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Sample records for experimental elementary particle

  1. Theoretical & Experimental Studies of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    McFarland, Kevin [Univ. of Rochester, NY (United States)

    2012-10-04

    Abstract High energy physics has been one of the signature research programs at the University of Rochester for over 60 years. The group has made leading contributions to experimental discoveries at accelerators and in cosmic rays and has played major roles in developing the theoretical framework that gives us our ``standard model'' of fundamental interactions today. This award from the Department of Energy funded a major portion of that research for more than 20 years. During this time, highlights of the supported work included the discovery of the top quark at the Fermilab Tevatron, the completion of a broad program of physics measurements that verified the electroweak unified theory, the measurement of three generations of neutrino flavor oscillations, and the first observation of a ``Higgs like'' boson at the Large Hadron Collider. The work has resulted in more than 2000 publications over the period of the grant. The principal investigators supported on this grant have been recognized as leaders in the field of elementary particle physics by their peers through numerous awards and leadership positions. Most notable among them is the APS W.K.H. Panofsky Prize awarded to Arie Bodek in 2004, the J.J. Sakurai Prizes awarded to Susumu Okubo and C. Richard Hagen in 2005 and 2010, respectively, the Wigner medal awarded to Susumu Okubo in 2006, and five principal investigators (Das, Demina, McFarland, Orr, Tipton) who received Department of Energy Outstanding Junior Investigator awards during the period of this grant. The University of Rochester Department of Physics and Astronomy, which houses the research group, provides primary salary support for the faculty and has waived most tuition costs for graduate students during the period of this grant. The group also benefits significantly from technical support and infrastructure available at the University which supports the work. The research work of the group has provided educational opportunities

  2. Theoretical and Experimental Studies of Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Evans, Harold G [Indiana University; Kostelecky, V Alan [Indiana University; Musser, James A [Indiana University

    2013-07-29

    The elementary particle physics research program at Indiana University spans a broad range of the most interesting topics in this fundamental field, including important contributions to each of the frontiers identified in the recent report of HEPAP's Particle Physics Prioritization Panel: the Energy Frontier, the Intensity Frontier, and the Cosmic Frontier. Experimentally, we contribute to knowledge at the Energy Frontier through our work on the D0 and ATLAS collaborations. We work at the Intensity Frontier on the MINOS and NOvA experiments and participate in R&D for LBNE. We are also very active on the theoretical side of each of these areas with internationally recognized efforts in phenomenology both in and beyond the Standard Model and in lattice QCD. Finally, although not part of this grant, members of the Indiana University particle physics group have strong involvement in several astrophysics projects at the Cosmic Frontier. Our research efforts are divided into three task areas. The Task A group works on D0 and ATLAS; Task B is our theory group; and Task C contains our MINOS, NOvA, and LBNE (LArTPC) research. Each task includes contributions from faculty, senior scientists, postdocs, graduate and undergraduate students, engineers, technicians, and administrative personnel. This work was supported by DOE Grant DE-FG02-91ER40661. In the following, we describe progress made in the research of each task during the final period of the grant, from November 1, 2009 to April 30, 2013.

  3. (Experimental studies of elementary particle interactions at high energies)

    Energy Technology Data Exchange (ETDEWEB)

    Khuri, N.N.

    1990-01-01

    This report includes descriptions of the combined work of both Tasks B and B{sub 1} at Rockefeller University. Some highlights are worth stressing in this brief introduction. First, one should note the active involvement of two members of our group, Ren and Callaway, in understanding the problem of superconductivity, both high and low {Tc}. This reflects the broad reach of many, but perhaps not all, particle physicists. Second, spurred by the Rockefeller environment, some in our group are also looking at problems in biology. As for our main purpose, I would like to single out the results of Sanda and Morozumi on the {Delta}I = {1/2} rule, the work of Bitar, Ren and myself on a new approach to the path integral, S.Y. Pi's results on Chern-Simons non-relativistic quantum mechanics, and finally the work by Lee and collaborators on the origin of Fermion masses and mixing.

  4. Elementary particles

    Science.gov (United States)

    Fritzsch, Harald; Heusch, Karin

    Introduction -- Electrons and atomic nuclei -- Quantum properties of atoms and particles -- The knives of Democritus -- Quarks inside atomic nuclei -- Quantum electrodynamics -- Quantum chromodynamics -- Mesons, baryons, and quarks -- Electroweak interactions -- Grand unification -- Conclusion.

  5. Elementary particle physics at the University of Florida

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    This report discusses research in the following areas: theoretical elementary particle physics; experimental elementary particle physics; axion project; SSC detector development; and computer acquisition. (LSP).

  6. Elementary particles as signs

    OpenAIRE

    Leonardo CHIATTI

    2014-01-01

    C.S. Peirce’s semiotic approach admits the possibility of natural signic systems. This article explores the possible connection between the concept of elementary particle and the irreducible relations of Peircean semiotics. The potentialities and the limitations of a semiotic vision of elementary physical processes are addressed.

  7. Elementary particle physics

    Science.gov (United States)

    Perkins, D. H.

    1986-01-01

    Elementary particle physics is discussed. Status of the Standard Model of electroweak and strong interactions; phenomena beyond the Standard Model; new accelerator projects; and possible contributions from non-accelerator experiments are examined.

  8. Magnetism of elementary particles

    CERN Document Server

    Vonsovsky, S V

    1975-01-01

    Spin magnetic moment of the electron ; magnetism of the atomic electron shell ; magnetism of nucleons (protons and neutrons) and atomic nuclei ; anomalous magnetic moments of elementary particles ; the magnetic monopole ; non-linear quantum-electrodynamic effects in a magnetic field.

  9. ELEMENTARY PARTICLE INTERACTIONS

    Energy Technology Data Exchange (ETDEWEB)

    EFREMENKO, YURI; HANDLER, THOMAS; KAMYSHKOV, YURI; SIOPSIS, GEORGE; SPANIER, STEFAN

    2013-07-30

    The High-Energy Elementary Particle Interactions group at UT during the last three years worked on the following directions and projects: Collider-based Particle Physics; Neutrino Physics, particularly participation in “NOνA”, “Double Chooz”, and “KamLAND” neutrino experiments; and Theory, including Scattering amplitudes, Quark-gluon plasma; Holographic cosmology; Holographic superconductors; Charge density waves; Striped superconductors; and Holographic FFLO states.

  10. Introduction to elementary particles

    CERN Document Server

    Griffiths, David J

    2008-01-01

    This is the first quantitative treatment of elementary particle theory that is accessible to undergraduates. Using a lively, informal writing style, the author strikes a balance between quantitative rigor and intuitive understanding. The first chapter provides a detailed historical introduction to the subject. Subsequent chapters offer a consistent and modern presentation, covering the quark model, Feynman diagrams, quantum electrodynamics, and gauge theories. A clear introduction to the Feynman rules, using a simple model, helps readers learn the calculational techniques without the complicat

  11. Weak interactions of elementary particles

    CERN Document Server

    Okun, Lev Borisovich

    1965-01-01

    International Series of Monographs in Natural Philosophy, Volume 5: Weak Interaction of Elementary Particles focuses on the composition, properties, and reactions of elementary particles and high energies. The book first discusses elementary particles. Concerns include isotopic invariance in the Sakata model; conservation of fundamental particles; scheme of isomultiplets in the Sakata model; universal, unitary-symmetric strong interaction; and universal weak interaction. The text also focuses on spinors, amplitudes, and currents. Wave function, calculation of traces, five bilinear covariants,

  12. A guide to experimental elementary particle physics literature, 1988--1992. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.I.; Ezhela, V.V.; Filimonov, B.B. [Institute for High Energy Physics, Protvino, Moscow Region (Russian Federation)] [and others

    1993-09-01

    We present an indexed guide to the literature experimental particle physics for the years 1988--1992. About 4,000 papers are indexed by Beam/Target/Momentum, Reaction Momentum (including the final state), Final State Particle, and Accelerator/Detector/Experiment. All indices are cross-referenced to the paper`s title and reference in the ID/Reference/Title Index. The information in this guide is also publicly available from a regularly updated computer database.

  13. A guide to experimental elementary particle physics literature, 1985--1989

    Energy Technology Data Exchange (ETDEWEB)

    Alekhin, S.I.; Bazeeva, V.V.; Ezhela, V.V.; Filimonov, B.B.; Lugovsky, S.B.; Nikolaev, A.S.; Petrova, N.L.; Slabospitsky, S.R.; Striganov, S.I.; Stroganov, Y.G.; Shelkovenko, A.N.; Yuschenko, O.P. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Serpukhov (USSR). Inst. Fiziki Vysokikh Ehnergij); Yost, G.P.; Rittenberg, A.; Armstrong, F.E.; Barnett, R.M.; Simpson, K.H.; Trippe, T.G.; Wagman, G.S.; W

    1990-11-01

    We present an indexed guide to experimental high energy physics literature for the years 1985--1989. No actual data are given, but approximately 3500 papers are indexed by Beam/Target/Momentum, Reaction/Momentum (including the final stare), Final State Particle, and Accelerator/Experiment/ Detector.

  14. Elementary particle physics at the University of Florida. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-01

    This report discusses research in the following areas: theoretical elementary particle physics; experimental elementary particle physics; axion project; SSC detector development; and computer acquisition. (LSP).

  15. Notes on elementary particle physics

    CERN Document Server

    Muirhead, William Hugh

    1972-01-01

    Notes of Elementary Particle Physics is a seven-chapter text that conveys the ideas on the state of elementary particle physics. This book emerged from an introductory course of 30 lectures on the subject given to first-year graduate students at the University of Liverpool. The opening chapter deals with pertinent terminologies in elementary particle physics. The succeeding three chapters cover the concepts of transition amplitudes, probabilities, relativistic wave equations and fields, and the interaction amplitude. The discussion then shifts to tests of electromagnetic interactions, particul

  16. Theoretical Studies in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Collins, John C.; Roiban, Radu S

    2013-04-01

    This final report summarizes work at Penn State University from June 1, 1990 to April 30, 2012. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

  17. Music of elementary particles

    Energy Technology Data Exchange (ETDEWEB)

    Sternheimer, J.

    1983-12-12

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

  18. Elementary Particles A New Approach

    Directory of Open Access Journals (Sweden)

    FranciscoMartnezFlores.

    2015-07-01

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

  19. Supersymmetry in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Peskin, Michael E.; /SLAC

    2008-02-05

    These lectures give a general introduction to supersymmetry, emphasizing its application to models of elementary particle physics at the 100 GeV energy scale. I discuss the following topics: the construction of supersymmetric Lagrangians with scalars, fermions, and gauge bosons, the structure and mass spectrum of the Minimal Supersymmetric Standard Model (MSSM), the measurement of the parameters of the MSSM at high-energy colliders, and the solutions that the MSSM gives to the problems of electroweak symmetry breaking and dark matter.

  20. A research Program in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Sobel, Henry; Molzon, William; Lankford, Andrew; Taffard, Anyes; Whiteson, Daniel; Kirkby, David

    2013-07-25

    Work is reported in: Neutrino Physics, Cosmic Rays and Elementary Particles; Particle Physics and Charged Lepton Flavor Violation; Research in Collider Physics; Dark Energy Studies with BOSS and LSST.

  1. Current experiments in elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Wohl, C.G.; Armstrong, F.E., Oyanagi, Y.; Dodder, D.C.; Ryabov, Yu.G.; Frosch, R.; Olin, A.; Lehar, F.; Moskalev, A.N.; Barkov, B.P.

    1987-03-01

    This report contains summaries of 720 recent and current experiments in elementary particle physics (experiments that finished taking data before 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

  2. Current experiments in elementary particle physics. Revised

    Energy Technology Data Exchange (ETDEWEB)

    Galic, H. [Stanford Univ., CA (United States). Stanford Linear Accelerator Center; Wohl, C.G.; Armstrong, B. [Lawrence Berkeley Lab., CA (United States); Dodder, D.C. [Los Alamos National Lab., NM (United States); Klyukhin, V.I.; Ryabov, Yu.G. [Inst. for High Energy Physics, Serpukhov (Russian Federation); Illarionova, N.S. [Inst. of Theoretical and Experimental Physics, Moscow (Russian Federation); Lehar, F. [CEN Saclay, Gif-sur-Yvette (France); Oyanagi, Y. [Univ. of Tokyo (Japan). Faculty of Sciences; Olin, A. [TRIUMF, Vancouver, BC (Canada); Frosch, R. [Paul Scherrer Inst., Villigen (Switzerland)

    1992-06-01

    This report contains summaries of 584 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1986 are excluded. Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, KEK, LAMPF, Novosibirsk, Paul Scherrer Institut (PSI), Saclay, Serpukhov, SLAC, SSCL, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

  3. Current experiments in elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Wohl, C.G.; Armstrong, F.E.; Trippe, T.G.; Yost, G.P. (Lawrence Berkeley Lab., CA (USA)); Oyanagi, Y. (Tsukuba Univ., Ibaraki (Japan)); Dodder, D.C. (Los Alamos National Lab., NM (USA)); Ryabov, Yu.G.; Slabospitsky, S.R. (Gosudarstvennyj Komitet po Ispol' zovaniyu Atomnoj Ehnergii SSSR, Serpukhov (USSR). Inst. Fiziki Vysokikh Ehnergij); Frosch, R. (Swiss Inst. for Nuclear Research, Villigen (Switzerla

    1989-09-01

    This report contains summaries of 736 current and recent experiments in elementary particle physics (experiments that finished taking data before 1982 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Tokyo Institute of Nuclear Studies, Moscow Institute of Theoretical and Experimental Physics, Joint Institute for Nuclear Research (Dubna), KEK, LAMPF, Novosibirsk, PSI/SIN, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground experiments. Also given are instructions for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries. Properties of the fixed-target beams at most of the laboratories are summarized.

  4. Elementary particle physics in a nutshell

    CERN Document Server

    Tully, Christopher C

    2011-01-01

    The new experiments underway at the Large Hadron Collider at CERN in Switzerland may significantly change our understanding of elementary particle physics and, indeed, the universe. This textbook provides a cutting-edge introduction to the field, preparing first-year graduate students and advanced undergraduates to understand and work in LHC physics at the dawn of what promises to be an era of experimental and theoretical breakthroughs. Christopher Tully, an active participant in the work at the LHC, explains some of the most recent experiments in the field. But this book, which emerged fr

  5. Elementary Particles The first hundred years

    CERN Document Server

    Perkins, Donald Hill

    1997-01-01

    To mark the centenary of the discovery of that first elementary particle, the electron, some remarks and recollections from the early days of high energy physics, including the impact of early experiments and ideas on todayÕs research. Much of our progress in this field has been carefully anticipated and planned, but a surprising number of successes were the result of incredibly lucky breaks, where headway was made despite - or even because of - incorrect experimental results, crossed wires or simply asking the wrong question at the right time. We can be sure therefore that the next century - or perhaps even what remains of this one - will have unexpected surprises in store.

  6. Conservation Laws, Symmetries, and Elementary Particles

    Science.gov (United States)

    Hoekzema, Dick; Schooten, Gert; van den Berg, Ed; Lijnse, Piet

    2005-05-01

    The following student text on conservation laws, symmetries, and elementary particles was developed in a Dutch project for teaching modern physics to the top stream of the sixth year of secondary education (age 17-18). In a series of 35 lessons of 45-50 minutes each, students study particle-wave duality, the Heisenberg principle, probability models for properties of particles, the particle in a box, and applications, elementary particles, and astrophysics (http://www.phys.uu.nl/˜wwwpmn). In this paper we focus on particle physics and the key concepts of this chapter are: transformation, reaction equation, conservation laws, and symmetry. For recent literature regarding the teaching of symmetries and/or elementary particles, we refer to articles by Hill & Lederman, Pascolini & Pietroni,2 Kalmus,3 O'Connell,4 and Hanley.5

  7. On the Origin of Elementary Particle Masses

    Directory of Open Access Journals (Sweden)

    Hansson J.

    2014-04-01

    Full Text Available The oldest enigma in fundamental particle physics is: Where do the observed masses of elementary particles come from? Inspired by observation of the empirical particle mass spectrum we propose that the masses of elementary parti cles arise solely due to the self-interaction of the fields associated with a particle. We thus assume that the mass is proportional to the strength of the interaction of th e field with itself. A simple application of this idea to the fermions is seen to yield a mas s for the neutrino in line with constraints from direct experimental upper limits and correct order of magnitude predictions of mass separations between neutrinos, charge d leptons and quarks. The neutrino interacts only through the weak force, hence becom es light. The electron in- teracts also via electromagnetism and accordingly becomes heavier. The quarks also have strong interactions and become heavy. The photon is the only fundamental parti- cle to remain massless, as it is chargeless. Gluons gain mass comparable to quarks, or slightly larger due to a somewhat larger color charge. Inclu ding particles outside the standard model proper, gravitons are not exactly massless, but very light due to their very weak self-interaction. Some immediate and physically interesting consequences arise: i Gluons have an e ff ective range ∼ 1 fm, physically explaining why QCD has finite reach; ii Gravity has an effective range ∼ 100 Mpc coinciding with the largest known structures, the cosmic voids; iii Gravitational waves undergo dispersion even in vacuum, and have all five polarizations (not just the two of m = 0, which might explain why they have not yet been detected.

  8. Experimental Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Rosenfeld, Carl [Univ of South Carolina; Mishra, Sanjib R. [Univ of South Carolina; Petti, Roberto [Univ of South Carolina; Purohit, Milind V. [Univ of South Carolina

    2014-08-31

    The high energy physics group at the University of South Carolina, under the leadership of Profs. S.R. Mishra, R. Petti, M.V. Purohit, J.R. Wilson (co-PI's), and C. Rosenfeld (PI), engaged in studies in "Experimental Particle Physics." The group collaborated with similar groups at other universities and at national laboratories to conduct experimental studies of elementary particle properties. We utilized the particle accelerators at the Fermi National Accelerator Laboratory (Fermilab) in Illinois, the Stanford Linear Accelerator Center (SLAC) in California, and the European Center for Nuclear Research (CERN) in Switzerland. Mishra, Rosenfeld, and Petti worked predominantly on neutrino experiments. Experiments conducted in the last fifteen years that used cosmic rays and the core of the sun as a source of neutrinos showed conclusively that, contrary to the former conventional wisdom, the "flavor" of a neutrino is not immutable. A neutrino of flavor "e," "mu," or "tau," as determined from its provenance, may swap its identity with one of the other flavors -- in our jargon, they "oscillate." The oscillation phenomenon is extraordinarily difficult to study because neutrino interactions with our instruments are exceedingly rare -- they travel through the earth mostly unimpeded -- and because they must travel great distances before a substantial proportion have made the identity swap. Three of the experiments that we worked on, MINOS, NOvA, and LBNE utilize a beam of neutrinos from an accelerator at Fermilab to determine the parameters governing the oscillation. Two other experiments that we worked on, NOMAD and MIPP, provide measurements supportive of the oscillation experiments. Good measurements of the neutrino oscillation parameters may constitute a "low energy window" on related phenomena that are otherwise unobservable because they would occur only at energies way above the reach of conceivable accelerators. Purohit and Wilson participated in the Ba

  9. Current experiments in elementary particle physics, 1989

    CERN Document Server

    Lawrence Berkeley Nat. Laboratory. Berkeley; Armstrong, F E; Trippe, T G; Yost, G P; Oyanagi, Y; Dodder, D C; Ryabov, Yu G; Slabospitsky, S R; Frosch, R; Olin, A; Lehar, F; Klumov, I A; Ivanov, I I

    1989-01-01

    Contains more than 1,800 experiments in elementary particle physics from the Experience database. Search and browse by author; title; experiment number or prefix; institution; date approved, started or completed; accelerator or detector; polarization, reaction, final state or particle; or by papers produced. Maintained at SLAC for the Particle Data Group. Supplies the information for Current Experiments in Particle Physics (LBL-91). Print version updated every second year.

  10. Teaching Elementary Particle Physics: Part I

    Science.gov (United States)

    Hobson, Art

    2011-01-01

    I'll outline suggestions for teaching elementary particle physics, often called "high energy physics," in high school or introductory college courses for non-scientists or scientists. Some presentations of this topic simply list the various particles along with their properties, with little overarching structure. Such a laundry list approach is a…

  11. Elementary particle physics at the University of Florida. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    This report discusses the following topics: Task A: theoretical elementary particle physics; Task B: experimental elementary particle physics; Task C: axion project; Task G: experimental research in collider physics; and Task S: computer acquisition. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  12. Elementary particle physics in early physics education

    CERN Document Server

    Wiener, Gerfried

    2017-01-01

    Current physics education research is faced with the important question of how best to introduce elementary particle physics in the classroom early on. Therefore, a learning unit on the subatomic structure of matter was developed, which aims to introduce 12-year-olds to elementary particles and fundamental interactions. This unit was iteratively evaluated and developed by means of a design-based research project with grade-6 students. In addition, dedicated professional development programmes were set up to instruct high school teachers about the learning unit and enable them to investigate its didactical feasibility. Overall, the doctoral research project led to successful results and showed the topic of elementary particle physics to be a viable candidate for introducing modern physics in the classroom. Furthermore, thanks to the design-based research methodology, the respective findings have implications for both physics education and physics education research, which will be presented during the PhD defen...

  13. Elementary Particle Physics-Then and Now

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 3; Issue 7. Elementary Particle Physics-Then and Now. Avinash Khare. Reflections Volume 3 Issue 7 July 1998 pp 80-80. Fulltext. Click here to view fulltext PDF. Permanent link: http://www.ias.ac.in/article/fulltext/reso/003/07/0080-0080. Author Affiliations.

  14. Research in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    White, Andrew Paul [Univ. of Texas, Arlington, TX (United States); De, Kaushik [Univ. of Texas, Arlington, TX (United States); Brandt, Andrew [Univ. of Texas, Arlington, TX (United States); Yu, Jaehoon [Univ. of Texas, Arlington, TX (United States); Farbin, Amir [Univ. of Texas, Arlington, TX (United States)

    2015-02-02

    This report details the accomplishments and research results for the High Energy Physics Group at the University of Texas at Arlington at the Energy and Intensity Frontiers. For the Energy Frontier we have made fundamental contributions in the search for supersymmetric particles, proposed to explain the stabilization of the mass of the Higgs Boson – the agent giving mass to all known particles. We have also made major contributions to the search for additional Higgs Bosons and to the planning for future searches. This work has been carried out in the context of the ATLAS Experiment at CERN (European Nuclear Research Laboratory) and for which we have made major contributions to computing and data distribution and processing, and have worked to calibrate the detector and prepare upgraded electronics for the future. Our other contribution to the Energy Frontier has been to the International Linear Collider (ILC) project, potentially hosted by Japan, and to the Silicon Detector Concept (SiD) in particular. We have lead the development of the SiD Concept and have worked on a new form of precise energy measurement for particles from the high energy collisions of electrons and positrons at the ILC. For the Intensity Frontier, we have worked to develop the concept of Long Baseline Neutrino Experiment(s) (LBNE) at the Fermi National Accelerator Laboratory. Our contributions to detector development, neutrino beam studies, particle identification, software development will facilitate future studies of the oscillation of one type of neutrino into other type(s), establish the order of the neutrino masses, and, through an innovative new idea, allow us to create a beam of dark matter particles.

  15. Elementary particles, dark matter candidate and new extended standard model

    Science.gov (United States)

    Hwang, Jaekwang

    2017-01-01

    Elementary particle decays and reactions are discussed in terms of the three-dimensional quantized space model beyond the standard model. Three generations of the leptons and quarks correspond to the lepton charges. Three heavy leptons and three heavy quarks are introduced. And the bastons (new particles) are proposed as the possible candidate of the dark matters. Dark matter force, weak force and strong force are explained consistently. Possible rest masses of the new particles are, tentatively, proposed for the experimental searches. For more details, see the conference paper at https://www.researchgate.net/publication/308723916.

  16. Investigations in Elementary Particle Theory

    Energy Technology Data Exchange (ETDEWEB)

    Weiler, Thomas J. [Vanderbilt Univ., Nashville, TN (United States); Kephart, Thomas W. [Vanderbilt Univ., Nashville, TN (United States); Scherrer, Robert J. [Vanderbilt Univ., Nashville, TN (United States)

    2014-07-02

    The research interests of our three Co-PI’s complement each other very well. Kephart works mainly on models of particle unification in four or higher dimensions, on aspects of gravity such as inflation, black-holes, and the very early Universe, and on applications of knot theory and topology to various physical systems (including gluon dynamics). Scherrer works mainly on aspects of the intermediate-aged Universe, including dark matter and dark energy, and particle physics in the early Universe. Weiler works mainly on neutrino physics, dark matter signatures, and extreme particle-astrophysics in the late Universe, including origins of the highest-energy cosmic-rays and gamma-rays, and the future potential of neutrino astrophysics. Kephart and Weiler have lately devoted some research attention to the LHC and its reach for probing physics beyond the Standard Model. During the 3-year funding period, our grant supported one postdoc (Chiu Man Ho) and partially supported two students, Peter Denton and Lingjun Fu. Chiu Man collaborated with all three of the Co-PI’s during the 3-year funding period and published 16 refereed papers. Chiu Man has gone on to a postdoc with Steve Hsu at Michigan State University. Denton and Fu will both receive their PhDs during the 2014-15 academic year. The total number of our papers published in refereed journals by the three co-PIs during the period of this grant (2011-present) is 54. The total number of talks given by the group members during this time period, including seminars, colloquia, and conference presentations, is 47. Some details of the accomplishments of our DOE funded researchers during the grant period include Weiler being named a Simons Fellow in 2013. He presented an invited TEDx talk in 2012. His paper on closed timelike curves (2013) garnered a great deal of national publicity. Scherrer’s paper on the “little rip” (2011) fostered a new area of cosmological research, and the name “little rip” has now entered

  17. Current status of elementary particle physics

    CERN Document Server

    Okun, Lev Borisovich

    1998-01-01

    A brief review is given of the state-of-the-art in elementary particle physics based on the talk of the same title given on January 22, 1998, at the seminar marking the 90th anniversary of the birth of L.D. Landau. (The seminar was hosted by the P.L. Kapitza institute for physical problems in cooperation with the L.D. Landau institute of theoretical physics). (0 refs).

  18. Current experiments in elementary particle physics. Revision

    Energy Technology Data Exchange (ETDEWEB)

    Galic, H. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Armstrong, F.E. [Lawrence Berkeley Lab., CA (United States); von Przewoski, B. [Indiana Univ. Cyclotron Facility, Bloomington, IN (United States)] [and others

    1994-08-01

    This report contains summaries of 568 current and recent experiments in elementary particle physics. Experiments that finished taking data before 1988 are excluded. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, INS (Tokyo), ITEP (Moscow), IUCF (Bloomington), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several underground and underwater experiments. Instructions are given for remote searching of the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

  19. Research in elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Lai-Him; Haymaker, R.; Imlay, R.; McNeil, R.; Metcalf, W.; Svoboda, R.

    1992-01-01

    We describe theoretical work on effective action expansion on an effective low energy theory of hadrons and lattice gauge theories. The high energy experimental group at Louisiana State University has analyzed data on a neutrino oscillation experiment at LAMPF. The LSND neutrino experiment is preparing to take data in 1993. IMB data has been analyzed. Preparations for a beam test at KEK for IMB are in progress. Dumand is preparing to test one string of the detector early next summer. The ZEUS electron proton colliding beam experiment has started to take data. Early results have been reported.

  20. Research on elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, L.E.; O' Halloran, T.A.

    1992-05-01

    This report describes the activities of the University of Illinois Experimental High Energy Physics Group. The physicists in the University of Illinois High Energy Physics Group are engaged in a wide variety of experiments at current and future accelerator laboratories. These include: (1) The CDF experiment at the Fermilab Tevetron p{bar p} collider. (2) Design and developmental work for the SDC group at SSCL. (3) Experiments at the wide band photon beam at Fermilab. (4) The SLD experiment at SLAC and design studies for a {tau}-charm factor. (5) CP violation experiments at Fermilab. (6) The HiRes cosmic ray experiment at Dugway Proving Grounds, Utah. (7) Computational facilities. (8) Electronics systems development.

  1. Teaching Elementary Particle Physics, Part II

    Science.gov (United States)

    Hobson, Art

    2011-01-01

    In order to explain certain features of radioactive beta decay, Wolfgang Pauli suggested in 1930 that the nucleus emitted, in addition to a beta particle, another particle of an entirely new type. The hypothesized particle, dubbed the neutrino, would not be discovered experimentally for another 25 years. It's not easy to detect neutrinos, because…

  2. Compilation of data on elementary particles

    Energy Technology Data Exchange (ETDEWEB)

    Trippe, T.G.

    1984-09-01

    The most widely used data compilation in the field of elementary particle physics is the Review of Particle Properties. The origin, development and current state of this compilation are described with emphasis on the features which have contributed to its success: active involvement of particle physicists; critical evaluation and review of the data; completeness of coverage; regular distribution of reliable summaries including a pocket edition; heavy involvement of expert consultants; and international collaboration. The current state of the Review and new developments such as providing interactive access to the Review's database are described. Problems and solutions related to maintaining a strong and supportive relationship between compilation groups and the researchers who produce and use the data are discussed.

  3. Elementary particles and emergent phase space

    CERN Document Server

    Zenczykowski, Piotr

    2014-01-01

    The Standard Model of elementary particles, although very successful, contains various elements that are put in by hand. Understanding their origin requires going beyond the model and searching for ""new physics"". The present book elaborates on one particular proposal concerning such physics. While the original conception is 50 years old, it has not lost its appeal over time. Its basic idea is that space - an arena of events treated in the Standard Model as a classical background - is a concept which emerges from a strictly discrete quantum layer in the limit of large quantum numbers. This bo

  4. (Research in elementary particles and interactions). [1992

    Energy Technology Data Exchange (ETDEWEB)

    Adair, R.; Sandweiss, J.; Schmidt, M.

    1992-05-01

    Research of the Yale University groups in the areas of elementary particles and their interactions are outlined. Work on the following topics is reported: development of CDF trigger system; SSC detector development; study of heavy flavors at TPL; search for composite objects produced in relativistic heavy-ion collisions; high-energy polarized lepton-nucleon scattering; rare K{sup +} decays; unpolarized high-energy muon scattering; muon anomalous magnetic moment; theoretical high-energy physics including gauge theories, symmetry breaking, string theory, and gravitation theory; study of e{sup +}e{sup {minus}} interactions with the SLD detector at SLAC; and the production and decay of particles containing charm and beauty quarks.

  5. Facts and mysteries in elementary particle physics

    CERN Document Server

    Veltman, Martinus J G

    2018-01-01

    This book provides a comprehensive overview of modern particle physics accessible to anyone with a true passion for wanting to know how the universe works. We are introduced to the known particles of the world we live in. An elegant explanation of quantum mechanics and relativity paves the way for an understanding of the laws that govern particle physics. These laws are put into action in the world of accelerators, colliders and detectors found at institutions such as CERN and Fermilab that are in the forefront of technical innovation. Real world and theory meet using Feynman diagrams to solve the problems of infinities and deduce the need for the Higgs boson. Facts and Mysteries in Elementary Particle Physics offers an incredible insight from an eyewitness and participant in some of the greatest discoveries in 20th century science. From Einstein's theory of relativity to the spectacular discovery of the Higgs particle, this book will fascinate and educate anyone interested in the world of quarks, leptons an...

  6. Elementary Particle Spectroscopy in Regular Solid Rewrite

    Science.gov (United States)

    Trell, Erik

    2008-10-01

    The Nilpotent Universal Computer Rewrite System (NUCRS) has operationalized the radical ontological dilemma of Nothing at All versus Anything at All down to the ground recursive syntax and principal mathematical realisation of this categorical dichotomy as such and so governing all its sui generis modalities, leading to fulfilment of their individual terms and compass when the respective choice sequence operations are brought to closure. Focussing on the general grammar, NUCRS by pure logic and its algebraic notations hence bootstraps Quantum Mechanics, aware that it "is the likely keystone of a fundamental computational foundation" also for e.g. physics, molecular biology and neuroscience. The present work deals with classical geometry where morphology is the modality, and ventures that the ancient regular solids are its specific rewrite system, in effect extensively anticipating the detailed elementary particle spectroscopy, and further on to essential structures at large both over the inorganic and organic realms. The geodetic antipode to Nothing is extension, with natural eigenvector the endless straight line which when deployed according to the NUCRS as well as Plotelemeian topographic prescriptions forms a real three-dimensional eigenspace with cubical eigenelements where observed quark-skewed quantum-chromodynamical particle events self-generate as an Aristotelean phase transition between the straight and round extremes of absolute endlessness under the symmetry- and gauge-preserving, canonical coset decomposition SO(3)×O(5) of Lie algebra SU(3). The cubical eigen-space and eigen-elements are the parental state and frame, and the other solids are a range of transition matrix elements and portions adapting to the spherical root vector symmetries and so reproducibly reproducing the elementary particle spectroscopy, including a modular, truncated octahedron nano-composition of the Electron which piecemeal enter into molecular structures or compressed to each

  7. Current experiments in elementary particle physics. Revision 1-85

    Energy Technology Data Exchange (ETDEWEB)

    Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.; Trippe, T.G.; Yost, G.P.; Oyanagi, Y.; Dodder, D.C.; Grudtsin, S.N.; Ryabov, Yu.G.; Frosch, R.

    1985-01-01

    This report contains summaries of 551 approved experiments in elementary particle physics (experiments that finished taking data before 1 January 1980 are excluded). Included are experiments at Brookhaven, CERN, CESR, DESY, Fermilab, Moscow Institute of Theoretical and Experimental Physics, Tokyo Institute of Nuclear Studies, KEK, LAMPF, Leningrad Nuclear Physics Institute, Saclay, Serpukhov, SIN, SLAC, and TRIUMF, and also experiments on proton decay. Properties of the fixed-target beams at most of the laboratories are summarized. Instructions are given for searching online the computer database (maintained under the SLAC/SPIRES system) that contains the summaries.

  8. Vanishing cosmological constant in elementary particles theory

    Energy Technology Data Exchange (ETDEWEB)

    Pisano, F. [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Tonasse, M.D. [Universidade do Estado, Rio de Janeiro, RJ (Brazil). Inst. de Fisica

    1997-01-01

    The quest of a vanishing cosmological constant is considered in the simplest anomaly-free chiral gauge extension of the electroweak standard model where the new physics is limited to a well defined additional flavordynamics above the Fermi scale, namely up to a few TeVs by matching the gauge coupling constants at the electroweak scale, and with an extended Higgs structure. In contrast to the electroweak standard model, it is shown how the extended scalar sector of the theory allows a vanishing or a very small cosmological constant. the details of the cancellation mechanism are presented. At accessible energies the theory is indistinguishable from the standard model of elementary particles and it is in agreement with all existing data. (author). 32 refs. 32 refs.

  9. Theoretical Advanced Study Institute in Elementary Particle Physics

    CERN Document Server

    2006-01-01

    This book contains write-ups of lectures from a summer school for advanced graduate students in elementary particle physics. In the first lecture, Scott Willenbrock gives an overview of the standard model of particle physics. This is followed by reviews of specific areas of standard model physics: precision electroweak analysis by James Wells, quantum chromodynamics and jets by George Sterman, and heavy quark effective field by Matthias Neubert. Developments in neutrino physics are discussed by André de Gouvea and the theory behind the Higgs boson is addressed by Laura Reina. Collider phenomenology from both experimental and theoretical perspectives are highlighted by Heidi Schellman and Tao Han. A brief survey of dynamical electroweak symmetry breaking is provided by R Sekhar Chivukula and Elizabeth H Simmons. Martin Schmaltz covers the recent proposals for “little” Higgs theories. Markus Luty describes what is needed to make supersymmetric theories realistic by breaking supersymmetry. There is an entir...

  10. An introduction to elementary particle phenomenology

    CERN Document Server

    Ratcliffe, Philip G

    2014-01-01

    This book deals with the development of particle physics, in particular through the exacting and all-important interplay between theory and experiment, an area that has now become known as phenomenology. Particle physics phenomenology provides the connection between the mathematical models created by theoretical physicists and the experimentalists who explore the building blocks of matter and the forces that operate between them. Assuming no more background knowledge than the basics of quantum mechanics, relativistic mechanics and nuclear physics, the author presents a solid and clear motivation for the developments witnessed by the particle physics community at both high and low energies over that last 50 or 60 years. In particular, the role of symmetries and their violation is central to many of the discussions. Including exercises and many references to original experimental and theoretical papers, as well as other useful sources, it will be essential reading for all students and researchers in ...

  11. Quantum field theory and the internal states of elementary particles

    CSIR Research Space (South Africa)

    Greben, JM

    2011-01-01

    Full Text Available A new application of quantum field theory is developed that gives a description of the internal dynamics of dressed elementary particles and predicts their masses. The fermionic and bosonic quantum fields are treated as interdependent fields...

  12. Physics through the 1990s: Elementary-particle physics

    Science.gov (United States)

    1986-01-01

    The volume begins with a non-mathematical discussion of the motivation behind, and basic ideas of, elementary-particle physics theory and experiment. The progress over the past two decades with the quark model and unification of the electromagnetic and weak interactions is reviewed. Existing theoretical problems in the field, such as the origin of mass and the unification of the fundamental forces, are detailed, along with experimental programs to test the new theories. Accelerators, instrumentation, and detectors are described for both current and future facilities. Interactions with other areas of both theoretical and applied physics are presented. The sociology of the field is examined regarding the education of graduate students, the organization necessary in large-scale experiments, and the decision-making process involved in high-cost experiments. Finally, conclusions and recommendations for maintaining US excellence in theory and experiment are given. Appendices list both current and planned accelerators, and present statistical data on the US elementary-particle physics program. A glossary is included.

  13. The origin of mass elementary particles and fundamental symmetries

    CERN Document Server

    Iliopoulos, John

    2017-01-01

    The discovery of a new elementary particle at the Large Hadron Collider at CERN in 2012 made headlines in world media. Since we already know of a large number of elementary particles, why did this latest discovery generate so much excitement? This small book reveals that this particle provides the key to understanding one of the most extraordinary phenomena which occurred in the early Universe. It introduces the mechanism that made possible, within tiny fractions of a second after the Big Bang, the generation of massive particles. The Origin of Mass is a guided tour of cosmic evolution, from the Big Bang to the elementary particles we study in our accelerators today. The guiding principle of this book is a concept of symmetry which, in a profound and fascinating way, seems to determine the structure of the Universe.

  14. Current experiments in elementary particle physics, 1976-87

    CERN Document Server

    Lawrence Berkeley Nat. Laboratory. Berkeley

    Contains more than 1,800 experiments in elementary particle physics from the Experience database. Search and browse by author; title; experiment number or prefix; institution; date approved, started or completed; accelerator or detector; polarization, reaction, final state or particle; or by papers produced. Maintained at SLAC for the Particle Data Group. Supplies the information for Current Experiments in Particle Physics (LBL-91). Print version updated every second year.

  15. Final Report May 1, 2012 to May 31, 2015: "Theoretical Studies in Elementary Particle Physics"

    Energy Technology Data Exchange (ETDEWEB)

    Collins, John C. [Pennsylvania State Univ., State College, PA (United States); Roiban, Radu [Pennsylvania State Univ., State College, PA (United States)

    2015-08-19

    This final report summarizes work at Penn State University from May 1, 2012 to May 31, 2015. The work was in theoretical elementary particle physics. Many new results in perturbative QCD, in string theory, and in related areas were obtained, with a substantial impact on the experimental program.

  16. PHYSICS OF OUR DAYS: Old and new exotic phenomena in the world of elementary particles

    Science.gov (United States)

    Mukhin, Konstantin N.; Tikhonov, Viktor N.

    2001-11-01

    This paper traces the history of elementary particle discoveries, beginning with the muon and ending with the t-quark and the τ-neutrino. Experimental work and basic theoretical concepts are reviewed. Recent neutrino oscillation research and attempts at finding exotic particles and creating artificial quark-gluon plasma are described. The physical beauty of experiments is emphasized and the elegance of both theoretical predictions and of the interpretation of discoveries is revealed. Possible research directions for the near future are discussed.

  17. Essay: the tau lepton and thirty years of changes in elementary particle physics research.

    Science.gov (United States)

    Perl, M L

    2008-02-22

    Starting with the 1975 discovery of the tau lepton, I look back on the last three decades of change in the substance and style of experimental and theoretical research in elementary particle physics. I recount the major accomplishments of those decades and predict a bright future for particle physics in the next two decades. Turning to three problems, I lament the change in theoretical style and taste, I discuss the growth in the complexity, size, and cost of particle physics experiments, and I conclude with a pessimistic comment on the size of particle physics collaborations.

  18. Elementary Particle Interactions with CMS at LHC

    Energy Technology Data Exchange (ETDEWEB)

    Spanier, Stefan [Univ. of Tennessee, Knoxville, TN (United States)

    2016-07-31

    The High Energy Particle Physics group of the University of Tennessee participates in the search for new particles and forces in proton-proton collisions at the LHC with the Compact Muon Solenoid experiment. Since the discovery of the Higgs boson in 2012, the search has intensified to find new generations of particles beyond the standard model using the higher collision energies and ever increasing luminosity, either directly or via deviations from standard model predictions such as the Higgs boson decays. As part of this effort, the UTK group has expanded the search for new particles in four-muon final states, and in final states with jets, has successfully helped and continues to help to implement and operate an instrument for improved measurements of the luminosity needed for all data analyses, and has continued to conduct research of new technologies for charged particle tracking at a high-luminosity LHC.

  19. A Search for Free Fractional Electric Charge Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied--about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  20. A Search for Free Fractional Electric Charge Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    Halyo, Valerie

    2000-12-04

    A direct search was carried out in bulk matter for free fractional electric charge elementary particles using the largest mass single sample ever studied| about 17.4 mg of silicone oil. The search used an improved and highly automated Millikan oil drop technique. No evidence for fractional charge particles was found. The concentration of particles with fractional charge more than 0.16 e (e being the magnitude of the electron charge) from the nearest integer charge is less than 4.71 x 10{sup -22} particles per nucleon with 95% confidence.

  1. Quantum Optics, Diffraction Theory, and Elementary Particle Physics

    CERN Multimedia

    CERN. Geneva

    2009-01-01

    Physical optics has expanded greatly in recent years. Though it remains part of the ancestry of elementary particle physics, there are once again lessons to be learned from it. I shall discuss several of these, including some that have emerged at CERN and Brookhaven.

  2. The Birth of Elementary-Particle Physics.

    Science.gov (United States)

    Brown, Laurie M.; Hoddeson, Lillian

    1982-01-01

    Traces the origin and development of particle physics, concentrating on the roles of cosmic rays and theory. Includes charts highlighting significant events in the development of cosmic-ray physics and quantum field theory. (SK)

  3. Elementary Particles in a New Quantum Scheme

    OpenAIRE

    Sannikov, S. S.; Stanislavsky, A. A.; Cabbolet, M. J. T. F.

    1999-01-01

    Proceeding from the main principles of the non-unitary quantum theory of relativistic bi-Hamiltonian systems, a system of Lagrangian fields characterized by a certain dispersion law (mass spectrum of particles), interactions between them and their coupling constants are constructed. In this article the mass spectrum formula for ``bare'' fundamental hadrons is introduced, and an a priori normalization of particle fields is found as well. Numerical values of some parameters of the present theor...

  4. The Mathematical Structure of Elementary Particles. II.

    Science.gov (United States)

    1985-05-01

    Physical Mathematics) *Instituto de Matematica Pura e Aplicada , Estrada Dona Castorina 110, 22460 Rio de Janeiro, Brazil Sponsored by the United States Army...symmetries of these particles. j The considerations that lead to this result are as follows. *Instituto de Matematica Pura e Aplicada , Estrada Dona Castorina

  5. Elementary particle physics at the University of Florida. Annual report

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.D.; Ramond, P.M.; Sikivie, P. [and others

    1995-12-01

    This is the annual progress report of the University of Florida`s elementary particle physics group. The theoretical high energy physics group`s research covers a broad range of topics, including both theory and phenomenology. Present work of the experimental high energy physics group is directed toward the CLEO detector, with some effort going to B physics at Fermilab. The Axion Search project is participating in the operation of a large-scale axion detector at Lawrence Livermore National Laboratory, with the University of Florida taking responsibility for this experiment`s high-resolution spectrometer`s assembly, programming, and installation, and planning to take shifts during operation of the detector in FY96. The report also includes a continuation of the University`s three-year proposal to the United States Department of Energy to upgrade the University`s high-energy physics computing equipment and to continue student support, system manager/programmer support, and maintenance. Report includes lists of presentations and publications by members of the group.

  6. Properties and Interactions of Elementary Particles

    Energy Technology Data Exchange (ETDEWEB)

    Amidei, Dante; Campbell, Myron; Huterer, Dragan; Kane, Gordon; Liu, James; Qian, Jianming; Tarle, Gregory; Zhou, Bing

    2012-08-25

    We summarize the accomplishments over the last renewal period in a broad program of research in experimental and theoretical High Energy Physics, conducted at the University of Michigan, and supported by the U.S. Department of Energy.

  7. Charting the Course for Elementary Particle Physics

    Science.gov (United States)

    Richter, B.

    2007-02-16

    "It was the best of times; it was the worst of times" is the way Dickens begins the Tale of Two Cities. The line is appropriate to our time in particle physics. It is the best of times because we are in the midst of a revolution in understanding, the third to occur during my career. It is the worst of times because accelerator facilities are shutting down before new ones are opening, restricting the opportunity for experiments, and because of great uncertainty about future funding. My task today is to give you a view of the most important opportunities for our field under a scenario that is constrained by a tight budget. It is a time when we cannot afford the merely good, but must give first priority to the really important. The defining theme of particle physics is to learn what the universe is made of and how it all works. This definition spans the full range of size from the largest things to the smallest things. This particle physics revolution has its origins in experiments that look at both.

  8. Elementary Particle Physics in Belgium Exhibition

    CERN Multimedia

    2000-01-01

    The experimental activities of the Belgian Universities and Institutes are performed within the framework of large international collaborations. Moreover, the universities whose name is colored in light blue with * on the map of Belgium also take part into theoretical work. (All these activities are mainly supported by the FNRS-FWO research foundations.)

  9. Elementary Particle Physics at Baylor (Final Report)

    Energy Technology Data Exchange (ETDEWEB)

    Dittmann, J.R.

    2012-08-25

    This report summarizes the activities of the Baylor University Experimental High Energy Physics (HEP) group on the Collider Detector at Fermilab (CDF) experiment from August 15, 2005 to May 31, 2012. Led by the Principal Investigator (Dr. Jay R. Dittmann), the Baylor HEP group has actively pursued a variety of cutting-edge measurements from proton-antiproton collisions at the energy frontier.

  10. Elementary particles in the early Universe

    CERN Document Server

    Gromov, Nikolai A

    2015-01-01

    The low energy limit of Electroweak Model is obtained from first principles of gauge theory. The very weak neutrino-matter interaction especially at low energies is explained by zero tending contraction parameter, which depend on the neutrino energy. The high-energy limit of Standard Model is generated by the contractions of gauge groups. Contraction parameters of gauge group $SU(2)$ of Electroweak Model and gauge group $SU(3)$ of Quantum Chromodynamics are taken identical and tending to zero when energy increase. At the infinite energy limit all particles lose masses, all quarks have only one color. Electroweak interactions become long-range and are mediated by the neutral currents. The limit model represents the development of Standard Model in the early Universe from the Big Bang up to the end of several milliseconds.

  11. Current experiments in elementary-particle physics - March 1983

    Energy Technology Data Exchange (ETDEWEB)

    Wohl, C.G.; Armstrong, F.E.; Rittenberg, A.

    1983-03-01

    Microfiche are included which contain summaries of 479 experiments in elementary particle physics. Experiments are included at the following laboratories: Brookhaven (BNL); CERN; CESR; DESY; Fermilab (FNAL); Institute for Nuclear Studies (INS); KEK; LAMPF; Serpukhov (SERP); SIN; SLAC; and TRIUMF. Also, summaries of proton decay experiments are included. A list of experiments and titles is included; and a beam-target-momentum index and a spokesperson index are given. Properties of beams at the facilities are tabulated. (WHK)

  12. Thirty Unsolved Problems in the Physics of Elementary Particles

    Directory of Open Access Journals (Sweden)

    Christianto V.

    2007-10-01

    Full Text Available Unlike what some physicists and graduate students used to think, that physics science has come to the point that the only improvement needed is merely like adding more numbers in decimal place for the masses of elementary particles or gravitational constant, there is a number of unsolved problems in this field that may require that the whole theory shall be reassessed. In the present article we discuss thirty of those unsolved problems and their likely implications. In the first section we will discuss some well-known problems in cosmology and particle physics, and then other unsolved problems will be discussed in next section.

  13. FOREWORD: Corfu Summer Institute on Elementary Particle Physics (CORFU2005)

    Science.gov (United States)

    Anagnostopoulos, Konstantinos; Antoniadis, Ignatios; Fanourakis, George; Kehagias, Alexandros; Savoy-Navarro, Aurore; Wess, Julius; Zoupanos, George

    2006-12-01

    These are the Proceedings of the Corfu Summer Institute on Elementary Particle Physics (CORFU2005) (http://corfu2005.physics.uoi.gr), which took place in Corfu, Greece from 4 - 26 September 2005. The Corfu Summer Institute has a very long, interesting and successful history, some elements of which can be found in http://www.corfu-summer-institute.gr. In short, the Corfu Meeting started as a Summer School on Elementary Particle Physics (EPP) mostly for Greek graduate students in 1982 and has developed into a leading international Summer Institute in the field of EPP, both experimental and theoretical, providing in addition a very rich outreach programme to teachers and school students. The CORFU2005 Summer Institute on EPP, although based on the general format that has been developed and established in the Corfu Meetings during previous years, is characterized by the fact that it was a full realization of a new idea, which started experimentally in the previous two Corfu Meetings. The successful new ingredient was that three European Marie Curie Research Training Networks decided to hold their Workshops in Corfu during September 2005 and they managed to coordinate the educational part of their meetings to a huge Summer School called `The 8th Hellenic School on Elementary Particle Physics' (4 - 11 September). The European Networks which joined forces to materialize this project and the corresponding dates of their own Workshops are: The Third Generation as a Probe for New Physics: Experimental and Technological Approach (4 - 11 September) The Quest for Unification Theory Confronts Experiment (11 - 18 September) Constituents Fundamental Forces and Symmetries of the Universe (20 - 26 September) To these Workshops has been added a Satellite one called `Noncommutative Geometry in Field and String Theory', and some extra speakers have been invited to complement the full programme of CORFU2005, some of whom have integrated into the Workshop's programme. The result was

  14. On the ontology of the elementary particles. A philosophical analysis of the actual elementary-particle physics; Zur Ontologie der Elementarteilchen. Eine philosophische Analyse der aktuellen Elementarteilchenphysik

    Energy Technology Data Exchange (ETDEWEB)

    Brueckner, Thomas Christian

    2015-07-01

    After a description of the standard model of elementary-particle physics the author describes structuralistic reconstructions. Then the problem of the theoretical terms is discussed. Therafter the reconstruction of the standard-model elementary particles is described. Finally the ontology of leptons, quarks and both free and in atoms bound protons is considered.

  15. Research in theoretical and elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Mitselmakher, G. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-01

    In 1995 the University of Florida started a major expansion of the High Energy Experimental Physics group (HEE) with the goal of adding four new faculty level positions to the group in two years. This proposal covers the second year of operation of the new group and gives a projection of the planned research program for the next five years, when the group expects their activities to be broader and well defined. The expansion of the HEE group started in the Fall of 1995 when Guenakh Mitselmakher was hired from Fermilab as a Full Professor. A search was then performed for two junior faculty positions. The first being a Research Scientist/Scholar position which is supported for 9 months by the University on a faculty line at the same level as Assistant Professor but without the teaching duties. The second position is that of an Assistant Professor. The search has been successfully completed and Jacobo Konigsberg from Harvard University has accepted the position of Research Scientist and Andrey Korytov from MIT has accepted the position of Assistant Professor. They will join the group in August 1996. The physics program for the new group is focused on hadron collider physics. G. Mitselmakher has been leading the CMS endcap muon project since 1994. A Korytov is the coordinator of the endcap muon chamber effort for CMS and a member of the CDF collaboration and J. Konigsberg is a member of CDF where he has participated in various physics analyses and has been coordinator of the gas calorimetry group. The group at the U. of Florida has recently been accepted as an official collaborating institution on CDF. They have been assigned the responsibility of determining the collider beam luminosity at CDF and they will also be an active participant in the design and operation of the muon detectors for the intermediate rapidity region. In addition they expect to continue their strong participation in the present and future physics analysis of the CDF data.

  16. Knots on a Torus: A Model of the Elementary Particles

    Directory of Open Access Journals (Sweden)

    Jack S. Avrin

    2012-02-01

    Full Text Available Two knots; just two rudimentary knots, the unknot and the trefoil. That’s all we need to build a model of the elementary particles of physics, one with fermions and bosons, hadrons and leptons, interactions weak and strong and the attributes of spin, isospin, mass, charge, CPT invariance and more. There are no quarks to provide fractional charge, no gluons to sequester them within nucleons and no “colors” to avoid violating Pauli’s principle. Nor do we require the importation of an enigmatic Higgs boson to confer mass upon the particles of our world. All the requisite attributes emerge simply (and relativistically invariant as a result of particle conformation and occupation in and of spacetime itself, a spacetime endowed with the imprimature of general relativity. Also emerging are some novel tools for systemizing the particle taxonomy as governed by the gauge group SU(2 and the details of particle degeneracy as well as connections to Hopf algebra, Dirac theory, string theory, topological quantum field theory and dark matter. One exception: it is found necessary to invoke the munificent geometry of the icosahedron in order to provide, as per the group “flavor” SU(3, a scaffold upon which to organize the well-known three generations—no more, no less—of the particle family tree.

  17. [Research in elementary particles and interactions]. Technical progress report

    Energy Technology Data Exchange (ETDEWEB)

    Adair, R.; Sandweiss, J.; Schmidt, M.

    1992-05-01

    Research of the Yale University groups in the areas of elementary particles and their interactions are outlined. Work on the following topics is reported: development of CDF trigger system; SSC detector development; study of heavy flavors at TPL; search for composite objects produced in relativistic heavy-ion collisions; high-energy polarized lepton-nucleon scattering; rare K{sup +} decays; unpolarized high-energy muon scattering; muon anomalous magnetic moment; theoretical high-energy physics including gauge theories, symmetry breaking, string theory, and gravitation theory; study of e{sup +}e{sup {minus}} interactions with the SLD detector at SLAC; and the production and decay of particles containing charm and beauty quarks.

  18. The Logarithmic Potential and an Exponential Mass Function for Elementary Particles

    Directory of Open Access Journals (Sweden)

    Paasch K.

    2009-01-01

    Full Text Available The assumption that elementary particles with nonzero rest mass consist of relativistic constituents moving with constant energy, pc, results in a logarithmic potential and exponential expression for particle masses. This approach is put to a test by assigning each elementary particles mass a position on a logarithmic spiral. Particles then accumulate on straight lines. It is discussed if this might be an indication for exponential mass quantization.

  19. Research in elementary particle physics. [Ohio State Univ. , Columbus

    Energy Technology Data Exchange (ETDEWEB)

    1992-01-01

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.

  20. Internal Structure of Elementary Particle and Possible Deterministic Mechanism of Biological Evolution

    Science.gov (United States)

    Melkikh, Alexei V.

    2004-03-01

    The possibility of a complicated internal structure of an elementary particle was analyzed. In this case a particle may represent a quantum computer with many degrees of freedom. It was shown that the probability of new species formation by means of random mutations is negligibly small. Deterministic model of evolution is considered. According to this model DNA nucleotides can change their state under the control of elementary particle internal degrees of freedom.

  1. Experimental entanglement of four particles

    Science.gov (United States)

    Sackett; Kielpinski; King; Langer; Meyer; Myatt; Rowe; Turchette; Itano; Wineland; Monroe

    2000-03-16

    Quantum mechanics allows for many-particle wavefunctions that cannot be factorized into a product of single-particle wavefunctions, even when the constituent particles are entirely distinct. Such 'entangled' states explicitly demonstrate the non-local character of quantum theory, having potential applications in high-precision spectroscopy, quantum communication, cryptography and computation. In general, the more particles that can be entangled, the more clearly nonclassical effects are exhibited--and the more useful the states are for quantum applications. Here we implement a recently proposed entanglement technique to generate entangled states of two and four trapped ions. Coupling between the ions is provided through their collective motional degrees of freedom, but actual motional excitation is minimized. Entanglement is achieved using a single laser pulse, and the method can in principle be applied to any number of ions.

  2. Experimental techniques in nuclear and particle physics

    CERN Document Server

    Tavernier, Stefaan

    2009-01-01

    The book is based on a course in nuclear and particle physics that the author has taught over many years to physics students, students in nuclear engineering and students in biomedical engineering. It provides the basic understanding that any student or researcher using such instruments and techniques should have about the subject. After an introduction to the structure of matter at the subatomic scale, it covers the experimental aspects of nuclear and particle physics. Ideally complementing a theoretically-oriented textbook on nuclear physics and/or particle physics, it introduces the reader to the different techniques used in nuclear and particle physics to accelerate particles and to measurement techniques (detectors) in nuclear and particle physics. The main subjects treated are: interactions of subatomic particles in matter; particle accelerators; basics of different types of detectors; and nuclear electronics. The book will be of interest to undergraduates, graduates and researchers in both particle and...

  3. Chemistry at elementary schools: particles or also atoms – that's the ...

    African Journals Online (AJOL)

    At elementary school level, the description of substances and their changes is preferred by most guidelines of education. If the elementary school includes fifth and sixth graders like in Africa, it seems to be possible to introduce the idea of the Particle Model of Matter to reflect changes of states, dissolving and diffusing ...

  4. Elementary Particle Physics and High Energy Phenomena: Final Report for FY2010-13

    Energy Technology Data Exchange (ETDEWEB)

    Cumalat, John P.; de Alwis, Senarath P.; DeGrand, Thomas A.; DeWolfe, Oliver; Ford, William T.; Hasenfratz, Anna; Mahanthappa, K. T.; Marino, Alysia D.; Nauenberg, Uriel; Smith, James G.; Stenson, Kevin; Wagner, Stephen R.; Zimmerman, Eric D.

    2013-06-27

    The work under this grant consists of experimental, theoretical, and phenomenological research on the fundamental properties of high energy subnuclear particles. The work is conducted at the University of Colorado, the European Organization for Nuclear Research (CERN), the Japan Proton Accelerator Research Complex (J-PARC), Fermi National Accelerator Laboratory (FNAL), SLAC National Accelerator Laboratory (SLAC), Los Alamos National Laboratory (LANL), and other facilities, employing neutrino-beam experiments, test beams of various particles, and proton-proton collider experiments. It emphasizes mass generation and symmetry-breaking, neutrino oscillations, bottom particle production and decay, detector development, supergravity, supersymmetry, superstrings, quantum chromodynamics, nonequilibrium statistical mechanics, cosmology, phase transitions, lattice gauge theory, and anomaly-free theories. The goals are to improve our understanding of the basic building blocks of matter and their interactions. Data from the Large Hadron Collider at CERN have revealed new interactions responsible for particle mass, and perhaps will lead to a more unified picture of the forces among elementary material constituents. To this end our research includes searches for manifestations of theories such as supersymmetry and new gauge bosons, as well as the production and decay of heavy-flavored quarks. Our current work at J-PARC, and future work at new facilities currently under conceptual design, investigate the specifics of how the neutrinos change flavor. The research is integrated with the training of students at all university levels, benefiting both the manpower and intellectual base for future technologies.

  5. 100 years of Elementary Particles [Beam Line, vol. 27, issue 1, Spring 1997

    Science.gov (United States)

    Pais, Abraham; Weinberg, Steven; Quigg, Chris; Riordan, Michael; Panofsky, Wolfgang K. H.; Trimble, Virginia

    1997-04-01

    This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.

  6. On the number of elementary particles in a resolution dependent fractal spacetime

    Energy Technology Data Exchange (ETDEWEB)

    He Jihuan [College of Science, Donghua University, 1882 Yan-an Xilu Road, Shanghai 200051 (China)]. E-mail: jhhe@dhu.edu.cn

    2007-06-15

    We reconsider the fundamental question regarding the number of elementary particles in a minimally extended standard model. The main conclusion is that since the dimension of E-infinity spacetime is resolution dependent, then the number of elementary particles is also resolution dependent. For D = 10 of superstrings, D = 11 of M theory and D = 12 of F theory one finds N(SM) equal to (6)(10) = 60 (6)(11) = 66 and (6)(12) = 72 particles, respectively. This is in perfect agreement with prediction made previously by Mohamed Saladin El-Naschie and Marek-Crnjac.

  7. 100 years of elementary particles [Beam Line, vol. 27, issue 1, Spring 1997

    Energy Technology Data Exchange (ETDEWEB)

    Pais, Abraham; Weinberg, Steven; Quigg, Chris; Riordan, Michael; Panofsky, Wolfgang K.H.; Trimble, Virginia

    1997-04-01

    This issue of Beam Line commemorates the 100th anniversary of the April 30, 1897 report of the discovery of the electron by J.J. Thomson and the ensuing discovery of other subatomic particles. In the first three articles, theorists Abraham Pais, Steven Weinberg, and Chris Quigg provide their perspectives on the discoveries of elementary particles as well as the implications and future directions resulting from these discoveries. In the following three articles, Michael Riordan, Wolfgang Panofsky, and Virginia Trimble apply our knowledge about elementary particles to high-energy research, electronics technology, and understanding the origin and evolution of our Universe.

  8. Modern elementary particle physics explaining and extending the standard model

    CERN Document Server

    Kane, Gordon

    2017-01-01

    This book is written for students and scientists wanting to learn about the Standard Model of particle physics. Only an introductory course knowledge about quantum theory is needed. The text provides a pedagogical description of the theory, and incorporates the recent Higgs boson and top quark discoveries. With its clear and engaging style, this new edition retains its essential simplicity. Long and detailed calculations are replaced by simple approximate ones. It includes introductions to accelerators, colliders, and detectors, and several main experimental tests of the Standard Model are explained. Descriptions of some well-motivated extensions of the Standard Model prepare the reader for new developments. It emphasizes the concepts of gauge theories and Higgs physics, electroweak unification and symmetry breaking, and how force strengths vary with energy, providing a solid foundation for those working in the field, and for those who simply want to learn about the Standard Model.

  9. Experimental physics 4. Nuclear, particle and astrophysics. 5. ed.; Experimentalphysik 4. Kern-, Teilchen- und Astrophysik

    Energy Technology Data Exchange (ETDEWEB)

    Demtroeder, Wolfgang

    2017-09-01

    The following topics are dealt with: Structure of atomic nuclei, unstable nuclei and radioactivity, experimental techniques in nuclear and high-energy physics, nuclear forces and nuclear models, nuclear reactions, physics of elementary particles, applications of nuclear and high-energy physics, foundations of experimental astronomy and astrophysics, our solar system, birth, life, and death of stars, the development and present structure of the universe. (HSI)

  10. Research program in elementary-particle theory, 1983. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sudarshan, E C.G.; Ne& #x27; eman, Y

    1983-08-01

    Progress is reviewed on the following topics: physics of ultra high energies and cosmology; phenomenology of particle physics; quantum field theory, supersymmetry and models of particles; and geometric formulations and algebraic models. Recent DOE reports resulting from the contract are listed. (WHK)

  11. CERN and the Hunt for Elementary Particles and Forces

    CERN Document Server

    AUTHOR|(CDS)2051276

    2008-01-01

    CERN is the European Laboratory for Particle Physics, the world's largest particle physics research centre. Founded in 1954, the Laboratory was one of Europe's first joint ventures and has become a premier example of international collaboration. CERN's subject of study is pure science and is concentrated on exploring the Universe's most fundamental questions, such as What is it made of? and How did it come to be the way it is? The Laboratory's tools, the particle accelerators and particle detectors, are amongst the world's largest and most complex scientific instruments. The Laboratory's primary aims will be presented and a look at past achievements and present endeavours, particularly the Large Hadron Collider (LHC), will be reviewed. A brief look into the future will also be given.

  12. Experimental Basis for IED Particle Model

    Science.gov (United States)

    Zheng-Johansson, J.

    2009-05-01

    The internally electrodynamic (IED) particle model is built on three experimental facts: a) electric charges present in all matter particles, b) an accelerated charge generates electromagnetic (EM) waves by Maxwell's equations and Planck energy equation, and c) source motion gives Doppler effect. A set of well-kwon basic particle equations have been predicted based on first-principles solutions for IED particle (e.g. arxiv:0812.3951, J Phys CS128, 012019, 2008); the equations are long experimentally validated. A critical review of the key experiments suggests that the IED process underlies these equations not just sufficiently but also necessarily. E.g.: 1) A free IED electron solution is a plane wave ψ= Ce^i(kdX-φT) requisite for producing the diffraction fringe in a Davisson-Germer experiment, and of also all basic point-like attributes facilitated by a linear momentum kd and the model structure. It needs not further be a wave packet which produces not a diffraction fringe. 2)The radial partial EM waves, hence the total ψ, of an IED electron will, on both EM theory and experiment basis -not by assumption, enter two slits at the same time, as is requisite for an electron to interfere with itself as shown in double slit experiments. 3) On annihilation, an electron converts (from mass m) to a radiation energy φ without an acceleration which is externally observable and yet requisite by EM theory. So a charge oscillation of frequency φ and its EM waves must regularly present internal of a normal electron, whence the IED model.

  13. An improved search for elementary particles with fractional electric charge

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E.R.

    1996-08-01

    The SLAC Quark Search Group has demonstrated successful operation of a low cost, high mass throughput Millikan apparatus designed to search for fractionally charged particles. About six million silicone oil drops were measured with no evidence of fractional charges. A second experiment is under construction with 100 times greater throughput which will utilize optimized search fluids.

  14. Research program in elementary particle theory, 1980. Progress report

    Energy Technology Data Exchange (ETDEWEB)

    Sudarshan, E. C.G.; Ne' eman, Y.

    1980-01-01

    Research is reported for these subject areas: particle physics in relativistic astrophysics and cosmology; phenomenology of weak and electromagnetic interactions; strong interaction physics, QCD, and quark-parton physics; quantum field theory, quantum mechanics and fundamental problems; groups, gauges, and grand unified theories; and supergeometry, superalgebra, and unification. (GHT)

  15. Going beyond the Standard Model of Elementary Particle Physics

    Indian Academy of Sciences (India)

    2011-11-19

    Nov 19, 2011 ... Higgs Mechanism. ○. Spontaneous symmetry breaking needs a field to be nonzero everywhere. ○. To break SU(2) (threedimensional rotations) at least 44 fields needed. ○. Excitations of one field: Massive spin0 particle. “The Higgs boson”. (Brout, Englert, Guralnik, Hagen, Higgs, Kibble). ○.

  16. Elementary School Interventions: Experimental Evidence on Postsecondary Outcomes

    Science.gov (United States)

    Hemelt, Steven W.; Roth, Kimberly B.; Eaton, William W.

    2013-01-01

    This study exploits a randomized trial of two light-touch elementary school interventions to estimate long-run impacts on postsecondary attendance and attainment. The first is a classroom management technique for developing behavioral skills in children. The second is a curricular intervention aimed at improving students' core reading skills. We…

  17. Theoretical elementary particle research at the University of Florida

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.D.; Ramond, P.M.; Sikivie, P.; Thorn, C.B. [Univ. of Florida, Gainesville, FL (United States)

    1996-12-01

    This is the annual progress report of the theoretical particle theory group at the University of Florida under DoE Grant DE-FG05-86ER40272. At present the group consists of four Full Professors (Field, Ramond, Thorn, Sikivie), two Associate Professors (Qiu, Woodard), and one Assistant Professor (Kennedy). In addition, the group has four postdoctoral research associates and three graduate students. The research of the group covers a broad range of topics in theoretical high energy physics including both theory and phenomenology. Included in this report is a summary of the last several years and an outline of the current research program.

  18. From the universe to the elementary particles a first introduction to cosmology and the fundamental interactions

    CERN Document Server

    Ellwanger, Ulrich

    2012-01-01

    In this book, the author leads the reader, step by step and without any advanced mathematics, to a clear understanding of the foundations of modern elementary particle physics and cosmology. He also addresses current and controversial questions on topics such as string theory. The book contains gentle introductions to the theories of special and general relativity, and also classical and quantum field theory. The essential aspects of these concepts are understood with the help of simple calculations; for example, the force of gravity as a consequence of the curvature of the space-time. Also treated are the Big Bang, dark matter and dark energy, as well as the presently known interactions of elementary particles: electrodynamics, the strong and the weak interactions including the Higgs boson. Finally, the book sketches as yet speculative theories: Grand Unification theories, supersymmetry, string theory and the idea of additional dimensions of space-time. Since no higher mathematical or physics expertise is r...

  19. Spin rotation and oscillations for high energy particles in a crystal and possibility to measure the quadrupole moments and tensor polarizabilities of elementary particles and nuclei

    OpenAIRE

    Baryshevsky, V. G.; Gurinovich, A. A.

    2005-01-01

    It is shown that particle motion in a bent (straight) crystal is accompanied by particle spin rotation and oscillations that allows to measure the tensor electric and magnetic polarizabilities of nuclei and elementary particles. It is shown that channelling of particles in either straight or bent crystal with the polarized nuclei could be used both to analyze polarization of high energy particles and polarize them.

  20. Scientific Thinking in Elementary School: Children's Social Cognition and Their Epistemological Understanding Promote Experimentation Skills

    Science.gov (United States)

    Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate

    2017-01-01

    Do social cognition and epistemological understanding promote elementary school children's experimentation skills? To investigate this question, 402 children (ages 8, 9, and 10) in 2nd, 3rd, and 4th grades were assessed for their experimentation skills, social cognition (advanced theory of mind [AToM]), epistemological understanding (understanding…

  1. Unity of elementary particles and forces for the third family

    Energy Technology Data Exchange (ETDEWEB)

    Chakdar, Shreyashi, E-mail: chakdar@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States); Li Tianjun, E-mail: tli@itp.ac.cn [State Key Laboratory of Theoretical Physics and Kavli Institute for Theoretical Physics China (KITPC), Institute of Theoretical Physics, Chinese Academy of Sciences, Beijing 100190 (China); George P. and Cynthia W. Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Nandi, S., E-mail: s.nandi@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States); Rai, Santosh Kumar, E-mail: santosh.rai@okstate.edu [Department of Physics and Oklahoma Center for High Energy Physics, Oklahoma State University, Stillwater, OK 74078-3072 (United States)

    2012-11-15

    We propose a non-supersymmetric SU(5) model in which only the third family of fermions are unified. The model remedies the non-unification of the three Standard Model couplings in non-supersymmetric SU(5). It also provides a mechanism for baryon number violation which is needed for the baryon asymmetry of the Universe and is not present in the Standard Model. Current experimental constraints on the leptoquark gauge bosons, mediating such baryon and lepton violating interactions in our model, allow their masses to be at the TeV scale. These can be searched for as a (b{tau}) or (tt) resonance at the Large Hadron Collider as predicted in our model.

  2. Models for Quarks and Elementary Particles. Part IV: How Much do We Know of This Universe?

    Directory of Open Access Journals (Sweden)

    Neumann U. K. W.

    2008-07-01

    Full Text Available Essential laws and principles of the natural sciences were discovered at the high aggre- gation levels of matter such as molecules, metal crystals, atoms and elementary parti- cles. These principles reappear in these models in modified form at the fundamental level of the quarks. However, the following is probably true: since the principles apply at the fundamental level of the quarks they also have a continuing effect at the higher aggregation levels. In the manner of the law of mass action, eight processes for weak interaction are formulated, which are also called Weak Processes here. Rules for quark exchange of the reacting elementary particles are named and the quasi-Euclidian or complex spaces introduced in Part I associated with the respective particles. The weak processes are the gateway to the “second” strand of this universe which we practically do not know. The particles with complex space, e.g. the neutrino, form this second strand. According to the physical model of gravitation from Part III the particles of both strands have >-fields and are thus subject to the superposition, which results in the attraction by gravity of the particles of both strands. The weak processes (7 and (8 offer a fair chance for the elimination of highly radioactive waste.

  3. "What's (the) Matter?", A Show on Elementary Particle Physics with 28 Demonstration Experiments

    CERN Document Server

    Dreiner, Herbi K; Borzyszkowski, Mikolaj; Braun, Maxim; Faßbender, Alexander; Hampel, Julia; Hansen, Maike; Hebecker, Dustin; Heepenstrick, Timo; Heinz, Sascha; Hortmanns, Katharina; Jost, Christian; Kortmann, Michael; Kruckow, Matthias U; Leuteritz, Till; Lütz, Claudia; Mahlberg, Philip; Müllers, Johannes; Opferkuch, Toby; Paul, Ewald; Pauli, Peter; Rossbach, Merlin; Schaepe, Steffen; Schiffer, Tobias; Schmidt, Jan F; Schüller-Ruhl, Jana; Schürmann, Christoph; Ubaldi, Lorenzo; Wagner-Carena, Sebastian

    2016-01-01

    We present the screenplay of a physics show on particle physics, by the Physikshow of Bonn University. The show is addressed at non-physicists aged 14+ and communicates basic concepts of elementary particle physics including the discovery of the Higgs boson in an entertaining fashion. It is also demonstrates a successful outreach activity heavily relying on the university physics students. This paper is addressed at anybody interested in particle physics and/or show physics. This paper is also addressed at fellow physicists working in outreach, maybe the experiments and our choice of simple explanations will be helpful. Furthermore, we are very interested in related activities elsewhere, in particular also demonstration experiments relevant to particle physics, as often little of this work is published. Our show involves 28 live demonstration experiments. These are presented in an extensive appendix, including photos and technical details. The show is set up as a quest, where 2 students from Bonn with the aid...

  4. Partitioning of the unpartitionable. A conceivable examination of the atomistic nature of elementary particles; Aufteilungen des Unteilbaren. Eine begriffliche Pruefung der atomistischen Natur von Elementarteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Fox, T.

    2007-07-01

    By a conceivable and historical discussion Tobias Fox developes a philosophical view on the results of modern elementary-particle physics. Possess particles individuality? Is their absolute unpartionability provable by physical methods? In which sense are elementary particles indirectly observable? Are they only nof theoretical importance? Summarizing these questions say: Are elementary particles that, what was thought earlier with the philosophical term of the atom.

  5. Four different animated sub-particles as the origins of the life and creator of different angular momentums of elementary particles

    Science.gov (United States)

    Gholibeigian, Hassan; Gholibeigian, Zeinab

    2015-04-01

    Understanding the internal structure of the proton is crucial challenge for QCD, and one important aspect of this is to understand how the spin of the nucleon is build-up from the angular momentum of its quarks and gluons. In this way, what's the origin of differences between angular momentums of fundamental particles? It may be from their substructures. It seems there are four sub-particles of mater, plant, animal and human in substructure of each fundamental particle (string) as the origins of life and cause of differences between spins of those elementary particles. Material's sub-particle always is on and active. When the environmental conditions became ready for creation of each field of the plant, animal and human, sub-particles of their elementary particles became on and active and then, those elementary particles participated in processes of creation in their own field. God, as the main source of information, has been communicated with their sub-particles and transfers a package (bit) of information and laws (plus standard ethics for human sub-particles) to each of them for process and selection (mutation) of the next step of motion and interaction of their fundamental particles with each other in each Plank's time. This is causality for particles' motion in quantum area.

  6. Computer Assisted English Language Learning in Costa Rican Elementary Schools: An Experimental Study

    Science.gov (United States)

    Alvarez-Marinelli, Horacio; Blanco, Marta; Lara-Alecio, Rafael; Irby, Beverly J.; Tong, Fuhui; Stanley, Katherine; Fan, Yinan

    2016-01-01

    This study presents first-year findings of a 25-week longitudinal project derived from a two-year longitudinal randomized trial study at the elementary school level in Costa Rica on effective computer-assisted language learning (CALL) approaches in an English as a foreign language (EFL) setting. A pre-test-post-test experimental group design was…

  7. Supporting Scientific Experimentation and Reasoning in Young Elementary School Students

    Science.gov (United States)

    Varma, Keisha

    2014-06-01

    Researchers from multiple perspectives have shown that young students can engage in the scientific reasoning involved in science experimentation. However, there is little research on how well these young students learn in inquiry-based learning environments that focus on using scientific experimentation strategies to learn new scientific information. This work investigates young children's science concept learning via inquiry-based instruction on the thermodynamics system in a developmentally appropriate, technology-supported learning environment. First- and third-grade students participate in three sets of guided experimentation activities that involve using handheld computers to measure change in temperature given different types of insulation materials. Findings from pre- and post-comparisons show that students at both grade levels are able to learn about the thermodynamics system through engaging in the guided experiment activities. The instruction groups outperformed the control groups on multiple measures of thermodynamics knowledge, and the older children outperform the younger children. Knowledge gains are discussed in the context of mental models of the thermodynamics system that include the individual concepts mentioned above and the relationships between them. This work suggests that young students can benefit from science instruction centered on experimentation activities. It shows the benefits of presenting complex scientific information authentic contexts and the importance of providing the necessary scaffolding for meaningful scientific inquiry and experimentation.

  8. Experimental study on inter-particle acoustic forces.

    Science.gov (United States)

    Garcia-Sabaté, Anna; Castro, Angélica; Hoyos, Mauricio; González-Cinca, Ricard

    2014-03-01

    A method for the experimental measurement of inter-particle forces (secondary Bjerknes force) generated by the action of an acoustic field in a resonator micro-channel is presented. The acoustic radiation force created by an ultrasonic standing wave moves suspended particles towards the pressure nodes and the acoustic pressure induces particle volume oscillations. Once particles are in the levitation plane, transverse and secondary Bjerknes forces become important. Experiments were carried out in a resonator filled with a suspension composed of water and latex particles of different size (5-15 μm) at different concentrations. Ultrasound was generated by means of a 2.5 MHz nominal frequency transducer. For the first time the acoustic force generated by oscillating particles acting on other particles has been measured, and the critical interaction distance in various cases has been determined. Inter-particle forces on the order of 10(-14) N have been measured by using this method.

  9. Models for Quarks and Elementary Particles --- Part I: What is a Quark?

    Directory of Open Access Journals (Sweden)

    Neumann U. K. W.

    2008-04-01

    Full Text Available A quark is not a tiny sphere. The formal model idea is based on a vector group which is constructed like an outer vector product. The vectors perform dynamic movements. Two vectors (vector pair which rotate in opposite directions in a plane have an increasing and diminishing result vector as consequence. At the same time the vector group rotates about the bisectrix of the vector pair. The two movements matched to each other result in that the tip of the resultant vector draws so-called geometrical locus loops in a plane. The u- and the d-quarks have characteristic loops. Each vector group has its own orthogonal, hyperbolic space. By joining three such spaces each, two groups of spaces, one group with a quasi-Euclidian and one group with a complex space are obtained. Based on the u- and d-quarks characterized with their movements and spaces a first elementary particle order is compiled.

  10. 12th DESY Workshop on Elementary Particle Physics: Loops and Legs in Quantum Field Theory

    CERN Document Server

    LL2014

    2014-01-01

    The bi-annual international conference “Loops and Legs in Quantum Field Theory” has been held at Weimar, Germany, from April 27 to May 02, 2014. It has been the 12th conference of this series, started in 1992. The main focus of the conference are precision calculations of multi- loop and multi-leg processes in elementary particle physics for processes at present and future high-energy facilities within and beyond the Standard Model. At present many physics questions studied deal with processes at the LHC and future facilities like the ILC. A growing number of contributions deals with important developments in the field of computational technologies and algorithmic methods, including large-scale computer algebra, efficient methods to compute large numbers of Feynman diagrams, analytic summation and integration methods of various kinds, new related function spaces, precise numerical methods and Monte Carlo simulations. The present conference has been attended by more than 110 participants from all over the ...

  11. Review of the Elementary Particles Physics in the External Electromagnetic Fields Studies at KEK

    Science.gov (United States)

    Konstantinova, O. Tanaka

    2017-03-01

    High Energy Accelerator Research Organization (KEK [1]) is a world class accelerator-based research laboratory. The field of its scientific interests spreads widely from the study of fundamental properties of matter, particle physics, nuclear physics to materials science, life science, technical researches, and industrial applications. Research outcomes from the laboratory achieved making use of high-energy particle beams and synchrotron radiation. Two synchrotron facilities of KEK, the Photon Factory (PF) ring and the Photon Factory Advanced Ring (PF-AR) are the second biggest synchrotron light source in Japan. A very wide range of the radiated light, from visible light to X-ray, is provided for a variety of materials science, biology, and life science [2]. KEK strives to work closely with national and international research institutions, promoting collaborative research activities. Advanced research and facilities provision are key factors to be at the frontier of the accelerator science. In this review I am going to discuss KEK overall accelerator-based science, and to consider light sources research and development. The state of arts of the current projects with respect to the elementary particles physics in the external electromagnetic fields is also stressed here.

  12. Is the Field of Numbers a Real Physical Field? On the Frequent Distribution and Masses of the Elementary Particles

    Directory of Open Access Journals (Sweden)

    Belyakov A. V.

    2010-04-01

    Full Text Available Frequent distributions of the databases of the numerical values obtained by resolving algorithms, which describe physical and other processes, give a possibility for bonding the probability of that results the algorithms get. In the frequent distribution of the fractions of integers (rational numbers, local maxima which meet the ratios of masses of the elementary particles have been found.

  13. Research in elementary particle physics. Annual report, January 1--October 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1992-11-01

    Experimental and theoretical work on high energy physics is reviewed. Included are preparations to study high-energy electron-proton interactions at HERA, light-cone QCD, decays of charm and beauty particles, neutrino oscillation, electron-positron interactions at CLEO II, detector development, and astrophysics and cosmology.

  14. An experimental study on particle effects in liquid sheets

    Directory of Open Access Journals (Sweden)

    Sauret Alban

    2017-01-01

    Full Text Available Many industrial processes, such as surface coating or liquid transport in tubes, involve liquid sheets or thin films of suspensions. In these situations, the thickness of the liquid film becomes comparable to the particle size, which leads to unexpected dynamics. In addition, the classical constitutive rheological law for suspensions cannot be applied as the continuum approximation is no longer valid. Here, we consider experimentally a transient particle-laden liquid sheet that expands radially. We characterize the influence of the particles on the shape of the liquid film and the atomization process. We highlight that the presence of particles modifies the thickness and stability of the liquid sheet. Our study suggests that the influence of particles through capillary effects can modify significantly the dynamics of processes that involve suspensions and particles confined in liquid films.

  15. Scientific thinking in elementary school: Children's social cognition and their epistemological understanding promote experimentation skills.

    Science.gov (United States)

    Osterhaus, Christopher; Koerber, Susanne; Sodian, Beate

    2017-03-01

    Do social cognition and epistemological understanding promote elementary school children's experimentation skills? To investigate this question, 402 children (ages 8, 9, and 10) in 2nd, 3rd, and 4th grades were assessed for their experimentation skills, social cognition (advanced theory of mind [AToM]), epistemological understanding (understanding the nature of science), and general information-processing skills (inhibition, intelligence, and language abilities) in a whole-class testing procedure. A multiple indicators multiple causes model revealed a significant influence of social cognition (AToM) on epistemological understanding, and a McNemar test suggested that children's development of AToM is an important precursor for the emergence of an advanced, mature epistemological understanding. Children's epistemological understanding, in turn, predicted their experimentation skills. Importantly, this relation was independent of the common influences of general information processing. Significant relations between experimentation skills and inhibition, and between epistemological understanding, intelligence, and language abilities emerged, suggesting that general information processing contributes to the conceptual development that is involved in scientific thinking. The model of scientific thinking that was tested in this study (social cognition and epistemological understanding promote experimentation skills) fitted the data significantly better than 2 alternative models, which assumed nonspecific, equally strong relations between all constructs under investigation. Our results support the conclusion that social cognition plays a foundational role in the emergence of children's epistemological understanding, which in turn is closely related to the development of experimentation skills. Our findings have significant implications for the teaching of scientific thinking in elementary school and they stress the importance of children's epistemological understanding in

  16. Instrumentation in Elementary Particle Physics: Proceedings of 4rd Icfa School

    Science.gov (United States)

    Anjos, J. C.; Hartill, D.; Sauli, F.; Sheaff, M.

    The Table of Contents for the full book PDF is as follows: * Foreword * Preface * Acknowledgements * LECTURES * Basic Processes in Particle Detection * Front-End Electronic for High Energy Physics * Solid State Detectors * Experimental System in High Energy Physics * SPECIAL TALKS * New Ideas in Detectors for High Energy Physics * The Development of Ring Imaging Cherenkov (RICH) Counters and Their Application in DELPHI at LEP. * Use of Transition Radiation Detectors (TRD's) for Particle Identification * Experimental Status of the Search for the Quark-Gluon Plasma in Ultra-Relativistic Heavy Ion Interactions * LABORATORY SESSIONS * Silicon Detector and Signal Processing Experiment * Laboratory Session on Drift Chambers * Detecting uv-Photons in a Drift Chamber * A Small MWPC for Pedagogical USE * Principles of Position Sensitive Proportional Chambers * Imaging Detector for X-Ray Radiography * Lifetime of Cosmic Ray Muons (including Notes on Statistics for Physicists, Revised, by J. Orear) * List of Participants

  17. Optimizing experimental parameters for tracking of diffusing particles

    DEFF Research Database (Denmark)

    Vestergaard, Christian L.

    2016-01-01

    We describe how a single-particle tracking experiment should be designed in order for its recorded trajectories to contain the most information about a tracked particle's diffusion coefficient. The precision of estimators for the diffusion coefficient is affected by motion blur, limited photon...... statistics, and the length of recorded time series. We demonstrate for a particle undergoing free diffusion that precision is negligibly affected by motion blur in typical experiments, while optimizing photon counts and the number of recorded frames is the key to precision. Building on these results, we...... describe for a wide range of experimental scenarios how to choose experimental parameters in order to optimize the precision. Generally, one should choose quantity over quality: experiments should be designed to maximize the number of frames recorded in a time series, even if this means lower information...

  18. Experimental studies of tuned particle damper: Design and characterization

    Science.gov (United States)

    Zhang, Kai; Xi, Yanhui; Chen, Tianning; Ma, Zhihao

    2018-01-01

    To better suppress the structural vibration in the micro vibration and harsh environment, a new type of damper, tuned particle damper (TPD), was designed by combining the advantage of classical dynamic vibration absorber (DVA) and particle damper (PD). An equivalent theoretical model was established to describe the dynamic behavior of a cantilever system treated with TPD. By means of a series of sine sweep tests, the dynamic characteristic of TPD under different excitation intensity was explored and the damping performance of TPD was investigated by comparing with classical DVA and PD with the same mass ratio. Experimental results show that with the increasing of excitation intensity TPD shows two different dynamic characteristics successively, i.e., PD-like and DVA-like. TPD shows a wider suppression frequency band than classical DVA and better practicability than PD in the micro vibration environment. Moreover, to characterize the dynamic characteristic of TPD, a simple evaluation of the equivalent dynamic mass and equivalent dynamic damping of the cantilever system treated with TPD was performed by fitting the experimental data to the presented theoretical model. Finally, based on the rheology behaviors of damping particles reported by the previous research results, an approximate phase diagram which shows the motion states of damping particles in TPD was employed to analyze the dynamic characteristic of TPD and several motion states of damping particles in TPD were presented via a high-speed camera.

  19. A guide to experimental particle physics literature, 1991-1996

    Energy Technology Data Exchange (ETDEWEB)

    Ezhela, V.V.; Filimonov, B.B.; Lugovsky, S.B. [Inst. for High Energy Physics, Moscow (Russian Federation)] [and others

    1996-10-01

    We present an indexed guide to experimental particle physics literature for the years 1991 - 1996. Approximately 4200 papers are indexed by (1) Beam/Target/Momentum (2) Reaction/Momentum/Data-Descriptor (including the final state) (3) Particle/Decay (4) Accelerator/Experiment/Detector. All indices are cross-referenced to the paper`s title and references in the ID/Reference/Title index. The information presented in this guide is also publicly available on a regularly-updated DATAGUIDE database from the World Wide Web.

  20. Light scattering by particles in water theoretical and experimental foundations

    CERN Document Server

    Jonasz, Miroslaw

    2007-01-01

    Light scattering-based methods are used to characterize small particles suspended in water in a wide range of disciplines ranging from oceanography, through medicine, to industry. The scope and accuracy of these methods steadily increases with the progress in light scattering research. This book focuses on the theoretical and experimental foundations of the study and modeling of light scattering by particles in water and critically evaluates the key constraints of light scattering models. It begins with a brief review of the relevant theoretical fundamentals of the interaction of light with condensed matter, followed by an extended discussion of the basic optical properties of pure water and seawater and the physical principles that explain them. The book continues with a discussion of key optical features of the pure water/seawater and the most common components of natural waters. In order to clarify and put in focus some of the basic physical principles and most important features of the experimental data o...

  1. Experimental activities in the early years of elementary school: a methodological tool for construction of the teaching-learning process

    Directory of Open Access Journals (Sweden)

    Ana de Souza Lima

    2017-07-01

    Full Text Available Focusing on the early years of elementary school, this study evaluated the impact of experimental activities based in the scientific method and preconceptions on the learning and memorization of concepts and phenomena associated with the fermentation process. The different activities were carried out through an experimental course (20hs, with students of elementary school from school municipal Diacono Joao Luiz Pozzobon, Santa Maria-RS. The research involved 20 students, with 6 and 7 old years. The evaluation was performed by comparing the interview responses made before the course (pre-test and after the course (post-test. The post-tests were applied at the end of the experimental course, and after 6 and 12 months. The experimental activities facilitated the acquisition and retention of new concepts. The data show that "experimental activities" can be used by teachers in early grades as a methodological tool to complement the teaching-learning process.

  2. Experimental investigation of suspended particles transport through porous media: particle and grain size effect.

    Science.gov (United States)

    Liu, Quansheng; Cui, Xianze; Zhang, Chengyuan; Huang, Shibing

    2016-01-01

    Particle and grain size may influence the transportation and deposition characteristics of particles within pollutant transport and within granular filters that are typically used in wastewater treatment. We conducted two-dimensional sandbox experiments using quartz powder as the particles and quartz sand as the porous medium to study the response of transportation and deposition formation to changes in particle diameter (ds, with median diameter 18, 41, and 82 μm) and grain diameter (dp, with median diameter 0.36, 1.25, and 2.82 mm) considering a wide range of diameter ratios (ds/dp) from 0.0064 to 0.228. Particles were suspended in deionized water, and quartz sand was used as the porous medium, which was meticulously cleaned to minimize any physicochemical and impurities effects that could result in indeterminate results. After the experiments, the particle concentration of the effluent and particle mass per gram of dry sands were measured to explore changes in transportation and deposition characteristics under different conditions. In addition, a micro-analysis was conducted to better analyse the results on a mesoscopic scale. The experimental observation analyses indicate that different diameter ratios (ds/dp) may lead to different deposit formations. As ds/dp increased, the deposit formation changed from 'Random Deposition Type' to 'Gradient Deposition Type', and eventually became 'Inlet Deposition Type'.

  3. A Comparison of Four Reading Interventions from Struggling Elementary Students Using Brief Experimental Analysis and Extended Intervention Analysis

    Science.gov (United States)

    Mong, Kristi W.; Mong, Michael D.; Henington, Carlen; Doggett, R. A.

    2012-01-01

    Brief experimental analyses (BEA) have been used to identify reading interventions to increase the oral reading fluency (ORF) of students having difficulty learning to read. Four interventions, repeated reading, listening passage preview, phrase drill, and contingent reinforcement were implemented with four elementary aged students performing…

  4. Experimental Longitudinal Test of the Influence of Autonomy-Supportive Teaching on Motivation for Participation in Elementary School Physical Education

    Science.gov (United States)

    Leptokaridou, Elisavet T.; Vlachopoulos, Symeon P.; Papaioannou, Athanasios G.

    2016-01-01

    The present study examined the efficacy of autonomy-supportive teaching during elementary school physical education (PE) in influencing pupils' enjoyment, fear of failure, boredom and effort. A sample of 54 pupils attending fifth and sixth grades comprised the control group (typical instruction; n = 27) and the experimental group…

  5. "Loops and Legs in Quantum Field Theory", 12th DESY Workshop on Elementary Particle Physics

    Science.gov (United States)

    The bi-annual international conference "Loops and Legs in Quantum Field Theory" has been held at Weimar, Germany, from April 27 to May 02, 2014. It has been the 12th conference of this series, started in 1992. The main focus of the conference are precision calculations of multi- loop and multi-leg processes in elementary particle physics for processes at present and future high-energy facilities within and beyond the Standard Model. At present many physics questions studied deal with processes at the LHC and future facilities like the ILC. A growing number of contributions deals with important developments in the field of computational technologies and algorithmic methods, including large-scale computer algebra, efficient methods to compute large numbers of Feynman diagrams, analytic summation and integration methods of various kinds, new related function spaces, precise numerical methods and Monte Carlo simulations. The present conference has been attended by more than 110 participants from all over the world, presenting more than 75 contributions, most of which have been written up for these pro- ceedings. The present volume demonstrates in an impressive way the enormous development of the field during the last few years, reaching the level of 5-loop calculations in QCD and a like- wise impressive development in massive next-to-leading order and next-to-next-to-leading order processes. Computer algebraic and numerical calculations require terabyte storage and many CPU years, even after intense parallelization, to obtain state-of-the-art theoretical predictions. The city of Weimar gave a suitable frame to the conference, with its rich history, especially in literature, music, arts, and architecture. Goethe, Schiller, Wieland, Herder, Bach and Liszt lived there and created many of their masterpieces. The many young participants signal that our field is prosperous and faces an exciting future. The conference hotel "Kaiserin Augusta" offered a warm hospitality and

  6. Experimental investigation on laser removal of carbon and tungsten particles

    Energy Technology Data Exchange (ETDEWEB)

    Vatry, A. [Laboratoire Lasers, Plasmas et Procedes Photoniques, campus de Luminy, 163 av. de Luminy, 13009 Marseille (France); Association Euratom/CEA, DSM/IRFM, 13108 Saint Paul lez Durance (France)], E-mail: vatry@lp3.univ-mrs.fr; Habib, M. Naiim; Delaporte, Ph.; Sentis, M.; Grojo, D. [Laboratoire Lasers, Plasmas et Procedes Photoniques, campus de Luminy, 163 av. de Luminy, 13009 Marseille (France); Grisolia, C.; Rosanvallon, S. [Association Euratom/CEA, DSM/IRFM, 13108 Saint Paul lez Durance (France)

    2009-03-01

    During the operation of the ITER fusion facility, particles with size from 10 nm to 100 {mu}m, mainly composed of carbon, beryllium, and tungsten, will be produced. Since dust could lead to safety issues, it must be periodically removed from the facility in order to keep their quantity below the safety limit requirements. In this context, laser cleaning appeared as a very promising technique, and investigations have to be done to understand the physical processes and optimize the procedure. Several experiments were carried out to improve the understanding of the phenomena involved during the laser-induced removal of Carbon particles. The ejection mechanisms have been experimentally studied for different irradiation conditions with nanosecond laser pulses. The removal efficiency and the fluence threshold were determined by optical microscopy. The influence of the substrate was studied for the dry laser cleaning configuration. This study presents scanning electronic microscopy pictures which show that the particle removal leads to a damage of the substrate. These damages give evidences on the ablation mechanism. The laser shock cleaning was also studied. In this configuration, the laser-induced shock wave can be used to push the particles away from the surface. This technique appears to be very useful to clean shadowed areas.

  7. Experimental observation of crystalline particle flows in toroidal dust clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wilms, Jochen, E-mail: wilms@physik.uni-kiel.de; Piel, Alexander [IEAP, Christian-Albrechts-Universität, D-24098 Kiel (Germany); Reichstein, Torben [IEAP, Christian-Albrechts-Universität, D-24098 Kiel (Germany); DME, Kiel University of Applied Sciences, Grenzstr. 3, D-24147 Kiel (Germany)

    2015-06-15

    The dust flow in a toroidal dust trap is studied experimentally. The flow is driven by the Hall component of the ion drag force in a magnetized plasma. Dust density waves are found in a torus with a large minor radius a, which allows for several wavelength, 2a>5λ, in the (mostly) radial direction of the ion flow. Beyond an intermediate state with radial sloshing oscillations, a crystalline dust flow with suppressed wave activity could be realized for 2a<2λ. The particles arrange themselves in distinct layers with hexagonal-like local order. Smooth transitions between states with different numbers of layers are found in the inhomogeneous flow.

  8. An elementary singularity-free Rotational Brownian Dynamics algorithm for anisotropic particles

    NARCIS (Netherlands)

    Ilie, Ioana Mariuca; Briels, Willem J.; den Otter, Wouter K.

    2015-01-01

    Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a

  9. From the universe to the elementary particles. A first introduction to cosmology and the fundamental interactions. 3. ed.; Vom Universum zu den Elementarteilchen. Eine erste Einfuehrung in die Kosmologie und die fundamentalen Wechselwirkungen

    Energy Technology Data Exchange (ETDEWEB)

    Ellwanger, Ulrich [Paris-Sud Univ. (France). Lab. de Physique Theorique et Hautes Energies

    2015-07-01

    The aim of this text is to present the present status of our knowledges of the natural laws from cosmology to the elementary particles. The text begins with a survey starting from the universe via atoms, their nuclei until to the elementary particles. Thereafter the corresponding concepts and physical phenomena are detailedly discussed. Finally the at time still speculative theories are briefly scatched. (HSI)

  10. Cornell's LEPP, CHESS research labs expected to get $124 million in NSF funding for elementary particle and X-ray research

    CERN Multimedia

    2003-01-01

    "Cornell University will be awarded up to $124 million over the next five years by the National Science Foundation (NSF) to support research at the Laboratory for Elementary-Particle Physics (LEPP) and the Cornell High Energy Synchrotron Source (CHESS), a national user facility" (1 page).

  11. An elementary singularity-free Rotational Brownian Dynamics algorithm for anisotropic particles

    Energy Technology Data Exchange (ETDEWEB)

    Ilie, Ioana M.; Briels, Wim J. [Computational Biophysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Otter, Wouter K. den, E-mail: w.k.denotter@utwente.nl [Computational Biophysics, Faculty of Science and Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); MESA+ Institute for Nanotechnology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands); Multi Scale Mechanics, Faculty of Engineering Technology, University of Twente, P.O. Box 217, 7500 AE Enschede (Netherlands)

    2015-03-21

    Brownian Dynamics is the designated technique to simulate the collective dynamics of colloidal particles suspended in a solution, e.g., the self-assembly of patchy particles. Simulating the rotational dynamics of anisotropic particles by a first-order Langevin equation, however, gives rise to a number of complications, ranging from singularities when using a set of three rotational coordinates to subtle metric and drift corrections. Here, we derive and numerically validate a quaternion-based Rotational Brownian Dynamics algorithm that handles these complications in a simple and elegant way. The extension to hydrodynamic interactions is also discussed.

  12. Research program in elementary particle theory. Progress report, 1975--1976. [Summaries of research activities

    Energy Technology Data Exchange (ETDEWEB)

    Sudarshan, E.C.G.; Ne' eman, Y.

    1976-01-01

    Research on particle theory is summarized including field theory models, phenomenological applications of field theory, strong interactions, the algebraic approach to weak and electromagnetic interactions, and superdense matter. A list of reports is also included. (JFP)

  13. Elementary particle interactions. [Dept. of Physics and Astronomy, Univ. of Tennessee, Knoxville, Tennessee

    Energy Technology Data Exchange (ETDEWEB)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.

    1992-10-01

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out.

  14. Elementary particle interactions. Progress report, October 1, 1991--September 30, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Ward, B.F.L.

    1992-10-01

    Work continues on strange particle production in weak interactions using data from a high-energy neutrino exposure in a freon bubble chamber. Meson photoproduction has also consumed considerable effort. Detector research and development activities have been carried out.

  15. Number Worlds: Visual and Experimental Access to Elementary Number Theory Concepts

    Science.gov (United States)

    Sinclair, Nathalie; Zazkis, Rina; Liljedahl, Peter

    2004-01-01

    Recent research demonstrates that many issues related to the structure of natural numbers and the relationship among numbers are not well grasped by students. In this article, we describe a computer-based learning environment called "Number Worlds" that was designed to support the exploration of elementary number theory concepts by…

  16. Experimental study on effects of particle shape and operating conditions on combustion characteristics of single biomass particles

    DEFF Research Database (Denmark)

    Momenikouchaksaraei, Maryam; Yin, Chungen; Kær, Søren Knudsen

    2013-01-01

    An experimental study is performed to investigate the ignition, devolatilization, and burnout of single biomass particles of various shapes and sizes under process conditions that are similar to those in an industrial combustor. A charge-coupled device (CCD) camera is used to record the whole...... combustion process. For the particles with similar volume (mass), cylindrical particles are found to lose mass faster than spherical particles and the burnout time is shortened by increasing the particle aspect ratio (surface area). The conversion times of cylindrical particles with almost the same surface...... area/volume ratio are very close to each other. The ignition, devolatilization, and burnout times of cylindrical particles are also affected by the oxidizer temperature and oxygen concentration, in which the oxygen concentration is found to have a more pronounced effect on the conversion times at lower...

  17. Experimental Study on Effects of Particle Shape and Operating Conditions on Combustion Characteristics of Single Biomass Particles

    DEFF Research Database (Denmark)

    Momeni, M.; Yin, Chungen; Kær, Søren Knudsen

    2013-01-01

    An experimental study is performed to investigate the ignition, devolatilization, and burnout of single biomass particles of various shapes and sizes under process conditions that are similar to those in an industrial combustor. A chargecoupled device (CCD) camera is used to record the whole...... combustion process. For the particles with similar volume (mass), cylindrical particles are found to lose mass faster than spherical particles and the burnout time is shortened by increasing the particle aspect ratio (surface area). The conversion times of cylindrical particles with almost the same surface...... area/volume ratio are very close to each other. The ignition, devolatilization, and burnout times of cylindrical particles are also affected by the oxidizer temperature and oxygen concentration, in which the oxygen concentration is found to have a more pronounced effect on the conversion times at lower...

  18. Closeout for U.S. Department of Energy Final Technical Report for University of Arizona grant DOE Award Number DE-FG03-95ER40906 From 1 February 1995 to 31 January 2004 Grant title: Theory and Phenomenology of Strong and Weak High Energy Physics (Task A) and Experimental Elementary Particle Physics (Task B)

    Energy Technology Data Exchange (ETDEWEB)

    Rutherfoord, John; Toussaint, Doug; Sarcevic, Ina

    2005-03-03

    The following pages describe the high energy physics program at the University of Arizona which was funded by DOE grant DE-FG03-95ER40906, for the period 1 February 1995 to 31 January 2004. In this report, emphasis was placed on more recent accomplishments. This grant was divided into two tasks, a theory task (Task A) and an experimental task (Task B but called Task C early in the grant period) with separate budgets. Faculty supported by this grant, for at least part of this period, include, for the theory task, Adrian Patrascioiu (now deceased), Ina Sarcevic, and Douglas Toussaint., and, for the experimental task, Elliott Cheu, Geoffrey Forden, Kenneth Johns, John Rutherfoord, Michael Shupe, and Erich Varnes. Grant monitors from the Germantown DOE office, overseeing our grant, changed over the years. Dr. Marvin Gettner covered the first years and then he retired from the DOE. Dr. Patrick Rapp worked with us for just a few years and then left for a position at the University of Puerto Rico. Dr. Kathleen Turner took his place and continues as our grant monitor. The next section of this report covers the activities of the theory task (Task A) and the last section the activities of the experimental task (Task B).

  19. Towards reproducible experimental studies for non-convex polyhedral shaped particles

    Science.gov (United States)

    Wilke, Daniel N.; Pizette, Patrick; Govender, Nicolin; Abriak, Nor-Edine

    2017-06-01

    The packing density and flat bottomed hopper discharge of non-convex polyhedral particles are investigated in a systematic experimental study. The motivation for this study is two-fold. Firstly, to establish an approach to deliver quality experimental particle packing data for non-convex polyhedral particles that can be used for characterization and validation purposes of discrete element codes. Secondly, to make the reproducibility of experimental setups as convenient and readily available as possible using affordable and accessible technology. The primary technology for this study is fused deposition modeling used to 3D print polylactic acid (PLA) particles using readily available 3D printer technology. A total of 8000 biodegradable particles were printed, 1000 white particles and 1000 black particles for each of the four particle types considered in this study. Reproducibility is one benefit of using fused deposition modeling to print particles, but an extremely important additional benefit is that specific particle properties can be explicitly controlled. As an example in this study the volume fraction of each particle can be controlled i.e. the effective particle density can be adjusted. In this study the particle volumes reduces drastically as the non-convexity is increased, however all printed white particles in this study have the same mass within 2% of each other.

  20. Towards reproducible experimental studies for non-convex polyhedral shaped particles

    Directory of Open Access Journals (Sweden)

    Wilke Daniel N.

    2017-01-01

    Full Text Available The packing density and flat bottomed hopper discharge of non-convex polyhedral particles are investigated in a systematic experimental study. The motivation for this study is two-fold. Firstly, to establish an approach to deliver quality experimental particle packing data for non-convex polyhedral particles that can be used for characterization and validation purposes of discrete element codes. Secondly, to make the reproducibility of experimental setups as convenient and readily available as possible using affordable and accessible technology. The primary technology for this study is fused deposition modeling used to 3D print polylactic acid (PLA particles using readily available 3D printer technology. A total of 8000 biodegradable particles were printed, 1000 white particles and 1000 black particles for each of the four particle types considered in this study. Reproducibility is one benefit of using fused deposition modeling to print particles, but an extremely important additional benefit is that specific particle properties can be explicitly controlled. As an example in this study the volume fraction of each particle can be controlled i.e. the effective particle density can be adjusted. In this study the particle volumes reduces drastically as the non-convexity is increased, however all printed white particles in this study have the same mass within 2% of each other.

  1. Shape-constrained uncertainty quantification in unfolding steeply falling elementary particle spectra

    CERN Document Server

    Kuusela, Mikael

    2015-01-01

    The high energy physics unfolding problem is an important statistical inverse problem arising in data analysis at the Large Hadron Collider at CERN. The problem arises in making nonparametric inferences about a particle spectrum from measurements smeared by the finite resolution of the particle detectors. Existing unfolding methodology has major practical limitations stemming from ad hoc discretization and regularization of the problem. As a result, confidence intervals derived using the current methods can have significantly lower coverage than expected. In this work, we regularize the problem by imposing physically justified shape constraints. We quantify the uncertainty by constructing a nonparametric confidence set for the true spectrum consisting of all spectra that satisfy the shape constraints and that predict observations within an appropriately calibrated level of fit to the data. Projecting that set produces simultaneous confidence intervals for all functionals of the spectrum, including averages wi...

  2. Task A: Research in theoretical elementary particle physics at the University of Florida; Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.D.; Ramond, P.M.; Sikivie, P.; Thorn, C.B.

    1993-11-01

    This is the Annual Progress Report of the theoretical particle theory group at the University of Florida under DoE Grant DE-FG05-86ER40272. At present our group consists of four Full Professors (Field, Ramond, Thorn, Sikivie) and three Assistant Professors (Qiu, Woodard, Kennedy). Dallas Kennedy recently joined our group increasing the Particle Theory faculty to seven. In addition, we have three postdoctoral research associates, an SSC fellow, and eight graduate students. The research of our group covers a broad range of topics in theoretical high energy physics with balance between theory and phenomenology. Included in this report is a summary of the last several years of operation of the group and an outline of our current research program.

  3. Experimental scattering matrices of clouds and randomly oriented particles

    NARCIS (Netherlands)

    Muñoz, O.; Hovenier, J.W.; Kolokolova, L.; Hough, J.; Levasseur-Regourd, A.C.

    2015-01-01

    In the atmospheres of planets and satellites, liquid particles may occur in the form of clouds, hazes, fog, and rain. The liquid can be water as is the case in the atmosphere of the Earth but also other materials, like sulfuric acid that occurs in the atmosphere of Venus. These liquid particles can

  4. The Discovery of the Tau Lepton and the Changes in Elementary Particle Physics in 40 Years

    Science.gov (United States)

    Perl, M.

    2003-10-22

    This is a history of my discovery of the tau lepton in the 1970s for which I was awarded the Nobel Prize in Physics. I have previously described some aspects of the discovery. In 1996 in my collection of papers entitled, ''Reflections on Experimental Science,'' I gave a straightforward account of the experimental method and the physics involved in the discovery as an introduction to the collection. In a 2002 paper written with Mary A. Meyer published in the journal ''Theoria et Historia Scientiarum'' I used the story of the discovery to outline my thoughts on the practice of experimental science. That 2002 paper was written primarily for young women and men who are beginning their lives in science and it was based on a lecture given at Los Alamos National Laboratory. Some of the historical material in this paper has appeared in those two earlier papers.

  5. THE DISCOVERY OF THE TAU LEPTON AND THE CHANGES IN ELEMENTARY PARTICLE PHYSICS IN 40 YEARS

    Energy Technology Data Exchange (ETDEWEB)

    Perl, M.

    2003-10-22

    This is a history of my discovery of the tau lepton in the 1970s for which I was awarded the Nobel Prize in Physics. I have previously described some aspects of the discovery. In 1996 in my collection of papers entitled, ''Reflections on Experimental Science,'' I gave a straightforward account of the experimental method and the physics involved in the discovery as an introduction to the collection. In a 2002 paper written with Mary A. Meyer published in the journal ''Theoria et Historia Scientiarum'' I used the story of the discovery to outline my thoughts on the practice of experimental science. That 2002 paper was written primarily for young women and men who are beginning their lives in science and it was based on a lecture given at Los Alamos National Laboratory. Some of the historical material in this paper has appeared in those two earlier papers.

  6. Microcosmos the world of elementary particles : fictional discussions between Einstein, Newton, and Gell-Mann

    CERN Document Server

    Fritzsch, Harald

    2014-01-01

    This book provides a broad introduction into the field of particle physics for the general reader through virtual discussions among prominent physicists, Albert Einstein, Murray Gell-Mann, Issac Newton and a modern physicists. Matter is composed of quarks and electrons. The electrons interact with the atomic nuclei by the exchange of photons. The forces between the quarks are generated by the exchange of gluons, which leads to the confinement of the quarks. The weak bosons provide the weak forces among the leptons and quarks. The book is suitable for non-experts in physics. Readership: General readers, students and researchers in physics.

  7. Research in theoretical elementary particle physics at the University of Florida: Task A. Annual progress report

    Energy Technology Data Exchange (ETDEWEB)

    Field, R.D.; Ramond, P.M.; Sikivie, P.; Thorn, C.B.

    1994-12-01

    This is the Annual Progress Report of the theoretical particle theory group at the University of Florida under DOE Grant DE-FG05-86ER40272. At present our group consists of four Full Professors (Field, Ramond, Thorn, Sikivie), one Associate Professor (Woodard), and two Assistant Professors (Qiu, Kennedy). In addition, we have four postdoctoral research associates and seven graduate students. The research of our group covers a broad range of topics in theoretical high energy physics including both theory and phenomenology. Included in this report is a summary of the last several years, an outline of our current research program.

  8. Experimental extractions of particle position from inline holograms using single coefficient of Wigner-Ville analysis

    Science.gov (United States)

    Widjaja, Joewono; Dawprateep, Saowaros; Chuamchaitrakool, Porntip

    2017-07-01

    Extractions of particle positions from inline holograms using a single coefficient of Wigner-Ville distribution (WVD) are experimentally verified. WVD analysis of holograms gives local variation of fringe frequency. Regardless of an axial position of particles, one of the WVD coefficients has the unique characteristics of having the lowest amplitude and being located on a line with a slope inversely proportional to the particle position. Experimental results obtained using two image sensors with different resolutions verify the feasibility of the present method.

  9. Models for Quarks and Elementary Particles. Part II: What is Mass?

    Directory of Open Access Journals (Sweden)

    Neumann U. K. W.

    2008-04-01

    Full Text Available It is extremely productive to give the resultant vector ( EV from the outer vector product (Part I of this article series a physical significance. The EV is assumed as electric flux < with the dimensions [Vm]. Based on Maxwell’s laws this develops into the idea of the magnetic monopole (MMP in each quark. The MMP can be brought in relation with the Dirac monopole. The massless MMP is a productive and important idea on the one hand to recognise what mass is and on the other hand to develop the quark structure of massless photon (-likes from the quark composition of the electron. Based on the experiments by Shapiro it is recognised that the sinusoidal oscillations of the quark can be spiralled in the photons. In an extreme case the spiralling of such a sinusoidal arc produces the geometric locus loop of a quark in a mass-loaded particle.

  10. Particle propagator in elementary quantum mechanics: a new path integral derivation

    Energy Technology Data Exchange (ETDEWEB)

    Ansoldi, Stefano; Spallucci, Euro [Dipartimento di Fisica Teorica, Universita di Trieste, and INFN, Sezione di Trieste, Trieste (Italy)]. E-mails: ansoldi@trieste.infn.it and spallucci@trieste.infn.it; Aurilia, Antonio [Department of Physics, California State Polytechnic University, Pomona, CA (United States)]. E-mail: aaurilia@csupomona.edu

    2000-01-01

    This paper suggests a new way of computing the path integral for simple quantum mechanical systems. The new algorithm originated from previous research in string theory. However, its essential simplicity is best illustrated in the case of a free non relativistic particle, discussed here, and can be appreciated by most students taking an introductory course in quantum mechanics. Indeed, the emphasis is on the role played by the entire family of classical trajectories in terms of which the path integral is computed exactly using a functional representation of the Dirac delta distribution. We argue that the new algorithm leads to a deeper insight into the connection between classical and quantum systems, especially those encountered in high-energy physics. (author)

  11. An experimental study of light scattering by large, irregular particles

    Science.gov (United States)

    Mcguire, Audrey F.; Hapke, Bruce W.

    1995-01-01

    The intensity and polarization of light scattered by a variety of types of artificial partices large compared to the wavelength were measured as a function of phase angle. Shape, surface roughness, absorption coefficient, and internal scattering coefficient were varied systematically and their effects studied. Scattering by clear, smooth-surfaced spheres is in quantitative agreement with the predictions of the geometrical optics (ray theory) approximation to physical optics (Mie theory). The phase functions of almost all of the particles measured have both forward and backward scattering lobes. A two-parameter, double Henyey-Greenstein function generally provides reasonably good descriptions of the data, while keeping the number of free parameters to the minimum necessary. On a double Henyey- Greenstein parameter plot all of the particles fall into an L-shaped area of restricted size in which the location is characteristic of the particle type. Formalisms based on the equivalent slab model are also given for estimating the scattering efficiency of a large, irregular particle. For most dielectric particles the transmitted, forward scattered light is partially negatively polarized. It is this component that is respopnsible for the well-known maximum in the polarization curves of planetary regoliths at phase angles around 100 deg. For phase angles between about 30 deg and 70 deg the internally scattered light is found to be randomly polarized in the particles studied here, so that the only contribution to the second component of the Stokes vector is by Fresnel reflection from the particle surface. If this empirical result is general, measurement of the second Stokes vector of the light scattered from a regolith at these angles may provide a method of remotely measuring the mean refractive index.

  12. How elementary paticles are discovered. From the cyclotron to the LHC - an expedition through the world of the particle accelerators; Wie man Elementarteilchen entdeckt. Vom Zyklotron zum LHC - ein Streifzug durch die Welt der Teilchenbeschleuniger

    Energy Technology Data Exchange (ETDEWEB)

    Freytag, Carl; Osterhage, Wolfgang W.

    2016-07-01

    This book explains the physical foundations and the technology of the elementary-particle research and describes the particle accelerators, the detector, and their concerted acting. On some milestones of the research - from the production of transuranium elements via the discovery of exotic mesons until the Higgs particle - the way from theory via the experiment to the research result is shown.

  13. Elementary particle physics and high energy phenomena. Progress report for FY93

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z{sup 0} with the SLD detector; fixed-target K-decay experiments; the R&D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs.

  14. Elementary particle physics and high energy phenomena. [Dept. of Physics, Univ. of Colorado, Boulder, Colorado

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; De Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    Experimental and theoretical high-energy physics programs at the University of Colorado are reported. Areas of concentration include the following: study of the properties of the Z[sup 0] with the SLD detector; fixed-target K-decay experiments; the R D program for the muon system: the SDC detector; high-energy photoproduction of states containing heavy quarks; electron--positron physics with the CLEO II detector at CESR; lattice QCD; and spin models and dynamically triangulated random surfaces. 24 figs., 2 tabs., 117 refs.

  15. Research in elementary particle physics. [Dept. of Physics and Astronomy, Louisiana State Univ,. Baton Rouge, Louisiana

    Energy Technology Data Exchange (ETDEWEB)

    Chan, L.H; Haymaker, R.; Imlay, R.; McNeil, R.; Metcalf, W.; Svoboda, R.

    1992-01-01

    Theoretical work on effective action expansion on an effective low; energy theory of hadron, dynamical symmetry breaking, and lattice gauge theories is described. The high-energy experimental group at Louisiana State University has analyzed data on a neutrino oscillation experiment at LAMPF. Preparations for the LSND neutrino experiment have stated. IMB data have also been analyzed. On the ZEUS electron n-proton colliding bean experiment, the production of the barrel calorimeter has been completed. Several modules of the calorimeter have been tested at Fermilab, and preparations for data taking are underway.

  16. Research in elementary particle physics. Progress report, March 1, 1991--February 29, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Chan, L.H; Haymaker, R.; Imlay, R.; McNeil, R.; Metcalf, W.; Svoboda, R.

    1992-12-31

    Theoretical work on effective action expansion on an effective low; energy theory of hadron, dynamical symmetry breaking, and lattice gauge theories is described. The high-energy experimental group at Louisiana State University has analyzed data on a neutrino oscillation experiment at LAMPF. Preparations for the LSND neutrino experiment have stated. IMB data have also been analyzed. On the ZEUS electron n-proton colliding bean experiment, the production of the barrel calorimeter has been completed. Several modules of the calorimeter have been tested at Fermilab, and preparations for data taking are underway.

  17. Research in elementary particle physics. Progress report, March 1, 1992--February 28, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Lai-Him; Haymaker, R.; Imlay, R.; McNeil, R.; Metcalf, W.; Svoboda, R.

    1992-10-01

    We describe theoretical work on effective action expansion on an effective low energy theory of hadrons and lattice gauge theories. The high energy experimental group at Louisiana State University has analyzed data on a neutrino oscillation experiment at LAMPF. The LSND neutrino experiment is preparing to take data in 1993. IMB data has been analyzed. Preparations for a beam test at KEK for IMB are in progress. Dumand is preparing to test one string of the detector early next summer. The ZEUS electron proton colliding beam experiment has started to take data. Early results have been reported.

  18. A New Search for Elementary Particles with Fractional Electric Charge Using an Improved Millikan Technique

    Energy Technology Data Exchange (ETDEWEB)

    Mar, Nancy

    2003-08-18

    The authors have devised and demonstrated the successful operation of a low cost, high mass throughput technique capable of performing bulk matter searches for fractionally charged particles based on an improved Millikan liquid drop method. The method uses a stroboscopic lamp and a CCD video camera to image the trajectories of silicone oil drops falling through air in the presence of a vertical, alternating electric field. The images of the trajectories are computer processed in real time, the electric charge on a drop being measured with an rms error of 0.025 of an electron charge. This error is dominated by Brownian motion. In the first use of this method, they have looked at 5,974,941 drops and found no evidence for fractional charges in 1.07 mg of oil. With 95% confidence, the concentration of isolated quarks with {+-} 1/3e or {+-} 2/3e in silicone oil is less than one per 2.14 x 10{sup 20} nucleons.

  19. A New Search for Elementary Particles with Fractional Electric Charge Using an Improved Millikan Technique

    CERN Document Server

    Mar, N

    2003-01-01

    The have devised and demonstrated the successful operation of a low cost, high mass throughput technique capable of performing bulk matter searches for fractionally charged particles based on an improved Millikan liquid drop method. The method uses a stroboscopic lamp and a CCD video camera to image the trajectories of silicone oil drops falling through air in the presence of a vertical, alternating electric field. The images of the trajectories are computer processed in real time, the electric charge on a drop being measured with an rms error of 0.025 of an electron charge. This error is dominated by Brownian motion. In the first use of this method, they have looked at 5,974,941 drops and found no evidence for fractional charges in 1.07 mg of oil. With 95% confidence, the concentration of isolated quarks with +- 1/3e or +- 2/3e in silicone oil is less than one per 2.14 x 10 sup 2 sup 0 nucleons.

  20. Experimental study of sediment particle diffusion on a granular bed.

    Science.gov (United States)

    Antico, Federica; Sanches, Pedro; Fent, Ilaria; Ferreira, Rui M. L.

    2016-04-01

    Particle diffusion in a cohesionless granular bed, hydraulically fully rough, subjected to a steady-uniform turbulent open-channel flow is investigated. Experiments were carried out under conditions of weak bedload transport in a 12.5 m long and 40.5 cm wide glass-sided flume recirculating water and sediment through independent circuits at the Laboratory of Hydraulics and Environment of Instituto Superior Técnico, Lisbon. The flume bed was divided in two reaches: a fixed reach comprising 1.5 m of large boulders, followed by 3.0 m of smooth bottom (PVC) and 2.5 m of one layer glued 5.0 mm diameter spherical glass beads; a mobile reach 4.0 m long and 2.5 cm deep filled with 5.0 mm diameter glass packed beads. Particle velocities were obtained introducing 5.0 mm diameter white-coated beads in the flow. Particle motion was registered from above using a high-speed camera AVT Bonito CL-400 with resolution set to 2320 x 1000 px2and frame rate of 170 fps. The field of view recorded was 77.0 cm long and 38.0 cm wide, covering almost all the width of the flume. Image processing allowed detecting and locating the centre of mass of the particles with sub-pixel accuracy. Particle trajectories were reconstructed by tracking the beads in the images; particle velocities were obtained as bead displacement over time interval between two consecutive frames (1/170 s). The computation of lagrangian statistics of particle velocities for a Shields parameter θ=0.014, Froude number Fr=0.756, boundary Reynolds number Re*=182.9 and run duration of 20 min (during which 1218 particle trajectories were collected) provided information about particle diffusion within the local and intermediate range of temporal and space scales. Mean particle velocities, second, third and fourth order moments were obtained for both longitudinal and transverse velocity components. A relatively large ballistic range, approximately two particle diameters, was observed, mainly due to the simple bed topography of

  1. Elementary particle interactions. Progress report, October 1, 1994--September 30, 1995

    Energy Technology Data Exchange (ETDEWEB)

    Bugg, W.M.; Condo, G.T.; Handler, T.; Hart, E.L.; Read, K.; Siopsis, G.; Ward, B.F.L.

    1995-10-01

    This year has been a busy and demanding one with completion of a long SLD run, much progress on light quark states from E-687 resulting in strong evidence for two new states, observation in E-144 of non-linear Compton scattering (multiphoton absorption by electrons) up to N-4 and initial evidence for e{sup +}e{sup {minus}} pair production in Compton process. The authors have also made considerable progress toward preparation for a n-{bar n} oscillation experiment and have carried out experimental studies of quartz fiber calorimetry for SLD polarimeter and forward calorimeter for CMS and LHC including a thorough set of gamma ray and neutron radiation damage studies on quartz fiber. Two graduate students received their Ph.D.s this year, Kathy Danyo Blackett on data from Fermilab E-687 and Sharon White on SLD radiative Bhabha scattering.

  2. Research on elementary particle physics. Annual progress report, January 1, 1992--October 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Holloway, L.E.; O`Halloran, T.A.

    1992-05-01

    This report describes the activities of the University of Illinois Experimental High Energy Physics Group. The physicists in the University of Illinois High Energy Physics Group are engaged in a wide variety of experiments at current and future accelerator laboratories. These include: (1) The CDF experiment at the Fermilab Tevetron p{bar p} collider. (2) Design and developmental work for the SDC group at SSCL. (3) Experiments at the wide band photon beam at Fermilab. (4) The SLD experiment at SLAC and design studies for a {tau}-charm factor. (5) CP violation experiments at Fermilab. (6) The HiRes cosmic ray experiment at Dugway Proving Grounds, Utah. (7) Computational facilities. (8) Electronics systems development.

  3. Research in experimental elementary particle physics. A proposal to the U.S. Department of Energy

    Energy Technology Data Exchange (ETDEWEB)

    Andrew P. White; Kaushik De; Paul A. Draper; Ransom Stephens

    1995-04-13

    We report on the activities of the High Energy Physics Group at the University of Texas at Arlington for the period 1994-95. We propose the continuation of the research program for 1996-98 with strong participation in the detector upgrade and physics analysis work for the D0 Experiment at Fermilab, prototyping and pre-production studies for the muon and calorimeter systems for the ATLAS Experiment at CERN, and detector development and simulation studies for the PP2PP Experiment at Brookhaven.

  4. Experimental Exploration of Electrostatic Charge on Particle Pair Relative Velocity in Homogeneous and Isotropic Turbulence

    Science.gov (United States)

    Hammond, Adam; Dou, Zhongwang; Tripathi, Anjan; Liang, Zach; Meng, Hui

    2015-11-01

    Study of droplet collision and cloud formation should consider the effects of both turbulence and electrostatic charge on particle dynamics. We present the first experimental observation of radial relative velocity (RV) of charged particles in homogeneous and isotropic turbulence (HIT). Charges on particles were generated through triboelectric effect between the inner wall of the chamber and the particles. To measure charge distribution, a particle-laden head-on impinging flow mimicking our HIT chamber conditions was built and holographic particle tracking was applied to quantify particle charges by measuring their displacements in an electric field. Particles were observed to have opposite charges. Next, in our HIT chamber, we measured particle RV by a novel 4-frame particle tracking velocimetry technique with and without charges on particles, wherein charges were neutralized by coating the interior of the HIT chamber with conductive carbon paint. We compared RV under the same turbulence conditions between charged particles and neutral particles and observed that when particles were oppositely charged, their mean inward RV increased at small separation distances. This result is consistent with recent theory and simulations (Lu and Shaw, Physics of Fluids, 2015). This work was supported by the National Science Foundation through a Collaborative Research Grant CBET-0967407.

  5. Experimental Effects on IR Reflectance Spectra: Particle Size and Morphology

    Energy Technology Data Exchange (ETDEWEB)

    Beiswenger, Toya N.; Myers, Tanya L.; Brauer, Carolyn S.; Su, Yin-Fong; Blake, Thomas A.; Ertel, Alyssa B.; Tonkyn, Russell G.; Szecsody, James E.; Johnson, Timothy J.; Smith, Milton; Lanker, Cory

    2016-05-23

    For geologic and extraterrestrial samples it is known that both particle size and morphology can have strong effects on the species’ infrared reflectance spectra. Due to such effects, the reflectance spectra cannot be predicted from the absorption coefficients alone. This is because reflectance is both a surface as well as a bulk phenomenon, incorporating both dispersion as well as absorption effects. The same spectral features can even be observed as either a maximum or minimum. The complex effects depend on particle size and preparation, as well as the relative amplitudes of the optical constants n and k, i.e. the real and imaginary components of the complex refractive index. While somewhat oversimplified, upward-going amplitude in the reflectance spectrum usually result from surface scattering, i.e. rays that have been reflected from the surface without penetration, whereas downward-going peaks are due to either absorption or volume scattering, i.e. rays that have penetrated or refracted into the sample interior and are not reflected. While the effects are well known, we report seminal measurements of reflectance along with quantified particle size of the samples, the sizing obtained from optical microscopy measurements. The size measurements are correlated with the reflectance spectra in the 1.3 – 16 micron range for various bulk materials that have a combination of strong and weak absorption bands in order to understand the effects on the spectral features as a function of the mean grain size of the sample. We report results for both sodium sulfate Na2SO4 as well as ammonium sulfate (NH4)2SO4; the optical constants have been measured for (NH4)2SO4. To go a step further from the field to the laboratory we explore our understanding of particle size effects on reflectance spectra in the field using standoff detection. This has helped identify weaknesses and strengths in detection using standoff distances of up 160 meters away from the Target. The studies have

  6. An experimental study of particle-driven gravity currents on steep slopes with entrainment of particles

    Directory of Open Access Journals (Sweden)

    M. Rastello

    2002-01-01

    Full Text Available Results of laboratory experiments are presented in which a finite suspension of sawdust particles was released instantaneously into a rectangular channel immersed in a water tank. Two kinds of gravity currents were studied: currents with or without entrainment of particles from the bed. Experiments were repeated for two slopes: 30° and 45°. We observed that the velocity of the front was significantly in-creased as particle entrainment occurred. In addition, our experiments showed that the front kept a quasi-constant velocity for both runs. This might suggest that the flow regime corresponded to the "slumping regime" or "adjustment phase" described earlier by Huppert and Simpson (1980.

  7. FInal Report: DE-FG02-04ER41310 "Elementary Particle Physics"

    Energy Technology Data Exchange (ETDEWEB)

    Izen, Joseph M. [University of Texas at Dallas; Ishak-Boushaki, Mustapha [University of Texas at Dallas

    2013-10-18

    vATLAS and the LHC are delivering on the promise of discovery physics at the high energy frontier. Using 4.8 fb^-1 of 2011 √s=7 TeV data and the first 5.8 fb?1 of 2012 √s=8 TeV data, ATLAS published the observation of a new particle with a mass of 126 GeV with a significance of 5.9σ that is compatible with a Standard Model (SM) Higgs. The LHC is outperforming intial projections for the 2012 run, and ATLAS is on track to integrate ~20 fb^(-1) of proton-proton collisions in 2012 before Long Shutdown 1 (LS1) begins in Spring 2013. University of Texas at Dallas (UTD) physicists will complete work on two ATLAS analyses this fall. The first is the search for the gauge bosons of a hypothesized dark sector. For 2011 data, UTD is responsible for the ?dark photon?search in the electron-jet channel, and we are looking forward to an expanded leadership role in the dark photon search using the full 2012 data set. Our second analysis interest is the study of X/Y/Z exotic states having cc content, which builds on our experience in this field from the BABAR experiment After completing a measurement of the Xc(3872) production cross section this fall, we will search for evidence of the Z(4430)+ which is reported by Belle but not confirmed by BABAR. The UTD group has played a strong role in ATLAS operations, with group members serving as Pixel Run Coordinator, ATLAS Shift Leader, and Pixel/Inner Detector Shifter. For most of the current 3-year funding cycle, a group member coordinated the development of the Pixel DAQ code, and another continues to build and maintain the data quality monitoring (DQM) application that is used by the Inner Detector control room shifter. Additionally, members of our group take Pixel on-call expert shifts for DQM and DAQ. We led an optoboard lifetime study to assess concerns of premature on-detector VCSEL failure using the Pixel working prototype detector at CERN. Physicists based at UTD participated through Pixel Offline DQM and ATLAS Distributed

  8. Experimental evidence links volcanic particle characteristics to pyroclastic flow hazard

    Science.gov (United States)

    Dellino, Pierfrancesco; Büttner, Ralf; Dioguardi, Fabio; Doronzo, Domenico M.; La Volpe, Luigi; Mele, Daniela; Sonder, Ingo; Sulpizio, Roberto; Zimanowski, Bernd

    2010-06-01

    Pyroclastic flows represent the most hazardous events of explosive volcanism, one striking example being the famous historical eruption of Vesuvius that destroyed Pompeii (AD 79). Much of our knowledge of the mechanics of pyroclastic flows comes from theoretical models and numerical simulations. Valuable data are also stored in the geological record of past eruptions, including the particles contained in pyroclastic deposits, but the deposit characteristics are rarely used for quantifying the destructive potential of pyroclastic flows. By means of experiments, we validate a model that is based on data from pyroclastic deposits. The model allows the reconstruction of the current's fluid-dynamic behaviour. Model results are consistent with measured values of dynamic pressure in the experiments, and allow the quantification of the damage potential of pyroclastic flows.

  9. Experimental particle physics at the University of Pittsburgh

    Energy Technology Data Exchange (ETDEWEB)

    Engels, E. Jr.; Perera, U.; Shepard, P.F.; Thompson, J.A.

    1992-04-01

    During the past year Task A completed the HELIOS single and pair electron analyses and found no anomalous production or multiplicity dependence. The HELIOS electron-muon pair analysis continued in its search for lepton physics beyond the expected charm yields. Data taking began at the CMD2 detector at Novosibirsk. Measurements of the U. V. reflectivity and photomultiplier tests for the first Cerenkov counter to be used in the E865 experiment at BNL were carried out, along with the development of a general ray-tracing code. The design of the Cerenkov counter for E865 along with development of light mirror fabrication techniques were a major part of the Task A program. The principal efforts of Task B, the Fermilab program, have been the completion of the analysis of the 1987--1988 data with resulting publications, completion of the 1990--1991 data run, and the beginning of the analysis of the 1990--1991 data. In addition, the Task B group is taking a leadership role in developing a proposal to Fermilab for the upgrade of the CDF silicon vertex detector in preparation for the 1995 data run. This proposal is to be presented to the laboratory management in time for the fall Fermilab Program Advisory Committee meeting. Task C has recently submitted results of its fractionally charged particle searches, placing new upper limits on the abundance of naturally-occurring fractionally-charged particles in various materials. This group has recently been approved by the Brookhaven management for an exposure of their p-i-n diodes in a high intensity proton beam. This measurement, along with its subsequent analysis, will complete the program.

  10. Rapid transport of nano-particles having a fractional elementary charge on average in capacitively-coupled rf discharges by amplitude-modulating discharge voltage.

    Science.gov (United States)

    Shiratani, Masaharu; Koga, Kazunori; Iwashita, Shinya; Nunomura, Syota

    2008-01-01

    We have observed transport of nano-particles having, on average, a fractional elementary charge in single pulse and double pulse capacitively-coupled rf discharges both without and with an Amplitude Modulation (AM) of the discharge voltage, using a two-dimensional laser-light scattering method. Rapid transport of nano-particles towards the grounded electrode is realized using rf discharges with AM. Two important parameters for the rapid transport of nano-particles are the discharge voltage and the period of AM. An important key of the rapid transport is fast redistribution of ion current over the whole discharge region; that is, fast change of spatial distribution of forces exerted on nano-particles. The longer period of the modulation is needed for rapid transport for the larger nano-particles. The higher discharge voltage of the modulation is needed for rapid transport of nano-particles having a smaller mean charge. Local perturbation of electric potential using a probe does not bring about global rapid transport of nano-particles, whereas it leads to their local transport near the probe.

  11. Discerning elementary particles

    NARCIS (Netherlands)

    Muller, F.A.; Seevinck, M.P.

    2009-01-01

    We maximally extend the quantum‐mechanical results of Muller and Saunders (2008) establishing the ‘weak discernibility’ of an arbitrary number of similar fermions in finite‐dimensional Hilbert spaces. This confutes the currently dominant view that (A) the quantum‐mechanical description of similar

  12. Experimental particle acceleration by water evaporation induced by shock waves

    Science.gov (United States)

    Scolamacchia, T.; Alatorre Ibarguengoitia, M.; Scheu, B.; Dingwell, D. B.; Cimarelli, C.

    2010-12-01

    Shock waves are commonly generated during volcanic eruptions. They induce sudden changes in pressure and temperature causing phase changes. Nevertheless, their effects on flowfield properties are not well understood. Here we investigate the role of gas expansion generated by shock wave propagation in the acceleration of ash particles. We used a shock tube facility consisting of a high-pressure (HP) steel autoclave (450 mm long, 28 mm in internal diameter), pressurized with Ar gas, and a low-pressure tank at atmospheric conditions (LP). A copper diaphragm separated the HP autoclave from a 180 mm tube (PVC or acrylic glass) at ambient P, with the same internal diameter of the HP reservoir. Around the tube, a 30 cm-high acrylic glass cylinder, with the same section of the LP tank (40 cm), allowed the observation of the processes occurring downstream from the nozzle throat, and was large enough to act as an unconfined volume in which the initial diffracting shock and gas jet expand. All experiments were performed at Pres/Pamb ratios of 150:1. Two ambient conditions were used: dry air and air saturated with steam. Carbon fibers and glass spheres in a size range between 150 and 210 μm, were placed on a metal wire at the exit of the PVC tube. The sudden decompression of the Ar gas, due to the failure of the diaphragm, generated an initial air shock wave. A high-speed camera recorded the processes between the first 100 μsec and several ms after the diaphragm failure at frame rates ranging between 30,000 and 50,000 fps. In the experiments with ambient air saturated with steam, the high-speed camera allowed to visualize the condensation front associated with the initial air shock; a maximum velocity of 788 m/s was recorded, which decreases to 524 m/s at distance of 0.5 ±0.2 cm, 1.1 ms after the diaphragm rupture. The condensation front preceded the Ar jet front exhausting from the reservoir, by 0.2-0.5 ms. In all experiments particles velocities following the initial

  13. An experimental study of particle-bubble interaction and attachment in flotation

    KAUST Repository

    Sanchez Yanez, Aaron

    2017-05-01

    The particle-bubble interaction is found in industrial applications with the purpose of selective separation of materials especially in the mining industry. The separation is achieved with the use of bubbles that collect particles depending on their hydrophobicity. There are few experimental studies involving a single interaction between a bubble and a particle. The purpose of this work is to understand this interaction by the study of a single bubble interacting with a single particle. Experiments were conducted using ultra-pure water, glass particles and air bubbles. Single interactions of particles with bubbles were observed using two high speed cameras. The cameras were placed perpendicular to each other allowing to reconstruct the three-dimensional position of the particle, the bubble and the particle-bubble aggregate. A single size of particle was used varying the size for the bubbles. It was found that the attachment of a particle to a bubble depends on its degree of hydrophobicity and on the relative position of the particle and the bubble before they encounter.

  14. Smoking experimentation among elementary school students in China: influences from peers, families, and the school environment.

    Directory of Open Access Journals (Sweden)

    Cheng Huang

    Full Text Available The aim of this study was to investigate experimentation with smoking among primary school students in China. Data were acquired from a recent survey of 4,073 students in grades 4 to 6 (ages 9-12 in 11 primary schools of Ningbo City. The questions were adapted from the Global Youth Tobacco Survey (GYTS. Results suggest that although the Chinese Ministry of Education (MOE encourages smoke-free schools, experimentation with cigarettes remains a serious problem among primary school students in China. Peers, family members, and the school environment play important roles in influencing smoking experimentation among students. Having a friend who smoked, seeing a family member smoke, and observing a teacher smoking on campus predicted a higher risk of experimentation with smoking; the exposure to anti-tobacco materials at school predicted a lower risk of experimentation with smoking. The evidence suggests that public health practitioners and policymakers should seek to ensure the implementation of smoke-free policies and that intervention should target young people, families, and communities to curb the commencement of smoking among children and adolescents in China.

  15. Simulated statistics of polydisperse sedimenting inertial particles in a turbulent flow under experimental conditions

    Science.gov (United States)

    Wang, Lian-Ping; Parishani, Hossein; Rosa, Bogdan; Bateson, Colin; Aliseda, Alberto; Grabowski, Wojciech

    2009-11-01

    In recent years, point-particle based or hybrid direct numerical simulations (DNS) have increasingly been used to study pair statistics of inertial particles relevant to turbulent collision of cloud droplets. Equivalent experiment data are rare but are slowly becoming available. In this talk, we will discuss simulated statistics of sedimenting inertial particles under conditions similar to our parallel wind-tunnel experiment (to be reported here by Bateson et al.). The key parameters to be matched are flow Reynolds number, dissipation rate, particle Stokes number, and dimensionless settling velocity. A prescribed droplet size distribution will be used in the simulation to reproduce the polydisperse condition in the experiment. High-resolution DNS will be used to maximize the computational domain size. Single-particle and particle-pair statistics (e.g., fluctuation velocities, radial distribution function, relative velocity statistics) will be compared to the experimental data. Statistics obtained from lower dimensions will be linked to statistics in three dimensions.

  16. Experimental investigation of evaporation enhancement for water droplet containing solid particles in flaming combustion area

    Directory of Open Access Journals (Sweden)

    Glushkov Dmitrii O.

    2016-01-01

    Full Text Available The experimental study of integral characteristics of extinguishing liquid (water droplet evaporation in flaming combustion area has been held. Optical methods of two-phase and heterogeneous mixtures diagnostics (“Particle Image Velocimetry” and “Interferometric Particle Imaging” have been used for heat and mass transfer process investigation. It was established that small-size solid particles (for example, carbon particles in droplet structure can enhance water evaporation in flame area. It was shown that the rate of evaporation process depends on concentration and sizes of solid particles in a water droplet. The correlations have been determined between the sizes of solid particles and water droplets for maximum efficiency of fire extinguishing. The physical aspects of the problem have been discussed.

  17. Experimental Investigation of the Matching Relationship between Asphalt Particle and Reservoir Pore in Profile Control Process

    Directory of Open Access Journals (Sweden)

    Chengfeng Ren

    2016-01-01

    Full Text Available Modified sulfonated asphalt particles have a bright application prospect of the profile control of thick reservoirs due to the low cost, extensive sources, and good compatibility with reservoir. Nevertheless, the matching relationship between asphalt particles and reservoir pore has seldom been investigated till now. Oversized particles always block the near-wellbore area, which causes high injection pressures, while undersized particles cannot plug large pores. We designed a core for this experiment which has a high permeability zone in front of it and many pressure measuring points. We could quantitatively assess the matching relationship by measuring the on-way resistance coefficient, residual resistance factor, and relative change of permeability of man-made cores after injecting asphalt. Experimental results indicate that asphalt particles with sizes of 0.02 mm, 0.02–0.06 mm, and 0.08–0.1 mm match with reservoir permeability of 500 mD, 1000 mD, and 2000 mD, respectively. Undersized or oversized particles can reduce the conformance control effect, and the concentration of asphalt particles in the injectant can limit their migration ability. When the concentration of asphalt particles increases to 3000 mg/L, accumulations of asphalt particles can be caused in the formation, in which a scheme with asphalt particles alternative water injection is proposed to avoid the accumulation.

  18. Experimental Searches for the Axion and Axion-like Particles

    CERN Document Server

    Graham, Peter W; Lamoreaux, Steven K; Lindner, Axel; van Bibber, Karl A

    2016-01-01

    Four decades after its prediction, the axion remains the most compelling solution to the Strong-CP problem and a well-motivated dark matter candidate, inspiring a host of elegant and ultrasensitive experiments based on axion-photon mixing. This report reviews the experimental situation on several fronts. The microwave cavity experiment is making excellent progress in the search for dark matter axions in the microelectronvolt range and may be plausibly extended up to 100 mu eV. Within the past several years however, it has been realized that axions are pervasive throughout string theories, but with masses that fall naturally in the nanoelectronvolt range, for which a NMR-based search is under development. Searches for axions emitted from the Sun's burning core, and purely laboratory experiments based on photon regeneration have both made great strides in recent years, with ambitious projects proposed for the coming decade. Each of these campaigns has pushed the state of the art in technology, enabling large ga...

  19. Experimental Study of Inertial Particle-Pair Relative Velocity in Isotropic Turbulence

    Science.gov (United States)

    Dou, Zhongwang

    have systematically investigated the effects of Reynolds number and Stokes number (St) on particle-pair RV using the planar 4F-PTV technique in the HIT chamber. Two experiments were performed: varying Rlambda between 246 and 357 at six fixed St values, and varying St between 0.02 and 4.63 at five fixed Rlambda values. Measured mean inward particle-pair RV as a function of separation distance r were compared against DNS under closely matched conditions. At all experimental conditions, an excellent agreement was achieved except when particle separation distance r was consistently higher, possibly due to particle polydispersity and finite laser thickness in experiment. Through these three steps, we found that, at any fixed St, the mean inward particle-pair RV, was essentially independent of Rlambda, echoing DNS findings by Ireland et al. (2016a). At any fixed R lambda, increased with St at small r, showing dominance of the path-history effect in the dissipation range when St ≥ O(1), but decreased with St at large r, indicating dominance of the inertial filtering effect. What I provided here are the first experimental observation of the independence of mean inward particle-pair RV on Reynolds number, and the first experimental observation of these two mechanisms on the mean inward particle-pair RV over a large range of particle separation distances.

  20. Damping Characterization of Friction Energy Dissipation for Particle Systems Based on Powder Mechanics and Experimental Verification

    Directory of Open Access Journals (Sweden)

    Wangqiang XIAO

    2014-04-01

    Full Text Available We established a friction energy dissipation model for particle damping based on powder mechanics. We investigated the influence of geometric features of the damper on damping characteristics; and the geometric feature studied was the depth and length of the rectangular particle container. The work done by the frictional force between the particle layer and the effect of particle filling rate on the vibration damping characteristics was also explored. We analyzed the friction energy dissipation model, and the relationship between the particle filling rate and the vibration damping. The experimental results show good agreement with the friction energy dissipation model, which verifies the proposed simulation prediction. The results have shown that the particle damping technology can greatly consume the structure kinetic energy, and the vibration reduction effect of particle damping depends mainly on the interaction of the particles near the top. A proper filling rate of particle systems can result in an optimal effect on vibration reduction, which will provide the engineering applications with the theoretical guidance and design criteria.

  1. No effect of hydroxyapatite particles in phagocytosable sizes on implant fixation: an experimental study in dogs

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Bendix, K

    2005-01-01

    on the mechanical fixation and gap healing around experimental HA implants. Nonloaded implants (n = 30) were inserted bilaterally into the proximal tibia of 15 dogs with a 2-mm gap to the bone. The peri-implant gap was either (1) empty (n = 6) or filled with (2) hyaluronic acid (n = 8), (3) hyaluronic acid and HA...... particles (n = 8), or (4) hyaluronic acid and PE particles (n = 8). After 4 weeks, the animals were killed. The implant interface was evaluated by pushout testing until failure and by histomorphometry. Both HA and PE particles were found to be phagocytosed by macrophage-like cells in the interfacial tissue...

  2. Nuclei, hadrons, and elementary particles. A short introduction. 2. ed.; Kerne, Hadronen und Elementarteilchen. Eine kurze Einfuehrung

    Energy Technology Data Exchange (ETDEWEB)

    Bopp, Fritz W. [Siegen Univ. (Germany)

    2015-07-01

    One of the most important developments in physics is the increasing understanding of subatomic phenomena. The subatomic physics belong today to the canonical parts of a study of physics. In many universities therefore for this an introductory course is offered. The first edition arose from a script for such courses. The subatomic physic has since the first edition distinctly changed. Because I keep the concept of the book still as usual for good I have decided for a new edition. Many textbooks and courses in nuclear and particle physics try to motivate students in a certain direction. This is surely appropriate in an advanced state of a study. In the bachelor range this can lead to a not suffiecently wide development, and the book tries to counteract to this. How physical phenomena are to be describe depends on each energy scale. In the book for each scale a concise introduction is given to the occasionally required description. By this way regularity is reached, and it is avoided to give to the fields wrong priorities. The list of the meanwhile necessary changes is long, and I want to cite here only some topics. The chapter about high-energy accelerators is antiquated, many of the accelerators planned at that time were not realize. The realized new accelerators open new regions in hadron and heavy-ion physics, and maybe new observations and concepts are to be cited for this. How quarks bind to hadrons is today better understood and requires an extensive discussion. To be mentioned is also that the application range of perturbative quantum chromodynamics could be extended in different directions by new methods. The essential cause of the new edition is the experimental detection of the Higgs particle, which must now be treated extensively. A careful revision of the new edition led to a very large number of corrections and smaller improvements.

  3. Innovative experimental particle physics through technological advances: Past, present and future

    Energy Technology Data Exchange (ETDEWEB)

    Cheung, Harry W.K.; /Fermilab

    2005-01-01

    This mini-course gives an introduction to the techniques used in experimental particle physics with an emphasis on the impact of technological advances. The basic detector types and particle accelerator facilities will be briefly covered with examples of their use and with comparisons. The mini-course ends with what can be expected in the near future from current technology advances. The mini-course is intended for graduate students and post-docs and as an introduction to experimental techniques for theorists.

  4. Experimental Investigation of the Effect of Particle Shape on Frictional Pressure drop in Particulate Debris Bed

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Kim, Eun Ho; Park, Hyun Sun [POSTECH, Pohang (Korea, Republic of)

    2014-10-15

    To ensure the long-term cooling of corium in the reactor cavity, it is important to ensure the coolant ingression into the internally heat generated corium debris bed which is governed by pressure drop in porous media. For this reason, it is necessary to understand pressure drop mechanisms in porous bed to verify the feasibility of water penetration into particulate debris bed. According to the previous investigations on molten fuel-coolant interaction (FCI) experiments, it was found that quenched particulate debris bed was composed of irregular shape particles. Therefore, empirical or semiempirical models based on the Ergun equation (Ergun, 1952) for single-phase flow in porous media composed of single sized spherical particle were developed to consider the effect of particle shape on frictional pressure drop by means of adding a shape factor or modifying the Ergun constants etc. (Leva, 1959, Handley and Heggs, 1968, Macdonald, 1979, Foumeny et al., 1996). An experimental investigate on single-phase frictional pressure drop of water in packed bed was conducted in the transparent cylindrical test section with the inner diameter of 100 mm and the height of 700 mm to study the effect of particle shape on frictional pressure drop in porous media. This paper reports the experimental data for spherical particles with the diameter of 2 mm and 5 mm and cylindrical particles with ED of 2 mm and 5 mm. And also, the experimental data compared with the models to predict frictional pressure drop in particulate bed. The conclusions are summarized as follows. As a result of the experiment to measure frictional pressure drop in particulate bed composed of cylindrical particles the models predict the experimental data well within 22.11 % except the Handley and Heggs model when ED is applied to the models.

  5. Recent experimental advances for understanding bubble-particle attachment in flotation.

    Science.gov (United States)

    Xing, Yaowen; Gui, Xiahui; Pan, Lei; Pinchasik, Bat-El; Cao, Yijun; Liu, Jiongtian; Kappl, Michael; Butt, Hans-Jürgen

    2017-08-01

    Bubble-particle interaction is of great theoretical and practical importance in flotation. Significant progress has been achieved over the past years and the process of bubble-particle collision is reasonably well understood. This, however, is not the case for bubble-particle attachment leading to three-phase contact line formation due to the difficulty in both theoretical analysis and experimental verification. For attachment, surface forces play a major role. They control the thinning and rupture of the liquid film between the bubble and the particle. The coupling between force, bubble deformation and film drainage is critical to understand the underlying mechanism responsible for bubble-particle attachment. In this review we first discuss the advances in macroscopic experimental methods for characterizing bubble-particle attachment such as induction timer and high speed visualization. Then we focus on advances in measuring the force and drainage of thin liquid films between an air bubble and a solid surface at a nanometer scale. Advances, limits, challenges, and future research opportunities are discussed. By combining atomic force microscopy and reflection interference contrast microscopy, the force, bubble deformation, and liquid film drainage can be measured simultaneously. The simultaneous measurement of the interaction force and the spatiotemporal evolution of the confined liquid film hold great promise to shed new light on flotation. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. An Experimental Study on the Learning Outcome of Teaching Elementary Level Children using Lego Mindstorms EV3 Robotics Education Kit

    OpenAIRE

    Chaudhary, Vidushi; Agrawal, Vishnu; Sureka, Ashish

    2016-01-01

    Skills like computational thinking, problem solving, handling complexity, team-work and project management are essential for future careers and needs to be taught to students at the elementary level itself. Computer programming knowledge and skills, experiencing technology and conducting science and engineering experiments are also important for students at elementary level. However, teaching such skills effectively through active learning can be challenging for educators. In this paper, we p...

  7. Experimental study of the viscosity of suspensions: effect of solid fraction, particle size and suspending liquid

    NARCIS (Netherlands)

    Konijn, B.J.; Sanderink, O.B.J.; Kruyt, Nicolaas P.

    2014-01-01

    The behaviour of nearly neutrally-buoyant suspensions has been studied experimentally, using a concentric-cylinder rheometer. The effect on the suspension viscosity of: (i) solid fraction, (ii) diameter of the solid, spherical particles, (iii) viscosity of the suspending liquid, and (iv) shear rate

  8. The Future of Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Bjorken, James

    2000-06-15

    After a very brief review of twentieth century elementary particle physics, prospects for the next century are discussed. First and most important are technological limits of opportunities; next, the future experimental program, and finally the status of the theory, in particular its limitations as well as its opportunities.

  9. Push hard, push fast: quasi-experimental study on the capacity of elementary schoolchildren to perform cardiopulmonary resuscitation.

    Science.gov (United States)

    Berthelot, Simon; Plourde, Miville; Bertrand, Isabelle; Bourassa, Amélie; Couture, Marie-Maud; Berger-Pelletier, Élyse; St-Onge, Maude; Leroux, Renaud; Le Sage, Natalie; Camden, Stéphanie

    2013-05-21

    The optimal age to begin CPR training is a matter of debate. This study aims to determine if elementary schoolchildren have the capacity to administer CPR efficiently. This quasi-experimental study took place in a Quebec City school. Eighty-two children 10 to 12 years old received a 6-hour CPR course based on the American Heart Association (AHA) Guidelines. A comparison group of 20 adults who had taken the same CPR course was recruited. After training, participants' performance was evaluated using a Skillreporter manikin. The primary outcome was depth of compressions. The secondary outcomes were compression rate, insufflation volume and adherence to the CPR sequence. Children's performance was primarily evaluated based on the 2005 AHA standards and secondarily compared to the adults' performance. Schoolchildren did not reach the lower thresholds for depth (28.1 +/- 5.9 vs 38 mm; one-sided p = 1.0). The volume of the recorded insufflations was sufficient (558.6 +/222.8 vs 500 ml; one-sided p = 0.02), but there were a significant number of unsuccessful insufflation attempts not captured by the Skillreporter. The children reached the minimal threshold for rate (113.9 +/-18.3 vs 90/min; one-sided p < 0.001). They did not perform as well as the adults regarding compression depth (p < 0.001), but were comparable for insufflation volume (p = 0.83) and CPR sequence. In this study, schoolchildren aged 10-12 years old did not achieve the standards for compression depth, but achieved adequate compression rate and CPR sequence. When attempts were successful at generating airflow in the Skillreporter, insufflation volume was also adequate.

  10. Fitting the elementary rate constants of the P-gp transporter network in the hMDR1-MDCK confluent cell monolayer using a particle swarm algorithm.

    Directory of Open Access Journals (Sweden)

    Deep Agnani

    Full Text Available P-glycoprotein, a human multidrug resistance transporter, has been extensively studied due to its importance to human health and disease. In order to understand transport kinetics via P-gp, confluent cell monolayers overexpressing P-gp are widely used. The purpose of this study is to obtain the mass action elementary rate constants for P-gp's transport and to functionally characterize members of P-gp's network, i.e., other transporters that transport P-gp substrates in hMDR1-MDCKII confluent cell monolayers and are essential to the net substrate flux. Transport of a range of concentrations of amprenavir, loperamide, quinidine and digoxin across the confluent monolayer of cells was measured in both directions, apical to basolateral and basolateral to apical. We developed a global optimization algorithm using the Particle Swarm method that can simultaneously fit all datasets to yield accurate and exhaustive fits of these elementary rate constants. The statistical sensitivity of the fitted values was determined by using 24 identical replicate fits, yielding simple averages and standard deviations for all of the kinetic parameters, including the efflux active P-gp surface density. Digoxin required additional basolateral and apical transporters, while loperamide required just a basolateral tranporter. The data were better fit by assuming bidirectional transporters, rather than active importers, suggesting that they are not MRP or active OATP transporters. The P-gp efflux rate constants for quinidine and digoxin were about 3-fold smaller than reported ATP hydrolysis rate constants from P-gp proteoliposomes. This suggests a roughly 3∶1 stoichiometry between ATP hydrolysis and P-gp transport for these two drugs. The fitted values of the elementary rate constants for these P-gp substrates support the hypotheses that the selective pressures on P-gp are to maintain a broad substrate range and to keep xenobiotics out of the cytosol, but not out of the

  11. Elementary cycles of time

    Directory of Open Access Journals (Sweden)

    Dolce Donatello

    2013-09-01

    Full Text Available Elementary particles, i.e. the basic constituents of nature, are characterized by quantum recurrences in time. The flow of time of every physical system can be therefore decomposed in elementary cycles of time. This allows us to enforce the local nature of relativistic time, yielding interesting unified descriptions of fundamental aspects of modern physics, as shown in recent publications. Every particle can be regarded as a reference clock with time resolution of the order of the Compton time particle, many orders of magnitude more accurate than the atomic clocks. Here we report basic implications about the resulting notion of time.

  12. Experimental evidence of independence of nuclear de-channeling length on the particle charge sign

    Energy Technology Data Exchange (ETDEWEB)

    Bagli, E.; Guidi, V.; Mazzolari, A.; Bandiera, L.; Germogli, G.; Sytov, A.I. [Universita di Ferrara, Dipartimento di Fisica e Scienze della Terra (Italy); INFN Sezione di Ferrara (Italy); De Salvador, D. [Universita di Padova, Dipartimento di Fisica e Astronomia, Padua (Italy); INFN Laboratori Nazionali di Legnaro (Italy); Berra, A.; Prest, M. [Universita dell' Insubria, Como (Italy); INFN Sezione di Milano Bicocca, Milan (Italy); Vallazza, E. [INFN Sezione di Trieste (Italy)

    2017-02-15

    Under coherent interactions, particles undergo correlated collisions with the crystal lattice and their motion result in confinement in the fields of atomic planes, i.e. particle channeling. Other than coherently interacting with the lattice, particles also suffer incoherent interactions with individual nuclei and may leave their bounded motion, i.e., they de-channel. The latter is the main limiting factor for applications of coherent interactions in crystal-assisted particle steering. We experimentally investigated the nature of de-channeling of 120 GeV/c e{sup -} and e{sup +} in a bent silicon crystal at H4-SPS external line at CERN. We found that while channeling efficiency differs significantly for e{sup -} (2 ± 2%) and e{sup +} (54 ± 2%), their nuclear de-channeling length is comparable, (0.6 ± 0.1) mm for e{sup -} and (0.7 ± 0.3) mm for e{sup +}. The experimental proof of the equality of the nuclear de-channeling length for positrons and electrons is interpreted in terms of similar dynamics undergone by the channeled particles in the field of nuclei irrespective of their charge. (orig.)

  13. Experimental investigation of virus and clay particles cotransport in partially saturated columns packed with glass beads.

    Science.gov (United States)

    Syngouna, Vasiliki I; Chrysikopoulos, Constantinos V

    2015-02-15

    Suspended clay particles in groundwater can play a significant role as carriers of viruses, because, depending on the physicochemical conditions, clay particles may facilitate or hinder the mobility of viruses. This experimental study examines the effects of clay colloids on the transport of viruses in variably saturated porous media. All cotransport experiments were conducted in both saturated and partially saturated columns packed with glass beads, using bacteriophages MS2 and ΦX174 as model viruses, and kaolinite (KGa-1b) and montmorillonite (STx-1b) as model clay colloids. The various experimental collision efficiencies were determined using the classical colloid filtration theory. The experimental data indicated that the mass recovery of viruses and clay colloids decreased as the water saturation decreased. Temporal moments of the various breakthrough concentrations collected, suggested that the presence of clays significantly influenced virus transport and irreversible deposition onto glass beads. The mass recovery of both viruses, based on total effluent virus concentrations, was shown to reduce in the presence of suspended clay particles. Furthermore, the transport of suspended virus and clay-virus particles was retarded, compared to the conservative tracer. Under unsaturated conditions both clay particles facilitated the transport of ΦX174, while hindered the transport of MS2. Moreover, the surface properties of viruses, clays and glass beads were employed for the construction of classical DLVO and capillary potential energy profiles, and the results suggested that capillary forces play a significant role on colloid retention. It was estimated that the capillary potential energy of MS2 is lower than that of ΦX174, and the capillary potential energy of KGa-1b is lower than that of STx-1b, assuming that the protrusion distance through the water film is the same for each pair of particles. Moreover, the capillary potential energy is several orders of

  14. Experimental and simulation studies on the behavior of signal harmonics in magnetic particle imaging.

    Science.gov (United States)

    Murase, Kenya; Konishi, Takashi; Takeuchi, Yuki; Takata, Hiroshige; Saito, Shigeyoshi

    2013-07-01

    Our purpose in this study was to investigate the behavior of signal harmonics in magnetic particle imaging (MPI) by experimental and simulation studies. In the experimental studies, we made an apparatus for MPI in which both a drive magnetic field (DMF) and a selection magnetic field (SMF) were generated with a Maxwell coil pair. The MPI signals from magnetic nanoparticles (MNPs) were detected with a solenoid coil. The odd- and even-numbered harmonics were calculated by Fourier transformation with or without background subtraction. The particle size of the MNPs was measured by transmission electron microscopy (TEM), dynamic light-scattering, and X-ray diffraction methods. In the simulation studies, the magnetization and particle size distribution of MNPs were assumed to obey the Langevin theory of paramagnetism and a log-normal distribution, respectively. The odd- and even-numbered harmonics were calculated by Fourier transformation under various conditions of DMF and SMF and for three different particle sizes. The behavior of the harmonics largely depended on the size of the MNPs. When we used the particle size obtained from the TEM image, the simulation results were most similar to the experimental results. The similarity between the experimental and simulation results for the even-numbered harmonics was better than that for the odd-numbered harmonics. This was considered to be due to the fact that the odd-numbered harmonics were more sensitive to background subtraction than were the even-numbered harmonics. This study will be useful for a better understanding, optimization, and development of MPI and for designing MNPs appropriate for MPI.

  15. Proceedings of the Workshop on Program Options in Intermediate-Energy Physics. Keynote address: New directions in elementary particle physics - pantip from very low to very high energies

    Energy Technology Data Exchange (ETDEWEB)

    Jacob, M.

    1980-05-01

    The recent development of cooling techniques offers the possibility to obtain intense sources of antiprotons, stacking them as they are produced at a multi-GeV accelerator. The wide array of applications presently considered, ranging from reactions at extremely low energy in the case of p anti p atoms to reactions at hundreds of GeV in the case of head-on collisions between protons and antiprotons accelerated at the same time in a super synchrotron, is reviewed. Special emphasis is put on the present CERN program, which will reach the data-taking stage in 1981. The study of p anti p interactions is meant as an illustration of how new possibilities open new directions in elementary particle physics, whether reaching energies hitherto much beyond accelerator possibilities or developing new lower-energy beams improved tremendously over those presently available. 14 figures, 1 table.

  16. Brain Gym To Increase Academic Performance Of Children Aged 10-12 Years Old ( Experimental Study in Tembalang Elementary School and Pedalangan Elementary School Semarang)

    Science.gov (United States)

    Marpaung, M. G.; Sareharto, T. P.; Purwanti, A.; Hermawati, D.

    2017-02-01

    Academic performance becomes an important determinant of individual quality. it is determined by the function of affective, cognitive, psychomotor, and intelligence. Brain gym can improve learning processes and integrate all areas that related to the learning process. To prove the effect of brain gym towards academic performance of children aged 10-12 years. This study was a quasy experiment study with one group pre and post test design. Samples (n=18 male=7 and female=11) were taken from five and six grader and conducted in Tembalang and Pedalangan Elementary School, Semarang. Pretest were administered, followed by brain gym, and post test administered in the end of study. The measurement of Intelligence Quotient pre and post test using Culture Fair Intelligence Test Scale 2. Among the 18 subjects (male=7 and female=11) the average of academic performance and IQ score after brain gym showed improvement. The Improvement of IQ score with Culture Fair Test Scale 2 was analyzed by Dependent T test showed significant results (p=0,000). The improvement of Bahasa score was analyzed by Wilcoxon test showed significant results (p=0,001), an unsignificant result were shown in Mathematics p=0,079 and natural sciences p=0,306. Brain gym can increase academic performance of children aged 10-12 years old.

  17. Gas−Solid Turbulent Flow in a Circulating Fluidized Bed Riser: Experimental and Numerical Study of Monodisperse Particle Systems

    NARCIS (Netherlands)

    He, Y.; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    Hydrodynamics of gas-particle two-phase turbulent flow in a circulating fluidized bed riser is studied experimentally by particle image velocimetry (PIV) and numerically with the use of a 3D discrete hard sphere particle model (DPM). The influence of the superficial gas velocity and the solids flux

  18. Experimental determination of LR-115 detector efficiency for exposure to alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Marocco, D.D.; Bochicchio, F.F. E-mail: bochicchio@iss.infn.it

    2001-06-01

    The alpha particle detection efficiency of LR-115 detectors has been measured against alpha particle energy E and incidence angle {theta} (with respect to the normal to the detector surface), using an experimental apparatus with an {sup 241}Am alpha source and air in a pressure-controlled chamber as the degrading medium, and a spark-counter for counting tracks. About 200 LR-115 detectors were exposed to alpha particles with E from 0.5 to 4.5 MeV (0.5 MeV step) and with {theta} from 0 deg. to 60 deg. (10 deg. step). Estimates of the critical angle {theta}{sub c} (the incidence angle above which no tracks were detected) as a function of E, and of E{sub min} and E{sub max} (energies, respectively, below which and above which no tracks were detected) against {theta} were obtained and compared with the results obtained by other authors.

  19. Is gravity less fundamental than elementary particles theory? Critical remarks on holography and E-infinity theory

    Energy Technology Data Exchange (ETDEWEB)

    El Naschie, Mohamed Saladin [Department of Physics, University of Alexandria (Egypt); Department of Astrophysics, Cairo University (Egypt); Department of Physics, Mansura University (Egypt)

    2006-08-15

    This work is concerned with showing, using various arguments, the possibility of giving an interpretation of the fundamental interactions conveying a mental picture in which gravity and general relativity would appear to be less fundamental than high energy particle physics.

  20. Experimental particle formation rates spanning tropospheric sulfuric acid and ammonia abundances, ion production rates, and temperatures

    CERN Document Server

    Kürten, Andreas; Almeida, Joao; Kupiainen-Määttä, Oona; Dunne, Eimear M.; Duplissy, Jonathan; Williamson, Christina; Barmet, Peter; Breitenlechner, Martin; Dommen, Josef; Donahue, Neil M.; Flagan, Richard C.; Franchin, Alessandro; Gordon, Hamish; Hakala, Jani; Hansel, Armin; Heinritzi, Martin; Ickes, Luisa; Jokinen, Tuija; Kangasluoma, Juha; Kim, Jaeseok; Kirkby, Jasper; Kupc, Agnieszka; Lehtipalo, Katrianne; Leiminger, Markus; Makhmutov, Vladimir; Onnela, Antti; Ortega, Ismael K.; Petäjä, Tuukka; Praplan, Arnaud P.; Riccobono, Francesco; Rissanen, Matti P.; Rondo, Linda; Schnitzhofer, Ralf; Schobesberger, Siegfried; Smith, James N.; Steiner, Gerhard; Stozhkov, Yuri; Tomé, António; Tröstl, Jasmin; Tsagkogeorgas, Georgios; Wagner, Paul E.; Wimmer, Daniela; Ye, Penglin; Baltensperger, Urs; Carslaw, Ken; Kulmala, Markku; Curtius, Joachim

    2016-01-01

    Binary nucleation of sulfuric acid and water as well as ternary nucleation involving ammonia arethought to be the dominant processes responsible for new particle formation (NPF) in the cold temperaturesof the middle and upper troposphere. Ions are also thought to be important for particle nucleation inthese regions. However, global models presently lack experimentally measured NPF rates under controlledlaboratory conditions and so at present must rely on theoretical or empirical parameterizations. Here withdata obtained in the European Organization for Nuclear Research CLOUD (Cosmics Leaving OUtdoor Droplets)chamber, we present the first experimental survey of NPF rates spanning free tropospheric conditions. Theconditions during nucleation cover a temperature range from 208 to 298 K, sulfuric acid concentrationsbet ween 5 × 105and 1 × 109cm3, and ammonia mixing ratios from zero added ammonia, i.e., nominally purebinary, to a maximum of ~1400 parts per trillion by volume (pptv). We performed nucleation s...

  1. An experimental technique for the direct measurement of N2O5 reactivity on ambient particles

    Directory of Open Access Journals (Sweden)

    T. H. Bertram

    2009-06-01

    Full Text Available An experimental approach for the direct measurement of trace gas reactivity on ambient aerosol particles has been developed. The method utilizes a newly designed entrained aerosol flow reactor coupled to a custom-built chemical ionization mass spectrometer. The experimental method is described via application to the measurement of the N2O5 reaction probability, γ (N2O5. Laboratory investigations on well characterized aerosol particles show that measurements of γ (N2O5 observed with this technique are in agreement with previous observations, using conventional flow tube methods, to within ±20% at atmospherically relevant particle surface area concentrations (0–1000 μm2 cm−3. Uncertainty in the measured γ (N2O5 is discussed in the context of fluctuations in potential ambient biases (e.g., temperature, relative humidity and trace gas loadings. Under ambient operating conditions we estimate a single-point uncertainty in γ (N2O5 that ranges between ± (1.3×10-2 + 0.2×γ (N2O5, and ± (1.3×10-3 + 0.2×γ (N2O5 for particle surface area concentrations of 100 to 1000 μm2 cm−3, respectively. Examples from both laboratory investigations and field observations are included alongside discussion of future applications for the reactivity measurement and optimal deployment locations and conditions.

  2. Experimental and statistical investigation of thermally induced failure in reactor fuel particles

    Energy Technology Data Exchange (ETDEWEB)

    Lunsford, J.L.; Imprescia, R.J.; Bowman, A.L.; Radosevich, C.E.

    1980-10-01

    An incomplete experimental study into the failure statistics of fuel particle for the high-temperature gas-cooled reactor (HTGR) is described. Fuel particles failure was induced by thermal ramping from room temperature to temperatures in the vicinity of 2273/sup 0/K to 2773/sup 0/K in 2 to 30 h and detected by the appearance of /sup 85/Kr in the helium carrier gas used to sweep the furnace. The concentration of krypton, a beta emitter, was detected by measuring the current that resulted when the helium sweep gas was passed through an ionization chamber. TRISO fuel particles gave a krypton concentration profile as a function of time that built up in several minutes and decayed in a fraction of an hour. This profile, which was temperature independent, was similar to the impulse response of the ionization chamber, suggesting that the TRISO particles failed instantaneously and completely. BISO fuel particles gave a krypton concentration profile as a function of time that built up in a fraction of an hour and decayed in a fraction of a day. This profile was strongly temperature dependent, suggesting that krypton release was diffusion controlled, i.e., that the krypton was diffusing through a sound coat, or that the BISO coating failed but that the krypton was unable to escape the kernel without diffusion, or that a combination of pre- and postfailure diffusion accompanied partial or complete failure.

  3. Violation of Particle Anti-particle Symmetry

    CERN Multimedia

    CERN. Geneva

    2001-01-01

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

  4. Experimental and theoretical study of particle transport in the TCV Tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Fable, E.

    2009-06-15

    The main scope of this thesis work is to compare theoretical models with experimental observations on particle transport in particular regimes of plasma operation from the Tokamak à Configuration Variable (TCV) located at CRPP–EPFL in Lausanne. We introduce the main topics in Tokamak fusion research and the challenging problems in the first Chapter. A particular attention is devoted to the modelling of heat and particle transport. In the second Chapter the experimental part is presented, including an overview of TCV capabilities, a brief review of the relevant diagnostic systems, and a discussion of the numerical tools used to analyze the experimental data. In addition, the numerical codes that are used to interpret the experimental data and to compare them with theoretical predictions are introduced. The third Chapter deals with the problem of understanding the mechanisms that regulate the transport of energy in TCV plasmas, in particular in the electron Internal Transport Barrier (eITB) scenario. A radial transport code, integrated with an external module for the calculation of the turbulence-induced transport coefficients, is employed to reproduce the experimental scenario and to understand the physics at play. It is shown how the sustainment of an improved confinement regime is linked to the presence of a reversed safety factor profile. The improvement of confinement in the eITB regime is visible in the energy channel and in the particle channel as well. The density profile shows strong correlation with the temperature profile and has a large local logarithmic gradient. This is an important result obtained from the TCV eITB scenario analysis and is presented in the fourth Chapter. In the same chapter we present the estimate of the particle diffusion and convection coefficients obtained from density transient experiments performed in the eITB scenario. The theoretical understanding of the strong correlation between density and temperature observed in the e

  5. Progress report on research program in elementary particle theory, 1979-1980. [Univ. of Texas at Austin

    Energy Technology Data Exchange (ETDEWEB)

    Sudarshan, E.C.G.; Ne' eman, Y.

    1980-01-01

    A qualitative description is given of research in the following areas: particle physics in relativistic astrophysics and cosmology; phenomenology of weak and electromagnetic interactions; strong interaction physics and quark-parton physics; quantum mechanics, quantum field theory, and fundamental problems; and groups, gauges, and grand unified theories. Reports on this work have already been published, or will be, when it is completed. (RWR)

  6. SIZE ANALYSIS OF SOLID PARTICLES AT THE EXPERIMENTAL DEVICE FOR MULTI-STAGE BIOMASS COMBUSTION

    Directory of Open Access Journals (Sweden)

    Michaela Hrnčířová

    2014-02-01

    Full Text Available This paper presents the results of an analysis of ash content particles produced in biomass combustion at an experimental device. The main parts of the device are: the water heater, the gasifying chamber, the air preheater, and the fuel feeder. This device can be modified for combustion in an oxygen-enriched atmosphere. Sawdust and wood chips were used as fuel, and were laid loosely into the device. Ash specimens were extracted from various parts of the device. For the measurements themselves, we used the Analysette 22 MicroTec Plus universal laser diffraction device manufactured by the Fritch Company, in the size range from 0.08 μm to 2000 μm. The device utilizes laser diffraction for particle size analysis.

  7. First results from solid state neutral particle analyzer on experimental advanced superconducting tokamak

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, J. Z.; Zhao, J. L.; Wan, B. N.; Li, J. G. [Institute of Plasma Physics, Chinese Academy of Sciences, Hefei 230031 (China); Zhu, Y. B., E-mail: y.zhu@uci.edu; Heidbrink, W. W. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States)

    2016-11-15

    Full function integrated, compact solid state neutral particle analyzers (ssNPA) based on absolute extreme ultraviolet silicon photodiode have been successfully implemented on the experimental advanced superconducting tokamak to measure energetic particle. The ssNPA system has been operated in advanced current mode with fast temporal and spatial resolution capabilities, with both active and passive charge exchange measurements. It is found that the ssNPA flux signals are increased substantially with neutral beam injection (NBI). The horizontal active array responds to modulated NBI beam promptly, while weaker change is presented on passive array. Compared to near-perpendicular beam, near-tangential beam brings more passive ssNPA flux and a broader profile, while no clear difference is observed on active ssNPA flux and its profile. Significantly enhanced intensities on some ssNPA channels have been observed during ion cyclotron resonant heating.

  8. Experimental evidence for the role of ions in particle nucleation under atmospheric conditions

    DEFF Research Database (Denmark)

    Svensmark, Henrik; Pedersen, Jens Olaf Pepke; Marsh, N.D.

    2007-01-01

    Experimental studies of aerosol nucleation in air, containing trace amounts of ozone, sulphur dioxide and water vapour at concentrations relevant for the Earth's atmosphere, are reported. The production of new aerosol particles is found to be proportional to the negative ion density and yields...... nucleation rates of the order of 0.1 1 cm(-3) s(-1). This suggests that the ions are active in generating an atmospheric reservoir of small thermodynamically stable clusters, which are important for nucleation processes in the atmosphere and ultimately for cloud formation....

  9. Experimental and theoretical analysis of particle entrainment in dry, uniform-unsteady granular flows

    Science.gov (United States)

    Larcher, Michele; Fraccarollo, Luigi; Prati, Anna

    2017-04-01

    Experiments performed in steady-uniform flow conditions are often considered as a reference for investigating flow rheology and developing theoretical models of grain interaction for a wide range of geophysical flows, including sediment transport, debris flow, mudflow and snow avalanches. However in order to understand how this kind of flows evolve in time and space during their growing and deposition phase, alternative experimental conditions should be investigated, permitting to focus on the grain-scale mechanics of particle entrainment and disentrainment. This is a crucial aspect especially for the description of geophysical flows characterized by a very rapid evolution phase. As an example, snow avalanches, after being triggered, can increase their volume by orders of magnitude within a few seconds. The interpretation of experiments in unsteady and non-uniform condition can be complicated, especially as far as the understanding of the functional relationship between the several involved variables. Therefore, we decided to design an experiment in which the particle entrainment could be measured in a flow evolving just in time, what we call here the uniform-unsteady condition. We used a 164 cm long and 5 cm wide flume, uniformly filled with a layer of particles arranged in order to obtain a homogeneous depth. Two different types of grains were used: plastic spheres with a diameter of 0.45 mm, a density of 0.98 kg/m3 and a friction angle of 21° and PVC cylinders with an equivalent diameter (sphere having the same volume) of 3.50 mm, a density of 1.51 kg/m3 and a friction angle of 31°. After carefully arranging the layer of particles in order to obtain a uniform depth (between 3 and 5 cm), the particles were pressed from above by a rigid plate in order to keep them at rest. The flume was then tilted to a slope larger than the friction angle and the plate was suddenly released, causing the particles to move. This particular experimental configuration induced a

  10. Experimental and theoretical study of dielectrophoretic particle trapping in arrays of insulating structures: Effect of particle size and shape.

    Science.gov (United States)

    Saucedo-Espinosa, Mario A; Lapizco-Encinas, Blanca H

    2015-05-01

    Insulator-based dielectrophoresis (iDEP) employs insulating structures embedded in a microchannel to produce electric field gradients. This contribution presents a detailed analysis of the regions within an iDEP system where particles are likely to be retained due to dielectrophoretic trapping in a microchannel with an array of cylindrical insulating structures. The effects of particle size and shape on dielectrophoretic trapping were analyzed by employing 1 and 2 μm polystyrene particles and Escherichia coli cells. This research aims to study the mechanism behind dielectrophoretic trapping and develop a deeper understanding of iDEP systems. Mathematical modeling with COMSOL Multiphysics was employed to assess electrokinetic and dielectrophoretic particle velocities. Experiments were carried out to determine the location of dielectrophoretic barriers that block particle motion within an iDEP microchannel; this supported the estimation of a correction factor to match experiments and simulations. Particle velocities were predicted with the model, demonstrating how the different forces acting on the particles are in equilibrium when particle trapping occurs. The results showed that particle size and shape have a significant effect on the magnitude, location, and shape of the regions of dielectrophoretic trapping of particles, which are defined by DEP isovelocity lines and EK isovelocity lines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Tuning PID attitude stabilization of a quadrotor using particle swarm optimization (experimental

    Directory of Open Access Journals (Sweden)

    Khodja Mohammed Abdallah

    2017-01-01

    Full Text Available Proportional, Integral and Derivative (PID controllers are the most popular type of controller used in industrial applications because of their notable simplicity and effective implementation. However, manual tuning of these controllers is tedious and often leads to poor performance. The conventional Ziegler-Nichols (Z-N method of PID tuning was done experimentally enables easy identification stable PID parameters in a short time, but is accompanied by overshoot, high steady-state error, and large rise time. Therefore, in this study, the modern heuristics approach of Particle Swarm Optimization (PSO was employed to enhance the capabilities of the conventional Z-N technique. PSO with the constriction coefficient method experimentally demonstrated the ability to efficiently and effectively identify optimal PID controller parameters for attitude stabilization of a quadrotor.

  12. Impacts of radiation exposure on the experimental microbial ecosystem: a particle-based model simulation approach

    Energy Technology Data Exchange (ETDEWEB)

    Doi, M.; Tanaka, N.; Fuma, S.; Kawabata, Z.

    2004-07-01

    Well-designed experimental model ecosystem could be a simple reference of the actual environment and complex ecological systems. For ecological toxicity test of radiation and other environmental toxicants, we investigated and aquatic microbial ecosystem (closed microcosm) in the test tube with initial substrates,autotroph flagellate algae (Euglena, G.), heterotroph ciliate protozoa (Tetrahymena T.) and saprotroph bacteria (E, coli). These species organizes by itself to construct the ecological system, that keeps the sustainable population dynamics for more than 2 years after inoculation only by adding light diurnally and controlling temperature at 25 degree Celsius. Objective of the study is to develop the particle-based computer simulation by reviewing interactions among microbes and environment, and analyze the ecological toxicities of radiation on the microcosm by replicating experimental results in the computer simulation. (Author) 14 refs.

  13. Experimental Observation of Direct Particle Acceleration by Stimulated Emission of Radiation

    Science.gov (United States)

    Banna, Samer; Berezovsky, Valery; Schächter, Levi

    2006-09-01

    We report the first experimental evidence for direct particle acceleration by stimulated emission of radiation. In the framework of this proof-of-principle experiment, a 45 MeV electron macrobunch was modulated by a high-power CO2 laser and then injected into an excited CO2 gas mixture. The emerging microbunches experienced a 0.15% relative change in the kinetic energy, in a less than 40 cm long interaction region. According to our experimental results, a fraction of these electrons have gained more than 200 keV each, implying that such an electron has undergone an order of magnitude of 2×106 collisions of the second kind.

  14. Particle Shape Effect on Macroscopic Behaviour of Underground Structures: Numerical and Experimental Study

    Directory of Open Access Journals (Sweden)

    Szarf Krzysztof

    2015-02-01

    Full Text Available The mechanical performance of underground flexible structures such as buried pipes or culverts made of plastics depend not only on the properties of the structure, but also on the material surrounding it. Flexible drains can deflect by 30% with the joints staying tight, or even invert. Large deformations of the structure are difficult to model in the framework of Finite Element Method, but straightforward in Discrete Element Methods. Moreover, Discrete Element approach is able to provide information about the grain-grain and grain-structure interactions at the microscale. This paper presents numerical and experimental investigations of flexible buried pipe behaviour with focus placed on load transfer above the buried structure. Numerical modeling was able to reproduce the experimental results. Load repartition was observed, being affected by a number of factors such as particle shape, pipe friction and pipe stiffness.

  15. Summer Workshop on Particle Physics

    CERN Document Server

    Chamseddine, A H; Nath, Pran

    1984-01-01

    These lectures give an elementary introduction to the important recent developments of the applications of N=1 supergravity to the construction of unified models of elementary particle interactions. Topics covered include couplings of supergravity with matter, spontaneous symmetry breaking and the super-higgs effect, construction of supergravity unified models, and the phenomenon of SU(2) x U(1) electroweak-symmetry breaking by supergravity. Experimental consequences of N-1 supergravity unified theory, in particular, the possible supersymmetric decays of the W ± and Z 0 bosons, are also discus

  16. Final Report for 3-year grant no. DE-FG05-85ER40226. Investigations in Elementary Particle Theory.

    Energy Technology Data Exchange (ETDEWEB)

    Kephart, Thomas W. [Vanderbilt Univ., Nashville, TN (United States); Scherrer, Robert J. [Vanderbilt Univ., Nashville, TN (United States); Weiler, Thomas J. [Vanderbilt Univ., Nashville, TN (United States)

    2014-11-23

    The research interests of our three Co-PI’s complement each other very well. Kephart works mainly on models of particle unification in four or higher dimensions, on aspects of gravity such as inflation, black-holes, and the very early Universe, and on applications of knot theory and topology to various physical systems (including gluon dynamics). Scherrer works mainly on aspects of the intermediate-aged Universe, including dark matter and dark energy, and particle physics in the early Universe. Weiler works mainly on neutrino physics, dark matter signatures, and extreme particle-astrophysics in the late Universe, including origins of the highest-energy cosmic-rays and gamma-rays, and the future potential of neutrino astrophysics. Kephart and Weiler have lately devoted some research attention to the LHC and its reach for probing physics beyond the Standard Model. During the 3-year funding period, our grant supported one postdoc (Chiu Man Ho) and partially supported two students, Peter Denton and Lingjun Fu. Chiu Man collaborated with all three of the Co-PI’s during the 3-year funding period and published 16 refereed papers. Chiu Man has gone on to a postdoc with Steve Hsu at Michigan State University. Denton and Fu will both receive their PhDs during the 2014-15 academic year. The total number of our papers published in refereed journals by the three co-PIs during the period of this grant (2011-present) is 54. The total number of talks given by the group members during this time period, including seminars, colloquia, and conference presentations, is 47. Some details of the accomplishments of our DOE funded researchers during the grant period include Weiler being named a Simons Fellow in 2013. He presented an invited TEDx talk in 2012. His paper on closed timelike curves (2013) garnered a great deal of national publicity. Scherrer’s paper on the “little rip” (2011) fostered a new area of cosmological research, and the name “little rip” has now entered

  17. The Particle Physics Playground website: tutorials and activities using real experimental data

    Science.gov (United States)

    Bellis, Matthew; CMS Collaboration

    2016-03-01

    The CERN Open Data Portal provides access to data from the LHC experiments to anyone with the time and inclination to learn the analysis procedures. The CMS experiment has made a significant amount of data availible in basically the same format the collaboration itself uses, along with software tools and a virtual enviroment in which to run those tools. These same data have also been mined for educational exercises that range from very simple .csv files that can be analyzed in a spreadsheet to more sophisticated formats that use ROOT, a dominant software package in experimental particle physics but not used as much in the general computing community. This talk will present the Particle Physics Playground website (http://particle-physics-playground.github.io/), a project that uses data from the CMS experiment, as well as the older CLEO experiment, in tutorials and exercises aimed at high school and undergraduate students and other science enthusiasts. The data are stored as text files and the users are provided with starter Python/Jupyter notebook programs and accessor functions which can be modified to perform fairly high-level analyses. The status of the project, success stories, and future plans for the website will be presented. This work was supported in part by NSF Grant PHY-1307562.

  18. Diagnostics of Particles emitted from a Laser generated Plasma: Experimental Data and Simulations

    Directory of Open Access Journals (Sweden)

    Costa Giuseppe

    2018-01-01

    Full Text Available The charge particle emission form laser-generated plasma was studied experimentally and theoretically using the COMSOL simulation code. The particle acceleration was investigated using two lasers at two different regimes. A Nd:YAG laser, with 3 ns pulse duration and 1010 W/cm2 intensity, when focused on solid target produces a non-equilibrium plasma with average temperature of about 30-50 eV. An Iodine laser with 300 ps pulse duration and 1016 W/cm2 intensity produces plasmas with average temperatures of the order of tens keV. In both cases charge separation occurs and ions and electrons are accelerated at energies of the order of 200 eV and 1 MeV per charge state in the two cases, respectively. The simulation program permits to plot the charge particle trajectories from plasma source in vacuum indicating how they can be deflected by magnetic and electrical fields. The simulation code can be employed to realize suitable permanent magnets and solenoids to deflect ions toward a secondary target or detectors, to focalize ions and electrons, to realize electron traps able to provide significant ion acceleration and to realize efficient spectrometers. In particular it was applied to the study two Thomson parabola spectrometers able to detect ions at low and at high laser intensities. The comparisons between measurements and simulation is presented and discussed.

  19. Simulation and experimental studies on electron cloud effects in particle accelerators

    CERN Document Server

    Romano, Annalisa; Cimino, Roberto; Iadarola, Giovanni; Rumolo, Giovanni

    Electron Cloud (EC) effects represent a serious limitation for particle accelerators operating with intense beams of positively charged particles. This Master thesis work presents simulation and experimental studies on EC effects carried out in collaboration with the European Organization for Nuclear Research (CERN) in Geneva and with the INFN-LNF laboratories in Frascati. During the Long Shut- down 1 (LS1, 2013-2014), a new detector for EC measurements has been installed in one of the main magnets of the CERN Proton Synchrotron (PS) to study the EC formation in presence of a strong magnetic field. The aim is to develop a reli- able EC model of the PS vacuum chamber in order to identify possible limitation for the future high intensity and high brightness beams foreseen by Large Hadron Collider (LHC) Injectors Upgrade (LIU) project. Numerical simulations with the new PyECLOUD code were performed in order to quantify the expected signal at the detector under different beam conditions. The experimental activity...

  20. Experimental and simulated scattering matrices of small calcite particles at 647nm

    Science.gov (United States)

    Dabrowska, D. D.; Muñoz, O.; Moreno, F.; Nousiainen, T.; Zubko, E.; Marra, A. C.

    2013-07-01

    We present measurements of the complete scattering matrix as a function of the scattering angle of a sample of calcite particles. The measurements are performed at 647nm in the scattering angle range from 3° to 177°. To facilitate the use of the experimental data we present a synthetic scattering matrix based on the measurements and defined in the full range from 0° to 180°. The scattering matrix of the calcite sample is modeled using the discrete-dipole approximation. Two sets of shapes, flake-like and rhomboid-like particles giving a total of 15 different targets are considered since both types of shapes have been found in our calcite sample. In our computations we use the measured size distribution of the calcite sample truncated at 1.2μm. We present a theoretical study of the impact of birefringence on the computed scattering matrix elements for both sets of shapes. Four different cases regarding the composition of the calcite particles are considered: two isotropic cases corresponding to the ordinary and extraordinary refractive index of calcite, respectively; one equivalent isotropic case analogous to internal mixing; and birefringence fully accounted for. Numerical simulations are compared with the experimental data. We find that birefringence has little impact on the calculated phase functions but it has a significant effect on the polarization-related elements of the scattering matrix. Moreover, we conclude that the shape of the targets (flakes or irregular rhomboids) has a much stronger effect on the computed scattering matrix elements than birefringence.

  1. Experimental Research of Influence of a Relative Particles Positioning in a Gas Stream on Characteristics of their Aerodynamic Traces

    Directory of Open Access Journals (Sweden)

    Volkov Roman S.

    2016-01-01

    Full Text Available The cycle of experimental studies on determination of length of aerodynamic traces of the particles which are flowed round by an air stream is executed. When carrying out researches, panoramic optical methods for diagnostics of multiphase flows of PIV and PTV were used. Velocities of an air flow were varied in the range of 1-3 m/s. The sizes of particles changed from 1mm to 5 mm. The defining influence of the sizes of particles and velocities of an air stream on length of aerodynamic traces is established. Influence of a relative positioning of particles on features of formation of an aerodynamic trace is shown.

  2. Nano-motion control of heavy quadrupoles for future particle colliders: An experimental validation

    CERN Document Server

    Collette, C; Artoos, K; Kuzmin, A; Fernandez Carmona, P; Guinchard, M; Leuxe, R; Hauviller, C

    2011-01-01

    This paper presents an experimental validation of a control strategy capable of boths tabilizing and positioning the heavy electromagnets of future particle colliders. The originality of the approach is to use the same active mounts to perform both tasks,with a nanometer precision.In aprevious paper,the concept has been studied numerically,and validated on a scaled single degree of freedom(d.o.f.) test bench.In this paper,it is extended to a two d.o.f. testbench,constituted of a heavy mass mounted on two active legs.Firstly,the model is described and the performances are discussed numerically. Secondly,experimental results are presented,and found to correlate well with the model,and comply with the requirements.Finally,the experimental results are combined with a simplified model of the beam-based feedback to evaluate the jitter of the beam.It is found that,at the scale of a single quadrupole,the mechanical stabilization of the quadrupoles reduces the vertical beam jitter by a factor 10.

  3. Experimental study of the cross-sections of alpha-particle induced reactions on $^{209}$Bi

    CERN Document Server

    Hermanne, A; Shubin, Yu N; Szucs, Z; Takács, S; Tarkanyi, F; 10.1016/j.apradiso.2005.01.015

    2005-01-01

    alpha -particle-induced nuclear reactions for generation of /sup 211 /At used in therapeutic nuclear medicine and possible contaminants were investigated with the stacked foil activation technique on natural bismuth targets up to E/sub alpha /=39 MeV. Excitation functions are reported for the reactions /sup 209/Bi( alpha ,2n)/sup 211/At, /sup 209/Bi( alpha ,3n)/sup 210/At and /sup 209/Bi( alpha , x)/sup 210/Po. Results obtained from direct alpha -emission measurements and gamma -spectra from decay products are compared and correspond well with earlier literature values. Thick target yields have been deduced from the experimental cross-sections and optimised production pathways for minimal contamination are presented. A comparison with the results of the theoretical model code ALICE-IPPE is discussed.

  4. Experimental proof of Faster-is-Slower in multi-particle systems flowing through bottlenecks

    CERN Document Server

    Pastor, José M; Gago, Paula A; Peralta, Juan P; Martín-Gómez, César; Ferrer, Luis M; Maza, Diego; Parisi, Daniel R; Pugnaloni, Luis A; Zuriguel, Iker

    2015-01-01

    The "faster-is-slower" (FIS) effect was first predicted by computer simulations of the egress of pedestrians through a narrow exit [Helbing D, Farkas I J, Vicsek T, Nature 407:487-490 (2000)]. FIS refers to the finding that, under certain conditions, an excess of the individuals' vigor in the attempt to exit causes a decrease in the flow rate. In general, this effect is identified by the appearance of a minimum when plotting the total evacuation time of a crowd as a function of the pedestrian desired velocity. Here, we experimentally show that the FIS effect indeed occurs in three different systems of discrete particles flowing through a constriction: (a) humans evacuating a room, (b) a herd of sheep entering a barn and (c) grains flowing out a 2D hopper over a vibrated incline. This finding suggests that FIS is a universal phenomenon for active matter passing through a narrowing.

  5. Experimental setup for the growth of solid crystals of inert gases for particle detection

    Science.gov (United States)

    Guarise, M.; Braggio, C.; Calabrese, R.; Carugno, G.; Dainelli, A.; Khanbekyan, A.; Luppi, E.; Mariotti, E.; Poggi, M.; Tomassetti, L.

    2017-11-01

    Low energy threshold detectors are necessary in many frontier fields of the experimental physics. In this work, we present a novel detection approach based on pure or doped matrices of inert gases solidified at cryogenic temperatures. The small energy release of the incident particle can be transferred directly (in pure crystals) or through a laser-driven ionization (in doped materials) to the electrons of the medium that are then converted into free electrons. The charge collection process of the electrons that consists in their drift within the crystal and their extraction through the solid-vacuum interface gives rise to an electric signal that we exploit for preliminary tests of charge collection and crystal quality. Such tests are carried out in different matrices of neon and methane using an UV-assisted apparatus for electron injection in crystals.

  6. Experimental study of acoustic agglomeration of coal-fired fly ash particles at low frequencies

    Energy Technology Data Exchange (ETDEWEB)

    Liu, J.Z.; Zhang, G.X.; Zhou, J.H.; Wang, J.; Zhao, W.D.; Cen, K.F. [Zhejiang University, Zhejiang (China)

    2009-07-15

    This paper presents an experimental study of acoustic agglomeration of coal-fired fly ash particles in travelling sound waves. The ranges of variation of the main physical parameters are as follows: acoustic frequency, f = 700-3000 Hz; sound pressure level (SPL), SPL = 130-147 dB; residence time, t = 3-7 s; aerosol number concentration, N{sub 0} = 1.0 x 10{sup 5}-3.7 x 10{sup 5}/cm{sup 3}. A 68.4% decrease in total number concentration is gained under an SPL of 147 dB and a frequency of 1400 Hz. Aggregates larger than 10 {mu}m are observed in scanning electron microscopy photographs. The results show that the effect of sound waves is very sensitive to the frequency change, which means that orthokinetic interaction governs the process. There exists an optimum frequency for a given particle size distribution, which decreases slightly as SPL increases. The influences of SPL, residence time and initial total number concentration are also studied.

  7. The coefficient of restitution of ice particles in glancing collisions: Experimental results for unfrosted surfaces

    Science.gov (United States)

    Supulver, Kimberley D.; Bridges, Frank G.; Lin, D. N. C.

    1995-01-01

    Both Saturn's rings and planetesimal disks are made up of particles in Keplerian orbits. Inelastic collisions between these particles regulate their dynamical evolution and possible aggregation. We present an experiment to simulate glancing collisions in Saturn's rings and in planetesimal disks and thus measure contributions to the energy loss for both normal and tangential velocity components. In this experiment, a spherical iceball mounted on a long-period, two dimensional pendulum is made to impact a flat ice surface in a low-temperature environment. This paper describes the experimental apparatus in detail and presents results for smooth unfrosted surfaces. The energy loss for tangential motion is suprisingly low, indicating that very little friction is present at low impact speeds for relatively smooth ice surfaces and temperatures near 100 K. We have also investigated room-temperature collisions of a rubber ball on a rough surface to understand the energy loss in situations where the tangential friction force is not small. In this analogous case, the energy loss is maximum for impact angles in the range 45 deg-60 deg.

  8. Experimental study of single-phase pressure drops in coarse particle beds

    Energy Technology Data Exchange (ETDEWEB)

    Clavier, R., E-mail: remi.clavier@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Chikhi, N., E-mail: nourdine.chikhi@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Fichot, F., E-mail: florian.fichot@irsn.fr [IRSN Cadarache, Saint Paul-lez-Durance (France); Quintard, M., E-mail: Michel.Quintard@imft.fr [Université de Toulouse, Allée Camille Soula, F-31400 Toulouse (France); INPT, UPS, Allée Camille Soula, F-31400 Toulouse (France); IMFT (Institut de Mécanique des Fluides de Toulouse), Allée Camille Soula, F-31400 Toulouse (France); CNRS, F-31400 Toulouse (France)

    2017-02-15

    Motivated by uncertainty reduction in nuclear debris beds coolability, experiments have been conducted on the CALIDE facility in order to investigate single-phase pressure losses in representative debris beds, i.e., high sphericity (>80%) particle beds with small size dispersion (from 1 mm to 10 mm), for which no validated model exists. In this paper, experimental results are presented and analyzed in order to identify a simple correlation for single-phase flow pressure losses generated in this kind of porous media in reflooding flowing conditions, which cover Darcy to weakly turbulent regimes. In the literature, it has been observed that their behavior can be accurately described by a Darcy–Forchheimer law, involving the sum of a linear term and a quadratic non-linear deviation, with respect to the filtration velocity. Expressions for the coefficients of the linear and quadratic terms are determined by assessing the possibility to evaluate equivalent diameters, i.e., characteristic lengths allowing correct predictions of the linear and quadratic terms by the Ergun equation. It has been observed that the Sauter diameter of particles allows a very precise prediction of the linear term, while the quadratic term can be predicted using the product of the Sauter diameter and a sphericity coefficient as an equivalent diameter.

  9. Particle Size Distrbution in an Experimental Hypervelocity Impact on Dry Sandstone.

    Science.gov (United States)

    Buhl, Elmar; Poelchau, Michael H.; Deutsch, Alex; Kenkmann, Thomas; Dresen, Georg

    2013-04-01

    The particle size distribution (PSD) is a frequently used parameter to describe the deformation-induced fragmentation of fault rocks. It has been shown that resulting particle sizes may be described by a power law (fractal) size distribution: N(d) ~ dD where N(d) is the number of particles larger than diameter d, and D is the D-value. PSDs reported for impact deformation are still very few. D-values for natural and experimental impacts have been reported to range between 1.2-1.8 and 1.4-1.7, respectively. Here we show the systematic distribution of the PSD in the subsurface of an experimental impact crater. The investigated experiment was performed in the framework of the MEMIN project [1]. A 20 cm cube of quartz-rich sandstone (Seeberger Sandstein) was impacted by a 2.5 mm steel sphere at 4.8 km/s, producing a crater of 5.76 cm diameter and 11.0 mm depth [2]. For sample preparation the crater was impregnated with epoxy and the block was bisected. Thin sections were prepared from the crater sub-surface. Backscattered electron (BSE) micro-analysis was conducted by means of a Zeiss Leo 1525 Scanning Electron Microscope. A succession of 20 images (400x magnification) with increasing distance from the crater floor was analyzed. The image analysis software JMicrovision was used for automated object extraction. Area and perimeter of all detected particles were exported and used for PSD analysis. The obtained PSD were fit with a linear function in a log-log plot over at least one order of magnitude in diameter indicating that the PSD follows a power law relationship N(d) ~ dD. The distinct modes of deformation in the crater sub-surface [3] are closely linked to the fracture pattern and thus with the D-value. As expected, comminution was most effective closest to the crater floor. The highest D-value of 1.74 was found at a depth of 0.26-1.07 mm beneath the crater floor. Thus the largest fraction of fine material is situated in there. With growing distance the D-values drop

  10. Experimental verification of theoretical equations for acoustic radiation force on compressible spherical particles in traveling waves

    Science.gov (United States)

    Johnson, Kennita A.; Vormohr, Hannah R.; Doinikov, Alexander A.; Bouakaz, Ayache; Shields, C. Wyatt; López, Gabriel P.; Dayton, Paul A.

    2016-05-01

    Acoustophoresis uses acoustic radiation force to remotely manipulate particles suspended in a host fluid for many scientific, technological, and medical applications, such as acoustic levitation, acoustic coagulation, contrast ultrasound imaging, ultrasound-assisted drug delivery, etc. To estimate the magnitude of acoustic radiation forces, equations derived for an inviscid host fluid are commonly used. However, there are theoretical predictions that, in the case of a traveling wave, viscous effects can dramatically change the magnitude of acoustic radiation forces, which make the equations obtained for an inviscid host fluid invalid for proper estimation of acoustic radiation forces. To date, experimental verification of these predictions has not been published. Experimental measurements of viscous effects on acoustic radiation forces in a traveling wave were conducted using a confocal optical and acoustic system and values were compared with available theories. Our results show that, even in a low-viscosity fluid such as water, the magnitude of acoustic radiation forces is increased manyfold by viscous effects in comparison with what follows from the equations derived for an inviscid fluid.

  11. An experimental design for the investigation of water repellent property of candle soot particles

    Energy Technology Data Exchange (ETDEWEB)

    Sahoo, Bichitra Nanda; Kandasubramanian, Balasubramanian, E-mail: meetkbs@gmail.com

    2014-11-14

    The mechanistic aspect of candle soot particles under controlled atmosphere has been reported. The soot particles were characterized using Fourier transformation Infrared Spectroscopy, Raman spectroscopy, Transmission electron microscopy and X-ray diffraction. Hydrophobicity of the candle soot particles was confirmed from the presence of C–H group which enhances water repellency and can be used as filler material for fabrication of superhydrophobic coatings. The layered soot particle on the glass slide exhibits maximum water contact angle of 168°. Roughness of soot particle and various hydrophobic groups involved for obtaining superhydrophobicity were exposed. The Raman spectrum of soot particles revealed the presence of disorder graphene which was confirmed from appearance of D1 band. The agglomeration of candle soot particles has been discussed by measuring fractal dimension (D{sub f}) of the particles. The in-depth investigation for bringing the mechanism of formation of soot particle inside the flame reveals the inception of the first particles, growth of soot particles, particle coalescence, agglomeration and oxidation. Here, we have found that the mechanism of particle formation in candle flame involves various steps, in which the sintering as well as coalescence/collision process plays a major role. - Highlights: • Mechanistic aspect for hydrophobicity of candle soot is demonstrated. • Hydrophobicity of soot particles at different exposure time is described. • Agglomeration of soot particles related to fractal dimension is reported. • Mechanism of formation of soot particles in the candle flame is also described.

  12. Elementary, Dear Albert

    CERN Multimedia

    2017-01-01

    Elementary, Dear Albert! fiction based upon every physicist's dream: have a chat with Albert Einstein. Starring theoretical physicist Alvaro de Rujula in the role of Dr. Nuts and experimental physicist Federico Antinori in the role of Albert Einstein. Directed by Silvano de Gennaro

  13. Mesostructural investigation of micron-sized glass particles during shear deformation – An experimental approach vs. DEM simulation

    Directory of Open Access Journals (Sweden)

    Torbahn Lutz

    2017-01-01

    Full Text Available The interdependency of structure and mechanical features of a cohesive powder packing is on current scientific focus and far from being well understood. Although the Discrete Element Method provides a well applicable and widely used tool to model powder behavior, non-trivial contact mechanics of micron-sized particles demand a sophisticated contact model. Here, a direct comparison between experiment and simulation on a particle level offers a proper approach for model validation. However, the simulation of a full scale shear-tester experiment with micron-sized particles, and hence, validating this simulation remains a challenge. We address this task by down scaling the experimental setup: A fully functional micro shear-tester was developed and implemented into an X-ray tomography device in order to visualize the sample on a bulk and particle level within small bulk volumes of the order of a few micro liter under well-defined consolidation. Using spherical micron-sized particles (30 μm, shear tests with a particle number accessible for simulations can be performed. Moreover, particle level analysis allows for a direct comparison of experimental and numerical results, e.g., regarding structural evolution. In this talk, we focus on density inhomogeneity and shear induced heterogeneity during compaction and shear deformation.

  14. Structural effects on the oxidation of soot particles by O2: Experimental and theoretical study

    KAUST Repository

    Raj, Abhijeet

    2013-09-01

    Soot particles are composed of polycyclic aromatic hydrocarbons (PAHs), which have either planar or curved structures. The oxidation behaviors of soot particles differ depending on their structures, arrangement of PAHs, and the type of surface functional groups. The oxidation rate of curved PAHs in soot is thought to be higher than that of planar ones. To understand the role that PAH structure plays in soot reactivity towards O2, experimental studies are conducted on two types of commercially produced soot, Printex-U and Fullerene soot, using high resolution transmission electron microscopy, electron energy loss spectroscopy, thermo-gravimetric analysis and elemental analysis. The relative concentrations of active sites, oxygenated functional groups, aliphatics and aromatics present in soots are evaluated. The activation energies for soot oxidation at different conversion levels are determined. The average activation energies of the two soots are found to differ by 26kJ/mol. To understand the reason for this difference, quantum calculations using density functional (B3LYP) and Hartree-Fock theories are conducted to study the reaction pathways of the oxidation by O2 of planar and curved PAHs using 4-pyrenyl and 1-corannulenyl as their model molecules, respectively. The energetically preferred channels for curved PAH oxidation differ from the planar one. The addition of O2 on a radical site of a six-membered ring to form a peroxyl radical is found to be barrierless for both the model PAHs. For peroxyl decomposition, three pathways are suggested, each of which involve the activation energies of 108, 170 and 121kJ/mol to form stable molecules in the case of planar PAH, and 94, 155 and 125kJ/mol in the case of curved PAH. During the oxidation of a five-membered ring, to form stable molecules, the activation energies of 90kJ/mol for the curved PAH and 169kJ/mol for the planar PAH relative to the energy of the peroxyl radical are required. The low activation barriers of

  15. Experimental Investigation of the Effect of Spherical Particle Size Distribution on Frictional Pressure drop in Particulate Debris Bed

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jin Ho; Kim, Eunho; Park, Hyun Sun [POSTECH, Daejeon (Korea, Republic of)

    2015-10-15

    It is important to ensure the coolant ingression into the internally heat generated debris bed which is governed by pressure drop in debris bed to assure the long-term cooling of debris bed on the cavity floor. For this reason, it is necessary to understand the pressure drop mechanism in porous bed that can be characterized by physical parameters that include porosity, particle morphology, particle size distribution etc. According to previous investigations on molten fuel coolant interaction (FCI) experiment, the settled particulate debris bed after fuel-coolant interaction were stratified and it was composed of multi-sized particles with irregular shape. (Karbojian et al., 2009; Magallon, 2006). Among these characteristics of debris bed, this study focused on the effect of particle size distribution on frictional pressure drop in bed. The experiment using single-phase water was conducted to investigate the effect of spherical particle size distribution on frictional pressure drop in mixed bed. This study reports the experimental data for measured frictional pressure drops in bed according to the particle Reynolds number. It is composed of multi-sized spherical particles whose sizes are varied from 1 mm to 10 mm. Besides, the experimental data is compared to the Ergun equation with the mean particle diameters (mass, area, length, and number mean diameters). The results of this study are also compared to those of KTH published in 2011. The conclusions are summarized as follows. The calculated mean particle diameters can be changed according to chosen particle sizes and those mass fractions even though the cumulative mass fractions are almost similar trend. As results of obtaining the effective diameter in mixed using measured frictional pressure drops and the Ergun equation, it is close to the length mean diameter when the particle Reynolds number is lower than 7, however, it has the value between the length mean diameter and the area mean diameter when the particle

  16. Research in elementary particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, L.E.; Schnitzer, H.J.; Bensinger, J.R.; Blocker, C.A.

    1992-01-01

    This report discusses research in the following areas of high energy physics: B meson mixing; CDF response to low energy jets; jet scaling behavior; search for pair produced leptoquarks at CDF; SSC program; quantum field theory; and neural networks. (LSP).

  17. A Short-Term, Quasi-Experimental Evaluation of D.A.R.E.'s Revised Elementary School Curriculum

    Science.gov (United States)

    Vincus, Amy A.; Ringwalt, Chris; Harris, Melissa S.; Shamblen, Stephen R.

    2010-01-01

    We present the short-term results of a quasi-experimental evaluation of the revised D. A. R. E. (Drug Abuse Resistance Education) curriculum. Study outcomes examined were D. A. R. E.'s effects on three substances, namely students' lifetime and 30-day use of tobacco, alcohol, and marijuana, as well as their school attendance and academic…

  18. First experimental comparison between the Cartesian and the Lissajous trajectory for magnetic particle imaging

    Science.gov (United States)

    Werner, F.; Gdaniec, N.; Knopp, T.

    2017-05-01

    Magnetic particle imaging (MPI) is a quantitative imaging modality that allows us to determine the distribution of superparamagnetic nanoparticles. Sampling is achieved by moving a field-free point (FFP) along a specific trajectory through the volume of interest. The magnetic material that lies along the path or in the close vicinity of the FFP changes its magnetization and induces a voltage in the surrounding receiver coils. Various trajectories for the FFP are conceivable, but most experimental MPI scanners either use a Cartesian or a Lissajous sampling trajectory. For the first time, this study compares both sampling methods experimentally using an MPI scanner that allows us to implement both sampling patterns. By default, the scanner is capable of scanning 2D and 3D field of views using a Lissajous trajectory. But since it also has a 1D mode, it is possible to perform Cartesian measurements by shifting the 1D scan line in a perpendicular direction to the FFP movement using the focus field. These line scans are jointly reconstructed to obtain a 2D image. In a further step, the unidirectional Cartesian trajectory is improved by interchanging the excitation and the focus-field direction leading to a bidirectional Cartesian trajectory. Our findings reveal similar results for the bidirectional Cartesian and Lissajous trajectory concerning the overall image quality and sensitivity. In a more detailed view, the bidirectional Cartesian trajectory achieves a slightly higher spatial center resolution, whereas the Lissajous trajectory is more efficient regarding the temporal resolution since less acquisition time is needed to reach an adequate image quality.

  19. Elementary particles. From the atoms via the Standard Model until the Higgs boson. 2. ed.; Elementare Teilchen. Von den Atomen ueber das Standard-Modell bis zum Higgs-Boson

    Energy Technology Data Exchange (ETDEWEB)

    Bleck-Neuhaus, Joern [Bremen Univ. (Germany)

    2013-07-01

    The current state of knowledge of nuclear and elementary-particle physics has a checkered history, often characterized by shocking new concept formations, which also opens up to the present day students of physics only with difficulty. This book uses those controversial yet educational development in order to enable learners to improve access to the new concepts. It helps to understand how the physical picture of the smallest particles is today, and why it is so and not otherwise originated: Beginning in the detection of the atoms up to the current standard model of elementary-particle physics and the Higgs boson. So readers gain an impression of that great field, which is originated in the constant interplay between established theoretical models, confirmatory or contradictory findings, sometimes controversial new concept formations, and improved experiments - a process, that surely continues in the future. Guideline of the presentation is a comprehensible also in detail as possible reasoning argumentation. Students of physics before their B.Sc. degree will thus be able to acquire knowledge of the subatomic physics relating to general knowledge in their field. Also for physics teachers at schools or colleges, this new representation should be interesting. The second edition has been updated to the newest state of knowledge, in particular first results of the LHC have been incorporated.

  20. Experimental and analytical characterization of the 3D motion of particles in acoustofluidic devices

    DEFF Research Database (Denmark)

    Rossi, M.; Barnkob, Rune; Augustsson, P.

    2012-01-01

    . Astigmatism Particle Tracking Velocimetry (APTV) was used to measure the three-dimensional trajectories, velocities and accelerations of the particles. The experiments show how the acoustic radiation force dominates for the large 5-µm particles, whereas the drag force from the acoustic streaming dominates...

  1. W.K.H. Panofsky Prize in Experimental Particle Physics Lecture: The making of GLAST: Being creative with experimental particle physics

    Science.gov (United States)

    Atwood, William

    2012-03-01

    The extension of astrophysical observations to gamma-ray energies requires the utilization of detectors invented and developed for the pursuit of High Energy Particle Physics. GLAST is the result of a close collaboration between the astrophysics and the HEP communities. The exceedingly small signal-to-noise (cosmic rays) ratio coupled with the need for the best angular resolution possible presented a host of problems. How these were successfully met and the resulting instrument and its science are reviewed.

  2. Experimental Investigation on Modified Solar Still Using Nano Particles and Water Sprinkler Attachment

    Science.gov (United States)

    Gupta, Bhupendra; Kumar, Anil; Baredar, Prashant V.

    2017-08-01

    The experimental investigation has been done in the month of April 2015 for climate condition of Jabalpur, Madhya Pradesh, India (latitude 23o18ˈN; Longitude 79o 95ˈE) during full day, 06.00 AM to 06:00 PM. The performance of the solar still with modification of water flow over the glass cover (sprinkler attachment) and nano particles (cuprous oxide) in basin water has been observed, recorded and compared with conventional still. It has been found that the collection of pure water in modified solar sill was 4000 ml/(m2-day) as compared to 2900 ml/(m2-day) in conventional solar still. The efficiency of 34% and 22% has been obtained for modified solar still and conventional still respectively. With design amendments, increase in overall effectiveness was found to be 54.54 %. The computed cost of pure water produced in modified still is expected to (INR) Rs.0.98/liter, in view of 12 yrs life of the solar still.

  3. Contribution to the study of elementary particles in experiments involving accelerators; Contribution a l'etude des constituants elementaires aupres des accelerateurs

    Energy Technology Data Exchange (ETDEWEB)

    Baldisseri, A

    2006-05-15

    This document reviews the theoretical, experimental and technical achievements of the author since the beginning of his scientific career. Works in 5 fields have been highlighted: 1) rare decays of the {eta} meson, 2) neutrino oscillations in NOMAD experiment, 3) quark and gluon plasma, 4) the PHENIX experiment at RHIC, and 5) the ALICE experiment in LHC. The PHENIX experiment was dedicated to the accurate measuring of photons and dileptons (particularly J/{psi}, {psi}' resonances) produced in heavy ion collisions. The ALICE experiment is devoted to the study of the quark gluon plasma. Its detector must be able to detect charged particles with a broad range of transverse momenta (from 100 MeV/c to 100 GeV/c). This document presented before an academic board will allow his author to manage research works and particularly to tutor thesis students.

  4. Elementary algebra

    CERN Document Server

    McKeague, Charles P

    1981-01-01

    Elementary Algebra 2e, Second Edition focuses on the basic principles, operations, and approaches involved in elementary algebra. The book first tackles the basics, linear equations and inequalities, and graphing and linear systems. Discussions focus on the substitution method, solving linear systems by graphing, solutions to linear equations in two variables, multiplication property of equality, word problems, addition property of equality, and subtraction, addition, multiplication, and division of real numbers. The manuscript then examines exponents and polynomials, factoring, and rational e

  5. Elementary algebra

    CERN Document Server

    McKeague, Charles P

    1986-01-01

    Elementary Algebra, Third Edition focuses on the basic principles, operations, and approaches involved in elementary algebra. The book first ponders on the basics, linear equations and inequalities, and graphing and linear systems. Discussions focus on the elimination method, solving linear systems by graphing, word problems, addition property of equality, solving linear equations, linear inequalities, addition and subtraction of real numbers, and properties of real numbers. The text then takes a look at exponents and polynomials, factoring, and rational expressions. Topics include reducing ra

  6. Experimental study on solids circulation patterns and bubble behavior using particle imagevelocimetry combined with digital image analysis

    NARCIS (Netherlands)

    Laverman, J.A.; Roghair, Ivo; van Sint Annaland, M.; Kuipers, J.A.M.

    2008-01-01

    The hydrodynamics, viz. the solids circulation patterns and bubble behavior, of a freely bubbling gas-solid fluidized bed has been investigated experimentally using Particle Image Velocimetry (PIV) combined with Digital Image Analysis (DIA). Coupling of these non-invasive measuring techniques allows

  7. Hygroscopic Fine Mode Particle Deposition on Electronic Circuitsand Resulting Degradation of Circuit Performance: An ExperimentalStudy

    Energy Technology Data Exchange (ETDEWEB)

    Litvak, Andres; Gadgil, A.; Fisk, W.J.

    1998-03-01

    A portion of electronic equipment failures is a consequenceof particle deposition on electronic circuits in normal indoorenvironments. Deposited hygroscopic particles reduce the electricalisolation (EI) between conductors. In laboratory experiments, weinvestigated the mechanisms, locations, and effects of particledeposition on electronic circuits with surface mounted chips (SMCs) andalso on small television sets. One set of electronics was exposed for 281h to an unusually high concentration of artificially-generated ammoniumsulfate particles while a second set (experimental controls) was exposedto normal indoor particles. The particle mass concentration in thehigh-exposure chamber was 500 times higher than normal. Televisionreliability was observed and the changes in EI between adjacent legs ofSMCs were measured. The experiments demonstrate the strong influence ofelectrostatic forces on the locations and rates of particle deposition.Although televisions did not fail after exposure to concentratedaerosols, the EI between adjacent legs of the SMCs was, in many cases,greatly diminished. Relative humidity had a very strong influence on themagnitude of EI. A qualitative explanation of the mechanisms of particledeposition and circuit degradation is proposed, including the role offibers. Finally, a potential method to reduce particle deposition onelectronic components is discussed.

  8. Elementary Goldstone Higgs Boson and Dark Matter

    DEFF Research Database (Denmark)

    Alanne, Tommi; Gertov, Helene; Sannino, Francesco

    2015-01-01

    We investigate a perturbative extension of the Standard Model featuring elementary pseudo-Goldstone Higgs and dark matter particles. These are two of the five Goldstone bosons parametrising the SU(4)/Sp(4) coset space. They acquire masses, and therefore become pseudo-Goldstone bosons, due...... of the theory, the quantum corrections are precisely calculable. The remaining pseudo-Goldstone boson is identified with the dark matter candidate because it is neutral with respect to the Standard Model and stable. By a direct comparison with the Large Hadron Collider experiments, the model is found...... to be phenomenologically viable. Furthermore the dark matter particle leads to the observed thermal relic density while respecting the most stringent current experimental constraints....

  9. Experimental Investigation of Nascent Soot Physical Properties and The Influence on Particle Morphology and Growth

    Science.gov (United States)

    Lieb, Sydnie Marie

    Soot released to the atmosphere is a dangerous pollutant for human health and the environment. Understanding the physical properties and surface properties of these particles is important to properly explaining the growth of soot particles in flames as well as their interactions with other particles and gases in the environment. Particles below 15 nm in diameter, nascent soot particles, dominate the early growth stages of soot formation; previously these particles were characterized as hard graphitic spheres. New evidence derived from the current dissertation work, to a large extent, challenges this prior characterization. This dissertation study begins by revisiting the use of atomic force microscope (AFM) as a tool to investigate the structural properties of nascent soot. The impact of tip artifacts, which are known to complicate measurements of features below 10 nm in diameter, are carefully considered so as to provide a concise interpretation of the morphology of nascent soot as seen by AFM. The results of the AFM morphology collaborate with earlier photo- and thermal-fragmentation particle mass spectrometry and Fourier transform infrared spectroscopy that nascent soot is not a graphitized carbon material and that they are not spherical. Furthermore, phase mode imaging is introduced as a method to investigate the physical properties of nascent soot particles in a greater detail and finer resolution. The helium ion microscope (HIM) has been identified as a useful technique for the imaging of nascent soot. Using this imaging method nascent soot particles were imaged with a high resolution that had not been obtained by prior techniques. The increased contrast provides a closer look at the nascent soot particles and further suggested that these particles are not as structurally homogeneous as previously thought. Geometric shape analysis was performed to characterize the particles in terms of sphericity, circularity, and fractal dimension. The geometric analysis

  10. Hardening of particle/oil/water suspensions due to capillary bridges: Experimental yield stress and theoretical interpretation.

    Science.gov (United States)

    Danov, Krassimir D; Georgiev, Mihail T; Kralchevsky, Peter A; Radulova, Gergana M; Gurkov, Theodor D; Stoyanov, Simeon D; Pelan, Eddie G

    2018-01-01

    Suspensions of colloid particles possess the remarkable property to solidify upon the addition of minimal amount of a second liquid that preferentially wets the particles. The hardening is due to the formation of capillary bridges (pendular rings), which connect the particles. Here, we review works on the mechanical properties of such suspensions and related works on the capillary-bridge force, and present new rheological data for the weakly studied concentration range 30-55 vol% particles. The mechanical strength of the solidified capillary suspensions, characterized by the yield stress Y, is measured at the elastic limit for various volume fractions of the particles and the preferentially wetting liquid. A quantitative theoretical model is developed, which relates Y with the maximum of the capillary-bridge force, projected on the shear plane. A semi-empirical expression for the mean number of capillary bridges per particle is proposed. The model agrees very well with the experimental data and gives a quantitative description of the yield stress, which increases with the rise of interfacial tension and with the volume fractions of particles and capillary bridges, but decreases with the rise of particle radius and contact angle. The quantitative description of capillary force is based on the exact theory and numerical calculation of the capillary bridge profile at various bridge volumes and contact angles. An analytical formula for Y is also derived. The comparison of the theoretical and experimental strain at the elastic limit reveals that the fluidization of the capillary suspension takes place only in a deformation zone of thickness up to several hundred particle diameters, which is adjacent to the rheometer's mobile plate. The reported experimental results refer to water-continuous suspension with hydrophobic particles and oily capillary bridges. The comparison of data for bridges from soybean oil and hexadecane surprisingly indicate that the yield strength is

  11. An innovative experimental setup for Large Scale Particle Image Velocimetry measurements in riverine environments

    Science.gov (United States)

    Tauro, Flavia; Olivieri, Giorgio; Porfiri, Maurizio; Grimaldi, Salvatore

    2014-05-01

    Large Scale Particle Image Velocimetry (LSPIV) is a powerful methodology to nonintrusively monitor surface flows. Its use has been beneficial to the development of rating curves in riverine environments and to map geomorphic features in natural waterways. Typical LSPIV experimental setups rely on the use of mast-mounted cameras for the acquisition of natural stream reaches. Such cameras are installed on stream banks and are angled with respect to the water surface to capture large scale fields of view. Despite its promise and the simplicity of the setup, the practical implementation of LSPIV is affected by several challenges, including the acquisition of ground reference points for image calibration and time-consuming and highly user-assisted procedures to orthorectify images. In this work, we perform LSPIV studies on stream sections in the Aniene and Tiber basins, Italy. To alleviate the limitations of traditional LSPIV implementations, we propose an improved video acquisition setup comprising a telescopic, an inexpensive GoPro Hero 3 video camera, and a system of two lasers. The setup allows for maintaining the camera axis perpendicular to the water surface, thus mitigating uncertainties related to image orthorectification. Further, the mast encases a laser system for remote image calibration, thus allowing for nonintrusively calibrating videos without acquiring ground reference points. We conduct measurements on two different water bodies to outline the performance of the methodology in case of varying flow regimes, illumination conditions, and distribution of surface tracers. Specifically, the Aniene river is characterized by high surface flow velocity, the presence of abundant, homogeneously distributed ripples and water reflections, and a meagre number of buoyant tracers. On the other hand, the Tiber river presents lower surface flows, isolated reflections, and several floating objects. Videos are processed through image-based analyses to correct for lens

  12. EXPERIMENTAL STUDY ON THE DYNAMICS OF A SPOUTED BED WITH PARTICLE FEED THROUGH THE BASE

    Directory of Open Access Journals (Sweden)

    L.A.P. Freitas

    1997-09-01

    Full Text Available A draft tube spouted bed was constructed with a screw conveyor attached at its base to feed particles into the column. Results on fluid dynamic characteristics and particle movement in this system are presented and discussed. Two methods of measuring the superficial air velocity in the annular region are compared. The particle velocity and recirculation rates have been determined in a half column with transparent walls. The effects of the particle feed rate, air flow rate and bed height on the spouted bed dynamics have been analysed and compared with those in the literature. Keywords: Spouted bed, continuous feed, dynamics

  13. Effect of filler particles on surface roughness of experimental composite series

    Directory of Open Access Journals (Sweden)

    Hanadi Yousif Marghalani

    2010-02-01

    Full Text Available OBJECTIVE: The purpose of this study was to evaluate the effect of different filler sizes and shapes on the surface roughness of experimental resin-composite series. MATERIAL AND METHODS: Thirty-three disc-shaped specimens of the series (Spherical-RZD 102, 105, 106, 107, 114 and Irregular-RZD 103, 108, 109, 110, 111, 112 were prepared in a split Teflon mold and irradiated with an halogen light-curing unit (450 mW/cm² for 40 s at both top and bottom surfaces. The specimens were stored for 3 months in distilled water. The surface roughness values in form of surface finish-vertical parameter (Ra, maximum roughness depth (Rmax and horizontal roughness parameter (Sm were recorded using a contact profilometer. The data were analyzed by one-way ANOVA and the means were compared by Scheffé post-hoc test (a=0.05. RESULTS: The lowest surface roughness (Ra was observed in S-100 (0.079±0.013, while the roughest surface was noted in I-450/700/1000 (0.125±0.011 and I-450/1000 (0.124±0.004. The spherical-shape series showed the smoothest surface finish compared to the irregular-shape ones with higher significant difference (p>0.05. The vertical surface roughness parameter (Ra values increased as the filler size increased yielding a linear relation (r²=0.82. On the contrary, the horizontal parameter (Sm was not significantly affected by the filler size (r²=0.24 as well as the filler shape. CONCLUSIONS: Filler particle's size and shape have a great effect on the surface roughness parameters of these composite series.

  14. Experimentally Investigating the Effect of Temperature Differences in the Particle Deposition Process on Solar Photovoltaic (PV Modules

    Directory of Open Access Journals (Sweden)

    Yu Jiang

    2016-10-01

    Full Text Available This paper reports an experimental investigation of the dust particle deposition process on solar photovoltaic (PV modules with different surface temperatures by a heating plate to illustrate the effect of the temperature difference (thermophoresis between the module surface and the surrounding air on the dust accumulation process under different operating temperatures. In general, if the temperature of PV modules is increased, the energy conversion efficiency of the modules is decreased. However, in this study, it is firstly found that higher PV module surface temperature differences result in a higher energy output compared with those modules with lower temperature differences because of a reduced accumulation of dust particles. The measured deposition densities of dust particles were found to range from 0.54 g/m2 to 0.85 g/m2 under the range of experimental conditions and the output power ratios were found to increase from 0.861 to 0.965 with the increase in the temperature difference from 0 to 50 °C. The PV module with a higher temperature difference experiences a lower dust density because of the effect of the thermophoresis force arising from the temperature gradient between the module surface and its surrounding air. In addition, dust particles have a significant impact on the short circuit current, as well as the output power. However, the influence of particles on open circuit voltage can be negligible.

  15. Calculation and experimental study on high-speed impact of heat-resistant coating materials with a meteoric particle

    Science.gov (United States)

    Glazunov, Anatoly; Ishchenko, Aleksandr; Afanas'eva, Svetlana; Belov, Nikolai; Burkin, Viktor; Rogaev, Konstantin; Yugov, Nikolai

    2016-01-01

    The given article presents the conducted calculation and experimental study on destruction of heat-resistant coating material of an aircraft in the process of high-speed interaction of the steel spherical projectile. The projectile is imitating a meteoric particle. The study was conducted in the wide range of velocities. The mathematical behavioral model of heat-resistant coating under high-speed impact was developed. The interaction of ameteoric particle with an element of the protective structure has especially individual character and depends on impact velocity and angle, materials of the interacting solids.

  16. CrossRef Antiproton Flux, Antiproton-to-Proton Flux Ratio, and Properties of Elementary Particle Fluxes in Primary Cosmic Rays Measured with the Alpha Magnetic Spectrometer on the International Space Station

    CERN Document Server

    Aguilar, M; Alpat, B; Ambrosi, G; Arruda, L; Attig, N; Aupetit, S; Azzarello, P; Bachlechner, A; Barao, F; Barrau, A; Barrin, L; Bartoloni, A; Basara, L; Başeǧmez-du Pree, S; Battarbee, M; Battiston, R; Bazo, J; Becker, U; Behlmann, M; Beischer, B; Berdugo, J; Bertucci, B; Bindi, V; Boella, G; de Boer, W; Bollweg, K; Bonnivard, V; Borgia, B; Boschini, M  J; Bourquin, M; Bueno, E  F; Burger, J; Cadoux, F; Cai, X  D; Capell, M; Caroff, S; Casaus, J; Castellini, G; Cernuda, I; Cervelli, F; Chae, M  J; Chang, Y  H; Chen, A  I; Chen, G  M; Chen, H  S; Cheng, L; Chou, H  Y; Choumilov, E; Choutko, V; Chung, C  H; Clark, C; Clavero, R; Coignet, G; Consolandi, C; Contin, A; Corti, C; Coste, B; Creus, W; Crispoltoni, M; Cui, Z; Dai, Y  M; Delgado, C; Della Torre, S; Demirköz, M  B; Derome, L; Di Falco, S; Dimiccoli, F; Díaz, C; von Doetinchem, P; Dong, F; Donnini, F; Duranti, M; D'Urso, D; Egorov, A; Eline, A; Eronen, T; Feng, J; Fiandrini, E; Finch, E; Fisher, P; Formato, V; Galaktionov, Y; Gallucci, G; García, B; García-López, R  J; Gargiulo, C; Gast, H; Gebauer, I; Gervasi, M; Ghelfi, A; Giovacchini, F; Goglov, P; Gómez-Coral, D  M; Gong, J; Goy, C; Grabski, V; Grandi, D; Graziani, M; Guerri, I; Guo, K  H; Habiby, M; Haino, S; Han, K  C; He, Z  H; Heil, M; Hoffman, J; Hsieh, T  H; Huang, H; Huang, Z  C; Huh, C; Incagli, M; Ionica, M; Jang, W  Y; Jinchi, H; Kang, S  C; Kanishev, K; Kim, G  N; Kim, K  S; Kirn, Th; Konak, C; Kounina, O; Kounine, A; Koutsenko, V; Krafczyk, M  S; La Vacca, G; Laudi, E; Laurenti, G; Lazzizzera, I; Lebedev, A; Lee, H  T; Lee, S  C; Leluc, C; Li, H  S; Li, J  Q; Li, Q; Li, T  X; Li, W; Li, Z  H; Li, Z  Y; Lim, S; Lin, C  H; Lipari, P; Lippert, T; Liu, D; Liu, Hu; Lu, S  Q; Lu, Y  S; Luebelsmeyer, K; Luo, F; Luo, J  Z; Lv, S  S; Majka, R; Mañá, C; Marín, J; Martin, T; Martínez, G; Masi, N; Maurin, D; Menchaca-Rocha, A; Meng, Q; Mo, D  C; Morescalchi, L; Mott, P; Nelson, T; Ni, J  Q; Nikonov, N; Nozzoli, F; Nunes, P; Oliva, A; Orcinha, M; Palmonari, F; Palomares, C; Paniccia, M; Pauluzzi, M; Pensotti, S; Pereira, R; Picot-Clemente, N; Pilo, F; Pizzolotto, C; Plyaskin, V; Pohl, M; Poireau, V; Putze, A; Quadrani, L; Qi, X  M; Qin, X; Qu, Z  Y; Räihä, T; Rancoita, P  G; Rapin, D; Ricol, J  S; Rodríguez, I; Rosier-Lees, S; Rozhkov, A; Rozza, D; Sagdeev, R; Sandweiss, J; Saouter, P; Schael, S; Schmidt, S  M; Schulz von Dratzig, A; Schwering, G; Seo, E  S; Shan, B  S; Shi, J  Y; Siedenburg, T; Son, D; Song, J  W; Sun, W  H; Tacconi, M; Tang, X  W; Tang, Z  C; Tao, L; Tescaro, D; Ting, Samuel C  C; Ting, S  M; Tomassetti, N; Torsti, J; Türkoğlu, C; Urban, T; Vagelli, V; Valente, E; Vannini, C; Valtonen, E; Vázquez Acosta, M; Vecchi, M; Velasco, M; Vialle, J  P; Vitale, V; Vitillo, S; Wang, L  Q; Wang, N  H; Wang, Q  L; Wang, X; Wang, X  Q; Wang, Z  X; Wei, C  C; Weng, Z  L; Whitman, K; Wienkenhöver, J; Willenbrock, M; Wu, H; Wu, X; Xia, X; Xiong, R  Q; Xu, W; Yan, Q; Yang, J; Yang, M; Yang, Y; Yi, H; Yu, Y  J; Yu, Z  Q; Zeissler, S; Zhang, C; Zhang, J; Zhang, J  H; Zhang, S  D; Zhang, S  W; Zhang, Z; Zheng, Z  M; Zhu, Z  Q; Zhuang, H  L; Zhukov, V; Zichichi, A; Zimmermann, N; Zuccon, P

    2016-01-01

    A precision measurement by AMS of the antiproton flux and the antiproton-to-proton flux ratio in primary cosmic rays in the absolute rigidity range from 1 to 450 GV is presented based on 3.49×105 antiproton events and 2.42×109 proton events. The fluxes and flux ratios of charged elementary particles in cosmic rays are also presented. In the absolute rigidity range ∼60 to ∼500  GV, the antiproton p¯, proton p, and positron e+ fluxes are found to have nearly identical rigidity dependence and the electron e− flux exhibits a different rigidity dependence. Below 60 GV, the (p¯/p), (p¯/e+), and (p/e+) flux ratios each reaches a maximum. From ∼60 to ∼500  GV, the (p¯/p), (p¯/e+), and (p/e+) flux ratios show no rigidity dependence. These are new observations of the properties of elementary particles in the cosmos.

  17. Theoretical and experimental studies of elementary physics. Annual technical progress report, November 1, 1992--October 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Bodek, A.; Ferbel, T.; Melissinos, A.C.; Slattery, P.; Tipton, P.; Das, A.; Hagen, C.R.; Rajeev, S.G.; Okubo, S.; Orr, L.

    1993-05-01

    The various components of the high-energy physics research program at the University of Rochester are presented. (I)Fixed-target experimentation at FNAL includes studies of direct photon production by p and {pi} on H, Be, and Cu, and hybrid mesons and other physics issues in Coulomb excitation at high energies. (II)The status of the GEM (Gammas, Electrons, and Muons) Experiment at the SSC is given. (III)The D-Zero experiment at FNAL is reviewed. (IV)Deep inelastic lepton--nucleon scattering experiments are summarized: electron scattering experiments at SLAC, FNAL neutrino quad triplet runs, FNAL neutrino sign selected experiments, and SDC cosmic ray test and test beam calibration. (V)Studies of nonlinear QED at SLAC concentrated on a study of QED at critical field strength in intense laser--high-energy electron collisions. (VI)Development work on the Collider Detector at Fermilab (CDF) emphasized the CDF silicon vertex detector, the end plug calorimeter, and the SDC tile/fiber calorimetry. (VII)The theoretical physics effort is sketched.

  18. Experimental investigation of mesoscopic heterogeneous motion of laser-activated self-propelling Janus particles in suspension

    Science.gov (United States)

    Io, Chong-Wai; Chen, Tzu-Yin; Yeh, Jai-Wei; Cai, Sin-Cen

    2017-12-01

    The mesoscopic collective motion of self-propelling active particle suspension is experimentally investigated. The active particles are silica micro spheres with Au hemisphere coating, and their propelling strength is activated by laser irradiation. The suspension is driven from equilibrium to near equilibrium and far from equilibrium by tuning the excitation laser intensity. By use of the long-term particle tracking technique, the time evolution of a large amount of active particles is resolvable. For low laser intensity, the suspension is driven to near equilibrium state with homogeneous superdiffusion motion. The strength of enhanced superdiffusion is monotonically related to the laser intensity. For high laser intensity, the motility-induced phase separation with the coexistence of dense cluster and very dilute individual particle are observed. It leads to highly heterogeneous dynamic with less mobile jammed cluster and fast-moving particles and subsequently suppresses the enhanced superdiffusion. Such heterogeneous dynamics is similar to many far from equilibrium systems. Finally, the degree away from equilibrium (Gaussian dynamics) triggered by propelling strength is quantified by non-Gaussian parameters.

  19. Soot Particle Optical Properties: a Comparison between Numerical Calculations and Experimental Data Collected during the Boston College Experiment

    Science.gov (United States)

    Sharma, N.; Mazzoleni, C.; China, S.; Dubey, M. K.; Onasch, T. B.; Cross, E. S.; Davidovits, P.; Wrobel, W.; Ahern, A.; Schwarz, J. P.; Spackman, J. R.; Lack, D. A.; Massoli, P.; Freedman, A.; Olfert, J. S.; Freitag, S.; Sedlacek, A. J.; Cappa, C. D.; Subramanian, R.

    2010-12-01

    A black carbon instrument inter-comparison study was conducted in July 2008 at Boston College to measure the optical, physical and chemical properties of laboratory generated soot under controlled conditions [1]. The physical, chemical and optical properties were measured on size-selected particles for: 1. Nascent soot particles 2. Nascent- denuded soot particles 3. Soot particles coated with sulfuric acid or DOS (dioctyl sebacate) across a range of coating thicknesses 4. Coated and then denuded soot particles. Instruments involved in the inter-comparison study fell into two broad categories: a) mass-based instruments and b) optically-based instruments. During this experiment, 7 mass-based and 9 optically-based instruments were deployed. Absorption scattering and extinction measurements were carried out in combination with mass-based instruments in order to obtain absorption, scattering and extinction coefficients for coated and denuded soot particles as a function of their mass, size and coating thickness. Particle samples were also collected on nuclepore filters to perform Scanning Electron Microscopy (SEM) analysis. The images obtained with the SEM elucidated the changes in particle morphology upon coating and denuding. The images were also used to determine morphological parameters for single soot aggregates (e.g. monomers number and diameter) used in the numerical estimation of aerosol optical properties. With the data collected during the experiment, we carry out a comparative study of the optical properties of soot particles obtained experimentally with those calculated using the two most commonly used numerical approximations (Rayleigh-Debye-Gans (RDG) theory and Mie theory). Thus we validate the degree of agreement between theoretical models and experimental results. The laboratory optical, mass, size and morphological data can be used to elucidate the impact of these parameters on radiative forcing by atmospheric soot [2, 3]. References: 1. Cross, E. S

  20. Experimental Exploration of Particle-Scale Bed Load Transport and Near-Bed Fluid Velocities

    Science.gov (United States)

    Fathel, S. L.; Furbish, D. J.; Schmeeckle, M. W.

    2016-12-01

    Bed load sediment particles move as complex motions over the surface of a stream bed, accelerating and decelerating in response to the near-bed turbulence and due to particle-bed interactions. Using high-speed imagery of coarse sand particles on a planer bed surface, we track individual particle motions from start to stop, combined with measurements of near-bed fluid velocities to better characterize the relationship between these properties. These simultaneous measurements provide an initial step towards describing the dynamic relationship between the fluid and particle entrainment on the grain-scale. We start with an Eulerian a priori method wherein we grid the analyzed area and compare the fluid velocity time series to the entrainment time series within each grid space. We progressively increase the size of the grids and monitor the correlation between the two time series. We then use an a posteriori method that focuses on the fluid velocities in the vicinity of entrained particles both at the moment of entrainment and prior to the initiation of motion. We further our analysis of the relationship between particle motions and the near-bed fluid using detailed measurements of particle motions to calibrate estimates of the sediment load using a pixel differencing method. This allows us to examine connections between the fluid and particle activity over many frames rather than over the limited, manually tracked time period. Furthermore, this allows us to empirically define a distribution of particle wait times, or the duration of time between successive entrainment events over a set area, which acts to determine the transport intensity. Preliminary results suggest that there is not a clear correlation between near-bed fluid velocities and particle entrainment. In absence of a correlation we find that (1) we must think more deeply about collective entrainment and how it 'works', and (2) we must consider how the microstructure of the particles on the bed act to set up

  1. Experimental study of forces on freely moving spherical particles during resuspension into turbulent flow

    CERN Document Server

    Traugott, Hadar

    2015-01-01

    Turbulent resuspension is the process of lifting solid particles from the bottom by turbulent flow, ubiquitous in natural and industrial problems. The process is a sequence of events that start with an incipient motion when the particle is dislodged from its place, continue as sliding or rolling along the surface, and ending with the detachment of the particle from the surface and lifting it up into the flow. In this study we measure in details the motion of freely moving solid spherical particles along the bottom smooth wall under an oscillating grid turbulence and track them through the lift-off events. We measure simultaneously the Lagrangian trajectories of the particles and the flow tracers around them. We estimate the local flow parameters and extract the different force terms that act on a particle. For the particles of the diameter comparable with the Kolmogorov length scale, either sliding or rolling along the smooth wall under a zero-mean turbulent flow, we find that: i) the lift force is a dominant...

  2. Daily micro particle distribution of an experimental recirculating aquaculture system – A case study

    DEFF Research Database (Denmark)

    Fernandes, Paulo; Pedersen, Lars-Flemming; Pedersen, Per Bovbjerg

    2014-01-01

    particle removal above 60 m (31% reductionin the relative contribution from each size by the drum filter) per passage, but marginal productionand removal of particles throughout the rest of the system further support the ˇ-value stability andconsequent PSD equilibrium.The results showed a stable ˇ......-value in the mature RAS. The ˇ-value is influenced by the containedcompartments and system configuration, and may be used as a system performance-predicting tool.Mechanisms of particle influence on system and fish performance should be addressed in future studies,and are herein discussed...

  3. Searches for Fractionally Charged Particles: What Should Be Done Next?

    Energy Technology Data Exchange (ETDEWEB)

    Perl, Martin L.; /SLAC

    2009-01-15

    Since the initial measurements of the electron charge a century ago, experimenters have faced the persistent question as to whether elementary particles exist that have charges that are fractional multiples of the electron charge. I concisely review the results of the last 50 years of searching for fractional charge particles with no confirmed positive results. I discuss the question of whether more searching is worthwhile?

  4. Long-term aging and degradation of microplastic particles: Comparing in situ oceanic and experimental weathering patterns.

    Science.gov (United States)

    Brandon, Jennifer; Goldstein, Miriam; Ohman, Mark D

    2016-09-15

    Polypropylene, low-density polyethylene, and high-density polyethylene pre-production plastic pellets were weathered for three years in three experimental treatments: dry/sunlight, seawater/sunlight, and seawater/darkness. Changes in chemical bond structures (hydroxyl, carbonyl groups and carbon-oxygen) with weathering were measured via Fourier Transform Infrared (FTIR) spectroscopy. These indices from experimentally weathered particles were compared to microplastic particles collected from oceanic surface waters in the California Current, the North Pacific Subtropical Gyre, and the transition region between the two, in order to estimate the exposure time of the oceanic plastics. Although chemical bonds exhibited some nonlinear changes with environmental exposure, they can potentially approximate the weathering time of some plastics, especially high-density polyethylene. The majority of the North Pacific Subtropical Gyre polyethylene particles we measured have inferred exposure times>18months, with some >30months. Inferred particle weathering times are consistent with ocean circulation models suggesting a long residence time in the open ocean. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Theoretical and experimental radiation effectiveness of the free radical dosimeter alanine to irradiation with heavy charged particles

    DEFF Research Database (Denmark)

    Hansen, Jørgen-Walther; Olsen, K. J.

    1985-01-01

    -LET radiations of 60Co .gamma. rays, 4 and 16 MV X rays, and 6, 10, and 20 MeV electrons was compared with theoretical RE values derived from a model based on track structure theory of heavy charged particles. The ion beams covered a range in initial LET of 27-20,200 MeVcm2/g, and the experimental RE decreased...

  6. Development and experimental evaluation of an optical sensor for aerosol particle characterization

    Energy Technology Data Exchange (ETDEWEB)

    Somesfalean, G.

    1998-03-01

    A sensor for individual aerosol particle characterization, based on a single-mode semiconductor laser coupled to an external cavity is presented. The light emitting semiconductor laser acts as a sensitive optical detector itself, and the whole system has the advantage of using conventional optical components and providing a compact set-up. Aerosol particles moving through the sensing volume, which is located in the external cavity of a semiconductor laser, scatter and absorb light. Thereby they act as small disturbances on the electromagnetic field inside the dynamic multi-cavity laser system. From the temporal variation of the output light intensity, information about the number, velocity, size, and refractive index of the aerosol particles can be derived. The diffracted light in the near-forward scattering direction is collected and Fourier-transformed by a lens, and subsequently imaged on a CCD camera. The recorded Fraunhofer diffraction pattern provides information about the projected area of the scattering particle, and can thus be used to determine the size and the shape of aerosol particles. The sensor has been tested on fibers which are of interest in the field of working environment monitoring. The recorded output intensity variation has been analysed, and the relationship between the shape and the size of each fibre, and the resulting scattering profiles has been investigated. A simple one-dimensional model for the optical feedback variation due to the light-particle interaction in the external cavity is also discussed 34 refs, 26 figs, 6 tabs

  7. High-energy nuclear optics of polarized particles

    CERN Document Server

    Baryshevsky, Vladimir G

    2012-01-01

    The various phenomena caused by refraction and diffraction of polarized elementary particles in matter have opened up a new research area in the particle physics: nuclear optics of polarized particles. Effects similar to the well-known optical phenomena such as birefringence and Faraday effects, exist also in particle physics, though the particle wavelength is much less than the distance between atoms of matter. Current knowledge of the quasi-optical effects, which exist for all particles in any wavelength range (and energies from low to extremely high), will enable us to investigate different properties of interacting particles (nuclei) in a new aspect. This pioneering book will provide detailed accounts of quasi-optical phenomena in the particle polarization, and will interest physicists and professionals in experimental particle physics.

  8. Experimental determination of the oral bioavailability and bioaccessibility of lead particles

    Directory of Open Access Journals (Sweden)

    Deshommes Elise

    2012-11-01

    Full Text Available Abstract In vivo estimations of Pb particle bioavailability are costly and variable, because of the nature of animal assays. The most feasible alternative for increasing the number of investigations carried out on Pb particle bioavailability is in vitro testing. This testing method requires calibration using in vivo data on an adapted animal model, so that the results will be valid for childhood exposure assessment. Also, the test results must be reproducible within and between laboratories. The Relative Bioaccessibility Leaching Procedure, which is calibrated with in vivo data on soils, presents the highest degree of validation and simplicity. This method could be applied to Pb particles, including those in paint and dust, and those in drinking water systems, which although relevant, have been poorly investigated up to now for childhood exposure assessment.

  9. Experimental research results of solid particle erosion resistance of blade steel with protective coating

    Science.gov (United States)

    Kachalin, G. V.; Mednikov, A. F.; Tkhabisimov, A. B.; Seleznev, L. I.

    2017-11-01

    The paper presents the results of metallographic studies and solid particle erosion tests of uncoated blade steel 20kH13 samples and samples with a protective coating based on chromium carbide (Cr-CrC) at a flow (air) velocity CA = 180 m/s, flow temperature tA = 25 °C, attack angle α = 30° and consumption of solid abrasive particles GP = 5·10-4 kg/s. It was found that the coating has a granular structure, a thickness is about 11 μm, the microhardness of the surface is 1520 ± 50 HV0.05. Processing of the obtained data by statistical analysis methods showed that the protective coating based on Cr-CrC increases the solid particle erosion resistance of the blade steel 20kH13 by the incubation-transitional period duration more than 2.5 times.

  10. The experimental basis for interpreting particle and magnetic fabrics of sheared till

    Science.gov (United States)

    Iverson, N.R.; Hooyer, T.S.; Thomason, J.F.; Graesch, M.; Shumway, J.R.

    2008-01-01

    Particle fabrics of basal tills may allow testing of the bed-deformation model of glacier flow, which requires high bed shear strains (>100). Field studies, however, have not yielded a systematic relationship between shear-strain magnitude and fabric development. To isolate this relationship four basal tills and viscous putty were sheared in a ring-shear device to strains as high as 714. Fabric was characterized within a zone of shear deformation using the long-axis orientations of fine-gravel and sand particles and the anisotropy of magnetic susceptibility (AMS) of small (???5-8 cm3) intact samples. Results indicate that till particles rotate toward the plane of shearing with long-axis orientations that become tightly clustered in the direction of shear (0??78 fabrics are attained at shear strains of 7-30, with no evidence of fabric weakening with further strain, regardless of the specific till or particle-size fraction under consideration. These results do not support the Jeffery model of particle rotation, which correctly describes particle rotation in the viscous putty but not in the tills, owing to fluid-mechanical assumptions of the model that are violated in till. The sensitivity of fabric development to shear-strain magnitude indicates that, for most till units where shear-strain magnitude is poorly known, attributing fabric variations to spatial differences in other variables, such as till thickness or water content, will be inherently speculative. Attributing fabric characteristics to particular basal till facies is uncertain because shear-strain magnitude is unlikely to be closely correlated to till facies. Weak or spatially variable fabrics, in the absence of post-depositional disturbance or major deviations from unidirectional simple shear, indicate that till has not been pervasively sheared to the high strains required by the bed-deformation model. Strong flow-parallel fabrics are a necessary but insufficient criterion for confirming the model

  11. Volcanic and stratospheric dust-like particles produced by experimental water-melt interactions

    Energy Technology Data Exchange (ETDEWEB)

    Wohletz, K.H.; McQueen, R.G.

    1984-10-01

    Commercially available Thermit (Al + Fe/sub 3/O/sub 4/) was ignited, forming a molten mixture of Al/sub 2/O/sub 3/ + Fe. The subsequent mixing of this melt with water in steel containers produced explosive interactions that were used to model hydrovolcanic activity. Debris collected from the experiments consisted of quenched Thermit particles ranging in size from < 1 ..mu..m to centimeters. Scanning electron microscopy of the debris showed spheroidal, irregular aggregates and blocky particle shapes that are very similar to hydrovolcanic ash, as well as some types of stratospheric dust and industrial fly ash. 27 references, 3 figures, 1 table.

  12. Volcanic and stratospheric dustlike particles produced by experimental water-melt interactions

    Science.gov (United States)

    Wohletz, K. H.; McQueen, R. G.

    1984-10-01

    Commercially available Thermit (Al + Fe3O4) was ignited, forming a molten mixture of Al2O3 + Fe. The subsequent mixing of this melt with water in steel containers produced explosive interactions that were used to model hydrovolcanic activity. Debris collected from the experiments consisted of quenched Thermit particles ranging in size from <1 μm to centimetres. Scanning electron microscopy of the debris showed spheroidal, irregular aggregates and blocky particle shapes that are very similar to hydrovolcanic ash, as well as some types of stratospheric dust and industrial fly ash.

  13. Experimental overview of collective flow with identified particles at RHIC and the LHC

    Directory of Open Access Journals (Sweden)

    Christakoglou Panos

    2015-01-01

    Full Text Available Anisotropic flow studies play a crucial role in improving our understanding of the behaviour and the nature of matter created in collisions of heavy ions. In particular, the study of elliptic flow (υ2 for identified particles can be used to constrain the initial conditions and the value of shear viscosity over entropy density ratio. It also allows to determine the role of the hadronic rescattering phase in the development of flow. In these proceedings I review the results from measurements of υ2 for identified particles from the RHIC and LHC heavy-ion physics programs.

  14. Experimental Probability in Elementary School

    Science.gov (United States)

    Andrew, Lane

    2009-01-01

    Concepts in probability can be more readily understood if students are first exposed to probability via experiment. Performing probability experiments encourages students to develop understandings of probability grounded in real events, as opposed to merely computing answers based on formulae.

  15. Experimentally determined human respiratory tract deposition of airborne particles at a busy street

    DEFF Research Database (Denmark)

    Löndahl, Jakob; Massling, Andreas; Swietlicki, Erik

    2009-01-01

    was measured with a novel setup in 9 healthy subjects breathing by mouth on the windward side of a busy street in Copenhagen, Denmark. The aerosol was characterized both at the curbside and, to obtain the background concentration, at rooftop level. Particle hygroscopicity, a key parameter affecting respiratory...

  16. Computed and experimental interactions between eddy structure and dispersed particles in developing free shear layers

    Energy Technology Data Exchange (ETDEWEB)

    Buckingham, A.C.; Siekhaus, W.J.; Keller, J.O.; Ellzey, J.; Hubbard, G.; Daily, J.W.

    1982-05-20

    We are investigating the interactive process between turbulent flow and dispersed phase particles. We are focusing on the mechanisms that appear to result in a reduction of local turbulent intensity and a corresponding reduction in wall heat transfer and subsequent wall erosion in turbulent solid propellant combustion flow. We apply computational simulations and physical experiments specialized to a developing free shear layer over a rearward facing step and over a parallel splitter plate. The flow configuration evolves in a two-dimensional, steady, combustion and non-combustion turbulent free shear mixing region, with and without particle additives. The computational simulations combine three basic components: gas phase Navier-Stokes solutions, Lagrange particle field solutions and a Monte Carlo technique for the random encounters, forces and accelerations between the two fields. We concentrate here on relatively large sized additive particles (of the order of tens of microns to 100 microns mean diameter). We examine their apparent influence in breaking up the larger, energy bearing eddy structures into smaller structures which are more readily dissipated.

  17. Experimental investigation of coating degradation during simultaneous acid and erosive particle exposure

    DEFF Research Database (Denmark)

    Møller, Victor Buhl; Dam-Johansen, Kim; Frankær, Sarah Maria

    of a simultaneous exposure. To investigate this, a pilot-scale stirred acid leaching tank, containing erosive particles and acidic solutions, has been designed and constructed. Resin types considered are amine-cured novolac epoxy and vinyl ester. Transient coating degradation is mapped through visual inspection...

  18. EVALUACIÓN EXPERIMENTAL DEL COMPORTAMIENTO DE LA VELOCIDAD DE SEDIMENTACIÓN DE PARTÍCULAS EXPERIMENTAL EVALUATION OF THE BEHAVIOUR OF THE SEDIMENTATION VELOCITY OF PARTICLES

    Directory of Open Access Journals (Sweden)

    Gonzalo Salinas-Salas

    2012-06-01

    Full Text Available El presente artículo de investigación presenta los elementos teóricos, la metodología, resultados y conclusiones de un trabajo desarrollado con el fin de determinar el comportamiento de la velocidad de sedimentación terminal de sistemas de partículas no coloidales de tamaño medio menor a 1.000 nm respecto de sistemas de partículas de tamaño mayor a este. Para esto se analiza el comportamiento del factor de reducción de velocidad terminal de sedimentación. Dada la extrema complejidad de la fenomenología del proceso de sedimentación de sistemas de partículas de diámetros medios menores a 1.000 nm, obliga a que este trabajo tenga un carácter experimental. Los resultados alcanzados mostraron que existe una diferencia entre el comportamiento de la velocidad de sedimentación de sistemas de partículas mayores a 1.000 nm, respecto de los sistemas de partículas cuyo tamaño es menor a este, lo que impacta en el valor que adopta el factor de corrección.This article presents the theoretical aspects, methodology, results and conclusions of a study developed to determine the behavior of the terminal settling velocity of noncolloidal particles systems of average sizes smaller than 1,000 nm in comparison to larger particles system. In order to do this, an analysis of the behavior of the reduction factor of terminal velocity of sedimentation was made. Due to the extreme complexity of the phenomenology of the sedimentation process of average particles systems in diameters smaller than 1,000 nm, an experimental work was required. The results indicate that there is a difference between the behavior of the velocity settling of particle systems greater than 1,000 nm, for systems of particles which size is smaller than this, what impacts the value that takes the correction factor.

  19. Experimental evidence of adiabatic splitting of charged particle beams using stable islands of transverse phase space

    CERN Document Server

    Gilardoni, S S; Martini, M; Métral, E; Steerenberg, R; Müller, A-S

    2006-01-01

    Recently, a novel technique to perform multi-turn extraction from a circular particle accelerator was proposed. It is based on beam splitting and trapping, induced by a slow crossing of a nonlinear resonance, inside stable islands of transverse phase space. Experiments at the CERN Proton Synchrotron started in 2002 and evidence of beam splitting was obtained by summer 2004. In this paper the measurement results achieved with both a low- and a high-intensity, single-bunch proton beam are presented.

  20. Experimental evidence for particle stability of {sup 34}Ne and {sup 37}Na

    Energy Technology Data Exchange (ETDEWEB)

    Lukyanov, S.M.; Penionzhkevich, Y.E.; Astabatyan, R.; Lobastov, S.; Sobolev, Y. [Joint Institute for Nuclear Research, Flerov Lab. of Nuclear Reaction, Dubna (Russian Federation); Guillemaud-Mueller, D.; Faivre, G.; Ibrahim, F.; Mueller, A.C.; Pougheon, F.; Perru, O.; Sorlin, O. [Institut de Physique Nucleaire, 91 - Orsay (France); Matea, I.; Anne, R.; Cauvin, C.; Hue, R.; Georgiev, G.; Lewitowicz, M.; Oliveira Santos, F. de; Verney, D. [Grand Accelerateur National d' Ions Lourds (GANIL), 14 - Caen (France); Dlouhy, Z.; Mrazek, J.; Baiborodin, D. [Nuclear Physics Institute, Rez (Czech Republic); Negoita, F.; Borcea, C.; Buta, A.; Stefan, I. [Institute of Atomic Physics, Bucharest-Magurele (Romania); Grevy, S. [Laboratoire de Physique Corpusculaire, 14 - Caen (France)

    2002-07-01

    The neutron drip line in neon-magnesium region has been explored by the projectile fragmentation of a 59.8 A MeV {sup 48}Ca beam using the new fragment separator LISE-2000 at GANIL. New neutron-rich isotopes, {sup 34}Ne and {sup 37}Na, have been observed together with some evidence for the particle instability of {sup 33}Ne and {sup 36}Na. (authors)

  1. Experimental shock metamorphism of terrestrial basalts: Agglutinate-like particle formation, petrology, and magnetism

    Science.gov (United States)

    Badyukov, Dmitrii D.; Bezaeva, Natalia S.; Rochette, Pierre; Gattacceca, Jérôme; Feinberg, Joshua M.; Kars, Myriam; Egli, Ramon; Raitala, Jouko; Kuzina, Dilyara M.

    2018-01-01

    Hypervelocity impacts occur on bodies throughout our solar system, and play an important role in altering the mineralogy, texture, and magnetic properties in target rocks at nanometer to planetary scales. Here we present the results of hypervelocity impact experiments conducted using a two-stage light-gas gun with 5 mm spherical copper projectiles accelerated toward basalt targets with 6 km s-1 impact velocities. Four different types of magnetite- and titanomagnetite-bearing basalts were used as targets for seven independent experiments. These laboratory impacts resulted in the formation of agglutinate-like particles similar in texture to lunar agglutinates, which are an important fraction of lunar soil. Materials recovered from the impacts were examined using a suite of complementary techniques, including optical and scanning electron microscopy, micro-Raman spectroscopy, and high- and low-temperature magnetometry, to investigate the texture, chemistry, and magnetic properties of newly formed agglutinate-like particles and were compared to unshocked basaltic parent materials. The use of Cu-projectiles, rather than Fe- and Ni-projectiles, avoids magnetic contamination in the final shock products and enables a clearer view of the magnetic properties of impact-generated agglutinates. Agglutinate-like particles show shock features, such as melting and planar deformation features, and demonstrate shock-induced magnetic hardening (two- to seven-fold increases in the coercivity of remanence Bcr compared to the initial target materials) and decreases in low-field magnetic susceptibility and saturation magnetization.

  2. Optimization of the Hewlett-Packard particle-beam liquid chromatography-mass spectrometry interface by statistical experimental design.

    Science.gov (United States)

    Huang, S K; Garza, N R

    1995-06-01

    Optimization of both sensitivity and ionization softness for the Hewlett-Packard particle-beam liquid chromatography-mass spectrometry interface has been achieved by using a statistical experimental design with response surface modeling. Conditions for both optimized sensitivity and ionization softness were found to occur at 55-lb/in.(2) nebulizer flow, 35°C desolvation chamber temperature with approximately 45% organic modifier in the presence of 0.02-F ammonium acetate and a liquid chromatography flow rate of 0.2 mL/min.

  3. Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence

    Directory of Open Access Journals (Sweden)

    Mimoun Maurice

    2011-03-01

    Full Text Available Abstract Background Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD. Methods The study was carried out in 4 steps: i patient room design, ii CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii construction of a prototype room and subsequent experimental studies to characterize its performance iv qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF open-source software Code_Saturne® (http://www.code-saturne.org was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations. Results We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to

  4. Accumulation and transport of microbial-size particles in a pressure protected model burn unit: CFD simulations and experimental evidence.

    Science.gov (United States)

    Beauchêne, Christian; Laudinet, Nicolas; Choukri, Firas; Rousset, Jean-Luc; Benhamadouche, Sofiane; Larbre, Juliette; Chaouat, Marc; Benbunan, Marc; Mimoun, Maurice; Lajonchère, Jean-Patrick; Bergeron, Vance; Derouin, Francis

    2011-03-03

    Controlling airborne contamination is of major importance in burn units because of the high susceptibility of burned patients to infections and the unique environmental conditions that can accentuate the infection risk. In particular the required elevated temperatures in the patient room can create thermal convection flows which can transport airborne contaminates throughout the unit. In order to estimate this risk and optimize the design of an intensive care room intended to host severely burned patients, we have relied on a computational fluid dynamic methodology (CFD). The study was carried out in 4 steps: i) patient room design, ii) CFD simulations of patient room design to model air flows throughout the patient room, adjacent anterooms and the corridor, iii) construction of a prototype room and subsequent experimental studies to characterize its performance iv) qualitative comparison of the tendencies between CFD prediction and experimental results. The Electricité De France (EDF) open-source software Code_Saturne® (http://www.code-saturne.org) was used and CFD simulations were conducted with an hexahedral mesh containing about 300 000 computational cells. The computational domain included the treatment room and two anterooms including equipment, staff and patient. Experiments with inert aerosol particles followed by time-resolved particle counting were conducted in the prototype room for comparison with the CFD observations. We found that thermal convection can create contaminated zones near the ceiling of the room, which can subsequently lead to contaminate transfer in adjacent rooms. Experimental confirmation of these phenomena agreed well with CFD predictions and showed that particles greater than one micron (i.e. bacterial or fungal spore sizes) can be influenced by these thermally induced flows. When the temperature difference between rooms was 7°C, a significant contamination transfer was observed to enter into the positive pressure room when the

  5. Experimental evidence of adiabatic splitting of charged particle beams using stable islands of transverse phase space

    Directory of Open Access Journals (Sweden)

    S. Gilardoni

    2006-10-01

    Full Text Available Recently, a novel technique to perform multiturn extraction from a circular particle accelerator was proposed. It is based on beam splitting and trapping, induced by a slow crossing of a nonlinear resonance, inside stable islands of transverse phase space. Experiments at the CERN Proton Synchrotron started in 2002 and evidence of beam splitting was obtained by summer 2004. In this paper, the measurement results achieved with both a low- and a high-intensity, single-bunch proton beam are presented.

  6. Elementary analysis

    CERN Document Server

    Snell, K S; Langford, W J; Maxwell, E A

    1966-01-01

    Elementary Analysis, Volume 2 introduces several of the ideas of modern mathematics in a casual manner and provides the practical experience in algebraic and analytic operations that lays a sound foundation of basic skills. This book focuses on the nature of number, algebraic and logical structure, groups, rings, fields, vector spaces, matrices, sequences, limits, functions and inverse functions, complex numbers, and probability. The logical structure of analysis given through the treatment of differentiation and integration, with applications to the trigonometric and logarithmic functions, is

  7. Elementary vectors

    CERN Document Server

    Wolstenholme, E Œ

    1978-01-01

    Elementary Vectors, Third Edition serves as an introductory course in vector analysis and is intended to present the theoretical and application aspects of vectors. The book covers topics that rigorously explain and provide definitions, principles, equations, and methods in vector analysis. Applications of vector methods to simple kinematical and dynamical problems; central forces and orbits; and solutions to geometrical problems are discussed as well. This edition of the text also provides an appendix, intended for students, which the author hopes to bridge the gap between theory and appl

  8. Size effects on the scattering matrices of clay particles: An experimental study

    Directory of Open Access Journals (Sweden)

    O. Munoz

    2011-09-01

    Full Text Available We present experimental scattering matrix elements as functions of the scattering angle of two sets of three samples of clays (yellow, green, and white. The measurements were performed in Amsterdam at a wavelength of 633 nm, and at the IAA cosmic dust laboratory in Granada at 647 nm. We study the impact of different sizes on the measured scattering matrix elements.

  9. Size effects on the scattering matrices of clay particles: an experimental study.

    Science.gov (United States)

    Munoz, Olga; Moreno, F.; Dabrowska, D. D.; Volten, H.; Hovenier, J. W.

    2011-09-01

    We present experimental scattering matrix elements as functions of the scattering angle of two sets of three samples of clays (yellow, green and white). The measurements were performed in Amsterdam at 633 nm and at the IAA cosmic laboratory in Granada at 647 nm. We study the impact of different sizes on the measured scattering matrix elements.

  10. Experimental investigation of the radial structure of energetic particle driven modes

    CERN Document Server

    Horvath, L; Lauber, Ph; Por, G; Gude, A; Igochine, V; Geiger, B; Maraschek, M; Guimarais, L; Nikolaeva, V; Pokol, G I

    2016-01-01

    Alfv\\'en eigenmodes (AEs) and energetic particle modes (EPMs) are often excited by energetic particles (EPs) in tokamak plasmas. One of the main open questions concerning EP driven instabilities is the non-linear evolution of the mode structure. The aim of the present paper is to investigate the properties of beta-induced AEs (BAEs) and EP driven geodesic acoustic modes (EGAMs) observed in the ramp-up phase of off-axis NBI heated ASDEX Upgrade (AUG) discharges. This paper focuses on the changes in the mode structure of BAEs/EGAMs during the non-linear chirping phase. Our investigation has shown that in case of the observed down-chirping BAEs the changes in the radial structure are smaller than the uncertainty of our measurement. This behaviour is most probably the consequence of that BAEs are normal modes, thus their radial structure strongly depends on the background plasma parameters rather than on the EP distribution. In the case of rapidly upward chirping EGAMs the analysis consistently shows shrinkage of...

  11. Extra-dimensional confinement of quantum particles

    CERN Document Server

    Hedin, Eric R

    2016-01-01

    A basic theoretical framework is developed in which elementary particles have a component of their wave function extending into higher spatial dimensions. This model postulates an extension of the Schrodinger equation to include a 4th and 5th spatial component. A higher-dimensional simple harmonic oscillator confining potential localizes particles into 3-d space, characterizing the brane tension which confines Standard Model particles to the sub-manifold. Quantum effects allow a non-zero probability for a particle's evanescent existence in the higher dimensions, and suggest an experimental test for the validity of this model via particles being temporarily excited into the first excited state of the extra-dimensional potential well, in which their probability of existing in 3-d space transiently drops to zero. Several consistency checks of the outcomes of this extra-dimensional model are included in this paper. Among the outcomes of this model are: a match with the quantum phenomenon of zitterbewegung; the pr...

  12. Outward particle transport by coherent mode in the H-mode pedestal in the Experimental Advanced Superconducting Tokamak (EAST)

    Science.gov (United States)

    Zhang, T.; Han, X.; Gao, X.; Liu, H. Q.; Shi, T. H.; Liu, J. B.; Liu, Y.; Kong, D. F.; Liu, Z. X.; Qu, H.; Xiang, H. M.; Geng, K. N.; Wang, Y. M.; Wen, F.; Zhang, S. B.; Ling, B. L.; the EAST Team

    2017-06-01

    A coherent mode (CM) in the edge pedestal region has been observed on different fluctuation quantities, including density fluctuation, electron temperature fluctuation and magnetic fluctuation in H mode plasma on the Experimental Advanced Superconducting Tokamak (EAST) tokamak. Measurements at different poloidal positions show that the local poloidal wavenumber is smallest at the outboard midplane and will increase with poloidal angle. This poloidal asymmetry is consistent with the flute-like assumption (i.e. k// ˜ 0) from which the toroidal mode number of the mode has been estimated as between 12 and 17. It was further found that the density fluctuation amplitude of the CM also demonstrated poloidal asymmetry. The appearance of a CM can clearly decrease or even stop the increase in the edge density, while the disappearance of a CM will lead to an increase in the pedestal density and density gradient. Statistical analysis showed there was a trend that as the CM mode amplitude increased, the rate of increase of the edge density decreased and the particle flux (Γdiv) onto the divertor plate increased. The CM sometimes showed burst behavior, and these bursts led bursts on Γdiv with a time of about 230 μs, which is close to the time for particle flow from the outer midplane to the divertor targets along the scrape-off layer magnetic field line. This evidence showed that the CM had an effect on the outward transport of particles.

  13. The decay of 'mesotrons' (1939-1943), experimental particle physics in the age of innocence

    Science.gov (United States)

    Rossi, B.

    1983-01-01

    An account is given of the experimental work carried out by the author and his associates during the years 1939 through 1943, which produced the first unambiguous evidence of the spontaneous decay of 'mesotrons', showed that this decay occurred according to an exponential law, as expected, and measured the mean life with a 3 percent accuracy. A byproduct of this work was a verification of the relativistic equation for the dilation of time intervals. Previously announced in STAR as N81-76151

  14. Experimental particle physics at the University of Pittsburgh. Progress report, November 1, 1991--October 31, 1992

    Energy Technology Data Exchange (ETDEWEB)

    Engels, E. Jr.; Perera, U.; Shepard, P.F.; Thompson, J.A.

    1992-04-01

    During the past year Task A completed the HELIOS single and pair electron analyses and found no anomalous production or multiplicity dependence. The HELIOS electron-muon pair analysis continued in its search for lepton physics beyond the expected charm yields. Data taking began at the CMD2 detector at Novosibirsk. Measurements of the U. V. reflectivity and photomultiplier tests for the first Cerenkov counter to be used in the E865 experiment at BNL were carried out, along with the development of a general ray-tracing code. The design of the Cerenkov counter for E865 along with development of light mirror fabrication techniques were a major part of the Task A program. The principal efforts of Task B, the Fermilab program, have been the completion of the analysis of the 1987--1988 data with resulting publications, completion of the 1990--1991 data run, and the beginning of the analysis of the 1990--1991 data. In addition, the Task B group is taking a leadership role in developing a proposal to Fermilab for the upgrade of the CDF silicon vertex detector in preparation for the 1995 data run. This proposal is to be presented to the laboratory management in time for the fall Fermilab Program Advisory Committee meeting. Task C has recently submitted results of its fractionally charged particle searches, placing new upper limits on the abundance of naturally-occurring fractionally-charged particles in various materials. This group has recently been approved by the Brookhaven management for an exposure of their p-i-n diodes in a high intensity proton beam. This measurement, along with its subsequent analysis, will complete the program.

  15. Digital Photography for Elementary Students

    Science.gov (United States)

    Neckers, Matt

    2009-01-01

    Most elementary students approach photography in an open-minded, experimental way. As a result, their images are often more playful than those taken by adults. Students discover more through their own explorations than they would learn through overly structured lessons. In this article, the author describes how he introduces his elementary…

  16. The effect of the particle shape and structure on the flowability of electrolytic copper powder. II. The experimental verification of the model of the representative powder particle

    Directory of Open Access Journals (Sweden)

    MILUTIN C. OBRADOVIC

    2003-10-01

    Full Text Available An analysis of the effects of the shape, surface structure and size distribution of particles on the flowability of the copper powder was performed. It is shown that the most important property of the particles of a powder, regarding the flowability of the powder, is the surface structure of the particles.

  17. Experimental and Numerical Studies of Particle Acceleration by an Active Microwave Medium

    CERN Document Server

    Schoessow, Paul

    2005-01-01

    There has been considerable theoretical work on the so-called PASER concept, in which a particle beam is accelerated directly by absorbing energy from an active medium, analogous to the amplification of an optical signal in a laser. Use of an active microwave (maser) medium would have the advantage of requiring relaxed beam quality (mm vs. nm characteristic beam dimensions). Recent work using electron paramagnetic resonance (EPR) techniques has demonstrated activity in the microwave regime (i.e. negative imaginary part of the magnetic susceptibility) for a class of organic compounds. A solution of fullerene (C60) in a liquid crystal solvent has been reported in the literature to possess a maser transition in the X-band region. An external DC magnetic field is required to obtain the effect; the frequency of the maser transition is adjustable by varying the magnetic field strength. We will report on the development of numerical and laboratory tools to evaluate the use of this material for accelerator applicatio...

  18. An irradiation chamber for experimental studies on SSNTD response to alpha particles

    Energy Technology Data Exchange (ETDEWEB)

    Marocco, D. [Istituto Superiore di Sanita, Italian National Institute of Health, Viale Regina Elena 299, I-00161 Rome (Italy); Bochicchio, F. [Istituto Superiore di Sanita, Italian National Institute of Health, Viale Regina Elena 299, I-00161 Rome (Italy)]. E-mail: francesco.bochicchio@iss.it

    2005-11-15

    An irradiation apparatus was designed in our laboratory to study the detection efficiency dependence of SSNTDs (CR-39, LR115, Makrofol) on alpha particles of different energy and incident angle. The system was designed to irradiate up to nine detectors in a short time, allowing to obtain reproducible conditions on many detectors and therefore to reduce random variations of the results. The system is composed of a pressure-controlled stainless-steel chamber containing a {sup 241}Am source and a circular rotating table with 10 detector holders, one of which is devoted to an ion-implanted silicon detector for irradiation energy monitoring. The table rotation is controlled electronically via a photodiode-based system, so that the position of the detectors under the source is known with a maximum uncertainty of 0.5mm. The detector holders allow to change the detector (both passive and active) to source inclination angle continuously and with an uncertainty better than 1 deg. The source-to-detector distance is controlled electronically and can be varied from 5 to 30cm with an uncertainty of about 0.1mm. Some simulations, obtained using the transport code TRIM, to project the irradiation chamber and its main characteristics are reported and discussed.

  19. Evaluation of therapeutic potential of nanosilver particles synthesised using aloin in experimental murine mastitis model.

    Science.gov (United States)

    Chaitanya Kumar, Thota Venkata; Muralidhar, Yegireddy; Prasad, Pagadala Eswara; Prasad, Tollamadugu Naga Venkata Krishna Vara; Alpha Raj, Mekapogu

    2013-09-01

    Nanobiotechnology is an emerging biological branch of nanotechnology. Application of nanoparticles with specific size and shape in biology has already shown unforeseen and interesting results. A study was conducted to evaluate the therapeutic potential of phytogenically derived aloin mediated nanosilver particles (AAgNPs), prepared by reduction of silver nitrate with aloin, in Staphylococcus aureus induced murine mastitis. A total of 40 female mice were divided into five groups of eight animals each. Group I served as lactating control, groups II-V were inoculated with 20 μl of 24 h broth culture of S. aureus containing 4.0 × 105 cfu/quarter under ketamine anaesthesia. After 6 h post inoculation, groups III and IV received 20 μl of aloin nanosilver (AAgNPs) through intramammary and intraperitoneal routes, respectively. Group V received antibiotic cefepime at 1 mg/kg body weight through the intra-peritoneal route. After 18 h post-treatment, serum C reactive protein, weights of mammary glands, mammary gland bacterial load, thiobarbituric acid reactive substances content, reduced glutathione content, superoxide dismutase activity and catalase activity and histopathology were determined. The compound showed a minimum inhibitory concentration of 21.8 ng/ml against S. aureus. Significant reduction (98%) in poly-morpho nuclear cell infiltration was observed with AAgNPs than antibiotic (50%).

  20. Resonant pickups for non-destructive single-particle detection in heavy-ion storage rings and first experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Sanjari, Mohammad Shahab

    2013-04-26

    Nuclear astrophysics studies on highly charged radionuclides benefit from accelerator facilities with storage rings, where exotic nuclides produced with small yields can be efficiently investigated. Currently there are two accelerator facilities capable of storing highly charged heavy ions, GSI in Darmstadt and IMP in Lanzhou. Non-destructive detection methods are often used for in-flight measurements based on frequency analysis. The sensitivity of such detection systems are of primary importance specially when number of stored ions is small. Furthermore, since the exotic nuclides of interest are as a rule short-lived, the detectors must be fast. One common form of such detectors are parallel plate SCHOTTKY monitors, on which particles induce a mirror charge at each passage. This method has been successfully used at ESR experimental storage ring of GSI since 1991. In this work we describe a new resonant SCHOTTKY pickup operating as a high sensitive cavity current monitor which was mounted and commissioned in the ESR early 2010. It was successfully used in several storage ring experiments. A very similar pickup was mounted in CSRe at IMP Lanzhou in 2011. First in-ring tests have been performed and new experimental results are pending. The spectral analysis of acquired signals by the new detector has enabled a broad range of new physics experiments. The theory of operation and first experimental results and future perspectives are presented in this thesis.

  1. Particle and impurity transport in the Axial Symmetric Divertor Experiment Upgrade and the Joint European Torus, experimental observations and theoretical understanding

    DEFF Research Database (Denmark)

    Angioni, C.; Carraro, L.; Dannert, T.

    2007-01-01

    Experimental observations on core particle and impurity transport from the Axial Symmetric Divertor Experiment Upgrade [O. Gruber, H.-S. Bosch, S. Gunter , Nucl Fusion 39, 1321 (1999)] and the Joint European Torus [J. Pamela, E. R. Solano, and JET EFDA Contributors, Nucl. Fusion 43, 1540 (2003......)] tokamaks are reviewed and compared. Robust general experimental behaviors observed in both the devices and related parametric dependences are identified. The experimental observations are compared with the most recent theoretical results in the field of core particle transport. (C) 2007 American Institute...

  2. Experimental data on the properties of natural fiber particle reinforced polymer composite material

    Directory of Open Access Journals (Sweden)

    D. Chandramohan

    2017-08-01

    Full Text Available This paper presents an experimental study on the development of polymer bio-composites. The powdered coconut shell, walnut shells and Rice husk are used as reinforcements with bio epoxy resin to form hybrid composite specimens. The fiber compositions in each specimen are 1:1 while the resin and hardener composition 10:1 respectively. The fabricated composites were tested as per ASTM standards to evaluate mechanical properties such as tensile strength, flexural strength, shear strength and impact strength are evaluated in both with moisture and without moisture. The result of test shows that hybrid composite has far better properties than single fibre glass reinforced composite under mechanical loads. However it is found that the incorporation of walnut shell and coconut shell fibre can improve the properties.

  3. Neutron interferometry lessons in experimental quantum mechanics, wave-particle duality, and entanglement

    CERN Document Server

    Rauch, Helmut

    2015-01-01

    The quantum interference of de Broglie matter waves is probably one of the most startling and fundamental aspects of quantum mechanics. It continues to tax our imaginations and leads us to new experimental windows on nature. Quantum interference phenomena are vividly displayed in the wide assembly of neutron interferometry experiments, which have been carried out since the first demonstration of a perfect silicon crystal interferometer in 1974. Since the neutron experiences all four fundamental forces of nature (strong, weak, electromagnetic, and gravitational), interferometry with neutrons provides a fertile testing ground for theory and precision measurements. Many Gedanken experiments of quantum mechanics have become real due to neutron interferometry. Quantum mechanics is a part of physics where experiment and theory are inseparably intertwined. This general theme permeates the second edition of this book. It discusses more than 40 neutron interferometry experiments along with their theoretical motivation...

  4. Magnetic Particle Imaging (MPI): Experimental Quantification of Vascular Stenosis Using Stationary Stenosis Phantoms.

    Science.gov (United States)

    Vaalma, Sarah; Rahmer, Jürgen; Panagiotopoulos, Nikolaos; Duschka, Robert L; Borgert, Jörn; Barkhausen, Jörg; Vogt, Florian M; Haegele, Julian

    2017-01-01

    Magnetic Particle Imaging (MPI) is able to provide high temporal and good spatial resolution, high signal-to-noise ratio and sensitivity. Furthermore, it is a truly quantitative method as its signal strength is proportional to the concentration of its tracer, superparamagnetic iron oxide nanoparticles (SPIOs). Because of that, MPI is proposed to be a promising future method for cardiovascular imaging. Here, an interesting application may be the quantification of vascular pathologies like stenosis by utilizing the proportionality of the SPIO concentration and the MPI signal strength. In this study, the feasibility of MPI based stenosis quantification is evaluated based on this application scenario. Nine different stenosis phantoms with a normal diameter of 10 mm each and different stenoses of 1-9 mm and ten reference phantoms with a straight diameter of 1-10 mm were filled with a 1% Resovist dilution and measured in a preclinical MPI-demonstrator. The MPI signal intensities of the reference phantoms were compared to each other and the change of signal intensity within each stenosis phantom was used to calculate the degree of stenosis. These values were then compared to the known diameters of each phantom. As a second measurement, the 5 mm stenosis phantom was used for a serial dilution measurement down to a Resovist dilution of 1:3200 (0.031%), which is lower than a first pass blood concentration of a Resovist bolus in the peripheral arteries of an average adult human of at least about 1:1000. The correlation of the stenosis values based on MPI signal intensity measurements and based on the known diameters showed a very good agreement, proving the high precision of quantitative MPI in this regard.

  5. 3D range-modulator for scanned particle therapy: development, Monte Carlo simulations and experimental evaluation

    Science.gov (United States)

    Simeonov, Yuri; Weber, Uli; Penchev, Petar; Printz Ringbæk, Toke; Schuy, Christoph; Brons, Stephan; Engenhart-Cabillic, Rita; Bliedtner, Jens; Zink, Klemens

    2017-09-01

    The purpose of this work was to design and manufacture a 3D range-modulator for scanned particle therapy. The modulator is intended to create a highly conformal dose distribution with only one fixed energy, simultaneously reducing considerably the treatment time. As a proof of concept, a 3D range-modulator was developed for a spherical target volume with a diameter of 5 cm, placed at a depth of 25 cm in a water phantom. It consists of a large number of thin pins with a well-defined shape and different lengths to modulate the necessary shift of the Bragg peak. The 3D range-modulator was manufactured with a rapid prototyping technique. The FLUKA Monte Carlo package was used to simulate the modulating effect of the 3D range-modulator and the resulting dose distribution. For that purpose, a special user routine was implemented to handle its complex geometrical contour. Additionally, FLUKA was extended with the capability of intensity modulated scanning. To validate the simulation results, dose measurements were carried out at the Heidelberg Ion Beam Therapy Center with a 400.41 MeV/u 12C beam. The high resolution dosimetric measurements show a good agreement between simulated and measured dose distributions. Irradiation of the monoenergetic raster plan took 3 s, which is approximately 20 times shorter than a comparable plan with 16 different energies. The combination of only one energy and a 3D range-modulator leads to a tremendous decrease in irradiation time. ‘Interplay effects’, typical for moving targets and pencil beam scanning, can be immensely reduced or disappear completely, making the delivery of a homogeneous dose to moving targets more reliable. Combining high dose conformity, very good homogeneity and extremely short irradiation times, the 3D range-modulator is considered to become a clinically applicable method for very fast treatment of lung tumours.

  6. Optimization of Monte Carlo particle transport parameters and validation of a novel high throughput experimental setup to measure the biological effects of particle beams.

    Science.gov (United States)

    Patel, Darshana; Bronk, Lawrence; Guan, Fada; Peeler, Christopher R; Brons, Stephan; Dokic, Ivana; Abdollahi, Amir; Rittmüller, Claudia; Jäkel, Oliver; Grosshans, David; Mohan, Radhe; Titt, Uwe

    2017-11-01

    Accurate modeling of the relative biological effectiveness (RBE) of particle beams requires increased systematic in vitro studies with human cell lines with care towards minimizing uncertainties in biologic assays as well as physical parameters. In this study, we describe a novel high-throughput experimental setup and an optimized parameterization of the Monte Carlo (MC) simulation technique that is universally applicable for accurate determination of RBE of clinical ion beams. Clonogenic cell-survival measurements on a human lung cancer cell line (H460) are presented using proton irradiation. Experiments were performed at the Heidelberg Ion Therapy Center (HIT) with support from the Deutsches Krebsforschungszentrum (DKFZ) in Heidelberg, Germany using a mono-energetic horizontal proton beam. A custom-made variable range selector was designed for the horizontal beam line using the Geant4 MC toolkit. This unique setup enabled a high-throughput clonogenic assay investigation of multiple, well defined dose and linear energy transfer (LETs) per irradiation for human lung cancer cells (H460) cultured in a 96-well plate. Sensitivity studies based on application of different physics lists in conjunction with different electromagnetic constructors and production threshold values to the MC simulations were undertaken for accurate assessment of the calculated dose and the dose-averaged LET (LETd ). These studies were extended to helium and carbon ion beams. Sensitivity analysis of the MC parameterization revealed substantial dependence of the dose and LETd values on both the choice of physics list and the production threshold values. While the dose and LETd calculations using FTFP_BERT_LIV, FTFP_BERT_EMZ, FTFP_BERT_PEN and QGSP_BIC_EMY physics lists agree well with each other for all three ions, they show large differences when compared to the FTFP_BERT physics list with the default electromagnetic constructor. For carbon ions, the dose corresponding to the largest LETd

  7. Experimental investigation into the impact of a liquid droplet onto a granular bed using three-dimensional, time-resolved, particle tracking.

    Science.gov (United States)

    Long, Edward J; Hargrave, Graham K; Cooper, James R; Kitchener, Ben G B; Parsons, Anthony J; Hewett, Caspar J M; Wainwright, John

    2014-03-01

    An experimental investigation into the interaction that occurs between an impacting water droplet and a granular bed of loose graded sand has been carried out. High-speed imaging, three-dimensional time-resolved particle tracking, and photogrammetric surface profiling have been used to examine individual impact events. The focus of the study is the quantification and trajectory analysis of the particles ejected from the sand bed, along with measurement of the change in bed morphology. The results from the experiments have detailed two distinct mechanisms of particle ejection: the ejection of water-encapsulated particles from the edge of the wetted region and the ejection of dry sand from the periphery of the impact crater. That the process occurs by these two distinct mechanisms has hitherto been unobserved. Presented in the paper are distributions of the particle ejection velocities, angles, and transport distances for both mechanisms. The ejected water-encapsulated particles, which are few in number, are characterized by low ejection angles and high ejection velocities, leading to large transport distances; the ejected dry particles, which are much greater in number, are characterized by high ejection angles and low velocities, leading to lower transport distances. From the particle ejection data, the momentum of the individual ballistic sand particles has been calculated; it was found that only 2% of the water-droplet momentum at impact is transferred to the ballistic sand particles. In addition to the particle tracking, surface profiling of the granular bed postimpact has provided detailed information on its morphology; these data have demonstrated the consistent nature of the craters produced by the impact and suggest that particle agglomerations released from their edges make up about twice the number of particles involved in ballistic ejection. It is estimated that, overall, about 4% of the water-droplet momentum is taken up in particle movement.

  8. Using Silver Nano-Particle Ink in Electrode Fabrication of High Frequency Copolymer Ultrasonic Transducers: Modeling and Experimental Investigation

    Directory of Open Access Journals (Sweden)

    Adit Decharat

    2015-04-01

    Full Text Available High frequency polymer-based ultrasonic transducers are produced with electrodes thicknesses typical for printed electrodes obtained from silver (Ag nano-particle inks. An analytical three-port network is used to study the acoustic effects imposed by a thick electrode in a typical layered transducer configuration. Results from the network model are compared to experimental findings for the implemented transducer configuration, to obtain a better understanding of acoustical effects caused by the additional printed mass loading. The proposed investigation might be supportive of identification of suitable electrode-depositing methods. It is also believed to be useful as a feasibility study for printed Ag-based electrodes in high frequency transducers, which may reduce both the cost and production complexity of these devices.

  9. Experimental detection of upward-going cosmic particles and consequences for correction of density radiography of volcanoes

    Science.gov (United States)

    Jourde, Kevin; Gibert, Dominique; Marteau, Jacques; de Bremond d'Ars, Jean; Gardien, Serge; Girerd, Claude; Ianigro, Jean-Christophe; Carbone, Daniele

    2014-05-01

    Muon tomography measures the flux of cosmic muons crossing geological bodies to determine their density. Three acquisitions with different sights of view were made at la soufrière de Guadeloupe. All of them show important density fluctuations and reveal the volcano phreatic system. The telescopes used to perform these measurements are exposed to noise fluxes with high intensities relative to the tiny flux of interest. We give experimental evidences ofa so far never described source of noise caused by a flux of upward-going particles. Data acquired on La soufrière of Guadeloupe and Mount Etna reveal that upward-going particles are detected only when the rear side of the telescope is exposed to a wide volume of atmosphere located below the altitude of the telescope and with a rock obstruction less than several tens of meters. Biases produced on density muon radiographies by upward-going fluxes are quantified and correction procedures are applied to radiographies of la soufrière.

  10. Probabilistic evidential assessment of gunshot residue particle evidence (Part II): Bayesian parameter estimation for experimental count data.

    Science.gov (United States)

    Biedermann, A; Bozza, S; Taroni, F

    2011-03-20

    Part I of this series of articles focused on the construction of graphical probabilistic inference procedures, at various levels of detail, for assessing the evidential value of gunshot residue (GSR) particle evidence. The proposed models--in the form of Bayesian networks--address the issues of background presence of GSR particles, analytical performance (i.e., the efficiency of evidence searching and analysis procedures) and contamination. The use and practical implementation of Bayesian networks for case pre-assessment is also discussed. This paper, Part II, concentrates on Bayesian parameter estimation. This topic complements Part I in that it offers means for producing estimates usable for the numerical specification of the proposed probabilistic graphical models. Bayesian estimation procedures are given a primary focus of attention because they allow the scientist to combine (his/her) prior knowledge about the problem of interest with newly acquired experimental data. The present paper also considers further topics such as the sensitivity of the likelihood ratio due to uncertainty in parameters and the study of likelihood ratio values obtained for members of particular populations (e.g., individuals with or without exposure to GSR). Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  11. Particles and nuclei an introduction to the physical concepts

    CERN Document Server

    Povh, Bogdan; Scholz, Christoph; Zetsche, Frank; Rodejohann, Werner

    2015-01-01

    This well-known introductory textbook gives a uniform presentation of nuclear and particle physics from an experimental point of view.   The first part, Analysis, is devoted to disentangling the substructure of matter. This part shows that experiments designed to uncover the substructures of nuclei and nucleons have a similar conceptual basis, and lead to the present picture of all matter being constructed from a small number of elementary building blocks and a small number of fundamental interactions.   The second part, Synthesis, shows how the elementary particles may be combined to build hadrons and nuclei. The fundamental interactions, which are responsible for the forces in all systems, become less and less evident in increasingly complex systems. Such systems are in fact dominated by many-body phenomena. A section on neutrino oscillations and one on nuclear matter at high temperatures bridge the field of "nuclear and particle physics" and "modem astrophysics and cosmology.   The seventh revised and e...

  12. Beyond the God particle

    CERN Document Server

    Lederman, Leon M

    2013-01-01

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

  13. Reflections on experimental science Martin Perl

    CERN Document Server

    Perl, Martin Lewis

    1996-01-01

    This is a collection of important lecture and original articles and commentaries by Martin Perl, discoverer of the tau lepton and the third generation of elementary particles, and this year's Nobel Prize winner. This book contains a fascinating and realistic picture of experimental science based on the high energy physics research work carried out by him. Using reprints of his articles with his commentaries, the author presents the various aspects of experimental research in science: the pleasures and risks of experimental work; the pain and frustration with experiments that are useless or fai

  14. Effect of particle size, polydispersity and polymer degradation on progesterone release from PLGA microparticles: Experimental and mathematical modeling.

    Science.gov (United States)

    Busatto, Carlos; Pesoa, Juan; Helbling, Ignacio; Luna, Julio; Estenoz, Diana

    2018-01-30

    Poly(lactic-co-glycolic acid) (PLGA) microparticles containing progesterone were prepared by the solvent extraction/evaporation and microfluidic techniques. Microparticles were characterized by their size distribution, encapsulation efficiency, morphology and thermal properties. The effect of particle size, polydispersity and polymer degradation on the in vitro release of the hormone was studied. A triphasic release profile was observed for larger microparticles, while smaller microspheres showed a biphasic release profile. This behavior is related to the fact that complete drug release was achieved in a few days for smaller microparticles, during which polymer degradation effects are still negligible. A mathematical model was developed that predicts the progesterone release profiles from different-sized PLGA microspheres. The model takes into account both the dissolution and diffusion of the drug in the polymeric matrix as well as the autocatalytic effect of polymer degradation. The model was adjusted and validated with novel experimental data. Simulation results are in very good agreement with experimental results. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources. Experimental results

    Energy Technology Data Exchange (ETDEWEB)

    Panitzsch, Lauri

    2013-02-08

    The experimental determination of the spatial distribution of charged particles along the ion-optical axis in electron cyclotron resonance ion sources (ECRIS) defines the focus of this thesis. The spatial distributions of different ion species were obtained in the object plane of the bending magnet ({approx}45 cm downstream from the plasma electrode) and in the plane of the plasma electrode itself, both in high spatial resolution. The results show that each of the different ion species forms a bloated, triangular structure in the aperture of the plasma electrode. The geometry and the orientation of these structures are defined by the superposition of the radial and axial magnetic fields. The radial extent of each structure is defined by the charge of the ion. Higher charge states occupy smaller, more concentrated structures. The total current density increases towards the center of the plasma electrode. The circular and star-like structures that can be observed in the beam profiles of strongly focused, extracted ion beams are each dominated by ions of a single charge state. In addition, the spatially resolved current density distribution of charged particles in the plasma chamber that impinge on the plasma electrode was determined, differentiating between ions and electrons. The experimental results of this work show that the electrons of the plasma are strongly connected to the magnetic field lines in the source and thus spatially well confined in a triangular-like structure. The intensity of the electrons increases towards the center of the plasma electrode and the plasma chamber, as well. These electrons are surrounded by a spatially far less confined and less intense ion population. All the findings mentioned above were already predicted in parts by simulations of different groups. However, the results presented within this thesis represent the first (and by now only) direct experimental verification of those predictions and are qualitatively transferable to

  16. Experimental and theoretical studies of the streaming flow due to the adsorption of particles at a liquid surface

    Science.gov (United States)

    Singh, P.; Musunuri, N.; Benouaguef, I.; Fischer, I.

    2017-11-01

    The particle image velocimetry (PIV) technique is used to study the streaming flow that is induced when particles are adsorbed at a liquid surface. The flow develops within a fraction of second after the adsorption of the particle. The fluid directly below the particle rises upward, and near the surface, it moves away from the particle. The flow causes powders sprinkled on a liquid surface to disperse on the surface. The flow strength, and the volume over which it extends, decreases with decreasing particle size. The streaming flow induced by the adsorption of two or more particles is a combination of the flows which they induce individually. Work supported by NSF.

  17. Elementary Analysis of a Cometary Surface - the Alpha Particle X-Ray Spectrometer APXS on the Rosetta Mission to Comet 67P/CHURYUMOV-GERASIMENKO

    Science.gov (United States)

    Schmanke, Dirk; Economou, Thanasis; Brueckner, Johannes; Gellert, Ralf; Rodionov, Daniel; Klingelhoefer, Goestar; Girones Lopez, Jordi; Uston, Lionel D.

    After a 10 years cruise the Rosetta probe will reach its final target in the middle of this year, the comet 67P/Churyumov-Gerasimenko. The main objectives of the mission are to gain more knowledge of the composition, the origin and formation of comets and the solar system. After extensive remote examination of the comet the lander Philae will be separated to land on the comet surface. It will start immediately examining the landing site with its scientific payload. A part of this payload is the APXS (Alpha Particle X-Ray Spectrometer), it will measure in situ the chemical composition of the comet's surface and its changes during the journey of the comet towards the sun. APXS is a combination of two spectrometers in one single instrument, being low in mass and power consumption. It will irradiate the cometary surface with Curium 244 sources, which are emitting alpha-particle and X-rays. In the alpha-mode the instrument uses alpha backscattering spectroscopy to detect lower Z elements like C, N and O and groups of elements with higher Z. In the X-ray mode alpha particle/X-ray induced X-ray spectroscopy (XRF) will allow the detection of most of the higher Z elements from Na up to Ni and above. Both modes will be always run in parallel allowing to determine lower and higher Z elements simultaneously. During the long duration travel to the comet checkouts and software updates of the Rosetta probe and its payload were performed at regular intervals. In recent 3 years the solar powered Rosetta probe had to pass a hibernation phase because of a long passage far away from the sun. After the successful wakeup in January 2014 an extensive test phase of all instruments and subsystems has to be performed, including the APXS. After the landing on the comet an intense long measurement phase of all instruments is planned, the First Science Sequence (FSS). It will be followed by a long term science phase (LTS), determined by periodical changes between measurements and forced breaks

  18. Fascinating physics. An illustrated expedition from the universe until the world of the elementary particles; Faszinierende Physik. Ein bebildeter Streifzug vom Universum bis in die Welt der Elementarteilchen

    Energy Technology Data Exchange (ETDEWEB)

    Bahr, Benjamin [Albert-Einstein-Institut (Max-Planck Institut fuer Gravitationsphysik), Golm (Germany); Riebe, Kristin [Potsdam Univ. (Germany). Leibniz-Institut fuer Astrophysik; Resag, Joerg

    2013-07-01

    ''Fascinating physics'' is a picturesque expedition through 140 themes of classical and modern physics. On each one double-page to the reader is thereby offered a compact access in each one theme: From the aurora until the black hole, from the particle accelerator until the GPS system, from the curved space-time until the supersymmetry, from the oscillating dipole until Foucault's pendulum - a large variety of themes is taken up and carefully explained. Thereby the special strength of the book lies in the clear language and the explanations get along mostly without formulas - accompanied by breathtaking pictures, which lead the beauty of our world in front of the eyes.

  19. Elementary particle physics. Progress report covering the five year period November 1, 1974 to October 31, 1979. [Summaries of research activities at Florida State Univ

    Energy Technology Data Exchange (ETDEWEB)

    1979-01-01

    Experimental and theoretical research in high energy physics is summarized. Preparations and proposals for future experiments include high mass states decaying into phi..pi../sup + -/, phi..pi../sup + -/..gamma.. and phiphi produced centrally in 300 GeV/c ..pi../sup -/p interactions, search for baryonium and for hyperonium, exotic states and charm decays, and dilepton production by neutrinos. A list of publications is included. (JFP)

  20. The stable orientations of the net magnetic moment within single-domain particles: Experimental evidence for a range of stable states and implications for rock magnetism and palaeomagnetism

    Science.gov (United States)

    Potter, David K.; Stephenson, Alan

    2006-03-01

    An idealised stable uniaxial single-domain (SD) particle permits only two possible stable positions in which the magnetic moment can lie, either closely parallel or anti-parallel to the particle long (easy) axis. In real acicular SD particles, which have generally been regarded as uniaxial, this implicit two state feature has never been challenged, whilst there has been considerable debate concerning the mechanism of moment reversal between the two states. We present experimental results suggesting that acicular SD particles may actually have a range of several quantifiable stable (or metastable) orientations of the net magnetic moment. In order to help explain our experimental observations we present a new simple model of acicular SD particles, which gives quantitative predictions verified by further experiments. The model also appears to be relevant to other SD particle morphologies and crystal structures (such as hematite). A possible physical basis for our model in acicular particles may lie in non-uniform SD structures (such as the flower or vortex states). Small variations in the non-uniform SD structures available to a particle might allow a range of stable positions of the net moment. The results have several implications for rock magnetism and palaeomagnetism. Firstly, the new model can quantitatively account for several previously unexplained diverse phenomena exhibited by real acicular SD particles. These include the acquisition of gyroremanences and field-impressed anisotropy in dilute dispersions of such particles, as well as observations of transverse components of remanence in individual acicular SD particles. All these phenomena are theoretically impossible in idealised uniaxial SD particles. Interestingly, it appears that these phenomena could now be used to quantify the deviation of real acicular SD particles from ideal uniaxial behaviour and also, therefore, the deviation from a uniform SD structure. In hematite, observations of large field

  1. KMI International Symposium 2013 on "Quest for the Origin of Particles and the Universe"

    Science.gov (United States)

    The mission of the Kobayashi-Maskawa Institute for the Origin of Particles and the Universe (KMI) is to explore new frontiers of modern physics which would solve the fundamental problems in the physics of elementary particles and the universe. KMI integrates the wisdom from various fields, such as theoretical and experimental particle physics, theoretical and observational astrophysics, mathematical physics. About four years from the foundation in April 2010, the KMI International Symposium 2013 on "Quest for the Origin of Particles and the Universe" (KMI 2013) is organized to publish and spread the academic fruits in KMI and simultaneously to discuss the future plan for KMI.

  2. Experimental Approach to Visualize Flow in a Stacked Hollow Fiber Bundle of an Artificial Lung With Particle Image Velocimetry.

    Science.gov (United States)

    Kaesler, Andreas; Schlanstein, Peter C; Hesselmann, Felix; Büsen, Martin; Klaas, Michael; Roggenkamp, Dorothee; Schmitz-Rode, Thomas; Steinseifer, Ulrich; Arens, Jutta

    2017-06-01

    Flow distribution is key in artificial lungs, as it directly influences gas exchange performance as well as clot forming and blood damaging potential. The current state of computational fluid dynamics (CFD) in artificial lungs can only give insight on a macroscopic level due to model simplification applied to the fiber bundle. Based on our recent work on wound fiber bundles, we applied particle image velocimetry (PIV) to the model of an artificial lung prototype intended for neonatal use to visualize flow distribution in a stacked fiber bundle configuration to (i) evaluate the feasibility of PIV for artificial lungs, (ii) validate CFD in the fiber bundle of artificial lungs, and (iii) give a suggestion how to incorporate microscopic aspects into mainly macroscopic CFD studies. To this end, we built a fully transparent model of an artificial lung prototype. To increase spatial resolution, we scaled up the model by a factor of 5.8 compared with the original size. Similitude theory was applied to ensure comparability of the flow distribution between the device of original size and the scaled-up model. We focused our flow investigation on an area (20 × 70 × 43 mm) in a corner of the model with a Stereo-PIV setup. PIV data was compared to CFD data of the original sized artificial lung. From experimental PIV data, we were able to show local flow acceleration and declaration in the fiber bundle and meandering flow around individual fibers, which is not possible using state-of-the-art macroscopic CFD simulations. Our findings are applicable to clinically used artificial lungs with a similar stacked fiber arrangement (e.g., Novalung iLa and Maquet QUADROX-I). With respect to some limitations, we found PIV to be a feasible experimental flow visualization technique to investigate blood-sided flow in the stacked fiber arrangement of artificial lungs. © 2016 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

  3. Experimental investigations on the fluid-mechanics of an electrospun heart valve by means of particle image velocimetry.

    Science.gov (United States)

    Del Gaudio, Costantino; Gasbarroni, Pier Luca; Romano, Giovanni Paolo

    2016-12-01

    End-stage failing heart valves are currently replaced by mechanical or biological prostheses. Both types positively contribute to restore the physiological function of native valves, but a number of drawbacks limits the expected performances. In order to improve the outcome, tissue engineering can offer an alternative approach to design and fabricate innovative heart valves capable to support the requested function and to promote the formation of a novel, viable and correctly operating physiological structure. This potential result is particularly critical if referred to the aortic valve, being the one mainly exposed to structural and functional degeneration. In this regard, the here proposed study presents the fabrication and in vitro characterization of a bioresorbable electrospun heart valve prosthesis using the particle image velocimetry technique either in physiological and pathological fluid dynamic conditions. The scaffold was designed to reproduce the aortic valve geometry, also mimicking the fibrous structure of the natural extracellular matrix. To evaluate its performances for possible implantation, the flow fields downstream the valve were accurately investigated and compared. The experimental results showed a correct functionality of the device, supported by the formation of vortex structures at the edge of the three cusps, with Reynolds stress values below the threshold for the risk of hemolysis (which can be comprised in the range 400-4000N/m(2) depending on the exposure period), and a good structural resistance to the mechanical loads generated by the driving pressure difference. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. The Melting of Spherical Ice Particles Falling at Terminal Velocity in Air: AN Experimental and Theoretical Study.

    Science.gov (United States)

    Rasmussen, Roy Martin

    This study utilized the UCLA cloud physics wind tunnel and the IBM 3033 computer. The wind tunnel experiments were conducted using two separate procedures, depending on the size of the spherical particle. Particles less than 1 mm diameter, were melted in free fall while experiencing a time varying environmental temperature, similar to the variation of temperature it would encounter while freely falling in the atmosphere. Particles larger than 1 mm diameter have a tendency to wander towards the tunnel walls, requiring restraint by a thin nylon fiber frozen halfway through the particle. Using this fiber, the particle was suspended from above. Although attached to a thread, the particle's terminal velocity was constantly maintained during melting by keeping the fiber slack. Particles less than 1 mm diameter usually undergo "sailing" motions upon melting due to the melting of surface protuberances. Once the protuberances are melted, the particle falls with no horizontal drift. The melting ice core was observed to remain tangent with the downstream end of the particle, resulting in an eccentric melting location. The meltwater itself was also observed to circulate due to the external shear of the air on the meltwater surface. For these small particles, no meltwater was shed. Particles larger than 9 mm diameter were found to shed meltwater, with the fraction shed increasing with particle size. Particles between 9 mm and 5 mm diameter did not shed their meltwater, and did not develop an internal circulation. Particles between 1 mm and 5 mm, however, did develop a significant internal circulation, resulting in a conically shaped ice core. For each of the above size ranges, melting theories are developed which are able to quantitatively describe the melting rates of these particles.

  5. Theoretical and Experimental Study of Chemical Transformations of a Methane-Hydrogen-Coal Particles Mixture in a Rapid-Compression Machine

    Science.gov (United States)

    Fedorov, A. V.; Tropin, D. A.; Penyazkov, O. G.; Leshchevich, V. V.; Shimchenko, S. Yu.

    2017-07-01

    Results of an experimental and numerical study of the ignition of a stoichiometric methane-air mixture in the presence of coal particles of diameters 20-52 μm in the range of temperatures 850-1150 K and pressures 1.5-2.0 MPa are presented. It has been found that the particles begin to burn at a temperature of the oxidizing medium above 850 K. At a temperature above 1000 K, burning particles reduce the time and limiting temperature of ignition of the methane-air mixture. A comparison has been made of the calculated data on ignition-delay times of coal in an air-coal mixture and on ignition-delay times of methane and coal in a methane-air-coal mixture with the experimental data. A satisfactory agreement is shown between the data on ignition-delay times of coal and ignition-delay times of methane in all the mixtures in question.

  6. Big Bang Day: 5 Particles - 3. The Anti-particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 3. The Anti-particle. It appears to be the stuff of science fiction. Associated with every elementary particle is an antiparticle which has the same mass and opposite charge. Should the two meet and combine, the result is annihilation - and a flash of light. Thanks to mysterious processes that occurred after the Big Bang there are a vastly greater number of particles than anti-particles. So how could their elusive existence be proved? At CERN particle physicists are crashing together subatomic particles at incredibly high speeds to create antimatter, which they hope will finally reveal what happened at the precise moment of the Big Bang to create the repertoire of elementary particles and antiparticles in existence today.

  7. Can providing a morning healthy snack help to reduce hunger during school time? Experimental evidence from an elementary school in Connecticut.

    Science.gov (United States)

    Castellari, Elena; Berning, Joshua P

    2016-11-01

    While children may be naturally inclined to regulate their hunger, they are also guided by adults and influenced by environmental constraints regarding when and how much to eat. As such, the timing and availability of meals could alter a child's natural eating habits. This could impact the nutritional quality of what they eat as well. We conducted a field experiment with three fourth grade classes at a public elementary school in Eastern Connecticut to analyze if providing a nutritious snack one hour prior to lunch effects a child's level of hunger and consequently their lunch-time consumption. We found students shift their caloric and nutrient intake from lunch to snack time. In addition, we found a significant reduction in student hunger. Our results highlight the importance in considering the timing and quality of meals provided during school time. In our sample, current snack and lunch schedule may not be optimal and changing it can have an impact on the wellbeing of students. Providing healthful options for snack could be an effective way to improve student diets while preserving their ability to make their own choices. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Experimental investigation of the effect of inlet particle properties on the capture efficiency in an exhaust particulate filter

    Energy Technology Data Exchange (ETDEWEB)

    Viswanathan, Sandeep; Rothamer, David; Zelenyuk, Alla; Stewart, Mark; Bell, David

    2017-11-01

    The impact of inlet particle properties on the filtration performance of clean and particulate matter (PM) laden cordierite filter samples was evaluated using PM generated by a spark-ignition direct-injection (SIDI) engine fuelled with tier II EEE certification gasoline. Prior to the filtration experiments, a scanning mobility particle spectrometer (SMPS) was used to measure the electrical-mobility based particle size distribution (PSD) in the SIDI exhaust from distinct engine operating conditions. An advanced aerosol characterization system that comprised of a centrifugal particle mass analyser (CPMA), a differential mobility analyser (DMA), and a single particle mass spectrometer (SPLAT II) was used to obtain additional information on the SIDI particulate, including particle composition, mass, and dynamic shape factors (DSFs) in the transition () and free-molecular () flow regimes. During the filtration experiments, real-time measurements of PSDs upstream and downstream of the filter sample were used to estimate the filtration performance and the total trapped mass within the filter using an integrated particle size distribution method. The filter loading process was paused multiple times to evaluate the filtration performance in the partially loaded state. The change in vacuum aerodynamic diameter () distribution of mass-selected particles was examined for flow through the filter to identify whether preferential capture of particles of certain shapes occurred in the filter. The filter was also probed using different inlet PSDs to understand their impact on particle capture within the filter sample. Results from the filtration experiment suggest that pausing the filter loading process and subsequently performing the filter probing experiments did not impact the overall evolution of filtration performance. Within the present distribution of particle sizes, filter efficiency was independent of particle shape potentially due to the diffusion-dominant filtration

  9. Conferenza internazionale di Siena sulle particelle elementari

    CERN Multimedia

    1964-01-01

    Last year the editor of CERN Courier was privileged to be able to attend the Sienna international conference on elementary particles, held in the historic Italian city at the beginning of October. The following article is a personal recollection of the conference activities, both formal and informal, and of the physics that was discussed there.

  10. New approach for the determination of aerosol refractive indices - Part II: Experimental set-up and application to amorphous silica particles

    Science.gov (United States)

    Hubert, P.; Herbin, H.; Visez, N.; Pujol, O.; Petitprez, D.

    2017-10-01

    This article is the Part II of a work aimed at proposing a new method for determining the optical constants of aerosols. The Part I detailed the theoretical and numerical basis of an algorithm devoted to retrieve the imaginary and the real part of complex refractive indices from extinction spectra of aerosols. This algorithm associates the Mie theory, the single subtractive Kramers-Kronig relation, and an optimal estimation method in an iterative process. This Part II presents the experimental set-up developed to record simultaneously high spectral resolution extinction spectra and size distributions of airborne silica particles. Extinction spectra are measured with a high spectral resolution on a broad spectral range, including both infrared (650 - 2 , 500cm-1) and UV-visible (9 , 000 - 32 , 500cm-1) spectral regions. Experimental data were used to retrieve the complex refractive indices of aerosol particles. By associating the numerical procedure presented in the first paper and this experimental set-up, complex refractive indices of silica spherical aerosol particles have been determined under controlled experimental conditions. Additional comparison between experimental and simulated extinction spectra from retrieved complex refractive indices shows that this new methodology provides optical properties representative of the material.

  11. Experimental evidence of the kinetic performance achievable with columns packed with new 1.9μm fully porous particles of narrow particle size distribution.

    Science.gov (United States)

    Ismail, Omar H; Catani, Martina; Pasti, Luisa; Cavazzini, Alberto; Ciogli, Alessia; Villani, Claudio; Kotoni, Dorina; Gasparrini, Francesco; Bell, David S

    2016-07-08

    Fully porous particles of narrow particle size distribution (nPSD) are now commercially available. In this paper, the kinetic performance of columns packed with these particles (1.9μm, 80Å pore size) has been investigated under typical reversed phase conditions by using a mixture of benzene derivatives as probes. The columns exhibited remarkably high efficiency (in the order of 300,000 theoretical plates per meter) and the possibility to be used at relatively high flow rates without loss of performance. These results contrast with previous studies on the same columns. Indeed we have found column efficiency comparable to that reported in previous work but, on the other hand, we could not observe the same dramatic loss of performance when columns were operated at high flow rates. The results presented in this paper, based on a set of six columns with different geometries (2.1 and 3.0 internal diameter×50, 75 and 100mm length), are not consistent with the previously proposed hypothesis that the unusually low intraparticle diffusion, which would characterize these particles, is the origin of the high efficiency of the columns. In a companion paper [1], a detailed investigation of the different terms leading to band broadening will be performed to point out the major contribution to plate height on nPSD columns. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Higgs-Like Particle due to Revised Quantum Electrodynamics

    Directory of Open Access Journals (Sweden)

    Lehnert B.

    2013-07-01

    Full Text Available A Higgs-like particle having zero net electric charge, zero spin, and a nonzero rest mass can be deduced from an earlier elaborated revised quantum electrodynamical theory which is based on linear symmetry breaking through a nonzero electric field divergence in the vacuum state. This special particle is obtained from a composite longitudinal solution based on a zero magnetic field strength and on a nonzero divergence but a vanishing curl of the electric field strength. The present theory further differs from that of the nonlinear spontaneously broken symmetry by Higgs, in which elementary particles obtain their masses through an interaction with the Higgs field. An experimental proof of the basic features of a Higgs-like particle thus supports the present theory, but does not for certain confirm the process which would generate massive particles through a Higgs field

  13. Micromorphological Aspects of Forensic Geopedology II: Ultramicroscopic vs Microscopic Characterization of Phosphatic Impregnations on Soil Particles in Experimental Burials

    Science.gov (United States)

    Ern, S. I. E.; Trombino, L.; Cattaneo, C.

    2012-04-01

    Grows up the importance of the role played by soil scientists in the modern forensic sciences, in particular when buried human remains strongly decomposed or skeletonized are found in different environment situations. Among the different techniques normally used in geopedology, it is usefull to apply in such forensic cases, soil micromorphology (including optical microscopy and ultramicroscopy) that has been underused up today, for various kind of reasons. An interdisciplinary Italian-team, formed by earth scientists and legal medicine, is working on several sets of experimental burial of pigs and piglets in different soil types and for different times of burial, in order to get new evidences on environmental behaviour related to the burial, focalising on geopedological and micropedological aspects. The present work is focused on: - ultramicroscopic (SEM-EDS) characterization of the phosphatic impregnation (by body fluids) on soils sampled under the dead bodies of five couples of pigs, buried respectively for one month, six month, one year, two years and two years and half in two different areas; - microscopic (petrographic microscope) and ultramicroscopic (SEM-EDS) cross characterization of the phosphatic impregnation (by body fluids) on soils sampled under the dead bodies of several piglets, buried for twenty months. The first results show trends of persistency of such phosphatic features, mainly related to the grain size of the impregnated soil particles and weather conditions (or seasons) of exhumation, while apparently time since burial is only marginally effective for the investigated burial period. Further experiments are in progress in order to clarify the pathways of phosphorus precipitation and leaching for longer times of burial and different seasons of exhumation, both from the microscopic and the pedological/chemical point of view.

  14. Response of spontaneously hypertensive rats to inhalation of fine and ultrafine particles from traffic: experimental controlled study

    Directory of Open Access Journals (Sweden)

    Dormans Jan AMA

    2006-05-01

    Full Text Available Abstract Background Many epidemiological studies have shown that mass concentrations of ambient particulate matter (PM are associated with adverse health effects in the human population. Since PM is still a very crude measure, this experimental study has explored the role of two distinct size fractions: ultrafine (3 to 3613 μg/m3 for fCAP and from 269μg/m3 to 556 μg/m3 for u+fCAP. Results Ammonium, nitrate, and sulphate ions accounted for 56 ± 16% of the total fCAP mass concentrations, but only 17 ± 6% of the u+fCAP mass concentrations. Unambiguous particle uptake in alveolar macrophages was only seen after u+fCAP exposures. Neither fCAP nor u+fCAP induced significant changes of cytotoxicity or inflammation in the lung. However, markers of oxidative stress (heme oxygenase-1 and malondialdehyde were affected by both fCAP and u+fCAP exposure, although not always significantly. Additional analysis revealed heme oxygenase-1 (HO-1 levels that followed a nonmonotonic function with an optimum at around 600 μg/m3 for fCAP. As a systemic response, exposure to u+fCAP and fCAP resulted in significant decreases of the white blood cell concentrations. Conclusion Minor pulmonary and systemic effects are observed after both fine and ultrafine + fine PM exposure. These effects do not linearly correlate with the CAP mass. A greater component of traffic CAP and/or a larger proportion ultrafine PM does not strengthen the absolute effects.

  15. Particle Mechanics

    CERN Document Server

    Collinson, Chris

    1995-01-01

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

  16. Development and testing of a unique carousel wind tunnel to experimentally determine the effect of gravity and the interparticle force on the physics of wind-blown particles

    Science.gov (United States)

    Leach, R. N.; Greeley, Ronald; White, Bruce R.; Iversen, James D.

    1987-01-01

    In the study of planetary aeolian processes the effect of gravity is not readily modeled. Gravity appears in the equations of particle motion along with the interparticle forces but the two are not separable. A wind tunnel that perimits multiphase flow experiments with wind blown particles at variable gravity was built and experiments were conducted at reduced gravity. The equations of particle motion initiation (saltation threshold) with variable gravity were experimentally verified and the interparticle force was separated. A uniquely design Carousel Wind Tunnel (CWT) allows for the long flow distance in a small sized tunnel since the test section if a continuous loop and develops the required turbulent boundary layer. A prototype model of the tunnel where only the inner drum rotates was built and tested in the KC-135 Weightless Wonder 4 zero-g aircraft. Future work includes further experiments with walnut shell in the KC-135 which sharply graded particles of widely varying median sizes including very small particles to see how interparticle force varies with particle size, and also experiments with other aeolian material.

  17. Theoretical and experimental study on the effects of particle size and temperature on the reaction kinetics of cubic nano-Cu2O

    Science.gov (United States)

    Tang, Huanfeng; Huang, Zaiyin; Xiao, Ming; Liang, Min; Chen, Liying; Tan, XueCai

    2017-09-01

    The activities, selectivities, and stabilities of nanoparticles in heterogeneous reactions are size-dependent. In order to investigate the influencing laws of particle size and temperature on kinetic parameters in heterogeneous reactions, cubic nano-Cu2O particles of four different sizes in the range of 40-120 nm have been controllably synthesized. In situ microcalorimetry has been used to attain thermodynamic data on the reaction of Cu2O with aqueous HNO3 and, combined with thermodynamic principles and kinetic transition-state theory, the relevant reaction kinetic parameters have been evaluated. The size dependences of the kinetic parameters are discussed in terms of the established kinetic model and the experimental results. It was found that the reaction rate constants increased with decreasing particle size. Accordingly, the apparent activation energy, pre-exponential factor, activation enthalpy, activation entropy, and activation Gibbs energy decreased with decreasing particle size. The reaction rate constants and activation Gibbs energies increased with increasing temperature. Moreover, the logarithms of the apparent activation energies, pre-exponential factors, and rate constants were found to be linearly related to the reciprocal of particle size, consistent with the kinetic models. The influence of particle size on these reaction kinetic parameters may be explained as follows: the apparent activation energy is affected by the partial molar enthalpy, the pre-exponential factor is affected by the partial molar entropy, and the reaction rate constant is affected by the partial molar Gibbs energy. [Figure not available: see fulltext.

  18. CFD Modelling and Experimental Testing of Thermal Calcination of Kaolinite Rich Clay Particles - An Effort towards Green Concrete

    DEFF Research Database (Denmark)

    Gebremariam, Abraham Teklay

    at inappropriately high temperatures or long retention time will not only waste energy but also decrease the reactivity of the calcines due to possible recrystallization of the reactive phase into a stable crystalline phase. Therefore, it is very crucial to achieve an in-depth understanding of the calcination...... processes in a calciner and develop a useful tool that can aid in design of a smart clay calcination technology, which makes the major objective of this study. In this thesis, a numerical approach is mainly used to investigate the flash calcination of clay particles. A transient one-dimensional particle...... model which fully addresses not only the particle-ambient flow interaction but also the intra-particle processes has been successfully developed in a C++ program to examine calcination of clay particles suspended in a hot gas. The calcination process is also numerically studied using gPROMS (a general...

  19. Numerical Simulation and Experimental Investigation of Multi-function Micro-plasma Jet and Alumina Particle Behaviour

    Directory of Open Access Journals (Sweden)

    Liu Gu

    2016-01-01

    Full Text Available Turbulent flow in multi-function micro-plasma spray, as well as the trajectories and state-changing course of alumina particles in the plasma jet were simulated. The distribution of temperature and velocity of the plasma jet and in-flight alumina particles is discussed. Calculations show that particles are heated and accelerated sufficiently by the plasma flame due to a longer travel time than that of external injection system, therefore, possess higher temperature and velocity. Alumina particles temperature and velocity increase rapidly along the jet axis at the initial stage, but then decrease gradually. The velocity and surface temperature of in-flight alumina particles are measured by Spray Watch-2i system. The velocity and surface temperature of alumina particles measured agree well with the simulation results, confirming that the simulation model is suitable for the prediction of the turbulent flow and the particle characteristics, which also reveals the superiority of the plasma spray gun in this multi-function micro-plasma spraying system.

  20. Kinetic studies of elementary chemical reactions

    Energy Technology Data Exchange (ETDEWEB)

    Durant, J.L. Jr. [Sandia National Laboratories, Livermore, CA (United States)

    1993-12-01

    This program concerning kinetic studies of elementary chemical reactions is presently focussed on understanding reactions of NH{sub x} species. To reach this goal, the author is pursuing experimental studies of reaction rate coefficients and product branching fractions as well as using electronic structure calculations to calculate transition state properties and reaction rate calculations to relate these properties to predicted kinetic behavior. The synergy existing between the experimental and theoretical studies allow one to gain a deeper insight into more complex elementary reactions.

  1. Experimental study of the role of physicochemical surface processing on the IN ability of mineral dust particles

    Directory of Open Access Journals (Sweden)

    D. Niedermeier

    2011-11-01

    Full Text Available During the measurement campaign FROST 2 (FReezing Of duST 2, the Leipzig Aerosol Cloud Interaction Simulator (LACIS was used to investigate the influence of various surface modifications on the ice nucleating ability of Arizona Test Dust (ATD particles in the immersion freezing mode. The dust particles were exposed to sulfuric acid vapor, to water vapor with and without the addition of ammonia gas, and heat using a thermodenuder operating at 250 °C. Size selected, quasi monodisperse particles with a mobility diameter of 300 nm were fed into LACIS and droplets grew on these particles such that each droplet contained a single particle. Temperature dependent frozen fractions of these droplets were determined in a temperature range between −40 °C ≤T≤−28 °C. The pure ATD particles nucleated ice over a broad temperature range with their freezing behavior being separated into two freezing branches characterized through different slopes in the frozen fraction vs. temperature curves. Coating the ATD particles with sulfuric acid resulted in the particles' IN potential significantly decreasing in the first freezing branch (T>−35 °C and a slight increase in the second branch (T≤−35 °C. The addition of water vapor after the sulfuric acid coating caused the disappearance of the first freezing branch and a strong reduction of the IN ability in the second freezing branch. The presence of ammonia gas during water vapor exposure had a negligible effect on the particles' IN ability compared to the effect of water vapor. Heating in the thermodenuder led to a decreased IN ability of the sulfuric acid coated particles for both branches but the additional heat did not or only slightly change the IN ability of the pure ATD and the water vapor exposed sulfuric acid coated particles. In other words, the combination of both sulfuric acid and water vapor being present is a main cause for the ice active surface features of the ATD

  2. Elementary Particles and the Forces of Nature

    OpenAIRE

    Hawking, Stephen W.

    2017-01-01

    Stephen W. Hawking, who was born in 1942 on the anniversary of Galileo’s death, holds Isaac Newton’s chair as Lucasian Professor of Mathematics at the University of Cambridge. Widely regarded as the most brilliant theoretical physicist since Einstein, he is also the author of Black Holes and Baby Universes, published in 1993, as well as numerous scientific papers and books.Посилання:Stephen W. Hawking, A Brief History of Time From the Big Bang to Black Holes, 1988.Kratkaja istorija vremeni. O...

  3. On Witness-Discernibility of Elementary Particles

    NARCIS (Netherlands)

    Linnebo, Ø; Muller, F.A.

    2012-01-01

    In the context of discussions about the nature of ‘identical particles’ and the status of Leibniz’s Principle of the Identity of Indiscernibles in Quantum Mechanics, a novel kind of physical discernibility has recently been proposed, which we call witness-discernibility. We inquire into how

  4. Elementary particles in the service of man

    CERN Multimedia

    1966-01-01

    This article was prepared by the Atomic Energy Research Establishment, Harwell, and the Rutherford Laboratory in the U.K., for a Physics Exhibition in March of this year and is reproduced here with acknowledgement. It is an account of how some of the knowledge gained in the previous generation of our research has already been applied 'in the service of man'.

  5. Elementary Particle Physics at Syracuse. Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Catterall, Simon [Syracuse Univ., NY (United States). Dept. of Physics; Hubisz, Jay [Syracuse Univ., NY (United States). Dept. of Physics; Balachandran, Aiyalam [Syracuse Univ., NY (United States). Dept. of Physics; Schechter, Joe [Syracuse Univ., NY (United States). Dept. of Physics

    2013-01-05

    This final report describes the activities of the high energy theory group at Syracuse University for the period 1 January 2010 through April 30 2013. The research conducted by the group includes lattice gauge theory, non-commutative geometry, phenomenology and mathematical physics.

  6. Nonperturbative mechanism for elementary particle mass generation

    Science.gov (United States)

    Frezzotti, R.; Rossi, G. C.

    2015-09-01

    Taking inspiration from lattice QCD data, we argue that a finite nonperturbative contribution to the quark mass is generated as a consequence of the dynamical phenomenon of spontaneous chiral symmetry breaking, in turn triggered by the explicit breaking of chiral symmetry induced by the critical Wilson term in the action. In pure lattice QCD this mass term cannot be separated from the unavoidably associated linearly divergent contribution. However, if QCD is enlarged to a theory where also a scalar field is present, coupled to an SU(2) doublet of fermions via a Yukawa and a Wilson-like term, then in the phase where the scalar field takes a nonvanishing expectation value, a dynamically generated and "naturally" light fermion mass (numerically unrelated to the expectation value of the scalar field) is conjectured to emerge at a critical value of the Yukawa coupling where the symmetry of the model is maximally enhanced. Masses dynamically generated in this way display a natural hierarchy according to which the stronger is the strongest of the interactions the fermion is subjected to, the larger will be its mass.

  7. The Mathematical Structure of Elementary Particles.

    Science.gov (United States)

    1983-10-01

    Physical Mathematics) *Instituto de Matematica Pura e Aplicada, Estrada Dona Castorina 110, 22460 Rio de Janeiro, Brazil Sponsored by the United...is the basic method of analysis to be employed in this work. *Instituto de Matematica Pura e Aplicada, Estrada Dona Castorina 110, 22460 Rio de Janeiro

  8. A Generalized Curve Approach to Elementary Particles.

    Science.gov (United States)

    1982-01-01

    MPA, Instituto de Matematica Pura e Aplicada , Rio de Janeiro. Sponsored by the United States Army under Contract No. DAAG29-80-C-0041. -. ~ I A...Madison, Wisconsin. IMPA, Instituto de Matematica Pura e Aplicada , Rio de Janeiro. Sponsored by the United States Army under ontract No. DAAGM9-80-C-0041

  9. Elementary particle physics and high energy phenomena

    Energy Technology Data Exchange (ETDEWEB)

    Barker, A.R.; Cumalat, J.P.; de Alwis, S.P.; DeGrand, T.A.; Ford, W.T.; Mahanthappa, K.T.; Nauenberg, U.; Rankin, P.; Smith, J.G.

    1992-06-01

    This report discusses the following research in high energy physics: the properties of the z neutral boson with the SLD detector; the research and development program for the SDC muon detector; the fixed-target k-decay experiments; the Rocky Mountain Consortium for HEP; high energy photoproduction of states containing heavy quarks; and electron-positron physics with the CLEO II and Mark II detectors. (LSP).

  10. FINAL REPORT: GEOMETRY AND ELEMENTARY PARTICLE PHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Singer, Isadore M.

    2008-03-04

    The effect on mathematics of collaborations between high-energy theoretical physics and modern mathematics has been remarkable. Mirror symmetry has revolutionized enumerative geometry, and Seiberg-Witten invariants have greatly simplified the study of four manifolds. And because of their application to string theory, physicists now need to know cohomology theory, characteristic classes, index theory, K-theory, algebraic geometry, differential geometry, and non-commutative geometry. Much more is coming. We are experiencing a deeper contact between the two sciences, which will stimulate new mathematics essential to the physicists’ quest for the unification of quantum mechanics and relativity. Our grant, supported by the Department of Energy for twelve years, has been instrumental in promoting an effective interaction between geometry and string theory, by supporting the Mathematical Physics seminar, postdoc research, collaborations, graduate students and several research papers.

  11. Pressure loss in natural gas pipelines: Experimental studies of gas-particle flow, wall roughness and drag reduction

    Energy Technology Data Exchange (ETDEWEB)

    Strupstad, Andre

    2009-05-15

    Laboratory experiments on air-particle flow were performed in a horizontal once-through flow rig, with internal pipe diameters of 24 mm. Reynolds number was 40000 - 180000, temperatures 20 deg. Celsius and pressure below 2 bara. Spherical polystyrene and magnetite particles with mean diameters from 64 mum to 175 mum were used. The pressure loss in the experiments was best expressed in terms of friction factor. Differential pressure drop gave limited information because reduction in this value was due to change in the gas properties during particle injection. The reduction in the differential pressure was due to the increase in the absolute pressure, which resulted in an increased gas density. This increased density, which with an approximately constant gas mass flow, resulted in a lower volume flow, and thereby a lower gas velocity. A lower gas velocity results in a lower differential pressure. A calculation of the friction factors, which increased, showed that these reductions in the differential pressures were not drag reductions. Roughness measurements were made on three types of surfaces with a stylus instrument: 47 epoxy coated steel surfaces as used in natural gas pipelines, 5 plexiglass surfaces used in our flow experiments, and 9 steel surfaces. The roughness profiles obtained were used to calculate amplitude roughness parameters and texture roughness parameters. Theory of gas-particle drag reduction in pipes was reviewed. Turbulence attenuation was a necessary but not a sufficient condition for drag reduction to occur. Small particle diameter was identified as an important condition for achieving drag reduction. Also, relevant parameters for achieving turbulence attenuation were identified, including the Stokes number, ratio between particle diameter and pipe diameter and the particle Reynolds number. In the flow experiments the gas friction factor increased by up to 16 % with injection of particles as compared to particle free flow. The increase depended

  12. Flow induced particle migration in fresh concrete: Theoretical frame, numerical simulations and experimental results on model fluids

    DEFF Research Database (Denmark)

    Spangenberg, J.; Roussel, N.; Hattel, J.H.

    2012-01-01

    In this paper, we describe and compare the various physical phenomena which potentially lead to flow induced particle migration in concrete. We show that, in the case of industrial casting of concrete, gravity induced particle migration dominates all other potential sources of heterogeneities ind...... the apparent viscosity nor from the plastic viscosity of the suspending phase but from its tangential viscosity. Finally, the transfer of this type of numerical prediction tool to real concrete is discussed....

  13. Experiment and theory in particle physics: Reflections on the discovery of the tau lepton

    Energy Technology Data Exchange (ETDEWEB)

    Perl, M.L.

    1996-08-01

    This article is thoughts from the author on particle physics work from his perspective. It is not a summary of his work on the tau lepton, but rather a look at what makes good science, experimental and theoretical, from his experiences in the field. The section titles give a good summary on the topics the author chooses to touch upon. They are: the state of elementary particle physics; getting good ideas in experimental science; a difficult field; experiments and experimenting; 10% of the money and 30% of the time; the dictatorship of theory; technological dreams; last words.

  14. Abrasive Particle Trajectories and Material Removal Non-Uniformity during CMP and Filtration Characteristics of CMP Slurries - A Simulation and Experimental Study

    Science.gov (United States)

    Rastegar, Vahid

    Nanoscale finishing and planarization are integral process steps in multilevel metallization designs for integrated circuit (IC) manufacturing since it is necessary to ensure local and global surface planarization at each metal layer before depositing the next layer. Chemical mechanical planarization (CMP) has been widely recognized as the most promising technology to eliminate topographic variation and has allowed the construction of multilevel interconnection structures with a more regularly stacked sequence, resulting in better device performance [1]. Understanding fundamental of the CMP mechanisms can offer guidance to the control and optimization of the polishing processes. CMP kinematics based on slurry distribution and particle trajectories have a significant impact on MRR profiles. In this work a mathematical model to describe particle trajectories during chemical mechanical polishing was developed and extended to account for the effect of larger particles, particle location changes due to slurry dispensing and in-situ conditioning. Material removal rate (MRR) and within wafer non-uniformity (WIWNU) were determined based on the calculated particle trajectory densities. Rotary dynamics and reciprocating motion were optimized to obtain best MRR uniformity. Edge-fast MRR profile was discussed based on mechanical aspect of CMP. Using the model, we also investigated the effect of variable rotational speeds of wafer and pad, and of large particles on WIWNU and scratch growth. It was shown that the presence of even a small portion of large particles can deteriorate the WIWNU significantly and also lead to more scratches. Furthermore, it was shown that the in-situ conditioning improves the uniformity of the polished wafers. Furthermore, a combined experimental and computational study of fibrous filters for removal of larger abrasive particles from aqueous dispersions, essential to minimize defects during chemical mechanical polishing, was performed. Dilute aqueous

  15. Vertical pneumatic conveying in dilute and dense-phase flows: experimental study of the influence of particle density and diameter on fluid dynamic behavior

    Directory of Open Access Journals (Sweden)

    Narimatsu C.P.

    2001-01-01

    Full Text Available In this work, the effects of particle size and density on the fluid dynamic behavior of vertical gas-solid transport of Group D particles in a 53.4 mm diameter transport tube were studied. For the conditions tested, the experimental curves of pressure gradient versus air velocity presented a minimum pressure gradient point, which is associated with a change in the flow regime from dense to dilute phase. The increases in particle size from 1.00 to 3.68 mm and in density from 935 to 2500 kg/m³ caused an increase in pressure gradient for the dense-phase transport region, but were not relevant in dilute transport. The transition velocity between dense and dilute flow (Umin also increased with increasing particle density and diameter. An empirical equation was fitted for predicting transition air velocity for the transport of glass spheres. Additional experiments, covering a wider range of conditions and particles properties, are still needed to allow the fitting of a generalized equation for prediction of Umin.

  16. Light microscopic identification and semiquantification of polyethylene particles in methylmethacrylate and paraffin-embedded experimental bone implant specimens

    DEFF Research Database (Denmark)

    Rahbek, O; Kold, S; Overgaard, S

    2005-01-01

    The aim of this study was to evaluate the identification of polyethylene (PE) particles in relatively thick methylmethacrylate (MMA) sections widely used in bone implant research. The sensitivity and specificity were compared between decalcified paraffin-embedded oil red O (ORO) stained and MMA......-embedded sections using polarized light. Furthermore, we introduced a grading system to semiquantify the level of PE particles in peri-implant tissue. Paraffin-embedded and MMA-embedded sections were compared concerning intra-observer agreement of the grading system. Moreover, the semiquantitative assessment...... of particle level was compared between the two section types. We found a sensitivity and specificity of polarized light of 100% for both paraffin ORO-stained and MMA sections. The intra-observer agreement on both types was comparable and acceptable. The ratings of differently processed blocks (MMA...

  17. Experimental studies on particle emissions from cruising ship, their characteristic properties, transformation and atmospheric lifetime in the marine boundary layer

    Directory of Open Access Journals (Sweden)

    A. Petzold

    2008-05-01

    Full Text Available Particle emissions from ship engines and their atmospheric transformation in the marine boundary layer (MBL were investigated in engine test bed studies and in airborne measurements of expanding ship plumes. During the test rig studies, detailed aerosol microphysical and chemical properties were measured in the exhaust gas of a serial MAN B&W seven-cylinder four-stroke marine diesel engine under various load conditions. The emission studies were complemented by airborne aerosol transformation studies in the plume of a large container ship in the English Channel using the DLR aircraft Falcon 20 E-5. Observations from emission studies and plume studies combined with a Gaussian plume dispersion model yield a consistent picture of particle transformation processes from emission to atmospheric processing during plume expansion. Particulate matter emission indices obtained from plume measurements are 8.8±1.0×1015(kg fuel−1 by number for non-volatile particles and 174±43 mg (kg fuel−1 by mass for Black Carbon (BC. Values determined for test rig conditions between 85 and 110% engine load are of similar magnitude. For the total particle number including volatile compounds no emission index can be derived since the volatile aerosol fraction is subject to rapid transformation processes in the plume. Ship exhaust particles occur in the size range Dp<0.3 μm, showing a bi-modal structure. The combustion particle mode is centred at modal diameters of 0.05 μm for raw emissions to 0.10 μm at a plume age of 1 h. The smaller-sized volatile particle mode is centred at Dp≤0.02 μm. From the decay of ship exhaust particle number concentrations in an expanding plume, a maximum plume life time of approx. 24 h is estimated for a well-mixed marine boundary layer.

  18. Experimental assessment and modeling evaluation of the effects of seagrass Posidonia oceanica on flow and particle trapping

    NARCIS (Netherlands)

    Hendriks, I.E.; Sintes, T.; Bouma, T.J.; Duarte, C.M.

    2008-01-01

    Retention of particles in seagrass canopies is usually attributed to only the indirect, attenuating effects canopies have on flow, turbulence and wave action, promoting sedimentation and reducing resuspension within seagrass meadows. Yet recent evidence suggests that seagrasses are also able to

  19. Experimental and computational study of light scattering by irregular particles with extreme refractive indices: hematite and rutile

    NARCIS (Netherlands)

    Muñoz, O.; Volten, H.; Hovenier, J.W.; Min, M.; Shkuratov, Y.G.; Jalava, J.P.; van der Zande, W.J.; Waters, L.B.F.M.

    2006-01-01

    We present measurements of the complete scattering matrix as a function of the scattering angle of randomly oriented irregular hematite and rutile particles. The measurements were made at a wavelength of 632.8 nm in the scattering angle range from 5-174 degrees. Apart from their astronomical

  20. Cloud droplet activation of mixed model HULIS and NaCl particles: Experimental results and κ-Köhler theory

    Science.gov (United States)

    Kristensen, Thomas B.; Prisle, Nønne L.; Bilde, Merete

    2014-02-01

    Significant amounts of humic-like substances (HULIS) are present in marine submicrometer particles. The cloud condensation nuclei (CCN) activation was investigated for marine model particles comprised of Nordic Aquatic Fulvic Acid Reference (NAFA) and sodium chloride (NaCl) in mass ratios of 100:0, 80:20, 50:50, 20:80 and 0:100 respectively. The CCN activity of NAFA was found to be represented by a κ value of 0.028. The CCN activities of the mixed particles were overestimated by volume weighted addition of the κ values of the pure compounds, which indicates that synergistic effects of the mixtures tend to lower the CCN activity. Parameterizations of water activity (aw) and surface tension (σ) versus solute concentration were obtained from measurements on aqueous solutions. The CCN activity was modeled on the basis of the parameterizations of aw and σ using Köhler theory. For the particles containing 50% or more NAFA the model overpredicted the CCN activity compared to observations. Reasonable model results were obtained by assuming a surface tension of pure water.

  1. Gaseous Detectors: Charged Particle Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Hilke, H J

    2011-01-01

    Gaseous Detectors in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.2 Gaseous Detectors' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.2 Gaseous Detectors 3.1.2.1 Introduction 3.1.2.2 Basic Processes 3.1.2.2.1 Gas ionization by charged particles 3.1.2.2.1.1 Primary clusters 3.1.2.2.1.2 Cluster size distribution 3.1.2.2.1.3 Total number of ion pairs 3.1.2.2.1.4 Dependence of energy deposit on particle velocity 3.1.2.2.2 Transport of...

  2. Elementary Teachers' Perceptions of Elementary Principals' Effectiveness

    Science.gov (United States)

    Fridenvalds, Kriss R.

    2012-01-01

    This dissertation examined the beliefs of elementary teachers to determine if their perceptions of effective principal leadership align to transformational leadership theory vis-a-vis the Educational Leadership Policy Standards (ELPS). A phenomenological, single-case study approach was utilized by means of a mixed-methodological, Web-based survey,…

  3. Experimental Study on Ultrafine Particle Removal Performance of Portable Air Cleaners with Different Filters in an Office Room

    Directory of Open Access Journals (Sweden)

    Huan Ma

    2016-01-01

    Full Text Available Size- and time-dependent aerodynamic behaviors of indoor particles, including PM1.0, were evaluated in a school office in order to test the performance of air-cleaning devices using different filters. In-situ real-time measurements were taken using an optical particle counter. The filtration characteristics of filter media, including single-pass efficiency, volume and effectiveness, were evaluated and analyzed. The electret filter (EE medium shows better initial removal efficiency than the high efficiency (HE medium in the 0.3–3.5 μm particle size range, while under the same face velocity, the filtration resistance of the HE medium is several times higher than that of the EE medium. During service life testing, the efficiency of the EE medium decreased to 60% with a total purifying air flow of 25 × 104 m3/m2. The resistance curve rose slightly before the efficiency reached the bottom, and then increased almost exponentially. The single-pass efficiency of portable air cleaner (PAC with the pre-filter (PR or the active carbon granule filter (CF was relatively poor. While PAC with the pre-filter and the high efficiency filter (PR&HE showed maximum single-pass efficiency for PM1.0 (88.6%, PAC with the HE was the most effective at removing PM1.0. The enhancement of PR with HE and electret filters augmented the single-pass efficiency, but lessened the airflow rate and effectiveness. Combined with PR, the decay constant of large-sized particles could be greater than for PACs without PR. Without regard to the lifetime, the electret filters performed better with respect to resource saving and purification improvement. A most penetrating particle size range (MPPS: 0.4–0.65 μm exists in both HE and electret filters; the MPPS tends to become larger after HE and electret filters are combined with PR. These results serve to provide a better understanding of the indoor particle removal performance of PACs when combined with different kinds of filters in

  4. Particle diffusion in an inhomogeneous medium

    Energy Technology Data Exchange (ETDEWEB)

    Bringuier, E, E-mail: eric.bringuier@upmc.fr [UFR de Physique, Universite Pierre et Marie Curie, 4 place Jussieu, 75252 Paris Cedex 05 (France)

    2011-07-15

    This paper is an elementary introduction to particle diffusion in a medium where the coefficient of diffusion varies with position. The introduction is aimed at third-year university courses. We start from a simple model of particles hopping on a discrete lattice, in one or more dimensions, and then take the continuous-space limit so as to obtain the differential equation of diffusion. The discrete-step model is next adapted to investigate diffusion by continuous-length steps; the coefficient of diffusion is related to the mean free path. In both the discrete- and continuous-step models, the diffusion law has the Fokker-Planck (instead of Fick) pattern if the jumps are not biased and occur equally likely in all directions. Lastly, three experimental examples of diffusion in inhomogeneous media are examined; the observed law can be of a Fokker-Planck, Fick or hybrid type.

  5. Quantum harmonic oscillator: an elementary derivation of the energy spectrum

    Science.gov (United States)

    Borghi, Riccardo

    2017-03-01

    An elementary treatment of the quantum harmonic oscillator is proposed. No previous knowledge of linear differential equation theory or Fourier analysis are required, but rather only a few basics of elementary calculus. The pivotal role in our analysis is played by the sole particle localization constraint, which implies square integrability of stationary-state wavefunctions. The oscillator ground-state characterization is then achieved in a way that could be grasped, in principle, even by first-year undergraduates. A very elementary approach to build up and to characterize all higher-level energy eigenstates completes our analysis.

  6. Experimental investigation of pebble flow dynamics using radioactive particle tracking technique in a scaled-down Pebble Bed Modular Reactor (PBMR)

    Energy Technology Data Exchange (ETDEWEB)

    Khane, Vaibhav; Said, I.A.; Al-Dahhan, Muthanna H., E-mail: aldahhanm@mst.edu

    2016-06-15

    Highlights: • Pebble Flow fields at Pebble Bed Modular Reactor was investigated. • Radioactive Particle Tracking (RPT) technique has been used. • Plug flow type velocity profile is suggested at upper cylindrical region. - Abstract: The Pebble Bed Modular Reactor (PBMR) is a type of very-high-temperature reactor (VHTR) that is conceptually very similar to moving bed reactors used in the chemical and petrochemical industries. In a PBMR core, nuclear fuel is in the form of pebbles and moves slowly under the influence of gravity. In this work, an integrated experimental and computational study of granular flow in a scaled-down cold flow PBMR was performed. A continuous pebble re-circulation experimental set-up, mimicking the flow of pebbles in a PBMR was designed and developed. An experimental investigation of pebble flow dynamics in a scaled down test reactor was carried out using a non-invasive radioactive particle tracking (RPT) technique that used a cobalt-60 based tracer to mimic pebbles in terms of shape, size and density. A cross-correlation based position reconstruction algorithm and RPT calibration data were used to obtain results about Lagrangian trajectories, the velocity field, and residence time distributions. The RPT technique results a serve as a benchmark data for assessing contact force models used in the discrete element method (DEM) simulations.

  7. Experimental evidence of false-positive Comet test results due to TiO2 particle--assay interactions.

    Science.gov (United States)

    Rajapakse, Katarina; Drobne, Damjana; Kastelec, Damijana; Marinsek-Logar, Romana

    2013-08-01

    We have studied the genotoxicity of TiO2 particles with a Comet assay on a unicellular organism, Tetrahymena thermophila. Exposure to bulk- or nano-TiO2 of free cells, cells embedded in gel or nuclei embedded in gel, all resulted in a positive Comet assay result but this outcome could not be confirmed by cytotoxicity measures such as lipid peroxidation, elevated reactive oxygen species or cell membrane composition. Published reports state that in the absence of cytotoxicity, nano- and bulk-TiO2 genotoxicity do not occur directly, and a possible explanation of our Comet assay results is that they are false positives resulting from post festum exposure interactions between particles and DNA. We suggest that before Comet assay is used for nanoparticle genotoxicity testing, evidence for the possibility of post festum exposure interactions should be considered. The acellular Comet test described in this report can be used for this purpose.

  8. W.K.H. Panofsky Prize in Experimental Particle Physics Talk: Kaons Redux- Seeking New Physics with Rare Decays of Kaons

    Science.gov (United States)

    Bryman, Douglas

    2011-04-01

    Studies of rare decays of kaons have been important in establishing the current picture of particle physics and in constraining hypothetical new approaches which go beyond the Standard Model to deal with its known deficiencies. Experimental capabilities have increased in concert with theoretical understanding making this approach to searching for new physics more viable than ever and essential, even in the era of the LHC. In this talk, I will discuss the most interesting and incisive rare kaon decay experiments, particularly K+ -->π+ ν ν andKL0 -->π0 ν ν , emphasizing the prospects for major advancements in the near term and at future high intensity proton accelerators.

  9. Balancing particle absorption with structural support of the muon beam stop in muons-to-electrons experimental chamber

    Energy Technology Data Exchange (ETDEWEB)

    Majewski, Ryan [Northern Illinois Univ., DeKalb, IL (United States)

    2013-01-01

    The Mu2e experiment at Fermi National Accelerator Laboratory is seeking a full conversion from muon to electron. The design for Mu2e is based off MECO, another proposed experiment that sought a full conversion from muon to electron at Brookhaven National Laboratory in the 1990s. Mu2e will provide sensitivity that is four times the sensitivity of the previous experiment, SINDRUM II. Discovering muon to electron conversions could help explain physics beyond the standard model of the particle physics.

  10. Experimental Study of Fouling and Cleaning of Sintered Stainless Steel Membrane in Electro-Microfiltration of Calcium Salt Particles

    Directory of Open Access Journals (Sweden)

    Frank G. F. Qin

    2011-05-01

    Full Text Available Sintered stainless steel (SSS microfiltration membranes, which served as electrode directly, were used for the experiment of separating Alamin, a calcium salt and protein containing particles, found in dairy processing. Fouling and cleaning of the SSS membranes under the application of an external electric field were studied. The imposed electric field was found, diverging the pH of permeate and retentate. This in turn altered the solubility of the calcium salt and impacted the performance of electro microfiltration membrane. Using electric field as an enhanced cleaning-in-place (CIP method in back flushing SSS membrane was also studied.

  11. Experimental observations of non-equilibrium gas-particle partitioning of PAHs in an outdoor smog chamber

    Energy Technology Data Exchange (ETDEWEB)

    Coe, D.L.; Kamens, R.M. [Univ. of North Carolina, Chapel Hill, NC (United States). Dept. of Environmental Sciences and Engineering

    1994-12-31

    To study non-equilibrium gas-particle partitioning of various PAHs, three specially designed smog chamber experiments were conducted (October 1993, January 1994, and February 1994). Automobile diesel exhaust was injected for five minutes into a 190 m{sup 3} Teflon film chamber and allowed to age during the night at temperatures below 15 C. A large denuder system was utilized during the injection period in order to remove PAH vapors from the injection stream. Thus, PAH-laden particles were observed to off-gas in the near absence of vapor phase PAHs during the initial stages of the 8-hour experiments. The large denuder was designed as a parallel plate system, made of activated charcoal impregnated filters. It was characterized to remove greater than 90% of PAH vapors from the diesel injection system. During the experiments, air samples were collected in the chamber at 20-minute intervals for the first 2 hours, and hourly thereafter. The sampling system consisted of an XAD-4 coated annular denuder, followed by a quartz-fiber filter, which is then followed by a second annular denuder. Sample extracts were analyzed on Hewlett-Packard GC/MS. Results from these experiments are compared to output from a radial diffusion computer model, detailed in another paper (``Modeling the Mass Transfer of Semi-Volatile Organics in Combustion Aerosols`` by Jay R. Odum and Richard M. Kamens).

  12. Experimental Measurements of the Secondary Electron Yield in the Experimental Measurement of the Secondary Electron Yield in the PEP-II Particle Accelerator Beam Line

    Energy Technology Data Exchange (ETDEWEB)

    Pivi, M.T.F.; Collet, G.; King, F.; Kirby, R.E.; Markiewicz, T.; Raubenheimer, T.O.; Seeman, J.; /SLAC; Le Pimpec, F.; /PSI, Villigen

    2010-08-25

    Beam instability caused by the electron cloud has been observed in positron and proton storage rings and it is expected to be a limiting factor in the performance of the positron Damping Ring (DR) of future Linear Colliders (LC) such as ILC and CLIC. To test a series of promising possible electron cloud mitigation techniques as surface coatings and grooves, in the Positron Low Energy Ring (LER) of the PEP-II accelerator, we have installed several test vacuum chambers including (i) a special chamber to monitor the variation of the secondary electron yield of technical surface materials and coatings under the effect of ion, electron and photon conditioning in situ in the beam line; (ii) chambers with grooves in a straight magnetic-free section; and (iii) coated chambers in a dedicated newly installed 4-magnet chicane to study mitigations in a magnetic field region. In this paper, we describe the ongoing R&D effort to mitigate the electron cloud effect for the LC damping ring, focusing on the first experimental area and on results of the reduction of the secondary electron yield due to in situ conditioning.

  13. CO2 cooling for particle physics detectors

    NARCIS (Netherlands)

    Colijn, A.P.; Verlaat, B.

    2010-01-01

    A good cooling system is of crucial importance for particle and radiation detector systems that are used in elementary particle physics. In addition to the "normal" design considerations for a cooling system, the systems used in particle detectors are subject to additional unusual constraints. At

  14. Experimental investigation of the dynamics of a hybrid morphing wing: time resolved particle image velocimetry and force measures

    Science.gov (United States)

    Jodin, Gurvan; Scheller, Johannes; Rouchon, Jean-François; Braza, Marianna; Mit Collaboration; Imft Collaboration; Laplace Collaboration

    2016-11-01

    A quantitative characterization of the effects obtained by high frequency-low amplitude trailing edge actuation is performed. Particle image velocimetry, as well as pressure and aerodynamic force measurements, are carried out on an airfoil model. This hybrid morphing wing model is equipped with both trailing edge piezoelectric-actuators and camber control shape memory alloy actuators. It will be shown that this actuation allows for an effective manipulation of the wake turbulent structures. Frequency domain analysis and proper orthogonal decomposition show that proper actuating reduces the energy dissipation by favoring more coherent vortical structures. This modification in the airflow dynamics eventually allows for a tapering of the wake thickness compared to the baseline configuration. Hence, drag reductions relative to the non-actuated trailing edge configuration are observed. Massachusetts Institute of Technology.

  15. Experimental and Particle-Tracking Model Analysis of Anomalous Transport and Sorption of Nickel in Natural Soil Columns

    Science.gov (United States)

    Edery, Y.; Rubin, S.; Dror, I.; Berkowitz, B.

    2012-12-01

    Nickel migration measured in laboratory-scale, natural soil column experiments is shown to display anomalous (non-Fickian) transport and non-equilibrium adsorption and desorption patterns. Similar experiments using a conservative tracer also exhibit anomalous behavior. In parallel batch experiments, adsorption and desorption isotherms demonstrate hysteresis, indicating some permanent adsorption. While adsorption is described by the Langmuir isotherm, equilibrium concentrations are higher than those predicted by the same model for desorption. Furthermore, batch and flow-through column experiments show the occurrence of ion exchange of nickel with magnesium and potassium in the soil; aluminum and other ion concentrations are also affected by the presence of nickel. Strong retention of nickel during transport in soil columns leads to delayed initial breakthrough (~40 pore volumes), slow increase in concentration, and extended concentration tailing at long times. Standard models, including two-site non-equilibrium formulations, fail to capture these features quantitatively. We describe the mechanisms of transport and adsorption/desorption in terms of a continuous time random walk (CTRW) model, and use a particle tracking formulation to simulate the nickel migration in the column. This approach allows us to capture the non-Fickian transport and the subtle local effects of adsorption and desorption. The model uses transport parameters estimated from the conservative tracer and, as a starting point, adsorption/desorption parameters based on the batch experiments to account for the reactions. It is shown that the batch parameters under-estimate the actual adsorption in the column. The CTRW particle tracking model is shown to capture both the full evolution of the measured breakthrough curve and the measured spatial concentration profile. Analysis of these results provides further understanding of the interaction and dynamics between transport and sorption mechanisms in

  16. Literature in Focus: "Axions: Theory, Cosmology, and Experimental Searches"

    CERN Multimedia

    2009-01-01

    Axions are peculiar hypothetical particles that could both solve the CP problem of quantum chromodynamics and at the same time account for the dark matter of the universe. Based on a series of lectures by world experts in this field held at CERN, this volume provides a pedagogical introduction to the theory, cosmology and astrophysics of these fascinating particles and gives an up-to-date account of the status and prospect of ongoing and planned experimental searches. Learners and practitioners of astroparticle physics will find in this book both a concise introduction and a current reference work to a showcase topic that connects the "inner space" of the elementary particle world with the "outer space" of the universe at large. The book will be presented by Markus Kuster. "Axions: Theory, Cosmology, and Experimental Searches", edited by M. Kuster (Technische Universität Darmstadt), G. Raffelt (Max-Planck-Institu...

  17. Progress report of a research program in experimental high energy physics

    Energy Technology Data Exchange (ETDEWEB)

    Lanou, R.E. Jr.; Cutts, D.

    1990-07-01

    An experimental program in strong and electro-weak interaction physics of elementary particles is being carried out using electronic detection techniques. Experiments have been performed at Brown, Brookhaven, and Fermilab. The work described in this report by the Electronic Detector Group addresses the following: neutrino interactions and intrinsic properties, preparations for experiments ( D--ZERO'') at the FNAL 2 TeV {bar p}p Collider, new detection techniques for neutrino properties.

  18. An introduction to particle physics and the standard model

    CERN Document Server

    Mann, Robert

    2010-01-01

    … thoroughly recommended for a final-year specialist or first-year postgraduate study level especially for those engaged in experimental high energy physics research. The author has performed an excellent service in making accessible the language and results of field theory applied to elementary particle physics.-John J. Quenby, Contemporary Physics, 52, 2011The first chapter shows how clearly the author can write and even though the subject matter gets more complex through the book, the clarity continues. … giv[es] readers greater insights into how the maths and the reality match (or don't ma

  19. Experimental study of the response functions of direct-reading instruments measuring surface-area concentration of airborne nanostructured particles

    Energy Technology Data Exchange (ETDEWEB)

    Bau, Sebastien; Witschger, Olivier [Institut National de Recherche et de Securite, INRS, Laboratoire de Metrologie des Aerosols, Rue du Morvan, CS 60027, 54519 Vandoeuvre Cedex (France); Gensdarmes, Francois [Institut de Radioprotection et de Surete Nucleaire, IRSN, Laboratoire de Physique et de Metrologie des Aerosols, BP 68, 91192 Gif-sur-Yvette Cedex (France); Thomas, Dominique [Laboratoire des Sciences du Genie Chimique, LSGC/CNRS, Nancy Universite, BP 2041, 54001 Nancy Cedex (France)], E-mail: sebastien.bau@inrs.fr

    2009-05-01

    An increasing number of experimental and theoretical studies focus on airborne nanoparticles (NP) in relation with many aspects of risk assessment to move forward our understanding of the hazards, the actual exposures in the workplace, and the limits of engineering controls and personal protective equipment with regard to NP. As a consequence, generating airborne NP with controlled properties constitutes an important challenge. In parallel, toxicological studies have been carried out, and most of them support the concept that surface-area could be a relevant metric for characterizing exposure to airborne NP. To provide NP surface-area concentration measurements, some direct-reading instruments have been designed, based on attachment rate of unipolar ions to NP by diffusion. However, very few information is available concerning the performances of these instruments and the parameters that could affect their responses. In this context, our work aims at characterizing the actual available instruments providing airborne NP surface-area concentration. The instruments (a- LQ1-DC, Matter Engineering; b-AeroTrak{sup x2122} 9000, TSI; c- NSAM, TSI model 3550;) are thought to be relevant for further workplace exposure characterization and monitoring. To achieve our work, an experimental facility (named CAIMAN) was specially designed, built and characterized.

  20. Numerical simulation and experimental study on Resonant Acoustic Chambers-For novel, high-efficiency nuclear particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Wang Jing; Archambault, Brian [School of Nuclear Engineering, Purdue University, West Lafayette, IN (United States); Xu, Yiban [Westinghouse Electric Company, Cranberry Township, PA, 16066 (United States); Taleyarkhan, Rusi P., E-mail: rusi@purdue.ed [School of Nuclear Engineering, Purdue University, West Lafayette, IN (United States)

    2010-11-15

    Acoustic-structural-electromagnetic coupled models have been successfully set up for Resonant Acoustic Chambers (RACs). RACs have important applications in several areas such as radiation detection, sonoluminescence and sonofusion. The goal of this undertaking was able to simulate transient acoustically driven metastable states and structural responses so that the designs of RACs can be optimized for advanced applications. The simulation predictions have been benchmarked with experimental data in two designs of RACs, Open Chamber System (OCS) and Closed Chamber System (CCS). A framework was developed for benchmarking and validating the predicted resonant frequency and oscillatory pressure mapping profiles with and without scattering centers. Experiments were conducted with and without external neutron-induced cavitation bubble clusters. Comparison of measurements versus experimental data demonstrated the applicability of the modeling-cum-simulation framework. Studies have provided insights into the significant and complex influences of fluid-structure-electromagnetic coupling and on the influence of scattering center inclusions on the system's acoustic responses. The framework appears reasonable for design of advanced, high-powered RACs; however, significant technical challenges remain with respect to capturing the overall system performance upon evolution and transport of transient bubble clusters.

  1. Experimental Testing of the Effects of Fine Particles on the Properties of the Self-Compacting Lightweight Concrete

    Directory of Open Access Journals (Sweden)

    Sandra Juradin

    2012-01-01

    Full Text Available The self-compacting lightweight concrete (SCLC is a combination of the Self compacting concrete (SCC and the Lightweight concrete. It combines all the good properties of those two materials and is extremely convenient for the construction of buildings that require low mass and do not require high compressive strength, for example restoration works in old structures (e.g., replacement of wooden floors, prefabricated elements that require transportation, and for structures and elements where the concrete surface should be visible. In this paper the effect of the amount of fine particles on the properties of the self-compacting lightweight concrete (SCLC in the fresh and hardened state was explored. For this purpose, sets of specimens with different combinations of admixtures of silica fume, fly ash, and filler were prepared and tested. Slump flow and flow time of fresh concrete, as well as the dynamic elastic modulus and compressive strength of hardened concrete, were measured at different ages of concrete. The processes of manufacturing and methods of testing are described, as well as the obtained results.

  2. Removal of arsenic(III) from water by magnetic binary oxide particles (MBOP): Experimental studies on fixed bed column.

    Science.gov (United States)

    Dhoble, Rajesh M; Maddigapu, Pratap Reddy; Rayalu, Sadhana S; Bhole, A G; Dhoble, Ashwinkumar S; Dhoble, Shubham R

    2017-01-15

    Magnetic binary oxide particles (MBOP) were prepared by template method using chitosan in the laboratory for the removal of As(III) from water. The prepared MBOP has super paramagnetic property which is sufficient for magnetic separation. Column study was performed at two different flow rates of 2.0ml/min and 5.0ml/min and comparison was made with regenerated MBOP, commercial activated carbon and commercial activated alumina. It is observed that fresh MBOP has higher breakthrough time and capacity than regenerated MBOP by a factor of 1.25 and 1.37 respectively. In Logit method, the values of K (adsorption rate constant) and N (adsorption capacity coefficient) were obtained as 0.2066 (L/mgh) and 1014(mg/L) for 5.0ml/min flow rate. All the drinking water parameters are within the limit of BIS 10500-2012. Toxicity characteristic leaching procedure (TCLP) and semi dynamic tests were performed for the mix ratios of 01:02:01, 01:02:05 and 01:02:10 and were found safe for the disposal. Copyright © 2016. Published by Elsevier B.V.

  3. Experimental Investigation of Performance and emission characteristics of Various Nano Particles with Bio-Diesel blend on Di Diesel Engine

    Science.gov (United States)

    Karthik, N.; Goldwin Xavier, X.; Rajasekar, R.; Ganesh Bairavan, P.; Dhanseelan, S.

    2017-05-01

    Present study provides the effect of Zinc Oxide (ZnO) and Cerium Oxide (CeO2) nanoparticles additives on the Performance and emission uniqueness of Jatropha. Jatropha blended fuel is prepared by the emulsification technique with assist of mechanical agitator. Nano particles (Zinc Oxide (ZnO)) and Cerium Oxide (CeO2)) mixed with Jatropha blended fuel in mass fraction (100 ppm) with assist of an ultrasonicator. Experiments were conducted in single cylinder constant speed direct injection diesel engine for various test fuels. Performance results revealed that Brake Thermal Efficiency (BTE) of Jatropha blended Cerium Oxide (B20CE) is 3% and 11% higher than Jatropha blended zinc oxide (B20ZO) and Jatropha blended fuel (B20) and 4% lower than diesel fuel (D100) at full load conditions. Emission result shows that HC and CO emissions of Jatropha blended Cerium Oxide (B20CE) are (6%, 22%, 11% and 6%, 15%, 12%) less compared with Jatropha blended Zinc Oxide (B20ZO), diesel (D100) and Jatropha blended fuel (B20) at full load conditions. NOx emissions of Jatropha blended Cerium Oxide is 1 % higher than diesel fuel (D100) and 2% and 5% lower than Jatropha blended Zinc Oxide, and jatropha blended fuel.

  4. Describing Elementary Certification Methods across the Elementary Music Career Cycle

    Science.gov (United States)

    Svec, Christina L.

    2017-01-01

    The purpose of the study was to describe elementary music method choice and certification method choice overall and across the elementary music career cycle. Participants (N = 254) were categorized as Level I or Elementary Division in a southwestern music education association database. The questionnaire included 25 four-point Likert-type items…

  5. Contrasting impact of organic and inorganic nanoparticles and colloids on the behavior of particle-reactive elements in tropical estuaries: An experimental study

    Science.gov (United States)

    Merschel, Gila; Bau, Michael; Dantas, Elton Luiz

    2017-01-01

    Estuarine processes may affect the flux of dissolved organic carbon (DOC), iron and other particle-reactive elements such as the rare earth elements and yttrium (REY), into the ocean via salt-induced coagulation and subsequent removal of river-borne (nano-)particles and colloids. We experimentally assessed the impact of the admixture of seawater on DOC, Fe and REY associated with inorganic and organic nanoparticles and colloids (NPCs) present in tropical rivers, using Rio Solimões and Rio Negro, which are particularly rich in inorganic and organic NPCs, respectively, as river water endmembers. Similar to the conservative elements Sr, Rb and U, DOC behaves conservatively in all mixing experiments, whereas strong removal of Fe and REY (and preferential removal of light over heavy REY and of Ce relative to La and Pr) is confined to experiments with inorganic NPC-rich Rio Solimões water. This removal already occurs at very low salinity and is due to the aggregation of the inorganic NPCs. However, REY removal efficiency increases gradually with increasing salinity, which is in marked contrast to DOC-poor Arctic river waters from which REY removal at lowest salinity is significantly stronger. This suggests that the DOC concentrations in the water have a profound impact on the estuarine mixing behavior of particle-reactive elements. In marked contrast to the Rio Solimões mixing experiment, Fe and the REY in experiments with Rio Negro water behave similarly to DOC and mix conservatively with seawater, indicating that the organic NPCs, most of which are humic and fulvic acids, and their associated trace elements are much less susceptible to coagulation and estuarine removal than inorganic ones. Even at higher salinities, estuarine REY removal from inorganic NPC-rich Rio Solimões water significantly exceeds REY removal from organic NPC-rich Rio Negro water. Hence, the combination of higher element concentrations in and of less estuarine removal from organic NPC

  6. Experimental study of vorticity-strain rate interaction in turbulent partially premixed jet flames using tomographic particle image velocimetry

    Science.gov (United States)

    Coriton, Bruno; Frank, Jonathan H.

    2016-02-01

    In turbulent flows, the interaction between vorticity, ω, and strain rate, s, is considered a primary mechanism for the transfer of energy from large to small scales through vortex stretching. The ω-s coupling in turbulent jet flames is investigated using tomographic particle image velocimetry (TPIV). TPIV provides a direct measurement of the three-dimensional velocity field from which ω and s are determined. The effects of combustion and mean shear on the ω-s interaction are investigated in turbulent partially premixed methane/air jet flames with high and low probabilities of localized extinction as well as in a non-reacting isothermal air jet with Reynolds number of approximately 13 000. Results show that combustion causes structures of high vorticity and strain rate to agglomerate in highly correlated, elongated layers that span the height of the probe volume. In the non-reacting jet, these structures have a more varied morphology, greater fragmentation, and are not as well correlated. The enhanced spatiotemporal correlation of vorticity and strain rate in the stable flame results in stronger ω-s interaction characterized by increased enstrophy and strain-rate production rates via vortex stretching and straining, respectively. The probability of preferential local alignment between ω and the eigenvector of the intermediate principal strain rate, s2, which is intrinsic to the ω-s coupling in turbulent flows, is larger in the flames and increases with the flame stability. The larger mean shear in the flame imposes a preferential orientation of ω and s2 tangential to the shear layer. The extensive and compressive principal strain rates, s1 and s3, respectively, are preferentially oriented at approximately 45° with respect to the jet axis. The production rates of strain and vorticity tend to be dominated by instances in which ω is parallel to the s1 ¯-s2 ¯ plane and orthogonal to s3 ¯.

  7. Deproteinized bovine bone mineral particles and osseointegration of implants without primary bone contact: an experimental study in dogs.

    Science.gov (United States)

    Sivolella, Stefano; Bressan, Eriberto; Salata, Luiz A; Quiñones, Maria E; Lang, Niklaus P; Botticelli, Daniele

    2014-03-01

    To evaluate the influence on osseointegration of Deproteinized bovine bone mineral (DBBM) particles used to fill defects of at least 1 mm around implants having no primary contact with bone. Premolars and first molars were extracted bilaterally from the mandible of six Labrador dogs. After 3 months of healing, mucoperiosteal full-thickness flaps were elevated, and one recipient site was prepared in the molar region of each hemi-mandible to place implants. These were installed with a deliberate circumferential and periapical space to the bone walls of 1.2 mm. All implants were stabilized with passive fixation plates to maintain the implants in situ and without any contact with the implant bed. The control sites were left to be filled with coagulum, while at the test sites, the residual gap was filled with DBBM. After 3 months of submerged healing, the animals were sacrificed. Ground sections were prepared and analyzed histomorphometrically. Mineralized bone-to-implant contact was 4.0% and 3.9% for control and test sites, respectively. The width of the residual defects was 0.48 mm and 0.88 mm at the control and test sites, respectively. The percentage of implant surface covered by a layer of dense connective tissue of 0.12 mm of width on average was 84.9% and 88.5% at the control and test sites, respectively. A minor and not predictable degree of contact or distance osteogenesis was obtained on the implant surface when primary contact of the implant surface with the implant bed had deliberately been avoided. DBBM grafting of the artificial gap did not favor osseointegration. Neither did it enhance the ability to bridge the gap with newly formed bone in an artificial defect wider than 1 mm. © 2013 John Wiley & Sons A/S. Published by Blackwell Publishing Ltd.

  8. Elementary topology problem textbook

    CERN Document Server

    Viro, O Ya; Netsvetaev, N Yu; Kharlamov, V M

    2008-01-01

    This textbook on elementary topology contains a detailed introduction to general topology and an introduction to algebraic topology via its most classical and elementary segment centered at the notions of fundamental group and covering space. The book is tailored for the reader who is determined to work actively. The proofs of theorems are separated from their formulations and are gathered at the end of each chapter. This makes the book look like a pure problem book and encourages the reader to think through each formulation. A reader who prefers a more traditional style can either find the pr

  9. Elementary number theory

    CERN Document Server

    Dudley, Underwood

    2008-01-01

    Ideal for a first course in number theory, this lively, engaging text requires only a familiarity with elementary algebra and the properties of real numbers. Author Underwood Dudley, who has written a series of popular mathematics books, maintains that the best way to learn mathematics is by solving problems. In keeping with this philosophy, the text includes nearly 1,000 exercises and problems-some computational and some classical, many original, and some with complete solutions. The opening chapters offer sound explanations of the basics of elementary number theory and develop the fundamenta

  10. Logic in elementary mathematics

    CERN Document Server

    Exner, Robert M

    2011-01-01

    This applications-related introductory treatment explores facets of modern symbolic logic useful in the exposition of elementary mathematics. The authors convey the material in a manner accessible to those trained in standard elementary mathematics but lacking any formal background in logic. Topics include the statement calculus, proof and demonstration, abstract mathematical systems, and the restricted predicate calculus. The final chapter draws upon the methods of logical reasoning covered in previous chapters to develop solutions of linear and quadratic equations, definitions of order and

  11. Elementary Thermal Operations

    DEFF Research Database (Denmark)

    Lostaglio, Matteo; Alhambra, Álvaro M.; Perry, Christopher

    2018-01-01

    To what extent do thermodynamic resource theories capture physically relevant constraints? Inspired by quantum computation, we define a set of elementary thermodynamic gates that only act on 2 energy levels of a system at a time. We show that this theory is well reproduced by a Jaynes-Cummings in......To what extent do thermodynamic resource theories capture physically relevant constraints? Inspired by quantum computation, we define a set of elementary thermodynamic gates that only act on 2 energy levels of a system at a time. We show that this theory is well reproduced by a Jaynes...

  12. Elementary classical hydrodynamics

    CERN Document Server

    Chirgwin, B H; Langford, W J; Maxwell, E A; Plumpton, C

    1967-01-01

    Elementary Classical Hydrodynamics deals with the fundamental principles of elementary classical hydrodynamics, with emphasis on the mechanics of inviscid fluids. Topics covered by this book include direct use of the equations of hydrodynamics, potential flows, two-dimensional fluid motion, waves in liquids, and compressible flows. Some general theorems such as Bernoulli's equation are also considered. This book is comprised of six chapters and begins by introducing the reader to the fundamental principles of fluid hydrodynamics, with emphasis on ways of studying the motion of a fluid. Basic c

  13. Experimental investigation and theoretical calculation of {sup 3}He-particle induced nuclear reactions on cadmium up to 27 MeV

    Energy Technology Data Exchange (ETDEWEB)

    Ali, B.M. [Physics Department (Cyclotron Facility), Nuclear Research Centre, Atomic Energy Authority, Cairo 13759 (Egypt); Al-Abyad, M., E-mail: alabyad_m@yahoo.com [Physics Department (Cyclotron Facility), Nuclear Research Centre, Atomic Energy Authority, Cairo 13759 (Egypt); Seddik, U. [Physics Department (Cyclotron Facility), Nuclear Research Centre, Atomic Energy Authority, Cairo 13759 (Egypt); El-Kameesy, S.U. [Physics Department, Faculty of Science, Ain Shams University, Cairo (Egypt); Ditrói, F.; Takács, S.; Tárkányi, F. [Institute for Nuclear Research, Hungarian Academy of Sciences (ATOMKI), Debrecen H4026 (Hungary)

    2014-02-15

    Excitation functions of {sup 3}He-particle induced nuclear reactions on natural cadmium were measured using the standard stacked foil technique and high resolution gamma-ray spectroscopy. From their threshold energies up to 27 MeV, cross-sections for {sup nat}Cd({sup 3}He,xn){sup 117m,113,111,110}Sn, {sup nat}Cd({sup 3}He,xnp){sup 117m,g,116m,115m,114m,113m,111,110m,g,109,108,107}In, and {sup nat}Cd({sup 3}He,X){sup 115g,111m}Cd reactions were measured. The nuclear codes TALYS, and EMPIRE-3,1 were used to describe the formation of these products. The present data were compared to theoretical results and to the available experimental data. Integral yields for some important radioisotopes were determined.

  14. Experimental evidence of formation of transparent exopolymer particles (TEP) and POC export provoked by dust addition under current and high pCO2 conditions.

    Science.gov (United States)

    Louis, Justine; Pedrotti, Maria Luiza; Gazeau, Frédéric; Guieu, Cécile

    2017-01-01

    The evolution of organic carbon export to the deep ocean, under anthropogenic forcing such as ocean warming and acidification, needs to be investigated in order to evaluate potential positive or negative feedbacks on atmospheric CO2 concentrations, and therefore on climate. As such, modifications of aggregation processes driven by transparent exopolymer particles (TEP) formation have the potential to affect carbon export. The objectives of this study were to experimentally assess the dynamics of organic matter, after the simulation of a Saharan dust deposition event, through the measurement over one week of TEP abundance and size, and to evaluate the effects of ocean acidification on TEP formation and carbon export following a dust deposition event. Three experiments were performed in the laboratory using 300 L tanks filled with filtered seawater collected in the Mediterranean Sea, during two 'no bloom' periods (spring at the start of the stratification period and autumn at the end of this stratification period) and during the winter bloom period. For each experiment, one of the two tanks was acidified to reach pH conditions slightly below values projected for 2100 (~ 7.6-7.8). In both tanks, a dust deposition event of 10 g m-2 was simulated at the surface. Our results suggest that Saharan dust deposition triggered the abiotic formation of TEP, leading to the formation of organic-mineral aggregates. The amount of particulate organic carbon (POC) exported was proportional to the flux of lithogenic particles to the sediment traps. Depending on the season, the POC flux following artificial dust deposition ranged between 38 and 90 mg m-2 over six experimental days. Such variability is likely linked to the seasonal differences in the quality and quantity of TEP-precursors initially present in seawater. Finally, these export fluxes were not significantly different at the completion of the three experiments between the two pH conditions.

  15. Submillimetre-sized dust aggregate collision and growth properties. Experimental study of a multi-particle system on a suborbital rocket

    Science.gov (United States)

    Brisset, J.; Heißelmann, D.; Kothe, S.; Weidling, R.; Blum, J.

    2016-08-01

    Context. In the very first steps of the formation of a new planetary system, dust agglomerates grow inside the protoplanetary disk that rotates around the newly formed star. In this disk, collisions between the dust particles, induced by interactions with the surrounding gas, lead to sticking. Aggregates start growing until their sizes and relative velocities are high enough for collisions to result in bouncing or fragmentation. With the aim of investigating the transitions between sticking and bouncing regimes for colliding dust aggregates and the formation of clusters from multiple aggregates, the Suborbital Particle and Aggregation Experiment (SPACE) was flown on the REXUS 12 suborbital rocket. Aims: The collisional and sticking properties of sub-mm-sized aggregates composed of protoplanetary dust analogue material are measured, including the statistical threshold velocity between sticking and bouncing, their surface energy and tensile strength within aggregate clusters. Methods: We performed an experiment on the REXUS 12 suborbital rocket. The protoplanetary dust analogue materials were micrometre-sized monodisperse and polydisperse SiO2 particles prepared into aggregates with sizes around 120 μm and 330 μm, respectively and volume filling factors around 0.37. During the experimental run of 150 s under reduced gravity conditions, the sticking of aggregates and the formation and fragmentation of clusters of up to a few millimetres in size was observed. Results: The sticking probability of the sub-mm-sized dust aggregates could be derived for velocities decreasing from ~22 to 3 cm s-1. The transition from bouncing to sticking collisions happened at 12.7+2.1-1.4 cm s-1 for the smaller aggregates composed of monodisperse particles and at 11.5+1.9-1.3 and 11.7+1.9-1.3 cm s-1 for the larger aggregates composed of mono- and polydisperse dust particles, respectively. Using the pull-off force of sub-mm-sized dust aggregates from the clusters, the surface energy of the

  16. The Phase Space Elementary Cell in Classical and Generalized Statistics

    Directory of Open Access Journals (Sweden)

    Piero Quarati

    2013-10-01

    Full Text Available In the past, the phase-space elementary cell of a non-quantized system was set equal to the third power of the Planck constant; in fact, it is not a necessary assumption. We discuss how the phase space volume, the number of states and the elementary-cell volume of a system of non-interacting N particles, changes when an interaction is switched on and the system becomes or evolves to a system of correlated non-Boltzmann particles and derives the appropriate expressions. Even if we assume that nowadays the volume of the elementary cell is equal to the cube of the Planck constant, h3, at least for quantum systems, we show that there is a correspondence between different values of h in the past, with important and, in principle, measurable cosmological and astrophysical consequences, and systems with an effective smaller (or even larger phase-space volume described by non-extensive generalized statistics.

  17. Sports in elementary school

    NARCIS (Netherlands)

    Wouter de Groot; Ben Moolenaar; Eralt Boers; dr. Remo Mombarg

    2016-01-01

    The aim of the project is stimulating sport participation among elementary school children in the province of Friesland. The ultimate aim is to provide three hours of physical education, provided by an physical education specialist, plus two extra hours of sport activities. Part one is about

  18. Elementary School Principal Effectiveness.

    Science.gov (United States)

    Cross, Ray

    A review of research linking elementary principal "antecedents" (defined as traits), behaviors, school conditions, and student outcomes furnishes few supportable generalizations. The studies relating principal antecedents with behavior and principal antecedents with organizational variables reveals that the trait theory of leadership has…

  19. Vision in elementary mathematics

    CERN Document Server

    Sawyer, W W

    2003-01-01

    Sure-fire techniques of visualizing, dramatizing, and analyzing numbers promise to attract and retain students' attention and understanding. Topics include basic multiplication and division, algebra, word problems, graphs, negative numbers, fractions, many other practical applications of elementary mathematics. 1964 ed. Answers to Problems.

  20. Effect of airborne-particle abrasion on dentin with experimental niobophosphate bioactive glass on the microtensile bond strength of resin cements.

    Science.gov (United States)

    Carvalho, Edilausson Moreno; Lima, Darlon Martins; Carvalho, Ceci Nunes; Loguercio, Alessandro Dourado; Martinelli, José Roberto; Bauer, José

    2015-04-01

    The objective of this study was to evaluate the microtensile bond strength (μTBS) of two resin cements bonded to dentin pre-treated with experimental niobophosphate bioactive glass (NBG). The experimental bioactive glass was prepared by mixing different amounts of NbO5; (NH4)2HP4; CaO; Na2CO3. The particle size distribution and composition of the bioactive glass powder were determined. Twenty flat dentin surfaces from sound extracted human molars were polished with 600-grit SiC paper and air-abraded using experimental bioactive glass niobium powder. The bonding procedures were accomplished by the application of two resin cements: self-etching Panavia F or self-adhesive RelyX U-100. The resin-bonded specimens were cut and the μTBS test was performed after 24h. The failure mode was determined with a stereomicroscope at 40× magnification. The results were statistically analyzed by two-way ANOVA and Tukey tests (α=0.05). The two-way ANOVA did not detect interactions between factors, but only a difference between the self-etching and self-adhesive cement (p=0.001). The self-etching resin cement Panavia F obtained a higher μTBS than the self-adhesive cement Relyx U-100. The predominant failure mode of the cements was adhesive/mixed between the resin cement and dentin. A new bioactive glass containing niobium did not interfere with the immediate bonding performance of self-etching and self-adhesive cements. Copyright © 2015 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  1. First experimental results of particle re-suspension in a low pressure wind tunnel applied to the issue of dust in fusion reactors

    Energy Technology Data Exchange (ETDEWEB)

    Rondeau, Anthony, E-mail: anthony.rondeau@irsn.fr [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SCA, Gif-sur-Yvette 91192 (France); Merrison, Jonathan; Iversen, Jens Jacob [Department of Physics and Astronomy, Institute for Storage Ring Facilities, 8000 Aarhus C (Denmark); Peillon, Samuel; Sabroux, Jean-Christophe; Lemaitre, Pascal; Gensdarmes, François [Institut de Radioprotection et de Sûreté Nucléaire (IRSN), PSN-RES/SCA, Gif-sur-Yvette 91192 (France); Chassefière, Eric [Laboratoire Géosciences Paris Sud (GEOPS), UMR 8148, Université Paris Sud, 91403 Orsay Cedex (France)

    2015-10-15

    Highlights: • The first experimental data of dust re-suspension performed by controlled airflow (in terms of airflow velocity and fluid density). • The effect of the surrounding pressure in the re-suspension mechanism. • The friction (shear velocity) reduction at low pressure in the transient regime (Knudsen number close to one). • The importance of the adhesion forces between particles in dust mobilization by clustering. • The fact that the existing re-suspension models of the relevant literature do not take into account this clustering phenomenon. - Abstract: During the normal operating condition of the future ITER tokamak, a massive production of dust in the toroidal vacuum vessel is expected. This dust, originating from the erosion of tungsten and beryllium internal walls of the torus by the plasma, would be mobilized to some extent during a loss of vacuum accident (LOVA). For safety reasons, it is essential to quantify the re-suspended dust fraction during such an event. Here, we provide preliminary experimental data of dust re-suspension obtained in the wind tunnel of the European Space Agency (ESA) at low pressures (300, 130 and 10 mbar). The experimentations were performed with multilayer deposits. We used two powders with a median diameter at 15.5 μm and 21.8 μm. A negative influence of the low pressure in the re-suspension mechanism is observed. For example, given a re-suspension fraction of 10%, increasing friction shear velocities are derived for decreasing absolute pressures: 300 mbar/0.66 m s{sup −1}; 130 mbar/1.08 m s{sup −1}; and 10 mbar/1.84 m s{sup −1}. In addition, we highlight the friction reduction for Kundsen numbers greater than 0.1 by an analysis of the airflow forces.

  2. Particle adhesion and removal

    CERN Document Server

    Mittal, K L

    2015-01-01

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

  3. Introduction to the Quantum Theory of Elementary Cycles

    Science.gov (United States)

    Dolce, Donatello

    Elementary Cycles Theory (ECT) is a novel exact formulation of quantum-relativistic mechanics. Here, we present an introduction to its basic quantum aspects. On the one hand, Newton's law of inertia states that every isolated particle has persistent motion, i.e. constant energy and momentum. On the other hand, undulatory mechanics associates, by means of the Planck constant, a recurrence in time and space to the energy and the momentum of an elementary particle, respectively. Paraphrasing these two fundamental principles of modern physics, ECT postulates that every elementary constituent of nature (every elementary particle) is characterized by persistent intrinsic periodicity (as long it does not interact) whose space-time duration determines its kinematical state (energy and momentum). In other words, undulatory mechanics is imposed as constraint "overdetermining" relativistic mechanics, with fundamental motivations on Einstein's proposal of unification of quantum and relativistic theories. Every free particle is a (de Broglie) "periodic phenomenon" which can also be regarded as a reference clock and every system is decomposable in modulated elementary cycles. Indeed, ECT introduces a cyclic nature to the ordinary relativistic space-time coordinates. The resulting classical-relativistic mechanics turns out to be fully consistent with relativity and, at the same time, reproduces exactly all the fundamental aspects of ordinary quantum-relativistic mechanics (without any explicit quantisation). Relativity only fixes the differential structure of space-time without giving any prescription about the boundary of space-time, and the constraint of covariant periodicity (or similar relativistic boundary conditions) is allowed by the variational principle for relativistic theories. The constraint of intrinsic periodicity enforces the local nature of relativistic space-time and the wave-particle duality. Besides such unified description of relativistic and quantum dynamics

  4. Scintillation Detectors for Charged Particles and Photons

    CERN Document Server

    Lecoq, P

    2011-01-01

    Scintillation Detectors for Charged Particles and Photons in 'Charged Particle Detectors - Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Subsection '3.1.1 Scintillation Detectors for Charged Particles and Photons' of Section '3.1 Charged Particle Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.1.1 Scintillation Detectors for Charged Particles and Photons 3.1.1.1 Basic detector principles and scintillator requirements 3.1.1.1.1 Interaction of ionizing radiation with scintillator material 3.1.1.1.2 Important scint...

  5. And then there were particles

    CERN Multimedia

    Landua, Rolf

    2007-01-01

    "The appearance of particles dates back to a period physicists find embarrassing, one when the amount of energy active in the Universe was so enormous that they simply cannot descrit it. It is, however, possible to imagine the birth of the elementary building blocks that make up matter and energy."(1 page)

  6. Search for massive supersymmetric particles decaying to many jets using the ATLAS detector in pp collisions at √s = 8 TeV

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

    2015-01-01

    Roč. 91, č. 11 (2015), "112016-1"-"112016-37" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * CERN LHC Coll * supersymmetry * background * topological * sparticle * cascade decay * experimental results * 8000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  7. Multiscale Experimental and Numerical Approach to the Powder Particle Shape Effect on Al-Al2O3 Coating Build-Up

    Science.gov (United States)

    Leger, P. E.; Sennour, M.; Delloro, F.; Borit, F.; Debray, A.; Gaslain, F.; Jeandin, M.; Ducos, M.

    2017-10-01

    Aluminum (Al) powders with spherical and irregular particle shapes were mixed with two alumina (Al2O3) powders with either a spherical or an angular particle shape to achieve high-performance cold-sprayed coatings onto steel. Two effects of the aluminum particle shape were observed. First, coating microstructure observation showed impinging heterogeneity depending on particle shape. Second, particle jet differences depending on particle morphology were shown by velocity maps. From the latter, SEM and XRD, three effects of the alumina particle shape were also shown, i.e., higher in-flight velocity of angular particles, fragmentation of spherical hollow particles and embedding of alumina particles with aluminum. Numerical simulation of particle impacts was developed to study the densification of Al coating due to Al2O3 addition through elucidation of Al-Al2O3 interaction behavior at the scale of the coating. Al/Al and Al/Al2O3 interfaces were investigated using TEM to understand coating strengthening effects due to alumina addition at the scale of the particle. As a whole, Al and Al2O3 particle shape effects were claimed to explain coating mechanical properties, e.g., microhardness and coating-substrate bond strength. This study resulted in specifying criteria to help cold spray users in selecting powders for their applications, to meet economic and technical requirements.

  8. Catalyst nano-particle size dependence of the Fischer-Tropsch reaction.

    Science.gov (United States)

    van Santen, Rutger A; Markvoor, Albert J

    2013-01-01

    Computational catalytic studies indicate that the elementary reactions that constitute the Fischer-Tropsch reaction strongly dependent on the structure of the catalyst reaction center. Recent experimental evidence is available that, for metallic Fischer-Tropsch catalysts such as Co or Ru, the very small metallic particles show altered catalytic performance. To distinguish between changes in the relative concentration of reaction centres, changes in chemical reactivity, or rate controlling steps, transient SSITKA data are extremely useful. Here, we present kinetics simulations to extract molecular kinetic information from SSITKA data. We have applied such simulations to interpret published experimental SSITKA data on nano-particle size dependent Fischer-Tropsch (FT) kinetics. The FT catalytic cycle consists of four essential reaction steps. Their relative size determines activity as well as selectivity. The simulated SSITKA indicate three different regimes with different kinetic behaviour, where the two fundamental regimes to distinguish are the monomer-formation-limited and the chain-growth-limited regime. Particle size changes shift kinetics from one to the other regime. We note different effects of supports and choice of metal composition on changes in elementary rates or the relative number of reactive centres when the particle size is decreased in the nanometre regime.

  9. Big research in new dimensions. Thinkers of our time about the actual elementary-particle physics at CERN; Grossforschung in neuen Dimensionen. Denker unserer Zeit ueber die aktuelle Elementarteilchenphysik am CERN

    Energy Technology Data Exchange (ETDEWEB)

    Kommer, Christoph (ed.) [Heidelberg Univ. (Germany); DKFZ, Heidelberg (Germany); Satz, Helmut [Bielefeld Univ. (Germany). Fakultaet fuer Physik; Blanchard, Philippe [Bielefeld Univ. (Germany). Abt. Theoretische Physik

    2016-07-01

    The following topics are dealt with: Research from the highest energies to the smallest particles at CERN, the laborious way to the Large Hadronic Collider, CERN as accelerator of techniques, culture, and society, a philosophical and sociological perspective of questions concerning CERN, quark matter research at CERN, the FAIR facility for antiproton and ion research. (HSI)

  10. Particle physics after the Higgs discovery: Philosophical perspectives

    Science.gov (United States)

    Friederich, Simon; Lehmkuhl, Dennis

    2015-08-01

    The recent discovery at the LHC of a particle with properties matching those expected of the Higgs boson is a decisive event in the history of particle physics. The present special section combines three contributions that approach conceptual and methodological challenges related to this event and the current situation in particle physics from different angles. One contribution studies the experimental practices of contemporary particle physics by investigating the role of computer simulations in these practices; in particular, it focuses on the status of simulations as compared to experiments that in some circumstances have analogous functions. One contribution investigates the status of the controversial naturalness problem that many physicists see as the most severe shortcoming of the Standard Model of elementary particle physics. Finally, a third contribution critically assesses the impact of suggested no-go theorems concerning the interpretability of rigorous algebraic quantum field theory in terms of particles at the phenomenological level. In what follows we present a short overview of these contributions, highlighting some of their central ideas and arguments and putting them into context.

  11. Experimental Entanglement of Four Particles

    Science.gov (United States)

    2016-09-22

    electrons and protons with quantum Monte Carlo methods; their simulations were, however, performed with trial wavefunctions based on the fixed static...type first- principles simulations. The basic formalism was first presented by Marx and Parrinello12. Recently this scheme was further developed by the

  12. Standard Model Particles from Split Octonions

    Directory of Open Access Journals (Sweden)

    Gogberashvili M.

    2016-01-01

    Full Text Available We model physical signals using elements of the algebra of split octonions over the field of real numbers. Elementary particles are corresponded to the special elements of the algebra that nullify octonionic norms (zero divisors. It is shown that the standard model particle spectrum naturally follows from the classification of the independent primitive zero divisors of split octonions.

  13. Gas-solid turbulent flow in a circulating fluidized bed riser: experimental and numerical study of mono-disperse particle systems

    NARCIS (Netherlands)

    He, Y.; Deen, N.G.; van Sint Annaland, M.; Kuipers, J.A.M.

    2009-01-01

    Numerical simulations were performed of a turbulent gas-particle multiphase flow in a circulating fluidized bed riser using a hard-sphere discrete particle model (DPM) for the particle phase and the Navier−Stokes equations for the gas phase, where the subgrid scale stresses (SGS) were modeled with

  14. Making ATLAS Data from CERN Accessible to the General Public: The Development and Evaluation of a Learning Resource in Experimental Particle Physics

    CERN Document Server

    AUTHOR|(CDS)2243922; Ekelin, Svea Magdalena; Lund-Jensen, Bengt; Christiansen, Iben

    2017-08-15

    In 2016, the ATLAS experiment at CERN released data from 100 trillion proton-proton collisions to the general public. In connection to this release the ATLAS Outreach group has developed several tools for visualizing and analyzing the data, one of which is a Histogram analyzer. The focus of this project is to bridge the gap between the general public's knowledge in physics and what is needed to use this Histogram analyzer. The project consists of both the development and an evaluation of a learning resource that explains experimental particle physics for a general public audience. The learning resource is a website making use of analogies and two perspectives on learning: Variation Theory and Cognitive Load Theory. The evaluation of the website was done using a survey with 10 respondents and it focused on whether analogies and the perspectives on learning helped their understanding. In general the respondents found the analogies to be helpful for their learning, and to some degree they found the explanations ...

  15. Can Eco-Schools Improve Elementary School Students' Environmental Literacy Levels?

    Science.gov (United States)

    Ozsoy, Sibel; Ertepinar, Hamide; Saglam, Necdet

    2012-01-01

    This study was conducted to investigate the effects of eco-schools on elementary school students' environmental literacy levels. Data of the study were gathered from 316 students enrolled to two elementary schools. One of the schools was determined as experimental group (n = 156) and students attending this school received eco-school application.…

  16. The Effects of a Special School Library Program on Elementary Students' Library Use and Attitudes.

    Science.gov (United States)

    Schon, Isabel; And Others

    A group of 40 elementary school librarians in the greater Phoenix area of Arizona were invited to participate in a study of the effects of an experimental school library motivational program on library use, library attitudes, and reading attitudes of elementary school students. Librarians at 13 schools participated, with 11 completing the study.…

  17. A Toy Clinic Shop: Innovation Management in a Shin-Tai Elementary School

    Science.gov (United States)

    Hong, Jon-Chao; Hwang, Ming-Yueh; Liang, Hwey-Wen; Chang, Hsin-Wu

    2008-01-01

    In Taiwan there is a declining birth rate and a dramatic increase in the elderly population. There is also the trend of using school space that would otherwise be left unused. The experimental project "Toy Clinic Shop in Elementary School" offers an innovative management model for elementary schools to address these developments. The…

  18. Media Presentations on the Reading Attention and Comprehension of Taiwanese Elementary School Students

    Science.gov (United States)

    Ku, David Tawei; Cheng, Yu-Mei

    2016-01-01

    We adopted an experimental design to investigate the effects of various media presentation modes on the reading attention and comprehension of Taiwanese elementary school students. The participants comprised 138 students from 4 classes of third grade elementary school students from New Taipei City, Taiwan. The participants attended 5 short stories…

  19. Elementary heat transfer analysis

    CERN Document Server

    Whitaker, Stephen; Hartnett, James P

    1976-01-01

    Elementary Heat Transfer Analysis provides information pertinent to the fundamental aspects of the nature of transient heat conduction. This book presents a thorough understanding of the thermal energy equation and its application to boundary layer flows and confined and unconfined turbulent flows. Organized into nine chapters, this book begins with an overview of the use of heat transfer coefficients in formulating the flux condition at phase interface. This text then explains the specification as well as application of flux boundary conditions. Other chapters consider a derivation of the tra

  20. Elementary Statistics Tables

    CERN Document Server

    Neave, Henry R

    2012-01-01

    This book, designed for students taking a basic introductory course in statistical analysis, is far more than just a book of tables. Each table is accompanied by a careful but concise explanation and useful worked examples. Requiring little mathematical background, Elementary Statistics Tables is thus not just a reference book but a positive and user-friendly teaching and learning aid. The new edition contains a new and comprehensive "teach-yourself" section on a simple but powerful approach, now well-known in parts of industry but less so in academia, to analysing and interpreting process dat

  1. Elementary matrix theory

    CERN Document Server

    Eves, Howard

    1980-01-01

    The usefulness of matrix theory as a tool in disciplines ranging from quantum mechanics to psychometrics is widely recognized, and courses in matrix theory are increasingly a standard part of the undergraduate curriculum.This outstanding text offers an unusual introduction to matrix theory at the undergraduate level. Unlike most texts dealing with the topic, which tend to remain on an abstract level, Dr. Eves' book employs a concrete elementary approach, avoiding abstraction until the final chapter. This practical method renders the text especially accessible to students of physics, engineeri

  2. Particles and quantum fields

    CERN Document Server

    Kleinert, Hagen

    2016-01-01

    This is an introductory book on elementary particles and their interactions. It starts out with many-body Schrödinger theory and second quantization and leads, via its generalization, to relativistic fields of various spins and to gravity. The text begins with the best known quantum field theory so far, the quantum electrodynamics of photon and electrons (QED). It continues by developing the theory of strong interactions between the elementary constituents of matter (quarks). This is possible due to the property called asymptotic freedom. On the way one has to tackle the problem of removing various infinities by renormalization. The divergent sums of infinitely many diagrams are performed with the renormalization group or by variational perturbation theory (VPT). The latter is an outcome of the Feynman-Kleinert variational approach to path integrals discussed in two earlier books of the author, one representing a comprehensive treatise on path integrals, the other dealing with critial phenomena. Unlike ordin...

  3. Particle Pollution

    Science.gov (United States)

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

  4. Elementary School Philosophy: A Response

    Science.gov (United States)

    Wartenberg, Thomas E.

    2012-01-01

    This article is a response to criticism of my book "Big Ideas for Little Kids." The main topics addressed are: Who is the audience for the book? Can people without formal philosophical training can be good facilitators of elementary school philosophy discussions? Is it important to assess attempts to teach philosophy in elementary school? Should…

  5. Explorations in Elementary Mathematical Modeling

    Science.gov (United States)

    Shahin, Mazen

    2010-01-01

    In this paper we will present the methodology and pedagogy of Elementary Mathematical Modeling as a one-semester course in the liberal arts core. We will focus on the elementary models in finance and business. The main mathematical tools in this course are the difference equations and matrix algebra. We also integrate computer technology and…

  6. Some Results for Elementary Operations

    Science.gov (United States)

    Tsakalidis, Athanasios K.

    We present a number of results for elementary operations concerning the areas of data structures, computational geometry, graph algorithms and string algorithms. Especially, we focus on elementary operations like the dictionary operations, list manipulation, priority queues, temporal precedence, finger search, nearest common ancestors, negative cycle, 3-sided queries, rectangle enclosure, dominance searching, intersection queries, hidden line elimination and string manipulation.

  7. Particle swarm optimization with composite particles in dynamic environments.

    Science.gov (United States)

    Liu, Lili; Yang, Shengxiang; Wang, Dingwei

    2010-12-01

    In recent years, there has been a growing interest in the study of particle swarm optimization (PSO) in dynamic environments. This paper presents a new PSO model, called PSO with composite particles (PSO-CP), to address dynamic optimization problems. PSO-CP partitions the swarm into a set of composite particles based on their similarity using a "worst first" principle. Inspired by the composite particle phenomenon in physics, the elementary members in each composite particle interact via a velocity-anisotropic reflection scheme to integrate valuable information for effectively and rapidly finding the promising optima in the search space. Each composite particle maintains the diversity by a scattering operator. In addition, an integral movement strategy is introduced to promote the swarm diversity. Experiments on a typical dynamic test benchmark problem provide a guideline for setting the involved parameters and show that PSO-CP is efficient in comparison with several state-of-the-art PSO algorithms for dynamic optimization problems.

  8. Elementary chaotic snap flows

    Energy Technology Data Exchange (ETDEWEB)

    Munmuangsaen, Buncha [Sirindhorn International Institute of Technology (SIIT), Thammasat University, 131 M5, Tivanont Road, Bangkadi, Muang, Pathum-Thani 12000 (Thailand); Srisuchinwong, Banlue, E-mail: banlue@siit.tu.ac.th [Sirindhorn International Institute of Technology (SIIT), Thammasat University, 131 M5, Tivanont Road, Bangkadi, Muang, Pathum-Thani 12000 (Thailand)

    2011-11-15

    Highlights: > Five new elementary chaotic snap flows and a generalization of an existing chaotic snap flow have been presented. > Three of all are conservative systems whilst three others are dissipative systems. > Four cases need only a single control parameter and a single nonlinearity. > A cubic case in a jerk representation requires only two terms and a single nonlinearity. - Abstract: Hyperjerk systems with 4th-order derivative of the form x{sup ....}=f(x{sup ...},x{sup ..},x{sup .},x) have been referred to as snap systems. Five new elementary chaotic snap flows and a generalization of an existing flow are presented through an extensive numerical search. Four of these flows demonstrate elegant simplicity of a single control parameter based on a single nonlinearity of a quadratic, a piecewise-linear or an exponential type. Two others demonstrate elegant simplicity of all unity-in-magnitude parameters based on either a single cubic nonlinearity or three cubic nonlinearities. The chaotic snap flow with a single cubic nonlinearity requires only two terms and can be transformed to its equivalent dynamical form of only five terms which have a single nonlinearity. An advantage is that such a chaotic flow offers only five terms even though the (four) dimension is high. Three of the chaotic snap flows are characterized as conservative systems whilst three others are dissipative systems. Basic dynamical properties are described.

  9. Particle accelerator physics

    CERN Document Server

    Wiedemann, Helmut

    2015-01-01

    This book by Helmut Wiedemann is a well-established, classic text, providing an in-depth and comprehensive introduction to the field of high-energy particle acceleration and beam dynamics. The present 4th edition has been significantly revised, updated and expanded. The newly conceived Part I is an elementary introduction to the subject matter for undergraduate students. Part II gathers the basic tools in preparation of a more advanced treatment, summarizing the essentials of electrostatics and electrodynamics as well as of particle dynamics in electromagnetic fields. Part III is an extensive primer in beam dynamics, followed, in Part IV, by an introduction and description of the main beam parameters and including a new chapter on beam emittance and lattice design. Part V is devoted to the treatment of perturbations in beam dynamics. Part VI then discusses the details of charged particle acceleration. Parts VII and VIII introduce the more advanced topics of coupled beam dynamics and describe very intense bea...

  10. Introduction to Particle Physics course

    CERN Multimedia

    CERN. Geneva HR-RFA

    2006-01-01

    These lectures are an introduction to the ideas of particle physics, aimed at students and teachers with little or on knowledge of the subject. They form a broad basis that will be developed in more detail by the subsequent lecturers in the school. These four lectures are meant to present an overview of particle physics based on its historical evolution over the past century. It will be shown how concepts have evolved following progress in instrumentation and in theoretical ideas, from atoms to the elementary particles and their interactions, as they are known today.

  11. Obituaries: Oreste Piccioni, 86, a leader in particle physics field

    CERN Multimedia

    2002-01-01

    Oreste Piccioni, a leading scientist in the field of elementary particle physics and emeritus professor at the University of California, San Diego, USA, has died of complications from diabetes and lung cancer. He was 86 (1 page).

  12. Unitarity methods and on-shell particles in scattering amplitudes

    NARCIS (Netherlands)

    Rietkerk, R.J.

    2016-01-01

    The Standard Model of particle physics describes all known elementary particles and their interactions. Important tests of this theory are performed with high-energy particle scattering experiments, for instance at the Large Hadron Collider. Such scattering processes are impressively well described

  13. A novel experimental approach for the determination of the photooxidative decay of semivolatile pesticides and POPs adsorbed on single levitated particles; Aufbau eines Messverfahrens zum photo-oxidativen Abbau von semivolatilen Pflanzenschutzmitteln und POPs an levitierten Einzelpartikeln

    Energy Technology Data Exchange (ETDEWEB)

    Ruehl, E.

    2002-08-01

    A novel experimental approach has been developed that permits to measure in the laboratory the atmospheric decay of low volatile, particle-bound compounds (pesticides, persistent organic pollutants (POP)) which react efficiently with OH-radicals in the atmosphere. The experimental approach makes use of trapped micro- and nanoparticles which are coated by monolayers of the low volatile compounds. Trapping is accomplished by storing the particles in an electrodynamic trap, which is surrounded by a controlled atmosphere. The temperature, pressure, humidity, and the chemical composition of the atmosphere can be adjusted to the atmospheric environment of interest. The particles can be exposed to reactive trace gases, such as OH radicals or ozone. The chemically induced changes of the adsorbates are time-resolved monitored by Raman spectroscopy. As a result, chemical processes, reaction products, as well as evaporation from the particle surface can be investigated. Alternatively, Fourier-transform infrared spectroscopy can be used for the detection of such time resolved processes. The experiments allow us to derive kinetic data of particle-bound low volatile compounds. We have constructed and characterized all devices and components that are required for this novel experimental approach. This included a suitable particle trap, sources of OH radicals, and the efficient detection of time-resolved Raman spectra of stored particles. The components were commissioned by using simple, but realistic test systems. Raman spectra of particle-bound pesticides were measured and first kinetic experiments were performed. The setup is now ready to use for systems of environmental interest. (orig.) [German] Es wurde ein neues experimentelles Verfahren zur quantitativen Bestimmung des Abbaus von partikelgebundenen gering volatilen Substanzen (Pflanzenschutzmittel, persistente organische Schadstoffe (POP)) durch OH-Radikale aufgebaut. Der experimentelle Ansatz nutzt beruehrungslos

  14. Elementary polarization properties in the backscattering configuration.

    Science.gov (United States)

    Arteaga, Oriol; Garcia-Caurel, Enric; Ossikovski, Razvigor

    2014-10-15

    In the normal incidence backscattering configuration, a polarimetric measurement always preserves the reciprocal symmetry. For a reciprocal Jones matrix, the number of elementary polarization properties is reduced from six to four. In this work, the physical interpretation of these properties is examined and they are compared with the equivalent polarization properties in transmission. It is found that, with the exception of natural optical activity, a polarimetric backreflection experiment can essentially provide the same type of information about the anisotropy of a medium as a transmission analysis, although transmission and backreflection information comes in a completely different form. Experimental examples are provided to illustrate the discussion.

  15. Reach for Reference: Elementary-Middle School Science Reference Collections

    Science.gov (United States)

    Safford, Barbara Ripp

    2005-01-01

    This article presents a brief review of some new school science reference works. Two of the sources are traditional, while one is considered experimental. The two traditional reference works reviewed are "The American Heritage Children's Science Dictionary" for upper elementary grades, and "The American Heritage Student Science Dictionary" for…

  16. Self-diffusion of colloidal particles in a two-dimensional suspension: Are deviations from Fick’s law experimentally observable?

    NARCIS (Netherlands)

    Hoef, M.A. van der; Frenkel, D.; Ladd, A.J.C.

    1991-01-01

    Simulations of a colloidal particle suspended in a two-dimensional fluid are reported. The dissipative and fluctuating hydrodynamic forces acting on the particle are modeled by a lattice gas. Our results indicate that large long-time tails are present in both the translational and the rotational

  17. Elementary excitations of ferromagnetic metal nanoparticles

    Science.gov (United States)

    Cehovin, A.; Canali, C.; MacDonald, A.

    2003-07-01

    We present a theory of the elementary spin excitations in transition-metal ferromagnet nanoparticles which achieves a unified and consistent quantum description of both collective and quasiparticle physics. The theory starts by recognizing the essential role played by spin-orbit interactions in determining the energies of ferromagnetic resonances in the collective excitation spectrum and the strength of their coupling to low-energy particle-hole excitations. We argue that a crossover between Landau-damped ferromagnetic resonance and pure-state collective magnetic excitations occurs as the number of atoms in typical transition-metal ferromagnet nanoparticles drops below approximately 104, about where the single-particle level spacing, δ, becomes larger than (α)Eres, where Eres is the ferromagnetic resonance frequency and α is the Gilbert damping parameter. We illustrate our ideas by studying the properties of semirealistic model Hamiltonians, which we solve numerically for nanoparticles containing several hundred atoms. For small nanoparticles, we find one isolated ferromagnetic resonance collective mode below the lowest particle-hole excitation energy, at Eres≈0.1 meV. The spectral weight of this pure excitation nearly exhausts the transverse dynamical susceptibility spectral weight. As δ approaches (α)Eres, the ferromagnetic collective excitation is more likely to couple strongly with discrete particle-hole excitations. In this regime the distinction between the two types of excitations blurs. We discuss the significance of this picture for the interpretation of recent single-electron tunneling experiments.

  18. Duality and 'particle' democracy

    Science.gov (United States)

    Castellani, Elena

    2017-08-01

    Weak/strong duality is usually accompanied by what seems a puzzling ontological feature: the fact that under this kind of duality what is viewed as 'elementary' in one description gets mapped to what is viewed as 'composite' in the dual description. This paper investigates the meaning of this apparent 'particle democracy', as it has been called, by adopting an historical approach. The aim is to clarify the nature of the correspondence between 'dual particles' in the light of a historical analysis of the developments of the idea of weak/strong duality, starting with Dirac's electric-magnetic duality and its successive generalizations in the context of (Abelian and non-Abelian) field theory, to arrive at its first extension to string theory. This analysis is then used as evidential basis for discussing the 'elementary/composite' divide and, after taking another historical detour by analyzing an instructive analogy case (DHS duality and related nuclear democracy), drawing some conclusions on the particle-democracy issue.

  19. Search for massive, long-lived particles using multitrack displaced vertices or displaced lepton pairs in pp collisions at √s = 8 TeV with the ATLAS detector

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

    2015-01-01

    Roč. 92, č. 3 (2015), "072004-1"-"072004-37" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * CERN LHC Coll * neutralino * lifetime * neutralino * mass * neutralino * decay * trigger * experimental results * 8000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  20. Search for long-lived, weakly interacting particles that decay to displaced hadronic jets in proton-proton collisions at √s = 8 TeV with the ATLAS detector

    Czech Academy of Sciences Publication Activity Database

    Aad, G.; Abbott, B.; Abdallah, J.; Chudoba, Jiří; Havránek, Miroslav; Hejbal, Jiří; Jakoubek, Tomáš; Kepka, Oldřich; Kupčo, Alexander; Kůs, Vlastimil; Lokajíček, Miloš; Lysák, Roman; Marčišovský, Michal; Mikeštíková, Marcela; Němeček, Stanislav; Šícho, Petr; Staroba, Pavel; Svatoš, Michal; Taševský, Marek; Vrba, Václav

    2015-01-01

    Roč. 92, č. 1 (2015), "012010-1"-"012010-28" ISSN 1550-7998 R&D Projects: GA MŠk(CZ) LG13009 Institutional support: RVO:68378271 Keywords : ATLAS * tracking detector * CERN LHC Coll * background * benchmark * cross section * upper limit * experimental results * 8000 GeV-cms Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 4.643, year: 2014

  1. Elementary differential geometry

    CERN Document Server

    Pressley, Andrew

    2001-01-01

    Curves and surfaces are objects that everyone can see, and many of the questions that can be asked about them are natural and easily understood Differential geometry is concerned with the precise mathematical formulation of some of these questions, and with trying to answer them using calculus techniques It is a subject that contains some of the most beautiful and profound results in mathematics yet many of these are accessible to higher-level undergraduates Elementary Differential Geometry presents the main results in the differential geometry of curves and surfaces while keeping the prerequisites to an absolute minimum Nothing more than first courses in linear algebra and multivariate calculus are required, and the most direct and straightforward approach is used at all times Numerous diagrams illustrate both the ideas in the text and the examples of curves and surfaces discussed there The book will provide an invaluable resource to all those taking a first course in differential geometry, for their lecture...

  2. An integrated experimental-modeling approach to study the acid leaching behavior of lead from sub-micrometer lead silicate glass particles

    Energy Technology Data Exchange (ETDEWEB)

    Elteren, Johannes T. van, E-mail: elteren@ki.si [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Grilc, Miha [Laboratory of Catalysis and Chemical Reaction Engineering, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); Beeston, Michael P. [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia); TSI GmbH, Neuköllner Str. 4, 52068 Aachen (Germany); Reig, Milagros Santacatalina [General Foundation, University of Alicante, E-03690 San Vicente del Raspeig (Alicante) (Spain); Department of Chemical Engineering, University of Alicante, P.O. Box 99, E-03080 Alicante (Spain); Grgić, Irena [Analytical Chemistry Laboratory, National Institute of Chemistry, Hajdrihova 19, SI-1000 Ljubljana (Slovenia)

    2013-11-15

    Highlights: • Generation of particles by laser ablation of lead silicate glass. • Collection of particles on filters and continuous acid leaching and ICP-MS monitoring. • Fitting of the lead leaching profile to a mathematical intraparticle diffusion model. • Extraction of individual leaching profiles for selected mono-dispersed size fractions. • Leaching kinetics is based on ion-exchange and correlated with particle size. -- Abstract: This work focuses on the development of a procedure to study the mechanism of leaching of lead from sub-micrometer lead glass particles using 0.3 mol l{sup −1} HNO{sub 3} as a leachant. Glass particles with an effective size distribution range from 0.05 to 1.4 μm were generated by laser ablation (213 nm Nd:YAG laser) and collected on an inline 0.2 μm syringe filter. Subsequently, the glass particles on the filter were subjected to online leaching and continuous monitoring of lead (Pb-208) in the leachate by quadrupole ICP-MS. The lead leaching profile, aided by the particle size distribution information from cascade impaction, was numerically fitted to a mathematical model based on the glass intraparticle diffusion, liquid film distribution and thermodynamic glass-leachant distribution equilibrium. The findings of the modeling show that the rate-limiting step of leaching is the migration of lead from the core to the surface of the glass particle by an ion-exchange mechanism, governed by the apparent intraparticle lead diffusivity in glass which was calculated to be 3.1 × 10{sup −18} m{sup 2} s{sup −1}. Lead leaching is illustrated in the form of graphs and animations of intraparticle lead release (in time and intraparticle position) from particles with sizes of 0.1 and 0.3 μm.

  3. Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors - Particle Detectors and Detector Systems

    CERN Document Server

    Ullaland, O

    2011-01-01

    Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors in 'Particle Detectors and Detector Systems', part of 'Landolt-Börnstein - Group I Elementary Particles, Nuclei and Atoms: Numerical Data and Functional Relationships in Science and Technology, Volume 21B1: Detectors for Particles and Radiation. Part 1: Principles and Methods'. This document is part of Part 1 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors' of Chapter '3 Particle Detectors and Detector Systems' with the content: 3.3 Particle Identification: Time-of-Flight, Cherenkov and Transition Radiation Detectors 3.3.1 Introduction 3.3.2 Time of Flight Measurements 3.3.2.1 Scintillator hodoscopes 3.3.2.2 Parallel plate ToF detectors 3.3.3 Cherenkov Radiation 3.3.3.1 ...

  4. Elementary number theory with programming

    CERN Document Server

    Lewinter, Marty

    2015-01-01

    A successful presentation of the fundamental concepts of number theory and computer programming Bridging an existing gap between mathematics and programming, Elementary Number Theory with Programming provides a unique introduction to elementary number theory with fundamental coverage of computer programming. Written by highly-qualified experts in the fields of computer science and mathematics, the book features accessible coverage for readers with various levels of experience and explores number theory in the context of programming without relying on advanced prerequisite knowledge and con

  5. RESEARCH IN PARTICLE PHYSICS

    Energy Technology Data Exchange (ETDEWEB)

    Kearns, Edward [Boston Universiy

    2013-07-12

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

  6. The methodological problems of particle physics

    Energy Technology Data Exchange (ETDEWEB)

    Unzicker, Alexander [Pestalozzi-Gymnasium Muenchen (Germany)

    2013-07-01

    While the so-called standard model has been the dominating paradigm in particle physics for almost half a century, most researchers working with it would admit that it is an incomplete theory at best. Despite some ordering schemes, the overall number of its free parameters has greatly increased over the years, often accompanied by ad-hoc hypotheses such as 'confinement'. Experimentally, the interpretation of today's collider experiments requires sophisticated modeling of huge backgrounds. Specific problems are here how to remove correctly radiation damping (given that no consistent theory of electrodynamics exists), and postulating lifetimes (top quark) during which the particle cannot even leave the collision region. The standard model is about to develop new concepts, such as additional neutrino flavors and oscillations, while disregarding elementary questions such as to the nature of mass. From a historical perspective, the growing complications are likely to be symptoms of a scientific crisis, a phenomenon which has been described by the philosopher Thomas Kuhn. According to Kuhn however, there is no smooth transition from one paradigm to another. The only reasonable way to go beyond the standard model would be to abandon it completely.

  7. Experimental investigations on the coolability of prototypical particle beds with respect to reactor safety; Experimentelle Untersuchungen der Kuehlbarkeit prototypischer Schuettungskonfigurationen unter dem Aspekt der Reaktorsicherheit

    Energy Technology Data Exchange (ETDEWEB)

    Leininger, Simon

    2017-02-22

    In case of a severe accident in a light water reactor, continuous unavailability of cooling water to the reactor core may result in overheating of the fuel elements and finally the loss of core integrity. Under such conditions, a structure of heat-releasing particles of different size and shape may be formed by fragmentation of molten core material in several stages of the accident. The long-term coolability of such beds is of prime im-portance to avoid any damage to the reactor pressure vessel or even a release of fission products to the environment. In the frame of this work, specific experiments were con-ducted under prototypical conditions employing the existing DEBRIS test facility in order to gain further knowledge about the thermohydraulic behavior of such beds. In steady state boiling experiments, the pressure gradients in particle beds were meas-ured both for one- and multi-dimensional cooling water flow conditions and compared with one another in order to assess the flow behavior inside the bed. For these different flow conditions as well as for stratified bed configurations, the maximum removable heat flux densities were determined in the dryout experiments. E. g., it was found that an axial stratification of the permeability can significantly reduce the bed's coolability. For the first time, the quenching behavior of dry, superheated beds was investigated at elevated system pressure up to 0.5 MPa. In these experiments, the effect of system pressure on the coolability was quantified by means of the quenching time (time period to cool down the bed to saturation temperature). The investigated particle beds mainly consisted of non-spherical particles with well-defined geometry (cylinders and screws). It was shown that the effect of the particles geometry on the flow in a particle bed can be best estimated by using an equivalent particle diameter calculated for monodisperse particle beds from the product of the Sauter diameter and a shape factor and for

  8. A distance correction method for improving the accuracy of particle coal online X-ray fluorescence analysis - Part 2: Method and experimental investigation

    Science.gov (United States)

    Zhang, Yan; Jia, Wen Bao; Gardner, Robin; Shan, Qing; Zhang, Xin Lei; Hou, Guojing; Chang, Hao Ping

    2017-12-01

    The distance from X-Ray Fluorescence (XRF) spectrometer to sample surface always changes with the different coal's particle sizes, resulting in the inaccuracy of online XRF measurement. To improve the accuracy of particle coal online XRF analysis, a distance correction method was established elaborated by iteration, which was based on the relationship between the XRF intensity and the distance. In order to verify the effectiveness of this method, five different particle size coal samples with same components have been measured by the online XRF analyzer directly above the conveyor belt, in the meanwhile, the distances between XRF spectrometer and samples' surface were obtained by a laser rangefinder. The results showed that the average distances are decreased with decreasing the particle size. By comparing the results of before and after applying the distance correction method, we demonstrated that the measurement accuracy of online XRF analysis for particle coal can be significantly increased. The distance correction method can be used for the development of online XRF analysis techniques applicable for real-time industrial processes.

  9. Cosmology and particle physics

    Science.gov (United States)

    Turner, Michael S.

    1988-01-01

    The interplay between cosmology and elementary particle physics is discussed. The standard cosmology is reviewed, concentrating on primordial nucleosynthesis and discussing how the standard cosmology has been used to place constraints on the properties of various particles. Baryogenesis is discussed, showing how a scenario in which the B-, C-, and CP-violating interactions in GUTs provide a dynamical explanation for the predominance of matter over antimatter and for the present baryon-to-photon ratio. It is shown how the very early dynamical evolution of a very weakly coupled scalar field which is initially displaced from the minimum of its potential may explain a handful of very fundamental cosmological facts which are not explained by the standard cosmology.

  10. Experimental investigation of ice nucleation in water droplets and sulphate particles in the temperature range between -30 C and -65 C; Experimente zur Eisnukleation von Wassertroepfchen und Sulfatpartikeln bei Temperaturen zwischen -65 C und -30 C

    Energy Technology Data Exchange (ETDEWEB)

    Benz, S.

    2007-10-15

    High altitude cirrus clouds influence the climate by scattering and absorption of radiation. The cloud and aerosol chamber AIDA of Forschungszentrum Karlsruhe allows generation and observation of ice clouds in laboratory at realistic conditions. Experiments were carried out to investigate the ice formation in clouds of supercooled liquid water droplets and in sulphate aerosols. The homogeneous ice nucleation rate, given as the product of the number of critical ice germs to initiate the freezing and the rate at which additional molecules are incorporated into a critical germ, was measured at typical cloud conditions in the temperature range between -36 C and -37 C for supercooled water droplets with diameters smaller than 10 {mu}m. The comparison of the results shows good agreement both with recent data from literature gained from considerably larger droplets and with classical ice nucleation theory. Thereby, the hypothesis that a critical germ is formed preferentially near the surface of a supercooled droplet could not be confirmed. The ice formation from ammonium sulphate aerosol was examined in the temperature range from -50 C to -65 C. It was shown that ammonium sulphate solution particles, which were produced by neutralization of sulphuric acid solution particles by gaseous ammonia, freeze homogeneously at conditions comparable to sulphuric acid solution particles. If ammonium sulphate particles crystallize they start to form ice at comparatively low supersaturation values (10-20%) by direct deposition of water vapour onto the solid particles. Ammonia, which is highly anthropogenically affected, may influence the properties of upper tropospheric ice clouds. (orig.)

  11. Experimental investigations of the interaction of multi-GeV particles with strong crystalline fields and applications in high-energy beam lines

    CERN Document Server

    Mikkelsen, U

    1997-01-01

    The thesis first introduces the theory of the interaction of energetic particles with strong crystalline fields. It then treats a number of experiments that investigate different phenomena which can be divided in two: Strong field effects and bent crystals. Both of these include a wealth of sub-topics, such as pair production, strong gamma-ray emission, radiative cooling, polarized gamma-rays and possible inhibiting effects as well as an investigation of the advantage of high-Z materials for deflection of charged particles in crystals and an examination of the radiation hardness of the deflection phenomenon. A number of used and potential applications are considered.

  12. Plato's TIMAIOσ (TIMAEUS) and Modern Particle Physics

    Science.gov (United States)

    Machleidt, Ruprecht

    2005-04-01

    It is generally known that the question, ``What are the smallest particles (elementary particles) that all matter is made from?'', was posed already in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. It will be the purpose of my contribution to point out that this perception is wrong. Modern particle physics is not just a primitive atomism. More important than the materialistic particles are the underlying symmetries (e. g., SU(3) and SU(6)). A similar idea was first advanced by Plato in his dialog TIMAIOσ (Latin translation: TIMAEUS): Geometric symmetries generate the materialistic particles from a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle physics. This fact, which is unfortunately little known, has been pointed out repeatedly by Heisenberg (see, e. g., Werner Heisenberg, Across the Frontiers, Harper & Row, New York, 1974).

  13. Effect of high temperature annealing on the grain size of CVD-grown SiC and experimental PBMR TRISO coated particles

    CSIR Research Space (South Africa)

    Mokoduwe, SM

    2010-10-01

    Full Text Available -Isotropic (TRISO) Coated Particles (CPs) in a graphite matrix with the SiC layer being the main barrier to fission and transmutation products. The integrity of the CP three layer system namely, Inner Pyrolytic Carbon- Silicon carbide- Outer Pyrolytic Carbon (IPy...

  14. Experimental study of the effect of bubbles, drops and particles on the product distribution for a mixing sensitive, parallel-consecutive reaction system

    NARCIS (Netherlands)

    Brilman, Derk Willem Frederik; Antink, R.; van Swaaij, Willibrordus Petrus Maria; Versteeg, Geert

    1999-01-01

    For stirred multiphase reactors the effect of a dispersed (gas, liquid or solid) phase on the product distribution for a mixing sensitive reaction was tested. Turbulence modification due to the presence of dispersed-phase particles has been reported frequently in literature, but the extent of the

  15. The uses of isospin in early nuclear and particle physics

    Science.gov (United States)

    Borrelli, Arianna

    2017-11-01

    This paper reconstructs the early history of isospin up to and including its employment in 1951sbnd 52 to conceptualize high-energy pion-proton scattering. Studying the history of isospin serves as an entry point for investigating the interplay of theoretical and experimental practices in early nuclear and particle physics, showing the complexity of processes of knowledge construction which have often been presented as straightforward both in physicists' recollections and in the historiography of science. The story of isospin has often been told in terms of the discovery of the first ;intrinsic property; of elementary particles, but I will argue that the isospin formalism emerged and was further developed because it proved to be a useful tool to match theory and experiment within the steadily broadening field of high-energy (nuclear) physics. Isospin was variously appropriated and adapted in the course of two decades, before eventually the physical-mathematical implications of its uses started being spelled out. The case study also highlights some interesting features of high-energy physics around 1950: the contribution to post-war research of theoretical methods developed before and during the war, the role of young theoretical post-docs in mediating between theorists and experimenters, and the importance of traditional formalisms such as those of spin and angular momentum as a template both for formalizing and conceptualizing experimental results.

  16. Extraction of elementary rate constants from global network analysis of E. coli central metabolism

    Directory of Open Access Journals (Sweden)

    Broderick Gordon

    2008-05-01

    Full Text Available Abstract Background As computational performance steadily increases, so does interest in extending one-particle-per-molecule models to larger physiological problems. Such models however require elementary rate constants to calculate time-dependent rate coefficients under physiological conditions. Unfortunately, even when in vivo kinetic data is available, it is often in the form of aggregated rate laws (ARL that do not specify the required elementary rate constants corresponding to mass-action rate laws (MRL. There is therefore a need to develop a method which is capable of automatically transforming ARL kinetic information into more detailed MRL rate constants. Results By incorporating proteomic data related to enzyme abundance into an MRL modelling framework, here we present an efficient method operating at a global network level for extracting elementary rate constants from experiment-based aggregated rate law (ARL models. The method combines two techniques that can be used to overcome the difficult properties in parameterization. The first, a hybrid MRL/ARL modelling technique, is used to divide the parameter estimation problem into sub-problems, so that the parameters of the mass action rate laws for each enzyme are estimated in separate steps. This reduces the number of parameters that have to be optimized simultaneously. The second, a hybrid algebraic-numerical simulation and optimization approach, is used to render some rate constants identifiable, as well as to greatly narrow the bounds of the other rate constants that remain unidentifiable. This is done by incorporating equality constraints derived from the King-Altman and Cleland method into the simulated annealing algorithm. We apply these two techniques to estimate the rate constants of a model of E. coli glycolytic pathways. The simulation and statistical results show that our innovative method performs well in dealing with the issues of high computation cost, stiffness, local

  17. Polygamous particles

    OpenAIRE

    Wu, Kun-Ta; Feng, Lang; Sha, Ruojie; Dreyfus, Rémi; Grosberg, Alexander Y.; Seeman, Nadrian C.; Chaikin, Paul M.

    2012-01-01

    DNA is increasingly used as an important tool in programming the self-assembly of micrometer- and nanometer-scale particles. This is largely due to the highly specific thermoreversible interaction of cDNA strands, which, when placed on different particles, have been used to bind precise pairs in aggregates and crystals. However, DNA functionalized particles will only reach their true potential for particle assembly when each particle can address and bind to many different kinds of particles. ...

  18. Particle Physics: The mass of a top

    CERN Document Server

    Skands, Peter

    2014-01-01

    A measurement of the mass of the heftiest-known elementary particle, the top quark, which exists for less than a trillionth of a trillionth of a second, sheds light on the ultimate fate of our Universe, although ambiguities cloud its interpretation.

  19. Acoustics in the elementary classroom

    Science.gov (United States)

    Hansen, Uwe J.

    2005-04-01

    The need for increased science exposure at all educational levels continues to be acute. Science is almost universally perceived as difficult, and its ability to raise the quality of life in the presence of apparently insurmountable social problems is increasingly suspect. Over the past 15 years we have conducted teacher workshops, visited classrooms, have organized hands-on demonstration sessions, judged science fairs, and mentored high school students in research efforts, all in an attempt to raise the level of enthusiasm for science. A look ahead suggests that the need continues. Elementary school teachers all too often limit their own science skills to plants and animals, and thus physics concepts do not get the exposure needed to generate the necessary excitement for the physical sciences. Workshops for Elementary grade teachers will be described, which are aimed at preparing teachers to use music as a vehicle to introduce basic physics concepts in the upper elementary grades.

  20. Elementary functions algorithms and implementation

    CERN Document Server

    Muller, Jean-Michel

    2016-01-01

    This textbook presents the concepts and tools necessary to understand, build, and implement algorithms for computing elementary functions (e.g., logarithms, exponentials, and the trigonometric functions). Both hardware- and software-oriented algorithms are included, along with issues related to accurate floating-point implementation. This third edition has been updated and expanded to incorporate the most recent advances in the field, new elementary function algorithms, and function software. After a preliminary chapter that briefly introduces some fundamental concepts of computer arithmetic, such as floating-point arithmetic and redundant number systems, the text is divided into three main parts. Part I considers the computation of elementary functions using algorithms based on polynomial or rational approximations and using table-based methods; the final chapter in this section deals with basic principles of multiple-precision arithmetic. Part II is devoted to a presentation of “shift-and-add” algorithm...

  1. Elementary quantum mechanics

    CERN Document Server

    Saxon, David S

    2012-01-01

    Based on lectures for an undergraduate UCLA course in quantum mechanics, this volume focuses on the formulas of quantum mechanics rather than applications. Widely used in both upper-level undergraduate and graduate courses, it offers a broad self-contained survey rather than in-depth treatments.Topics include the dual nature of matter and radiation, state functions and their interpretation, linear momentum, the motion of a free particle, Schrödinger's equation, approximation methods, angular momentum, and many other subjects. In the interests of keeping the mathematics as simple as possible, m

  2. Testing Elementary Cycles Formulation of Quantum Mechanics in Carbon Nanotubes and Superconductivity

    CERN Document Server

    Dolce, Donatello

    2016-01-01

    Elementary Cycles are intrinsic periodic phenomena, classical in the essence, whose classical relativistic dynamics reproduce the complete coherence (perfect recurrences) typically associated to the pure quantum behaviours of elementary particles. They can be regarded as effective representations of 't Hooft Cellular Automata. By means of Elementary Cycles physics we obtain a consistent, intuitive, novel derivation of the peculiar quantum dynamics of electrons in Carbon Nanotubes, as well as of Superconductivity fundamental phenomenology. In particular we derive, from classical arguments, the essential electronic properties of graphene systems, such as energy bands and density of states. Similarly, in the second part of the paper, we derive the Superconductivity fundamental phenomenology in terms of simple geometrical considerations, directly from the Elementary Cycles dynamics rather than from empirical aspects and effective quantities connected to the microscopical characteristics of materials as in the sta...

  3. Experimental investigations of the interaction of multi-GeV particles with strong crystalline fields and applications in high-energy beam lines

    OpenAIRE

    Mikkelsen, U

    1997-01-01

    The thesis first introduces the theory of the interaction of energetic particles with strong crystalline fields. It then treats a number of experiments that investigate different phenomena which can be divided in two: Strong field effects and bent crystals. Both of these include a wealth of sub-topics, such as pair production, strong gamma-ray emission, radiative cooling, polarized gamma-rays and possible inhibiting effects as well as an investigation of the advantage of high-Z materials for ...

  4. Critique of Quantum Optical Experimental Refutations of Bohr's Principle of Complementarity, of the Wootters-Zurek Principle of Complementarity, and of the Particle-Wave Duality Relation

    OpenAIRE

    Kaloyerou, P. N.

    2014-01-01

    I argue that quantum optical experiments that purport to refute Bohr's principle of complementarity (BPC) fail in their aim. Some of these experiments try to refute complementarity by refuting the so called particle-wave duality relations, which evolved from the Wootters-Zureck reformulation of BPC (WZPC). I therefore consider it important for my forgoing arguments to first recall the essential tenets of BPC, and to clearly separate BPC from WZPC, which I will argue is a direct contradiction ...

  5. LHCb unveils new particles

    CERN Multimedia

    Stefania Pandolfi

    2016-01-01

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

  6. Quarks, Leptons, and Bosons: A Particle Physics Primer.

    Science.gov (United States)

    Wagoner, Robert; Goldsmith, Donald

    1983-01-01

    Presented is a non-technical introduction to particle physics. The material is adapted from chapter 3 of "Cosmic Horizons," (by Robert Wagoner and Don Goldsmith), a lay-person's introduction to cosmology. Among the topics considered are elementary particles, forces and motion, and higher level structures. (JN)

  7. Skinny W particle offers thinspiration for US physicists

    CERN Document Server

    Sherriff, Lucy

    2007-01-01

    "It seems even elementary particles resolve to lose weight in the new year. A new calculation of the mass of the W particle (instrumental in radioactive decay) suggests that it is lighter than scientists had thought up until now." (1 page)

  8. Correlation energy for elementary bosons: Physics of the singularity

    Energy Technology Data Exchange (ETDEWEB)

    Shiau, Shiue-Yuan, E-mail: syshiau@mail.ncku.edu.tw [Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan (China); Combescot, Monique [Institut des NanoSciences de Paris, Université Pierre et Marie Curie, CNRS, 4 place Jussieu, 75005 Paris (France); Chang, Yia-Chung, E-mail: yiachang@gate.sinica.edu.tw [Research Center for Applied Sciences, Academia Sinica, Taipei, 115, Taiwan (China); Department of Physics, National Cheng Kung University, Tainan, 701, Taiwan (China)

    2016-04-15

    We propose a compact perturbative approach that reveals the physical origin of the singularity occurring in the density dependence of correlation energy: like fermions, elementary bosons have a singular correlation energy which comes from the accumulation, through Feynman “bubble” diagrams, of the same non-zero momentum transfer excitations from the free particle ground state, that is, the Fermi sea for fermions and the Bose–Einstein condensate for bosons. This understanding paves the way toward deriving the correlation energy of composite bosons like atomic dimers and semiconductor excitons, by suggesting Shiva diagrams that have similarity with Feynman “bubble” diagrams, the previous elementary boson approaches, which hide this physics, being inappropriate to do so.

  9. Elementary particle physics. Progress report, July 1992--October 1994

    Energy Technology Data Exchange (ETDEWEB)

    Izen, J.M.

    1994-10-01

    The University of Texas at Dallas (UTD) is participating in two e{sup +}e{sup -}, experiments, Beijing Spectrometer (BES) and BABAR, the PEP-11 B Factory detector. The UTD group consists of Profs. Joseph M. Izen and Xinchou Lou, seven Ph.D. students. A post-doc is requested to join them in this work. BES explores the physics of the {tau}-charm threshold region. Associated production of {tau} and charmed mesons allow for absolute branching fraction measurements with good control of backgrounds. BES is uniquely positioned to study the leptonic and hadronic decays of quarkonia. The Beijing Electron Positron Collider (BEPC) delivers luminosities an order of magnitude higher than earlier facilities. BES and BEPC will be upgraded following the 1994-5 run, and will resume data taking in Fall, 1996 with an improved detector and a Three-fold increase in luminosity. The raison d`etre of BABAR is the exploration of CP violation in the B meson system. An asymmetric storage ring is required to observe the time-dependence of the CP asymmetry. Other BABAR physics includes measurements of CKM matrix elements, rare B decays, penguin diagrams, B{sub s} decays, and precision measurements of {tau} and D meson decays. The scheduled BABAR turn-on in 1999 provides the UTD group with a natural evolution with continuous physics during this period. Professors Joseph M. Izen and Xinchou Lou are leading the BES and BABAR program at UTD. Both have specialized in e{sup +}e{sup -} collider experiments and share 22 years of experience at the SPEAR, BEPC, CESR, PETRA, SLC and LEP rings.

  10. Introducing 12 year-olds to elementary particles

    Science.gov (United States)

    Wiener, Gerfried J.; Schmeling, Sascha M.; Hopf, Martin

    2017-07-01

    We present a new learning unit, which introduces 12 year-olds to the subatomic structure of matter. The learning unit was iteratively developed as a design-based research project using the technique of probing acceptance. We give a brief overview of the unit’s final version, discuss its key ideas and main concepts, and conclude by highlighting the main implications of our research, which we consider to be most promising for use in the physics classroom.

  11. Theoretical Advanced Study Institute in Elementary Particle Physics

    CERN Document Server

    2017-01-01

    The program will consist of a pedagogical series of lectures and seminars. Lectures will be given over a four-week period, three or four lectures per day, Monday through Friday. The audience will be composed primarily of advanced theoretical graduate students. Experimentalists with a strong background in theory are also encouraged to apply. Some post-doctoral fellows will be admitted, but preference will be given to applicants who will not have received their Ph.D. before 2017. The minimum background needed to get full benefit of TASI is a knowledge of quantum field theory (including RGEs) and familiarity with the Standard Model. Some familiarity with SUSY would be helpful. We hope to provide some subsidy, but students will need partial support from other sources. Rooms, meals, and access to all facilities will be provided at reasonable rates in beautifully located dormitories at the University of Colorado.

  12. Final Report for Studies in Elementary Particle Physics

    Energy Technology Data Exchange (ETDEWEB)

    Piilonen, Leo; Takeuchi, Tatsu; Minic, Djordje; Link, Jonathan

    2013-11-01

    This is the final report of DOE Grant DE-FG05-92ER40709 awarded to the Virginia Tech high energy physics group. It covers the period February 1, 2010 through April 30, 2013. The high energy physics program at Virginia Tech supported by this grant is organized into three tasks: A for theory (Profs. Tatsu Takeuchi and Djordje Minic), B for heavy flavor physics with the Belle and Belle II experiments (Prof. Leo Piilonen), and N for neutrino physics (Profs. Jonathan Link and Piilonen).

  13. Elementary Particle Physics Experiment at the University of Massachusetts, Amherst

    Energy Technology Data Exchange (ETDEWEB)

    Brau, Benjamin; Dallapiccola, Carlo; Willocq, Stephane

    2013-07-30

    In this progress report we summarize the activities of the University of Massachusetts- Amherst group for the three years of this research project. We are fully engaged in research at the energy frontier with the ATLAS experiment at the CERN Large Hadron Collider. We have made leading contributions in software development and performance studies for the ATLAS Muon Spectrometer, as well as on physics analysis with an emphasis on Standard Model measurements and searches for physics beyond the Standard Model. In addition, we have increased our contributions to the Muon Spectrometer New Small Wheel upgrade project.

  14. A non-perturbative mechanism for elementary particle mass generation

    CERN Document Server

    Frezzotti, R

    2014-01-01

    Taking inspiration from lattice QCD data, we argue that a finite non-perturbative mass contribution for quarks is generated as a consequence of the dynamical phenomenon of spontaneous chiral symmetry breaking, in turn triggered by the explicitly breaking of chiral symmetry induced by the critical Wilson term in the action. In pure lattice QCD this mass term cannot be separated from the unavoidably associated linearly divergent contribution. However, if QCD is enlarged to a theory where also a scalar field is present, coupled to a doublet of SU(2) fermions via a Yukawa and a Wilson-like term, then in the phase where the scalar field takes a non-vanishing expectation value, a dynamically generated and "naturally" light fermion mass (numerically unrelated to the expectation value of the scalar field) is conjectured to emerge at a critical value of the Yukawa coupling where the symmetry of the model is maximally enhanced. Masses dynamically generated in this way display a natural hierarchy according to which the ...

  15. On an elementary definition of visual saliency

    DEFF Research Database (Denmark)

    Loog, Marco

    2008-01-01

    Various approaches to computational modelling of bottom-up visual attention have been proposed in the past two decades. As part of this trend, researchers have studied ways to characterize the saliency map underlying many of these models. In more recent years, several definitions based...... on probabilistic and information or decision theoretic considerations have been proposed. These provide experimentally successful, appealing, low-level, operational, and elementary definitions of visual saliency (see eg, Bruce, 2005 Neurocomputing 65 125 - 133). Here, I demonstrate that, in fact, all...... these characterizations provide essentially the same measure of saliency. Moreover, where the original formulations rely on empirical estimates of the underlying probability density of low-level pre-attentive features, I show that saliency can be expressed as a closed-form solution based on purely local measurements and...

  16. Laboratory study on new particle formation from the reaction OH + SO2: influence of experimental conditions, H2O vapour, NH3 and the amine tert-butylamine on the overall process

    Directory of Open Access Journals (Sweden)

    J. Curtius

    2010-08-01

    Full Text Available Nucleation experiments starting from the reaction of OH radicals with SO2 have been performed in the IfT-LFT flow tube under atmospheric conditions at 293±0.5 K for a relative humidity of 13–61%. The presence of different additives (H2, CO, 1,3,5-trimethylbenzene for adjusting the OH radical concentration and resulting OH levels in the range (4–300 ×105 molecule cm−3 did not influence the nucleation process itself. The number of detected particles as well as the threshold H2SO4 concentration needed for nucleation was found to be strongly dependent on the counting efficiency of the used counting devices. High-sensitivity particle counters allowed the measurement of freshly nucleated particles with diameters down to about 1.5 nm. A parameterization of the experimental data was developed using power law equations for H2SO4 and H2O vapour. The exponent for H2SO4 from different measurement series was in the range of 1.7–2.1 being in good agreement with those arising from analysis of nucleation events in the atmosphere. For increasing relative humidity, an increase of the particle number was observed. The exponent for H2O vapour was found to be 3.1 representing an upper limit. Addition of 1.2×1011 molecule cm−3 or 1.2×1012 molecule cm−3 of NH3 (range of atmospheric NH3 peak concentrations revealed that NH3 has a measureable, promoting effect on the nucleation rate under these conditions. The promoting effect was found to be more pronounced for relatively dry conditions, i.e. a rise of the particle number by 1–2 orders of magnitude at RH = 13% and only by a factor of 2–5 at RH = 47% (NH3 addition: 1.2×1012 molecule cm−3. Using the amine tert-butylamine instead of NH3, the enhancing impact of the base for nucleation and particle growth appears to be stronger. Tert-butylamine addition of about 1010 molecule cm−3 at RH = 13% enhances particle formation by about two orders of magnitude, while for NH3 only a small or negligible

  17. Experimental study of the rearrangements of valence protons and neutrons amongst single-particle orbits during double-β decay in 100Mo

    Science.gov (United States)

    Freeman, S. J.; Sharp, D. K.; McAllister, S. A.; Kay, B. P.; Deibel, C. M.; Faestermann, T.; Hertenberger, R.; Mitchell, A. J.; Schiffer, J. P.; Szwec, S. V.; Thomas, J. S.; Wirth, H.-F.

    2017-11-01

    The rearrangements of protons and neutrons amongst the valence single-particle orbitals during double-β decay of 100Mo have been determined by measuring cross sections in (d ,p ), (p ,d ), (3He,α ), and (3He,d ) reactions on Mo,10098 and Ru,102100 targets. The deduced nucleon occupancies reveal significant discrepancies when compared with theoretical calculations; the same calculations have previously been used to determine the nuclear matrix element associated with the decay probability of double-β decay of the 100Mo system.

  18. Assessment in Elementary Dance Education

    Science.gov (United States)

    Englebright, Krissa; Mahoney, Meg Robson

    2012-01-01

    In this article, two public school elementary dance educators share their experiences developing and implementing dance performance assessments. The assessments were developed for the State of Washington Office of the Superintendent of Public Instruction to assess student learning in dance education and bring dance assessment to an equal platform…

  19. Thomas Edison Accelerated Elementary School.

    Science.gov (United States)

    Levin, Henry M.; Chasin, Gene

    This paper describes early outcomes of a Sacramento, California, elementary school that participated in the Accelerated Schools Project. The school, which serves many minority and poor students, began training for the project in 1992. Accelerated Schools were designed to advance the learning rate of students through a gifted and talented approach,…

  20. Cooperative Learning in Elementary Schools

    Science.gov (United States)

    Slavin, Robert E.

    2015-01-01

    Cooperative learning refers to instructional methods in which students work in small groups to help each other learn. Although cooperative learning methods are used for different age groups, they are particularly popular in elementary (primary) schools. This article discusses methods and theoretical perspectives on cooperative learning for the…

  1. Petrov classification: An elementary approach

    Energy Technology Data Exchange (ETDEWEB)

    Kalotas, T.M.; Eliezer, C.J.

    1983-01-01

    We reduce the length of the usual algebraic classification scheme of the Weyl tensor by avoiding the step centered around its reduction to canonical form. Instead the different algebraic types are established more economically via the elementary approach of constructing explicit examples.

  2. Elementary School Choirs and Auditions.

    Science.gov (United States)

    Haworth, Janice L.

    1992-01-01

    Contends that the question of whether to audition students for participation in elementary choirs is a difficult decision. Discusses the advantage and disadvantages of each choice. Concludes that the decision must be made according to educational objectives and the rationale for establishing the choir. (CFR)

  3. Play Therapy in Elementary Schools

    Science.gov (United States)

    Landreth, Garry L.; Ray, Dee C.; Bratton, Sue C.

    2009-01-01

    Because the child's world is a world of action and activity, play therapy provides the psychologist in elementary-school settings with an opportunity to enter the child's world. In the play therapy relationship, toys are like the child's words and play is the child's language. Therefore, children play out their problems, experiences, concerns, and…

  4. Elementary Students' Metaphors for Democracy

    Science.gov (United States)

    Dundar, Hakan

    2012-01-01

    The purpose of the research was to reveal elementary 8th grade students' opinions concerning democracy with the aid of metaphors. The students were asked to produce metaphors about the concept of democracy. 140 students from 3 public schools in Ankara (Turkey) participated in the research. 55% of the students were females and 45% were males. The…

  5. Elementary Algebra Connections to Precalculus

    Science.gov (United States)

    Lopez-Boada, Roberto; Daire, Sandra Arguelles

    2013-01-01

    This article examines the attitudes of some precalculus students to solve trigonometric and logarithmic equations and systems using the concepts of elementary algebra. With the goal of enticing the students to search for and use connections among mathematical topics, they are asked to solve equations or systems specifically designed to allow…

  6. Franklin Elementary PTA's "Sweet Success"

    Science.gov (United States)

    Freemon, Jennifer

    2012-01-01

    Just a few short years ago, Franklin Elementary in Glendale, California, was in danger of closing its doors because enrollment was so low. The school district decided to put into place a series of language immersion programs at the site. It currently houses Spanish, Italian, and German immersion programs. These programs have boosted Franklin's…

  7. Optimization Problems in Elementary Geometry

    Indian Academy of Sciences (India)

    Home; Journals; Resonance – Journal of Science Education; Volume 13; Issue 6. Optimization Problems in Elementary Geometry. A K Mallik. General Article Volume 13 Issue 6 June 2008 pp 561-582 ... Author Affiliations. A K Mallik1. Department Of Mechanical Engineering, Indian Institute of Technology, Kanpur, India.

  8. AIDS Elementary/Intermediate Curriculum.

    Science.gov (United States)

    Kellogg, Nancy Rader

    This Acquired Immune Deficiency Syndrome (AIDS) Curriculum was developed for intermediate elementary (5th, 6th, and 7th grade) students. It is an integrated unit that encompasses health, science, social studies, math, and language arts. The curriculum is comprised of nine class activities designed to meet the following objectives: (1) to determine…

  9. Fundamentals of gas particle flow

    CERN Document Server

    Rudinger, G

    1980-01-01

    Fundamentals of Gas-Particle Flow is an edited, updated, and expanded version of a number of lectures presented on the "Gas-Solid Suspensions” course organized by the von Karman Institute for Fluid Dynamics. Materials presented in this book are mostly analytical in nature, but some experimental techniques are included. The book focuses on relaxation processes, including the viscous drag of single particles, drag in gas-particles flow, gas-particle heat transfer, equilibrium, and frozen flow. It also discusses the dynamics of single particles, such as particles in an arbitrary flow, in a r

  10. Experimental Set-up for Irradiation of Solid H2 and D2 with Charged Particles of keV Energies

    DEFF Research Database (Denmark)

    Sørensen, H.

    1976-01-01

    An experimental facility was built where films of solid deuterium (and hydrogen) may be made with known thickness and irradiated with pulsed beams of electrons (up to 3 keV) and light ions (up to 10 keV). Films are made on a target plate held at 2.5–3 K. Film growth rate is calibrated with a quar...

  11. Experimental evidence of a stratospheric circulation influence on mesospheric temperatures and ice-particles during the 2010-2011 austral summer at 69°S

    Science.gov (United States)

    Morris, Ray J.; Höffner, Josef; Lübken, Franz-Josef; Viehl, Timo P.; Kaifler, Bernd; Klekociuk, Andrew R.

    2012-11-01

    A significant inter-annual decrease in polar mesosphere ice-particles, i.e., PMSE and PMC, during 2010-2011 is compared with earlier austral summers, in particular with 2009-2010. The first IAP iron lidar temperature measurement at Davis (68.6°S), Antarctica from 14 December 2010 are used to assess thermal effects of atmospheric processes on the mesopause region. We report low average temperatures of ˜125 K measured by Fe-lidar near 90 km when the PMSE season commenced, whereas temperatures were warmer in 2010-2011 compared to 2009-2010 at altitudes where PMSE normally occur (around 86 km). Summer mesopause region temperature anomalies are derived using Aura MLS records. We reveal that the late break-down of the Antarctic stratospheric polar vortex on 5 January 2010, coupled with enhanced early summer mesospheric zonal wind field, provide a barrier to upward propagation of atmospheric gravity waves to be the main mechanism for the observed warm early summer season below the mesopause. The mesopause in 2010-2011 was unusually high and cold. We conclude that the timing of the annual break-down of the southern polar stratospheric vortex as manifest in zonal winds at 30 hPa impacts mesosphere temperature and ice-particle formation early in the austral summer.

  12. An experimental investigation on morphological, mechanical and thermal properties of date palm particles reinforced polyurethane composites as new ecological insulating materials in building

    Directory of Open Access Journals (Sweden)

    A. Oushabi

    2017-12-01

    Full Text Available The rigid polyurethane (PU with apparent density about 40 kg/m3 was prepared using commercial polyols and polyisocyanate. This reference petrochemical formulation was modified with natural and renewable components such as date palm particles (DPP. The goal of this investigation was to reduce the environmental impacts, and reduce the cost of the petroleum based polyurethane (PU by obtaining polyurethane/date palm particles (PU-DPP composites with the heat insulating and mechanical properties similar or better as in the case of the reference material (PU. The composites were prepared with different (DPP loading; 5%, 10%, and 20% (by weight. The results showed that heat insulating and mechanical properties of the (PU-DPP composites were comparable with those from reference petrochemical formulation (PU. On the other hand these mechanical and thermal performances are competitive with those of other insulating material available on the market. Hence the (PU-DPP is a good candidate for development of efficient, low cost, and safe insulating materials.

  13. Enriching Elementary Quantum Mechanics with the Computer: Self-Consistent Field Problems in One Dimension

    Science.gov (United States)

    Bolemon, Jay S.; Etzold, David J.

    1974-01-01

    Discusses the use of a small computer to solve self-consistent field problems of one-dimensional systems of two or more interacting particles in an elementary quantum mechanics course. Indicates that the calculation can serve as a useful introduction to the iterative technique. (CC)

  14. Current Experiments in Particle Physics (September 1996)

    Energy Technology Data Exchange (ETDEWEB)

    Galic, H.; Lehar, F.; Klyukhin, V.I.; Ryabov, Yu.G.; Bilak, S.V.; Illarionova, N.S.; Khachaturov, B.A.; Strokovsky, E.A.; Hoffman, C.M.; Kettle, P.-R.; Olin, A.; Armstrong, F.E.

    1996-09-01

    This report contains summaries of current and recent experiments in Particle Physics. Included are experiments at BEPC (Beijing), BNL, CEBAF, CERN, CESR, DESY, FNAL, Frascati, ITEP (Moscow), JINR (Dubna), KEK, LAMPF, Novosibirsk, PNPI (St. Petersburg), PSI, Saclay, Serpukhov, SLAC, and TRIUMF, and also several proton decay and solar neutrino experiments. Excluded are experiments that finished taking data before 1991. Instructions are given for the World Wide Web (WWW) searching of the computer database (maintained under the SLAC-SPIRES system) that contains the summaries. This report contains full summaries of 180 approved current and recent experiments in elementary particle physics. The focus of the report is on selected experiments which directly contribute to our better understanding of elementary particles and their properties such as masses, widths or lifetimes, and branching fractions.

  15. Particle detectors

    CERN Multimedia

    CERN. Geneva

    1999-01-01

    Introduction, interaction of radiation with matter measurement of momentum of charged particles, of energy of e/gamma, hadrons, identification of particles. Design of HEP detectors. Principle of operation and performance of tracking sub-detectors, calorimeters and muon system.

  16. Maxwell's equations and their consequences elementary electromagnetic theory

    CERN Document Server

    Chirgwin, B H; Kilmister, C W 0

    2013-01-01

    Elementary Electromagnetic Theory Volume 3: Maxwell's Equations and their Consequences is the third of three volumes that intend to cover electromagnetism and its potential theory. The third volume considers the implications of Maxwell's equations, such as electromagnetic radiation in simple cases, and its relation between Maxwell's equation and the Lorenz transformation. Included in this volume are chapters 11-14, which contain an in-depth discussion of the following topics: Electromagnetic Waves The Lorentz Invariance of Maxwell's Equation Radiation Motion of Charged Particles Intended

  17. An introduction to particle dark matter

    CERN Document Server

    Profumo, Stefano

    2017-01-01

    What is the dark matter that fills the Universe and binds together galaxies? How was it produced? What are its interactions and particle properties?The paradigm of dark matter is one of the key developments at the interface of cosmology and elementary particle physics. It is also one of the foundations of the standard cosmological model. This book presents the state of the art in building and testing particle models for dark matter. Each chapter gives an analysis of questions, research directions, and methods within the field. More than 200 problems are included to challenge and stimulate the reader's knowledge and provide guidance in the practical implementation of the numerous 'tools of the trade' presented. Appendices summarize the basics of cosmology and particle physics needed for any quantitative understanding of particle models for dark matter.This interdisciplinary textbook is essential reading for anyone interested in the microscopic nature of dark matter as it manifests itself in particle physics ex...

  18. Elementary principles of linear accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Loew, G.A.; Talman, R.

    1983-09-01

    These lectures come in five sections. The first is this introduction. The second is a short chronology of what are viewed as important milestones in the field. The third covers proton linacs. It introduces elementary concepts such as transit time, shunt impedance, and Q. Critical issues such as phase stability and transverse forces are discussed. The fourth section contains an elementary discussion of waveguide accelerating structures. It can be regarded as an introduction to some of the more advanced treatments of the subject. The final section is devoted to electron accelerators. Taking SLAC as an example, various topics are discussed such as structure design, choice of parameters, frequency optimization, beam current, emittance, bunch length and beam loading. Recent developments and future challenges are mentioned briefly. 41 figures, 4 tables.

  19. Removal of antibiotics from water in the coexistence of suspended particles and natural organic matters using amino-acid-modified-chitosan flocculants: A combined experimental and theoretical study.

    Science.gov (United States)

    Jia, Shuying; Yang, Zhen; Ren, Kexin; Tian, Ziqi; Dong, Chang; Ma, Ruixue; Yu, Ge; Yang, Weiben

    2016-11-05

    Contamination of trace antibiotics is widely found in surface water sources. This work delineates removal of trace antibiotics (norfloxacin (NOR), sulfadiazine (SDZ) or tylosin (TYL)) from synthetic surface water by flocculation, in the coexistence of inorganic suspended particles (kaolin) and natural organic matter (humic acid, HA). To avoid extra pollution caused by petrochemical products-based modification reagents, environmental-friendly amino-acid-modified-chitosan flocculants, Ctrp and Ctyr, with different functional aromatic-rings structures were employed. Jar tests at various pHs exhibited that, Ctyr, owning phenol groups as electron donors, was favored for elimination of cationic NOR (∼50% removal; optimal pH: 6; optimal dosage: 4mg/L) and TYL (∼60% removal; optimal pH: 7; optimal dosage: 7.5mg/L), due to π-π electron donator-acceptor (EDA) effect and unconventional H-bonds. Differently, Ctrp with indole groups as electron acceptor had better removal rate (∼50%) of SDZ anions (electron donator). According to correlation analysis, the coexisted kaolin and HA played positive roles in antibiotics' removal. Detailed pairwise interactions in molecular level among different components were clarified by spectral analysis and theoretical calculations (density functional theory), which are important for both the structural design of new flocculants aiming at targeted contaminants and understanding the environmental behaviors of antibiotics in water. Copyright © 2016 Elsevier B.V. All rights reserved.

  20. Ice particle collisions

    Science.gov (United States)

    Sampara, Naresh; Turnbull, Barbara; Hill, Richard; Swift, Michael

    2017-04-01

    Granular interactions of ice occur in a range of geophysical, astrophysical and industrial applications. For example, Saturn's Rings are composed of icy particles from micrometers to kilometres in size - inertial and yet too small to interact gravitationally. In clouds, ice crystals are smashed to pieces before they re-aggregate to for snow floccules in a process that is very much open to interpretation. In a granular flow of ice particles, the energy spent in collisions can lead to localized surface changes and wetting, which in turn can promote aggregation. To understand the induced wetting and its effects, we present two novel experimental methods which provide snippets of insight into the collisional behaviour of macroscopic ice particles. Experiment 1: Microgravity experiments provide minute details of the contact between the ice particles during the collision. A diamagnetic levitation technique, as alternative to the parabolic flight or falling tower experiments, was used to understand the collisional behaviour of individual macroscopic icy bodies. A refrigerated cylinder, that can control ambient conditions, was inserted into the bore of an 18 Tesla superconducting magnet and cooled to -10°C. Initial binary collisions were created, where one 4 mm ice particle was levitated in the magnet bore whilst another particle was dropped vertically from the top of the bore. The trajectories of both particles were captured by high speed video to provide the three-dimensional particle velocities and track the collision outcome. Introducing complexity, multiple particles were levitated in the bore and an azimuthal turbulent air flow introduced, allowing the particles to collide with other particles within a coherent fluid structure (mimicking Saturn's rings, or an eddy in a cloud). In these experiments, a sequence of collisions occur, each one different to the previous one due to the changes in surface characteristics created by the collisions themselves. Aggregation