheung, S L; Savard, P; Dell'Acqua, A; Simone, A D; Gallas, M V; Ehrenfeld, W; Glazov, A; Placakyte, R; Marshall, Z; Rimoldi, A; Waugh, A

    2008-01-01

    The time to simulate pp collisions in the ATLAS detector is largely dominated by the showering of electromagnetic particles in the heavy parts of the detector, especially the electromagnetic barrel and endcap calorimeters. Two procedures have been developed to accelerate the processing time of electromagnetic particles in these regions: (1) a fast shower parameterisation and (2) a frozen shower library. Both work by generating the response of the calorimeter to electrons and positrons with Geant 4, and then reintroduce the response into the simulation at runtime. In the fast shower parameterisation technique, a parameterisation is tuned to single electrons and used later by simulation. In the frozen shower technique, actual showers from low-energy particles are used in the simulation. Full Geant 4 simulation is used to develop showers down to ∼ 1GeV, at which point the shower is terminated by substituting a frozen shower. Judicious use of both techniques over the entire electromagnetic portion of the ATLAS calorimeter produces an important improvement of CPU time. We discuss the algorithms and their performance in this paper

  18. Muon production in extended air shower simulations.

    Science.gov (United States)

    Pierog, T; Werner, K

    2008-10-24

    Whereas air shower simulations are very valuable tools for interpreting cosmic ray data, there is a long-standing problem: it is difficult to accommodate at the same time the longitudinal development of air showers and the number of muons measured on the ground. Using a new hadronic interaction model (EPOS) in air shower simulations produces much more muons, in agreement with results from the HiRes-MIA experiment. We find that this is mainly due to a better description of (anti) baryon production in hadronic interactions. This is an aspect of air shower physics which has been neglected so far.

  19. Improved parton showers in ep interactions

    International Nuclear Information System (INIS)

    Bengtsson, M.

    1988-05-01

    A scheme for including the first order matrix element in ep parton showers is presented. This is an important improvement since it applies to hard emission where the leading-log approximation is less reliable. The contributions from the initial and final state showers are treated on an equal footing, solving the potential problem of double counting of emission. Kinematical constraints, relating the dynamics of the two separate showers, are also solved in this context. The choice of splitting variable in initial state showers is furthermore discussed. (orig.)

  20. Shower library technique for fast simulation of showers in calorimeters of the H1 experiment

    International Nuclear Information System (INIS)

    Raičević, N.; Glazov, A.; Zhokin, A.

    2013-01-01

    Fast simulation of showers in calorimeters is very important for particle physics analysis since shower simulation typically takes significant amount of the simulation time. At the same time, a simulation must reproduce experimental data in the best possible way. In this paper, a fast simulation of showers in two calorimeters of the H1 experiment is presented. High speed and good quality of shower simulation is achieved by using a shower library technique in which the detector response is simulated using a collection of stored showers for different particle types and topologies. The library is created using the GEANT programme. The fast simulation based on shower library is compared to the data collected by the H1 experiment

  1. Frozen-shower simulation of electromagnetic showers in the ATLAS forward calorimeter

    CERN Document Server

    Gasnikova, Ksenia; The ATLAS collaboration

    2016-01-01

    Accurate simulation of calorimeter response for high energy electromagnetic particles is essential for the LHC experiments. Detailed simulation of the electromagnetic showers using Geant4 is however very CPU intensive and various fast simulation methods were proposed instead. The frozen shower simulation substitutes the full propagation of the showers for energies below 1~GeV by showers taken from a pre-simulated library. The method is used for production of the main ATLAS Monte Carlo samples, greatly improving the production time. The frozen showers describe shower shapes, sampling fraction, sampling and noise-related fluctuations very well, while description of the constant term, related to calorimeter non-uniformity, requires a careful choice of the shower library binning. A new method is proposed to tune the binning variables, using multivariate techniques. The method is tested and optimized for the description of the ATLAS forward calorimeter.

  2. Pion showers in highly granular calorimeters

    Indian Academy of Sciences (India)

    New results on properties of hadron showers created by pion beam at 8–80 GeV in high granular electromagnetic and hadron calorimeters are presented. Data were used for the first time to investigate the separation of the neutral and charged hadron showers. The result is important to verify the prediction of the PFA ...

  3. Microwave detection of air showers with MIDAS

    Czech Academy of Sciences Publication Activity Database

    Facal San Luis, P.; Alekotte, I.; Alvarez, J.; Berlin, A.; Bertou, X.; Bogdan, M.; Boháčová, Martina; Bonifazi, C.; Carvalho, W.R.; de Mello Neto, J.R.T.; Genat, J.F.; Mills, E.; Monasor, M.; Privitera, P.; Reyes, I.C.; d´Orfeuil, B.R.; Santos, E.M.; Wayne, S.; Williams, C.; Zas, E.

    2012-01-01

    Roč. 662, Sup. 1 (2012), "S118"-"S123" ISSN 0168-9002 R&D Projects: GA MŠk(CZ) LA08016 Institutional research plan: CEZ:AV0Z10100502 Keywords : MIDAS (Microwave Detector of Air Showers) * extensive air showers Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.142, year: 2012

  4. Investigation of beauty production and parton shower effects at LHC

    CERN Document Server

    Jung, H.; Lipatov, A.V.; Zotov, N.P.

    2011-01-01

    We present hadron-level predictions from the Monte Carlo generator Cascade and parton level calculations of open b quark, b-flavored hadron and inclusive b-jet production in the framework of the kt-factorization QCD approach for the LHC energies. The unintegrated gluon densities in a proton are determined using the CCFM evolution equation and the Kimber-Martin-Ryskin (KMR) prescription. Our predictions are compared with the first data taken by the CMS and LHCb collaborations at 7 TeV. We study the theoretical uncertainties of our calculations and investigate the effects coming from parton showers in initial and final states. The special role of initial gluon transverse momenta in description of the data is pointed out.

  5. A Parton Shower for High Energy Jets

    DEFF Research Database (Denmark)

    Andersen, Jeppe Rosenkrantz; Lonnblad, Leif; M. Smillie, Jennifer

    2011-01-01

    We present a method to match the multi-parton states generated by the High Energy Jets Monte Carlo with parton showers generated by the Ariadne program using the colour dipole model. The High Energy Jets program already includes a full resummation of soft divergences. Hence, in the matching...... it is important that the corresponding divergences in the parton shower are subtracted, keeping only the collinear parts. We present a novel, shower-independent method for achieving this, enabling us to generate fully exclusive and hadronized events with multiple hard jets, in hadronic collisions. We discuss...

  6. Radar reflection off extensive air showers

    Directory of Open Access Journals (Sweden)

    Werner F.

    2013-06-01

    Full Text Available We investigate the possibility of detecting extensive air showers by the radar technique. Considering a bistatic radar system and different shower geometries, we simulate reflection of radio waves off the static plasma produced by the shower in the air. Using the Thomson cross-section for radio wave reflection, we obtain the time evolution of the signal received by the antennas. The frequency upshift of the radar echo and the power received are studied to verify the feasibility of the radar detection technique.

  7. THE RETURN OF THE ANDROMEDIDS METEOR SHOWER

    International Nuclear Information System (INIS)

    Wiegert, Paul A.; Brown, Peter G.; Weryk, Robert J.; Wong, Daniel K.

    2013-01-01

    The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as ''stars fell like rain'' in Chinese records of the time. The shower originates from comet 3D/Biela whose disintegration in the mid-1800's is linked to the outbursts, but the shower has been weak or absent since the late 19th century. This shower returned in 2011 December with a zenithal hourly rate of approximately 50, the strongest return in over a hundred years. Some 122 probable Andromedid orbits were detected by the Canadian Meteor Orbit Radar while one possible brighter Andromedid member was detected by the Southern Ontario Meteor Network and several single station possible Andromedids by the Canadian Automated Meteor Observatory. The shower outburst occurred during 2011 December 3-5. The radiant at R.A. +18° and decl. +56° is typical of the ''classical'' Andromedids of the early 1800s, whose radiant was actually in Cassiopeia. Numerical simulations of the shower were necessary to identify it with the Andromedids, as the observed radiant differs markedly from the current radiant associated with that shower. The shower's orbital elements indicate that the material involved was released before 3D/Biela's breakup prior to 1846. The observed shower in 2011 had a slow geocentric speed (V G = 16 km s –1 ) and was comprised of small particles: the mean measured mass from the radar is ∼5 × 10 –7 kg, corresponding to radii of 0.5 mm at a bulk density of 1000 kg m –3 . Numerical simulations of the parent comet indicate that the meteoroids of the 2011 return of the Andromedids shower were primarily ejected during 3D/Biela's 1649 perihelion passage. The orbital characteristics, radiant, and timing as well as the absence of large particles in the streamlet are all broadly consistent with simulations. However, simulations of the 1649 perihelion passage necessitate going back five Lyapunov times (which is only 25 yr for the

  8. Measurement of the muon content in air showers at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Veberič Darko

    2016-01-01

    Full Text Available The muon content of extensive air showers produced by ultra-high energy cosmic rays is an observable sensitive to the composition of primary particles and to the properties of hadronic interactions governing the evolution of air-shower cascades. We present different methods for estimation of the number of muons at the ground and the muon production depth. These methods use measurements of the longitudinal, lateral, and temporal distribution of particles in air showers recorded by the detectors of the Pierre Auger Observatory. The results, obtained at about 140 TeV center-of-mass energy for proton primaries, are compared to the predictions of LHC-tuned hadronic-interaction models used in simulations with different primary masses. The models exhibit a deficitin the predicted muon content. The combination of these results with other independent mass composition analyses, such as those involving the depth of shower maximum observablemax, provide additional constraints on hadronic-interaction models for energies beyond the reach of the LHC.

  9. Comet showers and Nemesis, the death star

    International Nuclear Information System (INIS)

    Hills, J.G.

    1984-01-01

    The recently proposed hypothesis that the periodic extinctions of terrestrial species are the result of comet showers catalyzed by a hypothetical distant solar companion, Nemesis, a tale of global death by comet bombardment of the earth, is discussed

  10. Bath and Shower Diverter Notice of Intent

    Science.gov (United States)

    An often-overlooked source of wasted water, many bath and shower diverters continuously leak a small amount of water from the tub spout while they are engaged, and water is being diverted from the bathtub to the showerhead.

  11. A Meteor Shower Origin for Martian Methane

    Science.gov (United States)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.; Steele, A.; Treiman, A.

    2015-07-01

    We present and discuss the hypothesis that martian methane arises from a meteor shower source. Infall material produces methane by UV photolysis, generating localized plumes that occur after Mars/comet orbit interactions. This hypothesis is testable.

  12. Structural peculiarities of the Quadrantid meteor shower

    Science.gov (United States)

    Isamutdinov, Sh. O.; Chebotarev, R. P.

    1987-01-01

    Systematic radio observations to investigate the Quadrantid meteor shower structure are regularly carried out. They have now been conducted annually in the period of its maximum activity, January 1 to 6, since 1966. The latest results of these investigations are presented, on the basis of 1981 to 1984 data obtained using new equipment with a limiting sensitivity of +7.7 sup m which make it possible to draw some conclusions on the Quadrantids shower structure both for transverse and lengthwise directions.

  13. Fully NLO Parton Shower in QCD

    International Nuclear Information System (INIS)

    Skrzypek, M.; Jadach, S.; Slawinska, M.; Gituliar, O.; Kusina, A.; Placzek, W.

    2011-01-01

    The project of constructing a complete NLO-level Parton Shower Monte Carlo for the QCD processes developed in IFJ PAN in Krakow is reviewed. Four issues are discussed: (1) the extension of the standard inclusive collinear factorization into a new, fully exclusive scheme; (2) reconstruction of the LO Parton Shower in the new scheme; (3) inclusion of the exclusive NLO corrections into the hard process and (4) inclusion of the exclusive NLO corrections into the evolution (ladder) part. (authors)

  14. Scaling analysis of meteorite shower mass distributions

    DEFF Research Database (Denmark)

    Oddershede, Lene; Meibom, A.; Bohr, Jakob

    1998-01-01

    Meteorite showers are the remains of extraterrestrial objects which are captivated by the gravitational field of the Earth. We have analyzed the mass distribution of fragments from 16 meteorite showers for scaling. The distributions exhibit distinct scaling behavior over several orders of magnetude...... the observed scaling exponents to exponents observed in laboratory experiments and discuss the possibility that one can derive insight into the original shapes of the meteoroids....

  15. The Time Structure of Hadronic Showers in Calorimeters with Scintillator and with Gas Readout

    CERN Document Server

    Szalay, Marco

    2015-01-01

    Hadronic showers are characterized by a rich particle structure in the spatial as well as in the time domain. The prompt component comes from relativistic fragments that deposit energy at the ns scale, while late components are associated predominantly with neutrons in the cascade. To measure the impact of these late components, two experiments, based on gaseous and plastic active layers with steel and tungsten absorbers, were set up. The different choice for the material of the active layers produces distinct responses to neutrons, and consequently to late energy depositions. After discussing the technical aspects of these systems, we present a comparison of the signals, read out with fast digitizers with deep buffers, and provide detailed information of the time structure of hadronic showers over a long sampling window.

  16. The time development of hadronic showers and the T3B experiment

    International Nuclear Information System (INIS)

    Soldner, Christian

    2013-01-01

    The compact linear collider (CLIC) is a future linear e + e - collider operated at a center of mass energy of up to 3 TeV and with a collision rate of particle bunches of up to 2 GHz. This poses challenging requirements on the detector system. The accumulation of background events, such as γγ→hadrons resulting from Beamstrahlung, must be minimized through a precise time stamping capability in all subdetector systems. In the event reconstruction, the energy depositions within the calorimeters will be used to assign events precisely to a small set of consecutive bunch crossings. The finite time evolution of hadronic showers, on the other hand, requires an extended integration time to achieve a satisfactory energy resolution in the calorimeter. The energy resolution is also deteriorated by the leakage of shower particles. Tungsten is foreseen as dense absorber material, but the time evolution of hadron showers within such a calorimeter is not sufficiently explored yet. In the context of this thesis, the T3B experiment (short for Tungsten Timing Test Beam) was designed and constructed. It is optimized to measure the time development and the contribution of delayed energy depositions within hadronic cascades. The T3B experiment consists of 15 scintillator cells assembled in a strip. The scintillation light generated within the cells is detected by novel silicon photomultiplier whose signal is read out with fast oscilloscopes providing a sampling rate of 1.25 GHz. This strip was positioned behind two different calorimeter prototypes of the CALICE collaboration which use a tungsten and steel (for comparison) absorber structure. T3B was part of the CALICE test beam campaign 2010/2011 carried out at the PS and SPS at CERN and acquired data on hadronic showers in an energy range of 2-300 GeV. A test beam optimized data acquisition software was developed from scratch. With the development and application of a novel waveform decomposition algorithm, the time of arrival of

  17. The time development of hadronic showers and the T3B experiment

    Energy Technology Data Exchange (ETDEWEB)

    Soldner, Christian

    2013-06-06

    The compact linear collider (CLIC) is a future linear e{sup +}e{sup -} collider operated at a center of mass energy of up to 3 TeV and with a collision rate of particle bunches of up to 2 GHz. This poses challenging requirements on the detector system. The accumulation of background events, such as {gamma}{gamma}{yields}hadrons resulting from Beamstrahlung, must be minimized through a precise time stamping capability in all subdetector systems. In the event reconstruction, the energy depositions within the calorimeters will be used to assign events precisely to a small set of consecutive bunch crossings. The finite time evolution of hadronic showers, on the other hand, requires an extended integration time to achieve a satisfactory energy resolution in the calorimeter. The energy resolution is also deteriorated by the leakage of shower particles. Tungsten is foreseen as dense absorber material, but the time evolution of hadron showers within such a calorimeter is not sufficiently explored yet. In the context of this thesis, the T3B experiment (short for Tungsten Timing Test Beam) was designed and constructed. It is optimized to measure the time development and the contribution of delayed energy depositions within hadronic cascades. The T3B experiment consists of 15 scintillator cells assembled in a strip. The scintillation light generated within the cells is detected by novel silicon photomultiplier whose signal is read out with fast oscilloscopes providing a sampling rate of 1.25 GHz. This strip was positioned behind two different calorimeter prototypes of the CALICE collaboration which use a tungsten and steel (for comparison) absorber structure. T3B was part of the CALICE test beam campaign 2010/2011 carried out at the PS and SPS at CERN and acquired data on hadronic showers in an energy range of 2-300 GeV. A test beam optimized data acquisition software was developed from scratch. With the development and application of a novel waveform decomposition algorithm

  18. Macroscopic treatment of radio emission from cosmic ray air showers based on shower simulations

    NARCIS (Netherlands)

    Werner, Klaus; Scholten, Olaf

    We present a macroscopic calculation of coherent electro-magnetic radiation from air showers initiated by ultra-high energy cosmic rays, based on currents obtained from Monte Carlo simulations of air showers in a realistic geo-magnetic field. We can clearly relate the time signal to the time

  19. Analytic calculation of radio emission from parametrized extensive air showers : A tool to extract shower parameters

    NARCIS (Netherlands)

    Scholten, O.; Trinh, T. N. G.; de Vries, K. D.; Hare, B. M.

    2018-01-01

    The radio intensity and polarization footprint of a cosmic-ray induced extensive air shower is determined by the time-dependent structure of the current distribution residing in the plasma cloud at the shower front. In turn, the time dependence of the integrated charge-current distribution in the

  20. Analytic calculation of radio emission from parametrized extensive air showers: A tool to extract shower parameters

    Science.gov (United States)

    Scholten, O.; Trinh, T. N. G.; de Vries, K. D.; Hare, B. M.

    2018-01-01

    The radio intensity and polarization footprint of a cosmic-ray induced extensive air shower is determined by the time-dependent structure of the current distribution residing in the plasma cloud at the shower front. In turn, the time dependence of the integrated charge-current distribution in the plasma cloud, the longitudinal shower structure, is determined by interesting physics which one would like to extract, such as the location and multiplicity of the primary cosmic-ray collision or the values of electric fields in the atmosphere during thunderstorms. To extract the structure of a shower from its footprint requires solving a complicated inverse problem. For this purpose we have developed a code that semianalytically calculates the radio footprint of an extensive air shower given an arbitrary longitudinal structure. This code can be used in an optimization procedure to extract the optimal longitudinal shower structure given a radio footprint. On the basis of air-shower universality we propose a simple parametrization of the structure of the plasma cloud. This parametrization is based on the results of Monte Carlo shower simulations. Deriving the parametrization also teaches which aspects of the plasma cloud are important for understanding the features seen in the radio-emission footprint. The calculated radio footprints are compared with microscopic CoREAS simulations.

  1. Fast simulation of electromagnetic showers in the ATLAS calorimeter Frozen showers

    CERN Document Server

    Barberio, E; Butler, B; Cheung, S L; Dell'Acqua, A; Di Simone, A; Ehrenfeld, E; Gallas, M V; Glazov, A; Marshall, Z; Mueller, J; Plačakyte, R; Rimoldi, A; Savard, P; Tsulaia, V; Waugh, A; Young, C C

    2009-01-01

    One of the most time consuming process simulating pp interactions in the ATLAS detector at LHC is the simulation of electromagnetic showers in the calorimeter. In order to speed up the event simulation several parametrisation methods are available in ATLAS. In this paper we present a short description of a frozen shower technique, together with some recent benchmarks and comparison with full simulation.

  2. The arrival time distribution of muons in extensive air showers

    International Nuclear Information System (INIS)

    Villiers, E.J. de; Walt, D.J. van der; Urk, G. van; Grieder, P.K.F.

    1986-01-01

    The longitudinal structure of the muon disc has been studied up to distances of 60 m from the shower axis by measuring the relative arrival times between single muons in extensive air showers with particle numbers of 1 x 10 5 to 2 x 10 7 . A rather constant thickness of the shower disc was found up to 60 m from the shower axis. The longitudinal distribution up to 30 m from the shower axis is not in agreement with the results from a shower model with a fairly high multiplicity rule for secondary particle formation in hadron interactions. (author)

  3. Lateral Distribution Functions of Extensive Air Showers

    Science.gov (United States)

    Geranios, A.; Fokitis, E.; Maltezos, S.; Koutsokosta, D.; Antoniadou, I.; Malandraki, O.; Mastichiadis, A.; Antonopoulou, E.; Gika, V.; Dimitrakoudis, S.

    The energy is among the characteristics of Ultra High Energy Cosmic Rays (E>5 x 1019 eV) which could be estimated experimentally. The following paper attempts to estimate the energy of an UHECR proton by applying a Monte Carlo simulation code. A number of extensive air showers, vertical and inclined, is simulated to derive the Lateral Distribution Functions of the shower muons. The scenario of simulations is adopted to the Cerenkov surface detector of the P. AUGER Observatory. Due to the fact that the Lateral Distribution Functions show minimal fluctuations of the muon density at a distance larger than 800 m from the core of the showers, and due to the fact that at a distance of 900 m the distribution functions for inclined showers coincide (which means that it does not change with the zenith angle of the showers), we select the muon density at 900 m to derive the energy of the primary protons. (The project is co-funded by the European Social Fund and National Resources (EPEAEK II) PYTHAGORAS II.)

  4. On a possibility of restoration of an arbitrary shape hadron cascade in the atmosphere

    International Nuclear Information System (INIS)

    Kvashnin, A.N.; Rubtsov, V.I.; Smirnov, A.Yu.; Yakovlev, V.I.

    1985-01-01

    A problem of restoring hadron cascade of an arbitrary form in the atmosphere has been considered. The restoration method of hadron cascade is based on using time and amplitude detectors of the Cherenkov radiation. The calculation of the Cherenkov radiation intensity at distances above 200 m from the shower axis was conducted in the approximation of a luminous point model. It is shown that using 5-6 time and amplitude detectors at the above-mentioned distance parameters of a cascade curve can be estimated solving a set of nonlinear equations

  5. Modeling of the Atmospheric Response to the Leonid Meteor Showers

    National Research Council Canada - National Science Library

    McNeil, William

    1998-01-01

    ... showers of recent years. The model allows for ablation, deposition, diffusion and chemical dynamics, thereby permitting the computation of the modifications in the layers due to the showers in a self-consistent manner, based...

  6. Parton shower evolution with subleading color

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2012-02-01

    Parton shower Monte Carlo event generators in which the shower evolves from hard splittings to soft splittings generally use the leading color approximation, which is the leading term in an expansion in powers of 1/N c 2 , where N c =3 is the number of colors. We introduce a more general approximation, the LC+ approximation, that includes some of the color suppressed contributions. There is a cost: each generated event comes with a weight. There is a benefit: at each splitting the leading soft x collinear singularity and the leading collinear singularity are treated exactly with respect to color. In addition, an LC+ shower can start from a state of the color density matrix in which the bra state color and the ket state color do not match. (orig.)

  7. Shower reconstruction in the CLUE experiment

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Bastieri, D.; Bigongiari, C. E-mail: bigongiari@pd.infn.it; Ciocci, M.A.; Cosulich, D.; Cresti, M.; Dokoutchaeva, V.; Kartashov, D.; Liello, F.; Malakhov, N.; Mariotti, M.; Marsella, G.; Menzione, A.; Paoletti, R.; Parlavecchio, G.; Peruzzo, L.; Piccioli, A.; Pegna, R.; Rosso, F.; Sacco, R.; Saggion, A.; Sartori, G.; Sartori, P.; Sbarra, C.; Scribano, A.; Smogailov, E.; Stamerra, A.; Turini, N

    2001-04-01

    The CLUE experiment studies primary cosmic rays (E{>=}2 TeV) by detecting UV (190-230 nm) Cherenkov light produced by atmospheric showers. Since atmospheric absorption in the UV range is higher than in the visible range, CLUE cannot apply algorithms normally used in IACT experiments to determine primary cosmic-ray direction. In this paper, we present a new method developed by CLUE. The algorithm performances were evaluated using simulated showers. Preliminary results of the source analysis using this new method are shown.

  8. Shower reconstruction in the CLUE experiment

    International Nuclear Information System (INIS)

    Bartoli, B.; Bastieri, D.; Bigongiari, C.; Ciocci, M.A.; Cosulich, D.; Cresti, M.; Dokoutchaeva, V.; Kartashov, D.; Liello, F.; Malakhov, N.; Mariotti, M.; Marsella, G.; Menzione, A.; Paoletti, R.; Parlavecchio, G.; Peruzzo, L.; Piccioli, A.; Pegna, R.; Rosso, F.; Sacco, R.; Saggion, A.; Sartori, G.; Sartori, P.; Sbarra, C.; Scribano, A.; Smogailov, E.; Stamerra, A.; Turini, N.

    2001-01-01

    The CLUE experiment studies primary cosmic rays (E≥2 TeV) by detecting UV (190-230 nm) Cherenkov light produced by atmospheric showers. Since atmospheric absorption in the UV range is higher than in the visible range, CLUE cannot apply algorithms normally used in IACT experiments to determine primary cosmic-ray direction. In this paper, we present a new method developed by CLUE. The algorithm performances were evaluated using simulated showers. Preliminary results of the source analysis using this new method are shown

  9. Radio detection of extensive air showers

    Science.gov (United States)

    Huege, Tim

    2017-12-01

    Radio detection of extensive air showers initiated in the Earth's atmosphere has made tremendous progress in the last decade. Today, radio detection is routinely used in several cosmic-ray observatories. The physics of the radio emission in air showers is well-understood, and analysis techniques have been developed to determine the arrival direction, the energy and an estimate for the mass of the primary particle from the radio measurements. The achieved resolutions are competitive with those of more traditional techniques. In this article, I shortly review the most important achievements and discuss the potential for future applications.

  10. Portable Water-Saving Shower For Emergencies

    Science.gov (United States)

    Grenier, Francis E.

    1991-01-01

    Stowable compact unit sprays from many directions. Proposed portable emergency fogging shower rinses harmful chemicals from person. Includes double-walled transparent, approximately cylindrical curtain containing sets of interior nozzles on regularly spaced loops. Sealed at top and bottom. Victim of contamination enters through longitudinal zippered opening. Pressurized mixture of air and water flows through selected nozzles, creating foglike spray scrubbing contaminants from skin and clothing. Intended for use on Space Station, also used in laboratories and factories on Earth, or for routine shower bathing in areas with limited water supplies.

  11. Hadron showers in a highly granular calorimeter

    International Nuclear Information System (INIS)

    Lutz, Benjamin

    2010-11-01

    A future electron-positron collider like the planned International Linear Collider (ILC) needs excellent detectors to exploit the full physics potential. Different detector concepts have been evaluated for the ILC and two concepts on the particle-flow approach were validated. To make particle-flow work, a new type of imaging calorimeters is necessary in combination with a high performance tracking system, to be able to track the single particles through the full detector system. These calorimeters require an unprecedented level of both longitudinal and lateral granularity. Several calorimeter technologies promise to reach the required readout segmentation and are currently studied. This thesis addresses one of these: The analogue hadron calorimeter technology. It combines work on the technological aspects of a highly granular calorimeter with the study of hadron shower physics. The analogue hadron calorimeter technology joins a classical scintillator-steel sandwich design with a modern photo-sensor technology, the silicon photomultiplier (SiPM). The SiPM is a millimetre sized, magnetic field insensitive, and low cost photo-sensor, that opens new possibilities in calorimeter design. This thesis outlines the working principle and characteristics of these devices. The requirements for an application specific integrated circuit (ASIC) to read the SiPM are discussed; the performance of a prototype chip for SiPM readout, the SPIROC, is quantified. Also the SiPM specific reconstruction of a multi-thousand channel prototype calorimeter, the CALICE AHCAL, is explained; the systematic uncertainty of the calibration method is derived. The AHCAL does not only offer a test of the calorimeter technology, it also allows to record hadron showers with an unprecedented level of details. Test-beam measurements have been performed with the AHCAL and provide a unique sample for the development of novel analysis techniques and the validation of hadron shower simulations. A method to

  12. Parton shower evolution with subleading color

    OpenAIRE

    Nagy, Z.; Soper, D. E.

    2012-01-01

    Parton shower Monte Carlo event generators in which the shower evolves from hard splittings to soft splittings generally use the leading color approximation, which is the leading term in an expansion in powers of $1/N_c^2$, where $N_c = 3$ is the number of colors. We introduce a more general approximation, the LC+ approximation, that includes some of the color suppressed contributions. There is a cost: each generated event comes with a weight. There is a benefit: at each splitting the leading...

  13. Implementing NLO DGLAP evolution in parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Höche, Stefan; Krauss, Frank; Prestel, Stefan

    2017-10-01

    We present a parton shower which implements the DGLAP evolution of parton densities and fragmentation functions at next-to-leading order precision up to effects stemming from local four-momentum conservation. The Monte-Carlo simulation is based on including next-to-leading order collinear splitting functions in an existing parton shower and combining their soft enhanced contributions with the corresponding terms at leading order. Soft double counting is avoided by matching to the soft eikonal. Example results from two independent realizations of the algorithm, implemented in the two event generation frameworks Pythia and Sherpa, illustrate the improved precision of the new formalism.

  14. Measurement of parton shower observables with OPAL

    Directory of Open Access Journals (Sweden)

    Fischer N.

    2016-01-01

    Full Text Available A study of QCD coherence is presented based on a sample of about 397,000 e+e- hadronic annihilation events collected at √s = 91 GeV with the OPAL detector at LEP. The study is based on four recently proposed observables that are sensitive to coherence effects in the perturbative regime. The measurement of these observables is presented, along with a comparison with the predictions of different parton shower models. The models include both conventional parton shower models and dipole antenna models. Different ordering variables are used to investigate their influence on the predictions.

  15. Comparison of experimental and calculated spatial distribution functions of charged particles in extensive air showers with particle number of (1-2)x107 at sea level

    International Nuclear Information System (INIS)

    Dedenko, L.G.; Kulikov, G.V.; Solov'eva, V.I.; Sulakov, V.P.; Khristiansen, G.B.

    1985-01-01

    Results of calculations of a spatial distribution function (SDF) of charged particles in extensive air showers (EAS) are given. The calculations have been performed on the basis of a model of quark gluon strings for hadron-hadron interactions. The consideration has been performed for primary protons of cosmic radiation and nuclei with atomic weights A=4, 14, 31, 56 and for three compositions: normal, enriched with protons and enriched with heavy nuclei. When calculating SDF the narrowness of partial showers in electron-photon cascades is taken account of in the case of small finite values of gamma quantum energy, as well as the contributions of muons, decay electrons and delta electrons

  16. Droplet distribution and airborne bacteria in an experimental shower unit.

    Science.gov (United States)

    Estrada-Perez, C E; Kinney, K A; Maestre, J P; Hassan, Y A; King, M D

    2018-03-01

    Although human exposure to water aerosols is common in residential showers, the droplet distribution patterns generated in showers are not well understood nor is the bacteria released during shower operation. In this study, a two-phase flow Particle Tracking Velocimetry (PTV) algorithm was successfully used to characterize the spatial spray pattern and velocity field in two experimental showers (one low-flow and one high-flow). In addition, the airborne bacteria present in the shower over nearly 5 months of controlled operation was determined for both showers. The results indicate that the droplet velocity out of the low-flow showerhead (which had fewer orifices) was significantly higher than that out of the high-flow showerhead resulting in a higher aerosol number concentration in the low-flow shower and more consistent wetting of the shower wall. Both showerheads generated droplets in the respirable range and genera of potential health concern were observed in the shower aerosols measured both prior to and following shower operation. The study provides one of the first visualizations of droplet spray patterns in residential showers and provides insight into the airborne bacteria present in showers. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. 46 CFR 153.216 - Shower and eyewash fountains.

    Science.gov (United States)

    2010-10-01

    ... at all times and meets paragraph (c) of this section. (c) The shower and eyewash fountains required... 46 Shipping 5 2010-10-01 2010-10-01 false Shower and eyewash fountains. 153.216 Section 153.216... Vessel Requirements § 153.216 Shower and eyewash fountains. (a) Each non-self-propelled ship must have a...

  18. Cascade annealing: an overview

    International Nuclear Information System (INIS)

    Doran, D.G.; Schiffgens, J.O.

    1976-04-01

    Concepts and an overview of radiation displacement damage modeling and annealing kinetics are presented. Short-term annealing methodology is described and results of annealing simulations performed on damage cascades generated using the Marlowe and Cascade programs are included. Observations concerning the inconsistencies and inadequacies of current methods are presented along with simulation of high energy cascades and simulation of longer-term annealing

  19. A critical analysis of air shower structure functions and size spectrum measurements with the NBU air shower array

    Science.gov (United States)

    Chaudhuri, N.; Basak, D. K.

    1985-01-01

    A total of 11,000 showers in the size range 10 to the 4 to 10 to the 6 particles so far detected by the NBU air shower array has been analyzed using five different structure functions. A comparison of structure functions in terms: (1) of shower size; and (2) electron density at various core distances has been discussed to indicate the present status of structure functions in air shower analysis.

  20. Pion showers in highly granular calorimeters

    Indian Academy of Sciences (India)

    2012-10-02

    –80 GeV in high granular electromagnetic and hadron calorimeters are presented. Data were used for the first time to investigate the separation of the neutral and charged hadron showers. The result is important to verify the ...

  1. The parametrized simulation of electromagnetic showers

    International Nuclear Information System (INIS)

    Peters, S.

    1992-09-01

    The simulation of electromagnetic showers in calorimeters by detailed tracking of all secondary particles is extremely computer time consuming. Without loosing considerably in precision, the use of parametrizations for global shower properties may reduce the computing time by factors of 10 1 to 10 4 , depending on the energy, the degree of parametrization, and the complexity in the material description and the cut off energies in the detailed simulation. To arrive at a high degree of universality, parametrizations of individual electromagnetic showers in homogeneous media are developed, taking the dependence of the shower development on the material into account. In sampling calorimeters, the inhomogeneous material distribution leads to additional effects which can be taken into account by geometry dependent terms in the parametrization of the longitudinal and radial energy density distributions. Comparisons with detailed simulations of homogeneous and sampling calorimeters show very good agreement in the fluctuations, correlations, and signal averages of spatial energy distributions. Verifications of the algorithms for the simulation of the H1 detector are performed using calorimeter test data for different moduls of the H1 liquid argon calorimeter. Special attention has been paid to electron pion separation, which is of great importance for physics analysis. (orig.) [de

  2. Search for bursts in air shower data

    International Nuclear Information System (INIS)

    Bruce, T.E.G.; Clay, R.W.; Dawson, B.R.; Protheroe, R.J.; Blair, D.G.; Cinquini, P.

    1985-01-01

    There have been reports in recent years of the possible observation of bursts in air shower data. If such events are truly of an astrophysical nature then, they represent an important new class of phemonenon since no other bursts have been observed above the MeV level. The spectra of conventional gamma ray bursts are unknown at higher energies but their observed spectra at MeV energies appear generally to exhibit a steepening in the higher MeV range and are thus unlikely to extrapolate to measurable fluxes at air shower energies. An attempt has been made to look for deviations from randomness in the arrival times of air showers above approx. 10 to the 14th power eV with a number of systems and results so far are presented here. This work will be continued for a substantial period of time with a system capable of recording bursts with multiple events down to a spacing of 4 microns. Earlier data have also been searched for the possible association of air shower events with a glitch of the Vela pulsar

  3. Systematic improvement of QCD parton showers

    CERN Document Server

    Winter, Jan; Hoeth, Hendrik; Krauss, Frank; Schonherr, Marek; Schumann, Steffen; Siegert, Frank; Zapp, Korinna

    2012-01-01

    In this contribution, we will give a brief overview of the progress that has been achieved in the field of combining matrix elements and parton showers. We exemplify this by focusing on the case of electron--positron collisions and by reporting on recent developments as accomplished within the Sherpa event generation framework.

  4. Prenatal showers: educational opportunities for undergraduate students.

    Science.gov (United States)

    Zentz, Suzanne E; Brown, Janet M; Schmidt, Nola A; Alverson, Elise M

    2009-01-01

    J. Cranmer and C. Lajkowicz (1989) faced the challenge of securing student clinical experiences with healthy prenatal clients. They identified that lack of access to pregnant women, limited number of faculty, and large numbers of students contributed to problems in meeting select course objectives. Little has changed since then. This article describes a clinical experience, known as "Prenatal Showers," where undergraduate nursing students, implementing the teacher role, provide community-based prenatal education in the context of a baby shower. Student groups address educational topics identified by community partners. After student presentations, feedback from prenatal clients is analyzed. Lessons learned include selecting appropriate community partners, clearly articulating academic and community needs, and obtaining seed money to initiate the program. Prenatal Showers are most successful when community partners possess open lines of communication, an accessible population, an appreciation for the contributions made by students, and a willingness to share responsibility for their supervision. Prenatal Showers offer different advantages from traditional maternal-child clinical experiences because students gain experiences with prenatal clients from diverse backgrounds and engage in community-based nursing. The community benefits because educational needs of prenatal clients are met. Strong community partnerships benefit faculty by making clinical placements more accessible and reducing faculty workload.

  5. Showering habits: time, steps, and products used after brain injury.

    Science.gov (United States)

    Reistetter, Timothy A; Chang, Pei-Fen J; Abreu, Beatriz C

    2009-01-01

    This pilot study describes the showering habits of people with brain injury (BI) compared with those of people without BI (WBI). The showering habits of 10 people with BI and 10 people WBI were measured and compared. A videotaped session recorded and documented the shower routine. The BI group spent longer time showering, used more steps, and used fewer products than the WBI group. A moderately significant relationship was found between time and age (r = .46, p = .041). Similarly, we found significant correlations between number of steps and number of products used (r = .64, p = .002) and between the number of products used and education (r = .47, p = .044). Results suggest that people with BI have showering habits that differ from those WBI. Correlations, regardless of group, showed that older people showered longer, and people with more education used more showering products.

  6. Modeling RF Emissions from Particle Showers in Dense Mediums

    Science.gov (United States)

    Hyneman, Rachel; Belov, Konstantin; Wissel, Stephanie

    2014-03-01

    The Antarctic Impulsive Transient Antenna (ANITA) experiment has recorded multiple Ultra High Energy Cosmic Ray (UHECR) events via radio-frequency emissions from secondary particle showers in the Earth's atmosphere. The energy of these UHECR particles is reconstructed using Monte Carlo simulations based on first principles. The goal of the SLAC T-510 experiment is to validate these simulations and to provide an energy calibration for ANITA data analysis. We incorporated an RF emission simulation based on ZHS code into the GEANT4 toolkit, used for modeling the passage of particles in accelerator experiments. We predict strong radio emissions at the Cherenkov angle from a cascade of secondary particles in a polyethylene target in moderate magnetic fields. We see a strong dependence of the horizontally polarized component of the electric field on top of the Cherenkov cone on the magnetic field strength. We also observe a skewing of the Cherenkov cone as the magnetic field increases, which we believe to be an indication of the Askaryan effect. Special thanks to the National Science Foundation and the Research Experience for Undergraduates program.

  7. Photoexcitation cascade and quantum-relativistic jet formation in graphene

    Science.gov (United States)

    Lewandowski, Cyprian; Levitov, Leonid

    Interactions between ultra-relativistic particles can lead to striking behavior in which a high-energy particle creates showers of softer particles characterized by a collimated angular distribution aligned with the particle velocity. These showers, known as jets, are a generic phenomenon relevant for all quantum cascades of linearly dispersing particles. This talk will discuss jets formed upon photoexcitation in graphene, which due to its linear dispersion provides an appealing medium for exploring quantum-relativistic phenomena. We will study the cascade generated by carrier-carrier collisions in photon absorption, wherein a single photon creates an electron-hole (e-h) excitation that decays producing multiple near-collinear secondary e-h excitations. We will argue that the cascade can occur through an off-shell mechanism such that all the particles and holes involved reside outside the energy-momentum dispersion manifold, relieving the bottleneck arising in the on-shell process due to energy and momentum conservation. The characteristics of the jets such as the angular and energy distribution of the particles will be discussed. Photogenerated jets provide an interesting setting to investigate the carrier-carrier collision processes in graphene and other Dirac materials. We acknowledge support of the Center for Integrated Quantum Materials (CIQM) under NSF award DMR-1231319.

  8. Universality of Electron Distributions in Extensive Air Showers

    Science.gov (United States)

    Śmiałkowski, Andrzej; Giller, Maria

    2018-02-01

    Based on extensive air shower simulations, it is shown that electron distributions with respect to two angles determining the electron direction at a given shower age, for a fixed electron energy and lateral distance, are universal. This means that the distributions do not depend on the primary particle energy or mass (thus, neither on the interaction model), shower zenith angle, or shower to shower fluctuations, if they are taken at the same shower age. Together with previous work showing the universality of the distributions of the electron energy, lateral distance (integrated over angles), and angle (integrated over lateral distance) for fixed electron energy, this paper completes a full universal description of the electron states at various shower ages. Analytical parametrizations of the full electron states are given. It is also shown that some distributions can be described by a number of variables smaller than five, with the new ones being products of old ones raised to some power. The accuracy of the present parametrization is sufficiently good to apply to showers with a primary energy uncertainty of 14% (as is the case at the Pierre Auger Observatory). The shower fluctuations in the chosen bins of the multidimensional variable space are about 6%, determining the minimum uncertainty needed for the parametrization of the universal distributions. An analytical way of estimating the effect of the geomagnetic field is given. Thanks to the universality of the electron distribution in any shower, a new method of shower reconstruction can be worked out from the data from observatories using the fluorescence technique. The light fluxes (both fluorescence and Cherenkov) for any shower age can be exactly predicted for a shower with any primary energy and shower maximum depth, so that the two quantities can be obtained by best fitting the predictions to the measurements.

  9. Study of 'Track-Time' complementarity in the longitudinal development of Extensive Air Showers

    International Nuclear Information System (INIS)

    Procureur, J.; Dumora, D.

    1997-01-01

    Among the various Extensive Air Showers (EAS) observables only three are composed of penetrant particles: Cherenkov photons, muons and neutrinos. Due to their high penetration strength the information related to their creation is practically conserved undeformed. Due to difficulties of observation, the neutrinos have not been used until now. The photons were largely observed in the last years either by Cherenkov effect for the low energies or by scintillation effect for the ultra-high energies. We think that the muons present serious advantages relative to photons: their characteristics are more sensible to the EAS initial development and consequently to the mass of cosmic projectiles generating the showers and to the nature of the interactions at ultra-high energy, they represent directly the development of the hadron cascades with no intervention from electromagnetic interactions, they can be observed continuously, not only during the nights without moon and clouds. Although, the muons are much fewer than the photons, hence, larger fluctuations will affect their analysis. We have simulated by Monte Carlo modelling the individual propagation of the each EAS muon. Actually, we have determined the distribution of depths of the muon creation in the earth atmosphere by taking into account the coordinates and directions (Track) and the differences in the muon arrival moments (Time). We have shown that at large distances from the shower core and for muons having energies of GeV order, the measurements of tracks and times are complementary (the TTC complementarity) in determining the depths of the muon creation with a accuracy of 35 g.cm -2 . This TTC complementarity entails important consequences in determining the core localization of the giant shower in the observation plane

  10. On a spatial distribution function of electron-photon shower particles for different values of Esub(0)/#betta# in isothermal atmosphere

    International Nuclear Information System (INIS)

    Ivanenko, I.P.; Osipova, L.N.; Roganova, T.M.; Fedorova, G.F.

    1982-01-01

    Results of calculations of scape distribution function (SDF) of electron-photon shower particles for different values of a parameter E 0 /#betta# in isothermal atmosphere are given. Consideration of finiteness of the parameter E 0 /#betta# leads to narrowing of SDF two times at E 0 /#betta# approximately 10-100 as compared with the Nishimura, Kamata, Greisen SDF (E 0 /#betta# = infinity). Atmosphere inhomogeneity results in SDF broadening in comparison with SDFsub(hom) (E 0 /#betta#) calculated for homogeneous atmosphere. SDFsub(inhom) (E 0 /#betta#) and SDFsub(hom) (E 0 /#betta#) depend on E 0 /#betta# differently which is attributed to different contributions of shower prehistory to SDF formation. The larger is E 0 /#betta# the wider is cascade curve and the higher is the effect of shower prehistory

  11. Deep cascade learning

    OpenAIRE

    Marquez, Enrique, Salvador; Hare, Jonathon; Niranjan, Mahesan

    2018-01-01

    In this paper, we propose a novel approach for efficient training of deep neural networks in a bottom-up fashion using a layered structure. Our algorithm, which we refer to as Deep Cascade Learning, is motivated by the Cascade Correlation approach of Fahlman who introduced it in the context of perceptrons. We demonstrate our algorithm on networks of convolutional layers, though its applicability is more general. Such training of deep networks in a cascade, directly circumvents the well-know...

  12. Helicity antenna showers for hadron colliders

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Nadine; Skands, Peter [Monash University, School of Physics and Astronomy, Clayton, VIC (Australia); Lifson, Andrew [Monash University, School of Physics and Astronomy, Clayton, VIC (Australia); ETH Zuerich, Zurich (Switzerland)

    2017-10-15

    We present a complete set of helicity-dependent 2 → 3 antenna functions for QCD initial- and final-state radiation. The functions are implemented in the Vincia shower Monte Carlo framework and are used to generate showers for hadron-collider processes in which helicities are explicitly sampled (and conserved) at each step of the evolution. Although not capturing the full effects of spin correlations, the explicit helicity sampling does permit a significantly faster evaluation of fixed-order matrix-element corrections. A further speed increase is achieved via the implementation of a new fast library of analytical MHV amplitudes, while matrix elements from Madgraph are used for non-MHV configurations. A few examples of applications to QCD 2 → 2 processes are given, comparing the newly released Vincia 2.200 to Pythia 8.226. (orig.)

  13. Helicity antenna showers for hadron colliders

    Science.gov (United States)

    Fischer, Nadine; Lifson, Andrew; Skands, Peter

    2017-10-01

    We present a complete set of helicity-dependent 2→ 3 antenna functions for QCD initial- and final-state radiation. The functions are implemented in the Vincia shower Monte Carlo framework and are used to generate showers for hadron-collider processes in which helicities are explicitly sampled (and conserved) at each step of the evolution. Although not capturing the full effects of spin correlations, the explicit helicity sampling does permit a significantly faster evaluation of fixed-order matrix-element corrections. A further speed increase is achieved via the implementation of a new fast library of analytical MHV amplitudes, while matrix elements from Madgraph are used for non-MHV configurations. A few examples of applications to QCD 2→ 2 processes are given, comparing the newly released Vincia 2.200 to Pythia 8.226.

  14. Characterizing the 2016 Perseid Meteor Shower Outburst

    Science.gov (United States)

    Blaauw, R. C.; Moser, D. E.; Ehlert, S. R.; Kingery, A. M.; Molau, S.; Schult, C.; Stober, G.

    2017-01-01

    The Perseid meteor shower has been observed for millennia and known for its visually spectacular meteors and occasional outbursts. The Perseids were expected to outburst in 2016, primarily due to particles released during the 1862 and 1479 revolutions of Comet Swift-Tuttle. NASA's Meteoroid Environment Office predicted the timing, strength and duration of the outburst for spacecraft risk using the MSFC Meteoroid Stream Model. A double peak was predicted, with an outburst displaying a ZHR of 210 +/- 50 at 00:30 UTC Aug 12, and a traditional peak approximately 12 hours later with rates still heightened from the outburst. Video, visual, and radar observations taken worldwide by various entities were used to characterize the shower and compare to predictions.

  15. Triple collinear emissions in parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Höche, Stefan; Prestel, Stefan

    2017-10-01

    A framework to include triple collinear splitting functions into parton showers is presented, and the implementation of flavor-changing NLO splitting kernels is discussed as a first application. The correspondence between the Monte-Carlo integration and the analytic computation of NLO DGLAP evolution kernels is made explicit for both timelike and spacelike parton evolution. Numerical simulation results are obtained with two independent implementations of the new algorithm, using the two independent event generation frameworks Pythia and Sherpa.

  16. Cascaded automatic target recognition (Cascaded ATR)

    Science.gov (United States)

    Walls, Bradley

    2010-04-01

    The global war on terror has plunged US and coalition forces into a battle space requiring the continuous adaptation of tactics and technologies to cope with an elusive enemy. As a result, technologies that enhance the intelligence, surveillance, and reconnaissance (ISR) mission making the warfighter more effective are experiencing increased interest. In this paper we show how a new generation of smart cameras built around foveated sensing makes possible a powerful ISR technique termed Cascaded ATR. Foveated sensing is an innovative optical concept in which a single aperture captures two distinct fields of view. In Cascaded ATR, foveated sensing is used to provide a coarse resolution, persistent surveillance, wide field of view (WFOV) detector to accomplish detection level perception. At the same time, within the foveated sensor, these detection locations are passed as a cue to a steerable, high fidelity, narrow field of view (NFOV) detector to perform recognition level perception. Two new ISR mission scenarios, utilizing Cascaded ATR, are proposed.

  17. Collective behavior in nuclear interactions and shower development

    CERN Document Server

    Canoa, V.; Pajares, C.; Vazquez, Ricardo A.

    2005-01-01

    The mechanism of hadronic interactions at very high energies is still unclear. Available accelerator data constrain weakly the forward rapidity region which determines the development of atmospheric showers. This ignorance is one of the main sources of uncertainty in the determination of the energy and composition of the primary in hadron-induced atmospheric showers. In this paper we examine the effect on the shower development of two kinds of collective effects in high-energy hadronic interactions which modify the production of secondary particles. The first mechanism, modeled as string fusion, affects strongly the central rapidity region but only slightly the forward region and is shown to have very little effect on the shower development. The second mechanism implies a very strong stopping; it affects modestly the profile of shower maximum but broadens considerably the number distribution of muons at ground. For the latter mechanism, the development of air showers is faster mimicking a heavier projectile. ...

  18. Depth Distribution Of The Maxima Of Extensive Air Shower

    Science.gov (United States)

    Adams, J. H.; Howell, L. W.

    2003-01-01

    Observations of the extensive air showers from space can be free from interference by low altitude clouds and aerosols if the showers develop at a sufficiently high altitude. In this paper we explore the altitude distribution of shower maxima to determine the fraction of all showers that will reach their maxima at sufficient altitudes to avoid interference from these lower atmosphere phenomena. Typically the aerosols are confined within a planetary boundary layer that extends from only 2-3 km above the Earth's surface. Cloud top altitudes extend above 15 km but most are below 4 km. The results reported here show that more than 75% of the showers that will be observed by EUSO have maxima above the planetary boundary layer. The results also show that more than 50% of the showers that occur on cloudy days have their maxima above the cloud tops.

  19. Final state dipole showers and the DGLAP equation

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2009-01-01

    We study a parton shower description, based on a dipole picture, of the final state in electron-positron annihilation. In such a shower, the distribution function describing the inclusive probability to find a quark with a given energy depends on the shower evolution time. Starting from the exclusive evolution equation for the shower, we derive an equation for the evolution of the inclusive quark energy distribution in the limit of strong ordering in shower evolution time of the successive parton splittings. We find that, as expected, this is the DGLAP equation. This paper is a response to a recent paper of Dokshitzer and Marchesini that raised troubling issues about whether a dipole based shower could give the DGLAP equation for the quark energy distribution.

  20. Parton distribution functions in the context of parton showers

    International Nuclear Information System (INIS)

    Nagy, Zoltán; Soper, Davison E.

    2014-01-01

    When the initial state evolution of a parton shower is organized according to the standard “backward evolution” prescription, ratios of parton distribution functions appear in the splitting probabilities. The shower thus organized evolves from a hard scale to a soft cutoff scale. At the end of the shower, one expects that only the parton distributions at the soft scale should affect the results. The other effects of the parton distributions should have cancelled. This means that the kernels for parton evolution should be related to the shower splitting functions. If the initial state partons can have non-zero masses, this requires that the evolution kernels cannot be the usual (MS)-bar kernels. We work out what the parton evolution kernels should be to match the shower evolution contained in the parton shower event generator DEDUCTOR, in which the b and c quarks have non-zero masses.

  1. Physiological and subjective responses to standing showers, sitting showers, and sink baths.

    Science.gov (United States)

    Ohnaka, T; Tochihara, Y; Kubo, M; Yamaguchi, C

    1995-09-01

    The purpose of this study was to investigate physiological and subjective responses during and after bathing in three different bathing methods. Eight healthy males bathed for 10 minutes, and then rested for 30 minutes. Three kinds of bathing methods - standing shower, sitting shower and sink bath - were adopted in this experiment. Water temperature and flow volume of the showers were kept at 41 degrees C and 11 liter/min, while water temperature of the bath was kept at 40 degrees C. Rectal temperature, skin temperatures and heart rate of the subjects were measured continuously during bathing and the subsequent 30-minute rest. Blood pressure and votes for thermal sensations were recorded before bathing, after 5 and 10 minutes of bathing, and 5, 10, 20 and 30 minutes after bathing. The following results were obtained. 1) Although rectal temperature rose, on the average, by 0.15 degrees C in all bathing methods, there were no significant differences among the three bathing methods at any time in the experiment. 2) Mean skin temperature (Tsk) during the sink bath was significantly higher than that in the standing or sitting shower. After bathing, Tsk of sink bath was slightly higher than those of the remaining conditions, but did not significantly differ among the bathing methods. 3) Heart rate increased gradually during all the bathing methods, however, only HR in the standing shower exceeded 100 beats/min which was significantly higher than those of the two remaining bathing methods. 4) Blood pressure (BP) decreased rapidly during the sink bath in contrast to an increased BP in the sitting and standing showers.

  2. Parton Shower Uncertainties with Herwig 7: Benchmarks at Leading Order

    CERN Document Server

    Bellm, Johannes; Plätzer, Simon; Schichtel, Peter; Siódmok, Andrzej

    2016-01-01

    We perform a detailed study of the sources of perturbative uncertainty in parton shower predictions within the Herwig 7 event generator. We benchmark two rather different parton shower algorithms, based on angular-ordered and dipole-type evolution, against each other. We deliberately choose leading order plus parton shower as the benchmark setting to identify a controllable set of uncertainties. This will enable us to reliably assess improvements by higher-order contributions in a follow-up work.

  3. Mechanisms of cascade collapse

    International Nuclear Information System (INIS)

    Diaz de la Rubia, T.; Smalinskas, K.; Averback, R.S.; Robertson, I.M.; Hseih, H.; Benedek, R.

    1988-12-01

    The spontaneous collapse of energetic displacement cascades in metals into vacancy dislocation loops has been investigated by molecular dynamics (MD) computer simulation and transmission electron microscopy (TEM). Simulations of 5 keV recoil events in Cu and Ni provide the following scenario of cascade collapse: atoms are ejected from the central region of the cascade by replacement collision sequences; the central region subsequently melts; vacancies are driven to the center of the cascade during resolidification where they may collapse into loops. Whether or not collapse occurs depends critically on the melting temperature of the metal and the energy density and total energy in the cascade. Results of TEM are presented in support of this mechanism. 14 refs., 4 figs., 1 tab

  4. Momentum conservation and unitarity in parton showers and NLL resummation

    Science.gov (United States)

    Höche, Stefan; Reichelt, Daniel; Siegert, Frank

    2018-01-01

    We present a systematic study of differences between NLL resummation and parton showers. We first construct a Markovian Monte-Carlo algorithm for resummation of additive observables in electron-positron annihilation. Approximations intrinsic to the pure NLL result are then removed, in order to obtain a traditional, momentum and probability conserving parton shower based on the coherent branching formalism. The impact of each approximation is studied, and an overall comparison is made between the parton shower and pure NLL resummation. Differences compared to modern parton-shower algorithms formulated in terms of color dipoles are analyzed.

  5. Time-domain radio pulses from particle showers

    International Nuclear Information System (INIS)

    Alvarez-Muñiz, Jaime; Romero-Wolf, Andrés; Zas, Enrique

    2012-01-01

    The time-domain properties of the far-field coherent radio emission from electromagnetic showers are studied in depth. A purely time-domain technique for mapping the electromagnetic fields of charged tracks is developed. The method is applied to the ZHS shower code to produce electric fields. It is demonstrated that the technique is equivalent to the frequency domain methods used in the ZHS code and produces consistent results. In addition, a model for mapping the longitudinal charge profile of a shower to a time-domain electromagnetic field is developed. It is shown that the model is in good agreement to the results of shower simulation.

  6. Aspects of perturbative QCD in Monte Carlo shower models

    International Nuclear Information System (INIS)

    Gottschalk, T.D.

    1986-01-01

    The perturbative QCD content of Monte Carlo models for high energy hadron-hadron scattering is examined. Particular attention is given to the recently developed backwards evolution formalism for initial state parton showers, and the merging of parton shower evolution with hard scattering cross sections. Shower estimates of K-factors are discussed, and a simple scheme is presented for incorporating 2 → QCD cross sections into shower model calculations without double counting. Additional issues in the development of hard scattering Monte Carlo models are summarized. 69 references, 20 figures

  7. [Shower PUVA: a new possibility for topical PUVA therapy. Phototoxicity in relation to shower time, water temperature and skin type].

    Science.gov (United States)

    Radenhausen, M; Tebbe, B; Orfanos, C E

    1999-10-01

    During the past few years, bath PUVA has become established as an effective treatment for various dermatoses and especially for psoriasis. Using 3,4,5 trimethylpsoralen (TMP) in combination with subsequent UVA irradiation, a shower PUVA has been developed as an alternative in local PUVA therapy. This involves moistening the patient's skin - with the exception of the head and neck area - in a shower using water containing psoralen (TMP concentration 0,27 mg/l). The advantages of shower PUVA method are that time, space and cost savings are possible and that only a slight amount of physical exertion is required by the patient standing in the shower compared to immersing the whole body during bath PUVA therapy. The efficacy and practicability of shower PUVA were evaluated using the minimal phototoxic dose (MPD) for healthy volunteers assessing water temperature (33-38 degrees C), shower time (5-10 min), and UVA dose (0,06-1,0 J/cm(2)). Additionally, the time course of TMP-induced photosensitivity was observed over a period of 4 hours after the shower. Using a TMP concentration of 0,27 mg/l, the MPD for skin type I-II lay between 0,125-0,375 J/cm(2) and for skin type III-IV between 0,375-1,0 J/cm(2). Photosensitivity was induced by shower PUVA within 5-10 minutes shower time and at 33-38 degrees C water temperature. MPD exhibited an inverse correlation to temperature but no differences were apparent for shower times between 5 and 10 minutes. Photosensitivity completely disappeared within 2 hours. Minimal phototoxic doses using TMP in shower PUVA are comparable with classical bath PUVA when taking skin type into account. These results support the therapeutic use of shower PUVA using TMP.

  8. Comparison of γ-families properties at the observation level with the calculations of nuclear-electromagnetic cascade in the atmosphere

    International Nuclear Information System (INIS)

    Anon.

    1977-01-01

    The results of cosmic cascade detection with X-ray chambers are compared with the results of the calculations. Four models of cascade mechanism are used: large dissipation, inclusive scaling, fireball scaling, scaling with charge exchange. Such a parameters of the cosmic showers as the total energy integrated spectra, multiplicity distribution, fractional energy spectra and spatial distribution from the experiment and from calculations are compared. (S.B.)

  9. Fractal Dimension of Particle Showers Measured in a Highly Granular Calorimeter

    CERN Document Server

    Ruan, Manqi; Bourdy, Vincent; Brients, Jean-Claude; Videau, Henri

    2014-01-01

    fractal dimension of showers measured in a high granularity calorimeter designed for a future lepton collider. The shower fractal dimension reveals detailed information of the spatial configuration of the shower. It is found to be characteristic of the type of interaction and highly sensitive to the nature of the incident particle. Using the shower fractal dimension, we demonstrate a particle identification algorithm that can efficiently separate electromagnetic showers, hadronic showers and non-showering tracks. We also find a logarithmic dependence of the shower fractal dimension on the particle energy.

  10. The 2014 May Camelopardalid Meteor Shower

    Science.gov (United States)

    Cooke, Bill; Moser, Danielle

    2014-01-01

    On May 24, 2014 Earth will encounter multiple streams of debris laid down by Comet 209P LINEAR. This will likely produce a new meteor shower, never before seen. Rates predicted to be from 100 to 1000 meteors per hour between 2 and 4 AM EDT, so we are dealing with a meteor outburst, potentially a storm. Peak rate of 200 per hour best current estimate. Difficult to calibrate models due to lack of past observations. Models indicate mm size particles in stream, so potential risk to Earth orbiting spacecraft.

  11. Meteor Showers of the Earth-crossing Asteroids

    Science.gov (United States)

    Pulat, Babadzhanov; Gulchekhra, Kokhirova

    2015-03-01

    The results of search for meteor showers associated with the asteroids crossing the Earthfs orbit and moving on comet-like orbits are given. It was shown that among 2872 asteroids discovered till 1.01.2005 and belonging to the Apollo and Amor groups, 130 asteroids have associated meteor showers and, therefore, are the extinct cometary nuclei.

  12. Cosmic ray air showers in the knee energy region

    Indian Academy of Sciences (India)

    Abstract. The cosmic ray extensive air showers in the knee energy region have been studied by the. North Bengal University array. The differential size spectra at different atmospheric depths show a systematic shift of the knee towards smaller shower size with the increase in atmospheric depth. The measured values of ...

  13. Methicillin-resistant Staphylococcus aureus in pork production shower facilities.

    Science.gov (United States)

    Leedom Larson, Kerry R; Harper, Abby L; Hanson, Blake M; Male, Michael J; Wardyn, Shylo E; Dressler, Anne E; Wagstrom, Elizabeth A; Tendolkar, Shaliesh; Diekema, Daniel J; Donham, Kelley J; Smith, Tara C

    2011-01-01

    As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746.

  14. AIR TOXICS EMISSIONS FROM A VINYL SHOWER CURTAIN

    Science.gov (United States)

    The paper reports results of both static and dynamic chamber tests conducted to evaluate emission characteristics of air toxics from a vinyl shower Curtain. (NOTE: Due to the relatively low price and ease of installation, vinyl shower curtains have been widely used in bathrooms i...

  15. Testing the Effectiveness of Therapeutic Showering in Labor.

    Science.gov (United States)

    Stark, Mary Ann

    : Therapeutic showering is a holistic nursing intervention that is often available and supports physiologic labor. The purpose of this study was to compare the effectiveness of therapeutic showering with usual care during active labor. Research questions were as follows: Are there significant differences between women who showered 30 minutes during active labor and those who received usual labor care in anxiety, tension, relaxation, pain, discomfort, and coping? Is there a difference in use of obstetric interventions between groups? A convenience sample of healthy low-risk women in active labor was recruited (N = 32). A pretest posttest control group repeated-measures design was used. Participants were randomized to treatment group (n = 17), who showered for 30 minutes, or to control group (n = 14) who received usual labor care. Women evaluated pain, discomfort, anxiety, tension, coping, and relaxation at enrollment, again 15 minutes after entering the shower or receiving usual care, then again 30 minutes after entering the shower or receiving usual care. Chart reviews after delivery recorded obstetric interventions. The showering group had statistically significant decreases in pain, discomfort, anxiety and tension, and significant increase in relaxation. There were no differences in use of obstetric interventions. Therapeutic showering was effective in reducing pain, discomfort, anxiety, and tension while improving relaxation and supporting labor in this sample.

  16. Cosmic ray air showers in the knee energy region

    Indian Academy of Sciences (India)

    The cosmic ray extensive air showers in the knee energy region have been studied by the North Bengal University array. The differential size spectra at different atmospheric depths show a systematic shift of the knee towards smaller shower size with the increase in atmospheric depth. The measured values of spectral ...

  17. Biocatalysis: Chiral cascades

    Science.gov (United States)

    Wang, Jian-Bo; Reetz, Manfred T.

    2015-12-01

    Racemic or enantiomerically pure alcohols can be converted with high yield into enantiopure chiral amines in a one-pot redox-neutral cascade process by the clever combination of an alcohol dehydrogenase and an appropriate amine dehydrogenase.

  18. Conjugation of cascades

    International Nuclear Information System (INIS)

    San Martin, Jesus; Rodriguez-Perez, Daniel

    2009-01-01

    Presented in this work are some results relative to sequences found in the logistic equation bifurcation diagram, which is the unimodal quadratic map prototype. All of the different saddle-node bifurcation cascades, associated with every last appearance p-periodic orbit (p=3,4,5,...), can also be generated from the very Feigenbaum cascade. In this way it is evidenced the relationship between both cascades. The orbits of every saddle-node bifurcation cascade, mentioned above, are located in different chaotic bands, and this determines a sequence of orbits converging to every band-merging Misiurewicz point. In turn, these accumulation points form a sequence whose accumulation point is the Myrberg-Feigenbaum point. It is also proven that the first appearance orbits in the n-chaotic band converge to the same point as the last appearance orbits of the (n + 1)-chaotic band. The symbolic sequences of band-merging Misiurewicz points are computed for any window.

  19. Particle Showers in a Highly Granular Hadron Calorimeter

    CERN Document Server

    Simon, Frank

    2010-01-01

    The CALICE collaboration has constructed highly granular electromagnetic and hadronic calorimeter prototypes to evaluate technologies for the use in detector systems at a future Linear Collider. The hadron calorimeter uses small scintillator cells individually read out with silicon photomultipliers. The system with 7608 channels has been successfully operated in beam tests at DESY, CERN and Fermilab since 2006, and represents the first large scale tests of these devices in high energy physics experiments. The unprecedented granularity of the detector provides detailed information of the properties of hadronic showers, which helps to constrain hadronic shower models through comparisons with model calculations. We will discuss results on longitudinal and lateral shower profiles compared to a variety of different shower models, and present studies of the energy reconstruction of hadronic showers using software compensation techniques.

  20. Hadron shower profile and direction measurements in a segmented calorimeter

    International Nuclear Information System (INIS)

    Auchincloss, P.; Blair, R.; Haber, C.

    1982-01-01

    Recently a test measurement was made to see how well the direction of the shower induced by neutrino interactions could be determined in the lab-E detector at Fermilab. While the calorimeter in lab-E has very coarse sampling compared to the detectors described at this workshop, the method used to sample the shower could be employed in other more finely segmented detectors. The shower angle resolution obtained (36 mr.FWHM) is largely constrained by the sampling. In this test pulse heights in 2mm. steps across the hadron shower at five points along the shower were recorded. This was done with 20 wires and 20 fast ADC's. A standard MWPC system intended to accomplish the same task would have required about 250 wires and 250 ADC channels. This considerable saving in system complexity should be possible for any system where finely segmented pulse height measurements are required

  1. Hadronic shower development in Iron-Scintillator Tile Calorimetry

    Energy Technology Data Exchange (ETDEWEB)

    Amaral, P.; Amorim, A.; Anderson, K.; Barreira, G.; Benetta, R.; Berglund, S.; Biscarat, C.; Blanchot, G.; Blucher, E.; Bogush, A.; Bohm, C.; Boldea, V.; Borisov, O.; Bosman, M.; Bromberg, C.; Budagov, J.; Burdin, S.; Caloba, L.; Carvalho, J.; Casado, P.; Castillo, M.V.; Cavalli-Sforza, M.; Cavasinni, V.; Chadelas, R.; Chirikov-Zorin, I.; Chlachidze, G.; Cobal, M.; Cogswell, F.; Colaco, F.; Cologna, S.; Constantinescu, S.; Costanzo, D.; Crouau, M.; Daudon, F.; David, J.; David, M.; Davidek, T.; Dawson, J.; De, K.; Del Prete, T.; De Santo, A.; Di Girolamo, B.; Dita, S.; Dolejsi, J.; Dolezal, Z.; Downing, R.; Efthymiopoulos, I.; Engstroem, M.; Errede, D.; Errede, S.; Evans, H.; Fenyuk, A.; Ferrer, A.; Flaminio, V.; Gallas, E.; Gaspar, M.; Gil, I.; Gildemeister, O.; Glagolev, V.; Gomes, A.; Gonzalez, V.; Gonzalez De La Hoz, S.; Grabski, V.; Grauges, E.; Grenier, P.; Hakopian, H.; Haney, M.; Hansen, M.; Hellman, S.; Henriques, A.; Hebrard, C.; Higon, E.; Holmgren, S.; Huston, J.; Ivanyushenkov, Yu.; Jon-And, K.; Juste, A.; Kakurin, S.; Karapetian, G.; Karyukhin, A.; Kopikov, S.; Kukhtin, V.; Kulchitsky, Y.; Kurzbauer, W.; Kuzmin, M.; Lami, S.; Lapin, V.; Lazzeroni, C.; Lebedev, A.; Leitner, R.; Li, J.; Lomakin, Yu.; Lomakina, O.; Lokajicek, M.; Lopez Amengual, J.M.; Maio, A.; Malyukov, S.; Marroquin, F.; Martins, J.P.; Mazzoni, E.; Merritt, F.; Miller, R.; Minashvili, I.; Miralles, Ll.; Montarou, G.; Munar, A.; Nemecek, S.; Nessi, M. E-mail: marzio.nessi@cern.ch; Onofre, A.; Orteu, S.; Park, I.C.; Pallin, D.; Pantea, D.; Paoletti, R.; Patriarca, J.; Pereira, A.; Perlas, J.A.; Petit, P.; Pilcher, J.; Pinhao, J.; Poggioli, L.; Price, L.; Proudfoot, J.; Pukhov, O.; Reinmuth, G.; Renzoni, G.; Richards, R.; Roda, C.; Romance, J.B.; Romanov, V.; Ronceux, B.; Rosnet, P.; Rumyantsev, V.; Russakovich, N.; Sanchis, E.; Sanders, H.; Santoni, C.; Santos, J.; Sawyer, L.; Says, L.-P.; Seixas, J.M.; Sellden, B.; Semenov, A.; Shchelchkov, A.; Shochet, M.; Simaitis, V. [and others

    2000-03-21

    The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter presents a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behaviour is obtained. The underlying radial energy densities for the four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrisation has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeters design.

  2. Observation of particles delayed long times after extensive air showers

    International Nuclear Information System (INIS)

    Smith, G.R.; Standil, S.

    1976-01-01

    A large aperture, five element cosmic ray telescope was operated in conjunction with an air shower array in a search for long lived particles, delayed between 1 and 45 μs after extensive air showers. After sampling approximately 29 000 air showers with an energy greater than approximately 10 14 eV, over a period of 9 months, an excess of 11 such events were observed with time delays in the interval of 1 to 6 μs following the showers. The events in the remainder of the 45 μs interval were consistent with background random coincidences. We estimate that only 1 of the 11 excess events might be attributable to afterpulsing in our telescope photomultiplier tubes. All the excess 'trailing particle' events can be explained as being due to electrons resulting from shower associated muons that stop and decay in the vicinity of the cosmic ray telescope. (author)

  3. Hadronic Shower Development in Iron-Scintillator Tile Calorimetry

    CERN Document Server

    Amaral, P; Anderson, K; Barreira, G; Benetta, R; Berglund, S; Biscarat, C; Blanchot, G; Blucher, E; Bogush, A A; Bohm, C; Boldea, V; Borisov, O; Bosman, M; Bromberg, C; Budagov, Yu A; Burdin, S; Caloba, L; Carvalho, J; Casado, M P; Castillo, M V; Cavalli-Sforza, M; Cavasinni, V; Chadelas, R; Chirikov-Zorin, I E; Chlachidze, G; Cobal, M; Cogswell, F; Colaço, F; Cologna, S; Constantinescu, S; Costanzo, D; Crouau, M; Daudon, F; David, J; David, M; Davidek, T; Dawson, J; De, K; Del Prete, T; De Santo, A; Di Girolamo, B; Dita, S; Dolejsi, J; Dolezal, Z; Downing, R; Efthymiopoulos, I; Engström, M; Errede, D; Errede, S; Evans, H; Fenyuk, A; Ferrer, A; Flaminio, V; Gallas, E; Gaspar, M; Gil, I; Gildemeister, O; Glagolev, V; Gomes, A; González, V; González de la Hoz, S; Grabskii, V; Graugès-Pous, E; Grenier, P; Hakopian, H H; Haney, M; Hansen, M; Hellman, S; Henriques, A; Hébrard, C; Higón, E; Holmgren, S O; Huston, J; Ivanyushenkov, Yu M; Jon-And, K; Juste, A; Kakurin, S; Karapetian, G V; Karyukhin, A N; Kopikov, S; Kukhtin, V; Kulchitskii, Yu A; Kurzbauer, W; Kuzmin, M; Lami, S; Lapin, V; Lazzeroni, C; Lebedev, A; Leitner, R; Li, J; Lomakin, Yu F; Lomakina, O V; Lokajícek, M; López-Amengual, J M; Maio, A; Malyukov, S; Marroquin, F; Martins, J P; Mazzoni, E; Merritt, F S; Miller, R; Minashvili, I A; Miralles, L; Montarou, G; Munar, A; Némécek, S; Nessi, Marzio; Onofre, A; Orteu, S; Park, I C; Pallin, D; Pantea, D; Paoletti, R; Patriarca, J; Pereira, A; Perlas, J A; Petit, P; Pilcher, J E; Pinhão, J; Poggioli, L; Price, L; Proudfoot, J; Pukhov, O; Reinmuth, G; Renzoni, G; Richards, R; Roda, C; Romance, J B; Romanov, V; Ronceux, B; Rosnet, P; Rumyantsev, V; Rusakovich, N; Sanchis, E; Sanders, H; Santoni, C; Santos, J; Sawyer, L; Says, L P; Seixas, J M; Selldén, B; Semenov, A; Shchelchkov, A S; Shochet, M; Simaitis, V; Sissakian, A N; Solodkov, A; Solovyanov, O; Sonderegger, P; Sosebee, M; Soustruznik, K; Spanó, F; Stanek, R; Starchenko, E A; Stephens, R; Suk, M; Tang, F; Tas, P; Thaler, J; Tokar, S; Topilin, N; Trka, Z; Turcot, A S; Turcotte, M; Valkár, S; Varandas, M J; Vartapetian, A H; Vazeille, F; Vichou, I; Vinogradov, V; Vorozhtsov, S B; Wagner, D; White, A; Wolters, H; Yamdagni, N; Yarygin, G; Yosef, C; Zaitsev, A; Zdrazil, M; Zúñiga, J

    2000-01-01

    The lateral and longitudinal profiles of hadronic showers detected by a prototype of the ATLAS Iron-Scintillator Tile Hadron Calorimeter have been investigated. This calorimeter uses a unique longitudinal configuration of scintillator tiles. Using a fine-grained pion beam scan at 100 GeV, a detailed picture of transverse shower behavior is obtained. The underlying radial energy densities for four depth segments and for the entire calorimeter have been reconstructed. A three-dimensional hadronic shower parametrization has been developed. The results presented here are useful for understanding the performance of iron-scintillator calorimeters, for developing fast simulations of hadronic showers, for many calorimetry problems requiring the integration of a shower energy deposition in a volume and for future calorimeter design.

  4. Learning optimal embedded cascades.

    Science.gov (United States)

    Saberian, Mohammad Javad; Vasconcelos, Nuno

    2012-10-01

    The problem of automatic and optimal design of embedded object detector cascades is considered. Two main challenges are identified: optimization of the cascade configuration and optimization of individual cascade stages, so as to achieve the best tradeoff between classification accuracy and speed, under a detection rate constraint. Two novel boosting algorithms are proposed to address these problems. The first, RCBoost, formulates boosting as a constrained optimization problem which is solved with a barrier penalty method. The constraint is the target detection rate, which is met at all iterations of the boosting process. This enables the design of embedded cascades of known configuration without extensive cross validation or heuristics. The second, ECBoost, searches over cascade configurations to achieve the optimal tradeoff between classification risk and speed. The two algorithms are combined into an overall boosting procedure, RCECBoost, which optimizes both the cascade configuration and its stages under a detection rate constraint, in a fully automated manner. Extensive experiments in face, car, pedestrian, and panda detection show that the resulting detectors achieve an accuracy versus speed tradeoff superior to those of previous methods.

  5. Modelling of an RF plasma shower

    International Nuclear Information System (INIS)

    Atanasova, M; Degrez, G; Carbone, E A D; Mihailova, D; Van der Mullen, J J A M; Benova, E

    2012-01-01

    A capacitive radiofrequency (RF) discharge at atmospheric pressure is studied by means of a time-dependent, two-dimensional fluid model. The plasma is created in a stationary argon gas flow guided through two perforated electrodes, hence resembling a shower. The inner electrode, the electrode facing the flow entrance, is powered with a frequency of 13.56 MHz, and the outer electrode is grounded. The model solves the mass balance equations for the relevant active species and the electron energy balance equation in conjunction with the Poisson equation for the field sustaining the plasma. The mass balance equations of the active species are calculated using the drift-diffusion-convection approach, thus taking the bulk velocity into account. The velocity field is calculated with the Navier-Stokes module of the Plasimo toolkit. The plasma dynamics is studied in three connected regions; the space between the electrodes, the regions before the powered electrode and the extended region behind the grounded electrode. The effect of the shower holes and the recirculation gas flow on the plasma is examined. (paper)

  6. Extensive air showers accompanied by γ-ray families with summationE/sub γ//sub ,//sub H/≥10 TeV and general extensive air showers

    International Nuclear Information System (INIS)

    Fukushima, Y.; Hamayasu, C.; Mitsumune, T.

    1989-01-01

    Extensive air showers (EAS's) accompanied by families of high-energy cascade showers were observed at Mt. Norikura (738 g cm/sup -2/). 99 families of γ-ray- and hadron-origin showers with total energies summationE/sub γ//sub ,//sub H/≥10 TeV were obtained. The success rate of the combination between families and EAS's reaches to almost 90% (87 events). The families are associated with young EAS's, with mean age parameter s∼0.7, whose sizes distribute widely over three orders of magnitude up to 10 8 . The size spectrum of the family-associated EAS's coincides with the general EAS's in the size region above 5 x 10 6 but the former drops rapidly from the latter below this critical size. From the absolute intensity of summationE/sub γ//sub ,//sub H/ spectrum the proton fraction in the primary cosmic rays is deduced to be (14 +- 5)%, with an error of one standard deviation, in the primary energies (5 x 10/sup 14/)--10/sup 16/ eV, in comparison with a Monte Carlo simulation assuming an adequate interaction model. This agrees with the result obtained by the work with other mountain data and is also compatible with the result inferred from the size spectrum gap between the family-associated EAS's and the general EAS's in the region below the critical size

  7. What do we learn about hadronic interactions at ultrahigh energies from extensive air shower observations?

    International Nuclear Information System (INIS)

    Rebel, H.

    2002-01-01

    The interpretation of extensive air shower (EAS) observations needs a sufficiently accurate knowledge of the interactions driving the cascade development in the atmosphere. While the electromagnetic and weak interaction parts do not provide principal problems, the hadronic interaction is a subject of uncertainties and debates, especially in the ultrahigh energy region extending the energy limits of man made accelerators and experimental knowledge from collider experiments. Since the EAS development is dominantly governed by soft processes, which are presently not accessible to a perturbative QCD treatment, one has to rely on QCD inspired phenomenological interaction models, in particular on string-models based on the Gribov-Regge theory like QGSJET, VENUS and SYBILL. Recent results of the EAS experiments KASCADE are scrutinized in terms of such models used as generators in the Monte Carlo EAS simulation code CORSIKA. (author)

  8. What tell us extensive air shower observations about hadronic interactions at ultrahigh energies?

    International Nuclear Information System (INIS)

    Rebel, H.

    2000-01-01

    The interpretation of extensive air shower (EAS) observations needs a sufficiently accurate knowledge of the interactions driving the cascade development in the atmosphere. While the electromagnetic and weak interaction parts do not provide principal problems, the hadronic interaction is a subject of uncertainties and debates, especially in the ultrahigh energy region extending the energy limits of man made accelerators and experimental knowledge from collider experiments. Since the EAS development is dominantly governed by soft processes, which are presently not accessible to a perturbative QCD treatment, one has to rely on QCD inspired phenomenological interaction models, in particular on string-models based on the Gribow-Regge theory like QGSJET, VENUS and SYBILL. Recent results of the EAS experiments KASCADE are scrutinized in terms of such models used as generators in the Monte Carlo EAS simulation code CORSIKA. (orig.)

  9. Observation and analysis of cosmic electromagnetic cascades detected in lead photoemulsion chamber of the Brazil-Japan cooperation, exposed in Monte Chacaltaya, Bolivia (altitude 5200m, air pressure 550 gr.cm-2)

    International Nuclear Information System (INIS)

    Bastos, C.A.

    1971-04-01

    The cosmic gamma radiations in the photoemulsion chamber for Brazil-Japan Cooperation are studied. These radiations reproduces the electromagnetic component of extensive air showers at the begining of its development through the atmosphere. The gamma radiations, which is 0 Π meson decay products emitted in nuclear interaction, are detected by electromagnetic cascades which are developed when they reach the photoemulsion chamber. Cosmic gamma radiations is a set of parallel electromagnetic cascades proceeding from nuclear interactions. The information about high energy nuclear interactions making possible to study the structure of extensive air showers at the beginning of its development and multiple meson production are obtained. (M.C.K.) [pt

  10. Cascade Organic Solar Cells

    KAUST Repository

    Schlenker, Cody W.

    2011-09-27

    We demonstrate planar organic solar cells consisting of a series of complementary donor materials with cascading exciton energies, incorporated in the following structure: glass/indium-tin-oxide/donor cascade/C 60/bathocuproine/Al. Using a tetracene layer grown in a descending energy cascade on 5,6-diphenyl-tetracene and capped with 5,6,11,12-tetraphenyl- tetracene, where the accessibility of the π-system in each material is expected to influence the rate of parasitic carrier leakage and charge recombination at the donor/acceptor interface, we observe an increase in open circuit voltage (Voc) of approximately 40% (corresponding to a change of +200 mV) compared to that of a single tetracene donor. Little change is observed in other parameters such as fill factor and short circuit current density (FF = 0.50 ± 0.02 and Jsc = 2.55 ± 0.23 mA/cm2) compared to those of the control tetracene-C60 solar cells (FF = 0.54 ± 0.02 and Jsc = 2.86 ± 0.23 mA/cm2). We demonstrate that this cascade architecture is effective in reducing losses due to polaron pair recombination at donor-acceptor interfaces, while enhancing spectral coverage, resulting in a substantial increase in the power conversion efficiency for cascade organic photovoltaic cells compared to tetracene and pentacene based devices with a single donor layer. © 2011 American Chemical Society.

  11. CAMS newly detected meteor showers and the sporadic background

    Science.gov (United States)

    Jenniskens, P.; Nénon, Q.; Gural, P. S.; Albers, J.; Haberman, B.; Johnson, B.; Morales, R.; Grigsby, B. J.; Samuels, D.; Johannink, C.

    2016-03-01

    The Cameras for Allsky Meteor Surveillance (CAMS) video-based meteoroid orbit survey adds 60 newly identified showers to the IAU Working List of Meteor Showers (numbers 427, 445-446, 506-507, and part of 643-750). 28 of these are also detected in the independent SonotaCo survey. In total, 230 meteor showers and shower components are identified in CAMS data, 177 of which are detected in at least two independent surveys. From the power-law size frequency distribution of detected showers, we extrapolate that 36% of all CAMS-observed meteors originated from ∼700 showers above the N = 1 per 110,000 shower limit. 71% of mass falling to Earth from streams arrives on Jupiter-family type orbits. The transient Geminids account for another 15%. All meteoroids not assigned to streams form a sporadic background with highest detected numbers from the apex source, but with 98% of mass falling in from the antihelion source. Even at large ∼7-mm sizes, a Poynting-Robertson drag evolved population is detected, which implies that the Grün et al. collisional lifetimes at these sizes are underestimated by about a factor of 10. While these large grains survive collisions, many fade on a 104-y timescale, possibly because they disintegrate into smaller particles by processes other than collisions, leaving a more resilient population to evolve.

  12. COMET SHOWERS ARE NOT INDUCED BY INTERSTELLAR CLOUDS

    Energy Technology Data Exchange (ETDEWEB)

    Morris, D.E.

    1985-11-01

    Encounters with interstellar clouds (IC) have been proposed by Rampino and Stothers as a cause of quasi-periodic intense comet showers leading to earth impacts, in order to explain the periodicity in marine mass extinctions found by Raup and Sepkoski. The model was described further, criticized and defended. The debate has centered on the question of whether the scale height of the clouds is small enough (in comparison to the amplitude of the oscillation of the solar system about the plane of the Galaxy) to produce a modulation in the rate of encounters. We wish to point out another serious, we believe fatal, defect in this model - the tidal fields of ICs are not strong enough to produce intense comet showers leading to earth impacts by bringing comets of the postulated inner Oort cloud into earth crossing orbits, except possibly during very rare encounters with very dense clouds. We will show that encounters with abundant clouds of low density cannot produce comet showers; cloud density N > 10{sup 3} atoms cm{sup -3} is needed to produce an intense comet shower leading to earth impacts. Furthermore, the tidal field of a dense cloud during a distant encounter is too weak to produce such showers. As a consequence, comet showers induced by ICs will be far less frequent than showers caused by passing stars. This conclusion is independent of assumptions about the radial distribution of comets in the inner Oort cloud.

  13. Parton showers in a phenomenological context

    International Nuclear Information System (INIS)

    Bengtsson, M.

    1987-08-01

    Models for generating multiple parton final states, based on the Altarelli-Parisi equations, are presented. Algorithms are described for applications in e + e - physics, leptoproduction and hadron physics. The two latter cases are somewhat special since composite objects are present in the initial state. Constraints from structure function evolution are properly taken into account. The scheme in leptoproduction is made selfconsistent in the sense that parton shower evolution does not affect the measurable structure functions. The scheme developed in e + e - allows for a number of different features which are not given directly in this approach, i.e. matching onto matrix elements, coherence effects, argument in α s , implementation of kinematics etc. These options are systematically studied, using Lund string fragmentation for hadronization, and compared with experimental data. A note on α s determinations in hadron-hadron collisions is also included. (author)

  14. Transient digitizer for fast air shower events

    International Nuclear Information System (INIS)

    Wild, N.R.; Clay, R.W.

    1985-01-01

    Air shower structures are often measured on time scales of a few nanoseconds. Longitudinal disk structure near the core is of the order of meters in dimension, air Cerenkov pulses have full widths at half maximum of the order of tens of nanoseconds, and fast timing over typical arrays is usually measured to nanosecond accuracy. Oscilloscopes can be used but have very limited dynamic range and are expensive if measurements down to a few nanoseconds are to be made. For the fast Cerenkov work, an instrument with better dynamic range than an oscilloscope and with a time resolution sufficient to allow measurements limited only by system risetime of a few nanoseconds is needed. A 16/32 channel, 8 bit, fast transient digitizer was designed and built which runs at sample intervals down to approx. 1 nanosecond per channel

  15. Satellite observation of cosmic ray air showers

    International Nuclear Information System (INIS)

    Benson, Robert; Linsley, John

    1981-01-01

    The arrival trajectories of cosmic rays with energies greater than 10 19 eV afford the possibility of being traced backwards for distances comparable to the size of the Galaxy. They provide a means of testing models of the Galactic magnetic field as well as models of the origin of extra-Galactic cosmic rays. The large air showers produced by such cosmic rays can be observed by means of the atmospheric scintillation light they produce. It is shown here that a satellite-based system consisting of a single large mirror with an array of photon sensors at its focus would have outstanding advantages for the study of the highest energy cosmic rays

  16. Monte Carlo modeling and meteor showers

    International Nuclear Information System (INIS)

    Kulikova, N.V.

    1987-01-01

    Prediction of short lived increases in the cosmic dust influx, the concentration in lower thermosphere of atoms and ions of meteor origin and the determination of the frequency of micrometeor impacts on spacecraft are all of scientific and practical interest and all require adequate models of meteor showers at an early stage of their existence. A Monte Carlo model of meteor matter ejection from a parent body at any point of space was worked out by other researchers. This scheme is described. According to the scheme, the formation of ten well known meteor streams was simulated and the possibility of genetic affinity of each of them with the most probable parent comet was analyzed. Some of the results are presented

  17. Air Shower Development and Hadron Production at Very Forward Region

    Science.gov (United States)

    Sakurai, Nobuyuki

    Whereas muon in extensive air shower is an observable sensitive to the primary composition and to the hadron interaction properties, the discrepancy between measured and estimated values has not been solved. Using the new data of forward hadron from an accelerator experiment, a hadron interaction model (QGSJET II-04) is modified. Air shower simulation with the modified interaction model produces more muons. The increased muons concentrate around the shower core and the number density of secondary particle far from core does not change much.

  18. Estimation of Shower Parameters in Wavefront Sampling Technique

    OpenAIRE

    Chitnis, V. R.; Bhat, P. N.

    2001-01-01

    Wavefront sampling experiments record arrival times of \\v{C}erenkov photons with high precision at various locations in \\v{C}erenkov pool using a distributed array of telescopes. It was shown earlier that this photon front can be fitted with a spherical surface traveling at a speed of light and originating from a single point on the shower axis. Radius of curvature of the spherical shower front ($R$) is approximately equal to the height of shower maximum from observation level. For a given pr...

  19. The muon content of gamma-ray showers

    Science.gov (United States)

    Edwards, P. G.; Protheroe, R. J.

    1985-01-01

    The result of a calculation of the expected number of muons in gamma ray initiated and cosmic ray initiated air showers using a realistic model of hadronic collisions in an effort to understand the available experimental results and to assess the feasibility of using the muon content of showers as a veto to reject cosmic ray initiated showers in ultra-high energy gamma ray astronomy are reported. The possibility of observing very-high energy gamma-ray sources by detecting narrow angle anisotropies in the high energy muon background radiation are considered.

  20. The 2017 Meteor Shower Activity Forecast for Earth Orbit

    Science.gov (United States)

    Moorhead, Althea; Cooke, Bill; Moser, Danielle

    2017-01-01

    Most meteor showers will display typical activity levels in 2017. Perseid activity is expected to be higher than normal but less than in 2016; rates may reach 80% of the peak ZHR in 2016. Despite this enhancement, the Perseids rank 4th in flux for 0.04-cm-equivalent meteoroids: the Geminids (GEM), Daytime Arietids (ARI), and Southern delta Aquariids (SDA) all produce higher fluxes. Aside from heightened Perseid activity, the 2017 forecast includes a number of changes. In 2016, the Meteoroid Environment Office used 14 years of shower flux data to revisit the activity profiles of meteor showers included in the annual forecast. Both the list of showers and the shape of certain major showers have been revised. The names and three-letter shower codes were updated to match those in the International Astronomical Union (IAU) Meteor Data Center, and a number of defunct or insignificant showers were removed. The most significant of these changes are the increased durations of the Daytime Arietid (ARI) and Geminid (GEM) meteor showers. This document is designed to supplement spacecraft risk assessments that incorporate an annual averaged meteor shower flux (as is the case with all NASA meteor models). Results are presented relative to this baseline and are weighted to a constant kinetic energy. Two showers - the Daytime Arietids (ARI) and the Geminids (GEM) - attain flux levels approaching that of the baseline meteoroid environment for 0.1-cm-equivalent meteoroids. This size is the threshold for structural damage. These two showers, along with the Quadrantids (QUA) and Perseids (PER), exceed the baseline flux for 0.3-cm-equivalent particles, which is near the limit for pressure vessel penetration. Please note, however, that meteor shower fluxes drop dramatically with increasing particle size. As an example, the Arietids contribute a flux of about 5x10(exp -6) meteoroids m(exp -2) hr-1 in the 0.04-cm-equivalent range, but only 1x10(exp -8) meteoroids m(sub -2) hr-1 for the 0

  1. Modelling of radio emission from cosmic ray air showers

    Science.gov (United States)

    Ludwig, Marianne

    2011-06-01

    Cosmic rays entering the Earth's atmosphere induce extensive air showers consisting of up to billions of secondary particles. Among them, a multitude of electrons and positrons are generated. These get deflected in the Earth's magnetic field, creating time-varying transverse currents. Thereby, the air shower emits coherent radiation in the MHz frequency range measured by radio antenna arrays on the ground such as LOPES at the KIT. This detection method provides a possibility to study cosmic rays with energies above 1017 eV. At this time, the radio technique undergoes the change from prototype experiments to large scale application. Thus, a detailed understanding of the radio emission process is needed more than ever. Before starting this work, different models made conflicting predictions on the pulse shape and the amplitude of the radio signal. It turned out that a radiation component caused by the variation of the number of charged particles within the air shower was missed in several models. The Monte Carlo code REAS2 superposing the radiation of the individual air shower electrons and positrons was one of those. At this time, it was not known how to take the missing component into account. For REAS3, we developed and implemented the endpoint formalism, a universal approach, to calculate the radiation from each single particle. For the first time, we achieve a good agreement between REAS3 and MGMR, an independent and completely different simulation approach. In contrast to REAS3, MGMR is based on a macroscopic approach and on parametrisations of the air shower. We studied the differences in the underlying air shower models to explain the remaining deviations. For comparisons with LOPES data, we developed a new method which allows "top-down" simulations of air showers. From this, we developed an air shower selection criterion based on the number of muons measured with KASCADE to take shower-to-shower fluctuations for a single event analysis into account. With

  2. Search for bursts of extensive air showers arriving successively over a short period

    OpenAIRE

    Tsuji, Katsufumi; Kitamura, Takashi; Konishi, Takeharu; Chikawa, Michiyuki

    1993-01-01

    [Abstract] Extensive air showers have been observed with eight plastic scintillation counters since June 1991. The time structure of the air shower events is confirmed to follow a Poisson distribution. To search for air shower bursts, we have analyzed arrival times of air showers with an adaptive cluster method and selected five burst candidates. A cluster of four arrival times within 3.87 s was the best candidate. We also suggest that air shower rate increased noticeably at 22 hours sidereal...

  3. Nitrogen fluorescence in air for observing extensive air showers

    CERN Document Server

    Keilhauer, B; Fraga, M; Matthews, J; Sakaki, N; Tameda, Y; Tsunesada, Y; Ulrich, A

    2012-01-01

    Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over tenth of kilometers. This measurement technique is well-established since it is exploited for many decades by several cosmic ray experiments. However, a fundamental aspect of the air shower analyses is the description of the fluorescence emission in dependence on varying atmospheric conditions. Different fluorescence yields affect directly the energy scaling of air shower reconstruction. In order to explore the various details of the nitrogen fluorescence emission in air, a few experimental groups have been performing dedicated measurements over the last decade. Most of the measurements are now finished. These experimental groups have been discussing their techniques and results in a series of \\emph{Air Fluorescence Workshops} commenced in 2002. At the 8$^{\\rm{th}}$ Air Fluoresc...

  4. Multiplicity distributions of shower particles and target fragments in ...

    Indian Academy of Sciences (India)

    Em (emul- sion) collisions at 3 A GeV/c are experimentally studied. In the framework of the multisource thermal model, the multicomponent Erlang distribution is used to describe the experimental mul- tiplicity distributions of shower particles, ...

  5. Review of Model Predictions for Extensive Air Showers

    Science.gov (United States)

    Pierog, Tanguy

    In detailed air shower simulations, the uncertainty in the prediction of shower observable for different primary particles and energies is currently dominated by differences between hadronic interaction models. With the results of the first run of the LHC, the difference between post-LHC model predictions has been reduced at the same level as experimental uncertainties of cosmic ray experiments. At the same time new types of air shower observables, like the muon production depth, have been measured, adding new constraints on hadronic models. Currently no model is able to reproduce consistently all mass composition measurements possible with the Pierre Auger Observatory for instance. We review the current model predictions for various particle production observables and their link with air shower observables and discuss the future possible improvements.

  6. Multiplicity distributions of shower particles and target fragments in 7 ...

    Indian Academy of Sciences (India)

    emulsion) collisions at 3 A GeV/c are experimentally studied. In the framework of the multisource thermal model, the multicomponent Erlang distribution is used to describe the experimental multiplicity distributions of shower particles, grey fragments ...

  7. A confidence index for forecasting of meteor showers

    Science.gov (United States)

    Vaubaillon, Jeremie

    2017-09-01

    The forecasting of meteor showers is currently very good at predicting the timing of meteor outbursts, but still needs further work regarding the level of a given shower. Moreover, uncertainties are rarely provided, leaving the end user (scientist, space agency or the public) with no way to evaluate how much the prediction is trustworthy. A confidence index for the forecasting of meteor showers is presented. It allows one to better understand how a specific forecasting has been performed. In particular, it underlines the role of our current knowledge of the parent body, its past orbit and past activity. The role of close encounters with planets for the time period considered is quantified as well. This confidence index is a first step towards better constrained forecasting of future meteor showers.

  8. Systematic improvement of parton showers with effective theory

    International Nuclear Information System (INIS)

    Baumgart, Matthew; Marcantonini, Claudio; Stewart, Iain W.

    2011-01-01

    We carry out a systematic classification and computation of next-to-leading order kinematic power corrections to the fully differential cross section in the parton shower. To do this we devise a map between ingredients in a parton shower and operators in a traditional effective field theory framework using a chain of soft-collinear effective theories. Our approach overcomes several difficulties including avoiding double counting and distinguishing approximations that are coordinate choices from true power corrections. Branching corrections can be classified as hard-scattering, that occur near the top of the shower, and jet-structure, that can occur at any point inside it. Hard-scattering corrections include matrix elements with additional hard partons, as well as power suppressed contributions to the branching for the leading jet. Jet-structure corrections require simultaneous consideration of potential 1→2 and 1→3 branchings. The interference structure induced by collinear terms with subleading powers remains localized in the shower.

  9. Expected Increase of Activity of Eta Aquariids Meteor Shower

    Science.gov (United States)

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

    2018-04-01

    Analysis of the results of modeling disintegration of Comet 1P/Halley after its flare in 1991 has allowed us to predict an increase of the activity of the associated Eta Aquariids meteor shower in April-May 2018.

  10. A Bayesian statistical method for particle identification in shower counters

    International Nuclear Information System (INIS)

    Takashimizu, N.; Kimura, A.; Shibata, A.; Sasaki, T.

    2004-01-01

    We report an attempt on identifying particles using a Bayesian statistical method. We have developed the mathematical model and software for this purpose. We tried to identify electrons and charged pions in shower counters using this method. We designed an ideal shower counter and studied the efficiency of identification using Monte Carlo simulation based on Geant4. Without having any other information, e.g. charges of particles which are given by tracking detectors, we have achieved 95% identifications of both particles

  11. Multi-Year CMOR Observations of the Geminid Meteor Shower

    Science.gov (United States)

    Webster, A. R.; Jones, J.

    2011-01-01

    The three-station Canadian Meteor Orbit Radar (CMOR) is used here to examine the Geminid meteor shower with respect to variation in the stream properties including the flux and orbital elements over the period of activity in each of the consecutive years 2005 2008 and the variability from year to year. Attention is given to the appropriate choice and use of the D-criterion in the separating the shower meteors from the sporadic background.

  12. The neutron 'thunder' accompanying the extensive air shower

    OpenAIRE

    Erlykin, A. D.

    2007-01-01

    Simulations show that neutrons are the most abundant component among extensive air shower hadrons. However, multiple neutrons which appear with long delays in neutron monitors nearby the EAS core ('neutron thunder') are mostly not the neutrons of the shower, but have a secondary origin. The bulk of them is produced by high energy EAS hadrons hitting the monitors. The delays are due to the termalization and diffusion of neutrons in the moderator and reflector of the monitor accompanied by the ...

  13. Reweighting QCD matrix-element and parton-shower calculations

    OpenAIRE

    Bothmann, Enrico; Schönherr, Marek; Schumann, Steffen

    2016-01-01

    We present the implementation and validation of the techniques used to efficiently evaluate parametric and perturbative theoretical uncertainties in matrix-element plus parton-shower simulations within the Sherpa event-generator framework. By tracing the full αs and PDF dependences, including the parton-shower component, as well as the fixed-order scale uncertainties, we compute variational event weights on-the-fly, thereby greatly reducing the computational costs to obtain theoretical-uncert...

  14. Production of high-energy muons in gamma showers

    International Nuclear Information System (INIS)

    Stanev, T.; Vankov, C.P.

    1985-01-01

    We have calculated the number of high-energy muons in gamma showers generated by photoproduction and by muon pair creation. The prompt muons have flatter energy spectrum than the muons, which come from photoproduction and contribute significant fraction of the total rates for Esub(μ)>=1 TeV. The total rate of high-energy muons in gamma showers is, however, very low. (orig.)

  15. Reweighting QCD matrix-element and parton-shower calculations

    Energy Technology Data Exchange (ETDEWEB)

    Bothmann, Enrico; Schumann, Steffen [Universitaet Goettingen, II. Physikalisches Institut, Goettingen (Germany); Schoenherr, Marek [Universitaet Zuerich, Physik-Institut, Zuerich (Switzerland)

    2016-11-15

    We present the implementation and validation of the techniques used to efficiently evaluate parametric and perturbative theoretical uncertainties in matrix-element plus parton-shower simulations within the Sherpa event-generator framework. By tracing the full α{sub s} and PDF dependences, including the parton-shower component, as well as the fixed-order scale uncertainties, we compute variational event weights on-the-fly, thereby greatly reducing the computational costs to obtain theoretical-uncertainty estimates. (orig.)

  16. An analytic parton shower. Algorithms, implementation and validation

    Energy Technology Data Exchange (ETDEWEB)

    Schmidt, Sebastian

    2012-06-15

    The realistic simulation of particle collisions is an indispensable tool to interpret the data measured at high-energy colliders, for example the now running Large Hadron Collider at CERN. These collisions at these colliders are usually simulated in the form of exclusive events. This thesis focuses on the perturbative QCD part involved in the simulation of these events, particularly parton showers and the consistent combination of parton showers and matrix elements. We present an existing parton shower algorithm for emissions off final state partons along with some major improvements. Moreover, we present a new parton shower algorithm for emissions off incoming partons. The aim of these particular algorithms, called analytic parton shower algorithms, is to be able to calculate the probabilities for branchings and for whole events after the event has been generated. This allows a reweighting procedure to be applied after the events have been simulated. We show a detailed description of the algorithms, their implementation and the interfaces to the event generator WHIZARD. Moreover we discuss the implementation of a MLM-type matching procedure and an interface to the shower and hadronization routines from PYTHIA. Finally, we compare several predictions by our implementation to experimental measurements at LEP, Tevatron and LHC, as well as to predictions obtained using PYTHIA. (orig.)

  17. An analytic parton shower. Algorithms, implementation and validation

    International Nuclear Information System (INIS)

    Schmidt, Sebastian

    2012-06-01

    The realistic simulation of particle collisions is an indispensable tool to interpret the data measured at high-energy colliders, for example the now running Large Hadron Collider at CERN. These collisions at these colliders are usually simulated in the form of exclusive events. This thesis focuses on the perturbative QCD part involved in the simulation of these events, particularly parton showers and the consistent combination of parton showers and matrix elements. We present an existing parton shower algorithm for emissions off final state partons along with some major improvements. Moreover, we present a new parton shower algorithm for emissions off incoming partons. The aim of these particular algorithms, called analytic parton shower algorithms, is to be able to calculate the probabilities for branchings and for whole events after the event has been generated. This allows a reweighting procedure to be applied after the events have been simulated. We show a detailed description of the algorithms, their implementation and the interfaces to the event generator WHIZARD. Moreover we discuss the implementation of a MLM-type matching procedure and an interface to the shower and hadronization routines from PYTHIA. Finally, we compare several predictions by our implementation to experimental measurements at LEP, Tevatron and LHC, as well as to predictions obtained using PYTHIA. (orig.)

  18. Prediction of human thermophysiological responses during shower bathing.

    Science.gov (United States)

    Munir, Abdul; Takada, Satoru; Matsushita, Takayuki; Kubo, Hiroko

    2010-03-01

    This study develops a model to predict the thermophysiological response of the human body during shower bathing. Despite the needs for the quantitative evaluation of human body response during bathing for thermal comfort and safety, the complicated mechanisms of heat transfer at the skin surface, especially during shower bathing, have disturbed the development of adequate models. In this study, an initial modeling approach is proposed by developing a simple heat transfer model at the skin surface during shower bathing applied to Stolwijk's human thermal model. The main feature of the model is the division of the skin surface into three parts: a dry part, a wet part without water flow, and a wet part with water flow. The area ratio of each part is decided by a simple formula developed from a geometrical approach based on the shape of the Stolwijk's human thermal model. At the same time, the convective heat transfer coefficient between the skin and the flowing water is determined experimentally. The proposed model is validated by a comparison with the results of human subject experiments under controlled and free shower conditions. The model predicts the mean skin temperature during shower fairly well both for controlled and free shower bathing styles.

  19. The radio emission pattern of air showers as measured with LOFAR—a tool for the reconstruction of the energy and the shower maximum

    NARCIS (Netherlands)

    Nelles, A.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, Gia

    2015-01-01

    The pattern of the radio emission of air showers is finely sampled with the Low-Frequency ARray (LOFAR). A set of 382 measured air showers is used to test a fast, analytic parameterization of the distribution of pulse powers. Using this parameterization we are able to reconstruct the shower axis and

  20. The Working Group on Meteor Showers Nomenclature: a History, Current Status and a Call for Contributions

    Science.gov (United States)

    Jopek, T. J.; Jenniskens, P. M.

    2011-01-01

    During the IAU General Assembly in Rio de Janeiro in 2009, the members of Commission 22 established the Working Group on Meteor Shower Nomenclature, from what was formerly the Task Group on Meteor Shower Nomenclature. The Task Group had completed its mission to propose a first list of established meteor showers that could receive officially names. At the business meeting of Commission 22 the list of 64 established showers was approved and consequently officially accepted by the IAU. A two-step process is adopted for showers to receive an official name from the IAU: i) before publication, all new showers discussed in the literature are first added to the Working List of Meteor Showers, thereby receiving a unique name, IAU number and three-letter code; ii) all showers which come up to the verification criterion are selected for inclusion in the List of Established Meteor Showers, before being officially named at the next IAU General Assembly.

  1. Performance characteristics of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan; Li Dandan

    2007-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In contrast to conventional cooling towers, the cooling tower analyzed in this study is void of fill. By means of efficient atomization nozzles, a shower cooling tower (SCT) is possible to be applied in industry, which, in terms of water cooling, energy saving and equipment investing, is better than conventional packed cooling towers. However, no systematic thermodynamic numerical method could be found in the literature up to now. Based on the kinetic model and mass and heat transfer model, this paper has developed a one dimensional model for studying the motional process and evaporative cooling process occurring at the water droplet level in the SCT. The finite difference approach is used for three motional processes to obtain relative parameters in each different stage, and the possibility of the droplets being entrained outside the tower is fully analyzed. The accuracy of this model is checked by practical operational results from a full scale prototype in real conditions, and some exclusive factors that affect the cooling characteristics for the SCT are analyzed in detail. This study provides the theoretical foundation for practical application of the SCT in industry

  2. Biofilms on Hospital Shower Hoses: Characterization and ...

    Science.gov (United States)

    Although the source of drinking water used in hospitals is commonly, biofilms on water pipelines are refuge to bacteria that survive different disinfection strategies. Drinking water (DW) biofilms are well known to harbor opportunistic pathogens, however, these biofilm communities remain poorly characterized by culture-independent approaches that circumvent the limitations of conventional monitoring efforts. Hence, the frequency of pathogens in DW biofilms and how biofilm members withstand high doses of disinfectants and/or chlorine residuals in the water supply remain speculative, but directly impact public health. The aim of this study was to characterize the composition of microbial communities growing on five hospital shower hoses using both culture-dependent and culture-independent techniques. Two different sequence-based methods were used to characterize the bacterial fractions: 16S rRNA gene sequencing of bacterial cultures and next generation sequencing of metagenomes. Based on the metagenomic data, we found that Mycobacterium-like species was the abundant bacterial taxa that overlapped among the five samples. We also recovered the draft genome of a novel Mycobacterium species, closely related to opportunistic pathogenic nontuberculous mycobacteria, M. rhodesiae and M. tusciae, in addition to other, less abundant species. In contrast, the cultured fraction was mostly affiliated to Proteobacteria, such as members of the Sphingomonas, Blastomonas and Porph

  3. Nitrogen fluorescence in air for observing extensive air showers

    Directory of Open Access Journals (Sweden)

    Tsunesada Y.

    2013-06-01

    Full Text Available Extensive air showers initiate the fluorescence emissions from nitrogen molecules in air. The UV-light is emitted isotropically and can be used for observing the longitudinal development of extensive air showers in the atmosphere over tenth of kilometers. This measurement technique is well-established since it is exploited for many decades by several cosmic ray experiments. However, a fundamental aspect of the air shower analyses is the description of the fluorescence emission in dependence on varying atmospheric conditions. Different fluorescence yields affect directly the energy scaling of air shower reconstruction. In order to explore the various details of the nitrogen fluorescence emission in air, a few experimental groups have been performing dedicated measurements over the last decade. Most of the measurements are now finished. These experimental groups have been discussing their techniques and results in a series of Air Fluorescence Workshops commenced in 2002. At the 8th Air Fluorescence Workshop 2011, it was suggested to develop a common way of describing the nitrogen fluorescence for application to air shower observations. Here, first analyses for a common treatment of the major dependences of the emission procedure are presented. Aspects like the contributions at different wavelengths, the dependence on pressure as it is decreasing with increasing altitude in the atmosphere, the temperature dependence, in particular that of the collisional cross sections between molecules involved, and the collisional de-excitation by water vapor are discussed.

  4. Catalogue of Meteor Showers and Storms in Korean History

    Directory of Open Access Journals (Sweden)

    Sang-Hyeon Ahn

    2004-03-01

    Full Text Available We present a more complete and accurate catalogue of astronomical records for meteor showers and meteor storms appeared in primary official Korean history books, such as Samguk-sagi, Koryo-sa, Seungjeongwon-ilgi, and Choson-Wangjo-Sillok. So far the catalogue made by Imoto and Hasegawa in 1958 has been widely used in the international astronomical society. The catalogue is based on a report by Sekiguchi in 1917 that is mainly based on secondary history books. We observed that the catalogue has a number of errors in either dates or sources of the records. We have thoroughly checked the primary official history books, instead of the secondary ones, in order to make a corrected and extended catalogue. The catalogue contains 25 records of meteor storms, four records of intense meteor-showers, and five records of usual showers in Korean history. We also find that some of those records seem to correspond to some presently active meteor showers such as the Leonids, the Perseids, and the ¥ç-Aquarids-Orionids pair. However, a large number of those records do not correspond to such present showers. This catalogue we obtained can be useful for various astrophysical studies in the future.

  5. The activity of autumn meteor showers in 2006-2008

    Science.gov (United States)

    Kartashova, Anna

    2015-03-01

    The purpose of meteor observations in INASAN is the study of meteor showers, as the elements of the migrant substance of the Solar System, and estimation of risk of hazardous collisions of spacecrafts with the particles of streams. Therefore we need to analyze the meteor events with brightness of up to 8 m, which stay in meteoroid streams for a long time and can be a hazardous for the spacecraft. The results of our single station TV observations of autumn meteor showers for the period from 2006 to 2008 are presented. The high-sensitive hybrid camera (the system with coupled of the Image Intensifier) FAVOR with limiting magnitude for meteors about 9m. . .10m in the field of view 20 × 18 was used for observations. In 2006-2008 from October to November more than 3 thousand of meteors were detected, 65% from them have the brightness from 6m to 9m. The identification with autumn meteor showers (Orionids, Taurids, Draconids, Leonids) was carried out. In order to estimate the density of the influx of meteor matter to the Earth for these meteor showers the Index of meteor activity (IMA) was calculated. The IMA distribution for the period 2006 - 2008 is given. The distributions of autumn meteor showers (the meteors with brightness of up to 8 m) by stellar magnitude from 2006 to 2008 are also presented.

  6. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...... by the media, with harmful effects on democracy....

  7. Cascading Corruption News

    DEFF Research Database (Denmark)

    Damgaard, Mads

    2018-01-01

    Through a content analysis of 8,800 news items and six months of front pages in three Brazilian newspapers, all dealing with corruption and political transgression, this article documents the remarkable skew of media attention to corruption scandals. The bias is examined as an information...... phenomenon, arising from systemic and commercial factors of Brazil’s news media: An information cascade of news on corruption formed, destabilizing the governing coalition and legitimizing the impeachment process of Dilma Rousseff. As this process gained momentum, questions of accountability were disregarded...

  8. Large high altitude air shower observatory (LHAASO) project

    International Nuclear Information System (INIS)

    He Huihai

    2010-01-01

    The Large High Altitude Air Shower Observatory (LHAASO) project focuses mainly on the study of 40 GeV-1 PeV gamma ray astronomy and 10 TeV-1 EeV cosmic ray physics. It consists of a 1 km 2 extensive air shower array with 40 000 m 2 muon detectors, 90,000m 2 water Cerenkov detector array, 5 000 m 2 shower core detector array and an air Cerenkov/fluorescence telescope array. Prototype detectors are designed with some of them already in operation. A prototype array of 1% size of LHAASO will be built at the Yangbajing Cosmic Ray Observatory and used to coincidently measure cosmic rays with the ARGO-YBJ experiment. (authors)

  9. Search for acoustic effects from extensive atmospheric showers in Baikal

    International Nuclear Information System (INIS)

    Lyashuk, V.I.; Novikov, E.G.

    2006-01-01

    The search for acoustic effects from showers by means of hydrophones was realized in a trigger scheme of recording sound files when atmospheric showers were detected by the scintillation installation. A method of peaks and noncoincidences was proposed to search for weak sound sources. The algorithm of the method is amplitude independent. Processing of a great body of data (obtained for different geometries, different noise background during three expeditions to Baikal) allows one to indicate the closely analogous phenomena at the instant of time of expected sound signals from showers. In spite of their low power, the effects appear in the different hydrophones and have similar time distributions, which points to the detection of the acoustic effects

  10. System to determine the incoming direction of air showers

    International Nuclear Information System (INIS)

    Nagano, Motohiko

    1984-01-01

    The incoming direction of air showers is determined by the measurement of the time difference of events observed at three or more observation points. The errors due to the measurement of time difference come from the thickness of shower plane, the fluctuation of the drift time of electrons in a photomultiplier, the walk effect of a trigger circuit, and the errors due to the recording system. One must take care of these effects of the detection system. The circuits used for the measurement of time difference are of time-stretcher type, vernier counter type, and direct time difference counting type. The accuracy of the determination of incoming direction depends on shower size. The practical standard deviation was about a few degree. (Kato, T.)

  11. Effects of subleading color in a parton shower

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2014-12-01

    Parton shower Monte Carlo event generators in which the shower evolves from hard splittings to soft splittings generally use the leading color (LC) approximation, which is the leading term in an expansion in powers of 1/N c 2 , where N c =3 is the number of colors. In the parton shower event generator DEDUCTOR, we have introduced a more general approximation, the LC+ approximation, that includes some of the color suppressed contributions. In this paper, we explore the differences in results between the LC approximation and the LC+ approximation. Numerical comparisons suggest that, for simple observables, the LC approximation is quite accurate. We also find evidence that for gap-between-jets cross sections neither the LC approximation nor the LC+ approximation is adequate.

  12. Delayed hadrons in air showers observed in Chacaltaya

    International Nuclear Information System (INIS)

    Kakimoto, Fumio

    1984-01-01

    Bolivian Air Shower Joint Experiment group has studied high energy interaction by measuring the aspect of vertical growth of air showers of 10 16 eV or more at Mt. Chacaltaya Space Physics Observatory at 5200 m above sea level and atmospheric depth of 550 g/cm 2 . The aspect of vertical growth of electrons from about 100 g/cm 2 to about 400 g/cm 2 of atmospheric depth obtained by the measured results of the time of arrival distribution of air Cherenkov radiation at Mt. Chacaltaya agreed with the one predicted from the enhanced 1/2 power of E model. Since the vertical growth of electrons and muons in about 10 17 eV air showers from the atmospheric apex was difficult to give the unified explanation with known interaction models, the University of Tokyo group has proposed a two-component model for air shower growth. If this second component is formed from heavy particles or heavy quantum state as parents, it should be observed as the component which arrives later in air shower. Thus, the measurement and experiment on the delayed hadrons in air showers have been started. In this paper, the experiment, analysis and results are reported. It is clear that the parent particles which caused such a phenomenon were not pions which were multiply generated by the interaction generally known. Therefore, an exact simulating calculation must be performed and compared with the experimental results to obtain the final conclusion from the measured results of this time. (Wakatsuki, Y.)

  13. The time structure of atmospheric Cerenkov light in extensive air showers

    International Nuclear Information System (INIS)

    Boehm, E.; Bosia, G.; Navarra, G.; Saavedra, O.

    1977-01-01

    The time structure of atmospheric Cherenkov light has been measured by narrow-angle detectors in extensive air showers with a time resolution of 0.15 ns. From comparison with particle density observations in the same showers it is deduced that the temporal shape is a measure of the lateral structure of the particle shower disc rather than of the longitudinal shower development. (author)

  14. Prospects for determining air shower characteristics through geosynchrotron emission arrival times

    OpenAIRE

    Lafebre, S.; Falcke, H.; Hörandel, J.; Huege, T.; Kuijpers, J.

    2010-01-01

    Using simulations of geosynchrotron radiation from extensive air showers, we present a relation between the shape of the geosynchrotron radiation front and the distance of the observer to the maximum of the air shower. By analyzing the relative arrival times of radio pulses at several radio antennas in an air shower array, this relation may be employed to estimate the depth of maximum of an extensive air shower if its impact position is known, allowing an estimate for the primary particle's s...

  15. Shower fractal dimension analysis in a highly-granular calorimeter

    CERN Document Server

    Ruan, M

    2014-01-01

    We report on an investigation of the self-similar structure of particle showers recorded at a highly-granular calorimeter. On both simulated and experimental data, a strong correlation between the number of hits and the spatial scale of the readout channels is observed, from which we define the shower fractal dimension. The measured fractal dimension turns out to be strongly dependent on particle type, which enables new approaches for particle identification. A logarithmic dependence of the particle energy on the fractal dimension is also observed.

  16. 16 CFR 1201.40 - Interpretation concerning bathtub and shower doors and enclosures.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 2 2010-01-01 2010-01-01 false Interpretation concerning bathtub and shower... Policy and Interpretation § 1201.40 Interpretation concerning bathtub and shower doors and enclosures. (a... and enclosures” and “shower door and enclosure” as they are used in the Standard in subpart A. The...

  17. What the radio signal tells about the cosmic-ray air shower

    NARCIS (Netherlands)

    Scholten, Olaf; de Vries, Krijn D.; Werner, Klaus

    2013-01-01

    The physics of radio emission from cosmic-ray induced air showers is shortly summarized. It will be shown that the radio signal at different distances from the shower axis provides complementary information on the longitudinal shower evolution, in particular the early part, and on the distribution

  18. The search for extended air showers at the Jicamarca Radio Observatory

    International Nuclear Information System (INIS)

    Wahl, D.; Chau, J.; Galindo, F.; Huaman, A.; Solano, C. J.

    2009-01-01

    This paper presents the status of the project to detect extended air showers at the Jicamarca Radio Observatory. We report on detected anomalous signals and present a toy model to estimate at what altitudes we might expect to see air shower signals. According to this model, a significant number of high altitude horizontal air showers could be observed by radar techniques.

  19. 46 CFR 108.205 - Wash spaces; toilet spaces; and shower spaces.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Wash spaces; toilet spaces; and shower spaces. 108.205...; toilet spaces; and shower spaces. (a) For the purposes of this section— (1) “Private facility” means a toilet, washing, or shower space that is accessible only from one single or double occupancy sleeping...

  20. Cosmic ray air shower characteristics in the framework of the parton-based Gribov-Regge model nexus

    International Nuclear Information System (INIS)

    Bossard, G.; Drescher, H.J.; Ostapchenko, S.; Pierog, T.; Werner, K.; Kalmykov, N.N.; Ostapchenko, S.; Pavlov, A.I.; Vishnevskaya, E.A.

    2000-08-01

    The purpose of this paper is twofold: first we want to introduce a new type of hadronic interaction model (NEXUS), which has a much more solid theoretical basis as, for example, presently used models like QGSJET and VENUS, and ensures therefore a much more reliable extrapolation towards high energies. Secondly, we want to promote an extensive air shower (EAS) calcination scheme, based on cascade equations rather than explicit Monte Carlo simulations, which is very accurate in calcination of main EAS characteristics and extremely fast concerning computing time. We employ the NEXUS model to provide the necessary data on particle production in hadron-air collisions and present the average EAS characteristics for energies 10 14 - 10 17 eV. The experimental data of the CASA-BLANKA group are analyzed in the framework of the new model. (authors)

  1. Cascade Error Projection Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.

    1995-01-01

    A detailed mathematical analysis is presented for a new learning algorithm termed cascade error projection (CEP) and a general learning frame work. This frame work can be used to obtain the cascade correlation learning algorithm by choosing a particular set of parameters.

  2. Interband cascade lasers

    International Nuclear Information System (INIS)

    Vurgaftman, I; Meyer, J R; Canedy, C L; Kim, C S; Bewley, W W; Merritt, C D; Abell, J; Weih, R; Kamp, M; Kim, M; Höfling, S

    2015-01-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron–hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3–6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm −2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT. (topical review)

  3. Interband cascade lasers

    Science.gov (United States)

    Vurgaftman, I.; Weih, R.; Kamp, M.; Meyer, J. R.; Canedy, C. L.; Kim, C. S.; Kim, M.; Bewley, W. W.; Merritt, C. D.; Abell, J.; Höfling, S.

    2015-04-01

    We review the current status of interband cascade lasers (ICLs) emitting in the midwave infrared (IR). The ICL may be considered the hybrid of a conventional diode laser that generates photons via electron-hole recombination, and an intersubband-based quantum cascade laser (QCL) that stacks multiple stages for enhanced current efficiency. Following a brief historical overview, we discuss theoretical aspects of the active region and core designs, growth by molecular beam epitaxy, and the processing of broad-area, narrow-ridge, and distributed feedback (DFB) devices. We then review the experimental performance of pulsed broad area ICLs, as well as the continuous-wave (cw) characteristics of narrow ridges having good beam quality and DFBs producing output in a single spectral mode. Because the threshold drive powers are far lower than those of QCLs throughout the λ = 3-6 µm spectral band, ICLs are increasingly viewed as the laser of choice for mid-IR laser spectroscopy applications that do not require high output power but need to be hand-portable and/or battery operated. Demonstrated ICL performance characteristics to date include threshold current densities as low as 106 A cm-2 at room temperature (RT), cw threshold drive powers as low as 29 mW at RT, maximum cw operating temperatures as high as 118 °C, maximum cw output powers exceeding 400 mW at RT, maximum cw wallplug efficiencies as high as 18% at RT, maximum cw single-mode output powers as high as 55 mW at RT, and single-mode output at λ = 5.2 µm with a cw drive power of only 138 mW at RT.

  4. Cosmic ray air showers in the knee energy region

    Indian Academy of Sciences (India)

    deviation assuming the fluctuation as Gaussian in nature. Using these fluctuated densities the selection criteria for a particular size group is imposed to check whether the shower is selected or not. The calculation is repeated many times to attain statistical significance for a particular Ne,S and z in a particular annular ring.

  5. Observation of Horizontal Air Showers with ARGO-YBJ

    Energy Technology Data Exchange (ETDEWEB)

    Panico, B., E-mail: beatrice.panico@roma2.infn.it [Dipartimento di Fisica, Universita Roma ' Tor Vergata' , Via della Ricerca Scientifica 1, Roma (Italy); INFN, Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy); Di Sciascio, G. [INFN, Sezione Roma Tor Vergata, Via della Ricerca Scientifica 1, Roma (Italy)

    2012-11-11

    A preliminary analysis of Extensive Air Showers reconstructed by ARGO-YBJ with zenith angle greater than 80 Degree-Sign is reported. The measurement of the size spectrum and of the azimuthal distribution is discussed. A description of the topology of these events is also provided.

  6. Extraction of Fronto-orbital Shower Hook through Transcranial Orbitotomy.

    Science.gov (United States)

    Elia, Maxwell D; Gunel, Murat; Servat, Juan J; Levin, Flora

    2014-06-01

    Transorbital foreign bodies threaten both the integrity of the globe and the brain. We present an unusual case of a penetrating right frontal lobe-orbital metallic shower hook. Extensive intracranial involvement necessitated transcranial orbitotomy allowing for the removal of the object without loss of the globe.

  7. Progress in air shower radio measurements : detection of distant events

    NARCIS (Netherlands)

    Bähren, L.; Buitink, S.J.; Falcke, H.D.E.; Horneffer, K.H.A.; Kuijpers, J.M.E.; Lafebre, S.J.; Nigl, A.; Petrovic, J.; Singh, K.

    2006-01-01

    Data taken during half a year of operation of 10 LOPES antennas (LOPES-10), triggered by EAS observed with KASCADE-Grande have been analysed. We report about the analysis of correlations of radio signals measured by LOPES-10 with extensive air shower events reconstructed by KASCADE-Grande, including

  8. Hadronic shower development in iron-scintillator tile calorimetry

    Czech Academy of Sciences Publication Activity Database

    Amaral, P.; Amorim, A.; Anderson, K.; Lokajíček, Miloš; Němeček, Stanislav

    2000-01-01

    Roč. 443, - (2000), s. 51-70 ISSN 0168-9002 R&D Projects: GA MPO RP-4210/69 Institutional research plan: CEZ:AV0Z1010920 Keywords : ATLAS Iron-Scintillator * hadron calorimeter * shower parametrisation * calorimetry * computer data analysis Subject RIV: BL - Plasma and Gas Discharge Physics Impact factor: 0.964, year: 2000

  9. Multiplicity distributions of shower particles and target fragments in ...

    Indian Academy of Sciences (India)

    Figure 1. Multiplicity distributions of (a) shower particles, (b) grey fragments, (c) black fragments, and (d) heavily ionized fragments produced in 3Li–Em collisions at 3 A GeV/c. The histograms and curves are our experimental data and modelling results respectively. Table 1. Parameter values and the corresponding χ2/dof ...

  10. Muon spectrum in air showers initiated by gamma rays

    Science.gov (United States)

    Stephens, S. A.; Streitmatter, R. E.

    1985-01-01

    An analytic representation for the invariant cross-section for the production of charged pions in gamma P interactions was derived by using the available cross-sections. Using this the abundance of muons in a gamma ray initiated air shower is calculated.

  11. NLO Corrections and Parton Showers in the LHC Era

    CERN Document Server

    Arnold, Ken Boris

    The Large Hadron Collider provides a challenging environment, not only for experimentalists. Precise predictions are needed in order to use its potential to full capacity. This thesis focuses on predictions including higher-order corrections in a twofold way. Both results for a pure parton level calculation and for a calculation incorporating a parton shower are presented. Higgs boson plus photon production via vector boson fusion was implemented in a fully flexible parton-level Monte-Carlo program. The results at next-to-leading order accuracy are discussed. It is found that the corrections are large in some regions of phase space. For the simulation of a parton shower matched to a next-to-leading order matrix element, a mixed-language runtime interface was established to use existing matrix elements for Higgs boson production via vector boson fusion. Results are discussed for different parton shower algorithms and matching schemes. The simulation is shown to have a substantial dependence on the shower algor...

  12. Don Quixote --- a possible parent body of a meteor shower

    Science.gov (United States)

    Rudawska, R.; Vaubaillon, J.

    2014-07-01

    This talk addresses the topic of meteoroid stream parent body in relation to meteor showers observed on the Earth. We carry out a further search to investigate the possibility of meteor shower observations caused by particles ejected from (3552) Don Quixote. The (3552) Don Quixote asteroid was discovered in 1983 as an Amor asteroid. The Tisserand parameter for the orbit has a value of 2.315 with respect to Jupiter, which indicates a comet-like orbit. The diameter of the object calculated from the absolute magnitude, is in the range of 12.3--24.5 km. It all makes Don Quixote a good candidate for a short-period comet among known near-Earth objects, which the recently observed cometary activity confirms [1]. We have investigated the orbital evolution of the meteoroid stream originated from Don Quixote. If the object was active in the past, it might be a parent body for a meteor shower observed on the Earth. The model for the generation and evolution of the meteoroid stream in the Solar System is taken from [2]. The asteroid's orbital elements and physical properties are taken from the JPL horizons website. The ejections of meteoroids from the asteroid surface took place when the asteroid was passing its perihelion between 5000 B.C. and 2013 A.D. Next, the orbits of ejected meteoroids were integrated to the year 2050. If a meteoroid is sufficiently close to the Earth, its orbital parameters are saved and compared with known showers.

  13. Ritualized Embarrassment at "Coed" Wedding and Baby Showers.

    Science.gov (United States)

    Braithwaite, Dawn O.

    1995-01-01

    Finds that women embarrassed men at "coed" wedding and baby showers by teasing and causing them to look unpoised, and that men used avoidance, humor, remediation, and justification strategies. Adds a new strategy, compliance, to previous frameworks to explain males' reaction to embarrassment. Discusses the importance of context and…

  14. Search for a burst of high energy gamma rays using air shower detectors

    International Nuclear Information System (INIS)

    Tsuji, Katsufumi; Konishi, Takeharu; Kitamura, Takashi; Chikawa, Michiyuki.

    1990-01-01

    In order to search for a burst of cosmic high-energy gamma rays, the air shower array has been operated for about 5 months. Measurements have been done on the incidence time, direction and energy of each air shower. The data were analyzed for selecting air showers which had arrived successively at short time intervals. No abnormally high intensity of air shower bursts has been observed, however, the air showers had a tendency that incidence direction is not uniform in the equatorial system. (author)

  15. Meteoroid Environment Modeling: the Meteoroid Engineering Model and Shower Forecasting

    Science.gov (United States)

    Moorhead, Althea V.

    2017-01-01

    The meteoroid environment is often divided conceptually into meteor showers plus a sporadic background component. The sporadic complex poses the bulk of the risk to spacecraft, but showers can produce significant short-term enhancements of the meteoroid flux. The Meteoroid Environment Office (MEO) has produced two environment models to handle these cases: the Meteoroid Engineering Model (MEM) and an annual meteor shower forecast. Both MEM and the forecast are used by multiple manned spaceflight projects in their meteoroid risk evaluation, and both tools are being revised to incorporate recent meteor velocity, density, and timing measurements. MEM describes the sporadic meteoroid complex and calculates the flux, speed, and directionality of the meteoroid environment relative to a user-supplied spacecraft trajectory, taking the spacecraft's motion into account. MEM is valid in the inner solar system and offers near-Earth and cis-lunar environments. While the current version of MEM offers a nominal meteoroid environment corresponding to a single meteoroid bulk density, the next version of MEMR3 will offer both flux uncertainties and a density distribution in addition to a revised near-Earth environment. We have updated the near-Earth meteor speed distribution and have made the first determination of uncertainty in this distribution. We have also derived a meteor density distribution from the work of Kikwaya et al. (2011). The annual meteor shower forecast takes the form of a report and data tables that can be used in conjunction with an existing MEM assessment. Fluxes are typically quoted to a constant limiting kinetic energy in order to comport with commonly used ballistic limit equations. For the 2017 annual forecast, the MEO substantially revised the list of showers and their characteristics using 14 years of meteor flux measurements from the Canadian Meteor Orbit Radar (CMOR). Defunct or insignificant showers were removed and the temporal profiles of many showers

  16. Accelerating Science with Generative Adversarial Networks: An Application to 3D Particle Showers in Multilayer Calorimeters

    Science.gov (United States)

    Paganini, Michela; de Oliveira, Luke; Nachman, Benjamin

    2018-01-01

    Physicists at the Large Hadron Collider (LHC) rely on detailed simulations of particle collisions to build expectations of what experimental data may look like under different theoretical modeling assumptions. Petabytes of simulated data are needed to develop analysis techniques, though they are expensive to generate using existing algorithms and computing resources. The modeling of detectors and the precise description of particle cascades as they interact with the material in the calorimeter are the most computationally demanding steps in the simulation pipeline. We therefore introduce a deep neural network-based generative model to enable high-fidelity, fast, electromagnetic calorimeter simulation. There are still challenges for achieving precision across the entire phase space, but our current solution can reproduce a variety of particle shower properties while achieving speedup factors of up to 100 000 × . This opens the door to a new era of fast simulation that could save significant computing time and disk space, while extending the reach of physics searches and precision measurements at the LHC and beyond.

  17. Do cosmic ray air showers initiate lightning? : A statistical analysis of cosmic ray air showers and lightning mapping array data

    NARCIS (Netherlands)

    Hare, B. M.; Dwyer, J. R.; Winner, L. H.; Uman, M. A.; Jordan, D. M.; Kotovsky, D. A.; Caicedo, J. A.; Wilkes, R. A.; Carvalho, F. L.; Pilkey, J. T.; Ngin, T. K.; Gamerota, W. R.; Rassoul, H. K.

    2017-01-01

    It has been argued in the technical literature, and widely reported in the popular press, that cosmic ray air showers (CRASs) can initiate lightning via a mechanism known as relativistic runaway electron avalanche (RREA), where large numbers of high-energy and low-energy electrons can, somehow,

  18. Cascade Mountain Range in Oregon

    Science.gov (United States)

    Sherrod, David R.

    2016-01-01

    The Cascade mountain system extends from northern California to central British Columbia. In Oregon, it comprises the Cascade Range, which is 260 miles long and, at greatest breadth, 90 miles wide (fig. 1). Oregon’s Cascade Range covers roughly 17,000 square miles, or about 17 percent of the state, an area larger than each of the smallest nine of the fifty United States. The range is bounded on the east by U.S. Highways 97 and 197. On the west it reaches nearly to Interstate 5, forming the eastern margin of the Willamette Valley and, farther south, abutting the Coast Ranges. 

  19. Inferring network structure from cascades

    Science.gov (United States)

    Ghonge, Sushrut; Vural, Dervis Can

    2017-07-01

    Many physical, biological, and social phenomena can be described by cascades taking place on a network. Often, the activity can be empirically observed, but not the underlying network of interactions. In this paper we offer three topological methods to infer the structure of any directed network given a set of cascade arrival times. Our formulas hold for a very general class of models where the activation probability of a node is a generic function of its degree and the number of its active neighbors. We report high success rates for synthetic and real networks, for several different cascade models.

  20. The 2018 Meteor Shower Activity Forecast for Earth Orbit

    Science.gov (United States)

    Moorhead, Althea; Cooke, Bill; Moser, Danielle

    2017-01-01

    A number of meteor showers - the Ursids, Perseids, Leonids, eta Aquariids, Orionids, Draconids, and Andromedids - are predicted to exhibit increased rates in 2018. However, no major storms are predicted, and none of these enhanced showers outranks the typical activity of the Arietids, Southern delta Aquariids, and Geminids at small particle sizes. The MSFC stream model1 predicts higher than usual activity for the Ursid meteor shower in December 2018. While we expect an increase in activity, rates will fall short of the shower's historical outbursts in 1945 and 1986 when the zenithal hourly rate (ZHR) exceeded 100. Instead, the expected rate for 2018 is around 70. The Perseids, Leonids, eta Aquariids, and Orionids are expected to show mild enhancements over their baseline activity level in 2018. In the case of the Perseids, we may see an additional peak in activity a few hours before the traditional peak, but we do not expect activity levels as high as those seen in 2016 and 2017. The eta Aquariids and Orionids, which belong to a single meteoroid stream generated by comet 1P/Halley, are thought to have a 12-year activity cycle and are currently increasing in activity from year to year. Finally, we may see minor outbursts of the Draconids and Andromedids in 2018. Both showers have been difficult to model and have produced unexpected outbursts in recent years (the Draconids in 2012 and the Andromedids in 2011 and 2013). The Andromedids may produce two peaks, both of which are listed in Table 2. This document is designed to supplement spacecraft risk assessments that incorporate an annual averaged meteor shower flux (as is the case with all NASA meteoroid models). Results are presented relative to this baseline and are weighted to a constant kinetic energy. Two showers - the Daytime Arietids (ARI) and the Geminids (GEM) - attain flux levels approaching that of the baseline meteoroid environment for 0.1-cm-equivalent meteoroids. This size is the threshold for structural

  1. Cascade orificial resistive device

    Science.gov (United States)

    Bitsakis, Nicholas; Cassidy, James

    1994-07-01

    A cascade orificial resistive device for throttling fluid flow which minimizes acoustic noise and internal vibrations is described herein. The device has a hollow body defining a fluid passageway, a plurality of perforated plates mounted within the passageway, a fixed end ring adjacent one end of the perforated plates, and a threadable end ring adjacent an opposite end of the perforated plates to place the plates in compression. Each of the perforated plates is a single piece molded plate having an integral outer ring and an integrally formed center keying mechanism as well as a plurality of orifices. The keying mechanism formed on each plate is designed so that adjacent ones of the plates have their orifices misaligned. In this manner, a pressure drop across each plate is created and the fluid flow through the device is throttled. The device of the present invention has utility in a number of onboard marine vessel systems wherein reduced acoustic noise and internal vibrations are particularly desirable.

  2. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-01-01

    A two-phase cascade code, LUCIFER II, developed for the treatment of ultra high energy-ion-ion collisions is applied to the production of strangeness at SPS energies √(s)=17-20. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy-ion experiments at the CERN SPS. (orig.)

  3. Ultrarelativistic cascades and strangeness production

    Energy Technology Data Exchange (ETDEWEB)

    Kahana, D.E. [State Univ. of New York, Stony Brook, NY (United States). Physics Dept.; Kahana, S.H. [Brookhaven National Lab., Upton, NY (United States). Physics Dept.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS.

  4. Ultrarelativistic cascades and strangeness production

    International Nuclear Information System (INIS)

    Kahana, D.E.; Kahana, S.H.

    1998-02-01

    A two phase cascade, LUCIFER II, developed for the treatment of ultra high energy Ion-Ion collisions is applied to the production of strangeness at SPS energies. This simulation is able to simultaneously describe both hard processes such as Drell-Yan and slower, soft processes such as the production of light mesons by separating the dynamics into two steps, a fast cascade involving only the nucleons in the original colliding relativistic ions followed, after an appropriate delay, by a normal multiscattering of the resulting excited baryons and mesons produced virtually in the first step. No energy loss can take place in the short time interval over which the first cascade takes place. The chief result is a reconciliation of the important Drell-Yan measurements with the apparent success of standard cascades to describe the nucleon stopping and meson production in heavy ion experiments at the CERN SPS

  5. Computation of inverse magnetic cascades

    International Nuclear Information System (INIS)

    Montgomery, D.

    1981-10-01

    Inverse cascades of magnetic quantities for turbulent incompressible magnetohydrodynamics are reviewed, for two and three dimensions. The theory is extended to the Strauss equations, a description intermediate between two and three dimensions appropriate to tokamak magnetofluids. Consideration of the absolute equilibrium Gibbs ensemble for the system leads to a prediction of an inverse cascade of magnetic helicity, which may manifest itself as a major disruption. An agenda for computational investigation of this conjecture is proposed

  6. Stochastic background of atmospheric cascades

    International Nuclear Information System (INIS)

    Wilk, G.; Wlodarczyk, Z.

    1993-01-01

    Fluctuations in the atmospheric cascades developing during the propagation of very high energy cosmic rays through the atmosphere are investigated using stochastic branching model of pure birth process with immigration. In particular, we show that the multiplicity distributions of secondaries emerging from gamma families are much narrower than those resulting from hadronic families. We argue that the strong intermittent like behaviour found recently in atmospheric families results from the fluctuations in the cascades themselves and are insensitive to the details of elementary interactions

  7. Correlation Structure of Wavelet Cascades

    Science.gov (United States)

    Greiner, Martin; Giesemann, Jens

    The following sections are included: * Introduction * Some Basics about Wavelets * Multiresolution analysis * Dilation equations * Wavelet transformation * Multiplicative Haar-Wavelet Cascade * Binary random multiplicative branching processes * n-point correlation densities * Haar-wavelet transformed correlation densities * Daubechies-wavelet transformed correlation densities * Multiplicative Daubechies-Wavelet Cascade * Random multiplicative branching processes on a D4-wavelet tree * n-point correlation densities * Wavelet transformed correlation densities * Scaling behavior of moments * Conclusion * REFERENCES

  8. The Effect of New Shower Facilities on Physical Activity Behaviors of Employees: A Quasi-experiment.

    Science.gov (United States)

    Nehme, Eileen K; Pérez, Adriana; Ranjit, Nalini; Amick, Benjamin C; Kohl, Harold W

    2017-02-01

    This quasi-experimental study assessed the effects of new workplace showers on physical activity behaviors in a sample of downtown employees in Austin, TX. The study design was quasi-experimental with 2 comparison groups. Data were collected via internet-based surveys before and 4 months after shower installation at 1 worksite. Differences across study groups in the ranks of change in past-week minutes of physical activity from baseline to follow-up were assessed. Adjusted odds ratios and 95% confidence intervals for reporting an increase of ≥10 min past-week physical activity and workday physical activity among those with new showers and existing showers relative to those with no showers were also assessed. No significant differences in changes in physical activity from baseline to follow-up across study groups were found. One-quarter of participants with new workplace showers and 46.9% of those with existing workplace showers at baseline reported ever using the showers. This prospective study did not find significant changes in employee physical activity 4 months after installation of worksite showers. Worksite shower users were highly active at baseline, suggesting a possible early adopter effect, with potential for diffusion. Future studies may benefit from longer exposure times and larger samples.

  9. Interband Cascade Photovoltaic Cells

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Rui Q. [Univ. of Oklahoma, Norman, OK (United States); Santos, Michael B. [Univ. of Oklahoma, Norman, OK (United States); Johnson, Matthew B. [Univ. of Oklahoma, Norman, OK (United States)

    2014-09-24

    In this project, we are performing basic and applied research to systematically investigate our newly proposed interband cascade (IC) photovoltaic (PV) cells [1]. These cells follow from the great success of infrared IC lasers [2-3] that pioneered the use of quantum-engineered IC structures. This quantum-engineered approach will enable PV cells to efficiently convert infrared radiation from the sun or other heat source, to electricity. Such cells will have important applications for more efficient use of solar energy, waste-heat recovery, and power beaming in combination with mid-infrared lasers. The objectives of our investigations are to: achieve extensive understanding of the fundamental aspects of the proposed PV structures, develop the necessary knowledge for making such IC PV cells, and demonstrate prototype working PV cells. This research will focus on IC PV structures and their segments for utilizing infrared radiation with wavelengths from 2 to 5 μm, a range well suited for emission by heat sources (1,000-2,000 K) that are widely available from combustion systems. The long-term goal of this project is to push PV technology to longer wavelengths, allowing for relatively low-temperature thermal sources. Our investigations address material quality, electrical and optical properties, and their interplay for the different regions of an IC PV structure. The tasks involve: design, modeling and optimization of IC PV structures, molecular beam epitaxial growth of PV structures and relevant segments, material characterization, prototype device fabrication and testing. At the end of this program, we expect to generate new cutting-edge knowledge in the design and understanding of quantum-engineered semiconductor structures, and demonstrate the concepts for IC PV devices with high conversion efficiencies.

  10. A silicon pad shower maximum detector for a Shashlik calorimeter

    International Nuclear Information System (INIS)

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.

    1995-01-01

    The new luminosity monitor of the DELPHI detector, STIC (Small angle TIle Calorimeter), was built using a Shashlik technique. This technique does not provide longitudinal sampling of the showers, which limits the measurement of the direction of the incident particles and the e-π separation. For these reasons STIC was equipped with a Silicon Pad Shower Maximum Detector (SPSMD). In order to match the silicon detectors to the Shashlick read out by wavelength shifter (WLS) fibers, the silicon wafers had to be drilled with a precision better than 10μm without damaging the active area of the detectors. This paper describes the SPSMD with emphasis on the fabrication techniques and on the components used. Some preliminary results of the detector performance from data taken with a 45GeV electron beam at CERN are presented. (orig.)

  11. Resistive Plate Chamber Digitization in a Hadronic Shower Environment

    CERN Document Server

    Deng, Z.

    2016-06-28

    The CALICE Semi-Digital Hadron Calorimeter (SDHCAL) technological prototype is a sampling calorimeter using Glass Resistive Plate Chamber detectors with a three-threshold readout as the active medium. This technology is one of the two options proposed for the hadron calorimeter of the International Large Detector for the International Linear Collider. The prototype was exposed to beams of muons, electrons and pions of different energies at the CERN Super Proton Synchrotron. To be able to study the performance of such a calorimeter in future experiments it is important to ensure reliable simulation of its response. In this paper we present our prototype simulation performed with GEANT4 and the digitization procedure achieved with an algorithm called SimDigital. A detailed description of this algorithm is given and the methods to determinate its parameters using muon tracks and electromagnetic showers are explained. The comparison with hadronic shower data shows a good agreement up to 50 GeV. Discrepancies are ...

  12. Uncertainty from Extrapolation of Cosmic Ray Air Shower Parameters

    Science.gov (United States)

    Abbasi, Rasha; Thomson, Gordon

    In this work we investigate the uncertainties in the prediction of the average shower maximum, , by the currently used high energy cosmic ray shower simulation models. Recent measurements at the LHC have provided constrains on some of the parameters in these models. However, uncertainties in the prediction of remain due to extrapolation from accelerator data up to center of mass of 250 TeV. The extrapolation in the elasticity, multiplicity, and p-p cross section from the LHC energy range to 3 × 1019 eV in a cosmic ray's lab frame is investigated in this proceeding. Our calculation of the uncertainty in is approximately equal to the difference among the modern models being used in the field.

  13. Matching fully differential NNLO calculations and parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Alioli, Simone; Bauer, Christian W.; Berggren, Calvin; Walsh, Jonathan R.; Zuberi, Saba [California Univ., Berkeley, CA (United States). Ernest Orlando Lawrence Berkeley National Laboratory; Tackmann, Frank J. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

    2013-11-15

    We present a general method to match fully differential next-to-next-to-leading (NNLO) calculations to parton shower programs. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy. Our method is based on consistently improving a given NNLO calculation with the leading-logarithmic (LL) resummation in a chosen jet resolution variable. The resulting NNLO+LL calculation is cast in the form of an event generator for physical events that can be directly interfaced with a parton shower routine, and we give an explicit construction of the input ''Monte Carlo cross sections'' satisfying all required criteria. We also show how other proposed approaches naturally arise as special cases in our method.

  14. Combining states without scale hierarchies with ordered parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Fischer, Nadine [Monash University, School of Physics and Astronomy, Clayton, VIC (Australia); Prestel, Stefan [Fermi National Accelerator Laboratory, Batavia, IL (United States)

    2017-09-15

    We present a parameter-free scheme to combine fixed-order multi-jet results with parton-shower evolution. The scheme produces jet cross sections with leading-order accuracy in the complete phase space of multiple emissions, resumming large logarithms when appropriate, while not arbitrarily enforcing ordering on momentum configurations beyond the reach of the parton-shower evolution equation. This requires the development of a matrix-element correction scheme for complex phase-spaces including ordering conditions as well as a systematic scale-setting procedure for unordered phase-space points. The resulting algorithm does not require a merging-scale parameter. We implement the new method in the Vincia framework and compare to LHC data. (orig.)

  15. Calibration and monitoring of the ARGUS shower counters

    International Nuclear Information System (INIS)

    Drescher, A.; Matthiesen, U.; Scheck, H.; Spaan, B.; Spengler, J.; Wegener, D.; Heller, R.; Schubert, K.R.; Stiewe, J.; Weseler, S.

    1986-02-01

    The 1760 shower counter modules of the detector ARGUS at DORIS II are monitored by a laser as the central light source. A lead glass counter, which also detects cosmic muons, and a photodiode serve as reference systems. The paper describes the technical layout, performance and stability of the monitoring system. Algorithms and corrections applied in the calibration procedure are discussed in detail. The monitoring system serves also to control the time-of-flight counter performance and to calibrate their TDCs. (orig.)

  16. Review of Accelerator Experiments Relevant to Air Shower Development

    Science.gov (United States)

    Sako, Takashi

    Hadronic interaction models are extensively tested using the LHC data since its beginning in 2009. The paper reviews the LHC results relevant to air shower modeling. Measurements of forward particle productions are especially focused because they carry a large fraction of collision energy. The paper reviews not only the LHC results, but also covers a fixed-target experiment and a lower energy collider experiment. A future possibility of LHC light-ion collisions is also discussed.

  17. Calibration and monitoring of the ARGUS shower counters

    International Nuclear Information System (INIS)

    Drescher, A.; Matthiesen, U.; Scheck, H.; Spaan, B.; Spengler, J.; Wegener, D.; Heller, R.; Schubert, K.R.; Stiewe, J.; Weseler, S.

    1986-01-01

    The 1760 shower counter modules of the detector ARGUS at DORIS II are monitored by a laser as the central light source. A lead glass counter, which also detects cosmic muons, and a photodiode serve as reference systems. The paper describes the technical layout, performance and stability of the monitoring system. Algorithms and corrections applied in the calibration procedure are discussed in detail. The monitoring system serves also to control the time-of-flight counter performance and to calibrate their TDCs. (orig.)

  18. On the Impact of Tsallis Statistics on Cosmic Ray Showers

    Directory of Open Access Journals (Sweden)

    M. Abrahão

    2016-01-01

    Full Text Available We investigate the impact of the Tsallis nonextensive statistics introduced by intrinsic temperature fluctuations in p-Air ultrahigh energy interactions on observables of cosmic ray showers, such as the slant depth of the maximum Xmax and the muon number on the ground Nμ. The results show that these observables are significantly affected by temperature fluctuations and agree qualitatively with the predictions of Heitler model.

  19. Detection of electron showers in dual-readout crystal calorimeters

    International Nuclear Information System (INIS)

    Akchurin, N.; Bedeschi, F.; Cardini, A.; Cascella, M.; Ciapetti, G.; D'Orazio, A.; Collica, L.; De Pedis, D.; Ferrari, R.; Franchino, S.; Fraternali, M.; Gaudio, G.; Genova, P.; Hauptman, J.; Lacava, F.; La Rotonda, L.; Lee, S.; Livan, M.; Meoni, E.; Negri, A.

    2012-01-01

    Some high-Z scintillating crystals offer the possibility to distinguish the contributions from the scintillation and Čherenkov mechanisms to the generated signals. Among these crystals are BGO and PbWO 4 . We have tested matrices of these crystals as electromagnetic calorimeters and studied the properties of the Čherenkov and scintillation components of the signals generated by high-energy electrons showering in these detectors.

  20. EGS4, Electron Photon Shower Simulation by Monte-Carlo

    International Nuclear Information System (INIS)

    1998-01-01

    1 - Description of program or function: The EGS code system is one of a chain of three codes designed to solve the electromagnetic shower problem by Monte Carlo simulation. This chain makes possible simulation of almost any electron-photon transport problem conceivable. The structure of the system, with its global features, modular form, and structured programming, is readily adaptable to virtually any interfacing scheme that is desired on the part of the user. EGS4 is a package of subroutines plus block data with a flexible user interface. This allows for greater flexibility without requiring the user to be overly familiar with the internal details of the code. Combining this with the macro facility capabilities of the Mortran3 language, this reduces the likelihood that user edits will introduce bugs into the code. EGS4 uses material cross section and branching ratio data created and fit by the companion code, PEGS4. EGS4 allows for the implementation of importance sampling and other variance reduction techniques such as leading particle biasing, splitting, path length biasing, Russian roulette, etc. 2 - Method of solution: EGS employs the Monte Carlo method of solution. It allows all of the fundamental processes to be included and arbitrary geometries can be treated, also. Other minor processes, such as photoneutron production, can be added as a further generalization. Since showers develop randomly according to the quantum laws of probability, each shower is different. We again are led to the Monte Carlo method. 3 - Restrictions on the complexity of the problem: None noted

  1. Producing EGS4 shower displays with the Unified Graphics System

    International Nuclear Information System (INIS)

    Cowan, R.F.

    1990-01-01

    The EGS4 Code System has been coupled with the SLAC Unified Graphics System in such a manner as to provide a means for displaying showers on UGS77-supported devices. This is most easily accomplished by attaching an auxiliary subprogram package (SHOWGRAF) to existing EGS4 User Codes and making use of a graphics display or a post-processor code called EGS4PL. SHOWGRAF may be used to create shower displays directly on interactive IBM 5080 color display devices, supporting three-dimensional rotations, translations, and zoom features, and providing illustration of particle types and energies by color and/or intensity. Alternatively, SHOWGRAF may be used to record a two-dimensional projection of the shower in a device-independent graphics file. The EGS4PL post-processor may then be used to convert this file into device-dependent graphics code for any UGS77-supported device. Options exist within EGS4PL that allow for two-dimensional translations and zoom, for creating line structure to indicate particle types and energies, and for optional display of particles by type. All of this is facilitated by means of the command processor EGS4PL EXEC together with new options (5080 and PDEV) with the standard EGS4IN EXEC routine for running EGS4 interactively under VM/SP. 6 refs

  2. Spatial requirements in hospital shower and toilet rooms.

    Science.gov (United States)

    Hignett, S; Evans, D

    To determine the spatial requirements for hoist use in an assisted shower-toilet facility. A simulation of two shower-toilet facilities (built since 2000) was constructed in a laboratory to compare a mobile hoist and a gantry (overhead) hoist for the task of transferring a patient from a wheelchair to the toilet. Twenty participants were recruited and trained in the use of both hoists. Data were recorded using video cameras and analysed for the space used to complete the task, time taken and postural risk scores. The mobile hoist needed significantly more space, took significantly longer and exposed the handlers to higher postural risks than the overhead hoist. Larger shower-toilet rooms should be planned and built as accessible facilities with sufficient space for independent and assisted wheelchair users. The findings will have an impact on the recommendation for increased numbers of single rooms with ensuite facilities in new hospitals. Healthcare planners and designers may need to consider building specific facilities for assisted wheelchair users rather than providing a 'one space fits all' solution.

  3. A Large Ordinary Chondrite Shower in the Dominion Range

    Science.gov (United States)

    Satterwhite, C. E.; Righter, K.; Harrington, R.; McBride, K. M.; Funk, R.

    2017-01-01

    The US Antarctic Meteorite Program has visited the Dominion Range in the Transantarctic Mountains during several different seasons, including the 1985, 2003, 2008, 2010, and 2014 seasons. Total recovered meteorites from this region is over 2000. The 2008 and 2010 seasons have been fully classified and, respectively) revealing the presence of a large meteorite shower that comprises approximately 60% of all samples recovered in those two seasons. The oil immersion classification suggests that this shower is LL chondrite material, whereas published magnetic susceptibility (MS; log chi) measurements yield L chondrite values. However, usually random sampling of a large collection like this would uncover EOC material for which we have prepared thin sections. In this case, no LL chondrite materials have been found in thin section, suggesting that the shower might instead be an L chondrite. L and LL chondrites are notoriously difficult to distinguish using oil immersion techniques. To better characterize this large group of samples, we have decided to examine some of the large members of this group, using EMPA analysis of the olivines to verify the classifications. With a compositional link between this subset of samples, and the MS measurements, we can more confidently classify the samples making up this pairing group. Subsequently, more accurate and meaningful comparisons may be drawn between this pairing group and some other Antarctic pairing groups such as from the Queen Alexandra Range (QUE), and Lewis Cliffs Ice Tongue (LEW). electron microprobe analysis

  4. Cerenkov radio pulses from electromagnetic showers in the time domain

    International Nuclear Information System (INIS)

    Alvarez-Muniz, Jaime; Romero-Wolf, Andres; Zas, Enrique

    2010-01-01

    The electric field of the Cerenkov radio pulse produced by a single charged particle track in a dielectric medium is derived from first principles. An algorithm is developed to obtain the pulse in the time domain for numerical calculations. The algorithm is implemented in a Monte Carlo simulation of electromagnetic showers in dense media (specifically designed for coherent radio emission applications) as might be induced by interactions of ultrahigh energy neutrinos. The coherent Cerenkov radio emission produced by such showers is obtained simultaneously both in the time and frequency domains. A consistency check performed by Fourier transforming the pulse in time and comparing it to the frequency spectrum obtained directly in the simulations yields, as expected, fully consistent results. The reversal of the time structure inside the Cerenkov cone and the signs of the corresponding pulses are addressed in detail. The results, besides testing algorithms used for reference calculations in the frequency domain, shed new light into the properties of the radio pulse in the time domain. The shape of the pulse in the time domain is directly related to the depth development of the excess charge in the shower and its width to the observation angle with respect to the Cerenkov direction. This information can be of great practical importance for interpreting actual data.

  5. A robotic shower system : Acceptance and ethical issues.

    Science.gov (United States)

    Klein, Barbara; Schlömer, Inga

    2018-01-01

    Being able to maintain personal hygiene plays a crucial role for independent living in old age or when suffering from disabilities. Within the European project ICT Supported Bath Robots (I‑SUPPORT) an intelligent robotic shower system is being developed, which enables patients to shower independently at home or in institutionalized settings. The aim of this contribution is the identification of ethical issues in the development of a robotic shower system utilizing the model for the ethical evaluation of socio-technical arrangements (MEESTAR). In I‑SUPPORT a variety of concepts and methods are implemented in order to achieve technology acceptance such as user-centered requirements analysis, usability-tests and analysis of sociocultural and ethical aspects. This article reports the analysis of focus groups with 14 older adults and 9 professional caregivers utilizing MEESTAR as a heuristic approach for analyzing sociotechnical arrangements and identifying ethical problems. The MEESTAR procedure was adapted to the research question and client groups and implemented as a discursive method. This gave an insight into the meaning and background of ethical aspects and also a deeper insight into nursing processes as well as the requirements which the system should fulfil. Shortcomings are that the ethical dimensions are not everyday language and the time restrictions. In the next step a standardized assessment instrument will be developed and piloted.

  6. Parameterized Shower Simulation in Lelaps: a Comparison with Geant4

    Energy Technology Data Exchange (ETDEWEB)

    Langeveld, Willy G.J.

    2003-09-02

    The detector simulation toolkit Lelaps[1] simulates electromagnetic and hadronic showers in calorimetric detector elements of high-energy particle detectors using a parameterization based on the algorithms originally developed by Grindhammer and Peters[2] and Bock et al.[3]. The primary motivations of the present paper are to verify the implementation of the parameterization, to explore regions of energy where the parameterization is valid and to serve as a basis for further improvement of the algorithm. To this end, we compared the Lelaps simulation to a detailed simulation provided by Geant4[4]. A number of different calorimeters, both electromagnetic and hadronic, were implemented in both programs. Longitudinal and radial shower profiles and their fluctuations were obtained from Geant4 over a wide energy range and compared with those obtained from Lelaps. Generally the longitudinal shower profiles are found to be in good agreement in a large part of the energy range, with poorer results at energies below about 300 MeV. Radial profiles agree well in homogeneous detectors, but are somewhat deficient in segmented ones. These deficiencies are discussed.

  7. Nontuberculous mycobacterial hypersensitivity pneumonitis related to a home shower: treatment and secondary prevention.

    Science.gov (United States)

    Hankwitz, Paul E; Cervia, Joseph Steven; Thomas, Charles F; Fink, Jordan N; Marras, Ted; Tomic, Rade

    2011-07-28

    A 57-year-old physician with increasing dyspnoea and hypoxaemia had a high-resolution CT scan of the chest, which disclosed diffuse pulmonary ground glass opacities, more pronounced in the upper lobes with minimal mediastinal lymphadenopathy. Transbronchial biopsy of the right middle and lower lobes was performed, demonstrating varying degrees of well circumscribed organising granulomatous pneumonitis thought to be most consistent with hypersensitivity to nontuberculous mycobacteria. Cultures of water obtained from the patient's home shower were positive for Mycobacterium avium complex. The patient began substituting baths for showers, experiencing some gradual improvement of his symptoms. Subsequently, he installed point-of-use 0.2 micron membrane filters on his shower, and resumed regular showering after installation with continued symptomatic improvement. CT scans at 3 and 18 months revealed improvement and resolution, respectively. Four years later, he continues to shower in filtered home shower water and remains clinically well.

  8. Potentially Pathogenic Bacteria in Shower Water and Air of a Stem Cell Transplant Unit▿

    Science.gov (United States)

    Perkins, Sarah D.; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T.

    2009-01-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 × 107 cells/liter in shower water and 3.4 × 104 cells/m3 in shower aerosol, and these counts were reduced to 6.3 × 104 cells/liter (99.6% efficiency) and 8.9 × 103 cells/m3 (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from anticipated

  9. Search for long-lived massive particles and time structure of electrons in extensive air showers

    International Nuclear Information System (INIS)

    Yoshida, Mamoru; Toyoda, Yoshio; Maeda, Toshiro

    1984-01-01

    An experiment to observe accompanied showers delayed relative to the bulk of extensive-air-shower particles near the core was carried out by using plural detectors set at separate places. Four delayed events hitting two or more detectors at the same time were observed. It is difficult to explain these events by accidental coincidence or conventional processes. However, these events can be explained, provided that a parent particle producing the delayed shower has a lifetime of the order of 1 x 10 -6 s and is heavier than a nucleon. The thickness of air shower disk was also measured at core distances less than 50 m. (author)

  10. The Use of D-Criteria to Assess Meteor Shower Significance

    Science.gov (United States)

    Moorhead, Althea V.

    2017-01-01

    In theory, a meteor shower can be distinguished from the sporadic meteor background by its short duration and orbital similarity. In practice, the duration and strength of a shower and the orbital similarity between its constituent meteors varies widely between showers. Further complicating matters is the anisotropy of the sporadic background. These combined factors make it difficult to distinguish between shower and sporadic meteors with a single, static set of criteria. The orbital similarity, or D-, parameters are often used to assess the relationship between meteors [1,2,3]. The more dissimilar two orbits are, the higher their computed D value will be; generally, meteors are considered related if their D-parameter falls below some cutoff value [4]. However, this approach will include some sporadic meteors, and when a weak shower lies near a sporadic source, the false positive rate for shower association can be quite high. Additionally, this cutoff approach does not assess whether the shower itself is significant. We present a method for using D-parameters to extract showers from a dataset that automatically takes shower strength into account and tests for significance [5]. We accomplish this by calculating the false positive rate for shower association using "shower analogs," which are identical to the original shower except in solar longitude. This method is applied to a set of more than 30,000 meteors detected by the NASA All-Sky Fireball Network [6] and the Southern Ontario Meteor Network (SOMN) [7]. We previously detected 29 showers in our data using this method [5]; now, with another year of data, we have several additional detections. Figure 1 presents one example: the 2016 July gamma Draconid outburst. There are several benefits to using our method. First, it provides a test of shower significance (see Fig. 2 for an example of a non-detection). Second, it quantifies the probability that a meteor belongs to a given shower as a function of D

  11. Study of the lateral and temporal structure of the shower front in KASCADE-Grande at large distances from the shower core

    International Nuclear Information System (INIS)

    Toma, G.; Badea, A.F.; Haungs, A.; Rebel, H.; Thouw, T.

    2003-01-01

    The purpose of this study was to obtain information about the temporal and spatial structure of the shower front at KASKADE-Grande distances. For such a purpose, temporal observables (global arrival times of particles) and lateral particle densities in the shower front have been analyzed. The analysis concentrated only on simulated events. The analysis concentrated exclusively on the data contained in 150 simulated showers, 50 showers for each kind of the following primary particles: p, C and Fe. The showers were simulated for the same energy of the primary particle (10 16 eV) and for the same angle of incidence theta = 0 (vertical showers). Also the study has been performed for different components of the shower front: muonic, electronic, electromagnetic and hadronic. The results show that the arrival time distributions are different for the same EAS component at different threshold energies. As the scattering cross section decreases with energy, higher energy particles will be less scattered so will take a shorter time to reach detector level, thus inducing an overall decrease of arrival time. Also the cuartile times that have been calculated proved to be primary mass sensitive. The second stage of the study focused on the analysis of the lateral structure of the shower front. The lateral density of the added muon - electron components was fitted with a modified NKG formula containing two parameters (a and h) of which one also proved to be primary mass sensitive. A future step of the study will be to consider the interaction between shower front and detectors in order to obtain a much realistic estimate of the KASCADE Grande array response. (authors)

  12. Isolation of nontuberculous mycobacteria (NTM) from household water and shower aerosols in patients with pulmonary disease caused by NTM.

    Science.gov (United States)

    Thomson, Rachel; Tolson, Carla; Carter, Robyn; Coulter, Chris; Huygens, Flavia; Hargreaves, Megan

    2013-09-01

    It has been postulated that susceptible individuals may acquire infection with nontuberculous mycobacteria (NTM) from water and aerosol exposure. This study examined household water and shower aerosols of patients with NTM pulmonary disease. The mycobacteria isolated from clinical samples from 20 patients included M. avium (5 patients), M. intracellulare (12 patients), M. abscessus (7 patients), M. gordonae (1 patient), M. lentiflavum (1 patient), M. fortuitum (1 patient), M. peregrinum (1 patient), M. chelonae (1 patient), M. triplex (1 patient), and M. kansasii (1 patient). One-liter water samples and swabs were collected from all taps, and swimming pools or rainwater tanks. Shower aerosols were sampled using Andersen six-stage cascade impactors. For a subgroup of patients, real-time PCR was performed and high-resolution melt profiles were compared to those of ATCC control strains. Pathogenic mycobacteria were isolated from 19 homes. Species identified in the home matched that found in the patient in seven (35%) cases: M. abscessus (3 cases), M. avium (1 case), M. gordonae (1 case), M. lentiflavum (1 case), and M. kansasii (1 case). In an additional patient with M. abscessus infection, this species was isolated from potable water supplying her home. NTM grown from aerosols included M. abscessus (3 homes), M. gordonae (2 homes), M. kansasii (1 home), M. fortuitum complex (4 homes), M. mucogenicum (1 home), and M. wolinskyi (1 home). NTM causing human disease can be isolated from household water and aerosols. The evidence appears strongest for M. avium, M. kansasii, M. lentiflavum, and M. abscessus. Despite a predominance of disease due to M. intracellulare, we found no evidence for acquisition of infection from household water for this species.

  13. Search for neutrino-induced particle showers with IceCube-40

    Science.gov (United States)

    Aartsen, M. G.; Abbasi, R.; Ackermann, M.; Adams, J.; Aguilar, J. A.; Ahlers, M.; Altmann, D.; Arguelles, C.; Arlen, T. C.; Auffenberg, J.; Bai, X.; Baker, M.; Barwick, S. W.; Baum, V.; Bay, R.; Beatty, J. J.; Becker Tjus, J.; Becker, K.-H.; BenZvi, S.; Berghaus, P.; Berley, D.; Bernardini, E.; Bernhard, A.; Besson, D. Z.; Binder, G.; Bindig, D.; Bissok, M.; Blaufuss, E.; Blumenthal, J.; Boersma, D. J.; Bohm, C.; Bose, D.; Böser, S.; Botner, O.; Brayeur, L.; Bretz, H.-P.; Brown, A. M.; Bruijn, R.; Casey, J.; Casier, M.; Chirkin, D.; Christov, A.; Christy, B.; Clark, K.; Classen, L.; Clevermann, F.; Coenders, S.; Cohen, S.; Cowen, D. F.; Cruz Silva, A. H.; Danninger, M.; Daughhetee, J.; Davis, J. C.; Day, M.; de André, J. P. A. M.; De Clercq, C.; De Ridder, S.; Desiati, P.; de Vries, K. D.; de With, M.; DeYoung, T.; Díaz-Vélez, J. C.; Dunkman, M.; Eagan, R.; Eberhardt, B.; Eichmann, B.; Eisch, J.; Euler, S.; Evenson, P. A.; Fadiran, O.; Fazely, A. R.; Fedynitch, A.; Feintzeig, J.; Feusels, T.; Filimonov, K.; Finley, C.; Fischer-Wasels, T.; Flis, S.; Franckowiak, A.; Frantzen, K.; Fuchs, T.; Gaisser, T. K.; Gallagher, J.; Gerhardt, L.; Gladstone, L.; Glüsenkamp, T.; Goldschmidt, A.; Golup, G.; Gonzalez, J. G.; Goodman, J. A.; Góra, D.; Grandmont, D. T.; Grant, D.; Gretskov, P.; Groh, J. C.; Groß, A.; Ha, C.; Haj Ismail, A.; Hallen, P.; Hallgren, A.; Halzen, F.; Hanson, K.; Hebecker, D.; Heereman, D.; Heinen, D.; Helbing, K.; Hellauer, R.; Hickford, S.; Hill, G. C.; Hoffman, K. D.; Hoffmann, R.; Homeier, A.; Hoshina, K.; Huang, F.; Huelsnitz, W.; Hulth, P. O.; Hultqvist, K.; Hussain, S.; Ishihara, A.; Jacobi, E.; Jacobsen, J.; Jagielski, K.; Japaridze, G. S.; Jero, K.; Jlelati, O.; Kaminsky, B.; Kappes, A.; Karg, T.; Karle, A.; Kauer, M.; Kelley, J. L.; Kiryluk, J.; Kläs, J.; Klein, S. R.; Köhne, J.-H.; Kohnen, G.; Kolanoski, H.; Köpke, L.; Kopper, C.; Kopper, S.; Koskinen, D. J.; Kowalski, M.; Krasberg, M.; Kriesten, A.; Krings, K.; Kroll, G.; Kunnen, J.; Kurahashi, N.; Kuwabara, T.; Labare, M.; Landsman, H.; Larson, M. J.; Lesiak-Bzdak, M.; Leuermann, M.; Leute, J.; Lünemann, J.; Macías, O.; Madsen, J.; Maggi, G.; Maruyama, R.; Mase, K.; Matis, H. S.; McNally, F.; Meagher, K.; Merck, M.; Meures, T.; Miarecki, S.; Middell, E.; Milke, N.; Miller, J.; Mohrmann, L.; Montaruli, T.; Morse, R.; Nahnhauer, R.; Naumann, U.; Niederhausen, H.; Nowicki, S. C.; Nygren, D. R.; Obertacke, A.; Odrowski, S.; Olivas, A.; Omairat, A.; O'Murchadha, A.; Palczewski, T.; Paul, L.; Pepper, J. A.; Pérez de los Heros, C.; Pfendner, C.; Pieloth, D.; Pinat, E.; Posselt, J.; Price, P. B.; Przybylski, G. T.; Quinnan, M.; Rädel, L.; Rameez, M.; Rawlins, K.; Redl, P.; Reimann, R.; Resconi, E.; Rhode, W.; Ribordy, M.; Richman, M.; Riedel, B.; Robertson, S.; Rodrigues, J. P.; Rott, C.; Ruhe, T.; Ruzybayev, B.; Ryckbosch, D.; Saba, S. M.; Sander, H.-G.; Santander, M.; Sarkar, S.; Schatto, K.; Scheriau, F.; Schmidt, T.; Schmitz, M.; Schoenen, S.; Schöneberg, S.; Schönwald, A.; Schukraft, A.; Schulte, L.; Schulz, O.; Seckel, D.; Sestayo, Y.; Seunarine, S.; Shanidze, R.; Sheremata, C.; Smith, M. W. E.; Soldin, D.; Spiczak, G. M.; Spiering, C.; Stamatikos, M.; Stanev, T.; Stanisha, N. A.; Stasik, A.; Stezelberger, T.; Stokstad, R. G.; Stößl, A.; Strahler, E. A.; Ström, R.; Strotjohann, N. L.; Sullivan, G. W.; Taavola, H.; Taboada, I.; Tamburro, A.; Tepe, A.; Ter-Antonyan, S.; Tešić, G.; Tilav, S.; Toale, P. A.; Tobin, M. N.; Toscano, S.; Tselengidou, M.; Unger, E.; Usner, M.; Vallecorsa, S.; van Eijndhoven, N.; Van Overloop, A.; van Santen, J.; Vehring, M.; Voge, M.; Vraeghe, M.; Walck, C.; Waldenmaier, T.; Wallraff, M.; Weaver, Ch.; Wellons, M.; Wendt, C.; Westerhoff, S.; Whelan, B.; Whitehorn, N.; Wiebe, K.; Wiebusch, C. H.; Williams, D. R.; Wissing, H.; Wolf, M.; Wood, T. R.; Woschnagg, K.; Xu, D. L.; Xu, X. W.; Yanez, J. P.; Yodh, G.; Yoshida, S.; Zarzhitsky, P.; Ziemann, J.; Zierke, S.; Zoll, M.; IceCube Collaboration

    2014-05-01

    We report on the search for neutrino-induced particle showers, so-called cascades, in the IceCube-40 detector. The data for this search were collected between April 2008 and May 2009 when the first 40 IceCube strings were deployed and operational. Three complementary searches were performed, each optimized for different energy regimes. The analysis with the lowest energy threshold (2 TeV) targeted atmospheric neutrinos. A total of 67 events were found, consistent with the expectation of 41 atmospheric muons and 30 atmospheric neutrino events. The two other analyses targeted a harder, astrophysical neutrino flux. The analysis with an intermediate threshold of 25 TeV leads to the observation of 14 cascadelike events, again consistent with the prediction of 3.0 atmospheric neutrino and 7.7 atmospheric muon events. We hence set an upper limit of E2Φlim≤7.46×10-8 GeV sr-1 s-1 cm-2 (90% C.L.) on the diffuse flux from astrophysical neutrinos of all neutrino flavors, applicable to the energy range 25 TeV to 5 PeV, assuming an Eν-2 spectrum and a neutrino flavor ratio of 1∶1∶1 at the Earth. The third analysis utilized a larger and optimized sample of atmospheric muon background simulation, leading to a higher energy threshold of 100 TeV. Three events were found over a background prediction of 0.04 atmospheric muon events and 0.21 events from the flux of conventional and prompt atmospheric neutrinos. Including systematic errors this corresponds to a 2.7σ excess with respect to the background-only hypothesis. Our observation of neutrino event candidates above 100 TeV complements IceCube's recently observed evidence for high-energy astrophysical neutrinos.

  14. Association between meteor showers and asteroids using multivariate criteria

    Science.gov (United States)

    Dumitru, B. A.; Birlan, M.; Popescu, M.; Nedelcu, D. A.

    2017-10-01

    Context. Meteoroid streams are fragments of matter produced by comets or asteroids which intersects the orbit of Earth. Meteor showers are produced when Earth intersects these streams of matter. The discoveries of active asteroids and extinct comets open a new view of the relation between these objects as possible parent bodies at the origin of meteor showers. Aims: The aim of this work is to identify the asteroids that can produce or re-populate meteoroid streams by determining the similarity of their orbits and orbital evolution over 10 000 yr. Methods: The identification was carried out by evaluating several well known D-criteria metrics, the orbits being taken from the IAU Meteor Data Center database and from IAU Minor Planet Center. Finally, we analyzed the physical properties and the orbital stability (in the Lyapunov time sense) of the candidates as well as their possible relationship with meteorites. Results: 206 near-Earth asteroids (NEAs) were associated as possible parent bodies with 28 meteor showers, according to at least two of the criterion used. 50 of them satisfied all the criteria. Notable finds are: binary asteroid 2000UG11 associated with Andromedids (AND), while the tumbling asteroid (4179)Toutatis could be associated with October Capricornids (OCC). Other possible good candidates are 2004TG10, 2008EY5, 2010CF55, 2010TU149 and 2014OY1. These objects have low albedo, therefore can be primitive objects. Asteroid 2007LW19 which is a fast rotator and most probably has monolithic structure and so its physical characteristic does not support the association found based on the dynamical criteria.

  15. Merging weak and QCD showers with matrix elements

    Energy Technology Data Exchange (ETDEWEB)

    Christiansen, Jesper Roy [Lund University, Department of Astronomy and Theoretical Physics, Lund (Sweden); Prestel, Stefan [SLAC National Accelerator Laboratory, Menlo Park, CA (United States)

    2016-01-15

    We present a consistent way of combining associated weak boson radiation in hard dijet events with hard QCD radiation in Drell-Yan-like scatterings. This integrates multiple tree-level calculations with vastly different cross sections, QCD- and electroweak parton-shower resummation into a single framework. The new merging strategy is implemented in the Pythia event generator and predictions are confronted with LHC data. Improvements over the previous strategy are observed. Results of the new electroweak-improved merging at a future 100 TeV proton collider are also investigated. (orig.)

  16. Results of Lunar Impact Observations During Geminid Meteor Shower Events

    Science.gov (United States)

    Suggs, R. J.; Suggs, R. M.

    2015-01-01

    the lunar environment associated with larger lunar impactors, but also provides statistical data for verification and improving meteoroid prediction models. Current meteoroid models indicate that the Moon is struck by a sporadic meteoroid with a mass greater than 1 kg over 260 times per year. This number is very uncertain since observations for objects in this mass range are few. Factors of several times, higher or lower, are easily possible. Meteor showers are also present to varying degrees at certain times of the year. The Earth experiences meteor showers when encountering the debris left behind by comets, which is also the case with 2 the Moon. During such times, the rate of shower meteoroids can greatly exceed that of the sporadic background rate for larger meteoroids. Looking for meteor shower impacts on the Moon at about the same time as they occur on Earth will yield important data that can be fed into meteor shower forecasting models, which can then be used to predict times of greater meteoroid hazard on the Moon. The Geminids are one such meteor shower of interest. The Geminids are a major meteor shower that occur in December with a peak intensity occurring usually during the 13th and 14th of the month and appearing to come from a radiant in the constellation Gemini. The Geminids are interesting in that the parent body of the debris stream is an asteroid, which along with the Quadrantids, are the only major meteor showers not originating from a comet. The Geminids parent body, 3200 Phaethon, is about 5 km in diameter and has an orbit that has a 22deg inclination which intersects the main asteroid belt and has a perihelion less than half of Mercury's perihelion distance. Thus, its orbit crosses those of Mars, Earth, Venus, and Mercury. The Geminid debris stream is by far the most massive as compared to the others. When the Earth passes through the stream in mid-December, a peak intensity of approx. equal 120 meteors per hour can be seen. Because of the

  17. The 2011 Draconid Shower Risk to Earth-Orbiting Satellites

    Science.gov (United States)

    Cooke, William J.; Moser, Danielle E.

    2010-01-01

    Current meteor shower forecast models project a strong Draconid outburst, possibly a storm, on October 8, 2011, with a duration of approximately 7 hours and peaking between 19 and 21 hours UT. Predicted rates span an order of magnitude, with maximum Zenithal Hourly Rates (ZHRs) ranging from a few tens to several hundred. Calibration of the NASA MSFC Meteoroid Stream Model 1 to radar and optical observations of past apparitions, particularly the 2005 Draconid outburst 2, suggest that the maximum rate will be several hundreds per hour. Given the high spatial density of the Draconid stream, this implies a maximum meteoroid flux of 5-10 Draconids km(exp -2)/hr (to a limiting diameter of 1 mm), some 25-50 times greater than the normal sporadic flux of 0.2 km(exp -2)/ hr for particles of this size. Total outburst fluence, assuming a maximum ZHR of 750, is 15.5 Draconids km(exp -2), resulting in an overall 10x risk increase to spacecraft surfaces vulnerable to hypervelocity impacts by 1 mm particles. It is now established that a significant fraction of spacecraft anomalies produced by shower meteoroids (e.g. OLYMPUS and LandSat 5) are caused by electrostatic discharges produced by meteoroid impacts. In these cases, the charge generated is roughly proportional to v(exp 3.5(4)), giving a Draconid moving at 20 km/s approximately 1/80th the electrical damage potential of a Leonid of the same mass. In other words, a Draconid outburst with a maximum ZHR of 800 presents the same electrical risk as a normal Leonid shower with a ZHR of 15, assuming the mass indices and shower durations are the same. This is supported by the fact that no spacecraft electrical anomalies were reported during the strong Draconid outbursts of 1985 and 1998. However, the lack of past anomalies should not be taken as carte blanche for satellite operators to ignore the 2011 Draconids, as the upcoming outburst will constitute a period of enhanced risk for vehicles in near-Earth space. Each spacecrft is

  18. Dipole showers and automated NLO matching in Herwig++

    International Nuclear Information System (INIS)

    Plaetzer, Simon; Gieseke, Stefan

    2011-09-01

    We report on the implementation of a coherent dipole shower algorithm along with an automated implementation for dipole subtraction and for performing POWHEG- and MC rate at NLO-type matching to next-to-leading order (NLO) calculations. Both programs are implemented as add-on modules to the event generator HERWIG++. A preliminary tune of parameters to data acquired at LEP, HERA and Drell-Yan pair production at the Tevatron has been performed, and we find an overall very good description which is slightly improved by the NLO matching. (orig.)

  19. Multiplicity distributions in QCD cascades

    International Nuclear Information System (INIS)

    Gustafson, G.

    1992-03-01

    Multiplicity distributions for hadrons and for jets are studied in QCD parton cascades. The colour dipole formalism is used and earlier results in the double log approximation are generalized to include terms which are suppressed by colour factors or factors of ln s. The result is a set of coupled differential equations, together with appropriate boundary conditions

  20. Azobenzene-functionalized cascade molecules

    DEFF Research Database (Denmark)

    Archut, A.; Vogtle, F.; De Cola, L.

    1998-01-01

    Cascade molecules bearing up to 32 azobenzene groups in the periphery have been prepared from poly(propylene imine) dendrimers and N-hydroxysuccinimide esters. The dendritic azobenzene species show similar isomerization properties as the corresponding azobenzene monomers. The all-E azobenzene...

  1. CASCADE: Introducing AI into CBT.

    Science.gov (United States)

    Hendley, R. J.; Jurascheck, N.

    1992-01-01

    Discusses changes in training requirements of commerce and industry in the United Kingdom and describes a project, CASCADE, that was developed to investigate and implement the introduction of artificial intelligence (AI) techniques into computer-based training (CBT). An overview of pilot projects in higher education settings is provided. (eight…

  2. Cascade Support Vector Machines with Dimensionality Reduction

    Directory of Open Access Journals (Sweden)

    Oliver Kramer

    2015-01-01

    Full Text Available Cascade support vector machines have been introduced as extension of classic support vector machines that allow a fast training on large data sets. In this work, we combine cascade support vector machines with dimensionality reduction based preprocessing. The cascade principle allows fast learning based on the division of the training set into subsets and the union of cascade learning results based on support vectors in each cascade level. The combination with dimensionality reduction as preprocessing results in a significant speedup, often without loss of classifier accuracies, while considering the high-dimensional pendants of the low-dimensional support vectors in each new cascade level. We analyze and compare various instantiations of dimensionality reduction preprocessing and cascade SVMs with principal component analysis, locally linear embedding, and isometric mapping. The experimental analysis on various artificial and real-world benchmark problems includes various cascade specific parameters like intermediate training set sizes and dimensionalities.

  3. Computer simulation of displacement cascades in copper

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1983-06-01

    More than 500 displacement cascades in copper have been generated with the computer simulation code MARLOWE over an energy range pertinent to both fission and fusion neutron spectra. Three-dimensional graphical depictions of selected cascades, as well as quantitative analysis of cascade shapes and sizes and defect densities, illustrate cascade behavior as a function of energy. With increasing energy, the transition from production of single compact damage regions to widely spaced multiple damage regions is clearly demonstrated

  4. Monte-Carlo simulation of hadronic showers. Part 1: Comparison with experiment

    International Nuclear Information System (INIS)

    Amatuni, Ts.A.; Mamidjanyan, E.A.; Sanossyan, Kh.N.

    1992-01-01

    Hadronic showers are simulated by the MARS 10 code and compared with various experimental results obtained at high-energy accelerators. Good agreement between the experiment and the simulations is observed. MARS 10 is a fast and reliable instrument for numerical studies of the average characteristics of hadronic showers. 16 refs

  5. The applications of neural networks in the core location analysis of extensive air showers

    International Nuclear Information System (INIS)

    Perrett, J.C.; Stekelenborg, J.T.P.M. van

    1991-01-01

    We describe the teaching and implementation of a neural network to estimate the core position and energy of extensive air showers recorded by the South Pole air shower experiment, SPASE. The neural network was found to be approximately 300 times faster than the traditional χ 2 minimization technique previously used and as accurate. (Author)

  6. Probing Atmospheric Electric Fields through Radio Emission from Cosmic-Ray-Induced Air Showers

    NARCIS (Netherlands)

    Scholten, Olaf; Trinh, Gia; Buitink, Stijn; Corstanje, Arthur; Ebert, Ute; Enriquez, Emilio; Falcke, Heino; Hoerandel, Joerg; Nelles, Anna; Schellart, Pim; Rachen, Joerg; Rutjes, Casper; ter Veen, Sander; Rossetto, Laura; Thoudam, Satyendra

    2016-01-01

    Energetic cosmic rays impinging on the atmosphere create a particle avalanche called an extensive air shower. In the leading plasma of this shower electric currents are induced that generate coherent radio wave emission that has been detected with LOFAR, a large and dense array of simple radio

  7. Muons in air showers at the Pierre Auger Observatory : Measurement of atmospheric production depth

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahlers, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, F.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Cheng, S. H.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Coutu, S.; Covault, C. E.; Criss, A.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Diaz Castro, M. L.; Diep, P. N.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dong, P. N.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fox, B. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Bravo, A. Gascon; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Albarracin, F. Gomez; Berisso, M. Gomez; Vitale, P. F. Gomez; Goncalves, P.; Gonzalez, J. G.; Gookin, B.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hansen, P.; Harari, D.; Harrison, T. A.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Horandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; La Rosa, G.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui De Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Lyberis, H.; Maccarone, M. C.; Malacari, M.; Maldera, S.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Meza, J. J. Masias; Mathes, H. J.; Mathys, S.; Matthews, A. J.; Matthews, J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menichetti, E.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Moreno, J. C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Ortiz, M.; Pacheco, N.; Selmi-Dei, D. Pakk; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Pastor, S.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Pesce, R.; Petermann, E.; Peters, C.; Petrera, S.; Petrolini, A.; Petrov, Y.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rojo, J. Rodriguez; Rodriguez-Frias, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Ruehle, C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, A.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schulz, A.; Schulz, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Thao, N. T.; Theodoro, V. M.; Tiffenberg, J.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Machado, D. Torres; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Whelan, B. J.; Widom, A.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Silva, M. Zimbres; Ziolkowski, M.

    2014-01-01

    The surface detector array of the Pierre Auger Observatory provides information about the longitudinal development of the muonic component of extensive air showers. Using the timing information from the flash analog-to-digital converter traces of surface detectors far from the shower core, it is

  8. Methicillin-Resistant Staphylococcus aureus in Pork Production Shower Facilities ▿

    Science.gov (United States)

    Leedom Larson, Kerry R.; Harper, Abby L.; Hanson, Blake M.; Male, Michael J.; Wardyn, Shylo E.; Dressler, Anne E.; Wagstrom, Elizabeth A.; Tendolkar, Shaliesh; Diekema, Daniel J.; Donham, Kelley J.; Smith, Tara C.

    2011-01-01

    As methicillin-resistant Staphylococcus aureus (MRSA) has been found in pigs, we sought to determine if MRSA is present in pork production shower facilities. In two production systems tested, 3% and 26% of shower samples were positive for MRSA. spa types identified included t034, t189, t753, and t1746. PMID:21097587

  9. Testing usability of Mobile Shower Commodes for adults with Spinal Cord Injury: research method and overview.

    Science.gov (United States)

    Friesen, Emma L; Russell, Trevor G; Theodoros, Deborah

    2015-01-01

    This paper provides an overview of research to develop a new questionnaire testing mobile shower commode usability. It describes the methodology used to develop the questionnaire, and reports significant findings that have been published in peer-reviewed journals. Implications of the research and recommendations for further research on mobile shower commode usability are discussed.

  10. Parton-shower matching systematics in vector-boson-fusion WW production

    Energy Technology Data Exchange (ETDEWEB)

    Rauch, Michael [Karlsruhe Institute of Technology, Institute for Theoretical Physics, Karlsruhe (Germany); Plaetzer, Simon [Durham University, Institute for Particle Physics Phenomenology, Durham (United Kingdom); University of Manchester, School of Physics and Astronomy, Manchester (United Kingdom)

    2017-05-15

    We perform a detailed analysis of next-to-leading order plus parton-shower matching in vector-boson-fusion WW production including leptonic decays. The study is performed in the Herwig 7 framework interfaced to VBFNLO 3, using the angular-ordered and dipole-based parton-shower algorithms combined with the subtractive and multiplicative-matching algorithms. (orig.)

  11. The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial

    NARCIS (Netherlands)

    Buijze, Geert A.; Sierevelt, Inger N.; van der Heijden, Bas C. J. M.; Dijkgraaf, Marcel G.; Frings-Dresen, Monique H. W.

    2016-01-01

    The aim of this study was to determine the cumulative effect of a routine (hot-to-) cold shower on sickness, quality of life and work productivity. Between January and March 2015, 3018 participants between 18 and 65 years without severe comorbidity and no routine experience of cold showering were

  12. Determining Thunderstorm Electric Fields using Radio Emission from Cosmic-Ray Air Showers

    NARCIS (Netherlands)

    Hare, B.; Scholten, O.; Trinh, G. T. N.; Ebert, U.; Rutjes, C.

    2017-01-01

    We report on a novel non-intrusive way to investigate electric fields in thunderclouds.Energetic cosmic rays penetrating the atmosphere create a particle avalanche called an extensive air shower. The front of the shower is a plasma cloud that contains 10^6 or more free electrons and positrons moving

  13. Performance of D-Parameters in Isolating Meteor Showers from the Sporadic Background

    Science.gov (United States)

    Moorhead, Althea

    2016-01-01

    It is often necessary to draw a division between meteor showers and the sporadic meteor complex in order to study these components of the meteoroid environment. Meteor showers persist for less than a season and are composed of members with a greater-than-average degree of orbital similarity. The level of orbital similarity is often quantified using so-called D-parameters; a D-parameter cutoff may be employed to define or extract a shower. Depending on the study, this cutoff value may be chosen based on the size of the data-set, the percentage of sporadic meteors within the data-set, or the inclination of the shower in question. We argue that the cutoff value should also reject the strength of the shower compared to the local sporadic background. We therefore present a method for determining, on a per-shower basis, the D-parameter cutoff that limits the false-positive rate to an acceptable percentage. If the false-positive rate exceeds this percentage regardless of cutoff value, we deem the shower to be undetectable in our data. We apply this method to optical meteor observations from the NASA All-Sky and Southern Ontario Meteor Networks and present the detectable meteor showers and their characteristics.

  14. Cascaded Bragg scattering in fiber optics.

    Science.gov (United States)

    Xu, Y Q; Erkintalo, M; Genty, G; Murdoch, S G

    2013-01-15

    We report on a theoretical and experimental study of cascaded Bragg scattering in fiber optics. We show that the usual energy-momentum conservation of Bragg scattering can be considerably relaxed via cascade-induced phase-matching. Experimentally we demonstrate frequency translation over six- and 11-fold cascades, in excellent agreement with derived phase-matching conditions.

  15. Assessment of emergency safety showers against proposed EU and ANSI standards

    Directory of Open Access Journals (Sweden)

    M Burby

    2008-09-01

    Full Text Available This investigation was carried out with the cooperation of a majorinternational safety shower manufacturer, Hughes Safety Showers Ltd. Thefirst part of this study was to characterise various commercial safetyshower heads with regard to their spray patternation, droplet sizes, dropletvelocities and impact forces. The spray patternation of a number of showerhead designs were compared against the proposed EU and AmericanNational Standard institute (ANSI standard for plumbed in body showers.The results of this work showed that a large proportion of the shower headdeigns failed to meet the proposed EU standard. The second part to thisstudy was to determine the efficiency and effectiveness of the emergencysafety shower head designs via a series of decontamination ‘wash-off’tests on a mannequin, with a number of simulated hazardous substancesapplied to its surface.

  16. Arrival-time distribution of air-shower electrons near the core

    International Nuclear Information System (INIS)

    Inoue, N.; Toyoda, Y.; Maeda, T.; Kawamoto, M.; Shigeta, M.; Kihara, K.

    1989-01-01

    The longitudinal structure of air-shower discs has been studied by measuring the arrival-time distribution of electrons in air showers with sizes 10 5.5 to 10 7.5 , at distances less than 75 m from the core, in the Akeno air-shower array (900 m above sea level). The average T 10-80 , the time between arrival of 10% and 80% of the integrated full signal, which corresponds to the thickness of the air-shower disc, is found to increase with core distance from about 2 ns at less than 10 m to 13 ns at 70 m. Any dependence on shower size, age parameter or zenith angle cannot be seen at the small core distance observed. An empirical formula for the arrival-time distribution as a function of core distances is given. (author)

  17. Reconstruction of inclined shower coordinates in electromagnetic calorimeters based on lead glass

    International Nuclear Information System (INIS)

    Vasil'ev, A.N.; Mochalov, V.V.; Solov'ev, L.F.

    2007-01-01

    A method for reconstructing the coordinates of inclined showers in lead glass electromagnetic calorimeters is described. Such showers are generated by photons with energies of 0.5-4.0 GeV that are incident on the detector at angles of as great as 30 deg. An analytical expression for the description of the actual photon coordinate in the calorimeter versus the coordinates of the shower center of gravity is proposed. Using this expression, it is possible to reconstruct the coordinates of inclined electromagnetic showers over wide ranges of angles and energies. The dependences of the spatial resolution on the photon energy and angle are determined. The longitudinal fluctuations of the shower length and their effect on the spatial resolution of the calorimeter are discussed [ru

  18. A deep learning-based reconstruction of cosmic ray-induced air showers

    Science.gov (United States)

    Erdmann, M.; Glombitza, J.; Walz, D.

    2018-01-01

    We describe a method of reconstructing air showers induced by cosmic rays using deep learning techniques. We simulate an observatory consisting of ground-based particle detectors with fixed locations on a regular grid. The detector's responses to traversing shower particles are signal amplitudes as a function of time, which provide information on transverse and longitudinal shower properties. In order to take advantage of convolutional network techniques specialized in local pattern recognition, we convert all information to the image-like grid of the detectors. In this way, multiple features, such as arrival times of the first particles and optimized characterizations of time traces, are processed by the network. The reconstruction quality of the cosmic ray arrival direction turns out to be competitive with an analytic reconstruction algorithm. The reconstructed shower direction, energy and shower depth show the expected improvement in resolution for higher cosmic ray energy.

  19. Meteor Shower Forecast Improvements from a Survey of All-Sky Network Observations

    Science.gov (United States)

    Moorhead, Althea V.; Sugar, Glenn; Brown, Peter G.; Cooke, William J.

    2015-01-01

    Meteoroid impacts are capable of damaging spacecraft and potentially ending missions. In order to help spacecraft programs mitigate these risks, NASA's Meteoroid Environment Office (MEO) monitors and predicts meteoroid activity. Temporal variations in near-Earth space are described by the MEO's annual meteor shower forecast, which is based on both past shower activity and model predictions. The MEO and the University of Western Ontario operate sister networks of all-sky meteor cameras. These networks have been in operation for more than 7 years and have computed more than 20,000 meteor orbits. Using these data, we conduct a survey of meteor shower activity in the "fireball" size regime using DBSCAN. For each shower detected in our survey, we compute the date of peak activity and characterize the growth and decay of the shower's activity before and after the peak. These parameters are then incorporated into the annual forecast for an improved treatment of annual activity.

  20. Parton shower and NLO-matching uncertainties in Higgs boson pair production

    Science.gov (United States)

    Jones, Stephen; Kuttimalai, Silvan

    2018-02-01

    We perform a detailed study of NLO parton shower matching uncertainties in Higgs boson pair production through gluon fusion at the LHC based on a generic and process independent implementation of NLO subtraction and parton shower matching schemes for loop-induced processes in the Sherpa event generator. We take into account the full top-quark mass dependence in the two-loop virtual corrections and compare the results to an effective theory approximation. In the full calculation, our findings suggest large parton shower matching uncertainties that are absent in the effective theory approximation. We observe large uncertainties even in regions of phase space where fixed-order calculations are theoretically well motivated and parton shower effects expected to be small. We compare our results to NLO matched parton shower simulations and analytic resummation results that are available in the literature.

  1. The distribution of time intervals between cosmic ray showers -a study of the randomness of cosmic ray arrival times

    International Nuclear Information System (INIS)

    Clay, R.W.; Gerhardy, P.R.

    1980-01-01

    It has recently been reported that cosmic ray showers arrive in an appreciably nonrandom manner with an excessive number of short time intervals between showers. The authors have investigated the distribution of time intervals between showers of size Nsub(e) approximately > 10 5 and find that if there is any excess of short intervals it must be approximately < 5%

  2. Gamma-rays from dark showers with twin Higgs models

    Energy Technology Data Exchange (ETDEWEB)

    Freytsis, Marat [Institute of Theoretical Science, University of Oregon,Eugene, OR 97403 (United States); Knapen, Simon; Robinson, Dean J. [Department of Physics, University of California,Berkeley, CA 94720 (United States); Ernest Orlando Lawrence Berkeley National Laboratory,University of California, Berkeley, CA 94720 (United States); Tsai, Yuhsin [Maryland Center for Fundamental Physics, Department of Physics,University of Maryland, College Park, MD 20742 (United States)

    2016-05-03

    We consider a twin WIMP scenario whose twin sector contains a full dark copy of the SM hadrons, where the lightest twin particles are twin pions. By analogy to the standard WIMP paradigm, the dark matter (DM) freezes out through twin electroweak interactions, and annihilates into a dark shower of light twin hadrons. These are either stable or decay predominantly to standard model (SM) photons. We show that this ‘hadrosymmetric’ scenario can be consistent with all applicable astrophysical, cosmological and collider constraints. In order to decay the twin hadrons before the big-bang nucleosynthesis epoch, an additional portal between the SM and twin sector is required. In most cases we find this additional mediator is within reach of either the LHC or future intensity frontier experiments. Furthermore, we conduct simulations of the dark shower and consequent photon spectra. We find that fits of these spectra to the claimed galactic center gamma-ray excess seen by Fermi-LAT non-trivially coincide with regions of parameter space that both successfully generate the observed DM abundance and exhibit minimal fine-tuning.

  3. Lunar Impact Detections During the 2010 Geminid Meteor Shower

    Science.gov (United States)

    Suggs, Ron; Suggs, Rob; Moser, Danielle; Blaauw, Rhiannon

    2011-01-01

    Lunar video observations are routinely conducted at the NASA Marshall Space Flight Center in Huntsville Alabama for the detection of meteoroid impacts. Over 240 impacts have been detected since the start of the observing program initiated approximately 5 years ago. During this time it has been fairly rare that lunar observing conditions and the weather have been favorable during the peak of the major showers. However, observing conditions were marginally favorable during the peak of the 2010 Geminids. On Dec. 14, 2010 approximately 5.5 hours of video were recorded. Even though the lunar phase was just outside the constraints established for optimum lunar impact monitoring, the resulting video was of sufficient quality that 21 lunar impacts were detected yielding an average impact rate of approximately 4 per hour. This compares to 17 lunar impacts detected over 40 nights of observations ( approximately 100 hours of lunar video) yielding an average impact rate of 1 per 6 hours for the whole of 2010, excluding Dec. 14. The results of the 2010 Geminid lunar impact detections will be discussed along with previous results from the 2006 Geminid shower that also coincided within the lunar observing window.

  4. Forward shower counters for diffractive physics at the LHC

    Science.gov (United States)

    Albrow, Michael; Collins, Paula; Penzo, Aldo

    2014-11-01

    The LHC detectors have incomplete angular coverage in the forward direction, for example in the region 6 ≲ |η| ≲ 8, which can be improved with the addition of simple scintillation counters around the beam pipes about 50 m to 120 m from the intersection point. These counters detect showers created by particles hitting the beam pipes and nearby material. The absence of signals in these counters in low pileup conditions is an indication of a forward rapidity gap as a signature of diffraction. In addition, they can be used to detect hadrons from low mass diffractive excitations of the proton, not accompanied by a leading proton but adjacent to a rapidity gap over (e.g.) 3 ≲ |η| ≲ 6. Such a set of forward shower counters, originally used at CDF, was used in CMS (FSC) for high-β* running with TOTEM during LHC Run-1. During LS1 the CMS FSC system is being upgraded for future low pileup runs. A similar system, called HERSCHEL is being installed in LHCb. ALICE is implementing scintillation counters, ADA and ADC, with 4.5 ≲ |η| ≲ 6.4.

  5. The arrival time distribution of muons in extensive air showers

    International Nuclear Information System (INIS)

    Van der Walt, D.J.

    1984-01-01

    An experiment was done to investigate the lateral dependence of the muon arrival time distribution in extensive air showers at small core distances. In the present experiment the muon arrival time distribution was investigated by measuring the relative arrival times between single muons in five fast Cerenkov detectors beneath 500g/cm 2 of concrete and at an atmospheric depth of 880g/cm 2 . It is shown that, although it is not possible to determine the arrival time distribution as such, it is possible to interpret the relative arrival times between muons in terms of the differences between the order statistics of a sample drawn from the arrival time distribution. The relationship between the arrival time distribution of muons relative to the first detected muon and the muon arrival time distribution is also derived. It was found that the dispersion of the muon arrival time distribution does not increase significantly with increasing core distance between 10m and 60m from the core. A comparison with theoretical distributions obtained from model calculations for proton initiated showers indicate that 1. the mean delay of muons with respect to the first detected muon is significantly larger than that expected from the model and 2. the observed dispersion is also significantly larger than the predicted dispersion for core distances between 10m and 60m

  6. Further investigation on the performance of a shower cooling tower

    International Nuclear Information System (INIS)

    Qi Xiaoni; Liu Zhenyan

    2008-01-01

    This study was prompted by the need to design towers for applications in which, due to salt deposition on the packing and subsequent blockage, the use of tower packing is not practical. In the previous model we presented [Qi Xiaoni, Liu Zhenyan, Li Dandan. Performance characteristics of a shower cooling tower. Energy Convers Manage 2007;48(1):193-203.], three critical assumptions were made to reduce the complexity and computational time, which can also reduce the models' accuracy. Accurate modelling of the operating process is a determining factor both for designing the shower cooling tower (SCT) and for optimising its operation. In this paper, we derive a new model without applying the three assumptions. According to the condition of the outlet air, the governing equations consider two cases, including the supersaturated and unsaturated states. This model is used to predict the performance of a full scale SCT located in China with different conditions for validation. The differences in the heat and mass transfer analyses of the two models are described at different atmospheric conditions

  7. Martian Atmospheric Methane Plumes from Meteor Shower Infall: A Hypothesis

    Science.gov (United States)

    Fries, M.; Christou, A.; Archer, D.; Conrad, P.; Cooke, W.; Eigenbrode, J.; ten Kate, I. L.; Matney, M.; Niles, P.; Sykes, M.

    2016-01-01

    Methane plumes in the martian atmosphere have been detected using Earth-based spectroscopy, the Planetary Fourier Spectrometer on the ESA Mars Express mission, and the NASA Mars Science Laboratory. The methane's origin remains a mystery, with proposed sources including volcanism, exogenous sources like impacts and interplanetary dust, aqueous alteration of olivine in the presence of carbonaceous material, release from ancient deposits of methane clathrates, and/or biological activity. To date, none of these phenomena have been found to reliably correlate with the detection of methane plumes. An additional source exists, however: meteor showers could generate martian methane via UV pyrolysis of carbon-rich infall material. We find a correlation between the dates of Mars/cometary orbit encounters and detections of methane on Mars. We hypothesize that cometary debris falls onto Mars during these interactions, depositing freshly disaggregated meteor shower material in a regional concentration. The material generates methane via UV photolysis, resulting in a localized "plume" of short-lived methane.

  8. Simulation of a microwave antenna with extended field of view for the detection of molecular Bremsstrahlung emitted by extensive air showers

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Andre Ramos de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola Politecnica; Bonifazi, Carla; Santos, Edivaldo Moura; Soares, Elvis do Amaral; Mello Neto, Joao Ramos Torres de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica; Almeida, Rogerio Menezes de [Universidade Federal Fluminense (EEIMVR/UFF), Volta Redonda, RJ (Brazil). Escola de Engenharia Industrial Metalurgica de Volta Redonda

    2011-07-01

    Full text: The MIDAS (Microwave Detection of Air Showers) Collaboration is an R and D effort for the detection of Extensive Air Showers in the frequency range of microwaves. It is believed that a large amount of the atmospheric cascade energy is released in the form of electromagnetic radiation in the radio/microwave domain, due to the continuous energy loss by electrons as they collide with atmospheric neutral nitrogen (and less frequently oxygen) molecules. An apparatus developed at the University of Chicago has been constructed in order to test the feasibility of the technique. It contains a parabolic reflector illuminating a multi-pixel camera of commercial TV satellite C-band (3.4-4.2 GHz) feeds. We describe here the simulation pipe (written in C++) developed at the Universidade Federal do Rio de Janeiro (UFRJ) of the experimental apparatus mentioned. The angular resolution, directional response and frequency dependency of the main detector signals are simulated and compared with absolute calibration data performed with standard radio sources, such as the Sun, the Moon and the Crab Nebula, as well as relative calibration with a reference emitting antenna. Finally, optimization studies for the experimental apparatus were performed, such as determining the best reflectors size and focal length, operation frequency and several other parameters of the detector. (author)

  9. Cascade Chaotic System With Applications.

    Science.gov (United States)

    Zhou, Yicong; Hua, Zhongyun; Pun, Chi-Man; Chen, C L Philip

    2015-09-01

    Chaotic maps are widely used in different applications. Motivated by the cascade structure in electronic circuits, this paper introduces a general chaotic framework called the cascade chaotic system (CCS). Using two 1-D chaotic maps as seed maps, CCS is able to generate a huge number of new chaotic maps. Examples and evaluations show the CCS's robustness. Compared with corresponding seed maps, newly generated chaotic maps are more unpredictable and have better chaotic performance, more parameters, and complex chaotic properties. To investigate applications of CCS, we introduce a pseudo-random number generator (PRNG) and a data encryption system using a chaotic map generated by CCS. Simulation and analysis demonstrate that the proposed PRNG has high quality of randomness and that the data encryption system is able to protect different types of data with a high-security level.

  10. Bankruptcy cascades in interbank markets.

    Directory of Open Access Journals (Sweden)

    Gabriele Tedeschi

    Full Text Available We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  11. Bankruptcy cascades in interbank markets.

    Science.gov (United States)

    Tedeschi, Gabriele; Mazloumian, Amin; Gallegati, Mauro; Helbing, Dirk

    2012-01-01

    We study a credit network and, in particular, an interbank system with an agent-based model. To understand the relationship between business cycles and cascades of bankruptcies, we model a three-sector economy with goods, credit and interbank market. In the interbank market, the participating banks share the risk of bad debits, which may potentially spread a bank's liquidity problems through the network of banks. Our agent-based model sheds light on the correlation between bankruptcy cascades and the endogenous economic cycle of booms and recessions. It also demonstrates the serious trade-off between, on the one hand, reducing risks of individual banks by sharing them and, on the other hand, creating systemic risks through credit-related interlinkages of banks. As a result of our study, the dynamics underlying the meltdown of financial markets in 2008 becomes much better understandable.

  12. Atom-atom collision cascades localization

    International Nuclear Information System (INIS)

    Kirsanov, V.V.

    1980-01-01

    The presence of an impurity and thermal vibration influence on the atom-atom collision cascade development is analysed by the computer simulation method (the modificated dynamic model). It is discovered that the relatively low energetic cascades are localized with the temperature increase of an irradiated crystal. On the basis of the given effect the mechanism of splitting of the high energetic cascades into subcascades is proposed. It accounts for two factors: the primary knocked atom energy and the irradiated crystal temperature. Introduction of an impurity also localizes the cascades independently from the impurity atom mass. The cascades localization leads to intensification of the process of annealing in the cascades and reduction of the post-cascade vacancy cluster sizes. (author)

  13. Analytic solutions of QCD evolution equations for parton cascades inside nuclear matter at small x

    International Nuclear Information System (INIS)

    Geiger, K.

    1994-01-01

    An analytical method is presented to solve generalized QCD evolution equations for the time development of parton cascades in a nuclear environment. In addition to the usual parton branching processes in vacuum, these evolution equations provide a consistent description of interactions with the nuclear medium by accounting for stimulated branching processes, fusion, and scattering processes that are specific to QCD in a medium. Closed solutions for the spectra of produced partons with respect to the variables time, longitudinal momentum, and virtuality are obtained under some idealizing assumptions about the composition of the nuclear medium. Several characteristic features of the resulting parton distributions are discussed. One of the main conclusions is that the evolution of a parton shower in a medium is dilated as compared to free space and is accompanied by an enhancement of particle production. These effects become stronger with increasing nuclear density

  14. New graduate occupational therapists experience of showering assessments: a phenomological study.

    Science.gov (United States)

    Glenn, Emma K; Gilbert-Hunt, Susan

    2012-06-01

    Shower assessments are complex and challenging tasks undertaken by many occupational therapists with little known about how they are conducted and how new graduates learn to carry these out. There are no published guidelines and limited opportunity for students to practise shower assessments during their training bringing into question how new graduates learn to do this assessment and judge their effectiveness. To investigate the experience of new graduate occupational therapists undertaking their first shower assessments in South Australia. Six graduate occupational therapists participated in a phenomenological study. Data were gathered through semi-structured interviews and analysed according to Giorgi's descriptive phenomenological method. New graduates found the shower assessment process cognitively and emotionally demanding. Without prior experience, new graduates lacked confidence to perform the practical aspects of conducting a shower assessment. The sense of responsibility for getting it right and ensuring client safety was at times overwhelming. Social norms around nudity, age and gender impacted on the graduate's interaction with clients in the shower environment. However, graduates with previous care attendant work were better able to manage the social and practical challenges inherent in shower assessments. The findings of this study suggest that additional experiential, 'hands on', learning is needed in university curriculum for new graduates to develop practical clinical skills, particularly as practice placements have become more diverse. Similarly there is a need for organisations to provide orientation activities and mentoring for new graduates as they transition from student to therapist. © 2012 The Authors Australian Occupational Therapy Journal © 2012 Occupational Therapy Australia.

  15. Search for neutrino-induced cascade events in the icecube detector

    Energy Technology Data Exchange (ETDEWEB)

    Panknin, Sebastian

    2011-09-15

    This thesis presents results of a search for a diffuse flux of high energetic neutrinos from extra-terrestrial origin. Such a flux is predicted by several models of sources of cosmic ray particles. In a neutrino detector, such as IceCube, there are mainly two signatures available for detection of neutrinos: The track-like light signal of a neutrino induced muon and the spherical light pattern of a neutrino induced particle shower, called cascades in this context. The search is based on the measurement of neutrino induced cascades within the IceCube neutrino detector. The data were taken in 2008/2009 with a total uptime of 367 days. At that time the detector was still under construction and had just reached half of its final size. A search for a neutrino flux using cascades is sensitive to all neutrino flavors. A cascade develops within few meters, in contrast to the muon track of several kilometers length. Therefore a good energy reconstruction is possible. With such a reconstruction the astrophysical neutrino flux can be statistically distinguished from the background of atmospheric neutrinos. In the simulation of cascades so far it was not included, that in hadronic cascades muons are produced. This can influence the shape of the cascade, to a less spherical one. Therefore the effect was parameterized in this thesis and included in the simulation. Further cuts on the event topology and reconstructed energy were developed, in order to reduce the background of atmospheric muons and atmospheric neutrinos. Four events from the measured data pass these cuts. Taking the high systematic uncertainties into account, this result is in agreement with the expected background of 0.72{+-}0.28{+-}{sup 1.54}{sub 0.49} events. For an assumed flavor ratio of {nu}{sub e}:{nu}{sub {mu}}:{nu}{sub {tau}}=1:1:1 the upper limit for the all flavor neutrino flux is 9.5.10{sup -8}E{sup -2} GeVs{sup -1}sr{sup -1}cm{sup -2}.

  16. Cascades from nu_E above 1020 eV

    Energy Technology Data Exchange (ETDEWEB)

    Klein, Spencer R.

    2004-12-21

    At very high energies, the Landau-Pomeranchuk-Migdal effect reduces the cross sections for electron bremsstrahlung and photon e{sup +}e{sup -} pair production. The fractional electron energy loss and pair production cross sections drop as the energy increases. In contrast, the cross sections for photonuclear interactions grow with energy. In solids and liquids, at energies above 10{sup 20} eV, photonuclear reactions dominate, and showers that originate as photons or electrons quickly become hadronic showers. These electron-initiated hadronic showers are much shorter (due to the absence of the LPM effect), but wider than purely electromagnetic showers would be. This change in shape alters the spectrum of the electromagnetic and acoustic radiation emitted from the shower. These alterations have important implications for existing and planned searches for radiation from u{sub e} induced showers above 10{sup 20} eV, and some existing limits should be reevaluated.

  17. Prevalence of Legionella species isolated from shower water in public bath facilities in Toyama Prefecture, Japan.

    Science.gov (United States)

    Kanatani, Jun-Ichi; Isobe, Junko; Norimoto, Shiho; Kimata, Keiko; Mitsui, Chieko; Amemura-Maekawa, Junko; Kura, Fumiaki; Sata, Tetsutaro; Watahiki, Masanori

    2017-05-01

    We investigated the prevalence of Legionella spp. isolated from shower water in public bath facilities in Toyama Prefecture, Japan. In addition, we analyzed the genetic diversity among Legionella pneumophila isolates from shower water as well as the genetic relationship between isolates from shower water and from stock strains previously analyzed from sputum specimens. The isolates were characterized using serogrouping, 16S rRNA gene sequencing, and sequence-based typing. Legionella spp. were isolated from 31/91 (34.1%) samples derived from 17/37 (45.9%) bath facilities. Isolates from shower water and bath water in each public bath facility were serologically or genetically different, indicating that we need to isolate several L. pneumophila colonies from both bath and shower water to identify public bath facilities as sources of legionellosis. The 61 L. pneumophila isolates from shower water were classified into 39 sequence types (STs) (index of discrimination = 0.974), including 19 new STs. Among the 39 STs, 12 STs match clinical isolates in the European Working Group for Legionella Infections database. Notably, ST505 L. pneumophila SG 1, a strain frequently isolated from patients with legionellosis and from bath water in this area, was isolated from shower water. Pathogenic L. pneumophila strains including ST505 strain were widely distributed in shower water in public bath facilities, with genetic diversity showing several different origins. This study highlights the need to isolate several L. pneumophila colonies from both bath water and shower water to identify public bath facilities as infection sources in legionellosis cases. Copyright © 2017 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

  18. Reconstruction of extensive air showers and measurement of the cosmic ray energy spectrum in the range of 1 - 80 PeV at the South Pole

    Energy Technology Data Exchange (ETDEWEB)

    Klepser, Stefan

    2008-06-24

    IceTop is a km{sup 2} scale detector array for highly energetic cosmic radiation. It is a part of the IceCube Observatory that is presently being built at the geographic South Pole. It aims for the detection of huge particle cascades induced by PeV cosmic rays in the atmosphere. These extensive air showers are detected by cylindrical ice tanks that collect the Cherenkov light produced by penetrating particles. The main goal of IceTop is the investigation of the energy distribution and chemical composition of PeV to EeV cosmic rays. This thesis presents the first analysis of highly energetic cosmic ray data taken with IceTop. First, the light response of the IceTop tanks is parametrised as a function of energy and particle type. An expectation function for the distribution of shower signals in the detector plane is developed. The likelihood fit based on that can reconstruct the recorded shower events with resolutions of 1.5 in direction, 9m in location of the shower center, and 12% in energy. This is well competitive with other experiments. The resulting energy response of the array is studied to set up response matrices for different primary nuclei and inclinations. These allow for a deconvolution of the distribution of reconstructed energies to derive the real energy spectrum. Two unfolding algorithms are implemented and studied, and response matrices are modeled for four different composition assumptions. With each assumption, energy spectra are unfolded for three different bins in inclination, using a data sample with an exposure of 3.86.10{sup 11} m{sup 2} s sr, taken in August 2007. The range of the spectrum is 1-80 PeV. Finally, a new analysis method is developed that uses the fact that cosmic rays in the PeV range are expected to be isotropic. It is shown that this requirement can be used for a likelihood estimation that is sensitive to composition without using additional information from other detector components. The analysis shows a clear preference of

  19. The Performance of the New LHCf Detector for Hadronic Showers

    Science.gov (United States)

    Ueno, Mana

    The Large Hadron Collider forward (LHCf) experiment is designed to understand the hadronic interaction between cosmic rays and the atmosphere. We have measured neutral particles, photons and neutrons, in very forward region of √{s} = 13 TeV proton-proton collision at CERN-LHC. Before this operation, the LHCf detectors were updated in 2014 by replacing the plastic scintillators with GSO scintillators to improve radiation-hardness. In this paper, we present the performance of the one of the new LHCf detectors for hadronic showers evaluated by a beam test at CERN-SPS and MC simulations. The energy resolution and position resolution are found to be 42% and 0.9 mm, respectively, at the center of the detector for a 350 GeV proton beam. We confirmed the new detector performance is consistent with the performance of the old detector used in the 2010 operation as expected.

  20. Electromagnetic shower properties in a lead-scintillator sampling calorimeter

    Science.gov (United States)

    Kotwal, Ashutosh V.; Hays, Christopher

    2013-11-01

    The Collider Detector at Fermilab (CDF) is a general-purpose experimental apparatus with an inner tracking detector for measuring charged particles, surrounded by a calorimeter for measurements of electromagnetic and hadronic showers. We describe a GEANT4 simulation and parameterization of the response of the CDF central electromagnetic calorimeter (CEM) to incident electrons and photons. The detector model consists of a detailed description of the CEM geometry and material in the direction of the incident particle's trajectory, and of the passive material between the tracker and the CEM. We use GEANT4 to calculate the distributions of: the energy that leaks from the back of the CEM, the energy fraction sampled by the scintillators, and the energy dependence of the response. We parameterize these distributions to accurately model electron and photon response and resolution in a custom simulation for the measurement of the W boson mass.

  1. Ground detectors for the study of cosmic ray showers

    International Nuclear Information System (INIS)

    Salazar, H; Villasenor, L

    2008-01-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the detection of decaying and crossing muons in a water Cherenkov detector and discuss an application of these results to calibrate water Cherenkov detectors. We also describe a technique to separate isolated isolated muons and electrons in water Cherenkov detector. Next we describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19 deg. N, 90 deg. W, 800 g/cm 2 ) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV

  2. Ground detectors for the study of cosmic ray showers

    Energy Technology Data Exchange (ETDEWEB)

    Salazar, H [Facultad de Ciencias Fisico-Matematicas, BUAP, Puebla, Pue., 72000 (Mexico); Villasenor, L [Instituto de Fisica y Matematicas, UMSNH, Morelia, Michoacan, 58040 (Mexico)], E-mail: villasen@ifm.umich.mx

    2008-06-01

    We describe the work that we have done over the last decade to design and construct instruments to measure properties of cosmic rays in Mexico. We describe the detection of decaying and crossing muons in a water Cherenkov detector and discuss an application of these results to calibrate water Cherenkov detectors. We also describe a technique to separate isolated isolated muons and electrons in water Cherenkov detector. Next we describe the design and performance of a hybrid extensive air shower detector array built on the Campus of the University of Puebla (19 deg. N, 90 deg. W, 800 g/cm{sup 2}) to measure the energy, arrival direction and composition of primary cosmic rays with energies around 1 PeV.

  3. Processing method and results of meteor shower radar observations

    International Nuclear Information System (INIS)

    Belkovich, O.I.; Suleimanov, N.I.; Tokhtasjev, V.S.

    1987-01-01

    Studies of meteor showers permit the solving of some principal problems of meteor astronomy: to obtain the structure of a stream in cross section and along its orbits; to retrace the evolution of particle orbits of the stream taking into account gravitational and nongravitational forces and to discover the orbital elements of its parent body; to find out the total mass of solid particles ejected from the parent body taking into account physical and chemical evolution of meteor bodies; and to use meteor streams as natural probes for investigation of the average characteristics of the meteor complex in the solar system. A simple and effective method of determining the flux density and mass exponent parameter was worked out. This method and its results are discussed

  4. Status of the large high altitude air shower observatory project

    Energy Technology Data Exchange (ETDEWEB)

    Zha, Min, E-mail: zham@ihep.ac.cn [Key Laboratory of Astroparticle and Cosmic Ray, Institute of High Energy Physics, YuQuan Road 19 B, 100049 Beijing (China)

    2012-11-11

    The Large High Altitude Air Shower Observatory (LHAASO) project is a multipurpose project. The main scientific tasks can be summarized as follows: (1) searching for galactic cosmic ray origins through gamma ray source detection above 30 TeV; (2) wide field of view survey for gamma ray sources at energies higher than 100 GeV; (3) energy spectrum measurements for individual cosmic ray species from 30 TeV to 10 PeV. To target above tasks, a complex detector array is designed. This paper describes the progress on the research and development of all kind of detectors. Construction and operation of a prototype detector array at Tibet site with 4300 m a.s.l. are also presented.

  5. The efficacy of showers for control of ectoparasites of sheep.

    Science.gov (United States)

    Kirkwood, A C; Quick, M P

    1978-01-21

    Ectoparasites of sheep in Britain include the tick Ixodes ricinus, the blowfly, Lucilia sericata, the ked, Melophagus ovinus and the lice, Damalinia ovis and Linognathus ovillus. The most important ectoparasite, however, is the mite Psoroptes communis ovis which causes sheep scab. This notifiable disease was eradicated from Britain in 1952 but was reported again in 1973. The control of ectoparasites depends largely on the efficient application of insecticide to the fleece and skin. Plunge dipping in a bath is generally regarded as the most efficient method and is compulsory for the control of sheep scab but it is not always the most convenient. After the eradication of sheep scab in 1952 plunge dipping was no longer compulsory and jetting, spraying and showering techniques were then employed for the other ectoparasites.

  6. Searching for mini black holes signatures in cosmic rays air shower

    Energy Technology Data Exchange (ETDEWEB)

    Lamri, S.; Kalli, S.; Mimouni, J. [Physics Department, El-Hadj Lakhdar University (Algeria); Physics Department, Mohamed Boudiaf University (Algeria); Laboratoire de Physique Mathematique et Subatomique, Mentouri University (Algeria)

    2012-06-27

    Theories with extra dimensions at low Planck scale, offer the exciting possibility of mini black holes production in ultra high-energy particles interactions. In particular, cosmic neutrinos interaction can produce black holes deep in the Earth's atmosphere. These mini black holes then decay and produce 'characteristic' air showers. In this paper, we examine the properties of the mini black holes (mBH) air showers and compare them to the standard model (mSM) ones. We point out to some possible criteria that help distinguishing mBH air showers.

  7. Simulation of radio emission from air showers in atmospheric electric fields

    OpenAIRE

    Buitink, S.

    2010-01-01

    We study the effect of atmospheric electric fields on the radio pulse emitted by cos- mic ray air showers. Under fair weather conditions the dominant part of the radio emission is driven by the geomagnetic field. When the shower charges are acceler- ated and deflected in an electric field additional radiation is emitted. We simulate this effect with the Monte Carlo code REAS2, using CORSIKA-simulated showers as input. In both codes a routine has been implemented that treats the effect of the ...

  8. Shower steamer burns in a toddler: case report and brief review of steam burns in children.

    Science.gov (United States)

    Brywczynski, Jeremy; Arnold, Donald H

    2008-11-01

    Commercial "shower-steamers" are relatively new devices used to produce a sauna-like effect in standard showers. These devices produce superheated steam to temperatures greater than 100 degrees C. The steam-head is installed 12 in. above the shower floor or 8 in. above the tub edge, making accidental burn injury to children a real possibility, as in our case report. To our knowledge, there are no previously documented cases in the literature or on the Consumer Products Safety Commission Web site of thermal injuries from this device. Physicians need to be aware of the possible injury from such steamers, and public education to prevent further incidents is warranted.

  9. Shower and no-dressing technique for tunneled central venous hemodialysis catheters: a quality improvement initiative.

    Science.gov (United States)

    Lawrence, Julie Ann; Seiler, Suzanne; Wilson, Barbara; Harwood, Lori

    2014-01-01

    Self-care practices and quality-of-life nuances juxtaposed our tunneled hemodialysis central venous catheter (CVC) protocols. Despite our advice, individuals with CVCs were showering. As a quality improvement initiative, we compared the standard CVC dressing practices to the "shower and no-dressing" technique. After 1380 catheter months (n = 119) infection rates were 0.31 events per 1000 catheter days. The "shower and no-dressing" technique appears to be a safe CVC dressing option with improved quality of life, no increase in infection rates, and cost-effectiveness.

  10. Potentially pathogenic bacteria in shower water and air of a stem cell transplant unit.

    Science.gov (United States)

    Perkins, Sarah D; Mayfield, Jennie; Fraser, Victoria; Angenent, Largus T

    2009-08-01

    Potential pathogens from shower water and aerosolized shower mist (i.e., shower aerosol) have been suggested as an environmental source of infection for immunocompromised patients. To quantify the microbial load in shower water and aerosol samples, we used culture, microscopic, and quantitative PCR methods to investigate four shower stalls in a stem cell transplant unit at Barnes-Jewish Hospital in St. Louis, MO. We also tested membrane-integrated showerheads as a possible mitigation strategy. In addition to quantification, a 16S rRNA gene sequencing survey was used to characterize the abundant bacterial populations within shower water and aerosols. The average total bacterial counts were 2.2 x 10(7) cells/liter in shower water and 3.4 x 10(4) cells/m(3) in shower aerosol, and these counts were reduced to 6.3 x 10(4) cells/liter (99.6% efficiency) and 8.9 x 10(3) cells/m(3) (82.4% efficiency), respectively, after membrane-integrated showerheads were installed. Potentially pathogenic organisms were found in both water and aerosol samples from the conventional showers. Most notable was the presence of Mycobacterium mucogenicum (99.5% identity) in the water and Pseudomonas aeruginosa (99.3% identity) in the aerosol samples. Membrane-integrated showerheads may protect immunocompromised patients from waterborne infections in a stem cell transplant unit because of efficient capture of vast numbers of potentially pathogenic bacteria from hospital water. However, an in-depth epidemiological study is necessary to investigate whether membrane-integrated showerheads reduce hospital-acquired infections. The microbial load in shower aerosols with conventional showerheads was elevated compared to the load in HEPA-filtered background air in the stem cell unit, but it was considerably lower than typical indoor air. Thus, in shower environments without HEPA filtration, the increase in microbial load due to shower water aerosolization would not have been distinguishable from

  11. Energy and momentum deposited into a QCD medium by a jet shower.

    Science.gov (United States)

    Qin, G-Y; Majumder, A; Song, H; Heinz, U

    2009-10-09

    For a hard parton moving through a dense QCD medium, we compute self-consistently the energy loss and the fraction deposited into the medium due to showering and rescattering of the shower, assuming weak coupling between probe and medium. The same transport coefficients thus determine both the energy loss and its deposition into the medium. This allows a parameter free calculation of the latter once the former are computed or measured. We compute them for a weakly interacting medium. Assuming a short thermalization time for the deposited energy, we determine the medium's hydrodynamical response and obtain a conical pattern that is strongly enhanced by showering.

  12. Search for non-random features in arrival times of air showers

    International Nuclear Information System (INIS)

    Ochi, N.; Wada, T.; Yamashita, Y.; Ohashi, A.; Okada, T.; Yamamoto, I.; Nakatsuka, T.

    2001-01-01

    It was searched for non-random components in arrival times of air showers of mean energy of 1 PeV. By counting the number of air showers observed within time windows of 20-60 minutes, it was found small deviation of air shower data from the conventional view of uniformly random cosmic ray injection. The arrival directions of the non-random events concentrate at the direction of the Galactic plane. Though the significance of these events is not so high because of the lack of statistics, they may be induced by sporadic non-random injection of ultra-high energy γ-rays from the Galactic plane

  13. The electromagnetic shower library for the Stockholm AMANDA Monte Carlo program

    International Nuclear Information System (INIS)

    Sun Qin.

    1996-05-01

    The Shower Library has been applied in the simulation for the AMANDA experiment which measures up-going muons induced by high energy neutrinos at the South Pole. With a detector measuring Cherenkov radiation in mind, only the information of the Cherenkov photons from the showers were stored in the library in the version of the program described here. The library contains 1000 electromagnetic showers with energies from 0.1 GeV to 100 GeV in steps according to a flat logarithmic distribution. 11 refs, 18 figs

  14. A computer system to analyze showers in nuclear emulsions: Center Director's discretionary fund report

    Science.gov (United States)

    Meegan, C. A.; Fountain, W. F.; Berry, F. A., Jr.

    1987-01-01

    A system to rapidly digitize data from showers in nuclear emulsions is described. A TV camera views the emulsions though a microscope. The TV output is superimposed on the monitor of a minicomputer. The operator uses the computer's graphics capability to mark the positions of particle tracks. The coordinates of each track are stored on a disk. The computer then predicts the coordinates of each track through successive layers of emulsion. The operator, guided by the predictions, thus tracks and stores the development of the shower. The system provides a significant improvement over purely manual methods of recording shower development in nuclear emulsion stacks.

  15. Study of the hadron shower profiles with the ATLAS tile hadron calorimeter

    International Nuclear Information System (INIS)

    Budagov, Yu.A.; Rusakovich, N.A.; Vinogradov, V.B.; Kul'chitskij, Yu.A.; Rumyantsev, V.S.; Nessi, M.

    1997-01-01

    The lateral and longitudinal profiles of the hadronic showers detected by ATLAS iron-scintillator tile hadron calorimeter with longitudinal tile configuration have been investigated. The results are based on 100 GeV pion beam data. Due to the beam scan provided many different beam impact locations with cells it is succeeded to obtain detailed picture of transverse shower behavior. The underlying radial energy densities for four depths and for overall calorimeter have been reconstructed. The three-dimensional hadronic shower parametrization has been suggested

  16. Experimental study of high-energy muons in the composition of extensive air showers

    International Nuclear Information System (INIS)

    Vashkevich, V.V.; Ermakov, G.G.; Ermolov, P.F.

    1988-01-01

    Experimental results are reported on high-energy muon fluxes (the muon threshold energies from 10 to 500 GeV) measured by means of the magnetic spectrometer for study on extensive air showers. Space distributions of muons, energy spectra and dependence of the characteristics of the muon-component upon the shower age parameter, upon the sign of the muon charge and upon the number of particles in the shower N e in the range N e =5x10 4 -3x10 6 are presented

  17. On the transverse momentum in Z-boson production in a virtually ordered parton shower

    Energy Technology Data Exchange (ETDEWEB)

    Nagy, Zoltan [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Soper, Davison E. [Oregon Univ., Eugene, OR (United States). Inst. of Theoretical Science

    2009-12-15

    Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using parton showers is to sum these large logarithms. We ask whether this goal is achieved for the transverse momentum distribution of a Z-boson produced in hadron-hadron collisions when the shower is organized with higher virtuality parton splittings coming first, followed successively by lower virtuality parton splittings. We find that the virtuality ordered shower works well in reproducing the known QCD result. (orig.)

  18. Don Quixote-A possible parent body of a meteor shower

    Science.gov (United States)

    Rudawska, Regina; Vaubaillon, Jeremie

    2015-12-01

    Asteroid 3552 Don Quixote (1983 SA) orbits the Sun on an orbit that resembles that of a short-period comet. This, together with its recently observed cometary activity, makes it a good candidate for a parent body of a meteor shower. Model calculations show that the particles originated from Don Quixote pass close enough to Earth orbit to search for a meteor shower activity. Corresponding meteor showers were found in CAMS (Rudawska and Jenniskens, 2014) and EDMOND (Kornoš et al., 2014) video observations. The κ Lyrids and August μ Draconids (IAU#464 and IAU#470, respectively), a similarly inclined stream active in the summer, are associated with 3552 Don Quixote.

  19. On the transverse momentum in Z-boson production in a virtually ordered parton shower

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2009-12-01

    Cross sections for physical processes that involve very different momentum scales in the same process will involve large logarithms of the ratio of the momentum scales when calculated in perturbation theory. One goal of calculations using parton showers is to sum these large logarithms. We ask whether this goal is achieved for the transverse momentum distribution of a Z-boson produced in hadron-hadron collisions when the shower is organized with higher virtuality parton splittings coming first, followed successively by lower virtuality parton splittings. We find that the virtuality ordered shower works well in reproducing the known QCD result. (orig.)

  20. Abnormal cascading failure spreading on complex networks

    International Nuclear Information System (INIS)

    Wang, Jianwei; Sun, Enhui; Xu, Bo; Li, Peng; Ni, Chengzhang

    2016-01-01

    Applying the mechanism of the preferential selection of the flow destination, we develop a new method to quantify the initial load on an edge, of which the flow is transported along the path with the shortest edge weight between two nodes. Considering the node weight, we propose a cascading model on the edge and investigate cascading dynamics induced by the removal of the edge with the largest load. We perform simulated attacks on four types of constructed networks and two actual networks and observe an interesting and counterintuitive phenomenon of the cascading spreading, i.e., gradually improving the capacity of nodes does not lead to the monotonous increase in the robustness of these networks against cascading failures. The non monotonous behavior of cascading dynamics is well explained by the analysis on a simple graph. We additionally study the effect of the parameter of the node weight on cascading dynamics and evaluate the network robustness by a new metric.

  1. Interband Cascade Laser Photon Noise

    Science.gov (United States)

    2009-09-01

    separated by an injection region composed of digitally graded Indium Arsenide (InAs)/ Aluminum Indium Antimonide (Al(In)Sb) multi-QWs. The active region...consists of coupled InAs, Gallium Indium Antimonide (GaInSb) and Gallium Antimonide (GaSb) QWs separated by Aluminum Antimonide (AlSb) barriers. Under... Antimonide AlInSb Aluminum Indium Antimonide cw constant wave DC direct current GaSb Gallium Antimonide IC Interband cascade InAs Indium Arsenide InSb

  2. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  3. Inverse design technique for cascades

    Science.gov (United States)

    Zannetti, L.; Pandolfi, M.

    1984-01-01

    A numerical technique to generate cascades is presented. The basic prescribed parameters are: inlet angle, exit pressure, and distribution of blade thickness and lift along a blade. Other sets of parameters are also discussed. The technique is based on the lambda scheme. The problem of stability of the computation as a function of the prescribed set of parameters and the treatment of boundary conditions is discussed. A one dimensional analysis to indicate a possible way for assuring stability for any two dimensional calculation is provided.

  4. Disaster Mythology and Availability Cascades

    Directory of Open Access Journals (Sweden)

    Lisa Grow Sun

    2013-04-01

    Full Text Available Sociological research conducted in the aftermath of natural disasters has uncovered a number of “disaster myths” – widely shared misconceptions about typical post-disaster human behavior. This paper discusses the possibility that perpetuation of disaster mythology reflects an “availability cascade,” defined in prior scholarship as a “self-reinforcing process of collective belief formation by which an expressed perception triggers a chain reaction that gives the perception increasing plausibility through its rising availability in public discourse.” (Kuran and Sunstein 1999. Framing the spread of disaster mythology as an availability cascade suggests that certain tools may be useful in halting the myths’ continued perpetuation. These tools include changing the legal and social incentives of so-called “availability entrepreneurs” – those principally responsible for beginning and perpetuating the cascade, as well as insulating decision-makers from political pressures generated by the availability cascade. This paper evaluates the potential effectiveness of these and other solutions for countering disaster mythology. Las investigaciones sociológicas realizadas tras los desastres naturales han hecho evidentes una serie de “mitos del desastre”, conceptos erróneos ampliamente compartidos sobre el comportamiento humano típico tras un desastre. Este artículo analiza la posibilidad de que la perpetuación de los mitos del desastre refleje una “cascada de disponibilidad”, definida en estudios anteriores como un “proceso de auto-refuerzo de la formación de una creencia colectiva, a través del que una percepción expresada produce una reacción en cadena que hace que la percepción sea cada vez más verosímil, a través de una mayor presencia en el discurso público” (Kuran y Sunstein 1999. Enmarcar la propagación de los mitos del desastre como una cascada de disponibilidad sugiere que ciertas herramientas pueden ser

  5. Ion-implantation dense cascade data

    International Nuclear Information System (INIS)

    Winterbon, K.B.

    1983-04-01

    A tabulation is given of data useful in estimating various aspects of ion-implantation cascades in the nuclear stopping regime, particularly with respect to nonlinearity of the cascade at high energy densities. The tabulation is restricted to self-ion implantation. Besides power-cross-section cascade dimensions, various material properties are included. Scaling of derived quantities with input data is noted, so one is not limited to the values assumed by the author

  6. A non-conventional isotope separation cascade without any mixing: net cascade

    International Nuclear Information System (INIS)

    Zeng Shi; Jiang Dongjun; Ying Zhengen

    2012-01-01

    A component has different concentrations in the incoming flows at a confluent point in all existing isotope separations cascades for multi-component isotope separation and mixing is inevitable, which results in deterioration of separation performance of the separation cascade. However, realization of no-mixing at a confluent point is impossible with a conventional cascade. A non-conventional isotope separation cascade, net cascade, is found to be able to realize no mixings for all components at confluent points, and its concept is further developed here. No-mixing is fulfilled by requiring symmetrical separation of two specified key components at every stage, and the procedure of realizing no-mixing is presented in detail. Some properties of net cascade are investigated preliminarily, and the results demonstrated the no-mixing property is indeed realized. Net cascade is the only separation cascade that so far possesses the no-mixing property. (authors)

  7. Contingency Analysis of Cascading Line Outage Events

    Energy Technology Data Exchange (ETDEWEB)

    Thomas L Baldwin; Magdy S Tawfik; Miles McQueen

    2011-03-01

    As the US power systems continue to increase in size and complexity, including the growth of smart grids, larger blackouts due to cascading outages become more likely. Grid congestion is often associated with a cascading collapse leading to a major blackout. Such a collapse is characterized by a self-sustaining sequence of line outages followed by a topology breakup of the network. This paper addresses the implementation and testing of a process for N-k contingency analysis and sequential cascading outage simulation in order to identify potential cascading modes. A modeling approach described in this paper offers a unique capability to identify initiating events that may lead to cascading outages. It predicts the development of cascading events by identifying and visualizing potential cascading tiers. The proposed approach was implemented using a 328-bus simplified SERC power system network. The results of the study indicate that initiating events and possible cascading chains may be identified, ranked and visualized. This approach may be used to improve the reliability of a transmission grid and reduce its vulnerability to cascading outages.

  8. Meteor Shower Activity Derived from "Meteor Watching Public-Campaign" in Japan

    Science.gov (United States)

    Sato, M.; Watanabe, J.

    2011-01-01

    We tried to analyze activities of meteor showers from accumulated data collected by public campaigns for meteor showers which were performed as outreach programs. The analyzed campaigns are Geminids (in 2007 and 2009), Perseids (in 2008 and 2009), Quadrantids (in 2009) and Orionids (in 2009). Thanks to the huge number of reports, the derived time variations of the activities of meteor showers is very similar to those obtained by skilled visual observers. The values of hourly rates are about one-fifth (Geminids 2007) or about one-fourth (Perseids 2008) compared with the data of skilled observers, mainly due to poor observational sites such as large cities and urban areas, together with the immature skill of participants in the campaign. It was shown to be highly possible to estimate time variation in the meteor shower activity from our campaign.

  9. Opportunistic Pathogens Mycobacterium Avium Complex (MAC) and Legionella spp. Colonise Model Shower.

    Science.gov (United States)

    Whiley, Harriet; Giglio, Steven; Bentham, Richard

    2015-07-24

    Legionella spp. and Mycobacterium avium complex (MAC) are opportunistic pathogens of public health concern. Hot water systems, including showers, have been identified as a potential source of infection. This paper describes the colonization of Legionella and MAC on the flexible tubing within a model potable shower system, utilizing thermostatic mixing and a flexible shower head. A MAC qPCR method of enumeration was also developed. MAC and Legionella spp. were detected within the biofilm at maximum concentrations of 7.0 × 104 and 2.0 × 103 copies/cm2 PVC tubing respectively. No significant changes were observed between sample of the flexible shower tubing that dried between uses and those that remained filled with water. This suggested the "unhooking" showerheads and allowing them to dry is not an effective method to reduce the risk of Legionella or MAC colonisation.

  10. QCD parton showers and NLO EW corrections to Drell-Yan

    CERN Document Server

    Richardson, P; Sapronov, A A; Seymour, M H; Skands, P Z

    2012-01-01

    We report on the implementation of an interface between the SANC generator framework for Drell-Yan hard processes, which includes next-to-leading order electroweak (NLO EW) corrections, and the Herwig++ and Pythia8 QCD parton shower Monte Carlos. A special aspect of this implementation is that the initial-state shower evolution in both shower generators has been augmented to handle the case of an incoming photon-in-a-proton, diagrams for which appear at the NLO EW level. The difference between shower algorithms leads to residual differences in the relative corrections of 2-3% in the p_T(mu) distributions at p_T(mu)>~50 GeV (where the NLO EW correction itself is of order 10%).

  11. Water Use Patterns in Vietnamese Hotels: Modeling Toilet and Shower Usage

    Directory of Open Access Journals (Sweden)

    Kanako Toyosada

    2016-03-01

    Full Text Available Water saving is a key issue in rapidly developing countries, such as Vietnam, that face various water resource management challenges. This study investigated water-use patterns in a hotel in Ho Chi Minh City in Vietnam. It aimed to quantify the efficiency of water-saving devices through modeling toilet and shower usage patterns, including water consumption. The shift in hourly consumption of cold and hot water was also identified. Analysis revealed that, on average, a full toilet flush occurs 3.3 times/day, a half flush 3.0 times/day, water consumption due to shower usage is 48.1 L/day, showering time is 7.3 min/day and the shower water temperature is 37.7 °C. Shifting levels of hot and cold water use revealed high activity in the morning time and that there are two peaks, occurring in the morning and at night.

  12. Air shower simulation for background estimation in muon tomography of volcanoes

    Directory of Open Access Journals (Sweden)

    S. Béné

    2013-01-01

    Full Text Available One of the main sources of background for the radiography of volcanoes using atmospheric muons comes from the accidental coincidences produced in the muon telescopes by charged particles belonging to the air shower generated by the primary cosmic ray. In order to quantify this background effect, Monte Carlo simulations of the showers and of the detector are developed by the TOMUVOL collaboration. As a first step, the atmospheric showers were simulated and investigated using two Monte Carlo packages, CORSIKA and GEANT4. We compared the results provided by the two programs for the muonic component of vertical proton-induced showers at three energies: 1, 10 and 100 TeV. We found that the spatial distribution and energy spectrum of the muons were in good agreement for the two codes.

  13. Computing the electric field from extensive air showers using a realistic description of the atmosphere

    Science.gov (United States)

    Gaté, F.; Revenu, B.; García-Fernández, D.; Marin, V.; Dallier, R.; Escudié, A.; Martin, L.

    2018-03-01

    The composition of ultra-high energy cosmic rays is still poorly known and constitutes a very important topic in the field of high-energy astrophysics. Detection of ultra-high energy cosmic rays is carried out via the extensive air showers they create after interacting with the atmosphere constituents. The secondary electrons and positrons within the showers emit a detectable electric field in the kHz-GHz range. It is possible to use this radio signal for the estimation of the atmospheric depth of maximal development of the showers Xmax , with a good accuracy and a duty cycle close to 100%. This value of Xmax is strongly correlated to the nature of the primary cosmic ray that initiated the shower. We show in this paper the importance of using a realistic atmospheric model in order to correct for systematic errors that can prevent a correct and unbiased estimation of Xmax.

  14. GIGAS: A set of microwave sensor arrays to detect molecular bremsstrahlung radiation from extensive air shower

    Science.gov (United States)

    Gaïor, R.; Al Samarai, I.; Berat, C.; Blanco Otano, M.; David, J.; Deligny, O.; Lebbolo, H.; Lecoz, S.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Mariş, I. C.; Montanet, F.; Repain, P.; Salamida, F.; Settimo, M.; Stassi, P.; Stutz, A.

    2018-04-01

    We present the GIGAS (Gigahertz Identification of Giant Air Shower) microwave radio sensor arrays of the EASIER project (Extensive Air Shower Identification with Electron Radiometers), deployed at the site of the Pierre Auger cosmic ray observatory. The aim of these novel arrays is to probe the intensity of the molecular bremsstrahlung radiation expected from the development of the extensive air showers produced by the interaction of ultra high energy cosmic rays in the atmosphere. In the designed setup, the sensors are embedded within the surface detector array of the Pierre Auger observatory allowing us to use the particle signals at ground level to trigger the radio system. A series of seven, then 61 sensors have been deployed in the C-band, followed by a new series of 14 higher sensitivity ones in the C-band and the L-band. The design, the operation, the calibration and the sensitivity to extensive air showers of these arrays are described in this paper.

  15. Studying High pT muons in Cosmic-Ray Air Showers

    International Nuclear Information System (INIS)

    Klein, Spencer R.

    2006-01-01

    Most cosmic-ray air shower arrays have focused on detecting electromagnetic shower particles and low energy muons. A few groups (most notably MACRO + EASTOP and SPASE + AMANDA) have studied the high energy muon component of showers. However, these experiments had small solid angles, and did not study muons far from the core. The IceTop + IceCube combination, with its 1 km 2 muon detection area can study muons far from the shower core. IceCube can measure their energy loss (dE/dx), and hence their energy. With the energy, and the known distribution of production heights, the transverse momentum (p T ) spectrum of high p T muons can be determined. The production of the semuons is calculable in perturbative QCD, so the measured muon spectra can be used to probe the composition of incident cosmic-rays

  16. Deep Mapping of Small Solar System Bodies with Galactic Cosmic Ray Secondary Particle Showers Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Our Phase I study demonstrated that muons, the long-range charged component of GCR showers, can penetrate SSBs on the order of a km in diameter or less,...

  17. Studies of Cosmic Ray Composition and Air Shower Structure with the Pierre Auger Observatory

    OpenAIRE

    The Pierre Auger Collaboration; Abraham, J.; Abreu, P.; Aglietta, M.; Aguirre, C.; Ahn, E. J.; Allard, D.; Allekotte, I.; Allen, J.; Alvarez-Muñiz, J.; Ambrosio, M.; Anchordoqui, L.; Andringa, S.; Anzalone, A.; Aramo, C.

    2009-01-01

    Studies of the composition of the highest energy cosmic rays with the Pierre Auger Observatory, including examination of hadronic physics effects on the structure of extensive air showers. Submissions to the 31st ICRC, Lodz, Poland (July 2009).

  18. Lifespans of Cascade Arc volcanoes

    Science.gov (United States)

    Calvert, A. T.

    2015-12-01

    Compiled argon ages reveal inception, eruptive episodes, ages, and durations of Cascade stratovolcanoes and their ancestral predecessors. Geologic mapping and geochronology show that most Cascade volcanoes grew episodically on multiple scales with periods of elevated behavior lasting hundreds of years to ca. 100 kyr. Notable examples include the paleomag-constrained, few-hundred-year-long building of the entire 15-20 km3 Shastina edifice at Mt. Shasta, the 100 kyr-long episode that produced half of Mt. Rainier's output, and the 30 kyr-long episode responsible for all of South and Middle Sister. Despite significant differences in timing and rates of construction, total durations of active and ancestral volcanoes at discrete central-vent locations are similar. Glacier Peak, Mt. Rainier, Mt. Adams, Mt. Hood, and Mt. Mazama all have inception ages of 400-600 ka. Mt. St. Helens, Mt. Jefferson, Newberry Volcano, Mt. Shasta and Lassen Domefield have more recent inception ages of 200-300 ka. Only the Sisters cluster and Mt. Baker have established eruptive histories spanning less than 50 kyr. Ancestral volcanoes centered 5-20 km from active stratocones appear to have similar total durations (200-600 kyr), but are less well exposed and dated. The underlying mechanisms governing volcano lifecycles are cryptic, presumably involving tectonic and plumbing changes and perhaps circulation cycles in the mantle wedge, but are remarkably consistent along the arc.

  19. Relating meson and baryon fragmentation functions by shower-parton recombination

    International Nuclear Information System (INIS)

    Hwa, Rudolph C.; Yang, C.B.

    2006-01-01

    We relate the fragmentation functions of partons into mesons and baryons in the framework of recombination of shower partons. The results are in reasonable agreement with the data. The implication is that the meson and baryon fragmentation functions are not independent when hadronization of the shower partons is taken into account. The conclusion therefore closes a conceptual gap in the system of fragmentation functions, whose Q 2 evolution has been more extensively studied than the interrelationship among various species of hadrons produced

  20. Radio detection of cosmic ray air showers with the LOPES experiment

    International Nuclear Information System (INIS)

    Huege, T

    2008-01-01

    In the last few years, radio detection of cosmic ray air showers has experienced a true renaissance. In particular, the LOPES project has successfully implemented modern interferometric methods to measure radio emission from air showers. LOPES has confirmed that the emission is coherent and of geomagnetic origin, as expected by the geosynchrotron mechanism, and has demonstrated that a large scale application of the radio technique has great potential to complement current measurements of ultra-high energy cosmic rays

  1. Application of new digital network sensor for the electronics of shower counter in Beijing spectrum

    International Nuclear Information System (INIS)

    Xie Xiaoxi; Gao Cuishan; Nie Zhendong; Wang Jinzhu

    2003-01-01

    A new type of digital network sensor is used in electronics system of Shower Counter in Beijing Spectrum. These sensors compose a set of temperature patrol device for the Shower Counter crates, which greatly enhances the level of environment monitor of Beijing Spectrum. This successful work is a fine example to the task of Slow Control and Environment Monitor for Beijing Spectrum in BEPC II

  2. Survey costs associated with the replacement of electric showers for solar heaters

    International Nuclear Information System (INIS)

    Belchior, Fernando Nunes; Araujo, Jose Euripedes de

    2010-01-01

    This paper aims to explain the benefits of replacing electric shower for solar water heaters, and a consequent drop in peak demand for electric power generation and residential consumption in the economy. For this, will be shown the lifting of solar radiation per square meter in Brazil, studied in 250 locations, the most representative in terms of solar energy in this country. The costs presented are associated with replacement of 5 million, 10 million and 20 million electric showers. (author)

  3. Probing Atmospheric Electric Fields in Thunderstorms through Radio Emission from Cosmic-Ray-Induced Air Showers.

    Science.gov (United States)

    Schellart, P; Trinh, T N G; Buitink, S; Corstanje, A; Enriquez, J E; Falcke, H; Hörandel, J R; Nelles, A; Rachen, J P; Rossetto, L; Scholten, O; Ter Veen, S; Thoudam, S; Ebert, U; Koehn, C; Rutjes, C; Alexov, A; Anderson, J M; Avruch, I M; Bentum, M J; Bernardi, G; Best, P; Bonafede, A; Breitling, F; Broderick, J W; Brüggen, M; Butcher, H R; Ciardi, B; de Geus, E; de Vos, M; Duscha, S; Eislöffel, J; Fallows, R A; Frieswijk, W; Garrett, M A; Grießmeier, J; Gunst, A W; Heald, G; Hessels, J W T; Hoeft, M; Holties, H A; Juette, E; Kondratiev, V I; Kuniyoshi, M; Kuper, G; Mann, G; McFadden, R; McKay-Bukowski, D; McKean, J P; Mevius, M; Moldon, J; Norden, M J; Orru, E; Paas, H; Pandey-Pommier, M; Pizzo, R; Polatidis, A G; Reich, W; Röttgering, H; Scaife, A M M; Schwarz, D J; Serylak, M; Smirnov, O; Steinmetz, M; Swinbank, J; Tagger, M; Tasse, C; Toribio, M C; van Weeren, R J; Vermeulen, R; Vocks, C; Wise, M W; Wucknitz, O; Zarka, P

    2015-04-24

    We present measurements of radio emission from cosmic ray air showers that took place during thunderstorms. The intensity and polarization patterns of these air showers are radically different from those measured during fair-weather conditions. With the use of a simple two-layer model for the atmospheric electric field, these patterns can be well reproduced by state-of-the-art simulation codes. This in turn provides a novel way to study atmospheric electric fields.

  4. Interpretation of the cosmic-ray air shower signal in Askaryan radio detectors

    Directory of Open Access Journals (Sweden)

    de Vries Krijn D.

    2017-01-01

    Full Text Available We discuss the radio emission from a cosmic-ray air shower propagating in air before it hits an air-ice boundary after which it completes its propagation inside the ice. The in-air emission, the in-ice emission, as well as the transition radiation from the shower crossing the boundary is considered. We discuss the interpretation of the radio signal observed by an in-ice observer.

  5. Hadron shower decomposition in the highly granular CALICE analogue hadron calorimeter

    Czech Academy of Sciences Publication Activity Database

    Eigen, G.; Price, T.; Watson, N.K.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav

    2016-01-01

    Roč. 11, Jul (2016), 1-37, č. článku P06013. ISSN 1748-0221 R&D Projects: GA MŠk LG14033; GA MŠk 7E12050 Institutional support: RVO:68378271 Keywords : hadron showers * scintillator calorimeter s * simulation of showers Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.220, year: 2016

  6. Effects of skin care with shower therapy on children with atopic dermatitis in elementary schools.

    Science.gov (United States)

    Mochizuki, Hiroyuki; Muramatsu, Reiko; Tadaki, Hiromi; Mizuno, Takahisa; Arakawa, Hirokazu; Morikawa, Akihiro

    2009-01-01

    For elementary school children with atopic dermatitis, a skin care program using shower therapy was performed during the school lunch break for 6 weeks from June to July in 2004 and 2005. All 53 participants showed an improvement in their atopic dermatitis during the 6-week periods studied. Skin care with daily showering at an elementary school was thus found to be effective for the treatment of atopic dermatitis.

  7. The Parameterized Simulation of Electromagnetic Showers in Homogeneous and Sampling Calorimeters

    OpenAIRE

    Grindhammer, G.; Peters, S.

    2000-01-01

    A general approach to a fast simulation of electromagnetic showers using parameterizations of the longitudinal and radial profiles in homogeneous and sampling calorimeters is described. The dependence of the shower development on the materials used and the sampling geometry is taken into account explicitly. Comparisons with detailed simulations of various calorimeters and with data from the liquid argon calorimeter of the H1 experiment are made.

  8. The wavefront of the radio signal emitted by cosmic ray air showers

    Energy Technology Data Exchange (ETDEWEB)

    Apel, W.D.; Bekk, K.; Blümer, J.; Bozdog, H.; Daumiller, K.; Doll, P.; Engel, R. [Institut für Kernphysik, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Arteaga-Velázquez, J.C. [Instituto de Física y Matemáticas, Universidad Michoacana, Edificio C-3, Cd. Universitaria, C.P. 58040 Morelia, Michoacán (Mexico); Bähren, L.; Falcke, H. [ASTRON, Oude Hoogeveensedijk 4, 7991 PD Dwingeloo (Netherlands); Bertaina, M.; Cantoni, E.; Chiavassa, A.; Pierro, F. Di [Dipartimento di Fisica, Università degli Studi di Torino, Via Giuria 1, 10125 Torino (Italy); Biermann, P.L. [Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, 53121 Bonn (Germany); Brancus, I.M. [National Institute of Physics and Nuclear Engineering, Str. Reactorului no. 30, P.O. Box MG-6, Bucharest-Magurele (Romania); De Souza, V. [Instituto de Física de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense 400, Pq. Arnold Schmidt, São Carlos (Brazil); Fuchs, B. [Institut für Experimentelle Kernphysik, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Gemmeke, H. [Institut für Prozessdatenverarbeitung und Elektronik, Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany); Grupen, C., E-mail: frank.schroeder@kit.edu [Faculty of Natural Sciences and Engineering, Universität Siegen, Walter-Flex-Straße 3, 57072 Siegen (Germany); and others

    2014-09-01

    Analyzing measurements of the LOPES antenna array together with corresponding CoREAS simulations for more than 300 measured events with energy above 10{sup 17} eV and zenith angles smaller than 45{sup o}, we find that the radio wavefront of cosmic-ray air showers is of approximately hyperbolic shape. The simulations predict a slightly steeper wavefront towards East than towards West, but this asymmetry is negligible against the measurement uncertainties of LOPES. At axis distances ∼> 50 m, the wavefront can be approximated by a simple cone. According to the simulations, the cone angle is clearly correlated with the shower maximum. Thus, we confirm earlier predictions that arrival time measurements can be used to study the longitudinal shower development, but now using a realistic wavefront. Moreover, we show that the hyperbolic wavefront is compatible with our measurement, and we present several experimental indications that the cone angle is indeed sensitive to the shower development. Consequently, the wavefront can be used to statistically study the primary composition of ultra-high energy cosmic rays. At LOPES, the experimentally achieved precision for the shower maximum is limited by measurement uncertainties to approximately 140 g/c {sup 2}. But the simulations indicate that under better conditions this method might yield an accuracy for the atmospheric depth of the shower maximum, X{sub max}, better than 30 g/c {sup 2}. This would be competitive with the established air-fluorescence and air-Cherenkov techniques, where the radio technique offers the advantage of a significantly higher duty-cycle. Finally, the hyperbolic wavefront can be used to reconstruct the shower geometry more accurately, which potentially allows a better reconstruction of all other shower parameters, too.

  9. The determination of parameters of shower initiated in imaging calorimeter by electrons and protons

    International Nuclear Information System (INIS)

    Borisov, S.V.; Voronov, S.A.; Karelin, A.V.; Koldobskij, S.A.; Runtso, M.F.

    2010-01-01

    In this work the report on several methods of shower axis reconstruction and methods of search for the starting point of the shower are presented. They were developed for 'thin' sampling imaging calorimeters. For this purpose we used a Monte-Carlo simulation of interaction of electrons and protons with a silicon-tungsten calorimeter of PAMELA satellite-borne experiment. After some adaptation, these methods could be applied for different types of calorimeters

  10. Conclusions of the workshop on the ATLAS requirements on shower models

    CERN Document Server

    Bosman, M; Efthymiopoulos, I; Froidevaux, D; Gianotti, F; Kiryunin, A E; Knobloch, J; Loch, P; Osculati, B; Perini, L; Sala, P R; Seman, M

    1999-01-01

    The workshop addressed the question of shower models/packages and related issues needed for the simulation of ATLAS physics and test beam data. Part of the material discussed during the workshop is reviewed in this note. Results presented on the comparison berween ATLAS test beam data and Monte Carlo prediction of various shower models are briefly summarized. The requirements put forward by the various detector communities and first attempts to quantify them are being reviewed.

  11. A shower look-up table to trace the dynamics of meteoroid streams and their sources

    Science.gov (United States)

    Jenniskens, Petrus

    2018-04-01

    Meteor showers are caused by meteoroid streams from comets (and some primitive asteroids). They trace the comet population and its dynamical evolution, warn of dangerous long-period comets that can pass close to Earth's orbit, outline volumes of space with a higher satellite impact probability, and define how meteoroids evolve in the interplanetary medium. Ongoing meteoroid orbit surveys have mapped these showers in recent years, but the surveys are now running up against a more and more complicated scene. The IAU Working List of Meteor Showers has reached 956 entries to be investigated (per March 1, 2018). The picture is even more complicated with the discovery that radar-detected streams are often different, or differently distributed, than video-detected streams. Complicating matters even more, some meteor showers are active over many months, during which their radiant position gradually changes, which makes the use of mean orbits as a proxy for a meteoroid stream's identity meaningless. The dispersion of the stream in space and time is important to that identity and contains much information about its origin and dynamical evolution. To make sense of the meteor shower zoo, a Shower Look-Up Table was created that captures this dispersion. The Shower Look-Up Table has enabled the automated identification of showers in the ongoing CAMS video-based meteoroid orbit survey, results of which are presented now online in near-real time at http://cams.seti.org/FDL/. Visualization tools have been built that depict the streams in a planetarium setting. Examples will be presented that sample the range of meteoroid streams that this look-up table describes. Possibilities for further dynamical studies will be discussed.

  12. Application of an image intensifier to the study on hadrons in air shower, 4

    International Nuclear Information System (INIS)

    Tsushima, Itsuro; Kawasumi, Norio; Hashimoto, Katsumi; Machida, Masaharu

    1975-01-01

    As the apparatus for observing cosmic ray air shower, the particle detection apparatus combining spark chamber, scintillator and photomultiplier tube is frequently used, but the exact detection of particle number is impossible with it when particle density is large. The authors have carried out the experiment to measure nuclear active particles in air shower and to grasp the central part of air shower as energy flow by utilizing an image intensifier tube. On the roof of building S, a laboratory was built, and a core detector of 2 m x 2 m area, 13 AS detectors of 0.25 m 2 and an AS detector of 1 m 2 were installed. The gate of the II was opened by utilizing coincidence pulses, and the position and amount of scintillation in the core detector was taken into a camera through the II. The time of observation was 289 hours, and the time of II operation was 113 hours. Total number of air shower recorded was 218 cases, and the centers of 120 cases among them were determined in the AS detectors at four corners. The centers of 39 cases were within the area of the core detector. In the coincident counting of air shower and burst carried out in the present experiment, the total delay time from the arrival of air shower to the gate pulse actuating the II was 1.6 sec. The core of air shower of about 10 6 size and 1.3 age was caught by this method. The problems for future are the determination of core position for the air shower of smaller size, and the meaning of spot images of II. (Kako, I.)

  13. Measurement of the time development of particle showers in a uranium scintillator calorimeter

    International Nuclear Information System (INIS)

    Caldwell, A.; Hervas, L.; Parsons, J.A.; Sciulli, F.; Sippach, W.; Wai, L.

    1993-01-01

    We report on the time evolution of particle showers, as measured in modules of the uranium-scintillator barrel calorimeter of the ZEUS detector. The time development of hadronic showers differs significantly from that of electromagnetic showers, with about 40% of the response to hadronic showers arising from energy depositions which occur late in the shower development. The degree of compensation and the hadronic energy resolution were measured as a function of integration time, giving a value of e/π=1.02±0.01 for a gate width of 100 ns. The possibilities for electron-hadron separation based on the time structure of the shower were studied, with pion rejection factors in excess of 100 being achieved for electron efficiencies greater than 60%. The custom electronics used to perform these measurements samples the calorimeter signal at close to 60 MHz, stores all samples for a period of over 4 μs using analog switched capacitor pipelines, and digitizes the samples for triggered events with 12-bit ADCs. (orig.)

  14. Radio emission of air showers with extremely high energy measured by the Yakutsk Radio Array

    Science.gov (United States)

    Knurenko, S. P.; Petrov, Z. E.; Petrov, I. S.

    2017-09-01

    The Yakutsk Array is designed to study cosmic rays at energy 1015 -1020 eV. It consists several independent arrays that register charged particles, muons with energy E ≥ 1 GeV, Cherenkov light and radio emission. The paper presents a technical description of the Yakutsk Radio Array and some preliminary results obtained from measurements of radio emission at 30-35 MHz frequency induced by air shower particles with energy ε ≥ 1 ṡ1017 eV. The data obtained at the Yakutsk array in 1986-1989 (first set of measurements) and 2009-2014 (new set of measurements). Based on the obtained results we determined: Lateral distribution function (LDF) of air showers radio emission with energy ≥1017 eV. Radio emission amplitude empirical connection with air shower energy. Determination of depth of maximum by ratio of amplitude at different distances from the shower axis. For the first time, at the Yakutsk array radio emission from the air shower with energy >1019 eV was registered including the shower with the highest energy ever registered at the Yakutsk array with energy ∼ 2 ṡ1020 eV.

  15. The Effect of Cold Showering on Health and Work: A Randomized Controlled Trial

    Science.gov (United States)

    Sierevelt, Inger N.; van der Heijden, Bas C. J. M.; Dijkgraaf, Marcel G.; Frings-Dresen, Monique H. W.

    2016-01-01

    Purpose The aim of this study was to determine the cumulative effect of a routine (hot-to-) cold shower on sickness, quality of life and work productivity. Methods Between January and March 2015, 3018 participants between 18 and 65 years without severe comorbidity and no routine experience of cold showering were randomized (1:1:1:1) to a (hot-to-) cold shower for 30, 60, 90 seconds or a control group during 30 consecutive days followed by 60 days of showering cold at their own discretion for the intervention groups. The primary outcome was illness days and related sickness absence from work. Secondary outcomes were quality of life, work productivity, anxiety, thermal sensation and adverse reactions. Results 79% of participants in the interventions groups completed the 30 consecutive days protocol. A negative binomial regression model showed a 29% reduction in sickness absence for (hot-to-) cold shower regimen compared to the control group (incident rate ratio: 0.71, P = 0.003). For illness days there was no significant group effect. No related serious advents events were reported. Conclusion A routine (hot-to-) cold shower resulted in a statistical reduction of self-reported sickness absence but not illness days in adults without severe comorbidity. Trial Registration Netherlands National Trial Register NTR5183 PMID:27631616

  16. Measurement of the time development of particle showers in a uranium scintillator calorimeter

    International Nuclear Information System (INIS)

    Caldwell, A.; Hervas, L.; Parsons, J.A.; Sciulli, F.; Sippach, W.; Wai, L.

    1992-11-01

    We report on the time evolution of particle showers, as measured in modules of the uranium-scintillator barrel calorimeter of the ZEUS detector. The time development of hadronic showers differs significantly from that of electromagnetic showers, with about 40% of the response to hadronic showers arising from energy depositions which occur late in the shower development. The degree of compensation and the hadronic energy resolution were measured as a function of integration time, giving a value of e/π=1.02±0.01 for a gate width of 100 ns. The possibilities for electron-hadron separation based on the time structure of the shower were studied, with pion rejection factors in excess of 100 being achieved for electron efficiencies greater than 60%. The custom electronics used to perform these measurements samples the calorimeter signal at close to 60 MHz, stores all samples for a period of over 4 μs using analog switched capacitor pipelines, and digitizes the samples for triggered events with 12-bit ADC's. (orig.)

  17. Centrifugal separator cascade connected in zigzag manner

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Nagakura, Masaaki.

    1974-01-01

    Object: To effectively accommodate centrifugal separators of the entire cascade within the available space in a plant by freely selecting perpendicular direction of connection of the centrifugal separator. Structure: Centrifugal separators are connected in zigzag fashion by using a single header for each stage so that in a rectangular shape the entire cascade is arranged. (Kamimura, M.)

  18. Cascade Harvest’ red raspberry

    Science.gov (United States)

    Cascade Harvest’ is a new floricane fruiting raspberry cultivar (Rubus idaeus L.) jointly released by Washington State University (WSU), Oregon State University (OSU) and the U.S. Department of Agriculture (USDA). ‘Cascade Harvest’ produces a high yield of large, firm fruit suited to machine harves...

  19. Availability Cascades & the Sharing Economy

    DEFF Research Database (Denmark)

    Netter, Sarah

    2014-01-01

    In search of a new concept that will provide answers to as to how modern societies should not only make sense but also resolve the social and environmental problems linked with our modes of production and consumption, collaborative consumption and the sharing economy are increasingly attracting...... attention. This conceptual paper attempts to explain the emergent focus on the sharing economy and associated business and consumption models by applying cascade theory. Risks associated with this behavior will be especially examined with regard to the sustainability claim of collaborative consumption....... With academics, practitioners, and civil society alike having a shared history in being rather fast in accepting new concepts that will not only provide business opportunities but also a good conscience, this study proposes a critical study of the implications of collaborative consumption, before engaging...

  20. Cascade Error Projection: An Efficient Hardware Learning Algorithm

    Science.gov (United States)

    Duong, T. A.

    1995-01-01

    A new learning algorithm termed cascade error projection (CEP) is presented. CEP is an adaption of a constructive architecture from cascade correlation and the dynamical stepsize of A/D conversion from the cascade back propagation algorithm.

  1. Extensive air showers, lightnings and thunderstorm ground enhancements

    International Nuclear Information System (INIS)

    Chilingarian, A.; Hovsepyan, G.; Kozliner, L.

    2016-01-01

    For the lightning research, we monitor the particle fluxes from thunderclouds, the so called Thunderstorm Ground Enhancements (TGEs) initiated by the runaway electrons, and Extensive Air Showers (EASs) originated from high energy protons or fully stripped nuclei that enter the Earth’s atmosphere. Besides, we monitor the near-surface electric field and the atmospheric discharges with the help of a network of electric field mills. The Aragats “electron accelerator” produced plenty of TGE and lightning events in spring 2015. Using 1-sec time series, we investigated the relation of lightnings and particle fluxes. Lightning flashes often terminated the particle flux; during some of TGEs the lightning would terminate the particle flux 3 times after successive recovery. It was postulated that a lightning terminates a particle flux mostly in the beginning of TGE or on the decay phase of it; however, we observed two events (19 October 2013 and 20 April 2015) when the huge particle flux was terminated just on a maximum of its development. We discuss the possibility that a huge EAS facilitates lightning leader to find its path to the ground. (author)

  2. The silicon shower maximum detector for the STIC

    International Nuclear Information System (INIS)

    Alvsvaag, S.J.; Maeland, O.A.; Klovning, A.

    1995-01-01

    The structure of a shashlik calorimeter allows the insertion of tracking detectors within the longitudinal sampling to improve the accuracy in the determination of the direction of the showering particle and the e/π separation ability. The new forward calorimeter of the DELPHI detector has been equipped with two planes of silicon pad detectors respectively after 4 and 7.4 radiation lengths. The novelty of these silicon detectors is that to cope with the shashlik readout fibers, they had to incorporate 1.4 mm holes every cm 2 . The detector consists of circular strips with a radial pitch of 1.7 mm and an angular granularity of 22.5 , read out by means of the MX4 preamplifier. The preamplifier is located at 35 cm from the silicon detector and the signal is carried by Kapton cables bonded to the detector. The matching to the MX4 input pitch of 44 μm was made by a specially developed fanin hybrid. (orig.)

  3. Energy Sources for Yotta-TeV Iceberg Showers

    Energy Technology Data Exchange (ETDEWEB)

    MacAyeal, Douglas [University of Chicago

    2013-05-01

    In late February of 2002, warming climate along the Antarctic Peninsula triggered a macroscopic particle acceleration event that smashed a 350 Gkg floating ice shelf, called the Larsen B. The particle shower released by the acceleration involved on the order of >10^6 iceberg particles accelerated to an aggregate total kinetic energy of ~10^17 J (100 Mt TNT equivalent). The explosion was so extreme that it caught glaciological science by surprise (an injury to the egos of glaciologists worldwide) and caused glaciers of the Antarctic Peninsula formerly buttressed by the missing ice shelf to surge (yielding a small increment to sea level rise). In this presentation, I shall describe research, both experimental and field oriented, that has revealed the energy source for this explosive event. I shall also describe how climate warming has the capacity to trigger this type of ice-shelf collapse. A review of the geologic record of ice-rafted debris on the ocean floor suggests that extreme, explosive ice-shelf collapse may be a ubiquitous catastrophe that has happened regularly in the past as part of glacial/interglacial climate cycles.

  4. Atmospheric Effects on Cosmic Ray Air Showers Observed with HAWC

    Science.gov (United States)

    Young, Steven

    2014-01-01

    The High Altitude Water Cherenkov Gamma Ray detector (HAWC), currently under construction on the Sierra Negra volcano near Puebla, Mexico, can be used to study solar physics with its scaler data acquisition system. Increases in the scaler rates are used to observe GeV cosmic rays from solar flares while decreases in the rates show the heliospheric disturbances associated with coronal mass ejections. However, weather conditions and height-dependent state variables such as pressure and temperature affect the production of extensive particle air showers that can be detected by the scaler system. To see if these atmospheric effects can be removed, we obtained local weather data from the Global Data Assimilation System (GDAS) and the local weather station at HAWC. The scaler pulse rates were then correlated to the pressure and temperature. We present data from a Forbush decrease observed by HAWC following a significant coronal mass ejection in April 2013, and describe our efforts to remove atmospheric variations from the scaler counts. This work was partially supported by the National Science Foundation’s REU program through NSF Award AST-1004881 to the University of Wisconsin-Madison.

  5. Upgrading the water Cherenkov tanks for atmospheric shower identification

    Science.gov (United States)

    Billoir, Pierre

    2017-12-01

    The nature and the sources of the cosmic rays of ultra-high energy are not yet elucidated. The cutoff of the spectrum around 50 EeV is now clearly established, but its interpretation is still ambiguous: it could be due to the so-called GZK effect on a flux dominated by protons, or by an upper bound on the acceleration in the sources, or a combined scenario. To answer these questions the identification of the nature of the primaries is crucial. Present ground based detectors, especially water Cherenkov tanks, provide some indicators, in complement to the depth of maximum directly measured by fluorescence telescopes; but these indicators rely on models of the hadronic interactions at ultra-high energy, which cannot be observed in present colliders. One key feature to set more constraints on the development of atmospheric showers is a separate measurement of their electromagnetic and muonic components. Water Cherenkov tanks are sensitive to both, but cannot disentangle them in a clean and model-independent way. We present different options that have been studied to upgrade water Cherenkov tanks, either by modifying their internal structure, or by adding above of below the tank another type of detector, with a different relative sensitivity to muons and photons/electrons.

  6. Multiple-shower thromboembolism in an artificial mitral valve patient.

    Science.gov (United States)

    Argov, Ori; Weintraub, Moshe; Charach, Gideon

    2013-01-03

    Late acute left atrial thrombosis is a rare life-threatening complication that mostly appears with predisposing primary coagulopathy, such as Protein C, Protein S, antithrombin 3 deficiency, antiphospholipid syndrome or hyperhomocysteinemia. We present grave outcome due to lack of anticoagulation in a patient with artificial mitral valve. A 47-year-old male known to have an artificial valve was hospitalized in another hospital due to an acute illness. Anti-coagulation therapy was not provided during that hospitalization. He was transferred to our hospital due to lower limb weakness and diagnosed by us as having extensive emboli disease with complete occlusion of the distal aorta. Multiple infarcts were found in the abdominal organs and leg muscles. He suffered from multiple organ failure and eventually died. Neglecting the common practice of anticoagulation to a patient with a mechanical heart valve may, in rare cases, lead to immediate catastrophic event caused by shower thrombemboli with disseminated vascular occlusion from the left atrium to the abdominal aorta causing complete occlusion, spleen, kidney and muscle infarcts.

  7. An ionization chamber shower detector for the LHC luminosity monitor

    CERN Document Server

    Beche, J F; Datte, P S; Haguenauer, Maurice; Manfredi, P F; Millaud, J E; Placidi, Massimo; Ratti, L; Re, V; Riot, V J; Schmickler, Hermann; Speziali, V; Turner, W C

    2000-01-01

    The front IR quadrupole absorbers (TAS) and the IR neutral particle absorbers (TAN) in the high luminosity insertions of the Large Hadron Collider (LHC) each absorb approximately 1.8 TeV of forward collision products on average per pp interaction (~235 W at design luminosity 10/sup 34/ cm/sup -2/ s/sup -1/). This secondary particle flux can be exploited to provide a useful storage ring operations tool for optimization of luminosity. A novel segmented, multi-gap, pressurized gas ionization chamber is being developed for sampling the energy deposited near the maxima of the hadronic/electromagnetic showers in these absorbers. The system design choices have been strongly influenced by optimization of signal to noise ratio and by the very high radiation environment. The ionization chambers are instrumented with low noise, fast, pulse shaping electronics to be capable of resolving individual bunch crossings at 40 MHz. Data on each bunch are to be separately accumulated over multiple bunch crossings until the desire...

  8. Initial-state parton shower kinematics for NLO event generators

    International Nuclear Information System (INIS)

    Odaka, Shigeru; Kurihara, Yoshimasa

    2007-01-01

    We are developing a consistent method to combine tree-level event generators for hadron collision interactions with those including one additional QCD radiation from the initial-state partons, based on the limited leading-log (LLL) subtraction method, aiming at an application to NLO event generators. In this method, a boundary between non-radiative and radiative processes necessarily appears at the factorization scale (μ F ). The radiation effects are simulated using a parton shower (PS) in non-radiative processes. It is therefore crucial in our method to apply a PS which well reproduces the radiation activities evaluated from the matrix-element (ME) calculations for radiative processes. The PS activity depends on the applied kinematics model. In this paper we introduce two models for our simple initial-state leading-log PS: a model similar to the 'old' PYTHIA-PS and a p T -prefixed model motivated by ME calculations. PS simulations employing these models are tested using W-boson production at LHC as an example. Both simulations show a smooth matching to the LLL subtracted W+1 jet simulation in the p T distribution of W bosons, and the summed p T spectra are stable against a variation of μ F , despite that the p T -prefixed PS results in an apparently harder p T spectrum. (orig.)

  9. Characteristics of a Trigger Counter for Electromagnetic-Showers

    International Nuclear Information System (INIS)

    Abdou, Y.; Boundouk, I.I.; Badran, H.M.; Sharshar, T.; Badran, H.M.

    2000-01-01

    An electromagnetic-shower trigger counter composes of two identical thin scintillation detectors was constructed for investigating the density and time performance of the large area scintillation counter. An NE-102 A plastic scintillator with the thickness of 0.5 cm and area of 7.6 x 7.6 cm 2 is used to construct the detectors. The possibility of enhancing scintillation counter performance by the addition of absorber is also examined. The maximum increase in the density due to the addition of lead absorber was found to be at 0.9 and 1.5 r.l. for threshold energy of 2 and 16 MeV, respectively. The signals from the large area scintillation counter was found to be delayed as the hit position of the cosmic-ray particles moves away from the center of the scintillator. The delay is increasing by 0.24 and 0.17 nsec/cm for light enclosure height of 7.8 and 5.5 cm, respectively

  10. Experimental study of flow through compressor Cascade

    Directory of Open Access Journals (Sweden)

    Satyam Panchal

    2017-09-01

    Full Text Available The objective of this research work is to study the behaviour of flow at the inlet, within the blade passage and at the exit of a compressor cascade. For this purpose, a cascade with six numbers of aerofoil blades was designed and constructed. The cascade was fitted on the cascade test tunnel. Out of six blades two were instrumented for measuring the pressure distribution on the pressure and suction surface. The blades had a parabolic camber line, with a maximum camber position at 40% of the chord from the leading edge of the blade. The profile of the blade was C4, height of the blade was 160 mm, chord length was 80 mm, camber angle was 45° and stagger angle was 30°. Similarly, the length of the cascade was 300 mm, span was 160 mm, pitch was 60 mm, the actual chord of the cascade was 80 mm, the axial chord of the cascade was 70 mm, the stagger angle of the cascade was 30° and the pitch-chord ratio was 0.75. The data was taken and analyzed at −500% of the axial chord before the cascade, −25% of the axial chord before the leading edge, 25%, 50%, 75% and 150% of the axial chord from the leading edge of the blade. The readings were taken from the cascade wall to the mid span position along the pitch wise direction. The angle of incidence was also changed during the experiment and varied from i=−50°, −30°, −10° to 5°.

  11. Collision cascades in Zr3Fe

    International Nuclear Information System (INIS)

    Howe, L.M.; Rainville, M.H.; Phillips, D.; Plattner, H.H.; Bonnett, J.D.

    1994-11-01

    The objective of the present research is to understand better the processes that control irradiation-induced phase changes and solute segregation in zirconium alloys. Previously, it was found that 0.5 - 1.5 MeV 40 Ar ion irradiations resulted in the conversion of the crystalline Zr 3 Fe orthorhombic phase to the amorphous state. In the present investigation, 15 - 1500 keV 209 Bi ion irradiations (10 11 - 10 14 ions cm -2 ) were performed to provide more detailed information on collision cascades in Zr 3 Fe. Consecutive ion bombardments with 1.5, 1.0 and 0.5 MeV 209 Bi ions showed that complete amorphization occurred from 35 K to at least 600 K. Low fluence (10 11 - 101 12 ions cm -2 ) irradiations performed at 35 - 40 K with 15 - 350 keV 209 Bi ions provided information on the nature of the damage produced within individual damage cascades. At high values for the average deposited-energy density θυ in the cascade, which correspond to low-energy heavy-ion implants (e.g., 15-30 keV in Zr 3 Fe), the visible damage produced in a cascade consisted of single damaged region. With decreasing values of θυ (i.e., increasing ion implant energies), there was an increasing tendency for multiple damaged regions (subcascades) to form within a main cascade. The visible damaged regions appeared to be amorphous. It was also found that as the Bi ion energy increased (θυ decreased), the fraction of the theoretical collision-cascade volume that was occupied by the visible damage regions within a cascade decreased rapidly. The crystalline-to-amorphous transformation appeared to be the result of direct amorphization within the collision cascades and a critical defect concentration being reached in the cascade overlap regions, thus producing additional amorphous regions. (author). 30 refs., 2 tabs., 3 figs

  12. Cascade Baryon Spectrum from Lattice QCD

    International Nuclear Information System (INIS)

    Mathur, Nilmani; Bulava, John; Edwards, Robert; Engelson, Eric; Joo, Balint; Lichtl, Adam; Lin, Huey-Wen; Morningstar, Colin; Richards, David; Wallace, Stephen

    2008-01-01

    A comprehensive study of the cascade baryon spectrum using lattice QCD affords the prospect of predicting the masses of states not yet discovered experimentally, and determining the spin and parity of those states for which the quantum numbers are not yet known. The study of the cascades, containing two strange quarks, is particularly attractive for lattice QCD in that the chiral effects are reduced compared to states composed only of u/d quarks, and the states are typically narrow. We report preliminary results for the cascade spectrum obtained by using anisotropic Nf = 2 Wilson lattices with temporal lattice spacing 5.56 GeV?1.

  13. On Micro VAX farms and shower libraries: Monte Carlo techniques developed for the D0 detector

    International Nuclear Information System (INIS)

    Raja, R.

    1988-01-01

    In order to predict correctly the effects of cracks and dead material in a nearly hermetic calorimeter, hadronic and electromagnetic showers need to be simulated accurately on a particle by particle basis. Tracking all the particles of all showers in the calorimeter leads to very large CPU times (typically 5 hours on a VAX780) for events at √(s) = 2TeV. Parametrizing the energy deposition of electromagnetic particles in showers with energy below 200 MeV results in event times of the order of 1 hour on a VAX780. This is still unacceptably large. The D0 collaboration then employed a farm of 16 MicroVax II's to get acceptable throughputs. The calorimeter hit patterns of each individual track was output, to be summed up by a later job. These individual hit patterns were entered into a random access shower library file, which was then used for subsequent Monte Carlo simulations. This shower library technique results in further speed-ups of a factor of 60 without degrading the quality of simulation significantly

  14. Simulating Terrestrial Gamma Ray Flashes due to cosmic ray shower electrons and positrons

    Science.gov (United States)

    Connell, Paul

    2017-04-01

    The University of Valencia has developed a software simulator LEPTRACK to simulate the relativistic runaway electron avalanches, RREA, that are presumed to be the cause of Terrestrial Gamma Ray Flashes and their powerful accompanying Ionization/Excitation Flashes. We show here results of LEPTRACK simulations of RREA by the interaction of MeV energy electrons/positrons and photons in cosmic ray showers traversing plausible electric field geometries expected in storm clouds. The input beams of MeV shower products were created using the CORSIKA software package from the Karlsruhe Institute of Technology. We present images, videos and plots showing the different Ionization, Excitation and gamma-ray photon density fields produced, along with their time and spatial profile evolution, which depend critically on where the line of shower particles intercept the electric field geometry. We also show a new effect of incoming positrons in the shower, which make up a significant fraction of shower products, in particular their apparent "orbiting" within a high altitude negative induced shielding charge layer, which has been conjectured to produce a signature microwave emission, as well as a short range 511 keV annihilation line. The interesting question posed is if this conjectured positron emission can be observed and correlated with TGF orbital observations to show if a TGF originates in the macro E-fields of storm clouds or the micro E-fields of lightning leaders where this positron "orbiting" is not likely to occur.

  15. Fγ: A new observable for photon-hadron discrimination in hybrid air shower events

    Science.gov (United States)

    Niechciol, M.; Risse, M.; Ruehl, P.; Settimo, M.; Younk, P. W.; Yushkov, A.

    2018-01-01

    To search for ultra-high-energy photons in primary cosmic rays, air shower observables are needed that allow a good separation between primary photons and primary hadrons. We present a new observable, Fγ, which can be extracted from ground-array data in hybrid events, where simultaneous measurements of the longitudinal and the lateral shower profile are performed. The observable is based on a template fit to the lateral distribution measured by the ground array with the template taking into account the complementary information from the measurement of the longitudinal profile, i.e. the primary energy and the geometry of the shower. Fγ shows a very good photon-hadron separation, which is even superior to the separation given by the well-known Xmax observable (the atmospheric depth of the shower maximum). At energies around 1 EeV (10 EeV), Fγ provides a background rejection better than 97.8 % (99.9 %) at a signal efficiency of 50 %. Advantages of the observable Fγ are its technical stability with respect to irregularities in the ground array (i.e. missing or temporarily non-operating stations) and that it can be applied over the full energy range accessible to the air shower detector, down to its threshold energy. Furthermore, Fγ complements nicely to Xmax such that both observables can well be combined to achieve an even better discrimination power, exploiting the rich information available in hybrid events.

  16. Radio morphing - towards a full parametrisation of the radio signal from air showers

    Science.gov (United States)

    Zilles, A.; Charrier, D.; Kotera, K.; Le Coz, S.; Martineau-Huynh, O.; Medina, C.; Niess, V.; Tueros, M.; de Vries, K.

    2017-12-01

    Over the last decades, radio detection of air showers has been established as a detection technique for ultra-high-energy cosmic-rays impinging on the Earth's atmosphere with energies far beyond LHC energies. Today’s second-generation of digital radio-detection experiments, as e.g. AERA or LOFAR, are becoming competitive in comparison to already standard techniques e.g. fluorescence light detection. Thanks to a detailed understanding of the physics of the radio emission in extensive air showers, simulations of the radio signal are already successfully tested and applied in the reconstruction of cosmic rays. However the limits of the computational power resources are easily reached when it comes to computing electric fields at the numerous positions requested by large or dense antenna arrays. In the case of mountainous areas as e.g. for the GRAND array, where 3D shower simulations are necessary, the problem arises with even stronger acuity. Therefore we developed a full parametrisation of the emitted radio signal on the basis of generic shower simulations which will reduce the simulation time by orders of magnitudes. In this talk we will present this concept after a short introduction to the concept of the radio detection of air-shower induced by cosmic rays.

  17. Domestic shower hose biofilms contain fungal species capable of causing opportunistic infection.

    Science.gov (United States)

    Moat, John; Rizoulis, Athanasios; Fox, Graeme; Upton, Mathew

    2016-10-01

    The domestic environment can be a source of pathogenic bacteria. We show here that domestic shower hoses may harbour potentially pathogenic bacteria and fungi. Well-developed biofilms were physically removed from the internal surface of shower hoses collected in four locations in England and Scotland. Amplicon pyrosequencing of 16S and 18S rRNA targets revealed the presence of common aquatic and environmental bacteria, including members of the Actinobacteria, Alphaproteobacteria, Bacteroidetes and non-tuberculous Mycobacteria. These bacteria are associated with infections in immunocompromised hosts and are widely reported in shower systems and as causes of water-acquired infection. More importantly, this study represents the first detailed analysis of fungal populations in shower systems and revealed the presence of sequences related to Exophiala mesophila, Fusarium fujikuroi and Malassezia restricta. These organisms can be associated with the environment and healthy skin, but also with infection in compromised and immuno-competent hosts and occurrence of dandruff. Domestic showering may result in exposure to aerosols of bacteria and fungi that are potentially pathogenic and toxigenic. It may be prudent to limit development of these biofilms by the use of disinfectants, or regular replacement of hoses, where immuno-compromised persons are present.

  18. Bed and shower baths: comparing the perceptions of patients with acute myocardial infarction.

    Science.gov (United States)

    Lopes, Juliana L; Nogueira-Martins, Luiz A; de Barros, Alba Lbl

    2013-03-01

    To compare the perceptions of patients with acute myocardial infarction concerning bed and shower baths and evaluate how antecedent variables influence their perceptions. Professionals are often oblivious to the fact that, when performing a bed bath, they are manipulating someone else's body and invading someone's privacy and intimacy. This lack of awareness may trigger various responses in patients, such as dissatisfaction and anxiety. Several studies assessing the perceptions of patients when receiving a bed bath, and most are qualitative. Thus, there is a need to quantify these perceptions. The research was a crossover study. The sample consisted of 71 patients with acute myocardial infarction, admitted to coronary units. Patients were evaluated on two occasions: after their second bed bath and after their second shower bath. A Semantic Differential Scale was constructed and validated prior to data collection. The perception of patients receiving shower baths was significantly more positive than those of patients receiving bed baths (shower baths, than those who were hospitalised for the first time. The perceptions of patients receiving bed baths were less positive than those of patients receiving shower baths. The perceptions of patients receiving baths are very important to guiding nursing care and developing strategies to minimise patient dissatisfaction. © 2012 Blackwell Publishing Ltd.

  19. Which cleansing care is better, foot bath or shower? Analysis of 236 limb ulcers.

    Science.gov (United States)

    Sano, Hitomi; Ichioka, Shigeru

    2015-10-01

    Foot baths and showering are two widely used methods to cleanse limb ulcers. However, some clinicians warn that foot baths may contribute to the spread of infection at the ulcer site. This study aimed to retrospectively investigate the relationship between cleansing methods and the limb prognoses of 236 patients with chronic limb ulcers. These patients were divided into two groups according to the method used to cleanse their ulcers, foot bath and showering. Limb prognosis, including loss of all toes and major amputation, was retrospectively analysed. The rates of loss of all toes and major amputation were 53·0% and 30% in the foot bath group, and 35·3% and 18·4% in the showering group, respectively. The rates of loss of all toes (adjusted odds ratios = 2·07; P = 0·0066; 95% confidence intervals, 1·22-3·50) and major amputation (adjusted odds ratio = 1·90; P = 0·037; 95% confidence intervals, 1·03-3·50) were significantly higher in the foot bath group than those in the showering group. Our results demonstrate that showering is preferable to foot baths for the cleansing of chronic limb ulcers. Clinicians should be cautious that inappropriate cleansing may cause ulcer infections to spread. © 2013 The Authors. International Wound Journal © 2013 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

  20. Showering effectiveness for human hair decontamination of the nerve agent VX.

    Science.gov (United States)

    Josse, Denis; Wartelle, Julien; Cruz, Catherine

    2015-05-05

    In this work, our goals were to establish whether hair decontamination by showering one hour post-exposure to the highly toxic organophosphate nerve agent VX was effective, whether it required the addition of a detergent to water and, if it could be improved by using the adsorbent Fuller's Earth (FE) or the Reactive Skin Decontamination Lotion (RSDL) 30 min prior to showering. Hair exposure to VX and decontamination was performed by using an in vitro model. Hair showering led to 72% reduction of contamination. Addition of detergent to water slightly increased the decontamination effectiveness. Hair treatment with FE or RSDL improved the decontamination rate. Combination of FE use and showering, which yielded a decontamination factor of 41, was demonstrated to be the most effective hair decontamination procedure. Hair wiping after showering was shown to contribute to hair decontamination. Altogether, our results highlighted the importance of considering hair decontamination as an important part of body surface decontamination protocols. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  1. Investigating cosmic rays and air shower physics with IceCube/IceTop

    Directory of Open Access Journals (Sweden)

    Dembinski Hans

    2017-01-01

    Full Text Available IceCube is a cubic-kilometer detector in the deep ice at South Pole. Its square-kilometer surface array, IceTop, is located at 2800 m altitude. IceTop is large and dense enough to cover the cosmic-ray energy spectrum from PeV to EeV energies with a remarkably small systematic uncertainty, thanks to being close to the shower maximum. The experiment offers new insights into hadronic physics of air showers by observing three components: the electromagnetic signal at the surface, GeV muons in the periphery of the showers, and TeV muons in the deep ice. The cosmic-ray flux is measured with the surface signal. The mass composition is extracted from the energy loss of TeV muons observed in the deep ice in coincidence with signals at the surface. The muon lateral distribution is obtained from GeV muons identified in surface signals in the periphery of the shower. The energy spectrum of the most energetic TeV muons is also under study, as well as special events with laterally separated TeV muon tracks which originate from high-pT TeV muons. A combination of all these measurements opens the possibility to perform powerful new tests of hadronic interaction models used to simulate air showers. The latest results will be reviewed from this perspective.

  2. Jet Hadronization via Recombination of Parton Showers in Vacuum and in Medium

    Energy Technology Data Exchange (ETDEWEB)

    Fries, Rainer J.; Han, Kyongchol; Ko, Che Ming

    2016-12-15

    We introduce a hadronization algorithm for jet parton showers based on a hybrid approach involving recombination of quarks and fragmentation of strings. The algorithm can be applied to parton showers from a shower Monte Carlo generator at the end of their perturbative evolution. The algorithm forces gluon decays and then evaluates the recombination probabilities for quark-antiquark pairs into mesons and (anti)quark triplets into (anti)baryons. We employ a Wigner phase space formulation based on the assumption of harmonic oscillator wave functions for stable hadrons and resonances. Partons too isolated in phase space to find recombination partners are connected by QCD strings to other quarks. Fragmentation of those remnant strings and the decay of all hadron resonances complete the hadronization process. We find that our model applied to parton showers from the PYTHIA Monte Carlo event generator leads to results very similar to pure Lund string fragmentation. We suggest that our algorithm can be readily generalized to jets embedded in quark-gluon plasma by adding sampled thermal partons from the phase transition hypersurface. The recombination of thermal partons and shower partons leads to an enhancement of pions and protons at intermediate momentum at both RHIC and LHC.

  3. Extensive Air Showers Detected by Aragats Neutron Monitor

    International Nuclear Information System (INIS)

    Badalyan, A.; Chilingarian, A.; Hovsepyan, G.; Grigoryan, A.; Khanikyants, Y.; Manukyan, A.; Pokhsraryan, D.; Soghomonyan, S.

    2017-01-01

    Extensive Air Shower (EAS) duration as registered by the surface particle detectors does not exceed a few tens of nanosecond. However, Neutron monitors containing plenty of absorbing matter can respond to EAS core traversal during 1 ∼ms by registering secondary slow neutrons born by EAS hadrons in the soil, walls of buildings and in the matter of detector itself. Thus, the time distribution of the pulses from the proportional counters of the neutron monitor after EAS propagation extends to ∼l ms, ∼5 orders of magnitude larger than the EAS passing time. The Aragats Neutron Monitor (ArNM) has a special option for the EAS core detection. In general, the dead time of NM is ∼1 ms that provides the one-to-one relation of incident hadrons and detector counts. The pulses generated by the neutrons possibly entering the proportional chamber after the first one will be neglected. In ArNM, we use several “electronic” dead times, and with the shortest one, 400 ns, the detector counts all pulses that enter the proportional chambers. If ArNM one-second time series corresponding to the shortest dead time contain much more signals (a neutron burst) than with l-ms dead time, then we conclude that the EAS core hits the detector. We assume that he distribution of registered burst multiplicities is proportional to the energy of the primary particle. The primary cosmic ray energy spectrum was obtained by the frequency analysis through the counting frequencies of the multiplicities of different magnitudes and relating them to the integral energy spectrum measured by the MAKET array at the same place several years ago. (author)

  4. Chloramine-induced anaphylaxis while showering: a case report

    Directory of Open Access Journals (Sweden)

    D’Alò Simona

    2012-09-01

    Full Text Available Abstract Introduction Sodium-N-chlorine-p-toluene sulfonamide, commonly known as chloramine-T, is a derivative of chlorine which is widely used as a disinfectant. For many years, chloramine-T has been described as a cause of immediate-type hypersensitivity, especially with regard to asthma and rhinitis, and as a cause of occupational dermatoses in cleaning personnel in hospitals, although no anaphylactic reaction has yet been reported. Hence, to the best of our knowledge we present the first case of anaphylaxis to chloramine-T with evidence of specific immunoglobulin E antibodies. Case presentation We describe the case of a 25-year-old Caucasian woman who was in good health and with a negative history for atopy, including no respiratory symptoms of rhinitis or asthma, and with no professional exposure to chloramine-T. She, while showering, applied a chloramine-T solution to a skin area with folliculitis on her leg, and within a few minutes developed generalized urticaria and angioedema, followed by vomiting and collapse with loss of consciousness. A skin prick test with a chloramine-T solution at 10mg/mL concentration was positive, and specific immunoglobulin E to chloramine-T was quantified at a value of 2.9 optical density as measured by the enzyme allergosorbent test technique. Conclusion The strict cause-effect relationship and the results of the skin test and the in vitro test make certain the causative role of chloramine-T in this case of anaphylaxis. This suggests that chloramine-T, based on its wide use as a disinfectant, should be considered a possible cause in anaphylaxis of unknown origin.

  5. Shower approach in the simulation of ion scattering from solids.

    Science.gov (United States)

    Khodyrev, V A; Andrzejewski, R; Rivera, A; Boerma, D O; Prieto, J E

    2011-05-01

    An efficient approach for the simulation of ion scattering from solids is proposed. For every encountered atom, we take multiple samples of its thermal displacements among those which result in scattering with high probability to finally reach the detector. As a result, the detector is illuminated by intensive "showers," where each event of detection must be weighted according to the actual probability of the atom displacement. The computational cost of such simulation is orders of magnitude lower than in the direct approach, and a comprehensive analysis of multiple and plural scattering effects becomes possible. We use this method for two purposes. First, the accuracy of the approximate approaches, developed mainly for ion-beam structural analysis, is verified. Second, the possibility to reproduce a wide class of experimental conditions is used to analyze some basic features of ion-solid collisions: the role of double violent collisions in low-energy ion scattering; the origin of the "surface peak" in scattering from amorphous samples; the low-energy tail in the energy spectra of scattered medium-energy ions due to plural scattering; and the degradation of blocking patterns in two-dimensional angular distributions with increasing depth of scattering. As an example of simulation for ions of MeV energies, we verify the time reversibility for channeling and blocking of 1-MeV protons in a W crystal. The possibilities of analysis that our approach offers may be very useful for various applications, in particular, for structural analysis with atomic resolution. © 2011 American Physical Society

  6. Aspects of the QCD cascade

    International Nuclear Information System (INIS)

    Olsson, Magnus.

    1993-02-01

    A model is proposed for the production of transverse jets from diffractively excited protons. We propose that transverse jets can be obtained from gluonic bremsstrahlung in a way similar to the emission in DIS. Qualitative agreement is obtained between the model and the uncorrected data published by the UA8 collaboration. Perturbative QCD in the MLLA approximation is applied to multiple jet production in e + e - -annihilation. We propose modified evolution equations for deriving the jet cross sections, defined in the 'k t ' or 'Durham' algorithm. The mean number of jets as a function of the jet resolution is studied, and analytical predictions are compared to the results of MC simulations. We also study a set of differential-difference equations for multiplicity distributions in e + e - -annihilations, supplemented with appropriate boundary conditions. These equations take into account nonsingular terms in the GLAP splitting functions as well as kinematical constraints related to recoil effects. The presence of retarded terms imply that the cascade develops more slowly and reduces the fluctuations. The solutions agree well with MC simulations and experimental data. (authors)

  7. Contribution to the calorimetry of the gamma-ray space telescope GLAST and a look at electro-photon cascades on the diffuse extragalactic photon background

    International Nuclear Information System (INIS)

    D'Avezac, Pol

    2006-01-01

    Starting September 2007, the Gamma Large Array Space Telescope (GLAST) will observe γ-rays of energy between 100 MeV and 300 GeV. A siliceous-strip tracker measures their direction and a calorimeter their energy. The latter is rendered hodoscopic thanks to the disposition of its CsI(Tl) crystals. Weighting 2 tons in all, these are inserted in an epoxy and carbon-ber structure for protection during take-off. Inside each crystal, tapering of the signal, coupled with double diodes at each end, allows for the measure of both the energy deposited in that crystal and the mean position of the deposit. On Earth, calibration occurs through the use of cosmic muons. Rays interact with the detector by creating electromagnetic showers. Because of constraints on the design of this space-based calorimeter, only a varying fraction of a shower's energy is deposited inside the calorimeter. This fraction depends on shower energy, direction and proximity to the detector's walls. The γ-ray energy (E) is reconstructed trough the optimisation of an estimator as a function of these parameters. The estimator is based on the energy deposited inside the calorimeter (Q) and observables which anti-correlate with Q when E is axed, thus reducing Q's variance. The reconstruction algorithm proceeds with a maximum likelihood on this estimator. Extragalactic γ-rays may initiate electron-photon cascades on the photon background. Observed spectra are a function of the ray attenuation, allowing in return for a measure of the infrared background, and cascade emissions. A spectral signature of the extragalactic magnetic field is considered. (author)

  8. Cascade theory in isotopic separation processes

    International Nuclear Information System (INIS)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs

  9. MAP kinase cascades in Arabidopsis innate immunity

    DEFF Research Database (Denmark)

    Rasmussen, Magnus Wohlfahrt; Roux, Milena Edna; Petersen, Morten

    2012-01-01

    Plant mitogen-activated protein kinase (MAPK) cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs) by host transmembrane pattern recognition receptors which trigger MAPK-dependent innate ...

  10. {tau} polarization in SUSY cascade decays

    Energy Technology Data Exchange (ETDEWEB)

    Choi, S.Y. [Chonbuk Univ., Jeonju (Korea), Dept. of Physics and RIPC]|[Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Hagiwara, K. [KEK National High Energy Physics, Tsukuba (Japan); Kim, Y.G. [Sejong Univ., Seoul (Korea). ARCSEC; Mawatari, K. [Korea Institute for Advanced Study, Seoul (Korea). School of Physics; Zerwas, P.M. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)]|[KEK National High Energy Physics, Tsukuba (Japan)

    2006-12-15

    {tau} leptons emitted in cascade decays of supersymmetric particles are polarized. The polarization may be exploited to determine spin and mixing properties of the neutralinos and stau particles involved. (orig.)

  11. Cascade Error Projection: A New Learning Algorithm

    Science.gov (United States)

    Duong, T. A.; Stubberud, A. R.; Daud, T.; Thakoor, A. P.

    1995-01-01

    A new neural network architecture and a hardware implementable learning algorithm is proposed. The algorithm, called cascade error projection (CEP), handles lack of precision and circuit noise better than existing algorithms.

  12. High energy evolution of soft gluon cascades

    International Nuclear Information System (INIS)

    Shuvaev, A.; Wallon, S.

    2006-01-01

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  13. High energy evolution of soft gluon cascades

    Energy Technology Data Exchange (ETDEWEB)

    Shuvaev, A. [St. Petersburg Nuclear Physics Institute, Gatchina, St. Petersburg district (Russian Federation); Wallon, S. [Universite Paris XI, Laboratoire de Physique Theorique, Orsay Cedex (France)

    2006-04-15

    In this paper we derive an evolution equation for the gluon density in soft gluon cascades emitted from any colored source, in the leading logarithmic approximation of perturbative QCD. We show that this equation has the same form as the BFKL equation in the forward case. An explicit expression for the total cascade wavefunction involving an arbitrary number of soft gluons is obtained. Renormalization of the colored source wavefunction turns out to be responsible for the reggeization of the source. (orig.)

  14. Compression limits in cascaded quadratic soliton compression

    DEFF Research Database (Denmark)

    Bache, Morten; Bang, Ole; Krolikowski, Wieslaw

    2008-01-01

    Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency.......Cascaded quadratic soliton compressors generate under optimal conditions few-cycle pulses. Using theory and numerical simulations in a nonlinear crystal suitable for high-energy pulse compression, we address the limits to the compression quality and efficiency....

  15. Cascade of links in complex networks

    International Nuclear Information System (INIS)

    Feng, Yeqian; Sun, Bihui; Zeng, An

    2017-01-01

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  16. Cascade of links in complex networks

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Yeqian; Sun, Bihui [Department of Management Science, School of Government, Beijing Normal University, 100875 Beijing (China); Zeng, An, E-mail: anzeng@bnu.edu.cn [School of Systems Science, Beijing Normal University, 100875 Beijing (China)

    2017-01-30

    Cascading failure is an important process which has been widely used to model catastrophic events such as blackouts and financial crisis in real systems. However, so far most of the studies in the literature focus on the cascading process on nodes, leaving the possibility of link cascade overlooked. In many real cases, the catastrophic events are actually formed by the successive disappearance of links. Examples exist in the financial systems where the firms and banks (i.e. nodes) still exist but many financial trades (i.e. links) are gone during the crisis, and the air transportation systems where the airports (i.e. nodes) are still functional but many airlines (i.e. links) stop operating during bad weather. In this letter, we develop a link cascade model in complex networks. With this model, we find that both artificial and real networks tend to collapse even if a few links are initially attacked. However, the link cascading process can be effectively terminated by setting a few strong nodes in the network which do not respond to any link reduction. Finally, a simulated annealing algorithm is used to optimize the location of these strong nodes, which significantly improves the robustness of the networks against the link cascade. - Highlights: • We propose a link cascade model in complex networks. • Both artificial and real networks tend to collapse even if a few links are initially attacked. • The link cascading process can be effectively terminated by setting a few strong nodes. • A simulated annealing algorithm is used to optimize the location of these strong nodes.

  17. A background-free detector for cosmic ray showers in the atmosphere

    International Nuclear Information System (INIS)

    Menzione, A.; Angelini, F.; Bedeschi, F.; Bellazzini, R.; Bertolucci, E.; Chiarelli, G.; Mariotti, M.; Massai, M.M.; Smith, D.A.; Stefanini, A.; Zetti, F.; Anassontzis, E.; Resvanis, L.; Voulgaris, G.; Ypsilantis, T.; Tripp, R.; Torres, S.; Biral, A.R.P.; Chinellato, J.A.; Turtelli, A.; Bartoli, B.; Sinnis, G.; Weekes, D.; Cresti, M.; Peruzzo, L.; Pesci, A.; Saggion, A.; Sartori, G.; Luksys, M.; Chuang, K.W.; Kerrick, A.; O'Neil, T.J.; Tumer, T.; Zych, A.D.; Bicchi, P.; Meucci, M.; Moi, L.; Paoletti, R.; Rigato, M.; Scribano, A.; Budinich, M.; Liello, F.; Milotti, E.; Cence, R.J.; Hayes, C.; Hudson, J.; Kelley, L.; Learned, J.G.; Paluselli, D.; Stenger, V.J.

    1992-01-01

    A detector of new design is planned to detect Cherenkov light in high energy cosmic ray showers. It is based on the detection of the middle-UV radiation by TMAE photosensitive chambers, giving detailed imaging of the shower, combined with the beneficial background screening of the ozone in the upper atmosphere. This allows us to greatly improve the duty-cycle, the sensitivity and the range of observations with respect to traditional Cherenkov experiments in the visible. A further advantage is the achievable big angular aperture which makes it possible to search for new sources with an efficiency similar to extensive air shower experiments. Details of the technique and achievable physics goals are presented. (orig.)

  18. Detection of ultraviolet Cherenkov light from high energy cosmic ray atmospheric showers: A field test

    International Nuclear Information System (INIS)

    Bartoli, B.; Peruzzo, L.; Sartori, G.; Bedeschi, F.; Bertolucci, E.; Mariotti, M.; Menzione, A.; Ristori, L.; Stefanini, A.; Zetti, F.; Scribano, A.; Budinich, M.; Liello, F.

    1991-01-01

    We present the results of a test with a prototype apparatus aimed to detect the ultraviolet Cherenkov light in the wavelenght range 2000-2300A, emitted by high energy cosmic ray showers. The system consists of a gas proportional chamber, with TMAE vapour as the photosensitive element, placed on the focal plane of a 1.5 m diameter parabolic mirror. The test was done during the summer of 1989 with cosmic ray showers seen in coincidence with the EAS-TOP experiment, an extended atmospheric shower charged particle array now being exploited at Campo Imperatore, 1900 m above sea level, on top of the Gran Sasso underground Laboratory of INFN. The results were positive and show that a full scale ultraviolet Cherenkov experiment with good sensitivity, angular resolution and virtually no background from moonlight or even daylight can be envisaged. (orig.)

  19. Comparing levels of anxiety during bed and shower baths in patients with acute myocardial infarction.

    Science.gov (United States)

    Lopes, Juliana de Lima; Nogueira-Martins, Luiz Antonio; Gonçalves, Maria Aparecida Batistão; de Barros, Alba Lucia Bottura Leite

    2010-01-01

    This study compared the levels of anxiety presented by patients with acute myocardial infarction in bed and shower baths and the influence of antecedent variables: age, gender, medications, previous hospitalization and/or bed bath, patients' preference regarding the professional's gender, risk factors and anxiety-traits. This crossover study was conducted between February and August 2007 in coronary units. The sample was composed of 71 patients with acute myocardial infarction. The State-Trait Anxiety Inventory (STAI) was applied before the baths (bed and shower baths), immediately after the baths and twenty minutes after the second evaluation. Results revealed that patients were more anxious in the bed bath than in the shower in the three assessments (p <0.0001) and the only variable that interfered with state-anxiety was high blood pressure.

  20. Multiple lacerations in a pregnant woman caused by spontaneously exploding shower screen glass.

    Science.gov (United States)

    Søreide, Kjetil; Søreide, Annbjørg Hegelstad

    2008-11-01

    Injuries caused by glass occur frequently, in particular in children, and make up an estimated 3% to 5% of all emergency visits, most frequently involving lacerations of hands, feet, and face. About 30% to 40% of glass injuries occur at home and often involve so-called architectural glass or bottles and glass containers. Accidents reported in association with showering mostly refer to falls or scalding by hot water. However, an increasing number of shower screens are made of tempered glass, which may potentially brake. Such injuries may be potentially severe, causing laceration of extremity arteries; requiring hospitalization or outpatient treatment for injuries; causing absence from work. These injuries are likely underreported in the medical literature but could have potential medicolegal consequences for the patient. We report a case of multiple lacerations developed in a third-trimester pregnant woman caused by the spontaneous shattering of a shower screen glass and discuss the apparent unawareness to this potential hazard in the scientific literature.

  1. The influence of the atmospheric refractive index on radio Xmax measurements of air showers

    Directory of Open Access Journals (Sweden)

    Corstanje Arthur

    2017-01-01

    Full Text Available The refractive index of the atmosphere, which is n ≈ 1:0003 at sea level, varies with altitude and with local temperature, pressure and humidity. When performing radio measurements of air showers, natural variations in n will change the radio lateral intensity distribution, by changing the Cherenkov angle. Using CoREAS simulations, we have evaluated the systematic error on measurements of the shower maximum Xmax due to variations in n. It was found that a 10% increase in refractivity (n – 1 leads to an underestimation of Xmax between 8 and 22 g/cm2 for proton-induced showers at zenith angles from 15 to 45 degrees, respectively.

  2. A parameterized energy correction method for electromagnetic showers in BGO-ECAL of DAMPE

    Science.gov (United States)

    Yue, Chuan; Zang, Jingjing; Dong, Tiekuang; Li, Xiang; Zhang, Zhiyong; Zimmer, Stephan; Jiang, Wei; Zhang, Yunlong; Wei, Daming

    2017-06-01

    DAMPE is a space-based mission designed as a high energy particle detector measuring cosmic-rays and γ-rays which was successfully launched on Dec.17, 2015. The BGO electromagnetic calorimeter is one of the key sub-detectors of DAMPE for energy measurement of electromagnetic showers produced by e± / γ . Due to energy loss in dead material and energy leakage outside the calorimeter, the deposited energy in BGO underestimates the primary energy of incident e± / γ . In this paper, based on detailed MC simulations, a parameterized energy correction method using the lateral and longitudinal information of electromagnetic showers has been studied and verified with data of electron beam test at CERN. The measurements of energy linearity and resolution are significant improved by applying this correction method for electromagnetic showers.

  3. Precision Timing with shower maximum detectors based on pixelated micro-channel plates

    Science.gov (United States)

    Bornheim, A.; Apresyan, A.; Ronzhin, A.; Xie, S.; Spiropulu, M.; Trevor, J.; Pena, C.; Presutti, F.; Los, S.

    2017-11-01

    Future calorimeters and shower maximum detectors at high luminosity colliders need to be highly radiation resistant and very fast. One exciting option for such a detector is a calorimeter composed of a secondary emitter as the active element. In this report we outline the study and development of a secondary emission calorimeter prototype using micro-channel plates (MCP) as the active element, which directly amplify the electromagnetic shower signal. We demonstrate the feasibility of using a bare MCP within an inexpensive and robust housing without the need for any photo cathode, which is a key requirement for high radiation tolerance. Test beam measurements of the prototype were performed with 120 GeV primary protons and secondary beams at the Fermilab Test Beam Facility, demonstrating basic calorimetric measurements and precision timing capabilities. Using multiple pixel readout on the MCP, we demonstrate a transverse spatial resolution of 0.8 mm, and time resolution better than 40 ps for electromagnetic showers.

  4. Muon study for gamma/hadron air-shower discrimination in the HAWC observatory

    Science.gov (United States)

    Zuñiga Reyes, A.; Hernández Almada, A.; Sandoval Espinosa, A.; HAWC Collaboration

    2017-07-01

    The High-Altitude Water Cherenkov observatory is a ground-based array designed to study energetic gamma-rays. Experiments with this purpose have to face a huge rate of undesired hadronic background. Motivated by the fact that muon content is quite different in gamma-induced (poor in muons) and hadronic-induced (rich in muons) air-showers, we study the idea of formulating a new variable for background reduction related with counting the number of muons candidates present in such showers. Therefore, in this work we used the time differences between photomultipliers tubes to identify the signature of muons inside the water Cherenkov detectors. Showers with a high presence of muons typically must produce a characteristic time difference around 5 ns among the central detector (PMT_C) and each one of the laterals (PMT: A, B, D).

  5. Drell-Yan Production at NNLL'+NNLO Matched to Parton Showers

    CERN Document Server

    Alioli, Simone; Berggren, Calvin; Tackmann, Frank J; Walsh, Jonathan R

    2015-01-01

    We present results for Drell-Yan production from the GENEVA Monte-Carlo framework. We combine the fully-differential NNLO calculation with higher-order resummation in the 0-jettiness resolution variable. The resulting parton-level events are further combined with parton showering and hadronization provided by PYTHIA8. The 0-jettiness resummation is carried out to NNLL', which consistently incorporates all singular virtual and real NNLO corrections. It thus provides a natural perturbative connection between the NNLO calculation and the parton shower regime, including a systematic assessment of perturbative uncertainties. In this way, inclusive observables are correct to NNLO, up to small power corrections in the resolution cutoff. Furthermore, the perturbative accuracy of 0-jet-like resummation variables is significantly improved beyond the parton shower approximation. We provide comparisons with LHC measurements of Drell-Yan production at 7 TeV from ATLAS, CMS, and LHCb. As already observed in $e^+e^-$ collis...

  6. Extensive Air Shower Detector Array at the Universidad Autonoma de Puebla

    Science.gov (United States)

    Cotzomi, J.; Moreno, E.; Aguilar, S.; Palma, B.; Martinez, O.; Salazar, H.; Villasenor, L.

    2002-07-01

    We describe the operation of an Extensive Air Shower Array located at the campus of the FCFM-BUAP. The array consists of 8 liquid scintillation detectors with a surface of 1 m2 each and a detector spacing of 20 m in a square grid. The array was designed to measure the energy and arrival direction of primary particles that generate extensive air showers (EAS) in the region of 1013 eV - 1016 eV. The angular distribution measured with this array, Cos8(Theta) xSin(Theta), agrees very well with the literature. We also present the measured energies of a number of vertical showers in the range of 5 x1012 eV to 5 x1013 eV.

  7. Reconstruction of showers at TeV energy by the CLUE Experiment and its application to recent data

    International Nuclear Information System (INIS)

    Bartoli, B.; Cresti, M.; Mariotti, M.; Peruzzo, L.; Sacco, R.; Saggion, A.; Sartori, G.; Sbarra, C.; Bigongiari, C.; Cocca, E.; Lucchesi, D.; Marsella, G.; Menzione, A.; Paoletti, R.; Parlavecchio, G.; Scribano, A.; Stamerra, A.; Turini, N.; Zetti, F.; Liello, F.

    1999-01-01

    The CLUE UV Cerenkov telescope array has started to take data with 8 telescopes in January 1998. The UV Cerenkov images obtained by the CLUE experiment are very different with respect to the visible case, and a new method for reconstructing the shower direction has been worked out. The shower reconstruction is shown and an application to recent data is given

  8. Reconstruction of showers at TeV energy by the CLUE Experiment and its application to recent data

    Energy Technology Data Exchange (ETDEWEB)

    Bartoli, B.; Cresti, M.; Mariotti, M.; Peruzzo, L.; Sacco, R.; Saggion, A.; Sartori, G.; Sbarra, C.; Bigongiari, C.; Cocca, E.; Lucchesi, D.; Marsella, G.; Menzione, A.; Paoletti, R.; Parlavecchio, G.; Scribano, A.; Stamerra, A.; Turini, N.; Zetti, F.; Liello, F

    1999-03-01

    The CLUE UV Cerenkov telescope array has started to take data with 8 telescopes in January 1998. The UV Cerenkov images obtained by the CLUE experiment are very different with respect to the visible case, and a new method for reconstructing the shower direction has been worked out. The shower reconstruction is shown and an application to recent data is given.

  9. Comparison of Air Fluorescence and Ionization Measurements of E.M. Shower Depth Profiles: Test of a UHECR Detector Technique

    Energy Technology Data Exchange (ETDEWEB)

    Belz, J.; Cao, Z.; Huentemeyer, P.; Jui, C.C.H.; Martens, K.; Matthews, J.; Maestas, M.; Smith, J.; Sokolsky, P.; Springer, R.W.; Thomas, J.; Thomas, S.; /Utah U.; Chen,; Field, Clive; Hast, C.; Iverson, R.; Ng, J.S.T.; Odian, A.; Reil, K.; Vincke, H.; Walz, D.; /SLAC /Montana U. /Rutgers U., Piscataway /Taiwan, Natl. Taiwan U.

    2005-10-07

    Measurements are reported on the fluorescence of air as a function of depth in electromagnetic showers initiated by bunches of 28.5 GeV electrons. The light yield is compared with the expected and observed depth profiles of ionization in the showers. It validates the use of atmospheric fluorescence profiles in measuring ultra high energy cosmic rays.

  10. The cosmic-ray energy spectrum above 1016 eV measured with the LOFAR radboud air shower array

    NARCIS (Netherlands)

    Thoudam, S.; Buitink, S.; Corstanje, A.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; Ter Veen, S.; Trinh, T. N G; Van Kessel, L.

    2015-01-01

    The LOFAR Radboud Air Shower Array (LORA) is an array of 20 plastic scintillation detectors installed in the center of the LOFAR radio telescope in the Netherlands to measure extensive air showers induced by cosmic rays in the Earth's atmosphere. The primary goals of LORA are to trigger the read-out

  11. Empowering the surgical patient: a randomized, prospective analysis of an innovative strategy for improving patient compliance with preadmission showering protocol.

    Science.gov (United States)

    Edmiston, Charles E; Krepel, Candace J; Edmiston, Sarah E; Spencer, Maureen; Lee, Cheong; Brown, Kellie R; Lewis, Brian D; Rossi, Peter J; Malinowski, Michael; Seabrook, Gary

    2014-08-01

    Surgical site infections (SSIs) are responsible for significant morbidity, mortality, and excess use of health care resources. The preadmission antiseptic shower is accepted as an effective strategy for reducing the risk for SSIs. The study analyzes the benefit of an innovative electronic patient alert system (EAS) for enhancing compliance with a preadmission showering protocol with 4% chlorhexidine gluconate (CHG). After providing informed consent, 80 volunteers were randomized to 4 CHG showering groups. Groups A1 and A2 showered twice. Group A1 was prompted to shower via EAS. Groups B1 and B2 showered 3 times. Group B1 was prompted via EAS. Subjects in groups A2 and B2 were not prompted (non-EAS groups). Skin-surface concentrations of CHG (μg/mL) were analyzed using colorimetric assay at 5 separate anatomic sites. Study personnel were blinded to the randomization code; after final volunteer processing, the code was broken and individual groups were analyzed. Mean composite CHG skin-surface concentrations were significantly higher (p shower in all groups. The findings suggest that EAS was effective in enhancing patient compliance with a preadmission showering protocol, resulting in a significant (p < 0.007) increase in skin-surface concentrations of CHG compared with non-EAS controls. However, variation in amount of unused 4% CHG suggests that rigorous standardization is required to maximize the benefits of this patient-centric interventional strategy. Copyright © 2014 American College of Surgeons. Published by Elsevier Inc. All rights reserved.

  12. A measurement of the muon number in showers using inclined events detected at the Pierre Auger Observatory

    Directory of Open Access Journals (Sweden)

    Rodriguez G.

    2013-06-01

    Full Text Available The average muon content of measured showers with zenith angles between 62∘ and 80∘ detected at the Pierre Auger Observatory is obtained as a function of shower energy using a reconstruction method specifically designed for inclined showers and the hybrid character of the detector. The reconstruction of inclined showers relies on a comparison between the measured signals at ground and reference patterns at ground level from which an overall normalization factor is obtained. Since inclined showers are dominated by muons this factor gives the relative muon size. It can be calibrated using a subsample of showers simultaneously recorded with the fluorescence detector (FD and the surface detector (SD which provides an independent calorimetric measurement of the energy. The muon size obtained for each shower becomes a measurement of the relative number of muons with respect to the reference distributions. The precision of the measurement is assessed using simulated events which are reconstructed using exactly the same procedure. We compare the relative number of muons versus energy as obtained to simulations. Proton simulations with QGSJETII show a factor of 2.13 ± 0.04(stat ± 0.11(sys at 1019eV without significant variations in the energy range explored between 4 × 1018eV to 7 × 1019eV. We find that none of the current shower models, neither for proton nor for iron primaries, are able to predict as many muons as are observed.

  13. Influence of contrast shower and water immersion on recovery in elite netballers.

    Science.gov (United States)

    Juliff, Laura E; Halson, Shona L; Bonetti, Darrell L; Versey, Nathan G; Driller, Matthew W; Peiffer, Jeremiah J

    2014-08-01

    Contrast water therapy is a popular recovery modality in sport; however, appropriate facilities can often be difficult to access. Therefore, the present study examined the use of contrast showers as an alternative to contrast water therapy for team sport recovery. In a randomized, crossover design, 10 elite female netball athletes (mean ± SD: age, 20 ± 0.6 years; height, 1.82 ± 0.05 m; body mass, 77.0 ± 9.3 kg) completed 3 experimental trials of a netball specific circuit followed by one of the following 14-minute recovery interventions: (a) contrast water therapy (alternating 1 minute 38° C and 1 minute 15° C water immersion), (b) contrast showers (alternating 1 minute 38° C and 1 minute 18° C showers), or (c) passive recovery (seated rest in 20° C). Repeated agility, skin and core temperature, and perception scales were measured before, immediately after, 5 and 24 hours postexercise. No significant differences in repeated agility were evident between conditions at any time point. No significant differences in core temperature were observed between conditions; however, skin temperature was significantly lower immediately after contrast water therapy and contrast showers compared with the passive condition. Overall perceptions of recovery were superior after contrast water therapy and contrast showers compared with passive recovery. The findings indicate contrast water therapy and contrast showers did not accelerate physical recovery in elite netballers after a netball specific circuit; however, the psychological benefit from both interventions should be considered when determining the suitability of these recovery interventions in team sport.

  14. Risk from exposure to trihalomethanes during shower: probabilistic assessment and control.

    Science.gov (United States)

    Chowdhury, Shakhawat; Champagne, Pascale

    2009-02-15

    Exposure to trihalomethanes (THMs) through inhalation and dermal contact during showering and bathing may pose risks to human health. During showering and bathing, warm water (35 degrees C-45 degrees C) is generally used. Warming of chlorinated supply water may increase THMs formation through enhanced reactions between organics and residual chlorine. Exposure assessment using THMs concentrations in cold water may under-predict the possible risks to human health. In this study, THMs concentrations in warm water were estimated by developing a THMs formation rate model. Using THMs in warm water, cancer and non-cancer risks to human health were predicted for three major cities in Ontario (Canada). The parameters for risk assessments were characterized by statistical distributions. The total cancer risks from exposure to THMs during showering were predicted to be 7.6x10(-6), 6.3x10(-6) and 4.3x10(-6) for Ottawa, Hamilton and Toronto respectively. The cancer risks exceedance probabilities were estimated to be highest in Ottawa at different risk levels. The risks through inhalation exposure were found to be comparable (2.1x10(-6)-3.7x10(-6)) to those of the dermal contact (2.2x10(-6)-3.9x10(-6)) for the cities. This study predicted 36 cancer incidents from exposure to THMs during showering for these three cities, while Toronto contributed the highest number of possible cancer incidents (22), followed by Ottawa (10) and Hamilton (4). The sensitivity analyses showed that health risks could be controlled by varying shower stall volume and/or shower duration following the power law relationship.

  15. Luminous Efficiency of Hypervelocity Meteoroid Impacts on the Moon Derived from the 2015 Geminid Meteor Shower

    Science.gov (United States)

    Moser, D. E.; Suggs, R. M.; Ehlert, S. R.

    2017-01-01

    Meteoroids cannot be observed directly because of their small size. In-situ measurements of the meteoroid environment are rare and have very small collecting areas. The Moon, in contrast, has a large collecting area and therefore can be used as a large meteoroid detector for gram-kilogram sized particles. Meteoroids striking the Moon create an impact flash observable by Earth-based telescopes. Their kinetic energy is converted to luminous energy with some unknown luminous efficiency ?(v), which is likely a function of meteoroid velocity (among other factors). This luminous efficiency is imperative to calculating the kinetic energy and mass of the meteoroid, as well as meteoroid fluxes, and it cannot be determined in the laboratory at meteoroid speeds and sizes due to mechanical constraints. Since laboratory simulations fail to resolve the luminous efficiency problem, observations of the impact flash itself must be utilized. Meteoroids associated with specific meteor showers have known speed and direction, which simplifies the determination of the luminous efficiency. NASA has routinely monitored the Moon for impact flashes since early 2006 [1]. During this time, several meteor showers have produced multiple impact flashes on the Moon, yielding a sufficient sample of impact flashes with which to perform a luminous efficiency analysis similar to that outlined in Bellot Rubio et al. [2, 3] and further described by Moser et al. [4], utilizing Earth-based measurements of the shower flux and mass index. The Geminid meteor shower has produced the most impact flashes in the NASA dataset to date with over 80 detections. More than half of these Geminids were recorded in 2015 (locations pictured in Fig. 1), and may represent the largest single-shower impact flash sample known. This work analyzes the 2015 Geminid lunar impacts and calculates their luminous efficiency. The luminous efficiency is then applied to calculate the kinetic energies and mass-es of these shower

  16. Shower PUVA: a novel variant of photochemotherapy. Distribution of photosensitivity and accumulation of trioxsalen in the skin.

    Science.gov (United States)

    Sánchez Ruderisch, H; Aryee-Boi, J; Schwarz, C; Radenhausen, M; Tebbe, B

    2004-01-01

    Shower PUVA is a new variant of photochemotherapy suitable for therapy of various skin disorders. Psoralen, e.g. trioxsalen-containing water recirculates in a closed shower system and wets the skin continuously. After showering, whole-body UVA irradiation (320-400 nm) is performed. In order to prove the equal distribution of photosensitivity in vivo minimal phototoxic dose (MPD) was determined in different skin areas of healthy individuals. Additionally, we investigated the accumulation of trioxsalen in psoriasis lesions under the conditions described by quantifying psoralen in scales collected after showering. In a randomized study 20 healthy volunteers (skin type I-III) took showers for 5 and 10 min in trioxsalen (0.27 mg/l)-containing water at 37 degrees C. Immediately afterwards, MPD was tested on the inside of the upper arms and on the buttocks by using a polychromator light source (315-400 nm). The applied UVA doses were 0.06-0.75 J/cm(2) with steps of 0.125 J/cm(2). MPD was evaluated after 72 h. Equal distribution of photosensitivity was defined as equal MPD on the insides of the upper arm and the buttocks (+/-0.125 J/cm(2)). Skin scales of 21 patients with psoriasis were collected by scratching after showering with trioxsalen-containing water (0.27 mg/l) for 5 min. For quantification of trioxsalen in the scales HPLC was performed. An equal distribution of photosensitivity was achieved in 70% (14/20) cases after 10-min showering in trioxsalen-containing water. Showering for 5 min only revealed a 30% (6/20) rate of equal distributed photosensitivity. After 10-min shower time MPD was 0.325 J/cm(2) (median; range: 0.06-0.625 J/cm(2)). The average amount of trioxsalen found in the scales was 2.03 ng/mg scales (range: 0.38-7.2 ng/mg). For shower PUVA using trioxsalen, 10 min shower time is recommended to achieve sufficient distribution of photosensitivity on the skin. Clinical efficacy of shower PUVA can be explained by skin accumulation of trioxsalen which

  17. Tuning of the Shower Library for the LHCb calorimeter fast simulation

    CERN Document Server

    Rabemananjara, Tanjona Radonirina

    2016-01-01

    The standard simulation of the LHCb detector uses the Geant4 simulation toolkit, which provides very accurate results but is CPU-expensive. A number of faster simulation options are available or under development. Among the latter, the replacement of the electromagnetic and hadronic showers simulation in the calorimeter with pre-simulated hit libraries is ongoing. My work has focused on the characterization of the particles reaching the calorimeter in simulated minimum bias events and on the study of how the cell hit distributions change as a function of some particle parameters. The results will contribute to understanding how to optimize the information stored in the shower library under development.

  18. Cherenkov Radiation from e+e- Pairs and Its Effect on nu e InducedShowers

    Energy Technology Data Exchange (ETDEWEB)

    Mandal, Sourav K.; Klein, Spencer R.; Jackson, J. David

    2005-06-08

    We calculate the Cherenkov radiation from an e{sup +}e{sup -} pair at small separations, as occurs shortly after a pair conversion. The radiation is reduced (compared to that from two independent particles) when the pair separation is smaller than the wavelength of the emitted light. We estimate the reduction in light in large electromagnetic showers, and discuss the implications for detectors that observe Cherenkov radiation from showers in the Earth's atmosphere, as well as in oceans and Antarctic ice.

  19. Measuring the muon content of air showers with IceTop

    Directory of Open Access Journals (Sweden)

    Gonzalez Javier G.

    2015-01-01

    Full Text Available IceTop, the surface component of the IceCube detector, has been used to measure the energy spectrum of cosmic ray primaries in the range between 1.58 PeV and 1.26 EeV. It can also be used to study the low energy muons in air showers by looking at large distances (> 300 m from the shower axis. We will show the muon lateral distribution function at large lateral distances as measured with IceTop and discuss the implications of this measurement. We will also discuss the prospects for low energy muon studies with IceTop.

  20. MRSA in pork production shower facilities: an intervention to reduce occupational exposure.

    Science.gov (United States)

    Leedom Larson, K R; Wagstrom, E A; Donham, K J; Harper, A L; Hanson, B M; Male, M J; Smith, T C

    2012-01-01

    Methicillin-resistant Staphylococcus aureus (MRSA) nasal colonization has been documented in swine and swine workers. MRSA has also been found in the shower facilities of conventional swine farms. We previously conducted a review of the literature to identify measures used to reduce MRSA prevalence in athletic facilities. In this study, we evaluated those measures for adaptability to the pork production environment. A best practices protocol was developed to reduce MRSA levels in pork production shower facilities and implemented in two conventional swine production systems.

  1. QGSJET-II: physics, recent improvements, and results for air showers

    Directory of Open Access Journals (Sweden)

    Ostapchenko S.

    2013-06-01

    Full Text Available Modeling of high energy hadronic and nuclear interactions by the QGSJET-II generator is discussed. Recent updates related to the treatment of nonlinear effects inthe interaction dynamics and to the model calibration with new LHC data are described. A special attention is devoted to the predictions of the new model version forcharacteristics of extensive air showers initiated by high energy cosmic rays. In particular, an improved description of charge exchange processes in pion collisionsis discussed and the respective enhancement of the shower muon content is analyzed.

  2. Ice surface roughness modeling for effect on radio signals from UHE particle showers

    Science.gov (United States)

    Stockham, Jessica

    2014-03-01

    For radio antenna detectors located in or above the Antarctic ice sheet, the reconstruction of both ultra-high energy (UHE) neutrino and cosmic ray air shower events requires understanding the transmission and reflection properties of the air-ice interface. To this end, surface and volume scattering from granular materials in the microwave frequency range are measured and stereoscopic images of the ice surface, obtained by the Antarctric Geophysics Along the Vostok Expedition (AGAVE), are used to determine the 3D surface structure. This data is implemented to determine an appropriate model for use in simulation and data analysis of the shower events. ANtarctic Impulsive Transient Antenna.

  3. First results on the spatiotemporal correlations of the remote Extensive Air Shower pairs

    International Nuclear Information System (INIS)

    Verbetsky, Yu; Svanidze, M; Iashvili, A; Tskhadadze, E; Kokorashvili, D

    2013-01-01

    The GELATICA experiment in Georgia (GEorgian Large-area Angle and TIme Coincidence Array) is devoted both to the Cosmic Ray (CR) energy spectrum investigation at very high energies and possible correlations in the arrival times and directions of separate Extensive Air Showers (EAS) over large distances. The timing distributions between the consecutive EAS events observed at the remote installations in the towns of Tbilisi and Telavi are considered. The expectation time for a consecutive pair of remote random EAS events at these two installations is estimated under the condition of their timing separation being less then a tolerable propagation time of shower front between the observation points.

  4. Flow excited by full jet shower in QGP fluid and its effect on jet shape

    Science.gov (United States)

    Tachibana, Yasuki; Chang, Ning-Bo; Qin, Guang-You

    2017-08-01

    We study the nuclear modification of full jet structure in relativistic heavy-ion collisions, with the inclusion of the effect of the medium response. The evolution of full jet shower is described by a set of transport equations, and the space-time evolution of quark-gluon plasma is simulated by solving relativistic hydrodynamic equations coupled with the energy and momentum depositions by jets as the source terms. We study the effect of medium response to full jet shower and present how jet-induced flow contributes to the full jet structure in PbPb collisions at the LHC.

  5. Meteor shower activity derived from meteor watching public campaign in Japan

    Science.gov (United States)

    Ishizaki, Masaharu; Watanabe, Jun-ichi; Sato, Mikiya

    2017-09-01

    We have carried out a meteor watching public campaigns from 2004 for major meteor showers in the case of appropriate observing condition as one of the outreach programs conducted by National Astronomical Observatory of Japan. We received a huge number of the reports on meteor counts from the general public participants. The results sometimes show similar time variation of the hourly rates derived from the data collected by skilled observers. In this paper, some of the results are presented showing that such campaigns have a potential to extract scientific result related to the meteor showers mainly due to the large number of the data collected by unskilled observers.

  6. The lateral distribution of muons in showers at 40 mwe underground

    International Nuclear Information System (INIS)

    Bergamasco, L.; Castagnoli, C.; Dardo, M.; D'Ettorre Piazzoli, B.; Mannocchi, G.; Picchi, P.; Visentin, R.; Sitte, K.; Freiburg Univ.

    1975-01-01

    The multiplicity distribution of muon showers at 40 mwe underground was studied with a 4 m 2 spark chamber telescope. The observed frequencies deviate systematically from those calculated with the 'standard' lateral distributions of Vernov or of Greisen. Agreement can be attained if an enhancement of the muon component at small shower sizes is assumed, in accordance with the assumptions of a two-component theory of cosmic ray origin. It is improved by introducing an age dependence of the lateral structure function. (orig.) [de

  7. A parton shower based on factorization of the quantum density matrix

    International Nuclear Information System (INIS)

    Nagy, Zoltan; Soper, Davison E.

    2014-01-01

    We present rst results from a new parton shower event generator, DEDUCTOR. Anticipating a need for an improved treatment of parton color and spin, the structure of the generator is based on the quantum density matrix in color and spin space. So far, DEDUCTOR implements only a standard spin-averaged treatment of spin in parton splittings. Although DEDUCTOR implements an improved treatment of color, in this paper we present results in the standard leading color approximation so that we can compare to the generator PYTHIA. The algorithms used incorporate a virtuality based shower ordering parameter and massive initial state bottom and charm quarks.

  8. Further development of data acquisition system of the Akeno giant air shower array

    International Nuclear Information System (INIS)

    Ohoka, H.; Hayashida, N.; Kakimoto, F.; Kamata, K.; Kawaguchi, S.; Kawasumi, N.; Nagano, M.

    1997-01-01

    The data acquisition system of the Akeno giant air shower array (AGASA) is described. The AGASA array covers an area of about 100 km 2 and has been operated since 1990 to study the origin of extremely high energy cosmic rays. In the early stage of our experiment, AGASA was divided into four sub-arrays called branches for topographical reasons so that air showers were observed independently at each branch. In December 1995, we have improved the data acquisition system and unified the four branches into a single detection system. By this unification, the effective detection area of the AGASA increases by about 1.7 times in the early stage. (orig.)

  9. The differences in delay times for air showers initiated by 100 TeV gamma rays and protons

    International Nuclear Information System (INIS)

    Mikocki, S.; Poirier, J.; Linsley, J.; Consiglio Nazionale delle Ricerche, Palermo; Wrotniak, A.; Maryland Univ., College Park

    1987-01-01

    The purpose of this study is to investigate whether there are any differences in the time delay distributions between showers initiated by gamma rays and by protons. The results of Monte Carlo calculations of atmospheric showers initiated by gamma rays and protons at an energy of 100 TeV show systematic differences. These differences are negligible at small distances from the core of the showers; at larger distances the effects become large. However, at large distances the particle densities are small at an energy of 100 TeV and the subsequent statistical fluctuations would make an identification of gamma-ray showers unreliable. However, these large effects should be included in corrections for the curvature of gamma-ray and proton shower fronts. (author)

  10. Efficacy of Warm Showers on Postpartum Fatigue Among Vaginal-Birth Taiwanese Women: A Quasi-Experimental Design.

    Science.gov (United States)

    Hsieh, Ching-Hsing; Chen, Chien-Lan; Chung, Feng-Fang; Lin, Su-Ying

    2017-05-01

    Postpartum fatigue is one of the most common complaints among women following childbirth. As a postpartum ritual practice, Taiwanese women refrain from taking showers while "doing the month." However, warm showers are the systemic application of moist heat, and they maintain physical hygiene, stimulate blood circulation, mitigate discomfort, and provide relaxation. As Taiwanese society becomes increasingly receptive to scientific and contemporary health care practice, more and more women choose to take warm showers after childbirth. The purpose of this study was to evaluate the efficacy of warm showers on postpartum fatigue among vaginal-birth women in Taiwan. This was a two-group quasi-experimental design. Women took showers in warm water with temperatures ranging between 40 °C and 43 °C for approximately 20 minutes. Postpartum women's fatigue is measured using the 10-item Postpartum Fatigue Scale (PFS). The intervention effect was analyzed using a generalized estimating equation (GEE) model. The study population consisted of 358 vaginal-birth postpartum Taiwanese women aged 20-43 years. Postpartum women who took warm showers showed improvements from their pretest to posttest mean scores of postpartum fatigue compared to postpartum women who did not take warm showers. Warm showers helped to reduce postpartum fatigue among vaginal-birth women during the study period. Nurses have the unique opportunity to provide the intervention to Taiwanese women who have vaginal birth to help them relieve postpartum fatigue with warm showers while "doing the month" without the taboo of no-showering customary practices in the early postpartum period.

  11. Defect production in simulated cascades: cascade quenching and short-term annealing

    International Nuclear Information System (INIS)

    Heinisch, H.L.

    1982-01-01

    Defect production in high energy displacement cascades has been modeled using the computer code MARLOWE to generate the cascades and the stochastic computer code ALSOME to simulate the cascade quenching and short-term annealing of isolated cascades. The quenching is accomplished by using ALSOME with exaggerated values for defect mobilities and critical reaction distanes for recombination and clustering, which are in effect until the number of defect pairs is equal to the value determined from resistivity experiments at 4K. Then normal mobilities and reaction distances are used during short-term annealing to a point representative of Stage III recovery. Effects of cascade interactions at low fluences are also being investigated. The quenching parameter values were empirically determined for 30 keV cascades. The results agree well with experimental information throughout the range from 1 keV to 100 keV. Even after quenching and short-term annealing the high energy cascades behave as a collection of lower energy subcascades and lobes. Cascades generated in a crystal having thermal displacements were found to be in better agreement with experiments after quenching and annealing than those generated in a non-thermal crystal

  12. Reconstruction of 10(exp 20)ev Showers in EUSO and JEM EUSO

    Science.gov (United States)

    Andreev, V.; Adams, J.; Cline, D.

    2007-01-01

    We describe the procedure to reconstruct 10(exp 20) ev showers in Extreme Universe Space Observatory (EUSO). We show the angular and energy resolution is excellent. We now apply this to the newly proposed Japanese JEM-EUSO and will present results at the meeting.

  13. Reconstruction of extensive air showers using the MIDAS molecular Bremsstrahlung detector

    Energy Technology Data Exchange (ETDEWEB)

    Castro, Andre Ramos de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola Politecnica; Bonifazi, Carla; Santos, Edivaldo Moura; Soares, Elvis do Amaral; Mello Neto, Joao Ramos Torres de [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Fisica; Almeida, Rogerio Menezes de [Universidade Federal Fluminense (EEIMVR/UFF), Volta Redonda, RJ (Brazil). Escola de Engenharia Industrial Metalurgica de Volta Redonda

    2011-07-01

    Full text: The weakly ionized plasma created in the atmosphere after the passage of an Extensive Air Shower (EAS) gives rise to the emission of continuous radiation known as Molecular Bremsstrahlung Radiation (MBR) as free electrons scatter off neutral nitrogen (and less frequently oxygen) molecules. The isotropic and unpolarized nature of MBR rises the possibility of an EAS detection similar to that using fluorescence telescopes to capture the ultraviolet light emitted by the ionized nitrogen molecules. The MBR emission, however, falls into the centimeter wavelength range, requiring the use of radio/microwave antennas instead of optical telescopes. In order to test the feasibility of the technique, the MIDAS (Microwave Detection of Air Showers) Collaboration has built a prototype detector where a parabolical reflector illuminates a multi-pixel camera of commercial TV satellite C-band (3.4-4.2 GHz) feeds. This work addresses the geometrical reconstruction of EAS induced by Ultra High Energy Cosmic Rays (UHECR) using the MIDAS detector. The reconstruction chain is similar to that currently applied to the Auger Fluorescence detector events. We have simulated the shower MBR emission assuming two different scenarios: coherent and incoherent emission, i.e., radiation intensity scaling quadratically and linearly with the energy of the primary particle. The MIDAS prototype detector's response is then simulated. Finally, given the simulated events in real data format, we reconstruct the shower's arrival direction, including direction uncertainties and estimate the expected rate of observed events. (author)

  14. The time structure of hadronic showers in highly granular calorimeters with tungsten and steel absorbers

    Czech Academy of Sciences Publication Activity Database

    Adloff, C.; Blaising, J.J.; Chefdeville, M.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav

    2014-01-01

    Roč. 9, Jul (2014), s. 1-24 ISSN 1748-0221 R&D Projects: GA MŠk LG14033 Institutional support: RVO:68378271 Keywords : hadronic calorimeter s * hadronic showers * hadronic physics models * hilicon photomultiplier Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.399, year: 2014

  15. Rapidly growing nontuberculous mycobacteria cultured from home tap and shower water.

    Science.gov (United States)

    van Ingen, Jakko; Blaak, Hetty; de Beer, Jessica; de Roda Husman, Ana Maria; van Soolingen, Dick

    2010-09-01

    Tap and shower water at two locations in the Netherlands was examined for the presence of rapidly growing nontuberculous mycobacteria. Cultures yielded Mycobacterium peregrinum, M. salmoniphilum, M. llatzerense, M. septicum, and three potentially novel species, a distribution different from that in clinical samples.

  16. The presence and growth of Legionella species in thermostatic shower mixer taps: an exploratory field study

    NARCIS (Netherlands)

    Joost van Hoof; P.W.J.J. van der Wielen; E. van der Blom; O.W.W. Nuijten; L. Hornstra

    2014-01-01

    Legislation in the Netherlands requires routine analysis of drinking water samples for cultivable Legionella species from high-priority installations. A field study was conducted to investigate the presence of Legionella species in thermostatic shower mixer taps. Water samples and the interior of

  17. Optical observations of enhanced activity of the 2005 Draconid meteor shower

    Czech Academy of Sciences Publication Activity Database

    Koten, Pavel; Borovička, Jiří; Spurný, Pavel; Štork, Rostislav

    2007-01-01

    Roč. 466, č. 2 (2007), s. 729-735 ISSN 0004-6361 R&D Projects: GA AV ČR KJB300030502; GA ČR GA205/05/0543 Institutional research plan: CEZ:AV0Z10030501 Keywords : meteors * meteor shower s * Draconids Subject RIV: BN - Astronomy, Celestial Mechanics, Astrophysics Impact factor: 4.259, year: 2007

  18. The air shower maximum probed by Cherenkov effects from radio emission

    NARCIS (Netherlands)

    de Vries, Krijn D.; Scholten, Olaf; Werner, Klaus

    Radio detection of cosmic-ray-induced air showers has come to a flight the last decade. Along with the experimental efforts, several theoretical models were developed. The main radio-emission mechanisms are established to be the geomagnetic emission due to deflection of electrons and positrons in

  19. A shower before bedtime may improve the sleep onset latency of youth soccer players.

    Science.gov (United States)

    Whitworth-Turner, Craig; Di Michele, Rocco; Muir, Ian; Gregson, Warren; Drust, Barry

    2017-10-01

    During the competitive season, soccer players are likely exposed to numerous factors that may disrupt the process of sleep. The current investigation looked to evaluate a practical sleep hygiene strategy (10-min showering at ∼40°C before lights out), within a group of 11 youth soccer players in comparison to normal sleeping conditions (control). Each condition consisted of three days within a randomised crossover trial design. Sleep information was collected using a commercial wireless bedside sleep monitor. Measures of skin temperature were evaluated using iButton skin thermistors to establish both distal and proximal skin temperatures and distal to proximal gradient. The shower intervention elevated distal skin temperature by 1.1°C (95% CI: 0.1-2.1°C, p = .04) on average prior to lights out. The elevation in distal temperature was also present during the first 30-min following lights out (1.0°C, 95% CI: 0.4-1.6°C, p shower condition. These findings demonstrate that a warm shower performed before lights out may offer a practical strategy to promote thermoregulatory changes that may advance sleep onset latency and improve sleep efficiency in athletes.

  20. [Diagnosis of cannabinoid hyperemesis : update on the cannabis-shower syndrome].

    Science.gov (United States)

    Cuppens, B; Gensburger, M; Tonglet, M; Marissiaux, L; Brasseur, E; d'Orio, V; Ghuysen, A

    2016-12-01

    Sometimes, the emergency department is confronted with cases of repetitive vomiting and abdominal pain without organic causes. These patients come back again and again for this problem. All diagnostic tests are systematically negative. A well conducted history taking reveals a chronic cannabis addiction and the disappearance of symptomatology by taking hot showers. This presentation is pathognomonic of the cannabinoid hyperemesis syndrome.

  1. EVALUATION OF STYRENE EMISSIONS FROM A SHOWER STALL/BATHTUB MANUFACTURING FACILITY

    Science.gov (United States)

    The report gives results of emissions measurements carried out at a representative facility (Eljer Plumbingware in Wilson, NC) that manufactures polyester-resin-reinforced shower stalls and bathtubs by spraying styrene-based resins onto molds in vented, open, spray booths. Styren...

  2. Reconstruction of extensive air showers using the MIDAS molecular Bremsstrahlung detector

    International Nuclear Information System (INIS)

    Castro, Andre Ramos de; Bonifazi, Carla; Santos, Edivaldo Moura; Soares, Elvis do Amaral; Mello Neto, Joao Ramos Torres de; Almeida, Rogerio Menezes de

    2011-01-01

    Full text: The weakly ionized plasma created in the atmosphere after the passage of an Extensive Air Shower (EAS) gives rise to the emission of continuous radiation known as Molecular Bremsstrahlung Radiation (MBR) as free electrons scatter off neutral nitrogen (and less frequently oxygen) molecules. The isotropic and unpolarized nature of MBR rises the possibility of an EAS detection similar to that using fluorescence telescopes to capture the ultraviolet light emitted by the ionized nitrogen molecules. The MBR emission, however, falls into the centimeter wavelength range, requiring the use of radio/microwave antennas instead of optical telescopes. In order to test the feasibility of the technique, the MIDAS (Microwave Detection of Air Showers) Collaboration has built a prototype detector where a parabolical reflector illuminates a multi-pixel camera of commercial TV satellite C-band (3.4-4.2 GHz) feeds. This work addresses the geometrical reconstruction of EAS induced by Ultra High Energy Cosmic Rays (UHECR) using the MIDAS detector. The reconstruction chain is similar to that currently applied to the Auger Fluorescence detector events. We have simulated the shower MBR emission assuming two different scenarios: coherent and incoherent emission, i.e., radiation intensity scaling quadratically and linearly with the energy of the primary particle. The MIDAS prototype detector's response is then simulated. Finally, given the simulated events in real data format, we reconstruct the shower's arrival direction, including direction uncertainties and estimate the expected rate of observed events. (author)

  3. Muons in air showers at the Pierre Auger Observatory: Mean number in highly inclined events

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muñiz, J.; Alves Batista, R.; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Badescu, A. M.; Barber, K. B.; Bäuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertaina, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blanco, M.; Bleve, C.; Blümer, H.; Boháčová, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceição, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Díaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Dorosti Hasankiadeh, Q.; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Facal San Luis, P.; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipčič, A.; Fox, B. D.; Fratu, O.; Fröhlich, U.; Fuchs, B.; Fujii, T.; Gaior, R.; García, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gómez Berisso, M.; Gómez Vitale, P. F.; Gonçalves, P.; Gonzalez, J. G.; González, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guardincerri, Y.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hörandel, J. R.; Horvath, P.; Hrabovský, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Islo, K.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kääpä, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kégl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Krömer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leão, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; López, R.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Mariş, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martínez Bravo, O.; Martraire, D.; Masías Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J. J.; Matthews, A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Mićanović, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Monnier Ragaigne, D.; Montanet, F.; Morello, C.; Mostafá, M.; Moura, C. A.; Muller, M. A.; Müller, G.; Münchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Newton, D.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nožka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Olmos-Gilbaja, V. M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Roberts, J.; Rodrigues de Carvalho, W.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodríguez-Frías, M. D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Salesa Greus, F.; Salina, G.; Sánchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Scholten, O.; Schoorlemmer, H.; Schovánek, P.; Schröder, F. G.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Śmiałkowski, A.; Šmída, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanič, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijärvi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tomé, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Ulrich, R.; Unger, M.; Urban, M.; Valdés Galicia, J. F.; Valiño, I.; Valore, L.; van Aar, G.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cárdenas, B.; Varner, G.; Vázquez, J. R.; Vázquez, R. A.; Veberič, D.; Verzi, V.; Vicha, J.; Videla, M.; Villaseñor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczyńska, B.; Wilczyński, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Younk, P.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.; Pierre Auger Collaboration, [No Value

    2015-01-01

    We present the first hybrid measurement of the average muon number in air showers at ultrahigh energies, initiated by cosmic rays with zenith angles between 62° and 80°. The measurement is based on 174 hybrid events recorded simultaneously with the surface detector array and the fluorescence

  4. Depth of maximum of air-shower profiles at the Pierre Auger Observatory. II. Composition implications

    NARCIS (Netherlands)

    Aab, A.; Abreu, P.; Aglietta, M.; Ahn, E. J.; Al Samarai, I.; Albuquerque, I. F. M.; Allekotte, I.; Allen, J.; Allison, P.; Almela, A.; Alvarez Castillo, J.; Alvarez-Muniz, J.; Batista, R. Alves; Ambrosio, M.; Aminaei, A.; Anchordoqui, L.; Andringa, S.; Aramo, C.; Aranda, V. M.; Arqueros, F.; Asorey, H.; Assis, P.; Aublin, J.; Ave, M.; Avenier, M.; Avila, G.; Awal, N.; Badescu, A. M.; Barber, K. B.; Baeuml, J.; Baus, C.; Beatty, J. J.; Becker, K. H.; Bellido, J. A.; Berat, C.; Bertania, M. E.; Bertou, X.; Biermann, P. L.; Billoir, P.; Blaess, S.; Blanco, M.; Bleve, C.; Bluemer, H.; Bohacova, M.; Boncioli, D.; Bonifazi, C.; Bonino, R.; Borodai, N.; Brack, J.; Brancus, I.; Bridgeman, A.; Brogueira, P.; Brown, W. C.; Buchholz, P.; Bueno, A.; Buitink, S.; Buscemi, M.; Caballero-Mora, K. S.; Caccianiga, B.; Caccianiga, L.; Candusso, M.; Caramete, L.; Caruso, R.; Castellina, A.; Cataldi, G.; Cazon, L.; Cester, R.; Chavez, A. G.; Chiavassa, A.; Chinellato, J. A.; Chudoba, J.; Cilmo, M.; Clay, R. W.; Cocciolo, G.; Colalillo, R.; Coleman, A.; Collica, L.; Coluccia, M. R.; Conceicao, R.; Contreras, F.; Cooper, M. J.; Cordier, A.; Coutu, S.; Covault, C. E.; Cronin, J.; Curutiu, A.; Dallier, R.; Daniel, B.; Dasso, S.; Daumiller, K.; Dawson, B. R.; de Almeida, R. M.; De Domenico, M.; de Jong, S. J.; de Mello Neto, J. R. T.; De Mitri, I.; de Oliveira, J.; de Souza, V.; del Peral, L.; Deligny, O.; Dembinski, H.; Dhital, N.; Di Giulio, C.; Di Matteo, A.; Diaz, J. C.; Diaz Castro, M. L.; Diogo, F.; Dobrigkeit, C.; Docters, W.; D'Olivo, J. C.; Dorofeev, A.; Hasankiadeh, Q. Dorosti; Dova, M. T.; Ebr, J.; Engel, R.; Erdmann, M.; Erfani, M.; Escobar, C. O.; Espadanal, J.; Etchegoyen, A.; Luis, P. Facal San; Falcke, H.; Fang, K.; Farrar, G.; Fauth, A. C.; Fazzini, N.; Ferguson, A. P.; Fernandes, M.; Fick, B.; Figueira, J. M.; Filevich, A.; Filipcic, A.; Fox, B. D.; Fratu, O.; Froehlich, U.; Fuchs, B.; Fuji, T.; Gaior, R.; Garcia, B.; Garcia Roca, S. T.; Garcia-Gamez, D.; Garcia-Pinto, D.; Garilli, G.; Gascon Bravo, A.; Gate, F.; Gemmeke, H.; Ghia, P. L.; Giaccari, U.; Giammarchi, M.; Giller, M.; Glaser, C.; Glass, H.; Gomez Berisso, M.; Gomez Vitale, P. F.; Goncalves, P.; Gonzalez, J. G.; Gonzalez, N.; Gookin, B.; Gordon, J.; Gorgi, A.; Gorham, P.; Gouffon, P.; Grebe, S.; Griffith, N.; Grillo, A. F.; Grubb, T. D.; Guarino, F.; Guedes, G. P.; Hampel, M. R.; Hansen, P.; Harari, D.; Harrison, T. A.; Hartmann, S.; Harton, J. L.; Haungs, A.; Hebbeker, T.; Heck, D.; Heimann, P.; Herve, A. E.; Hill, G. C.; Hojvat, C.; Hollon, N.; Holt, E.; Homola, P.; Hoerandel, J. R.; Horvath, P.; Hrabovsky, M.; Huber, D.; Huege, T.; Insolia, A.; Isar, P. G.; Jandt, I.; Jansen, S.; Jarne, C.; Josebachuili, M.; Kaeaepae, A.; Kambeitz, O.; Kampert, K. H.; Kasper, P.; Katkov, I.; Kegl, B.; Keilhauer, B.; Keivani, A.; Kemp, E.; Kieckhafer, R. M.; Klages, H. O.; Kleifges, M.; Kleinfeller, J.; Krause, R.; Krohm, N.; Kroemer, O.; Kruppke-Hansen, D.; Kuempel, D.; Kunka, N.; LaHurd, D.; Latronico, L.; Lauer, R.; Lauscher, M.; Lautridou, P.; Le Coz, S.; Leao, M. S. A. B.; Lebrun, D.; Lebrun, P.; Leigui de Oliveira, M. A.; Letessier-Selvon, A.; Lhenry-Yvon, I.; Link, K.; Lopez, R.; Lopez Agueera, A.; Louedec, K.; Lozano Bahilo, J.; Lu, L.; Lucero, A.; Ludwig, M.; Malacari, M.; Maldera, S.; Mallamaci, M.; Maller, J.; Mandat, D.; Mantsch, P.; Mariazzi, A. G.; Marin, V.; Maris, I. C.; Marsella, G.; Martello, D.; Martin, L.; Martinez, H.; Martinez Bravo, O.; Martraire, D.; Masias Meza, J. J.; Mathes, H. J.; Mathys, S.; Matthews, J.; Matthews, J. A. J.; Matthiae, G.; Maurel, D.; Maurizio, D.; Mayotte, E.; Mazur, P. O.; Medina, C.; Medina-Tanco, G.; Meissner, R.; Melissas, M.; Melo, D.; Menshikov, A.; Messina, S.; Meyhandan, R.; Micanovic, S.; Micheletti, M. I.; Middendorf, L.; Minaya, I. A.; Miramonti, L.; Mitrica, B.; Molina-Bueno, L.; Mollerach, S.; Monasor, M.; Ragaigne, D. Monnier; Montanet, F.; Morello, C.; Mostafa, M.; Moura, C. A.; Muller, M. A.; Mueller, G.; Mueller, S.; Muenchmeyer, M.; Mussa, R.; Navarra, G.; Navas, S.; Necesal, P.; Nellen, L.; Nelles, A.; Neuser, J.; Nguyen, P.; Niechciol, M.; Niemietz, L.; Niggemann, T.; Nitz, D.; Nosek, D.; Novotny, V.; Nozka, L.; Ochilo, L.; Olinto, A.; Oliveira, M.; Pacheco, N.; Pakk Selmi-Dei, D.; Palatka, M.; Pallotta, J.; Palmieri, N.; Papenbreer, P.; Parente, G.; Parra, A.; Paul, T.; Pech, M.; Pekala, J.; Pelayo, R.; Pepe, I. M.; Perrone, L.; Petermann, E.; Peters, C.; Petrera, S.; Petrov, Y.; Phuntsok, J.; Piegaia, R.; Pierog, T.; Pieroni, P.; Pimenta, M.; Pirronello, V.; Platino, M.; Plum, M.; Porcelli, A.; Porowski, C.; Prado, R. R.; Privitera, P.; Prouza, M.; Purrello, V.; Quel, E. J.; Querchfeld, S.; Quinn, S.; Rautenberg, J.; Ravel, O.; Ravignani, D.; Revenu, B.; Ridky, J.; Riggi, S.; Risse, M.; Ristori, P.; Rizi, V.; Rodrigues de Carvalho, W.; Rodriguez Cabo, I.; Rodriguez Fernandez, G.; Rodriguez Rojo, J.; Rodriguez-Frias, M. D.; Rogozin, D.; Ros, G.; Rosado, J.; Rossler, T.; Roth, M.; Roulet, E.; Rovero, A. C.; Saffi, S. J.; Saftoiu, A.; Salamida, F.; Salazar, H.; Saleh, A.; Greus, F. Salesa; Salina, G.; Sanchez, F.; Sanchez-Lucas, P.; Santo, C. E.; Santos, E.; Santos, E. M.; Sarazin, F.; Sarkar, B.; Sarmento, R.; Sato, R.; Scharf, N.; Scherini, V.; Schieler, H.; Schiffer, P.; Schmidt, D.; Scholten, O.; Schoorlemmer, H.; Schovanek, P.; Schulz, A.; Schulz, J.; Schumacher, J.; Sciutto, S. J.; Segreto, A.; Settimo, M.; Shadkam, A.; Shellard, R. C.; Sidelnik, I.; Sigl, G.; Sima, O.; Smialkowski, A.; Smida, R.; Snow, G. R.; Sommers, P.; Sorokin, J.; Squartini, R.; Srivastava, Y. N.; Stanic, S.; Stapleton, J.; Stasielak, J.; Stephan, M.; Stutz, A.; Suarez, F.; Suomijaervi, T.; Supanitsky, A. D.; Sutherland, M. S.; Swain, J.; Szadkowski, Z.; Szuba, M.; Taborda, O. A.; Tapia, A.; Tartare, M.; Tepe, A.; Theodoro, V. M.; Timmermans, C.; Todero Peixoto, C. J.; Toma, G.; Tomankova, L.; Tome, B.; Tonachini, A.; Torralba Elipe, G.; Torres Machado, D.; Travnicek, P.; Trovato, E.; Tueros, M.; Ulrich, R.; Unger, M.; Urban, M.; Valdes Galicia, J. F.; Valino, I.; Valore, L.; van Aar, G.; van Bodegom, P.; van den Berg, A. M.; van Velzen, S.; van Vliet, A.; Varela, E.; Vargas Cardenas, B.; Varner, G.; Vazquez, J. R.; Vazquez, R. A.; Veberic, D.; Verzi, V.; Vicha, J.; Videla, M.; Villasenor, L.; Vlcek, B.; Vorobiov, S.; Wahlberg, H.; Wainberg, O.; Walz, D.; Watson, A. A.; Weber, M.; Weidenhaupt, K.; Weindl, A.; Werner, F.; Widom, A.; Wiencke, L.; Wilczynska, B.; Wilczynski, H.; Will, M.; Williams, C.; Winchen, T.; Wittkowski, D.; Wundheiler, B.; Wykes, S.; Yamamoto, T.; Yapici, T.; Yuan, G.; Yushkov, A.; Zamorano, B.; Zas, E.; Zavrtanik, D.; Zavrtanik, M.; Zaw, I.; Zepeda, A.; Zhou, J.; Zhu, Y.; Zimbres Silva, M.; Ziolkowski, M.; Zuccarello, F.

    2014-01-01

    Using the data taken at the Pierre Auger Observatory between December 2004 and December 2012, we have examined the implications of the distributions of depths of atmospheric shower maximum (X-max), using a hybrid technique, for composition and hadronic interaction models. We do this by fitting the

  5. The Hisparc cosmic ray experiment : data acquisition and reconstruction of shower direction

    NARCIS (Netherlands)

    Fokkema, D.; Fokkema, D.

    2012-01-01

    The field of cosmic ray physics is a century old and an exciting area of research. When cosmic ray particles enter our atmosphere they collide with air molecules creating new high-energy particles. These particles participate in further collisions and the entire process is known as an air shower.

  6. Longitudinal development of muons in large air showers observed at 5200 m above sea level

    International Nuclear Information System (INIS)

    Kakimoto, F.; Kaneko, T.; Mizumoto, Y.

    1983-01-01

    The longitudinal development of muons at atmospheric depths between 200 and 700 g cm - 2 has been studied by measuring the arrival time distributions of muons in air showers with primary energies from 1 x 10 17 to a few times 10 19 eV observed at Mount Chacaltaya. These arrival time distributions are consistent with those expected from very high multiplicity models of nuclear interactions, whether produced by primary protons or heavy nuclei. The longitudinal development of muons at atmospheric depths between 550 and 990 g cm - 2 determined from equi-intensity cuts of muon size spectra of air showers with primary energies of 1 x 10 17 eV observed at Chacaltaya is also consistent with the predictions of these same models. However, the longitudinal developments of electrons expected from such models show much faster attenuation than is observed at atmospheric depths between 550 and 1100 g cm - 2 when determined from equi-intensity cuts of electron size spectra of air showers with primary energies above 10 17 eV observed at Chacaltaya. A two-component model of air showers is proposed to explain this apparent discrepancy. (author)

  7. Polarized radio emission and radio wavefront shape of extensive air showers

    NARCIS (Netherlands)

    Corstanje, A.; Buitink, S.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Nelles, A.; Rachen, J. P.; Rossetto, L.; Schellart, P.; Scholten, O.; Ter Veen, S.; Thoudam, S.; Trinh, T. N G

    2015-01-01

    The LOFAR radio telescope located in the north of the Netherlands offers a high density of omnidirectional radio antennas. The LOFAR key science project Cosmic Rays is therefore well suited for detailed studies of the radio signal from air showers, and has been measuring since mid-2011 at primary

  8. The shape of the radio wavefront of extensive air showers as measured with LOFAR

    NARCIS (Netherlands)

    Corstanje, A.; Schellart, P.; Nelles, A.; Buitink, S.; Enriquez, J. E.; Falcke, H.; Frieswijk, W.; Hörandel, J. R.; Krause, M.; Rachen, J. P.; Scholten, O.; ter Veen, S.; Thoudam, S.; Trinh, T.N.G.; van den Akker, M.; Alexov, A.; Anderson, J.; Avruch, I. M.; Bell, M. E.; Bentum, M. J.; Bernardi, G.; Best, P.; Bonafede, A.; Breitling, F.; Broderick, J.; Brüggen, M.; Butcher, H. R.; Ciardi, B.; de Gasperin, F.; de Geus, E.; de Vos, M.; Duscha, S.; Eislöffel, J.; Engels, D.; Fallows, R. A.; Ferrari, C.; Garrett, M. A.; Grießmeier, J.; Gunst, A. W.; Hamaker, J. P.; Hoeft, M.; Horneffer, A.; Iacobelli, M.; Juette, E.; Karastergiou, A.; Kohler, J.; Kondratiev, V. I.; Kuniyoshi, M.; Kuper, G.; Maat, P.; Mann, G.; McFadden, R.; McKay-Bukowski, D.; Mevius, M.; Munk, H.; Norden, M. J.; Orru, E.; Paas, H.; Pandey-Pommier, M.; Pandey, V. N.; Pizzo, R.; Polatidis, A. G.; Reich, W.; Röttgering, H.; Scaife, A. M. M.; Schwarz, D.; Smirnov, O.; Stewart, A.; Steinmetz, M.; Swinbank, J.; Tagger, M.; Tang, Y.; Tasse, C.; Toribio, C.; Vermeulen, R.; Vocks, C.; van Weeren, R. J.; Wijnholds, S. J.; Wucknitz, O.; Yatawatta, S.; Zarka, P.

    Extensive air showers, induced by high energy cosmic rays impinging on the Earth's atmosphere, produce radio emission that is measured with the LOFAR radio telescope. As the emission comes from a finite distance of a few kilometers, the incident wavefront is non-planar. A spherical or conical shape

  9. The shape of the radio wavefront of extensive air showers as measured with LOFAR

    NARCIS (Netherlands)

    Corstanje, A.; et al., [Unknown; Swinbank, J.

    2015-01-01

    Extensive air showers, induced by high energy cosmic rays impinging on the Earth’s atmosphere, produce radio emission that is measured with the LOFAR radio telescope. As the emission comes from a finite distance of a few kilometers, the incident wavefront is non-planar. A spherical, conical or

  10. Circular polarization of radio emission from air showers in thunderstorm conditions

    NARCIS (Netherlands)

    Trinh, T. N. G.; Scholten, O.; Bonardi, A.; Buitink, S.; Corstanje, A.; Ebert, U.; Enriquez, J. E.; Falcke, H.; Hörandel, J. R.; Mitra, P.; Mulrey, K.; Nelles, A.; Thoudam, S.; Rachen, J. P.; Rossetto, L.; Rutjes, C.; Schellart, P.; ter Veen, S.; Winchen, T.

    2017-01-01

    We present measured radio emission from cosmic-ray-induced air showers under thunderstorm conditions. We observe for these events large differences in intensity, linear polarization and circular polarization from the events measured under fair-weather conditions. This can be explained by the effects

  11. Analytic Calculation of Radio Emission from Extensive Air Showers subjected to Atmospheric Electric Fields

    NARCIS (Netherlands)

    Scholten, Olaf; Trinh, Gia; de Vries, Krijn D.; van Sloten, Lucas

    2017-01-01

    We have developed a code that semi-analytically calculates the radio footprint (intensity and polarization) of an extensive air shower subject to atmospheric electric fields. This can be used to reconstruct the height dependence of atmospheric electric field from the measured radio footprint. The

  12. Influence of atmospheric electric fields on the radio emission from extensive air showers

    DEFF Research Database (Denmark)

    Trinh, T. N. G.; Scholten, O.; Buitink, S.

    2016-01-01

    The atmospheric electric fields in thunderclouds have been shown to significantly modify the intensity and polarization patterns of the radio footprint of cosmic-ray-induced extensive air showers. Simulations indicated a very nonlinear dependence of the signal strength in the frequency window of ...

  13. A general framework for implementing NLO calculations in shower Monte Carlo programs. The POWHEG BOX

    Energy Technology Data Exchange (ETDEWEB)

    Alioli, Simone [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Nason, Paolo [INFN, Milano-Bicocca (Italy); Oleari, Carlo [INFN, Milano-Bicocca (Italy); Milano-Bicocca Univ. (Italy); Re, Emanuele [Durham Univ. (United Kingdom). Inst. for Particle Physics Phenomenology

    2010-02-15

    In this work we illustrate the POWHEG BOX, a general computer code framework for implementing NLO calculations in shower Monte Carlo programs according to the POWHEG method. Aim of this work is to provide an illustration of the needed theoretical ingredients, a view of how the code is organized and a description of what a user should provide in order to use it. (orig.)

  14. A general framework for implementing NLO calculations in shower Monte Carlo programs. The POWHEG BOX

    International Nuclear Information System (INIS)

    Alioli, Simone; Nason, Paolo; Oleari, Carlo; Re, Emanuele

    2010-02-01

    In this work we illustrate the POWHEG BOX, a general computer code framework for implementing NLO calculations in shower Monte Carlo programs according to the POWHEG method. Aim of this work is to provide an illustration of the needed theoretical ingredients, a view of how the code is organized and a description of what a user should provide in order to use it. (orig.)

  15. Effects of massive photons from the dark sector on the muon content in extensive air showers

    Czech Academy of Sciences Publication Activity Database

    Ebr, Jan; Nečesal, Petr

    2013-01-01

    Roč. 725, 4-5 (2013), s. 185-189 ISSN 0370-2693 R&D Projects: GA MŠk(CZ) LA08016 Institutional support: RVO:68378271 Keywords : dark matter * bremsstrahlung * extensive air shower * muon production Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 6.019, year: 2013

  16. Detection of ultra-high energy cosmic ray showers with a single-pixel fluorescence telescope

    Czech Academy of Sciences Publication Activity Database

    Fujii, T.; Malacari, M.; Bertaina, M.; Casolino, E.; Dawson, B.; Horváth, P.; Hrabovský, M.; Jiang, J.; Mandát, Dušan; Matalon, A.; Matthews, J.N.; Motloch, P.; Palatka, Miroslav; Pech, Miroslav; Privitera, P.; Schovánek, Petr; Takizawa, Y.; Thomas, S.B.; Trávníček, Petr; Yamazaki, K.

    2016-01-01

    Roč. 74, Feb (2016), s. 64-72 ISSN 0927-6505 R&D Projects: GA MŠk(CZ) LG13007 Institutional support: RVO:68378271 Keywords : ultra-high energy cosmic rays * fluorescence detector * extensive air shower Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 3.257, year: 2016

  17. Long-Term Continuous Double Station Observation of Faint Meteor Showers

    Czech Academy of Sciences Publication Activity Database

    Vítek, S.; Páta, P.; Koten, Pavel; Fliegel, K.

    2016-01-01

    Roč. 16, č. 9 (2016), 1493/1-1493/10 ISSN 1424-8220 R&D Projects: GA ČR GA14-25251S Institutional support: RVO:67985815 Keywords : faint meteor shower * meteoroid * CCD camera Subject RIV: JA - Electronics ; Optoelectronics, Electrical Engineering Impact factor: 2.677, year: 2016

  18. Lagrangian evaluation of convective shower characteristics in a convection-permitting model

    Directory of Open Access Journals (Sweden)

    Erwan Brisson

    2018-01-01

    Full Text Available Convection-permitting models (CPMs have proven their usefulness in representing precipitation on a sub-daily scale. However, investigations on sub-hourly scales are still lacking, even though these are the scales for which showers exhibit the most variability. A Lagrangian approach is implemented here to evaluate the representation of showers in a CPM, using the limited-area climate model COSMO-CLM. This approach consists of tracking 5‑min precipitation fields to retrieve different features of showers (e.g., temporal pattern, horizontal speed, lifetime. In total, 312 cases are simulated at a resolution of 0.01 ° over Central Germany, and among these cases, 78 are evaluated against a radar dataset. The model is able to represent most observed features for different types of convective cells. In addition, the CPM reproduced well the observed relationship between the precipitation characteristics and temperature indicating that the COSMO-CLM model is sophisticated enough to represent the climatological features of showers.

  19. MAP Kinase Cascades in Plant Innate Immunity

    Directory of Open Access Journals (Sweden)

    Magnus Wohlfahrt Rasmussen

    2012-07-01

    Full Text Available Plant mitogen-activated protein kinase (MAPK cascades generally transduce extracellular stimuli into cellular responses. These stimuli include the perception of pathogen-associated molecular patterns (PAMPs by host transmembrane pattern recognition receptors (PRRs which trigger MAPK-dependent innate immune responses. In the model Arabidopsis, molecular genetic evidence implicates a number of MAPK cascade components in PAMP signaling, and in responses to immunity-related phytohormones such as ethylene, jasmonate and salicylate. In a few cases, cascade components have been directly linked to the transcription of target genes or to the regulation of phytohormone synthesis. Thus MAPKs are obvious targets for bacterial effector proteins and are likely guardees of resistance (R proteins, which mediate defense signaling in response to the action of effectors, or effector-triggered immunity (ETI. This mini-review discusses recent progress in this field with a focus on the Arabidopsis MAPKs MPK3, 4, 6 and 11 in their apparent pathways.

  20. Epidemic and Cascading Survivability of Complex Networks

    DEFF Research Database (Denmark)

    Manzano, Marc; Calle, Eusebi; Ripoll, Jordi

    2014-01-01

    Our society nowadays is governed by complex networks, examples being the power grids, telecommunication networks, biological networks, and social networks. It has become of paramount importance to understand and characterize the dynamic events (e.g. failures) that might happen in these complex...... networks. For this reason, in this paper, we propose two measures to evaluate the vulnerability of complex networks in two different dynamic multiple failure scenarios: epidemic-like and cascading failures. Firstly, we present epidemic survivability ( ES ), a new network measure that describes...... the vulnerability of each node of a network under a specific epidemic intensity. Secondly, we propose cascading survivability ( CS ), which characterizes how potentially injurious a node is according to a cascading failure scenario. Then, we show that by using the distribution of values obtained from ES and CS...

  1. Non-spill control squared cascade

    International Nuclear Information System (INIS)

    Kai, Tsunetoshi; Inoue, Yoshiya; Oya, Akio; Suemori, Nobuo.

    1974-01-01

    Object: To reduce a mixed loss thus enhancing separating efficiency by the provision of a simple arrangement wherein a reflux portion in a conventional spill control squared cascade is replaced by a special stage including centrifugal separators. Structure: Steps in the form of a square cascade, in which a plurality of centrifugal separators are connected by pipe lines, are accumulated in multistage fashion to form a squared cascade. Between the adjoining steps is disposed a special stage including a centrifugal separator which receives both lean flow from the upper step and rich flow from the lower step. The centrifugal separator in the special stage has its rich side connected to the upper step and its lean side connected to the lower step. Special stages are each disposed at the upper side of the uppermost step and at the lower side of the lowermost step. (Kamimura, M.)

  2. Cascade enzymatic reactions for efficient carbon sequestration.

    Science.gov (United States)

    Xia, Shunxiang; Zhao, Xueyan; Frigo-Vaz, Benjamin; Zheng, Wenyun; Kim, Jungbae; Wang, Ping

    2015-04-01

    Thermochemical processes developed for carbon capture and storage (CCS) offer high carbon capture capacities, but are generally hampered by low energy efficiency. Reversible cascade enzyme reactions are examined in this work for energy-efficient carbon sequestration. By integrating the reactions of two key enzymes of RTCA cycle, isocitrate dehydrogenase and aconitase, we demonstrate that intensified carbon capture can be realized through such cascade enzymatic reactions. Experiments show that enhanced thermodynamic driving force for carbon conversion can be attained via pH control under ambient conditions, and that the cascade reactions have the potential to capture 0.5 mol carbon at pH 6 for each mole of substrate applied. Overall it manifests that the carbon capture capacity of biocatalytic reactions, in addition to be energy efficient, can also be ultimately intensified to approach those realized with chemical absorbents such as MEA. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Improved bound on isotropic Lorentz violation in the photon sector from extensive air showers

    Science.gov (United States)

    Klinkhamer, F. R.; Niechciol, M.; Risse, M.

    2017-12-01

    Cosmic rays have extremely high particle energies (up to 1 020 eV ) and can be used to search for violations of Lorentz invariance. We consider isotropic nonbirefringent Lorentz violation in the photon sector for the case of a photon velocity larger than the maximum attainable velocity of the standard fermions. Up to now, Earth-based bounds on this type of Lorentz violation have been determined from observations of TeV gamma rays. Here, we elaborate on a novel approach to test Lorentz invariance with greatly improved sensitivity. This approach is based on investigating extensive air showers which are induced by cosmic-ray particles in the Earth's atmosphere. We study the impact of two Lorentz-violating decay processes on the longitudinal development of air showers, notably the atmospheric depth of the shower maximum Xmax. Specifically, the two Lorentz-violating decay processes considered are photon decay into an electron-positron pair and modified neutral-pion decay into two photons. We use Monte Carlo simulations performed with the conex code which was extended to include these two Lorentz-violating decay processes at a magnitude allowed by the best previous Earth-based bound. Compared to standard physics, these Lorentz-violating decay processes reduce the average Xmax for showers with primary energies above 1 018 eV by an amount that is significantly larger than the average resolution of current air shower experiments. Comparing the simulations of the average Xmax to observations, new Earth-based bounds on this type of Lorentz violation are obtained, which are better than the previous bounds by more than three orders of magnitude. Prospects of further studies are also discussed.

  4. Necessity and effect of combating Legionella pneumophila in municipal shower systems.

    Science.gov (United States)

    Wiik, Ragnhild; Krøvel, Anne Vatland

    2014-01-01

    The objective was to obtain research-based, holistic knowledge about necessity and effect of practiced measures against L. pneumophila in municipal shower systems in Stavanger, Norway. The effects of hot water treatment and membrane-filtering were investigated and compared to no intervention at all. The studies were done under real-world conditions. Additionally, a surveillance pilot study of municipal showers in Stavanger was performed. The validity of high total plate count (TPC) as an indication of L. pneumophila was evaluated. A simplified method, named "dripping method", for detection and quantification of L. pneumophila was developed. The sensitivity of the dripping method is 5 colony-forming units of L. pneumophila/ml. The transference of L. pneumophila from shower water to aerosols was studied. Interviews and observational studies among the stakeholders were done in order to identify patterns of communication and behavior in a Legionella risk perspective. No substantial effects of the measures against L. pneumophila were demonstrated, except for a distally placed membrane filter. No significant positive correlation between TPC and L. pneumophila concentrations were found. L. pneumophila serogroup 2-14 was demonstrated in 21% of the 29 buildings tested in the surveillance pilot. Relatively few cells of L. pneumophila were transferred from shower water to aerosols. Anxiety appeared as the major driving force in the risk governance of Legionella. In conclusion, the risk of acquiring Legionnaires' disease from municipal shower systems is evaluated as low and uncertain. By eliminating ineffective approaches, targeted Legionella risk governance can be practiced. Risk management by surveillance is evaluated as appropriate.

  5. Formation and past evolution of the showers of 96P/Machholz complex

    Science.gov (United States)

    Abedin, Abedin; Wiegert, Paul; Janches, Diego; Pokorný, Petr; Brown, Peter; Hormaechea, Jose Luis

    2018-01-01

    In this work we model the dynamical evolution of meteoroid streams of comet 96P/Machholz, and the largest member of the Marsden sunskirters, comet P/1999 J6. We simultaneously fit the characteristics of eight meteor showers which have been proposed to be linked to the complex, using observations from a range of techniques - visual, video, TV and radar. The aim is to obtain a self-consistent scenario of past capture of a large comet into a short-period orbit, and its subsequent fragmentation history. Moreover, we also aim to constrain the dominant parent of these showers. The fit of our simulated shower characteristics to observations is consistent with the scenario of a capture of a proto-comet 96P/Machholz by Jupiter circa 20000 BCE, and a subsequent major breakup around 100-950 CE which resulted in the formation of the Marsden group of comets. We find that the Marsden group of comets are not the immediate parents of the daytime Arietids and Northern and Southern δ-Aquariids, as previously suggested. In fact, the hypothesis that the Northern δ-Aquariids are related to the Marsden group of comets is not supported by this study. The bulk of the observational characteristics of all eight showers can be explained by meteoroid ejection primarily from comet 96P/Machholz between 10000 BCE and 20000 BCE. Assuming the Marsden group of comets originated between 100 CE-950 CE, we conclude that sunskirting comets contribute mainly to the meteoroid stream near the time of the peak of the daytime Arietids, Southern δ-Aquariids, κ-Velids. Finally, we find that the meteor showers identified by Babadzhanov and Obrubov (1992) as the α-Cetids, the Ursids and Carinids correspond to the daytime λ-Taurids, the November ι-Draconids or December α-Draconids and the θ-Carinids.

  6. Simulation studies of reconstruction of hadron shower direction in INO ICAL detector

    Science.gov (United States)

    Devi, M. M.; Dighe, A.; Indumathi, D.; Lakshmi, S. M.

    2018-03-01

    The proposed Iron Calorimeter (ICAL) at India-based Neutrino Observatory (INO) will be a 50 kt magnetised iron detector for the detection of atmospheric neutrinos. The atmospheric neutrinos interact via both charged current (CC) and neutral current (NC) interactions with the target iron to produce the detectable final state particles. While CC νμ (bar nuμ) leave a muon track and a hadron shower in the detector, the NC will leave only a hadron shower apart from the secondary invisible neutrino. A GEANT4 based simulation studies to reconstruct hadron showers in CC and NC, using two techniques namely the Orientation Matrix Method (OMM) and the Raw Hit Method (RHM) are presented here. While OMM requires information about the interaction vertex obtained from muon track reconstruction, RHM requires only the shower hit positions and timings and no vertex information and hence can be used for NC events as well. Hadrons from neutrino events generated with NUANCE neutrino generator are analysed. For hadrons in the energy range 0.5–15 GeV produced in CC νμ and bar nuμ interactions, a Δθ'h resolution of around 19o‑9o (around 20.5o‑12o) is obtained in the |cosθ'h|=[0.8, 1] bin with OMM (RHM). For NC events in the same true energy and direction bins, Δθ'h resolution varies from around 20.5o‑13o, from RHM only. OMM (RHM) gives a resolution of about 55o‑20o (38o‑14o) for the angle between the muon and the hadron shower, βμ h', in the [E'had;cos θ'h] range [0.5–15 GeV; [0.8,1.0

  7. Piscivores, Trophic Cascades, and Lake Management

    Directory of Open Access Journals (Sweden)

    Ray W. Drenner

    2002-01-01

    Full Text Available The concept of cascading trophic interactions predicts that an increase in piscivore biomass in lakes will result in decreased planktivorous fish biomass, increased herbivorous zooplankton biomass, and decreased phytoplankton biomass. Though often accepted as a paradigm in the ecological literature and adopted by lake managers as a basis for lake management strategies, the trophic cascading interactions hypothesis has not received the unequivocal support (in the form of rigorous experimental testing that might be expected of a paradigm. Here we review field experiments and surveys, testing the hypothesis that effects of increasing piscivore biomass will cascade down through the food web yielding a decline in phytoplankton biomass. We found 39 studies in the scientific literature examining piscivore effects on phytoplankton biomass. Of the studies, 22 were confounded by supplemental manipulations (e.g., simultaneous reduction of nutrients or removal of planktivores and could not be used to assess piscivore effects. Of the 17 nonconfounded studies, most did not find piscivore effects on phytoplankton biomass and therefore did not support the trophic cascading interactions hypothesis. However, the trophic cascading interactions hypothesis also predicts that lake systems containing piscivores will have lower phytoplankton biomass for any given phosphorus concentration. Based on regression analyses of chlorophyll�total phosphorus relationships in the 17 nonconfounded piscivore studies, this aspect of the trophic cascading interactions hypothesis was supported. The slope of the chlorophyll vs. total phosphorus regression was lower in lakes with planktivores and piscivores compared with lakes containing only planktivores but no piscivores. We hypothesize that this slope can be used as an indicator of “functional piscivory” and that communities with extremes of functional piscivory (zero and very high represent classical 3- and 4-trophic level

  8. Volcano geodesy in the Cascade arc, USA

    Science.gov (United States)

    Poland, Michael; Lisowski, Michael; Dzurisin, Daniel; Kramer, Rebecca; McLay, Megan; Pauk, Benjamin

    2017-01-01

    Experience during historical time throughout the Cascade arc and the lack of deep-seated deformation prior to the two most recent eruptions of Mount St. Helens might lead one to infer that Cascade volcanoes are generally quiescent and, specifically, show no signs of geodetic change until they are about to erupt. Several decades of geodetic data, however, tell a different story. Ground- and space-based deformation studies have identified surface displacements at five of the 13 major Cascade arc volcanoes that lie in the USA (Mount Baker, Mount St. Helens, South Sister, Medicine Lake, and Lassen volcanic center). No deformation has been detected at five volcanoes (Mount Rainier, Mount Hood, Newberry Volcano, Crater Lake, and Mount Shasta), and there are not sufficient data at the remaining three (Glacier Peak, Mount Adams, and Mount Jefferson) for a rigorous assessment. In addition, gravity change has been measured at two of the three locations where surveys have been repeated (Mount St. Helens and Mount Baker show changes, while South Sister does not). Broad deformation patterns associated with heavily forested and ice-clad Cascade volcanoes are generally characterized by low displacement rates, in the range of millimeters to a few centimeters per year, and are overprinted by larger tectonic motions of several centimeters per year. Continuous GPS is therefore the best means of tracking temporal changes in deformation of Cascade volcanoes and also for characterizing tectonic signals so that they may be distinguished from volcanic sources. Better spatial resolution of volcano deformation can be obtained through the use of campaign GPS, semipermanent GPS, and interferometric synthetic aperture radar observations, which leverage the accumulation of displacements over time to improve signal to noise. Deformation source mechanisms in the Cascades are diverse and include magma accumulation and withdrawal, post-emplacement cooling of recent volcanic deposits, magmatic

  9. Dynamics of soliton cascades in fiber amplifiers.

    Science.gov (United States)

    Arteaga-Sierra, F R; Antikainen, A; Agrawal, Govind P

    2016-11-15

    We study numerically the formation of cascading solitons when femtosecond optical pulses are launched into a fiber amplifier with less energy than required to form a soliton of equal duration. As the pulse is amplified, cascaded fundamental solitons are created at different distances, without soliton fission, as each fundamental soliton moves outside the gain bandwidth through the Raman-induced spectral shifts. As a result, each input pulse creates multiple, temporally separated, ultrashort pulses of different wavelengths at the amplifier output. The number of pulses depends not only on the total gain of the amplifier but also on the width of the input pulse.

  10. Cascade Processes in Muonic Hydrogen Atoms

    International Nuclear Information System (INIS)

    Faifman, M. P.; Men'Shikov, L. I.

    2001-01-01

    The QCMC scheme created earlier for cascade calculations in heavy hadronic atoms of hydrogen isotopes has been modified and applied to the study of cascade processes in the μp muonic hydrogen atoms. The distribution of μp atoms over kinetic energies has been obtained and the yields of K-series X-rays per one stopped muon have been calculated.Comparison with experimental data indicated directly that for muonic and pionic atoms new types of non-radiative transitions are essential, while they are negligible for heavy (kaonic, antiprotonic, etc.) atoms. These processes have been considered and their probabilities have been estimated.

  11. Investigation of a spatial distribution function of Cherenkov radiation of extensive air showers at a Samarkand State Univirsity device

    International Nuclear Information System (INIS)

    Makhmudov, B.M.; Alimov, T.A.; Aliev, N.A.

    1982-01-01

    The spatial distribution function (SDF) of the Cherenkov radiation of extensive air showers (EAS) in the primary energy range of 10 14 -10 16 eV is studied using the Samarkand device designed for the investigation of EAS. The SDF are presented for two shower groups in a particle number and for zenith angles of theta 6 and for the second group N is equal to 2.23x10 5 . The shower maximum depth is found. The magnitude of 580+-50 gxcm - 2 is obtained for the first group and 400+-50 gxcm - 2 is obtained for the second group

  12. EDITORIAL A CASCADE OF BIOCHEMICAL AND PHYSIOLOGICAL ...

    African Journals Online (AJOL)

    pharm-chem

    A CASCADE OF BIOCHEMICAL AND PHYSIOLOGICAL MARKERS IN PATHOLOGICAL. DISORDERS. A few years ago, a neurophysiology lecturer in the Department of Medical Physiology, University of. Nairobi, was doing ... from haemolysis of RBC is rapidly distributed into cells and excreted in kidney. It would have been.

  13. Cascading effects of overfishing marine systems

    NARCIS (Netherlands)

    Scheffer, M.; Carpenter, S.; Young, de B.

    2005-01-01

    Profound indirect ecosystem effects of overfishing have been shown for coastal systems such as coral reefs and kelp forests. A new study from the ecosystem off the Canadian east coast now reveals that the elimination of large predatory fish can also cause marked cascading effects on the pelagic food

  14. Dynamics of cascade processes of muonic atoms

    International Nuclear Information System (INIS)

    Kalantari, Z.; Pirahmadian, M. H.; Ebrahimi, A.

    2006-01-01

    Studies on exotic atoms are important in different ways. They are important for strong interaction with nucleus and the theory of QCD in low energies. They are also important in muon catalyzed fusion. Their properties can be revealed by studies on cascade of muonic atoms. In this paper, unlike the others, we do not consider the kinetic energy of muonic atoms, constant (the kinetic energy of muonic atoms can vary due to cascade processes). We have used multi group method. The energy dependence of the rates of collisional cascade processes can take into account by this method. In addition, the energy spectra of muonic atoms in the ground state are calculated. For this purpose we divided the energy spectrum to 10 groups, and then use the rate of external Auger effect, Coulomb de-excitation, muon transfer and elastic scattering to solve the dynamics of cascade processes in each group. These equations are coupled linear differential equations. To solve them we use the Runge-Kutta method in the fourth order. One of the conclusions of this paper is that, this energy spectrum is not Maxwellian distribution. Finally our results are compared with the results of the Monte-Carlo simulation.

  15. Geothermal research, Oregon Cascades: Final technical report

    Energy Technology Data Exchange (ETDEWEB)

    Priest, G.R.; Black, G.L.

    1988-10-27

    Previous USDOE-funded geothermal studies have produced an extensive temperature gradient and heat flow data base for the State of Oregon. One of the important features identified as a result of these studies is a rapid transition from heat flow values on the order of 40 mW/m/sup 2/ in the Willamette Valley and Western Cascades to values of greater than or equal to100 mW/m/sup 2/ in the High Cascades and the eastern portion of the Western Cascades. These data indicate that the Cascade Range in Oregon has potential as a major geothermal province and stimulated much of the later work completed by government agencies and private industry. Additional data generated as a result of this grant and published in DOGAMI Open-File Report 0-86-2 further define the location and magnitude of this transition zone. In addition, abundant data collected from the vicinity of Breitenbush and Austin Hot Springs have permitted the formulation of relatively detailed models of these hydrothermal systems. These models are published in DOGAMI Open-File Report 0-88-5. Task 1.2 of the Deliverables section of Amendment M001 is fulfilled by DOGAMI publication GMS-48, Geologic map of the McKenzie Bridge quadrangle, Lane County, Oregon. This map was printed in October, 1988, and is part of the final submission to USDOE. 8 refs.

  16. Gene regulation by MAP kinase cascades

    DEFF Research Database (Denmark)

    Fiil, Berthe Katrine; Petersen, Klaus; Petersen, Morten

    2009-01-01

    Mitogen-activated protein kinase (MAPK) cascades are signaling modules that transduce extracellular stimuli to a range of cellular responses. Research in yeast and metazoans has shown that MAPK-mediated phosphorylation directly or indirectly regulates the activity of transcription factors. Plant ...

  17. MID-INFRARED QUANTUM CASCADE LASERS

    African Journals Online (AJOL)

    2012-11-03

    Nov 3, 2012 ... Abstract. Quantum cascade lasers (QCL) based on intersubband transitions operating at room temperature in the mid-infrared or 'molecular fingerprint' spectral region (3.4–17 im) have been found useful for several applications including environmental sensing, pollution monitoring, and medical appli-.

  18. Population analysis for atomic cascade decay processes

    International Nuclear Information System (INIS)

    Suto, Keiko; Kagawa, Takashi; Futaba, Kaoru

    1998-01-01

    Down-stream cascade decay processes in atomic systems are analyzed by solving a coupled rate equation for which an analytical solution for a population in each excited state is obtained. Some typical numerical examples for populations to interpret the decay passes connecting to features of optical or electron spectra observed in various collision experiments are also given. (author)

  19. Quantum-engineered interband cascade photovoltaic devices

    Energy Technology Data Exchange (ETDEWEB)

    Razeghi, Manijeh; Tournié, Eric; Brown, Gail J.; Yang, Rui Q.; Lotfi, Hossein; Li, Lu; Hinkey, Robert T.; Ye, Hao; Klem, John F.; Lei, L.; Mishima, T. D.; Keay, J. C.; Santos, M. B.; Johnson, M. B.

    2013-12-18

    Quantum-engineered multiple stage photovoltaic (PV) devices are explored based on InAs/GaSb/AlSb interband cascade (IC) structures. These ICPV devices employ multiple discrete absorbers that are connected in series by widebandgap unipolar barriers using type-II heterostructure interfaces for facilitating carrier transport between cascade stages similar to IC lasers. The discrete architecture is beneficial for improving the collection efficiency and for spectral splitting by utilizing absorbers with different bandgaps. As such, the photo-voltages from each individual cascade stage in an ICPV device add together, creating a high overall open-circuit voltage, similar to conventional multi-junction tandem solar cells. Furthermore, photo-generated carriers can be collected with nearly 100% efficiency in each stage. This is because the carriers travel over only a single cascade stage, designed to be shorter than a typical diffusion length. The approach is of significant importance for operation at high temperatures where the diffusion length is reduced. Here, we will present our recent progress in the study of ICPV devices, which includes the demonstration of ICPV devices at room temperature and above with narrow bandgaps (e.g. 0.23 eV) and high open-circuit voltages. © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.

  20. Cascade theory in isotopic separation processes; Theorie des cascades en separation isotopique

    Energy Technology Data Exchange (ETDEWEB)

    Agostini, J.P.

    1994-06-01

    Three main areas are developed within the scope of this work: - the first one is devoted to fundamentals: separative power, value function, ideal cascade and square cascade. Applications to two main cases are carried out, namely: Study of binary isotopic mix, Study of processes with a small enrichment coefficient. - The second one is devoted to cascade coupling -high-flux coupling (more widely used and better known) as well as low-flux coupling are presented and compared to one another. - The third one is an outlook on problems linked to cascade transients. Those problem are somewhat intricate and their interest lies mainly into two areas: economics where the start-up time may have a large influence on the interests paid during the construction and start-up period, military productions where the start-up time has a direct bearing on the production schedule. (author). 50 figs. 3 annexes. 12 refs. 6 tabs.

  1. Cascading Generative Adversarial Networks for Targeted

    KAUST Repository

    Hamdi, Abdullah

    2018-04-09

    Abundance of labelled data played a crucial role in the recent developments in computer vision, but that faces problems like scalability and transferability to the wild. One alternative approach is to utilize the data without labels, i.e. unsupervised learning, in learning valuable information and put it in use to tackle vision problems. Generative Adversarial Networks (GANs) have gained momentum for their ability to model image distributions in unsupervised manner. They learn to emulate the training set and that enables sampling from that domain and using the knowledge learned for useful applications. Several methods proposed enhancing GANs, including regularizing the loss with some feature matching. We seek to push GANs beyond the data in the training and try to explore unseen territory in the image manifold. We first propose a new regularizer for GAN based on K-Nearest Neighbor (K-NN) selective feature matching to a target set Y in high-level feature space, during the adversarial training of GAN on the base set X, and we call this novel model K-GAN. We show that minimizing the added term follows from cross-entropy minimization between the distributions of GAN and set Y. Then, we introduce a cascaded framework for GANs that try to address the task of imagining a new distribution that combines the base set X and target set Y by cascading sampling GANs with translation GANs, and we dub the cascade of such GANs as the Imaginative Adversarial Network (IAN). Several cascades are trained on a collected dataset Zoo-Faces and generated innovative samples are shown, including from K-GAN cascade. We conduct an objective and subjective evaluation for different IAN setups in the addressed task of generating innovative samples and we show the effect of regularizing GAN on different scores. We conclude with some useful applications for these IANs, like multi-domain manifold traversing.

  2. Haptic characterization of human skin in vivo in response to shower gels using a magnetic levitation device.

    Science.gov (United States)

    Yardley, R; Fan, A; Masters, J; Mascaro, S

    2016-02-01

    Skin products such as shower gels have a direct impact on skin health and wellness. Although qualitative haptic characterization through explicit, verbal measures in consumer studies are often sufficient for general comparison on consumer perceived skin feel, a quantitative approach is desired to characterize minute changes in skin condition in response to various skin products. Prior research has sought to characterize the haptic properties of human skin in vitro and in vivo, but very few studies have compared the haptic effects of commercial skin products having relatively similar formulations. In addition, related studies have typically utilized simple, low-precision devices and fixtures. The purpose of this study was to use a precision magnetic levitation haptic device to characterize the frictional properties of human skin in vivo before, during, and after treatment with commercially available shower gels, to capture the entire cycle of consumer experience on skin feel. A hybrid force-position control algorithm was used to control a precision magnetic levitation haptic device with silicone tactor to stroke the human skin (on the volar forearm) in vivo. Position and force data were collected from 32 human subjects using eight different commercially available shower gels, while stroking the skin before, during, and after treatment. The data were analyzed to produce coefficients of friction and viscous damping constant, which were used as metrics for comparing the effects of each shower gel type. Other factors investigated include skin test location, order, and subject age and gender. Results showed significant differences between the effects of eight various shower gels, especially after accounting for variance between subjects. Most notably, Shower Gel four with high level of petrolatum, along with Shower Gels five and six with low levels of castoryl maleate (a skin lipid analog), as well as Shower Gel two with high levels of vegetable oils yielded higher skin

  3. Evaluation of human exposure to metals from some commonly used bathing soaps and shower gels in Nigeria.

    Science.gov (United States)

    Iwegbue, Chukwujindu M A; Emakunu, Omotekoro S; Nwajei, Godwin E; Bassey, Francisca I; Martincigh, Bice S

    2017-02-01

    The concentrations of nine metals (Cd, Pb, Ni, Cr, Co, Cu, Fe, Mn and Zn) were measured in selected brands of medicated, moisturizing and skin-lightening soaps and shower gels with the aim of evaluating the human health risk associated with metal exposure from the use of these products. The concentrations of metals in these products were determined by means of atomic absorption spectrophotometry after sample digestion with a mixture of acids. The concentration ranges of the metals in the bathing soaps and shower gels were found to be: shower gels were below their respective provisional tolerable daily intake/or recommended daily intake values. The margin of safety values obtained for the metals were greater than 100 which indicated that there was no significant risk to the users of these brands of bathing soaps and shower gels, except in the case of Co. Copyright © 2016 Elsevier Inc. All rights reserved.

  4. Numerical study of the electron and muon lateral distribution in atmospheric showers of high energy cosmic rays

    Directory of Open Access Journals (Sweden)

    Georgios Atreidis

    2017-01-01

    Full Text Available The lateral distribution of an atmospheric shower depends on the characteristics of the high energy interactions and the type of the primary particle. The influence of the primary particle in the secondary development of the shower into the atmosphere, is studied by analyzing the lateral distribution of electron and muon showers having as primary particle, proton, photon or iron nucleus. This study of the lateral distribution can provide useful conclusions for the mass and energy of the primary particle. This paper compares the data that we get from simulations with CORSIKA program with experimental data and the theoretical NKG function expressing lateral electron and muon distribution. Then we modify the original NKG function to fit better to the simulation data and propose a method for determining the mass of the original particle started the atmospheric shower.

  5. Reduction in 24-Hour Plasma Testosterone Levels in Subjects Who Showered 15 or 30 Minutes After Application of Testosterone Gel

    NARCIS (Netherlands)

    de Ronde, W.; Vogel, S.; Bui, H.N.; Heijboer, A.C.

    2011-01-01

    Study Objective. To investigate whether showering, to prevent the involuntary transfer of testosterone to others through skin contact, either 15 or 30 minutes after application of testosterone gel would significantly affect plasma testosterone levels. Design. Prospective 3-way crossover trial.

  6. Measurement of the Depth of Maximum of Extensive Air Showers above 10^18 eV

    Energy Technology Data Exchange (ETDEWEB)

    Abraham, J.; /Buenos Aires, CONICET; Abreu, P.; /Lisbon, IST; Aglietta, M.; /Turin U. /INFN, Turin; Ahn, E.J.; /Fermilab; Allard, D.; /APC, Paris; Allekotte, I.; /Centro Atomico Bariloche /Buenos Aires, CONICET; Allen, J.; /New York U.; Alvarez-Muniz, J.; /Santiago de Compostela U.; Ambrosio, M.; /Naples U.; Anchordoqui, L.; /Wisconsin U., Milwaukee; Andringa, S.; /Lisbon, IST /Boskovic Inst., Zagreb

    2010-02-01

    We describe the measurement of the depth of maximum, X{sub max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10{sup 18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{sub -21}{sup +35}) g/cm{sup 2}/decade below 10{sup 18.24 {+-} 0.05}eV, and (24 {+-} 3) g/cm{sup 2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{sup 2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  7. Measurement of the depth of maximum of extensive air showers above 10{18} eV.

    Science.gov (United States)

    Abraham, J; Abreu, P; Aglietta, M; Ahn, E J; Allard, D; Allekotte, I; Allen, J; Alvarez-Muñiz, J; Ambrosio, M; Anchordoqui, L; Andringa, S; Anticić, T; Anzalone, A; Aramo, C; Arganda, E; Arisaka, K; Arqueros, F; Asorey, H; Assis, P; Aublin, J; Ave, M; Avila, G; Bäcker, T; Badagnani, D; Balzer, M; Barber, K B; Barbosa, A F; Barroso, S L C; Baughman, B; Bauleo, P; Beatty, J J; Becker, B R; Becker, K H; Bellétoile, A; Bellido, J A; Benzvi, S; Berat, C; Bergmann, T; Bertou, X; Biermann, P L; Billoir, P; Blanch-Bigas, O; Blanco, F; Blanco, M; Bleve, C; Blümer, H; Bohácová, M; Boncioli, D; Bonifazi, C; Bonino, R; Borodai, N; Brack, J; Brogueira, P; Brown, W C; Bruijn, R; Buchholz, P; Bueno, A; Burton, R E; Busca, N G; Caballero-Mora, K S; Caramete, L; Caruso, R; Castellina, A; Catalano, O; Cataldi, G; Cazon, L; Cester, R; Chauvin, J; Chiavassa, A; Chinellato, J A; Chou, A; Chudoba, J; Clay, R W; Colombo, E; Coluccia, M R; Conceição, R; Contreras, F; Cook, H; Cooper, M J; Coppens, J; Cordier, A; Cotti, U; Coutu, S; Covault, C E; Creusot, A; Criss, A; Cronin, J; Curutiu, A; Dagoret-Campagne, S; Dallier, R; Daumiller, K; Dawson, B R; de Almeida, R M; De Domenico, M; De Donato, C; de Jong, S J; De La Vega, G; de Mello Junior, W J M; de Mello Neto, J R T; De Mitri, I; de Souza, V; de Vries, K D; Decerprit, G; Del Peral, L; Deligny, O; Della Selva, A; Delle Fratte, C; Dembinski, H; Di Giulio, C; Diaz, J C; Díaz Castro, M L; Diep, P N; Dobrigkeit, C; D'Olivo, J C; Dong, P N; Dorofeev, A; Dos Anjos, J C; Dova, M T; D'Urso, D; Dutan, I; Duvernois, M A; Ebr, J; Engel, R; Erdmann, M; Escobar, C O; Etchegoyen, A; Facal San Luis, P; Falcke, H; Farrar, G; Fauth, A C; Fazzini, N; Ferrero, A; Fick, B; Filevich, A; Filipcic, A; Fleck, I; Fliescher, S; Fracchiolla, C E; Fraenkel, E D; Fröhlich, U; Fulgione, W; Gamarra, R F; Gambetta, S; García, B; García Gámez, D; Garcia-Pinto, D; Garrido, X; Gelmini, G; Gemmeke, H; Ghia, P L; Giaccari, U; Giller, M; Glass, H; Goggin, L M; Gold, M S; Golup, G; Gomez Albarracin, F; Gómez Berisso, M; Gonçalves, P; Gonzalez, D; Gonzalez, J G; Góra, D; Gorgi, A; Gouffon, P; Gozzini, S R; Grashorn, E; Grebe, S; Grigat, M; Grillo, A F; Guardincerri, Y; Guarino, F; Guedes, G P; Hague, J D; Halenka, V; Hansen, P; Harari, D; Harmsma, S; Harton, J L; Haungs, A; Hebbeker, T; Heck, D; Herve, A E; Hojvat, C; Holmes, V C; Homola, P; Hörandel, J R; Horneffer, A; Hrabovský, M; Huege, T; Hussain, M; Iarlori, M; Insolia, A; Ionita, F; Italiano, A; Jiraskova, S; Kadija, K; Kaducak, M; Kampert, K H; Karova, T; Kasper, P; Kégl, B; Keilhauer, B; Keivani, A; Kelley, J; Kemp, E; Kieckhafer, R M; Klages, H O; Kleifges, M; Kleinfeller, J; Knapik, R; Knapp, J; Koang, D-H; Krieger, A; Krömer, O; Kruppke-Hansen, D; Kuehn, F; Kuempel, D; Kulbartz, K; Kunka, N; Kusenko, A; La Rosa, G; Lachaud, C; Lago, B L; Lautridou, P; Leão, M S A B; Lebrun, D; Lebrun, P; Lee, J; Leigui de Oliveira, M A; Lemiere, A; Letessier-Selvon, A; Lhenry-Yvon, I; López, R; Lopez Agüera, A; Louedec, K; Lozano Bahilo, J; Lucero, A; Ludwig, M; Lyberis, H; Maccarone, M C; Macolino, C; Maldera, S; Mandat, D; Mantsch, P; Mariazzi, A G; Marin, V; Maris, I C; Marquez Falcon, H R; Marsella, G; Martello, D; Martínez Bravo, O; Mathes, H J; Matthews, J; Matthews, J A J; Matthiae, G; Maurizio, D; Mazur, P O; McEwen, M; Medina-Tanco, G; Melissas, M; Melo, D; Menichetti, E; Menshikov, A; Meurer, C; Micanović, S; Micheletti, M I; Miller, W; Miramonti, L; Mollerach, S; Monasor, M; Monnier Ragaigne, D; Montanet, F; Morales, B; Morello, C; Moreno, E; Moreno, J C; Morris, C; Mostafá, M; Mueller, S; Muller, M A; Mussa, R; Navarra, G; Navarro, J L; Navas, S; Necesal, P; Nellen, L; Nhung, P T; Nierstenhoefer, N; Nitz, D; Nosek, D; Nozka, L; Nyklicek, M; Oehlschläger, J; Olinto, A; Oliva, P; Olmos-Gilbaja, V M; Ortiz, M; Pacheco, N; Pakk Selmi-Dei, D; Palatka, M; Pallotta, J; Palmieri, N; Parente, G; Parizot, E; Parlati, S; Parra, A; Parrisius, J; Parsons, R D; Pastor, S; Paul, T; Pavlidou, V; Payet, K; Pech, M; Pekala, J; Pelayo, R; Pepe, I M; Perrone, L; Pesce, R; Petermann, E; Petrera, S; Petrinca, P; Petrolini, A; Petrov, Y; Petrovic, J; Pfendner, C; Piegaia, R; Pierog, T; Pimenta, M; Pirronello, V; Platino, M; Ponce, V H; Pontz, M; Privitera, P; Prouza, M; Quel, E J; Rautenberg, J; Ravel, O; Ravignani, D; Redondo, A; Revenu, B; Rezende, F A S; Ridky, J; Riggi, S; Risse, M; Ristori, P; Rivière, C; Rizi, V; Robledo, C; Rodriguez, G; Rodriguez Martino, J; Rodriguez Rojo, J; Rodriguez-Cabo, I; Rodríguez-Frías, M D; Ros, G; Rosado, J; Rossler, T; Roth, M; Rouillé-d'Orfeuil, B; Roulet, E; Rovero, A C; Salamida, F; Salazar, H; Salina, G; Sánchez, F; Santander, M; Santo, C E; Santos, E; Santos, E M; Sarazin, F; Sarkar, S; Sato, R; Scharf, N; Scherini, V; Schieler, H; Schiffer, P; Schmidt, A

    2010-03-05

    We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

  8. Hollow Anode Cascading Plasma Focus | Alabraba | Journal of the ...

    African Journals Online (AJOL)

    Using the 3-phase model for each focus event, the 9-phase, two solid disc auxiliary anode cascading plasma focus has been extended to include holes at the center of each cascade anode (hereafter referred to as hollow anode cascading focus) with a view of increasing the neutron yield with each focus event. Results ...

  9. A simple method for potential flow simulation of cascades

    Indian Academy of Sciences (India)

    Keywords. Cascade; turbo-machinery; aerodynamics; conformal mapping. Abstract. A simple method using a combination of conformal mapping and vortex panel method to simulate potential flow in cascades is presented. The cascade is first transformed to a single body using a conformal mapping, and the potential flow ...

  10. Shower development of particles with momenta from 1 to 10 GeV in the CALICE Scintillator-Tungsten HCAL

    CERN Document Server

    LUCACI TIMOCE, A.

    2012-01-01

    We present a study of the showers initiated by low momentum (p 10 GeV) electrons, pions and protons in the highly granular CALICE scintillator-tungsten HCAL. The data were taken at the CERN PS in September-October 2010. The analysis includes energy resolution measurements for each particle type and studies of the longitudinal shower development. The results are compared with several GEANT4 models.

  11. Shower development of particles with momenta from 10 to 100 GeV in the CALICE Scintillator-Tungsten HCAL

    CERN Document Server

    Lucaci-Timoce, A

    2013-01-01

    We present a study of the showers initiated by high momentum (10 ≤ pbeam ≤ 100 GeV) electrons, pions and protons in the highly granular CALICE analogue scintillator-tungsten hadronic calorimeter. The data were taken at the CERN SPS in 2011. The analysis includes measurements of the calorimeter response to each particle type and studies of the longitudinal and radial shower development. The results are compared to several GEANT4 simulation models.

  12. Shower characteristics of particles with momenta up to 100 GeV in the CALICE scintillator-tungsten hadronic calorimeter

    CERN Document Server

    AUTHOR|(CDS)2073690

    2015-01-01

    We present a study of showers initiated by 1–100 GeV positrons, pions, kaons, and protons in the highly granular CALICE analogue scintillator-tungsten hadronic calorimeter. The data were taken at the CERN PS and SPS. The analysis includes measurements of the calorimeter response to each particle type and studies of the longitudinal and radial shower development. The results are compared to several Geant4 simulation models.

  13. Simulation studies of the information content of muon arrival time observations of high energy extensive air showers

    International Nuclear Information System (INIS)

    Brancus, I.; Duma, M.; Badea, A. F.; Aiftimiei, C.; Rebel, M. H.; Oehlschlaeger, J.

    2001-01-01

    By extensive Monte Carlo calculations, using the air shower simulation code CORSIKA, EAS muon arrival time distributions and EAS time profiles up to 320 m distances from the shower centre have been generated, for proton, oxygen and iron induced showers using different hadronic interaction models as Monte Carlo generators. The model dependence and mass discriminating features have been scrutinized for three energy ranges, (1-1.7783) 10 15 eV, (1.-1.78) 10 16 eV and (1.78-3.16) 10 16 eV, by use of non-parametric statistical inference method applied to multidimensional distributions, correlating the EAS time quantities with different other EAS observables. The correlations of local muon arrival times with the local muon density and the shower age indicate a good mass separation quality at larger shower distances. The best discrimination was obtained by adding the correlation with N μ tr quantity. The comparison between 'local times', with reference to the first registered muon and 'global times' with reference to the arrival time of the shower core, indicates a slightly better mass discrimination in the case of muon 'global' time distributions. (authors)

  14. Collecting Comet Samples by ER-2 Aircraft: Cosmic Dust Collection During the Draconid Meteor Shower in October 2012

    Science.gov (United States)

    Bastien, Ron; Burkett, P. J.; Rodriquez, M.; Frank, D.; Gonzalez, C.; Robinson, G.-A.; Zolensky, M.; Brown, P.; Campbell-Brown, M.; Broce, S.; hide

    2014-01-01

    Many tons of dust grains, including samples of asteroids and comets, fall from space into the Earth's atmosphere each day. NASA periodically collects some of these particles from the Earth's stratosphere using sticky collectors mounted on NASA's high-flying aircraft. Sometimes, especially when the Earth experiences a known meteor shower, a special opportunity is presented to associate cosmic dust particles with a known source. NASA JSC's Cosmic Dust Collection Program has made special attempts to collect dust from particular meteor showers and asteroid families when flights can be planned well in advance. However, it has rarely been possible to make collections on very short notice. In 2012, the Draconid meteor shower presented that opportunity. The Draconid meteor shower, originating from Comet 21P/Giacobini-Zinner, has produced both outbursts and storms several times during the last century, but the 2012 event was not predicted to be much of a show. Because of these predictions, the Cosmic Dust team had not targeted a stratospheric collection effort for the Draconids, despite the fact that they have one of the slowest atmospheric entry velocities (23 km/s) of any comet shower, and thus offer significant possibilities of successful dust capture. However, radar measurements obtained by the Canadian Meteor Orbit Radar during the 2012 Draconids shower indicated a meteor storm did occur October 8 with a peak at 16:38 (+/-5 min) UTC for a total duration of approximately 2 hours.

  15. Preliminary Screening a Potential AChE Inhibitor in Thai Golden Shower (Leguminosae mimosoideae Extracts

    Directory of Open Access Journals (Sweden)

    Jakkaphun Nanuam

    2013-07-01

    Full Text Available Pesticides are used to control pests of agriculture products in many countries including Thailand. Since they can exert harmful effects not only on target pests but also on other useful organisms, alternative agents are investigated. We studied the capacity of the Thai golden shower (Leguminosae mimosoideae extracts (root and pod to inhibit acetyl cholinestarese (AChE in the golden apple snail (Pomacea canaliculata as a pest representative. The results showed that the percentage of AChE inhibition increased with increasing in exposure times. The inhibition expressed the same trend in both male and female apple snails. AChE inhibition was higher in extracts from root than from pod. Chromatography-Mass Spectrometer (GC-MS chromatograms demonstrated anthraquinone, an AChE inhibitor, in extracts of golden shower. Our data indicate that a potential AChE inhibitor tends to accumulate more in the root part than in the pod.

  16. ZZ production in gluon fusion at NLO matched to parton-shower

    CERN Document Server

    Alioli, Simone

    2017-01-01

    We present a calculation of the next-to-leading order (NLO) QCD corrections to the hadroproduction process $gg\\to ZZ \\to e^+e^- \\mu^+ \\mu^-$, matched to the parton shower in the POWHEG framework. We take advantage of the POWHEG BOX tool for the implementation and rely on PYTHIA 8 for the showering and hadronization stages. We fully include $\\gamma^*/Z$ interference effects, while also covering the single-resonant region. For this phenomenological study we focus on four lepton production as a signal process, neglecting all quark mass effects as well as the Higgs-mediated contributions, which are known to be subdominant in this case. We provide predictions from our simulations for the 13 TeV LHC Run II setup, including realistic experimental cuts.

  17. Test of a proportional tube modulus used to localize the electromagnetic showers in a calorimeter

    International Nuclear Information System (INIS)

    Lees, J.-P.

    1981-01-01

    In this work are given results of a test in an electron-hadron beam (5-92 GeV) of the prototype of a position detector. This position detector consists of proportional tubes with charge division readout; it will be used in the end cap electromagnetic calorimeter ('bouchon') of the UA1 experiment at CERN (pantip collisions at a center of mass energy of 540 GeV). This detector gives the position of the showers, and also a coarse value of their energy. Results about properties of the tubes (saturation phenomena, position and energy accuracies) and, then, results about the development of high energy electromagnetic showers in lead-plastic sandwich are given here [fr

  18. Correlation of high energy muons with primary composition in extensive air shower

    Science.gov (United States)

    Chou, C.; Higashi, S.; Hiraoka, N.; Ozaki, S.; Sato, T.; Suwada, T.; Takahasi, T.; Umeda, H.

    1985-01-01

    An experimental investigation of high energy muons above 200 GeV in extensive air showers has been made for studying high energy interaction and primary composition of cosmic rays of energies in the range 10 to the 14th power approx. 10 to the 15th power eV. The muon energies are estimated from the burst sizes initiated by the muons in the rock, which are measured by four layers of proportional counters, each of area 5 x 2.6 sq m, placed at 30 m.w.e. deep, Funasaka tunnel vertically below the air shower array. These results are compared with Monte Carlo simulations based on the scaling model and the fireball model for two primary compositions, all proton and mixed.

  19. Impact of the choice of physics list on GEANT4 simulations of hadronic showers in tungsten

    CERN Document Server

    Speckmayer, P

    2010-01-01

    The development of pion induced showers in a large block of matter (tungsten, lead, iron) is simulated for pions from 1 to 50GeV. Two GEANT4 physics lists (QGSP BERT and QGSP BERT HP) are compared. The deposited energy at each step of the simulation is identified as visible, invisible or escaped. It will be shown, that for tungsten in most of the hadronic showers more than 90% of the energy is deposited visibly if QGSP BERT is used. This fraction drops to only 60% for QGSP BERT HP. The latter fraction is similar to lead, even when QGSP BERT is used for the simulation. The impact of this behaviour on the energy resolution of a sampling calorimeter with scintillator as active material is shown. Although more energy is deposited visibly for QGSP BERT than for QGSP BERT HP, the reconstructed energy resolution is about 5 to 10% percent better for the latter.

  20. Off-shell single-top production at NLO matched to parton showers

    Energy Technology Data Exchange (ETDEWEB)

    Frederix, R. [Physik Department T31, Technische Universität München,James-Franck-Str. 1, D-85748 Garching (Germany); Frixione, S. [INFN - Sezione di Genova,Via Dodecaneso 33, I-16146, Genoa (Italy); Papanastasiou, A.S. [Cavendish Laboratory, University of Cambridge,J.J. Thomson Avenue, CB3 0HE, Cambridge (United Kingdom); Prestel, S. [SLAC National Accelerator Laboratory,2575 Sand Hill Road, Menlo Park, CA 94025-7090 (United States); Torrielli, P. [Dipartimento di Fisica, Università di Torino and INFN - Sezione di Torino,Via P. Giuria 1, I-10125, Turin (Italy)

    2016-06-06

    We study the hadroproduction of a Wb pair in association with a light jet, focusing on the dominant t-channel contribution and including exactly at the matrix-element level all non-resonant and off-shell effects induced by the finite top-quark width. Our simulations are accurate to the next-to-leading order in QCD, and are matched to the HERWIG6 and PYTHIA8 parton showers through the MC@NLO method. We present phenomenological results relevant to the 8 TeV LHC, and carry out a thorough comparison to the case of on-shell t-channel single-top production. We formulate our approach so that it can be applied to the general case of matrix elements that feature coloured intermediate resonances and are matched to parton showers.