Effect of additional nickel on crystallization degree evolution of expanded graphite during ball-milling and annealing

International Nuclear Information System (INIS)

Wang Liqin; Yue Xueqing; Zhang Fucheng; Zhang Ruijun

2010-01-01

Expanded graphite (EG) and a mixture of EG and nickel (EG-Ni system) were ball-milled and subsequently annealed, respectively. The products were characterized by X-ray diffraction (XRD), Raman spectra and transmission electron microscopy (TEM). After 100 h milling, the average crystallite thickness (L c ) of EG and EG-Ni system deceases from 14.5 to 8.0 and 9.6 nm, respectively, while the interlayer spacing (d 002 ) increases from 0.3341 to 0.3371 and 0.3348 nm, respectively. It can be concluded that ball-milling decreases the crystallization degree of EG, while the additional nickel restrains this process. For the samples ball-milled for 80 h, the disorder parameter I D /(I D + I G ) ratio of EG and EG-Ni system is in the range of 20.7-55.8% and 31.7-45.8%, respectively, implying that the presence of nickel is beneficial to more homogeneous ball-milling of EG. When the samples after ball-milling for 80 h were annealed for 4 h, the average crystallite thickness of EG and EG-Ni system increases from 8.5 to 9.0 nm and from 11.8 to 15.5 nm, respectively. It is deduced that annealing improves the crystallization degree of ball-milled EG, and the additional nickel is helpful for this process.

Nonisothermal nematic liquid crystal flows with the Ball-Majumdar free energy

Czech Academy of Sciences Publication Activity Database

Feireisl, Eduard; Schimperna, G.; Rocca, E.; Zarnescu, A.

2015-01-01

Roč. 194, č. 5 (2015), s. 1269-1299 ISSN 0373-3114 EU Projects: European Commission(XE) 320078 - MATHEF Institutional support: RVO:67985840 Keywords : nematic liquid crystal * Ball-Majumdar free theory * nonisothermal model * existence theorem Subject RIV: BA - General Mathematics Impact factor: 0.861, year: 2015 http://link.springer.com/article/10.1007%2Fs10231-014-0419-1

DARMSTADT: Christoph Schmelzer 80

Energy Technology Data Exchange (ETDEWEB)

Anon.

1989-01-15

On 24 November, after an event at the GSI (Gesellschaft fur Schwerionenforschung) Laboratory, Darmstadt, to mark his 80th birthday, Christoph Schmelzer pushed the button to inject nuclear particles through a new transfer line into GSI's new SIS heavy ion synchrotron, scheduled for commissioning from April. In this way he was able to span two generations of GSI operations — from 1976, his UNILAC (Universal Linear Accelerator) has provided a complete range of nuclear particle beams for experiments.

DARMSTADT: Superconducting electron accelerator in operation

International Nuclear Information System (INIS)

Anon.

1991-01-01

In December, the S-DALINAC superconducting radiofrequency electron accelerator at the Nuclear Physics Institute of Darmstadt's Technische Hochschule was completed. This pioneer continuous-wave (c.w.) machine passed a major milestone several years ago when it accelerated its first low energy electron beam

Measuring the branching fraction of ω→ ηγ with the crystal ball Experiment at MAMI

Energy Technology Data Exchange (ETDEWEB)

Steffen, Oliver; Gradl, Wolfgang [Institut fuer Kernphysik, Johannes Gutenberg-Universitaet Mainz, D-55099 Mainz (Germany); Collaboration: A2-Collaboration

2015-07-01

The Crystal Ball Collaboration uses energy tagged bremstrahlung photons produced from the MAMI electron beam to study photo-induced reactions on nucleons and nuclei. The Crystal Ball/TAPS 4π calorimeter setup is optimized for the detection of neutral final states. Charged particles are identified and measured by the inner detector system. A large data set of photoproduced η{sup p}rime and ω mesons has been obtained during recent data taking periods with the End Point Tagger (E{sub γ}=1.4 to 1.6 GeV) and the liquid hydrogen target. We plan to use this data to measure the branching fraction of the ω→ ηγ decay. Simulation studies for this decay have already started. In this talk we present the current status of the ongoing work and discuss the next steps of the analysis.

Anabaptist Spirituality and the Heidelberg Catechism

NARCIS (Netherlands)

van den Belt, Hendrik; Huijgen, Arnold

2015-01-01

Although the Anabaptists are not explicitly mentioned in the Heidelberg Catechism, it is generally acknowledged that the catechism influenced by the debates with the so-called radical reformation. This paper assesses Zacharias Ursinus’ Commentary on the Heidelberg Catechism and the report of the

Crystal Ball contributions to the 9th international workshop on photon-photon collisions, La Jolla, 23-26 March 1992

International Nuclear Information System (INIS)

Bienlein, J.K.

1992-06-01

This report contains two articles concerning new Crystal Ball data on resonance formation by γγ collisions and the representation of such results by helicity amplitudes. See hints under the relevant topics. (HSI)

the heidelberg catechism: a hidden creedal text and catechetical ...

African Journals Online (AJOL)

until 2002 the Heidelberg Catechism had never been translated into one of the vernacular ... acknowledge the Heidelberg Catechism as one of the confessions of faith ... Also informing us about the reception of the Heidelberg Catechism in. Malawi is ... Murray divided its content into three parts: sin and misery, salvation and.

Compact multiwire proportional chambers and electronics for the crystal ball detector

International Nuclear Information System (INIS)

Gaiser, J.E.; Liberman, A.D.; Rolfe, J.

1978-01-01

A double gap of cylindrical proportional chambers has been designed and built for use with a large solid angle, modular NaI(Tl) array (The Crystal Ball). The chambers are constructed of three coaxial foam-epoxy shells, covered with an aluminum-mylar laminate. One of the high voltage cathodes in each chamber has been photo-etched to produce a pattern of stripes and precise position measurements of tracks passing transverse to the chamber axis are found by pulse height analyzing the shaped and amplified induced strip signals. Performance of the chamber using both the strip signals and the sense wire readout is presented. The design of both the signal handling electronics and the digital portions of the systems is discussed

New Crystal Ball data on resonance formation by γγ-collisions

International Nuclear Information System (INIS)

Bienlein, J.K.

1992-01-01

The Crystal Ball detector at DORIS-II has observed a hitherto unknown (though expected) resonance at 1870 MeV/c 2 in the reaction γγ → ηπ o π o . Decay angular distributions and subsystem invariant masses favor the assignment η 2 (1870), a J PC = 2 -+ resonance. An efficient selection of the reaction γγ → π o π o yielded 7000 events. Angular distributions in narrow mass bins became possible and allowed the decomposition of the cross section into S- and D-wave contributions. Thus an f 0 (1250) resonance was found under the dominating f 2 (1270). The search for the channel γγ →ηη in the same selection yielded only (16 ± 6) events. (orig.)

Anabaptist Spirituality and the Heidelberg Catechism

OpenAIRE

van den Belt, Hendrik; Huijgen, Arnold

2015-01-01

Although the Anabaptists are not explicitly mentioned in the Heidelberg Catechism, it is generally acknowledged that the catechism influenced by the debates with the so-called radical reformation. This paper assesses Zacharias Ursinus’ Commentary on the Heidelberg Catechism and the report of the 1571 Frankenthal disputation in order to get a clearer picture of this influence. It concludes that the implicit polemics against the Anabaptists regard the relationship between the Old and the New Te...

William James and the Heidelberg fiasco.

Science.gov (United States)

Gundlach, Horst

2018-02-01

Urged on by his father to become a physician instead of a painter, William James pursued 3 evasion stratagems. First, to avoid becoming a practitioner, he declared that he wanted to specialize in physiology. Based upon this premise, he left for Germany in the spring of 1867. The second step was giving up general physiology and announcing that he would specialize in the nervous system and psychology. Based upon this premise, he declared that he would go to Heidelberg and study with Helmholtz and Wundt. However, he then deferred going there. When, at last, he was urged by an influential friend of his father's to accompany him to Heidelberg, he employed his default stratagem: He simply fled. He returned home after 3 terms in Europe without enrolling at a single university. There is no evidence that he had learned anything there about psychology or experimental psychology, except, possibly, by reading books. James's "Heidelberg fiasco" was the apogee of his evasion of his father's directive. A dense fog of misinformation surrounds his stay in Heidelberg to this day. By analyzing circumstances and context, this article examines the fiasco and places it in the pattern of his behavior during his stay in Europe. Nevertheless, experiencing this fiasco potentially shaped James's ambivalent attitude toward experimental psychology on a long-term basis. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

PANIC at Heidelberg

Energy Technology Data Exchange (ETDEWEB)

Anon.

1984-12-15

Earlier this year in Heidelberg there was PANIC - short for Particle and Nuclei International Conference. This is the new name which has been adopted for a series which in fact began in 1963, the aim being to cover the common ground between the physics of nuclei and of elementary particles.

The cost system of GSI - heavy ion facility in Darmstadt

International Nuclear Information System (INIS)

1979-01-01

The paper gives an overview about the organization and the research program of the GSI (Heavy Ion Facility in Darmstadt). The cost accounting system is discussed in detail, financing, cost center accounting and cost unit accounting are described. (A.N.)

A look into the Medical and Veterinary Entomology crystal ball.

Science.gov (United States)

Dantas-Torres, F; Cameron, M M; Colwell, D D; Otranto, D

2014-08-01

Medical and Veterinary Entomology (MVE) represents a leading periodical in its field and covers many aspects of the biology and control of insects, ticks, mites and other arthropods of medical and veterinary importance. Since the first issue of the journal, researchers working in both developed and developing countries have published in MVE, with direct impact on current knowledge in the field. An increasing number of articles dealing with the epidemiology and transmission of vector-borne pathogens have been published in MVE, reflecting rapid changes in vector distribution, pathogen transmission and host-arthropod interactions. This article represents a gaze into the crystal ball in which we identify areas of increasing interest, discuss the main changes that have occurred in the epidemiology of parasitic arthropods since the first issue of MVE, and predict the principal scientific topics that might arise in the next 25 years for scientists working in medical and veterinary entomology. © 2014 The Royal Entomological Society.

Studies of η' (ω) mesons with the crystal ball/TAPS setup at MAMI

Energy Technology Data Exchange (ETDEWEB)

Adlarson, Patrik [Institut fuer Kernphysik, Johannes Gutenberg Universitaet, Mainz (Germany); Collaboration: A2-Collaboration

2015-07-01

Precision studies of light meson decays are used to investigate a wide range of topics related to fundamental aspects of hadron physics. In particular, η' decays allow for tests of such diverse topics as ππ scattering lengths, the SU(3) singlet-octet mixing angle, quark mass differences and light-by-light contribution to the anomalous magnetic moment of the muon. Recently, a large statistics sample of η'(ω) mesons have been produced and collected with the Crystal Ball/TAPS setup at MAMI. An overview of the physics motivation, the experimental setup and preliminary results from the ongoing analyses are presented.

Reeducation at Heidelberg University.

Science.gov (United States)

Giles, Geoffrey J.

1997-01-01

Utilizes German archival records to illuminate crucial post-war events at Heidelberg University. The university became the focal point of attempts to define the theoretical and practical meaning of "geistige Umerziehung" (spiritual reeducation). Discusses the conflict between U.S. authorities and such esteemed German scholars as Karl…

Effect of ball mill treatment on kinetics of amorphous Ni78Si10B12 alloy crystallization

International Nuclear Information System (INIS)

Tomilin, I.A.; Mochalova, T.Yu.; Kaloshkin, S.D.; Kostyukovich, T.G.; Lopatina, E.A.

1993-01-01

The effect of the parameters of Ni 78 Si 10 B 12 alloy amorphous strip milling in a ball planetary mill on the stability of powder amorphous state, crytallization kinetics and dispersity is studied by the methods of differential scanning microcaloremetry and X-ray diffraction analysis. Energy intensity of milling conditions is assessed. An increase of input energy results in a decrease of activation energy of powder crystallization. Strip milling parameters which enable to avaintain the amorphous state of the material are determined

Recent Crystal Ball results on resonance formation in photon-photon collisions

International Nuclear Information System (INIS)

Karch, K.H.

1991-04-01

The Crystal Ball detector has been used to analyse the formation of resonances in photon-photon collisions. The π 2 (1670) resonance has been observed in the 3π 0 final state, as well as the η' (958) and X (1900) resonances in the ηπ 0 π 0 final state. The X (1900) decay distributions are consistent with the assumption that it is the J PC = 2 -+ η 2 meson. Preliminary analyses of the 8, 10 and 12γ final states are presented. The tensor meson f 2 (1270) is the most prominent structure in the energy dependence of the total cross section σ (γγ → π 0 π 0 ), but close investigation of the differential cross section indicates the presence of a sizeable S wave contribution. This observation is consistent with a broad scalar meson f 0 (1250), degenerate in mass with the f 2 . Indications for the f 0 (975) mesons have been found, too. (orig.)

Bismuth-ceramic nanocomposites through ball milling and liquid crystal synthetic methods

Science.gov (United States)

Dellinger, Timothy Michael

Three methods were developed for the synthesis of bismuth-ceramic nanocomposites, which are of interest due to possible use as thermoelectric materials. In the first synthetic method, high energy ball milling of bismuth metal with either MgO or SiO2 was found to produce nanostructured bismuth dispersed on a ceramic material. The morphology of the resulting bismuth depended on its wetting behavior with respect to the ceramic: the metal wet the MgO, but did not wet on the SiO2. Differential Scanning Calorimetry measurements on these composites revealed unusual thermal stability, with nanostructure retained after multiple cycles of heating and cooling through the metal's melting point. The second synthesis methodology was based on the use of lyotropic liquid crystals. These mixtures of water and amphiphilic molecules self-assemble to form periodic structures with nanometer-scale hydrophilic and hydrophobic domains. A novel shear mixing methodology was developed for bringing together reactants which were added to the liquid crystals as dissolved salts. The liquid crystals served to mediate synthesis by acting as nanoreactors to confine chemical reactions within the nanoscale domains of the mesophase, and resulted in the production of nanoparticles. By synthesizing lead sulfide (PbS) and bismuth (Bi) particles as proof-of-concept, it was shown that nanoparticle size could be controlled by controlling the dimensionality of the nanoreactors through control of the liquid crystalline phase. Particle size was shown to decrease upon going from three-dimensionally percolating nanoreactors, to two dimensional sheet-like nanoreactors, to one dimensional rod-like nanoreactors. Additionally, particle size could be controlled by varying the precursor salt concentration. Since the nanoparticles did not agglomerate in the liquid crystal immediately after synthesis, bismuth-ceramic nanocomposites could be prepared by synthesizing Bi nanoparticles and mixing in SiO2 particles which

The near-infrared free-electron-laser project at Darmstadt

International Nuclear Information System (INIS)

Aab, V.; Alrutz-Ziemssen, K.; Genz, H.; Graef, H.D.; Richter, A.; Weise, H.

1988-07-01

The superconducting 130 MeV electron accelerator at Darmstadt will be modified for FEL experiments. The FEL project is planned with an electron beam in an energy range from 35 to 50 MeV corresponding to wavelengths from 4.9 to 2.4 μm. The planned FEL setup, a high current injection, the design of a hybrid undulator and the results of simulations of the FEL are presented. (orig.)

Recent developments at the ISOL facility of GSI Darmstadt

CERN Document Server

Roeckl, E; Burkard, K; Döring, J; Grawe, H; Hüller, W; Kirchner, R; Mazzocchi, C; Mukha, I; Plettner, C

2003-01-01

The research programme pursued at the ISOL facility of GSI Darmstadt focuses on the study of decay properties of nuclei along the N congruent with Z line between the double shell closures at sup 5 sup 6 Ni and sup 1 sup 0 sup 0 Sn. In this report, the major scientific achievements obtained in the past two years are reviewed, with particular emphasis being put on the detection techniques.

Resonance formation in γγ-collisions - as observed with the Crystal Ball detector

International Nuclear Information System (INIS)

Bienlein, J.K.

1991-01-01

Analysis of two-photon reactions with the Crystal Ball detector at the DORIS-II e + e - storage ring (E beam = 5 GeV) resulted in a complete set of data on γγ-formation of mesons. The data are best represented by their helicity matrix elements. For isoscalar mesons the mixing of non-strange and strange quark constituents can be derived. A highly efficient selection of the channel γγ → π 0 π 0 yielded 7000 events with (M(π 0 π 0 ) > 800 MeV/c 2 . A partial wave decomposition became possible and showed under the f 2 (1270) a scalar meson resonance f 0 (1250) with 4.0 standard deviations. In the same analysis 23 events of γγ → ηη have been found. (orig.)

Integrative quantification and balancing of contaminant fluxes in urban groundwater, case study Darmstadt; Integrative Quantifizierung und Bilanzierung von Stofffluessen in urbanem Grundwasser am Beispiel Darmstadts

Energy Technology Data Exchange (ETDEWEB)

Beier, M.; Ebhardt, G.; Schiedek, T. [Technische Universitaet Darmstadt, Institut fuer Angewandte Geowissenschaften, Darmstadt (Germany)

2007-09-15

The qualitative and quantitative impact of a city on groundwater is presented in the case study of Darmstadt. The impact of land use on groundwater quality in Darmstadt is higher than the impact of background geological processes. The occurrence of Cl, B and Fe is only influenced by land use, while EC, HCO{sub 3} and PO{sub 4} are controlled by geology and land use. An integrative, spatially differentiating quantification of mass fluxes shows that e. g. Cl and B are introduced from urban sources such as leaking sewers and road salting. Input is highest under industrial areas (Cl 317 mg/d . m{sup 2}, B 0,6 mg/d . m{sup 2}). For N{sub tot} agricultural input (114 mg/d . m{sup 2}) is more important than urban input with a maximum of 14 mg/d . m{sup 2}. Comparing overall urban input with estimated urban input, it can be concluded that there are additional sources for HCO{sub 3}, Ca, Mg, SO{sub 4}, Na, Cl, B and NO{sub 3}, which are not included in the estimated input (e. g. geogenic sources, fill material, industrial sources and degradation processes). PO{sub 4} and N{sub tot} on the other hand are being degraded and COD is consumed. A decrease of concentrations downstream from the city can be ascribed to diving plumes. (orig.) [German] Die qualitativen und quantitativen Einfluesse einer Stadt auf das Grundwasser werden am Beispiel Darmstadts beschrieben. Die Landnutzung hat in Darmstadt einen staerkeren Einfluss auf die Grundwasserqualitaet als die Geologie. Cl, B und Fe sind nur von der Nutzung abhaengig, waehrend Lf, HCO{sub 3} und PO{sub 4} von Geologie und Nutzung beeinflusst werden. Eine integrative, raeumlich differenzierende Quantifizierung der Massenfluesse zeigt, dass z. B. Cl und B aus urbanen Quellen wie Abwasserexfiltration und Streusalz eingetragen werden. Die groessten Eintraege erfolgen unter Industrieflaechen (Cl 317 mg/d . m{sup 2}, B 0,6 mg/d . m{sup 2}). Fuer N{sub ges} ist der landwirtschaftliche Eintrag mit bis zu 114 mg/d . m{sup 2} von

Design and performance of a modularized NaI(Tl) detector (the crystal ball prototype)

International Nuclear Information System (INIS)

Chan, Y.; Partridge, R.A.; Peck, C.W.

1977-01-01

A prototype NaI(Tl) detector (the Cluster of 54) of spherical geometry subtending a solid angle of 7.5 percent of 4π at its center, has recently been assembled and tested. This detector consisted of 54 close-packed but optically isolated NaI(Tl) modules and the associated electronic circuitry. The Cluster of 54 is the predecessor of an almost complete spherical detector, the Crystal Ball, which will cover 94 percent of 4π. The latter detector is now under construction and is especially designed for the study of γ-rays produced in electron-positron collisions at colliding beam facilities. The mechanical, optical, and electronic assembly of the prototype system is outlined. Cluster of 54 test data will be presented

"Heidelberg standard examination" and "Heidelberg standard procedures" - Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education.

Science.gov (United States)

Nikendei, C; Ganschow, P; Groener, J B; Huwendiek, S; Köchel, A; Köhl-Hackert, N; Pjontek, R; Rodrian, J; Scheibe, F; Stadler, A-K; Steiner, T; Stiepak, J; Tabatabai, J; Utz, A; Kadmon, M

2016-01-01

The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects "Heidelberg standard examination" and "Heidelberg standard procedures", which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties.

Memory culture in the making: the Heidelberg Catechism in the ...

African Journals Online (AJOL)

This article explores the Heidelberg Catechism in the memory of the Dutch Reformed Church (DRC) between 1862 and 1937, with specific focus on the events of 1862. By making the Heidelberg Catechism the point of focus the article's contribution is not by way of answering the “what happened”-questions related to the ...

Microstructural Evolution, Thermodynamics, and Kinetics of Mo-Tm2O3 Powder Mixtures during Ball Milling

Directory of Open Access Journals (Sweden)

Yong Luo

2016-10-01

Full Text Available The microstructural evolution, thermodynamics, and kinetics of Mo (21 wt % Tm2O3 powder mixtures during ball milling were investigated using X-ray diffraction and transmission electron microscopy. Ball milling induced Tm2O3 to be decomposed and then dissolved into Mo crystal. After 96 h of ball milling, Tm2O3 was dissolved completely and the supersaturated nanocrystalline solid solution of Mo (Tm, O was obtained. The Mo lattice parameter increased with increasing ball-milling time, opposite for the Mo grain size. The size and lattice parameter of Mo grains was about 8 nm and 0.31564 nm after 96 h of ball milling, respectively. Ball milling induced the elements of Mo, Tm, and O to be distributed uniformly in the ball-milled particles. Based on the semi-experimental theory of Miedema, a thermodynamic model was developed to calculate the driving force of phase evolution. There was no chemical driving force to form a crystal solid solution of Tm atoms in Mo crystal or an amorphous phase because the Gibbs free energy for both processes was higher than zero. For Mo (21 wt % Tm2O3, it was mechanical work, not the negative heat of mixing, which provided the driving force to form a supersaturated nanocrystalline Mo (Tm, O solid solution.

Crystallite sizes of LiH before and after ball milling and thermal exposure

International Nuclear Information System (INIS)

Ortiz, Angel L.; Osborn, William; Markmaitree, Tippawan; Shaw, Leon L.

2008-01-01

The powder characteristics of lithium hydride (LiH) as a function of high-energy ball milling condition are systematically investigated via quantitative X-ray diffraction (XRD) analysis. The results obtained from the XRD analysis are compared with those attained from scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area (SSA) analyses. The thermal stability of the ball-milled LiH is also investigated in order to provide physical insights into its cyclic stability in hydrogen sorption and desorption cycles. The results indicate that ball milling is effective in obtaining nano-crystalline LiH powder which is relatively stable with retention of nano-crystals after thermal exposure at 285 deg. C (equivalent to 0.58T m ) for 1 h. The good thermal stability observed is attributed to the presence of many pores in the agglomerates at the ball-milled condition. These pores effectively prevent crystal growth during the thermal exposure

Crystallite sizes of LiH before and after ball milling and thermal exposure

Energy Technology Data Exchange (ETDEWEB)

Ortiz, Angel L. [Departamento de Electronica e Ingenieria Electromecanica, Universidad de Extremadura, Badajoz (Spain); Osborn, William; Markmaitree, Tippawan [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136 Storrs, CT 06269-3136 (United States); Shaw, Leon L. [Department of Chemical, Materials and Biomolecular Engineering, University of Connecticut, 97 North Eagleville Road, U-3136 Storrs, CT 06269-3136 (United States)], E-mail: leon.shaw@uconn.edu

2008-04-24

The powder characteristics of lithium hydride (LiH) as a function of high-energy ball milling condition are systematically investigated via quantitative X-ray diffraction (XRD) analysis. The results obtained from the XRD analysis are compared with those attained from scanning electron microscopy (SEM), transmission electron microscopy (TEM), and specific surface area (SSA) analyses. The thermal stability of the ball-milled LiH is also investigated in order to provide physical insights into its cyclic stability in hydrogen sorption and desorption cycles. The results indicate that ball milling is effective in obtaining nano-crystalline LiH powder which is relatively stable with retention of nano-crystals after thermal exposure at 285 deg. C (equivalent to 0.58T{sub m}) for 1 h. The good thermal stability observed is attributed to the presence of many pores in the agglomerates at the ball-milled condition. These pores effectively prevent crystal growth during the thermal exposure.

Ball Screw Actuator Including a Compliant Ball Screw Stop

Science.gov (United States)

Wingett, Paul T. (Inventor); Hanlon, Casey (Inventor)

2017-01-01

An actuator includes a ball nut, a ball screw, and a ball screw stop. The ball nut is adapted to receive an input torque and in response rotates and supplies a drive force. The ball screw extends through the ball nut and has a first end and a second end. The ball screw receives the drive force from the ball nut and in response selectively translates between a retract position and a extend position. The ball screw stop is mounted on the ball screw proximate the first end to translate therewith. The ball screw stop engages the ball nut when the ball screw is in the extend position, translates, with compliance, a predetermined distance toward the first end upon engaging the ball nut, and prevents further rotation of the ball screw upon translating the predetermined distance.

Sleeping Beauty. Revitalisation of the old indoor swimming pool Heidelberg; Sleeping Beauty. Revitalisierung des alten Hallenbads Heidelberg

Energy Technology Data Exchange (ETDEWEB)

Paul, Jochen

2010-07-01

Since its closure before nearly 30 years due to safety aspects, the monument protected indoor swimming pool in Heidelberg (Federal Republic of Germany) dilapidated appreciably. Only after moving away of the local council from its demand of the wet use, an investor could be found.

“Heidelberg standard examination” and “Heidelberg standard procedures” – Development of faculty-wide standards for physical examination techniques and clinical procedures in undergraduate medical education

Science.gov (United States)

Nikendei, C.; Ganschow, P.; Groener, J. B.; Huwendiek, S.; Köchel, A.; Köhl-Hackert, N.; Pjontek, R.; Rodrian, J.; Scheibe, F.; Stadler, A.-K.; Steiner, T.; Stiepak, J.; Tabatabai, J.; Utz, A.; Kadmon, M.

2016-01-01

The competent physical examination of patients and the safe and professional implementation of clinical procedures constitute essential components of medical practice in nearly all areas of medicine. The central objective of the projects “Heidelberg standard examination” and “Heidelberg standard procedures”, which were initiated by students, was to establish uniform interdisciplinary standards for physical examination and clinical procedures, and to distribute them in coordination with all clinical disciplines at the Heidelberg University Hospital. The presented project report illuminates the background of the initiative and its methodological implementation. Moreover, it describes the multimedia documentation in the form of pocketbooks and a multimedia internet-based platform, as well as the integration into the curriculum. The project presentation aims to provide orientation and action guidelines to facilitate similar processes in other faculties. PMID:27579354

Heidelberg polarized alkali source

International Nuclear Information System (INIS)

Kraemer, D.; Steffens, E.; Jaensch, H.; Philipps Universitaet, Marburg, Germany)

1984-01-01

A new atomic beam type polarized alkali ion source has been installed at Heidelberg. In order to improve the beam polarization considerably optical pumping is applied in combination with an adiabatic medium field transition which results in beams in single hyperfine sublevels. The m state population is determined by laser-induced fluorescence spectroscopy. Highly polarized beams (P/sub s/ > 0.9, s = z, zz) with intensities of 30 to 130 μA can be extracted for Li + and Na + , respectively

A refuge for inorganic chemistry: Bunsen's Heidelberg laboratory.

Science.gov (United States)

Nawa, Christine

2014-05-01

Immediately after its opening in 1855, Bunsen's Heidelberg laboratory became iconic as the most modern and best equipped laboratory in Europe. Although comparatively modest in size, the laboratory's progressive equipment made it a role model for new construction projects in Germany and beyond. In retrospect, it represents an intermediate stage of development between early teaching facilities, such as Liebig's laboratory in Giessen, and the new 'chemistry palaces' that came into existence with Wöhler's Göttingen laboratory of 1860. As a 'transition laboratory,' Bunsen's Heidelberg edifice is of particular historical interest. This paper explores the allocation of spaces to specific procedures and audiences within the laboratory, and the hierarchies and professional rites of passage embedded within it. On this basis, it argues that the laboratory in Heidelberg was tailored to Bunsen's needs in inorganic and physical chemistry and never aimed at a broad-scale representation of chemistry as a whole. On the contrary, it is an example of early specialisation within a chemical laboratory preceding the process of differentiation into chemical sub-disciplines. Finally, it is shown that the relatively small size of this laboratory, and the fact that after ca. 1860 no significant changes were made within the building, are inseparably connected to Bunsen's views on chemistry teaching.

Construction of the Crystal Ball detector system and study of the helicity asymmetry in {gamma}p{yields}p{pi}{sup 0}{pi}{sup 0}; Aufbau des Crystal Ball-Detektorsystems und Untersuchung der Helizitaetsasymmetrie in {gamma} p {yields} p {pi}{sup 0} {pi}{sup 0}

Energy Technology Data Exchange (ETDEWEB)

Krambrich, D.

2007-01-15

Since spring 2004 the Crystal Ball Detector has been used for coincidence experiments probing the structure of the nucleons with real photons at the Mainzer Microtron. A major part of the commissioning, which was the first goal of this work, was the development and implementation of a new system for the Crystal Ball electronics. Components were designed or tested and, if necessary, modified to fit the experimental needs. After the commissioning, the set-up was then used successfully in several pion and eta production experiments for more than 2500 hours of beamtime. The second focus of this dissertation is the first measurement of the beam helicity asymmetry I{sup s}un in photoproduction of two neutral pions. The understanding of the excitation spectra of the nucleon requires experiments using polarised photons and/or polarised targets. Models based on different assumptions do reproduce the quantities measured without polarisation equally well but differ in the prediction of polarisation observables. The determination of more sensitive quantities is therefore mandatory. In contrast to single meson production, an observable appears in double pion production when using circularly polarized photons incident on an unpolarized target. This observable was determined as a function of energy and angle in the reactions {gamma} p {yields} p {pi}{sup 0} {pi}{sup 0} and in {gamma} p {yields} p {pi}{sup +} {pi}{sup -}. The results differ significantly from the model predictions. (orig.)

Construction of the Crystal Ball detector system and study of the helicity asymmetry in γp→pπ0π0

International Nuclear Information System (INIS)

Krambrich, D.

2007-01-01

Since spring 2004 the Crystal Ball Detector has been used for coincidence experiments probing the structure of the nucleons with real photons at the Mainzer Microtron. A major part of the commissioning, which was the first goal of this work, was the development and implementation of a new system for the Crystal Ball electronics. Components were designed or tested and, if necessary, modified to fit the experimental needs. After the commissioning, the set-up was then used successfully in several pion and eta production experiments for more than 2500 hours of beamtime. The second focus of this dissertation is the first measurement of the beam helicity asymmetry I s un in photoproduction of two neutral pions. The understanding of the excitation spectra of the nucleon requires experiments using polarised photons and/or polarised targets. Models based on different assumptions do reproduce the quantities measured without polarisation equally well but differ in the prediction of polarisation observables. The determination of more sensitive quantities is therefore mandatory. In contrast to single meson production, an observable appears in double pion production when using circularly polarized photons incident on an unpolarized target. This observable was determined as a function of energy and angle in the reactions γ p → p π 0 π 0 and in γ p → p π + π - . The results differ significantly from the model predictions. (orig.)

Library goes Anatomy. Anatomische Lehrmedien an der Universitätsbibliothek Heidelberg

OpenAIRE

Gehrlein, S

2014-01-01

Heidelberg University Library is following new paths to optimize the librarian services for medical studies. In close cooperation with the Institute for Anatomy and Cell Biology at Heidelberg University the library is profoundly expanding the anatomical teaching equipment: the virtual dissecting table Anatomage enables medical students to work on life-size, anatomical models in 3D, providing the possibility to prepare for and practice their anatomy lessons. The comprehensive collection of ana...

Darmstadt: Heaviest of them all (so far)

International Nuclear Information System (INIS)

Anon.

1995-01-01

The heaviest nuclei yet, with atomic numbers of 111 and 110, have been synthesized at the GSI (Gesellschaft fur Schwerionenforschung) heavy ion Laboratory, Darmstadt. The breakthrough was made by an international group (GSI/Dubna/ Bratislava/Jyvaeskylae) including Peter Armbruster and Sigurd Hofmann using the SHIP separator for heavy reaction products. This group has already discovered the elements 107, 108 and 109 at GSI. The element 110 experiment initially fused nickel 62 ions accelerated in the GSI UNILAC on a lead 208 target. The resulting nuclei were sorted by SHIP'S velocity filter and an alpha-decay chain could be unambiguously assigned to 269/110. In the Periodic Table, this new nucleus is a heavier cousin of nickel, palladium and platinum. Subsequently, irradiation of bismuth 209 with nickel 64 produced 272/111, exactly on the 25th anniversary of GSI's founding on 17 December 1969.

Academic Training: Physics technologies in medicine

CERN Multimedia

Françoise benz

2005-01-01

24, 25, 26, 27 January 2004-2005 ACADEMIC TRAINING PROGRAMME LECTURE SERIES from 11.00 to 12.00 hrs - Main Auditorium, bldg. 500 Physics technologies in medicine M. GILARDI / Univ. of Milano, I. - U. AMALDI / Univ. of Milano Bicocca and TERA Foundation - M. SCHOLZ / GSI, Darmstadt, D. - O. JÄKEL / Deutsches Krebsforschungszentrum, Heidelberg, D Monday 24 January The frontiers of medical imaging M. GILARDI / Univ. of Milano, I. Tuesday 25 January From the discovery of X-rays to CT/PET diagnostics and conformal radiation therapy U. AMALDI / Univ. of Milano Bicocca and TERA Foundation Wednesday 26 January The increased biological effectiveness of heavy charged particle radiation: from cell culture experiments to biophysics modelling M. SCHOLZ / GSI, Darmstadt, D. Thursday 27 January Medical Physics aspects of radiotherapy with ions O. JÄKEL / Deutsches Krebsforschungszentrum, Heidelberg, D The lectures are open to all those interested, without application. The abstract of the lectures...

Effect of essential oil compound on shedding and colonization of Salmonella enterica serovar Heidelberg in broilers.

Science.gov (United States)

Alali, W Q; Hofacre, C L; Mathis, G F; Faltys, G

2013-03-01

The objectives of this study were to determine the effect of an essential oil blend (EO; carvacrol, thymol, eucalyptol, lemon) administered in drinking water on the performance, mortality, water consumption, pH of crop and ceca, and Salmonella enterica serovar Heidelberg fecal shedding and colonization in broiler birds following Salmonella Heidelberg challenge and feed withdrawal. Chicks were randomly assigned to water treatments containing 0.05, 0.025, or 0.0125% EO or untreated controls. Treatments were administered in drinking water on 0 to 7 and 35 to 42 d. One-half of the chicks were challenged with Salmonella Heidelberg and placed in pens with unchallenged chicks on d 1. Performance, mortality, water consumption, and pH were determined during the 42-d study. Prevalence of Salmonella Heidelberg was determined on drag swabs (0, 14, and 42 d) and in the ceca and crops (42 d). The 0.05% EO administered in drinking water significantly (P water significantly lowered the feed conversion ratio and increased weight gain compared with controls, but did not significantly reduce Salmonella Heidelberg colonization in the crops. The EO in drinking water did not significantly reduce Salmonella Heidelberg colonization in ceca or fecal shedding in broilers. The EO used in the study may control Salmonella Heidelberg contamination in crops of broilers when administered in drinking water and therefore may reduce the potential for cross-contamination of the carcass when the birds are processed.

Ensayo de abrasión de Darmstadt para tuberías de alcantarillado pluvial: revisión de condiciones experimentales

OpenAIRE

Andrés Eduardo Torres Abello; Juan Dionisio Zambrano Ramírez

2009-01-01

El ensayo de abrasión de Darmstadt se ha utilizado principalmente para comparar la abrasión de diferentes tipos de tuberías. Sin embargo, no se han evidenciado claramente aún relaciones entre los resultados obtenidos mediante dicho ensayo y variables como la vida útil de los materiales o la composición del agua transportada. A partir de un montaje experimental, similar al de Darmstadt, se ensayaron tubos de concreto sin revestimiento, haciendo variar las condiciones experimentales. Se observó...

remembering the heidelberg catechism in south africa today?

African Journals Online (AJOL)

deserves to be known and studied. ... In an essay for the recent anniversary publication Power of. Faith: 450 years of the Heidelberg Catechism, Herman Selderhuis refers to Anna Maria van Schurman, the first woman to attend lectures at the.

Library goes Anatomy. Anatomische Lehrmedien an der Universitätsbibliothek Heidelberg

Directory of Open Access Journals (Sweden)

Gehrlein, Sabine

2014-12-01

Full Text Available [english] Heidelberg University Library is following new paths to optimize the librarian services for medical studies. In close cooperation with the Institute for Anatomy and Cell Biology at Heidelberg University the library is profoundly expanding the anatomical teaching equipment: the virtual dissecting table Anatomage enables medical students to work on life-size, anatomical models in 3D, providing the possibility to prepare for and practice their anatomy lessons. The comprehensive collection of anatomical models and plastinates supports students, in particular, in their preparation for the preliminary medical examination.

The Heidelberg Basin Drilling Project - Sedimentology and Stratigraphy of the Quaternary succession

Science.gov (United States)

Ellwanger, Dietrich; Gabriel, Gerald; Hahne, Jürgen; Hoselmann, Christian; Menzies, John; Simon, Theo; Weidenfeller, Michael; Wielandt-Schuster, Ulrike

2010-05-01

Within the context of the Heidelberg Basin Drilling Project (Gabriel et al. 2008), a detailed sediment succession is presented here based upon deep drillings taken at Heidelberg UniNord and Mannheim Käfertal. Sediment structures, and micromorphological and pollen analyses were conducted and used to reconsider some of the climate transitions within the lower Pleistocene. A new and novel scenario is postulated regarding the preservation of Quaternary sediment packages within the Cenozoic Graben environment of the Heidelberg basin. The palynological evidence comprises the periods of warm climate of the Holsteinian (mainly Abies (fir), some Fagus (beech), Pterocarya & Azolla); the Cromerian (Pinus-Picea-QM (pine-spruce-QM)); the Bavelian (Abies, Tsuga (hemlock fir), QM & phases of increased NAP including Pinus); the Waalian (Abies, Tsuga, QM); and the Tiglian (Fagus & early Pleistocene taxa especially Sciadopytis, downward increasing Tertiary taxa). The sediment package was studied both macroscopically and microscopically. Both techniques provide evidence of fluvial, lacustrine and mass movement sedimentary processes. Some include evidence of periglacial processes (silt droplets within fine grained sands indicative of frozen ground conditions). The periglacial structures are often, not always, accompanied by pollen spectra dominated by pine and NAP. E.g. the Tiglian part of the succession shows periglacial sediment structures at its base and top but not in its middle sections. I.e. it appears not as a series of warm and cold phases but rather as a constant warm period with warm-cold-alternations at its bottom and top. All results illustrate sediment preservation in the Heidelberg basin almost throughout the Quaternary. This may be due to tectonic subsidence, but also to compaction by sediment loading of underlying fine sediments (Oligocene to Quaternary) leading to incomplete but virtually continuous sediment preservation (Tanner et al. 2009). References Gabriel, G

Ball clay

Science.gov (United States)

Virta, R.L.

2001-01-01

Part of the 2000 annual review of the industrial minerals sector. A general overview of the ball clay industry is provided. In 2000, sales of ball clay reached record levels, with sanitary ware and tile applications accounting for the largest sales. Ball clay production, consumption, prices, foreign trade, and industry news are summarized. The outlook for the ball clay industry is also outlined.

Report: environmental assessment of Darmstadt (Germany) municipal waste incineration plant.

Science.gov (United States)

Rimaityte, Ingrida; Denafas, Gintaras; Jager, Johannes

2007-04-01

The focus of this study was the emissions from waste incineration plants using Darmstadt (Germany) waste incineration plant as an example. In the study the emissions generated by incineration of the waste were considered using three different approaches. Initially the emissions from the waste incineration plant were assessed as part of the impact of waste management systems on the environment by using a Municipal Solid Waste Management System (MSWMS) assessment tool (also called: LCA-IWM assessment tool). This was followed by a comparison between the optimal waste incineration process and the real situation. Finally a comparison was made between the emissions from the incineration plant and the emissions from a vehicle.

Suppressing Heavy Metal Leaching through Ball Milling of Fly Ash

Directory of Open Access Journals (Sweden)

Zhiliang Chen

2016-07-01

Full Text Available Ball milling is investigated as a method of reducing the leaching concentration (often termed stablilization of heavy metals in municipal solid waste incineration (MSWI fly ash. Three heavy metals (Cu, Cr, Pb loose much of their solubility in leachate by treating fly ash in a planetary ball mill, in which collisions between balls and fly ash drive various physical processes, as well as chemical reactions. The efficiency of stabilization is evaluated by analysing heavy metals in the leachable fraction from treated fly ash. Ball milling reduces the leaching concentration of Cu, Cr, and Pb, and water washing effectively promotes stabilization efficiency by removing soluble salts. Size distribution and morphology of particles were analysed by laser particle diameter analysis and scanning electron microscopy. X-ray diffraction analysis reveals significant reduction of the crystallinity of fly ash by milling. Fly ash particles can be activated through this ball milling, leading to a significant decrease in particle size, a rise in its BET-surface, and turning basic crystals therein into amorphous structures. The dissolution rate of acid buffering materials present in activated particles is enhanced, resulting in a rising pH value of the leachate, reducing the leaching out of some heavy metals.

Ball Nut Preload Diagnosis of the Hollow Ball Screw through Support Vector Machine

Directory of Open Access Journals (Sweden)

Yi-Cheng Huang

2018-01-01

Full Text Available This paper studies the diagnostic results of hollow ball screws with different ball nut preload through the support vector machine (SVM process. The method is testified by considering the use of ball screw pretension and different ball nut preload. SVM was used to discriminate the hollow ball screw preload status through the vibration signals and servo motor current signals. Maximum dynamic preloads of 2%, 4%, and 6% ball screws were predesigned, manufactured, and conducted experimentally. Signal patterns with different preload features are separatedby SVM. The irregularity development of the ball screw driving motion current and rolling balls vibration of the ball screw can be discriminated via SVM based on complexity perception. The experimental results successfully show that the prognostic status of ball nut preload can be envisaged by the proposed methodology. The smart reasoning for the health of the ball screw is available based on classification of SVM. This diagnostic method satisfies the purposes of prognostic effectiveness on knowing the ball nut preload status

Response to Thermal Exposure of Ball-Milled Aluminum-Borax Powder Blends

Science.gov (United States)

Birol, Yucel

2013-04-01

Aluminum-borax powder mixtures were ball milled and heated above 873 K (600 °C) to produce Al-B master alloys. Ball-milled powder blends reveal interpenetrating layers of deformed aluminum and borax grains that are increasingly refined with increasing milling time. Thermal exposure of the ball-milled powder blends facilitates a series of thermite reactions between these layers. Borax, dehydrated during heating, is reduced by Al, and B thus generated reacts with excess Al to produce AlB2 particles dispersed across the aluminum grains starting at 873 K (600 °C). AlB2 particles start to form along the interface of the aluminum and borax layers. Once nucleated, these particles grow readily to become hexagonal-shaped crystals that traverse the aluminum grains with increasing temperatures as evidenced by the increase in the size as well as in the number of the AlB2 particles. Ball milling for 1 hour suffices to achieve a thermite reaction between borax and aluminum. Ball milling further does not impact the response of the powder blend to thermal exposure. The nucleation-reaction sites are multiplied, however, with increasing milling time and thus insure a higher number of smaller AlB2 particles. The size of the AlB2 platelets may be adjusted with the ball milling time.

Having a Ball with Fitness Balls

Science.gov (United States)

McNulty, Betty

2011-01-01

Fitness programs can be greatly enhanced with the addition of fitness balls. They are a fun, challenging, economical, and safe way to incorporate a cardiovascular, strength, and stretching program for all fitness levels in a physical education setting. The use of these balls has become more popular during the last decade, and their benefits and…

Search for primarily non-interacting decay modes of the upsilon

International Nuclear Information System (INIS)

Leffler, J.S.

1986-03-01

The hadronic transition UPSILON(2S) → π 0 π 0 UPSILON(1S) is utilized to search for the reactions: UPSILON(1S) → non-interacting particles and UPSILON(1S) → γ + non-interacting particles. 44 pb -1 of UPSILON(2S) data were taken by the Crystal Ball detector at the DORIS II storage ring in order to perform this study. An upper limit of BR(UPSILON → Unseen) -1 of UPSILON(2S) data was available for this study. An upper limit on the branching ratio BR(UPSILON → γ + Unseen) is measured for photon energies in the range 500 MeV -3 (90% C.L.), is obtained. The compact size of the Crystal Ball detector enhances the observable branching ratio for noninteracting particles with short lifetimes such as massive axions. The identification of the recent Darmstadt events with a 1.6 MeV axion is excluded by the present result assuming the minimal Peccei-Quinn model. Limits on the spontaneous supersymmetry breaking mass scale are also derived as a function of gravitino mass

Search for the two-photon decay of the 2+ first excited states in 18O and 28Si

International Nuclear Information System (INIS)

Music, M.

1986-01-01

The present work describes an attempt to measure the probability for the two-photon transition between two adjacent nuclear states in the presence of an allowed, strongly predominant one-photon decay, using the Heidelberg-Darmstadt Crystal Ball Spectrometer. The branching ratios of the two-photon decay of the first excited, 2 + levels of 18 O and 28 Si relative to the one-photon, E2 transitions to the 0 + ground states were determined to be: Wγγ/Wγ = (0.7±2.4) x 10 -6 for the 2 + >0 + transition in 18 O and Wγγ/Wγ = (1.6±1.8) x 10 -6 for the 2 + >0 + transition in 28 Si. Since both results are consistent with zero, it is possible to express them as the upper limits for the two-photon decay (3 δ) of 7.9 x 10 -6 of 18 O and 6.9 x 10 -6 of 28 Si 2 + levels. These values are by far the smallest ones reported to be observed in a two-photon decay of a nuclear state. For 18 O, the result disproves theoretical estimates of the corresponding two-photon E1F1 matrix element was well as experimental values deduced from multiple-Coulomb-excitation measurements. The main experimental difficulties were caused by the gamma rays from one-photon transitions and were found to be connected with cross-talk events due to Bremsstrahlung of Compton electrons and not - as generally believed - positron annihilation in flight. (orig.)

Deutsches Krebsforschungszentrum Heidelberg. Research report 1997/1998

International Nuclear Information System (INIS)

1999-01-01

The Deutsches Krebsforschungszentrum Heidelberg (DKFZ, German Cancer Research Center) publishes alternating every year the 'Research Report' and the 'Wissenschaftlicher Ergebnisbericht' (in German). Both volumes are reports on the present state of research activities of the DKFZ as a National Research Center to the funding federal and state authorities (Federal Republic of Germany, Land (state) Baden-Wuerttemberg). Furthermore they shall inform colleagues and the scientifically interested public. Both reports are structured according to the center's eight research programs. (orig.) [de

Heidelberg Retina Tomograph for the Detection of Glaucoma

Directory of Open Access Journals (Sweden)

Barbara Cvenkel

2012-06-01

Full Text Available Heidelberg Retina Tomograph (HRT is a confocal scanning laser ophthalmoscope which acquires and analyzes 3-dimensional images of the optic nerve head. The latest instrument HRT3 includes software with larger ethinic-specific normative database. This review summarizes relevant published literature on HRT in diagnosing glaucoma, detecting glaucoma progression, the diagnostic accuracy of HRT among other imaging devices and its role in clinical practice.

The incredible shrinking ball

Energy Technology Data Exchange (ETDEWEB)

Smith, Maurice

2011-12-15

In the oil and gas industry, the implementation of fracture systems using ball and seat technology helped make multistage fracturing possible. However, frac balls can obstruct later production flow by staying in the well. Baker Hughes Inc. developed a technology to solve this problem: IN-Tallic frac balls. The unique feature of these frac balls is that they are made of an electrolytic metallic nanostructured material which is light and strong and which melts away with salt water or brine through a decomposition process governed by electrochemical reactions controlled by nanoscale coatings. These balls need to be kept away from moisture in order to prevent degradation. This technology is more expensive than traditional frac balls but it prevents the need to mill out obstructions created by the balls. The IN-Tallic frac balls are a new technology which provides operators with peace of mind.

Influence of cation disorder on the magnetic properties of ball-milled ilmenite (FeTiO₃)

DEFF Research Database (Denmark)

Mørup, Steen; Rasmussen, Helge Kildahl; Brok, Erik

2012-01-01

We have investigated the evolution of crystal structure, cation disorder and magnetic properties of ilmenite (FeTiO3) after increasing time of high-energy ball-milling in an inert atmosphere. Refinement of X-ray diffraction data show that the hexagonal crystal structure of ilmenite is maintained...

Release procedure according to paragraph 29 StrlSchv on example of the nuclear research reactor TRIGA Heidelberg II; Durchfuehrung von Freigabeverfahren nach paragraph 29 am Beispiel des TRIGA Heidelberg II

Energy Technology Data Exchange (ETDEWEB)

Cremer, J. [Siempelkamp Nukleartechnik GmbH (SNT) (Germany); Sold, A. [Deutsches Krebsforschungszentrum Heidelberg (DKFZ) (Germany)

2005-07-01

The aim of this lecture is to show the schedule of a release procedure according to paragraph 29 StrlSchV on the example of the decommissioning of the nuclear research reactor TRIGA Heidelberg II. It is shown on the effort done by the radiation protection representative of this plant. Considering this example, starting with planning, application, survey and execution, the complex context of the release procedure is becomes apparent. Thereby the new applied measuring techniques that require a certain practice and the responsibility of the radiation protection representative in the radiation protection law play a relevant role. In such small facilities as the TRIGA Heidelberg II, the radiation protection staff are employed according to the plant's size and work is focussed on radiation protection research and laboratories. The decommissioning process with its wide range of radiation protection requirements represents new challenges which have to be coordinated with the present duties of the radiation protection representative. The supervision and the responsibility for the release procedure according to paragraph 29 are the largest and the most sensitive part of decommissioning of the nuclear research reactor TRIGA Heidelberg II. (orig.)

Search for cold and hot dark matter with the Heidelberg-Moscow experiment, HDMS, GENIUS and GENIUS-TF

International Nuclear Information System (INIS)

Klapdor-Kleingrothaus, H.V.; Dietz, A.; Krivosheina, I.V.

2003-01-01

The recent result from the Heidelberg-Moscow double beta experiment allows neutrinos still to play an important role as hot dark matter in the Universe. HDMS has started in 2001 its search for cold dark matter (WIMPS), with a HPGe crystal of enriched 73 Ge. Concerning hot dark matter, GENIUS will improve the present accuracy for the (effective) neutrino mass. At the same time GENIUS will extend the range of sensitivity in an unprecedented way to cover a wide range of the parameter space of SUSY parameters for neutralinos as cold dark matter. A GENIUS Test Facility in the Gran Sasso has been approved in 2001 and will come into operation by end of 2002. Finally some comments are given to some criticism of the result presented elsewhere

Die Britse owerheid en die onderwys op Heidelberg gedurende die ...

African Journals Online (AJOL)

The establishment of Christian National Education (CNE) Schools stimulated the concept of mother tongue education. Oor die klaskamerpraktyk en die werklike gehalte van onderrig tydens die kampskooltydperk is daar min bekend. Heidelberg wat na 1902 in 'n belangrike onderwyssentrum in Transvaal ontwikkel het, het ...

Status report of the Darmstadt polarized electron source at the S-DALINAC

Energy Technology Data Exchange (ETDEWEB)

Poltoratska, Yuliya; Barday, Roman; Bonnes, Uwe; Brunken, Marco; Eichhorn, Ralf; Eckardt, Christian; Enders, Joachim; Ingenhaag, Christoph; Goeoek, Alf; Platz, Markus; Roth, Markus; Wagner, Markus [Institut fuer Kernphysik, Technische Universitaet, Darmstadt (Germany); Mueller, Wolfgang F.O.; Weiland, Thomas [Institut fuer Theorie Elektromagnetischer Felder, Technische Universitaet, Darmstadt (Germany)

2009-07-01

The injection section of the superconducting Darmstadt electron linear accelerator S-DALINAC will soon be extended with a source of polarized electrons SPIN. The set-up consists of a 100 keV GaAs polarized gun and associated beamline including a Chopper-Prebuncher system to affect the time structure of the emitted beam, a laser system to produce polarized light with the required wavelength and an assembly for polarisation manipulation and measurement. We report on the status of the entire construction and review recent results on operation parameters. An outlook on the upcoming installation of the polarized electron source at the S-DALINAC is given.

Charged Q-ball dark matter from B and L direction

Energy Technology Data Exchange (ETDEWEB)

Hong, Jeong-Pyong; Kawasaki, Masahiro [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8582 (Japan); Kavli IPMU (WPI), UTIAS, The University of Tokyo,5-1-5 Kashiwanoha, Kashiwa, 277-8583 (Japan); Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)

2016-08-24

We consider nearly equal number of gauge mediation type charged (anti-) Q-balls with charge of ±α{sup −1}≃±137 well before the BBN epoch and discussed how they evolve in time. We found that ion-like objects with electric charges of +O(1) are likely to become relics in the present universe, which we expect to be the dark matter. These are constrained by MICA experiment, where the trail of heavy atom-like or ion-like object in 10{sup 9} years old ancient mica crystals is not observed. We found that the allowed region for gauge mediation model parameter and reheating temperature have to be smaller than the case of the neutral Q-ball dark matter.

Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.

Science.gov (United States)

Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

2013-09-01

We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (pdolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025). Copyright © 2013 Elsevier B.V. All rights reserved.

Golf Ball

Science.gov (United States)

1998-01-01

The Ultra 500 Series golf balls, introduced in 1995 by Wilson Sporting Goods Company, has 500 dimples arranged in a pattern of 60 spherical triangles. The design employs NASA's aerodynamics technology analysis of air loads of the tank and Shuttle orbiter that was performed under the Space Shuttle External Tank program. According to Wilson, this technology provides 'the most symmetrical ball surface available, sustaining initial velocity longer and producing the most stable ball flight for unmatched accuracy and distance.' The dimples are in three sizes, shapes and depths mathematically positioned for the best effect. The selection of dimples and their placement optimizes the interaction of opposing forces of lift and drag. Large dimples reduce air drag, enhance lift, and maintain spin for distance. Small dimples prevent excessive lift that destabilizes the ball flight and the medium size dimples blend the other two.

DNA sequence analysis of plasmids from multidrug resistant Salmonella enterica serotype Heidelberg isolates.

Directory of Open Access Journals (Sweden)

Jing Han

Full Text Available Salmonella enterica serovar Heidelberg is among the most detected serovars in swine and poultry, ranks among the top five serotypes associated with human salmonellosis and is disproportionately associated with invasive infections and mortality in humans. Salmonella are known to carry plasmids associated with antimicrobial resistance and virulence. To identify plasmid-associated genes in multidrug resistant S. enterica serovar Heidelberg, antimicrobial resistance plasmids from five isolates were sequenced using the 454 LifeSciences pyrosequencing technology. Four of the isolates contained incompatibility group (Inc A/C multidrug resistance plasmids harboring at least eight antimicrobial resistance genes. Each of these strains also carried a second resistance plasmid including two IncFIB, an IncHI2 and a plasmid lacking an identified Inc group. The fifth isolate contained an IncI1 plasmid, encoding resistance to gentamicin, streptomycin and sulfonamides. Some of the IncA/C plasmids lacked the full concert of transfer genes and yet were able to be conjugally transferred, likely due to the transfer genes carried on the companion plasmids in the strains. Several non-IncA/C resistance plasmids also carried putative virulence genes. When the sequences were compared to previously sequenced plasmids, it was found that while all plasmids demonstrated some similarity to other plasmids, they were unique, often due to differences in mobile genetic elements in the plasmids. Our study suggests that Salmonella Heidelberg isolates harbor plasmids that co-select for antimicrobial resistance and virulence, along with genes that can mediate the transfer of plasmids within and among other bacterial isolates. Prevalence of such plasmids can complicate efforts to control the spread of S. enterica serovar Heidelberg in food animal and human populations.

Frictional performance of ball screw

International Nuclear Information System (INIS)

Nakashima, Katuhiro; Takafuji, Kazuki

1985-01-01

As feed screws, ball screws have become to be adopted in place of trapezoidal threads. The structure of ball screws is complex, but those are the indispensable component of NC machine tools and machining centers, and are frequently used for industrial robots. As the problems in the operation of ball screws, there are damage, life and the performance related to friction. As to the damage and life, though there is the problem of the load distribution on balls, the results of the research on rolling bearings are applied. The friction of ball screws consists of the friction of balls and a spiral groove, the friction of a ball and a ball, the friction in a ball-circulating mechanism and the viscous friction of lubricating oil. It was decided to synthetically examine the frictional performance of ball screws, such as driving torque, the variation of driving torque, efficiency, the formation of oil film and so on, under the working condition of wide range, using the screws with different accuracy and the nuts of various circuit number. The experimental setup and the processing of the experimental data, the driving performance of ball screws and so on are reported. (Kako, I.)

The importance of cooperation and support for technology start-ups : a comparison of the Eindhoven and Darmstadt areas

NARCIS (Netherlands)

Halman, J.I.M.; Ulijn, J.M.; Vrande, van de V.J.A.; Umbach, F.; Ulijn, J.M.; Drillon, D.

2007-01-01

In Chapter 7, 'The importance of cooperation and support for technology start-ups: a comparison of the Eindhoven and Darmstadt areas', Johannes Halman, Jan Ulijn, Vareska van de Vrande and Frank Umbach show the results of a survey that was held among high-tech start-ups in the Eindhoven area ill the

are humans by birth as wicked as the heidelberg catechism

African Journals Online (AJOL)

the Catechism's view that (after alienation from God in the Fall) all human individuals ... capacities of empathy and altruism already in young children of different cultures as ... characterized by the natural right to self-preservation, which in itself ... and stabilizing the institutions of family, church and state in the Heidelberg.

[Evaluation of traditional German undergraduate surgical training. An analysis at Heidelberg University].

Science.gov (United States)

Schürer, S; Schellberg, D; Schmidt, J; Kallinowski, F; Mehrabi, A; Herfarth, Ch; Büchler, M W; Kadmon, M

2006-04-01

The medical faculty of Heidelberg University implemented a new problem-based clinical curriculum (Heidelberg Curriculum Medicinale, or Heicumed) in 2001. The present study analyses the evaluation data of two student cohorts prior to the introduction of Heicumed. Its aim was to specify problems of the traditional training and to draw conclusions for implementation of a new curriculum. The evaluation instrument was the Heidelberg Inventory for the Evaluation of Teaching (HILVE-I). The data were analysed calculating differences in the means between defined groups, with the 13 primary scales of the HILVE I-instrument as dependent variables. Teaching method and subject had no systematic influence on evaluation results. Thus, didactic lecture in orthopedic surgery achieved better results than small group tutorials, while the data on vascular and general surgery showed opposite results. Major factors for success were continuity and didactic training of lecturers and tutors. This is convincingly reflected by the results of the lecture course "Differential diagnosis in general surgery". The good evaluation data on small group tutorials resulted largely from the "participation" and "discussion" scales, which represent interactivity in learning. The results of the present study suggest the importance of two major pedagogic ideas: continuity and didactic training of lecturers and tutors. These principles were widely implemented in Heicumed and have contributed to the success of the new curriculum.

Individual ball possession in soccer.

Directory of Open Access Journals (Sweden)

Daniel Link

Full Text Available This paper describes models for detecting individual and team ball possession in soccer based on position data. The types of ball possession are classified as Individual Ball Possession (IBC, Individual Ball Action (IBA, Individual Ball Control (IBC, Team Ball Possession (TBP, Team Ball Control (TBC und Team Playmaking (TPM according to different starting points and endpoints and the type of ball control involved. The machine learning approach used is able to determine how long the ball spends in the sphere of influence of a player based on the distance between the players and the ball together with their direction of motion, speed and the acceleration of the ball. The degree of ball control exhibited during this phase is classified based on the spatio-temporal configuration of the player controlling the ball, the ball itself and opposing players using a Bayesian network. The evaluation and application of this approach uses data from 60 matches in the German Bundesliga season of 2013/14, including 69,667 IBA intervals. The identification rate was F = .88 for IBA and F = .83 for IBP, and the classification rate for IBC was κ = .67. Match analysis showed the following mean values per match: TBP 56:04 ± 5:12 min, TPM 50:01 ± 7:05 min and TBC 17:49 ± 8:13 min. There were 836 ± 424 IBC intervals per match and their number was significantly reduced by -5.1% from the 1st to 2nd half. The analysis of ball possession at the player level indicates shortest accumulated IBC times for the central forwards (0:49 ± 0:43 min and the longest for goalkeepers (1:38 ± 0:58 min, central defenders (1:38 ± 1:09 min and central midfielders (1:27 ± 1:08 min. The results could improve performance analysis in soccer, help to detect match events automatically, and allow discernment of higher value tactical structures, which is based on individual ball possession.

Determination of the Dalitz-plot parameter {alpha} for the decay {eta}{yields}3{pi}{sup 0} with the Crystal Ball at MAMI; Bestimmung des Dalitz-Plot-Parameters {alpha} fuer den Zerfall {eta} {yields} 3{pi}{sup 0} mit dem Crystal Ball am MAMI

Energy Technology Data Exchange (ETDEWEB)

Unverzagt, Marc

2008-05-26

In order to determine the Dalitz-plot parameter {alpha} experiments were evaluated, Which were performed with the Crystal Ball/TAPS facility at the accelerator MAMI of the Institute for Nuclear Physics at the Johannes Gutenberg University in Mainz in the years 2004 and 2005. {eta} mesons wer produced via the reaction {gamma}p{yields}{eta}p. From four different analyses the following four in this thesis determined Dalitz-plot parameters with the given statistics resulted: {eta} without proton: {alpha}=-0.0314{+-}0.0013{sub -0.0014}{sup +0.0017} (1.1.10{sup 6} events), {eta} with proton: {alpha}=-0.0338{+-}0.0020{sub -0.0022}{sup +0.0019} (4.2.10{sup 5} events), {delta}{sup +} magnetic dipole moment without proton: {alpha}=-0.0277{+-}0.0013{sub -0.0019}{sup +0.0014} (7.1.10{sup 5} events), {delta}{sup +} magnetic dipole moment with proton: {alpha}=-0.0272{+-}0.0019{sub -0.0043}{sup +0.0022} (3.1.10{sup 5} events).

Synthesis of free standing nanocrystalline Cu by ball milling at cryogenic temperature

Energy Technology Data Exchange (ETDEWEB)

Barai, K. [Department of Metallurgy and Materials Engineering, Bengal Engineering College, Shibpur, Howrah 711103 (India); Tiwary, C.S. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Chattopadhyay, P.P. [Department of Metallurgy and Materials Engineering, Bengal Engineering College, Shibpur, Howrah 711103 (India); Chattopadhyay, K., E-mail: kamanio@materials.iisc.ernet.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India)

2012-12-15

This paper reports for the first time synthesis of free standing nano-crystalline copper crystals of a {approx}30-40 nm by ball milling of copper powder at 150 K under Argon atmosphere in a specially designed cryomill. The detailed characterization of these particles using multiple techniques that includes transmission electron microscopy confirms our conclusion. Careful analysis of the chemistry of these particles indicates that these particles are essentially contamination free. Through the analysis of existing models of grain size refinements during ball milling and low temperature deformation, we argue that the suppression of thermal processes and low temperature leads to formation of free nanoparticles as the process of fracture dominates over possible cold welding at low temperatures.

Fundamentals of combustion research. Final report 2000; Grundlagen der Verbrennungsforschung. Abschlussbericht 2000

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

All ten projects were aimed at modelling and validation of practically relevant natural gas flames. Modelling comprises the use,l development and enhancement of advanced combustion and turbulence models, e.g. PDF models or higher order Reynolds stress models. Validation uses modern laser diagnostics, e.g. spontaneous Raman scattering, LIF spectroscopy, and LDA. The practical applicability is ensured by a 150 kW flame whose characteristics can be extrapolated to industrial-scale plants. For this, four identical experiments were set up in the TECFLAM institutes of Stuttgart, Karlsruhe, Heidelberg, and Darmstadt. [German] Gemeinsames Projektziel der vorliegenden zehn Vorhaben ist die Modellentwicklung und Validierung anwendungsnaher Erdgasflammen. Unter Modellentwicklung ist dabei die Nutzung, Entwicklung und Weiterentwicklung fortschrittlicher Verbrennungs- und Turbulenzmodelle wie PDF-Modelle oder Reynolds-Stress-Modelle hoeherer Ordnung zu verstehen. Validierung wird durchgefuehrt mittels moderner Laserdiagnostik-Verfahren, wie der spontanen Raman-Streuung, der LIF-Spektroskopie sowie LDA-Verfahren. Die Anwendungsnaehe wird sichergestellt durch eine Flamme mit 150 kW Leistung, deren Verhalten auf grosstechnische Anlagen extrapolierbar ist. Um dieses ehrgeizige Ziel zu erreichen, wurden vier identische Versuchsaufbauten in den TECFLAM-Instituten in Stuttgart, Karlsruhe, Heidelberg und Darmstadt errichtet. (orig.)

Ceramic Rail-Race Ball Bearings

Science.gov (United States)

Balzer, Mark A.; Mungas, Greg S.; Peters, Gregory H.

2010-01-01

Non-lubricated ball bearings featuring rail races have been proposed for use in mechanisms that are required to function in the presence of mineral dust particles in very low-pressure, dry environments with extended life. Like a conventional ball bearing, the proposed bearing would include an inner and an outer ring separated by balls in rolling contact with the races. However, unlike a conventional ball bearing, the balls would not roll in semi-circular or gothic arch race grooves in the rings: instead, the races would be shaped to form two or more rails (see figure). During operation, the motion of the balls would push dust particles into the spaces between the rails where the particles could not generate rolling resistance for the balls

Characterization of a multidrug-resistant Salmonella enterica serovar Heidelberg outbreak strain in commercial turkeys: Colonization, transmission, and host transcriptional response

Science.gov (United States)

In recent years, multidrug-resistant (MDR) Salmonella enterica serovar Heidelberg has been associated with numerous human foodborne illness outbreaks due to consumption of poultry. For example, in 2011, an MDR S. Heidelberg outbreak associated with ground turkey sickened 136 individuals and resulted...

Effect of a ball skill intervention on children's ball skills and cognitive functions.

Science.gov (United States)

Westendorp, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

2014-02-01

This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning disorders. Ninety-one children with learning disorders (age 7-11 yr old) were recruited from six classes in a Dutch special-needs primary school. The six classes were assigned randomly either to the intervention or to the control group. The control group received the school's regular physical education lessons. In the intervention group, ball skills were practiced in relative static, simple settings as well as in more dynamic and cognitive demanding settings. Both groups received two 40-min lessons per week. Children's scores on the Test of Gross Motor Development-2 (ball skills), Tower of London (problem solving), Trail Making Test (cognitive flexibility), Dutch Analysis of Individual Word Forms (reading), and the Dutch World in Numbers test (mathematics) at pretest, posttest, and retention test were used to examine intervention effects. The results showed that the intervention group significantly improved their ball skills, whereas the control group did not. No intervention effects were found on the cognitive parameters. However, within the intervention group, a positive relationship (r = 0.41, P = 0.007) was found between the change in ball skill performance and the change in problem solving: the larger children's improvement in ball skills, the larger their improvement in problem solving. The present ball skill intervention is an effective instrument to improve the ball skills of children with learning disorders. Further research is needed to examine the effect of the ball skill intervention on the cognitive parameters in this population.

A consistent magnetic polarity stratigraphy of Plio-Pleistocene fluvial sediments from the Heidelberg Basin (Germany)

Science.gov (United States)

Scheidt, Stephanie; Hambach, Ulrich; Rolf, Christian

2014-05-01

Deep drillings in the Heidelberg Basins provide access to one of the thickest and most complete successions of Quaternary and Upper Pliocene continental sediments in Central-Europe [1]. In absence of any comprehensive chronostratigraphic model, these sediments are so far classified by lithological and hydrogeological criteria. Therefore the age of this sequence is still controversially discussed ([1], [2]). In spite of the fact that fluvial sediments are a fundamental challenge for the application of magnetic polarity stratigraphy we performed a thorough study on four drilling cores (from Heidelberg, Ludwigshafen and nearby Viernheim). Here, we present the results from the analyses of these cores, which yield to a consistent chronostratigraphic framework. The components of natural remanent magnetisation (NRM) were separated by alternating field and thermal demagnetisation techniques and the characteristic remanent magnetisations (ChRM) were isolated by principle component analysis [3]. Due to the coring technique solely inclination data of the ChRM is used for the determination of the magnetic polarity stratigraphy. Rock magnetic proxies were applied to identify the carriers of the remanent magnetisation. The investigations prove the NRM as a stable, largely primary magnetisation acquired shortly after deposition (PDRM). The Matuyama-Gauss boundary is clearly defined by a polarity change in each core, as suggested in previous work [4]. These findings are in good agreement with the biostratigraphic definition of the base of the Quaternary ([5], [6], [7]). The Brunhes-Matuyama boundary could be identified in core Heidelberg UniNord 1 and 2 only. Consequently, the position of the Jaramillo and Olduvai subchron can be inferred from the lithostratigraphy and the development of fluvial facies architecture in the Rhine system. The continuation of the magnetic polarity stratigraphy into the Gilbert chron (Upper Pliocene) allows alternative correlation schemes for the cores

Deutsches Krebsforschungszentrum Heidelberg. Report on scientific results 2002-2003

International Nuclear Information System (INIS)

2004-01-01

The Deutsches Krebsforschungszentrum Heidelberg (DKFZ, German Cancer Research Center) publishes alternating every year the ''Wissenschaftlicher Ergebnisbericht'' (in German) and the ''Research Report'' (in English). Both volumes are reports on the present state of research activities of the DKFZ as a National Research Center to the funding federal and state authorities [Federal Republic of Germany, Land (state) Baden-Wuerttemberg]. The report is structured according to the center's six research programs

Status report of the S-DALINAC polarized electron injector SPIN at Darmstadt

Energy Technology Data Exchange (ETDEWEB)

Eckardt, Christian; Bahlo, Thore; Bangert, Phillip; Barday, Roman; Bonnes, Uwe; Brunken, Marco; Eichhorn, Ralf; Enders, Joachim; Platz, Markus; Poltoratska, Yuliya; Roth, Markus; Schneider, Fabian; Wagner, Markus; Weber, Antje; Zwicker, Benjamin [Institut fuer Kernphysik, Technische Universitaet Darmstadt (Germany); Ackermann, Wolfgang; Mueller, Wolfgang F.O.; Weiland, Thomas [Institut fuer Theorie Elektromagnetischer Felder, Technische Universitaet Darmstadt (Germany)

2010-07-01

At the superconducting 130 MeV Darmstadt electron linac S-DALINAC a source of polarized electrons is being installed. Polarized electrons are produced by photoemission from a negative electron affinity strained superlattice GaAs cathode and preaccelerated to 100 keV. With a Wien filter and Mott polarimeter in the beam line the polarization is manipulated and measured. For beam diagnostics wire scanners, fluorescent screens and a coaxial Faraday cup are included. To measure the beam polarization at higher energies, a 5-10 MeV Mott polarimeter and a 50-130 MeV Moeller polarimeter as well as a Compton transmission polarimeter will be installed. We report on the status of the implementation and show plans for future development and experiments.

Study of new occurrences of plastic (ball) clays from northeastern Brazil for use in refractory ceramics; Estudo de novas ocorrencias de argilas plasticas (ball clays) do nordeste do Brasil para uso em ceramicas refratarias

Energy Technology Data Exchange (ETDEWEB)

Cartaxo, J.M.; Bastos, P. de M.; Santana, L.N.L.; Menezes, R.R.; Neves, G.A.; Ferreira, H.C., E-mail: julianamelo25@gmail.com, E-mail: paulos@cstr.ufcg.edu.br, E-mail: lisiane.navarro@ufcg.edu.br, E-mail: romualdo.menezes@ufcg.edu.br, E-mail: gelmires.neves@ufcg.edu.br, E-mail: heber.ferreira@ufcg.edu.br [Universidade Federal de Campina Grande (UFCG), PB (Brazil). Programa de Pos-Graduacao em Ciencia e Engenharia de Materiais

2016-10-15

The northeast of Brazil has large deposits of ball clays generally situated in Barreiras Formation and are used in white ceramic and refractory materials. These clays are composed of secondary kaolinite and organic matter, being very plastic and when subjected to elevated temperatures burn with white colors and present phase transformations showing mainly crystals formation of mullite and cristobalite. This work aims to study new deposits of ball clays in order to use them to refractory materials production. The clays were characterized by laser diffraction, X-ray diffraction (XRD), X-ray fluorescence, refractoriness, thermal analysis, and scanning electron microscopy (SEM). The samples were pressed and sintered at 1000, 1150, 1250, 1280 and 1400 °C. The characterization after firing was carried out by XRD and SEM. Then, the physical and mechanical properties - absorption, porosity and flexural strength, were determined. The results showed that the clays presented formation of mullite crystals with physical, chemical and mineralogical properties suitable for use in refractory ceramics. (author)

Comprehensive characterization of ball-milled powders simulating a tribofilm system

Energy Technology Data Exchange (ETDEWEB)

Häusler, I., E-mail: ines.haeusler@bam.de; Dörfel, I., E-mail: Ilona.doerfel@bam.de; Peplinski, B., E-mail: Burkhard.peplinski@bam.de; Dietrich, P.M., E-mail: Paul.dietrich@yahoo.de; Unger, W.E.S., E-mail: Wolfgang.Unger@bam.de; Österle, W., E-mail: Werner.Oesterle@bam.de

2016-01-15

A model system was used to simulate the properties of tribofilms which form during automotive braking. The model system was prepared by ball milling of a blend of 70 vol.% iron oxides, 15 vol.% molybdenum disulfide and 15 vol.% graphite. The resulting mixture was characterized by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and various transmission electron microscopic (TEM) methods, including energy dispersive X-ray spectroscopy (EDXS), high resolution investigations (HRTEM) with corresponding simulation of the HRTEM images, diffraction methods such as scanning nano-beam electron diffraction (SNBED) and selected area electron diffraction (SAED). It could be shown that the ball milling caused a reduction of the grain size of the initial components to the nanometer range. Sometimes even amorphization or partial break-down of the crystal structure was observed for MoS{sub 2} and graphite. Moreover, chemical reactions lead to a formation of surface coverings of the nanoparticles by amorphous material, molybdenum oxides, and iron sulfates as derived from XPS. - Highlights: • Ball milling of iron oxides, MoS{sub 2}, and graphite to simulate a tribofilm • Increasing coefficient of friction after ball milling of the model blend • Drastically change of the diffraction pattern of the powder mixture • TEM & XPS showed the components of the milled mixture and the process during milling. • MoS{sub 2} and graphite suffered a loss in translation symmetry or became amorphous.

Carbon-based micro-ball and micro-crystal deposition using filamentary pulsed atmospheric pressure plasma

International Nuclear Information System (INIS)

Pothiraja, Ramasamy; Bibinov, Nikita; Awakowicz, Peter

2014-01-01

Thin plasma filaments are produced by the propagation of ionization waves from a spiked driven electrode in a quartz tube in an argon/methane gas mixture (2400 sccm/2 sccm) at atmospheric pressure. The position of the touch point of filaments on the substrate surface is controlled in our experiment by applying various suitable substrate configurations and geometries of the grounded electrode. The gas conditions at the touch point are varied from argon to ambient air. Based on microphotography and discharge current waveforms, the duration of the filament touching the substrate is estimated to be about one microsecond. Carbon-based materials are deposited during this time at the touch points on the substrate surface. Micro-balls are produced if the filament touch points are saved from ambient air by the argon flow. Under an air admixture, micro-crystals are formed. The dimension of both materials is approximately one micrometre (0.5–2 µm) and corresponds to about 10 10 –10 12 carbon atoms. Neither the diffusion of neutral species nor drift of ions can be reason for the formation of such a big micro-material during this short period of filament–substrate interaction. It is possible that charged carbon-based materials are formed in the plasma channel and transported to the surface of the substrate. The mechanism of this transport and characterization of micro-materials, which are formed under different gas conditions in our experiment, will be studied in the future. (paper)

Effect of ball milling time on thermoelectric properties of bismuth telluride nanomaterials

Science.gov (United States)

Khade, Poonam; Bagwaiya, Toshi; Bhattacharaya, Shovit; Singh, Ajay; Jha, Purushottam; Shelke, Vilas

2018-04-01

The effect of different milling time on thermoelectric properties of bismuth telluride (Bi2Te3) was investigated. The nanomaterial was prepared by varying the ball milling time and followed by hot press sintering. The crystal structure and phase formation were verified by X-ray diffraction and Raman Spectroscopy. The experimental results show that electrical conductivity increases whereas thermal conductivity decreases with increasing milling time. The negative sign of seebeck coefficient indicate the n-type nature with majority charge carriers of electrons. A maximum figure of merit about 0.55 is achieved for l5hr ball milled Bi2Te3 sample. The present study demonstrates the simple and cost-effective method for synthesis of Bi2Te3 thermoelectric material at large scale thermoelectric applications.

Optical and Acoustic Sensor-Based 3D Ball Motion Estimation for Ball Sport Simulators †

Directory of Open Access Journals (Sweden)

Sang-Woo Seo

2018-04-01

Full Text Available Estimation of the motion of ball-shaped objects is essential for the operation of ball sport simulators. In this paper, we propose an estimation system for 3D ball motion, including speed and angle of projection, by using acoustic vector and infrared (IR scanning sensors. Our system is comprised of three steps to estimate a ball motion: sound-based ball firing detection, sound source localization, and IR scanning for motion analysis. First, an impulsive sound classification based on the mel-frequency cepstrum and feed-forward neural network is introduced to detect the ball launch sound. An impulsive sound source localization using a 2D microelectromechanical system (MEMS microphones and delay-and-sum beamforming is presented to estimate the firing position. The time and position of a ball in 3D space is determined from a high-speed infrared scanning method. Our experimental results demonstrate that the estimation of ball motion based on sound allows a wider activity area than similar camera-based methods. Thus, it can be practically applied to various simulations in sports such as soccer and baseball.

The bowling balls

CERN Multimedia

CERN Bulletin

2010-01-01

10 November 1972: CERN’s Bent Stumpe places an order for 12 bowling balls for a total cost of 95 US dollars. Although not evident at first sight, he is buying the heart of some of the first tracking devices to be used in the SPS control room. Today, Bent Stumpe’s device would be called a desktop mouse…   The first order for 4 bowling balls later changed to 12 balls. The bowling balls became the heart of Bent Stumpe's mouse. Almost 40 years ago, the web, Wikipedia and Google did not exist and it was much more difficult to know whether other people in other parts of the world or even in the same laboratory were facing the same problems or developing the same tools. At that time, Bent Stumpe was an electronics engineer, newly recruited to work on developments for the SPS Central Control room. One of the things his supervisor asked him to build as soon as possible was a device to control a pointer on a screen, also called a tracker ball. The heart of the device was the...

The spinning ball spiral

International Nuclear Information System (INIS)

Dupeux, Guillaume; Le Goff, Anne; Quere, David; Clanet, Christophe

2010-01-01

We discuss the trajectory of a fast revolving solid ball moving in a fluid of comparable density. As the ball slows down owing to drag, its trajectory follows an exponential spiral as long as the rotation speed remains constant: at the characteristic distance L where the ball speed is significantly affected by the drag, the bending of the trajectory increases, surprisingly. Later, the rotation speed decreases, which makes the ball follow a second kind of spiral, also described in the paper. Finally, the use of these highly curved trajectories is shown to be relevant to sports.

Compact Q-balls

Energy Technology Data Exchange (ETDEWEB)

Bazeia, D., E-mail: bazeia@fisica.ufpb.br [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Losano, L.; Marques, M.A. [Departamento de Física, Universidade Federal da Paraíba, 58051-970 João Pessoa, PB (Brazil); Menezes, R. [Departamento de Ciências Exatas, Universidade Federal da Paraíba, 58297-000 Rio Tinto, PB (Brazil); Departamento de Física, Universidade Federal de Campina Grande, 58109-970 Campina Grande, PB (Brazil); Rocha, R. da [Centro de Matemática, Computação e Cognição, Universidade Federal do ABC, 09210-580 Santo André (Brazil)

2016-07-10

In this work we deal with non-topological solutions of the Q-ball type in two space–time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls solutions that live in a compact interval of the real line and appear from a family of models controlled by two distinct parameters. We find analytical solutions and study their charge and energy, and show how to control the parameters to make the Q-balls classically and quantum mechanically stable.

First lasing of the Darmstadt cw free electron laser

CERN Document Server

Brunken, M; Eichhorn, R; Genz, H; Gräf, H D; Loos, H; Richter, A; Schweizer, B; Stascheck, A; Wesp, T

1999-01-01

The Darmstadt CW FEL designed for wavelengths between 3 and 10 mu m driven by the superconducting electron accelerator S-DALINAC first lased on December 1st, 1996 and has operated thereafter successfully in the wavelength region between 6.6 and 7.8 mu m. The pulsed electron beam employed had a micro pulse length of about 2ps, with a repetition rate of 10 MHz and a peak current of 2.7 A while its energy was varied between 29.6 and 31.5 MeV. A wedged pole hybrid undulator, with 80 periods each of 0.032 m length and a magnetic field strength of 0.15-0.4T, was located in between a 15.01 m long optical cavity equipped with two high reflectivity (99.8) mirrors of 0.05 m diameter. Due to the low beam current special care with respect to the electron and optical beam properties was necessary to meet the stringent conditions in order to reach a minute small signal gain of at least a few percent resulting in amplification. Saturation was obtained after about 2000 repetitions of the photon pulse inside the cavity. The D...

Impact of the choice of reference genome on the ability of the core genome SNV methodology to distinguish strains of Salmonella enterica serovar Heidelberg.

Science.gov (United States)

Usongo, Valentine; Berry, Chrystal; Yousfi, Khadidja; Doualla-Bell, Florence; Labbé, Genevieve; Johnson, Roger; Fournier, Eric; Nadon, Celine; Goodridge, Lawrence; Bekal, Sadjia

2018-01-01

Salmonella enterica serovar Heidelberg (S. Heidelberg) is one of the top serovars causing human salmonellosis. The core genome single nucleotide variant pipeline (cgSNV) is one of several whole genome based sequence typing methods used for the laboratory investigation of foodborne pathogens. SNV detection using this method requires a reference genome. The purpose of this study was to investigate the impact of the choice of the reference genome on the cgSNV-informed phylogenetic clustering and inferred isolate relationships. We found that using a draft or closed genome of S. Heidelberg as reference did not impact the ability of the cgSNV methodology to differentiate among 145 S. Heidelberg isolates involved in foodborne outbreaks. We also found that using a distantly related genome such as S. Dublin as choice of reference led to a loss in resolution since some sporadic isolates were found to cluster together with outbreak isolates. In addition, the genetic distances between outbreak isolates as well as between outbreak and sporadic isolates were overall reduced when S. Dublin was used as the reference genome as opposed to S. Heidelberg.

ASSESSMENT OF BENZOPHENANTHRIDINE AND PROTOPINE ALKALOIDS IN BROILER CHALLENGED AND NOT BY SALMONELLA HEIDELBERG

Directory of Open Access Journals (Sweden)

PFG Previato do Amaral

Full Text Available ABSTRACT Salmonellosis is a globally important zoonosis, and Salmonella Heidelberg is one of the most prevalent serovars in poultry production worldwide, as well as in food poisoning cases. Antimicrobial drugs were previously widely used to face health challenges in animal production; however, since their ban as performance enhancers, many alternative strategies have been proposed. One of these strategies is the use of plant extracts, such as those containing the alkaloids benzophenanthridine and protopine. These compounds have antimicrobial, anti-inflammatory, immunomodulation, and nutritional effects. The objective of the present study was to evaluate the effects of the supply of a product containing benzophenanthridine and protopine (Sangrovit(rWS 100 g/1000 L of drinking water to broilers during different rearing periods 1-21, 1-6 and 6-21 days of age challenged or not with Salmonella Heidelberg at six days of age. There was no effect of the product on the performance, jejunal morphometry, cecal goblet cell counts, or control of Salmonella spp. in broilers challenged or not with Salmonella Heidelberg. However, the group receiving the alkaloids from 1 to 21 days of age, compared with the control group, presented a numerical difference of 28 points in productive efficiency index, which directly impacts live production cost of live broiler, representing savings of R$ 0.11/kg of meat produced.

THE MOUSEION IDEAL REINTERPRETED AS ART COLONY ON THE OUTSKIRTS OF DARMSTADT AND HAGEN = EL IDEAL DEL MOUSEION REINTERPRETADO COMO COLONIA ARTÍSTICA EN LAS AFUERAS DE DARMSTADT Y HAGEN

Directory of Open Access Journals (Sweden)

Jesús-Pedro Lorente Lorente

2014-02-01

Full Text Available Artists colonies proliferated during the 19th century; but some especially ambitious were founded in the early 20th century: in a broader sense they could be called ‘art colonies’. Apart from a high density of painters, sculptors, architects or other creative inhabitants, these places were noticeable for their elegant art ornaments and in some cases museums or exhibition spaces were planned as their epicentre. Two of the most outstanding cases were founded on the outskirts of the German cities of Darmstadt and Hagen. Their respective promoters coveted the integration of arts and crafts, a typical art nouveau idea. On the other hand, they were also re-enacting the classic mouseion ideal, even with their high location, towering over their respective city. In both cases such ‘city crown’ would become with time a museum complex in the modern sense of the world.A lo largo del siglo XIX proliferaron las colonias de artistas; pero a comienzos del XX se fundaron algunas especialmente ambiciosas, que cabe calificar como “artísticas” en un sentido más amplio, pues no sólo se concentraba en ellas una importante población de pintores, escultores, arquitectos u otros creadores, sino que además se distinguieron por sus elegantes ornamentos artísticos, e incluso se planeó como su respectivo epicentro algún museo o espacio expositivo. Dos de los ejemplos más señalados fueron fundados en las afueras de las ciudades alemanas de Darmstadt y Hagen por sendos mecenas que aspiraban a la integración de artes y artesanía, una utopía propia del art nouveau. Por otra parte, revivían también el sueño clásico del mouseion, hasta por su ubicación elevada por encima de la urbe respectiva. En uno y otro caso, esa “corona urbana” se convertiría con el tiempo en un complejo museístico, en el moderno significado del término.

LHC gets the ball rolling

CERN Multimedia

2007-01-01

A technique involving a small ball with a transmitter embedded inside it has been successfully tested in Sector 7-8. The ball is sent through the LHC beam pipes to check the LHC interconnections. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI). During the tests the ball is inserted very carefully into the vacuum chamber.A game of ping-pong at the LHC? On 13 September a rather unusual test was carried out in Sector 7-8 of the accelerator. A ball just a bit smaller than a ping-pong ball was carefully introduced into one of the accelerator’s two vacuum pipes, where it travelled 800 metres in the space of a few mi...

Genotypic relatedness and antimicrobial resistance of Salmonella Heidelberg isolated from chickens and turkeys in the midwestern United States.

Science.gov (United States)

Nisar, Muhammad; Kassem, Issmat I; Rajashekara, Gireesh; Goyal, Sagar M; Lauer, Dale; Voss, Shauna; Nagaraja, Kakambi V

2017-05-01

Salmonella is one of the most common causes of foodborne illnesses in humans in the United States, and domestic poultry is considered an important source of this pathogen. Salmonella enterica subsp. enterica serovar Heidelberg is the fourth most commonly reported Salmonella from retail meats and food animals in the United States. We assessed the genotypes and antimicrobial resistance phenotypes of Salmonella Heidelberg isolated from various chicken and turkey hatcheries and breeder farms in the Midwest. The genotypes of 33 S. Heidelberg isolates from chickens ( n = 19) and turkeys ( n = 14) were compared using pulsed-field gel electrophoresis analysis. Cluster analysis of the fingerprints showed that the majority of the chicken isolates grouped together with 87% similarity; those from turkeys clustered with 88% similarity. Similarity between chicken and turkey isolates was also high (86%). Isolates from turkeys were generally more genetically diverse than those from chickens. Antimicrobial susceptibility analysis detected resistance to sulfisoxazole (36% of the isolates), streptomycin (33%), gentamicin (27%), tetracycline (24%), ampicillin and amoxicillin-clavulanic acid (15%), cefoxitin (12%), ceftriaxone and ceftiofur (12%), and chloramphenicol (9%). None of the isolates was resistant to azithromycin, ciprofloxacin, or nalidixic acid. Although the number of the isolates was limited in our study, we conclude that S. Heidelberg isolates from the same host generally clustered together and that a considerable number of the isolates were resistant to a number of antimicrobial agents.

Universal crystal cooling device for precession cameras, rotation cameras and diffractometers

International Nuclear Information System (INIS)

Hajdu, J.; McLaughlin, P.J.; Helliwell, J.R.; Sheldon, J.; Thompson, A.W.

1985-01-01

A versatile crystal cooling device is described for macromolecular crystallographic applications in the 290 to 80 K temperature range. It utilizes a fluctuation-free cold-nitrogen-gas supply, an insulated Mylar crystal cooling chamber and a universal ball joint, which connects the cooling chamber to the goniometer head and the crystal. The ball joint is a novel feature over all previous designs. As a result, the device can be used on various rotation cameras, precession cameras and diffractometers. The lubrication of the interconnecting parts with graphite allows the cooling chamber to remain stationary while the crystal and goniometer rotate. The construction allows for 360 0 rotation of the crystal around the goniometer axis and permits any settings on the arcs and slides of the goniometer head (even if working at 80 K). There are no blind regions associated with the frame holding the chamber. Alternatively, the interconnecting ball joint can be tightened and fixed. This results in a set up similar to the construction described by Bartunik and Schubert where the cooling chamber rotates with the crystal. The flexibility of the systems allows for the use of the device on most cameras or diffractometers. THis device has been installed at the protein crystallographic stations of the Synchrotron Radiation Source at Daresbury Laboratory and in the Laboratory of Molecular Biophysics, Oxford. Several data sets have been collected with processing statistics typical of data collected without a cooling chamber. Tests using the full white beam of the synchrotron also look promising. (orig./BHO)

Food Grade Pimenta Leaf Essential Oil Reduces the Attachment of Salmonella enterica Heidelberg (2011 Ground Turkey Outbreak Isolate on to Turkey Skin

Directory of Open Access Journals (Sweden)

Divek V. T. Nair

2017-11-01

Full Text Available Salmonella attached to the poultry skin is a major source of carcass contamination during processing. Once attached to the poultry skin, it is difficult to detach and inactivate Salmonella by commonly used antimicrobial agents since the pathogen is entrapped deeply in the feather follicles and the crevices on the skin. Essential oils could be natural, safe, and effective alternatives to synthetic antimicrobial agents during commercial and organic processing setup. The present study evaluated the efficacy of pimenta (Pimenta officinalis Lindl. leaf essential oil (PEO, and its nanoemulsion in reducing Salmonella Heidelberg attachment on to turkey (Meleagris gallopavo skin during simulated scalding (65°C and chilling (4°C steps in poultry processing. A multidrug resistant S. Heidelberg isolate from the 2011 ground turkey outbreak in the United States was used in the study. Results showed that PEO and the nanoemulsion resulted in significant reduction of S. Heidelberg attachment on turkey skin. Turkey skin samples treated with 1.0% PEO for 5 min resulted in >2 log10 CFU/sq. inch reduction of S. Heidelberg at 65 and 4°C, respectively (n = 6; P < 0.05. Similarly, skin samples treated with 1.0% pimenta nanoemulsion (PNE for 5 min resulted in 1.5- and 1.8- log10 CFU/sq. inch reduction of S. Heidelberg at 65 and 4°C, respectively (n = 6; P < 0.05. In addition, PEO and PNE were effective in reducing S. Heidelberg on skin during short-term storage at 4 and 10°C (temperature abuse (n = 6; P < 0.05. No Salmonella was detected in the dipping solution containing 0.5 or 1.0% PEO or PNE, whereas a substantial population of the pathogen survived in the control dipping solution. The results were validated using scanning electron -, and confocal - microscopy techniques. PEO or PNE could be utilized as an effective antimicrobial agent to reduce S. Heidelberg attachment to turkey skin during poultry processing.

Validation of cooking methods using shell eggs inoculated with Salmonella serotypes Enteritidis and Heidelberg.

Science.gov (United States)

Davis, A L; Curtis, P A; Conner, D E; McKee, S R; Kerth, L K

2008-08-01

Salmonella enterica serotype Enteritidis has long been associated with eggs, and more recently, Salmonella enterica serotype Heidelberg has also become associated with eggs. This study was undertaken to determine whether Salmonella Enteritidis and Salmonella Heidelberg are effectively eliminated from eggs by various cooking methods. Seven cooking methods were chosen--hard and soft cooked, scrambled, over easy, sunny-side up, poached, and free poached--and a pan insert and the free-flowing method were used. Shell eggs, purchased from a grocery store, were inoculated with Salmonella and cooked. The cooked eggs were analyzed by USDA-approved methods for Salmonella recovery. Findings indicated that existing cooking methods for the hard-cooked, soft-cooked, and poaching methods were safe. However, the same was not true for the current sunny-side-up, over-easy, and scrambled egg cooking methods.

The Goldenrod Ball Gall

Science.gov (United States)

Fischer, Richard B.

1974-01-01

The paper presents a generalized life history of the goldenrod ball gall, a ball-shaped swelling found almost exclusively on the Canada goldenrod, Solidago canadensis, and caused by a peacock fly know as Eurosta soldiaginis. (KM)

Collective flow effects observed with the Plastic Ball

International Nuclear Information System (INIS)

Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.

1984-01-01

At the Bevalac, collisions of Ca + Ca and Nb + Nb at 400 MeV/nucleon have been studied with the Plastic Ball/Plastic Wall detector. The Plastic Ball covers the angular region between 10 0 and 160 0 . It consists of 815 detectors where each module is a ΔE-E telescope capable of identifying the hydrogen and helium isotopes and positive pions. The ΔE measurement is performed with a 4-mm thick CaF crystal and the E counter is a 36-cm long plastic scintillator. Both signals are read out by a single photomultiplier tube. Due to the different decay times of the two scintillators, ΔE and E information can be separated by gating two different ADC-s at different times. The positive pions are additionally identified by measuring the delayed decay. The Platic Wall, placed 6 m downstream from the target, covers the angular range from 0 0 to 10 0 and measures time of flight, energy loss and position of the reaction products. In addition, the information from the inner counters (0 0 to 2 0 ) is used to produce a trigger signal. Data show two different collection effects

A new measurement of the rare decay eta -> pi^0 gamma gamma with the Crystal Ball/TAPS detectors at the Mainz Microtron

Energy Technology Data Exchange (ETDEWEB)

Nefkens, B M; Prakhov, S; Aguar-Bartolom��, P; Annand, J R; Arends, H J; Bantawa, K; Beck, R; Bekrenev, V; Bergh��user, H; Braghieri, A; Briscoe, W J; Brudvik, J; Cherepnya, S; Codling, R F; Collicott, C; Costanza, S; Danilkin, I V; Denig, A; Demissie, B; Dieterle, M; Downie, E J; Drexler, P; Fil' kov, L V; Fix, A; Garni, S; Glazier, D I; Gregor, R; Hamilton, D; Heid, E; Hornidge, D; Howdle, D; Jahn, O; Jude, T C; Kashevarov, V L; K��ser, A; Keshelashvili, I; Kondratiev, R; Korolija, M; Kotulla, M; Koulbardis, A; Kruglov, S; Krusche, B; Lisin, V; Livingston, K; MacGregor, I J; Maghrbi, Y; Mancel, J; Manley, D M; McNicoll, E F; Mekterovic, D; Metag, V; Mushkarenkov, A; Nikolaev, A; Novotny, R; Oberle, M; Ortega, H; Ostrick, M; Ott, P; Otte, P B; Oussena, B; Pedroni, P; Polonski, A; Robinson, J; Rosner, G; Rostomyan, T; Schumann, S; Sikora, M H; Starostin, A; Strakovsky, I I; Strub, T; Suarez, I M; Supek, I; Tarbert, C M; Thiel, M; Thomas, A; Unverzagt, M; Watts, D P; Werthmueller, D; Witthauer, L

2014-08-01

A new measurement of the rare, doubly radiative decay eta->pi^0 gamma gamma was conducted with the Crystal Ball and TAPS multiphoton spectrometers together with the photon tagging facility at the Mainz Microtron MAMI. New data on the dependence of the partial decay width, Gamma(eta->pi^0 gamma gamma), on the two-photon invariant mass squared, m^2(gamma gamma), as well as a new, more precise value for the decay width, Gamma(eta->pi^0 gamma gamma) = (0.33+/-0.03_tot) eV, are based on analysis of 1.2 x 10^3 eta->pi^0 gamma gamma decays from a total of 6 x 10^7 eta mesons produced in the gamma p -> eta p reaction. The present results for dGamma(eta->pi^0 gamma gamma)/dm^2(gamma gamma) are in good agreement with previous measurements and recent theoretical calculations for this dependence.

Dynamics of a Bouncing Ball

Science.gov (United States)

Liang, Shiuan-Ni; Lan, Boon Leong

The dynamics of a bouncing ball undergoing repeated inelastic impacts with a table oscillating vertically in a sinusoidal fashion is studied using Newtonian mechanics and general relativistic mechanics. An exact mapping describes the bouncing ball dynamics in each theory. We show, contrary to expectation, that the trajectories predicted by Newtonian mechanics and general relativistic mechanics from the same parameters and initial conditions for the ball bouncing at low speed in a weak gravitational field can rapidly disagree completely. The bouncing ball system could be realized experimentally to test which of the two different predicted trajectories is correct.

Proposal for the Study of Thermophysical Properties of High-Energy-Density Matter Using Current and Future Heavy-Ion Accelerator Facilities at GSI Darmstadt

International Nuclear Information System (INIS)

Tahir, N.A.; Spiller, P.; Deutsch, C.; Fortov, V.E.; Gryaznov, V.; Kulish, M.; Lomonosov, I.V.; Mintsev, V.; Nikolaev, D.; Shilkin, N.; Shutov, A.; Ternovoi, V.; Hoffmann, D.H.H.; Ni, P.; Udrea, S.; Varentsov, D.; Piriz, A.R.; Temporal, M.

2005-01-01

The subject of high-energy-density (HED) states in matter is of considerable importance to numerous branches of basic as well as applied physics. Intense heavy-ion beams are an excellent tool to create large samples of HED matter in the laboratory with fairly uniform physical conditions. Gesellschaft fuer Schwerionenforschung, Darmstadt, is a unique worldwide laboratory that has a heavy-ion synchrotron, SIS18, that delivers intense beams of energetic heavy ions. Construction of a much more powerful synchrotron, SIS100, at the future international facility for antiprotons and ion research (FAIR) at Darmstadt will lead to an increase in beam intensity by 3 orders of magnitude compared to what is currently available. The purpose of this Letter is to investigate with the help of two-dimensional numerical simulations, the potential of the FAIR to carry out research in the field of HED states in matter

Simulation of ball motion and energy transfer in a planetary ball mill

International Nuclear Information System (INIS)

Lu Sheng-Yong; Mao Qiong-Jing; Li Xiao-Dong; Yan Jian-Hua; Peng Zheng

2012-01-01

A kinetic model is proposed for simulating the trajectory of a single milling ball in a planetary ball mill, and a model is also proposed for simulating the local energy transfer during the ball milling process under no-slip conditions. Based on the kinematics of ball motion, the collision frequency and power are described, and the normal impact forces and effective power are derived from analyses of collision geometry. The Hertzian impact theory is applied to formulate these models after having established some relationships among the geometric, dynamic, and thermophysical parameters. Simulation is carried out based on two models, and the effects of the rotation velocity of the planetary disk Ω and the vial-to-disk speed ratio ω/Ω on other kinetic parameters is investigated. As a result, the optimal ratio ω/Ω to obtain high impact energy in the standard operating condition at Ω = 800 rpm is estimated, and is equal to 1.15. (interdisciplinary physics and related areas of science and technology)

Ceramic ball grid array package stress analysis

Science.gov (United States)

Badri, S. H. B. S.; Aziz, M. H. A.; Ong, N. R.; Sauli, Z.; Alcain, J. B.; Retnasamy, V.

2017-09-01

The ball grid array (BGA), a form of chip scale package (CSP), was developed as one of the most advanced surface mount devices, which may be assembled by an ordinary surface ball bumps are used instead of plated nickel and gold (Ni/Au) bumps. Assembly and reliability of the BGA's printed circuit board (PCB), which is soldered by conventional surface mount technology is considered in this study. The Ceramic Ball Grid Array (CBGA) is a rectangular ceramic package or square-shaped that will use the solder ball for external electrical connections instead of leads or wire for connections. The solder balls will be arranged in an array or grid at the bottom of the ceramic package body. In this study, ANSYS software is used to investigate the stress on the package for 2 balls and 4 balls of the CBGA package with the various force range of 1-3 Newton applied to the top of the die, top of the substrate and side of the substrate. The highest maximum stress was analyzed and the maximum equivalent stress was observed on the solder ball and the die. From the simulation result, the CBGA package with less solder balls experience higher stress compared to the package with many solder balls. Therefore, less number of solder ball on the CBGA package results higher stress and critically affect the reliability of the solder balls itself, substrate and die which can lead to the solder crack and also die crack.

An induction accelerator for the Heidelberg Test Storage Ring TSR

International Nuclear Information System (INIS)

Ellert, C.; Habs, D.; Music, M.; Schwalm, D.; Wolf, A.; Jaeschke, E.; Kambara, T.; Sigray, P.

1992-01-01

An induction accelerator has been installed in the heavy ion test storage ring TSR in Heidelberg. It allows for constant acceleration or deceleration of stored coasting ion beams without affecting their velocity profile and is well suited for ion beam manipulation in cooling experiments and for measurements of velocity dependent cooling forces. The design and operation of the device and first applications to laser cooling and to measurements of laser and electron cooling forces are described. (orig.)

2012 Problem 15: Frustrating Golf Ball

Science.gov (United States)

Huang, Shan; Zhu, Zheyuan; Gao, Wenli; Wang, Sihui

2015-10-01

This paper studies the condition for a golf ball to escape from a hole. The two determining factors are the ball's initial velocity v0 and its deviation from the center of the hole d. There is a critical escaping velocity vc for every deviation d. The ball's motion is analyzed by calculating the change of velocity whenever the ball collides with the hole. The critical conditions predicted by our theory are verified through experiment.

Heidelberg Ion Therapy Center (HIT): Initial clinical experience in the first 80 patients

Energy Technology Data Exchange (ETDEWEB)

Combs, Stephanie E. (Univ. Hospital of Heidelberg, Dept. of Radiation Oncology, Heidelberg (Germany)), E-mail: Stephanie.Combs@med.uni-heidelberg.de; Ellerbrock, Malte; Haberer, Thomas (Heidelberger Ionenstrahl Therapiezentrum (HIT), Im Neuenheimer Feld 450, 69120 Heidelberg (Germany)) (and others)

2010-10-15

The Heidelberg Ion Therapy Center (HIT) started clinical operation in November 2009. In this report we present the first 80 patients treated with proton and carbon ion radiotherapy and describe patient selection, treatment planning and daily treatment for different indications. Patients and methods. Between November 15, 2009 and April 15, 2010, 80 patients were treated at the Heidelberg Ion Therapy Center (HIT) with carbon ion and proton radiotherapy. Main treated indications consisted of skull base chordoma (n = 9) and chondrosarcoma (n = 18), malignant salivary gland tumors (n=29), chordomas of the sacrum (n = 5), low grade glioma (n=3), primary and recurrent malignant astrocytoma and glioblastoma (n=7) and well as osteosarcoma (n = 3). Of these patients, four pediatric patients aged under 18 years were treated. Results. All patients were treated using the intensity-modulated rasterscanning technique. Seventy-six patients were treated with carbon ions (95%), and four patients were treated with protons. In all patients x-ray imaging was performed prior to each fraction. Treatment concepts were based on the initial experiences with carbon ion therapy at the Gesellschaft fuer Schwerionenforschung (GSI) including carbon-only treatments and carbon-boost treatments with photon-IMRT. The average time per fraction in the treatment room per patient was 29 minutes; for irradiation only, the mean time including all patients was 16 minutes. Position verification was performed prior to every treatment fraction with orthogonal x-ray imaging. Conclusion. Particle therapy could be included successfully into the clinical routine at the Dept. of Radiation Oncology in Heidelberg. Numerous clinical trials will subsequently be initiated to precisely define the role of proton and carbon ion radiotherapy in radiation oncology.

Effect of a ball skill intervention on children's ball skills and cognitive functions

NARCIS (Netherlands)

Westendorp-Haverdings, Marieke; Houwen, Suzanne; Hartman, Esther; Mombarg, Remo; Smith, Joanne; Visscher, Chris

Purpose: This study examined the effect of a 16-wk ball skill intervention on the ball skills, executive functioning (in terms of problem solving and cognitive flexibility), and in how far improved executive functioning leads to improved reading and mathematics performance of children with learning

Ball mounting fixture for a roundness gage

Science.gov (United States)

Gauler, Allen L.; Pasieka, Donald F.

1983-01-01

A ball mounting fixture for a roundness gage is disclosed. The fixture includes a pair of chuck assemblies oriented substantially transversely with respect to one another and mounted on a common base. Each chuck assembly preferably includes a rotary stage and a wobble plate affixed thereto. A ball chuck affixed to each wobble plate is operable to selectively support a ball to be measured for roundness, with the wobble plate permitting the ball chuck to be tilted to center the ball on the axis of rotation of the rotary stage. In a preferred embodiment, each chuck assembly includes a vacuum chuck operable to selectively support the ball to be measured for roundness. The mounting fixture enables a series of roundness measurements to be taken with a conventional rotating gagehead roundness instrument, which measurements can be utilized to determine the sphericity of the ball.

Heavy ion effects on mammalian cells: Inactivation measurements with different cell lines

International Nuclear Information System (INIS)

Wulf, H.; Kraft-Weyrather, W.; Miltenburger, H.G.; Kraft, G.

1985-07-01

In track segment experiments, the inactivation of different mammalian cells by heavy charged particles between helium and uranium in the energy range between 1 and 1000 MeV/u has been measured at the heavy ion accelerator Unilac, Darmstadt, the Tandem Van de Graaf, Heidelberg and the Bevalac, Berkeley. The inactivation cross sections calculated from the final slope of the dose effect curves are given as a function of the particle energy and the LET. (orig.)

Counter support for WA35

CERN Multimedia

CERN PhotoLab

1977-01-01

This assembly was equipped with 78 counters, each consisting of a lucite cone, to produce Cerenkov light, and a CsI scintillator plate of 3 mm thickness glued on the face of the cone. The experiment WA35 was set-up in the s1 beam (West Hall) by the Darmstadt-Heidelberg-Virginia-Warsaw Collaboration to measure angular distributions and multiplicities of pions and recoil protons produced by hadrons interacting in nuclei. (See Annual Report 1976 p. 39)

Structure and magnetism of SmCo5 nanoflakes prepared by surfactant-assisted ball milling with different ball sizes

International Nuclear Information System (INIS)

Nie, Junwu; Han, Xianghua; Du, Juan; Xia, Weixing; Zhang, Jian; Guo, Zhaohui; Yan, Aru; Li, Wei; Ping Liu, J.

2013-01-01

Anisotropic magnetic SmCo 5 nanoflakes have been fabricated by surfactant-assisted ball milling (SABM) using hardened steel balls of one of the following sizes: 4, 6.5, 9.5 and 12.7 mm in diameters. The magnetic properties of SmCo 5 particles prepared by SABM with different milling ball sizes in diameters were investigated systematically. It was showed that the nanoflakes milled by amount of small size balls had a higher coercivity and lower anisotropy, i.e., worse grain orientation although in a short milling time while the nanoflakes prepared with same weight of big balls tend to have a lower coercivity, better grain orientation. The coercivity mechanism of the nanoflake was studied and it was mainly dominated with the domain-wall pinning. The SEM analysis shows that the morphology of nanoflakes prepared with different ball sizes are almost the same when the balls to powder weight ratio is fixed. The different magnetic properties caused by different ball sizes are mainly due to the different microstructure changes, i.e, grain refinement and c-axis orientation, which are demonstrated by X-ray diffraction (XRD) analysis and transmission electron microscope (TEM). Based on the experiments above, a combined milling process was suggested and done to improve magnetic properties as your need. - Highlights: • We fabricated anisotropic magnetic SmCo 5 nanoflakes by surfactant-assisted ball milling (SABM). • We investigated the magnetic properties of SmCo 5 particles systematically. It was showed that the coercivity, high or low, and grain orientation, good or bad, were influenced strongly by balls size. The different magnetisms caused by different ball sizes is mainly due to the different microstructure changes. • The coercivity mechanism of the nanoflake was studied and it was mainly dominated with the domain-wall pinning

Study of soccer ball flight trajectory

Directory of Open Access Journals (Sweden)

Javorova Juliana

2018-01-01

Full Text Available In this paper the trajectories of a soccer ball for the most important kicks in the football game - a corner kick and a direct free kick are studied. The soccer ball is modelled as an ideal rigid hollow spherical body with six degrees of freedom, which performs a general motion in an immovable air environment with constant parameters. The ball 3D orientation is determined by the three Cardan angles. The aerodynamic forces and moments with which the air environment acts to the ball are taken into account. Two of the most dangerous areas of the football goal are defined. Differential equations which describe the motion of the soccer ball are solved numerically by MatLab-Simulink.

Respiratory disease in ball pythons (Python regius) experimentally infected with ball python nidovirus.

Science.gov (United States)

Hoon-Hanks, Laura L; Layton, Marylee L; Ossiboff, Robert J; Parker, John S L; Dubovi, Edward J; Stenglein, Mark D

2018-04-01

Circumstantial evidence has linked a new group of nidoviruses with respiratory disease in pythons, lizards, and cattle. We conducted experimental infections in ball pythons (Python regius) to test the hypothesis that ball python nidovirus (BPNV) infection results in respiratory disease. Three ball pythons were inoculated orally and intratracheally with cell culture isolated BPNV and two were sham inoculated. Antemortem choanal, oroesophageal, and cloacal swabs and postmortem tissues of infected snakes were positive for viral RNA, protein, and infectious virus by qRT-PCR, immunohistochemistry, western blot and virus isolation. Clinical signs included oral mucosal reddening, abundant mucus secretions, open-mouthed breathing, and anorexia. Histologic lesions included chronic-active mucinous rhinitis, stomatitis, tracheitis, esophagitis and proliferative interstitial pneumonia. Control snakes remained negative and free of clinical signs throughout the experiment. Our findings establish a causal relationship between nidovirus infection and respiratory disease in ball pythons and shed light on disease progression and transmission. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Supersymmetric Q-balls theory and cosmology

CERN Document Server

Kusenko, A

1999-01-01

MSSM predicts the existence of Q-balls, some of which can be entirely stable. Both stable and unstable Q-balls can play an important role in cosmology. In particular, Affleck-Dine baryogenesis can result in a copious production of stable baryonic Q-balls, which can presently exist as a form of dark matter.

The relationships between impact location and post-impact ball speed, bat torsion, and ball direction in cricket batting.

Science.gov (United States)

Peploe, C; McErlain-Naylor, S A; Harland, A R; King, M A

2018-06-01

Three-dimensional kinematic data of bat and ball were recorded for 239 individual shots performed by twenty batsmen ranging from club to international standard. The impact location of the ball on the bat face was determined and assessed against the resultant instantaneous post-impact ball speed and measures of post-impact bat torsion and ball direction. Significant negative linear relationships were found between post-impact ball speed and the absolute distance of impact from the midline medio-laterally and sweetspot longitudinally. Significant cubic relationships were found between the distance of impact from the midline of the bat medio-laterally and both a measure of bat torsion and the post-impact ball direction. A "sweet region" on the bat face was identified whereby impacts within 2 cm of the sweetspot in the medio-lateral direction, and 4.5 cm in the longitudinal direction, caused reductions in ball speed of less than 6% from the optimal value, and deviations in ball direction of less than 10° from the intended target. This study provides a greater understanding of the margin for error afforded to batsmen, allowing researchers to assess shot success in more detail, and highlights the importance of players generating consistently central impact locations when hitting for optimal performance.

Staff review of 'Radioecological assessment of the Wyhl nuclear power plant': Analysis of the report prepared by the University of Heidelberg, West Germany. Draft summary report

International Nuclear Information System (INIS)

Congel, F.J.; Cardile, F.P.; Zalcman, B.; Pasciak, W.J.; Chu, A.

1980-06-01

The Heidelberg Report presents an assessment of the environmental radiological impact of a proposed pressurized-water reactor to be built near Wyhl, West Germany. The assessment is based largely on mathematical models that are used to calculate doses to humans in the area surrounding a reactor site and describe the movement of radioactive materials in the environment. These are the same mathematical models that are used by the U.S. Nuclear Regulatory Commission (NRC) in licensing reactors in the United States. The NRC uses these models to make sure that any radiation exposure due to a reactor is far below national and international recommended 'safe' levels, as well as below natural radiation levels. The NRC staff reviewed certain parts of the Heidelberg Report because the report implied that the NRC may be substantially underestimating doses to individuals living near nuclear power plants by using incorrect values for parameters in the mathematical models. Although the Heidelberg Report assessment is based largely on environmental models described in four NRC Regulatory Guides, the NRC staff's review of the Heidelberg Report indicates that the Heidelberg authors used values for some model parameters that are too high

Relation Between Hertz Stress-Life Exponent, Ball-Race Conformity, and Ball Bearing Life

Science.gov (United States)

Zaretsky, Erwin V.; Poplawski, Joseph V.; Root, Lawrence E.

2008-01-01

ANSI/ABMA and ISO standards based on Lundberg-Palmgren bearing life theory are normalized for ball bearings having inner- and outerrace conformities of 52 percent (0.52) and made from pre-1940 bearing steel. The Lundberg-Palmgren theory incorporates an inverse 9th power relation between Hertz stress and fatigue life for ball bearings. The effect of race conformity on ball set life independent of race life is not incorporated into the Lundberg-Palmgren theory. In addition, post-1960 vacuum-processed bearing steel exhibits a 12th power relation between Hertz stress and life. The work reported extends the previous work of Zaretsky, Poplawski, and Root to calculate changes in bearing life--that includes the life of the ball set--caused by race conformity, Hertz stress-life exponent, ball bearing type and bearing series. The bearing fatigue life in actual application will usually be equal to or greater than that calculated using the ANSI/ABMA and ISO standards that incorporate the Lundberg-Palmgren theory. The relative fatigue life of an individual race is more sensitive to changes in race conformity for Hertz stress-life exponent n of 12 than where n = 9. However, when the effects are combined to predict actual bearing life for a specified set of conditions and bearing geometry, the predicted life of the bearing will be greater for a value of n = 12 than n = 9.

Partial amorphization of an α-FeCr alloy by ball-milling

International Nuclear Information System (INIS)

Loureiro, J. M.; Costa, B. F. O.; Caer, G. Le; Delcroix, P.

2008-01-01

The structural changes of near-equiatomic α-FeCr alloys, ground in a vibratory mill in vacuum and in argon, were followed as a function of milling time. An amorphous phase forms in both cases but at a much faster rate when milling in argon than when milling in vacuum. Amorphisation by ball-milling of α-FeCr alloys is deduced to be an intrinsic phenomenon which is however speeded-up by oxygen. The amorphous phase crystallizes into a bcc Cr-rich phase and a bcc Fe-rich phase when annealed for short times.

Laboratory demonstration of ball lightning

International Nuclear Information System (INIS)

Egorov, Anton I; Stepanov, Sergei I; Shabanov, Gennadii D

2004-01-01

A common laboratory facility for creating glowing flying plasmoids akin to a natural ball lightning, allowing a number of experiments to be performed to investigate the main properties of ball lightning, is described. (methodological notes)

A systematic study of ball passing frequencies based on dynamic modeling of rolling ball bearings with localized surface defects

Science.gov (United States)

Niu, Linkai; Cao, Hongrui; He, Zhengjia; Li, Yamin

2015-11-01

Ball passing frequencies (BPFs) are very important features for condition monitoring and fault diagnosis of rolling ball bearings. The ball passing frequency on outer raceway (BPFO) and the ball passing frequency on inner raceway (BPFI) are usually calculated by two well-known kinematics equations. In this paper, a systematic study of BPFs of rolling ball bearings is carried out. A novel method for accurately calculating BPFs based on a complete dynamic model of rolling ball bearings with localized surface defects is proposed. In the used dynamic model, three-dimensional motions, relative slippage, cage effects and localized surface defects are all considered. Moreover, localized surface defects are modeled accurately with consideration of the finite size of the ball, the additional clearance due to material absence, and changes of contact force directions. The reasonability of the proposed method for the prediction of dynamic behaviors of actual ball bearings with localized surface defects and for the calculation of BPFs is discussed by investigating the motion characteristics of a ball when it rolls through a defect. Parametric investigation shows that the shaft speed, external loads, the friction coefficient, raceway groove curvature factors, the initial contact angle, and defect sizes have great effects on BPFs. For a loaded ball bearing, the combination of rolling and sliding in contact region occurs, and the BPFs calculated by simple kinematical relationships are inaccurate, especially for high speed, low external load, and large initial contact angle conditions where severe skidding occurs. The hypothesis that the percentage variation of the spacing between impulses in a defective ball bearing was about 1-2% reported in previous investigations can be satisfied only for the conditions where the skidding effect in a bearing is slight. Finally, the proposed method is verified with two experiments.

BALL - biochemical algorithms library 1.3

Directory of Open Access Journals (Sweden)

Stöckel Daniel

2010-10-01

Full Text Available Abstract Background The Biochemical Algorithms Library (BALL is a comprehensive rapid application development framework for structural bioinformatics. It provides an extensive C++ class library of data structures and algorithms for molecular modeling and structural bioinformatics. Using BALL as a programming toolbox does not only allow to greatly reduce application development times but also helps in ensuring stability and correctness by avoiding the error-prone reimplementation of complex algorithms and replacing them with calls into the library that has been well-tested by a large number of developers. In the ten years since its original publication, BALL has seen a substantial increase in functionality and numerous other improvements. Results Here, we discuss BALL's current functionality and highlight the key additions and improvements: support for additional file formats, molecular edit-functionality, new molecular mechanics force fields, novel energy minimization techniques, docking algorithms, and support for cheminformatics. Conclusions BALL is available for all major operating systems, including Linux, Windows, and MacOS X. It is available free of charge under the Lesser GNU Public License (LPGL. Parts of the code are distributed under the GNU Public License (GPL. BALL is available as source code and binary packages from the project web site at http://www.ball-project.org. Recently, it has been accepted into the debian project; integration into further distributions is currently pursued.

Ball Screw Actuator Including a Stop with an Integral Guide

Science.gov (United States)

Wingett, Paul T. (Inventor); Perek, John (Inventor); Geck, Kellan (Inventor)

2015-01-01

An actuator includes a housing assembly, a ball nut, a ball screw, and a ball screw stop. The ball nut is rotationally mounted in the housing assembly, is adapted to receive an input torque, and is configured, upon receipt thereof, to rotate and supply a drive force. The ball screw is mounted within the housing assembly and extends through the ball nut. The ball screw has a first end and a second end, and is coupled to receive the drive force from the ball nut. The ball screw is configured, upon receipt of the drive force, to selectively translate between a stow position and a deploy position. The ball screw stop is mounted on the ball screw to translate therewith and is configured to at selectively engage the housing assembly while the ball screw is translating, and engage the ball nut when the ball screw is in the deploy position.

The cultural heritage tourism in the city of Heidelberg, Germany: Plans, motivations and realities

Directory of Open Access Journals (Sweden)

Ferreira Pires Daniel Vítor

2014-01-01

Full Text Available In recent years, heritage has been responsible for the visibility that a large number of cities around the world have been getting as regards affirmation and differentiation of places. This also increased the number of cultural tourists that visit those cities worldwide. In this struggle for affirmation and differentiation, Heidelberg has quite an advantage, since the city's cultural heritage, as well as its unique atmosphere, have been spread by the Romantic Movement in the 19th century and it still happens nowadays, after more than two hundred years. But is Heidelberg indeed a city that receives cultural tourists? In this article, through an exploratory study, we intend to characterize the tourists that visit the city, to understand if the defined politics, actions and events taken by the different institutional authorities (like the Heidelberger Marketing and City Town hall, among others are getting the expected results. Through literature review and question­naires completed by the city's tourists, based on a probabilistic random sample and semi-structured interviews, we expect to trace the evolution of the policies defined, and compare those to the type of tourists that actually visit the city. As a preliminary result, we concluded that there is a difference between the tourist profile defined by the institutional authorities with responsibilities in the promotion and communication of the city's cultural heritage assets, comparing with the tourists that actually visit the city. This is the result not only of the motivations and effective length of the visits, but also in the lack of alternative or multiple visit narratives and routes for the cultural heritage city's assets.

Encapsulated Ball Bearings for Rotary Micro Machines

Science.gov (United States)

2007-01-01

occurrence as well as the overall tribological properties of the bearing mechanism. Firstly, the number of stainless steel balls influences not only the load...stacks.iop.org/JMM/17/S224 Abstract We report on the first encapsulated rotary ball bearing mechanism using silicon microfabrication and stainless steel balls...The method of capturing stainless steel balls within a silicon race to support a silicon rotor both axially and radially is developed for rotary micro

Deutsches Krebsforschungszentrum Heidelberg. Report on scientific results 2000-2001

International Nuclear Information System (INIS)

Metzler, H.

2002-01-01

The Deutsches Krebsforschungszentrum Heidelberg (DKFZ, German Cancer Research Center) publishes alternating every year the ''Wissenschaftlicher Ergebnisbericht'' (in German) and the ''Research Report'' (in English). Both volumes are reports on the present state of research activities of the DKFZ as a National Research Center to the funding federal and state authorities [Federal Republic of Germany, Land (state) Baden-Wuerttemberg]. Furthermore they shall inform colleagues and the scientifically interested public. Both reports are structured according to the center's eight research programs. The last Research Report was published in 2001. In Germany a new orthography has been accepted. Some authors used the new form others the traditional one. The orthography was not standardized. (orig.)

The crystallization of amorphous Fe2MnGe powder prepared by ball milling

International Nuclear Information System (INIS)

Zhang, L.; Brueck, E.; Tegus, O.; Buschow, K.H.J.; Boer, F.R. de

2003-01-01

We synthesized for the first time the intermetallic compound Fe 2 MnGe. To avoid preferential evaporation of volatile components we exploited mechanical alloying. Amorphous Fe 2 MnGe alloy powder was prepared by planetary ball milling elemental starting materials. The amorphous-to-crystalline transition was studied by means of differential scanning calorimetry (DSC) and X-ray diffraction (XRD). A cubic D0 3 phase is formed at low temperature and transforms to a high-temperature hexagonal D0 19 phase. The apparent activation energy was determined by means of the Kissinger method

Darmstadton hunting in the interaction $\\gamma$-crystal

CERN Document Server

2002-01-01

From several years, indications of the existence of sharp lines, presenting all features of light neutral particles, particles have been found in heavy ions-atoms interaction at the GSI (Darmstadt). \\\\\\\\ This experiment aims to produce these particles in $\\gamma-$interaction with the strong field of a crystal near the direction of an axis. \\\\\\\\ The small divergence tagged $\\gamma-$beam is obtained from a 150 GeV $e^{-}-$ beam. The angular measurements are performed by $\\mu-$strip detector, at large distance ($\\approx$80 m of vacuum pipe shielded against the earth's magnetic field). Energy measurements are performed by magnetic analysis and independently by lead glass calorimeters. \\\\\\\\The setup is fitted to the search of such particles in the lifetime ranges:\\\\ $[10^{-13} s > \\tau > 0.5 10^{-17}s]$ and $[10^{-9}s > \\tau > 10^{-13}s]$ \\\\\\\\ - In the first case (LL), the magnets Trim9 and Trim5 are not used, the particle decaying near the crystal will appear as a narrow peak over a large bump due to the pairs ...

Flight trajectory of a rotating golf ball with grooves

Science.gov (United States)

Baek, Moonheum; Kim, Jooha; Choi, Haecheon

2014-11-01

Dimples are known to reduce drag on a sphere by the amount of 50% as compared to a smooth surface. Despite the advantage of reducing drag, dimples deteriorate the putting accuracy owing to their sharp edges. To minimize this putting error but maintain the same flight distance, we have devised a grooved golf ball (called G ball hereafter) for several years. In this study, we modify the shape and pattern of grooves, and investigate the flow characteristics of the G ball by performing wind-tunnel experiments at the Reynolds numbers of 0 . 5 ×105 - 2 . 5 ×105 and the spin ratios (ratio of surface velocity to the free-stream velocity) of 0 - 0.6 that include the real golf-ball velocity and rotational speed. We measure the drag and lift forces on the rotating G ball and compare them with those of a smooth ball and two well-known dimpled balls. The lift-to-drag ratio of the G ball is much higher than that of a smooth ball and is in between those of the two dimpled balls. The trajectories of flying golf balls are computed. The flight distance of G ball is almost the same as that of one dimpled ball but slightly shorter than that of the other dimpled ball. The fluid-dynamic aspects of these differences will be discussed at the talk. Supported by 2011-0028032, 2014M3C1B1033980.

How does gravity save or kill Q-balls?

International Nuclear Information System (INIS)

Tamaki, Takashi; Sakai, Nobuyuki

2011-01-01

We explore stability of gravitating Q-balls with potential V 4 (φ)=(m 2 /2)φ 2 -λφ 4 +(φ 6 /M 2 ) via catastrophe theory, as an extension of our previous work on Q-balls with potential V 3 (φ)=(m 2 /2)φ 2 -μφ 3 +λφ 4 . In flat spacetime Q-balls with V 4 in the thick-wall limit are unstable and there is a minimum charge Q min , where Q-balls with Q min are nonexistent. If we take self-gravity into account, on the other hand, there exist stable Q-balls with arbitrarily small charge, no matter how weak gravity is. That is, gravity saves Q-balls with small charge. We also show how stability of Q-balls changes as gravity becomes strong.

Experimental research on ball lightning

International Nuclear Information System (INIS)

Ofuruton, H.; Ohtsuki, Y.H.

1990-01-01

Experiments on producing ball lightning were made with discharge in flammable gas and/or aerosol. A long lifetime (2 s) ball lightning was observed in 2.7 % ethane and 100 cm 3 cotton fibers, and in 1.5 % methane and 1.9 % ethane

Planetary physics research programme at the Facility for Antiprotons and Ion Research at Darmstadt

International Nuclear Information System (INIS)

Tahir, N.A.; Neumayer, P.; Bagnoud, V.; Lomonosov, I.V.; Borm, B.; Piriz, A.R.; Piriz, S.A.; Shutov, A.

2017-01-01

Planetary physics research is an important part of the high energy density (HED) physics programme at the Facility for Antiprotons and Ion Research (FAIR) at Darmstadt. In this paper, we report numerical simulations of a proposed experiment named LAboratory PLAnetary Sciences (LAPLAS). These simulations show that in such experiments, an Fe sample can be imploded to extreme physical conditions that are expected to exist in the interior of the Earth and in the interior of more massive rocky planets named, super-Earths. The LAPLAS experiments will thus provide very valuable information on the equation-of-state (EOS) and transport properties of HED Fe, which will help the scientists to understand the structure and evolution of the planets in our solar system and of the extrasolar system planets. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Planetary physics research programme at the Facility for Antiprotons and Ion Research at Darmstadt

Energy Technology Data Exchange (ETDEWEB)

Tahir, N.A.; Neumayer, P.; Bagnoud, V. [Department of Plasma Physics, GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany); Lomonosov, I.V. [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka (Russian Federation); Tomsk University, Tomsk (Russian Federation); Lomonosov Moscow State University, Moscow (Russian Federation); Moscow Institute of Physics and Technology, Dolgoprudny (Russian Federation); Borm, B. [Department of Physics, Goethe-Universitaet Frankfurt, Frankfurt (Germany); Piriz, A.R.; Piriz, S.A. [E.T.S.I. Industrials, University of Castilla-La Mancha, Ciudad Real (Spain); Shutov, A. [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka (Russian Federation)

2017-11-15

Planetary physics research is an important part of the high energy density (HED) physics programme at the Facility for Antiprotons and Ion Research (FAIR) at Darmstadt. In this paper, we report numerical simulations of a proposed experiment named LAboratory PLAnetary Sciences (LAPLAS). These simulations show that in such experiments, an Fe sample can be imploded to extreme physical conditions that are expected to exist in the interior of the Earth and in the interior of more massive rocky planets named, super-Earths. The LAPLAS experiments will thus provide very valuable information on the equation-of-state (EOS) and transport properties of HED Fe, which will help the scientists to understand the structure and evolution of the planets in our solar system and of the extrasolar system planets. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Q-balls in flat potentials

International Nuclear Information System (INIS)

Copeland, Edmund J.; Tsumagari, Mitsuo I.

2009-01-01

We study the classical and absolute stability of Q-balls in scalar field theories with flat potentials arising in both gravity-mediated and gauge-mediated models. We show that the associated Q-matter formed in gravity-mediated potentials can be stable against decay into their own free particles as long as the coupling constant of the nonrenormalizable term is small, and that all of the possible three-dimensional Q-ball configurations are classically stable against linear fluctuations. Three-dimensional gauge-mediated Q-balls can be absolutely stable in the thin-wall limit, but are completely unstable in the thick-wall limit.

Annual report of the working group 'fuel pin and fuel element mechanics' of the Institut fuer Reaktortechnik (IRT) of the Technische Hochschule Darmstadt for the Fast Breeder Project

International Nuclear Information System (INIS)

Fabian, H.; Humbach, W.; Lassmann, K.; Mueller, J.J.; Preusser, T.; Schmelz, K.

1978-09-01

This report comprises six single lectures given at an information meeting organized by the Institut fuer Reaktortechnik der Technischen Hochschule Darmstadt (IRT) in Darmstadt on April 24, 1978. The lectures are an account of work performed at IRT on the mechanics of fuel pins and fuel elements and supported by the Fast Breeder Project (PSB) of KfK. These activities can be broken down into studies of the integral fuel pin (URANUS computer code) and into multidimensional studies of the fuel pin using the finite-element method (FINEL and ZIDRIG computer codes). Moreover, a report is presented of the status of the test facility for simulation of out-of-pile cladding tube loads and of the IRT project on the simulation and analysis of radiation damage. (orig./GL) [de

LHC gets the ball rolling

CERN Multimedia

2007-01-01

1. The multidisciplinary team responsible for the RF ball project to check the interconnections. From left to right: Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS), Marek Gasior (AB/BI).2. During the tests the ball is inserted very carefully into the vacuum chamber.1. Le groupe pluridisciplinaire qui a mené le projet de balle RF pour vérifier les interconnexions avec, de gauche à droite, Rhodri Jones (AB/BI), Eva Calvo (AB/BI), Francesco Bertinelli (AT/MCS), Sonia Bartolome Jimenez (TS/IC), Sylvain Weisz (TS/IC), Paul Cruikshank (AT/VAC), Willemjan Maan (AT/VAC), Alain Poncet (AT/MCS) et Marek Gasior (AB/BI).2. Lors des tests, la balle est insérée dans la chambre à vide avec beaucoup de précaution.

Heidelberg Neuro-Music Therapy for chronic-tonal tinnitus - treatment outline and psychometric evaluation.

Science.gov (United States)

Argstatter, Heike; Grapp, Miriam; Plinkert, Peter K; Bolay, Hans Volker

2012-01-01

Musical training positively influences the cortical plasticity of the brain and has proven to be effective in treating chronic tinnitus. A neuro-music therapy concept, the "Heidelberg Neuro-Music Therapy" treatment was developed and evaluated. A prospective, cross-sectional design was used. N = 135 patients (mean age 47 years) with chronic, tonal tinnitus attended a standardized protocol for Neuro-Music Therapy (either "standard therapy" ST or "compact therapy" CT). The results were compared to a cognitive behavioral placebo music therapy procedure (PT). Tinnitus distress was assessed using the German version of the Tinnitus-Questionnaire (TQ) at admission, at discharge and six months after therapy. Changes were assessed statistically and by means of clinical significance. TQ scores significantly improved - independent of group allocation. But more than 80% of the music therapy patients (both ST and CT) revealed a reliable improvement ("responder") compared to 44% in the PT group. Therapy impact seems to be lasting since TQ scores remained stable until follow-up at six months. The "Heidelberg Neuro-Music Therapy" is a method with fast onset and long lasting effect for patients with "tonal" tinnitus. A number of potential working factors accounting for the treatment success are highlighted.

Characterization of PbWO4 crystals for high-energy physics experiments

Science.gov (United States)

Kim, M. J.; Park, H.; Kim, H. J.

2016-09-01

High-energy physics (HEP) experiments have employed many new types of scintillators. Specifically, bismuth germanate, thallium-doped cesium iodide, and lead tungstate (PbWO4, PWO) have been used for the L3 experiment; CLEO II, Belle and BES-III; and CMS, respectively. PWO has particularly beneficial properties, such as high density, fast decay time, short radiation length and radiation hardness. In this study, we tested the PWO crystals at low temperatures to determine their applicability in future calorimeters. Various crystals from the Proton Antiproton Annihilations at Darmstadt (PANDA) experiment in Giessen, the Bogoroditsk Techno-Chemical Plant (BTCP) in Russia and by Shanghai Institute of Ceramics, Chinese Academy of Sciences (SICCAS) in China were investigated. We studied the scintillation properties of PWO crystals, such as their X-ray luminescence, relative light yields, absolute light yields, energy resolutions, decay times and longitudinal uniformities of their light yields. In addition, we measured the temperature dependences of the light yields and decay times by using a 137Cs γ-ray source. The emission spectra of the PWO crystals consisted of a broad band from 350 nm to 700 nm, and the peak emission wavelength in each spectrum was 420 nm. The emission spectra of the PWO crystals from SICCAS were slightly shifted to longer wavelengths compared with those of the crystals from the other institutions.

Static Load Distribution in Ball Bearings

Science.gov (United States)

Ricci, Mario

2010-01-01

A numerical procedure for computing the internal loading distribution in statically loaded, single-row, angular-contact ball bearings when subjected to a known combined radial and thrust load is presented. The combined radial and thrust load must be applied in order to avoid tilting between inner and outer rings. The numerical procedure requires the iterative solution of Z + 2 simultaneous nonlinear equations - where Z is the number of the balls - to yield an exact solution for axial and radial deflections, and contact angles. Numerical results for a 218 angular-contact ball bearing have been compared with those from the literature and show significant differences in the magnitudes of the ball loads, contact angles, and the extent of the loading zone.

Multifractal properties of ball milling dynamics

Energy Technology Data Exchange (ETDEWEB)

Budroni, M. A., E-mail: mabudroni@uniss.it; Pilosu, V.; Rustici, M. [Dipartimento di Chimica e Farmacia, Università degli Studi di Sassari, Via Vienna 2, Sassari 07100 (Italy); Delogu, F. [Dipartimento di Ingegneria Meccanica, Chimica, e dei Materiali, Università degli Studi di Cagliari, via Marengo 2, Cagliari 09123 (Italy)

2014-06-15

This work focuses on the dynamics of a ball inside the reactor of a ball mill. We show that the distribution of collisions at the reactor walls exhibits multifractal properties in a wide region of the parameter space defining the geometrical characteristics of the reactor and the collision elasticity. This feature points to the presence of restricted self-organized zones of the reactor walls where the ball preferentially collides and the mechanical energy is mainly dissipated.

Aerodynamic drag of modern soccer balls.

Science.gov (United States)

Asai, Takeshi; Seo, Kazuya

2013-12-01

Soccer balls such as the Adidas Roteiro that have been used in soccer tournaments thus far had 32 pentagonal and hexagonal panels. Recently, the Adidas Teamgeist II and Adidas Jabulani, respectively having 14 and 8 panels, have been used at tournaments; the aerodynamic characteristics of these balls have not yet been verified. Now, the Adidas Tango 12, having 32 panels, has been developed for use at tournaments; therefore, it is necessary to understand its aerodynamic characteristics. Through a wind tunnel test and ball trajectory simulations, this study shows that the aerodynamic resistance of the new 32-panel soccer ball is larger in the high-speed region and lower in the middle-speed region than that of the previous 14- and 8-panel balls. The critical Reynolds number of the Roteiro, Teamgeist II, Jabulani, and Tango 12 was ~2.2 × 10(5) (drag coefficient, C d  ≈ 0.12), ~2.8 × 10(5) (C d  ≈ 0.13), ~3.3 × 10(5) (C d  ≈ 0.13), and ~2.4 × 10(5) (C d  ≈ 0.15), respectively. The flight trajectory simulation suggested that the Tango 12, one of the newest soccer balls, has less air resistance in the medium-speed region than the Jabulani and can thus easily acquire large initial velocity in this region. It is considered that the critical Reynolds number of a soccer ball, as considered within the scope of this experiment, depends on the extended total distance of the panel bonds rather than the small designs on the panel surfaces.

On the formation of ball lightning

International Nuclear Information System (INIS)

Silberg, P.A.

1981-01-01

A plasma continuum model for the formation of ball lightning is developed based on a substantial number of reports that the ball is often in the discharge column of a previous lightning stroke. The usual method of setting up the plasma equation for a one-component electron plasma is used. An approximate equation for the plasma is derived from the describing equation which is then solved exactly in terms of the Jacobi elliptic functions. The formation of the ball is based on a nonlinearity of the plasma equation which uner certain circumstances permits the field to collapse into a small region. This collapse is interpreted to be ball lightning. The approximate equation derived for the plasma has the same form as a previous equation used to describe the formation of the fireball plasma. (author)

Crystallographic alignment evolution and magnetic properties of anisotropic Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes prepared by surfactant-assisted ball milling

Energy Technology Data Exchange (ETDEWEB)

Xu, M.L.; Wu, Q.; Li, Y.Q.; Liu, W.Q.; Lu, Q.M.; Yue, M., E-mail: yueming@bjut.edu.cn

2015-08-01

The microstructure, crystal structure and magnetic properties were studied for Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes prepared by surfactant-assisted high-energy ball milling (SAHEBM). Effect of ball-milling time on the c-axis crystallographic alignment, morphology and magnetic properties of Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes was systematically investigated. With increasing milling time from 1 h to 7 h, the intensity ratio between (002) and (111) reflection peaks indicating degree of c-axis crystal texture of the (Sm, Pr)Co{sub 5} phase increases first, peaks at 3 h, then drops again, revealing that the strongest c-axis crystal texture was obtained in the nanoflakes milled for 3 h. On the other hand, the coercivity (H{sub ci}) of the flakes increases gradually from 1.71 to 14.65 kOe with the increase of ball milling time. As a result, an optimal magnetic properties of M{sub r} of 10.23 kGs, H{sub ci} of 11.45 kOe and (BH){sub max} of 24.40 MGOe was obtained in Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes milled for 3 h, which also displayed a high aspect ratio, small in-plane size, pronounced (001) out-of-plane texture. - Highlights: • Anisotropic Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes with strong c-axis texture were prepared. • Effects of ball-milling time on structure and magnetic properties were studied. • (BH){sub max} value of Sm{sub 0.6}Pr{sub 0.4}Co{sub 5} nanoflakes is larger than that of SmCo{sub 5} nanoflakes.

Apparatus Would Measure Temperatures Of Ball Bearings

Science.gov (United States)

Gibson, John C.; Fredricks, Thomas H.

1995-01-01

Rig for testing ball bearings under radial and axial loads and measuring surface temperatures undergoing development. Includes extensible thermocouples: by means of bellows as longitudinal positioners, thermocouples driven into contact with bearing balls to sense temperatures immediately after test run. Not necessary to disassemble rig or to section balls to obtain indirect indications of maximum temperatures reached. Thermocouple measurements indicate temperatures better than temperature-sensitive paints.

Ball Screw Actuator Including an Axial Soft Stop

Science.gov (United States)

Wingett, Paul T. (Inventor); Forrest, Steven Talbert (Inventor); Abel, Steve (Inventor); Woessner, George (Inventor); Hanlon, Casey (Inventor)

2016-01-01

An actuator includes an actuator housing, a ball screw, and an axial soft stop assembly. The ball screw extends through the actuator housing and has a first end and a second end. The ball screw is coupled to receive a drive force and is configured, upon receipt of the drive force, to selectively move in a retract direction and an extend direction. The axial soft stop assembly is disposed within the actuator housing. The axial soft stop assembly is configured to be selectively engaged by the ball screw and, upon being engaged thereby, to translate, with compliance, a predetermined distance in the extend direction, and to prevent further movement of the ball screw upon translating the predetermined distance.

Berkeley High-Resolution Ball

International Nuclear Information System (INIS)

Diamond, R.M.

1984-10-01

Criteria for a high-resolution γ-ray system are discussed. Desirable properties are high resolution, good response function, and moderate solid angle so as to achieve not only double- but triple-coincidences with good statistics. The Berkeley High-Resolution Ball involved the first use of bismuth germanate (BGO) for anti-Compton shield for Ge detectors. The resulting compact shield permitted rather close packing of 21 detectors around a target. In addition, a small central BGO ball gives the total γ-ray energy and multiplicity, as well as the angular pattern of the γ rays. The 21-detector array is nearly complete, and the central ball has been designed, but not yet constructed. First results taken with 9 detector modules are shown for the nucleus 156 Er. The complex decay scheme indicates a transition from collective rotation (prolate shape) to single- particle states (possibly oblate) near spin 30 h, and has other interesting features

Modeling and Analyzing the Slipping of the Ball Screw

Directory of Open Access Journals (Sweden)

Nannan Xu

Full Text Available AbstractThis paper aims to set up the ball systematic slipping model and analyze the slipping characteristics caused by different factors for a ball screw operating at high speeds. To investigate the ball screw slipping mechanism, transformed coordinate system should be established firstly. Then it is used to set up mathematical modeling for the ball slipping caused by the three main reasons and the speed of slipping can be calculated. Later, the influence of the contact angle, helix angle and screw diameter for ball screw slipping will be analyzed according to the ball slipping model and slipping speeds equation and the slipping analysis will be obtained. Finally, curve of slipping analysis and that of mechanical efficiency of the ball screw analysis by Lin are compared, which will indirectly verify the correctness of the slipping model. The slipping model and the curve of slipping analysis established in this paper will provide theory basis for reducing slipping and improving the mechanical efficiency of a ball screw operating at high speeds.

Mucormycosis (Mucor fungus ball) of the maxillary sinus.

Science.gov (United States)

Cho, Hang Sun; Yang, Hoon Shik; Kim, Kyung Soo

2014-01-01

A fungus ball is an extramucosal fungal proliferation that completely fills one or more paranasal sinuses and usually occurs as a unilateral infection. It is mainly caused by Aspergillus spp in an immunocompetent host, but some cases of paranasal fungal balls reportedly have been caused by Mucor spp. A Mucor fungus ball is usually found in the maxillary sinus and/or the sphenoid sinus and may be black in color. Patients with mucormycosis, or a Mucor fungal ball infection, usually present with facial pain or headache. On computed tomography, there are no pathognomonic findings that are conclusive for a diagnosis of mucormycosis. In this article we report a case of mucormycosis in a 56-year-old woman and provide a comprehensive review of the literature on the "Mucor fungus ball." To the best of our knowledge, 5 case reports (8 patients) have been published in which the fungus ball was thought to be caused by Mucor spp.

Dimensions of the foveal avascular zone using the Heidelberg retinal angiogram-2 in normal eyes

Directory of Open Access Journals (Sweden)

John Deepa

2011-01-01

Full Text Available Purpose: The purpose was to study the dimensions of the foveal avascular zone (FAZ using Heidelberg Retinal Angiogram-2 (HRA-2; Heidelberg Engineering GmBH, Dossenheim, Germany. Materials and Methods: An observational study of the FAZ area and circumference was done with fundus fluorescein angiography (FFA using HRA-2 in 31 normal individuals. The FAZ was studied using both contrast-adjusted and nonadjusted methods. Contrast adjustment was done to obtain better visualization of the finer capillaries around the fovea enabling more precise measurements of the FAZ in normal eyes. Results: The mean area of the FAZ calculated by the contrast-adjusted method was 0.2753 mm 2 (±0.074 and the mean circumference was 2.22 mm (±0.048. By the conventional method, the area and circumference of the FAZ were 0.6241 mm 2 (±0.177 and 3.23 mm (±0.454, respectively. Conclusion: The measurements of area and circumference of FAZ using contrast-adjusted methods were significantly smaller than the conventional method.

Aerodynamics in the classroom and at the ball park

Science.gov (United States)

Cross, Rod

2012-04-01

Experiments suitable for classroom projects or demonstrations are described concerning the aerodynamics of polystyrene balls. A light ball with sufficient backspin can curve vertically upward through the air, defying gravity and providing a dramatic visual demonstration of the Magnus effect. A ball projected with backspin can also curve downward with a vertical acceleration greater than that due to gravity if the Magnus force is negative. These effects were investigated by filming the flight of balls projected in an approximately horizontal direction so that the lift and drag forces could be easily measured. The balls were also fitted with artificial raised seams and projected with backspin toward a vertical target in order to measure the sideways deflection over a known horizontal distance. It was found that (a) a ball with a seam on one side can deflect either left or right depending on its launch speed and (b) a ball with a baseball seam can also deflect sideways even when there is no sideways component of the drag or lift forces acting on the ball. Depending on the orientations of the seam and the spin axis, a sideways force on a baseball can arise either if there is rough patch on one side of the ball or if there is a smooth patch. A scuff ball with a rough patch on one side is illegal in baseball. The effect of a smooth patch is a surprising new observation.

Effect of soccer shoe upper on ball behaviour in curve kicks

Science.gov (United States)

Ishii, Hideyuki; Sakurai, Yoshihisa; Maruyama, Takeo

2014-08-01

New soccer shoes have been developed by considering various concepts related to kicking, such as curving a soccer ball. However, the effects of shoes on ball behaviour remain unclear. In this study, by using a finite element simulation, we investigated the factors that affect ball behaviour immediately after impact in a curve kick. Five experienced male university soccer players performed one curve kick. We developed a finite element model of the foot and ball and evaluated the validity of the model by comparing the finite element results for the ball behaviour immediately after impact with the experimental results. The launch angle, ball velocity, and ball rotation in the finite element analysis were all in general agreement with the experimental results. Using the validated finite element model, we simulated the ball behaviour. The simulation results indicated that the larger the foot velocity immediately before impact, the larger the ball velocity and ball rotation. Furthermore, the Young's modulus of the shoe upper and the coefficient of friction between the shoe upper and the ball had little effect on the launch angle, ball velocity, and ball rotation. The results of this study suggest that the shoe upper does not significantly influence ball behaviour.

How does gravity save or kill Q-balls?

OpenAIRE

Tamaki, Takashi; Sakai, Nobuyuki

2011-01-01

We explore stability of gravitating Q-balls with potential $V_4(\\phi)={m^2\\over2}\\phi^2-\\lambda\\phi^4+\\frac{\\phi^6}{M^2}$ via catastrophe theory, as an extension of our previous work on Q-balls with potential $V_3(\\phi)={m^2\\over2}\\phi^2-\\mu\\phi^3+\\lambda\\phi^4$. In flat spacetime Q-balls with $V_4$ in the thick-wall limit are unstable and there is a minimum charge $Q_{{\\rm min}}$, where Q-balls with $Q

Friction torque in thrust ball bearings grease lubricated

Science.gov (United States)

Ianuş, G.; Dumitraşcu, A. C.; Cârlescu, V.; Olaru, D. N.

2016-08-01

The authors investigated experimentally and theoretically the friction torque in a modified thrust ball bearing having only 3 balls operating at low axial load and lubricated with NGLI-00 and NGLI-2 greases. The experiments were made by using spin-down methodology and the results were compared with the theoretical values based on Biboulet&Houpert's rolling friction equations. Also, the results were compared with the theoretical values obtained with SKF friction model adapted for 3 balls. A very good correlation between experiments and Biboulet_&_Houpert's predicted results was obtained for the two greases. Also was observed that the theoretical values for the friction torque calculated with SKF model adapted for a thrust ball bearing having only 3 balls are smaller that the experimental values.

Laser Sintering Technology and Balling Phenomenon.

Science.gov (United States)

Oyar, Perihan

2018-02-01

The aim of this review was to evaluate the balling phenomenon which occurs typically in Selective Laser Sintering (SLS). The balling phenomenon is a typical SLS defect, and observed in laser sintered powder, significantly reduces the quality of SLS, and hinders the further development of SLS Technology. Electronic database searches were performed using Google Scholar. The keywords "laser sintering, selective laser sintering, direct metal laser melting, and balling phenomenon" were searched in title/abstract of publications, limited to December 31, 2016. The inclusion criteria were SLS, balling phenomenon, some alloys (such as Cr-Co, iron, stainless steel, and Cu-based alloys) mechanical properties, microstructure and bond strength between metal-ceramic crown, laboratory studies, full text, and in English language. A total of 100 articles were found the initial search and yielded a total of 50 studies, 30 of which did not fulfill the inclusion criteria and were therefore excluded. In addition, 20 studies were found by screening the reference list of all included publications. Finally, 40 studies were selected for this review. The method in question is regulated by powder material characteristics and the conditions of laser processing. The procedure of formation, affecting factors, and the mechanism of the balling effect are very complex.

THE BEHAVIOURAL REACTION OF WEANERS TO HANGING TOYS: WOODEN BALL AND AROMATIZED WOODEN BALL – WAY TO REDUCE AGGRESSION AFTER MIXING

Directory of Open Access Journals (Sweden)

Jacek NOWICKI

2008-05-01

Full Text Available The behaviour of weaners after mixing housed in pens equipped with hanging wooden ball, aromatized with vanilla fluid hanging wooden ball and without enrichment was evaluated. It was found that both enrichments reduced aggression, however the most interesting for weaners was the aromatized wooden ball.

Conceptual design of ball-screw type control element drive mechanism

Energy Technology Data Exchange (ETDEWEB)

Kim, Ji Ho; Kim, Jong In; Huh, Hyung [Korea Atomic Energy Research Institute, Taejon (Korea)

1999-10-01

In this report, the design features of ball-screw type CEDM with fine-step movement capability are described. The contents of this report are as follows: -Review of Design Requirements for Ball-screw type CEDM -System Description for Ball-screw type CEDM -Design of Ball Bearing and Ball-screw Assembly -Detail Design of Rotary Step Motor -Detail Design of Angular Position Indicator -Materials. The Ball-screw type CEDM described in this report is to be utilized as the starting point for design development of CEDM for SMART. 11 refs., 43 figs., 3 tabs. (Author)

Two Balls' Collision of Mass Ratio 3:1

Science.gov (United States)

Ogawara, Yasuo; Hull, Michael M.

2018-04-01

Students will sometimes ask why momentum and kinetic energy concepts are both necessary. When physics teachers demonstrate situations that require both an understanding of kinetic energy and momentum, a favorite is Newton's cradle, or a comparable demonstration of two balls of equal mass hitting each other. However, in addition to the case of two balls of equal mass, if a ball hits another ball of three times the mass with equal speed, the results are also interesting, and, like the equal-mass demonstration, both kinetic energy and momentum are critical for understanding the motion.

Biomechanics of Heading a Soccer Ball: Implications for Player Safety

Directory of Open Access Journals (Sweden)

Charles F. Babbs

2001-01-01

Full Text Available To better understand the risk and safety of heading a soccer ball, the author created a set of simple mathematical models based upon Newton�s second law of motion to describe the physics of heading. These models describe the player, the ball, the flight of the ball before impact, the motion of the head and ball during impact, and the effects of all of these upon the intensity and the duration of acceleration of the head. The calculated head accelerations were compared to those during presumably safe daily activities of jumping, dancing, and head nodding and also were related to established criteria for serious head injury from the motor vehicle crash literature. The results suggest heading is usually safe but occasionally dangerous, depending on key characteristics of both the player and the ball. Safety is greatly improved when players head the ball with greater effective body mass, which is determined by a player�s size, strength, and technique. Smaller youth players, because of their lesser body mass, are more at risk of potentially dangerous headers than are adults, even when using current youth size balls. Lower ball inflation pressure reduces risk of dangerous head accelerations. Lower pressure balls also have greater “touch” and “playability”, measured in terms of contact time and contact area between foot and ball during a kick. Focus on teaching proper technique, the re-design of age-appropriate balls for young players with reduced weight and inflation pressure, and avoidance of head contact with fast, rising balls kicked at close range can substantially reduce risk of subtle brain injury in players who head soccer balls.

Heidelberg’s relevance for a postmodern age: The doctrine of Scripture in the Heidelberg Catechism revisited

NARCIS (Netherlands)

van Vlastuin, W.

2015-01-01

The debate on the doctrine of Scripture is ongoing. In this article, the use of Scripture is investigated in the Heidelberg Catechism, a catechism in which there is no explicit statement about Scripture, the notion of the Word refers to the preached Word, and the focus is placed on soteriology and

Deutsches Krebsforschungszentrum Heidelberg (DKFZ). Report on scientific results 1998/1999

International Nuclear Information System (INIS)

Metzler, H.

2000-01-01

The Deutsches Krebsforschungszentrum Heidelberg (DKFZ, German Cancer Research Center) publishes alternating every year the 'Wissenschaftlicher Ergebnisbericht' (in German) and the 'Research Report' (in English). Both volumes are reports on the present state of research activities of the DKFZ as a National Research Center to the funding federal and state authorities (Federal Republic of Germany, Land (state) Baden-Wuerttemberg). Furthermore, they shall inform colleagues and the scientifically interested public. Both reports are structured according to the center's eight research programs. The next Research Report will be published in 2001. In Germany a new orthography has been accepted. Some authors used the new form others the traditional one. The orthography was not standardized. (orig.) [de

Darmstadt colloquium on hydrological engineering 1999: flow and dispersion processes in aquatic interstitials; Darmstaedter Wasserbauliches Kolloquium 1999: Fliess- und Ausbreitungsvorgaenge in aquatischen Grenzraeumen

Energy Technology Data Exchange (ETDEWEB)

NONE

2000-07-01

Anthropogenic effects have changed the patterns and intensities of pollutant transport into soil, groundwater and surface water, and water management has become a metter of great importance in the field of tension between water use and sustainability. Especially aquatic interstitials have great influence on environmental transport. The Darmstaedter Wasserbauliches Kolloquium (DAWAKO) 1999, which was held by the Institute of Hydrological Engineering and Water Management of TU Darmstadt University, discussed recent developments in the interstitials between unsaturated soil and groundwater, groundwater and flowing water, flowing water and floor. [German] Als Folge anthropogener Eingriffe in den Wasserkreislauf, z.B. infolge Landnutzungsaenderungen, Gewaesserausbau, Sieldungstaetigkeit usw. haben sich die Art und die Intensitaet des Stoffeintrages in Boden, Grundwasser sowie in die Oberflaechengewaesser erheblich gewandelt. Entsprechend sind zahlreiche wasserwirtschaftliche Fragestellungen im Spannungsfeld zwischen steigenden Anspruechen bei der Wassernutzung und dem Gebot einer nachhaltigen Bewirtschaftung dieser begrenzten Ressource zu behandeln. Es ist bekannt, dass aufgrund der periodisch wechselnden Milieubedingungen gerade den aquatischen Grenzraeumen eine besondere Bedeutung fuer den Stoffhaushalt zukommt. Neuere Entwicklungen bei den Prozessuntersuchungen in den Grenzraeumen zwischen: - ungesaettigter Bodenzone und Grundwasser - Grundwasser und Fliessgewaesser - Fliessgewaesser und Sohle (Interstitial) standen im Mittelpunkt des diesjaehrigen Darmstaedter Wasserbaulichen Kolloquiums (DAWAKO), das am 14. und 15. Oktober 1999 vom Institut fuer Wasserbau und Wasserwirtschaft der TU Darmstadt veranstaltet wurde. (orig.)

On longevity of I-ball/oscillon

Energy Technology Data Exchange (ETDEWEB)

Mukaida, Kyohei [Kavli IPMU (WPI), UTIAS, The University of Tokyo,Kashiwa, Chiba 277-8583 (Japan); Takimoto, Masahiro [Theory Center, KEK,1-1 Oho, Tsukuba, Ibaraki 305-0801 (Japan); Department of Particle Physics and Astrophysics, Weizmann Institute of Science,Rehovot 7610001 (Israel); Yamada, Masaki [Institute of Cosmology, Department of Physics and Astronomy, Tufts University,Medford, MA 02155 (United States); Department of Physics, Tohoku University,Sendai, Miyagi 980-8578 (Japan)

2017-03-23

We study I-balls/oscillons, which are long-lived, quasi-periodic, and spatially localized solutions in real scalar field theories. Contrary to the case of Q-balls, there is no evident conserved charge that stabilizes the localized configuration. Nevertheless, in many classical numerical simulations, it has been shown that they are extremely long-lived. In this paper, we clarify the reason for the longevity, and show how the exponential separation of time scales emerges dynamically. Those solutions are time-periodic with a typical frequency of a mass scale of a scalar field. This observation implies that they can be understood by the effective theory after integrating out relativistic modes. We find that the resulting effective theory has an approximate global U(1) symmetry reflecting an approximate number conservation in the non-relativistic regime. As a result, the profile of those solutions is obtained via the bounce method, just like Q-balls, as long as the breaking of the U(1) symmetry is small enough. We then discuss the decay processes of the I-ball/oscillon by the breaking of the U(1) symmetry, namely the production of relativistic modes via number violating processes. We show that the imaginary part is exponentially suppressed, which explains the extraordinary longevity of I-ball/oscillon. In addition, we find that there are some attractor behaviors during the evolution of I-ball/oscillon that further enhance the lifetime. The validity of our effective theory is confirmed by classical numerical simulations. Our formalism may also be useful to study condensates of ultra light bosonic dark matter, such as fuzzy dark matter, and axion stars, for instance.

A general theory for ball lightning structure and light output

Science.gov (United States)

Morrow, R.

2018-03-01

A general theory for free-floating ball lightning is presented which unifies the phantom plasma ball theory involving the production of very little light, with theories for ball lightning involving light output produced by burning particles from the soil. The mechanism for the formation of plasma balls is shown to be quite general, producing very similar plasma balls independent of initial ion densities over four orders of magnitude. All that is required is an excess of positive ions in the initial ball of ions. The central plasma density after 1 s is shown to be the reciprocal of the ion neutralization coefficient for all cases, both analytically and computationally. Further, the plasma region has zero electric field in all cases. Surrounding the plasma ball is a sphere of positive ions moving away from the centre via their own space-charge field; this space-charge field, which is the same in all cases near the plasma ball, drives negative ions and negative particles towards the plasma centre. The connection with burning particle theories is the proposition that the burning particles are highly-charged which is very likely after a lightning strike. Burning negatively charged particles would be driven into the plasma ball region and trapped while any positively charged particles would be driven away. The plasma ball structure is shown to last more than 10 s and the ‘burnout time’ for a typical coal particle (as an example) has been measured at 5-10 s this is comparable with the lifetimes observed for ball lightning. The light output from a few hundred particles is estimated to be ~1 W, a typical output for ball lightning. Finally, suggestions are made for the generation of ball lightning in the laboratory.

Estimating Wear Of Installed Ball Bearings

Science.gov (United States)

Keba, John E.; Mcvey, Scott E.

1993-01-01

Simple inspection and measurement technique makes possible to estimate wear of balls in ball bearing, without removing bearing from shaft on which installed. To perform measurement, one observes bearing cage while turning shaft by hand to obtain integral number of cage rotations and to measure, to nearest 2 degrees, number of shaft rotations producing cage rotations. Ratio between numbers of cages and shaft rotations depends only on internal geometry of bearing and applied load. Changes in turns ratio reflect changes in internal geometry of bearing provided measurements made with similar bearing loads. By assuming all wear occurs on balls, one computes effective value for this wear from change in turns ratio.

Ball-and-socket ankle joint

International Nuclear Information System (INIS)

Pistoia, F.; Ozonoff, M.B.; Wintz, P.; Hartford Hospital, CT

1987-01-01

The ball-and-socket ankle joint is a malformation of the ankle in which the articular surface of the talus is hemispherical in both the anteroposterior and lateral projections and has a congruent, concave tibial articular surface. Fourteen patients with this condition were identified retrospectively. Thirteen patients were thought to have the congenital type of ball-and-socket ankle joint which in many was associated with tarsal coalition, short limb, and ray fusion and deletion anomalies. One case of the acquired type, demonstrating less geometric rounding of the talar margins, was seen in a patient with myelomeningocele, probably resulting from sensory and motor deficits. Although the exact etiology of the congenital type is unknown, its association with other malformations suggests that the ball-and-socket ankle joint results from an overall maldevelopment of the ankle and foot. (orig.)

Effect of Various Inoculum Levels of Multidrug-Resistant Salmonella enterica Serovar Heidelberg (2011 Ground Turkey Outbreak Isolate on Cecal Colonization, Dissemination to Internal Organs, and Deposition in Skeletal Muscles of Commercial Turkeys after Experimental Oral Challenge

Directory of Open Access Journals (Sweden)

Divek V. T. Nair

2018-01-01

Full Text Available Salmonella enterica serovar Heidelberg (S. Heidelberg is a major foodborne pathogen colonizing poultry. The pathogen is associated with a significant number of foodborne outbreaks through contaminated poultry meat, including turkeys. Recently, multidrug-resistant (MDR strains of S. Heidelberg have emerged as a threat to human public health in the United States. The objective of this study was to determine the cecal colonization, dissemination to internal organs, and the potential for skeletal muscle deposition of an MDR S. Heidelberg isolate from the 2011 ground turkey outbreak in the United States after the experimental oral challenge of poults (young turkeys and adult turkey hens. In the poult study, two separate experiments using day-old, straight-run, commercial hybrid converter poults were randomly assigned to five challenge groups (0, 10∧2, 10∧4, 10∧6, 10∧8 CFU groups; 12 poults/group; N = 60/experiment and a week after, treatment groups were challenged separately with 0-, 2-, 4-, 6-, and 8- log10 CFU of S. Heidelberg orally. After 14 days post-challenge, the poults were euthanized, and samples were collected to determine MDR S. Heidelberg colonization in the cecum, dissemination to liver and spleen, and deposition in the thigh, drumstick, and breast muscles. A similar experimental design was followed for the adult turkey hens. In two separate experiments, 11-week-old commercial Hybrid Converter turkey hens (4 hens/group; N = 20/experiment were challenged with MDR S. Heidelberg and on day 16 post-challenge, birds were euthanized and samples were collected to determine Salmonella populations in the samples. The results indicated that, in turkey poults, the recovery of MDR S. Heidelberg was highest in the cecum followed by spleen, liver, thigh, drumstick, and breast. All tested inoculum levels resulted in more than 3.5 log10 CFU/g colonization in the poult cecum. The cecal colonization, dissemination to internal organs, and tissue

Transformation of Goethite to Hematite Nanocrystallines by High Energy Ball Milling

Directory of Open Access Journals (Sweden)

O. M. Lemine

2014-01-01

Full Text Available α-Fe2O3 nanocrystallines were prepared by direct transformation via high energy ball milling treatment for α-FeOOH powder. X-ray diffraction, Rietveld analysis, TEM, and vibrating sample magnetometer (VSM are used to characterize the samples obtained after several milling times. Phase identification using Rietveld analysis showed that the goethite is transformed to hematite nanocrystalline after 40 hours of milling. HRTEM confirm that the obtained phase is mostly a single-crystal structure. This result suggested that the mechanochemical reaction is an efficient way to prepare some iron oxides nanocrystallines from raw materials which are abundant in the nature. The mechanism of the formation of hematite is discussed in text.

Reactive-inspired ball-milling synthesis of an ODS steel: study of the influence of ball-milling and annealing

International Nuclear Information System (INIS)

Brocq, M.

2010-10-01

In the context of the development of new ODS (Oxide Dispersion Strengthened) steels as core materials in future nuclear reactors, we investigated a new process inspired by reactive ball-milling which consists in using YFe 3 andFe 2 O 3 as starting reactants instead of Y 2 O 3 to produce a dispersion of nano-oxides in a steel matrix and the influence of synthesis conditions on the nano-oxide characteristics were studied. For that aim, ODS steels were prepared by ball-milling and then annealed. Multi-scale characterizations were performed after each synthesis step, using notably atom probe tomography and small angle neutron scattering. The process inspired by reactive ball-milling was shown to be efficient for ODS steel synthesis, but it does not modify the nano-oxide characteristics as compared to those of oxides directly incorporated in the matrix by ball-milling. Broadly speaking, the nature of the starting oxygen bearing reactants has no influence on nano-oxide formation. Moreover, we showed that the nucleation of nano-oxides nucleation can start during milling and continues during annealing with a very fast kinetic. The final characteristics of nano-oxides formed in this way can be monitored through ball-milling parameters (intensity, temperature and atmosphere) and annealing parameters (duration and temperature). (author)

CFD Analysis of Swing of Cricket Ball and Trajectory Prediction

Science.gov (United States)

G, Jithin; Tom, Josin; Ruishikesh, Kamat; Jose, Jyothish; Kumar, Sanjay

2013-11-01

This work aims to understand the aerodynamics associated with the flight and swing of a cricket ball and predict its flight trajectory over the course of the game: at start (smooth ball) and as the game progresses (rough ball). Asymmetric airflow over the ball due to seam orientation and surface roughness can cause flight deviation (swing). The values of Drag, Lift and Side forces which are crucial for determining the trajectory of the ball were found with the help of FLUENT using the standard K- ɛ model. Analysis was done to study how the ball velocity, spin imparted to be ball and the tilt of the seam affects the movement of the ball through air. The governing force balance equations in 3 dimensions in combination a MATLAB code which used Heun's method was used for obtaining the trajectory of the ball. The conditions for the conventional swing and reverse swing to occur were deduced from the analysis and found to be in alignment with the real life situation. Critical seam angle for maximum swing and transition speed for normal to reverse swing were found out. The obtained trajectories were compared to real life hawk eye trajectories for validation. The analysis results were in good agreement with the real life situation.

Training simulator for teaching a technique to the long transmission of ball in basket-ball by a method by an arcuated hand from above with threaten

Directory of Open Access Journals (Sweden)

Charikova K.M.

2012-03-01

Full Text Available Technical devices which used in basket-ball are considered. The features of constructing of trainers and method of their application are selected in a training process. A trainer is offered for teaching a technique to the long transmission of ball in basket-ball. A trainer is a moving on a rope imitator of basket-ball ball. This construction allows to design initial position, замах for implementation of transmission and line of acceleration of ball in the final phase of motion. The method of the use of trainer is developed in an educational process.

Ball lightning as a route to fusion energy

International Nuclear Information System (INIS)

Roth, J.R.

1989-01-01

The reality of ball lightning is attested to by observations reported in surveys of large populations, which are the subject of several books. These observations indicate that its characteristics may be relevant to fusion energy applications. Ball lightning can have a diameter up to several meters, a lifetime of over 100 seconds, an energy content in excess of 10 megajoules, and an energy density and a kinetic pressure greater than that of a reacting DT plasma. This paper reviews some of the properties of ball lightning which commend it to the attention of the fusion community, and it discusses some potential advantages and applications of ball lightning fusion reactors. 11 refs., 6 figs., 1 tab

Experiments and FLUKA simulations of $^{12}C$ and $^{16}O$ beams for therapy monitoring by means of in-beam Positron Emission Tomography

CERN Document Server

Sommerer,; Ferrari, A

2007-01-01

Since 1997 at the experimental C-12 ion therapy facility at Gesellschaft fuer Schwerionenforschung (GSI), Darmstadt, Germany, more than 350 patients have been treated. The therapy is monitored with a dedicated positron emission tomograph, fully integrated into the treatment site. The measured beta+-activity arises from inelastic nuclear interactions between the beam particles an the nuclei of the patients tissue. Because the monitoring is done during the irradiation the method is called in-beam PET. The underlying principle of this monitoring is a comparison between the measured activity and a simulated one. The simulations are presently done by the PETSIM code which is dedicated to C-12 beams. In future ion therapy centers like the Heidelberger Ionenstrahl Therapiezentrum (HIT), Heidelberg, Germany, besides C-12 also proton, $^3$He and O-16 beams will be used for treatment and the therapy will be monitored by means of in-beam PET. Because PETSIM is not extendable to other ions in an easy way, a code capable ...

Monte Carlo Simulations of New 2D Ripple Filters for Particle Therapy Facilities

DEFF Research Database (Denmark)

Ringbæk, Toke Printz; Weber, Uli; Petersen, Jørgen B.B.

2014-01-01

). At the Universitätsklinikum Gießen und Marburg, Germany, a new second generation RiFi has been developed with two-dimensional groove structures. In this work we evaluate this new RiFi design. Methods: The Monte Carlo (MC) code SHIELD-HIT12A is used to determine the RiFi- induced inhomogeneities in the dose distribution...... for various ion types, initial particle energies and distances from the RiFi to the phantom surface as well as in the depth of the phantom. The beam delivery and monitor system (BAMS) used at Marburg, the Heidelberg Ionentherapiezentrum (HIT), Universit ̈tsklinikum Heidelberg, Germany and the GSI...... Helmholtzzentrum für Schwerionenforschung, Darmstadt, Germany is modeled and simulated. To evaluate the PTV dose coverage performance of the new RiFi design, the heavy ion treatment planning system TRiP98 is used for dose optimization. SHIELD-HIT12A is used to prepare the facility-specific physical dose kernels...

Effect of panel shape of soccer ball on its flight characteristics

Science.gov (United States)

Hong, Sungchan; Asai, Takeshi

2014-05-01

Soccer balls are typically constructed from 32 pentagonal and hexagonal panels. Recently, however, newer balls named Cafusa, Teamgeist 2, and Jabulani were respectively produced from 32, 14, and 8 panels with shapes and designs dramatically different from those of conventional balls. The newest type of ball, named Brazuca, was produced from six panels and will be used in the 2014 FIFA World Cup in Brazil. There have, however, been few studies on the aerodynamic properties of balls constructed from different numbers and shapes of panels. Hence, we used wind tunnel tests and a kick-robot to examine the relationship between the panel shape and orientation of modern soccer balls and their aerodynamic and flight characteristics. We observed a correlation between the wind tunnel test results and the actual ball trajectories, and also clarified how the panel characteristics affected the flight of the ball, which enabled prediction of the trajectory.

An early record of ball lightning: Oliva (Spain), 1619

Science.gov (United States)

Domínguez-Castro, Fernando

2018-05-01

In a primary documentary source we found an early record of ball lightning (BL), which was observed in the monastery of Pi (Oliva, southeastern Spain) on 18 October 1619. The ball lightning was observed by at least three people and was described as a rolling burning vessel and a ball of fire. The ball lightning appeared following a lightning flash, showed a mainly horizontal motion, crossed a wall, smudged an image of the Lady of Rebollet (then known as Lady of Pi) and burnt her ruff, and overturned a cross.

Tracking of ball and players in beach volleyball videos.

Directory of Open Access Journals (Sweden)

Gabriel Gomez

Full Text Available This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points.

Tracking of Ball and Players in Beach Volleyball Videos

Science.gov (United States)

Gomez, Gabriel; Herrera López, Patricia; Link, Daniel; Eskofier, Bjoern

2014-01-01

This paper presents methods for the determination of players' positions and contact time points by tracking the players and the ball in beach volleyball videos. Two player tracking methods are compared, a classical particle filter and a rigid grid integral histogram tracker. Due to mutual occlusion of the players and the camera perspective, results are best for the front players, with 74,6% and 82,6% of correctly tracked frames for the particle method and the integral histogram method, respectively. Results suggest an improved robustness against player confusion between different particle sets when tracking with a rigid grid approach. Faster processing and less player confusions make this method superior to the classical particle filter. Two different ball tracking methods are used that detect ball candidates from movement difference images using a background subtraction algorithm. Ball trajectories are estimated and interpolated from parabolic flight equations. The tracking accuracy of the ball is 54,2% for the trajectory growth method and 42,1% for the Hough line detection method. Tracking results of over 90% from the literature could not be confirmed. Ball contact frames were estimated from parabolic trajectory intersection, resulting in 48,9% of correctly estimated ball contact points. PMID:25426936

Supersymmetric dark-matter Q-balls and their interactions in matter

International Nuclear Information System (INIS)

Kusenko, Alexander; Loveridge, Lee C.; Shaposhnikov, Mikhail

2005-01-01

Supersymmetric extensions of the Standard Model contain nontopological solitons, Q-balls, which can be stable and can be a form of cosmological dark matter. Understanding the interaction of SUSY Q-balls with matter fermions is important for both astrophysical limits and laboratory searches for these dark-matter candidates. We show that a baryon scattering off a baryonic SUSY Q-ball can convert into its antiparticle with a high probability, while the baryon number of the Q-ball is increased by two units. For a SUSY Q-ball interacting with matter, this process dominates over those previously discussed in the literature

Micro structrual characterization and analysis of ball milled silicon carbide

Science.gov (United States)

Madhusudan, B. M.; Raju, H. P.; Ghanaraja., S.

2018-04-01

Mechanical alloying has been one of the prominent methods of powder synthesis technique in solid state involving cyclic deformation, cold welding and fracturing of powder particles. Powder particles in this method are subjected to greater mechanical deformation due to the impact of ball-powder-ball and ball-powder-container collisions that occurs during mechanical alloying. Strain hardening and fracture of particles decreases the size of the particles and creates new surfaces. The objective of this Present work is to use ball milling of SiC powder for different duration of 5, 10, 15 and 20 hours by High energy planetary ball milling machine and to evaluate the effect of ball milling on SiC powder. Micro structural Studies using Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and EDAX has been investigated.

Water Bouncing Balls: how material stiffness affects water entry

Science.gov (United States)

Truscott, Tadd

2014-03-01

It is well known that one can skip a stone across the water surface, but less well known that a ball can also be skipped on water. Even though 17th century ship gunners were aware that cannonballs could be skipped on the water surface, they did not know that using elastic spheres rather than rigid ones could greatly improve skipping performance (yet would have made for more peaceful volleys). The water bouncing ball (Waboba®) is an elastic ball used in a game of aquatic keep away in which players pass the ball by skipping it along the water surface. The ball skips easily along the surface creating a sense that breaking the world record for number of skips could easily be achieved (51 rock skips Russell Byers 2007). We investigate the physics of skipping elastic balls to elucidate the mechanisms by which they bounce off of the water. High-speed video reveals that, upon impact with the water, the balls create a cavity and deform significantly due to the extreme elasticity; the flattened spheres resemble skipping stones. With an increased wetted surface area, a large hydrodynamic lift force is generated causing the ball to launch back into the air. Unlike stone skipping, the elasticity of the ball plays an important roll in determining the success of the skip. Through experimentation, we demonstrate that the deformation timescale during impact must be longer than the collision time in order to achieve a successful skip. Further, several material deformation modes can be excited upon free surface impact. The effect of impact velocity and angle on the two governing timescales and material wave modes are also experimentally investigated. Scaling for the deformation and collision times are derived and used to establish criteria for skipping in terms of relevant physical parameters.

BALL KINEMATICS IN FINE POLISHING BETWEEN MISALIGNED DISKS IN CONIC OPENINGS

Directory of Open Access Journals (Sweden)

K. G. Shchetnikovich

2009-01-01

Full Text Available The paper considers ball kinematics in polishing between misaligned disks rotating with equal angular velocity; one of these disks has conic openings. Analytical dependences have been obtained for calculation of an angular velocity and ball sliding speed in the conic opening. It has been revealed that at a constant contact of a ball with elastic coating of a flat disk and absence of vibrations in the technological system an instantaneous axis of ball rotation does not change its position in the moving ball. It has been ascertained that when a ball is in contact with a flat disk having elastic coating with grooves changes in the position of ball rotation instantaneous axis have a regular character and do not depend on vibrations in the technological system.

Physics with colder molecular ions: The Heidelberg Cryogenic Storage Ring CSR

International Nuclear Information System (INIS)

Zajfman, D; Wolf, A; Schwalm, D; Orlov, D A; Grieser, M; Hahn, R von; Welsch, C P; Lopez-Urrutia, J R Crespo; Schroeter, C D; Urbain, X; Ullrich, J

2005-01-01

A novel cryogenic electrostatic storage ring is planned to be built at the Max-Planck Institute for Nuclear Physics in Heidelberg. The machine is expected to operate at low temperatures (∼2K) and to store beams with kinetic energies between 20 to 300 keV. An electron target based on cooled photocathode technology will serve as a major tool for the study of reactions between molecular ions and electrons. Moreover, atomic beams can be merged and crossed with the stored ion beams allowing for atom molecular-ion collision studies at very low up to high relative energies. The proposed experimental program, centered around the physics of cold molecular ions, is shortly outlined

Improvement of the Oracle setup and database design at the Heidelberg ion therapy center

International Nuclear Information System (INIS)

Hoeppner, K.; Haberer, T.; Mosthaf, J.M.; Peters, A.; Thomas, M.; Welde, A.; Froehlich, G.; Juelicher, S.; Schaa, V. R.W.; Schiebel, W.; Steinmetz, S.

2012-01-01

The HIT (Heidelberg Ion Therapy) center is an accelerator facility for cancer therapy using both carbon ions and protons, located at the university hospital in Heidelberg. It provides three therapy treatment rooms: two with fixed beam exit (both in clinical use), and a unique gantry with a rotating beam head, currently under commissioning. The backbone of the proprietary accelerator control system consists of an Oracle database running on a Windows server, storing and delivering data of beam cycles, error logging, measured values, and the device parameters and beam settings for about 100,000 combinations of energy, beam size and particle rate used in treatment plans. Since going operational, we found some performance problems with the current database setup. Thus, we started an analysis that focused on the following topics: hardware resources of the database server, configuration of the Oracle instance, and a review of the database design that underwent several changes since its original design. The analysis revealed issues on all fields. The outdated server will be replaced by a state-of-the-art machine soon. We will present improvements of the Oracle configuration, the optimization of SQL statements, and the performance tuning of database design by adding new indexes which proved directly visible in accelerator operation, while data integrity was improved by additional foreign key constraints. (authors)

Improved hydrogen sorption kinetics in wet ball milled Mg hydrides

Energy Technology Data Exchange (ETDEWEB)

Meng, Li

2011-05-04

In this work, wet ball milling method is used in order to improve hydrogen sorption behaviour due to its improved microstructure of solid hydrogen materials. Compared to traditional ball milling method, wet ball milling has benefits on improvement of MgH{sub 2} microstructure and further influences on its hydrogen sorption behavior. With the help of solvent tetrahydrofuran (THF), wet ball milled MgH{sub 2} powder has much smaller particle size and its specific surface area is 7 times as large as that of dry ball milled MgH{sub 2} powder. Although after ball milling the grain size is decreased a lot compared to as-received MgH{sub 2} powder, the grain size of wet ball milled MgH{sub 2} powder is larger than that of dry ball milled MgH{sub 2} powder due to the lubricant effect of solvent THF during wet ball milling. The improved particle size and specific surface area of wet ball milled MgH{sub 2} powder is found to be determining its hydrogen sorption kinetics especially at relatively low temperatures. And it also shows good cycling sorption behavior, which decides on its industrial applicability. With three different catalysts MgH{sub 2} powder shows improved hydrogen sorption behavior as well as the cyclic sorption behavior. Among them, the Nb{sub 2}O{sub 5} catalyst is found to be the most effective one in this work. Compared to the wet ball milled MgH{sub 2} powder, the particle size and specific surface area of the MgH{sub 2} powder with catalysts are similar to the previous ones, while the grain size of the MgH{sub 2} with catalysts is much finer. In this case, two reasons for hydrogen sorption improvement are suggested: one is the reduction of the grain size. The other may be as pointed out in some literatures that formation of new oxidation could enhance the hydrogen sorption kinetics, which is also the reason why its hydrogen capacity is decreased compared to without catalysts. After further ball milling, the specific surface area of wet ball milled Mg

BLEACHING NEPTUNE BALLS

Directory of Open Access Journals (Sweden)

BONET Maria Angeles

2014-05-01

Full Text Available Posidonia Oceanic is a seaweed from Mediterranean Sea and it is more concentrated at the Balerian SEA. This implies the Valencian Community also. It forms vaste underwater meadows in the sea and are part of the Mediterranean ecosystem. It is a sea-grass specie with fruits and flowers. Leaves are ribbon-like and they grow in winter and at the end of summer some of them are separated and arrive to some sea line. Fuit is separated and can floate, it is known as “the olive of the sea” mainly in Italy, or as the Neptune Balls. As it can be used in different fields, it is is being studied in order ro have the precitice tests. Some authors have reported the manufacturing of fully bio-based comites with a gluten matrix by hot-press molding. And it has been considered as an effective insulator for building industry or even though to determine the presence of mercure in the Mediterranean sea some years ago. As many applications can be designed from that fibers, it has been considered to be bleached in order to used them in fashionable products. Consequently, its original brown color is not the most suitable one and it should be bleached as many other cellulosic fibers. The aim of this paper is to bleache neptune balls however, the inner fibers were not accessible at all and it implied not to bleach the inner fibers in the neptune ball. Further studiesd will consider bleaching the individualized fibers.

Stability of a Fermi ball against deformation from spherical shape

International Nuclear Information System (INIS)

Yoshida, T.; Ogure, K.; Arafune, J.

2003-01-01

The stability of a Fermi ball (F ball), which is a kind of nontopological soliton accompanying the breakdown of the approximate Z 2 symmetry, is investigated in three situations: when it is electrically neutral, when it is electrically charged and unscreened, and when it is electrically charged and screened. We argue only that the third case is physically meaningful since the neutral F ball is unstable and the case of an unscreened charged F ball is observationally excluded when it has a sizable contribution to CDM. We find that the energy scale of the breakdown of the approximate Z 2 symmetry v should satisfy v 6 GeV if the F ball is the main component of CDM

Soccer Ball Lift Coefficients via Trajectory Analysis

Science.gov (United States)

Goff, John Eric; Carre, Matt J.

2010-01-01

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin…

The effect of intermediate stop and ball size in fabrication of recycled steel powder using ball milling from machining steel chips

International Nuclear Information System (INIS)

Fitri, M.W.M.; Shun, C.H.; Rizam, S.S.; Shamsul, J.B.

2007-01-01

A feasibility study for producing recycled steel powder from steel scrap by ball milling was carried out. Steel scrap from machining was used as a raw material and was milled using planetary ball milling. Three samples were prepared in order to study the effect of intermediate stop and ball size. Sample with intermediate stop during milling process showed finer particle size compared to the sample with continuous milling. Decrease in the temperature of the vial during the intermediate stop milling gives less ductile behaviour to the steel powder, which is then easily work-hardened and fragmented to fine powder. Mixed small and big size ball give the best production of recycled steel powder where it gives higher impact force to the scrap and accelerate the fragmentation of the steel scrap into powder. (author)

Effect of Ball Weight on Speed, Accuracy, and Mechanics in Cricket Fast Bowling

Directory of Open Access Journals (Sweden)

Katharine L. Wickington

2017-02-01

Full Text Available The aims of this study were: (1 to quantify the acute effects of ball weight on ball release speed, accuracy, and mechanics in cricket fast bowling; and (2 to test whether a period of sustained training with underweight and overweight balls is effective in increasing a player’s ball release speed. Ten well-trained adult male cricket players performed maximum-effort deliveries using balls ranging in weight from 46% to 137% of the standard ball weight (156 g. A radar gun, bowling target, and 2D video analysis were used to obtain measures of ball speed, accuracy, and mechanics. The participants were assigned to either an intervention group, who trained with underweight and overweight balls, or to a control group, who trained with standard-weight balls. We found that ball speed decreased at a rate of about 1.1 m/s per 100 g increase in ball weight. Accuracy and bowling mechanics were not adversely affected by changes in ball weight. There was evidence that training with underweight and overweight balls might have produced a practically meaningful increase in bowling speed (>1.5 m/s in some players without compromising accuracy or increasing their risk of injury through inducing poor bowling mechanics. In cricket fast bowling, a wide range of ball weight might be necessary to produce an effective modified-implement training program.

Digital base-band rf control system for the superconducting Darmstadt electron linear accelerator

Directory of Open Access Journals (Sweden)

M. Konrad

2012-05-01

Full Text Available The accelerating field in superconducting cavities has to be stabilized in amplitude and phase by a radio-frequency (rf control system. Because of their high loaded quality factor superconducting cavities are very susceptible for microphonics. To meet the increased requirements with respect to accuracy, availability, and diagnostics, the previous analog rf control system of the superconducting Darmstadt electron linear accelerator S-DALINAC has been replaced by a digital rf control system. The new hardware consists of two components: An rf module that converts the signal from the cavity down to the base-band and a field-programmable gate array board including a soft CPU that carries out the signal processing steps of the control algorithm. Different algorithms are used for normal-conducting and superconducting cavities. To improve the availability of the control system, techniques for automatic firmware and software deployment have been implemented. Extensive diagnostic features provide the operator with additional information. The architecture of the rf control system as well as the functionality of its components will be presented along with measurements that characterize the performance of the system, yielding, e.g., an amplitude stabilization down to (ΔA/A_{rms}=7×10^{-5} and a phase stabilization of (Δϕ_{rms}=0.8° for superconducting cavities.

Optical studies of metallo-dielectric photonic crystals

Science.gov (United States)

Kamaev, Vladimir

2007-12-01

Metallo-dielectric photonic crystals (MDPCs) are characterized by a large difference between the dielectric constants of the constituents. Owing to their high DC conductivity a broad omnidirectional band gap is formed at low frequencies. At the same time there exist numerous propagating electromagnetic modes at frequencies above a cutoff. This gives a possibility of creating a "transparent" metal: a crystal transparent in the visible spectral range and simultaneously having high DC conductivity. Since the cutoff wavelength linearly scales with the crystal periodicity, in order to make an MDPC with propagating modes in the visible range the crystal periodicity has to be around a quarter micrometer. Fabrication of such a crystal is a challenging task. One of the feasible choices is natural or artificial opals, structures made of silica balls arranged into a close packed fcc lattice. The ball diameters could vary from 200 nm to several microns, allowing the desired optical features to be in the visible spectral range. In the present work we studied metal-infiltrated opals numerically, analytically, and experimentally (Chapters 1 and 4). Both theory and experiment revealed high reflectance of the samples at large wavelengths associated with the low frequency metallic band gap formation, and low reflectance at short wavelengths that has characteristic wiggles. Contrarily, the absorbance is low in the IR region and goes up towards the UV end, which is due to low group velocity of light and high metal absorption in the region. Numerical analysis of thin metal-infiltrated opals (˜3-5 layers) did show a transmission peak around the first reflectance minimum and cutoff frequency. In Chapter 5 we present transmission experiments on thin metal films perforated with periodic arrays of holes or deposited on an opal monolayer. Both types of 2D MDPCs exhibited anomalous transmission peaks associated with surface plasma excitations. It was shown that the phenomenon could be

Visualization of air flow around soccer ball using a particle image velocimetry

Science.gov (United States)

Hong, Sungchan; Asai, Takeshi; Seo, Kazuya

2015-10-01

A traditional soccer ball is constructed using 32 pentagonal and hexagonal panels. In recent years, however, the likes of the Teamgeist and Jabulani balls, constructed from 14 and 8 panels, respectively, have entered the field, marking a significant departure from conventionality in terms of shape and design. Moreover, the recently introduced Brazuca ball features a new 6-panel design and has already been adopted by many soccer leagues. However, the shapes of the constituent panels of these balls differ substantially from those of conventional balls. Therefore, this study set out to investigate the flight and aerodynamic characteristics of different orientations of the soccer ball, which is constructed from panels of different shapes. A wind tunnel test showed substantial differences in the aerodynamic forces acting on the ball, depending on its orientation. Substantial differences were also observed in the aerodynamic forces acting on the ball in different directions, corresponding to its orientation and rotation. Moreover, two-dimensional particle image velocimetry (2D-PIV) measurements showed that the boundary separation varies depending on the orientation of the ball. Based on these results, we can conclude that the shape of the panels of a soccer ball substantially affects its flight trajectory.

Hermitian harmonic maps into convex balls

International Nuclear Information System (INIS)

Li Zhenyang; Xi Zhang

2004-07-01

In this paper, we consider Hermitian harmonic maps from Hermitian manifolds into convex balls. We prove that there exist no non-trivial Hermitian harmonic maps from closed Hermitian manifolds into convex balls, and we use the heat flow method to solve the Dirichlet problem for Hermitian harmonic maps when the domain is compact Hermitian manifold with non-empty boundary. The case where the domain manifold is complete(noncompact) is also studied. (author)

Estimation of gastric residence time of the Heidelberg capsule in humans: effect of varying food composition

International Nuclear Information System (INIS)

Mojaverian, P.; Ferguson, R.K.; Vlasses, P.H.; Rocci, M.L. Jr.; Oren, A.; Fix, J.A.; Caldwell, L.J.; Gardner, C.

1985-01-01

In animal and human studies, the gastric emptying of large (greater than 1 mm) indigestible solids is due to the activity of the interdigestive migrating myoelectric complex. The gastric residence time (GRT) of an orally administered, nondigestible, pH-sensitive, radiotelemetric device (Heidelberg capsule) was evaluated in three studies in healthy volunteers. In 6 subjects, the GRT of the Heidelberg capsule was compared with the half-emptying time (t1/2) of diethylenetriaminepentaacetic acid labeled with technetium 99m after a 4-ml/kg liquid fatty meal. The mean (+/-SD) GRT (4.3 +/- 1.4 h) was significantly (p less than 0.001) longer than the mean t1/2 (1.1 +/- 0.3 h); the GRT was prolonged compared with the t1/2 in each subject. In a randomized, crossover trial in 10 subjects, frequent feeding caused a dramatic prolongation in mean GRT of the capsule compared with the fasting state (greater than 14.5 vs. 0.5 h, p less than 0.005). In another crossover study in 6 subjects, the GRT of the capsule was evaluated after an overnight fast, a standard breakfast including solid food, and a liquid meal (i.e., 200 ml of diluted light cream). The mean GRT was 2.6 +/- 0.9 h after the liquid meal vs. 1.2 +/- 0.8 h after fasting (p less than 0.025). The mean GRT after the breakfast was 4.8 +/- 1.5 h, which was significantly greater than that after fasting (p less than 0.001) and after the liquid meal (p less than 0.01). These data suggest that the GRT of the Heidelberg capsule is a marker of the interdigestive migrating myoelectric complex in humans, the interdigestive migrating myoelectric complex can be markedly delayed by frequent feedings with solids, and the interdigestive migrating myoelectric complex is delayed by both liquid and solid meals

Estimation of gastric residence time of the Heidelberg capsule in humans: effect of varying food composition

Energy Technology Data Exchange (ETDEWEB)

Mojaverian, P.; Ferguson, R.K.; Vlasses, P.H.; Rocci, M.L. Jr.; Oren, A.; Fix, J.A.; Caldwell, L.J.; Gardner, C.

1985-08-01

In animal and human studies, the gastric emptying of large (greater than 1 mm) indigestible solids is due to the activity of the interdigestive migrating myoelectric complex. The gastric residence time (GRT) of an orally administered, nondigestible, pH-sensitive, radiotelemetric device (Heidelberg capsule) was evaluated in three studies in healthy volunteers. In 6 subjects, the GRT of the Heidelberg capsule was compared with the half-emptying time (t1/2) of diethylenetriaminepentaacetic acid labeled with technetium 99m after a 4-ml/kg liquid fatty meal. The mean (+/-SD) GRT (4.3 +/- 1.4 h) was significantly (p less than 0.001) longer than the mean t1/2 (1.1 +/- 0.3 h); the GRT was prolonged compared with the t1/2 in each subject. In a randomized, crossover trial in 10 subjects, frequent feeding caused a dramatic prolongation in mean GRT of the capsule compared with the fasting state (greater than 14.5 vs. 0.5 h, p less than 0.005). In another crossover study in 6 subjects, the GRT of the capsule was evaluated after an overnight fast, a standard breakfast including solid food, and a liquid meal (i.e., 200 ml of diluted light cream). The mean GRT was 2.6 +/- 0.9 h after the liquid meal vs. 1.2 +/- 0.8 h after fasting (p less than 0.025). The mean GRT after the breakfast was 4.8 +/- 1.5 h, which was significantly greater than that after fasting (p less than 0.001) and after the liquid meal (p less than 0.01). These data suggest that the GRT of the Heidelberg capsule is a marker of the interdigestive migrating myoelectric complex in humans, the interdigestive migrating myoelectric complex can be markedly delayed by frequent feedings with solids, and the interdigestive migrating myoelectric complex is delayed by both liquid and solid meals.

Assessment of head injury of children due to golf ball impact.

Science.gov (United States)

Lee, Heow Pueh; Wang, Fang

2010-10-01

Head trauma injury due to impact by a flying golf ball is one of the most severe possible injury accidents on the golf course. Numerical simulations based on the finite element method are presented to investigate head injury in children due to impact by a flying golf ball. The stress and energy flow patterns in a head model during the golf ball impact are computed for various combinations of striking speed, falling angle of the golf ball before impact, and impact location. It is found that a child is more prone to head injury due to golf ball impact on the frontal and side/temporal areas. The simulated results are found to conform to the clinical reports on children's head injuries from flying golf balls.

Ball check valve

International Nuclear Information System (INIS)

Bevilacqua, F.

1978-01-01

A pressurized nuclear reactor having an instrument assembly sheathed in a metallic tube which is extended vertically upward into the reactor core by traversing a metallic guide tube which is welded to the wall of the vessel is described. Sensors in each instrument assembly are connected to instruments outside the vessel to manifest the conditions within the core. Each instrument assembly probe is moved into position within a metallic guide channel. The guide channel penetrates the wall of the vessel and forms part of the barrier to the environment within the pressure vessel. Each channel includes a ball check valve which is opened by the instrument assembly probe when the probe passes through the valve. A ball valve element is moved from its seat by the probe to a position lateral of the bore of the channel and is guided to its seat along a sloped path within the valve body when the probe is removed. 5 claims, 3 figures

The development of cobalt-base alloy ball bearing

International Nuclear Information System (INIS)

Yu Xinshui; Chen Jianting; Wang Zaishu; Wang Ximei; Huang Chongming.

1986-01-01

The main technologies and experiences in developing a Cobalt-base alloy ball bearing are described. In the hardfacing of bearing races, a lower-hardness alloy of type St-6 is used rather than an alloy with hardness similar to that of the ball and finally the hardness of race is increased to match that of the ball by heat treatment. This improvement has certain advantages. The experience of whole developing technology indicates that strict control of the technology in the bearing-race hardfacing is the key problem in the quality assurance of bearings

Launch Creativity with Ping-Pong Ball Challenge

Science.gov (United States)

Kornoelje, Joanne; Roman, Harry T.

2011-01-01

Educators at Thomas A. Edison Middle School have worked together to bring invention information and activities to life. One activity in particular, Ping-Pong Ball Invention Challenge, has proven a great success. The Ping-Pong Ball Invention Challenge was inspired by the basic rules for PBS's "Design Squad"'s "Pop Fly" activity. In this article,…

Nonlinear dynamic model for skidding behavior of angular contact ball bearings

Science.gov (United States)

Han, Qinkai; Chu, Fulei

2015-10-01

A three-dimensional nonlinear dynamic model is proposed to predict the skidding behavior of angular contact ball bearings under combined load condition. The centrifugal and gyroscopic effects induced by ball rotation and revolution, Hertz contact between the ball and inner/outer races, discontinuous contact between the ball and cage and elastohydrodynamic lubrication are considered in the model. Through comparisons with the tested results of the reference, the dynamic model is verified. Based upon these, variations of ball slipping speed with time and space are discussed for the bearing under combined load condition. It is shown that radial load leads to the fluctuations in the slipping velocity of the ball contacting with inner/outer races, especially for the ball in load-decreasing regions. Adding the radial load would significantly increase the amplitude and range of slipping velocity, indicating that the skidding becomes more serious. As the ball still withstands contact load in the load-decreasing region, large slipping velocity would increase the temperature of both bearing and lubricant oil, intensify the wear and then might shorten the bearing service life. Therefore, the radial load should be considered carefully in the design and monitoring of rotating machinery.

Anchoring interprofessional education in undergraduate curricula: The Heidelberg story.

Science.gov (United States)

Berger, Sarah; Goetz, Katja; Leowardi-Bauer, Christina; Schultz, Jobst-Hendrik; Szecsenyi, Joachim; Mahler, Cornelia

2017-03-01

The ability of health professionals to collaborate effectively has significant potential impact on patient safety and quality-care outcomes, especially given the increasingly complex and dynamic clinical practice environments of today. Educators of the health professions are faced with an immediate challenge to adapt curricula and traditional teaching methods to ensure graduates are equipped with the necessary interprofessional competencies and (inter)professional values for their future practice. The World Health Organization's "Framework for action in interprofessional education (IPE) and collaborative practice" promotes IPE as a key strategy to enhance patient outcomes by preparing a "collaborative practice-ready health workforce." Logistical and attitudinal barriers can hinder integration of IPE into curricula. Lessons learned through the implementation of a planned change to establish four interprofessional seminars (team communication, medical error communication, healthcare English, and small business management) at Heidelberg University Medical Faculty, Germany, are described. A key factor in successfully anchoring IPE seminars in the undergraduate curricula was the structured approach drawing on change management concepts.

Crystal Ball: On the Future High Energy Colliders

Energy Technology Data Exchange (ETDEWEB)

Shiltsev, Vladimir [Fermilab

2015-09-20

High energy particle colliders have been in the forefront of particle physics for more than three decades. At present the near term US, European and international strategies of the particle physics community are centered on full exploitation of the physics potential of the Large Hadron Collider (LHC) through its high-luminosity upgrade (HL-LHC). A number of next generation collider facilities have been proposed and are currently under consideration for the medium- and far-future of the accelerator-based high energy physics. In this paper we offer a uniform approach to evaluation of various accelerators based on the feasibility of their energy reach, performance reach and cost range. We briefly review such post-LHC options as linear e+e- colliders in Japan (ILC) or at CERN (CLIC), muon collider, and circular lepton or hadron colliders in China (CepC/SppC) and Europe (FCC). We conclude with a look into ultimate energy reach accelerators based on plasmas and crystals, and some perspectives for the far future of accelerator-based particle physics.

Random power series in the unit ball of Cn

International Nuclear Information System (INIS)

Shi Jihuai.

1989-07-01

The random power series in the unit disc has been studied by many authors. In this paper, we studied the random power series in the unit ball of C n and generalized some results in the unit disc to the unit ball, in particular, the result obtained recently by Duren has been generalized to the unit ball. The main tool used here is the generalized Salem-Zygmund's theorem. (author). 12 refs

Thermoelastoplastic Deformation of a Multilayer Ball

Science.gov (United States)

Murashkin, E. V.; Dats, E. P.

2017-09-01

The problem of centrally symmetric deformation of a multilayer elastoplastic ball in the process of successive accretion of preheated layers to its outer surface is considered in the framework of small elastoplastic deformations. The problems of residual stress formation in the elastoplastic ball with an inclusion and a cavity are solved under various mechanical boundary conditions on the inner surface and for prescribed thermal compression distributions. The graphs of residual stress and displacement fields are constructed.

The Heidelberg POLYP - a flexible and fault-tolerant poly-processor

International Nuclear Information System (INIS)

Maenner, R.; Deluigi, B.

1981-01-01

The Heidelberg poly-processor system POLYP is described. It is intended to be used in nuclear physics for reprocessing of experimental data, in high energy physics as second-stage trigger processor, and generally in other applications requiring high-computing power. The POLYP system consists of any number of I/O-processors, processor modules (eventually of different types), global memory segments, and a host processor. All modules (up to several hundred) are connected by a multiple common-data-bus system; all processors, additionally, by a multiple sync bus system for processor/task-scheduling. All hard- and software is designed to be decentralized and free of bottle-necks. Most hardware-faults like single-bit errors in memory or multi-bit errors during transfers are automatically corrected. Defective modules, buses, etc., can be removed with only a graceful degradation of the system-throughput. (orig.)

On the isoperimetric rigidity of extrinsic minimal balls

DEFF Research Database (Denmark)

Markvorsen, Steen; Palmer, V.

2003-01-01

We consider an m-dimensional minimal submanifold P and a metric R-sphere in the Euclidean space R-n. If the sphere has its center p on P, then it will cut out a well defined connected component of P which contains this center point. We call this connected component an extrinsic minimal R-ball of P....... The quotient of the volume of the extrinsic ball and the volume of its boundary is not larger than the corresponding quotient obtained in the space form standard situation, where the minimal submanifold is the totally geodesic linear subspace R-m. Here we show that if the minimal submanifold has dimension...... larger than 3, if P is not too curved along the boundary of an extrinsic minimal R-ball, and if the inequality alluded to above is an equality for the extrinsic minimal ball, then the minimal submanifold is totally geodesic....

A self-similar magnetohydrodynamic model for ball lightnings

International Nuclear Information System (INIS)

Tsui, K. H.

2006-01-01

Ball lightning is modeled by magnetohydrodynamic (MHD) equations in two-dimensional spherical geometry with azimuthal symmetry. Dynamic evolutions in the radial direction are described by the self-similar evolution function y(t). The plasma pressure, mass density, and magnetic fields are solved in terms of the radial label η. This model gives spherical MHD plasmoids with axisymmetric force-free magnetic field, and spherically symmetric plasma pressure and mass density, which self-consistently determine the polytropic index γ. The spatially oscillating nature of the radial and meridional field structures indicate embedded regions of closed field lines. These regions are named secondary plasmoids, whereas the overall self-similar spherical structure is named the primary plasmoid. According to this model, the time evolution function allows the primary plasmoid expand outward in two modes. The corresponding ejection of the embedded secondary plasmoids results in ball lightning offering an answer as how they come into being. The first is an accelerated expanding mode. This mode appears to fit plasmoids ejected from thundercloud tops with acceleration to ionosphere seen in high altitude atmospheric observations of sprites and blue jets. It also appears to account for midair high-speed ball lightning overtaking airplanes, and ground level high-speed energetic ball lightning. The second is a decelerated expanding mode, and it appears to be compatible to slowly moving ball lightning seen near ground level. The inverse of this second mode corresponds to an accelerated inward collapse, which could bring ball lightning to an end sometimes with a cracking sound

Structural and dynamical properties of Yukawa balls

International Nuclear Information System (INIS)

Block, D; Kroll, M; Arp, O; Piel, A; Kaeding, S; Ivanov, Y; Melzer, A; Henning, C; Baumgartner, H; Ludwig, P; Bonitz, M

2007-01-01

To study the structural and dynamical properties of finite 3D dust clouds (Yukawa balls) new diagnostic tools have been developed. This contribution describes the progress towards 3D diagnostics for measuring the particle positions. It is shown that these diagnostics are capable of investigating the structural and dynamical properties of Yukawa balls and gaining insight into their basic construction principles

Validity and Reliability of a Medicine Ball Explosive Power Test.

Science.gov (United States)

Stockbrugger, Barry A.; Haennel, Robert G.

2001-01-01

Evaluated the validity and reliability of a medicine ball throw test to evaluate explosive power. Data on competitive sand volleyball players who performed a medicine ball throw and a standard countermovement jump indicated that the medicine ball throw test was a valid and reliable way to assess explosive power for an analogous total-body movement…

Gas-discharge particle detector with ball-tipped anodes

International Nuclear Information System (INIS)

Travkin, V.I.; Khazins, D.M.

1987-01-01

A new gas-discharge particle detector, whose anode is a set of balls 2mm in diameter is investigated. The chamber is blowing down by the argon-methane-methylal gas mixture with the ratio 3:1:1. The detector operates in the self-quenching streamer mode, has high efficiency and a wide counting characteristic plateau. The maximum counting rate of particles at one ball is ∼ 2.5x10 4 s -1 . The ball-tipped anodes allow making reliable complex-shaped detectors. Two-coordinate detection of multiparticle events can be naturally organized in detectors like that

Real-time detecting and tracking ball with OpenCV and Kinect

Science.gov (United States)

Osiecki, Tomasz; Jankowski, Stanislaw

2016-09-01

This paper presents a way to detect and track ball with using the OpenCV and Kinect. Object and people recognition, tracking are more and more popular topics nowadays. Described solution makes it possible to detect ball based on the range, which is set by the user and capture information about ball position in three dimensions. It can be store in the computer and use for example to display trajectory of the ball.

Estructura temporal y gestual del kin-ball

Directory of Open Access Journals (Sweden)

Rafael Díaz Amate

2015-06-01

Full Text Available El objetivo de este estudio es analizar la estructura temporal del kin-ball y cuantificar el número de golpeos, jugadas, puntos y los tipos de contacto utilizados, en cada período y partido. Se han analizado un total de 13 partidos, correspondientes a la fase de grupos, semifinales y final del VII Campeonato de España de Kin-ball. Es un deporte caracterizado por la realización de esfuerzos interválicos de intensidad media-alta y de corta duración. Un partido de kin-ball tiene una duración media de 46 min aproximadamente, siendo el ratio tiempo de trabajo y tiempo de descanso de 1:1,51 y la duración media por punto de 12,07 s. Así, un partido de kin-ball tiene un volumen de 73 puntos con un total de 390 golpeos. Los tipos de golpeos utilizados determinan que es un deporte defensivo. Todos estos análisis ayudan a tener un mayor conocimiento de esta disciplina deportiva por parte de los entrenadores y jugadores para tener un entrenamiento más específico.

Carbon fiber structure for B.G.O. crystals of an electromagnetic calorimeter for energies around and above 2 GeV

International Nuclear Information System (INIS)

Anamateros, E.; Germenia, C.; Napoleone, T.

1991-01-01

This document describes a project to construct with composite material an Electromagnetic Calorimeter for a large, solid angle crystal ball for energies around and above 2 GeV, with thin walls (0.36 mm) and a complex figure like a 'Rugby Ball'. The contract was between the National Institute of Nuclear Physics (INFN) of Frascati, Genova, Catania, and Roma, and ITALCOMPOSITI - a joint venture between Agusta Group (50%) and ENI (50%) to research, produce and market advanced prepreg materials and composite structural components for aerospace, defense, energy, and transport applications. The contract concerns the design and the realization of the structure, which consists of 24 baskets containing 480 crystals of B.G.O. weighing about 4 Kg, each with full alveolus, including electronic systems

Formation and stabilization of multiple ball-like flames at Earth gravity

KAUST Repository

Zhou, Zhen

2018-03-20

Near-limit low-Lewis-number premixed flame behavior is studied experimentally and numerically for flames of H–CH–air mixtures that are located in a 55 mm diameter tube and below a perforated plate in a downward mixture flow. A combustion regime diagram is experimentally identified in terms of equivalence ratio and ratio of H to CH (variation of fuel Lewis number). Planar flames, cell-like flames, distorted cap-like flames, and arrays of ball-like flames are progressively observed in the experiments as the equivalence ratio is decreased. The experimentally observed ball-like lean limit flames experience chaotic motion, which is accompanied by sporadic events of flame splitting and extinction, while the total number of simultaneously burning flamelets remains approximately the same. In separate experiments, the multiple ball-like lean limit flames are stabilized by creating a slightly non-uniform mixture flow field. The CH* chemiluminescence distributions of the lean limit flames are recorded, showing that the ball-like lean limit flame front becomes more uniform in intensity and its shape approaches a spherical one with the increase of H content in the fuel. Numerical simulations are performed for single representative flames of the array of stabilized flamelets observed in the experiments. The simulated ball-like lean limit flame is further contrasted with the single ball-like flame that forms in a narrow tube (13.5 mm inner diameter) with an iso-thermal wall. The numerical results show that the ball-like lean limit flames present in the array of ball-like flames are more affected by the buoyancy-induced recirculation zone, compared with that in the narrow tube, revealing why the shape of the ball-like flame in the array deviates more from a spherical one. All in all, the wall confinement is not crucial for the formation of ball-like flames at terrestrial gravity.

Anti-collapse mechanism of CBM fuzzy-ball drilling fluid

Directory of Open Access Journals (Sweden)

Lihui Zheng

2016-03-01

Full Text Available Although fuzzy-ball drilling fluid has been successfully applied in CBM well drilling, it is necessary to study its anti-collapse mechanism so that adjustable coalbed sealing effects, controllable sealing strength, rational sealing cost and controllable reservoir damage degree can be realized. In this paper, laboratory measurement was performed on the uniaxial compressive strength of the plungers of No. 3 coalbed in the Qinshui Basin and the inlet pressure of Ø38 mm coal plunger displacement. The strengths of coal plungers were tested and compared after 2% potassium chloride solution, low-solids polymer drilling fluid and fuzzy-ball drilling fluid were injected into the coal plungers respectively. It is shown that coal strength rises by 38.46% after the fuzzy-ball drilling fluid is injected (in three groups; and that no fuzzy-ball drilling fluid is lost at the displacement pressures of 20.73 and 21.46 MPa, nor 2% potassium chloride solution is leaked at such pressures of 24.79 and 25.64 MPa after the plunger was sealed by the fuzzy-ball drilling fluid. This indicates that the fuzzy-ball drilling fluid can increase the formation resistance to fluid. Indoor microscopic observation was conducted on the sealing process of the fuzzy-ball drilling fluid in sand packs with coal cuttings of three grain sizes (60–80, 80–100 and 100–120 mesh. It is shown that the leakage pathways of different sizes are sealed by the vesicles in the form of accumulation, stretch and blockage. And there are vesicles at the inlet ends of the flowing pathways in the shape of beaded blanket. The impact force of drilling tools on the sidewalls is absorbed by the vesicles due to their elasticity and tenacity, so the sidewall instability caused by drilling tools is relieved. It is concluded that the main anti-collapse mechanisms of the CBM fuzzy-ball drilling fluid are to raise the coal strength, increase the formation resistance to fluid, and buffer the impact of

Long-Term Effects on Graphene Supercapacitors of Using a Zirconia Bowl and Zirconia Balls for Ball-Mill mixing of Active Materials

Science.gov (United States)

Song, Dae-Hoon; Kim, Jin-Young; Kahng, Yung Ho; Cho, Hoonsung; Kim, Eung-Sam

2018-04-01

Improving the energy storage performance of supercapacitor electrodes based on reduced graphene oxide (RGO) is one of the main subjects in this research field. However, when a zirconia bowl and zirconia balls were used for ball-mill mixing of the active materials for RGO supercapacitors, the energy storage performance deteriorated over time. Our study revealed that the source of the problem was the inclusion of zirconia bits from abrasion of the bowl and the balls during the ballmill mixing, which increased during a period of 1 year. We probed two solutions to this problem: 1) hydrofluoric (HF) acid treatment of the RGO supercapacitors and 2) use of a tempered steel bowl and tempered steel balls for the mixing. For both cases, the energy storage performance was restored to near the initial level, showing a specific capacitance ( C sp ) of 200 F/g. Our results should lead to progress in research on RGO supercapacitors.

Physical and Tribological Properties of Nitrided AISI 316 Stainless Steel Balls

Directory of Open Access Journals (Sweden)

Yang Shicai

2016-01-01

Full Text Available AISI 316 austenitic stainless steel balls (diameters 5.0 and 12.0 mm, typical hardness 250 HV0.3 and flat samples (20×20×2.0 mm were nitrided by a pulsed glow discharge Ar/N2 plasma. Hardness of the ball surfaces was analysed using Vickers indentation. Thermal stability of the nitrided balls (diameter 12.0 mm was studied using a furnace to heat them in air for 8 hours at temperatures up to 700.0°C and then, after cooling to room temperature, the surface hardness of the heated balls was re-measured. Scanning electron microscopy and X-ray diffraction were used to study the microstructures, composition and phase formation of the nitrided sublayers. Unlubricated pin-on-disc wear testing was used to evaluate the wear resistance of nitrided stainless steel balls (5.0 mm diameter and the results were compared with similar testing on hardened Cr-Steel balls (5 mm diameter with hardness of about 650 HV0.3. All the test results indicated that the nitrided AISI 316 austenitic stainless steel balls have advantages over the hardened Cr-Steel balls in terms of retaining high hardness after heat treatment and high resistance to sliding wear at room temperature under higher counterpart stress. These properties are expected to be beneficial for wide range of bearing applications.

Construction of a test stand for the measurement of the light output uniformity of CALIFA crystals

Energy Technology Data Exchange (ETDEWEB)

Susenburger, Markus; Ignatov, Alexander; Kroell, Thorsten [Technische Universitaet Darmstadt, Darmstadt (Germany)

2016-07-01

Currently, the Facility for Antiproton and Ion Research (FAIR) at GSI in Darmstadt is under construction. One experiment at GSI and FAIR is called Reactions with Relativistic Radioactive Beams (R{sup 3}B). A key component of the R{sup 3}B is the CALorimeter for In Flight detection of γ-rays and light charged pArticles (CALIFA), which will surround the R{sup 3}B target chamber and will be capable of the detection of γ-rays in a wide energy range from 100 keV to 30 MeV as well as of light charged particles. CALIFA is built out of two parts, the so called CALIFA barrel and CALIFA endcap. The barrel consists of 1952 CsI(Tl) detector crystals which have to fulfill several specifications. One of these specifications is the uniformity of the light output. Depending on the location of the deposited energy, the crystal's light output varies due to optical focusing effects. This behavior can be manipulated by lapping the crystal's surface. The aim of this work is the development of a test stand which will check if the crystals match the requirements according to the light output uniformity. Because of the large number of crystals needed to be tested, the stand automates the test procedure, which guarantees comparable test measurement for all crystals. The development and construction of this stand is reported.

Wear numbers for ball cup and journal bearings

NARCIS (Netherlands)

Ligterink, D.J.; Moes, H.

1980-01-01

A wear number is defined for ball cup bearings and for journal bearings where the cup and the cylindrical bearing are made of soft material. This dimensionless wear number provides a relation between the following five quantities: the radius of the ball or the length of the journal bearing in

Two balls and a string: from ordered motion to chaos

International Nuclear Information System (INIS)

Sacks, William; Mauger, Alain

2013-01-01

Two spherical balls are connected by a taught string passing through a small hole in a perfectly planar table: the first ball, subject to a central force, moves without friction on a two-dimensional plane, while the second ball moves only along the vertical axis directly below the hole. The pedagogical aspects of this novel two-body problem are given particular attention: Newton’s laws, central force motion, conservation laws, angular momentum, constraints, etc. The dynamics of the system is considered under various initial conditions wherein the ball on the table moves qualitatively in rotating ellipses or hypotrochoids. The conditions for closed or periodic orbits are examined. The more complex case of the inclined plane is then considered, revealing a rich variety of periodic, aperiodic and chaotic solutions as a function of the ball mass ratio and the plane inclination angle. The associated Poincaré phase-space maps are discussed. (paper)

Behavior of hollow balls containing granules bouncing repeatedly off the ground

Science.gov (United States)

Hu, Min; Mu, Qing-song; Luo, Ning; Li, Gang; Peng, Ning-bo

2013-07-01

An experimental study of the behavior of hollow balls filled with some granules (mung beans or millets) bouncing repeatedly off a static flat horizontal surface is presented. We observed that the bounce number of the ball is limited and decreases regularly with an increasing number of granules. Moreover, for two balls containing a different kind of granules, their bounce numbers are basically equal when the two balls have the same mass of granules. While there is no clear relationship between the first rebound height of one ball and the number of granules, there appears an exponential decay of the second rebound height with an increase of the granule number. Furthermore, a two-dimensional numerical model has been created to find out the law of the ball's rebound height and the dissipation law of the granule nested system. A generalized prediction equation to reasonably explain the law of the bounce number has also been proposed.

Dry grinding of talc in a stirred ball mill

Directory of Open Access Journals (Sweden)

Cayirli Serkan

2016-01-01

Full Text Available The aim of this work was to investigate micro fine size dry grindability of talc in a stirred ball mill. The effects of various parameters such as grinding time, stirrer speed, powder filling ratio and ball filling ratio were investigated. Alumina balls were used as grinding media. Experiments were carried out using the 24 full factorial design. The main and interaction effects were evaluated using the Yates method. Test results were evaluated on the basis of product size and surface area.

Determination of the boundary conditions of the grinding load in ball mills

Science.gov (United States)

Sharapov, Rashid R.

2018-02-01

The prospects of application in ball mills for grinding cement clinker with inclined partitions are shown. It is noted that ball mills with inclined partitions are more effective. An algorithm is proposed for calculating the power consumed by a ball mill with inclined inter-chamber partitions in which an axial movement of the ball load takes place. The boundary conditions in which the ball load is located are determined. The equations of bounding the grinding load are determined. The behavior of a grinding load is considered in view of the characteristic cross sections. The coordinates of the centers of gravity of the grinding load with a definite step and the shape of the cross sections are determined. It is theoretically shown that grinding load in some parts of the ball mill not only consumes, but also helps to rotate the ball mill. Methods for calculating complex analytical expressions for determining the coordinates of the centers of gravity of the grinding load under the conditions of its longitudinal motion have developed. The carried out researches allow to approach from the general positions to research of behavior of a grinding load in the ball mills equipped with various in-mill devices.

Historiografia del “Ball de Torrent”: De la moixiganga barroca al quadre de balls populars valencians (1692-1929

Directory of Open Access Journals (Sweden)

Raül Sanchis Francés

2013-06-01

Full Text Available Resum: El Ball de Torrent és una moixiganga dramàtica popular escenificada a la ciutat de València i altres indrets del País Valencià des de finals del segle XVII fins a principis del segle XX. Estava organitzada per agrupacions gremials, juntes d’hospitals o clavaris de festes i protagonitzada per personatges agrupats en comparses que representaven una paròdia sobre les relacions entre les estructures de poder i les classes populars. Tot i la variabilitat segons el moment històric, es conforma com una mescla de quadres amb danses, música i jocs teatrals. El ball interacciona de diverses formes amb algunes festes valencianes i és, probablement, una de les mostres de teatre de carrer més nostrades i menys estudiades de la València Moderna. En aquest article es realitza una revisió bibliogràfica crítica i una primera anàlisi historiogràfica.Paraules clau: Ball de Torrent, Dansa i música tradicional, Teatre, Moixiganga, Festa valencianaAbstract: Ball de Torrent (Dance of Torrent is a popular dramatic masquerade staged in Valencia since the late seventeenth century to the early twentieth. It was organized by guilds, hospital managements or festival organizers. The actors were grouped in associations representing a parody on the relationships between power structures and popular classes. Despite the variability depending on the historical period, it consisted of a mixture of episodes or scenes with dance, music and theatre games. Any Festivals in Valencia are connected with the Ball de Torrent. It’s probably one of the most interesting samples of street theatre and studied under of the Modern Valencia. This paper analyses historical sources to review and critique bibliography.Keywords: Dance of Torrent, Traditional Dance and Music, Theatre, Masquerade, Feasts of Valencia

Thermal Analysis of Ball screw Systems by Explicit Finite Difference Method

Energy Technology Data Exchange (ETDEWEB)

Min, Bog Ki [Hanyang Univ., Seoul (Korea, Republic of); Park, Chun Hong; Chung, Sung Chong [KIMM, Daejeon (Korea, Republic of)

2016-01-15

Friction generated from balls and grooves incurs temperature rise in the ball screw system. Thermal deformation due to the heat degrades positioning accuracy of the feed drive system. To compensate for the thermal error, accurate prediction of the temperature distribution is required first. In this paper, to predict the temperature distribution according to the rotational speed, solid and hollow cylinders are applied for analysis of the ball screw shaft and nut, respectively. Boundary conditions such as the convective heat transfer coefficient, friction torque, and thermal contact conductance (TCC) between balls and grooves are formulated according to operating and fabrication conditions of the ball screw. Explicit FDM (finite difference method) is studied for development of a temperature prediction simulator. Its effectiveness is verified through numerical analysis.

The goalkeeper influence on ball possession effectiveness in futsal

Directory of Open Access Journals (Sweden)

Vicente-Vila Pedro

2016-06-01

Full Text Available The aim of this study was to identify which variables were the best predictors of success in futsal ball possession when controlling for space and task related indicators, situational variables and the participation of the goalkeeper as a regular field player or not (5 vs. 4 or 4 vs. 4. The sample consisted of 326 situations of ball possession corresponding to 31 matches played by a team from the Spanish Futsal League during the 2010–2011, 2011–2012 and 2012–2013 seasons. Multidimensional qualitative data obtained from 10 ordered categorical variables were used. Data were analysed using chi-square analysis and multiple logistic regression analysis. Overall, the highest ball possession effectiveness was achieved when the goalkeeper participated as a regular field player (p<0.01, the duration of the ball possession was less than 10 s (p<0.01, the ball possession ended in the penalty area (p<0.01 and the defensive pressure was low (p<0.01. The information obtained on the relative effectiveness of offensive playing tactics can be used to improve team’s goal-scoring and goal preventing abilities.

An investigation of the generation and properties of laboratory-produced ball lightning

Science.gov (United States)

Oreshko, A. G.

2015-06-01

The experiments revealed that ball lightning is a self-confining quasi-neutral in a whole plasma system that rotates around its axis. Ball lightning has a structure of a spherical electric domain, consisting of a kernel with excess negative charge and an external spherical layer with excess positive charge. The excess of charges of one sort and the lack of charges of the other sort in the kernel or in the external spherical layer significantly reduces the possibility of electron capture by means of an electric field, created by the nearest ions and leads to a drastic slowdown of recombination process. Direct proof has been obtained that inside of ball lightning - in an external spherical layer that rotates around the axis - there is a circular current of sub-relativistic particles. This current creates and maintains its own poloidal magnetic field of ball lightning, i.e. it carries out the function of magnetic dynamo. The kernel of ball lightning is situated in a region with minimum values of induction of the magnetic field. The inequality of positive and negative charges in elements of ball lightning also significantly reduces losses of the charged plasma on bremsstrahlung. Ball lightning generation occurs in a plasmic vortex. The ball lightning energy in the region of its generation significantly differs from the ball lightning energy, which is drifting in space. The axial component of kinetic energy of particles slightly exceeds 100 keV and the rotational component of the ions energy is a bit greater than 1 MeV. Ball lightning is `embedded' in atmosphere autonomous accelerator of charged particles of a cyclotron type due to self-generation of strong crossed electric and magnetic fields. A discussion of the conditions of stability and long-term existence of ball lightning is given.

An aerodynamic analysis of recent FIFA world cup balls

Science.gov (United States)

Kiratidis, Adrian L.; Leinweber, Derek B.

2018-05-01

Drag and lift coefficients of recent FIFA world cup balls are examined. We fit a novel functional form to drag coefficient curves and in the absence of empirical data provide estimates of lift coefficient behaviour via a consideration of the physics of the boundary layer. Differences in both these coefficients for recent balls, which result from surface texture modification, can significantly alter trajectories. Numerical simulations are used to quantify the effect these changes have on the flight paths of various balls. Altitude and temperature variations at recent world cup events are also discussed. We conclude by quantifying the influence these variations have on the three most recent world cup balls, the Brazuca, the Jabulani and the Teamgeist. While our paper presents findings of interest to the professional sports scientist, it remains accessible to students at the undergraduate level.

Electrostatic charge bounds for ball lightning models

International Nuclear Information System (INIS)

Stephan, Karl D

2008-01-01

Several current theories concerning the nature of ball lightning predict a substantial electrostatic charge in order to account for its observed motion and shape (Turner 1998 Phys. Rep. 293 1; Abrahamson and Dinniss 2000 Nature 403 519). Using charged soap bubbles as a physical model for ball lightning, we show that the magnitude of charge predicted by some of these theories is too high to allow for the types of motion commonly observed in natural ball lightning, which includes horizontal motion above the ground and movement near grounded conductors. Experiments show that at charge levels of only 10-15 nC, 3-cm-diameter soap bubbles tend to be attracted by induced charges to the nearest grounded conductor and rupture. We conclude with a scaling rule that can be used to extrapolate these results to larger objects and surroundings

Numerical study of Q-ball formation in gravity mediation

International Nuclear Information System (INIS)

Hiramatsu, Takashi; Kawasaki, Masahiro; Takahashi, Fuminobu

2010-01-01

We study Q-ball formation in the expanding universe on 1D, 2D and 3D lattice simulations. We obtain detailed Q-ball charge distributions, and find that the distribution is peaked at Q 3D peak ≅ 1.9 × 10 −2 (|Φ in |/m) 2 , which is greater than the existing result by about 60%. Based on the numerical simulations, we discuss how the Q-ball formation proceeds. Also we make a comment on possible deviation of the charge distributions from what was conjectured in the past

Measurements of the Motion of Plasma Filaments in a Plasma Ball

International Nuclear Information System (INIS)

Campanell, M.; Laird, J.; Provost, T.; Vasquez, S.; Zweben, S.J.

2010-01-01

Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ∼106 cm/sec at the driving frequency of ∼26 kHz, and drift upward through the ball at ∼1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.

Measurements of the Motion of Plasma Filaments in a Plasma Ball

Energy Technology Data Exchange (ETDEWEB)

Campanell, M.; Laird, J.; Provost, T.; Vasquez, S.; Zweben, S. J.

2010-01-26

Measurements were made of the motion of the filamentary structures in a plasma ball using high speed cameras and other optical detectors. These filaments traverse the ball radially at ~106 cm/sec at the driving frequency of ~26 kHz, and drift upward through the ball at ~1 cm/sec. Varying the applied high voltage and frequency caused the number, length, and diameter of the filaments to change. A custom plasma ball was constructed to observe the effects of varying gas pressure and species on the filament structures.

Supermassive dark-matter Q-balls in galactic centers?

Energy Technology Data Exchange (ETDEWEB)

Troitsky, Sergey [Institute for Nuclear Research of the Russian Academy of Sciences,60th October Anniversary Prospect 7a, Moscow 117312 (Russian Federation); Moscow Institute for Physics and Technology,Institutskii per. 9, 141700, Dolgoprudny, Moscow Region (Russian Federation)

2016-11-11

Though widely accepted, it is not proven that supermassive compact objects (SMCOs) residing in galactic centers are black holes. In particular, the Milky Way’s SMCO can be a giant nontopological soliton, Q-ball, made of a scalar field: this fits perfectly all observational data. Similar but tiny Q-balls produced in the early Universe may constitute, partly or fully, the dark matter. This picture explains in a natural way, why our SMCO has very low accretion rate and why the observed angular size of the corresponding radio source is much smaller than expected. Interactions between dark-matter Q-balls may explain how SMCOs were seeded in galaxies and resolve well-known problems of standard (non-interacting) dark matter.

Structure Design and Performance Analysis of High-Speed Miniature Ball Bearing

Science.gov (United States)

Li, Songsheng; Zhang, Guoye; Chen, Bin; Shen, Yuan

2017-07-01

The working performances of miniature ball bearings are obviously affected by its’ geometric structure parameters. In this paper, quasi-static analysis theory is applied in the design of miniature ball bearings. Firstly, it is studied the influence of geometry structure, preload and rotating speed on the dynamic performance of bearing. Secondly, bearing dynamic characteristics are analyzed which include the bearing stiffness and Spin to roll Ratio. Lastly, the contact stress and bearing life are calculated. The results indicate that structure parameters play an importance role in bearing’s dynamic performances. Miniature ball bearings which have lager ball number, bigger ball diameter and smaller inner race groove radius can get better performances while velocity and preload have great impact on the bearing life. So that parameters of miniature bearing should be chosen cautiously.

Neural extrapolation of motion for a ball rolling down an inclined plane.

Science.gov (United States)

La Scaleia, Barbara; Lacquaniti, Francesco; Zago, Myrka

2014-01-01

It is known that humans tend to misjudge the kinematics of a target rolling down an inclined plane. Because visuomotor responses are often more accurate and less prone to perceptual illusions than cognitive judgments, we asked the question of how rolling motion is extrapolated for manual interception or drawing tasks. In three experiments a ball rolled down an incline with kinematics that differed as a function of the starting position (4 different positions) and slope (30°, 45° or 60°). In Experiment 1, participants had to punch the ball as it fell off the incline. In Experiment 2, the ball rolled down the incline but was stopped at the end; participants were asked to imagine that the ball kept moving and to punch it. In Experiment 3, the ball rolled down the incline and was stopped at the end; participants were asked to draw with the hand in air the trajectory that would be described by the ball if it kept moving. We found that performance was most accurate when motion of the ball was visible until interception and haptic feedback of hand-ball contact was available (Experiment 1). However, even when participants punched an imaginary moving ball (Experiment 2) or drew in air the imaginary trajectory (Experiment 3), they were able to extrapolate to some extent global aspects of the target motion, including its path, speed and arrival time. We argue that the path and kinematics of a ball rolling down an incline can be extrapolated surprisingly well by the brain using both visual information and internal models of target motion.

Neural extrapolation of motion for a ball rolling down an inclined plane.

Directory of Open Access Journals (Sweden)

Barbara La Scaleia

Full Text Available It is known that humans tend to misjudge the kinematics of a target rolling down an inclined plane. Because visuomotor responses are often more accurate and less prone to perceptual illusions than cognitive judgments, we asked the question of how rolling motion is extrapolated for manual interception or drawing tasks. In three experiments a ball rolled down an incline with kinematics that differed as a function of the starting position (4 different positions and slope (30°, 45° or 60°. In Experiment 1, participants had to punch the ball as it fell off the incline. In Experiment 2, the ball rolled down the incline but was stopped at the end; participants were asked to imagine that the ball kept moving and to punch it. In Experiment 3, the ball rolled down the incline and was stopped at the end; participants were asked to draw with the hand in air the trajectory that would be described by the ball if it kept moving. We found that performance was most accurate when motion of the ball was visible until interception and haptic feedback of hand-ball contact was available (Experiment 1. However, even when participants punched an imaginary moving ball (Experiment 2 or drew in air the imaginary trajectory (Experiment 3, they were able to extrapolate to some extent global aspects of the target motion, including its path, speed and arrival time. We argue that the path and kinematics of a ball rolling down an incline can be extrapolated surprisingly well by the brain using both visual information and internal models of target motion.

Ball lightning dynamics and stability at moderate ion densities

International Nuclear Information System (INIS)

Morrow, R

2017-01-01

A general mechanism is presented for the dynamics and structure of ball lightning and for the maintenance of the ball lightning structure for several seconds. Results are obtained using a spherical geometry for air at atmospheric pressure, by solving the continuity equations for electrons, positive ions and negative ions coupled with Poisson’s equation. A lightning strike can generate conditions in the lightning channel with a majority of positive nitrogen ions, and a minority of negative oxygen ions and electrons. The calculations are initiated with electrons included; however, at the moderate ion densities chosen the electrons are rapidly lost to form negative ions, and after 1 µ s their influence on the ion dynamics is negligible. Further development after 1 µ s is followed using a simpler set of equations involving only positive ions and negative ions, but including ion diffusion. The space-charge electric field generated by the majority positive ions drives them from the centre of the distribution and drives the minority negative ions and electrons towards the centre of the distribution. In the central region the positive and negative ion distributions eventually overlap exactly and their space-charge fields cancel resulting in zero electric field, and the plasma ball formed is quite stable for a number of seconds. The formation of such plasma balls is not critically dependent on the initial diameter of the ion distributions, or the initial density of minority negative ions. The ion densities decrease relatively slowly due to mutual neutralization of positive and negative ions. The radiation from this neutralization process involving positive nitrogen ions and negative oxygen ions is not sufficient to account for the reported luminosity of ball lightning and some other source of luminosity is shown to be required; the plasma ball model used could readily incorporate other ions in order to account for the luminosity and range of colours reported for ball

Contribution of Visual Information about Ball Trajectory to Baseball Hitting Accuracy.

Directory of Open Access Journals (Sweden)

Takatoshi Higuchi

Full Text Available The contribution of visual information about a pitched ball to the accuracy of baseball-bat contact may vary depending on the part of trajectory seen. The purpose of the present study was to examine the relationship between hitting accuracy and the segment of the trajectory of the flying ball that can be seen by the batter. Ten college baseball field players participated in the study. The systematic error and standardized variability of ball-bat contact on the bat coordinate system and pitcher-to-catcher direction when hitting a ball launched from a pitching machine were measured with or without visual occlusion and analyzed using analysis of variance. The visual occlusion timing included occlusion from 150 milliseconds (ms after the ball release (R+150, occlusion from 150 ms before the expected arrival of the launched ball at the home plate (A-150, and a condition with no occlusion (NO. Twelve trials in each condition were performed using two ball speeds (31.9 m·s-1 and 40.3 m·s-1. Visual occlusion did not affect the mean location of ball-bat contact in the bat's long axis, short axis, and pitcher-to-catcher directions. Although the magnitude of standardized variability was significantly smaller in the bat's short axis direction than in the bat's long axis and pitcher-to-catcher directions (p < 0.001, additional visible time from the R+150 condition to the A-150 and NO conditions resulted in a further decrease in standardized variability only in the bat's short axis direction (p < 0.05. The results suggested that there is directional specificity in the magnitude of standardized variability with different visible time. The present study also confirmed the limitation to visual information is the later part of the ball trajectory for improving hitting accuracy, which is likely due to visuo-motor delay.

Heidelberg physicists report. Vol. 2. Reviews of research in physics and astronomy. Fundamental contributions to the physics of the atomic nuclei and the star atmospheres; Heidelberger Physiker berichten. Bd. 2. Rueckblicke auf Forschung in der Physik und Astronomie. Grundlegende Beitraege zur Physik der Atomkerne und der Sternatmosphaeren

Energy Technology Data Exchange (ETDEWEB)

Appenzeller, Immo; Dubbers, Dirk; Siebig, Hans-Georg; Winnacker, Albrecht (eds.)

2018-04-01

The following topics are dealt with: 50 years theoretical astrophysics, nuclear physics after the discovery of the shell model, from the small van de Graaf to the large HERA, from ''chamber physics'' to big research, reminiscences on physical research in Heidelberg. (HSI)

Knee Angle and Stride Length in Association with Ball Speed in Youth Baseball Pitchers

Directory of Open Access Journals (Sweden)

Bart van Trigt

2018-05-01

Full Text Available The purpose of this study was to determine whether stride length and knee angle of the leading leg at foot contact, at the instant of maximal external rotation of the shoulder, and at ball release are associated with ball speed in elite youth baseball pitchers. In this study, fifty-two elite youth baseball pitchers (mean age 15.2 SD (standard deviation 1.7 years pitched ten fastballs. Data were collected with three high-speed video cameras at a frequency of 240 Hz. Stride length and knee angle of the leading leg were calculated at foot contact, maximal external rotation, and ball release. The associations between these kinematic variables and ball speed were separately determined using generalized estimating equations. Stride length as percentage of body height and knee angle at foot contact were not significantly associated with ball speed. However, knee angles at maximal external rotation and ball release were significantly associated with ball speed. Ball speed increased by 0.45 m/s (1 mph with an increase in knee extension of 18 degrees at maximal external rotation and 19.5 degrees at ball release. In conclusion, more knee extension of the leading leg at maximal external rotation and ball release is associated with higher ball speeds in elite youth baseball pitchers.

The Heidelberg CSR: Stored Ion Beams in a Cryogenic Environment

International Nuclear Information System (INIS)

Wolf, A.; Hahn, R. von; Grieser, M.; Orlov, D. A.; Fadil, H.; Welsch, C. P.; Andrianarijaona, V.; Diehl, A.; Schroeter, C. D.; Crespo Lopez-Urrutia, J. R.; Weber, T.; Mallinger, V.; Schwalm, D.; Ullrich, J.; Rappaport, M.; Urbain, X.; Haberstroh, Ch.; Quack, H.; Zajfman, D.

2006-01-01

A cryogenic electrostatic ion storage ring CSR is under development at the Max-Planck Institute for Nuclear Physics in Heidelberg, Germany. Cooling of the ultrahigh vacuum chamber is envisaged to lead to extremely low pressures as demonstrated by cryogenic ion traps. The ring will apply electron cooling with electron beams of a few eV up to 200 eV. Through long storage times of 1000 s as well as through the low wall temperature, internal cooling of infrared-active molecular ions to their rotational ground state will be possible and their collisions with merged collinear beams of electrons and neutral atoms can be detected with high energy resolution. In addition storage of slow highly charged ions is foreseen. Using a fixed in-ring gas target and a reaction microscope, collisions of the stored ions at a speed of the order of the atomic unit can be kinematically reconstructed. The layout and the cryogenic concept are introduced

Dynamic analysis of double-row self-aligning ball bearings due to applied loads, internal clearance, surface waviness and number of balls

Science.gov (United States)

Zhuo, Yaobin; Zhou, Xiaojun; Yang, Chenlong

2014-11-01

In this paper, a three degrees of freedom (dof) model was established for a double-row self-aligning ball bearing (SABB) system, and was applied to study the dynamic behavior of the system during starting process and constant speed rotating process. A mathematical model was developed concerning stiffness and damping characteristics of the bearing, as well as three-dimensional applied load, rotor centrifugal force, etc. Balls and races were all considered as nonlinear springs, and the contact force between ball and race was calculated based on classic Hertzian elastic contact deformation theory and deformation compatibility theory. The changes of each ball's contact force and loaded angle of each row were taken into account. In order to solve the nonlinear dynamical equilibrium equations of the system, these equations were rewritten as differential equations and the fourth order Runge-Kutta method was used to solve the equations iteratively. In order to verify accuracy of the dynamical model and correctness of the numerical solution method, a kind of SABB-BRF30 was chosen for case studies. The effects of several important governing parameters, such as radial and axial applied loads, normal internal, inner and outer races waviness, and number of balls were investigated. These parametric studies led to a complete characterization of the shaft-bearing system vibration transmission. The research provided a theoretical reference for new type bearing design, shaft-bearing system kinetic analysis, optimal design, etc.

An overview of Ball Aerospace cryogen storage and delivery systems

International Nuclear Information System (INIS)

Marquardt, J; Keller, J; Mills, G; Schmidt, J

2015-01-01

Starting on the Gemini program in the 1960s, Beech Aircraft (now Ball Aerospace) has been designing and manufacturing dewars for a variety of cryogens including liquid hydrogen and oxygen. These dewars flew on the Apollo, Skylab and Space Shuttle spacecraft providing fuel cell reactants resulting in over 150 manned spaceflights. Since Space Shuttle, Ball has also built the liquid hydrogen fuel tanks for the Boeing Phantom Eye unmanned aerial vehicle. Returning back to its fuel cell days, Ball has designed, built and tested a volume-constrained liquid hydrogen and oxygen tank system for reactant delivery to fuel cells on unmanned undersea vehicles (UUVs). Herein past history of Ball technology is described. Testing has been completed on the UUV specific design, which will be described. (paper)

The Heidelberg circle: German inflections on the professionalization of Russian chemistry in the 1860s.

Science.gov (United States)

Gordin, Michael D

2008-01-01

The success of the "second importation" of science to Russia during the Great Reforms of the 1860s is illustrated by examining the extended postdoctoral study of chemists in Heidelberg. While there, they adapted the Russian intelligentsia institution of the "circle," or kruzhok, to cope with their alienation from the German culture they were confronting. Upon their return to Russia, they felt the lack of the communicative network they had established while abroad and reimported the kruzhok to serve as a central model for the formation of the Russian Chemical Society in 1868.

A Novel Generic Ball Recognition Algorithm Based on Omnidirectional Vision for Soccer Robots

Directory of Open Access Journals (Sweden)

Hui Zhang

2013-11-01

Full Text Available It is significant for the final goal of RoboCup to realize the recognition of generic balls for soccer robots. In this paper, a novel generic ball recognition algorithm based on omnidirectional vision is proposed by combining the modified Haar-like features and AdaBoost learning algorithm. The algorithm is divided into offline training and online recognition. During the phase of offline training, numerous sub-images are acquired from various panoramic images, including generic balls, and then the modified Haar-like features are extracted from them and used as the input of the AdaBoost learning algorithm to obtain a classifier. During the phase of online recognition, and according to the imaging characteristics of our omnidirectional vision system, rectangular windows are defined to search for the generic ball along the rotary and radial directions in the panoramic image, and the learned classifier is used to judge whether a ball is included in the window. After the ball has been recognized globally, ball tracking is realized by integrating a ball velocity estimation algorithm to reduce the computational cost. The experimental results show that good performance can be achieved using our algorithm, and that the generic ball can be recognized and tracked effectively.

The head tracks and gaze predicts: how the world's best batters hit a ball.

Directory of Open Access Journals (Sweden)

David L Mann

Full Text Available Hitters in fast ball-sports do not align their gaze with the ball throughout ball-flight; rather, they use predictive eye movement strategies that contribute towards their level of interceptive skill. Existing studies claim that (i baseball and cricket batters cannot track the ball because it moves too quickly to be tracked by the eyes, and that consequently (ii batters do not - and possibly cannot - watch the ball at the moment they hit it. However, to date no studies have examined the gaze of truly elite batters. We examined the eye and head movements of two of the world's best cricket batters and found both claims do not apply to these batters. Remarkably, the batters coupled the rotation of their head to the movement of the ball, ensuring the ball remained in a consistent direction relative to their head. To this end, the ball could be followed if the batters simply moved their head and kept their eyes still. Instead of doing so, we show the elite batters used distinctive eye movement strategies, usually relying on two predictive saccades to anticipate (i the location of ball-bounce, and (ii the location of bat-ball contact, ensuring they could direct their gaze towards the ball as they hit it. These specific head and eye movement strategies play important functional roles in contributing towards interceptive expertise.

Micro-ball lens structure fabrication based on drop on demand printing the liquid mold

Energy Technology Data Exchange (ETDEWEB)

Zhu, Xiaoyang, E-mail: zhuxy1026@163.com; Zhu, Li, E-mail: zhuli@njust.edu.cn; Chen, Hejuan; Yang, Lijun; Zhang, Weiyi

2016-01-15

Graphical abstract: - Highlights: • The glycerol micro-ball droplet was introduced to be as liquid mold to fabricate micro-ball lens. • A molding process was used to fabricate the micro-ball lens and the scales of them can be controlled. • The accurate molding process is mainly attributed to the ultrahigh adhesion of the treated substrate. • The micro-ball lenses with contact angle of 120° and 150° were fabricated, analyzed and discussed. - Abstract: In this paper, we demonstrated a simple micro-ball lens array (MBLA) fabrication method using a drop-on-demand (DOD) droplet printing technique and liquid mold. The micro-ball droplet array on the hydrophobic surface is used as the liquid mold to fabricate the MBLA. The ultrahigh adhesion force between the micro-ball droplet and the substrate is ascribed to the Wenzel state of the micro-ball droplet, while the replication process with low position error is attributed to the ultrahigh adhesion force between the micro-ball droplet and the substrate and the high viscosity of the micro-ball droplet and polydimethylsiloxane (PDMS) liquid. The micro-ball lenses (MBLs) with a contact angle of 120° and 150° were fabricated and the important fabrication details were discussed. The optical performance and scanning electron microscope (SEM) data of the MBLs showed that the MBLs had high quality surface morphology and good optical performance.

Predicting brain acceleration during heading of soccer ball

Science.gov (United States)

Taha, Zahari; Hasnun Arif Hassan, Mohd; Azri Aris, Mohd; Anuar, Zulfika

2013-12-01

There has been a long debate whether purposeful heading could cause harm to the brain. Studies have shown that repetitive heading could lead to degeneration of brain cells, which is similarly found in patients with mild traumatic brain injury. A two-degree of freedom linear mathematical model was developed to study the impact of soccer ball to the brain during ball-to-head impact in soccer. From the model, the acceleration of the brain upon impact can be obtained. The model is a mass-spring-damper system, in which the skull is modelled as a mass and the neck is modelled as a spring-damper system. The brain is a mass with suspension characteristics that are also defined by a spring and a damper. The model was validated by experiment, in which a ball was dropped from different heights onto an instrumented dummy skull. The validation shows that the results obtained from the model are in a good agreement with the brain acceleration measured from the experiment. This findings show that a simple linear mathematical model can be useful in giving a preliminary insight on what human brain endures during a ball-to-head impact.

The methodology of composing the exercises system with fit balls.

Directory of Open Access Journals (Sweden)

Voronov N.P.

2011-02-01

Full Text Available The original methodology of composing the exercises system with fit balls was considered. More than 10 publications were analysed. On the lesson with fit balls the problem was revealed. In the experiment took part 30 students at the age from 18 till 21. All the famous exercises were systematized. As a result, a big attractiveness and assimilability of the proposed complex was revealed. The effectiveness of the complex of physical exercises with fit balls for students was proved.

Stimulated leaks found with SmartBall tool

Energy Technology Data Exchange (ETDEWEB)

Anon.

2011-05-15

Pure Technologies has developed a SmartBall leak detection tool which can be used in oil and gas pipelines. This tool contains acoustic sensors which listen for leaks and other problems in pipelines. Pig tracking units are used to track the tool along with receivers positioned on the pipe. With these technologies, SmartBall is able to detect small leaks that conventional methods would not detect and to assess their location accurately. Two runs on a Petrobras pipeline in Brazil highlighted the effectiveness of this technology, detecting three simulated leaks as small as 240mL/min. In addition, this system can give an estimation of the leak rate and traverse non piggable pipelines. Software is then used to analyze data and generate a report giving the size and location of the leaks identified. SmartBall is a technology capable of detecting small leaks and locating them in all sorts of oil and gas pipelines.

Petrography and microanalysis of Pennsylvanian coal-ball concretions (Herrin Coal, Illinois Basin, USA): Bearing on fossil plant preservation and coal-ball origins

Science.gov (United States)

Siewers, Fredrick D.; Phillips, Tom L.

2015-11-01

Petrographic analyses of 25 coal balls from well-studied paleobotanical profiles in the Middle Pennsylvanian Herrin Coal (Westphalian D, Illinois Basin) and five select coal balls from university collections, indicate that Herrin Coal-ball peats were permineralized by fibrous and non-fibrous carbonates. Fibrous carbonates occur in fan-like to spherulitic arrays in many intracellular (within tissue) pores, and are best developed in relatively open extracellular (between plant) pore spaces. Acid etched fibrous carbonates appear white under reflected light and possess a microcrystalline texture attributable to abundant microdolomite. Scanning electron microscopy, X-ray diffraction, and electron microprobe analysis demonstrate that individual fibers have a distinct trigonal prism morphology and are notable for their magnesium content (≈ 9-15 mol% MgCO3). Non-fibrous carbonates fill intercrystalline spaces among fibers and pores within the peat as primary precipitates and neomorphic replacements. In the immediate vicinity of plant cell walls, non-fibrous carbonates cut across fibrous carbonates as a secondary, neomorphic phase attributed to coalification of plant cell walls. Dolomite occurs as diagenetic microdolomite associated with the fibrous carbonate phase, as sparite replacements, and as void-filling cement. Maximum dolomite (50-59 wt.%) is in the top-of-seam coal-ball zone at the Sahara Mine, which is overlain by the marine Anna Shale. Coal-ball formation in the Herrin Coal began with the precipitation of fibrous high magnesium calcite. The trigonal prism morphology of the carbonate fibers suggests rapid precipitation from super-saturated, meteoric pore waters. Carbonate precipitation from marine waters is discounted on the basis of stratigraphic, paleobotanical, and stable isotopic evidence. Most non-fibrous carbonate is attributable to later diagenetic events, including void-fill replacements, recrystallization, and post-depositional fracture fills. Evidence

Effect of ball-milling to the surface morphology of CaCO3

Science.gov (United States)

Sulimai, N. H.; Rani, Rozina Abdul; Khusaimi, Z.; Abdullah, S.; Salifairus, M. J.; Alrokayan, Salman; Khan, Haseeb; Rusop, M.

2018-05-01

Calcium Carbonate can be synthesized in many approaches. This work studied on the physical changes to Calcium Carbonate (CaCO3) by ball-milling activity in different parameters; number of ball; collision duration; revolution per minute (RPM). Zirconia balls were used in the work because it has the best durability to withstand ball-milling conditions set. Industrial grade CaCO3 particles that were run in aforementioned parameters were characterized by Field Emission Scanning Electron Microscope (FE-SEM) to study the physical changes on the size and surface of the CaCO3. They were also characterized with Fourier Transform Infra-red Spectroscopy (FTIR) were fingerprint of CaCO3 regions were identified and any changes in the band position and intensity were discussed. Number of Zirconia balls and collision duration is directly proportional to the absorbance intensity whereas it is inversely proportional for the rpm. The best number of parameters producing the highest Absorbance is 100 Zirconia balls in duration of 1 hour and 100rpm.

Helical tomotherapy. Experiences of the first 150 patients in Heidelberg

Energy Technology Data Exchange (ETDEWEB)

Sterzing, F.; Schubert, K.; Sroka-Perez, G.; Kalz, J.; Debus, J.; Herfarth, K. [Dept. of Radiation Oncology, Univ. of Heidelberg (Germany)

2008-01-15

Background and purpose: helical tomotherapy was introduced into clinical routine at the Department of Radiation Oncology, University Hospital of Heidelberg, Germany, in July 2006. This report is intended to describe the experience with the first 150 patients treated with helical tomotherapy. Patient selection, time effort, handling of daily image guidance with megavoltage (MV) CT, and quality of radiation plans shall be assessed. Patients and methods: between July 2006 and May 2007, 150 patients were treated with helical tomotherapy in the University Hospital of Heidelberg. Mean age was 60 years with a minimum of 30 years and a maximum of 85 years. 79 of these patients received radiotherapy as a part of multimodal treatment pre- or postoperatively, 17 patients received treatment as a combined radiochemotherapy. 76% were treated with curative intent. Radiotherapy sites were central nervous system (n = 7), head and neck (n = 28), thoracic (n = 37), abdominal (n = 58) and skeletal system (n = 20). Most common tumor entities were prostate cancer (n = 28), breast cancer (n = 17), gastrointestinal tumors (n = 19), pharyngeal carcinoma (n = 14), lymphoma (n = 13), metastatic disease (bone n = 14, liver n = 6, lung n = 4, lymph node n = 2), sarcoma (n = 8), malignant pleural mesothelioma (n = 5), ovarian cancer treated with whole abdominal irradiation (n = 4), lung cancer (n = 3), skin malignancies (n = 3), chordoma (n = 2), meningioma (n = 2), one ependymoma and one medulloblastoma treated with craniospinal axis irradiation (n = 2), and others (n = 4). Nine patients were treated with single-fraction radiosurgery, nine with image-guided spinal reirradiation, and twelve patients were treated at multiple targets simultaneously. A pretreatment MV-CT scan was performed in 98.2% of the 3,026 fractions applied. After matching with the kilovoltage planning CT, corrections for translations and rotation around longitudinal axis (roll) were done. Results: mean time on table was 24

The head tracks and gaze predicts: how the world's best batters hit the ball

NARCIS (Netherlands)

Mann, D.L.; Spratford, W.; Abernethy, B.

2013-01-01

Hitters in fast ball-sports do not align their gaze with the ball throughout ball-flight; rather, they use predictive eye movement strategies that contribute towards their level of interceptive skill. Existing studies claim that (i) baseball and cricket batters cannot track the ball because it moves

The Energy Cost of Running with the Ball in Soccer.

Science.gov (United States)

Piras, Alessandro; Raffi, Milena; Atmatzidis, Charalampos; Merni, Franco; Di Michele, Rocco

2017-11-01

Running with the ball is a soccer-specific activity frequently used by players during match play and training drills. Nevertheless, the energy cost (EC) of on-grass running with the ball has not yet been determined. The purpose of this study was therefore to assess the EC of constant-speed running with the ball, and to compare it with the EC of normal running. Eight amateur soccer players performed two 6- min runs at 10 km/h on artificial turf, respectively with and without the ball. EC was measured with indirect calorimetry and, furthermore, estimated with a method based on players' accelerations measured with a GPS receiver. The EC measured with indirect calorimetry was higher in running with the ball (4.60±0.42 J/kg/m) than in normal running (4.19±0.33 J/kg/m), with a very likely moderate difference between conditions. Instead, a likely small difference was observed between conditions for EC estimated from GPS data (4.87±0.07 vs. 4.83±0.08 J/kg/m). This study sheds light on the energy expenditure of playing soccer, providing relevant data about the EC of a typical soccer-specific activity. These findings may be a reference for coaches to precisely determine the training load in drills with the ball, such as soccer-specific circuits or small-sided games. © Georg Thieme Verlag KG Stuttgart · New York.

The coefficient of restitution of pressurized balls: a mechanistic model

Science.gov (United States)

Georgallas, Alex; Landry, Gaëtan

2016-01-01

Pressurized, inflated balls used in professional sports are regulated so that their behaviour upon impact can be anticipated and allow the game to have its distinctive character. However, the dynamics governing the impacts of such balls, even on stationary hard surfaces, can be extremely complex. The energy transformations, which arise from the compression of the gas within the ball and from the shear forces associated with the deformation of the wall, are examined in this paper. We develop a simple mechanistic model of the dependence of the coefficient of restitution, e, upon both the gauge pressure, P_G, of the gas and the shear modulus, G, of the wall. The model is validated using the results from a simple series of experiments using three different sports balls. The fits to the data are extremely good for P_G > 25 kPa and consistent values are obtained for the value of G for the wall material. As far as the authors can tell, this simple, mechanistic model of the pressure dependence of the coefficient of restitution is the first in the literature. *%K Coefficient of Restitution, Dynamics, Inflated Balls, Pressure, Impact Model

In Vitro Antimicrobial Activity of Gel Containing the Herbal Ball Extract against Propionibacterium acnes

Directory of Open Access Journals (Sweden)

Chutima Jantarat

2018-02-01

Full Text Available The herbal ball has been used as a Thai traditional medicine for relieving many diseases including acne. However, the application process of the herbal ball in practice is complicated and time consuming. The objective of this work was to utilize an herbal ball extract to formulate a gel to reach a more favorable use of the herbal ball for acne treatment. An herbal ball consisting of Andrographis paniculata, Centella asiatica, the Benchalokawichian remedy and the stem bark powder of Hesperethusa crenulata was prepared. The obtained herbal ball was steamed and squeezed to obtain the extract. Gel formulations containing the herbal ball extract at concentrations of 0.1, 1 and 5% w/w were prepared based on a carbomer gel. The herbal ball extract had antioxidant (EC50 = 219.27 ± 36.98 μg/mL and anti Propionibacterium acnes activities (minimum inhibitory concentration (MIC and minimum bactericidal concentration (MBC = 31.25 μg/mL. The 5% w/w gel formulation had antimicrobial activity against P. acnes, showing an inhibition zone value of 10.00 ± 1.00 mm. This indicates that the developed gel formulation has potential for acne treatment. In comparison to the traditional method of herbal ball usage, the application of herbal ball extract in the form of gel should be more convenient to use.

A necrotic lung ball caused by co-infection with Candida and Streptococcus pneumoniae

Directory of Open Access Journals (Sweden)

Yokoyama T

2011-12-01

Full Text Available Toshinobu Yokoyama, Jun Sasaki, Keita Matsumoto, Chie Koga, Yusuke Ito, Yoichiro Kaku, Morihiro Tajiri, Hiroki Natori, Masashi HirokawaDivision of Respirology, Neurology and Rheumatology, Department of Internal Medicine, Kurume University School of Medicine, Kurume, JapanIntroduction: A necrotic lung ball is a rare radiological feature that is sometimes seen in cases of pulmonary aspergillosis. This paper reports a rare occurrence of a necrotic lung ball in a young male caused by Candida and Streptococcus pneumoniae.Case report: A 28-year-old male with pulmonary candidiasis was found to have a lung ball on computed tomography (CT of the chest. The patient was treated with ß-lactams and itraconazole and then fluconazole, which improved his condition (as found on a following chest CT scan and serum ß-D-glucan level. The necrotic lung ball was suspected to have been caused by co-infection with Candida and S. pneumoniae.Conclusion: A necrotic lung ball can result from infection by Candida and/or S. pneumoniae, indicating that physicians should be aware that patients may still have a fungal infection of the lungs that could result in a lung ball, even when they do not have either Aspergillus antibodies or antigens.Keywords: lung ball, necrotic lung ball, Candida, Streptococcus pneumoniae

The Heidelberg Appendicitis Score Predicts Perforated Appendicitis in Children.

Science.gov (United States)

Boettcher, Michael; Günther, Patrick; Breil, Thomas

2017-10-01

In the future, surgical management of pediatric appendicitis might become limited to nonperforating appendicitis. Thus, it becomes increasingly important to differentiate advanced from simple appendicitis and to predict perforated appendicitis among a group of children with right-sided abdominal pain, which was the aim of this study. An institutionally approved, single-center retrospective analysis of all patients with appendectomy from January 2009 to December 2010 was conducted. All diagnostic aspects were evaluated to identify predictors and differentiators of perforated appendicitis. In 2 years, 157 children suffered from appendicitis. Perforation occurred in 47 (29.9%) of the patients. C-reactive protein (CRP) levels higher than 20 mg/dL ( P = .037) and free abdominal fluid on ultrasonography ( P = .031) are the most important features to differentiate perforated from simple appendicitis. Moreover, all children with perforation had a positive Heidelberg Appendicitis Score (HAS). A negative HAS excludes perforation in all cases (negative predictive value = 100%). Perforated appendicitis can be ruled out by the HAS. In a cohort with right-sided abdominal pain, perforation should be considered in children with high CRP levels and free fluids or abscess formation on ultrasound.

Soccer ball lift coefficients via trajectory analysis

International Nuclear Information System (INIS)

Goff, John Eric; Carre, Matt J

2010-01-01

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

Soccer ball lift coefficients via trajectory analysis

Energy Technology Data Exchange (ETDEWEB)

Goff, John Eric [Department of Physics, Lynchburg College, Lynchburg, VA 24501 (United States); Carre, Matt J, E-mail: goff@lynchburg.ed [Department of Mechanical Engineering, University of Sheffield, Sheffield S1 3JD (United Kingdom)

2010-07-15

We performed experiments in which a soccer ball was launched from a machine while two high-speed cameras recorded portions of the trajectory. Using the trajectory data and published drag coefficients, we extracted lift coefficients for a soccer ball. We determined lift coefficients for a wide range of spin parameters, including several spin parameters that have not been obtained by today's wind tunnels. Our trajectory analysis technique is not only a valuable tool for professional sports scientists, it is also accessible to students with a background in undergraduate-level classical mechanics.

Simulating fullerene ball bearings of ultra-low friction

International Nuclear Information System (INIS)

Li Xiaoyan; Yang Wei

2007-01-01

We report the direct molecular dynamics simulations for molecular ball bearings composed of fullerene molecules (C 60 and C 20 ) and multi-walled carbon nanotubes. The comparison of friction levels indicates that fullerene ball bearings have extremely low friction (with minimal frictional forces of 5.283 x 10 -7 and 6.768 x 10 -7 nN/atom for C 60 and C 20 bearings) and energy dissipation (lowest dissipation per cycle of 0.013 and 0.016 meV/atom for C 60 and C 20 bearings). A single fullerene inside the ball bearings exhibits various motion statuses of mixed translation and rotation. The influences of the shaft's distortion on the long-ranged potential energy and normal force are discussed. The phonic dissipation mechanism leads to a non-monotonic function between the friction and the load rate for the molecular bearings

Properties of the Sodium Naproxen-Lactose-Tetrahydrate Co-Crystal upon Processing and Storage

DEFF Research Database (Denmark)

Sovago, Ioana; Wang, Wenbo; Qiu, Danwen

2016-01-01

naproxen-lactose-tetrahydrate co-crystal and the co-amorphous mixture of sodium, naproxen, and lactose was investigated. The structure of the co-crystal is described using single-crystal X-ray diffraction. The structural analysis revealed a monoclinic lattice, space group P21, with the asymmetric unit...... containing one molecule of lactose, one of naproxen, sodium, and four water molecules. Upon heating, it was observed that the co-crystal transforms into a co-amorphous system due to the loss of its crystalline bound water. Dehydration and co-amorphization were studied using synchrotron X-ray radiation...... and thermogravimetric analysis (TGA). Subsequently, different processing techniques (ball milling, spray drying, and dehydration) were used to prepare the co-amorphous mixture of sodium, naproxen, and lactose. X-ray powder diffraction (XRPD) revealed the amorphous nature of the mixtures after preparation. Differential...

Visual Illusions and the Control of Ball Placement in Goal-Directed Hitting

Science.gov (United States)

Caljouw, Simone R.; Van der Kamp, John; Savelsbergh, Geert J. P.

2010-01-01

When hitting, kicking, or throwing balls at targets, online control in the target area is impossible. We assumed this lack of late corrections in the target area would induce an effect of a single-winged Muller-Lyer illusion on ball placement. After extensive practice in hitting balls to different landing locations, participants (N = 9) had to hit…

Linearly convergent stochastic heavy ball method for minimizing generalization error

KAUST Repository

Loizou, Nicolas; Richtarik, Peter

2017-01-01

In this work we establish the first linear convergence result for the stochastic heavy ball method. The method performs SGD steps with a fixed stepsize, amended by a heavy ball momentum term. In the analysis, we focus on minimizing the expected loss

IceCube potential for detecting Q-ball dark matter in gauge mediation

International Nuclear Information System (INIS)

Kasuya, Shinta; Kawasaki, Masahiro; Yanagida, Tsutomu T.

2015-01-01

We study Q-ball dark matter in gauge-mediated supersymmetry breaking, and seek the possibility of detection in the IceCube experiment. We find that the Q balls would be the dark matter in the parameter region different from that for gravitino dark matter. In particular, the Q ball is a good dark matter candidate for low reheating temperature, which may be suitable for the Affleck–Dine baryogenesis and/or nonthermal leptogenesis. Dark matter Q balls are detectable by IceCube-like experiments in the future, which is a peculiar feature compared to the case of gravitino dark matter

An assessment of dioxin levels in processed ball clay from the United States

Energy Technology Data Exchange (ETDEWEB)

Ferrario, J.; Byrne, C. [USEPA, Stennis Space Ctr. Mississippi (United States); Schaum, J. [USEPA, Washington, DC (United States)

2004-09-15

Introduction The presence of dioxin-like compounds in ball clay was discovered in 1996 as a result of an investigation to determine the sources of elevated levels of dioxin found in two chicken fat samples from a national survey of poultry. The investigation indicated that soybean meal added to chicken feed was the source of dioxin contamination. Further investigation showed that the dioxin contamination came from the mixing of a natural clay known as ''ball clay'' with the soybean meal as an anti-caking agent. The FDA subsequently discontinued the use of contaminated ball clay as an anti-caking agent in animal feeds. The source of the dioxins found in ball clay has yet to be established. A comparison of the characteristic dioxin profile found in ball clay to those of known anthropogenic sources from the U.S.EPA Source Inventory has been undertaken, and none of those examined match the features found in the clays. These characteristic features together with the fact that the geologic formations in which the clays are found are ancient suggest a natural origin for the dioxins. The plasticity of ball clays makes them an important commercial resource for a variety of commercial uses. The percentage of commercial uses of ball clay in 2000 included: 29% for floor and wall tile, 24% for sanitary ware, 10% pottery, and 37% for other industrial and commercial uses. The total mining of ball clay in the U.S. for 2003 was 1.12 million metric tons. EPA is examining the potential for the environmental release of dioxins from the processing/use of ball clays and evaluating potential exposure pathways. Part of this overall effort and the subject of this study includes the analysis of dioxin levels found in commercially available ball clays commonly used in ceramic art studios.

Numerical simulation and analysis of ball valve three-dimensional flow based on CFD

International Nuclear Information System (INIS)

Zhang, S C; Zhang, Y L; Fang, Z M

2012-01-01

The new rotor oil-gas mixture pump that added ball valves in its export is a kind of innovative products, which can better adapt to the oil and gas mixed condition. In order to explore the rule of flow field in the export ball valve of new rotor oil-gas mixture pump, established the 3 d model of ball valve flow field was established. Using the FLUENT software, combining the standard k-ε turbulent model with multiphase flow technology and adopting the SIMPLE algorithm to simulate the 3 d gas-liquid two phase flow field in export ball valve of new rotor oil-gas mixture pump. In the different conditions that the volume of gas rate was 25%, 50%, 75%, through analyzing the velocity field, stress field and the distribution of the liquid and gas with the ball valve open height respectively at 3mm, 5mm, 7mm. Discussed how open height and different volume of gas rate to influence the field in export ball valve in the process of gas-liquid mixing was discussed. The simulation results showed that the greater the open height, the smaller the difference pressure of ball valve; the gap velocity decreasing with the open height increasing. The gas is mainly distributed in the vicinity of the valve ball in the process of gas-liquid mixing. The gas liquid ratio has a little effect on the gap velocity in the same open height. The results showed the flow field forms in the ball valve directly, to a certain degree, it had released the rules of gas-liquid flow in the valve and provided the theoretical guidance for design and optimization of the new rotor oil-gas mixture pump export ball valve.

Size doesn't really matter: ambiguity aversion in Ellsberg urns with few balls.

Science.gov (United States)

Pulford, Briony D; Colman, Andrew M

2008-01-01

When attempting to draw a ball of a specified color either from an urn containing 50 red balls and 50 black balls or from an urn containing an unknown ratio of 100 red and black balls, a majority of decision makers prefer the known-risk urn, and this ambiguity aversion effect violates expected utility theory. In an experimental investigation of the effect of urn size on ambiguity aversion, 149 participants showed similar levels of aversion when choosing from urns containing 2, 10, or 100 balls. The occurrence of a substantial and significant ambiguity aversion effect even in the smallest urn suggests that influential theoretical interpretations of ambiguity aversion may need to be reconsidered.

The intensity feedback system at Heidelberg Ion-Beam Therapy Centre

Energy Technology Data Exchange (ETDEWEB)

Schoemers, Christian, E-mail: christian.schoemers@med.uni-heidelberg.de; Feldmeier, Eike; Naumann, Jakob; Panse, Ralf; Peters, Andreas; Haberer, Thomas

2015-09-21

At Heidelberg Ion-Beam Therapy Centre (HIT), more than 2500 tumour patients have been treated with charged particle beams since 2009 using the raster scanning method. The tumour is irradiated slice-by-slice, each slice corresponding to a different beam energy. For the particle dose of each raster point the pre-irradiation by more distal slices has to be considered. This leads to highly inhomogeneous dose distributions within one iso-energy slice. The particles are extracted from the synchrotron via transverse RF knock-out. A pure feed forward control cannot take into account fluence inhomogeneities or deal with intensity fluctuations. So far, fluctuations have been counteracted by a reduced scanning velocity. We now added a feedback loop to the extraction system. The dose monitoring ionisation chambers in front of the patient have been coupled to the extraction device in the synchrotron. Characterization and implementation of the intensity feedback system into the HIT facility is described here. By its implementation the treatment time has been reduced by 10% in average.

Space Shuttle Orbital Maneuvering Subsystem (OMS) Engine Propellant Leakage Ball-Valve Shaft Seals

Science.gov (United States)

Lueders, Kathy; Buntain, Nick; Fries, Joseph (Technical Monitor)

1999-01-01

Evidence of propellant leakage across ball-valve shaft seals has been noted during the disassembly of five flight engines and one test engine at the NASA Lyndon B. Johnson Space Center, White Sands Test Facility. Based on data collected during the disassembly of these five engines, the consequences of propellant leakage across the ball-valve shaft seals can be divided into four primary areas of concern: Damage to the ball-valve pinion shafts, damage to sleeved bearings inside the ball-valve and actuator assemblies, degradation of the synthetic rubber o-rings used in the actuator assemblies, and corrosion and degradation to the interior of the actuator assemblies. The exact time at which leakage across the ball-valve shaft seals occurs has not been determined, however, the leakage most likely occurs during engine firings when, depending on the specification used, ball-valve cavity pressures range as high as 453 to 550 psia. This potential pressure range for the ball-valve cavities greatly exceeds the acceptance leakage test pressure of 332 psia. Since redesign and replacement of the ball-valve shaft seals is unlikely, the near term solution to prevent damage that occurs from shaft-seal leakage is to implement a routine overhaul and maintenance program for engines in the fleet. Recommended repair, verification, and possible preventative maintenance measures are discussed in the paper.

Biaxial testing for nuclear grade graphite by ball on three balls assessment

International Nuclear Information System (INIS)

Mohd Reusmaazran Yusof; Yusof Abdullah

2012-01-01

Nuclear grade (high-purity) graphite for fuel element and moderator material in Advanced Gas Cooling Reactors (AGR) displays large scatter in strength and a non-linear stress-strain response from the damage accumulation. These responses can be characterized as quasi-brittle behaviour. Current assessments of fracture in core graphite components are based on the linear elastic approximation and thus represent a major assumption. The quasi-brittle behaviour gives challenge to assess the real nuclear graphite component. The selected test method would help to bridge the gap between microscale to macro-scale in real reactor component. The small scale tests presented here can contribute some statistical data to manifests the failure in real component. The evaluation and choice of different solution design of biaxial test will be discussed in this paper. The ball on-three ball test method was used for assessment test follows by numerous of analytical method. The results shown that biaxial strength of the EY9 grade graphite depends on the method used for evaluation. Some of the analytical methods use to calculate biaxial strength were found not to be valid and therefore should not be used to assess the mechanical properties of nuclear graphite. (author)

CFD Study of Drag and Lift of Sepak Takraw Ball at Different Face Orientations

Directory of Open Access Journals (Sweden)

Abdul Syakir Abdul Mubin

2015-01-01

Full Text Available There have been a significant number of researches on computational fluid dynamic (CFD analysis of balls used in sports such as golf balls, tennis balls, and soccer balls. Sepak takraw is a high speed court game predominantly played in Southeast Asia using mainly the legs and head. The sepak takraw ball is unique because it is not enclosed and made of woven plastic. Hence a study of its aerodynamicswould give insight into its behaviour under different conditions of play. In this study the dynamics of the fluid around a static sepak takraw ball was investigated at different wind speeds for three different orientations using CFD. It was found that although the drag did not differ very much, increasing the wind velocity causes an increase in drag. The lift coefficientvaries as the velocity increases and does not show a regular pattern. The drag and lift coefficients are influenced by the orientation of the sepak takraw ball.

Exact solutions, energy, and charge of stable Q-balls

Energy Technology Data Exchange (ETDEWEB)

Bazeia, D.; Marques, M.A. [Universidade Federal da Paraiba, Departamento de Fisica, Joao Pessoa, PB (Brazil); Menezes, R. [Universidade Federal da Paraiba, Departamento de Ciencias Exatas, Rio Tinto, PB (Brazil); Universidade Federal de Campina Grande, Departamento de Fisica, Campina Grande, PB (Brazil)

2016-05-15

In this work we deal with nontopological solutions of the Q-ball type in two spacetime dimensions. We study models of current interest, described by a Higgs-like and other, similar potentials which unveil the presence of exact solutions. We use the analytic results to investigate how to control the energy and charge to make the Q-balls stable. (orig.)

International outbreak investigation of Salmonella Heidelberg associated with in-flight catering.

Science.gov (United States)

Rebolledo, J; Garvey, P; Ryan, A; O'Donnell, J; Cormican, M; Jackson, S; Cloak, F; Cullen, L; Swaan, C M; Schimmer, B; Appels, R W; Nygard, K; Finley, R; Sreenivasan, N; Lenglet, A; Gossner, C; McKeown, P

2014-04-01

Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10.2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

International outbreak investigation of Salmonella Heidelberg associated with in-flight catering.

LENUS (Irish Health Repository)

Rebolledo, J

2013-07-26

SUMMARY Rapid and wide dispersal of passengers after flights makes investigation of flight-related outbreaks challenging. An outbreak of Salmonella Heidelberg was identified in a group of Irish travellers returning from Tanzania. Additional international cases sharing the same flight were identified. Our aim was to determine the source and potential vehicles of infection. Case-finding utilized information exchange using experts\\' communication networks and national surveillance systems. Demographic, clinical and food history information was collected. Twenty-five additional cases were identified from Ireland, The Netherlands, Norway, USA and Canada. We conducted a case-control study which indicated a significant association between illness and consumption of milk tart (OR 10·2) and an egg dish (OR 6) served on-board the flight. No food consumed before the flight was associated with illness. Cases from countries other than Ireland provided supplementary information that facilitated the identification of likely vehicles of infection. Timely, committed international collaboration is vital in such investigations.

Low Energy Electron Cooling and Accelerator Physics for the Heidelberg CSR

International Nuclear Information System (INIS)

Fadil, H.; Grieser, M.; Hahn, R. von; Orlov, D.; Schwalm, D.; Wolf, A.; Zajfman, D.

2006-01-01

The Cryogenic Storage Ring (CSR) is currently under construction at MPI-K in Heidelberg. The CSR is an electrostatic ring with a total circumference of about 34 m, straight section length of 2.5 m and will store ions in the 20 ∼ 300 keV energy range (E/Q). The cryogenic system in the CSR is expected to cool the inner vacuum chamber down to 2 K. The CSR will be equipped with an electron cooler which has also to serve as an electron target for high resolution recombination experiments. In this paper we present the results of numerical investigations of the CSR lattice with finite element calculations of the deflection and focusing elements of the ring. We also present a layout of the CSR electron cooler which will have to operate in low energy mode to cool 20 keV protons in the CSR, as well as numerical estimations of the cooling times to be expected with this device

Molecular characterization of Salmonella Paratyphi B dT+ and Salmonella Heidelberg from poultry and retail chicken meat in Colombia by pulsed-field gel electrophoresis

Science.gov (United States)

Salmonella Paratyphi B dT+ variant (also termed Salmonella Java) and Salmonella Heidelberg are human pathogens frequently isolated from poultry. As a step towards implementing the Colombian Integrated Program for Antimicrobial Resistant Surveillance (COIPARS), this study characterized molecular patt...

Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy

Directory of Open Access Journals (Sweden)

Christoph Maria Krick

2015-02-01

Full Text Available Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-minutes sessions of individualized therapy implemented over one week. Clinical improvement and long-term effects over several years have previously been published. However the underlying neural basis of the therapy’s success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG and healthy active controls (AC. Non-treated patients were also included as passive controls (PTC. As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (two-way ANOVA revealed structural gray matter (GM increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG versus AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be

Cortical reorganization in recent-onset tinnitus patients by the Heidelberg Model of Music Therapy

Science.gov (United States)

Krick, Christoph M.; Grapp, Miriam; Daneshvar-Talebi, Jonas; Reith, Wolfgang; Plinkert, Peter K.; Bolay, Hans Volker

2015-01-01

Pathophysiology and treatment of tinnitus still are fields of intensive research. The neuroscientifically motivated Heidelberg Model of Music Therapy, previously developed by the German Center for Music Therapy Research, Heidelberg, Germany, was applied to explore its effects on individual distress and on brain structures. This therapy is a compact and fast application of nine consecutive 50-min sessions of individualized therapy implemented over 1 week. Clinical improvement and long-term effects over several years have previously been published. However, the underlying neural basis of the therapy's success has not yet been explored. In the current study, the therapy was applied to acute tinnitus patients (TG) and healthy active controls (AC). Non-treated patients were also included as passive controls (PTC). As predicted, the therapeutic intervention led to a significant decrease of tinnitus-related distress in TG compared to PTC. Before and after the study week, high-resolution MRT scans were obtained for each subject. Assessment by repeated measures design for several groups (Two-Way ANOVA) revealed structural gray matter (GM) increase in TG compared to PTC, comprising clusters in precuneus, medial superior frontal areas, and in the auditory cortex. This pattern was further applied as mask for general GM changes as induced by the therapy week. The therapy-like procedure in AC also elicited similar GM increases in precuneus and frontal regions. Comparison between structural effects in TG vs. AC was calculated within the mask for general GM changes to obtain specific effects in tinnitus patients, yielding GM increase in right Heschl's gyrus, right Rolandic operculum, and medial superior frontal regions. In line with recent findings on the crucial role of the auditory cortex in maintaining tinnitus-related distress, a causative relation between the therapy-related GM alterations in auditory areas and the long-lasting therapy effects can be assumed. PMID:25745385

Attempted - to -Phase Conversion of Croconic Acid via Ball Milling

Science.gov (United States)

2017-05-18

ARL-TN-0824 MAY 2017 US Army Research Laboratory Attempted α- to β-Phase Conversion of Croconic Acid via Ball Milling by...Laboratory Attempted α- to β-Phase Conversion of Croconic Acid via Ball Milling by Steven W Dean, Rose A Pesce-Rodriguez, and Jennifer A Ciezak...

Study of memory effects in polymer dispersed liquid crystal films

International Nuclear Information System (INIS)

Han, Jinwoo

2006-01-01

In this work, we have studied the memory effects in polymer dispersed liquid crystal films. We found that optical responses, such as the memory effects, of the films depended strongly on the morphology. For example, memory effects were observed for films with polymer ball morphologies; however, only weak hysteresis effects were observed for films with droplet morphologies. In particular, a stronger memory effect was observed for films with more complicated polymer ball structures. Coincidentally, T TE , the temperature at which the memory state is thermally erased, was generally higher for the films exhibiting a stronger memory effect. In addition, studies of the temporal evolution of the films show that the memory effects become stronger after films have been kept on the shelf for a period of time. This change is likely to be associated with a modification of surface anchoring properties at the LC-polymer interface.

Development of Stick and Ball Sports on Gateball

Directory of Open Access Journals (Sweden)

Indriyanti

2017-10-01

Full Text Available The purpose of this research is to make product design development of stick and ball sports in gateball. The approach used in this study is a method of Research and Development. The subject of this research is the Central Java on gateball club event gateball in Semarang and Yogyakarta. Experts and expert expert gateball expert in mechanical engineering. The data analysis phase the work field, and the data analysis stage include observation, observation, interviews, and documentation of the test kefektifan products, expert judgment expert expert gateball and expert mechanical engineering expert. The results of this research are stick and ball exercise for beginner players gateball gateball. The result of the validator 3 expert expert from the expert gateball and expert mechanical engineering product validation data beginning the first phase obtained a score above 73 definitions of the criteria of “good”, on the second stage of the product validation data obtained a score above the 81 criteria for “excellent”. The results of the interviews to the development of gateball players 19 stick and ball gateball can not be used to play in a match and can be used for subsequent exercises but for beginners a product development tool model stick and ball gateball “ INC. “can be used to enhance the ability of basic techniques in motion game for players, gateball.

Investigation of a Ball Screw Feed Drive System Based on Dynamic Modeling for Motion Control

Directory of Open Access Journals (Sweden)

Yi-Cheng Huang

2017-06-01

Full Text Available This paper examines the frequency response relationship between the ball screw nut preload, ball screw torsional stiffness variations and table mass effect for a single-axis feed drive system. Identification for the frequency response of an industrial ball screw drive system is very important for the precision motion when the vibration modes of the system are critical for controller design. In this study, there is translation and rotation modes of a ball screw feed drive system when positioning table is actuated by a servo motor. A lumped dynamic model to study the ball nut preload variation and torsional stiffness of the ball screw drive system is derived first. The mathematical modeling and numerical simulation provide the information of peak frequency response as the different levels of ball nut preload, ball screw torsional stiffness and table mass. The trend of increasing preload will indicate the abrupt peak change in frequency response spectrum analysis in some mode shapes. This study provides an approach to investigate the dynamic frequency response of a ball screw drive system, which provides significant information for better control performance when precise motion control is concerned.

High anisotropic NdFeB submicro/nanoflakes prepared by surfactant-assisted ball milling at low temperature

Science.gov (United States)

An, Xiaoxin; Jin, Kunpeng; Abbas, Nadeem; Fang, Qiuli; Wang, Fang; Du, Juan; Xia, Weixing; Yan, Aru; Liu, J. Ping; Zhang, Jian

2017-11-01

Hard magnetic NdFeB submicro/nanoflakes were successfully prepared by surfactant-assisted ball milling at low temperature (SABMLT) by specially using 2-methyl pentane and trioctylamine (TOA) as solvent and surfactant, respectively. Influences of the amount of TOA and milling temperature on the crystal structure, morphology and magnetic performances of the as-prepared NdFeB powders were investigated systematically. There is significant difference on morphology between the NdFeB powders milled at room and low temperature. The NdFeB powders with flaky morphology could be obtained even with a small amount of TOA by SABMLT, which could not be achieved by surfactant-assisted ball milling at room temperature (SABMRT). The better crystallinity, better grain alignment, higher coercivity, larger saturation magnetization and remanence ratio were achieved in the samples prepared by SABMLT. Furthermore, the final NdFeB powders prepared by SABMLT possessed a lower amount of residual TOA than those prepared by SABMRT. It was demonstrated that SABMLT is a promising way to fabricate rare-earth-transition metal nanoflakes with high anisotropy for permanent magnetic materials. The effective method of preparing NdFeB flakes by lowering temperature will be also useful to fabricate flakes of other functional materials.

Influence of Process Control Agent on Characterization and Structure of Micron Chitosan Powders Prepared by Ball Milling Method

Directory of Open Access Journals (Sweden)

ZHANG Chuan-jie

2016-12-01

Full Text Available With ethyl alcohol or distilled water as process control agent (PCA, micron chitosan powder was prepared by ball milling method. The yield rate, particle size distribution, micro morphology, viscosity average molecular mass, chemical and crystal structures, and thermal properties of these different micron chitosan powders were measured. The results indicate that the yield rate of micron chitosan powders prepared with ethyl alcohol as PCA increases significantly, and improves to 94.7% from 25% while the amount of ethyl alcohol is 0.75mL/g. The particle size distribution of micron chitosan powder prepared with ethyl alcohol as PCA is concentrated, while the D50 and D90 in size are 824nm and 1629nm respectively. Chitosan do not react with ethyl alcohol used as PCA, but the viscosity average molecular mass of prepared micron chitosan powder decreases by 23%, the crystal structures are destroyed slightly, and its thermal stability is slightly weakened.

Surface modification of titanium hydride with epoxy resin via microwave-assisted ball milling

International Nuclear Information System (INIS)

Ning, Rong; Chen, Ding; Zhang, Qianxia; Bian, Zhibing; Dai, Haixiong; Zhang, Chi

2014-01-01

Highlights: • TiH 2 was modified with epoxy resin by microwave-assisted ball milling. • The epoxy ring was opened under the coupling effect of microwave and ball milling. • Microwave-assisted ball milling improved the compatibility of TiH 2 with epoxy. - Abstract: Surface modification of titanium hydride with epoxy resin was carried out via microwave-assisted ball milling and the products were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), thermo-gravimetry (TG) and Fourier transform infrared spectroscopy (FT-IR). A sedimentation test was performed to investigate the compatibility of the modified nano titanium hydride with the epoxy resin. The results show that the epoxy resin molecules were grafted on the surface of nano titanium hydride particles during the microwave-assisted ball milling process, which led to the improvement of compatibility between the nanoparticles and epoxy resin. According to the FT-IR, the grafting site was likely to be located around the epoxy group due to the fact that the epoxy ring was opened. However, compared with microwave-assisted ball milling, the conventional ball milling could not realize the surface modification, indicating that the coupling effect of mechanical force and microwave played a key role during the process

Visual strategies underpinning the development of visual-motor expertise when hitting a ball

NARCIS (Netherlands)

Sarpeshkar, Vishnu; Abernethy, B.; Mann, D.L.

2017-01-01

It is well known that skilled batters in fast-ball sports do not align their gaze with the ball throughout ball-flight, but instead adopt a unique sequence of eye and head movements that contribute toward their skill. However, much of what we know about visual-motor behavior in hitting is based on

Ball tip method for thoracic pedicle screw placement in patients with adolescent idiopathic scoliosis

International Nuclear Information System (INIS)

Watanabe, Kota; Matsumoto, Morio; Iizuka, Shingo

2008-01-01

The purpose of this study was to evaluate the efficacy of ball tip method for thoracic pedicle screw placements in idiopathic scoliosis patients. 24 patients with adolescent idiopathic scoliosis were included in this study. Conventional method was performed in 12 patients. Ball tip method was performed in 12 patients. Accuracy of the pedicle screw placement was evaluated based on the postoperative CT. In the ball tip method, a probe which was consisted of ball tip with flexible shaft was used. After removing of cortical bone at a starting point, the probe was inserted manually or sometimes with gently tapping by hammer. During the maneuver, the probe will gradually progress into cancellous bone in the pedicle, without perforating cortical bone in the pedicle. Following expansion of the hole by a rigid gear shift probe, screw was placed in the pedicle. 65.1% of screws were located within pedicle in the conventional group and 86.5% in the ball tip group. 5.3% of screws were located out of pedicle within 2 mm in the conventional group and 8.2% in the ball tip group. 15.8% of screws were located out of pedicle beyond 2 mm and 1.8% in the ball tip group. The ball tip method enhanced the accuracy of thoracic pedicle screw placements in adolescent idiopathic scoliosis patients. The ball tip method may be effective for accurate pedicle screw placement in patients with adolescent idiopathic scoliosis. (author)

Ball Bearings Equipped for In Situ Lubrication on Demand

Science.gov (United States)

Marchetti, Mario; Jones, William R., Jr.; Pepper, Stephen V.; Jansen, Mark; Predmore, Roamer

2005-01-01

In situ systems that provide fresh lubricants to ball/race contacts on demand have been developed to prolong the operational lives of ball bearings. These systems were originally intended to be incorporated into ball bearings in mechanisms that are required to operate in outer space for years, in conditions in which lubricants tend to deteriorate and/or evaporate. These systems may also be useful for similarly prolonging bearing lifetimes on Earth. Reservoirs have been among the means used previously to resupply lubricants. Lubricant- resupply reservoirs are bulky and add complexity to bearing assemblies. In addition, such a reservoir cannot be turned on or off as needed: it supplies lubricant continuously, often leading to an excess of lubricant in the bearing. A lubricator of the present type includes a porous ring cartridge attached to the inner or the outer ring of a ball bearing (see Figure 1). Oil is stored in the porous cartridge and is released by heating the cartridge: Because the thermal expansion of the oil exceeds that of the cartridge, heating causes the ejection of some oil. A metal film can be deposited on a face of the cartridge to serve as an electrical-resistance heater. The heater can be activated in response to a measured increase in torque that signals depletion of oil from the bearing/race contacts. Because the oil has low surface tension and readily wets the bearing-ring material, it spreads over the bearing ring and eventually reaches the ball/race contacts. The Marangoni effect (a surface-tension gradient associated with a temperature gradient) is utilized to enhance the desired transfer of lubricant to the ball/race contacts during heating. For a test, a ball bearing designed for use at low speed was assembled without lubricant and equipped with a porous-ring lubricator, the resistance heater of which consumed a power of less than 1 W when triggered on by a torque-measuring device. In the test, a load of 20 lb (.89 N) was applied and the

New Q-ball solutions in gauge-mediation, Affleck-Dine baryogenesis and gravitino dark matter

International Nuclear Information System (INIS)

Doddato, Francesca; McDonald, John

2012-01-01

Affleck-Dine (AD) baryogenesis along a d = 6 flat direction in gauge-mediated supersymmetry-breaking (GMSB) models can produce unstable Q-balls which naturally have field strength similar to the messenger scale. In this case a new kind of Q-ball is formed, intermediate between the gravity-mediated and gauge-mediated types. We study in detail these new Q-ball solutions, showing how their properties interpolate between standard gravity-mediated and gauge-mediated Q-balls as the AD field becomes larger than the messenger scale. It is shown that E/Q for the Q-balls can be greater than the nucleon mass but less than the MSSM-LSP mass, leading to Q-ball decay primarily to Standard Model fermions. More significantly, if E/Q is greater than the MSSM-LSP mass, decaying Q-balls can provide a natural source of non-thermal MSSM-LSPs, which can subsequently decay to gravitino dark matter without violating nucleosynthesis constraints. The model therefore provides a minimal scenario for baryogenesis and gravitino dark matter in the gauge-mediated MSSM, requiring no new fields

Durability Tests of Ball Valve Prototype with Flowmeter Operation

Science.gov (United States)

Rogula, J.; Romanik, G.

2018-02-01

The results of the investigation of the prototypical ball valve are presented in this article. The innovation of the tested valve is a ball with a built-in measuring orifice. The valve has been subjected to durability tests. Leakage under three temperatures: ambient, -30°C and +100°C was analyzed. Sealing elements of the valve were tested for roughness and deviation of shape before and after the cycles of operation. Ball valve operation means cycles of open/close. It was planned to perform 1000 cycles at each temperature condition accordingly. Tests of the valve were performed under gas pressure equal to 10 MPa. The research was carried out under the Operational Program "Intelligent Development" (POIR 01.01.01-00-0013 / 15 "Development of devices for measurement of media flow on industrial trunk-lines".

Geometrical origin of chaoticity in the bouncing ball billiard

International Nuclear Information System (INIS)

Mátyás, L.; Barna, I.F.

2011-01-01

Highlights: ► We study the possible separation of neighouring trajectories in the bouncing ball billiard. ► In a certain interval of frequencies semianalitical evaluations are possible. ► One may find a lower bound for the maximal Lyapunov exponent in case of a resonance. - Abstract: We present a study of the chaotic behaviour of the bouncing ball billiard. The work is realised on the purpose of finding at least certain causes of separation of the neighbouring trajectories. Having in view the geometrical construction of the system, we report a clear origin of chaoticity of the bouncing ball billiard. By this we claim that in case when the floor is made of arc of circles – in a certain interval of frequencies – one can give semi-analytical estimates on chaotic behaviour.

Analysis on Sealing Reliability of Bolted Joint Ball Head Component of Satellite Propulsion System

Science.gov (United States)

Guo, Tao; Fan, Yougao; Gao, Feng; Gu, Shixin; Wang, Wei

2018-01-01

Propulsion system is one of the important subsystems of satellite, and its performance directly affects the service life, attitude control and reliability of the satellite. The Paper analyzes the sealing principle of bolted joint ball head component of satellite propulsion system and discuss from the compatibility of hydrazine anhydrous and bolted joint ball head component, influence of ground environment on the sealing performance of bolted joint ball heads, and material failure caused by environment, showing that the sealing reliability of bolted joint ball head component is good and the influence of above three aspects on sealing of bolted joint ball head component can be ignored.

Noninvasive medical management of fungus ball uropathy in a premature infant.

Science.gov (United States)

Alkalay, A L; Srugo, I; Blifeld, C; Komaiko, M S; Pomerance, J J

1991-09-01

Unilateral renal obstruction secondary to fungus balls is described in a premature infant. Noninvasive medical management, which included amphotericin B and 5-flucytosine therapy and forced diuresis, resulted in disappearance of fungus balls and resolution of the obstruction.

Plasma balls in large-N gauge theories and localized black holes

International Nuclear Information System (INIS)

Aharony, Ofer; Minwalla, Shiraz; Wiseman, Toby

2006-01-01

We argue for the existence of plasma balls-metastable, nearly homogeneous lumps of gluon plasma at just above the deconfinement energy density-in a class of large-N confining gauge theories that undergo first-order deconfinement transitions. Plasma balls decay over a time scale of order N 2 by thermally radiating hadrons at the deconfinement temperature. In gauge theories that have a dual description that is well approximated by a theory of gravity in a warped geometry, we propose that plasma balls map to a family of classically stable finite-energy black holes localized in the IR. We present a conjecture for the qualitative nature of large-mass black holes in such backgrounds and numerically construct these black holes in a particular class of warped geometries. These black holes have novel properties; in particular, their temperature approaches a nonzero constant value at large mass. Black holes dual to plasma balls shrink as they decay by Hawking radiation; towards the end of this process, they resemble ten-dimensional Schwarzschild black holes, which we propose are dual to small plasma balls. Our work may find practical applications in the study of the physics of localized black holes from a dual viewpoint

Mechanically Induced Graphite-Nanodiamonds-Phase Transformations During High-Energy Ball Milling

Science.gov (United States)

El-Eskandarany, M. Sherif

2017-05-01

Due to their unusual mechanical, chemical, physical, optical, and biological properties, nearly spherical-like nanodiamonds have received much attention as desirable advanced nanomaterials for use in a wide spectrum of applications. Although, nanodiamonds can be successfully synthesized by several approaches, applications of high temperature and/or high pressure may restrict the real applications of such strategic nanomaterials. Distinct from the current preparation approaches used for nanodiamonds preparation, here we show a new process for preparing ultrafine nanodiamonds (3-5 nm) embedded in a homogeneous amorphous-carbon matrix. Our process started from high-energy ball milling of commercial graphite powders at ambient temperature under normal atmospheric helium gas pressure. The results have demonstrated graphite-single wall carbon nanotubes-amorphous-carbon-nanodiamonds phase transformations carried out through three subsequent stages of ball milling. Based on XRD and RAMAN analyses, the percentage of nanodiamond phase + C60 (crystalline phase) produced by ball milling was approximately 81%, while the amorphous phase amount was 19%. The pressure generated on the powder together the with temperature increase upon the ball-powder-ball collision is responsible for the phase transformations occurring in graphite powders.

RadBall Technology Testing and MCNP Modeling of the Tungsten Collimator.

Science.gov (United States)

Farfán, Eduardo B; Foley, Trevor Q; Coleman, J Rusty; Jannik, G Timothy; Holmes, Christopher J; Oldham, Mark; Adamovics, John; Stanley, Steven J

2010-01-01

The United Kingdom's National Nuclear Laboratory (NNL) has developed a remote, non-electrical, radiation-mapping device known as RadBall(™), which can locate and quantify radioactive hazards within contaminated areas of the nuclear industry. RadBall(™) consists of a colander-like outer shell that houses a radiation-sensitive polymer sphere. The outer shell works to collimate radiation sources and those areas of the polymer sphere that are exposed react, becoming increasingly more opaque, in proportion to the absorbed dose. The polymer sphere is imaged in an optical-CT scanner, which produces a high resolution 3D map of optical attenuation coefficients. Subsequent analysis of the optical attenuation matrix provides information on the spatial distribution of sources in a given area forming a 3D characterization of the area of interest. RadBall(™) has no power requirements and can be positioned in tight or hard-to reach locations. The RadBall(™) technology has been deployed in a number of technology trials in nuclear waste reprocessing plants at Sellafield in the United Kingdom and facilities of the Savannah River National Laboratory (SRNL). This study focuses on the RadBall(™) testing and modeling accomplished at SRNL.

Laser spectroscopy with a cooler ring at the ESR (GSI) and the TSR (MPI Heidelberg)

International Nuclear Information System (INIS)

Kuehl, T.; Borneis, S.; Greten, G.; Marx, D.; Neumann, R.; Schroeder, S.; Grieser, R.; Hoog, I.; Huber, G.; Klaft, I.; Klein, R.; Merz, P.; Balykin, V.; Bock, M.; Ellert, C.; Forck, P.; Grieser, M.; Grimm, R.; Habs, D.; Miesner, H.J.; Petrich, W.; Wanner, B.; Becker, C.; Schwalm, D.; Wolf, A.

1992-01-01

At the TSR cooler ring at Heidelberg, laser studies were carried out using singly charged lithium and beryllium ions. Laser spectroscopy of relativistic lithium ions (υ = 0.04c) yielded signals with a narrow linewidth, suitable for an experimental test of special relativity. A dramatic reduction of the beam temperature, as defined by the longitudinal velocity spread, was achieved via laser cooling in both cases. At the ion energies available at ESR it will become possible to prepare and store bare ions up to U 92+ . Electron cooling was successfully demonstrated for hydrogen-like Bi 82+ ions, where a laser experiment is scheduled to study the ground-state hyperfine splitting. (orig.)

Long-term effects of the “Heidelberg Model of Music Therapy” in patients with chronic tinnitus

Science.gov (United States)

Argstatter, Heike; Grapp, Miriam; Hutter, Elisabeth; Plinkert, Peter; Bolay, Hans Volker

2012-01-01

Objective The “Heidelberg Model of Music Therapy for Chronic Tinnitus” is a manualized short term treatment (nine 50-minutes sessions of individualized therapy on five consecutive days). It has proven to be efficient in reducing tinnitus symptoms in the short run. Now the long-term impact of the treatment after up to 5.4 years should be explored. Materials and methods 206 patients who had attended the neuro-music therapy were addressed in a structured follow-up questionnaire survey. 107 complete questionnaires entered analysis. Follow-up time was 2.65 (SD 1.1) years. Results 76% of the patients achieved a reliable reduction in their tinnitus scores, the overall tinnitus distress as measured by the Mini-TQ diminished from 11.9 (SD = 4.9) to 7.4 (SD = 5.2) points, 87% of the patients were satisfied by the way they were treated during therapy, and 71% of the patients did not undergo any further treatment after. Evaluation of therapeutic elements displays, that only music therapy specific interventions were rated helpful by the patients. Tinnitus related factors (such as tinnitus pitch or loudness, time since onset) did not influence therapy outcome but female gender, positive therapeutic relationship, and higher initial Mini-TQ scores became apparent as factors predicting better chances for greater therapy success. Discussion The “Heidelberg Model of Music Therapy for Chronic Tinnitus” seems to be effective in the long run. The outcome effect size of d’ = 0.89, can be accounted for as “large” effect and falls into the upper range value compared to established treatments. PMID:22993646

Maximizing time from the constraining European Working Time Directive (EWTD): The Heidelberg New Working Time Model.

Science.gov (United States)

Schimmack, Simon; Hinz, Ulf; Wagner, Andreas; Schmidt, Thomas; Strothmann, Hendrik; Büchler, Markus W; Schmitz-Winnenthal, Hubertus

2014-01-01

The introduction of the European Working Time Directive (EWTD) has greatly reduced training hours of surgical residents, which translates into 30% less surgical and clinical experience. Such a dramatic drop in attendance has serious implications such compromised quality of medical care. As the surgical department of the University of Heidelberg, our goal was to establish a model that was compliant with the EWTD while avoiding reduction in quality of patient care and surgical training. We first performed workload analyses and performance statistics for all working areas of our department (operation theater, emergency room, specialized consultations, surgical wards and on-call duties) using personal interviews, time cards, medical documentation software as well as data of the financial- and personnel-controlling sector of our administration. Using that information, we specifically designed an EWTD-compatible work model and implemented it. Surgical wards and operating rooms (ORs) were not compliant with the EWTD. Between 5 pm and 8 pm, three ORs were still operating two-thirds of the time. By creating an extended work shift (7:30 am-7:30 pm), we effectively reduced the workload to less than 49% from 4 pm and 8 am, allowing the combination of an eight-hour working day with a 16-hour on call duty; thus, maximizing surgical resident training and ensuring patient continuity of care while maintaining EDTW guidelines. A precise workload analysis is the key to success. The Heidelberg New Working Time Model provides a legal model, which, by avoiding rotating work shifts, assures quality of patient care and surgical training.

A ball diameter-measuring instrument in a gauge block interferometer

NARCIS (Netherlands)

Kotte, G.J.W.L.; Haitjema, H.; Decker, J.E.; Brown, N.

1998-01-01

An instrument for the measurement of ball diameters in the 0.5-20 mm range in a gauge block interferometer is realized. The measurement principle is that the ball is positioned between an optical flat and a calibrated gauge block. The total length is measured in a gauge block relative to the optical

DIFFERENCES IN TECHNICAL MOVEMENT PRECISION WITH BALL TO NEW AGES SOCCER PLAYERS

Directory of Open Access Journals (Sweden)

Sami Sermaxhaj

2015-05-01

Full Text Available The primary goal of this research is to compare the accuracy of the collision of the ball to players of both age groups U-17 and U-19. The research was conducted on a sample of 100 young soccer players Kosovo divided into two groups: the first group comprised of 50 young players U17 and second group comprised of 50 young soccer players U-19. To assess the precision of the attack on the ball all the players they have subjected technical demonstration testing in four tests: (T-JUGGL, T-PASI, T-KROS, T-SHOOT. Through T-test method are proven differences in favor of players U-19 to U-17 in all tests of precision technical movements with the ball, but statistically significant differences are shown in the collision test at the gateway (T-SHOOT and the test ball juggling (T-JUGGL . The results obtained show us that more experienced players U-19 have a better precision in demonstrating the technical movements with the ball, compared to U-17 players. Assuming that the training process is very important to voice learning, mastering demonstration, acquisition, and precise technical movements with the ball, because the precision peak levels is very significant.

Study of Complexities in Bouncing Ball Dynamical System

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Lal Mohan SAHA

2016-04-01

Full Text Available Evolutionary motions in a bouncing ball system consisting of a ball having a free fall in the Earth’s gravitational field have been studied systematically. Because of nonlinear form of the equations of motion, evolutions show chaos for certain set of parameters for certain initial conditions. Bifurcation diagram has been drawn to study regular and chaotic behavior. Numerical calculations have been performed to calculate Lyapunov exponents, topological entropies and correlation dimension as measures of complexity. Numerical results are shown through interesting graphics.

The Stuttgart-Heidelberg Model of Active Feedback Driven Quality Management: Means for the Optimization of Psychotherapy Provision

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Hans Kordy

2003-01-01

Full Text Available La gestión de la calidad busca la evaluación del tratamiento psicoterapéutico. Un aspecto central se relaciona con el desarrollo de baterías de evaluación y criterios de evaluación adecuados. El modelo Stuttgart-Heidelberg (S-H representa un sistema que proporciona conceptos, instrumentos psicométricos y un programa informático desarrollado para la gestión de la calidad basada en el feedback activo. La información central del modelo Stuttgart-Heidelberg es el resultado individual del tratamiento. El planteamiento es que la psicoterapia puede mejorarse si proporcionamos información sobre los resultados terapéuticos (en especial los negativos, pues los procesos de solución de problemas se estimularán por el feedback recibido. El presente trabajo presenta un inventario de evaluación, la evaluación estandarizada de los resultados y las diversas herramientas de feedback del modelo SH. Un estudio sistemático incluyendo 1715 pacientes de un hospital especializado en trastornos psicosomáticos documenta la validez de este abordaje. Los resultados empíricos refuerzan una estrategia de transparencia acerca de lo que acontece en la práctica clínica – por ejemplo, acerca de los tratamientos administrados, sus resultados y costos. Implicaciones para la posterior optimización de los servicios de salud son discutidos.

A hermeneutical reflection on the resurrection of Jesus Christ in question and answer 45 of the Heidelberg Catechism

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Kobus Labuschagne

2013-10-01

Full Text Available This article is an attempt to elaborate hermeneutically on the different historical contexts, related the one to the other and to the centre point of the resurrection of Jesus Christ, in question and answer 45 of the Heidelberg Catechism. The aim is not only to find the true meaning that the Heidelberg Catechism intends to convey in the mentioned question and answer, but also to explain the underlying hermeneutical thinking as well as to bring to the surface and explain alternative assumptions that ordinary church-going Christians experience as the unusual outcome of an unknown and different kind of approach. Different hermeneutical processes lead to different outcomes of understanding − sometimes worlds apart. Vanuit die sentrale punt van die opstanding van Jesus Christus in vraag en antwoord 45 van die Heidelbergse Kategismus, wil hierdie artikel in ’n hermeneutiese besinning oor die verskillende verbandhoudende historiese kontekste uitbrei. Die doel is nie slegs om die ware betekenis te vind van wat die Heidelbergse Kategismus in genoemde vraag en antwoord poog om weer te gee nie, maar ook om die onderliggende hermeneutiese denke te verduidelik en alternatiewe aannames, wat gewone Christen-kerkgangers as ’n vreemde en verskillende benaderings ervaar, na die oppervlakte te bring en te verduidelik. Verskillende hermeneutiese prosesse lei tot verskillende uitkomste van verstaan – soms wêrelde van mekaar verwyderd.

Patient satisfaction of tooth supported overdentures utilizing ball attachments

OpenAIRE

Nassar, Hossam I.

2016-01-01

Statement of problem: Teeth retained overdenture therapy is an alternative treatment rarely used in cases with few remaining teeth. Purpose: The aim of this study was to evaluate the patient satisfaction associated with teeth retained maxillary and mandibular overdentures utilizing ready made ball attachment. Materials and methods: Thirty patients treated with teeth retained overdenture utilizing ready made ball attachment. Participants completed a series of questionnaires (OHIP-14 ques...

A new ball launching system with controlled flight parameters for catching experiments.

Science.gov (United States)

d'Avella, A; Cesqui, B; Portone, A; Lacquaniti, F

2011-03-30

Systematic investigations of sensorimotor control of interceptive actions in naturalistic conditions, such as catching or hitting a ball moving in three-dimensional space, requires precise control of the projectile flight parameters and of the associated visual stimuli. Such control is challenging when air drag cannot be neglected because the mapping of launch parameters into flight parameters cannot be computed analytically. We designed, calibrated, and experimentally validated an actuated launching apparatus that can control the average spatial position and flight duration of a ball at a given distance from a fixed launch location. The apparatus was constructed by mounting a ball launching machine with adjustable delivery speed on an actuated structure capable of changing the spatial orientation of the launch axis while projecting balls through a hole in a screen hiding the apparatus. The calibration procedure relied on tracking the balls with a motion capture system and on approximating the mapping of launch parameters into flight parameters by means of polynomials functions. Polynomials were also used to estimate the variability of the flight parameters. The coefficients of these polynomials were obtained using the launch and flight parameters of 660 launches with 65 different initial conditions. The relative accuracy and precision of the apparatus were larger than 98% for flight times and larger than 96% for ball heights at a distance of 6m from the screen. Such novel apparatus, by reliably and automatically controlling desired ball flight characteristics without neglecting air drag, allows for a systematic investigation of naturalistic interceptive tasks. Copyright © 2011 Elsevier B.V. All rights reserved.

Kinase inhibition by the Jamaican ball moss, Tillandsia recurvata L.

Science.gov (United States)

Lowe, Henry I C; Watson, Charah T; Badal, Simone; Toyang, Ngeh J; Bryant, Joseph

2012-10-01

This research was undertaken in order to investigate the inhibitory potential of the Jamaican ball moss, Tillandsia recurvata against several kinases. The inhibition of these kinases has emerged as a potential solution to restoring the tight regulation of normal cellular growth, the loss of which leads to cancer cell formation. Kinase inhibition was investigated using competition binding (to the ATP sites) assays, which have been previously established and authenticated. Four hundred and fifty one kinases were tested against the Jamaican ball moss extract and a dose-response was tested on 40 kinases, which were inhibited by more than 35% compared to the control. Out of the 40 kinases, the Jamaican ball moss selectively inhibited 5 (CSNK2A2, MEK5, GAK, FLT and DRAK1) and obtained Kd(50)s were below 20 μg/ml. Since MEK5 and GAK kinases have been associated with aggressive prostate cancer, the inhibitory properties of the ball moss against them, coupled with its previously found bioactivity towards the PC-3 cell line, makes it promising in the arena of drug discovery towards prostate cancer.

Acoustic monitoring of a ball sinking in vibrated granular sediments

Science.gov (United States)

van den Wildenberg, Siet; Léopoldès, Julien; Tourin, Arnaud; Jia, Xiaoping

2017-06-01

We develop an ultrasound probing to investigate the dynamics of a high density ball sinking in 3D opaque dense granular suspensions under horizontal weak vibrations. We show that the motion of the ball in these horizontally vibrated glass bead packings saturated by water is consistent with the frictional rheology. The extracted stress-strain relation evidences an evolution of flow behaviour from frictional creep to inertial regimes. Our main finding is that weak external vibration primarily affects the yield stress and controls the depth of sinking via vibration-induced sliding at the grain contact. Also, we observe that the extracted rheological parameters depend on the size of the probing ball, suggesting thus a non-local rheology.

Reduced graphene oxide synthesis by high energy ball milling

Energy Technology Data Exchange (ETDEWEB)

Mondal, O. [Department of Physics, M.U.C Women' s College, Burdwan 713104 (India); Mitra, S. [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India); Pal, M. [CSIR-Central Glass and Ceramic Research Institute, Kolkata 700032 (India); Datta, A. [University School of Basic and Applied Science (USBAS), Guru Gobind Singh Indraprastha University, New Delhi 110075 (India); Dhara, S. [Surface and Nanoscience Division, Indira Gandhi Centre for Atomic Research, Kalpakkam 603102 (India); Chakravorty, D., E-mail: mlsdc@iacs.res.in [MLS Prof' s Unit, Indian Association for the Cultivation of Science, Kolkata 700032 (India)

2015-07-01

Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. The process of ball milling introduces defects and removes oxygen functional groups, thereby creating the possibility of fine tuning the band gap of all intermediate stages of the structural evolution. A limit of the backbone sp{sup 2} network structure has been found which should be able to accommodate defects, before amorphization sets in. The amorphization of graphene oxide is achieved rather quickly in comparison to that of graphite. From thermogravimetric and differential scanning calorimetric analysis along with Fourier transform infrared (FTIR) and Raman spectroscopic studies, it is found that the number of oxygen-containing groups decreases at a faster rate than that of aromatic double bonds with increasing ball milling time with a maximum limit of 3 h. Several characterization techniques (FTIR, Raman, UV–Visible and X-ray photoelectron spectroscopy) have confirmed that the material synthesized is, indeed, reduced graphene oxide. - Highlights: • Graphene oxide is transformed to reduced graphene oxide by high energy ball milling in inert atmosphere. • Fine tuning the band gap by introducing defects and removing oxygen functional groups. • Introduction of excess defects leads to amorphization. • Photoluminescence has been observed in the UV-blue region.

Effect of process variables on synthesis of MgB2 by a high energy ball mill

Directory of Open Access Journals (Sweden)

Kurama Haldun

2016-01-01

Full Text Available The discovery of superconductivity of MgB2 in 2001, with a critical temperature of 39 K, offered the promise of important large-scale applications at around 20 K. Except than the other featured synthesis methods, mechanical activation performed by high energy ball mills, as bulk form synthesis or as a first step of wire and thin film productions, has considered as an effective alternative production route in recent years. The process of mechanical activation (MA starts with mixing the powders in the right proportion and loading the powder mixture into the mill with the grinding media. The milled powder is then consolidated into a bulk shape and heat-treated to obtain desired microstructure and properties. Thus, the important components of the MA process are the raw materials, mill type and process variables. During the MA process, heavy deformation of particles occure. This is manifested by the presence of a variety of crystal defects such as dislocations, vacancies, stacking faults and increased number of particle boundaries. The presence of this defect structure enhances the diffusivity of solute hence the critical currents and magnetic flux pinning ability of MgB2 are improved. The aim of the present study is to determine the effects of process variables such as ball-to-powder mass ratio, size of balls, milling time, annealing temperature and contribution of process control agent (toluene on the product size, morphology and conversion level of precursor powders to MgB2 after subsequent heat treatment. The morphological analyses of the samples were performed by a high vacuum electron microscope ZEISS SUPRA VP 50. The phase compositions of the samples were performed with an Rigaku-Rint 2200 diffractometer, with nickel filtered Cu Kα radiation and conversion level. The MgB2 phase wt % was calculated by the Rietveld refinement method. The obtained results were discussed according to the process variables to find out their affect on the structure

Fabrication and Study of Micro Monolithic Tungsten Ball Tips for Micro/Nano-CMM Probes

Directory of Open Access Journals (Sweden)

Ruijun Li

2018-03-01

Full Text Available Micro ball tips with high precision, small diameter, and high stiffness stems are required to measure microstructures with high aspect ratio. Existing ball tips cannot meet such demands because of their weak qualities. This study used an arc-discharge melting method to fabricate a micro monolithic tungsten ball tip on a tungsten stylus. The principles of arc discharge and surface tension phenomenon were introduced. The experimental setup was designed and established. Appropriate process parameters, such as impulse voltage, electro discharge time, and discharge gap were determined. Experimental results showed that a ball tip of approximately 60 µm in diameter with less than 0.6 µm roundness error and 0.6 µm center offset could be realized on a 100 µm-diameter tungsten wire. The fabricated micro ball tip was installed on a homemade probe, touched by high-precision gauge blocks in different directions. A repeatability of 41 nm (K = 2 was obtained. Several interesting phenomena in the ball-forming process were also discussed. The proposed method could be used to fabricate a monolithic probe ball tip, which is necessary for measuring microstructures.

A Tsunami Ball Approach to Storm Surge and Inundation: Application to Hurricane Katrina, 2005

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Steven N. Ward

2009-01-01

Full Text Available Most analyses of storm surge and inundation solve equations of continuity and momentum on fixed finite-difference/finite-element meshes. I develop a completely new approach that uses a momentum equation to accelerate bits or balls of water over variable depth topography. The thickness of the water column at any point equals the volume density of balls there. In addition to being more intuitive than traditional methods, the tsunami ball approach has several advantages. (a By tracking water balls of fixed volume, the continuity equation is satisfied automatically and the advection term in the momentum equation becomes unnecessary. (b The procedure is meshless in the finite-difference/finite-element sense. (c Tsunami balls care little if they find themselves in the ocean or inundating land. (d Tsunami ball calculations of storm surge can be done on a laptop computer. I demonstrate and calibrate the method by simulating storm surge and inundation around New Orleans, Louisiana caused by Hurricane Katrina in 2005 and by comparing model predictions with field observations. To illustrate the flexibility of the tsunami ball technique, I run two “What If” hurricane scenarios—Katrina over Savannah, Georgia and Katrina over Cape Cod, Massachusetts.

Solid lubricant mass contact transfer technology usage for vacuum ball bearings longevity increasing

Science.gov (United States)

Arzymatov, B.; Deulin, E.

2016-07-01

A contact mass transfer technological method of solid lubricant deposition on components of vacuum ball bearings is presented. Physics-mathematical model of process contact mass transfer is being considered. The experimental results of ball bearings covered with solid lubricant longevity in vacuum are presented. It is shown that solid lubricant of contact mass transfer method deposition is prospective for ball bearing longevity increasing.

Analisis Perbandingan Experiential Value antara Hong Tang dan Black Ball serta Hubungannya dengan Customer Satisfaction

Directory of Open Access Journals (Sweden)

Annetta Gunawan

2014-11-01

Full Text Available Black Ball and Hong Tang are two pioneers of Taiwanese dessert sellers in Jakarta. Both of them have product offering characteristics that are alike and have the same target market. From the initial observation, the researcher found that even though Black Ball has more outlets than Hong Tang, but Black Ball seems to be less popular than Hong Tang. The consumers’ preferences are varied, there are some consumers prefer Hong Tang, but there are also those who choose Black Ball, because of the food quality, the service provided, and also the experiences they get during the consumption process. Therefore, both Black Ball and Hong Tang have to consider about the experiential value to be offered to their customers, in order to increase their customer satisfaction, so that they can sustainably survive in the midst of challenging competition. The objectives of this research are to examine whether there is any difference of experiential value dimensions and customer satisfaction between Hong Tang and Black Ball and to examine the relationship between experiential value dimensions and customer satisfaction of Hong Tang and Black Ball. The result of this research concludes that there is no difference of all experiential value dimensions and customer satisfaction between Hong Tang and Black Ball and there is a strong and significant relationship between all experiential value dimensions and customer satisfaction of Hong Tang and Black Ball.

Optimum condition determination of Rirang uranium ores grinding using ball mill

International Nuclear Information System (INIS)

Affandi, Kosim; Waluyo, Sugeng; Sarono, Budi; Sujono; Muhammad

2002-01-01

The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm 3

Kicking velocity and effect on match performance when using a smaller, lighter ball in women's football

DEFF Research Database (Denmark)

Andersen, Thomas B.; Krustrup, Peter; Bendiksen, Mads

2016-01-01

The present study evaluated the effect of a smaller, lighter ball on kicking speed and technical-tactical and physical match performance in high-level adult female footballers. In the laboratory test setting, the peak ball velocity was 6% higher with the new ball (NB) than the standard ball (SB...

Ball lightning. What nature is trying to tell the plasma research community

International Nuclear Information System (INIS)

Roth, J.R.

1995-01-01

Ball lightning has been extensively observed in atmospheric air, usually in association with thunderstorms, by untrained observers who were not in a position to make careful observations. These chance sightings have been documented by polling observers, who constitute perhaps 5% of the adult U.S. population. Unfortunately, ball lightning is not accessible to scientific analysis because it cannot be reproduced in the laboratory under controlled conditions. Natural ball lightning has been observed to last longer than 90 s and to have diameters from 1 cm to several meters. The energy density of a few lightning balls has been observed to be as high as 20000 J/cm 3 , well above the limit of chemical energy storage of, for example, TNT at 2000 J/cm 3 . Such observations suggest a plasma-related phenomenon with significant magnetic energy storage. If this is the case, ball lightning should have very interesting implications for fusion research, industrial plasma engineering, and military applications, as well as being of great theoretical and practical interest to the plasma research community. 20 refs., 15 figs., 2 tabs

Formation Mechanism and Characteristics Research of Ball Lightning Based on Vortex Model

International Nuclear Information System (INIS)

Li Zicheng; Yang Guohua

2011-01-01

The strange characteristics of ball lightning are considered as a question hard to explain. In order to solve the problem, in this paper a complete model of plasma vortex is presented for the ball lightning. By ideal MHD equations, through imposing disturbance to plasma column, the possibility of sausage and kink instability of the lightning channel is analyzed from the perspective the minimum potential energy. The conclusion is that the kink instability (m = 1) is most prone to occur. And when instability occurs, because of the difference of the magnetic field in the twisted area, the magnetic pressure makes the trend further and therefore forming the plasma vortex that may eventually turn into ball lightning if the energy of the vortex is large enough. The existence of the vortex makes ball lightning have a short period of time stability. By the proposed model, the ball lightning features that are hard to understand in the past are explained. In this paper, the reason for bead lightning is also explained from the perspective of the sausage instability. (physics of gases, plasmas, and electric discharges)

Simulation of Trajectories of Tar Ball Transport to the Goa Coast

Digital Repository Service at National Institute of Oceanography (India)

Suneel, V.; Vethamony, P.; VinodKumar, K.; Babu, M.T.; Prasad, V.S.R.

Arrival of tar balls to the Goa coast during pre- and southwest monsoon seasons has been a regular phenomenon in the past few years. In one such event, we observed tar ball deposits along the Goa coast during August 2010, April 2011 and May 2011...

Intercepting virtual balls approaching under different gravity conditions: evidence for spatial prediction.

Science.gov (United States)

Russo, Marta; Cesqui, Benedetta; La Scaleia, Barbara; Ceccarelli, Francesca; Maselli, Antonella; Moscatelli, Alessandro; Zago, Myrka; Lacquaniti, Francesco; d'Avella, Andrea

2017-10-01

To accurately time motor responses when intercepting falling balls we rely on an internal model of gravity. However, whether and how such a model is also used to estimate the spatial location of interception is still an open question. Here we addressed this issue by asking 25 participants to intercept balls projected from a fixed location 6 m in front of them and approaching along trajectories with different arrival locations, flight durations, and gravity accelerations (0 g and 1 g ). The trajectories were displayed in an immersive virtual reality system with a wide field of view. Participants intercepted approaching balls with a racket, and they were free to choose the time and place of interception. We found that participants often achieved a better performance with 1 g than 0 g balls. Moreover, the interception points were distributed along the direction of a 1 g path for both 1 g and 0 g balls. In the latter case, interceptions tended to cluster on the upper half of the racket, indicating that participants aimed at a lower position than the actual 0 g path. These results suggest that an internal model of gravity was probably used in predicting the interception locations. However, we found that the difference in performance between 1 g and 0 g balls was modulated by flight duration, the difference being larger for faster balls. In addition, the number of peaks in the hand speed profiles increased with flight duration, suggesting that visual information was used to adjust the motor response, correcting the prediction to some extent. NEW & NOTEWORTHY Here we show that an internal model of gravity plays a key role in predicting where to intercept a fast-moving target. Participants also assumed an accelerated motion when intercepting balls approaching in a virtual environment at constant velocity. We also show that the role of visual information in guiding interceptive movement increases when more time is available. Copyright © 2017 the American Physiological

The dialogue between data and model: passive stability and relaxation behavior in a ball bouncing task

NARCIS (Netherlands)

Dijkstra, T.M.H.; Katsumata, H.; Rugy, A. de; Sternad, D.

2004-01-01

We investigate the skill of rhythmically bouncing a ball on a racket with a focus on the mathematical modeling of the stability of performance. As a first step we derive the deterministic ball bouncing map as a Poincar´e section of a sinusoidally driven bouncing ball. Subsequently, we show the ball

The correct "ball bearings" data.

Science.gov (United States)

Caroni, C

2002-12-01

The famous data on fatigue failure times of ball bearings have been quoted incorrectly from Lieblein and Zelen's original paper. The correct data include censored values, as well as non-fatigue failures that must be handled appropriately. They could be described by a mixture of Weibull distributions, corresponding to different modes of failure.

Evaluation of safety balls and faceguards for prevention of injuries in youth baseball.

Science.gov (United States)

Marshall, Stephen W; Mueller, Frederick O; Kirby, Daniel P; Yang, Jingzhen

2003-02-05

Safety balls and faceguards are widely used in youth baseball, but their effectiveness in reducing injury is unknown. To evaluate the association of the use of faceguards and safety balls and injuries in youth baseball. Ecological study using a national database of compensated insurance claims maintained by Little League Baseball Incorporated, combined with data on the number of participants in Little League and data from a census of protective equipment usage for youth aged 5 to 18 years participating in Little League Baseball in the United States during 1997-1999. Rate of injury and injury rate ratio comparing users with nonusers of protective equipment. A total of 6 744 240 player-seasons of follow-up and 4233 compensated injury claims were available for analysis. The absolute incidence of compensated injury per 100 000 player-seasons was 28.02 (95% confidence interval [CI], 26.76-29.29) for ball-related injury and 2.71 (95% CI, 2.32-3.11) for facial injury. Overall, use of safety balls was associated with a reduced risk of ball-related injury (adjusted rate ratio, 0.77; 95% CI, 0.64-0.93). This reduction was essentially due to 1 type of safety ball, known as the reduced-impact ball (adjusted rate ratio, 0.72; 95% CI, 0.57-0.91). Use of faceguards reduced the risk of facial injury (adjusted rate ratio, 0.65; 95% CI, 0.43-0.98). Metal and plastic guards appeared to be equally effective. Safety balls appeared to be more effective in the minor division (ages 7-12 years) than in the regular division (ages 9-12 years). Reduced-impact balls and faceguards were associated with a reduced risk of injury in youth baseball. These findings support increased usage of these items; however, it should be noted that the absolute incidence of injury in youth baseball is low and that these equipment items do not prevent all injuries.

Between Traditions: Stephen Ball and the Critical Sociology of Education

Science.gov (United States)

Apple, Michael W.

2013-01-01

Stephen Ball's work has deservedly received a good deal of attention. In this article, I detail a number of tasks in which the critical sociologist of education--as a "public intellectual"--should engage. I then place Ball's work within these tasks and evaluate his contributions to them. In the process, I show that one of the…

CVD carbon powders modified by ball milling

Directory of Open Access Journals (Sweden)

Kazmierczak Tomasz

2015-09-01

Full Text Available Carbon powders produced using a plasma assisted chemical vapor deposition (CVD methods are an interesting subject of research. One of the most interesting methods of synthesizing these powders is using radio frequency plasma. This method, originally used in deposition of carbon films containing different sp2/sp3 ratios, also makes possible to produce carbon structures in the form of powder. Results of research related to the mechanical modification of these powders have been presented. The powders were modified using a planetary ball mill with varying parameters, such as milling speed, time, ball/powder mass ratio and additional liquids. Changes in morphology and particle sizes were measured using scanning electron microscopy and dynamic light scattering. Phase composition was analyzed using Raman spectroscopy. The influence of individual parameters on the modification outcome was estimated using statistical method. The research proved that the size of obtained powders is mostly influenced by the milling speed and the amount of balls. Powders tend to form conglomerates sized up to hundreds of micrometers. Additionally, it is possible to obtain nanopowders with the size around 100 nm. Furthermore, application of additional liquid, i.e. water in the process reduces the graphitization of the powder, which takes place during dry milling.

Geometric modeling in the problem of ball bearing accuracy

Science.gov (United States)

Glukhov, V. I.; Pushkarev, V. V.; Khomchenko, V. G.

2017-06-01

The manufacturing quality of ball bearings is an urgent problem for machine-building industry. The aim of the research is to improve the geometric specifications accuracy of bearings based on evidence-based systematic approach and the method of adequate size, location and form deviations modeling of the rings and assembled ball bearings. The present work addressed the problem of bearing geometric specifications identification and the study of these specifications. The deviation from symmetric planar of rings and bearings assembly and mounting width are among these specifications. A systematic approach to geometric specifications values and ball bearings tolerances normalization in coordinate systems will improve the quality of bearings by optimizing and minimizing the number of specifications. The introduction of systematic approach to the international standards on rolling bearings is a guarantee of a significant increase in accuracy of bearings and the quality of products where they are applied.

Validation of single ball rolling contact fatigue machine dynamics

Energy Technology Data Exchange (ETDEWEB)

Allison, Bryan [SKF Aeroengine, Falconer (United States)

2017-01-15

Single ball test machines are a common method for accelerated rolling contact fatigue testing of bearing materials. Historically, it has always been assumed that the force applied by the retaining bars is negligible, without any data to support this claim. In this study, strain gauges were placed on the retaining bars to determine the load experienced by the retaining bars. This value was then compared to the applied load. It was found that a load of approximately 4 N was transferred to the retainer by the test ball during steady state operation, when a 8385 N load was applied to the ball via the rings. A simulation of the system was also created and successfully predicted the expected loads with reasonable accuracy. This information, as well as the technique of strain gauging the retaining bars, may be useful in the development of similar testing machinery.

Identification of sources of tar balls deposited along the Goa coast, India, using fingerprinting techniques

International Nuclear Information System (INIS)

Suneel, V.; Vethamony, P.; Zakaria, M.P.; Naik, B.G.; Prasad, K.V.S.R.

2013-01-01

Highlights: ► This is first fingerprinting study in India on identification of source of tar balls. ► Tar balls were formed from tanker-wash spills and they resemble floating tar ball. ► δ 13 C values of Bombay High crude oil and the present tar balls do not match. ► Compound specific stable carbon isotope analysis confirmed the source of tar balls. ► Source is confirmed as the South East Asian Crude Oil and not the Bombay High crude. -- Abstract: Deposition of tar balls along the coast of Goa, India is a common phenomenon during the southwest monsoon. Representative tar ball samples collected from various beaches of Goa and one Bombay High (BH) crude oil sample were subjected to fingerprint analysis based on diagnostic ratios of n-alkane, biomarkers of pentacyclic tri-terpanes and compound specific stable carbon isotope (δ 13 C) analysis to confirm the source. The results were compared with the published data of Middle East Crude Oil (MECO) and South East Asian Crude Oil (SEACO). The results revealed that the tar balls were from tanker-wash derived spills. The study also confirmed that the source is not the BH, but SEACO. The present study suggests that the biomarkers of alkanes and hopanes coupled with stable carbon isotope analysis act as a powerful tool for tracing the source of tar balls, particularly when the source specific biomarkers fail to distinguish the source

Decay rates of Gaussian-type I-balls and Bose-enhancement effects in 3+1 dimensions

International Nuclear Information System (INIS)

Kawasaki, Masahiro; Yamada, Masaki

2014-01-01

I-balls/oscillons are long-lived spatially localized lumps of a scalar field which may be formed after inflation. In the scalar field theory with monomial potential nearly and shallower than quadratic, which is motivated by chaotic inflationary models and supersymmetric theories, the scalar field configuration of I-balls is approximately Gaussian. If the I-ball interacts with another scalar field, the I-ball eventually decays into radiation. Recently, it was pointed out that the decay rate of I-balls increases exponentially by the effects of Bose enhancement under some conditions and a non-perturbative method to compute the exponential growth rate has been derived. In this paper, we apply the method to the Gaussian-type I-ball in 3+1 dimensions assuming spherical symmetry, and calculate the partial decay rates into partial waves, labelled by the angular momentum of daughter particles. We reveal the conditions that the I-ball decays exponentially, which are found to depend on the mass and angular momentum of daughter particles and also be affected by the quantum uncertainty in the momentum of daughter particles

Crystallization degree change of expanded graphite by milling and annealing

International Nuclear Information System (INIS)

Tang Qunwei; Wu Jihuai; Sun Hui; Fang Shijun

2009-01-01

Expanded graphite was ball milled with a planetary mill in air atmosphere, and subsequently thermal annealed. The samples were characterized by using X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM) and thermal gravimetric analysis (TGA). It was found that in the milling initial stage (less than 12 h), the crystallization degree of the expanded graphite declined gradually, but after milling more than 16 h, a recrystallization of the expanded graphite toke place, and ordered nanoscale expanded graphite was formed gradually. In the annealing initial stage, the non-crystallization of the graphite occurred, but, beyond an annealing time, recrystallizations of the graphite arise. Higher annealing temperature supported the recrystallization. The milled and annealed expanded graphite still preserved the crystalline structure as raw material and hold high thermal stability.

KINEMATICS AND DYNAMICS OF BALLS WHILE BEING POLISHED BETWEEN MISALIGNED DISKS IN DRIVEN SEPARATOR

Directory of Open Access Journals (Sweden)

K. G. Schetnikovich

2007-01-01

Full Text Available The paper contains description of tool design which is used for rough polishing of balls made of brittle materials. This tool consists of top disk, which is fi-eely set on pouring bearing of the separator shaft, and a bottom disk with elastic coating. Theoretical investigations of ball kinematics have permitted to determine an angular velocity of the balls in the machining zone, value and direction oi slipping speed with respect to the tool.it has been determined that even change of the position of bail rotation instantaneous axis relative to the separator is reached at equality of angular velocities of the bottom disk and the separator. When the top disk is freely set slipping speed is equal for all the balls of the machined lot. When the top disk is stationary slipping speed is significantly increasing however its value becomes variable and depends on ball distance to separator rotation axis.The presented equations of ball dynamics in the machining zone have made it possible to detennine a cohesive force with the bottom disk, frictional forces against the top disk and separator. Recommendations on selection of machining modes at initial and final stages of ball polishing are given in the paper.

AM06-25-004 3-D analysis of sports ball flight trajectory by high speed camera

OpenAIRE

溝田, 武人; 小倉, 聡樹; Taketo, MIZOTA; Satoki, OGURA; 福岡工大; 福岡工大:(現)(株)日立建機アルバ; FIT; FIT

2006-01-01

Outdoor experiments of valley ball and soccer ball free fall are conducted at Aso choyo big bridge. High speed camera captured these 3-D trajectories of ball fall process. Image processing of these pictures and Newton's equation of motion were available to clarify unsteady lift C_L and side force C_S. Strouhal number concerning of these sports balls, which are estimated by the unsteady air force, implies that the wavy motion of the balls are a kind of flutter phenomena by wake perturbation an...

Birth ball or heat therapy? A randomized controlled trial to compare the effectiveness of birth ball usage with sacrum-perineal heat therapy in labor pain management.

Science.gov (United States)

Taavoni, Simin; Sheikhan, Fatemeh; Abdolahian, Somayeh; Ghavi, Fatemeh

2016-08-01

Labor pain and its management is a major concern for childbearing women, their families and health care providers. This study aimed to investigate the effects of two non-pharmacological methods such as birth ball and heat therapy on labor pain relief. This randomized control trial was undertaken on 90 primiparous women aged 18-35 years old who were randomly assigned to two intervention (birth ball and heat) and control groups. The pain score was recorded by using Visual Analogue Scale (VAS) before the intervention and every 30 min in three groups until cervical dilatation reached 8 cm. The mean pain severity score in the heat therapy group was less than that of in control group at 60 and 90 min after intervention (p pain scores in the birth ball group after all three investigated times in comparison to control group. Both heat therapy and birth ball can use as inexpensive complementary and low risk treatment for labor pain. Copyright © 2016 Elsevier Ltd. All rights reserved.

Golf Balls, Boomerangs and Asteroids The Impact of Missiles on Society

CERN Document Server

Kaye, Brian H

1996-01-01

Exciting reading for anyone with a curious mind!. 'Walking one day by a golf course in Wisconsin, I was startled to hear a sharp bang as a golf ball narrowly missed my head and hit a tree. My companion cheerfully remarked, 'That could have killed you, you know.' I picked up the innocent looking little white ball and looked at it with new respect.'. Prompted by this perilous experience, Brian Kaye has written a delightful and informative book on the design and behavior of different kinds of missiles from golf balls, arrows, and slingshots to comets and rockets to outer space. You'll learn about

Quartz crystal fabrication facility

Science.gov (United States)

Ney, R. J.

1980-05-01

The report describes the design and operation of a five chamber, interconnected vacuum system, which is capable of cleaning, plating, and sealing precision quartz crystal units in ceramic flatpack enclosures continuously in a high vacuum environment. The production rate design goal was 200 units per eight hour day. A unique nozzle beam gold deposition source was developed to operate for extended periods of time without reloading. The source puts out a narrow beam of gold typically in the order of 2 1/2 deg included cone angle. Maximum deposition rates are in the order of 400 a/min at 5.5 in. 'throw' distance used. Entrance and exit air lock chambers expedite the material throughput, so that the processing chambers are at high vacuum for extended periods of time. A stainless steel conveyor belt, in conjunction with three vacuum manipulators, transport the resonator components to the various work stations. Individual chambers are normally separated from each other by gate valves. The crystal resonators, mounted in flatpack frames but unplated, are loaded into transport trays in a lid-frame-lid sequency for insertion into the system and exit as completed crystal units. The system utilizes molybdenum coated ball bearings at essentially all friction surfaces. The gold sources and plating mask heads are equipped with elevators and gate valves, so that they can be removed from the system for maintenance without exposing the chambers to atmosphere.

Estimating distribution of hidden objects with drones: from tennis balls to manatees.

Directory of Open Access Journals (Sweden)

Julien Martin

Full Text Available Unmanned aerial vehicles (UAV, or drones, have been used widely in military applications, but more recently civilian applications have emerged (e.g., wildlife population monitoring, traffic monitoring, law enforcement, oil and gas pipeline threat detection. UAV can have several advantages over manned aircraft for wildlife surveys, including reduced ecological footprint, increased safety, and the ability to collect high-resolution geo-referenced imagery that can document the presence of species without the use of a human observer. We illustrate how geo-referenced data collected with UAV technology in combination with recently developed statistical models can improve our ability to estimate the distribution of organisms. To demonstrate the efficacy of this methodology, we conducted an experiment in which tennis balls were used as surrogates of organisms to be surveyed. We used a UAV to collect images of an experimental field with a known number of tennis balls, each of which had a certain probability of being hidden. We then applied spatially explicit occupancy models to estimate the number of balls and created precise distribution maps. We conducted three consecutive surveys over the experimental field and estimated the total number of balls to be 328 (95%CI: 312, 348. The true number was 329 balls, but simple counts based on the UAV pictures would have led to a total maximum count of 284. The distribution of the balls in the field followed a simulated environmental gradient. We also were able to accurately estimate the relationship between the gradient and the distribution of balls. Our experiment demonstrates how this technology can be used to create precise distribution maps in which discrete regions of the study area are assigned a probability of presence of an object. Finally, we discuss the applicability and relevance of this experimental study to the case study of Florida manatee distribution at power plants.

Estimating distribution of hidden objects with drones: from tennis balls to manatees.

Science.gov (United States)

Martin, Julien; Edwards, Holly H; Burgess, Matthew A; Percival, H Franklin; Fagan, Daniel E; Gardner, Beth E; Ortega-Ortiz, Joel G; Ifju, Peter G; Evers, Brandon S; Rambo, Thomas J

2012-01-01

Unmanned aerial vehicles (UAV), or drones, have been used widely in military applications, but more recently civilian applications have emerged (e.g., wildlife population monitoring, traffic monitoring, law enforcement, oil and gas pipeline threat detection). UAV can have several advantages over manned aircraft for wildlife surveys, including reduced ecological footprint, increased safety, and the ability to collect high-resolution geo-referenced imagery that can document the presence of species without the use of a human observer. We illustrate how geo-referenced data collected with UAV technology in combination with recently developed statistical models can improve our ability to estimate the distribution of organisms. To demonstrate the efficacy of this methodology, we conducted an experiment in which tennis balls were used as surrogates of organisms to be surveyed. We used a UAV to collect images of an experimental field with a known number of tennis balls, each of which had a certain probability of being hidden. We then applied spatially explicit occupancy models to estimate the number of balls and created precise distribution maps. We conducted three consecutive surveys over the experimental field and estimated the total number of balls to be 328 (95%CI: 312, 348). The true number was 329 balls, but simple counts based on the UAV pictures would have led to a total maximum count of 284. The distribution of the balls in the field followed a simulated environmental gradient. We also were able to accurately estimate the relationship between the gradient and the distribution of balls. Our experiment demonstrates how this technology can be used to create precise distribution maps in which discrete regions of the study area are assigned a probability of presence of an object. Finally, we discuss the applicability and relevance of this experimental study to the case study of Florida manatee distribution at power plants.

Self-dispersed crumpled graphene balls in oil for friction and wear reduction.

Science.gov (United States)

Dou, Xuan; Koltonow, Andrew R; He, Xingliang; Jang, Hee Dong; Wang, Qian; Chung, Yip-Wah; Huang, Jiaxing

2016-02-09

Ultrafine particles are often used as lubricant additives because they are capable of entering tribological contacts to reduce friction and protect surfaces from wear. They tend to be more stable than molecular additives under high thermal and mechanical stresses during rubbing. It is highly desirable for these particles to remain well dispersed in oil without relying on molecular ligands. Borrowing from the analogy that pieces of paper that are crumpled do not readily stick to each other (unlike flat sheets), we expect that ultrafine particles resembling miniaturized crumpled paper balls should self-disperse in oil and could act like nanoscale ball bearings to reduce friction and wear. Here we report the use of crumpled graphene balls as a high-performance additive that can significantly improve the lubrication properties of polyalphaolefin base oil. The tribological performance of crumpled graphene balls is only weakly dependent on their concentration in oil and readily exceeds that of other carbon additives such as graphite, reduced graphene oxide, and carbon black. Notably, polyalphaolefin base oil with only 0.01-0.1 wt % of crumpled graphene balls outperforms a fully formulated commercial lubricant in terms of friction and wear reduction.

Bouncing Ball with a Uniformly Varying Velocity in a Metronome Synchronization Task.

Science.gov (United States)

Huang, Yingyu; Gu, Li; Yang, Junkai; Wu, Xiang

2017-09-21

Sensorimotor synchronization (SMS), a fundamental human ability to coordinate movements with external rhythms, has long been thought to be modality specific. In the canonical metronome synchronization task that requires tapping a finger along with an isochronous sequence, a well-established finding is that synchronization is much more stable to an auditory sequence consisting of auditory tones than to a visual sequence consisting of visual flashes. However, recent studies have shown that periodically moving visual stimuli can substantially improve synchronization compared with visual flashes. In particular, synchronization of a visual bouncing ball that has a uniformly varying velocity was found to be not less stable than synchronization of auditory tones. Here, the current protocol describes the application of the bouncing ball with a uniformly varying velocity in a metronome synchronization task. The usage of the bouncing ball in sequences with different inter-onset intervals (IOI) is included. The representative results illustrate synchronization performance of the bouncing ball, as compared with the performances of auditory tones and visual flashes. Given its comparable synchronization performance to that of auditory tones, the bouncing ball is of particular importance for addressing the current research topic of whether modality-specific mechanisms underlay SMS.

ORTEP-III: Oak Ridge Thermal Ellipsoid Plot Program for crystal structure illustrations

Energy Technology Data Exchange (ETDEWEB)

Burnett, M.N.; Johnson, C.K.

1996-07-01

This report describes a computer program for drawing crystal structure illustrations. Ball-and-stick type illustrations of a quality suitable for publication are produced with either spheres or thermal-motion probability ellipsoids on the atomic sites. The program can also produce stereoscopic pairs of illustrations which aid in the visualization of complex packing arrangements of atoms and thermal motion patterns. Interatomic distances, bond angles, and principal axes of thermal motion are also calculated to aid the structural study.

Ferromagnetic behavior of nanocrystalline Cu–Mn alloy prepared by ball milling

Energy Technology Data Exchange (ETDEWEB)

Mondal, B.N., E-mail: bholanath_mondal@yahoo.co.in [Department of Central Scientific Services, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Sardar, G. [Department of Zoology, Baruipur College, South 24 parganas 743 610 (India); Nath, D.N. [Department of Physical Chemistry, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Chattopadhyay, P.P. [Department of Metallurgy and Materials Engineering, Bengal Engineering and Science University, Shibpur, Howrah 711 103 (India)

2014-12-15

50Cu–50Mn (wt%) alloy was produced by ball milling. The milling was continued up to 30 h followed by isothermal annealing over a four interval of temperature from 350 to 650 °C held for 1 h. Crystallite size, lattice strain, lattice parameter were determined by Rietveld refinement structure analysis of X-ray diffraction data. The amount of dissolved/precipitated Mn (wt%) after ball milling/milling followed by annealing was calculated by quantative phase analysis (QPA). The increase of coercivity could be attributed to the introduction of lattice strain and reduction of crystallite size as a function of milling time. Electron paramagnetic resonance and superconducting quantum interface device analysis indicate that soft ferromagnetic behavior has been achieved by ball milled and annealed Cu–Mn alloy. The maximum coercivity value of Cu–Mn alloy obtained after annealing at 350 °C for 1 h is 277 Oe. - Highlights: • A small amount of Mn has dissolved in Cu after ball milling for 30 h. • Coercivity of the Cu–Mn alloy has increased with an increase in milling time. • Substantial MnO has formed after annealing at 650 °C for 1 h. • The ball milled and annealed alloy have revealed soft ferromagnetic behavior. • The alloy annealed at 350 °C shows the maximum value of coercivity.

Reflections on a Disco Ball

Science.gov (United States)

Ribeiro, Jair Lúcio Prados

2016-01-01

A disco ball is a spherical object covered with small plane mirrors. When light reflects on these mirrors, it is scattered in many directions, producing a novel effect. The mirror globe is usually set to rotate, creating a profusion of moving spots (Fig. 1). In this article, we present a geometrical description of the movement of these spots and…

Dual PD Control Regulation with Nonlinear Compensation for a Ball and Plate System

Directory of Open Access Journals (Sweden)

Sergio Galvan-Colmenares

2014-01-01

Full Text Available The normal proportional derivative (PD control is modified to a new dual form for the regulation of a ball and plate system. First, to analyze this controller, a novel complete nonlinear model of the ball and plate system is obtained. Second, an asymptotic stable dual PD control with a nonlinear compensation is developed. Finally, the experimental results of ball and plate system are provided to verify the effectiveness of the proposed methodology.

Study on the luminous characteristics of a natural ball lightning

Science.gov (United States)

Wang, Hao; Yuan, Ping; Cen, Jianyong; Liu, Guorong

2018-02-01

According to the optical images of the whole process of a natural ball lightning recorded by two slit-less spectrographs in the Qinghai plateau of China, the simulated observation experiment on the luminous intensity of the spherical light source was carried out. The luminous intensity and the optical power of the natural ball lightning in the wavelength range of 400-690 nm were estimated based on the experimental data and the Lambert-Beer Law. The results show that the maximum luminous intensity was about 1.24 × 105 cd in the initial stage of the natural ball lightning, and the maximum luminous intensity and the maximum optical power in most time of its life were about 5.9 × 104 cd and 4.2 × 103 W, respectively.

Preparing to understand and use science in the real world: interdisciplinary study concentrations at the Technical University of Darmstadt.

Science.gov (United States)

Liebert, Wolfgang J

2013-12-01

In order to raise awareness of the ambiguous nature of scientific-technological progress, and of the challenging problems it raises, problems which are not easily addressed by courses in a single discipline and cannot be projected onto disciplinary curricula, Technical University of Darmstadt has established three interdisciplinary study concentrations: "Technology and International Development", "Environmental Sciences", and "Sustainable Shaping of Technology and Science". These three programmes seek to overcome the limitations of strictly disciplinary research and teaching by developing an integrated, problem-oriented approach. For example, one course considers fundamental nuclear dilemmas and uses role-playing techniques to address a controversy in the area of nuclear security. At the same time, incorporating interdisciplinary teaching into a university that is organized around mono- or multi-disciplinary faculties also poses a number of challenges. Recognition in disciplinary curricula, and appropriate organizational support and funding are examples of those challenges. It is expected that science and engineering students, empowered by such interdisciplinary study programmes, will be better prepared to act responsibly with regard to scientific and technological challenges.

An experiment on a ball-lightning model

International Nuclear Information System (INIS)

Ignatovich, F.V.; Ignatovich, V.K.

2010-01-01

We discuss total internal reflection (TIR) from an interface between glass and gainy gaseous media and propose an experiment for strong light amplification related to investigation of a ball-lightning model

A controlled study on batted ball speed and available pitcher reaction time in slowpitch softball

Science.gov (United States)

McDowell, M; Ciocco, M

2005-01-01

Objectives: To investigate safety risks in slowpitch softball by conducting laboratory and experimental studies on the performance of high tech softball bats with polyurethane softballs. To compare the results with the recommended safety standards. Methods: ASTM standard compression testing of seven softball models was conducted. Using these seven softball models, bat/ball impact testing was performed using seven adult male softball players and six high tech softball bat models to determine mean batted ball speeds. Over 500 bat/ball impact measurements were recorded and analysed. Available pitcher reaction time was calculated from the mean batted ball speed measurements. Results: According to the United States Specialty Sports Association and the Amateur Softball Association, the maximum initial batted ball speed should be 137.2 km/h, which corresponds to a minimum pitcher reaction time of 0.420 second. These experiments produced mean batted ball speeds of 134.0–159.7 km/h, which correspond to available pitcher reaction times of 0.409–0.361 second. Conclusion: The use of high tech softball bats with polyurethane softballs can result in batted ball speeds that exceed the recommended safety limits, which correspond to decreased available pitcher reaction times. PMID:15793092

Crystallography beyond periodic Crystal perfection

International Nuclear Information System (INIS)

Estevez-Rams, E.

2008-01-01

Full text: The discovery of the quasi-crystals [D. Schechtman et. Al., Phys.] Rev. Lett. [53, 1951-1953 (1984)] made very narrow definition of the crystalline state based on the periodicity of a local arrangement of atoms. Since the definition of this State has been a matter of much controversy [G.R. Desiraju, Nature 423, 485 (2003); S. van Smaalen, IUCR Aperiodic Commission Reports. August 7, 2002; International Union of Crystallography. Report of the Executive Committee for 1991; ACTA Cryst. A48, 922-946 (1992)]. We will make a presentation of the current time of the crystallography in this regard from the conceptual point of view. We show the use of the formalism of algorithmic complexity or Kolmogorov [M. Li and P. Vitanyi, An Introduction to Kolmogorov Complexity and Its Applications (Springer Verlag, Heidelberg, 1993), W.H. Zurek, Phys.] Rev. 40, 4731 (1989); Nature 341, 119-124 (1989)] provides a different perspective on the nature of the Crystallographic order. Infinite crystals can be considered solid with zero algorithmic complexities by atom. Show statistical analysis of inorganic compounds [J.L.C. Daams et al., Atlas of Crystal Structure Types for Intermetallic Phases (ASM International, Ohio, 1991), Fachinformationszentrum/NIST Inorganic Crystal Structure Database, Karlsruhe (2003) icsd.fkf.mpg.de] demonstrating that the minimization of complexity is a trend in the crystalline arrangement. We will then compare the degree of disorder of some typical solids according to their algorithmic complexity. Finally, space diffraction will be studied from this same perspective and will be discussed that zero algorithmic complexities by point in space of diffraction does not necessarily imply the same thing for the Atomic arrangement. The discrete portion of the diffraction pattern is a fingerprint of the underlying order but not the actual existence of long-range order. Experimental results will be showcased [E. Estévez-Rams et al., Physical Review B, 63 (2001

Heidelberg physicists report. Vol. 2. Reviews of research in physics and astronomy. Fundamental contributions to the physics of the atomic nuclei and the star atmospheres

International Nuclear Information System (INIS)

Appenzeller, Immo; Dubbers, Dirk; Siebig, Hans-Georg; Winnacker, Albrecht

2018-01-01

The following topics are dealt with: 50 years theoretical astrophysics, nuclear physics after the discovery of the shell model, from the small van de Graaf to the large HERA, from ''chamber physics'' to big research, reminiscences on physical research in Heidelberg. (HSI)

Study of the dynamic properties and effects of temperature using a spring model for the bouncing ball

International Nuclear Information System (INIS)

Wadhwa, Ajay

2013-01-01

We studied the motion of a bouncing ball by representing it through an equivalent mass–spring system executing damped harmonic oscillations. We represented the elasticity of the system through the spring constant ‘k’ and the viscous damping effect, causing loss of energy, through damping constant ‘c’. By including these two factors we formed a differential equation for the equivalent mass–spring system of the bouncing ball. This equation was then solved to study the elastic and dynamic properties of its motion by expressing them in terms of experimentally measurable physical quantities such as contact time, coefficient of restitution, etc. We used our analysis for different types of ball material: rubber (lawn-tennis ball, super ball, soccer ball and squash ball) and plastic (table-tennis ball) at room temperature. Since the effect of temperature on the bounce of a squash ball is significant, we studied the temperature dependence of its elastic properties. The experiments were performed using audio and surface-temperature sensors interfaced with a computer through a USB port. The work presented here is suitable for undergraduate laboratories. It particularly emphasizes the use of computer interfacing for conducting conventional physics experiments. (paper)

Radar speed gun true velocity measurements of sports-balls in flight: application to tennis

International Nuclear Information System (INIS)

Robinson, Garry; Robinson, Ian

2016-01-01

Spectators of ball-games often seem to be fascinated by the speed of delivery of the ball. They appear to be less interested in or even oblivious to the mechanism and accuracy of the measurement or where in the flight path of the ball the measurement is actually made. Radar speed guns using the Doppler effect are often employed for such speed measurements. It is well known that such guns virtually always measure the line-of-sight or radial velocity of the ball and as such will return a reading less than or equal to the true speed of the ball. In this paper, using only basic physics principles we investigate such measurements, in particular those associated with the service stroke in tennis. For the service trajectories employed here, a single radar gun located in line with the centre-line of the court in fact under-estimates the speed of a wide serve by about 3.4% at the point of delivery, and by about 14.3% on impact with the court. However, we demonstrate that both the magnitude and direction of the true velocity of the ball throughout its entire flight path may be obtained, at least in principle, by the use of four suitably placed radar speed guns. These four guns must be able to measure the ‘range’ to the ball, enabling its position in flight to be determined, and three of them must be able to measure the radial velocity of the ball. Restrictions on the locations of the speed guns are discussed. Such restrictions are quite liberal, although there are certain configurations of the radar gun positions which cannot be used. Importantly, with the one proviso that no speed gun can be directly in the path of the ball (not only for the obvious reasons), we find that if the speed of the ball can be determined for one point in the trajectory, it can also be determined for all points. The accuracy of the range and radial velocity measurements required to give meaningful results for the true velocity are also briefly discussed. It is found that the accuracy required

Comparison of exit time moment spectra for extrinsic metric balls

DEFF Research Database (Denmark)

Hurtado, Ana; Markvorsen, Steen; Palmer, Vicente

2012-01-01

We prove explicit upper and lower bounds for the $L^1$-moment spectra for the Brownian motion exit time from extrinsic metric balls of submanifolds $P^m$ in ambient Riemannian spaces $N^n$. We assume that $P$ and $N$ both have controlled radial curvatures (mean curvature and sectional curvature...... obtain new intrinsic comparison results for the exit time spectra for metric balls in the ambient manifolds $N^n$ themselves....

Review of the dynamic behaviour of sports balls during normal and oblique impacts

Science.gov (United States)

Haron, Muhammad Adli; Jailani, Azrol; Abdullah, Nik Ahmad Faris Nik; Ismail, Rafis Suizwan; Rahim, Shayfull Zamree Abd; Ghazali, Mohd Fathullah

2017-09-01

In this paper are review of impact experiment to study the dynamic behaviour of sports ball during oblique and normal impacts. In previous studies, the investigation was done on the dynamic behaviour of a sports ball during oblique and normal impacts from experimental, numerical, and theoretical viewpoints. The experimental results are analysed and compared with the theories, in order to understand the dynamics behaviours based on the phenomenological occurrence. Throughout the experimental studies previously, there are results of dynamics behaviours examined by many researchers such as the coefficient of restitution, tangential coefficient, local deformation, dynamic impact force, contact time, angle of impact (inbound and rebound), spin rate of the ball, ball stiffness and damping coefficient which dependable of the initial or impact velocity.

On the dynamics of ball bearings

NARCIS (Netherlands)

Wensing, J.A.

1998-01-01

This investigation on the dynamic behaviour of ball bearings was motivated by the demand for silent bearings in noise-sensitive applications, especially in the household appliance and automotive industry. The present investigations are intended to provide a clear understanding of the role of the

Biomechanical predictors of ball velocity during punt kicking in elite rugby league kickers

OpenAIRE

Sinclair, Jonathan Kenneth; Taylor, Paul John; Atkins, Stephen; Hobbs, Sarah Jane

2016-01-01

Punt kicking is integral to the attacking and defensive elements of rugby league and the ability to kick the ball with high\\ud velocity is desirable. This study aimed to identify important technical aspects of kicking linked to the generation of ball\\ud velocity. Maximal punt kicks were obtained from six elite rugby league kickers using a 10-camera motion capture system.\\ud Three-dimensional kinematics of the lower extremities was obtained. Regression analysis with ball velocity as criterion\\...

Preparation of tungsten-iron carbide by ball milling

International Nuclear Information System (INIS)

Wang, G.M.; Campbell, S.J.; Calka, A.; Kaczmarek, W.A.

1996-01-01

Several sets of elemental powder mixtures of Fe-W-C (W 46 Fe 46 C 8 , W 60 Fe 20 C 20 and W 34 Fe 33 C 33 ) were ball milled using Uni-Ball mill for periods of up to 550 h in vacuum with a ball - to - powder ratio of about 35:1. Depending on the milling time, the main component of the as-milled materials was found to be solid solutions of Fe-W-C or Fe-C. Ternary phase W 3 Fe 3 C was obtained on annealing the as-milled materials at about 700 deg C. This product was then found to transfer to (FeW) 6 C on heat treatment at about 800 deg C. The resultant products of the annealing processes were found to depend not only on the annealing temperature, but also the starting composition, especially the initial carbon concentration. Detailed information on the structural and phase evolution during thermal treatment as measured using x-ray diffraction, Moessbauer spectroscopy and thermal analysis is presented. Special interest is focused on the competition for formation in this system between the Fe-C, W-Fe and W-C phases

Dark matter gravitinos and baryons via Q-ball decay in the gauge-mediated MSSM

International Nuclear Information System (INIS)

Doddato, Francesca; McDonald, John

2013-01-01

We show that late Q-ball decay in the MSSM with gauge-mediated SUSY breaking can provide a natural source of non-thermal NLSPs which subsequently decay to gravitino dark matter without violating nucleosynthesis constraints. To show this, we perform a global analysis of Q-ball formation and decay in Affleck-Dine baryogenesis for a d = 6 (u c d c d c ) 2 flat direction of the gauge-mediated MSSM. A general phenomenological potential for the flat-direction is studied and the Q-ball decay properties are obtained as a function of its parameters. The corresponding gravitino mass necessary to account for dark matter is then determined for the case of stau NLSPs. The decay temperature depends on the charge of the Q-balls, which is determined by the fragmentation of the AD condensate. Different fragmentation scenarios are considered, and the final non-thermal NLSP density from Q-ball decay and NLSP annihilation is determined. Particular care is taken to establish that NLSPs from Q-ball decay become homogeneous and non-relativistic prior to annihilation. The gravitino mass necessary for dark matter is naturally consistent with the theoretical gravitino mass in the gauge-mediation model

Effect of tea polyphenols on microbiological and biochemical quality of Collichthys fish ball.

Science.gov (United States)

Yi, Shumin; Li, Jianrong; Zhu, Junli; Lin, Yi; Fu, Linglin; Chen, Wei; Li, Xuepeng

2011-07-01

Tea polyphenols (TP), as the most active constituents of tea, are considered natural food additives. This study examined the preservative properties of TP for Collichthys fish ball in well storage. Vacuum-packed Collichthys fish balls were treated with 0, 0.1, 0.15, 0.20, 0.25, and 0.30 g kg(-1) TP and stored at 0 °C for 17 days. Microbiological results were obtained using a biochemical test, API system kit, and 16S rDNA sequence analysis. Results confirmed that the dominant bacteria in Collichthys fish balls are the genera Serratia and Pseudomonas. Total viable counts dropped two orders of magnitude in Collichthys fish balls with 0.25 g kg(-1) TP compared with the control. The advantages of total volatile basic nitrogen value, 2-thiobarbituric acid value and texture value were clearly observed, whereas pH and whiteness value exhibited no significant decrease for the group treated with 0.25 g kg(-1) TP. More than 0.25 g kg(-1) TP added could retain excellent fish ball characteristics in terms of sensory assessment after 17 days. The shelf life of Collichthys fish balls supplemented with tea polyphenols can be prolonged for an additional 6 days in good condition at 0 °C storage. Copyright © 2011 Society of Chemical Industry.

Phase transition of Ni-Mn-Ga alloy powders prepared by vibration ball milling

International Nuclear Information System (INIS)

Tian, B.; Chen, F.; Tong, Y.X.; Li, L.; Zheng, Y.F.; Liu, Y.; Li, Q.Z.

2011-01-01

Research highlights: → The vibration ball milling with a high milling energy introduces the atomic disorder and large lattice distortion in the alloy during milling and makes the formation of disordered fcc structure phase in the alloy. → The transition temperature and activation energy for disordered fcc → disordered bcc are ∼320 o C and 209 ± 8 kJ/mol, respectively. → The alloy powders annealed at 800 o C for 1 h show a one-stage martensitic transformation with quite lower latent heat compared to the bulk alloy. - Abstract: This study investigated the phase transformation of the flaky shaped Ni-Mn-Ga powder particles with thickness around 1 μm prepared by vibration ball milling and post-annealing. The SEM, XRD, DSC and ac magnetic susceptibility measurement techniques were used to characterize the Ni-Mn-Ga powders. The structural transition of Heusler → disordered fcc occurred in the powders prepared by vibration ball milling (high milling energy) for 4 h, which was different from the structural transition of Heusler → disordered fct of the powders fabricated by planetary ball milling (low milling energy) for 4 h. The two different structures after ball milling should be due to the larger lattice distortion occurred in the vibration ball milling process than in the planetary ball milling process. The structural transition of disordered fcc → disordered bcc took place at ∼320 o C during heating the as-milled Ni-Mn-Ga powders, which was attributed to the elimination of lattice distortion caused by ball milling. The activation energy for this transition was 209 ± 8 kJ/mol. The Ni-Mn-Ga powder annealed at 800 o C mainly contained Heusler austenite phase at room temperature and showed a low volume of martensitic transformation upon cooling. The inhibition of martensitic transformation might be attributed to the reduction of grain size in the annealed Ni-Mn-Ga particles.

Ball Bearing Stiffnesses- A New Approach Offering Analytical Expressions

Science.gov (United States)

Guay, Pascal; Frikha, Ahmed

2015-09-01

Space mechanisms use preloaded ball bearings in order to withstand the severe vibrations during launch.The launch strength requires the calculation of the bearing stiffness, but this calculation is complex. Nowadays, there is no analytical expression that gives the stiffness of a bearing. Stiffness is computed using an iterative algorithm such as Newton-Raphson, to solve the nonlinear system of equations.This paper aims at offering a simplified analytical approach, based on the assumption that the contact angle is constant. This approach gives analytical formulas of the stiffness of preloaded ball bearing.

Linearly convergent stochastic heavy ball method for minimizing generalization error

KAUST Repository

Loizou, Nicolas

2017-10-30

In this work we establish the first linear convergence result for the stochastic heavy ball method. The method performs SGD steps with a fixed stepsize, amended by a heavy ball momentum term. In the analysis, we focus on minimizing the expected loss and not on finite-sum minimization, which is typically a much harder problem. While in the analysis we constrain ourselves to quadratic loss, the overall objective is not necessarily strongly convex.

A study on the noise characteristics of polymer ball bearings under various lubrication conditions

Science.gov (United States)

Dinç, S. K.; Temiz, V.; Kamburoǧlu, E.

2013-12-01

Polymer bearings are generally praised by the manufacturers for running silently. However such statements never go beyond qualitative assumptions. Therefore, studying polymer ball bearing noise would have been meaningful solely on the perspective of silent running machinery. On the other hand, the service life of a polymer ball bearing is unpredictable and there's no preventive maintenance practice that provides data regarding the condition of a polymer ball bearing. In this study, we assume that an investigation of their noise characteristics could also reveal clues concerning their performances. The main objective of this study is to determine the noise characteristics of polymer ball bearings lubricated with different lubricant greases of varying viscosity grades through experimental means. Sound pressure level measurements of SKF brand polymer bearings with polypropylene rings, polypropylene cage and glass balls were made with a 1/2 inch microphone in 1/3-octave bands, at frequencies up to 12.5 kHz, under various radial loads and rotational speeds. The bearings were mounted on a shaft driven by an AC motor with stepless speed control, adjustable between 0 - 1400 rpm. The ball bearings were running inside an acoustic chamber designed for the insulation of environmental noise and the noise of the motor at target frequencies. The resulting sound pressure level spectra were evaluated and the effects of the lubrication conditions on the noise of the ball bearing and possible diagnostic insight that could be gained through studying bearing noise characteristics were discussed.

Keep your eyes on the ball: smooth pursuit eye movements enhance prediction of visual motion.

Science.gov (United States)

Spering, Miriam; Schütz, Alexander C; Braun, Doris I; Gegenfurtner, Karl R

2011-04-01

Success of motor behavior often depends on the ability to predict the path of moving objects. Here we asked whether tracking a visual object with smooth pursuit eye movements helps to predict its motion direction. We developed a paradigm, "eye soccer," in which observers had to either track or fixate a visual target (ball) and judge whether it would have hit or missed a stationary vertical line segment (goal). Ball and goal were presented briefly for 100-500 ms and disappeared from the screen together before the perceptual judgment was prompted. In pursuit conditions, the ball moved towards the goal; in fixation conditions, the goal moved towards the stationary ball, resulting in similar retinal stimulation during pursuit and fixation. We also tested the condition in which the goal was fixated and the ball moved. Motion direction prediction was significantly better in pursuit than in fixation trials, regardless of whether ball or goal served as fixation target. In both fixation and pursuit trials, prediction performance was better when eye movements were accurate. Performance also increased with shorter ball-goal distance and longer presentation duration. A longer trajectory did not affect performance. During pursuit, an efference copy signal might provide additional motion information, leading to the advantage in motion prediction.

Processing of magnetically anisotropic MnBi particles by surfactant assisted ball milling

Energy Technology Data Exchange (ETDEWEB)

Kanari, K. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Sarafidis, C., E-mail: hsara@physics.auth.gr [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece); Gjoka, M.; Niarchos, D. [INN, NCSR Demokritos, Athens 15310 (Greece); Kalogirou, O. [Department of Physics, Aristotle University of Thessaloniki, 54124 Thessaloniki (Greece)

2017-03-15

MnBi particles are obtained from bulk MnBi using mechanochemical processing. The structure and magnetic properties of the MnBi particles are investigated by means of X-ray diffraction analysis, scanning electron microscopy and magnetometry. Surfactant assisted high energy ball milling results to the samples’ degradation even after one hour of milling. In the case of surfactant assisted low energy ball milling the increase of ball milling duration decreases the average particle size while the particles seem to be more separated. The saturation magnetization (M{sub s}) was found to decrease for large milling times beginning from 61 Am{sup 2}/kg, while the coercivity (μ{sub 0}H{sub c}) increases with the increase of ball milling duration up to 35 min where it reaches 1.62 T and thereafter it decreases. - Highlights: • Effect of surfactants in processing of MnBi. • Magnetization degradation due to air storage and due to processing. • Coercivity of 1.6 T in epoxy resin oriented material.

An asymmetric resonant coupling wireless power transmission link for Micro-Ball Endoscopy.

Science.gov (United States)

Sun, Tianjia; Xie, Xiang; Li, Guolin; Gu, Yingke; Deng, Yangdong; Wang, Ziqiang; Wang, Zhihua

2010-01-01

This paper investigates the design and optimization of a wireless power transmission link targeting Micro-Ball Endoscopy applications. A novel asymmetric resonant coupling structure is proposed to deliver power to an endoscopic Micro-Ball system for image read-out after it is excreted. Such a technology enables many key medical applications with stringent requirements for small system volume and high power delivery efficiency. A prototyping power transmission sub-system of the Micro-Ball system was implemented. It consists of primary coil, middle resonant coil, and cube-like full-direction secondary receiving coils. Our experimental results proved that 200mW of power can be successfully delivered. Such a wireless power transmission capability could satisfy the requirements of the Micro-Ball based endoscopy application. The transmission efficiency is in the range of 41% (worst working condition) to 53% (best working condition). Comparing to conventional structures, Asymmetric Resonant Coupling Structure improves power efficiency by 13%.

Ball lightning: What nature is trying to tell the plasma research community

International Nuclear Information System (INIS)

Roth, J.R.

1993-01-01

Ball lightning has been frequently observed and chance observations of it have been extensively documented by polling observers, who constitute perhaps 5% of the adult US population. Ball lightning is not accessible to scientific analysis at the present time, because it cannot be reproduced in the laboratory under controlled conditions. It has been extensively observed in atmospheric air, usually in association with thunderstorms, and by untrained observers who were not disposed to make careful observations. Ball lightning has been observed to last as long a 90 seconds, and to have diameters from one centimeter to several meters. The energy density of a few lightning balls has been observed to be as high as 20,000 joules per cubic centimeter, well above the limit of chemical energy storage of, for example, TNT at 2,000 per cubic centimeter. This suggests magnetic energy storage in a plasma-related phenomenon, which should be of great theoretical and practical interest to the plasma research community

Using Balls of Different Sports To Model the Variation of Atomic Sizes

Science.gov (United States)

Pinto, Gabriel

1998-06-01

In this article, an analogy is described about the order of magnitude of the variation of atomic sizes that can be used for discussion in introductory chemistry classes. The order of magnitude of this variation, involving microscopic magnitudes, is difficult for students to imagine. For the most part, the students are very familiar with the world of sports. In any case for example, the teacher can make use of the wide, informative coverage given to the olympic games or similar events, where different sports are televised in a few days. The radii of official balls for seven well-known sports are given, and students must assign an atom to each ball by using tabulated single-bond, covalent radii and by assigning the smallest ball (i.e., corresponding to ping-pong) to the smallest atom (i.e., hydrogen). The balls can also be used to show how the ionic radii change upon ionization.

A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor.

Science.gov (United States)

Zhang, Huayu; Xie, Fengqin; Cao, Maoyong; Zhong, Mingming

2017-07-01

To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA) sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor), magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

A real-time surface inspection system for precision steel balls based on machine vision

Science.gov (United States)

Chen, Yi-Ji; Tsai, Jhy-Cherng; Hsu, Ya-Chen

2016-07-01

Precision steel balls are one of the most fundament components for motion and power transmission parts and they are widely used in industrial machinery and the automotive industry. As precision balls are crucial for the quality of these products, there is an urgent need to develop a fast and robust system for inspecting defects of precision steel balls. In this paper, a real-time system for inspecting surface defects of precision steel balls is developed based on machine vision. The developed system integrates a dual-lighting system, an unfolding mechanism and inspection algorithms for real-time signal processing and defect detection. The developed system is tested under feeding speeds of 4 pcs s-1 with a detection rate of 99.94% and an error rate of 0.10%. The minimum detectable surface flaw area is 0.01 mm2, which meets the requirement for inspecting ISO grade 100 precision steel balls.

The small displacement elastic solution to the ball-on-ring testing method

DEFF Research Database (Denmark)

Frandsen, Henrik Lund

2012-01-01

The ball-on-ring experiment is used for testing of the biaxial strength of ceramics. In this work the solution for the stress distribution and displacements of the disc specimen in the ball-on-ring experiment are determined on closed form. The solution comprises the displacement field and its...

Survival of Phytophthora ramorum in Rhododendron root balls and in rootless substrates

Science.gov (United States)

A. Vercauteren; M. Riedel; M. Maes; S. Werres; K. Heungens

2013-01-01

This study assesses the survival of Phytophthora ramorum in the root ball of Rhododendron container plants as well as in different rootless forest substrates and a horticultural potting medium. Following inoculation of the root balls, the aboveground plant parts stayed symptomless, whilst the pathogen could be recovered with a...

Evaluation of possible head injuries ensuing a cricket ball impact.

Science.gov (United States)

Mohotti, Damith; Fernando, P L N; Zaghloul, Amir

2018-05-01

The aim of this research is to study the behaviour of a human head during the event of an impact of a cricket ball. While many recent incidents were reported in relation to head injuries caused by the impact of cricket balls, there is no clear information available in the published literature about the possible threat levels and the protection level of the current protective equipment. This research investigates the effects of an impact of a cricket ball on a human head and the level of protection offered by the existing standard cricket helmet. An experimental program was carried out to measure the localised pressure caused by the impact of standard cricket balls. The balls were directed at a speed of 110 km/h on a 3D printed head model, with and without a standard cricket helmet. Numerical simulations were carried out using advanced finite element package LS-DYNA to validate the experimental results. The experimental and numerical results showed approximately a 60% reduction in the pressure on the head model when the helmet was used. Both frontal and side impact resulted in head acceleration values in the range of 225-250 g at a ball speed of 110 km/h. There was a 36% reduction observed in the peak acceleration of the brain when wearing a helmet. Furthermore, numerical simulations showed a 67% reduction in the force on the skull and a 95% reduction in the skull internal energy when introducing the helmet. (1) Upon impact, high localised pressure could cause concussion for a player without helmet. (2) When a helmet was used, the acceleration of the brain observed in the numerical results was at non-critical levels according to existing standards. (3) A significant increase in the threat levels was observed for a player without helmet, based on force, pressure, acceleration and energy criteria, which resulted in recommending the compulsory use of the cricket helmet. (4) Numerical results showed a good correlation with experimental results and hence, the

Caesium releases under the form of silicon micro-balls during the Fukushima-Daiichi accident. Information note

International Nuclear Information System (INIS)

2016-01-01

After having outlined that the most part (89 per cent) of radioactive cesium released in the atmosphere during the Fukushima accident was made under the form of silicon micro-balls which were more irradiating than other aerosols marked by cesium radioactive isotopes, this note first discusses whether these silicon micro-balls containing radioactive cesium were resulting from a specific phase of atmospheric release. It discusses the nature of these micro-balls, and discusses whether it is possible to quantitatively assess the contribution of these micro-balls to global releases and deposits. It discusses how these micro-balls could have formed, whether their formation can be associated with a specific phase of reactor degradation or with the degradation of a specific reactor. It discusses whether a specific behaviour of these micro-balls can be expected in the environment, and their possible impacts on radiological consequences

A Case of Lung Lesions Induced by a soccer Ball

Directory of Open Access Journals (Sweden)

Masaaki Takemoto

2013-01-01

Full Text Available An 18-year-old youth soccer forward received a direct hit from a kicked soccer ball on the anterior right chest when the goal keeper kicked the ball from a distance of 1 meter. Immediately following the hit, the subject experienced dypnea, chest pain and had a cough, with several milliliters of hemoptysis. His symptoms subsided after 20 minutes of rest. However, he still felt mild discomfort and was taken to our department for evaluation. On examination, all vital signs were normal. A computed tomography scan of the chest was obtained, and revealed a small area of opacification in the right lung field suggesting a pulmonary contusion or traumatic lung edema. Ten days after the initial injury, he was cleared for full participation. We herein reported the first case of a lung lesion induced by a soccer ball. Conservative treatment resulted in a favorable outcome.

Dark matter gravitinos and baryons via Q-ball decay in the gauge-mediated MSSM

Energy Technology Data Exchange (ETDEWEB)

Doddato, Francesca; McDonald, John, E-mail: f.doddato@lancaster.ac.uk, E-mail: j.mcdonald@lancaster.ac.uk [Lancaster-Manchester-Sheffield Consortium for Fundamental Physics, Cosmology and Astroparticle Physics Group, Dept. of Physics, University of Lancaster, Lancaster LA1 4YB (United Kingdom)

2013-07-01

We show that late Q-ball decay in the MSSM with gauge-mediated SUSY breaking can provide a natural source of non-thermal NLSPs which subsequently decay to gravitino dark matter without violating nucleosynthesis constraints. To show this, we perform a global analysis of Q-ball formation and decay in Affleck-Dine baryogenesis for a d = 6 (u{sup c}d{sup c}d{sup c}){sup 2} flat direction of the gauge-mediated MSSM. A general phenomenological potential for the flat-direction is studied and the Q-ball decay properties are obtained as a function of its parameters. The corresponding gravitino mass necessary to account for dark matter is then determined for the case of stau NLSPs. The decay temperature depends on the charge of the Q-balls, which is determined by the fragmentation of the AD condensate. Different fragmentation scenarios are considered, and the final non-thermal NLSP density from Q-ball decay and NLSP annihilation is determined. Particular care is taken to establish that NLSPs from Q-ball decay become homogeneous and non-relativistic prior to annihilation. The gravitino mass necessary for dark matter is naturally consistent with the theoretical gravitino mass in the gauge-mediation model.

Pelvic rotation torque during fast-pitch softball hitting under three ball height conditions.

Science.gov (United States)

Iino, Yoichi; Fukushima, Atsushi; Kojima, Takeji

2014-08-01

The purpose of this study was to investigate the relevance of hip joint angles to the production of the pelvic rotation torque in fast-pitch softball hitting and to examine the effect of ball height on this production. Thirteen advanced female softball players hit stationary balls at three different heights: high, middle, and low. The pelvic rotation torque, defined as the torque acting on the pelvis through the hip joints about the pelvic superior-inferior axis, was determined from the kinematic and force plate data using inverse dynamics. Irrespective of the ball heights, the rear hip extension, rear hip external rotation, front hip adduction, and front hip flexion torques contributed to the production of pelvic rotation torque. Although the contributions of the adduction and external rotation torques at each hip joint were significantly different among the ball heights, the contributions of the front and rear hip joint torques were similar among the three ball heights owing to cancelation of the two torque components. The timings of the peaks of the hip joint torque components were significantly different, suggesting that softball hitters may need to adjust the timings of the torque exertions fairly precisely to rotate the upper body effectively.

An autopsy case related to a terrorist attack using a ball-bearing bomb.

Science.gov (United States)

Takamiya, Masataka; Biwasaka, Hitoshi; Niitsu, Hisae; Saigusa, Kiyoshi; Aoki, Yasuhiro

2009-03-01

We encountered an autopsy case related to a terrorist attack using a ball-bearing bomb. The decedent was a 51-year-old male without significant medical histories. During dinner in a restaurant, the perpetrator suddenly exploded a ball-bearing bomb, the blast from which blew the victim off his chair. The victim was found to be unresponsive, and pronounced dead. X-ray photographs taken before autopsy revealed six spherical shadows. Three penetrating wounds in the head, one in the neck and chest, and two in the left upper arm were observed in vivo. Six projectiles recovered from the body were identified as ball-bearings, one of which traveled through the midbrain, diencephalon, and left temporal lobe. Although blast injuries and penetrating wounds are often combined in bomb attack victims, penetrating brain injury would be the cause of death in this case. Lethal injuries to major organs can thus occur even though the destructive force of a ball-bearing bomb is weak. X-ray films were informative for detecting the ball-bearings in this case, suggesting that autopsy imaging is essential in cases of terrorism victims.

A Steel Ball Surface Quality Inspection Method Based on a Circumferential Eddy Current Array Sensor

Directory of Open Access Journals (Sweden)

Huayu Zhang

2017-07-01

Full Text Available To efficiently inspect surface defects on steel ball bearings, a new method based on a circumferential eddy current array (CECA sensor was proposed here. The best probe configuration, in terms of the coil quality factor (Q-factor, magnetic field intensity, and induced eddy current density on the surface of a sample steel ball, was determined using 3-, 4-, 5-, and 6-coil probes, for analysis and comparison. The optimal lift-off from the measured steel ball, the number of probe coils, and the frequency of excitation current suitable for steel ball inspection were obtained. Using the resulting CECA sensor to inspect 46,126 steel balls showed a miss rate of ~0.02%. The sensor was inspected for surface defects as small as 0.05 mm in width and 0.1 mm in depth.

Lucille Ball, the Queen of Show Business versus Lucy Ricardo, the Failed Actress

Directory of Open Access Journals (Sweden)

Aurélie Blot

2011-04-01

Full Text Available Most American people, all generations taken into account, remember Lucille Ball as a great comic figure of the Fifties. Nonetheless, just a few people remember her as one of the most powerful women of her time. This might be because Lucille Ball refused to be considered as a businesswoman; she wanted to be seen as an actress above all. In this article, I will analyze how Lucille Ball became a businesswoman in spite of herself and how her success as an actress contributed to her success as a businesswoman.

Ball Milling Assisted Solvent and Catalyst Free Synthesis of Benzimidazoles and Their Derivatives.

Science.gov (United States)

El-Sayed, Taghreed H; Aboelnaga, Asmaa; Hagar, Mohamed

2016-08-24

Benzoic acid and o-phenylenediamine efficiently reacted under the green solvent-free Ball Milling method. Several reaction parameters were investigated such as rotation frequency; milling balls weight and milling time. The optimum reaction condition was milling with 56.6 g weight of balls at 20 Hz frequency for one hour milling time. The study was extended for synthesis of a series of benzimidazol-2-one or benzimidazol-2-thione using different aldehydes; carboxylic acids; urea; thiourea or ammonium thiocyanate with o-phenylenediamine. Moreover; the alkylation of benzimidazolone or benzimidazolthione using ethyl chloroacetate was also studied.

Interference-Fit Life Factors for Ball Bearings

Science.gov (United States)

Oswald, Fred B.; Zaretsky, Erwin V.; Poplawski, Joseph V.

2010-01-01

The effect of hoop stresses on the rolling-element fatigue life of angular-contact and deep-groove ball bearings was determined for common inner-ring interference fits at the ABEC-5 tolerance level. The analysis was applied to over 1150 bearing configurations and load cases. Hoop stresses were superimposed on the Hertzian principal stresses created by the applied bearing load to calculate the inner-race maximum shearing stress. The resulting fatigue life of the bearing was recalculated through a series of equations. The reduction in the fatigue life is presented as life factors that are applied to the unfactored bearing life. The life factors found in this study ranged from 1.00 (no life reduction)--where there was no net interface pressure--to a worst case of 0.38 (a 62-percent life reduction). For a given interference fit, the reduction in life is different for angular-contact and deep-groove ball bearings. Interference fits also affect the maximum Hertz stress-life relation. Experimental data of Czyzewski, showing the effect of interference fit on rolling-element fatigue life, were reanalyzed to determine the shear stress-life exponent. The Czyzewski data shear stress-life exponent c equals 8.77, compared with the assumed value of 9. Results are presented as tables and charts of life factors for angular-contact and deep-groove ball bearings with light, normal, and heavy loads and interference fits ranging from extremely light to extremely heavy.

Process intensification effect of ball milling on the hydrothermal pretreatment for corn straw enzymolysis

International Nuclear Information System (INIS)

Yuan, Zhengqiu; Long, Jinxing; Wang, Tiejun; Shu, Riyang; Zhang, Qi; Ma, Longlong

2015-01-01

Highlights: • Novel pretreatment of ball milling combined with hydrothermal method was presented. • Intensification effect of ball milling was significant for corn straw enzymolysis. • Ball milling destroyed the physical structure of corn straw. • Chemical (liquid mixture) method removed lignin and hemicellulose. • Glucose yield increased from 0.41 to 13.86 mg mL −1 under the optimized condition. - Abstract: Enhancement of the cellulose accessibility is significant for biomass enzymatic hydrolysis. Here, we reported an efficient combined pretreatment for corn straw enzymolysis using ball milling and dilute acid hydrothermal method (a mixture solvent of H 2 O/ethanol/sulfuric acid/hydrogen peroxide liquid). The process intensification effect of ball milling on the pretreatment of the corn straw was studied through the comparative characterization of the physical–chemical properties of the raw and pretreated corn straw using FT-IR, BET, XRD, SEM, and HPLC analysis. The effect of the pretreatment temperature was also investigated. Furthermore, various pretreatment methods were compared as well. Moreover, the pretreatment performance was measured by enzymolysis. The results showed that ball milling had a significant process intensification effect on the corn straw enzymolysis. The glucose concentration was dramatically increased from 0.41 to 13.86 mg mL −1 after the combined treatment of ball milling and hydrothermal. The efficient removal of lignin and hemicellulose and the enlargement of the surface area were considered to be responsible for this significant increase based on the intensive analysis on the main components and the physical–chemical properties of the raw and pretreated corn straw

The documentation of tar balls on oiled shorelines : lessons from the New Carissa, Oregon

International Nuclear Information System (INIS)

Owens, E.H.; Zimlicki-Owens, L.M.; Lamarche, A.; Reimer, P.D.; Martin, C.A.

2000-01-01

The New Carissa, carrying approximately 400,000 gallons of fuel oils ran aground on the outer shore of North Spit, in the vicinity of Coos Bay, Oregon, on February 4, 1999. The oil was released directly into the nearshore surf zone. Following the spill, a stretch of approximately 300 km of the coast of Oregon was surveyed and monitored. The need for the documentation of stranded tar balls in the neighbourhood of the spill site prompted the implementation of a long-term observation program. Initially, Shoreline Clean-up and Assessment Technique (SCAT) reporting procedures were required. Heavy oiling was followed by stranded oil taking the form of tar balls. The amount of oil on the shoreline decreased and the SCAT procedures alone were no longer adequate. They provided estimations of oil quantities that were too high and failed to provide any discrimination between amounts of oil observed on the beaches. A new reporting technique called Beach Assessment Reporting was designed to overcome the difficulties and record adequately the character and frequency of stranded tar balls. Maps, tables and histograms of stranded tar ball volumes and concentrations were discussed. Since the data spanned nine orders of magnitude at times, the semi-logarithmic scale time series plots of the concentration of the tar balls was used in order to identify trends. Conventional histograms only identified large values and camouflaged smaller trends in the time series. A direct method for describing tar ball concentrations geographically proved to be the use of weekly maximum tar ball concentration maps by segment. 10 refs., 2 tabs., 9 figs

Real-time MR diffusion tensor and Q-ball imaging using Kalman filtering

International Nuclear Information System (INIS)

Poupon, C.; Roche, A.; Dubois, J.; Mangin, J.F.; Poupon, F.

2008-01-01

Diffusion magnetic resonance imaging (dMRI) has become an established research tool for the investigation of tissue structure and orientation. In this paper, we present a method for real-time processing of diffusion tensor and Q-ball imaging. The basic idea is to use Kalman filtering framework to fit either the linear tensor or Q-ball model. Because the Kalman filter is designed to be an incremental algorithm, it naturally enables updating the model estimate after the acquisition of any new diffusion-weighted volume. Processing diffusion models and maps during ongoing scans provides a new useful tool for clinicians, especially when it is not possible to predict how long a subject may remain still in the magnet. First, we introduce the general linear models corresponding to the two diffusion tensor and analytical Q-ball models of interest. Then, we present the Kalman filtering framework and we focus on the optimization of the diffusion orientation sets in order to speed up the convergence of the online processing. Last, we give some results on a healthy volunteer for the online tensor and the Q-ball model, and we make some comparisons with the conventional offline techniques used in the literature. We could achieve full real-time for diffusion tensor imaging and deferred time for Q-ball imaging, using a single workstation. (authors)

Physical characteristics that predict involvement with the ball in recreational youth soccer.

Science.gov (United States)

Ré, Alessandro H Nicolai; Cattuzzo, Maria Teresa; Henrique, Rafael Dos Santos; Stodden, David F

2016-09-01

This study examined the relative contribution of age, stage of puberty, anthropometric characteristics, health-related fitness, soccer-specific tests and match-related technical performance to variance in involvements with the ball during recreational 5-a-side small-sided (32 × 15 m) soccer matches. Using a cross-sectional design, 80 healthy male students (14.6 ± 0.5 years of age; range 13.6-15.4) who played soccer recreationally were randomly divided into 10 teams and played against each other. Measurements included height, body mass, pubertal status, health-related fitness (12-min walk/run test, standing long jump, 15-m sprint and sit-ups in 30 s), soccer-specific tests (kicking for speed, passing for accuracy and agility run with and without a ball), match-related technical performance (kicks, passes and dribbles) and involvements with the ball during matches. Forward multiple regression analysis revealed that cardiorespiratory fitness (12-min walk/run test) accounted for 36% of the variance in involvements with the ball. When agility with the ball (zigzag running) and power (standing long jump) were included among the predictors, the total explained variance increased to 62%. In conclusion, recreational adolescent players, regardless of their soccer-specific skills, may increase participation in soccer matches most through physical activities that promote improvement in cardiorespiratory fitness, muscle power and agility.

Commissioning of the Cryogenic Plant for the Cryogenic Storage Ring (CSR) at Heidelberg

CERN Document Server

von Hahn, R; Grieser, M; Haberstroh, C; Kaiser, D; Lange, M; Laux, F; Menk, S; Orlov, D A; Repnow, R; Sieber, T; Quack, H; Varju, J; Wolf A

2009-01-01

At the Max-Planck-Institute for Nuclear Physics in Heidelberg a next generation electrostatic storage ring for low velocity atomic and molecular ion beams is under construction. In contrast to existing electrostatic storage rings, the Cryogenic Storage Ring CSR will be cooled down to temperatures below 2 K. Thus acting as a large cryopump it will provide long storage times and, in addition, open a new field of quantum state controlled molecular physics due to a low heat radiation background from space-like environment. A concept for cooling the storage ring has been developed and is presently tested by means of a linear trap as a prototype with a length of 1/10 of the planned ring. A commercial refrigerator with 21 W at 2 K has been successfully commissioned and was connected to the prototype. This paper presents the status of the cryogenic plant after the commissioning and one year of operation.

Magnetic interactions in high-energy ball-milled NiZnFe2O4/SiO2 composites

International Nuclear Information System (INIS)

Pozo Lopez, G.; Silvetti, S.P.; Urreta, S.E.; Cabanillas, E.D.

2007-01-01

Composites Ni 0.5 Zn 0.5 Fe 2 O 4 /SiO 2 are obtained after high-energy ball milling precursor oxides, in stoichiometric proportions, for 200 h at room temperature and further isothermal annealing for 1 h at 1273 K, under air and argon atmosphere, respectively. After 200 h grinding, a complex microstructure develops with small hematite crystals mixed with SiO 2 and remanent NiO and ZnO particles, and very small NiZn ferrite clusters, reaching a mean size of ∼9 nm. The high temperature treatments remove the hematite grains from the powder and promote the growth of NiZn ferrite grains to reach mean sizes nearly ∼20 nm. For treatments in oxidizing atmospheres, the major phases are SiO 2 and NiZn ferrite, while for annealing in Ar a new phase appears, fayalite, which is paramagnetic at room temperature. The M-H loops are all well described by the sum of a ferromagnetic and a superparamagnetic-like contribution. The observed properties are interpreted considering the different magnetic phases obtained, their crystal sizes and their mutual interactions

The Soccer-Ball Problem

Science.gov (United States)

Hossenfelder, Sabine

2014-07-01

The idea that Lorentz-symmetry in momentum space could be modified but still remain observer-independent has received quite some attention in the recent years. This modified Lorentz-symmetry, which has been argued to arise in Loop Quantum Gravity, is being used as a phenomenological model to test possibly observable effects of quantum gravity. The most pressing problem in these models is the treatment of multi-particle states, known as the 'soccer-ball problem'. This article briefly reviews the problem and the status of existing solution attempts.

Wiffle Ball: Turning a Backyard Favorite into an Appropriate Physical Education Unit

Science.gov (United States)

Layne, Todd E.

2017-01-01

Wiffle ball is a game that has been played for many years (Santora, 2003). Unfortunately, implementation in physical education has been inconsistent at best. The sport education model outlined in this article provides an appropriate method for teaching skills associated with wiffle ball for a variety of ages. Students can develop appropriate…

Pilot study of ice-ball cryotherapy for radiation-induced oral mucositis

International Nuclear Information System (INIS)

Ohyama, Waichiro; Ebihara, Satoshi

1996-01-01

Oral mucositis caused by radiotherapy is intractable and may worsen the patient's nutritional condition and interrupt treatment. To reduce the incidence and severity of oral mucositis induced by cancer therapy and promote early improvement of its symptoms, we devised cryotherapy by ice balls using Elase (fibrinolysin and deoxyribonuclease, combined). The therapeutic effect of ice-ball cryotherapy was evaluated in 10 patients with carcinoma of the oral cavity and pharynx who were undergoing radiotherapy. Cryotherapy was continued from the development of oral mucositis until its disappearance. The severity of various symptoms of mucositis were reduced by cryotherapy. Healing required 3 to 16 days (median, 7 days) after the end of radiotherapy. Radiotherapy was not interrupted in any cases. This preliminary report suggests that ice-ball cryotherapy is an effective treatment for radiation-induced oral mucositis. (author)

Prospective versus predictive control in timing of hitting a falling ball.

Science.gov (United States)

Katsumata, Hiromu; Russell, Daniel M

2012-02-01

Debate exists as to whether humans use prospective or predictive control to intercept an object falling under gravity (Baurès et al. in Vis Res 47:2982-2991, 2007; Zago et al. in Vis Res 48:1532-1538, 2008). Prospective control involves using continuous information to regulate action. τ, the ratio of the size of the gap to the rate of gap closure, has been proposed as the information used in guiding interceptive actions prospectively (Lee in Ecol Psychol 10:221-250, 1998). This form of control is expected to generate movement modulation, where variability decreases over the course of an action based upon more accurate timing information. In contrast, predictive control assumes that a pre-programmed movement is triggered at an appropriate criterion timing variable. For a falling object it is commonly argued that an internal model of gravitational acceleration is used to predict the motion of the object and determine movement initiation. This form of control predicts fixed duration movements initiated at consistent time-to-contact (TTC), either across conditions (constant criterion operational timing) or within conditions (variable criterion operational timing). The current study sought to test predictive and prospective control hypotheses by disrupting continuous visual information of a falling ball and examining consistency in movement initiation and duration, and evidence for movement modulation. Participants (n = 12) batted a ball dropped from three different heights (1, 1.3 and 1.5 m), under both full-vision and partial occlusion conditions. In the occlusion condition, only the initial ball drop and the final 200 ms of ball flight to the interception point could be observed. The initiation of the swing did not occur at a consistent TTC, τ, or any other timing variable across drop heights, in contrast with previous research. However, movement onset was not impacted by occluding the ball flight for 280-380 ms. This finding indicates that humans did not

Sensitivity of the speed evaluation tests of carrying the ball in youth soccer players

Directory of Open Access Journals (Sweden)

Rakojević Bojan

2016-01-01

Full Text Available This research is aimed at examining sensitivity of the speed evaluation tests while carrying the ball. The research included 76 male examinees, aged 17 years (+/- 6 months, who were divided into two qualitatively different subgroups. For determining the speed while carrying the ball, the tests of M type of carrying the ball between cones and slalom ball carrying with a pass were performed. The obtained results proved that the examinees from the group of more successful soccer players (Group 1 scored better on the applied tests when compared to the results of the group consisting of the soccer players from lower ranked clubs and who are not national team members (Group 2. High values of the result homogeneity in the two groups (for the Groups 1 and 2 it was 75% and 68.75% respectively lead to the conclusion that this ability is essential characteristics of young soccer players. The coefficient of discrimination of 0.269 for the results of M type test and 0.197 for the results of the test of carrying the ball with a pass indicate that the results of the two tests provide possibility to qualitatively distinguish youth players. Therefore, it can be concluded that as a technical element, carrying the ball significantly affects the quality of players' performance.

Ball lightning from atmospheric discharges via metal nanosphere oxidation: from soils, wood or metals.

Science.gov (United States)

Abrahamson, John

2002-01-15

The slow (diffusion-limited) oxidation of metal nanoparticles has previously been proposed as the mechanism for ball lightning energy release, and argued to be the result of a normal lightning strike on soil. Here this basic model of networked nanoparticles is detailed further, and extended to lightning strikes on metal structures, and also to the action of other storm-related discharges or man-made discharges. The basic model predicted the important properties of "average" observed ball lightning, and the extension in this paper also covers high-energy examples of ball lightning. Laboratory checks of the theory are described, and predictions given of what conditions are necessary for observing ball lightning in the laboratory. Key requirements of the model are a sheltered region near the strike foot and starting materials which can generate a metal vapour under intensive heating, including soil, wood or a metal structure. The evolution of hydrocarbons (often plastics) along with metal vapour can ensure the local survival of the metal vapour even in an oxidizing atmosphere. Subsequent condensation of this vapour to metallic nanoparticles in networks provides the coherence of a ball structure, which also releases light over an extended time. Also discussed is the passage of ball lightning through a sheet of building material, including glass, and its occasional charring of flesh on close contact.

Fractal Aggregates in Tennis Ball Systems

Science.gov (United States)

Sabin, J.; Bandin, M.; Prieto, G.; Sarmiento, F.

2009-01-01

We present a new practical exercise to explain the mechanisms of aggregation of some colloids which are otherwise not easy to understand. We have used tennis balls to simulate, in a visual way, the aggregation of colloids under reaction-limited colloid aggregation (RLCA) and diffusion-limited colloid aggregation (DLCA) regimes. We have used the…

From a Ball Game to Incompleteness

Indian Academy of Sciences (India)

We present a ball game that can be continued as long as wewish. It looks as though the game would never end. But byapplying a result on trees, we show that the game nonethelessends in some finite number of moves. We then point out somedeep results on the natural number system connected withthe game.

Acquisition and reduction of data obtained from Tank 101-SY in-situ ball rheometer

International Nuclear Information System (INIS)

Shepard, C.L.; Chieda, M.A.; Kirihara, L.J.

1994-12-01

Development of the ball rheometer to measure rheological properties and density of the waste in Hanford Tank 241-SY-101 will be completed around September 1994. Since the ball rheometer project began, a mixer pump has been installed in this tank, and by all accounts this pump has been very successful at mitigating the flammable gas problem associated with Tank 101-SY. Present plans now call for the use of mixer pumps in several other tanks. The ball rheometer will serve as a diagnostic tool for judging the effectiveness of mixing in Tank 101-SY and others and will be one of few in-situ probes available for diagnostic measurements. The in-situ data collection strategy and the methods of data analysis and reduction are presented in this final report concerning this instrument. It is believed that a generalized Bingham fluid model (Herschel-Bulkley fluid model) may be useful for describing at least some of the waste contained in Tank 101-SY, and data obtained in the tank will initially be reduced using this fluid model. The single largest uncertainty in the determination of the drag force on the ball is the drag force which will be experienced by the cable attached to the ball. This drag can be a substantial fraction of the total drag when the ball is deep within the tank. Careful accounting of the cable drag will be important in the reduction of the data. The data collection strategy allows the determination of the waste fluid rheology both in the undisturbed state and after it has been disturbed by the ball. Fluid density will be measured at regular intervals

Homologous stress adaptation, antibiotic resistance, and biofilm forming ability of Salmonella enterica serovar Heidelberg (ATCC8326) on different food-contact surfaces following exposure to sub-lethal chlorine concentrations

Science.gov (United States)

Salmonella enterica serovar Heidelberg (American Type Culture Collection; ATCC 8326) was examined for the ability to adapt to the homologous stress of chlorine through exposure to increasing chlorine concentrations (25 ppm daily increments) in tryptic soy broth (TSB). The tested strain exhibited an ...

Failure analysis of the ball bearings of dental air turbine handpieces.

Science.gov (United States)

Wei, M; Dyson, J E; Darvell, B W

2013-12-01

The aim of this study was to identify the nature and causes of deterioration and failure in dental handpiece ball bearings and thus provide guidance for clinical handling for service longevity. The bearings of 36 turbine assemblies were dismantled for visual inspection, documented using a digital camera, and examined using scanning electron microscopy, as appropriate. For the metal parts of the ball bearing assembly, defects observed were mainly wear arising from the running load and corrosion. This was in the form of scratches and discoloured circumferential bands on the balls, and dull or worn surfaces extending around the circumference of the raceways. Cage damage including cracking, fracture, surface rubbing and distortion occurred, in varying degrees, in every failed turbine. Dental ball bearing failure modes have been identified. Cumulative effects of damage from corrosion and mechanical factors lead to handpiece deterioration. The cage was found to be very vulnerable to damage, and this may be the key limitation on bearing lifetime. Autoclaving may contribute to that, as it does to corrosion in the absence of adequate lubrication, but this seems to be minor in comparison to the effects of abuse. There is no justification for failing to observe usage and sterilization instructions. © 2013 Australian Dental Association.

Casimir Energies for Isorefractive or Diaphanous Balls

Directory of Open Access Journals (Sweden)

Kimball A. Milton

2018-03-01

Full Text Available It is known that the Casimir self-energy of a homogeneous dielectric ball is divergent, although a finite self-energy can be extracted through second order in the deviation of the permittivity from the vacuum value. The exception occurs when the speed of light inside the spherical boundary is the same as that outside, so the self-energy of a perfectly conducting spherical shell is finite, as is the energy of a dielectric-diamagnetic sphere with ε μ = 1 , a so-called isorefractive or diaphanous ball. Here we re-examine that example and attempt to extend it to an electromagnetic δ -function sphere, where the electric and magnetic couplings are equal and opposite. Unfortunately, although the energy expression is superficially ultraviolet finite, additional divergences appear that render it difficult to extract a meaningful result in general, but some limited results are presented.

Relative locality and the soccer ball problem

International Nuclear Information System (INIS)

Amelino-Camelia, Giovanni; Freidel, Laurent; Smolin, Lee; Kowalski-Glikman, Jerzy

2011-01-01

We consider the behavior of macroscopic bodies within the framework of relative locality [G. Amelino-Camelia, L. Freidel, J. Kowalski-Glikman, and L. Smolin, arXiv:1101.0931]. This is a recent proposal for Planck scale modifications of the relativistic dynamics of particles which are described as arising from deformations in the geometry of momentum space. We consider and resolve a common objection against such proposals, which is that, even if the corrections are small for elementary particles in current experiments, they are huge when applied to composite systems such as soccer balls, planets, and stars, with energies E macro much larger than M P . We show that this soccer ball problem does not arise within the framework of relative locality because the nonlinear effects for the dynamics of a composite system with N elementary particles appear at most of order E macro /N·M P .

Pilot study of ice-ball cryotherapy for radiation-induced oral mucositis

Energy Technology Data Exchange (ETDEWEB)

Ohyama, Waichiro; Ebihara, Satoshi [National Cancer Center Hospital, Tokyo (Japan)

1996-02-01

Oral mucositis caused by radiotherapy is intractable and may worsen the patient`s nutritional condition and interrupt treatment. To reduce the incidence and severity of oral mucositis induced by cancer therapy and promote early improvement of its symptoms, we devised cryotherapy by ice balls using Elase (fibrinolysin and deoxyribonuclease, combined). The therapeutic effect of ice-ball cryotherapy was evaluated in 10 patients with carcinoma of the oral cavity and pharynx who were undergoing radiotherapy. Cryotherapy was continued from the development of oral mucositis until its disappearance. The severity of various symptoms of mucositis were reduced by cryotherapy. Healing required 3 to 16 days (median, 7 days) after the end of radiotherapy. Radiotherapy was not interrupted in any cases. This preliminary report suggests that ice-ball cryotherapy is an effective treatment for radiation-induced oral mucositis. (author).

High-energy ball milling of powder B-C mixtures

International Nuclear Information System (INIS)

Ramos, Alfeu S.; Taguchi, Simone P.; Ramos, Erika C.T.; Arantes, Vera L.; Ribeiro, Sebastiao

2006-01-01

The present work reports on the preparation of B-10 at.% C and B-18 at.% C powders by high-energy ball milling and further heat treatment. The milling process was carried out in a planetary ball mill. Following the milling process, powder samples were heat-treated at 1200 deg. C for 4 h using inert atmosphere. The milled and heat-treated B-10C and B-18C powders were characterized by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. A reduction on the intensity of B and C peaks was noticed after milling for 2 h, probably due the fine powder particle sizes because the pronounced fracture mechanism during ball milling of brittle starting components. The XRD patterns of B-10C and B-18C powders milled for 6 h indicated the presence of other peaks, suggesting that a metastable structure could have been formed. After milling for 90 h, these unknown peaks were still present. A large amount of B 4 C was formed after heat treatment at 1200 deg. C for 4 h beside these unknown peaks

Health and Physiological Adaptations of Small-Sided Ball Games in Untrained Older Adults Aged 65-93 Years

DEFF Research Database (Denmark)

Vorup Petersen, Jacob

function, and 3) the feasibility, motivation and injury rate of regular small-sided ball games in untrained elderly. Purpose. The overall aims of the present thesis were to examine physiological adaptations important for health after a period of small-sided ball game training and protein ingestion...... adults, 16 weeks of small-sided soccer was shown to improve physical function and exercise capacity, whereas muscle mass was unaffected by the training despite a high intake of daily protein. However, a number of questions still need to be answered regarding small-sided ball game training in untrained...... elderly: 1) The effect of other small-sided ball games, e.g. floorball training and cone ball, on physiological adaptations important for health as well as the effect of combined protein intake, 2) the effect of regular small-sided ball games in older adults with a more advanced age and low physical...

Ammonia synthesis over multi-promoted iron catalysts obtained by high-energy ball-milling

DEFF Research Database (Denmark)

Jacobsen, C.J.H.; Jiang, Jianzhong; Mørup, Steen

1999-01-01

The feasibility of producing ammonia synthesis catalysts from high-energy ball-milling of a simple mixture of the constituent oxides has been investigated. The effect of ball-milling the fused oxidic precursor of the industrial KM1 ammonia synthesis catalyst has also been studied. The results show...

When Two Balls Are Just One

Science.gov (United States)

Kulp, Christopher W.; Biermann, Mark L.; Howard, Timothy; Klingenberg, Kurtis; Ramsey, Paul

2008-01-01

A camcorder can be a powerful tool in pedagogical settings, such as in an introductory physics course or in introducing undergraduates to data collection. In this paper, we discuss our experience using a Panasonic PV-GS150 digital camcorder to analyze the motion of a falling steel ball, with the goal of determining the acceleration due to gravity,…

Synthesis and gas-sensing characteristics of α-Fe2O3 hollow balls

Directory of Open Access Journals (Sweden)

Chu Manh Hung

2016-03-01

Full Text Available The synthesis of porous metal-oxide semiconductors for gas-sensing application is attracting increased interest. In this study, α-Fe2O3 hollow balls were synthesized using an inexpensive, scalable, and template-free hydrothermal method. The gas-sensing characteristics of the semiconductors were systematically investigated. Material characterization by XRD, SEM, HRTEM, and EDS reveals that single-phase α-Fe2O3 hollow balls with an average diameter of 1.5 μm were obtained. The hollow balls were formed by self assembly of α-Fe2O3 nanoparticles with an average diameter of 100 nm. The hollow structure and nanopores between the nanoparticles resulted in the significantly high response of the α-Fe2O3 hollow balls to ethanol at working temperatures ranging from 250 °C to 450 °C. The sensor also showed good selectivity over other gases, such as CO and NH3 promising significant application.

3D Printing of Ball Grid Arrays

Science.gov (United States)

Sinha, Shayandev; Hines, Daniel; Dasgupta, Abhijit; Das, Siddhartha

Ball grid arrays (BGA) are interconnects between an integrated circuit (IC) and a printed circuit board (PCB), that are used for surface mounting electronic components. Typically, lead free alloys are used to make solder balls which, after a reflow process, establish a mechanical and electrical connection between the IC and the PCB. High temperature processing is required for most of these alloys leading to thermal shock causing damage to ICs. For producing flexible circuits on a polymer substrate, there is a requirement for low temperature processing capabilities (around 150 C) and for reducing strain from mechanical stresses. Additive manufacturing techniques can provide an alternative methodology for fabricating BGAs as a direct replacement for standard solder bumped BGAs. We have developed aerosol jet (AJ) printing methods to fabricate a polymer bumped BGA. As a demonstration of the process developed, a daisy chain test chip was polymer bumped using an AJ printed ultra violet (UV) curable polymer ink that was then coated with an AJ printed silver nanoparticle laden ink as a conducting layer printed over the polymer bump. The structure for the balls were achieved by printing the polymer ink using a specific toolpath coupled with in-situ UV curing of the polymer which provided good control over the shape, resulting in well-formed spherical bumps on the order of 200 um wide by 200 um tall for this initial demonstration. A detailed discussion of the AJ printing method and results from accelerated life-time testing will be presented

Ball milling of chalcopyrite: Moessbauer spectroscopy and XRD studies

International Nuclear Information System (INIS)

Pollak, H.; Fernandes, M.; Levendis, D.; Schonig, L.

1999-01-01

The aim of this project is to study the behavior of chalcopyrite under ball milling for extended periods in order to determine how it's decompose or transform. Tests were done with chalcopyrite mixed with iron and zinc with and without surfactant. The use of surfactants has various effects such as avoiding oxidation and clustering of the fine particles. In all case magnetic chalcopyrite is transformed into a paramagnetic component showing a disordered structure, thus revealing that Cu atoms have replaced Fe atoms. In the case of ball milling in air, chalcopyrite is decomposed with the lost of iron, while in milling under surfactants, iron enters into the chalcopyrite structure. (author)

Charge, mass and energy measured in the Plastic Ball

International Nuclear Information System (INIS)

Gustafsson, H.A.; Gutbrod, H.H.; Kolb, B.

1984-01-01

In relativistic nuclear collisions the multiplicity of charged particles reflects the violence of the reaction and, presumably, the impact parameter. Furthermore, the total transverse energy in a collision might be a signature of compression. Both quantities are global features that can be measured in the Plastic Ball. The total mass in an event in light charge fragments can be detected (with assumptions made in certain kinematic regions) through particle identification. In addition, the neutron detection efficiency is quite high because of the large thickness of the plastic scintillator in the Plastic Ball. Here the authors present several global quantities for the reaction of 400 MeV/nucleon Nb + Nb

Ball driven type MEMS SAD for artillery fuse

International Nuclear Information System (INIS)

Seok, Jin Oh; Jeong, Ji-hun; Eom, Junseong; Lee, Seung S; Lee, Chun Jae; Ryu, Sung Moon; Oh, Jong Soo

2017-01-01

The SAD (safety and arming device) is an indispensable fuse component that ensures safe and reliable performance during the use of ammunition. Because the application of electronic devices for smart munitions is increasing, miniaturization of the SAD has become one of the key issues for next-generation artillery fuses. Based on MEMS technology, various types of miniaturized SADs have been proposed and fabricated. However, none of them have been reported to have been used in actual munitions due to their lack of high impact endurance and complicated explosive train arrangements. In this research, a new MEMS SAD using a ball driven mechanism, is successfully demonstrated based on a UV LIGA (lithography, electroplating and molding) process. Unlike other MEMS SADs, both high impact endurance and simple structure were achieved by using a ball driven mechanism. The simple structural design also simplified the fabrication process and increased the processing yield. The ball driven type MEMS SAD performed successfully under the desired safe and arming conditions of a spin test and showed fine agreement with the FEM simulation result, conducted prior to its fabrication. A field test was also performed with a grenade launcher to evaluate the SAD performance in the firing environment. All 30 of the grenade samples equipped with the proposed MEMS SAD operated successfully under the high-G setback condition. (paper)

Ball driven type MEMS SAD for artillery fuse

Science.gov (United States)

Seok, Jin Oh; Jeong, Ji-hun; Eom, Junseong; Lee, Seung S.; Lee, Chun Jae; Ryu, Sung Moon; Oh, Jong Soo

2017-01-01

The SAD (safety and arming device) is an indispensable fuse component that ensures safe and reliable performance during the use of ammunition. Because the application of electronic devices for smart munitions is increasing, miniaturization of the SAD has become one of the key issues for next-generation artillery fuses. Based on MEMS technology, various types of miniaturized SADs have been proposed and fabricated. However, none of them have been reported to have been used in actual munitions due to their lack of high impact endurance and complicated explosive train arrangements. In this research, a new MEMS SAD using a ball driven mechanism, is successfully demonstrated based on a UV LIGA (lithography, electroplating and molding) process. Unlike other MEMS SADs, both high impact endurance and simple structure were achieved by using a ball driven mechanism. The simple structural design also simplified the fabrication process and increased the processing yield. The ball driven type MEMS SAD performed successfully under the desired safe and arming conditions of a spin test and showed fine agreement with the FEM simulation result, conducted prior to its fabrication. A field test was also performed with a grenade launcher to evaluate the SAD performance in the firing environment. All 30 of the grenade samples equipped with the proposed MEMS SAD operated successfully under the high-G setback condition.

Spatiotemporal characteristics of muscle patterns for ball catching

Directory of Open Access Journals (Sweden)

Mattia eD'Andola

2013-08-01

Full Text Available What sources of information and what control strategies the CNS uses to perform movements that require accurate sensorimotor coordination, such as catching a flying ball, is still debated. Here we analyzed the EMG waveforms recorded from 16 shoulder and elbow muscles in six subjects during catching of balls projected frontally from a distance of 6 m and arriving at two different heights and with three different flight times (550, 650, 750 ms. We found that a large fraction of the variation in the muscle patterns was captured by two time-varying muscle synergies, coordinated recruitment of groups of muscles with specific activation waveforms, modulated in amplitude and shifted in time according to the ball’s arrival height and flight duration. One synergy was recruited with a short and fixed delay from launch time. Remarkably, a second synergy was recruited at a fixed time before impact, suggesting that it is timed according to an accurate time-to-contact estimation. These results suggest that the control of interceptive movements relies on a combination of reactive and predictive processes through the intermittent recruitment of time-varying muscle synergies. Knowledge of the dynamic effect of gravity and drag on the ball may be then implicitly incorporated in a direct mapping of visual information into a small number of synergy recruitment parameters.

48 CFR 252.225-7016 - Restriction on acquisition of ball and roller bearings.

Science.gov (United States)

2010-10-01

... of ball and roller bearings. 252.225-7016 Section 252.225-7016 Federal Acquisition Regulations System... and roller bearings. As prescribed in 225.7009-5, use the following clause: Restriction on Acquisition of Ball and Roller Bearings (MAR 2006) (a) Definitions. As used in this clause' (1) Bearing...

Ball on a beam: stabilization under saturated input control with large basin of attraction

International Nuclear Information System (INIS)

Aoustin, Yannick; Formal'skii, Alexander

2009-01-01

This article is devoted to the stabilization of two underactuated planar systems, the well-known straight beam-and-ball system and an original circular beam-and-ball system. The feedback control for each system is designed, using the Jordan form of its model, linearized near the unstable equilibrium. The limits on the voltage, fed to the motor, are taken into account explicitly. The straight beam-and-ball system has one unstable mode in the motion near the equilibrium point. The proposed control law ensures that the basin of attraction coincides with the controllability domain. The circular beam-and-ball system has two unstable modes near the equilibrium point. Therefore, this device, never considered in the past, is much more difficult to control than the straight beam-and-ball system. The main contribution is to propose a simple new control law, which ensures by adjusting its gain parameters that the basin of attraction arbitrarily can approach the controllability domain for the linear case. For both nonlinear systems, simulation results are presented to illustrate the efficiency of the designed nonlinear control laws and to determine the basin of attraction

Research on Defects Inspection of Solder Balls Based on Eddy Current Pulsed Thermography

Directory of Open Access Journals (Sweden)

Xiuyun Zhou

2015-10-01

Full Text Available In order to solve tiny defect detection for solder balls in high-density flip-chip, this paper proposed feasibility study on the effect of detectability as well as classification based on eddy current pulsed thermography (ECPT. Specifically, numerical analysis of 3D finite element inductive heat model is generated to investigate disturbance on the temperature field for different kind of defects such as cracks, voids, etc. The temperature variation between defective and non-defective solder balls is monitored for defects identification and classification. Finally, experimental study is carried on the diameter 1mm tiny solder balls by using ECPT and verify the efficacy of the technique.

Characterization of Lubricants on Ball Bearings by FT-IR Using an Integrating Sphere

Science.gov (United States)

Street, K. W.; Pepper, S. V.; Wright, A. A.; Grady, B.

2007-01-01

Fourier Transform-Infrared reflectance microspectroscopy has been used extensively for the examination of coatings on nonplanar surfaces such as ball bearings. While this technique offers considerable advantages, practical application has many drawbacks, some of which are easily overcome by the use of integrating sphere technology. This paper describes the use of an integrating sphere for the quantification of thin layers of lubricant on the surface of ball bearings and the parameters which require optimization in order to obtain reliable data. Several applications of the technique are discussed including determination of lubricant load on 12.7 mm steel ball bearings and the examination of degraded lubricant on post mortem specimens.

Morphological studies of polymer dispersed liquid crystal materials

International Nuclear Information System (INIS)

Han, Jin-Woo

2006-01-01

In this work, we have studied the morphologies of polymer dispersed liquid crystals (PDLCs) based on E7/NOA61. Scanning electron microscope studies show that the PDLC morphology is strongly affected by the LC concentration and the cure temperature. A typical PDLC morphology with isolated LC droplets dispersed in a polymer matrix is only observed at low LC compositions and at low cure temperatures. Increasing either the LC composition or the cure temperature results in a polymer ball morphology, in which LCs exist in irregularly shaped voids in the polymer network structure. It is shown that the transition between these two morphologies can be qualitatively explained using a pseudo-binary phase diagram.

The Efficacy of the clay meat ball as a method of traditional meat ...

African Journals Online (AJOL)

Keywords: meat ball, protein, mineral content. This work was carried out to determine the effectiveness of the use of clay meat balls (an African traditional method of preserving meat) in extending the shelf life of meat over a period of months against microbial (bacterial and fungal) spoilage and contamination without ...

76 FR 66328 - Callaway Golf Ball Operations, Inc., Including On-Site Leased Workers From Reliable Temp Services...

Science.gov (United States)

2011-10-26

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-80,110] Callaway Golf Ball... Golf Ball Operations, Inc., including on-site leased workers from Reliable Temp Services, Inc., and... production of golf balls. The notice was published in the Federal Register on July 8, 2011 (76 FR 40401). At...

Soccer Ball Production for Nike in Pakistan

NARCIS (Netherlands)

K.A. Siegmann (Karin Astrid)

2008-01-01

textabstractThis paper looks at how Nike’s soccer ball suppliers (previous and current) in Sialkot (Pakistan) fare in relation to the company’s code of ethics. While minimum required working conditions are implemented, the criteria for social and environmental compliance are not met with. The

Use of Ball Blanket in attention-deficit/hyperactivity disorder sleeping problems

DEFF Research Database (Denmark)

Hvolby, Allan; Bilenberg, Niels

2011-01-01

Objectives: Based on actigraphic surveillance, attention-deficit/hyperactivity disorder (ADHD) symptom rating and sleep diary, this study will evaluate the effect of Ball Blanket on sleep for a sample of 8-13-year-old children with ADHD. Design: Case-control study. Setting: A child and adolescent...... psychiatric department of a teaching hospital. Participants: 21 children aged 8-13 years with a diagnosis of ADHD and 21 healthy control subjects. Intervention: Sleep was monitored by parent-completed sleep diaries and 28 nights of actigraphy. For 14 of those days, the child slept with a Ball Blanket. Main...... outcome measures: The sleep latency, number of awakenings and total length of sleep was measured, as was the possible influence on parent- and teacher-rated ADHD symptom load. Results: The results of this study will show that the time it takes for a child to fall asleep is shortened when using a Ball...

Physical abrasion method using submerged spike balls to remove algal biofilm from photobioreactors.

Science.gov (United States)

Nawar, Azra; Khoja, Asif Hussain; Akbar, Naveed; Ansari, Abeera Ayaz; Qayyum, Muneeb; Ali, Ehsan

2017-12-02

A major factor in practical application of photobioreactors (PBR) is the adhesion of algal cells onto their inner walls. Optimized algal growth requires an adequate sunlight for the photosynthesis and cell growth. Limitation in light exposure adversely affects the algal biomass yield. The removal of the biofilm from PBR is a challenging and expansive task. This study was designed to develop an inexpensive technique to prevent adhesion of algal biofilm on tubular PBR to ensure high efficiency of light utilization. Rubber balls with surface projections were introduced into the reactor, to remove the adherent biofilm by physical abrasion technique. The floatation of spike balls created a turbulent flow, thereby inhibiting further biofilm formation. The parameters such as, specific growth rate and doubling time of the algae before introducing the balls were 0.451 day -1 and 1.5 days respectively. Visible biofilm impeding light transmission was formed by 15-20 days. The removal of the biofilm commenced immediately after the introduction of the spike balls with visibly reduced deposits in 3 days. This was also validated by enhance cell count (6.95 × 106 cells mL -1 ) in the medium. The employment of spike balls in PBR is an environmental friendly and economical method for the removal of biofilm.

Crises in a dissipative bouncing ball model

Energy Technology Data Exchange (ETDEWEB)

Livorati, André L.P., E-mail: livorati@usp.br [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil); School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Caldas, Iberê L. [Instituto de Física, IFUSP, Universidade de São Paulo, USP, Rua do Matão, Tr.R 187, Cidade Universitária, 05314-970, São Paulo, SP (Brazil); Dettmann, Carl P. [School of Mathematics, University of Bristol, Bristol, BS8 1TW (United Kingdom); Leonel, Edson D. [Departamento de Física, UNESP, Universidade Estadual Paulista, Av. 24A, 1515, Bela Vista, 13506-900, Rio Claro, SP (Brazil)

2015-11-06

Highlights: • We studied a dissipative bouncing ball dynamics. • A two-dimensional nonlinear mapping describes the dynamics. • Crises between attractors and its manifolds were characterized. • A new physical crisis between vibrating platform and an attractor was characterized. • The existence of a ‘robust’ chaotic attractor was set. - Abstract: The dynamics of a bouncing ball model under the influence of dissipation is investigated by using a two-dimensional nonlinear mapping. When high dissipation is considered, the dynamics evolves to different attractors. The evolution of the basins of the attracting fixed points is characterized, as we vary the control parameters. Crises between the attractors and their boundaries are observed. We found that the multiple attractors are intertwined, and when the boundary crisis between their stable and unstable manifolds occurs, it creates a successive mechanism of destruction for all attractors originated by the sinks. Also, a physical impact crisis is described, an important mechanism in the reduction of the number of attractors.

Force-free field model of ball lightning

International Nuclear Information System (INIS)

Tsui, K.H.

2001-01-01

Due to the nature that the force-free magnetic field, whose current carried by the conducting plasma is everywhere parallel to the magnetic field it generates, is the minimum energy configuration under the constraint of magnetic helicity conservation, ball lightning is considered as a self-organized phenomenon with a plasma fireball immersed in a spherical force-free magnetic field. Since this field does not exert force on the plasma, the plasma pressure, by itself, is in equilibrium with the surrounding environment, and the force-free magnetic field can take on any value without affecting the plasma. Due to this second feature, singular solutions of the magnetic field that are otherwise excluded are allowed, which enable a large amount of energy to be stored to sustain the ball lightning. The singularity is truncated only by the physical limit of current density that a plasma can carry. Scaling the customary soccer-size fireball to larger dimensions could account for day and night sightings of luminous objects in the sky

Gap junctions are selectively associated with interlocking ball-and-sockets but not protrusions in the lens.

Science.gov (United States)

Biswas, Sondip K; Lee, Jai Eun; Brako, Lawrence; Jiang, Jean X; Lo, Woo-Kuen

2010-11-09

Ball-and-sockets and protrusions are specialized interlocking membrane domains between lens fibers of all species studied. Ball-and-sockets and protrusions are similar in their shape, size, and surface morphology, and are traditionally believed to play a key role in maintaining fiber-to-fiber stability. Here, we evaluate the hypothesis that ball-and-sockets and protrusions possess important structural and functional differences during fiber cell differentiation and maturation. Intact lenses of leghorn chickens (E7 days to P62 weeks old) and rhesus monkeys (1.5-20 years old) were studied with SEM, freeze-fracture TEM, freeze-fracture immunogold labeling (FRIL), and filipin cytochemistry for membrane cholesterol detection. SEM showed that ball-and-sockets were distributed along the long and short sides of hexagonal fiber cells, whereas protrusions were located along the cell corners, from superficial to deep cortical regions in both chicken and monkey lenses. Importantly, by freeze-fracture TEM, we discovered the selective association of gap junctions with all ball-and-sockets examined, but not with protrusions, in both species. In the embryonic chicken lens (E18), the abundant distribution of ball-and-socket gap junctions was regularly found in an approximate zone extending at least 300 μm deep from the equatorial surface of the superficial cortical fibers. Many ball-and-socket gap junctions often protruded deeply into neighboring cells. However, in the mature fibers of monkey lenses, several ball-and-sockets exhibited only partial occupancy of gap junctions with disorganized connexons, possibly due to degradation of gap junctions during fiber maturation and aging. FRIL analysis confirmed that both connexin46 (Cx46) and connexin50 (Cx50) antibodies specifically labeled ball-and-socket gap junctions, but not protrusions. Furthermore, filipin cytochemistry revealed that the ball-and-socket gap junctions contained different amounts of cholesterol (i.e., cholesterol

Coal ball formation and a soil extinction near the P-Tr boundary

Science.gov (United States)

Breecker, D.; Royer, D. L.

2017-12-01

Coal balls are calcium carbonate accumulations that commonly permineralize paleotropical PermoCarboniferous coal deposits and preserve exceptional specimens of the coal swamp flora. A widely applicable model for the origin of coal balls is lacking despite the study of these deposits for over a century. Two characteristics of coal balls have been particularly challenging to explain: 1) their temporal range is restricted to the PermoCarboniferous and 2) their typical oxygen isotope and elemental compositions paradoxically indicate freshwater and marine origins, respectively. We propose a new model for coal ball formation. The first step in our model is the episodic delivery of seawater and marine carbonate sediment to coastal mires. Next, these waters are diluted by freshwater and the carbonates dissolve at the elevated pCO2 of the mire subsurface. Finally, as waters flow laterally through stands of arborescent lycopsids, aqueous CO2 in the pore spaces of the peat escapes by diffusion through the air-filled lycopsid rootlets into the overlying water column, where some rootlets are thought to have extended. The CO2 escape drives calcite precipitation in the soil zone. This model explains the narrow temporal occurrence of coal balls, which coincides with the peak diversity of arborescent lycopsids. It also resolves the geochemical conundrum; dilution by freshwater can result in relatively low pore water δ18O values without preventing high-Mg calcite formation. Furthermore, we show mathematically that for published densities of arborescent lycopsid root mats and for reasonable rates of lateral water flow and vertical peat accumulation, CO2 could escape rapidly enough through the rootlets to fill >35% of the porosity with calcite before substantial burial (top several decimeters of peat), explaining the exceptional preservation of coal swamp flora. Therefore, we suggest that coal balls are pedogenic in origin and that their disappearance from the rock record represents

A plasma ball in the Microcosm museum

CERN Multimedia

Maximilien Brice

2005-01-01

Plasma balls, like the one shown here, are displayed in the Microcosm exhibition where families can visit to learn more about the experiments carried out in a research institute like CERN. Hands-on activities allow visitors to get a step closer to the research activities carried out at CERN.

LOW COMPRESSION TENNIS BALLS AND SKILL DEVELOPMENT

Directory of Open Access Journals (Sweden)

John Hammond

2006-12-01

Full Text Available Coaching aims to improve player performance and coaches have a number of coaching methods and strategies they use to enhance this process. If new methods and ideas can be determined to improve player performance they will change coaching practices and processes. This study investigated the effects of using low compression balls (LCBs during coaching sessions with beginning tennis players. In order to assess the effectiveness of LCBs on skill learning the study employed a quasi-experimental design supported by qualitative and descriptive data. Beginner tennis players took part in coaching sessions, one group using the LCBs while the other group used standard tennis balls. Both groups were administered a skills at the beginning of a series of coaching sessions and again at the end. A statistical investigation of the difference between pre and post-test results was carried out to determine the effect of LCBs on skill learning. Additional qualitative data was obtained through interviews, video capture and the use of performance analysis of typical coaching sessions for each group. The skill test results indicated no difference in skill learning when comparing beginners using the LCBs to those using the standard balls. Coaches reported that the LCBs appeared to have a positive effect on technique development, including aspects of technique that are related to improving power of the shot. Additional benefits were that rallies went on longer and more opportunity for positive reinforcement. In order to provide a more conclusive answer to the effects of LCBs on skill learning and technique development recommendations for future research were established including a more controlled experimental environment and larger sample sizes across a longer period of time

Ball lightning as a spherical plasma configuration of relevance to industrial plasma engineering

International Nuclear Information System (INIS)

Roth, J.R.

1992-01-01

One of the most interesting spherical plasma configurations found in nature is ball lightning, which has been extensively observed in atmospheric air, usually in association with thunderstorms. If the physical processes responsible for ball lightning were understood, this knowledge would have very interesting implications not only for fusion research, but also for industrial plasma engineering. The ability to create a steady-state atmospheric glow discharge would allow many surface modification and other plasma processing applications to be carried out under atmospheric conditions, rather than in expensive vacuum systems which enforce batch processing operations. The existence of ball lightning offers encouragement for the belief that a steady-state atmospheric glow discharge may be possible. Much progress has been made in theoretical attempts to understand ball lightning, perhaps the most comprehensive of which is the Koloc model. This and related models have not satisfactorily dealt with the long plasma lifetimes in the face of electron scattering at atmospheric density. This leads to an unsatisfactory aspect of the Koloc model, the requirement of a shell of relativistic electrons with very low Coulomb scattering cross sections. This last major conceptual roadblock in understanding ball lightning may have been removed by the recent suggestion of Witalis who pointed out that atmospheric gases, or their products, can exhibit the Ramsauer effect, extremely low electron scattering cross sections at low electron kinetic temperatures, on the order of one eV. This recent progress in ball lightning models has stimulated research aimed at producing a steady state glow discharge in air at atmospheric pressure. Such a glow discharge in argon with a few ppm of acetone has been reported by Kanda, et al. At the UTK Plasma Science Laboratory, the authors have generated at 2.8 liter plasma in a steady-state atmospheric pressure glow discharge in helium and other gases

Catching what we can't see: manual interception of occluded fly-ball trajectories.

Science.gov (United States)

Bosco, Gianfranco; Delle Monache, Sergio; Lacquaniti, Francesco

2012-01-01

Control of interceptive actions may involve fine interplay between feedback-based and predictive mechanisms. These processes rely heavily on target motion information available when the target is visible. However, short-term visual memory signals as well as implicit knowledge about the environment may also contribute to elaborate a predictive representation of the target trajectory, especially when visual feedback is partially unavailable because other objects occlude the visual target. To determine how different processes and information sources are integrated in the control of the interceptive action, we manipulated a computer-generated visual environment representing a baseball game. Twenty-four subjects intercepted fly-ball trajectories by moving a mouse cursor and by indicating the interception with a button press. In two separate sessions, fly-ball trajectories were either fully visible or occluded for 750, 1000 or 1250 ms before ball landing. Natural ball motion was perturbed during the descending trajectory with effects of either weightlessness (0 g) or increased gravity (2 g) at times such that, for occluded trajectories, 500 ms of perturbed motion were visible before ball disappearance. To examine the contribution of previous visual experience with the perturbed trajectories to the interception of invisible targets, the order of visible and occluded sessions was permuted among subjects. Under these experimental conditions, we showed that, with fully visible targets, subjects combined servo-control and predictive strategies. Instead, when intercepting occluded targets, subjects relied mostly on predictive mechanisms based, however, on different type of information depending on previous visual experience. In fact, subjects without prior experience of the perturbed trajectories showed interceptive errors consistent with predictive estimates of the ball trajectory based on a-priori knowledge of gravity. Conversely, the interceptive responses of subjects

Effect of Kinesiotape Applications on Ball Velocity and Accuracy in Amateur Soccer and Handball.

Science.gov (United States)

Müller, Carsten; Brandes, Mirko

2015-12-22

Evidence supporting performance enhancing effects of kinesiotape in sports is missing. The aims of this study were to evaluate effects of kinesiotape applications with regard to shooting and throwing performance in 26 amateur soccer and 32 handball players, and to further investigate if these effects were influenced by the players' level of performance. Ball speed as the primary outcome and accuracy of soccer kicks and handball throws were analyzed with and without kinesiotape by means of radar units and video recordings. The application of kinesiotapes significantly increased ball speed in soccer by 1.4 km/h (p=0.047) and accuracy with a lesser distance from the target by -6.9 cm (p=0.039). Ball velocity in handball throws also significantly increased by 1.2 km/h (p=0.013), while accuracy was deteriorated with a greater distance from the target by 3.4 cm (p=0.005). Larger effects with respect to ball speed were found in players with a lower performance level in kicking (1.7 km/h, p=0.028) and throwing (1.8 km/h, p=0.001) compared with higher level soccer and handball players (1.2 km/h, p=0.346 and 0.5 km/h, p=0.511, respectively). In conclusion, the applications of kinesiotape used in this study might have beneficial effects on performance in amateur soccer, but the gain in ball speed in handball is counteracted by a significant deterioration of accuracy. Subgroup analyses indicate that kinesiotape may yield larger effects on ball velocity in athletes with lower kicking and throwing skills.

Some results on rotating fluid balls of Petrov type D

Energy Technology Data Exchange (ETDEWEB)

Bradley, M [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Eriksson, D [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Fodor, G [KFKI Research Institute for Particle and Nuclear Physics, H-1525, Budapest 114, P.O.B. 49 (Hungary); Racz, I [KFKI Research Institute for Particle and Nuclear Physics, H-1525, Budapest 114, P.O.B. 49 (Hungary)

2007-05-15

The second order perturbative field equations for slowly and rigidly rotating perfect fluid balls of Petrov type D are solved numerically. It is found that all the slowly and rigidly rotating perfect fluid balls up to second order, irrespective of Petrov type, may be matched to a possibly non-asymptotically flat stationary axisymmetric vacuum exterior. A subspace of the parameter space is identified for which the solutions can be matched to an asymptotically flat exterior vacuum region. The physical properties like equations of state, shapes and speeds of sound are determined for a number of solutions.

Note: A 1-m Foucault pendulum rolling on a ball

Science.gov (United States)

Salva, H. R.; Benavides, R. E.; Venturino, J. A.; Cuscueta, D. J.; Ghilarducci, A. A.

2013-10-01

We have built a short Foucault pendulum of 1-m length. The aim of this work was to increase the sensitivity to elliptical trajectories from other longer pendula. The design was a semi-rigid pendulum that rolls over a small ball. The measurements of the movements (azimuth and elliptical trajectory) were done by an optical method. The resulting pendulum works in a medium satisfactory way due to problems of the correct choice of the mass of the bob together with the diameter of the supporting ball. It is also important to keep the rolling surface very clean.

Micro sized implantable ball lens-based fiber optic probe design

Science.gov (United States)

Cha, Jaepyeong; Kang, Jin U.

2014-02-01

A micro sized implantable ball lens-based fiber optic probe design is described for continuous monitoring of brain activity in freely behaving mice. A prototype uses a 500-micron ball lens and a highly flexible 350-micron-diameter fiber bundle, which are enclosed by a 21G stainless steel sheath. Several types and thickness of brain tissue, consisting of fluorescent probes such as GFP, GCaMP3 calcium indicator, are used to evaluate the performance of the imaging probe. Measured working distance is approximately 400-μm, but is long enough to detect neural activities from cortical and cerebellar tissues of mice brain.

The joy at the Last Judgement according to the Heidelberg Catechism Question 52

Directory of Open Access Journals (Sweden)

Eberhard Busch

2014-12-01

Full Text Available In this contribution, the author reflects on Question 52 of the Heidelberg Catechism where it asks: ‘What comfort is it to you that Christ “shall come to judge the living and the dead”?’ The author points out possible sources from which this formulation stems, that is, Articles 86 and 87 in John Calvin’s Catechism from 1545. God is described as a compassionate judge. Even more: the One who is the last judge, was also judged and had paid for our sins. In a dialectical fashion we discover a God who is just, but also merciful. The Reformed tradition did not follow a dead-end where it is taught that God shows us grace instead of righteousness. Had God proceeded in this way, he would only mean things well, but he would not make them well. The realisation of God being just and merciful leads to joy and repentance. The contribution ends with a discussion of the final separation of the just and evil.

Gas-Liquid Transition in a Two-Dimensional System of Millimeter-Sized Like-Charged Metal Balls

International Nuclear Information System (INIS)

Tata, B. V. R.; Rajamani, P. V.; Chakrabarti, J.; Nikolov, Alex; Wasan, D. T.

2000-01-01

Metal balls with a diameter of 1.59 mm, gently rubbed against a dielectric surface using a shaker, are seen to spontaneously exhibit a two-dimensional liquidlike order with macroscopic dimensions, viz., interball distances of several millimeters. This liquidlike order transforms to a gaslike order through coexistence upon decreasing the area fraction of the balls. The measured pair interaction of like-charged balls surprisingly exhibits a long-range attractive term analogous to that in charged colloids. (c) 2000 The American Physical Society

Reversible a-Fe2O3 to Fe3O4 transformation during ball milling

DEFF Research Database (Denmark)

Linderoth, Søren; Jiang, Jianzhong; Mørup, Steen

1997-01-01

The transformation of hematite to magnetite by high-energy ball milling in a sealed container has been studied by Mossbauer spectroscopy and x-ray diffraction. Mechanisms for this transformation are critically discussed. The dominant mechanism is concluded to be due to bond breaking during the high...... energy ball milling followed by release of the oxygen from the vial. The reverse transformation, magnetite to hematite, is demonstrated to occur by ball milling in air. Mechanisms for this reverse transformation are also put forward....

O herói na forma e no conteúdo: análise textual do Mangá Dragon Ball e Dragon Ball Z.

OpenAIRE

Silva, André Luiz Souza da

2006-01-01

A presente dissertação, intitulada O herói na forma e no conteúdo: análise textual do mangá Dragon Ball e Dragon Ball Z, objetiva averiguar os aspectos narrativos que compõem o mangá ao longo dessa série, verificando o papel do herói e a sua relação com os demais personagens. Para isso, a investigação analisa os aspectos plásticos do herói no contexto da economia narrativa geral dos quadrinhos. O objetivo é ponderar e realçar certos aspectos de ordem morfológica e das ações narrativas entre o...

Experimental Analysis of Damping and Tribological Characteristics of Nano-CuO Particle Mixed Lubricant in Ball Bearings

Science.gov (United States)

Prakash, E.; Sivakumar, K.

2015-12-01

Experimental analysis of damping capacity and tribological characteristics of nano CuO added Servosystem 68 lubricant is attempted. CuO nano particles were synthesized by aqueous precipitation method and characterized. Prior to dispersion into lubricant, CuO nano particles were coated with 0.2 wt.% surfactant (Span-80) to stabilize the nano fluid. Tribological characteristics of particle added lubricant were tested in ASTM D 4172 four ball wear tester. Scanning electron microscopy test results of worn surfaces of nano CuO particle added lubricant were smoother than base lubricant. The particle added lubricant was applied in a new ball bearing and three defected ball bearings. When particle added lubricant was used, the ball defected bearing's vibration amplitude was reduced by 21.94% whereas it was 16.46% for new bearing and was ≤ 11% for other defected bearings. The formation of protection film of CuO over ball surface and regime of full film lubrication near the ball zone were observed to be reason for improved damping of vibrations.

Standard Test Method for Determining Resistance of Photovoltaic Modules to Hail by Impact with Propelled Ice Balls

CERN Document Server

American Society for Testing and Materials. Philadelphia

2010-01-01

1.1 This test method provides a procedure for determining the ability of photovoltaic modules to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. 1.2 This test method defines test specimens and methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, provides a method for determining changes in electrical performance, and specifies parameters that must be recorded and reported. 1.3 This test method does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice ball impact resistance is beyond the scope of this test method. 1.4 The size of the ice ball to be used in conducting this test is not specified. This test method can be used with various sizes of ice balls. 1.5 This test method may be applied to concentrator and nonconcentrator modules. 1.6 The v...

Standard Practice for Determining Resistance of Solar Collector Covers to Hail by Impact With Propelled Ice Balls

CERN Document Server

American Society for Testing and Materials. Philadelphia

1992-01-01

1.1 This practice covers a procedure for determining the ability of cover plates for flat-plate solar collectors to withstand impact forces of falling hail. Propelled ice balls are used to simulate falling hailstones. This practice is not intended to apply to photovoltaic cells or arrays. 1.2 This practice defines two types of test specimens, describes methods for mounting specimens, specifies impact locations on each test specimen, provides an equation for determining the velocity of any size ice ball, provides a method for impacting the test specimens with ice balls, and specifies parameters that must be recorded and reported. 1.3 This practice does not establish pass or fail levels. The determination of acceptable or unacceptable levels of ice-ball impact resistance is beyond the scope of this practice. 1.4 The size of ice ball to be used in conducting this test is not specified in this practice. This practice can be used with various sizes of ice balls. 1.5 The categories of solar collector cover plat...

Development of Uranium-Carrying Ball method for calibration of fuel element failure detecting systems

International Nuclear Information System (INIS)

Liu Yupu; Bao Wanping; Lu Cungang

1988-01-01

A Uranium-Carrying Ball method used for the determination of sensitivity, stability of the fuel element failure detecting systems is developed. A special facility for transporting the ball can be carried out by the flow of the cooling water, so that the failure signal can be simulated. Five different types of the Uranium-Carrying Ball have been developed. Type-I to Type-IV may provide failure signal in terms of uranium quantity or exposure area of uranium. Type-V can be used to simulate micro-flaw and examine the detectability of various detective methods for this kind of defect, at the same time it is difficult for the delayed neutron detector to detect micro-flaw. The results of long-time irradiation and washing test show that the working life of the balls is satisfactory. Using the experimentel facility with the balls, detailed study of the capability of various fuel failure detecting systems have been conducted successfully. The operation is easy and safe, the accuracy of this method is higher than that of other methods, the nuclear fuel consumption as well as the radioactive contamination is low. At present, the research on the failure mechanism is being conducted by means of this method

Effects of the Horse Riding Simulator and Ball Exercises on Balance of the Elderly

Science.gov (United States)

Kim, SeongGil; Yuk, Goon-chang; Gak, Hwangbo

2013-01-01

[Purpose] The aim of this study was to examine the effects of horse riding exercise using a horse riding simulator (HRS) and a ball on static and dynamic balance of elderly people. [Methods] Thirty-two elderly people hospitalized in geriatric hospitals were randomly assigned to the HRS exercise group or the ball exercise groups, and they performed exercise for eight weeks. [Results] The length of postural sway during quite standing with and without eyes closed significantly decreased in both groups after the exercises and there was no significant difference between both groups in the Romberg test. In the functional reach test (FRT), there were significant increases in distance in both groups after the exercises, and the distance of the HRS exercise group was significantly greater than that of the ball exercise group. In the Timed Up & Go test (TUG) and Timed 10-meter walk test (10MWT), the time significantly decreased in both groups, and there was a more significant decrease in the HRS exercise group than in the ball exercise group. [Conclusion] The results of this study indicate that HRS and ball exercises may improve the balance and gait ability of elderly people hospitalized in nursing homes or geriatric hospitals. PMID:24396203

Temperature Measurements of the Low-Attenuation Radiographic Ice Ball During CT-Guided Renal Cryoablation

International Nuclear Information System (INIS)

Permpongkosol, Sompol; Link, Richard E.; Kavoussi, Louis R.; Solomon, Stephen B.

2008-01-01

During renal cryoablation a low-attenuation area on CT develops around the cryoprobe. Knowledge of the temperature of the growing low-attenuation area can guide therapy and ensure lethal temperatures. Herein, we report thermocouple results and correlating CT images during the development of the low-attenuation 'radiographic ice ball.' Five patients who underwent percutaneous CT-guided renal cryoablation were identified who had thermocouples inserted and serial intraprocedural CT images that included images with thermocouple measurements of 0 o and sub-0 o C. Thermocouples had been percutaneously placed just beyond the edge of the tumors either to ensure adequate cooling or to ensure safety to adjacent critical structures. Renal cryotherapy under CT guidance produced a growing low-attenuation area corresponding to the radiographic ice ball. When the thermocouple measured 0 o C, CT images showed the thermocouple tip at the edge of the low-attenuation ice ball. At lower temperatures the tip was within the low-attenuation ice ball. We conclude that knowledge of the temperature at the ice ball edge during cryoablation can be used to predict the extent of tissue necrosis and thus provide an estimate of cryotherapy effectiveness during the procedure. Further work is necessary to establish a firm relationship between the thermal conditions and the zone of damage

Performance Study of Graphite Anode Slurry in Lithium-ion Flow Battery by Ball Milling

Directory of Open Access Journals (Sweden)

FENG Cai-mei

2018-02-01

Full Text Available Graphite anode slurry of lithium-ion flow battery was prepared by the method of ball milling. The morphology, conductivity, specific capacity and cycle performance of graphite anode slurry were studied. Results show that the addition of conductive carbon material can improve the suspension stability of the electrode slurry; the ball milling process can not only improve the suspension stability but also reduce the resistivity of the mixed powders of graphite and conductive carbon materials, the ball milling effect is satisfactory when the mass ratio of the balls and the solid particles is 5:1, but too high ratio of the milling ball and the solid materials can destroy the layer structure of the graphite and affect the stability of the slurry. Increasing the fraction of the graphite and conductive carbon materials can form stable electrical network structure in the slurry and improve the reversible capacity; at the premise of keeping the flowability of the electrode slurry, the reversible specific capacity can be more than 40mAh/g. The capacity loss of graphite anode slurry mainly occurs in the first charging-discharging process, as the increase of the cycles, the capacity loss rate decreases, the capacity goes stable after 5 cycles.

Ball-thrower's fracture of the humerus

International Nuclear Information System (INIS)

Callaghan, Eric B.; Bennett, D. Lee; El-Khoury, Georges Y.; Ohashi, Kenjirou

2004-01-01

A relatively rare case of ball-thrower's fracture of the humerus is presented. Severe muscular action is an uncommon cause of humeral fractures but has been well documented in the orthopedic literature. To our knowledge, this fracture has not been described in the radiology literature, and awareness of this entity could preclude further unnecessary workup. The mechanism of injury and its typical radiographic appearance is described. (orig.)

Anthropometric, biomechanical, and isokinetic strength predictors of ball release speed in high-performance cricket fast bowlers.

Science.gov (United States)

Wormgoor, Shohn; Harden, Lois; Mckinon, Warrick

2010-07-01

Fast bowling is fundamental to all forms of cricket. The purpose of this study was to identify parameters that contribute to high ball release speeds in cricket fast bowlers. We assessed anthropometric dimensions, concentric and eccentric isokinetic strength of selected knee and shoulder muscle groups, and specific aspects of technique from a single delivery in 28 high-performance fast bowlers (age 22.0 +/- 3.0 years, ball release speed 34.0 +/- 1.3 m s(-1)). Six 50-Hz cameras and the Ariel Performance Analysis System software were used to analyse the fast and accurate deliveries. Using Pearson's correlation, parameters that showed significant associations with ball release speed were identified. The findings suggest that greater front leg knee extension at ball release (r=0.52), shoulder alignment in the transverse plane rotated further away from the batsman at front foot strike (r=0.47), greater ankle height during the delivery stride (r=0.44), and greater shoulder extension strength (r=0.39) contribute significantly to higher ball release speeds. Predictor variables failed to allow their incorporation into a multivariate model, which is known to exist in less accomplished bowlers, suggesting that factors that determine ball release speed found in other groups may not apply to high-performance fast bowlers.

Replacing by numbers - computer aided installation of ball screws in a CANDU

International Nuclear Information System (INIS)

Granz, R.; Georgas, J.

1992-01-01

Performing repair procedures on a commissioned nuclear reactor is a critical maintenance task and certainly not one suitable for on-the-job experimentation. That was our dilemma when the engineering staff developed what was thought would be a better way to replace the ball screws in the fuelling machine support bridges of a CANDU nuclear plant. The 40ft long ball screws must be installed vertically into square cavities that are less than 40ft from the ''ceiling'' of the room where they are located. Standard operating procedures for replacing the ball screw involve opening up the feeder cabinet located above to provide clearance. But this practice risks damage to delicate piping located inside the cabinet. The new concept involved walking the ball screw in by tilting it at a series of angles. Unfortunately, there was no simple way that we could determine with pencil and paper whether or not this approach would work or exactly how to do it in practice. Using the solid modelling capabilities of the Aries Concept Station mechanical computer-aided engineering system, we proved the new procedure and developed a series of illustrations offering step-by-step visual instructions to guide the maintenance crew performing the task. (Author)

Heel–Ball index: An analysis of footprint dimensions for determination of sex

Directory of Open Access Journals (Sweden)

Tanuj Kanchan

2014-06-01

Full Text Available Determination of sex from the footprints recovered at crime scenes can help the investigation by narrowing down the pool of possible suspects. The present research studies the dimensions of the heel and the ball in footprints, and derives the Heel–Ball (HB index from these foot dimensions with the aim to find out if the foot dimensions and the HB index exhibit sexual dimorphisms. The study was carried out on 100 individuals (50 males, 50 females of Indian origin. Footprints were obtained from both feet of the study participants using standard techniques. Thus, a total of 200 footprints were obtained. The breadth of the footprint at ball (BBAL and the breadth of the footprint at heel (BHEL were measured on the footprints. The HB index was derived as (BHEL ÷ BBAL × 100. The footprint measurements at the ball and heel were significantly larger in males on both the sides. Likewise, the derived HB index was larger in males in both feet, but the sex differences were not statistically significant. The study concludes that though footprint dimensions can be used in the determination of sex, the HB index may not be utilized in sex determination from footprints.

Acquisition and reduction of data obtained from tank 101-SY in-situ ball rheometer

International Nuclear Information System (INIS)

Shepard, C.L.; Chieda, M.A.; Kirihara, L.J.; Phillips, J.R.; Shekarriz, A.; Terrones, G.; Abbott, J.; Unal, C.; Pasamehmetoglu, K.O.; Graham, A.

1995-02-01

Development of the ball rheometer to measure rheological properties and density of the waste in Hanford Tank 241-SY-101 will be completed around September 1994. This instrument is expected to provide the first-of-its-kind in-situ measurements of the fluid properties of the waste contained within this tank. A mixer pump has been installed in this tank, and this pump has been very successful at mitigating the flammable gas problem associated with Tank 101-SY. The ball rheometer will serve as a diagnostic tool for judging the effectiveness of mixing in Tank 101-SY and others and will be one of few in-situ probes available for diagnostic measurements. Based on experiments performed at Los Alamos National Laboratory and Pacific Northwest Laboratory, it is believed that a generalized Bingham fluid model (Herschel-Bulkley fluid model) may be useful for describing at least some of the waste contained in Tank 101-SY, and data obtained in the tank will initially be reduced using this fluid model. The single largest uncertainty in the determination of the drag force on the ball is the drag force which will be experienced by the cable attached to the ball. This drag can be a substantial fraction of the total drag when the ball is deep within the tank. It is expected that the fluid properties may be history dependent, thus rheological properties of the undisturbed fluid may be different from the same properties after the fluid has been disturbed by passage of the ball. The data collection strategy allows the determination of the waste fluid rheology both in the undisturbed state and after it has been disturbed by the ball. Unlike the rheological parameters, measurement of density requires no model for its interpretation; however, the effects of yield stress may need to be accounted for. This measurement can be made with fairly good accuracy and may provide the most useful data in determination of mixer pump effectiveness

Searching for axion stars and Q-balls with a terrestrial magnetometer network

Energy Technology Data Exchange (ETDEWEB)

Jackson Kimball, D. F. [Cal State, East Bay; Budker, D. [UC, Berkeley; Eby, J. [Fermilab; Pospelov, M. [Perimeter Inst. Theor. Phys.; Pustelny, S. [Jagiellonian U.; Scholtes, T. [Fribourg U.; Stadnik, Y. V. [Helmholtz Inst., Mainz; Weis, A. [Fribourg U.; Wickenbrock, A. [Mainz U.

2017-10-11

Light (pseudo-)scalar fields are promising candidates to be the dark matter in the Universe. Under certain initial conditions in the early Universe and/or with certain types of self-interactions, they can form compact dark-matter objects such as axion stars or Q-balls. Direct encounters with such objects can be searched for by using a global network of atomic magnetometers. It is shown that for a range of masses and radii not ruled out by existing observations, the terrestrial encounter rate with axion stars or Q-balls can be sufficiently high (at least once per year) for a detection. Furthermore, it is shown that a global network of atomic magnetometers is sufficiently sensitive to pseudoscalar couplings to atomic spins so that a transit through an axion star or Q-ball could be detected over a broad range of unexplored parameter space.

Moment of Inertia of a Ping-Pong Ball

Science.gov (United States)

Cao, Xian-Sheng

2012-01-01

This note describes how to theoretically calculate and experimentally measure the moment of inertia of a Ping-Pong[R] ball. The theoretical calculation results are in good agreement with the experimental measurements that can be reproduced in an introductory physics laboratory.

Axino dark matter and baryon number asymmetry production by the Q-ball decay in gauge mediation

Energy Technology Data Exchange (ETDEWEB)

Kasuya, Shinta [Department of Mathematics and Physics, Kanagawa University, Kanagawa 259-1293 (Japan); Kawakami, Etsuko; Kawasaki, Masahiro, E-mail: kasuya@kanagawa-u.ac.jp, E-mail: kwkm@icrr.u-tokyo.ac.jp, E-mail: kawasaki@icrr.u-tokyo.ac.jp [Institute for Cosmic Ray Research, University of Tokyo, Chiba 277-8582 (Japan)

2016-03-01

We investigate the Q-ball decay into the axino dark matter in the gauge-mediated supersymmetry breaking. In our scenario, the Q ball decays mainly into nucleons and partially into axinos to account respectively for the baryon asymmetry and the dark matter of the universe. The Q ball decays well before the big bang nucleosynthesis so that it is not affected by the decay. We show the region of the parameters which realizes this scenario.

76 FR 41761 - Ball Bearings and Parts Thereof From Japan and the United Kingdom: Revocation of Antidumping Duty...

Science.gov (United States)

2011-07-15

... DEPARTMENT OF COMMERCE International Trade Administration [A-588-804, A-412-801] Ball Bearings and... Commerce (the Department) is revoking the antidumping duty orders on ball bearings and parts thereof from...: Background On May 15, 1989, the Department published the antidumping duty orders on ball bearings and parts...

Analysis of a spacecraft instrument ball bearing assembly lubricated by a perfluoroalkylether

Science.gov (United States)

Morales, W.; Jones, W. R., Jr.; Buckley, D. H.

1986-01-01

An analysis of a spacecraft instrument ball bearing assembly, subjected to a scanning life test, was performed to determine the possible case of rotational problems involving these units aboard several satellites. The analysis indicated an ineffective transfer of a fluorinated liquid lubricant from a phenolic retainer to the bearing balls. Part of the analysis led to a novel HPLC separation method employing a fluorinated mobile phase in conjunction with silica based size exclusion columns.

Analysis of grease contamination influence on the internal radial clearance of ball bearings by thermographic inspection

Directory of Open Access Journals (Sweden)

Mišković Žarko Z.

2016-01-01

Full Text Available One of the most important factors influencing ball bearings service life is its internal radial clearance. However, this parameter is also very complex because it depends on applied radial load and ball bearings dimensions, surface finish and manufacturing materials. Thermal condition of ball bearings also significantly affects internal radial clearance. Despite many researches performed in order to find out relevant facts about different aspects of ball bearings thermal behaviour, only few of them are dealing with the real working conditions, where high concentration of solid contaminant particles is present. That’s why the main goal of research presented in this paper was to establish statistically significant correlation between ball bearings temperatures, their working time and concentration of contaminant particles in their grease. Because of especially difficult working conditions, the typical conveyor idlers bearings were selected as representative test samples and appropriate solid particles from open pit coal mines were used as artificial contaminants. Applied experimental methodology included thermographic inspection, as well as usage of custom designed test rig for ball bearings service life testing. Finally, by obtained experimental data processing in advanced software, statistically significant mathematical correlation between mentioned bearings characteristics was determined and applied in commonly used internal radial clearance equation. That is the most important contribution of performed research - the new equation and methodology for ball bearings internal clearance determination which could be used for eventual improvement of existing bearings service life equations. [Projekat Ministarstva nauke Republike Srbije, br. TR35029 i br. TR14033

Entanglement and the three-dimensionality of the Bloch ball

Energy Technology Data Exchange (ETDEWEB)

Masanes, Ll., E-mail: ll.masanes@gmail.com [Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT (United Kingdom); Müller, M. P. [Institut für Theoretische Physik, Universität Heidelberg, Philosophenweg 19, D-69120 Heidelberg (Germany); Pérez-García, D. [Departamento de Analisis Matematico and IMI, Universidad Complutense de Madrid, 28040 Madrid (Spain); Augusiak, R. [ICFO-Institut de Ciencies Fotoniques, 08860 Castelldefels, Barcelona (Spain)

2014-12-15

We consider a very natural generalization of quantum theory by letting the dimension of the Bloch ball be not necessarily three. We analyze bipartite state spaces where each of the components has a d-dimensional Euclidean ball as state space. In addition to this, we impose two very natural assumptions: the continuity and reversibility of dynamics and the possibility of characterizing bipartite states by local measurements. We classify all these bipartite state spaces and prove that, except for the quantum two-qubit state space, none of them contains entangled states. Equivalently, in any of these non-quantum theories, interacting dynamics is impossible. This result reveals that “existence of entanglement” is the requirement with minimal logical content which singles out quantum theory from our family of theories.

Sir Robert Ball: Victorian Astronomer and Lecturer par excellence

Science.gov (United States)

Jones, R. I. G.

2005-12-01

Between 1875 and 1910 Sir Robert Stawell Ball gave an estimated 2,500 lectures in towns and cities all over the British Isles and abroad. This paper traces his lecturing career from its beginnings in Ireland to the triumphs of the Royal Institution, and on lecture tours in the United States of America. After a period in mathematics and mechanics, he became a populariser of science, especially astronomy, and found fame and fortune among the working classes and the aristocracy. What motivated him to tireless travels is uncertain, but it might have been that it was rewarding, financially and to his reputation. Whatever his motives, contemporary accounts are clear that BallÕs lectures were extremely popular and well-received.

Electrochemical properties of the ball-milled LaMg10NiMn alloy with Ni powders

International Nuclear Information System (INIS)

Wang Yi; Wang Xin; Gao Xueping; Shen Panwen

2008-01-01

The electrochemical characteristics of the ball-milled LaMg 10 NiMn alloys with Ni powders were investigated. It was found that the ball-milled LaMg 10 NiMn + 150 wt.% Ni composite exhibited higher first discharge capacity and better cycle performance. By means of the analysis of electrochemical impedance spectra (EIS), it was shown that the existence of manganese in LaMg 10 NiMn alloy increased the electrocatalytic activity due to its catalytic effect, and destabilized metal hydrides, and so reduced the hydrogen diffusion resistance. These contributed to the higher discharge capacity of the ball-milled LaMg 10 NiMn-Ni composite. According to the analytical results of X-ray diffraction (XRD), EIS and steady-state polarization (SSP) experiments, the inhibition of metal corrosion is not the main reason for the better cycle performance. The main reason is that the electrochemical reaction resistance of the ball-milled LaMg 10 NiMn-Ni composite is always lower than that of the ball-milled LaMg 10 Ni 2 -Ni composite because the former one contains manganese, which is a catalyst for the electrode reaction

Therapeutical attitudes in tooth supported overdentures with ball attachements. Case report.

Science.gov (United States)

Țâncu, A M; Melescanu Imre, M; Preoteasa, C T; Preoteasa, E

2014-01-01

Tooth supported overdenture with ball attachments has a number of advantages in prosthetics, but presents some difficulties as well, which sometimes make impossible the use of these anchoring systems; these difficulties should be well known. In this regard we present a suggestive case. It is the case of a patient, aged 57, who came for treatment, suffering from subtotal maxillary and mandibular edentulism (present 11 and 21, respectively 33 and 43), previously having an overdenture prosthesis on natural teeth, with special systems - ball attachment type, dissatisfied with the treatment (due to repeated fractures and functional intolerance to dentures). Clinical examination revealed an increase of the vertical dimension of occlusion and reduced prosthetic space at a correct, functional DVO value, aspects that were explaining the patient's reported complaints. As a therapeutic approach, having into consideration the balance conditions that were favorable for complete dentures and the large ball attachments volume, which did not allow keeping them at a functional DVO at any of the jaws, and the relatively young age of the patient, it was decided to remove the ball attachments and to keep the teeth for a simple overdenture, both to the maxillar and the mandible, over coronary reduced teeth, enough to allow the denture thickness at a functional DVO. Good end result of prosthetics, with stable, functional dentures, which were well tolerated and offered satisfaction to the patient, have led to an increased quality of life.

Thermogravimetric and Differential Scanning Calorimetric Behavior of Ball-Milled Nuclear Graphite

Energy Technology Data Exchange (ETDEWEB)

Kim, Eung Seon; Kim, Min Hwan; Kim, Yong Wan [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of); Park, Yi Hyun; Cho, Seung Yon [National Fusion Research Institute, Daejeon (Korea, Republic of)

2013-10-15

An examination was made to characterize the oxidation behavior of ball-milled nuclear graphite powder through a TG-DSC analysis. With the ball milling time, the BET surface area increased with the reduction of particle size, but decreased with the chemisorptions of O{sub 2} on the activated surface. The enhancement of the oxidation after the ball milling is attributed to both increases in the specific surface area and atomic scale defects in the graphite structure. In a high temperature gas-cooled reactor, nuclear graphite has been widely used as fuel elements, moderator or reflector blocks, and core support structures owing to its excellent moderating power, mechanical properties and machinability. For the same reason, it will be used in a helium cooled ceramic reflector test blanket module for the ITER. Each submodule has a seven-layer breeding zone, including three neutron multiplier layers packed with beryllium pebbles, three lithium ceramic pebbles packed tritium breeder layers, and a reflector layer packed with 1 mm diameter graphite pebbles to reduce the volume of beryllium. The abrasion of graphite structures owing to relative motion or thermal cycle during operation may produce graphite dust. It is expected that graphite dust will be more oxidative than bulk graphite, and thus the oxidation behavior of graphite dust must be examined to analyze the safety of the reactors during an air ingress accident. In this study, the thermal stability of ball-milled graphite powder was investigated using a simultaneous thermogravimeter-differential scanning calorimeter.

Therapeutical attitudes in tooth supported overdentures with ball attachements. Case report

Science.gov (United States)

Țâncu, AM; Melescanu Imre, M; Preoteasa, CT; Preoteasa, E

2014-01-01

Tooth supported overdenture with ball attachments has a number of advantages in prosthetics, but presents some difficulties as well, which sometimes make impossible the use of these anchoring systems; these difficulties should be well known. In this regard we present a suggestive case. It is the case of a patient, aged 57, who came for treatment, suffering from subtotal maxillary and mandibular edentulism (present 11 and 21, respectively 33 and 43), previously having an overdenture prosthesis on natural teeth, with special systems – ball attachment type, dissatisfied with the treatment (due to repeated fractures and functional intolerance to dentures). Clinical examination revealed an increase of the vertical dimension of occlusion and reduced prosthetic space at a correct, functional DVO value, aspects that were explaining the patient’s reported complaints. As a therapeutic approach, having into consideration the balance conditions that were favorable for complete dentures and the large ball attachments volume, which did not allow keeping them at a functional DVO at any of the jaws, and the relatively young age of the patient, it was decided to remove the ball attachments and to keep the teeth for a simple overdenture, both to the maxillar and the mandible, over coronary reduced teeth, enough to allow the denture thickness at a functional DVO. Good end result of prosthetics, with stable, functional dentures, which were well tolerated and offered satisfaction to the patient, have led to an increased quality of life. PMID:27057258

"We're just targeted as the flock that has HIV": health care experiences of members of the house/ball culture.

Science.gov (United States)

Rowan, Diana; DeSousa, Maysa; Randall, Ethan Makai; White, Chelsea; Holley, Lamont

2014-01-01

The house/ball community is an understudied sub-group of young Black men who have sex with men and transgender persons in urban centers of the United States who affiliate in social structures called houses and gather at elaborate dance and performance events called balls. In Charlotte, North Carolina, 12 house/ball members were interviewed about their experiences with health care providers and their assessment of any barriers to care due to their affiliation with the rather clandestine house/ball sub-culture. Additionally, HIV-specific health care providers were interviewed, to assess their knowledge of the sub-culture. House/ball members reported both positive and negative perceptions of treatment by their health care providers with respect to their house/ball involvement. Some reported feeling stigmatized, especially around HIV status. Results showed that increased knowledge about the house/ball community could improve practitioners' cultural competence, thereby reducing stigma-related barriers to care.

Energy self-sufficient sensory ball screw drive; Energieautarker sensorischer Kugelgewindetrieb

Energy Technology Data Exchange (ETDEWEB)

Bertram, Oliver

2012-07-01

Nowadays the availability of machine tools plays a decisive role in competition to increase in productivity. From state of the art it arises, that ball screw drives are the most abusive component in feed drives because of abrasive wear. Furthermore condition monitoring enables avoiding unplanned machine failure and increasing the availability of the deployed production facility. Thereby the application of additional sensors allows the direct acquisition of wear correlative measurements. To reduce the required effort for integration and increase the robustness, reliability and clarity in industrial environment energy self-sufficient sensor systems can be applied. In this thesis the development and investigation of an energy self-sufficient sensory ball screw drive with direct measurement of wear correlative pretension for condition monitoring application is described. The prototype measures the pretension with force sensors based on strain gauges. The sensor system includes microcontroller-based electronics for signal processing as well as wireless data transmission with ZigBee-standard. A hybrid system assures the energy supply of the sensor system. On the one hand a stepper motor generator produces electrical energy from the motion energy of the ball screw drive. On the other hand an energy buffer based on super caps is reloaded in stationary position by wireless energy transmission. For verification a prototype system is build up. In measurements the sensory and energetic characteristics of the energy self-sufficient sensor systems are analyzed. Moreover, the functionality of the ball screw drive as well as the signal characteristics of the force sensors are examined for different pretensions. In addition, pretension losses due to wear are established in realized endurance trials, which means that timely maintenance can be planned.

Effect of birth ball on labor pain relief: A systematic review and meta-analysis.

Science.gov (United States)

Makvandi, Somayeh; Latifnejad Roudsari, Robab; Sadeghi, Ramin; Karimi, Leila

2015-11-01

To critically evaluate the available evidence related to the impact of using a birth ball on labor pain relief. The Cochrane library, Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE/PubMed and Scopus were searched from their inception to January 2015 using keywords: (Birth* OR Swiss OR Swedish OR balance OR fitness OR gym* OR Pezzi OR sport* OR stability) AND (ball*) AND (labor OR labour OR Obstetric). All available randomized controlled trials involving women using a birth ball for pain relief during labor were considered. The search resulted in 341 titles and abstracts, which were narrowed down to eight potentially relevant articles. Of these, four studies met the inclusion criteria. Pain intensity on a 10 cm visual analogue scale was used as the main outcome measure. Risk of bias was assessed using the Cochrane Risk of Bias tool. Comprehensive Meta-Analysis Version 2 was used for statistical analysis. Four RCTs involving 220 women were included in the systematic review. One study was excluded from the meta-analysis because of heterogeneous interventions and a lack of mean and standard deviation results of labor pain score. The meta-analysis showed that birth ball exercises provided statistically significant improvements to labor pain (pooled mean difference -0.921; 95% confidence interval -1.28, -0.56; P = 0.0000005; I(2)  = 33.7%). The clinical implementation of a birth ball exercise could be an effective tool for parturient women to reduce labor pain. However, rigorous RCTs are needed to evaluate the effect of the birth ball on labor pain relief. © 2015 Japan Society of Obstetrics and Gynecology.

Revisiting the gravitino dark matter and baryon asymmetry from Q-ball decay in gauge mediation

Energy Technology Data Exchange (ETDEWEB)

Kasuya, Shinta, E-mail: kasuya@kanagawa-u.ac.jp [Department of Mathematics and Physics, Kanagawa University, Kanagawa 259-1293 (Japan); Max-Planck-Institut für Kernphysik, PO Box 103980, 69029 Heidelberg (Germany); Kawasaki, Masahiro [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan); Kavli Institute for the Physics and Mathematics of the Universe (WPI), Todai Institutes for Advanced Study, the University of Tokyo, Chiba 277-8582 (Japan); Yamada, Masaki [Institute for Cosmic Ray Research, the University of Tokyo, Chiba 277-8582 (Japan)

2013-10-07

We reconsider the Q-ball decay and reinvestigate the scenario that the amount of the baryons and the gravitino dark matter is naturally explained by the decay of the Q balls in the gauge-mediated SUSY breaking. We refine the decay rates into baryons, NLSPs, and gravitinos, and estimate their branching ratios based on the consideration of Pauli blocking. We obtain a smaller branching into gravitinos than the previous estimate, and the NLSPs are more produced by the Q-ball decay. However, the efficient annihilations of NLSPs occur afterward so that their abundance does not spoil the successful BBN and they only produce negligible amount of the gravitinos to the dark matter density by their decay. In this way, we find that the scenario with the direct production of the gravitino dark matter from the Q-ball decay works naturally.

The Tool Life of Ball Nose end Mill Depending on the Different Types of Ramping

Science.gov (United States)

Vopát, Tomáš; Peterka, Jozef; Kováč, Martin

2014-12-01

The article deals with the cutting tool wear measurement process and tool life of ball nose end mill depending on upward ramping and downward ramping. The aim was to determine and compare the wear (tool life) of ball nose end mill for different types of copy milling operations, as well as to specify particular steps of the measurement process. In addition, we examined and observed cutter contact areas of ball nose end mill with machined material. For tool life test, DMG DMU 85 monoBLOCK 5-axis CNC milling machine was used. In the experiment, cutting speed, feed rate, axial depth of cut and radial depth of cut were not changed. The cutting tool wear was measured on Zoller Genius 3s universal measuring machine. The results show different tool life of ball nose end mills depending on the copy milling strategy.

Determination of area reduction rate by continuous ball indentation test

International Nuclear Information System (INIS)

Zou, Bin; Guan, Kai Shu; Wu, Sheng Bao

2016-01-01

Rate of area reduction is an important mechanical property to appraise the plasticity of metals, which is always obtained from the uniaxial tensile test. A methodology is proposed to determine the area reduction rate by continuous ball indentation test technique. The continuum damage accumulation theory has been adopted in this work to identify the failure point in the indentation. The corresponding indentation depth of this point can be obtained and used to estimate the area reduction rate. The local strain limit criterion proposed in the ASME VIII-2 2007 alternative rules is also adopted in this research to convert the multiaxial strain of indentation test to uniaxial strain of tensile test. The pile-up and sink-in phenomenon which can affect the result significantly is also discussed in this paper. This method can be useful in engineering practice to evaluate the material degradation under severe working condition due to the non-destructive nature of ball indentation test. In order to validate the method, continuous ball indentation test is performed on ferritic steel 16MnR and ASTM (A193B16), then the results are compared with that got from the traditional uniaxial tensile test.

Nano-oxide nucleation in a 14Cr-ODS steel elaborated by reactive-inspired ball-milling: Multiscale characterizations