Development of a Charged-Particle Accumulator Using an RF Confinement Method VI

DTIC Science & Technology

2010-08-10

PROJECT NUMBER 5e. TASK NUMBER 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) University of Tokyo,7-3-1 Hongo , Bunkyo-ku...Department of Physics 7-3-1 Hongo , Bunkyo-ku, Tokyo 113-0033 - Phone : 03-5841-4235 - Fax : 03-4496-4043 Period of Performance: 2/9/2009 – 3/8/2010

An Aerosol Physical Chemistry Model for the Upper Troposphere

NASA Technical Reports Server (NTRS)

Lin, Jin-Sheng

2001-01-01

This report is the final report for the Cooperative Agreement NCC2-1000. The tasks outlined in the various proposals are listed with a brief comment as to the research performed. The publications titles are: The effects of particle size and nitric acid uptake on the homogenous freezing of sulfate aerosols; Parameterization of an aerosol physical chemistry model (APCM) for the NH3/H2SO4/HNO3/H2O system at cold temperatures; and The onset, extent and duration of dehydration in the Southern Hemisphere polar vortex.

A Model-Based Prognostics Approach Applied to Pneumatic Valves

NASA Technical Reports Server (NTRS)

Daigle, Matthew J.; Goebel, Kai

2011-01-01

Within the area of systems health management, the task of prognostics centers on predicting when components will fail. Model-based prognostics exploits domain knowledge of the system, its components, and how they fail by casting the underlying physical phenomena in a physics-based model that is derived from first principles. Uncertainty cannot be avoided in prediction, therefore, algorithms are employed that help in managing these uncertainties. The particle filtering algorithm has become a popular choice for model-based prognostics due to its wide applicability, ease of implementation, and support for uncertainty management. We develop a general model-based prognostics methodology within a robust probabilistic framework using particle filters. As a case study, we consider a pneumatic valve from the Space Shuttle cryogenic refueling system. We develop a detailed physics-based model of the pneumatic valve, and perform comprehensive simulation experiments to illustrate our prognostics approach and evaluate its effectiveness and robustness. The approach is demonstrated using historical pneumatic valve data from the refueling system.

DISPATCH: a numerical simulation framework for the exa-scale era - I. Fundamentals

NASA Astrophysics Data System (ADS)

Nordlund, Åke; Ramsey, Jon P.; Popovas, Andrius; Küffmeier, Michael

2018-06-01

We introduce a high-performance simulation framework that permits the semi-independent, task-based solution of sets of partial differential equations, typically manifesting as updates to a collection of `patches' in space-time. A hybrid MPI/OpenMP execution model is adopted, where work tasks are controlled by a rank-local `dispatcher' which selects, from a set of tasks generally much larger than the number of physical cores (or hardware threads), tasks that are ready for updating. The definition of a task can vary, for example, with some solving the equations of ideal magnetohydrodynamics (MHD), others non-ideal MHD, radiative transfer, or particle motion, and yet others applying particle-in-cell (PIC) methods. Tasks do not have to be grid based, while tasks that are, may use either Cartesian or orthogonal curvilinear meshes. Patches may be stationary or moving. Mesh refinement can be static or dynamic. A feature of decisive importance for the overall performance of the framework is that time-steps are determined and applied locally; this allows potentially large reductions in the total number of updates required in cases when the signal speed varies greatly across the computational domain, and therefore a corresponding reduction in computing time. Another feature is a load balancing algorithm that operates `locally' and aims to simultaneously minimize load and communication imbalance. The framework generally relies on already existing solvers, whose performance is augmented when run under the framework, due to more efficient cache usage, vectorization, local time-stepping, plus near-linear and, in principle, unlimited OpenMP and MPI scaling.

Report of the Dark Energy Task Force

DOE R&D Accomplishments Database

Albrecht, Andreas; Bernstein, Gary; Cahn, Robert; Freedman, Wendy L.; Hewitt, Jacqueline; Hu, Wayne; Huth, John; Kamionkowski, Marc; Kolb, Edward W.; Knox, Lloyd; Mather, John C.

2006-01-01

Dark energy appears to be the dominant component of the physical Universe, yet there is no persuasive theoretical explanation for its existence or magnitude. The acceleration of the Universe is, along with dark matter, the observed phenomenon that most directly demonstrates that our theories of fundamental particles and gravity are either incorrect or incomplete. Most experts believe that nothing short of a revolution in our understanding of fundamental physics will be required to achieve a full understanding of the cosmic acceleration. For these reasons, the nature of dark energy ranks among the very most compelling of all outstanding problems in physical science. These circumstances demand an ambitious observational program to determine the dark energy properties as well as possible.

DIRAC in Large Particle Physics Experiments

NASA Astrophysics Data System (ADS)

Stagni, F.; Tsaregorodtsev, A.; Arrabito, L.; Sailer, A.; Hara, T.; Zhang, X.; Consortium, DIRAC

2017-10-01

The DIRAC project is developing interware to build and operate distributed computing systems. It provides a development framework and a rich set of services for both Workload and Data Management tasks of large scientific communities. A number of High Energy Physics and Astrophysics collaborations have adopted DIRAC as the base for their computing models. DIRAC was initially developed for the LHCb experiment at LHC, CERN. Later, the Belle II, BES III and CTA experiments as well as the linear collider detector collaborations started using DIRAC for their computing systems. Some of the experiments built their DIRAC-based systems from scratch, others migrated from previous solutions, ad-hoc or based on different middlewares. Adaptation of DIRAC for a particular experiment was enabled through the creation of extensions to meet their specific requirements. Each experiment has a heterogeneous set of computing and storage resources at their disposal that were aggregated through DIRAC into a coherent pool. Users from different experiments can interact with the system in different ways depending on their specific tasks, expertise level and previous experience using command line tools, python APIs or Web Portals. In this contribution we will summarize the experience of using DIRAC in particle physics collaborations. The problems of migration to DIRAC from previous systems and their solutions will be presented. An overview of specific DIRAC extensions will be given. We hope that this review will be useful for experiments considering an update, or for those designing their computing models.

Correlation Characterization of Particles in Volume Based on Peak-to-Basement Ratio

PubMed Central

Vovk, Tatiana A.; Petrov, Nikolay V.

2017-01-01

We propose a new express method of the correlation characterization of the particles suspended in the volume of optically transparent medium. It utilizes inline digital holography technique for obtaining two images of the adjacent layers from the investigated volume with subsequent matching of the cross-correlation function peak-to-basement ratio calculated for these images. After preliminary calibration via numerical simulation, the proposed method allows one to quickly distinguish parameters of the particle distribution and evaluate their concentration. The experimental verification was carried out for the two types of physical suspensions. Our method can be applied in environmental and biological research, which includes analyzing tools in flow cytometry devices, express characterization of particles and biological cells in air and water media, and various technical tasks, e.g. the study of scattering objects or rapid determination of cutting tool conditions in mechanisms. PMID:28252020

The status of varying constants: a review of the physics, searches and implications.

PubMed

Martins, C J A P

2017-12-01

The observational evidence for the recent acceleration of the universe demonstrates that canonical theories of cosmology and particle physics are incomplete-if not incorrect-and that new physics is out there, waiting to be discovered. A key task for the next generation of laboratory and astrophysical facilities is to search for, identify and ultimately characterize this new physics. Here we highlight recent developments in tests of the stability of nature's fundamental couplings, which provide a direct handle on new physics: a detection of variations will be revolutionary, but even improved null results provide competitive constraints on a range of cosmological and particle physics paradigms. A joint analysis of all currently available data shows a preference for variations of α and μ at about the two-sigma level, but inconsistencies between different sub-sets (likely due to hidden systematics) suggest that these statistical preferences need to be taken with caution. On the other hand, these measurements strongly constrain Weak Equivalence Principle violations. Plans and forecasts for forthcoming studies with facilities such as ALMA, ESPRESSO and the ELT, which should clarify these issues, are also discussed, and synergies with other probes are briefly highlighted. The goal is to show how a new generation of precision consistency tests of the standard paradigm will soon become possible.

The status of varying constants: a review of the physics, searches and implications

NASA Astrophysics Data System (ADS)

Martins, C. J. A. P.

2017-12-01

The observational evidence for the recent acceleration of the universe demonstrates that canonical theories of cosmology and particle physics are incomplete—if not incorrect—and that new physics is out there, waiting to be discovered. A key task for the next generation of laboratory and astrophysical facilities is to search for, identify and ultimately characterize this new physics. Here we highlight recent developments in tests of the stability of nature’s fundamental couplings, which provide a direct handle on new physics: a detection of variations will be revolutionary, but even improved null results provide competitive constraints on a range of cosmological and particle physics paradigms. A joint analysis of all currently available data shows a preference for variations of α and μ at about the two-sigma level, but inconsistencies between different sub-sets (likely due to hidden systematics) suggest that these statistical preferences need to be taken with caution. On the other hand, these measurements strongly constrain Weak Equivalence Principle violations. Plans and forecasts for forthcoming studies with facilities such as ALMA, ESPRESSO and the ELT, which should clarify these issues, are also discussed, and synergies with other probes are briefly highlighted. The goal is to show how a new generation of precision consistency tests of the standard paradigm will soon become possible.

Particle sedimentation in a sheared viscoelastic fluid

NASA Astrophysics Data System (ADS)

Murch, William L.; Krishnan, Sreenath; Shaqfeh, Eric S. G.; Iaccarino, Gianluca

2017-11-01

Particle suspensions are ubiquitous in engineered processes, biological systems, and natural settings. For an engineering application - whether the intent is to suspend and transport particles (e.g., in hydraulic fracturing fluids) or allow particles to sediment (e.g., in industrial separations processes) - understanding and prediction of the particle mobility is critical. This task is often made challenging by the complex nature of the fluid phase, for example, due to fluid viscoelasticity. In this talk, we focus on a fully 3D flow problem in a viscoelastic fluid: a settling particle with a shear flow applied in the plane perpendicular to gravity (referred to as orthogonal shear). Previously, it has been shown that an orthogonal shear flow can reduce the settling rate of particles in viscoelastic fluids. Using experiments and numerical simulations across a wide range of sedimentation and shear Weissenberg number, this talk will address the underlying physical mechanism responsible for the additional drag experienced by a rigid sphere settling in a confined viscoelastic fluid with orthogonal shear. We will then explore multiple particle effects, and discuss the implications and extensions of this work for particle suspensions. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE-114747 (WLM).

Range Verification Methods in Particle Therapy: Underlying Physics and Monte Carlo Modeling

PubMed Central

Kraan, Aafke Christine

2015-01-01

Hadron therapy allows for highly conformal dose distributions and better sparing of organs-at-risk, thanks to the characteristic dose deposition as function of depth. However, the quality of hadron therapy treatments is closely connected with the ability to predict and achieve a given beam range in the patient. Currently, uncertainties in particle range lead to the employment of safety margins, at the expense of treatment quality. Much research in particle therapy is therefore aimed at developing methods to verify the particle range in patients. Non-invasive in vivo monitoring of the particle range can be performed by detecting secondary radiation, emitted from the patient as a result of nuclear interactions of charged hadrons with tissue, including β+ emitters, prompt photons, and charged fragments. The correctness of the dose delivery can be verified by comparing measured and pre-calculated distributions of the secondary particles. The reliability of Monte Carlo (MC) predictions is a key issue. Correctly modeling the production of secondaries is a non-trivial task, because it involves nuclear physics interactions at energies, where no rigorous theories exist to describe them. The goal of this review is to provide a comprehensive overview of various aspects in modeling the physics processes for range verification with secondary particles produced in proton, carbon, and heavier ion irradiation. We discuss electromagnetic and nuclear interactions of charged hadrons in matter, which is followed by a summary of some widely used MC codes in hadron therapy. Then, we describe selected examples of how these codes have been validated and used in three range verification techniques: PET, prompt gamma, and charged particle detection. We include research studies and clinically applied methods. For each of the techniques, we point out advantages and disadvantages, as well as clinical challenges still to be addressed, focusing on MC simulation aspects. PMID:26217586

Nature's Greatest Puzzles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quigg, Chris; /Fermilab

2005-02-01

It is a pleasure to be part of the SLAC Summer Institute again, not simply because it is one of the great traditions in our field, but because this is a moment of great promise for particle physics. I look forward to exploring many opportunities with you over the course of our two weeks together. My first task in talking about Nature's Greatest Puzzles, the title of this year's Summer Institute, is to deconstruct the premise a little bit.

ZENO: N-body and SPH Simulation Codes

NASA Astrophysics Data System (ADS)

Barnes, Joshua E.

2011-02-01

The ZENO software package integrates N-body and SPH simulation codes with a large array of programs to generate initial conditions and analyze numerical simulations. Written in C, the ZENO system is portable between Mac, Linux, and Unix platforms. It is in active use at the Institute for Astronomy (IfA), at NRAO, and possibly elsewhere. Zeno programs can perform a wide range of simulation and analysis tasks. While many of these programs were first created for specific projects, they embody algorithms of general applicability and embrace a modular design strategy, so existing code is easily applied to new tasks. Major elements of the system include: Structured data file utilities facilitate basic operations on binary data, including import/export of ZENO data to other systems.Snapshot generation routines create particle distributions with various properties. Systems with user-specified density profiles can be realized in collisionless or gaseous form; multiple spherical and disk components may be set up in mutual equilibrium.Snapshot manipulation routines permit the user to sift, sort, and combine particle arrays, translate and rotate particle configurations, and assign new values to data fields associated with each particle.Simulation codes include both pure N-body and combined N-body/SPH programs: Pure N-body codes are available in both uniprocessor and parallel versions.SPH codes offer a wide range of options for gas physics, including isothermal, adiabatic, and radiating models. Snapshot analysis programs calculate temporal averages, evaluate particle statistics, measure shapes and density profiles, compute kinematic properties, and identify and track objects in particle distributions.Visualization programs generate interactive displays and produce still images and videos of particle distributions; the user may specify arbitrary color schemes and viewing transformations.

Inhaled particle deposition in unsteady-state respiratory flow at a numerically constructed model of the human larynx.

PubMed

Takano, Hiroshi; Nishida, Naohiro; Itoh, Masayuki; Hyo, Noboru; Majima, Yuichi

2006-01-01

To evaluate the clinical effectiveness of aerosol therapy for the lower and upper respiratory airways, particle deposition at the human laryngeal region has been analyzed with various unsteady-state respiratory flow-patterns. The flow profiles and trajectory of aerosol particles were calculated by 3-D thermo-fluid analysis of a finite volume method (FVM) with 8-CPUs parallel computational system. A reconstructed physical model of the real laryngeal airways was modified from 3-D CAM modeling function of Rhinoceros based on the images of Magnetic Resonance Imaging (MRI). By using 104 MRI images taken vertically and horizontally at intervals of 2 mm on the oral cavity and the pharynx-larynx respectively, 3-D physical model of the laryngeal airways was obtained. The numerical results of flow profile analyzed by the unsteady-state respiration model showed that vortex flow was occurred with time at near larynx, showing uniform flow profile in both the oral cavity and upper side of pharynx. The vortex was appeared at the anterior part of the epiglottis and downward of the vocal cord. However, it was confirmed that few particles deposit in the vocal cord. In these cases, the particle deposition was taken place mostly at the oral cavity and the oropharynx. On the other hand, the relationship between the particle deposition efficiency and the impaction in the laryngeal region was well agreement with the data sets of ICRP task group (1993) for the larynx deposition.

Detecting the Neutrino

NASA Astrophysics Data System (ADS)

Arns, Robert G.

In 1930 Wolfgang Pauli suggested that a new particle might be required to make sense of the radioactive-disintegration mode known as beta decay. This conjecture initially seemed impossible to verify since the new particle, which became known as the neutrino, was uncharged, had zero or small mass, and interacted only insignificantly with other matter. In 1951 Frederick Reines and Clyde L. Cowan, Jr., of the Los Alamos Scientific Laboratory undertook the difficult task of detecting the free neutrino by observing its inverse beta-decay interaction with matter. They succeeded in 1956. The neutrino was accepted rapidly as a fundamental particle despite discrepancies in reported details of the experiments and despite the absence of independent verification of the result. This paper describes the experiments, examines the nature of the discrepancies, and discusses the circumstances of the acceptance of the neutrino's detection by the physics community.

CMS Physics Technical Design Report, Volume II: Physics Performance

NASA Astrophysics Data System (ADS)

CMS Collaboration

2007-06-01

CMS is a general purpose experiment, designed to study the physics of pp collisions at 14 TeV at the Large Hadron Collider (LHC). It currently involves more than 2000 physicists from more than 150 institutes and 37 countries. The LHC will provide extraordinary opportunities for particle physics based on its unprecedented collision energy and luminosity when it begins operation in 2007. The principal aim of this report is to present the strategy of CMS to explore the rich physics programme offered by the LHC. This volume demonstrates the physics capability of the CMS experiment. The prime goals of CMS are to explore physics at the TeV scale and to study the mechanism of electroweak symmetry breaking—through the discovery of the Higgs particle or otherwise. To carry out this task, CMS must be prepared to search for new particles, such as the Higgs boson or supersymmetric partners of the Standard Model particles, from the start-up of the LHC since new physics at the TeV scale may manifest itself with modest data samples of the order of a few fb -1 or less. The analysis tools that have been developed are applied to study in great detail and with all the methodology of performing an analysis on CMS data specific benchmark processes upon which to gauge the performance of CMS. These processes cover several Higgs boson decay channels, the production and decay of new particles such as Z' and supersymmetric particles, B s production and processes in heavy ion collisions. The simulation of these benchmark processes includes subtle effects such as possible detector miscalibration and misalignment. Besides these benchmark processes, the physics reach of CMS is studied for a large number of signatures arising in the Standard Model and also in theories beyond the Standard Model for integrated luminosities ranging from 1 fb -1 to 30 fb -1 . The Standard Model processes include QCD, B -physics, diffraction, detailed studies of the top quark properties, and electroweak physics topics such as the W and Z 0 boson properties. The production and decay of the Higgs particle is studied for many observable decays, and the precision with which the Higgs boson properties can be derived is determined. About ten different supersymmetry benchmark points are analysed using full simulation. The CMS discovery reach is evaluated in the SUSY parameter space covering a large variety of decay signatures. Furthermore, the discovery reach for a plethora of alternative models for new physics is explored, notably extra dimensions, new vector boson high mass states, little Higgs models, technicolour and others. Methods to discriminate between models have been investigated. This report is organized as follows. Chapter 1, the Introduction, describes the context of this document. Chapters 2 6 describe examples of full analyses, with photons, electrons, muons, jets, missing E T , B-mesons and τ's, and for quarkonia in heavy ion collisions. Chapters 7 15 describe the physics reach for Standard Model processes, Higgs discovery and searches for new physics beyond the Standard Model.

Methods for the physical characterization and quantification of extracellular vesicles in biological samples.

PubMed

Rupert, Déborah L M; Claudio, Virginia; Lässer, Cecilia; Bally, Marta

2017-01-01

Our body fluids contain a multitude of cell-derived vesicles, secreted by most cell types, commonly referred to as extracellular vesicles. They have attracted considerable attention for their function as intercellular communication vehicles in a broad range of physiological processes and pathological conditions. Extracellular vesicles and especially the smallest type, exosomes, have also generated a lot of excitement in view of their potential as disease biomarkers or as carriers for drug delivery. In this context, state-of-the-art techniques capable of comprehensively characterizing vesicles in biological fluids are urgently needed. This review presents the arsenal of techniques available for quantification and characterization of physical properties of extracellular vesicles, summarizes their working principles, discusses their advantages and limitations and further illustrates their implementation in extracellular vesicle research. The small size and physicochemical heterogeneity of extracellular vesicles make their physical characterization and quantification an extremely challenging task. Currently, structure, size, buoyant density, optical properties and zeta potential have most commonly been studied. The concentration of vesicles in suspension can be expressed in terms of biomolecular or particle content depending on the method at hand. In addition, common quantification methods may either provide a direct quantitative measurement of vesicle concentration or solely allow for relative comparison between samples. The combination of complementary methods capable of detecting, characterizing and quantifying extracellular vesicles at a single particle level promises to provide new exciting insights into their modes of action and to reveal the existence of vesicle subpopulations fulfilling key biological tasks. Copyright © 2016 Elsevier B.V. All rights reserved.

Coal Combustion Science quarterly progress report, April--June 1992. Task 1, Coal devolatilization: Task 2, Coal char combustion; Task 3, Fate of mineral matter

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardesty, D.R.; Hurt, R.H.; Baxter, L.L.

1992-09-01

The objective of this work is to support the Office of Fossil Energy in executing research on coal combustion science. This project consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: The characterization of the physical and chemical processes that constitute the early devolatilization phase of coal combustion: Characterization of the combustion behavior of selected coals under conditions relevant to industria pulverized coal-fired furnaces; and to establish a quantitative understanding of themore » mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distributions of mineral species in the unreacted coal, and the local gas temperature and composition.« less

Versatile microrobotics using simple modular subunits

NASA Astrophysics Data System (ADS)

Cheang, U. Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

2016-07-01

The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size.

Versatile microrobotics using simple modular subunits

PubMed Central

Cheang, U Kei; Meshkati, Farshad; Kim, Hoyeon; Lee, Kyoungwoo; Fu, Henry Chien; Kim, Min Jun

2016-01-01

The realization of reconfigurable modular microrobots could aid drug delivery and microsurgery by allowing a single system to navigate diverse environments and perform multiple tasks. So far, microrobotic systems are limited by insufficient versatility; for instance, helical shapes commonly used for magnetic swimmers cannot effectively assemble and disassemble into different size and shapes. Here by using microswimmers with simple geometries constructed of spherical particles, we show how magnetohydrodynamics can be used to assemble and disassemble modular microrobots with different physical characteristics. We develop a mechanistic physical model that we use to improve assembly strategies. Furthermore, we experimentally demonstrate the feasibility of dynamically changing the physical properties of microswimmers through assembly and disassembly in a controlled fluidic environment. Finally, we show that different configurations have different swimming properties by examining swimming speed dependence on configuration size. PMID:27464852

An Active Approach to Colloidal Self-Assembly

NASA Astrophysics Data System (ADS)

Mallory, Stewart A.; Valeriani, Chantal; Cacciuto, Angelo

2018-04-01

In this review, we discuss recent advances in the self-assembly of self-propelled colloidal particles and highlight some of the most exciting results in this field, with a specific focus on dry active matter. We explore this phenomenology through the lens of the complexity of the colloidal building blocks. We begin by considering the behavior of isotropic spherical particles. We then discuss the case of amphiphilic and dipolar Janus particles. Finally, we show how the geometry of the colloids and/or the directionality of their interactions can be used to control the physical properties of the assembled active aggregates, and we suggest possible strategies for how to exploit activity as a tunable driving force for self-assembly. The unique properties of active colloids lend promise to the design of the next generation of functional, environment-sensing microstructures able to perform specific tasks in an autonomous and targeted manner.

Deposition kinetics of colloidal particles at high ionic strengths

NASA Astrophysics Data System (ADS)

Cejas, Cesare; Monti, Fabrice; Truchet, Marine; Burnouf, Jean-Pierre; Tabeling, Patrick

Using microfluidic experiments, we describe the deposition of a fluid suspension of weakly brownian particles transported in a straight channel at small Reynolds numbers under conditions of high ionic strengths. Our studies fall in a regime where electrostatic interactions are neglected and particle-wall van der Waals interactions govern the deposition mechanism on channel walls. We calculate the deposition kinetics analytically for a wide range of physical parameters. We find that the theory agrees with numerical Langevin simulations, which both confirm the experimental results. From this analysis, we demonstrate a universal dimensionless deposition function described by contributions from advection-diffusion transport and adhesion interactions (Hamaker constant). Results show that we accurately confirm the theoretical expression for the deposition kinetics. From a surface science perspective, working in the van der Waals regime enables to measure the Hamaker constant, a task that would take much longer to perform with the standard AFM. Funding from Sanofi Recherche and ESPCI.

Studies of HZE particle interactions and transport for space radiation protection purposes

NASA Technical Reports Server (NTRS)

Townsend, Lawrence W.; Wilson, John W.; Schimmerling, Walter; Wong, Mervyn

1987-01-01

The main emphasis is on developing general methods for accurately predicting high-energy heavy ion (HZE) particle interactions and transport for use by researchers in mission planning studies, in evaluating astronaut self-shielding factors, and in spacecraft shield design and optimization studies. The two research tasks are: (1) to develop computationally fast and accurate solutions to the Boltzmann (transport) equation; and (2) to develop accurate HZE interaction models, from fundamental physical considerations, for use as inputs into these transport codes. Accurate solutions to the HZE transport problem have been formulated through a combination of analytical and numerical techniques. In addition, theoretical models for the input interaction parameters are under development: stopping powers, nuclear absorption cross sections, and fragmentation parameters.

Proceedings of the Quantum Computation for Physical Modeling Workshop Held in North Falmouth, Massachusetts on October 18-19, 2000

DTIC Science & Technology

2002-01-01

1-3], a task that is exponen- algorithms to model quantum mechanical systems. tially complex in the number of particles treated and A starting point ...cell size approaches zero). There- tion were presented by Succi and Benzi [10,11] and fore, from the point -of-view of the modeler, there ex- by... point regarding this particular In both cases, the model behaves as expected. gate is that when measurements are periodically made Third, in Section 4

Cognitive and Physical Fatigue Tasks Enhance Pain, Cognitive Fatigue and Physical Fatigue in People with Fibromyalgia

PubMed Central

Dailey, Dana L; Keffala, Valerie J; Sluka, Kathleen A

2014-01-01

Objective Fibromyalgia is a condition characterized by chronic widespread muscle pain and fatigue. The primary objective of this study was to determine if pain, perceived cognitive fatigue, and perceived physical fatigue were enhanced in participants with fibromyalgia compared to healthy controls during a cognitive fatigue task, a physical fatigue task and a dual fatigue task. Methods Twenty four people with fibromyalgia and 33 healthy controls completed pain, fatigue and function measures. A cognitive fatigue task (Controlled Oral Word Association Test) and physical fatigue task (Valpar peg test) were done individually and combined for a dual fatigue task. Resting pain, perceived cognitive fatigue and perceived physical fatigue were assessed during each task using visual analogue scales. Function was assessed with shoulder range of motion and grip. Results People with fibromyalgia had significantly higher increases in pain, cognitive fatigue and physical fatigue when compared to healthy controls after completion of a cognitive fatigue task, a physical fatigue task, or a dual fatigue task (p<0.01). People with fibromyalgia performed equivalently on measures of physical performance and cognitive performance on the physical and cognitive fatigue tasks, respectively. Conclusions These data show that people with fibromyalgia show larger increases in pain, perceived cognitive fatigue and perceived physical fatigue to both cognitive and physical fatigue tasks compared to healthy controls. The increases in pain and fatigue during cognitive and physical fatigue tasks could influence subject participation in daily activities and rehabilitation. PMID:25074583

Data re-arranging techniques leading to proper variable selections in high energy physics

NASA Astrophysics Data System (ADS)

Kůs, Václav; Bouř, Petr

2017-12-01

We introduce a new data based approach to homogeneity testing and variable selection carried out in high energy physics experiments, where one of the basic tasks is to test the homogeneity of weighted samples, mainly the Monte Carlo simulations (weighted) and real data measurements (unweighted). This technique is called ’data re-arranging’ and it enables variable selection performed by means of the classical statistical homogeneity tests such as Kolmogorov-Smirnov, Anderson-Darling, or Pearson’s chi-square divergence test. P-values of our variants of homogeneity tests are investigated and the empirical verification through 46 dimensional high energy particle physics data sets is accomplished under newly proposed (equiprobable) quantile binning. Particularly, the procedure of homogeneity testing is applied to re-arranged Monte Carlo samples and real DATA sets measured at the particle accelerator Tevatron in Fermilab at DØ experiment originating from top-antitop quark pair production in two decay channels (electron, muon) with 2, 3, or 4+ jets detected. Finally, the variable selections in the electron and muon channels induced by the re-arranging procedure for homogeneity testing are provided for Tevatron top-antitop quark data sets.

Acute physical exercise affected processing efficiency in an auditory attention task more than processing effectiveness.

PubMed

Dutke, Stephan; Jaitner, Thomas; Berse, Timo; Barenberg, Jonathan

2014-02-01

Research on effects of acute physical exercise on performance in a concurrent cognitive task has generated equivocal evidence. Processing efficiency theory predicts that concurrent physical exercise can increase resource requirements for sustaining cognitive performance even when the level of performance is unaffected. This hypothesis was tested in a dual-task experiment. Sixty young adults worked on a primary auditory attention task and a secondary interval production task while cycling on a bicycle ergometer. Physical load (cycling) and cognitive load of the primary task were manipulated. Neither physical nor cognitive load affected primary task performance, but both factors interacted on secondary task performance. Sustaining primary task performance under increased physical and/or cognitive load increased resource consumption as indicated by decreased secondary task performance. Results demonstrated that physical exercise effects on cognition might be underestimated when only single task performance is the focus.

Job task characteristics of Australian emergency services volunteers during search and rescue operations.

PubMed

Silk, Aaron; Lenton, Gavin; Savage, Robbie; Aisbett, Brad

2018-02-01

Search and rescue operations are necessary in locating, assisting and recovering individuals lost or in distress. In Australia, land-based search and rescue roles require a range of physically demanding tasks undertaken in dynamic and challenging environments. The aim of the current research was to identify and characterise the physically demanding tasks inherent to search and rescue operation personnel within Australia. These aims were met through a subjective job task analysis approach. In total, 11 criterion tasks were identified by personnel. These tasks were the most physically demanding, frequently occurring and operationally important tasks to these specialist roles. Muscular strength was the dominant fitness component for 7 of the 11 tasks. In addition to the discrete criterion tasks, an operational scenario was established. With the tasks and operational scenario identified, objective task analysis procedures can be undertaken so that practitioners can implement evidence-based strategies, such as physical selection procedures and task-based physical training programs, commensurate with the physical demands of search and rescue job roles. Practitioner Summary: The identification of physically demanding tasks amongst specialist emergency service roles predicates health and safety strategies which can be incorporated into organisations. Knowledge of physical task parameters allows employers to mitigate injury risk through the implementation of strategies modelled on the precise physical demands of the role.

Tests and prospects of new physics at very high energy. Beyond the standard basic principles, and beyond conventional matter and space-time. On the possible origin of Quantum Mechanics.

NASA Astrophysics Data System (ADS)

Gonzalez-Mestres, Luis

2015-05-01

Recent results and announcements by Planck and BICEP2 have led to important controversies in the fields of Cosmology and Particle Physics. As new ideas and alternative approaches can since then more easily emerge, the link between the Mathematical Physics aspects of theories and the interpretation of experimental results becomes more direct. This evolution is also relevant for Particle Physics experiments at very high energy, where the interpretation of data on the highest-energy cosmic rays remains a major theoretical and phenomenological challenge. Alternative particle physics and cosmology can raise fundamental questions such as that of the structure of vacuum and space-time. In particular, the simplified description of the physical vacuum contained in standard quantum field theory does not necessarily correspond to reality at a deeper level, and similarly for the relativistic space-time based on four real variables. In a more general approach, the definition itself of vacuum can be a difficult task. The spinorial space-time (SST) we suggested in 1996-97 automatically incorporates a local privileged space direction (PSD) for each comoving observer, possibly leading to a locally anisotropic vacuum structure. As the existence of the PSD may have been confirmed by Planck, and a possible discovery of primordial B-modes in the polarization of the cosmic microwave background radiation (CMB) may turn out to contain new evidence for the SST, we explore other possible implications of this approach to space-time. The SST structure can naturally be at the origin of Quantum Mechanics at distance scales larger than the fundamental one if standard particles are dealt with as vacuum excitations. We also discuss possible implications of our lack of knowledge of the structure of vacuum, as well as related theoretical, phenomenological and cosmological uncertainties. Pre-Big Bang scenarios and new ultimate constituents of matter (including superbradyons) are crucial open subjects, together with vacuum structure and the interaction between vacuum and standard matter.

Physical similarity or numerical representation counts in same-different, numerical comparison, physical comparison, and priming tasks?

PubMed

Zhang, Li; Xin, Ziqiang; Feng, Tingyong; Chen, Yinghe; Szűcs, Denes

2018-03-01

Recent studies have highlighted the fact that some tasks used to study symbolic number representations are confounded by judgments about physical similarity. Here, we investigated whether the contribution of physical similarity and numerical representation differed in the often-used symbolic same-different, numerical comparison, physical comparison, and priming tasks. Experiment 1 showed that subjective physical similarity was the best predictor of participants' performance in the same-different task, regardless of simultaneous or sequential presentation. Furthermore, the contribution of subjective physical similarity was larger in a simultaneous presentation than in a sequential presentation. Experiment 2 showed that only numerical representation was involved in numerical comparison. Experiment 3 showed that both subjective physical similarity and numerical representation contributed to participants' physical comparison performance. Finally, only numerical representation contributed to participants' performance in a priming task as revealed by Experiment 4. Taken together, the contribution of physical similarity and numerical representation depends on task demands. Performance primarily seems to rely on numerical properties in tasks that require explicit quantitative comparison judgments (physical or numerical), while physical stimulus properties exert an effect in the same-different task.

Perspectives in quantum physics: Epistemological, ontological and pedagogical An investigation into student and expert perspectives on the physical interpretation of quantum mechanics, with implications for modern physics instruction

NASA Astrophysics Data System (ADS)

Baily, Charles Raymond

A common learning goal for modern physics instructors is for students to recognize a difference between the experimental uncertainty of classical physics and the fundamental uncertainty of quantum mechanics. Our studies suggest this notoriously difficult task may be frustrated by the intuitively realist perspectives of introductory students, and a lack of ontological flexibility in their conceptions of light and matter. We have developed a framework for understanding and characterizing student perspectives on the physical interpretation of quantum mechanics, and demonstrate the differential impact on student thinking of the myriad ways instructors approach interpretive themes in their introductory courses. Like expert physicists, students interpret quantum phenomena differently, and these interpretations are significantly influenced by their overall stances on questions central to the so-called measurement problem: Is the wave function physically real, or simply a mathematical tool? Is the collapse of the wave function an ad hoc rule, or a physical transition not described by any equation? Does an electron, being a form of matter, exist as a localized particle at all times? These questions, which are of personal and academic interest to our students, are largely only superficially addressed in our introductory courses, often for fear of opening a Pandora's Box of student questions, none of which have easy answers. We show how a transformed modern physics curriculum (recently implemented at the University of Colorado) may positively impact student perspectives on indeterminacy and wave-particle duality, by making questions of classical and quantum reality a central theme of our course, but also by making the beliefs of our students, and not just those of scientists, an explicit topic of discussion.

U.S. Army physical demands study: Prevalence and frequency of performing physically demanding tasks in deployed and non-deployed settings.

PubMed

Boye, Michael W; Cohen, Bruce S; Sharp, Marilyn A; Canino, Maria C; Foulis, Stephen A; Larcom, Kathleen; Smith, Laurel

2017-11-01

To compare percentages of on-duty time spent performing physically demanding soldier tasks in non-deployed and deployed settings, and secondarily examine the number of physically demanding tasks performed among five Army combat arms occupational specialties. Job task analysis. Soldiers (n=1295; over 99% serving on active duty) across five Army jobs completed one of three questionnaires developed using reviews of job and task related documents, input from subject matter experts, observation of task performance, and conduct of focus groups. Soldiers reported estimates of the total on-duty time spent performing physically demanding tasks in both deployed and non-deployed settings. One-way analyses of variance and Duncan post-hoc tests were used to compare percentage time differences by job. Two-tailed t-tests were used to evaluate differences by setting. Frequency analyses were used to present supplementary findings. Soldiers reported performing physically demanding job-specific tasks 17.7% of the time while non-deployed and 19.6% of the time while deployed. There were significant differences in time spent on job-specific tasks across settings (p<0.05) for three of five occupational specialties. When categories of physically demanding tasks were grouped, all soldiers reported spending more time on physically demanding tasks when deployed (p<0.001). Twenty-five percent reported performing less than half the physically demanding tasks represented on the questionnaire in the last two years. Soldiers spent more time performing physically demanding tasks while deployed compared to non-deployed but spent similar amounts of time performing job-specific tasks. Published by Elsevier Ltd.

Application of State Quantization-Based Methods in HEP Particle Transport Simulation

NASA Astrophysics Data System (ADS)

Santi, Lucio; Ponieman, Nicolás; Jun, Soon Yung; Genser, Krzysztof; Elvira, Daniel; Castro, Rodrigo

2017-10-01

Simulation of particle-matter interactions in complex geometries is one of the main tasks in high energy physics (HEP) research. An essential aspect of it is an accurate and efficient particle transportation in a non-uniform magnetic field, which includes the handling of volume crossings within a predefined 3D geometry. Quantized State Systems (QSS) is a family of numerical methods that provides attractive features for particle transportation processes, such as dense output (sequences of polynomial segments changing only according to accuracy-driven discrete events) and lightweight detection and handling of volume crossings (based on simple root-finding of polynomial functions). In this work we present a proof-of-concept performance comparison between a QSS-based standalone numerical solver and an application based on the Geant4 simulation toolkit, with its default Runge-Kutta based adaptive step method. In a case study with a charged particle circulating in a vacuum (with interactions with matter turned off), in a uniform magnetic field, and crossing up to 200 volume boundaries twice per turn, simulation results showed speedups of up to 6 times in favor of QSS while it being 10 times slower in the case with zero volume boundaries.

MO-DE-BRA-01: Enhancing Radiation Physics Instruction Through Gamification and E-Learning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Driewer, J; Lei, Y; Morgan, B

Purpose: This project sought to “gamify” the instruction of radiation interaction physics concepts for technology students. Gamification applies game mechanics and user interactions in active learning contexts. In one part of this project, a self-guided eModule was developed for conceptual radiation interaction instruction. In a second part, a web-based game, Particle Launch (http://particle-launcher.ist.unomaha.edu), was created to challenge students to quickly apply radiation interaction concepts in a way that is stimulating and motivating. Methods: The eModule, focused on conceptual interaction physics, was designed in Adobe Captivate and incorporates animation, web videos, and assessment questions in order to generate student interest. Navigatingmore » the whole module takes 40 minutes for beginners. Assessments after three main sections are comprised of 3–4 questions randomly selected from a question pool. In collaboration with the University of Nebraska at Omaha’s College of Information Science and Technology, the Particle Launch game was created with the Unity gaming engine and designed with a game-play look and feel. The object of the game is to utilize different particles, energies, and directions to destroy a target given a limited number of resources and time to complete the task. A rewards system encourages accurate shots. Results: The eModule part of the project encourages a flipped classroom model in which class time is devoted to application of concepts rather than information-based lectures. Currently, eModule assessments are not tracked but this feature could be incorporated to encourage participation. Furthermore, in a class of five technology students, the game was found to be fun and engaging and had the effect of reinforcing basic concepts from the eModule. Conclusion: Gamification has significant potential to alter medical physics instruction. Game-play feedback is an important part of the learning process. Students found Particle Launch inviting and challenging and further research could help game design. This project was generously supported by the Office of the Vice-Chancellor for Academic Affairs and the University of Nebraska Medical Center.« less

Variation at work: alternations between physically and mentally demanding tasks in blue-collar occupations.

PubMed

Jahncke, Helena; Hygge, Staffan; Mathiassen, Svend Erik; Hallman, David; Mixter, Susanna; Lyskov, Eugene

2017-09-01

The aims of this questionnaire study were to describe the occurrence and desired number of alternations between mental and physical tasks in industrial and non-industrial blue-collar work, and determine to which extent selected personal and occupational factors influence these conditions. On average, the 122 participating workers (55 females) reported to have close to four alternations per day between mental and physical tasks, and to desire more alternations than they actually had. They also expressed a general preference for performing a physical task after a mental task and vice versa. In univariate regression models, the desired change in task alternations was significantly associated with gender, age, occupation, years with current work tasks and perceived job control, while occupation was the only significant determinant in a multiple regression model including all factors. Our results suggest that alternations between productive physical and mental tasks could be a viable option in future job rotation. Practitioner Summary: We addressed attitudes among blue-collar workers to alternations between physically and mentally demanding tasks. More alternations were desired than those occurring in the job, and workers preferred performing a physical task after a mental and vice versa. Alternating physical and mental tasks could, thus, be a viable option in job rotation.

Inner space/outer space - The interface between cosmology and particle physics

NASA Astrophysics Data System (ADS)

Kolb, Edward W.; Turner, Michael S.; Lindley, David; Olive, Keith; Seckel, David

A collection of papers covering the synthesis between particle physics and cosmology is presented. The general topics addressed include: standard models of particle physics and cosmology; microwave background radiation; origin and evolution of large-scale structure; inflation; massive magnetic monopoles; supersymmetry, supergravity, and quantum gravity; cosmological constraints on particle physics; Kaluza-Klein cosmology; and future directions and connections in particle physics and cosmology.

Depositing nanoparticles on a silicon substrate using a freeze drying technique.

PubMed

Sigehuzi, Tomoo

2017-08-28

For the microscopic observation of nanoparticles, an adequate sample preparation is an essential part of this task. Much research has been performed for usable preparation methods that will yield aggregate-free samples. A freeze drying technique, which only requires a -80  ° C freezer and a freeze dryer, is shown to provide an on-substrate dispersion of mostly isolated nanoparticles. The particle density could be made sufficiently high for efficient observations using atomic force microscopy. Since this sandwich method is purely physical, it could be applied to deposit various nanoparticles independent of their surface chemical properties. Suspension film thickness, or the dimensionality of the suspension film, was shown to be crucial for the isolation of the particles. Silica nanoparticles were dispersed on a silicon substrate using this method and the sample properties were examined using atomic force microscopy.

The Pandora multi-algorithm approach to automated pattern recognition in LAr TPC detectors

NASA Astrophysics Data System (ADS)

Marshall, J. S.; Blake, A. S. T.; Thomson, M. A.; Escudero, L.; de Vries, J.; Weston, J.; MicroBooNE Collaboration

2017-09-01

The development and operation of Liquid Argon Time Projection Chambers (LAr TPCs) for neutrino physics has created a need for new approaches to pattern recognition, in order to fully exploit the superb imaging capabilities offered by this technology. The Pandora Software Development Kit provides functionality to aid the process of designing, implementing and running pattern recognition algorithms. It promotes the use of a multi-algorithm approach to pattern recognition: individual algorithms each address a specific task in a particular topology; a series of many tens of algorithms then carefully builds-up a picture of the event. The input to the Pandora pattern recognition is a list of 2D Hits. The output from the chain of over 70 algorithms is a hierarchy of reconstructed 3D Particles, each with an identified particle type, vertex and direction.

Single particle fluorescence: a simple experimental approach to evaluate coincidence effects.

PubMed

Wu, Xihong; Omenetto, Nicoló; Smith, Benjamin W; Winefordner, James D

2007-07-01

Real-time characterization of the chemical and physical properties of individual aerosol particles is an important issue in environmental studies. A well-established way of accomplishing this task relies on the use of laser-induced fluorescence or laser ionization mass spectrometry. We describe here a simple approach aimed at experimentally verifying that single particles are indeed addressed. The approach has been tested with a system consisting of a series of aerodynamic lenses to form a beam of dye-doped particles aerosolized from a solution of known concentration with a medical nebulizer. Two independent spectral detection channels simultaneously measure the fluorescence signals generated in two different spectral regions by the passage of a mixture of two dye-doped particles through a focused laser beam in a vacuum chamber. Coincidence effects, arising from the simultaneous observation of both fluorescence emissions, can then be directly observed. Both dual-color fluorescence and pulse height distribution have been analyzed. As expected, the probability of single- or multiple-particle interaction strongly depends on the particle flux in the chamber, which is related to the concentration of particles in the nebulized solution. In our case, to achieve a two-particle coincidence smaller than 10%, a particle concentration lower than 1.2x10(5) particles/mL is required. Moreover, it was found that the experimental observations are in agreement with a simple mathematical model based on Poisson statistics. Although the results obtained refer to particle concentrations in solution, our approach can equally be applicable to experiments involving direct air sampling, provided that the number density of particles in air can be measured a priori, e.g., with a particle counter.

Carbon Nanotube Emissions from Arc Discharge Production: Classification of Particle Types with Electron Microscopy and Comparison with Direct Reading Techniques.

PubMed

Ludvigsson, Linus; Isaxon, Christina; Nilsson, Patrik T; Tinnerberg, Hakan; Messing, Maria E; Rissler, Jenny; Skaug, Vidar; Gudmundsson, Anders; Bohgard, Mats; Hedmer, Maria; Pagels, Joakim

2016-05-01

An increased production and use of carbon nanotubes (CNTs) is occurring worldwide. In parallel, a growing concern is emerging on the adverse effects the unintentional inhalation of CNTs can have on humans. There is currently a debate regarding which exposure metrics and measurement strategies are the most relevant to investigate workplace exposures to CNTs. This study investigated workplace CNT emissions using a combination of time-integrated filter sampling for scanning electron microscopy (SEM) and direct reading aerosol instruments (DRIs). Field measurements were performed during small-scale manufacturing of multiwalled carbon nanotubes using the arc discharge technique. Measurements with highly time- and size-resolved DRI techniques were carried out both in the emission and background (far-field) zones. Novel classifications and counting criteria were set up for the SEM method. Three classes of CNT-containing particles were defined: type 1: particles with aspect ratio length:width >3:1 (fibrous particles); type 2: particles without fibre characteristics but with high CNT content; and type 3: particles with visible embedded CNTs. Offline sampling using SEM showed emissions of CNT-containing particles in 5 out of 11 work tasks. The particles were classified into the three classes, of which type 1, fibrous CNT particles contributed 37%. The concentration of all CNT-containing particles and the occurrence of the particle classes varied strongly between work tasks. Based on the emission measurements, it was assessed that more than 85% of the exposure originated from open handling of CNT powder during the Sieving, mechanical work-up, and packaging work task. The DRI measurements provided complementary information, which combined with SEM provided information on: (i) the background adjusted emission concentration from each work task in different particle size ranges, (ii) identification of the key procedures in each work task that lead to emission peaks, (iii) identification of emission events that affect the background, thereby leading to far-field exposure risks for workers other than the operator of the work task, and (iv) the fraction of particles emitted from each source that contains CNTs. There is an urgent need for a standardized/harmonized method for electron microscopy (EM) analysis of CNTs. The SEM method developed in this study can form the basis for such a harmonized protocol for the counting of CNTs. The size-resolved DRI techniques are commonly not specific enough to selective analysis of CNT-containing particles and thus cannot yet replace offline time-integrated filter sampling followed by SEM. A combination of EM and DRI techniques offers the most complete characterization of workplace emissions of CNTs today. © The Author 2016. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Stochastic optimization of GeantV code by use of genetic algorithms

DOE PAGES

Amadio, G.; Apostolakis, J.; Bandieramonte, M.; ...

2017-10-01

GeantV is a complex system based on the interaction of different modules needed for detector simulation, which include transport of particles in fields, physics models simulating their interactions with matter and a geometrical modeler library for describing the detector and locating the particles and computing the path length to the current volume boundary. The GeantV project is recasting the classical simulation approach to get maximum benefit from SIMD/MIMD computational architectures and highly massive parallel systems. This involves finding the appropriate balance between several aspects influencing computational performance (floating-point performance, usage of off-chip memory bandwidth, specification of cache hierarchy, etc.) andmore » handling a large number of program parameters that have to be optimized to achieve the best simulation throughput. This optimization task can be treated as a black-box optimization problem, which requires searching the optimum set of parameters using only point-wise function evaluations. Here, the goal of this study is to provide a mechanism for optimizing complex systems (high energy physics particle transport simulations) with the help of genetic algorithms and evolution strategies as tuning procedures for massive parallel simulations. One of the described approaches is based on introducing a specific multivariate analysis operator that could be used in case of resource expensive or time consuming evaluations of fitness functions, in order to speed-up the convergence of the black-box optimization problem.« less

Stochastic optimization of GeantV code by use of genetic algorithms

NASA Astrophysics Data System (ADS)

Amadio, G.; Apostolakis, J.; Bandieramonte, M.; Behera, S. P.; Brun, R.; Canal, P.; Carminati, F.; Cosmo, G.; Duhem, L.; Elvira, D.; Folger, G.; Gheata, A.; Gheata, M.; Goulas, I.; Hariri, F.; Jun, S. Y.; Konstantinov, D.; Kumawat, H.; Ivantchenko, V.; Lima, G.; Nikitina, T.; Novak, M.; Pokorski, W.; Ribon, A.; Seghal, R.; Shadura, O.; Vallecorsa, S.; Wenzel, S.

2017-10-01

GeantV is a complex system based on the interaction of different modules needed for detector simulation, which include transport of particles in fields, physics models simulating their interactions with matter and a geometrical modeler library for describing the detector and locating the particles and computing the path length to the current volume boundary. The GeantV project is recasting the classical simulation approach to get maximum benefit from SIMD/MIMD computational architectures and highly massive parallel systems. This involves finding the appropriate balance between several aspects influencing computational performance (floating-point performance, usage of off-chip memory bandwidth, specification of cache hierarchy, etc.) and handling a large number of program parameters that have to be optimized to achieve the best simulation throughput. This optimization task can be treated as a black-box optimization problem, which requires searching the optimum set of parameters using only point-wise function evaluations. The goal of this study is to provide a mechanism for optimizing complex systems (high energy physics particle transport simulations) with the help of genetic algorithms and evolution strategies as tuning procedures for massive parallel simulations. One of the described approaches is based on introducing a specific multivariate analysis operator that could be used in case of resource expensive or time consuming evaluations of fitness functions, in order to speed-up the convergence of the black-box optimization problem.

Stochastic optimization of GeantV code by use of genetic algorithms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Amadio, G.; Apostolakis, J.; Bandieramonte, M.

GeantV is a complex system based on the interaction of different modules needed for detector simulation, which include transport of particles in fields, physics models simulating their interactions with matter and a geometrical modeler library for describing the detector and locating the particles and computing the path length to the current volume boundary. The GeantV project is recasting the classical simulation approach to get maximum benefit from SIMD/MIMD computational architectures and highly massive parallel systems. This involves finding the appropriate balance between several aspects influencing computational performance (floating-point performance, usage of off-chip memory bandwidth, specification of cache hierarchy, etc.) andmore » handling a large number of program parameters that have to be optimized to achieve the best simulation throughput. This optimization task can be treated as a black-box optimization problem, which requires searching the optimum set of parameters using only point-wise function evaluations. Here, the goal of this study is to provide a mechanism for optimizing complex systems (high energy physics particle transport simulations) with the help of genetic algorithms and evolution strategies as tuning procedures for massive parallel simulations. One of the described approaches is based on introducing a specific multivariate analysis operator that could be used in case of resource expensive or time consuming evaluations of fitness functions, in order to speed-up the convergence of the black-box optimization problem.« less

Physical and chemical properties of ice residuals during the 2013 and 2014 CLACE campaigns

NASA Astrophysics Data System (ADS)

Kupiszewski, Piotr; Weingartner, Ernest; Vochezer, Paul; Hammer, Emanuel; Gysel, Martin; Färber, Raphael; Fuchs, Claudia; Schnaiter, Martin; Baltensperger, Urs; Schmidt, Susan; Schneider, Johannes; Bigi, Alessandro; Toprak, Emre; Linke, Claudia; Klimach, Thomas

2014-05-01

The shortcomings in our understanding and, thus, representation of aerosol-cloud interactions are one of the major sources of uncertainty in climate model projections. Among the poorly understood processes is mixed-phase cloud formation via heterogeneous nucleation, and the subsequent spatial and temporal evolution of such clouds. Cloud glaciation augments precipitation formation, resulting in decreased cloud cover and lifetime, and affects cloud radiative properties. Meanwhile, the physical and chemical properties of atmospherically relevant ice nuclei (IN), the sub-population of aerosol particles which enable heterogeneous nucleation, are not well known. Extraction of ice residuals (IR) in mixed-phase clouds is a difficult task, requiring separation of the few small, freshly formed ice crystals (the IR within such crystals can be deemed representative of the original IN) not only from interstitial particles, but also from the numerous supercooled droplets which have aerodynamic diameters similar to those of the ice crystals. In order to address the difficulties with ice crystal sampling and IR extraction in mixed-phase clouds, the new Ice Selective Inlet (ISI) has been designed and deployed at the Jungfraujoch field site. Small ice crystals are selectively sampled via the inlet with simultaneous counting, sizing and imaging of hydrometeors contained in the cloud by a set of optical particle spectrometers, namely Welas optical particle counters (OPC) and a Particle Phase Discriminator (PPD). The heart of the ISI is a droplet evaporation unit with ice-covered inner walls, resulting in removal of droplets using the Wegener-Bergeron-Findeisen process, while transmitting a relatively high fraction of small ice crystals. The ISI was deployed in the winters of 2013 and 2014 at the high alpine Jungfraujoch site (3580 m.a.s.l) during the intensive CLACE field campaigns. The measurements focused on analysis of the physical and chemical characteristics of IR and the microphysical properties of mixed-phase clouds. A host of aerosol instrumentation was deployed downstream of the ISI, including a Grimm OPC and a scanning mobility particle sizer (SMPS) for number size distribution measurements, as well as a single particle mass spectrometer (ALABAMA; 2013 only), single particle soot photometers (SP2) and a Wideband Integrated Bioaerosol Sensor (WIBS-4) for analysis of the chemical composition, with particular focus on the content of black carbon (BC) and biological particles in IR. Corresponding instrumentation sampled through a total aerosol inlet. By comparing observations from the ISI with those from the total inlet the characteristics of ice residuals relative to the total aerosol could be established. First results from these analyses will be presented.

The impact of physical and mental tasks on pilot mental workoad

NASA Technical Reports Server (NTRS)

Berg, S. L.; Sheridan, T. B.

1986-01-01

Seven instrument-rated pilots with a wide range of backgrounds and experience levels flew four different scenarios on a fixed-base simulator. The Baseline scenario was the simplest of the four and had few mental and physical tasks. An activity scenario had many physical but few mental tasks. The Planning scenario had few physical and many mental taks. A Combined scenario had high mental and physical task loads. The magnitude of each pilot's altitude and airspeed deviations was measured, subjective workload ratings were recorded, and the degree of pilot compliance with assigned memory/planning tasks was noted. Mental and physical performance was a strong function of the manual activity level, but not influenced by the mental task load. High manual task loads resulted in a large percentage of mental errors even under low mental task loads. Although all the pilots gave similar subjective ratings when the manual task load was high, subjective ratings showed greater individual differences with high mental task loads. Altitude or airspeed deviations and subjective ratings were most correlated when the total task load was very high. Although airspeed deviations, altitude deviations, and subjective workload ratings were similar for both low experience and high experience pilots, at very high total task loads, mental performance was much lower for the low experience pilots.

Tripartite counterfactual entanglement distribution.

PubMed

Chen, Yuanyuan; Gu, Xuemei; Jiang, Dong; Xie, Ling; Chen, Lijun

2015-08-10

We propose two counterfactual schemes for tripartite entanglement distribution without any physical particles travelling through the quantum channel. One scheme arranges three participators to connect with the absorption object by using switch. Using the "chained" quantum Zeno effect, three participators can accomplish the task of entanglement distribution with unique counterfactual interference probability. Another scheme uses Michelson-type interferometer to swap two entanglement pairs such that the photons of three participators are entangled. Moreover, the distance of entanglement distribution is doubled as two distant absorption objects are used. We also discuss the implementation issues to show that the proposed schemes can be realized with current technology.

SLAC Library - Online Particle Physics Information

Science.gov Websites

Background Knowledge Particle Physics Lessons and Activities Astronomy and Astrophysics Lessons and Online Particle Physics Information Compiled by Revised: April, 201 7 This annotated list provides a highly selective set of online resources that are useful to the particle physics community. It

High energy physics at UC Riverside

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1997-07-01

This report discusses progress made for the following two tasks: experimental high energy physics, Task A, and theoretical high energy physics, Task B. Task A1 covers hadron collider physics. Information for Task A1 includes: personnel/talks/publications; D0: proton-antiproton interactions at 2 TeV; SDC: proton-proton interactions at 40 TeV; computing facilities; equipment needs; and budget notes. The physics program of Task A2 has been the systematic study of leptons and hadrons. Information covered for Task A2 includes: personnel/talks/publications; OPAL at LEP; OPAL at LEP200; CMS at LHC; the RD5 experiment; LSND at LAMPF; and budget notes. The research activities of the Theorymore » Group are briefly discussed and a list of completed or published papers for this period is given.« less

Two decades of Mexican particle physics at Fermilab

DOE Office of Scientific and Technical Information (OSTI.GOV)

Roy Rubinstein

2002-12-03

This report is a view from Fermilab of Mexican particle physics at the Laboratory since about 1980; it is not intended to be a history of Mexican particle physics: that topic is outside the expertise of the writer. The period 1980 to the present coincides with the growth of Mexican experimental particle physics from essentially no activity to its current state where Mexican groups take part in experiments at several of the world's major laboratories. Soon after becoming Fermilab director in 1979, Leon Lederman initiated a program to encourage experimental physics, especially experimental particle physics, in Latin America. At themore » time, Mexico had significant theoretical particle physics activity, but none in experiment. Following a visit by Lederman to UNAM in 1981, a conference ''Panamerican Symposium on Particle Physics and Technology'' was held in January 1982 at Cocoyoc, Mexico, with about 50 attendees from Europe, North America, and Latin America; these included Lederman, M. Moshinsky, J. Flores, S. Glashow, J. Bjorken, and G. Charpak. Among the conference outcomes were four subsequent similar symposia over the next decade, and a formal Fermilab program to aid Latin American physics (particularly particle physics); it also influenced a decision by Mexican physicist Clicerio Avilez to switch from theoretical to experimental particle physics. The first physics collaboration between Fermilab and Mexico was in particle theory. Post-docs Rodrigo Huerta and Jose Luis Lucio spent 1-2 years at Fermilab starting in 1981, and other theorists (including Augusto Garcia, Arnulfo Zepeda, Matias Moreno and Miguel Angel Perez) also spent time at the Laboratory in the 1980s.« less

EDITORIAL: Physics competitions Physics competitions

NASA Astrophysics Data System (ADS)

Jordens, H.; Mathelitsch, L.

2011-07-01

International tests on competences, such as TIMSS or PISA, and knowledge of young students have revealed low average scores in many countries, often unexpectedly. One effective measure to increase the average standard of a population is to bring the last third of the group to a higher level. Therefore, many nations put some effort into this activity. This brings the danger that not enough attention is paid to students at the other end, those who are talented. Indeed, it is a very difficult task for a teacher to support the less able and at the same time challenge the gifted students, to lead them to the limits of their abilities and provide for a smooth transition to university study. Physics competitions have been proven to fulfil these last demands to a large degree, and therefore are an important additional and, to some extent, complementary tool for the promotion of talented students. This third special section on physics competitions in European Journal of Physics contains three papers, each dealing with a different form of science contest. The first continues the series of presentations of tasks performed at the International Young Physicists' Tournament, which was held in Vienna in 2011. First place went to the team from Singapore, and they have put their investigation on vertical oscillations of coupled magnets into written form (not required by the tournament, where an oral presentation and a defence and discussion are the central aspects). Their paper shows how rich in physics this problem is, and what level of solutions high-school students can already achieve. Sadly, those responsible for the organization of last year's International Physics Olympiad did not provide us with a report on this competition. This is unfortunate, since the Olympiad in Zagreb was very successful and, in particular, the experimental tasks were creative and demanding. Very similar to the aims and the execution of the Physics Olympiad is the International Olympiad on Astronomy and Astrophysics. Those in charge of the competition give an overview of this relatively young tournament. They give a few examples of theoretical and experimental tasks, and one can see the strong connection between astronomy and physics, between the large scales in the universe and the small scales in particle physics. The third paper introduces a special competition called 'First Step to Nobel Prize in Physics'. It was conceived as a national event in Poland and has gained international reputation and acceptance since 1992. Papers are submitted from young students prior to university and are refereed in the same manner as real research papers. This means that the most important criterion is the originality and novelty of the activity performed in theoretical or experimental physics. The aims of this competition are set out below and can be seen as a credo for all competitions: promotion of scientific interest among young pupils selection and promotion of outstanding pupils enhancing motivation stimulation of school work establishing friendly relations between young physicists.

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

NASA Astrophysics Data System (ADS)

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

2017-12-01

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

Manipulation of long-term dynamics in a colloidal active matter system using speckle light fields

NASA Astrophysics Data System (ADS)

Pince, Ercag; Velu, Sabareesh K. P.; Callegari, Agnese; Elahi, Parviz; Gigan, Sylvain; Volpe, Giovanni; Volpe, Giorgio

Particles undergoing a stochastic motion within a disordered medium is a ubiquitous physical and biological phenomena. Examples can be given from organelles performing tasks in the cytoplasm to large animals moving in patchy environment. Here, we use speckle light fields to study the anomalous diffusion in an active matter system consisting of micron-sized silica particles(diameter 5 μm) and motile bacterial cells (E. coli). The speckle light fields are generated by mode mixing inside a multimode optical fiber where a small amount of incident laser power is needed to obtain an effective disordered optical landscape for the purpose of optical manipulation. We experimentally show how complex potentials contribute to the long-term dynamics of the active matter system and observed an enhanced diffusion of particles interacting with the active bacterial bath in the speckle light fields. We showed that this effect can be tuned and controlled by varying the intensity and the statistical properties of the speckle pattern. Potentially, these results could be of interest for many technological applications, such as the manipulation of microparticles inside optically disordered media of biological interest.

Physical Activity Predicts Performance in an Unpracticed Bimanual Coordination Task.

PubMed

Boisgontier, Matthieu P; Serbruyns, Leen; Swinnen, Stephan P

2017-01-01

Practice of a given physical activity is known to improve the motor skills related to this activity. However, whether unrelated skills are also improved is still unclear. To test the impact of physical activity on an unpracticed motor task, 26 young adults completed the international physical activity questionnaire and performed a bimanual coordination task they had never practiced before. Results showed that higher total physical activity predicted higher performance in the bimanual task, controlling for multiple factors such as age, physical inactivity, music practice, and computer games practice. Linear mixed models allowed this effect of physical activity to be generalized to a large population of bimanual coordination conditions. This finding runs counter to the notion that generalized motor abilities do not exist and supports the existence of a "learning to learn" skill that could be improved through physical activity and that impacts performance in tasks that are not necessarily related to the practiced activity.

Magnetospheric and solar physics observations with the PAMELA experiment

NASA Astrophysics Data System (ADS)

Casolino, M.; Adriani, O.; Ambriola, M.; Barbarino, G. C.; Basili, A.; Bazilevskaja, G. A.; Boezio, M.; Bogomolov, E. A.; Bonechi, L.; Bongi, M.; Bonvicini, V.; Bruno, A.; Cafagna, F.; Campana, D.; Carlson, P.; Castellini, G.; de Marzo, C.; de Pascale, M. P.; de Rosa, G.; de Simone, N.; di Felice, V.; Fedele, D.; Galper, A. M.; Hofverberg, P.; Koldashov, S. V.; Krutkov, S. Yu.; Kvashnin, A. N.; Lundquist, J.; Maksumov, O.; Malvezzi, V.; Marcelli, L.; Menn, W.; Mikhailov, V. V.; Minori, M.; Misin, S.; Mocchiutti, E.; Morselli, A.; Nikonov, N. N.; Orsi, S.; Osteria, G.; Papini, P.; Pearce, M.; Picozza, P.; Ricci, M.; Ricciarini, S. B.; Runtso, M. F.; Russo, S.; Simon, M.; Sparvoli, R.; Spillantini, P.; Stozhkov, Yu. I.; Taddei, E.; Vacchi, A.; Vannuccini, E.; Vasilyev, G. I.; Voronov, S. A.; Yurkin, Y. T.; Zampa, G.; Zampa, N.; Zverev, V. G.

2008-04-01

PAMELA is a satellite-borne experiment designed to make long duration measurements of the cosmic radiation in Low Earth Orbit. It is devoted to the detection of the cosmic-ray spectra in the 100 MeV 300 GeV range with primary scientific goal the measurement of antiproton and positron spectra over the largest energy range ever achieved. Other tasks include the search for antinuclei with unprecedented sensitivity and the measurement of the light nuclear component of cosmic rays. In addition, PAMELA can investigate phenomena connected with solar and Earth physics. The apparatus consists of: a Time of Flight system, a magnetic spectrometer, an electromagnetic imaging calorimeter, a shower tail catcher scintillator, a neutron detector and an anticoincidence system. In this work we present some measurements of galactic, secondary and trapped particles performed in the first months of operation.

Inquiring Minds

Science.gov Websites

Go Science at Fermilab Fermilab and the Higgs Boson Frontiers of Particle Physics Experiments & Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Medicine Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library

Report of the Fermilab ILC Citizens' Task Force

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

Fermi National Accelerator Laboratory convened the ILC Citizens' Task Force to provide guidance and advice to the laboratory to ensure that community concerns and ideas are included in all public aspects of planning and design for a proposed future accelerator, the International Linear Collider. In this report, the members of the Task Force describe the process they used to gather and analyze information on all aspects of the proposed accelerator and its potential location at Fermilab in northern Illinois. They present the conclusions and recommendations they reached as a result of the learning process and their subsequent discussions and deliberations.more » While the Task Force was charged to provide guidance on the ILC, it became clear during the process that the high cost of the proposed accelerator made a near-term start for the project at Fermilab unlikely. Nevertheless, based on a year of extensive learning and dialogue, the Task Force developed a series of recommendations for Fermilab to consider as the laboratory develops all successor projects to the Tevatron. The Task Force recognizes that bringing a next-generation particle physics project to Fermilab will require both a large international effort and the support of the local community. While the Task Force developed its recommendations in response to the parameters of a future ILC, the principles they set forth apply directly to any large project that may be conceived at Fermilab, or at other laboratories, in the future. With this report, the Task Force fulfills its task of guiding Fermilab from the perspective of the local community on how to move forward with a large-scale project while building positive relationships with surrounding communities. The report summarizes the benefits, concerns and potential impacts of bringing a large-scale scientific project to northern Illinois.« less

Physics of Alfvén waves and energetic particles in burning plasmas

NASA Astrophysics Data System (ADS)

Chen, Liu; Zonca, Fulvio

2016-01-01

Dynamics of shear Alfvén waves and energetic particles are crucial to the performance of burning fusion plasmas. This article reviews linear as well as nonlinear physics of shear Alfvén waves and their self-consistent interaction with energetic particles in tokamak fusion devices. More specifically, the review on the linear physics deals with wave spectral properties and collective excitations by energetic particles via wave-particle resonances. The nonlinear physics deals with nonlinear wave-wave interactions as well as nonlinear wave-energetic particle interactions. Both linear as well as nonlinear physics demonstrate the qualitatively important roles played by realistic equilibrium nonuniformities, magnetic field geometries, and the specific radial mode structures in determining the instability evolution, saturation, and, ultimately, energetic-particle transport. These topics are presented within a single unified theoretical framework, where experimental observations and numerical simulation results are referred to elucidate concepts and physics processes.

Final Report for Research in High Energy Physics (University of Hawaii)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Browder, Thomas E.

2013-08-31

Here we present a final report for the DOE award for the University of Hawaii High Energy Physics Group (UHHEPG) for the period from December 1, 2009 to May 31, 2013 (including a period of no-cost extension). The high energy physics (HEP) group at the University of Hawaii (UH) has been engaged in experiments at the intensity frontier studying flavor physics (Task A: Belle, Belle-II and Task B: BES) and neutrinos (Task C: SuperK, LBNE, Double Chooz, DarkSide, and neutrino R\\&D). On the energy frontier, new types of pixel detectors were developed for upgrades of the ATLAS experiment at themore » LHC (Task D). On the cosmic frontier, there were investigations of ultra high-energy neutrino astrophysics and the highest energy cosmic rays using special radio detection techniques (Task E: AMBER, ANITA R\\&D) and results of the analysis of ANITA data. In addition, we have developed new types of sophisticated and cutting edge instrumentation based on novel ``oscilloscope on a chip'' electronics (Task F). Theoretical physics research (Task G) is phenomenologically oriented and has studied experimental consequences of existing and proposed new theories relevant to the energy, cosmic and intensity frontiers. The senior investigators for proposal were T. E. Browder (Task A), F. A. Harris (Task B), P. Gorham (Task E), J. Kumar (Task G), J. Maricic (Task C), J. G. Learned (Task C), S. Pakvasa (Task G), S. Parker (Task D), S. Matsuno (Task C), X. Tata (Task G) and G. S. Varner (Tasks F, A, E).« less

A Compendium of the Physiological Demands of the 32 Critical Physically Demanding Tasks of Combat Arms Soldiers

DTIC Science & Technology

As part of the U.S. Army Physical Demands Study (which led to the development of the Occupational Physical Assessment Test (OPAT)), 32 physically ...demanding tasks were identified as being critical to combat arms soldiers. In order to identify the most physically demanding of those tests, data were...comprehensive reference of the physiological demands of the critical physically demanding tasks of combat arms Soldiers.

Do Personal Factors or Types of Physical Tasks Predict Workplace Injury?

PubMed

Oranye, Nelson Ositadimma; Wallis, Bernadine; Roer, Kim; Archer-Heese, Gail; Aguilar, Zaklina

2016-04-01

Occupational health research has shown that certain worker and job characteristics are risk factors for workplace injuries. Workers who engage in physically demanding jobs, especially those jobs that involve repetitive motion, are at greater risk for work-related musculoskeletal disorders (WMSD). These risks are particularly prevalent in the health care sector. It is often reported that nurses are at higher risk of workplace musculoskeletal injury than other health care workers due to frequent lifting and transfer of patients and the prevalence of workplace violence. However, many analyses of the physical requirements of jobs do not consider the modifying effect of time spent on a physical task and the risk of WMSD. This study compared the risks of WMSD among workers in health care facilities based on the type of physical tasks and amount of time workers spent on such tasks. Workers who worked longer on a physical task reported more WMSD than those who spent less time on the same physical task. The risk of WMSD was twice as high (odds ratio [OR] = 2.3) among workers who sit less than 2 hours each day compared with those who sit longer. This study found that physical tasks associated with health care jobs and the amount of time spent on these tasks constitutes serious risk factors for WMSD. © 2016 The Author(s).

Effects of Gait Self-Efficacy and Lower-Extremity Physical Function on Dual-Task Performance in Older Adults

PubMed Central

Banducci, Sarah E.; Daugherty, Ana M.; Fanning, Jason; Awick, Elizabeth A.; Porter, Gwenndolyn C.; Burzynska, Agnieszka; Shen, Sa; Kramer, Arthur F.; McAuley, Edward

2017-01-01

Objectives. Despite evidence of self-efficacy and physical function's influences on functional limitations in older adults, few studies have examined relationships in the context of complex, real-world tasks. The present study tested the roles of self-efficacy and physical function in predicting older adults' street-crossing performance in single- and dual-task simulations. Methods. Lower-extremity physical function, gait self-efficacy, and street-crossing success ratio were assessed in 195 older adults (60–79 years old) at baseline of a randomized exercise trial. During the street-crossing task, participants walked on a self-propelled treadmill in a virtual reality environment. Participants crossed the street without distraction (single-task trials) and conversed on a cell phone (dual-task trials). Structural equation modeling was used to test hypothesized associations independent of demographic and clinical covariates. Results. Street-crossing performance was better on single-task trials when compared with dual-task trials. Direct effects of self-efficacy and physical function on success ratio were observed in dual-task trials only. The total effect of self-efficacy was significant in both conditions. The indirect path through physical function was evident in the dual-task condition only. Conclusion. Physical function can predict older adults' performance on high fidelity simulations of complex, real-world tasks. Perceptions of function (i.e., self-efficacy) may play an even greater role. The trial is registered with United States National Institutes of Health ClinicalTrials.gov (ID: NCT01472744; Fit & Active Seniors Trial). PMID:28255557

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, D.

The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences betweenmore » particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to provide higher levels of local tumor control and improved normal tissue sparing will be discussed. Learning Objectives: To assess whether the current practice of a constant RBE of 1.1 should be revised or maintained in proton therapy and to evaluate the potential clinical consequences of delivering RBE-weighted dose distributions based on variable RBE To review current research on biological models used to predict the increased biological effectiveness of proton and carbon ions to help move towards a practical understanding and implementation of biological optimization in particle therapy To discuss potential differences in biological mechanisms between photons and charged particles (light and heavy ions) that could impact clinical cancer therapy H. Paganetti, NCI U19 CA21239D. Grosshans, Our research is supported by the NCIK. Held, Funding Support: National Cancer Institute of the National Institutes of Health, USA, under Award Number R21CA182259 and Federal Share of Program Income Earned by Massachusetts General Hospital on C06CA059267, Proton Therapy Research and Treatment Center.« less

Fermilab | Science at Fermilab | Experiments & Projects | Energy Frontier

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Go Science at Fermilab Fermilab and the Higgs Boson Frontiers of Particle Physics Experiments & Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Medicine Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library

Fermilab | Science at Fermilab | Experiments & Projects

Science.gov Websites

Go Science at Fermilab Fermilab and the Higgs Boson Frontiers of Particle Physics Experiments & Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Medicine Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library

Nuclear and Particle Physics, Astrophysics and Cosmology : T-2 : LANL

Science.gov Websites

linked in Search T-2, Nuclear and Particle Physics, Astrophysics and Cosmology T-2 Home T Division Focus Areas Nuclear Information Service Nuclear Physics Particle Physics Astrophysics Cosmology CONTACTS Group energy security, heavy ion physics, nuclear astrophysics, physics beyond the standard model, neutrino

The Influence of Communicative Competence on Perceived Task, Social and Physical Attraction.

ERIC Educational Resources Information Center

Duran, Robert L.; Kelly, Lynne

1988-01-01

Examines whether communicative competence influences perceived task, social, and physical attractiveness. Results indicated that communicative competence accounted for 17 percent, 14 percent and 8 percent of the variance in perceived task, social, and physical attractiveness, respectively. (MM)

Motor performance of tongue with a computer-integrated system under different levels of background physical exertion

PubMed Central

Huo, Xueliang; Johnson-Long, Ashley N.; Ghovanloo, Maysam; Shinohara, Minoru

2015-01-01

The purpose of this study was to compare the motor performance of tongue, using Tongue Drive System, to hand operation for relatively complex tasks under different levels of background physical exertion. Thirteen young able-bodied adults performed tasks that tested the accuracy and variability in tracking a sinusoidal waveform, and the performance in playing two video games that require accurate and rapid movements with cognitive processing using tongue and hand under two levels of background physical exertion. Results show additional background physical activity did not influence rapid and accurate displacement motor performance, but compromised the slow waveform tracking and shooting performances in both hand and tongue. Slow waveform tracking performance by the tongue was compromised with an additional motor or cognitive task, but with an additional motor task only for the hand. Practitioner Summary We investigated the influence of task complexity and background physical exertion on the motor performance of tongue and hand. Results indicate the task performance degrades with an additional concurrent task or physical exertion due to the limited attentional resources available for handling both the motor task and background exertion. PMID:24003900

Higgs couplings and new signals from Flavon-Higgs mixing effects within multi-scalar models

NASA Astrophysics Data System (ADS)

Diaz-Cruz, J. Lorenzo; Saldaña-Salazar, Ulises J.

2016-12-01

Testing the properties of the Higgs particle discovered at the LHC and searching for new physics signals, are some of the most important tasks of Particle Physics today. Current measurements of the Higgs couplings to fermions and gauge bosons, seem consistent with the Standard Model, and when taken as a function of the particle mass, should lay on a single line. However, in models with an extended Higgs sector the diagonal Higgs couplings to up-quarks, down-quarks and charged leptons, could lay on different lines, while non-diagonal flavor-violating Higgs couplings could appear too. We describe these possibilities within the context of multi-Higgs doublet models that employ the Froggatt-Nielsen (FN) mechanism to generate the Yukawa hierarchies. Furthermore, one of the doublets can be chosen to be of the inert type, which provides a viable dark matter candidate. The mixing of the Higgs doublets with the flavon field, can provide plenty of interesting signals, including: i) small corrections to the couplings of the SM-like Higgs, ii) exotic signals from the flavon fields, iii) new signatures from the heavy Higgs bosons. These aspects are studied within a specific model with 3 + 1 Higgs doublets and a singlet FN field. Constraints on the model are derived from the study of K and D mixing and the Higgs search at the LHC. For last, the implications from the latter aforementioned constraints to the FCNC top decay t → ch are presented too.

Particle Physics at the University of Pittsburgh Summary Report for Proposal Period FY'09-11

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boudreau, Joe; Dytman, Steven; Mueller, James

Presented is the final summary report for grant DOE-FG02-91ER40646. The HEP group at the University consists of three tasks: B,D and L. Task B supports Pitt's CDF group at the energy frontier which includes Joe Boudreau and Paul Shepard. Work of the group includes Hao Song's thesis on the measurement of the B_c lifetime using exclusive J/psi+pion decays, and an update of the previous B_c semi-leptonic analyses under the supervision of Paul Shepard. Task D supports Pitt's neutrino group at the intensity frontier which includes PIs Dytman, Naples and Paolone. The group also includes postdoctoral research associate Danko, and thesismore » students Isvan (MINOS), Eberly (Minerva ), Ren (Minerva )and Hansen (T2K). This report summarizes their progress on ongoing experiments which are designed to make significant contributions to a detailed understanding of the neutrino mixing matrix. Task L supports Pitt's ATLAS group at the energy frontier and includes investigators Vladimir Savinov, James Mueller and Joe Boudreau. This group contributed both to hardware (calorimeter electronics, Savinov) and to software (Simulation, Detector Description, and Visualization: Boudreau and Mueller; MC generators: Savinov) and a summary of their progress is presented.« less

Particle astrophysics

NASA Technical Reports Server (NTRS)

Sadoulet, Bernard; Cronin, James; Aprile, Elena; Barish, Barry C.; Beier, Eugene W.; Brandenberger, Robert; Cabrera, Blas; Caldwell, David; Cassiday, George; Cline, David B.

1991-01-01

The following scientific areas are reviewed: (1) cosmology and particle physics (particle physics and the early universe, dark matter, and other relics); (2) stellar physics and particles (solar neutrinos, supernovae, and unconventional particle physics); (3) high energy gamma ray and neutrino astronomy; (4) cosmic rays (space and ground observations). Highest scientific priorities for the next decade include implementation of the current program, new initiatives, and longer-term programs. Essential technological developments, such as cryogenic detectors of particles, new solar neutrino techniques, and new extensive air shower detectors, are discussed. Also a certain number of institutional issues (the funding of particle astrophysics, recommended funding mechanisms, recommended facilities, international collaborations, and education and technology) which will become critical in the coming decade are presented.

Feynman-diagrams approach to the quantum Rabi model for ultrastrong cavity QED: stimulated emission and reabsorption of virtual particles dressing a physical excitation

NASA Astrophysics Data System (ADS)

Di Stefano, Omar; Stassi, Roberto; Garziano, Luigi; Frisk Kockum, Anton; Savasta, Salvatore; Nori, Franco

2017-05-01

In quantum field theory, bare particles are dressed by a cloud of virtual particles to form physical particles. The virtual particles affect properties such as the mass and charge of the physical particles, and it is only these modified properties that can be measured in experiments, not the properties of the bare particles. The influence of virtual particles is prominent in the ultrastrong-coupling regime of cavity quantum electrodynamics (QED), which has recently been realised in several condensed-matter systems. In some of these systems, the effective interaction between atom-like transitions and the cavity photons can be switched on or off by external control pulses. This offers unprecedented possibilities for exploring quantum vacuum fluctuations and the relation between physical and bare particles. We consider a single three-level quantum system coupled to an optical resonator. Here we show that, by applying external electromagnetic pulses of suitable amplitude and frequency, each virtual photon dressing a physical excitation in cavity-QED systems can be converted into a physical observable photon, and back again. In this way, the hidden relationship between the bare and the physical excitations can be unravelled and becomes experimentally testable. The conversion between virtual and physical photons can be clearly pictured using Feynman diagrams with cut loops.

Same-sign WW scattering at the LHC: can we discover BSM effects before discovering new states?

NASA Astrophysics Data System (ADS)

Kalinowski, Jan; Kozów, Paweł; Pokorski, Stefan; Rosiek, Janusz; Szleper, Michał; Tkaczyk, Sławomir

2018-05-01

It is possible that measurements of vector boson scattering (VBS) processes at the LHC will reveal disagreement with Standard Model predictions, but no new particles will be observed directly. The task is then to learn as much as possible about the new physics from a VBS analysis carried within the framework of the Effective Field Theory (EFT). In this paper we discuss issues related to the correct usage of the EFT when the WW invariant mass is not directly accessible experimentally, as in purely leptonic W decay channels. Strategies for future data analyses in case such scenario indeed occurs are proposed.

Effect of Melt Convection at Various Gravity Levels and Orientations on the Forces Acting on a Large Spherical Particle in the Vicinity of a Solidification Interface

NASA Technical Reports Server (NTRS)

Bune, Andris V.; Sen, Subhayu; Mukherjee, Sundeep; Catalina, Adrian; Stefanescu, Doru M.

2000-01-01

Numerical modeling was Undertaken to analyze the influence of both radial and axial thermal gradients on convection patterns and velocities claiming solidification of pure Al and an Al-4 wt% Cu alloy. The objective of the numerical task was to predict the influence of convective velocity on an insoluble particle near a solid/liquid (s/l) interface. These predictions were then be used to define the minimum gravity level (q) required to investigate the fundamental physics of interactions between a particle and a s/l interface. This is an ongoing NASA founded flight experiment entitled "particle engulfment and pushing by solidifying interfaces (PEP)". Steady-state calculations were performed for different gravity levels and orientations with respect to the gravity vector The furnace configuration used in this analysis is the quench module insert (QMI-1) proposed for the Material Science Research Facility (MSRF) on board the International Space Station (ISS). The general model of binary alloy solidification was based on the finite element code FIDAP. At a low g level of 10(exp -4) g(sub o) (g(sub o) = 9.8 m/square s) maximum melt convection was obtained for an orientation of 90 deg. Calculations showed that even for this worst case orientation the dominant forces acting on the particle are the fundamental drag and interfacial forces.

WE-FG-BRB-00: The Challenges of Predicting RBE Effects in Particle Therapy and Opportunities for Improving Cancer Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences betweenmore » particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to provide higher levels of local tumor control and improved normal tissue sparing will be discussed. Learning Objectives: To assess whether the current practice of a constant RBE of 1.1 should be revised or maintained in proton therapy and to evaluate the potential clinical consequences of delivering RBE-weighted dose distributions based on variable RBE To review current research on biological models used to predict the increased biological effectiveness of proton and carbon ions to help move towards a practical understanding and implementation of biological optimization in particle therapy To discuss potential differences in biological mechanisms between photons and charged particles (light and heavy ions) that could impact clinical cancer therapy H. Paganetti, NCI U19 CA21239D. Grosshans, Our research is supported by the NCIK. Held, Funding Support: National Cancer Institute of the National Institutes of Health, USA, under Award Number R21CA182259 and Federal Share of Program Income Earned by Massachusetts General Hospital on C06CA059267, Proton Therapy Research and Treatment Center.« less

WE-FG-BRB-04: RBEs for Human Lung Cancer Cells Exposed to Protons and Heavier Ions: Implications for Clinical Use of Charged Particles in Cancer Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Held, K.

The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences betweenmore » particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to provide higher levels of local tumor control and improved normal tissue sparing will be discussed. Learning Objectives: To assess whether the current practice of a constant RBE of 1.1 should be revised or maintained in proton therapy and to evaluate the potential clinical consequences of delivering RBE-weighted dose distributions based on variable RBE To review current research on biological models used to predict the increased biological effectiveness of proton and carbon ions to help move towards a practical understanding and implementation of biological optimization in particle therapy To discuss potential differences in biological mechanisms between photons and charged particles (light and heavy ions) that could impact clinical cancer therapy H. Paganetti, NCI U19 CA21239D. Grosshans, Our research is supported by the NCIK. Held, Funding Support: National Cancer Institute of the National Institutes of Health, USA, under Award Number R21CA182259 and Federal Share of Program Income Earned by Massachusetts General Hospital on C06CA059267, Proton Therapy Research and Treatment Center.« less

WE-FG-BRB-02: Spatial Mapping of the RBE of Scanned Particle Beams

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grosshans, D.

2016-06-15

The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences betweenmore » particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to provide higher levels of local tumor control and improved normal tissue sparing will be discussed. Learning Objectives: To assess whether the current practice of a constant RBE of 1.1 should be revised or maintained in proton therapy and to evaluate the potential clinical consequences of delivering RBE-weighted dose distributions based on variable RBE To review current research on biological models used to predict the increased biological effectiveness of proton and carbon ions to help move towards a practical understanding and implementation of biological optimization in particle therapy To discuss potential differences in biological mechanisms between photons and charged particles (light and heavy ions) that could impact clinical cancer therapy H. Paganetti, NCI U19 CA21239D. Grosshans, Our research is supported by the NCIK. Held, Funding Support: National Cancer Institute of the National Institutes of Health, USA, under Award Number R21CA182259 and Federal Share of Program Income Earned by Massachusetts General Hospital on C06CA059267, Proton Therapy Research and Treatment Center.« less

Fermilab | Science at Fermilab | Experiments & Projects | Intensity

Science.gov Websites

Search Search Go Science at Fermilab Fermilab and the Higgs Boson Frontiers of Particle Physics and Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Results Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle

Sleep restriction during simulated wildfire suppression: effect on physical task performance.

PubMed

Vincent, Grace; Ferguson, Sally A; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

2015-01-01

To examine the effects of sleep restriction on firefighters' physical task performance during simulated wildfire suppression. Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. There were no differences between the sleep-restricted and control groups in firefighters' task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters' performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters' operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity.

Sleep Restriction during Simulated Wildfire Suppression: Effect on Physical Task Performance

PubMed Central

Vincent, Grace; Ferguson, Sally A.; Tran, Jacqueline; Larsen, Brianna; Wolkow, Alexander; Aisbett, Brad

2015-01-01

Objectives To examine the effects of sleep restriction on firefighters’ physical task performance during simulated wildfire suppression. Methods Thirty-five firefighters were matched and randomly allocated to either a control condition (8-hour sleep opportunity, n = 18) or a sleep restricted condition (4-hour sleep opportunity, n = 17). Performance on physical work tasks was evaluated across three days. In addition, heart rate, core temperature, and worker activity were measured continuously. Rate of perceived and exertion and effort sensation were evaluated during the physical work periods. Results There were no differences between the sleep-restricted and control groups in firefighters’ task performance, heart rate, core temperature, or perceptual responses during self-paced simulated firefighting work tasks. However, the sleep-restricted group were less active during periods of non-physical work compared to the control group. Conclusions Under self-paced work conditions, 4 h of sleep restriction did not adversely affect firefighters’ performance on physical work tasks. However, the sleep-restricted group were less physically active throughout the simulation. This may indicate that sleep-restricted participants adapted their behaviour to conserve effort during rest periods, to subsequently ensure they were able to maintain performance during the firefighter work tasks. This work contributes new knowledge to inform fire agencies of firefighters’ operational capabilities when their sleep is restricted during multi-day wildfire events. The work also highlights the need for further research to explore how sleep restriction affects physical performance during tasks of varying duration, intensity, and complexity. PMID:25615988

Health and Human Services Cluster. Task Analyses. Physical Therapist Aide and Physical Therapist Assistant. A Competency-Based Curriculum Guide.

ERIC Educational Resources Information Center

Henrico County Public Schools, Glen Allen, VA. Virginia Vocational Curriculum and Resource Center.

Developed in Virginia, this publication contains task analysis guides to support selected tech prep programs that prepare students for careers in the health and human services cluster. Occupations profiled are physical therapist aide and physical therapist assistant. Each guide contains the following elements: (1) an occupational task list derived…

Applications of Nuclear and Particle Physics Technology: Particles & Detection — A Brief Overview

NASA Astrophysics Data System (ADS)

Weisenberger, Andrew G.

A brief overview of the technology applications with significant societal benefit that have their origins in nuclear and particle physics research is presented. It is shown through representative examples that applications of nuclear physics can be classified into two basic areas: 1) applying the results of experimental nuclear physics and 2) applying the tools of experimental nuclear physics. Examples of the application of the tools of experimental nuclear and particle physics research are provided in the fields of accelerator and detector based technologies namely synchrotron light sources, nuclear medicine, ion implantation and radiation therapy.

Particle Accelerators Test Cosmological Theory.

ERIC Educational Resources Information Center

Schramm, David N.; Steigman, Gary

1988-01-01

Discusses the symbiotic relationship of cosmology and elementary-particle physics. Presents a brief overview of particle physics. Explains how cosmological considerations set limits on the number of types of elementary particles. (RT)

An Evaluation of the Particle Physics Masterclass as a Context for Student Learning about the Nature of Science

ERIC Educational Resources Information Center

Wadness, Michael J.

2010-01-01

This dissertation addresses the research question: To what extent do secondary school science students attending the U.S. Particle Physics Masterclass change their view of the nature of science (NOS)? The U.S. Particle Physics Masterclass is a physics outreach program run by QuarkNet, a national organization of secondary school physics teachers…

An occupational exposure assessment for engineered nanoparticles used in semiconductor fabrication.

PubMed

Shepard, Michele Noble; Brenner, Sara

2014-03-01

Engineered nanoparticles of alumina, amorphous silica, and ceria are used in semiconductor device fabrication during wafer polishing steps referred to as 'chemical mechanical planarization' (CMP). Some metal oxide nanoparticles can impact the biological response of cells and organ systems and may cause adverse health effects; additional research is necessary to better understand potential risks from nanomaterial applications and occupational exposure scenarios. This study was conducted to assess potential airborne exposures to nanoparticles and agglomerates using direct-reading instruments and filter-based samples to characterize workplace aerosols by particle number, mass, size, composition, and morphology. Sampling was repeated for tasks in three work areas (fab, subfab, wastewater treatment) at a facility using engineered nanoparticles for CMP. Real-time measurements were collected using a condensation particle counter (CPC), optical particle counter, and scanning mobility particle spectrometer (SMPS). Filter-based samples were analyzed for total mass or the respirable fraction, and for specific metals of interest. Additional air sample filters were analyzed by transmission electron microscopy with energy dispersive x-ray spectroscopy (TEM/EDX) for elemental identification and to provide data on particle size, morphology, and concentration. Peak concentrations measured on the CPC ranged from 1 to 16 particles per cubic centimeter (P cm(-3)) for background and from 4 to 74 P cm(-3) during tasks sampled in the fab; from 1 to 60 P cm(-3) for background and from 3 to 84 P cm(-3) for tasks sampled in the subfab; and from 1160 to 45 894 P cm(-3) for background and from 1710 to 45 519 P cm(-3) during wastewater treatment system filter change tasks. Significant variability was seen among the repeated task measurements and among background comparisons in each area. Several data analysis methods were used to compare each set of task and background measurements. Increased concentrations of respirable particles were identified for some tasks sampled in each work area, although of relatively low magnitude and inconsistently among repeated measurements for specific tasks. Measurements with a portable SMPS indicated that nanoparticle number concentrations (channels 11.5-115.5nm) increased above background levels by 3.2 P cm(-3) during CMP tool set-up in the fab area but were not elevated when changing filters for the CMP wastewater treatment system. All results from mass concentration analysis were below the limits of detection. Characterization by TEM/EDX identified structures containing the elements of interest (Al, Si), primarily as agglomerates or aggregates in the 100-1000nm size range. Although health-based occupational exposure limits have not been established for nanoscale alumina, silica, or ceria, the measured concentrations by number and mass were below currently proposed benchmarks or reference values for poorly soluble low-toxicity nanoparticles.

Engineering and Physics Optimization of Breed and Burn Fast Reactor Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Michael J. Driscoll; Pavel Hejzlar; Peter Yarsky

2005-12-09

This project is organized under four major tasks (each of which has two or more subtasks) with contributions among the three collaborating organizations (MIT, INEEL and ANL-West): Task A: Core Physics and Fuel Cycle; Task B: Core Thermal Hydraulics; Task C: Plant Design Task; and D: Fuel Design.

The influence of human physical activity and contaminated clothing type on particle resuspension.

PubMed

McDonagh, A; Byrne, M A

2014-01-01

A study was conducted to experimentally quantify the influence of three variables on the level of resuspension of hazardous aerosol particles from clothing. Variables investigated include physical activity level (two levels, low and high), surface type (four different clothing material types), and time i.e. the rate at which particles resuspend. A mixture of three monodisperse tracer-labelled powders, with median diameters of 3, 5, and 10 microns, was used to "contaminate" the samples, and the resuspended particles were analysed in real-time using an Aerodynamic Particle Sizer (APS), and also by Neutron Activation Analysis (NAA). The overall finding was that physical activity resulted in up to 67% of the contamination deposited on clothing being resuspended back into the air. A detailed examination of the influence of physical activity level on resuspension, from NAA, revealed that the average resuspended fraction (RF) of particles at low physical activity was 28 ± 8%, and at high physical activity was 30 ± 7%, while the APS data revealed a tenfold increase in the cumulative mass of airborne particles during high physical activity in comparison to that during low physical activity. The results also suggest that it is not the contaminated clothing's fibre type which influences particle resuspension, but the material's weave pattern (and hence the material's surface texture). Investigation of the time variation in resuspended particle concentrations indicated that the data were separable into two distinct regimes: the first (occurring within the first 1.5 min) having a high, positive rate of change of airborne particle concentration relative to the second regime. The second regime revealed a slower rate of change of particle concentration and remained relatively unchanged for the remainder of each resuspension event. Copyright © 2013 Elsevier Ltd. All rights reserved.

Identifying the critical physical demanding tasks of paramedic work: Towards the development of a physical employment standard.

PubMed

Fischer, Steven L; Sinden, Kathryn E; MacPhee, Renee S

2017-11-01

Public safety related occupations including police, fire and military commonly apply physical employment standard (PES) to facilitate job matching, an approach to evaluate if candidates demonstrate acceptable physical capabilities as required to perform the job safely and effectively. In Canada, paramedics remain as one of the few public safety occupations without an evidence-based, validated PES. The purpose of this study was to document and describe the physical demands of paramedic work and to identify the most physically demanding tasks. These outcomes are essential to inform the design and development of an evidence-based PES for the paramedic sector. Physical demands of paramedic work were documented and described using a direct observation-based task analysis technique. Five paramedic's were trained to document the physical demands of their work, then applied their training to observe more than 90 calls over the course of 20 full 12-h work shifts. Physical demands data were then listed in a survey, administered service-wide, where 155 frontline paramedics identified critically demanding tasks and rank-ordered physical demands from not physically demanding to very strongly demanding. Critically important and physically demanding tasks were identified such as: transferring a patient; loading or unloading a stretcher in to or out of the ambulance; performing CPR; and, raising and lowering a stretcher. It is important that a paramedic-based PES evaluate a candidate's physical capabilities to perform the critical and physically demanding tasks identified in this study. Copyright © 2017 Elsevier Ltd. All rights reserved.

Matrix Factorizations at Scale: a Comparison of Scientific Data Analytics in Spark and C+MPI Using Three Case Studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gittens, Alex; Devarakonda, Aditya; Racah, Evan

We explore the trade-offs of performing linear algebra using Apache Spark, compared to traditional C and MPI implementations on HPC platforms. Spark is designed for data analytics on cluster computing platforms with access to local disks and is optimized for data-parallel tasks. We examine three widely-used and important matrix factorizations: NMF (for physical plausibility), PCA (for its ubiquity) and CX (for data interpretability). We apply these methods to 1.6TB particle physics, 2.2TB and 16TB climate modeling and 1.1TB bioimaging data. The data matrices are tall-and-skinny which enable the algorithms to map conveniently into Spark’s data parallel model. We perform scalingmore » experiments on up to 1600 Cray XC40 nodes, describe the sources of slowdowns, and provide tuning guidance to obtain high performance.« less

Incremental update of electrostatic interactions in adaptively restrained particle simulations.

PubMed

Edorh, Semeho Prince A; Redon, Stéphane

2018-04-06

The computation of long-range potentials is one of the demanding tasks in Molecular Dynamics. During the last decades, an inventive panoply of methods was developed to reduce the CPU time of this task. In this work, we propose a fast method dedicated to the computation of the electrostatic potential in adaptively restrained systems. We exploit the fact that, in such systems, only some particles are allowed to move at each timestep. We developed an incremental algorithm derived from a multigrid-based alternative to traditional Fourier-based methods. Our algorithm was implemented inside LAMMPS, a popular molecular dynamics simulation package. We evaluated the method on different systems. We showed that the new algorithm's computational complexity scales with the number of active particles in the simulated system, and is able to outperform the well-established Particle Particle Particle Mesh (P3M) for adaptively restrained simulations. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

The application of subjective job task analysis techniques in physically demanding occupations: evidence for the presence of self-serving bias.

PubMed

Lee-Bates, Benjamin; Billing, Daniel C; Caputi, Peter; Carstairs, Greg L; Linnane, Denise; Middleton, Kane

2017-09-01

The aim of this study was to determine if perceptions of physically demanding job tasks are biased by employee demographics and employment profile characteristics including: age, sex, experience, length of tenure, rank and if they completed or supervised a task. Surveys were administered to 427 Royal Australian Navy personnel who characterised 33 tasks in terms of physical effort, importance, frequency, duration and vertical/horizontal distance travelled. Results showed no evidence of bias resulting from participant characteristics, however participants who were actively involved in both task participation and supervision rated these tasks as more important than those involved only in the supervision of that task. This may indicate self-serving bias in which participants that are more actively involved in a task had an inflated perception of that task's importance. These results have important implications for the conduct of job task analyses, especially the use of subjective methodologies in the development of scientifically defensible physical employment standards. Practitioner Summary: To examine the presence of systematic bias in subjective job task analysis methodologies, a survey was conducted on a sample of Royal Australian Navy personnel. The relationship between job task descriptions and participant's demographic and job profile characteristics revealed the presence of self-serving bias affecting perceptions of task importance.

Perceived Difficulty with Physical Tasks, Lifestyle, and Physical Performance in Obese Children

PubMed Central

D'Amico, Osvaldo; Sticco, Maura; Nugnes, Rosa; Mozzillo, Enza; Franzese, Adriana

2014-01-01

We estimated perceived difficulty with physical tasks, lifestyle, and physical performance in 382 children and adolescents (163 obese, 54 overweight, and 165 normal-weight subjects) and the relationship between perceived physical difficulties and sports participation, sedentary behaviors, or physical performance. Perceived difficulty with physical tasks and lifestyle habits was assessed by interview using a structured questionnaire, while physical performance was assessed through the six-minute walking test (6MWT). Obese children had higher perceived difficulty with several activities of daily living, were less engaged in sports, and had lower physical performance than normal-weight or overweight children; on the contrary, they did not differ with regard to time spent in sedentary behaviors. Perceived difficulty in running and hopping negatively predicted sports participation (P < 0.05 and <0.01, resp.), while perceived difficulty in almost all physical activities negatively predicted the 6MWT, independently of BMI (P < 0.01). Our results indicate that perception of task's difficulty level may reflect an actual difficulty in obese children. These findings may have practical implications for approaching physical activity in obese children. Exploring both the perception of a task's difficulty level and physical performance may be useful to design exercise programs that allow safe and successful participation. PMID:25105139

Task Force on Teacher Education in Physics: Findings and Recommendations

NASA Astrophysics Data System (ADS)

Otero, Valerie

2010-03-01

In response to the national crisis in science education, including low performance in high school physical science and a critical shortage of highly qualified physics teachers, a National Task Force was convened to investigate the state of physics education in the United States. The Task Force spent one year collecting data from over 900 universities and conducting site visits at 13 universities that were identified as ``high producers'' of physics teachers. The final report of the Task Force will be published early in 2010 and will highlight the findings and recommendations that resulted from the study. In this presentation, the main findings and recommendations will be presented along with selected case studies that illustrate exemplary practices in physics and education departments.

Associations between physical function, dual-task performance and cognition in patients with mild Alzheimer's disease.

PubMed

Sobol, Nanna Aue; Hoffmann, Kristine; Vogel, Asmus; Lolk, Annette; Gottrup, Hanne; Høgh, Peter; Hasselbalch, Steen G; Beyer, Nina

2016-11-01

Alzheimer's disease (AD) causes a gradual decline in cognition, limitations of dual-tasking and physical function leading to total dependence. Hence, information about the interaction between physical function, dual-task performance and cognition may lead to new treatment strategies with the purpose of preserving function and quality of life. The objective of this study was to investigate the associations between physical function, dual-task performance and cognition in community-dwelling patients with mild AD. Baseline results from 185 participants (50-90 years old) in the single blinded multicenter RCT 'ADEX' (Alzheimer's disease: the effect of physical exercise) were used. Assessments included tests of physical function: 400-m walk test, 10-m walk test, Timed Up and Go test and 30-s chair stand test; dual-task performance, i.e., 10-m walk while counting backwards from 50 or naming the months backwards; and cognition, i.e., Mini Mental State Examination, Symbol Digit Modalities Test, the Stroop Color and Word Test, and Lexical verbal fluency test. Results in the 30-s chair stand test correlated significantly with all tests of cognition (r = .208-.242) while the other physical function tests only randomly correlated with tests of cognition. Results in the dual-task counting backwards correlated significantly with results in all tests of cognition (r = .259-.388), which accounted for 7%-15% of the variation indicating that a faster time to complete dual-task performance was associated with better cognitive performance. The evidence of the associations between physical function, dual-task performance and cognition is important when creating new rehabilitation interventions to patients with mild AD.

Task Lists for Health Occupations. Radiologic Aide. Activity Aide. Optometric Assistant. Physical Therapy Aide. Education for Employment Task Lists.

ERIC Educational Resources Information Center

Lathrop, Janice

These task lists contain employability skills and tasks for the following health occupations: radiologic aide, activity aide, physical therapy aide, and optometric assistant. The duties and tasks found in these lists form the basis of instructional content for secondary, postsecondary, and adult occupational training programs. Employability skills…

RIP-REMOTE INTERACTIVE PARTICLE-TRACER

NASA Technical Reports Server (NTRS)

Rogers, S. E.

1994-01-01

Remote Interactive Particle-tracing (RIP) is a distributed-graphics program which computes particle traces for computational fluid dynamics (CFD) solution data sets. A particle trace is a line which shows the path a massless particle in a fluid will take; it is a visual image of where the fluid is going. The program is able to compute and display particle traces at a speed of about one trace per second because it runs on two machines concurrently. The data used by the program is contained in two files. The solution file contains data on density, momentum and energy quantities of a flow field at discrete points in three-dimensional space, while the grid file contains the physical coordinates of each of the discrete points. RIP requires two computers. A local graphics workstation interfaces with the user for program control and graphics manipulation, and a remote machine interfaces with the solution data set and performs time-intensive computations. The program utilizes two machines in a distributed mode for two reasons. First, the data to be used by the program is usually generated on the supercomputer. RIP avoids having to convert and transfer the data, eliminating any memory limitations of the local machine. Second, as computing the particle traces can be computationally expensive, RIP utilizes the power of the supercomputer for this task. Although the remote site code was developed on a CRAY, it is possible to port this to any supercomputer class machine with a UNIX-like operating system. Integration of a velocity field from a starting physical location produces the particle trace. The remote machine computes the particle traces using the particle-tracing subroutines from PLOT3D/AMES, a CFD post-processing graphics program available from COSMIC (ARC-12779). These routines use a second-order predictor-corrector method to integrate the velocity field. Then the remote program sends graphics tokens to the local machine via a remote-graphics library. The local machine interprets the graphics tokens and draws the particle traces. The program is menu driven. RIP is implemented on the silicon graphics IRIS 3000 (local workstation) with an IRIX operating system and on the CRAY2 (remote station) with a UNICOS 1.0 or 2.0 operating system. The IRIS 4D can be used in place of the IRIS 3000. The program is written in C (67%) and FORTRAN 77 (43%) and has an IRIS memory requirement of 4 MB. The remote and local stations must use the same user ID. PLOT3D/AMES unformatted data sets are required for the remote machine. The program was developed in 1988.

Neural Networks for Modeling and Control of Particle Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edelen, A. L.; Biedron, S. G.; Chase, B. E.

Myriad nonlinear and complex physical phenomena are host to particle accelerators. They often involve a multitude of interacting systems, are subject to tight performance demands, and should be able to run for extended periods of time with minimal interruptions. Often times, traditional control techniques cannot fully meet these requirements. One promising avenue is to introduce machine learning and sophisticated control techniques inspired by artificial intelligence, particularly in light of recent theoretical and practical advances in these fields. Within machine learning and artificial intelligence, neural networks are particularly well-suited to modeling, control, and diagnostic analysis of complex, nonlinear, and time-varying systems,more » as well as systems with large parameter spaces. Consequently, the use of neural network-based modeling and control techniques could be of significant benefit to particle accelerators. For the same reasons, particle accelerators are also ideal test-beds for these techniques. Moreover, many early attempts to apply neural networks to particle accelerators yielded mixed results due to the relative immaturity of the technology for such tasks. For the purpose of this paper is to re-introduce neural networks to the particle accelerator community and report on some work in neural network control that is being conducted as part of a dedicated collaboration between Fermilab and Colorado State University (CSU). We also describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.« less

Neural Networks for Modeling and Control of Particle Accelerators

NASA Astrophysics Data System (ADS)

Edelen, A. L.; Biedron, S. G.; Chase, B. E.; Edstrom, D.; Milton, S. V.; Stabile, P.

2016-04-01

Particle accelerators are host to myriad nonlinear and complex physical phenomena. They often involve a multitude of interacting systems, are subject to tight performance demands, and should be able to run for extended periods of time with minimal interruptions. Often times, traditional control techniques cannot fully meet these requirements. One promising avenue is to introduce machine learning and sophisticated control techniques inspired by artificial intelligence, particularly in light of recent theoretical and practical advances in these fields. Within machine learning and artificial intelligence, neural networks are particularly well-suited to modeling, control, and diagnostic analysis of complex, nonlinear, and time-varying systems, as well as systems with large parameter spaces. Consequently, the use of neural network-based modeling and control techniques could be of significant benefit to particle accelerators. For the same reasons, particle accelerators are also ideal test-beds for these techniques. Many early attempts to apply neural networks to particle accelerators yielded mixed results due to the relative immaturity of the technology for such tasks. The purpose of this paper is to re-introduce neural networks to the particle accelerator community and report on some work in neural network control that is being conducted as part of a dedicated collaboration between Fermilab and Colorado State University (CSU). We describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.

Neural Networks for Modeling and Control of Particle Accelerators

DOE PAGES

Edelen, A. L.; Biedron, S. G.; Chase, B. E.; ...

2016-04-01

Myriad nonlinear and complex physical phenomena are host to particle accelerators. They often involve a multitude of interacting systems, are subject to tight performance demands, and should be able to run for extended periods of time with minimal interruptions. Often times, traditional control techniques cannot fully meet these requirements. One promising avenue is to introduce machine learning and sophisticated control techniques inspired by artificial intelligence, particularly in light of recent theoretical and practical advances in these fields. Within machine learning and artificial intelligence, neural networks are particularly well-suited to modeling, control, and diagnostic analysis of complex, nonlinear, and time-varying systems,more » as well as systems with large parameter spaces. Consequently, the use of neural network-based modeling and control techniques could be of significant benefit to particle accelerators. For the same reasons, particle accelerators are also ideal test-beds for these techniques. Moreover, many early attempts to apply neural networks to particle accelerators yielded mixed results due to the relative immaturity of the technology for such tasks. For the purpose of this paper is to re-introduce neural networks to the particle accelerator community and report on some work in neural network control that is being conducted as part of a dedicated collaboration between Fermilab and Colorado State University (CSU). We also describe some of the challenges of particle accelerator control, highlight recent advances in neural network techniques, discuss some promising avenues for incorporating neural networks into particle accelerator control systems, and describe a neural network-based control system that is being developed for resonance control of an RF electron gun at the Fermilab Accelerator Science and Technology (FAST) facility, including initial experimental results from a benchmark controller.« less

Neutron energy determination with a high-purity germanium detector

NASA Technical Reports Server (NTRS)

Beck, Gene A.

1992-01-01

Two areas that are related to planetary gamma-ray spectrometry are investigated. The first task was the investigation of gamma rays produced by high-energy charged particles and their secondaries in planetary surfaces by means of thick target bombardments. The second task was the investigation of the effects of high-energy neutrons on gamma-ray spectral features obtained with high-purity Ge-detectors. For both tasks, as a function of the funding level, the experimental work was predominantly tied to that of other researchers, whenever there was an opportunity to participate in bombardment experiments at large or small accelerators for charged particles.

What's Next for Particle Physics?

NASA Astrophysics Data System (ADS)

White, Martin

2017-10-01

Following the discovery of the Higgs boson in 2012, particle physics has entered its most exciting and crucial period for over 50 years. In this book, I first summarise our current understanding of particle physics, and why this knowledge is almost certainly incomplete. We will then see that the Large Hadron Collider provides the means to search for the next theory of particle physics by performing precise measurements of the Higgs boson, and by looking directly for particles that can solve current cosmic mysteries such as the nature of dark matter. Finally, I will anticipate the next decade of particle physics by placing the Large Hadron Collider within the wider context of other experiments. The results expected over the next ten years promise to transform our understanding of what the Universe is made of and how it came to be.

New generation electron-positron factories

NASA Astrophysics Data System (ADS)

Zobov, Mikhail

2011-09-01

In 2010 we celebrate 50 years since commissioning of the first particle storage ring ADA in Frascati (Italy) that also became the first electron-positron collider in 1964. After that date the particle colliders have increased their intensity, luminosity and energy by several orders of magnitude. Namely, because of the high stored beam currents and high rate of useful physics events (luminosity) the modern electron-positron colliders are called "factories". However, the fundamental physics has required luminosities by 1-2 orders of magnitudes higher with respect to those presently achieved. This task can be accomplished by designing a new generation of factories exploiting the potential of a new collision scheme based on the Crab Waist (CW) collision concept recently proposed and successfully tested at Frascati. In this paper we discuss the performance and limitations of the present generation electron-positron factories and give a brief overview of new ideas and collision schemes proposed for further collider luminosity increase. In more detail we describe the CW collision concept and the results of the crab waist collision tests in DAϕNE, the Italian ϕ-factory. Finally, we briefly describe most advanced projects of the next generation factories based on the CW concept: SuperB in Italy, SuperKEKB in Japan and SuperC-Tau in Russia.

Barriers to success: physical separation optimizes event-file retrieval in shared workspaces.

PubMed

Klempova, Bibiana; Liepelt, Roman

2017-07-08

Sharing tasks with other persons can simplify our work and life, but seeing and hearing other people's actions may also be very distracting. The joint Simon effect (JSE) is a standard measure of referential response coding when two persons share a Simon task. Sequential modulations of the joint Simon effect (smJSE) are interpreted as a measure of event-file processing containing stimulus information, response information and information about the just relevant control-state active in a given social situation. This study tested effects of physical (Experiment 1) and virtual (Experiment 2) separation of shared workspaces on referential coding and event-file processing using a joint Simon task. In Experiment 1, participants performed this task in individual (go-nogo), joint and standard Simon task conditions with and without a transparent curtain (physical separation) placed along the imagined vertical midline of the monitor. In Experiment 2, participants performed the same tasks with and without receiving background music (virtual separation). For response times, physical separation enhanced event-file retrieval indicated by an enlarged smJSE in the joint Simon task with curtain than without curtain (Experiment1), but did not change referential response coding. In line with this, we also found evidence for enhanced event-file processing through physical separation in the joint Simon task for error rates. Virtual separation did neither impact event-file processing, nor referential coding, but generally slowed down response times in the joint Simon task. For errors, virtual separation hampered event-file processing in the joint Simon task. For the cognitively more demanding standard two-choice Simon task, we found music to have a degrading effect on event-file retrieval for response times. Our findings suggest that adding a physical separation optimizes event-file processing in shared workspaces, while music seems to lead to a more relaxed task processing mode under shared task conditions. In addition, music had an interfering impact on joint error processing and more generally when dealing with a more complex task in isolation.

Particle Physics: From School to University.

ERIC Educational Resources Information Center

Barlow, Roger

1992-01-01

Discusses the teaching of particle physics as part of the A-level physics course in British secondary schools. Utilizes the quark model of hadrons and the conceptual kinematics of particle collisions, as examples, to demonstrate practical instructional possibilities in relation to student expectations. (JJK)

From Particle Physics to Medical Applications

NASA Astrophysics Data System (ADS)

Dosanjh, Manjit

2017-06-01

CERN is the world's largest particle physics research laboratory. Since it was established in 1954, it has made an outstanding contribution to our understanding of the fundamental particles and their interactions, and also to the technologies needed to analyse their properties and behaviour. The experimental challenges have pushed the performance of particle accelerators and detectors to the limits of our technical capabilities, and these groundbreaking technologies can also have a significant impact in applications beyond particle physics. In particular, the detectors developed for particle physics have led to improved techniques for medical imaging, while accelerator technologies lie at the heart of the irradiation methods that are widely used for treating cancer. Indeed, many important diagnostic and therapeutic techniques used by healthcare professionals are based either on basic physics principles or the technologies developed to carry out physics research. Ever since the discovery of x-rays by Roentgen in 1895, physics has been instrumental in the development of technologies in the biomedical domain, including the use of ionizing radiation for medical imaging and therapy. Some key examples that are explored in detail in this book include scanners based on positron emission tomography, as well as radiation therapy for cancer treatment. Even the collaborative model of particle physics is proving to be effective in catalysing multidisciplinary research for medical applications, ensuring that pioneering physics research is exploited for the benefit of all.

Let’s have a coffee with the Standard Model of particle physics!

NASA Astrophysics Data System (ADS)

Woithe, Julia; Wiener, Gerfried J.; Van der Veken, Frederik F.

2017-05-01

The Standard Model of particle physics is one of the most successful theories in physics and describes the fundamental interactions between elementary particles. It is encoded in a compact description, the so-called ‘Lagrangian’, which even fits on t-shirts and coffee mugs. This mathematical formulation, however, is complex and only rarely makes it into the physics classroom. Therefore, to support high school teachers in their challenging endeavour of introducing particle physics in the classroom, we provide a qualitative explanation of the terms of the Lagrangian and discuss their interpretation based on associated Feynman diagrams.

Personal exposure to ultrafine particles from PVC welding and concrete work during tunnel rehabilitation.

PubMed

Jørgensen, Rikke Bramming; Buhagen, Morten; Føreland, Solveig

2016-07-01

To investigate the exposure to number concentration of ultrafine particles and the size distribution in the breathing zone of workers during rehabilitation of a subsea tunnel. Personal exposure was measured using a TSI 3091 Fast Mobility Particle Sizer (FMPS), measuring the number concentration of submicrometre particles (including ultrafine particles) and the particle size distribution in the size range 5.6-560 nm. The measurements were performed in the breathing zone of the operators by the use of a conductive silicone tubing. Working tasks studied were operation of the slipforming machine, operations related to finishing the verge, and welding the PVC membrane. In addition, background levels were measured. Arithmetic mean values of ultrafine particles were in the range 6.26×10(5)-3.34×10(6). Vertical PVC welding gave the highest exposure. Horizontal welding was the work task with the highest maximum peak exposure, 8.1×10(7) particles/cm(3). Background concentrations of 4.0×10(4)-3.1×10(5) were found in the tunnel. The mobility diameter at peak particle concentration varied between 10.8 nm during horizontal PVC welding and during breaks and 60.4 nm while finishing the verge. PVC welding in a vertical position resulted in very high exposure of the worker to ultrafine particles compared to other types of work tasks. In evaluations of worker exposure to ultrafine particles, it seems important to distinguish between personal samples taken in the breathing zone of the worker and more stationary work area measurements. There is a need for a portable particle-sizing instrument for measurements of ultrafine particles in working environments. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

LECTURES ON PHYSICS, BIOPHYSICS, AND CHEMISTRY FOR HIGH SCHOOL SCIENCE TEACHERS GIVEN AT THE ERNEST O. LAWRENCE RADIATION LABORATORY, BERKELEY, CALIFORNIA, JUNE-AUGUST 1959

DOE Office of Scientific and Technical Information (OSTI.GOV)

Calhoon, E.C.; Starring, P.W. eds.

1959-08-01

Lectures given at the Ernest 0. Lawrence Radiation Laboratory on physics, biophysics, and chemistry for high school science teachers are presented. Topics covered include a mathematics review, atomic physics, nuclear physics, solid-state physics, elementary particles, antiparticies, design of experiments, high-energy particle accelerators, survey of particle detectors, emulsion as a particle detector, counters used in high-energy physics, bubble chambers, computer programming, chromatography, the transuranium elements, health physics, photosynthesis, the chemistry and physics of virus, the biology of virus, lipoproteins and heart disease, origin and evolution of the solar system, the role of space satellites in gathering astronomical data, and radiation andmore » life in space. (M.C.G.)« less

Dynamic VMs placement for energy efficiency by PSO in cloud computing

NASA Astrophysics Data System (ADS)

Dashti, Seyed Ebrahim; Rahmani, Amir Masoud

2016-03-01

Recently, cloud computing is growing fast and helps to realise other high technologies. In this paper, we propose a hieratical architecture to satisfy both providers' and consumers' requirements in these technologies. We design a new service in the PaaS layer for scheduling consumer tasks. In the providers' perspective, incompatibility between specification of physical machine and user requests in cloud leads to problems such as energy-performance trade-off and large power consumption so that profits are decreased. To guarantee Quality of service of users' tasks, and reduce energy efficiency, we proposed to modify Particle Swarm Optimisation to reallocate migrated virtual machines in the overloaded host. We also dynamically consolidate the under-loaded host which provides power saving. Simulation results in CloudSim demonstrated that whatever simulation condition is near to the real environment, our method is able to save as much as 14% more energy and the number of migrations and simulation time significantly reduces compared with the previous works.

Using link analysis to explore the impact of the physical environment on pharmacist tasks.

PubMed

Lester, Corey A; Chui, Michelle A

2016-01-01

National community pharmacy organizations have been redesigning pharmacies to better facilitate direct patient care. However, evidence suggests that changing the physical layout of a pharmacy prior to understanding how the environment impacts pharmacists' work may not achieve the desired benefits. This study describes an objective method to understanding how the physical layout of the pharmacy may affect how pharmacists perform tasks. Link analysis is a systems engineering method used to describe the influence of the physical environment on task completion. This study used a secondary data set of field notes collected from 9 h of direct observation in one mass-merchandise community pharmacy in the U.S. State, Wisconsin. A node is an individual location in the environment. A link is the movement between two nodes. Tasks were inventoried and task themes identified. The mean, minimum, and maximum number of links needed to complete each task were then determined and used to construct a link table. A link diagram is a graphical display showing the links in conjunction with the physical layout of the pharmacy. A total of 92 unique tasks were identified resulting in 221 links. Tasks were sorted into five themes: patient care activities, insurance issues, verifying prescriptions, filling prescriptions, and other. Insurance issues required the greatest number of links with a mean of 4.75. Verifying prescriptions and performing patient care were the most commonly performed tasks with 36 and 30 unique task occurrences, respectively. Link analysis provides an objective method for identifying how a pharmacist interacts with the physical environment to complete tasks. This method provides designers with useful information to target interventions to improve the effectiveness of pharmacist work. Analysis beyond link analysis should be considered for large scale system redesign. Copyright © 2015 Elsevier Inc. All rights reserved.

Particle and nuclear physics instrumentation and its broad connections

DOE PAGES

Demarteau, Marcel; Lipton, Ron; Nicholson, Howard; ...

2016-12-20

Subatomic physics shares with other basic sciences the need to innovate, invent, and develop tools, techniques, and technologies to carry out its mission to explore the nature of matter, energy, space, and time. In some cases, entire detectors or technologies developed specifically for particle physics research have been adopted by other fields of research or in commercial applications. In most cases, however, the development of new devices and technologies by particle physics for its own research has added value to other fields of research or to applications beneficial to society by integrating them in the existing technologies. Thus, detector researchmore » and development has not only advanced the current state of technology for particle physics, but has often advanced research in other fields of science and has underpinned progress in numerous applications in medicine and national security. At the same time particle physics has profited immensely from developments in industry and applied them to great benefit for the use of particle physics detectors. Finally, this symbiotic relationship has seen strong mutual benefits with sometimes unexpected far reach.« less

Particle and nuclear physics instrumentation and its broad connections

NASA Astrophysics Data System (ADS)

Demarteau, M.; Lipton, R.; Nicholson, H.; Shipsey, I.

2016-10-01

Subatomic physics shares with other basic sciences the need to innovate, invent, and develop tools, techniques, and technologies to carry out its mission to explore the nature of matter, energy, space, and time. In some cases, entire detectors or technologies developed specifically for particle physics research have been adopted by other fields of research or in commercial applications. In most cases, however, the development of new devices and technologies by particle physics for its own research has added value to other fields of research or to applications beneficial to society by integrating them in the existing technologies. Thus, detector research and development has not only advanced the current state of technology for particle physics, but has often advanced research in other fields of science and has underpinned progress in numerous applications in medicine and national security. At the same time particle physics has profited immensely from developments in industry and applied them to great benefit for the use of particle physics detectors. This symbiotic relationship has seen strong mutual benefits with sometimes unexpected far reach.

Particle and nuclear physics instrumentation and its broad connections

DOE Office of Scientific and Technical Information (OSTI.GOV)

Demarteau, Marcel; Lipton, Ron; Nicholson, Howard

Subatomic physics shares with other basic sciences the need to innovate, invent, and develop tools, techniques, and technologies to carry out its mission to explore the nature of matter, energy, space, and time. In some cases, entire detectors or technologies developed specifically for particle physics research have been adopted by other fields of research or in commercial applications. In most cases, however, the development of new devices and technologies by particle physics for its own research has added value to other fields of research or to applications beneficial to society by integrating them in the existing technologies. Thus, detector researchmore » and development has not only advanced the current state of technology for particle physics, but has often advanced research in other fields of science and has underpinned progress in numerous applications in medicine and national security. At the same time particle physics has profited immensely from developments in industry and applied them to great benefit for the use of particle physics detectors. Finally, this symbiotic relationship has seen strong mutual benefits with sometimes unexpected far reach.« less

Manganese Research Health Project (MHRP)

DTIC Science & Technology

2006-01-01

ultrafine particles (or nanoparticles) on health (e.g. Royal Society 2004) and the apparent potential for translocation of these particles along the...evaluate the usefulness of particle counting methods (CPC) in assessing exposure to ultrafine particles in manganese production scenarios. Task 4. Database...R, Kreyling W, Cox C (2004). Translocation of Inhaled Ultrafine Particles to the Brain. Inhalation toxicology; 16:437 - 445 Ritchie P, Cherrie J

Tri-track: free software for large-scale particle tracking.

PubMed

Vallotton, Pascal; Olivier, Sandra

2013-04-01

The ability to correctly track objects in time-lapse sequences is important in many applications of microscopy. Individual object motions typically display a level of dynamic regularity reflecting the existence of an underlying physics or biology. Best results are obtained when this local information is exploited. Additionally, if the particle number is known to be approximately constant, a large number of tracking scenarios may be rejected on the basis that they are not compatible with a known maximum particle velocity. This represents information of a global nature, which should ideally be exploited too. Some time ago, we devised an efficient algorithm that exploited both types of information. The tracking task was reduced to a max-flow min-cost problem instance through a novel graph structure that comprised vertices representing objects from three consecutive image frames. The algorithm is explained here for the first time. A user-friendly implementation is provided, and the specific relaxation mechanism responsible for the method's effectiveness is uncovered. The software is particularly competitive for complex dynamics such as dense antiparallel flows, or in situations where object displacements are considerable. As an application, we characterize a remarkable vortex structure formed by bacteria engaged in interstitial motility.

Non-Maxwellian fast particle effects in gyrokinetic GENE simulations

NASA Astrophysics Data System (ADS)

Di Siena, A.; Görler, T.; Doerk, H.; Bilato, R.; Citrin, J.; Johnson, T.; Schneider, M.; Poli, E.; JET Contributors

2018-04-01

Fast ions have recently been found to significantly impact and partially suppress plasma turbulence both in experimental and numerical studies in a number of scenarios. Understanding the underlying physics and identifying the range of their beneficial effect is an essential task for future fusion reactors, where highly energetic ions are generated through fusion reactions and external heating schemes. However, in many of the gyrokinetic codes fast ions are, for simplicity, treated as equivalent-Maxwellian-distributed particle species, although it is well known that to rigorously model highly non-thermalised particles, a non-Maxwellian background distribution function is needed. To study the impact of this assumption, the gyrokinetic code GENE has recently been extended to support arbitrary background distribution functions which might be either analytical, e.g., slowing down and bi-Maxwellian, or obtained from numerical fast ion models. A particular JET plasma with strong fast-ion related turbulence suppression is revised with these new code capabilities both with linear and nonlinear gyrokinetic simulations. It appears that the fast ion stabilization tends to be less strong but still substantial with more realistic distributions, and this improves the quantitative power balance agreement with experiments.

Magnetic resonance imaging of granular materials

NASA Astrophysics Data System (ADS)

Stannarius, Ralf

2017-05-01

Magnetic Resonance Imaging (MRI) has become one of the most important tools to screen humans in medicine; virtually every modern hospital is equipped with a Nuclear Magnetic Resonance (NMR) tomograph. The potential of NMR in 3D imaging tasks is by far greater, but there is only "a handful" of MRI studies of particulate matter. The method is expensive, time-consuming, and requires a deep understanding of pulse sequences, signal acquisition, and processing. We give a short introduction into the physical principles of this imaging technique, describe its advantages and limitations for the screening of granular matter, and present a number of examples of different application purposes, from the exploration of granular packing, via the detection of flow and particle diffusion, to real dynamic measurements. Probably, X-ray computed tomography is preferable in most applications, but fast imaging of single slices with modern MRI techniques is unmatched, and the additional opportunity to retrieve spatially resolved flow and diffusion profiles without particle tracking is a unique feature.

Participation in High Energy Physics at the University of Chicago

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinec, Emil J.

2013-06-27

This report covers research at the University of Chicago in theoretical high energy physics and its connections to cosmology, over the period Nov. 1, 2009 to April 30, 2013. This research is divided broadly into two tasks: Task A, which covers a broad array of topics in high energy physics; and task C, primarily concerned with cosmology.

Tunable particles alter macrophage uptake based on combinatorial effects of physical properties

PubMed Central

Garapaty, Anusha

2017-01-01

Abstract The ability to tune phagocytosis of particle‐based therapeutics by macrophages can enhance their delivery to macrophages or reduce their phagocytic susceptibility for delivery to non‐phagocytic cells. Since phagocytosis is affected by the physical and chemical properties of particles, it is crucial to identify any interplay between physical properties of particles in altering phagocytic interactions. The combinatorial effect of physical properties size, shape and stiffness was investigated on Fc receptor mediated macrophage interactions by fabrication of layer‐by‐layer tunable particles of constant surface chemistry. Our results highlight how changing particle stiffness affects phagocytic interaction intricately when combined with varying size or shape. Increase in size plays a dominant role over reduction in stiffness in reducing internalization by macrophages for spherical particles. Internalization of rod‐shaped, but not spherical particles, was highly dependent on stiffness. These particles demonstrate the interplay between size, shape and stiffness in interactions of Fc‐functionalized particles with macrophages during phagocytosis. PMID:29313025

Benefits of interhemispheric integration on the Japanese Kana script-matching tasks.

PubMed

Yoshizaki, K; Tsuji, Y

2000-02-01

We tested Banich's hypothesis that the benefits of bihemispheric processing were enhanced as task complexity increased, when some procedural shortcomings in the previous studies were overcome by using Japanese Kana script-matching tasks. In Exp. 1, the 20 right-handed subjects were given the Physical-Identity task (Katakana-Katakana scripts matching) and the Name-Identity task (Katakana-Hiragana scripts matching). On both tasks, a pair of Kana scripts was tachistoscopically presented in the left, right, and bilateral visual fields. Distractor stimuli were also presented with target Kana scripts on both tasks to equate the processing load between the hemispheres. Analysis showed that, while a bilateral visual-field advantage was found on the name-identity task, a unilateral visual-field advantage was found on the physical-identity task, suggesting that, as the computational complexity of the encoding stage was enhanced, the benefits of bilateral hemispheric processing increased. In Exp. 2, the 16 right-handed subjects were given the same physical-identity task as in Exp. 1, except Hiragana scripts were used as distractors instead of digits to enhance task difficulty. Analysis showed no differences in performance between the unilateral and bilateral visual fields. Taking into account these results of physical-identity tasks for both Exps. 1 and 2, enhancing task demand in the stage of ignoring distractors made the unilateral visual-field advantage obtained in Exp. 1 disappear in Exp. 2. These results supported Banich's hypothesis.

Task value profiles across subjects and aspirations to physical and IT-related sciences in the United States and Finland.

PubMed

Chow, Angela; Eccles, Jacquelynne S; Salmela-Aro, Katariina

2012-11-01

Two independent studies were conducted to extend previous research by examining the associations between task value priority patterns across school subjects and aspirations toward the physical and information technology- (IT-) related sciences. Study 1 measured task values of a sample of 10th graders in the United States (N = 249) across (a) physics and chemistry, (b) math, and (c) English. Study 2 measured task values of a sample of students in the second year of high school in Finland (N = 351) across (a) math and science, (b) Finnish, and (c) the arts and physical education. In both studies, students were classified into groups according to how they ranked math and science in relation to the other subjects. Regression analyses indicated that task value group membership significantly predicted subsequent aspirations toward physical and IT-related sciences measured 1-2 years later. The task value groups who placed the highest priority on math and science were significantly more likely to aspire to physical and IT-related sciences than were the other groups. These findings provide support for the theoretical assumption regarding the predictive role of intraindividual hierarchical patterns of task values for subsequent preferences and choices suggested by the Eccles [Parsons] (1983) expectancy-value model.

WE-FG-BRB-01: Clinical Significance of RBE Variations in Proton Therapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paganetti, H.

2016-06-15

The physical pattern of energy deposition and the enhanced relative biological effectiveness (RBE) of protons and carbon ions compared to photons offer unique and not fully understood or exploited opportunities to improve the efficacy of radiation therapy. Variations in RBE within a pristine or spread out Bragg peak and between particle types may be exploited to enhance cell killing in target regions without a corresponding increase in damage to normal tissue structures. In addition, the decreased sensitivity of hypoxic tumors to photon-based therapies may be partially overcome through the use of more densely ionizing radiations. These and other differences betweenmore » particle and photon beams may be used to generate biologically optimized treatments that reduce normal tissue complications. In this symposium, speakers will examine the impact of the RBE of charged particles on measurable biological endpoints, treatment plan optimization, and the prediction or retrospective assessment of treatment outcomes. In particular, an AAPM task group was formed to critically examine the evidence for a spatially-variant RBE in proton therapy. Current knowledge of proton RBE variation with respect to dose, biological endpoint, and physics parameters will be reviewed. Further, the clinical relevance of these variations will be discussed. Recent work focused on improving simulations of radiation physics and biological response in proton and carbon ion therapy will also be presented. Finally, relevant biology research and areas of research needs will be highlighted, including the dependence of RBE on genetic factors including status of DNA repair pathways, the sensitivity of cancer stem-like cells to charged particles, the role of charged particles in hypoxic tumors, and the importance of fractionation effects. In addition to the physical advantages of protons and more massive ions over photons, the future application of biologically optimized treatment plans and their potential to provide higher levels of local tumor control and improved normal tissue sparing will be discussed. Learning Objectives: To assess whether the current practice of a constant RBE of 1.1 should be revised or maintained in proton therapy and to evaluate the potential clinical consequences of delivering RBE-weighted dose distributions based on variable RBE To review current research on biological models used to predict the increased biological effectiveness of proton and carbon ions to help move towards a practical understanding and implementation of biological optimization in particle therapy To discuss potential differences in biological mechanisms between photons and charged particles (light and heavy ions) that could impact clinical cancer therapy H. Paganetti, NCI U19 CA21239D. Grosshans, Our research is supported by the NCIK. Held, Funding Support: National Cancer Institute of the National Institutes of Health, USA, under Award Number R21CA182259 and Federal Share of Program Income Earned by Massachusetts General Hospital on C06CA059267, Proton Therapy Research and Treatment Center.« less

Development of Physical Employment Standards for the Royal Australian Navy: Validation of Identified Whole-of-ship Tasks

DTIC Science & Technology

2014-11-01

to determining individual CS tasks, this partially satisfied Navy’s request to quantify the physical demands of the course in order to draw parity ...will enable comparison between task demands on the course and during on-board duties. These data will be used to determine whether there is parity ...between the physical and physiological demands of the ACSC (or components of it) and CS tasks performed on-board each platform. If parity is drawn

Same-sign WW scattering at the LHC: can we discover BSM effects before discovering new states?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kalinowski, Jan; Kozów, Paweł; Pokorski, Stefan

It is possible that measurements of vector boson scattering (VBS) at the LHC will reveal disagreement with Standard Model predictions, but no new particles will be observed directly. The task is then to learn as much as possible about the new physics from a VBS analysis carried within the framework of the Effective Field Theory (EFT). In this paper we discuss issues related to the correct usage of the EFT when the WW invariant mass is not directly accessible experimentally, as in purely leptonic W decay channels. The strategies for future data analyses in case such scenario indeed occurs aremore » proposed.« less

VoxelMages: a general-purpose graphical interface for designing geometries and processing DICOM images for PENELOPE.

PubMed

Giménez-Alventosa, V; Ballester, F; Vijande, J

2016-12-01

The design and construction of geometries for Monte Carlo calculations is an error-prone, time-consuming, and complex step in simulations describing particle interactions and transport in the field of medical physics. The software VoxelMages has been developed to help the user in this task. It allows to design complex geometries and to process DICOM image files for simulations with the general-purpose Monte Carlo code PENELOPE in an easy and straightforward way. VoxelMages also allows to import DICOM-RT structure contour information as delivered by a treatment planning system. Its main characteristics, usage and performance benchmarking are described in detail. Copyright © 2016 Elsevier Ltd. All rights reserved.

The role of probabilistic formulations of sediment transport aimed at describing the behavior of soil-mantled hillslopes over geomorphic timescales (Invited)

NASA Astrophysics Data System (ADS)

Furbish, D. J.; Roering, J. J.

2013-12-01

Recent discussions of local versus nonlocal sediment transport on hillslopes offer a lens for considering uncertainty in formulations of transport rates that are aimed at characterizing patchy, intermittent sediment motions in steeplands. Here we describe a general formulation for transport that is based on a convolution integral of the factors controlling the entrainment and disentrainment of sediment particles on a hillslope. In essence, such a formulation represents a ';flux' version of the Master equation, a general probabilistic (kinematic) formulation of mass conservation. As such, with the relevant physics invoked to represent entrainment and disentrainment, a nonlocal formulation quite happily accommodates local transport (and looks/behaves like a local formulation), as well as nonlocal transport, depending on the characteristic length scale of particle motions relative to the length scale at which the factors controlling particle transport are defined or measured. Nonetheless, nonlocal formulations of the sediment flux have mostly (but not entirely) outpaced experimental and field-based observations needed to inform the theory. At risk is bringing to bear a sophisticated mathematics that is not supported by our uncertain understanding of the processes involved. Experimental and field-based measurements of entrainment rates and particle travel distances are difficult to obtain, notably given the intermittency of many hillslope transport processes and the slow rates of change in hillslope morphology. A ';test' of a specific nonlocal formulation applied to hillslope evolution must therefore in part rest on consistency between measured hillslope configurations and predicted (i.e., modeled) hillslope configurations predicated on the proposed nonlocal formulation, assuming sufficient knowledge of initial and boundary conditions. On the other hand, because of its probabilistic basis, the formulation is in principle well suited to the task of describing transport relevant to geomorphic timescales -- in view of the stochastic nature of the transport processes occurring over these timescales and the uncertainty of our understanding of the physics involved. Moreover, in its basic form, the nonlocal formulation of the sediment flux is such that appropriate physics can be readily embedded within it as we learn more. And, the formulation is space-time averaged in a way that accommodates discontinuous (patchy, intermittent) sediment motions.

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs.

PubMed

Müller, Corsin A; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

2016-01-01

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject's level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance.

Inhibitory Control, but Not Prolonged Object-Related Experience Appears to Affect Physical Problem-Solving Performance of Pet Dogs

PubMed Central

Müller, Corsin A.; Riemer, Stefanie; Virányi, Zsófia; Huber, Ludwig; Range, Friederike

2016-01-01

Human infants develop an understanding of their physical environment through playful interactions with objects. Similar processes may influence also the performance of non-human animals in physical problem-solving tasks, but to date there is little empirical data to evaluate this hypothesis. In addition or alternatively to prior experiences, inhibitory control has been suggested as a factor underlying the considerable individual differences in performance reported for many species. Here we report a study in which we manipulated the extent of object-related experience for a cohort of dogs (Canis familiaris) of the breed Border Collie over a period of 18 months, and assessed their level of inhibitory control, prior to testing them in a series of four physical problem-solving tasks. We found no evidence that differences in object-related experience explain variability in performance in these tasks. It thus appears that dogs do not transfer knowledge about physical rules from one physical problem-solving task to another, but rather approach each task as a novel problem. Our results, however, suggest that individual performance in these tasks is influenced in a complex way by the subject’s level of inhibitory control. Depending on the task, inhibitory control had a positive or a negative effect on performance and different aspects of inhibitory control turned out to be the best predictors of individual performance in the different tasks. Therefore, studying the interplay between inhibitory control and problem-solving performance will make an important contribution to our understanding of individual and species differences in physical problem-solving performance. PMID:26863141

Teaching Elementary Particle Physics: Part I

ERIC Educational Resources Information Center

Hobson, Art

2011-01-01

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

The Ultimate Structure of Matter: The High Energy Physics Program from the 1950s through the 1980s

DOE R&D Accomplishments Database

1990-02-01

This discusses the following topics in High Energy Physics: The Particle Zoo; The Strong and the Weak; The Particle Explosion; Deep Inside the Nucleon; The Search for Unity; Physics in Collision; The Standard Model; Particles and the Cosmos; and Practical Benefits.

Computer Simulations for Lab Experiences in Secondary Physics

ERIC Educational Resources Information Center

Murphy, David Shannon

2012-01-01

Physical science instruction often involves modeling natural systems, such as electricity that possess particles which are invisible to the unaided eye. The effect of these particles' motion is observable, but the particles are not directly observable to humans. Simulations have been developed in physics, chemistry and biology that, under certain…

[Meta-analyses of quarks, baryons and mesons--a "Cochrane Collaboration" in particle physics].

PubMed

Sauerland, Stefan; Sauerland, Thankmar; Antes, Gerd; Barnett, R Michael

2002-02-01

Within the last 20 years meta-analysis has become an important research technique in medicine for integrating the results of independent studies. Meta-analytical techniques, however, are much older. In particle physics for 50 years now the properties of huge numbers of particles have been assessed in meta-analyses. The Cochrane Collaboration's counterpart in physics is the Particle Data Group. This article compares methodological and organisational aspects of meta-analyses in medicine and physics. Several interesting parallels exist, especially with regard to methodology.

ALICE Masterclass on strangeness

NASA Astrophysics Data System (ADS)

Foka, Panagiota; Janik, Małgorzata

2014-04-01

An educational activity, the International Particle Physics Masterclasses, was developed by the International Particle Physics Outreach Group with the aim to bring the excitement of cutting-edge particle-physics research into the classroom. Thousands of pupils, every year since 2005, in many countries all over the world, are hosted in research centers or universities close to their schools and become "scientists for a day" as they are introduced to the mysteries of particle physics. The program of a typical day includes lectures that give insight to topics and methods of fundamental research followed by a "hands-on" session where the high-school students perform themselves measurements on real data from particle-physics experiments. The last three years data from the ALICE experiment at LHC were used. The performed measurement "strangeness enhancement" and the employed methodology are presented.

The effects of fatigue on performance in simulated nursing work.

PubMed

Barker, Linsey M; Nussbaum, Maury A

2011-09-01

Fatigue is associated with increased rates of medical errors and healthcare worker injuries, yet existing research in this sector has not considered multiple dimensions of fatigue simultaneously. This study evaluated hypothesised causal relationships between mental and physical fatigue and performance. High and low levels of mental and physical fatigue were induced in 16 participants during simulated nursing work tasks in a laboratory setting. Task-induced changes in fatigue dimensions were quantified using both subjective and objective measures, as were changes in performance on physical and mental tasks. Completing the simulated work tasks increased total fatigue, mental fatigue and physical fatigue in all experimental conditions. Higher physical fatigue adversely affected measures of physical and mental performance, whereas higher mental fatigue had a positive effect on one measure of mental performance. Overall, these results suggest causal effects between manipulated levels of mental and physical fatigue and task-induced changes in mental and physical performance. STATEMENT OF RELEVANCE: Nurse fatigue and performance has implications for patient and provider safety. Results from this study demonstrate the importance of a multidimensional view of fatigue in understanding the causal relationships between fatigue and performance. The findings can guide future work aimed at predicting fatigue-related performance decrements and designing interventions.

Entrained-flow gasification at elevated pressure: Volume 1: Final technical report, March 1, 1985-April 30,1987

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hedman, P.O.; Smoot, L.D.; Smith, P.J.

1987-10-15

The general purpose of this research program was to develop a basic understanding of the physical and chemical processes in entrained coal gasification and to use the results to improve and evaluate an entrained gasification computer model. The first task included the collection and analysis of in-situ gasifier data at elevated pressures with three coal types (North Dakota lignite, Wyoming subbituminous and Illinois bituminous), the design, construction, and testing of new coal/oxygen/steam injectors with a fourth coal type (Utah bituminous), the collection of supporting turbulent fluid dynamic (LDV) data from cold-flow studies, and the investigation of the feasibility of usingmore » laser-based (CARS) daignostic instruments to make measurements in coal flames. The second task included improvements to the two-dimensional gasifier submodels, tabulation and evaluation of new coal devolatilization and char oxidation data for predictions, fundamental studies of turbulent particle dispersion, the development of improved numerical methods, and validation of the comprehensive model through comparison of predictions with experimental results. The third task was to transfer technical advances to industry and to METC through technical seminars, production of a detailed data book, code placement, and publication of results. Research results for these three tasks are summarized briefly here and presented in detail in the body of the report and in supporting references. 202 refs., 73 figs., 23 tabs.« less

A systematic random sampling scheme optimized to detect the proportion of rare synapses in the neuropil.

PubMed

da Costa, Nuno Maçarico; Hepp, Klaus; Martin, Kevan A C

2009-05-30

Synapses can only be morphologically identified by electron microscopy and this is often a very labor-intensive and time-consuming task. When quantitative estimates are required for pathways that contribute a small proportion of synapses to the neuropil, the problems of accurate sampling are particularly severe and the total time required may become prohibitive. Here we present a sampling method devised to count the percentage of rarely occurring synapses in the neuropil using a large sample (approximately 1000 sampling sites), with the strong constraint of doing it in reasonable time. The strategy, which uses the unbiased physical disector technique, resembles that used in particle physics to detect rare events. We validated our method in the primary visual cortex of the cat, where we used biotinylated dextran amine to label thalamic afferents and measured the density of their synapses using the physical disector method. Our results show that we could obtain accurate counts of the labeled synapses, even when they represented only 0.2% of all the synapses in the neuropil.

Big Data in HEP: A comprehensive use case study

NASA Astrophysics Data System (ADS)

Gutsche, Oliver; Cremonesi, Matteo; Elmer, Peter; Jayatilaka, Bo; Kowalkowski, Jim; Pivarski, Jim; Sehrish, Saba; Mantilla Surez, Cristina; Svyatkovskiy, Alexey; Tran, Nhan

2017-10-01

Experimental Particle Physics has been at the forefront of analyzing the worlds largest datasets for decades. The HEP community was the first to develop suitable software and computing tools for this task. In recent times, new toolkits and systems collectively called Big Data technologies have emerged to support the analysis of Petabyte and Exabyte datasets in industry. While the principles of data analysis in HEP have not changed (filtering and transforming experiment-specific data formats), these new technologies use different approaches and promise a fresh look at analysis of very large datasets and could potentially reduce the time-to-physics with increased interactivity. In this talk, we present an active LHC Run 2 analysis, searching for dark matter with the CMS detector, as a testbed for Big Data technologies. We directly compare the traditional NTuple-based analysis with an equivalent analysis using Apache Spark on the Hadoop ecosystem and beyond. In both cases, we start the analysis with the official experiment data formats and produce publication physics plots. We will discuss advantages and disadvantages of each approach and give an outlook on further studies needed.

Do visually salient stimuli reduce children's risky decisions?

PubMed

Schwebel, David C; Lucas, Elizabeth K; Pearson, Alana

2009-09-01

Children tend to overestimate their physical abilities, and that tendency is related to risk for unintentional injury. This study tested whether or not children estimate their physical ability differently when exposed to stimuli that were highly visually salient due to fluorescent coloring. Sixty-nine 6-year-olds judged physical ability to complete laboratory-based physical tasks. Half judged ability using tasks that were painted black; the other half judged the same tasks, but the stimuli were striped black and fluorescent lime-green. Results suggest the two groups judged similarly, but children took longer to judge perceptually ambiguous tasks when those tasks were visually salient. In other words, visual salience increased decision-making time but not accuracy of judgment. These findings held true after controlling for demographic and temperament characteristics.

Dissociating intuitive physics from intuitive psychology: Evidence from Williams syndrome.

PubMed

Kamps, Frederik S; Julian, Joshua B; Battaglia, Peter; Landau, Barbara; Kanwisher, Nancy; Dilks, Daniel D

2017-11-01

Prior work suggests that our understanding of how things work ("intuitive physics") and how people work ("intuitive psychology") are distinct domains of human cognition. Here we directly test the dissociability of these two domains by investigating knowledge of intuitive physics and intuitive psychology in adults with Williams syndrome (WS) - a genetic developmental disorder characterized by severely impaired spatial cognition, but relatively spared social cognition. WS adults and mental-age matched (MA) controls completed an intuitive physics task and an intuitive psychology task. If intuitive physics is a distinct domain (from intuitive psychology), then we should observe differential impairment on the physics task for individuals with WS compared to MA controls. Indeed, adults with WS performed significantly worse on the intuitive physics than the intuitive psychology task, relative to controls. These results support the hypothesis that knowledge of the physical world can be disrupted independently from knowledge of the social world. Copyright © 2017 Elsevier B.V. All rights reserved.

Three-Dimensional Visualization of Particle Tracks.

ERIC Educational Resources Information Center

Julian, Glenn M.

1993-01-01

Suggests ways to bring home to the introductory physics student some of the excitement of recent discoveries in particle physics. Describes particle detectors and encourages the use of the Standard Model along with real images of particle tracks to determine three-dimensional views of tracks. (MVL)

Plato's TIMAIOσ (TIMAEUS) and Modern Particle Physics

NASA Astrophysics Data System (ADS)

Machleidt, Ruprecht

2005-04-01

It is generally known that the question, ``What are the smallest particles (elementary particles) that all matter is made from?'', was posed already in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. It will be the purpose of my contribution to point out that this perception is wrong. Modern particle physics is not just a primitive atomism. More important than the materialistic particles are the underlying symmetries (e. g., SU(3) and SU(6)). A similar idea was first advanced by Plato in his dialog TIMAIOσ (Latin translation: TIMAEUS): Geometric symmetries generate the materialistic particles from a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle physics. This fact, which is unfortunately little known, has been pointed out repeatedly by Heisenberg (see, e. g., Werner Heisenberg, Across the Frontiers, Harper & Row, New York, 1974).

Breaking a habit: a further role of the phonological loop in action control.

PubMed

Saeki, Erina; Baddeley, Alan D; Hitch, Graham J; Saito, Satoru

2013-10-01

Recent research has suggested that keeping track of a task goal in rapid task switching may depend on the phonological loop component of working memory. In this study, we investigated whether the phonological loop plays a similar role when a single switch extending over several trials is required after many trials on which one has performed a competing task. Participants were shown pairs of digits varying in numerical and physical size, and they were required to decide which digit was numerically or physically larger. An experimental cycle consisted of four blocks of 24 trials. In Experiment 1, participants in the task change groups performed the numerical-size judgment task during the first three blocks, and then changed to the physical-size judgment task in the fourth. Participants in the continuation groups performed only the physical-size judgment task throughout all four blocks. We found negative effects of articulatory suppression on the fourth block, but only in the task change groups. Experiment 2 was a replication, with the modification that both groups received identical instructions and practice. Experiment 3 was a further replication using numerical-size judgment as the target task. The results showed a pattern similar to that from Experiment 1, with negative effects of articulatory suppression found only in the task change group. The congruity of numerical and physical size had a reliable effect on performance in all three experiments, but unlike the task change, it did not reliably interact with articulatory suppression. The results suggest that in addition to its well-established role in rapid task switching, the phonological loop also contributes to active goal maintenance in longer-term action control.

Fermilab | Mu2e

Science.gov Websites

Interactions.org Particle Physics News Image Bank Fermilab in the News Quantum Diaries Mu2e: muon-to-electron works The Mu2e detector is a particle physics detector embedded in a series of superconducting magnets advance research at the Intensity Frontier. The U.S. Particle Physics Project Prioritization Panel, P5

History of Particle Physics

Science.gov Websites

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

Quarked!--Adventures in Particle Physics Education

ERIC Educational Resources Information Center

MacDonald, Teresa; Bean, Alice

2009-01-01

Particle physics is a subject that can send shivers down the spines of students and educators alike--with visions of long mathematical equations and inscrutable ideas. This perception, along with a full curriculum, often leaves this topic the road less traveled until the latter years of school. Particle physics, including quarks, is typically not…

Let's Have a Coffee with the Standard Model of Particle Physics!

ERIC Educational Resources Information Center

Woithe, Julia; Wiener, Gerfried J.; Van der Veken, Frederik F.

2017-01-01

The Standard Model of particle physics is one of the most successful theories in physics and describes the fundamental interactions between elementary particles. It is encoded in a compact description, the so-called "Lagrangian," which even fits on t-shirts and coffee mugs. This mathematical formulation, however, is complex and only…

On some physical and dynamical properties of microplastic particles in marine environment.

PubMed

Chubarenko, I; Bagaev, A; Zobkov, M; Esiukova, E

2016-07-15

Simplified physical models and geometrical considerations reveal general physical and dynamical properties of microplastic particles (0.5-5mm) of different density, shape and size in marine environment. Windage of extremely light foamed particles, surface area and fouling rate of slightly positively buoyant microplastic spheres, films and fibres and settling velocities of negatively buoyant particles are analysed. For the Baltic Sea dimensions and under the considered idealised external conditions, (i) only one day is required for a foamed polystyrene particle to cross the sea (ca. 250km); (ii) polyethylene fibres should spend about 6-8months in the euphotic zone before sinking due to bio-fouling, whilst spherical particles can be retained on the surface up to 10-15years; (iii) for heavy microplastic particles, the time of settling through the water column in the central Gotland basin (ca. 250m) is less than 18h. Proper physical setting of the problem of microplastics transport and developing of physically-based parameterisations are seen as applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

Engineering and Physics Optimization of Breed and Burn Fast Reactor Systems; NUCLEAR ENERGY RESEARCH INITIATIVE (NERI) QUARTERLY PROGRESS REPORT

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pavel Hejzlar, Peter Yarsky, Mike Driscoll, Dan Wachs, Kevan Weaver, Ken Czerwinski, Mike Pope, James Parry, Theron D. Marshall, Cliff B. Davis, Dustin Crawford, Thomas Hartmann, Pradip Saha; Hejzlar, Pavel; Yarsky, Peter

2005-01-31

This project is organized under four major tasks (each of which has two or more subtasks) with contributions among the three collaborating organizations (MIT, INEEL and ANL-West): Task A: Core Physics and Fuel Cycle; Task B: Core Thermal Hydraulics; Task C: Plant Design; Task D: Fuel Design The lead PI, Michael J. Driscoll, has consolidated and summarized the technical progress submissions provided by the contributing investigators from all sites, under the above principal task headings.

Lipoproteins: When size really matters

PubMed Central

German, J. Bruce; Smilowitz, Jennifer T.; Zivkovic, Angela M.

2010-01-01

The field of nanoscience is extending the applications of physics, chemistry and biology into previously unapproached infinitesimal length scales. Understanding the behavior and manipulating the positions and properties of single atoms and molecules hold great potential to improve areas of science as disparate as medicine and computation, and communication and orbiting satellites. Yet, in the race to develop novel, previously unavailable nanoparticles, there is an opportunity for scientists in this field to digress and to apply their growing understanding of nanoscience and the tools of nanotechnology to one of the most pressing problems in all of human biology—diseases related to lipoproteins. Although not appreciated outside the field of lipoprotein biology, variations in the compositions, structures and properties of these nanoscale-sized, blood-borne particles are responsible for most of the variations in health, morbidity and mortality in the Western world. If the lipoproteins could be understood at the nanometer length scale with precise details of their structures and functions, scientists could understand a wide range of perplexing physiological processes and also address the dysfunctions in normal lipoprotein biology that lead to such diseases as hypercholesterolemia, heart disease, stroke and neurodegenerative diseases. Furthermore, if the capabilities of nanoscience to assemble and manipulate nanometer-sized particles could be recruited to studies of lipoproteins, these biological particles would provide a new dimension to therapeutic agents, and these natural particles could be designed to carry out many specialized beneficial tasks. PMID:20592953

U.S. Army physical demands study: Identification and validation of the physically demanding tasks of combat arms occupations.

PubMed

Sharp, Marilyn A; Cohen, Bruce S; Boye, Michael W; Foulis, Stephen A; Redmond, Jan E; Larcom, Kathleen; Hydren, Jay R; Gebhardt, Deborah L; Canino, Maria C; Warr, Bradley J; Zambraski, Edward J

2017-11-01

In 2013, the U.S. Army began developing physical tests to predict a recruit's ability to perform the critical, physically demanding tasks (CPDTs) of combat arms jobs previously not open to women. The purpose of this paper is to describe the methodology and results of analyses of the accuracy and inclusiveness of the critical physically demanding task list. While the job analysis included seven combat arms jobs, only data from the 19D Cavalry Scout occupation are presented as the process was similar for all seven jobs. Job analysis METHODS: As the foundation, senior subject matter experts from each job reviewed materials and reached consensus on the CPDTs and performance standards for each job. The list was reviewed by Army leadership and provided to the researchers. The job analysis consisted of reviewing job and task related documents and field manuals, observing >900 soldiers performing the 32 CPDTs, conducting two focus groups for each job, and analyzing responses to widely distributed job analysis questionnaires. Of the 32 CPDTs identified for seven combat jobs, nine were relevant to 19D soldiers. Focus group discussions and job analysis questionnaire results supported the tasks and standards identified by subject matter experts while also identifying additional tasks. The tasks identified by subject matter experts were representative of the physically demanding aspects of the 19D occupation. Published by Elsevier Ltd.

Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial

PubMed Central

Falbo, S.; Condello, G.; Capranica, L.; Forte, R.

2016-01-01

Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training (n = 16) and physical-cognitive dual task (DT) training (n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living. PMID:28053985

Effects of Physical-Cognitive Dual Task Training on Executive Function and Gait Performance in Older Adults: A Randomized Controlled Trial.

PubMed

Falbo, S; Condello, G; Capranica, L; Forte, R; Pesce, C

2016-01-01

Physical and cognitive training seem to counteract age-related decline in physical and mental function. Recently, the possibility of integrating cognitive demands into physical training has attracted attention. The purpose of this study was to evaluate the effects of twelve weeks of designed physical-cognitive training on executive cognitive function and gait performance in older adults. Thirty-six healthy, active individuals aged 72.30 ± 5.84 years were assigned to two types of physical training with major focus on physical single task (ST) training ( n = 16) and physical-cognitive dual task (DT) training ( n = 20), respectively. They were tested before and after the intervention for executive function (inhibition, working memory) through Random Number Generation and for gait (walking with/without negotiating hurdles) under both single and dual task (ST, DT) conditions. Gait performance improved in both groups, while inhibitory performance decreased after exercise training with ST focus but tended to increase after training with physical-cognitive DT focus. Changes in inhibition performance were correlated with changes in DT walking performance with group differences as a function of motor task complexity (with/without hurdling). The study supports the effectiveness of group exercise classes for older individuals to improve gait performance, with physical-cognitive DT training selectively counteracting the age-related decline in a core executive function essential for daily living.

Electrophysiological evidence of automatic early semantic processing.

PubMed

Hinojosa, José A; Martín-Loeches, Manuel; Muñoz, Francisco; Casado, Pilar; Pozo, Miguel A

2004-01-01

This study investigates the automatic-controlled nature of early semantic processing by means of the Recognition Potential (RP), an event-related potential response that reflects lexical selection processes. For this purpose tasks differing in their processing requirements were used. Half of the participants performed a physical task involving a lower-upper case discrimination judgement (shallow processing requirements), whereas the other half carried out a semantic task, consisting in detecting animal names (deep processing requirements). Stimuli were identical in the two tasks. Reaction time measures revealed that the physical task was easier to perform than the semantic task. However, RP effects elicited by the physical and semantic tasks did not differ in either latency, amplitude, or topographic distribution. Thus, the results from the present study suggest that early semantic processing is automatically triggered whenever a linguistic stimulus enters the language processor.

U.S. Army Physical Demands Study: Reliability of Simulations of Physically Demanding Tasks Performed by Combat Arms Soldiers.

PubMed

Foulis, Stephen A; Redmond, Jan E; Frykman, Peter N; Warr, Bradley J; Zambraski, Edward J; Sharp, Marilyn A

2017-12-01

Foulis, SA, Redmond, JE, Frykman, PN, Warr, BJ, Zambraski, EJ, and Sharp, MA. U.S. Army physical demands study: reliability of simulations of physically demanding tasks performed by combat arms soldiers. J Strength Cond Res 31(12): 3245-3252, 2017-Recently, the U.S. Army has mandated that soldiers must successfully complete the physically demanding tasks of their job to graduate from their Initial Military Training. Evaluating individual soldiers in the field is difficult; however, simulations of these tasks may aid in the assessment of soldiers' abilities. The purpose of this study was to determine the reliability of simulated physical soldiering tasks relevant to combat arms soldiers. Three cohorts of ∼50 soldiers repeated a subset of 8 simulated tasks 4 times over 2 weeks. Simulations included: sandbag carry, casualty drag, and casualty evacuation from a vehicle turret, move under direct fire, stow ammunition on a tank, load the main gun of a tank, transferring ammunition with a field artillery supply vehicle, and a 4-mile foot march. Reliability was assessed using intraclass correlation coefficients (ICCs), standard errors of measurement (SEMs), and 95% limits of agreement. Performance of the casualty drag and foot march did not improve across trials (p > 0.05), whereas improvements, suggestive of learning effects, were observed on the remaining 6 tasks (p ≤ 0.05). The ICCs ranged from 0.76 to 0.96, and the SEMs ranged from 3 to 16% of the mean. These 8 simulated tasks show high reliability. Given proper practice, they are suitable for evaluating the ability of Combat Arms Soldiers to complete the physical requirements of their jobs.

Irrelevant reward and selection histories have different influences on task-relevant attentional selection.

PubMed

MacLean, Mary H; Giesbrecht, Barry

2015-07-01

Task-relevant and physically salient features influence visual selective attention. In the present study, we investigated the influence of task-irrelevant and physically nonsalient reward-associated features on visual selective attention. Two hypotheses were tested: One predicts that the effects of target-defining task-relevant and task-irrelevant features interact to modulate visual selection; the other predicts that visual selection is determined by the independent combination of relevant and irrelevant feature effects. These alternatives were tested using a visual search task that contained multiple targets, placing a high demand on the need for selectivity, and that was data-limited and required unspeeded responses, emphasizing early perceptual selection processes. One week prior to the visual search task, participants completed a training task in which they learned to associate particular colors with a specific reward value. In the search task, the reward-associated colors were presented surrounding targets and distractors, but were neither physically salient nor task-relevant. In two experiments, the irrelevant reward-associated features influenced performance, but only when they were presented in a task-relevant location. The costs induced by the irrelevant reward-associated features were greater when they oriented attention to a target than to a distractor. In a third experiment, we examined the effects of selection history in the absence of reward history and found that the interaction between task relevance and selection history differed, relative to when the features had previously been associated with reward. The results indicate that under conditions that demand highly efficient perceptual selection, physically nonsalient task-irrelevant and task-relevant factors interact to influence visual selective attention.

Physical Principles of the Method for Determination of Geometrical Characteristics and Particle Recognition in Digital Holography

NASA Astrophysics Data System (ADS)

Dyomin, V. V.; Polovtsev, I. G.; Davydova, A. Yu.

2018-03-01

The physical principles of a method for determination of geometrical characteristics of particles and particle recognition based on the concepts of digital holography, followed by processing of the particle images reconstructed from the digital hologram, using the morphological parameter are reported. An example of application of this method for fast plankton particle recognition is given.

A matrix for the qualitative evaluation of nursing tasks.

PubMed

Durosaiye, Isaiah O; Hadjri, Karim; Liyanage, Champika L; Bennett, Kina

2018-04-01

To formulate a model for patient-nurse interaction; to compile a comprehensive list of nursing tasks on hospital wards; and to construct a nursing tasks demand matrix. The physical demands associated with nursing profession are of growing interest among researchers. Yet, it is the complexity of nursing tasks that defines the demands of ward nurses' role. This study explores nursing tasks, based on patient-nurse interaction on hospital wards. Extant literature was reviewed to formulate a patient-nurse interaction model. Twenty ward nurses were interviewed to compile a list of nursing tasks. These nursing tasks were mapped against the patient-nurse interaction model. A patient-nurse interaction model was created, consisting of: (1) patient care, (2) patient surveillance and (3) patient support. Twenty-three nursing tasks were identified. The nursing tasks demand matrix was constructed. Ward managers may use a nursing tasks demand matrix to determine the demands of nursing tasks on ward nurses. While many studies have explored either the physical or the psychosocial aspects of nursing tasks separately, this study suggests that the physicality of nursing tasks must be evaluated in tandem with their complexity. Ward managers may take a holistic approach to nursing tasks evaluation by using a nursing tasks demand matrix. © 2017 John Wiley & Sons Ltd.

Task Analysis for Health Occupations. Cluster: Rehabilitation Services. Occupation: Physical Therapist Assistant. Education for Employment Task Lists.

ERIC Educational Resources Information Center

Lathrop, Janice

Task analyses are provided for two duty areas for the occupation of physical therapist assistant in the rehabilitation services cluster. Ten tasks are listed for the duty area "providing therapeutic measures": apply cold compress, administer hot soak, apply heat lamp, apply warm compress, apply ice bag, assist with dressing change, apply…

The power of competition: Effects of social motivation on attention, sustained physical effort, and learning.

PubMed

DiMenichi, Brynne C; Tricomi, Elizabeth

2015-01-01

Competition has often been implicated as a means to improve effort-based learning and attention. Two experiments examined the effects of competition on effort and memory. In Experiment 1, participants completed a physical effort task in which they were rewarded for winning an overall percentage, or for winning a competition they believed was against another player. In Experiment 2, participants completed a memory task in which they were rewarded for remembering an overall percentage of shapes, or more shapes than a "competitor." We found that, in the physical effort task, participants demonstrated faster reaction times (RTs)-a previous indicator of increased attention-in the competitive environment. Moreover, individual differences predicted the salience of competition's effect. Furthermore, male participants showed faster RTs and greater sustained effort as a result of a competitive environment, suggesting that males may be more affected by competition in physical effort tasks. However, in Experiment 2, participants remembered fewer shapes when competing, and later recalled less of these shapes during a post-test, suggesting that competition was harmful in our memory task. The different results from these two experiments suggest that competition can improve attention in a physical effort task, yet caution the use of competition in memory tasks.

The power of competition: Effects of social motivation on attention, sustained physical effort, and learning

PubMed Central

DiMenichi, Brynne C.; Tricomi, Elizabeth

2015-01-01

Competition has often been implicated as a means to improve effort-based learning and attention. Two experiments examined the effects of competition on effort and memory. In Experiment 1, participants completed a physical effort task in which they were rewarded for winning an overall percentage, or for winning a competition they believed was against another player. In Experiment 2, participants completed a memory task in which they were rewarded for remembering an overall percentage of shapes, or more shapes than a “competitor.” We found that, in the physical effort task, participants demonstrated faster reaction times (RTs)—a previous indicator of increased attention—in the competitive environment. Moreover, individual differences predicted the salience of competition’s effect. Furthermore, male participants showed faster RTs and greater sustained effort as a result of a competitive environment, suggesting that males may be more affected by competition in physical effort tasks. However, in Experiment 2, participants remembered fewer shapes when competing, and later recalled less of these shapes during a post-test, suggesting that competition was harmful in our memory task. The different results from these two experiments suggest that competition can improve attention in a physical effort task, yet caution the use of competition in memory tasks. PMID:26388801

News

NASA Astrophysics Data System (ADS)

2002-03-01

UK Awards: Teacher of Physics Awards Institute Matters: Institute of Physics Education Conference UK Awards: Top SHAP students win prizes Competition: International creative essay competition UK Awards: Kelvin Medal Particle Physics Resources: New poster from PPARC Australia: Physics Students's Day at Adventure World UK Awards: Bragg Medal winners in a FLAP ASE Annual Meeting: Particle Physics at ASE 2002 UK Grants: PPARC Awards AAPT Winter Meeting: Physics First - but do you need maths? UK In-Service Training: The Particle Physics Institutes for A-level teachers Physics on Stage 2: Not too entertaining this time, please! Scotland: A reasoned approach wins reasonable funding Institute Matters: New education manager Germany: Physics gets real: curriculum change for better teaching Research Frontiers: Let there be light - if you hang on a minute

Free recall and outdoor running: cognitive and physical demand interference.

PubMed

Epling, Samantha L; Blakely, Megan J; Russell, Paul N; Helton, William S

2016-10-01

Cognitive resource theory is a proposed explanation for people's limited ability to perform multiple tasks simultaneously. Reallocation of a restricted supply of cognitive resources to two or more tasks may be detrimental to performance on one or both tasks. Many professionals in high-risk fields, such as those engaged in firefighting, military, and search and rescue missions, face simultaneous mental and physical demands, yet little is known about the resources required to move over the natural terrain these operators may encounter. In the present research, we investigated whether interference was found between outdoor running and a word recall task. As hypothesized, a reduction in word recall was observed in the dual task compared to a recall-alone task; however, the distance run was not significantly different between the dual task and the run-alone task. Subjective reports of workload, task focus, and being "spent" (measures calculated from responses on a questionnaire) were greatest in the dual task. These results support the cognitive resource theory and have important theoretical and practical implications. Further research is required to better understand the type and extent of cognitive resources required by such physical tasks and the potential interference with simultaneous mental tasks.

The International Committee for Future Accelerators (ICFA): 1976 to the present

DOE PAGES

Rubinstein, Roy

2016-12-14

The International Committee for Future Accelerators (ICFA) has been in existence now for four decades. It plays an important role in allowing discussions by the world particle physics community on the status and future of very large particle accelerators and the particle physics and related fields associated with them. Here, this paper gives some indication of what ICFA is and does, and also describes its involvement in some of the more important developments in the particle physics field since its founding.

Watch and Learn: Seeing Is Better than Doing when Acquiring Consecutive Motor Tasks

PubMed Central

Larssen, Beverley C.; Ong, Nicole T.; Hodges, Nicola J.

2012-01-01

During motor adaptation learning, consecutive physical practice of two different tasks compromises the retention of the first. However, there is evidence that observational practice, while still effectively aiding acquisition, will not lead to interference and hence prove to be a better practice method. Observers and Actors practised in a clockwise (Task A) followed by a counterclockwise (Task B) visually rotated environment, and retention was immediately assessed. An Observe-all and Act-all group were compared to two groups who both physically practised Task A, but then only observed (ObsB) or did not see or practice Task B (NoB). The two observer groups and the NoB control group better retained Task A than Actors, although importantly only the observer groups learnt Task B. RT data and explicit awareness of the rotation suggested that the observers had acquired their respective tasks in a more strategic manner than Actor and Control groups. We conclude that observational practice benefits learning of multiple tasks more than physical practice due to the lack of updating of implicit, internal models for aiming in the former. PMID:22723909

Single Aerosol Particle Studies Using Optical Trapping Raman And Cavity Ringdown Spectroscopy

NASA Astrophysics Data System (ADS)

Gong, Z.; Wang, C.; Pan, Y. L.; Videen, G.

2017-12-01

Due to the physical and chemical complexity of aerosol particles and the interdisciplinary nature of aerosol science that involves physics, chemistry, and biology, our knowledge of aerosol particles is rather incomplete; our current understanding of aerosol particles is limited by averaged (over size, composition, shape, and orientation) and/or ensemble (over time, size, and multi-particles) measurements. Physically, single aerosol particles are the fundamental units of any large aerosol ensembles. Chemically, single aerosol particles carry individual chemical components (properties and constituents) in particle ensemble processes. Therefore, the study of single aerosol particles can bridge the gap between aerosol ensembles and bulk/surface properties and provide a hierarchical progression from a simple benchmark single-component system to a mixed-phase multicomponent system. A single aerosol particle can be an effective reactor to study heterogeneous surface chemistry in multiple phases. Latest technological advances provide exciting new opportunities to study single aerosol particles and to further develop single aerosol particle instrumentation. We present updates on our recent studies of single aerosol particles optically trapped in air using the optical-trapping Raman and cavity ringdown spectroscopy.

Georges Charpak, Particle Detectors, and Multiwire Chambers

Science.gov Websites

particle detectors used throughout experimental particle physics. In 1968, he invented and developed the the 2005 International Year of Physics (video) Top Some links on this page may take you to non-federal

Probing the frontiers of particle physics with tabletop-scale experiments.

PubMed

DeMille, David; Doyle, John M; Sushkov, Alexander O

2017-09-08

The field of particle physics is in a peculiar state. The standard model of particle theory successfully describes every fundamental particle and force observed in laboratories, yet fails to explain properties of the universe such as the existence of dark matter, the amount of dark energy, and the preponderance of matter over antimatter. Huge experiments, of increasing scale and cost, continue to search for new particles and forces that might explain these phenomena. However, these frontiers also are explored in certain smaller, laboratory-scale "tabletop" experiments. This approach uses precision measurement techniques and devices from atomic, quantum, and condensed-matter physics to detect tiny signals due to new particles or forces. Discoveries in fundamental physics may well come first from small-scale experiments of this type. Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.

The Birth of Elementary-Particle Physics.

ERIC Educational Resources Information Center

Brown, Laurie M.; Hoddeson, Lillian

1982-01-01

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

Can Grade-6 Students Understand Quarks? Probing Acceptance of the Subatomic Structure of Matter with 12-Year-Olds

ERIC Educational Resources Information Center

Wiener, Gerfried J.; Schmeling, Sascha M.; Hopf, Martin

2015-01-01

This study introduces a teaching concept based on the Standard Model of particle physics. It comprises two consecutive chapters--elementary particles and fundamental interactions. The rationale of this concept is that the fundamental principles of particle physics can run as the golden thread through the whole physics curriculum. The design…

Neural differences in processing of case particles in Japanese: an fMRI study

PubMed Central

Hashimoto, Yosuke; Yokoyama, Satoru; Kawashima, Ryuta

2014-01-01

Introduction In subject–object–verb (SOV) languages, such as Japanese, sentence processing proceeds incrementally to the late presentation of the head (verb). Japanese case particles play a crucial role in sentence processing; however, little is known about how these particles are processed. In particular, it is still unclear how the functional difference between case particles is represented in the human brain. Methods In this study, we conducted an fMRI experiment using an event-related design to directly compare brain activity during Japanese case particle processing among the nominative case ga, accusative case o, and dative case ni. Twenty five native Japanese speakers were asked to judge whether the presented character was a particle in a particle judgment task and whether the character ended with a specific vowel in a phonological judgment task, which was used as a control condition. Results A particle comparison demonstrated that the processing of ni was associated with significantly weaker brain activity than that of ga and o in the left middle frontal gyrus (MFG) and the inferior frontal gyrus (IFG). Significantly greater brain activity associated with ni relative to ga in the right IFG was also observed. Conclusion These results suggest that the Japanese case particles ga, ni, and o are represented differently in the brain. PMID:24683511

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballouz, Ronald-Louis; Richardson, Derek C.; Morishima, Ryuji

We study the B ring’s complex optical depth structure. The source of this structure may be the complex dynamics of the Keplerian shear and the self-gravity of the ring particles. The outcome of these dynamic effects depends sensitively on the collisional and physical properties of the particles. Two mechanisms can emerge that dominate the macroscopic physical structure of the ring: self-gravity wakes and viscous overstability. Here we study the interplay between these two mechanisms by using our recently developed particle collision method that allows us to better model the inter-particle contact physics. We find that for a constant ring surfacemore » density and particle internal density, particles with rough surfaces tend to produce axisymmetric ring features associated with the viscous overstability, while particles with smoother surfaces produce self-gravity wakes.« less

Effect of aerobic exercise on physical performance in patients with Alzheimer's disease.

PubMed

Sobol, Nanna Aue; Hoffmann, Kristine; Frederiksen, Kristian Steen; Vogel, Asmus; Vestergaard, Karsten; Brændgaard, Hans; Gottrup, Hanne; Lolk, Annette; Wermuth, Lene; Jakobsen, Søren; Laugesen, Lars; Gergelyffy, Robert; Høgh, Peter; Bjerregaard, Eva; Siersma, Volkert; Andersen, Birgitte Bo; Johannsen, Peter; Waldemar, Gunhild; Hasselbalch, Steen Gregers; Beyer, Nina

2016-12-01

Knowledge about the feasibility and effects of exercise programs to persons with Alzheimer's disease is lacking. This study investigated the effect of aerobic exercise on physical performance in community-dwelling persons with mild Alzheimer's disease. The single blinded multi-center RCT (ADEX) included 200 patients, median age 71 yrs (50-89). The intervention group received supervised moderate-to-high intensity aerobic exercise 1 hour × 3/week for 16 weeks. Assessments included cardiorespiratory fitness, single-task physical performance, dual-task performance and exercise self-efficacy. Significant between-group differences in change from baseline (mean [95%CI]) favored the intervention group for cardiorespiratory fitness (4.0 [2.3-5.8] ml/kg/min, P <0.0001) and exercise self-efficacy (1.7 [0.5-2.8] points, P =0.004). Furthermore, an exercise attendance of ≥66.6% resulted in significant positive effects on single-task physical performance and dual-task performance. Aerobic exercise has the potential to improve cardiorespiratory fitness, single-task physical performance, dual-task performance and exercise self-efficacy in community-dwelling patients with mild Alzheimer's disease. Copyright © 2016 the Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

Avertin®, but Not Volatile Anesthetics Addressing the Two-Pore Domain K+ Channel, TASK-1, Slows Down Cilia-Driven Particle Transport in the Mouse Trachea.

PubMed

Murtaza, Ghulam; Mermer, Petra; Pfeil, Uwe; Kummer, Wolfgang

2016-01-01

Volatile anesthetics inhibit mucociliary clearance in the airways. The two-pore domain K+ channel, TASK-1, represents one of their molecular targets in that they increase its open probability. Here, we determine whether particle transport speed (PTS) at the mucosal surface of the mouse trachea, an important factor of the cilia-driven mechanism in mucociliary clearance, is regulated by TASK-1. RT-PCR analysis revealed expression of TASK-1 mRNA in the manually dissected and laser-assisted microdissected tracheal epithelium of the mouse. Effects of anesthetics (isoflurane and Avertin®) and TASK-1 inhibitors (anandamide and A293) on ciliary activity were investigated by assessment of PTS at the mucosal surface of the explanted and opened murine trachea. Neither TASK-1 inhibitors nor isoflurane had any impact on basal and ATP-stimulated PTS. Avertin® reduced basal PTS, and ATP-stimulated PTS decreased in its presence in wild-type (WT) mice. Avertin®-induced decrease in basal PTS persisted in WT mice in the presence of TASK-1 inhibitors, and in two different strains of TASK-1 knockout mice. Our findings indicate that TASK-1 is expressed by the tracheal epithelium but is not critically involved in the regulation of tracheal PTS in mice. Avertin® reduces PTS independent of TASK-1.

The Fermi Large Area Telescope on Orbit: Event Classification, Instrument Response Functions, and Calibration

DTIC Science & Technology

2012-11-01

Experimental Physics Laboratory, Kavli Institute for Particle Astrophysics and Cosmology , Department of Physics and SLAC National Accelerator...Laboratory, Stanford University, Stanford, CA 94305, USA; echarles@slac.stanford.edu 3 Department of Physics, Center for Cosmology and Astro-Particle Physics

Children's Physical Activity and On-Task Behavior Following Active Academic Lessons: 2017 National Association for Kinesiology in Higher Education Hally Beth Poindexter Young Scholar Address

ERIC Educational Resources Information Center

Goh, Tan Leng

2017-01-01

Sitting for extended periods of time is detrimental to children's physical health and may cause off-task behavior in the classroom. The purpose of this study was to examine the effect of a classroom physical activity (PA) program, TAKE 10!®, on children's PA and on-task behavior. Participants in the program included 137 children from six classes…

Abstract ID: 103 GAMOS: Implementation of a graphical user interface for dosimetry calculation in radiotherapy.

PubMed

Abdalaoui Slimani, Faical Alaoui; Bentourkia, M'hamed

2018-01-01

There are several computer programs or combination of programs for radiation tracking and other information in tissues by using Monte Carlo simulation [1]. Among these are GEANT4 [2] programs provided as classes that can be incorporated in C++ codes to achieve different tasks in radiation interactions with matter. GEANT4 made the physics easier but requires often a long learning-curve that implies a good knowledge of C++ and the Geant4 architecture. GAMOS [3], the Geant4-based Architecture for Medicine-Oriented Simulations, facilitates the use of Geant4 by providing a script language that covers almost all the needs of a radiotherapy simulation but it is obviously out of reach of biological researchers. The aim of the present work was to report the design and development of a Graphical User Interface (GUI) for absorbed dose calculation and for particle tracking in humans, small animals and phantoms. The GUI is based on the open source GEANT4 for the physics of particle interactions, on the QT cross-platform application for combining programming commands and for display. The calculation of the absorbed dose can be performed based on 3D CT images in DICOM format, from images of phantoms or from solid volumes that can be made from any pure or composite material to be specified by its molecular formulas. The GUI has several menus relative to the emitting source which can have different shapes, positions, energy as mono- or poly-energy such as X-ray spectra; the types of particles and particle interactions; energy deposition and absorbed dose; and the output results as histograms. In conclusion, the GUI we developed can be easily used by any researcher without the need to be familiar with computer programming, and it will be freely proposed as an open source. Copyright © 2017.

Educational Information

Science.gov Websites

PDG Homepage Link Educational Information Particle Adventure Image CPEP Image Enjoy our interactive web feature: The Particle Adventure Contemporary Physics Education Projects: Educational materials educational sites on particle physics Copyright information: This page and all following and associated are

The GOL-NB program: further steps in multiple-mirror confinement research

NASA Astrophysics Data System (ADS)

Postupaev, V. V.; Batkin, V. I.; Beklemishev, A. D.; Burdakov, A. V.; Burmasov, V. S.; Chernoshtanov, I. S.; Gorbovsky, A. I.; Ivanov, I. A.; Kuklin, K. N.; Mekler, K. I.; Rovenskikh, A. F.; Sidorov, E. N.; Yurov, D. V.

2017-03-01

Physical and technical details of the GOL-NB project are presented. GOL-NB is a medium-scale multiple-mirror trap that is under development in the Budker Institute, Novosibirsk, Russia. This device will be created in several years as a deep conversion of the existing GOL-3 facility. It will consist of a central trap with two 0.75 MW neutral beams, two multiple-mirror solenoids, two expander tanks and a plasma gun that creates the start plasma. The central trap with the neutral beam injection-heated plasma is a compact gas-dynamic system. The multiple-mirror sections should decrease the power and particle losses along the magnetic field. The confinement improvement factor depends on plasma parameters and on the magnetic configuration in the multiple mirrors. The main physical task of GOL-NB is direct demonstration of the performance of multiple-mirror sections that will change equilibrium plasma parameters in the central trap. In this paper we discuss results of the scenario modeling and progress in the hardware.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graf, Norman A.; /SLAC

Maximizing the physics performance of detectors being designed for the International Linear Collider, while remaining sensitive to cost constraints, requires a powerful, efficient, and flexible simulation, reconstruction and analysis environment to study the capabilities of a large number of different detector designs. The preparation of Letters Of Intent for the International Linear Collider involved the detailed study of dozens of detector options, layouts and readout technologies; the final physics benchmarking studies required the reconstruction and analysis of hundreds of millions of events. We describe the Java-based software toolkit (org.lcsim) which was used for full event reconstruction and analysis. The componentsmore » are fully modular and are available for tasks from digitization of tracking detector signals through to cluster finding, pattern recognition, track-fitting, calorimeter clustering, individual particle reconstruction, jet-finding, and analysis. The detector is defined by the same xml input files used for the detector response simulation, ensuring the simulation and reconstruction geometries are always commensurate by construction. We discuss the architecture as well as the performance.« less

Muon Colliders: The Next Frontier

ScienceCinema

Tourun, Yagmur

2017-12-22

Muon Colliders provide a path to the energy frontier in particle physics but have been regarded to be "at least 20 years away" for 20 years. I will review recent progress in design studies and hardware R&D and show that a Muon Collider can be established as a real option for the post-LHC era if the current vigorous R&D effort revitalized by the Muon Collider Task Force at Fermilab can be supported to its conclusion. All critical technologies are being addressed and no show-stoppers have emerged. Detector backgrounds have been studied in detail and appear to be manageable and the physics can be done with existing detector technology. A muon facility can be built through a staged scenario starting from a low-energy muon source with unprecedented intensity for exquisite reach for rare processes, followed by a Neutrino Factory with ultrapure neutrino beams with unparalleled sensitivity for disentangling neutrino mixing, leading to an energy frontier Muon Collider with excellent energy resolution.

Physical Performance Tasks Required of U.S. Marines Operating in a High Altitude Cold Weather Environment.

DTIC Science & Technology

1982-07-23

readiness has not been scientifically valiated. The test batter c ists of pll-upe, sit-ups and a three-mile run e as Scoring of the PIT is arbitrary... cognitive tasks, with little information available on physical tasks cc the environmental conditions under which these tasks are to be performed. A well...environment can drastically distort operational requirements. It is difficult to convey all the encumbrances associated with maintenance of basal tasks in

Advanced Hybrid Particulate Collector Project Management Plan

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, S.J.

As the consumption of energy increases, its impact on ambient air quality has become a significant concern. Recent studies indicate that fine particles from coal combustion cause health problems as well as atmospheric visibility impairment. These problems are further compounded by the concentration of hazardous trace elements such as mercury, cadmium, selenium, and arsenic in fine particles. Therefore, a current need exists to develop superior, but economical, methods to control emissions of fine particles. Since most of the toxic metals present in coal will be in particulate form, a high level of fine- particle collection appears to be the bestmore » method of overall air toxics control. However, over 50% of mercury and a portion of selenium emissions are in vapor form and cannot be collected in particulate control devices. Therefore, this project will focus on developing technology not only to provide ultrahigh collection efficiency of particulate air toxic emissions, but also to capture vapor- phase trace metals such as mercury and selenium. Currently, the primary state-of-the-art technologies for particulate control are fabric filters (baghouses) and electrostatic precipitators (ESPs). However, they both have limitations that prevent them from achieving ultrahigh collection of fine particulate matter and vapor-phase trace metals. The objective of this project is to develop a highly reliable advanced hybrid particulate collector (AHPC) that can provide > 99.99 % particulate collection efficiency for all particle sizes between 0.01 and 50 14m, is applicable for use with all U.S. coals, and is cost-0443competitive with existing technologies. Phase I of the project is organized into three tasks: Task I - Project Management, Reporting, and Subcontract Consulting Task 2 - Modeling, Design, and Construction of 200-acfm AHPC Model Task 3 - Experimental Testing and Subcontract Consulting« less

Multi-Scale Distributed Representation for Deep Learning and its Application to b-Jet Tagging

NASA Astrophysics Data System (ADS)

Lee, Jason Sang Hun; Park, Inkyu; Park, Sangnam

2018-06-01

Recently machine learning algorithms based on deep layered artificial neural networks (DNNs) have been applied to a wide variety of high energy physics problems such as jet tagging or event classification. We explore a simple but effective preprocessing step which transforms each realvalued observational quantity or input feature into a binary number with a fixed number of digits. Each binary digit represents the quantity or magnitude in different scales. We have shown that this approach improves the performance of DNNs significantly for some specific tasks without any further complication in feature engineering. We apply this multi-scale distributed binary representation to deep learning on b-jet tagging using daughter particles' momenta and vertex information.

Machine learning action parameters in lattice quantum chromodynamics

NASA Astrophysics Data System (ADS)

Shanahan, Phiala E.; Trewartha, Daniel; Detmold, William

2018-05-01

Numerical lattice quantum chromodynamics studies of the strong interaction are important in many aspects of particle and nuclear physics. Such studies require significant computing resources to undertake. A number of proposed methods promise improved efficiency of lattice calculations, and access to regions of parameter space that are currently computationally intractable, via multi-scale action-matching approaches that necessitate parametric regression of generated lattice datasets. The applicability of machine learning to this regression task is investigated, with deep neural networks found to provide an efficient solution even in cases where approaches such as principal component analysis fail. The high information content and complex symmetries inherent in lattice QCD datasets require custom neural network layers to be introduced and present opportunities for further development.

Education of the Pierre Auger Observatory: The Cinema as a Tool in Science Education.

NASA Astrophysics Data System (ADS)

Garcia, B.; Raschia, C.

2006-08-01

The Auger collaboration's broad mission in education, outreach and public relations is coordinated in a separate task. Its goals are to encourage and support a wide range of outreach efforts that link schools and the public with the Auger scientists and the science of cosmic rays, particle physics, astrophysics in general, and associated technologies. This report focuses on recent activities and future initiatives and, especially, on a very recent professional production of two educative videos for children between 6 and 11 years: "Messengers of Space" (18 min), and for general audiences: "An Adventure of the Mind" (20 min). The use of new resources, as 2D- and 3D-animation, to teach and learn in sciences is also discussed.

Theories of quantum dissipation and nonlinear coupling bath descriptors

NASA Astrophysics Data System (ADS)

Xu, Rui-Xue; Liu, Yang; Zhang, Hou-Dao; Yan, YiJing

2018-03-01

The quest of an exact and nonperturbative treatment of quantum dissipation in nonlinear coupling environments remains in general an intractable task. In this work, we address the key issues toward the solutions to the lowest nonlinear environment, a harmonic bath coupled both linearly and quadratically with an arbitrary system. To determine the bath coupling descriptors, we propose a physical mapping scheme, together with the prescription reference invariance requirement. We then adopt a recently developed dissipaton equation of motion theory [R. X. Xu et al., Chin. J. Chem. Phys. 30, 395 (2017)], with the underlying statistical quasi-particle ("dissipaton") algebra being extended to the quadratic bath coupling. We report the numerical results on a two-level system dynamics and absorption and emission line shapes.

Performance and Results for Quartz Detector for the SuperHMS Spectrometer at Hall C Jefferson Lab

NASA Astrophysics Data System (ADS)

Griego, Benjamin F., Jr.

A quartz detector has been constructed to be part of the trigger system for the Super High Momentum Spectrometer (SHMS). The SHMS will play a pivotal role in carrying out the 12 -- GeV physics program at Hal -- C Jefferson Lab. The quartz hodoscope consists of twenty one fused silica bars. Each bar is 125 cm long, 5.5 cm wide, 2.5 cm thick, and is viewed by a UV -- sensitive PMT on each end. The quartz hodoscope's task is to provide a clean detection of charged particles, a high level of background suppression, and an accurate tracking efficiency determination. Initial test results of the quartz detectors which include light yield and position resolution will be presented.

Physical fatigue increases neural activation during eyes-closed state: a magnetoencephalography study.

PubMed

Tanaka, Masaaki; Ishii, Akira; Watanabe, Yasuyoshi

2015-11-05

Fatigue, defined as difficulty initiating or sustaining voluntary activities, can be classified as physical or mental. In this study, we use magnetoencephalography (MEG) to quantify the effect of physical fatigue on neural activity under the condition of simulated physical load. Thirteen healthy right-handed male volunteers participated in this study. The experiment consisted of one fatigue-inducing physical task session performed between two MEG sessions. During the 10-min physical task session, participants performed maximum-effort handgrips with the left hand lasting 1 s every 4 s; during MEG sessions, 3-min recordings were made during the eyes-closed state. MEG data were analyzed using narrow-band adaptive spatial filtering methods. Alpha-frequency band (8-13 Hz) power in the left postcentral gyrus, precentral gyrus, and middle frontal gyrus (Brodmann's areas 1, 2, 3, 4, 6, and 46) were decreased after performing the physical fatigue-inducing task. These results show that performing the physical fatigue-inducing task caused activation of the left sensorimotor and prefrontal areas, manifested as decreased alpha-frequency band power in these brain areas. Our results increase understanding of the neural mechanisms of physical fatigue.

Verb Particle and Preposition Acquisition in Language-Impaired Preschoolers.

ERIC Educational Resources Information Center

Watkins, Ruth V.; Rice, Mabel L.

1991-01-01

This study examined the acquisition of verb particles and prepositions in language-impaired, language-matched, and age-matched preschool children (total n=42). Results indicated that the use of verb particles constituted a particularly challenging task for the language-impaired subjects relative to both the age-matched and language-matched peers.…

Review of Particle Physics

NASA Astrophysics Data System (ADS)

Beringer, J.; Arguin, J.-F.; Barnett, R. M.; Copic, K.; Dahl, O.; Groom, D. E.; Lin, C.-J.; Lys, J.; Murayama, H.; Wohl, C. G.; Yao, W.-M.; Zyla, P. A.; Amsler, C.; Antonelli, M.; Asner, D. M.; Baer, H.; Band, H. R.; Basaglia, T.; Bauer, C. W.; Beatty, J. J.; Belousov, V. I.; Bergren, E.; Bernardi, G.; Bertl, W.; Bethke, S.; Bichsel, H.; Biebel, O.; Blucher, E.; Blusk, S.; Brooijmans, G.; Buchmueller, O.; Cahn, R. N.; Carena, M.; Ceccucci, A.; Chakraborty, D.; Chen, M.-C.; Chivukula, R. S.; Cowan, G.; D'Ambrosio, G.; Damour, T.; de Florian, D.; de Gouvêa, A.; DeGrand, T.; de Jong, P.; Dissertori, G.; Dobrescu, B.; Doser, M.; Drees, M.; Edwards, D. A.; Eidelman, S.; Erler, J.; Ezhela, V. V.; Fetscher, W.; Fields, B. D.; Foster, B.; Gaisser, T. K.; Garren, L.; Gerber, H.-J.; Gerbier, G.; Gherghetta, T.; Golwala, S.; Goodman, M.; Grab, C.; Gritsan, A. V.; Grivaz, J.-F.; Grünewald, M.; Gurtu, A.; Gutsche, T.; Haber, H. E.; Hagiwara, K.; Hagmann, C.; Hanhart, C.; Hashimoto, S.; Hayes, K. G.; Heffner, M.; Heltsley, B.; Hernández-Rey, J. J.; Hikasa, K.; Höcker, A.; Holder, J.; Holtkamp, A.; Huston, J.; Jackson, J. D.; Johnson, K. F.; Junk, T.; Karlen, D.; Kirkby, D.; Klein, S. R.; Klempt, E.; Kowalewski, R. V.; Krauss, F.; Kreps, M.; Krusche, B.; Kuyanov, Yu. V.; Kwon, Y.; Lahav, O.; Laiho, J.; Langacker, P.; Liddle, A.; Ligeti, Z.; Liss, T. M.; Littenberg, L.; Lugovsky, K. S.; Lugovsky, S. B.; Mannel, T.; Manohar, A. V.; Marciano, W. J.; Martin, A. D.; Masoni, A.; Matthews, J.; Milstead, D.; Miquel, R.; Mönig, K.; Moortgat, F.; Nakamura, K.; Narain, M.; Nason, P.; Navas, S.; Neubert, M.; Nevski, P.; Nir, Y.; Olive, K. A.; Pape, L.; Parsons, J.; Patrignani, C.; Peacock, J. A.; Petcov, S. T.; Piepke, A.; Pomarol, A.; Punzi, G.; Quadt, A.; Raby, S.; Raffelt, G.; Ratcliff, B. N.; Richardson, P.; Roesler, S.; Rolli, S.; Romaniouk, A.; Rosenberg, L. J.; Rosner, J. L.; Sachrajda, C. T.; Sakai, Y.; Salam, G. P.; Sarkar, S.; Sauli, F.; Schneider, O.; Scholberg, K.; Scott, D.; Seligman, W. G.; Shaevitz, M. H.; Sharpe, S. R.; Silari, M.; Sjöstrand, T.; Skands, P.; Smith, J. G.; Smoot, G. F.; Spanier, S.; Spieler, H.; Stahl, A.; Stanev, T.; Stone, S. L.; Sumiyoshi, T.; Syphers, M. J.; Takahashi, F.; Tanabashi, M.; Terning, J.; Titov, M.; Tkachenko, N. P.; Törnqvist, N. A.; Tovey, D.; Valencia, G.; van Bibber, K.; Venanzoni, G.; Vincter, M. G.; Vogel, P.; Vogt, A.; Walkowiak, W.; Walter, C. W.; Ward, D. R.; Watari, T.; Weiglein, G.; Weinberg, E. J.; Wiencke, L. R.; Wolfenstein, L.; Womersley, J.; Woody, C. L.; Workman, R. L.; Yamamoto, A.; Zeller, G. P.; Zenin, O. V.; Zhang, J.; Zhu, R.-Y.; Harper, G.; Lugovsky, V. S.; Schaffner, P.

2012-07-01

This biennial Review summarizes much of particle physics. Using data from previous editions, plus 2658 new measurements from 644 papers, we list, evaluate, and average measured properties of gauge bosons, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as Higgs bosons, heavy neutrinos, and supersymmetric particles. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as the Standard Model, particle detectors, probability, and statistics. Among the 112 reviews are many that are new or heavily revised including those on Heavy-Quark and Soft-Collinear Effective Theory, Neutrino Cross Section Measurements, Monte Carlo Event Generators, Lattice QCD, Heavy Quarkonium Spectroscopy, Top Quark, Dark Matter, Vcb & Vub, Quantum Chromodynamics, High-Energy Collider Parameters, Astrophysical Constants, Cosmological Parameters, and Dark Matter.A booklet is available containing the Summary Tables and abbreviated versions of some of the other sections of this full Review. All tables, listings, and reviews (and errata) are also available on the Particle Data Group website: http://pdg.lbl.gov/.The 2012 edition of Review of Particle Physics is published for the Particle Data Group as article 010001 in volume 86 of Physical Review D.This edition should be cited as: J. Beringer et al. (Particle Data Group), Phys. Rev. D 86, 010001 (2012).

Effect of physical workload and modality of information presentation on pattern recognition and navigation task performance by high-fit young males.

PubMed

Zahabi, Maryam; Zhang, Wenjuan; Pankok, Carl; Lau, Mei Ying; Shirley, James; Kaber, David

2017-11-01

Many occupations require both physical exertion and cognitive task performance. Knowledge of any interaction between physical demands and modalities of cognitive task information presentation can provide a basis for optimising performance. This study examined the effect of physical exertion and modality of information presentation on pattern recognition and navigation-related information processing. Results indicated males of equivalent high fitness, between the ages of 18 and 34, rely more on visual cues vs auditory or haptic for pattern recognition when exertion level is high. We found that navigation response time was shorter under low and medium exertion levels as compared to high intensity. Navigation accuracy was lower under high level exertion compared to medium and low levels. In general, findings indicated that use of the haptic modality for cognitive task cueing decreased accuracy in pattern recognition responses. Practitioner Summary: An examination was conducted on the effect of physical exertion and information presentation modality in pattern recognition and navigation. In occupations requiring information presentation to workers, who are simultaneously performing a physical task, the visual modality appears most effective under high level exertion while haptic cueing degrades performance.

Review of particle physics

DOE PAGES

Olive, K. A.

2016-10-01

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders,more » Probability and Statistics. As a result, among the 117 reviews are many that are new or heavily revised, including those on Pentaquarks and Inflation.« less

Particle astronomy and particle physics from the moon - The particle observatory

NASA Technical Reports Server (NTRS)

Wilson, Thomas L.

1990-01-01

Promising experiments from the moon using particle detectors are discussed, noting the advantage of the large flux collecting power Pc offered by the remote, stable environment of a lunar base. An observatory class of particle experiments is presented, based upon proposals at NASA's recent Stanford workshop. They vary from neutrino astronomy, particle astrophysics, and cosmic ray experiments to space physics and fundamental physics experiments such as proton decay and 'table-top' arrays. This research is background-limited on earth, and it is awkward and unrealistic in earth orbit, but is particularly suited for the moon where Pc can be quite large and the instrumentation is not subject to atmospheric erosion as it is (for large t) in low earth orbit.

Review of particle physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Olive, K. A.

The Review summarizes much of particle physics and cosmology. Using data from previous editions, plus 3,062 new measurements from 721 papers, we list, evaluate, and average measured properties of gauge bosons and the recently discovered Higgs boson, leptons, quarks, mesons, and baryons. We summarize searches for hypothetical particles such as supersymmetric particles, heavy bosons, axions, dark photons, etc. All the particle properties and search limits are listed in Summary Tables. We also give numerous tables, figures, formulae, and reviews of topics such as Higgs Boson Physics, Supersymmetry, Grand Unified Theories, Neutrino Mixing, Dark Energy, Dark Matter, Cosmology, Particle Detectors, Colliders,more » Probability and Statistics. As a result, among the 117 reviews are many that are new or heavily revised, including those on Pentaquarks and Inflation.« less

The Effects of Word Prediction on Writing Fluency for Students with Physical Disabilities

ERIC Educational Resources Information Center

Mezei, Peter John

2009-01-01

Writing is a multifaceted, complex task that involves interaction between physical and cognitive skills. Individuals with physical disabilities vary in terms of both their physical and cognitive abilities. Often they must overcome one or more significant barriers in order to engage in the task of writing. Minimizing or eliminating barriers is…

Numerical Analysis of Temperature Gradients and Interface Shape During Directional Solidification of Al and Al-Cu Alloy Under Microgravity Conditions

NASA Technical Reports Server (NTRS)

Bune, Andris V.; Sen, Subhayu; Mukherjee, Sundeep; Catalina, Adrian; Stefanescu, Doru M.

1999-01-01

Numerical modeling was undertaken to analyze the influence of radial thermal gradient on solid/liquid (s/1) interface shape and convection patterns during solidification of pure Al and Al-4 wt% Cu alloy. The objective of the numerical task was to predict the influence of convective velocity on an insoluble particle near a s/l interface. These predictions would then be used to define the minimum gravity level (g) required to investigate the fundamental physics of interaction between a particle and a s/I interface. To satisfy this objective, steady state calculations were performed for different gravity levels and orientations with the gravity vector. ne furnace configuration used in this analysis is the proposed International Space Station Furnace, Quench Module Insert (QMI) 1. Results from a thermal model of the furnace core were used as initial boundary conditions for solidification modeling. General model of binary alloy solidification was based on the finite element code FIDAP. It was found that for the worst case orientation of 90 degrees with the gravity vector and a g level of 10(exp -4)g(sub o) (g(sub o) = 9.8 m/s(exp 2)) the dominant forces acting on the particle would be the fundamental drag and interfacial forces.

Use of Hilbert Curves in Parallelized CUDA code: Interaction of Interstellar Atoms with the Heliosphere

NASA Astrophysics Data System (ADS)

Destefano, Anthony; Heerikhuisen, Jacob

2015-04-01

Fully 3D particle simulations can be a computationally and memory expensive task, especially when high resolution grid cells are required. The problem becomes further complicated when parallelization is needed. In this work we focus on computational methods to solve these difficulties. Hilbert curves are used to map the 3D particle space to the 1D contiguous memory space. This method of organization allows for minimized cache misses on the GPU as well as a sorted structure that is equivalent to an octal tree data structure. This type of sorted structure is attractive for uses in adaptive mesh implementations due to the logarithm search time. Implementations using the Message Passing Interface (MPI) library and NVIDIA's parallel computing platform CUDA will be compared, as MPI is commonly used on server nodes with many CPU's. We will also compare static grid structures with those of adaptive mesh structures. The physical test bed will be simulating heavy interstellar atoms interacting with a background plasma, the heliosphere, simulated from fully consistent coupled MHD/kinetic particle code. It is known that charge exchange is an important factor in space plasmas, specifically it modifies the structure of the heliosphere itself. We would like to thank the Alabama Supercomputer Authority for the use of their computational resources.

Standard Model of Particle Physics--a health physics perspective.

PubMed

Bevelacqua, J J

2010-11-01

The Standard Model of Particle Physics is reviewed with an emphasis on its relationship to the physics supporting the health physics profession. Concepts important to health physics are emphasized and specific applications are presented. The capability of the Standard Model to provide health physics relevant information is illustrated with application of conservation laws to neutron and muon decay and in the calculation of the neutron mean lifetime.

Hybrid Monte Carlo/deterministic methods for radiation shielding problems

NASA Astrophysics Data System (ADS)

Becker, Troy L.

For the past few decades, the most common type of deep-penetration (shielding) problem simulated using Monte Carlo methods has been the source-detector problem, in which a response is calculated at a single location in space. Traditionally, the nonanalog Monte Carlo methods used to solve these problems have required significant user input to generate and sufficiently optimize the biasing parameters necessary to obtain a statistically reliable solution. It has been demonstrated that this laborious task can be replaced by automated processes that rely on a deterministic adjoint solution to set the biasing parameters---the so-called hybrid methods. The increase in computational power over recent years has also led to interest in obtaining the solution in a region of space much larger than a point detector. In this thesis, we propose two methods for solving problems ranging from source-detector problems to more global calculations---weight windows and the Transform approach. These techniques employ sonic of the same biasing elements that have been used previously; however, the fundamental difference is that here the biasing techniques are used as elements of a comprehensive tool set to distribute Monte Carlo particles in a user-specified way. The weight window achieves the user-specified Monte Carlo particle distribution by imposing a particular weight window on the system, without altering the particle physics. The Transform approach introduces a transform into the neutron transport equation, which results in a complete modification of the particle physics to produce the user-specified Monte Carlo distribution. These methods are tested in a three-dimensional multigroup Monte Carlo code. For a basic shielding problem and a more realistic one, these methods adequately solved source-detector problems and more global calculations. Furthermore, they confirmed that theoretical Monte Carlo particle distributions correspond to the simulated ones, implying that these methods can be used to achieve user-specified Monte Carlo distributions. Overall, the Transform approach performed more efficiently than the weight window methods, but it performed much more efficiently for source-detector problems than for global problems.

Body mass index predicts selected physical fitness attributes but is not associated with performance on military relevant tasks in U.S. Army Soldiers.

PubMed

Pierce, Joseph R; DeGroot, David W; Grier, Tyson L; Hauret, Keith G; Nindl, Bradley C; East, Whitfield B; McGurk, Michael S; Jones, Bruce H

2017-11-01

Army body composition standards are based upon validated criteria; however, certain field-expedient methodologies (e.g., weight-for-height, body mass index [BMI]) may disqualify individuals from service who may otherwise excel on physical performance and military-relevant tasks. The purpose was to assess soldier physical performance and military-specific task/fitness performance stratified by BMI. Cross-sectional observational study. Male (n=275) and female (n=46) soldiers performed a wide-array of physical fitness tests and military-specific tasks, including the Army physical fitness test (APFT). Within-sex performance data were analyzed by BMI tertile stratification or by Army Body Composition Program (ABCP) weight-for-height (calculated BMI) screening standards using ANOVA/Tukey post-hoc or independent t-tests, respectively. BMI stratification (higher vs. lower BMI) was associated with significant improvements in muscular strength and power, but also with decrements in speed/agility in male and female soldiers. Within the military specific tasks, a higher BMI was associated with an increased APFT 2-Mile Run time; however, performance on a 1600-m Loaded March or a Warrior Task and Battle Drill obstacle course was not related to BMI in either sex. Male and Female soldiers who did not meet ABCP screening standards demonstrated a slower 2-Mile Run time; however, not meeting the ABCP BMI standard only affected a minimal number (∼6%) of soldiers' ability to pass the APFT. Military body composition standards require a careful balance between physical performance, health, and military readiness. Allowances should be considered where tradeoffs exist between body composition classifications and performance on physical tasks with high military relevance. Published by Elsevier Ltd.

Fermilab | Science at Fermilab | Experiments & Projects | Cosmic Frontier

Science.gov Websites

Proposed Projects and Experiments Fermilab's Tevatron Questions for the Universe Theory Computing High Answers Submit a Question Frontiers of Particle Physics Benefits to Society Benefits to Society Medicine Inquiring Minds Questions About Physics Other High-Energy Physics Sites More About Particle Physics Library

Advanced Level Physics Students' Conceptions of Quantum Physics.

ERIC Educational Resources Information Center

Mashhadi, Azam

This study addresses questions about particle physics that focus on the nature of electrons. Speculations as to whether they are more like particles or waves or like neither illustrate the difficulties with which students are confronted when trying to incorporate the concepts of quantum physics into their overall conceptual framework. Such…

Inerton fields: very new ideas on fundamental physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krasnoholovets, Volodymyr

2010-12-22

Modern theories of everything, or theories of the grand unification of all physical interactions, try to describe the whole world starting from the first principles of quantum theory. However, the first principles operate with undetermined notions, such as the wave {psi}-function, particle, lepton and quark, de Broglie and Compton wavelengths, mass, electric charge, spin, electromagnetic field, photon, gravitation, physical vacuum, space, etc. From a logical point of view this means that such modern approach to the theory of everything is condemned to failure... Thus, what should we suggest to improve the situation? It seems quite reasonable to develop initially amore » theory of something, which will be able to clarify the major fundamental notions (listed above) that physics operates with every day. What would be a starting point in such approach? Of course a theory of space as such, because particles and all physical fields emerge just from space. After that, when a particle and fields (and hence the fields' carriers) are well defined and introduced in the well defined physical space, different kinds of interactions can be proposed and investigated. Moreover, we must also allow for a possible interaction of a created particle with the space that generated the appearance of the particle. The mathematical studies of Michel Bounias and the author have shown what the real physical space is, how the space is constituted, how it is arranged and what its elements are. Having constructed the real physical space we can then derive whatever we wish, in particular, such basic notions as mass, particle and charge. How are mechanics of such objects (a massive particle, a charged massive particle) organised? The appropriate theory of motion has been called a sub microscopic mechanics of particles, which is developed in the real physical space, not an abstract phase space, as conventional quantum mechanics does. A series of questions arise: can these two mechanics (submicroscopic and conventional quantum mechanics) be unified?, what can such unification bring new for us?, can such submicroscopic mechanics be a starting point for the derivation of the phenomenon of gravity?, can this new theory be a unified physical theory?, does the theory allow experimental verification? These major points have been clarified in detail. And, perhaps, the most intriguing aspect of the theory is the derivation of a new physical field associated with the notion of mass (or rather inertia of a particle, which has been called the inerton field and which represents a real sense of the particle's wave {psi}-function). This field emerges by analogy with the electromagnetic field associated with the notion of the electric charge. Yes, the postulated inerton field has being tested in a series of different experiments. Even more, the inerton field might have a number of practical applications...« less

Development of students' interest in particle physics as effect of participating in a Masterclass

NASA Astrophysics Data System (ADS)

Gedigk, Kerstin; Pospiech, Gesche

2016-05-01

The International Hands On Particle Physics Masterclasses are enjoying increasing popularity worldwide every year. In Germany a national program was brought to live in 2010, which offers these appreciated events to whole classes or courses of high school students all over the year. These events were evaluated concerning the issues of students' interest in particle physics and their perception of the events. How several interest variables interact with each other and the perception of the events is answered by structural equation modelling (sect. 5.2). The results give information about the events' effects on the students' interest development in particle physics, show which event features are important ( e.g. the authenticity) and give information about practical approaches to improve the effects of the Masterclasses. Section 5.3 deals with a group of participants which have a high interest in particle physics 6-8 weeks after the participation. The number of these students is remarkable large, with 26% of all participants. The investigation of this group shows that the Masterclass participation has the same positive effect on both sexes and all levels of physics education.

Physics and astrophysics from a lunar base; Proceedings of the 1st NASA Workshop, Stanford, CA, May 19, 20, 1989

NASA Technical Reports Server (NTRS)

Potter, A. E. (Editor); Wilson, T. L. (Editor)

1990-01-01

The present conference on physics and astrophysics from a lunar base encompasses space physics, cosmic ray physics, neutrino physics, experiments in gravitation and general relativity, gravitational radiation physics, cosmic background radiation, particle astrophysics, surface physics, and the physics of gamma rays and X-rays. Specific issues addressed include space-plasma physics research at a lunar base, prospects for neutral particle imaging, the atmosphere as particle detector, medium- and high-energy neutrino physics from a lunar base, muons on the moon, a search for relic supernovae antineutrinos, and the use of clocks in satellites orbiting the moon to test general relativity. Also addressed are large X-ray-detector arrays for physics experiments on the moon, and the measurement of proton decay, arcsec-source locations, halo dark matter and elemental abundances above 10 exp 15 eV at a lunar base.

Joint Task Force on Undergraduate Physics Programs

NASA Astrophysics Data System (ADS)

This session will focus on the guidelines and recommendations being developed by the APS/AAPT Joint Task Force on Undergraduate Physics Programs. J-TUPP is studying how undergraduate physics programs might better prepare physics majors for diverse careers. The guidelines and recommendations will focus on curricular content, flexible tracks, pedagogical methods, research experiences and internships, the development of professional skills, and enhanced advising and mentoring for all physics majors.

PARTICLE PHYSICS: CERN Collider Glimpses Supersymmetry--Maybe.

PubMed

Seife, C

2000-07-14

Last week, particle physicists at the CERN laboratory in Switzerland announced that by smashing together matter and antimatter in four experiments, they detected an unexpected effect in the sprays of particles that ensued. The anomaly is subtle, and physicists caution that it might still be a statistical fluke. If confirmed, however, it could mark the long-sought discovery of a whole zoo of new particles--and the end of a long-standing model of particle physics.

Assessing Abuse Risk beyond Self-Report: Analog Task of Acceptability of Parent-Child Aggression

ERIC Educational Resources Information Center

Rodriguez, Christina M.; Russa, Mary Bower; Harmon, Nancy

2011-01-01

Objectives: The present investigation reports on the development and initial validation of a new analog task, the Parent-Child Aggression Acceptability Movie Task (P-CAAM), intended to assess respondents' acceptance of parent-child aggression, including both physical discipline and physical abuse. Methods: Two independent samples were utilized to…

Markov Task Network: A Framework for Service Composition under Uncertainty in Cyber-Physical Systems.

PubMed

Mohammed, Abdul-Wahid; Xu, Yang; Hu, Haixiao; Agyemang, Brighter

2016-09-21

In novel collaborative systems, cooperative entities collaborate services to achieve local and global objectives. With the growing pervasiveness of cyber-physical systems, however, such collaboration is hampered by differences in the operations of the cyber and physical objects, and the need for the dynamic formation of collaborative functionality given high-level system goals has become practical. In this paper, we propose a cross-layer automation and management model for cyber-physical systems. This models the dynamic formation of collaborative services pursuing laid-down system goals as an ontology-oriented hierarchical task network. Ontological intelligence provides the semantic technology of this model, and through semantic reasoning, primitive tasks can be dynamically composed from high-level system goals. In dealing with uncertainty, we further propose a novel bridge between hierarchical task networks and Markov logic networks, called the Markov task network. This leverages the efficient inference algorithms of Markov logic networks to reduce both computational and inferential loads in task decomposition. From the results of our experiments, high-precision service composition under uncertainty can be achieved using this approach.

Theoretical analysis of the influence of aerosol size distribution and physical activity on particle deposition pattern in human lungs.

PubMed

Voutilainen, Arto; Kaipio, Jari P; Pekkanen, Juha; Timonen, Kirsi L; Ruuskanen, Juhani

2004-01-01

A theoretical comparison of modeled particle depositions in the human respiratory tract was performed by taking into account different particle number and mass size distributions and physical activity in an urban environment. Urban-air data on particulate concentrations in the size range 10 nm-10 microm were used to estimate the hourly average particle number and mass size distribution functions. The functions were then combined with the deposition probability functions obtained from a computerized ICRP 66 deposition model of the International Commission on Radiological Protection to calculate the numbers and masses of particles deposited in five regions of the respiratory tract of a male adult. The man's physical activity and minute ventilation during the day were taken into account in the calculations. Two different mass and number size distributions of aerosol particles with equal (computed) <10 microm particle mass concentrations gave clearly different deposition patterns in the central and peripheral regions of the human respiratory tract. The deposited particle numbers and masses were much higher during the day (0700-1900) than during the night (1900-0700) because an increase in physical activity and ventilation were temporally associated with highly increased traffic-derived particles in urban outdoor air. In future analyses of the short-term associations between particulate air pollution and health, it would not only be important to take into account the outdoor-to-indoor penetration of different particle sizes and human time-activity patterns, but also actual lung deposition patterns and physical activity in significant microenvironments.

Press Room

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Comparative Cognitive Task Analyses of Experimental Science and Instructional Laboratory Courses

NASA Astrophysics Data System (ADS)

Wieman, Carl

2015-09-01

Undergraduate instructional labs in physics generate intense opinions. Their advocates are passionate as to their importance for teaching physics as an experimental activity and providing "hands-on" learning experiences, while their detractors (often but not entirely students) offer harsh criticisms that they are pointless, confusing and unsatisfying, and "cookbook." Here, both to help understand the reason for such discrepant views and to aid in the design of instructional lab courses, I compare the mental tasks or types of thinking ("cognitive task analysis") associated with a physicist doing tabletop experimental research with the cognitive tasks of students in an introductory physics instructional lab involving traditional verification/confirmation exercises.

Exploring the Relationship of Task Performance and Physical and Cognitive Fatigue During a Daylong Light Precision Task.

PubMed

Yung, Marcus; Manji, Rahim; Wells, Richard P

2017-11-01

Our aim was to explore the relationship between fatigue and operation system performance during a simulated light precision task over an 8-hr period using a battery of physical (central and peripheral) and cognitive measures. Fatigue may play an important role in the relationship between poor ergonomics and deficits in quality and productivity. However, well-controlled laboratory studies in this area have several limitations, including the lack of work relevance of fatigue exposures and lack of both physical and cognitive measures. There remains a need to understand the relationship between physical and cognitive fatigue and task performance at exposure levels relevant to realistic production or light precision work. Errors and fatigue measures were tracked over the course of a micropipetting task. Fatigue responses from 10 measures and errors in pipetting technique, precision, and targeting were submitted to principal component analysis to descriptively analyze features and patterns. Fatigue responses and error rates contributed to three principal components (PCs), accounting for 50.9% of total variance. Fatigue responses grouped within the three PCs reflected central and peripheral upper extremity fatigue, postural sway, and changes in oculomotor behavior. In an 8-hr light precision task, error rates shared similar patterns to both physical and cognitive fatigue responses, and/or increases in arousal level. The findings provide insight toward the relationship between fatigue and operation system performance (e.g., errors). This study contributes to a body of literature documenting task errors and fatigue, reflecting physical (both central and peripheral) and cognitive processes.

A facility to search for hidden particles at the CERN SPS: the SHiP physics case.

PubMed

Alekhin, Sergey; Altmannshofer, Wolfgang; Asaka, Takehiko; Batell, Brian; Bezrukov, Fedor; Bondarenko, Kyrylo; Boyarsky, Alexey; Choi, Ki-Young; Corral, Cristóbal; Craig, Nathaniel; Curtin, David; Davidson, Sacha; de Gouvêa, André; Dell'Oro, Stefano; deNiverville, Patrick; Bhupal Dev, P S; Dreiner, Herbi; Drewes, Marco; Eijima, Shintaro; Essig, Rouven; Fradette, Anthony; Garbrecht, Björn; Gavela, Belen; Giudice, Gian F; Goodsell, Mark D; Gorbunov, Dmitry; Gori, Stefania; Grojean, Christophe; Guffanti, Alberto; Hambye, Thomas; Hansen, Steen H; Helo, Juan Carlos; Hernandez, Pilar; Ibarra, Alejandro; Ivashko, Artem; Izaguirre, Eder; Jaeckel, Joerg; Jeong, Yu Seon; Kahlhoefer, Felix; Kahn, Yonatan; Katz, Andrey; Kim, Choong Sun; Kovalenko, Sergey; Krnjaic, Gordan; Lyubovitskij, Valery E; Marcocci, Simone; Mccullough, Matthew; McKeen, David; Mitselmakher, Guenakh; Moch, Sven-Olaf; Mohapatra, Rabindra N; Morrissey, David E; Ovchynnikov, Maksym; Paschos, Emmanuel; Pilaftsis, Apostolos; Pospelov, Maxim; Reno, Mary Hall; Ringwald, Andreas; Ritz, Adam; Roszkowski, Leszek; Rubakov, Valery; Ruchayskiy, Oleg; Schienbein, Ingo; Schmeier, Daniel; Schmidt-Hoberg, Kai; Schwaller, Pedro; Senjanovic, Goran; Seto, Osamu; Shaposhnikov, Mikhail; Shchutska, Lesya; Shelton, Jessie; Shrock, Robert; Shuve, Brian; Spannowsky, Michael; Spray, Andy; Staub, Florian; Stolarski, Daniel; Strassler, Matt; Tello, Vladimir; Tramontano, Francesco; Tripathi, Anurag; Tulin, Sean; Vissani, Francesco; Winkler, Martin W; Zurek, Kathryn M

2016-12-01

This paper describes the physics case for a new fixed target facility at CERN SPS. The SHiP (search for hidden particles) experiment is intended to hunt for new physics in the largely unexplored domain of very weakly interacting particles with masses below the Fermi scale, inaccessible to the LHC experiments, and to study tau neutrino physics. The same proton beam setup can be used later to look for decays of tau-leptons with lepton flavour number non-conservation, [Formula: see text] and to search for weakly-interacting sub-GeV dark matter candidates. We discuss the evidence for physics beyond the standard model and describe interactions between new particles and four different portals-scalars, vectors, fermions or axion-like particles. We discuss motivations for different models, manifesting themselves via these interactions, and how they can be probed with the SHiP experiment and present several case studies. The prospects to search for relatively light SUSY and composite particles at SHiP are also discussed. We demonstrate that the SHiP experiment has a unique potential to discover new physics and can directly probe a number of solutions of beyond the standard model puzzles, such as neutrino masses, baryon asymmetry of the Universe, dark matter, and inflation.

Children's motivation in elementary physical education: an expectancy-value model of achievement choice.

PubMed

Xiang, Ping; McBride, Ron; Guan, Jianmin; Solmon, Melinda

2003-03-01

This study examined children's motivation in elementary physical education within an expectancy-value model developed by Eccles and her colleagues. Four hundred fourteen students in second and fourth grades completed questionnaires assessing their expectancy-related beliefs, subjective task values, and intention for future participation in physical education. Results indicated that expectancy-related beliefs and subjective task values were clearly distinguishable from one another across physical education and throwing. The two constructs were related to each other positively. Children's intention for future participation in physical education was positively associated with their subjective task values and/or expectancy-related beliefs. Younger children had higher motivation for learning in physical education than older children. Gender differences emerged and the findings provided empirical evidence supporting the validity of the expectancy-value model in elementary physical education.

Joint Task Force on Undergraduate Physics Programs (J-TUPP): Overview and Major Findings

NASA Astrophysics Data System (ADS)

Heron, Paula

2016-03-01

The Joint Task Force on Undergraduate Physics Programs (JTUPP) was formed in response to growing awareness in the physics community that physics majors pursue a wide range of careers after graduation, with very few ending up in academia. The task force is charged with identifying the skills and knowledge that undergraduate physics degree holders should possess to be well prepared for a diverse set of careers, and providing guidance for physicists considering revising the undergraduate curriculum to improve the education of a diverse student population. Task force members represent large and small universities, professional societies, and industry, and have expertise in a broad range of areas including entrepreneurship, physics education research and systemic change in education. We reviewed employment data, surveys of employers, and reports generated by other disciplines. We also met with physicists in selected industries to get their views on the strengths and weaknesses of physics graduates, commissioned a series of interviews with recent physics graduates employed in the private sector, and identified exemplary programs that ensure that all of their students are well prepared to pursue a wide range of career paths. The findings and recommendations will be summarized.

Theoretical Studies of Alfven Waves and Energetic Particle Physics in Fusion Plasmas

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Liu

This report summarizes major theoretical findings in the linear as well as nonlinear physics of Alfvén waves and energetic particles in magnetically confined fusion plasmas. On the linear physics, a variational formulation, based on the separation of singular and regular spatial scales, for drift-Alfvén instabilities excited by energetic particles is established. This variational formulation is then applied to derive the general fishbone-like dispersion relations corresponding to the various Alfvén eigenmodes and energetic-particle modes. It is further employed to explore in depth the low-frequency Alfvén eigenmodes and demonstrate the non-perturbative nature of the energetic particles. On the nonlinear physics, new novelmore » findings are obtained on both the nonlinear wave-wave interactions and nonlinear wave-energetic particle interactions. It is demonstrated that both the energetic particles and the fine radial mode structures could qualitatively affect the nonlinear evolution of Alfvén eigenmodes. Meanwhile, a theoretical approach based on the Dyson equation is developed to treat self-consistently the nonlinear interactions between Alfvén waves and energetic particles, and is then applied to explain simulation results of energetic-particle modes. Relevant list of journal publications on the above findings is also included.« less

Distance educational technologies as means of increase of student’s motivation in the learning of general physics course

NASA Astrophysics Data System (ADS)

Gubkin, M. K.; Ivanov, D. A.; Ivanova, I. V.; Spivak, V. S.

2017-11-01

The Department of General physics and nuclear fusion, National Research University “Moscow Power Engineering Institute”, developed a set of tests (over 1000 questions) for the current control of knowledge of students in the section “Electricity and magnetism” of the General physics course using the internet distance learning system “Prometheus” (fourth generation). Under this section of the proposed test tasks are divided into sections corresponding to the topics section. These tasks include quality issues, design tasks, tasks with a choice of answers (one of many, many of many), the job with the selection region in the figure, tasks with detailed answer. The variety of tasks allows the teacher not only to objectively assess the student acquired knowledge but also to develop his problem-solving skills, to learn to be fluent in theory. The results of testing conducted for several years, show the high interest of students in the repeated independent execution of tasks and correlate well with the results of intermediate certification (exams).

Particle physics for primary schools—enthusing future physicists

NASA Astrophysics Data System (ADS)

Pavlidou, M.; Lazzeroni, C.

2016-09-01

In recent years, the realisation that children make decisions and choices about subjects they like in primary school, became widely understood. For this reason academic establishments focus some of their public engagement activities towards the younger ages. Taking advantage of Professor Lazzeroni’s long-standing experience in particle physics research, during the last academic year we designed and trialled a particle physics workshop for primary schools. The workshop allows young children (ages 8-11) to learn the world of fundamental particles, use creative design to make particle models. The workshop has already been trialled in many primary schools, receiving very positive evaluation. The initial resources were reviewed and improved, based on the feedback received from school teachers and communicators.

Computer measurement of particle sizes in electron microscope images

NASA Technical Reports Server (NTRS)

Hall, E. L.; Thompson, W. B.; Varsi, G.; Gauldin, R.

1976-01-01

Computer image processing techniques have been applied to particle counting and sizing in electron microscope images. Distributions of particle sizes were computed for several images and compared to manually computed distributions. The results of these experiments indicate that automatic particle counting within a reasonable error and computer processing time is feasible. The significance of the results is that the tedious task of manually counting a large number of particles can be eliminated while still providing the scientist with accurate results.

Announcement: Community Preventive Services Task Force Recommendation for Built Environment Interventions to Increase Physical Activity.

PubMed

2017-05-05

The Community Preventive Services Task Force recently posted new information on its website: "Physical Activity: Built Environment Approaches Combining Transportation System Interventions with Land Use and Environmental Design." This information is available at https://www.thecommunityguide.org/findings/physical-activity-built-environment-approaches.

Balance training with multi-task exercises improves fall-related self-efficacy, gait, balance performance and physical function in older adults with osteoporosis: a randomized controlled trial.

PubMed

Halvarsson, Alexandra; Franzén, Erika; Ståhle, Agneta

2015-04-01

To evaluate the effects of a balance training program including dual- and multi-task exercises on fall-related self-efficacy, fear of falling, gait and balance performance, and physical function in older adults with osteoporosis with an increased risk of falling and to evaluate whether additional physical activity would further improve the effects. Randomized controlled trial, including three groups: two intervention groups (Training, or Training+Physical activity) and one Control group, with a 12-week follow-up. Stockholm County, Sweden. Ninety-six older adults, aged 66-87, with verified osteoporosis. A specific and progressive balance training program including dual- and multi-task three times/week for 12 weeks, and physical activity for 30 minutes, three times/week. Fall-related self-efficacy (Falls Efficacy Scale-International), fear of falling (single-item question - 'In general, are you afraid of falling?'), gait speed with and without a cognitive dual-task at preferred pace and fast walking (GAITRite®), balance performance tests (one-leg stance, and modified figure of eight), and physical function (Late-Life Function and Disability Instrument). Both intervention groups significantly improved their fall-related self-efficacy as compared to the controls (p ≤ 0.034, 4 points) and improved their balance performance. Significant differences over time and between groups in favour of the intervention groups were found for walking speed with a dual-task (p=0.003), at fast walking speed (p=0.008), and for advanced lower extremity physical function (p=0.034). This balance training program, including dual- and multi-task, improves fall-related self-efficacy, gait speed, balance performance, and physical function in older adults with osteoporosis. © The Author(s) 2014.

Martinus Veltman, the Electroweak Theory, and Elementary Particle Physics

Science.gov Websites

Particle Physics Resources with Additional Information Martinus Veltman Courtesy University of Michigan Martinus J.G. Veltman, the John D. MacArthur Professor Emeritus of Physics at the University of Michigan , was awarded the 1999 Nobel Prize in physics "for elucidating the quantum structure of electroweak

Lagrangian particles with mixing. I. Simulating scalar transport

NASA Astrophysics Data System (ADS)

Klimenko, A. Y.

2009-06-01

The physical similarity and mathematical equivalence of continuous diffusion and particle random walk forms one of the cornerstones of modern physics and the theory of stochastic processes. The randomly walking particles do not need to posses any properties other than location in physical space. However, particles used in many models dealing with simulating turbulent transport and turbulent combustion do posses a set of scalar properties and mixing between particle properties is performed to reflect the dissipative nature of the diffusion processes. We show that the continuous scalar transport and diffusion can be accurately specified by means of localized mixing between randomly walking Lagrangian particles with scalar properties and assess errors associated with this scheme. Particles with scalar properties and localized mixing represent an alternative formulation for the process, which is selected to represent the continuous diffusion. Simulating diffusion by Lagrangian particles with mixing involves three main competing requirements: minimizing stochastic uncertainty, minimizing bias introduced by numerical diffusion, and preserving independence of particles. These requirements are analyzed for two limited cases of mixing between two particles and mixing between a large number of particles. The problem of possible dependences between particles is most complicated. This problem is analyzed using a coupled chain of equations that has similarities with Bogolubov-Born-Green-Kirkwood-Yvon chain in statistical physics. Dependences between particles can be significant in close proximity of the particles resulting in a reduced rate of mixing. This work develops further ideas introduced in the previously published letter [Phys. Fluids 19, 031702 (2007)]. Paper I of this work is followed by Paper II [Phys. Fluids 19, 065102 (2009)] where modeling of turbulent reacting flows by Lagrangian particles with localized mixing is specifically considered.

Relationship between sports experience and executive function in 6-12-year-old children: independence from physical fitness and moderation by gender.

PubMed

Ishihara, Toru; Sugasawa, Shigemi; Matsuda, Yusuke; Mizuno, Masao

2018-05-01

The purpose of this study was to evaluate the relationship between sports experience (i.e., tennis experience) and executive function in children while controlling for physical activity and physical fitness. Sixty-eight participants (6-12 years old, 34 males and 34 females) were enrolled in regular tennis lessons (mean = 2.4 years, range = 0.1-7.3 years) prior to the study. Executive functions, including inhibitory control (the Stroop Color-Word Test), working memory (the 2-back Task), and cognitive flexibility (the Local-global Task) were evaluated. Participants' levels of daily physical activity, ranging from moderate to vigorous, were evaluated using triaxial accelerometers. The total score for physical fitness was assessed using the Tennis Field Test. Hierarchical multiple regression analyses revealed interaction effects between gender and tennis experience on participants' reaction time (RT) on the switch cost of the Local-global Task after controlling for age, BMI, gender, physical activity, physical fitness, and tennis experience. Longer tennis experience was associated with shorter switch cost in males but not in females. Higher scores on physical fitness were positively associated with lower interference scores on the Stroop Color-Word Test, RT on the 2-back Task, and RT in the switching condition of the Local-global Task, after controlling for age, BMI, gender, and physical activity. In conclusion, all three foundational components of executive function (i.e., inhibitory control, working memory, and cognitive flexibility) were more strongly related to physical fitness than to physical activity in males and females, whereas greater cognitive flexibility was related to tennis experience only in the males. © 2017 John Wiley & Sons Ltd.

Qualitative and quantitative composition of microplastics particles during the expeditionary measurement program in the South-Eastern Baltic Sea

NASA Astrophysics Data System (ADS)

Esiukova, Elena; Bagaeva, Margarita; Chubarenko, Natalia

2016-04-01

According to the tasks of the Russian Science Foundation project "Physical and dynamical properties of marine microplastics particles and their transport in a basin with vertical and horizontal salinity gradient on the example of the Baltic Sea" number 15-17-10020, a comprehensive expeditionary program of measurements in the South-Eastern Baltic started. The project is aimed at finding solutions for a number of problems caused by superfluous plastic pollution in the World Ocean and, in particular, in the Baltic Sea. This pollution has been accumulating for years and just recently it has become obvious that only multidisciplinary approach (geographical, biological, chemical, etc.) to the issues related to the processes of transformation of properties and propagation of plastic particles will allow the study of physical aspects of the problem. During the first stage of the study samples should be selected from the water surface, water column at various horizons, bottom sediments in the Baltic Sea, from different areas at the beaches - in order to further examine the qualitative and quantitative composition of microplastic particles in different seasons for different hydrophysical situations. Reconnaissance survey was begun to choose the fields for research close to point and distributed sources of microplastics. Preference is given to those beaches that are exposed to maximum anthropogenic pollution: areas around the town of Baltiysk, the northern part of the Vistula Spit (near the settlement of Kosa), and the Sambia peninsula coast (settlements of Yantarny, Donskoye, Primorye, Kulikovo, towns of Svetlogorsk, Pionersky, Zelenogradsk). Locations for experimental sites were found in order to assess time for formation of microplastics (Vistula Spit, Kosa settlement). In June-November, 2015 there were 5 expeditions in the waters of the South-Eastern Baltic, 7 expeditions along the coast line of the Baltic Sea (in Kaliningrad Oblast), and 5 expeditions to the Vistula lagoon to take samples and collect experimental materials. Altogether, 61 samples were taken from the surface of the beaches, water and bottom sediments in the Baltic Sea. The primary examination of those samples revealed abundant microplastic particles of the required sizes (0.5 - 5 mm) shaped as pellet of various configurations, spheres, threads, fragments, as well as particles of amber and small fractions of paraffin. The research is supported by the Russian Science Foundation grant number 15-17-10020.

Pions to Quarks

NASA Astrophysics Data System (ADS)

Brown, Laurie Mark; Dresden, Max; Hoddeson, Lillian

2009-01-01

Part I. Introduction; 1. Pions to quarks: particle physics in the 1950s Laurie M Brown, Max Dresden and Lillian Hoddeson; 2. Particle physics in the early 1950s Chen Ning Yang; 3. An historian's interest in particle physics J. L. Heilbron; Part II. Particle discoveries in cosmic rays; 4. Cosmic-ray cloud-chamber contributions to the discovery of the strange particles in the decade 1947-1957 George D. Rochester; 5. Cosmic-ray work with emulsions in the 1940s and 1950s Donald H. Perkins; Part III. High-energy nuclear physics; Learning about nucleon resonances with pion photoproduction Robert L. Walker; 7. A personal view of nucleon structure as revealed by electron scattering Robert Hofstadter; 8. Comments on electromagnetic form factors of the nucleon Robert G. Sachs and Kameshwar C. Wali; Part IV. The new laboratory; 9. The making of an accelerator physicist Matthew Sands; 10. Accelerator design and construction in the 1950s John P. Blewett; 11. Early history of the Cosmotron and AGS Ernest D. Courant; 12. Panel on accelerators and detectors in the 1950s Lawrence W. Jones, Luis W. Alvarez, Ugo Amaldi, Robert Hofstadter, Donald W. Kerst, Robert R. Wilson; 13. Accelerators and the Midwestern Universities Research Association in the 1950s Donald W. Kerst; 14. Bubbles, sparks and the postwar laboratory Peter Galison; 15. Development of the discharge (spark) chamber in Japan in the 1950s Shuji Fukui; 16. Early work at the Bevatron: a personal account Gerson Goldhaber; 17. The discovery of the antiproton Owen Chamberlain; 18. On the antiproton discovery Oreste Piccioni; Part V. The Strange Particles; 19. The hydrogen bubble chamber and the strange resonances Luis W. Alvarez; 20. A particular view of particle physics in the fifties Jack Steinberger; 21. Strange particles William Chinowsky; 22. Strange particles: production by Cosmotron beams as observed in diffusion cloud chambers William B. Fowler; 23. From the 1940s into the 1950s Abraham Pais; Part VI. Detection of the neutrino Frederick Reines; 25. Recollections on the establishment of the weak-interaction notion Bruno M. Pontecorvo; 26. Symmetry and conservation laws in particle physics in the fifties Louis Michel; 27. A connection between the strong and weak interactions Sam B. Treiman; Part VII. Weak interactions and parity nonconservation; 29. The nondiscovery of parity nonconservation Allan Franklin; 30. K-meson decays and parity violation Richard H. Dalitz; 31. An Experimentalist's Perspective Val L. Fitch; 32. The early experiments leading to the V - A interaction Valentine L. Telegdi; 33. Midcentury adventures in particles physics E. C. G. Sudarshan; Part VIII. The particle physics community; 34. The postwar political economy of high-energy physics Robert Seidel; 35. The history of CERN during the early 1950s Edoardo Amaldi; 36. Arguments pro and contra the European laboratory in the participating countries Armin Hermann; 37. Physics and excellences of the life it brings Abdus Salam; 38. Social aspects of Japanese particle physics in the 1950s Michiji Konuma; Part IX. Theories of hadrons; 39. The early S-matrix theory and its propagation (1942-1952) Helmut Rechenberg; 40. From field theory to phenomenology: the history of dispersion relations Andy Pickering; 41. Particles as S-matrix poles: hadron democracy Geoffrey F. Chew; 42. The general theory of quantised fields in the 1950s Arthur S. Wrightman; 43. The classification and structure of hadrons Yuval Ne'eman; 44. Gauge principle, vector-meson dominance and spontaneous symmetry breaking Yoichiro Nambu; Part X. Personal overviews; 45. Scientific impact of the first decade of the Rochester conferences (1950-1960) Robert E. Marshak; 46. Some reflections on the history of particle physics in the 1950s Silvan S. Schweber; 47. Progress in elementary particle theory 1950-1964 Murray Gell-Mann.

Plato's Ideas and the Theories of Modern Particle Physics: Amazing Parallels

NASA Astrophysics Data System (ADS)

Machleidt, Ruprecht

2006-05-01

It is generally known that the question, ``What are the most elementary particles that all matter is made from?'', was already posed in the antiquity. The Greek natural philosophers Leucippus and Democritus were the first to suggest that all matter was made from atoms. Therefore, most people perceive them as the ancient fathers of elementary particle physics. However, this perception is wrong. Modern particle physics is not just a simple atomism. The characteristic point of modern particle theory is that it is concerned with the symmetries underlying the particles we discover in experiment. More than 2000 years ago, a similar idea was already advanced by the Greek philosopher Plato in his dialogue Timaeus: Geometric symmetries generate the atoms from just a few even more elementary items. Plato's vision is amazingly close to the ideas of modern particle theory. This fact, which is unfortunately little known, has been pointed out repeatedly by Werner Heisenberg.

Manipulation of particles by weak forces

NASA Technical Reports Server (NTRS)

Adler, M. S.; Savkar, S. D.; Summerhayes, H. R.

1972-01-01

Quantitative relations between various force fields and their effects on the motion of particles of various sizes and physical characteristics were studied. The forces considered were those derived from light, heat, microwaves, electric interactions, magnetic interactions, particulate interactions, and sound. A physical understanding is given of the forces considered as well as formulae which express how the size of the force depends on the physical and electrical properties of the particle. The drift velocity in a viscous fluid is evaluated as a function of initial acceleration and the effects of thermal random motion are considered. A means of selectively sorting or moving particles by choosing a force system and/or environment such that the particle of interest reacts uniquely was developed. The forces considered and a demonstration of how the initial acceleration, drift velocity, and ultimate particle density distribution is affected by particle, input, and environmental parameters are tabulated.

Quarks, Leptons, and Bosons: A Particle Physics Primer.

ERIC Educational Resources Information Center

Wagoner, Robert; Goldsmith, Donald

1983-01-01

Presented is a non-technical introduction to particle physics. The material is adapted from chapter 3 of "Cosmic Horizons," (by Robert Wagoner and Don Goldsmith), a lay-person's introduction to cosmology. Among the topics considered are elementary particles, forces and motion, and higher level structures. (JN)

Challenges in Physical Characterization of Dim Space Objects: What Can We Learn from NEOs

NASA Astrophysics Data System (ADS)

Reddy, V.; Sanchez, J.; Thirouin, A.; Rivera-Valentin, E.; Ryan, W.; Ryan, E.; Mokovitz, N.; Tegler, S.

2016-09-01

Physical characterization of dim space objects in cis-lunar space can be a challenging task. Of particular interest to both natural and artificial space object behavior scientists are the properties beyond orbital parameters that can uniquely identify them. These properties include rotational state, size, shape, density and composition. A wide range of observational and non-observational factors affect our ability to characterize dim objects in cis-lunar space. For example, phase angle (angle between Sun-Target-Observer), temperature, rotational variations, temperature, and particle size (for natural dim objects). Over the last two decades, space object behavior scientists studying natural dim objects have attempted to quantify and correct for a majority of these factors to enhance our situational awareness. These efforts have been primarily focused on developing laboratory spectral calibrations in a space-like environment. Calibrations developed correcting spectral observations of natural dim objects could be applied to characterizing artificial objects, as the underlying physics is the same. The paper will summarize our current understanding of these observational and non-observational factors and present a case study showcasing the state of the art in characterization of natural dim objects.

Big Data in HEP: A comprehensive use case study

DOE PAGES

Gutsche, Oliver; Cremonesi, Matteo; Elmer, Peter; ...

2017-11-23

Experimental Particle Physics has been at the forefront of analyzing the worlds largest datasets for decades. The HEP community was the first to develop suitable software and computing tools for this task. In recent times, new toolkits and systems collectively called Big Data technologies have emerged to support the analysis of Petabyte and Exabyte datasets in industry. While the principles of data analysis in HEP have not changed (filtering and transforming experiment-specific data formats), these new technologies use different approaches and promise a fresh look at analysis of very large datasets and could potentially reduce the time-to-physics with increased interactivity.more » In this talk, we present an active LHC Run 2 analysis, searching for dark matter with the CMS detector, as a testbed for Big Data technologies. We directly compare the traditional NTuple-based analysis with an equivalent analysis using Apache Spark on the Hadoop ecosystem and beyond. In both cases, we start the analysis with the official experiment data formats and produce publication physics plots. Lastly, we will discuss advantages and disadvantages of each approach and give an outlook on further studies needed.« less

Big Data in HEP: A comprehensive use case study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gutsche, Oliver; Cremonesi, Matteo; Elmer, Peter

Experimental Particle Physics has been at the forefront of analyzing the worlds largest datasets for decades. The HEP community was the first to develop suitable software and computing tools for this task. In recent times, new toolkits and systems collectively called Big Data technologies have emerged to support the analysis of Petabyte and Exabyte datasets in industry. While the principles of data analysis in HEP have not changed (filtering and transforming experiment-specific data formats), these new technologies use different approaches and promise a fresh look at analysis of very large datasets and could potentially reduce the time-to-physics with increased interactivity.more » In this talk, we present an active LHC Run 2 analysis, searching for dark matter with the CMS detector, as a testbed for Big Data technologies. We directly compare the traditional NTuple-based analysis with an equivalent analysis using Apache Spark on the Hadoop ecosystem and beyond. In both cases, we start the analysis with the official experiment data formats and produce publication physics plots. Lastly, we will discuss advantages and disadvantages of each approach and give an outlook on further studies needed.« less

Asymptotic orderings and approximations of the Master kinetic equation for large hard spheres systems

NASA Astrophysics Data System (ADS)

Tessarotto, Massimo; Asci, Claudio

2017-05-01

In this paper the problem is posed of determining the physically-meaningful asymptotic orderings holding for the statistical description of a large N-body system of hard spheres, i.e., formed by N ≡1/ε ≫ 1 particles, which are allowed to undergo instantaneous and purely elastic unary, binary or multiple collisions. Starting point is the axiomatic treatment recently developed [Tessarotto et al., 2013-2016] and the related discovery of an exact kinetic equation realized by Master equation which advances in time the 1-body probability density function (PDF) for such a system. As shown in the paper the task involves introducing appropriate asymptotic orderings in terms of ε for all the physically-relevant parameters. The goal is that of identifying the relevant physically-meaningful asymptotic approximations applicable for the Master kinetic equation, together with their possible relationships with the Boltzmann and Enskog kinetic equations, and holding in appropriate asymptotic regimes. These correspond either to dilute or dense systems and are formed either by small-size or finite-size identical hard spheres, the distinction between the various cases depending on suitable asymptotic orderings in terms of ε.

Higgs Particle: The Origin of Mass

NASA Astrophysics Data System (ADS)

Okada, Yasuhiro

2007-11-01

The Higgs particle is a new elementary particle predicted in the Standard Model of the elementary particle physics. It plays a special role in the theory of mass generation of quarks, leptons, and gauge bosons. In this article, theoretical issues on the Higgs mechanism are first discussed, and then experimental prospects on the Higgs particle study at the future collider experiments, LHC and ILC, are reviewed. The Higgs coupling determination is an essential step to establish the mass generation mechanism, which could lead to a deeper understanding of particle physics.

Intuitive physics ability in systemizers relies on differential use of the internalizing system and long-term spatial representations.

PubMed

Riekki, Tapani; Salmi, Juha; Svedholm-Häkkinen, Annika M; Lindeman, Marjaana

2018-01-31

According to the Empathizing-Systemizing theory (E-S Theory), individual differences in how people understand the physical world (systemizing) and the social world (empathizing), are two continuums in the general population with several implications, from vocational interests to skills in the social and physical domains. The underlying mechanisms of intuitive physics performance among individuals with strong systemizing and weak empathizing (systemizers) are, however, unknown. Our results affirm higher intuitive physics skills in healthy adult systemizers (N=36), and further reveal the brain mechanisms that are characteristic for those individuals in carrying out such tasks. When the participants performed intuitive physics tasks during functional magnetic resonance imaging, combined higher systemizing and lower empathizing was associated with stronger activations in parts of the default mode network (DMN, cuneus and posterior cingulate gyrus), middle occipital gyrus, and parahippocampal region. The posterior cingulate gyrus and parahippocampal gyrus were specifically associated with systemizing "brain type" even after controlling for task performance, while especially in the parietal cortex, the activation changes were simply explained by higher task performance. We therefore suggest that utilization of DMN-parahippocampal complex, suggested to play a role in internalizing and activating long-term spatial memory representations, is the factor that distinguishes systemizers from empathizers with the opposite "brain type" in intuitive physics tasks. Copyright © 2017 Elsevier Ltd. All rights reserved.

Gender, BMI, Values, and Learning in Physical Education: A Study on Chinese Middle Schoolers

ERIC Educational Resources Information Center

Ding, Haiyong; Sun, Haichun; Chen, Ang

2011-01-01

Students' different perceptions of task values influence their learning experience and achievement in physical education. Framed using the subjective task value construct, this study was conducted to determine the extent to which male and female Chinese middle schoolers with different body sizes differed in their perception of the task values. A…

The Impact of Learning Task Design on Students' Situational Interest in Physical Education

ERIC Educational Resources Information Center

Roure, Cédric; Pasco, Denis

2018-01-01

Purpose: Based on the framework of interest, studies have shown that teachers can enhance students' situational interest (SI) by manipulating the components of learning tasks. The purpose of this study was to examine the impact of learning task design on students' SI in physical education (PE). Method: The participants were 167 secondary school…

Solving Developmental Tasks in Adolescents with a Chronic Physical Illness or Physical/Sensory Disability: A Meta-Analysis

ERIC Educational Resources Information Center

Pinquart, Martin; Pfeiffer, Jens P.

2015-01-01

Chronic illnesses and disabilities may impair the attainment of age-typical developmental tasks, such as forming relationships with peers and gaining autonomy. Based on a systematic search in electronic databases and cross-referencing, 447 quantitative empirical studies were included which compared the attainment of developmental tasks of…

Review of heavy charged particle transport in MCNP6.2

NASA Astrophysics Data System (ADS)

Zieb, K.; Hughes, H. G.; James, M. R.; Xu, X. G.

2018-04-01

The release of version 6.2 of the MCNP6 radiation transport code is imminent. To complement the newest release, a summary of the heavy charged particle physics models used in the 1 MeV to 1 GeV energy regime is presented. Several changes have been introduced into the charged particle physics models since the merger of the MCNP5 and MCNPX codes into MCNP6. This paper discusses the default models used in MCNP6 for continuous energy loss, energy straggling, and angular scattering of heavy charged particles. Explanations of the physics models' theories are included as well.

Review of Heavy Charged Particle Transport in MCNP6.2

DOE PAGES

Zieb, Kristofer James Ekhart; Hughes, Henry Grady III; Xu, X. George; ...

2018-01-05

The release of version 6.2 of the MCNP6 radiation transport code is imminent. To complement the newest release, a summary of the heavy charged particle physics models used in the 1 MeV to 1 GeV energy regime is presented. Several changes have been introduced into the charged particle physics models since the merger of the MCNP5 and MCNPX codes into MCNP6. Here, this article discusses the default models used in MCNP6 for continuous energy loss, energy straggling, and angular scattering of heavy charged particles. Explanations of the physics models’ theories are included as well.

Development of a Physical Employment Testing Battery for 12B Combat Engineers

DTIC Science & Technology

2015-12-10

30 1.6 Summary of Physical Demands of Tasks 31 1.7 Tasks with Sex Differences 32 Study 2: Criterion Task Development and Reliability 2.1 Factors...adjustments for age and sex , not only biasing for/against certain groups, but making it potentially legally indefensible if used as a screening tool...male 128 Soldiers, female Soldiers from other MOSs also performed the tasks in order to include physiological responses from both sexes . These data

The benefits of endurance exercise and Tai Chi Chuan for the task-switching aspect of executive function in older adults: an ERP study.

PubMed

Fong, Dong-Yang; Chi, Li-Kang; Li, Fuzhong; Chang, Yu-Kai

2014-01-01

This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels.

The benefits of endurance exercise and Tai Chi Chuan for the task-switching aspect of executive function in older adults: an ERP study

PubMed Central

Fong, Dong-Yang; Chi, Li-Kang; Li, Fuzhong; Chang, Yu-Kai

2014-01-01

This study was designed to determine the relationship between physical activity and the task-switching aspect of executive function by investigating the modulating roles of age, modality of physical activity, and type of cognitive function using behavioral and event-related potential (ERP) assessments. Sixty-four participants were assigned to one of four groups based on age and history of physical activity: older adults performing endurance exercise (OEE), older adults practicing Tai Chi Chuan (OTC), older adults with a sedentary lifestyle (OSL), and young adults (YA). Study participants completed a task-switching task under homogeneous and heterogeneous conditions while ERPs were recorded. The results revealed that YA had shortest reaction times compared with the three older adults groups, with OSL exhibiting the longest reaction time. YA also exhibited shorter P3 latency than OSL. No differences were observed in P3 amplitude between YA, OEE, and OTC; however, all three groups had significantly larger P3 amplitude compared with OSL in both task conditions. In conclusion, age and participation in physical activity influence the relationship between physical activity and task-switching, and a positive relationship was observed regardless of the modality of physical activity and type of cognitive function. Our ERP findings support the model of the scaffolding theory of aging and cognition (STAC) and suggest that regular participation in endurance exercise and Tai Chi Chuan may have equivalent beneficial effects on cognition at the behavioral and neuroelectric levels. PMID:25389403

AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training.

PubMed

Harkness, Beth A; Allison, Jerry D; Clements, Jessica B; Coffey, Charles W; Fahey, Frederic H; Gress, Dustin A; Kinahan, Paul E; Nickoloff, Edward L; Mawlawi, Osama R; MacDougall, Robert D; Pizzutiello, Robert J

2015-09-08

The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear  medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics  Training. The mission of this task force was to assemble a representative group of stakeholders to:• Estimate the demand for board-certified nuclear medicine physicists in the next 5-10 years,• Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, and• Identify approaches that may be considered to facilitate the training of nuclear medicine physicists.As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face-to-face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission.

AAPM/SNMMI Joint Task Force: report on the current state of nuclear medicine physics training

PubMed Central

Allison, Jerry D.; Clements, Jessica B.; Coffey, Charles W.; Fahey, Frederic H.; Gress, Dustin A.; Kinahan, Paul E.; Nickoloff, Edward L.; Mawlawi, Osama R.; MacDougall, Robert D.; Pizzuitello, Robert J.

2015-01-01

The American Association of Physicists in Medicine (AAPM) and the Society of Nuclear Medicine and Molecular Imaging (SNMMI) recognized the need for a review of the current state of nuclear medicine physics training and the need to explore pathways for improving nuclear medicine physics training opportunities. For these reasons, the two organizations formed a joint AAPM/SNMMI Ad Hoc Task Force on Nuclear Medicine Physics Training. The mission of this task force was to assemble a representative group of stakeholders to: Estimate the demand for board‐certified nuclear medicine physicists in the next 5–10 years,Identify the critical issues related to supplying an adequate number of physicists who have received the appropriate level of training in nuclear medicine physics, andIdentify approaches that may be considered to facilitate the training of nuclear medicine physicists. As a result, a task force was appointed and chaired by an active member of both organizations that included representation from the AAPM, SNMMI, the American Board of Radiology (ABR), the American Board of Science in Nuclear Medicine (ABSNM), and the Commission for the Accreditation of Medical Physics Educational Programs (CAMPEP). The Task Force first met at the AAPM Annual Meeting in Charlotte in July 2012 and has met regularly face‐to‐face, online, and by conference calls. This manuscript reports the findings of the Task Force, as well as recommendations to achieve the stated mission. PACS number: 01.40.G‐ PMID:26699325

Physics in ordered and disordered colloidal matter composed of poly(N-isopropylacrylamide) microgel particles.

PubMed

Yunker, Peter J; Chen, Ke; Gratale, Matthew D; Lohr, Matthew A; Still, Tim; Yodh, A G

2014-05-01

This review collects and describes experiments that employ colloidal suspensions to probe physics in ordered and disordered solids and related complex fluids. The unifying feature of this body of work is its clever usage of poly(N-isopropylacrylamide) (PNIPAM) microgel particles. These temperature-sensitive colloidal particles provide experimenters with a 'knob' for in situ control of particle size, particle interaction and particle packing fraction that, in turn, influence the structural and dynamical behavior of the complex fluids and solids. A brief summary of PNIPAM particle synthesis and properties is given, followed by a synopsis of current activity in the field. The latter discussion describes a variety of soft matter investigations including those that explore formation and melting of crystals and clusters, and those that probe structure, rearrangement and rheology of disordered (jammed/glassy) and partially ordered matter. The review, therefore, provides a snapshot of a broad range of physics phenomenology which benefits from the unique properties of responsive microgel particles.

Preparing for Combat Readiness for the Fight: Physical Performance Profile of Female U.S. Marines.

PubMed

Kelly, Karen R; Jameson, Jason T

2016-03-01

Females have been restricted from serving in direct combat arms' positions for decades. One reason for the exclusion derives from the perceived physical demands of these positions. As a result, many current efforts are directed toward defining the physical demands of combat arms' positions. The purpose of this study was to develop a physical performance and body composition profile of females who could overcome the physical demands of combat tasks that rely primarily on upper body strength. This study is based on an analysis of archival data from 2 separate samples of active-duty female Marines (n = 802), who had been recruited to participate in heavy lifting tasks. These tasks included lifting a heavy machine gun (HMG) lift (cohort 1, n = 423) and Clean and Press lifts (29.5-52.3 kg) (cohort 2, n = 379). To develop the physical performance profile, data from annual physical fitness tests were collected, which included run times, ammunition can lift, 804. Seven-meter (880-yard) movement to contact, and the maneuver under fire. In cohort 1, 65 females (∼15%; n = 423 females) successfully completed HMG; in cohort 2, 33 females (∼9%; n = 379 females) successfully completed another strength task, a Clean and Press of 52.3 kg. In both samples, female Marines who were successful on these tasks also outperformed their unsuccessful counterparts on the annual physical fitness tests. In addition, larger females typically outperformed their smaller counterparts. Females seeking assignment to closed combat arms' positions would thus be well served by targeting upper body strength, while maintaining overall physical fitness.

Occurrence and Characteristics of {sup 18}O-exchange Reactions Catalyzed By Sodium- and Potassium-dependent Adenosine Triphosphatases

DOE R&D Accomplishments Database

Dahms, A. S.; Boyer, P. D.

This discusses the following topics in High Energy Physics: The Particle Zoo; The Strong and the Weak; The Particle Explosion; Deep Inside the Nucleon; The Search for Unity; Physics in Collision; The Standard Model; Particles and the Cosmos; and Practical Benefits.

Is there an agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists’ job descriptions?

PubMed Central

2016-01-01

Purpose: To determine the agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists’ job descriptions. Methods: The main tasks of physical therapists were classified, and university courses related to the main tasks were also classified. Frequency analysis was used to determine the proportions of credits for the classified courses out of the total credits of major subjects, exam items related to the classified courses out of the total number of exam items, and universities that offer courses related to the Korean physical therapist licensing examination among the surveyed universities. Results: The proportions of credits for clinical decision making and physical therapy diagnosis-related courses out of the total number credits for major subjects at universities were relatively low (2.06% and 2.58%, respectively). Although the main tasks of physical therapists are related to diagnosis and evaluation, the proportion of physiotherapy intervention-related items (35%) was higher than that of examination and evaluation-related items (25%) on the Korean physical therapist licensing examination. The percentages of universities that offer physical therapy diagnosis and clinical decision making-related courses were 58.62% and 68.97%, respectively. Conclusion: Both the proportion of physiotherapy diagnosis and evaluation-related items on the Korean physical therapist licensing examination, and the number of subjects related to clinical decision making and physical therapy diagnosis in the physical therapy curriculum, should be increased to ensure that the examination items and physical therapy curriculum reflect the practical tasks of physical therapists. PMID:26767720

Is there an agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists' job descriptions?

PubMed

Kang, Min-Hyeok; Kwon, Oh-Yun; Kim, Yong-Wook; Kim, Ji-Won; Kim, Tae-Ho; Oh, Tae-Young; Weon, Jong-Hyuk; Lee, Tae-Sik; Oh, Jae-Seop

2016-01-01

To determine the agreement among the items of the Korean physical therapist licensing examination, learning objectives of class subjects, and physical therapists' job descriptions. The main tasks of physical therapists were classified, and university courses related to the main tasks were also classified. Frequency analysis was used to determine the proportions of credits for the classified courses out of the total credits of major subjects, exam items related to the classified courses out of the total number of exam items, and universities that offer courses related to the Korean physical therapist licensing examination among the surveyed universities. The proportions of credits for clinical decision making and physical therapy diagnosis-related courses out of the total number credits for major subjects at universities were relatively low (2.06% and 2.58%, respectively). Although the main tasks of physical therapists are related to diagnosis and evaluation, the proportion of physiotherapy intervention-related items (35%) was higher than that of examination and evaluation-related items (25%) on the Korean physical therapist licensing examination. The percentages of universities that offer physical therapy diagnosis and clinical decision making-related courses were 58.62% and 68.97%, respectively. Both the proportion of physiotherapy diagnosis and evaluation-related items on the Korean physical therapist licensing examination, and the number of subjects related to clinical decision making and physical therapy diagnosis in the physical therapy curriculum, should be increased to ensure that the examination items and physical therapy curriculum reflect the practical tasks of physical therapists.

Highly stabilized, polymer-lipid membranes prepared on silica microparticles as stationary phases for capillary chromatography

PubMed Central

Gallagher, Elyssia S.; Adem, Seid M.; Baker, Christopher A.; Ratnayaka, Saliya N.; Jones, Ian W.; Hall, Henry K.; Saavedra, S. Scott; Aspinwall, Craig A.

2015-01-01

The ability to rapidly screen complex libraries of pharmacological modulators is paramount to modern drug discovery efforts. This task is particularly challenging for agents that interact with lipid bilayers or membrane proteins due to the limited chemical, physical, and temporal stability of conventional lipid-based chromatographic stationary phases. Here, we describe the preparation and characterization of a novel stationary phase material composed of highly stable, polymeric-phospholipid bilayers self-assembled onto silica microparticles. Polymer lipid membranes were prepared by photochemical or redox initiated polymerization of 1,2-bis[10-(2′,4′-hexadieoyloxy)decanoyl]-sn-glycero-2-phosphocholine (bis-SorbPC), a synthetic, polymerizable lipid. The resulting polymerized bis-SorbPC (poly(bis-SorbPC)) stationary phases exhibited enhanced stability compared to particles coated with 1,2-dioleoyl-sn-glycero-phosphocholine (unpolymerized) phospholipid bilayers when exposed to chemical (50mM triton X-100 or 50% acetonitrile) and physical (15 min sonication) insults after 30 days of storage. Further, poly(bis-SorbPC)-coated particles survived slurry packing into fused silica capillaries, compared to unpolymerized lipid membranes, where the lipid bilayer was destroyed during packing. Frontal chromatographic analyses of the lipophilic small molecules acetylsalicylic acid, benzoic acid, and salicylic acid showed > 44% increase in retention times (P < 0.0001) for all analytes on poly(bis-SorbPC)-functionalized stationary phase compared to bare silica microspheres, suggesting a lipophilic retention mechanism. Phospholipid membrane-functionalized stationary phases that withstand the chemical and physical rigors of capillary LC conditions can substantially increase the efficacy of lipid membrane affinity chromatography, and represents a key advance towards the development of robust membrane protein-functionalized chromatographic stationary phases. PMID:25670414

Accelerating population balance-Monte Carlo simulation for coagulation dynamics from the Markov jump model, stochastic algorithm and GPU parallel computing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Zuwei; Zhao, Haibo, E-mail: klinsmannzhb@163.com; Zheng, Chuguang

2015-01-15

This paper proposes a comprehensive framework for accelerating population balance-Monte Carlo (PBMC) simulation of particle coagulation dynamics. By combining Markov jump model, weighted majorant kernel and GPU (graphics processing unit) parallel computing, a significant gain in computational efficiency is achieved. The Markov jump model constructs a coagulation-rule matrix of differentially-weighted simulation particles, so as to capture the time evolution of particle size distribution with low statistical noise over the full size range and as far as possible to reduce the number of time loopings. Here three coagulation rules are highlighted and it is found that constructing appropriate coagulation rule providesmore » a route to attain the compromise between accuracy and cost of PBMC methods. Further, in order to avoid double looping over all simulation particles when considering the two-particle events (typically, particle coagulation), the weighted majorant kernel is introduced to estimate the maximum coagulation rates being used for acceptance–rejection processes by single-looping over all particles, and meanwhile the mean time-step of coagulation event is estimated by summing the coagulation kernels of rejected and accepted particle pairs. The computational load of these fast differentially-weighted PBMC simulations (based on the Markov jump model) is reduced greatly to be proportional to the number of simulation particles in a zero-dimensional system (single cell). Finally, for a spatially inhomogeneous multi-dimensional (multi-cell) simulation, the proposed fast PBMC is performed in each cell, and multiple cells are parallel processed by multi-cores on a GPU that can implement the massively threaded data-parallel tasks to obtain remarkable speedup ratio (comparing with CPU computation, the speedup ratio of GPU parallel computing is as high as 200 in a case of 100 cells with 10 000 simulation particles per cell). These accelerating approaches of PBMC are demonstrated in a physically realistic Brownian coagulation case. The computational accuracy is validated with benchmark solution of discrete-sectional method. The simulation results show that the comprehensive approach can attain very favorable improvement in cost without sacrificing computational accuracy.« less

Numerical simulation of disperse particle flows on a graphics processing unit

NASA Astrophysics Data System (ADS)

Sierakowski, Adam J.

In both nature and technology, we commonly encounter solid particles being carried within fluid flows, from dust storms to sediment erosion and from food processing to energy generation. The motion of uncountably many particles in highly dynamic flow environments characterizes the tremendous complexity of such phenomena. While methods exist for the full-scale numerical simulation of such systems, current computational capabilities require the simplification of the numerical task with significant approximation using closure models widely recognized as insufficient. There is therefore a fundamental need for the investigation of the underlying physical processes governing these disperse particle flows. In the present work, we develop a new tool based on the Physalis method for the first-principles numerical simulation of thousands of particles (a small fraction of an entire disperse particle flow system) in order to assist in the search for new reduced-order closure models. We discuss numerous enhancements to the efficiency and stability of the Physalis method, which introduces the influence of spherical particles to a fixed-grid incompressible Navier-Stokes flow solver using a local analytic solution to the flow equations. Our first-principles investigation demands the modeling of unresolved length and time scales associated with particle collisions. We introduce a collision model alongside Physalis, incorporating lubrication effects and proposing a new nonlinearly damped Hertzian contact model. By reproducing experimental studies from the literature, we document extensive validation of the methods. We discuss the implementation of our methods for massively parallel computation using a graphics processing unit (GPU). We combine Eulerian grid-based algorithms with Lagrangian particle-based algorithms to achieve computational throughput up to 90 times faster than the legacy implementation of Physalis for a single central processing unit. By avoiding all data communication between the GPU and the host system during the simulation, we utilize with great efficacy the GPU hardware with which many high performance computing systems are currently equipped. We conclude by looking forward to the future of Physalis with multi-GPU parallelization in order to perform resolved disperse flow simulations of more than 100,000 particles and further advance the development of reduced-order closure models.

A Hybrid Physics-Based Data-Driven Approach for Point-Particle Force Modeling

NASA Astrophysics Data System (ADS)

Moore, Chandler; Akiki, Georges; Balachandar, S.

2017-11-01

This study improves upon the physics-based pairwise interaction extended point-particle (PIEP) model. The PIEP model leverages a physical framework to predict fluid mediated interactions between solid particles. While the PIEP model is a powerful tool, its pairwise assumption leads to increased error in flows with high particle volume fractions. To reduce this error, a regression algorithm is used to model the differences between the current PIEP model's predictions and the results of direct numerical simulations (DNS) for an array of monodisperse solid particles subjected to various flow conditions. The resulting statistical model and the physical PIEP model are superimposed to construct a hybrid, physics-based data-driven PIEP model. It must be noted that the performance of a pure data-driven approach without the model-form provided by the physical PIEP model is substantially inferior. The hybrid model's predictive capabilities are analyzed using more DNS. In every case tested, the hybrid PIEP model's prediction are more accurate than those of physical PIEP model. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship Program under Grant No. DGE-1315138 and the U.S. DOE, NNSA, ASC Program, as a Cooperative Agreement under Contract No. DE-NA0002378.

Particle Dark Matter constraints: the effect of Galactic uncertainties

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benito, Maria; Bernal, Nicolás; Iocco, Fabio

2017-02-01

Collider, space, and Earth based experiments are now able to probe several extensions of the Standard Model of particle physics which provide viable dark matter candidates. Direct and indirect dark matter searches rely on inputs of astrophysical nature, such as the local dark matter density or the shape of the dark matter density profile in the target in object. The determination of these quantities is highly affected by astrophysical uncertainties. The latter, especially those for our own Galaxy, are ill-known, and often not fully accounted for when analyzing the phenomenology of particle physics models. In this paper we present amore » systematic, quantitative estimate of how astrophysical uncertainties on Galactic quantities (such as the local galactocentric distance, circular velocity, or the morphology of the stellar disk and bulge) propagate to the determination of the phenomenology of particle physics models, thus eventually affecting the determination of new physics parameters. We present results in the context of two specific extensions of the Standard Model (the Singlet Scalar and the Inert Doublet) that we adopt as case studies for their simplicity in illustrating the magnitude and impact of such uncertainties on the parameter space of the particle physics model itself. Our findings point toward very relevant effects of current Galactic uncertainties on the determination of particle physics parameters, and urge a systematic estimate of such uncertainties in more complex scenarios, in order to achieve constraints on the determination of new physics that realistically include all known uncertainties.« less

Measurement and Modeling of Electromagnetic Scattering by Particles and Particle Groups. Chapter 3

NASA Technical Reports Server (NTRS)

Mishchenko, Michael I.

2015-01-01

Small particles forming clouds of interstellar and circumstellar dust, regolith surfaces of many solar system bodies, and cometary atmospheres have a strong and often controlling effect on many ambient physical and chemical processes. Similarly, aerosol and cloud particles exert a strong influence on the regional and global climates of the Earth, other planets of the solar system, and exoplanets. Therefore, detailed and accurate knowledge of physical and chemical characteristics of such particles has the utmost scientific importance.

A methodology for the rigorous verification of plasma simulation codes

NASA Astrophysics Data System (ADS)

Riva, Fabio

2016-10-01

The methodology used to assess the reliability of numerical simulation codes constitutes the Verification and Validation (V&V) procedure. V&V is composed by two separate tasks: the verification, which is a mathematical issue targeted to assess that the physical model is correctly solved, and the validation, which determines the consistency of the code results, and therefore of the physical model, with experimental data. In the present talk we focus our attention on the verification, which in turn is composed by the code verification, targeted to assess that a physical model is correctly implemented in a simulation code, and the solution verification, that quantifies the numerical error affecting a simulation. Bridging the gap between plasma physics and other scientific domains, we introduced for the first time in our domain a rigorous methodology for the code verification, based on the method of manufactured solutions, as well as a solution verification based on the Richardson extrapolation. This methodology was applied to GBS, a three-dimensional fluid code based on a finite difference scheme, used to investigate the plasma turbulence in basic plasma physics experiments and in the tokamak scrape-off layer. Overcoming the difficulty of dealing with a numerical method intrinsically affected by statistical noise, we have now generalized the rigorous verification methodology to simulation codes based on the particle-in-cell algorithm, which are employed to solve Vlasov equation in the investigation of a number of plasma physics phenomena.

Respiratory dose assessment of inhaled particles: continuing progress

EPA Science Inventory

Internal dose is a key factor for determining the health risk ofinhaled pollutant particles on the one hand and the efficacy ofdrug inhalantsonthe other. Accurateestimation ofrespiratorydose, however, is a difficult task because multiple factors come to play roles in the process....

A framework for the design and development of physical employment tests and standards.

PubMed

Payne, W; Harvey, J

2010-07-01

Because operational tasks in the uniformed services (military, police, fire and emergency services) are physically demanding and incur the risk of injury, employment policy in these services is usually competency based and predicated on objective physical employment standards (PESs) based on physical employment tests (PETs). In this paper, a comprehensive framework for the design of PETs and PESs is presented. Three broad approaches to physical employment testing are described and compared: generic predictive testing; task-related predictive testing; task simulation testing. Techniques for the selection of a set of tests with good coverage of job requirements, including job task analysis, physical demands analysis and correlation analysis, are discussed. Regarding individual PETs, theoretical considerations including measurability, discriminating power, reliability and validity, and practical considerations, including development of protocols, resource requirements, administrative issues and safety, are considered. With regard to the setting of PESs, criterion referencing and norm referencing are discussed. STATEMENT OF RELEVANCE: This paper presents an integrated and coherent framework for the development of PESs and hence provides a much needed theoretically based but practically oriented guide for organisations seeking to establish valid and defensible PESs.

Correlations between Physical Fitness Tests and Performance of Military Tasks: A Systematic Review and Meta-Analyses

DTIC Science & Technology

2014-06-30

U.S. Army Public Health Command Correlations between Physical Fitness Tests and Performance of Military Tasks: A Systematic Review and Meta...30 JUN 2014 2. REPORT TYPE Final 3. DATES COVERE D 4. TITLE AN D SUBTITLE Correlations between Physical Fitness Tests and Performance of... Physical Fitness Test (APFT) and ensure a future test is associated with Soldiers’ performance of common physical job requirements, the USAPHC applied

Quantum Optics, Diffraction Theory, and Elementary Particle Physics

ScienceCinema

Glauber, Roy

2018-05-22

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

Impact of Indoor Physical Environment on Learning Efficiency in Different Types of Tasks: A 3 × 4 × 3 Full Factorial Design Analysis.

PubMed

Xiong, Lilin; Huang, Xiao; Li, Jie; Mao, Peng; Wang, Xiang; Wang, Rubing; Tang, Meng

2018-06-13

Indoor physical environments appear to influence learning efficiency nowadays. For improvement in learning efficiency, environmental scenarios need to be designed when occupants engage in different learning tasks. However, how learning efficiency is affected by indoor physical environment based on task types are still not well understood. The present study aims to explore the impacts of three physical environmental factors (i.e., temperature, noise, and illuminance) on learning efficiency according to different types of tasks, including perception, memory, problem-solving, and attention-oriented tasks. A 3 × 4 × 3 full factorial design experiment was employed in a university classroom with 10 subjects recruited. Environmental scenarios were generated based on different levels of temperature (17 °C, 22 °C, and 27 °C), noise (40 dB(A), 50 dB(A), 60 dB(A), and 70 dB(A)) and illuminance (60 lx, 300 lx, and 2200 lx). Accuracy rate (AC), reaction time (RT), and the final performance indicator (PI) were used to quantify learning efficiency. The results showed ambient temperature, noise, and illuminance exerted significant main effect on learning efficiency based on four task types. Significant concurrent effects of the three factors on final learning efficiency was found in all tasks except problem-solving-oriented task. The optimal environmental scenarios for top learning efficiency were further identified under different environmental interactions. The highest learning efficiency came in thermoneutral, relatively quiet, and bright conditions in perception-oriented task. Subjects performed best under warm, relatively quiet, and moderately light exposure when recalling images in the memory-oriented task. Learning efficiency peaked to maxima in thermoneutral, fairly quiet, and moderately light environment in problem-solving process while in cool, fairly quiet and bright environment with regard to attention-oriented task. The study provides guidance for building users to conduct effective environmental intervention with simultaneous controls of ambient temperature, noise, and illuminance. It contributes to creating the most suitable indoor physical environment for improving occupants learning efficiency according to different task types. The findings could further supplement the present indoor environment-related standards or norms with providing empirical reference on environmental interactions.

Subjective evaluation of physical and mental workload interactions across different muscle groups.

PubMed

Mehta, Ranjana K; Agnew, Michael J

2015-01-01

Both physical and mental demands, and their interactions, have been shown to increase biomechanical loading and physiological reactivity as well as impair task performance. Because these interactions have shown to be muscle-dependent, the aim of this study was to determine the sensitivity of the NASA Task Load Index (NASA TLX) and Ratings of Perceived Exertion (RPE) to evaluate physical and mental workload during muscle-specific tasks. Twenty-four participants performed upper extremity and low back exertions at three physical workload levels in the absence and presence of a mental stressor. Outcome measures included RPE and NASA TLX (six sub-scales) ratings. The findings indicate that while both RPEs and NASA TLX ratings were sensitive to muscle-specific changes in physical demand, only an additional mental stressor and its interaction with either physical demand or muscle groups influenced the effort sub-scale and overall workload scores of the NASA TLX. While additional investigations in actual work settings are warranted, the NASA TLX shows promise in evaluating perceived workload that is sensitive not only to physical and mental demands but also sensitive in determining workload for tasks that employ different muscle groups.

They Won't All Grow Up to Be You: Preparing Students for Diverse Careers

NASA Astrophysics Data System (ADS)

McNeil, Laurie

The Joint Task Force on Undergraduate Physics Programs (J-TUPP) was formed in response to a growing awareness in the physics community that undergraduate physics majors pursue a wide range of careers after graduation, with very few ending up employed as physics professors. The task force was charged to identify the skills and knowledge that undergraduate physics degree holders should possess to be well prepared for a diverse set of careers, and to provide guidance on how physicists could revise the undergraduate curriculum to improve the education of a diverse student population. Our report (issued in October 2016) is the result of the task force's reviews of employment data, surveys of employers, and reports generated by other disciplines, as well as meetings with physicists in selected industries and interviews with recent physics graduates employed in the private sector. As part of our study we also identified exemplary programs that provide models of how physics departments can ensure that all of their students are well prepared to pursue a wide range of career paths. I will summarize and illustrate the findings and recommendations contained in the task force's report.

Momentum Probabilities for a Single Quantum Particle in Three-Dimensional Regular "Infinite" Wells: One Way of Promoting Understanding of Probability Densities

ERIC Educational Resources Information Center

Riggs, Peter J.

2013-01-01

Students often wrestle unsuccessfully with the task of correctly calculating momentum probability densities and have difficulty in understanding their interpretation. In the case of a particle in an "infinite" potential well, its momentum can take values that are not just those corresponding to the particle's quantised energies but…

Method and Apparatus for Performance Optimization Through Physical Perturbation of Task Elements

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III (Inventor); Pope, Alan T. (Inventor); Palsson, Olafur S. (Inventor); Turner, Marsha J. (Inventor)

2016-01-01

The invention is an apparatus and method of biofeedback training for attaining a physiological state optimally consistent with the successful performance of a task, wherein the probability of successfully completing the task is made is inversely proportional to a physiological difference value, computed as the absolute value of the difference between at least one physiological signal optimally consistent with the successful performance of the task and at least one corresponding measured physiological signal of a trainee performing the task. The probability of successfully completing the task is made inversely proportional to the physiological difference value by making one or more measurable physical attributes of the environment in which the task is performed, and upon which completion of the task depends, vary in inverse proportion to the physiological difference value.

Promoting Physical Activity in Hong Kong Chinese Young People: Factors Influencing Their Subjective Task Values and Expectancy Beliefs in Physical Activity

ERIC Educational Resources Information Center

Pang, Bonnie

2014-01-01

According to Eccles et al.'s (1983) Expectancy Value Model, the two major constructs that influence young people's activity choice are subjective task value and expectancy beliefs (Eccles et al., 1983). Eccles et al. (1983) conceptually distinguished four dimensions of subjective task value: attainment value, intrinsic value, utility value and…

Elementary particle physics

NASA Technical Reports Server (NTRS)

Perkins, D. H.

1986-01-01

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

A proposed physical analog for a quantum probability amplitude

NASA Astrophysics Data System (ADS)

Boyd, Jeffrey

What is the physical analog of a probability amplitude? All quantum mathematics, including quantum information, is built on amplitudes. Every other science uses probabilities; QM alone uses their square root. Why? This question has been asked for a century, but no one previously has proposed an answer. We will present cylindrical helices moving toward a particle source, which particles follow backwards. Consider Feynman's book QED. He speaks of amplitudes moving through space like the hand of a spinning clock. His hand is a complex vector. It traces a cylindrical helix in Cartesian space. The Theory of Elementary Waves changes direction so Feynman's clock faces move toward the particle source. Particles follow amplitudes (quantum waves) backwards. This contradicts wave particle duality. We will present empirical evidence that wave particle duality is wrong about the direction of particles versus waves. This involves a paradigm shift; which are always controversial. We believe that our model is the ONLY proposal ever made for the physical foundations of probability amplitudes. We will show that our ``probability amplitudes'' in physical nature form a Hilbert vector space with adjoints, an inner product and support both linear algebra and Dirac notation.

HIGH ENERGY PHYSICS: CERN Link Breathes Life Into Russian Physics.

PubMed

Stone, R

2000-10-13

Without fanfare, 600 Russian scientists here at CERN, the European particle physics laboratory, are playing key roles in building the Large Hadron Collider (LHC), a machine that will explore fundamental questions such as why particles have mass, as well as search for exotic new particles whose existence would confirm supersymmetry, a popular theory that aims to unify the four forces of nature. In fact, even though Russia is not one of CERN's 20 member states, most top high-energy physicists in Russia are working on the LHC. Some say their work could prove the salvation of high-energy physics back home.

The Influence of Instructional Climates on Time Spent in Management Tasks and Physical Activity of 2nd-Grade Students during Physical Education

ERIC Educational Resources Information Center

Logan, Samuel W.; Robinson, Leah E.; Webster, E. Kipling; Rudisill, Mary E.

2015-01-01

The purpose of this study is to determine the effect of two physical education (PE) instructional climates (mastery, performance) on the percentage of time students spent in a) moderate-to-vigorous physical activity (MVPA) and b) management tasks during PE in 2nd-grade students. Forty-eight 2nd graders (mastery, n = 23; performance, n = 25)…

Visualization assisted by parallel processing

NASA Astrophysics Data System (ADS)

Lange, B.; Rey, H.; Vasques, X.; Puech, W.; Rodriguez, N.

2011-01-01

This paper discusses the experimental results of our visualization model for data extracted from sensors. The objective of this paper is to find a computationally efficient method to produce a real time rendering visualization for a large amount of data. We develop visualization method to monitor temperature variance of a data center. Sensors are placed on three layers and do not cover all the room. We use particle paradigm to interpolate data sensors. Particles model the "space" of the room. In this work we use a partition of the particle set, using two mathematical methods: Delaunay triangulation and Voronoý cells. Avis and Bhattacharya present these two algorithms in. Particles provide information on the room temperature at different coordinates over time. To locate and update particles data we define a computational cost function. To solve this function in an efficient way, we use a client server paradigm. Server computes data and client display this data on different kind of hardware. This paper is organized as follows. The first part presents related algorithm used to visualize large flow of data. The second part presents different platforms and methods used, which was evaluated in order to determine the better solution for the task proposed. The benchmark use the computational cost of our algorithm that formed based on located particles compared to sensors and on update of particles value. The benchmark was done on a personal computer using CPU, multi core programming, GPU programming and hybrid GPU/CPU. GPU programming method is growing in the research field; this method allows getting a real time rendering instates of a precompute rendering. For improving our results, we compute our algorithm on a High Performance Computing (HPC), this benchmark was used to improve multi-core method. HPC is commonly used in data visualization (astronomy, physic, etc) for improving the rendering and getting real-time.

News Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

NASA Astrophysics Data System (ADS)

2010-05-01

Teaching: The epiSTEMe project: KS3 maths and science improvement Field trip: Pupils learn physics in a stately home Conference: ShowPhysics welcomes fun in Europe Student numbers: Physics numbers increase in UK Tournament: Physics tournament travels to Singapore Particle physics: Hadron Collider sets new record Astronomy: Take your classroom into space Forthcoming Events

Fact Sheets and Brochures | News

Science.gov Websites

Illinois Accelerator Research Center Economic Impact Particle Physics: Benefits to Society The Fermilab Saturday Morning Physics What are neutrinos? What are neutrinos? (large format) What is a Higgs boson? U.S Public Outreach America's particle physics and accelerator laboratory LBNF/DUNE - An international mega

CQPSO scheduling algorithm for heterogeneous multi-core DAG task model

NASA Astrophysics Data System (ADS)

Zhai, Wenzheng; Hu, Yue-Li; Ran, Feng

2017-07-01

Efficient task scheduling is critical to achieve high performance in a heterogeneous multi-core computing environment. The paper focuses on the heterogeneous multi-core directed acyclic graph (DAG) task model and proposes a novel task scheduling method based on an improved chaotic quantum-behaved particle swarm optimization (CQPSO) algorithm. A task priority scheduling list was built. A processor with minimum cumulative earliest finish time (EFT) was acted as the object of the first task assignment. The task precedence relationships were satisfied and the total execution time of all tasks was minimized. The experimental results show that the proposed algorithm has the advantage of optimization abilities, simple and feasible, fast convergence, and can be applied to the task scheduling optimization for other heterogeneous and distributed environment.

Assessing abuse risk beyond self-report: analog task of acceptability of parent-child aggression.

PubMed

Rodriguez, Christina M; Russa, Mary Bower; Harmon, Nancy

2011-03-01

The present investigation reports on the development and initial validation of a new analog task, the Parent-Child Aggression Acceptability Movie Task (P-CAAM), intended to assess respondents' acceptance of parent-child aggression, including both physical discipline and physical abuse. Two independent samples were utilized to develop and evaluate the P-CAAM: an undergraduate sample to initially pilot the task and a separate sample of normative parents for additional assessment of validity. Scores from the P-CAAM were compared to related measures, including measures of self-reported disciplinary attitudes, child abuse potential, harsh parenting style, and use and escalation of physical discipline practices on another analog parenting task. Across the studies, the P-CAAM demonstrated acceptable internal consistency and construct validity, evidencing mild to moderate associations with both self-report and analog measures. Participants demonstrating increased acceptance of physical discipline and physical abuse on the P-CAAM analog task also reported greater approval of physical discipline, greater use of and escalation of physical discipline, harsher parenting styles, and higher child abuse potential on two separate measures. The P-CAAM analog appears to offer a promising alternative and/or supplement to conventional self-report measures, assessing attitudes regarding the acceptability of parent-child aggression in a way that is less likely to be influenced by social desirability. Suggestions for future evaluations with alternative samples, as well as possible implications of the data for disciplinary reactions are discussed. The development of alternatives to self-report measurement may lead to clarification of theoretical models of abuse in ways that lead to improvements in intervention programming; analogs may also provide a useful means to assess intervention programming outcomes. Copyright © 2011 Elsevier Ltd. All rights reserved.

Design Considerations for High Energy Electron -- Positron Storage Rings

DOE R&D Accomplishments Database

Richter, B.

1966-11-01

High energy electron-positron storage rings give a way of making a new attack on the most important problems of elementary particle physics. All of us who have worked in the storage ring field designing, building, or using storage rings know this. The importance of that part of storage ring work concerning tests of quantum electrodynamics and mu meson physics is also generally appreciated by the larger physics community. However, I do not think that most of the physicists working tin the elementary particle physics field realize the importance of the contribution that storage ring experiments can make to our understanding of the strongly interacting particles. I would therefore like to spend the next few minutes discussing the sort of things that one can do with storage rings in the strongly interacting particle field.

Performance differences between male and female marines on standardized physical fitness tests and combat proxy tasks: identifying the gap.

PubMed

Jameson, Jason; Pappa, Leon; McGuire, Brian; Kelly, Karen R

2015-01-01

For decades women have been restricted from direct assignment to certain military occupational specialties such as infantry. These restrictions can limit the advancement of women through the ranks of military leadership. Thus, the purpose of this effort was to identify those physical requirements most likely to serve as barriers for women wanting to enter closed combat arms positions, and to evaluate the quality of existing physical fitness tests as potential measures of assessment of combat readiness. Data were collected from 3 different sites within the US Marine Corps Training and Education Command. All participants (409 male, 379 femaile) were active-duty Marines who recently completed the Physical Fitness Test (PFT) and Combat Fitness Test (CFT). Participants completed 6 physical tasks: 120-mm tank loading drill, 155-mm artillery round carry, negotiating an obstacle course wall while wearing a fighting load (≈30 lb), pull-ups, deadlift, and clean and press. Overall, there was a high rate of successful completion on the combat proxy tasks (men, ≈80% to 100%; women, ≈70% to 100%), with the notable exception being the clean and press (men, 80%; women, 9%) and pull-ups (men, 16±4; women, 4±2). The PFT and CFT components tasks were also related, strongly in some cases, with performance on combat-related proxy tasks (Spearman's ρ typically ranged from 0.60 to 0.80). Estimates of fat-free mass and VO2max were also strongly related to an overall measure of combat readiness (Spearman's ρ=0.77 and ρ=0.56, respectively). The primary physical obstacle for women is upper body strength. However, some women could successfully complete all of the proxy tasks and thus are physically capable of meeting the demands of closed combat occupations. The fact that some female Marines could complete the most challenging upper body strength tasks suggests that these barriers are not inherent but may be due to a lack of training specificity.

Particle Detectors

NASA Astrophysics Data System (ADS)

Grupen, Claus; Shwartz, Boris

2011-09-01

Preface to the first edition; Preface to the second edition; Introduction; 1. Interactions of particles and radiation with matter; 2. Characteristic properties of detectors; 3. Units of radiation measurements and radiation sources; 4. Accelerators; 5. Main physical phenomena used for particle detection and basic counter types; 6. Historical track detectors; 7. Track detectors; 8. Calorimetry; 9. Particle identification; 10. Neutrino detectors; 11. Momentum measurement and muon detection; 12. Ageing and radiation effects; 13. Example of a general-purpose detector: Belle; 14. Electronics; 15. Data analysis; 16. Applications of particle detectors outside particle physics; 17. Glossary; 18. Solutions; 19. Resumé; Appendixes; Index.

CAE "FOCUS" for modelling and simulating electron optics systems: development and application

NASA Astrophysics Data System (ADS)

Trubitsyn, Andrey; Grachev, Evgeny; Gurov, Victor; Bochkov, Ilya; Bochkov, Victor

2017-02-01

Electron optics is a theoretical base of scientific instrument engineering. Mathematical simulation of occurring processes is a base for contemporary design of complicated devices of the electron optics. Problems of the numerical mathematical simulation are effectively solved by CAE system means. CAE "FOCUS" developed by the authors includes fast and accurate methods: boundary element method (BEM) for the electric field calculation, Runge-Kutta- Fieghlberg method for the charged particle trajectory computation controlling an accuracy of calculations, original methods for search of terms for the angular and time-of-flight focusing. CAE "FOCUS" is organized as a collection of modules each of which solves an independent (sub) task. A range of physical and analytical devices, in particular a microfocus X-ray tube of high power, has been developed using this soft.

Machine learning action parameters in lattice quantum chromodynamics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shanahan, Phiala; Trewartha, Daneil; Detmold, William

Numerical lattice quantum chromodynamics studies of the strong interaction underpin theoretical understanding of many aspects of particle and nuclear physics. Such studies require significant computing resources to undertake. A number of proposed methods promise improved efficiency of lattice calculations, and access to regions of parameter space that are currently computationally intractable, via multi-scale action-matching approaches that necessitate parametric regression of generated lattice datasets. The applicability of machine learning to this regression task is investigated, with deep neural networks found to provide an efficient solution even in cases where approaches such as principal component analysis fail. Finally, the high information contentmore » and complex symmetries inherent in lattice QCD datasets require custom neural network layers to be introduced and present opportunities for further development.« less

Expert System Approach For Generating And Evaluating Engine Design Alternatives

NASA Astrophysics Data System (ADS)

Shen, Stewart N. T.; Chew, Meng-Sang; Issa, Ghassan F.

1989-03-01

Artificial intelligence is becoming an increasingly important subject of study for computer scientists, engineering designers, as well as professionals in other fields. Even though AI technology is a relatively new discipline, many of its concepts have already found practical applications. Expert systems, in particular, have made significant contributions to technologies in such fields as business, medicine, engineering design, chemistry, and particle physics. This paper describes an expert system developed to aid the mechanical designer with the preliminary design of variable-stroke internal-combustion engines. The expert system accomplished its task by generating and evaluating a large number of design alternatives represented in the form of graphs. Through the application of structural and design rules directly to the graphs, optimal and near optimal preliminary design configurations of engines are deduced.

Machine learning action parameters in lattice quantum chromodynamics

DOE PAGES

Shanahan, Phiala; Trewartha, Daneil; Detmold, William

2018-05-16

Numerical lattice quantum chromodynamics studies of the strong interaction underpin theoretical understanding of many aspects of particle and nuclear physics. Such studies require significant computing resources to undertake. A number of proposed methods promise improved efficiency of lattice calculations, and access to regions of parameter space that are currently computationally intractable, via multi-scale action-matching approaches that necessitate parametric regression of generated lattice datasets. The applicability of machine learning to this regression task is investigated, with deep neural networks found to provide an efficient solution even in cases where approaches such as principal component analysis fail. Finally, the high information contentmore » and complex symmetries inherent in lattice QCD datasets require custom neural network layers to be introduced and present opportunities for further development.« less

GridPP - Preparing for LHC Run 2 and the Wider Context

NASA Astrophysics Data System (ADS)

Coles, Jeremy

2015-12-01

This paper elaborates upon the operational status and directions within the UK Computing for Particle Physics (GridPP) project as it approaches LHC Run 2. It details the pressures that have been gradually reshaping the deployed hardware and middleware environments at GridPP sites - from the increasing adoption of larger multicore nodes to the move towards alternative batch systems and cloud alternatives - as well as changes being driven by funding considerations. The paper highlights work being done with non-LHC communities and describes some of the early outcomes of adopting a generic DIRAC based job submission and management framework. The paper presents results from an analysis of how GridPP effort is distributed across various deployment and operations tasks and how this may be used to target further improvements in efficiency.

Belle2VR: A Virtual-Reality Visualization of Subatomic Particle Physics in the Belle II Experiment.

PubMed

Duer, Zach; Piilonen, Leo; Glasson, George

2018-05-01

Belle2VR is an interactive virtual-reality visualization of subatomic particle physics, designed by an interdisciplinary team as an educational tool for learning about and exploring subatomic particle collisions. This article describes the tool, discusses visualization design decisions, and outlines our process for collaborative development.

Lithium Gadolinium Borate in Plastic Scintillator as an Antineutrino Detection Material

DTIC Science & Technology

2010-06-01

advancement of fundamental particle physics, development of the standard model of particle physics and our understanding many cosmological processes...MeVee). Where the light produced by by a 1MeV electron is 1 MeVee by definition , but a heavy charged particle would have a kinetic energy of several

Teaching Particle Physics in the Open University's Science Foundation Course.

ERIC Educational Resources Information Center

Farmelo, Graham

1992-01-01

Discusses four topics presented in the science foundation course of the Open University that exemplify current developments in particle physics, in particular, and that describe important issues about the nature of science, in general. Topics include the omega minus particle, the diversity of quarks, the heavy lepton, and the discovery of the W…

Future particle-physics projects in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denisov, D. S., E-mail: denisovd@fnal.gov

2015-07-15

Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.

Future particle-physics projects in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Denisov, D. S.

2015-08-25

Basic proposals of experiments aimed at precision measurements of Standard Model parameters and at searches for new particles, including dark-matter particles, are described along with future experimental projects considered by American Physical Society at the meeting in the summer of 2013 and intended for implementation within the next ten to twenty years.

Comprehensive model for predicting elemental composition of coal pyrolysis products

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ricahrds, Andrew P.; Shutt, Tim; Fletcher, Thomas H.

Large-scale coal combustion simulations depend highly on the accuracy and utility of the physical submodels used to describe the various physical behaviors of the system. Coal combustion simulations depend on the particle physics to predict product compositions, temperatures, energy outputs, and other useful information. The focus of this paper is to improve the accuracy of devolatilization submodels, to be used in conjunction with other particle physics models. Many large simulations today rely on inaccurate assumptions about particle compositions, including that the volatiles that are released during pyrolysis are of the same elemental composition as the char particle. Another common assumptionmore » is that the char particle can be approximated by pure carbon. These assumptions will lead to inaccuracies in the overall simulation. There are many factors that influence pyrolysis product composition, including parent coal composition, pyrolysis conditions (including particle temperature history and heating rate), and others. All of these factors are incorporated into the correlations to predict the elemental composition of the major pyrolysis products, including coal tar, char, and light gases.« less

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

ERIC Educational Resources Information Center

Gourlay, H.

2017-01-01

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

Particle transport and deposition: basic physics of particle kinetics

PubMed Central

Tsuda, Akira; Henry, Frank S.; Butler, James P.

2015-01-01

The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. Whereas the particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic, this interaction can be beneficial for disease treatment if the inhaled particles are therapeutic aerosolized drug. In either case, an accurate estimation of dose and sites of deposition in the respiratory tract is fundamental to understanding subsequent biological response, and the basic physics of particle motion and engineering knowledge needed to understand these subjects is the topic of this chapter. A large portion of this chapter deals with three fundamental areas necessary to the understanding of particle transport and deposition in the respiratory tract. These are: 1) the physical characteristics of particles, 2) particle behavior in gas flow, and 3) gas flow patterns in the respiratory tract. Other areas, such as particle transport in the developing lung and in the diseased lung are also considered. The chapter concludes with a summary and a brief discussion of areas of future research. PMID:24265235

Preschool physics: Using the invisible property of weight in causal reasoning tasks

PubMed Central

Williamson, Rebecca A.; Meltzoff, Andrew N.

2018-01-01

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects—an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children’s understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children’s performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult. PMID:29561840

Preschool physics: Using the invisible property of weight in causal reasoning tasks.

PubMed

Wang, Zhidan; Williamson, Rebecca A; Meltzoff, Andrew N

2018-01-01

Causal reasoning is an important aspect of scientific thinking. Even young human children can use causal reasoning to explain observations, make predictions, and design actions to bring about specific outcomes in the physical world. Weight is an interesting type of cause because it is an invisible property. Here, we tested preschool children with causal problem-solving tasks that assessed their understanding of weight. In an experimental setting, 2- to 5-year-old children completed three different tasks in which they had to use weight to produce physical effects-an object displacement task, a balance-scale task, and a tower-building task. The results showed that the children's understanding of how to use object weight to produce specific object-to-object causal outcomes improved as a function of age, with 4- and 5-year-olds showing above-chance performance on all three tasks. The younger children's performance was more variable. The pattern of results provides theoretical insights into which aspects of weight processing are particularly difficult for preschool children and why they find it difficult.

In Search of the Freedom to Grow: Report of the Physical Education/Athletics Task Force.

ERIC Educational Resources Information Center

Atkinson, Karla

Many physical educators, administrators, and parents argue that it makes little sense to spend time and money building athletic programs for young women when they are not interested in pursuing sports activities. Such an attitude is explored in this Task Force report questioning what roles, if any, physical education teachers have predetermined…

REPORT OF RESEARCH ACTIVITIES FOR THE YEARS 2000 - 2003; HIGH ENERGY PHYSICS GROUP; SOUTHERN METHODIST UNIVERSITY; EXPERIMENTAL TASK A AND THEORY TASK B

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Ryszard Stroynowski

2003-07-01

The experimental program in High Energy Physics at SMU was initiated in 1992. Its main goal is the search for new physics phenomena beyond the Standard Model (SSC, LHC) and the study of the properties of heavy quarks and leptons (CLEO, BTeV).

G4DARI: Geant4/GATE based Monte Carlo simulation interface for dosimetry calculation in radiotherapy.

PubMed

Slimani, Faiçal A A; Hamdi, Mahdjoub; Bentourkia, M'hamed

2018-05-01

Monte Carlo (MC) simulation is widely recognized as an important technique to study the physics of particle interactions in nuclear medicine and radiation therapy. There are different codes dedicated to dosimetry applications and widely used today in research or in clinical application, such as MCNP, EGSnrc and Geant4. However, such codes made the physics easier but the programming remains a tedious task even for physicists familiar with computer programming. In this paper we report the development of a new interface GEANT4 Dose And Radiation Interactions (G4DARI) based on GEANT4 for absorbed dose calculation and for particle tracking in humans, small animals and complex phantoms. The calculation of the absorbed dose is performed based on 3D CT human or animal images in DICOM format, from images of phantoms or from solid volumes which can be made from any pure or composite material to be specified by its molecular formula. G4DARI offers menus to the user and tabs to be filled with values or chemical formulas. The interface is described and as application, we show results obtained in a lung tumor in a digital mouse irradiated with seven energy beams, and in a patient with glioblastoma irradiated with five photon beams. In conclusion, G4DARI can be easily used by any researcher without the need to be familiar with computer programming, and it will be freely available as an application package. Copyright © 2018 Elsevier Ltd. All rights reserved.

Automatic Calibration of a Semi-Distributed Hydrologic Model Using Particle Swarm Optimization

NASA Astrophysics Data System (ADS)

Bekele, E. G.; Nicklow, J. W.

2005-12-01

Hydrologic simulation models need to be calibrated and validated before using them for operational predictions. Spatially-distributed hydrologic models generally have a large number of parameters to capture the various physical characteristics of a hydrologic system. Manual calibration of such models is a very tedious and daunting task, and its success depends on the subjective assessment of a particular modeler, which includes knowledge of the basic approaches and interactions in the model. In order to alleviate these shortcomings, an automatic calibration model, which employs an evolutionary optimization technique known as Particle Swarm Optimizer (PSO) for parameter estimation, is developed. PSO is a heuristic search algorithm that is inspired by social behavior of bird flocking or fish schooling. The newly-developed calibration model is integrated to the U.S. Department of Agriculture's Soil and Water Assessment Tool (SWAT). SWAT is a physically-based, semi-distributed hydrologic model that was developed to predict the long term impacts of land management practices on water, sediment and agricultural chemical yields in large complex watersheds with varying soils, land use, and management conditions. SWAT was calibrated for streamflow and sediment concentration. The calibration process involves parameter specification, whereby sensitive model parameters are identified, and parameter estimation. In order to reduce the number of parameters to be calibrated, parameterization was performed. The methodology is applied to a demonstration watershed known as Big Creek, which is located in southern Illinois. Application results show the effectiveness of the approach and model predictions are significantly improved.

Matlab fractal techniques used to study the structural degradation caused by alpha radiation to laser mirrors

NASA Astrophysics Data System (ADS)

Ioan, M.-R.

2018-01-01

Almost all optical diagnostic systems associated with classical particle accelerators or with new state-of-the-art particle accelerators, such as those developed within the European Collaboration ELI-NP (Extreme Light Infrastructure-Nuclear Physics) (involving extreme power laser beams), contain in their infrastructure high quality laser mirrors, used for their reflectivity and/or their partial transmittance. These high quality mirrors facilitate the extraction and handling of optical signals. When optical mirrors are exposed to high energy ionizing radiation fields, their optical and structural properties will change over time and their functionality will be affected, meaning that they will provide imprecise information. In some experiments, being exposed to mixed laser and accelerated particle beams, the deterioration of laser mirrors is even more acute, since the destruction mechanisms of both types of beams are cumulated. The main task of the work described in this paper was to find a novel specific method to analyse and highlight such degradation processes. By using complex fractal techniques integrated in a MATLAB code, the effects induced by alpha radiation to laser mirrors were studied. The fractal analysis technique represents an alternative approach to the classical Euclidean one. It can be applied for the characterization of the defects occurred in mirrors structure due to their exposure to high energy alpha particle beams. The proposed method may be further integrated into mirrors manufacturing process, as a testing instrument, to obtain better quality mirrors (enhanced resistance to high energy ionizing beams) by using different types of reflective coating materials and different deposition techniques. Moreover, the effect of high energy alpha ionizing particles on the optical properties of the exposed laser mirrors was studied by using spectrophotometric techniques.

Semiannual Status Report. [excitation of electromagnetic waves in the whistler frequency range

NASA Technical Reports Server (NTRS)

1994-01-01

During the last six months, we have continued our study of the excitation of electromagnetic waves in the whistler frequency range and the role that these waves will play in the acceleration of electrons and ions in the auroral region. A paper entitled 'Electron Beam Excitation of Upstream Waves in the Whistler Mode Frequency Range' was listed in the Journal of Geophysical Research. In this paper, we have shown that an anisotropic electron beam (or gyrating electron beam) is capable of generating both left-hand and right-hand polarized electromagnetic waves in the whistler frequency range. Since right-hand polarized electromagnetic waves can interact with background electrons and left-hand polarized waves can interact with background ions through cyclotron resonance, it is possible that these beam generated left-hand and right-hand polarized electromagnetic waves can accelerate either ions or electrons (or both), depending on the physical parameters under consideration. We are currently carrying out a comprehensive study of the electromagnetic whistler and lower hybrid like waves observed in the auroral zone using both wave and particle data. Our first task is to identify these wave modes and compare it with particle observations. Using both the DE-1 particle and wave measurements, we can positively identify those electromagnetics lower hybrid like waves as fast magnetosonic waves and the upper cutoff of these waves is the local lower hybrid frequency. From the upper cutoff of the frequency spectrum, one can infer the particle density and the result is in very good agreement with the particle data. Since these electromagnetic lower hybrid like waves can have frequencies extended down to the local ion cyclotron frequency, it practically confirms that they are not whistler waves.

Scientific program and abstracts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerich, C.

1983-01-01

The Fifth International Conference on High-Power Particle Beams is organized jointly by the Lawrence Livermore National Laboratory and Physics International Company. As in the previous conferences in this series, the program includes the following topics: high-power, electron- and ion-beam acceleration and transport; diode physics; high-power particle beam interaction with plasmas and dense targets; particle beam fusion (inertial confinement); collective ion acceleration; particle beam heating of magnetically confined plasmas; and generation of microwave/free-electron lasers.

The Learning Reconstruction of Particle System and Linear Momentum Conservation in Introductory Physics Course

NASA Astrophysics Data System (ADS)

Karim, S.; Saepuzaman, D.; Sriyansyah, S. P.

2016-08-01

This study is initiated by low achievement of prospective teachers in understanding concepts in introductory physics course. In this case, a problem has been identified that students cannot develop their thinking skills required for building physics concepts. Therefore, this study will reconstruct a learning process, emphasizing a physics concept building. The outcome will design physics lesson plans for the concepts of particle system as well as linear momentum conservation. A descriptive analysis method will be used in order to investigate the process of learning reconstruction carried out by students. In this process, the students’ conceptual understanding will be evaluated using essay tests for concepts of particle system and linear momentum conservation. The result shows that the learning reconstruction has successfully supported the students’ understanding of physics concept.

Physical capacity of rescue personnel in the mining industry

PubMed Central

Stewart, Ian B; McDonald, Michael D; Hunt, Andrew P; Parker, Tony W

2008-01-01

Background The mining industry has one of the highest occupational rates of serious injury and fatality. Mine staff involved with rescue operations are often required to respond to physically challenging situations. This paper describes the physical attributes of mining rescue personnel. Methods 91 rescue personnel (34 ± 8.6 yrs, 1.79 ± 0.07 m, 90 ± 15.0 kg) participating in the Queensland Mines Rescue Challenge completed a series of health-related and rescue-related fitness tasks. Health-related tasks comprised measurements of aerobic capacity (VO2max), abdominal endurance, abdominal strength, flexibility, lower back strength, leg strength, elbow flexion strength, shoulder strength, lower back endurance, and leg endurance. Rescue-related tasks comprised an incremental carry (IC), coal shovel (CS), and a hose drag (HD), completed in this order. Results Cardiovascular (VO2max) and muscular endurance was average or below average compared with the general population. Isometric strength did not decline with age. The rescue-related tasks were all extremely demanding with heart rate responses averaging greater than 88% of age predicted maximal heart rates. Heart rate recovery responses were more discriminating than heart rates recorded during the tasks, indicating the hose drag as the most physically demanding of the tasks. Conclusion Relying on actual rescues or mining related work to provide adequate training is generally insufficient to maintain, let alone increase, physical fitness. It is therefore recommended that standards of required physical fitness be developed and mines rescue personnel undergo regularly training (and assessment) in order to maintain these standards. PMID:18847510

Statistical Physics Experiments Using Dusty Plasmas

NASA Astrophysics Data System (ADS)

Goree, John

2016-10-01

Compared to other areas of physics research, Statistical Physics is heavily dominated by theory, with comparatively little experiment. One reason for the lack of experiments is the impracticality of tracking of individual atoms and molecules within a substance. Thus, there is a need for a different kind of experimental system, one where individual particles not only move stochastically as they collide with one another, but also are large enough to allow tracking. A dusty plasma can meet this need. A dusty plasma is a partially ionized gas containing small particles of solid matter. These micron-size particles gain thousands of electronic charges by collecting more electrons than ions. Their motions are dominated by Coulomb collisions with neighboring particles. In this so-called strongly coupled plasma, the dust particles self-organize in much the same way as atoms in a liquid or solid. Unlike atoms, however, these particles are large and slow, so that they can be tracked easily by video microscopy. Advantages of dusty plasma for experimental statistical physics research include particle tracking, lack of frictional contact with solid surfaces, and avoidance of overdamped motion. Moreover, the motion of a collection of dust particles can mimic an equilibrium system with a Maxwellian velocity distribution, even though the dust particles themselves are not truly in thermal equilibrium. Nonequilibrium statistical physics can be studied by applying gradients, for example by imposing a shear flow. In this talk I will review some of our recent experiments with shear flow. First, we performed the first experimental test to verify the Fluctuation Theorem for a shear flow, showing that brief violations of the Second Law of Thermodynamics occur with the predicted probabilities, for a small system. Second, we discovered a skewness of a shear-stress distribution in a shear flow. This skewness is a phenomenon that likely has wide applicability in nonequilibrium steady states. Third, we performed the first experimental test of a statistical physics theory (the Green-Kubo model) that is widely used by physical chemists to compute viscosity coefficients, and we found that it fails. Work supported by the U.S. Department of Energy, NSF, and NASA.

Extending self-organizing particle systems to problem solving.

PubMed

Rodríguez, Alejandro; Reggia, James A

2004-01-01

Self-organizing particle systems consist of numerous autonomous, purely reflexive agents ("particles") whose collective movements through space are determined primarily by local influences they exert upon one another. Inspired by biological phenomena (bird flocking, fish schooling, etc.), particle systems have been used not only for biological modeling, but also increasingly for applications requiring the simulation of collective movements such as computer-generated animation. In this research, we take some first steps in extending particle systems so that they not only move collectively, but also solve simple problems. This is done by giving the individual particles (agents) a rudimentary intelligence in the form of a very limited memory and a top-down, goal-directed control mechanism that, triggered by appropriate conditions, switches them between different behavioral states and thus different movement dynamics. Such enhanced particle systems are shown to be able to function effectively in performing simulated search-and-collect tasks. Further, computational experiments show that collectively moving agent teams are more effective than similar but independently moving ones in carrying out such tasks, and that agent teams of either type that split off members of the collective to protect previously acquired resources are most effective. This work shows that the reflexive agents of contemporary particle systems can readily be extended to support goal-directed problem solving while retaining their collective movement behaviors. These results may prove useful not only for future modeling of animal behavior, but also in computer animation, coordinated movement control in robotic teams, particle swarm optimization, and computer games.

PEOPLE IN PHYSICS: Interview with Peter Higgs

NASA Astrophysics Data System (ADS)

Fancey, Conducted by Norman

1998-01-01

Peter Higgs, FRSE, FRS held until recently a personal chair in theoretical physics at the University of Edinburgh and is now an emeritus professor. Peter is well known for predicting the existence of a new particle, the Higgs boson - as yet unconfirmed. He has been awarded a number of prizes in recognition of his work, most recently the Paul Dirac Medal and Prize for outstanding contributions to theoretical physics from the Institute of Physics and the 1997 High Energy and Particle Physics Prize by the European Physical Society.

Task Value Profiles across Subjects and Aspirations to Physical and IT-Related Sciences in the United States and Finland

ERIC Educational Resources Information Center

Chow, Angela; Eccles, Jacquelynne S.; Salmela-Aro, Katariina

2012-01-01

Two independent studies were conducted to extend previous research by examining the associations between task value priority patterns across school subjects and aspirations toward the physical and information technology- (IT-) related sciences. Study 1 measured task values of a sample of 10th graders in the United States (N = 249) across (a)…

Exploring physical exposures and identifying high-risk work tasks within the floor layer trade

PubMed Central

McGaha, Jamie; Miller, Kim; Descatha, Alexis; Welch, Laurie; Buchholz, Bryan; Evanoff, Bradley; Dale, Ann Marie

2014-01-01

Introduction Floor layers have high rates of musculoskeletal disorders yet few studies have examined their work exposures. This study used observational methods to describe physical exposures within floor laying tasks. Methods We analyzed 45 videos from 32 floor layers using Multimedia-Video Task Analysis software to determine the time in task, forces, postures, and repetitive hand movements for installation of four common flooring materials. We used the WISHA checklists to define exposure thresholds. Results Most workers (91%) met the caution threshold for one or more exposures. Workers showed high exposures in multiple body parts with variability in exposures across tasks and for different materials. Prolonged exposures were seen for kneeling, poor neck and low back postures, and intermittent but frequent hand grip forces. Conclusions Floor layers experience prolonged awkward postures and high force physical exposures in multiple body parts, which probably contribute to their high rates of musculoskeletal disorders. PMID:24274895

DOE SBIR Phase-1 Report on Hybrid CPU-GPU Parallel Development of the Eulerian-Lagrangian Barracuda Multiphase Program

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dr. Dale M. Snider

2011-02-28

This report gives the result from the Phase-1 work on demonstrating greater than 10x speedup of the Barracuda computer program using parallel methods and GPU processors (General-Purpose Graphics Processing Unit or Graphics Processing Unit). Phase-1 demonstrated a 12x speedup on a typical Barracuda function using the GPU processor. The problem test case used about 5 million particles and 250,000 Eulerian grid cells. The relative speedup, compared to a single CPU, increases with increased number of particles giving greater than 12x speedup. Phase-1 work provided a path for reformatting data structure modifications to give good parallel performance while keeping a friendlymore » environment for new physics development and code maintenance. The implementation of data structure changes will be in Phase-2. Phase-1 laid the ground work for the complete parallelization of Barracuda in Phase-2, with the caveat that implemented computer practices for parallel programming done in Phase-1 gives immediate speedup in the current Barracuda serial running code. The Phase-1 tasks were completed successfully laying the frame work for Phase-2. The detailed results of Phase-1 are within this document. In general, the speedup of one function would be expected to be higher than the speedup of the entire code because of I/O functions and communication between the algorithms. However, because one of the most difficult Barracuda algorithms was parallelized in Phase-1 and because advanced parallelization methods and proposed parallelization optimization techniques identified in Phase-1 will be used in Phase-2, an overall Barracuda code speedup (relative to a single CPU) is expected to be greater than 10x. This means that a job which takes 30 days to complete will be done in 3 days. Tasks completed in Phase-1 are: Task 1: Profile the entire Barracuda code and select which subroutines are to be parallelized (See Section Choosing a Function to Accelerate) Task 2: Select a GPU consultant company and jointly parallelize subroutines (CPFD chose the small business EMPhotonics for the Phase-1 the technical partner. See Section Technical Objective and Approach) Task 3: Integrate parallel subroutines into Barracuda (See Section Results from Phase-1 and its subsections) Task 4: Testing, refinement, and optimization of parallel methodology (See Section Results from Phase-1 and Section Result Comparison Program) Task 5: Integrate Phase-1 parallel subroutines into Barracuda and release (See Section Results from Phase-1 and its subsections) Task 6: Roadmap of Phase-2 (See Section Plan for Phase-2) With the completion of Phase 1 we have the base understanding to completely parallelize Barracuda. An overview of the work to move Barracuda to a parallelized code is given in Plan for Phase-2.« less

NSR&D FY17 Report: CartaBlanca Capability Enhancements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Long, Christopher Curtis; Dhakal, Tilak Raj; Zhang, Duan Zhong

Over the last several years, particle technology in the CartaBlanca code has been matured and has been successfully applied to a wide variety of physical problems. It has been shown that the particle methods, especially Los Alamos's dual domain material point method, is capable of computing many problems involves complex physics, chemistries accompanied by large material deformations, where the traditional finite element or Eulerian method encounter significant difficulties. In FY17, the CartaBlanca code has been enhanced with physical models and numerical algorithms. We started out to compute penetration and HE safety problems. Most of the year we focused on themore » TEPLA model improvement testing against the sweeping wave experiment by Gray et al., because it was found that pore growth and material failure are essentially important for our tasks and needed to be understood for modeling the penetration and the can experiments efficiently. We extended the TEPLA mode from the point view of ensemble phase average to include the effects of nite deformation. It is shown that the assumed pore growth model in TEPLA is actually an exact result from the theory. Alone this line, we then generalized the model to include finite deformations to consider nonlinear dynamics of large deformation. The interaction between the HE product gas and the solid metal is based on the multi-velocity formation. Our preliminary numerical results suggest good agreement between the experiment and the numerical results, pending further verification. To improve the parallel processing capabilities of the CartaBlanca code, we are actively working with the Next Generation Code (NGC) project to rewrite selected packages using C++. This work is expected to continue in the following years. This effort also makes the particle technology developed with CartaBlanca project available to other part of the laboratory. Working with the NGC project and rewriting some parts of the code also given us an opportunity to improve our numerical implementations of the method and to take advantage of recently advances in the numerical methods, such as multiscale algorithms.« less

An Integrated Higgs Force Theory

NASA Astrophysics Data System (ADS)

Colella, Antonio

2016-03-01

An Integrated Higgs force theory (IHFT) was based on 2 key requirement amplifications: a matter particle/Higgs force was one and inseparable; a matter particle/Higgs force bidirectionally condensed/evaporated from/to super force. These were basis of 5 theories: particle creation, baryogenesis, superpartner/quark decays, spontaneous symmetry breaking, and stellar black holes. Our universe's 129 matter/force particles contained 64 supersymmetric Higgs particles; 9 transient matter particles/Higgs forces decayed to 8 permanent matter particles/Higgs forces; mass was given to a matter particle by its Higgs force and gravitons; and sum of 8 Higgs force energies of 8 permanent matter particles was dark energy. An IHFT's essence is the intimate physical relationships between 8 theories. These theories are independent because physicists in one theory worked independently of physicists in the other seven. An IHFT's premise is without sacrificing their integrities, 8 independent existing theories are replaced by 8 interrelated amplified theories. Requirement amplifications provide interfaces between the 8 theories. Intimate relationships between 8 theories including the above 5 and string, Higgs forces, and Super Universe are described. The sorting category selected was F. PARTICLES AND FIELDS (e.g., F1 Higgs Physics, F10 Alternative Beyond the Standard Model Physics, F11 Dark Sector Theories and Searches, and F12 Particle Cosmology).

Fermilab | About Fermilab | Photo and Video Gallery

Science.gov Websites

LHC Dark matter and dark energy ADMX Muons More fundamental particles and forces Theory Scientific society Particle Physics 101 Science of matter, energy, space and time How particle physics discovery rarely interact with matter. thumb Med-Res Hi-Res A view of Fermilab's MINERvA detector with the MINOS

Meta-Analysis inside and outside Particle Physics: Two Traditions That Should Converge?

ERIC Educational Resources Information Center

Baker, Rose D.; Jackson, Dan

2013-01-01

The use of meta-analysis in medicine and epidemiology really took off in the 1970s. However, in high-energy physics, the Particle Data Group has been carrying out meta-analyses of measurements of particle masses and other properties since 1957. Curiously, there has been virtually no interaction between those working inside and outside particle…

Nuclear physics in particle therapy: a review

NASA Astrophysics Data System (ADS)

Durante, Marco; Paganetti, Harald

2016-09-01

Charged particle therapy has been largely driven and influenced by nuclear physics. The increase in energy deposition density along the ion path in the body allows reducing the dose to normal tissues during radiotherapy compared to photons. Clinical results of particle therapy support the physical rationale for this treatment, but the method remains controversial because of the high cost and of the lack of comparative clinical trials proving the benefit compared to x-rays. Research in applied nuclear physics, including nuclear interactions, dosimetry, image guidance, range verification, novel accelerators and beam delivery technologies, can significantly improve the clinical outcome in particle therapy. Measurements of fragmentation cross-sections, including those for the production of positron-emitting fragments, and attenuation curves are needed for tuning Monte Carlo codes, whose use in clinical environments is rapidly increasing thanks to fast calculation methods. Existing cross sections and codes are indeed not very accurate in the energy and target regions of interest for particle therapy. These measurements are especially urgent for new ions to be used in therapy, such as helium. Furthermore, nuclear physics hardware developments are frequently finding applications in ion therapy due to similar requirements concerning sensors and real-time data processing. In this review we will briefly describe the physics bases, and concentrate on the open issues.

Nuclear physics in particle therapy: a review.

PubMed

Durante, Marco; Paganetti, Harald

2016-09-01

Charged particle therapy has been largely driven and influenced by nuclear physics. The increase in energy deposition density along the ion path in the body allows reducing the dose to normal tissues during radiotherapy compared to photons. Clinical results of particle therapy support the physical rationale for this treatment, but the method remains controversial because of the high cost and of the lack of comparative clinical trials proving the benefit compared to x-rays. Research in applied nuclear physics, including nuclear interactions, dosimetry, image guidance, range verification, novel accelerators and beam delivery technologies, can significantly improve the clinical outcome in particle therapy. Measurements of fragmentation cross-sections, including those for the production of positron-emitting fragments, and attenuation curves are needed for tuning Monte Carlo codes, whose use in clinical environments is rapidly increasing thanks to fast calculation methods. Existing cross sections and codes are indeed not very accurate in the energy and target regions of interest for particle therapy. These measurements are especially urgent for new ions to be used in therapy, such as helium. Furthermore, nuclear physics hardware developments are frequently finding applications in ion therapy due to similar requirements concerning sensors and real-time data processing. In this review we will briefly describe the physics bases, and concentrate on the open issues.

What Is Light?. Students' Reflections on the Wave-Particle Duality of Light and the Nature of Physics

NASA Astrophysics Data System (ADS)

Henriksen, Ellen Karoline; Angell, Carl; Vistnes, Arnt Inge; Bungum, Berit

2018-03-01

Quantum physics describes light as having both particle and wave properties; however, there is no consensus about how to interpret this duality on an ontological level. This article explores how pre-university physics students, while working with learning material focusing on historical-philosophical aspects of quantum physics, interpreted the wave-particle duality of light and which views they expressed on the nature of physics. A thematic analysis was performed on 133 written responses about the nature of light, given in the beginning of the teaching sequence, and 55 audio-recorded small-group discussions addressing the wave-particle duality, given later in the sequence. Most students initially expressed a wave and particle view of light, but some of these gave an "uncritical duality description", accepting without question the two ontologically different descriptions of light. In the small-group discussions, students expressed more nuanced views. Many tried to reconcile the two descriptions using semi-classical reasoning; others entered into philosophical discussions about the status of the current scientific description of light and expected science to come up with a better model. Some found the wave description of light particularly challenging and lacked a conception of "what is waving". Many seemed to implicitly take a realist view on the description of physical phenomena, contrary with the Copenhagen interpretation which is prevalent in textbooks. Results are discussed in light of different interpretations of quantum physics, and we conclude by arguing for a historical-philosophical perspective as an entry point for upper secondary physics students to explore the development and interpretation of quantum physical concepts.

Optical knots and contact geometry II. From Ranada dyons to transverse and cosmetic knots

NASA Astrophysics Data System (ADS)

Kholodenko, Arkady L.

2016-08-01

Some time ago Ranada (1989) obtained new nontrivial solutions of the Maxwellian gauge fields without sources. These were reinterpreted in Kholodenko (2015) [10] (part I) as particle-like (monopoles, dyons, etc.). They were obtained by the method of Abelian reduction of the non-Abelian Yang-Mills functional. The developed method uses instanton-type calculations normally employed for the non-Abelian gauge fields. By invoking the electric-magnetic duality it then becomes possible to replace all known charges/masses by the particle-like solutions of the source-free Abelian gauge fields. To employ these results in high energy physics, it is essential to extend Ranada's results by carefully analyzing and classifying all dynamically generated knotted/linked structures in gauge fields, including those discovered by Ranada. This task is completed in this work. The study is facilitated by the recent progress made in solving the Moffatt conjecture. Its essence is stated as follows: in steady incompressible Euler-type fluids the streamlines could have knots/links of all types. By employing the correspondence between the ideal hydrodynamics and electrodynamics discussed in part I and by superimposing it with the already mentioned method of Abelian reduction, it is demonstrated that in the absence of boundaries only the iterated torus knots and links could be dynamically generated. Obtained results allow to develop further particle-knot/link correspondence studied in Kholodenko (2015) [13].

CERN launches high-school internship programme

NASA Astrophysics Data System (ADS)

Johnston, Hamish

2017-07-01

The CERN particle-physics lab has hosted 22 high-school students from Hungary in a pilot programme designed to show teenagers how science, technology, engineering and mathematics is used at the particle-physics lab.

Quarked! - Adventures in Particle Physics Education

NASA Astrophysics Data System (ADS)

MacDonald, Teresa; Bean, Alice

2009-01-01

Particle physics is a subject that can send shivers down the spines of students and educators alike-with visions of long mathematical equations and inscrutable ideas. This perception, along with a full curriculum, often leaves this topic the road less traveled until the latter years of school. Particle physics, including quarks, is typically not introduced until high school or university.1,2 Many of these concepts can be made accessible to younger students when presented in a fun and engaging way. Informal science institutions are in an ideal position to communicate new and challenging science topics in engaging and innovative ways and offer a variety of educational enrichment experiences for students that support and enhance science learning.3 Quarked!™ Adventures in the Subatomic Universe, a National Science Foundation EPSCoR-funded particle physics education program, provides classroom programs and online educational resources.

Detectors for Particle Radiation

NASA Astrophysics Data System (ADS)

Kleinknecht, Konrad

1999-01-01

This textbook provides a clear, concise and comprehensive review of the physical principles behind the devices used to detect charged particles and gamma rays, and the construction and performance of these many different types of detectors. Detectors for high-energy particles and radiation are used in many areas of science, especially particle physics and nuclear physics experiments, nuclear medicine, cosmic ray measurements, space sciences and geological exploration. This second edition includes all the latest developments in detector technology, including several new chapters covering micro-strip gas chambers, silicion strip detectors and CCDs, scintillating fibers, shower detectors using noble liquid gases, and compensating calorimeters for hadronic showers. This well-illustrated textbook contains examples from the many areas in science in which these detectors are used. It provides both a coursebook for students in physics, and a useful introduction for researchers in other fields.

Nuclear and particle physics, astrophysics and cosmology (NPAC) capability review

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redondo, Antonio

2010-01-01

The present document represents a summary self-assessment of the status of the Nuclear and Particle Physics, Astrophysics and Cosmology (NPAC) capability across Los Alamos National Laboratory (LANL). For the purpose of this review, we have divided the capability into four theme areas: Nuclear Physics, Particle Physics, Astrophysics and Cosmology, and Applied Physics. For each theme area we have given a general but brief description of the activities under the area, a list of the Laboratory divisions involved in the work, connections to the goals and mission of the Laboratory, a brief description of progress over the last three years, ourmore » opinion of the overall status of the theme area, and challenges and issues.« less

Enhancing Critical Thinking Skills and Writing Skills through the Variation in Non-Traditional Writing Task

ERIC Educational Resources Information Center

Sinaga, Parlindungan; Feranie, Shelly

2017-01-01

The research aims to identify the impacts of embedding non-traditional writing tasks within the course of modern physics conducted to the students of Physics Education and Physics Study Programs. It employed a quasi-experimental method with the pretest-posttest control group design. The used instruments were tests on conceptual mastery, tests on…

Particle Physics at the Cosmic, Intensity, and Energy Frontiers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Essig, Rouven

Major efforts at the Intensity, Cosmic, and Energy frontiers of particle physics are rapidly furthering our understanding of the fundamental constituents of Nature and their interactions. The overall objectives of this research project are (1) to interpret and develop the theoretical implications of the data collected at these frontiers and (2) to provide the theoretical motivation, basis, and ideas for new experiments and for new analyses of experimental data. Within the Intensity Frontier, an experimental search for a new force mediated by a GeV-scale gauge boson will be carried out with the $A'$ Experiment (APEX) and the Heavy Photon Searchmore » (HPS), both at Jefferson Laboratory. Within the Cosmic Frontier, contributions are planned to the search for dark matter particles with the Fermi Gamma-ray Space Telescope and other instruments. A detailed exploration will also be performed of new direct detection strategies for dark matter particles with sub-GeV masses to facilitate the development of new experiments. In addition, the theoretical implications of existing and future dark matter-related anomalies will be examined. Within the Energy Frontier, the implications of the data from the Large Hadron Collider will be investigated. Novel search strategies will be developed to aid the search for new phenomena not described by the Standard Model of particle physics. By combining insights from all three particle physics frontiers, this research aims to increase our understanding of fundamental particle physics.« less

A preliminary investigation on exercise intensities of gardening tasks in older adults.

PubMed

Park, Sin-Ae; Shoemaker, Candice A; Haub, Mark D

2008-12-01

Heart rate (HR) was measured continuously while men (n=6) and women (n=2) ages 71 to 85 years (M=77.4, SD=4.1) completed nine gardening tasks. HR and VO2 from a submaximal graded exercise test were used to estimate gardening VO2, energy expenditure, % HRmax, and metabolic equivalents (METs). Tasks were low to moderate intensity physical activity (1.6-3.6 METs); those which worked the upper and lower body were moderate intensity physical activity while those that worked primarily the upper body were low intensity physical activity.

Physical Strain and Work Ergonomics in Farmers with Disabilities.

PubMed

Nevala-Puranen, Nina; Sörensen, Lars

1997-01-01

In agriculture, occupational injuries are common, and several of them lead to permanent physical disability. The objective of this case study was to assess the strain and the ergonomic needs of four farmers (aged 34-49 years) with physical disabilities. A maximal bicycle ergometer test or an arm-crank test was done to assess their maximal heart rate (HR max ) and maximal oxygen consumption (V0 2max ). The strain at work was analyzed by measuring heart rate (HR), muscle activity (EMG), and the rating of perceived exertion (RPE). The farmers were interviewed as to possible and impossible work tasks and the ergonomic redesign measures taken to improve the work environment. The work tasks performed were mainly light or moderate work for the cardiorespiratory system according to mean HR (88-102 beats/min), the percentage of HR range (17-31% HRR), and the relative V0 2 (22-46% V0 2max ). The mean activity of the trapezius muscles was 0.4-9% of the maximal voluntary contraction (%MVC). All the participants had work tasks they were unable to perform. They had made ergonomie redesign changes mainly to the tractor. This case study showed that some agricultural work tasks were possible for farmers with physical disabilities and that the physical strain associated with these tasks was mainly light or moderate.

News Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

NASA Astrophysics Data System (ADS)

2011-01-01

Particle Physics: ATLAS unveils mural at CERN Prize: Corti Trust invites essay entries Astrophysics: CERN holds cosmic-ray conference Researchers in Residence: Lord Winston returns to school Music: ATLAS scientists record physics music Conference: Champagne flows at Reims event Competition: Students triumph at physics olympiad Teaching: Physics proves popular in Japanese schools Forthcoming Events

Physical load handling and listening comprehension effects on balance control.

PubMed

Qu, Xingda

2010-12-01

The purpose of this study was to determine the physical load handling and listening comprehension effects on balance control. A total of 16 young and 16 elderly participants were recruited in this study. The physical load handling task required holding a 5-kg load in each hand with arms at sides. The listening comprehension task involved attentive listening to a short conversation. Three short questions were asked regarding the conversation right after the testing trial to test the participants' attentiveness during the experiment. Balance control was assessed by centre of pressure-based measures, which were calculated from the force platform data when the participants were quietly standing upright on a force platform. Results from this study showed that both physical load handling and listening comprehension adversely affected balance control. Physical load handling had a more deleterious effect on balance control under the listening comprehension condition vs. no-listening comprehension condition. Based on the findings from this study, interventions for the improvement of balance could be focused on avoiding exposures to physically demanding tasks and cognitively demanding tasks simultaneously. STATEMENT OF RELEVANCE: Findings from this study can aid in better understanding how humans maintain balance, especially when physical and cognitive loads are applied. Such information is useful for developing interventions to prevent fall incidents and injuries in occupational settings and daily activities.

Physical characterization of aerosol particles during the Chinese New Year’s firework events

NASA Astrophysics Data System (ADS)

Zhang, Min; Wang, Xuemei; Chen, Jianmin; Cheng, Tiantao; Wang, Tao; Yang, Xin; Gong, Youguo; Geng, Fuhai; Chen, Changhong

2010-12-01

Measurements for particles 10 nm to 10 μm were taken using a Wide-range Particle Spectrometer during the Chinese New Year (CNY) celebrations in 2009 in Shanghai, China. These celebrations provided an opportunity to study the number concentration and size distribution of particles in an especial atmospheric pollution situation due to firework displays. The firework activities had a clear contribution to the number concentration of small accumulation mode particles (100-500 nm) and PM 1 mass concentration, with a maximum total number concentration of 3.8 × 10 4 cm -3. A clear shift of particles from nucleation and Aitken mode to small accumulation mode was observed at the peak of the CNY firework event, which can be explained by reduced atmospheric lifetimes of smaller particles via the concept of the coagulation sink. High particle density (2.7 g cm -3) was identified as being particularly characteristic of the firework aerosols. Recalculated fine particles PM 1 exhibited on average above 150 μg m -3 for more than 12 hours, which was a health risk to susceptible individuals. Integral physical parameters of firework aerosols were calculated for understanding their physical properties and further model simulation.

Design and Analysis of Self-Adapted Task Scheduling Strategies in Wireless Sensor Networks

PubMed Central

Guo, Wenzhong; Xiong, Naixue; Chao, Han-Chieh; Hussain, Sajid; Chen, Guolong

2011-01-01

In a wireless sensor network (WSN), the usage of resources is usually highly related to the execution of tasks which consume a certain amount of computing and communication bandwidth. Parallel processing among sensors is a promising solution to provide the demanded computation capacity in WSNs. Task allocation and scheduling is a typical problem in the area of high performance computing. Although task allocation and scheduling in wired processor networks has been well studied in the past, their counterparts for WSNs remain largely unexplored. Existing traditional high performance computing solutions cannot be directly implemented in WSNs due to the limitations of WSNs such as limited resource availability and the shared communication medium. In this paper, a self-adapted task scheduling strategy for WSNs is presented. First, a multi-agent-based architecture for WSNs is proposed and a mathematical model of dynamic alliance is constructed for the task allocation problem. Then an effective discrete particle swarm optimization (PSO) algorithm for the dynamic alliance (DPSO-DA) with a well-designed particle position code and fitness function is proposed. A mutation operator which can effectively improve the algorithm’s ability of global search and population diversity is also introduced in this algorithm. Finally, the simulation results show that the proposed solution can achieve significant better performance than other algorithms. PMID:22163971

Evaluation of the Military Functional Assessment Program: Inter rater Reliability of Task Scores

DTIC Science & Technology

2017-09-19

return-to-duty. Performance on the tasks is rated by a non-commissioned officer (NCO), occupational therapist, physical therapist, and mental health ...and additional ratings are provided on a subset of the tasks by an occupational therapist (OT), physical therapist (PT), and mental health (MH...3National Intrepid Center of Excellence United States Army Aeromedical Research Laboratory Aircrew Health and Performance Division September 2017

Deposition of aerosol particles in human lungs: in vivo measurements and modeling

EPA Science Inventory

The deposition dose and site of inhaled particles within the lung are the key determinants in health risk assessment of particulate pollutants. Accurate dose estimation, however, is a formidable task because aerosol transport and deposition in the lung are governed by many factor...

Characterizing physical properties and heterogeneous chemistry of single particles in air using optical trapping-Raman spectroscopy

NASA Astrophysics Data System (ADS)

Gong, Z.; Wang, C.; Pan, Y. L.; Videen, G.

2017-12-01

Heterogeneous reactions of solid particles in a gaseous environment are of increasing interest; however, most of the heterogeneous chemistry studies of airborne solids were conducted on particle ensembles. A close examination on the heterogeneous chemistry between single particles and gaseous-environment species is the key to elucidate the fundamental mechanisms of hydroscopic growth, cloud nuclei condensation, secondary aerosol formation, etc., and reduce the uncertainty of models in radiative forcing, climate change, and atmospheric chemistry. We demonstrate an optical trapping-Raman spectroscopy (OT-RS) system to study the heterogeneous chemistry of the solid particles in air at single-particle level. Compared to other single-particle techniques, optical trapping offers a non-invasive, flexible, and stable method to isolate single solid particle from substrates. Benefited from two counter-propagating hollow beams, the optical trapping configuration is adaptive to trap a variety of particles with different materials from inorganic substitution (carbon nanotubes, silica, etc.) to organic, dye-doped polymers and bioaerosols (spores, pollen, etc.), with different optical properties from transparent to strongly absorbing, with different sizes from sub-micrometers to tens of microns, or with distinct morphologies from loosely packed nanotubes to microspheres and irregular pollen grains. The particles in the optical trap may stay unchanged, surface degraded, or optically fragmented according to different laser intensity, and their physical and chemical properties are characterized by the Raman spectra and imaging system simultaneously. The Raman spectra is able to distinguish the chemical compositions of different particles, while the synchronized imaging system can resolve their physical properties (sizes, shapes, morphologies, etc.). The temporal behavior of the trapped particles also can be monitored by the OT-RS system at an indefinite time with a resolution from 10 ms to 5 min, which can be further applied to monitor the dynamics of heterogeneous reactions. The OT-RS system provides a flexible method to characterize and monitor the physical properties and heterogeneous chemistry of optically trapped solid particles in gaseous environment at single-particle level.

Particle Physics, 2nd Edition

NASA Astrophysics Data System (ADS)

Martin, B. R.; Shaw, G.

1998-01-01

Particle Physics, Second Edition is a concise and lucid account of the fundamental constituents of matter. The standard model of particle physics is developed carefully and systematically, without heavy mathematical formalism, to make this stimulating subject accessible to undergraduate students. Throughout, the emphasis is on the interpretation of experimental data in terms of the basic properties of quarks and leptons, and extensive use is made of symmetry principles and Feynman diagrams, which are introduced early in the book. The Second Edition brings the book fully up to date, including the discovery of the top quark and the search for the Higgs boson. A final short chapter is devoted to the continuing search for new physics beyond the standard model. Particle Physics, Second Edition features: * A carefully structured and written text to help students understand this exciting and demanding subject. * Many worked examples and problems to aid student learning. Hints for solving the problems are given in an Appendix. * Optional "starred" sections and appendices, containing more specialised and advanced material for the more ambitious reader.

Decoupling the Role of Inertia and Gravity on Particle Dispersion

NASA Technical Reports Server (NTRS)

Rogers, Chris; Squires, Kyle

1996-01-01

Turbulent gas flows laden with small, dense particles are encountered in a wide number of important applications in both industrial settings and aerodynamics applications. Particle interactions with the underlying turbulent flow are exceedingly complex and, consequently, difficult to accurately model. The difficulty arises primarily due to the fact that response of a particle to the local environment is dictated by turbulence properties in the reference frame moving with the particle (particle-Lagrangian). The particle-Lagrangian reference frame is in turn dependent upon the particle relaxation time (time constant) as well as gravitational drift. The combination of inertial and gravitational effects in this frame complicates our ability to accurately predict particle-laden flows since measurements in the particle-Lagrangian reference frame are difficult to obtain. Therefore, in this work we will examine separately the effects of inertia and gravitational drift on particle dispersion through a combination of physical and numerical experiments. In this study, particle-Lagrangian measurements will be obtained in physical experiments using stereo image velocimetry. Gravitational drift will be varied in the variable-g environments of the NASA DC-9 and in the zero-g environment at the drop tower at NASA-Lewis. Direct numerical simulations will be used to corroborate the measurements from the variable-g experiments. We expect that this work will generate new insight into the underlying physics of particle dispersion and will, in turn, lead to more accurate models of particle transport in turbulent flows.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quigg, C.

The author sketches some pressing questions in several active areas of particle physics and outline the challenges they present for the design and operation of detectors. His assignment at the 1999 ICFA Instrumentation School is to survey some current developments in particle physics, and to describe the kinds of experiments they would like to do in the near future and illustrate the demands their desires place on detectors and data analysis. Like any active science, particle physics is in a state of continual renewal. Many of the subjects that seem most fascinating and most promising today simply did not existmore » as recently as twenty-five years ago. Other topics that have preoccupied physicists for many years have been reshaped by recent discoveries and insights, and transformed by new techniques in accelerator science and detector technology. To provide some context for the courses and laboratories at this school, he has chosen three topics that are of high scientific interest, and that place very different demands on instrumental techniques. He hopes that you will begin to see the breadth of opportunities in particle physics, and that you will also look beyond the domain of particle physics for opportunities to apply the lessons you learn here in Istanbul.« less

A Web-Based Development Environment for Collaborative Data Analysis

NASA Astrophysics Data System (ADS)

Erdmann, M.; Fischer, R.; Glaser, C.; Klingebiel, D.; Komm, M.; Müller, G.; Rieger, M.; Steggemann, J.; Urban, M.; Winchen, T.

2014-06-01

Visual Physics Analysis (VISPA) is a web-based development environment addressing high energy and astroparticle physics. It covers the entire analysis spectrum from the design and validation phase to the execution of analyses and the visualization of results. VISPA provides a graphical steering of the analysis flow, which consists of self-written, re-usable Python and C++ modules for more demanding tasks. All common operating systems are supported since a standard internet browser is the only software requirement for users. Even access via mobile and touch-compatible devices is possible. In this contribution, we present the most recent developments of our web application concerning technical, state-of-the-art approaches as well as practical experiences. One of the key features is the use of workspaces, i.e. user-configurable connections to remote machines supplying resources and local file access. Thereby, workspaces enable the management of data, computing resources (e.g. remote clusters or computing grids), and additional software either centralized or individually. We further report on the results of an application with more than 100 third-year students using VISPA for their regular particle physics exercises during the winter term 2012/13. Besides the ambition to support and simplify the development cycle of physics analyses, new use cases such as fast, location-independent status queries, the validation of results, and the ability to share analyses within worldwide collaborations with a single click become conceivable.

Discrete Element Method and its application to materials failure problem on the example of Brazilian Test

NASA Astrophysics Data System (ADS)

Klejment, Piotr; Kosmala, Alicja; Foltyn, Natalia; Dębski, Wojciech

2017-04-01

The earthquake focus is the point where a rock under external stress starts to fracture. Understanding earthquake nucleation and earthquake dynamics requires thus understanding of fracturing of brittle materials. This, however, is a continuing problem and enduring challenge to geoscience. In spite of significant progress we still do not fully understand the failure of rock materials due to extreme stress concentration in natural condition. One of the reason of this situation is that information about natural or induced seismic events is still not sufficient for precise description of physical processes in seismic foci. One of the possibility of improving this situation is using numerical simulations - a powerful tool of contemporary physics. For this reason we used an advanced implementation of the Discrete Element Method (DEM). DEM's main task is to calculate physical properties of materials which are represented as an assembly of a great number of particles interacting with each other. We analyze the possibility of using DEM for describing materials during so called Brazilian Test. Brazilian Test is a testing method to obtain the tensile strength of brittle material. One of the primary reasons for conducting such simulations is to measure macroscopic parameters of the rock sample. We would like to report our efforts of describing the fracturing process during the Brazilian Test from the microscopic point of view and give an insight into physical processes preceding materials failure.

Experimental attempts to evoke a differential response to different stressors.

DOT National Transportation Integrated Search

1978-04-01

Ten paid male subjects each worked at a physical task with no competitive element (treadmill) and a competitive task ('Pong') with minimal physical activity. There were three work periods, each 50 min long. Ten minutes were allowed for rest and urine...

Particle transport and deposition: basic physics of particle kinetics.

PubMed

Tsuda, Akira; Henry, Frank S; Butler, James P

2013-10-01

The human body interacts with the environment in many different ways. The lungs interact with the external environment through breathing. The enormously large surface area of the lung with its extremely thin air-blood barrier is exposed to particles suspended in the inhaled air. The particle-lung interaction may cause deleterious effects on health if the inhaled pollutant aerosols are toxic. Conversely, this interaction can be beneficial for disease treatment if the inhaled particles are therapeutic aerosolized drugs. In either case, an accurate estimation of dose and sites of deposition in the respiratory tract is fundamental to understanding subsequent biological response, and the basic physics of particle motion and engineering knowledge needed to understand these subjects is the topic of this article. A large portion of this article deals with three fundamental areas necessary to the understanding of particle transport and deposition in the respiratory tract. These are: (i) the physical characteristics of particles, (ii) particle behavior in gas flow, and (iii) gas-flow patterns in the respiratory tract. Other areas, such as particle transport in the developing lung and in the diseased lung are also considered. The article concludes with a summary and a brief discussion of areas of future research. © 2013 American Physiological Society. Compr Physiol 3:1437-1471, 2013.

A pedagogical derivation of the matrix element method in particle physics data analysis

NASA Astrophysics Data System (ADS)

Sumowidagdo, Suharyo

2018-03-01

The matrix element method provides a direct connection between the underlying theory of particle physics processes and detector-level physical observables. I am presenting a pedagogically-oriented derivation of the matrix element method, drawing from elementary concepts in probability theory, statistics, and the process of experimental measurements. The level of treatment should be suitable for beginning research student in phenomenology and experimental high energy physics.

Instrumentation for Applied Physics and Industrial Applications

NASA Astrophysics Data System (ADS)

Hillemanns, H.; Le Goff, J.-M.

This document is part of Part 2 'Principles and Methods' of Subvolume B 'Detectors for Particles and Radiation' of Volume 21 'Elementary Particles' of Landolt-Börnstein - Group I 'Elementary Particles, Nuclei and Atoms'. It contains the Section '7.3 Instrumentation for Applied Physics and Industrial Applications' of Chapter '7 Applications of Detectors in Technology; Medicine and Other Fields' with the content:

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zieb, Kristofer James Ekhart; Hughes, Henry Grady III; Xu, X. George

The release of version 6.2 of the MCNP6 radiation transport code is imminent. To complement the newest release, a summary of the heavy charged particle physics models used in the 1 MeV to 1 GeV energy regime is presented. Several changes have been introduced into the charged particle physics models since the merger of the MCNP5 and MCNPX codes into MCNP6. Here, this article discusses the default models used in MCNP6 for continuous energy loss, energy straggling, and angular scattering of heavy charged particles. Explanations of the physics models’ theories are included as well.

Design evaluations for a flight cloud physics holocamera. [holographic/photographic camera for low-g Atmospheric Cloud Physics Laboratory

NASA Technical Reports Server (NTRS)

Moore, W. W., Jr.; Kurtz, R. L.; Lemons, J. F.

1976-01-01

The paper describes a holographic/photographic camera to be used with the zero-g or low-g Atmospheric Cloud Physics Laboratory. The flight prototype holocamera is intended to record particles from 0.01 to 5 microns for an optimum two-dimensional plane only in the microscopic photography mode, particles on a volume basis in the in-line holography mode from 5 microns up, and all particle sizes possible on a volume basis in the acute sideband holography mode.

Anti-gravity: The key to 21st century physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noyes, H.P.

1993-01-01

The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutation relations between position and velocity. Prior to this limit being pushed down to quantum effects, the lower bound is set by the available technology, but is otherwise scale invariant.more » Replacing force by force per unit mass and force per unit charge allows us to take over the Feynman-Dyson proof of the Maxwell Equations and extend it to weak gravity. The crossing symmetry of the individual scattering processes when one or more particles are replaced by anti-particles predicts both Coulomb attraction (for charged particles) and a Newtonian repulsion between any particle and its anti-particle. Previous quantum results remain intact, and predict the expected relativistic fine structure and spin dependencies. Experimental confirmation of this anti-gravity prediction would inaugurate the physics of the twenty-first century.« less

Anti-gravity: The key to 21st century physics

NASA Astrophysics Data System (ADS)

Noyes, H. P.

1993-01-01

The masses coupling constants and cosmological parameters obtained using our discrete and combinatorial physics based on discrimination between bit-strings indicate that we can achieve the unification of quantum mechanics with relativity which had become the goal of twentieth century physics. To broaden our case we show that limitations on measurement of the position and velocity of an individual massive particle observed in a colliding beam scattering experiment imply real, rational commutation relations between position and velocity. Prior to this limit being pushed down to quantum effects, the lower bound is set by the available technology, but is otherwise scale invariant. Replacing force by force per unit mass and force per unit charge allows us to take over the Feynman-Dyson proof of the Maxwell Equations and extend it to weak gravity. The crossing symmetry of the individual scattering processes when one or more particles are replaced by anti-particles predicts both Coulomb attraction (for charged particles) and a Newtonian repulsion between any particle and its anti-particle. Previous quantum results remain intact, and predict the expected relativistic fine structure and spin dependencies. Experimental confirmation of this anti-gravity prediction would inaugurate the physics of the twenty-first century.

In situ real-time measurement of physical characteristics of airborne bacterial particles

NASA Astrophysics Data System (ADS)

Jung, Jae Hee; Lee, Jung Eun

2013-12-01

Bioaerosols, including aerosolized bacteria, viruses, and fungi, are associated with public health and environmental problems. One promising control method to reduce the harmful effects of bioaerosols is thermal inactivation via a continuous-flow high-temperature short-time (HTST) system. However, variations in bioaerosol physical characteristics - for example, the particle size and shape - during the continuous-flow inactivation process can change the transport properties in the air, which can affect particle deposition in the human respiratory system or the filtration efficiency of ventilation systems. Real-time particle monitoring techniques are a desirable alternative to the time-consuming process of microscopic analysis that is conventionally used in sampling and particle characterization. Here, we report in situ real-time optical scattering measurements of the physical characteristics of airborne bacteria particles following an HTST process in a continuous-flow system. Our results demonstrate that the aerodynamic diameter of bacterial aerosols decreases when exposed to a high-temperature environment, and that the shape of the bacterial cells is significantly altered. These variations in physical characteristics using optical scattering measurements were found to be in agreement with the results of scanning electron microscopy analysis.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durham, M.D.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Durham, M.D.

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

Impulsive Approach Tendencies towards Physical Activity and Sedentary Behaviors, but Not Reflective Intentions, Prospectively Predict Non-Exercise Activity Thermogenesis

PubMed Central

Cheval, Boris; Sarrazin, Philippe; Pelletier, Luc

2014-01-01

Understanding the determinants of non-exercise activity thermogenesis (NEAT) is crucial, given its extensive health benefits. Some scholars have assumed that a proneness to react differently to environmental cues promoting sedentary versus active behaviors could be responsible for inter-individual differences in NEAT. In line with this reflection and grounded on the Reflective-Impulsive Model, we test the assumption that impulsive processes related to sedentary and physical activity behaviors can prospectively predict NEAT, operationalized as spontaneous effort exerted to maintain low intensity muscle contractions within the release phases of an intermittent maximal isometric contraction task. Participants (n = 91) completed a questionnaire assessing their intentions to adopt physical activity behaviors and a manikin task to assess impulsive approach tendencies towards physical activity behaviors (IAPA) and sedentary behaviors (IASB). Participants were then instructed to perform a maximal handgrip strength task and an intermittent maximal isometric contraction task. As hypothesized, multilevel regression analyses revealed that spontaneous effort was (a) positively predicted by IAPA, (b) negatively predicted by IASB, and (c) was not predicted by physical activity intentions, after controlling for some confounding variables such as age, sex, usual PA level and average force provided during the maximal-contraction phases of the task. These effects remained constant throughout all the phases of the task. This study demonstrated that impulsive processes may play a unique role in predicting spontaneous physical activity behaviors. Theoretically, this finding reinforces the utility of a motivational approach based on dual-process models to explain inter-individual differences in NEAT. Implications for health behavior theories and behavior change interventions are outlined. PMID:25526596

Impulsive approach tendencies towards physical activity and sedentary behaviors, but not reflective intentions, prospectively predict non-exercise activity thermogenesis.

PubMed

Cheval, Boris; Sarrazin, Philippe; Pelletier, Luc

2014-01-01

Understanding the determinants of non-exercise activity thermogenesis (NEAT) is crucial, given its extensive health benefits. Some scholars have assumed that a proneness to react differently to environmental cues promoting sedentary versus active behaviors could be responsible for inter-individual differences in NEAT. In line with this reflection and grounded on the Reflective-Impulsive Model, we test the assumption that impulsive processes related to sedentary and physical activity behaviors can prospectively predict NEAT, operationalized as spontaneous effort exerted to maintain low intensity muscle contractions within the release phases of an intermittent maximal isometric contraction task. Participants (n = 91) completed a questionnaire assessing their intentions to adopt physical activity behaviors and a manikin task to assess impulsive approach tendencies towards physical activity behaviors (IAPA) and sedentary behaviors (IASB). Participants were then instructed to perform a maximal handgrip strength task and an intermittent maximal isometric contraction task. As hypothesized, multilevel regression analyses revealed that spontaneous effort was (a) positively predicted by IAPA, (b) negatively predicted by IASB, and (c) was not predicted by physical activity intentions, after controlling for some confounding variables such as age, sex, usual PA level and average force provided during the maximal-contraction phases of the task. These effects remained constant throughout all the phases of the task. This study demonstrated that impulsive processes may play a unique role in predicting spontaneous physical activity behaviors. Theoretically, this finding reinforces the utility of a motivational approach based on dual-process models to explain inter-individual differences in NEAT. Implications for health behavior theories and behavior change interventions are outlined.

Recent advances in particle and droplet manipulation for lab-on-a-chip devices based on surface acoustic waves.

PubMed

Wang, Zhuochen; Zhe, Jiang

2011-04-07

Manipulation of microscale particles and fluid liquid droplets is an important task for lab-on-a-chip devices for numerous biological researches and applications, such as cell detection and tissue engineering. Particle manipulation techniques based on surface acoustic waves (SAWs) appear effective for lab-on-a-chip devices because they are non-invasive, compatible with soft lithography micromachining, have high energy density, and work for nearly any type of microscale particles. Here we review the most recent research and development of the past two years in SAW based particle and liquid droplet manipulation for lab-on-a-chip devices including particle focusing and separation, particle alignment and patterning, particle directing, and liquid droplet delivery.

Physics Accomplishments and Future Prospects of the BES Experiments at the Beijing Electron-Positron Collider

NASA Astrophysics Data System (ADS)

Briere, Roy A.; Harris, Frederick A.; Mitchell, Ryan E.

2016-10-01

The cornerstone of the Chinese experimental particle physics program is a series of experiments performed in the τ-charm energy region. China began building e+e- colliders at the Institute for High Energy Physics in Beijing more than three decades ago. Beijing Electron Spectrometer (BES) is the common root name for the particle physics detectors operated at these machines. We summarize the development of the BES program and highlight the physics results across several topical areas.

The combined fatigue effects of sequential exposure to seated whole body vibration and physical, mental, or concurrent work demands

PubMed Central

Lang, Angelica E.; Stobart, Jamie; Kociolek, Aaron M.; Milosavljevic, Stephan; Trask, Catherine

2017-01-01

Many occupations in agriculture, construction, transportation, and forestry are non-routine, involving non-cyclical tasks, both discretionary and non-discretionary work breaks, and a mix of work activities. Workers in these industries are exposed to seated whole body vibration (WBV) and tasks consisting of physical, mental, or a combination of demands. Risk assessment tools for non-routinized jobs have emerged but there remains a need to understand the combined effects of different work demands to improve risk assessment methods and ultimately inform ergonomists and workers on optimum work arrangement and scheduling strategies. The objective of this study was to investigate fatigue-related human responses of WBV sequentially combined with physical, mental, or concurrent physical and mental demands. Sixteen healthy participants performed four conditions on four separate days: (1) physically demanding work, (2) mentally demanding work, (3) concurrent work, and (4) control quiet sitting. For each condition, participants performed two 15-minute bouts of the experimental task, separated by 30-minutes of simulated WBV based on realistic all-terrain vehicle (ATV) riding data. A test battery of fatigue measures consisting of biomechanical, physiological, cognitive, and sensorimotor measurements were collected at four interval periods: pre-session, after the first bout of the experimental task and before WBV, after WBV and before the second bout of the experimental task, and post-session. Nine measures demonstrated statistically significant time effects during the control condition; 11, 7, and 12 measures were significant in the physical, mental, and concurrent conditions, respectively. Overall, the effects of seated WBV in combination with different tasks are not additive but possibly synergistic or antagonistic. There appears to be a beneficial effect of seated ATV operation as a means of increasing task variation; but since excessive WBV may independently pose a health risk in the longer-term, these beneficial results may not be sensible as a long-term solution. PMID:29236752

The combined fatigue effects of sequential exposure to seated whole body vibration and physical, mental, or concurrent work demands.

PubMed

Yung, Marcus; Lang, Angelica E; Stobart, Jamie; Kociolek, Aaron M; Milosavljevic, Stephan; Trask, Catherine

2017-01-01

Many occupations in agriculture, construction, transportation, and forestry are non-routine, involving non-cyclical tasks, both discretionary and non-discretionary work breaks, and a mix of work activities. Workers in these industries are exposed to seated whole body vibration (WBV) and tasks consisting of physical, mental, or a combination of demands. Risk assessment tools for non-routinized jobs have emerged but there remains a need to understand the combined effects of different work demands to improve risk assessment methods and ultimately inform ergonomists and workers on optimum work arrangement and scheduling strategies. The objective of this study was to investigate fatigue-related human responses of WBV sequentially combined with physical, mental, or concurrent physical and mental demands. Sixteen healthy participants performed four conditions on four separate days: (1) physically demanding work, (2) mentally demanding work, (3) concurrent work, and (4) control quiet sitting. For each condition, participants performed two 15-minute bouts of the experimental task, separated by 30-minutes of simulated WBV based on realistic all-terrain vehicle (ATV) riding data. A test battery of fatigue measures consisting of biomechanical, physiological, cognitive, and sensorimotor measurements were collected at four interval periods: pre-session, after the first bout of the experimental task and before WBV, after WBV and before the second bout of the experimental task, and post-session. Nine measures demonstrated statistically significant time effects during the control condition; 11, 7, and 12 measures were significant in the physical, mental, and concurrent conditions, respectively. Overall, the effects of seated WBV in combination with different tasks are not additive but possibly synergistic or antagonistic. There appears to be a beneficial effect of seated ATV operation as a means of increasing task variation; but since excessive WBV may independently pose a health risk in the longer-term, these beneficial results may not be sensible as a long-term solution.

Localizing Pain Matrix and Theory of Mind networks with both verbal and non-verbal stimuli.

PubMed

Jacoby, Nir; Bruneau, Emile; Koster-Hale, Jorie; Saxe, Rebecca

2016-02-01

Functional localizer tasks allow researchers to identify brain regions in each individual's brain, using a combination of anatomical and functional constraints. In this study, we compare three social cognitive localizer tasks, designed to efficiently identify regions in the "Pain Matrix," recruited in response to a person's physical pain, and the "Theory of Mind network," recruited in response to a person's mental states (i.e. beliefs and emotions). Participants performed three tasks: first, the verbal false-belief stories task; second, a verbal task including stories describing physical pain versus emotional suffering; and third, passively viewing a non-verbal animated movie, which included segments depicting physical pain and beliefs and emotions. All three localizers were efficient in identifying replicable, stable networks in individual subjects. The consistency across tasks makes all three tasks viable localizers. Nevertheless, there were small reliable differences in the location of the regions and the pattern of activity within regions, hinting at more specific representations. The new localizers go beyond those currently available: first, they simultaneously identify two functional networks with no additional scan time, and second, the non-verbal task extends the populations in whom functional localizers can be applied. These localizers will be made publicly available. Copyright © 2015 Elsevier Inc. All rights reserved.

Close-out report with links to abstracts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marmar, Earl S.

This grant provided A/V support for two technical meetings of the Edge Coordinating Committee: (1) Nov 13, 2013 (co-located with the APS-DPP meeting in Denver, CO) https://ecc.mit.edu/fall-2013-technical-meeting#overlay-context=ecc-meetings; (2) April 28-May 1, 2015 (embedded sessions in the Transport Task Force Meeting, Salem, MA) http://www-internal.psfc.mit.edu/TTF2015/index.html. The ultimate goal of the U.S. Transport Task Force is to develop a physics-based understanding of particle, momentum and heat transport in magnetic fusion devices. This understanding should be of sufficient depth that it allows the development of predictive models of plasma transport that can be validated against experiment, and then used to anticipate the future performancemore » of burning plasmas in ITER, as well as to provide guidance for the design of next-step fusion nuclear science facilities. To achieve success in transport science, it is essential to characterize local fluctuations and transport in toroidal plasmas, to understand the basic mechanisms responsible for transport, and ultimately to control these transport processes. These goals must be pursued in multiple areas, and these topics evolve in order to reflect current interests.« less

ACTS: from ATLAS software towards a common track reconstruction software

NASA Astrophysics Data System (ADS)

Gumpert, C.; Salzburger, A.; Kiehn, M.; Hrdinka, J.; Calace, N.; ATLAS Collaboration

2017-10-01

Reconstruction of charged particles’ trajectories is a crucial task for most particle physics experiments. The high instantaneous luminosity achieved at the LHC leads to a high number of proton-proton collisions per bunch crossing, which has put the track reconstruction software of the LHC experiments through a thorough test. Preserving track reconstruction performance under increasingly difficult experimental conditions, while keeping the usage of computational resources at a reasonable level, is an inherent problem for many HEP experiments. Exploiting concurrent algorithms and using multivariate techniques for track identification are the primary strategies to achieve that goal. Starting from current ATLAS software, the ACTS project aims to encapsulate track reconstruction software into a generic, framework- and experiment-independent software package. It provides a set of high-level algorithms and data structures for performing track reconstruction tasks as well as fast track simulation. The software is developed with special emphasis on thread-safety to support parallel execution of the code and data structures are optimised for vectorisation to speed up linear algebra operations. The implementation is agnostic to the details of the detection technologies and magnetic field configuration which makes it applicable to many different experiments.

Particle Sorting and Motility Out of Equilibrium

NASA Astrophysics Data System (ADS)

Sandford, Cato

The theory of equilibrium statistical physics, formulated over a century ago, provides an excellent description of physical systems which have reached a static, relaxed state. Such systems can be loosely thought of as maximally disordered, in keeping with the Second Law of Thermodynamics which states that a thermal system in equilibrium has reached a state of highest entropy. However, many entities in the world around us maintain themselves in an remarkably ordered and dynamic state, and must pay for this by producing entropy in their surroundings. Organisms, for example, convert chemical energy (food) into heat, which is then dumped into the environment, raising its entropy. Systems which produce entropy through any mechanism must be described by theories of non-equilibrium statistical physics, for which there currently exists no unified framework or ontology. Here we examine two specific cases of non-equilibrium phenomena from a theoretical perspective. First, we explore the behaviour of microscopic particles which continually dissipate energy to propel themselves through their environment. Second, we consider how devices which distinguish between different types of particles can exploit non-equilibrium processes to enhance their performance. For the case of self-propelled particles, we consider a theoretical model where the particle's propulsion force has "memory"--it is a random process whose instantaneous value depends on its past evolution. This introduces a persistence in the particle's motion, and requires the dissipation of energy into its surroundings. These particles are found to exhibit a variety of behaviours forbidden in equilibrium systems: for instance they may cluster around barriers, exert unbalanced forces, and sustain steady flows through space. We develop the understanding of these particles' dynamics through a combination of explicit calculations, approximations and numerical simulation which characterise and quantify their non-equilibrium behaviour. The second situation investigated concerns the physics of particle-sorting, which is fundamental to biological systems. We introduce a number of model devices designed to distinguish between and segregate two species of particles, and analyse how the quality and speed of their operation may be influenced by providing them with an energy source which pushes them out of equilibrium. We identify different physical regimes, where our devices may consume energy to deliver better results or deliver them faster or both; and we furthermore connect the broader theory of particle sorting to the fundamental theoretical framework of statistical physics.

Executive function in rats is impaired by low (20 cGy) doses of 1 GeV/u (56)Fe particles.

PubMed

Lonart, György; Parris, Brian; Johnson, Angela M; Miles, Scott; Sanford, Larry D; Singletary, Sylvia J; Britten, Richard A

2012-10-01

Exposure to galactic cosmic radiation is a potential health risk in long-term space travel and represents a significant risk to the central nervous system. The most harmful component of galactic cosmic radiation is the HZE [high mass, highly charged (Z), high energy] particles, e.g., (56)Fe particle. In previous ground-based experiments, exposure to doses of HZE-particle radiation that an astronaut will receive on a deep space mission (i.e., ∼20 cGy) resulted in pronounced deficits in hippocampus-dependent learning and memory in rodents. Neurocognitive tasks that are dependent upon other regions of the brain, such as the striatum, are also impaired after exposure to low HZE-particle doses. These data raise the possibility that neurocognitive tasks regulated by the prefrontal cortex could also be impaired after exposure to mission relevant HZE-particle doses, which may prevent astronauts from performing complex executive functions. To assess the effects of mission relevant (20 cGy) doses of 1 GeV/u (56)Fe particles on executive function, male Wistar rats received either sham treatment or were irradiated and tested 3 months later for their ability to perform attentional set shifting. Compared to the controls, rats that received 20 cGy of 1 GeV/u (56)Fe particles showed significant impairments in their ability to complete the attentional set-shifting test, with only 17% of irradiated rats completing all stages as opposed to 78% of the control rats. The majority of failures (60%) occurred at the first reversal stage, and half of the remaining animals failed at the extra-dimensional shift phase of the studies. The irradiated rats that managed to complete the tasks did so with approximately the same ease as did the control rats. These observations suggest that exposure to mission relevant doses of 1 GeV/u (56)Fe particles results in the loss of functionality in several regions of the cortex: medical prefrontal cortex, anterior cingulated cortex, posterior cingulated cortex and the basal forebrain. Our observation that 20 cGy of 1 GeV/u (56)Fe particles is sufficient to impair the ability of rats to conduct attentional set-shifting raises the possibility that astronauts on prolonged deep space exploratory missions could subsequently develop deficits in executive function.

Theoretical physics: Quarks fuse to release energy

NASA Astrophysics Data System (ADS)

Miller, Gerald A.

2017-11-01

In nuclear fusion, energy is produced by the rearrangement of protons and neutrons. The discovery of an analogue of this process involving particles called quarks has implications for both nuclear and particle physics. See Letter p.89

Adding sleep restriction to the equation: impact on wildland firefighters' work performance and physiology in hot conditions.

PubMed

Vincent, Grace E; Ferguson, Sally; Larsen, Brianna; Ridgers, Nicola D; Snow, Rod; Aisbett, Brad

2018-04-06

To examine the effects of sleep restriction on firefighters' physical task performance, physical activity, and physiological and perceived exertion during simulated hot wildfire conditions. 31 firefighters were randomly allocated to either the hot (n = 18, HOT; 33 °C, 8-h sleep opportunity) or hot and sleep restricted (n = 13, HOT + SR; 33 °C, 4-h sleep opportunity) condition. Intermittent, self-paced work circuits of six firefighting tasks were performed for 3 days. Firefighters self-reported ratings of perceived exertion. Heart rate, core temperature, and physical activity were measured continuously. Fluids were consumed ad libitum, and all food and fluids consumed were recorded. Urine volume and urine specific gravity (USG) were analysed and sleep was assessed using polysomnography (PSG). There were no differences between the HOT and HOT + SR groups in firefighters' physical task performance, heart rate, core temperature, USG, or fluid intake. Ratings of perceived exertion were higher (p < 0.05) in the HOT + SR group for two of the six firefighting tasks. The HOT group spent approximately 7 min more undertaking moderate physical activity throughout the 2-h work circuits compared to the HOT + SR group. Two nights of sleep restriction did not influence firefighters' physical task performance or physiological responses during 3 days of simulated wildfire suppression. Further research is needed to explore firefighters' pacing strategies during real wildfire suppression.

Phase-factor-dependent symmetries and quantum phases in a three-level cavity QED system.

PubMed

Fan, Jingtao; Yu, Lixian; Chen, Gang; Jia, Suotang

2016-05-03

Unlike conventional two-level particles, three-level particles may support some unitary-invariant phase factors when they interact coherently with a single-mode quantized light field. To gain a better understanding of light-matter interaction, it is thus necessary to explore the phase-factor-dependent physics in such a system. In this report, we consider the collective interaction between degenerate V-type three-level particles and a single-mode quantized light field, whose different components are labeled by different phase factors. We mainly establish an important relation between the phase factors and the symmetry or symmetry-broken physics. Specifically, we find that the phase factors affect dramatically the system symmetry. When these symmetries are breaking separately, rich quantum phases emerge. Finally, we propose a possible scheme to experimentally probe the predicted physics of our model. Our work provides a way to explore phase-factor-induced nontrivial physics by introducing additional particle levels.

A Bubble Chamber Simulator: A New Tool for the Physics Classroom

ERIC Educational Resources Information Center

Gagnon, Michel

2011-01-01

Mainly used in the 1960s, bubble chambers played a major role in particle physics. Now replaced with modern electronic detectors, we believe they remain an important didactic tool to introduce particle physics as they provide visual, appealing and insightful pictures. Sadly, this rare type of detector is mostly accessible through open-door events…

Donald Glaser, the Bubble Chamber, and Elementary Particles

Science.gov Websites

Effects of Ionizing Radiation on the Formation of Bubbles in Liquids Physical Review, Vol. 87, Issue 4 , 665, August 15, 1952 Characteristics of Bubble Chambers Physical Review, Vol. 97, Issue 2, 474-479 Chambers Physical Review, Vol. 102, Issue 6, 1653-1658, June 15, 1956 Methods of Particle Detection for

Hands on CERN: A Well-Used Physics Education Project

ERIC Educational Resources Information Center

Johansson, K. E.

2006-01-01

The "Hands on CERN" education project makes it possible for students and teachers to get close to the forefront of scientific research. The project confronts the students with contemporary physics at its most fundamental level with the help of particle collisions from the DELPHI particle physics experiment at CERN. It now exists in 14 languages…

Fast Inference of Deep Neural Networks in FPGAs for Particle Physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Duarte, Javier; Han, Song; Harris, Philip

Recent results at the Large Hadron Collider (LHC) have pointed to enhanced physics capabilities through the improvement of the real-time event processing techniques. Machine learning methods are ubiquitous and have proven to be very powerful in LHC physics, and particle physics as a whole. However, exploration of the use of such techniques in low-latency, low-power FPGA hardware has only just begun. FPGA-based trigger and data acquisition (DAQ) systems have extremely low, sub-microsecond latency requirements that are unique to particle physics. We present a case study for neural network inference in FPGAs focusing on a classifier for jet substructure which wouldmore » enable, among many other physics scenarios, searches for new dark sector particles and novel measurements of the Higgs boson. While we focus on a specific example, the lessons are far-reaching. We develop a package based on High-Level Synthesis (HLS) called hls4ml to build machine learning models in FPGAs. The use of HLS increases accessibility across a broad user community and allows for a drastic decrease in firmware development time. We map out FPGA resource usage and latency versus neural network hyperparameters to identify the problems in particle physics that would benefit from performing neural network inference with FPGAs. For our example jet substructure model, we fit well within the available resources of modern FPGAs with a latency on the scale of 100 ns.« less

Prediction of enjoyment in school physical education.

PubMed

Gråstén, Arto; Jaakkola, Timo; Liukkonen, Jarmo; Watt, Anthony; Yli-Piipari, Sami

2012-01-01

The specific aim of this study was to examine whether motivational climate, perceived physical competence, and exercise motivation predict enjoyment in school physical education within the same sample of adolescents across three years of secondary school. A sample of 639 students (girls = 296, boys = 343) aged between 13- to 15-years at the commencement of the study completed the Intrinsic Motivation Climate in Physical Education Questionnaire, Physical Self-Perception Profile, Physical Education Motivation Scale, and Physical Education Enjoyment Scale. Results derived from path analyses indicated that task-involving motivational climate predicted enjoyment in physical education via perceived physical competence and intrinsic motivation in both girls and boys. In particular, these results supported previous findings of Vallerand et. al (1997) with the self-determination theory and the achievement goal theory. Ego-involving climate was not a significant predictor either in girls or boys. The current results provide continuing support for the investigation of Vallerand's model in the physical education setting, and highlight that motivational climate is an area that requires further evaluation as a contributing factor in the improvement of physical education teaching. A better understanding of the role of motivational climate may assist efforts to promote children's and adolescents' perceived physical competence, intrinsic motivation, and enjoyment in the school physical education setting. Key pointsThe findings of the current study support existing suggestions of Vallerand's (1997) model in which social factors mediated by a psychological mediator, and exercise motivation are related to positive consequences in the PE context.Task-involving motivational climate predicted PE enjoyment via perceived physical competence and intrinsic motivation with both girls and boys. Task-involving motivational climate in PE lessons at Grade 7 had a strong association with PE enjoyment via perceived physical competence and intrinsic motivation at Grade 9 for both girls and boys.Ego-involving climate did not fit either the data for the girls or boys, as PE lessons based on ego-involving motivational climate did not significantly influence on the level of PE enjoyment.The results of the current study and previous practical findings support task-involving teaching methods to promote adolescent's PE enjoyment through secondary school years. School PE could be most effective if based on task-involving motivational climate, in which the main objective is increasing students' perceived physical competence, intrinsic motivation, and enjoyment.

United States Army physical readiness training: rationale and evaluation of the physical training doctrine.

PubMed

Knapik, Joseph J; Rieger, William; Palkoska, Frank; Van Camp, Steven; Darakjy, Salima

2009-07-01

This paper reviews the rationale and evaluations of Physical Readiness Training (PRT), the new U.S. Army physical training doctrine designed to improve soldiers' physical capability for military operations. The purposes of PRT are to improve physical fitness, prevent injuries, progressively train soldiers, and develop soldiers' self-confidence and discipline. The PRT follows the principles of progressive overload, regularity, specificity, precision, variety, and balance. Specificity was achieved by examining the standard list of military (warrior) tasks and determining 1) the physical requirements, 2) the fitness components involved, and 3) the training activities that most likely could improve the military tasks. Injury-prevention features include reduced running mileage, exercise variety (cross-training), and gradual, progressive training. In 3 military field studies, the overall adjusted risk of injury was 1.5-1.8 times higher in groups of soldiers performing traditional military physical training programs when compared with groups using a PRT program. Scores on the Army Physical Fitness Test were similar or higher in groups using PRT programs. In an 8-week laboratory study comparing PRT with a weightlifting/running program, both programs resulted in major improvements in militarily relevant tasks (e.g., 3.2-km walk/run with 32-kg load, 400-m run with 18-kg load, 5- to 30-second rushes to and from prone position, 80-kg casualty drag, obstacle course). When compared with traditional military physical training programs, PRT consistently resulted in fewer injuries and in equal or greater improvements in fitness and military task performance.

Explaining physical activity levels from a self-efficacy perspective: the physical activity counseling trial.

PubMed

Blanchard, Chris M; Fortier, Michelle; Sweet, Shane; O'Sullivan, Tracey; Hogg, William; Reid, Robert D; Sigal, Ronald J

2007-01-01

The Physical Activity Counseling (PAC) trial compared the effects of a 13-week primary care physical activity (PA) intervention that incorporated a PA counselor into a health care practice compared to a control condition on PA over a 25-week period and showed group differences in PA were present at 6 and 13 weeks. The main purpose was to examine the mediating effect of 6-week task and barrier self-efficacy on the intervention versus control group/13-week PA relationships. A secondary purpose was to determine whether task and barrier self-efficacy were significantly related to PA throughout the trial for both groups. Participants were primarily sedentary individuals who received a 2- to 4-min PA intervention from their primary care provider, after which they were randomly assigned to the intervention (n = 61) or control condition (n = 59). Self-reported PA and task (barrier) self-efficacy measures were obtained during (i.e., baseline, 6 and 13 weeks) and after (i.e., 19 and 25 weeks) the intervention in both groups. Six-week task and barrier self-efficacy had a small mediating effect. Furthermore, barrier self-efficacy had a significant relationship with PA throughout the trial, whereas the relationship between task self-efficacy and PA became significantly weaker as the trial progressed. PAC interventions among primarily sedentary individuals should be partly based on barrier and task self-efficacy. However, the stability of the task self-efficacy/PA relationship needs further examination.

Perceptions of Middle School Assessment: An Ecological View

ERIC Educational Resources Information Center

James, Alisa R.; Griffin, Linda; Dodds, Patt

2009-01-01

Background: The ecology of physical education is created through the interaction of three task systems: managerial task system, instructional task system, and the student social system. Within the ecological framework tasks are presented and task development is influenced by concepts such as ambiguity, risk, and accountability. Teachers' and…

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

PubMed

Li, Xuejun; Xu, Jia; Yang, Yun

2015-01-01

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

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

PubMed Central

Li, Xuejun; Xu, Jia; Yang, Yun

2015-01-01

Cloud workflow system is a kind of platform service based on cloud computing. It facilitates the automation of workflow applications. Between cloud workflow system and its counterparts, market-oriented business model is one of the most prominent factors. The optimization of task-level scheduling in cloud workflow system is a hot topic. As the scheduling is a NP problem, Ant Colony Optimization (ACO) and Particle Swarm Optimization (PSO) have been proposed to optimize the cost. However, they have the characteristic of premature convergence in optimization process and therefore cannot effectively reduce the cost. To solve these problems, Chaotic Particle Swarm Optimization (CPSO) algorithm with chaotic sequence and adaptive inertia weight factor is applied to present the task-level scheduling. Chaotic sequence with high randomness improves the diversity of solutions, and its regularity assures a good global convergence. Adaptive inertia weight factor depends on the estimate value of cost. It makes the scheduling avoid premature convergence by properly balancing between global and local exploration. The experimental simulation shows that the cost obtained by our scheduling is always lower than the other two representative counterparts. PMID:26357510

Estimation of snow in extratropical cyclones from multiple frequency airborne radar observations. An Expectation-Maximization approach

NASA Astrophysics Data System (ADS)

Grecu, M.; Tian, L.; Heymsfield, G. M.

2017-12-01

A major challenge in deriving accurate estimates of physical properties of falling snow particles from single frequency space- or airborne radar observations is that snow particles exhibit a large variety of shapes and their electromagnetic scattering characteristics are highly dependent on these shapes. Triple frequency (Ku-Ka-W) radar observations are expected to facilitate the derivation of more accurate snow estimates because specific snow particle shapes tend to have specific signatures in the associated two-dimensional dual-reflectivity-ratio (DFR) space. However, the derivation of accurate snow estimates from triple frequency radar observations is by no means a trivial task. This is because the radar observations can be subject to non-negligible attenuation (especially at W-band when super-cooled water is present), which may significantly impact the interpretation of the information in the DFR space. Moreover, the electromagnetic scattering properties of snow particles are computationally expensive to derive, which makes the derivation of reliable parameterizations usable in estimation methodologies challenging. In this study, we formulate an two-step Expectation Maximization (EM) methodology to derive accurate snow estimates in Extratropical Cyclones (ECTs) from triple frequency airborne radar observations. The Expectation (E) step consists of a least-squares triple frequency estimation procedure applied with given assumptions regarding the relationships between the density of snow particles and their sizes, while the Maximization (M) step consists of the optimization of the assumptions used in step E. The electromagnetic scattering properties of snow particles are derived using the Rayleigh-Gans approximation. The methodology is applied to triple frequency radar observations collected during the Olympic Mountains Experiment (OLYMPEX). Results show that snowfall estimates above the freezing level in ETCs consistent with the triple frequency radar observations as well as with independent rainfall estimates below the freezing level may be derived using the EM methodology formulated in the study.

Self-Control Strength Depletion Reduces Self-Efficacy and Impairs Exercise Performance.

PubMed

Graham, Jeffrey D; Bray, Steven R

2015-10-01

The purpose of this study was to investigate the role of task self-efficacy as a psychological factor involved in the relationship between self-control depletion and physical endurance. Participants (N = 37) completed two isometric handgrip endurance trials, separated by a Stroop task, which was either congruent (control) or incongruent (causing depletion). Task self-efficacy for the second endurance trial was measured following the Stroop task. Participants in the depletion condition reported lower task self-efficacy and showed a greater reduction in performance on the second endurance trial when compared with controls. Task self-efficacy also mediated the relationship between self-control depletion and endurance performance. The results of this study provide evidence that task self-efficacy is negatively affected following self-control depletion. We recommend that task self-efficacy be further investigated as a psychological factor accounting for the negative change in self-control performance of physical endurance and sport tasks following self-control strength depletion.

Neutrinos and dark matter in the Black Hills

NASA Astrophysics Data System (ADS)

McMahan Norris, Margaret; Sayler, Bentley

2010-02-01

Where in the U.S. could you walk into a hardware store and be asked about neutrinos? It happens regularly in the Black Hills of South Dakota, where preliminary design is in progress for the Deep Underground Science and Engineering Laboratory (DUSEL), a planned NSF Major Research Experimental Facility Construction (MREFC) initiative to be located at the former Homestake gold mine in Lead, SD. DUSEL has physicists buzzing too, as the particle, astro-, and nuclear physics communities have all identified the need for a new laboratory deep beneath the Earth's surface to address some of the most compelling, transformational science at the frontiers of their disciplines. Elusive particles such as neutrinos and WIMPS (a possible candidate for dark matter) -- though they spark the imagination - are equally elusive when trying to explain to students and the public. That will be the task of the Sanford Center for Science Education, planned to be the education arm of DUSEL. Early prototypes of future programs at the education center are now under development, ranging from professional development for teachers to classroom tours to working with American Indian educators. These programs, which are building capacity for the future education center, will be discussed. )

Nanostructured organosilicon luminophores and their application in highly efficient plastic scintillators

NASA Astrophysics Data System (ADS)

Ponomarenko, Sergei A.; Surin, Nikolay M.; Borshchev, Oleg V.; Luponosov, Yuriy N.; Akimov, Dmitry Y.; Alexandrov, Ivan S.; Burenkov, Alexander A.; Kovalenko, Alexey G.; Stekhanov, Viktor N.; Kleymyuk, Elena A.; Gritsenko, Oleg T.; Cherkaev, Georgiy V.; Kechek'yan, Alexander S.; Serenko, Olga A.; Muzafarov, Aziz M.

2014-10-01

Organic luminophores are widely used in various optoelectronic devices, which serve for photonics, nuclear and particle physics, quantum electronics, medical diagnostics and many other fields of science and technology. Improving their spectral-luminescent characteristics for particular technical requirements of the devices is a challenging task. Here we show a new concept to universal solution of this problem by creation of nanostructured organosilicon luminophores (NOLs), which are a particular type of dendritic molecular antennas. They combine the best properties of organic luminophores and inorganic quantum dots: high absorption cross-section, excellent photoluminescence quantum yield, fast luminescence decay time and good processability. A NOL consists of two types of covalently bonded via silicon atoms organic luminophores with efficient Förster energy transfer between them. Using NOLs in plastic scintillators, widely utilized for radiation detection and in elementary particles discoveries, led to a breakthrough in their efficiency, which combines both high light output and fast decay time. Moreover, for the first time plastic scintillators, which emit light in the desired wavelength region ranging from 370 to 700 nm, have been created. We anticipate further applications of NOLs as working elements of pulsed dye lasers in photonics, optoelectronics and as fluorescent labels in biology and medical diagnostics.

Quantum Metropolis sampling.

PubMed

Temme, K; Osborne, T J; Vollbrecht, K G; Poulin, D; Verstraete, F

2011-03-03

The original motivation to build a quantum computer came from Feynman, who imagined a machine capable of simulating generic quantum mechanical systems--a task that is believed to be intractable for classical computers. Such a machine could have far-reaching applications in the simulation of many-body quantum physics in condensed-matter, chemical and high-energy systems. Part of Feynman's challenge was met by Lloyd, who showed how to approximately decompose the time evolution operator of interacting quantum particles into a short sequence of elementary gates, suitable for operation on a quantum computer. However, this left open the problem of how to simulate the equilibrium and static properties of quantum systems. This requires the preparation of ground and Gibbs states on a quantum computer. For classical systems, this problem is solved by the ubiquitous Metropolis algorithm, a method that has basically acquired a monopoly on the simulation of interacting particles. Here we demonstrate how to implement a quantum version of the Metropolis algorithm. This algorithm permits sampling directly from the eigenstates of the Hamiltonian, and thus evades the sign problem present in classical simulations. A small-scale implementation of this algorithm should be achievable with today's technology.

Annual modulation experiments, galactic models and WIMPs

NASA Astrophysics Data System (ADS)

Hudson, Robert G.

Our task in the paper is to examine some recent experiments (in the period 1996-2002) bearing on the issue of whether there is dark matter in the universe in the form of neutralino WIMPs (weakly interacting massive particles). Our main focus is an experiment performed by the DAMA group that claims to have found an 'annual modulation signature' for the WIMP. DAMA's result has been hotly contested by two other groups, EDELWEISS and CDMS, and we study the details of the experiments performed by all three groups. Our goal is to investigate the philosophic and sociological implications of this controversy. Particularly, using an innovative theoretical strategy suggested by (Copi, C. and L. M. Krauss (2003). Comparing interaction rate detectors for weakly interacting massive particles with annual modulation detectors. Physical Review D, 67, 103 507), we suggest a new way of resolving discordant experimental data (extending a previous analysis by (Franklin, A. (2002). Selectivity and discord. Pittsburgh: University of Pittsburgh Press). In addition, we are in a position to contribute substantively to the debate between realists and constructive empiricists. Finally, from a sociological standpoint, we remark that DAMA's work has been valuable in mobilizing other research teams and providing them with a critical focus.

Practice makes perfect: familiarity of task determines success in solvable tasks for free-ranging dogs (Canis lupus familiaris).

PubMed

Bhattacharjee, Debottam; Dasgupta, Sandipan; Biswas, Arpita; Deheria, Jayshree; Gupta, Shreya; Nikhil Dev, N; Udell, Monique; Bhadra, Anindita

2017-07-01

Domestic dogs' (Canis lupus familiaris) socio-cognitive faculties have made them highly sensitive to human social cues. While dogs often excel at understanding human communicative gestures, they perform comparatively poorly in problem-solving and physical reasoning tasks. This difference in their behaviour could be due to the lifestyle and intense socialization, where problem solving and physical cognition are less important than social cognition. Free-ranging dogs live in human-dominated environments, not under human supervision and are less socialized. Being scavengers, they often encounter challenges where problem solving is required in order to get access to food. We tested Indian street dogs in familiar and unfamiliar independent solvable tasks and quantified their persistence and dependence on a novel human experimenter, in addition to their success in solving a task. Our results indicate that free-ranging dogs succeeded and persisted more in the familiar task as compared to the unfamiliar one. They showed negligible amount of human dependence in the familiar task, but showed prolonged gazing and considerable begging behaviour to the human experimenter in the context of the unfamiliar task. Cognitive abilities of free-ranging dogs thus play a pivotal role in determining task-associated behaviours based on familiarity. In addition to that, these dogs inherently tend to socialize with and depend on humans, even if they are strangers. Our results also illustrate free-ranging dogs' low competence at physical cognitive tasks.

The Multiverse and Particle Physics

NASA Astrophysics Data System (ADS)

Donoghue, John F.

2016-10-01

The possibility of fundamental theories with very many ground states, each with different physical parameters, changes the way that we approach the major questions of particle physics. Most importantly, it raises the possibility that these different parameters could be realized in different domains in the larger universe. In this review, I survey the motivations for the multiverse and the impact of the idea of the multiverse on the search for new physics beyond the Standard Model.

Scaling effects in direct shear tests

USGS Publications Warehouse

Orlando, A.D.; Hanes, D.M.; Shen, H.H.

2009-01-01

Laboratory experiments of the direct shear test were performed on spherical particles of different materials and diameters. Results of the bulk friction vs. non-dimensional shear displacement are presented as a function of the non-dimensional particle diameter. Simulations of the direct shear test were performed using the Discrete Element Method (DEM). The simulation results show Considerable differences with the physical experiments. Particle level material properties, such as the coefficients of static friction, restitution and rolling friction need to be known a priori in order to guarantee that the simulation results are an accurate representation of the physical phenomenon. Furthermore, laboratory results show a clear size dependency on the results, with smaller particles having a higher bulk friction than larger ones. ?? 2009 American Institute of Physics.

Comparisons of physical experiment and discrete element simulations of sheared granular materials in an annular shear cell

USGS Publications Warehouse

Ji, S.; Hanes, D.M.; Shen, H.H.

2009-01-01

In this study, we report a direct comparison between a physical test and a computer simulation of rapidly sheared granular materials. An annular shear cell experiment was conducted. All parameters were kept the same between the physical and the computational systems to the extent possible. Artificially softened particles were used in the simulation to reduce the computational time to a manageable level. Sensitivity study on the particle stiffness ensured such artificial modification was acceptable. In the experiment, a range of normal stress was applied to a given amount of particles sheared in an annular trough with a range of controlled shear speed. Two types of particles, glass and Delrin, were used in the experiment. Qualitatively, the required torque to shear the materials under different rotational speed compared well with those in the physical experiments for both the glass and the Delrin particles. However, the quantitative discrepancies between the measured and simulated shear stresses were nearly a factor of two. Boundary conditions, particle size distribution, particle damping and friction, including a sliding and rolling, contact force model, were examined to determine their effects on the computational results. It was found that of the above, the rolling friction between particles had the most significant effect on the macro stress level. This study shows that discrete element simulation is a viable method for engineering design for granular material systems. Particle level information is needed to properly conduct these simulations. However, not all particle level information is equally important in the study regime. Rolling friction, which is not commonly considered in many discrete element models, appears to play an important role. ?? 2009 Elsevier Ltd.

A Model for Generation of Martian Surface Dust, Soil and Rock Coatings: Physical vs. Chemical Interactions, and Palagonitic Plus Hydrothermal Alteration

NASA Technical Reports Server (NTRS)

Bishop, J. L.; Murchie, S.; Pieters, C.; Zent, A.

1999-01-01

This model is one of many possible scenarios to explain the generation of the current surface material on Mars using chemical, magnetic and spectroscopic data from Mars and geologic analogs from terrestrial sites. One basic premise is that there are physical and chemical interactions of the atmospheric dust particles and that these two processes create distinctly different results. Physical processes distribute dust particles on rocks, forming physical rock coatings, and on the surface between rocks forming soil units; these are reversible processes. Chemical reactions of the dust/soil particles create alteration rinds on rock surfaces or duricrust surface units, both of which are relatively permanent materials. According to this model the mineral components of the dust/soil particles are derived from a combination of "typical" palagonitic weathering of volcanic ash and hydrothermally altered components, primarily from steam vents or fumeroles. Both of these altered materials are composed of tiny particles, about 1 micron or smaller, that are aggregates of silicates and iron oxide/oxyhydroxide/sulfate phases. Additional information is contained in the original extended abstract.

Spatial entanglement patterns and Einstein-Podolsky-Rosen steering in Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Fadel, Matteo; Zibold, Tilman; Décamps, Boris; Treutlein, Philipp

2018-04-01

Many-particle entanglement is a fundamental concept of quantum physics that still presents conceptual challenges. Although nonclassical states of atomic ensembles were used to enhance measurement precision in quantum metrology, the notion of entanglement in these systems was debated because the correlations among the indistinguishable atoms were witnessed by collective measurements only. Here, we use high-resolution imaging to directly measure the spin correlations between spatially separated parts of a spin-squeezed Bose-Einstein condensate. We observe entanglement that is strong enough for Einstein-Podolsky-Rosen steering: We can predict measurement outcomes for noncommuting observables in one spatial region on the basis of corresponding measurements in another region with an inferred uncertainty product below the Heisenberg uncertainty bound. This method could be exploited for entanglement-enhanced imaging of electromagnetic field distributions and quantum information tasks.

Fast Particle Methods for Multiscale Phenomena Simulations

NASA Technical Reports Server (NTRS)

Koumoutsakos, P.; Wray, A.; Shariff, K.; Pohorille, Andrew

2000-01-01

We are developing particle methods oriented at improving computational modeling capabilities of multiscale physical phenomena in : (i) high Reynolds number unsteady vortical flows, (ii) particle laden and interfacial flows, (iii)molecular dynamics studies of nanoscale droplets and studies of the structure, functions, and evolution of the earliest living cell. The unifying computational approach involves particle methods implemented in parallel computer architectures. The inherent adaptivity, robustness and efficiency of particle methods makes them a multidisciplinary computational tool capable of bridging the gap of micro-scale and continuum flow simulations. Using efficient tree data structures, multipole expansion algorithms, and improved particle-grid interpolation, particle methods allow for simulations using millions of computational elements, making possible the resolution of a wide range of length and time scales of these important physical phenomena.The current challenges in these simulations are in : [i] the proper formulation of particle methods in the molecular and continuous level for the discretization of the governing equations [ii] the resolution of the wide range of time and length scales governing the phenomena under investigation. [iii] the minimization of numerical artifacts that may interfere with the physics of the systems under consideration. [iv] the parallelization of processes such as tree traversal and grid-particle interpolations We are conducting simulations using vortex methods, molecular dynamics and smooth particle hydrodynamics, exploiting their unifying concepts such as : the solution of the N-body problem in parallel computers, highly accurate particle-particle and grid-particle interpolations, parallel FFT's and the formulation of processes such as diffusion in the context of particle methods. This approach enables us to transcend among seemingly unrelated areas of research.

Basics of particle therapy I: physics

PubMed Central

Park, Seo Hyun

2011-01-01

With the advance of modern radiation therapy technique, radiation dose conformation and dose distribution have improved dramatically. However, the progress does not completely fulfill the goal of cancer treatment such as improved local control or survival. The discordances with the clinical results are from the biophysical nature of photon, which is the main source of radiation therapy in current field, with the lower linear energy transfer to the target. As part of a natural progression, there recently has been a resurgence of interest in particle therapy, specifically using heavy charged particles, because these kinds of radiations serve theoretical advantages in both biological and physical aspects. The Korean government is to set up a heavy charged particle facility in Korea Institute of Radiological & Medical Sciences. This review introduces some of the elementary physics of the various particles for the sake of Korean radiation oncologists' interest. PMID:22984664

Predicting physiological capacity of human load carriage - a review.

PubMed

Drain, Jace; Billing, Daniel; Neesham-Smith, Daniel; Aisbett, Brad

2016-01-01

This review article aims to evaluate a proposed maximum acceptable work duration model for load carriage tasks. It is contended that this concept has particular relevance to physically demanding occupations such as military and firefighting. Personnel in these occupations are often required to perform very physically demanding tasks, over varying time periods, often involving load carriage. Previous research has investigated concepts related to physiological workload limits in occupational settings (e.g. industrial). Evidence suggests however, that existing (unloaded) workload guidelines are not appropriate for load carriage tasks. The utility of this model warrants further work to enable prediction of load carriage durations across a range of functional workloads for physically demanding occupations. If the maximum duration for which personnel can physiologically sustain a load carriage task could be accurately predicted, commanders and supervisors could better plan for and manage tasks to ensure operational imperatives were met whilst minimising health risks for their workers. Copyright © 2015 Elsevier Ltd and The Ergonomics Society. All rights reserved.

Physically active academic lessons and time on task: the moderating effect of body mass index.

PubMed

Grieco, Lauren A; Jowers, Esbelle M; Bartholomew, John B

2009-10-01

Physically active classroom lessons have been found to increase on-task behavior in children. Given that physical activity has been associated with an increased time on task (TOT) and that overweight children take fewer steps than normal weight children do, it was expected that benefits of the physical activity would differentially impact those children of higher weight status. To examine the effects of a physically active classroom lesson and body mass index (BMI) category on TOT in a sample of elementary-aged children (N = 97). Behavior was assessed through direct observations before and after a physically active classroom lesson and before and after a traditional inactive classroom lesson. TOT was calculated through momentary time sampling for each student by dividing the number of on-task observations by the total number of observations per student (interrater reliability = 94%). TOT decreased significantly from before to after the lesson for all BMI categories in the inactive control condition, with no change for the active condition. Post hoc analyses found a significant linear effect for the reduction in TOT with each level of BMI in the inactive condition, with the greatest magnitude of effect for the overweight group. Physically active classroom lessons provide a buffer to prevent the steep reduction in TOT experienced after a period of inactivity in all children, especially those who are overweight.

The Effects of Mental Fatigue on Physical Performance: A Systematic Review.

PubMed

Van Cutsem, Jeroen; Marcora, Samuele; De Pauw, Kevin; Bailey, Stephen; Meeusen, Romain; Roelands, Bart

2017-08-01

Mental fatigue is a psychobiological state caused by prolonged periods of demanding cognitive activity. It has recently been suggested that mental fatigue can affect physical performance. Our objective was to evaluate the literature on impairment of physical performance due to mental fatigue and to create an overview of the potential factors underlying this effect. Two electronic databases, PubMed and Web of Science (until 28 April 2016), were searched for studies designed to test whether mental fatigue influenced performance of a physical task or influenced physiological and/or perceptual responses during the physical task. Studies using short (<30 min) self-regulatory depletion tasks were excluded from the review. A total of 11 articles were included, of which six were of strong and five of moderate quality. The general finding was a decline in endurance performance (decreased time to exhaustion and self-selected power output/velocity or increased completion time) associated with a higher than normal perceived exertion. Physiological variables traditionally associated with endurance performance (heart rate, blood lactate, oxygen uptake, cardiac output, maximal aerobic capacity) were unaffected by mental fatigue. Maximal strength, power, and anaerobic work were not affected by mental fatigue. The duration and intensity of the physical task appear to be important factors in the decrease in physical performance due to mental fatigue. The most important factor responsible for the negative impact of mental fatigue on endurance performance is a higher perceived exertion.

Intraindividual variability in physical and emotional functioning: comparison of adults with traumatic brain injuries and healthy adults.

PubMed

Burton, Catherine L; Hultsch, David F; Strauss, Esther; Hunter, Michael A

2002-08-01

Recent research has shown that individuals with certain neurological conditions demonstrate greater intraindividual variability on cognitive tasks compared to healthy controls. The present study investigated intraindividual variability in the domains of physical functioning and affect/stress in three groups: adults with mild head injuries, adults with moderate/severe head injuries, and healthy adults. Participants were assessed on 10 occasions and results indicated that (a) individuals with head injuries demonstrated greater variability in dominant finger dexterity and right grip strength than the healthy controls; (b) increased variability tended to be associated with poorer performance/report both within and across tasks; and (c) increased variability on one task was associated with increased variability on other tasks. The findings suggest that increased variability in physical function, as well as cognitive function, represents an indicator of neurological compromise.

Risk assessments using the Strain Index and the TLV for HAL, Part II: Multi-task jobs and prevalence of CTS.

PubMed

Kapellusch, Jay M; Silverstein, Barbara A; Bao, Stephen S; Thiese, Mathew S; Merryweather, Andrew S; Hegmann, Kurt T; Garg, Arun

2018-02-01

The Strain Index (SI) and the American Conference of Governmental Industrial Hygienists (ACGIH) threshold limit value for hand activity level (TLV for HAL) have been shown to be associated with prevalence of distal upper-limb musculoskeletal disorders such as carpal tunnel syndrome (CTS). The SI and TLV for HAL disagree on more than half of task exposure classifications. Similarly, time-weighted average (TWA), peak, and typical exposure techniques used to quantity physical exposure from multi-task jobs have shown between-technique agreement ranging from 61% to 93%, depending upon whether the SI or TLV for HAL model was used. This study compared exposure-response relationships between each model-technique combination and prevalence of CTS. Physical exposure data from 1,834 workers (710 with multi-task jobs) were analyzed using the SI and TLV for HAL and the TWA, typical, and peak multi-task job exposure techniques. Additionally, exposure classifications from the SI and TLV for HAL were combined into a single measure and evaluated. Prevalent CTS cases were identified using symptoms and nerve-conduction studies. Mixed effects logistic regression was used to quantify exposure-response relationships between categorized (i.e., low, medium, and high) physical exposure and CTS prevalence for all model-technique combinations, and for multi-task workers, mono-task workers, and all workers combined. Except for TWA TLV for HAL, all model-technique combinations showed monotonic increases in risk of CTS with increased physical exposure. The combined-models approach showed stronger association than the SI or TLV for HAL for multi-task workers. Despite differences in exposure classifications, nearly all model-technique combinations showed exposure-response relationships with prevalence of CTS for the combined sample of mono-task and multi-task workers. Both the TLV for HAL and the SI, with the TWA or typical techniques, appear useful for epidemiological studies and surveillance. However, the utility of TWA, typical, and peak techniques for job design and intervention is dubious.

Protocol for Direct Counterfactual Quantum Communication

NASA Astrophysics Data System (ADS)

Salih, Hatim; Li, Zheng-Hong; Al-Amri, M.; Zubairy, M. Suhail

2013-04-01

It has long been assumed in physics that for information to travel between two parties in empty space, “Alice” and “Bob,” physical particles have to travel between them. Here, using the “chained” quantum Zeno effect, we show how, in the ideal asymptotic limit, information can be transferred between Alice and Bob without any physical particles traveling between them.

Particle-fluid interactions for flow measurements

NASA Technical Reports Server (NTRS)

Berman, N. S.

1973-01-01

Study has been made of the motion of single particle and of group of particles, emphasizing solid particles in gaseous fluid. Velocities of fluid and particle are compared for several conditions of physical interest. Mean velocity and velocity fluctuations are calculated for single particle, and some consideration is given to multiparticle systems.

Matter and Interactions: A Particle Physics Perspective

ERIC Educational Resources Information Center

Organtini, Giovanni

2011-01-01

In classical mechanics, matter and fields are completely separated; matter interacts with fields. For particle physicists this is not the case; both matter and fields are represented by particles. Fundamental interactions are mediated by particles exchanged between matter particles. In this article we explain why particle physicists believe in…

Long Pulse Operation on Tore-Supra: Towards Steady State

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moreau, P.; Bucalossi, J.; Brosset, C.

The experimental programme of Tore Supra is devoted to the study of technology and physics issues associated to long-duration high performance discharges. This new domain of operation requires simultaneously and in steady state: heat removal capability, particle exhaust, fully non-inductive current drive, advanced technology integration and real time plasma control. The long discharge allows for addressing new time scale physic such as the wall particle retention and erosion. Moreover, the physics of fully non-inductive discharges is full of novelty, namely: the MHD stability, the slow spontaneous oscillation of the central electron temperature or the outstanding inward particle pinch.

Exploring the SCOAP3 Research Contributions of the United States

NASA Astrophysics Data System (ADS)

Marsteller, Matthew

2016-03-01

The Sponsoring Consortium for Open Access Publishing in Particle Physics (SCOAP3) is a successful global partnership of libraries, funding agencies and research centers. This presentation will inform the audience about SCOAP3 and also delve into descriptive statistics of the United States' intellectual contribution to particle physics via these open access journals. Exploration of the SCOAP3 particle physics literature using a variety of metrics tools such as Web of Science™, InCites™, Scopus® and SciVal will be shared. ORA or Sci2 will be used to visualize author collaboration networks.

AF-GEOSpace Version 2.1 Release

NASA Astrophysics Data System (ADS)

Hilmer, R. V.; Ginet, G. P.; Hall, T.; Holeman, E.; Madden, D.; Perry, K. L.; Tautz, M.; Roth, C.

2006-05-01

AF-GEOSpace Version 2.1 is a graphics-intensive software program with space environment models and applications developed recently by the Space Weather Center of Excellence at AFRL. A review of new and planned AF-GEOSpace capabilities will be given. The software addresses a wide range of physical domains and addresses such topics as solar disturbance propagation, geomagnetic field and radiation belt configurations, auroral particle precipitation, and ionospheric scintillation. Building on the success of previous releases, AF-GEOSpace has become a platform for the rapid prototyping of automated operational and simulation space weather visualization products and helps with a variety of tasks, including: orbit specification for radiation hazard avoidance; satellite design assessment and post-event anomaly analysis; solar disturbance effects forecasting; determination of link outage regions for active ionospheric conditions; satellite magnetic conjugate studies, scientific model validation and comparison, physics research, and education. Previously, Version 2.0 provided a simplified graphical user interface, improved science and application modules, significantly enhanced graphical performance, common input data archive sets, and 1-D, 2-D, and 3- D visualization tools for all models. Dynamic capabilities permit multiple environments to be generated at user- specified time intervals while animation tools enable the display of satellite orbits and environment data together as a function of time. Building on the Version 2.0 software architecture, AF-GEOSpace Version 2.1 includes a host of new modules providing, for example, plasma sheet charged particle fluxes, neutral atmosphere densities, 3-D cosmic ray cutoff maps, low-altitude trapped proton belt flux specification, DMSP particle data displays, satellite magnetic field footprint mapping determination, and meteor sky maps and shower/storm fluxes with spacecraft impact probabilities. AF-GEOSpace Version 2.1 was developed for Windows XP and Linux systems. To receive a copy of the AF-GEOSpace 2.1 software, please submit requests via e-mail to the first author.

Particle Identification on an FPGA Accelerated Compute Platform for the LHCb Upgrade

NASA Astrophysics Data System (ADS)

Fäerber, Christian; Schwemmer, Rainer; Machen, Jonathan; Neufeld, Niko

2017-07-01

The current LHCb readout system will be upgraded in 2018 to a “triggerless” readout of the entire detector at the Large Hadron Collider collision rate of 40 MHz. The corresponding bandwidth from the detector down to the foreseen dedicated computing farm (event filter farm), which acts as the trigger, has to be increased by a factor of almost 100 from currently 500 Gb/s up to 40 Tb/s. The event filter farm will preanalyze the data and will select the events on an event by event basis. This will reduce the bandwidth down to a manageable size to write the interesting physics data to tape. The design of such a system is a challenging task, and the reason why different new technologies are considered and have to be investigated for the different parts of the system. For the usage in the event building farm or in the event filter farm (trigger), an experimental field programmable gate array (FPGA) accelerated computing platform is considered and, therefore, tested. FPGA compute accelerators are used more and more in standard servers such as for Microsoft Bing search or Baidu search. The platform we use hosts a general Intel CPU and a high-performance FPGA linked via the high-speed Intel QuickPath Interconnect. An accelerator is implemented on the FPGA. It is very likely that these platforms, which are built, in general, for high-performance computing, are also very interesting for the high-energy physics community. First, the performance results of smaller test cases performed at the beginning are presented. Afterward, a part of the existing LHCb RICH particle identification is tested and is ported to the experimental FPGA accelerated platform. We have compared the performance of the LHCb RICH particle identification running on a normal CPU with the performance of the same algorithm, which is running on the Xeon-FPGA compute accelerator platform.

Risk assessments using the Strain Index and the TLV for HAL, Part I: Task and multi-task job exposure classifications.

PubMed

Kapellusch, Jay M; Bao, Stephen S; Silverstein, Barbara A; Merryweather, Andrew S; Thiese, Mathew S; Hegmann, Kurt T; Garg, Arun

2017-12-01

The Strain Index (SI) and the American Conference of Governmental Industrial Hygienists (ACGIH) Threshold Limit Value for Hand Activity Level (TLV for HAL) use different constituent variables to quantify task physical exposures. Similarly, time-weighted-average (TWA), Peak, and Typical exposure techniques to quantify physical exposure from multi-task jobs make different assumptions about each task's contribution to the whole job exposure. Thus, task and job physical exposure classifications differ depending upon which model and technique are used for quantification. This study examines exposure classification agreement, disagreement, correlation, and magnitude of classification differences between these models and techniques. Data from 710 multi-task job workers performing 3,647 tasks were analyzed using the SI and TLV for HAL models, as well as with the TWA, Typical and Peak job exposure techniques. Physical exposures were classified as low, medium, and high using each model's recommended, or a priori limits. Exposure classification agreement and disagreement between models (SI, TLV for HAL) and between job exposure techniques (TWA, Typical, Peak) were described and analyzed. Regardless of technique, the SI classified more tasks as high exposure than the TLV for HAL, and the TLV for HAL classified more tasks as low exposure. The models agreed on 48.5% of task classifications (kappa = 0.28) with 15.5% of disagreement between low and high exposure categories. Between-technique (i.e., TWA, Typical, Peak) agreement ranged from 61-93% (kappa: 0.16-0.92) depending on whether the SI or TLV for HAL was used. There was disagreement between the SI and TLV for HAL and between the TWA, Typical and Peak techniques. Disagreement creates uncertainty for job design, job analysis, risk assessments, and developing interventions. Task exposure classifications from the SI and TLV for HAL might complement each other. However, TWA, Typical, and Peak job exposure techniques all have limitations. Part II of this article examines whether the observed differences between these models and techniques produce different exposure-response relationships for predicting prevalence of carpal tunnel syndrome.

Task-based exposure assessment of nanoparticles in the workplace

NASA Astrophysics Data System (ADS)

Ham, Seunghon; Yoon, Chungsik; Lee, Euiseung; Lee, Kiyoung; Park, Donguk; Chung, Eunkyo; Kim, Pilje; Lee, Byoungcheun

2012-09-01

Although task-based sampling is, theoretically, a plausible approach to the assessment of nanoparticle exposure, few studies using this type of sampling have been published. This study characterized and compared task-based nanoparticle exposure profiles for engineered nanoparticle manufacturing workplaces (ENMW) and workplaces that generated welding fumes containing incidental nanoparticles. Two ENMW and two welding workplaces were selected for exposure assessments. Real-time devices were utilized to characterize the concentration profiles and size distributions of airborne nanoparticles. Filter-based sampling was performed to measure time-weighted average (TWA) concentrations, and off-line analysis was performed using an electron microscope. Workplace tasks were recorded by researchers to determine the concentration profiles associated with particular tasks/events. This study demonstrated that exposure profiles differ greatly in terms of concentrations and size distributions according to the task performed. The size distributions recorded during tasks were different from both those recorded during periods with no activity and from the background. The airborne concentration profiles of the nanoparticles varied according to not only the type of workplace but also the concentration metrics. The concentrations measured by surface area and the number concentrations measured by condensation particle counter, particulate matter 1.0, and TWA mass concentrations all showed a similar pattern, whereas the number concentrations measured by scanning mobility particle sizer indicated that the welding fume concentrations at one of the welding workplaces were unexpectedly higher than were those at workplaces that were engineering nanoparticles. This study suggests that a task-based exposure assessment can provide useful information regarding the exposure profiles of nanoparticles and can therefore be used as an exposure assessment tool.

A Toolkit to Study Sensitivity of the Geant4 Predictions to the Variations of the Physics Model Parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fields, Laura; Genser, Krzysztof; Hatcher, Robert

Geant4 is the leading detector simulation toolkit used in high energy physics to design detectors and to optimize calibration and reconstruction software. It employs a set of carefully validated physics models to simulate interactions of particles with matter across a wide range of interaction energies. These models, especially the hadronic ones, rely largely on directly measured cross-sections and phenomenological predictions with physically motivated parameters estimated by theoretical calculation or measurement. Because these models are tuned to cover a very wide range of possible simulation tasks, they may not always be optimized for a given process or a given material. Thismore » raises several critical questions, e.g. how sensitive Geant4 predictions are to the variations of the model parameters, or what uncertainties are associated with a particular tune of a Geant4 physics model, or a group of models, or how to consistently derive guidance for Geant4 model development and improvement from a wide range of available experimental data. We have designed and implemented a comprehensive, modular, user-friendly software toolkit to study and address such questions. It allows one to easily modify parameters of one or several Geant4 physics models involved in the simulation, and to perform collective analysis of multiple variants of the resulting physics observables of interest and comparison against a variety of corresponding experimental data. Based on modern event-processing infrastructure software, the toolkit offers a variety of attractive features, e.g. flexible run-time configurable workflow, comprehensive bookkeeping, easy to expand collection of analytical components. Design, implementation technology, and key functionalities of the toolkit are presented and illustrated with results obtained with Geant4 key hadronic models.« less

Children's Concepts of How People Get Babies

ERIC Educational Resources Information Center

Bernstein, Anne C.; Cowan, Philip A.

1975-01-01

Twenty children, 3-12 years old, were given a newly constructed interview on their concepts of human reproduction (social causality), in conjunction with Piaget-type tasks assessing physical conservation-identity, physical causality, and a new social identity task. The children's concepts of human reproduction appeared to proceed through a…

Children's Incidental Memory for Pictures: Item Processing Versus List Organizations.

ERIC Educational Resources Information Center

Ghatala, Elizabeth S.; Levin, Joel R.

1981-01-01

Two experiments which tested recall differences among young children indicated: (1) organizational factors, not item processing per se, influenced previously found differences in children's recall of pictures following semantic and physical orienting tasks; and (2) physical orienting tasks may effectively inhibit subjects' processing of words, but…

Teaching for Skill Mastery

ERIC Educational Resources Information Center

Chepko, Stevie; Doan, Robert

2015-01-01

This article focuses on establishing a mastery climate where all students find success and start on the road to physical literacy. Using a five-step approach, physical educators will be offered guidance for developing practice tasks that lead to skill mastery. These steps include creating a mastery environment, designing deliberate practice tasks,…

Attention and Encoding in Physics Learning and Problem Solving

ERIC Educational Resources Information Center

Feil, Adam John

2009-01-01

This dissertation presents several studies designed to probe the mental representations that physics experts and novices form when interacting with typical instructional materials, such as diagrams and problem statements. By using recognition tasks and a change detection task, the mental representations of experts and novices are studied in a more…

Content Specificity of Expectancy Beliefs and Task Values in Elementary Physical Education

ERIC Educational Resources Information Center

Chen, Ang; Martin, Robert; Ennis, Catherine D.; Sun, Haichun

2008-01-01

The curriculum may superimpose a content-specific context that mediates motivation (Bong, 2001). This study examined content specificity of the expectancy-value motivation in elementary school physical education. Students' expectancy beliefs and perceived task values from a cardiorespiratory fitness unit, a muscular fitness unit, and a traditional…

Space physics educational outreach

NASA Technical Reports Server (NTRS)

Copeland, Richard A.

1995-01-01

The goal of this Space Physics Educational Outreach project was to develop a laboratory experiment and classroom lecture on Earth's aurora for use in lower division college physics courses, with the particular aim of implementing the experiment and lecture at Saint Mary's College of California. The strategy is to teach physics in the context of an interesting natural phenomenon by investigating the physical principles that are important in Earth's aurora, including motion of charged particles in electric and magnetic fields, particle collisions and chemical reactions, and atomic and molecular spectroscopy. As a by-product, the undergraduate students would develop an appreciation for naturally occurring space physics phenomena.

The Entrance test of physics and Workbook in teaching of physics at secondary vocational school within long-term pedagogical research

NASA Astrophysics Data System (ADS)

Kerlínová, Věra

2017-01-01

Within the long-term pedagogical research ongoing since the school year 2008/2009 to 2015/2016 at the secondary vocational school in Bohumín was through of Entrance test of physics, which included curriculum of the sixth to ninth year of elementary school, regularly finding out, in which parts of Entrance test - Unit conversions, International System of Units, Properties of matter, Mechanics, Thermodynamics, Electricity and Magnetism, Optics, Atoms and Universe - pupils of the 1st years of secondary vocational school, technical and non-technical, reach a higher number of correct answers, in which dominates the wrong answers and which parts of the test pupils are better left out completely. It turned out that the results of these tests are very informative not only for theoretical and practical teaching, but also technical and other science subjects. The results of the Entrance tests are also a valuable source of information for continuous innovation Workbook of Physics - Mechanics for the 1st year of secondary vocational schools [1] - whose the first version began during the school year 2007/2008 and which was tested within pre-research in school years 2008/2009, 2009/2010 and within research in school year 2010/2011. On the basis of feedbacks getting from research the Workbook is regularly expanded, innovated and updated. The Workbook consists of parts dedicated to physical concepts, physical tasks, proposals to physical experiments, pupils comments from viewed video projection and documentary films, examples from the world of science and technology, examples from practice and real life, physical terminology in English, quizzes, competitions, interesting things and links related to discussed curriculum. The Workbook is divided into thematic sections, chapters and subchapters similar as physics textbooks for pupils of the 1st years of Secondary Schools in the Czech Republic. In the Workbook there are included tasks on fill in the words, polynomial tasks with choice answer "one right answer", tasks assignment, tasks to sketching to the pictures and physical tasks including graphic sketches. Long-term research through the Entrance test of physics and the use of the Workbook in physics teaching will continue in the school year 2016/2017 and not just among pupils of the 1st years of secondary vocational school, but also pupils at grammar school, where the research was conducted in the school year 2010/2011 and 2014/2015.

Neurophysiological correlates of visuo-motor learning through mental and physical practice.

PubMed

Allami, Nadia; Brovelli, Andrea; Hamzaoui, El Mehdi; Regragui, Fakhita; Paulignan, Yves; Boussaoud, Driss

2014-03-01

We have previously shown that mental rehearsal can replace up to 75% of physical practice for learning a visuomotor task (Allami, Paulignan, Brovelli, & Boussaoud, (2008). Experimental Brain Research, 184, 105-113). Presumably, mental rehearsal must induce brain changes that facilitate motor learning. We tested this hypothesis by recording scalp electroencephalographic activity (EEG) in two groups of subjects. In one group, subjects executed a reach to grasp task for 240 trials. In the second group, subjects learned the task through a combination of mental rehearsal for the initial 180 trials followed by the execution of 60 trials. Thus, one group physically executed the task for 240 trials, the other only for 60 trials. Amplitudes and latencies of event-related potentials (ERPs) were compared across groups at different stages during learning. We found that ERP activity increases dramatically with training and reaches the same amplitude over the premotor regions in the two groups, despite large differences in physically executed trials. These findings suggest that during mental rehearsal, neuronal changes occur in the motor networks that make physical practice after mental rehearsal more effective in configuring functional networks for skilful behaviour. Copyright © 2013 Elsevier Ltd. All rights reserved.

Cosmology of Universe Particles and Beyond

NASA Astrophysics Data System (ADS)

Xu, Wei

2016-06-01

For the first time in history, all properties of cosmology particles are uncovered and described concisely and systematically, known as the elementary particles in contemporary physics.Aligning with the synthesis of the virtual and physical worlds in a hierarchical taxonomy of the universe, this theory refines the topology framework of cosmology, and presents a new perspective of the Yin Yang natural laws that, through the processes of creation and reproduction, the fundamental elements generate an infinite series of circular objects and a Yin Yang duality of dynamic fields that are sequenced and transformed states of matter between the virtual and physical worlds.Once virtual objects are transformed, they embody various enclaves of energy states, known as dark energy, quarks, leptons, bosons, protons, and neutrons, characterized by their incentive oscillations of timestate variables in a duality of virtual realities: energy and time, spin and charge, mass and space, symmetry and antisymmetry.As a consequence, it derives the fully-scaled quantum properties of physical particles in accordance with numerous historical experiments, and has overcome the limitations of uncertainty principle and the Standard Model, towards concisely exploring physical nature and beyond...

Precision Crystal Calorimeters in High Energy Physics

ScienceCinema

Ren-Yuan Zhu

2017-12-09

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal’s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

2017 Topical Workshop on Electronics for Particle Physics

NASA Astrophysics Data System (ADS)

2017-09-01

The workshop will cover all aspects of electronics for particle physics experiments, and accelerator instrumentation of general interest to users. LHC experiments (and their operational experience) will remain a focus of the meeting but a strong emphasis on R&D for future experimentation will be maintained, such as SLHC, CLIC, ILC, neutrino facilities as well as other particle and astroparticle physics experiments. The purpose of the workshop is: To present results and original concepts for electronic research and development relevant to experiments as well as accelerator and beam instrumentation at future facilities; To review the status of electronics for the LHC experiments; To identify and encourage common efforts for the development of electronics; To promote information exchange and collaboration in the relevant engineering and physics communities.

Moderate-to-vigorous physically active academic lessons and academic engagement in children with and without a social disadvantage: a within subject experimental design.

PubMed

Mullender-Wijnsma, Marijke J; Hartman, Esther; de Greeff, Johannes W; Bosker, Roel J; Doolaard, Simone; Visscher, Chris

2015-04-19

Integration of physical active academic lessons in the school curriculum may be an innovative way to improve academic outcomes. This study examined the effect of physically active academic lessons (Fit en Vaardig op school) on academic engagement of socially disadvantaged children and children without this disadvantage. In addition, the relationship between lesson time spent in moderate to vigorous physical activity and academic engagement was examined. From four elementary schools, 86 children who participated in the 22-weeks intervention were recruited (23 socially disadvantaged children). Academic engagement was determined by observing time-on-task during three classroom observation moments (start, midway and end observation). Every moment consisted of lesson observations after intervention lessons (post-intervention) and after regular classroom lessons (post-control). Differences in time-on-task between socially disadvantaged children and children without this disadvantage were analyzed using independent samples t-test. Differences between post-intervention and post-control observations were analyzed using multilevel analysis. Heart rate monitors measured the lesson time spent in moderate to vigorous physical activity. The relationship between percentage of moderate to vigorous physical activity during the intervention lessons and time-on-task was analyzed by calculation of partial correlations. Time-on-task of socially disadvantaged children was lower than that of children without this disadvantage, differences were significant at the start post-control (t(65) = 2.39, p < 0.05) and post-intervention (t(71) = 2.75, p < 0.05) observation and at the midway post-control (t(68) = 2.45, p < 0.05) observation. Multilevel analysis showed that the time-on-task of all children was significantly higher during post-intervention in comparison with post-control lessons (ES = 0.41). No significant difference was found at the start observation, but there were significant differences at the midway (ES = 0.60) and end (ES = 0.59) observation. On average, the children were exercising in moderate to vigorous physical activity during 60% of de lesson time (14 minutes of an average lesson of 23 minutes). No significant relationships were found between percentage of moderate to vigorous physical activity during the intervention and time-on-task in the post-intervention lessons. Physically active academic lessons may positively influence time-on-task in children, which can contribute to academic success in the long term.

The pLISA project in ASTERICS

NASA Astrophysics Data System (ADS)

De Bonis, Giulia; Bozza, Cristiano

2017-03-01

In the framework of Horizon 2020, the European Commission approved the ASTERICS initiative (ASTronomy ESFRI and Research Infrastructure CluSter) to collect knowledge and experiences from astronomy, astrophysics and particle physics and foster synergies among existing research infrastructures and scientific communities, hence paving the way for future ones. ASTERICS aims at producing a common set of tools and strategies to be applied in Astronomy ESFRI facilities. In particular, it will target the so-called multi-messenger approach to combine information from optical and radio telescopes, photon counters and neutrino telescopes. pLISA is a software tool under development in ASTERICS to help and promote machine learning as a unified approach to multivariate analysis of astrophysical data and signals. The library will offer a collection of classification parameters, estimators, classes and methods to be linked and used in reconstruction programs (and possibly also extended), to characterize events in terms of particle identification and energy. The pLISA library aims at offering the software infras tructure for applications developed inside different experiments and has been designed with an effort to extrapolate general, physics-related estimators from the specific features of the data model related to each particular experiment. pLISA is oriented towards parallel computing architectures, with awareness of the opportunity of using GPUs as accelerators demanding specifically optimized algorithms and to reduce the costs of pro cessing hardware requested for the reconstruction tasks. Indeed, a fast (ideally, real-time) reconstruction can open the way for the development or improvement of alert systems, typically required by multi-messenger search programmes among the different experi mental facilities involved in ASTERICS.

Unraveling the Mysteries of the Atom.

ERIC Educational Resources Information Center

Lederman, Leon

1982-01-01

The development, role, and current research in particle physics at the Fermi National Accelerator Laboratory are reviewed, including discussions of its mission to understand the structure of matter, a brief history of particle physics, and the nature and applications of superconductivity, among other topics. (JN)

Quantum Tasks with Non-maximally Quantum Channels via Positive Operator-Valued Measurement

NASA Astrophysics Data System (ADS)

Peng, Jia-Yin; Luo, Ming-Xing; Mo, Zhi-Wen

2013-01-01

By using a proper positive operator-valued measure (POVM), we present two new schemes for probabilistic transmission with non-maximally four-particle cluster states. In the first scheme, we demonstrate that two non-maximally four-particle cluster states can be used to realize probabilistically sharing an unknown three-particle GHZ-type state within either distant agent's place. In the second protocol, we demonstrate that a non-maximally four-particle cluster state can be used to teleport an arbitrary unknown multi-particle state in a probabilistic manner with appropriate unitary operations and POVM. Moreover the total success probability of these two schemes are also worked out.

Method and apparatus for separating material

DOEpatents

Oder, Robin R.; Jamison, Russell E.

2006-10-24

An apparatus for sorting particles composed of a mixture of particles with differing physical and chemical characteristics. The apparatus includes a comminutor, a mechanism for removing particles from the inside of the comminutor which are intermediate in size between the feed to the comminutor and the product of comminution, a mechanism for either discharging particles taken from the comminutor to a reject stream or providing them to a size classification apparatus such as screening, a mechanism for returning the oversize particles to the comminutor or for discharging them to the reject stream, an electric mechanism for separating particles with an electrical force disposed adjacent to a magnet mechanism, a mechanism for providing the particles to the magnet mechanism and the electric mechanism and for providing triboelectric and capacitive charges to the particles, and a mechanism for returning one of the products of electric and magnetic separation to the comminutor while discharging the other to the reject stream. A method for sorting particles composed of a mixture of particles with differing physical and chemical characteristics.

The role of physical content in piagetian spatial tasks: Sex differences in spatial knowledge?

NASA Astrophysics Data System (ADS)

Golbeck, Susan L.

Sex-related differences on Piagetian horizontality (water level) and verticality (plumb line) tasks were examined in 64 college students. It was hypothesized that females' difficulties on these Euclidean spatial problems are due not to differences in underlying spatial competence, but rather to differences in knowledge of task specific information about the physical properties of water levels and plumb lines. This was tested by presenting subjects with the standard water level and plumb line problems and also modified problems not requiring knowledge of physical principles (i.e., drawing straight up and down or straight across lines inside tipped rectangles). While males were expected to outperform females on the standard tasks, no sex differences were expected on the modified tasks. Results of an ANOVA on scores for horizontality and verticality each showed main effects for sex and task version but failed to reveal the hypothesized interaction. However, performance on the Euclidean spatial tasks was also considered in terms of overall success versus failure. While males were more successful than females in the standard format, males and females were equally successful in the modified, nonphysical, format. Hence, college aged males and females generally do not differ in spatial competence although they may be differentially influenced by task content. Findings are discussed in terms of their implications for theory and practice. It is emphasized that science educators must be especially aware of such task influences for females so that performance deficits are not mistaken for competence deficits.

Infinite efficiency of the collisional Penrose process: Can a overspinning Kerr geometry be the source of ultrahigh-energy cosmic rays and neutrinos?

NASA Astrophysics Data System (ADS)

Patil, Mandar; Harada, Tomohiro; Nakao, Ken-ichi; Joshi, Pankaj S.; Kimura, Masashi

2016-05-01

The origin of the ultrahigh-energy particles we receive on Earth from outer space such as EeV cosmic rays and PeV neutrinos remains an enigma. All mechanisms known to us currently make use of electromagnetic interaction to accelerate charged particles. In this paper, we propose a mechanism exclusively based on gravity rather than electromagnetic interaction. We show that it is possible to generate ultrahigh-energy particles starting from particles with moderate energies using the collisional Penrose process in an overspinning Kerr spacetime transcending the Kerr bound only by an infinitesimal amount, i.e., with the Kerr parameter a =M (1 +ɛ ) , where we take the limit ɛ →0+. We consider two massive particles starting from rest at infinity that collide at r =M with divergent center-of-mass energy and produce two massless particles. We show that massless particles produced in the collision can escape to infinity with the ultrahigh energies exploiting the collisional Penrose process with the divergent efficiency η ˜1 /√{ɛ }→∞ . Assuming the isotropic emission of massless particles in the center-of-mass frame of the colliding particles, we show that half of the particles created in the collisions escape to infinity with the divergent energies, while the proportion of particles that reach infinity with finite energy is minuscule. To a distant observer, ultrahigh-energy particles appear to originate from a bright spot which is at the angular location ξ ˜2 M /robs with respect to the singularity on the side which is rotating toward the observer. We compute the spectrum of the high-energy massless particles and show that anisotropy in the emission in the center-of-mass frame leaves a distinct signature on its shape. Since the anisotropy is dictated by the differential cross section of the underlying particle physics process, the observation of the spectrum can constrain the particle physics model and serve as a unique probe into fundamental physics at ultrahigh energies at which particles collide. Thus, the existence of the near-extremal overspinning Kerr geometry in the Universe, either as a transient or permanent configuration, would have deep implications on astrophysics as well as fundamental particle physics.

Nanomaterial release characteristics in a single-walled carbon nanotube manufacturing workplace

NASA Astrophysics Data System (ADS)

Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Bae, Gwi-Nam

2015-02-01

As carbon nanotubes (CNTs) are widely used in various applications, exposure assessment also increases in importance with other various toxicity tests for CNTs. We conducted 24-h continuous nanoaerosol measurements to identify possible nanomaterial release in a single-walled carbon nanotube (SWCNT) manufacturing workplace. Four real-time aerosol instruments were used to determine the nanosized and microsized particle numbers, particle surface area, and carbonaceous species. Task-based exposure assessment was carried out for SWCNT synthesis using the arc plasma and thermal decomposition processes to remove amorphous carbon components as impurities. During the SWCNT synthesis, the black carbon (BC) concentration was 2-12 μg/m3. The maximum BC mass concentrations occurred when the synthesis chamber was opened for harvesting the SWCNTs. The number concentrations of particles with sizes 10-420 nm were 10,000-40,000 particles/cm3 during the tasks. The maximum number concentration existed when a vacuum pump was operated to remove exhaust air from the SWCNT synthesis chamber due to the penetration of highly concentrated oil mists through the window opened. We analyzed the particle mass size distribution and particle number size distribution for each peak episode. Using real-time aerosol detectors, we distinguished the SWCNT releases from background nanoaerosols such as oil mist and atmospheric photochemical smog particles. SWCNT aggregates with sizes of 1-10 μm were mainly released from the arc plasma synthesis. The harvesting process was the main release route of SWCNTs in the workplace.

Data base on physical observations of near-Earth asteroids and establishment of a network to coordinate observations of newly discovered near-Earth asteroids

NASA Technical Reports Server (NTRS)

Davis, D. R.; Chapman, C. R.; Campins, H.

1990-01-01

This program consists of two tasks: (1) development of a data base of physical observations of near-earth asteroids and establishment of a network to coordinate observations of newly discovered earth-approaching asteroids; and (2) a simulation of the surface of low-activity comets. Significant progress was made on task one and, and task two was completed during the period covered by this progress report.

Characterization of Tungsten Inert Gas (TIG) Welding Fume Generated by Apprentice Welders

PubMed Central

Graczyk, Halshka; Lewinski, Nastassja; Zhao, Jiayuan; Concha-Lozano, Nicolas; Riediker, Michael

2016-01-01

Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm−3, with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training. PMID:26464505

Space Particle Hazard Measurement and Modeling

DTIC Science & Technology

2016-09-01

understand the interactions of the physical processes driving, then specify and ultimately predict the state of the energetic particle populations...Hudson, and B. T. Kress (2013), Direct observation of the CRAND proton radiation belt source, J. Geophys. Res. Space Physics , 118, doi:10.1002...anticritical temperature for spacecraft charging, J. Geophys Res.: Space Physics , 113, 2156-2202, doi: 10.1029/2008JA013161 2010 – Tested basic

Hydrothermal Synthesis of Metal Oxide Nanoparticles in Supercritical Water

PubMed Central

Hayashi, Hiromichi; Hakuta, Yukiya

2010-01-01

This paper summarizes specific features of supercritical hydrothermal synthesis of metal oxide particles. Supercritical water allows control of the crystal phase, morphology, and particle size since the solvent's properties, such as density of water, can be varied with temperature and pressure, both of which can affect the supersaturation and nucleation. In this review, we describe the advantages of fine particle formation using supercritical water and describe which future tasks need to be solved. PMID:28883312

Self-Reported Physical Tasks and Exercise Training in Special Weapons and Tactics (SWAT) Teams.

PubMed

Davis, Matthew R; Easter, Richard L; Carlock, Jonathan M; Weiss, Lawrence W; Longo, Elizabeth A; Smith, Lisa M; Dawes, J Jay; Schilling, Brian K

2016-11-01

Davis, MR, Easter, RL, Carlock, JM, Weiss, LW, Longo, EA, Smith, LM, Dawes, JJ, and Schilling, BK. Self-reported physical tasks and exercise training in Special Weapons and Tactics (SWAT) teams. J Strength Cond Res 30(11): 3242-3248, 2016-Little research has been done examining the most physically demanding tasks a SWAT officer may perform in the line of duty. Our objective was to analyze the rankings of tasks by SWAT officers based on frequency, difficulty, and importance and assess if training is addressing traits needed for successful task completion. A survey was designed using Qualtrics (Qualtrics Labs Inc). The survey had a demographics section, performance section, and training section. Officers were contacted by phone or e-mail and asked about interest in participating. Officers who agreed were sent the survey. Our results found a strong correlation between frequency of task and importance (r = 0.69, p = 0.001), and a moderate correlation was found between task difficulty and importance (r = 0.37, p = 0.005). Task rankings were averaged across the 3 domains to assess "overall" importance, and the top 3 tasks were assessed for necessary traits for successful performance. Power and strength were determined to be the most important traits for successful performance. Officers ranked the top 2 focuses of their training program in the training section as stamina/muscular endurance and cardiovascular/respiratory endurance. Training programs for SWAT officers should be developed to improve performance of the tasks with the highest "overall" importance. Therefore, a training program should emphasize strength and power improvements while not neglecting other measures of fitness.

Inertial microfluidic physics.

PubMed

Amini, Hamed; Lee, Wonhee; Di Carlo, Dino

2014-08-07

Microfluidics has experienced massive growth in the past two decades, and especially with advances in rapid prototyping researchers have explored a multitude of channel structures, fluid and particle mixtures, and integration with electrical and optical systems towards solving problems in healthcare, biological and chemical analysis, materials synthesis, and other emerging areas that can benefit from the scale, automation, or the unique physics of these systems. Inertial microfluidics, which relies on the unconventional use of fluid inertia in microfluidic platforms, is one of the emerging fields that make use of unique physical phenomena that are accessible in microscale patterned channels. Channel shapes that focus, concentrate, order, separate, transfer, and mix particles and fluids have been demonstrated, however physical underpinnings guiding these channel designs have been limited and much of the development has been based on experimentally-derived intuition. Here we aim to provide a deeper understanding of mechanisms and underlying physics in these systems which can lead to more effective and reliable designs with less iteration. To place the inertial effects into context we also discuss related fluid-induced forces present in particulate flows including forces due to non-Newtonian fluids, particle asymmetry, and particle deformability. We then highlight the inverse situation and describe the effect of the suspended particles acting on the fluid in a channel flow. Finally, we discuss the importance of structured channels, i.e. channels with boundary conditions that vary in the streamwise direction, and their potential as a means to achieve unprecedented three-dimensional control over fluid and particles in microchannels. Ultimately, we hope that an improved fundamental and quantitative understanding of inertial fluid dynamic effects can lead to unprecedented capabilities to program fluid and particle flow towards automation of biomedicine, materials synthesis, and chemical process control.

The pdf approach to turbulent polydispersed two-phase flows

NASA Astrophysics Data System (ADS)

Minier, Jean-Pierre; Peirano, Eric

2001-10-01

The purpose of this paper is to develop a probabilistic approach to turbulent polydispersed two-phase flows. The two-phase flows considered are composed of a continuous phase, which is a turbulent fluid, and a dispersed phase, which represents an ensemble of discrete particles (solid particles, droplets or bubbles). Gathering the difficulties of turbulent flows and of particle motion, the challenge is to work out a general modelling approach that meets three requirements: to treat accurately the physically relevant phenomena, to provide enough information to address issues of complex physics (combustion, polydispersed particle flows, …) and to remain tractable for general non-homogeneous flows. The present probabilistic approach models the statistical dynamics of the system and consists in simulating the joint probability density function (pdf) of a number of fluid and discrete particle properties. A new point is that both the fluid and the particles are included in the pdf description. The derivation of the joint pdf model for the fluid and for the discrete particles is worked out in several steps. The mathematical properties of stochastic processes are first recalled. The various hierarchies of pdf descriptions are detailed and the physical principles that are used in the construction of the models are explained. The Lagrangian one-particle probabilistic description is developed first for the fluid alone, then for the discrete particles and finally for the joint fluid and particle turbulent systems. In the case of the probabilistic description for the fluid alone or for the discrete particles alone, numerical computations are presented and discussed to illustrate how the method works in practice and the kind of information that can be extracted from it. Comments on the current modelling state and propositions for future investigations which try to link the present work with other ideas in physics are made at the end of the paper.

Work-based physiological assessment of physically-demanding trades: a methodological overview.

PubMed

Taylor, Nigel A S; Groeller, Herb

2003-03-01

Technological advances, modified work practices, altered employment strategies, work-related injuries, and the rise in work-related litigation and compensation claims necessitate ongoing trade analysis research. Such research enables the identification and development of gender- and age-neutral skills, physiological attributes and employment standards required to satisfactorily perform critical trade tasks. This paper overviews a methodological approach which may be adopted when seeking to establish trade-specific physiological competencies for physically-demanding trades (occupations). A general template is presented for conducting a trade analyses within physically-demanding trades, such as those encountered within military or emergency service occupations. Two streams of analysis are recommended: the trade analysis and the task analysis. The former involves a progressive dissection of activities and skills into a series of specific tasks (elements), and results in a broad approximation of the types of trade duties, and the links between trade tasks. The latter, will lead to the determination of how a task is performed within a trade, and the physiological attributes required to satisfactorily perform that task. The approach described within this paper is designed to provide research outcomes which have high content, criterion-related and construct validities.

Combined Diet and Physical Activity Promotion Programs for Prevention of Diabetes: Community Preventive Services Task Force Recommendation Statement.

PubMed

Pronk, Nicolaas P; Remington, Patrick L

2015-09-15

Community Preventive Services Task Force recommendation on the use of combined diet and physical activity promotion programs to reduce progression to type 2 diabetes in persons at increased risk. The Task Force commissioned an evidence review that assessed the benefits and harms of programs to promote and support individual improvements in diet, exercise, and weight and supervised a review on the economic efficiency of these programs in clinical trial, primary care, and primary care-referable settings. Adolescents and adults at increased risk for progression to type 2 diabetes. The Task Force recommends the use of combined diet and physical activity promotion programs by health care systems, communities, and other implementers to provide counseling and support to clients identified as being at increased risk for type 2 diabetes. Economic evidence indicates that these programs are cost-effective.

IMPETUS - Interactive MultiPhysics Environment for Unified Simulations.

PubMed

Ha, Vi Q; Lykotrafitis, George

2016-12-08

We introduce IMPETUS - Interactive MultiPhysics Environment for Unified Simulations, an object oriented, easy-to-use, high performance, C++ program for three-dimensional simulations of complex physical systems that can benefit a large variety of research areas, especially in cell mechanics. The program implements cross-communication between locally interacting particles and continuum models residing in the same physical space while a network facilitates long-range particle interactions. Message Passing Interface is used for inter-processor communication for all simulations. Copyright © 2016 Elsevier Ltd. All rights reserved.

SHAREv2: fluctuations and a comprehensive treatment of decay feed-down

NASA Astrophysics Data System (ADS)

Torrieri, G.; Jeon, S.; Letessier, J.; Rafelski, J.

2006-11-01

This the user's manual for SHARE version 2. SHARE [G. Torrieri, S. Steinke, W. Broniowski, W. Florkowski, J. Letessier, J. Rafelski, Comput. Phys. Comm. 167 (2005) 229] (Statistical Hadronization with Resonances) is a collection of programs designed for the statistical analysis of particle production in relativistic heavy-ion collisions. While the structure of the program remains similar to v1.x, v2 provides several new features such as evaluation of statistical fluctuations of particle yields, and a greater versatility, in particular regarding decay feed-down and input/output structure. This article describes all the new features, with emphasis on statistical fluctuations. Program summaryTitle of program:SHAREv2 Catalogue identifier:ADVD_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/ADVD_v2_0 Program obtainable from: CPC Program Library, Queen's University of Belfast, N. Ireland Computer:PC, Pentium III, 512 MB RAM not hardware dependent Operating system:Linux: RedHat 6.1, 7.2, FEDORA, etc. not system dependent Programming language:FORTRAN77 Size of the package:167 KB directory, without libraries (see http://wwwasdoc.web.cern.ch/wwwasdoc/minuit/minmain.html, http://wwwasd.web.cern.ch/wwwasd/cernlib.html for details on library requirements) Number of lines in distributed program, including test data, etc.:26 101 Number of bytes in distributed program, including test data, etc.:170 346 Distribution format:tar.gzip file Computer:Any computer with an f77 compiler Nature of the physical problem:Event-by-event fluctuations have been recognized to be the physical observable capable to constrain particle production models. Therefore, consideration of event-by-event fluctuations is required for a decisive falsification or constraining of (variants of) particle production models based on (grand-, micro-) canonical statistical mechanics phase space, the so called statistical hadronization models (SHM). As in the case of particle yields, to properly compare model calculations to data it is necessary to consistently take into account resonance decays. However, event-by-event fluctuations are more sensitive than particle yields to experimental acceptance issues, and a range of techniques needs to be implemented to extract 'physical' fluctuations from an experimental event-by-event measurement. Method of solving the problem:The techniques used within the SHARE suite of programs [G. Torrieri, S. Steinke, W. Broniowski, W. Florkowski, J. Letessier, J. Rafelski, Comput. Phys. Comm. 167 (2005) 229; SHAREv1] are updated and extended to fluctuations. A full particle data-table, decay tree, and set of experimental feed-down coefficients are provided. Unlike SHAREv1.x, experimental acceptance feed-down coefficients can be entered for any resonance decay. SHAREv2 can calculate yields, fluctuations, and bulk properties of the fireball from provided thermal parameters; alternatively, parameters can be obtained from fits to experimental data, via the MINUIT fitting algorithm [F. James, M. Roos, Comput. Phys. Comm. 10 (1975) 343]. Fits can also be analyzed for significance, parameter and data point sensitivity. Averages and fluctuations at freeze-out of both the stable particles and the hadronic resonances are set according to a statistical prescription, calculated via a series of Bessel functions, using CERN library programs. We also have the option of including finite particle widths of the resonances. A χ minimization algorithm, also from the CERN library programs, is used to perform and analyze the fit. Please see SHAREv1 for more details on these. Purpose:The vast amount of high quality soft hadron production data, from experiments running at the SPS, RHIC, in past at the AGS, and in the near future at the LHC, offers the opportunity for statistical particle production model falsification. This task has turned out to be difficult when considering solely particle yields addressed in the context of SHAREv1.x. For this reason physical conditions at freeze-out remain contested. Inclusion in the analysis of event-by-event fluctuations appears to resolve this issue. Similarly, a thorough analysis including both fluctuations and average multiplicities gives a way to explore the presence and strength of interactions following hadronization (when hadrons form), ending with thermal freeze-out (when all interactions cease). SHAREv2 with fluctuations will also help determine which statistical ensemble (if any), e.g., canonical or grand-canonical, is more physically appropriate for analyzing a given system. Together with resonances, fluctuations can also be used for a direct estimate of the extent the system re-interacts between chemical and thermal freeze-out. We hope and expect that SHAREv2 will contribute to decide if any of the statistical hadronization model variants has a genuine physical connection to hadron particle production. Computation time survey:We encounter, in the FORTRAN version computation, times up to seconds for evaluation of particle yields. These rise by up to a factor of 300 in the process of minimization and a further factor of a few when χ/N profiles and contours with chemical non-equilibrium are requested. Summary of new features (w.r.t. SHAREv1.x)Fluctuations:In addition to particle yields, ratios and bulk quantities SHAREv2 can calculate, fit and analyze statistical fluctuations of particles and particle ratios Decays:SHAREv2 has the flexibility to account for any experimental method of allowing for decay feed-downs to the particle yields Charm flavor:Charmed particles have been added to the decay tree, allowing as an option study of statistical hadronization of J/ψ, χ, D, etc. Quark chemistry:Chemical non-equilibrium yields for both u and d flavors, as opposed to generically light quarks q, are considered; η- η mixing, etc., are properly dealt with, and chemical non-equilibrium can be studied for each flavor separately Misc:Many new commands and features have been introduced and added to the basic user interface. For example, it is possible to study combinations of particles and their ratios. It is also possible to combine all the input files into one file. SHARE compatibility and manual:This write-up is an update and extension of SHAREv1. The user should consult SHAREv1 regarding the principles of user interface and for all particle yield related physics and program instructions, other than the parameter additions and minor changes described here. SHAREv2 is downward compatible for the changes of the user interface, offering the user of SHAREv1 a computer generated revised input files compatible with SHAREv2.

Fixation and chemical analysis of single fog and rain droplets

NASA Astrophysics Data System (ADS)

Kasahara, M.; Akashi, S.; Ma, C.-J.; Tohno, S.

Last decade, the importance of global environmental problems has been recognized worldwide. Acid rain is one of the most important global environmental problems as well as the global warming. The grasp of physical and chemical properties of fog and rain droplets is essential to make clear the physical and chemical processes of acid rain and also their effects on forests, materials and ecosystems. We examined the physical and chemical properties of single fog and raindrops by applying fixation technique. The sampling method and treatment procedure to fix the liquid droplets as a solid particle were investigated. Small liquid particles like fog droplet could be easily fixed within few minutes by exposure to cyanoacrylate vapor. The large liquid particles like raindrops were also fixed successively, but some of them were not perfect. Freezing method was applied to fix the large raindrops. Frozen liquid particles existed stably by exposure to cyanoacrylate vapor after freezing. The particle size measurement and the elemental analysis of the fixed particle were performed in individual base using microscope, and SEX-EDX, particle-induced X-ray emission (PIXE) and micro-PIXE analyses, respectively. The concentration in raindrops was dependent upon the droplet size and the elapsed time from the beginning of rainfall.

Physics, mathematics and numerics of particle adsorption on fluid interfaces

NASA Astrophysics Data System (ADS)

Schmuck, Markus; Pavliotis, Grigorios A.; Kalliadasis, Serafim

2012-11-01

We study two arbitrary immiscible fuids where one phase contains small particles of the size of the interface and smaller. We primarily focus on charge-free particles with wetting characteristics described by the contact angle formed at the interface between the two phases and the particles. Based on the experimental observation that particles are adsorbed on the interface to reduce the interfacial energy and hence the surface tension as well, we formulate a free-energy functional that accounts for these physical effects. Using elements from calculus of variations and formal gradient flow theory, we derive partial differential equations describing the location of the interface and the density of the particles in the fluid phases. Via numerical experiments we analyse the time evolution of the surface tension, the particle concentration, and the free energy over time and reflect basic experimentally observed phenomena.

Physical characteristics of indigestible solids affect emptying from the fasting human stomach.

PubMed Central

Meyer, B; Beglinger, C; Neumayer, M; Stalder, G A

1989-01-01

Gastric emptying of indigestible solids depends on their size. It is not clear whether physical characteristics other than particle size affect emptying of indigestible solids from the fasting human stomach. We studied gastric emptying of three differently shaped particles, (cubes, spheres, rods) of either hard or soft consistency during the fasting state in human volunteers. The shape of indigestible particles did not affect their emptying. The area under the gastric emptying curve (AUC: particles x hour) was for hard cubes 24.7 (2.2), for hard spheres 27.9 (1.6), for hard rods 26.9 (2.7). All soft particles emptied faster than their identically shaped hard counterparts, but there was no difference among the three shapes (AUC for soft cubes: 29.2 (3.0), for soft spheres 32.0 (1.8), for soft rods 34.1 (1.2). If gastric emptying of hard and soft particles was compared independently of their shape, soft particles emptied significantly faster than hard ones: AUC 31.8 (1.2) v 26.5 (1.3) (p less than 0.01). In conclusion, the consistency but not the shape significantly affects gastric emptying. Specific physical characteristics other than size and shape may affect gastric emptying of indigestible particles which may be of importance in the design of drugs. PMID:2599438

Will there be energy frontier colliders after LHC?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shiltsev, Vladimir

2016-09-15

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). The future of the world-wide HEP community critically depends on the feasibility of possible post-LHC colliders. The concept of the feasibility is complex and includes at least three factors: feasibility of energy, feasibility of luminosity and feasibility of cost. Here we overview all current options for post-LHC collidersmore » from such perspective (ILC, CLIC, Muon Collider, plasma colliders, CEPC, FCC, HE-LHC) and discuss major challenges and accelerator R&D required to demonstrate feasibility of an energy frontier accelerator facility following the LHC. We conclude by taking a look into ultimate energy reach accelerators based on plasmas and crystals, and discussion on the perspectives for the far future of the accelerator-based particle physics.« less

Astroparticle physics and cosmology.

PubMed

Mitton, Simon

2006-05-20

Astroparticle physics is an interdisciplinary field that explores the connections between the physics of elementary particles and the large-scale properties of the universe. Particle physicists have developed a standard model to describe the properties of matter in the quantum world. This model explains the bewildering array of particles in terms of constructs made from two or three quarks. Quarks, leptons, and three of the fundamental forces of physics are the main components of this standard model. Cosmologists have also developed a standard model to describe the bulk properties of the universe. In this new framework, ordinary matter, such as stars and galaxies, makes up only around 4% of the material universe. The bulk of the universe is dark matter (roughly 23%) and dark energy (about 73%). This dark energy drives an acceleration that means that the expanding universe will grow ever larger. String theory, in which the universe has several invisible dimensions, might offer an opportunity to unite the quantum description of the particle world with the gravitational properties of the large-scale universe.

Students' Perceptions of Motivational Climate and Enjoyment in Finnish Physical Education: A Latent Profile Analysis.

PubMed

Jaakkola, Timo; Wang, C K John; Soini, Markus; Liukkonen, Jarmo

2015-09-01

The purpose of this study was to identify student clusters with homogenous profiles in perceptions of task- and ego-involving, autonomy, and social relatedness supporting motivational climate in school physical education. Additionally, we investigated whether different motivational climate groups differed in their enjoyment in PE. Participants of the study were 2 594 girls and 1 803 boys, aged 14-15 years. Students responded to questionnaires assessing their perception of motivational climate and enjoyment in physical education. Latent profile analyses produced a five-cluster solution labeled 1) 'low autonomy, relatedness, task, and moderate ego climate' group', 2) 'low autonomy, relatedness, and high task and ego climate, 3) 'moderate autonomy, relatedness, task and ego climate' group 4) 'high autonomy, relatedness, task, and moderate ego climate' group, and 5) 'high relatedness and task but moderate autonomy and ego climate' group. Analyses of variance showed that students in clusters 4 and 5 perceived the highest level of enjoyment whereas students in cluster 1 experienced the lowest level of enjoyment. The results showed that the students' perceptions of various motivational climates created differential levels of enjoyment in PE classes. Key pointsLatent profile analyses produced a five-cluster solution labeled 1) 'low autonomy, relatedness, task, and moderate ego climate' group', 2) 'low autonomy, relatedness, and high task and ego climate, 3) 'moderate autonomy, relatedness, task and ego climate' group 4) 'high autonomy, relatedness, task, and moderate ego climate' group, and 5) 'high relatedness and task but moderate autonomy and ego climate' group.Analyses of variance showed that clusters 4 and 5 perceived the highest level of enjoyment whereas cluster 1 experienced the lowest level of enjoyment. The results showed that the students' perceptions of motivational climate create differential levels of enjoyment in PE classes.

Affect Response to Simulated Information Attack during Complex Task Performance

DTIC Science & Technology

2014-12-02

AND FRUSTRATION ........................ 42 FIGURE 27. TASK LOAD INDEX OF MENTAL DEMAND, TEMPORAL DEMAND, AND PHYSICAL DEMAND...situational awareness, affect, and trait characteristics interact with human performance during cyberspace attacks in the physical and information...Operator state was manipulated using emotional stimulation portrayed through the presentation of video segments. The effect of emotions on

Extension of the XGC code for global gyrokinetic simulations in stellarator geometry

NASA Astrophysics Data System (ADS)

Cole, Michael; Moritaka, Toseo; White, Roscoe; Hager, Robert; Ku, Seung-Hoe; Chang, Choong-Seock

2017-10-01

In this work, the total-f, gyrokinetic particle-in-cell code XGC is extended to treat stellarator geometries. Improvements to meshing tools and the code itself have enabled the first physics studies, including single particle tracing and flux surface mapping in the magnetic geometry of the heliotron LHD and quasi-isodynamic stellarator Wendelstein 7-X. These have provided the first successful test cases for our approach. XGC is uniquely placed to model the complex edge physics of stellarators. A roadmap to such a global confinement modeling capability will be presented. Single particle studies will include the physics of energetic particles' global stochastic motions and their effect on confinement. Good confinement of energetic particles is vital for a successful stellarator reactor design. These results can be compared in the core region with those of other codes, such as ORBIT3d. In subsequent work, neoclassical transport and turbulence can then be considered and compared to results from codes such as EUTERPE and GENE. After sufficient verification in the core region, XGC will move into the stellarator edge region including the material wall and neutral particle recycling.

Excitation of Nuclei and Atoms Trapping in Optical Fields of High Intensity

DTIC Science & Technology

2006-11-01

the new relativistic wave equation for half- spin particle interacting with the electromagnetic field. The proposed equation is Lorentz and gauge ...CONTENTS Task 1. Gamma-ray laser with hidden inversion of nuclear state populations 3 Introduction 3 Recoil-accompanied nuclear...31 Task 2. Extended ensemble of monoenergetic atoms 33 Introduction 33 Results 37 Conclusion 66

The Use Of Computational Human Performance Modeling As Task Analysis Tool

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacuqes Hugo; David Gertman

2012-07-01

During a review of the Advanced Test Reactor safety basis at the Idaho National Laboratory, human factors engineers identified ergonomic and human reliability risks involving the inadvertent exposure of a fuel element to the air during manual fuel movement and inspection in the canal. There were clear indications that these risks increased the probability of human error and possible severe physical outcomes to the operator. In response to this concern, a detailed study was conducted to determine the probability of the inadvertent exposure of a fuel element. Due to practical and safety constraints, the task network analysis technique was employedmore » to study the work procedures at the canal. Discrete-event simulation software was used to model the entire procedure as well as the salient physical attributes of the task environment, such as distances walked, the effect of dropped tools, the effect of hazardous body postures, and physical exertion due to strenuous tool handling. The model also allowed analysis of the effect of cognitive processes such as visual perception demands, auditory information and verbal communication. The model made it possible to obtain reliable predictions of operator performance and workload estimates. It was also found that operator workload as well as the probability of human error in the fuel inspection and transfer task were influenced by the concurrent nature of certain phases of the task and the associated demand on cognitive and physical resources. More importantly, it was possible to determine with reasonable accuracy the stages as well as physical locations in the fuel handling task where operators would be most at risk of losing their balance and falling into the canal. The model also provided sufficient information for a human reliability analysis that indicated that the postulated fuel exposure accident was less than credible.« less

Optical knots and contact geometry II. From Ranada dyons to transverse and cosmetic knots

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kholodenko, Arkady L., E-mail: string@clemson.edu

2016-08-15

Some time ago Ranada (1989) obtained new nontrivial solutions of the Maxwellian gauge fields without sources. These were reinterpreted in Kholodenko (2015) [10] (part I) as particle-like (monopoles, dyons, etc.). They were obtained by the method of Abelian reduction of the non-Abelian Yang–Mills functional. The developed method uses instanton-type calculations normally employed for the non-Abelian gauge fields. By invoking the electric–magnetic duality it then becomes possible to replace all known charges/masses by the particle-like solutions of the source-free Abelian gauge fields. To employ these results in high energy physics, it is essential to extend Ranada’s results by carefully analyzing and classifying all dynamicallymore » generated knotted/linked structures in gauge fields, including those discovered by Ranada. This task is completed in this work. The study is facilitated by the recent progress made in solving the Moffatt conjecture. Its essence is stated as follows: in steady incompressible Euler-type fluids the streamlines could have knots/links of all types. By employing the correspondence between the ideal hydrodynamics and electrodynamics discussed in part I and by superimposing it with the already mentioned method of Abelian reduction, it is demonstrated that in the absence of boundaries only the iterated torus knots and links could be dynamically generated. Obtained results allow to develop further particle-knot/link correspondence studied in Kholodenko (2015) [13].« less

Analog assessment of frustration tolerance: association with self-reported child abuse risk and physiological reactivity.

PubMed

Rodriguez, Christina M; Russa, Mary Bower; Kircher, John C

2015-08-01

Although frustration has long been implicated in promoting aggression, the potential for poor frustration tolerance to function as a risk factor for physical child abuse risk has received minimal attention. Instead, much of the extant literature has examined the role of anger in physical abuse risk, relying on self-reports of the experience or expression of anger, despite the fact that this methodology is often acknowledged as vulnerable to bias. Therefore, the present investigation examined whether a more implicit, analog assessment of frustration tolerance specifically relevant to parenting would reveal an association with various markers of elevated physical child abuse risk in a series of samples that varied with regard to age, parenting status, and abuse risk. An analog task was designed to evoke parenting-relevant frustration: the task involved completing an unsolvable task while listening to a crying baby or a toddler's temper tantrum; time scores were generated to gauge participants' persistence in the task when encountering such frustration. Across these studies, low frustration tolerance was associated with increased physical child abuse potential, greater use of parent-child aggression in discipline encounters, dysfunctional disciplinary style, support for physical discipline use and physical discipline escalation, and increased heart rate. Future research directions that could better inform intervention and prevention programs are discussed, including working to clarify the processes underlying frustration intolerance and potential interactive influences that may exacerbate physical child abuse. Copyright © 2015 Elsevier Ltd. All rights reserved.

Experimentally Manipulated Somatic Information and Somatization Tendencies and their Impact on Physical Symptom Reporting and Performance in a Physically Strenuous Task

PubMed Central

CASTO, KATHLEEN; LECCI, LEN

2012-01-01

This study attempts to determine whether the presentation of an experimentally manipulated somatic experience during a physically strenuous task can influence physical performance and symptom reporting. The study also compares the relative influence of experimentally manipulated somatic information (state somatization) with stable individual differences in the tendency to amplify physical symptoms (trait somatization) on performance and symptom reporting. 194 participants completed standardized measures of somatization tendencies, state anxiety, neuroticism and conscientiousness. Participants where then given a mock physical exam, with individuals randomly assigned to receive either favorable or unfavorable somatic information. All participants then had their body mass index assessed and completed a rigorous exercise task, with quantification of performance. Physiological measures of blood pressure and pulse were also assessed before and after the exercise task. The experimentally manipulated presentation of somatic information predicted both performance and physical symptoms, even after controlling for BMI, neuroticism, conscientiousness, and state anxiety. Moreover, expected performance uniquely and significantly predicted performance above and beyond condition, anxiety, BMI, neuroticism, and conscientiousness. Somatosensory amplification tendencies also predicted symptom endorsement, but not performance. Findings suggest that both state and trait expectations with respect to somatic experiences influence symptom reporting and to a lesser extent performance, even after controlling for variables known to strongly influence each of these outcomes. Results are consistent with the cognitive-perceptual and the cognitive-appraisal models of somatic interpretation. PMID:27182375

Identity of Particles and Continuum Hypothesis

NASA Astrophysics Data System (ADS)

Berezin, Alexander A.

2001-04-01

Why all electrons are the same? Unlike other objects, particles and atoms (same isotopes) are forbidden to have individuality or personal history (or reveal their hidden variables, even if they do have them). Or at least, what we commonly call physics so far was unable to disprove particle's sameness (Berezin and Nakhmanson, Physics Essays, 1990). Consider two opposing hypotheses: (A) particles are indeed absolutely same, or (B) they do have individuality, but it is beyond our capacity to demonstrate. This dilemma sounds akin to undecidability of Continuum Hypothesis of existence (or not) of intermediate cardinalities between integers and reals (P.Cohen). Both yes and no of it are true. Thus, (alleged) sameness of electrons and atoms may be a physical translation (embodiment) of this fundamental Goedelian undecidability. Experiments unlikely to help: even if we find that all electrons are same within 30 decimal digits, could their masses (or charges) still differ in100-th digit? Within (B) personalized informationally rich (infinitely rich?) digital tails (starting at, say, 100-th decimal) may carry individual record of each particle history. Within (A) parameters (m, q) are indeed exactly same in all digits and their sameness is based on some inherent (meta)physical principle akin to Platonism or Eddington-type numerology.

Combustion Of Porous Graphite Particles In Oxygen Enriched Air

NASA Technical Reports Server (NTRS)

Delisle, Andrew J.; Miller, Fletcher J.; Chelliah, Harsha K.

2003-01-01

Combustion of solid fuel particles has many important applications, including power generation and space propulsion systems. The current models available for describing the combustion process of these particles, especially porous solid particles, include various simplifying approximations. One of the most limiting approximations is the lumping of the physical properties of the porous fuel with the heterogeneous chemical reaction rate constants [1]. The primary objective of the present work is to develop a rigorous modeling approach that could decouple such physical and chemical effects from the global heterogeneous reaction rates. For the purpose of validating this model, experiments with porous graphite particles of varying sizes and porosity are being performed under normal and micro gravity.

Energy peaks: A high energy physics outlook

NASA Astrophysics Data System (ADS)

Franceschini, Roberto

2017-12-01

Energy distributions of decay products carry information on the kinematics of the decay in ways that are at the same time straightforward and quite hidden. I will review these properties and discuss their early historical applications, as well as more recent ones in the context of (i) methods for the measurement of masses of new physics particle with semi-invisible decays, (ii) the characterization of Dark Matter particles produced at colliders, (iii) precision mass measurements of Standard Model particles, in particular of the top quark. Finally, I will give an outlook of further developments and applications of energy peak method for high energy physics at colliders and beyond.

Shoichi Sakata: His Life and Physics ---Collections of Materials in Sakata Memorial Archival Library---

NASA Astrophysics Data System (ADS)

Tanabashi, M.

Shoichi Sakata and his Nagoya School made a lot of important achievements at the predawn of the particle physics revolution. The ``two-meson'' theory (introduction of the second generation leptons), the ``C-meson theory'' (a theory which inspired Tomonaga's renormalization theory), the ``Sakata model'' (a precursor to the quark model), and the ``Maki-Nakagawa-Sakata'' theory on the neutrino mixings are among them. These outputs are now regarded as essential ingredients in modern particle physics. Sakata also took his leadership in setting up democratic administration system in his theoretical particle physics group (E-ken). It was this democratic atmosphere in which many excellent physicists were brought up as Sakata's diciples. In this talk, I introduce Sakata and his achievements in physics, showing various materials archived in the Sakata Memorial Archival Library (SMAL), an archival repository of primary material showing Sakata's activities. These SMAL documents vividly show Sakata's way of thinking in his approach to the new physics.

USPAS | U.S. Particle Accelerator School

Science.gov Websites

U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School Education in Beam Physics and Accelerator Technology Home About About University Credits Joint International Accelerator School University-Style Programs Symposium-Style Programs

The Role of Physical Fitness in the Neurocognitive Performance of Task Switching in Older Persons with Mild Cognitive Impairment.

PubMed

Tsai, Chia-Liang; Pai, Ming-Chyi; Ukropec, Jozef; Ukropcová, Barbara

2016-04-23

Although elderly people with amnestic mild cognitive impairment (aMCI) have been found to show impaired behavioral performance in task switching, no research has yet explored the electrophysiological mechanisms and the potential correlation between physical fitness and neurocognitive (i.e., behavioral and electrophysiological) performance in aMCI. The present study was thus aimed to examine whether there are differences in electrophysiological (i.e., event-related potential) performance between aMCI participants and controls when performing a task-switching paradigm, and to investigate the role of physical fitness in the relationship between neurocognitive performance and aMCI. Sixty participants were classified into aMCI (n = 30) and control (n = 30) groups, and performed a task-switching paradigm with concomitant electrophysiological recording, as well as underwent senior functional physical fitness tests. The aMCI group showed comparable scores on most parts of the physical fitness tests, but reduced lower body flexibility and VO2max as compared to the control group. When performing the task-switching paradigm, the aMCI group showed slower reaction times in the heterogeneous condition and larger global switching costs, although no significant difference was observed in accuracy rates between the two groups. In addition, the aMCI group showed significantly prolonged P3 latencies in the homogeneous and heterogeneous conditions, and a smaller P3 amplitude only in the heterogeneous condition. The level of cardiorespiratory fitness was significantly correlated with P3 amplitude in the aMCI group, particularly in the heterogeneous condition of the task-switching paradigm. These results show that the aMCI group exhibited abnormalities in their neurocognitive performance when performing the task-switching paradigm and such a deficit was likely associated with reduced cardiorespiratory fitness, which was shown to be the important predictor of neurocognitive performance.

Physical and biological studies of coal and oil fly ash.

PubMed Central

Fisher, G L; McNeill, K L; Prentice, B A; McFarland, A R

1983-01-01

Studies were performed to compare the physical and chemical characteristics and the in vitro macrophage cytotoxicity of oil and coal fly ash. Sampling methodology was developed to collect size-fractionated particulate matter from the smokestack of either a coal-fired or an oil-fired power plant. Morphological studies demonstrated particle heterogeneity, although most coal fly ash particles appeared to be spherical. Oil fly ash contained two major morphologies; nonopaque amorphous particles and opaque amorphous particles. Elemental analysis indicates that the coal ash is predominantly composed of aluminosilicate particles, while the oil ash is predominantly inorganic sulfates and carbonaceous particles. In vitro macrophage assays demonstrate that the finest coal fly ash particles are the most cytotoxic; the cytotoxicity is significantly less than that of alpha-quartz, the positive control particle. In contrast, the oil fly ash particles are more cytotoxic than quartz. The cytotoxicity of oil fly ash is due to soluble components, possibly vanadium salts. Images FIGURE 2. A FIGURE 2. B FIGURE 2. C FIGURE 2. D PMID:6641653

A demonstration of particle duality of light

NASA Astrophysics Data System (ADS)

Jiang, Haili; Liu, Zhihai; Sun, Qiuhua; Zhao, Yancheng

2017-08-01

The need of understanding and teaching about wave-particle duality if light with gets more and more apparent in the background of the attention of modern physics. As early as the beginning of twentieth Century, Einstein dared to "deny" the development of a very perfect light electromagnetic theory, so that the quantum of light can be developed. In 1924, De Broglie put forward wave-particle duality if light to other micro particles and the concept of matter wave, pointed out that all micro particle has wave-particle duality. This is a very abstract concept for students, most college physics teaching all lack of demonstration about particle duality of light. The present article aims to contribute to demonstrate the wave-particle duality of light at the same time using a simple way based on fiber optical tweezers. It is hoped that useful lesson can be absorbed so that students can deepen the understanding of the particle and wave properties of light. To complement the demonstration experiment for this attribute light has momentum.

Multi-Parameter Scattering Sensor and Methods

NASA Technical Reports Server (NTRS)

Greenberg, Paul S. (Inventor); Fischer, David G. (Inventor)

2016-01-01

Methods, detectors and systems detect particles and/or measure particle properties. According to one embodiment, a detector for detecting particles comprises: a sensor for receiving radiation scattered by an ensemble of particles; and a processor for determining a physical parameter for the detector, or an optimal detection angle or a bound for an optimal detection angle, for measuring at least one moment or integrated moment of the ensemble of particles, the physical parameter, or detection angle, or detection angle bound being determined based on one or more of properties (a) and/or (b) and/or (c) and/or (d) or ranges for one or more of properties (a) and/or (b) and/or (c) and/or (d), wherein (a)-(d) are the following: (a) is a wavelength of light incident on the particles, (b) is a count median diameter or other characteristic size parameter of the particle size distribution, (c) is a standard deviation or other characteristic width parameter of the particle size distribution, and (d) is a refractive index of particles.

Shock Interaction of Metal Particles in Condensed Explosive Detonation

NASA Astrophysics Data System (ADS)

Ripley, Robert; Zhang, Fan; Lien, Fue-Sang

2005-07-01

For detonation propagation in a condensed explosive with metal particles, a macro-scale physical model describing the momentum transfer between the explosive and particles has yet to be completely established. Previous 1D and 2D meso-scale modeling studies indicated that significant momentum transfer from the explosive to the particles occurs as the leading shock front crosses the particles, thus influencing the initiation and detonation structure. In this work, 3D meso-scale modeling is conducted to further study the two-phase momentum transfer during the shock diffraction and subsequent detonation in liquid nitromethane containing packed metal particles. Detonation of the condensed explosive is computed using an Arrhenius reaction model and a hybrid EOS model that combines the Mie-Gruneisen equation for reactants and the JWL equation for products. The compressible particles are modeled using the Tait EOS, where the material strength is negligible. The effect of particle packing configuration and inter-particle spacing is shown by parametric studies. Finally, a physical description of the momentum transfer is discussed.

Magnetic particle motions within living cells. Physical theory and techniques.

PubMed Central

Valberg, P A; Butler, J P

1987-01-01

Body tissues are not ferromagnetic, but ferromagnetic particles can be present as contaminants or as probes in the lungs and in other organs. The magnetic domains of these particles can be aligned by momentary application of an external magnetic field; the magnitude and time course of the resultant remanent field depend on the quantity of magnetic material and the degree of particle motion. The interpretation of magnetometric data requires an understanding of particle magnetization, agglomeration, random motion, and both rotation and translation in response to magnetic fields. We present physical principles relevant to magnetometry and suggest models for intracellular particle motion driven by thermal, elastic, or cellular forces. The design principles of instrumentation for magnetizing intracellular particles and for detecting weak remanent magnetic fields are described. Such magnetic measurements can be used for noninvasive studies of particle clearance from the body or of particle motion within body tissues and cells. Assumptions inherent to this experimental approach and possible sources of artifact are considered and evaluated. PMID:3676435

Adsorption-desorption kinetics of soft particles onto surfaces

NASA Astrophysics Data System (ADS)

Osberg, Brendan; Gerland, Ulrich

A broad range of physical, chemical, and biological systems feature processes in which particles randomly adsorb on a substrate. Theoretical models usually assume ``hard'' (mutually impenetrable) particles, but in soft matter physics the adsorbing particles can be effectively compressible, implying ``soft'' interaction potentials. We recently studied the kinetics of such soft particles adsorbing onto one-dimensional substrates, identifying three novel phenomena: (i) a gradual density increase, or ''cramming'', replaces the usual jamming behavior of hard particles, (ii) a density overshoot, can occur (only for soft particles) on a time scale set by the desorption rate, and (iii) relaxation rates of soft particles increase with particle size (on a lattice), while hard particles show the opposite trend. The latter occurs since unjamming requires desorption and many-bodied reorganization to equilibrate -a process that is generally very slow. Here we extend this analysis to a two-dimensional substrate, focusing on the question of whether the adsorption-desorption kinetics of particles in two dimensions is similarly enriched by the introduction of soft interactions. Application to experiments, for example the adsorption of fibrinogen on two-dimensional surfaces, will be discussed.

An Inexpensive Cosmic Ray Detector for the Classroom

ERIC Educational Resources Information Center

Goldader, Jeffrey D.; Choi, Seulah

2010-01-01

Finding ways to demonstrate--in a high school classroom--that subatomic particles from space produce other particles capable of reaching the Earth's surface is not a trivial task. In this paper, we describe a Geiger-Muller tube-based cosmic ray coincidence detector we produced at a total cost of less than $200, using two tubes purchased used…

Self-efficacy toward physical activity and the physical activity behavior of children with and without Developmental Coordination Disorder.

PubMed

Batey, C A; Missiuna, C A; Timmons, B W; Hay, J A; Faught, B E; Cairney, J

2014-08-01

Affecting 5-6% of children, Developmental Coordination Disorder (DCD) is a prevalent chronic condition. The nature of the disorder - impaired motor coordination - makes avoidance of physical activity (PA) common. The purpose of this study was to examine the effect of barrier and task self-efficacy on PA behavior in children with DCD and a group of typically developing (TD) children. Children were compared on their perceived ability to complete different intensities and duration of PA (task efficacy) and their confidence in completing PA when faced with everyday barriers (barrier efficacy). An accelerometer was used to record their activity over the subsequent week. Children with DCD were found to have significantly lower task efficacy and barrier efficacy. They also spent significantly less time in moderate to vigorous physical activity (MVPA). Multivariate analyses revealed that gender modified the relationship for both groups. Separate multivariate regressions, were therefore conducted by gender. A direct effect of DCD on PA was observed for boys, but not for girls. Further analyses showed that neither task efficacy nor barrier efficacy influenced the relationship between DCD and PA. Results from this study confirm that children with DCD have lower task and barrier self-efficacy than TD children and that males have lower PA levels than their TD peers; however neither task or barrier self-efficacy mediated the relationship between DCD and PA. Copyright © 2013. Published by Elsevier B.V.

Jet-images — deep learning edition

DOE PAGES

de Oliveira, Luke; Kagan, Michael; Mackey, Lester; ...

2016-07-13

Building on the notion of a particle physics detector as a camera and the collimated streams of high energy particles, or jets, it measures as an image, we investigate the potential of machine learning techniques based on deep learning architectures to identify highly boosted W bosons. Modern deep learning algorithms trained on jet images can out-perform standard physically-motivated feature driven approaches to jet tagging. We develop techniques for visualizing how these features are learned by the network and what additional information is used to improve performance. Finally, this interplay between physically-motivated feature driven tools and supervised learning algorithms is generalmore » and can be used to significantly increase the sensitivity to discover new particles and new forces, and gain a deeper understanding of the physics within jets.« less

Jet-images — deep learning edition

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Oliveira, Luke; Kagan, Michael; Mackey, Lester

Building on the notion of a particle physics detector as a camera and the collimated streams of high energy particles, or jets, it measures as an image, we investigate the potential of machine learning techniques based on deep learning architectures to identify highly boosted W bosons. Modern deep learning algorithms trained on jet images can out-perform standard physically-motivated feature driven approaches to jet tagging. We develop techniques for visualizing how these features are learned by the network and what additional information is used to improve performance. Finally, this interplay between physically-motivated feature driven tools and supervised learning algorithms is generalmore » and can be used to significantly increase the sensitivity to discover new particles and new forces, and gain a deeper understanding of the physics within jets.« less

Particle Physics in High School: A Diagnose Study

PubMed Central

Solbes, Jordi

2016-01-01

The science learning process improves when the contents are connected to students’ lives. Particle physics has had a great impact in our society in the last years and has changed the theoretical picture about matter fundamental dynamics. Thus, we think that academic contents about matter components and interactions should be updated. With this study we aim to characterize the level of knowledge of high school students about this topic. We built a test with questions about classical atomic models, particle physics, recent discoveries, social implications and students opinions about it. Contrary to our first suspicion, students’ answers show a high variability. They have new physics ideas and show a great interest towards modern concepts. We suggest including an updated view of this topic as part of the curriculum. PMID:27253377

Particle Physics in High School: A Diagnose Study.

PubMed

Tuzón, Paula; Solbes, Jordi

2016-01-01

The science learning process improves when the contents are connected to students' lives. Particle physics has had a great impact in our society in the last years and has changed the theoretical picture about matter fundamental dynamics. Thus, we think that academic contents about matter components and interactions should be updated. With this study we aim to characterize the level of knowledge of high school students about this topic. We built a test with questions about classical atomic models, particle physics, recent discoveries, social implications and students opinions about it. Contrary to our first suspicion, students' answers show a high variability. They have new physics ideas and show a great interest towards modern concepts. We suggest including an updated view of this topic as part of the curriculum.

Cosmology and particle physics

NASA Astrophysics Data System (ADS)

Barrow, J. D.

A brief overview is given of recent work that integrates cosmology and particle physics. The observational data regarding the abundance of matter and radiation in the universe is described. The manner in which the cosmological survival density of stable massive particles can be calculated is discussed along with the process of cosmological nucleosynthesis. Several applications of these general arguments are given with reference to the survival density of nucleons, neutrinos and unconfined fractionally charge particles. The use of nucleosynthesis to limit the number of lepton generations is described together with the implications of a small neutrino mass for the origin of galaxies and clusters.

Tamper resistant magnetic stripes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Naylor, R.B.; Sharp, D.J.

1999-11-09

This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180{degree} opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40 C, is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable timemore » limits.« less

Particle Detectors Subatomic Bomb Squad

ScienceCinema

Lincoln, Don

2018-01-16

The manner in which particle physicists investigate collisions in particle accelerators is a puzzling process. Using vaguely-defined “detectors,” scientists are able to somehow reconstruct the collisions and convert that information into physics measurements. In this video, Fermilab’s Dr. Don Lincoln sheds light on this mysterious technique. In a surprising analogy, he draws a parallel between experimental particle physics and bomb squad investigators and uses an explosive example to illustrate his points. Be sure to watch this video… it’s totally the bomb.

Tamper resistant magnetic stripes

DOEpatents

Naylor, Richard Brian; Sharp, Donald J.

1999-01-01

This invention relates to a magnetic stripe comprising a medium in which magnetized particles are suspended and in which the encoded information is recorded by actual physical rotation or alignment of the previously magnetized particles within the flux reversals of the stripe which are 180.degree. opposed in their magnetic polarity. The magnetized particles are suspended in a medium which is solid, or physically rigid, at ambient temperatures but which at moderately elevated temperatures, such as 40.degree. C., is thinable to a viscosity permissive of rotation of the particles therein under applications of moderate external magnetic field strengths within acceptable time limits.

Long-term habitual physical activity is associated with lower distractibility in a Stroop interference task in aging: Behavioral and ERP evidence.

PubMed

Gajewski, Patrick D; Falkenstein, Michael

2015-08-01

Aging is associated with compromised executive control functions. Several lines of evidence point to beneficial effects of physical activity on cognition which indicate that regular physical activity may counteract the age-related decline of some executive functions. Here, we investigate the effects of lifelong physical activity (about 50 years) on interference processing in two matched groups of 20 physically high active and 20 low active healthy older men using event-related potentials (ERPs). In a low interference block of the Stroop task, participants had to indicate the meaning of color-words, while color was either compatible or incompatible with the meaning. In the high interference block, participants were asked to respond according to the ink color of the word and to ignore its meaning. Physically active seniors showed faster reaction times, lower individual variability in reaction times, and higher accuracy compared to low active seniors, particularly in the high interference block. This result was confirmed in the classic paper-and-pencil version of the Stroop task showing higher interference score in the low active than high active individuals. ERPs revealed a shorter latency of the P2 and generally more negative amplitudes of the fronto-central N2 and N450 components in the high active group compared to the low active group. The amount of interference was negatively correlated with objectively measured fitness and self-reported physical activity. The positive effect of physical fitness on interference processing in the behavioral data was related to N2 and N450 amplitudes. Taken together, this suggests that seniors reporting long-term physical activity may exhibit generally enhanced activity in the frontal cortex which enables more efficient interference resolution in the Stroop task. Copyright © 2015 Elsevier Inc. All rights reserved.

The relationship between physical activity, and physical performance and psycho-cognitive functioning in older adults living in residential aged care facilities.

PubMed

Bootsman, Natalia J M; Skinner, Tina L; Lal, Ravin; Glindemann, Delma; Lagasca, Carmela; Peeters, G M E E Geeske

2018-02-01

Insight into modifiable factors related to falls risk in older adults living in residential aged care facilities (RACFs) is necessary to tailor preventive strategies for this high-risk population. Associations between physical activity (PA), physical performance and psycho-cognitive functioning have been understudied in aged care residents. This study investigated associations between PA, and both physical performance and psycho-cognitive functioning in older adults living in RACFs. Cross-sectional study. Forty-four residents aged 85±8years were recruited from four RACFs located in Southeast Queensland. PA was assessed as the average time spent walking in hours/day using activPAL3™. Physical performance tests included balance, gait speed, dual-task ability, reaction time, coordination, grip strength, and leg strength and power. Psycho-cognitive questionnaires included quality of life, balance confidence, fear of falling and cognitive functioning. Associations between PA and each outcome measure were analysed using linear or ordinal regression models. The average time spent walking was 0.5±0.4h/day. Higher levels of PA were significantly associated with better balance (compared with low PA, medium: B=1.6; high: B=1.3) and dual-task ability (OR=7.9 per 0.5h/day increase). No statistically significant associations were found between PA and the other physical and psycho-cognitive measures. More physically active residents scored higher on balance and dual-task ability, which are key predictors of falls risk. This suggests that physical activity programs targeting balance and dual-task ability could help prevent falls in aged care residents. Copyright © 2017 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.

Transforming Introductory Physics for Life Scientists: Researching the consequences for students

NASA Astrophysics Data System (ADS)

Turpen, Chandra

2011-10-01

In response to policy documents calling for dramatic changes in pre-medical and biology education [1-3], the physics and biology education research groups at the University of Maryland are rethinking how to teach physics to life science majors. As an interdisciplinary team, we are drastically reconsidering the physics topics relevant for these courses. We are designing new in-class tasks to engage students in using physical principles to explain aspects of biological phenomena where the physical principles are of consequence to the biological systems. We will present examples of such tasks as well as preliminary data on how students engage in these tasks. Lastly, we will share some barriers encountered in pursuing meaningful interdisciplinary education.[4pt] Co-authors: Edward F. Redish and Julia Svaboda [4pt] [1] National Research Council, Bio2010: Transforming Undergraduate Education for Future Research Biologists (NAP, 2003).[0pt] [2] AAMC-HHMI committee, Scientific Foundations for Future Physicians (AAMC, 2009).[0pt] [3] American Association for the Advancement of Science, Vision and Change in Undergraduate Biology Education: A Call to Action (AAAS, 2009).

Characterization of the Physical Stability of a Lyophilized IgG1 mAb After Accelerated Shipping-like Stress

PubMed Central

Telikepalli, Srivalli; Kumru, Ozan S.; Kim, Jae Hyun; Joshi, Sangeeta B.; O'Berry, Kristin B.; Blake-Haskins, Angela W.; Perkins, Melissa D.; Middaugh, C. Russell; Volkin, David B.

2014-01-01

Upon exposure to shaking stress, an IgG1 mAb formulation in both liquid and lyophilized state formed subvisible particles. Since freeze-drying is expected to minimize protein physical instability under these conditions, the extent and nature of aggregate formation in the lyophilized preparation was examined using a variety of particle characterization techniques. The effect of formulation variables such as residual moisture content, reconstitution rate, and reconstitution medium were examined. Upon reconstitution of shake-stressed lyophilized mAb, differences in protein particle size and number were observed by Microflow Digital Imaging (MFI), with the reconstitution medium having the largest impact. Shake-stress had minor effects on the structure of protein within the particles as shown by SDS-PAGE and FTIR analysis. The lyophilized mAb was shake-stressed to different extents and stored for 3 months at different temperatures. Both extent of cake collapse and storage temperature affected the physical stability of the shake-stressed lyophilized mAb upon subsequent storage. These findings demonstrate that physical degradation upon shaking of a lyophilized IgG1 mAb formulation includes not only cake breakage, but also results in an increase in subvisible particles and turbidity upon reconstitution. The shaking-induced cake breakage of the lyophilized IgG1 mAb formulation also resulted in decreased physical stability upon storage. PMID:25522000

The AAPT Advanced Laboratory Task Force Report

NASA Astrophysics Data System (ADS)

Dunham, Jeffrey

2008-04-01

In late 2005, the American Association of Physics Teachers (AAPT) assembled a seven-member Advanced Laboratory Task Force^ to recommend ways that AAPT could increase the degree and effectiveness of its interactions with physics teachers of upper-division physics laboratories, with the ultimate goal of improving the teaching of advanced laboratories. The task force completed its work during the first half of 2006 and its recommendations were presented to the AAPT Executive Committee in July 2006. This talk will present the recommendations of the task force and actions taken by AAPT in response to them. The curricular goals of the advanced laboratory course at various institutions will also be discussed. The talk will conclude with an appeal to the APS membership to support ongoing efforts to revitalize advanced laboratory course instruction. ^Members of the Advanced Laboratory Task Force: Van Bistrow, University of Chicago; Bob DeSerio, University of Florida; Jeff Dunham, Middlebury College (Chair); Elizabeth George, Wittenburg University; Daryl Preston, California State University, East Bay; Patricia Sparks, Harvey Mudd College; Gerald Taylor, James Madison University; and David Van Baak, Calvin College.

Ways of thinking: from crows to children and back again.

PubMed

Clayton, Nicola S

2015-01-01

This article reviews some of the recent work on the remarkable cognitive capacities of food-caching corvids. The focus will be on their ability to think about other minds and other times, and tool-using tests of physical problem solving. Research on developmental cognition suggests that young children do not pass similar tests until they are at least four years of age in the case of the social cognition experiments, and eight years of age in the case of the tasks that tap into physical cognition. This developmental trajectory seems surprising. Intuitively, one might have thought that the social and planning tasks required more complex forms of cognitive process, namely Mental Time Travel and Theory of Mind. Perhaps the fact that children pass these tasks earlier than the physical problem-solving tasks is a reflection of cultural influences. Future research will hope to identify these cognitive milestones by starting to develop tasks that might go some way towards understanding the mechanisms underlying these abilities in both children and corvids, to explore similarities and differences in their ways of thinking.

The Discovery of Subatomic Particles Revised Edition

NASA Astrophysics Data System (ADS)

Weinberg, Steven

2003-09-01

This commentary on the discovery of the atom's constituents provides an historical account of key events in the physics of the twentieth century that led to the discoveries of the electron, proton and neutron. Steven Weinberg introduces the fundamentals of classical physics that played crucial roles in these discoveries. Connections are shown throughout the book between the historic discoveries of subatomic particles and contemporary research at the frontiers of physics, including the most current discoveries of new elementary particles. Steven Weinberg was Higgins Professor of Physics at Harvard before moving to The University of Texas at Austin, where he founded its Theory Group. At Texas he holds the Josey Regental Chair of Science and is a member of the Physics and Astronomy Departments. His research has spanned a broad range of topics in quantum field theory, elementary particle physics, and cosmology, and has been honored with numerous awards, including the Nobel Prize in Physics, the National Medal of Science, the Heinemann Prize in Mathematical Physics, the Cresson Medal of the Franklin Institute, the Madison Medal of Princeton University, and the Oppenheimer Prize. In addition to the well-known treatise, Gravitation and Cosmololgy, he has written several books for general readers, including the prize-winning The First Three Minutes (now translated into 22 foreign languages), and most recently Dreams of a Final Theory (Pantheon Books, 1993). He has also written a textbook The Quantum Theory of Fields, Vol.I, Vol. II, and Vol. III (Cambridge).

Physical-geometric optics method for large size faceted particles.

PubMed

Sun, Bingqiang; Yang, Ping; Kattawar, George W; Zhang, Xiaodong

2017-10-02

A new physical-geometric optics method is developed to compute the single-scattering properties of faceted particles. It incorporates a general absorption vector to accurately account for inhomogeneous wave effects, and subsequently yields the relevant analytical formulas effective and computationally efficient for absorptive scattering particles. A bundle of rays incident on a certain facet can be traced as a single beam. For a beam incident on multiple facets, a systematic beam-splitting technique based on computer graphics is used to split the original beam into several sub-beams so that each sub-beam is incident only on an individual facet. The new beam-splitting technique significantly reduces the computational burden. The present physical-geometric optics method can be generalized to arbitrary faceted particles with either convex or concave shapes and with a homogeneous or an inhomogeneous (e.g., a particle with a core) composition. The single-scattering properties of irregular convex homogeneous and inhomogeneous hexahedra are simulated and compared to their counterparts from two other methods including a numerically rigorous method.

Sixfold improved single particle measurement of the magnetic moment of the antiproton.

PubMed

Nagahama, H; Smorra, C; Sellner, S; Harrington, J; Higuchi, T; Borchert, M J; Tanaka, T; Besirli, M; Mooser, A; Schneider, G; Blaum, K; Matsuda, Y; Ospelkaus, C; Quint, W; Walz, J; Yamazaki, Y; Ulmer, S

2017-01-18

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement g p /2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20.

Sixfold improved single particle measurement of the magnetic moment of the antiproton

PubMed Central

Nagahama, H.; Smorra, C.; Sellner, S.; Harrington, J.; Higuchi, T.; Borchert, M. J.; Tanaka, T.; Besirli, M.; Mooser, A.; Schneider, G.; Blaum, K.; Matsuda, Y.; Ospelkaus, C.; Quint, W.; Walz, J.; Yamazaki, Y.; Ulmer, S.

2017-01-01

Our current understanding of the Universe comes, among others, from particle physics and cosmology. In particle physics an almost perfect symmetry between matter and antimatter exists. On cosmological scales, however, a striking matter/antimatter imbalance is observed. This contradiction inspires comparisons of the fundamental properties of particles and antiparticles with high precision. Here we report on a measurement of the g-factor of the antiproton with a fractional precision of 0.8 parts per million at 95% confidence level. Our value /2=2.7928465(23) outperforms the previous best measurement by a factor of 6. The result is consistent with our proton g-factor measurement gp/2=2.792847350(9), and therefore agrees with the fundamental charge, parity, time (CPT) invariance of the Standard Model of particle physics. Additionally, our result improves coefficients of the standard model extension which discusses the sensitivity of experiments with respect to CPT violation by up to a factor of 20. PMID:28098156

Child–Adult Differences in Using Dual-Task Paradigms to Measure Listening Effort

PubMed Central

Charles, Lauren M.; Ricketts, Todd A.

2017-01-01

Purpose The purpose of the project was to investigate the effects modifying the secondary task in a dual-task paradigm to measure objective listening effort. To be specific, the complexity and depth of processing were increased relative to a simple secondary task. Method Three dual-task paradigms were developed for school-age children. The primary task was word recognition. The secondary task was a physical response to a visual probe (simple task), a physical response to a complex probe (increased complexity), or word categorization (increased depth of processing). Sixteen adults (22–32 years, M = 25.4) and 22 children (9–17 years, M = 13.2) were tested using the 3 paradigms in quiet and noise. Results For both groups, manipulations of the secondary task did not affect word recognition performance. For adults, increasing depth of processing increased the calculated effect of noise; however, for children, results with the deep secondary task were the least stable. Conclusions Manipulations of the secondary task differentially affected adults and children. Consistent with previous findings, increased depth of processing enhanced paradigm sensitivity for adults. However, younger participants were more likely to demonstrate the expected effects of noise on listening effort using a secondary task that did not require deep processing. PMID:28346816

History of the Bevatron

ScienceCinema

None

2017-12-09

This 1993 documentary chronicles the Bevatron at Berkeley Lab. During its operation from 1954 until 1993, the Bevatron was among the world's leading particle accelerators, and during the 1950s and 1960s, four Nobel Prizes were awarded for work conducted in whole or in part there. The accelerator made major contributions in four distinct areas of research: high-energy particle physics, nuclear heavy-ion physics, medical research and therapy, and space-related studies of radiation damage and heavy particles in space.

RICH detectors: Analysis methods and their impact on physics

NASA Astrophysics Data System (ADS)

Križan, Peter

2017-12-01

The paper discusses the importance of particle identification in particle physics experiments, and reviews the impact of ring imaging Cherenkov (RICH) counters in experiments that are currently running, or are under construction. Several analysis methods are discussed that are needed to calibrate a RICH counter, and to align its components with the rest of the detector. Finally, methods are reviewed on how to employ the collected data to efficiently separate one particle species from the other.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lincoln, Don

The manner in which particle physicists investigate collisions in particle accelerators is a puzzling process. Using vaguely-defined “detectors,” scientists are able to somehow reconstruct the collisions and convert that information into physics measurements. In this video, Fermilab’s Dr. Don Lincoln sheds light on this mysterious technique. In a surprising analogy, he draws a parallel between experimental particle physics and bomb squad investigators and uses an explosive example to illustrate his points. Be sure to watch this video… it’s totally the bomb.