WorldWideScience

Sample records for test particles

  1. High Pressure Quick Disconnect Particle Impact Tests

    Science.gov (United States)

    Rosales, Keisa R.; Stoltzfus, Joel M.

    2009-01-01

    NASA Johnson Space Center White Sands Test Facility (WSTF) performed particle impact testing to determine whether there is a particle impact ignition hazard in the quick disconnects (QDs) in the Environmental Control and Life Support System (ECLSS) on the International Space Station (ISS). Testing included standard supersonic and subsonic particle impact tests on 15-5 PH stainless steel, as well as tests performed on a QD simulator. This paper summarizes the particle impact tests completed at WSTF. Although there was an ignition in Test Series 4, it was determined the ignition was caused by the presence of a machining imperfection. The sum of all the test results indicates that there is no particle impact ignition hazard in the ISS ECLSS QDs. KEYWORDS: quick disconnect, high pressure, particle impact testing, stainless steel

  2. Particle fuel bed tests

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Savino, J.M.

    1985-01-01

    Gas-cooled reactors, using packed beds of small diameter coated fuel particles have been proposed for compact, high-power systems. The particulate fuel used in the tests was 800 microns in diameter, consisting of a thoria kernel coated with 200 microns of pyrocarbon. Typically, the bed of fuel particles was contained in a ceramic cylinder with porous metallic frits at each end. A dc voltage was applied to the metallic frits and the resulting electric current heated the bed. Heat was removed by passing coolant (helium or hydrogen) through the bed. Candidate frit materials, rhenium, nickel, zirconium carbide, and zirconium oxide were unaffected, while tungsten and tungsten-rhenium lost weight and strength. Zirconium-carbide particles were tested at 2000 K in H 2 for 12 hours with no visible reaction or weight loss

  3. Cosmic censorship and test particles

    International Nuclear Information System (INIS)

    Needham, T.

    1980-01-01

    In this paper one unambiguous prediction of cosmic censorship is put to the test, namely that it should be impossible to destroy a black hole (i.e. eliminate its horizon) by injecting test particles into it. Several authors have treated this problem and have not found their conclusions in contradiction with the prediction. Here we prove that if a general charged spinning particle (with parameters very much smaller than the respective hole parameters) is injected in an arbitrary manner into an extreme Kerr-Newman black hole, then cosmic censorship is upheld. As a by-product of the analysis a natural proof is given of the Christodoulou-Ruffini conditions on the injection of a spinless particle which yield a reversible black-hole transformation. Finally we consider the injection of particles with parameters that are not small compared with those of the hole, for which cosmic censorship is apparently violated. By assuming the validity of cosmic censorship we are led to a few conjectures concerning the extent of the particle's interaction with the hole while approaching it

  4. Test-particle motion in Einstein's unified field theory. I. General theory and application to neutral test particles

    International Nuclear Information System (INIS)

    Johnson, C.R.

    1985-01-01

    We develop a method for finding the exact equations of structure and motion of multipole test particles in Einstein's unified field theory: the theory of the nonsymmetric field. The method is also applicable to Einstein's gravitational theory. Particles are represented by singularities in the field. The method is covariant at each step of the analysis. We also apply the method and find both in Einstein's unified field theory and in Einstein's gravitational theory the equations of structure and motion of neutral pole-dipole test particles possessing no electromagnetic multipole moments. In the case of Einstein's gravitational theory the results are the well-known equations of structure and motion of a neutral pole-dipole test particle in a given background gravitational field. In the case of Einstein's unified field theory the results are the same, providing we identify a certain symmetric second-rank tensor field appearing in Einstein's theory with the metric and gravitational field. We therefore discover not only the equations of structure and motion of a neutral test particle in Einstein's unified field theory, but we also discover what field in Einstein's theory plays the role of metric and gravitational field

  5. Training manuals for nondestructive testing using magnetic particles

    Science.gov (United States)

    1968-01-01

    Training manuals containing the fundamentals of nondestructive testing using magnetic particle as detection media are used by metal parts inspectors and quality assurance specialists. Magnetic particle testing involves magnetization of the test specimen, application of the magnetic particle and interpretation of the patterns formed.

  6. Polarization tests of one-particle-exchange mechanisms

    International Nuclear Information System (INIS)

    Goldstein, G.R.; Moravcsik, M.J.

    1984-01-01

    Since one-particle-exchange (OPE) mechanisms are predominant in all aspects of elementary-particle dynamics, a novel class of polarization tests is proposed for such mechanisms. They test whether a single particle of total angular momentum J is exchanged (''J constraints'') and whether the process can be factorized into two vertices (''factorization constraints''), but the tests are independent of more detailed dynamical features such as the exact nature of the coupling at the vertices. Except for a restricted type of processes containing some low spin values, the constraints reduce the number of reaction amplitudes and offer tests of OPE which are independent of the value of J. The tests have a particularly simple form in a ''magic'' formalism in which the quantization directions of the particles are in the reaction plane and are rotated from the helicity directions by a ''magic'' angle which can be easily specified for a given s and t. The tests consist of measuring whether a certain polarization quantity vanishes or not, thus providing sensitive ''null experiments'' for the exploration of particle dynamics. The results are illustrated on the popular reaction (1/2)+(1/2)→(1/2)+(1/2), which is embodied, for example, in elastic nucleon-nucleon scattering. The tests can be used either for one single-exchange mechanism or for a combination of such mechanisms (even if they involve different J exchanges), as long as they all have the same type of parity

  7. Magnetic Particle Testing, RQA/M1-5330.16.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    As one in the series of classroom training handbooks, prepared by the U.S. space program, instructional material is presented in this volume concerning familiarization and orientation on magnetic particle testing. The subject is divided under the following headings: Introduction, Principles of Magnetic Particle Testing, Magnetic Particle Test…

  8. Test-particle motion in Einstein's unified field theory. III. Magnetic monopoles and charged particles

    International Nuclear Information System (INIS)

    Johnson, C.R.

    1986-01-01

    In a previous paper (paper I), we developed a method for finding the exact equations of structure and motion of multipole test particles in Einstein's unified field theory: the theory of the nonsymmetric field. In that paper we also applied the method and found in Einstein's unified field theory the equations of structure and motion of neutral pole-dipole test particles possessing no electromagnetic multipole moments. In a second paper (paper II), we applied the method and found in Einstein's unified field theory the exact equations of structure and motion of charged test particles possessing no magnetic monopole moments. In the present paper (paper III), we apply the method and find in Einstein's unified field theory the exact equations of structure and motion of charged test particles possessing magnetic monopole moments. It follows from the form of these equations of structure and motion that in general in Einstein's unified field theory a test particle possessing a magnetic monopole moment in a background electromagnetic field must also possess spin

  9. Tests of candidate materials for particle bed reactors

    International Nuclear Information System (INIS)

    Horn, F.L.; Powell, J.R.; Wales, D.

    1987-01-01

    Rhenium metal hot frits and zirconium carbide-coated fuel particles appear suitable for use in flowing hydrogen to at least 2000 K, based on previous tests. Recent tests on alternate candidate cooled particle and frit materials are described. Silicon carbide-coated particles began to react with rhenium frit material at 1600 K, forming a molten silicide at 2000 K. Silicon carbide was extensively attacked by hydrogen at 2066 K for 30 minutes, losing 3.25% of its weight. Vitrous carbon was also rapidly attacked by hydrogen at 2123 K, losing 10% of its weight in two minutes. Long term material tests on candidate materials for closed cycle helium cooled particle bed fuel elements are also described. Surface imperfections were found on the surface of pyrocarbon-coated fuel particles after ninety days exposure to flowing (∼500 ppM) impure helium at 1143 K. The imperfections were superficial and did not affect particle strength

  10. Irradiation Testing of TRISO-Coated Particle Fuel in Korea

    International Nuclear Information System (INIS)

    Kim, Bong Goo; Yeo, Sunghwan; Jeong, Kyung-Chai; Eom, Sung-Ho; Kim, Yeon-Ku; Kim, Woong Ki; Lee, Young Woo; Cho, Moon Sung; Kim, Yong Wan

    2014-01-01

    In Korea, coated particle fuel is being developed to support development of a VHTR. At the end of March 2014, the first irradiation test in HANARO at KAERI to demonstrate and qualify TRISO-coated particle fuel for use in a VHTR was terminated. This experiment was conducted in an inert gas atmosphere without on-line temperature monitoring and control, or on-line fission product monitoring of the sweep gas. The irradiation device contained two test rods, one has nine fuel compacts and the other five compacts and eight graphite specimens. Each compact contains about 260 TRISO-coated particles. The duration of irradiation testing at HANARO was about 135 full power days from last August 2013. The maximum average power per particle was about 165 mW/particle. The calculated peak burnup of the TRISO-coated fuel was a little less than 4 atom percent. Post-irradiation examination is being carried out at KAERI’s Irradiated Material Examination Facility beginning in September of 2014. This paper describes characteristics of coated particle fuel, the design of the test rod and irradiation device for this coated particle fuel, and discusses the technical results of irradiation testing at HANARO. (author)

  11. Irradiation testing of coated particle fuel at Hanaro

    International Nuclear Information System (INIS)

    Goo Kim, Bong; Sung Cho, Moo; Kim, Yong Wan

    2014-01-01

    TRISO-coated particle fuel is developing to support development of VHTR in Korea. From August 2013, the first irradiation testing of coated particle fuel was begun to demonstrate and qualify TRISO fuel for use in VHTR in the HANARO at KAERI. This experiment is currently undergoing under the atmosphere of a mixed inert gas without on-line temperature monitoring and control combined with on-line fission product monitoring of the sweep gas. The irradiation device contains two test rods, one contains nine fuel compacts and the other five compacts and eight graphite specimens. Each compact has 263 coated particles. After a peak burn-up of about 4 at% and a peak fast neutron fluence of about 1.7 x 10 21 n/cm 2 , PIE will be carried out at KAERI's Irradiated Material Examination Facility. This paper is described characteristics of coated particle fuel, the design of test rod and irradiation device for coated particle fuel, discusses the technical results for irradiation testing at HANARO. (authors)

  12. Experimental Tests of Particle Flow Calorimetry

    CERN Document Server

    Sefkow, Felix; Kawagoe, Kiyotomo; Pöschl, Roman; Repond, José

    2016-01-01

    Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10 - 15 years of R\\&D, mainly conducted within the CALICE collaboration, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g.\\ hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previously.

  13. Experimental tests of particle flow calorimetry

    International Nuclear Information System (INIS)

    Sefkow, Felix; White, Andy; Kawagoe, Kiyotomo; Poeschl, Roman; Repond, Jose

    2015-07-01

    Precision physics at future colliders requires highly granular calorimeters to support the Particle Flow Approach for event reconstruction. This article presents a review of about 10-15 years of R and D, mainly conducted within the CALICE collaboration, for this novel type of detector. The performance of large scale prototypes in beam tests validate the technical concept of particle flow calorimeters. The comparison of test beam data with simulation, of e.g. hadronic showers, supports full detector studies and gives deeper insight into the structure of hadronic cascades than was possible previously.

  14. Test-particle motion in the nonsymmetric gravitation theory

    International Nuclear Information System (INIS)

    Moffat, J.W.

    1987-01-01

    A derivation of the motion of test particles in the nonsymmetric gravitational theory (NGT) is given using the field equations in the presence of matter. The motion of the particle is governed by the Christoffel symbols, which are formed from the symmetric part of the fundamental tensor g/sub μ//sub ν/, as well as by a tensorial piece determined by the skew part of the contracted curvature tensor R/sub μ//sub ν/. Given the energy-momentum tensor for a perfect fluid and the definition of a test particle in the NGT, the equations of motion follow from the conservation laws. The tensorial piece in the equations of motion describes a new force in nature that acts on the conserved charge in a body. Particles that carry this new charge do not follow geodesic world lines in the NGT, whereas photons do satisfy geodesic equations of motion and the equivalence principle of general relativity. Astronomical predictions, based on the exact static, spherically symmetric solution of the field equations in a vacuum and the test-particle equations of motion, are derived in detail. The maximally extended coordinates that remove the event-horizon singularities in the static, spherically symmetric solution are presented. It is shown how an inward radially falling test particle can be prevented from forming an event horizon for a value greater than a specified critical value of the source charge. If a test particle does fall through an event horizon, then it must continue to fall until it reaches the singularity at r = 0

  15. Test-particle motion in the nonsymmetric gravitation theory

    Science.gov (United States)

    Moffat, J. W.

    1987-06-01

    A derivation of the motion of test particles in the nonsymmetric gravitational theory (NGT) is given using the field equations in the presence of matter. The motion of the particle is governed by the Christoffel symbols, which are formed from the symmetric part of the fundamental tensor gμν, as well as by a tensorial piece determined by the skew part of the contracted curvature tensor Rμν. Given the energy-momentum tensor for a perfect fluid and the definition of a test particle in the NGT, the equations of motion follow from the conservation laws. The tensorial piece in the equations of motion describes a new force in nature that acts on the conserved charge in a body. Particles that carry this new charge do not follow geodesic world lines in the NGT, whereas photons do satisfy geodesic equations of motion and the equivalence principle of general relativity. Astronomical predictions, based on the exact static, spherically symmetric solution of the field equations in a vacuum and the test-particle equations of motion, are derived in detail. The maximally extended coordinates that remove the event-horizon singularities in the static, spherically symmetric solution are presented. It is shown how an inward radially falling test particle can be prevented from forming an event horizon for a value greater than a specified critical value of the source charge. If a test particle does fall through an event horizon, then it must continue to fall until it reaches the singularity at r=0.

  16. Potential of the test particle in the magnetic field. I

    International Nuclear Information System (INIS)

    Sestak, B.

    1980-01-01

    The problem of the test particle potential in an external homogeneous magnetic field is solved in an unmagnetized plasma. It is shown that for the case when the parallel velocity component of the test particle is greater than the thermal velocity of the background particles, the potential is of a Coulomb character while for the case where the parallel velocity component is less than the thermal velocity the potential is of a Debye character. The Larmor radius of the test particle appears as an additional parameter in these potentials. (author)

  17. AE Test of Calcareous Sands with Particle Rushing

    Directory of Open Access Journals (Sweden)

    Tan Fengyi

    2017-08-01

    Full Text Available The particle of calcareous sands was forced to crush, then the energy from the crushing was released by the form of sound waves. Therefore the AE technique was used to detect the calcareous sands AE signal when it crushed. by to study the AE characteristics, the mechanics of calcareous sands was studied. Study showed that: (1 there was the AE activities on the low confining pressure condition at the beginnig of test, (2 there was more and more AE activities with the continuing of test until to the end, (3 the calcareous sands’ AE activities was on the whole testing, (4 the calcareous sands’ particle crushing and mutual friction played different roles for its AE activities. Then the AE model based on the calcarous sands’ particle crushing was discussed.

  18. Test Particles with Acceleration-Dependent Lagrangian

    OpenAIRE

    Toller, M.

    2005-01-01

    We consider a classical test particle subject to electromagnetic and gravitational fields, described by a Lagrangian depending on the acceleration and on a fundamental length. We associate to the particle a moving local reference frame and we study its trajectory in the principal fibre bundle of all the Lorentz frames. We discuss in this framework the general form of the Lagrange equations and the connection between symmetries and conservation laws (Noether theorem). We apply these results to...

  19. Probing Minicharged Particles with Tests of Coulomb's Law

    International Nuclear Information System (INIS)

    Jaeckel, Joerg

    2009-01-01

    Minicharged particles arise in many extensions of the standard model. Their contribution to the vacuum polarization modifies Coulomb's law via the Uehling potential. In this Letter, we argue that tests for electromagnetic fifth forces can therefore be a sensitive probe of minicharged particles. In the low mass range < or approx. μeV existing constraints from Cavendish type experiments provide the best model-independent bounds on minicharged particles.

  20. Motion of charged test particles in Reissner-Nordstroem spacetime

    International Nuclear Information System (INIS)

    Pugliese, Daniela; Quevedo, Hernando; Ruffini, Remo

    2011-01-01

    We investigate the circular motion of charged test particles in the gravitational field of a charged mass described by the Reissner-Nordstroem spacetime. We study in detail all the spatial regions where circular motion is allowed around either black holes or naked singularities. The effects of repulsive gravity are discussed by finding all the circles at which a particle can have vanishing angular momentum. We show that the geometric structure of stable accretion disks, made of only test particles moving along circular orbits around the central body, allows us to clearly distinguish between black holes and naked singularities.

  1. THE ECCENTRIC KOZAI MECHANISM FOR A TEST PARTICLE

    International Nuclear Information System (INIS)

    Lithwick, Yoram; Naoz, Smadar

    2011-01-01

    We study the dynamical evolution of a test particle that orbits a star in the presence of an exterior massive planet, considering octupole-order secular interactions. In the standard Kozai mechanism (SKM), the planet's orbit is circular and so the particle conserves vertical angular momentum. As a result, the particle's orbit oscillates periodically, exchanging eccentricity for inclination. However, when the planet's orbit is eccentric, the particle's vertical angular momentum varies and its Kozai oscillations are modulated on longer timescales—we call this the eccentric Kozai mechanism (EKM). The EKM can lead to behavior that is dramatically different from the SKM. In particular, the particle's orbit can flip from prograde to retrograde and back again, and it can reach arbitrarily high eccentricities given enough time. We map out the conditions under which this dramatic behavior (flipping and extreme eccentricities) occurs and show that when the planet's eccentricity is sufficiently high, it occurs quite generically. For example, when the planet's eccentricity exceeds a few percent of the ratio of semimajor axes (outer to inner), around half of randomly oriented test particle orbits will flip and reach extreme eccentricities. The SKM has often been invoked for bringing pairs of astronomical bodies (star-star, planet-star, compact-object pairs) close together. Including the effect of the EKM will enhance the rate at which such matchmaking occurs.

  2. Test particle calculations for the Texas experimental tokamak with resonant magnetic fields

    International Nuclear Information System (INIS)

    Wootton, A.J.; McCool, S.C.; Zheng, S.

    1991-01-01

    This paper presents a simple test particle model that attempts to describe particle motion in the presence of intrinsic electrostatic fluctuations in a prescribed tokamak magnetic field. In particular, magnetic field configurations that include externally produced magnetic islands and stochastic regions are considered. The resulting test particle transport is compared with the predictions of analytic models and with the experimentally measured electron heat and particle transport on the Texas Experimental Tokamak (TEXT). Agreement between the test particle results and applicable analytic theories is found. However, there is only partial agreement with the experimental results, and possible reasons for the discrepancies are explored. Good agreement is found between predicted and measured spatially asymmetric particle distributions. The particle collection efficiency of an apertured limiter inside a magnetic island (an intra-island pump limiter) is discussed

  3. Variational Algorithms for Test Particle Trajectories

    Science.gov (United States)

    Ellison, C. Leland; Finn, John M.; Qin, Hong; Tang, William M.

    2015-11-01

    The theory of variational integration provides a novel framework for constructing conservative numerical methods for magnetized test particle dynamics. The retention of conservation laws in the numerical time advance captures the correct qualitative behavior of the long time dynamics. For modeling the Lorentz force system, new variational integrators have been developed that are both symplectic and electromagnetically gauge invariant. For guiding center test particle dynamics, discretization of the phase-space action principle yields multistep variational algorithms, in general. Obtaining the desired long-term numerical fidelity requires mitigation of the multistep method's parasitic modes or applying a discretization scheme that possesses a discrete degeneracy to yield a one-step method. Dissipative effects may be modeled using Lagrange-D'Alembert variational principles. Numerical results will be presented using a new numerical platform that interfaces with popular equilibrium codes and utilizes parallel hardware to achieve reduced times to solution. This work was supported by DOE Contract DE-AC02-09CH11466.

  4. Test of a Diamond Detector Using Unbunched Beam Halo Particles

    CERN Document Server

    Dehning, B; Pernegger, H; Dobos, D; Frais-Kolbl, H; Griesmayer, E

    2010-01-01

    A pCVD diamond detector has been evaluated as a beam loss monitor for future applications in the LHC accelerator. The test monitor was mounted in the SPS BA5 downstream of a LHC collimator during the LHC beam set-up. CVD diamond particle detectors are already in use in the CERN experiments ATLAS, CMS, LHCb and Alice. This is a proven technology with high radiation tolerance and very fast signal read-out. It can be used for single-particle detection, as well as for measuring particle cascades, for timing measurements on the nanosecond scale and for beam protection systems. Despite the read-out being made through 250 m of CK50 cable, the tests have shown a very good signal-to-noise ratio of 6.8, an excellent double-pulse resolution of less than 5 ns and a high dynamic range of 1:350 MIP particles. The efficiency of particle detection is practically 100% for charged particles.

  5. Spinning charged test particles and Cosmic Censorship

    Energy Technology Data Exchange (ETDEWEB)

    Caderni, N [Cambridge Univ. Inst. of Astronomy (UK); Calvani, M [Padua Univ. (Italy). Ist. di Astronomia

    1979-04-16

    The authors consider spinning charged test particles in the gravitational field of a rotating charged black hole, and it is shown that the hole cannot be destroyed, according to the Cosmic Censorship hypothesis.

  6. Analogue particle identifier and test unit for automatic measuring of errors

    International Nuclear Information System (INIS)

    Boden, A.; Lauch, J.

    1979-04-01

    A high accuracy analogue particle identifier is described. The unit is used for particle identification or data correction of experimental based errors in magnetic spectrometers. Signals which are proportional to the energy, the time-of-flight or the position of absorption of the particles are supplied to an analogue computation circuit (multifunction converter). Three computation functions are available for different applications. The output of the identifier produces correction signals or pulses whose amplitudes are proportional to the mass of the particles. Particle identification and data correction can be optimized by the adjustment of variable parameters. An automatic test unit has been developed for adjustment and routine checking of particle identifiers. The computation functions can be tested by this unit with an accuracy of 1%. (orig.) [de

  7. Test particle trajectories near cosmic strings

    Indian Academy of Sciences (India)

    We present a detailed analysis of the motion of test particle in the gravitational field of cosmic strings in different situations using the Hamilton–Jacobi (H–J) formalism. We have discussed the trajectories near static cosmic string, cosmic string in Brans–Dicke theory and cosmic string in dilaton gravity.

  8. Spinning charged test particles and Cosmic Censorship

    International Nuclear Information System (INIS)

    Caderni, N.; Calvani, M.

    1979-01-01

    The authors consider spinning charged test particles in the gravitational field of a rotating charged black hole, and it is shown that the hole cannot be destroyed, according to the Cosmic Censorship hypothesis. (Auth.)

  9. Quantum spacetime operationally based on propagators for extended test particles

    International Nuclear Information System (INIS)

    Prugovecki, E.

    1981-01-01

    By taking into account the quantum aspects intrinsic to any operational definition of spatio-temporal relationships, a stochastic concept of spacetime emerges. In relation to its classical counterpart is realized as a stochastic mean around which quantum fluctuations become negligible only in the limit of macroscopic spacetime intervals. The test-particle propagators used in the proposed quantum concept of spacetime are derived by solving in a consistent manner the localizability problem for relativistic particles. This is achieved in the framework of the stochastic phase space formulation of quantum mechanics, which in the nonrelativistic context is shown to result from systems of imprimitivity related to phase space conserved probability currents derivable from bona fide convariant probability densities in stochastic phase spaces of one particle systems, which can be interpreted as due to measurements performed with extended rather than pointlike test particles. The associated particle propagators can be therefore consistently related to coordinate probability densities measurable by the exchange of photons in between test particles from a chosen standard. Quantum spacetime is defined as the family of propagators corresponding to all conceivable coherent flows of test particles. This family of free-fall propagators has to satisfy certain self-consistency conditions as well as consistent laws of motion which inplicitly determine the stochastic geometro-dynamics of quantum space-time. Field theory on quantum spacetime retains many of the formal features of conventional quantum field theory. On a fundamental epistemological level stochastic geometries emerge as essential prerequisites in the construction of spacetime models that would be operationally based and yet consistent with the relativity principle as well as with the uncertinty principle

  10. Fractal and Morphological Characteristics of Single Marble Particle Crushing in Uniaxial Compression Tests

    Directory of Open Access Journals (Sweden)

    Yidong Wang

    2015-01-01

    Full Text Available Crushing of rock particles is a phenomenon commonly encountered in geotechnical engineering practice. It is however difficult to study the crushing of rock particles using classical theory because the physical structure of the particles is complex and irregular. This paper aims at evaluating fractal and morphological characteristics of single rock particle. A large number of particle crushing tests are conducted on single rock particle. The force-displacement curves and the particle size distributions (PSD of crushed particles are analysed based on particle crushing tests. Particle shape plays an important role in both the micro- and macroscale responses of a granular assembly. The PSD of an assortment of rocks are analysed by fractal methods, and the fractal dimension is obtained. A theoretical formula for particle crushing strength is derived, utilising the fractal model, and a simple method is proposed for predicting the probability of particle survival based on the Weibull statistics. Based on a few physical assumptions, simple equations are derived for determining particle crushing energy. The results of applying these equations are tested against the actual experimental data and prove to be very consistent. Fractal theory is therefore applicable for analysis of particle crushing.

  11. Simulation of Particle Fluxes at the DESY-II Test Beam Facility

    International Nuclear Information System (INIS)

    Schuetz, Anne

    2015-05-01

    In the course of this Master's thesis ''Simulation of Particle Fluxes at the DESY-II Test Beam Facility'' the test beam generation for the DESY test beam line was studied in detail and simulated with the simulation software SLIC. SLIC uses the Geant4 toolkit for realistic Monte Carlo simulations of particles passing through detector material.After discussing the physics processes relevant for the test beam generation and the principles of the beam generation itself, the software used is introduced together with a description of the functionality of the Geant4 Monte Carlo simulation. The simulation of the test beam line follows the sequence of the test beam generation. Therefore, it starts with the simulation of the beam bunch of the synchrotron accelerator DESY-II, and proceeds step by step with the single test beam line components. An additional benefit of this thesis is the provision of particle flux and trajectory maps, which make fluxes directly visible by following the particle tracks through the simulated beam line. These maps allow us to see each of the test beam line components, because flux rates and directions change rapidly at these points. They will also guide the decision for placements of future test beam line components and measurement equipment.In the end, the beam energy and its spread, and the beam rate of the final test beam in the test beam area were studied in the simulation, so that the results can be compared to the measured beam parameters. The test beam simulation of this Master's thesis will serve as a key input for future test beam line improvements.

  12. Test Method for High β Particle Emission Rate of 63Ni Source Plate

    OpenAIRE

    ZHANG Li-feng

    2015-01-01

    For the problem of measurement difficulties of β particle emission rate of Ni-63 source plate used for Ni-63 betavoltaic battery, a relative test method of scintillation current method was erected according to the measurement principle of scintillation detector.β particle emission rate of homemade Ni-63 source plate was tested by the method, and the test results were analysed and evaluated, it was initially thought that scintillation current method was a feasible way of testing β particle emi...

  13. A conformal invariant model of localized spinning test particles

    International Nuclear Information System (INIS)

    Duval, C.; Centre National de la Recherche Scientifique, 13 - Marseille; Fliche, H.H.; Centre National de la Recherche Scientifique, 13 - Marseille

    1977-02-01

    A purely classical model of massless test particle with spin s is introduced as the dynamical system defined by the 10 dimensional 0(4,2) co-adjoint orbit with Casimir numbers (s 2 ,0,0). The Mathisson Papapetrou et al. equations of motion in a gravitational field are recovered, and moreover the particle appears to travel on null geodesics. Several implications are discussed

  14. Erosion tests of materials by energetic particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Schechter, D.E.; Tsai, C.C.; Sluss, F.; Becraft, W.R.; Hoffman, D.J.

    1985-01-01

    The internal components of magnetic fusion devices must withstand erosion from and high heat flux of energetic plasma particles. The selection of materials for the construction of these components is important to minimize contamination of the plasma. In order to study various materials' comparative resistance to erosion by energetic particles and their ability to withstand high heat flux, water-cooled copper swirl tubes coated or armored with various materials were subjected to bombardment by hydrogen and helium particle beams. Materials tested were graphite, titanium carbide (TiC), chromium, nickel, copper, silver, gold, and aluminum. Details of the experimental arrangement and methods of application or attachment of the materials to the copper swirl tubes are presented. Results including survivability and mass losses are discussed.

  15. Test particle modeling of wave-induced energetic electron precipitation

    International Nuclear Information System (INIS)

    Chang, H.C.; Inan, U.S.

    1985-01-01

    A test particle computer model of the precipitation of radiation belt electrons is extended to compute the dynamic energy spectrum of transient electron fluxes induced by short-duration VLF wave packets traveling along the geomagnetic field lines. The model is adapted to estimate the count rate and associated spectrum of precipitated electrons that would be observed by satellite-based particle detectors with given geometric factor and orientation with respect to the magnetic field. A constant-frequency wave pulse and a lightning-induced whistler wave packet are used as examples of the stimulating wave signals. The effects of asymmetry of particle mirror heights in the two hemispheres and the atmospheric backscatter of loss cone particles on the computed precipitated fluxes are discussed

  16. Particle Beam Tests of the Calorimetric Electron Telescope

    CERN Document Server

    Tamura, Tadahisa

    The Calorimetric Electron Telescope (CALET) is a new mission addressing outstanding astrophysics questions including the nature of dark matter, the sources of high-energy particles and photons, and the details of particle acceleration and transport in the galaxy by measuring the high-energy spectra of electrons, nuclei, and gamma-rays. It will launch on HTV-5 (H-II Transfer Vehicle 5) in 2014 for installation on the Japanese Experiment Module–Exposed Facility (JEM-EF) of the International Space Station. The CALET collaboration is led by JAXA and includes researchers from Japan, the U.S. and Italy. The CALET Main Telescope uses a plastic scintillator charge detector followed by a 30 radiation-length (X0) deep particle calorimeter divided into a 3 X0 imaging calorimeter, with scintillating optical fibers interleaved with thin tungsten sheets, and a 27 X0 fully-active total-absorption calorimeter made of lead tungstate scintillators. CALET prototypes were tested at the CERN (European Laboratory for Particle Ph...

  17. Radiological dispersal device outdoor simulation test: Cesium chloride particle characteristics

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Don, E-mail: lee.sangdon@epa.gov [U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Snyder, Emily G.; Willis, Robert [U.S. Environmental Protection Agency, Research Triangle Park, NC 27711 (United States); Fischer, Robert; Gates-Anderson, Dianne; Sutton, Mark [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Viani, Brian [Simbol Mining Corp., Pleasanton, CA 94566 (United States); Drake, John [U.S. Environmental Protection Agency, Cincinnati, OH 45268 (United States); MacKinney, John [U.S. Department of Homeland Security, Washington, DC 20528 (United States)

    2010-04-15

    Particles were generated from the detonation of simulated radiological dispersal devices (RDDs) using non-radioactive CsCl powder and explosive C4. The physical and chemical properties of the resulting particles were characterized. Two RDD simulation tests were conducted at Lawrence Livermore National Laboratory: one of the simulated RDDs was positioned 1 m above a steel plate and the other was partially buried in soil. Particles were collected with filters at a distance of 150 m from the origin of the RDD device, and particle mass concentrations were monitored to identify the particle plume intensity using real time particle samplers. Particles collected on filters were analyzed via computer-controlled scanning electron microscopy coupled with energy dispersive X-ray spectrometry (CCSEM/EDX) to determine their size distribution, morphology, and chemical constituents. This analysis showed that particles generated by the detonation of explosives can be associated with other materials (e.g., soil) that are in close proximity to the RDD device and that the morphology and chemical makeup of the particles change depending on the interactions of the RDD device with the surrounding materials.

  18. Radiological dispersal device outdoor simulation test: Cesium chloride particle characteristics

    International Nuclear Information System (INIS)

    Lee, Sang Don; Snyder, Emily G.; Willis, Robert; Fischer, Robert; Gates-Anderson, Dianne; Sutton, Mark; Viani, Brian; Drake, John; MacKinney, John

    2010-01-01

    Particles were generated from the detonation of simulated radiological dispersal devices (RDDs) using non-radioactive CsCl powder and explosive C4. The physical and chemical properties of the resulting particles were characterized. Two RDD simulation tests were conducted at Lawrence Livermore National Laboratory: one of the simulated RDDs was positioned 1 m above a steel plate and the other was partially buried in soil. Particles were collected with filters at a distance of 150 m from the origin of the RDD device, and particle mass concentrations were monitored to identify the particle plume intensity using real time particle samplers. Particles collected on filters were analyzed via computer-controlled scanning electron microscopy coupled with energy dispersive X-ray spectrometry (CCSEM/EDX) to determine their size distribution, morphology, and chemical constituents. This analysis showed that particles generated by the detonation of explosives can be associated with other materials (e.g., soil) that are in close proximity to the RDD device and that the morphology and chemical makeup of the particles change depending on the interactions of the RDD device with the surrounding materials.

  19. Motion of a spinning test particle in Vaidya's radiating metric

    International Nuclear Information System (INIS)

    Carmeli, M.; Charach, C.; Kaye, M.

    1977-01-01

    The motion of a spinning test particle in Vaidya's gravitational field is considered in the framework of Papapetrou's equations of motion. Use is made of the supplementary condition S/sup μ//sup u/ = 0, where u is the retarded Schwarzschild time coordinate. We derive the equations for the dynamical variables, and consider the conservation laws, that follow from the equations of motion. Particular cases of motion are also discussed and additional first integrals corresponding to these cases are found. Some of the new extra integrals are related to the Casimir operators of the Poincare group. It is found that under special conditions on the spin tensor components the particle follows a geodesic. Motion of the spinning test particle in the Schwarzschild field is considered as one of the particular cases

  20. In-pile tests of HTGR fuel particles and fuel elements

    International Nuclear Information System (INIS)

    Chernikov, A.S.; Kolesov, V.S.; Deryugin, A.I.

    1985-01-01

    Main types of in-pile tests for specimen tightness control at the initial step, research of fuel particle radiation stability and also study of fission product release from fuel elements during irradiation are described in this paper. Schemes and main characteristics of devices used for these tests are also given. Principal results of fission gas product release measurements satisfying HTGR demands are illustrated on the example of fuel elements, manufactured by powder metallurgy methods and having TRISO fuel particles on high temperature pyrocarbon and silicon carbide base. (author)

  1. Stopping power for arbitrary angle between test particle velocity and magnetic field

    International Nuclear Information System (INIS)

    Cereceda, Carlo; Peretti, Michel de; Deutsch, Claude

    2005-01-01

    Using the longitudinal dielectric function derived previously for charged test particles in helical movement around magnetic field lines, the numerical convergence of the series involved is found and the double numerical integrations on wave vector components are performed yielding the stopping power for arbitrary angle between the test particle velocity and magnetic field. Calculations are performed for particle Larmor radius larger and shorter than Debye length, i.e., for protons in a cold magnetized plasma and for thermonuclear α particles in a dense, hot, and strongly magnetized plasma. A strong decrease is found for the energy loss as the angle varies from 0 to π/2. The range of thermonuclear α particles as a function of the velocity angle with respect to the magnetic field is also given

  2. Benchmark tests and spin adaptation for the particle-particle random phase approximation

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Yang; Steinmann, Stephan N.; Peng, Degao [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Aggelen, Helen van, E-mail: Helen.VanAggelen@UGent.be [Department of Chemistry, Duke University, Durham, North Carolina 27708 (United States); Department of Inorganic and Physical Chemistry, Ghent University, 9000 Ghent (Belgium); Yang, Weitao, E-mail: Weitao.Yang@duke.edu [Department of Chemistry and Department of Physics, Duke University, Durham, North Carolina 27708 (United States)

    2013-11-07

    The particle-particle random phase approximation (pp-RPA) provides an approximation to the correlation energy in density functional theory via the adiabatic connection [H. van Aggelen, Y. Yang, and W. Yang, Phys. Rev. A 88, 030501 (2013)]. It has virtually no delocalization error nor static correlation error for single-bond systems. However, with its formal O(N{sup 6}) scaling, the pp-RPA is computationally expensive. In this paper, we implement a spin-separated and spin-adapted pp-RPA algorithm, which reduces the computational cost by a substantial factor. We then perform benchmark tests on the G2/97 enthalpies of formation database, DBH24 reaction barrier database, and four test sets for non-bonded interactions (HB6/04, CT7/04, DI6/04, and WI9/04). For the G2/97 database, the pp-RPA gives a significantly smaller mean absolute error (8.3 kcal/mol) than the direct particle-hole RPA (ph-RPA) (22.7 kcal/mol). Furthermore, the error in the pp-RPA is nearly constant with the number of atoms in a molecule, while the error in the ph-RPA increases. For chemical reactions involving typical organic closed-shell molecules, pp- and ph-RPA both give accurate reaction energies. Similarly, both RPAs perform well for reaction barriers and nonbonded interactions. These results suggest that the pp-RPA gives reliable energies in chemical applications. The adiabatic connection formalism based on pairing matrix fluctuation is therefore expected to lead to widely applicable and accurate density functionals.

  3. Power functional theory for the dynamic test particle limit

    International Nuclear Information System (INIS)

    Brader, Joseph M; Schmidt, Matthias

    2015-01-01

    For classical Brownian systems both in and out of equilibrium we extend the power functional formalism of Schmidt and Brader (2013 J. Chem. Phys. 138 214101) to mixtures of different types of particles. We apply the framework to develop an exact dynamical test particle theory for the self and distinct parts of the van Hove function, which characterize tagged and collective particle motion. The memory functions that induce non-Markovian dynamics are related to functional derivatives of the excess (over ideal) free power dissipation functional. The method offers an alternative to the recently found nonequilibrium Ornstein–Zernike relation for dynamic pair correlation functions. (paper)

  4. Geodesics of electrically and magnetically charged test particles in the Reissner-Nordstroem space-time: Analytical solutions

    International Nuclear Information System (INIS)

    Grunau, Saskia; Kagramanova, Valeria

    2011-01-01

    We present the full set of analytical solutions of the geodesic equations of charged test particles in the Reissner-Nordstroem space-time in terms of the Weierstrass weierp, σ, and ζ elliptic functions. Based on the study of the polynomials in the θ and r equations, we characterize the motion of test particles and discuss their properties. The motion of charged test particles in the Reissner-Nordstroem space-time is compared with the motion of neutral test particles in the field of a gravitomagnetic monopole. Electrically or magnetically charged particles in the Reissner-Nordstroem space-time with magnetic or electric charges, respectively, move on cones similar to neutral test particles in the Taub-NUT space-times.

  5. Testing particle filters on convective scale dynamics

    Science.gov (United States)

    Haslehner, Mylene; Craig, George. C.; Janjic, Tijana

    2014-05-01

    Particle filters have been developed in recent years to deal with highly nonlinear dynamics and non Gaussian error statistics that also characterize data assimilation on convective scales. In this work we explore the use of the efficient particle filter (P.v. Leeuwen, 2011) for convective scale data assimilation application. The method is tested in idealized setting, on two stochastic models. The models were designed to reproduce some of the properties of convection, for example the rapid development and decay of convective clouds. The first model is a simple one-dimensional, discrete state birth-death model of clouds (Craig and Würsch, 2012). For this model, the efficient particle filter that includes nudging the variables shows significant improvement compared to Ensemble Kalman Filter and Sequential Importance Resampling (SIR) particle filter. The success of the combination of nudging and resampling, measured as RMS error with respect to the 'true state', is proportional to the nudging intensity. Significantly, even a very weak nudging intensity brings notable improvement over SIR. The second model is a modified version of a stochastic shallow water model (Würsch and Craig 2013), which contains more realistic dynamical characteristics of convective scale phenomena. Using the efficient particle filter and different combination of observations of the three field variables (wind, water 'height' and rain) allows the particle filter to be evaluated in comparison to a regime where only nudging is used. Sensitivity to the properties of the model error covariance is also considered. Finally, criteria are identified under which the efficient particle filter outperforms nudging alone. References: Craig, G. C. and M. Würsch, 2012: The impact of localization and observation averaging for convective-scale data assimilation in a simple stochastic model. Q. J. R. Meteorol. Soc.,139, 515-523. Van Leeuwen, P. J., 2011: Efficient non-linear data assimilation in geophysical

  6. Particle-particle correlations and lifetimes of composite nuclei: New tests for the evaporation model and for statistical equilibration

    International Nuclear Information System (INIS)

    DeYoung, P.A.; Gelderloos, C.J.; Kortering, D.; Sarafa, J.; Zienert, K.; Gordon, M.S.; Fineman, B.J.; Gilfoyle, G.P.; Lu, X.; McGrath, R.L.; de Castro Rizzo, D.M.; Alexander, J.M.; Auger, G.; Kox, S.; Vaz, L.C.; Beck, C.; Henderson, D.J.; Kovar, D.G.; Vineyard, M.F.; Department of Physics, State University of New York at Stony Brook, Stony Brook, New York 11794; Department of Chemistry, State University of New York at Stony Brook, Stony Brook, New York 11794; Argonne National Laboratory, Argonne, Illinois 60439)

    1990-01-01

    We present data for small-angle particle-particle correlations from the reactions 80, 140, 215, and 250 MeV 16 O+ 27 Al→p-p or p-d. The main features of these data are anticorrelations for small relative momenta (≤25 MeV/c) that strengthen with increasing bombarding energy. Statistical model calculations have been performed to predict the mean lifetimes for each step of evaporative decay, and then simulate the trajectories of the particle pairs and the resulting particle correlations. This simulation accounts very well for the trends of the data and can provide an important new test for the hypothesis of equilibration on which the model is built

  7. Scientists confirm delay in testing new CERN particle accelerator

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inswitzerland on Monday confirmed a delay in tests of a massive new particle accelerator." (1 page)

  8. Test Particle Energization and the Anisotropic Effects of Dynamical MHD Turbulence

    Science.gov (United States)

    González, C. A.; Dmitruk, P.; Mininni, P. D.; Matthaeus, W. H.

    2017-11-01

    In this paper, we analyze the effect of dynamical three-dimensional magnetohydrodynamic (MHD) turbulence on test particle acceleration and compare how this evolving system affects particle energization by current sheet interaction, as opposed to frozen-in-time fields. To do this, we analyze the ensemble particle acceleration for static electromagnetic fields extracted from direct numerical simulations of the MHD equations, and compare it with the dynamical fields. We show that a reduction in particle acceleration in the dynamical model results from particle trapping in field lines, which forces the particles to be advected by the flow and suppresses long exposures to the strong electric field gradients that take place between structures and generate (among other effects) an efficient particle acceleration in the static case. In addition, we analyze the effect of anisotropy caused by the mean magnetic field. It is well known that for sufficiently strong external fields, the system experiences a transition toward a two-dimensional flow. This causes an increment in the size of the coherent structures, resulting in a magnetized state of the particles and a reduction in particle energization.

  9. Physicists purchase materials testing machine in support of pioneering particle physics experiments

    CERN Multimedia

    Sharpe, Suzanne

    2007-01-01

    "The particle physics group at Liverpool University has purchased an LRXPlus singlecolumn materials testing machine from Lloyd Instruments, which will be used to help characterise the carbon-fibre support frames for detectors used for state-of-the-art particle physics experiments." (1 page)

  10. PIE on Safety-Tested Loose Particles from Irradiated Compact 4-4-2

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Gerczak, Tyler J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Morris, Robert Noel [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Baldwin, Charles A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Montgomery, Fred C. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2016-04-01

    Post-irradiation examination (PIE) is being performed in support of tristructural isotropic (TRISO) coated particle fuel development and qualification for High Temperature Gas-cooled Reactors (HTGRs). This work is sponsored by the Department of Energy Office of Nuclear Energy (DOE-NE) through the Advanced Reactor Technologies (ART) Office under the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program. The AGR-1 experiment was the first in a series of TRISO fuel irradiation tests initiated in 2006. The AGR-1 TRISO particles and fuel compacts were fabricated at Oak Ridge National Laboratory (ORNL) in 2006 using laboratory-scale equipment and irradiated for 3 years in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to demonstrate and evaluate fuel performance under HTGR irradiation conditions. Post-irradiation examination was performed at INL and ORNL to study how the fuel behaved during irradiation, and to test fuel performance during exposure to elevated temperatures at or above temperatures that could occur during a depressurized conduction cooldown event. This report summarizes safety testing and post-safety testing PIE conducted at ORNL on loose particles extracted from irradiated AGR-1 Compact 4-4-2.

  11. Particle Identification Studies with an ALICE Test TPC

    CERN Document Server

    Christiansen, P

    2007-01-01

    Using a test TPC, consisting of the ALICE TPC field cage prototype in combination with the final ALICE TPC readout and electronics, the energy loss distribution and resolution were measured for identified protons. The measurements were compared to theoretical calculations and good quantitative agreement was found when detector effects were taken into account. The implications for particle identification are discussed.

  12. Particle accelerators test cosmological theory

    International Nuclear Information System (INIS)

    Schramm, D.N.; Steigman, G.

    1988-01-01

    Over the past decade two subfields of science, cosmology and elementary-particle physics, have become married in a symbiotic relationship that has produced a number of exciting offspring. These offspring are beginning to yield insights on the creation of spacetime and matter at epochs as early as 10 to the minus 43 to 10 to the minus 35 second after the birth of the universe in the primordial explosion known as the big bang. Important clues to the nature of the big bang itself may even come from a theory currently under development, known as the ultimate theory of everything (T.E.O.). A T.E.O. would describe all the interactions among the fundamental particles in a single bold stroke. Now that cosmology ahs begun to make predictions about elementary-particle physics, it has become conceivable that those cosmological predictions could be checked with carefully controlled accelerator experiments. It has taken more than 10 years for accelerators to reach the point where they can do the appropriate experiments, but the experiments are now in fact in progress. The preliminary results confirm the predictions of cosmology. The cosmological prediction the authors have been concerned with pertains to setting limits on the number of fundamental particles of matter. It appears that there are 12 fundamental particles, as well as their corresponding antiparticles. Six of the fundamental particles are quarks. The other six are leptons. The 12 particles are grouped in three families, each family consisting of four members. Cosmology suggests there must be a finite number of families and, further limits the possible range of to small values: only three or at most four families exist. 7 figs

  13. Ultrafine particle emission characteristics of diesel engine by on-board and test bench measurement.

    Science.gov (United States)

    Huang, Cheng; Lou, Diming; Hu, Zhiyuan; Tan, Piqiang; Yao, Di; Hu, Wei; Li, Peng; Ren, Jin; Chen, Changhong

    2012-01-01

    This study investigated the emission characteristics of ultrafine particles based on test bench and on-board measurements. The bench test results showed the ultrafine particle number concentration of the diesel engine to be in the range of (0.56-8.35) x 10(8) cm(-3). The on-board measurement results illustrated that the ultrafine particles were strongly correlated with changes in real-world driving cycles. The particle number concentration was down to 2.0 x 10(6) cm(-3) and 2.7 x 10(7) cm(-3) under decelerating and idling operations and as high as 5.0 x 10(8) cm(-3) under accelerating operation. It was also indicated that the particle number measured by the two methods increased with the growth of engine load at each engine speed in both cases. The particle number presented a "U" shaped distribution with changing speed at high engine load conditions, which implies that the particle number will reach its lowest level at medium engine speeds. The particle sizes of both measurements showed single mode distributions. The peak of particle size was located at about 50-80 nm in the accumulation mode particle range. Nucleation mode particles will significantly increase at low engine load operations like idling and decelerating caused by the high concentration of unburned organic compounds.

  14. Behaviour of HTGR coated fuel particles at high-temperature tests

    International Nuclear Information System (INIS)

    Chernikov, A.S.; Lyutikov, R.A.; Kurbakov, S.D.; Repnikov, V.M.; Khromonozhkin, V.V.; Soloviyov, G.I.

    1990-01-01

    At the temperature range 1200-2600 deg. C prereactor tests of TRISO fuel particles on the base of UO 2 , UC x O y and UO 2 +2Al 2 O 3 . SiO 2 kernels, and also fuel particle models with ZrC kernels were performed. Isothermal annealings carried out at temperatures of 1400-2600 deg. C, thermogradient ones at 1200-2200 deg. C (Δ T = 200-1200 deg. C/cm). It is shown that at heating to 2200 deg. C integrity of fuel particles is limited by different thermal expansion of PyC and SiC coatings, and also by thermal dissociation of SiC. At higher temperatures the failure is caused by development of high pressures within weakened fuel particles. It is found that uranium migration from alloyed fuel (UC x O y , UO 2 +2Al 2 O 3 .SiO 2 ) in the process of annealing is higher than that from UO 2 . (author)

  15. Coupling of linearized gravity to nonrelativistic test particles: Dynamics in the general laboratory frame

    International Nuclear Information System (INIS)

    Speliotopoulos, A.D.; Chiao, Raymond Y.

    2004-01-01

    The coupling of gravity to matter is explored in the linearized gravity limit. The usual derivation of gravity-matter couplings within the quantum-field-theoretic framework is reviewed. A number of inconsistencies between this derivation of the couplings and the known results of tidal effects on test particles according to classical general relativity are pointed out. As a step towards resolving these inconsistencies, a general laboratory frame fixed on the worldline of an observer is constructed. In this frame, the dynamics of nonrelativistic test particles in the linearized gravity limit is studied, and their Hamiltonian dynamics is derived. It is shown that for stationary metrics this Hamiltonian reduces to the usual Hamiltonian for nonrelativistic particles undergoing geodesic motion. For nonstationary metrics with long-wavelength gravitational waves present (GWs), it reduces to the Hamiltonian for a nonrelativistic particle undergoing geodesic deviation motion. Arbitrary-wavelength GWs couple to the test particle through a vector-potential-like field N a , the net result of the tidal forces that the GW induces in the system, namely, a local velocity field on the system induced by tidal effects, as seen by an observer in the general laboratory frame. Effective electric and magnetic fields, which are related to the electric and magnetic parts of the Weyl tensor, are constructed from N a that obey equations of the same form as Maxwell's equations. A gedankin gravitational Aharonov-Bohm-type experiment using N a to measure the interference of quantum test particles is presented

  16. Spinning test particles in the field of a black hole

    Energy Technology Data Exchange (ETDEWEB)

    Tod, K P; de Felice, F [Padua Univ. (Italy); Calvani, M [Padua Univ. (Italy). Istituto di Astronomia

    1976-08-11

    It is studied the motion of spinning test bodies in the gravitational field of a rotating black hole, confining the examination of the pole-dipole approximation and of the special case of motion in the equatorial plane with the spin vector perpendicular to it. The study also provides the locus of the turning points for the equatorial orbits and also the exact limits of validity of the pole-dipole approximation for any given set of particle parameters. The innermost stable circular orbits are studied in details, and it is found that opposite spinning accreting particles are separated by the gravitational field of the black hole and that the fraction of energy ''at infinity'' which can be extracted when the particle spin is opposite to that of the black hole can be as high as 100%.

  17. Airborne Wear Particles Emissions fromCommercial Disc Brake Materials– Passenger Car Field Test

    OpenAIRE

    Wahlström, Jens; Olofsson, Ulf; Jansson, Anders; Olander, Lars

    2008-01-01

    Most modern passenger cars have disc brakes on the front wheels, which unlike drum brakes are not sealed off to the ambient air. During braking, there is wear to both the rotor and the pads. This wear process generates particles, which may become airborne. In field tests it is difficult to distinguish these particles from others in the surrounding environment. It may be preferable to use laboratory test stands where the cleanness of the surrounding air can be controlled. The validity of these...

  18. Gas Generation from K East Basin Sludges and Irradiated Metallic Uranium Fuel Particles Series III Testing

    International Nuclear Information System (INIS)

    Schmidt, Andrew J.; Delegard, Calvin H.; Bryan, Samuel A.; Elmore, Monte R.; Sell, Rachel L.; Silvers, Kurt L.; Gano, Susan R.; Thornton, Brenda M.

    2003-01-01

    The path forward for managing of Hanford K Basin sludge calls for it to be packaged, shipped, and stored at T Plant until final processing at a future date. An important consideration for the design and cost of retrieval, transportation, and storage systems is the potential for heat and gas generation through oxidation reactions between uranium metal and water. This report, the third in a series (Series III), describes work performed at the Pacific Northwest National Laboratory (PNNL) to assess corrosion and gas generation from irradiated metallic uranium particles (fuel particles) with and without K Basin sludge addition. The testing described in this report consisted of 12 tests. In 10 of the tests, 4.3 to 26.4 g of fuel particles of selected size distribution were placed into 60- or 800-ml reaction vessels with 0 to 100 g settled sludge. In another test, a single 3.72-g fuel fragment (i.e., 7150-mm particle) was placed in a 60 ml reaction vessel with no added sludge. The twelfth test contained only sludge. The fuel particles were prepared by crushing archived coupons (samples) from an irradiated metallic uranium fuel element. After loading the sludge materials (whether fuel particles, mixtures of fuel particles and sludge, or sludge-only) into reaction vessels, the solids were covered with an excess of K Basin water, the vessels closed and connected to a gas measurement manifold, and the vessels back-flushed with inert neon cover gas. The vessels were then heated to a constant temperature. The gas pressures and temperatures were monitored continuously from the times the vessels were purged. Gas samples were collected at various times during the tests, and the samples analyzed by mass spectrometry. Data on the reaction rates of uranium metal fuel particles with water as a function of temperature and particle size were generated. The data were compared with published studies on metallic uranium corrosion kinetics. The effects of an intimate overlying sludge layer

  19. Review of Bose-Fermi and ''Supersymmetry'' models; problems in particle transfer tests

    International Nuclear Information System (INIS)

    Vergnes, M.

    1986-01-01

    The first case suggested for a supersymmetry in nuclei was that of a j = 3/2 particle coupled to an 0(6) core. A more recent and elaborate scheme is the ''multi-j'' supersymmetry, describing the coupling of a particle in more than just one orbital, with the three possible cores of the interacting boson model. A general survey of the particle transfer tests of these different models is presented and the results summarized. A comparison of IBFM-2 calculations with experimental data is discussed, as well as results of sum rules analysis. Present and future tests concerning extensions of the above mentioned models, particularly to odd-odd nuclei, are briefly indicated. It appears necessary to clearly determine if the origin of the difficulties outlined for transfer reactions indeed lies -as often suggested- in the simplified form of the transfer operator used in deriving the selection rules, and not in the models themselves

  20. Testing of alkaline and enzymatic hydrolysis pretreatments for fat particles in slaughterhouse wastewater.

    Science.gov (United States)

    Masse, L; Kennedy, K J; Chou, S

    2001-04-01

    Four pretreatments to hydrolyse and/or reduce the size of fat particles in slaughterhouse wastewater (SHW) were tested: sodium hydroxide and three lipases of plant, bacterial and animal (pancreatic) origin. Hydrolysing agents and SHW containing between 2.5 and 3 g/l of fat particles were mixed at room temperature for 4 h. Additions of 5-400 meq NaOH/l did not increase soluble COD (SCOD) in SHW, but the average particle size was reduced to 73% +/- 7% of the initial average particle size (D(in)) at NaOH concentrations ranging from 150 to 300 meq/l. Pretreatment with pancreatic lipase PL-250 reduced the average particle size to a maximum of 60% +/- 3% of D(in). As D(in) was decreased from 359 to 68 microns, the enzyme concentration required to obtain the maximum particle size reduction increased from 200 to 1000 mg/l. A 4-h pretreatment with PL-250 also increased the free long-chain fatty acid (LCFA) concentration to a maximum of 15.5 mg/l, indicating some solubilization of the pork fat particles in SHW. SCOD was not significantly increased by the pretreatment, but SCOD was not found to be a good indicator of enzymatic lipolysis because of enzyme adsorption on the fat particle surface. Pancreatic lipase appeared more efficient with beef fat than pork fat, possibly because beef fat contains less polyunsaturated fatty acids than pork fat. The bacterial lipase LG-1000 was also efficient in reducing average fat particle size, but high doses (> 1000 mg/l) were required to obtain a significant reduction after 4 h of pretreatment. SCOD was not increased by pretreatment with LG-1000. No particle size reduction or changes in SCOD were noted after 4 h of pretreatment with the plant lipase EcoSystem Plus. It was concluded that PL-250 was the best pretreatment to hydrolyse fat particles in SHW. However, its impact on the efficiency of a downstream anaerobic digestion process remains to be tested.

  1. Eddy Current, Magnetic Particle and Hardness Testing, Aviation Quality Control (Advanced): 9227.04.

    Science.gov (United States)

    Dade County Public Schools, Miami, FL.

    This unit of instruction includes the principles of eddy current, magnetic particle and hardness testing; standards used for analyzing test results; techniques of operating equipment; interpretation of indications; advantages and limitations of these methods of testing; care and calibration of equipment; and safety and work precautions. Motion…

  2. Substorm effects in MHD and test particle simulations of magnetotail dynamics

    International Nuclear Information System (INIS)

    Birn, J.; Hesse, M.

    1998-01-01

    Recent magnetohydrodynamic simulations demonstrate that a global tail instability, initiated by localized breakdown of MHD, can cause plasmoid formation and ejection as well as dipolarization and the current diversion of the substorm current wedge. The connection between the reconnection process and the current wedge signatures is provided by earthward flow from the reconnection site. Its braking and diversion in the inner magnetosphere causes dipolarization and the magnetic field distortions of the current wedge. The authors demonstrate the characteristic properties of this process and the current systems involved. The strong localized electric field associated with the flow burst and the dipolarization is also the cause of particle acceleration and energetic particle injections. Test particle simulations of orbits in the MHD fields yield results that are quite consistent with observed injection signatures

  3. The limits of testing particle-mediated oxidative stress in vitro in predicting diverse pathologies; relevance for testing of nanoparticles

    Directory of Open Access Journals (Sweden)

    Gulumian Mary

    2009-04-01

    Full Text Available Abstract In vitro studies with particles are a major staple of particle toxicology, generally used to investigate mechanisms and better understand the molecular events underlying cellular effects. However, there is ethical and financial pressure in nanotoxicology, the new sub-specialty of particle toxicology, to avoid using animals. Therefore an increasing amount of studies are being published using in vitro approaches and such studies require careful interpretation. We point out here that 3 different conventional pathogenic particle types, PM10, asbestos and quartz, which cause diverse pathological effects, have been reported to cause very similar oxidative stress effects in cells in culture. We discuss the likely explanation and implications of this apparent paradox, and its relevance for testing in nanotoxicology.

  4. Correlation between the median particle size of chewed frankfurter sausage and almonds during masticatory performance test.

    Science.gov (United States)

    Sumonsiri, P; Thongudomporn, U; Paphangkorakit, J

    2018-04-27

    The correlation between chewing and gastric function is best reflected when the same food type is used during both tests. We proposed frankfurter sausage as test food for masticatory performance as it can also be used in gastric emptying test. The suitability of frankfurter sausage to determine masticatory performance, however, has never been examined. To examine the correlations between the median particle size of frankfurter sausage and almonds (as standard test food) after different numbers of chewing cycles. Twenty-seven subjects performed masticatory performance tests by chewing 2 types of test foods, that is, a piece of almond or 5-g frankfurter sausage cubes placed in a sealed latex bag, for 5 and 15 chewing cycles. For each individual, right and left sides were tested separately. Chewed samples obtained from both sides were pooled. Median particle sizes were determined using a multiple sieving method. Spearman's rank correlation was used to examine any correlation between median particle sizes of the 2 test foods after 5 and 15 cycles. Median particle sizes after 5 and 15 cycles were 2.04 ± 0.87 and 0.95 ± 0.58 mm for almonds and 4.16 ± 0.19 and 3.73 ± 0.25 mm for frankfurter sausage, respectively. Significant correlations were observed between the median particle size of chewed frankfurter sausage after 15 cycles and that of chewed almonds after 5 and 15 cycles (r = .76, P < .01 and r = .52, P = .01, respectively). Frankfurter sausage chewed for 15 cycles may be suitable for the determination of masticatory performance in conjunction with gastric emptying test. © 2018 John Wiley & Sons Ltd.

  5. Time-dependent diffusive acceleration of test particles at shocks

    Energy Technology Data Exchange (ETDEWEB)

    Drury, L.O' C. (Dublin Inst. for Advanced Studies (Ireland))

    1991-07-15

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author).

  6. Time-dependent diffusive acceleration of test particles at shocks

    International Nuclear Information System (INIS)

    Drury, L.O'C.

    1991-01-01

    The acceleration of test particles at a steady plane non-relativistic shock is considered. Analytic expressions are found for the mean and the variance of the acceleration time distribution in the case where the diffusion coefficient has an arbitrary dependence on position and momentum. These expressions are used as the basis for an approximation scheme which is shown, by comparison with numerical solutions, to give an excellent representation of the time-dependent spectrum. (author)

  7. Test particle method for incorporation of the kinetic effects into the envelope simulations of Raman backscattering

    International Nuclear Information System (INIS)

    Hur, Min Sup; Suk, Hyyong

    2007-01-01

    A new test particle method is presented for self-consistent incorporation of the kinetic effects into the fluid three-wave model. One of the most important kinetic effects is the electron trapping and it has been found that the trapping affects significantly the behavior of Raman backscatter and Raman backward laser amplification. The conventional fluid three-wave model cannot reproduce the kinetic simulations in the trapping regime. The test particle scheme utilizes the same equations for the laser evolution as in the three-wave model. However, the plasma wave is treated by the envelope-kinetic equation, which consists of envelope evolution and the kinetic term. The core of the new scheme is employing test particles to compute the kinetic term self-consistently. The benchmarking results against the averaged particle-in-cell (aPIC) code show excellent agreements, and the computation speed gain over the aPIC is from 2 to 20 depending on parameters

  8. Particle-size dependence of immersion freezing: Investigation of INUIT test aerosol particles with freely suspended water drops.

    Science.gov (United States)

    Diehl, Karoline; Debertshäuser, Michael; Eppers, Oliver; Jantsch, Evelyn; Mitra, Subir K.

    2014-05-01

    One goal of the research group INUIT (Ice Nuclei research UnIT) is to investigate the efficiencies of several test ice nuclei under comparable conditions but with different experimental techniques. In the present studies, two methods are used: the Mainz vertical wind tunnel and an acoustic levitator placed inside a cold chamber. In both cases drops are freely levitated, either at their terminal velocity in the wind tunnel updraft or around the nodes of a standing ultrasonic wave in the acoustic levitator. Thus, heat transfer conditions are well approximated, and wall contact effects on freezing as well as electrical charges of the drops are avoided. Drop radii are 370 μm and 1 mm, respectively. In the wind tunnel, drops are investigated at constant temperatures within a certain time period and the onset of freezing is observed directly. In the acoustic levitator, the drop temperature decreases during the experiments and is measured by an in-situ calibrated Infrared thermometer. The onset of freezing is indicated by a rapid rise of the drop surface temperature because of the release of latent heat. Investigated test ice nuclei are Snomax® as a proxy of biological particles and illite NX as well as K-feldspar as represents of mineral dust. The particle concentrations are 1 × 10-12 to 3 × 10-6 g Snomax® per drop and 5 × 10-9 to 5 × 10-5 g mineral dust per drop. Freezing temperatures are between -2 and -18° C in case of Snomax® and between -14 and -26° C in case of mineral dust. The lower the particle masses per drop the lower are the freezing temperatures. For similar particle concentrations in the drops, the median freezing temperatures determined by the two techniques agree well within the measurement errors. With the knowledge of the specific particle surface area of the mineral dusts, the results are interpreted also in terms of particle surface area per drop. Results from the wind tunnel experiments which are performed at constant temperatures indicate

  9. Dynamics of relative motion of test particles in general relativity

    International Nuclear Information System (INIS)

    Bazanski, S.L.

    1977-01-01

    Several variational principles which lead to the first and the second geodesic deviation equations, recently formulated by the author and used for the description of the relative motion of test particles in general relativity are presented. Relations between these principles are investigated and exhibited. The Hamilton-Jacobi equation is also studied for these generalized deviations and the conservation laws appearing here are discussed

  10. Effects of particle size and heating time on thiobarbituric acid (TBA) test of soybean powder.

    Science.gov (United States)

    Lee, Youn-Ju; Yoon, Won-Byong

    2013-06-01

    Effects of particle size and heating time during TBA test on the thiobarbituric acid reactive substance (TBARS) of soybean (Glycine Max) powder were studied. Effects of processing variables involved in the pulverization of soybean, such as the temperature of soybean powder, the oxygen level in the vessel, and the pulverisation time, were investigated. The temperature of the soybean powder and the oxygen level had no significant influence on the TBARS (pTBA test significantly affected the TBARS. Change of TBARS during heating was well described by the fractional conversion first order kinetics model. A diffusion model was introduced to quantify the effect of particle size on TBARS. The major finding of this study was that the TBA test to estimate the level of the lipid oxidation directly from powders should consider the heating time and the mean particle sizes of the sample. Copyright © 2012 Elsevier Ltd. All rights reserved.

  11. Natural tracer test simulation by stochastic particle tracking method

    International Nuclear Information System (INIS)

    Ackerer, P.; Mose, R.; Semra, K.

    1990-01-01

    Stochastic particle tracking methods are well adapted to 3D transport simulations where discretization requirements of other methods usually cannot be satisfied. They do need a very accurate approximation of the velocity field. The described code is based on the mixed hybrid finite element method (MHFEM) to calculated the piezometric and velocity field. The random-walk method is used to simulate mass transport. The main advantages of the MHFEM over FD or FE are the simultaneous calculation of pressure and velocity, which are considered as unknowns; the possibility of interpolating velocities everywhere; and the continuity of the normal component of the velocity vector from one element to another. For these reasons, the MHFEM is well adapted for particle tracking methods. After a general description of the numerical methods, the model is used to simulate the observations made during the Twin Lake Tracer Test in 1983. A good match is found between observed and simulated heads and concentrations. (Author) (12 refs., 4 figs.)

  12. Application of charged particle activation for testing machine part wear

    International Nuclear Information System (INIS)

    Kosimova, M.; Tendera, P.

    1985-01-01

    The results of application of the charge particle activation method to investigate machine part wear are presented. Study of radionuclide activity and yield has been carried out at the U-120M isochronous cyclotron by means of the method of iron foil piles from 20 to 100 μm in thick. Protons and deuterons have been used. Wear measurement is based on determination of wear particle activity in a butyric medium. An example of the results of a bench test of activated piston rings and cylinder liner of the engine for trucks is given. The method of surface activation is shown to be acceptable for studying machine part wear under the regular service conditions, especially on the stage of the primary investigations and development, when sampling structural materials and estimating different lubricating oil applicability

  13. Accurate particle speed prediction by improved particle speed measurement and 3-dimensional particle size and shape characterization technique

    DEFF Research Database (Denmark)

    Cernuschi, Federico; Rothleitner, Christian; Clausen, Sønnik

    2017-01-01

    Accurate particle mass and velocity measurement is needed for interpreting test results in erosion tests of materials and coatings. The impact and damage of a surface is influenced by the kinetic energy of a particle, i.e. particle mass and velocity. Particle mass is usually determined with optic...

  14. Temperature of loose coated particles in irradiation tests

    International Nuclear Information System (INIS)

    Conlin, J.A.

    1975-04-01

    An analysis is presented of the temperature of a monolayer bed of loose High-Temperature Gas-Cooled Reactor (HTGR) type fissioning fuel particles in an annular cavity. Both conduction and radiant heat transfer are taken into account, and the effect of particle contact with the annular cavity surfaces is evaluated. Charts are included for the determination of the maximum surface temperature of the particle coating for any size particle or power generation rate in a fuel bed of this type. The charts are intended for the design and evaluation of irradiation experiments on loose beds of coated fuel particles of the type used in HTGRs. Included in an Appendix is a method for estimating the temperature of a particle in circular hole. (U.S.)

  15. Charged NUT field : [Part] I. Motion of test particles and [Part] II. Cosmic censorship

    International Nuclear Information System (INIS)

    Krori, K.D.

    1981-01-01

    Some properties of the charged NUT field are studied. In the first part of the paper, some general aspects of the charged NUT field have been investigated using uncharged and charged particles. The behaviour of the particles near the singularity has also been considered. In the second part of the paper, the charged NUT sources in the context of cosmic censorship hypothesis are studied. Motion of charged particles in the equatorial plane and along the axis is considered. From this investigation the interesting result is discovered that by such a bombardment of charged test particles, the existing event horizons cannot be destroyed but, in contrast to the Reissner-Nordstrom field, naked singularities do not get enveloped by event horizons. (author)

  16. Testing and assessment of a large BGO detector for beach monitoring of radioactive particles

    International Nuclear Information System (INIS)

    Graaf, E.R. van der; Rigollet, C.; Maleka, P.P.; Jones, D.G.

    2007-01-01

    The Beach Monitoring Steering Group (BMSG) was set up by UKAEA to explore whether improved systems for beach monitoring of radioactive particles are available. The BMSG commissioned the British Geological Survey (BGS) and the Nuclear Geophysics Division of the Kernfysisch Versneller Instituut (KVI/NGD), and other companies, to test their most sensitive system. This paper presents the results of trials in a specially created test facility at UKAEA Harwell with a large BGO detector. The detector's size and weight mean that it would be suitable for vehicle deployment but would be too large and heavy to carry in areas that could not be accessed by a vehicle. However, it would be possible to use the same methodology that is described here with a smaller detector capable of being carried in a backpack, albeit with reduced sensitivity for particle detection. The approach that we present is also applicable, with modifications, to the detection of offshore particles using a towed seabed detector

  17. Research and systematization of 'hot' particles in the Semipalatinsk nuclear test site soils - methodology and first results

    International Nuclear Information System (INIS)

    Gorlachev, I.D.; Knyazev, B.B.; Kvochkina, T.N.; Lukashenko, S.N.

    2005-01-01

    Full text: Sources of soil activity in Semipalatinsk Nuclear Test Site (SNTS) could be both 'hot' particles dimensions from tens microns to units millimeters and sub-microns particles determining a matrix activity of soil samples. The fractionating of radionuclides and formation of 'hot' particles radionuclide composition arose from temperature changes and complicated nuclear-physical and thermodynamics processes occurring in a fire ball and cloud of nuclear explosion. Knowledge of 'hot' particles physical-chemical properties is needed for evaluation of radioactive products migration in the environment and danger level of the people external and internal exposure. Moreover, minute information about the structure and compound of 'radioactive' particles can be useful for specification of processes occurring in a fiery sphere when conducting explosions of different phylum and also for specification of radioactive fallout forming mechanism. The main polluted spots of SNTS could be divided into the four the species depending on nuclear explosion phylum. Species of radionuclide and their distribution for the different nuclear explosions are able to differ considerably. Therefore, several most typical areas for the each phylum test were selected and twenty soil samples were collected to reveal their radionuclide pollution peculiarities. Collected soil samples were separated into the five granulometric fractions: 1 mm - 2 mm, 0.5 mm - 1 mm. 0.28 mm-0.5 mm, 0.112 mm - 0.28 mm and 1 mm), 210 'hot' particles of second fraction (1>f>0.5 mm) and 154 'hot' particles of third fraction (0.5>f>0.28 mm) have been selection from the twelve SNTS soil samples by the compelled fission and visual identification methods. Main sources of soil samples and 'hot' particles activities are 239+240 Pu, 241 Am, 137 Cs and 152 Eu isotopes.In addition to the described works the special sampling of large 'hot' particles (dimension more than 2 mm) was carried out in areas of the ground and air tests

  18. Irradiation test OF-2: high-temperature irradiation behavior of LASL-made fuel rods and LASL-made coated particles

    International Nuclear Information System (INIS)

    Wagner, P.; Reiswig, R.D.; Hollabaugh, C.M.; White, R.W.; O'Rourke, J.A.; Davidson, K.V.; Schell, D.H.

    1977-10-01

    Three LASL-made, substoichiometric ZrC-coated particles with inert kernels, and two high-density molded graphite fuel rods that contained LASL-made, ZrC-coated fissile particles were irradiated in the Oak Ridge Research Reactor test OF-2. The severest test conditions were 8.36 x 10 21 nvt (E greater than 0.18 MeV) at 1350 0 C. The graphite matrix showed no effect of the irradiation. There was no interaction between the matrix and any of the particle coats. The loose ZrC coated particles with inert kernels showed no irradiation effects. The graded ZrC-C coats on the fissile particles were cracked. It is postulated that the cracking is associated with the low LTI deposition rate and is not related to the ZrC

  19. Numerical Test of Different Approximations Used in the Transport Theory of Energetic Particles

    Science.gov (United States)

    Qin, G.; Shalchi, A.

    2016-05-01

    Recently developed theories for perpendicular diffusion work remarkably well. The diffusion coefficients they provide agree with test-particle simulations performed for different turbulence setups ranging from slab and slab-like models to two-dimensional and noisy reduced MHD turbulence. However, such theories are still based on different analytical approximations. In the current paper we use a test-particle code to explore the different approximations used in diffusion theory. We benchmark different guiding center approximations, simplifications of higher-order correlations, and the Taylor-Green-Kubo formula. We demonstrate that guiding center approximations work very well as long as the particle's unperturbed Larmor radius is smaller than the perpendicular correlation length of the turbulence. Furthermore, the Taylor-Green-Kubo formula and the definition of perpendicular diffusion coefficients via mean square displacements provide the same results. The only approximation that was used in the past in nonlinear diffusion theory that fails is to replace fourth-order correlations by a product of two second-order correlation functions. In more advanced nonlinear theories, however, this type of approximation is no longer used. Therefore, we confirm the validity of modern diffusion theories as a result of the work presented in the current paper.

  20. Summary test results of the particle-beam diagnostics for the Advanced Photon Source (APS) subsystems

    International Nuclear Information System (INIS)

    Lumpkin, A.; Wang, X.; Sellyey, W.; Patterson, D.; Kahana, E.

    1994-01-01

    During the first half of 1994, a number of the diagnostic systems for measurement of the charged-particle beam parameters throughout the subsystems of the Advanced Photon Source (APS) have been installed and tested. The particle beams eventually will involve 450-MeV to 7-GeV positrons and with different pulse formats. The first test and commissionin results for beam profiles, beam position monitors, loss rate monitors, current monitors, and synchrotron radiation photon monitors hve been obtained using 200- to 350-MeV electron beams injected into the subsystems. Data presented are principally from the transport lines and the positron accumulator ring

  1. Tests of the particle physics-physical cosmology interface

    International Nuclear Information System (INIS)

    Schramm, D.N.

    1993-01-01

    Three interrelated interfaces of particle physics and physical cosmology are discussed: (1) inflation and other phase transitions; (2) Big Bang Nucleosynthesis (and also the quark-hadron transition); and (3) structure formation (including dark matter). Recent observations that affect each of these topics are discussed. Topic number 1 is shown to be consistent with the COBE observations but not proven and it may be having problems with some age-expansion data. Topic number 2 has now been well-tested and is an established ''pillar'' of the Big Bang. Topic number 3 is the prime arena of current physical cosmological activity. Experiments to resolve the current exciting, but still ambiguous, situation following the COBE results are discussed

  2. A test particle motion in the Kerr field with fluctuating perturbations

    International Nuclear Information System (INIS)

    Zhuk, I.T.; Piragas, K.A.

    1982-01-01

    Motion of a stochastic test particle in the Kerr black hole field in the approximation of Brown interaction is considered. Probability distribution of orbit position by the latitude angle is revealed, bifurcation values of their parameters are determined. Fluctuating instability of orbits characteristic of critical modes of motion is investigated, properties of some statistical characteristics of the system are identified

  3. Introduction to the Latest Version of the Test-Particle Monte Carlo Code Molflow+

    CERN Document Server

    Ady, M

    2014-01-01

    The Test-Particle Monte Carlo code Molflow+ is getting more and more attention from the scientific community needing detailed 3D calculations of vacuum in the molecular flow regime mainly, but not limited to, the particle accelerator field. Substantial changes, bug fixes, geometry-editing and modelling features, and computational speed improvements have been made to the code in the last couple of years. This paper will outline some of these new features, and show examples of applications to the design and analysis of vacuum systems at CERN and elsewhere.

  4. Fission product retention in TRISO coated UO2 particle fuels subjected to HTR simulated core heating tests

    International Nuclear Information System (INIS)

    Baldwin, C.A.; Kania, M.J.

    1991-01-01

    Results of the examination and analysis of 25,730 individual microspheres from spherical fuel elements HFR-K3/1 and HFR-K3/3 are reported. The parent spheres were irradiated in excess of end-of-life exposure and subsequently subjected to simulated core heating tests in a special high-temperature furnace at Forschungszentrum, Juelich, GmbH (KFA). Following the heating tests, the spheres were electrolytically deconsolidated to obtain unbounded fuel particles for Irradiated Microsphere Gamma Analyzer (IMGA) analysis. For sphere HFR-K3/1, which was heated for 500 h at 1600 deg. C, only four particles were identified as having released fission products. The remaining particles from the sphere showed no statistical evidence of fission product release. Scanning Electron Microscopy (SEM) examination showed that three of the defect particles had large sections of the TRISO coating missing, while the fourth appeared normal. For sphere HFR-K3/3, which was heated for 100 h at 1800 deg. C, the IMGA data revealed that fission product release (cesium) from individual particles was significant and that there was large particle-to-particle variation in retention capabilities. Individual particle release (cesium) averaged ten times the KFA-measured integral spherical fuel element release value. In addition, the bimodal distribution of the individual particle data indicated that two distinct modes of failure at fuel temperatures of 1800 deg. C and above may exist. (author). 6 refs, 6 figs, 4 tabs

  5. Fission product retention in TRISCO coated UO2 particle fuels subjected to HTR simulated core heating tests

    International Nuclear Information System (INIS)

    Baldwin, C.A.; Kania, M.J.

    1990-11-01

    Results of the examination and analysis of 25,730 individual microspheres from spherical fuel elements HFR-K3/1 and HFR-K3/3 are reported. The parent spheres were irradiated in excess of end-of-life exposure and subsequently subjected to simulated core heating tests in a special high-temperature furnace at Forschungszentrum, Juelich, GmbH (KFA). Following the heating tests, the spheres were electrolytically deconsolidated to obtain unbonded fuel particles for Irradiated Microsphere Gamma Analyzer (IMGA) analysis. For sphere HFR-K3/1, which was heated for 500 h at 1600 degree C, only four particles were identified as having released fission products. The remaining particles from the sphere showed no statistical evidence of fission product release. Scanning Electron Microscopy (SEM) examination showed that three of the defect particles had large sections of the TRISO coating missing, while the fourth appeared normal. For sphere HFR-K3/3, which was heated for 100 h at 1800 degree C, the IMGA data revealed that fission product release (cesium) from individual particles was significant and that there was large particle-to-particle variation in retention capabilities. Individual particle release (cesium) averaged ten times the KFA-measured integral spherical fuel element release value. In addition, the bimodal distribution of the individual particle data indicated that two distinct modes of failure at fuel temperatures of 1800 degree C and above may exist. 6 refs., 6 figs., 4 tabs

  6. Gravitational perturbation of the BTZ black hole induced by test particles and weak cosmic censorship in AdS spacetime

    International Nuclear Information System (INIS)

    Rocha, Jorge V.; Cardoso, Vitor

    2011-01-01

    We analyze the gravitational perturbations induced by particles falling into a three dimensional, asymptotically AdS black hole geometry. More specifically, we solve the linearized perturbation equations obtained from the geodesic motion of a ringlike distribution of test particles in the BTZ background. This setup ensures that the U(1) symmetry of the background is preserved. The nonasymptotic flatness of the background raises difficulties in attributing the significance of energy and angular momentum to the conserved quantities of the test particles. This issue is well known but, to the best of our knowledge, has never been addressed in the literature. We confirm that the naive expressions for energy and angular momentum are the correct definitions. Finally, we put an asymptotically AdS version of the weak cosmic censorship to a test: by attempting to overspin the BTZ black hole with test particles it is found that the black hole cannot be spun-up past its extremal limit.

  7. Laser-accelerated particle beams for stress testing of materials.

    Science.gov (United States)

    Barberio, M; Scisciò, M; Vallières, S; Cardelli, F; Chen, S N; Famulari, G; Gangolf, T; Revet, G; Schiavi, A; Senzacqua, M; Antici, P

    2018-01-25

    Laser-driven particle acceleration, obtained by irradiation of a solid target using an ultra-intense (I > 10 18  W/cm 2 ) short-pulse (duration testing materials and are particularly suited for identifying materials to be used in harsh conditions. We show that these laser-generated protons can produce, in a very short time scale, a strong mechanical and thermal damage, that, given the short irradiation time, does not allow for recovery of the material. We confirm this by analyzing changes in the mechanical, optical, electrical, and morphological properties of five materials of interest to be used in harsh conditions.

  8. Endovascular Device Testing with Particle Image Velocimetry Enhances Undergraduate Biomedical Engineering Education

    Science.gov (United States)

    Nair, Priya; Ankeny, Casey J.; Ryan, Justin; Okcay, Murat; Frakes, David H.

    2016-01-01

    We investigated the use of a new system, HemoFlow™, which utilizes state of the art technologies such as particle image velocimetry to test endovascular devices as part of an undergraduate biomedical engineering curriculum. Students deployed an endovascular stent into an anatomical model of a cerebral aneurysm and measured intra-aneurysmal flow…

  9. Particle dispersing system and method for testing semiconductor manufacturing equipment

    Science.gov (United States)

    Chandrachood, Madhavi; Ghanayem, Steve G.; Cantwell, Nancy; Rader, Daniel J.; Geller, Anthony S.

    1998-01-01

    The system and method prepare a gas stream comprising particles at a known concentration using a particle disperser for moving particles from a reservoir of particles into a stream of flowing carrier gas. The electrostatic charges on the particles entrained in the carrier gas are then neutralized or otherwise altered, and the resulting particle-laden gas stream is then diluted to provide an acceptable particle concentration. The diluted gas stream is then split into a calibration stream and the desired output stream. The particles in the calibration stream are detected to provide an indication of the actual size distribution and concentration of particles in the output stream that is supplied to a process chamber being analyzed. Particles flowing out of the process chamber within a vacuum pumping system are detected, and the output particle size distribution and concentration are compared with the particle size distribution and concentration of the calibration stream in order to determine the particle transport characteristics of a process chamber, or to determine the number of particles lodged in the process chamber as a function of manufacturing process parameters such as pressure, flowrate, temperature, process chamber geometry, particle size, particle charge, and gas composition.

  10. Bacterial magnetic particles improve testes-mediated transgene efficiency in mice.

    Science.gov (United States)

    Wang, Chao; Sun, Guanghong; Wang, Ye; Kong, Nana; Chi, Yafei; Yang, Leilei; Xin, Qiliang; Teng, Zhen; Wang, Xu; Wen, Yujun; Li, Ying; Xia, Guoliang

    2017-11-01

    Nano-scaled materials have been proved to be ideal DNA carriers for transgene. Bacterial magnetic particles (BMPs) help to reduce the toxicity of polyethylenimine (PEI), an efficient gene-transferring agent, and assist tissue transgene ex vivo. Here, the effectiveness of the BMP-PEI complex-conjugated foreign DNAs (BPDs) in promoting testes-mediated gene transfer (TMGT) in mouse was compared with that of liposome-conjugated foreign DNAs. The results proved that through testes injection, the clusters of BPDs successfully reached the cytoplasm and the nuclear of spermatogenesis cell, and expressed in testes of transgene founder mice. Additionally, the ratio of founder mice obtained from BPDs (88%) is about 3 times higher than the control (25%) (p mice from BPD group were significantly improved, as compared with the control (p mice within the first filial was significantly higher in BPDs compared with the control (73.8% versus 11.6%, p mice in vivo.

  11. The Role of Cohesive Particle Interactions on Solids Uniformity and Mobilization During Jet Mixing: Testing Recommendations

    Energy Technology Data Exchange (ETDEWEB)

    Gauglitz, Phillip A.; Wells, Beric E.; Bamberger, Judith A.; Fort, James A.; Chun, Jaehun; Jenks, Jeromy WJ

    2010-04-01

    Radioactive waste that is currently stored in large underground tanks at the Hanford Site will be staged in selected double-shell tanks (DSTs) and then transferred to the Waste Treatment and Immobilization Plant (WTP). Before being transferred, the waste will be mixed, sampled, and characterized to determine if the waste composition and meets the waste feed specifications. Washington River Protection Solutions is conducting a Tank Mixing and Sampling Demonstration Program to determine the mixing effectiveness of the current baseline mixing system that uses two jet mixer pumps and the adequacy of the planned sampling method. The overall purpose of the demonstration program is to mitigate the technical risk associated with the mixing and sampling systems meeting the feed certification requirements for transferring waste to the WTP.The purpose of this report is to analyze existing data and evaluate whether scaled mixing tests with cohesive simulants are needed to meet the overall objectives of the small-scale mixing demonstration program. This evaluation will focus on estimating the role of cohesive particle interactions on various physical phenomena that occur in parts of the mixing process. A specific focus of the evaluation will be on the uniformity of suspended solids in the mixed region. Based on the evaluation presented in this report and the absence of definitive studies, the recommendation is to conduct scaled mixing tests with cohesive particles and augment the initial testing with non-cohesive particles. In addition, planning for the quantitative tests would benefit from having test results from some scoping experiments that would provide results on the general behavior when cohesive inter-particle forces are important.

  12. Performance Analysis Review of Thorium TRISO Coated Particles during Manufacture, Irradiation and Accident Condition Heating Tests

    International Nuclear Information System (INIS)

    2015-03-01

    Thorium, in combination with high enriched uranium, was used in all early high temperature reactors (HTRs). Initially, the fuel was contained in a kernel of coated particles. However, particle quality was low in the 1960s and early 1970s. Modern, high quality, tristructural isotropic (TRISO) fuel particles with thorium oxide and uranium dioxide (UO 2 ) had been manufactured since 1978 and were successfully demonstrated in irradiation and accident tests. In 1980, HTR fuels changed to low enriched uranium UO 2 TRISO fuels. The wide ranging development and demonstration programme was successful, and it established a worldwide standard that is still valid today. During the process, results of the thorium work with high quality TRISO fuel particles had not been fully evaluated or documented. This publication collects and presents the information and demonstrates the performance of thorium TRISO fuels.This publication is an outcome of the technical contract awarded under the IAEA Coordinated Research Project on Near Term and Promising Long Term Options for Deployment of Thorium Based Nuclear Energy, initiated in 2012. It is based on the compilation and analysis of available results on thorium TRISO coated particle performance in manufacturing and during irradiation and accident condition heating tests

  13. Proposed particle-beam characterizations for the APS undulator test line

    Energy Technology Data Exchange (ETDEWEB)

    Lumpkin, A.H.; Borland, M.; Milton, S.

    1993-09-01

    A research and development effort is underway at the Advanced Photon Source (APS) to use an rf gun as a low-emittance electron source for injection into the 100- to 650-MeV linac subsystem and subsequently to an undulator test area. This configuration would combine the acceleration capability of the 200-MeV S-band electron linac and the in-line 450-MeV positron linac that normally provide positrons to the positron accumulator ring (PAR). A transport line that bypasses the PAR will bring the electrons to the undulator test area. Characterization techniques will be discussed for the electron beam with a normalized, rms emittance of <10 {pi} mm mrad (1{sigma}) at micropulse charges of up to 350 pC and micropulse durations of {approximately}5 ps (FWHM). Tests proposed include measurement of particle beam transport effects (at one-tenth the storage ring beam rigidity) caused by small undulator field errors as well as operations intended to produce coherent, short wavelength radiation (<200 nm).

  14. Numerical thermal mathematical model correlation to thermal balance test using adaptive particle swarm optimization (APSO)

    International Nuclear Information System (INIS)

    Beck, T.; Bieler, A.; Thomas, N.

    2012-01-01

    We present structural and thermal model (STM) tests of the BepiColombo laser altimeter (BELA) receiver baffle with emphasis on the correlation of the data with a thermal mathematical model. The test unit is a part of the thermal and optical protection of the BELA instrument being tested under infrared and solar irradiation at University of Bern. An iterative optimization method known as particle swarm optimization has been adapted to adjust the model parameters, mainly the linear conductivity, in such a way that model and test results match. The thermal model reproduces the thermal tests to an accuracy of 4.2 °C ± 3.2 °C in a temperature range of 200 °C after using only 600 iteration steps of the correlation algorithm. The use of this method brings major benefits to the accuracy of the results as well as to the computational time required for the correlation. - Highlights: ► We present model correlations of the BELA receiver baffle to thermal balance tests. ► Adaptive particle swarm optimization has been adapted for the correlation. ► The method improves the accuracy of the correlation and the computational time.

  15. Nuclear Technology. Course 32: Nondestructive Examination (NDE) II. Module 32-3, Fundamentals of Magnetic Particle Testing.

    Science.gov (United States)

    Groseclose, Richard

    This third in a series of six modules for a course titled Nondestructive Examination (NDE) Techniques II explains the principles of magnets and magnetic fields and how they are applied in magnetic particle testing, describes the theory and methods of magnetizing test specimens, describes the test equipment used, discusses the principles and…

  16. LMFBR safety: Interim test report for the characterization of released particle tests conducted at INEL during FY 1979

    International Nuclear Information System (INIS)

    Johnson, R.P.; Nelson, C.T.

    1979-01-01

    Two additional atmospheric sodium release tests were jointly conducted by ESG and ARL at INEL. These tests were conducted under very stable (Pasquill E and G) meteorological conditions where the natural humidity content was high (47 and 96% RH). Sufficient experimental data was obtained on Test 7 to quantitatively qualify the formation of Na 2 CO 3 in the open atmosphere from primary sodium combustion products. These data show that a maximum concentration of approx. 60% Na 2 CO 3 is reached with the plume 100 meters from the release point. This concentration increases slightly as the plume is dispersed beyond 2400 meters. The available particle fallout data is consistent with predictions

  17. Key U.S.-built part fails during testing for world's largest particle collider

    CERN Multimedia

    2007-01-01

    "Scientists are scrambling to redesign a key U.S.-built part that broke "with a loud bang and a cloud of dust" during a high-pressure test for the world's largest particle physics collider that is supposed to start up in November, officials sais Tuesday." (1,5 page)

  18. Qualitative numerical studies of the modification of the pitch angle distribution of test particles by alfvènic wave activity

    Science.gov (United States)

    Keilbach, D.; Drews, C.; Berger, L.; Marsch, E.; Wimmer-Schweingruber, R. F.

    2017-12-01

    Using a test particle approach we have investigated, how an oxygen pickup ion torus velocity distribution is modified by continuous and intermittent alfvènic waves on timescales, where the gyro trajectory of each particle can be traced.We have therefore exposed the test particles to mono frequent waves, which expanded through the whole simulation in time and space. The general behavior of the pitch angle distribution is found to be stationary and a nonlinear function of the wave frequency, amplitude and the initial angle between wave elongation and field-perpendicular particle velocity vector. The figure shows the time-averaged pitch angle distributions as a function of the Doppler shifted wave frequency (where the Doppler shift was calculated with respect to the particles initial velocity) for three different wave amplitudes (labeled in each panel). The background field is chosen to be 5 nT and the 500 test particles were initially distributed on a torus with 120° pitch angle at a solar wind velocity of 450 km/s. Each y-slice of the histogram (which has been normalized to it's respective maximum) represents an individual run of the simulation.The frequency-dependent behavior of the test particles is found to be classifiable into the regimes of very low/high frequencies and frequencies close to first order resonance. We have found, that only in the latter regime the particles interact strongly with the wave, where in the time averaged histograms a branch structure is found, which was identified as a trace of particles co-moving with the wave phase. The magnitude of pitch angle change of these particles is as well as the frequency margin, where the branch structure is found, an increasing function with the wave amplitude.We have also investigated the interaction with mono frequent intermittent waves. Exposed to such waves a torus distribution is scattered in pitch angle space, whereas the pitch angle distribution is broadened systematically over time similar to

  19. Sampling, testing and modeling particle size distribution in urban catch basins.

    Science.gov (United States)

    Garofalo, G; Carbone, M; Piro, P

    2014-01-01

    The study analyzed the particle size distribution of particulate matter (PM) retained in two catch basins located, respectively, near a parking lot and a traffic intersection with common high levels of traffic activity. Also, the treatment performance of a filter medium was evaluated by laboratory testing. The experimental treatment results and the field data were then used as inputs to a numerical model which described on a qualitative basis the hydrological response of the two catchments draining into each catch basin, respectively, and the quality of treatment provided by the filter during the measured rainfall. The results show that PM concentrations were on average around 300 mg/L (parking lot site) and 400 mg/L (road site) for the 10 rainfall-runoff events observed. PM with a particle diameter of model showed that a catch basin with a filter unit can remove 30 to 40% of the PM load depending on the storm characteristics.

  20. Alpha particle physics experiments in the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    Zweben, S.J.; Budny, R.V.; Darrow, D.S.; Medley, S.S.; Nazikian, R.; Stratton, B.C.; Synakowski, E.J.; Taylor, G.

    2000-01-01

    Alpha particle physics experiments were done on TFTR during its DT run from 1993 to 1997. These experiments utilized several new alpha particle diagnostics and hundreds of DT discharges to characterize the alpha particle confinement and wave-particle interactions. In general, the results from the alpha particle diagnostics agreed with the classical single particle confinement model in MHD quiescent discharges. The alpha loss due to toroidal field ripple was identified in some cases, and the low radial diffusivity inferred for high energy alphas was consistent with orbit averaging over small scale turbulence. Finally, the observed alpha particle interactions with sawteeth, toroidal Alfven eigenmodes and ICRF waves were approximately consistent with theoretical modelling. What was learned is reviewed and what remains to be understood is identified. (author)

  1. Testing of a "smart-pebble" for measuring particle transport statistics

    Science.gov (United States)

    Kitsikoudis, Vasileios; Avgeris, Loukas; Valyrakis, Manousos

    2017-04-01

    This paper presents preliminary results from novel experiments aiming to assess coarse sediment transport statistics for a range of transport conditions, via the use of an innovative "smart-pebble" device. This device is a waterproof sphere, which has 7 cm diameter and is equipped with a number of sensors that provide information about the velocity, acceleration and positioning of the "smart-pebble" within the flow field. A series of specifically designed experiments are carried out to monitor the entrainment of a "smart-pebble" for fully developed, uniform, turbulent flow conditions over a hydraulically rough bed. Specifically, the bed surface is configured to three sections, each of them consisting of well packed glass beads of slightly increasing size at the downstream direction. The first section has a streamwise length of L1=150 cm and beads size of D1=15 mm, the second section has a length of L2=85 cm and beads size of D2=22 mm, and the third bed section has a length of L3=55 cm and beads size of D3=25.4 mm. Two cameras monitor the area of interest to provide additional information regarding the "smart-pebble" movement. Three-dimensional flow measurements are obtained with the aid of an acoustic Doppler velocimeter along a measurement grid to assess the flow forcing field. A wide range of flow rates near and above the threshold of entrainment is tested, while using four distinct densities for the "smart-pebble", which can affect its transport speed and total momentum. The acquired data are analyzed to derive Lagrangian transport statistics and the implications of such an important experiment for the transport of particles by rolling are discussed. The flow conditions for the initiation of motion, particle accelerations and equilibrium particle velocities (translating into transport rates), statistics of particle impact and its motion, can be extracted from the acquired data, which can be further compared to develop meaningful insights for sediment transport

  2. Short-duration Electron Precipitation Studied by Test Particle Simulation

    Directory of Open Access Journals (Sweden)

    Jaejin Lee

    2015-12-01

    Full Text Available Energy spectra of electron microbursts from 170 keV to 340 keV have been measured by the solid-state detectors aboard the low-altitude (680 km polar-orbiting Korean STSAT-1 (Science and Technology SATellite. These measurements have revealed two important characteristics unique to the microbursts: (1 They are produced by a fast-loss cone-filling process in which the interaction time for pitch-angle scattering is less than 50 ms and (2 The e-folding energy of the perpendicular component is larger than that of the parallel component, and the loss cone is not completely filled by electrons. To understand how wave-particle interactions could generate microbursts, we performed a test particle simulation and investigated how the waves scattered electron pitch angles within the timescale required for microburst precipitation. The application of rising-frequency whistler-mode waves to electrons of different energies moving in a dipole magnetic field showed that chorus magnetic wave fields, rather than electric fields, were the main cause of microburst events, which implied that microbursts could be produced by a quasi-adiabatic process. In addition, the simulation results showed that high-energy electrons could resonate with chorus waves at high magnetic latitudes where the loss cone was larger, which might explain the decreased e-folding energy of precipitated microbursts compared to that of trapped electrons.

  3. Equations of motion of test particles for solving the spin-dependent Boltzmann–Vlasov equation

    Energy Technology Data Exchange (ETDEWEB)

    Xia, Yin [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); University of Chinese Academy of Science, Beijing 100049 (China); Xu, Jun, E-mail: xujun@sinap.ac.cn [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China); Li, Bao-An [Department of Physics and Astronomy, Texas A& M University-Commerce, Commerce, TX 75429-3011 (United States); Department of Applied Physics, Xi' an Jiao Tong University, Xi' an 710049 (China); Shen, Wen-Qing [Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 (China)

    2016-08-10

    A consistent derivation of the equations of motion (EOMs) of test particles for solving the spin-dependent Boltzmann–Vlasov equation is presented. The resulting EOMs in phase space are similar to the canonical equations in Hamiltonian dynamics, and the EOM of spin is the same as that in the Heisenburg picture of quantum mechanics. Considering further the quantum nature of spin and choosing the direction of total angular momentum in heavy-ion reactions as a reference of measuring nucleon spin, the EOMs of spin-up and spin-down nucleons are given separately. The key elements affecting the spin dynamics in heavy-ion collisions are identified. The resulting EOMs provide a solid foundation for using the test-particle approach in studying spin dynamics in heavy-ion collisions at intermediate energies. Future comparisons of model simulations with experimental data will help to constrain the poorly known in-medium nucleon spin–orbit coupling relevant for understanding properties of rare isotopes and their astrophysical impacts.

  4. Installation and Characterization of Charged Particle Sources for Space Environmental Effects Testing

    Science.gov (United States)

    Skevington, Jennifer L.

    2010-01-01

    Charged particle sources are integral devices used by Marshall Space Flight Center s Environmental Effects Branch (EM50) in order to simulate space environments for accurate testing of materials and systems. By using these sources inside custom vacuum systems, materials can be tested to determine charging and discharging properties as well as resistance to sputter damage. This knowledge can enable scientists and engineers to choose proper materials that will not fail in harsh space environments. This paper combines the steps utilized to build a low energy electron gun (The "Skevington 3000") as well as the methods used to characterize the output of both the Skevington 3000 and a manufactured Xenon ion source. Such characterizations include beam flux, beam uniformity, and beam energy. Both sources were deemed suitable for simulating environments in future testing.

  5. Distribution and histologic effects of intravenously administered amorphous nanosilica particles in the testes of mice

    International Nuclear Information System (INIS)

    Morishita, Yuki; Yoshioka, Yasuo; Satoh, Hiroyoshi; Nojiri, Nao; Nagano, Kazuya; Abe, Yasuhiro; Kamada, Haruhiko; Tsunoda, Shin-ichi; Nabeshi, Hiromi; Yoshikawa, Tomoaki; Tsutsumi, Yasuo

    2012-01-01

    Highlights: ► There is rising concern regarding the potential health risks of nanomaterials. ► Few studies have investigated the effect of nanomaterials on the reproductive system. ► Here, we evaluated the intra-testicular distribution of nanosilica particles. ► We showed that nanosilica particles can penetrate the blood-testis barrier. ► These data provide basic information on ways to create safer nanomaterials. -- Abstract: Amorphous nanosilica particles (nSP) are being utilized in an increasing number of applications such as medicine, cosmetics, and foods. The reduction of the particle size to the nanoscale not only provides benefits to diverse scientific fields but also poses potential risks. Several reports have described the in vivo and in vitro toxicity of nSP, but few studies have examined their effects on the male reproductive system. The aim of this study was to evaluate the testicular distribution and histologic effects of systemically administered nSP. Mice were injected intravenously with nSP with diameters of 70 nm (nSP70) or conventional microsilica particles with diameters of 300 nm (nSP300) on two consecutive days. The intratesticular distribution of these particles 24 h after the second injection was analyzed by transmission electron microscopy. nSP70 were detected within sertoli cells and spermatocytes, including in the nuclei of spermatocytes. No nSP300 were observed in the testis. Next, mice were injected intravenously with 0.4 or 0.8 mg nSP70 every other day for a total of four administrations. Testes were harvested 48 h and 1 week after the last injection and stained with hematoxylin–eosin for histologic analysis. Histologic findings in the testes of nSP70-treated mice did not differ from those of control mice. Taken together, our results suggest that nSP70 can penetrate the blood-testis barrier and the nuclear membranes of spermatocytes without producing apparent testicular injury.

  6. Distribution and histologic effects of intravenously administered amorphous nanosilica particles in the testes of mice

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yuki [Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Yoshioka, Yasuo, E-mail: yasuo@phs.osaka-u.ac.jp [Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Satoh, Hiroyoshi; Nojiri, Nao [Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nagano, Kazuya [Laboratory of Biopharmaceutical Research, National Institute of Biomedical Innovation, 7-6-8 Saitoasagi, Ibaraki, Osaka 567-0085 (Japan); Abe, Yasuhiro [Cancer Biology Research Center, Sanford Research/USD, 2301 E. 60th Street N, Sioux Falls, SD 57104 (United States); Kamada, Haruhiko; Tsunoda, Shin-ichi [Laboratory of Biopharmaceutical Research, National Institute of Biomedical Innovation, 7-6-8 Saitoasagi, Ibaraki, Osaka 567-0085 (Japan); The Center for Advanced Medical Engineering and Informatics, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Nabeshi, Hiromi [Division of Foods, National Institute of Health Sciences, 1-18-1, Kamiyoga, Setagaya-ku, Tokyo 158-8501 (Japan); Yoshikawa, Tomoaki [Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Tsutsumi, Yasuo, E-mail: ytsutsumi@phs.osaka-u.ac.jp [Laboratory of Toxicology and Safety Science, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan); Laboratory of Biopharmaceutical Research, National Institute of Biomedical Innovation, 7-6-8 Saitoasagi, Ibaraki, Osaka 567-0085 (Japan); The Center for Advanced Medical Engineering and Informatics, Osaka University, 1-6 Yamadaoka, Suita, Osaka 565-0871 (Japan)

    2012-04-06

    Highlights: Black-Right-Pointing-Pointer There is rising concern regarding the potential health risks of nanomaterials. Black-Right-Pointing-Pointer Few studies have investigated the effect of nanomaterials on the reproductive system. Black-Right-Pointing-Pointer Here, we evaluated the intra-testicular distribution of nanosilica particles. Black-Right-Pointing-Pointer We showed that nanosilica particles can penetrate the blood-testis barrier. Black-Right-Pointing-Pointer These data provide basic information on ways to create safer nanomaterials. -- Abstract: Amorphous nanosilica particles (nSP) are being utilized in an increasing number of applications such as medicine, cosmetics, and foods. The reduction of the particle size to the nanoscale not only provides benefits to diverse scientific fields but also poses potential risks. Several reports have described the in vivo and in vitro toxicity of nSP, but few studies have examined their effects on the male reproductive system. The aim of this study was to evaluate the testicular distribution and histologic effects of systemically administered nSP. Mice were injected intravenously with nSP with diameters of 70 nm (nSP70) or conventional microsilica particles with diameters of 300 nm (nSP300) on two consecutive days. The intratesticular distribution of these particles 24 h after the second injection was analyzed by transmission electron microscopy. nSP70 were detected within sertoli cells and spermatocytes, including in the nuclei of spermatocytes. No nSP300 were observed in the testis. Next, mice were injected intravenously with 0.4 or 0.8 mg nSP70 every other day for a total of four administrations. Testes were harvested 48 h and 1 week after the last injection and stained with hematoxylin-eosin for histologic analysis. Histologic findings in the testes of nSP70-treated mice did not differ from those of control mice. Taken together, our results suggest that nSP70 can penetrate the blood-testis barrier and the

  7. Irradiation test HT-31: high-temperature irradiation behavior of LASL-made extruded fuel rods and LASL-made coated particles

    International Nuclear Information System (INIS)

    Wagner, P.; Reiswig, R.D.; Hollabaugh, C.M.; White, R.W.; Davidson, K.V.; Schell, D.H.

    1977-04-01

    Three LASL-made extruded graphite and coated particle fuel rods have been irradiated in the Oak Ridge National Laboratory High Fluence Isotope Reactor test HT-31. Test conditions were about 9 x 10 21 nvt(E > .18 MeV) at 1250 0 C. The graphite matrix showed little or no effect of the irradiation. LASL-made ZrC containing coated particles with ZrC coats and ZrC-doped pyrolytic carbon coats showed no observable effects of the irradiation

  8. Fermilab | Particle Physics Division

    Science.gov (United States)

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

  9. Behavior of LASL-made graphite, ZrC, and ZrC-containing coated particles in irradiation tests HT-28 and HT-29

    International Nuclear Information System (INIS)

    Reiswig, R.D.; Wagner, P.; Hollabaugh, C.M.; White, R.W.; O'Rourke, J.A.; Davidson, K.V.; Schell, D.H.

    1976-01-01

    Three types of materials, extruded graphite, hot-pressed ZrC, and particles with ZrC coatings, were irradiated in ORNL High Fluence Isotope Reactor Irradiation tests HT-28 and HT-29. The ZrC seemed unaffected. The graphite changed in dimensions, x-ray diffraction parameters, and thermal conductivity. The four types of coated particles tested all resisted the irradiation well, except one set of particles with double-graded C-ZrC-C coats. Overall, the results were considered encouraging for use of ZrC and extruded graphite fuel matrices. 16 fig

  10. The Eccentric Kozai–Lidov Mechanism for Outer Test Particle

    Energy Technology Data Exchange (ETDEWEB)

    Naoz, Smadar [Department of Physics and Astronomy, University of California, Los Angeles, CA 90095 (United States); Li, Gongjie [Harvard Smithsonian Center for Astrophysics, Institute for Theory and Computation, 60 Garden Street, Cambridge, MA 02138 (United States); Zanardi, Macarena; De Elía, Gonzalo Carlos; Di Sisto, Romina P., E-mail: snaoz@astro.ucla.edu [Instituto de Astrofísica de La Plata, CCT La Plata-CONICET-UNLP Paseo del Bosque S/N (1900), La Plata (Argentina)

    2017-07-01

    The secular approximation of the hierarchical three body systems has been proven to be very useful in addressing many astrophysical systems, from planets to stars to black holes. In such a system, two objects are on a tight orbit and the tertiary is on a much wider orbit. Here, we study the dynamics of a system by taking the tertiary mass to zero and solve the hierarchical three body system up to the octupole level of approximation. We find a rich dynamics that the outer orbit undergoes due to gravitational perturbations from the inner binary. The nominal result of the precession of the nodes is mostly limited for the lowest order of approximation; however, when the octupole level of approximation is introduced, the system becomes chaotic, as expected, and the tertiary oscillates below and above 90°, similarly to the non-test particle flip behavior. We provide the Hamiltonian of the system and investigate the dynamics of the system from the quadrupole to the octupole level of approximations. We also analyze the chaotic and quasi-periodic orbital evolution by studying the surfaces of sections. Furthermore, including general relativity, we showcase the long-term evolution of individual debris disk particles under the influence of a far-away interior eccentric planet. We show that this dynamics can naturally result in retrograde objects and a puffy disk after a long timescale evolution (a few Gyr) for initially aligned configuration.

  11. The Eccentric Kozai-Lidov Mechanism for Outer Test Particle

    Science.gov (United States)

    Naoz, Smadar; Li, Gongjie; Zanardi, Macarena; de Elía, Gonzalo Carlos; Di Sisto, Romina P.

    2017-07-01

    The secular approximation of the hierarchical three body systems has been proven to be very useful in addressing many astrophysical systems, from planets to stars to black holes. In such a system, two objects are on a tight orbit and the tertiary is on a much wider orbit. Here, we study the dynamics of a system by taking the tertiary mass to zero and solve the hierarchical three body system up to the octupole level of approximation. We find a rich dynamics that the outer orbit undergoes due to gravitational perturbations from the inner binary. The nominal result of the precession of the nodes is mostly limited for the lowest order of approximation; however, when the octupole level of approximation is introduced, the system becomes chaotic, as expected, and the tertiary oscillates below and above 90°, similarly to the non-test particle flip behavior. We provide the Hamiltonian of the system and investigate the dynamics of the system from the quadrupole to the octupole level of approximations. We also analyze the chaotic and quasi-periodic orbital evolution by studying the surfaces of sections. Furthermore, including general relativity, we showcase the long-term evolution of individual debris disk particles under the influence of a far-away interior eccentric planet. We show that this dynamics can naturally result in retrograde objects and a puffy disk after a long timescale evolution (a few Gyr) for initially aligned configuration.

  12. Test of the photon detection system for the LHCb RICH Upgrade in a charged particle beam

    CERN Document Server

    Baszczyk, M.K.

    2017-01-16

    The LHCb detector will be upgraded to make more efficient use of the available luminosity at the LHC in Run III and extend its potential for discovery. The Ring Imaging Cherenkov detectors are key components of the LHCb detector for particle identification. In this paper we describe the setup and the results of tests in a charged particle beam, carried out to assess prototypes of the upgraded opto-electronic chain from the Multi-Anode PMT photosensor to the readout and data acquisition system.

  13. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Science.gov (United States)

    Villa, Carlo E; Caccia, Michele; Sironi, Laura; D'Alfonso, Laura; Collini, Maddalena; Rivolta, Ilaria; Miserocchi, Giuseppe; Gorletta, Tatiana; Zanoni, Ivan; Granucci, Francesca; Chirico, Giuseppe

    2010-08-17

    The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  14. Accumulative difference image protocol for particle tracking in fluorescence microscopy tested in mouse lymphonodes.

    Directory of Open Access Journals (Sweden)

    Carlo E Villa

    Full Text Available The basic research in cell biology and in medical sciences makes large use of imaging tools mainly based on confocal fluorescence and, more recently, on non-linear excitation microscopy. Substantially the aim is the recognition of selected targets in the image and their tracking in time. We have developed a particle tracking algorithm optimized for low signal/noise images with a minimum set of requirements on the target size and with no a priori knowledge of the type of motion. The image segmentation, based on a combination of size sensitive filters, does not rely on edge detection and is tailored for targets acquired at low resolution as in most of the in-vivo studies. The particle tracking is performed by building, from a stack of Accumulative Difference Images, a single 2D image in which the motion of the whole set of the particles is coded in time by a color level. This algorithm, tested here on solid-lipid nanoparticles diffusing within cells and on lymphocytes diffusing in lymphonodes, appears to be particularly useful for the cellular and the in-vivo microscopy image processing in which few a priori assumption on the type, the extent and the variability of particle motions, can be done.

  15. Heterogeneity of high-density lipoprotein particles and insulin output during oral glucose tolerance test in men with coronary artery disease.

    Science.gov (United States)

    Iwanejko, J; Kwaśniak, M; Wybrańska, I; Hartwich, J; Guevara, I; Zdzienicka, A; Kruszelnicka-Kwiatkowska, O; Piwowarska, W; Miszczuk-Jamska, B; Dembińska-Kieć, A

    1996-03-01

    We compared the high-density lipoprotein (HDL) composition and particle heterogeneity in 60 nonobese (normal body mass index, BMI) men suffering from coronary artery disease (CAD) with normolipemia and normoinsulinemia with lower and higher insulin output during the oral glucose tolerance test (silent hyperinsulinemia). The apolipoprotein apoAI, apoAII, and apoE levels were higher in the high insulin response (HI) group than in low insulin response (LI) group. The ratio of apoAI versus total protein and the ratio of apoAI versus total cholesterol were increased in HI compared with LI. The lipid components in HDL were higher in LI than in HI, while for HDL2 they were higher in HI. The fractioning of HDL by gradient gel electrophoresis revealed a different pattern of HDL particles in both groups. The larger particles, HDL2b and HDL2a (mean particle diameters 10.6 and 9.2 nm, respectively), occur more frequently in HI patients (up to 60%) than in LI patients, whereas the smaller particles, HDL3a and HDL3b (mean particle diameters 8.6 and 7.8 nm, respectively), predominate in LI patients. Our results demonstrate that even in the normoglycemic, normocholesterolemic CAD patients, a high insulin output observed during the oral glucose tolerance test may be connected with a different HDL particle pattern, which suggests changes in the reverse cholesterol transport.

  16. Aspects of the statistical theory of stochastic magnetic fields: test particle transport and turbulent collisionless tearing mode

    International Nuclear Information System (INIS)

    Kleva, R.G.

    1980-01-01

    The first part of this work is concerned with test particle transport in a stochastic magnetic field. In the absence of collisions, the test particle self-diffusion coefficient is given by D = D/sub m/ V (in the zero gyroradius limit), where D/sub m/ is the magnetic diffusion coefficient due to a given spectrum of magnetic fluctuations and V is the particle velocity along a field line. The effect of collisions, either classical or turbulent, on this result is considered. The second part of this work is concerned with the evolution of the collisionless tearing mode in the presence of a stochastic magnetic field. A statistical closure approximation, obtained from the DIA by neglecting a mode-coupling term, is used to derive a nonlinear dispersion relation. For L 0 < L/sub K/ the dominant nonlinear effect is shown to be a turbulent broadening of the perturbed current layer. Saturation occurs when the perturbed current layer broadens to the point where Δ' = 0, where Δ' is the jump in the logarithmic derivative of the vector potential across the perturbed current layer

  17. Structure of the generalized momentum of a test charged particle and the inverse problem in general relativity theory

    International Nuclear Information System (INIS)

    Zakharov, A.V.; Singatullin, R.S.

    1981-01-01

    The inverse problem is solved in general relativity theory (GRT) consisting in determining the metric and potentials of an electromagnetic field by their values in the nonsingular point of the V 4 space and present functions, being the generalized momenta of a test charged particle. The Hamilton-Jacobi equation for a test charged particle in GRT is used. The general form of the generalized momentum dependence on the initial values is determined. It is noted that the inverse problem solution of dynamics in GRT contains arbitrariness which depends on the choice of the metric and potential values of the electromagnetic field in the nonsingular point [ru

  18. Acceptance Test Data for BWXT Coated Particle Batch 93164A Defective IPyC Fraction and Pyrocarbon Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Skitt, Darren J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dyer, John A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-02-01

    Coated particle fuel batch J52O-16-93164 was produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), or may be used as demonstration production-scale coated particle fuel for other experiments. The tristructural-isotropic (TRISO) coatings were deposited in a 150-mm-diameter production-scale fluidizedbed chemical vapor deposition (CVD) furnace onto 425-μm-nominal-diameter spherical kernels from BWXT lot J52L-16-69316. Each kernel contained a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO) and was coated with four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. The TRISO-coated particle batch was sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batch was designated by appending the letter A to the end of the batch number (i.e., 93164A).

  19. Destroying charged black holes in higher dimensions with test particles

    Science.gov (United States)

    Wu, Bin; Liu, Weiyang; Tang, Hao; Yue, Rui-Hong

    2017-07-01

    A possible way to destroy the Tangherlini Reissner-Nordström black hole is discussed in the spirit of Wald’s gedanken experiment. By neglecting radiation and self force effects, the absorbing condition and destruction condition of the test point particle which is capable of destroying the black hole are obtained. We find that it is impossible to challenge the weak cosmic censorship for an initially extremal black hole in all dimensions. Instead, it is shown that the near extremal black hole will turn into a naked singularity in this particular process, in which case the allowed range of the particle’s energy is very narrow. The result indicates that the self-force effects may well change the outcome of the calculation.

  20. Nanoparticle filtration performance of NIOSH-certified particulate air-purifying filtering facepiece respirators: evaluation by light scattering photometric and particle number-based test methods.

    Science.gov (United States)

    Rengasamy, Samy; Eimer, Benjamin C

    2012-01-01

    National Institute for Occupational Safety and Health (NIOSH) certification test methods employ charge neutralized NaCl or dioctyl phthalate (DOP) aerosols to measure filter penetration levels of air-purifying particulate respirators photometrically using a TSI 8130 automated filter tester at 85 L/min. A previous study in our laboratory found that widely different filter penetration levels were measured for nanoparticles depending on whether a particle number (count)-based detector or a photometric detector was used. The purpose of this study was to better understand the influence of key test parameters, including filter media type, challenge aerosol size range, and detector system. Initial penetration levels for 17 models of NIOSH-approved N-, R-, and P-series filtering facepiece respirators were measured using the TSI 8130 photometric method and compared with the particle number-based penetration (obtained using two ultrafine condensation particle counters) for the same challenge aerosols generated by the TSI 8130. In general, the penetration obtained by the photometric method was less than the penetration obtained with the number-based method. Filter penetration was also measured for ambient room aerosols. Penetration measured by the TSI 8130 photometric method was lower than the number-based ambient aerosol penetration values. Number-based monodisperse NaCl aerosol penetration measurements showed that the most penetrating particle size was in the 50 nm range for all respirator models tested, with the exception of one model at ~200 nm size. Respirator models containing electrostatic filter media also showed lower penetration values with the TSI 8130 photometric method than the number-based penetration obtained for the most penetrating monodisperse particles. Results suggest that to provide a more challenging respirator filter test method than what is currently used for respirators containing electrostatic media, the test method should utilize a sufficient number

  1. Phaco-efficiency test and re-aspiration analysis of repulsed particle in phacoemulsification.

    Science.gov (United States)

    Kim, Jae-hyung; Ko, Dong-Ah; Kim, Jae Yong; Kim, Myoung Joon; Tchah, Hungwon

    2013-04-01

    To measure the efficiency of phacoemulsification, we have developed a new experimental model for testing phaco-efficiency and analyzed re-aspiration of repulsed particles. Using a Kitaro wetlab system, a piece of blood agar (BA) was placed in an artificial chamber and the phacoemulsifier was placed horizontally. The settings of the phacoemulsifier (Infiniti, Alcon Laboratories) were 26 cc/min for aspiration, 350 cc/min for vacuum, and 95 cm of bottle height. The time to remove BAs was measured using Ozil 100 %, Ozil 40 %, and longitudinal 40 % of phaco power. The angle between the re-aspirated BA particles and the axis of the phacoemulsifier (re-aspiration zone, degree) was analyzed. The average time (seconds) to remove BAs was lower in the Ozil 100 % and the Ozil 40 % mode than in the longitudinal mode (0.37 ± 0.39, 0.85 ± 0.57, and 2.22 ± 1.40 respectively, P value < 0.01). Repulsion exceeding 1 mm occurred more frequently in the longitudinal mode than in the Ozil 100 % mode (100 % vs 40 %, P value = 0.01, Fisher's exact test). The average of re-aspiration zone was 25.9 ± 14.5 in the longitudinal 40 % and 54.0 ± 23.0 in the Ozil 40 % (P value = 0.016). The Ozil mode was more efficient than the longitudinal mode. In addition, the Ozil mode provided less repulsion and wider aspiration zone.

  2. Test-particle simulations of SEP propagation in IMF with large-scale fluctuations

    Science.gov (United States)

    Kelly, J.; Dalla, S.; Laitinen, T.

    2012-11-01

    The results of full-orbit test-particle simulations of SEPs propagating through an IMF which exhibits large-scale fluctuations are presented. A variety of propagation conditions are simulated - scatter-free, and scattering with mean free path, λ, of 0.3 and 2.0 AU - and the cross-field transport of SEPs is investigated. When calculating cross-field displacements the Parker spiral geometry is accounted for and the role of magnetic field expansion is taken into account. It is found that transport across the magnetic field is enhanced in the λ =0.3 AU and λ =2 AU cases, compared to the scatter-free case, with the λ =2 AU case in particular containing outlying particles that had strayed a large distance across the IMF. Outliers are catergorized by means of Chauvenet's criterion and it is found that typically between 1 and 2% of the population falls within this category. The ratio of latitudinal to longitudinal diffusion coefficient perpendicular to the magnetic field is typically 0.2, suggesting that transport in latitude is less efficient.

  3. Drift Wave Test Particle Transport in Reversed Shear Profile

    International Nuclear Information System (INIS)

    Horton, W.; Park, H.B.; Kwon, J.M.; Stronzzi, D.; Morrison, P.J.; Choi, D.I.

    1998-01-01

    Drift wave maps, area preserving maps that describe the motion of charged particles in drift waves, are derived. The maps allow the integration of particle orbits on the long time scale needed to describe transport. Calculations using the drift wave maps show that dramatic improvement in the particle confinement, in the presence of a given level and spectrum of E x B turbulence, can occur for q(r)-profiles with reversed shear. A similar reduction in the transport, i.e. one that is independent of the turbulence, is observed in the presence of an equilibrium radial electric field with shear. The transport reduction, caused by the combined effects of radial electric field shear and both monotonic and reversed shear magnetic q-profiles, is also investigated

  4. Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

    Science.gov (United States)

    Hunt, J. R.; Smith, D. K.

    2004-12-01

    The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the

  5. Enhanced stopping of macro-particles in particle-in-cell simulations

    International Nuclear Information System (INIS)

    May, J.; Tonge, J.; Ellis, I.; Mori, W. B.; Fiuza, F.; Fonseca, R. A.; Silva, L. O.; Ren, C.

    2014-01-01

    We derive an equation for energy transfer from relativistic charged particles to a cold background plasma appropriate for finite-size particles that are used in particle-in-cell simulation codes. Expressions for one-, two-, and three-dimensional particles are presented, with special attention given to the two-dimensional case. This energy transfer is due to the electric field of the wake set up in the background plasma by the relativistic particle. The enhanced stopping is dependent on the q 2 /m, where q is the charge and m is the mass of the relativistic particle, and therefore simulation macro-particles with large charge but identical q/m will stop more rapidly. The stopping power also depends on the effective particle shape of the macro-particle. These conclusions are verified in particle-in-cell simulations. We present 2D simulations of test particles, relaxation of high-energy tails, and integrated fast ignition simulations showing that the enhanced drag on macro-particles may adversely affect the results of these simulations in a wide range of high-energy density plasma scenarios. We also describe a particle splitting algorithm which can potentially overcome this problem and show its effect in controlling the stopping of macro-particles

  6. System tests of the LHCb RICH detectors in a charged particle beam

    CERN Document Server

    Skottowe, Hugh

    2009-01-01

    The RICH detectors of the LHCb experiment will provide efficient particle identification over the momentum range 1-100 GeV=c. Results are presented from a beam test of the LHCb RICH system using final production pixel Hybrid Photon Detectors, the final readout electronics and an adapted version of LHCb RICH reconstruction software. Measurements of the photon yields and Cherenkov angle resolutions for both nitrogen and C4F10 radiators agree well with full simulations. The quality of the data and the results obtained demonstrate that all aspects meet the stringent physics requirements of the experiment are now ready for first data.

  7. Zwitters: Particles between quantum and classical

    International Nuclear Information System (INIS)

    Wetterich, C.

    2012-01-01

    We describe both quantum particles and classical particles in terms of a classical statistical ensemble, with a probability distribution in phase space. By use of a wave function in phase space both can be treated in the same quantum formalism. Quantum particles are characterized by a specific choice of observables and time evolution of the probability density. Then interference and tunneling are found within classical statistics. Zwitters are (effective) one-particle states for which the time evolution interpolates between quantum and classical particles. Experimental bounds on a small parameter can test quantum mechanics. -- Highlights: ► Quantum particles can be described within classical statistics. ► Classical particles are formulated in quantum formalism. ► Zwitters interpolate between classical and quantum particles. ► Zwitters allow for quantitative tests of quantum mechanics. ► Zwitters could be effective one-particle descriptions of droplets.

  8. Performance of PC-based charged particle multi-channel spectrometer utilising particle identification

    International Nuclear Information System (INIS)

    Palla, G.; Sziklai, J.; Trajber, Cs.

    1993-12-01

    A collaterally expandable charged particle spectrometer based on PC control and particle identification is described. A typical system configuration consisting of two channels are used to test the system performance. (author) 7 refs.; 5 figs

  9. Testing the standard model of particle physics using lattice QCD

    International Nuclear Information System (INIS)

    Water, Ruth S van de

    2007-01-01

    Recent advances in both computers and algorithms now allow realistic calculations of Quantum Chromodynamics (QCD) interactions using the numerical technique of lattice QCD. The methods used in so-called '2+1 flavor' lattice calculations have been verified both by post-dictions of quantities that were already experimentally well-known and by predictions that occurred before the relevant experimental determinations were sufficiently precise. This suggests that the sources of systematic error in lattice calculations are under control, and that lattice QCD can now be reliably used to calculate those weak matrix elements that cannot be measured experimentally but are necessary to interpret the results of many high-energy physics experiments. These same calculations also allow stringent tests of the Standard Model of particle physics, and may therefore lead to the discovery of new physics in the future

  10. A Comprehensive Comparison of Relativistic Particle Integrators

    Science.gov (United States)

    Ripperda, B.; Bacchini, F.; Teunissen, J.; Xia, C.; Porth, O.; Sironi, L.; Lapenta, G.; Keppens, R.

    2018-03-01

    We compare relativistic particle integrators commonly used in plasma physics, showing several test cases relevant for astrophysics. Three explicit particle pushers are considered, namely, the Boris, Vay, and Higuera–Cary schemes. We also present a new relativistic fully implicit particle integrator that is energy conserving. Furthermore, a method based on the relativistic guiding center approximation is included. The algorithms are described such that they can be readily implemented in magnetohydrodynamics codes or Particle-in-Cell codes. Our comparison focuses on the strengths and key features of the particle integrators. We test the conservation of invariants of motion and the accuracy of particle drift dynamics in highly relativistic, mildly relativistic, and non-relativistic settings. The methods are compared in idealized test cases, i.e., without considering feedback onto the electrodynamic fields, collisions, pair creation, or radiation. The test cases include uniform electric and magnetic fields, {\\boldsymbol{E}}× {\\boldsymbol{B}} fields, force-free fields, and setups relevant for high-energy astrophysics, e.g., a magnetic mirror, a magnetic dipole, and a magnetic null. These tests have direct relevance for particle acceleration in shocks and in magnetic reconnection.

  11. Opportunities for the Reduction of Substances and Equipment Impact on Personnel in Penetrant and Magnetic Particles Testing

    OpenAIRE

    Yaremenko, Yuriy

    2015-01-01

    Penetrant testing (PT) and magnetic particles inspection (MPI) are widespread methods of non-destructive testing which are not required a lot of investments for manual application and are simple in terms of discontinuous interpretation. On the other hand, work with chemicals requires special precautions, safety instructions and disposal limitations. Growing demand among customers to decrease impact of consumables and equipment on personnel and environment, shift producers’ priorities to devel...

  12. Quantum Dynamics of Test Particle in Curved Space-Time

    International Nuclear Information System (INIS)

    Piechocki, W.

    2002-01-01

    To reveal the nature of space-time singularities of removable type we examine classical and quantum dynamics of a free particle in the Sitter type spacetimes. Consider space-times have different topologies otherwise are isometric. Our systems are integrable and we present analytic solutions of the classical dynamics. We quantize the systems by making use of the group theoretical method: we find an essentially self-adjoint representation of the algebra of observables integrable to the irreducible unitarity representation of the symmetry group of each consider gravitational system. The massless particle dynamics is obtained in the zero-mass limit of the massive case. Global properties of considered gravitational systems are of primary importance for the quantization procedure. Systems of a particle in space-times with removable singularities appear to be quantizable. We give specific proposal for extension of our analysis to space-times with essential type singularities. (author)

  13. New particle accelerations by magnetized plasma shock waves

    International Nuclear Information System (INIS)

    Takeuchi, Satoshi

    2005-01-01

    Three mechanisms concerning particle accelerations are proposed to account for the high energy of cosmic rays. A model of magnetized plasma clouds is used to simulate a shock-type wave. The attainable energies of test particles colliding with the moving magnetic clouds are investigated by analytical and numerical methods for the three mechanisms. The magnetic trapping acceleration is a new type of particle trapping and acceleration in which, in principle, the test particle is accelerated indefinitely; hence, this mechanism surpasses the Fermi-type acceleration. In the single-step acceleration, the test particle obtains a significant energy gain even though it only experiences a single collision. Lastly, there is the bouncing acceleration by which the test particle is substantially accelerated due to repeated collisions

  14. Chaos in the motion of a test scalar particle coupling to the Einstein tensor in Schwarzschild-Melvin black hole spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Mingzhi [Hunan Normal University, Department of Physics, Institute of Physics, Changsha, Hunan (China); Hunan Normal University, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Chen, Songbai; Jing, Jiliang [Hunan Normal University, Department of Physics, Institute of Physics, Changsha, Hunan (China); Hunan Normal University, Key Laboratory of Low Dimensional Quantum Structures and Quantum Control of Ministry of Education, Changsha, Hunan (China); Hunan Normal University, Synergetic Innovation Center for Quantum Effects and Applications, Changsha, Hunan (China)

    2017-04-15

    We present firstly the equation of motion for a test scalar particle coupling to the Einstein tensor in the Schwarzschild-Melvin black hole spacetime through the short-wave approximation. Through analyzing Poincare sections, the power spectrum, the fast Lyapunov exponent indicator and the bifurcation diagram, we investigate the effects of the coupling parameter on the chaotic behavior of the particles. With the increase of the coupling strength, we find that the motion of the coupled particle for the chosen parameters becomes more regular and order for the negative couple constant. While, for the positive one, the motion of the coupled particles first undergoes a series of transitions betweens chaotic motion and regular motion and then falls into horizon or escapes to spatial infinity. Our results show that the coupling brings about richer effects for the motion of the particles. (orig.)

  15. Determination of particle-release conditions in microfiltration: A simple single-particle model tested on a model membrane

    NARCIS (Netherlands)

    Kuiper, S.; van Rijn, C.J.M.; Nijdam, W.; Krijnen, Gijsbertus J.M.; Elwenspoek, Michael Curt

    2000-01-01

    A simple single-particle model was developed for cross-flow microfiltration with microsieves. The model describes the cross-flow conditions required to release a trapped spherical particle from a circular pore. All equations are derived in a fully analytical way without any fitting parameters. For

  16. Comparison between Genetic Algorithms and Particle Swarm Optimization Methods on Standard Test Functions and Machine Design

    DEFF Research Database (Denmark)

    Nica, Florin Valentin Traian; Ritchie, Ewen; Leban, Krisztina Monika

    2013-01-01

    , genetic algorithm and particle swarm are shortly presented in this paper. These two algorithms are tested to determine their performance on five different benchmark test functions. The algorithms are tested based on three requirements: precision of the result, number of iterations and calculation time....... Both algorithms are also tested on an analytical design process of a Transverse Flux Permanent Magnet Generator to observe their performances in an electrical machine design application.......Nowadays the requirements imposed by the industry and economy ask for better quality and performance while the price must be maintained in the same range. To achieve this goal optimization must be introduced in the design process. Two of the best known optimization algorithms for machine design...

  17. The radiochromic dye film dose meter as a possible test of particle track theory

    International Nuclear Information System (INIS)

    Hansen, J.W.; Jensen, M.; Katz, R.

    1980-09-01

    The response characteristic of the thin-film radiometric dye cyanide plastic dose meter to ionizing radiation of electrons and heavy charged particles is investigated as a possible test of the particle track theory worked out by Robert Katz and coworkers. Dose response curves for low-LET radiation have been investigated and are used for a quality estimation of the response for protons and oxygen ions at 16 and 4 MeV/amu, respectively. A bleaching effect on the colouration at high doses intimates that the target cannot be interpreted lieerally, but it might still be possinle to transfer the function of the macroscopic dose response to a theoretical dose response curve in a microscopic scale for a single ion. From this relation the macroscopic dose response curve can be determined qhen the film is irradiated with heavy ions. It will be shown theoretically that for protons there is no saturation in the track core, whereas calculations for oxygen ions show a heavy saturation in the track core, which means that a part of the ions loose their energy ineffectively. We can conclude that itis possible qualitatively to predict the dose response curve for high-LET particles by means of the dose response curve for low-LET radiation. (author)

  18. Comparative assessment of pressure field reconstructions from particle image velocimetry measurements and Lagrangian particle tracking

    NARCIS (Netherlands)

    van Gent, P.L.; Michaelis, D; van Oudheusden, B.W.; Weiss, P.E.; de Kat, R.; Laskari, A.; Jeon, Y.J.; David, L; Schanz, D; Huhn, F.; Gesemann, S; Novara, M.; McPhaden, C.; Neeteson, N. J.; Rival, David E.; Schneiders, J.F.G.; Schrijer, F.F.J.

    2017-01-01

    A test case for pressure field reconstruction from particle image velocimetry (PIV) and Lagrangian particle tracking (LPT) has been developed by constructing a simulated experiment from a zonal detached eddy simulation for an axisymmetric base flow at Mach 0.7. The test case comprises sequences

  19. Large-scale generic test stand for testing of multiple configurations of air filters utilizing a range of particle size distributions

    Science.gov (United States)

    Giffin, Paxton K.; Parsons, Michael S.; Unz, Ronald J.; Waggoner, Charles A.

    2012-05-01

    The Institute for Clean Energy Technology (ICET) at Mississippi State University has developed a test stand capable of lifecycle testing of high efficiency particulate air filters and other filters specified in American Society of Mechanical Engineers Code on Nuclear Air and Gas Treatment (AG-1) filters. The test stand is currently equipped to test AG-1 Section FK radial flow filters, and expansion is currently underway to increase testing capabilities for other types of AG-1 filters. The test stand is capable of producing differential pressures of 12.45 kPa (50 in. w.c.) at volumetric air flow rates up to 113.3 m3/min (4000 CFM). Testing is performed at elevated and ambient conditions for temperature and relative humidity. Current testing utilizes three challenge aerosols: carbon black, alumina, and Arizona road dust (A1-Ultrafine). Each aerosol has a different mass median diameter to test loading over a wide range of particles sizes. The test stand is designed to monitor and maintain relative humidity and temperature to required specifications. Instrumentation is implemented on the upstream and downstream sections of the test stand as well as on the filter housing itself. Representative data are presented herein illustrating the test stand's capabilities. Digital images of the filter pack collected during and after testing is displayed after the representative data are discussed. In conclusion, the ICET test stand with AG-1 filter testing capabilities has been developed and hurdles such as test parameter stability and design flexibility overcome.

  20. NMR relaxation induced by iron oxide particles: testing theoretical models.

    Science.gov (United States)

    Gossuin, Y; Orlando, T; Basini, M; Henrard, D; Lascialfari, A; Mattea, C; Stapf, S; Vuong, Q L

    2016-04-15

    Superparamagnetic iron oxide particles find their main application as contrast agents for cellular and molecular magnetic resonance imaging. The contrast they bring is due to the shortening of the transverse relaxation time T 2 of water protons. In order to understand their influence on proton relaxation, different theoretical relaxation models have been developed, each of them presenting a certain validity domain, which depends on the particle characteristics and proton dynamics. The validation of these models is crucial since they allow for predicting the ideal particle characteristics for obtaining the best contrast but also because the fitting of T 1 experimental data by the theory constitutes an interesting tool for the characterization of the nanoparticles. In this work, T 2 of suspensions of iron oxide particles in different solvents and at different temperatures, corresponding to different proton diffusion properties, were measured and were compared to the three main theoretical models (the motional averaging regime, the static dephasing regime, and the partial refocusing model) with good qualitative agreement. However, a real quantitative agreement was not observed, probably because of the complexity of these nanoparticulate systems. The Roch theory, developed in the motional averaging regime (MAR), was also successfully used to fit T 1 nuclear magnetic relaxation dispersion (NMRD) profiles, even outside the MAR validity range, and provided a good estimate of the particle size. On the other hand, the simultaneous fitting of T 1 and T 2 NMRD profiles by the theory was impossible, and this occurrence constitutes a clear limitation of the Roch model. Finally, the theory was shown to satisfactorily fit the deuterium T 1 NMRD profile of superparamagnetic particle suspensions in heavy water.

  1. Physical test of a particle simulation model in a sheared granular system

    Energy Technology Data Exchange (ETDEWEB)

    Rycroft, Chris; Orpe, Ashish; Kudrolli, Arshad

    2009-01-15

    We report a detailed comparison of a slow gravity driven sheared granular flow with a computational model performed with the Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS). To our knowledge, this is the first thorough test of the LAMMPS model with a laboratory granular flow. In the experiments, grains flow inside a silo with a rectangular cross-section, and are sheared by a rough boundary on one side and smooth boundaries on the other sides. Individual grain position and motion are measured using a particle index matching imaging technique where a fluorescent dye is added to the interstitial liquid which has the same refractive index as the glass beads. The boundary imposes a packing order, and the grains are observed to flow in layers which get progressively more disordered with distance from the walls. The computations use a Cundall--Strack contact model between the grains, using contact parameters that have been used in many other previous studies, and ignore the hydrodynamic effects of the interstitial liquid. Computations are performed to understand the effect of particle coefficient of friction, elasticity, contact model, and polydispersity on mean flow properties. After appropriate scaling, we find that the mean velocity of the grains and the number density as a function of flow cross-section observed in the experiments and the simulations are in excellent agreement. The mean flow profile is observed to be unchanged over a broad range of coefficient of friction, except near the smooth wall. We show that the flow profile is not sensitive to atleast 10\\percent polydispersity in particle size. Because the grain elasticity used is smaller in the computations as compared with glass grains, wave-like features can be noted over short time scales in the mean velocity and the velocity auto-correlations measured in the simulations. These wave features occur over an intermediate timescale larger than the particle interaction but smaller than the

  2. Beam test of a 12-layer scintillating-fiber charged-particle tracking system

    Energy Technology Data Exchange (ETDEWEB)

    Abbott, B.; Howell, B.L.; Koltick, D.; McIlwain, R.L.; Schmitz, C.J.; Shibata, E.I.; Zhou, Z.; Baumbaugh, B.; Ivancic, M.; Jaques, J.; Kehoe, R.; Kelley, M.; Mahoney, M.; Marchant, J.; Ruchti, R.; Wayne, M.; Atac, M.; Baumbaugh, A.; Elias, J.E.; Romero, A.; Chrisman, D.; Park, J.; Adams, M.R.; Chung, M.; Goldberg, H.; Margulies, S.; Solomon, J.; Chaney, R.; Orgeron, J.; Armstrong, T.; Lewis, R.A.; Mitchell, G.S.; Moore, R.S.; Passaneau, J.; Smith, G.A.; Corcoran, M.; Adams, D.; Bird, F.; Fenker, H.; Regan, T.; Thomas, J. (Dept. of Physics, Purdue Univ., West Lafayette, IN (United States) Dept. of Physics, Univ. of Notre Dame, IN (United States) Fermilab, Batavia, IL (United States) Dept. of Physics, Univ. of California, Los Angeles, CA (United States) Dept. of Physics, Univ. of Illinois, Chicago, IL (United States) Dept. of Physics, Univ. of Texas, Richardson, TX (United States) Dept. of Physics, Pennsylvania State Univ., University Park, PA (United States) Dept. of Physics, Rice Univ

    1994-02-01

    A 96-channel, 3-superlayer, scintillating-fiber tracking system has been tested in a 5 GeV/c [pi][sup -] beam. The scintillating fibers were 830 [mu]m in diameter, spaced 850 [mu]m apart, and 4.3 m in length. They were coupled to 6 m long, clear fiber waveguides and finally to visible light photon counters. A spatial resolution of [approx]150 [mu]m for a double-layered ribbon was achieved with this tracking system. This first prototype of a charged-particle tracking system configured for the Solenoidal Detector Collaboration at the Superconducting Super Collider is a benchmark in verifying the expected number of photoelectrons from the fibers. (orig.)

  3. 1/12-Scale mixing interface visualization and buoyant particle release tests in support of Tank 241-SY-101 hydrogen mitigation

    Energy Technology Data Exchange (ETDEWEB)

    Eschbach, E.J.; Enderlin, C.W.

    1993-10-01

    In support of tank waste safety programs, visualization tests were performed in the 1/12-scale tank facility, using a low-viscosity simulant. The primary objective of the tests was to obtain video records of the transient jet-sludge interaction. The intent is that these videos will provide useful qualitative data for comparison with model predictions. Two tests were initially planned: mixing interface visualization (MIV) and buoyant particle release (BPR). Completion of the buoyant particle release test was set aside in order to complete additional MIV tests. Rheological measurements were made on simulant samples before testing, and the simulant was found to exhibit thixotropic behavior. Shear vane measurements were also made on an in-situ analog of the 1/12-scale tank simulant. Simulant shear strength has been observed to be time dependent. The primary objective of obtaining video records of jet-sludge interaction was satisfied, and the records yielded jet location information which may be of use in completing model comparisons. The modeling effort is not part of this task, but this report also discusses test specific instrumentation, visualization techniques, and shear vane instrumentation which would enable improved characterization of jet-sludge interaction and simulant characteristics.

  4. 1/12-Scale mixing interface visualization and buoyant particle release tests in support of Tank 241-SY-101 hydrogen mitigation

    International Nuclear Information System (INIS)

    Eschbach, E.J.; Enderlin, C.W.

    1993-10-01

    In support of tank waste safety programs, visualization tests were performed in the 1/12-scale tank facility, using a low-viscosity simulant. The primary objective of the tests was to obtain video records of the transient jet-sludge interaction. The intent is that these videos will provide useful qualitative data for comparison with model predictions. Two tests were initially planned: mixing interface visualization (MIV) and buoyant particle release (BPR). Completion of the buoyant particle release test was set aside in order to complete additional MIV tests. Rheological measurements were made on simulant samples before testing, and the simulant was found to exhibit thixotropic behavior. Shear vane measurements were also made on an in-situ analog of the 1/12-scale tank simulant. Simulant shear strength has been observed to be time dependent. The primary objective of obtaining video records of jet-sludge interaction was satisfied, and the records yielded jet location information which may be of use in completing model comparisons. The modeling effort is not part of this task, but this report also discusses test specific instrumentation, visualization techniques, and shear vane instrumentation which would enable improved characterization of jet-sludge interaction and simulant characteristics

  5. Effect of Particle Shape on Mechanical Behaviors of Rocks: A Numerical Study Using Clumped Particle Model

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Zhou, Chuang-bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied. PMID:23997677

  6. Effect of particle shape on mechanical behaviors of rocks: a numerical study using clumped particle model.

    Science.gov (United States)

    Rong, Guan; Liu, Guang; Hou, Di; Zhou, Chuang-Bing

    2013-01-01

    Since rocks are aggregates of mineral particles, the effect of mineral microstructure on macroscopic mechanical behaviors of rocks is inneglectable. Rock samples of four different particle shapes are established in this study based on clumped particle model, and a sphericity index is used to quantify particle shape. Model parameters for simulation in PFC are obtained by triaxial compression test of quartz sandstone, and simulation of triaxial compression test is then conducted on four rock samples with different particle shapes. It is seen from the results that stress thresholds of rock samples such as crack initiation stress, crack damage stress, and peak stress decrease with the increasing of the sphericity index. The increase of sphericity leads to a drop of elastic modulus and a rise in Poisson ratio, while the decreasing sphericity usually results in the increase of cohesion and internal friction angle. Based on volume change of rock samples during simulation of triaxial compression test, variation of dilation angle with plastic strain is also studied.

  7. Acceptance Test Data for BWXT Coated Particle Batches 93172B and 93173B—Defective IPyC and Pyrocarbon Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dyer, John A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schumacher, Austin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Skitt, Darren J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-08-01

    Coated particle batches J52O-16-93172B and J52O-16-93173B were produced by Babcock and Wilcox Technologies (BWXT) as part of the production campaign for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), but were not used in the final fuel composite. However, these batches may be used as demonstration production-scale coated particle fuel for other experiments. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93172A). Secondary upgrading by sieving was performed on the A-designated batches to remove particles with missing or very-thin buffer layers that were identified during previous analysis of the individual batches for defective IPyC, as reported in the acceptance test data report for the AGR-5/6/7 production batches [Hunn et al. 2017b]. The additionally-upgraded batches were designated by appending the letter B to the end of the batch number (e.g., 93172B).

  8. Study on effective particle diameters and coolability of particulate beds packed with irregular multi-size particles

    Energy Technology Data Exchange (ETDEWEB)

    Thakre, S.; Ma, W.; Kudinov, P.; Bechta, S. [Royal Institute of Technology, KTH. Div. of Nuclear Power Safety, Stockholm (Sweden)

    2013-08-15

    One of the key questions in severe accident research is the coolability of the debris bed, i.e., whether decay heat can be completely removed by the coolant flow into the debris bed. Extensive experimental and analytical work has been done to substantiate the coolability research. Most of the available experimental data is related to the beds packed with single size (mostly spherical) particles, and less data is available for multi-size/irregular-shape particles. There are several analytical models available, which rely on the mean particle diameter and porosity of the bed in their predictions. Two different types of particles were used to investigate coolability of particulate beds at VTT, Finland. The first type is irregular-shape Aluminum Oxide gravel particles whose sizes vary from 0.25 mm to 10 mm, which were employed in the STYX experiment programme (2001-2008). The second type is spherical beads of Zirconium silicate whose sizes vary between 0.8 mm to 1 mm, which were used in the COOLOCE tests (Takasuo et al., 2012) to study the effect of multi-dimensional flooding on coolability. In the present work, the two types of particles are used in the POMECO-FL and POMECO-HT test facility to obtain their effective particle diameters and dryout heat flux of the beds, respectively. The main idea is to check how the heaters' orientations (vertical in COOLOCE vs. horizontal in POMECO-HT) and diameters (6 mm in COOLOCE vs. 3 mm in POMECO-HT) affect the coolability (dryout heat flux) of the test beds. The tests carried out on the POMECO-FL facility using a bed packed with aluminum oxide gravel particles show the effective particle diameter of the gravel particles is 0.65 mm, by which the frictional pressure gradient can be predicted by the Ergun equation. After the water superficial velocity is higher than 0.0025 m/s, the pressure gradient is underestimated. The effective particle diameter of the zirconium particles is found as 0.8 mm. The dryout heat flux is measured on

  9. Study on effective particle diameters and coolability of particulate beds packed with irregular multi-size particles

    International Nuclear Information System (INIS)

    Thakre, S.; Ma, W.; Kudinov, P.; Bechta, S.

    2013-08-01

    One of the key questions in severe accident research is the coolability of the debris bed, i.e., whether decay heat can be completely removed by the coolant flow into the debris bed. Extensive experimental and analytical work has been done to substantiate the coolability research. Most of the available experimental data is related to the beds packed with single size (mostly spherical) particles, and less data is available for multi-size/irregular-shape particles. There are several analytical models available, which rely on the mean particle diameter and porosity of the bed in their predictions. Two different types of particles were used to investigate coolability of particulate beds at VTT, Finland. The first type is irregular-shape Aluminum Oxide gravel particles whose sizes vary from 0.25 mm to 10 mm, which were employed in the STYX experiment programme (2001-2008). The second type is spherical beads of Zirconium silicate whose sizes vary between 0.8 mm to 1 mm, which were used in the COOLOCE tests (Takasuo et al., 2012) to study the effect of multi-dimensional flooding on coolability. In the present work, the two types of particles are used in the POMECO-FL and POMECO-HT test facility to obtain their effective particle diameters and dryout heat flux of the beds, respectively. The main idea is to check how the heaters' orientations (vertical in COOLOCE vs. horizontal in POMECO-HT) and diameters (6 mm in COOLOCE vs. 3 mm in POMECO-HT) affect the coolability (dryout heat flux) of the test beds. The tests carried out on the POMECO-FL facility using a bed packed with aluminum oxide gravel particles show the effective particle diameter of the gravel particles is 0.65 mm, by which the frictional pressure gradient can be predicted by the Ergun equation. After the water superficial velocity is higher than 0.0025 m/s, the pressure gradient is underestimated. The effective particle diameter of the zirconium particles is found as 0.8 mm. The dryout heat flux is measured on

  10. Tests of a Particle Flow Algorithm with CALICE test beam data

    Czech Academy of Sciences Publication Activity Database

    Adloff, C.; Blaha, J.; Blaising, J.J.; Cvach, Jaroslav; Gallus, Petr; Havránek, Miroslav; Janata, Milan; Kvasnička, Jiří; Lednický, Denis; Marčišovský, Michal; Polák, Ivo; Popule, Jiří; Tomášek, Lukáš; Tomášek, Michal; Růžička, Pavel; Šícho, Petr; Smolík, Jan; Vrba, Václav; Zálešák, Jaroslav

    2011-01-01

    Roč. 6, č. 7 (2011), s. 1-15 ISSN 1748-0221 R&D Projects: GA MŠk LA09042; GA MŠk LA08032 Institutional research plan: CEZ:AV0Z10100502 Keywords : calorimeters * PFA * CALICE * calorimeter methods Subject RIV: BF - Elementary Particles and High Energy Physics Impact factor: 1.869, year: 2011 http://iopscience.iop.org/1748-0221/6/07/P07005

  11. Tests of crossed-wire position sensitive photomultipliers for scintillating fiber particle tracking

    International Nuclear Information System (INIS)

    Perdrisat, C.F.; Koechner, D.; Majewski, S.; Pourang, R.; Wilson, C.D.; Zorn, C.

    1995-01-01

    Several applications of two Hamamatsu position sensitive photomultiplier tubes to the detection of high energy particles with scintillating fibers are discussed. The PMTs are of the multiwire anode grid design, type R2486 and R4135. These tubes were tested with both single samples and arrays of 2 and 3 mm diameter scintillating fibers. Measurements of position resolution of the PMTs using either the charge digitization or the delay line readout techniques were made. The results indicate an intrinsic inability of the technique to reconstruct the actual position of a fiber on the photocathode when its location falls halfway between two grid wires. A way to overcome this limit is suggested. (orig.)

  12. Particle size determination

    International Nuclear Information System (INIS)

    Burr, K.J.

    1979-01-01

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

  13. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Rossoll, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)], E-mail: andreas.rossoll@epfl.ch; Weber, L. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland); Bourke, M.A.M. [Los Alamos National Laboratory (LANL), LANSCE-12, P.O. Box 1663, MS H805, Los Alamos, NM 87545 (United States); Dunand, D.C. [Northwestern University, Department of Materials Science and Engineering, Evanston, IL 60208 (United States); Mortensen, A. [Ecole Polytechnique Federale de Lausanne (EPFL), Laboratory for Mechanical Metallurgy, CH-1015 Lausanne (Switzerland)

    2008-10-15

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments.

  14. Tensile flow stress of ceramic particle-reinforced metal in the presence of particle cracking

    International Nuclear Information System (INIS)

    Mueller, R.; Rossoll, A.; Weber, L.; Bourke, M.A.M.; Dunand, D.C.; Mortensen, A.

    2008-01-01

    A simplified model is proposed to quantify the effect of damage in the form of particle cracking on the elastic and plastic behaviour of particle-reinforced metal matrix composites under uniaxial tensile loading: cracked particles are simply replaced, in a mean-field model, with as much matrix. Pure aluminium reinforced with 44 vol.% alumina particles, tested in tension and unloaded at periodic plastic deformations, is analysed by neutron diffraction during each reloading elastic step, at 30%, 50%, 70% and 90% of the tensile flow stress. The data give the evolution of the elastic matrix strains in the composite and also measure the progress of internal damage by particle cracking. The test gives (i) the evolution of the in situ matrix flow stress, and (ii) the evolution of load partitioning during elastic deformation with increasing composite damage. Predictions of the present model compare favourably with relevant results in the literature, and with results from the present neutron diffraction experiments

  15. Rotating drum tests of particle suspensions within a fines dispersion

    Science.gov (United States)

    Cabrera, Miguel Angel; Gollin, Devis; Kaitna, Roland; Wu, Wei

    2014-05-01

    Natural flows like mudflows, debris flow, and hyperconcentrated flows are commonly composed by a matrix of particles suspended in a viscous fluid. The nature of the interactions between particles immersed in a fluid is related to its size. While coarse particles (sand, gravel, and boulders) interact with each other or with the surrounding fluid, a dispersion of fine particles interacts with each other through colloidal forces or Brownian motion effects (Coussot and Piau, 1995, and Ancey and Jorrot, 2001). The predominance of one of the previous interactions defines the rheology of the flow. On this sense, experimental insight is required to validate the limits where the rheology of a dispersion of fines is valid. For this purpose, an experimental program in a rotating drum is performed over samples of sand, loess, and kaolin. The solid concentration and angular velocity of the rotating drum are varied. Height and normal loads are measured during flow. High-speed videos are performed to obtain the flow patterns of the mixtures. The experiments provide new laboratory evidence of granular mixture behaviour within an increased viscous fluid phase and its characterization. The results show an apparent threshold in terms of solid concentration, in which the mixtures started to behave as a shear-dependent material.

  16. Overview of particle physics

    International Nuclear Information System (INIS)

    Salam, A.

    1993-01-01

    This article presents an overview of the situation in particle physics and a prognosis of its future: ideas which have been tested or will soon be tested (standard model and the light Higgs particle), ideas whose time has not yet come (supersymmetry, supersymmetry and N=1 supergravity, right-left symmetry and preons, unification of gravity with other forces, anomaly-free supergravities, supersymmetry strings, string theory as the ''Theory of Everything'' (T.O.E.); passive and non accelerator experiments. 6 figs., 2 tabs

  17. In-pile test results of U-silicide or U-nitride coated U-7Mo particle dispersion fuel in Al

    Science.gov (United States)

    Kim, Yeon Soo; Park, J. M.; Lee, K. H.; Yoo, B. O.; Ryu, H. J.; Ye, B.

    2014-11-01

    U-silicide or U-nitride coated U-Mo particle dispersion fuel in Al (U-Mo/Al) was in-pile tested to examine the effectiveness of the coating as a diffusion barrier between the U-7Mo fuel kernels and Al matrix. This paper reports the PIE data and analyses focusing on the effectiveness of the coating in terms of interaction layer (IL) growth and general fuel performance. The U-silicide coating showed considerable success, but it also provided evidence for additional improvement for coating process. The U-nitride coated specimen showed largely inefficient results in reducing IL growth. From the test, important observations were also made that can be utilized to improve U-Mo/Al fuel performance. The heating process for coating turned out to be beneficial to suppress fuel swelling. The use of larger fuel particles confirmed favorable effects on fuel performance.

  18. In-pile test results of U-silicide or U-nitride coated U-7Mo particle dispersion fuel in Al

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yeon Soo, E-mail: yskim@anl.gov [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States); Park, J.M.; Lee, K.H.; Yoo, B.O. [Korea Atomic Energy Research Institute, 989-111 Daedeokdaero, Yuseong-gu, Daejeon 305-353 (Korea, Republic of); Ryu, H.J. [Dept. of Nuclear and Quantum Engineering, Korea Advanced Institute of Science and Technology, 291 Daehak-ro, Yuseong-gu, Daejeon 305-701 (Korea, Republic of); Ye, B. [Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439 (United States)

    2014-11-15

    U-silicide or U-nitride coated U-Mo particle dispersion fuel in Al (U-Mo/Al) was in-pile tested to examine the effectiveness of the coating as a diffusion barrier between the U-7Mo fuel kernels and Al matrix. This paper reports the PIE data and analyses focusing on the effectiveness of the coating in terms of interaction layer (IL) growth and general fuel performance. The U-silicide coating showed considerable success, but it also provided evidence for additional improvement for coating process. The U-nitride coated specimen showed largely inefficient results in reducing IL growth. From the test, important observations were also made that can be utilized to improve U-Mo/Al fuel performance. The heating process for coating turned out to be beneficial to suppress fuel swelling. The use of larger fuel particles confirmed favorable effects on fuel performance.

  19. Particle cosmology comes of age

    International Nuclear Information System (INIS)

    Turner, M.S.

    1988-01-01

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

  20. Particle cosmology comes of age

    International Nuclear Information System (INIS)

    Turner, M.S.

    1987-12-01

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

  1. Current status of personnel monitoring for beta particles

    International Nuclear Information System (INIS)

    Plato, P.; Miklos, J.

    1983-01-01

    From 1975 to 1982, a concerted effort was made to develop a uniform procedure to test the performance of personnel dosimetry processors throughout the United States. The heart of this effort is a standard developed by the Health Physics Society Standards Committee (HPSSC) and adopted by the American National Standards Institute (ANSI) as ANSI N13.11-1982. The US Nuclear Regulatory Commission (NRC) sponsored a five year pilot study of this Standard which included three trial tests in which approximately 80 dosimetry processors participated. The Standard has made several contributions to the art and science of personnel monitoring for beta particles. First, the Standard defines test categories for beta particles and mixtures of beta particles plus gamma rays in addition to test categories for other types of radiation. Second, it defines a reference beta-particle source for test purposes. Third, it provides test criteria which are used to determine acceptable performance by a processor. The pilot study provided information on the state of the art of personnel monitoring within the bounds of the Standard. In addition, since the pilot study was advertised as the forerunner of a future mandatory certification program for dosimetry processors throughout the United States, considerable attention was given to personnel monitoring in general, and beta particles in particular. This paper discusses specific contibutions of the HPSSC/ANSI Standard and the pilot study to beta-particle dosimetry. The results of the three tests of the pilot study are summarized. The paper also amplifies on the needs to define the monitoring particle sources clearly

  2. Optimation of particle size and composition in fabrication of granite particle composite floortiles

    International Nuclear Information System (INIS)

    Budiarto; Parikin; Mohammad-Dani

    2004-01-01

    Granite particle composite floortile materials, that have epoxy matrix, may be utilized as water resist and ductile materials. The utility of composite materials for industrial households is, however, very important and very promising indeed. Starting from powdering the granite refuges into particles of 100, 140 and 200 in mesh, the powder was mixed by epoxy containing versamid hardener and stirred till highly homogenized. Specimens were mould in glass frame and dried in ambient temperature for 48 hours. The specimens were prepared into certain dimensions, conformed to testing needs: hardness, density, compression and bending. The hardness and density data show clearly the value change of particulate composition (34, 40, 50 and 70) and matrix (66, 60, 50 and 30) as well. From bending and compression tests, the optimum grain size (μm) and composition (%) of granite particles reveal between the number of 120-123 and 55-61 respectively. The accurate point of the values can be determined by using differential method. As conclusion, for the better mechanical properties of granite particles composite floortiles, the grains should be 121 in μm and 57% composition of granite particles

  3. Optimized qualification protocol on particle cleanliness for EUV mask infrastructure

    Science.gov (United States)

    van der Donck, J. C. J.; Stortelder, J. K.; Derksen, G. B.

    2011-11-01

    With the market introduction of the NXE:3100, Extreme Ultra Violet Lithography (EUVL) enters a new stage. Now infrastructure in the wafer fabs must be prepared for new processes and new materials. Especially the infrastructure for masks poses a challenge. Because of the absence of a pellicle reticle front sides are exceptionally vulnerable to particles. It was also shown that particles on the backside of a reticle may cause tool down time. These effects set extreme requirements to the cleanliness level of the fab infrastructure for EUV masks. The cost of EUV masks justifies the use of equipment that is qualified on particle cleanliness. Until now equipment qualification on particle cleanliness have not been carried out with statistically based qualification procedures. Since we are dealing with extreme clean equipment the number of observed particles is expected to be very low. These particle levels can only be measured by repetitively cycling a mask substrate in the equipment. Recent work in the EUV AD-tool presents data on added particles during load/unload cycles, reported as number of Particles per Reticle Pass (PRP). In the interpretation of the data, variation by deposition statistics is not taken into account. In measurements with low numbers of added particles the standard deviation in PRP number can be large. An additional issue is that particles which are added in the routing outside the equipment may have a large impact on the testing result. The number mismatch between a single handling step outside the tool and the multiple cycling in the equipment makes accuracy of measurements rather complex. The low number of expected particles, the large variation in results and the combined effect of added particles inside and outside the equipment justifies putting good effort in making a test plan. Without a proper statistical background, tests may not be suitable for proving that equipment qualifies for the limiting cleanliness levels. Other risks are that a

  4. Equivalence Testing of Complex Particle Size Distribution Profiles Based on Earth Mover's Distance.

    Science.gov (United States)

    Hu, Meng; Jiang, Xiaohui; Absar, Mohammad; Choi, Stephanie; Kozak, Darby; Shen, Meiyu; Weng, Yu-Ting; Zhao, Liang; Lionberger, Robert

    2018-04-12

    Particle size distribution (PSD) is an important property of particulates in drug products. In the evaluation of generic drug products formulated as suspensions, emulsions, and liposomes, the PSD comparisons between a test product and the branded product can provide useful information regarding in vitro and in vivo performance. Historically, the FDA has recommended the population bioequivalence (PBE) statistical approach to compare the PSD descriptors D50 and SPAN from test and reference products to support product equivalence. In this study, the earth mover's distance (EMD) is proposed as a new metric for comparing PSD particularly when the PSD profile exhibits complex distribution (e.g., multiple peaks) that is not accurately described by the D50 and SPAN descriptor. EMD is a statistical metric that measures the discrepancy (distance) between size distribution profiles without a prior assumption of the distribution. PBE is then adopted to perform statistical test to establish equivalence based on the calculated EMD distances. Simulations show that proposed EMD-based approach is effective in comparing test and reference profiles for equivalence testing and is superior compared to commonly used distance measures, e.g., Euclidean and Kolmogorov-Smirnov distances. The proposed approach was demonstrated by evaluating equivalence of cyclosporine ophthalmic emulsion PSDs that were manufactured under different conditions. Our results show that proposed approach can effectively pass an equivalent product (e.g., reference product against itself) and reject an inequivalent product (e.g., reference product against negative control), thus suggesting its usefulness in supporting bioequivalence determination of a test product to the reference product which both possess multimodal PSDs.

  5. Laser and Particle Guiding Micro-Elements for Particle Accelerators

    CERN Document Server

    Plettner, Tomas; Spencer, James; Wisdom, Jeffrey

    2005-01-01

    Laser driven particle accelerators based on the current generation of lasers will require sub-micron control of the laser field as well as precise beam guiding. Hence the fabrication techniques that allow integrating both elements into an accelerator-on-chip format become critical for the success of such particle accelerators. Micromachining technology for silicon has been shown to be one such feasible technology in PAC2003 but with a variety of complications on the laser side. Fortunately, in recent years the fabrication of transparent ceramics has become an interesting technology that could be applied for laser-particle accelerators in several ways. We discuss this area, its advantages such as the range of materials it provides and various ways to implement it followed by some different test examples that have been considered. One important goal of this approach is an integrated system that could avoid the necessity of having to inject either laser or particle pulses into these structures.

  6. Ice-condenser aerosol tests

    International Nuclear Information System (INIS)

    Ligotke, M.W.; Eschbach, E.J.; Winegardner, W.K.

    1991-09-01

    This report presents the results of an experimental investigation of aerosol particle transport and capture using a full-scale height and reduced-scale cross section test facility based on the design of the ice compartment of a pressurized water reactor (PWR) ice-condenser containment system. Results of 38 tests included thermal-hydraulic as well as aerosol particle data. Particle retention in the test section was greatly influenced by thermal-hydraulic and aerosol test parameters. Test-average decontamination factor (DF) ranged between 1.0 and 36 (retentions between ∼0 and 97.2%). The measured test-average particle retentions for tests without and with ice and steam ranged between DF = 1.0 and 2.2 and DF = 2.4 and 36, respectively. In order to apparent importance, parameters that caused particle retention in the test section in the presence of ice were steam mole fraction (SMF), noncondensible gas flow rate (residence time), particle solubility, and inlet particle size. Ice-basket section noncondensible flows greater than 0.1 m 3 /s resulted in stable thermal stratification whereas flows less than 0.1 m 3 /s resulted in thermal behavior termed meandering with frequent temperature crossovers between flow channels. 10 refs., 66 figs., 16 tabs

  7. The particle swarm optimization algorithm applied to nuclear systems surveillance test planning

    International Nuclear Information System (INIS)

    Siqueira, Newton Norat

    2006-12-01

    This work shows a new approach to solve availability maximization problems in electromechanical systems, under periodic preventive scheduled tests. This approach uses a new Optimization tool called PSO developed by Kennedy and Eberhart (2001), Particle Swarm Optimization, integrated with probabilistic safety analysis model. Two maintenance optimization problems are solved by the proposed technique, the first one is a hypothetical electromechanical configuration and the second one is a real case from a nuclear power plant (Emergency Diesel Generators). For both problem PSO is compared to a genetic algorithm (GA). In the experiments made, PSO was able to obtain results comparable or even slightly better than those obtained b GA. Therefore, the PSO algorithm is simpler and its convergence is faster, indicating that PSO is a good alternative for solving such kind of problems. (author)

  8. Evaluation of Fracture Stress for the SiC Layer of TRISO-Coated Fuel Particles by A Modified Crush Testing

    International Nuclear Information System (INIS)

    Byun, Thak Sang; Kim, Jin Weon; Miller, James Henry; Snead, Lance Lewis; Hunn, John D.

    2010-01-01

    Fracture stress data for the chemical vapor deposition (CVD) SiC coatings of tri-isotropic (TRISO) carbon/silicon carbide coated fuel particles were obtained using a newly developed testing and evaluation method, and their relationship with microstructure investigated. A crush testing technique using a blanket foil at load-transferring contact has been developed for hemispherical shell SiC specimens based on finite element (FE) analysis results. Mean fracture stress varied with test material in the range of 330-650 MPa, and was connected to the combined characteristics of inner surface roughness and porosity.

  9. Anomalous loss of DT alpha particles in the Tokamak Fusion Test Reactor

    Energy Technology Data Exchange (ETDEWEB)

    Herrmann, Hans W. [Princeton Univ., NJ (United States)

    1997-09-01

    An escaping alpha collector probe has been developed for TFTR`s DT phase. Energy distributions of escaping alphas have been determined by measuring the range of α-particles implanted into nickel foils located within the alpha collector. Results at 1.0 MA of plasma current are in good agreement with predictions for first orbit alpha loss. Results at 1.8 MA, however, show a significant anomalous loss of partially thermalized alphas (in addition to the expected first orbit loss), which is not observed with the lost alpha scintillator detectors in DT plasmas, but does resemble the anomalous delayed loss seen in DD plasmas. None of the candidate explanations proposed thus far are fully consistent with the anomalous loss observations. An experiment designed to study the effect of plasma major radius shifts on α-particle loss has led to a better understanding of α-particle dynamics in tokamaks. Intuitively, one might suppose that confined marginally passing α-particles forced to move toward higher magnetic field during an inward major radius shift (i.e., compression) would mirror and become trapped particles, leading to increased alpha loss. Such an effect was looked for during the shift experiment, however, no significant changes in alpha loss to the 90° lost alpha scintillator detector were observed during the shifts. It is calculated that the energy gained by an α-particle during the inward shift is sufficient to explain this result. However, an unexpected loss of partially thermalized α-particles near the passing/trapped boundary was observed to occur between inward and outward shifts at an intermediate value of plasma current (1.4 MA). This anomalous loss feature is not yet understood.

  10. Sampling of solid particles in clouds

    International Nuclear Information System (INIS)

    Feuillebois, F.; Lasek, A.; Scibilia, M.F.

    1986-01-01

    This paper is concerned with the sampling of small solid particles from clouds by an airborne apparatus to be mounted on an airplane for meteorological investigations. In the airborne experiment the particles entering the test tube should be as representative as possible of the upstream conditions ahead of the plane, in the real cloud. Due to the inertia of the particles, the proportion of the different sizes of particles entering the test tube depends on the location of the tube mouth. We present a method of calculating the real concentration in particles of different sizes, using the results of measurements executed during the flight of an airplane in a cloud. Two geometries are considered: the nose of the airplane, represented schematically by a hemisphere, and a wing represented by a (2D) Joukowski profile which matches well a NACA 0015 profile on its leading edge

  11. Small particles big effect? - Investigating ice nucleation abilities of soot particles

    Science.gov (United States)

    Mahrt, Fabian; David, Robert O.; Lohmann, Ulrike; Stopford, Chris; Wu, Zhijun; Kanji, Zamin A.

    2017-04-01

    Atmospheric soot particles are primary particles produced by incomplete combustion of biomass and/or fossil fuels. Thus soot mainly originates from anthropogenic emissions, stemming from combustion related processes in transport vehicles, industrial and residential uses. Such soot particles are generally complex mixtures of black carbon (BC) and organic matter (OM) (Bond et al., 2013; Petzold et al., 2013), depending on the sources and the interaction of the primary particles with other atmospheric matter and/or gases BC absorbs solar radiation having a warming effect on global climate. It can also act as a heterogeneous ice nucleating particle (INP) and thus impact cloud-radiation interactions, potentially cooling the climate (Lohmann, 2002). Previous studies, however, have shown conflicting results concerning the ice nucleation ability of soot, limiting the ability to predict its effects on Earth's radiation budget. Here we present a laboratory study where we systematically investigate the ice nucleation behavior of different soot particles. Commercial soot samples are used, including an amorphous, industrial carbon frequently used in coatings and coloring (FW 200, Orion Engineered Carbons) and a fullerene soot (572497 ALDRICH), e.g. used as catalyst. In addition, we use soot generated from a propane flame Combustion Aerosol Standard Generator (miniCAST, JING AG), as a proxy for atmospheric soot particles. The ice nucleation ability of these soot types is tested on size-selected particles for a wide temperature range from 253 K to 218 K, using the Horizontal Ice Nucleation Chamber (HINC), a Continuous Flow Diffusion Chamber (CFDC) (Kanji and Abbatt, 2009). Ice nucleation results from these soot surrogates will be compared to chemically more complex real world samples, collected on filters. Filters will be collected during the 2016/2017 winter haze periods in Beijing, China and represent atmospheric soot particles with sources from both industrial and residential

  12. Counting statistics of many-particle quantum walks

    Science.gov (United States)

    Mayer, Klaus; Tichy, Malte C.; Mintert, Florian; Konrad, Thomas; Buchleitner, Andreas

    2011-06-01

    We study quantum walks of many noninteracting particles on a beam splitter array as a paradigmatic testing ground for the competition of single- and many-particle interference in a multimode system. We derive a general expression for multimode particle-number correlation functions, valid for bosons and fermions, and infer pronounced signatures of many-particle interferences in the counting statistics.

  13. Counting statistics of many-particle quantum walks

    International Nuclear Information System (INIS)

    Mayer, Klaus; Tichy, Malte C.; Buchleitner, Andreas; Mintert, Florian; Konrad, Thomas

    2011-01-01

    We study quantum walks of many noninteracting particles on a beam splitter array as a paradigmatic testing ground for the competition of single- and many-particle interference in a multimode system. We derive a general expression for multimode particle-number correlation functions, valid for bosons and fermions, and infer pronounced signatures of many-particle interferences in the counting statistics.

  14. First test model of the optical microscope which images the whole vertical particle tracks without any depth scanning

    International Nuclear Information System (INIS)

    Soroko, L.M.

    2001-01-01

    The first test model of the optical microscope which produces the in focus image of the whole vertical particle track without depth scanning is described. The in focus image of the object consisting of the linear array of the point-like elements was obtained. A comparison with primary out of focus image of such an object has been made

  15. IUTAM symposium on hydrodynamic diffusion of suspended particles

    Energy Technology Data Exchange (ETDEWEB)

    Davis, R.H. [ed.

    1995-12-31

    Hydrodynamic diffusion refers to the fluctuating motion of nonBrownian particles (or droplets or bubbles) which occurs in a dispersion due to multiparticle interactions. For example, in a concentrated sheared suspension, particles do not move along streamlines but instead exhibit fluctuating motions as they tumble around each other. This leads to a net migration of particles down gradients in particle concentration and in shear rate, due to the higher frequency of encounters of a test particle with other particles on the side of the test particle which has higher concentration or shear rate. As another example, suspended particles subject to sedimentation, centrifugation, or fluidization, do not generally move relative to the fluid with a constant velocity, but instead experience diffusion-like fluctuations in velocity due to interactions with neighboring particles and the resulting variation in the microstructure or configuration of the suspended particles. In flowing granular materials, the particles interact through direct collisions or contacts (rather than through the surrounding fluid); these collisions also cause the particles to undergo fluctuating motions characteristic of diffusion processes. Selected papers are indexed separately for inclusion in the Energy Science and Technology Database.

  16. Scattering of spinning test particles by gravitational plane waves

    International Nuclear Information System (INIS)

    Bini, D.; Gemelli, G.

    1997-01-01

    The authors study the motion of spinning particles in the gravitational plane-wave background and discuss particular solutions under a suitable choice of supplementary conditions. An analysis of the discontinuity of the motion across the wavefront is presented too

  17. Particle Physics and Astronomy Research Council (PPARC) members, United Kingdom, visiting the ATLAS semiconductor tracker (SCT) module tests.

    CERN Multimedia

    Patrice Loïez

    2002-01-01

    Photo 01: Mr Peter Warry, PPARC Chairman, Victrex Plc, United Kingdom visiting the ATLAS SCT module tests with Dr Joleen Pater, SCT (Manchester). Photo 02: PPARC Council Members, United Kingdom, visiting the ATLAS SCT module tests. L.t to r.: Mrs Judith Scott, Chief Executive, British Computer Society, Prof. George Efstathiou, Institute of Astronomy, University of Cambridge, Mr Peter Warry, PPARC Chairman, Victrex Plc, Prof. Martin Ward, Director X-Ray Astronomy, of Leicester, Prof. James Stirling, Director, Institute for Particle Physics Phenomenology, University of Durham and Prof. Brian Foster, University of Bristol.

  18. Obtaining of a rapid diagnostic test for Cholera, based on latex particles coupled with a monoclonal antibody against Vibrio cholera O1 lipopolysaccharide

    Directory of Open Access Journals (Sweden)

    Fátima Reyes-López

    2015-08-01

    Full Text Available Cholera is an acute contagious intestinal disease caused by ingestion of food or water contaminated with O1 and O139 serotypes of the bacterium Vibrio cholerae. Cholera is characterized by abundant secretory diarrhea leading to dehydration. Death occurs within hours without treatment, so early diagnosis is very important, especially at the beginning of the disease, because it is difficult to differentiate from other acute diarrheal diseases. The diagnostic golden test is the stool culture; however, it does not guarantee a rapid detection of the disease. Rapid tests have been recently developed; they are based on test strips and agglutination with latex particles, which are very effective, but difficult to acquire for their high prices. The objective of this research was to obtain a quick assay based on latex particles coupled with a monoclonal antibody (mAb against V. cholerae O1 lipopolysaccharide obtained in Finlay Institute. Latex particles of 0.8 µm were used in a 10% suspension, and they were coupled to the mAb (0.25 mg/ml for 2 hours at 37°C. The sensitivity, specificity and performance were evaluated in 84 stool samples from patients with presumptive diagnosis of cholera. The diagnostic test obtained showed no cross-reactivity against no-O1 strains and other enteropathogens. Latex diagnostic test showed values of sensitivity, specificity and efficacy of 97.87; 97.29 and 97.6% respectively, very similar to the commercial diagnostic test CTK- Biotech. The latex reagent obtained can be used in the rapid diagnosis of the disease.

  19. Diffusion of test particles in stochastic magnetic fields in the percolative regime

    International Nuclear Information System (INIS)

    Neuer, Marcus; Spatschek, Karl H.

    2006-01-01

    For stochastic magnetic flux functions with percolative contours the test particle transport is investigated. The calculations make use of the stochastic Liouville approach. They start from the so-called A-Langevin equations, including stochastic magnetic field components and binary collisions. Using the decorrelation trajectory method, a relation between the Lagrangian velocity correlation function and the Eulerian magnetic field correlation is derived and introduced into the Green-Kubo formalism. Finite Larmor radius effects are included. Interesting results are presented in the percolation regime corresponding to high Kubo numbers. Previous results are found to be limiting cases for small Kubo numbers. For different percolative scenarios the diffusion is analyzed and strong influences of the percolative structures on the transport scaling are found. The finite Larmor radius effects are discussed in detail. Numerical simulations of the A-Langevin equation confirm the semianalytical predictions

  20. Analysis of irradiation-induced stresses in coating layers of coated fuel particles for the High Temperature Engineering Test Reactor (HTTR)

    International Nuclear Information System (INIS)

    Hayashi, Kimio; Kikuchi, Teruo; Fukuda, Kousaku; Sato, Sadao; Toyota, Junji; Shiozawa, Shusaku; Sawa, Kazuhiro; Kashimura, Satoru.

    1991-07-01

    Irradiation-induced stresses in coating layers of coated fuel particles were analyzed by the MICROS-2 code for the fuels of the High Temperature Engineering Test Reactor (HTTR) under its operating conditions. The analyses were made on the standard core fuel (A-type) and the test fuels comprising the advanced SiC-coated particle fuel (B-1 type) and the ZrC-coated particle fuel (B-2 type). For the B-1 type fuel, the stresses were relieved due to the thicker buffer and SiC layers than for the A type fuel. The slightly decreased thickness of the fourth layer for the B-1 type than for the A type fuel had no significant effect on the stresses. As for the B-2 type fuel, almost the same results as for the B-1 type were obtained under an assumption that the ZrC layer as well as the SiC layer undergoes negligible dimension change within the analysis conditions. The obtained results indicated that the B-1 and B-2 type fuels are better than the A type fuel in terms of integrity against the irradiation-induced stresses. Finally, research subjects for development of the analysis code on the fuel behavior are discussed. (author)

  1. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    International Nuclear Information System (INIS)

    Chiriac, L.B.; Trandafir, D.L.; Turcu, R.V.F.; Todea, M.; Simon, S.

    2016-01-01

    Highlights: • Dysprosium containing silica microparticles obtained by freeze and spray drying. • Higher structural units interconnection achieved in freeze vs. spray dried samples. • Dy occurance on the outermost layer of the microparticles evidenced by XPS. • Enhanced MRI contrast observed for freeze dried samples with 5% mol Dy_2O_3. - Abstract: The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, "2"9Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T_1 and RARE-T_2 protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T_2-weighted MRI contrast properties.

  2. Development of Coated Particle Fuel Technology

    International Nuclear Information System (INIS)

    Cho, Moon Sung; Kim, B. G.; Kim, Y. K.

    2009-04-01

    UO 2 kernel fabrication technology was developed at the lab sacle(20∼30g-UO 2 /batch). The GSP technique, modified method of sol-gel process, was used in the preparation of spherical ADU gel particle and these particles were converted to UO 3 and UO 2 phases in calcination furnace and sintering furnace respectively. Based on the process variables optimized using simulant kernels in 1-2 inch beds, SiC TRISO-coated particles were fabricated using UO 2 kernel. Power densities of TRISO coated particle fuels and gamma heat of the tubes are calculated as functions of vertical location of the fuel specimen in the irradiation holes by using core physics codes, MCNP and Helios. A finite model was developed for the calculations of temperatures and stresses of the specimen and the irradiation tubes. Dimensions of the test tubes are determined based on the temperatures and stresses as well as the gamma heat generated at the given condition. 9 modules of the COPA code (MECH, FAIL, TEMTR, TEMBL, TEMPEB, FPREL, MPRO, BURN, ABAQ), the MECH, FAIL, TEMTR, TEMBL, TEMPEB, and FPREL were developed. The COPA-FPREL was verified through IAEA CRP-6 accident benchmarking problems. KAERI participated in the round robin test of IAEA CRP-6 program to characterize the diameter, sphericity, coating thickness, density and anisotropy of coated particles provided by Korea, USA and South Africa. The inspection and test plan describing specifications and inspection method of coated particles was developed to confirm the quality standard of coated particles. The quality inspection instructions were developed for the inspection of coated particles by particle size analyzer, density inspection of coating layers by density gradient column, coating thickness inspection by X-ray, and inspection of optical anistropy factor of PyC layer. The quality control system for the TRISO-coated particle fuel was derived based on the status of quality control systems of other countries

  3. Shear-limited test particle diffusion in 2-dimensional plasmas

    International Nuclear Information System (INIS)

    Anderegg, Francois; Driscoll, C. Fred; Dubin, Daniel H.E.

    2002-01-01

    Measurements of test-particle diffusion in pure ion plasmas show 2D enhancements over the 3D rates, limited by shear in the plasma rotation ω E (r). The diffusion is due to 'long-range' ion-ion collisions in the quiescent, steady-state Mg + plasma. For short plasma length L p and low shear S≡r∂ω E /∂r, thermal ions bounce axially many times before shear separates them in θ, so the ions move in (r,θ) as bounce averaged 'rods' of charge (i.e. 2D point vortices). Experimentally, we vary the number of bounces over the range 0.2≤N b ≤10,000. For long plasmas with N b ≤1, we observe diffusion in quantitative agreement with the 3D theory of long-range ExB drift collisions. For shorter plasmas or lower shear, with N b >1, we measure diffusion rates enhanced by up to 100x. For exceedingly small she0ar, i.e. N b ≥1000, we observe diffusion rates consistent with the Taylor-McNamara estimates for a shear-free thermal plasma. Overall, the data shows fair agreement with Dubin's new theory of 2D diffusion in shear, which predicts an enhancement of D 2D /D 3D ≅N b up to the Taylor-McNamara limit

  4. Documentation of tests on particle size methodologies for laser diffraction compared to traditional sieving and sedimentation analysis

    DEFF Research Database (Denmark)

    Rasmussen, Charlotte; Dalsgaard, Kristian

    Sieving and sedimentation analyses by pipette or hydrometer are historically the traditional methods for determining particle size distributions (PSD). A more informative and faster alternative has for years been laser diffraction (LD). From 2003 to 2013 the authors of this paper have worked...... intensively with PSD and performed various tests and investigations, using LD, sedimentation (by pipette) and sieving. The aim was to improve and understand the relationship between these various techniques, pre-treatment effects and preferably find a unifying correlation factor. As a result, method...... comparisons of LD and sieving/sedimentation are difficult, as LD is a 3D optical volume measurement, sieving is a 2D width measurement, and sedimentation is density dependent. Platy particles like clay are generally measured to be coarser than traditional methods when LD is used. For LD the clay...

  5. Test Particle Simulations of Electron Injection by the Bursty Bulk Flows (BBFs) using High Resolution Lyon-Feddor-Mobarry (LFM) Code

    Science.gov (United States)

    Eshetu, W. W.; Lyon, J.; Wiltberger, M. J.; Hudson, M. K.

    2017-12-01

    Test particle simulations of electron injection by the bursty bulk flows (BBFs) have been done using a test particle tracer code [1], and the output fields of the Lyon-Feddor-Mobarry global magnetohydro- dynamics (MHD) code[2]. The MHD code was run with high resolu- tion (oct resolution), and with specified solar wind conditions so as to reproduce the observed qualitative picture of the BBFs [3]. Test par- ticles were injected so that they interact with earthward propagating BBFs. The result of the simulation shows that electrons are pushed ahead of the BBFs and accelerated into the inner magnetosphere. Once electrons are in the inner magnetosphere they are further energized by drift resonance with the azimuthal electric field. In addition pitch angle scattering of electrons resulting in the violation conservation of the first adiabatic invariant has been observed. The violation of the first adiabatic invariant occurs as electrons cross a weak magnetic field region with a strong gradient of the field perturbed by the BBFs. References 1. Kress, B. T., Hudson,M. K., Looper, M. D. , Albert, J., Lyon, J. G., and Goodrich, C. C. (2007), Global MHD test particle simulations of ¿ 10 MeV radiation belt electrons during storm sudden commencement, J. Geophys. Res., 112, A09215, doi:10.1029/2006JA012218. Lyon,J. G., Fedder, J. A., and Mobarry, C.M., The Lyon- Fedder-Mobarry (LFM) Global MHD Magnetospheric Simulation Code (2004), J. Atm. And Solar-Terrestrial Phys., 66, Issue 15-16, 1333- 1350,doi:10.1016/j.jastp. Wiltberger, Merkin, M., Lyon, J. G., and Ohtani, S. (2015), High-resolution global magnetohydrodynamic simulation of bursty bulk flows, J. Geophys. Res. Space Physics, 120, 45554566, doi:10.1002/2015JA021080.

  6. Current status of personnel monitoring for β particles

    International Nuclear Information System (INIS)

    Plato, P.; Miklos, J.

    1984-01-01

    From 1975 to 1982, a concerted effort was made to develop a uniform procedure to test the performance of personnel dosimetry processors throughout the United States. The heart of this effort is a standard developed by the Health Physics Society Standards Committee (HPSSC) and adopted by the American National Standards Institute (ANSI) as ANSI N13.11-1982. The US Nuclear Regulatory Commission (NRC) sponsored a five year pilot study of this Standard which included three trial tests in which approximately 80 dosimetry processors participated. This paper addresses two major questions. First, what have the HPSSC/ANSI Standard and the NRC-sponsored pilot study contributed toward improvements in personnel monitoring for β particles. Second, what additional improvements are necessary. The Standard defines test categories for β particles and mixtures of β particles plus γ rays in addition to test categories for other types of radiation. It also defines a reference β-particle source for test purposes. Third, it provides test criteria which are used to determine acceptable performance by a processor. The pilot study provided information on the state of the art of personnel monitoring within the bounds of the Standard. In addition, since the pilot study was advertised as the forerunner of a future mandatory certification program for dosimetry processors throughout the United States, considerable attention was given to personnel monitoring in general, and β particles in particular, that otherwise would have been given to other squeaky wheels. The results of the three tests of the pilot study are summarized. The paper also amplifies on the needs to define the monitoring problems of the work place and to define appropriate β-particle sources clearly

  7. Dispersion of Bed Load Particles

    OpenAIRE

    SAWAI, Kenji

    1987-01-01

    The motion of bed load particles is so irregular that they disperse remarkably with time.In this study, some flume tests using painted tracer particles were carried out, in which thedispersive property of tracers changed variously with sediment feed rate.In analysing this process, a stochastic simulation model is proposed where it is discussedabout the degree of exposure of individual particle near the bed surface and about the variationof its pick up rate. The exponential distribution of ste...

  8. Innermost stable circular orbit of spinning particle in charged spinning black hole background

    Science.gov (United States)

    Zhang, Yu-Peng; Wei, Shao-Wen; Guo, Wen-Di; Sui, Tao-Tao; Liu, Yu-Xiao

    2018-04-01

    In this paper we investigate the innermost stable circular orbit (ISCO) (spin-aligned or anti-aligned orbit) for a classical spinning test particle with the pole-dipole approximation in the background of Kerr-Newman black hole in the equatorial plane. It is shown that the orbit of the spinning particle is related to the spin of the test particle. The motion of the spinning test particle will be superluminal if its spin is too large. We give an additional condition by considering the superluminal constraint for the ISCO in the black hole backgrounds. We obtain numerically the relations between the ISCO and the properties of the black holes and the test particle. It is found that the radius of the ISCO for a spinning test particle is smaller than that of a nonspinning test particle in the black hole backgrounds.

  9. Accelerated tests for the soft error rate determination of single radiation particles in components of terrestrial and avionic electronic systems

    International Nuclear Information System (INIS)

    Flament, O.; Baggio, J.

    2010-01-01

    This paper describes the main features of the accelerated test procedures used to determine reliability data of microelectronics devices used in terrestrial environment.This paper focuses on the high energy particle test that could be performed through spallation neutron source or quasi-mono-energetic neutron or proton. Improvements of standards are illustrated with respect to the state of the art of knowledge in radiation effects and scaling down of microelectronics technologies. (authors)

  10. Development of RFQ particle dynamics simulation tools and validation with beam tests

    Energy Technology Data Exchange (ETDEWEB)

    Maus, Johannes M.

    2010-07-01

    Two different strategies of designing RFQs have been introduced. The analytic description of the electric fields inside the quadrupole channel has been derived and the two term simplification was shown as well as the limitation of these approaches. The main work of this thesis was the implementation and analysis of a multigrid Poisson solver to describe the potential and electric field of RFQs which are needed to simulate the particle dynamics accurately. The main two ingredients of a multigrid Poisson solver are the ability of a Gauss-Seidel iteration method to smooth the error of an approximation within a few iteration steps and the coarse grid principle. The smoothing corresponds to a damping of the high frequency components of the error. After the smoothing, the error term can well be approximated on a coarser grid in which the low frequency components of the error on the fine grid are converted to high frequency errors on the coarse grid which can be damped further with the same Gauss-Seidel method. After implementation, the multigrid Poisson solver was analyzed using two different type of test problems: with and without a charge density. As a charge density, a homogeneously charged ball and cylinder were used to represent the bunched and unbunched beam and placed inside a quadruple channel. The solver showed a good performance. Next, the performance of the solver to calculate the external potentials (and fields) of RFQs was analyzed. Closing the analysis of the external field, the transmission and fraction of accelerated particles of the set of 12 RFQs for the two different methods were shown. In the last chapter of this thesis some experimental work on the MAFF (Munich Accelerator for Fission Fragments) IH-RFQ is described. The MAFF RFQ was designed to accelerate very neutron-rich fission fragments for various experiments. The machine was assembled in Frankfurt and a beam test stand was built. As a part of this thesis the shunt impedance of the structure was

  11. Development of RFQ particle dynamics simulation tools and validation with beam tests

    International Nuclear Information System (INIS)

    Maus, Johannes M.

    2010-01-01

    Two different strategies of designing RFQs have been introduced. The analytic description of the electric fields inside the quadrupole channel has been derived and the two term simplification was shown as well as the limitation of these approaches. The main work of this thesis was the implementation and analysis of a multigrid Poisson solver to describe the potential and electric field of RFQs which are needed to simulate the particle dynamics accurately. The main two ingredients of a multigrid Poisson solver are the ability of a Gauss-Seidel iteration method to smooth the error of an approximation within a few iteration steps and the coarse grid principle. The smoothing corresponds to a damping of the high frequency components of the error. After the smoothing, the error term can well be approximated on a coarser grid in which the low frequency components of the error on the fine grid are converted to high frequency errors on the coarse grid which can be damped further with the same Gauss-Seidel method. After implementation, the multigrid Poisson solver was analyzed using two different type of test problems: with and without a charge density. As a charge density, a homogeneously charged ball and cylinder were used to represent the bunched and unbunched beam and placed inside a quadruple channel. The solver showed a good performance. Next, the performance of the solver to calculate the external potentials (and fields) of RFQs was analyzed. Closing the analysis of the external field, the transmission and fraction of accelerated particles of the set of 12 RFQs for the two different methods were shown. In the last chapter of this thesis some experimental work on the MAFF (Munich Accelerator for Fission Fragments) IH-RFQ is described. The MAFF RFQ was designed to accelerate very neutron-rich fission fragments for various experiments. The machine was assembled in Frankfurt and a beam test stand was built. As a part of this thesis the shunt impedance of the structure was

  12. Non-destructive testing: magnetizing equipment for magnetic particle inspection

    International Nuclear Information System (INIS)

    1975-07-01

    Magnetizing equipment for magnetic particle inspection serves to produce a magnetic field of suitable size and direction in a workpiece under examination. The characteristic parameters of this equipment are given in this standard along with their method of determination if this is necessary. (orig./AK) [de

  13. Suspending Zeolite Particles In Tanks

    International Nuclear Information System (INIS)

    Poirier, M.R.

    1999-01-01

    The Savannah River Site (SRS) is in the process of removing waste (sludge and salt cake) from million gallon waste tanks. The current practice for removing waste from the tanks is adding water, agitating the tanks with long shaft vertical centrifugal pumps, and pumping the sludge/salt solution from the tank to downstream treatment processes. This practice has left sludge heels (tilde 30,000 gallons) in the bottom of the tanks. SRS is evaluating shrouded axial impeller mixers for removing the sludge heels in the waste tanks. The authors conducted a test program to determine mixer requirements for suspending sludge heels using the shrouded axial impeller mixers. The tests were performed with zeolite in scaled tanks which have diameters of 1.5, 6.0, and 18.75 feet. The mixer speeds required to suspend zeolite particles were measured at each scale. The data were analyzed with various scaling methods to compare their ability to describe the suspension of insoluble solids with the mixers and to apply the data to a full-scale waste tank. The impact of changes in particle properties and operating parameters was also evaluated. The conclusions of the work are: Scaling of the suspension of fast settling zeolite particles was best described by the constant power per unit volume method. Increasing the zeolite particle concentration increased the required mixer power needed to suspend the particles. Decreasing the zeolite particle size from 0.7 mm 0.3 mm decreased the required mixer power needed to suspend the particles. Increasing the number of mixers in the tank decreased the required mixer power needed to suspend the particles. A velocity of 1.6 ft/sec two inches above the tank bottom is needed to suspend zeolite particles

  14. Nondestructive Testing Magnetic Particle RQA/M1-5330.11.

    Science.gov (United States)

    National Aeronautics and Space Administration, Huntsville, AL. George C. Marshall Space Flight Center.

    As one in the series of programmed instruction handbooks, prepared by the U. S. space program, home study material is presented in this volume concerning familiarization and orientation on magnetic particle properties. The subject is presented under the following headings: Magnetism, Producing a Magnetic Field, Magnetizing Currents, Materials and…

  15. DEVIATION OF STELLAR ORBITS FROM TEST PARTICLE TRAJECTORIES AROUND SGr A* DUE TO TIDES AND WINDS

    International Nuclear Information System (INIS)

    Psaltis, Dimitrios; Li, Gongjie; Loeb, Abraham

    2013-01-01

    Monitoring the orbits of stars around Sgr A* offers the possibility of detecting the precession of their orbital planes due to frame dragging, of measuring the spin and quadrupole moment of the black hole, and of testing the no-hair theorem. Here we investigate whether the deviations of stellar orbits from test-particle trajectories due to wind mass loss and tidal dissipation of the orbital energy compromise such measurements. We find that the effects of stellar winds are, in general, negligible. On the other hand, for the most eccentric orbits (e > 0.96) for which an optical interferometer, such as GRAVITY, will detect orbital plane precession due to frame dragging, the tidal dissipation of orbital energy occurs at timescales comparable to the timescale of precession due to the quadrupole moment of the black hole. As a result, this non-conservative effect is a potential source of systematic uncertainty in testing the no-hair theorem with stellar orbits

  16. DEVIATION OF STELLAR ORBITS FROM TEST PARTICLE TRAJECTORIES AROUND SGr A* DUE TO TIDES AND WINDS

    Energy Technology Data Exchange (ETDEWEB)

    Psaltis, Dimitrios [Astronomy Department, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721 (United States); Li, Gongjie; Loeb, Abraham, E-mail: dpsaltis@email.arizona.edu, E-mail: gli@cfa.harvard.edu, E-mail: aloeb@cfa.harvard.edu [Institute for Theory and Computation, Harvard-Smithsonian CfA, 60 Garden Street, Cambridge, MA (United States)

    2013-11-01

    Monitoring the orbits of stars around Sgr A* offers the possibility of detecting the precession of their orbital planes due to frame dragging, of measuring the spin and quadrupole moment of the black hole, and of testing the no-hair theorem. Here we investigate whether the deviations of stellar orbits from test-particle trajectories due to wind mass loss and tidal dissipation of the orbital energy compromise such measurements. We find that the effects of stellar winds are, in general, negligible. On the other hand, for the most eccentric orbits (e > 0.96) for which an optical interferometer, such as GRAVITY, will detect orbital plane precession due to frame dragging, the tidal dissipation of orbital energy occurs at timescales comparable to the timescale of precession due to the quadrupole moment of the black hole. As a result, this non-conservative effect is a potential source of systematic uncertainty in testing the no-hair theorem with stellar orbits.

  17. Effects of particle size and confining pressure on breakage factor of rockfill materials using medium triaxial test

    Directory of Open Access Journals (Sweden)

    Ashok Kumar Gupta

    2016-06-01

    Full Text Available Rockfill dams are mostly constructed using blasted rockfill materials obtained by blasting rocks or alluvial rockfill materials collected from the riverbeds. Behaviors of rockfill materials and their characterization significantly depend on breakage factor observed during triaxial loading. In this paper, two modeled rockfill materials are investigated by using medium triaxial cell. Drained triaxial tests are conducted on various sizes of modeled rockfill materials used in the two dams, and test data are analyzed accordingly. Breakage factor of rockfill material is studied and the effects of particle size and confining pressure on breakage factor are investigated using medium triaxial cell as many researchers have already conducted investigation using large triaxial cell.

  18. 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

  19. Synthesis, structural characterization and in vitro testing of dysprosium containing silica particles as potential MRI contrast enhancing agents

    Energy Technology Data Exchange (ETDEWEB)

    Chiriac, L.B.; Trandafir, D.L. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Turcu, R.V.F. [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Todea, M. [Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Simon, S., E-mail: simons@phys.ubbcluj.ro [Faculty of Physics & National Magnetic Resonance Center, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania); Interdisciplinary Research Institute on Bio-Nano-Sciences & Faculty of Physics, Babeş-Bolyai University, Cluj-Napoca, RO-400084 (Romania)

    2016-11-01

    Highlights: • Dysprosium containing silica microparticles obtained by freeze and spray drying. • Higher structural units interconnection achieved in freeze vs. spray dried samples. • Dy occurance on the outermost layer of the microparticles evidenced by XPS. • Enhanced MRI contrast observed for freeze dried samples with 5% mol Dy{sub 2}O{sub 3}. - Abstract: The work is focused on synthesis and structural characterization of novel dysprosium-doped silica particles which could be considered as MRI contrast agents. Sol-gel derived silica rich particles obtained via freeze-drying and spray-drying processing methods were structurally characterized by XRD, {sup 29}Si MAS-NMR and XPS methods. The occurrence of dysprosium on the outermost layer of dysprosium containing silica particles was investigated by XPS analysis. The MRI contrast agent characteristics have been tested using RARE-T{sub 1} and RARE-T{sub 2} protocols. The contrast of MRI images delivered by the investigated samples was correlated with their local structure. Dysprosium disposal on microparticles with surface structure characterised by decreased connectivity of the silicate network units favours dark T{sub 2}-weighted MRI contrast properties.

  20. Automatic particle-size analysis of HTGR recycle fuel

    International Nuclear Information System (INIS)

    Mack, J.E.; Pechin, W.H.

    1977-09-01

    An automatic particle-size analyzer was designed, fabricated, tested, and put into operation measuring and counting HTGR recycle fuel particles. The particle-size analyzer can be used for particles in all stages of fabrication, from the loaded, uncarbonized weak acid resin up to fully-coated Biso or Triso particles. The device handles microspheres in the range of 300 to 1000 μm at rates up to 2000 per minute, measuring the diameter of each particle to determine the size distribution of the sample, and simultaneously determining the total number of particles. 10 figures

  1. Assessment of particle-tracking models for dispersed particle-laden flows implemented in OpenFOAM and ANSYS FLUENT

    Directory of Open Access Journals (Sweden)

    Franziska Greifzu

    2016-01-01

    Full Text Available In the present study two benchmark problems for turbulent dispersed particle-laden flow are investigated with computational fluid dynamics (CFD. How the CFD programs OpenFOAM and ANSYS FLUENT model these flows is tested and compared. The numerical results obtained with Lagrangian–Eulerian (LE point-particle (PP models for Reynolds-averaged Navier–Stokes (RANS simulations of the fluid flow in steady state and transient modes are compared with the experimental data available in the literature. The effect of the dispersion model on the particle motion is investigated in particular, as well as the order of coupling between the continuous carrier phase and the dispersed phase. First, a backward-facing step (BFS case is validated. As a second case, the confined bluff body (CBB is used. The simulated fluid flows correspond well with the experimental data for both test cases. The results for the dispersed solid phase reveal a good accordance between the simulation results and the experiments. It seems that particle dispersion is slightly under-predicted when ANSYS FLUENT is used, whereas the applied solver in OpenFOAM overestimates the dispersion somewhat. Only minor differences between the coupling schemes are detected due to the low volume fractions and mass loadings that are investigated. In the BFS test case the importance of the spatial dimension of the numerical model is demonstrated. Even if it is reasonable to assume a two-dimensional fluid flow structure, it is crucial to simulate the turbulent particle-laden flow with a three-dimensional model since the turbulent dispersion of the particles is three-dimensional.

  2. Hot-melt extrusion for enhanced delivery of drug particles.

    Science.gov (United States)

    Miller, Dave A; McConville, Jason T; Yang, Wei; Williams, Robert O; McGinity, James W

    2007-02-01

    With the recent advent of nanotechnology for pharmaceutical applications, drug particle engineering is the focus of increasing interest as a viable approach for overcoming solubility limitations of poorly water-soluble drugs. Although these particle engineering techniques have been proven successful for enhancing the dissolution properties of many poorly water-soluble drugs, there are limitations associated with them such as particle aggregation, morphological instability, and poor wettability. The aim of this study was to demonstrate a processing technique in which hot-melt extrusion (HME) is utilized to overcome these limitations. Micronized particles of amorphous itraconazole (ITZ) stabilized with PVP or HPMC were produced and subsequently melt extruded with poloxamer 407 and PEO 200 M to deaggregate and disperse the particles into the hydrophilic polymer matrix. Differential scanning calorimetry, X-ray diffraction, and scanning electron microscopy were used to demonstrate that the HME process did not alter the properties of the micronized particles. Dissolution testing conducted at sink conditions revealed that the dissolution rate of the micronized particles was improved by HME due to particle deaggregation and enhanced wetting. Supersaturation dissolution testing demonstrated that the ITZ-HPMC micronized particle extrudates provided superior supersaturation of ITZ compared to the ITZ-PVP micronized particle extrudates. Supersaturation dissolution testing incorporating a pH change (from pH 1.2 to 6.8 at 2 h) revealed that neither micronized particle extrudate formulation significantly reduced the rate of ITZ precipitation from supersaturated solution once pH was increased. Moreover, the two extrudate formulations performed very similarly when only considering dissolution testing from just before pH adjustment through the duration of testing at neutral pH. From oral dosing of rats, it was determined that the two extrudate formulations performed similarly in

  3. Development of β particle hemorrhoids applicator

    International Nuclear Information System (INIS)

    Cai Shanyu; Liu Yunsheng; Zhang Pinyuan; Teng Kezhi; Gu Zeliang; Li Zhi

    2012-01-01

    A brachytherapy instrument, called β particle hemorrhoid therapeutic instrument or β particle hemorrhoid applicator was developed. It is mainly composed of radiator, locator, lifter, shield sleeve and controller. It can be used to treat internal piles, external piles, combined piles, anal fissure, anal sinusitis, etc. Preliminary clinical tests indicate that the advantages of β particle intracavitary radiotherapy are safe, effective, convenient, painless and non-invasive for curing hemorrhoids comparing with other techniques. (authors)

  4. Interim design report: fuel particle crushing

    International Nuclear Information System (INIS)

    Baer, J.W.; Strand, J.B.; Cook, E.J.; Miller, C.M.

    1977-11-01

    The double-roll fuel particle crusher was developed to fracture the silicon carbide coatings of Fort St. Vrain (FSV) fertile and fissile and large high-temperature gas-cooled reactor (LHTGR) fissile fuel particles. The report details the design task for the fuel particle crusher, including historical test information on double-roll crushers for carbide-coated fuels and the design approach selected for the cold pilot plant crusher, and shows how the design addresses the equipment goals and operational objectives. Design calculations and considerations are included to support the selection of crusher drive and gearing, the materials chosen for crushing rolls and housing, and the bearing selection. The results of the initial testing for compliance with design objectives and operational capabilities are also presented. 8 figures, 4 tables

  5. Creep tests of AISI 316 stainless steel irradiated by alpha particles of 28 MeV

    International Nuclear Information System (INIS)

    Segura, E.; Lucki, G.

    1986-01-01

    He-embrittlement effect in AISI 316 SS type throught creep tests performed with annealed and cold worked thin specimens is analized. Measurements were carried out at 700 and 750 0 C, stress of 100 MPa in vacuum better than 10 -5 torr. The He-implantations were made with the cyclotron CV-28 IPEN-CNEN/SP. Using an alpha-particle beam of 28 MeV, with concentration of 26 appm. From the valves of rupture deformation, epsilon sub(R), and rupture time, t sub(R), it was verified that he had a great effect on the operational life and ductility of this material. (Author) [pt

  6. Ionization history of the universe as a test for superheavy dark matter particles

    International Nuclear Information System (INIS)

    Doroshkevich, A.G.; Naselsky, P.D.

    2002-01-01

    In this paper we discuss the possible distortions of the ionization history of the universe caused by an injection of nonthermal energy due to decays of hypothetical superheavy dark matter (SHDM) particles. These particles are usually considered as a possible source of ultrahigh energy cosmic rays in the framework of the top-down model. Estimates of the fraction of energy of decays converted to the UV range show that, for suitable parameters of the SHDM particles, significant distortions of the power spectra of the cosmic microwave background anisotropy appear. A comparison with the observed power spectrum allows us to restrict some properties of the SHDM particles. These decays can also increase by about 5-10 times the degree of ionization of hydrogen at redshifts z∼10-50, which essentially accelerates the formation of molecules of H 2 and the first stars during the 'dark ages'

  7. Mechanism of Corrosion of Activated Aluminum Particles by Hot Water

    International Nuclear Information System (INIS)

    Razavi-Tousi, S.S.; Szpunar, J.A.

    2014-01-01

    Mechanism of corrosion in aluminum particles by hot water treatment for hydrogen generation is evaluated. The aluminum powder was activated by ball milling for different durations, which modified size and microstructure of the particles. Open circuit potential test was carried out to elucidate different stages of the reaction. Tafel test was used to explain the effect of ball milling and growth of hydroxide layer on corrosion of the particles. Surface, cross section and thickness of the grown hydroxide on the aluminum particles were studied in a scanning electron microscope. The corrosion potential of the aluminum powders depends on microstructure of the aluminum particles, growth of the hydroxide layer and a change in pH because of cathodic reactions. The hydrogen production test showed that a deformed microstructure and smaller particle size accelerates the corrosion rate of aluminum by hot water, the effect of the deformed microstructure being more significant at the beginning of the reaction. Effect of growth of the hydroxide layer on corrosion mechanism is discussed

  8. Acoustic Emission Monitoring of Compression-after-Impact Test of Nano-Particles-Coated CFRP Damaged by Simulated Lightning Strikes

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Je Ha; Kwon, Oh Yang; Seo, Seong Wook [Inha University, Incheon (Korea, Republic of)

    2011-02-15

    Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10{approx}40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terns of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes

  9. Acoustic Emission Monitoring of Compression-after-Impact Test of Nano-Particles-Coated CFRP Damaged by Simulated Lightning Strikes

    International Nuclear Information System (INIS)

    Shin, Je Ha; Kwon, Oh Yang; Seo, Seong Wook

    2011-01-01

    Nanoparticles-coated and impact-damaged carbon-fiber reinforced plastics(CFRP) laminates were tested under compression-after-impact(CAI) mode and the propagation of damage due to compressive loading has been monitored by acoustic emission(AE). The impact damage was induced not by mechanical loading but by a simulated lightning strike. CFRP laminates were made of carbon prepregs prepared by coating of conductive nano-particles directly on the fibers and the coupons were subjected to simulated lightning strikes with a high voltage/current impulse of 10∼40 kA within a few microseconds. The effects of nano-particles coating and the degree of damage induced by the simulated lightning strikes on the AE activities were examined, and the relationship between the compressive residual strength and AE behavior has been evaluated in terms of AE event counts and the onset of AE activity with the compressive loading. The degree of impact damage was also measured in terns of damage area by using ultrasonic C-scan images. From the results assessed during the CAI tests of damaged CFRP showed that AE monitoring appeared to be very useful to differentiate the degree of damage hence the mechanical integrity of composite structures damaged by lightning strikes

  10. God particle and origin of mass

    International Nuclear Information System (INIS)

    He Hongjian; Kuang Yuping

    2014-01-01

    The new Higgs boson discovered at the CERN LHC could be the God particle expected from the standard model. This revolutionary discovery opens up a new era of exploring the origin of masses for all elementary particles in the universe. It becomes a turning point of the particle physics in 21 th century. This article presents the following: (1) Scientific importance of searching and testing the God particle(s); (2) The history of studying the origin of mass, and why Newton mechanics and Einstein relativity could not resolve the origin of mass; (3) The mysterious vacuum and the mechanism of spontaneous symmetry breaking; (4) How the God particle was invented and how the LHC might have discovered it; (5) The perspective of seeking the origin of mass and new physics laws. (authors)

  11. Laboratory evaluation of the particle size effect on the performance of an elastomeric half-mask respirator against ultrafine combustion particles.

    Science.gov (United States)

    He, Xinjian; Grinshpun, Sergey A; Reponen, Tiina; Yermakov, Michael; McKay, Roy; Haruta, Hiroki; Kimura, Kazushi

    2013-08-01

    This study quantified the particle size effect on the performance of elastomeric half-mask respirators, which are widely used by firefighters and first responders exposed to combustion aerosols. One type of elastomeric half-mask respirator equipped with two P-100 filters was donned on a breathing manikin while challenged with three combustion aerosols (originated by burning wood, paper, and plastic). Testing was conducted with respirators that were fully sealed, partially sealed (nose area only), or unsealed to the face of a breathing manikin to simulate different faceseal leakages. Three cyclic flows with mean inspiratory flow (MIF) rates of 30, 85, and 135 L/min were tested for each combination of sealing condition and combustion material. Additional testing was performed with plastic combustion particles at other cyclic and constant flows. Particle penetration was determined by measuring particle number concentrations inside and outside the respirator with size ranges from 20 to 200 nm. Breathing flow rate, particle size, and combustion material all had significant effects on the performance of the respirator. For the partially sealed and unsealed respirators, the penetration through the faceseal leakage reached maximum at particle sizes >100 nm when challenged with plastic aerosol, whereas no clear peaks were observed for wood and paper aerosols. The particles aerosolized by burning plastic penetrated more readily into the unsealed half-mask than those aerosolized by the combustion of wood and paper. The difference may be attributed to the fact that plastic combustion particles differ from wood and paper particles by physical characteristics such as charge, shape, and density. For the partially sealed respirator, the highest penetration values were obtained at MIF = 85 L/min. The unsealed respirator had approximately 10-fold greater penetration than the one partially sealed around the bridge of the nose, which indicates that the nose area was the primary leak

  12. Effect of nanosilica particles on polypropylene polymer modified asphalt mixture performance

    Directory of Open Access Journals (Sweden)

    Nura Bala

    2018-06-01

    Full Text Available The current study was conducted to investigate the effect of nanosilica particles on the performance characteristics of polymer modified asphalt binders. In this study, control 80/100 binder were modified with polypropylene polymer and nanosilica particles at concentration of 0%–4%. Both nanosilica particles and polypropylene polymer were added by weight of total bitumen content. The asphalt performance tests flexural four point beam fatigue test, indirect tensile strength, indirect tensile stiffness modulus and draindown tests are conducted to evaluate the effect of nanosilica particles. The results of the study shows that nanosilica particles improves the fatigue properties of polypropylene polymer modified binder. This indicates that nanosilica particles have significant effect on improving the performance properties of polymer modified binders. Also, the result reveals that thermoplastic polymer polypropylene with nanosilica particles when used as bitumen modifiers improve the performance and durability of asphalt mixtures. Keywords: Polypropylene, Fatigue cracking, Stiffness modulus, Modified asphalt, Draindown

  13. Particle Pusher for the Investigation of Wave-Particle Interactions in the Magnetic Centrifugal Mass Filter (MCMF)

    Science.gov (United States)

    Kulp-McDowall, Taylor; Ochs, Ian; Fisch, Nathaniel

    2016-10-01

    A particle pusher was constructed in MATLAB using a fourth order Runge-Kutta algorithm to investigate the wave-particle interactions within theoretical models of the MCMF. The model simplified to a radial electric field and a magnetic field focused in the z direction. Studies on an average velocity calculation were conducted in order to test the program's behavior in the large radius limit. The results verified that the particle pusher was behaving correctly. Waves were then simulated on the rotating particles with a periodic divergenceless perturbation in the Bz component of the magnetic field. Preliminary runs indicate an agreement of the particle's motion with analytical predictions-ie. cyclic contractions of the doubly rotating particle's gyroradius.The next stage of the project involves the implementation of particle collisions and turbulence within the particle pusher in order to increase its accuracy and applicability. This will allow for a further investigation of the alpha channeling electrode replacement thesis first proposed by Abraham Fetterman in 2011. Made possible by Grants from the Princeton Environmental Institute (PEI) and the Program for Plasma Science and Technology (PPST).

  14. Physical characterization of the fine particle emissions from commercial aircraft engines during the Aircraft Particle Emissions eXperiment (APEX) 1-3

    Science.gov (United States)

    Kinsey, John S.; Dong, Yuanji; Williams, D. Craig; Logan, Russell

    2010-06-01

    The fine particulate matter (PM) emissions from nine commercial aircraft engine models were determined by plume sampling during the three field campaigns of the Aircraft Particle Emissions Experiment (APEX). Ground-based measurements were made primarily at 30 m behind the engine for PM mass and number concentration, particle size distribution, and total volatile matter using both time-integrated and continuous sampling techniques. The experimental results showed a PM mass emission index (EI) ranging from 10 to 550 mg kg -1 fuel depending on engine type and test parameters as well as a characteristic U-shaped curve of the mass EI with increasing fuel flow for the turbofan engines tested. Also, the Teflon filter sampling indicated that ˜40-80% of the total PM mass on a test-average basis was comprised of volatile matter (sulfur and organics) for most engines sampled. The number EIs, on the other hand, varied from ˜10 15 to 10 17 particles kg -1 fuel with the turbofan engines exhibiting a logarithmic decay with increasing fuel flow. Finally, the particle size distributions of the emissions exhibited a single primary mode that were lognormally distributed with a minor accumulation mode also observed at higher powers for all engines tested. The geometric (number) mean particle diameter ranged from 9.4 to 37 nm and the geometric standard deviation ranged from 1.3 to 2.3 depending on engine type, fuel flow, and test conditions.

  15. Online neural trigger for optimizing data acquisition during particle beam calibration tests with calorimeters

    International Nuclear Information System (INIS)

    Silva, P.V.M. da; Seixas, J.M. de; Damazio, D.O.; Ferreira, B.C.

    2004-01-01

    For LHC, the hadronic calorimetry of the ATLAS detector is performed by Tilecal, a scintillating tile calorimeter. For calibration purposes, a fraction of the Tilecal modules is placed in particle beam lines. Despite beam high quality, experimental beam contamination is observed and this masks the actual performance of the calorimeter. For optimizing the calibration task, an online neural particle classifier was developed for Tilecal. Envisaging a neural trigger for incoming particles, a neural process runs integrated to the data acquisition task and performs online training for particle identification. The neural classification performance is evaluated by correlating the neural response to classical methodology, confirming an ability for outsider identification at levels as high as 99.3%

  16. Online neural trigger for optimizing data acquisition during particle beam calibration tests with calorimeters

    CERN Document Server

    Da Silva, P V M; De Seixas, J M; Ferreira, B C

    2004-01-01

    For LHC, the hadronic calorimetry of the ATLAS detector is performed by Tilecal, a scintillating tile calorimeter. For calibration purposes, a fraction of the Tilecal modules is placed in particle beam lines. Despite beam high quality, experimental beam contamination is observed and this masks the actual performance of the calorimeter. For optimizing the calibration task, an online neural particle classifier was developed for Tilecal. Envisaging a neural trigger for incoming particles, a neural process runs integrated to the data acquisition task and performs online training for particle identification. The neural classification performance is evaluated by correlating the neural response to classical methodology, confirming an ability for outsider identification at levels as high as 99.3%.

  17. Single particle irradiation effect of digital signal processor

    International Nuclear Information System (INIS)

    Fan Si'an; Chen Kenan

    2010-01-01

    The single particle irradiation effect of high energy neutron on digital signal processor TMS320P25 in dynamic working condition has been studied. The influence of the single particle on the device has been explored through the acquired waveform and working current of TMS320P25. Analysis results, test data and test methods have also been presented. (authors)

  18. The motion of color-charged particles as a means of testing the non-Abelian dark matter model

    OpenAIRE

    Dzhunushaliev, V.; Folomeev, V.; Protsenko, N.

    2018-01-01

    A possibility is discussed for experimental testing of the dark matter model supported by a classic non-Abelian SU(3) gauge (Yang-Mills) field. Our approach is based on the analysis of the motion of color-charged particles on the background of color electric and magnetic fields using the Wong equations. Estimating the magnitudes of the color fields near the edge of a galaxy, we employ them in obtaining the general analytic solutions to the Wong equations. Using the latter, we calculate the ma...

  19. Laws of motion for interacting Yang-Mills particles

    International Nuclear Information System (INIS)

    Fuchs, H.

    1988-01-01

    Our recent Lagrangian approach to the equations of motion for test particles with internal structure can be enlarged to the laws of motion for interacting particles, at least in principle. As an example we consider the interaction of point particles endowed with a pole-dipole structure of the non-abelian charge. (author)

  20. Particle diffusion in a spheromak

    International Nuclear Information System (INIS)

    Meyerhofer, D.D.; Levinton, F.M.; Yamada, M.

    1988-01-01

    The local carbon particle diffusion coefficient was measured in the Proto S-1/C spheromak using a test particle injection scheme. When the plasma was not in a force-free Taylor state, and when there were pressure gradients in the plasma, the particle diffusion was five times that predicted by Bohm and was consistent with collisional drift wave diffusion. The diffusion appears to be driven by correlations of the fluctuating electric field and density. During the decay phase of the discharge when the plasma was in the Taylor state, the diffusion coefficient of the carbon was classical. 23 refs., 4 figs

  1. Testing the Standard Model

    CERN Document Server

    Riles, K

    1998-01-01

    The Large Electron Project (LEP) accelerator near Geneva, more than any other instrument, has rigorously tested the predictions of the Standard Model of elementary particles. LEP measurements have probed the theory from many different directions and, so far, the Standard Model has prevailed. The rigour of these tests has allowed LEP physicists to determine unequivocally the number of fundamental 'generations' of elementary particles. These tests also allowed physicists to ascertain the mass of the top quark in advance of its discovery. Recent increases in the accelerator's energy allow new measurements to be undertaken, measurements that may uncover directly or indirectly the long-sought Higgs particle, believed to impart mass to all other particles.

  2. Deposition of fine and ultrafine particles on indoor surface materials

    DEFF Research Database (Denmark)

    Afshari, Alireza; Reinhold, Claus

    2008-01-01

    -scale test chamber. Experiments took place in a 32 m3 chamber with walls and ceiling made of glass. Prior to each experiment the chamber was flushed with outdoor air to reach an initial particle concentration typical of indoor air in buildings with natural ventilation. The decay of particle concentrations...... The aim of this study was the experimental determination of particle deposition for both different particle size fractions and different indoor surface materials. The selected surface materials were glass, gypsum board, carpet, and curtain. These materials were tested vertically in a full...... was monitored. Seven particle size fractions were studied. These comprised ultrafine and fine particles. Deposition was higher on carpet and curtain than on glass and gypsum board. Particles ranging from 0.3 to 0.5 µm had the lowest deposition. This fraction also has the highest penetration and its indoor...

  3. Surface crack detection by magnetic particle inspection

    International Nuclear Information System (INIS)

    Goebbels, K.

    1988-01-01

    For ferromagnetic materials magnetic particle inspection is without doubt the most sensitive method to detect surface cracks and the least sensitive method referring to disturbing boundary conditions. Up to now the technique is based on experiments, experience, on empirical facts and on a subjective evaluation. This contribution for the first time presents a concept which allows the objective, reproducible as well as reliable magnetic particle inspection: Modelling of testing based on Maxwell's equations by finite element calculation; objective setting of test-parameters and their surveillance, handling systems, illumination and sensors, image processing and fully automated evaluation. Economy and safety of magnetic particle inspection are strongly improved by this procedure. (orig./HP) [de

  4. Performance Evaluation of "Low-cost" Sensors for Measuring Gaseous and Particle Air Pollutants: Results from Two Years of Field and Laboratory Testing

    Science.gov (United States)

    Feenstra, B. J.; Polidori, A.; Tisopulos, L.; Papapostolou, V.; Zhang, H.; Pathmanabhan, J.

    2016-12-01

    In recent years great progress has been made in development of low-cost miniature air quality sensing technologies. Such low-cost sensors offer a prospect of providing a real-time spatially dense information on pollutants, however, the quality of the data produced by these sensors is so far untested. In an effort to inform the general public about the actual performance of commercially available low-cost air quality sensors, in June 2014 the South Coast Air Quality Management District (SCAQMD) has established the Air Quality Sensor Performance Evaluation Center (AQ-SPEC). This program performs a thorough characterization of low-cost sensors under ambient (in the field) and controlled (in the laboratory) conditions. During the field testing, air quality sensors are operated side-by-side with Federal Reference Methods and Federal Equivalent Methods (FRM and FEM, respectively), which are routinely used to measure the ambient concentration of gaseous or particle pollutants for regulatory purposes. Field testing is conducted at two of SCAQMD's existing air monitoring stations, one in Rubidoux and one near the I-710 freeway. Sensors that demonstrate an acceptable performance in the field are brought back to the lab where a "characterization chamber" is used to challenge these devices with known concentrations of different particle and gaseous pollutants under different temperature and relative humidity levels. Testing results for each sensor are then summarized in a technical report and, along with other relevant information, posted online on a dedicated website (www.aqmd.gov/aq-spec) to educate the public about the capabilities of commercially available sensors and their potential applications. During this presentation, the results from two years of field and laboratory testing will be presented. The major strengths and weaknesses of some of the most commonly available particle and gaseous sensors will be discussed.

  5. Energetic Particles Dynamics in Mercury's Magnetosphere

    Science.gov (United States)

    Walsh, Brian M.; Ryou, A.S.; Sibeck, D. G.; Alexeev, I. I.

    2013-01-01

    We investigate the drift paths of energetic particles in Mercury's magnetosphere by tracing their motion through a model magnetic field. Test particle simulations solving the full Lorentz force show a quasi-trapped energetic particle population that gradient and curvature drift around the planet via "Shabansky" orbits, passing though high latitudes in the compressed dayside by equatorial latitudes on the nightside. Due to their large gyroradii, energetic H+ and Na+ ions will typically collide with the planet or the magnetopause and will not be able to complete a full drift orbit. These simulations provide direct comparison for recent spacecraft measurements from MESSENGER. Mercury's offset dipole results in an asymmetric loss cone and therefore an asymmetry in particle precipitation with more particles precipitating in the southern hemisphere. Since the planet lacks an atmosphere, precipitating particles will collide directly with the surface of the planet. The incident charged particles can kick up neutrals from the surface and have implications for the formation of the exosphere and weathering of the surface

  6. Systematic vacuum study of the ITER model cryopump by test particle Monte Carlo simulation

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xueli; Haas, Horst; Day, Christian [Institute for Technical Physics, Karlsruhe Institute of Technology, P.O. Box 3640, 76021 Karlsruhe (Germany)

    2011-07-01

    The primary pumping systems on the ITER torus are based on eight tailor-made cryogenic pumps because not any standard commercial vacuum pump can meet the ITER working criteria. This kind of cryopump can provide high pumping speed, especially for light gases, by the cryosorption on activated charcoal at 4.5 K. In this paper we will present the systematic Monte Carlo simulation results of the model pump in a reduced scale by ProVac3D, a new Test Particle Monte Carlo simulation program developed by KIT. The simulation model has included the most important mechanical structures such as sixteen cryogenic panels working at 4.5 K, the 80 K radiation shield envelope with baffles, the pump housing, inlet valve and the TIMO (Test facility for the ITER Model Pump) test facility. Three typical gas species, i.e., deuterium, protium and helium are simulated. The pumping characteristics have been obtained. The result is in good agreement with the experiment data up to the gas throughput of 1000 sccm, which marks the limit for free molecular flow. This means that ProVac3D is a useful tool in the design of the prototype cryopump of ITER. Meanwhile, the capture factors at different critical positions are calculated. They can be used as the important input parameters for a follow-up Direct Simulation Monte Carlo (DSMC) simulation for higher gas throughput.

  7. Effect of particle stratification on debris-bed dryout

    International Nuclear Information System (INIS)

    Gabor, J.D.; Cassulo, J.C.; Pederson, D.R.

    1982-01-01

    Significant work has been performed on debris-bed dryout on beds of either uniformly sized particles or particles of a wide size range which are well mixed. This work has provided an understanding of the mechanisms of dryout and an empirical basis for containment analysis. However, the debris bed resulting from a HCDA would not consist of uniformly sized particles and for certain scenarios the bed could be stratified rather than well mixed. Tests have been conducted on the effect of particle size distribution on dryout and concluded that not only is the mean particle size an important parameter but also the standard deviation of the distribution and change in porosity. The D6 in-pile test at Sandia with a 114-mm deep stratified bed resulted in a reduced dryout heat flux compared to a uniformly mixed bed. Because of the many questions concerning the dryout behavior of stratified beds of wide size distribution out-of-pile experiments in which metal particles in water pools are inductively heated were initiated at Argonne

  8. Acceptance Test Data for Candidate AGR-5/6/7 TRISO Particle Batches BWXT Coater Batches 93165 93172 Defective IPyC Fraction and Pyrocarbon Anisotropy

    Energy Technology Data Exchange (ETDEWEB)

    Helmreich, Grant W. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Hunn, John D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Skitt, Darren J. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Dyer, John A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Schumacher, Austin T. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-03-01

    Coated particle fuel batches J52O-16-93165, 93166, 93168, 93169, 93170, and 93172 were produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR). Some of these batches may alternately be used as demonstration coated particle fuel for other experiments. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μmnominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93165A).

  9. Plasma transport in stochastic magnetic fields. III. Kinetics of test-particle diffusion

    International Nuclear Information System (INIS)

    Krommes, J.A.; Oberman, C.; Kleva, R.G.

    1982-07-01

    A discussion is given of test particle transport in the presence of specified stochastic magnetic fields, with particular emphasis on the collisional limit. Certain paradoxes and inconsistencies in the literature regarding the form of the scaling laws are resolved by carefully distinguishing a number of physically distinct correlation lengths, and thus by identifying several collisional subregimes. The common procedure of averaging the conventional fluid equations over the statistics of a random field is shown to fail in some important cases because of breakdown of the Chapman-Enskog ordering in the presence of a stochastic field component with short autocorrelation length. A modified perturbation theory is introduced which leads to a Kubo-like formula valid in all collisionality regimes. The direct-interaction approximation is shown to fail in the interesting limit in which the orbit exponentiation length L/sub K/ appears explicitly. A higher order renormalized kinetic theory in which L/sub K/ appears naturally is discussed and used to rederive more systematically the results of the heuristic scaling arguments

  10. Extending the Modelling Framework for Gas-Particle Systems

    DEFF Research Database (Denmark)

    Rosendahl, Lasse Aistrup

    , with very good results. Single particle combustion has been tested using a number of different particle combustion models applied to coal and straw particles. Comparing the results of these calculations to measurements on straw burnout, the results indicate that for straw, existing heterogeneous combustion...... models perform well, and may be used in high temperature ranges. Finally, the particle tracking and combustion model is applied to an existing coal and straw co- fuelled burner. The results indicate that again, the straw follows very different trajectories than the coal particles, and also that burnout...

  11. Particle manipulation techniques in AEgIS

    Energy Technology Data Exchange (ETDEWEB)

    Canali, C., E-mail: canali@ge.infn.it; Carraro, C.; Di Noto, L.; Krasnicky, D.; Lagomarsino, V.; Testera, G.; Zavatarelli, S. [Istituto Nazionale Fisica Nucleare Sez. Genova (Italy)

    2011-07-15

    The AEgIS experiment (http://aegis.web.cern.chhttp://aegis.web.cern.ch) will measure the gravitational acceleration g of antihydrogen. Once performed this could be the first direct test of the gravitational interaction between matter and antimatter. In the AEgIS experiment a beam of antihydrogen will travel horizontally along a path of about 1 m trough a moire deflectometer followed by a position sensitive detector. The g value will be obtained measuring the vertical displacement of the annihilation patterns. Before producing the beam, several tasks have to be performed mainly involving positron and electron plasma manipulation and particles cooling in Malmberg-Penning traps. The AEgIS experiment is currently under construction at CERN, meanwhile several tests involving particle manipulation and particle cooling are in progress. In this report some experimental results involving diocotron manipulation of plasma will be presented.

  12. Research in particle theory

    International Nuclear Information System (INIS)

    Mansouri, F.; Suranyi, P; Wijewardhana, L.C.R.

    1991-10-01

    In the test particle approximation, the scattering amplitude for two-particle scattering in (2+1)-dimensional Chern-Simons-Witten gravity and supergravity was computed and compared to the corresponding metric solutions. The formalism was then extended to the exact gauge theoretic treatment of the two-particle scattering problem and compared to 't Hooft's results from the metric approach. We have studied dynamical symmetry breaking in 2+1 dimensional field theories. We have analyzed strong Extended Technicolor (ETC) models where the ETC coupling is close to a critical value. There are effective scalar fields in each of the theories. We have worked our how such scalar particles can be produced and how they decay. The φ 4 field theory was investigated in the Schrodinger representation. The critical behavior was extracted in an arbitrary number of dimensions in second order of a systematic truncation approximation. The correlation exponent agrees with known values within a few percent

  13. A numerical test method of California bearing ratio on graded crushed rocks using particle flow modeling

    Directory of Open Access Journals (Sweden)

    Yingjun Jiang

    2015-04-01

    Full Text Available In order to better understand the mechanical properties of graded crushed rocks (GCRs and to optimize the relevant design, a numerical test method based on the particle flow modeling technique PFC2D is developed for the California bearing ratio (CBR test on GCRs. The effects of different testing conditions and micro-mechanical parameters used in the model on the CBR numerical results have been systematically studied. The reliability of the numerical technique is verified. The numerical results suggest that the influences of the loading rate and Poisson's ratio on the CBR numerical test results are not significant. As such, a loading rate of 1.0–3.0 mm/min, a piston diameter of 5 cm, a specimen height of 15 cm and a specimen diameter of 15 cm are adopted for the CBR numerical test. The numerical results reveal that the CBR values increase with the friction coefficient at the contact and shear modulus of the rocks, while the influence of Poisson's ratio on the CBR values is insignificant. The close agreement between the CBR numerical results and experimental results suggests that the numerical simulation of the CBR values is promising to help assess the mechanical properties of GCRs and to optimize the grading design. Besides, the numerical study can provide useful insights on the mesoscopic mechanism.

  14. Neuropathy Tests

    Science.gov (United States)

    ... LD) Lactoferrin Lactose Tolerance Tests LDL Cholesterol LDL Particle Testing (LDL-P) Lead Legionella Testing Leptin Levetiracetam Lipase ... tests, such as computed tomography (CT) scans or magnetic resonance imaging ... suspected, additional testing may be performed to evaluate heart rate, blood ...

  15. Measurement of heavy particle and isotope

    International Nuclear Information System (INIS)

    Matsuoka, Masaru; Kohno, Takeshi; Imai, Takashi; Munakata, Kazuoki

    1987-01-01

    The report describes some achievements made so far in developing heavy particle and isotope measuring equipment that is planned to be mounted on the No.6 technical test satelite of the National Space Development Agency, ETS VI. Some ideas are proposed for such heavy particle and isotope measuring equipment that uses Astromag. The structure of SSD is shown which is planned to be incorporated in the sensor for the equipment. The planned charged particle detector consists of position sensitive detectors, PIN diodes and Si(Li) plates. Tests are made for the basic characteristics of such a detector. The characteristics of a PSD are also investigated. The PSD has a resolution of about 1 mm for 14 MeV He. Tests of a 0.3 mm PIN diode and 1.2 mm Si(Li) is carried out with 234 MeV-nucl Fe beams to determine their pulse height distribution. The PIN diode and Si(Li) are found to have a resolution of 6.79 and 17.6 MeV for energy loss of 158 and 710 MeV, respectively. If developed, a stripe-type Si PIN diode will serve for analysis of isotopes. A conceptual diagram of such a stripe device is proposed. The mechanism of measurement by a heavy particle and isotope detecting system incorporating Astromag is also illustrated. (Nogami, K.)

  16. Agile deployment and code coverage testing metrics of the boot software on-board Solar Orbiter's Energetic Particle Detector

    Science.gov (United States)

    Parra, Pablo; da Silva, Antonio; Polo, Óscar R.; Sánchez, Sebastián

    2018-02-01

    In this day and age, successful embedded critical software needs agile and continuous development and testing procedures. This paper presents the overall testing and code coverage metrics obtained during the unit testing procedure carried out to verify the correctness of the boot software that will run in the Instrument Control Unit (ICU) of the Energetic Particle Detector (EPD) on-board Solar Orbiter. The ICU boot software is a critical part of the project so its verification should be addressed at an early development stage, so any test case missed in this process may affect the quality of the overall on-board software. According to the European Cooperation for Space Standardization ESA standards, testing this kind of critical software must cover 100% of the source code statement and decision paths. This leads to the complete testing of fault tolerance and recovery mechanisms that have to resolve every possible memory corruption or communication error brought about by the space environment. The introduced procedure enables fault injection from the beginning of the development process and enables to fulfill the exigent code coverage demands on the boot software.

  17. General classification of charged test particle circular orbits in Reissner-Nordstroem spacetime

    Energy Technology Data Exchange (ETDEWEB)

    Pugliese, D. [Silesian University in Opava, Institute of Physics, Faculty of Philosophy and Science, Opava (Czech Republic); Quevedo, H. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, ICRA, Rome (Italy); Icranet-Pescara, Pescara (Italy); Universidad Nacional Autonoma de Mexico, Instituto de Ciencias Nucleares, Mexico, DF (Mexico); Kazakh National University, Department of Theoretical and Nuclear Physics, Almaty (Kazakhstan); Ruffini, R. [Universita di Roma ' ' La Sapienza' ' , Dipartimento di Fisica, ICRA, Rome (Italy); Icranet-Pescara, Pescara (Italy)

    2017-04-15

    We investigate charged particles' circular motion in the gravitational field of a charged mass distribution described by the Reissner-Nordstroem spacetime. We introduce a set of independent parameters completely characterizing the different spatial regions in which circular motion is allowed. We provide a most complete classification of circular orbits for different sets of particle and source charge-to-mass ratios. We study both black holes and naked singularities and show that the behavior of charged particles depend drastically on the type of source. Our analysis shows in an alternative manner that the behavior of circular orbits can in principle be used to distinguish between black holes and naked singularities. From this analysis, special limiting values for the dimensionless charge of black hole and naked singularity emerge, namely, Q/M = 1/2, Q/M = √(13)/5 and Q/M = √(2/3) for the black hole case and Q/M = 1, Q/M = 5/(2√(6)), Q/M = 3√(6)/7, and finally Q/M = √(9/8) for the naked singularity case. Similarly and surprisingly, analogous limits emerge for the orbiting particles charge-to-mass ratio ε, for positive charges ε = 1, ε = 2 and ε = M/Q. These limits play an important role in the study of the coupled electromagnetic and gravitational interactions, and the investigation of the role of the charge in the gravitational collapse of compact objects. (orig.)

  18. Spectroscopy after the new particles

    International Nuclear Information System (INIS)

    Lipkin, H.J.

    1975-01-01

    Conventional spectroscopy is reexamined in a search for puzzles and paradoxes which have arisen in attempting to describe the properties of the known particles. These may offer clues to the missing elements necessary for the description of the new particles. The minimum number of elementary building blocks, charm and color, the colored quark model for saturation, spin splittings in the meson spectrum, three kinds of quarks, the Melosh transformation and the Jackson frame, beyond the single-quark transition--the Zweig rule mystery, new particles and old symmetries, the f--A2 interference, and tests of the Zweig rule by rho--ω and f--A2--f' interference are considered

  19. Particle displacement tracking for PIV

    Science.gov (United States)

    Wernet, Mark P.

    1990-01-01

    A new Particle Imaging Velocimetry (PIV) data acquisition and analysis system, which is an order of magnitude faster than any previously proposed system has been constructed and tested. The new Particle Displacement Tracing (PDT) system is an all electronic technique employing a video camera and a large memory buffer frame-grabber board. Using a simple encoding scheme, a time sequence of single exposure images are time coded into a single image and then processed to track particle displacements and determine velocity vectors. Application of the PDT technique to a counter-rotating vortex flow produced over 1100 velocity vectors in 110 seconds when processed on an 80386 PC.

  20. Relativistic motion of spinning particles in a gravitational field

    International Nuclear Information System (INIS)

    Chicone, C.; Mashhoon, B.; Punsly, B.

    2005-01-01

    The relative motion of a classical relativistic spinning test particle is studied with respect to a nearby free test particle in the gravitational field of a rotating source. The effects of the spin-curvature coupling force are elucidated and the implications of the results for the motion of rotating plasma clumps in astrophysical jets are discussed

  1. Redistribution of energetic particles by background turbulence

    International Nuclear Information System (INIS)

    Hauff, T.; Jenko, F.

    2007-01-01

    The quest to understand the turbulent transport of particles, momentum and energy in magnetized plasmas remains a key challenge in fusion research. A basic issue being .still relatively poorly understood is the turbulent ExB advection of charged test particles with large gyroradii. Especially the interaction of alpha particles or impurities with the background turbulence is of great interest. In order to understand the dependence of the particle diffusivity on the interaction mechanisms between FLR effects and the special structure of a certain type of turbulence, direct numerical simulations are done in artificially created two dimensional turbulent electrostatic fields, assuming a constant magnetic field. Finite gyroradius effects are introduced using the gyrokinetic approximation which means that the gyrating particle is simply replaced by a charged ring. Starting from an idealized isotropic potential with Gaussian autocorrelation function, numerous test particle simulations are done varying both the gyroradius and the Kubo number of the potential. It is found that for Kubo numbers larger than about unity, the particle diffusivity is almost independent of the gyroradius as long as the latter does not exceed the correlation length of the electrostatic potential, whereas for small Kubo numbers the diffusivity is monotonically reduced. The underlying physical mechanisms of this behavior are identified and an analytic approach is developed which favorably agrees with the simulation results. The investigations are extended by introducing anisotropic structures like streamers and zonal flows into the artificial potential, leading to quantitative modulations of the gyroradius dependence of the diffusion coefficient. Analytic models are used to explain these various effects. After having developed a general overview on the behavior in simplified artificial potentials, test particle simulations in realistic turbulence created by the gyrokinetic turbulence code GENE are

  2. Visualizing test on the pass-through and collision characteristics of coarse particles in a double blade pump

    Directory of Open Access Journals (Sweden)

    Minggao Tan

    2018-01-01

    Full Text Available As the key equipment in deep ocean mining, the slurry pump suffers from wear and blocking problems. In this paper, high-speed photography technique is applied to track the movement rule of single particle of the coarse particle solid–liquid two-phase flow in a double blade slurry pump. The influences of particle diameter and particle density on the pass-through and collision characteristics of particles are analyzed as well. The results show that the average of the passing pump time first decreases and then increases when the particle diameter increases. The average of the passing pump time decreases by 22.7%, when the particle density increases from 1.09 g/cm3 to 1.75 g/cm3. Besides, the particle density has great influence on the location where the particle hits the tongue. Most particles of 1.09 g/cm3 hit the tongue on the left side, while collision location of particles of 1.75 g/cm3 is mainly on the top and at the right side of the tongue. The research can provide a basis for the optimization design of slurry pump in deep ocean mining system.

  3. Influence of agitation intensity on flotation rate of apatite particles

    Directory of Open Access Journals (Sweden)

    Francisco Gregianin Testa

    Full Text Available Abstract The agitation intensity has a directly influence on flotation performance, lifting the particles and promoting the contact of bubbles and particles. In this paper, the energy input by the agitation on apatite flotation was investigated. The influence of pulp agitation in the flotation rate of particles with different sizes and two dosage levels was evaluated by batch testing. The flotation tests were conducted in an oscillating grid flotation cell (OGC, developed to promote a near isotropic turbulence environment. The cell is able to control the intensity of agitation and measure the energy transferred to the pulp phase. A sample of pure apatite was crushed (P80=310µm, characterized and floated with sodium oleate as collector. Four levels of energy dissipation, from 0.1 to 2 kWm-3, and two levels of collector dosage are used during the tests. The flotation kinetics by particle size were determined in function of the energy transferred. The results show a strong influence of the agitation intensity on the apatite flotation rate with both low and high dosage. For fine particles, when increasing the energy input, the flotation rate increase too, and this fact can be attributed to elevation of bubble-particle collisions. The kinetic result for the coarse particles demonstrated a reduction of the flotation rate whenever the energy input for this particle size was increased, whereby the turbulence caused by the agitation promotes the detachment of bubble-particle.

  4. Testing confectionary products

    International Nuclear Information System (INIS)

    Kumar, M.; Smith, I.H.

    1983-01-01

    Cream-filled cakes are tested by passing a #betta#-ray from a #betta#-particle source to a detector and checking the #betta#-particle count to indicate if the cakes have been correctly filled with cream. The presence of a cake to be tested is sensed by an optical detector and incorrectly filled cakes are removed by a plunger. (author)

  5. Two new proofs of the test particle superposition principle of plasma kinetic theory

    International Nuclear Information System (INIS)

    Krommes, J.A.

    1976-01-01

    The test particle superposition principle of plasma kinetic theory is discussed in relation to the recent theory of two-time fluctuations in plasma given by Williams and Oberman. Both a new deductive and a new inductive proof of the principle are presented; the deductive approach appears here for the first time in the literature. The fundamental observation is that two-time expectations of one-body operators are determined completely in terms of the (x,v) phase space density autocorrelation, which to lowest order in the discreteness parameter obeys the linearized Vlasov equation with singular initial condition. For the deductive proof, this equation is solved formally using time-ordered operators, and the solution is then re-arranged into the superposition principle. The inductive proof is simpler than Rostoker's although similar in some ways; it differs in that first-order equations for pair correlation functions need not be invoked. It is pointed out that the superposition principle is also applicable to the short-time theory of neutral fluids

  6. Two new proofs of the test particle superposition principle of plasma kinetic theory

    International Nuclear Information System (INIS)

    Krommes, J.A.

    1975-12-01

    The test particle superposition principle of plasma kinetic theory is discussed in relation to the recent theory of two-time fluctuations in plasma given by Williams and Oberman. Both a new deductive and a new inductive proof of the principle are presented. The fundamental observation is that two-time expectations of one-body operators are determined completely in terms of the (x,v) phase space density autocorrelation, which to lowest order in the discreteness parameter obeys the linearized Vlasov equation with singular initial condition. For the deductive proof, this equation is solved formally using time-ordered operators, and the solution then rearranged into the superposition principle. The inductive proof is simpler than Rostoker's, although similar in some ways; it differs in that first order equations for pair correlation functions need not be invoked. It is pointed out that the superposition principle is also applicable to the short-time theory of neutral fluids

  7. Flue gas conditioning for improved particle collection in electrostatic precipitators

    Energy Technology Data Exchange (ETDEWEB)

    Durham, M.D.

    1993-04-16

    Several tasks have been completed in a program to evaluate additives to improve fine particle collection in electrostatic precipitators. Screening tests and laboratory evaluations of additives are summarized in this report. Over 20 additives were evaluated; four were found to improve flyash precipitation rates. The Insitec particle analyzer was also evaluated; test results show that the analyzer will provide accurate sizing and counting information for particles in the size range of [le] 10 [mu]m dia.

  8. Classical testing particles and (4 + N)-dimensional theories of space-time

    International Nuclear Information System (INIS)

    Nieto-Garcia, J.A.

    1986-01-01

    The Lagrangian theory of a classical relativistic spinning test particle (top) developed by Hanson and Regge and by Hojman is briefly reviewed. Special attention is devoted to the constraints imposed on the dynamical variables associated with the system of this theory. The equations for a relativistic top are formulated in a way suitable for use in the study of geometrical properties of the 4 + N-dimensional Kaluza-Klein background. It is shown that the equations of motion of a top in five dimensions reduce to the Hanson-Regge generalization of the Bargmann-Michel-Telegdi equations of motion in four dimensions when suitable conditions on the spin tensor are imposed. The classical bosonic relativistic string theory is discussed and the connection of this theory with the top theory is examined. It is found that the relation between the string and the top leads naturally to the consideration of a 3-dimensional extended system (called terron) which sweeps out a 4-dimensional surface as it evolves in a space-time. By using a square root procedure based on ideas by Teitelboim a theory of a supersymmetric top is developed. The quantization of the new supersymmetric system is discussed. Conclusions and suggestions for further research are given

  9. Development of coated particle fuel technology

    International Nuclear Information System (INIS)

    Cho, Moonsung; Kim, B. G.; Kim, D. J.

    2011-06-01

    Ammonia contacting method for prehardenning the surfaces of ADU liquid droplets and the ageing/washing/drying method and equipment for spherical dried-ADU particles were improved and tested with laboratory sacle. After the improvement of fabrication process, the sphericity of UO 2 kernel obtained to 1.1, and the sintered density and O/U ratio of final UO 2 kernel were above 10.60g/cm 3 . 2.01 respectively. Defects of SiC coating layer could be minimized by optimization of gas flow rate. The fracture strength of SiC layer increased from 450 MPa to 530 MPa by controlling the coating defects. An effort was made to develop the fundamental technology for the fuel element compact for use in High Temperature Gas-cooled Reactor(HTGR) through an establishment of fabrication process, required materials and process equipment as well as performing experiments to identify the basic process conditions and optimize them. Thermal load simulation and verification experiments were carried out for an assesment of the design feasibility of the irradiation rod. Out-of-pile testing of irradiation device such as measurement of pressure drop and vibration, endurance test was performed and the validity of its design was confirmed. A fuel performance analysis code, COPA has been developed to calculate the fuel temperature, the failure fractions of coated fuel particles, the release of fission products. The COPA code can be used to evaluate the performance of the high temperature reactor fuel under the reactor operation, irradiation, heating conditions. KAERI participated in the round robin test of IAEA CRP-6 program to characterize the diameter, sphericity, coating thickness, density and anisotropy of coated particles provided by Korea, USA and South Africa. QC technology was established for TRISO-coated fuel particle. A method for accurate measurement of the optical anisotropy factor for PyC layers of coated particles was developed. Technology and inspection procedures for density

  10. Quantifying the motion of magnetic particles in excised tissue: Effect of particle properties and applied magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Kulkarni, Sandip, E-mail: sandip.d.kulkarni@gmail.com [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Ramaswamy, Bharath; Horton, Emily; Gangapuram, Sruthi [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Nacev, Alek [Weinberg Medical Physics, LLC (United States); Depireux, Didier [The Institute for Systems Research, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States); Shimoji, Mika [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States); Shapiro, Benjamin [Fischell Department of Bioengineering, University of Maryland at College Park, MD 20742 (United States); The Institute for Systems Research, University of Maryland at College Park, MD 20742 (United States); Otomagnetics, LLC (United States)

    2015-11-01

    This article presents a method to investigate how magnetic particle characteristics affect their motion inside tissues under the influence of an applied magnetic field. Particles are placed on top of freshly excised tissue samples, a calibrated magnetic field is applied by a magnet underneath each tissue sample, and we image and quantify particle penetration depth by quantitative metrics to assess how particle sizes, their surface coatings, and tissue resistance affect particle motion. Using this method, we tested available fluorescent particles from Chemicell of four sizes (100 nm, 300 nm, 500 nm, and 1 μm diameter) with four different coatings (starch, chitosan, lipid, and PEG/P) and quantified their motion through freshly excised rat liver, kidney, and brain tissues. In broad terms, we found that the applied magnetic field moved chitosan particles most effectively through all three tissue types (as compared to starch, lipid, and PEG/P coated particles). However, the relationship between particle properties and their resulting motion was found to be complex. Hence, it will likely require substantial further study to elucidate the nuances of transport mechanisms and to select and engineer optimal particle properties to enable the most effective transport through various tissue types under applied magnetic fields.

  11. Challenges associated with the behaviour of radioactive particles in the environment

    DEFF Research Database (Denmark)

    Salbu, Brit; Kashparov, Valery; Lind, Ole Christian

    2018-01-01

    sites. Thus, whenever refractory radionuclides are released to the environment following nuclear events, radioactive particles should be expected. Results from many years of research have shown that particle characteristics such as elemental composition depend on the source, while characteristics...... on advanced techniques, with emphasis on particle weathering processes as well as on heterogeneities in biological samples to evaluate potential uptake and retention of radioactive particles.......A series of different nuclear sources associated with the nuclear weapon and fuel cycles have contributed to the release of radioactive particles to the environment. Following nuclear weapon tests, safety tests, conventional destruction of weapons, reactor explosions and fires, a major fraction...

  12. (1→3)-β-d-Glucan and Galactomannan for Differentiating Chemical "Black Particles" and Fungal Particles Inside Peritoneal Dialysis Tubing.

    Science.gov (United States)

    Leelahavanichkul, Asada; Pongpirul, Krit; Thongbor, Nisa; Worasilchai, Navaporn; Petphuak, Kwanta; Thongsawang, Bussakorn; Towannang, Piyaporn; Lorvinitnun, Pichet; Sukhontasing, Kanya; Katavetin, Pisut; Praditpornsilpa, Kearkiat; Eiam-Ong, Somchai; Chindamporn, Ariya; Kanjanabuch, Talerngsak

    2016-01-01

    ♦ Aseptic, sheet-like foreign bodies observed inside Tenckhoff (TK) catheter lumens (referred to as "black particles") are, on gross morphology, hardly distinguishable from fungal colonization because these contaminants adhere tightly to the catheter. Detection of fungal cell wall components using (1→3)-β-d-glucan (BG) and galactomannan index (GMI) might be an alternative method for differentiating the particles. ♦ Foreign particles retrieved from TK catheters in 19 peritoneal dialysis patients were examined microscopically and cultured for fungi and bacteria. Simultaneously, a Fungitell test (Associates of Cape Cod, Falmouth, MA, USA) and a Platelia Aspergillus ELISA assay (Bio-Rad Laboratories, Marnes-La-Coquette, France) were used to test the spent dialysate for BG and GMI respectively. ♦ Of the 19 patients, 9 had aseptic black particles and 10 had fungal particles in their tubing. The fungal particles looked grainy, were tightly bound to the catheter, and appeared more "colorful" than the black particles, which looked sheet-like and could easily be removed by milking the tubing. Compared with effluent from patients having aseptic particles, effluent from patients with fungal particles had significantly higher levels of BG (501 ± 70 pg/mL vs. 46 ± 10 pg/mL) and GMI (10.98 ± 2.17 vs. 0.25 ± 0.05). Most of the fungi that formed colonies inside the catheter lumen were molds not usually found in clinical practice, but likely from water or soil, suggesting environmental contamination. Interestingly, in all 10 patients with fungal colonization, visualization of black particles preceded a peritonitis episode and TK catheter removal by approximately 1-3 weeks; in patients with aseptic particles, a 17-week onset to peritonitis was observed. ♦ In all patients with particle-coated peritoneal dialysis tubing, spent dialysate should be screened for BG and GMI. Manipulation of the TK catheter by squeezing, hard flushing, or even brushing to dislodge black

  13. Stochastic transport of particles across single barriers

    International Nuclear Information System (INIS)

    Kreuter, Christian; Siems, Ullrich; Henseler, Peter; Nielaba, Peter; Leiderer, Paul; Erbe, Artur

    2012-01-01

    Transport phenomena of interacting particles are of high interest for many applications in biology and mesoscopic systems. Here we present measurements on colloidal particles, which are confined in narrow channels on a substrate and interact with a barrier, which impedes the motion along the channel. The substrate of the particle is tilted in order for the particles to be driven towards the barrier and, if the energy gained by the tilt is large enough, surpass the barrier by thermal activation. We therefore study the influence of this barrier as well as the influence of particle interaction on the particle transport through such systems. All experiments are supported with Brownian dynamics simulations in order to complement the experiments with tests of a large range of parameter space which cannot be accessed in experiments.

  14. 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...

  15. The hygroscopicity of indoor aerosol particles

    International Nuclear Information System (INIS)

    Wei, L.

    1993-07-01

    A system to study the hygroscopic growth of particle was developed by combining a Tandem Differential Mobility Analyzer (TDMA) with a wetted wall reactor. This system is capable of mimicking the conditions in human respiratory tract, and measuring the particle size change due to the hygroscopic growth. The performance of the system was tested with three kinds of particles of known composition, NaCl, (NH 4 ) 2 SO 4 , and (NH 4 )HS0 4 particles. The hygroscopicity of a variety of common indoor aerosol particles was studied including combustion aerosols (cigarette smoking, cooking, incenses and candles) and consumer spray products such as glass cleaner, general purpose cleaner, hair spray, furniture polish spray, disinfectant, and insect killer. Experiments indicate that most of the indoor aerosols show some hygroscopic growth and only a few materials do not. The magnitude of hygroscopic growth ranges from 20% to 300% depending on the particle size and fraction of water soluble components

  16. Physical test of a particle simulation model in a sheared granular system.

    Science.gov (United States)

    Rycroft, Chris H; Orpe, Ashish V; Kudrolli, Arshad

    2009-09-01

    We report a detailed comparison of a slow gravity-driven sheared granular flow with a discrete-element simulation performed in the same geometry. In the experiments, grains flow inside a silo with a rectangular cross section and are sheared by a rough boundary on one side and smooth boundaries on the other sides. Individual grain position and motion are measured using a particle index-matching imaging technique where a fluorescent dye is added to the interstitial liquid which has the same refractive index as the glass beads. The simulations use a Cundall-Strack contact model between the grains using contact parameters that have been used in many other previous studies and ignore the hydrodynamic effects of the interstitial liquid. Computations are performed to understand the effect of particle coefficient of friction, elasticity, contact model, and polydispersity on mean flow properties. We then perform a detailed comparison of the particle fluctuation properties as measured by the displacement probability distribution function and the mean square displacement. All in all, our study suggests a high level of quantitative agreement between the simulations and experiments.

  17. Evaluation of salt particle collection device for preventing SCC on canister - Effect on particle collection rate by electric field

    International Nuclear Information System (INIS)

    Takeda, H.; Saegusa, T.

    2013-01-01

    Now, in Japan, while metal casks are used for spent nuclear fuel storage, a practical use of concrete casks is under review because of its cost effectiveness and procurement easiness. In reviewing the practical use, stress corrosion cracking (SCC) of a canister container in the concrete cask becomes an issue and is needed to be resolved soon. A natural ventilation system is generally adopted for the storage facilities, especially in Japan where facilities are built near coasts so that the cooling air includes sea salt particles. Therefore, the occurrence of SCC is concerned when the sea salt particles adhere to welded parts of the canisters. In this study, we proposed a salt particle collection device with low pressure loss which does not interfere with the air flow into the building or the concrete casks. The device is composed of a stack of 10 parallel stainless steel plates, the air is free to circulate in the space between them. Pressure loss tests in a laboratory and salt particle collection tests in the field have been performed. It has been clarified that the pressure loss of the device is one-thirtieth to one-twentieth of that of a commercial filter and 40% of the particles in the air could be collected and the device would not influence the heat removal performance. Moreover, we evaluated the effect of electric field on the particle collection under supposing the particle charge. In the case of electric field over 10 3 kV/m the particle collection rate could be improved dramatically

  18. In Vitro Polyvinylformaldehyde Particle Compatibility with Chemotherapeutic Drugs Used for Chemoembolization Therapy

    International Nuclear Information System (INIS)

    Vallee, Jean-Noel; Guillevin, Remy; Lo, Daouda; Adem, Carmen; Benois, Florence; Chiras, Jacques

    2003-01-01

    Purpose: Because the effects of pirarubicin and carboplatin on the physical structure of particles made from polyvinylformaldehyde are not well known, we describe an experiment to test the in vitro polyvinylformaldehyde particle compatibility with these drugs used for chemoembolization of bone metastases. Materials and Methods: Polyvinylformaldehydeparticles (Ultra-Drivalon) were mixed in vitro with either pirarubicinor carboplatin as experimental samples, and with distilled water as control samples, and left for 24 h at 37 o C. The particles used measured 150-250 μm and 600-1000 μm in diameter. Particle morphology, including appearance, overall shape, and surface characteristics were examined using a microscope equipped with a videocamera. Particle size was measured by granulometry. Qualitative and quantitative variables were analyzed using, respectively, the two-sided Fisher's exact test and the Wilcoxon signed-rank rank test for paired values, with a significance level of 0.05. Results: No broken particles or microscopic degradations in the appearance, overall shape, or surface characteristics of any particles were observed. The particle size distribution was not significantly different between the experimental samples containing pirarubicin or carboplatin and the control sample of particles with diameters in the same range. Conclusion: Particles made from polyvinylformaldehyde can be mixed with pirarubicin or carboplatin without any risk of damaging their physical properties

  19. Particle size distribution control of Pt particles used for particle gun

    Science.gov (United States)

    Ichiji, M.; Akiba, H.; Nagao, H.; Hirasawa, I.

    2017-07-01

    The purpose of this study is particle size distribution (PSD) control of submicron sized Pt particles used for particle gun. In this report, simple reaction crystallization is conducted by mixing H2PtCl6 and ascorbic acid. Without the additive, obtained Pt particles have broad PSD and reproducibility of experiment is low. With seeding, Pt particles have narrow PSD and reproducibility improved. Additionally, mean particle diameter of 100-700 nm is controlled by changing seeding amount. Obtained particles are successfully characterized as Pt by XRD results. Moreover, XRD spectra indicate that obtained particles are polycrystals. These experimental results suggest that seeding consumed nucleation, as most nuclei attached on the seed surface. This mechanism virtually restricted nucleation to have narrow PSD can be obtained.

  20. Development and testing of an ion probe for tightly-bunched particle beams

    Energy Technology Data Exchange (ETDEWEB)

    Ngo, M.; Pasour, J.

    1996-06-01

    Many high-energy physics experiments require a high-quality and well-diagnosed charged-particle beam (CPB). Precise knowledge of beam size, position, and charge distribution is often crucial to the success of the experiment. It is also important in many applications that the diagnostic used to determine the beam parameters be nonintercepting and nonperturbing. This requirement rules out many diagnostics, such as wire scanners, thin foils which produce Cerenkov or transition radiation, and even some rf cavity diagnostics. Particularly difficult to diagnose are tightly-focused (r{sub b} << 1 mm), short-duration (psec) beams, such as those in state-of-the-art or next-generation particle colliders. In this paper we describe an ion probe that is capable of penetrating the space-charge field of densely bunched CPBs without perturbation, thereby enabling the measurement of the microstructure of the bunch. This diagnostic probe uses a finely-focused stream of ions to interact with the CPB. Related techniques have been discussed in the literature. In fact, the present work evolved from an electron deflection diagnostic for CPBs that we previously described. A similar electron probe was tested even earlier at TRIUMF and in the Former Soviet Union. Electron probes have also been used to measure plasma sheaths and potentials and the neutralization of heavy ion beams. Also, Mendel has used an ion beam (22 keV He{sup +}) to probe rapidly varying fields in plasmas. The probe ions are injected across the beam tube and into the path of the high-energy CPB. The ions are deflected by the CPB, and the direction and magnitude of the deflection are directly related to the spatial and temporal charge distribution of the CPB. Easily-resolved deflections can be produced by microbunches having total charge on the order of a nCoul and pulse durations of a few psec. The deflected ions are monitored with a suitable detector, in this case a microchannel plate capable of detecting single ions.

  1. Numerical Study of Particle Interaction in Gas-Particle and Liquid-Particle Flows: Part I Analysis and Validation

    Directory of Open Access Journals (Sweden)

    K. Mohanarangam

    2009-09-01

    Full Text Available A detailed study into the turbulent behaviour of dilute particulate flow under the influence of two carrier phases namely gas and liquid has been carried out behind a sudden expansion geometry. The major endeavour of the study is to ascertain the response of the particles within the carrier (gas or liquid phase. The main aim prompting the current study is the density difference between the carrier and the dispersed phases. While the ratio is quite high in terms of the dispersed phase for the gas-particle flows, the ratio is far more less in terms of the liquid-particle flows. Numerical simulations were carried out for both these classes of flows using an Eulerian two-fluid model with RNG based k-emodel as the turbulent closure. An additional kinetic energy equation to better represent the combined fluid-particle behaviour is also employed in the current set of simulations. In the first part of this two part series, experimental results of Fessler and Eaton (1995 for Gas-Particle (GP flow and that of Founti and Klipfel (1998 for Liquid-Particle (LP flow have been compared and analysed. This forms the basis of the current study which aims to look at the particulate behaviour under the influence of two carrier phases. Further numerical simulations were carried out to test whether the current numerical formulation can used to simulate these varied type of flows and the same were validated against the experimental data of both GP as well LP flow. Qualitative results have been obtained for both these classes of flows with their respective experimental data both at the mean as well as at the turbulence level for carrier as well as the dispersed phases.

  2. Forces on stationary particles in near-bed turbulent flows

    Science.gov (United States)

    Schmeeckle, Mark W.; Nelson, Jonathan M.; Shreve, Ronald L.

    2007-06-01

    In natural flows, bed sediment particles are entrained and moved by the fluctuating forces, such as lift and drag, exerted by the overlying flow on the particles. To develop a better understanding of these forces and the relation of the forces to the local flow, the downstream and vertical components of force on near-bed fixed particles and of fluid velocity above or in front of them were measured synchronously at turbulence-resolving frequencies (200 or 500 Hz) in a laboratory flume. Measurements were made for a spherical test particle fixed at various heights above a smooth bed, above a smooth bed downstream of a downstream-facing step, and in a gravel bed of similarly sized particles as well as for a cubical test particle and 7 natural particles above a smooth bed. Horizontal force was well correlated with downstream velocity and not correlated with vertical velocity or vertical momentum flux. The standard drag formula worked well to predict the horizontal force, but the required value of the drag coefficient was significantly higher than generally used to model bed load motion. For the spheres, cubes, and natural particles, average drag coefficients were found to be 0.76, 1.36, and 0.91, respectively. For comparison, the drag coefficient for a sphere settling in still water at similar particle Reynolds numbers is only about 0.4. The variability of the horizontal force relative to its mean was strongly increased by the presence of the step and the gravel bed. Peak deviations were about 30% of the mean force for the sphere over the smooth bed, about twice the mean with the step, and 4 times it for the sphere protruding roughly half its diameter above the gravel bed. Vertical force correlated poorly with downstream velocity, vertical velocity, and vertical momentum flux whether measured over or ahead of the test particle. Typical formulas for shear-induced lift based on Bernoulli's principle poorly predict the vertical forces on near-bed particles. The

  3. Relativistic local quantum field theory for m=0 particles

    International Nuclear Information System (INIS)

    Morales Villasevil, A.

    1965-01-01

    A method is introduced ta deal with relativistic quantum field theory for particles with m=0. Two mappings I and J, giving rise respectively to particle and anti particle states, are defined between a test space and the physical Hilbert space. The intrinsic field operator is then defined as the minimal causal linear combinations of operators belonging to the annihilation-creation algebra associated to the germ and antigerm parts of the element. Local elements are introduced as improper test elements and local field operators are constructed in the same way as the intrinsic ones. Commutation rules are given. (Author) 17 refs

  4. Dryout heat flux experiments with deep heterogeneous particle bed

    International Nuclear Information System (INIS)

    Lindholm, I.; Holmstroem, S.; Miettinen, J.; Lestinen, V.; Hyvaerinen, J.; Pankakoski, P.; Sjoevall, H.

    2006-01-01

    A test facility has been constructed at Technical Research Centre of Finland (VTT) to simulate as accurately as possible the ex-vessel core particle bed in the conditions of Olkiluoto nuclear power plant. The STYX particle bed reproduces the anticipated depth of the bed and the size range of particles having irregular shape. The bed is immersed in water, creating top flooding conditions, and internally heated by an array of electrical resistance heating elements. Dryout tests have been successfully conducted at 0.1-0.7 MPa pressure for both uniformly mixed and stratified bed geometries. In all tests, including the stratified ones, the dry zone first formed near the bottom of the bed. The measured dryout heat fluxes increased with increasing pressure, from 232 kW/m 2 at near atmospheric pressure to 451 kW/m 2 at 0.7 MPa pressure. The data show some scatter even for the uniform bed. The tests with the stratified bed indicate a clear reduction of critical power due to the presence of a layer of small particles on top of the uniform bed. Comparison of data with various critical power (dryout heat flux) correlations for porous media shows that the most important parameter in the models is the effective particle diameter. Adiabatic debris bed flow resistance measurements were conducted to determine the most representative particle diameter. This diameter is close, but not equal, to the particle number-weighted average diameter of the bed material. With it, uniform bed data can be calculated to within an accuracy of 3-28% using Lipinski's 0-D model. In the stratified bed experiments, it appears that the top layer was partially fluidized, hence the measured critical power was significantly higher than calculated. Future experiments are being planned with denser top layer material to eliminate non-prototypic fluidization

  5. Flexible high-loading particle-reinforced polyurethane magnetic nanocomposite fabrication through particle-surface-initiated polymerization

    International Nuclear Information System (INIS)

    Guo Zhanhu; Park, Sung; Wei Suying; Pereira, Tony; Moldovan, Monica; Karki, Amar B; Young, David P; Hahn, H Thomas

    2007-01-01

    Flexible high-loading nanoparticle-reinforced polyurethane magnetic nanocomposites fabricated by the surface-initiated polymerization (SIP) method are reported. Extensive field emission scanning electron microscopic (SEM) and atomic force microscopic (AFM) observations revealed a uniform particle distribution within the polymer matrix. X-ray photoelectron spectrometry (XPS) and differential thermal analysis (DTA) revealed a strong chemical bonding between the nanoparticles and the polymer matrix. The elongation of the SIP nanocomposite under tensile test was about four times greater than that of the composite fabricated by a conventional direct mixing fabrication method. The nanocomposite shows particle-loading-dependent magnetic properties, with an increase of coercive force after the magnetic nanoparticles were embedded into the polymer matrix, arising from the increased interparticle distance and the introduced polymer-particle interactions

  6. Particle swarm genetic algorithm and its application

    International Nuclear Information System (INIS)

    Liu Chengxiang; Yan Changxiang; Wang Jianjun; Liu Zhenhai

    2012-01-01

    To solve the problems of slow convergence speed and tendency to fall into the local optimum of the standard particle swarm optimization while dealing with nonlinear constraint optimization problem, a particle swarm genetic algorithm is designed. The proposed algorithm adopts feasibility principle handles constraint conditions and avoids the difficulty of penalty function method in selecting punishment factor, generates initial feasible group randomly, which accelerates particle swarm convergence speed, and introduces genetic algorithm crossover and mutation strategy to avoid particle swarm falls into the local optimum Through the optimization calculation of the typical test functions, the results show that particle swarm genetic algorithm has better optimized performance. The algorithm is applied in nuclear power plant optimization, and the optimization results are significantly. (authors)

  7. Study of correlations of positive and negative charged particles

    International Nuclear Information System (INIS)

    Takahashi, Y.; Chan, C.H.; Dong, B.L.; Duthie, J.G.; Gregory, J.C.; Hayashi, T.; Yokomi, H.; Christl, M.J.; Derrickson, J.H.; Eby, P.B.; Fountain, W.F.; Parnell, T.A.; Roberts, F.E.; Nagamiya, S.; Dake, S.; Tominaga, T.; Fuki, M.; Iyono, A.; Ogata, T.; Miyamura, O.

    1991-01-01

    Particle correlations of the central collision events of 32 S + Pb at 200 GeV/AMU have been studied by utilizing a Magnetic-Interferomagnetic-Emulsion-Chamber (MAGIC) detector. Particle angles, momentum, and charge-signs are measured for all produced charged tracks for each event. Two-particle correlation functions, C 2 = dN (vertical strokep 1 - p 2 vertical stroke = q)/dp 1 dp 2 , for (++), (--) and (+-) particles are examined. A source radius around 4 - 6 fm is observed for overall identical particle correlations, while unexpected short-range correlations of unlike-sign pairs are observed in the high rapidity region. An analysis of unlike-sign pairs in terms of resonance decays indicated that a large amount (40% relative to pions) of η or ω mesons (decaying into 3 π), or of scalar iso-scalar σ mesons (decaying into 2 π) would be required to explain some of the data. Multi-particle charge-sign clusters are recognized; however, their 'run-test' and 'conjugate-test' show small deviations from statistical fluctuations. (orig.)

  8. Improved graphite matrix for coated-particle fuel

    International Nuclear Information System (INIS)

    Schell, D.H.; Davidson, K.V.

    1978-10-01

    An experimental process was developed to incorporate coated fuel particles in an extruded graphite matrix. This structure, containing 41 vol% particles, had a high matrix density, >1.6 g/cm 3 , and a matrix conductivity three to four times that of a pitch-injected fuel rod at 1775 K. Experiments were conducted to determine the uniformity of particle loadings in extrusions. Irradiation specimens were supplied for five tests in the High-Fluence Isotope Reactor at the Oak Ridge National Laboratory

  9. Plasma particle accelerators

    International Nuclear Information System (INIS)

    Dawson, J.M.

    1988-01-01

    The Superconducting Supercollider (SSC) will require an 87-kilometer accelerator ring to boost particles to 40 TeV. The SSC's size is due in part to the fact that its operating principle is the same one that has dominated accelerator design for 50 years: it guides particles by means of magnetic fields and propels them by strong electric fields. If one were to build an equally powerful but smaller accelerator, one would need to increase the strength of the guiding and propelling fields. Actually, however, conventional technology may not be able to provide significant increases in field strength. There are two reasons. First, the forces from magnetic fields are becoming greater than the structural forces that hold a magnetic material together; the magnets that produce these fields would themselves be torn apart. Second, the energy from electric fields is reaching the energies that bind electrons to atoms; it would tear electrons from nuclei in the accelerator's support structures. It is the electric field problem that plasma accelerators can overcome. Plasma particle accelerators are based on the principle that particles can be accelerated by the electric fields generated within a plasma. Because the plasma has already been ionized, plasma particle accelerators are not susceptible to electron dissociation. They can in theory sustain accelerating fields thousands of times stronger that conventional technologies. So far two methods for creating plasma waves for accelerators have been proposed and tested: the wakefield and the beat wave. Although promising electric fields have been produced, more research is necessary to determine whether plasma particle accelerators can compete with the existing accelerators. 7 figs

  10. Radioactive particles in the environment: sources, particle characterization and analytical techniques

    International Nuclear Information System (INIS)

    2011-08-01

    Over the years, radioactive particles have been released to the environment from nuclear weapons testing and nuclear fuel cycle operations. However, measurements of environmental radioactivity and any associated assessments are often based on the average bulk mass or surface concentration, assuming that radionuclides are homogeneously distributed as simple ionic species. It has generally not been recognised that radioactive particles present in the environment often contain a significant fraction of the bulk sample activity, leading to sample heterogeneity problems and false and/or erratic measurement data. Moreover, the inherent differences in the transport and bioavailability of particle bound radionuclides compared with those existing as molecules or ions have largely been ignored in dose assessments. To date, most studies regarding radionuclide behaviour in the soil-plant system have dealt with soluble forms of radionuclides. When radionuclides are deposited in a less mobile form, or in case of a superposition of different physico-chemical forms, the behaviour of radionuclides becomes much more complicated and extra efforts are required to provide information about environmental status and behaviour of radioactive particles. There are currently no documents or international guides covering this aspect of environmental impact assessments. To fill this gap, between 2001 and 2008 the IAEA performed a Coordinated Research Programme (CRP- G4.10.03) on the 'Radiochemical, Chemical and Physical Characterization of Radioactive Particles in the Environment' with the objective of development, adoption and application of standardized analytical techniques for the comprehensive study of radioactive particles. The CRP was in line with the IAEA project intended to assist the Member States in building capacity for improving environmental assessments and for management of sites contaminated with radioactive particles. This IAEA-TECDOC presents the findings and achievements of

  11. Noiseless Vlasov–Poisson simulations with linearly transformed particles

    Energy Technology Data Exchange (ETDEWEB)

    Campos Pinto, Martin, E-mail: campos@ann.jussieu.fr [Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); CNRS, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); UPMC Univ. Paris 06, UMR 7598, Laboratoire Jacques-Louis Lions, F-75005, Paris (France); Sonnendrücker, Eric, E-mail: sonnen@math.unistra.fr [IRMA, UMR 7501, Université de Strasbourg and CNRS, 7 rue René Descartes, F-67084 Strasbourg Cedex (France); Project-team CALVI, INRIA Nancy Grand Est, 7 rue René Descartes, F-67084 Strasbourg Cedex (France); Friedman, Alex, E-mail: af@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Grote, David P., E-mail: grote1@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Lund, Steve M., E-mail: smlund@llnl.gov [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States); Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2014-10-15

    We introduce a deterministic discrete-particle simulation approach, the Linearly-Transformed Particle-In-Cell (LTPIC) method, that employs linear deformations of the particles to reduce the noise traditionally associated with particle schemes. Formally, transforming the particles is justified by local first order expansions of the characteristic flow in phase space. In practice the method amounts of using deformation matrices within the particle shape functions; these matrices are updated via local evaluations of the forward numerical flow. Because it is necessary to periodically remap the particles on a regular grid to avoid excessively deforming their shapes, the method can be seen as a development of Denavit's Forward Semi-Lagrangian (FSL) scheme (Denavit, 1972 [8]). However, it has recently been established (Campos Pinto, 2012 [20]) that the underlying Linearly-Transformed Particle scheme converges for abstract transport problems, with no need to remap the particles; deforming the particles can thus be seen as a way to significantly lower the remapping frequency needed in the FSL schemes, and hence the associated numerical diffusion. To couple the method with electrostatic field solvers, two specific charge deposition schemes are examined, and their performance compared with that of the standard deposition method. Finally, numerical 1d1v simulations involving benchmark test cases and halo formation in an initially mismatched thermal sheet beam demonstrate some advantages of our LTPIC scheme over the classical PIC and FSL methods. Benchmarked test cases also indicate that, for numerical choices involving similar computational effort, the LTPIC method is capable of accuracy comparable to or exceeding that of state-of-the-art, high-resolution Vlasov schemes.

  12. Particle Settling in Low Energy Turbulence

    Science.gov (United States)

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

    2014-11-01

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

  13. Deposition of Aerosol Particles in Electrically Charged Membrane Filters

    Energy Technology Data Exchange (ETDEWEB)

    Stroem, L

    1972-05-15

    A theory for the influence of electric charge on particle deposition on the surface of charged filters has been developed. It has been tested experimentally on ordinary membrane filters and Nuclepore filters of 8 mum pore size, with a bipolar monodisperse test aerosol of 1 mum particle diameter, and at a filter charge up to 20 muC/m2. Agreement with theory was obtained for the Coulomb force between filter and particle for both kinds of filters. The image force between charged filter and neutral particles did not result in the predicted deposition in the ordinary membrane filter, probably due to lacking correspondence between the filter model employed for the theory, and the real filter. For the Nuclepore filter a satisfactory agreement with theory was obtained, also at image interaction

  14. Influence of Particle Size in Talc Suppression by a Galactomannan Depressant

    Directory of Open Access Journals (Sweden)

    Zhixiang Chen

    2018-03-01

    Full Text Available Flotation behavior of different sizes of particles may follow different trends. The influence of particle size in talc suppression by a depressant galactomannan was studied in this research. The flotation response and mechanism were examined by flotation tests, modified flotation rate constant and entrainment recovery calculation, laser particle size experiments, adsorption tests, and advancing contact angle measurement as well as scanning electron microscopy (SEM and energy dispersive X-ray spectrometry (EDS. The maximum recovery increased with particle size increases in the absence of galactomannan FPY (Fenugreek polysaccharide. The obviously suppressed effect was observed for the size fraction of −74 + 38 μm after reacting with FPY, but low efficiency was received for −38 μm and −10 μm, respectively. Laser particle size analysis indicated that the FPY has a certain function for the flocculation of fine particles. It is beneficial for reducing recovery by entrainment. EDS and advancing contact angle test results showed that the difference in contact angles probably is a result of genuine differences in the quantity of O and Mg bearing surface species, while the contact angle varied with particle size fraction in the absence of FPY. Adsorption and SEM test results demonstrated that in the case of −74 + 38 μm, the depressant adsorption density on the mineral surface is higher than the other two size fractions. On the whole, FPY probably is not enough of a depressant for talc suppression.

  15. PENTACLE: Parallelized particle-particle particle-tree code for planet formation

    Science.gov (United States)

    Iwasawa, Masaki; Oshino, Shoichi; Fujii, Michiko S.; Hori, Yasunori

    2017-10-01

    We have newly developed a parallelized particle-particle particle-tree code for planet formation, PENTACLE, which is a parallelized hybrid N-body integrator executed on a CPU-based (super)computer. PENTACLE uses a fourth-order Hermite algorithm to calculate gravitational interactions between particles within a cut-off radius and a Barnes-Hut tree method for gravity from particles beyond. It also implements an open-source library designed for full automatic parallelization of particle simulations, FDPS (Framework for Developing Particle Simulator), to parallelize a Barnes-Hut tree algorithm for a memory-distributed supercomputer. These allow us to handle 1-10 million particles in a high-resolution N-body simulation on CPU clusters for collisional dynamics, including physical collisions in a planetesimal disc. In this paper, we show the performance and the accuracy of PENTACLE in terms of \\tilde{R}_cut and a time-step Δt. It turns out that the accuracy of a hybrid N-body simulation is controlled through Δ t / \\tilde{R}_cut and Δ t / \\tilde{R}_cut ˜ 0.1 is necessary to simulate accurately the accretion process of a planet for ≥106 yr. For all those interested in large-scale particle simulations, PENTACLE, customized for planet formation, will be freely available from https://github.com/PENTACLE-Team/PENTACLE under the MIT licence.

  16. Thermomechanical interactions of particle bed-structural wall in a layered configuration. Pt. 1. Effect of particle bed thermal expansions

    International Nuclear Information System (INIS)

    Tehranian, F.

    1995-01-01

    Materials in the form of particle beds have been considered for shielding and tritium breeding as well as neutron multiplication in many of the conceptual reactor design studies. As the level of effort of the fusion blanket community in the area of out-of-pile and in-pile (ITER) testing of integrated test modules increases, so does the need for modelling capability for predicting the thermomechanical responses of the test modules under reactor environment.In this study, the thermomechanical responses of a particle bed-structural wall system in a layered configuration, subjected to bed temperature rise and/or external coolant pressure, were considered. Equations were derived which represent the dependence of the particle-to-particle and particle-to-wall contact forces and areas on the structural wall deformations and in turn on the thermomechanical loads. Using the derived equations, parametric analyses were performed to study the variations in the thermomechanical response quantities of a beryllium particle bed-stainless steel structural wall when subjected to thermomechanical loads. The results are presented in two parts. In Part I, presented in this paper, the derivation of the analytical equations and the effects of bed temperature rise are discussed. In Part II of this study, also presented in this symposium, the effects of external coolant pressure as well as the combined effects of bed temperature rise and coolant pressure on the thermomechanical responses are given.It is shown that, depending on the stiffness of the structural walls, uniform bed temperature rises in the range 100-400 C result in non-uniform effective thermal properties through the prticle bed and could increase the bed effective thermal conductivity by a factor of 2-5 and the bed-wall interface thermal conductance by even a larger factor. (orig.)

  17. Discrete particle noise in particle-in-cell simulations of plasma microturbulence

    International Nuclear Information System (INIS)

    Nevins, W.M.; Hammett, G.W.; Dimits, A.M.; Dorland, W.; Shumaker, D.E.

    2005-01-01

    Recent gyrokinetic simulations of electron temperature gradient (ETG) turbulence with the global particle-in-cell (PIC) code GTC [Z. Lin et al., Proceedings of the 20th Fusion Energy Conference, Vilamoura, Portugal, 2004 (IAEA, Vienna, 2005)] yielded different results from earlier flux-tube continuum code simulations [F. Jenko and W. Dorland, Phys. Rev. Lett. 89, 225001 (2002)] despite similar plasma parameters. Differences between the simulation results were attributed to insufficient phase-space resolution and novel physics associated with global simulation models. The results of the global PIC code are reproduced here using the flux-tube PIC code PG3EQ [A. M. Dimits et al., Phys. Rev. Lett. 77, 71 (1996)], thereby eliminating global effects as the cause of the discrepancy. The late-time decay of the ETG turbulence and the steady-state heat transport observed in these PIC simulations are shown to result from discrete particle noise. Discrete particle noise is a numerical artifact, so both these PG3EQ simulations and, by inference, the GTC simulations that they reproduced have little to say about steady-state ETG turbulence and the associated anomalous heat transport. In the course of this work several diagnostics are developed to retrospectively test whether a particular PIC simulation is dominated by discrete particle noise

  18. Particle stabilization of plastic flow in nanostructured Al-1 %Si Alloy

    DEFF Research Database (Denmark)

    Huang, Tianlin; Li, Chao; Wu, Guilin

    2014-01-01

    A nanostructured Al-1 %Si alloy containing a dispersion of Si particles in ultrapure aluminum (99.9996 %) was produced by heavy cold rolling to study the effect of second-phase particles on the occurrence of plastic instability during tensile testing of a nanostructured metal. Tensile tests were...

  19. Do plastic particles affect microalgal photosynthesis and growth?

    Science.gov (United States)

    Sjollema, Sascha B; Redondo-Hasselerharm, Paula; Leslie, Heather A; Kraak, Michiel H S; Vethaak, A Dick

    2016-01-01

    The unbridled increase in plastic pollution of the world's oceans raises concerns about potential effects these materials may have on microalgae, which are primary producers at the basis of the food chain and a major global source of oxygen. Our current understanding about the potential modes and mechanisms of toxic action that plastic particles exert on microalgae is extremely limited. How effects might vary with particle size and the physico-chemical properties of the specific plastic material in question are equally unelucidated, but may hold clues to how toxicity, if observed, is exerted. In this study we selected polystyrene particles, both negatively charged and uncharged, and three different sizes (0.05, 0.5 and 6μm) for testing the effects of size and material properties. Microalgae were exposed to different polystyrene particle sizes and surface charges for 72h. Effects on microalgal photosynthesis and growth were determined by pulse amplitude modulation fluorometry and flow cytometry, respectively. None of the treatments tested in these experiments had an effect on microalgal photosynthesis. Microalgal growth was negatively affected (up to 45%) by uncharged polystyrene particles, but only at high concentrations (250mg/L). Additionally, these adverse effects were demonstrated to increase with decreasing particle size. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Fly ash particles spheroidization using low temperature plasma energy

    OpenAIRE

    Shekhovtsov, V. V.; Volokitin, O. G.; Vitske, Rudolf Evaldovich; Kondratyuk, Alexey Alekseevich

    2016-01-01

    The paper presents the investigations on producing spherical particles 65-110 [mu]m in size using the energy of low temperature plasma (LTP). These particles are based on flow ash produced by the thermal power plant in Seversk, Tomsk region, Russia. The obtained spherical particles have no defects and are characterized by a smooth exterior surface. The test bench is designed to produce these particles. With due regard for plasma temperature field distribution, it is shown that the transition ...

  1. Validation Testing of a Peridynamic Impact Damage Model Using NASA's Micro-Particle Gun

    Science.gov (United States)

    Baber, Forrest E.; Zelinski, Brian J.; Guven, Ibrahim; Gray, Perry

    2017-01-01

    Through a collaborative effort between the Virginia Commonwealth University and Raytheon, a peridynamic model for sand impact damage has been developed1-3. Model development has focused on simulating impacts of sand particles on ZnS traveling at velocities consistent with aircraft take-off and landing speeds. The model reproduces common features of impact damage including pit and radial cracks, and, under some conditions, lateral cracks. This study focuses on a preliminary validation exercise in which simulation results from the peridynamic model are compared to a limited experimental data set generated by NASA's recently developed micro-particle gun (MPG). The MPG facility measures the dimensions and incoming and rebound velocities of the impact particles. It also links each particle to a specific impact site and its associated damage. In this validation exercise parameters of the peridynamic model are adjusted to fit the experimentally observed pit diameter, average length of radial cracks and rebound velocities for 4 impacts of 300 µm glass beads on ZnS. Results indicate that a reasonable fit of these impact characteristics can be obtained by suitable adjustment of the peridynamic input parameters, demonstrating that the MPG can be used effectively as a validation tool for impact modeling and that the peridynamic sand impact model described herein possesses not only a qualitative but also a quantitative ability to simulate sand impact events.

  2. Preparation and biocompatibility of poly (methyl methacrylate reinforced with bioactive particles

    Directory of Open Access Journals (Sweden)

    Pereira Marivalda de Magalhães

    2003-01-01

    Full Text Available Calcium phosphates and bioactive glasses have been used in many biomedical applications for more than 30 years due basically to their bioactive behavior. However, ceramics are too brittle for applications that require high levels of toughness and easy processability. In this work, a biphasic calcium phosphate (BCP and a bioactive glass composition (BG were combined with polymers to produce composites with tailorable properties and processability. The BCP particles were synthesized by a precipitation technique. The BG particles were produced by sol-gel processing. The BCP particles were treated with a silane agent to improve the compatibility between particles and the polymer matrix. Dense samples were produced by hot pressing (200 °C a mixture of 30 wt.% of particles in poly (methyl methacrylate. The samples produced were characterized by X-ray diffraction, infrared spectroscopy and scanning electron microscopy. Mechanical properties were evaluated by a three point bending test. Samples were also submitted to in vitro bioactivity test and in vivo toxicity test. Results showed that the production of the composites was successfully achieved, yielding materials with particles well dispersed within the matrices. Evaluation of the in vivo inflammatory response showed low activity levels for all composites although composites with silane treated BCP particles led to milder inflammatory responses than composites with non-treated particles.

  3. Measurement of double differential cross sections of charged particle emission reactions by incident DT neutrons. Correction for energy loss of charged particle in sample materials

    International Nuclear Information System (INIS)

    Takagi, Hiroyuki; Terada, Yasuaki; Murata, Isao; Takahashi, Akito

    2000-01-01

    In the measurement of charged particle emission spectrum induced by neutrons, correcting the energy loss of charged particle in sample materials becomes a very important inverse problem. To deal with this inverse problem, we have applied the Bayesian unfolding method to correct the energy loss, and tested the performance of the method. Although this method is very simple, it was confirmed from the test that the performance was not inferior to other methods at all, and therefore the method could be a powerful tool for charged particle spectrum measurement. (author)

  4. Motions of charged particles in Goedel-type spacetimes

    International Nuclear Information System (INIS)

    Figueiredo, Bartolomeu D.B.

    1996-10-01

    Goedel-type spacetimes in Hehl's non propagating torsion theory are reconsidered by supposing that the curvature source is a Weyssenhoff-Raab fluid and an electromagnetic field. The electromagnetic field implies space time homogeneity and admits a dual interpretation. From the trajectories of the test particles, it is shown that there is a class of such spacetimes for which charged particles can reach regions inaccessible to neutral particles or even photons. (author). 21 refs., 1 fig

  5. Parallel pic plasma simulation through particle decomposition techniques

    International Nuclear Information System (INIS)

    Briguglio, S.; Vlad, G.; Di Martino, B.; Naples, Univ. 'Federico II'

    1998-02-01

    Particle-in-cell (PIC) codes are among the major candidates to yield a satisfactory description of the detail of kinetic effects, such as the resonant wave-particle interaction, relevant in determining the transport mechanism in magnetically confined plasmas. A significant improvement of the simulation performance of such codes con be expected from parallelization, e.g., by distributing the particle population among several parallel processors. Parallelization of a hybrid magnetohydrodynamic-gyrokinetic code has been accomplished within the High Performance Fortran (HPF) framework, and tested on the IBM SP2 parallel system, using a 'particle decomposition' technique. The adopted technique requires a moderate effort in porting the code in parallel form and results in intrinsic load balancing and modest inter processor communication. The performance tests obtained confirm the hypothesis of high effectiveness of the strategy, if targeted towards moderately parallel architectures. Optimal use of resources is also discussed with reference to a specific physics problem [it

  6. Searching for axion-like particles with active-galactic nuclei

    International Nuclear Information System (INIS)

    Burrage, Clare; Davis, Anne-Christine; Shaw, Douglas J.

    2009-12-01

    Strong mixing between photons and axion-like particles in the magnetic fields of clusters of galaxies induces a scatter in the observed luminosities of compact sources in the cluster. This is used to construct a new test for axion-like particles; applied to observations of active galactic nuclei it is strongly suggestive of the existence of a light axion-like particle. (orig.)

  7. Interim development report: engineering-scale HTGR fuel particle crusher

    International Nuclear Information System (INIS)

    Baer, J.W.; Strand, J.B.

    1978-09-01

    During the reprocessing of HTGR fuel, a double-roll crusher is used to fracture the silicon carbide coatings on the fuel particles. This report describes the development of the roll crusher used for crushing Fort-St.Vrain type fissile and fertile fuel particles, and large high-temperature gas-cooled reactor (LHTGR) fissile fuel particles. Recommendations are made for design improvements and further testing

  8. Searching for axion-like particles with active-galactic nuclei

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, Clare [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Davis, Anne-Christine [Centre for Mathematical Sciences, Cambridge (United Kingdom). Dept. of Applied Mathematics and Theoretical Physics; Shaw, Douglas J. [Queen Mary Univ. of London (United Kingdom). Astronomy Unit, School of Mathematical Sciences

    2009-12-15

    Strong mixing between photons and axion-like particles in the magnetic fields of clusters of galaxies induces a scatter in the observed luminosities of compact sources in the cluster. This is used to construct a new test for axion-like particles; applied to observations of active galactic nuclei it is strongly suggestive of the existence of a light axion-like particle. (orig.)

  9. Effect of indirect non-thermal plasma on particle size distribution and composition of diesel engine particles

    Science.gov (United States)

    Linbo, GU; Yixi, CAI; Yunxi, SHI; Jing, WANG; Xiaoyu, PU; Jing, TIAN; Runlin, FAN

    2017-11-01

    To explore the effect of the gas source flow rate on the actual diesel exhaust particulate matter (PM), a test bench for diesel engine exhaust purification was constructed, using indirect non-thermal plasma technology. The effects of different gas source flow rates on the quantity concentration, composition, and apparent activation energy of PM were investigated, using an engine exhaust particle sizer and a thermo-gravimetric analyzer. The results show that when the gas source flow rate was large, not only the maximum peak quantity concentrations of particles had a large drop, but also the peak quantity concentrations shifted to smaller particle sizes from 100 nm to 80 nm. When the gas source flow rate was 10 L min-1, the total quantity concentration greatly decreased where the removal rate of particles was 79.2%, and the variation of the different mode particle proportion was obvious. Non-thermal plasma (NTP) improved the oxidation ability of volatile matter as well as that of solid carbon. However, the NTP gas source rate had little effects on oxidation activity of volatile matter, while it strongly influenced the oxidation activity of solid carbon. Considering the quantity concentration and oxidation activity of particles, a gas source flow rate of 10 L min-1 was more appropriate for the purification of particles.

  10. New preamplifier for particle detectors

    International Nuclear Information System (INIS)

    Yarema, R.J.

    1984-11-01

    A new preamplifier for particle detectors has been designed and built for the Fermilab VTPC by Fujitsu of Japan. The device, designated MB43458, is a semi-custom monolithic assembled in a small, low mass package. The purpose of this report is to document the preliminary tests which have been done thus far. Tests are continuing to expand upon the results presented herein

  11. Particle interpretations of the PVLAS data

    International Nuclear Information System (INIS)

    Ringwald, A.

    2007-04-01

    Recently the PVLAS collaboration reported the observation of a rotation of linearly polarized laser light induced by a transverse magnetic field - a signal being unexpected within standard QED. In this review, we emphasize two mechanisms which have been proposed to explain this result: production of a single light neutral spin-zero particle or pair production of light minicharged particles. We discuss a class of models, involving, in addition to our familiar ''visible'' photon, further light ''hidden paraphotons'', which mix kinematically with the visible one, and further light paracharged particles. In these models, very strong astrophysical and cosmological bounds on the weakly interacting light particles mentioned above can be evaded. In the upcoming year, a number of decisive laboratory based tests of the particle interpretation of the PVLAS anomaly will be done. More generally, such experiments, exploiting high fluxes of low-energy photons and/or large electromagnetic fields, will dig into previously unconstrained parameter space of the above mentioned models. (orig.)

  12. On the electrodynamics of spinning particles

    International Nuclear Information System (INIS)

    Holten, J.W. van

    1990-01-01

    The electrodynamics of spinning point particles is considered. A modification of the Lorentz force law is introduced which can be interpreted as a classical limit of the Dirac-Klein-Gordon equation. An improved version of the inhomogeneous Maxwell equations is constructed to describe the classical fields of spinning particles. Both classical and quantum electrodynamics are shown to predict relativistic time-dilatation effects for spinning particles in an electromagnetic field, even in the limit of zero velocity. The life-time of unstable charged particles moving in a Coulomb field is computed for both spin-zero and spin-half particles. Comparison shows spin effects to be present but relatively small. The magnitude of further spin-dependent correction from hyperfine interactions is computed. A measurement of the life-time of muons in atomic bound states separated by such spin-dependent hyperfine interactions would provide a clean test for the effect predicted. Similar effects are shown to arise in non-abelian gauge theories such as QCD. (author). 18 refs

  13. Charged particle scintillation mass spectrometer

    International Nuclear Information System (INIS)

    Baranov, P.S.; Zhuravlev, E.E.; Nafikov, A.A.; Osadchi , A.I.; Raevskij, V.G.; Smirnov, P.A.; Cherepnya, S.N.; Yanulis, Yu.P.

    1982-01-01

    A scintillation mass-spectrometer for charged particle identification by the measured values of time-of-flight and energy operating on line with the D-116 computer is described. Original time detectors with 100x100x2 mm 3 and 200x2 mm 2 scintillators located on the 1- or 2 m path length are used in the spectrometer. The 200x200x200 mm 3 scintillation unit is used as a E-counter. Time-of-flight spectra of the detected particles on the 2 m path length obtained in spectrometer test in the beam of charged particles escaping from the carbon target at the angle of 130 deg under 1.2 GeV bremsstrahlung beam of the ''Pakhra'' PIAS synchrotron are presented. Proton and deuteron energy spectra as well as mass spectrum of all the particles detected by the spectrometer are given. Mass resolution obtained on the 2 m path length for π-mesons is +-25%, for protons is +-5%, for deuterons is +-3%

  14. SEPARATION OF FISCHER-TROPSCH WAX PRODUCTS FROM ULTRAFINE IRON CATALYST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    James K. Neathery; Gary Jacobs; Burtron H. Davis

    2004-03-31

    In this reporting period, a fundamental filtration study was started to investigate the separation of Fischer-Tropsch Synthesis (FTS) liquids from iron-based catalyst particles. Slurry-phase FTS in slurry bubble column reactor systems is the preferred mode of production since the reaction is highly exothermic. Consequently, heavy wax products must be separated from catalyst particles before being removed from the reactor system. Achieving an efficient wax product separation from iron-based catalysts is one of the most challenging technical problems associated with slurry-phase FTS. The separation problem is further compounded by catalyst particle attrition and the formation of ultra-fine iron carbide and/or carbon particles. Existing pilot-scale equipment was modified to include a filtration test apparatus. After undergoing an extensive plant shakedown period, filtration tests with cross-flow filter modules using simulant FTS wax slurry were conducted. The focus of these early tests was to find adequate mixtures of polyethylene wax to simulate FTS wax. Catalyst particle size analysis techniques were also developed. Initial analyses of the slurry and filter permeate particles will be used by the research team to design improved filter media and cleaning strategies.

  15. Mechanical properties of epoxy/coconut shell filler particle composites

    International Nuclear Information System (INIS)

    Sapuan, S.M.; Harimi, M.; Maleque, M.A.

    2003-01-01

    This paper presents the tensile and flexural properties of composites made from coconut shell filler particles and epoxy resin. The tensile and flexural tests of composites based on coconut shell filler particles at three different filler contents viz., 5%, 0% and 15%were carried out using universal tensile testing machine according to ASTM D 3039/D M-95a and ASTM D790-90 tensile respectively and their results were presented. Experimental results showed that tensile and flexural properties of the composites increased with the increase of the filler particle content. The composite materials demonstrate somewhat linear behavior and sharp structure for tensile and slight nonlinear behavior and sharp fracture of flexural testing. The relation between stress and percentage of filler for tensile and flexural tests were found to b linear with correlation factors of 0.9929 and 0.9973 respectively. Concerning the relation between the modulus and percentage of filler for tensile and flexural tests, it was found to be a quadratic relation with the same correlation factor approximated to 1. The same behavior was observed for the strain versus percentage of filler tensile and flexural tests, with the same correlation factor. (author)

  16. Parallelization Issues and Particle-In Codes.

    Science.gov (United States)

    Elster, Anne Cathrine

    1994-01-01

    "Everything should be made as simple as possible, but not simpler." Albert Einstein. The field of parallel scientific computing has concentrated on parallelization of individual modules such as matrix solvers and factorizers. However, many applications involve several interacting modules. Our analyses of a particle-in-cell code modeling charged particles in an electric field, show that these accompanying dependencies affect data partitioning and lead to new parallelization strategies concerning processor, memory and cache utilization. Our test-bed, a KSR1, is a distributed memory machine with a globally shared addressing space. However, most of the new methods presented hold generally for hierarchical and/or distributed memory systems. We introduce a novel approach that uses dual pointers on the local particle arrays to keep the particle locations automatically partially sorted. Complexity and performance analyses with accompanying KSR benchmarks, have been included for both this scheme and for the traditional replicated grids approach. The latter approach maintains load-balance with respect to particles. However, our results demonstrate it fails to scale properly for problems with large grids (say, greater than 128-by-128) running on as few as 15 KSR nodes, since the extra storage and computation time associated with adding the grid copies, becomes significant. Our grid partitioning scheme, although harder to implement, does not need to replicate the whole grid. Consequently, it scales well for large problems on highly parallel systems. It may, however, require load balancing schemes for non-uniform particle distributions. Our dual pointer approach may facilitate this through dynamically partitioned grids. We also introduce hierarchical data structures that store neighboring grid-points within the same cache -line by reordering the grid indexing. This alignment produces a 25% savings in cache-hits for a 4-by-4 cache. A consideration of the input data's effect on

  17. Passive target tracking using marginalized particle filter

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A marginalized particle filtering(MPF)approach is proposed for target tracking under the background of passive measurement.Essentially,the MPF is a combination of particle filtering technique and Kalman filter.By making full use of marginalization,the distributions of the tractable linear part of the total state variables are updated analytically using Kalman filter,and only the lower-dimensional nonlinear state variable needs to be dealt with using particle filter.Simulation studies are performed on an illustrative example,and the results show that the MPF method leads to a significant reduction of the tracking errors when compared with the direct particle implementation.Real data test results also validate the effectiveness of the presented method.

  18. Transverse momentum distributions and particle correlations from EMU05

    International Nuclear Information System (INIS)

    Takahashi, Y.; Chan, C.H.; Duthie, J.G.; Gregory, J.C.; Hayashi, T.; Iyono, A.; Ogata, T.; Miyamura, O.

    1989-01-01

    Transverse momentum distributions and multi-particle correlations of charged particles in 200 GeV/AMU heavy-ion collisions are studied with the Magnetic-Interferometric-Emulsion-Chamber (MAGIC) for central collisions events in 16 O+Pb and 32 S+Pb interactions. The P T distribution of negative-charged particles below 1 GeV/c fits a single exponential, while that of positive particles contains additional contributions of both high- and low-p T particles. The like-sign, two particle correlations indicate HBT interferences, while that of the unlike-sign pairs possibly suggests other components. The apparent, multi-particle, charge-sign clustering is studied with the run-test and with Monte Carlo simulations. Some of the data are consistent with chance coincidence and the HBT interference. (orig.)

  19. Continuous air monitor for alpha-emitting aerosol particles

    International Nuclear Information System (INIS)

    McFarland, A.R.; Ortiz, C.A.; Rodgers, J.C.; Nelson, D.C.

    1991-01-01

    A new alpha continuous air monitor (CAM) sampler is being developed for use in detecting the presence of alpha-emitting aerosol particles. The effort involves design, fabrication and evaluation of systems for the collection of aerosol and for the processing of data to speciate and quantify the alpha emitters of the interest. At the present time the authors have a prototype of the aerosol sampling system and they have performed wind tunnel tests to characterize the performance of the device for different particle sizes, wind speeds, flow rates and internal design parameters. The results presented herein deal with the aerosol sampling aspects of the new CAM sampler. Wind tunnel tests show that ≥ 50% of 10 μm aerodynamic equivalent diameter (AED) particles penetrate the flow system from the ambient air to the collection filter when the flow rate is 57 L/min (2 cfm) and the wind speed is 1 m/s. The coefficient of variation of deposits of 10 μm AED aerosol particles on the collection filter is 7%. An inlet fractionator for removing high mobility background aerosol particles has been designed and successfully tested. The results show that it is possible to strip 95% of freshly formed radon daughters and 33% of partially aged radon daughters from the aerosol sample. This approach offers the opportunity to improve the signal-to-noise ratio in the alpha energy spectrum region of interest thereby enhancing the performance of background compensation algorithms

  20. TSI Model 3936 Scanning Mobility Particle Spectrometer Instrument Handbook

    Energy Technology Data Exchange (ETDEWEB)

    Kuang, C. [Brookhaven National Lab. (BNL), Upton, NY (United States)

    2016-02-01

    The Model 3936 Scanning Mobility Particle Spectrometer (SMPS) measures the size distribution of aerosols ranging from 10 nm up to 1000 nm. The SMPS uses a bipolar aerosol charger to keep particles within a known charge distribution. Charged particles are classified according to their electrical mobility, using a long-column differential mobility analyzer (DMA). Particle concentration is measured with a condensation particle counter (CPC). The SMPS is well-suited for applications including: nanoparticle research, atmospheric aerosol studies, pollution studies, smog chamber evaluations, engine exhaust and combustion studies, materials synthesis, filter efficiency testing, nucleation/condensation studies, and rapidly changing aerosol systems.

  1. General relativistic variation formalism for a probe particle with momenta

    Energy Technology Data Exchange (ETDEWEB)

    Minkevich, A V; Sokol' skii, A A [Belorusskij Gosudarstvennyj Univ., Minsk

    1975-01-01

    On the basis of a model of an oriental particle a variational formalism was developed for a rotating test particle having momenta and moving in inhomogeneous space-time: the Lagrange equations for translational and rotational motion were obtained, and a metric pulse energy tensor was found. The formalism applies to a charged rotating particle with an electrical and a magnetic moment and a rotating particle in space with curvature and torsion.

  2. Transfer of hydrophobic contaminants in urban runoff particles to benthic organisms estimated by an in vitro bioaccessibility test

    DEFF Research Database (Denmark)

    Nakajima, F.; Saito, K.; Isozaki, Y.

    2006-01-01

    An in vitro bioaccessibility test was applied for assessing the transfer of polycyclic aromatic hydrocarbons (PAHs) present in road dust, into benthic organisms living in a receiving water body. The road dust is supposed to be urban runoff particles under wet weather conditions. Sodium dodecyl...... sulfate (SDS) solution was used as a hypothetical gut fluid. Pyrene, fluoranthene and phenanthrene were the main PAH species in the SIDS extractable fraction of road dust, as well as the whole extract. Benzo(ghi)perylene showed relatively low concentrations in the SIDS extract in spite of a high...... concentration in the original dust. The PAH composition in benthic organisms (polychaetes) did not correspond with that of the surrounding sediment and the PAHs detected were also detected in high concentrations in the SDS extract of road dust. When testing the toxicity of the extracted contaminants...

  3. Comments on the soluble particle identification by the spot test technique

    International Nuclear Information System (INIS)

    Podzimek, Josef

    2000-01-01

    The results of old and new measurements of salt nuclei are reviewed in order to estimate the effects of particle size and of environmental humidity or temperature on the size distribution of potential cloud condensation nuclei. Several possible improvements of the sampling and evaluation technique are discussed

  4. Tuning and Test of Fragmentation Models Based on Identified Particles and Precision Event Shape Data

    CERN Document Server

    Abreu, P; Adye, T; Ajinenko, I; Alekseev, G D; Alemany, R; Allport, P P; Almehed, S; Amaldi, Ugo; Amato, S; Andreazza, A; Andrieux, M L; Antilogus, P; Apel, W D; Åsman, B; Augustin, J E; Augustinus, A; Baillon, Paul; Bambade, P; Barão, F; Barate, R; Barbi, M S; Bardin, Dimitri Yuri; Baroncelli, A; Bärring, O; Barrio, J A; Bartl, Walter; Bates, M J; Battaglia, Marco; Baubillier, M; Baudot, J; Becks, K H; Begalli, M; Beillière, P; Belokopytov, Yu A; Belous, K S; Benvenuti, Alberto C; Berggren, M; Bertini, D; Bertrand, D; Besançon, M; Bianchi, F; Bigi, M; Bilenky, S M; Billoir, P; Bloch, D; Blume, M; Bolognese, T; Bonesini, M; Bonivento, W; Booth, P S L; Bosio, C; Botner, O; Boudinov, E; Bouquet, B; Bourdarios, C; Bowcock, T J V; Bozzo, M; Branchini, P; Brand, K D; Brenke, T; Brenner, R A; Bricman, C; Brown, R C A; Brückman, P; Brunet, J M; Bugge, L; Buran, T; Burgsmüller, T; Buschmann, P; Buys, A; Cabrera, S; Caccia, M; Calvi, M; Camacho-Rozas, A J; Camporesi, T; Canale, V; Canepa, M; Cankocak, K; Cao, F; Carena, F; Carroll, L; Caso, Carlo; Castillo-Gimenez, M V; Cattai, A; Cavallo, F R; Chabaud, V; Charpentier, P; Chaussard, L; Checchia, P; Chelkov, G A; Chen, M; Chierici, R; Chliapnikov, P V; Chochula, P; Chorowicz, V; Chudoba, J; Cindro, V; Collins, P; Contreras, J L; Contri, R; Cortina, E; Cosme, G; Cossutti, F; Cowell, J H; Crawley, H B; Crennell, D J; Crosetti, G; Cuevas-Maestro, J; Czellar, S; Dahl-Jensen, Erik; Dahm, J; D'Almagne, B; Dam, M; Damgaard, G; Dauncey, P D; Davenport, Martyn; Da Silva, W; Defoix, C; Deghorain, A; Della Ricca, G; Delpierre, P A; Demaria, N; De Angelis, A; de Boer, Wim; De Brabandere, S; De Clercq, C; La Vaissière, C de; De Lotto, B; De Min, A; De Paula, L S; De Saint-Jean, C; Dijkstra, H; Di Ciaccio, Lucia; Di Diodato, A; Djama, F; Dolbeau, J; Dönszelmann, M; Doroba, K; Dracos, M; Drees, J; Drees, K A; Dris, M; Durand, J D; Edsall, D M; Ehret, R; Eigen, G; Ekelöf, T J C; Ekspong, Gösta; Elsing, M; Engel, J P; Erzen, B; Espirito-Santo, M C; Falk, E; Fassouliotis, D; Feindt, Michael; Ferrer, A; Fichet, S; Filippas-Tassos, A; Firestone, A; Fischer, P A; Föth, H; Fokitis, E; Fontanelli, F; Formenti, F; Franek, B J; Frenkiel, P; Fries, D E C; Frodesen, A G; Frühwirth, R; Fulda-Quenzer, F; Fuster, J A; Galloni, A; Gamba, D; Gandelman, M; García, C; García, J; Gaspar, C; Gasparini, U; Gavillet, P; Gazis, E N; Gelé, D; Gerber, J P; Gokieli, R; Golob, B; Gopal, Gian P; Gorn, L; Górski, M; Guz, Yu; Gracco, Valerio; Graziani, E; Green, C; Grefrath, A; Gris, P; Grosdidier, G; Grzelak, K; Gumenyuk, S A; Gunnarsson, P; Günther, M; Guy, J; Hahn, F; Hahn, S; Hajduk, Z; Hallgren, A; Hamacher, K; Harris, F J; Hedberg, V; Henriques, R P; Hernández, J J; Herquet, P; Herr, H; Hessing, T L; Higón, E; Hilke, Hans Jürgen; Hill, T S; Holmgren, S O; Holt, P J; Holthuizen, D J; Hoorelbeke, S; Houlden, M A; Hrubec, Josef; Huet, K; Hultqvist, K; Jackson, J N; Jacobsson, R; Jalocha, P; Janik, R; Jarlskog, C; Jarlskog, G; Jarry, P; Jean-Marie, B; Johansson, E K; Jönsson, L B; Jönsson, P E; Joram, Christian; Juillot, P; Kaiser, M; Kapusta, F; Karafasoulis, K; Karlsson, M; Karvelas, E; Katsanevas, S; Katsoufis, E C; Keränen, R; Khokhlov, Yu A; Khomenko, B A; Khovanskii, N N; King, B J; Kjaer, N J; Klapp, O; Klein, H; Klovning, A; Kluit, P M; Köne, B; Kokkinias, P; Koratzinos, M; Korcyl, K; Kostyukhin, V; Kourkoumelis, C; Kuznetsov, O; Kreuter, C; Kronkvist, I J; Krumshtein, Z; Krupinski, W; Kubinec, P; Kucewicz, W; Kurvinen, K L; Lacasta, C; Laktineh, I; Lamsa, J; Lanceri, L; Lane, D W; Langefeld, P; Lapin, V; Laugier, J P; Lauhakangas, R; Leder, Gerhard; Ledroit, F; Lefébure, V; Legan, C K; Leitner, R; Lemonne, J; Lenzen, Georg; Lepeltier, V; Lesiak, T; Libby, J; Liko, D; Lindner, R; Lipniacka, A; Lippi, I; Lörstad, B; Loken, J G; López, J M; Loukas, D; Lutz, P; Lyons, L; Naughton, J M; Maehlum, G; Mahon, J R; Maio, A; Malmgren, T G M; Malychev, V; Mandl, F; Marco, J; Marco, R P; Maréchal, B; Margoni, M; Marin, J C; Mariotti, C; Markou, A; Martínez-Rivero, C; Martínez-Vidal, F; Martí i García, S; Masik, J; Matorras, F; Matteuzzi, C; Matthiae, Giorgio; Mazzucato, M; McCubbin, M L; McKay, R; McNulty, R; Medbo, J; Merk, M; Meroni, C; Meyer, S; Meyer, W T; Myagkov, A; Michelotto, M; Migliore, E; Mirabito, L; Mitaroff, Winfried A; Mjörnmark, U; Moa, T; Møller, R; Mönig, K; Monge, M R; Morettini, P; Müller, H; Mulders, M; Mundim, L M; Murray, W J; Muryn, B; Myatt, Gerald; Naraghi, F; Navarria, Francesco Luigi; Navas, S; Nawrocki, K; Negri, P; Neumann, W; Neumeister, N; Nicolaidou, R; Nielsen, B S; Nieuwenhuizen, M; Nikolaenko, V; Niss, P; Nomerotski, A; Normand, Ainsley; Oberschulte-Beckmann, W; Obraztsov, V F; Olshevskii, A G; Onofre, A; Orava, Risto; Österberg, K; Ouraou, A; Paganini, P; Paganoni, M; Pagès, P; Pain, R; Palka, H; Papadopoulou, T D; Papageorgiou, K; Pape, L; Parkes, C; Parodi, F; Passeri, A; Pegoraro, M; Peralta, L; Pernegger, H; Pernicka, Manfred; Perrotta, A; Petridou, C; Petrolini, A; Petrovykh, M; Phillips, H T; Piana, G; Pierre, F; Plaszczynski, S; Podobrin, O; Pol, M E; Polok, G; Poropat, P; Pozdnyakov, V; Privitera, P; Pukhaeva, N; Pullia, Antonio; Radojicic, D; Ragazzi, S; Rahmani, H; Rames, J; Ratoff, P N; Read, A L; Reale, M; Rebecchi, P; Redaelli, N G; Regler, Meinhard; Reid, D; Renton, P B; Resvanis, L K; Richard, F; Richardson, J; Rídky, J; Rinaudo, G; Ripp, I; Romero, A; Roncagliolo, I; Ronchese, P; Roos, L; Rosenberg, E I; Rosso, E; Roudeau, Patrick; Rovelli, T; Rückstuhl, W; Ruhlmann-Kleider, V; Ruiz, A; Rybicki, K; Saarikko, H; Sacquin, Yu; Sadovskii, A; Sahr, O; Sajot, G; Salt, J; Sánchez, J; Sannino, M; Schimmelpfennig, M; Schneider, H; Schwickerath, U; Schyns, M A E; Sciolla, G; Scuri, F; Seager, P; Sedykh, Yu; Segar, A M; Seitz, A; Sekulin, R L; Serbelloni, L; Shellard, R C; Siegrist, P; Silvestre, R; Simonetti, S; Simonetto, F; Sissakian, A N; Sitár, B; Skaali, T B; Smadja, G; Smirnov, N; Smirnova, O G; Smith, G R; Sokolov, A; Sosnowski, R; Souza-Santos, D; Spassoff, Tz; Spiriti, E; Sponholz, P; Squarcia, S; Stanescu, C; Stapnes, Steinar; Stavitski, I; Stevenson, K; Stichelbaut, F; Stocchi, A; Strauss, J; Strub, R; Stugu, B; Szczekowski, M; Szeptycka, M; Tabarelli de Fatis, T; Tavernet, J P; Chikilev, O G; Thomas, J; Tilquin, A; Timmermans, J; Tkatchev, L G; Todorov, T; Todorova, S; Toet, D Z; Tomaradze, A G; Tomé, B; Tonazzo, A; Tortora, L; Tranströmer, G; Treille, D; Trischuk, W; Tristram, G; Trombini, A; Troncon, C; Tsirou, A L; Turluer, M L; Tyapkin, I A; Tyndel, M; Tzamarias, S; Überschär, B; Ullaland, O; Uvarov, V; Valenti, G; Vallazza, E; van Apeldoorn, G W; van Dam, P; Van Eldik, J; Vassilopoulos, N; Vegni, G; Ventura, L; Venus, W A; Verbeure, F; Verlato, M; Vertogradov, L S; Vilanova, D; Vincent, P; Vitale, L; Vlasov, E; Vodopyanov, A S; Vrba, V; Wahlen, H; Walck, C; Waldner, F; Weierstall, M; Weilhammer, Peter; Weiser, C; Wetherell, Alan M; Wicke, D; Wickens, J H; Wielers, M; Wilkinson, G R; Williams, W S C; Winter, M; Witek, M; Woschnagg, K; Yip, K; Yushchenko, O P; Zach, F; Zaitsev, A; Zalewska-Bak, A; Zalewski, Piotr; Zavrtanik, D; Zevgolatakos, E; Zimin, N I; Zito, M; Zontar, D; Zucchelli, G C; Zumerle, G

    1996-01-01

    Event shape and charged particle inclusive distributions are measured using 750000 decays of the $Z$ to hadrons from the DELPHI detector at LEP. These precise data allow a decisive confrontation with models of the hadronization process. Improved tunings of the JETSET ARIADNE and HERWIG parton shower models and the JETSET matrix element model are obtained by fitting the models to these DELPHI data as well as to identified particle distributions from all LEP experiments. The description of the data distributions by the models is critically reviewed with special importance attributed to identified particles.

  5. Quenching of Particle-Gas Combustible Mixtures Using Electric Particulate Suspension (EPS) and Dispersion Methods

    Science.gov (United States)

    Colver, Gerald M.; Goroshin, Samuel; Lee, John H. S.

    2001-01-01

    A cooperative study is being carried out between Iowa State University and McGill University. The new study concerns wall and particle quenching effects in particle-gas mixtures. The primary objective is to measure and interpret flame quenching distances, flammability limits, and burning velocities in particulate suspensions. A secondary objective is to measure particle slip velocities and particle velocity distribution as these influence flame propagation. Two suspension techniques will be utilized and compared: (1) electric particle suspension/EPS; and (2) flow dispersion. Microgravity tests will permit testing of larger particles and higher and more uniform dust concentrations than is possible in normal gravity.

  6. Waste Slurry Particle Properties for Use in Slurry Flow Modeling

    Energy Technology Data Exchange (ETDEWEB)

    Jewett, J. R.; Conrads, T. J.; Julyk, L. J.; Reynolds, D. A.; Jensen, L.; Kirch, N. W.; Estey, S. D.; Bechtold, D. B.; Callaway III, W. S.; Cooke, G. A.; Herting, D. L.; Person, J. C.; Duncan, J. B.; Onishi, Y.; Tingey, J. M.

    2003-02-26

    Hanford's tank farm piping system must be substantially modified to deliver high-level wastes from the underground storage tanks to the Waste Treatment Plant now under construction. Improved knowledge of the physical properties of the solids was required to support the design of the modified system. To provide this additional knowledge, particle size distributions for composite samples from seven high-level waste feed tanks were measured using two different laser lightscattering particle size analyzers. These measurements were made under a variety of instrumental conditions, including various flow rates through the sample loop, various stirring rates in the sample reservoir, and before and after subjecting the particles to ultrasonic energy. A mean value over all the tanks of 4.2 {micro}m was obtained for the volume-based median particle size. Additional particle size information was obtained from sieving tests, settling tests and microscopic observations.

  7. Motions of charged particles in Goedel-type spacetimes

    Energy Technology Data Exchange (ETDEWEB)

    Figueiredo, Bartolomeu D.B. [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil)

    1996-10-01

    Goedel-type spacetimes in Hehl`s non propagating torsion theory are reconsidered by supposing that the curvature source is a Weyssenhoff-Raab fluid and an electromagnetic field. The electromagnetic field implies space time homogeneity and admits a dual interpretation. From the trajectories of the test particles, it is shown that there is a class of such spacetimes for which charged particles can reach regions inaccessible to neutral particles or even photons. (author). 21 refs., 1 fig.

  8. Influence of particle shape on the microstructure evolution and the mechanical properties of granular materials

    Science.gov (United States)

    Tian, Jianqiu; Liu, Enlong; Jiang, Lian; Jiang, Xiaoqiong; Sun, Yi; Xu, Ran

    2018-06-01

    In order to study the influence of particle shape on the microstructure evolution and the mechanical properties of granular materials, a two-dimensional DEM analysis of samples with three particle shapes, including circular particles, triangular particles, and elongated particles, is proposed here to simulate the direct shear tests of coarse-grained soils. For the numerical test results, analyses are conducted in terms of particle rotations, fabric evolution, and average path length evolution. A modified Rowe's stress-dilatancy equation is also proposed and successfully fitted onto simulation data.

  9. Control of respirable particles and radon progeny with portable air cleaners

    International Nuclear Information System (INIS)

    Offermann, F.J.; Sextro, R.G.; Fisk, W.J.; Nazaroff, W.W.; Nero, A.V.; Revzan, K.L.; Yater, J.

    1984-02-01

    Eleven portable air cleaning devices have been evaluated for control of indoor concentrations of respirable particles and radon progeny. Following injection of cigarette smoke and radon in a room-size chamber, decay rates for particles and radon progeny concentrations were measured with and without air cleaner operation. Particle concentrations were obtained for total number concentration and for number concentration by particle size. In tests with no air cleaner the natural decay rate for cigarette smoke was observed to be 0.2 hr -1 . Air cleaning rates for particles were found to be negligible for several small panel-filters, a residential ion-generator, and a pair of mixing fans. The electrostatic precipitators and extended surface filters tested had significant particle removal rates, and a HEPA-type filter was the most efficient air cleaner. The evaluation of radon progeny control produced similar results; the air cleaners which were effective in removing particles were also effective in removing radon progeny. At low particle concentrations plateout of the unattached radon progeny is an important removal mechanism. Based on data from these tests, the plateout rate for unattached progeny was found to be 15 hr -1 . The unattached fraction and the overall removal rate due to deposition of attached and unattached nuclides have been estimated for each radon decay product as a function of particle concentration. While air cleaning can be effective in reducing total radon progeny, concentrations of unattached radon progeny can increase with increasing air cleaning. 39 references, 26 figures, 9 tables

  10. Cosmology and particle physics

    International Nuclear Information System (INIS)

    Salati, P.

    1986-01-01

    If the hot Big Bang model is correct, the very early universe provides us with a good laboratory to test our ideas on particle physics. The temperature and the density at that time are so high that each known particle must exist in chemical and in thermal equilibrium with the others. When the universe cools, the particles freeze out, leaving us today with a cosmic background. Such a kind of relic is of great interest because we can probe the Big Bang Model by studying the fossilized gas of a known particle. Conversely we can use that model to derive information about a hypothetical particle. Basically the freezing of a gas occurs a temperature T o and may be thermal or chemical. Studying the decoupling of a stable neutrino brings information on its mass: if the mass M ν lies in the forbidden range, the neutrino has to be unstable and its lifetime is constrained by cosmology. As for the G.U.T. Monopole, cosmology tells us that its present mass density is either to big or to small (1 monopole/observable universe) owing to a predicted flux far from the Parker Limit. Finally, the super red-giant star life time constrains the axion or the Higgs to be more massive than .2 MeV [fr

  11. Numerical sedimentation particle-size analysis using the Discrete Element Method

    Science.gov (United States)

    Bravo, R.; Pérez-Aparicio, J. L.; Gómez-Hernández, J. J.

    2015-12-01

    Sedimentation tests are widely used to determine the particle size distribution of a granular sample. In this work, the Discrete Element Method interacts with the simulation of flow using the well known one-way-coupling method, a computationally affordable approach for the time-consuming numerical simulation of the hydrometer, buoyancy and pipette sedimentation tests. These tests are used in the laboratory to determine the particle-size distribution of fine-grained aggregates. Five samples with different particle-size distributions are modeled by about six million rigid spheres projected on two-dimensions, with diameters ranging from 2.5 ×10-6 m to 70 ×10-6 m, forming a water suspension in a sedimentation cylinder. DEM simulates the particle's movement considering laminar flow interactions of buoyant, drag and lubrication forces. The simulation provides the temporal/spatial distributions of densities and concentrations of the suspension. The numerical simulations cannot replace the laboratory tests since they need the final granulometry as initial data, but, as the results show, these simulations can identify the strong and weak points of each method and eventually recommend useful variations and draw conclusions on their validity, aspects very difficult to achieve in the laboratory.

  12. Numerical investigation of the influence of particle-particle and particle-wall collisions in turbulent wall-bounded flows at high mass loadings

    International Nuclear Information System (INIS)

    Alletto, Michael

    2014-01-01

    collisions is described in detail. With this efficient algorithm it is possible to detect the interparticle collisions with computational costs which scale linearly with the number of particles present in the computational domain. The resulting methodology is validated based on a variety of test cases. The validation process starts with two turbulent channel flows at different Reynolds numbers and one turbulent pipe flow. Using this simple test cases possible error sources can be detected easily. After that, a turbulent pipe flow is simulated, where the gravity points vertical to the mean streamwise direction. The appearance of an interesting secondary flow of second kind, for which the particles are only indirectly responsible, is analyzed in detail. In order to demonstrate the applicability of the present methodology in practically relevant turbulent flow configurations, the particle-laden cold flow in a combustion chamber model and the flow in a cyclone separator are tackled. The results are discussed in detail, compared with experimental reference data and interpreted from a physical point of view. Regarding the combustion chamber model, good agreement is found with the reference experiment. Furthermore, it is shown that the present methodology is capable to reproduce in the high mass loading case the disappearance of two stagnation points present on the axis of the low mass loading configuration. Regarding the cyclone separator flow, in the core region still some differences with the reference experiment remain.

  13. Numerical investigation of the influence of particle-particle and particle-wall collisions in turbulent wall-bounded flows at high mass loadings

    Energy Technology Data Exchange (ETDEWEB)

    Alletto, Michael

    2014-05-16

    collisions is described in detail. With this efficient algorithm it is possible to detect the interparticle collisions with computational costs which scale linearly with the number of particles present in the computational domain. The resulting methodology is validated based on a variety of test cases. The validation process starts with two turbulent channel flows at different Reynolds numbers and one turbulent pipe flow. Using this simple test cases possible error sources can be detected easily. After that, a turbulent pipe flow is simulated, where the gravity points vertical to the mean streamwise direction. The appearance of an interesting secondary flow of second kind, for which the particles are only indirectly responsible, is analyzed in detail. In order to demonstrate the applicability of the present methodology in practically relevant turbulent flow configurations, the particle-laden cold flow in a combustion chamber model and the flow in a cyclone separator are tackled. The results are discussed in detail, compared with experimental reference data and interpreted from a physical point of view. Regarding the combustion chamber model, good agreement is found with the reference experiment. Furthermore, it is shown that the present methodology is capable to reproduce in the high mass loading case the disappearance of two stagnation points present on the axis of the low mass loading configuration. Regarding the cyclone separator flow, in the core region still some differences with the reference experiment remain.

  14. Electroless nickel – phosphorus coating on crab shell particles and its characterization

    Energy Technology Data Exchange (ETDEWEB)

    Arulvel, S., E-mail: gs.arulvel.research@gmail.com; Elayaperumal, A.; Jagatheeshwaran, M.S.

    2017-04-15

    Being hydrophilic material, crab shell particles have only a limited number of applications. It is, therefore, necessary to modify the surface of the crab shell particles. To make them useful ever for the applications, the main theme we proposed in this article is to utilize crab shell particles (CSP) with the core coated with nickel phosphorus (NiP) as a shell using the electroless coating process. For dealing with serious environmental problems, utilization of waste bio-shells is always an important factor to be considered. Chelating ability of crab shell particles eliminates the surface activation in this work proceeding to the coating process. The functional group, phase structure, microstructure, chemical composition and thermal analysis of CSP and NiP/CSP were characterized using Fourier transform infra-red spectroscopy (FTIR), x-ray diffraction analyzer (XRD), scanning electron microscope (SEM), energy-dispersive x-ray spectroscopy (EDS), and thermogravimetric analysis (TGA). The combination of an amorphous and crystalline structure was exhibited by CSP and NiP/CSP. NiP/CSP has shown a better thermal stability when compared to uncoated CSP. Stability test, adsorption test, and conductivity test were conducted for the study of adsorption behavior and conductivity of the particles. CSP presented a hydrophilic property in contrast to hydrophobic NiP/CSP. NiP/CSP presented a conductivity of about 44% greater compared to the CSP without any fluctuations. - Highlights: • Utilization of crab shell waste is focused on. • NiP coating on crab shell particle is fabricated using electroless process. • Thermal analysis, stability test, adsorption test and conductivity test were done. • Organic matrix of crab shell particle favors the coating process. • Results demonstrate the characterization of CSP core – NiP shell structure.

  15. Investigation of the low-speed impact behavior of dual particle size metal matrix composites

    International Nuclear Information System (INIS)

    Cerit, Afşın Alper

    2014-01-01

    Highlights: • AA2124 matrix composites reinforced with SiC particles were manufactured. • Low-speed impact behaviors of composites were investigated. • Composites were manufactured with single (SPS) and dual particle sizes (DPS). • Impact behaviors of DPS composites are more favorable than the SPS composites. • Approximately 50–60% of input energy was absorbed by the composite samples. - Abstract: SiC-reinforced aluminum matrix composites were manufactured by powder metallurgy using either single or dual particle sized SiC powders and samples sintered under argon atmosphere. Quasi-static loading, low-speed impact tests and hardness tests were used to investigate mechanical behavior and found that dual particle size composites had improved hardness and impact performance compared to single particle size composites. Sample microstructure, particle distributions, plastic deformations and post-testing damages were examined by scanning electron microscopy and identified microstructure agglomerations in SPS composites. Impact traces were characterized by broken and missing SiC particles and plastically deformed composite areas

  16. Development of automatic flaw detection systems for magnetic particle examination

    International Nuclear Information System (INIS)

    Shirai, T.; Kimura, J.; Amako, T.

    1988-01-01

    Utilizing a video camera and an image processor, development was carried out on automatic flaw detection and discrimination techniques for the purpose of achieving automated magnetic particle examination. Following this, fluorescent wet magnetic particle examination systems for blade roots and rotor grooves of turbine rotors and the non-fluorescent dry magnetic particle examination system for butt welds, were developed. This paper describes these automatic magnetic particle examination (MT) systems and the functional test results

  17. General relativistic variation formalism for a probe particle with momenta

    International Nuclear Information System (INIS)

    Minkevich, A.V.; Sokol'skij, A.A.

    1975-01-01

    On the basis of a model of an oriental particle a variational formalism was developed for a rotating test particle having momenta and moving in inhomogeneous space-time: the Lagrange equations for translational and rotational motion were obtained, and a metric pulse energy tensor was found. The formalism applies to a charged rotating particle with an electrical and a magnetic moment and a rotating particle in space with curvature and torsion. (author)

  18. A Program to Generate a Particle Distribution from Emittance Measurements

    CERN Document Server

    Bouma, DS; Lallement, JB

    2010-01-01

    We have written a program to generate a particle distribution based on emittance measurements in x-x’ and y-y’. The accuracy of this program has been tested using real and constructed emittance measurements. Based on these tests, the distribution generated by the program can be used to accurately simulate the beam in multi-particle tracking codes, as an alternative to a Gaussian or uniform distribution.

  19. Transverse momentum distributions and particle correlations from EMU05

    International Nuclear Information System (INIS)

    Takahashi, Y.; Chan, C.H.; Duthie, J.G.

    1988-01-01

    Transverse momentum distributions and multi-particle correlations of charged particles in 200 GeV/AMU heavy-ion collisions are studied with the Magnetic-Interferometric-Emulsion-Chamber (MAGIC) for central collision events in 16 O + Pb and 32 S + Pb interactions. The P/sub T/ distribution of negative-charged particles below 1 GeV/c fits a single exponential, while that of positive particles contains additional contributions of both high and low-P/sub T/ particles. The like-sign, two particle correlations indicate HBT interferences, while that of the unlike-sign pairs possibly suggests other components. The apparent, multi-particle, charge-sign clustering is studied with the run-test and with Monte Carlo simulations. Some of the data are consistent with chance coincidence and the HBT interference. 6 refs., 6 figs

  20. Performance evaluation of different types of particle representation procedures of Particle Swarm Optimization in Job-shop Scheduling Problems

    Science.gov (United States)

    Izah Anuar, Nurul; Saptari, Adi

    2016-02-01

    This paper addresses the types of particle representation (encoding) procedures in a population-based stochastic optimization technique in solving scheduling problems known in the job-shop manufacturing environment. It intends to evaluate and compare the performance of different particle representation procedures in Particle Swarm Optimization (PSO) in the case of solving Job-shop Scheduling Problems (JSP). Particle representation procedures refer to the mapping between the particle position in PSO and the scheduling solution in JSP. It is an important step to be carried out so that each particle in PSO can represent a schedule in JSP. Three procedures such as Operation and Particle Position Sequence (OPPS), random keys representation and random-key encoding scheme are used in this study. These procedures have been tested on FT06 and FT10 benchmark problems available in the OR-Library, where the objective function is to minimize the makespan by the use of MATLAB software. Based on the experimental results, it is discovered that OPPS gives the best performance in solving both benchmark problems. The contribution of this paper is the fact that it demonstrates to the practitioners involved in complex scheduling problems that different particle representation procedures can have significant effects on the performance of PSO in solving JSP.

  1. Next generation multi-particle event generators for the MSSM

    International Nuclear Information System (INIS)

    Reuter, J.; Kilian, W.; Hagiwara, K.; Krauss, F.; Schumann, S.; Rainwater, D.

    2005-12-01

    We present a next generation of multi-particle Monte Carlo (MC) Event generators for LHC and ILC for the MSSM, namely the three program packages Madgraph/MadEvent, WHiZard/O'Mega and Sherpa/Amegic++. The interesting but difficult phenomenology of supersymmetric models at the upcoming colliders demands a corresponding complexity and maturity from simulation tools. This includes multi-particle final states, reducible and irreducible backgrounds, spin correlations, real emission of photons and gluons, etc., which are incorporated in the programs presented here. The framework of a model with such a huge particle content and as complicated as the MSSM makes strenuous tests and comparison of codes inevitable. Various tests show agreement among the three different programs; the tables of cross sections produced in these tests may serve as a future reference for other codes. Furthermore, first MSSM physics analyses performed with these programs are presented here. (orig.)

  2. Particle acceleration in regions of magnetic flux emergence: a statistical approach using test-particle- and MHD-simulations

    Science.gov (United States)

    Vlahos, Loukas; Archontis, Vasilis; Isliker, Heinz

    We consider 3D nonlinear MHD simulations of an emerging flux tube, from the convection zone into the corona, focusing on the coronal part of the simulations. We first analyze the statistical nature and spatial structure of the electric field, calculating histograms and making use of iso-contour visualizations. Then test-particle simulations are performed for electrons, in order to study heating and acceleration phenomena, as well as to determine HXR emission. This study is done by comparatively exploring quiet, turbulent explosive, and mildly explosive phases of the MHD simulations. Also, the importance of collisional and relativistic effects is assessed, and the role of the integration time is investigated. Particular aim of this project is to verify the quasi- linear assumptions made in standard transport models, and to identify possible transport effects that cannot be captured with the latter. In order to determine the relation of our results to Fermi acceleration and Fokker-Planck modeling, we determine the standard transport coefficients. After all, we find that the electric field of the MHD simulations must be downscaled in order to prevent an un-physically high degree of acceleration, and the value chosen for the scale factor strongly affects the results. In different MHD time-instances we find heating to take place, and acceleration that depends on the level of MHD turbulence. Also, acceleration appears to be a transient phenomenon, there is a kind of saturation effect, and the parallel dynamics clearly dominate the energetics. The HXR spectra are not yet really compatible with observations, we have though to further explore the scaling of the electric field and the integration times used.

  3. Deflection of light and particles by moving gravitational lenses

    International Nuclear Information System (INIS)

    Wucknitz, Olaf; Sperhake, Ulrich

    2004-01-01

    Various authors have investigated the problem of light deflection by radially moving gravitational lenses, but the results presented so far do not appear to agree on the expected deflection angles. Some publications claim a scaling of deflection angles with 1-v to first order in the radial lens velocity v, while others obtained a scaling with 1-2v. In this paper we generalize the calculations for arbitrary lens velocities and show that the first result is the correct one. We discuss the seeming inconsistency of relativistic light deflection with the classical picture of moving test particles by generalizing the lens effect to test particles of arbitrary velocity, including light as a limiting case. We show that the effect of radial motion of the lens is very different for slowly moving test particles and light and that a critical test particle velocity exists for which the motion of the lens has no effect on the deflection angle to first order. An interesting and not immediately intuitive result is obtained in the limit of a highly relativistic motion of the lens towards the observer, where the deflection angle of light reduces to zero. This phenomenon is elucidated in terms of moving refractive media. Furthermore, we discuss the dragging of inertial frames in the field of a moving lens and the corresponding Lense-Thirring precession, in order to shed more light on the geometrical effects in the surroundings of a moving mass. In a second part we discuss the effect of transversal motion on the observed redshift of lensed sources. We demonstrate how a simple kinematic calculation explains the effects for arbitrary velocities of the lens and test particles. Additionally we include the transversal motion of the source and observer to show that all three velocities can be combined into an effective relative transversal velocity similar to the approach used in microlensing studies

  4. Factors contributing to airborne particle dispersal in the operating room.

    Science.gov (United States)

    Noguchi, Chieko; Koseki, Hironobu; Horiuchi, Hidehiko; Yonekura, Akihiko; Tomita, Masato; Higuchi, Takashi; Sunagawa, Shinya; Osaki, Makoto

    2017-07-06

    Surgical-site infections due to intraoperative contamination are chiefly ascribable to airborne particles carrying microorganisms. The purpose of this study is to identify the actions that increase the number of airborne particles in the operating room. Two surgeons and two surgical nurses performed three patterns of physical movements to mimic intraoperative actions, such as preparing the instrument table, gowning and donning/doffing gloves, and preparing for total knee arthroplasty. The generation and behavior of airborne particles were filmed using a fine particle visualization system, and the number of airborne particles in 2.83 m 3 of air was counted using a laser particle counter. Each action was repeated five times, and the particle measurements were evaluated through one-way analysis of variance multiple comparison tests followed by Tukey-Kramer and Bonferroni-Dunn multiple comparison tests for post hoc analysis. Statistical significance was defined as a P value ≤ .01. A large number of airborne particles were observed while unfolding the surgical gown, removing gloves, and putting the arms through the sleeves of the gown. Although numerous airborne particles were observed while applying the stockinet and putting on large drapes for preparation of total knee arthroplasty, fewer particles (0.3-2.0 μm in size) were detected at the level of the operating table under laminar airflow compared to actions performed in a non-ventilated preoperative room (P airborne particles near a sterile area and that laminar airflow has the potential to reduce the incidence of bacterial contamination.

  5. Test beam studies of possibilities to separate particles with gamma factors above 103 with straw based Transition Radiation Detector

    Science.gov (United States)

    Belyaev, N.; Cherry, M. L.; Doronin, S. A.; Filippov, K.; Fusco, P.; Konovalov, S.; Krasnopevtsev, D.; Kramarenko, V.; Loparco, F.; Mazziotta, M. N.; Ponomarenko, D.; Pyatiizbyantseva, D.; Radomskii, R.; Rembser, C.; Romaniouk, A.; Savchenko, A.; Shulga, E.; Smirnov, S.; Smirnov, Yu; Sosnovtsev, V.; Spinelli, P.; Teterin, P.; Tikhomirov, V.; Vorobev, K.; Zhukov, K.

    2017-12-01

    Measurements of hadron production in the TeV energy range are one of the tasks of the future studies at the Large Hadron Collider (LHC). The main goal of these experiments is a study of the fundamental QCD processes at this energy range, which is very important not only for probing of the Standard Model but also for ultrahigh-energy cosmic particle physics. One of the key elements of these experiments measurements are hadron identification. The only detector technology which has a potential ability to separate hadrons in this energy range is Transition Radiation Detector (TRD) technology. TRD prototype based on straw proportional chambers combined with a specially assembled radiator has been tested at the CERN SPS accelerator beam. The test beam results and comparison with detailed Monte Carlo simulations are presented here.

  6. Particle collider magnet self-destructs

    CERN Multimedia

    Higgins, Alexander G

    2007-01-01

    "A 43-foot-long magnet for the world's largest particle collider broke "with a loud band and a cloud of dust" during a high-pressure test, and officils said Tuesday they are working to find a replacement part." (1 page)

  7. Penetration of Combustion Aerosol Particles Through Filters of NIOSH-Certified Filtering Facepiece Respirators (FFRs).

    Science.gov (United States)

    Gao, Shuang; Kim, Jinyong; Yermakov, Michael; Elmashae, Yousef; He, Xinjian; Reponen, Tiina; Grinshpun, Sergey A

    2015-01-01

    Filtering facepiece respirators (FFRs) are commonly worn by first responders, first receivers, and other exposed groups to protect against exposure to airborne particles, including those originated by combustion. Most of these FFRs are NIOSH-certified (e.g., N95-type) based on the performance testing of their filters against charge-equilibrated aerosol challenges, e.g., NaCl. However, it has not been examined if the filtration data obtained with the NaCl-challenged FFR filters adequately represent the protection against real aerosol hazards such as combustion particles. A filter sample of N95 FFR mounted on a specially designed holder was challenged with NaCl particles and three combustion aerosols generated in a test chamber by burning wood, paper, and plastic. The concentrations upstream (Cup) and downstream (Cdown) of the filter were measured with a TSI P-Trak condensation particle counter and a Grimm Nanocheck particle spectrometer. Penetration was determined as (Cdown/Cup) ×100%. Four test conditions were chosen to represent inhalation flows of 15, 30, 55, and 85 L/min. Results showed that the penetration values of combustion particles were significantly higher than those of the "model" NaCl particles (p combustion particles. Aerosol type, inhalation flow rate and particle size were significant (p combustion particles through R95 and P95 FFR filters (were tested in addition to N95) were not significantly higher than that obtained with NaCl particles. The findings were attributed to several effects, including the degradation of an N95 filter due to hydrophobic organic components generated into the air by combustion. Their interaction with fibers is anticipated to be similar to those involving "oily" particles. The findings of this study suggest that the efficiency of N95 respirator filters obtained with the NaCl aerosol challenge may not accurately predict (and rather overestimate) the filter efficiency against combustion particles.

  8. Accounting for the self-absorption of betas in cobalt-60 hot particles

    International Nuclear Information System (INIS)

    Lantz, M.W.; Steward, J.B.

    1988-01-01

    This paper reports that the assumptions used dose calculations can be overly conservative for discrete hot particles (activated satellite chips and irradiated fuel fragments) due to self-absorption of betas within the particles. Using data from tests with a Co-60 hot particle, a model is developed to estimate the dose reduction factor afforded by self-absorption in a satellite chip with a known thickness. The model can be applied indirectly using ion chamber survey instrument readings (the thickness of the particle does not have to be measured). Tests with Co-60 particles found at the Palo Verde Nuclear Generating Station verify that self-absorption is significant -- in one case, a dose reduction factor of 7 was measured in a satellite chip with a visible thickness

  9. Ultrafine particles in concrete: Influence of ultrafine particles on concrete properties and application to concrete mix design

    Energy Technology Data Exchange (ETDEWEB)

    Vogt, Carsten

    2010-07-01

    In this work, the influence of ultrafine particles on concrete properties was investigated. In the context of this work, ultrafine particles (reactive and inert materials) are particles finer than cement. Due to the development of effective superplasticizers, the incorporation of ultrafine particles in concrete is nowadays possible. Different minerals, usually considered inert, were tested. These minerals were also used in combination with reactive silica fume. The modified Andreassen model was used to optimise the particle size distribution and thus the packing density of the complete mix composition. Heat of hydration, compressive strength, shrinkage, frost resistance and the microstructure were investigated.The influence of different ultrafine inert materials on the cement hydration was investigated. The results show that most of the minerals have an accelerating effect. They provide nucleation sites for hydration products and contribute in that way to a faster dissolution of cement grains. Minerals containing calcium were found to influence the early stage of hydration as well. These minerals shortened the dormant period of the cement hydration, the effect is known from limestone filler in self-compacting concrete. In a first test series on concrete, different ultrafine inert particles were used to replace cement. That was done in several ways; with constant water content or constant w/c. The results from this test series show that the best effect is achieved when cement is replaced by suitable ultrafines while the w/c is kept constant. In doing so, the compressive strength can be increased and shrinkage can be reduced. The microstructure is improved and becomes denser with improved packing at microlevel. Efficiency factors (k values) for the ultrafine inert materials were calculated from the compressive strength results. The k values are strongly dependent on the mode of cement replacement, fineness and type of the replacement material and curing time. Drying

  10. Permeability of different size waste particles

    Directory of Open Access Journals (Sweden)

    Sabina Gavelytė

    2015-10-01

    Full Text Available The world and life style is changing, but the most popular disposal route for waste is landfill globally until now. We have to think about waste prevention and preparing for re-use or recycling firstly, according to the waste disposal hierarchy. Disposed waste to the landfill must be the last opportunity. In a landfill, during waste degradation processes leachate is formed that can potentially cause clogging of bottom drainage layers. To ensure stability of a landfill construction, the physical properties of its components have to be controlled. The hydrology of precipitation, evaporation, runoff and the hydraulic performance of the capping and liner materials are important controls of the moisture content. The water balance depends also on the waste characteristics and waste particle size distribution. The aim of this paper is to determine the hydraulic permeability in a landfill depending on the particle size distribution of municipal solid waste disposed. The lab experiment results were compared with the results calculated with DEGAS model. Samples were taken from a landfill operated for five years. The samples particle sizes are: >100 mm, 80 mm, 60 mm, 40 mm, 20 mm, 0.01 mm and <0.01 mm. The permeability test was conducted using the column test. The paper presents the results of experiment and DEGAS model water permeability with waste particle size.

  11. Combined Global MHD and Test-Particle Simulation of a Radiation Belt Storm: Comparing Depletion, Recovery and Enhancement with in Situ Measurements

    Science.gov (United States)

    Sorathia, K.; Ukhorskiy, A. Y.; Merkin, V. G.; Wiltberger, M. J.; Lyon, J.; Claudepierre, S. G.; Fennell, J. F.

    2017-12-01

    During geomagnetic storms the intensities of radiation belt electrons exhibit dramatic variability. In the main phase electron intensities exhibit deep depletion over a broad region of the outer belt. The intensities then increase during the recovery phase, often to levels that significantly exceed their pre-storm values. In this study we analyze the depletion, recovery and enhancement of radiation belt intensities during the 2013 St. Patrick's geomagnetic storm. We simulate the dynamics of high-energy electrons using our newly-developed test-particle radiation belt model (CHIMP) based on a hybrid guiding-center/Lorentz integrator and electromagnetic fields derived from high-resolution global MHD (LFM) simulations. Our approach differs from previous work in that we use MHD flow information to identify and seed test-particles into regions of strong convection in the magnetotail. We address two science questions: 1) what are the relative roles of magnetopause losses, transport-driven atmospheric precipitation, and adiabatic cooling in the radiation belt depletion during the storm main phase? and 2) to what extent can enhanced convection/mesoscale injections account for the radiation belt buildup during the recovery phase? Our analysis is based on long-term model simulation and the comparison of our model results with electron intensity measurements from the MAGEIS experiment of the Van Allen Probes mission.

  12. Particle interpretations of the PVLAS data

    Energy Technology Data Exchange (ETDEWEB)

    Ringwald, A.

    2007-04-15

    Recently the PVLAS collaboration reported the observation of a rotation of linearly polarized laser light induced by a transverse magnetic field - a signal being unexpected within standard QED. In this review, we emphasize two mechanisms which have been proposed to explain this result: production of a single light neutral spin-zero particle or pair production of light minicharged particles. We discuss a class of models, involving, in addition to our familiar ''visible'' photon, further light ''hidden paraphotons'', which mix kinematically with the visible one, and further light paracharged particles. In these models, very strong astrophysical and cosmological bounds on the weakly interacting light particles mentioned above can be evaded. In the upcoming year, a number of decisive laboratory based tests of the particle interpretation of the PVLAS anomaly will be done. More generally, such experiments, exploiting high fluxes of low-energy photons and/or large electromagnetic fields, will dig into previously unconstrained parameter space of the above mentioned models. (orig.)

  13. Simulation of deterministic energy-balance particle agglomeration in turbulent liquid-solid flows

    Science.gov (United States)

    Njobuenwu, Derrick O.; Fairweather, Michael

    2017-08-01

    An efficient technique to simulate turbulent particle-laden flow at high mass loadings within the four-way coupled simulation regime is presented. The technique implements large-eddy simulation, discrete particle simulation, a deterministic treatment of inter-particle collisions, and an energy-balanced particle agglomeration model. The algorithm to detect inter-particle collisions is such that the computational costs scale linearly with the number of particles present in the computational domain. On detection of a collision, particle agglomeration is tested based on the pre-collision kinetic energy, restitution coefficient, and van der Waals' interactions. The performance of the technique developed is tested by performing parametric studies on the influence of the restitution coefficient (en = 0.2, 0.4, 0.6, and 0.8), particle size (dp = 60, 120, 200, and 316 μm), Reynolds number (Reτ = 150, 300, and 590), and particle concentration (αp = 5.0 × 10-4, 1.0 × 10-3, and 5.0 × 10-3) on particle-particle interaction events (collision and agglomeration). The results demonstrate that the collision frequency shows a linear dependency on the restitution coefficient, while the agglomeration rate shows an inverse dependence. Collisions among smaller particles are more frequent and efficient in forming agglomerates than those of coarser particles. The particle-particle interaction events show a strong dependency on the shear Reynolds number Reτ, while increasing the particle concentration effectively enhances particle collision and agglomeration whilst having only a minor influence on the agglomeration rate. Overall, the sensitivity of the particle-particle interaction events to the selected simulation parameters is found to influence the population and distribution of the primary particles and agglomerates formed.

  14. Particle-two particle interaction in configuration space

    International Nuclear Information System (INIS)

    Kuzmichev, V.E.

    1982-07-01

    The problem if three indentical particles with zero-range two-particle interaction is considered. An explicit expression for the effective potential between one particle and the remaining two-particle system is obtained in the coordinate representation. It is shown that for arbitrary energies, at small and, for zero energy, at large distances rho between the one particle and centre of mass of the other two particles the diagonal matrix element of the effective potential is attractive and proportional to 1/rho 2 . This property of the effective potenial explains both the Thomas singularity and the Efimov effect. In the case of zero total energy of the system the general form of the solution of the three-particle integral equation is found in configuration space. (orig.)

  15. Radioactive Waste Decontamination Using Selentec Mag*SepSM Particles

    International Nuclear Information System (INIS)

    Walker, D.D.

    1998-01-01

    A sorbent containing crystalline silicotitanate (CST) tested for cesium removal from simulated Savannah River Site (SRS) soluble high activity waste showed rapid kinetics (1 h contact time) and high distribution coefficients (Kd 4000 mL/g of CST). The sorbent was prepared by Selective Environmental Technologies, Inc., (Selentec) as a MAG*SEP particle containing CST obtained from the Molecular Sieve Department of UOP, LLC, Results of preliminary tests suggest potential applications of the Selentec MAG*SEP particles to radioactive waste decontamination at SRS

  16. Test plan for glove box testing with the real-time transuranic dust monitor

    International Nuclear Information System (INIS)

    Partin, J.K.; Fincke, J.R.

    1994-10-01

    This test plan describes the objectives, instrumentation, and testing procedures used to prove the feasibility of a real-time transuranic dust monitor (RTDM). The RTDM is under development at the Idaho National Engineering Laboratory (INEL) as a Waste Characterization Technology funded by the Buried Waste Integrated Demonstration Project. The instrument is an in situ monitor that uses optical techniques to establish particle size, particle number density, and mass and species of heavy metal contamination. US Department of Energy orders mandate the assessment of radiological exposure and contamination spread during the remediation of radioactive waste. Of particular concern is heavy metal contamination of dust, both radioactive and nonradioactive. Small particles of metal, particularly the radioactive species, tend to become electrically charged and consequently attach themselves to dust particles. This airborne activated dust is a primary means of contamination transport during remediation activities, and therefore, must be continuously monitored to protect personnel involved in the operations and to control the spread of contamination. If real-time monitoring is not available there is increased likelihood of generating unacceptably high levels of contamination and being forced to shut down costly retrieval operations to decontaminate. A series of experiments are described to determine the optimal experimental design, operational parameters, and levels of detection for the RTDM. Initial screening will be performed using monodisperse particle standards to set parameters and calibrate the instrument. Additional testing will be performed using INEL soil samples spiked with a surrogate, cerium oxide, to prove the design before transporting the apparatus to the Test Reactor Area for testing with plutonium-contaminated dusts

  17. Strength of mortar containing rubber tire particle

    Science.gov (United States)

    Jusoh, M. A.; Abdullah, S. R.; Adnan, S. H.

    2018-04-01

    The main focus in this investigation is to determine the strength consist compressive and tensile strength of mortar containing rubber tire particle. In fact, from the previous study, the strength of mortar containing waste rubber tire in mortar has a slightly decreases compare to normal mortar. In this study, rubber tire particle was replacing on volume of fine aggregate with 6%. 9% and 12%. The sample were indicated M0 (0%), M6 (6%), M9 (9%) and M12 (12%). In this study, two different size of sample used with cube 100mm x 100mm x 100mm for compressive strength and 40mm x 40mm x 160mm for flexural strength. Morphology test was conducted by using Scanning electron microscopic (SEM) were done after testing compressive strength test. The concrete sample were cured for day 3, 7 and 28 before testing. Results compressive strength and flexural strength of rubber mortar shown improved compare to normal mortar.

  18. Fundamental physics in particle traps

    International Nuclear Information System (INIS)

    Quint, Wolfgang; Vogel, Manuel

    2014-01-01

    The individual topics are covered by leading experts in the respective fields of research. Provides readers with present theory and experiments in this field. A useful reference for researchers. This volume provides detailed insight into the field of precision spectroscopy and fundamental physics with particles confined in traps. It comprises experiments with electrons and positrons, protons and antiprotons, antimatter and highly charged ions, together with corresponding theoretical background. Such investigations represent stringent tests of quantum electrodynamics and the Standard model, antiparticle and antimatter research, test of fundamental symmetries, constants, and their possible variations with time and space. They are key to various aspects within metrology such as mass measurements and time standards, as well as promising to further developments in quantum information processing. The reader obtains a valuable source of information suited for beginners and experts with an interest in fundamental studies using particle traps.

  19. Experiment study of a quartz tube falling particle receiver

    Institute of Scientific and Technical Information of China (English)

    Tianjian WANG; Fengwu BAI; Shunzhou CHU; Xiliang ZHANG; Zhifeng WANG

    2017-01-01

    This paper presents an experimental evaluation of a specially designed falling particle receiver.A quartz tube was used in the design,with which the particles would not be blown away by wind.Concentrated solar radiation was absorbed and converted into thermal energy by the solid particles flowed inside the quartz tube.Several experiments were conducted to test the dynamic thermal performance of the receiver on solar furnace system.During the experiments,the maximum particle temperature rise is 212℃,with an efficiency of 61.2%,which shows a good thermal performance with a falling distance of 0.2 m in a small scale particle receiver.The average outlet particle temperature is affected by direct normal irradiance (DNI) and other factors such as wind speed.The solid particles obtain a larger viscosity with a higher temperature while smaller solid particles are easier to get stuck in the helix quartz tube.The heat capacity of the silicon carbide gets larger with the rise of particle temperature,because as the temperature of solid particles increases,the temperature rise of the silicon carbide decreases.

  20. High pulse number thermal shock tests on tungsten with steady state particle background

    Science.gov (United States)

    Wirtz, M.; Kreter, A.; Linke, J.; Loewenhoff, Th; Pintsuk, G.; Sergienko, G.; Steudel, I.; Unterberg, B.; Wessel, E.

    2017-12-01

    Thermal fatigue of metallic materials, which will be exposed to severe environmental conditions e.g. plasma facing materials in future fusion reactors, is an important issue in order to predict the life time of complete wall components. Therefore experiments in the linear plasma device PSI-2 were performed to investigate the synergistic effects of high pulse number thermal shock events (L = 0.38 GW m-2, Δt = 0.5 ms) and stationary D/He (6%) plasma particle background on the thermal fatigue behavior of tungsten. Similar to experiments with pure thermal loads, the induced microstructural and surface modifications such as recrystallization and roughening as well as crack formation become more pronounced with increasing number of thermal shock events. However, the amount of damage significantly increases for synergistic loads showing severe surface roughening, plastic deformation and erosion resulting from the degradation of the mechanical properties caused by bombardment and diffusion of D/He to the surface and the bulk of the material. Additionally, D/He induced blistering and bubble formation were observed for all tested samples, which could change the thermal and mechanical properties of near surface regions.

  1. Standard Practice for Measurement of Mechanical Properties During Charged-Particle Irradiation

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    1996-01-01

    1.1 This practice covers the performance of mechanical tests on materials being irradiated with charged particles. These tests are designed to simulate or provide understanding of, or both, the mechanical behavior of materials during exposure to neutron irradiation. Practices are described that govern the test material, the particle beam, the experimental technique, and the damage calculations. Reference should be made to other ASTM standards, especially Practice E 521. Procedures are described that are applicable to creep and creep rupture tests made in tension and torsion test modes. 1.2 The word simulation is used here in a broad sense to imply an approximation of the relevant neutron irradiation environment. The degree of conformity can range from poor to nearly exact. The intent is to produce a correspondence between one or more aspects of the neutron and charged particle irradiations such that fundamental relationships are established between irradiation or material parameters and the material respons...

  2. Fermilab | Science | Particle Physics | Benefits of Particle Physics

    Science.gov (United States)

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

  3. Velocity width of the resonant domain in wave-particle interaction

    International Nuclear Information System (INIS)

    Firpo, Marie-Christine; Doveil, Fabrice

    2002-01-01

    Wave-particle interaction is a ubiquitous physical mechanism exhibiting locality in velocity space. A single-wave Hamiltonian provides a rich model by which to study the self-consistent interaction between one electrostatic wave and N quasiresonant particles. For the simplest nonintegrable Hamiltonian coupling two particles to one wave, we analytically derive the particle velocity borders separating quasi-integrable motions from chaotic ones. These estimates are fully retrieved through computation of the largest Lyapunov exponent. For the large-N particle self-consistent case, we numerically investigate the localization of stochasticity in velocity space and test a qualitative estimate of the borders of chaos

  4. Improvement in the independence of relaxation method-based particle tracking velocimetry

    International Nuclear Information System (INIS)

    Jia, P; Wang, Y; Zhang, Y

    2013-01-01

    New techniques are developed to improve the independence of relaxation method-based particle tracking velocimetry (RM-PTV). Firstly, Delaunay tessellation (DT) is employed to form clusters of neighboring particles with similar motion in the same frame; and then a bidirectional calculation concept is adopted to improve the way of particle pairing. These new techniques are tested with both self-defined particle images and the particle image velocimetry standard synthetic particle images. The results indicate that the DT method performs well and efficiently in determining the particle clusters, and the particle pairing process is well optimized by the bidirectional calculation concept. With these methods, three computation parameters are eliminated, which makes RM-PTV more autonomous in applications. (paper)

  5. A Diversity-Guided Particle Swarm Optimizer - the ARPSO

    DEFF Research Database (Denmark)

    Vesterstrøm, Jacob Svaneborg; Riget, Jacques

    2002-01-01

    The particle swarm optimization (PSO) algorithm is a new population based search strat- egy, which has exhibited good performance on well-known numerical test problems. How- ever, on strongly multi-modal test problems the PSO tends to suffer from premature convergence. This is due to a decrease...... that the ARPSO prevents premature convergence to a high degree, but still keeps a rapid convergence like the basic PSO. Thus, it clearly outperforms the basic PSO as well as the implemented GA in multi-modal optimization. Keywords Particle Swarm Optimization, Diversity-Guided Search 1 Introduction The PSO model...

  6. On the Effects of Atmospheric Particles Contamination and Humidity on Tin Corrosion

    DEFF Research Database (Denmark)

    D’Angelo, L.; Verdingovas, V.; Ferrero, L.

    2017-01-01

    The effects of hygroscopic atmospheric particles are investigated in relation to the corrosion of tin. Surface insulation resistance test boards were directly contaminated both with ambient particles sampled in the field at Milan, Italy, and with pure saline particles generated in the laboratory....... An innovative particle deposition device was used to uniformly coat circular spots on to the test board surfaces. Deliquescence and crystallization of the water-soluble compounds were detected by observing the impedance response to varying relative humidity (RH) conditions with a gradual and continuous ramps....... The effects of the adsorption/desorption kinetics and of the temperature on the deliquescence and crystallization RH values were also investigated. Leakage current measurements at 5-V dc highlighted the ability of atmospheric particles to promote corrosion and electrochemical migration at RH levels far below...

  7. An efficient venturi scrubber system to remove submicron particles in exhaust gas.

    Science.gov (United States)

    Tsai, Chuen-Jinn; Lin, Chia-Hung; Wang, Yu-Min; Hunag, Cheng-Hsiung; Li, Shou-Nan; Wu, Zong-Xue; Wang, Feng-Cai

    2005-03-01

    An efficient venturi scrubber system making use of heterogeneous nucleation and condensational growth of particles was designed and tested to remove fine particles from the exhaust of a local scrubber where residual SiH4 gas was abated and lots of fine SiO2 particles were generated. In front of the venturi scrubber, normal-temperature fine-water mist mixes with high-temperature exhaust gas to cool it to the saturation temperature, allowing submicron particles to grow into micron sizes. The grown particles are then scrubbed efficiently in the venturi scrubber. Test results show that the present venturi scrubber system is effective for removing submicron particles. For SiO2 particles greater than 0.1microm, the removal efficiency is greater than 80-90%, depending on particle concentration. The corresponding pressure drop is relatively low. For example, the pressure drop of the venturi scrubber is approximately 15.4 +/- 2.4 cm H2O when the liquid-to-gas ratio is 1.50 L/m3. A theoretical calculation has been conducted to simulate particle growth process and the removal efficiency of the venturi scrubber. The theoretical results agree with the experimental data reasonably well when SiO2 particle diameter is greater than 0.1 microm.

  8. A New Interpretation of Alpha-particle-driven Instabilities in Deuterium-Tritium Experiments on the Tokamak Fusion Test Reactor

    International Nuclear Information System (INIS)

    R. Nazikian; G.J. Kramer; C.Z. Cheng; N.N. Gorelenkov; H.L. Berk; S.E. Sharapov

    2003-01-01

    The original description of alpha-particle-driven instabilities in the Tokamak Fusion Test Reactor (TFTR) in terms of Toroidal Alfvin Eigenmodes (TAEs) remained inconsistent with three fundamental characteristics of the observations: (i) the variation of the mode frequency with toroidal mode number, (ii) the chirping of the mode frequency for a given toroidal mode number, and (iii) the anti-ballooning density perturbation of the modes. It is now shown that these characteristics can be explained by observing that cylindrical-like modes can exist in the weak magnetic shear region of the plasma that then make a transition to TAEs as the central safety factor decreases in time

  9. Deriving Particle Distributions from In-Line Fraunhofer Holographic Data

    International Nuclear Information System (INIS)

    Ciarcia, C.A.; Johnson, D.E.; Sorenson, D.S.; Frederickson, R.H.; Delanoy, A.D.; Malone, R.M.; Tunnel, T.W.

    1997-01-01

    Holographic data are acquired during hydrodynamic experiments at the Pegasus Pulsed Power Facility at the Los Alamos National Laboratory. These experiments produce a fine spray of fast-moving particles. Snapshots of the spray are captured using in-line Fraunhofer holographic techniques. Roughly one cubic centimeter is recorded by the hologram. Minimum detectable particle size in the data extends down to 2 microns. In a holography reconstruction system, a laser illuminates the hologram as it rests in a three-axis actuator, recreating the snapshot of the experiment. A computer guides the actuators through an orderly sequence programmed by the user. At selected intervals, slices of this volume are captured and digitized with a CCD camera. Intermittent on-line processing of the image data and computer control of the camera functions optimizes statistics of the acquired image data for off-line processing. Tens of thousands of individual data frames (30 to 40 gigabytes of data) are required to recreate a digital representation of the snapshot. Throughput of the reduction system is 550 megabytes per hour (MB/hr). Objects and associated features from the data are subsequently extracted during off-line processing. Discrimination and correlation tests reject noise, eliminate multiple counting of particles, and build an error model to estimate performance. Objects surviving these tests are classified as particles. The particle distributions are derived from the data base formed by these particles, their locations and features. Throughput of the off-line processing exceeds 500 MB/hr. This paper describes the reduction system, outlines the off-line processing procedure, summarizes the discrimination and correlation tests, and reports numerical results for a sample data set

  10. Testosterone sorption and desorption: Effects of soil particle size

    Energy Technology Data Exchange (ETDEWEB)

    Qi, Yong, E-mail: yqi01@unomaha.edu [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Zhang, Tian C. [Civil Engineering Dept., University of Nebraska-Lincoln at Omaha Campus, Omaha, NE 68182 (United States); Ren, Yongzheng [School of Environmental Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2014-08-30

    Graphical abstract: - Highlights: • Smaller soil particles have higher sorption and lower desorption rates. • The sorption capacity ranks as clay > silt > sand. • Small particles like clays have less potential for desorption. • Colloids (clays) have high potential to facilitate the transport of hormones in soil–water environments. - Abstract: Soils contain a wide range of particles of different diameters with different mobility during rainfall events. Effects of soil particles on sorption and desorption behaviors of steroid hormones have not been investigated. In this study, wet sieve washing and repeated sedimentation methods were used to fractionate the soils into five ranges. The sorption and desorption properties and related mechanisms of testosterone in batch reactors filled with fractionated soil particles were evaluated. Results of sorption and desorption kinetics indicate that small soil particles have higher sorption and lower desorption rates than that of big ones. Thermodynamic results show the sorption processes are spontaneous and exothermal. The sorption capacity ranks as clay > silt > sand, depending mainly on specific surface area and surface functional groups. The urea control test shows that hydrogen bonding contributes to testosterone sorption onto clay and silt but not on sand. Desorption tests indicate sorption is 36–65% irreversible from clay to sand. Clays have highest desorption hysteresis among these five soil fractions, indicating small particles like clays have less potential for desorption. The results provide indirect evidence on the colloid (clay)-facilitated transport of hormones (micro-pollutants) in soil environments.

  11. Effect of bed particles to combustion of gases in fluidized bed

    Energy Technology Data Exchange (ETDEWEB)

    Raiko, R.; Wallen, V.; Etelaeaho, R.; Correia, S. [Tampere Univ. of Technology (Finland). Energy and Process Engineering

    1997-10-01

    The objective of this project was to obtain experimental data on effects of sand particles to the combustion of gases. The effect of the surface area of the particles was tested using different sized particles. The fluidized bed reactor used in these experiments was a stainless-steel tube with an internal diameter of 42 mm surrounded by an electric heater. The test rig was built in the Laboratory of Energy and Process Engineering at Tampere University of Technology. In order to elucidate the possible changes of particle surface, microscopic and porosimetric studies were conducted with both fresh bed particles and used bed particles. These measurements indicate that carbon monoxide significantly reacts with oxygen in the particulate or emulsion phase of a fluidized bed, if the residence time is long enough. The reaction rate depends mainly on temperature, air coefficient, residence time and particle size of the solids. It seems that the combustion enhances if the average particle size increases. Whether this is caused by increased free path length or reduced specific surface area of the bed is yet unknown. The first might be more probable cause because the majority of reactions often took place in the freeboard right above the bed. It was clear that the bed hindered proper combustion in several cases. (orig.)

  12. CASTing light on dark matter particles

    CERN Multimedia

    2005-01-01

    CERN's CAST collaboration recently released first results from its search for solar axions, a candidate dark matter particle. Though they haven't found any axions yet, they have done much to narrow the hunt. The CAST experiment. Physicists think the universe is permeated with dark matter, particles that don't emit or absorb radiation and so are invisible to traditional telescopes. So far no one has found direct signs of dark matter. A different breed of telescope, however, may be able to see such particles. CERN's Axion Solar Telescope (CAST), currently the world's only working axion helioscope, is a superconducting test magnet from the Large Hadron Collider (LHC) that has been refurbished and outfitted with X-ray detectors, plus a focusing mirror system for X-rays that was recovered from the German space program. CAST stares into the sun in search of particles called axions, one of the leading candidates for dark matter. On 9 November, the CAST collaboration released the results of their first experimen...

  13. Restraint of fatigue crack growth by wedge effects of fine particles

    CERN Document Server

    Takahashi, I; Kotani, N

    2000-01-01

    Presents some experimental results which demonstrate restraint of fatigue crack growth in an Al-Mg alloy by wedge effects of fine particles. Fatigue test specimens were machined from a JIS A5083P-O Al-Mg alloy plate of 5 mm thickness and an EDM starter notch was introduced to each specimen. Three kinds of fine particles were prepared as the materials to be wedged into the fatigue cracks, i.e. magnetic particles and two kinds of alumina particles having different mean particle sizes of 47.3 mu m and 15.2 mu m. Particles of each kind were suspended in an oil to form a paste, which was applied on the specimen surface covering the notch zone prior to the fatigue tests. In order to make some fracture mechanics approaches, in situ observations of fatigue cracks were performed for the two cases using a CCD microscope, with a magnification of *1000. The crack length and the crack opening displacement (COD) at the notch root, delta , were measured. The crack retardation effect continues almost through the entire lifet...

  14. Observation and Control of Hamiltonian Chaos in Wave-particle Interaction

    International Nuclear Information System (INIS)

    Doveil, F.; Ruzzon, A.; Elskens, Y.

    2010-01-01

    Wave-particle interactions are central in plasma physics. The paradigm beam-plasma system can be advantageously replaced by a traveling wave tube (TWT) to allow their study in a much less noisy environment. This led to detailed analysis of the self-consistent interaction between unstable waves and an either cold or warm electron beam. More recently a test cold beam has been used to observe its interaction with externally excited wave(s). This allowed observing the main features of Hamiltonian chaos and testing a new method to efficiently channel chaotic transport in phase space. To simulate accurately and efficiently the particle dynamics in the TWT and other 1D particle-wave systems, a new symplectic, symmetric, second order numerical algorithm is developed, using particle position as the independent variable, with a fixed spatial step.This contribution reviews: presentation of the TWT and its connection to plasma physics, resonant interaction of a charged particle in electrostatic waves, observation of particle trapping and transition to chaos, test of control of chaos, and description of the simulation algorithm.The velocity distribution function of the electron beam is recorded with a trochoidal energy analyzer at the output of the TWT. An arbitrary waveform generator is used to launch a prescribed spectrum of waves along the 4m long helix of the TWT. The nonlinear synchronization of particles by a single wave, responsible for Landau damping, is observed. We explore the resonant velocity domain associated with a single wave as well as the transition to large scale chaos when the resonant domains of two waves and their secondary resonances overlap. This transition exhibits a devil's staircase behavior when increasing the excitation level in agreement with numerical simulation.A new strategy for control of chaos by building barriers of transport in phase space as well as its robustness is successfully tested. The underlying concepts extend far beyond the field of

  15. Buses retrofitting with diesel particle filters: Real-world fuel economy and roadworthiness test considerations.

    Science.gov (United States)

    Fleischman, Rafael; Amiel, Ran; Czerwinski, Jan; Mayer, Andreas; Tartakovsky, Leonid

    2018-05-01

    Retrofitting older vehicles with diesel particulate filter (DPF) is a cost-effective measure to quickly and efficiently reduce particulate matter emissions. This study experimentally analyzes real-world performance of buses retrofitted with CRT DPFs. 18 in-use Euro III technology urban and intercity buses were investigated for a period of 12months. The influence of the DPF and of the vehicle natural aging on buses fuel economy are analyzed and discussed. While the effect of natural deterioration is about 1.2%-1.3%, DPF contribution to fuel economy penalty is found to be 0.6% to 1.8%, depending on the bus type. DPF filtration efficiency is analyzed throughout the study and found to be in average 96% in the size range of 23-560nm. Four different load and non-load engine operating modes are investigated on their appropriateness for roadworthiness tests. High idle is found to be the most suitable regime for PN diagnostics considering particle number filtration efficiency. Copyright © 2017. Published by Elsevier B.V.

  16. The Orion Exploration Flight Test Post Flight Solid Particle Flight Environment Inspection and Analysis

    Science.gov (United States)

    Miller, Joshua E.

    2016-01-01

    Orbital debris in the millimeter size range can pose a hazard to current and planned spacecraft due to the high relative impact speeds in Earth orbit. Fortunately, orbital debris has a relatively short life at lower altitudes due to atmospheric effects; however, at higher altitudes orbital debris can survive much longer and has resulted in a band of high flux around 700 to 1,500 km above the surface of the Earth. While large orbital debris objects are tracked via ground based observation, little information can be gathered about small particles except by returned surfaces, which until the Orion Exploration Flight Test number one (EFT-1), has only been possible for lower altitudes (400 to 500 km). The EFT-1 crew module backshell, which used a porous, ceramic tile system with surface coatings, has been inspected post-flight for potential micrometeoroid and orbital debris (MMOD) damage. This paper describes the pre- and post-flight activities of inspection, identification and analysis of six candidate MMOD impact craters from the EFT-1 mission.

  17. 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 ...

  18. Lauch of CERN particle accelerator delayed

    CERN Multimedia

    2007-01-01

    "Scientists seeking to uncover the secrets of the universe will have to wait a little longer after the CERN laboratory inSwitzerland yesterday confirmed a delay in tests of its massive new particle accelerator." (1 page)

  19. Small Particles Intact Capture Experiment (SPICE)

    Science.gov (United States)

    Nishioka, Ken-Ji; Carle, G. C.; Bunch, T. E.; Mendez, David J.; Ryder, J. T.

    1994-01-01

    The Small Particles Intact Capture Experiment (SPICE) will develop technologies and engineering techniques necessary to capture nearly intact, uncontaminated cosmic and interplanetary dust particles (IDP's). Successful capture of such particles will benefit the exobiology and planetary science communities by providing particulate samples that may have survived unaltered since the formation of the solar system. Characterization of these particles may contribute fundamental data to our knowledge of how these particles could have formed into our planet Earth and, perhaps, contributed to the beginnings of life. The term 'uncontaminated' means that captured cosmic and IDP particles are free of organic contamination from the capture process and the term 'nearly intact capture' means that their chemical and elemental components are not materially altered during capture. The key to capturing cosmic and IDP particles that are organic-contamination free and nearly intact is the capture medium. Initial screening of capture media included organic foams, multiple thin foil layers, and aerogel (a silica gel); but, with the exception of aerogel, the requirements of no contamination or nearly intact capture were not met. To ensure no contamination of particles in the capture process, high-purity aerogel was chosen. High-purity aerogel results in high clarity (visual clearness), a useful quality in detection and recovery of embedded captured particles from the aerogel. P. Tsou at the Jet Propulsion Laboratory (JPL) originally described the use of aerogel for this purpose and reported laboratory test results. He has flown aerogel as a 'GAS-can Lid' payload on STS-47 and is evaluating the results. The Timeband Capture Cell Experiment (TICCE), a Eureca 1 experiment, is also flying aerogel and is scheduled for recovery in late April.

  20. 'Nano-immuno test' for the detection of live Mycobacterium avium subspecies paratuberculosis bacilli in the milk samples using magnetic nano-particles and chromogen.

    Science.gov (United States)

    Singh, Manju; Singh, Shoor Vir; Gupta, Saurabh; Chaubey, Kundan Kumar; Stephan, Bjorn John; Sohal, Jagdip Singh; Dutta, Manali

    2018-04-26

    Early rapid detection of Mycobacterium avium subspecies paratuberculosis (MAP) bacilli in milk samples is the major challenge since traditional culture method is time consuming and laboratory dependent. We report a simple, sensitive and specific nano-technology based 'Nano-immuno test' capable of detecting viable MAP bacilli in the milk samples within 10 h. Viable MAP bacilli were captured by MAP specific antibody-conjugated magnetic nano-particles using resazurin dye as chromogen. Test was optimized using true culture positive (10-bovine and 12-goats) and true culture negative (16-bovine and 25-goats) raw milk samples. Domestic livestock species in India are endemically infected with MAP. After successful optimization, sensitivity and specificity of the 'nano-immuno test' in goats with respect to milk culture was 91.7% and 96.0%, respectively. Whereas, it was 90.0% (sensitivity) and 92.6% (specificity) with respect to IS900 PCR. In bovine milk samples, sensitivity and specificity of 'nano-immuno test' with respect to milk culture was 90.0% and 93.7%, respectively. However, with respect to IS900 PCR, the sensitivity and specificity was 88.9% and 94.1%, respectively. Test was validated with field raw milk samples (goats-258 and bovine-138) collected from domestic livestock species to detect live/viable MAP bacilli. Of 138 bovine raw milk samples screened by six diagnostic tests, 81 (58.7%) milk samples were positive for MAP infection in one or more than one diagnostic tests. Of 81 (58.7%) positive bovine raw milk samples, only 24 (17.4%) samples were detected positive for the presence of viable MAP bacilli. Of 258 goats raw milk samples screened by six diagnostic tests, 141 (54.6%) were positive for MAP infection in one or more than one test. Of 141 (54.6%) positive raw milk samples from goats, only 48 (34.0%) were detected positive for live MAP bacilli. Simplicity and efficiency of this novel 'nano-immuno test' makes it suitable for wide-scale screening of milk

  1. COLLISIONLESS SHOCKS IN A PARTIALLY IONIZED MEDIUM. I. NEUTRAL RETURN FLUX AND ITS EFFECTS ON ACCELERATION OF TEST PARTICLES

    Energy Technology Data Exchange (ETDEWEB)

    Blasi, P.; Morlino, G.; Bandiera, R.; Amato, E. [INAF-Osservatorio Astrofisico di Arcetri, Largo E. Fermi, 5, I-50125 Firenze (Italy); Caprioli, D. [Department of Astrophysical Sciences, Peyton Hall, Princeton University, Princeton, NJ 08540 (United States)

    2012-08-20

    A collisionless shock may be strongly modified by the presence of neutral atoms through the processes of charge exchange between ions and neutrals and ionization of the latter. These two processes lead to exchange of energy and momentum between charged and neutral particles both upstream and downstream of the shock. In particular, neutrals that suffer a charge exchange downstream with shock-heated ions generate high-velocity neutrals that have a finite probability of returning upstream. These neutrals might then deposit heat in the upstream plasma through ionization and charge exchange, thereby reducing the fluid Mach number. A consequence of this phenomenon, which we refer to as the neutral return flux, is a reduction of the shock compression factor and the formation of a shock precursor upstream. The scale length of the precursor is determined by the ionization and charge-exchange interaction lengths of fast neutrals moving toward upstream infinity. In the case of a shock propagating in the interstellar medium, the effects of ion-neutral interactions are especially important for shock velocities <3000 km s{sup -1}. Such propagation velocities are common among shocks associated with supernova remnants, the primary candidate sources for the acceleration of Galactic cosmic rays. We then investigate the effects of the return flux of neutrals on the spectrum of test particles accelerated at the shock. We find that, for shocks slower than {approx}3000 km s{sup -1}, the particle energy spectrum steepens appreciably with respect to the naive expectation for a strong shock, namely, {proportional_to}E{sup -2}.

  2. Superconductivity of small particles

    International Nuclear Information System (INIS)

    Leavens, C.R.; Fenton, E.W.

    1981-01-01

    The Eliashberg gap equations are used to investigate the contribution of surface-phonon softening to the size dependence of the superconducting transition temperature (T/sub c/) of small metallic particles. Because of our limited quantitative knowledge of phonon spectra and electron-phonon coupling in the surface region, the effect cannot be calculated with certainty. Previous calculations which agree with experiment depend on a fortuitous choice of input parameters which cannot be justified at present. For this reason the absence of any observable size effect for T/sub c/ in Pb is especially important. This null effect is obtained in Pb if the electron-phonon coupling strength is the same in the surface region as in the bulk. This assumption can be tested experimentally because it means that the energy gap of Pb should not be independent of particle size but rather should increase significantly with decreasing radius. Hence, measurement of the size dependence of the energy gap for well-characterized small particles of Pb could provide information regarding the importance of the phonon-softening mechanism, at least for Pb

  3. Development of a pneumatic transfer system for HTGR recycle fuel particles

    International Nuclear Information System (INIS)

    Mack, J.E.; Johnson, D.R.

    1978-02-01

    In support of the High-Temperature Gas-Cooled Reactor (HTGR) Fuel Refabrication Development Program, an experimental pneumatic transfer system was constructed to determine the feasibility of pneumatically conveying pyrocarbon-coated fuel particles of Triso and Biso designs. Tests were conducted with these particles in each of their nonpyrophoric forms to determine pressure drops, particle velocities, and gas flow requirements during pneumatic transfer as well as to evaluate particle wear and breakage. Results indicated that the material can be pneumatically conveyed at low pressures without excessive damage to the particles or their coatings

  4. Particle Acceleration in a Statistically Modeled Solar Active-Region Corona

    Science.gov (United States)

    Toutounzi, A.; Vlahos, L.; Isliker, H.; Dimitropoulou, M.; Anastasiadis, A.; Georgoulis, M.

    2013-09-01

    Elaborating a statistical approach to describe the spatiotemporally intermittent electric field structures formed inside a flaring solar active region, we investigate the efficiency of such structures in accelerating charged particles (electrons). The large-scale magnetic configuration in the solar atmosphere responds to the strong turbulent flows that convey perturbations across the active region by initiating avalanche-type processes. The resulting unstable structures correspond to small-scale dissipation regions hosting strong electric fields. Previous research on particle acceleration in strongly turbulent plasmas provides a general framework for addressing such a problem. This framework combines various electromagnetic field configurations obtained by magnetohydrodynamical (MHD) or cellular automata (CA) simulations, or by employing a statistical description of the field's strength and configuration with test particle simulations. Our objective is to complement previous work done on the subject. As in previous efforts, a set of three probability distribution functions describes our ad-hoc electromagnetic field configurations. In addition, we work on data-driven 3D magnetic field extrapolations. A collisional relativistic test-particle simulation traces each particle's guiding center within these configurations. We also find that an interplay between different electron populations (thermal/non-thermal, ambient/injected) in our simulations may also address, via a re-acceleration mechanism, the so called `number problem'. Using the simulated particle-energy distributions at different heights of the cylinder we test our results against observations, in the framework of the collisional thick target model (CTTM) of solar hard X-ray (HXR) emission. The above work is supported by the Hellenic National Space Weather Research Network (HNSWRN) via the THALIS Programme.

  5. Effective particle magnetic moment of multi-core particles

    Energy Technology Data Exchange (ETDEWEB)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden); Wetterskog, Erik; Svedlindh, Peter [Department of Engineering Sciences, Uppsala University, Box 534, SE-751 21 Uppsala (Sweden); Lak, Aidin; Ludwig, Frank [Institute of Electrical Measurement and Fundamental Electrical Engineering, TU Braunschweig, D‐38106 Braunschweig Germany (Germany); IJzendoorn, Leo J. van [Department of Applied Physics, Eindhoven University of Technology, 5600 MB Eindhoven (Netherlands); Westphal, Fritz; Grüttner, Cordula [Micromod Partikeltechnologie GmbH, D ‐18119 Rostock (Germany); Gehrke, Nicole [nanoPET Pharma GmbH, D ‐10115 Berlin Germany (Germany); Gustafsson, Stefan; Olsson, Eva [Department of Applied Physics, Chalmers University of Technology, SE-412 96 Göteborg (Sweden); Johansson, Christer, E-mail: christer.johansson@acreo.se [Acreo Swedish ICT AB, Arvid Hedvalls backe 4, SE-411 33 Göteborg (Sweden)

    2015-04-15

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  6. Effective particle magnetic moment of multi-core particles

    International Nuclear Information System (INIS)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; IJzendoorn, Leo J. van; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-01-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems – BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm – and one single-core particle system – SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm

  7. Effective particle magnetic moment of multi-core particles

    Science.gov (United States)

    Ahrentorp, Fredrik; Astalan, Andrea; Blomgren, Jakob; Jonasson, Christian; Wetterskog, Erik; Svedlindh, Peter; Lak, Aidin; Ludwig, Frank; van IJzendoorn, Leo J.; Westphal, Fritz; Grüttner, Cordula; Gehrke, Nicole; Gustafsson, Stefan; Olsson, Eva; Johansson, Christer

    2015-04-01

    In this study we investigate the magnetic behavior of magnetic multi-core particles and the differences in the magnetic properties of multi-core and single-core nanoparticles and correlate the results with the nanostructure of the different particles as determined from transmission electron microscopy (TEM). We also investigate how the effective particle magnetic moment is coupled to the individual moments of the single-domain nanocrystals by using different measurement techniques: DC magnetometry, AC susceptometry, dynamic light scattering and TEM. We have studied two magnetic multi-core particle systems - BNF Starch from Micromod with a median particle diameter of 100 nm and FeraSpin R from nanoPET with a median particle diameter of 70 nm - and one single-core particle system - SHP25 from Ocean NanoTech with a median particle core diameter of 25 nm.

  8. Challenges associated with the behaviour of radioactive particles in the environment.

    Science.gov (United States)

    Salbu, Brit; Kashparov, Valery; Lind, Ole Christian; Garcia-Tenorio, Rafael; Johansen, Mathew P; Child, David P; Roos, Per; Sancho, Carlos

    2018-06-01

    A series of different nuclear sources associated with the nuclear weapon and fuel cycles have contributed to the release of radioactive particles to the environment. Following nuclear weapon tests, safety tests, conventional destruction of weapons, reactor explosions and fires, a major fraction of released refractory radionuclides such as uranium (U) and plutonium (Pu) were present as entities ranging from sub microns to fragments. Furthermore, radioactive particles and colloids have been released from reprocessing facilities and civil reactors, from radioactive waste dumped at sea, and from NORM sites. Thus, whenever refractory radionuclides are released to the environment following nuclear events, radioactive particles should be expected. Results from many years of research have shown that particle characteristics such as elemental composition depend on the source, while characteristics such as particle size distribution, structure, and oxidation state influencing ecosystem transfer depend also on the release scenarios. When radioactive particles are deposited in the environment, weathering processes occur and associated radionuclides are subsequently mobilized, changing the apparent K d . Thus, particles retained in soils or sediments are unevenly distributed, and dissolution of radionuclides from particles may be partial. For areas affected by particle contamination, the inventories can therefore be underestimated, and impact and risk assessments may suffer from unacceptable large uncertainties if radioactive particles are ignored. To integrate radioactive particles into environmental impact assessments, key challenges include the linking of particle characteristics to specific sources, to ecosystem transfer, and to uptake and retention in biological systems. To elucidate these issues, the EC-funded COMET and RATE projects and the IAEA Coordinated Research Program on particles have revisited selected contaminated sites and archive samples. This COMET position

  9. Nonlinear data assimilation using synchronization in a particle filter

    Science.gov (United States)

    Rodrigues-Pinheiro, Flavia; Van Leeuwen, Peter Jan

    2017-04-01

    Current data assimilation methods still face problems in strongly nonlinear cases. A promising solution is a particle filter, which provides a representation of the model probability density function by a discrete set of particles. However, the basic particle filter does not work in high-dimensional cases. The performance can be improved by considering the proposal density freedom. A potential choice of proposal density might come from the synchronisation theory, in which one tries to synchronise the model with the true evolution of a system using one-way coupling via the observations. In practice, an extra term is added to the model equations that damps growth of instabilities on the synchronisation manifold. When only part of the system is observed synchronization can be achieved via a time embedding, similar to smoothers in data assimilation. In this work, two new ideas are tested. First, ensemble-based time embedding, similar to an ensemble smoother or 4DEnsVar is used on each particle, avoiding the need for tangent-linear models and adjoint calculations. Tests were performed using Lorenz96 model for 20, 100 and 1000-dimension systems. Results show state-averaged synchronisation errors smaller than observation errors even in partly observed systems, suggesting that the scheme is a promising tool to steer model states to the truth. Next, we combine these efficient particles using an extension of the Implicit Equal-Weights Particle Filter, a particle filter that ensures equal weights for all particles, avoiding filter degeneracy by construction. Promising results will be shown on low- and high-dimensional Lorenz96 models, and the pros and cons of these new ideas will be discussed.

  10. Vibro-spring particle size distribution analyser

    International Nuclear Information System (INIS)

    Patel, Ketan Shantilal

    2002-01-01

    This thesis describes the design and development of an automated pre-production particle size distribution analyser for particles in the 20 - 2000 μm size range. This work is follow up to the vibro-spring particle sizer reported by Shaeri. In its most basic form, the instrument comprises a horizontally held closed coil helical spring that is partly filled with the test powder and sinusoidally vibrated in the transverse direction. Particle size distribution data are obtained by stretching the spring to known lengths and measuring the mass of the powder discharged from the spring's coils. The size of the particles on the other hand is determined from the spring 'intercoil' distance. The instrument developed by Shaeri had limited use due to its inability to measure sample mass directly. For the device reported here, modifications are made to the original configurations to establish means of direct sample mass measurement. The feasibility of techniques for measuring the mass of powder retained within the spring are investigated in detail. Initially, the measurement of mass is executed in-situ from the vibration characteristics based on the spring's first harmonic resonant frequency. This method is often erratic and unreliable due to the particle-particle-spring wall interactions and the spring bending. An much more successful alternative is found from a more complicated arrangement in which the spring forms part of a stiff cantilever system pivoted along its main axis. Here, the sample mass is determined in the 'static mode' by monitoring the cantilever beam's deflection following the wanton termination of vibration. The system performance has been optimised through the variations of the mechanical design of the key components and the operating procedure as well as taking into account the effect of changes in the ambient temperature on the system's response. The thesis also describes the design and development of the ancillary mechanisms. These include the pneumatic

  11. Electromagnetic deflection of spinning particles

    International Nuclear Information System (INIS)

    Costella, J.P.; McKellar, B.H.J.

    1992-01-01

    It is shown that it is possible to obtain self-consistent and physically acceptable relativistic classical equations of motion for a point-like spin-half particle possessing an electric charge and magnetic dipole moment, directly from a manifestly covariant Lagrangian, if the classical degrees of freedom are appropriately chosen. The equations obtained encompass the well-tested Lorentz force and Thomas-Bargmann-Michel-Telegdi spin equations, as well as providing a definite specification of the classical magnetic dipole force, whose exact form has been the subject of recent debate. Radiation reaction - the force and torque on an accelerated particle due to its self-interaction - is neglected at this stage. 18 refs

  12. Measurement quality assurance for beta particle calibrations at NIST

    Energy Technology Data Exchange (ETDEWEB)

    Soares, C.G.; Pruitt, J.S. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

    1993-12-31

    Standardized beta-particle fields have been established in an international standard and have been adopted for use in several U.S. dosimeter and instrument testing standards. Calibration methods and measurement quality assurance procedures employed at the National Institute of Standards and Technology (NIST) for beta-particle calibrations in these reference fields are discussed. The calibration facility including the NIST-automated extrapolation ionization chamber is described, and some sample results of calibrations are shown. Methods for establishing and maintaining traceability to NIST of secondary laboratories are discussed. Currently, there are problems in finding a good method for routine testing of traceability to NIST. Some examples of past testing methods are given and solutions to this problem are proposed.

  13. Measurement quality assurance for beta particle calibrations at NIST

    International Nuclear Information System (INIS)

    Soares, C.G.; Pruitt, J.S.

    1993-01-01

    Standardized beta-particle fields have been established in an international standard and have been adopted for use in several U.S. dosimeter and instrument testing standards. Calibration methods and measurement quality assurance procedures employed at the National Institute of Standards and Technology (NIST) for beta-particle calibrations in these reference fields are discussed. The calibration facility including the NIST-automated extrapolation ionization chamber is described, and some sample results of calibrations are shown. Methods for establishing and maintaining traceability to NIST of secondary laboratories are discussed. Currently, there are problems in finding a good method for routine testing of traceability to NIST. Some examples of past testing methods are given and solutions to this problem are proposed

  14. Four-particle scattering with three-particle interactions

    International Nuclear Information System (INIS)

    Adhikari, S.K.

    1979-01-01

    The four-particle scattering formalism proposed independently by Alessandrini, by Mitra et al., by Rosenberg, and by Takahashi and Mishima is extended to include a possible three-particle interaction. The kernel of the new equations we get contain both two- and three-body connected parts and gets four-body connected after one iteration. On the other hand, the kernel of the original equations in the absence of three-particle interactions does not have a two-body connected part. We also write scattering equations for the transition operators connecting the two-body fragmentation channels. They are generalization of the Sloan equations in the presence of three-particle interactions. We indicate how to include approximately the effect of a weak three-particle interaction in a practical four-particle scattering calculation

  15. From dressed particle to dressed mode in plasmas

    Energy Technology Data Exchange (ETDEWEB)

    Itoh, Sanae-I. [Kyushu Univ., Research Inst. for Applied Mechanics, Kasuga, Fukuoka (Japan); Itoh, Kimitaka [National Inst. for Fusion Science, Toki, Gifu (Japan)

    2002-05-01

    A theoretical method to analyze the strong turbulence in far-nonequilibrium plasma is discussed. In this approach, a test mode is treated being dressed with interactions with other modes. Nonlinear dispersion relation of the dressed mode and statistical treatment of turbulence is briefly explained. Analogue to the method of dressed particle, which has given Balescu-Lenard collision operator for inter-particle collisions, is mentioned. (author)

  16. Single-particle potential from resummed ladder diagrams

    International Nuclear Information System (INIS)

    Kaiser, N.

    2013-01-01

    A recent work on the resummation of fermionic in-medium ladder diagrams to all orders is extended by calculating the complex single-particle potential U(p, k f ) + i W(p, k f ) p > k f . The on-shell single-particle potential is constructed by means of a complex-valued in-medium loop that includes corrections from a test particle of momentum vector p added to the filled Fermi sea. The single-particle potential U(k f , k f ) at the Fermi surface as obtained from the resummation of the combined particle and hole ladder diagrams is shown to satisfy the Hugenholtz-Van-Hove theorem. The perturbative contributions at various orders a n in the scattering length are deduced and checked against the known analytical results at order a 1 and a 2 . The limit a → ∞ is studied as a special case and a strong momentum dependence of the real (and imaginary) single-particle potential is found. This feature indicates an instability against a phase transition to a state with an empty shell inside the Fermi sphere such that the density gets reduced by about 5%. The imaginary single-particle potential vanishes linearly at the Fermi surface. For comparison, the same analysis is performed for the resummed particle-particle ladder diagrams alone. In this truncation an instability for hole excitations near the Fermi surface is found at strong coupling. For the set of particle-hole ring diagrams the single-particle potential is calculated as well. Furthermore, the resummation of in-medium ladder diagrams to all orders is studied for a two-dimensional Fermi gas with a short-range two-body contact interaction. (orig.)

  17. Review of intermediate and final product characterization on coated particles preparation

    International Nuclear Information System (INIS)

    Sukarsono; Kristanti Nurwidyaningrum

    2015-01-01

    Review of the intermediate and final product characterization on preparation of coated particles was done. Product characterization included a tool to measure the character of raw materials, intermediate product and the final product of the process, which affects the success of getting the high temperature reactor fuel are eligible. Equipment's for the characterization of such materials were pH meter, viscometer, microbalance, turbidity meter, tab density measurement, true density measurement and auto pycnometer. Being for the measurement of particles there are two types destructive testing and non destructive. Destructive testing was done by polished the particles then cross sectional imaging of particle observed using an optical microscope. In this way contains errors due to polishing treatment that could not be right on the equator section so it needs correction. Destructive testing also create waste that must be processed from the remnants of the polishing process. By using non-destructive testing, waste was not formed but the imaging results are often unclear due to lack of contrast. Development of non-destructive test equipment has been made using radiographic method and automated microscopy. The overall activity is still much needed additional tools for measurement and for processing, so that the results obtained will not rejected as the specification of nuclear fuel. Similarly, in the case of a sampling test method and limits to a product accepted or rejected, it should be determined based on statistical methods. (author)

  18. Overview of particle physics

    International Nuclear Information System (INIS)

    Salam, A.

    1986-02-01

    An overview of the situation of particle physics at the end of 1985 is given. It includes the following topics: ideas which have been tested or will soon be tested such as the standard model based on the symmetry group SUsub(C)(3)xSUsub(L)(2)xU(1), light Higgs and preons; theoretical ideas whose time has not yet come (basically because no accelerators are being constructed to test them) such as N=1 supersymmetry and N=1 supergravity right-handed weak currents, extended supergravities and superstring models; ideas for which non-accelerator and passive experiments have been mounted such as proton decay, nn-bar oscillations, neutrino masses and oscillations, monopoles and dark matter

  19. Polymer degradation and ultrafine particles - Potential inhalation hazards for astronauts

    Science.gov (United States)

    Ferin, J.; Oberdoerster, G.

    1992-01-01

    To test the hypothesis that exposure to ultrafine particles results in an increased interstiatilization of the particles which is accompanied by an acute pathological inflammation, rats were exposed to titanium dioxide (TiO2) particles by intratracheal instillation and by inhalation. Both acute intratracheal instillation and subchronic inhalation studies on rats show that ultrafine TiO2 particles access the pulmonary interstitium to a larger extent than fine particles and that they elicit an inflammatory response as indicated by PMN increase in lavaged cells. The release of ultrafine particles into the air of an enclosed environment from a thermodegradation event or from other sources is a potential hazard for astronauts. Knowing the mechanisms of action is a prerequisite for technical or medical countermeasures.

  20. Late time CMB anisotropies constrain mini-charged particles

    Energy Technology Data Exchange (ETDEWEB)

    Burrage, C.; Redondo, J.; Ringwald, A. [Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany); Jaeckel, J. [Univ. of Durham, Inst. for Particle Physics Phenomenology (United Kingdom)

    2009-09-15

    Observations of the temperature anisotropies induced as light from the CMB passes through large scale structures in the late universe are a sensitive probe of the interactions of photons in such environments. In extensions of the Standard Model which give rise to mini-charged particles, photons propagating through transverse magnetic fields can be lost to pair production of such particles. Such a decrement in the photon flux would occur as photons from the CMB traverse the magnetic fields of galaxy clusters. Therefore late time CMB anisotropies can be used to constrain the properties of mini- charged particles. We outline how this test is constructed, and present new constraints on mini-charged particles from observations of the Sunyaev-Zel'dovich effect in the Coma cluster. (orig.)

  1. Three-particle correlations in QCD parton showers

    International Nuclear Information System (INIS)

    Perez-Ramos, Redamy; Mathieu, Vincent; Sanchis-Lozano, Miguel-Angel

    2011-01-01

    Three-particle correlations in quark and gluon jets are computed for the first time in perturbative QCD. We give results in the double logarithmic approximation and the modified leading logarithmic approximation. In both resummation schemes, we use the formalism of the generating functional and solve the evolution equations analytically from the steepest descent evaluation of the one-particle distribution. We thus provide a further test of the local parton hadron duality and make predictions for the LHC.

  2. Perturbative Universality in Soft Particle Production

    CERN Document Server

    Khoze, V A; Ochs, Wolfgang; Khoze, Valery A.; Lupia, Sergio; Ochs, Wolfgang

    1998-01-01

    The spectrum of partons in a QCD jet becomes independent of the primary energy in the low momentum limit. This follows within the perturbative QCD from the colour coherence in soft gluon branching. Remarkably, the hadrons follow such behaviour closely, suggesting the parton hadron duality picture to be appropriate also for the low momentum particles. More generally, this scaling property holds for particles of low transverse and arbitrary longitudinal momentum, which explains an old experimental observation (``fan invariance''). Further tests of the perturbatively based picture for soft particle production are proposed for three-jet events in e+e- annihilation and di-jet production events in gamma p, gamma-gamma and p\\bar p collisions. They are based upon the difference in the intensity of the soft radiation from primary q\\bar q and gg antennae.

  3. Preliminary test of the MONDO project secondary fast and ultrafast neutrons tracker response using protons and MIP particles

    Science.gov (United States)

    Traini, G.; Battistoni, G.; Giacometti, V.; Gioscio, E.; Marafini, M.; Mirabelli, R.; Pinci, D.; Sarti, A.; Sciubba, A.; Patera, V.

    2018-04-01

    The risk of developing a second malignant cancer as a late time consequence of undergoing a treatment, is one of the main concerns in particle therapy (PT). Since neutrons can release a significant dose far away from the tumour region, a precise characterisation of their production point, kinetic energy and abundance is eagerly needed. The treatment planning system (TPS) software that predicts the normal tissue toxicity in the target region and the risk of late complications in the whole body is currently based on the poorly known production cross-sections and will greatly benefit from improved precision double differential measurements. The MONDO (MOnitor for Neutron Dose in hadrOntherapy) project aims to build an ultrafast neutron tracker that could be used to characterise the production of secondary neutrons with energies in the 20–400 MeV range. The neutron tracking will proceed via the detection of recoil protons produced in two consecutive (n, p) elastic scattering interactions. The MONDO detector consists of a 10 × 10 × 20 cm3 matrix of thin scintillating fibres, arranged in orthogonally oriented layers. A compact read-out sensor with single photon detection capabilities employing the CMOS SPAD technology has been developed in collaboration with Fondazione Bruno Kessler (FBK). The detector will be completed by the end of 2018. A 4 × 4 × 4.8 cm3 prototype has been built using 250 μ m thick scintillating fibres of squared section and was tested using a proton beam and minimum ionising particles. In this contribution we present the experimental results related to the prototype test performed with a proton beam at the Proton Therapy Centre of the Trento Hospital (PTC) in May 2017. The results are compared with the results of a Monte Carlo simulation performed with the FLUKA software.

  4. Comparison of testing methods for particulate filters

    International Nuclear Information System (INIS)

    Ullmann, W.; Przyborowski, S.

    1983-01-01

    Four testing methods for particulate filters were compared by using the test rigs of the National Board of Nuclear Safety and Radiation Protection: 1) Measurement of filter penetration P as a function of particle size d by using a polydisperse NaC1 test aerosol and a scintillation particle counter; 2) Modified sodium flame test for measurement of total filter penetration P for various polydisperse NaC1 test aerosols; 3) Measurement of total filter penetration P for a polydisperse NaC1 test aerosol labelled with short-lived radon daughter products; 4) Measurement of total filter penetration P for a special paraffin oil test aerosol (oil fog test used in FRG according DIN 24 184, test aerosol A). The investigations were carried out on sheets of glass fibre paper (five grades of paper). Detailed information about the four testing methods and the used particle size distributions is given. The different results of the various methods are the base for the discussion of the most important parameters which influence the filter penetration P. The course of the function P=f(d) shows the great influence of the particle size. As expected there was also found a great dependence both from the test aerosol as well as from the principle and the measuring range of the aerosol-measuring device. The differences between the results of the various test methods are greater the lower the penetration. The use of NaCl test aerosol with various particle size distributions gives great differences for the respective penetration values. On the basis of these results and the values given by Dorman conclusions are made about the investigation of particulate filters both for the determination of filter penetration P as well as for the leak test of installed filters

  5. Taking aim : particle impact drilling targets ROP gains

    Energy Technology Data Exchange (ETDEWEB)

    Mahoney, J.

    2005-11-01

    Details of a new drilling technique developed by Particle Drilling Technologies Inc. were presented. Particle impact drilling uses buckshot-like steel particles entrained with ordinary drilling mud that are accelerated through a specially-designed drill bit to bombard hard-rock formations at rapid-fire velocities of up to 4 million times a minute. Conventional drill bits rely on mechanical energy from some 50,000 pounds of weight on bit and torque to break or fracture the formation, whereas particle impact drilling relies on hydraulic energy to blast the steel particles from the bit's jetting nozzles in order to repeatedly fracture the formation. It was suggested that the new technology will accelerate the drilling process. Tests have shown that the new device out-performs conventional bits in hard formations by utilizing the hydraulics of the rig to drill with particles. In field tests, drilling was 4 times faster than conventional methods. It was anticipated that the bit will be up to 150 per cent faster in softer rock formations. In order to avoid clogging, the system uses a shot trap to remove the steel balls, which are roughly one-tenth of an inch in diameter, from the drilling fluid before it enters the shale shaker. The shot is recycled after each well. During drilling, mud circulation must be continuous for the system to work. If the system can't circulate cleanly out of a hole, there is a disruption in the process and drilling fluid may move up the annulus at 350 feet per minute when it leaves bottomhole. It was suggested that circulation issues can be resolved by increasing mud viscosity. A less than optimal performance during a recent test at Catoosa was attributed to a lack of control over drilling fluid parameters and to the use of an overly-large well casing. It was concluded that the new system will likely greatly reduce the number of days it takes to drill a well. 2 figs.

  6. Fission Product Release Behavior of Individual Coated Fuel Particles for High-Temperature Gas-Cooled Reactors

    International Nuclear Information System (INIS)

    Minato, Kazuo; Sawa, Kazuhiro; Koya, Toshio; Tomita, Takeshi; Ishikawa, Akiyoshi; Baldwin, Charles A.; Gabbard, William Alexander; Malone, Charlie M.

    2000-01-01

    Postirradiation heating tests of TRISO-coated UO 2 particles at 1700 and 1800degC were performed to understand fission product release behavior at accident temperatures. The inventory measurements of the individual particles were carried out before and after the heating tests with gamma-ray spectrometry to study the behavior of the individual particles. The time-dependent release behavior of 85 Kr, 110m Ag, 134 Cs, 137 Cs, and 154 Eu were obtained with on-line measurements of fission gas release and intermittent measurements of metallic fission product release during the heating tests. The inventory measurements of the individual particles revealed that fission product release behavior of the individual particles was not uniform, and large particle-to-particle variations in the release behavior of 110m Ag, 134 Cs, 137 Cs, and 154 Eu were found. X-ray microradiography and ceramography showed that the variations could not be explained by only the presence or absence of cracks in the SiC coating layer. The SiC degradation may have been related to the variations

  7. Dynamics of neutral and charged aerosol particles

    Energy Technology Data Exchange (ETDEWEB)

    Leppae, J.

    2012-07-01

    Atmospheric aerosol particles have various climate effects and adverse health effects, which both depend on the size and number concentration of the particles. Freshly-formed particles are not large enough to impact neither health nor climate and they are most susceptible to removal by collisions with larger pre-existing particles. Consequently, the knowledge of both the formation and the growth rate of particles are crucially important when assessing the health and climate effects of atmospheric new particle formation. The purpose of this thesis is to increase our knowledge of the dynamics of neutral and charged aerosol particles with a specific interest towards the particle growth rate and processes affecting the aerosol charging state. A new model, Ion-UHMA, which simulates the dynamics of neutral and charged particles, was developed for this purpose. Simple analytical formulae that can be used to estimate the growth rate due to various processes were derived and used to study the effects of charged particles on the growth rate. It was found that the growth rate of a freshly-formed particle population due to condensation and coagulation could be significantly increased when a considerable fraction of the particles are charged. Finally, recent data-analysis methods that have been applied to the aerosol charging states obtained from the measurements were modified for a charge asymmetric framework. The methods were then tested on data obtained from aerosol dynamics simulations. The methods were found to be able to provide reasonable estimates on the growth rate and proportion of particles formed via ion-induced nucleation, provided that the growth rate is high enough and that the charged particles do not grow much more rapidly than the neutral ones. A simple procedure for estimating whether the methods are suitable for analysing data obtained in specific conditions was provided. In this thesis, the dynamics of neutral and charged aerosol particles were studied in

  8. Study of the Parametric Performance of Solid Particle Erosion Wear under the Slurry Pot Test Rig

    Directory of Open Access Journals (Sweden)

    S.R. More

    2017-12-01

    Full Text Available Stainless Steel (SS 304 is commonly used material for slurry handling applications like pipelines, valves, pumps and other equipment's. Slurry erosion wear is a common problem in many engineering applications like process industry, thermal and hydraulic power plants and slurry handling equipments. In this paper, experimental investigation of the influence of solid particle size, impact velocity, impact angle and solid concentration parameters in slurry erosion wear behavior of SS 304 using slurry pot test rig. In this study the design of experiments was considered using Taguchi technique. A comparison has been made for the experimental and Taguchi technique results. The erosion wear morphology was studied using micro-graph obtained by scanning electron microscope (SEM analysis. At shallow impact angle 30°, the material removal pattern was observed in the form of micro displacing, scratching and ploughing with plastic deformation of the material. At 60° impact angle, mixed type of micro indentations and pitting action is observed. At normal impact angle 90°, the material removal pattern was observed in form of indentation and rounded lips. It is found that particle velocity was the most influence factor than impact angle, size and solid concentration. From this investigation, it can be concluded that the slurry erosion wear is minimized by controlling the slurry flow velocity which improves the service life of the slurry handling equipments. From the comparison of experimental and Taguchi experimental design results it is found that the percentage deviation was very small with a higher correlation coefficient (r2 0.987 which is agreeable.

  9. 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.

  10. Big Bang Day: 5 Particles - 5. The Next Particle

    CERN Multimedia

    Franck Close

    2008-01-01

    Simon Singh looks at the stories behind the discovery of 5 of the universe's most significant subatomic particles: the Electron, the Quark, the Anti-particle, the Neutrino and the "next particle". 5. The Next Particle The "sparticle" - a super symmetric partner to all the known particles could be the answer to uniting all the known particles and their interactions under one grand theoretical pattern of activity. But how do researchers know where to look for such phenomena and how do they know if they find them? Simon Singh reviews the next particle that physicists would like to find if the current particle theories are to ring true.

  11. Comparative In Vitro Biological Toxicity of Four Kinds of Air Pollution Particles.

    Science.gov (United States)

    Shin, Han-Jae; Cho, Hyun Gi; Park, Chang Kyun; Park, Ki Hong; Lim, Heung Bin

    2017-10-01

    Accumulating epidemiological evidence indicates that exposure to fine air pollution particles (APPs) is associated with a variety of adverse health effects. However, the exact physiochemical properties and biological toxicities of fine APPs are still not well characterized. We collected four types of fine particle (FP) (diesel exhaust particles [DEPs], natural organic combustion [NOC] ash, synthetic organic combustion [SOC] ash, and yellow sand dust [YSD]) and investigated their physicochemical properties and in vitro biological toxicity. DEPs were almost entirely composed of ultrafine particles (UFPs), while the NOC, SOC, and YSD particles were a mixture of UFPs and FPs. The main elements in the DEPs, NOC ash, SOC ash, and YSD were black carbon, silicon, black carbon, and silicon, respectively. DEPs exhibited dose-dependent mutagenicity even at a low dose in Salmonella typhimurium TA 98 and 100 strains in an Ames test for genotoxicity. However, NOC, SOC, and YSD particles did not show any mutagenicity at high doses. The neutral red uptake assay to test cell viability revealed that DEPs showed dose-dependent potent cytotoxicity even at a low concentration. The toxicity of DEPs was relatively higher than that of NOC, SOC, and YSD particles. Therefore, these results indicate that among the four FPs, DEPs showed the highest in vitro biological toxicity. Additional comprehensive research studies such as chemical analysis and in vivo acute and chronic inhalation toxicity tests are necessary to determine and clarify the effects of this air contaminant on human health.

  12. 49 CFR 178.337-16 - Testing.

    Science.gov (United States)

    2010-10-01

    ... subjected, after postweld heat treatment and hydrostatic tests, to a wet fluorescent magnetic particle... shell and heads both inside and outside by either the wet fluorescent magnetic particle method... to perform the magnetic particle inspection. (c) All defects found shall be repaired, the cargo tanks...

  13. Classical relativistic constituent particles and composite-particle scattering

    International Nuclear Information System (INIS)

    King, M.J.

    1984-01-01

    A nonlocal Lagrangian formalism is developed to describe a classical many-particle system. The nonstandard Lagrangian is a function of a single parameter s which is not, in general, associated with the physical clock. The particles are constrained to be constituents of composite systems, which in turn can decompose into asymptotic composite states representing free observable particles. To demonstrate this, explicit models of composite-composite particle scattering are constructed. Space-time conservation laws are not imposed separately on the system, but follow upon requiring the constituents to ''pair up'' into free composites at s = +infinity,-infinity. One model is characterized by the appearance of an ''external'' zero-mass composite particle which participates in the scattering process without affecting the space-time conservation laws of the two-composite system. Initial conditions on the two incoming composite particles and the zero-mass participant determine the scattering angle and the final states of the two outgoing composite particles. Although the formalism is classical, the model displays some features usually associated with quantum field theory, such as particle scattering by means of constituent exchange, creation and annihilation of particles, and restriction of values of angular momentum

  14. An In-situ materials analysis particle probe (MAPP) diagnostic to study particle density control and hydrogenic fuel retention in NSTX

    Energy Technology Data Exchange (ETDEWEB)

    Allain, Jean-Paul [Purdue Univ., West Lafayette, IN (United States)

    2014-09-05

    A new materials analysis particle probe (MAPP) was designed, constructed and tested to develop understanding of particle control and hydrogenic fuel retention in lithium-based plasma-facing surfaces in NSTX. The novel feature of MAPP is an in-situ tool to probe the divertor NSTX floor during LLD and lithium-coating shots with subsequent transport to a post-exposure in-vacuo surface analysis chamber to measure D retention. In addition, the implications of a lithiated graphite-dominated plasma-surface environment in NSTX on LLD performance, operation and ultimately hydrogenic pumping and particle control capability are investigated in this proposal. MAPP will be an invaluable tool for erosion/redeposition simulation code validation.

  15. Ash particle erosion on steam boiler convective section

    Energy Technology Data Exchange (ETDEWEB)

    Meuronen, V

    1998-12-31

    In this study, equations for the calculation of erosion wear caused by ash particles on convective heat exchanger tubes of steam boilers are presented. A new, three-dimensional test arrangement was used in the testing of the erosion wear of convective heat exchanger tubes of steam boilers. When using the sleeve-method, three different tube materials and three tube constructions could be tested. New results were obtained from the analyses. The main mechanisms of erosion wear phenomena and erosion wear as a function of collision conditions and material properties have been studied. Properties of fossil fuels have also been presented. When burning solid fuels, such as pulverized coal and peat in steam boilers, most of the ash is entrained by the flue gas in the furnace. In bubbling and circulating fluidized bed boilers, particle concentration in the flue gas is high because of bed material entrained in the flue gas. Hard particles, such as sharp edged quartz crystals, cause erosion wear when colliding on convective heat exchanger tubes and on the rear wall of the steam boiler. The most important ways to reduce erosion wear in steam boilers is to keep the velocity of the flue gas moderate and prevent channelling of the ash flow in a certain part of the cross section of the flue gas channel, especially near the back wall. One can do this by constructing the boiler with the following components. Screen plates can be used to make the velocity and ash flow distributions more even at the cross-section of the channel. Shield plates and plate type constructions in superheaters can also be used. Erosion testing was conducted with three types of tube constructions: a one tube row, an in- line tube bank with six tube rows, and a staggered tube bark with six tube rows. Three flow velocities and two particle concentrations were used in the tests, which were carried out at room temperature. Three particle materials were used: quartz, coal ash and peat ash particles. Mass loss

  16. ORNL facilities for testing first-wall components

    International Nuclear Information System (INIS)

    Tsai, C.C.; Becraft, W.R.; Gardner, W.L.; Haselton, H.H.; Hoffman, D.J.; Menon, M.M.; Stirling, W.L.

    1985-01-01

    Future long-impulse magnetic fusion devices will have operating characteristics similar to those described in the design studies of the Tokamak Fusion Core Experiment (TFCX), the Fusion Engineering Device (FED), and the International Tokamak Reactor (INTOR). Their first-wall components (pumped limiters, divertor plates, and rf waveguide launchers with Faraday shields) will be subjected to intense bombardment by energetic particles exhausted from the plasma, including fusion products. These particles are expected to have particle energies of approx.100 eV, particle fluxes of approx.10 18 cm -2 .s -1 , and heat fluxes of approx.1 kW/cm 2 CW to approx.100 kW/cm 2 transient. No components are available to simultaneously handle these particle and heat fluxes, survive the resulting sputtering erosion, and remove exhaust gas without degrading plasma quality. Critical issues for research and development of first-wall components have been identified in the INTOR Activity. Test facilities are needed to qualify candidate materials and develop components. At Oak Ridge National Laboratory (ORNL), existing neutral beam and wave heating test facilities can be modified to simulate first-wall environments with heat fluxes up to 30 kW/cm 2 , particle fluxes of approx.10 18 cm -2 .s -1 , and pulse lengths up to 30 s, within test volumes up to approx.100 L. The characteristics of these test facilities are described, with particular attention to the areas of particle flux, heat flux, particle energy, pulse length, and duty cycle, and the potential applications of these facilities for first-wall component development are discussed

  17. [Size distribution of particle and polycyclic aromatic hydrocarbons in particle emissions from simulated emission sources].

    Science.gov (United States)

    Fu, Hai-Huan; Tian, Na; Shang, Hui-Bin; Zhang, Bin; Ye, Su-Fen; Chen, Xiao-Qiu; Wu, Shui-Ping

    2014-01-01

    Particles from cooking lampblack, biomass and plastics burning smoke, gasoline vehicular exhausts and gasoline generator exhausts were prepared in a resuspension test chamber and collected using a cascade MOUDI impactor. A total of 18 polycyclic aromatic hydrocarbons (PAHs) associated with particles were analyzed by GC-MS. The results showed that there were two peaks in the range of 0.44-1.0 microm and 2.5-10 microm for cooking lampblack, and only one peak in the range of 0.44-1.0 microm for straw and wood burning smoke. But there were no clear peak for plastics burning smoke. The peak for gasoline vehicular exhausts was found in the range of 2.5-10 microm due to the influence of water vapor associated with particles, while the particles from gasoline generator exhausts were mainly in the range of lampblack and gasoline vehicular exhausts. The peak in the range of 0.44-1.0 microm became more and more apparent with the increase of PAHs molecular weight. The fraction of PAH on particles less than 1.0 microm to that on the total particles increased along with PAH's molecular weight. Phenanthrene was the dominant compound for cooking lampblack and combustion smoke, while gasoline vehicular exhausts and generator exhausts were characterized with significantly high levels of naphthalene and benzo[g, h, i] perylene, respectively. The distribution of source characteristic ratios indicated that PAHs from cooking lampblack and biomass burning were close and they were different from those of vehicular exhausts and generator exhausts.

  18. Bio-inspired particle separator design based on the food retention mechanism by suspension-feeding fish

    International Nuclear Information System (INIS)

    Hung, Tien-Chieh; Piedrahita, Raul H; Cheer, Angela

    2012-01-01

    A new particle separator is designed using a crossflow filtration mechanism inspired by suspension-feeding fish in this study. To construct the model of the bio-inspired particle separator, computational fluid dynamics techniques are used, and parameters related to separator shape, fluid flow and particle properties that might affect the performance in removing particles from the flow, are varied and tested. The goal is to induce a flow rotation which enhances the separation of particles from the flow, reduce the particle-laden flow that exits via a collection zone at the lower/posterior end of the separator, while at the same time increase the concentration of particles in that flow. Based on preliminary particle removal efficiency tests, an exiting flow through the collection zone of about 8% of the influent flow rate is selected for all the performance tests of the separator including trials with particles carried by air flow instead of water. Under this condition, the simulation results yield similar particle removal efficiencies in water and air but with different particle properties. Particle removal efficiencies (percentage of influent particles that exit through the collection zone) were determined for particles ranging in size from 1 to 1500 µm with a density between 1000 and 1150 kg m −3 in water and 2 and 19 mm and 68 and 2150 kg m −3 in air. As an example, removal efficiencies are 66% and 64% for 707 µm diameter particles with a density of 1040 kg m −3 in water and for 2 mm particles with a density of 68 kg m −3 in air, respectively. No significant performance difference is found by geometrically scaling the inlet diameter of the separator up or down in the range from 2.5 to 10 cm. (paper)

  19. Particle phase distribution of polycyclic aromatic hydrocarbons in stormwater — Using humic acid and iron nano-sized colloids as test particles

    DEFF Research Database (Denmark)

    Nielsen, Katrine; Kalmykova, Yuliya; Strömvall, Ann-Margret

    2015-01-01

    The distribution of polycyclic aromatic hydrocarbons (PAHs) in different particulate fractions in stormwater: Total, Particulate, Filtrated, Colloidal and Dissolved fractions, were examined and compared to synthetic suspensions of humic acid colloids and iron nano-sized particles. The distribution...

  20. A Novel Particle Swarm Optimization Algorithm for Global Optimization.

    Science.gov (United States)

    Wang, Chun-Feng; Liu, Kui

    2016-01-01

    Particle Swarm Optimization (PSO) is a recently developed optimization method, which has attracted interest of researchers in various areas due to its simplicity and effectiveness, and many variants have been proposed. In this paper, a novel Particle Swarm Optimization algorithm is presented, in which the information of the best neighbor of each particle and the best particle of the entire population in the current iteration is considered. Meanwhile, to avoid premature, an abandoned mechanism is used. Furthermore, for improving the global convergence speed of our algorithm, a chaotic search is adopted in the best solution of the current iteration. To verify the performance of our algorithm, standard test functions have been employed. The experimental results show that the algorithm is much more robust and efficient than some existing Particle Swarm Optimization algorithms.

  1. Detecting charging state of ultra-fine particles: instrumental development and ambient measurements

    Directory of Open Access Journals (Sweden)

    L. Laakso

    2007-01-01

    Full Text Available The importance of ion-induced nucleation in the lower atmosphere has been discussed for a long time. In this article we describe a new instrumental setup – Ion-DMPS – which can be used to detect contribution of ion-induced nucleation on atmospheric new particle formation events. The device measures positively and negatively charged particles with and without a bipolar charger. The ratio between "charger off" to "charger on" describes the charging state of aerosol particle population with respect to equilibrium. Values above one represent more charges than in an equilibrium (overcharged state, and values below unity stand for undercharged situation, when there is less charges in the particles than in the equilibrium. We performed several laboratory experiments to test the operation of the instrument. After the laboratory tests, we used the device to observe particle size distributions during atmospheric new particle formation in a boreal forest. We found that some of the events were clearly dominated by neutral nucleation but in some cases also ion-induced nucleation contributed to the new particle formation. We also found that negative and positive ions (charged particles behaved in a different manner, days with negative overcharging were more frequent than days with positive overcharging.

  2. Source contributions to atmospheric fine carbon particle concentrations

    Science.gov (United States)

    Andrew Gray, H.; Cass, Glen R.

    A Lagrangian particle-in-cell air quality model has been developed that facilitates the study of source contributions to atmospheric fine elemental carbon and fine primary total carbon particle concentrations. Model performance was tested using spatially and temporally resolved emissions and air quality data gathered for this purpose in the Los Angeles area for the year 1982. It was shown that black elemental carbon (EC) particle concentrations in that city were dominated by emissions from diesel engines including both on-highway and off-highway applications. Fine primary total carbon particle concentrations (TC=EC+organic carbon) resulted from the accumulation of small increments from a great variety of emission source types including both gasoline and diesel powered highway vehicles, stationary source fuel oil and gas combustion, industrial processes, paved road dust, fireplaces, cigarettes and food cooking (e.g. charbroilers). Strategies for black elemental carbon particle concentration control will of necessity need to focus on diesel engines, while controls directed at total carbon particle concentrations will have to be diversified over a great many source types.

  3. Interaction of Multiple Particles with a Solidification Front: From Compacted Particle Layer to Particle Trapping.

    Science.gov (United States)

    Saint-Michel, Brice; Georgelin, Marc; Deville, Sylvain; Pocheau, Alain

    2017-06-13

    The interaction of solidification fronts with objects such as particles, droplets, cells, or bubbles is a phenomenon with many natural and technological occurrences. For an object facing the front, it may yield various fates, from trapping to rejection, with large implications regarding the solidification pattern. However, whereas most situations involve multiple particles interacting with each other and the front, attention has focused almost exclusively on the interaction of a single, isolated object with the front. Here we address experimentally the interaction of multiple particles with a solidification front by performing solidification experiments of a monodisperse particle suspension in a Hele-Shaw cell with precise control of growth conditions and real-time visualization. We evidence the growth of a particle layer ahead of the front at a close-packing volume fraction, and we document its steady-state value at various solidification velocities. We then extend single-particle models to the situation of multiple particles by taking into account the additional force induced on an entering particle by viscous friction in the compacted particle layer. By a force balance model this provides an indirect measure of the repelling mean thermomolecular pressure over a particle entering the front. The presence of multiple particles is found to increase it following a reduction of the thickness of the thin liquid film that separates particles and front. We anticipate the findings reported here to provide a relevant basis to understand many complex solidification situations in geophysics, engineering, biology, or food engineering, where multiple objects interact with the front and control the resulting solidification patterns.

  4. Particle film affects black pecan aphid (Homoptera: Aphididae) on pecan.

    Science.gov (United States)

    Cottrell, Ted E; Wood, Bruce W; Reilly, Charles C

    2002-08-01

    Three species of aphids attack pecan foliage, Carya illinoensis (Wang.) K. Koch, and cause economic damage. We tested a kaolin-based particle film against one of these aphid species, black pecan aphid, Melanocallis caryaefoliae (Davis). Effect of particle film on host selection, adult mortality, and production of nymphs by M. caryaefoliae was tested on seedling pecans in the laboratory. Fewer M. caryaefoliae adults selected treated foliage compared with untreated foliage. A higher percentage of adults that did select treated foliage were recovered from upper leaf surfaces compared with the percentage of adults recovered from upper leaf surfaces of untreated leaves. Observations with a microscope revealed an accumulation of particle film on aphid body parts, especially on tarsi, and strongly suggests that aphid mobility was restricted. Adult mortality was higher on treated foliage and led to an overall decrease in production of nymphs on those seedlings. In addition, we measured spectral properties of treated seedling pecan foliage. Light reflectance by treated foliage was increased and absorptance decreased compared with control foliage whereas transmittance of light through control and particle film-treated leaves was similar. We did not detect any phytotoxic effect on pecan due to application of particle film.

  5. Nearly finished LHC particle smasher breaks at support point to magnets

    CERN Multimedia

    Atkins, William

    2007-01-01

    "The proton-proton Large Hadron Collider (LHC) particle accelerator is being built at Geneva, Switzerland's CERN - the world's largest particle physics laboratory. However, a support assembly structure for critical magnets failed while being tested on March 27, 2007." (1/2 page)

  6. Constraints on particle physics from cosmology

    International Nuclear Information System (INIS)

    Schramm, D.N.; Charlton, J.C.

    1986-01-01

    Cosmology and particle physics have become symbiotic in their relationship. In the past, developments in physics have been used to explain astrophysics problems. Recently, cosmology also has been able to place constraints on particle properties and these constraints can be tested by experiment. Thus, the flow of information at the interface of particle physics and cosmology is no longer just one-way. (Astronomy is no longer a parasite of physics.) Many examples of the interchange are described in this review. The timeline of cosmology is rapidly filling in as later events find their explanations in earlier events. In this review, the authors mention what is known about each epoch and show how it might constrain the particle models. Since a great deal of effort is devoted currently to the study of the dark matter problem, special emphasis will be placed on this issue. This study of dark matter and galaxy formation will allow us to draw upon much of what was discussed in earlier epochs. This review draws heavily on a previous review by the authors

  7. Studies of Fundamental Particle Dynamics in Microgravity

    Science.gov (United States)

    Rangel, Roger; Trolinger, James D.; Coimbra, Carlos F. M.; Witherow, William; Rogers, Jan; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    This work summarizes theoretical and experimental concepts used to design the flight experiment mission for SHIVA - Spaceflight Holography Investigation in a Virtual Apparatus. SHIVA is a NASA project that exploits a unique, holography-based, diagnostics tool to understand the behavior of small particles subjected to transient accelerations. The flight experiments are designed for testing model equations, measuring g, g-jitter, and other microgravity phenomena. Data collection will also include experiments lying outside of the realm of existing theory. The regime under scrutiny is the low Reynolds number, Stokes regime or creeping flow, which covers particles and bubbles moving at very low velocity. The equations describing this important regime have been under development and investigation for over 100 years and yet a complete analytical solution of the general equation had remained elusive yielding only approximations and numerical solutions. In the course of the ongoing NASA NRA, the first analytical solution of the general equation was produced by members of the investigator team using the mathematics of fractional derivatives. This opened the way to an even more insightful and important investigation of the phenomena in microgravity. Recent results include interacting particles, particle-wall interactions, bubbles, and Reynolds numbers larger than unity. The Space Station provides an ideal environment for SHIVA. Limited ground experiments have already confirmed some aspects of the theory. In general the space environment is required for the overall experiment, especially for cases containing very heavy particles, very light particles, bubbles, collections of particles and for characterization of the space environment and its effect on particle experiments. Lightweight particles and bubbles typically rise too fast in a gravitational field and heavy particles sink too fast. In a microgravity environment, heavy and light particles can be studied side-by-side for

  8. Polarization particle drift and quasi-particle invariants

    International Nuclear Information System (INIS)

    Sosenko, P.P.

    1995-01-01

    The second-order approximation in quasi-particle description of magnetized plasmas is studied. Reduced particle and guiding-centre velocities are derived taking account of the second-order renormalization and polarization drift modified owing to finite-Larmor-radius effects. The second-order adiabatic invariant of quasi-particle motion is found. Global adiabatic invariants for the magnetized plasma are revealed, and their possible role in energy exchange between particles and fields, nonlinear mode cascades and global plasma stability is shown. 49 refs

  9. Design and test results of a low-noise readout integrated circuit for high-energy particle detectors

    International Nuclear Information System (INIS)

    Zhang Mingming; Chen Zhongjian; Zhang Yacong; Lu Wengao; Ji Lijiu

    2010-01-01

    A low-noise readout integrated circuit for high-energy particle detector is presented. The noise of charge sensitive amplifier was suppressed by using single-side amplifier and resistors as source degeneration. Continuous-time semi-Gaussian filter is chosen to avoid switch noise. The peaking time of pulse shaper and the gain can be programmed to satisfy multi-application. The readout integrated circuit has been designed and fabricated using a 0.35 μm double-poly triple-metal CMOS technology. Test results show the functions of the readout integrated circuit are correct. The equivalent noise charge with no detector connected is 500-700 e in the typical mode, the gain is tunable within 13-130 mV/fC and the peaking time varies from 0.7 to 1.6 μs, in which the average gain is about 20.5 mV/fC, and the linearity reaches 99.2%. (authors)

  10. Particle theory and intense hadron facilities

    International Nuclear Information System (INIS)

    Ng, J.N.

    1989-05-01

    A brief overview of particle physics that can be done at an intense hadron facility (IHF) is given. The emphasis is placed on testing the standard model, light Higgs boson searches and CP violation, which are areas an IHF can do especially well

  11. The semileptonic decays of charmed particles

    International Nuclear Information System (INIS)

    Nabavi, R.P.; Pham, X.Y.; Cottingham, W.N.

    1977-01-01

    A general formalism is developped for analyzing the semileptonic decays of charmed particles in terms of helicity amplitudes. This formalism is to the D and F mesons, and a simple experimental test for the V+-A coupling of the charmed quark, is proposed

  12. Gaseous and particle emissions from an ethanol fumigated compression ignition engine

    International Nuclear Information System (INIS)

    Surawski, Nicholas C.; Ristovski, Zoran D.; Brown, Richard J.; Situ, Rong

    2012-01-01

    Highlights: ► Ethanol fumigation system fitted on a direct injection compression ignition engine. ► Ethanol substitutions up to 40% (by energy) were achieved. ► Gaseous and particle emissions were measured at intermediate speed. ► PM and NO emissions significantly reduced, whilst CO and HC increased. ► The number of particles emitted generally higher with ethanol fumigation. - Abstract: A 4-cylinder Ford 2701C test engine was used in this study to explore the impact of ethanol fumigation on gaseous and particle emission concentrations. The fumigation technique delivered vaporised ethanol into the intake manifold of the engine, using an injector, a pump and pressure regulator, a heat exchanger for vaporising ethanol and a separate fuel tank and lines. Gaseous (Nitric oxide (NO), Carbon monoxide (CO) and hydrocarbons (HC)) and particulate emissions (particle mass (PM 2.5 ) and particle number) testing was conducted at intermediate speed (1700 rpm) using 4 load settings with ethanol substitution percentages ranging from 10% to 40% (by energy). With ethanol fumigation, NO and PM 2.5 emissions were reduced, whereas CO and HC emissions increased considerably and particle number emissions increased at most test settings. It was found that ethanol fumigation reduced the excess air factor for the engine and this led to increased emissions of CO and HC, but decreased emissions of NO. PM 2.5 emissions were reduced with ethanol fumigation, as ethanol has a very low “sooting” tendency. This is due to the higher hydrogen-to-carbon ratio of this fuel, and also because ethanol does not contain aromatics, both of which are known soot precursors. The use of a diesel oxidation catalyst (as an after-treatment device) is recommended to achieve a reduction in the four pollutants that are currently regulated for compression ignition engines. The increase in particle number emissions with ethanol fumigation was due to the formation of volatile (organic) particles

  13. Particle Acceleration and Fractional Transport in Turbulent Reconnection

    Science.gov (United States)

    Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas; Anastasiadis, Anastasios

    2017-11-01

    We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1-2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker-Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

  14. Particle Acceleration and Fractional Transport in Turbulent Reconnection

    Energy Technology Data Exchange (ETDEWEB)

    Isliker, Heinz; Pisokas, Theophilos; Vlahos, Loukas [Department of Physics, Aristotle University of Thessaloniki, GR-52124 Thessaloniki (Greece); Anastasiadis, Anastasios [Institute for Astronomy, Astrophysics, Space Applications and Remote Sensing, National Observatory of Athens, GR-15236 Penteli (Greece)

    2017-11-01

    We consider a large-scale environment of turbulent reconnection that is fragmented into a number of randomly distributed unstable current sheets (UCSs), and we statistically analyze the acceleration of particles within this environment. We address two important cases of acceleration mechanisms when particles interact with the UCS: (a) electric field acceleration and (b) acceleration by reflection at contracting islands. Electrons and ions are accelerated very efficiently, attaining an energy distribution of power-law shape with an index 1–2, depending on the acceleration mechanism. The transport coefficients in energy space are estimated from test-particle simulation data, and we show that the classical Fokker–Planck (FP) equation fails to reproduce the simulation results when the transport coefficients are inserted into it and it is solved numerically. The cause for this failure is that the particles perform Levy flights in energy space, while the distributions of the energy increments exhibit power-law tails. We then use the fractional transport equation (FTE) derived by Isliker et al., whose parameters and the order of the fractional derivatives are inferred from the simulation data, and solving the FTE numerically, we show that the FTE successfully reproduces the kinetic energy distribution of the test particles. We discuss in detail the analysis of the simulation data and the criteria that allow one to judge the appropriateness of either an FTE or a classical FP equation as a transport model.

  15. Thermalhydraulics of flowing particle-bed-type fusion reactor blankets

    International Nuclear Information System (INIS)

    Nietert, R.E.; Abdelk-Khalik, S.I.

    1982-01-01

    An experimental investigation has been conducted to determine the heat transfer characteristics of gravity-flowing particle beds using a special heat transfer loop. Glass microspheres were allowed to flow by gravity at controlled rates through an electrically heated stainless steel tubular test section. Values of the local and average convective heat transfer coefficient as a function of the average bed velocity, particle size and heat flux were determined. Such information is necessary for the design of gravity-flowing particle-bed type fusion reactor-blankets and associated tritium recovery systems. (orig.)

  16. PREDICTION OF THE EXTREMAL SHAPE FACTOR OF SPHEROIDAL PARTICLES

    Directory of Open Access Journals (Sweden)

    Daniel Hlubinka

    2011-05-01

    Full Text Available In the stereological unfolding problem for spheroidal particles the extremal shape factor is predicted. The theory of extreme values has been used to show that extremes of the planar shape factor of particle sections tend to the same limit distribution as extremes of the original shape factor for both the conditional and marginal distribution. Attention is then paid to the extreme shape factor conditioned by the particle size. Normalizing constants are evaluated for a parametric model and the numerical procedure is tested on real data from metallography.

  17. Improved microstructure of cement-based composites through the addition of rock wool particles

    Energy Technology Data Exchange (ETDEWEB)

    Lin, Wei-Ting [Dept. of Civil Engineering, National Ilan University, Ilan 26047, Taiwan (China); Institute of Nuclear Energy Research, Atomic Energy Council, Taoyuan 32546, Taiwan (China); Cheng, An, E-mail: ancheng@niu.edu.tw [Dept. of Civil Engineering, National Ilan University, Ilan 26047, Taiwan (China); Huang, Ran; Zou, Si-Yu [Dept. of Harbor and River Engineering, National Taiwan Ocean University, Keelung 20224, Taiwan (China)

    2013-10-15

    Rock wool is an inorganic fibrous substance produced by steam blasting and cooling molten glass. As with other industrial by-products, rock wool particles can be used as cementitious materials or ultra fine fillers in cement-based composites. This study investigated the microstructure of mortar specimens produced with cement-based composites that include various forms of rock wool particles. It conducted compressive strength testing, rapid chloride penetration tests, X-ray diffraction analysis, thermo-gravimetric analysis, and scanning electronic microscopy to evaluate the macro- and micro-properties of the cement-based composites. Test results indicate that inclusion of rock wool particles in composites improved compressive strength and reduced chloride ion penetration at the age of 91 days due to the reduction of calcium hydroxide content. Microscopic analysis confirms that the use of rock wool particles contributed to the formation of a denser, more compact microstructure within the hardened paste. In addition, X-ray diffraction analysis shows few changes in formation of pozzolanic reaction products and no new hydrations are formed with incorporating rock wool particles. - Highlights: • We report the microstructural characterization of cement-based composites. • Different mixes produced with various rock wool particles have been tested. • The influence of different mixes on macro and micro properties has been discussed. • The macro properties are included compressive strength and permeability. • XRD and SEM observations confirm the pozzolanic reaction in the resulting pastes.

  18. Stability of MC Carbide Particles Size in Creep Resisting Steels

    Directory of Open Access Journals (Sweden)

    Vodopivec, F.

    2006-01-01

    Full Text Available Theoretical analysis of the dependence microstructure creep rate. Discussion on the effects of carbide particles size and their distribution on the base of accelerated creep tests on a steel X20CrMoV121 tempered at 800 °C. Analysis of the stability of carbide particles size in terms of free energy of formation of the compound. Explanation of the different effect of VC and NbC particles on accelerated creep rate.

  19. Astro particle physics view on supersymmetry

    International Nuclear Information System (INIS)

    Fornengo, N.

    2010-01-01

    The particle physics interpretation of the missing-mass, or dark-matter, problem of cosmological and astrophysical nature is going to be posed under deep scrutiny in the next years. From the particle physics side, accelerator physics will deeply test theoretical ideas of new physics beyond the Standard Model, where a particle physics candidate to dark matter is often naturally obtained. From the astrophysical side, many probes are already providing a great deal of independent information on the signals which can be produced by the galactic or extra-galactic dark matter. The ultimate hope is in fact to be able to disentangle a dark matter signal from the various sources of backgrounds and to extract a coherent picture of new physics from the accelerator physics, astrophysics and cosmology side. A very ambitious and far-reaching project, indeed.

  20. Flow-controlled magnetic particle manipulation

    Science.gov (United States)

    Grate, Jay W [West Richland, WA; Bruckner-Lea, Cynthia J [Richland, WA; Holman, David A [Las Vegas, NV

    2011-02-22

    Inventive methods and apparatus are useful for collecting magnetic materials in one or more magnetic fields and resuspending the particles into a dispersion medium, and optionally repeating collection/resuspension one or more times in the same or a different medium, by controlling the direction and rate of fluid flow through a fluid flow path. The methods provide for contacting derivatized particles with test samples and reagents, removal of excess reagent, washing of magnetic material, and resuspension for analysis, among other uses. The methods are applicable to a wide variety of chemical and biological materials that are susceptible to magnetic labeling, including, for example, cells, viruses, oligonucleotides, proteins, hormones, receptor-ligand complexes, environmental contaminants and the like.

  1. Particle detection with superconducting tunnel junctions

    International Nuclear Information System (INIS)

    Jany, P.

    1990-08-01

    At the Institute of Experimental Nuclear Physics of the University of Karlsruhe (TH) and at the Institute for Nuclear Physics of the Kernforschungszentrum Karlsruhe we started to produce superconducting tunnel junctions and to investigate them for their suitability as particle detectors. The required facilities for the production of tunnel junctions and the experimental equipments to carry out experiments with them were erected. Experiments are presented in which radiations of different kinds of particles could successfully be measured with the tunnel junctions produced. At first we succeeded in detectioning light pulses of a laser. In experiments with alpha-particles of an energy of 4,6 MeV the alpha-particles were detected with an energy resolution of 1,1%, and it was shown in specific experiments that the phonons originating from the deposition of energy by an alpha-particle in the substrate can be detected with superconducting tunnel junctions at the surface. On that occasion it turned out that the signals could be separated with respect to their point of origin (tunnel junction, contact leads, substrate). Finally X-rays with an energy of 6 keV were detected with an energy resolution of 8% in a test arrangement that makes use of the so-called trapping effect to read out a larger absorber volume. (orig.) [de

  2. Review of particle properties. 25th anniversary edition

    International Nuclear Information System (INIS)

    1982-04-01

    This review is a reprint of Physics Letters, Vol. IIIB, April 22, 1982, and is an updating through December 1981 of our previous review of particle properties [Particle Data Group (1980)]. As in previous editions we have attempted to make the text as complete and self-contained as possible. The results of our compilation are presented in two sections, the Tables of Particle Properties and the Data Card Listings. The Tables summarize the properties of only those particles whose existence is in our judgment experimentally well founded and which have a high probability of standing the test of time. The Data Card Listings give up-to-date information, with references, on all reported particles, whether considered well established or not. The Listings also contain mini-reviews on questions of interest. As in previous editions, we include a section of miscellaneous tables, figures, and formulae. These are aimed at the practicing high energy physics experimentalist

  3. Performance comparison of scintillators for alpha particle detectors

    Energy Technology Data Exchange (ETDEWEB)

    Morishita, Yuki [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Yamamoto, Seiichi [Graduate School of Medicine, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, Aichi 461-8673 (Japan); Izaki, Kenji [Japan Atomic Energy Agency, Muramatsu 4-33, Tokai-mura, Ibaraki 319-1194 (Japan); Kaneko, Junichi H.; Toui, Kohei; Tsubota, Youichi; Higuchi, Mikio [Graduate School of Engineering, Hokkaido University, Kita 13, Nishi 8, Kita-ku, Sapporo, Hokkaido 060-8628 (Japan)

    2014-11-11

    Scintillation detectors for alpha particles are often used in nuclear fuel facilities. Alpha particle detectors have also become important in the research field of radionuclide therapy using alpha emitters. ZnS(Ag) is the most often used scintillator for alpha particle detectors because its light output is high. However, the energy resolution of ZnS(Ag)-based scintillation detectors is poor because they are not transparent. A new ceramic sample, namely the cerium doped Gd{sub 2}Si{sub 2}O{sub 7} (GPS) scintillator, has been tested as alpha particle detector and its performances have been compared to that one of three different scintillating materials: ZnS(Ag), GAGG and a standard plastic scintillator. The different scintillating materials have been coupled to two different photodetectors, namely a photomultiplier tube (PMT) and a Silicon Photo-multiplier (Si-PM): the performances of each detection system have been compared. Promising results as far as the energy resolution performances (10% with PMT and 14% with Si-PM) have been obtained in the case of GPS and GAGG samples. Considering the quantum efficiencies of the photodetectors under test and their relation to the emission wavelength of the different scintillators, the best results were achieved coupling the GPS with the PMT and the GAGG with the Si-PM.

  4. Acoustic detection of melt particles

    International Nuclear Information System (INIS)

    Costley, R.D. Jr.

    1988-01-01

    The Reactor Safety Research Department at Sandia National Laboratories is investigating a type of Loss of Coolant Accident (LOCA). In this particular type of accident, core meltdown occurs while the pressure within the reactor pressure vessel (RPV) is high. If one of the instrument tube penetrations in the lower head fails, melt particles stream through the cavity and into the containment vessel. This experiment, which simulates this type accident, was performed in the Surtsev Direct Heating Test Facility which is approximately a 1:10 linear scaling of a large dry containment volume. A 1:10 linear scale model of the reactor cavity was placed near the bottom of the Surtsey vessel so that the exit of the cavity was at the vertical centerline of the vessel. A pressure vessel used to create the simulated molten core debris was located at the scaled height of the RPV. In order to better understand how the melt leaves the cavity and streams into the containment an array of five acoustic sensors was placed directly in the path of the melt particles about 30 feet from the exit of the sealed cavity. Highly damped, broadband sensors were chosen to minimize ringing so that individual particle hits could be detected. The goal was to count the signals produced by the individual particle hits to get some idea of how the melt particles left the cavity. This document presents some of the results of the experiment. 9 figs

  5. Genetic Learning Particle Swarm Optimization.

    Science.gov (United States)

    Gong, Yue-Jiao; Li, Jing-Jing; Zhou, Yicong; Li, Yun; Chung, Henry Shu-Hung; Shi, Yu-Hui; Zhang, Jun

    2016-10-01

    Social learning in particle swarm optimization (PSO) helps collective efficiency, whereas individual reproduction in genetic algorithm (GA) facilitates global effectiveness. This observation recently leads to hybridizing PSO with GA for performance enhancement. However, existing work uses a mechanistic parallel superposition and research has shown that construction of superior exemplars in PSO is more effective. Hence, this paper first develops a new framework so as to organically hybridize PSO with another optimization technique for "learning." This leads to a generalized "learning PSO" paradigm, the *L-PSO. The paradigm is composed of two cascading layers, the first for exemplar generation and the second for particle updates as per a normal PSO algorithm. Using genetic evolution to breed promising exemplars for PSO, a specific novel *L-PSO algorithm is proposed in the paper, termed genetic learning PSO (GL-PSO). In particular, genetic operators are used to generate exemplars from which particles learn and, in turn, historical search information of particles provides guidance to the evolution of the exemplars. By performing crossover, mutation, and selection on the historical information of particles, the constructed exemplars are not only well diversified, but also high qualified. Under such guidance, the global search ability and search efficiency of PSO are both enhanced. The proposed GL-PSO is tested on 42 benchmark functions widely adopted in the literature. Experimental results verify the effectiveness, efficiency, robustness, and scalability of the GL-PSO.

  6. A CMOS integrated pulse mode alpha-particle counter for application in radon monitoring

    International Nuclear Information System (INIS)

    Ahmed, A.; Walkey, D.J.; Tarr, N.G.

    1997-01-01

    A custom integrated circuit for detecting alpha particles for application in the monitoring of radon has been designed and tested. The design uses the reverse-biased well to a substrate capacitance of a p-n junction in a conventional CMOS process as a sense capacitor for incident alpha particles. A simple CMOS inverter is used as an analog amplifier to detect the small potential change induced by an alpha-particle strike on the sense capacitor. The design was implemented in a 1.2-microm conventional CMOS process with a sense capacitor area of 110 microm 2 . Tests carried out under vacuum conditions using a calibrated 241 Am alpha-particle source showed an output voltage swing of ≥2.0 V for an alpha event. The detector is also shown to have good immunity to noise and high-quantum efficiency for alpha particles

  7. Fission Product Release Behavior of Individual Coated Fuel Particles for High-Temperature Gas-Cooled Reactors

    Energy Technology Data Exchange (ETDEWEB)

    Minato, Kazuo [Japan Atomic Energy Research Institute (Japan); Sawa, Kazuhiro [Japan Atomic Energy Research Institute (Japan); Koya, Toshio [Japan Atomic Energy Research Institute (Japan); Tomita, Takeshi [Japan Atomic Energy Research Institute (Japan); Ishikawa, Akiyoshi [Japan Atomic Energy Research Institute (Japan); Baldwin, Charles A; Gabbard, William Alexander [Oak Ridge National Laboratory (United States); Malone, Charlie M [Oak Ridge National Laboratory (United States)

    2000-07-15

    Postirradiation heating tests of TRISO-coated UO{sub 2} particles at 1700 and 1800degC were performed to understand fission product release behavior at accident temperatures. The inventory measurements of the individual particles were carried out before and after the heating tests with gamma-ray spectrometry to study the behavior of the individual particles. The time-dependent release behavior of {sup 85}Kr, {sup 110m}Ag, {sup 134}Cs, {sup 137}Cs, and {sup 154}Eu were obtained with on-line measurements of fission gas release and intermittent measurements of metallic fission product release during the heating tests. The inventory measurements of the individual particles revealed that fission product release behavior of the individual particles was not uniform, and large particle-to-particle variations in the release behavior of {sup 110m}Ag, {sup 134}Cs, {sup 137}Cs, and {sup 154}Eu were found. X-ray microradiography and ceramography showed that the variations could not be explained by only the presence or absence of cracks in the SiC coating layer. The SiC degradation may have been related to the variations.

  8. Hunting for dark particles with gravitational waves

    Energy Technology Data Exchange (ETDEWEB)

    Giudice, Gian F.; McCullough, Matthew; Urbano, Alfredo [CERN, Theoretical Physics Department,Geneva (Switzerland)

    2016-10-03

    The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of astronomical size, then the first evidence for such objects, and their underlying microphysical description, may arise in gravitational wave observations. In this work we study how the macroscopic properties of ECOs are related to their microscopic properties, such as dark particle mass and couplings. We then demonstrate the smoking gun exotic signatures that would provide observational evidence for ECOs, and hence new particles, in terrestrial gravitational wave observatories. Finally, we discuss how gravitational waves can test a core concept in general relativity: Hawking’s area theorem.

  9. Hunting for Dark Particles with Gravitational Waves

    Science.gov (United States)

    Giudice, Gian F.

    2017-12-01

    The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of astronomical size, then the first evidence for such objects, and their underlying microphysical description, may arise in gravitational wave observations. In this work we study how the macroscopic properties of ECOs are related to their microscopic properties, such as dark particle mass and couplings. We then demonstrate the smoking gun exotic signatures that would provide observational evidence for ECOs, and hence new particles, in terrestrial gravitational wave observatories. Finally, we discuss how gravitational waves can test a core concept in general relativity: Hawking's area theorem.

  10. Hunting for dark particles with gravitational waves

    International Nuclear Information System (INIS)

    Giudice, Gian F.; McCullough, Matthew; Urbano, Alfredo

    2016-01-01

    The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of astronomical size, then the first evidence for such objects, and their underlying microphysical description, may arise in gravitational wave observations. In this work we study how the macroscopic properties of ECOs are related to their microscopic properties, such as dark particle mass and couplings. We then demonstrate the smoking gun exotic signatures that would provide observational evidence for ECOs, and hence new particles, in terrestrial gravitational wave observatories. Finally, we discuss how gravitational waves can test a core concept in general relativity: Hawking’s area theorem.

  11. Hunting for Dark Particles with Gravitational Waves

    CERN Document Server

    Giudice, Gian F.; Urbano, Alfredo

    2016-01-01

    The LIGO observation of gravitational waves from a binary black hole merger has begun a new era in fundamental physics. If new dark sector particles, be they bosons or fermions, can coalesce into exotic compact objects (ECOs) of astronomical size, then the first evidence for such objects, and their underlying microphysical description, may arise in gravitational wave observations. In this work we study how the macroscopic properties of ECOs are related to their microscopic properties, such as dark particle mass and couplings. We then demonstrate the smoking gun exotic signatures that would provide observational evidence for ECOs, and hence new particles, in terrestrial gravitational wave observatories. Finally, we discuss how gravitational waves can test a core concept in general relativity: Hawking's area theorem.

  12. Elementary particles and particle interactions

    International Nuclear Information System (INIS)

    Bethge, K.; Schroeder, U.E.

    1986-01-01

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

  13. Rare particles

    International Nuclear Information System (INIS)

    Kutschera, W.

    1984-01-01

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

  14. Science and technology of kernels and TRISO coated particle sorting

    International Nuclear Information System (INIS)

    Nothnagel, G.

    2006-09-01

    The ~1mm diameter TRISO coated particles, which form the elemental units of PBMR nuclear fuel, has to be close to spherical in order to best survive damage during sphere pressing. Spherical silicon carbide layers further provide the strongest miniature pressure vessels for fission product retention. To make sure that the final product contains particles of acceptable shape, 100% of kernels and coated particles have to be sorted on a surface-ground sorting table. Broken particles, twins, irregular (odd) shapes and extreme ellipsoids have to be separated from the final kernel and coated particle batches. Proper sorting of particles is an extremely important step in quality fuel production as the final failure fraction depends sensitively on the quality of sorting. After sorting a statistically significant sample of the sorted product is analysed for sphericity, which is defined as the ratio of maximum to minimum diameter, as part of a standard QC test to ensure conformance to German specifications. In addition a burn-leach test is done on coated particles (before pressing) and fuel spheres (after pressing) to ensure adherence to failure specifications. Because of the extreme importance of particle sorting for assurance of fuel quality it is essential to have an in-depth understanding of the capabilities and limitations of particle sorting. In this report a systematic scientific rationale is developed, from fundamental principles, to provide a basis for understanding the relationship between product quality and sorting parameters. The principles and concepts, developed in this report, will be of importance when future sorting tables (or equivalents) are to be designed. A number of new concepts and methodologies are developed to assist with equivalence validation of any two sorting tables. This is aimed in particular towards quantitative assessment of equivalence between current QC tables (closely based on the original NUKEM parameters, except for the driving mechanism

  15. Dust generation in powders: Effect of particle size distribution

    Directory of Open Access Journals (Sweden)

    Chakravarty Somik

    2017-01-01

    Full Text Available This study explores the relationship between the bulk and grain-scale properties of powders and dust generation. A vortex shaker dustiness tester was used to evaluate 8 calcium carbonate test powders with median particle sizes ranging from 2μm to 136μm. Respirable aerosols released from the powder samples were characterised by their particle number and mass concentrations. All the powder samples were found to release respirable fractions of dust particles which end up decreasing with time. The variation of powder dustiness as a function of the particle size distribution was analysed for the powders, which were classified into three groups based on the fraction of particles within the respirable range. The trends we observe might be due to the interplay of several mechanisms like de-agglomeration and attrition and their relative importance.

  16. Stress, Flow and Particle Transport in Rock Fractures

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Tomofumi

    2007-09-15

    The fluid flow and tracer transport in a single rock fracture during shear processes has been an important issue in rock mechanics and is investigated in this thesis using Finite Element Method (FEM) and streamline particle tracking method, considering evolutions of aperture and transmissivity with shear displacement histories under different normal stresses, based on laboratory tests. The distributions of fracture aperture and its evolution during shear were calculated from the initial aperture fields, based on the laser-scanned surface roughness features of replicas of rock fracture specimens, and shear dilations measured during the coupled shear-flow-tracer tests in laboratory performed using a newly developed testing apparatus in Nagasaki University, Nagasaki, Japan. Three rock fractures of granite with different roughness characteristics were used as parent samples from which nine plaster replicas were made and coupled shear-flow tests was performed under three normal loading conditions (two levels of constant normal loading (CNL) and one constant normal stiffness (CNS) conditions). In order to visualize the tracer transport, transparent acrylic upper parts and plaster lower parts of the fracture specimens were manufactured from an artificially created tensile fracture of sandstone and the coupled shear-flow tests with fluid visualization was performed using a dye tracer injected from upstream and a CCD camera to record the dye movement. A special algorithm for treating the contact areas as zero-aperture elements was used to produce more accurate flow field simulations by using FEM, which is important for continued simulations of particle transport, but was often not properly treated in literature. The simulation results agreed well with the flow rate data obtained from the laboratory tests, showing that complex histories of fracture aperture and tortuous flow channels with changing normal stresses and increasing shear displacements, which were also captured

  17. Modeling of coated fuel particles irradiation behavior

    International Nuclear Information System (INIS)

    Liang Tongxiang; Phelip, M.

    2006-01-01

    In this report, PANAMA code was used to estimate the CP performance under normal and accident condition. Under the normal irradiation test (1000 degree C 625 efpd, 10% FIMA), for intact CP fuel, failure fraction is in the level of 10 -7 . As-fabricated SiC failed particles results in the through coatings failed particles much earlier than the intact particles does, OPyC layer does not fail immediately after irradiation starts. The significant failures start at beyond the burnup of about 7% FIMA. Under the accident condition, the calculated results showed that when the heating temperature is much higher than 1850 degree C, the failure fraction of coated particle can reach the level of 1 percent. The CP fuel fails significantly if it has a buffer layer thinner than 65 urn, SiC layer thinner than 30 μm. High burnup CP need to develop small size kernel, thick buffer layer and thick SiC layer. (authors)

  18. Effect of limestone particle size on egg production and eggshell ...

    African Journals Online (AJOL)

    Different limestone particle sizes had no effect on any of the tested egg production and eggshell quality parameters. These results suggested that larger particles limestone are not necessarily essential to provide sufficient Ca2+ to laying hens for egg production and eggshell quality at end-of-lay, provided that the dietary Ca ...

  19. A dynamic global and local combined particle swarm optimization algorithm

    International Nuclear Information System (INIS)

    Jiao Bin; Lian Zhigang; Chen Qunxian

    2009-01-01

    Particle swarm optimization (PSO) algorithm has been developing rapidly and many results have been reported. PSO algorithm has shown some important advantages by providing high speed of convergence in specific problems, but it has a tendency to get stuck in a near optimal solution and one may find it difficult to improve solution accuracy by fine tuning. This paper presents a dynamic global and local combined particle swarm optimization (DGLCPSO) algorithm to improve the performance of original PSO, in which all particles dynamically share the best information of the local particle, global particle and group particles. It is tested with a set of eight benchmark functions with different dimensions and compared with original PSO. Experimental results indicate that the DGLCPSO algorithm improves the search performance on the benchmark functions significantly, and shows the effectiveness of the algorithm to solve optimization problems.

  20. Well installation, single-well testing, and particle-size analysis for selected sites in and near the Lost Creek Designated Ground Water Basin, north-central Colorado, 2003-2004

    Science.gov (United States)

    Beck, Jennifer A.; Paschke, Suzanne S.; Arnold, L. Rick

    2011-01-01

    This report describes results from a groundwater data-collection program completed in 2003-2004 by the U.S. Geological Survey in support of the South Platte Decision Support System and in cooperation with the Colorado Water Conservation Board. Two monitoring wells were installed adjacent to existing water-table monitoring wells. These wells were installed as well pairs with existing wells to characterize the hydraulic properties of the alluvial aquifer and shallow Denver Formation sandstone aquifer in and near the Lost Creek Designated Ground Water Basin. Single-well tests were performed in the 2 newly installed wells and 12 selected existing monitoring wells. Sediment particle size was analyzed for samples collected from the screened interval depths of each of the 14 wells. Hydraulic-conductivity and transmissivity values were calculated after the completion of single-well tests on each of the selected wells. Recovering water-level data from the single-well tests were analyzed using the Bouwer and Rice method because test data most closely resembled those obtained from traditional slug tests. Results from the single-well test analyses for the alluvial aquifer indicate a median hydraulic-conductivity value of 3.8 x 10-5 feet per second and geometric mean hydraulic-conductivity value of 3.4 x 10-5 feet per second. Median and geometric mean transmissivity values in the alluvial aquifer were 8.6 x 10-4 feet squared per second and 4.9 x 10-4 feet squared per second, respectively. Single-well test results for the shallow Denver Formation sandstone aquifer indicate a median hydraulic-conductivity value of 5.4 x 10-6 feet per second and geometric mean value of 4.9 x 10-6 feet per second. Median and geometric mean transmissivity values for the shallow Denver Formation sandstone aquifer were 4.0 x 10-5 feet squared per second and 5.9 x 10-5 feet squared per second, respectively. Hydraulic-conductivity values for the alluvial aquifer in and near the Lost Creek Designated

  1. Entanglement between particle partitions in itinerant many-particle states

    NARCIS (Netherlands)

    Haque, M.; Zozulya, O.S.; Schoutens, K.

    2009-01-01

    We review 'particle-partitioning entanglement' for itinerant many-particle systems. This is defined as the entanglement between two subsets of particles making up the system. We identify generic features and mechanisms of particle entanglement that are valid over whole classes of itinerant quantum

  2. Negative numbers and antimatter particles

    International Nuclear Information System (INIS)

    Tsan, Ung Chan

    2012-01-01

    Dirac's equation states that an electron implies the existence of an antielectron with the same mass (more generally same arithmetic properties) and opposite charge (more generally opposite algebraic properties). Subsequent observation of antielectron validated this concept. This statement can be extended to all matter particles; observation of antiproton, antineutron, antideuton … is in complete agreement with this view. Recently antihypertriton was observed and 38 atoms of antihydrogen were trapped. This opens the path for use in precise testing of nature's fundamental symmetries. The symmetric properties of a matter particle and its mirror antimatter particle seem to be well established. Interactions operate on matter particles and antimatter particles as well. Conservation of matter parallels addition operating on positive and negative numbers. Without antimatter particles, interactions of the Standard Model (electromagnetism, strong interaction and weak interaction) cannot have the structure of group. Antimatter particles are characterized by negative baryonic number A or/and negative leptonic number L. Materialization and annihilation obey conservation of A and L (associated to all known interactions), explaining why from pure energy (A = 0, L = 0) one can only obtain a pair of matter particle antimatter particle — electron antielectron, proton and antiproton — via materialization where the mass of a pair of particle antiparticle gives back to pure energy with annihilation. These two mechanisms cannot change the difference in the number of matter particles and antimatter particles. Thus from pure energy only a perfectly symmetric (in number) universe could be generated as proposed by Dirac but observation showed that our universe is not symmetric, it is a matter universe which is nevertheless neutral. Fall of reflection symmetries shattered the prejudice that there is no way to define in an absolute way right and left or matter and antimatter

  3. Particle emissions from compressed natural gas engines

    International Nuclear Information System (INIS)

    Ristovski, Z.D.; Morawska, L.; Hitchins, J.; Thomas, S.; Greenaway, C.; Gilbert, D.

    2000-01-01

    This paper presents the results of measurements conducted to determine particle and gas emissions from two large compressed natural gas (CNG) spark ignition (SI) engines. Particle size distributions in the range from 0.01-30 μm, and gas composition were measured for five power settings of the engines: 35, 50, 65, 80 and 100% of full power. Particle emissions in the size range between 0.5 and 30 μm, measured by the aerodynamic particle sizer (APS), were very low at a level below two particles cm -3 . These concentrations were comparable with average ambient concentration, and were not considered in the succeeding analysis. Both engines produce significant amounts of particles in the size range between 0.015 and 0.7 μm, measured by the scanning mobility particle size (SMPS). Maximum number of concentrations of about 1 x 10 7 particles cm -3 were very similar for both engines. The CMDs were in the range between 0.020 and 0.060 μm. The observed levels of particulate emission are in terms of number of the same order as emissions from heavy duty diesel engines (Morawska et al., Environ. Sci. Tech. 32, 2033-2042). On the other hand, emissions of CO and NO x of 5.53 and 3.33 g k W h -1 , respectively, for one of the tested engines, were considerably lower than set by the standards. According to the specifications for the gas emissions, provided by the US EPA (US EPA, 1997), this engine can be considered as a 'low-emission' engine, although emissions of submicrometer particles are of the same order as heavy-duty vehicles. (Author)

  4. Influence of suspended particles on the emission of organophosphate flame retardant from insulation boards.

    Science.gov (United States)

    Lazarov, Borislav; Swinnen, Rudi; Poelmans, David; Spruyt, Maarten; Goelen, Eddy; Covaci, Adrian; Stranger, Marianne

    2016-09-01

    The influence of the presence of the so-called seed particles on the emission rate of Tris (1-chloroisopropyl) phosphate (TCIPP) from polyisocyanurate (PIR) insulation boards was investigated in this study. Two Field and Laboratory Emission Test cells (FLEC) were placed on the surface of the same PIR board and respectively supplied with clean air (reference FLEC) and air containing laboratory-generated soot particles (test FLEC). The behavior of the area-specific emission rates (SER A ) over a time period of 10 days was studied by measuring the total (gas + particles) concentrations of TCIPP at the exhaust of each FLEC. The estimated SER A of TCIPP from the PIR board at the quasi-static equilibrium were found to be 0.82 μg m(-2) h(-1) in the absence of seed particles, while the addition of soot particles led to SER A of 2.16 μg m(-2) h(-1). This indicates an increase of the SER A of TCIPP from the PIR board with a factor of 3 in the presence of soot particles. The TCIPP partition coefficient to soot particles at the quasi-static equilibrium was 0.022 ± 0.012 m(3) μg(-1). In the next step, the influence of real-life particles on TCIPP emission rates was investigated by supplying the test FLEC with air from a professional kitchen where mainly frying and baking activities took place. Similar to the reference FLEC outcomes, SER A was also found to increase in this real-life experiment over a time period of 20 days by a factor 3 in the presence of particles generated during cooking activities. The median value of estimated particle-gas coefficient for this test was 0.062 ± 0.037 m(3) μg(-1).

  5. Digital stereo-holographic microscopy for studying three-dimensional particle dynamics

    Science.gov (United States)

    Byeon, Hyeokjun; Go, Taesik; Lee, Sang Joon

    2018-06-01

    A digital stereo-holographic microscopy (DsHM) with two viewing angles is proposed to measure 3D information of microscale particles. This approach includes two volumetric recordings and numerical reconstruction, and it involves the combination of separately reconstructed holograms. The 3D positional information of a particle was determined by searching the center of the overlapped reconstructed volume. After confirming the proposed technique using static spherical particles, the 3D information of moving particles suspended in a Hagen-Poiseiulle flow was successfully obtained. Moreover, the 3D information of nonspherical particles, including ellipsoidal particles and red blood cells, were measured using the proposed technique. In addition to 3D positional information, the orientation and shape of the test samples were obtained from the plane images by slicing the overlapped volume perpendicular to the directions of the image recordings. This DsHM technique will be useful in analyzing the 3D dynamic behavior of various nonspherical particles, which cannot be measured by conventional digital holographic microscopy.

  6. Toxic assessment of urban atmospheric particle-bound PAHs: Relevance of composition and particle size in Barcelona (Spain)

    International Nuclear Information System (INIS)

    Mesquita, Sofia Raquel; Drooge, Barend L. van; Reche, Cristina; Guimarães, Laura; Grimalt, Joan O.; Barata, Carlos; Piña, Benjamin

    2014-01-01

    Zebrafish embryotoxicity and dioxin-like activity levels were tested for particulate air samples from an urban background site in Barcelona (Spain). Samples were collected during 14 months, and maximal values for both biological activities corresponded to samples collected during late autumn months, correlating with elevated PAH levels. Vehicle and combustion emissions appeared as the potentially most toxic sources, whereas total PM mass and mineral content appeared to be poor predictors of the biological activity of the samples. Samples simultaneously collected at different particle size cut-offs (10, 2.5, and 1 μm) did not differ significantly in dioxin-like PAH levels and biological activity, indicating that the sub-micron particle fraction (PM 1 ) concentrated essentially all observed toxicity. Our results support the need for a tighter control on sub-micron particle emissions and show that total PM mass and, particularly, PM 10 , may not fully characterize the toxic potential of air samples. Highlights: • Dioxin-like activity was found in all air particle samples collected in Barcelona. • 50% of the samples showed different levels of fish embryotoxicity. • Toxic effects associated to PAHs and linked to vehicle and combustion emissions. • The toxicity was not correlated to PM mass or mineral content. • The sub-micron particle fraction PM 1 concentrated essentially all observed toxicity. -- In vivo toxic effects associated to sub-micron urban air particles from combustion and vehicle emissions

  7. Solving for the particle-number-projected HFB wavefunction

    International Nuclear Information System (INIS)

    Jia, L.Y.

    2015-01-01

    Recently we proposed a particle-number-conserving theory for nuclear pairing (Jia, 2013) [19] through the generalized density matrix formalism. The relevant equations were solved for the case when each single-particle level has a distinct set of quantum numbers and could only pair with its time-reversed partner (BCS-type Hamiltonian). In this work we consider the more general situation when several single-particle levels could have the same set of quantum numbers and pairing among these levels is allowed (HFB-type Hamiltonian). The pair condensate wavefunction (the HFB wavefunction projected onto good particle number) is determined by the equations of motion for density matrix operators instead of the variation principle. The theory is tested in the simple two-level model with factorizable pairing interactions, and semi-realistic models with the zero-range delta interaction and the realistic Bonn-CD interaction

  8. Non-identical particle femtoscopy in models with single freeze-out

    International Nuclear Information System (INIS)

    Kisiel, Adam

    2007-01-01

    We present femtoscopic results from hydrodynamics-inspired thermal models with single freeze-out. Non-identical particle femtoscopy is studied and compared to results of identical particle correlations. Special emphasis is put on shifts between average space-time emission points of non-identical particles of different masses. They are found to be sensitive to both the spatial shift coming from radial flow, as well as average emission time difference coming from the resonance decays. The Terminator Monte-Carlo program was chosen for this study because it realistically models both of these effects. In order to analyze the results we present and test the methodology of non-identical particle correlations. (author)

  9. Motion of particles of non-zero rest masses exterior to ...

    African Journals Online (AJOL)

    In this article, we extend the metric tensor exterior to astrophysically real or imaginary spherical distributions of mass whose tensor field varies with polar angle only; to derive equations of motion for test particles in this field. The time, radial, polar and azimuthal equations of motion for particles of non-zero rest masses moving ...

  10. Effect of Particle Size on Mechanical Properties of Sawdust-High Density Polyethylene Composites under Various Strain Rates

    Directory of Open Access Journals (Sweden)

    Haliza Jaya

    2016-06-01

    Full Text Available There is a need to understand the effect of wood particle size, as it affects the characteristics of wood-based composites. This study considers the effect of wood particle size relative to the dynamic behavior of wood composites. The compression Split Hopkinson Pressure Bar (SHPB was introduced to execute dynamic compression testing at the strain rate of 650 s-1, 900 s-1, and 1100 s-1, whereas a conventional universal testing machine (UTM was used to perform static compression testing at the strain rate of 0.1 s-1, 0.01 s-1, and 0.001 s-1 for four different particle sizes (63 µm, 125 µm, 250 µm, and 500 µm. The results showed that mechanical properties of composites were positively affected by the particle sizes, where the smallest particle size gave the highest values compared to the others. Moreover, the particle size also affected the rate sensitivity and the thermal activation volume of sawdust/HDPE, where smaller particles resulted in lower rate sensitivity. For the post-damage analysis, the applied strain rates influenced deformation behavior differently for all particle sizes of the specimens. In a fractographic analysis under dynamic loading, the composites with large particles experienced severe catastrophic deformation and damages compared to the smaller particles.

  11. Bayesian approach to MSD-based analysis of particle motion in live cells.

    Science.gov (United States)

    Monnier, Nilah; Guo, Syuan-Ming; Mori, Masashi; He, Jun; Lénárt, Péter; Bathe, Mark

    2012-08-08

    Quantitative tracking of particle motion using live-cell imaging is a powerful approach to understanding the mechanism of transport of biological molecules, organelles, and cells. However, inferring complex stochastic motion models from single-particle trajectories in an objective manner is nontrivial due to noise from sampling limitations and biological heterogeneity. Here, we present a systematic Bayesian approach to multiple-hypothesis testing of a general set of competing motion models based on particle mean-square displacements that automatically classifies particle motion, properly accounting for sampling limitations and correlated noise while appropriately penalizing model complexity according to Occam's Razor to avoid over-fitting. We test the procedure rigorously using simulated trajectories for which the underlying physical process is known, demonstrating that it chooses the simplest physical model that explains the observed data. Further, we show that computed model probabilities provide a reliability test for the downstream biological interpretation of associated parameter values. We subsequently illustrate the broad utility of the approach by applying it to disparate biological systems including experimental particle trajectories from chromosomes, kinetochores, and membrane receptors undergoing a variety of complex motions. This automated and objective Bayesian framework easily scales to large numbers of particle trajectories, making it ideal for classifying the complex motion of large numbers of single molecules and cells from high-throughput screens, as well as single-cell-, tissue-, and organism-level studies. Copyright © 2012 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  12. Alpha particles spectrometer with photodiode PIN

    International Nuclear Information System (INIS)

    Chacon R, A.; Hernandez V, R.; Hernandez D, V. M.; Vega C, H. R.; Ramirez G, J.

    2009-10-01

    The radiation propagates in form of electromagnetic waves or corpuscular radiation; if the radiation energy causes ionization in environment that crosses it is considered ionizing radiation. To detect radiation several detectors types are used, if the radiation are alpha particles are used detectors proportional type or trace elements. In this work the design results, construction and tests of an alpha particles spectrometer are presented, which was designed starting from a photodiode PIN type. The system design was simulated with a code for electronic circuits. With results of simulation phase was constructed the electronic phase that is coupled to a multichannel analyzer. The resulting electronic is evaluated analyzing the electronic circuit performance before an alphas triple source and alpha radiation that produce two smoke detectors of domestic use. On the tests phase we find that the system allows obtain, in a multichannel, the pulses height spectrum, with which we calibrate the system. (Author)

  13. Particle physics prospects for the KAON factory

    International Nuclear Information System (INIS)

    Bryman, D.

    1989-05-01

    The Kaon Factory at TRIUMF will produce beams of kaons, antiprotons, neutrinos and other particles with a hundred-fold increase in intensity over existing machines in the 30 GeV region. This will make possible new high precision experiments designed to test current ideas as well as high sensitivity measurements which could potentially reveal new effects. A sample of particle physics experiments involving rare kaon decays, CP and T violation studies, neutrino properties and reactions and light quark spectroscopy which might take advantage of the new opportunities presented by the Kaon Factory is discussed

  14. THE EFFECT OF COOLING ON PARTICLE TRAJECTORIES AND ACCELERATION IN RELATIVISTIC MAGNETIC RECONNECTION

    Energy Technology Data Exchange (ETDEWEB)

    Kagan, Daniel; Nakar, Ehud [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Tel Aviv 69978 (Israel); Piran, Tsvi, E-mail: daniel.kagan@mail.huji.ac.il [Racah Institute of Physics, The Hebrew University, Jerusalem 91904 (Israel)

    2016-12-20

    The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region with and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.

  15. THE EFFECT OF COOLING ON PARTICLE TRAJECTORIES AND ACCELERATION IN RELATIVISTIC MAGNETIC RECONNECTION

    International Nuclear Information System (INIS)

    Kagan, Daniel; Nakar, Ehud; Piran, Tsvi

    2016-01-01

    The maximum synchrotron burnoff limit of 160 MeV represents a fundamental limit to radiation resulting from electromagnetic particle acceleration in one-zone ideal plasmas. In magnetic reconnection, however, particle acceleration and radiation are decoupled because the electric field is larger than the magnetic field in the diffusion region. We carry out two-dimensional particle-in-cell simulations to determine the extent to which magnetic reconnection can produce synchrotron radiation above the burnoff limit. We use the test particle comparison (TPC) method to isolate the effects of cooling by comparing the trajectories and acceleration efficiencies of test particles incident on such a reconnection region with and without cooling them. We find that the cooled and uncooled particle trajectories are typically similar during acceleration in the reconnection region, and derive an effective limit on particle acceleration that is inversely proportional to the average magnetic field experienced by the particle during acceleration. Using the calculated distribution of this average magnetic field as a function of uncooled final particle energy, we find analytically that cooling does not affect power-law particle energy spectra except at energies far above the synchrotron burnoff limit. Finally, we compare fully cooled and uncooled simulations of reconnection, confirming that the synchrotron burnoff limit does not produce a cutoff in the particle energy spectrum. Our results indicate that the TPC method accurately predicts the effects of cooling on particle acceleration in relativistic reconnection, and that, even far above the burnoff limit, the synchrotron energy of radiation produced in reconnection is not limited by cooling.

  16. Evaluating Attenuation of Vibration Response using Particle Impact Damping for a Range of Equipment Assemblies

    Science.gov (United States)

    Knight, Brent; Parsons, David; Smith, Andrew; Hunt, Ron; LaVerde, Bruce; Towner, Robert; Craigmyle, Ben

    2013-01-01

    Particle dampers provide a mechanism for diverting energy away from resonant structural vibrations. This experimental study provides data from a series of acoustically excited tests to determine the effectiveness of these dampers for equipment mounted to a curved orthogrid panel for a launch vehicle application. Vibration attenuation trends are examined for variations in particle damper fill level, component mass, and excitation energy. A significant response reduction at the component level was achieved, suggesting that comparatively small, strategically placed, particle damper devices might be advantageously used in launch vehicle design. These test results were compared to baseline acoustic response tests without particle damping devices, over a range of isolation and damping parameters. Instrumentation consisting of accelerometers, microphones, and still photography data will be collected to correlate with the analytical results.

  17. Phenomenological and Astro-particle analysis of light dark matter particles

    International Nuclear Information System (INIS)

    Albornoz Vasquez, D.

    2011-09-01

    The nature of Dark Matter (DM) is still unveiled. Experimental efforts aiming to detect the Dark Matter have shown a great progress in the last decade. This work is devoted to the phenomenological and astro-particle studies of Dark Matter candidates of supersymmetric nature - the neutralino - and beyond - scalar particles. The former, in the (1-100) GeV mass range, is currently being tested by the Large Hadron Collider, direct detection and indirect detection experiments; this work shows that the interplay between experimental techniques is a decisive tool to thoroughly search for theoretical predictions. The latter is a non-standard candidate as light as 1 MeV which could be copiously produced at the Large Hadron Collider and, at the same time, it could explain other phenomena such as neutrino masses and/or the 511 keV line from the galactic center of the Milky Way. We start by describing the DM problem in Part I, where we give a review for evidence of the existence of DM, we set the cosmological framework in which we work and describe the history of DM from the Early Universe (EU), to the formation of structure and up to the current distribution of the DM in haloes. Then, in Part II, we go through the important Cosmological, Astro-particle and Particle Physics constraints to particle DM candidates and subsequently introduce models providing relatively light DM candidates, models of standard supersymmetric nature such as the Minimal Supersymmetric Standard Model (MSSM) and the Next-to-MSSM (NMSSM) with neutralino DM, and beyond N=1 SUSY in a light scalar DM scenario inspired in N=2 SUSY. Finally, in Part III we present the findings of the investigations carried out: we describe a numerical tool developed to scan the multidimensional supersymmetric parameter space, then we present an application of this tool to the search of light neutralino configurations in the MSSM and NMSSM as well as an application to the search for neutralino DM in directional detectors, and

  18. Mapping fracture flow paths with a nanoscale zero-valent iron tracer test and a flowmeter test

    Science.gov (United States)

    Chuang, Po-Yu; Chia, Yeeping; Chiu, Yung-Chia; Teng, Mao-Hua; Liou, Sofia Ya Hsuan

    2018-02-01

    The detection of preferential flow paths and the characterization of their hydraulic properties are important for the development of hydrogeological conceptual models in fractured-rock aquifers. In this study, nanoscale zero-valent iron (nZVI) particles were used as tracers to characterize fracture connectivity between two boreholes in fractured rock. A magnet array was installed vertically in the observation well to attract arriving nZVI particles and identify the location of the incoming tracer. Heat-pulse flowmeter tests were conducted to delineate the permeable fractures in the two wells for the design of the tracer test. The nZVI slurry was released in the screened injection well. The arrival of the slurry in the observation well was detected by an increase in electrical conductivity, while the depth of the connected fracture was identified by the distribution of nZVI particles attracted to the magnet array. The position where the maximum weight of attracted nZVI particles was observed coincides with the depth of a permeable fracture zone delineated by the heat-pulse flowmeter. In addition, a saline tracer test produced comparable results with the nZVI tracer test. Numerical simulation was performed using MODFLOW with MT3DMS to estimate the hydraulic properties of the connected fracture zones between the two wells. The study results indicate that the nZVI particle could be a promising tracer for the characterization of flow paths in fractured rock.

  19. Thermo-mechanical characterization of siliconized E-glass fiber/hematite particles reinforced epoxy resin hybrid composite

    Energy Technology Data Exchange (ETDEWEB)

    Arun Prakash, V.R., E-mail: vinprakash101@gmail.com; Rajadurai, A., E-mail: rajadurai@annauniv.edu.in

    2016-10-30

    Highlights: • Particles dimension have reduced using Ball milling process. • Importance of surface modification was explored. • Surface modification has been done to improve adhesion of fiber/particles with epoxy. • Mechanical properties has been increased by adding modified fiber and particles. • Thermal properties have been increased. - Abstract: In this present work hybrid polymer (epoxy) matrix composite has been strengthened with surface modified E-glass fiber and iron(III) oxide particles with varying size. The particle sizes of 200 nm and <100 nm has been prepared by high energy ball milling and sol-gel methods respectively. To enhance better dispersion of particles and improve adhesion of fibers and fillers with epoxy matrix surface modification process has been done on both fiber and filler by an amino functional silane 3-Aminopropyltrimethoxysilane (APTMS). Crystalline and functional groups of siliconized iron(III) oxide particles were characterized by XRD and FTIR spectroscopy analysis. Fixed quantity of surface treated 15 vol% E-glass fiber was laid along with 0.5 and 1.0 vol% of iron(III) oxide particles into the matrix to fabricate hybrid composites. The composites were cured by an aliphatic hardener Triethylenetetramine (TETA). Effectiveness of surface modified particles and fibers addition into the resin matrix were revealed by mechanical testing like tensile testing, flexural testing, impact testing, inter laminar shear strength and hardness. Thermal behavior of composites was evaluated by TGA, DSC and thermal conductivity (Lee’s disc). The scanning electron microscopy was employed to found shape and size of iron(III) oxide particles adhesion quality of fiber with epoxy matrix. Good dispersion of fillers in matrix was achieved with surface modifier APTMS. Tensile, flexural, impact and inter laminar shear strength of composites was improved by reinforcing surface modified fiber and filler. Thermal stability of epoxy resin was improved

  20. Modeling of dilute and dense dispersed fluid-particle flow

    Energy Technology Data Exchange (ETDEWEB)

    Laux, Harald

    1998-08-01

    A general two-fluid model is derived and applied in CFD computations to various test cases of important industrial multiphase flows. It is general in the sense of its applicability to dilute and dense dispersed fluid-particle flows. The model is limited to isothermal flow without mass transfer and only one particle phase is described. The instantaneous fluid phase equations, including the phase interaction terms, are derived from a volume averaging technique, and the instantaneous particle phase equations are derived from the kinetic theory of granular material. Whereas the averaging procedure, the treatment of the interaction terms, and the kinetic theory approach have been reported in literature prior to this work the combination of the approaches is new. The resulting equations are derived without ambiguity in the interpretation of the particle phase pressure (equation-of-state of particle phase). The basic modeling for the particle phase is improved in two steps. Because in the basic modeling only stresses due to kinetic and collisional interactions are included, a simple model for an effective viscosity is developed in order to allow also frictional stresses within the particle phase. Moreover, turbulent stresses and turbulent dispersion of particles play often an important role for the transport processes. Therefore in a second step, a two-equation turbulence model for both fluid and particle phase turbulence is derived by applying the phasic average to the instantaneous equations. The resulting k-{epsilon}-k{sup d}-{epsilon}{sup d} model is new. Mathematical closure is attempted such that the resulting set of equations is valid for both dilute arid dense flows. During the development of the closure relations a clear distinction is made between granular or ''viscous'' microscale fluctuations and turbulent macro scale fluctuations (true particle turbulence) within the particle phase. The set of governing equations is discretized by using a finite volume method

  1. Modeling of dilute and dense dispersed fluid-particle flow

    Energy Technology Data Exchange (ETDEWEB)

    Laux, Harald

    1998-08-01

    A general two-fluid model is derived and applied in CFD computations to various test cases of important industrial multiphase flows. It is general in the sense of its applicability to dilute and dense dispersed fluid-particle flows. The model is limited to isothermal flow without mass transfer and only one particle phase is described. The instantaneous fluid phase equations, including the phase interaction terms, are derived from a volume averaging technique, and the instantaneous particle phase equations are derived from the kinetic theory of granular material. Whereas the averaging procedure, the treatment of the interaction terms, and the kinetic theory approach have been reported in literature prior to this work the combination of the approaches is new. The resulting equations are derived without ambiguity in the interpretation of the particle phase pressure (equation-of-state of particle phase). The basic modeling for the particle phase is improved in two steps. Because in the basic modeling only stresses due to kinetic and collisional interactions are included, a simple model for an effective viscosity is developed in order to allow also frictional stresses within the particle phase. Moreover, turbulent stresses and turbulent dispersion of particles play often an important role for the transport processes. Therefore in a second step, a two-equation turbulence model for both fluid and particle phase turbulence is derived by applying the phasic average to the instantaneous equations. The resulting k-{epsilon}-k{sup d}-{epsilon}{sup d} model is new. Mathematical closure is attempted such that the resulting set of equations is valid for both dilute arid dense flows. During the development of the closure relations a clear distinction is made between granular or ''viscous'' microscale fluctuations and turbulent macro scale fluctuations (true particle turbulence) within the particle phase. The set of governing equations is discretized by using a

  2. Comment on α-particle diagnostics

    International Nuclear Information System (INIS)

    Sasao, M.

    1982-01-01

    The problems of the alpha-particle diagnostics using neutral atom doping beam were investigated. It might be sufficient to use the beam with the velocity of 0.8 v(α) in order to measure a wide range of the alpha particle velocity spectra. The required beam intensity may be 10 mA, if the neutral He fraction is large enough. The cross sections of neutralization with large neutral He fraction in various gases must be measured. The precise calculation of beam dynamics must be investigated. The test experiment in D-D plasma may be possible and useful. At present, in Japan, the negative ion sources of He are under development. The measurement of the cross sections is in progress. (Kato, T.)

  3. Particle accelerators inside spinning black holes.

    Science.gov (United States)

    Lake, Kayll

    2010-05-28

    On the basis of the Kerr metric as a model for a spinning black hole accreting test particles from rest at infinity, I show that the center-of-mass energy for a pair of colliding particles is generically divergent at the inner horizon. This shows not only that classical black holes are internally unstable, but also that Planck-scale physics is a characteristic feature within black holes at scales much larger that the Planck length. The novel feature of the divergence discussed here is that the phenomenon is present only for black holes with rotation, and in this sense it is distinct from the well-known Cauchy horizon instability.

  4. Effects of temperature and particle size on deposition in land based turbines - article no. 051503

    Energy Technology Data Exchange (ETDEWEB)

    Crosby, J.M.; Lewis, S.; Bons, J.P.; Ai, W.G.; Fletcher, T.H. [Brigham Young University, Provo, UT (United States). Dept. for Mechanical Engineering

    2008-09-15

    Four series of tests were performed in an accelerated deposition test facility to study the independent effects of particle size, gas temperature, and metal temperature on ash deposits from two candidate power turbine synfuels (coal and petcoke). The facility matches the gas temperature and velocity of modern first stage high pressure turbine vanes while accelerating the deposition process. Particle size was found to have a significant effect on capture efficiency with larger particles causing significant thermal barrier coating (TBC) spallation during a 4 h accelerated test. In the second series of tests, particle deposition rate was found to decrease with decreasing gas temperature. The threshold gas temperature for deposition was approximately 960{sup o}C. In the third and fourth test series, impingement cooling was applied to the back side of the target coupon to simulate internal vane cooling. Capture efficiency was reduced with increasing mass flow of coolant air; however, at low levels of cooling, the deposits attached more tenaciously to the TBC layer. Postexposure analyses of the third test series (scanning electron microscopy and X-ray spectroscopy) show decreasing TBC damage with increased cooling levels.

  5. Particle production in heavy ion collisions

    International Nuclear Information System (INIS)

    Braun-Munzinger, P.; Redlich, K.; Wroclaw Univ.; Stachel, J.

    2003-04-01

    The status of thermal model descriptions of particle production in heavy ion collisions is presented. We discuss the formulation of statistical models with different implementation of the conservation laws and indicate their applicability in heavy ion and elementary particle collisions. We analyze experimental data on hadronic abundances obtained in ultra-relativistic heavy ion collisions, in a very broad energy range starting from RHIC/BNL (√(s) = 200 A GeV), SPS/CERN (√(s) ≅ 20 A GeV) up to AGS/BNL (√(s) ≅ 5 A GeV) and SIS/GSI (√(s) ≅ 2 A GeV) to test equilibration of the fireball created in the collision. We argue that the statistical approach provides a very satisfactory description of experimental data covering this wide energy range. Any deviations of the model predictions from the data are indicated. We discuss the unified description of particle chemical freeze-out and the excitation functions of different particle species. At SPS and RHIC energy the relation of freeze-out parameters with the QCD phase boundary is analyzed. Furthermore, the application of the extended statistical model to quantitative understanding of open and hidden charm hadron yields is considered. (orig.)

  6. Characterizing uranium oxide reference particles for isotopic abundances and uranium mass by single particle isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Kraiem, M.; Richter, S.; Erdmann, N.; Kühn, H.; Hedberg, M.; Aregbe, Y.

    2012-01-01

    Highlights: ► A method to quantify the U mass in single micron particles by ID-TIMS was developed. ► Well-characterized monodisperse U-oxide particles produced by an aerosol generator were used. ► A linear correlation between the mass of U and the volume of particle(s) was found. ► The method developed is suitable for determining the amount of U in a particulate reference material. - Abstract: Uranium and plutonium particulate test materials are becoming increasingly important as the reliability of measurement results has to be demonstrated to regulatory bodies responsible for maintaining effective nuclear safeguards. In order to address this issue, the Institute for Reference Materials and Measurements (IRMM) in collaboration with the Institute for Transuranium Elements (ITU) has initiated a study to investigate the feasibility of preparing and characterizing a uranium particle reference material for nuclear safeguards, which is finally certified for isotopic abundances and for the uranium mass per particle. Such control particles are specifically required to evaluate responses of instruments based on mass spectrometric detection (e.g. SIMS, TIMS, LA-ICPMS) and to help ensuring the reliability and comparability of measurement results worldwide. In this paper, a methodology is described which allows quantifying the uranium mass in single micron particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS). This methodology is characterized by substantial improvements recently achieved at IRMM in terms of sensitivity and measurement accuracy in the field of uranium particle analysis by TIMS. The use of monodisperse uranium oxide particles prepared using an aerosol generation technique developed at ITU, which is capable of producing particles of well-characterized size and isotopic composition was exploited. The evidence of a straightforward correlation between the particle volume and the mass of uranium was demonstrated in this study

  7. Role of hydrotreating products in deposition of fine particles in reactors

    Energy Technology Data Exchange (ETDEWEB)

    Wang, S.; Chung, K.; Gray, M.R. [University of Alberta, Edmonton, AB (Canada). Dept. of Chemical and Materials Engineering

    2001-06-11

    Hydrotreating reactions may affect the deposition of fine particles, which can eventually lead to reactor plugging. The deposition of fine particles from gas oil was measured in an internally recirculating reactor at 375{degree}C under hydrogen. H{sub 2}S from hydrodesulfurization would convert corrosion products to metal sulfides. Iron sulfide deposited rapidly in the packed bed because the mineral surface did not retain a stabilizing layer of asphaltenic material. Addition of water, to test the role of hydrodeoxygenation, doubled the deposition of clay particles by reducing the surface coating of organic material. Neither ammonia or quinoline had any effect on particle deposition, therefore, hydrodenitrogenation did not affect particle behavior. 16 refs., 4 figs., 3 tabs.

  8. Review of particle properties. Particle Data Group

    International Nuclear Information System (INIS)

    1978-04-01

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

  9. Occurrence of particle debris field during focused Ga ion beam milling of glassy carbon

    Energy Technology Data Exchange (ETDEWEB)

    Hu Qin [Centre for Industrial Photonics, Institute for Manufacturing, Department of Engineering, University of Cambridge, Alan Reece Building, 17 Charles Babbage Road, Cambridge, CB3 0FS (United Kingdom); O' Neill, William, E-mail: wo207@eng.cam.ac.uk [Centre for Industrial Photonics, Institute for Manufacturing, Department of Engineering, University of Cambridge, Alan Reece Building, 17 Charles Babbage Road, Cambridge, CB3 0FS (United Kingdom)

    2010-08-01

    To explore the machining characteristics of glassy carbon by focused ion beam (FIB), particles induced by FIB milling on glassy carbon have been studied in the current work. Nano-sized particles in the range of tens of nanometers up to 400 nm can often be found around the area subject to FIB milling. Two ion beam scanning modes - slow single scan and fast repetitive scan - have been tested. Fewer particles are found in single patterns milled in fast repetitive scan mode. For a group of test patterns milled in a sequence, it was found that a greater number of particles were deposited around sites machined early in the sequence. In situ EDX analysis of the particles showed that they were composed of C and Ga. The formation of particles is related to the debris generated at the surrounding areas, the low melting point of gallium used as FIB ion source and the high contact angle of gallium on glassy carbon induces de-wetting of Ga and the subsequent formation of Ga particles. Ultrasonic cleaning can remove over 98% of visible particles. The surface roughness (R{sub a}) of FIB milled areas after cleaning is less than 2 nm.

  10. Occurrence of particle debris field during focused Ga ion beam milling of glassy carbon

    International Nuclear Information System (INIS)

    Hu Qin; O'Neill, William

    2010-01-01

    To explore the machining characteristics of glassy carbon by focused ion beam (FIB), particles induced by FIB milling on glassy carbon have been studied in the current work. Nano-sized particles in the range of tens of nanometers up to 400 nm can often be found around the area subject to FIB milling. Two ion beam scanning modes - slow single scan and fast repetitive scan - have been tested. Fewer particles are found in single patterns milled in fast repetitive scan mode. For a group of test patterns milled in a sequence, it was found that a greater number of particles were deposited around sites machined early in the sequence. In situ EDX analysis of the particles showed that they were composed of C and Ga. The formation of particles is related to the debris generated at the surrounding areas, the low melting point of gallium used as FIB ion source and the high contact angle of gallium on glassy carbon induces de-wetting of Ga and the subsequent formation of Ga particles. Ultrasonic cleaning can remove over 98% of visible particles. The surface roughness (R a ) of FIB milled areas after cleaning is less than 2 nm.

  11. An efficient multiple particle filter based on the variational Bayesian approach

    KAUST Repository

    Ait-El-Fquih, Boujemaa

    2015-12-07

    This paper addresses the filtering problem in large-dimensional systems, in which conventional particle filters (PFs) remain computationally prohibitive owing to the large number of particles needed to obtain reasonable performances. To overcome this drawback, a class of multiple particle filters (MPFs) has been recently introduced in which the state-space is split into low-dimensional subspaces, and then a separate PF is applied to each subspace. In this paper, we adopt the variational Bayesian (VB) approach to propose a new MPF, the VBMPF. The proposed filter is computationally more efficient since the propagation of each particle requires generating one (new) particle only, while in the standard MPFs a set of (children) particles needs to be generated. In a numerical test, the proposed VBMPF behaves better than the PF and MPF.

  12. Particle acceleration in solar active regions being in the state of self-organized criticality.

    Science.gov (United States)

    Vlahos, Loukas

    We review the recent observational results on flare initiation and particle acceleration in solar active regions. Elaborating a statistical approach to describe the spatiotemporally intermittent electric field structures formed inside a flaring solar active region, we investigate the efficiency of such structures in accelerating charged particles (electrons and protons). The large-scale magnetic configuration in the solar atmosphere responds to the strong turbulent flows that convey perturbations across the active region by initiating avalanche-type processes. The resulting unstable structures correspond to small-scale dissipation regions hosting strong electric fields. Previous research on particle acceleration in strongly turbulent plasmas provides a general framework for addressing such a problem. This framework combines various electromagnetic field configurations obtained by magnetohydrodynamical (MHD) or cellular automata (CA) simulations, or by employing a statistical description of the field’s strength and configuration with test particle simulations. We work on data-driven 3D magnetic field extrapolations, based on a self-organized criticality models (SOC). A relativistic test-particle simulation traces each particle’s guiding center within these configurations. Using the simulated particle-energy distributions we test our results against observations, in the framework of the collisional thick target model (CTTM) of solar hard X-ray (HXR) emission and compare our results with the current observations.

  13. The Effects of Fe-Particles on the Tensile Properties of Al-Si-Cu Alloys

    Directory of Open Access Journals (Sweden)

    Anton Bjurenstedt

    2016-12-01

    Full Text Available The effect of Fe-rich particles has been a topic for discussion in the aluminum casting industry because of the negative impact they exert on the mechanical properties. However, there are still contradictions on the effects of various morphologies of Fe-particles. In this study, microstructural characterization of tensile tested samples has been performed to reveal how unmodified and modified Fe-rich particles impact on the tensile behavior. Analysis of additions of Fe modifiers such as Mn and Cr, showed higher amounts of primary Fe-rich particles (sludge with increased porosity and, as result, degraded tensile properties. From the fracture analysis of tensile tested hot isostatic pressed (HIPed samples it could be concluded that the mechanical properties were mainly governed by the Fe-rich particles, which were fracturing through cleavage, not by the porosity.

  14. Advanced visualization technology for terascale particle accelerator simulations

    International Nuclear Information System (INIS)

    Ma, K-L; Schussman, G.; Wilson, B.; Ko, K.; Qiang, J.; Ryne, R.

    2002-01-01

    This paper presents two new hardware-assisted rendering techniques developed for interactive visualization of the terascale data generated from numerical modeling of next generation accelerator designs. The first technique, based on a hybrid rendering approach, makes possible interactive exploration of large-scale particle data from particle beam dynamics modeling. The second technique, based on a compact texture-enhanced representation, exploits the advanced features of commodity graphics cards to achieve perceptually effective visualization of the very dense and complex electromagnetic fields produced from the modeling of reflection and transmission properties of open structures in an accelerator design. Because of the collaborative nature of the overall accelerator modeling project, the visualization technology developed is for both desktop and remote visualization settings. We have tested the techniques using both time varying particle data sets containing up to one billion particle s per time step and electromagnetic field data sets with millions of mesh elements

  15. Multimedia transport of particle-bound organics: benzo(a)pyrene test case

    Energy Technology Data Exchange (ETDEWEB)

    Ryan, P A; Cohen, Y

    1986-01-01

    A screening multimedia-compartmental (MCM) modeling approach is presented for predicting the distribution of particle-bound pollutants within an environment consisting of the atmosphere, surface water, and surface soil compartments. An MCM model was used to simulate the dynamic distribution of Benzo(a)Pyrene (B(a)P) for a study region located in southeast Ohio. The model incorporates theoretical estimates of the dry deposition velocity and a new semi-empirical model for rain scavenging of B(a)P. The predicted concentrations of B(a)P compared favorably with available field data.

  16. Irradiation of single cells with individual high-LET particles

    International Nuclear Information System (INIS)

    Nelson, J.M.; Braby, L.A.

    1993-01-01

    The dose-limiting normal tissue of concern when irradiating head and neck lesions is often the vascular endothelium within the treatment field. Consequently, the response of capillary endothelial cells exposed to moderate doses of high LET particles is essential for establishing exposure limits for neutron-capture therapy. In an effort to characterize the high-LET radiation biology of cultured endothelial cells, the authors are attempting to measure cellular response to single particles. The single-particle irradiation apparatus, described below, allows them to expose individual cells to known numbers of high-LET particles and follow these cells for extended periods, in order to assess the impact of individual particles on cell growth kinetics. Preliminary cell irradiation experiments have revealed complications related to the smooth and efficient operation of the equipment; these are being resolved. Therefore, the following paragraphs deal primarily with the manner by which high LET particles deposit energy, the requirements for single-cell irradiation, construction and assembly of such apparatus, and testing of experimental procedures, rather than with the radiation biology of endothelial cells

  17. Dynamics of particles accelerated by head-on collisions of two magnetized plasma shocks

    Science.gov (United States)

    Takeuchi, Satoshi

    2018-02-01

    A kinetic model of the head-on collision of two magnetized plasma shocks is analyzed theoretically and in numerical calculations. When two plasmas with anti-parallel magnetic fields collide, they generate magnetic reconnection and form a motional electric field at the front of the collision region. This field accelerates the particles sandwiched between both shock fronts to extremely high energy. As they accelerate, the particles are bent by the transverse magnetic field crossing the magnetic neutral sheet, and their energy gains are reduced. In the numerical calculations, the dynamics of many test particles were modeled through the relativistic equations of motion. The attainable energy gain was obtained by multiplying three parameters: the propagation speed of the shock, the magnitude of the magnetic field, and the acceleration time of the test particle. This mechanism for generating high-energy particles is applicable over a wide range of spatial scales, from laboratory to interstellar plasmas.

  18. High Temperature Falling Particle Receiver (2012 - 2016) - Final DOE Report

    Energy Technology Data Exchange (ETDEWEB)

    Ho, Clifford K. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2016-04-15

    The objective of this work was to advance falling particle receiver designs for concentrating solar power applications that will enable higher temperatures (>700 °C) and greater power-cycle efficiencies (≥50% thermal-to-electric). Modeling, design, and testing of components in Phases 1 and 2 led to the successful on-sun demonstration in Phase 3 of the world’s first continuously recirculating high-temperature 1 MWt falling particle receiver that achieved >700 °C particle outlet temperatures at mass flow rates ranging from 1 – 7 kg/s.

  19. Two-dimensional position sensitive silicon photodiode as a charged particle detector

    International Nuclear Information System (INIS)

    Kovacevic, K.; Zadro, M.

    1999-01-01

    A two-dimensional position sensitive silicon photodiode has been tested for measurement of position and energy of charged particles. Position nonlinearity and resolution, as well as energy resolution and ballistic deficit were measured for 5.486 MeV α-particles. The results obtained for different pulse shaping time constants are presented

  20. Effect of indoor-generated airborne particles on radon progeny dynamics

    Energy Technology Data Exchange (ETDEWEB)

    Trassierra, C. Vargas [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Stabile, L., E-mail: l.stabile@unicas.it [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); Cardellini, F.; Morawska, L. [National Institute of Ionizing Radiation Metrology (INMRI-ENEA), Rome (Italy); Buonanno, G. [Department of Civil and Mechanical Engineering, University of Cassino and Southern Lazio, Cassino, FR (Italy); International Laboratory for Air Quality and Health, Queensland University of Technology, Brisbane (Australia)

    2016-08-15

    Highlights: • Investigation of the interaction between particles and radon progeny dynamics. • Measurements of particles emitted by different indoor sources. • Tests performed in a controlled radon chamber. • Particle size strongly influences the radon progeny dynamics. • Particle surface area concentration is the key parameter of the radon-particle interaction. - Abstract: In order to investigate the interaction between radon progeny and particles, an experimental campaign was carried out in a radon chamber at the Italian National Institute of Ionizing Radiation Metrology, quantifying the amount of attached and unattached radon daughters present in air, as well as the equilibrium factor in the presence of particles generated through indoor sources. A fixed radon concentration was maintained, while particles were generated using incense sticks, mosquito coils and gas combustion. Aerosols were characterized in terms of particle concentrations and size distributions. Simultaneously, radon concentration and attached/unattached potential alpha energy concentration in the air were continuously monitored by two different devices, based on alpha spectroscopy techniques. The presence of particles was found to affect the attached fraction of radon decay products, in such a way that the particles acted as a sink for radionuclides. In terms of sources which emit large particles (e.g. incense, mosquito coils), which greatly increase particle surface area concentrations, the Equilibrium Factor was found to double with respect to the background level before particle generation sessions. On the contrary, the radon decay product dynamics were not influenced by gas combustion processes, mainly due to the small surface area of the particles emitted.

  1. Particle therapy

    Energy Technology Data Exchange (ETDEWEB)

    Raju, M.R.

    1993-09-01

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

  2. Particle therapy

    International Nuclear Information System (INIS)

    Raju, M.R.

    1993-01-01

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

  3. Non-accelerator particle physics

    International Nuclear Information System (INIS)

    Steinberg, R.I.

    1990-01-01

    The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are currently engaged in construction of the MACRO detector, an Italian-American collaborative research instrument with a total particle acceptance of 10,000 m 2 sr, which will perform a sensitive search for magnetic monopoles using excitation-ionization methods. Other major objective of the MACRO experiment are to search for astrophysical high energy neutrinos expected to be emitted by such objects as Vela X-1, LMC X-4 and SN-1987A and to search for low energy neutrino bursts from gravitational stellar collapse. We are also working on BOREX, a liquid scintillation solar neutrino experiment and GRANDE, a proposed very large area surface detector for astrophysical neutrinos, and on the development of new techniques for liquid scintillation detection

  4. Reconstructing an icosahedral virus from single-particle diffraction experiments

    Science.gov (United States)

    Saldin, D. K.; Poon, H.-C.; Schwander, P.; Uddin, M.; Schmidt, M.

    2011-08-01

    The first experimental data from single-particle scattering experiments from free electron lasers (FELs) are now becoming available. The first such experiments are being performed on relatively large objects such as viruses, which produce relatively low-resolution, low-noise diffraction patterns in so-called ``diffract-and-destroy'' experiments. We describe a very simple test on the angular correlations of measured diffraction data to determine if the scattering is from an icosahedral particle. If this is confirmed, the efficient algorithm proposed can then combine diffraction data from multiple shots of particles in random unknown orientations to generate a full 3D image of the icosahedral particle. We demonstrate this with a simulation for the satellite tobacco necrosis virus (STNV), the atomic coordinates of whose asymmetric unit is given in Protein Data Bank entry 2BUK.

  5. Utilization of surface-treated rubber particles from waste tires

    Energy Technology Data Exchange (ETDEWEB)

    Smith, F.G. [Argonne National Lab., IL (United States). Energy Systems Div.]|[Environmental Technologies Alternatives, Inc., Lima, OH (United States)

    1994-12-01

    During a 12-month program, the author successfully demonstrated commercial applications for surface-treated rubber particles in two major markets: footwear (shoe soles and components) and urethane-foam carpet underlay (padding). In these markets, he has clearly demonstrated the ease of using R-4080 and R-4030 surface-treated rubber particles in existing manufacturing plants and processes and have shown that the material meets or exceeds existing standards for performance, quality, and cost-effectiveness. To produce R-4080 and R-4030, vulcanized rubber, whole-tire material is finely ground to particles of nominal 80 and mesh size respectively. Surface treatment is achieved by reacting these rubber particles with chlorine gas. In this report, the author describes the actual test and evaluations of the participant companies, and identifies other potential end uses.

  6. Damping of Mechanical Waves with Styrene/Butadiene Rubber Filled with Polystyrene Particle: Effects of Particles Size and Wave Frequency

    Directory of Open Access Journals (Sweden)

    M. Haghgo

    2007-08-01

    Full Text Available Utilizing polymeric materials for damping mechanical waves is of great importance in various fields of applications such as military camouflage, prevention of structural vibrational energy transfer, and noise attenuation. This ability originates from segmental dynamics of chain-like polymer molecules. Damping properties of styrene-butadiene rubbercontaining 10 wt% of monosize polystyrene particles with different diameters (from 80 nm to 500 μm was investigated in the frequency range of vibration, sound, and ultrasound via dynamic mechanical thermal analysis, normalsound adsorption test, and ultrasound attenuation coefficient measurement. The obtained results indicated that for different systems, containing different sizes of polystyrene particles, the area under the damping curve does not show significant change comparing to the neat SBR in the frequency range studied. However, addition of polystyrene particles, specifically nanosized particles, resulted in emergence of a secondary glass transition temperature which could be attributed to the modified dynamics of a layer of matrix molecules near the surface of PS particles. In the range of sound frequency, 0.5 to 6.3 kHz, the maximum damping was observed for the system containing polystyrene nanoparticles. However the single damping curve of neat SBR was separated into two or even three distinct curves owing to the presence of the particles. The maximum damping in the ultrasound frequency range was found for the system containing 0.5 mm polystyrene particles. This is attributed to different contributions from matrix chains dynamics and the reflection of mechanical waves from particles-matrix interface at different frequency ranges. On other words, the increase in the glass transition temperature of the elastomeric matrix phase with increasing the mechanical wave frequency causes a reduction in the contribution from matrix chains dynamics while the contribution due to diffraction from dispersed

  7. A method for grindability testing using the Scirocco disperser.

    Science.gov (United States)

    Bonakdar, Tina; Ali, Muzammil; Dogbe, Selasi; Ghadiri, Mojtaba; Tinke, Arjen

    2016-03-30

    In the early stages of development of a new Active Pharmaceutical Ingredient (API), insufficient material quantity is available for addressing processing issues, and it is highly desirable to be able to assess processability issues using the smallest possible powder sample quantity. A good example is milling of new active pharmaceutical ingredients. For particle breakage that is sensitive to strain rate, impact testing is the most appropriate method. However, there is no commercially available single particle impact tester for fine particulate solids. In contrast, dry powder dispersers, such as the Scirocco disperser of the Malvern Mastersizer 2000, are widely available, and can be used for this purpose, provided particle impact velocity is known. However, the distance within which the particles can accelerate before impacting on the bend is very short and different particle sizes accelerate to different velocities before impact. As the breakage is proportional to the square of impact velocity, the interpretation of breakage data is not straightforward and requires an analysis of particle velocity as a function of size, density and shape. We report our work using an integrated experimental and CFD modelling approach to evaluate the suitability of this device as a grindability testing device, with the particle sizing being done immediately following dispersion by laser diffraction. Aspirin, sucrose and α-lactose monohydrate are tested using narrow sieve cuts in order to minimise variations in impact velocity. The tests are carried out at eight different air nozzle pressures. As intuitively expected, smaller particles accelerate faster and impact the wall at a higher velocity compared to the larger particles. However, for a given velocity the extent of breakage of larger particles is larger. Using a numerical simulation based on CFD, the relationship between impact velocity and particle size and density has been established assuming a spherical shape, and using one

  8. Investigations on the magnetization behavior of magnetic composite particles

    Energy Technology Data Exchange (ETDEWEB)

    Eichholz, Christian [Process Research and Chemical Engineering, BASF SE, Ludwigshafen (Germany); Knoll, Johannes, E-mail: johannes.knoll@kit.edu [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany); Lerche, Dietmar [L.U.M. GmbH, Berlin (Germany); Nirschl, Hermann [Institute of Mechanical Engineering and Mechanics, Karlsruhe Institute of Technology, Karlsruhe (Germany)

    2014-11-15

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data.

  9. Investigations on the magnetization behavior of magnetic composite particles

    International Nuclear Information System (INIS)

    Eichholz, Christian; Knoll, Johannes; Lerche, Dietmar; Nirschl, Hermann

    2014-01-01

    In life sciences the application of surface functionalized magnetic composite particles is establishing in diagnostics and in downstream processing of modern biotechnology. These magnetic composite particles consist of non-magnetic material, e.g. polystyrene, which serves as a matrix for the second magnetic component, usually colloidal magnetite. Because of the multitude of magnetic cores these magnetic beads show a complex magnetization behavior which cannot be described with the available approaches for homogeneous magnetic material. Therefore, in this work a new model for the magnetization behavior of magnetic composite particles is developed. By introducing an effective magnetization and considering an overall demagnetization factor the deviation of the demagnetization of homogeneously magnetized particles is taken into account. Calculated and experimental results show a good agreement which allows for the verification of the adapted model of particle magnetization. Besides, a newly developed magnetic analyzing centrifuge is used for the characterization of magnetic composite particle systems. The experimental results, also used for the model verification, give both, information about the magnetic properties and the interaction behavior of particle systems. By adding further components to the particle solution, such as salts or proteins, industrial relevant systems can be reconstructed. The analyzing tool can be used to adapt industrial processes without time-consuming preliminary tests with large samples in the process equipments. - Highlights: • New model for magnetizability calculation of magnetic composite particles. • New method for particle bulk characterization relating to their magnetizability. • Model verification due to experimental data

  10. Single-particle characterization of ice-nucleating particles and ice particle residuals sampled by three different techniques

    Science.gov (United States)

    Worringen, A.; Kandler, K.; Benker, N.; Dirsch, T.; Mertes, S.; Schenk, L.; Kästner, U.; Frank, F.; Nillius, B.; Bundke, U.; Rose, D.; Curtius, J.; Kupiszewski, P.; Weingartner, E.; Vochezer, P.; Schneider, J.; Schmidt, S.; Weinbruch, S.; Ebert, M.

    2015-04-01

    In the present work, three different techniques to separate ice-nucleating particles (INPs) as well as ice particle residuals (IPRs) from non-ice-active particles are compared. The Ice Selective Inlet (ISI) and the Ice Counterflow Virtual Impactor (Ice-CVI) sample ice particles from mixed-phase clouds and allow after evaporation in the instrument for the analysis of the residuals. The Fast Ice Nucleus Chamber (FINCH) coupled with the Ice Nuclei Pumped Counterflow Virtual Impactor (IN-PCVI) provides ice-activating conditions to aerosol particles and extracts the activated particles for analysis. The instruments were run during a joint field campaign which took place in January and February 2013 at the High Alpine Research Station Jungfraujoch (Switzerland). INPs and IPRs were analyzed offline by scanning electron microscopy and energy-dispersive X-ray microanalysis to determine their size, chemical composition and mixing state. Online analysis of the size and chemical composition of INP activated in FINCH was performed by laser ablation mass spectrometry. With all three INP/IPR separation techniques high abundances (median 20-70%) of instrumental contamination artifacts were observed (ISI: Si-O spheres, probably calibration aerosol; Ice-CVI: Al-O particles; FINCH + IN-PCVI: steel particles). After removal of the instrumental contamination particles, silicates, Ca-rich particles, carbonaceous material and metal oxides were the major INP/IPR particle types obtained by all three techniques. In addition, considerable amounts (median abundance mostly a few percent) of soluble material (e.g., sea salt, sulfates) were observed. As these soluble particles are often not expected to act as INP/IPR, we consider them as potential measurement artifacts. Minor types of INP/IPR include soot and Pb-bearing particles. The Pb-bearing particles are mainly present as an internal mixture with other particle types. Most samples showed a maximum of the INP/IPR size distribution at 200

  11. Diamond Particle Detector Properties during High Fluence Material Damage Tests and their Future Applications for Machine Protection in the LHC

    CERN Document Server

    Burkart, F; Borburgh, J; Dehning, B; Di Castro, M; Griesmayer, E; Lechner, A; Lendaro, J; Loprete, F; Losito, R; Montesano, S; Schmidt, R; Wollmann, D; Zerlauth, M

    2013-01-01

    Experience with LHC machine protection (MP) during the last three years of operation shows that the MP systems sufficiently protect the LHC against damage in case of failures leading to beam losses with a time constant exceeding 1ms. An unexpected fast beam loss mechanism, called UFOs [1], was observed, which could potentially quench superconducting magnets. For such fast losses, but also for better understanding of slower losses, an improved understanding of the loss distribution within a bunch train is required [2]. Diamond particle detectors with bunch-by-bunch resolution and high dynamic range have been developed and successfully tested in the LHC and in experiments to quantify the damage limits of LHC components. This paper will focus on experience gained in use of diamond detectors. The properties of these detectors were measured during high-fluence material damage tests in CERN’s Hi-RadMat facility. The results will be discussed and compared to the cross-calibration with FLUKA simulations. Future app...

  12. Lagrangian particle method for compressible fluid dynamics

    Science.gov (United States)

    Samulyak, Roman; Wang, Xingyu; Chen, Hsin-Chiang

    2018-06-01

    A new Lagrangian particle method for solving Euler equations for compressible inviscid fluid or gas flows is proposed. Similar to smoothed particle hydrodynamics (SPH), the method represents fluid cells with Lagrangian particles and is suitable for the simulation of complex free surface/multiphase flows. The main contributions of our method, which is different from SPH in all other aspects, are (a) significant improvement of approximation of differential operators based on a polynomial fit via weighted least squares approximation and the convergence of prescribed order, (b) a second-order particle-based algorithm that reduces to the first-order upwind method at local extremal points, providing accuracy and long term stability, and (c) more accurate resolution of entropy discontinuities and states at free interfaces. While the method is consistent and convergent to a prescribed order, the conservation of momentum and energy is not exact and depends on the convergence order. The method is generalizable to coupled hyperbolic-elliptic systems. Numerical verification tests demonstrating the convergence order are presented as well as examples of complex multiphase flows.

  13. Continuous separation of colloidal particles using dielectrophoresis.

    Science.gov (United States)

    Yunus, Nurul Amziah Md; Nili, Hossein; Green, Nicolas G

    2013-04-01

    Dielectrophoresis is the movement of particles in nonuniform electric fields and has been of interest for application to manipulation and separation at and below the microscale. This technique has the advantages of being noninvasive, nondestructive, and noncontact, with the movement of particle achieved by means of electric fields generated by miniaturized electrodes and microfluidic systems. Although the majority of applications have been above the microscale, there is increasing interest in application to colloidal particles around a micron and smaller. This paper begins with a review of colloidal and nanoscale dielectrophoresis with specific attention paid to separation applications. An innovative design of integrated microelectrode array and its application to flow-through, continuous separation of colloidal particles is then presented. The details of the angled chevron microelectrode array and the test microfluidic system are then discussed. The variation in device operation with applied signal voltage is presented and discussed in terms of separation efficiency, demonstrating 99.9% separation of a mixture of colloidal latex spheres. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. photon-plasma: A modern high-order particle-in-cell code

    International Nuclear Information System (INIS)

    Haugbølle, Troels; Frederiksen, Jacob Trier; Nordlund, Åke

    2013-01-01

    We present the photon-plasma code, a modern high order charge conserving particle-in-cell code for simulating relativistic plasmas. The code is using a high order implicit field solver and a novel high order charge conserving interpolation scheme for particle-to-cell interpolation and charge deposition. It includes powerful diagnostics tools with on-the-fly particle tracking, synthetic spectra integration, 2D volume slicing, and a new method to correctly account for radiative cooling in the simulations. A robust technique for imposing (time-dependent) particle and field fluxes on the boundaries is also presented. Using a hybrid OpenMP and MPI approach, the code scales efficiently from 8 to more than 250.000 cores with almost linear weak scaling on a range of architectures. The code is tested with the classical benchmarks particle heating, cold beam instability, and two-stream instability. We also present particle-in-cell simulations of the Kelvin-Helmholtz instability, and new results on radiative collisionless shocks

  15. Coolability of volumetrically heated particle beds

    Energy Technology Data Exchange (ETDEWEB)

    Rashid, Muhammad

    2017-03-22

    In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al{sub 2}O{sub 3} particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m{sup 2}, polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements

  16. Coolability of volumetrically heated particle beds

    International Nuclear Information System (INIS)

    Rashid, Muhammad

    2017-01-01

    In case of a severe nuclear reactor accident, with loss of coolant, a particle bed may be formed from the fragmentation of the molten core in the residual water at different stages of the accident. To avoid further propagation of the accident and maintain the integrity of the reactor pressure vessel, the decay heat of the particle bed must be removed. To better understand the various thermo-hydraulic processes within such heat-generating particle beds, the existing DEBRIS test facility at IKE has been modified to be able to perform novel boiling, dryout and quenching experiments. The essential experimental data includes the pressure gradients measured by 8 differential pressure transducers along the bed height as a function of liquid and vapour superficial velocities, the determination of local dryout heat fluxes for different system pressures as well as the local temperature distribution measured by a set of 51 thermocouples installed inside the particle bed. The experiments were carried out for two different particle beds: a polydispersed particle bed which consisted of stainless steel balls (2 mm, 3 mm and 6 mm diameters) and an irregular particle bed which consisted of a mixture of steel balls (3 mm and 6 mm) and irregularly shaped Al 2 O 3 particles. Additionally, all experiments were carried out for different flow conditions, such as the reference case of passive 1D top-flooding, 1D bottom flooding (driven by external pumps and different downcomer configurations) and 2D top-/bottom-/lateral flooding with a perforated downcomer. In this work, it has been observed that for both particle beds with downcomer configurations an open downcomer leads to the best coolability (dryout heat flux = 1560 kW/m 2 , polydispersed particle bed, psys = 1 bar) of the particle bed, mainly due to bottom-flow with enhanced natural convection. It has also been shown that a potential lateral flow via a perforation of the downcomer does not bring any further improvements in

  17. Particle physics

    International Nuclear Information System (INIS)

    Kamal, Anwar

    2014-01-01

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

  18. Cosmic rays and tests of fundamental principles

    International Nuclear Information System (INIS)

    Gonzalez-Mestres, Luis

    2011-01-01

    It is now widely acknowledged that cosmic rays experiments can test possible new physics directly generated at the Planck scale or at some other fundamental scale. By studying particle properties at energies far beyond the reach of any man-made accelerator, they can yield unique checks of basic principles. A well-known example is provided by possible tests of special relativity at the highest cosmic-ray energies. But other essential ingredients of standard theories can in principle be tested: quantum mechanics, uncertainty principle, energy and momentum conservation, effective space-time dimensions, hamiltonian and lagrangian formalisms, postulates of cosmology, vacuum dynamics and particle propagation, quark and gluon confinement, elementariness of particles... Standard particle physics or string-like patterns may have a composite origin able to manifest itself through specific cosmic-ray signatures. Ultra-high energy cosmic rays, but also cosmic rays at lower energies, are probes of both 'conventional' and new Physics. Status, prospects, new ideas, and open questions in the field are discussed.

  19. 3D Lagrangian Model of Particle Saltation in an Open Channel Flow with Emphasis on Particle-Particle Collisions

    Science.gov (United States)

    Moreno, P. A.; Bombardelli, F. A.

    2012-12-01

    Particles laying motionless at the bed of rivers, lakes and estuaries can be put into motion when the shear stress exerted by the flow on the particles exceeds the critical shear stress. When these particles start their motion they can either remain suspended by long periods of time (suspended load) or move close to the bed (bed load). Particles are transported as bed load in three different modes: Sliding, rolling and saltation. Saltation is usually described as the bouncing motion of sediment particles in a layer a few particle diameters thick. The amount of particles and the bed-load mode in which they move depend on the particle size and density, and the flow intensity, usually quantified by the shear velocity. The bottom shear stress in natural streams will most likely be large enough to set saltation as the most important bed-load transport mechanism among all three modes. Thus, studying the saltation process is crucial for the overall understanding of bed-load transport. Particularly, numerical simulations of this process have been providing important insight regarding the relative importance of the physical mechanisms involved in it. Several processes occur when particles are saltating near the bed: i) Particles collide with the bed, ii) they "fly" between collisions with the bed, as a result of their interaction with the fluid flow, iii) and they collide among themselves. These processes can be simulated using a three-dimensional Eulerian-Lagrangian model. In order to mimic these processes we have experimented with an averaged turbulent flow field represented by the logarithmic law of the wall, and with a more involved approach in which a computed turbulent velocity field for a flat plate was used as a surrogate of the three-dimensional turbulent conditions present close to stream beds. Since flat-plate and open-channel boundary layers are essentially different, a dynamic similarity analysis was performed showing that the highly-resolved three

  20. Particle density determination of pellets and briquettes

    Energy Technology Data Exchange (ETDEWEB)

    Rabier, Fabienne; Temmerman, Michaeel [Centre wallon de Recherches agronomiques, Departement de Genie rural, CRA-W, Chaussee de Namur, 146, B 5030 Gembloux (Belgium); Boehm, Thorsten; Hartmann, Hans [Technologie und Foerderzentrum fuer Nachwachsende Rohstoffe, TFZ, Schulgasse 18, D 94315 Straubing (Germany); Daugbjerg Jensen, Peter [Forest and Landscape, The Royal Veterinary and Agricultural University, Rolighedsvej 23, DK 1958 Frederiksberg C (Denmark); Rathbauer, Josef [Bundesanstalt fuer Landtechnik, BLT, Rottenhauer Strasse,1 A 3250 Wieselburg (Austria); Carrasco, Juan; Fernandez, Miguel [Centro de investigaciones Energeticas, Medioambientales y Tecnologicas, CIEMAT, Avenida Complutense, 22 E 28040 Madrid (Spain)

    2006-11-15

    Several methods and procedures for the determination of particle density of pellets and briquettes were tested and evaluated. Round robin trials were organized involving five European laboratories, which measured the particle densities of 15 pellet and five briquette types. The test included stereometric methods, methods based on liquid displacement (hydrostatic and buoyancy) applying different procedures and one method based on solid displacement. From the results for both pellets and briquettes, it became clear that the application of a method based on either liquid or solid displacement (only tested on pellet samples) leads to an improved reproducibility compared to a stereometric method. For both, pellets and briquettes, the variability of measurements strongly depends on the fuel type itself. For briquettes, the three methods tested based on liquid displacement lead to similar results. A coating of the samples with paraffin did not improve the repeatability and the reproducibility. Determinations with pellets proved to be most reliable when the buoyancy method was applied using a wetting agent to reduce surface tensions without sample coating. This method gave the best values for repeatability and reproducibility, thus less replications are required to reach a given accuracy level. For wood pellets, the method based on solid displacement gave better values of repeatability, however, this instrument was tested at only one laboratory. (author)