Science.gov

Sample records for accelerator physics problems

  1. SYMMETRY, HAMILTONIAN PROBLEMS AND WAVELETS IN ACCELERATOR PHYSICS

    SciTech Connect

    FEDOROVA,A.; ZEITLIN,M.; PARSA,Z.

    2000-03-31

    In this paper the authors consider applications of methods from wavelet analysis to nonlinear dynamical problems related to accelerator physics. In this approach they take into account underlying algebraical, geometrical and topological structures of corresponding problems.

  2. Innovative Applications of Genetic Algorithms to Problems in Accelerator Physics

    SciTech Connect

    Hofler, Alicia; Terzic, Balsa; Kramer, Matthew; Zvezdin, Anton; Morozov, Vasiliy; Roblin, Yves; Lin, Fanglei; Jarvis, Colin

    2013-01-01

    The genetic algorithm (GA) is a relatively new technique that implements the principles nature uses in biological evolution in order to optimize a multidimensional nonlinear problem. The GA works especially well for problems with a large number of local extrema, where traditional methods (such as conjugate gradient, steepest descent, and others) fail or, at best, underperform. The field of accelerator physics, among others, abounds with problems which lend themselves to optimization via GAs. In this paper, we report on the successful application of GAs in several problems related to the existing CEBAF facility, the proposed MEIC at Jefferson Lab, and a radio frequency (RF) gun based injector. These encouraging results are a step forward in optimizing accelerator design and provide an impetus for application of GAs to other problems in the field. To that end, we discuss the details of the GAs used, including a newly devised enhancement, which leads to improved convergence to the optimum and make recommendations for future GA developments and accelerator applications.

  3. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-12-31

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  4. Accelerator physics and modeling: Proceedings

    SciTech Connect

    Parsa, Z.

    1991-01-01

    This report contains papers on the following topics: Physics of high brightness beams; radio frequency beam conditioner for fast-wave free-electron generators of coherent radiation; wake-field and space-charge effects on high brightness beams. Calculations and measured results for BNL-ATF; non-linear orbit theory and accelerator design; general problems of modeling for accelerators; development and application of dispersive soft ferrite models for time-domain simulation; and bunch lengthening in the SLC damping rings.

  5. Accelerator science in medical physics.

    PubMed

    Peach, K; Wilson, P; Jones, B

    2011-12-01

    The use of cyclotrons and synchrotrons to accelerate charged particles in hospital settings for the purpose of cancer therapy is increasing. Consequently, there is a growing demand from medical physicists, radiographers, physicians and oncologists for articles that explain the basic physical concepts of these technologies. There are unique advantages and disadvantages to all methods of acceleration. Several promising alternative methods of accelerating particles also have to be considered since they will become increasingly available with time; however, there are still many technical problems with these that require solving. This article serves as an introduction to this complex area of physics, and will be of benefit to those engaged in cancer therapy, or who intend to acquire such technologies in the future. PMID:22374548

  6. Accelerator science in medical physics

    PubMed Central

    Peach, K; Wilson, P; Jones, B

    2011-01-01

    The use of cyclotrons and synchrotrons to accelerate charged particles in hospital settings for the purpose of cancer therapy is increasing. Consequently, there is a growing demand from medical physicists, radiographers, physicians and oncologists for articles that explain the basic physical concepts of these technologies. There are unique advantages and disadvantages to all methods of acceleration. Several promising alternative methods of accelerating particles also have to be considered since they will become increasingly available with time; however, there are still many technical problems with these that require solving. This article serves as an introduction to this complex area of physics, and will be of benefit to those engaged in cancer therapy, or who intend to acquire such technologies in the future. PMID:22374548

  7. Compensation Techniques in Accelerator Physics

    SciTech Connect

    Sayed, Hisham Kamal

    2011-05-01

    Accelerator physics is one of the most diverse multidisciplinary fields of physics, wherein the dynamics of particle beams is studied. It takes more than the understanding of basic electromagnetic interactions to be able to predict the beam dynamics, and to be able to develop new techniques to produce, maintain, and deliver high quality beams for different applications. In this work, some basic theory regarding particle beam dynamics in accelerators will be presented. This basic theory, along with applying state of the art techniques in beam dynamics will be used in this dissertation to study and solve accelerator physics problems. Two problems involving compensation are studied in the context of the MEIC (Medium Energy Electron Ion Collider) project at Jefferson Laboratory. Several chromaticity (the energy dependence of the particle tune) compensation methods are evaluated numerically and deployed in a figure eight ring designed for the electrons in the collider. Furthermore, transverse coupling optics have been developed to compensate the coupling introduced by the spin rotators in the MEIC electron ring design.

  8. VLHC accelerator physics

    SciTech Connect

    Michael Blaskiewicz et al.

    2001-11-01

    A six-month design study for a future high energy hadron collider was initiated by the Fermilab director in October 2000. The request was to study a staged approach where a large circumference tunnel is built that initially would house a low field ({approx}2 T) collider with center-of-mass energy greater than 30 TeV and a peak (initial) luminosity of 10{sup 34} cm{sup -2}s{sup -1}. The tunnel was to be scoped, however, to support a future upgrade to a center-of-mass energy greater than 150 TeV with a peak luminosity of 2 x 10{sup 34} cm{sup -2} sec{sup -1} using high field ({approx} 10 T) superconducting magnet technology. In a collaboration with Brookhaven National Laboratory and Lawrence Berkeley National Laboratory, a report of the Design Study was produced by Fermilab in June 2001. 1 The Design Study focused on a Stage 1, 20 x 20 TeV collider using a 2-in-1 transmission line magnet and leads to a Stage 2, 87.5 x 87.5 TeV collider using 10 T Nb{sub 3}Sn magnet technology. The article that follows is a compilation of accelerator physics designs and computational results which contributed to the Design Study. Many of the parameters found in this report evolved during the study, and thus slight differences between this text and the Design Study report can be found. The present text, however, presents the major accelerator physics issues of the Very Large Hadron Collider as examined by the Design Study collaboration and provides a basis for discussion and further studies of VLHC accelerator parameters and design philosophies.

  9. Accelerated erosion: Process, problems, and prognosis

    NASA Astrophysics Data System (ADS)

    Toy, Terrence J.

    1982-10-01

    Soil erosion may well be the world's most serious environmental problem. A variety of human activities accelerates the rate of this geomorphie process by altering the natural characteristics of a site. The problems arising from accelerated erosion and subsequent deposition provide numerous research opportunities to both physical and social scientists whose cooperation will be necessary in our search for solutions. Factors of demography, economics, geography, and historical inertia to change suggest that man-induced erosion is likely to continue into the future unless this trend is abated by timely and forceful action.

  10. SPEAR3 Accelerator Physics Update

    SciTech Connect

    Safranek, James A.; Corbett, W.Jeff; Gierman, S.; Hettel, R.O.; Huang, X.; Nosochkov, Yuri; Sebek, Jim; Terebilo, Andrei; /SLAC

    2007-11-02

    The SPEAR3 storage ring at Stanford Synchrotron Radiation Laboratory has been delivering photon beams for three years. We will give an overview of recent and ongoing accelerator physics activities, including 500 mA fills, work toward top-off injection, long-term orbit stability characterization and improvement, fast orbit feedback, new chicane optics, low alpha optics & short bunches, low emittance optics, and MATLAB software. The accelerator physics group has a strong program to characterize and improve SPEAR3 performance

  11. The plasma physics of shock acceleration

    NASA Technical Reports Server (NTRS)

    Jones, Frank C.; Ellison, Donald C.

    1991-01-01

    The history and theory of shock acceleration is reviewed, paying particular attention to theories of parallel shocks which include the backreaction of accelerated particles on the shock structure. The work that computer simulations, both plasma and Monte Carlo, are playing in revealing how thermal ions interact with shocks and how particle acceleration appears to be an inevitable and necessary part of the basic plasma physics that governs collisionless shocks is discussed. Some of the outstanding problems that still confront theorists and observers in this field are described.

  12. Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams

    SciTech Connect

    Siemann, R.H.; /SLAC

    2011-10-24

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  13. Accelerator Physics Code Web Repository

    SciTech Connect

    Zimmermann, F.; Basset, R.; Bellodi, G.; Benedetto, E.; Dorda, U.; Giovannozzi, M.; Papaphilippou, Y.; Pieloni, T.; Ruggiero, F.; Rumolo, G.; Schmidt, F.; Todesco, E.; Zotter, B.W.; Payet, J.; Bartolini, R.; Farvacque, L.; Sen, T.; Chin, Y.H.; Ohmi, K.; Oide, K.; Furman, M.; /LBL, Berkeley /Oak Ridge /Pohang Accelerator Lab. /SLAC /TRIUMF /Tech-X, Boulder /UC, San Diego /Darmstadt, GSI /Rutherford /Brookhaven

    2006-10-24

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  14. ACCELERATION PHYSICS CODE WEB REPOSITORY.

    SciTech Connect

    WEI, J.

    2006-06-26

    In the framework of the CARE HHH European Network, we have developed a web-based dynamic accelerator-physics code repository. We describe the design, structure and contents of this repository, illustrate its usage, and discuss our future plans, with emphasis on code benchmarking.

  15. Analytical tools in accelerator physics

    SciTech Connect

    Litvinenko, V.N.

    2010-09-01

    This paper is a sub-set of my lectures presented in the Accelerator Physics course (USPAS, Santa Rosa, California, January 14-25, 2008). It is based on my notes I wrote during period from 1976 to 1979 in Novosibirsk. Only few copies (in Russian) were distributed to my colleagues in Novosibirsk Institute of Nuclear Physics. The goal of these notes is a complete description starting from the arbitrary reference orbit, explicit expressions for 4-potential and accelerator Hamiltonian and finishing with parameterization with action and angle variables. To a large degree follow logic developed in Theory of Cyclic Particle Accelerators by A.A.Kolmensky and A.N.Lebedev [Kolomensky], but going beyond the book in a number of directions. One of unusual feature is these notes use of matrix function and Sylvester formula for calculating matrices of arbitrary elements. Teaching the USPAS course motivated me to translate significant part of my notes into the English. I also included some introductory materials following Classical Theory of Fields by L.D. Landau and E.M. Liftsitz [Landau]. A large number of short notes covering various techniques are placed in the Appendices.

  16. Physics Problem Workbook, Student Manual.

    ERIC Educational Resources Information Center

    Jones, John L.

    This workbook contains 50 undergraduate physics problems designed for use in conjunction with a computer in a time-sharing mode. Each of the problems includes a statement of the problem topic, a background description of the problem, problem objectives, suggested readings, and a related graph or figure. Various topics in general physics are…

  17. Accelerator Physics Working Group Summary

    NASA Astrophysics Data System (ADS)

    Li, D.; Uesugi, T.; Wildnerc, E.

    2010-03-01

    The Accelerator Physics Working Group addressed the worldwide R&D activities performed in support of future neutrino facilities. These studies cover R&D activities for Super Beam, Beta Beam and muon-based Neutrino Factory facilities. Beta Beam activities reported the important progress made, together with the research activity planned for the coming years. Discussion sessions were also organized jointly with other working groups in order to define common ground for the optimization of a future neutrino facility. Lessons learned from already operating neutrino facilities provide key information for the design of any future neutrino facility, and were also discussed in this meeting. Radiation damage, remote handling for equipment maintenance and exchange, and primary proton beam stability and monitoring were among the important subjects presented and discussed. Status reports for each of the facility subsystems were presented: proton drivers, targets, capture systems, and muon cooling and acceleration systems. The preferred scenario for each type of possible future facility was presented, together with the challenges and remaining issues. The baseline specification for the muon-based Neutrino Factory was reviewed and updated where required. This report will emphasize new results and ideas and discuss possible changes in the baseline scenarios of the facilities. A list of possible future steps is proposed that should be followed up at NuFact10.

  18. The Influence of Accelerator Science on Physics Research

    NASA Astrophysics Data System (ADS)

    Haussecker, Enzo F.; Chao, Alexander W.

    2011-06-01

    We evaluate accelerator science in the context of its contributions to the physics community. We address the problem of quantifying these contributions and present a scheme for a numerical evaluation of them. We show by using a statistical sample of important developments in modern physics that accelerator science has influenced 28% of post-1938 physicists and also 28% of post-1938 physics research. We also examine how the influence of accelerator science has evolved over time, and show that on average it has contributed to a physics Nobel Prize-winning research every 2.9 years.

  19. New ways of investigating the canonical coin toss acceleration problem

    NASA Astrophysics Data System (ADS)

    Wittmann, Michael C.; Hawkins, Jeffrey M.

    2013-01-01

    Asking students about the acceleration of a tossed object is a well-studied problem in physics education research. Students frequently respond using reasoning that describes the velocity of the object, in particular that acceleration is zero at the top. We created new versions of the canonical multiple-choice Force and Motion Conceptual Evaluation coin-toss questions to investigate what other reasoning students might use. Some students were asked "is the acceleration zero at the top?" Other students were told "the acceleration is not zero" and asked to explain. A third group answered the original multiple-choice version of the question. Our results suggest that some students give answers that they can explain are incorrect. We also find that some students' responses about the acceleration at the turnaround point are affected by question format.

  20. Accelerator physics R and D

    NASA Astrophysics Data System (ADS)

    Krisch, A. D.

    1994-08-01

    This report discusses the NEPTUN-A experiment that will study spin effects in violent proton-proton collisions; the Siberian snake tests at IUCF cooler ring; polarized gas jets; and polarized proton acceleration to 1 TeV at Fermilab.

  1. Control problems in very large accelerators

    SciTech Connect

    Crowley-Milling, M.C.

    1985-04-01

    There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have the same types of control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. It is the purpose of this paper to look at the special control problems of large accelerators, which the author shall arbitrarily define as those with a length or circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system.

  2. Accelerator physics experiments at Aladdin

    SciTech Connect

    Chattopadhyay, S.; Cornacchia, M.; Jackson, A.; Zisman, M.S.

    1985-07-01

    The Aladdin accelerator is a 1 GeV synchrotron light source located at the University of Wisconsin. The results of experimental studies of the Aladdin accelerator are described. The primary purpose of the experiments reported was to investigate reported anomalies in the behavior of the linear lattice, particularly in the vertical plane. A second goal was to estimate the ring broadband impedance. Experimental observations and interpretation of the linear properties of the Aladdin ring are described, including the beta function and dispersion measurements. Two experiments are described to measure the ring impedance, the first a measurement of the parasitic mode loss, and the second a measurement of the beam transfer function. Measurements of the longitudinal and transverse emittance at 100 and 200 MeV are described and compared with predictions. 10 refs., 24 figs., 2 tabs. (LEW)

  3. Physics and Accelerator Applications of RF Superconductivity

    SciTech Connect

    H. Padamsee; K. W. Shepard; Ron Sundelin

    1993-12-01

    A key component of any particle accelerator is the device that imparts energy gain to the charged particle. This is usually an electromagnetic cavity resonating at a microwave frequency, chosen between 100 and 3000 MHz. Serious attempts to utilize superconductors for accelerating cavities were initiated more than 25 years ago with the acceleration of electrons in a lead-plated resonator at Stanford University (1). The first full-scale accelerator, the Stanford SCA, was completed in 1978 at the High Energy Physics Laboratory (HEPL) (2). Over the intervening one and a half decades, superconducting cavities have become increasingly important to particle accelerators for nuclear physics and high energy physics. For continuous operation, as is required for many applications, the power dissipation in the walls of a copper structure is quite substantial, for example, 0.1 megawatts per meter of structure operating at an accelerating field of 1 million volts/meter (MV/m). since losses increase as the square of the accelerating field, copper cavities become severely uneconomical as demand for higher fields grows with the higher energies called for by experimenters to probe ever deeper into the structure of matter. Rf superconductivity has become an important technology for particle accelerators. Practical structures with attractive performance levels have been developed for a variety of applications, installed in the targeted accelerators, and operated over significant lengths of time. Substantial progress has been made in understanding field and Q limitations and in inventing cures to advance performance. The technical and economical potential of rf superconductivity makes it an important candidate for future advanced accelerators for free electron lasers, for nuclear physics, and for high energy physics, at the luminosity as well as at the energy frontiers.

  4. New accelerators in high-energy physics

    SciTech Connect

    Blewett, J.P.

    1982-01-01

    First, I should like to mention a few new ideas that have appeared during the last few years in the accelerator field. A couple are of importance in the design of injectors, usually linear accelerators, for high-energy machines. Then I shall review some of the somewhat sensational accelerator projects, now in operation, under construction or just being proposed. Finally, I propose to mention a few applications of high-energy accelerators in fields other than high-energy physics. I realize that this is a digression from my title but I hope that you will find it interesting.

  5. CAS CERN Accelerator School 5th General Accelerator Physics Course

    NASA Astrophysics Data System (ADS)

    Turner, S.

    1994-01-01

    The fifth CERN Accelerator School (CAS) basic course on General Accelerator Physics was given at the University of Jyvaeskylae, Finland, from 7 to 18 September 1992. Its syllabus was based on the previous similar courses held at Gif-sur-Yvette in 1984, Aarhus 1986, Salamanca 1988 and Juelich 1990, and whose proceedings were published as CERN Reports 85-19, 87-10, 89-05 and 91-04, respectively. However, certain topics were treated in a different way, improved or extended, while new subjects were introduced. As far as the proceedings of this school are concerned the opportunity was taken not only to include the lectures presented but also to select and revise the most appropriate chapters from the previous similar schools. In this way the present volumes constitute a rather complete introduction to all aspects of the design and construction of particle accelerators, including optics, emittance, luminosity, longitudinal and transverse beam dynamics, insertions, chromaticity, transfer lines, resonances, accelerating structures, tune shifts, coasting beams, lifetime, synchrotron radiation, radiation damping, beam-beam effects, diagnostics, cooling, ion and positron sources, RF and vacuum systems, injection and extraction, conventional, permanent and superconducting magnets, cyclotrons, RF linear accelerators, microtrons, as well as applications of particle accelerators (including therapy) and the history of accelerators. See hints under the relevant topics.

  6. Computational Accelerator Physics Working Group Summary

    SciTech Connect

    Cary, John R.; Bohn, Courtlandt L.

    2004-08-27

    The working group on computational accelerator physics at the 11th Advanced Accelerator Concepts Workshop held a series of meetings during the Workshop. Verification, i.e., showing that a computational application correctly solves the assumed model, and validation, i.e., showing that the model correctly describes the modeled system, were discussed for a number of systems. In particular, the predictions of the massively parallel codes, OSIRIS and VORPAL, used for modeling advanced accelerator concepts, were compared and shown to agree, thereby establishing some verification of both codes. In addition, a number of talks on the status and frontiers of computational accelerator physics were presented, to include the modeling of ultrahigh-brightness electron photoinjectors and the physics of beam halo production. Finally, talks discussing computational needs were presented.

  7. Computational Accelerator Physics Working Group Summary

    SciTech Connect

    Cary, John R.; Bohn, Courtlandt L.

    2004-12-07

    The working group on computational accelerator physics at the 11th Advanced Accelerator Concepts Workshop held a series of meetings during the Workshop. Verification, i.e., showing that a computational application correctly solves the assumed model, and validation, i.e., showing that the model correctly describes the modeled system, were discussed for a number of systems. In particular, the predictions of the massively parallel codes, OSIRIS and VORPAL, used for modeling advanced accelerator concepts, were compared and shown to agree, thereby establishing some verification of both codes. In addition, a number of talks on the status and frontiers of computational accelerator physics were presented, to include the modeling of ultrahigh-brightness electron photoinjectors and the physics of beam halo production. Finally, talks discussing computational needs were presented.

  8. Control problems in very large accelerators

    SciTech Connect

    Crowley-Milling, M.C.

    1985-06-01

    There is no fundamental difference of kind in the control requirements between a small and a large accelerator since they are built of the same types of components, which individually have similar control inputs and outputs. The main difference is one of scale; the large machine has many more components of each type, and the distances involved are much greater. Both of these factors must be taken into account in determining the optimum way of carrying out the control functions. Small machines should use standard equipment and software for control as much as possible, as special developments for small quantities cannot normally be justified if all costs are taken into account. On the other hand, the very great number of devices needed for a large machine means that, if special developments can result in simplification, they may make possible an appreciable reduction in the control equipment costs. It is the purpose of this report to look at the special control problems of large accelerators, which the author shall arbitarily define as those with a length of circumference in excess of 10 km, and point out where special developments, or the adoption of developments from outside the accelerator control field, can be of assistance in minimizing the cost of the control system. Most of the first part of this report was presented as a paper to the 1985 Particle Accelerator Conference. It has now been extended to include a discussion on the special case of the controls for the SSC.

  9. Non-accelerator particle physics

    SciTech Connect

    Steinberg, R.I.; Lane, C.E.

    1991-09-01

    The goals of this research are the experimental testing of fundamental theories of physics such as grand unification and the exploration of cosmic phenomena through the techniques of particle physics. We are working on the MACRO experiment, which employs a large area underground detector to search for grand unification magnetic monopoles and dark matter candidates and to study cosmic ray muons as well as low and high energy neutrinos: the {nu}IMB project, which seeks to refurbish and upgrade the IMB water Cerenkov detector to perform an improved proton decay search together with a long baseline reactor neutrino oscillation experiment using a kiloton liquid scintillator (the Perry experiment); and development of technology for improved liquid scintillators and for very low background materials in support of the MACRO and Perry experiments and for new solar neutrino experiments. 21 refs., 19 figs., 6 tabs.

  10. Laser Wakefield Acceleration and Fundamental Physics

    SciTech Connect

    Tajima, Toshiki

    2011-06-20

    The laser wakefield acceleration (LWFA) along with the now available laser technology allows us to look at TeV physics both in leptons and hadrons. Near future proof-of-principle experiments for a collider as well as high energy frontier experiments without a collider paradigm are suggested. The intense laser can also contribute to other fundamental physics explorations such as those of dark matter and dark energy candidates. Finally the combination of intense laser and laser-accelerated particles (electrons, hadrons, gammas) provides a further avenue of fundamental research.

  11. An introduction to the physics of high energy accelerators

    SciTech Connect

    Edwards, D.A.; Syphers, J.J.

    1993-01-01

    This book is an outgrowth of a course given by the authors at various universities and particle accelerator schools. It starts from the basic physics principles governing particle motion inside an accelerator, and leads to a full description of the complicated phenomena and analytical tools encountered in the design and operation of a working accelerator. The book covers acceleration and longitudinal beam dynamics, transverse motion and nonlinear perturbations, intensity dependent effects, emittance preservation methods and synchrotron radiation. These subjects encompass the core concerns of a high energy synchrotron. The authors apparently do not assume the reader has much previous knowledge about accelerator physics. Hence, they take great care to introduce the physical phenomena encountered and the concepts used to describe them. The mathematical formulae and derivations are deliberately kept at a level suitable for beginners. After mastering this course, any interested reader will not find it difficult to follow subjects of more current interests. Useful homework problems are provided at the end of each chapter. Many of the problems are based on actual activities associated with the design and operation of existing accelerators.

  12. Wavelet approach to accelerator problems. 1: Polynomial dynamics

    SciTech Connect

    Fedorova, A.; Zeitlin, M.; Parsa, Z.

    1997-05-01

    This is the first part of a series of talks in which the authors present applications of methods from wavelet analysis to polynomial approximations for a number of accelerator physics problems. In the general case they have the solution as a multiresolution expansion in the base of compactly supported wavelet basis. The solution is parameterized by solutions of two reduced algebraical problems, one is nonlinear and the second is some linear problem, which is obtained from one of the next wavelet constructions: Fast Wavelet Transform, Stationary Subdivision Schemes, the method of Connection Coefficients. In this paper the authors consider the problem of calculation of orbital motion in storage rings. The key point in the solution of this problem is the use of the methods of wavelet analysis, relatively novel set of mathematical methods, which gives one a possibility to work with well-localized bases in functional spaces and with the general type of operators (including pseudodifferential) in such bases.

  13. Basic Health Physics: Problems and Solutions

    NASA Astrophysics Data System (ADS)

    Bevelacqua, Joseph John

    1999-01-01

    Radiation litigation, the cleanup and decommissioning of nuclear facilities, radon exposure, nuclear medicine, food irradiation, stricter regulatory climate--these are some of the reasons health physics and radiation protection professionals are increasingly called upon to upgrade their skills. Designed to prepare candidates for the American Board of Health Physics Comprehensive examination (Part I) and other certification examinations, Basic Health Physics: Problems and Solutions introduces professionals in the field to radiation protection principles and their practical application in routine and emergency situations. It features more than 650 worked examples illustrating concepts under discussion along with an in-depth coverage of sources of radiation, standards and regulations, biological effects of ionizing radiation, instrumentation, external and internal dosimetry, counting statistics, monitoring and interpretations, operational health physics, transportation and waste, nuclear emergencies, and more. Reflecting for the first time the true scope of health physics at an introductory level, Basic Health Physics: Problems and Solutions gives readers the tools to properly evaluate challenging situations in all areas of radiation protection, including the medical, university, power reactor, fuel cycle, research reactor, environmental, non-ionizing radiation, and accelerator health physics.

  14. TOPICS IN THE PHYSICS OF PARTICLE ACCELERATORS

    SciTech Connect

    Sessler, A.M.

    1984-07-01

    High energy physics, perhaps more than any other branch of science, is driven by technology. It is not the development of theory, or consideration of what measurements to make, which are the driving elements in our science. Rather it is the development of new technology which is the pacing item. Thus it is the development of new techniques, new computers, and new materials which allows one to develop new detectors and new particle-handling devices. It is the latter, the accelerators, which are at the heart of the science. Without particle accelerators there would be, essentially, no high energy physics. In fact. the advances in high energy physics can be directly tied to the advances in particle accelerators. Looking terribly briefly, and restricting one's self to recent history, the Bevatron made possible the discovery of the anti-proton and many of the resonances, on the AGS was found the {mu}-neutrino, the J-particle and time reversal non-invariance, on Spear was found the {psi}-particle, and, within the last year the Z{sub 0} and W{sup {+-}} were seen on the CERN SPS p-{bar p} collider. Of course one could, and should, go on in much more detail with this survey, but I think there is no need. It is clear that as better acceleration techniques were developed more and more powerful machines were built which, as a result, allowed high energy physics to advance. What are these techniques? They are very sophisticated and ever-developing. The science is very extensive and many individuals devote their whole lives to accelerator physics. As high energy experimental physicists your professional lives will be dominated by the performance of 'the machine'; i.e. the accelerator. Primarily you will be frustrated by the fact that it doesn't perform better. Why not? In these lectures, six in all, you should receive some appreciation of accelerator physics. We cannot, nor do we attempt, to make you into accelerator physicists, but we do hope to give you some insight into the

  15. Applications of the ARGUS code in accelerator physics

    SciTech Connect

    Petillo, J.J.; Mankofsky, A.; Krueger, W.A.; Kostas, C.; Mondelli, A.A.; Drobot, A.T.

    1993-12-31

    ARGUS is a three-dimensional, electromagnetic, particle-in-cell (PIC) simulation code that is being distributed to U.S. accelerator laboratories in collaboration between SAIC and the Los Alamos Accelerator Code Group. It uses a modular architecture that allows multiple physics modules to share common utilities for grid and structure input., memory management, disk I/O, and diagnostics, Physics modules are in place for electrostatic and electromagnetic field solutions., frequency-domain (eigenvalue) solutions, time- dependent PIC, and steady-state PIC simulations. All of the modules are implemented with a domain-decomposition architecture that allows large problems to be broken up into pieces that fit in core and that facilitates the adaptation of ARGUS for parallel processing ARGUS operates on either Cray or workstation platforms, and MOTIF-based user interface is available for X-windows terminals. Applications of ARGUS in accelerator physics and design are described in this paper.

  16. Quantum simulations of physics problems

    NASA Astrophysics Data System (ADS)

    Somma, Rolando D.; Ortiz, Gerardo; Knill, Emanuel H.; Gubernatis, James

    2003-08-01

    If a large Quantum Computer (QC) existed today, what type of physical problems could we efficiently simulate on it that we could not simulate on a classical Turing machine? In this paper we argue that a QC could solve some relevant physical "questions" more efficiently. The existence of one-to-one mappings between different algebras of observables or between different Hilbert spaces allow us to represent and imitate any physical system by any other one (e.g., a bosonic system by a spin-1/2 system). We explain how these mappings can be performed showing quantum networks useful for the efficient evaluation of some physical properties, such as correlation functions and energy spectra.

  17. Scale problem in wormhole physics

    SciTech Connect

    Kim, J. E.; Lee, K.

    1989-07-03

    Wormhole physics from the quantum thoery of gravity coupled to the second-rank antisymmetric tensor or Goldstone-boson fields leads to an effective potential for these fields. The cosmological energy-density bound is shown to put an upper bound on the cosmological constant which wormhole physics can make zero. This upper bound, of order 10/sup 11/ GeV, is far smaller than the Planck scale and barely compatible with the possible cosmological constant arising from grand unified theories. In addition, the effect of wormholes on the axion for the strong /ital CP/ problem is discussed.

  18. Accelerator Physics: An Undergraduate Course in Experimental Nuclear Physics

    ERIC Educational Resources Information Center

    Fielder, Douglas S.

    1976-01-01

    Discusses a 2-semester-hour experimental physics course utilizing a 0.5 MeV Van de Graaff accelerator. The course requires the completion of six or seven laboratory projects including complete written reports, and theory is emphasized only to the extent needed to understand the projects. (MLH)

  19. Wavelet approach to accelerator problems. 2: Metaplectic wavelets

    SciTech Connect

    Fedorova, A.; Zeitlin, M.; Parsa, Z.

    1997-05-01

    This is the second part of a series of talks in which the authors present applications of wavelet analysis to polynomial approximations for a number of accelerator physics problems. According to the orbit method and by using construction from the geometric quantization theory they construct the symplectic and Poisson structures associated with generalized wavelets by using metaplectic structure and corresponding polarization. The key point is a consideration of semidirect product of Heisenberg group and metaplectic group as subgroup of automorphisms group of dual to symplectic space, which consists of elements acting by affine transformations.

  20. Essay: Accelerators, Beams and Physical Review Special Topics - Accelerators and Beams

    NASA Astrophysics Data System (ADS)

    Siemann, Robert H.

    2008-05-01

    Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

  1. Better physical activity classification using smartphone acceleration sensor.

    PubMed

    Arif, Muhammad; Bilal, Mohsin; Kattan, Ahmed; Ahamed, S Iqbal

    2014-09-01

    Obesity is becoming one of the serious problems for the health of worldwide population. Social interactions on mobile phones and computers via internet through social e-networks are one of the major causes of lack of physical activities. For the health specialist, it is important to track the record of physical activities of the obese or overweight patients to supervise weight loss control. In this study, acceleration sensor present in the smartphone is used to monitor the physical activity of the user. Physical activities including Walking, Jogging, Sitting, Standing, Walking upstairs and Walking downstairs are classified. Time domain features are extracted from the acceleration data recorded by smartphone during different physical activities. Time and space complexity of the whole framework is done by optimal feature subset selection and pruning of instances. Classification results of six physical activities are reported in this paper. Using simple time domain features, 99 % classification accuracy is achieved. Furthermore, attributes subset selection is used to remove the redundant features and to minimize the time complexity of the algorithm. A subset of 30 features produced more than 98 % classification accuracy for the six physical activities. PMID:25000988

  2. Toilet Training Problems Could Be Physical

    MedlinePlus

    ... Español Text Size Email Print Share Toilet Training Problems Could Be Physical Page Content Article Body Many ... to young children’s toilet use result from physical problems that can be easily identified and resolved by ...

  3. A Multivariate Model of Physics Problem Solving

    ERIC Educational Resources Information Center

    Taasoobshirazi, Gita; Farley, John

    2013-01-01

    A model of expertise in physics problem solving was tested on undergraduate science, physics, and engineering majors enrolled in an introductory-level physics course. Structural equation modeling was used to test hypothesized relationships among variables linked to expertise in physics problem solving including motivation, metacognitive planning,…

  4. Solving radiation problems at particle accelerators

    SciTech Connect

    Nikolai V. Mokhov

    2001-12-11

    At high-intensity high-energy particle accelerators, consequences of a beam-induced radiation impact on machine and detector components, people, environment and complex performance can range from negligible to severe. The specifics, general approach and tools used at such machines for radiation analysis are described. In particular, the world leader Fermilab accelerator complex is considered, with its fixed target and collider experiments, as well as new challenging projects such as LHC, VLHC, muon collider and neutrino factory. The emphasis is on mitigation of deleterious beam-induced radiation effects and on the key role of effective computer simulations.

  5. Pulsed power accelerator for material physics experiments

    NASA Astrophysics Data System (ADS)

    Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Austin, K. N.; Waisman, E. M.; Hickman, R. J.; Davis, J.-P.; Haill, T. A.; Knudson, M. D.; Seagle, C. T.; Brown, J. L.; Goerz, D. A.; Spielman, R. B.; Goldlust, J. A.; Cravey, W. R.

    2015-09-01

    We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments.

  6. Theoretical problems in accelerator physics. Progress report

    SciTech Connect

    Not Available

    1994-08-01

    This is the second progress report submitted under the author`s current grant and covers progress made since the submission of the first progress report in August 1993. During this period the author has continued to spend approximately one half of his time at SLAC and most of the projects reported here were carried out in collaboration with individuals and groups at SLAC. Except where otherwise noted, reference numbers in the text refer to the attached list of current contract publications. Copies of the publications, numbered in agreement with the publication list, are included with this report.

  7. Tevatron accelerator physics and operation highlights

    SciTech Connect

    Valishev, A.; /Fermilab

    2011-03-01

    The performance of the Tevatron collider demonstrated continuous growth over the course of Run II, with the peak luminosity reaching 4 x 10{sup 32} cm{sup -2} s{sup -1}, and the weekly integration rate exceeding 70 pb{sup -1}. This report presents a review of the most important advances that contributed to this performance improvement, including beam dynamics modeling, precision optics measurements and stability control, implementation of collimation during low-beta squeeze. Algorithms employed for optimization of the luminosity integration are presented and the lessons learned from high-luminosity operation are discussed. Studies of novel accelerator physics concepts at the Tevatron are described, such as the collimation techniques using crystal collimator and hollow electron beam, and compensation of beam-beam effects.

  8. Accelerator physics: Surf's up at SLAC

    NASA Astrophysics Data System (ADS)

    Downer, Mike; Zgadzaj, Rafal

    2014-11-01

    A 'plasma afterburner' just 30 centimetres long accelerates electrons hundreds of times faster than giant conventional accelerators. The result may ultimately open up a low-cost technology for particle colliders. See Letter p.92

  9. New Approach to Analyzing Physics Problems: A Taxonomy of Introductory Physics Problems

    ERIC Educational Resources Information Center

    Teodorescu, Raluca E.; Bennhold, Cornelius; Feldman, Gerald; Medsker, Larry

    2013-01-01

    This paper describes research on a classification of physics problems in the context of introductory physics courses. This classification, called the Taxonomy of Introductory Physics Problems (TIPP), relates physics problems to the cognitive processes required to solve them. TIPP was created in order to design educational objectives, to develop…

  10. Fluid Physics in a Fluctuating Acceleration Environment

    NASA Technical Reports Server (NTRS)

    Drolet, Francois; Vinals, Jorge

    1999-01-01

    , and on cavity flow as an example of how an oscillatory response under periodic driving becomes diffusive if the forcing is random instead. This paper describes three different topics that illustrate behavior that is peculiar to a stochastic acceleration field. In the first case, we show that g-jitter can induce effective attractive or repulsive forces between a pair of spherical particles that are suspended in an incompressible fluid of different density provided that the momentum diffusion length is larger than the interparticle separation (as in the case in most colloidal suspensions). Second, a stochastic modulation of the control parameter in the vicinity of a pitchfork or supercritical bifurcation is known not to affect the location of the threshold. We show, however, that resonance between the modulation and linearly stable modes close to onset can lead to a shift in threshold. Finally, we discuss the classical problem of vorticity diffusion away from a plane boundary that is being vibrated along its own plane. Periodic motion with zero average vorticity production results in an exponential decay of the vorticity away from the boundary. Random vibration, on the other hand, results in power law decay away from the boundary even if vorticity production averages to zero.

  11. Datum definition problems in accelerator alignment

    SciTech Connect

    Bell, B.; Friedsam, H.; Oren, W.; Ruland, R.

    1990-04-01

    Any measurement task requires a fixed reference base (the datum) from which measurements can be made and calculated. The linac was the datum to which all SLC components were aligned; although this reference existed as a physical object, the actual establishment of the datum and its transferral to datums that were more useful for the SLC installation challenged the technology and computational ability of the survey group. Once established, the maintenance of datums is not to be taken for granted, as demonstrated by the 1989 earthquake which destroyed all SLAC's survey datums. 7 refs., 6 figs.

  12. Physics Problem Workbook, Instructor Manual.

    ERIC Educational Resources Information Center

    Jones, John L.

    This publication of Computer Oriented Materials Production for Undergraduate Teaching (COMPUTe), is intended to aid in the development of an autotutorial program for college-level undergraduate physics. Particularly in the area of mechanics, the author feels there is a need for a tutorial program which enables students to use a variety of…

  13. Model Formulation for Physics Problem Solving. Draft.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.

    The major task in solving a physics problem is to construct an appropriate model of the problem in terms of physical principles. The functions performed by such a model, the information which needs to be represented, and the knowledge used in selecting and instantiating an appropriate model are discussed. An example of a model for a mechanics…

  14. Guide to accelerator physics program SYNCH: VAX version 1987. 2

    SciTech Connect

    Parsa, Z.; Courant, E.

    1987-01-01

    This guide is written to accommodate users of Accelerator Physics Data Base BNLDAG::DUAO:(PARSA1). It describes the contents of the on line Accelerator Physics data base DUAO:(PARSA1.SYNCH). SYNCH is a computer program used for the design and analysis of synchrotrons, storage rings and beamlines.

  15. Advanced Computing Tools and Models for Accelerator Physics

    SciTech Connect

    Ryne, Robert; Ryne, Robert D.

    2008-06-11

    This paper is based on a transcript of my EPAC'08 presentation on advanced computing tools for accelerator physics. Following an introduction I present several examples, provide a history of the development of beam dynamics capabilities, and conclude with thoughts on the future of large scale computing in accelerator physics.

  16. Physical activities to enhance an understanding of acceleration

    NASA Astrophysics Data System (ADS)

    Lee, S. A.

    2006-03-01

    On the basis of their everyday experiences, students have developed an understanding of many of the concepts of mechanics by the time they take their first physics course. However, an accurate understanding of acceleration remains elusive. Many students have difficulties distinguishing between velocity and acceleration. In this report, a set of physical activities to highlight the differences between acceleration and velocity are described. These activities involve running and walking on sand (such as an outdoor volleyball court).

  17. STOCHASTIC PARTICLE ACCELERATION AND THE PROBLEM OF BACKGROUND PLASMA OVERHEATING

    SciTech Connect

    Chernyshov, D. O.; Dogiel, V. A.; Ko, C. M.

    2012-11-10

    The origin of hard X-ray (HXR) excess emission from clusters of galaxies is still an enigma, whose nature is debated. One of the possible mechanisms to produce this emission is the bremsstrahlung model. However, previous analytical and numerical calculations showed that in this case the intracluster plasma had to be overheated very fast because suprathermal electrons emitting the HXR excess lose their energy mainly by Coulomb losses, i.e., they heat the background plasma. It was concluded also from these investigations that it is problematic to produce emitting electrons from a background plasma by stochastic (Fermi) acceleration because the energy supplied by external sources in the form of Fermi acceleration is quickly absorbed by the background plasma. In other words, the Fermi acceleration is ineffective for particle acceleration. We revisited this problem and found that at some parameter of acceleration the rate of plasma heating is rather low and the acceleration tails of nonthermal particles can be generated and exist for a long time while the plasma temperature is almost constant. We showed also that for some regime of acceleration the plasma cools down instead of being heated up, even though external sources (in the form of external acceleration) supply energy to the system. The reason is that the acceleration withdraws effectively high-energy particles from the thermal pool (analog of Maxwell demon).

  18. Genetic algorithms and their applications in accelerator physics

    SciTech Connect

    Hofler, Alicia S.

    2013-12-01

    Multi-objective optimization techniques are widely used in an extremely broad range of fields. Genetic optimization for multi-objective optimization was introduced in the accelerator community in relatively recent times and quickly spread becoming a fundamental tool in multi-dimensional optimization problems. This discussion introduces the basics of the technique and reviews applications in accelerator problems.

  19. Fifty years of accelerator based physics at Chalk River

    SciTech Connect

    McKay, John W.

    1999-04-26

    The Chalk River Laboratories of Atomic Energy of Canada Ltd. was a major centre for Accelerator based physics for the last fifty years. As early as 1946, nuclear structure studies were started on Cockroft-Walton accelerators. A series of accelerators followed, including the world's first Tandem, and the MP Tandem, Superconducting Cyclotron (TASCC) facility that was opened in 1986. The nuclear physics program was shut down in 1996. This paper will describe some of the highlights of the accelerators and the research of the laboratory.

  20. Using artistic drawings to create physics problems

    NASA Astrophysics Data System (ADS)

    Planinšič, Gorazd

    2015-10-01

    Drawings, figures, and sketches are common companions of traditional physics problems. Usually, teachers use them as supplements to the text of the problem. If the text can be understood without a sketch or a drawing, many teachers would see no reason to add it. On the other hand, some teachers like to use drawings (or photos) even when this is not necessary, mostly to make handouts more attractive for the students. But drawings (cartoons, art, photos) can play a more active, or proactive (or even provocative), role in physics problems. Here we present some new suggestions of how to use drawings (cartoons, art, etc.) in physics problems. The nontraditional problems in this paper use the new types of problems introduced in a recently published textbook.

  1. High Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    SciTech Connect

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-07-28

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space, and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing are essential for accurately modeling them. In the past decade, the US Department of Energy's SciDAC program has produced accelerator-modeling tools that have been employed to tackle some of the most difficult accelerator science problems. The authors discuss the Synergia framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable of handling the entire spectrum of beam dynamics simulations. Our authors present Synergia's design principles and its performance on HPC platforms.

  2. High Performance Computing Modeling Advances Accelerator Science for High-Energy Physics

    DOE PAGESBeta

    Amundson, James; Macridin, Alexandru; Spentzouris, Panagiotis

    2014-07-28

    The development and optimization of particle accelerators are essential for advancing our understanding of the properties of matter, energy, space, and time. Particle accelerators are complex devices whose behavior involves many physical effects on multiple scales. Therefore, advanced computational tools utilizing high-performance computing are essential for accurately modeling them. In the past decade, the US Department of Energy's SciDAC program has produced accelerator-modeling tools that have been employed to tackle some of the most difficult accelerator science problems. The authors discuss the Synergia framework and its applications to high-intensity particle accelerator physics. Synergia is an accelerator simulation package capable ofmore » handling the entire spectrum of beam dynamics simulations. Our authors present Synergia's design principles and its performance on HPC platforms.« less

  3. Physics: Quantum problems solved through games

    NASA Astrophysics Data System (ADS)

    Maniscalco, Sabrina

    2016-04-01

    Humans are better than computers at performing certain tasks because of their intuition and superior visual processing. Video games are now being used to channel these abilities to solve problems in quantum physics. See Letter p.210

  4. Neutrino physics with accelerator driven subcritical reactors

    NASA Astrophysics Data System (ADS)

    Ciuffoli, Emilio; Evslin, Jarah; Zhao, Fengyi

    2016-01-01

    Accelerator driven system (ADS) subcritical nuclear reactors are under development around the world. They will be intense sources of free, 30-55 MeV μ + decay at rest {overline{ν}}_{μ } . These ADS reactor neutrinos can provide a robust test of the LSND anomaly and a precise measurement of the leptonic CP-violating phase δ, including sign(cos(δ)). The first phase of many ADS programs includes the construction of a low energy, high intensity proton or deuteron accelerator, which can yield competitive bounds on sterile neutrinos.

  5. Chaotic dynamics in accelerator physics. Progress report

    SciTech Connect

    Cary, J.R.

    1992-11-30

    Substantial progress was in several areas of accelerator dynamics. For developing understanding of longitudinal adiabatic dynamics, and for creating efficiency enhancements of recirculating free-electron lasers, was substantially completed. A computer code for analyzing the critical KAM tori that bound the dynamic aperture in circular machines was developed. Studies of modes that arise due to the interaction of coating beams with a narrow-spectrum impedance have begun. During this research educational and research ties with the accelerator community at large have been strengthened.

  6. Fluid Physics Under a Stochastic Acceleration Field

    NASA Technical Reports Server (NTRS)

    Vinals, Jorge

    2001-01-01

    The research summarized in this report has involved a combined theoretical and computational study of fluid flow that results from the random acceleration environment present onboard space orbiters, also known as g-jitter. We have focused on a statistical description of the observed g-jitter, on the flows that such an acceleration field can induce in a number of experimental configurations of interest, and on extending previously developed methodology to boundary layer flows. Narrow band noise has been shown to describe many of the features of acceleration data collected during space missions. The scale of baroclinically induced flows when the driving acceleration is random is not given by the Rayleigh number. Spatially uniform g-jitter induces additional hydrodynamic forces among suspended particles in incompressible fluids. Stochastic modulation of the control parameter shifts the location of the onset of an oscillatory instability. Random vibration of solid boundaries leads to separation of boundary layers. Steady streaming ahead of a modulated solid-melt interface enhances solute transport, and modifies the stability boundaries of a planar front.

  7. Fluid Physics in a Fluctuating Acceleration Environment

    NASA Technical Reports Server (NTRS)

    Thomson, J. Ross; Drolet, Francois; Vinals, Jorge

    1996-01-01

    We summarize several aspects of an ongoing investigation of the effects that stochastic residual accelerations (g-jitter) onboard spacecraft can have on experiments conducted in a microgravity environment. The residual acceleration field is modeled as a narrow band noise, characterized by three independent parameters: intensity (g(exp 2)), dominant angular frequency Omega, and characteristic correlation time tau. Realistic values for these parameters are obtained from an analysis of acceleration data corresponding to the SL-J mission, as recorded by the SAMS instruments. We then use the model to address the random motion of a solid particle suspended in an incompressible fluid subjected to such random accelerations. As an extension, the effect of jitter on coarsening of a solid-liquid mixture is briefly discussed, and corrections to diffusion controlled coarsening evaluated. We conclude that jitter will not be significant in the experiment 'Coarsening of solid-liquid mixtures' to be conducted in microgravity. Finally, modifications to the location of onset of instability in systems driven by a random force are discussed by extending the standard reduction to the center manifold to the stochastic case. Results pertaining to time-modulated oscillatory convection are briefly discussed.

  8. Models of Strategy for Solving Physics Problems.

    ERIC Educational Resources Information Center

    Larkin, Jill H.

    A set of computer implemented models are presented which can assist in developing problem solving strategies. The three levels of expertise which are covered are beginners (those who have completed at least one university physics course), intermediates (university level physics majors in their third year of study), and professionals (university…

  9. Recognizing Physical Disability as a Social Problem.

    ERIC Educational Resources Information Center

    Blake, Charles

    Physical disability is an enormous psychosocio-economic-medical problem that affects over 24 million Americans. Public policy endorses a multi-disciplinary approach in analyzing this issue. Legislation has broadened the meaning of physical disability to include persons with mental and emotional disorders. Some of the costs associated with physical…

  10. Conceptual Problem Solving in High School Physics

    ERIC Educational Resources Information Center

    Docktor, Jennifer L.; Strand, Natalie E.; Mestre, José P.; Ross, Brian H.

    2015-01-01

    Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an…

  11. Spatial Visualization in Physics Problem Solving

    ERIC Educational Resources Information Center

    Kozhevnikov, Maria; Motes, Michael A.; Hegarty, Mary

    2007-01-01

    Three studies were conducted to examine the relation of spatial visualization to solving kinematics problems that involved either predicting the two-dimensional motion of an object, translating from one frame of reference to another, or interpreting kinematics graphs. In Study 1, 60 physics-naive students were administered kinematics problems and…

  12. A Collection of Problems for Physics Teaching

    ERIC Educational Resources Information Center

    Grober, S.; Jodl, H. -J.

    2010-01-01

    Problems are an important instrument for teachers to mediate physics content and for learners to adopt this content. This collection of problems is not only suited to traditional teaching and learning in lectures or student labs, but also to all kinds of new ways of teaching and learning, such as self-study, long-distance teaching,…

  13. A Boundary Value Problem for Introductory Physics?

    ERIC Educational Resources Information Center

    Grundberg, Johan

    2008-01-01

    The Laplace equation has applications in several fields of physics, and problems involving this equation serve as paradigms for boundary value problems. In the case of the Laplace equation in a disc there is a well-known explicit formula for the solution: Poisson's integral. We show how one can derive this formula, and in addition two equivalent…

  14. Accelerating Innovation: How Nuclear Physics Benefits Us All

    DOE R&D Accomplishments Database

    2011-01-01

    Innovation has been accelerated by nuclear physics in the areas of improving our health; making the world safer; electricity, environment, archaeology; better computers; contributions to industry; and training the next generation of innovators.

  15. Summary for astrophysics and non-accelerator physics

    SciTech Connect

    Kahana, S.H.

    1988-01-01

    This paper summarizes the presentations at the astrophysics and non-accelerator physics conference. Discussed in this paper are: supernovae, neutrinos, x-rays, gamma rays, cosmic rays, monopoles and primordial nucleosynthesis. 15 refs. (LSP)

  16. Solving large-scale sparse eigenvalue problems and linear systems of equations for accelerator modeling

    SciTech Connect

    Gene Golub; Kwok Ko

    2009-03-30

    The solutions of sparse eigenvalue problems and linear systems constitute one of the key computational kernels in the discretization of partial differential equations for the modeling of linear accelerators. The computational challenges faced by existing techniques for solving those sparse eigenvalue problems and linear systems call for continuing research to improve on the algorithms so that ever increasing problem size as required by the physics application can be tackled. Under the support of this award, the filter algorithm for solving large sparse eigenvalue problems was developed at Stanford to address the computational difficulties in the previous methods with the goal to enable accelerator simulations on then the world largest unclassified supercomputer at NERSC for this class of problems. Specifically, a new method, the Hemitian skew-Hemitian splitting method, was proposed and researched as an improved method for solving linear systems with non-Hermitian positive definite and semidefinite matrices.

  17. Physics of Laser-driven plasma-based acceleration

    SciTech Connect

    Esarey, Eric; Schroeder, Carl B.

    2003-06-30

    The physics of plasma-based accelerators driven by short-pulse lasers is reviewed. This includes the laser wake-field accelerator, the plasma beat wave accelerator, the self-modulated laser wake-field accelerator, and plasma waves driven by multiple laser pulses. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse direction, electron dephasing, laser pulse energy depletion, as well as beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and plasmas with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Recent experimental results are summarized.

  18. Accelerator physics analysis with an integrated toolkit

    SciTech Connect

    Holt, J.A.; Michelotti, L.; Satogata, T.

    1992-08-01

    Work is in progress on an integrated software toolkit for linear and nonlinear accelerator design, analysis, and simulation. As a first application, ``beamline`` and ``MXYZPTLK`` (differential algebra) class libraries, were used with an X Windows graphics library to build an user-friendly, interactive phase space tracker which, additionally, finds periodic orbits. This program was used to analyse a theoretical lattice which contains octupoles and decapoles to find the 20th order, stable and unstable periodic orbits and to explore the local phase space structure.

  19. Half-range acceleration for one-dimensional transport problems

    SciTech Connect

    Zika, M.R.; Larsen, E.W.

    1998-12-31

    Researchers have devoted considerable effort to developing acceleration techniques for transport iterations in highly diffusive problems. The advantages and disadvantages of source iteration, rebalance, diffusion synthetic acceleration (DSA), transport synthetic acceleration (TSA), and projection acceleration methods are documented in the literature and will not be discussed here except to note that no single method has proven to be applicable to all situations. Here, the authors describe a new acceleration method that is based solely on transport sweeps, is algebraically linear (and is therefore amenable to a Fourier analysis), and yields a theoretical spectral radius bounded by one-third for all cases. This method does not introduce spatial differencing difficulties (as is the case for DSA) nor does its theoretical performance degrade as a function of mesh and material properties (as is the case for TSA). Practical simulations of the new method agree with the theoretical predictions, except for scattering ratios very close to unity. At this time, they believe that the discrepancy is due to the effect of boundary conditions. This is discussed further.

  20. Particle acceleration, transport and turbulence in cosmic and heliospheric physics

    NASA Technical Reports Server (NTRS)

    Matthaeus, W.

    1992-01-01

    In this progress report, the long term goals, recent scientific progress, and organizational activities are described. The scientific focus of this annual report is in three areas: first, the physics of particle acceleration and transport, including heliospheric modulation and transport, shock acceleration and galactic propagation and reacceleration of cosmic rays; second, the development of theories of the interaction of turbulence and large scale plasma and magnetic field structures, as in winds and shocks; third, the elucidation of the nature of magnetohydrodynamic turbulence processes and the role such turbulence processes might play in heliospheric, galactic, cosmic ray physics, and other space physics applications.

  1. Problems in Teaching Physics at Technical Universities

    NASA Astrophysics Data System (ADS)

    Banik, Ivan; Lukovičová, Jozefa; Pavlendová, Gabriela; Podoba, Rudolf

    2013-12-01

    The paper deals with the problem of decreasing level of knowledge of university students due to the changes of the school system in Slovakia. As the commonly repeated words connected with education in 21st.century are key competencies, we tried to look at the problems and challenges in teaching physics from this point of view. The role of classical experiments in our computerized world is also discussed.

  2. Application of nonlinear Krylov acceleration to radiative transfer problems

    SciTech Connect

    Till, A. T.; Adams, M. L.; Morel, J. E.

    2013-07-01

    The iterative solution technique used for radiative transfer is normally nested, with outer thermal iterations and inner transport iterations. We implement a nonlinear Krylov acceleration (NKA) method in the PDT code for radiative transfer problems that breaks nesting, resulting in more thermal iterations but significantly fewer total inner transport iterations. Using the metric of total inner transport iterations, we investigate a crooked-pipe-like problem and a pseudo-shock-tube problem. Using only sweep preconditioning, we compare NKA against a typical inner / outer method employing GMRES / Newton and find NKA to be comparable or superior. Finally, we demonstrate the efficacy of applying diffusion-based preconditioning to grey problems in conjunction with NKA. (authors)

  3. Enhancing Cognitive Development through Physics Problem Solving: A Taxonomy of Introductory Physics Problems

    NASA Astrophysics Data System (ADS)

    Teodorescu, Raluca; Bennhold, Cornelius; Feldman, Gerald

    2008-10-01

    As part of an ongoing project to reform the introductory algebra-based physics courses at George Washington University, we are developing a taxonomy of introductory physics problems (TIPP) that establishes a connection between the physics problems, the type of physics knowledge they involve and the cognitive processes they develop in students. This taxonomy will provide, besides an algorithm for classifying physics problems, an organized and relatively easy-to-use database of physics problems that contains the majority of already created text-based and research-based types of problems. In addition, this taxonomy will reveal the kinds of physics problems that are still lacking and that are found to be necessary to enhance students' cognitive development. For this reason, we expect it to be a valuable teaching resource for physics instructors which will enable them to select the problems used in their curricular materials based on the specifics of their students' cognition and the learning objectives they want to achieve in their class. This organization scheme will also provide a framework for creating physics-related assessments with a cognitive component.

  4. Conceptual problem solving in high school physics

    NASA Astrophysics Data System (ADS)

    Docktor, Jennifer L.; Strand, Natalie E.; Mestre, José P.; Ross, Brian H.

    2015-12-01

    Problem solving is a critical element of learning physics. However, traditional instruction often emphasizes the quantitative aspects of problem solving such as equations and mathematical procedures rather than qualitative analysis for selecting appropriate concepts and principles. This study describes the development and evaluation of an instructional approach called Conceptual Problem Solving (CPS) which guides students to identify principles, justify their use, and plan their solution in writing before solving a problem. The CPS approach was implemented by high school physics teachers at three schools for major theorems and conservation laws in mechanics and CPS-taught classes were compared to control classes taught using traditional problem solving methods. Information about the teachers' implementation of the approach was gathered from classroom observations and interviews, and the effectiveness of the approach was evaluated from a series of written assessments. Results indicated that teachers found CPS easy to integrate into their curricula, students engaged in classroom discussions and produced problem solutions of a higher quality than before, and students scored higher on conceptual and problem solving measures.

  5. High Energy Density Physics and Exotic Acceleration Schemes

    SciTech Connect

    Cowan, T.; Colby, E.; /SLAC

    2005-09-27

    The High Energy Density and Exotic Acceleration working group took as our goal to reach beyond the community of plasma accelerator research with its applications to high energy physics, to promote exchange with other disciplines which are challenged by related and demanding beam physics issues. The scope of the group was to cover particle acceleration and beam transport that, unlike other groups at AAC, are not mediated by plasmas or by electromagnetic structures. At this Workshop, we saw an impressive advancement from years past in the area of Vacuum Acceleration, for example with the LEAP experiment at Stanford. And we saw an influx of exciting new beam physics topics involving particle propagation inside of solid-density plasmas or at extremely high charge density, particularly in the areas of laser acceleration of ions, and extreme beams for fusion energy research, including Heavy-ion Inertial Fusion beam physics. One example of the importance and extreme nature of beam physics in HED research is the requirement in the Fast Ignitor scheme of inertial fusion to heat a compressed DT fusion pellet to keV temperatures by injection of laser-driven electron or ion beams of giga-Amp current. Even in modest experiments presently being performed on the laser-acceleration of ions from solids, mega-amp currents of MeV electrons must be transported through solid foils, requiring almost complete return current neutralization, and giving rise to a wide variety of beam-plasma instabilities. As keynote talks our group promoted Ion Acceleration (plenary talk by A. MacKinnon), which historically has grown out of inertial fusion research, and HIF Accelerator Research (invited talk by A. Friedman), which will require impressive advancements in space-charge-limited ion beam physics and in understanding the generation and transport of neutralized ion beams. A unifying aspect of High Energy Density applications was the physics of particle beams inside of solids, which is proving to

  6. Spatial visualization in physics problem solving.

    PubMed

    Kozhevnikov, Maria; Motes, Michael A; Hegarty, Mary

    2007-07-01

    Three studies were conducted to examine the relation of spatial visualization to solving kinematics problems that involved either predicting the two-dimensional motion of an object, translating from one frame of reference to another, or interpreting kinematics graphs. In Study 1, 60 physics-naíve students were administered kinematics problems and spatial visualization ability tests. In Study 2, 17 (8 high- and 9 low-spatial ability) additional students completed think-aloud protocols while they solved the kinematics problems. In Study 3, the eye movements of fifteen (9 high- and 6 low-spatial ability) students were recorded while the students solved kinematics problems. In contrast to high-spatial students, most low-spatial students did not combine two motion vectors, were unable to switch frames of reference, and tended to interpret graphs literally. The results of the study suggest an important relationship between spatial visualization ability and solving kinematics problems with multiple spatial parameters. PMID:21635308

  7. Open problems in condensed matter physics, 1987

    SciTech Connect

    Falicov, L.M.

    1988-08-01

    The 1970's and 1980's can be considered the third stage in the explosive development of condensed matter physics. After the very intensive research of the 1930's and 1940's, which followed the formulation of quantum mechanics, and the path-breaking activity of the 1950's and 1960's, the problems being faced now are much more complex and not always susceptible to simple modelling. The (subjectively) open problems discussed here are: high temperature superconductivity, its properties and the possible new mechanisms which lead to it; the integral and fractional quantum Hall effects; new forms of order in condensed-matter systems; the physics of disorder, especially the problem of spin glasses; the physics of complex anisotropic systems; the theoretical prediction of stable and metastable states of matter; the physics of highly correlated states (heavy fermions); the physics of artificially made structures, in particular heterostructures and highly metastable states of matter; the determination of the microscopic structure of surfaces; and chaos and highly nonlinear phnomena. 82 refs.

  8. Beam Physics of Integrable Optics Test Accelerator at Fermilab

    SciTech Connect

    Nagaitsev, S.; Valishev, A.; Danilov, V.V.; Shatilov, D.N.; /Novosibirsk, IYF

    2012-05-01

    Fermilab's Integrable Optics Test Accelerator (IOTA) is an electron storage ring designed for testing advanced accelerator physics concepts, including implementation of nonlinear integrable beam optics and experiments on optical stochastic cooling. The machine is currently under construction at the Advanced Superconducting Test Accelerator facility. In this report we present the goals and the current status of the project, and describe the details of machine design. In particular, we concentrate on numerical simulations setting the requirements on the design and supporting the choice of machine parameters.

  9. Statistical Physics of Hard Optimization Problems

    NASA Astrophysics Data System (ADS)

    Zdeborová, Lenka

    2008-06-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the NP-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this thesis is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

  10. Statistical physics of hard optimization problems

    NASA Astrophysics Data System (ADS)

    Zdeborová, Lenka

    2009-06-01

    Optimization is fundamental in many areas of science, from computer science and information theory to engineering and statistical physics, as well as to biology or social sciences. It typically involves a large number of variables and a cost function depending on these variables. Optimization problems in the non-deterministic polynomial (NP)-complete class are particularly difficult, it is believed that the number of operations required to minimize the cost function is in the most difficult cases exponential in the system size. However, even in an NP-complete problem the practically arising instances might, in fact, be easy to solve. The principal question we address in this article is: How to recognize if an NP-complete constraint satisfaction problem is typically hard and what are the main reasons for this? We adopt approaches from the statistical physics of disordered systems, in particular the cavity method developed originally to describe glassy systems. We describe new properties of the space of solutions in two of the most studied constraint satisfaction problems - random satisfiability and random graph coloring. We suggest a relation between the existence of the so-called frozen variables and the algorithmic hardness of a problem. Based on these insights, we introduce a new class of problems which we named "locked" constraint satisfaction, where the statistical description is easily solvable, but from the algorithmic point of view they are even more challenging than the canonical satisfiability.

  11. Parallel Monte Carlo Synthetic Acceleration methods for discrete transport problems

    NASA Astrophysics Data System (ADS)

    Slattery, Stuart R.

    This work researches and develops Monte Carlo Synthetic Acceleration (MCSA) methods as a new class of solution techniques for discrete neutron transport and fluid flow problems. Monte Carlo Synthetic Acceleration methods use a traditional Monte Carlo process to approximate the solution to the discrete problem as a means of accelerating traditional fixed-point methods. To apply these methods to neutronics and fluid flow and determine the feasibility of these methods on modern hardware, three complementary research and development exercises are performed. First, solutions to the SPN discretization of the linear Boltzmann neutron transport equation are obtained using MCSA with a difficult criticality calculation for a light water reactor fuel assembly used as the driving problem. To enable MCSA as a solution technique a group of modern preconditioning strategies are researched. MCSA when compared to conventional Krylov methods demonstrated improved iterative performance over GMRES by converging in fewer iterations when using the same preconditioning. Second, solutions to the compressible Navier-Stokes equations were obtained by developing the Forward-Automated Newton-MCSA (FANM) method for nonlinear systems based on Newton's method. Three difficult fluid benchmark problems in both convective and driven flow regimes were used to drive the research and development of the method. For 8 out of 12 benchmark cases, it was found that FANM had better iterative performance than the Newton-Krylov method by converging the nonlinear residual in fewer linear solver iterations with the same preconditioning. Third, a new domain decomposed algorithm to parallelize MCSA aimed at leveraging leadership-class computing facilities was developed by utilizing parallel strategies from the radiation transport community. The new algorithm utilizes the Multiple-Set Overlapping-Domain strategy in an attempt to reduce parallel overhead and add a natural element of replication to the algorithm. It

  12. Using multiple-possibility physics problems in introductory physics courses

    NASA Astrophysics Data System (ADS)

    Shekoyan, Vazgen

    I have explored the instructional value of using multiple-possibility problems (MPPs) in introductory physics courses. MPPs are different from problems we most often encounter in textbooks. They are different from regular problems since (1) they have missing information, vaguely defined goals or unstated constrains, (2) they possess multiple solutions with multiple criteria for evaluating the solutions, (3) they present uncertainty about which concepts, rules, and principles are necessary for the solution or how they are organized. Real-life problems and professional problems are MPPs. Students rarely encounter such problems in introductory physics courses. Kitchener (1983) proposed a three-level model of cognitive processing to categorize the thinking steps one makes when faced with such problems (cognition, metacognition, epistemic cognition). The critical and distinctive component of MPP solving is epistemic cognition. At that level individuals reflect on the limits of knowing, the certainty of knowing, the underlying assumptions made. It is an important part of thinking in real life. Firstly, I developed and tested a coding scheme for measuring epistemic cognition. Using the coding scheme I compared the epistemic cognition level of experts and novices by conducting think-aloud problem-solving interviews with them. Although experts had higher epistemic cognition level than novices, I documented some instances where a novice showed an expert-like epistemic cognition. I found that prompting question during interviews were 50% effective for students. Secondly, I tested the following two hypotheses by conducting two experimental design and one pre-post treatment design investigations in an algebra-based physics course at Rutgers University: Hypothesis 1: Solving MPPs enhances students' epistemic cognition; Hypothesis 2: Solving MPPs engages students in more meaningful problem solving and thus helps them construct a better conceptual understanding of physics. I found

  13. Geogebra for Solving Problems of Physics

    NASA Astrophysics Data System (ADS)

    Kllogjeri, Pellumb; Kllogjeri, Adrian

    Today is highly speed progressing the computer-based education, which allowes educators and students to use educational programming language and e-tutors to teach and learn, to interact with one another and share together the results of their work. In this paper we will be concentrated on the use of GeoGebra programme for solving problems of physics. We have brought an example from physics of how can be used GeoGebra for finding the center of mass(centroid) of a picture(or system of polygons). After the problem is solved graphically, there is an application of finding the center of a real object(a plate)by firstly, scanning the object and secondly, by inserting its scanned picture into the drawing pad of GeoGebra window and lastly, by finding its centroid. GeoGebra serve as effective tool in problem-solving. There are many other applications of GeoGebra in the problems of physics, and many more in different fields of mathematics.

  14. NASA's Microgravity Fluid Physics Program: Tolerability to Residual Accelerations

    NASA Technical Reports Server (NTRS)

    Skarda, J. Raymond

    1998-01-01

    An overview of the NASA microgravity fluid physics program is presented. The necessary quality of a reduced-gravity environment in terms of tolerable residual acceleration or g levels is a concern that is inevitably raised for each new microgravity experiment. Methodologies have been reported in the literature that provide guidance in obtaining reasonable estimates of residual acceleration sensitivity for a broad range of fluid physics phenomena. Furthermore, a relatively large and growing database of microgravity experiments that have successfully been performed in terrestrial reduced gravity facilities and orbiting platforms exists. Similarity of experimental conditions and hardware, in some cases, lead to new experiments adopting prior experiments g-requirements. Rationale applied to other experiments can, in principle, be a valuable guide to assist new Principal Investigators, PIs, in determining the residual acceleration tolerability of their flight experiments. The availability of g-requirements rationale from prior (mu)g experiments is discussed. An example of establishing g tolerability requirements is demonstrated, using a current microgravity fluid physics flight experiment. The Fluids and Combustion Facility (FCF) which is currently manifested on the US Laboratory of the International Space Station (ISS) will provide opportunities for fluid physics and combustion experiments throughout the life of the ISS. Although the FCF is not intended to accommodate all fluid physics experiments, it is expected to meet the science requirements of approximately 80% of the new PIs that enter the microgravity fluid physics program. The residual acceleration requirements for the FCF fluid physics experiments are based on a set of fourteen reference fluid physics experiments which are discussed.

  15. Future Accelerator Challenges in Support of High-Energy Physics

    SciTech Connect

    Zisman, Michael S.; Zisman, M.S.

    2008-05-03

    Historically, progress in high-energy physics has largely been determined by development of more capable particle accelerators. This trend continues today with the imminent commissioning of the Large Hadron Collider at CERN, and the worldwide development effort toward the International Linear Collider. Looking ahead, there are two scientific areas ripe for further exploration--the energy frontier and the precision frontier. To explore the energy frontier, two approaches toward multi-TeV beams are being studied, an electron-positron linear collider based on a novel two-beam powering system (CLIC), and a Muon Collider. Work on the precision frontier involves accelerators with very high intensity, including a Super-BFactory and a muon-based Neutrino Factory. Without question, one of the most promising approaches is the development of muon-beam accelerators. Such machines have very high scientific potential, and would substantially advance the state-of-the-art in accelerator design. The challenges of the new generation of accelerators, and how these can be accommodated in the accelerator design, are described. To reap their scientific benefits, all of these frontier accelerators will require sophisticated instrumentation to characterize the beam and control it with unprecedented precision.

  16. Particle physics confronts the solar neutrino problem

    SciTech Connect

    Pal, P.B.

    1991-06-01

    This review has four parts. In Part I, we describe the reactions that produce neutrinos in the sun and the expected flux of those neutrinos on the earth. We then discuss the detection of these neutrinos, and how the results obtained differ from the theoretical expectations, leading to what is known as the solar neutrino problem. In Part II, we show how neutrino oscillations can provide a solution to the solar neutrino problem. This includes vacuum oscillations, as well as matter enhanced oscillations. In Part III, we discuss the possibility of time variation of the neutrino flux and how a magnetic moment of the neutrino can solve the problem. WE also discuss particle physics models which can give rise to the required values of magnetic moments. In Part IV, we present some concluding remarks and outlook for the recent future.

  17. Physics of laser-driven plasma-based electron accelerators

    SciTech Connect

    Esarey, E.; Schroeder, C. B.; Leemans, W. P.

    2009-07-15

    Laser-driven plasma-based accelerators, which are capable of supporting fields in excess of 100 GV/m, are reviewed. This includes the laser wakefield accelerator, the plasma beat wave accelerator, the self-modulated laser wakefield accelerator, plasma waves driven by multiple laser pulses, and highly nonlinear regimes. The properties of linear and nonlinear plasma waves are discussed, as well as electron acceleration in plasma waves. Methods for injecting and trapping plasma electrons in plasma waves are also discussed. Limits to the electron energy gain are summarized, including laser pulse diffraction, electron dephasing, laser pulse energy depletion, and beam loading limitations. The basic physics of laser pulse evolution in underdense plasmas is also reviewed. This includes the propagation, self-focusing, and guiding of laser pulses in uniform plasmas and with preformed density channels. Instabilities relevant to intense short-pulse laser-plasma interactions, such as Raman, self-modulation, and hose instabilities, are discussed. Experiments demonstrating key physics, such as the production of high-quality electron bunches at energies of 0.1-1 GeV, are summarized.

  18. Mathematical physics approaches to lightning discharge problems

    NASA Technical Reports Server (NTRS)

    Kyrala, A.

    1985-01-01

    Mathematical physics arguments useful for lightning discharge and generation problems are pursued. A soliton Ansatz for the lightning stroke is treated including a charge generation term which is the ultimate source for the phenomena. Equations are established for a partially ionized plasma inding the effects of pressure, magnetic field, electric field, gravitation, viscosity, and temperature. From these equations is then derived the non-stationary generalized Ohm's Law essential for describing field/current density relationships in the horizon channel of the lightning stroke. The discharge initiation problem is discussed. It is argued that the ionization rate drives both the convective current and electric displacement current to increase exponentially. The statistical distributions of charge in the thundercloud preceding a lightning dischage are considered. The stability of the pre-lightning charge distributions and the use of Boltzmann relaxational equations to determine them are discussed along with a covered impedance path provided by the aircraft.

  19. Cognition of an expert tackling an unfamiliar conceptual physics problem

    NASA Astrophysics Data System (ADS)

    Schuster, David; Undreiu, Adriana

    2009-11-01

    We have investigated and analyzed the cognition of an expert tackling a qualitative conceptual physics problem of an unfamiliar type. Our goal was to elucidate the detailed cognitive processes and knowledge elements involved, irrespective of final solution form, and consider implications for instruction. The basic but non-trivial problem was to find qualitatively the direction of acceleration of a pendulum bob at various stages of its motion, a problem originally studied by Reif and Allen. Methodology included interviews, introspection, retrospection and self-reported metacognition. Multiple facets of cognition were revealed, with different reasoning strategies used at different stages and for different points on the path. An account is given of the zigzag thinking paths and interplay of reasoning modes and schema elements involved. We interpret the cognitive processes in terms of theoretical concepts that emerged, namely: case-based, principle-based, experiential-intuitive and practical-heuristic reasoning; knowledge elements and schemata; activation; metacognition and epistemic framing. The complexity of cognition revealed in this case study contrasts with the tidy principle-based solutions we present to students. The pervasive role of schemata, case-based reasoning, practical heuristic strategies, and their interplay with physics principles is noteworthy, since these aspects of cognition are generally neither recognized nor taught. The schema/reasoning-mode perspective has direct application in science teaching, learning and problem-solving.

  20. Accelerator physics in ERL based polarized electron ion collider

    SciTech Connect

    Hao, Yue

    2015-05-03

    This talk will present the current accelerator physics challenges and solutions in designing ERL-based polarized electron-hadron colliders, and illustrate them with examples from eRHIC and LHeC designs. These challenges include multi-pass ERL design, highly HOM-damped SRF linacs, cost effective FFAG arcs, suppression of kink instability due to beam-beam effect, and control of ion accumulation and fast ion instabilities.

  1. Accelerator Physics Challenges for the NSLS-II Project

    SciTech Connect

    Krinsky,S.

    2009-05-04

    The NSLS-II is an ultra-bright synchrotron light source based upon a 3-GeV storage ring with a 30-cell (15 super-period) double-bend-achromat lattice with damping wigglers used to lower the emittance below 1 nm. In this paper, we discuss the accelerator physics challenges for the design including: optimization of dynamic aperture; estimation of Touschek lifetime; achievement of required orbit stability; and analysis of ring impedance and collective effects.

  2. Physics design of linear accelerators for intense ion beams

    SciTech Connect

    Wangler, T.P.

    1988-01-01

    Advances in the physics and technology of linear accelerators for intense ion beams are leading to new methods for the design of such machines. The physical effects that limit beam current and brightness are better understood and provide the criteria for choosing the rf frequency and for determining optimum focusing configurations to control longitudinal and transverse emittances. During the past decade, the use of developments such as the radio-frequency quadrupole, multiple beams, funneling, ramped-field linac tanks, and self-matching linac tanks is leading to greater design flexibility and improved performance capabilities. 39 refs., 3 tabs., 1 fig.

  3. Future large scale accelerator projects for particle physics

    NASA Astrophysics Data System (ADS)

    Aleksan, R.

    2013-12-01

    The discovery of a new particle, the properties of which are compatible with the expected Brout-Englert-Higgs scalar field in the Standard Model (SM), is the starting point of an intense program for studying its couplings. With this particle, all the components of the SM have now been unraveled. Yet, the existence of dark matter, baryon asymmetry of the Universe and neutrino mass call for new physics at an energy scale, which is not determined so far. Therefore, new large scale accelerators are needed to investigate these mysteries through ultra-high precision measurements and/or the exploration of higher energy frontiers. In the following, we discuss the various accelerator projects aimed at the achievement of the above objectives. The physics reach of these facilities will be briefly described as well as their main technical features and related challenges, highlighting the importance of accelerator R&D not only for the benefit of particle physics but also for other fields of research, and more generally for the society.

  4. COMPASS, the COMmunity Petascale Project for Accelerator Science and Simulation, a broad computational accelerator physics initiative

    SciTech Connect

    J.R. Cary; P. Spentzouris; J. Amundson; L. McInnes; M. Borland; B. Mustapha; B. Norris; P. Ostroumov; Y. Wang; W. Fischer; A. Fedotov; I. Ben-Zvi; R. Ryne; E. Esarey; C. Geddes; J. Qiang; E. Ng; S. Li; C. Ng; R. Lee; L. Merminga; H. Wang; D.L. Bruhwiler; D. Dechow; P. Mullowney; P. Messmer; C. Nieter; S. Ovtchinnikov; K. Paul; P. Stoltz; D. Wade-Stein; W.B. Mori; V. Decyk; C.K. Huang; W. Lu; M. Tzoufras; F. Tsung; M. Zhou; G.R. Werner; T. Antonsen; T. Katsouleas

    2007-06-01

    Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools being developed can be used to predict the dynamics of beams in the presence of optical elements and space charge forces, the calculation of electromagnetic modes and wake fields of cavities, the cooling induced by comoving beams, and the acceleration of beams by intense fields in plasmas generated by beams or lasers. In SciDAC-1, the computational tools had multiple successes in predicting the dynamics of beams and beam generation. In SciDAC-2 these tools will be petascale enabled to allow the inclusion of an unprecedented level of physics for detailed prediction.

  5. COMPASS, the COMmunity Petascale Project for Accelerator Science And Simulation, a Broad Computational Accelerator Physics Initiative

    SciTech Connect

    Cary, J.R.; Spentzouris, P.; Amundson, J.; McInnes, L.; Borland, M.; Mustapha, B.; Norris, B.; Ostroumov, P.; Wang, Y.; Fischer, W.; Fedotov, A.; Ben-Zvi, I.; Ryne, R.; Esarey, E.; Geddes, C.; Qiang, J.; Ng, E.; Li, S.; Ng, C.; Lee, R.; Merminga, L.; /Jefferson Lab /Tech-X, Boulder /UCLA /Colorado U. /Maryland U. /Southern California U.

    2007-11-09

    Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools being developed can be used to predict the dynamics of beams in the presence of optical elements and space charge forces, the calculation of electromagnetic modes and wake fields of cavities, the cooling induced by comoving beams, and the acceleration of beams by intense fields in plasmas generated by beams or lasers. In SciDAC-1, the computational tools had multiple successes in predicting the dynamics of beams and beam generation. In SciDAC-2 these tools will be petascale enabled to allow the inclusion of an unprecedented level of physics for detailed prediction.

  6. COMPASS, the COMmunity Petascale project for Accelerator Science and Simulation, a board computational accelerator physics initiative

    SciTech Connect

    Cary, J.R.; Spentzouris, P.; Amundson, J.; McInnes, L.; Borland, M.; Mustapha, B.; Ostroumov, P.; Wang, Y.; Fischer, W.; Fedotov, A.; Ben-Zvi, I.; Ryne, R.; Esarey, E.; Geddes, C.; Qiang, J.; Ng, E.; Li, S.; Ng, C.; Lee, R.; Merminga, L.; Wang, H.; Bruhwiler, D.L.; Dechow, D.; Mullowney, P.; Messmer, P.; Nieter, C.; Ovtchinnikov, S.; Paul, K.; Stoltz, P.; Wade-Stein, D.; Mori, W.B.; Decyk, V.; Huang, C.K.; Lu, W.; Tzoufras, M.; Tsung, F.; Zhou, M.; Werner, G.R.; Antonsen, T.; Katsouleas, T.; Morris, B.

    2007-07-16

    Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools being developed can be used to predict the dynamics of beams in the presence of optical elements and space charge forces, the calculation of electromagnetic modes and wake fields of cavities, the cooling induced by comoving beams, and the acceleration of beams by intense fields in plasmas generated by beams or lasers. In SciDAC-1, the computational tools had multiple successes in predicting the dynamics of beams and beam generation. In SciDAC-2 these tools will be petascale enabled to allow the inclusion of an unprecedented level of physics for detailed prediction.

  7. COMPASS, the COMmunity petascale project for accelerator science and simulation, a broad computational accelerator physics initiative

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Spentzouris, P.; Amundson, J.; McInnes, L.; Borland, M.; Mustapha, B.; Norris, B.; Ostroumov, P.; Wang, Y.; Fischer, W.; Fedotov, A.; Ben-Zvi, I.; Ryne, R.; Esarey, E.; Geddes, C.; Qiang, J.; Ng, E.; Li, S.; Ng, C.; Lee, R.; Merminga, L.; Wang, H.; Bruhwiler, D. L.; Dechow, D.; Mullowney, P.; Messmer, P.; Nieter, C.; Ovtchinnikov, S.; Paul, K.; Stoltz, P.; Wade-Stein, D.; Mori, W. B.; Decyk, V.; Huang, C. K.; Lu, W.; Tzoufras, M.; Tsung, F.; Zhou, M.; Werner, G. R.; Antonsen, T.; Katsouleas, T.

    2007-07-01

    Accelerators are the largest and most costly scientific instruments of the Department of Energy, with uses across a broad range of science, including colliders for particle physics and nuclear science and light sources and neutron sources for materials studies. COMPASS, the Community Petascale Project for Accelerator Science and Simulation, is a broad, four-office (HEP, NP, BES, ASCR) effort to develop computational tools for the prediction and performance enhancement of accelerators. The tools being developed can be used to predict the dynamics of beams in the presence of optical elements and space charge forces, the calculation of electromagnetic modes and wake fields of cavities, the cooling induced by comoving beams, and the acceleration of beams by intense fields in plasmas generated by beams or lasers. In SciDAC-1, the computational tools had multiple successes in predicting the dynamics of beams and beam generation. In SciDAC-2 these tools will be petascale enabled to allow the inclusion of an unprecedented level of physics for detailed prediction.

  8. Analysis of ANS LWR physics benchmark problems.

    SciTech Connect

    Taiwo, T. A.

    1998-07-29

    Various Monte Carlo and deterministic solutions to the three PWR Lattice Benchmark Problems recently defined by the ANS Ad Hoc Committee on Reactor Physics Benchmarks are presented. These solutions were obtained using the VIM continuous-energy Monte Carlo code and the DIF3D/WIMS-D4M code package implemented at the Argonne National Laboratory. The code results for the K{sub eff} and relative pin power distribution are compared to measured values. Additionally, code results for the three benchmark-prescribed infinite lattice configurations are also intercompared. The results demonstrate that the codes produce very good estimates of both the K{sub eff} and power distribution for the critical core and the lattice parameters of the infinite lattice configuration.

  9. A Course on the Physics of Urban and Environmental Problems

    ERIC Educational Resources Information Center

    Marston, Edwin H.

    1970-01-01

    Presents a physics course for social scientists. Physics problems are presented within the context of several urban and environmental case studies. The problems considered include transportation, air pollution, thermal pollution of water, and scarcity of resources. (LS)

  10. Optical diagnostics for plasma physics and accelerator science: commonalities and differences

    NASA Astrophysics Data System (ADS)

    Meshkov, Oleg

    2016-04-01

    Optical diagnostics are widely used both for experiments of plasma physics and for measurements of parameters of electron/positron beams in accelerators. The approaches applied for these often have the same methodological basis explained by the similarity of the properties of the studied phenomena. Nevertheless, these branches of physics are very specific and require special diagnostics. The possibility of closed contacts and cooperation between scientists solving similar problems in different areas of physics helps to overcome these problems. It is especially typical for BINP SB RAS known by pioneering works on electron-positron colliders and nuclear fusion. This paper describes the diagnostics that are used in plasma physics experiments, especially for plasma heating by a high-current electron beam, and contains a comparison with optical diagnostics which are recognized tools in colliders and storage rings.

  11. VARIATIONAL APPROACH IN WAVELET FRAMEWORK TO POLYNOMIAL APPROXIMATIONS OF NONLINEAR ACCELERATOR PROBLEMS

    SciTech Connect

    FEDOROVA,A.; ZEITLIN,M.; PARSA,Z.

    2000-03-31

    In this paper the authors present applications of methods from wavelet analysis to polynomial approximations for a number of accelerator physics problems. According to a variational approach in the general case they have the solution as a multiresolution (multiscales) expansion on the base of compactly supported wavelet basis. They give an extension of their results to the cases of periodic orbital particle motion and arbitrary variable coefficients. Then they consider more flexible variational method which is based on a biorthogonal wavelet approach. Also they consider a different variational approach, which is applied to each scale.

  12. Physics Problem Solving Using Multiple Views. TR-173.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.; Araya, Agustin A.

    The primary task in solving a physics problem is to select ways of viewing the problem in terms of physical systems whose behavior is described by physical laws. The physical systems are, in general, only approximate models of the real-world systems. As models of real-world systems are made more accurate, the equations involved quickly become…

  13. Screening for Physical Problems in Classrooms for Severely Handicapped Students.

    ERIC Educational Resources Information Center

    Dever, Richard; Knapczyk, Dennis

    1980-01-01

    The authors present a screening device with which teachers of severely handicapped students may detect the presence of a physical problem. The screening approach covers vision, auditory problems, seizures, orthopedic problems, and pain. (CL)

  14. Some physics problems in biological networks

    NASA Astrophysics Data System (ADS)

    Bialek, William

    2007-03-01

    Most of the interesting things that happen in living organisms require interactions among many components, and it is convenient to think of these as a ``network'' of interactions. We use this language at the level of single molecules (the network of interactions among amino acids that determine protein structure), single cells (the network of protein-DNA interactions responsible for the regulation of gene expression) and complex multicellular organisms (the networks of neurons in our brain). In this talk I'll try to look at two very different kinds of theoretical physics problems that arise in thinking about such networks. The first problems are phenomenological: Given what our experimentalists friends can measure, can we generate a global view of network function and dynamics? I'll argue that maximum entropy methods can be useful here, and show how such methods have been used in very recent work on networks of neurons, enzymes, genes and (in disguise) amino acids. In this line of reasoning there are of course interesting connections to statistical mechanics, and we'll see that natural statistical mechanics questions about the underlying models actually teach us something about how the real biological system works, in ways that will be tested through new experiments. In the second half of the talk I'll ask if there are principles from which we might actually be able to predict the structure and dynamics of biological networks. I'll focus on optimization principles, in particular the optimization of information flow in transcriptional regulation. Even setting up these arguments forces us to think critically about our understanding of the signals, specificity and noise in these systems, all current topics of research. Although we don't know if we have the right principles, trying to work out the consequences of such optimization again suggests new experiments.

  15. Operational Radiation Protection in High-Energy Physics Accelerators

    SciTech Connect

    Rokni, S.H.; Fasso, A.; Liu, J.C.; /SLAC

    2012-04-03

    An overview of operational radiation protection (RP) policies and practices at high-energy electron and proton accelerators used for physics research is presented. The different radiation fields and hazards typical of these facilities are described, as well as access control and radiation control systems. The implementation of an operational RP programme is illustrated, covering area and personnel classification and monitoring, radiation surveys, radiological environmental protection, management of induced radioactivity, radiological work planning and control, management of radioactive materials and wastes, facility dismantling and decommissioning, instrumentation and training.

  16. Accelerator-driven molten-salt blankets: Physics issues

    SciTech Connect

    Houts, M.G.; Beard, C.A.; Buksa, J.J.; Davidson, J.W.; Durkee, J.W.; Perry, R.T.; Poston, D.I.

    1994-10-01

    A number of nuclear physics issues concerning the Los Alamos molten-salt accelerator-driven plutonium converter are discussed. General descriptions of several concepts using internal and external moderation are presented. Burnup and salt processing requirement calculations are presented for four concepts, indicating that both the high power density externally moderated concept and an internally moderated concept achieve total plutonium burnups approaching 90% at salt processing rates of less than 2 m{sup 3} per year. Beginning-of-life reactivity temperature coefficients and system kinetic response are also discussed. Future research should investigate the effect of changing blanket composition on operational and safety characteristics.

  17. Using a 400 kV Van de Graaff accelerator to teach physics at West Point

    NASA Astrophysics Data System (ADS)

    Marble, D. K.; Bruch, S. E.; Lainis, T.

    1997-02-01

    A small accelerator visitation laboratory is being built at the United States Military Academy using two 400 kV Van de Graaff accelerators. This laboratory will provide quality teaching experiments and increased research opportunities for both faculty and cadets as well as enhancing the department's ability to teach across the curriculum by using nuclear techniques to solve problems in environmental engineering, material science, archeology, art, etc. This training enhances a students ability to enter non-traditional fields that are becoming a large part of the physics job market. Furthermore, a small accelerator visitation laboratory for high school students can stimulate student interest in science and provide an effective means of communicating the scientific method to a general audience. A discussion of the USMA facility, class experiments and student research projects will be presented.

  18. Applying nonlinear diffusion acceleration to the neutron transport k-Eigenvalue problem with anisotropic scattering

    SciTech Connect

    Willert, Jeffrey; Park, H.; Taitano, William

    2015-10-12

    High-order/low-order (or moment-based acceleration) algorithms have been used to significantly accelerate the solution to the neutron transport k-eigenvalue problem over the past several years. Recently, the nonlinear diffusion acceleration algorithm has been extended to solve fixed-source problems with anisotropic scattering sources. In this paper, we demonstrate that we can extend this algorithm to k-eigenvalue problems in which the scattering source is anisotropic and a significant acceleration can be achieved. Lastly, we demonstrate that the low-order, diffusion-like eigenvalue problem can be solved efficiently using a technique known as nonlinear elimination.

  19. On some theoretical problems of laser wake-field accelerators

    NASA Astrophysics Data System (ADS)

    Bulanov, S. V.; Esirkepov, T. Zh.; Hayashi, Y.; Kiriyama, H.; Koga, J. K.; Kotaki, H.; Mori, M.; Kando, M.

    2016-06-01

    Enhancement of the quality of laser wake-field accelerated (LWFA) electron beams implies the improvement and controllability of the properties of the wake waves generated by ultra-short pulse lasers in underdense plasmas. In this work we present a compendium of useful formulas giving relations between the laser and plasma target parameters allowing one to obtain basic dependences, e.g. the energy scaling of the electrons accelerated by the wake field excited in inhomogeneous media including multi-stage LWFA accelerators. Consideration of the effects of using the chirped laser pulse driver allows us to find the regimes where the chirp enhances the wake field amplitude. We present an analysis of the three-dimensional effects on the electron beam loading and on the unlimited LWFA acceleration in inhomogeneous plasmas. Using the conditions of electron trapping to the wake-field acceleration phase we analyse the multi-equal stage and multiuneven stage LWFA configurations. In the first configuration the energy of fast electrons is a linear function of the number of stages, and in the second case, the accelerated electron energy grows exponentially with the number of stages. The results of the two-dimensional particle-in-cell simulations presented here show the high quality electron acceleration in the triple stage injection-acceleration configuration.

  20. On some theoretical problems of laser wake-field accelerators

    NASA Astrophysics Data System (ADS)

    Bulanov, S. V.; Esirkepov, T. Zh.; Hayashi, Y.; Kiriyama, H.; Koga, J. K.; Kotaki, H.; Mori, M.; Kando, M.

    2016-06-01

    > Enhancement of the quality of laser wake-field accelerated (LWFA) electron beams implies the improvement and controllability of the properties of the wake waves generated by ultra-short pulse lasers in underdense plasmas. In this work we present a compendium of useful formulas giving relations between the laser and plasma target parameters allowing one to obtain basic dependences, e.g. the energy scaling of the electrons accelerated by the wake field excited in inhomogeneous media including multi-stage LWFA accelerators. Consideration of the effects of using the chirped laser pulse driver allows us to find the regimes where the chirp enhances the wake field amplitude. We present an analysis of the three-dimensional effects on the electron beam loading and on the unlimited LWFA acceleration in inhomogeneous plasmas. Using the conditions of electron trapping to the wake-field acceleration phase we analyse the multi-equal stage and multiuneven stage LWFA configurations. In the first configuration the energy of fast electrons is a linear function of the number of stages, and in the second case, the accelerated electron energy grows exponentially with the number of stages. The results of the two-dimensional particle-in-cell simulations presented here show the high quality electron acceleration in the triple stage injection-acceleration configuration.

  1. A theoretical perspective on particle acceleration by interplanetary shocks and the Solar Energetic Particle problem

    NASA Astrophysics Data System (ADS)

    Verkhoglyadova, Olga P.; Zank, Gary P.; Li, Gang

    2015-02-01

    Understanding the physics of Solar Energetic Particle (SEP) events is of importance to the general question of particle energization throughout the cosmos as well as playing a role in the technologically critical impact of space weather on society. The largest, and often most damaging, events are the so-called gradual SEP events, generally associated with shock waves driven by coronal mass ejections (CMEs). We review the current state of knowledge about particle acceleration at evolving interplanetary shocks with application to SEP events that occur in the inner heliosphere. Starting with a brief outline of recent theoretical progress in the field, we focus on current observational evidence that challenges conventional models of SEP events, including complex particle energy spectra, the blurring of the distinction between gradual and impulsive events, and the difference inherent in particle acceleration at quasi-parallel and quasi-perpendicular shocks. We also review the important problem of the seed particle population and its injection into particle acceleration at a shock. We begin by discussing the properties and characteristics of non-relativistic interplanetary shocks, from their formation close to the Sun to subsequent evolution through the inner heliosphere. The association of gradual SEP events with shocks is discussed. Several approaches to the energization of particles have been proposed, including shock drift acceleration, diffusive shock acceleration (DSA), acceleration by large-scale compression regions, acceleration by random velocity fluctuations (sometimes known as the "pump mechanism"), and others. We review these various mechanisms briefly and focus on the DSA mechanism. Much of our emphasis will be on our current understanding of the parallel and perpendicular diffusion coefficients for energetic particles and models of plasma turbulence in the vicinity of the shock. Because of its importance both to the DSA mechanism itself and to the particle

  2. International Linear Collider Accelerator Physics R&D

    SciTech Connect

    George D. Gollin; Michael Davidsaver; Michael J. Haney; Michael Kasten; Jason Chang; Perry Chodash; Will Dluger; Alex Lang; Yehan Liu

    2008-09-03

    ILC work at Illinois has concentrated primarily on technical issues relating to the design of the accelerator. Because many of the problems to be resolved require a working knowledge of classical mechanics and electrodynamics, most of our research projects lend themselves well to the participation of undergraduate research assistants. The undergraduates in the group are scientists, not technicians, and find solutions to problems that, for example, have stumped PhD-level staff elsewhere. The ILC Reference Design Report calls for 6.7 km circumference damping rings (which prepare the beams for focusing) using “conventional” stripline kickers driven by fast HV pulsers. Our primary goal was to determine the suitability of the 16 MeV electron beam in the AØ region at Fermilab for precision kicker studies.We found that the low beam energy and lack of redundancy in the beam position monitor system complicated the analysis of our data. In spite of these issues we concluded that the precision we could obtain was adequate to measure the performance and stability of a production module of an ILC kicker, namely 0.5%. We concluded that the kicker was stable to an accuracy of ~2.0% and that we could measure this precision to an accuracy of ~0.5%. As a result, a low energy beam like that at AØ could be used as a rapid-turnaround facility for testing ILC production kicker modules. The ILC timing precision for arrival of bunches at the collision point is required to be 0.1 picosecond or better. We studied the bunch-to-bunch timing accuracy of a “phase detector” installed in AØ in order to determine its suitability as an ILC bunch timing device. A phase detector is an RF structure excited by the passage of a bunch. Its signal is fed through a 1240 MHz high-Q resonant circuit and then down-mixed with the AØ 1300 MHz accelerator RF. We used a kind of autocorrelation technique to compare the phase detector signal with a reference signal obtained from the phase detector

  3. Age, Physical Activity, Physical Fitness, Body Composition, and Incidence of Orthopedic Problems.

    ERIC Educational Resources Information Center

    Research Quarterly for Exercise and Sport, 1989

    1989-01-01

    Effects of age, physical activity, physical fitness, and body mass index (BMI) on the occurrence of orthopedic problems were examined. For men, physical fitness, BMI, and physical activity were associated with orthopedic problems; for women, physical activity was the main predictor. Age was not a factor for either gender. (JD)

  4. Resource Letter AFHEP-1: Accelerators for the Future of High-Energy Physics

    NASA Astrophysics Data System (ADS)

    Barletta, William A.

    2012-02-01

    This Resource Letter provides a guide to literature concerning the development of accelerators for the future of high-energy physics. Research articles, books, and Internet resources are cited for the following topics: motivation for future accelerators, present accelerators for high-energy physics, possible future machine, and laboratory and collaboration websites.

  5. ASP2012: Fundamental Physics and Accelerator Sciences in Africa

    NASA Astrophysics Data System (ADS)

    Darve, Christine

    2012-02-01

    Much remains to be done to improve education and scientific research in Africa. Supported by the international scientific community, our initiative has been to contribute to fostering science in sub-Saharan Africa by establishing a biennial school on fundamental subatomic physics and its applications. The school is based on a close interplay between theoretical, experimental, and applied physics. The lectures are addressed to students or young researchers with at least a background of 4 years of university formation. The aim of the school is to develop capacity, interpret, and capitalize on the results of current and future physics experiments with particle accelerators; thereby spreading education for innovation in related applications and technologies, such as medicine and information science. Following the worldwide success of the first school edition, which gathered 65 students for 3-week in Stellenbosch (South Africa) in August 2010, the second edition will be hosted in Ghana from July 15 to August 4, 2012. The school is a non-profit organization, which provides partial or full financial support to 50 of the selected students, with priority to Sub-Saharan African students.

  6. Problem Orientation in Physical Geography Teaching.

    ERIC Educational Resources Information Center

    Church, Michael

    1988-01-01

    States that the introduction of real, quantitative problems in classroom and field teaching improves scientific rigor and leads more directly to applied studies. Examines the use of problems in an introductory hydrology course, presenting teaching objectives and the full course structure to illustrate their integration with other teaching modes.…

  7. Accelerated solution of non-linear flow problems using Chebyshev iteration polynomial based RK recursions

    SciTech Connect

    Lorber, A.A.; Carey, G.F.; Bova, S.W.; Harle, C.H.

    1996-12-31

    The connection between the solution of linear systems of equations by iterative methods and explicit time stepping techniques is used to accelerate to steady state the solution of ODE systems arising from discretized PDEs which may involve either physical or artificial transient terms. Specifically, a class of Runge-Kutta (RK) time integration schemes with extended stability domains has been used to develop recursion formulas which lead to accelerated iterative performance. The coefficients for the RK schemes are chosen based on the theory of Chebyshev iteration polynomials in conjunction with a local linear stability analysis. We refer to these schemes as Chebyshev Parameterized Runge Kutta (CPRK) methods. CPRK methods of one to four stages are derived as functions of the parameters which describe an ellipse {Epsilon} which the stability domain of the methods is known to contain. Of particular interest are two-stage, first-order CPRK and four-stage, first-order methods. It is found that the former method can be identified with any two-stage RK method through the correct choice of parameters. The latter method is found to have a wide range of stability domains, with a maximum extension of 32 along the real axis. Recursion performance results are presented below for a model linear convection-diffusion problem as well as non-linear fluid flow problems discretized by both finite-difference and finite-element methods.

  8. Analyzing the many skills involved in solving complex physics problems

    NASA Astrophysics Data System (ADS)

    Adams, Wendy K.; Wieman, Carl E.

    2015-05-01

    We have empirically identified over 40 distinct sub-skills that affect a person's ability to solve complex problems in many different contexts. The identification of so many sub-skills explains why it has been so difficult to teach or assess problem solving as a single skill. The existence of these sub-skills is supported by several studies comparing a wide range of individuals' strengths and weaknesses in these sub-skills, their "problem solving fingerprint," while solving different types of problems including a classical mechanics problem, quantum mechanics problems, and a complex trip-planning problem with no physics. We see clear differences in the problem solving fingerprint of physics and engineering majors compared to the elementary education majors that we tested. The implications of these findings for guiding the teaching and assessing of problem solving in physics instruction are discussed.

  9. Using Analogy to Solve a Three-Step Physics Problem

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Yin; Singh, Chandralekha

    2010-10-01

    In a companion paper, we discuss students' ability to take advantage of what they learn from a solved problem and transfer their learning to solve a quiz problem that has different surface features but the same underlying physics principles. Here, we discuss students' ability to perform analogical reasoning between another pair of problems. Both the problems can be solved using the same physics principles. However, the solved problem provided was a two-step problem (which can be solved by decomposing it into two sub-problems) while the quiz problem was a three-step problem. We find that it is challenging for students to extend what they learned from a two-step problem to solve a three-step problem.

  10. Atomic Physics with Accelerators: Projectile Electron Spectroscopy (APAPES)

    NASA Astrophysics Data System (ADS)

    Madesis, I.; Dimitriou, A.; Laoutaris, A.; Lagoyannis, A.; Axiotis, M.; Mertzimekis, T.; Andrianis, M.; Harissopulos, S.; Benis, E. P.; Sulik, B.; Valastyán, I.; Zouros, T. J. M.

    2015-01-01

    The new research initiative APAPES (http://apapes.physics.uoc.gr/) has already established a new experimental station with a beam line dedicated for atomic collisions physics research, at the 5 MV TANDEM accelerator of the National Research Centre "Demokritos" in Athens, Greece. A complete zero-degree Auger projectile spectroscopy (ZAPS) apparatus has been put together to perform high resolution studies of electrons emitted in ion-atom collisions. A single stage hemispherical spectrometer with a 2-dimensional Position Sensitive Detector (PSD) combined with a doubly-differentially pumped gas target will be used to perform a systematic isoelectronic investigation of K-Auger spectra emitted from collisions of preexcited and ground state He-like ions with gas targets using novel techniques. Our intention is to provide a more thorough understanding of cascade feeding of the 1s2s2p 4P metastable states produced by electron capture in collisions of He-like ions with gas targets and further elucidate their role in the non-statistical production of excited three-electron 1s2s2p states by electron capture, recently a field of conflicting interpretations awaiting further resolution. At the moment, the apparatus is being completed and the spectrometer will soon be fully operational. Here we present the project progress and the recent high resolution spectrum obtained in collisions of 12 MeV C4+ on a Neon gas target.

  11. Key problems in black hole physics today

    NASA Astrophysics Data System (ADS)

    Joshi, Pankaj S.

    2011-12-01

    We review here some of the major open issues and challenges in black hole physics today, and the current progress on the same. It is pointed out that to secure a concrete foundation for the basic theory as well as astrophysical applications for black hole physics, it is essential to gain a suitable insight into these questions. In particular, we discuss the recent results investigating the final fate of a massive star within the framework of the Einstein gravity, and the stability and genericity aspects of the gravitational collapse outcomes in terms of black holes and naked singularities. Recent developments such as spinning up a black hole by throwing matter into it, and physical effects near naked singularities are considered. It is pointed out that some of the new results obtained in recent years in the theory of gravitational collapse imply interesting possibilities and understanding for the theoretical advances in gravity as well as towards new astrophysical applications.

  12. Key problems in black hole physics today

    NASA Astrophysics Data System (ADS)

    Joshi, Pankaj S.

    2011-03-01

    We review here some of the major open issues and challenges in black hole physics today, and the current progress on the same. It is pointed out that to secure a concrete foundation for the basic theory as well as astrophysical applications for black hole physics, it is essential to gain a suitable insight into these questions. In particular, we discuss the recent results investigating the final fate of a massive star within the framework of the Einstein gravity, and the stability and genericity aspects of the gravitational collapse outcomes in terms of black holes and naked singularities. Recent developments such as spinning up a black hole by throwing matter into it, and physical effects near naked singularities are considered. It is pointed out that some of the new results obtained in recent years in the theory of gravitational collapse imply interesting possibilities and understanding for the theoretical advances in gravity as well as towards new astrophysical applications.

  13. Topics in radiation at accelerators: Radiation physics for personnel and environmental protection

    SciTech Connect

    Cossairt, J.D.

    1996-10-01

    In the first chapter, terminology, physical and radiological quantities, and units of measurement used to describe the properties of accelerator radiation fields are reviewed. The general considerations of primary radiation fields pertinent to accelerators are discussed. The primary radiation fields produced by electron beams are described qualitatively and quantitatively. In the same manner the primary radiation fields produced by proton and ion beams are described. Subsequent chapters describe: shielding of electrons and photons at accelerators; shielding of proton and ion accelerators; low energy prompt radiation phenomena; induced radioactivity at accelerators; topics in radiation protection instrumentation at accelerators; and accelerator radiation protection program elements.

  14. Phenomenographic Study of Students' Problem Solving Approaches in Physics

    ERIC Educational Resources Information Center

    Walsh, Laura N.; Howard, Robert G.; Bowe, Brian

    2007-01-01

    This paper describes ongoing research investigating student approaches to quantitative and qualitative problem solving in physics. This empirical study was conducted using a phenomenographic approach to analyze data from individual semistructured problem solving interviews with 22 introductory college physics students. The main result of the study…

  15. Role of Multiple Representations in Physics Problem Solving

    ERIC Educational Resources Information Center

    Maries, Alexandru

    2013-01-01

    This thesis explores the role of multiple representations in introductory physics students' problem solving performance through several investigations. Representations can help students focus on the conceptual aspects of physics and play a major role in effective problem solving. Diagrammatic representations can play a particularly important role…

  16. Instruction Emphasizing Effort Improves Physics Problem Solving

    ERIC Educational Resources Information Center

    Li, Daoquan

    2012-01-01

    Effectively using strategies to solve complex problems is an important educational goal and is implicated in successful academic performance. However, people often do not spontaneously use the effective strategies unless they are motivated to do so. The present study was designed to test whether educating students about the importance of effort in…

  17. A Descriptive Study of Cooperative Problem Solving Introductory Physics Labs

    ERIC Educational Resources Information Center

    Knutson, Paul Aanond

    2011-01-01

    The purpose of this study was to determine the ways in which cooperative problem solving in physics instructional laboratories influenced the students' ability to provide qualitative responses to problems. The literature shows that problem solving involves both qualitative and quantitative skills. Qualitative skills are important because those…

  18. Internet Computer Coaches for Introductory Physics Problem Solving

    ERIC Educational Resources Information Center

    Xu Ryan, Qing

    2013-01-01

    The ability to solve problems in a variety of contexts is becoming increasingly important in our rapidly changing technological society. Problem-solving is a complex process that is important for everyday life and crucial for learning physics. Although there is a great deal of effort to improve student problem solving skills throughout the…

  19. Transformation Theory, Accelerating Frames, and Two Simple Problems

    ERIC Educational Resources Information Center

    Schmid, G. Bruno

    1977-01-01

    Presents an operator which transforms quantum functions to solve problems of the stationary state wave functions for a particle and the motion and spreading of a Gaussian wave packet in uniform gravitational fields. (SL)

  20. Intuitive reasoning about abstract and familiar physics problems

    NASA Technical Reports Server (NTRS)

    Kaiser, Mary Kister; Jonides, John; Alexander, Joanne

    1986-01-01

    Previous research has demonstrated that many people have misconceptions about basic properties of motion. Two experiments examined whether people are more likely to produce dynamically correct predictions about basic motion problems involving situations with which they are familiar, and whether solving such problems enhances performance on a subsequent abstract problem. In experiment 1, college students were asked to predict the trajectories of objects exiting a curved tube. Subjects were more accurate on the familiar version of the problem, and there was no evidence of transfer to the abstract problem. In experiment 2, two familiar problems were provided in an attempt to enhance subjects' tendency to extract the general structure of the problems. Once again, they gave more correct responses to the familiar problems but failed to generalize to the abstract problem. Formal physics training was associated with correct predictions for the abstract problem but was unrelated to performance on the familiar problems.

  1. James Clerk Maxwell Prize for Plasma Physics: The Physics of Magnetic Reconnection and Associated Particle Acceleration

    NASA Astrophysics Data System (ADS)

    Drake, James

    2010-11-01

    Solar and stellar flares, substorms in the Earth's magnetosphere, and disruptions in laboratory fusion experiments are driven by the explosive release of magnetic energy through the process of magnetic reconnection. During reconnection oppositely directed magnetic fields break and cross-connect. The resulting magnetic slingshots convert magnetic energy into high velocity flows, thermal energy and energetic particles. A major scientific challenge has been the multi-scale nature of the problem: a narrow boundary layer, ``the dissipation region,'' breaks field lines and controls the release of energy in a macroscale system. Significant progress has been made on fundamental questions such as how magnetic energy is released so quickly and why the release occurs as an explosion. At the small spatial scales of the dissipation region the motion of electrons and ions decouples, the MHD description breaks down and whistler and kinetic Alfven dynamics drives reconnection. The dispersive property of these waves leads to fast reconnection, insensitive to system size and weakly dependent on dissipation, consistent with observations. The evidence for these waves during reconnection in the magnetosphere and the laboratory is compelling. The role of turbulence within the dissipation region in the form of ``secondary islands'' or as a source of anomalous resistivity continues to be explored. A large fraction of the magnetic energy released during reconnection appears in the form of energetic electrons and protons -- up to 50% or more during solar flares. The mechanism for energetic particle production during magnetic reconnection has remained a mystery. Models based on reconnection at a single large x-line are incapable of producing the large numbers of energetic electrons seen in observations. Scenarios based on particle acceleration in a multi-x-line environment are more promising. In such models a link between the energy gain of electrons and the magnetic energy released, a

  2. The ‘Physics Cup’: interesting problems are difficult

    NASA Astrophysics Data System (ADS)

    Kalda, J.

    2013-07-01

    An overview of the online competition, Physics Cup—IPhO2012 is given. This preceded the 43rd International Physics Olympiad and included ten problems, published monthly. Three problems, the most popular among the contestants, are discussed in detail. These problems deal with laser speckle patterns, geometrical optics and LC circuits with four degrees of freedom. The results of the competition and of the poll carried out among the contestants are used to discuss the relationship between the properties of the problems: difficulty, closeness to reality and beauty (as perceived by the contestants).

  3. CMFD acceleration of spatial domain-decomposed neutron transport problems

    SciTech Connect

    Kelley, B. W.; Larsen, E. W.

    2012-07-01

    A significant limitation to parallelizing the solution of neutron transport problems is the need for sweeps across the entirety of the problem domain. Angular domain decomposition is common practice, as the equations for each direction are independent aside from their shared scattering/fission source. Accordingly, spatial domain decomposition does not naturally arise in the transport equations and is therefore less frequent in practice. In this paper, we show that a neutron transport domain can be straightforwardly divided into independent, parallelizable sweep regions, globally linked with the standard CMFD method, with an additional update equation. We verify, theoretically (via Fourier analysis) and computationally, that the convergence properties of this method are stable and nominally as rapid as standard CMFD. (authors)

  4. Accelerator mass spectrometry: from nuclear physics to dating

    SciTech Connect

    Kutschera, W.

    1983-01-01

    Several applications of accelerator-based mass spectroscopy are reviewed. Among these are the search for unknown species, determination of comogenic radioisotopes in natural materials and measurements of half-lifes, especially those of significance to dating. Accelerator parameters and techniques of importance for these applications are also considered.

  5. Childhood physical punishment and problem solving in marriage.

    PubMed

    Cast, Alicia D; Schweingruber, David; Berns, Nancy

    2006-02-01

    Drawing from social learning theories and symbolic interactionist understandings of social life, the authors suggest that physical punishment teaches aggressive and controlling strategies for solving the problems of living together and hinders the development of important problem-solving skills, specifically the ability to role take with others. These strategies and skills become part of an individual's toolkit for problem resolution within his or her marriage. The analysis is based on 188 married couples in Washington State who participated in a longitudinal study of the first 2 years of marriage. The analysis reveals the following: Individuals who were physically punished during childhood are more likely to engage in physical and verbal aggression with their spouses, individuals who were physically punished during childhood are more controlling with their spouses, and individuals who were physically punished during childhood are less able to take their spouse's perspective. PMID:16368764

  6. Why students still can't solve physics problems after solving over 2000 problems

    NASA Astrophysics Data System (ADS)

    Byun, Taejin; Lee, Gyoungho

    2014-09-01

    This study investigates the belief that solving a large number of physics problems helps students better learn physics. We investigated the number of problems solved, student confidence in solving these problems, academic achievement, and the level of conceptual understanding of 49 science high school students enrolled in upper-level physics classes from Spring 2010 to Summer 2011. The participants solved an average of 2200 physics problems before entering high school. Despite having solved so many problems, no statistically significant correlation was found between the number of problems solved and academic achievement on either a mid-term or physics competition examination. In addition, no significant correlation was found between the number of physics problems solved and performance on the Force Concept Inventory (FCI). Lastly, four students were selected from the 49 participants with varying levels of experience and FCI scores for a case study. We determined that their problem solving and learning strategies was more influential in their success than the number of problems they had solved.

  7. MAUVE: A New Strategy for Solving and Grading Physics Problems

    NASA Astrophysics Data System (ADS)

    Hill, Nicole Breanne

    2016-05-01

    MAUVE (magnitude, answer, units, variables, and equations) is a framework and rubric to help students and teachers through the process of clearly solving and assessing solutions to introductory physics problems. Success in introductory physics often derives from an understanding of units, a command over dimensional analysis, and good bookkeeping. I developed MAUVE for an introductory-level environmental physics course as an easy-to-remember checklist to help students construct organized and thoughtful solutions to physics problems. Environmental physics is a core physics course for environmental and sustainability science (ESS) majors that teaches principles of radiation, thermodynamics, and mechanics within the context of the environment and sustainable energy systems. ESS student concentrations include environmental biology, applied ecology, biogeochemistry, and natural resources. The MAUVE rubric, inspired by nature, has encouraged my students to produce legible and tactical work, and has significantly clarified the grading process.

  8. Judgments of physics problem difficulty among experts and novices

    NASA Astrophysics Data System (ADS)

    Fakcharoenphol, Witat; Morphew, Jason W.; Mestre, José P.

    2015-12-01

    Students' ability to effectively study for an exam, or to manage their time during an exam, is related to their metacognitive capacity. Prior research has demonstrated the effective use of metacognitive strategies during learning and retrieval is related to content expertise. Students also make judgments of their own learning and of problem difficulty to guide their studying. This study extends prior research by investigating the accuracy of novices' and experts' ability to judge problem difficulty across two experiments; here "accuracy" refers to whether or not their judgments of problem difficulty corresponds with actual exam performance in an introductory mechanics physics course. In the first experiment, physics education research (PER) experts judged the difficulty of introductory physics problems and provided the rationales behind their judgments. Findings indicate that experts use a number of different problem features to make predictions of problem difficulty. While experts are relatively accurate in judging problem difficulty, their content expertise may interfere with their ability to predict student performance on some question types. In the second experiment novices and "near experts" (graduate TAs) judged which question from a problem pair (taken from a real exam) was more difficult. The results indicate that judgments of problem difficulty are more accurate for those with greater content expertise, suggesting that the ability to predict problem difficulty is a trait of expertise which develops with experience.

  9. Teachers' and Students' Preliminary Stages in Physics Problem Solving

    ERIC Educational Resources Information Center

    Mansyur, Jusman

    2015-01-01

    This paper describes the preliminary stages in physics problem-solving related to the use of external representation. This empirical study was carried out using a phenomenographic approach to analyze data from individual thinking-aloud and interviews with 8 senior high school students and 7 physics teachers. The result of this study is a set of…

  10. MAUVE: A New Strategy for Solving and Grading Physics Problems

    ERIC Educational Resources Information Center

    Hill, Nicole Breanne

    2016-01-01

    MAUVE (magnitude, answer, units, variables, and equations) is a framework and rubric to help students and teachers through the process of clearly solving and assessing solutions to introductory physics problems. Success in introductory physics often derives from an understanding of units, a command over dimensional analysis, and good bookkeeping.…

  11. Status and future prospects for United States accelerators and accelerator physics

    SciTech Connect

    Siemann, R.H

    1994-12-01

    The recent performance and future prospects of accelerators in the United States are reviewed. The next decade promises significant improvements and major new facilities. There is uncertainty beyond that because of the SSC cancellation and the new, enhanced importance of international accelerator projects.

  12. Future Prospects of Accelerator Science for Particle Physics

    SciTech Connect

    Seryi, Andrei; /SLAC

    2012-06-15

    Future advances in understanding fundamental questions of nature require revolutionary developments in accelerator science to allow several orders of magnitude enhancements in terms of energy, intensity, faster timing, and higher resolution. The challenges of the 21st century (energy, power, environment, resources, cost, and space) also play a significant role in the development of accelerator tools. In this overview article, we consider several recent developments and ideas that may become steps in addressing the challenges and which may find their way into designs of accelerator tools of the future.

  13. Childhood Physical Punishment and Problem Solving in Marriage

    ERIC Educational Resources Information Center

    Cast, Alicia D.; Schweingruber, David; Berns, Nancy

    2006-01-01

    Drawing from social learning theories and symbolic interactionist understandings of social life, the authors suggest that physical punishment teaches aggressive and controlling strategies for solving the problems of living together and hinders the development of important problem-solving skills, specifically the ability to role take with others.…

  14. Partially Specified Physics Problems: University Students' Attitudes and Performance

    ERIC Educational Resources Information Center

    Marusic, M.; Erceg, N.; Slisko, J.

    2011-01-01

    In this research we asked the fourth year students (N = 50) of a technical faculty of the University of Split (Republic of Croatia) to solve a partially specified physics problem related to gravitational force. The task for the students was to decide whether the situation described in the problem is feasible or not. Nevertheless, the formulation…

  15. The Importance of Monitoring Skills in Physics Problem Solving

    ERIC Educational Resources Information Center

    Ali, Marlina; Talib, Corrienna-Abd; Hasniza Ibrahim, Nor; Surif, Johari; Halim Abdullah, Abdul

    2016-01-01

    The purpose of this paper is to show how important "monitoring" is as metacognitive skills in solving physics problems in the field mechanics. Based on test scores, twenty one students were divided into two groups: more successful (MS) and less successful (LS) problem solvers. Students were allowed to think-aloud while they worked on…

  16. XXII International Baldin Seminar on High Energy Physics Problems

    NASA Astrophysics Data System (ADS)

    The XXII International Baldin Seminar on High Energy Physics Problems "Relativistic Nuclear Physics and Quantum Chromodynamics", organized by the Joint Institute for Nuclear Research was held from September 15 to 20, 2014 in Dubna, Russia. The Seminar continues the series of traditional meetings and was established by an outstanding scientist Academician A.M. Baldin(1926-2001). Among conferences that were organized by Alexander Mikhailovich Baldin of special importance is just this series of the International Seminars on High-Energy Physics Problems started in 1969 with support of M.A. Markov (1908-1994). They have been given an inofficial, somewhat witty, name "Baldin autumn".

  17. Physics design of the DARHT 2nd axis accelerator cell

    SciTech Connect

    Chen, Y J; Houck, T L; Reginato, L J; Shang, C C; Yu, S S

    1999-08-19

    The next generation of radiographic machines based on induction accelerators require very high brightness electron beams to realize the desired x-ray spot size and intensity. This high brightness must be maintained throughout the beam transport, from source to x-ray converter target. The accelerator for the second-axis of the Dual Axis Radiographic Hydrodynamic Test (DARHT) facility is being designed to accelerate a 4-kA, 2-{micro}s pulse of electrons to 20 MeV. After acceleration, the 2-{micro}s pulse will be chopped into a train of four 50-ns pulses with variable temporal spacing by rapidly deflecting the beam between a beam stop and the final transport section. The short beam pulses will be focused onto an x-ray converter target generating four radiographic pulses within the 2-{micro}s window. Beam instability due to interaction with the accelerator cells can very adversely effect the beam brightness and radiographic pulse quality. This paper describes the various issues considered in the design of the accelerator cell with emphasis on transverse impedance and minimizing beam instabilities.

  18. A descriptive study of cooperative problem solving introductory physics labs

    NASA Astrophysics Data System (ADS)

    Knutson, Paul Aanond

    The purpose of this study was to determine the ways in which cooperative problem solving in physics instructional laboratories influenced the students' ability to provide qualitative responses to problems. The literature shows that problem solving involves both qualitative and quantitative skills. Qualitative skills are important because those skills are the foundation for the quantitative aspects of problem solving. (Chi, et al., 1981). The literature also indicates that cooperative problem solving should enhance the students' performance. As a practical matter surveys of departments that require introductory physics classes expect their students to have general qualitative problem solving skills. The students in this study were asked to solve problem(s) before coming to a lab session and then cooperatively assess whether or not their answers were correct by conducting a laboratory activity for which they had to plan the procedure and obtain the necessary results. TA's were expected to provide instruction under a cognitive apprenticeship model. The results showed that the cooperative problem solving laboratories had almost no impact on the students' problem solving skills as measured from the start of a two hour lab session to the end of the lab session...The reason for this may have been that students did not have enough experience in the solving of different kinds of problems in the two domains of Newton's second Law and gravitation to overcome their misconceptions and become competent. Another possibility was that the TA's did not follow the cognitive apprenticeship model as consistently as might have been needed.

  19. Solution accelerators for large scale 3D electromagnetic inverse problems

    SciTech Connect

    Newman, Gregory A.; Boggs, Paul T.

    2004-04-05

    We provide a framework for preconditioning nonlinear 3D electromagnetic inverse scattering problems using nonlinear conjugate gradient (NLCG) and limited memory (LM) quasi-Newton methods. Key to our approach is the use of an approximate adjoint method that allows for an economical approximation of the Hessian that is updated at each inversion iteration. Using this approximate Hessian as a preconditoner, we show that the preconditioned NLCG iteration converges significantly faster than the non-preconditioned iteration, as well as converging to a data misfit level below that observed for the non-preconditioned method. Similar conclusions are also observed for the LM iteration; preconditioned with the approximate Hessian, the LM iteration converges faster than the non-preconditioned version. At this time, however, we see little difference between the convergence performance of the preconditioned LM scheme and the preconditioned NLCG scheme. A possible reason for this outcome is the behavior of the line search within the LM iteration. It was anticipated that, near convergence, a step size of one would be approached, but what was observed, instead, were step lengths that were nowhere near one. We provide some insights into the reasons for this behavior and suggest further research that may improve the performance of the LM methods.

  20. Probing new physics with underground accelerators and radioactive sources

    NASA Astrophysics Data System (ADS)

    Izaguirre, Eder; Krnjaic, Gordan; Pospelov, Maxim

    2015-01-01

    New light, weakly coupled particles can be efficiently produced at existing and future high-intensity accelerators and radioactive sources in deep underground laboratories. Once produced, these particles can scatter or decay in large neutrino detectors (e.g. Super-K and Borexino) housed in the same facilities. We discuss the production of weakly coupled scalars ϕ via nuclear de-excitation of an excited element into the ground state in two viable concrete reactions: the decay of the 0+ excited state of 16O populated via a (p , α) reaction on fluorine and from radioactive 144Ce decay where the scalar is produced in the de-excitation of 144Nd*, which occurs along the decay chain. Subsequent scattering on electrons, e (ϕ , γ) e, yields a mono-energetic signal that is observable in neutrino detectors. We show that this proposed experimental setup can cover new territory for masses 250 keV ≤mϕ ≤ 2me and couplings to protons and electrons, 10-11 ≤gegp ≤10-7. This parameter space is motivated by explanations of the 'proton charge radius puzzle', thus this strategy adds a viable new physics component to the neutrino and nuclear astrophysics programs at underground facilities. For the LUNA-type setup, we show that such light particles can be efficiently produced by populating the first excited 6.05 MeV 0+ state of 16O in (p , α) reactions on fluorine. For the SOX-type setup we find similarly powerful sensitivity from the 144Ce-144Pr (νbare) radioactive source, which can produce a scalar with 2.19 or 1.49 MeV energies from the Nd144* de-excitation that occurs along the decay chain. The subsequent detection of a mono-energetic release in a Borexino-type detector with 6.05, 2.19, or 1.49 MeV will be free from substantial environmental backgrounds. The strategy proposed in this Letter is capable of advancing the sensitivity to such states by many orders of magnitude, completely covering the parameter space relevant for the rp puzzle.

  1. Statistical physics of hard combinatorial optimization: Vertex cover problem

    NASA Astrophysics Data System (ADS)

    Zhao, Jin-Hua; Zhou, Hai-Jun

    2014-07-01

    Typical-case computation complexity is a research topic at the boundary of computer science, applied mathematics, and statistical physics. In the last twenty years, the replica-symmetry-breaking mean field theory of spin glasses and the associated message-passing algorithms have greatly deepened our understanding of typical-case computation complexity. In this paper, we use the vertex cover problem, a basic nondeterministic-polynomial (NP)-complete combinatorial optimization problem of wide application, as an example to introduce the statistical physical methods and algorithms. We do not go into the technical details but emphasize mainly the intuitive physical meanings of the message-passing equations. A nonfamiliar reader shall be able to understand to a large extent the physics behind the mean field approaches and to adjust the mean field methods in solving other optimization problems.

  2. A comparison of acceleration methods for solving the neutron transport k-eigenvalue problem

    SciTech Connect

    Willert, Jeffrey; Park, H.; Knoll, D.A.

    2014-10-01

    Over the past several years a number of papers have been written describing modern techniques for numerically computing the dominant eigenvalue of the neutron transport criticality problem. These methods fall into two distinct categories. The first category of methods rewrite the multi-group k-eigenvalue problem as a nonlinear system of equations and solve the resulting system using either a Jacobian-Free Newton–Krylov (JFNK) method or Nonlinear Krylov Acceleration (NKA), a variant of Anderson Acceleration. These methods are generally successful in significantly reducing the number of transport sweeps required to compute the dominant eigenvalue. The second category of methods utilize Moment-Based Acceleration (or High-Order/Low-Order (HOLO) Acceleration). These methods solve a sequence of modified diffusion eigenvalue problems whose solutions converge to the solution of the original transport eigenvalue problem. This second class of methods is, in our experience, always superior to the first, as most of the computational work is eliminated by the acceleration from the LO diffusion system. In this paper, we review each of these methods. Our computational results support our claim that the choice of which nonlinear solver to use, JFNK or NKA, should be secondary. The primary computational savings result from the implementation of a HOLO algorithm. We display computational results for a series of challenging multi-dimensional test problems.

  3. A comparison of acceleration methods for solving the neutron transport k-eigenvalue problem

    NASA Astrophysics Data System (ADS)

    Willert, Jeffrey; Park, H.; Knoll, D. A.

    2014-10-01

    Over the past several years a number of papers have been written describing modern techniques for numerically computing the dominant eigenvalue of the neutron transport criticality problem. These methods fall into two distinct categories. The first category of methods rewrite the multi-group k-eigenvalue problem as a nonlinear system of equations and solve the resulting system using either a Jacobian-Free Newton-Krylov (JFNK) method or Nonlinear Krylov Acceleration (NKA), a variant of Anderson Acceleration. These methods are generally successful in significantly reducing the number of transport sweeps required to compute the dominant eigenvalue. The second category of methods utilize Moment-Based Acceleration (or High-Order/Low-Order (HOLO) Acceleration). These methods solve a sequence of modified diffusion eigenvalue problems whose solutions converge to the solution of the original transport eigenvalue problem. This second class of methods is, in our experience, always superior to the first, as most of the computational work is eliminated by the acceleration from the LO diffusion system. In this paper, we review each of these methods. Our computational results support our claim that the choice of which nonlinear solver to use, JFNK or NKA, should be secondary. The primary computational savings result from the implementation of a HOLO algorithm. We display computational results for a series of challenging multi-dimensional test problems.

  4. Assessing Student Expertise in Introductory Physics with Isomorphic Problems. I. Performance on Nonintuitive Problem Pair from Introductory Physics

    ERIC Educational Resources Information Center

    Singh, Chandralekha

    2008-01-01

    Investigations related to expertise in problem solving and ability to transfer learning from one context to another are important for developing strategies to help students perform more expertlike tasks. Here we analyze written responses to a pair of nonintuitive isomorphic problems given to introductory physics students and discussions with a…

  5. Formation and Acceleration Physics on Plasma Injector 1

    NASA Astrophysics Data System (ADS)

    Howard, Stephen

    2012-10-01

    Plasma Injector 1 (PI-1) is a two stage coaxial Marshal gun with conical accelerator electrodes, similar in shape to the MARAUDER device, with power input of the same topology as the RACE device. The goal of PI-1 research is to produce a self-confined compact toroid with high-flux (200 mWb), high-density (3x10^16 cm-3) and moderate initial temperature (100 eV) to be used as the target plasma in a MTF reactor. PI-1 is 5 meters long and 1.9 m in diameter at the expansion region where a high aspect ratio (4.4) spheromak is formed with a minimum lambda of 9 m-1. The acceleration stage is 4 m long and tapers to an outer diameter of 40 cm. The capacitor banks store 0.5 MJ for formation and 1.13 MJ for acceleration. Power is delivered via 62 independently controlled switch modules. Several geometries for formation bias field, inner electrodes and target chamber have been tested, and trends in accelerator efficiency and target lifetime have been observed. Thomson scattering and ion Doppler spectroscopy show significant heating (>100 eV) as the CT is compressed in the conical accelerator. B-dot probes show magnetic field structure consistent with Grad-Shafranov models and MHD simulations, and CT axial length depends strongly on the lambda profile.

  6. Representational Format, Student Choice, and Problem Solving in Physics

    NASA Astrophysics Data System (ADS)

    Kohl, P. B.; Finkelstein, N. D.

    2005-09-01

    Student problem-solving ability appears to be tied to the representational format of the problem (math, pictorial, graphical, verbal). In a study of a 367-student algebra-based physics class, we examine student problem solving ability on homework problems given in four different representational formats, with problems as close to isomorphic as possible. In addition, we examine students' capacity for assessing their own representational competence by giving follow-up quizzes in which the students can choose between various problem formats. We report student performance and consider factors that may influence their ability or choices. As a control, part of the class was assigned a random-format follow-up quiz where students received quiz formats at random. We find that there are statistically significant performance differences between isomorphic problems. We also find that allowing students to choose which representational format they use improves student performance under some circumstances and degrades it in others.

  7. Representation use and strategy choice in physics problem solving

    NASA Astrophysics Data System (ADS)

    De Cock, Mieke

    2012-12-01

    In this paper, we examine student success on three variants of a test item given in different representational formats (verbal, pictorial, and graphical), with an isomorphic problem statement. We confirm results from recent papers where it is mentioned that physics students’ problem-solving competence can vary with representational format and that solutions can be triggered by particular details of the representation. Previous studies are complemented with a fine grained analysis of solution strategies. We find that students use different problem-solving strategies, depending on the representational format in which the problem is stated.

  8. Linear accelerator for production of tritium: Physics design challenges

    SciTech Connect

    Wangler, T.P.; Lawrence, G.P.; Bhatia, T.S.; Billen, J.H.; Chan, K.C.D.; Garnett, R.W.; Guy, F.W.; Liska, D.; Nath, S.; Neuschaefer, G.; Shubaly, M.

    1990-01-01

    In the summer of 1989, a collaboration between Los Alamos National Laboratory and Brookhaven National Laboratory conducted a study to establish a reference design of a facility for accelerator production of tritium (APT). The APT concept is that of a neutron-spallation source, which is based on the use of high-energy protons to bombard lead nuclei, resulting in the production of large quantities of neutrons. Neutrons from the lead are captured by lithium to produce tritium. This paper describes the design of a 1.6-GeV, 250-mA proton cw linear accelerator for APT.

  9. GPU-based acceleration of free energy calculations in solid state physics

    NASA Astrophysics Data System (ADS)

    Januszewski, Michał; Ptok, Andrzej; Crivelli, Dawid; Gardas, Bartłomiej

    2015-07-01

    Obtaining a thermodynamically accurate phase diagram through numerical calculations is a computationally expensive problem that is crucially important to understanding the complex phenomena of solid state physics, such as superconductivity. In this work we show how this type of analysis can be significantly accelerated through the use of modern GPUs. We illustrate this with a concrete example of free energy calculation in multi-band iron-based superconductors, known to exhibit a superconducting state with oscillating order parameter (OP). Our approach can also be used for classical BCS-type superconductors. With a customized algorithm and compiler tuning we are able to achieve a 19×speedup compared to the CPU (119×compared to a single CPU core), reducing calculation time from minutes to mere seconds, enabling the analysis of larger systems and the elimination of finite size effects.

  10. Reflection on problem solving in introductory and advanced physics

    NASA Astrophysics Data System (ADS)

    Mason, Andrew J.

    Reflection is essential in order to learn from problem solving. This thesis explores issues related to how reflective students are and how we can improve their capacity for reflection on problem solving. We investigate how students naturally reflect in their physics courses about problem solving and evaluate strategies that may teach them reflection as an integral component of problem-solving. Problem categorization based upon similarity of solution is a strategy to help them reflect about the deep features of the problems related to the physics principles involved. We find that there is a large overlap between the introductory and graduate students in their ability to categorize. Moreover, introductory students in the calculus-based courses performed better categorization than those in the algebra-based courses even though the categorization task is conceptual. Other investigations involved exploring if reflection could be taught as a skill on individual and group levels. Explicit self-diagnosis in recitation investigated how effectively students could diagnose their own errors on difficult problems, how much scaffolding was necessary for this purpose, and how effective transfer was to other problems employing similar principles. Difficulty in applying physical principles and difference between the self-diagnosed and transfer problems affected performance. We concluded that a sustained intervention is required to learn effective problem-solving strategies. Another study involving reflection on problem solving with peers suggests that those who reflected with peers drew more diagrams and had a larger gain from the midterm to final exam. Another study in quantum mechanics involved giving common problems in midterm and final exams and suggested that advanced students do not automatically reflect on their mistakes. Interviews revealed that even advanced students often focus mostly on exams rather than learning and building a robust knowledge structure. A survey was

  11. Complex network problems in physics, computer science and biology

    NASA Astrophysics Data System (ADS)

    Cojocaru, Radu Ionut

    There is a close relation between physics and mathematics and the exchange of ideas between these two sciences are well established. However until few years ago there was no such a close relation between physics and computer science. Even more, only recently biologists started to use methods and tools from statistical physics in order to study the behavior of complex system. In this thesis we concentrate on applying and analyzing several methods borrowed from computer science to biology and also we use methods from statistical physics in solving hard problems from computer science. In recent years physicists have been interested in studying the behavior of complex networks. Physics is an experimental science in which theoretical predictions are compared to experiments. In this definition, the term prediction plays a very important role: although the system is complex, it is still possible to get predictions for its behavior, but these predictions are of a probabilistic nature. Spin glasses, lattice gases or the Potts model are a few examples of complex systems in physics. Spin glasses and many frustrated antiferromagnets map exactly to computer science problems in the NP-hard class defined in Chapter 1. In Chapter 1 we discuss a common result from artificial intelligence (AI) which shows that there are some problems which are NP-complete, with the implication that these problems are difficult to solve. We introduce a few well known hard problems from computer science (Satisfiability, Coloring, Vertex Cover together with Maximum Independent Set and Number Partitioning) and then discuss their mapping to problems from physics. In Chapter 2 we provide a short review of combinatorial optimization algorithms and their applications to ground state problems in disordered systems. We discuss the cavity method initially developed for studying the Sherrington-Kirkpatrick model of spin glasses. We extend this model to the study of a specific case of spin glass on the Bethe

  12. Transport synthetic acceleration for long-characteristics assembly-level transport problems

    SciTech Connect

    Zika, M.R.; Adams, M.L.

    2000-02-01

    The authors apply the transport synthetic acceleration (TSA) scheme to the long-characteristics spatial discretization for the two-dimensional assembly-level transport problem. This synthetic method employs a simplified transport operator as its low-order approximation. Thus, in the acceleration step, the authors take advantage of features of the long-characteristics discretization that make it particularly well suited to assembly-level transport problems. The main contribution is to address difficulties unique to the long-characteristics discretization and produce a computationally efficient acceleration scheme. The combination of the long-characteristics discretization, opposing reflecting boundary conditions (which are present in assembly-level transport problems), and TSA presents several challenges. The authors devise methods for overcoming each of them in a computationally efficient way. Since the boundary angular data exist on different grids in the high- and low-order problems, they define restriction and prolongation operations specific to the method of long characteristics to map between the two grids. They implement the conjugate gradient (CG) method in the presence of opposing reflection boundary conditions to solve the TSA low-order equations. The CG iteration may be applied only to symmetric positive definite (SPD) matrices; they prove that the long-characteristics discretization yields an SPD matrix. They present results of the acceleration scheme on a simple test problem, a typical pressurized water reactor assembly, and a typical boiling water reactor assembly.

  13. Acceleration of neutrons in a scheme of a tautochronous mathematical pendulum (physical principles)

    SciTech Connect

    Rivlin, Lev A

    2010-12-09

    We consider the physical principles of neutron acceleration through a multiple synchronous interaction with a gradient rf magnetic field in a scheme of a tautochronous mathematical pendulum. (laser applications and other aspects of quantum electronics)

  14. Home environmental problems and physical function in Taiwanese older adults.

    PubMed

    Lan, Tzuo-Yun; Wu, Shwu-Chong; Chang, Wen-Chiung; Chen, Ching-Yu

    2009-01-01

    Environmental hazards play an important role in the disablement process. The purpose of this study was to investigate the relationship between home environmental problems and personal physical function. Data were based on a two-stage nationwide survey and evaluation on the needs of long-term care in Taiwan. A total of 10,596 individuals aged 65 and over were included in this study. These participants were identified with physical or cognitive problems at the screening interview and further evaluated at the second interview on health condition, functional status, needs of long-term care, and home environmental problems. Six items of environmental hazards were assessed at the participants' homes with direct observation. The prevalence rates of home environmental problems were similar among older adults with different levels of physical function. No grab bars (79.6-85.1%) and no protections against slip (81.9-92.8%) in the bathroom were two commonly present hazards in older adults' homes. Older adults with a higher income (Odds ratio=OR=0.75), without income information (OR=0.78) or living with other persons (OR=0.74) were less likely to experience environmental problems at home. Results from this study revealed that home environment condition was associated with factors other than personal disabling conditions for the elderly. Modifying home environment, especially the bathroom, should be attached with great importance for physically disabled older adults. PMID:19124167

  15. Studies of visual attention in physics problem solving

    NASA Astrophysics Data System (ADS)

    Madsen, Adrian M.

    The work described here represents an effort to understand and influence visual attention while solving physics problems containing a diagram. Our visual system is guided by two types of processes -- top-down and bottom-up. The top-down processes are internal and determined by ones prior knowledge and goals. The bottom-up processes are external and determined by features of the visual stimuli such as color, and luminance contrast. When solving physics problems both top-down and bottom-up processes are active, but to varying degrees. The existence of two types of processes opens several interesting questions for physics education. For example, how do bottom-up processes influence problem solvers in physics? Can we leverage these processes to draw attention to relevant diagram areas and improve problem-solving? In this dissertation we discuss three studies that investigate these open questions and rely on eye movements as a primary data source. We assume that eye movements reflect a person's moment-to-moment cognitive processes, providing a window into one's thinking. In our first study, we compared the way correct and incorrect solvers viewed relevant and novice-like elements in a physics problem diagram. We found correct solvers spent more time attending to relevant areas while incorrect solvers spent more time looking at novice-like areas. In our second study, we overlaid these problems with dynamic visual cues to help students' redirect their attention. We found that in some cases these visual cues improved problem-solving performance and influenced visual attention. To determine more precisely how the perceptual salience of diagram elements influenced solvers' attention, we conducted a third study where we manipulated the perceptual salience of the diagram elements via changes in luminance contrast. These changes did not influence participants' answers or visual attention. Instead, similar to our first study, the time spent looking in various areas of the

  16. Active Physics Problem Based Learning for High Schools

    NASA Astrophysics Data System (ADS)

    Eisenkraft, Arthur

    2006-12-01

    Active Physics bridges research and practice. This NSF supported curriculum project uses a 7E instructional model and a problem based learning approach. Students learn physics on a need to know basis as they construct solutions to challenges such as developing a sport that can be played on the moon, creating an appliance package for developing countries, designing a light and sound show, or building a museum exhibit. In addition to meeting the content requirements of an introductory physics course, there is also an emphasis on engineering design principles and on essential questions. The excitement and frustration of trying to bridge research and practice will be discussed.

  17. Physics of beam self-modulation in plasma wakefield accelerators

    SciTech Connect

    Lotov, K. V.

    2015-10-15

    The self-modulation instability is a key effect that makes possible the usage of nowadays proton beams as drivers for plasma wakefield acceleration. Development of the instability in uniform plasmas and in plasmas with a small density up-step is numerically studied with the focus at nonlinear stages of beam evolution. The step parameters providing the strongest established wakefield are found, and the mechanism of stable bunch train formation is identified.

  18. Seeing the Nature of the Accelerating Physics: It's a SNAP

    SciTech Connect

    Albert, J.; Aldering, G.; Allam, S.; Althouse, W.; Amanullah, R.; Annis, J.; Astier, P.; Aumeunier, M.; Bailey, S.; Baltay, C.; Barrelet, E.; Basa, S.; Bebek, C.; Bergstom, L.; Bernstein, G.; Bester, M.; Besuner, B.; Bigelow, B.; Blandford, R.; Bohlin, R.; Bonissent, A.; /Caltech /LBL, Berkeley /Fermilab /SLAC /Stockholm U. /Paris, IN2P3 /Marseille, CPPM /Marseille, Lab. Astrophys. /Yale U. /Pennsylvania U. /UC, Berkeley /Michigan U. /Baltimore, Space Telescope Sci. /Indiana U. /Caltech, JPL /Australian Natl. U., Canberra /American Astron. Society /Chicago U. /Cambridge U. /Saclay /Lyon, IPN

    2005-08-05

    For true insight into the nature of dark energy, measurements of the precision and accuracy of the Supernova/Acceleration Probe (SNAP) are required. Precursor or scaled-down experiments are unavoidably limited, even for distinguishing the cosmological constant. They can pave the way for, but should not delay, SNAP by developing calibration, refinement, and systematics control (and they will also provide important, exciting astrophysics).

  19. Synergia: a modern tool for accelerator physics simulation

    SciTech Connect

    Spentzouris, P.; Amundson, J.; /Fermilab

    2004-10-01

    High precision modeling of space-charge effects, together with accurate treatment of single-particle dynamics, is essential for designing future accelerators as well as optimizing the performance of existing machines. Synergia is a high-fidelity parallel beam dynamics simulation package with fully three dimensional space-charge capabilities and a higher order optics implementation. We describe the computational techniques, the advanced human interface, and the parallel performance obtained using large numbers of macroparticles.

  20. Inflationary Expansions Generated by a Physically Real Kinematic Acceleration

    NASA Astrophysics Data System (ADS)

    Savickas, David

    2010-02-01

    A repulsive cosmological acceleration is shown to exist that exhibits a behavior very similar to that found in both inflationary models at the time of origin of the universe, and also in the repulsive acceleration found in present-day cosmological observations. It is able to describe an inflationary model of a radiation universe in considerable numerical detail. It is based on a method that defines the Hubble parameter H, and consequently inertial systems themselves, directly in terms of the positions and velocities of mass particles in a universe. This makes it possible to describe a mass particle's motion relative to other particles in the universe, rather than relative to inertial systems. Because of this, the repulsive acceleration is a real kinematic effect existing in the present-day universe. This definition of H cannot include the use of photon positions or velocities because H determines the velocities of receding inertial systems of galaxies, and the velocity of a photon in a distant inertial system then depends on the definition of H itself. Therefore, at the time of its origin the magnitude of H in a radiation dominated universe would be solely determined by the behavior of the relatively few mass particles that it contained while allowing for a near balance with the gravitation of the Friedmann-Lemaître model. )

  1. Role of multiple representations in physics problem solving

    NASA Astrophysics Data System (ADS)

    Maries, Alexandru

    This thesis explores the role of multiple representations in introductory physics students' problem solving performance through several investigations. Representations can help students focus on the conceptual aspects of physics and play a major role in effective problem solving. Diagrammatic representations can play a particularly important role in the initial stages of conceptual analysis and planning of the problem solution. Findings suggest that students who draw productive diagrams are more successful problem solvers even if their approach is primarily mathematical. Furthermore, students provided with a diagram of the physical situation presented in a problem sometimes exhibited deteriorated performance. Think-aloud interviews suggest that this deteriorated performance is in part due to reduced conceptual planning time which caused students to jump to the implementation stage without fully understanding the problem and planning problem solution. Another study investigated two interventions aimed at improving introductory students' representational consistency between mathematical and graphical representations and revealed that excessive scaffolding can have a detrimental effect. The detrimental effect was partly due to increased cognitive load brought on by the additional steps and instructions. Moreover, students who exhibited representational consistency also showed improved problem solving performance. The final investigation is centered on a problem solving task designed to provide information about the pedagogical content knowledge (PCK) of graduate student teaching assistants (TAs). In particular, the TAs identified what they considered to be the most common difficulties of introductory physics students related to graphical representations of kinematics concepts as they occur in the Test of Understanding Graphs in Kinematics (TUG-K). As an extension, the Force Concept Inventory (FCI) was also used to assess this aspect of PCK related to knowledge of

  2. Compressed modes for variational problems in mathematics and physics

    PubMed Central

    Ozoliņš, Vidvuds; Lai, Rongjie; Caflisch, Russel; Osher, Stanley

    2013-01-01

    This article describes a general formalism for obtaining spatially localized (“sparse”) solutions to a class of problems in mathematical physics, which can be recast as variational optimization problems, such as the important case of Schrödinger’s equation in quantum mechanics. Sparsity is achieved by adding an regularization term to the variational principle, which is shown to yield solutions with compact support (“compressed modes”). Linear combinations of these modes approximate the eigenvalue spectrum and eigenfunctions in a systematically improvable manner, and the localization properties of compressed modes make them an attractive choice for use with efficient numerical algorithms that scale linearly with the problem size. PMID:24170861

  3. Problems experienced and envisioned for dynamical physical systems

    NASA Technical Reports Server (NTRS)

    Ryan, R. S.

    1985-01-01

    The use of high performance systems, which is the trend of future space systems, naturally leads to lower margins and a higher sensitivity to parameter variations and, therefore, more problems of dynamical physical systems. To circumvent dynamic problems of these systems, appropriate design, verification analysis, and tests must be planned and conducted. The basic design goal is to define the problem before it occurs. The primary approach for meeting this goal is a good understanding and reviewing of the problems experienced in the past in terms of the system under design. This paper reviews many of the dynamic problems experienced in space systems design and operation, categorizes them as to causes, and envisions future program implications, developing recommendations for analysis and test approaches.

  4. Problem Solving: Physics Modeling-Based Interactive Engagement

    ERIC Educational Resources Information Center

    Ornek, Funda

    2009-01-01

    The purpose of this study was to investigate how modeling-based instruction combined with an interactive-engagement teaching approach promotes students' problem solving abilities. I focused on students in a calculus-based introductory physics course, based on the matter and interactions curriculum of Chabay & Sherwood (2002) at a large state…

  5. Studies of Visual Attention in Physics Problem Solving

    ERIC Educational Resources Information Center

    Madsen, Adrian M.

    2013-01-01

    The work described here represents an effort to understand and influence visual attention while solving physics problems containing a diagram. Our visual system is guided by two types of processes--top-down and bottom-up. The top-down processes are internal and determined by ones prior knowledge and goals. The bottom-up processes are external and…

  6. Understanding Student Use of Differentials in Physics Integration Problems

    ERIC Educational Resources Information Center

    Hu, Dehui; Rebello, N. Sanjay

    2013-01-01

    This study focuses on students' use of the mathematical concept of differentials in physics problem solving. For instance, in electrostatics, students need to set up an integral to find the electric field due to a charged bar, an activity that involves the application of mathematical differentials (e.g., "dr," "dq"). In…

  7. Fundamentals of Physics, 6th Edition Enhanced Problems Version

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2002-04-01

    No other text on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics. This text continues to outperform the competition year after year, and the new edition will be no exception. Intended for Calculus-based Physics courses, the 6th edition of this extraordinary text is a major redesign of the best-selling 5th edition, which still maintains many of the elements that led to its enormous success. Jearl Walker adds his unique style to this edition with the addition of new problems designed to capture, and keep, students' attention. Nearly all changes are based on suggestions from instructors and students using the 5th edition, from reviewer comments, and from research done on the process of learning. The primary goal of this text is to provide students with a solid understanding of fundamental physics concepts, and to help them apply this conceptual understanding to quantitative problem solving. The principal goal of Halliday-Resnick-Walker is to provide instructors with a tool by which they can teach students how to effectively read scientific material and successfully reason through scientific questions. To sharpen this tool, the Enhanced Problems Version of the sixth edition of Fundamentals of Physics contains over 1000 new, high-quality problems that require thought and reasoning rather than simplistic plugging of data into formulas.

  8. Video-based problems in introductory mechanics physics courses

    NASA Astrophysics Data System (ADS)

    Gröber, Sebastian; Klein, Pascal; Kuhn, Jochen

    2014-09-01

    Introductory mechanics physics courses at the transition from school to university are a challenge for students. They are faced with an abrupt and necessary increase of theoretical content and requirements on their conceptual understanding of phyiscs. In order to support this transition we replaced part of the mandatory weekly theory-based paper-and-pencil problems with video analysis problems of equal content and level of difficulty. Video-based problems (VBP) are a new problem format for teaching physics from a linked sequence of theoretical and video-based experimental tasks. Experimental tasks are related to the well-known concept of video motion analysis. This introduction of an experimental part in recitations allows the establishment of theory-experiment interplay as well as connections between physical content and context fields such as nature, technique, everyday life and applied physics by conducting model-and context-related experiments. Furthermore, laws and formulas as predominantly representative forms are extended by the use of diagrams and vectors. In this paper we give general reasons for this approach, describe the structure and added values of VBP, and show that they cover a relevant part of mechanics courses at university. Emphasis is put on theory-experiment interplay as a structural added value of VBP to promote students' construction of knowledge and conceptual understanding.

  9. Aspects of the Cognitive Model of Physics Problem Solving.

    ERIC Educational Resources Information Center

    Brekke, Stewart E.

    Various aspects of the cognitive model of physics problem solving are discussed in detail including relevant cues, encoding, memory, and input stimuli. The learning process involved in the recognition of familiar and non-familiar sensory stimuli is highlighted. Its four components include selection, acquisition, construction, and integration. The…

  10. Laser-based acceleration for nuclear physics experiments at ELI-NP

    NASA Astrophysics Data System (ADS)

    Tesileanu, O.; Asavei, Th.; Dancus, I.; Gales, S.; Negoita, F.; Turcu, I. C. E.; Ursescu, D.; Zamfir, N. V.

    2016-05-01

    As part of the Extreme Light pan-European research infrastructure, Extreme Light Infrastructure - Nuclear Physics (ELI-NP) in Romania will focus on topics in Nuclear Physics, fundamental Physics and applications, based on very intense photon beams. Laser-based acceleration of electrons, protons and heavy ions is a prerequisite for a multitude of laser-driven nuclear physics experiments already proposed by the international research community. A total of six outputs of the dual-amplification chain laser system, two of 100TW, two of 1PW and two of 10PW will be employed in 5 experimental areas, with the possibility to use long and short focal lengths, gas and solid targets, reaching the whole range of laser acceleration processes. We describe the main techniques and expectations regarding the acceleration of electrons, protons and heavy nuclei at ELI-NP, and some physics cases for which these techniques play an important role in the experiments.

  11. ACCELERATOR PHYSICS MODEL OF EXPECTED BEAM LOSS ALONG THE SNS ACCELERATOR FACILITY DURING NORMAL OPERATION.

    SciTech Connect

    CATALAN - LASHERAS,N.; COUSINEAU,S.; GALAMBOS,J.; HOLTKAMP,N.; RAPARIA,D.; SHAFER,R.; STAPLES,J.; STOVALL,J.; TANKE,E.; WANGLER,T.; WEI,J.

    2002-06-03

    The most demanding requirement in the design of the SNS accelerator chain is to keep the accelerator complex under hands-on maintenance. This requirement implies a hard limit for residual radiation below 100 mrem/hr at one feet from the vacuum pipe and four hours after shutdown for hundred days of normal operation. It has been shown by measurements as well as simulation [l] that this limit corresponds to 1-2 Watts/meter average beam losses. This loss level is achievable all around the machine except in specific areas where remote handling will be necessary. These areas have been identified and correspond to collimation sections and dumps where a larger amount of controlled beam loss is foreseen. Even if the average level of loss is kept under 1 W/m, there are circumstances under which transient losses occur in the machine. The prompt radiation or potential damage in the accelerator components can not be deduced from an average beam loss of 1 W/m. At the same time, controlled loss areas require a dedicated study to clarify the magnitude and distribution of the beam loss. From the front end to the target, we have estimated the most probable locations for transient losses and given an estimate of their magnitude and frequency. This information is essential to calculate the necessary shielding or determine the safety procedures during machine operation. Losses in controlled areas, and the cleaning systems are the subject of Section 2. The inefficiency of each system will be taken into account for the discussion on Section 3 where n controlled loss is estimated. Section 4 summarizes our findings and presents a global view of the losses along the accelerator chain.

  12. Understanding student use of differentials in physics integration problems

    NASA Astrophysics Data System (ADS)

    Hu, Dehui; Rebello, N. Sanjay

    2013-12-01

    This study focuses on students’ use of the mathematical concept of differentials in physics problem solving. For instance, in electrostatics, students need to set up an integral to find the electric field due to a charged bar, an activity that involves the application of mathematical differentials (e.g., dr, dq). In this paper we aim to explore students’ reasoning about the differential concept in physics problems. We conducted group teaching or learning interviews with 13 engineering students enrolled in a second-semester calculus-based physics course. We amalgamated two frameworks—the resources framework and the conceptual metaphor framework—to analyze students’ reasoning about differential concept. Categorizing the mathematical resources involved in students’ mathematical thinking in physics provides us deeper insights into how students use mathematics in physics. Identifying the conceptual metaphors in students’ discourse illustrates the role of concrete experiential notions in students’ construction of mathematical reasoning. These two frameworks serve different purposes, and we illustrate how they can be pieced together to provide a better understanding of students’ mathematical thinking in physics.

  13. Problem roulette: Studying introductory physics in the cloud

    NASA Astrophysics Data System (ADS)

    Evrard, August E.; Mills, Michael; Winn, David; Jones, Kathryn; Tritz, Jared; McKay, Timothy A.

    2015-01-01

    We introduce Problem Roulette (PR), a web-based study service at the University of Michigan that offers random-within-topic access to a large library of past exam problems in introductory physics courses. Built on public-private cloud infrastructure, PR served nearly 1000 students during Fall 2012 term, delivering more than 60,000 problem pages. The service complements that of commercial publishing houses by offering problems authored by local professors and by explicitly aligning topics with exam content. We describe the service architecture, including reporting and analytical capabilities, and present an initial evaluation of the impact of its use. Among roughly 500 students studying electromagnetism, we find that the 229 students who worked fifty or more problems over the term outperformed their complement by 0.40 grade points (on a 4.0 scale). This improvement partly reflects a selection bias that academically stronger students used the service more frequently. Adjusting for this selection bias, we find a grade point improvement of 0.22, significantly above the random noise level of 0.04. The simple message to students is that working five or more additional problems per week can lead to a quarter-letter grade improvement in introductory physics. Student comments emphasize the importance of randomness in helping them to synthesize concepts. The PR source code is publicly available.

  14. On the physics of waves in the solar atmosphere: Wave heating and wind acceleration

    NASA Technical Reports Server (NTRS)

    Musielak, Z. E.

    1992-01-01

    In the area of solar physics, new calculations of the acoustic wave energy fluxes generated in the solar convective zone was performed. The original theory developed was corrected by including a new frequency factor describing temporal variations of the turbulent energy spectrum. We have modified the original Stein code by including this new frequency factor, and tested the code extensively. Another possible source of the mechanical energy generated in the solar convective zone is the excitation of magnetic flux tube waves which can carry energy along the tubes far away from the region. The problem as to how efficiently those waves are generated in the Sun was recently solved. The propagation of nonlinear magnetic tube waves in the solar atmosphere was calculated, and mode coupling, shock formation, and heating of the local medium was studied. The wave trapping problems and evaluation of critical frequencies for wave reflection in the solar atmosphere was studied. It was shown that the role played by Alfven waves in the wind accelerations and the coronal hole heating is dominant. Presently, we are performing calculations of wave energy fluxes generated in late-type dwarf stars and studying physical processes responsible for the heating of stellar chromospheres and coronae. In the area of physics of waves, a new analytical approach for studying linear Alfven waves in smoothly nonuniform media was recently developed. This approach is presently being extended to study the propagation of linear and nonlinear magnetohydrodynamic (MHD) waves in stratified, nonisothermal and solar atmosphere. The Lighthill theory of sound generation to nonisothermal media (with a special temperature distribution) was extended. Energy cascade by nonlinear MHD waves and possible chaos driven by these waves are presently considered.

  15. Assessing student written problem solutions: A problem-solving rubric with application to introductory physics

    NASA Astrophysics Data System (ADS)

    Docktor, Jennifer L.; Dornfeld, Jay; Frodermann, Evan; Heller, Kenneth; Hsu, Leonardo; Jackson, Koblar Alan; Mason, Andrew; Ryan, Qing X.; Yang, Jie

    2016-06-01

    Problem solving is a complex process valuable in everyday life and crucial for learning in the STEM fields. To support the development of problem-solving skills it is important for researchers and curriculum developers to have practical tools that can measure the difference between novice and expert problem-solving performance in authentic classroom work. It is also useful if such tools can be employed by instructors to guide their pedagogy. We describe the design, development, and testing of a simple rubric to assess written solutions to problems given in undergraduate introductory physics courses. In particular, we present evidence for the validity, reliability, and utility of the instrument. The rubric identifies five general problem-solving processes and defines the criteria to attain a score in each: organizing problem information into a Useful Description, selecting appropriate principles (Physics Approach), applying those principles to the specific conditions in the problem (Specific Application of Physics), using Mathematical Procedures appropriately, and displaying evidence of an organized reasoning pattern (Logical Progression).

  16. Accelerating Innovation: How Nuclear Physics Benefits Us All

    SciTech Connect

    Not Available

    2011-01-01

    From fighting cancer to assuring food is safe to protecting our borders, nuclear physics impacts the lives of people around the globe every day. In learning about the nucleus of the atom and the forces that govern it, scientists develop a depth of knowledge, techniques and remarkable research tools that can be used to develop a variety of often unexpected, practical applications. These applications include devices and technologies for medical diagnostics and therapy, energy production and exploration, safety and national security, and for the analysis of materials and environmental contaminants. This brochure by the Office of Nuclear Physics of the USDOE Office of Science discusses nuclear physics and ways in which its applications fuel our economic vitality, and make the world and our lives safer and healthier.

  17. Physical analysis of the radiation shielding for the medical accelerators

    NASA Astrophysics Data System (ADS)

    Li, Q. F.; Xing, Q. Z.; Kong, C. C.

    2009-02-01

    Radiation safety standards today require comprehensive shielding protection schemes for all particle accelerators. The original shielding system of BJ-20 (BeiJing-20 MeV), the high-energy medical electron linac, was designed only for the 18 MeV level. And the dose caused by the lost electrons in the 270° bending magnet system was neglected. In this paper, the leakage dose of BJ-20 is carefully analyzed. The radiation leakage dose distribution of the photons coming from the accelerator head is obtained for energy levels of 6, 12, 14, and 18 MeV. The dose of the photoneutrons is especially analyzed for the 18 MeV level. The result gives that even neglecting the dose from the 270° bending magnet system, the shielding system is still not enough for the energy levels lower than 18 MeV. The radiation leakage produced by electrons that are lost in the 270° bending magnet system has been particularly studied. Using beam transport theory and Monte Carlo sampling methods, which have been combined in calculations, we have obtained the distribution of the energy, position, and direction of the lost electrons. These data were then further processed by the Monte Carlo N-particle (MCNP) code as input data. The results show that when the electron loss rate in the 270° bending magnet system is 13.5%, the radiation leakage dose of the photons generated by the lost electrons is 0.1% higher than that at the isocenter, and the corresponding relative leakage dose of the photoneutrons reaches 0.045% around an angle of 170° at 18 MeV level. Both of these parameters exceed radioprotection safety standards for medical accelerators. The original shielding design is therefore not suitable and is also incomplete since the radiation produced by the electrons being lost in the 270° bending magnet system was neglected and the leakage dose for the low-energy levels was not considered in the original design. Our calculations provide a very useful tool for further optimization and design

  18. System modeling for the longitudinal beam dynamics control problem in heavy ion induction accelerators

    SciTech Connect

    Payne, A.N.

    1993-05-17

    We address the problem of developing system models that are suitable for studying the control of the longitudinal beam dynamics in induction accelerators for heavy ions. In particular, we present the preliminary results of our efforts to devise a general framework for building detailed, integrated models of accelerator systems consisting of pulsed power modular circuits, induction cells, beam dynamics, and control system elements. Such a framework will permit us to analyze and design the pulsed power modulators and the control systems required to effect precise control over the longitudinal beam dynamics.

  19. Computer Based Collaborative Problem Solving for Introductory Courses in Physics

    NASA Astrophysics Data System (ADS)

    Ilie, Carolina; Lee, Kevin

    2010-03-01

    We discuss collaborative problem solving computer-based recitation style. The course is designed by Lee [1], and the idea was proposed before by Christian, Belloni and Titus [2,3]. The students find the problems on a web-page containing simulations (physlets) and they write the solutions on an accompanying worksheet after discussing it with a classmate. Physlets have the advantage of being much more like real-world problems than textbook problems. We also compare two protocols for web-based instruction using simulations in an introductory physics class [1]. The inquiry protocol allowed students to control input parameters while the worked example protocol did not. We will discuss which of the two methods is more efficient in relation to Scientific Discovery Learning and Cognitive Load Theory. 1. Lee, Kevin M., Nicoll, Gayle and Brooks, Dave W. (2004). ``A Comparison of Inquiry and Worked Example Web-Based Instruction Using Physlets'', Journal of Science Education and Technology 13, No. 1: 81-88. 2. Christian, W., and Belloni, M. (2001). Physlets: Teaching Physics With Interactive Curricular Material, Prentice Hall, Englewood Cliffs, NJ. 3. Christian,W., and Titus,A. (1998). ``Developing web-based curricula using Java Physlets.'' Computers in Physics 12: 227--232.

  20. The physics design of accelerator-driven transmutation systems

    SciTech Connect

    Venneri, F.

    1995-02-01

    Nuclear systems under study in the Los Alamos Accelerator-Driven Transmutation Technology program (ADTT) will allow the destruction of nuclear spent fuel and weapons-return plutonium, as well as the production of nuclear energy from the thorium cycle, without a long-lived radioactive waste stream. The subcritical systems proposed represent a radical departure from traditional nuclear concepts (reactors), yet the actual implementation of ADTT systems is based on modest extrapolations of existing technology. These systems strive to keep the best that the nuclear technology has developed over the years, within a sensible conservative design envelope and eventually manage to offer a safer, less expensive and more environmentally sound approach to nuclear power.

  1. Expert and novice categorization of introductory physics problems

    NASA Astrophysics Data System (ADS)

    Wolf, Steven Frederick

    Since it was first published 30 years ago, Chi et al.'s seminal paper on expert and novice categorization of introductory problems led to a plethora of follow-up studies within and outside of the area of physics [Chi et al. Cognitive Science 5, 121 -- 152 (1981)]. These studies frequently encompass "card-sorting" exercises whereby the participants group problems. The study firmly established the paradigm that novices categorize physics problems by "surface features" (e.g. "incline," "pendulum," "projectile motion,"... ), while experts use "deep structure" (e.g. "energy conservation," "Newton 2,"... ). While this technique certainly allows insights into problem solving approaches, simple descriptive statistics more often than not fail to find significant differences between experts and novices. In most experiments, the clean-cut outcome of the original study cannot be reproduced. Given the widespread implications of the original study, the frequent failure to reproduce its findings warrants a closer look. We developed a less subjective statistical analysis method for the card sorting outcome and studied how the "successful" outcome of the experiment depends on the choice of the original card set. Thus, in a first step, we are moving beyond descriptive statistics, and develop a novel microscopic approach that takes into account the individual identity of the cards and uses graph theory and models to visualize, analyze, and interpret problem categorization experiments. These graphs are compared macroscopically, using standard graph theoretic statistics, and microscopically, using a distance metric that we have developed. This macroscopic sorting behavior is described using our Cognitive Categorization Model. The microscopic comparison allows us to visualize our sorters using Principal Components Analysis and compare the expert sorters to the novice sorters as a group. In the second step, we ask the question: Which properties of problems are most important in problem

  2. Proceedings of the workshop on B physics at hadron accelerators

    SciTech Connect

    McBride, P.; Mishra, C.S.

    1993-12-31

    This report contains papers on the following topics: Measurement of Angle {alpha}; Measurement of Angle {beta}; Measurement of Angle {gamma}; Other B Physics; Theory of Heavy Flavors; Charged Particle Tracking and Vertexing; e and {gamma} Detection; Muon Detection; Hadron ID; Electronics, DAQ, and Computing; and Machine Detector Interface. Selected papers have been indexed separately for inclusion the in Energy Science and Technology Database.

  3. Problems with the rush toward advanced physics in high schools

    NASA Astrophysics Data System (ADS)

    Gollub, Jerry

    2003-04-01

    The Advanced Placement (AP) Program has a major impact on the physics experience of many high school students. It affects admission to college, course choices and performance in college, and subsequent career decisions. A study committee of the National Research Council published a review of these programs in 2002, and concluded that while the program has many positive features, important problems need to be addressed. [1] The programs are not currently consistent with what we have learned about student learning from cognitive research. Students are often poorly prepared for AP courses, because of lack of coordination within schools. The Physics AP-B (non-calculus) program is too broad to allow most high school students to achieve an adequate level of conceptual understanding. Participation by minority students in these programs is far below that of other students. The AP exams need to be re-evaluated to insure that they actually measure conceptual understanding and complex reasoning. The AP exams are sometimes used inappropriately to rate teachers or schools. College and high school courses are poorly coordinated, with the result that students often take an introductory physics survey as many as three times. Policies on college credit for AP courses differ widely. These problems cannot be fixed by the College Board alone. [1] Jerry P. Gollub and Robin Spital, "Advanced Physics in the High Schools", Physics Today, May 2002.

  4. Implementation of an Accelerated Physical Examination Course in a Doctor of Pharmacy Program

    PubMed Central

    Ho, Jackie; Lopes, Ingrid C.; Shah, Bijal M.; Ip, Eric J.

    2014-01-01

    Objective. To describe the implementation of a 1-day accelerated physical examination course for a doctor of pharmacy program and to evaluate pharmacy students’ knowledge, attitudes, and confidence in performing physical examination. Design. Using a flipped teaching approach, course coordinators collaborated with a physician faculty member to design and develop the objectives of the course. Knowledge, attitude, and confidence survey questions were administered before and after the practical laboratory. Assessment. Following the practical laboratory, knowledge improved by 8.3% (p<0.0001). Students’ perceived ability and confidence to perform a physical examination significantly improved (p<0.0001). A majority of students responded that reviewing the training video (81.3%) and reading material (67.4%) prior to the practical laboratory was helpful in learning the physical examination. Conclusion. An accelerated physical examination course using a flipped teaching approach was successful in improving students’ knowledge of, attitudes about, and confidence in using physical examination skills in pharmacy practice. PMID:25657369

  5. Facilitating students' application of the integral and the area under the curve concepts in physics problems

    NASA Astrophysics Data System (ADS)

    Nguyen, Dong-Hai

    This research project investigates the difficulties students encounter when solving physics problems involving the integral and the area under the curve concepts and the strategies to facilitate students learning to solve those types of problems. The research contexts of this project are calculus-based physics courses covering mechanics and electromagnetism. In phase I of the project, individual teaching/learning interviews were conducted with 20 students in mechanics and 15 students from the same cohort in electromagnetism. The students were asked to solve problems on several topics of mechanics and electromagnetism. These problems involved calculating physical quantities (e.g. velocity, acceleration, work, electric field, electric resistance, electric current) by integrating or finding the area under the curve of functions of related quantities (e.g. position, velocity, force, charge density, resistivity, current density). Verbal hints were provided when students made an error or were unable to proceed. A total number of 140 one-hour interviews were conducted in this phase, which provided insights into students' difficulties when solving the problems involving the integral and the area under the curve concepts and the hints to help students overcome those difficulties. In phase II of the project, tutorials were created to facilitate students' learning to solve physics problems involving the integral and the area under the curve concepts. Each tutorial consisted of a set of exercises and a protocol that incorporated the helpful hints to target the difficulties that students expressed in phase I of the project. Focus group learning interviews were conducted to test the effectiveness of the tutorials in comparison with standard learning materials (i.e. textbook problems and solutions). Overall results indicated that students learning with our tutorials outperformed students learning with standard materials in applying the integral and the area under the curve

  6. Toward the automated analysis of plasma physics problems

    SciTech Connect

    Mynick, H.E.

    1989-04-01

    A program (CALC) is described, which carries out nontrivial plasma physics calculations, in a manner intended to emulate the approach of a human theorist. This includes the initial process of gathering the relevant equations from a plasma knowledge base, and then determining how to solve them. Solution of the sets of equations governing physics problems, which in general have a nonuniform,irregular structure, not amenable to solution by standardized algorithmic procedures, is facilitated by an analysis of the structure of the equations and the relations among them. This often permits decompositions of the full problem into subproblems, and other simplifications in form, which renders the resultant subsystems soluble by more standardized tools. CALC's operation is illustrated by a detailed description of its treatment of a sample plasma calculation. 5 refs., 3 figs.

  7. High energy physics advisory panel`s composite subpanel for the assessment of the status of accelerator physics and technology

    SciTech Connect

    1996-05-01

    In November 1994, Dr. Martha Krebs, Director of the US Department of Energy (DOE) Office of Energy Research (OER), initiated a broad assessment of the current status and promise of the field of accelerator physics and technology with respect to five OER programs -- High Energy Physics, Nuclear Physics, Basic Energy Sciences, Fusion Energy, and Health and Environmental Research. Dr. Krebs asked the High Energy Physics Advisory Panel (HEPAP) to establish a composite subpanel with representation from the five OER advisory committees and with a balance of membership drawn broadly from both the accelerator community and from those scientific disciplines associated with the OER programs. The Subpanel was also charged to provide recommendations and guidance on appropriate future research and development needs, management issues, and funding requirements. The Subpanel finds that accelerator science and technology is a vital and intellectually exciting field. It has provided essential capabilities for the DOE/OER research programs with an enormous impact on the nation`s scientific research, and it has significantly enhanced the nation`s biomedical and industrial capabilities. Further progress in this field promises to open new possibilities for the scientific goals of the OER programs and to further benefit the nation. Sustained support of forefront accelerator research and development by the DOE`s OER programs and the DOE`s predecessor agencies has been responsible for much of this impact on research. This report documents these contributions to the DOE energy research mission and to the nation.

  8. Report of the Subpanel on Accelerator Research and Development of the High Energy Physics Advisory Panel

    SciTech Connect

    Not Available

    1980-06-01

    Accelerator R and D in the US High Energy Physics (HEP) program is reviewed. As a result of this study, some shift in priority, particularly as regards long-range accelerator R and D, is suggested to best serve the future needs of the US HEP program. Some specific new directions for the US R and D effort are set forth. 18 figures, 5 tables. (RWR)

  9. Grey transport acceleration method for time-dependent radiative transfer problems

    SciTech Connect

    Larsen, E.

    1988-10-01

    A new iterative method for solving hte time-dependent multifrequency radiative transfer equations is described. The method is applicable to semi-implicit time discretizations that generate a linear steady-state multifrequency transport problem with pseudo-scattering within each time step. The standard ''lambda'' iteration method is shown to often converge slowly for such problems, and the new grey transport acceleration (GTA) method, based on accelerating the lambda method by employing a grey, or frequency-independent transport equation, is developed. The GTA method is shown, theoretically by an iterative Fourier analysis, and experimentally by numerical calculations, to converge significantly faster than the lambda method. In addition, the GTA method is conceptually simple to implement for general differencing schemes, on either Eulerian or Lagrangian meshes. copyright 1988 Academic Press, Inc.

  10. High order methods for elliptic problems in plasma physics

    NASA Astrophysics Data System (ADS)

    Pataki, Andras

    In this dissertation, we develop fast high order solvers for two elliptic problems in plasma physics. The first is the Grad-Shafranov equation, a nonlinear elliptic PDE that describes the magnetohydrodynamic equilibrium of three dimensional, axisymmetric plasmas. A high order solver is desirable to ensure the accurate evaluation of derivatives, required both for the computation of physical quantities and for studying perturbations near equilibrium. Using suitable scaling, we transform the problem from cylindrical coordinates to a nonlinear Poisson problem in Cartesian coordinates. We compute the conformal map from the original domain to the unit circle where we build a separation of variables based solver to obtain a high order, accurate solution. A fixed point or eigenvalue outer iteration is used to solve the nonlinear equation. Our second problem is the computation of the Coulomb collision operator that arises in kinetic models of plasmas. The collision operator can be written in terms of two Rosenbluth potentials obtained by solving a Poisson and a biharmonic problem in the velocity variables. For these PDEs we describe a new class of fast solvers in cylindrical coordinates with free-space radiation conditions. By combining integral equation methods in the radial variable with Fourier methods in the angular and z directions, we show that high-order accuracy can be achieved in both the solution and its derivatives. A weak singularity arises in the Fourier transform with respect to z that is handled with special purpose quadratures. Such solvers are ideally suited to the Rosenbluth potentials, since the collision operator is expressed in terms of up to fourth derivatives of the potentials, placing stringent demands on the computational order. Also, since axisymmetry is generally assumed in the velocity variables, the use of cylindrical coordinates reduces the three dimensional problem to a two dimensional computation.

  11. Some problems of pulsar physics. [magnetospheric plasma model

    NASA Technical Reports Server (NTRS)

    Arons, J.

    1979-01-01

    The theories of particle acceleration along polar field lines are reviewed, and the total energization of the charge separated plasma is summarized, when pair creation is absent. The application of these theories and plasma supply to pulsars is discussed, with attention given to the total amount of electron-positron plasma created and its momentum distribution. Various aspects of radiation emission and transport are analyzed, based on a polar current flow model with pair creation, and the phenomenon of marching subpulses is considered. The coronation beaming and the relativistically expanding current sheet models for pulsar emission are also outlined, and the paper concludes with a brief discussion of the relation between the theories of polar flow with pair plasma and the problem of the energization of the Crab Nebula.

  12. Physical and mechanical metallurgy of high purity Nb accelerator cavities.

    SciTech Connect

    Wright, N. T.; Bieler, T. R.; Pourgoghart , F.; Compton, C.; Hartwig, K. T.; Baars, D.; Zamiri, A.; Chandrasekaran, S.; Darbandi, P.; Jiang, H.; Skoug, E.; Balachandran, S.; Ice, G. E.; Liu, W.; Michigan State Univ.; Texas A & M Univ.; ORNL

    2010-01-01

    In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

  13. Physical activity problem-solving inventory for adolescents: Development and initial validation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Youth encounter physical activity barriers, often called problems. The purpose of problem-solving is to generate solutions to overcome the barriers. Enhancing problem-solving ability may enable youth to be more physically active. Therefore, a method for reliably assessing physical activity problem-s...

  14. Accelerated projected steepest descent method for nonlinear inverse problems with sparsity constraints

    NASA Astrophysics Data System (ADS)

    Teschke, Gerd; Borries, Claudia

    2010-02-01

    This paper is concerned with the construction of an iterative algorithm to solve nonlinear inverse problems with an ell1 constraint on x. One extensively studied method to obtain a solution of such an ell1 penalized problem is iterative soft-thresholding. Regrettably, such iteration schemes are computationally very intensive. A subtle alternative to iterative soft-thresholding is the projected gradient method that was quite recently proposed by Daubechies et al (2008 J. Fourier Anal. Appl. 14 764-92). The authors have shown that the proposed scheme is indeed numerically much thriftier. However, its current applicability is limited to linear inverse problems. In this paper we provide an extension of this approach to nonlinear problems. Adequately adapting the conditions on the (variable) thresholding parameter to the nonlinear nature, we can prove convergence in norm for this projected gradient method, with and without acceleration. A numerical verification is given in the context of nonlinear and non-ideal sensing. For this particular recovery problem we can achieve an impressive numerical performance (when comparing it to non-accelerated procedures).

  15. Mount Aragats as a stable electron accelerator for atmospheric high-energy physics research

    NASA Astrophysics Data System (ADS)

    Chilingarian, Ashot; Hovsepyan, Gagik; Mnatsakanyan, Eduard

    2016-03-01

    Observation of the numerous thunderstorm ground enhancements (TGEs), i.e., enhanced fluxes of electrons, gamma rays, and neutrons detected by particle detectors located on the Earth's surface and related to the strong thunderstorms above it, helped to establish a new scientific topic—high-energy physics in the atmosphere. Relativistic runaway electron avalanches (RREAs) are believed to be a central engine initiating high-energy processes in thunderstorm atmospheres. RREAs observed on Mount Aragats in Armenia during the strongest thunderstorms and simultaneous measurements of TGE electron and gamma-ray energy spectra proved that RREAs are a robust and realistic mechanism for electron acceleration. TGE research facilitates investigations of the long-standing lightning initiation problem. For the last 5 years we were experimenting with the "beams" of "electron accelerators" operating in the thunderclouds above the Aragats research station. Thunderstorms are very frequent above Aragats, peaking in May-June, and almost all of them are accompanied with enhanced particle fluxes. The station is located on a plateau at an altitude 3200 asl near a large lake. Numerous particle detectors and field meters are located in three experimental halls as well as outdoors; the facilities are operated all year round. All relevant information is being gathered, including data on particle fluxes, fields, lightning occurrences, and meteorological conditions. By the example of the huge thunderstorm that took place at Mount Aragats on August 28, 2015, we show that simultaneous detection of all the relevant data allowed us to reveal the temporal pattern of the storm development and to investigate the atmospheric discharges and particle fluxes.

  16. Deep ocean mineral water accelerates recovery from physical fatigue

    PubMed Central

    2013-01-01

    Background Deep oceans have been suggested as a possible site where the origin of life occurred. Along with this theoretical lineage, experiments using components from deep ocean water to recreate life is underway. Here, we propose that if terrestrial organisms indeed evolved from deep oceans, supply of deep ocean mineral water (DOM) to humans, as a land creature, may replenish loss of molecular complexity associated with evolutionary sea-to-land migration. Methods We conducted a randomized, double-blind, placebo-controlled crossover human study to evaluate the effect of DOM, taken from a depth of 662 meters off the coast of Hualien, Taiwan, on time of recovery from a fatiguing exercise conducted at 30°C. Results The fatiguing exercise protocol caused a protracted reduction in aerobic power (reduced VO2max) for 48 h. However, DOM supplementation resulted in complete recovery of aerobic power within 4 h (P < 0.05). Muscle power was also elevated above placebo levels within 24 h of recovery (P < 0.05). Increased circulating creatine kinase (CK) and myoglobin, indicatives of exercise-induced muscle damage, were completely eliminated by DOM (P < 0.05) in parallel with attenuated oxidative damage (P < 0.05). Conclusion Our results provide compelling evidence that DOM contains soluble elements, which can increase human recovery following an exhaustive physical challenge. PMID:23402436

  17. Earth's magnetosphere - Global problems in magnetospheric plasma physics

    NASA Technical Reports Server (NTRS)

    Roederer, J. G.

    1979-01-01

    Magnetospheric physics is presently in a transition from the exploratory stage to one in which satellite missions and ground-based observations are planned with the specific object of achieving a global understanding and self-consistent quantitative description of the cause-and-effect relationship among the principal dynamic processes involved. Measurements turn to lower and lower energies and to higher ion mass species, in order to encompass the entire particle population, and to a broader range of the frequency spectrum of magnetic and electric field variations. In the present paper, the current status of our knowledge on magnetospheric plasma physics is reviewed, with particular reference of such fundamental advances as the discovery of layers of streaming plasma in the magnetosphere beneath its boundary surface, the identification of the terrestrial magnetosphere as a celestial source of kilometric radiation and relativistic particles, the identification of parallel electric field regions within the magnetosphere and their role in auroral particle acceleration, and the discovery of large fluxes of energetic heavy ions trapped in the magnetosphere.

  18. Theoretical Problems in High Resolution Solar Physics, 2

    NASA Technical Reports Server (NTRS)

    Athay, G. (Editor); Spicer, D. S. (Editor)

    1987-01-01

    The Science Working Group for the High Resolution Solar Observatory (HRSO) laid plans beginning in 1984 for a series of workshops designed to stimulate a broadbased input from the scientific community to the HRSO mission. These workshops have the dual objectives of encouraging an early start on the difficult theoretical problems in radiative transfer, magnetohydrodynamics, and plasma physics that will be posed by the HRSO data, and maintaining current discussions of results in high resolution solar studies. This workshop was the second in the series. The workshop format presented invited review papers during the formal sessions and contributed poster papers for discussions during open periods. Both are presented.

  19. Exercises are problems too: implications for teaching problem-solving in introductory physics courses

    NASA Astrophysics Data System (ADS)

    Zuza, Kristina; Garmendia, Mikel; Barragués, José-Ignacio; Guisasola, Jenaro

    2016-09-01

    Frequently, in university-level general physics courses, after explaining the theory, exercises are set based on examples that illustrate the application of concepts and laws. Traditionally formulated numerical exercises are usually solved by the teacher and students through direct replacement of data in formulae. It is our contention that such strategies can lead to the superficial and erroneous resolution of such exercises. In this paper, we provide an example that illustrates that students tend to solve problems in a superficial manner, without applying fundamental problem-solving strategies such as qualitative analysis, hypothesis-forming and analysis of results, which prevents them from arriving at a correct solution. We provide evidence of the complexity of an a priori simple exercise in physics, although the theory involved may seem elementary at first sight. Our aim is to stimulate reflection among instructors to follow these results when using examples and solving exercises with students.

  20. Pyroelectric Crystal Accelerator In The Department Of Physics And Nuclear Engineering At West Point

    NASA Astrophysics Data System (ADS)

    Gillich, Don; Shannon, Mike; Kovanen, Andrew; Anderson, Tom; Bright, Kevin; Edwards, Ronald; Danon, Yaron; Moretti, Brian; Musk, Jeffrey

    2011-06-01

    The Nuclear Science and Engineering Research Center (NSERC), a Defense Threat Reduction Agency (DTRA) office located at the United States Military Academy (USMA), sponsors and manages cadet and faculty research in support of DTRA objectives. The NSERC has created an experimental pyroelectric crystal accelerator program to enhance undergraduate education at USMA in the Department of Physics and Nuclear Engineering. This program provides cadets with hands-on experience in designing their own experiments using an inexpensive tabletop accelerator. This device uses pyroelectric crystals to ionize and accelerate gas ions to energies of ˜100 keV. Within the next year, cadets and faculty at USMA will use this device to create neutrons through the deuterium-deuterium (D-D) fusion process, effectively creating a compact, portable neutron generator. The double crystal pyroelectric accelerator will also be used by students to investigate neutron, x-ray, and ion spectroscopy.

  1. Solving Large Scale Nonlinear Eigenvalue Problem in Next-Generation Accelerator Design

    SciTech Connect

    Liao, Ben-Shan; Bai, Zhaojun; Lee, Lie-Quan; Ko, Kwok; /SLAC

    2006-09-28

    A number of numerical methods, including inverse iteration, method of successive linear problem and nonlinear Arnoldi algorithm, are studied in this paper to solve a large scale nonlinear eigenvalue problem arising from finite element analysis of resonant frequencies and external Q{sub e} values of a waveguide loaded cavity in the next-generation accelerator design. They present a nonlinear Rayleigh-Ritz iterative projection algorithm, NRRIT in short and demonstrate that it is the most promising approach for a model scale cavity design. The NRRIT algorithm is an extension of the nonlinear Arnoldi algorithm due to Voss. Computational challenges of solving such a nonlinear eigenvalue problem for a full scale cavity design are outlined.

  2. Assessing Student Expertise in Introductory Physics with Isomorphic Problems. II. Effect of Some Potential Factors on Problem Solving and Transfer

    ERIC Educational Resources Information Center

    Chandralekha; Singh

    2008-01-01

    In this paper, we explore the use of isomorphic problem pairs (IPPs) to assess introductory physics students' ability to solve and successfully transfer problem-solving knowledge from one context to another in mechanics. We call the paired problems "isomorphic" because they require the same physics principle to solve them. We analyze written…

  3. Dark energy in modified Gauss-Bonnet gravity: Late-time acceleration and the hierarchy problem

    SciTech Connect

    Cognola, Guido; Zerbini, Sergio; Elizalde, Emilio; Nojiri, Shin'ichi; Odintsov, Sergei D.

    2006-04-15

    Dark energy cosmology is considered in a modified Gauss-Bonnet (GB) model of gravity where an arbitrary function of the GB invariant, f(G), is added to the general relativity action. We show that a theory of this kind is endowed with a quite rich cosmological structure: it may naturally lead to an effective cosmological constant, quintessence, or phantom cosmic acceleration, with a possibility for the transition from deceleration to acceleration. It is demonstrated in the paper that this theory is perfectly viable, since it is compliant with the solar system constraints. Specific properties of f(G) gravity in a de Sitter (dS) universe, such as dS and SdS solutions, their entropy, and its explicit one-loop quantization are studied. The issue of a possible solution of the hierarchy problem in modified gravities is also addressed.

  4. Using a mobile phone acceleration sensor in physics experiments on free and damped harmonic oscillations

    NASA Astrophysics Data System (ADS)

    Carlos Castro-Palacio, Juan; Velázquez-Abad, Luisberis; Giménez, Marcos H.; Monsoriu, Juan A.

    2013-06-01

    We have used a mobile phone acceleration sensor, and the Accelerometer Monitor application for Android, to collect data in physics experiments on free and damped oscillations. Results for the period, frequency, spring constant, and damping constant agree very well with measurements obtained by other methods. These widely available sensors are likely to find increased use in instructional laboratories.

  5. Surveying Turkish High School and University Students' Attitudes and Approaches to Physics Problem Solving

    ERIC Educational Resources Information Center

    Balta, Nuri; Mason, Andrew J.; Singh, Chandralekha

    2016-01-01

    Students' attitudes and approaches to physics problem solving can impact how well they learn physics and how successful they are in solving physics problems. Prior research in the U.S. using a validated Attitude and Approaches to Problem Solving (AAPS) survey suggests that there are major differences between students in introductory physics and…

  6. Physical Interpretation of the Schott Energy of An Accelerating Point Charge and the Question of Whether a Uniformly Accelerating Charge Radiates

    ERIC Educational Resources Information Center

    Rowland, David R.

    2010-01-01

    A core topic in graduate courses in electrodynamics is the description of radiation from an accelerated charge and the associated radiation reaction. However, contemporary papers still express a diversity of views on the question of whether or not a uniformly accelerating charge radiates suggesting that a complete "physical" understanding of the…

  7. Computations and algorithms in physical and biological problems

    NASA Astrophysics Data System (ADS)

    Qin, Yu

    This dissertation presents the applications of state-of-the-art computation techniques and data analysis algorithms in three physical and biological problems: assembling DNA pieces, optimizing self-assembly yield, and identifying correlations from large multivariate datasets. In the first topic, in-depth analysis of using Sequencing by Hybridization (SBH) to reconstruct target DNA sequences shows that a modified reconstruction algorithm can overcome the theoretical boundary without the need for different types of biochemical assays and is robust to error. In the second topic, consistent with theoretical predictions, simulations using Graphics Processing Unit (GPU) demonstrate how controlling the short-ranged interactions between particles and controlling the concentrations optimize the self-assembly yield of a desired structure, and nonequilibrium behavior when optimizing concentrations is also unveiled by leveraging the computation capacity of GPUs. In the last topic, a methodology to incorporate existing categorization information into the search process to efficiently reconstruct the optimal true correlation matrix for multivariate datasets is introduced. Simulations on both synthetic and real financial datasets show that the algorithm is able to detect signals below the Random Matrix Theory (RMT) threshold. These three problems are representatives of using massive computation techniques and data analysis algorithms to tackle optimization problems, and outperform theoretical boundary when incorporating prior information into the computation.

  8. Accelerator physics and technology challenges of very high energy hadron colliders

    DOE PAGESBeta

    Shiltsev, Vladimir D.

    2015-08-20

    High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton–proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This article briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

  9. Accelerator physics and technology challenges of very high energy hadron colliders

    NASA Astrophysics Data System (ADS)

    Shiltsev, Vladimir D.

    2015-08-01

    High energy hadron colliders have been in the forefront of particle physics for more than three decades. At present, international particle physics community considers several options for a 100 TeV proton-proton collider as a possible post-LHC energy frontier facility. The method of colliding beams has not fully exhausted its potential but has slowed down considerably in its progress. This paper briefly reviews the accelerator physics and technology challenges of the future very high energy colliders and outlines the areas of required research and development towards their technical and financial feasibility.

  10. The Science Shop for Physics: an interface between practical problems in society and physical knowledge

    NASA Astrophysics Data System (ADS)

    van den Berg, G. P.

    1998-03-01

    Since some 20 years most Dutch universities have one or more science shops. Central shops handle research questions for all disciplines. Specialized shops are part of a department of chemistry or medicine, history, social science, etc. The shops have evolved rather differently, but their main mission still is to help social groups that lack money and have no easy access to scientific knowledge, e.g. neighbourhood, environmental, third world or patient groups. Most also help non-commercial organizations such as schools, trade unions or local authorities. Low-cost help can be provided because students do the work as part of their training, mainly in student projects (literature search, practical work, graduation, etc.). A total staff of 80, helped by 600 students, 250 voluntary and 50 paid researchers, handle 1500 questions resulting in 300 reports (estimated figures 1995). Science shops for physics (`Physics Shop', PS) have to deal with practical problems, generally involving classical physics. Major topics are noise, vibration, radiation, indoor climate and energy: most of the work lies in estimating/measuring relevant parameters, assessing impact, seeking solutions. The 3 Dutch PS's have developed in different directions. One is run entirely by students and deals with small, concrete problems. The second PS is managed by a co-ordinator who mediates between client groups and physics staff members who assist students in small and larger projects. The third has a lot of in-house expertise, and the shop staff is in direct contact with client groups as well as students who work in the PS itself. In questions submitted to the PS it is not always immediately clear what to do or how to do it because of the non-scientific phrasing of the problems and problems include non-physical (e.g. technical, health or legal) aspects. Also, difficulties in solving the problems are typically not in the underlying physics, but in the lack of accurate data and of control of the complex

  11. Physics students' approaches to learning and cognitive processes in solving physics problems

    NASA Astrophysics Data System (ADS)

    Bouchard, Josee

    This study examined traditional instruction and problem-based learning (PBL) approaches to teaching and the extent to which they foster the development of desirable cognitive processes, including metacognition, critical thinking, physical intuition, and problem solving among undergraduate physics students. The study also examined students' approaches to learning and their perceived role as physics students. The research took place in the context of advanced courses of electromagnetism at a Canadian research university. The cognitive science, expertise, physics and science education, instructional psychology, and discourse processes literature provided the framework and background to conceptualize and structure this study. A within-stage mixed-model design was used and a number of instruments, including a survey, observation grids, and problem sets were developed specifically for this study. A special one-week long problem-based learning (PBL) intervention was also designed. Interviews with the instructors participating in the study provided complementary data. Findings include evidence that students in general engage in metacognitive processes in the organization of their personal study time. However, this potential, including the development of other cognitive processes, might not be stimulated as much as it could in the traditional lecture instructional context. The PBL approach was deemed as more empowering for the students. An unexpected finding came from the realisation that a simple exposure to a structured exercise of problem-solving (pre-test) was sufficient to produce superior planning and solving strategies on a second exposure (post-test) even for the students who had not been exposed to any special treatment. Maturation was ruled out as a potential threat to the validity of this finding. Another promising finding appears to be that the problem-based learning (PBL) intervention tends to foster the development of cognitive competencies, particularly

  12. A precorrected-FFT method to accelerate the solution of the forward problem in magnetoencephalography

    NASA Astrophysics Data System (ADS)

    Tissari, Satu; Rahola, Jussi

    2003-02-01

    Accurate localization of brain activity recorded by magnetoencephalography (MEG) requires that the forward problem, i.e. the magnetic field caused by a dipolar source current in a homogeneous volume conductor, be solved precisely. We have used the Galerkin method with piecewise linear basis functions in the boundary element method to improve the solution of the forward problem. In addition, we have replaced the direct method, i.e. the LU decomposition, by a modern iterative method to solve the dense linear system of equations arising from the boundary element discretization. In this paper we describe a precorrected-FFT method which we have combined with the iterative method to accelerate the solution of the forward problem and to avoid the explicit formation of the dense coefficient matrix. For example, with a triangular mesh of 18000 triangles, the CPU time to solve the forward problem was decreased from 3.5 h to less than 5 min, and the computer memory requirements were decreased from 1.3 GB to 156 MB. The method makes it possible to solve quickly significantly larger problems with widely-used workstations.

  13. Induction-accelerator heavy-ion fusion: Status and beam physics issues

    SciTech Connect

    Friedman, A.

    1996-01-26

    Inertial confinement fusion driven by beams of heavy ions is an attractive route to controlled fusion. In the U.S., induction accelerators are being developed as {open_quotes}drivers{close_quotes} for this process. This paper is divided into two main sections. In the first section, the concept of induction-accelerator driven heavy-ion fusion is briefly reviewed, and the U.S. program of experiments and theoretical investigations is described. In the second, a {open_quotes}taxonomy{close_quotes} of space-charge-dominated beam physics issues is presented, accompanied by a brief discussion of each area.

  14. Physical Activities Monitoring Using Wearable Acceleration Sensors Attached to the Body

    PubMed Central

    2015-01-01

    Monitoring physical activities by using wireless sensors is helpful for identifying postural orientation and movements in the real-life environment. A simple and robust method based on time domain features to identify the physical activities is proposed in this paper; it uses sensors placed on the subjects’ wrist, chest and ankle. A feature set based on time domain characteristics of the acceleration signal recorded by acceleration sensors is proposed for the classification of twelve physical activities. Nine subjects performed twelve different types of physical activities, including sitting, standing, walking, running, cycling, Nordic walking, ascending stairs, descending stairs, vacuum cleaning, ironing clothes and jumping rope, and lying down (resting state). Their ages were 27.2 ± 3.3 years and their body mass index (BMI) is 25.11 ± 2.6 Kg/m2. Classification results demonstrated a high validity showing precision (a positive predictive value) and recall (sensitivity) of more than 95% for all physical activities. The overall classification accuracy for a combined feature set of three sensors is 98%. The proposed framework can be used to monitor the physical activities of a subject that can be very useful for the health professional to assess the physical activity of healthy individuals as well as patients. PMID:26203909

  15. Proceedings of the 2005 International Linear Collider Physics and Detector Workshop and 2nd ILC Accelerator Workshop (Snowmass 2005)

    SciTech Connect

    Graf, Norman A.

    2006-06-21

    For two weeks in August of 2005, 668 physicists gathered in the Rocky Mountains of Colorado to study the physics, the detectors and the accelerator of the International Linear Collider. For the first time, a fully international physics and detector workshop was held in conjunction with the ILC Accelerator workshop.

  16. Epistemic Beliefs about Justification Employed by Physics Students and Faculty in Two Different Problem Contexts

    ERIC Educational Resources Information Center

    Mercan, Fatih Caglayan

    2012-01-01

    This study examines the epistemic beliefs about justification employed by physics undergraduate and graduate students and faculty in the context of solving a standard classical physics problem and a frontier physics problem. Data were collected by a think-aloud problem solving session followed by a semi-structured interview conducted with 50…

  17. Instructors' Reasons for Choosing Problem Features in a Calculus-Based Introductory Physics Course

    ERIC Educational Resources Information Center

    Yerushalmi, Edit; Cohen, Elisheva; Heller, Kenneth; Heller, Patricia; Henderson, Charles

    2010-01-01

    This study investigates how the beliefs and values of physics faculty influence their choice of physics problems for their students in an introductory physics course. The study identifies the goals these instructors have for their students, the problem features they believe facilitate those goals, and how those features correspond to problems they…

  18. DEVELOPING THE PHYSICS DESIGN FOR NDCX-II, A UNIQUE PULSE-COMPRESSING ION ACCELERATOR

    SciTech Connect

    Friedman, A.; Barnard, J. J.; Cohen, R. H.; Grote, D. P.; Lund, S. M.; Sharp, W. M.; Faltens, A.; Henestroza, E.; Jung, J-Y.; Kwan, J. W.; Lee, E. P.; Leitner, M. A.; Logan, B. G.; Vay, J.-L.; Waldron, W. L.; Davidson, R.C.; Dorf, M.; Gilson, E.P.; Kaganovich, I.

    2009-07-20

    The Heavy Ion Fusion Science Virtual National Laboratory(a collaboration of LBNL, LLNL, and PPPL) is using intense ion beams to heat thin foils to the"warm dense matter" regime at<~;; 1 eV, and is developing capabilities for studying target physics relevant to ion-driven inertial fusion energy. The need for rapid target heating led to the development of plasma-neutralized pulse compression, with current amplification factors exceeding 50 now routine on the Neutralized Drift Compression Experiment (NDCX). Construction of an improved platform, NDCX-II, has begun at LBNL with planned completion in 2012. Using refurbished induction cells from the Advanced Test Accelerator at LLNL, NDCX-II will compress a ~;;500 ns pulse of Li+ ions to ~;;1 ns while accelerating it to 3-4 MeV over ~;;15 m. Strong space charge forces are incorporated into the machine design at a fundamental level. We are using analysis, an interactive 1D PIC code (ASP) with optimizing capabilities and centroid tracking, and multi-dimensional Warpcode PIC simulations, to develop the NDCX-II accelerator. This paper describes the computational models employed, and the resulting physics design for the accelerator.

  19. Developing The Physics Desing for NDCS-II, A Unique Pulse-Compressing Ion Accelerator

    SciTech Connect

    Friedman, A; Barnard, J J; Cohen, R H; Grote, D P; Lund, S M; Sharp, W M; Faltens, A; Henestroza, E; Jung, J; Kwan, J W; Lee, E P; Leitner, M A; Logan, B G; Vay, J -; Waldron, W L; Davidson, R C; Dorf, M; Gilson, E P; Kaganovich, I

    2009-09-24

    The Heavy Ion Fusion Science Virtual National Laboratory (a collaboration of LBNL, LLNL, and PPPL) is using intense ion beams to heat thin foils to the 'warm dense matter' regime at {approx}< 1 eV, and is developing capabilities for studying target physics relevant to ion-driven inertial fusion energy. The need for rapid target heating led to the development of plasma-neutralized pulse compression, with current amplification factors exceeding 50 now routine on the Neutralized Drift Compression Experiment (NDCX). Construction of an improved platform, NDCX-II, has begun at LBNL with planned completion in 2012. Using refurbished induction cells from the Advanced Test Accelerator at LLNL, NDCX-II will compress a {approx}500 ns pulse of Li{sup +} ions to {approx} 1 ns while accelerating it to 3-4 MeV over {approx} 15 m. Strong space charge forces are incorporated into the machine design at a fundamental level. We are using analysis, an interactive 1D PIC code (ASP) with optimizing capabilities and centroid tracking, and multi-dimensional Warpcode PIC simulations, to develop the NDCX-II accelerator. This paper describes the computational models employed, and the resulting physics design for the accelerator.

  20. Physical and Emotional Health Problems Experienced by Youth Engaged in Physical Fighting and Weapon Carrying

    PubMed Central

    Walsh, Sophie D.; Molcho, Michal; Craig, Wendy; Harel-Fisch, Yossi; Huynh, Quynh; Kukaswadia, Atif; Aasvee, Katrin; Várnai, Dora; Ottova, Veronika; Ravens-Sieberer, Ulrike; Pickett, William

    2013-01-01

    Then aims of the current study were 1) to provide cross-national estimates of the prevalence of physical fighting and weapon carrying among adolescents aged 11–15 years; (2) To examine the possible effects of physical fighting and weapon carrying on the occurrence of physical (medically treated injuries) and emotional health outcomes (multiple health complaints) among adolescents within the theoretical framework of Problem Behaviour Theory. 20,125 adolescents aged 11–15 in five countries (Belgium, Israel, USA, Canada, FYR Macedonia) were surveyed via the 2006 Health Behaviour in School Aged Children survey. Prevalence was calculated for physical fighting and weapon carrying along with physical and emotional measures that potentially result from violence. Regression analyses were used to quantify associations between violence/weapon carrying and the potential health consequences within each country. Large variations in fighting and weapon carrying were observed across countries. Boys reported more frequent episodes of fighting/weapon carrying and medically attended injuries in every country, while girls reported more emotional symptoms. Although there were some notable variations in findings between different participating countries, increased weapon carrying and physical fighting were both independently and consistently associated with more frequent reports of the potential health outcomes. Adolescents engaging in fighting and weapon carrying are also at risk for physical and emotional health outcomes. Involvement in fighting and weapon carrying can be seen as part of a constellation of risk behaviours with obvious health implications. Our findings also highlight the importance of the cultural context when examining the nature of violent behaviour for adolescents. PMID:23437126

  1. Physical activity recognition based on rotated acceleration data using quaternion in sedentary behavior: a preliminary study.

    PubMed

    Shin, Y E; Choi, W H; Shin, T M

    2014-01-01

    This paper suggests a physical activity assessment method based on quaternion. To reduce user inconvenience, we measured the activity using a mobile device which is not put on fixed position. Recognized results were verified with various machine learning algorithms, such as neural network (multilayer perceptron), decision tree (J48), SVM (support vector machine) and naive bayes classifier. All algorithms have shown over 97% accuracy including decision tree (J48), which recognized the activity with 98.35% accuracy. As a result, physical activity assessment method based on rotated acceleration using quaternion can classify sedentary behavior with more accuracy without considering devices' position and orientation. PMID:25571109

  2. Research on acceleration method of reactor physics based on FPGA platforms

    SciTech Connect

    Li, C.; Yu, G.; Wang, K.

    2013-07-01

    The physical designs of the new concept reactors which have complex structure, various materials and neutronic energy spectrum, have greatly improved the requirements to the calculation methods and the corresponding computing hardware. Along with the widely used parallel algorithm, heterogeneous platforms architecture has been introduced into numerical computations in reactor physics. Because of the natural parallel characteristics, the CPU-FPGA architecture is often used to accelerate numerical computation. This paper studies the application and features of this kind of heterogeneous platforms used in numerical calculation of reactor physics through practical examples. After the designed neutron diffusion module based on CPU-FPGA architecture achieves a 11.2 speed up factor, it is proved to be feasible to apply this kind of heterogeneous platform into reactor physics. (authors)

  3. Partitioned coupling strategies for multi-physically coupled radiative heat transfer problems

    NASA Astrophysics Data System (ADS)

    Wendt, Gunnar; Erbts, Patrick; Düster, Alexander

    2015-11-01

    This article aims to propose new aspects concerning a partitioned solution strategy for multi-physically coupled fields including the physics of thermal radiation. Particularly, we focus on the partitioned treatment of electro-thermo-mechanical problems with an additional fourth thermal radiation field. One of the main goals is to take advantage of the flexibility of the partitioned approach to enable combinations of different simulation software and solvers. Within the frame of this article, we limit ourselves to the case of nonlinear thermoelasticity at finite strains, using temperature-dependent material parameters. For the thermal radiation field, diffuse radiating surfaces and gray participating media are assumed. Moreover, we present a robust and fast partitioned coupling strategy for the fourth field problem. Stability and efficiency of the implicit coupling algorithm are improved drawing on several methods to stabilize and to accelerate the convergence. To conclude and to review the effectiveness and the advantages of the additional thermal radiation field several numerical examples are considered to study the proposed algorithm. In particular we focus on an industrial application, namely the electro-thermo-mechanical modeling of the field-assisted sintering technology.

  4. The cosmological 7Li problem from a nuclear physics perspective

    NASA Astrophysics Data System (ADS)

    Broggini, C.; Canton, L.; Fiorentini, G.; Villante, F. L.

    2012-06-01

    The primordial abundance of 7Li as predicted by Big Bang Nucleosynthesis (BBN) is more than a factor 2 larger than what has been observed in metal-poor halo stars. Herein, we analyze the possibility that this discrepancy originates from incorrect assumptions about the nuclear reaction cross sections relevant for BBN. To do this, we introduce an efficient method to calculate the changes in the 7Li abundance produced by arbitrary (temperature dependent) modifications of the nuclear reaction rates. Then, considering that 7Li is mainly produced from 7Be via the electron capture process 7Be+e- → 7Li+νe, we assess the impact of the various channels of 7Be destruction. Differently from previous analysis, we consider the role of unknown resonances by using a complete formalism which takes into account the effect of Coulomb and centrifugal barrier penetration and that does not rely on the use of the narrow-resonance approximation. As a result of this, the possibility of a nuclear physics solution to the 7Li problem is significantly suppressed. Given the present experimental and theoretical constraints, it is unlikely that the 7Be+n destruction rate is underestimated by the 2.5 factor required to solve the problem. We exclude, moreover, that resonant destruction in the channels 7Be+t and 7Be+3He can explain the 7Li puzzle. New unknown resonances in 7Be+d and 7Be+α could potentially produce significant effects. Recent experimental results have ruled out such a possibility for 7Be+d. On the other hand, for the 7Be+α channel very favorable conditions are required. The possible existence of a partially suitable resonant level in 11C is studied in the framework of a coupled-channel model and the possibility of a direct measurement is considered.

  5. The Krylov accelerated SIMPLE(R) method for flow problems in industrial furnaces

    NASA Astrophysics Data System (ADS)

    Vuik, C.; Saghir, A.; Boerstoel, G. P.

    2000-08-01

    Numerical modeling of the melting and combustion process is an important tool in gaining understanding of the physical and chemical phenomena that occur in a gas- or oil-fired glass-melting furnace. The incompressible Navier-Stokes equations are used to model the gas flow in the furnace. The discrete Navier-Stokes equations are solved by the SIMPLE(R) pressure-correction method. In these applications, many SIMPLE(R) iterations are necessary to obtain an accurate solution. In this paper, Krylov accelerated versions are proposed: GCR-SIMPLE(R). The properties of these methods are investigated for a simple two-dimensional flow. Thereafter, the efficiencies of the methods are compared for three-dimensional flows in industrial glass-melting furnaces. Copyright

  6. GPU accelerated solver for nonlinear reaction-diffusion systems. Application to the electrophysiology problem

    NASA Astrophysics Data System (ADS)

    Mena, Andres; Ferrero, Jose M.; Rodriguez Matas, Jose F.

    2015-11-01

    Solving the electric activity of the heart possess a big challenge, not only because of the structural complexities inherent to the heart tissue, but also because of the complex electric behaviour of the cardiac cells. The multi-scale nature of the electrophysiology problem makes difficult its numerical solution, requiring temporal and spatial resolutions of 0.1 ms and 0.2 mm respectively for accurate simulations, leading to models with millions degrees of freedom that need to be solved for thousand time steps. Solution of this problem requires the use of algorithms with higher level of parallelism in multi-core platforms. In this regard the newer programmable graphic processing units (GPU) has become a valid alternative due to their tremendous computational horsepower. This paper presents results obtained with a novel electrophysiology simulation software entirely developed in Compute Unified Device Architecture (CUDA). The software implements fully explicit and semi-implicit solvers for the monodomain model, using operator splitting. Performance is compared with classical multi-core MPI based solvers operating on dedicated high-performance computer clusters. Results obtained with the GPU based solver show enormous potential for this technology with accelerations over 50 × for three-dimensional problems.

  7. Acceleration of multiple solution of a boundary value problem involving a linear algebraic system

    NASA Astrophysics Data System (ADS)

    Gazizov, Talgat R.; Kuksenko, Sergey P.; Surovtsev, Roman S.

    2016-06-01

    Multiple solution of a boundary value problem that involves a linear algebraic system is considered. New approach to acceleration of the solution is proposed. The approach uses the structure of the linear system matrix. Particularly, location of entries in the right columns and low rows of the matrix, which undergo variation due to the computing in the range of parameters, is used to apply block LU decomposition. Application of the approach is considered on the example of multiple computing of the capacitance matrix by method of moments used in numerical electromagnetics. Expressions for analytic estimation of the acceleration are presented. Results of the numerical experiments for solution of 100 linear systems with matrix orders of 1000, 2000, 3000 and different relations of variated and constant entries of the matrix show that block LU decomposition can be effective for multiple solution of linear systems. The speed up compared to pointwise LU factorization increases (up to 15) for larger number and order of considered systems with lower number of variated entries.

  8. Applications of FLUKA Monte Carlo Code for Nuclear and Accelerator Physics

    SciTech Connect

    Battistoni, Giuseppe; Broggi, Francesco; Brugger, Markus; Campanella, Mauro; Carboni, Massimo; Empl, Anton; Fasso, Alberto; Gadioli, Ettore; Cerutti, Francesco; Ferrari, Alfredo; Ferrari, Anna; Lantz, Matthias; Mairani, Andrea; Margiotta, M.; Morone, Christina; Muraro, Silvia; Parodi, Katerina; Patera, Vincenzo; Pelliccioni, Maurizio; Pinsky, Lawrence; Ranft, Johannes; /Siegen U. /CERN /Seibersdorf, Reaktorzentrum /INFN, Milan /Milan U. /SLAC /INFN, Legnaro /INFN, Bologna /Bologna U. /CERN /HITS, Heidelberg /CERN /CERN /Frascati /CERN /CERN /CERN /CERN /NASA, Houston

    2012-04-17

    FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1 keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations. After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such topics as accelerator related applications.

  9. Applications of FLUKA Monte Carlo code for nuclear and accelerator physics

    NASA Astrophysics Data System (ADS)

    Battistoni, Giuseppe; Broggi, Francesco; Brugger, Markus; Campanella, Mauro; Carboni, Massimo; Empl, Anton; Fassò, Alberto; Gadioli, Ettore; Cerutti, Francesco; Ferrari, Alfredo; Ferrari, Anna; Lantz, Matthias; Mairani, Andrea; Margiotta, M.; Morone, Cristina; Muraro, Silvia; Parodi, Katia; Patera, Vincenzo; Pelliccioni, Mauricio; Pinsky, Larry; Ranft, Johannes; Roesler, Stefan; Rollet, Sofia; Sala, Paola R.; Santana, Mario; Sarchiapone, Lucia; Sioli, Massimiliano; Smirnov, George; Sommerer, Florian; Theis, Christian; Trovati, Stefania; Villari, R.; Vincke, Heinz; Vincke, Helmut; Vlachoudis, Vasilis; Vollaire, Joachim; Zapp, Neil

    2011-12-01

    FLUKA is a general purpose Monte Carlo code capable of handling all radiation components from thermal energies (for neutrons) or 1 keV (for all other particles) to cosmic ray energies and can be applied in many different fields. Presently the code is maintained on Linux. The validity of the physical models implemented in FLUKA has been benchmarked against a variety of experimental data over a wide energy range, from accelerator data to cosmic ray showers in the Earth atmosphere. FLUKA is widely used for studies related both to basic research and to applications in particle accelerators, radiation protection and dosimetry, including the specific issue of radiation damage in space missions, radiobiology (including radiotherapy) and cosmic ray calculations. After a short description of the main features that make FLUKA valuable for these topics, the present paper summarizes some of the recent applications of the FLUKA Monte Carlo code in the nuclear as well high energy physics. In particular it addresses such topics as accelerator related applications.

  10. Young Thinkers in Motion: Problem Solving and Physics in Preschool

    ERIC Educational Resources Information Center

    Stoll, Julia; Hamilton, Ashley; Oxley, Emilie; Eastman, Angela Mitroff; Brent, Rachael

    2012-01-01

    Physics is the study of forces and motion--the science of matter and energy and the interaction between the two. The big idea the children explore, as well as the question they ask as they engage in physical knowledge activities related to physics, is "How does it move?" Many teachers translate naturally as they come to know the children they…

  11. Relationships between undergraduates' argumentation skills, conceptual quality of problem solutions, and problem solving strategies in introductory physics

    NASA Astrophysics Data System (ADS)

    Rebello, Carina M.

    This study explored the effects of alternative forms of argumentation on undergraduates' physics solutions in introductory calculus-based physics. A two-phase concurrent mixed methods design was employed to investigate relationships between undergraduates' written argumentation abilities, conceptual quality of problem solutions, as well as approaches and strategies for solving argumentative physics problems across multiple physics topics. Participants were assigned via stratified sampling to one of three conditions (control, guided construct, or guided evaluate) based on gender and pre-test scores on a conceptual instrument. The guided construct and guided evaluate groups received tasks and prompts drawn from literature to facilitate argument construction or evaluation. Using a multiple case study design, with each condition serving as a case, interviews were conducted consisting of a think-aloud problem solving session paired with a semi-structured interview. The analysis of problem solving strategies was guided by the theoretical framework on epistemic games adapted by Tuminaro and Redish (2007). This study provides empirical evidence that integration of written argumentation into physics problems can potentially improve the conceptual quality of solutions, expand their repertoire of problem solving strategies and show promise for addressing the gender gap in physics. The study suggests further avenues for research in this area and implications for designing and implementing argumentation tasks in introductory college physics.

  12. Analytical derivation: An epistemic game for solving mathematically based physics problems

    NASA Astrophysics Data System (ADS)

    Bajracharya, Rabindra R.; Thompson, John R.

    2016-06-01

    Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the analytical derivation game. This game involves deriving an equation through symbolic manipulations and routine mathematical operations, usually without any physical interpretation of the processes. This game often creates cognitive obstacles in students, preventing them from using alternative resources or better approaches during problem solving. We conducted hour-long, semi-structured, individual interviews with fourteen introductory physics students. Students were asked to solve four "pseudophysics" problems containing algebraic and graphical representations. The problems required the application of the fundamental theorem of calculus (FTC), which is one of the most frequently used mathematical concepts in physics problem solving. We show that the analytical derivation game is necessary, but not sufficient, to solve mathematically based physics problems, specifically those involving graphical representations.

  13. Prediction of reliability on thermoelectric module through accelerated life test and Physics-of-failure

    NASA Astrophysics Data System (ADS)

    Choi, Hyoung-Seuk; Seo, Won-Seon; Choi, Duck-Kyun

    2011-09-01

    Thermoelectric cooling module (TEM) which is electric device has a mechanical stress because of temperature gradient in itself. It means that structure of TEM is vulnerable in an aspect of reliability but research on reliability of TEM was not performed a lot. Recently, the more the utilization of thermoelectric cooling devices grows, the more the needs for life prediction and improvement are increasing. In this paper, we investigated life distribution, shape parameter of the TEM through accelerated life test (ALT). And we discussed about how to enhance life of TEM through the Physics-of-failure. Experimental results of ALT showed that the thermoelectric cooling module follows the Weibull distribution, shape parameter of which is 3.6. The acceleration model is coffin Coffin-Manson and material constant is 1.8.

  14. Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens

    PubMed Central

    LeBlanc, Stephanie; Tobalske, Bret; Quinton, Margaret; Springthorpe, Dwight; Szkotnicki, Bill; Wuerbel, Hanno; Harlander-Matauschek, Alexandra

    2016-01-01

    With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15) using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5). Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch) and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask), with and without space limitations (obstacles) and combinations thereof. Video recordings (600 Hz) and a three-axis accelerometer/gyroscope (100 Hz) were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both health categories

  15. Physical Health Problems and Environmental Challenges Influence Balancing Behaviour in Laying Hens.

    PubMed

    LeBlanc, Stephanie; Tobalske, Bret; Quinton, Margaret; Springthorpe, Dwight; Szkotnicki, Bill; Wuerbel, Hanno; Harlander-Matauschek, Alexandra

    2016-01-01

    With rising public concern for animal welfare, many major food chains and restaurants are changing their policies, strictly buying their eggs from non-cage producers. However, with the additional space in these cage-free systems to perform natural behaviours and movements comes the risk of injury. We evaluated the ability to maintain balance in adult laying hens with health problems (footpad dermatitis, keel damage, poor wing feather cover; n = 15) using a series of environmental challenges and compared such abilities with those of healthy birds (n = 5). Environmental challenges consisted of visual and spatial constraints, created using a head mask, perch obstacles, and static and swaying perch states. We hypothesized that perch movement, environmental challenges, and diminished physical health would negatively impact perching performance demonstrated as balance (as measured by time spent on perch and by number of falls of the perch) and would require more exaggerated correctional movements. We measured perching stability whereby each bird underwent eight 30-second trials on a static and swaying perch: with and without disrupted vision (head mask), with and without space limitations (obstacles) and combinations thereof. Video recordings (600 Hz) and a three-axis accelerometer/gyroscope (100 Hz) were used to measure the number of jumps/falls, latencies to leave the perch, as well as magnitude and direction of both linear and rotational balance-correcting movements. Laying hens with and without physical health problems, in both challenged and unchallenged environments, managed to perch and remain off the ground. We attribute this capacity to our training of the birds. Environmental challenges and physical state had an effect on the use of accelerations and rotations to stabilize themselves on a perch. Birds with physical health problems performed a higher frequency of rotational corrections to keep the body centered over the perch, whereas, for both health categories

  16. Incorporating Problem-Based Learning in Physical Education Teacher Education

    ERIC Educational Resources Information Center

    Hushman, Glenn; Napper-Owen, Gloria

    2011-01-01

    Problem-based learning (PBL) is an educational method that identifies a problem as a context for student learning. Critical-thinking skills, deductive reasoning, knowledge, and behaviors are developed as students learn how theory can be applied to practical settings. Problem-based learning encourages self-direction, lifelong learning, and sharing…

  17. Problems Faced by Physical Handicapped Students in Educational Institutions in District Kohat

    ERIC Educational Resources Information Center

    Hussain, Ishtiaq; Bashir, Muhammad; ud Din, Muhammad Naseer; Butt, Muhammad Naeem; Akhter, Shagufa; Inamullah, Hafiz

    2011-01-01

    The purpose of the study was to explore the problems faced by physical handicapped students in normal educational institutions and to find solutions to the problems faced by physical handicapped students. All the physical handicapped students studying in educational institutions in District Kohat constituted the population of the study. The study…

  18. Towards Extreme Field Physics: Relativistic Optics and Particle Acceleration in the Transparent-Overdense Regime

    NASA Astrophysics Data System (ADS)

    Hegelich, B. Manuel

    2011-10-01

    A steady increase of on-target laser intensity with also increasing pulse contrast is leading to light-matter interactions of extreme laser fields with matter in new physics regimes which in turn enable a host of applications. A first example is the realization of interactions in the transperent-overdense regime (TOR), which is reached by interacting a highly relativistic (a0 >10), ultra high contrast laser pulse [1] with a solid density target, turning it transparent to the laser by the relativistic mass increase of the electrons. Thus, the interactions becomes volumetric, increasing the energy coupling from laser to plasma, facilitating a range of effects, including relativistic optics and pulse shaping, mono-energetic electron acceleration [3], highly efficient ion acceleration in the break-out afterburner regime [4], and the generation of relativistic and forward directed surface harmonics. Experiments at the LANL 130TW Trident laser facility successfully reached the TOR, and show relativistic pulse shaping beyond the Fourier limit, the acceleration of mono-energetic ~40 MeV electron bunches from solid targets, forward directed coherent relativistic high harmonic generation >1 keV Break-Out Afterburner (BOA) ion acceleration of Carbon to >1 GeV and Protons to >100 MeV. Carbon ions were accelerated with a conversion efficiency of >10% for ions >20 MeV and monoenergetic carbon ions with an energy spread of <20%, have been accelerated at up to ~500 MeV, demonstrating 3 out of 4 for key requirements for ion fast ignition. The shown results now approach or exceed the limits set by many applications from ICF diagnostics over ion fast ignition to medical physics. Furthermore, TOR targets traverse a wide range of HEDP parameter space during the interaction ranging from WDM conditions (e.g. brown dwarfs) to energy densities of ~1011 J/cm3 at peak, then dropping back to the underdense but extremely hot parameter range of gamma-ray bursts. Whereas today this regime can

  19. Cognitive Processes and Knowledge Structures Used in Solving Physics Problems. Final Technical Report.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.

    Cognitive processes and knowledge structures used in physics problem-solving at the high school or freshmen college level were investigated by analysis of expert and novice human problem-solving behavior and by development of computer programs which can solve informally-stated physics problems. Computer representations for the information…

  20. Report of the HEPAP Subpanel on Major Detectors in Non-Accelerator Particle Physics

    NASA Astrophysics Data System (ADS)

    1989-05-01

    The subpanel on Major Detectors in Non-Accelerator Particle Physics was formed in February 1989 as the result of a letter from Robert Hunter, Director, Office of Energy Research, to Francis Low, Chairman of HEPAP. A copy of the letter is included in the Appendix to this report. The letter referred to the previous report of HEPAP Subpanel on High Energy Gamma Ray and Neutrino Astronomy which had found that several groups of scientists were working on promising new ideas and proposals in non-accelerator high energy physics and astrophysics; this report recommended that panel be formed to evaluate large projects in these areas of science when specific proposals were received by the funding agencies. In concurring with the recommendation, the request to establish this new Subpanel included the following specific charge: Within the context of changing world wide high energy physics activities and opportunities, review as necessary and evaluate the following major research proposals which have been submitted to the Department of Energy and/or to the National Science foundation: DUMAND II, GRANDE, and the Fly's Eye Upgrade.

  1. Topics in radiation at accelerators: Radiation physics for personnel and environmental protection

    SciTech Connect

    Cossairt, J.D.

    1993-11-01

    This report discusses the following topics: Composition of Accelerator Radiation Fields; Shielding of Electrons and Photons at Accelerators; Shielding of Hadrons at Accelerators; Low Energy Prompt Radiation Phenomena; Induced Radioactivity at Accelerators; Topics in Radiation Protection Instrumentation at Accelerators; and Accelerator Radiation Protection Program Elements.

  2. Multidimensional physical activity: An opportunity not a problem

    PubMed Central

    Thompson, Dylan; Peacock, Oliver; Western, Max; Batterham, Alan M.

    2015-01-01

    Our research shows that no single metric will adequately reflect an individual’s physical activity because multiple biologically-important dimensions are independent and unrelated. We propose that there is an opportunity to exploit this multidimensional characteristic of physical activity in order to improve personalised feedback and offer physical activity options and choices that are tailored to an individual’s needs and preferences. PMID:25607280

  3. Acceleration mass spectrometer of the Budker Institute of Nuclear Physics for biomedical applications

    NASA Astrophysics Data System (ADS)

    Rastigeev, S. A.; Frolov, A. R.; Goncharov, A. D.; Klyuev, V. F.; Konstantinov, E. S.; Kutnyakova, L. A.; Parkhomchuk, V. V.; Petrozhitskii, A. V.

    2014-09-01

    An accelerator mass spectrometer (AMS) made at the Budker Institute of Nuclear Physics (BINP), Siberian Branch, Russian Academy of Sciences, is installed in the Geochronology of the Cenozoic Era Center for Collective Use for the carbon 14 dating of samples. Distinctive features of the BINP AMS include the use of a middle energy separator of ion beams, magnesium vapor target as a stripping target, and a time-of-flight telescope with thin films for accurate ion selection. Results of experiments measuring the radiocarbon concentration in test samples with radiocarbon labels for biomedical applications are presented.

  4. Helping Future Physics Teachers Learn How to Engage Students in Meaningful Problem Solving

    NASA Astrophysics Data System (ADS)

    Etkina, Eugenia

    2012-02-01

    Learning to solve problems is an important part of learning physics. Preparing future physics teachers to engage their students in meaningful problem solving is a part of a larger set of knowledge and skills called pedagogical content knowledge. One of the most common issues that students have when approaching physics problems is looking for the ``right formula'' instead of thinking about the concepts involved. What can we do to help students break this habit and learn to engage in expert-like problems solving? Answers to this question applied to specific areas of physics are a part of physics PCK. Workshop participants will learn how to approach problems solving with their pre-service physics teachers to help them develop problem-solving aspect of their PCK.

  5. Relationships between Undergraduates' Argumentation Skills, Conceptual Quality of Problem Solutions, and Problem Solving Strategies in Introductory Physics

    ERIC Educational Resources Information Center

    Rebello, Carina M.

    2012-01-01

    This study explored the effects of alternative forms of argumentation on undergraduates' physics solutions in introductory calculus-based physics. A two-phase concurrent mixed methods design was employed to investigate relationships between undergraduates' written argumentation abilities, conceptual quality of problem solutions, as well…

  6. Problems and Solutions for High School Physics in Turkey.

    ERIC Educational Resources Information Center

    Dogan, Mevlut; Oruncak, Bekir; Gunbayi, Ilhan

    2002-01-01

    Presents a study that investigates participating (n=70) teachers and (n=940) students' perceptions of physics. Reports that students have the most difficulty with magnetism but the most interest in electricity, optics, and motion. Discusses the possibilities for making physics more attractive to students. (YDS)

  7. Common Problems and Solutions for Being Physically Active

    MedlinePlus

    ... the road again… Take workout clothes when you travel. Use your hotel's health club or pool. If there isn't one, ... Concerns • What Can I Expect? Introduction Getting Physically Active - Introduction - Physical Activity & Health - What Type of Activity is Best? - Develop a ...

  8. Physics and engineering studies on the MITICA accelerator: comparison among possible design solutions

    SciTech Connect

    Agostinetti, P.; Antoni, V.; Chitarin, G.; Pilan, N.; Marcuzzi, D.; Serianni, G.; Veltri, P.; Cavenago, M.

    2011-09-26

    Consorzio RFX in Padova is currently using a comprehensive set of numerical and analytical codes, for the physics and engineering design of the SPIDER (Source for Production of Ion of Deuterium Extracted from RF plasma) and MITICA (Megavolt ITER Injector Concept Advancement) experiments, planned to be built at Consorzio RFX. This paper presents a set of studies on different possible geometries for the MITICA accelerator, with the objective to compare different design concepts and choose the most suitable one (or ones) to be further developed and possibly adopted in the experiment. Different design solutions have been discussed and compared, taking into account their advantages and drawbacks by both the physics and engineering points of view.

  9. Physical Problems Associated with Computer Use and Implemented Ergonomic Measures.

    ERIC Educational Resources Information Center

    Alexander, Melody A.

    1994-01-01

    Survey responses from 404 (of 523) office support personnel showed that most used computers 3-6 hours per day and had experienced vision or musculoskeletal problems, but most did not see a doctor, take regular breaks, do stretching exercises, or discuss problems with their supervisors. Many were not aware of ergonomic features that could help, and…

  10. Simulations of second-order Fermi acceleration of electrons: Solving the injection problem

    SciTech Connect

    Gisler, G.R.

    1991-12-31

    The boosting of electrons from a Maxwellian distribution into a suprathermal power-law tail has long been recognized as an important bottleneck governing the subsequent acceleration of some of these electrons to relativistic energies. This is the seed or injection problem. I study this boosting process using a test-particle simulation code, following the full equations of motion of tens of thousands of electrons chosen from a thermal population as they move through general time-dependent magnetic fields. Inhomogeneities in the magnetic field are provided by finite swarms of moving current loops with Maxwellian velocity distributions and power-law distributions of loop size and dipole moment strength. Whether bulk heating or boosting occurs is found to depend on the size of the swarm thermal speed compared to the electron thermal speed. When the swarm thermal speed is comparable to the electron thermal speed the entire electron population is heated by encounters with the rapidly moving current loops, approximately preserving the Maxwellian character of the electron distribution. On the other hand, at very low swarm thermal speeds there is no bulk heating; instead one percent or fewer of the electrons are boosted into a power-law suprathermal tail with a differential energy spectral index between 1 and 2. Individual boosts of 2000 and more have been observed in samples of 50,000 electrons. Most of the strongly boosted electrons have initial energies that are well below the peak of the initial Maxwellian.

  11. How to encourage university students to solve physics problems requiring mathematical skills: the 'adventurous problem solving' approach

    NASA Astrophysics Data System (ADS)

    DeMul, Frits F. M.; Batlle, Cristina Martin i.; DeBruijn, Imme; Rinzema, Kees

    2004-01-01

    Teaching physics to first-year university students (in the USA: junior/senior level) is often hampered by their lack of skills in the underlying mathematics, and that in turn may block their understanding of the physics and their ability to solve problems. Examples are vector algebra, differential expressions and multi-dimensional integrations, and the Gauss and Ampère laws learnt in electromagnetism courses. To enhance those skills in a quick and efficient way we have developed 'Integrating Mathematics in University Physics', in which students are provided with a selection of problems (exercises) that explicitly deal with the relation between physics and mathematics. The project is based on computer-assisted instruction (CAI), and available via the Internet (http://tnweb.tn.utwente.nl/onderwijs/; or http://www.utwente.nl/; search or click to: CONECT). Normally, in CAI a predefined student-guiding sequence for problem solving is used (systematic problem solving). For self-learning this approach was found to be far too rigid. Therefore, we developed the 'adventurous problem solving' (APS) method. In this new approach, the student has to find the solution by developing his own problem-solving strategy in an interactive way. The assessment of mathematical answers to physical questions is performed using a background link with an algebraic symbolic language interpreter. This manuscript concentrates on the subject of APS.

  12. The physics of sub-critical lattices in accelerator driven hybrid systems: The MUSE experiments in the MASURCA facility

    SciTech Connect

    Chauvin, J. P.; Lebrat, J. F.; Soule, R.; Martini, M.; Jacqmin, R.; Imel, G. R.; Salvatores, M.

    1999-06-10

    Since 1991, the CEA has studied the physics of hybrid systems, involving a sub-critical reactor coupled with an accelerator. These studies have provided information on the potential of hybrid systems to transmute actinides and, long lived fission products. The potential of such a system remains to be proven, specifically in terms of the physical understanding of the different phenomena involved and their modelling, as well as in terms of experimental validation of coupled systems, sub-critical environment/accelerator. This validation must be achieved through mock-up studies of the sub-critical environments coupled to a source of external neutrons. The MUSE-4 mock-up experiment is planed at the MASURCA facility and will use an accelerator coupled to a tritium target. The great step between the generator used in the past and the accelerator will allow to increase the knowledge in hybrid physic and to decrease the experimental biases and the measurement uncertainties.

  13. Physical property comparison of 11 soft denture lining materials as a function of accelerated aging.

    PubMed

    Dootz, E R; Koran, A; Craig, R G

    1993-01-01

    Soft denture-lining materials are an important treatment option for patients who have chronic soreness associated with dental prostheses. Three distinctly different types of materials are generally used. These are plasticized polymers or copolymers, silicones, or polyphosphazene fluoroelastomer. The acceptance of these materials by patients and dentists is variable. The objective of this study is to compare the tensile strength, percent elongation, hardness, tear strength, and tear energy of eight plasticized polymers or copolymers, two silicones, and one polyphosphazene fluoroelastomer. Tests were run at 24 hours after specimen preparation and repeated after 900 hours of accelerated aging in a Weather-Ometer device. The data indicated a wide range of physical properties for soft denture-lining materials and showed that accelerated aging dramatically affected the physical and mechanical properties of many of the elastomers. No soft denture liner proved to be superior to all others. The data obtained should provide clinicians with useful information for selecting soft denture lining materials for patients. PMID:8455156

  14. Tsallis entropy and complexity theory in the understanding of physics of precursory accelerating seismicity.

    NASA Astrophysics Data System (ADS)

    Vallianatos, Filippos; Chatzopoulos, George

    2014-05-01

    Strong observational indications support the hypothesis that many large earthquakes are preceded by accelerating seismic release rates which described by a power law time to failure relation. In the present work, a unified theoretical framework is discussed based on the ideas of non-extensive statistical physics along with fundamental principles of physics such as the energy conservation in a faulted crustal volume undergoing stress loading. We derive the time-to-failure power-law of: a) cumulative number of earthquakes, b) cumulative Benioff strain and c) cumulative energy released in a fault system that obeys a hierarchical distribution law extracted from Tsallis entropy. Considering the analytic conditions near the time of failure, we derive from first principles the time-to-failure power-law and show that a common critical exponent m(q) exists, which is a function of the non-extensive entropic parameter q. We conclude that the cumulative precursory parameters are function of the energy supplied to the system and the size of the precursory volume. In addition the q-exponential distribution which describes the fault system is a crucial factor on the appearance of power-law acceleration in the seismicity. Our results based on Tsallis entropy and the energy conservation gives a new view on the empirical laws derived by other researchers. Examples and applications of this technique to observations of accelerating seismicity will also be presented and discussed. This work was implemented through the project IMPACT-ARC in the framework of action "ARCHIMEDES III-Support of Research Teams at TEI of Crete" (MIS380353) of the Operational Program "Education and Lifelong Learning" and is co-financed by the European Union (European Social Fund) and Greek national funds

  15. The Application of Physical Organic Chemistry to Biochemical Problems.

    ERIC Educational Resources Information Center

    Westheimer, Frank

    1986-01-01

    Presents the synthesis of the science of enzymology from application of the concepts of physical organic chemistry from a historical perspective. Summarizes enzyme and coenzyme mechanisms elucidated prior to 1963. (JM)

  16. Physical Assertiveness. Title IX--Prospects and Problems

    ERIC Educational Resources Information Center

    Boslooper, Thomas

    1976-01-01

    As boys and girls develop individual physical skills and learn in games and sports how to compete with one another playfully, they will be on the way toward learning to relate constructively in marriage, business, professions, and politics. (MM)

  17. Numerical solution of initial-value problems in plasma physics

    SciTech Connect

    Killeen, J.

    1980-10-01

    The numerical models used in fusion research are briefly reviewed. The application of implicit difference techniques to problems in resistive magnetohydrodynamics, transport and the Fokker-Planck equation is discussed.

  18. Adapting a theoretical framework for characterizing students' use of equations in physics problem solving

    NASA Astrophysics Data System (ADS)

    Rebello, Carina M.; Rebello, N. Sanjay

    2012-02-01

    Previous studies have focused on the resources that students activate and utilize while solving a given physics problem. However, few studies explore how students relate a given resource such as an equation, to various types of physics problems and contexts and how they ascertain the meaning and applicability of that resource. We explore how students view physics equations, derive meaning from those equations, and use those equations in physics problem solving. We adapt Dubinsky and McDonald's description of APOS (action-process-object-schema) theory of learning in mathematics, to construct a theoretical framework that describes how students interpret and use equations in physics in terms of actions, processes, objects, and schemas. This framework provides a lens for understanding how students construct their understanding of physics concepts and their relation to equations. We highlight how APOS theory can be operationalized to serve as a lens for studying the use of mathematics in physics problem solving.

  19. Assessing Student Written Problem Solutions: A Problem-Solving Rubric with Application to Introductory Physics

    ERIC Educational Resources Information Center

    Docktor, Jennifer L.; Dornfeld, Jay; Frodermann, Evan; Heller, Kenneth; Hsu, Leonardo; Jackson, Koblar Alan; Mason, Andrew; Ryan, Qing X.; Yang, Jie

    2016-01-01

    Problem solving is a complex process valuable in everyday life and crucial for learning in the STEM fields. To support the development of problem-solving skills it is important for researchers and curriculum developers to have practical tools that can measure the difference between novice and expert problem-solving performance in authentic…

  20. Common Problems and Ideas of Modern Physics - Proceedings of the 6th Winter School on Hadronic Physics

    NASA Astrophysics Data System (ADS)

    Bressani, T.; Minetti, B.; Zenoni, A.

    1992-03-01

    The Table of Contents for the full book PDF is as follows: * Preface * I. COHERENCE PHENOMENA * Coherence in QCD and QED * Quantum theory of scattering for tightly coupled scatterers * Gravitational radiation antenna cross sections * The EMC effect * The Mössbauer effect * II. SUBNUCLEAR PHYSICS * Heavy quarkonium spectroscopy * Baryonium phenomenology * Physics at DAΦNE * The "Darmstadt effect" * III. NUCLEAR PHYSICS * Frontiers and Perspectives in Nuclear Physics * Nuclear physics at DAΦNE * Intermediate energy antiproton-nucleus reactions to test quantum chromodynamics * Boundary condition approach to multiple scattering off composite systems * An updated survey of experimental work on nuclear cold fusion * IV. EXPERIMENTAL TECHNIQUES AND PARTICLE ACCELERATORS * The Frascati Φ-factory project * The Obelix central detector * New trends in gas drift chambers * Multi-level triggers in modem experiments * List of Participants * Subject Index * Author Index

  1. A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

    SciTech Connect

    Mocker, Anna; Bugiel, Sebastian; Srama, Ralf; Auer, Siegfried; Baust, Guenter; Matt, Guenter; Otto, Katharina; Colette, Andrew; Drake, Keith; Kempf, Sascha; Munsat, Tobin; Shu, Anthony; Sternovsky, Zoltan; Fiege, Katherina; Postberg, Frank; Gruen, Eberhard; Heckmann, Frieder; Helfert, Stefan; Hillier, Jonathan; Mellert, Tobias; and others

    2011-09-15

    Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut fuer Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s{sup -1}. Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s{sup -1} and with diameters of between 0.05 {mu}m and 5 {mu}m. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and

  2. Technical Challenges and Scientific Payoffs of Muon BeamAccelerators for Particle Physics

    SciTech Connect

    Zisman, Michael S.

    2007-09-25

    Historically, progress in particle physics has largely beendetermined by development of more capable particle accelerators. Thistrend continues today with the recent advent of high-luminosityelectron-positron colliders at KEK and SLAC operating as "B factories,"the imminent commissioning of the Large Hadron Collider at CERN, and theworldwide development effort toward the International Linear Collider.Looking to the future, one of the most promising approaches is thedevelopment of muon-beam accelerators. Such machines have very highscientific potential, and would substantially advance thestate-of-the-art in accelerator design. A 20-50 GeV muon storage ringcould serve as a copious source of well-characterized electron neutrinosor antineutrinos (a Neutrino Factory), providing beams aimed at detectorslocated 3000-7500 km from the ring. Such long baseline experiments areexpected to be able to observe and characterize the phenomenon ofcharge-conjugation-parity (CP) violation in the lepton sector, and thusprovide an answer to one of the most fundamental questions in science,namely, why the matter-dominated universe in which we reside exists atall. By accelerating muons to even higher energies of several TeV, we canenvision a Muon Collider. In contrast with composite particles likeprotons, muons are point particles. This means that the full collisionenergy is available to create new particles. A Muon Collider has roughlyten times the energy reach of a proton collider at the same collisionenergy, and has a much smaller footprint. Indeed, an energy frontier MuonCollider could fit on the site of an existing laboratory, such asFermilab or BNL. The challenges of muon-beam accelerators are related tothe facts that i) muons are produced as a tertiary beam, with very large6D phase space, and ii) muons are unstable, with a lifetime at rest ofonly 2 microseconds. How these challenges are accommodated in theaccelerator design will be described. Both a Neutrino Factory and a Muon

  3. A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research.

    PubMed

    Mocker, Anna; Bugiel, Sebastian; Auer, Siegfried; Baust, Günter; Colette, Andrew; Drake, Keith; Fiege, Katherina; Grün, Eberhard; Heckmann, Frieder; Helfert, Stefan; Hillier, Jonathan; Kempf, Sascha; Matt, Günter; Mellert, Tobias; Munsat, Tobin; Otto, Katharina; Postberg, Frank; Röser, Hans-Peter; Shu, Anthony; Sternovsky, Zoltán; Srama, Ralf

    2011-09-01

    Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut für Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s(-1). Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s(-1) and with diameters of between 0.05 μm and 5 μm. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and

  4. A 2 MV Van de Graaff accelerator as a tool for planetary and impact physics research

    NASA Astrophysics Data System (ADS)

    Mocker, Anna; Bugiel, Sebastian; Auer, Siegfried; Baust, Günter; Colette, Andrew; Drake, Keith; Fiege, Katherina; Grün, Eberhard; Heckmann, Frieder; Helfert, Stefan; Hillier, Jonathan; Kempf, Sascha; Matt, Günter; Mellert, Tobias; Munsat, Tobin; Otto, Katharina; Postberg, Frank; Röser, Hans-Peter; Shu, Anthony; Sternovsky, Zoltán; Srama, Ralf

    2011-09-01

    Investigating the dynamical and physical properties of cosmic dust can reveal a great deal of information about both the dust and its many sources. Over recent years, several spacecraft (e.g., Cassini, Stardust, Galileo, and Ulysses) have successfully characterised interstellar, interplanetary, and circumplanetary dust using a variety of techniques, including in situ analyses and sample return. Charge, mass, and velocity measurements of the dust are performed either directly (induced charge signals) or indirectly (mass and velocity from impact ionisation signals or crater morphology) and constrain the dynamical parameters of the dust grains. Dust compositional information may be obtained via either time-of-flight mass spectrometry of the impact plasma or direct sample return. The accurate and reliable interpretation of collected spacecraft data requires a comprehensive programme of terrestrial instrument calibration. This process involves accelerating suitable solar system analogue dust particles to hypervelocity speeds in the laboratory, an activity performed at the Max Planck Institut für Kernphysik in Heidelberg, Germany. Here, a 2 MV Van de Graaff accelerator electrostatically accelerates charged micron and submicron-sized dust particles to speeds up to 80 km s-1. Recent advances in dust production and processing have allowed solar system analogue dust particles (silicates and other minerals) to be coated with a thin conductive shell, enabling them to be charged and accelerated. Refinements and upgrades to the beam line instrumentation and electronics now allow for the reliable selection of particles at velocities of 1-80 km s-1 and with diameters of between 0.05 μm and 5 μm. This ability to select particles for subsequent impact studies based on their charges, masses, or velocities is provided by a particle selection unit (PSU). The PSU contains a field programmable gate array, capable of monitoring in real time the particles' speeds and charges, and is

  5. Can short duration visual cues influence students' reasoning and eye movements in physics problems?

    NASA Astrophysics Data System (ADS)

    Madsen, Adrian; Rouinfar, Amy; Larson, Adam M.; Loschky, Lester C.; Rebello, N. Sanjay

    2013-12-01

    We investigate the effects of visual cueing on students’ eye movements and reasoning on introductory physics problems with diagrams. Participants in our study were randomly assigned to either the cued or noncued conditions, which differed by whether the participants saw conceptual physics problems overlaid with dynamic visual cues. Students in the cued condition were shown an initial problem, and if they answered that incorrectly, they were shown a series of problems each with selection and integration cues overlaid on the problem diagrams. Students in the noncued condition were also provided a series of problems, but without any visual cues. We found that significantly more participants in the cued condition answered the problems overlaid with visual cues correctly on one of the four problem sets used and a subsequent uncued problem (the transfer problem) on a different problem set. We also found that those in the cued condition spent significantly less time looking at “novicelike” areas of the diagram in the transfer problem on three of the four problem sets and significantly more time looking at the “expertlike” areas of the diagram in the transfer problem on one problem set. Thus, the use of visual cues to influence reasoning and visual attention in physics problems is promising.

  6. Comorbidity of Physical and Motor Problems in Children with Autism

    ERIC Educational Resources Information Center

    Matson, Michael L.; Matson, Johnny L.; Beighley, Jennifer S.

    2011-01-01

    Autism and the related pervasive developmental disorders are a heavily researched group of neurodevelopmental conditions. In addition to core symptoms, there are a number of other physical and motor conditions that co-occur at high rates. This paper provides a review of factors and behaviors that correlate highly with disorders on the autism…

  7. Effect of Scaffolding on Helping Introductory Physics Students Solve Quantitative Problems Involving Strong Alternative Conceptions

    ERIC Educational Resources Information Center

    Lin, Shih-Yin; Singh, Chandralekha

    2015-01-01

    It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong…

  8. Can Short Duration Visual Cues Influence Students' Reasoning and Eye Movements in Physics Problems?

    ERIC Educational Resources Information Center

    Madsen, Adrian; Rouinfar, Amy; Larson, Adam M.; Loschky, Lester C.; Rebello, N. Sanjay

    2013-01-01

    We investigate the effects of visual cueing on students' eye movements and reasoning on introductory physics problems with diagrams. Participants in our study were randomly assigned to either the cued or noncued conditions, which differed by whether the participants saw conceptual physics problems overlaid with dynamic visual cues. Students…

  9. Thinking in Terms of Sensors: Personification of Self as an Object in Physics Problem Solving

    ERIC Educational Resources Information Center

    Tabor-Morris, A. E.

    2015-01-01

    How can physics teachers help students develop consistent problem solving techniques for both simple and complicated physics problems, such as those that encompass objects undergoing multiple forces (mechanical or electrical) as individually portrayed in free-body diagrams and/or phenomenon involving multiple objects, such as Doppler effect…

  10. Analytical Derivation: An Epistemic Game for Solving Mathematically Based Physics Problems

    ERIC Educational Resources Information Center

    Bajracharya, Rabindra R.; Thompson, John R.

    2016-01-01

    Problem solving, which often involves multiple steps, is an integral part of physics learning and teaching. Using the perspective of the epistemic game, we documented a specific game that is commonly pursued by students while solving mathematically based physics problems: the "analytical derivation" game. This game involves deriving an…

  11. Students' Understanding and Application of the Area under the Curve Concept in Physics Problems

    ERIC Educational Resources Information Center

    Nguyen, Dong-Hai; Rebello, N. Sanjay

    2011-01-01

    This study investigates how students understand and apply the area under the curve concept and the integral-area relation in solving introductory physics problems. We interviewed 20 students in the first semester and 15 students from the same cohort in the second semester of a calculus-based physics course sequence on several problems involving…

  12. Examining the Relationship of Scientific Reasoning with Physics Problem Solving

    ERIC Educational Resources Information Center

    Fabby, Carol; Koenig, Kathleen

    2015-01-01

    Recent research suggests students with more formal reasoning patterns are more proficient learners. However, little research has been done to establish a relationship between scientific reasoning and problem solving abilities by novices. In this exploratory study, we compared scientific reasoning abilities of students enrolled in a college level…

  13. Existence of ``free will'' as a problem of physics

    NASA Astrophysics Data System (ADS)

    Peres, Asher

    1986-06-01

    The proof of Bell's inequality is based on the assumption that distant observers can freely and independently choose their experiments. As Bell's inequality is experimentally violated, it appears that distant physical systems may behave as a single, nonlocal, indivisible entity. This apparent contradiction is resolved. It is shown that the “free will” assumption is, under usual circumstances, an excellent approximation. I have set before you life and death, blessing and cursing: therefore choose life.... — Deuteronomy XXX, 19

  14. Emerging terawatt picosecond CO{sub 2} laser technology and possible applications in accelerator physics

    SciTech Connect

    Pogorelsky, I.V.; Ben-Zvi, I.

    1997-07-01

    The first terawatt picosecond (TWps) CO{sub 2} laser is under construction at the BNL Accelerator Test Facility (ATF). TWps-CO{sub 2} lasers, having the order of magnitude longer wavelength than the well-known table-top terawatt solid state lasers, offer new opportunities for the strong-field physics research. For processes based on electro quiver motion, such as laser wakefield acceleration (LWFA), the advantage of the new class of lasers is due to a gain of two orders of magnitude in the ponderomotive potential for the same peak power. The large average power capability of CO{sub 2} lasers is important for the generation of hard radiation through Compton back-scattering of the laser off energetic electron beams, as well as for other applications. Among them are: LWFA modules of a tentative electron-positron collider, {gamma}-{gamma} (or {gamma}-lepton) collider, a possible table-top source of high-intensity x-rays and gamma rays and the generation of polarized positron beams.

  15. Surveying college introductory physics students’ attitudes and approaches to problem solving

    NASA Astrophysics Data System (ADS)

    Mason, Andrew J.; Singh, Chandralekha

    2016-09-01

    Students’ attitudes and approaches to problem solving in physics can greatly impact their actual problem solving practices and also influence their motivation to learn and ultimately the development of expertise. We developed and validated an attitudes and approaches to problem solving (AAPS) survey and administered it to students in the introductory physics courses in a typical large research university in the US. Here, we discuss the development and validation of the survey and analysis of the student responses to the survey questions in introductory physics courses. The introductory physics students’ responses to the survey questions were also compared with those of physics faculty members and physics PhD students. We find that introductory students are in general less expert-like than the physics faculty members and PhD students. Moreover, on some AAPS survey questions, the responses of students and faculty have unexpected trends. Those trends were interpreted via individual interviews, which helped clarify reasons for those survey responses.

  16. Some Learning Problems Concerning the Use of Symbolic Language in Physics.

    ERIC Educational Resources Information Center

    De Lozano, Silvia Ragout; Cardenas, Marta

    2002-01-01

    Draws the attention of teachers of basic university physics courses to student problems concerning the interpretation of the symbolic language used in physics. Reports specific difficulties found in the first physics course related to different kinds of statements expressed in the mathematical language. (Contains 15 references.) (Author/YDS)

  17. Role of Beliefs and Emotions in Numerical Problem Solving in University Physics Education

    ERIC Educational Resources Information Center

    Bodin, Madelen; Winberg, Mikael

    2012-01-01

    Numerical problem solving in classical mechanics in university physics education offers a learning situation where students have many possibilities of control and creativity. In this study, expertlike beliefs about physics and learning physics together with prior knowledge were the most important predictors of the quality of performance of a task…

  18. Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems

    PubMed Central

    Geurts, Sofie; van der Werf, Sieberen P.; Kessels, Roy P. C.

    2015-01-01

    The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests, days, to weeks, after initial learning) are more sensitive measures than standard delayed recall measures to detect memory problems in various patient groups. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed in other populations. Here, we identified eleven studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to those of healthy controls. Signs of accelerated forgetting were found in three studies. The results of eight studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on these results, we recommend the use of a combined recall and recognition procedure to examine accelerated forgetting and we discuss the relevance of standard and optimized learning procedures in clinical practice. PMID:26106343

  19. Accelerated forgetting? An evaluation on the use of long-term forgetting rates in patients with memory problems.

    PubMed

    Geurts, Sofie; van der Werf, Sieberen P; Kessels, Roy P C

    2015-01-01

    The main focus of this review was to evaluate whether long-term forgetting rates (delayed tests, days, to weeks, after initial learning) are more sensitive measures than standard delayed recall measures to detect memory problems in various patient groups. It has been suggested that accelerated forgetting might be characteristic for epilepsy patients, but little research has been performed in other populations. Here, we identified eleven studies in a wide range of brain injured patient groups, whose long-term forgetting patterns were compared to those of healthy controls. Signs of accelerated forgetting were found in three studies. The results of eight studies showed normal forgetting over time for the patient groups. However, most of the studies used only a recognition procedure, after optimizing initial learning. Based on these results, we recommend the use of a combined recall and recognition procedure to examine accelerated forgetting and we discuss the relevance of standard and optimized learning procedures in clinical practice. PMID:26106343

  20. Using Categorization of Problems as an Instructional Tool to Help Introductory Students Learn Physics

    ERIC Educational Resources Information Center

    Mason, Andrew; Singh, Chandralekha

    2016-01-01

    The ability to categorize problems based upon underlying principles, rather than contexts, is considered a hallmark of expertise in physics problem solving. With inspiration from a classic study by Chi, Feltovich, and Glaser, we compared the categorization of 25 introductory mechanics problems based upon similarity of solution by students in large…

  1. Factors Affecting the Link between Physical Discipline and Child Externalizing Problems in Black and White Families

    ERIC Educational Resources Information Center

    Lau, Anna S.; Litrownik, Alan J.; Newton, Rae R.; Black, Maureen M.; Everson, Mark D.

    2006-01-01

    We examined contextual factors that may affect the impact of physical discipline on later child behavior problems among high-risk Black and White families. We examined race, parental warmth, and early child problems as potential moderators of the discipline-behavior problem link. The sample included 442 White and Black children and their…

  2. Relationships of Sexual, Physical, and Emotional Abuse to Emotional and Behavioral Problems among Incarcerated Adolescents.

    ERIC Educational Resources Information Center

    Gore-Felton, Cheryl; Koopman, Cheryl; McGarvey, Elizabeth; Hernandez, Nicole; Canterbury, R. J., II

    2001-01-01

    Examines the relationships of sexual, physical and emotional abuse to emotional and behavioral problems among incarcerated girls and boys. Analyses indicated that girls were more likely than boys to internalize their problems. The only abuse variable that was positively and significantly associated with emotional problems was emotional abuse.…

  3. Goals and Methodology of Research on Solving Physics Problems. TR-158.

    ERIC Educational Resources Information Center

    Novak, Gordon S., Jr.

    The research project described will identify the component skills (cognitive processes and associated knowledge structures) required for effective problem-solving, and identify the kinds of learning which can improve problem-solving ability. These areas will be investigated by means of a computer program which can solve physics problems stated in…

  4. Study on the radiation problem caused by electron beam loss in accelerator tubes

    NASA Astrophysics Data System (ADS)

    Li, Quan-Feng; Guo, Bing-Qi; Zhang, Jie-Xi; Chen, Huai-Bi

    2008-07-01

    The beam dynamic code PARMELA was used to simulate the transportation process of accelerating electrons in S-band SW linacs with different energies of 2.5, 6 and 20 MeV. The results indicated that in the ideal condition, the percentage of electron beam loss was 50% in accelerator tubes. Also we calculated the spectrum, the location and angular distribution of the lost electrons. Calculation performed by Monte Carlo code MCNP demonstrated that the radiation distribution of lost electrons was nearly uniform along the tube axis, the angular distributions of the radiation dose rates of the three tubes were similar, and the highest leaking dose was at the angle of 160° with respect to the axis. The lower the energy of the accelerator, the higher the radiation relative leakage. For the 2.5 MeV accelerator, the maximum dose rate reached 5% of the main dose and the one on the head of the electron gun was 1%, both of which did not meet the eligible protection requirement for accelerators. We adopted different shielding designs for different accelerators. The simulated result showed that the shielded radiation leaking dose rates fulfilled the requirement. Supported by National Natural Science Foundation of China (10135040)

  5. Physics Exam Problems Reconsidered: Using Logger Pro to Evaluate Student Understanding of Physics

    ERIC Educational Resources Information Center

    Milner-Bolotin, Marina; Moll, Rachel

    2008-01-01

    In the past few decades, the physics teaching community has witnessed a surge in creative and often effective ways of using technology to improve physics instruction. Most of these findings suggest how technology can help instructors create interactive learning environments and how interactivity influences the effectiveness of physics learning.…

  6. Scaffolded problem-solving, learning approaches and understanding of concepts in an introductory college physics class

    NASA Astrophysics Data System (ADS)

    Haack, Constance

    This study was an exploration of students' use of scaffolded problems as part of their homework in an introductory calculus-based physics class. The study included consideration of the possible relationship of students' meaningful and rote learning approaches. The sample was comprised of 48 students who had completed all study instruments. Of this number, 23 did homework assignments that included scaffolded problems that had been divided into multiple steps that simplify, highlight, and organize the knowledge associated with the problem solving process. The other 25 students did non-scaffolded homework assignments. The Mechanics Baseline Test, given at the beginning of the study, measured students' prior knowledge of physics concepts. The Learning Approach Questionnaire, also given at the beginning of the study, measured students' meaningful and rote approaches to learning. Student responses to 6 qualitative physics problems and their selection of concepts associated with 4 quantitative physics problems was a gauge of their understanding of physics concepts. These 10 problems were distributed between 2 classroom examinations given during the study. At the end of the study 4 students who had done scaffolded homework problems and 4 students who had done non-scaffolded homework problems participated in think aloud protocols. They verbalized their thoughts as they attempted to solve 2 physics problems. Characterizations of individual problem solving approaches emerged from the think aloud protocols. An analysis of statistical data showed that students who did scaffolded problems attained significantly greater understanding of physics concepts than students who did non-scaffolded assignments. There were no significant differences by learning approaches, and no significant interactions. This indicates that scaffolded homework problems may benefit students regardless of learning orientation. Think aloud protocols revealed patterns of difference between students who had

  7. The Interplay of Externalizing Problems and Physical and Inductive Discipline during Childhood

    PubMed Central

    Choe, Daniel Ewon; Olson, Sheryl L.; Sameroff, Arnold J.

    2013-01-01

    Children who are physically disciplined are at elevated risk for externalizing problems. Conversely, maternal reasoning and reminding of rules, or inductive discipline, is associated with fewer child externalizing problems. Few studies have simultaneously examined bidirectional associations between these forms of discipline and child adjustment using cross-informant, multi-method data. We hypothesized that less inductive and more physical discipline would predict more externalizing problems, children would have evocative effects on parenting, and high levels of either form of discipline would predict low levels of the other. In a study of 241 children–spanning ages 3, 5.5, and 10–structural equation modeling indicated that 3-year-olds with higher teacher ratings of externalizing problems received higher mother ratings of physical discipline at age 5.5. Mothers endorsing more inductive discipline at child age 3 reported less physical discipline and had children with fewer externalizing problems at age 5.5. Negative bidirectional associations emerged between physical and inductive discipline from ages 5.5 to 10. Findings suggested children’s externalizing problems elicited physical discipline, and maternal inductive discipline might help prevent externalizing problems and physical discipline. PMID:23458660

  8. Statistical physics of shear flow: a non-equilibrium problem

    NASA Astrophysics Data System (ADS)

    Evans, R. M. L.

    2010-09-01

    Complex fluids are easily and reproducibly driven into non-equilibrium steady states by the action of shear flow. The statistics of the microstructure of non-equilibrium fluids is important to the material properties of every complex fluid that flows, e.g. axle grease on a rotating bearing; blood circulating in capillaries; molten plastic flowing into a mould; the non-equilibrium onion phase of amphiphiles used for drug delivery; the list is endless. Such states are as diverse and interesting as equilibrium states, but are not governed by the same statistics as equilibrium materials. I review some recently discovered principles governing the probabilities of various types of molecular re-arrangements taking place within a sheared fluid. As well as providing new foundations for the study of non-equilibrium matter, the principles are applied to some simple models of particles interacting under flow, showing that the theory exhibits physically convincing behaviour.

  9. A New Approach to Analyzing the Cognitive Load in Physics Problems

    NASA Astrophysics Data System (ADS)

    Teodorescu, Raluca

    2010-02-01

    I will present a Taxonomy of Introductory Physics Problems (TIPP), which relates physics problems to the cognitive processes and the knowledge required to solve them. TIPP was created for designing and clarifying educational objectives, for developing assessments to evaluate components of the problem-solving process, and for guiding curriculum design in introductory physics courses. To construct TIPP, I considered processes that have been identified either by cognitive science and expert-novice research or by direct observation of students' behavior while solving physics problems. Based on Marzano and Kendall's taxonomy [1], I developed a procedure to classify physics problems according to the cognitive processes that they involve and the knowledge to which they refer. The procedure is applicable to any physics problem and its validity and reliability have been confirmed. This algorithm was then used to build TIPP, which is a database that contains text-based and research-based physics problems and explains their relationship to cognitive processes and knowledge. TIPP has been used in the years 2006--2009 to reform the first semester of the introductory algebra-based physics course at The George Washington University. The reform targeted students' cognitive development and attitudes improvement. The methodology employed in the course involves exposing students to certain types of problems in a variety of contexts with increasing complexity. To assess the effectiveness of our approach, rubrics were created to evaluate students' problem-solving abilities and the Colorado Learning Attitudes about Science Survey (CLASS) was administered pre- and post-instruction to determine students' shift in dispositions towards learning physics. Our results show definitive gains in the areas targeted by our curricular reform.[4pt] [1] R.J. Marzano and J.S. Kendall, The New Taxonomy of Educational Objectives, 2^nd Ed., (Corwin Press, Thousand Oaks, 2007). )

  10. Hyperbolic metamaterials: new physics behind a classical problem.

    PubMed

    Drachev, Vladimir P; Podolskiy, Viktor A; Kildishev, Alexander V

    2013-06-17

    Hyperbolic materials enable numerous surprising applications that include far-field subwavelength imaging, nanolithography, and emission engineering. The wavevector of a plane wave in these media follows the surface of a hyperboloid in contrast to an ellipsoid for conventional anisotropic dielectric. The consequences of hyperbolic dispersion were first studied in the 50's pertaining to the problems of electromagnetic wave propagation in the Earth's ionosphere and in the stratified artificial materials of transmission lines. Recent years have brought explosive growth in optics and photonics of hyperbolic media based on metamaterials across the optical spectrum. Here we summarize earlier theories in the Clemmow's prescription for transformation of the electromagnetic field in hyperbolic media and provide a review of recent developments in this active research area. PMID:23787692

  11. Physical processes at work in sub-30 fs, PW laser pulse-driven plasma accelerators: Towards GeV electron acceleration experiments at CILEX facility

    NASA Astrophysics Data System (ADS)

    Beck, A.; Kalmykov, S. Y.; Davoine, X.; Lifschitz, A.; Shadwick, B. A.; Malka, V.; Specka, A.

    2014-03-01

    Optimal regimes and physical processes at work are identified for the first round of laser wakefield acceleration experiments proposed at a future CILEX facility. The Apollon-10P CILEX laser, delivering fully compressed, near-PW-power pulses of sub-25 fs duration, is well suited for driving electron density wakes in the blowout regime in cm-length gas targets. Early destruction of the pulse (partly due to energy depletion) prevents electrons from reaching dephasing, limiting the energy gain to about 3 GeV. However, the optimal operating regimes, found with reduced and full three-dimensional particle-in-cell simulations, show high energy efficiency, with about 10% of incident pulse energy transferred to 3 GeV electron bunches with sub-5% energy spread, half-nC charge, and absolutely no low-energy background. This optimal acceleration occurs in 2 cm length plasmas of electron density below 1018 cm-3. Due to their high charge and low phase space volume, these multi-GeV bunches are tailor-made for staged acceleration planned in the framework of the CILEX project. The hallmarks of the optimal regime are electron self-injection at the early stage of laser pulse propagation, stable self-guiding of the pulse through the entire acceleration process, and no need for an external plasma channel. With the initial focal spot closely matched for the nonlinear self-guiding, the laser pulse stabilizes transversely within two Rayleigh lengths, preventing subsequent evolution of the accelerating bucket. This dynamics prevents continuous self-injection of background electrons, preserving low phase space volume of the bunch through the plasma. Near the end of propagation, an optical shock builds up in the pulse tail. This neither disrupts pulse propagation nor produces any noticeable low-energy background in the electron spectra, which is in striking contrast with most of existing GeV-scale acceleration experiments.

  12. Analysing Cognitive or Non-Cognitive Factors Involved in the Process of Physics Problem-Solving in an Everyday Context

    ERIC Educational Resources Information Center

    Park, Jongwon; Lee, Limook

    2004-01-01

    Recently, the importance of an everyday context in physics learning, teaching, and problem-solving has been emphasized. However, do students or physics educators really want to learn or teach physics problem-solving in an everyday context? Are there not any obstructive factors to be considered in solving the everyday context physics problems? To…

  13. Factors Associated with Time to Identify Physical Problems of Nursing Home Residents with Dementia

    PubMed Central

    Kovach, Christine R.; Logan, Brent R.; Simpson, Michelle R.; Reynolds, Sheila

    2010-01-01

    This study describes new problems emerging over six weeks for nursing home residents with advanced dementia and factors associated with time to identify the problems. The sample of 65 developed 149 new acute problems or exacerbations of existing conditions over the six weeks of data collection. The majority of these problems involved uncontrolled pain, new infections and severe psychoses. Nurse assessment skill was associated with a shorter time to identify the new problem and more time spent on the problem. A higher ratio of new to existing interventions was also associated with a shorter time to identify the problem. Other patient characteristics associated with time to identify problems included non-specific vocalizations, physical signs, cognitive status and length of stay. While future research is warranted, findings from this study highlight the frequency of problems requiring treatment and suggest that improved assessment of residents may decrease the time to identify new problems. PMID:20237337

  14. A nuclear physics program at the Rare Isotope Beams Accelerator Facility in Korea

    SciTech Connect

    Moon, Chang-Bum

    2014-04-15

    This paper outlines the new physics possibilities that fall within the field of nuclear structure and astrophysics based on experiments with radioactive ion beams at the future Rare Isotope Beams Accelerator facility in Korea. This ambitious multi-beam facility has both an Isotope Separation On Line (ISOL) and fragmentation capability to produce rare isotopes beams (RIBs) and will be capable of producing and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. The large dynamic range of reaccelerated RIBs will allow the optimization in each nuclear reaction case with respect to cross section and channel opening. The low energy RIBs around Coulomb barrier offer nuclear reactions such as elastic resonance scatterings, one or two particle transfers, Coulomb multiple-excitations, fusion-evaporations, and direct capture reactions for the study of the very neutron-rich and proton-rich nuclides. In contrast, the high energy RIBs produced by in-flight fragmentation with reaccelerated ions from the ISOL enable to explore the study of neutron drip lines in intermediate mass regions. The proposed studies aim at investigating the exotic nuclei near and beyond the nucleon drip lines, and to explore how nuclear many-body systems change in such extreme regions by addressing the following topics: the evolution of shell structure in areas of extreme proton to neutron imbalance; the study of the weak interaction in exotic decay schemes such as beta-delayed two-neutron or two-proton emission; the change of isospin symmetry in isobaric mirror nuclei at the drip lines; two protons or two neutrons radioactivity beyond the drip lines; the role of the continuum states including resonant states above the particle-decay threshold in exotic nuclei; and the effects of nuclear reaction rates triggered by the unbound proton-rich nuclei on nuclear astrophysical processes.

  15. Using the context of physics problem-solving to evaluate the coherence of student knowledge

    NASA Astrophysics Data System (ADS)

    Sabella, Mel Stephan

    We use the context of problem solving to show that students exhibit a local coherence but not a global coherence in their physics knowledge. When presented with a problem-solving task, students often activate a coherent set of knowledge called a schema to solve the problem. This schema consists of strongly related knowledge and procedures. Although the schemas students develop in the physics course are usually sufficient for success in the class, they are often insufficient for solving complex problems. Complex problems require that students have a deep understanding where they have integrated their qualitative knowledge with their quantitative knowledge and have integrated related physics topics. We show that our students activate schemas consisting of small amounts of knowledge and these schemas are often isolated from other schemas. Physics Education Research (PER) has shown that students in introductory physics lack a deep understanding of physics principles and concepts. Through research-based curricula, conceptual understanding can be improved. In addition PER has shown that students can be taught problem solving skills through a modified curriculum. Despite these improvements, students still have difficulty developing a coherent knowledge of physics. In particular, students often have difficulty connecting related physics concepts. In addition, they view quantitative problems and qualitative questions as distinct types of tasks, possessing different types of knowledge and different sets of rules for responding. We discuss some possible methods that physics instructors and physics education researchers can use to examine coherence in student knowledge. Using these methods, we provide evidence for the local coherence in student physics knowledge by identifying distinct schemas for different physics topics and concepts, as well as distinct schemas for qualitative and quantitative knowledge. After identifying some of these difficulties in student understanding

  16. Requirements of a proton beam accelerator for an accelerator-driven reactor

    SciTech Connect

    Takahashi, H.; Zhao, Y.; Tsoupas, N.; An, Y.; Yamazaki, Y.

    1997-12-31

    When the authors first proposed an accelerator-driven reactor, the concept was opposed by physicists who had earlier used the accelerator for their physics experiments. This opposition arose because they had nuisance experiences in that the accelerator was not reliable, and very often disrupted their work as the accelerator shut down due to electric tripping. This paper discusses the requirements for the proton beam accelerator. It addresses how to solve the tripping problem and how to shape the proton beam.

  17. Summary Report of Working Group 3: High Energy Density Physics and Exotic Acceleration Schemes

    SciTech Connect

    Shvets, Gennady; Schoessow, Paul

    2006-11-27

    This report summarizes presented results and discussions in the Working Group 3 at the Twelfth Advanced Accelerator Concepts Workshop in 2006. Presentations on varied topics, such as laser proton acceleration, novel radiation sources, active medium accelerators, and many others, are reviewed, and the status and future directions of research in these areas are summarized.

  18. Using categorization of problems as an instructional tool to help introductory students learn physics

    NASA Astrophysics Data System (ADS)

    Mason, Andrew; Singh, Chandralekha

    2016-03-01

    The ability to categorize problems based upon underlying principles, rather than contexts, is considered a hallmark of expertise in physics problem solving. With inspiration from a classic study by Chi, Feltovich, and Glaser, we compared the categorization of 25 introductory mechanics problems based upon similarity of solution by students in large calculus-based introductory courses with physics faculty and PhD students. Here, we summarize the study and suggest that a categorization task, especially when conducted with students working with peers in small groups, can be an effective pedagogical tool to help students in introductory physics courses learn to discern the underlying similarity between problems with diverse contexts but the same underlying physics principles.

  19. Organ preservation at low temperature: a physical and biological problem

    NASA Astrophysics Data System (ADS)

    Aussedat, J.; Boutron, P.; Coquilhat, P.; Descotes, J. L.; Faure, G.; Ferrari, M.; Kay, L.; Mazuer, J.; Monod, P.; Odin, J.; Ray, A.

    1993-02-01

    Before reporting the preliminary results obtained by our group, we first review the main problems to be solved in the preservation of organs at very low temperature, before being transplanted. This cryopreservation is being presently explored in order to increase the preservation tiine of transplants and to contribute to a better control of the donor recipient compatibility. We recall that, for the isolated cells to be preserved at nitrogen liquid temperatures, as now successfully performed at industrial scale, it is necessary to immerse the cells in a solution containing more or less t,oxical additives (so-called cryopro tect ants). Furthermore cooling and warming rates must be specific of each type of cells. We then show that cryo preservation could be extrapolated to whole organs by means of vitrification, the only way to avoid any ice crystallization. This vitrification will be the result of two directions of research, the one on the elaboration of cryoprotective solutions, the least toxic possible, the other on the obtention of high enough and homogeneous cooling and warming rates. After having briefly summarized the state of research on the heart and kidneys of small mammals, we present the first results that we have obtained on perfusion at 4 ^{circ}C and the auto-transplantation of rabbit kidneys, on the toxicity of a new cryoprotectant, 2,3-butanediol, on the heart rate, and on the cooling of experimental models of organs. Avant de présenter les résultats préliminaires obtenus par notre groupe, nous passons d'abord en revue les principaux problèmes à résoudre pour conserver à très basse température des organes en vue de leur transplantation. Cette cryopréservation est une voie de recherche actuellement explorée pour augmenter la durée de conservation des greffons et permettre ainsi de mieux contrôler la compatibilité donneur-receveur. Nous rappelons que la conservation des cellules isolées à la température de l'azote liquide, actuellement

  20. Operational Radiation Protection in High-Energy Physics Accelerators: Implementation of ALARA in Design and Operation of Accelerators

    SciTech Connect

    Fasso, A.; Rokni, S.; /SLAC

    2011-06-30

    It used to happen often, to us accelerator radiation protection staff, to be asked by a new radiation worker: ?How much dose am I still allowed?? And we smiled looking at the shocked reaction to our answer: ?You are not allowed any dose?. Nowadays, also thanks to improved training programs, this kind of question has become less frequent, but it is still not always easy to convince workers that staying below the exposure limits is not sufficient. After all, radiation is still the only harmful agent for which this is true: for all other risks in everyday life, from road speed limits to concentration of hazardous chemicals in air and water, compliance to regulations is ensured by keeping below a certain value. It appears that a tendency is starting to develop to extend the radiation approach to other pollutants (1), but it will take some time before the new attitude makes it way into national legislations.

  1. Differences in visual attention between those who correctly and incorrectly answer physics problems

    NASA Astrophysics Data System (ADS)

    Madsen, Adrian M.; Larson, Adam M.; Loschky, Lester C.; Rebello, N. Sanjay

    2012-06-01

    This study investigated how visual attention differed between those who correctly versus incorrectly answered introductory physics problems. We recorded eye movements of 24 individuals on six different conceptual physics problems where the necessary information to solve the problem was contained in a diagram. The problems also contained areas consistent with a novicelike response and areas of high perceptual salience. Participants ranged from those who had only taken one high school physics course to those who had completed a Physics Ph.D. We found that participants who answered correctly spent a higher percentage of time looking at the relevant areas of the diagram, and those who answered incorrectly spent a higher percentage of time looking in areas of the diagram consistent with a novicelike answer. Thus, when solving physics problems, top-down processing plays a key role in guiding visual selective attention either to thematically relevant areas or novicelike areas depending on the accuracy of a student’s physics knowledge. This result has implications for the use of visual cues to redirect individuals’ attention to relevant portions of the diagrams and may potentially influence the way they reason about these problems.

  2. Physically Abused Women's Experiences of Sexual Victimization and their Children's Disruptive Behavior Problems.

    PubMed

    Spiller, Laura C; Jouriles, Ernest N; McDonald, Renee; Skopp, Nancy A

    2012-10-01

    OBJECTIVE: Despite the substantial co-occurrence of women's experiences of physical and sexual violence, very little is known about their separate and combined effects on child functioning. The present study examines whether sexual victimization experienced by physically abused women is associated with their children's disruptive behavior problems, after controlling for mothers' physical victimization and parent to child aggression. It also tests the hypothesis that maternal distress mediates the association between women's sexual victimization and their children's disruptive behavior problems. METHOD: The sample includes 449 mothers and their children (4-8 years) who were recruited while residing in domestic violence shelters. Mothers reported on their experiences of physical and sexual victimization over the past year and their current symptoms of psychological distress. Trained diagnosticians interviewed mothers about their children's disruptive behavior problems. RESULTS: Approximately 75% of the women reported experiences of sexual victimization. Physically abused women's experiences of sexual victimization correlated positively with their children's disruptive behavior problems and their own psychological distress. The results of path analyses indicated that maternal psychological distress mediates the relation between women's experiences of sexual victimization and their children's disruptive behavior problems. CONCLUSIONS: This research suggests that physically abused women's experiences of sexual victimization are important for understanding their children's disruptive behavior problems. Additionally, this research provides further evidence that maternal psychological distress is important for understanding how intimate partner violence might influence children. PMID:23166861

  3. Effect of scaffolding on helping introductory physics students solve quantitative problems involving strong alternative conceptions

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Yin; Singh, Chandralekha

    2015-12-01

    It is well known that introductory physics students often have alternative conceptions that are inconsistent with established physical principles and concepts. Invoking alternative conceptions in the quantitative problem-solving process can derail the entire process. In order to help students solve quantitative problems involving strong alternative conceptions correctly, appropriate scaffolding support can be helpful. The goal of this study is to examine how different scaffolding supports involving analogical problem-solving influence introductory physics students' performance on a target quantitative problem in a situation where many students' solution process is derailed due to alternative conceptions. Three different scaffolding supports were designed and implemented in calculus-based and algebra-based introductory physics courses involving 410 students to evaluate the level of scaffolding needed to help students learn from an analogical problem that is similar in the underlying principles involved but for which the problem-solving process is not derailed by alternative conceptions. We found that for the quantitative problem involving strong alternative conceptions, simply guiding students to work through the solution of the analogical problem first was not enough to help most students discern the similarity between the two problems. However, if additional scaffolding supports that directly helped students examine and repair their knowledge elements involving alternative conceptions were provided, e.g., by guiding students to contemplate related issues and asking them to solve the targeted problem on their own first before learning from the analogical problem provided, students were more likely to discern the underlying similarities between the problems and avoid getting derailed by alternative conceptions when solving the targeted problem. We also found that some scaffolding supports were more effective in the calculus-based course than in the algebra

  4. The Coronal Physics Investigator (cpi) Experiment For Iss: A New Vision For Understanding Solar Wind Acceleration

    NASA Astrophysics Data System (ADS)

    Raymond, John C.; Janzen, P. H.; Kohl, J. L.; Reisenfeld, D. B.; Chandran, B. D. G.; Cranmer, S. R.; Forbes, T. G.; Isenberg, P. A.; Panasyuk, A. V.; van Ballegooijen, A. A.

    2011-05-01

    We propose an Explorer Mission of Opportunity program to develop and operate a large-aperture ultraviolet coronagraph spectrometer called the Coronal Physics Investigator (CPI) as an attached International Space Station (ISS) payload. The primary goal of this program is to identify and characterize the physical processes that heat and accelerate the primary and secondary components of the fast and slow solar wind. Also, CPI can make key measurements needed to understand CMEs. CPI is dedicated to high spectral resolution measurements of the off-limb extended corona with far better stray light suppression than can be achieved by a conventional instrument. UVCS/SOHO allowed us to identify what additional measurements need to be made to answer the fundamental questions about how solar wind streams are produced, and CPI's next-generation capabilities were designed specifically to make those measurements. Compared to previous instruments, CPI provides unprecedented sensitivity, a wavelength range extending from 25.7 to 126 nm, higher temporal resolution, and the capability to measure line profiles of He II, N V, Ne VII, Ne VIII, Si VIII, S IX, Ar VIII, Ca IX, and Fe X, never before seen in coronal holes above 1.3 solar radii. CPI will constrain the properties and effects of coronal MHD waves by (1) observing many ions over a large range of charge and mass,(2) providing simultaneous measurements of proton and electron temperatures to probe turbulent dissipation mechanisms, and (3) measuring amplitudes of low-frequency compressive fluctuations. CPI is an internally occulted ultraviolet coronagraph that provides the required high sensitivity without the need for a deployable boom, and with all technically mature hardware including an ICCD detector. A highly experienced Explorer and ISS contractor, L-3 Com Integrated Optical Systems and Com Systems East will provide the tracking and pointing system as well as the instrument, and the integration to the ISS.

  5. Method of a Generalized Physical Property in the Crystal Physics Problems

    NASA Astrophysics Data System (ADS)

    Davydov, V. N.; Lugina, N. É.

    2016-06-01

    A method is proposed for determining the crystallographic directions in crystals of various point symmetry, along which the combination of physical properties of various ranks and Curie symmetry gets a predetermined value. The method is demonstrated for the combination of the second-rank tensors describing optical and thermal properties of crystals of the monoclinic system. The possibility of using the proposed method for the physical properties of high ranks is demonstrated.

  6. The Nature and Role of Thought Experiments in Solving Conceptual Physics Problems

    ERIC Educational Resources Information Center

    Kösem, Sule Dönertas; Özdemir, Ömer Faruk

    2014-01-01

    This study describes the possible variations of thought experiments in terms of their nature, purpose, and reasoning resources adopted during the solution of conceptual physics problems. A phenomenographic research approach was adopted for this study. Three groups of participants with varying levels of physics knowledge--low, medium, and high…

  7. Association between Psychopathology and Physical Health Problems among Youth in Residential Treatment

    ERIC Educational Resources Information Center

    Nelson, Timothy D.; Smith, Tori R.; Duppong Hurley, Kristin; Epstein, Michael H.; Thompson, Ronald W.; Tonniges, Thomas F.

    2013-01-01

    Youth in residential treatment settings often present with a complex combination of mental and physical health problems. Despite an emerging literature documenting significant associations between mental health and physical health, the relationship between these two areas of functioning has not been systematically examined in youth presenting to…

  8. The Use of Metacognitive Knowledge Patterns to Compose Physics Higher Order Thinking Problems

    ERIC Educational Resources Information Center

    Abdullah, Helmi; Malago, Jasruddin D.; Bundu, Patta; Thalib, Syamsul Bachri

    2013-01-01

    The main aspect in physics learning is the use of equation in problem solving. Equation is a mathematical form of theoretical statements, principles, and laws in physics, and describes a relationship between one concept to another by using a specific symbol. In a context of knowledge dimension, equation is a procedural knowledge. Students are…

  9. Types and Qualities of Knowledge and Their Relations to Problem Solving in Physics

    ERIC Educational Resources Information Center

    Friege, Gunnar; Lind, Gunter

    2006-01-01

    Based on empirical findings and theoretical considerations related to the field of expertise research, the importance of "types" and "qualities" of knowledge in relation to problem solving in physics was investigated. The students (N = 138) in this study had a level of competence that corresponds to an intensive beginner college course in physics.…

  10. Analyzing Log Files to Predict Students' Problem Solving Performance in a Computer-Based Physics Tutor

    ERIC Educational Resources Information Center

    Lee, Young-Jin

    2015-01-01

    This study investigates whether information saved in the log files of a computer-based tutor can be used to predict the problem solving performance of students. The log files of a computer-based physics tutoring environment called Andes Physics Tutor was analyzed to build a logistic regression model that predicted success and failure of students'…

  11. Teachers' and Students' Perceptions of Students' Problem-Solving Difficulties in Physics: Implications for Remediation

    ERIC Educational Resources Information Center

    Ogunleye, Ayodele O.

    2009-01-01

    In recent times, science education researchers have identified a lot of instruments for evaluating conceptual understanding as well as students' attitudes and beliefs about physics; unfortunately however, there are no broad based evaluation instruments in the field of problem-solving in physics. This missing tool is an indication of the complexity…

  12. FOREWORD: International Scientific Seminars on "Fundamental and Applied Problems of Photonics and Condensed Matter Physics"

    NASA Astrophysics Data System (ADS)

    Yurchenko, Stanislav; Ryzhii, Viktor

    2015-01-01

    International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics'' were held in Bauman Moscow State Technical University (BMSTU) in May - June 2014. The idea of the Seminars was to organize a series of meetings between young scientists and discuss actual problems and the latest results in Photonics and Condensed Matter Physics. There were eight Sessions: Modern Problems of Condensed Matter Physics; Laser Physics; Spectroscopy of Condensed Matter; Terahertz Optical Technology; Optical Signals Processing; Physics of Optical Strong Correlated Systems; Complex Dusty Plasma Physics; Biomediacal Applications of Photonics. Seminars were organized by the young group of scientists and students from Research and Educational Center ''Photonics and Infrared Technology'' at BMSTU. It brought a significant contribution to the development of youth science in the field of Physics and Photonics in Russia. More than 100 young scientists and students participated in the Seminars in spring - summer 2014. The International Scientific Seminars were supported by the Russian Foundation for Basic Research (grant # 14-08-06030-g). This volume contains proceedings of the International Scientific Seminars ''Fundamental and Applied Problems of Photonics and Condensed Matter Physics''. Stanislav Yurchenko and Viktor Ryzhii Bauman Moscow State Technical University

  13. Investigation of the Perceived Causes of Pre-Service Physics Teachers' Problems Encountered in School Experience

    ERIC Educational Resources Information Center

    Körhasan, Nilüfer Didis; Didis, M. Gözde

    2015-01-01

    This study investigates a group of pre-service physics teachers' perceptions about the causes of problems in school experience through the attribution theory. The participants were thirteen pre-service physics teachers from a public university in Turkey. Data were collected through the interviews by requesting the participants to reflect their own…

  14. The Prevalence and Impact of Voice Problems among Physical Education Teachers

    ERIC Educational Resources Information Center

    Ryan, Stu; Rotunda, Robert; Song, Charlie; Maina, Michael

    2012-01-01

    The focus of this research effort was to examine the prevalence and impact of voice problems among a sample of physical education teachers. The survey was administered to K-12 physical education teachers (n = 199) addressing three aspects of voice issues: consequences, strategies for prevention, and potential risk factors. The results indicated a…

  15. Do Students Trust in Mathematics or Intuition during Physics Problem Solving? An Epistemic Game Perspective

    ERIC Educational Resources Information Center

    Yavuz, Ahmet

    2015-01-01

    This study aims to investigate (1) students' trust in mathematics calculation versus intuition in a physics problem solving and (2) whether this trust is related to achievement in physics in the context of epistemic game theoretical framework. To achieve this research objective, paper-pencil and interview sessions were conducted. A paper-pencil…

  16. Influence of visual cueing and outcome feedback on physics problem solving and visual attention

    NASA Astrophysics Data System (ADS)

    Rouinfar, Amy

    Research has demonstrated that attentional cues overlaid on diagrams and animations can help students attend to the relevant areas and facilitate problem solving. In this study we investigate the influence of visual cues and outcome feedback on students' problem solving, performance, reasoning, and visual attention as they solve conceptual physics problems containing a diagram. The participants (N=90) were enrolled in an algebra-based physics course and were individually interviewed. During each interview students solved four problem sets while their eye movements were recorded. The problem diagrams contained regions that were relevant to solving the problem correctly and separate regions related to common incorrect responses. Each problem set contained an initial problem, six isomorphic training problems, and a transfer problem. Those in the cued condition saw visual cues overlaid on the training problems. Those in the feedback conditions were told if their responses (answer and explanation) were correct or incorrect. Students' verbal responses were used to determine their accuracy. The study produced two major findings. First, short duration visual cues coupled with correctness feedback can improve problem solving performance on a variety of insight physics problems, including transfer problems not sharing the surface features of the training problems, but instead sharing the underlying solution path. Thus, visual cues can facilitate re-representing a problem and overcoming impasse, enabling a correct solution. Importantly, these cueing effects on problem solving did not involve the solvers' attention necessarily embodying the solution to the problem. Instead, the cueing effects were caused by solvers attending to and integrating relevant information in the problems into a solution path. Second, these short duration visual cues when administered repeatedly over multiple training problems resulted in participants becoming more efficient at extracting the relevant

  17. Accelerated Cartesian expansions for the rapid solution of periodic multiscale problems

    DOE PAGESBeta

    Baczewski, Andrew David; Dault, Daniel L.; Shanker, Balasubramaniam

    2012-07-03

    We present an algorithm for the fast and efficient solution of integral equations that arise in the analysis of scattering from periodic arrays of PEC objects, such as multiband frequency selective surfaces (FSS) or metamaterial structures. Our approach relies upon the method of Accelerated Cartesian Expansions (ACE) to rapidly evaluate the requisite potential integrals. ACE is analogous to FMM in that it can be used to accelerate the matrix vector product used in the solution of systems discretized using MoM. Here, ACE provides linear scaling in both CPU time and memory. Details regarding the implementation of this method within themore » context of periodic systems are provided, as well as results that establish error convergence and scalability. In addition, we also demonstrate the applicability of this algorithm by studying several exemplary electrically dense systems.« less

  18. Accelerated Cartesian expansions for the rapid solution of periodic multiscale problems

    SciTech Connect

    Baczewski, Andrew David; Dault, Daniel L.; Shanker, Balasubramaniam

    2012-07-03

    We present an algorithm for the fast and efficient solution of integral equations that arise in the analysis of scattering from periodic arrays of PEC objects, such as multiband frequency selective surfaces (FSS) or metamaterial structures. Our approach relies upon the method of Accelerated Cartesian Expansions (ACE) to rapidly evaluate the requisite potential integrals. ACE is analogous to FMM in that it can be used to accelerate the matrix vector product used in the solution of systems discretized using MoM. Here, ACE provides linear scaling in both CPU time and memory. Details regarding the implementation of this method within the context of periodic systems are provided, as well as results that establish error convergence and scalability. In addition, we also demonstrate the applicability of this algorithm by studying several exemplary electrically dense systems.

  19. Hybrid parallel code acceleration methods in full-core reactor physics calculations

    SciTech Connect

    Courau, T.; Plagne, L.; Ponicot, A.; Sjoden, G.

    2012-07-01

    When dealing with nuclear reactor calculation schemes, the need for three dimensional (3D) transport-based reference solutions is essential for both validation and optimization purposes. Considering a benchmark problem, this work investigates the potential of discrete ordinates (Sn) transport methods applied to 3D pressurized water reactor (PWR) full-core calculations. First, the benchmark problem is described. It involves a pin-by-pin description of a 3D PWR first core, and uses a 8-group cross-section library prepared with the DRAGON cell code. Then, a convergence analysis is performed using the PENTRAN parallel Sn Cartesian code. It discusses the spatial refinement and the associated angular quadrature required to properly describe the problem physics. It also shows that initializing the Sn solution with the EDF SPN solver COCAGNE reduces the number of iterations required to converge by nearly a factor of 6. Using a best estimate model, PENTRAN results are then compared to multigroup Monte Carlo results obtained with the MCNP5 code. Good consistency is observed between the two methods (Sn and Monte Carlo), with discrepancies that are less than 25 pcm for the k{sub eff}, and less than 2.1% and 1.6% for the flux at the pin-cell level and for the pin-power distribution, respectively. (authors)

  20. Featured Article: Accelerated decline of physical strength in peroxiredoxin-3 knockout mice.

    PubMed

    Zhang, Yong-Gang; Wang, Li; Kaifu, Tomonori; Li, Jingmin; Li, Xiaoyan; Li, Lianqin

    2016-07-01

    As a member of peroxiredoxin family, peroxiredoxin-3 plays a major role in the control of mitochondrial level of reactive oxygen species. During the breeding of experimental mice, we noticed that the peroxiredoxin-3 knockout mice were listless with aging. In the present study, we compared the swimming exercise performance and oxidative status between peroxiredoxin-3 knockout mice (n = 15) and wild-type littermates (n = 15). At the age of 10 months, the physical strength of peroxiredoxin-3 knockout mice was much lower than the wild-type littermates. Increased oxidative damage and decreased mitochondrial DNA copy number of the animal skeletal muscles were observed in peroxiredoxin-3 knockout mice as compared to that in the wild-type littermates. In addition, we found increased apoptotic cells in the brains of peroxiredoxin-3 knockout mice. Our results suggest that the deficiency of peroxiredoxin-3 induces accelerated oxidative stress and mitochondrial impairment, resulting in the decrease of energy supply and cellular activities. Peroxiredoxin-3 might be involved in the inhibition of aging process. PMID:27037278

  1. On the physics of waves in the solar atmosphere: Wave heating and wind acceleration

    NASA Technical Reports Server (NTRS)

    Musielak, Z. E.

    1993-01-01

    This paper presents work performed on the generation and physics of acoustic waves in the solar atmosphere. The investigators have incorporated spatial and temporal turbulent energy spectra in a newly corrected version of the Lighthill-Stein theory of acoustic wave generation in order to calculate the acoustic wave energy fluxes generated in the solar convective zone. The investigators have also revised and improved the treatment of the generation of magnetic flux tube waves, which can carry energy along the tubes far away from the region of their origin, and have calculated the tube energy fluxes for the sun. They also examine the transfer of the wave energy originated in the solar convective zone to the outer atmospheric layers through computation of wave propagation and dissipation in highly nonhomogeneous solar atmosphere. These waves may efficiently heat the solar atmosphere and the heating will be especially significant in the chromospheric network. It is also shown that the role played by Alfven waves in solar wind acceleration and coronal hole heating is dominant. The second part of the project concerned investigation of wave propagation in highly inhomogeneous stellar atmospheres using an approach based on an analytic tool developed by Musielak, Fontenla, and Moore. In addition, a new technique based on Dirac equations has been developed to investigate coupling between different MHD waves propagating in stratified stellar atmospheres.

  2. Exploring University Students' Expectations and Beliefs about Physics and Physics Learning in a Problem-Based Learning Context

    ERIC Educational Resources Information Center

    Sahin, Mehmet

    2009-01-01

    This paper reports the results of an exploratory study aimed to determine university students' expectations and beliefs in a problem-based introductory physics course, how those expectations compare to that of students in other universities, and change as a result of one semester of instruction. In total, 264 freshmen engineering students of Dokuz…

  3. The Interplay of Externalizing Problems and Physical and Inductive Discipline during Childhood

    ERIC Educational Resources Information Center

    Choe, Daniel Ewon; Olson, Sheryl L.; Sameroff, Arnold J.

    2013-01-01

    Children who are physically disciplined are at elevated risk for externalizing problems. Conversely, maternal reasoning and reminding of rules, or inductive discipline, is associated with fewer child externalizing problems. Few studies have simultaneously examined bidirectional associations between these forms of discipline and child adjustment…

  4. Problems of bound states in plasmas—physical and chemical picture revisited

    NASA Astrophysics Data System (ADS)

    Ebeling, W.

    2008-12-01

    We discuss several problems of plasma physics which were in the center of interest of the Rostock group and the research activities of Gerd Röpke who was appointed a docent in 1977 by Rostock University. In particular we will consider the problem of bound states and several approaches to treat bound states in dense systems.

  5. Scaffolded Problem-Solving in the Physics and Chemistry Laboratory: Difficulties Hindering Students' Assumption of Responsibility

    ERIC Educational Resources Information Center

    Reigosa, Carlos; Jimenez-Aleixandre, Maria-Pilar

    2007-01-01

    This case study examines the performances of 18 10th-grade students (age 15-16 years) in the process of performing problem-solving tasks in the physics and chemistry laboratory. The study focuses on different types of problems arising in the process of transferring responsibility to students in a context of teacher assistance to autonomous…

  6. Characterising Learning Interactions: A Study of University Students Solving Physics Problems in Groups

    ERIC Educational Resources Information Center

    Berge, Maria; Danielsson, Anna T.

    2013-01-01

    The purpose of this article is to explore how a group of four university physics students addressed mechanics problems, in terms of student direction of attention, problem solving strategies and their establishment of and ways of interacting. Adapted from positioning theory, the concepts "positioning" and "storyline" are used to describe and to…

  7. The New Method of Problem Solving in Physics Education by Using SCORM-Compliant Content Package

    ERIC Educational Resources Information Center

    Gonen, Selahattin; Basaran, Bulent

    2008-01-01

    In this article, two basic purposes are presented. First, taking effective feedbacks in the electronic learning environment about the learning level of students at the problem solving which are told in physics lessons and laboratories. Second, providing a possibility for students to repeat the subjects and solved problems by watching and…

  8. Transfer of a Natural Language System for Problem-Solving in Physics to Other Domains.

    ERIC Educational Resources Information Center

    Oberem, Graham E.

    The limited language capability of CAI systems has made it difficult to personalize problem-solving instruction. The intelligent tutoring system, ALBERT, is a problem-solving monitor and coach that has been used with high school and college level physics students for several years; it uses a natural language system to understand kinematics…

  9. An Examination of Physical and Mental Health Problems of the Homeless.

    ERIC Educational Resources Information Center

    Solarz, Andrea; Mowbray, Carol

    Homelessness is a significant social problem in the United States and it has been estimated that there may be as many as 2.5 million homeless people in this country today. For these people, poverty, substance abuse, and harsh living conditions may further contribute to the development of physical and mental health problems. A study was conducted…

  10. Abstract Applets: A Method for Integrating Numerical Problem Solving into the Undergraduate Physics Curriculum

    SciTech Connect

    Peskin, Michael E

    2003-02-13

    In upper-division undergraduate physics courses, it is desirable to give numerical problem-solving exercises integrated naturally into weekly problem sets. I explain a method for doing this that makes use of the built-in class structure of the Java programming language. I also supply a Java class library that can assist instructors in writing programs of this type.

  11. The Identification and Significance of Intuitive and Analytic Problem Solving Approaches Among College Physics Students.

    ERIC Educational Resources Information Center

    Thorsland, Martin N.; Novak, Joseph D.

    A study on individual differences in problem solving approach and their relationships to various learning-related parameters was conducted with a random sample of 25 subjects enrolled in an introductory physics course utilizing instruction through audio-tutorial methods. The subjects received interviews consisting of four problems in energy…

  12. Developing Problem-Solving Skills of Students Taking Introductory Physics via Web-Based Tutorials

    ERIC Educational Resources Information Center

    Singh, Chandralekha; Haileselassie, Daniel

    2010-01-01

    Science teaching and learning can be made both engaging and student-centered using pedagogical, computer-based learning tools. We have developed self-paced interactive problem-solving tutorials for introductory physics. These tutorials can provide guidance and support for a variety of problem-solving techniques, as well as opportunities for…

  13. Physical Health, Mental Health, and Substance Abuse Problems of Shelter Users.

    ERIC Educational Resources Information Center

    Harris, Shirley N.; And Others

    1994-01-01

    Examined physical health of 72 users of homeless shelters, comparing shelter users with mental illness or substance abuse problems with those without these problems. Found that alcohol abusers were significantly more likely to have low blood pressure, symptoms of liver disease, and tuberculosis treatment history. Found no health differences for…

  14. Surveying Turkish high school and university students' attitudes and approaches to physics problem solving

    NASA Astrophysics Data System (ADS)

    Balta, Nuri; Mason, Andrew J.; Singh, Chandralekha

    2016-06-01

    Students' attitudes and approaches to physics problem solving can impact how well they learn physics and how successful they are in solving physics problems. Prior research in the U.S. using a validated Attitude and Approaches to Problem Solving (AAPS) survey suggests that there are major differences between students in introductory physics and astronomy courses and physics experts in terms of their attitudes and approaches to physics problem solving. Here we discuss the validation, administration, and analysis of data for the Turkish version of the AAPS survey for high school and university students in Turkey. After the validation and administration of the Turkish version of the survey, the analysis of the data was conducted by grouping the data by grade level, school type, and gender. While there are no statistically significant differences between the averages of various groups on the survey, overall, the university students in Turkey were more expertlike than vocational high school students. On an item by item basis, there are statistically differences between the averages of the groups on many items. For example, on average, the university students demonstrated less expertlike attitudes about the role of equations and formulas in problem solving, in solving difficult problems, and in knowing when the solution is not correct, whereas they displayed more expertlike attitudes and approaches on items related to metacognition in physics problem solving. A principal component analysis on the data yields item clusters into which the student responses on various survey items can be grouped. A comparison of the responses of the Turkish and American university students enrolled in algebra-based introductory physics courses shows that on more than half of the items, the responses of these two groups were statistically significantly different, with the U.S. students on average responding to the items in a more expertlike manner.

  15. Theoretical-physics approach to selected problems in engineering electromagnetics: Evolutionary optimization and low-dimensional nanostructures

    NASA Astrophysics Data System (ADS)

    Mikki, Said M.

    Although electromagnetism was developed originally as a branch of theoretical physics, the wide spread proliferation of wireless communications and other applications since the turn of the 20th century quickly transformed the field into a well-defined discipline standing by itself as an autonomous part of engineering. This in turn accelerated the growth of both numerical techniques and practical designs aiming all to improve technology. However, one negative drawback was the increasing isolation between the practicality of engineering electromagnetism and the depth and sophistication of the tools that had been developed solely within electromagnetic theory as a branch of theoretical physics. In this dissertation, we propose a new look to engineering electromagnetism from the perspective of theoretical physics. We show that techniques usually associated with abstract physical models in theoretical physics can be successfully employed to enhance our understanding of problems in engineering electromagnetism. Also, such adaptations of theoretical methods allow for new kinds of applications to be invented. This dissertation is organized in two main parts. Part I is concerned with the particle swarm optimization (PSO) method. We first construct a physical theory for the particle swarm optimization and show how this could open the door not just for deeper understanding of the algorithm itself, but also for new techniques to improve the performance of the method when applied to engineering electromagnetics problems. Inspired by the wider perspective derived from physics, we apply quantum effects to the basic (classical) PSO and derive a new general quantum PSO (QPSO) algorithm suitable for engineering electromagnetism. The new method will be shown to be superior to the classical counterpart when applied to some practical problems. A detailed case study that was formulated extensively in our work is the infinitesimal dipole model (IDM), which can simulate arbitrary antennas

  16. Evaluation of ‘OpenCL for FPGA’ for Data Acquisition and Acceleration in High Energy Physics

    NASA Astrophysics Data System (ADS)

    Sridharan, Srikanth

    2015-12-01

    The increase in the data acquisition and processing needs of High Energy Physics experiments has made it more essential to use FPGAs to meet those needs. However harnessing the capabilities of the FPGAs has been hard for anyone but expert FPGA developers. The arrival of OpenCL with the two major FPGA vendors supporting it, offers an easy software-based approach to taking advantage of FPGAs in applications such as High Energy Physics. OpenCL is a language for using heterogeneous architectures in order to accelerate applications. However, FPGAs are capable of far more than acceleration, hence it is interesting to explore if OpenCL can be used to take advantage of FPGAs for more generic applications. To answer these questions, especially in the context of High Energy Physics, two applications, a DAQ module and an acceleration workload, were tested for implementation with OpenCL on FPGAs2. The challenges on using OpenCL for a DAQ application and their solutions, together with the performance of the OpenCL based acceleration are discussed. Many of the design elements needed to realize a DAQ system in OpenCL already exists, mostly as FPGA vendor extensions, but a small number of elements were found to be missing. For acceleration of OpenCL applications, using FPGAs has become as easy as using GPUs. OpenCL has the potential for a massive gain in productivity and ease of use enabling non FPGA experts to design, debug and maintain the code. Also, FPGA power consumption is much lower than other implementations. This paper describes one of the first attempts to explore the use of OpenCL for applications outside the acceleration workloads.

  17. Living with Stigma: Depressed Elderly Persons' Experiences of Physical Health Problems

    PubMed Central

    Holm, Anne Lise; Lyberg, Anne

    2014-01-01

    The aim of this paper is to deepen the understanding of depressed elderly persons' lived experiences of physical health problems. Individual in-depth interviews were conducted with 15 depressed elderly persons who suffer from physical health problems. A hermeneutic analysis was performed, yielding one main theme, living with stigma, and three themes: longing to be taken seriously, being uncertain about whether the pain is physical or mental, and a sense of living in a war zone. The second theme comprised two subthemes, feeling like a stranger and feeling dizzy, while the third had one subtheme: afraid of being helpless and dependent on others. Stigma deprives individuals of their dignity and reinforces destructive patterns of isolation and hopelessness. Nurses should provide information in a sensitive way and try to avoid diagnostic overshadowing. Effective training programmes and procedures need to be developed with more focus on how to handle depressive ill health and physical problems in older people. PMID:25013728

  18. Phenomenology of a realistic accelerating universe using only planck-scale physics

    PubMed

    Albrecht; Skordis

    2000-03-01

    Modern data are showing increasing evidence that the Universe is accelerating. So far, all attempts to account for the acceleration have required some fundamental dimensionless quantities to be extremely small. We show how a class of scalar field models (which may emerge naturally from superstring theory) can account for acceleration which starts in the present epoch with all the potential parameters O(1) in Planck units. PMID:11017213

  19. Epistemic Beliefs about Justification Employed by Physics Students and Faculty in Two Different Problem Contexts

    NASA Astrophysics Data System (ADS)

    Çağlayan Mercan, Fatih

    2012-06-01

    This study examines the epistemic beliefs about justification employed by physics undergraduate and graduate students and faculty in the context of solving a standard classical physics problem and a frontier physics problem. Data were collected by a think-aloud problem solving session followed by a semi-structured interview conducted with 50 participants, 10 participants at freshmen, seniors, masters, PhD, and faculty levels. Seven modes of justification were identified and used for exploring the relationships between each justification mode and problem context, and expertise level. The data showed that justification modes were not mutually exclusive and many respondents combined different modes in their responses in both problem contexts. Success on solving the standard classical physics problem was not related to any of the justification modes and was independent of expertise level. The strength of the association across the problem contexts for the authoritative, rational, and empirical justification modes fell in the medium range and for the modeling justification mode fell in the large range of practical significance. Expertise level was not related with the empirical and religious justification modes. The strength of the association between the expertise level and the authoritative, rational, experiential, and relativistic justification modes fell in the medium range, and the modeling justification mode fell in the large range of practical significance. The results provide support for the importance of context for the epistemic beliefs about justification and are discussed in terms of the implications for teaching and learning science.

  20. Towards a novel laser-driven method of exotic nuclei extraction-acceleration for fundamental physics and technology

    NASA Astrophysics Data System (ADS)

    Nishiuchi, M.; Sakaki, H.; Esirkepov, T. Zh.; Nishio, K.; Pikuz, T. A.; Faenov, A. Ya.; Skobelev, I. Yu.; Orlandi, R.; Pirozhkov, A. S.; Sagisaka, A.; Ogura, K.; Kanasaki, M.; Kiriyama, H.; Fukuda, Y.; Koura, H.; Kando, M.; Yamauchi, T.; Watanabe, Y.; Bulanov, S. V.; Kondo, K.; Imai, K.; Nagamiya, S.

    2016-04-01

    A combination of a petawatt laser and nuclear physics techniques can crucially facilitate the measurement of exotic nuclei properties. With numerical simulations and laser-driven experiments we show prospects for the Laser-driven Exotic Nuclei extraction-acceleration method proposed in [M. Nishiuchi et al., Phys, Plasmas 22, 033107 (2015)]: a femtosecond petawatt laser, irradiating a target bombarded by an external ion beam, extracts from the target and accelerates to few GeV highly charged short-lived heavy exotic nuclei created in the target via nuclear reactions.

  1. On the physics of waves in the solar atmosphere: Wave heating and wind acceleration

    NASA Technical Reports Server (NTRS)

    Musielak, Z. E.

    1994-01-01

    New calculations of the acoustic wave energy fluxes generated in the solar convective zone have been performed. The treatment of convective turbulence in the sun and solar-like stars, in particular, the precise nature of the turbulent power spectrum has been recognized as one of the most important issues in the wave generation problem. Several different functional forms for spatial and temporal spectra have been considered in the literature and differences between the energy fluxes obtained for different forms often exceed two orders of magnitude. The basic criterion for choosing the appropriate spectrum was the maximal efficiency of the wave generation. We have used a different approach based on physical and empirical arguments as well as on some results from numerical simulation of turbulent convection.

  2. Improving physical health monitoring for patients with chronic mental health problems who receive antipsychotic medications

    PubMed Central

    Abdallah, Nihad; Conn, Rory; Latif Marini, Abdel

    2016-01-01

    Physical health monitoring is an integral part of caring for patients with mental health problems. It is proven that serious physical health problems are more common among patients with severe mental health illness (SMI), this monitoring can be challenging and there is a need for improvement. The project aimed at improving the physical health monitoring among patients with SMI who are receiving antipsychotic medications. The improvement process focused on ensuring there is a good communication with general practitioners (GPs) as well as patient's education and education of care home staff. GP letters requesting physical health monitoring were updated; care home staff and patients were given more information about the value of regular physical health monitoring. There was an improvement in patients' engagement with the monitoring and the monitoring done by GPs was more adherent to local and national guidelines and was communicated with the mental health service.

  3. Multi-Physics Demonstration Problem with the SHARP Reactor Simulation Toolkit

    SciTech Connect

    Merzari, E.; Shemon, E. R.; Yu, Y. Q.; Thomas, J. W.; Obabko, A.; Jain, Rajeev; Mahadevan, Vijay; Tautges, Timothy; Solberg, Jerome; Ferencz, Robert Mark; Whitesides, R.

    2015-12-21

    This report describes to employ SHARP to perform a first-of-a-kind analysis of the core radial expansion phenomenon in an SFR. This effort required significant advances in the framework Multi-Physics Demonstration Problem with the SHARP Reactor Simulation Toolkit used to drive the coupled simulations, manipulate the mesh in response to the deformation of the geometry, and generate the necessary modified mesh files. Furthermore, the model geometry is fairly complex, and consistent mesh generation for the three physics modules required significant effort. Fully-integrated simulations of a 7-assembly mini-core test problem have been performed, and the results are presented here. Physics models of a full-core model of the Advanced Burner Test Reactor have also been developed for each of the three physics modules. Standalone results of each of the three physics modules for the ABTR are presented here, which provides a demonstration of the feasibility of the fully-integrated simulation.

  4. Improving physical health monitoring for patients with chronic mental health problems who receive antipsychotic medications.

    PubMed

    Abdallah, Nihad; Conn, Rory; Latif Marini, Abdel

    2016-01-01

    Physical health monitoring is an integral part of caring for patients with mental health problems. It is proven that serious physical health problems are more common among patients with severe mental health illness (SMI), this monitoring can be challenging and there is a need for improvement. The project aimed at improving the physical health monitoring among patients with SMI who are receiving antipsychotic medications. The improvement process focused on ensuring there is a good communication with general practitioners (GPs) as well as patient's education and education of care home staff. GP letters requesting physical health monitoring were updated; care home staff and patients were given more information about the value of regular physical health monitoring. There was an improvement in patients' engagement with the monitoring and the monitoring done by GPs was more adherent to local and national guidelines and was communicated with the mental health service. PMID:27559474

  5. An exact algorithm for the maximum clique problem with accelerated pruning

    SciTech Connect

    Pardalos, P.; Gibbons, L.; Hearn, D.

    1994-12-31

    We present an exact partial enumerative algorithm for the maximum clique problem. The pruning device used is derived from graph colorings. Pruning of the search tree is accomplished not only by the number of colors used to color a tree subproblem but also by using information gained in the process of coloring. This leads to increased pruning which translates into improved computational performance. Experimental results on test problems are presented.

  6. Solving Large-Scale Computational Problems Using Insights from Statistical Physics

    SciTech Connect

    Selman, Bart

    2012-02-29

    Many challenging problems in computer science and related fields can be formulated as constraint satisfaction problems. Such problems consist of a set of discrete variables and a set of constraints between those variables, and represent a general class of so-called NP-complete problems. The goal is to find a value assignment to the variables that satisfies all constraints, generally requiring a search through and exponentially large space of variable-value assignments. Models for disordered systems, as studied in statistical physics, can provide important new insights into the nature of constraint satisfaction problems. Recently, work in this area has resulted in the discovery of a new method for solving such problems, called the survey propagation (SP) method. With SP, we can solve problems with millions of variables and constraints, an improvement of two orders of magnitude over previous methods.

  7. ADHD as risk factor for early onset and heightened adult problem severity of illicit substance use: An Accelerated Gateway Model

    PubMed Central

    Dunne, Eugene M.; Hearn, Lauren E.; Rose, Jonathan; Latimer, William W.

    2014-01-01

    The primary aims of the present study were to assess ADHD history as a risk factor for earlier initiation and current use of licit and illicit substances among a sample of drug using adults. It was hypothesized that ADHD history would accelerate the Gateway Theory of drug use. Participants included 941 drug-using African American and Caucasian individuals in Baltimore, Maryland. The sample consisted of 124 (13.2%) participants who reported a history of ADHD and 817 (86.8%) who reported no history of ADHD. The accelerated gateway hypothesis was supported, as a history of self-reported ADHD was significantly associated with younger ages of initiation for alcohol, cigarettes, marijuana, and cocaine use. Participants with a history of ADHD were also more likely to engage in recent HIV-risk behavior, such as injection drug use and needle sharing. This study provides compelling data in support of an accelerated gateway model for substance use related to ADHD history and increased problem severity in adulthood. Targeted substance use prevention and intervention may be beneficial for those with ADHD. PMID:25123341

  8. J-PAS: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Dupke, Renato A.; Benitez, Narciso; Moles, Mariano; Sodre, Laerte; Irwin, Jimmy; J-PAS Collaboration

    2016-01-01

    The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Astrophysical Observatory in Spain with a dedicated 2.5m telescope and a 4.7deg^2 camera with 1.2Gpix. Starting in 2016, J-PAS will observe 8600 deg^2 of the Northern Sky and measure 0.003(1+z) precision photometric redshifts for nearly 1E08 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~14 Gpc^3 up to z = 1.3. J-PAS will also detect and measure the mass of more than a hundred thousand galaxy clusters, setting constrains on Dark Energy which rival those obtained from BAO measurements.The key to the J-PAS potential is its innovative approach the combination of 54 145°A filters, placed 100°A apart, and a multi-degree field of view (FOV) which makes it a powerful "redshift machine", with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. Moreover, since the J-PAS camera is equivalent to a very large, 4.7deg^2 "IFU", it will produce a time-resolved, 3D image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby Universe and the study of resolved stellar populations. J-PAS will have a lasting legacy value in many areas of Astrophysics, serving as a fundamental dataset for future Cosmological projects.Here, we present the overall description, status and scientific potential of the survey.

  9. J-PAS: The Javalambre-Physics of the Accelerating Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Dupke, Renato a.; Benitez, Narciso; Moles, Mariano; Sodre, Laerte; J-PAS Collaboration

    2015-08-01

    The Javalambre-Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Astrophysical Observatory in Spain with a dedicated 2.5m telescope and a 4.7deg^2 camera with 1.2Gpix. Starting in 2016, J-PAS will observe 8600 deg^2 of the Northern Sky and measure 0.003(1+z) precision photometric redshifts for nearly 1E08 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ~14 Gpc^3 up to z = 1.3. J-PAS will also detect and measure the mass of more than a hundred thousand galaxy clusters, setting constrains on Dark Energy which rival those obtained from BAO measurements.The key to the J-PAS potential is its innovative approach the combination of 54 145°A filters, placed 100°A apart, and a multi-degree field of view (FOV) which makes it a powerful “redshift machine”, with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. Moreover, since the J-PAS camera is equivalent to a very large, 4.7deg^2 “IFU”, it will produce a time-resolved, 3D image of the Northern Sky with a very wide range of Astrophysical applications in Galaxy Evolution, the nearby Universe and the study of resolved stellar populations. J-PAS will have a lasting legacy value in many areas of Astrophysics, serving as a fundamental dataset for future Cosmological projects.Here, we present the overall description, status and scientific potential of the survey.

  10. The impact of anticipated stigma on psychological and physical health problems in the unemployed group

    PubMed Central

    O’Donnell, Aisling T.; Corrigan, Fiona; Gallagher, Stephen

    2015-01-01

    Previous research has demonstrated that the unemployed suffer increased psychological and physical health problems compared to their employed counterparts. Further, unemployment leads to an unwanted new social identity that is stigmatizing, and stigma is known to be a stressor causing psychological and physical health problems. However, it is not yet known whether being stigmatized as an unemployed group member is associated with psychological and physical health in this group. The current study tested the impact of anticipated stigma (AS) on psychological distress (PD) and physical health problems, operationalized as somatic symptoms (SSs), in a volunteer sample of unemployed people. Results revealed that AS had a direct effect on both PD and SSs, such that greater AS significantly predicted higher levels of both. Moreover, the direct effect on SSs became non-significant when PD was taken into account. Thus, to the extent that unemployed participants anticipated experiencing greater stigma, they also reported increased PD, and this PD predicted increased SSs. Our findings complement and extend the existing literature on the relationships between stigmatized identities, PD and physical health problems, particularly in relation to the unemployed group. This group is important to consider both theoretically, given the unwanted and transient nature of the identity compared to other stigmatized identities, but also practically, as the findings indicate a need to orient to the perceived valence of the unemployed identity and its effects on psychological and physical health. PMID:26379589

  11. LCODE: A parallel quasistatic code for computationally heavy problems of plasma wakefield acceleration

    NASA Astrophysics Data System (ADS)

    Sosedkin, A. P.; Lotov, K. V.

    2016-09-01

    LCODE is a freely distributed quasistatic 2D3V code for simulating plasma wakefield acceleration, mainly specialized at resource-efficient studies of long-term propagation of ultrarelativistic particle beams in plasmas. The beam is modeled with fully relativistic macro-particles in a simulation window copropagating with the light velocity; the plasma can be simulated with either kinetic or fluid model. Several techniques are used to obtain exceptional numerical stability and precision while maintaining high resource efficiency, enabling LCODE to simulate the evolution of long particle beams over long propagation distances even on a laptop. A recent upgrade enabled LCODE to perform the calculations in parallel. A pipeline of several LCODE processes communicating via MPI (Message-Passing Interface) is capable of executing multiple consecutive time steps of the simulation in a single pass. This approach can speed up the calculations by hundreds of times.

  12. Development and validation of a physics problem-solving assessment rubric

    NASA Astrophysics Data System (ADS)

    Docktor, Jennifer Lynn

    Problem solving is a complex process that is important for everyday life and crucial for learning physics. Although there is a great deal of effort to improve student problem solving throughout the educational system, there is no standard way to evaluate written problem solving that is valid, reliable, and easy to use. Most tests of problem solving performance given in the classroom focus on the correctness of the end result or partial results rather than the quality of the procedures and reasoning leading to the result, which gives an inadequate description of a student's skills. A more detailed and meaningful measure is necessary if different curricular materials or pedagogies are to be compared. This measurement tool could also allow instructors to diagnose student difficulties and focus their coaching. It is important that the instrument be applicable to any problem solving format used by a student and to a range of problem types and topics typically used by instructors. Typically complex processes such as problem solving are assessed by using a rubric, which divides a skill into multiple quasi-independent categories and defines criteria to attain a score in each. This dissertation describes the development of a problem solving rubric for the purpose of assessing written solutions to physics problems and presents evidence for the validity, reliability, and utility of score interpretations on the instrument.

  13. Physics Problems Based on Up-to-Date Science and Technology.

    NASA Astrophysics Data System (ADS)

    Folan, Lorcan M.; Tsifrinovich, Vladimir I.

    2007-03-01

    We observe a huge chasm between up-to-date science and undergraduate education. The result of this chasm is that current student interest in undergraduate science is low. Consequently, students who are graduating from college are often unable to take advantage of the many opportunities offered by science and technology. Cutting edge science and technology frequently use the methods learned in undergraduate courses, but up-to-date applications are not normally used as examples or for problems in undergraduate courses. There are many physics problems which contain information about the latest achievements in science and technology. But typically, the level of these problems is too advanced for undergraduates. We created physics problems for undergraduate science and engineering students, which are based on the latest achievements in science and technology. These problems have been successfully used in our courses at the Polytechnic University in New York. We believe that university faculty may suggest such problems in order to provide information about the frontiers of science and technological, demonstrate the importance of undergraduate physics in solving contemporary problems and raise the interest of talented students in science. From the other side, our approach may be considered an indirect way for advertising advanced technologies, which undergraduate students and, even more important, future college graduates could use in their working lives.

  14. Nonlinear Krylov acceleration applied to a discrete ordinates formulation of the k-eigenvalue problem

    NASA Astrophysics Data System (ADS)

    Calef, Matthew T.; Fichtl, Erin D.; Warsa, James S.; Berndt, Markus; Carlson, Neil N.

    2013-04-01

    We compare a variant of Anderson Mixing with the Jacobian-Free Newton-Krylov and Broyden methods applied to an instance of the k-eigenvalue formulation of the linear Boltzmann transport equation. We present evidence that one variant of Anderson Mixing finds solutions in the fewest number of iterations. We examine and strengthen theoretical results of Anderson Mixing applied to linear problems.

  15. Child and Family Psychiatric and Psychological Factors Associated With Child Physical Health Problems

    PubMed Central

    Feldman, Jonathan M.; Ortega, Alexander N.; Koinis-Mitchell, Daphne; Kuo, Alice A.; Canino, Glorisa

    2010-01-01

    To examine associations among Puerto Rican children's physical health problems and children's internalizing disorders, parental psychopathology and acculturative stress, and family factors. A population-based probability sample of 2491 Puerto Rican children, aged between 5 and 13 years, and caregivers from the South Bronx and the U.S. Commonwealth of Puerto Rico participated in this study. The parent version of the Diagnostic Interview Schedule for Children-IV was used to assess children's internalizing disorders. Children's anxiety disorders, parental psychopathology, and acculturative stress were associated with childhood asthma, abdominal pain, and headaches. Children's depressive disorders, maternal acceptance, and family functioning were associated with abdominal pain and headaches. Parents of children living in Puerto Rico were more likely to report physical health problems in their children than in the Bronx. Children's internalizing disorders, parental psychopathology, and acculturative stress may be important areas to target among Puerto Rican children with physical health problems. PMID:20386256

  16. Accelerator System Model (ASM) user manual with physics and engineering model documentation. ASM version 1.0

    SciTech Connect

    1993-07-01

    The Accelerator System Model (ASM) is a computer program developed to model proton radiofrequency accelerators and to carry out system level trade studies. The ASM FORTRAN subroutines are incorporated into an intuitive graphical user interface which provides for the {open_quotes}construction{close_quotes} of the accelerator in a window on the computer screen. The interface is based on the Shell for Particle Accelerator Related Codes (SPARC) software technology written for the Macintosh operating system in the C programming language. This User Manual describes the operation and use of the ASM application within the SPARC interface. The Appendix provides a detailed description of the physics and engineering models used in ASM. ASM Version 1.0 is joint project of G. H. Gillespie Associates, Inc. and the Accelerator Technology (AT) Division of the Los Alamos National Laboratory. Neither the ASM Version 1.0 software nor this ASM Documentation may be reproduced without the expressed written consent of both the Los Alamos National Laboratory and G. H. Gillespie Associates, Inc.

  17. Towards an understanding of how students use representations in physics problem solving

    NASA Astrophysics Data System (ADS)

    Kohl, Patrick Brian

    2007-12-01

    Skill with different representations and multiple representations is highly valued in physics, and prior work has shown that novice physics students can struggle with the representations typically used in solving physics problems. There exists work in PER examining student use of representations and multiple representations, but there have been no comprehensive attempts to understand what factors influence how introductory students succeed or fail in using representations in physics. This thesis is such an attempt, and is organized around four main goals and results. First, we establish that representation is a major factor in student performance, and uncover some of the mechanisms by which representation can affect performance, including representation-dependent cueing. Second, we study the effect of different instructional environments on student learning of multiple representation use during problem solving, and find that courses that are rich in representations can have significant impacts on student skills. Third, we evaluate the role of meta-representational skills in solving physics problems at the introductory level, and find that the meta-representational abilities that we test for in our studies are poorly developed in introductory students. Fourth, we characterize the differences in representation use between expert and novice physics problem solvers, and note that the major differences appear not to lie in whether representations are used, but in how they are used. With these results in hand, we introduce a model of student use of representations during physics problem solving. This model consists of a set of practical heuristics plus an analysis framework adapted from cultural-constructivist theory. We demonstrate that this model can be useful in understanding and synthesizing our results, and we discuss the instructional implications of our findings.

  18. Is conceptual understanding compromised by a problem-solving emphasis in an introductory physics course?

    NASA Astrophysics Data System (ADS)

    Ridenour, J.; Feldman, G.; Teodorescu, R.; Medsker, L.; Benmouna, N.

    2013-01-01

    Developing competency in problem solving and enhancing conceptual understanding are primary objectives in introductory physics, and many techniques and tools are available to help instructors achieve them. Pedagogically, we use an easy-to-implement intervention, the ACCESS protocol, to develop and assess problem-solving skills in our SCALE-UP classroom environment for algebra-based physics. Based on our research and teaching experience, an important question has emerged: while primarily targeting improvements in problem-solving and cognitive development, is it necessary that conceptual understanding be compromised? To address this question, we gathered and analyzed information about student abilities, backgrounds, and instructional preferences. We report on our progress and give insights into matching the instructional tools to student profiles in order to achieve optimal learning in group-based active learning. The ultimate goal of our work is to integrate individual student learning needs into a pedagogy that moves students closer to expert-like status in problem solving.

  19. Developmental and physical-fitness associations with gross motor coordination problems in Peruvian children.

    PubMed

    de Chaves, Raquel Nichele; Bustamante Valdívia, Alcibíades; Nevill, Alan; Freitas, Duarte; Tani, Go; Katzmarzyk, Peter T; Maia, José António Ribeiro

    2016-01-01

    The aims of this cross-sectional study were to examine the developmental characteristics (biological maturation and body size) associated with gross motor coordination problems in 5193 Peruvian children (2787 girls) aged 6-14 years from different geographical locations, and to investigate how the probability that children suffer with gross motor coordination problems varies with physical fitness. Children with gross motor coordination problems were more likely to have lower flexibility and explosive strength levels, having adjusted for age, sex, maturation and study site. Older children were more likely to suffer from gross motor coordination problems, as were those with greater body mass index. However, more mature children were less likely to have gross motor coordination problems, although children who live at sea level or at high altitude were more likely to suffer from gross motor coordination problems than children living in the jungle. Our results provide evidence that children and adolescents with lower physical fitness are more likely to have gross motor coordination difficulties. The identification of youths with gross motor coordination problems and providing them with effective intervention programs is an important priority in order to overcome such developmental problems, and help to improve their general health status. PMID:26871464

  20. Physical conditions for conducting radiobiological experiments in beams of accelerated particles with high linear energy transfer

    NASA Technical Reports Server (NTRS)

    Kudryashov, Y. I.; Marennyy, A. M.; Popov, V. I.; Aykhorn, K.; Ertsgreber, G.

    1974-01-01

    The design and construction of an accelerator to conduct radiobiological experiments is reported that uses aluminum filters to control the accelerated ion beam while preserving its stability, and a vacuum chamber to conduct the ion beam with the help of a collector through a lavsan exit port to the target. Depth distribution of the absorbed dose from a monodirectional ion beam is practically completely represented by the change in the energy spectrum of the biological object.

  1. Solving the Accelerator-Condenser Coupling Problem in a Nanosecond Dynamic Transmission Electron Microscope

    SciTech Connect

    Reed, B W; LaGrange, T; Shuttlesworth, R M; Gibson, D J; Campbell, G H; Browning, N D

    2009-12-29

    We describe a modification to a transmission electron microscope (TEM) that allows it to briefly (using a pulsed-laser-driven photocathode) operate at currents in excess of 10 mA while keeping the effects of condenser lens aberrations to a minimum. This modification allows real-space imaging of material microstructure with a resolution of order 10 nm over regions several {micro}m across with an exposure time of 15 ns. This is more than 6 orders of magnitude faster than typical video-rate TEM imaging. The key is the addition of a weak magnetic lens to couple the large-diameter high-current beam exiting the accelerator into the acceptance aperture of a conventional TEM condenser lens system. We show that the performance of the system is essentially consistent with models derived from ray tracing and finite element simulations. The instrument can also be operated as a conventional TEM by using the electron gun in a thermionic mode. The modification enables very high electron current densities in {micro}m-sized areas and could also be used in a non-pulsed system for high-throughput imaging and analytical TEM.

  2. Solving the accelerator-condenser coupling problem in a nanosecond dynamic transmission electron microscope.

    PubMed

    Reed, B W; LaGrange, T; Shuttlesworth, R M; Gibson, D J; Campbell, G H; Browning, N D

    2010-05-01

    We describe a modification to a transmission electron microscope (TEM) that allows it to briefly (using a pulsed-laser-driven photocathode) operate at currents in excess of 10 mA while keeping the effects of condenser lens aberrations to a minimum. This modification allows real-space imaging of material microstructure with a resolution of order 10 nm over regions several microm across with an exposure time of 15 ns. This is more than six orders of magnitude faster than typical video-rate TEM imaging. The key is the addition of a weak magnetic lens to couple the large-diameter high-current beam exiting the accelerator into the acceptance aperture of a conventional TEM condenser lens system. We show that the performance of the system is essentially consistent with models derived from ray tracing and finite element simulations. The instrument can also be operated as a conventional TEM by using the electron gun in a thermionic mode. The modification enables very high electron current densities in microm-sized areas and could also be used in a nonpulsed system for high-throughput imaging and analytical TEM. PMID:20515144

  3. Can Accelerators Accelerate Learning?

    NASA Astrophysics Data System (ADS)

    Santos, A. C. F.; Fonseca, P.; Coelho, L. F. S.

    2009-03-01

    The 'Young Talented' education program developed by the Brazilian State Funding Agency (FAPERJ) [1] makes it possible for high-schools students from public high schools to perform activities in scientific laboratories. In the Atomic and Molecular Physics Laboratory at Federal University of Rio de Janeiro (UFRJ), the students are confronted with modern research tools like the 1.7 MV ion accelerator. Being a user-friendly machine, the accelerator is easily manageable by the students, who can perform simple hands-on activities, stimulating interest in physics, and getting the students close to modern laboratory techniques.

  4. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    NASA Astrophysics Data System (ADS)

    Stygar, W. A.; Awe, T. J.; Bailey, J. E.; Bennett, N. L.; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; Genoni, T. C.; Gomez, M. R.; Greiser, G. W.; Gruner, F. R.; Herrmann, M. C.; Hutsel, B. T.; Jennings, C. A.; Jobe, D. O.; Jones, B. M.; Jones, M. C.; Jones, P. A.; Knapp, P. F.; Lash, J. S.; LeChien, K. R.; Leckbee, J. J.; Leeper, R. J.; Lewis, S. A.; Long, F. W.; Lucero, D. J.; Madrid, E. A.; Martin, M. R.; Matzen, M. K.; Mazarakis, M. G.; McBride, R. D.; McKee, G. R.; Miller, C. L.; Moore, J. K.; Mostrom, C. B.; Mulville, T. D.; Peterson, K. J.; Porter, J. L.; Reisman, D. B.; Rochau, G. A.; Rochau, G. E.; Rose, D. V.; Rovang, D. C.; Savage, M. E.; Sceiford, M. E.; Schmit, P. F.; Schneider, R. F.; Schwarz, J.; Sefkow, A. B.; Sinars, D. B.; Slutz, S. A.; Spielman, R. B.; Stoltzfus, B. S.; Thoma, C.; Vesey, R. A.; Wakeland, P. E.; Welch, D. R.; Wisher, M. L.; Woodworth, J. R.

    2015-11-01

    We have developed conceptual designs of two petawatt-class pulsed-power accelerators: Z 300 and Z 800. The designs are based on an accelerator architecture that is founded on two concepts: single-stage electrical-pulse compression and impedance matching [Phys. Rev. ST Accel. Beams 10, 030401 (2007)]. The prime power source of each machine consists of 90 linear-transformer-driver (LTD) modules. Each module comprises LTD cavities connected electrically in series, each of which is powered by 5-GW LTD bricks connected electrically in parallel. (A brick comprises a single switch and two capacitors in series.) Six water-insulated radial-transmission-line impedance transformers transport the power generated by the modules to a six-level vacuum-insulator stack. The stack serves as the accelerator's water-vacuum interface. The stack is connected to six conical outer magnetically insulated vacuum transmission lines (MITLs), which are joined in parallel at a 10-cm radius by a triple-post-hole vacuum convolute. The convolute sums the electrical currents at the outputs of the six outer MITLs, and delivers the combined current to a single short inner MITL. The inner MITL transmits the combined current to the accelerator's physics-package load. Z 300 is 35 m in diameter and stores 48 MJ of electrical energy in its LTD capacitors. The accelerator generates 320 TW of electrical power at the output of the LTD system, and delivers 48 MA in 154 ns to a magnetized-liner inertial-fusion (MagLIF) target [Phys. Plasmas 17, 056303 (2010)]. The peak electrical power at the MagLIF target is 870 TW, which is the highest power throughout the accelerator. Power amplification is accomplished by the centrally located vacuum section, which serves as an intermediate inductive-energy-storage device. The principal goal of Z 300 is to achieve thermonuclear ignition; i.e., a fusion yield that exceeds the energy transmitted by the accelerator to the liner. 2D magnetohydrodynamic (MHD) simulations

  5. Socialization patterns and sexual problems of the institutionalized chronically ill and physically disabled.

    PubMed

    Paradowski, W

    1977-02-01

    A post hoc survey of spontaneous remarks and actions bearing on social and sexual adjustment was done on 155 long-term physically disabled patients in a chronic-care hospital. Thirty-five percent were found to be involved in an active dyadic relationship; the great majority of these were between unmarried patients within the hospital. The remaining 65% were socially unattached. A large proportion of both socially attached and socially unattached patients acknowledged achieving some sort of sexual outlet. The importance of opportunity for sexual activity is discussed as it relates to traditional methods for dealing with the problems of personal confidence and physical competence of the physically disabled. PMID:138408

  6. The Systemic Approach to Technological Education: Effects of Transferred Learning in Resolving a Physics Problem

    ERIC Educational Resources Information Center

    Andreucci, Colette; Chatoney, Marjolaine; Ginestie, Jacques

    2012-01-01

    The purpose of this study is to verify whether pupils (15-16 years old) who have received technology education on a systemic approach of industrial systems, are better than other pupils (of the same age but from other academic domains such as literary ones or ones that are economics-based) at solving physical science problems which involve…

  7. Problem-Based Labs and Group Projects in an Introductory University Physics Course

    ERIC Educational Resources Information Center

    Kohnle, Antje; Brown, C. Tom A.; Rae, Cameron F.; Sinclair, Bruce D.

    2012-01-01

    This article describes problem-based labs and analytical and computational project work we have been running at the University of St Andrews in an introductory physics course since 2008/2009. We have found the choice of topics, scaffolding of the process, timing in the year and facilitator guidance decisive for the success of these activities.…

  8. Tarzan's Dilemma: A Challenging Problem for Introductory Physics Students

    ERIC Educational Resources Information Center

    Rave, Matthew; Sayers, Marcus

    2013-01-01

    The following kinematics problem was given to several students as a project in conjunction with a first-semester calculus-based physics course. The students were asked to keep a journal of all their work and were encouraged to keep even their scrap paper. The goal of the project was to expose the students to the process of doing theoretical…

  9. How Partner Gender Influences Female Students' Problem Solving in Physics Education

    ERIC Educational Resources Information Center

    Ding, N.; Harskamp, E.

    2006-01-01

    Research has shown that female students cannot profit as much as male students can from cooperative learning in physics, especially in mixed-gender dyads. This study has explored the influence of partner gender on female students' learning achievement, interaction and the problem-solving process during cooperative learning. In Shanghai, a total of…

  10. An Investigation into the Effectiveness of Problem-Based Learning in a Physical Chemistry Laboratory Course

    ERIC Educational Resources Information Center

    Gurses, Ahmet; Acikyildiz, Metin; Dogar, Cetin; Sozbilir, Mustafa

    2007-01-01

    The aim of this study was to investigate the effectiveness of a problem-based learning (PBL) approach in a physical chemistry laboratory course. The parameters investigated were students' attitudes towards a chemistry laboratory course, scientific process skills of students and their academic achievement. The design of the study was one group…

  11. Time to Completion of Web-Based Physics Problems with Tutoring

    ERIC Educational Resources Information Center

    Warnakulasooriya, Rasil; Palazzo, David J.; Pritchard, David E.

    2007-01-01

    We studied students performing a complex learning task, that of solving multipart physics problems with interactive tutoring on the web. We extracted the rate of completion and fraction completed as a function of time on task by retrospectively analyzing the log of student-tutor interactions. There was a spontaneous division of students into three…

  12. Patterns of Multiple Representation Use by Experts and Novices during Physics Problem Solving

    ERIC Educational Resources Information Center

    Kohl, Patrick B.; Finkelstein, Noah D.

    2008-01-01

    It is generally believed that students should use multiple representations in solving certain physics problems, and earlier work in PER has begun to outline how experts and novices differ in their use of multiple representations. In this study, we build on this foundation by interviewing expert and novice physicists as they solve two types of…

  13. Solving Physics Problems: The Conceptions and Practice of an Experienced Teacher and an Inexperienced Teacher

    ERIC Educational Resources Information Center

    Freitas, Isabel M.; Jimenez, Roque; Mellado, Vicente

    2004-01-01

    The results are described of two case studies on the conceptions and classroom practice of two Portuguese physics and chemistry teachers on the role of problem solving in the teaching/learning of science. One of these teachers was a novice and the other had about 20 years of teaching experience. The data were obtained from a questionnaire, a…

  14. Problem-Based Learning in a Physical Therapy Program and Subsequent Clinical Practice: The Practitioners' Perspectives.

    ERIC Educational Resources Information Center

    Wilson, Stanley H.; Gallagher, Jo D.; Elbaum, Leonard; Smith, Douglas H.

    This study examined the perspectives of three graduates of a problem-based learning (PBL) physical therapy (PT) program about their clinical practice. Researchers used qualitative methods of observation, interview, and journaling to gather the data. Three sessions of audiotaped interviews and two observation sessions were conducted with the three…

  15. Students' Perspectives on Problem-Based Learning in a Transitional Doctorate of Physical Therapy Program

    ERIC Educational Resources Information Center

    Larin, Helene M.; Buccieri, Kathleen M.; Wessel, Jean

    2010-01-01

    Doctor of physical therapy (DPT) graduates are expected to be competent in professional behaviors, communication, critical inquiry, clinical decision making, and evidence-based practice. The purpose of this qualitative study was to describe the experience of students enrolled in a single, problem-based learning (PBL) course within a conventional…

  16. Junior High School Physics: Using a Qualitative Strategy for Successful Problem Solving

    ERIC Educational Resources Information Center

    Mualem, Roni; Eylon, Bat Sheva

    2010-01-01

    Students at the junior high school (JHS) level often cannot use their knowledge of physics for explaining and predicting phenomena. We claim that this difficulty stems from the fact that explanations are multi-step reasoning tasks, and students often lack the qualitative problem-solving strategies needed to guide them. This article describes a new…

  17. Developmental Trajectories of Chinese Children's Relational and Physical Aggression: Associations with Social-Psychological Adjustment Problems

    ERIC Educational Resources Information Center

    Kawabata, Yoshito; Tseng, Wan-Ling; Murray-Close, Dianna; Crick, Nicki R.

    2012-01-01

    The purpose of this short-term longitudinal study was to examine Chinese children's trajectories of physical and relational aggression and their association with social-psychological adjustment problems (i.e., depressive symptoms and delinquency) and gender. Fourth and fifth grade children in Taiwan (n = 739, age 9-11) were followed across 1 year.…

  18. Problems Encountered by Religious Vocational Secondary School and Other Secondary School Students in Physical Education and Sports Activities

    ERIC Educational Resources Information Center

    Bar, Mustafa; Yaman, Menzure Sibel; Hergüner, Gülten

    2016-01-01

    The study aimed to determine problems encountered by Religious Vocational Secondary School and other Secondary School students in physical education and sports activities and to compare these problems according to school type and gender. A questionnaire named "Problems encountered in attending to physical education and sports activities"…

  19. How Does Visual Attention Differ Between Experts and Novices on Physics Problems?

    NASA Astrophysics Data System (ADS)

    Carmichael, Adrian; Larson, Adam; Gire, Elizabeth; Loschky, Lester; Rebello, N. Sanjay

    2010-10-01

    Research in many disciplines has used eye-tracking technology to investigate the differences in the visual attention of experts and novices. For example, it has been shown that experts in art and chess spend more time than novices looking at relevant information. Thus, it may be helpful to give novices more direct insight into the way experts allocate their visual attention, for example using attentional cueing techniques. However, not much is known about how experts allocate their attention on physics problems. More specifically, we look at physics problems where the critical information needed to answer the problem is contained in a diagram. This study uses eye movements to investigate how the allocation of visual attention differs between experts and novices on these types of physics problems. We find that in several problems tested, those who answered a question correctly spend more time looking at thematically relevant areas while those who answer incorrectly spend more time looking at perceptually salient areas of the diagram.

  20. Conceptual design project: Accelerator complex for nuclear physics studies and boron neutron capture therapy application at the Yerevan Physics Institute (YerPhI) Yerevan, Armenia

    NASA Astrophysics Data System (ADS)

    Avagyan, R. H.; Kerobyan, I. A.

    2015-07-01

    The final goal of the proposed project is the creation of a Complex of Accelerator Facilities at the Yerevan Physics Institute (CAF YerPhI) for nuclear physics basic researches, as well as for applied programs including boron neutron capture therapy (BNCT). The CAF will include the following facilities: Cyclotron C70, heavy material (uranium) target/ion source, mass-separator, LINAC1 (0.15-1.5 MeV/u) and LINAC2 (1.5-10 MeV/u). The delivered by C70 proton beams with energy 70 MeV will be used for investigations in the field of basic nuclear physics and with energy 30 MeV for use in applications.

  1. A QR accelerated volume-to-surface boundary condition for finite element solution of eddy current problems

    SciTech Connect

    White, D; Fasenfest, B; Rieben, R; Stowell, M

    2006-09-08

    We are concerned with the solution of time-dependent electromagnetic eddy current problems using a finite element formulation on three-dimensional unstructured meshes. We allow for multiple conducting regions, and our goal is to develop an efficient computational method that does not require a computational mesh of the air/vacuum regions. This requires a sophisticated global boundary condition specifying the total fields on the conductor boundaries. We propose a Biot-Savart law based volume-to-surface boundary condition to meet this requirement. This Biot-Savart approach is demonstrated to be very accurate. In addition, this approach can be accelerated via a low-rank QR approximation of the discretized Biot-Savart law.

  2. A Treasure Trove of Physics from a Common Source-Automobile Acceleration Data

    NASA Astrophysics Data System (ADS)

    Graney, Christopher M.

    2005-11-01

    What is better than interesting, challenging physics with good data free for the taking to which everyone can relate? That's what is available to anyone who digs into the reams of automobile performance tests that have been available in popular magazines since the 1950s. Opportunities to do and teach interesting physics abound, as evidenced by the frequent appearance of "physics of cars" articles in The Physics Teacher.1-6

  3. Accelerator searches for new physics in the context of dark matter

    NASA Astrophysics Data System (ADS)

    Lowette, Steven

    2016-05-01

    A review is given of the current status of searches for dark matter at accelerators. Particular emphasis is put on generic searches for direct production of dark matter at the LHC during its first run, and on the recent developments for the interpretation of the results, where the models using an effective field theory approach are now being complemented with more generic interpretations in the context of simplified models. Furthermore, results are reported briefly for searches for dark matter at the LHC in the context of supersymmetry, as well as for non-LHC accelerator searches.

  4. Chaotic dynamics in accelerator physics. [Dept. of Astrophysical, Planetary, and Atmospheric Sciences, Univ. of Colorado, Boulder

    SciTech Connect

    Cary, J.R.

    1992-11-30

    Substantial progress was in several areas of accelerator dynamics. For developing understanding of longitudinal adiabatic dynamics, and for creating efficiency enhancements of recirculating free-electron lasers, was substantially completed. A computer code for analyzing the critical KAM tori that bound the dynamic aperture in circular machines was developed. Studies of modes that arise due to the interaction of coating beams with a narrow-spectrum impedance have begun. During this research educational and research ties with the accelerator community at large have been strengthened.

  5. Thinking in terms of sensors: personification of self as an object in physics problem solving

    NASA Astrophysics Data System (ADS)

    Tabor-Morris, A. E.

    2015-03-01

    How can physics teachers help students develop consistent problem solving techniques for both simple and complicated physics problems, such as those that encompass objects undergoing multiple forces (mechanical or electrical) as individually portrayed in free-body diagrams and/or phenomenon involving multiple objects, such as Doppler effect reflection applications in echoes and ultrasonic cardiac monitoring for sound, or police radar for light? These problems can confuse novice physics students, and to sort out problem parts, the suggestion is made here to guide the student to personify self as the object in question, that is, to imagine oneself as the object undergoing outside influences such as forces and then qualify and quantify those for the problem at hand. This personification does NOT, as according to the three traditional definitions of the term (animism, anthropomorphism and teleology), empower the object to act, but instead just to detect its environment. By having students use their imagination to put themselves in the place of the object, they can ‘sense’ the influences the object is experiencing to analyze these individually, hopefully reducing the student’s feeling of being overwhelmed with information, and also imbuing the student with a sense of having experienced the situation. This can be especially useful in problems that involve both multiple forces AND multiple objects (for example, Atwood’s machine), since objects acted upon need to be considered separately and consecutively, with the idea that one cannot be two objects at once. This personification technique, documented to have been used by both Einstein and Feynman, is recommended here for secondary-school teen and university-level adult learners with discussions on specific physics and astronomy classroom strategies.

  6. Evaluating Heat Pipe Performance in 1/6 g Acceleration: Problems and Prospects

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; McCollum, Timothy A.; Gibson, Marc A.; Sanzi, James L.; Sechkar, Edward A.

    2011-01-01

    Heat pipes composed of titanium and water are being considered for use in the heat rejection system of a fission power system option for lunar exploration. Placed vertically on the lunar surface, the heat pipes would operate as thermosyphons in the 1/6 g environment. The design of thermosyphons for such an application is determined, in part, by the flooding limit. Flooding is composed of two components, the thickness of the fluid film on the walls of the thermosyphon and the interaction of the fluid flow with the concurrent vapor counter flow. Both the fluid thickness contribution and interfacial shear contribution are inversely proportional to gravity. Hence, evaluating the performance of a thermosyphon in a 1 g environment on Earth may inadvertently lead to overestimating the performance of the same thermosyphon as experienced in the 1/6 g environment on the moon. Several concepts of varying complexity have been proposed for evaluating thermosyphon performance in reduced gravity, ranging from tilting the thermosyphons on Earth based on a cosine function, to flying heat pipes on a low-g aircraft. This paper summarizes the problems and prospects for evaluating thermosyphon performance in 1/6 g.

  7. Student representational competence and self-assessment when solving physics problems

    NASA Astrophysics Data System (ADS)

    Kohl, Patrick B.; Finkelstein, Noah D.

    2005-12-01

    Student success in solving physics problems is related to the representational format of the problem. We study student representational competence in two large-lecture algebra-based introductory university physics courses with approximately 600 participants total. We examined student performance on homework problems given in four different representational formats (mathematical, pictorial, graphical, verbal), with problem statements as close to isomorphic as possible. In addition to the homeworks, we examine students’ assessment of representations by providing follow-up quizzes in which they chose between various problem formats. As a control, some parts of the classes were assigned a random-format follow-up quiz. We find that there are statistically significant performance differences between different representations of nearly isomorphic statements of quiz and homework problems. We also find that allowing students to choose which representational format they use improves student performance under some circumstances and degrades it in others. Notably, one of the two courses studied shows much greater performance differences between the groups that received a choice of format and those that did not, and we consider possible causes. Overall, we observe that student representational competence is tied to both micro- and macrolevel features of the task and environment.

  8. Reduced quality and accelerated follicle loss with female reproductive aging - does decline in theca dehydroepiandrosterone (DHEA) underlie the problem?

    PubMed

    Ford, Judith H

    2013-01-01

    Infertility, spontaneous abortion and conception of trisomic offspring increase exponentially with age in mammals but in women there is an apparent acceleration in the rate from about age 37. The problems mostly commonly occur when the ovarian pool of follicles is depleted to a critical level with age but are also found in low follicular reserve of other etiologies. Since recent clinical studies have indicated that dehydroepiandrosterone (DHEA) supplementation may reverse the problem of oocyte quality, this review of the literature was undertaken in an attempt to find an explanation of why this is effective? In affected ovaries, oxygenation of follicular fluid is low, ultrastructural disturbances especially of mitochondria, occur in granulosa cells and oocytes, and considerable disturbances of meiosis occur. There is, however, no evidence to date that primordial follicles are compromised. In females with normal fertility, pre-antral ovarian theca cells respond to stimulation by inhibin B to provide androgen-based support for the developing follicle. With depletion of follicle numbers, inhibin B is reduced with consequent reduction in theca DHEA. Theca cells are the sole ovarian site of synthesis of DHEA, which is both a precursor of androstenedione and an essential ligand for peroxisome proliferator-activated receptor alpha (PPARα), the key promoter of genes affecting fatty acid metabolism and fat transport and genes critical to mitochondrial function. As well as inducing a plethora of deleterious changes in follicular cytoplasmic structure and function, the omega 9 palmitate/oleate ratio is increased by lowered activity of PPARα. This provides conditions for increased ceramide synthesis and follicular loss through ceramide-induced apoptosis is accelerated. In humans critical theca DHEA synthesis occurs at about 70 days prior to ovulation thus effective supplementation needs to be undertaken about four months prior to intended conception; timing which is also

  9. Severe physical punishment: risk of mental health problems for poor urban children in Brazil

    PubMed Central

    Duarte, Cristiane S; Peres, Clovis A; Nascimento, Rosimeire; Curto, Bartira M; Paula, Cristiane S

    2009-01-01

    Abstract Objective To examine the relationship between specific types of child mental health problems and severe physical punishment, in combination with other important known risk factors. Methods We conducted a cross-sectional study in Embu, São Paulo, Brazil, as the Brazilian component of a multicountry survey on abuse in the family environment. From a probabilistic sample of clusters that included all eligible households (women aged 15–49 years with a son or daughter < 18 years of age), we randomly selected one mother–child pair per household (n = 813; attrition rate: 17.6%). This study focused on children aged 6–17 years (n = 480). Child Behaviour Checklist CBCL/6–18 was used to identify children with internalizing problems only, externalizing problems only, and both internalizing and externalizing problems (comorbidity). Severe physical punishment was defined as being hit with an object, being kicked, choked, smothered, burnt, scalded, branded, beaten or threatened with a weapon. We examined other potential correlates from four domains: child (gender, age, ever witnessing marital violence); mother (education, unemployment, anxiety or depression, marital violence); father (absence, drunkenness); and family (socioeconomic status). The WHO Self-Reporting Questionnaire (SRQ-20) was used to identify maternal anxiety or depression (score > 7). Backward logistic regression analysis identified independent correlates and significant interactions. Findings Multivariate modelling showed that severe punishment was an independent correlate of comorbid internalizing and externalizing problems but was not associated with internalizing problems only. It increased the risk of externalizing problems alone only for children and adolescents not exposed to maternal anxiety or depression. Maternal anxiety or depression increased the risk only for children or adolescents not exposed to severe punishment. Conclusion Severe punishment may be related to child mental

  10. On the problems of relativistic laboratory astrophysics and fundamental physics with super powerful lasers

    SciTech Connect

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J.; Kondo, K.; Korn, G.

    2015-01-15

    The ways toward modeling of astrophysical processes and extreme field regimes with super-power lasers are discussed. The main attention is paid to the problem of limited similarity in using the dimensionless parameters characterizing the processes in the laser and astrophysical plasmas. As the most typical examples, we address the magnetic reconnection and collisionless shock waves relevant to the problem of ultrarelativistic particle acceleration. In the extreme field limits we consider the regimes of dominant radiation reaction, changing the electromagnetic wave-matter interaction. In these regimes it, in particular, results in a new powerful source of ultra high-brightness gamma-rays and will make possible electron-positron pair creation in vacuum in a multiphoton processes. This will allow modeling under terrestrial laboratory conditions the processes in astrophysical objects and paves the way to experimental verifications using ultra intense lasers as they are currently developed within the ELI project.

  11. Effects of Turbulent Magnetic Fields on the Transport and Acceleration of Energetic Charged Particles: Numerical Simulations with Application to Heliospheric Physics

    NASA Astrophysics Data System (ADS)

    Guo, Fan

    2012-11-01

    Turbulent magnetic fields are ubiquitous in space physics and astrophysics. The influence of magnetic turbulence on the motions of charged particles contains the essential physics of the transport and acceleration of energetic charged particles in the heliosphere, which is to be explored in this thesis. After a brief introduction on the energetic charged particles and magnetic fields in the heliosphere, the rest of this dissertation focuses on three specific topics: 1. the transport of energetic charged particles in the inner heliosphere, 2. the acceleration of ions at collisionless shocks, and 3. the acceleration of electrons at collisionless shocks. We utilize various numerical techniques to study these topics. In Chapter 2 we study the propagation of charged particles in turbulent magnetic fields similar to the propagation of solar energetic particles in the inner heliosphere. The trajectories of energetic charged particles in the turbulent magnetic field are numerically integrated. The turbulence model includes a Kolmogorov-like magnetic field power spectrum containing a broad range of scales from those that lead to large-scale field-line random walk to small scales leading to resonant pitch-angle scattering of energetic particles. We show that small-scale variations in particle intensities (the so-called "dropouts") and velocity dispersions observed by spacecraft can be reproduced using this method. Our study gives a new constraint on the error of "onset analysis", which is a technique commonly used to infer information about the initial release of energetic particles. We also find that the dropouts are rarely produced in the simulations using the so-called "two-component" magnetic turbulence model (Matthaeus et al., 1990). The result questions the validity of this model in studying particle transport. In the first part of Chapter 3 we study the acceleration of ions in the existence of turbulent magnetic fields. We use 3-D self-consistent hybrid simulations

  12. High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems

    PubMed Central

    Mahadevan, Vijay S.; Merzari, Elia; Tautges, Timothy; Jain, Rajeev; Obabko, Aleksandr; Smith, Michael; Fischer, Paul

    2014-01-01

    An integrated multi-physics simulation capability for the design and analysis of current and future nuclear reactor models is being investigated, to tightly couple neutron transport and thermal-hydraulics physics under the SHARP framework. Over several years, high-fidelity, validated mono-physics solvers with proven scalability on petascale architectures have been developed independently. Based on a unified component-based architecture, these existing codes can be coupled with a mesh-data backplane and a flexible coupling-strategy-based driver suite to produce a viable tool for analysts. The goal of the SHARP framework is to perform fully resolved coupled physics analysis of a reactor on heterogeneous geometry, in order to reduce the overall numerical uncertainty while leveraging available computational resources. The coupling methodology and software interfaces of the framework are presented, along with verification studies on two representative fast sodium-cooled reactor demonstration problems to prove the usability of the SHARP framework. PMID:24982250

  13. High-resolution coupled physics solvers for analysing fine-scale nuclear reactor design problems.

    PubMed

    Mahadevan, Vijay S; Merzari, Elia; Tautges, Timothy; Jain, Rajeev; Obabko, Aleksandr; Smith, Michael; Fischer, Paul

    2014-08-01

    An integrated multi-physics simulation capability for the design and analysis of current and future nuclear reactor models is being investigated, to tightly couple neutron transport and thermal-hydraulics physics under the SHARP framework. Over several years, high-fidelity, validated mono-physics solvers with proven scalability on petascale architectures have been developed independently. Based on a unified component-based architecture, these existing codes can be coupled with a mesh-data backplane and a flexible coupling-strategy-based driver suite to produce a viable tool for analysts. The goal of the SHARP framework is to perform fully resolved coupled physics analysis of a reactor on heterogeneous geometry, in order to reduce the overall numerical uncertainty while leveraging available computational resources. The coupling methodology and software interfaces of the framework are presented, along with verification studies on two representative fast sodium-cooled reactor demonstration problems to prove the usability of the SHARP framework. PMID:24982250

  14. Creative problem solving and social cooperation of effective physical therapy practice: a pioneer study and overview.

    PubMed

    Carmeli, Eli

    2003-04-28

    Action research (AR) has an important role to play in educating physical therapists. Increasing efforts should be encouraged to instigate AR programs in physical therapy practice and clinical education. Such programs commonly require considerable effort and understanding by clinical instructors, and require adoption of new educational methods. AR programs can lead physical therapists and clinicians to be more questioning and reflective in evaluating practical questions regarding patient therapy and education. The purpose of this article is to educate the readers on the importance of AR and to provide a few relevant references on that topic. A specific study is described in this paper in which physical therapy clinical instructors participated in a structured workshop designed to demonstrate the values of AR and how such values can be incorporated in teaching their students. AR can lead to improved therapist-patient interaction and help solve specific practical problems arising during therapy sessions. PMID:12806114

  15. Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles.

    PubMed

    Xu, X L; Hua, J F; Wu, Y P; Zhang, C J; Li, F; Wan, Y; Pai, C-H; Lu, W; An, W; Yu, P; Hogan, M J; Joshi, C; Mori, W B

    2016-03-25

    Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles. PMID:27058082

  16. Physics of Phase Space Matching for Staging Plasma and Traditional Accelerator Components Using Longitudinally Tailored Plasma Profiles

    NASA Astrophysics Data System (ADS)

    Xu, X. L.; Hua, J. F.; Wu, Y. P.; Zhang, C. J.; Li, F.; Wan, Y.; Pai, C.-H.; Lu, W.; An, W.; Yu, P.; Hogan, M. J.; Joshi, C.; Mori, W. B.

    2016-03-01

    Phase space matching between two plasma-based accelerator (PBA) stages and between a PBA and a traditional accelerator component is a critical issue for emittance preservation. The drastic differences of the transverse focusing strengths as the beam propagates between stages and components may lead to a catastrophic emittance growth even when there is a small energy spread. We propose using the linear focusing forces from nonlinear wakes in longitudinally tailored plasma density profiles to control phase space matching between sections with negligible emittance growth. Several profiles are considered and theoretical analysis and particle-in-cell simulations show how these structures may work in four different scenarios. Good agreement between theory and simulation is obtained, and it is found that the adiabatic approximation misses important physics even for long profiles.

  17. Gendered emotion work around physical health problems in mid- and later-life marriages☆

    PubMed Central

    Thomeer, Mieke Beth; Reczek, Corinne; Umberson, Debra

    2015-01-01

    The provision and receipt of emotion work—defined as intentional activities done to promote another’s emotional well-being—are central dimensions of marriage. However, emotion work in response to physical health problems is a largely unexplored, yet likely important, aspect of the marital experience. We analyze dyadic in-depth interviews with husbands and wives in 21 mid-to later-life couples to examine the ways that health-impaired people and their spouses provide, interpret, and explain emotion work. Because physical health problems, emotion work, and marital dynamics are gendered, we consider how these processes differ for women and men. We find that wives provide emotion work regardless of their own health status. Husbands provide emotion work less consistently, typically only when the husbands see themselves as their wife’s primary source of stability or when the husbands view their marriage as balanced. Notions of traditional masculinity preclude some husbands from providing emotion work even when their wife is health-impaired. This study articulates emotion work around physical health problems as one factor that sustains and exacerbates gender inequalities in marriage with implications for emotional and physical well-being. PMID:25661852

  18. Conceptual design of a 1013 -W pulsed-power accelerator for megajoule-class dynamic-material-physics experiments

    NASA Astrophysics Data System (ADS)

    Stygar, W. A.; Reisman, D. B.; Stoltzfus, B. S.; Austin, K. N.; Ao, T.; Benage, J. F.; Breden, E. W.; Cooper, R. A.; Cuneo, M. E.; Davis, J.-P.; Ennis, J. B.; Gard, P. D.; Greiser, G. W.; Gruner, F. R.; Haill, T. A.; Hutsel, B. T.; Jones, P. A.; LeChien, K. R.; Leckbee, J. J.; Lewis, S. A.; Lucero, D. J.; McKee, G. R.; Moore, J. K.; Mulville, T. D.; Muron, D. J.; Root, S.; Savage, M. E.; Sceiford, M. E.; Spielman, R. B.; Waisman, E. M.; Wisher, M. L.

    2016-07-01

    We have developed a conceptual design of a next-generation pulsed-power accelerator that is optimized for megajoule-class dynamic-material-physics experiments. Sufficient electrical energy is delivered by the accelerator to a physics load to achieve—within centimeter-scale samples—material pressures as high as 1 TPa. The accelerator design is based on an architecture that is founded on three concepts: single-stage electrical-pulse compression, impedance matching, and transit-time-isolated drive circuits. The prime power source of the accelerator consists of 600 independent impedance-matched Marx generators. Each Marx comprises eight 5.8-GW bricks connected electrically in series, and generates a 100-ns 46-GW electrical-power pulse. A 450-ns-long water-insulated coaxial-transmission-line impedance transformer transports the power generated by each Marx to a system of twelve 2.5-m-radius water-insulated conical transmission lines. The conical lines are connected electrically in parallel at a 66-cm radius by a water-insulated 45-post sextuple-post-hole convolute. The convolute sums the electrical currents at the outputs of the conical lines, and delivers the combined current to a single solid-dielectric-insulated radial transmission line. The radial line in turn transmits the combined current to the load. Since much of the accelerator is water insulated, we refer to it as Neptune. Neptune is 40 m in diameter, stores 4.8 MJ of electrical energy in its Marx capacitors, and generates 28 TW of peak electrical power. Since the Marxes are transit-time isolated from each other for 900 ns, they can be triggered at different times to construct-over an interval as long as 1 μ s -the specific load-current time history required for a given experiment. Neptune delivers 1 MJ and 20 MA in a 380-ns current pulse to an 18 -m Ω load; hence Neptune is a megajoule-class 20-MA arbitrary waveform generator. Neptune will allow the international scientific community to conduct dynamic

  19. Physically based mathematical models in soil science: History, current state, problems, and outlook (Analytical Review)

    NASA Astrophysics Data System (ADS)

    Shein, E. V.

    2015-07-01

    The formation, development, and some problems of the current physically based models of water and solute transfer are considered in this review. These models appeared about a half century ago. They were based on the basic laws of soil physics and other branches of soil science (laws of balance, transfer, diffusion, hydrodynamic dispersion, etc.) described by the corresponding equations and programs and supported by the experimental data in the form of physically based parameters. At present, one of the main problems in the development, adaptation, and application of these models is that the current and future mathematical models should rest upon the experimental support with a clear physical basis characterizing the nature of the phenomenon described. This experimental support enables creating research models, drawing conceptual conclusions, and, hence, understanding, analyzing, and managing soil processes. This is apparently possible only if the set of methods for the experimental support of models is substantiated, preferably in direct physical experiments and under field conditions close to the future model prognoses.

  20. High-powered pulsed-ion-beam acceleration and transport

    SciTech Connect

    Humphries, S. Jr.; Lockner, T.R.

    1981-11-01

    The state of research on intense ion beam acceleration and transport is reviewed. The limitations imposed on ion beam transport by space charge effects and methods available for neutralization are summarized. The general problem of ion beam neutralization in regions free of applied electric fields is treated. The physics of acceleration gaps is described. Finally, experiments on multi-stage ion acceleration are summarized.

  1. Specification of the Advanced Burner Test Reactor Multi-Physics Coupling Demonstration Problem

    SciTech Connect

    Shemon, E. R.; Grudzinski, J. J.; Lee, C. H.; Thomas, J. W.; Yu, Y. Q.

    2015-12-21

    This document specifies the multi-physics nuclear reactor demonstration problem using the SHARP software package developed by NEAMS. The SHARP toolset simulates the key coupled physics phenomena inside a nuclear reactor. The PROTEUS neutronics code models the neutron transport within the system, the Nek5000 computational fluid dynamics code models the fluid flow and heat transfer, and the DIABLO structural mechanics code models structural and mechanical deformation. The three codes are coupled to the MOAB mesh framework which allows feedback from neutronics, fluid mechanics, and mechanical deformation in a compatible format.

  2. The Problem-Solving Process in Physics as Observed When Engineering Students at University Level Work in Groups

    ERIC Educational Resources Information Center

    Gustafsson, Peter; Jonsson, Gunnar; Enghag, Margareta

    2015-01-01

    The problem-solving process is investigated for five groups of students when solving context-rich problems in an introductory physics course included in an engineering programme. Through transcripts of their conversation, the paths in the problem-solving process have been traced and related to a general problem-solving model. All groups exhibit…

  3. Impact of Guided Reflection with Peers on the Development of Effective Problem Solving Strategies and Physics Learning

    ERIC Educational Resources Information Center

    Mason, Andrew J.; Singh, Chandralekha

    2016-01-01

    Students must learn effective problem solving strategies in order to develop expertise in physics. Effective problem solving strategies include a conceptual analysis of the problem followed by planning of the solution, and then implementation, evaluation, and reflection upon the process. Research suggests that converting a problem from the initial…

  4. Physical and mental health problems of the elderly in a rural community of sepang, selangor.

    PubMed

    Sidik, Sherina Mohd; Rampal, Lekhraj; Afifi, Mustaqim

    2004-01-01

    The prevalence of aging population is increasing not only in developed countries, but also in developing countries like Malaysia. The aim of this study was: (1) to determine the prevalence of physical and mental health problems, and (2) to determine the association of these health problems with socio demographic factors among the elderly in a rural community in Sepang, Selangor. A cross sectional study design was used. Five out of nine villages were selected via random sampling. The elderly in the selected villages were interviewed using a pre-tested structured questionnaire which included the GDS-30, ECAQ and Barthel Index. Out of 263 elderly residents (6.2% of the total population), 223 agreed to participate in the study giving a response rate of 84.8%. The mean age of the respondents was 69.7 + 6.8 years with a median of 68 years. The prevalence of physical health problems such as chronic illness and functional dependence were 60.1% and 15.7%, respectively. While the prevalence of mental health problems such as depression and cognitive impairment were 7.6% and 22.4%, respectively. Among the health problems studied, depression was found to be significantly associated with unemployment (p<0.05), where as cognitive impairment was significantly associated with age, gender, ethnicity, marital status and level of education (p<0.05). PMID:22977360

  5. Effect of physical training in cool and hot environments on +Gz acceleration tolerance in women

    NASA Technical Reports Server (NTRS)

    Brock, P. J.; Sciaraffa, D.; Greenleaf, J. E.

    1982-01-01

    Acceleration tolerance, plasma volume, and maximal oxygen uptake were measured in 15 healthy women before and after submaximal isotonic exercise training periods in cool and hot environments. The women were divided on the basis of age, maximal oxygen uptake, and +Gz tolerance into three groups: a group that exercised in heat (40.6 C), a group that exercised at a lower temperature (18.7 C), and a sedentary control group that functioned in the cool environment. There was no significant change in the +Gz tolerance in any group after training, and terminal heart rates were similar within each group. It is concluded that induction of moderate acclimation responses without increases in sweat rate or resting plasma volume has no influence on +Gz acceleration tolerance in women.

  6. Physical characteristics of photon beam from a CLINAC-DBX single energy accelerator

    NASA Astrophysics Data System (ADS)

    Umbarkar, Rahul; Supe, Sanjay; Pandey, Manoy; Ashok, Jayanty

    2011-01-01

    Commissioning beam data are treated as a reference and ultimately used by treatment planning systems, therefore, it is vitally important that the collected data are of the highest quality, in order to avoid dosimetric and patient treatment errors that may subsequently lead to a poor radiation outcome. High-energy photon and electron beams from different accelerators of the same nominal energy may have different dosimetric characteristics due to differences in target and flattening filter materials, accelerator guide and collimator designs. In the present study, clinically pertinent data for the available photon energy were investigated. For making measurements in water, first time in India, a three dimensional radiation field analyzer RFA (CRS- Scan -O-Plan) was used. For absolute dosimetry and other measurements like relative output factors, wedge factors etc., a DOSE1 electrometer (Scanditronix Wellhofer) in a white polystyrene was employed. All the measured data were utilized as an input to the ECLIPSE treatment planning system for further clinical use.

  7. Can Low-Energy Electrons Affect High-Energy Physics Accelerators?

    NASA Astrophysics Data System (ADS)

    Cimino, R.; Collins, I. R.; Furman, M. A.; Pivi, M.; Ruggiero, F.; Rumolo, G.; Zimmermann, F.

    2004-06-01

    Present and future accelerators' performances may be limited by the electron cloud (EC) effect. The EC formation and evolution are determined by the wall-surface properties of the accelerator vacuum chamber. We present measurements of the total secondary electron yield (SEY) and the related energy distribution curves of the secondary electrons as a function of incident-electron energy. Particular attention has been paid to the emission process due to very low-energy primary electrons (<20 eV). It is shown that the SEY approaches unity and the reflected electron component is predominant in the limit of zero primary incident electron energy. Motivated by these measurements, we have used state-of-the-art EC simulation codes to predict how these results may impact the production of the electron cloud in the Large Hadron Collider, under construction at CERN, and the related surface heat load.

  8. Plasma physics. Stochastic electron acceleration during spontaneous turbulent reconnection in a strong shock wave.

    PubMed

    Matsumoto, Y; Amano, T; Kato, T N; Hoshino, M

    2015-02-27

    Explosive phenomena such as supernova remnant shocks and solar flares have demonstrated evidence for the production of relativistic particles. Interest has therefore been renewed in collisionless shock waves and magnetic reconnection as a means to achieve such energies. Although ions can be energized during such phenomena, the relativistic energy of the electrons remains a puzzle for theory. We present supercomputer simulations showing that efficient electron energization can occur during turbulent magnetic reconnection arising from a strong collisionless shock. Upstream electrons undergo first-order Fermi acceleration by colliding with reconnection jets and magnetic islands, giving rise to a nonthermal relativistic population downstream. These results shed new light on magnetic reconnection as an agent of energy dissipation and particle acceleration in strong shock waves. PMID:25722406

  9. Design and Application of Interactive Simulations in Problem-Solving in University-Level Physics Education

    NASA Astrophysics Data System (ADS)

    Ceberio, Mikel; Almudí, José Manuel; Franco, Ángel

    2016-03-01

    In recent years, interactive computer simulations have been progressively integrated in the teaching of the sciences and have contributed significant improvements in the teaching-learning process. Practicing problem-solving is a key factor in science and engineering education. The aim of this study was to design simulation-based problem-solving teaching materials and assess their effectiveness in improving students' ability to solve problems in university-level physics. Firstly, we analyze the effect of using simulation-based materials in the development of students' skills in employing procedures that are typically used in the scientific method of problem-solving. We found that a significant percentage of the experimental students used expert-type scientific procedures such as qualitative analysis of the problem, making hypotheses, and analysis of results. At the end of the course, only a minority of the students persisted with habits based solely on mathematical equations. Secondly, we compare the effectiveness in terms of problem-solving of the experimental group students with the students who are taught conventionally. We found that the implementation of the problem-solving strategy improved experimental students' results regarding obtaining a correct solution from the academic point of view, in standard textbook problems. Thirdly, we explore students' satisfaction with simulation-based problem-solving teaching materials and we found that the majority appear to be satisfied with the methodology proposed and took on a favorable attitude to learning problem-solving. The research was carried out among first-year Engineering Degree students.

  10. Design and Application of Interactive Simulations in Problem-Solving in University-Level Physics Education

    NASA Astrophysics Data System (ADS)

    Ceberio, Mikel; Almudí, José Manuel; Franco, Ángel

    2016-08-01

    In recent years, interactive computer simulations have been progressively integrated in the teaching of the sciences and have contributed significant improvements in the teaching-learning process. Practicing problem-solving is a key factor in science and engineering education. The aim of this study was to design simulation-based problem-solving teaching materials and assess their effectiveness in improving students' ability to solve problems in university-level physics. Firstly, we analyze the effect of using simulation-based materials in the development of students' skills in employing procedures that are typically used in the scientific method of problem-solving. We found that a significant percentage of the experimental students used expert-type scientific procedures such as qualitative analysis of the problem, making hypotheses, and analysis of results. At the end of the course, only a minority of the students persisted with habits based solely on mathematical equations. Secondly, we compare the effectiveness in terms of problem-solving of the experimental group students with the students who are taught conventionally. We found that the implementation of the problem-solving strategy improved experimental students' results regarding obtaining a correct solution from the academic point of view, in standard textbook problems. Thirdly, we explore students' satisfaction with simulation-based problem-solving teaching materials and we found that the majority appear to be satisfied with the methodology proposed and took on a favorable attitude to learning problem-solving. The research was carried out among first-year Engineering Degree students.

  11. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    SciTech Connect

    Stygar, W. A.; Awe, T. J.; Bennett, N L; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; Genoni, T. C.; Gomez, M. R.; Greiser, G. W.; Gruner, F. R.; Herrmann, M. C.; Hutsel, B. T.; Jennings, C. A.; Jobe, D. O.; Jones, B. M.; Jones, M. C.; Jones, P. A.; Knapp, P. F.; Lash, J. S.; LeChien, K. R.; Leckbee, J. J.; Leeper, R. J.; Lewis, S. A.; Long, F. W.; Lucero, D. J.; Madrid, E. A.; Martin, M. R.; Matzen, M. K.; Mazarakis, M. G.; McBride, R. D.; McKee, G. R.; Miller, C. L.; Moore, J. K.; Mostrom, C. B.; Mulville, T. D.; Peterson, K. J.; Porter, J. L.; Reisman, D. B.; Rochau, G. A.; Rochau, G. E.; Rose, D. V.; Savage, M. E.; Sceiford, M. E.; Schmit, P. F.; Schneider, R. F.; Schwarz, J.; Sefkow, A. B.; Sinars, D. B.; Slutz, S. A.; Spielman, R. B.; Stoltzfus, B. S.; Thoma, C.; Vesey, R. A.; Wakeland, P. E.; Welch, D. R.; Wisher, M. L.; Woodworth, J. R.; Bailey, J. E.; Rovang, D. C.

    2015-11-30

    Here, we have developed conceptual designs of two petawatt-class pulsed-power accelerators: Z 300 and Z 800. The designs are based on an accelerator architecture that is founded on two concepts: single-stage electrical-pulse compression and impedance matching [Phys. Rev. ST Accel. Beams 10, 030401 (2007)]. The prime power source of each machine consists of 90 linear-transformer-driver (LTD) modules. Each module comprises LTD cavities connected electrically in series, each of which is powered by 5-GW LTD bricks connected electrically in parallel. (A brick comprises a single switch and two capacitors in series.) Six water-insulated radial-transmission-line impedance transformers transport the power generated by the modules to a six-level vacuum-insulator stack. The stack serves as the accelerator’s water-vacuum interface. The stack is connected to six conical outer magnetically insulated vacuum transmission lines (MITLs), which are joined in parallel at a 10-cm radius by a triple-post-hole vacuum convolute. The convolute sums the electrical currents at the outputs of the six outer MITLs, and delivers the combined current to a single short inner MITL. The inner MITL transmits the combined current to the accelerator’s physics-package load. Z 300 is 35 m in diameter and stores 48 MJ of electrical energy in its LTD capacitors. The accelerator generates 320 TW of electrical power at the output of the LTD system, and delivers 48 MA in 154 ns to a magnetized-liner inertial-fusion (MagLIF) target [Phys. Plasmas 17, 056303 (2010)]. The peak electrical power at the MagLIF target is 870 TW, which is the highest power throughout the accelerator. Power amplification is accomplished by the centrally located vacuum section, which serves as an intermediate inductive-energy-storage device. The principal goal of Z 300 is to achieve thermonuclear ignition; i.e., a fusion yield that exceeds the energy transmitted by the accelerator to the liner. 2D magnetohydrodynamic (MHD

  12. Conceptual designs of two petawatt-class pulsed-power accelerators for high-energy-density-physics experiments

    DOE PAGESBeta

    Stygar, W. A.; Awe, T. J.; Bennett, N L; Breden, E. W.; Campbell, E. M.; Clark, R. E.; Cooper, R. A.; Cuneo, M. E.; Ennis, J. B.; Fehl, D. L.; et al

    2015-11-30

    Here, we have developed conceptual designs of two petawatt-class pulsed-power accelerators: Z 300 and Z 800. The designs are based on an accelerator architecture that is founded on two concepts: single-stage electrical-pulse compression and impedance matching [Phys. Rev. ST Accel. Beams 10, 030401 (2007)]. The prime power source of each machine consists of 90 linear-transformer-driver (LTD) modules. Each module comprises LTD cavities connected electrically in series, each of which is powered by 5-GW LTD bricks connected electrically in parallel. (A brick comprises a single switch and two capacitors in series.) Six water-insulated radial-transmission-line impedance transformers transport the power generated bymore » the modules to a six-level vacuum-insulator stack. The stack serves as the accelerator’s water-vacuum interface. The stack is connected to six conical outer magnetically insulated vacuum transmission lines (MITLs), which are joined in parallel at a 10-cm radius by a triple-post-hole vacuum convolute. The convolute sums the electrical currents at the outputs of the six outer MITLs, and delivers the combined current to a single short inner MITL. The inner MITL transmits the combined current to the accelerator’s physics-package load. Z 300 is 35 m in diameter and stores 48 MJ of electrical energy in its LTD capacitors. The accelerator generates 320 TW of electrical power at the output of the LTD system, and delivers 48 MA in 154 ns to a magnetized-liner inertial-fusion (MagLIF) target [Phys. Plasmas 17, 056303 (2010)]. The peak electrical power at the MagLIF target is 870 TW, which is the highest power throughout the accelerator. Power amplification is accomplished by the centrally located vacuum section, which serves as an intermediate inductive-energy-storage device. The principal goal of Z 300 is to achieve thermonuclear ignition; i.e., a fusion yield that exceeds the energy transmitted by the accelerator to the liner. 2D magnetohydrodynamic (MHD

  13. Effects of Problem-Based Learning on University Students' Epistemological Beliefs about Physics and Physics Learning and Conceptual Understanding of Newtonian Mechanics

    ERIC Educational Resources Information Center

    Sahin, Mehmet

    2010-01-01

    This study investigated the effects of problem-based learning on students' beliefs about physics and physics learning and conceptual understanding of Newtonian mechanics. The study further examines the relationship between students' beliefs about physics and their conceptual understanding of mechanics concepts. Participants were 124 Turkish…

  14. Statistical Physics Methods Provide the Exact Solution to a Long-Standing Problem of Genetics

    NASA Astrophysics Data System (ADS)

    Samal, Areejit; Martin, Olivier C.

    2015-06-01

    Analytic and computational methods developed within statistical physics have found applications in numerous disciplines. In this Letter, we use such methods to solve a long-standing problem in statistical genetics. The problem, posed by Haldane and Waddington [Genetics 16, 357 (1931)], concerns so-called recombinant inbred lines (RILs) produced by repeated inbreeding. Haldane and Waddington derived the probabilities of RILs when considering two and three genes but the case of four or more genes has remained elusive. Our solution uses two probabilistic frameworks relatively unknown outside of physics: Glauber's formula and self-consistent equations of the Schwinger-Dyson type. Surprisingly, this combination of statistical formalisms unveils the exact probabilities of RILs for any number of genes. Extensions of the framework may have applications in population genetics and beyond.

  15. Fundamental Problems of Neutron Physics at the Spallation Neutron Source at the ORNL

    SciTech Connect

    Vladimir Gudkov

    2008-07-16

    We propose to provide theoretical support for the experimental program in fundamental neutron physics at the SNS. This includes the study of neutron properties, neutron beta-decay, parity violation effects and time reversal violation effects. The main purpose of the proposed research is to work on theoretical problems related to experiments which have a high priority at the SNS. Therefore, we will make a complete analysis of beta-decay process including calculations of radiative corrections and recoil corrections for angular correlations for polarized neutron decay, with an accuracy better that is supposed to be achieved in the planning experiments. Based on the results of the calculations, we will provide analysis of sensitivity of angular correlations to be able to search for the possible extensions of the Standard model. Also we will help to plan other experiments to address significant problems of modern physics and will work on their theoretical support.

  16. A new efficient recursive technique for solving singular boundary value problems arising in various physical models

    NASA Astrophysics Data System (ADS)

    Roul, Pradip

    2016-04-01

    The paper deals with a numerical technique for solving nonlinear singular boundary value problems arising in various physical models. First, we convert the original problem to an equivalent integral equation to surmount the singularity and employ afterward the boundary condition to compute the undetermined coefficient. Finally, the integral equation without undetermined coefficient is treated using homotopy perturbation method. The present method is implemented on three physical model examples: i) thermal explosions; ii) steady-state oxygen diffusion in a spherical shell; iii) the equilibrium of the isothermal gas sphere. The results obtained by the present method are compared with that obtained using finite-difference method, B-spline method and a numerical technique based on the direct integration method, and comparison reveals that the proposed method with few solution components produces similar results and the method is computationally efficient than others.

  17. Statistical Physics Methods Provide the Exact Solution to a Long-Standing Problem of Genetics.

    PubMed

    Samal, Areejit; Martin, Olivier C

    2015-06-12

    Analytic and computational methods developed within statistical physics have found applications in numerous disciplines. In this Letter, we use such methods to solve a long-standing problem in statistical genetics. The problem, posed by Haldane and Waddington [Genetics 16, 357 (1931)], concerns so-called recombinant inbred lines (RILs) produced by repeated inbreeding. Haldane and Waddington derived the probabilities of RILs when considering two and three genes but the case of four or more genes has remained elusive. Our solution uses two probabilistic frameworks relatively unknown outside of physics: Glauber's formula and self-consistent equations of the Schwinger-Dyson type. Surprisingly, this combination of statistical formalisms unveils the exact probabilities of RILs for any number of genes. Extensions of the framework may have applications in population genetics and beyond. PMID:26196831

  18. Gender differences in the reciprocal relationships between parental physical aggression and children's externalizing problem behavior in China.

    PubMed

    Xing, Xiaopei; Wang, Meifang; Zhang, Qing; He, Xiaorui; Zhang, Wenxin

    2011-10-01

    The study examines gender differences in the reciprocal relations between parental physical aggression and child externalizing problem behavior in China. Four hundred fifty-four Chinese elementary school-age children reported on three forms of their parents' physical aggression toward them (i.e., mild corporal punishment, severe corporal punishment, and physical abuse) and their externalizing problem behavior at two time points, 6 months apart. Structural equation modeling revealed that the three types of parental physical aggression predicted child externalizing problem behavior for girls but not boys, whereas child externalizing problem behavior predicted severe corporal punishment and physical abuse for boys but not girls; child externalizing problem behavior did not predict mild corporal punishment for either gender. The findings suggest that the intervention for and prevention of child externalizing problem behavior may be somewhat different for boys and girls in China. PMID:21823794

  19. Facilitating case reuse during problem solving in algebra-based physics

    NASA Astrophysics Data System (ADS)

    Mateycik, Frances Ann

    This research project investigates students' development of problem solving schemata while using strategies that facilitate the process of using solved examples to assist with a new problem (case reuse). Focus group learning interviews were used to explore students' perceptions and understanding of several problem solving strategies. Individual clinical interviews were conducted and quantitative examination data were collected to assess students' conceptual understanding, knowledge organization, and problem solving performance on a variety of problem tasks. The study began with a short one-time treatment of two independent, research-based strategies chosen to facilitate case reuse. Exploration of students' perceptions and use of the strategies lead investigators to select one of the two strategies to be implemented over a full semester of focus group interviews. The strategy chosen was structure mapping. Structure maps are defined as visual representations of quantities and their associations. They were created by experts to model the appropriate mental organization of knowledge elements for a given physical concept. Students were asked to use these maps as they were comfortable while problem solving. Data obtained from this phase of our study (Phase I) offered no evidence of improved problem solving schema. The 11 contact hour study was barely sufficient time for students to become comfortable using the maps. A set of simpler strategies were selected for their more explicit facilitation of analogical reasoning, and were used together during two more semester long focus group treatments (Phase II and Phase III of this study). These strategies included the use of a step-by-step process aimed at reducing cognitive load associated with mathematical procedure, direct reflection of principles involved in a given set of problems, and the direct comparison of problem pairs designed to be void of surface similarities (similar objects or object orientations) and sharing

  20. How Partner Gender Influences Female Students' Problem Solving in Physics Education

    NASA Astrophysics Data System (ADS)

    Ding, N.; Harskamp, E.

    2006-12-01

    Research has shown that female students cannot profit as much as male students can from cooperative learning in physics, especially in mixed-gender dyads. This study has explored the influence of partner gender on female students' learning achievement, interaction and the problem-solving process during cooperative learning. In Shanghai, a total of 50 students (26 females and 24 males), drawn from two classes of a high school, took part in the study. Students were randomly paired, and there were three research groups: mixed-gender dyads (MG), female-female dyads (FF) and male-male dyads (MM). Analysis of students' pre- and post-test performances revealed that female students in the single-gender condition solved physics problems more effectively than did those in the mixed-gender condition, while the same was not the case for male students. We further explored the differences between female and male communication styles, and content among the three research groups. It showed that the females' interaction content and problem-solving processes were more sensitive to partner gender than were those for males. This might explain why mixed-gender cooperation in physics disadvantages females in high schools.

  1. BES-HEP Connections: Common Problems in Condensed Matter and High Energy Physics, Round Table Discussion

    SciTech Connect

    Fradkin, Eduardo; Maldacena, Juan; Chatterjee, Lali; Davenport, James W

    2015-02-02

    On February 2, 2015 the Offices of High Energy Physics (HEP) and Basic Energy Sciences (BES) convened a Round Table discussion among a group of physicists on ‘Common Problems in Condensed Matter and High Energy Physics’. This was motivated by the realization that both fields deal with quantum many body problems, share many of the same challenges, use quantum field theoretical approaches and have productively interacted in the past. The meeting brought together physicists with intersecting interests to explore recent developments and identify possible areas of collaboration.... Several topics were identified as offering great opportunity for discovery and advancement in both condensed matter physics and particle physics research. These included topological phases of matter, the use of entanglement as a tool to study nontrivial quantum systems in condensed matter and gravity, the gauge-gravity duality, non-Fermi liquids, the interplay of transport and anomalies, and strongly interacting disordered systems. Many of the condensed matter problems are realizable in laboratory experiments, where new methods beyond the usual quasi-particle approximation are needed to explain the observed exotic and anomalous results. Tools and techniques such as lattice gauge theories, numerical simulations of many-body systems, and tensor networks are seen as valuable to both communities and will likely benefit from collaborative development.

  2. Hadron Physics at the Charm and Bottom Thresholds and Other Novel QCD Physics Topics at the NICA Accelerator Facility

    SciTech Connect

    Brodsky, Stanley J.; /SLAC

    2012-06-20

    The NICA collider project at the Joint Institute for Nuclear Research in Dubna will have the capability of colliding protons, polarized deuterons, and nuclei at an effective nucleon-nucleon center-of mass energy in the range {radical}s{sub NN} = 4 to 11 GeV. I briefly survey a number of novel hadron physics processes which can be investigated at the NICA collider. The topics include the formation of exotic heavy quark resonances near the charm and bottom thresholds, intrinsic strangeness, charm, and bottom phenomena, hidden-color degrees of freedom in nuclei, color transparency, single-spin asymmetries, the RHIC baryon anomaly, and non-universal antishadowing.

  3. Investigating the Usability and Efficacy of Customizable Computer Coaches for Introductory Physics Problem Solving

    NASA Astrophysics Data System (ADS)

    Aryal, Bijaya

    2016-03-01

    We have studied the impacts of web-based Computer Coaches on educational outputs and outcomes. This presentation will describe the technical and conceptual framework related to the Coaches and discuss undergraduate students' favorability of the Coaches. Moreover, its impacts on students' physics problem solving performance and on their conceptual understanding of physics will be reported. We used a qualitative research technique to collect and analyze interview data from 19 undergraduate students who used the Coaches in the interview setting. The empirical results show that the favorability and efficacy of the Computer Coaches differ considerably across students of different educational backgrounds, preparation levels, attitudes and epistemologies about physics learning. The interview data shows that female students tend to have more favorability supporting the use of the Coach. Likewise, our assessment suggests that female students seem to benefit more from the Coaches in their problem solving performance and in conceptual learning of physics. Finally, the analysis finds evidence that the Coach has potential for increasing efficiency in usage and for improving students' educational outputs and outcomes under its customized usage. This work was partially supported by the Center for Educational Innovation, Office of the Senior Vice President for Academic Affairs and Provost, University of Minnesota.

  4. Role of beliefs and emotions in numerical problem solving in university physics education

    NASA Astrophysics Data System (ADS)

    Bodin, Madelen; Winberg, Mikael

    2012-06-01

    Numerical problem solving in classical mechanics in university physics education offers a learning situation where students have many possibilities of control and creativity. In this study, expertlike beliefs about physics and learning physics together with prior knowledge were the most important predictors of the quality of performance of a task with many degrees of freedom. Feelings corresponding to control and concentration, i.e., emotions that are expected to trigger students’ intrinsic motivation, were also important in predicting performance. Unexpectedly, intrinsic motivation, as indicated by enjoyment and interest, together with students’ personal interest and utility value beliefs did not predict performance. This indicates that although a certain degree of enjoyment is probably necessary, motivated behavior is rather regulated by integration and identification of expertlike beliefs about learning and are more strongly associated with concentration and control during learning and, ultimately, with high performance. The results suggest that the development of students’ epistemological beliefs is important for students’ ability to learn from realistic problem-solving situations with many degrees of freedom in physics education.

  5. Physical activity, emotional and behavioural problems, maternal education and self-reported educational performance of adolescents.

    PubMed

    Kantomaa, M T; Tammelin, T H; Demakakos, P; Ebeling, H E; Taanila, A M

    2010-04-01

    This study examined whether physical activity, mental health and socio-economic position were associated with the overall academic performance and future educational plans of adolescents aged 15-16 years. We used a sample of 7002 boys and girls from the Northern Finland Birth Cohort 1986. Data were collected by a postal enquiry in 2001-02. Multivariable logistic regression models were estimated and adjusted for family structure and all variables in the models. In the fully adjusted models, higher levels of physical activity and high parental socio-economic position were associated with higher overall academic performance and future plans for higher education. High scoring on behavioural problems was related to lower overall academic performance and poorer future academic plans. In summary, a higher level of physical activity, fewer behavioural problems and higher socio-economic position were independently associated with high self-perceived overall academic performance and plans for higher education among adolescents. The interrelations of these factors and the positive relationship between physical activity, mental health and school outcomes provide a context of critical importance for future research, intervention programming and policy directed at improving the educational attainment of adolescents. PMID:19762353

  6. How Can We Improve Problem Solving in Undergraduate Biology? Applying Lessons from 30 Years of Physics Education Research

    PubMed Central

    Hoskinson, A.-M.; Caballero, M. D.; Knight, J. K.

    2013-01-01

    If students are to successfully grapple with authentic, complex biological problems as scientists and citizens, they need practice solving such problems during their undergraduate years. Physics education researchers have investigated student problem solving for the past three decades. Although physics and biology problems differ in structure and content, the instructional purposes align closely: explaining patterns and processes in the natural world and making predictions about physical and biological systems. In this paper, we discuss how research-supported approaches developed by physics education researchers can be adopted by biologists to enhance student problem-solving skills. First, we compare the problems that biology students are typically asked to solve with authentic, complex problems. We then describe the development of research-validated physics curricula emphasizing process skills in problem solving. We show that solving authentic, complex biology problems requires many of the same skills that practicing physicists and biologists use in representing problems, seeking relationships, making predictions, and verifying or checking solutions. We assert that acquiring these skills can help biology students become competent problem solvers. Finally, we propose how biology scholars can apply lessons from physics education in their classrooms and inspire new studies in biology education research. PMID:23737623

  7. Coupling Conceptual and Quantitative Problems to Develop Expertise in Introductory Physics Students

    NASA Astrophysics Data System (ADS)

    Singh, Chandralekha

    2008-10-01

    We discuss the effect of administering conceptual and quantitative isomorphic problem pairs (CQIPP) back to back vs. asking students to solve only one of the problems in the CQIPP in introductory physics courses. Students who answered both questions in a CQIPP often performed better on the conceptual questions than those who answered the corresponding conceptual questions only. Although students often took advantage of the quantitative counterpart to answer a conceptual question of a CQIPP correctly, when only given the conceptual question, students seldom tried to convert it into a quantitative question, solve it and then reason about the solution conceptually. Even in individual interviews, when students who were only given conceptual questions had difficulty and the interviewer explicitly encouraged them to convert the conceptual question into the corresponding quantitative problem by choosing appropriate variables, a majority of students were reluctant and preferred to guess the answer to the conceptual question based upon their gut feeling.

  8. The High-Luminosity upgrade of the LHC: Physics and Technology Challenges for the Accelerator and the Experiments

    NASA Astrophysics Data System (ADS)

    Schmidt, Burkhard

    2016-04-01

    In the second phase of the LHC physics program, the accelerator will provide an additional integrated luminosity of about 2500/fb over 10 years of operation to the general purpose detectors ATLAS and CMS. This will substantially enlarge the mass reach in the search for new particles and will also greatly extend the potential to study the properties of the Higgs boson discovered at the LHC in 2012. In order to meet the experimental challenges of unprecedented pp luminosity, the experiments will need to address the aging of the present detectors and to improve the ability to isolate and precisely measure the products of the most interesting collisions. The lectures gave an overview of the physics motivation and described the conceptual designs and the expected performance of the upgrades of the four major experiments, ALICE, ATLAS, CMS and LHCb, along with the plans to develop the appropriate experimental techniques and a brief overview of the accelerator upgrade. Only some key points of the upgrade program of the four major experiments are discussed in this report; more information can be found in the references given at the end.

  9. Marshak Lectureship Talk: Women in Physics in the Baltic States Region: Problems and Solutions

    NASA Astrophysics Data System (ADS)

    Satkovskiene, Dalia

    2008-03-01

    In this contribution the gender equality problem in physics will be discussed on the basis of the results obtained implementing the project ``Baltic States Network: Women in Sciences and High Technology'' (BASNET) initiated by Lithuanian women physicists and financed by European Commission. The main goal of BASNET project was creation of the regional Strategy how to deal with women in sciences problem in the Baltic States. It has some stages and the contribution follows them. The first one was in depth sociological study aiming to find out disincentives and barriers women scientists face in their career and work at science and higher education institutions. Analysis of results revealed wide range of problems concerned with science organization, management and financing common for both counterparts. However it also proved the existence of women discrimination in sciences. As main factors influencing women under-representation in Physics was found: the stereotypes existing in the society where physics is assigned to the masculine area of activity; failings of the science management system, where highest positions are distributed not using the institutionalized objective criteria but by voting, where the correctness of majority solutions is anticipated implicitly. In physics where male scientists are the majority (they also usually compose executive boards, committees etc.) results of such a procedures often are unfavorable for women. The same reasons also influence women ``visibility'' in physicist's community and as the consequence possibility to receive needed recourses for their research as well as appropriate presentation of results obtained. The study revealed also the conservatism of scientific community- reluctance to face existing in the scientific society problems and to start solving them. On the basis of the results obtained as well practice of other countries the common strategy of solving women in physics (sciences) in the Baltic States region was

  10. How Do They Solve It? An Insight into the Learner's Approach to the Mechanism of Physics Problem Solving

    ERIC Educational Resources Information Center

    Hegde, Balasubrahmanya; Meera, B. N.

    2012-01-01

    A perceived difficulty is associated with physics problem solving from a learner's viewpoint, arising out of a multitude of reasons. In this paper, we have examined the microstructure of students' thought processes during physics problem solving by combining the analysis of responses to multiple-choice questions and semistructured student…

  11. Talking Physics during Small-Group Work with Context-Rich Problems--Analysed from an Ownership Perspective

    ERIC Educational Resources Information Center

    Enghag, Margareta; Gustafsson, Peter; Jonsson, Gunnar

    2009-01-01

    This study provides analyses of the conversations when university students work in small groups solving context-rich physics problems. We constructed context-rich, open-ended physics problems related to everyday life situations that lack some information required to solve and complete the tasks. The students' ownership of learning, their actions…

  12. INTRODUCTION: The Physics of Chaos and Related Problems: Proceedings of the 59th Nobel Symposium

    NASA Astrophysics Data System (ADS)

    Lundqvist, Stig

    1985-01-01

    The physics of non-linear phenomena has developed in a remarkable way over the last couple of decades and has accelerated over the last few years, in particular because of the recent progress in the study of chaotic behaviour. In particular the discovery of the universal properties of the transition into chaos for certain classes of systems has stimulated much recent work in different directions both theoretically and experimentally. Chaos theory has become a real challenge to physicists in many different fields and also in many other disciplines such as astronomy, chemistry, medicine, meteorology and economics and social theory. The study of chaos-related phenomena has a truly interdisciplinary character and makes use of important concepts and methods from other disciplines. For the description of chaotic structures one needs a new, recently developed geometry called fractal geometry. For the discussion of the enormous richness of ordered structures which appear, one uses the theory of pattern recognition. In order to study even the simplest theoretical models describing chaos, a computer is essential. It should finally be mentioned that important aspects of computer science are related to the theory of order and chaos. A Nobel Symposium provides an excellent opportunity to bring together a group of prominent scientists for a stimulating exchange of new ideas and results. The Nobel Symposia are very small meetings by invitation only and the number of key participants is typically in the range 20-40. These symposia are organized through a special Nobel Symposium Committee after proposals from individuals. This symposium was sponsored by the Nobel Foundation through its Nobel Symposium Fund with grants from The Tercentenary Fund of the Bank of Sweden and The Knut Alice Wallenberg Foundation. Additional support was obtained from the Royal Academy of Sciences, The Nordic Institute for Theoretical Atomic Physics (NORDITA), Chalmers University of Technology and

  13. INTRODUCTION: The Physics of Chaos and Related Problems: Proceedings of the 59th Nobel Symposium

    NASA Astrophysics Data System (ADS)

    Lundqvist, Stig

    1985-01-01

    The physics of non-linear phenomena has developed in a remarkable way over the last couple of decades and has accelerated over the last few years, in particular because of the recent progress in the study of chaotic behaviour. In particular the discovery of the universal properties of the transition into chaos for certain classes of systems has stimulated much recent work in different directions both theoretically and experimentally. Chaos theory has become a real challenge to physicists in many different fields and also in many other disciplines such as astronomy, chemistry, medicine, meteorology and economics and social theory. The study of chaos-related phenomena has a truly interdisciplinary character and makes use of important concepts and methods from other disciplines. For the description of chaotic structures one needs a new, recently developed geometry called fractal geometry. For the discussion of the enormous richness of ordered structures which appear, one uses the theory of pattern recognition. In order to study even the simplest theoretical models describing chaos, a computer is essential. It should finally be mentioned that important aspects of computer science are related to the theory of order and chaos. A Nobel Symposium provides an excellent opportunity to bring together a group of prominent scientists for a stimulating exchange of new ideas and results. The Nobel Symposia are very small meetings by invitation only and the number of key participants is typically in the range 20-40. These symposia are organized through a special Nobel Symposium Committee after proposals from individuals. This symposium was sponsored by the Nobel Foundation through its Nobel Symposium Fund with grants from The Tercentenary Fund of the Bank of Sweden and The Knut Alice Wallenberg Foundation. Additional support was obtained from the Royal Academy of Sciences, The Nordic Institute for Theoretical Atomic Physics (NORDITA), Chalmers University of Technology and

  14. Dosimetric Characteristics of 6 MV Modified Beams by Physical Wedges of a Siemens Linear Accelerator.

    PubMed

    Zabihzadeh, Mansour; Birgani, Mohammad Javad Tahmasebi; Hoseini-Ghahfarokhi, Mojtaba; Arvandi, Sholeh; Hoseini, Seyed Mohammad; Fadaei, Mahbube

    2016-01-01

    Physical wedges still can be used as missing tissue compensators or filters to alter the shape of isodose curves in a target volume to reach an optimal radiotherapy plan without creating a hotspot. The aim of this study was to investigate the dosimetric properties of physical wedges filters such as off-axis photon fluence, photon spectrum, output factor and half value layer. The photon beam quality of a 6 MV Primus Siemens modified by 150 and 450 physical wedges was studied with BEAMnrc Monte Carlo (MC) code. The calculated present depth dose and dose profile curves for open and wedged photon beam were in good agreement with the measurements. Increase of wedge angle increased the beam hardening and this effect was more pronounced at the heal region. Using such an accurate MC model to determine of wedge factors and implementation of it as a calculation algorithm in the future treatment planning systems is recommended. PMID:27221838

  15. Introduction to high-energy physics and the Stanford Linear Accelerator Center (SLAC)

    SciTech Connect

    Clearwater, S.

    1983-03-01

    The type of research done at SLAC is called High Energy Physics, or Particle Physics. This is basic research in the study of fundamental particles and their interactions. Basic research is research for the sake of learning something. Any practical application cannot be predicted, the understanding is the end in itself. Interactions are how particles behave toward one another, for example some particles attract one another while others repel and still others ignore each other. Interactions of elementary particles are studied to reveal the underlying structure of the universe.

  16. Case study of a problem-based learning course of physics in a telecommunications engineering degree

    NASA Astrophysics Data System (ADS)

    Macho-Stadler, Erica; Jesús Elejalde-García, Maria

    2013-08-01

    Active learning methods can be appropriate in engineering, as their methodology promotes meta-cognition, independent learning and problem-solving skills. Problem-based learning is the educational process by which problem-solving activities and instructor's guidance facilitate learning. Its key characteristic involves posing a 'concrete problem' to initiate the learning process, generally implemented by small groups of students. Many universities have developed and used active methodologies successfully in the teaching-learning process. During the past few years, the University of the Basque Country has promoted the use of active methodologies through several teacher training programmes. In this paper, we describe and analyse the results of the educational experience using the problem-based learning (PBL) method in a physics course for undergraduates enrolled in the technical telecommunications engineering degree programme. From an instructors' perspective, PBL strengths include better student attitude in class and increased instructor-student and student-student interactions. The students emphasised developing teamwork and communication skills in a good learning atmosphere as positive aspects.

  17. The Impact of Problem-Based Learning on Engineering Students' Beliefs about Physics and Conceptual Understanding of Energy and Momentum

    ERIC Educational Resources Information Center

    Sahin, Mehmet

    2010-01-01

    The purpose of this paper is to investigate the impact of problem-based learning (PBL) on freshmen engineering students' beliefs about physics and physics learning (referred to as epistemological beliefs) and conceptual understanding of physics. The multiple-choice test of energy and momentum concepts and the Colorado learning attitudes about…

  18. Black hole physics. Black hole lightning due to particle acceleration at subhorizon scales.

    PubMed

    Aleksić, J; Ansoldi, S; Antonelli, L A; Antoranz, P; Babic, A; Bangale, P; Barrio, J A; Becerra González, J; Bednarek, W; Bernardini, E; Biasuzzi, B; Biland, A; Blanch, O; Bonnefoy, S; Bonnoli, G; Borracci, F; Bretz, T; Carmona, E; Carosi, A; Colin, P; Colombo, E; Contreras, J L; Cortina, J; Covino, S; Da Vela, P; Dazzi, F; De Angelis, A; De Caneva, G; De Lotto, B; de Oña Wilhelmi, E; Delgado Mendez, C; Dominis Prester, D; Dorner, D; Doro, M; Einecke, S; Eisenacher, D; Elsaesser, D; Fonseca, M V; Font, L; Frantzen, K; Fruck, C; Galindo, D; García López, R J; Garczarczyk, M; Garrido Terrats, D; Gaug, M; Godinović, N; González Muñoz, A; Gozzini, S R; Hadasch, D; Hanabata, Y; Hayashida, M; Herrera, J; Hildebrand, D; Hose, J; Hrupec, D; Idec, W; Kadenius, V; Kellermann, H; Kodani, K; Konno, Y; Krause, J; Kubo, H; Kushida, J; La Barbera, A; Lelas, D; Lewandowska, N; Lindfors, E; Lombardi, S; Longo, F; López, M; López-Coto, R; López-Oramas, A; Lorenz, E; Lozano, I; Makariev, M; Mallot, K; Maneva, G; Mankuzhiyil, N; Mannheim, K; Maraschi, L; Marcote, B; Mariotti, M; Martínez, M; Mazin, D; Menzel, U; Miranda, J M; Mirzoyan, R; Moralejo, A; Munar-Adrover, P; Nakajima, D; Niedzwiecki, A; Nilsson, K; Nishijima, K; Noda, K; Orito, R; Overkemping, A; Paiano, S; Palatiello, M; Paneque, D; Paoletti, R; Paredes, J M; Paredes-Fortuny, X; Persic, M; Poutanen, J; Prada Moroni, P G; Prandini, E; Puljak, I; Reinthal, R; Rhode, W; Ribó, M; Rico, J; Rodriguez Garcia, J; Rügamer, S; Saito, T; Saito, K; Satalecka, K; Scalzotto, V; Scapin, V; Schultz, C; Schweizer, T; Shore, S N; Sillanpää, A; Sitarek, J; Snidaric, I; Sobczynska, D; Spanier, F; Stamatescu, V; Stamerra, A; Steinbring, T; Storz, J; Strzys, M; Takalo, L; Takami, H; Tavecchio, F; Temnikov, P; Terzić, T; Tescaro, D; Teshima, M; Thaele, J; Tibolla, O; Torres, D F; Toyama, T; Treves, A; Uellenbeck, M; Vogler, P; Zanin, R; Kadler, M; Schulz, R; Ros, E; Bach, U; Krauß, F; Wilms, J

    2014-11-28

    Supermassive black holes with masses of millions to billions of solar masses are commonly found in the centers of galaxies. Astronomers seek to image jet formation using radio interferometry but still suffer from insufficient angular resolution. An alternative method to resolve small structures is to measure the time variability of their emission. Here we report on gamma-ray observations of the radio galaxy IC 310 obtained with the MAGIC (Major Atmospheric Gamma-ray Imaging Cherenkov) telescopes, revealing variability with doubling time scales faster than 4.8 min. Causality constrains the size of the emission region to be smaller than 20% of the gravitational radius of its central black hole. We suggest that the emission is associated with pulsar-like particle acceleration by the electric field across a magnetospheric gap at the base of the radio jet. PMID:25378461

  19. PREFACE: 17th International School on Condensed Matter Physics (ISCMP): Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications

    NASA Astrophysics Data System (ADS)

    Dimova-Malinovska, Doriana; Nesheva, Diana; Pecheva, Emilia; Petrov, Alexander G.; Primatarowa, Marina T.

    2012-12-01

    We are pleased to introduce the Proceedings of the 17th International School on Condensed Matter Physics: Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications, organized by the Institute of Solid State Physics of the Bulgarian Academy of Sciences. The Chairman of the School was Professor Alexander G Petrov. Like prior events, the School took place in the beautiful Black Sea resort of Saints Constantine and Helena near Varna, going back to the refurbished facilities of the Panorama hotel. Participants from 17 different countries delivered 31 invited lecturers and 78 posters, contributing through three sessions of poster presentations. Papers submitted to the Proceedings were refereed according to the high standards of the Journal of Physics: Conference Series and the accepted papers illustrate the diversity and the high level of the contributions. Not least significant factor for the success of the 17 ISCMP was the social program, both the organized events (Welcome and Farewell Parties) and the variety of pleasant local restaurants and beaches. Visits to the Archaeological Museum (rich in valuable gold treasures of the ancient Thracian culture) and to the famous rock monastery Aladja were organized for the participants from the Varna Municipality. These Proceedings are published for the second time by the Journal of Physics: Conference Series. We are grateful to the Journal's staff for supporting this idea. The Committee decided that the next event will take place again in Saints Constantine and Helena, 1-5 September 2014. It will be entitled: Challenges of the Nanoscale Science: Theory, Materials and Applications. Doriana Dimova-Malinovska, Diana Nesheva, Emilia Pecheva, Alexander G Petrov and Marina T Primatarowa Editors

  20. Solving the software protection problem with intrinsic personal physical unclonable functions.

    SciTech Connect

    Nithyanand, Rishab; Sion, Radu

    2011-09-01

    Physical Unclonable Functions (PUFs) or Physical One Way Functions (P-OWFs) are physical systems whose responses to input stimuli (i.e., challenges) are easy to measure (within reasonable error bounds) but hard to clone. The unclonability property comes from the accepted hardness of replicating the multitude of characteristics introduced during the manufacturing process. This makes PUFs useful for solving problems such as device authentication, software protection, licensing, and certified execution. In this paper, we focus on the effectiveness of PUFs for software protection in offline settings. We first argue that traditional (black-box) PUFs are not useful for protecting software in settings where communication with a vendor's server or third party network device is infeasible or impossible. Instead, we argue that Intrinsic PUFs are needed to solve the above mentioned problems because they are intrinsically involved in processing the information that is to be protected. Finally, we describe how sources of randomness in any computing device can be used for creating intrinsic-personal-PUFs (IP-PUF) and present experimental results in using standard off-the-shelf computers as IP-PUFs.

  1. Anxiety and physical health problems increase the odds of women having more severe symptoms of depression.

    PubMed

    Weiss, Sandra J; Simeonova, Diana I; Kimmel, Mary C; Battle, Cynthia L; Maki, Pauline M; Flynn, Heather A

    2016-06-01

    Severely depressed women incur substantial disability and suicide risk, necessitating an understanding of factors that may contribute to severe depression. The purpose of this research was to determine the degree to which age, physical morbidity, anxiety, and hormonal status predict the likelihood of severe depression among women with mood disorders (n = 298). Data arose from a standardized battery of measures in a multi-center clinical registry of patients with mood disorders. The women were being treated at 17 participating sites of the National Network of Depression Centers. Results of logistic regression analyses indicate that a woman's level of anxiety was the strongest predictor of her likelihood of having severe depression (Exp(B) = 1.33, p = .000), including thoughts of death or suicide. The number of physical health problems that a woman reported was also a significant predictor (Exp(B) = 1.09, p = .04). Neither age nor hormonal status was significant in the final model, although a trend was observed for women with surgically induced menopause to have more severe depression. Findings support the need to work closely with medical practitioners to address physical health problems as part of the treatment plan for depression and to give comorbid anxiety and depression equal priority in symptom management. PMID:26403982

  2. Accelerated Integrated Science Sequence (AISS): An Introductory Biology, Chemistry, and Physics Course

    ERIC Educational Resources Information Center

    Purvis-Roberts, Kathleen L.; Edwalds-Gilbert, Gretchen; Landsberg, Adam S.; Copp, Newton; Ulsh, Lisa; Drew, David E.

    2009-01-01

    A new interdisciplinary, introductory science course was offered for the first time during the 2007-2008 school year. The purpose of the course is to introduce students to the idea of working at the intersections of biology, chemistry, and physics and to recognize interconnections between the disciplines. Interdisciplinary laboratories are a key…

  3. The Nature and Role of Thought Experiments in Solving Conceptual Physics Problems

    NASA Astrophysics Data System (ADS)

    Kösem, Şule Dönertaş; Özdemir, Ömer Faruk

    2014-04-01

    This study describes the possible variations of thought experiments in terms of their nature, purpose, and reasoning resources adopted during the solution of conceptual physics problems. A phenomenographic research approach was adopted for this study. Three groups of participants with varying levels of physics knowledge—low, medium, and high level—were selected in order to capture potential variations. Five participants were selected within each level group and the study was conducted with fifteen participants in total. Think aloud and retrospective questioning strategies were used throughout the individually conducted problem solving sessions to capture variations in the participants' thinking processes. The analysis of the data showed that thought experiments were actively used cognitive tools by participants from all there levels while working on the problems. Four different thought experiment structures were observed and categorized as limiting case, extreme case, simple case, and familiar case. It was also observed that participants conducted thought experiments for different purposes such as prediction, proof, and explanation. The reasoning resources behind the thought experiment processes were classified in terms of observed facts, intuitive principles, and scientific concepts. The results of the analysis suggested that thought experiments used as a creative reasoning tool for scientists can also be a productive tool for students. It was argued that instructional practices enriched with thought experiments and related practices not only reveal hidden elements of students' reasoning but also provide students opportunities to advance their inquiry skills through thought experimentation processes.

  4. DAG Software Architectures for Multi-Scale Multi-Physics Problems at Petascale and Beyond

    NASA Astrophysics Data System (ADS)

    Berzins, Martin

    2015-03-01

    The challenge of computations at Petascale and beyond is to ensure how to make possible efficient calculations on possibly hundreds of thousands for cores or on large numbers of GPUs or Intel Xeon Phis. An important methodology for achieving this is at present thought to be that of asynchronous task-based parallelism. The success of this approach will be demonstrated using the Uintah software framework for the solution of coupled fluid-structure interaction problems with chemical reactions. The layered approach of this software makes it possible for the user to specify the physical problems without parallel code, for that specification to be translated into a parallel set of tasks. These tasks are executed using a runtime system that executes tasks asynchronously and sometimes out-of-order. The scalability and portability of this approach will be demonstrated using examples from large scale combustion problems, industrial detonations and multi-scale, multi-physics models. The challenges of scaling such calculations to the next generations of leadership class computers (with more than a hundred petaflops) will be discussed. Thanks to NSF, XSEDE, DOE NNSA, DOE NETL, DOE ALCC and DOE INCITE.

  5. Modern problems in the physical sciences (Scientific session of the Physical Sciences Division of the Russian Academy of Sciences, 23 November 2011)

    NASA Astrophysics Data System (ADS)

    2012-07-01

    On 23 November 2011, the scientific session of the Physical Sciences Division of the Russian Academy of Sciences (RAS) was held at the conference hall of the Lebedev Physical Institute, RAS.The following reports were put on the session agenda posted on the website www.gpad.ac.ru of the RAS Physical Sciences Division: (1) Ionin A A (Lebedev Physical Institute, RAS, Moscow) "High-power infrared and ultraviolet lasers and their applications"; (2) Romanovskii M Yu (Prokhorov General Physics Institute, RAS, Moscow) "Laser-induced acceleration of the forbidden captures of orbital electrons by nuclei"; (3) Petrukovich A A (Space Research Institute, RAS, Moscow) "Earth's magnetosphere as a plasma laboratory"; (4) Shchur L N (Landau Institute for Theoretical Physics, RAS, Chernogolovka, Moscow region) "Computational physics and the verification of theoretical predictions". Articles written on the base of oral reports 1, 2, and 4 are published below. • High-power IR- and UV-laser systems and their applications, A A Ionin Physics-Uspekhi, 2012, Volume 55, Number 7, Pages 721-728 • Laser radiation enhancement of forbidden orbital electron captures and of neutrinoless double electron captures by nuclei, M Yu Romanovskii Physics-Uspekhi, 2012, Volume 55, Number 7, Pages 728-733 • Computational physics and testing theoretical predictions, L N Shchur Physics-Uspekhi, 2012, Volume 55, Number 7, Pages 733-738

  6. Overview of Some New Techniques for Inspection: Using 1950's Physics to Solve Modern Problems

    NASA Astrophysics Data System (ADS)

    Lanza, Richard

    2007-04-01

    The goal of any inspection technique is to non-intrusively determine the presence of such materials in a manner which is consistent with not interrupting the normal scheme of commerce and which, at the same time, exhibits a high probability of detection and a low probability of false alarms. A great deal of work has been reported in the literature on neutron based techniques for the detection of explosives with by far the largest impetus coming from the requirements of the commercial aviation industry for the inspection of luggage and, to a lesser extent, cargo; for baggage, the major techniques are either x-ray based or are chemical trace detection methods which look for small traces of explosive residues. Nuclear techniques have been proposed for the detection of explosives and contraband for a number of years due to their ability to penetrate shielding and to identify the elemental composition of materials, thus leading to enhanced detection probability and lower false alarm rates. Nuclear techniques are virtually the only method which can both detect and identify the presence of fissile materials, either in the form of bulk material or assembled weapons. Some examples of current work in nuclear based systems currently under development will be discussed such as nuclear resonance radiography, nuclear resonance fluorescence, pulsed fast neutron analysis and pulsed photonuclear detection. The physical basis of these techniques is well known, the physics having been studied in the 1950's, but there remain limitations on current technology with respect to e.g. radiation sources and detectors and data acquisition methods. Accelerator-based systems often are large and are often not well suited for field use; radiation detectors often suffer from limited count rate ability, low sensitivity and poor energy resolution and data acquisition and analysis methods usually rely on analog techniques which are not always stable in field operation. Current research in basic

  7. Longitudinal study of self-regulation, positive parenting, and adjustment problems among physically abused children

    PubMed Central

    Kim, Jungmeen; Haskett, Mary E.; Longo, Gregory S.; Nice, Rachel

    2012-01-01

    Objective Research using normative and high-risk samples indicates a significant link between problems with self-regulation and child maladjustment. Nevertheless, little is known about the processes that may modify the link between self-regulation and maladjustment. This longitudinal study examined the joint contributions of child self-regulation and positive parenting behaviors to the development of externalizing and internalizing symptomatology spanning from preschool to 1st grade. Methods Data were collected on a total of 95 physically abused children (58% boys); our longitudinal analyses involved 43 children at Time 1 (preschool), 63 children at Time 2 (kindergarten), and 54 children at Time 3 (1st grade). Children's self-regulation was measured by parent report, and their externalizing and internalizing symptomatology was evaluated by teachers. Parents completed self-report measures of positive parenting. Results Our structural equation modeling analyses revealed positive parenting as a protective factor that attenuated the concurrent association between low self-regulation and externalizing symptomatology among physically abused children. Our findings regarding longitudinal changes in children's externalizing symptomatology supported the differential susceptibility hypothesis: Physically abused children who were at greater risk due to low levels of self-regulation were more susceptible to the beneficial effects of positive parenting, compared to those with high levels of self-regulation. Conclusions Findings suggest that although physical abuse presents formidable challenges that interfere with the development of adaptive self-regulation, positive parenting behaviors may ameliorate the detrimental effects of maladaptive self-regulation on the development of externalizing symptomatology. In addition, the positive and negative effects of caregiving behaviors were more prominent among physically abused children at great risk due to low self-regulation. Practice

  8. High rates of alcohol problems and history of physical and sexual abuse among women inpatients.

    PubMed

    Swett, C; Halpert, M

    1994-01-01

    A total of 88 consecutive new women patients were surveyed on an adult psychiatric inpatient unit which did not have a specific program for the treatment of alcoholics. Those with a self-reported history of physical and/or sexual abuse had significantly higher scores on the Michigan Alcoholism Screening Test (MAST) than those with no such history. Former drinkers and teetotalers were more likely to have been both physically and sexually abused than the others. Thirty-three patients (38%) reported a history of alcohol problems measured by scores of seven or more on the MAST, but only 20 had a diagnosis of alcohol abuse or alcohol dependence made by a psychiatrist. PMID:8042607

  9. Optimization of solving the boundary-value problems related to physical geodesy.

    NASA Astrophysics Data System (ADS)

    Macák, Marek; Mikula, Karol

    2016-04-01

    Our aim is to present different approaches for optimization of solving the boundary-value problem related to physical geodesy in spatial domain. In physical geodesy, efficient numerical methods like the finite element method, boundary element method or finite volume method represent alternatives to classical approaches (e.g. the spherical harmonics). They lead to a solution of the linear system and in this context, we focus on three tasks. First task is to choose the fastest solver with respect to the number of iteration and computational time. The second one is to use parallel techniques (MPI or OpenMP) and the third one is to implement advance method like Multigrid and Domain decomposition. All presented examples deal with the gravity field modelling.

  10. Incorporating Sustainability and 21st-Century Problem Solving into Physics Courses

    NASA Astrophysics Data System (ADS)

    Rogers, Michael; Pfaff, Tom; Hamilton, Jason; Erkan, Ali

    2013-09-01

    As educators we are facing an unprecedented challenge to prepare our students not only for traditional careers but also for future careers that don't exist today. Many of these careers will require a firm grounding in disciplines such as physics, along with multidisciplinary, Global, and systems thinking skill sets. Our Multidisciplinary Sustainability Education (MSE) project is addressing this challenge by creating sustainability-themed modules where a variety of courses in a range of disciplines tackle relevant, real-world problems from each discipline's perspective. Each course involved in a module, which addresses an overarching question, has students write technical reports, using their discipline knowledge to address the question, and they are expected to read and synthesize reports from other discipline-based courses. This paper discusses one of our modules, "What Are the Current and Future Impacts of Global Climate Change on Polar Bears?" and how students studying thermal physics can help answer this question.

  11. Theory of elementary particles and accelerator theory: Task C: Experimental high energy physics. Annual progress report

    SciTech Connect

    Brau, J.E.

    1992-12-31

    The experimental high energy physics group at the University of Oregon broadened its effort during the past year. The SLD effort extends from maintaining and operating the SLD luminosity monitor which was built at Oregon, to significant responsibility in physics analysis, such as event selection and background analysis for the left-right asymmetry measurement. The OPAL work focussed on the luminosity monitor upgrade to a silicon-tungsten calorimeter. Building on the work done at Oregon for SLD, the tungsten for this upgrade was machined by the Oregon shops and shipped to CERN for assembly. The Oregon GEM effort now concentrates on tracking, specifically silicon tracking. Oregon also has developed a silicon strip preradiator prototype, and tested it in a Brookhaven beam.

  12. Theory of elementary particles and accelerator theory: Task C: Experimental high energy physics. [Univ. of Oregon

    SciTech Connect

    Brau, J.E.

    1992-01-01

    The experimental high energy physics group at the University of Oregon broadened its effort during the past year. The SLD effort extends from maintaining and operating the SLD luminosity monitor which was built at Oregon, to significant responsibility in physics analysis, such as event selection and background analysis for the left-right asymmetry measurement. The OPAL work focussed on the luminosity monitor upgrade to a silicon-tungsten calorimeter. Building on the work done at Oregon for SLD, the tungsten for this upgrade was machined by the Oregon shops and shipped to CERN for assembly. The Oregon GEM effort now concentrates on tracking, specifically silicon tracking. Oregon also has developed a silicon strip preradiator prototype, and tested it in a Brookhaven beam.

  13. The role of physical activity to control obesity problem in Malaysia

    NASA Astrophysics Data System (ADS)

    Abidin, Norhaslinda Zainal; Zaibidi, Nerda Zura; Zulkepli, Jafri Hj

    2014-07-01

    Obesity is defined as a condition in which an individual has an excess of body fat and it is accumulated to the extent that it can lead to numerous health problems and decreases the quality and length of life. Overall, the contributing factor to obesity varies. Lack of physical activity and increased sedentary behaviour has been identified as the causes of weight gain and various health implications including obesity. Rapid development in industrialization and urbanization has brought Malaysia to be the next millennium country in the world, and this causes changes in the country's socioeconomic, especially the lifestyles of Malaysians. In conjunction with this, the aim of this paper is to simulate the changes in physical activities and to highlight its implication on body weight and prevalence of overweight and obesity in a Malaysian adult population. This study combines different strands of knowledge consisting of nutrition, physical activity and body metabolism, and these elements have been synthesised into a system dynamics model called SIMULObese. The development of this model has considered the interrelations between those various strands in one multifaceted human weight regulation system. Findings from this study revealed that Malaysian adults perform less physical activity and this has resulted in weight gain and increase in prevalence of overweight and obesity. Therefore, findings from this study bring the important message to various parties such as practitioners, researchers, educators and publics about the importance of focusing on combinations of intensity, frequency and duration of moderate-vigorous activity for adult obesity control in Malaysia.

  14. Neutronic and Physical Characteristics of an Accelerator Driven System with a Lead-208 Coolant

    SciTech Connect

    Khorasanov, Georgy L.; Ivonov, Anatoly P.; Blokhin, Anatoly I.

    2006-07-01

    In the paper a possibility of using a lead isotope, pure Pb-208, as a coolant for a subcritical core of 80 MW thermal capacity of the PDS-XADS type facility is considered. Calculations of neutronic characteristics were performed using Monte Carlo technique. The following initial data were chosen: an annular core with a target, as a neutron source, at its centre; the core coolant -- Pb-208 (100%); a fuel -- a mix of mono nitrides of depleted uranium and power plutonium with a small share of neptunium and americium; the target coolant -- a modified lead and bismuth eutectic, Pb-208(80%)-Bi(20%); proton beam energy -- 600 MeV; effective multiplication factor of the core under operation -- K{sub eff} = 0.97; thermal capacity of the core -- N = 80 MW. From calculations performed it follows that in using Pb-208 as the core coolant the necessary intensity of the external source of neutrons to deliver 80 MW thermal capacity is equal to S = 2.29-10{sup 17} n/s that corresponds to proton beam current I{sub p} = 2.8 mA and beam capacity P{sub p} 1.68 MW. In using natural lead instead of Pb-208 as the core coolant, effective multiplication factor of the core in normal operating regime falls down to the value equal to K{sub eff} = 0.95. In these conditions multiplication of external neutrons in the core and thermal capacity of the subcritical core are below nominal by 1.55 times. For achievement the rated core power N=80 MW it is required on {approx}20-30% to increase the fuel loading and volume of the core, or by 1.55 times to increase intensity of the external source of neutrons. In the last case, the required parameters of the neutron source and of the corresponding proton beam are following: intensity of the neutron source S = 3.55 10{sup 17} n/s., beam current I{sub p} = 4.32 mA, beam capacity P{sub p} 2.59 MW. To exploit the accelerator with the reduced proton beam current it will be required about 56 tons of Pb-208, as a minimum, for the core coolant. Charges for its

  15. Progress on plasma accelerators

    SciTech Connect

    Chen, P.

    1986-05-01

    Several plasma accelerator concepts are reviewed, with emphasis on the Plasma Beat Wave Accelerator (PBWA) and the Plasma Wake Field Accelerator (PWFA). Various accelerator physics issues regarding these schemes are discussed, and numerical examples on laboratory scale experiments are given. The efficiency of plasma accelerators is then revealed with suggestions on improvements. Sources that cause emittance growth are discussed briefly.

  16. Global problems in magnetospheric plasma physics and prospects for their solution

    NASA Technical Reports Server (NTRS)

    Roederer, J. G.

    1977-01-01

    Selected problems in magnetospheric plasma physics are critically reviewed. The discussion is restricted to questions that are 'global' in nature (i.e., involve the magnetosphere as a whole) and that are beyond the stage of systematic survey or isolated study requirements. Only low-energy particle aspects are discussed. The article focuses on the following subjects: (1) the effect of the interplanetary magnetic field on the topography, topology, and stability of the magnetospheric boundary; (2) solar-wind plasma entry into the magnetosphere; (3) plasma storage and release mechanisms in the magnetospheric tail; and (4) magnetic-field-aligned currents and magnetosphere-ionosphere interactions. A brief discussion of the prospects for the solution of these problems during and after the International Magnetospheric Study is given.

  17. Solving Heat Conduction Problems in Movable Boundary Domains under Intensive Physical-Chemical Transformation Conditions

    NASA Astrophysics Data System (ADS)

    Garashchenko, A. N.; Rudzinsky, V. P.; Garashchenko, N. A.

    2016-02-01

    Results of solving problems of simulating temperature fields in domains with movable boundaries of characteristic zones of intensive physical-chemical and thermomechanical transformations to be realized in materials upon high-temperature heating have been presented. Intumescent fire-protective coatings based on organic and mineral materials are the object of study. Features of numerical realization of input equation systems taking into account, in particular, a dynamics of considerable increase and subsequent decrease of the intumescent layer thickness have been considered. Example calculations for structures of metal and wood protected with various coatings are given. Results of calculating two-dimensional temperature fields in polymer composite square-shaped structures with internal cruciform load-bearing elements have been presented. The intumescent coating is arranged on the external surface of a structure. The solution of the above-listed problems is of important significance to provide fire protection of different-purpose structures and products.

  18. Computer problem-solving coaches for introductory physics: Design and usability studies

    NASA Astrophysics Data System (ADS)

    Ryan, Qing X.; Frodermann, Evan; Heller, Kenneth; Hsu, Leonardo; Mason, Andrew

    2016-06-01

    The combination of modern computing power, the interactivity of web applications, and the flexibility of object-oriented programming may finally be sufficient to create computer coaches that can help students develop metacognitive problem-solving skills, an important competence in our rapidly changing technological society. However, no matter how effective such coaches might be, they will only be useful if they are attractive to students. We describe the design and testing of a set of web-based computer programs that act as personal coaches to students while they practice solving problems from introductory physics. The coaches are designed to supplement regular human instruction, giving students access to effective forms of practice outside class. We present results from large-scale usability tests of the computer coaches and discuss their implications for future versions of the coaches.

  19. An R-matrix package for coupled-channel problems in nuclear physics

    NASA Astrophysics Data System (ADS)

    Descouvemont, P.

    2016-03-01

    We present an R-matrix Fortran package to solve coupled-channel problems in nuclear physics. The basis functions are chosen as Lagrange functions, which permits simple calculations of the matrix elements. The main input is the coupling potentials at some nucleus-nucleus distances, specified by the program. The program provides the collision matrix and, optionally, the associated wave function. The present method deals with open and closed channels simultaneously, without numerical instability associated with closed channels. It can also solve coupled-channel problems for non-local potentials. Long-range potentials can be treated with propagation techniques, which significantly speed up the calculations. We first present an overview of the R-matrix theory, and of the Lagrange-mesh method. A description of the package and its installation on a UNIX machine is then provided. Finally, five typical examples are discussed.

  20. Conceptual chains and its application to study solving problems in physics

    NASA Astrophysics Data System (ADS)

    Lopez Campos, Carlos Enrique

    2010-03-01

    This work reports a theoretical model developed with the aim to explain the mental mechanisms of knowledge building during the problem-solving process in physics using a hybrid approach of assimilation- formation of concepts. The model has been termed conceptual chains and represents graphic diagrams of conceptual dependency, which have yielded information about the background knowledge required during the learning process, as well as about the formation of diverse structures that correspond to distinct forms of networking concepts. Additionally, the conceptual constructs of the model have been classified according to five types of knowledge. Evidence was found about the influence of these structures, as well as of the distinct types of knowledge about the degree of difficulty of the problems.

  1. Algebraic rings of integers and some 2D lattice problems in physics

    NASA Astrophysics Data System (ADS)

    Nanxian, Chen; Zhaodou, Chen; Shaojun, Liu; Yanan, Shen; Xijin, Ge

    1996-09-01

    This paper develops the Möbius inversion formula for the Gaussian integers and Eisenstein's integers, and gives two applications. The first application is to the two-dimensional arithmetic Fourier transform (AFT), which is suitable for parallel processing. The second application is to two-dimensional inverse lattice problems, and is illustrated with the recovery of interatomic potentials from the cohesive energy for monolayer graphite. The paper demonstrates the potential application in the physical science of integral domains other than the standard integers.

  2. Student performance in computer modeling and problem solving in a modern introductory physics course

    NASA Astrophysics Data System (ADS)

    Kohlmyer, Matthew Adam

    Matter & Interactions, an innovative introductory physics curriculum developed by Ruth Chabay and Bruce Sherwood, emphasizes computer modeling and fundamental physical principles. Two think-aloud protocol studies were conducted to investigate the performance of students from this curriculum in solving physics problems that require computer modeling. Experiment 1 examined whether Matter & Interactions students would, given the choice, use computer modeling to solve difficult problems that required predicting motion, and how their solution approaches differed from those of students from a traditional introductory physics course. Though they did not overwhelmingly choose computer modeling, some M&I students did write computer models successfully or apply the iterative algorithm by hand. The solution approaches of M&I students and traditional course students differed qualitatively in their use of the momentum principle and pre-derived special case formulas. In experiment 2, Matter & Interactions students were observed while they wrote programs in the VPython language in order to examine their difficulties with computer modeling. Areas of difficulty included determining initial conditions, distinguishing between simulated time and the time step, and updating momentum and position. Especially troublesome for students was the multistep procedure for calculating a force that changes with time. Students' understanding of the structure of a computer model improved by the end of the semester as shown by their performance on a line sorting task. Students with fewer difficulties proceeded through the computer model in a more linear, straightforward fashion. Instruction was revised based on initial findings from the first phase of the experiment. Students in the second phase of the experiment, who had used the revised instruction, had fewer difficulties on the same tasks, though other factors may have been involved in the improvement.

  3. Accelerating Translation of Physical Activity and Cancer Survivorship Research into Practice: Recommendations for a More Integrated and Collaborative Approach

    PubMed Central

    Phillips, Siobhan M.; Alfano, Catherine M.; Perna, Frank M.; Glasgow, Russell E.

    2015-01-01

    Physical activity has been deemed safe and effective in reducing many negative side effects of treatment for cancer survivors and promoting better overall health. However, most of this research has focused on highly controlled randomized trials and little of this research has been translated into care or policy for survivors. The purpose of the present paper is to present a research agenda for the field to accelerate the dissemination and implementation of empirically-supported physical activity interventions into care. We provide rationale for the role of basic, behavioral, clinical implementation and population scientists in moving this science forward and call for a more coordinated effort across different phases of research. In addition, we provide key strategies and examples for ongoing and future studies using the RE-AIM (Reach, Efficacy/Effectiveness, Adoption, Implementation and Maintenance) framework and pose recommendations for collaborations between researchers and stakeholders to enhance the integration of this research into policy and practice. Overall, we recommend that physical activity and cancer survivorship research employ additional study designs, include relevant stakeholders and be more collaborative, integrated, contextual, and representative in terms of both setting and participants. PMID:24599577

  4. The Issues Framework: Situating Graduate Teaching Assistant-Student Interactions in Physics Problem Solving

    NASA Astrophysics Data System (ADS)

    Westlander, Meghan Joanne

    Interactive engagement environments are critical to students' conceptual learning gains, and often the instructor is ultimately responsible for the creation of that environment in the classroom. When those instructors are graduate teaching assistants (GTAs), one of the primary ways in which they can promote interactive engagement is through their interactions with students. Much of the prior research on physics GTA-student interactions focuses on GTA training programs (e.g. Ezrailson (2004); Smith, Ward, and Rosenshein (1977)) or on GTAs' specific actions and beliefs (e.g. West, Paul, Webb, and Potter (2013); Goertzen (2010); Spike and Finkelstein (2012a)). Research on students' ideas and behaviors within and surrounding those interactions is limited but important to obtaining a more complete understanding of how GTAs promote an interactive environment. In order to begin understanding this area, I developed the Issues Framework to examine how GTA-student interactions are situated in students' processes during physics problem solving activities. Using grounded theory, the Issues Framework emerged from an analysis of the relationships between GTA-student interactions and the students procedures and expressions of physics content in and surrounding those interactions. This study is focused on introducing the Issues Framework and the insight it can provide into GTA-student interactions and students' processes. The framework is general in nature and has a visually friendly design making it a useful tool for consolidating complex data and quickly pattern-matching important pieces of a complex process. Four different categories of Issues emerged spanning the problem solving process: (1) Getting Started, (2) Solution Approach, (3) Unit Conversions, and (4) Other. The framework allowed for identification of the specific contents of the Issues in each category as well as revealing the common stories of students' processes and how the interactions were situated in those

  5. Effects of representation on students solving physics problems: A fine-grained characterization

    NASA Astrophysics Data System (ADS)

    Kohl, Patrick B.; Finkelstein, Noah D.

    2006-06-01

    Recent papers document that student problem-solving competence varies (often strongly) with representational format, and that there are significant differences between the effects that traditional and reform-based instructional environments have on these competences [Kohl and Finkelstein, Phys. Rev. ST Phys. Educ. Res. 1, 010104 (2005); Kohl and Finkelstein, Phys. Rev. ST Phys. Educ. Res. 2, 010102 (2006)]. These studies focused on large-lecture introductory physics courses, and included aggregate data on student performance on quizzes and homeworks. In this paper, we complement previous papers with finer-grained in-depth problem-solving interviews. In 16 interviews of students drawn from these classes, we investigate in more detail how and when student problem-solving performance varies with problem representation (verbal, mathematical, graphical, or pictorial). We find that student strategy often varies with representation, and that in this environment students who show more strategy variation tend to perform more poorly. We also verify that student performance depends sensitively on the particular combination of representation, topic, and student prior knowledge. Finally, we confirm that students have generally robust opinions of their representational skills, and that these opinions correlate poorly with their actual performances.

  6. How Indirect Supportive Digital Help during and after Solving Physics Problems Can Improve Problem-Solving Abilities

    ERIC Educational Resources Information Center

    Pol, Henk J.; Harskamp, Egbert G.; Suhre, Cor J. M.; Goedhart, Martin J.

    2009-01-01

    This study investigates the effectiveness of computer-delivered hints in relation to problem-solving abilities in two alternative indirect instruction schemes. In one instruction scheme, hints are available to students immediately after they are given a new problem to solve as well as after they have completed the problem. In the other scheme,…

  7. Impact of Guided Reflection with Peers on the Development of Effective Problem Solving Strategies and Physics Learning

    NASA Astrophysics Data System (ADS)

    Mason, Andrew J.; Singh, Chandralekha

    2016-05-01

    Students must learn effective problem solving strategies in order to develop expertise in physics. Effective problem solving strategies include a conceptual analysis of the problem followed by planning of the solution, and then implementation, evaluation, and reflection upon the process. Research suggests that converting a problem from the initial verbal representation to other suitable representation, e.g., diagrammatic representation, during the initial conceptual analysis can facilitate further analysis of the problem. But without guidance, many introductory physics students solve problems using superficial clues and cues and do not perceive problem solving as an opportunity for learning. Here, we describe a study that suggests that engaging students in reflection with peers about effective problem solving strategies while effective approaches are modeled for them and prompt feedback is provided may enhance desirable skills.

  8. The Type Ia Supernova Pipeline for the Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS)

    NASA Astrophysics Data System (ADS)

    Siffert, B. B.; Reis, R. R. R.; Calvão, M. O.

    2014-10-01

    The Javalambre Physics of the Accelerating Universe Astrophysical Survey (J-PAS) is an astronomical facility being built in Sierra de Javalambre, Spain. The main goal is to study the expansion of the Universe through different cosmological observables such as baryonic acoustic oscillations, type Ia supernovae and galaxy clusters. The main instrument will be a 2.5 m telescope equipped with a system of 56 narrow band filters in the optical. Here we present a sketch of the pipeline we are developing to detect type Ia supernovae with J-PAS. First we describe each individual step of the pipeline, such as image subtraction and source selection. Then we show some results we obtained when applying our pipeline to images from the Sloan Digital Sky Survey and the ALHAMBRA survey, which had a set of narrow band filters similar to the ones that will be used by J-PAS.

  9. THE RHIC INJECTOR ACCELERATORS CONFIGURATIONS, AND PERFORMANCE FOR THE RHIC 2003 AU - D PHYSICS RUN.

    SciTech Connect

    Ahrens, L; Benjamin, J; Blaskiewicz, M; Brennan, J M; Brown, K A; Carlson, K A; Delong, J; D' Ottavio, T; Frak, B; Gardner, C J; Glenn, J W; Harvey, M; Hayes, T; Hseuh, H- C; Ingrassia, P; Lowenstein, D; Mackay, W; Marr, G; Morris, J; Roser, T; Satogata, T; Smith, G; Smith, K S; Steski, D; Tsoupas, N; Thieberger, P; Zeno, K

    2003-05-12

    The RHIC 2003 Physics Run [1] required collisions between gold ions and deuterons. The injector necessarily had to deliver adequate quality (transverse and longitudinal emittance) and quantity of both species. For gold this was a continuing evolution from past work [2]. For deuterons it was new territory. For the filling of the RHIC the injector not only had to deliver quality beams but also had to switch between these species quickly. This paper details the collider requirements and our success in meeting these. Some details of the configurations employed are given.

  10. Accelerator beam data commissioning equipment and procedures: Report of the TG-106 of the Therapy Physics Committee of the AAPM

    SciTech Connect

    Das, Indra J.; Cheng, C.-W.; Watts, Ronald J.; Ahnesjoe, Anders; Gibbons, John; Li, X. Allen; Lowenstein, Jessica; Mitra, Raj K.; Simon, William E.; Zhu, Timothy C.

    2008-09-15

    For commissioning a linear accelerator for clinical use, medical physicists are faced with many challenges including the need for precision, a variety of testing methods, data validation, the lack of standards, and time constraints. Since commissioning beam data are treated as a reference and ultimately used by treatment planning systems, it is vitally important that the collected data are of the highest quality to avoid dosimetric and patient treatment errors that may subsequently lead to a poor radiation outcome. Beam data commissioning should be performed with appropriate knowledge and proper tools and should be independent of the person collecting the data. To achieve this goal, Task Group 106 (TG-106) of the Therapy Physics Committee of the American Association of Physicists in Medicine was formed to review the practical aspects as well as the physics of linear accelerator commissioning. The report provides guidelines and recommendations on the proper selection of phantoms and detectors, setting up of a phantom for data acquisition (both scanning and no-scanning data), procedures for acquiring specific photon and electron beam parameters and methods to reduce measurement errors (<1%), beam data processing and detector size convolution for accurate profiles. The TG-106 also provides a brief discussion on the emerging trend in Monte Carlo simulation techniques in photon and electron beam commissioning. The procedures described in this report should assist a qualified medical physicist in either measuring a complete set of beam data, or in verifying a subset of data before initial use or for periodic quality assurance measurements. By combining practical experience with theoretical discussion, this document sets a new standard for beam data commissioning.

  11. Accelerator beam data commissioning equipment and procedures: report of the TG-106 of the Therapy Physics Committee of the AAPM.

    PubMed

    Das, Indra J; Cheng, Chee-Wai; Watts, Ronald J; Ahnesjö, Anders; Gibbons, John; Li, X Allen; Lowenstein, Jessica; Mitra, Raj K; Simon, William E; Zhu, Timothy C

    2008-09-01

    For commissioning a linear accelerator for clinical use, medical physicists are faced with many challenges including the need for precision, a variety of testing methods, data validation, the lack of standards, and time constraints. Since commissioning beam data are treated as a reference and ultimately used by treatment planning systems, it is vitally important that the collected data are of the highest quality to avoid dosimetric and patient treatment errors that may subsequently lead to a poor radiation outcome. Beam data commissioning should be performed with appropriate knowledge and proper tools and should be independent of the person collecting the data. To achieve this goal, Task Group 106 (TG-106) of the Therapy Physics Committee of the American Association of Physicists in Medicine was formed to review the practical aspects as well as the physics of linear accelerator commissioning. The report provides guidelines and recommendations on the proper selection of phantoms and detectors, setting up of a phantom for data acquisition (both scanning and no-scanning data), procedures for acquiring specific photon and electron beam parameters and methods to reduce measurement errors (<1%), beam data processing and detector size convolution for accurate profiles. The TG-106 also provides a brief.discussion on the emerging trend in Monte Carlo simulation techniques in photon and electron beam commissioning. The procedures described in this report should assist a qualified medical physicist in either measuring a complete set of beam data, or in verifying a subset of data before initial use or for periodic quality assurance measurements. By combining practical experience with theoretical discussion, this document sets a new standard for beam data commissioning. PMID:18841871

  12. Problem drinking and physical intimate partner violence against women: evidence from a national survey in Uganda

    PubMed Central

    2012-01-01

    Background Problem drinking has been identified as a major risk factor for physical intimate partner violence (PIPV) in many studies. However, few studies have been carried on the subject in developing countries and even fewer have a nationwide perspective. This paper assesses the patterns and levels of PIPV against women and its association with problem drinking of their sexual partners in a nationwide survey in Uganda. Methods The data came from the women’s dataset in the Uganda Demographic and Health Survey of 2006. Problem drinking among sexual partners was defined by women’s reports that their partner got drunk sometimes or often and served as the main independent variable while experience of PIPV by the women was the main dependent variable. In another aspect problem drinking was treated an ordinal variable with levels ranging from not drinking to getting drunk often. A woman was classified as experiencing PIPV if her partner pushed or shook her; threw something at her; slapped her; pushed her with a fist or a harmful object; kicked or dragged her, tried to strangle or burn her; threatened/attacked her with a knife/gun or other weapon. General chi-square and chi-square for trend analyses were used to assess the significance of the relationship between PIPV and problem drinking. Multivariate analysis was applied to establish the significance of the relationship of the two after controlling for key independent factors. Results Results show that 48% of the women had experienced PIPV while 49.5% reported that their partners got drunk at least sometimes. The prevalence of both PIPV and problem drinking significantly varied by age group, education level, wealth status, and region and to a less extent by occupation, type of residence, education level and occupation of the partner. Women whose partners got drunk often were 6 times more likely to report PIPV (95% CI: 4.6-8.3) compared to those whose partners never drank alcohol. The higher the education level of

  13. Physical Child Abuse and Teacher Harassment and Their Effects on Mental Health Problems Amongst Adolescent Bully-Victims in Taiwan.

    PubMed

    Yen, Cheng-Fang; Ko, Chih-Hung; Liu, Tai-Ling; Hu, Huei-Fan

    2015-10-01

    This study compared physical child abuse and teacher harassment of bully-victims with other groups and examined their associations with mental health problems in bully-victims. For 6,160 adolescents, experiences of physical child abuse, teacher harassment, peer bullying, and six mental health problem indicators were assessed. Adolescents that had experienced physical child abuse and teacher harassment were more likely to be bully-victims but not neutral or pure victims. Adolescents who reported physical child abuse were more likely to be bully-victims but not pure bullies. Bully-victims that had experienced teacher harassment exhibited more severe depression and insomnia than did those without teacher harassment. Gender had moderating effects on the difference in physical child abuse between bully-victims and neutrals and on the association between physical child abuse and suicidality in bully-victims. Physical child abuse and teacher harassment should be considered when preventive and intervention programs are developed for adolescents. PMID:25300192

  14. How do they solve it? An insight into the learner's approach to the mechanism of physics problem solving

    NASA Astrophysics Data System (ADS)

    Hegde, Balasubrahmanya; Meera, B. N.

    2012-06-01

    A perceived difficulty is associated with physics problem solving from a learner’s viewpoint, arising out of a multitude of reasons. In this paper, we have examined the microstructure of students’ thought processes during physics problem solving by combining the analysis of responses to multiple-choice questions and semistructured student interviews. Design of appropriate scaffoldings serves as pointers to the identification of student problem solving difficulties. An analysis of the results suggests the necessity of identification of the skill sets required for developing better problem solving abilities.

  15. Physical and mechanical metallurgy of high purity Nb for accelerator cavities

    SciTech Connect

    Bieler, T. R.; Wright, N. T.; Pourboghrat, F.; Compton, C.; Hartwig, K. T.; Baars, D.; Zamiri, A.; Chandrasekaran, S.; Darbandi, P.; Jiang, H.; Skoug, E.; Balachandran, S.; Ice, Gene E; Liu, W.

    2010-01-01

    In the past decade, high Q values have been achieved in high purity Nb superconducting radio frequency (SRF) cavities. Fundamental understanding of the physical metallurgy of Nb that enables these achievements is beginning to reveal what challenges remain to establish reproducible and cost-effective production of high performance SRF cavities. Recent studies of dislocation substructure development and effects of recrystallization arising from welding and heat treatments and their correlations with cavity performance are considered. With better fundamental understanding of the effects of dislocation substructure evolution and recrystallization on electron and phonon conduction, as well as the interior and surface states, it will be possible to design optimal processing paths for cost-effective performance using approaches such as hydroforming, which minimizes or eliminates welds in a cavity.

  16. Commons problems, common ground: Earth-surface dynamics and the social-physical interdisciplinary frontier

    NASA Astrophysics Data System (ADS)

    Lazarus, E.

    2015-12-01

    In the archetypal "tragedy of the commons" narrative, local farmers pasture their cows on the town common. Soon the common becomes crowded with cows, who graze it bare, and the arrangement of open access to a shared resource ultimately fails. The "tragedy" involves social and physical processes, but the denouement depends on who is telling the story. An economist might argue that the system collapses because each farmer always has a rational incentive to graze one more cow. An ecologist might remark that the rate of grass growth is an inherent control on the common's carrying capacity. And a geomorphologist might point out that processes of soil degradation almost always outstrip processes of soil production. Interdisciplinary research into human-environmental systems still tends to favor disciplinary vantages. In the context of Anthropocene grand challenges - including fundamental insight into dynamics of landscape resilience, and what the dominance of human activities means for processes of change and evolution on the Earth's surface - two disciplines in particular have more to talk about than they might think. Here, I use three examples - (1) beach nourishment, (2) upstream/downstream fluvial asymmetry, and (3) current and historical "land grabbing" - to illustrate a range of interconnections between physical Earth-surface science and common-pool resource economics. In many systems, decision-making and social complexity exert stronger controls on landscape expression than do physical geomorphological processes. Conversely, human-environmental research keeps encountering multi-scale, emergent problems of resource use made 'common-pool' by water, nutrient and sediment transport dynamics. Just as Earth-surface research can benefit from decades of work on common-pool resource systems, quantitative Earth-surface science can make essential contributions to efforts addressing complex problems in environmental sustainability.

  17. Status And Perspectives In Italian HEP With Accelerators

    SciTech Connect

    Ferroni, Fernando

    2005-10-12

    In this paper I give an overview on the status of elementary particle physics research performed with accelerators in INFN . Recent successes, potential problems and a look to the future are discussed.

  18. High energy plasma accelerators

    SciTech Connect

    Tajima, T.

    1985-05-01

    Colinear intense laser beams ..omega../sub 0/, kappa/sub 0/ and ..omega../sub 1/, kappa/sub 1/ shone on a plasma with frequency separation equal to the electron plasma frequency ..omega../sub pe/ are capable of creating a coherent large longitudinal electric field E/sub L/ = mc ..omega../sub pe//e of the order of 1GeV/cm for a plasma density of 10/sup 18/ cm/sup -3/ through the laser beat excitation of plasma oscillations. Accompanying favorable and deleterious physical effects using this process for a high energy beat-wave accelerator are discussed: the longitudinal dephasing, pump depletion, the transverse laser diffraction, plasma turbulence effects, self-steepening, self-focusing, etc. The basic equation, the driven nonlinear Schroedinger equation, is derived to describe this system. Advanced accelerator concepts to overcome some of these problems are proposed, including the plasma fiber accelerator of various variations. An advanced laser architecture suitable for the beat-wave accelerator is suggested. Accelerator physics issues such as the luminosity are discussed. Applications of the present process to the current drive in a plasma and to the excitation of collective oscillations within nuclei are also discussed.

  19. Resolving all-order method convergence problems for atomic physics applications

    SciTech Connect

    Gharibnejad, H.; Derevianko, A.; Eliav, E.; Safronova, M. S.

    2011-05-15

    The development of the relativistic all-order method where all single, double, and partial triple excitations of the Dirac-Hartree-Fock wave function are included to all orders of perturbation theory led to many important results for the study of fundamental symmetries, development of atomic clocks, ultracold atom physics, and others, as well as provided recommended values of many atomic properties critically evaluated for their accuracy for a large number of monovalent systems. This approach requires iterative solutions of the linearized coupled-cluster equations leading to convergence issues in some cases where correlation corrections are particularly large or lead to an oscillating pattern. Moreover, these issues also lead to similar problems in the configuration-interaction (CI)+all-order method for many-particle systems. In this work, we have resolved most of the known convergence problems by applying two different convergence stabilizer methods, namely, reduced linear equation and direct inversion of iterative subspace. Examples are presented for B, Al, Zn{sup +}, and Yb{sup +}. Solving these convergence problems greatly expands the number of atomic species that can be treated with the all-order methods and is anticipated to facilitate many interesting future applications.

  20. Effects of a Problem-Based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

    ERIC Educational Resources Information Center

    Becerra-Labra, Carlos; Gras-Marti, Albert; Torregrosa, Joaquin Martinez

    2012-01-01

    A model of teaching/learning is proposed based on a "problem-based structure" of the contents of the course, in combination with a training in paper and pencil problem solving that emphasizes discussion and quantitative analysis, rather than formulae plug-in. The aim is to reverse the high failure and attrition rate among engineering…