Science.gov

Sample records for accelerator physics problems

  1. Theoretical problems in accelerator physics. Progress report

    SciTech Connect

    Kroll, N.M.

    1993-08-01

    This report discusses the following topics in accelerator physics: radio frequency pulse compression and power transport; computational methods for the computer analysis of microwave components; persistent wakefields associated with waveguide damping of higher order modes; and photonic band gap cavities.

  2. (Advanced accelerator physics featuring the problems of small rings)

    SciTech Connect

    Olsen, D.K.

    1989-10-16

    The traveler attended the CERN Accelerator School and Uppsala University short course on Advanced Accelerator Physics held on the University campus, Uppsala, Sweden, from September 18-29, 1989. The course, attended by 81 people, was well conceived, well presented, and informative. The course was organized and specialized on the problems of small rings. The traveler also visited the CELSIUS ring facility of Uppsala University and the CRYRING ring facility of the Manne Siegbahn Institute in Stockholm, Sweden.

  3. 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.

  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 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.

  6. 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.

  7. 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

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. [Accelerator physics R&D

    SciTech Connect

    Krisch, A.D.

    1994-08-22

    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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Control problems in very large accelerators

    NASA Astrophysics Data System (ADS)

    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.

  4. 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.

  5. 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

  6. 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.

  7. A collection of problems for physics teaching

    NASA Astrophysics Data System (ADS)

    Gröber, S.; Jodl, H.-J.

    2010-07-01

    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, project-oriented learning and the use of remote labs/web experiments. We focus on Rutherford's scattering experiment, electron diffraction, Millikan's experiment and the use of pendulums to measure the dependence of gravitational acceleration on latitude. The collection contains about 50 problems with 160 subtasks and solutions, altogether 100 pages. Structure, content, range and the added value of the problems are described. The whole collection can be downloaded for free from http://rcl.physik.uni-kl.de.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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,…

  17. 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.

  18. 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.

  19. 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.

  20. 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).

  1. 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.

  2. 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).

  3. 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…

  4. 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.

  5. 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.

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

    DOE PAGES

    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

  7. 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…

  8. 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…

  9. 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.

  10. 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.

  11. Linear Collider Accelerator Physics Issues Regarding Alignment

    SciTech Connect

    Seeman, J.T.; /SLAC

    2005-08-12

    The next generation of linear colliders will require more stringent alignment tolerances than those for the SLC with regard to the accelerating structures, quadrupoles, and beam position monitors. New techniques must be developed to achieve these tolerances. A combination of mechanical-electrical and beam-based methods will likely be needed.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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…

  20. Fundamentals of Physics, Problem Supplement No. 1

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2000-05-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving.

  1. 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.

  2. 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…

  3. 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,…

  4. 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…

  5. 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…

  6. 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.

  7. 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)

  8. 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.

  9. 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.

  10. 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.

  11. [Physical inactivity as public health problem].

    PubMed

    Kovacić, Luka

    2007-01-01

    The aim of the paper is to present the public health aspects of physical inactivity, and the importance of sport, recreation and other types of physical activity to health of population. Reduction of physical inactivity in today's every day life became great public health concern. The causes of such situation are linked to the pattern of modern life, sedentary type of work, autoimmunization in production, passive role of citizens in sports, and others. Adequate physical activity is very important means in prevention of many health problems, like obesity, arterial hypertension, diabetes, hearth diseases, atherosclerosis, osteoporosis and others. Physical activity and regular exercises in elderly increase independency from others in every day living, increase physical condition and reduce accidents, improve mental health, satisfaction with life; reduce hypertension and quantity of drugs. Physical inactivity increases economic burden of the country. The results of the Croatian Health Survey from 2003, done on representative sample of Croatian adult population shows that 44% of men and 30% of women are physically inactive. Situation in cities is even worse. In Zagreb 85% of men and 45% of women are inactive. The criteria for physical active person were walking three times a week for 30 minutes at least. The solution of the problem for the future is to pay more and more intensive attention to develop comprehensive community programs. More support should be given in construction of facilities for sport and recreation, during wintertime and for persons with special needs. The key role and responsibility for the promotion of physical activity of citizens will have primary health services (family practitioners, public health services), nongovernmental organization and media.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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

  18. 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.

  19. 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.

  20. Accelerator physics highlights in the 1997/98 SLC run

    SciTech Connect

    Assmann, R.W.; Bane, K.L.F.; Barkow, T.

    1998-03-01

    The authors report various accelerator physics studies and improvements from the 1997/98 run at the Stanford Linear Collider (SLC). In particular, the authors discuss damping-ring lattice diagnostics, changes to the linac set up, fast control for linac rf phase stability, new emittance tuning strategies, wakefield reduction, modifications of the final-focus optics, longitudinal bunch shaping, and a novel spot-size control at the interaction point (IP).

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Inverse Problems in Classical and Quantum Physics

    NASA Astrophysics Data System (ADS)

    Almasy, Andrea A.

    2009-12-01

    The subject of this thesis is in the area of Applied Mathematics known as Inverse Problems. Inverse problems are those where a set of measured data is analysed in order to get as much information as possible on a model which is assumed to represent a system in the real world. We study two inverse problems in the fields of classical and quantum physics: QCD condensates from tau-decay data and the inverse conductivity problem. We use a functional method which allows us to extract within rather general assumptions phenomenological parameters of QCD (the condensates) from a comparison of the time-like experimental data with asymptotic space-like results from theory. The price to be paid for the generality of assumptions is relatively large errors in the values of the extracted parameters. Although we do not claim that our method is superior to other approaches, we hope that our results lend additional confidence to the numerical results obtained with the help of methods based on QCD sum rules. In this thesis, also two approaches of EIT image reconstruction are proposed. The first is based on reformulating the inverse problem in terms of integral equations. This method uses only a single set of measurements for the reconstruction. The second approach is an algorithm based on linearisation which uses more then one set of measurements. A promising result is that one can qualitatively reconstruct the conductivity inside the cross-section of a human chest. Even though the human volunteer is neither two-dimensional nor circular, such reconstructions can be useful in medical applications: monitoring for lung problems such as accumulating fluid or a collapsed lung and noninvasive monitoring of heart function and blood flow.

  8. Metric-Field Approach to Gravitation and the Problem of the Universe Acceleration

    NASA Astrophysics Data System (ADS)

    Verozub, Leonid V.

    2002-07-01

    A metric-field approach to gravitation is presented. It is based on an idea of dependency of space-time properties on measuring instruments. Some bimetric equations that realize this idea are considered. They were tested by the binary pulsar PSR1913+16. The spherically - symmetric solution of the equations has no event horizon and no physical singularity in the center. The proper energy of a point particle is finite. There can exist supermassive compact configurations of the degenerated Fermi-gas which can be identified with observed objects in galactic centers. The problem of the Universe acceleration has a natural explanation.

  9. 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.

  10. 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.

  11. Regional strategies for the accelerating global problem of groundwater depletion

    NASA Astrophysics Data System (ADS)

    Aeschbach-Hertig, Werner; Gleeson, Tom

    2012-12-01

    Groundwater--the world's largest freshwater resource--is critically important for irrigated agriculture and hence for global food security. Yet depletion is widespread in large groundwater systems in both semi-arid and humid regions of the world. Excessive extraction for irrigation where groundwater is slowly renewed is the main cause of the depletion, and climate change has the potential to exacerbate the problem in some regions. Globally aggregated groundwater depletion contributes to sea-level rise, and has accelerated markedly since the mid-twentieth century. But its impacts on water resources are more obvious at the regional scale, for example in agriculturally important parts of India, China and the United States. Food production in such regions can only be made sustainable in the long term if groundwater levels are stabilized. To this end, a transformation is required in how we value, manage and characterize groundwater systems. Technical approaches--such as water diversion, artificial groundwater recharge and efficient irrigation--have failed to balance regional groundwater budgets. They need to be complemented by more comprehensive strategies that are adapted to the specific social, economic, political and environmental settings of each region.

  12. 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

  13. 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)

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

    DOE PAGES

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

    2015-11-01

    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.

  15. 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.

  16. Underground Accelerators for Precise Nuclear Physics: LUNA and DIANA

    NASA Astrophysics Data System (ADS)

    Leitner, Daniela

    2011-05-01

    Current stellar model simulations are at a level of precision that uncertainties in the nuclear-reaction rates are becoming significant for theoretical predictions and for the analysis of observational signatures. To address several open questions in cosmology, astrophysics, and non-Standard-Model neutrino physics, new high precision measurements of direct-capture nuclear fusion cross sections will be essential. At these low energies, fusion cross sections decrease exponentially with energy and are expected to approach femtobarn levels or less. The experimental difficulties in determining the low-energy cross sections are caused by large background rates associated with cosmic ray-induced reactions, background from natural radioactivity in the laboratory environment, and the beam-induced background on target impurities. Natural background can be reduced by careful shielding of the target and detector environment, and beam-induced background can be reduced by active shielding techniques through event identification, but it is difficult to reduce the background component from cosmic ray muons. An underground location has the advantage that the cosmic ray-induced background is reduced by several orders of magnitude, allowing the measurements to be pushed to far lower energies than feasible above ground. This has been clearly demonstrated at LUNA by the successful studies of critical reactions in the pp-chains and first reaction studies in the CNO cycles. The DIANA project (Dakota Ion Accelerators for Nuclear Astrophysics) is a collaboration between the University of Notre Dame, Michigan State University, Colorado School of Mines, Regis University, University of North Carolina, Western Michigan University, and Lawrence Berkeley National Laboratory, to build a nuclear astrophysics accelerator facility deep underground. The DIANA accelerator facility is being designed to achieve large laboratory reaction rates by delivering two orders of magnitude higher ion beams to a

  17. 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.

  18. 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)

  19. Electrostatic double layers as auroral particle accelerators - a problem

    NASA Astrophysics Data System (ADS)

    Bryant, D. A.; Courtier, G. M.

    2015-04-01

    A search of the Annales Geophysicae database shows that double layers and other quasi-static electric potential structures have been invoked hundreds of times since the year 2000 as being the agents of auroral electron acceleration. This is despite the fact that energy transfer by conservative fields has been known for some 200 years to be impossible. Attention is drawn to a long-standing interpretation of the acceleration process in terms of the dynamic fields of electrostatic waves.

  20. 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.

  1. The Scanning Electron Microscope As An Accelerator For The Undergraduate Advanced Physics Laboratory

    SciTech Connect

    Peterson, Randolph S.; Berggren, Karl K.; Mondol, Mark

    2011-06-01

    Few universities or colleges have an accelerator for use with advanced physics laboratories, but many of these institutions have a scanning electron microscope (SEM) on site, often in the biology department. As an accelerator for the undergraduate, advanced physics laboratory, the SEM is an excellent substitute for an ion accelerator. Although there are no nuclear physics experiments that can be performed with a typical 30 kV SEM, there is an opportunity for experimental work on accelerator physics, atomic physics, electron-solid interactions, and the basics of modern e-beam lithography.

  2. University Physics As a Second Language: Mastering Problem Solving

    NASA Astrophysics Data System (ADS)

    Barrett, Tom

    2005-09-01

    Get a better grade in Physics Solving physics problems can be challenging at times. But with hard work and the right study tools, you can learn the language of physics and get the grade you want. With Tom Barrett's University Physics as a Second Language(TM): Mastering Problem Solving, you'll be able to better understand fundamental physics concepts, solve a variety of problems, and focus on what you need to know to succeed. Here's how you can get a better grade in physics: Understand the basic concepts University Physics as a Second Language(TM) focuses on selected topics in calculus-based physics to give you a solid foundation. Tom Barrett explains these topics in clear, easy-to-understand language. Break problems down into simple steps University Physics as a Second Language(TM) teaches you to approach problems more efficiently and effectively. You'll learn how to recognize common patterns in physics problems, break problems down into manageable steps, and apply appropriate techniques. The book takes you step-by-step through the solutions to numerous examples. Improve your problem-solving skills University Physics as a Second Language(TM) will help you develop the skills you need to solve a variety of problem types. You'll learn timesaving problem-solving strategies that will help you focus your efforts, as well as how to avoid potential pitfalls.

  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. Emerging Consensus in Novice Physics Problem Solving Research.

    ERIC Educational Resources Information Center

    Roth, Christopher; Chaiklin, Seth

    During the summer of 1986 a conference funded by the National Science Foundation (NSF) was organized to assess the current state of cognitive research on the psychology of physics problem solving, and to examine the needs of physics instructors and instructional designers that must be addressed by a psychological theory of physics problem solving.…

  5. 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.

  6. 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.

  7. Physics in 1975--New Problems and Insights

    ERIC Educational Resources Information Center

    Panofsky, Wolfgang K. H.

    1975-01-01

    Describes the decline in available physics positions in the academic areas. Indicates that the future need for physicists is unclear and states that the present federal funding patterns are not consistent with good practices of research and development. Summarizes new information in the field of elementary-particle physics. (GS)

  8. 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.…

  9. Solving Physics Problems--How Do We Do It?

    ERIC Educational Resources Information Center

    Fuller, Robert G.

    1982-01-01

    Discusses three avenues of problem-solving research: misconceiving natural laws, processing information, and constructing solutions. Suggests that the change in emphasis from problem to problem solver and the key role of "physics" problems are unifying aspects of the research. (JN)

  10. Skill Levels of Prospective Physics Teachers on Problem Posing

    ERIC Educational Resources Information Center

    Cildir, Sema; Sezen, Nazan

    2011-01-01

    Problem posing is one of the topics which the educators thoroughly accentuate. Problem posing skill is defined as an introvert activity of a student's learning. In this study, skill levels of prospective physics teachers on problem posing were determined and their views on problem posing were evaluated. To this end, prospective teachers were given…

  11. Harmony Theory: Problem Solving, Parallel Cognitive Models, and Thermal Physics.

    ERIC Educational Resources Information Center

    Smolensky, Paul; Riley, Mary S.

    This document consists of three papers. The first, "A Parallel Model of (Sequential) Problem Solving," describes a parallel model designed to solve a class of relatively simple problems from elementary physics and discusses implications for models of problem-solving in general. It is shown that one of the most salient features of problem solving,…

  12. Doing accelerator physics using SDDS, UNIX, and EPICS

    SciTech Connect

    Borland, M.; Emery, L.; Sereno, N.

    1995-12-31

    The use of the SDDS (Self-Describing Data Sets) file protocol, together with the UNIX operating system and EPICS (Experimental Physics and Industrial Controls System), has proved powerful during the commissioning of the APS (Advanced Photon Source) accelerator complex. The SDDS file protocol has permitted a tool-oriented approach to developing applications, wherein generic programs axe written that function as part of multiple applications. While EPICS-specific tools were written for data collection, automated experiment execution, closed-loop control, and so forth, data processing and display axe done with the SDDS Toolkit. Experiments and data reduction axe implemented as UNIX shell scripts that coordinate the execution of EPICS specific tools and SDDS tools. Because of the power and generic nature of the individual tools and of the UNIX shell environment, automated experiments can be prepared and executed rapidly in response to unanticipated needs or new ideas. Examples are given of application of this methodology to beam motion characterization, beam-position-monitor offset measurements, and klystron characterization.

  13. Review of Basic Physics of Laser-Accelerated Charged-Particle Beams

    SciTech Connect

    Suk, H.; Hur, M. S.; Jang, H.; Kim, J.

    2007-07-11

    Laser-plasma wake wave can accelerate charged particles, especially electrons with an enormously large acceleration gradient. The electrons in the plasma wake wave have complicated motions in the longitudinal and transverse directions. In this paper, basic physics of the laser-accelerated electron beam is reviewed.

  14. 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.

  15. 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)

  16. 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

  17. 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…

  18. 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…

  19. Structured Collaboration versus Individual Learning in Solving Physics Problems

    NASA Astrophysics Data System (ADS)

    Harskamp, Egbert; Ding, Ning

    2006-11-01

    The research issue in this study is how to structure collaborative learning so that it improves solving physics problems more than individual learning. Structured collaborative learning has been compared with individual learning environments with Schoenfeld’s problem-solving episodes. Students took a pre-test and a post-test and had the opportunity to solve six physics problems. Ninety-nine students from a secondary school in Shanghai participated in the study. Students who learnt to solve problems in collaboration and students who learnt to solve problems individually with hints improved their problem-solving skills compared with those who learnt to solve the problems individually without hints. However, it was hard to discern an extra effect for students working collaboratively with hints—although we observed these students working in a more structured way than those in the other groups. We discuss ways to further investigate effective collaborative processes for solving physics problems.

  20. 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.

  1. 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…

  2. 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)

  3. 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…

  4. 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…

  5. Fundamental Problems in the Unification of Physics

    NASA Astrophysics Data System (ADS)

    Heller, Michael; Pysiak, Leszek; Sasin, Wiesław

    2011-05-01

    We discuss the following problems, plaguing the present search for the "final theory": (1) How to find a mathematical structure rich enough to be suitably approximated by the mathematical structures of general relativity and quantum mechanics? (2) How to reconcile nonlocal phenomena of quantum mechanics with time honored causality and reality postulates? (3) Does the collapse of the wave function contain some hints concerning the future quantum gravity theory? (4) It seems that the final theory cannot avoid the problem of dynamics, and consequently the problem of time. What kind of time, if this theory is supposed to be background free? (5) Will the dynamics of the "final theory" be probabilistic? Quantum probability exhibits some essential differences as compared with classical probability; are they but variations of some more general probabilistic measure theory? (6) Do we need a radically new interpretation of quantum mechanics, or rather an entirely new theory of which the present quantum mechanics is an approximation? (7) If the final theory is to be background free, it should provide a mechanism of space-time generation. Should we try to explain not only the generation of space-time, but also the generation of its material content? (8) As far as the existence of the initial singularity is concerned, one usually expects either "yes" or "not" answers from the final theory. However, if the mathematical structure of the future theory is supposed to be truly more general that the mathematical structures of the present general relativity and quantum mechanics, is a "third answer" possible? Could this third answer be related to the probabilistic character of the final theory? We discuss these questions in the framework of a working model unifying gravity and quanta. The analysis reveals unexpected aspects of these rather wildly discussed issues.

  6. METHODOLOGICAL NOTES: Unsolved problems in fundamental physics

    NASA Astrophysics Data System (ADS)

    Ginzburg, Il'ya F.

    2009-05-01

    Recent years have added very much to our knowledge of the structure of the Universe and elementary interactions which, combined with the critical rethinking of long-known results and ideas, gives considerable topical relevance to the questions listed in this paper. Compiling this list, the author had no notion of any targeting and the typical 'WHAT FOR' and 'WHY' questions were considered as mere abbreviations for "Does a (possibly yet unknown) law of Nature exist with which the property or phenomenon under study can be explained?" The list of problems reflects the scientific interests of the author and so does not claim to be comprehensive.

  7. 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.

  8. Medical physics--particle accelerators--the beginning.

    PubMed

    Ganz, Jeremy C

    2014-01-01

    This chapter outlines the early development of particle accelerators with the redesign from linear accelerator to cyclotron by Ernest Lawrence with a view to reducing the size of the machines as the power increased. There are minibiographies of Ernest Lawrence and his brother John. The concept of artificial radiation is outlined and the early attempts at patient treatment are mentioned. The reasons for trying and abandoning neutron therapy are discussed, and the early use of protons is described.

  9. Exciting physical problems for the near future

    NASA Astrophysics Data System (ADS)

    Greiner, W.

    2014-09-01

    A review of the pseudo-complex theory of General Relativity will be given. The theory implies the existence of a minimal length. Modifying the variational principle did lead to a contribution of a dark energy-momentum tensor on the right hand side of the Einstein equations. A physical principle emerges from it: Mass not only curves the space but also modifies the vacuum properties around that mass. The dark energy contributions react back on the curvature of space, halting the collapse of any size of mass, and finally the event horizon disappears. For the dark energy contribution a model had to be used, due to the lack of a quantized quantum theory. We resumed some experimental predictions, neglecting the effects of the minimal length.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. Physics Problem Solving: Student Performance Analysis on Mechanics Problems Requiring Diagrammatic Visualisation.

    ERIC Educational Resources Information Center

    Prendergast, Wilfred Francis

    This study investigated problem solving skills in mechanics problems that required the use of diagrams. These skills were examined in two ways. First, the study examined student problem solving skills using solution scripts from the Western Australian Tertiary Admission Examination in physics. Solution attempts by students in the 1978 and 1979…

  18. 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.…

  19. 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…

  20. 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.

  1. CEBAF: The Continuous Electron Beam Accelerator Facility and its Physics Program

    SciTech Connect

    Mougey, Jean

    1992-01-01

    With the 4 GeV Continuous Electron Beam Accelerator Facility presently under construction in Newport News, Virginia, a new domain of nuclear and subnuclear phenomena can be investigated, mainly through coincidence experiments. An overview of the characteristic features of the accelerator and associated experimental equipment is given. Some examples of the physics programs are briefly described.

  2. 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…

  3. 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…

  4. Representation Use and Strategy Choice in Physics Problem Solving

    ERIC Educational Resources Information Center

    De Cock, Mieke

    2012-01-01

    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…

  5. 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)

  6. 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".

  7. Cognitive Science: Problem Solving And Learning For Physics Education

    NASA Astrophysics Data System (ADS)

    Ross, Brian H.

    2007-11-01

    Cognitive Science has focused on general principles of problem solving and learning that might be relevant for physics education research. This paper examines three selected issues that have relevance for the difficulty of transfer in problem solving domains: specialized systems of memory and reasoning, the importance of content in thinking, and a characterization of memory retrieval in problem solving. In addition, references to these issues are provided to allow the interested researcher entries to the literatures.

  8. Physics design of an accelerator for an accelerator-driven subcritical system

    NASA Astrophysics Data System (ADS)

    Li, Zhihui; Cheng, Peng; Geng, Huiping; Guo, Zhen; He, Yuan; Meng, Cai; Ouyang, Huafu; Pei, Shilun; Sun, Biao; Sun, Jilei; Tang, Jingyu; Yan, Fang; Yang, Yao; Zhang, Chuang; Yang, Zheng

    2013-08-01

    An accelerator-driven subcritical system (ADS) program was launched in China in 2011, which aims to design and build an ADS demonstration facility with the capability of more than 1000 MW thermal power in multiple phases lasting about 20 years. The driver linac is defined to be 1.5 GeV in energy, 10 mA in current and in cw operation mode. To meet the extremely high reliability and availability, the linac is designed with much installed margin and fault tolerance, including hot-spare injectors and local compensation method for key element failures. The accelerator complex consists of two parallel 10-MeV injectors, a joint medium-energy beam transport line, a main linac, and a high-energy beam transport line. The superconducting acceleration structures are employed except for the radio frequency quadrupole accelerators (RFQs) which are at room temperature. The general design considerations and the beam dynamics design of the driver linac complex are presented here.

  9. Accelerator Preparations for Muon Physics Experiments at Fermilab

    SciTech Connect

    Syphers, M.J.; /Fermilab

    2009-10-01

    The use of existing Fermilab facilities to provide beams for two muon experiments - the Muon to Electron Conversion Experiment (Mu2e) and the New g-2 Experiment - is under consideration. Plans are being pursued to perform these experiments following the completion of the Tevatron Collider Run II, utilizing the beam lines and storage rings used today for antiproton accumulation without considerable reconfiguration. Operating scenarios being investigated and anticipated accelerator improvements or reconfigurations will be presented.

  10. 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).

  11. 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.

  12. 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.

  13. 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. )

  14. 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.

  15. 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…

  16. Partially specified physics problems: university students' attitudes and performance

    NASA Astrophysics Data System (ADS)

    Marušić, M.; Erceg, N.; Sliško, J.

    2011-05-01

    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 of the problem is such that it does not give students any explicit advice regarding what to calculate or how to judge the feasibility of the given situation in the real world. The research was carried out using a structured written exam method. The worksheet was structured in order to assess explicitly a few elements of the students' problem-solving performance. Based on their results, the examinees were classified into four categories, depending on what they could or could not accomplish during problem solving. A majority of students were not able to solve the given physical problem completely. A selection of students' and professors' observations is also included. Our results show that traditionally formulated numerical exercises, which are mostly used in physics teaching, do not develop students' abilities in higher-order thinking (i.e. planning, decision making or result evaluation) to a desirable extent. We suggest that partially specified problems should be given to students, both in problem-solving sessions and exams, in order to prepare them for dealing with ill-structured tasks in real life.

  17. Accelerator physics of the Stanford Linear Collider and SLC accelerator experiments towards the Next Linear Collider

    SciTech Connect

    Seeman, J.T.

    1992-06-01

    The Stanford Linear Collider (SLC) was built to collide single bunches of electrons and positrons head-on at a single interaction point with single beam energies up to 55 GeV. The small beam sizes and high currents required for high luminosity operation have significantly pushed traditional beam quality limits. The Polarized Electron Source produces about 8 {times} 10{sup 10} electrons in each of two bunches with up to 28% polarization,. The Damping Rings provide coupled invariant emittances of 1.8 {times} 10{sup {minus}5} r-m with 4.5 {times} 10{sup 10} particles per bunch. The 57 GeV Linac has successfully accelerated over 3 {times} 10{sup 10} particles with design invariant emittances of 3 {times} 10{sup {minus}5} r-m. Both longitudinal and transverse wakefields affect strongly the trajectory and emittance corrections used for operations. The Arc systems routinely transport decoupled and betatron matched beams. In the Final Focus, the beams are chromatically corrected and demagnified producing spot sizes of 2 to 3 {mu}m at the focal point. Spot sizes below 2 {mu}m have been made during special tests. Instrumentation and feedback systems are well advanced, providing continuous beam monitoring and pulse-by-pulse control. A luminosity of 1.6 {times} 10{sup 29} cm{sup {minus}2}sec{sup {minus}1} has been produced. Several experimental tests for a Next Linear Collider (NLC) are being planned or constructed using the SLC accelerator as a test facility. The Final Focus Test Beam will demagnify a flat 50 GeV electron beam to dimensions near 60 nm vertically and 900 nm horizontally. A potential Emittance Dynamics Test Area has the capability to test the acceleration and transport of very low emittance beams, the compression of bunch lengths to 50 {mu}m, the acceleration and control of multiple bunches, and the properties of wakefields in the very short bunch length regime.

  18. 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.

  19. Physics at the Thomas Jefferson National Accelerator Facility

    SciTech Connect

    Lawrence Cardman

    2005-10-22

    The CEBAF accelerator at JLab is fulfilling its scientific mission to understand how hadrons are constructed from the quarks and gluons of QCD, to understand the QCD basis for the nucleon-nucleon force, and to explore the transition from the nucleon-meson to a QCD description. Its success is based on the firm foundation of experimental and theoretical techniques developed world-wide over the past few decades, on complementary data provided by essential lower-energy facilities, such as MAMI, and on the many insights provided by the scientists we are gathered here to honor.

  20. Designing and using multiple-possibility physics problems in physics courses

    NASA Astrophysics Data System (ADS)

    Shekoyan, Vazgen

    2012-02-01

    One important aspect of physics instruction is helping students develop better problem solving expertise. Besides enhancing the content knowledge, problems help students develop different cognitive abilities and skills. This presentation focuses on multiple-possibility problems (alternatively called ill-structured problems). These problems are different from traditional ``end of chapter'' single-possibility problems. They do not have one right answer and thus the student has to examine different possibilities, assumptions and evaluate the outcomes. To solve such problems one has to engage in a cognitive monitoring called epistemic cognition. It is an important part of thinking in real life. Physicists routinely use epistemic cognition when they solve problems. I have explored the instructional value of using such problems in introductory physics courses.

  1. 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

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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

  7. Hadron physics at the new CW electron accelerators

    SciTech Connect

    Burkert, V.D.

    1990-01-01

    Major trends of the physics program related to the study of hadron structure and hadron spectroscopy at the new high current, high duty cycle electron machines are discussed. It is concluded that planned experiments at these machines may have important impact on our understanding of the strong interaction by studying the internal structure and spectroscopy of the nucleon and lower mass hyperon states.

  8. 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.

  9. Internet computer coaches for introductory physics problem solving

    NASA Astrophysics Data System (ADS)

    Xu Ryan, Qing

    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 educational system, national studies have shown that the majority of students emerge from such courses having made little progress toward developing good problem-solving skills. The Physics Education Research Group at the University of Minnesota has been developing Internet computer coaches to help students become more expert-like problem solvers. During the Fall 2011 and Spring 2013 semesters, the coaches were introduced into large sections (200+ students) of the calculus based introductory mechanics course at the University of Minnesota. This dissertation, will address the research background of the project, including the pedagogical design of the coaches and the assessment of problem solving. The methodological framework of conducting experiments will be explained. The data collected from the large-scale experimental studies will be discussed from the following aspects: the usage and usability of these coaches; the usefulness perceived by students; and the usefulness measured by final exam and problem solving rubric. It will also address the implications drawn from this study, including using this data to direct future coach design and difficulties in conducting authentic assessment of problem-solving.

  10. 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.

  11. Fundamentals of Physics, Extended, Chapters 1 - 45 , Enhanced Problems Version

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2002-04-01

    No other book on the market today can match the success of Halliday, Resnick and Walker's Fundamentals of Physics! In a breezy, easy-to-understand style the book offers a solid understanding of fundamental physics concepts, and helps readers apply this conceptual understanding to quantitative problem solving. The extended edition provides coverage of developments in Physics in the last 100 years, including: Einstein and Relativity, Bohr and others and Quantum Theory, and the more recent theoretical developments like String Theory. This book offers a unique combination of authoritative content and stimulating applications.

  12. 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.

  13. 'Accelerators and Beams,' multimedia computer-based training in accelerator physics

    SciTech Connect

    Silbar, R. R.; Browman, A. A.; Mead, W. C.; Williams, R. A.

    1999-06-10

    We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user's rate of learning and length of retention of the material. They integrate interactive 'On-Screen Laboratories,' hypertext, line drawings, photographs, two- and three-dimensional animations, video, and sound. They target a broad audience, from undergraduates or technicians to professionals. Presently, three modules have been published (Vectors, Forces, and Motion), a fourth (Dipole Magnets) has been submitted for review, and three more exist in prototype form (Quadrupoles, Matrix Transport, and Properties of Charged-Particle Beams). Participants in the poster session will have the opportunity to try out these modules on a laptop computer.

  14. 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

  15. 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

  16. Compressed modes for variational problems in mathematics and physics.

    PubMed

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

    2013-11-12

    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.

  17. 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…

  18. 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…

  19. 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…

  20. 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.

  1. 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.

  2. From electron maps to acceleration models in the physics of flare

    NASA Astrophysics Data System (ADS)

    Massone, Anna Maria

    Electron maps reconstructed from RHESSI visibilities represent a powerful source of information for constraining models of electron acceleration in solar plasma physics during flaring events. In this talk I will describe how and to which extent electron maps can be utilized to estimate local electron spectral indices, the evolution of centroid position at different energies in the electron space and the compatibility of RHESSI observations with different theoretical models for the acceleration mechanisms.

  3. 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.

  4. 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.

  5. Physics design and scaling of recirculating induction accelerators: from benchtop prototypes to drivers

    SciTech Connect

    Barnard, J.J.; Cable, M.D.; Callahan, D.A.

    1996-02-06

    Recirculating induction accelerators (recirculators) have been investigated as possible drivers for inertial fusion energy production because of their potential cost advantage over linear induction accelerators. Point designs were obtained and many of the critical physics and technology issues that would need to be addressed were detailed. A collaboration involving Lawrence Livermore National Laboratory and Lawrence Berkeley National Laboratory researchers is now developing a small prototype recirculator in order to demonstrate an understanding of nearly all of the critical beam dynamics issues that have been raised. We review the design equations for recirculators and demonstrate how, by keeping crucial dimensionless quantities constant, a small prototype recirculator was designed which will simulate the essential beam physics of a driver. We further show how important physical quantities such as the sensitivity to errors of optical elements (in both field strength and placement), insertion/extraction, vacuum requirements, and emittance growth, scale from small-prototype to driver-size accelerator.

  6. 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.

  7. ACCELERATOR PHYSICS ISSUES FOR FUTURE ELECTRON ION COLLIDERS.

    SciTech Connect

    PEGGS,S.; BEN-ZVI,I.; KEWISCH,J.; MURPHY,J.

    2001-06-18

    Interest continues to grow in the physics of collisions between electrons and heavy ions, and between polarized electrons and polarized protons [1,2,3]. Table 1 compares the parameters of some machines under discussion. DESY has begun to explore the possibility of upgrading the existing HERA-p ring to store heavy ions, in order to collide them with electrons (or positrons) in the HERA-e ring, or from TESLA [4]. An upgrade to store polarized protons in the HERA-p ring is also under discussion [1]. BNL is considering adding polarized electrons to the RHIC repertoire, which already includes heavy and light ions, and polarized protons. The authors of this paper have made a first pass analysis of this ''eRHIC'' possibility [5]. MIT-BATES is also considering electron ion collider designs [6].

  8. Selected problems in experimental intermediate energy physics. Progress report

    SciTech Connect

    Mayes, B.W.; Hungerford, E.V.; Pinsky, L.S.

    1992-09-01

    Objectives of this research program are to investigate forefront problems in experimental intermediate-energy physics, educate students in this field of research, and develop the instrumentation necessary. Generally, this research is designed to search for physical processes that cannot be explained by conventional models of elementary interactions. The program has three major thrusts: strange particle physics, where a strange quark is embedded in the nuclear medium; muon electro-weak decay, which involves a search for a violation of the standard model of the electro-weak interaction; and measurement of the spin-dependent structure function of the neutron. Current research is reported in the following areas: hyperon physics at the AGS, electroproduction of hypernuclei, test of the standard model of electro-weak interactions, spin structure function of nucleons, and instrumentation.

  9. 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).

  10. Problem-based learning: undergraduate physics by research

    NASA Astrophysics Data System (ADS)

    Raine, Derek; Symons, Sarah

    2012-01-01

    Problem-based learning (PBL) is an established pedagogy in many areas of education for the professions. Although there is an awareness of PBL in many departments of physics in the UK and many claim to include PBL-like instruction to some degree, it has made rather less impact in the physical sciences. This paper describes the aims of PBL and how these are implemented based on our experiences in Physics at the University of Leicester. It is not our purpose to discuss here the parochial details of this programme which are partly historical and adapted to local conditions. (The interested reader can find them on our web site.) Rather we look at general aspects of PBL in Physics in the light of our experience and that of others. In addition to numerous examples of PBL problems, our discussion includes the educational and philosophical underpinnings of PBL, the nature of the 'problem' in PBL, issues in facilitation and assessment as well as a brief review of the published evaluations of PBL. Space constraints mean we do not discuss the process of change management.

  11. 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.

  12. 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.

  13. 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

  14. 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

  15. Transfer of argumentation skills in conceptual physics problem solving

    NASA Astrophysics Data System (ADS)

    Rebello, Carina M.; Rebello, N. Sanjay

    2013-01-01

    We investigate the integration of argumentation in a physics course for future elementary teachers. Students were divided into two groups - construct and evaluate - to solve conceptual physics problems using corresponding forms of written argumentation. After training in small teams, each group received tasks that required transfer of skills to new problems requiring a different form of argumentation i.e. students trained to construct arguments were now required to evaluate arguments and vice versa. The process was repeated after three weeks during which more training was provided. Results indicate no significant improvement of argumentation on team training tasks over this period, but a statistically significant improvement on individual transfer tasks. Thus, three weeks of training did not improve students' performance on the team tasks, but it prepared them to transfer these skills to individual argumentation tasks.

  16. 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.

  17. Articulated Multimedia Physics, Lesson 6, Uniformly Accelerated Motion of Bodies Starting From Rest.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    As the sixth lesson of the Articulated Multimedia Physics Course, instructional materials are presented in this study guide with relation to the uniformly accelerated motion of bodies starting from rest. The objective is to teach students how a complete set of equations of motion is derived and how to use them. Free falling bodies near the Earth's…

  18. 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.

  19. 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…

  20. 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.

  1. Toward a physics design for NDCX-II, an ion accelerator for warm dense matter and HIF target physics studies

    NASA Astrophysics Data System (ADS)

    Friedman, A.; Barnard, J. J.; Briggs, R. J.; Davidson, R. C.; Dorf, M.; Grote, D. P.; Henestroza, E.; Lee, E. P.; Leitner, M. A.; Logan, B. G.; Sefkow, A. B.; Sharp, W. M.; Waldron, W. L.; Welch, D. R.; Yu, S. S.

    2009-07-01

    The Heavy Ion Fusion Science Virtual National Laboratory (HIFS-VNL), a collaboration of LBNL, LLNL, and PPPL, has achieved 60-fold pulse compression of ion beams on the Neutralized Drift Compression eXperiment (NDCX) at LBNL. In NDCX, a ramped voltage pulse from an induction cell imparts a velocity "tilt" to the beam; the beam's tail then catches up with its head in a plasma environment that provides neutralization. The HIFS-VNL's mission is to carry out studies of warm dense matter (WDM) physics using ion beams as the energy source; an emerging thrust is basic target physics for heavy ion-driven inertial fusion energy (IFE). These goals require an improved platform, labeled NDCX-II. Development of NDCX-II at modest cost was recently enabled by the availability of induction cells and associated hardware from the decommissioned advanced test accelerator (ATA) facility at LLNL. Our initial physics design concept accelerates a ˜30 nC pulse of Li+ ions to ˜3 MeV, then compresses it to ˜1 ns while focusing it onto a mm-scale spot. It uses the ATA cells themselves (with waveforms shaped by passive circuits) to impart the final velocity tilt; smart pulsers provide small corrections. The ATA accelerated electrons; acceleration of non-relativistic ions involves more complex beam dynamics both transversely and longitudinally. We are using an interactive one-dimensional kinetic simulation model and multidimensional Warp-code simulations to develop the NDCX-II accelerator section. Both LSP and Warp codes are being applied to the beam dynamics in the neutralized drift and final focus regions, and the plasma injection process. The status of this effort is described.

  2. 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.

  3. A review of vector convergence acceleration methods, with applications to linear algebra problems

    NASA Astrophysics Data System (ADS)

    Brezinski, C.; Redivo-Zaglia, M.

    In this article, in a few pages, we will try to give an idea of convergence acceleration methods and extrapolation procedures for vector sequences, and to present some applications to linear algebra problems and to the treatment of the Gibbs phenomenon for Fourier series in order to show their effectiveness. The interested reader is referred to the literature for more details. In the bibliography, due to space limitation, we will only give the more recent items, and, for older ones, we refer to Brezinski and Redivo-Zaglia, Extrapolation methods. (Extrapolation Methods. Theory and Practice, North-Holland, 1991). This book also contains, on a magnetic support, a library (in Fortran 77 language) for convergence acceleration algorithms and extrapolation methods.

  4. {open_quotes}Accelerators and Beams,{close_quotes} multimedia computer-based training in accelerator physics

    SciTech Connect

    Silbar, R.R.; Browman, A.A.; Mead, W.C.; Williams, R.A.

    1999-06-01

    We are developing a set of computer-based tutorials on accelerators and charged-particle beams under an SBIR grant from the DOE. These self-paced, interactive tutorials, available for Macintosh and Windows platforms, use multimedia techniques to enhance the user{close_quote}s rate of learning and length of retention of the material. They integrate interactive {open_quotes}On-Screen Laboratories,{close_quotes} hypertext, line drawings, photographs, two- and three-dimensional animations, video, and sound. They target a broad audience, from undergraduates or technicians to professionals. Presently, three modules have been published ({ital Vectors, Forces}, and {ital Motion}), a fourth ({ital Dipole Magnets}) has been submitted for review, and three more exist in prototype form ({ital Quadrupoles, Matrix Transport}, and {ital Properties of Charged-Particle Beams}). Participants in the poster session will have the opportunity to try out these modules on a laptop computer. {copyright} {ital 1999 American Institute of Physics.}

  5. Accelerator-based techniques for the support of senior-level undergraduate physics laboratories

    NASA Astrophysics Data System (ADS)

    Williams, J. R.; Clark, J. C.; Isaacs-Smith, T.

    2001-07-01

    Approximately three years ago, Auburn University replaced its aging Dynamitron accelerator with a new 2MV tandem machine (Pelletron) manufactured by the National Electrostatics Corporation (NEC). This new machine is maintained and operated for the University by Physics Department personnel, and the accelerator supports a wide variety of materials modification/analysis studies. Computer software is available that allows the NEC Pelletron to be operated from a remote location, and an Internet link has been established between the Accelerator Laboratory and the Upper-Level Undergraduate Teaching Laboratory in the Physics Department. Additional software supplied by Canberra Industries has also been used to create a second Internet link that allows live-time data acquisition in the Teaching Laboratory. Our senior-level undergraduates and first-year graduate students perform a number of experiments related to radiation detection and measurement as well as several standard accelerator-based experiments that have been added recently. These laboratory exercises will be described, and the procedures used to establish the Internet links between our Teaching Laboratory and the Accelerator Laboratory will be discussed.

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

    DOE PAGES

    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.

  7. 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.

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

    PubMed

    Arif, Muhammad; Kattan, Ahmed

    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.

  9. 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

  10. 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.

  11. 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.

  12. 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…

  13. 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…

  14. Future accelerators (?)

    SciTech Connect

    John Womersley

    2003-08-21

    I describe the future accelerator facilities that are currently foreseen for electroweak scale physics, neutrino physics, and nuclear structure. I will explore the physics justification for these machines, and suggest how the case for future accelerators can be made.

  15. Occupational health problems and injuries among Quebec's physical educators.

    PubMed

    Lemoyne, Jean; Laurencelle, Louis; Lirette, Michel; Trudeau, François

    2007-09-01

    The purpose of this study was to describe the traumatology of teaching physical education (PE) and to document the causes and mechanisms of injuries in this occupation. Our sample was composed of 314 physical educators (PEs) teaching at three school levels (primary school, secondary school and college) who responded to a questionnaire survey. The results showed a 0.55 rate of recent lesion per teacher per year (0.65 for women and 0.51 for men). A total of 37.6% of subjects were affected by a lesion during the last year at work. Subjects with a higher weekly frequency of leisure physical activities or endurance activities (five times and more) were less affected by chronic lesions as well as those who frequently practiced aerobic physical activities. Prevalence of chronic injuries was higher in older teachers. Our results confirm that the rate of lesions in this group of workers is high, and that school level and respondent age may influence the rate of lesion and the characteristics of risk factors. In particular, the effect of ageing and teaching specialization on the incidence of occupational problems in PEs warrants further research. Given the relatively high rate of injuries among PE teachers, we suggest that it is necessary to further explore preventive strategies to reduce occupational risk in these workers. In particular, prophylactic physical activity outside of work may represent such a strategy since PEs more active outside their work have lower chronic injury prevalence. PEs gave long periods of standing the highest rating for movements or positions most likely to cause them occupational injuries. It can thus be suggested to find ways to reduce standing position sustained for long periods.

  16. Model problems in plasma physics and gas dynamics

    SciTech Connect

    Soto, L.A.

    1984-01-01

    The solution for the distribution function of heavy ions in a background of electrons is studied. It is found that quite broad physical conditions on the distribution function are sufficient to eliminate any ambiguity in the steady state solutions and to determine a discrete spectrum of the Fokker Planck operator for the time dependent case. The more physical case of a Maxwell Boltzman electron distribution function is treated, and under the small mass ratio expansion it is shown to lead to one of the model solutions in zero order. First order mass ratio corrections are calculated. They do not change the discrete nature of the spectrum. A plasma heating application is suggested. A hydrodynamic model is formulated to account for the collision of two compressible flows. This model is applied to the problem of the interaction of the solar wind and the interstellar medium, and for a compressible flow past a sphere as a limit case. Both flows are considered to be steady, polytropic, and potential. The compressible problem is solved by means of two different perturbation schemes (The Janzen-Rayleigh method and the coordinate expansion). For the free-stream Mach number expansion the solution up to the third order is found.

  17. 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.

  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. Selected problems in experimental intermediate energy physics. [Dept. of Physics, Univ. of Houston

    SciTech Connect

    Mayes, B.W.; Hungerford, E.V.; Pinsky, L.S.

    1992-09-01

    Objectives of this research program are to investigate forefront problems in experimental intermediate-energy physics, educate students in this field of research, and develop the instrumentation necessary. Generally, this research is designed to search for physical processes that cannot be explained by conventional models of elementary interactions. The program has three major thrusts: strange particle physics, where a strange quark is embedded in the nuclear medium; muon electro-weak decay, which involves a search for a violation of the standard model of the electro-weak interaction; and measurement of the spin-dependent structure function of the neutron. Current research is reported in the following areas: hyperon physics at the AGS, electroproduction of hypernuclei, test of the standard model of electro-weak interactions, spin structure function of nucleons, and instrumentation.

  20. 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.

  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. 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

  3. 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)

  4. 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

  5. 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.

  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. A New Integral Transform for Solving Physical Problems

    NASA Astrophysics Data System (ADS)

    Vastola, John; Efthimiou, Costas

    2015-04-01

    Finding a good integral representation of the reciprocal gamma function is a problem that arises naturally from a certain method of evaluating infinite sums. After finding one representation, and observing that its form is suggestive of an integral transform, we naively define one, and go on to explore its properties. While our transform as we initially define it turns out to be problematic, we demonstrate how to redefine it so that important properties (reminiscent of the Laplace and Fourier transforms) are preserved. Of particular interest is that we may transform any entire function, and that the values of the transform at the nonnegative integers correspond to the function's Taylor coefficients. We may also transform large classes of continuous and meromorphic functions. Interestingly, the aforementioned relationship between a function's transform and a function's Taylor series can be exploited to calculate analytic ``approximations'' to transformable functions. Other topics, like defining the transform for real and complex arguments, and the geometry of transformed functions, are considered. Applications to ordinary and partial differential equations, and related physical problems (from classical mechanics, electrodynamics, and quantum mechanics, among others) are discussed.

  9. 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.

  10. 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…

  11. Unobtrusive heart rate estimation during physical exercise using photoplethysmographic and acceleration data.

    PubMed

    Mullan, Patrick; Kanzler, Christoph M; Lorch, Benedikt; Schroeder, Lea; Winkler, Ludwig; Laich, Larissa; Riedel, Frederik; Richer, Robert; Luckner, Christoph; Leutheuser, Heike; Eskofier, Bjoern M; Pasluosta, Cristian

    2015-08-01

    Photoplethysmography (PPG) is a non-invasive, inexpensive and unobtrusive method to achieve heart rate monitoring during physical exercises. Motion artifacts during exercise challenge the heart rate estimation from wrist-type PPG signals. This paper presents a methodology to overcome these limitation by incorporating acceleration information. The proposed algorithm consisted of four stages: (1) A wavelet based denoising, (2) an acceleration based denoising, (3) a frequency based approach to estimate the heart rate followed by (4) a postprocessing step. Experiments with different movement types such as running and rehabilitation exercises were used for algorithm design and development. Evaluation of our heart rate estimation showed that a mean absolute error 1.96 bpm (beats per minute) with standard deviation of 2.86 bpm and a correlation of 0.98 was achieved with our method. These findings suggest that the proposed methodology is robust to motion artifacts and is therefore applicable for heart rate monitoring during sports and rehabilitation. PMID:26737687

  12. 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

  13. Physical and emotional health problems experienced by youth engaged in physical fighting and weapon carrying.

    PubMed

    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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods

    PubMed Central

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-01-01

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell’s equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions than have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called Minimum Norm Estimates (MNE), promote source estimates with a small ℓ2 norm. Here, we consider a more general class of priors based on mixed-norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as Mixed-Norm Estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ1/ℓ2 mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ1/ℓ2 norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furhermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data. PMID:22421459

  20. Mixed-norm estimates for the M/EEG inverse problem using accelerated gradient methods

    NASA Astrophysics Data System (ADS)

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-04-01

    Magneto- and electroencephalography (M/EEG) measure the electromagnetic fields produced by the neural electrical currents. Given a conductor model for the head, and the distribution of source currents in the brain, Maxwell's equations allow one to compute the ensuing M/EEG signals. Given the actual M/EEG measurements and the solution of this forward problem, one can localize, in space and in time, the brain regions that have produced the recorded data. However, due to the physics of the problem, the limited number of sensors compared to the number of possible source locations, and measurement noise, this inverse problem is ill-posed. Consequently, additional constraints are needed. Classical inverse solvers, often called minimum norm estimates (MNE), promote source estimates with a small ℓ2 norm. Here, we consider a more general class of priors based on mixed norms. Such norms have the ability to structure the prior in order to incorporate some additional assumptions about the sources. We refer to such solvers as mixed-norm estimates (MxNE). In the context of M/EEG, MxNE can promote spatially focal sources with smooth temporal estimates with a two-level ℓ1/ℓ2 mixed-norm, while a three-level mixed-norm can be used to promote spatially non-overlapping sources between different experimental conditions. In order to efficiently solve the optimization problems of MxNE, we introduce fast first-order iterative schemes that for the ℓ1/ℓ2 norm give solutions in a few seconds making such a prior as convenient as the simple MNE. Furthermore, thanks to the convexity of the optimization problem, we can provide optimality conditions that guarantee global convergence. The utility of the methods is demonstrated both with simulations and experimental MEG data.

  1. Moment-Based Accelerators for Kinetic Problems with Application to Inertial Confinement Fusion

    NASA Astrophysics Data System (ADS)

    Taitano, William Tsubasa-Tsutsui

    In inertial confinement fusion (ICF), the kinetic ion and charge separation field effects may play a significant role in the difference between the measured neutron yield in experiments and the predicted yield from fluid codes. Two distinct of approaches exists in modeling plasma physics phenomena: fluid and kinetic approaches. While the fluid approach is computationally less expensive, robust closures are difficult to obtain for a wide separation in temperature and density. While the kinetic approach is a closed system, it resolves the full 6D phase space and classic explicit numerical schemes restrict both the spatial and time-step size to a point where the method becomes intractable. Classic implicit system require the storage and inversion of a very large linear system which also becomes intractable. This dissertation will develop a new implicit method based on an emerging moment-based accelerator which allows one to step over stiff kinetic time-scales. The new method converges the solution per time-step stably and efficiently compared to a standard Picard iteration. This new algorithm will be used to investigate mixing in Omega ICF fuel-pusher interface at early time of the implosion process, fully kinetically.

  2. 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.

  3. 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

  4. 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

  5. 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

  6. 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…

  7. 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

  8. 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.

  9. 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.

  10. 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

  11. 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

  12. 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

  13. 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

  14. 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.

  15. 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…

  16. 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)

  17. Current Status of the Problem of Cosmological Variability of Fundamental Physical Constants

    NASA Astrophysics Data System (ADS)

    Varshslovich, D.A.; Ivanchik, A.V.; Orlov, A.V.; Potekhin, A.Y.; Petitjean, P.

    We review the current status of the problem of cosmological variability of fundamental physical constants, provided by modern laboratory experiments, Oklo phenomena analysis, and especially astronomical observations.

  18. Anterior cruciate ligament augmentation for rotational instability following primary reconstruction with an accelerated physical therapy protocol.

    PubMed

    Carey, Timothy; Oliver, David; Pniewski, Josh; Mueller, Terry; Bojescul, John

    2013-01-01

    The purpose of the present study is to present the results of anterior cruciate ligament (ACL) augmentation for patients having rotational instability despite an intact vertical graft in lieu of conventional revision ACL reconstruction. ACL augmentation surgery with a horizontal graft was performed to augment a healed vertical graft on five patients and an accelerated rehabilitation protocol was instituted. Functional outcomes were assessed by the Lower Extremity Functional Scale (LEFS) and the Modified Cincinnati Rating System (MCRS). All patients completed physical therapy within 5 months and were able to return to full military duty without limitation. LEFS and MCRS were significantly improved. ACL augmentation with a horizontal graft provides an excellent alternative to ACL revision reconstruction for patients with an intact vertical graft, allowing an earlier return to duty for military service members.

  19. 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.

  20. 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)

  1. Beam Polarization at the ILC: the Physics Impact and the Accelerator Solutions

    SciTech Connect

    Aurand, B.; Bailey, I.; Bartels, C.; Brachmann, A.; Clarke, J.; Hartin, A.; Hauptman, J.; Helebrant, C.; Hesselbach, S.; Kafer, D.; List, J.; Lorenzon, W.; Marchesini, I.; Monig, Klaus; Moffeit, K.C.; Moortgat-Pick, G.; Riemann, S.; Schalicke, A.; Schuler, P.; Starovoitov, P.; Ushakov, A.; /DESY /DESY, Zeuthen /Bonn U. /SLAC

    2011-11-23

    In this contribution accelerator solutions for polarized beams and their impact on physics measurements are discussed. Focus are physics requirements for precision polarimetry near the interaction point and their realization with polarized sources. Based on the ILC baseline programme as described in the Reference Design Report (RDR), recent developments are discussed and evaluated taking into account physics runs at beam energies between 100 GeV and 250 GeV, as well as calibration runs on the Z-pole and options as the 1TeV upgrade and GigaZ. The studies, talks and discussions presented at this conference demonstrated that beam polarization and its measurement are crucial for the physics success of any future linear collider. To achieve the required precision it is absolutely decisive to employ multiple devices for testing and controlling the systematic uncertainties of each polarimeter. The polarimetry methods for the ILC are complementary: with the upstream polarimeter the measurements are performed in a clean environment, they are fast and allow to monitor time-dependent variations of polarization. The polarimeter downstream the IP will measure the disrupted beam resulting in high background and much lower statistics, but it allows access to the depolarization at the IP. Cross checks between the polarimeter results give redundancy and inter-calibration which is essential for high precision measurements. Current plans and issues for polarimeters and also energy spectrometers in the Beam Delivery System of the ILC are summarized in reference [28]. The ILC baseline design allows already from the beginning the operation with polarized electrons and polarized positrons provided the spin rotation and the fast helicity reversal for positrons will be implemented. A reversal of the positron helicity significantly slower than that of electrons is not recommended to not compromise the precision and hence the success of the ILC. Recently to use calibration data at the Z

  2. 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.

  3. Problems in classical potential theory with applications to mathematical physics

    NASA Astrophysics Data System (ADS)

    Lundberg, Erik

    In this thesis we are interested in some problems regarding harmonic functions. The topics are divided into three chapters. Chapter 2 concerns singularities developed by solutions of the Cauchy problem for a holomorphic elliptic equation, especially Laplace's equation. The principal motivation is to locate the singularities of the Schwarz potential. The results have direct applications to Laplacian growth (or the Hele-Shaw problem). Chapter 3 concerns the Dirichlet problem when the boundary is an algebraic set and the data is a polynomial or a real-analytic function. We pursue some questions related to the Khavinson-Shapiro conjecture. A main topic of interest is analytic continuability of the solution outside its natural domain. Chapter 4 concerns certain complex-valued harmonic functions and their zeros. The special cases we consider apply directly in astrophysics to the study of multiple-image gravitational lenses.

  4. 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

  5. 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)

  6. Notation of physical equations no longer a problem.

    PubMed

    Gehbauer, F; Rau, K L

    1979-08-01

    Physical quantities and equations are used to define the laws of natural and engineering sciences. Clarity has been brought in equal measure into the the theory of physical quantities and the SI-system of units due to the basic work of Wallot and that of national and international institutions. For practical use in this paper, the most important rules and definitions for the formulation of physical equations are treated in an elementary form and the ease of their use is demonstrated in the following examples: speed of a car, capacitance of a plate capacitor, thermal emission of the cathode of an x-ray tube, oxygen uptake in cardiology, mole concentration and mass concentration of a substance in a solution. In addition, some important quantities and units of cardiology were summarized in a table.

  7. Physical problems in the theory of stellar evolution

    NASA Astrophysics Data System (ADS)

    Bisnovatyi-Kogan, Gennadii S.

    A systematic exposition of physical processes occurring in stars is given. Methods and results of evolution calculations for single stars are presented, starting with their formation and continuing to the final stages of the formation of white dwarfs, neutron stars, and black holes. Various types of instabilites arising during the course of evolution are also discussed. Recent results in the fields of statistical physics and physical kinetics, suitable for determining equations of state and transport properties in stars are examined; results from the theories of nuclear reactions and weak interactions are also considered. It is noted that the present work can be used as a handbook for the application of modern methods to the study of the internal structure and evolution of stars.

  8. 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…

  9. Physics models in the MARS15 code for accelerator and space applications.

    SciTech Connect

    Mokhov, N. V.; Gudima, K. K.; Mashnik, S. G.; Rakhno, I. L.; Sierk, A. J.; Striganov, S.

    2004-01-01

    The MARS code system, developed over 30 years, is a set of Monte Carlo programs for detailed simulation of hadronic and electromagnetic cascades in an arbitrary geometry of accelerator, detector and spacecraft components with particle energy ranging from a fraction of an electron volt up to 100 TeV. The new MARS15 (2004) version is described with an emphasis on modeling physics processes. This includes an extended list of elementary particles and arbitrary heavy ions, their interaction cross-sections, inclusive and exclusive nuclear event generators, photo - hadron production, correlated ionization energy loss and multiple Coulomb scattering, nuclide production and residual activation, and radiation damage (DPA). In particular, the details of a new model for leading baryon production and implementation of advanced versions of the Cascade-Exciton Model (CEM03), and the Los Alamos version of Quark-Gluon String Model (LAQGSM03) are given. The applications that are motivating these developments, needs for better nuclear data, and future physics improvements are described.

  10. Accelerator Technology and High Energy Physics Experiments, Photonics Applications and Web Engineering, Wilga, May 2012

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2012-05-01

    The paper is the second part (out of five) of the research survey of WILGA Symposium work, May 2012 Edition, concerned with accelerator technology and high energy physics experiments. It presents a digest of chosen technical work results shown by young researchers from different technical universities from this country during the XXXth Jubilee SPIE-IEEE Wilga 2012, May Edition, symposium on Photonics and Web Engineering. Topical tracks of the symposium embraced, among others, nanomaterials and nanotechnologies for photonics, sensory and nonlinear optical fibers, object oriented design of hardware, photonic metrology, optoelectronics and photonics applications, photonicselectronics co-design, optoelectronic and electronic systems for astronomy and high energy physics experiments, JET and pi-of-the sky experiments development. The symposium is an annual summary in the development of numerable Ph.D. theses carried out in this country in the area of advanced electronic and photonic systems. It is also a great occasion for SPIE, IEEE, OSA and PSP students to meet together in a large group spanning the whole country with guests from this part of Europe. A digest of Wilga references is presented [1-275].

  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. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. In Physics Class, Exercises Can Also Cause Problems.

    ERIC Educational Resources Information Center

    Johsua, Samuel; Dupin, Jean-Jacques

    1991-01-01

    French tenth grade physics classes were observed as they studied electric circuits over a one-year period. An analysis is presented of tests taken during the year. The main point separating "average" students from "good" ones is their performances in "implicitly difficult exercises," that is, in what appears beforehand to be a minor deviation from…

  18. 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…

  19. Adolescent exposure to violence and adult physical and mental health problems.

    PubMed

    Franzese, Robert J; Covey, Herbert C; Tucker, Abigail S; McCoy, Leah; Menard, Scott

    2014-12-01

    Evidence on the relationship of adolescent exposure to violence (AEV) with adult physical and mental health problems is limited, with studies often focusing on earlier childhood rather than adolescence, and also on short term rather than long term outcomes. Information specifically on the relationship of AEV to seeking help for mental health problems in adulthood from either formal sources such as mental health professionals or informal sources such as friends and clergy is even more difficult to find. The present study investigates how adolescent exposure to violence (AEV), in the form of parental physical abuse, witnessing parental violence, and exposure to violence in the neighborhood, are related to self-reported adult physical problems and seeking formal or informal assistance with mental health, controlling for more general adolescent violent victimization and for self-reports and parent reports of mental health problems in adolescence. This study adds to the literature on AEV and adult physical problems, and provides a rare look at the relationship of AEV to adult help-seeking for mental health problems. The results suggest that AEV is associated with mental health problems in adolescence for both females and males, that for females AEV is related to physical problems and to seeking help for mental health problems in adulthood, but for males the only significant relationship involves inconsistent reports of witnessing parental violence and adult physical problems.

  20. 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…

  1. 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.

  2. 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…

  3. 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)

  4. 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.

  5. 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

  6. Some problems on rf breakdown in room temperature accelerator structure, a possible criterion

    SciTech Connect

    Wang, J.W.

    1986-04-01

    The discussion is confined to high gradient, room-temperature accelerators which have clean well-finished cavity surfaces and good vacuum conditions. Breakdown-initiating mechanisms due to ''cold'' field electron emission occurring at isolated sites on broad-area cavity surfaces, where the field is enhanced, are described. The influences of an alternating field and transition time tunneling are taken into account. The thermal instability resulting in vacuum voltage breakdown is hypothesized to derive a new criterion for room-temperature accelerator structure. 18 refs., 5 figs. (DWL)

  7. 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.

  8. 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.

  9. 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…

  10. 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…

  11. Comorbidity of physical and motor problems in children with autism.

    PubMed

    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 spectrum. Among these conditions are premature birth, birth defects, gross and fine motor skills, and obesity. Each of these topics is addressed, and what researchers have found are presented. These data have important implications for the types of collateral behaviors that should be assessed and treated, along with the core symptoms of autism.

  12. 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.…

  13. Medical Physics: Forming and testing solutions to clinical problems.

    PubMed

    Tsapaki, Virginia; Bayford, Richard

    2015-11-01

    According to the European Federation of Organizations for Medical Physics (EFOMP) policy statement No. 13, "The rapid advance in the use of highly sophisticated equipment and procedures in the medical field increasingly depends on information and communication technology. In spite of the fact that the safety and quality of such technology is vigorously tested before it is placed on the market, it often turns out that the safety and quality is not sufficient when used under hospital working conditions. To improve safety and quality for patient and users, additional safeguards and related monitoring, as well as measures to enhance quality, are required. Furthermore a large number of accidents and incidents happen every year in hospitals and as a consequence a number of patients die or are injured. Medical Physicists are well positioned to contribute towards preventing these kinds of events". The newest developments related to this increasingly important medical speciality were presented during the 8th European Conference of Medical Physics 2014 which was held in Athens, 11-13 September 2014 and hosted by the Hellenic Association of Medical Physicists (HAMP) in collaboration with the EFOMP and are summarized in this issue.

  14. Boltzmann-Arrhenius (baz) Model in Physics-Of Problems

    NASA Astrophysics Data System (ADS)

    Suhir, E.; Kang, S.-M.

    2013-05-01

    Boltzmann-Arrhenius-Zhurkov (BAZ) model enables one to obtain a simple, easy-to-use and physically meaningful formula for the evaluation of the probability of failure (PoF) of a material after the given time in operation at the given temperature and under the given stress (not necessarily mechanical). It is shown that the material degradation (aging, damage accumulation, flaw propagation, etc.) can be viewed, when BAZ model is considered, as a Markovian process, and that the BAZ model can be obtained as the steady-state solution to the Fokker-Planck equation in the theory of Markovian processes. It is shown also that the BAZ model addresses the worst and a reasonably conservative situation, when the highest PoF is expected. It is suggested therefore that the transient period preceding the condition addressed by the steady-state BAZ model need not be accounted for in engineering evaluations. However, when there is an interest in understanding the physics of the transient degradation process, the obtained solution to the Fokker-Planck equation can be used for this purpose.

  15. The interplay of externalizing problems and physical and inductive discipline during childhood.

    PubMed

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

    2013-11-01

    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, multimethod 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.

  16. 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

  17. Earth's Rotation: A Challenging Problem in Mathematics and Physics

    NASA Astrophysics Data System (ADS)

    Ferrándiz, José M.; Navarro, Juan F.; Escapa, Alberto; Getino, Juan

    2015-01-01

    A suitable knowledge of the orientation and motion of the Earth in space is a common need in various fields. That knowledge has been ever necessary to carry out astronomical observations, but with the advent of the space age, it became essential for making observations of satellites and predicting and determining their orbits, and for observing the Earth from space as well. Given the relevant role it plays in Space Geodesy, Earth rotation is considered as one of the three pillars of Geodesy, the other two being geometry and gravity. Besides, research on Earth rotation has fostered advances in many fields, such as Mathematics, Astronomy and Geophysics, for centuries. One remarkable feature of the problem is in the extreme requirements of accuracy that must be fulfilled in the near future, about a millimetre on the tangent plane to the planet surface, roughly speaking. That challenges all of the theories that have been devised and used to-date; the paper makes a short review of some of the most relevant methods, which can be envisaged as milestones in Earth rotation research, emphasizing the Hamiltonian approach developed by the authors. Some contemporary problems are presented, as well as the main lines of future research prospected by the International Astronomical Union/International Association of Geodesy Joint Working Group on Theory of Earth Rotation, created in 2013.

  18. 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

    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 wave 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.

  19. 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.

  20. 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). )

  1. 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.

  2. 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)

  3. 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

  4. 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.

  5. Physical basis for the ofloxacin-induced acceleration of lysozyme aggregation and polymorphism in amyloid fibrils.

    PubMed

    Muthu, Shivani A; Mothi, Nivin; Shiriskar, Sonali M; Pissurlenkar, Raghuvir R S; Kumar, Anil; Ahmad, Basir

    2016-02-15

    Aggregation of globular proteins is an intractable problem which generally originates from partially folded structures. The partially folded structures first collapse non-specifically and then reorganize into amyloid-like fibrils via one or more oligomeric intermediates. The fibrils and their on/off pathway intermediates may be toxic to cells and form toxic deposits in different human organs. To understand the basis of origins of the aggregation diseases, it is vital to study in details the conformational properties of the amyloidogenic partially folded structures of the protein. In this work, we examined the effects of ofloxacin, a synthetic fluoroquinolone compound on the fibrillar aggregation of hen egg-white lysozyme. Using two aggregation conditions (4M GuHCl at pH 7.0 and 37 °C; and pH 1.7 at 65 °C) and a number of biophysical techniques, we illustrate that ofloxacin accelerates fibril formation of lysozyme by binding to partially folded structures and modulating their secondary, tertiary structures and surface hydrophobicity. We also demonstrate that Ofloxacin-induced fibrils show polymorphism of morphology, tinctorial properties and hydrophobic surface exposure. This study will assist in understanding the determinant of fibril formation and it also indicates that caution should be exercised in the use of ofloxacin in patients susceptible to various aggregation diseases.

  6. 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…

  7. 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.

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

    DOE PAGES

    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

  9. A solution to the accelerated-predator-satiety Lotka-Volterra predator-prey problem using Boubaker polynomial expansion scheme.

    PubMed

    Dubey, B; Zhao, T G; Jonsson, M; Rahmanov, H

    2010-05-01

    In this study, an analytical method is introduced for the identification of predator-prey populations time-dependent evolution in a Lotka-Volterra predator-prey model which takes into account the concept of accelerated-predator-satiety. Oppositely to most of the predator-prey problem models, the actual model does not suppose that the predation is strictly proportional to the prey density. In reference to some recent experimental results and particularly to the conclusions of May (1973) about predators which are 'never not hungry', an accelerated satiety function is matched with the initial conventional equations. Solutions are plotted and compared to some relevant ones. The obtained trends are in good agreement with many standard Lotka-Volterra solutions except for the asymptotic behaviour.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Statistical physics approaches to understanding the firm growth problem

    NASA Astrophysics Data System (ADS)

    Fu, Dongfeng

    This thesis applies statistical physics approaches to investigate quantitatively the size and growth of the complex system of business firms. We study the logarithm of the one-year growth rate of firms g ≡ log(S(t + 1)/S( t)) where S(t) and S( t + 1) are the sizes of firms in the year t and t + 1 measured in monetary values. Part I in this thesis reviews some main empirical results of firm size and firm growth based on different databases. They are (i) the size distribution of firms P(S) are found to be skewed (either log-normal or power-law depending on the different databases), (ii) the growth-rate distributions of firms P(g) are of Laplace form with power-law tails, (iii) the standard deviation of firm growth rates is related by a negative power-law to the firm size. The distribution of firm growth rates conditioned on firm size collapses onto a single curve, which implies that a universal functional form may exist to describe the distribution of firm growth rate. Part II models the Entry & Exit effect and firm proportional growth using a generalized preferential attachment model. The model assumes that a new firm enters the system with a constant rate; a new unit enters/exits one of existing firms preferentially, that it, the larger firms have bigger probability to obtain the new unit, and the larger firms have bigger probability to lose a unit. The model successfully explains the observations: (i) the distribution of unit number P( K) in a firm is power law with exponential tails, (ii) P (g) is of Laplace form with power-law tails with exponent 3. Part III studies the Merging & Splitting effect in the framework of Coase theory using a dynamic percolation model in a 2-dimensional lattice where each row represents a product and each column can represent a consumer; a cell is a potential transaction. The size of the firm would be represented by the number of the cells it covers in the lattice. The model explains the facts that P(S) is power-law, P(g) is tent

  15. 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.

  16. 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.

  17. 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

  18. 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'…

  19. 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…

  20. 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…

  1. 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…

  2. 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…

  3. 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.…

  4. 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…

  5. 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…

  6. 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…

  7. 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

  8. 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

  9. 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

  10. 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.

  11. Can Accelerators Accelerate Learning?

    SciTech Connect

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

    2009-03-10

    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.

  12. 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…

  13. 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…

  14. 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…

  15. 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…

  16. 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…

  17. 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…

  18. 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.

  19. 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…

  20. 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…

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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. PMID:27559474

  9. 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.

  10. 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

  11. J-PAS: The Javalambre Physics of the Accelerated Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Cepa, J.; Benítez, N.; Dupke, R.; Moles, M.; Sodré, L.; Cenarro, A. J.; Marín-Franch, A.; Taylor, K.; Cristóbal, D.; Fernández-Soto, A.; Mendes de Oliveira, C.; Abramo, L. R.; Alcaniz, J. S.; Overzier, R.; Hernández-Monteagudo, A.; Alfaro, E. J.; Kanaan, A.; Carvano, M.; Reis, R. R. R.; J-PAS Team

    2016-10-01

    The Javalambre Physics of the Accelerated Universe Astrophysical Survey (J-PAS) is a narrow band, very wide field Cosmological Survey to be carried out from the Javalambre Observatory in Spain with a purpose-built, dedicated 2.5 m telescope and a 4.7 sq.deg. camera with 1.2 Gpix. Starting in late 2016, J-PAS will observe 8500 sq.deg. of Northern Sky and measure Δz˜0.003(1+z) photo-z for 9× 107 LRG and ELG galaxies plus several million QSOs, sampling an effective volume of ˜ 14 Gpc3 up to z=1.3 and becoming the first radial BAO experiment to reach Stage IV. J-PAS will detect 7× 105 galaxy clusters and groups, setting constraints on Dark Energy which rival those obtained from its BAO measurements. Thanks to the superb characteristics of the site (seeing ˜ 0.7 arcsec), J-PAS is expected to obtain a deep, sub-arcsec image of the Northern sky, which combined with its unique photo-z precision will produce one of the most powerful cosmological lensing surveys before the arrival of Euclid. J-PAS's unprecedented spectral time domain information will enable a self-contained SN survey that, without the need for external spectroscopic follow-up, will detect, classify and measure σz˜ 0.5 redshifts for ˜ 4000 SNeIa and ˜ 900 core-collapse SNe. The key to the J-PAS potential is its innovative approach: a contiguous system of 54 filters with 145 Å width, placed 100 Å apart over a multi-degree FoV is a powerful redshift machine, with the survey speed of a 4000 multiplexing low resolution spectrograph, but many times cheaper and much faster to build. The J-PAS camera is equivalent to a 4.7 sq.deg. IFU and 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.

  12. 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

  13. 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.

  14. 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.

  15. Physical Property Changes in Plutonium from Accelerated Aging using Pu-238 Enrichment

    SciTech Connect

    Chung, B W; Choi, B W; Saw, C K; Thompson, S R; Woods, C H; Hopkins, D J; Ebbinghaus, B B

    2006-12-20

    We present changes in volume, immersion density, and tensile properties observed from accelerated aged plutonium alloys. Accelerated alloys (or spiked alloys) are plutonium alloys enriched with approximately 7.5 weight percent of the faster-decaying {sup 238}Pu to accelerate the aging process by approximately 17 times the rate of unaged weapons-grade plutonium. After sixty equivalent years of aging on spiked alloys, the dilatometry shows the samples at 35 C have swelled in volume by 0.15 to 0.17 % and now exhibit a near linear volume increase due to helium in-growth. The immersion density of spiked alloys shows a decrease in density, similar normalized volumetric changes (expansion) for spiked alloys. Tensile tests show increasing yield and engineering ultimate strength as spiked alloys are aged.

  16. 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.

  17. Exploring the cognitive components of solving non-trivial physics problems

    NASA Astrophysics Data System (ADS)

    Korsunsky, Boris Mikhaylovich

    This study explores the cognitive mechanisms of problem solving in physics and the students' problem-solving strategies. Based on the review of prior research and on the author's own experience, a theory of problem-solving skills is proposed. This theory suggests the existence of a meaningful dichotomy between the students' rigid knowledge and their bisociation skills. The goals of the study are to test the proposed theory and to gain further insight into the nature of students' difficulties and the strategies that help successful solvers to overcome those difficulties. To conduct the study, a large group of AP Physics C students was given several physics tasks to solve. The participants' interactions with the tasks were observed and recorded in several different ways. The data collected are analyzed in conjunction with the background information provided by the students. Correlation statistics and linear regression models are used to determine the factors relevant to individuals' success in problem solving. The written comments and the protocols of student interviews are analyzed qualitatively, using the narrative summary and the cluster methods. The results support the idea of rigid knowledge and bisociation being two distinct sets of skills essential to problem solving; the notion of bisociation as the main factor limiting one's problem-solving success is also supported. In addition, specific behaviors associated with both successful and unsuccessful problem-solving processes were identified and analyzed. Based on the findings of the study, new approaches to teacher training, curriculum development, educational research and classroom practice are proposed.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. Physical and psychological health problems of garment workers in the Fiji.

    PubMed

    Chand, Anand

    2006-09-01

    This paper unravels the physical and psychological health problems of garment workers in Fiji. It is based on research work done between 1997-2007. Majority of the garment workers are women. The main physical health problems faced by workers are: 'Occupational fatigue syndrome', body pains, obesity, and bladder and kidney problems. The major psychological problems work stress and depression. Work stress and depression are caused by 'intensification of work' to meet daily targets, strict factory rules and regulations, poor pay, poor working conditions, in-human abuse, and fear of job loss. Since garment workers do not have much education and skills they have no other option but to work for the garment industry and suffer in silence.

  3. 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.

  4. 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.

  5. 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

  6. Classification scheme for phenomenological universalities in growth problems in physics and other sciences.

    PubMed

    Castorina, P; Delsanto, P P; Guiot, C

    2006-05-12

    A classification in universality classes of broad categories of phenomenologies, belonging to physics and other disciplines, may be very useful for a cross fertilization among them and for the purpose of pattern recognition and interpretation of experimental data. We present here a simple scheme for the classification of nonlinear growth problems. The success of the scheme in predicting and characterizing the well known Gompertz, West, and logistic models, suggests to us the study of a hitherto unexplored class of nonlinear growth problems.

  7. Classification Scheme for Phenomenological Universalities in Growth Problems in Physics and Other Sciences

    NASA Astrophysics Data System (ADS)

    Castorina, P.; Delsanto, P. P.; Guiot, C.

    2006-05-01

    A classification in universality classes of broad categories of phenomenologies, belonging to physics and other disciplines, may be very useful for a cross fertilization among them and for the purpose of pattern recognition and interpretation of experimental data. We present here a simple scheme for the classification of nonlinear growth problems. The success of the scheme in predicting and characterizing the well known Gompertz, West, and logistic models, suggests to us the study of a hitherto unexplored class of nonlinear growth problems.

  8. 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.

  9. 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.

  10. Reduced quality and accelerated follicle loss with female reproductive aging - does decline in theca dehydroepiandrosterone (DHEA) underlie the problem?

    PubMed Central

    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

  11. 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

  12. A pseudo-spectral collocation method applied to the problem of convective diffusive transport in fluids subject to unsteady residual accelerations

    NASA Technical Reports Server (NTRS)

    Alexander, J. Iwan; Ouazzani, Jalil

    1989-01-01

    The problem of determining the sensitivity of Bridgman-Stockbarger directional solidification experiments to residual accelerations of the type associated with spacecraft in low earth orbit is analyzed numerically using a pseudo-spectral collocation method. The approach employs a novel iterative scheme combining the method of artificial compressibility and a generalized ADI method. The results emphasize the importance of the consideration of residual accelerations and careful selection of the operating conditions in order to take full advantages of the low gravity conditions.

  13. 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.

  14. 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

  15. 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

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

    DOE PAGES

    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

  17. 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…

  18. Effectiveness of Computer-Assisted STAD Cooperative Learning Strategy on Physics Problem Solving, Achievement and Retention

    ERIC Educational Resources Information Center

    Gambari, Amosa Isiaka; Yusuf, Mudasiru Olalere

    2015-01-01

    This study investigated the effectiveness of computer-assisted Students' Team Achievement Division (STAD) cooperative learning strategy on physics problem solving, students' achievement and retention. It also examined if the student performance would vary with gender. Purposive sampling technique was used to select two senior secondary schools…

  19. 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…

  20. 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.…

  1. 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.…

  2. 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…

  3. 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…

  4. 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…

  5. 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…

  6. The long shadow cast by childhood physical and mental problems on adult life

    PubMed Central

    Goodman, Alissa; Joyce, Robert; Smith, James P.

    2011-01-01

    In this article we assess and compare long-term adult socioeconomic status impacts from having experienced psychological and physical health problems in childhood. To do so, we use unique prospective data from the British National Child Development Study, a continuing panel study of a cohort of 17,634 children born in Great Britain during a single week in March 1958. To date there have been nine waves for this birth cohort to monitor their physical, educational, and social development, during childhood (at birth and 7, 11, and 16 y) and adulthood (age 23, 33, 42, 46, and 50 y). Excellent contemporaneous information exists throughout childhood on physical and psychological health, captured by doctor and nurse-led medical examinations and detailed parental and teacher questionnaires. This information is combined with a wealth of contemporaneous information on adult health and economic experiences collected from cohort members. Information includes their economic circumstances (earnings, labor supply, and other sources of family income), physical and psychological health, and relationship status. Large effects are found due to childhood psychological problems on the ability of affected children to work and earn as adults and on intergenerational and within-generation social mobility. Adult family incomes are reduced by 28% by age 50 y, with sustained impacts on labor supply, marriage stability, and the conscientiousness and agreeableness components of the “Big Five” personality traits. Effects of psychological health disorders during childhood are far more important over a lifetime than physical health problems. PMID:21444801

  7. 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"…

  8. 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.

  9. On the problems of relativistic laboratory astrophysics and fundamental physics with super powerful lasers

    NASA Astrophysics Data System (ADS)

    Bulanov, S. V.; Esirkepov, T. Zh.; Kando, M.; Koga, J.; Kondo, K.; Korn, G.

    2015-01-01

    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.

  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. 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.

  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. 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.

  15. 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.

  16. 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

  17. 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

  18. The Two-Body Problem: Balancing a Physics Career With a Family

    NASA Astrophysics Data System (ADS)

    McNeil, Laurie

    1997-03-01

    In this panel discussion organized by the APS Committee on the Status of Women in Physics, members of the panel will give brief presentations on the challenges they have faced in combining their physics careers with family life. Questions and comments from the audience will then be invited. Topics to be raised include having children while in graduate school, spousal relocation, institutional responses to the "two-body" problem, and industry vs. academia. The panel members will be Susan Coppersmith (U. Chicago), Jia Ling Lin (U. Wisconsin), Madelaine Msall (Bowdoin College), and Janet Tate (Oregon State U.). The discussion will be moderated by Laurie McNeil (U. North Carolina).

  19. Interpersonal violence is associated with depression and chronic physical health problems in midlife women.

    PubMed

    Humphreys, Janice; Lee, Kathryn A

    2009-04-01

    This research describes interpersonal violence (IPV) exposure in a community-based sample of midlife women from three ethnic groups and explores relationships among these exposures and variables associated with health outcomes. IPV, physical health, depression, and social support were measured by self-report questionnaires. More than 33% reported a history of physical abuse or sexual abuse and at least 20% reported both. Approximately 20% experienced sexual harassment in the past year. IPV exposure was associated with more chronic health problems and depressive symptoms. IPV, whenever it occurs, is detrimental to women's health regardless of socioeconomic status or ethnicity.

  20. 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.

  1. 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.

  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. 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…

  5. 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.

  6. 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

  7. 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.

  8. 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…

  9. 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.

  10. Physical Health Problems and Barriers to Optimal Health Care Among Children in Foster Care.

    PubMed

    Deutsch, Stephanie Anne; Fortin, Kristine

    2015-10-01

    Children and adolescents in foster care placement represent a unique population with special health care needs, often resulting from pre-placement early adversity and neglected, unaddressed health care needs. High rates of all health problems, including acute and/or chronic physical, mental, and developmental issues prevail. Disparities in health status and access to health care are observed. This article summarizes the physical health problems of children in foster care, who are predisposed to poor health outcomes when complex care needs are unaddressed. Despite recognition of the significant burden of health care need among this unique population, barriers to effective and optimal health care delivery remain. Legislative solutions to overcome obstacles to health care delivery for children in foster care are discussed.

  11. 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.

  12. 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.

  13. 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.

  14. Ongoing applications of soft computing technologies to real-world problems at Physical Optics Corporation

    NASA Astrophysics Data System (ADS)

    Kostrzewski, Andrew A.; Kim, Dai Hyun; Jannson, Tomasz P.; Savant, Gajendra D.; Kim, Jeongdal; Chen, Judy

    1998-10-01

    Soft computing is a set of promising computational tools for solving problems that are inherently well solved by humans but not by standard computing means. This paper presents an overview of R and D activities at Physical Optics Corporation in the area of soft computing. The company has been involved in soft computing for over ten years, and has pioneered several soft-computing methodologies, including fuzzied genetic algorithms and neuro-fuzzy networks. Several practical implementations of soft computing are discussed.

  15. 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

  16. 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.

  17. 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.

  18. The influence of horseback riding training on the physical function and psychological problems of stroke patients

    PubMed Central

    Lee, Dong-Kyu; Kim, Eun-Kyung

    2015-01-01

    [Purpose] The purpose of this study was to determine the influence of horseback riding training on the physical function and psychological problems of stroke patients. [Subjects and Methods] Thirty stroke patients were divided evenly into an experimental group and a control group. Both groups carried out neurodevelopmental treatment. The experimental group additionally performed mechanical horseback riding training for 30 minutes a day, 5 days a week, for 6 weeks. Physical function was evaluated using the Berg Balance Scale (BBS) and the Timed Up and Go Test (TUGT). Psychological problems were assessed using the Beck Depression Inventory (BDI). In order to compare differences within groups between before and after the experiment, the paired t test was conducted. In order to compare differences between groups before and after the experiment, the independent t test was conducted. [Results] In the experimental group, the BBS, TUGT, and BDI showed significant improvements after the intervention. The experimental group’s BBS, TUGT, and BDI post-intervention changes were significantly better than those observed in the control group. [Conclusion] According to our results, horseback riding training has a positive effect on the physical function and psychological problems of stroke patients. PMID:26504283

  19. How can we improve problem solving in undergraduate biology? Applying lessons from 30 years of physics education research.

    PubMed

    Hoskinson, A-M; Caballero, M D; Knight, J K

    2013-06-01

    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.

  20. 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

  1. 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.

  2. 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.

  3. 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

  4. 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

  5. Longitudinal Examination of Physical and Relational Aggression as Precursors to Later Problem Behaviors in Adolescents

    PubMed Central

    Herrenkohl, Todd I.; Catalano, Richard F.; Hemphill, Sheryl A.; Toumbourou, John W.

    2008-01-01

    Research has addressed the consequences of being a victim of physical and relational aggression, but less so the consequences of being an aggressor during adolescence. Consequently, relatively little is known about the extent to which aggression in early adolescence increases the risk of later aggression and other psychosocial problems. This study involves a representative sample of 7th- and 9th-grade students from Washington State (N = 1,942). Students were surveyed upon recruitment, and then again 1 and 2 years later, to learn about ongoing behavior problems, substance use, depression, and self-harm behaviors. Surveys also included measures of several hypothesized promotive factors: attachment to family, school commitment, and academic achievement. Findings suggest that being physically and/or relationally aggressive in Grades 7–9 increases the risk of aggression and possibly other problem behaviors after accounting for age, gender, race, and a prior measures of each outcome. Independent promotive effects were observed in most analyses, although family attachment appeared a less robust predictor overall. Implications for prevention include reducing aggression and enhancing promotive influences to lessen the risk of ongoing problems. PMID:19297882

  6. 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…

  7. 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

  8. 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

  9. 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

  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. On the Formal-Logical Analysis of the Foundations of Mathematics Applied to Problems in Physics

    NASA Astrophysics Data System (ADS)

    Kalanov, Temur Z.

    2016-03-01

    Analysis of the foundations of mathematics applied to problems in physics was proposed. The unity of formal logic and of rational dialectics is methodological basis of the analysis. It is shown that critical analysis of the concept of mathematical quantity - central concept of mathematics - leads to the following conclusion: (1) The concept of ``mathematical quantity'' is the result of the following mental operations: (a) abstraction of the ``quantitative determinacy of physical quantity'' from the ``physical quantity'' at that the ``quantitative determinacy of physical quantity'' is an independent object of thought; (b) abstraction of the ``amount (i.e., abstract number)'' from the ``quantitative determinacy of physical quantity'' at that the ``amount (i.e., abstract number)'' is an independent object of thought. In this case, unnamed, abstract numbers are the only sign of the ``mathematical quantity''. This sign is not an essential sign of the material objects. (2) The concept of mathematical quantity is meaningless, erroneous, and inadmissible concept in science because it represents the following formal-logical and dialectical-materialistic error: negation of the existence of the essential sign of the concept (i.e., negation of the existence of the essence of the concept) and negation of the existence of measure of material object.

  12. 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…

  13. 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

  14. The Development of Biomedical Applications of Nuclear Physics Detector Technology at the Thomas Jefferson National Accelerator Facility

    NASA Astrophysics Data System (ADS)

    Weisenberger, Andrew

    2003-10-01

    The Southeastern Universities Research Association (SURA) operates the Thomas Jefferson National Accelerator Facility (Jefferson Lab) for the United States Department of Energy. As a user facility for physicists worldwide, its primary mission is to conduct basic nuclear physics research of the atom's nucleus at the quark level. Within the Jefferson Lab Physics Division is the Jefferson Lab Detector Group which was formed to support the design and construction of new detector systems during the construction phase of the major detector systems at Jefferson Lab and to act as technical consultants for the lab scientists and users. The Jefferson Lab Detector Group, headed by Dr. Stan Majewski, has technical capabilities in the development and use of radiation detection systems. These capabilities include expertise in nuclear particle detection through the use of gas detectors, scintillation and light guide techniques, standard and position-sensitive photomultiplier tubes (PSPMTs), fast analog readout electronics and data acquisition, and on-line image formation and analysis. In addition to providing nuclear particle detector support to the lab, the group has for several years (starting in 1996) applied these technologies to the development of novel high resolution gamma-ray imaging systems for biomedical applications and x-ray imaging techniques. The Detector Group has developed detector systems for breast cancer detection, brain cancer therapy and small animal imaging to support biomedical research. An overview will be presented of how this small nuclear physics detector research group by teaming with universities, medical facilities, industry and other national laboratories applies technology originating from basic nuclear physics research to biomedical applications.

  15. 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

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

    NASA Astrophysics Data System (ADS)

    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, G. E.; Liu, W.

    2010-03-01

    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.

  18. 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.

  19. Skills needed for reading comprehension of physics texts and their relation to problem-solving ability

    NASA Astrophysics Data System (ADS)

    Koch, Adina; Eckstein, Shulamith G.

    This article reports an investigation of some of the skills needed for the critical reading of physics texts. To assess these skills a reading comprehension test was developed that combines features of errordetection and true-false-unreported tests. This test was administered to college students of physics, and the results were analyzed statistically to determine the separability of the skills and their hierarchical ranking. It was found that the skill required to comprehend texts in continuous format is of a higher level than and separable from the skill required to comprehend texts in the form of a separated list of statements. The skill required to discriminate unreported statements from the others (true and false) was found to be of a higher level than and separable from the skills required to make the other discriminations. The relation between the students' reading comprehension skills and their problem-solving ability was also investigated. Students' scores on reading comprehension of texts that require a very low problem-solving ability were found to be uncorrelated to their grades on solving problems that require a very low decoding ability. This implies that the two abilities are independent.Received: 31 August 1993; Revised: 27 July 1994;

  20. Internet addiction and physical and psychosocial behavior problems among rural secondary school students.

    PubMed

    Gür, Kamer; Yurt, Seher; Bulduk, Serap; Atagöz, Sinem

    2015-09-01

    The aim of this study was to determine secondary school students' levels of Internet addiction and the physical and psychosocial behavior problems they face while using the Internet. This descriptive study was conducted in three state secondary schools in a rural area in the western part of Turkey. This study's sample consisted of 549 students who agreed to participate, with the consent of their families, and who had an Internet connection at home. The data were evaluated using t-tests and variance analyses. In this study the students' score of Internet addiction was at medium level (mean addiction score 44.51 ± 17.90). There were significant differences between the students' Internet addiction scores and the presence of physical behavior problems (going to bed late, skipping meals, eating meals in front of the computer) and psychosocial behavior problems (suffering from conditions such as restlessness, anger, heart palpitations, or tremors when they could not connect to the Internet, decreased relationships with family and friends, feelings of anger, arguing with parents, and finding life boring and empty without an Internet connection).

  1. Accelerating efforts to prevent childhood obesity: spreading, scaling, and sustaining healthy eating and physical activity.

    PubMed

    Chang, Debbie I; Gertel-Rosenberg, Allison; Snyder, Kim

    2014-12-01

    During the past decade, progress has been made in addressing childhood obesity through policy and practice changes that encourage increased physical activity and access to healthy food. With the implementation of these strategies, an understanding of what works to prevent childhood obesity is beginning to emerge. The task now is to consider how best to spread, scale, and sustain promising childhood obesity prevention strategies. In this article we examine a project led by Nemours, a children's health system, to address childhood obesity. We describe Nemours's conceptual approach to spreading, scaling, and sustaining a childhood obesity prevention intervention. We review a component of a Nemours initiative in Delaware that focused on early care and education settings and its expansion to other states through the National Early Care and Education Learning Collaborative to prevent childhood obesity. We also discuss lessons learned. Focusing on the spreading, scaling, and sustaining of promising strategies has the potential to increase the reach and impact of efforts in obesity prevention and help ensure their impact on population health.

  2. J-PAS: The Javalambre-Physics of the Accelerated Universe Astrophysical Survey

    NASA Astrophysics Data System (ADS)

    Benítez, N.; Dupke, R.; Moles, M.; Sodré, L.; Cenarro, A. J.; Marín Franch, A.; Taylor, K.; Cristóbal, D.; Fernández-Soto, A.; Mendes de Oliveira, C.; Cepa-Nogué, J.; Abramo, L. R.; Alcaniz, J. S.; Overzier, R.; Hernández-Monteagudo, C.; Alfaro, E. J.; Kanaan, A.; Carvano, M.; Reis, R. R. R.; J-PAS Collaboration

    2015-05-01

    J-PAS is a Spanish-Brazilian 8500 deg^2 Cosmological Survey which will be carried out from the Javalambre Observatory with a purpose-built, dedicated 2.5 m telescope and a 4.7 deg^2 camera with 1.2 Gpix. Starting in 2015, J-PAS will use 59 filters to measure high precision 0.003(1+z) photometric redshifts for 90M galaxies plus several million QSOs, about 50 times more than the largest current spectroscopic survey, sampling an effective volume of ˜ 14 Gpc^3 up to z=1.3. J-PAS will not only be first radial BAO experiment to reach Stage IV; it will also detect and measure the mass of 7× 10^5 galaxy clusters and groups, setting constrains on Dark Energy which rival those obtained from BAO measurements. The combination of a set of 145 Å NB filters, placed 100 Å apart, and a multi-degree field of view is a powerful ``redshift machine'', equivalent to a 4000 multiplexing spectrograph, but many times cheaper to build. The J-PAS camera is equivalent to a very large, 4.7 deg^2 ``IFU'', which will produce a time-resolved, 3D image of the Northern Sky with a very wide range of scientific applications in Galaxy Evolution, Stellar Physics and the Solar System.

  3. Multi-processor developments in the United States for future high energy physics experiments and accelerators

    SciTech Connect

    Gaines, I.

    1988-03-01

    The use of multi-processors for analysis and high-level triggering in High Energy Physics experiments, pioneered by the early emulator systems, has reached maturity, in particular with the multiple microprocessor systems in use at Fermilab. It is widely acknowledged that such systems will fulfill the major portion of the computing needs of future large experiments. Recent developments at Fermilab's Advanced Computer Program will make such systems even more powerful, cost-effective, and easier to use than they are at present. The next generation of microprocessors, already available, will provide CPU power of about one VAX 780 equivalent/$300, while supporting most VMS FORTRAN extensions and large (>8MB) amounts of memory. Low cost high density mass storage devices (based on video tape cartridge technology) will allow parallel I/O to remove potential I/O bottlenecks in systems of over 1000 VAX equipment processors. New interconnection schemes and system software will allow more flexible topologies and extremely high data bandwidth, especially for on-line systems. This talk will summarize the work at the Advanced Computer Program and the rest of the US in this field. 3 refs., 4 figs.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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

  12. 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.

  13. 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.

  14. 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,…

  15. 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.

  16. 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

  17. Effects of early menarche on physical and psychosocial health problems in adolescent girls and adult women

    PubMed Central

    2016-01-01

    The menarcheal age of Korean women has been rapidly decreasing for the last 50 years, and the average menarcheal age of women born in the 1990s is approaching 12.6 years. In addition, interest in early puberty has been increasing recently owing to the rapid increase in precocious puberty. Generally, out of concern for short stature and early menarche, idiopathic central precocious puberty in female adolescents is treated with gonadotropin-releasing hormone analogs. Studies to date have described the association between early menarche and psychosocial problems such as delinquency and risky sexual behavior, as well as physical health problems such as obesity, diabetes, cardiovascular diseases, and breast cancer throughout the lifespan of women. However, the pathophysiological mechanism underlying this association has not been clarified thus far. In this article, we review and discuss the existing literature to describe the current understanding of the effects of early menarche on the physical and psychosocial health of adolescent girls and adult women. PMID:27721839

  18. 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

  19. Statistical physics analysis of the computational complexity of solving random satisfiability problems using backtrack algorithms

    NASA Astrophysics Data System (ADS)

    Cocco, S.; Monasson, R.

    2001-08-01

    The computational complexity of solving random 3-Satisfiability (3-SAT) problems is investigated using statistical physics concepts and techniques related to phase transitions, growth processes and (real-space) renormalization flows. 3-SAT is a representative example of hard computational tasks; it consists in knowing whether a set of αN randomly drawn logical constraints involving N Boolean variables can be satisfied altogether or not. Widely used solving procedures, as the Davis-Putnam-Loveland-Logemann (DPLL) algorithm, perform a systematic search for a solution, through a sequence of trials and errors represented by a search tree. The size of the search tree accounts for the computational complexity, i.e. the amount of computational efforts, required to achieve resolution. In the present study, we identify, using theory and numerical experiments, easy (size of the search tree scaling polynomially with N) and hard (exponential scaling) regimes as a function of the ratio α of constraints per variable. The typical complexity is explicitly calculated in the different regimes, in very good agreement with numerical simulations. Our theoretical approach is based on the analysis of the growth of the branches in the search tree under the operation of DPLL. On each branch, the initial 3-SAT problem is dynamically turned into a more generic 2+p-SAT problem, where p and 1 - p are the fractions of constraints involving three and two variables respectively. The growth of each branch is monitored by the dynamical evolution of α and p and is represented by a trajectory in the static phase diagram of the random 2+p-SAT problem. Depending on whether or not the trajectories cross the boundary between satisfiable and unsatisfiable phases, single branches or full trees are generated by DPLL, resulting in easy or hard resolutions. Our picture for the origin of complexity can be applied to other computational problems solved by branch and bound algorithms.

  20. 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.

  1. 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.

  2. Enhancing Physics Learning Through Data Analysis, Technical Writing and Repetitive Problem Solving

    NASA Astrophysics Data System (ADS)

    Singh Aurora, Tarlok

    2001-03-01

    At the University of the Sciences in Philadelphia, physics course is a required, two-semester sequence of courses for most of our majors' programs. There were concerns about the lack of grasping/comprehending the reading material and retention, and apathy toward the education. In addition, it was felt that some of the students had difficulty with the comprehension of the numerical data and its subsequent analysis. That is expected to make it hard to solve the word problems in lecture, and possibly reduce the retention of the important concepts useful in other courses. The author decided to ask the students to read and analyze a given set of technical data, and to try to generate a technical report under supervision, in contrast with the formal lab reports written at home. In addition, during lecture, the students were given to solve problems similar to the one previously solved in lecture. Upon completion, the students were asked to look at their lecture notes to identify their mistakes. After the felt that they had understood their errors, they were asked to re-solved the problem with everything closed. By omparing the two solutions, students were made aware of their short and long term retention ability. Hopefully, this excercise emphasized the importance of writing during studying, because most of their tests are in the written format. The experience gained in these excercises with be discussed. ACKNOWLEDGMENTS: The author is grateful to the university for encouraging innovation in education.

  3. GPU/MIC Acceleration of the LHC High Level Trigger to Extend the Physics Reach at the LHC

    SciTech Connect

    Halyo, Valerie; Tully, Christopher

    2015-04-14

    The quest for rare new physics phenomena leads the PI [3] to propose evaluation of coprocessors based on Graphics Processing Units (GPUs) and the Intel Many Integrated Core (MIC) architecture for integration into the trigger system at LHC. This will require development of a new massively parallel implementation of the well known Combinatorial Track Finder which uses the Kalman Filter to accelerate processing of data from the silicon pixel and microstrip detectors and reconstruct the trajectory of all charged particles down to momentums of 100 MeV. It is expected to run at least one order of magnitude faster than an equivalent algorithm on a quad core CPU for extreme pileup scenarios of 100 interactions per bunch crossing. The new tracking algorithms will be developed and optimized separately on the GPU and Intel MIC and then evaluated against each other for performance and power efficiency. The results will be used to project the cost of the proposed hardware architectures for the HLT server farm, taking into account the long term projections of the main vendors in the market (AMD, Intel, and NVIDIA) over the next 10 years. Extensive experience and familiarity of the PI with the LHC tracker and trigger requirements led to the development of a complementary tracking algorithm that is described in [arxiv: 1305.4855], [arxiv: 1309.6275] and preliminary results accepted to JINST.

  4. 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…

  5. Community Petascale Project for Accelerator Science and Simulation: Advancing Computational Science for Future Accelerators and Accelerator Technologies

    SciTech Connect

    Spentzouris, P.; Cary, J.; McInnes, L.C.; Mori, W.; Ng, C.; Ng, E.; Ryne, R.; /LBL, Berkeley

    2011-11-14

    The design and performance optimization of particle accelerators are essential for the success of the DOE scientific program in the next decade. Particle accelerators are very complex systems whose accurate description involves a large number of degrees of freedom and requires the inclusion of many physics processes. Building on the success of the SciDAC-1 Accelerator Science and Technology project, the SciDAC-2 Community Petascale Project for Accelerator Science and Simulation (ComPASS) is developing a comprehensive set of interoperable components for beam dynamics, electromagnetics, electron cooling, and laser/plasma acceleration modelling. ComPASS is providing accelerator scientists the tools required to enable the necessary accelerator simulation paradigm shift from high-fidelity single physics process modeling (covered under SciDAC1) to high-fidelity multiphysics modeling. Our computational frameworks have been used to model the behavior of a large number of accelerators and accelerator R&D experiments, assisting both their design and performance optimization. As parallel computational applications, the ComPASS codes have been shown to make effective use of thousands of processors. ComPASS is in the first year of executing its plan to develop the next-generation HPC accelerator modeling tools. ComPASS aims to develop an integrated simulation environment that will utilize existing and new accelerator physics modules with petascale capabilities, by employing modern computing and solver technologies. The ComPASS vision is to deliver to accelerator scientists a virtual accelerator and virtual prototyping modeling environment, with the necessary multiphysics, multiscale capabilities. The plan for this development includes delivering accelerator modeling applications appropriate for each stage of the ComPASS software evolution. Such applications are already being used to address challenging problems in accelerator design and optimization. The ComPASS organization

  6. Investigation of Problem Solving Ability of Students in School of Physical Education and Sports (Kafkas University Sample)

    ERIC Educational Resources Information Center

    Ozmutlu, Ilker

    2014-01-01

    The aim of this research is to examine the problem solving abilities of School of Physical Education and Sports students. To achieve this aim, in the academic year 2013-2014, a research group did a study of 433 students of the School of Physical Education and Sports, Kafkas University. This sample consisted of 184 female and 249 male students.…

  7. Correlations of Students' Grades, Expectations, Epistemological Beliefs and Demographics in a Problem-Based Introductory Physics Course

    ERIC Educational Resources Information Center

    Sahin, Mehmet

    2009-01-01

    The purpose of this study was to determine the predictors of student grades in introductory physics courses utilizing problem-based learning (PBL) approach and traditional lecturing. The study employed correlational/predictive methods to investigate and describe/explain relationships of students' physics grades with their expectations, attitudes,…

  8. Sociological Health Problems: Individualized Incentive Program Modules for Physically Disabled Students for Grades Kindergarten Through Twelve. Teacher's Edition.

    ERIC Educational Resources Information Center

    Reggio, Kathryn D.; And Others

    Presented is the second in a series of modules from a project to adapt the New York State Health Education curriculum for physically disabled students (grades K-12). An introductory section to the volume on sociological health problems provides definitions and summaries about nine physically disabling conditions and briefly considers activities at…

  9. Differences in the Problem Solving of Stronger and Weaker Novices in Physics: Knowledge, Strategies, or Knowledge Structure?

    ERIC Educational Resources Information Center

    Zajchowski, Richard; Martin, Jack

    1993-01-01

    Investigated the extent to which differences in problem-solving performance of stronger and weaker novices in physics arise from differences in amount of domain knowledge, in how domain knowledge is organized, and in the strategic application of domain knowledge. Differences were observed in how 10 university physics students solved easy and…

  10. The Effect of Hints and Model Answers in a Student-Controlled Problem-Solving Program for Secondary Physics Education

    ERIC Educational Resources Information Center

    Pol, Henk J.; Harskamp, Egbert G.; Suhre, Cor J. M.; Goedhart, Martin J.

    2008-01-01

    Many students experience difficulties in solving applied physics problems. Most programs that want students to improve problem-solving skills are concerned with the development of content knowledge. Physhint is an example of a student-controlled computer program that supports students in developing their strategic knowledge in combination with…

  11. Comparison of PASCAL and FORTRAN for solving problems in the physical sciences

    NASA Technical Reports Server (NTRS)

    Watson, V. R.

    1981-01-01

    The paper compares PASCAL and FORTRAN for problem solving in the physical sciences, due to requests NASA has received to make PASCAL available on the Numerical Aerodynamic Simulator (scheduled to be operational in 1986). PASCAL disadvantages include the lack of scientific utility procedures equivalent to the IBM scientific subroutine package or the IMSL package which are available in FORTRAN. Advantages include a well-organized, easy to read and maintain writing code, range checking to prevent errors, and a broad selection of data types. It is concluded that FORTRAN may be the better language, although ADA (patterned after PASCAL) may surpass FORTRAN due to its ability to add complex and vector math, and the specify the precision and range of variables.

  12. Fold prediction problem: the application of new physical and physicochemical-based features.

    PubMed

    Dehzangi, Abdollah; Phon-Amnuaisuk, Somnuk

    2011-02-01

    One of the most important goals in bioinformatics is the ability to predict tertiary structure of a protein from its amino acid sequence. In this paper, new feature groups based on the physical and physicochemical properties of amino acids (size of the amino acids' side chains, predicted secondary structure based on normalized frequency of β-Strands, Turns, and Reverse Turns) are proposed to tackle this task. The proposed features are extracted using a modified feature extraction method adapted from Dubchak et al. To study the effectiveness of the proposed features and the modified feature extraction method, AdaBoost.M1, Multi Layer Perceptron (MLP), and Support Vector Machine (SVM) that have been commonly and successfully applied to the protein folding problem are employed. Our experimental results show that the new feature groups altogether with the modified feature extraction method are capable of enhancing the protein fold prediction accuracy better than the previous works found in the literature.

  13. [Information as physical factor: problems of measurement, hygienic assessment and IT-automation].

    PubMed

    Denisov, É I; Prokopenko, L V; Eremin, A L; Kur'erov, N N; Bodiakin, V I; Stepanian, I V

    2014-01-01

    The increasing flow of information, speeding up the progress of society, can impact the health that puts the task of its hygienic reglamentation. The physical aspects of information, parameters and units of quantities, aspects of measurement and evaluation with account of information quantity and quality as well as criteria of its permissible and optimal levels are considered. The results of measurements of quantity of text information produced per year on computer in 17 occupations of 10 economic sectors are presented. The principle of IT-automation of operator's work and of dynamic monitoring is proposed. On the basis of research performed the glossary of terms and guide on the problem with computer support are elaborated for the accumulation of experience and clarification of prospects.

  14. On determining important aspects of mathematical models: Application to problems in physics and chemistry

    NASA Technical Reports Server (NTRS)

    Rabitz, Herschel

    1987-01-01

    The use of parametric and functional gradient sensitivity analysis techniques is considered for models described by partial differential equations. By interchanging appropriate dependent and independent variables, questions of inverse sensitivity may be addressed to gain insight into the inversion of observational data for parameter and function identification in mathematical models. It may be argued that the presence of a subset of dominantly strong coupled dependent variables will result in the overall system sensitivity behavior collapsing into a simple set of scaling and self similarity relations amongst elements of the entire matrix of sensitivity coefficients. These general tools are generic in nature, but herein their application to problems arising in selected areas of physics and chemistry is presented.

  15. An investigation into the effectiveness of problem-based learning in a physical chemistry laboratory course

    NASA Astrophysics Data System (ADS)

    Gürses, Ahmet; Açıkyıldız, Metin; Doğar, Çetin; Sözbilir, Mustafa

    2007-04-01

    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 pre-test post-test. Four experiments, covering the topics adsorption, viscosity, surface tension and conductivity were performed using a PBL approach in the fall semester of the 2003/04 academic year at Kazim Karabekir Education Faculty of Atatürk University. Each experiment was done over a three week period. A total of 40 students, 18 male and 22 female, participated in the study. Students took the Physical Chemistry Laboratory Concept Test (PCLCT), Attitudes towards Chemistry Laboratory (ATCL) questionnaire and Science Process Skills Test (SPST) as pre and post-tests. In addition, the effectiveness of the PBL approach was also determined through four different scales; Scales Specific to Students’ Views of PBL. A statistically significant difference between the students’ academic achievement and scientific process skills at p

  16. Development of the applied mathematics originating from the group theory of physical and mathematical problems

    SciTech Connect

    Hyman, J.; Beyer, W.; Louck, J.; Metropolis, N.

    1996-07-01

    This is the final report of a three-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Group theoretical methods are a powerful tool both in their applications to mathematics and to physics. The broad goal of this project was to use such methods to develop the implications of group (symmetry) structures underlying models of physical systems, as well as to broaden the understanding of simple models of chaotic systems. The main thrust was to develop further the complex mathematics that enters into many-particle quantum systems with special emphasis on the new directions in applied mathematics that have emerged and continue to surface in these studies. In this area, significant advances in understanding the role of SU(2) 3nj-coefficients in SU(3) theory have been made and in using combinatoric techniques in the study of generalized Schur functions, discovered during this project. In the context of chaos, the study of maps of the interval and the associated theory of words has led to significant discoveries in Galois group theory, to the classification of fixed points, and to the solution of a problem in the classification of DNA sequences.

  17. The Hamiltonian Mechanics of Stochastic Acceleration

    SciTech Connect

    Burby, J. W.

    2013-07-17

    We show how to nd the physical Langevin equation describing the trajectories of particles un- dergoing collisionless stochastic acceleration. These stochastic di erential equations retain not only one-, but two-particle statistics, and inherit the Hamiltonian nature of the underlying microscopic equations. This opens the door to using stochastic variational integrators to perform simulations of stochastic interactions such as Fermi acceleration. We illustrate the theory by applying it to two example problems.

  18. Ultimate gradient in solid-state accelerators

    SciTech Connect

    Whittum, D.H.

    1999-07-01

    We recall the motivation for research in high-gradient acceleration and the problems posed by a compact collider. We summarize the phenomena known to appear in operation of a solid-state structure with large fields, and research relevant to the question of the ultimate gradient. We take note of new concepts, and examine one in detail, a miniature particle accelerator based on an active millimeter-wave circuit and parallel particle beams. {copyright} {ital 1999 American Institute of Physics.}

  19. The effect of introducing computers into an introductory physics problem-solving laboratory

    NASA Astrophysics Data System (ADS)

    McCullough, Laura Ellen

    2000-10-01

    Computers are appearing in every type of classroom across the country. Yet they often appear without benefit of studying their effects. The research that is available on computer use in classrooms has found mixed results, and often ignores the theoretical and instructional contexts of the computer in the classroom. The University of Minnesota's physics department employs a cooperative-group problem solving pedagogy, based on a cognitive apprenticeship instructional model, in its calculus-based introductory physics course. This study was designed to determine possible negative effects of introducing a computerized data-acquisition and analysis tool into this pedagogy as a problem-solving tool for students to use in laboratory. To determine the effects of the computer tool, two quasi-experimental treatment groups were selected. The computer-tool group (N = 170) used a tool, designed for this study (VideoTool), to collect and analyze motion data in the laboratory. The control group (N = 170) used traditional non-computer equipment (spark tapes and Polaroid(TM) film). The curriculum was kept as similar as possible for the two groups. During the ten week academic quarter, groups were examined for effects on performance on conceptual tests and grades, attitudes towards the laboratory and the laboratory tools, and behaviors within cooperative groups. Possible interactions with gender were also examined. Few differences were found between the control and computer-tool groups. The control group received slightly higher scores on one conceptual test, but this difference was not educationally significant. The computer-tool group had slightly more positive attitudes towards using the computer tool than their counterparts had towards the traditional tools. The computer-tool group also perceived that they spoke more frequently about physics misunderstandings, while the control group felt that they discussed equipment difficulties more often. This perceptual difference interacted

  20. The Role of Physical Representations in Solving Number Problems: A Comparison of Young Children's Use of Physical and Virtual Materials

    ERIC Educational Resources Information Center

    Manches, Andrew; O'Malley, Claire; Benford, Steve

    2010-01-01

    This research aims to explore the role of physical representations in young children's numerical learning then identify the benefits of using a graphical interface in order to understand the potential for developing interactive technologies in this domain. Three studies are reported that examined the effect of using physical representations…

  1. Space or Physics? Children Use Physical Reasoning to Solve the Trap Problem from 2.5 Years of Age

    ERIC Educational Resources Information Center

    Seed, Amanda M.; Call, Josep

    2014-01-01

    By 3 years of age, children can solve tasks involving physical principles such as locating a ball that rolled down a ramp behind an occluder by the position of a partially visible solid wall (Berthier, DeBlois, Poirer, Novak, & Clifton, 2000; Hood, Carey, & Prasada, 2000). However, the extent to which children use physical information (the…

  2. Cardiac acceleration at the onset of exercise: a potential parameter for monitoring progress during physical training in sports and rehabilitation.

    PubMed

    Hettinga, Florentina J; Monden, Paul G; van Meeteren, Nico L U; Daanen, Hein A M

    2014-05-01

    There is a need for easy-to-use methods to assess training progress in sports and rehabilitation research. The present review investigated whether cardiac acceleration at the onset of physical exercise (HRonset) can be used as a monitoring variable. The digital databases of Scopus and PubMed were searched to retrieve studies investigating HRonset. In total 652 studies were retrieved. These articles were then classified as having emphasis on HRonset in a sports or rehabilitation setting, which resulted in 8 of 112 studies with a sports application and 6 of 68 studies with a rehabilitation application that met inclusion criteria. Two co-existing mechanisms underlie HRonset: feedforward (central command) and feedback (mechanoreflex, metaboreflex, baroreflex) control. A number of studies investigated HRonset during the first few seconds of exercise (HRonsetshort), in which central command and the mechanoreflex determine vagal withdrawal, the major mechanism by which heart rate (HR) increases. In subsequent sports and rehabilitation studies, interest focused on HRonset during dynamic exercise over a longer period of time (HRonsetlong). Central command, mechanoreflexes, baroreflexes, and possibly metaboreflexes contribute to HRonset during the first seconds and minutes of exercise, which in turn leads to further vagal withdrawal and an increase in sympathetic activity. HRonset has been described as the increase in HR compared with resting state (delta HR) or by exponential modeling, with measurement intervals ranging from 0-4 s up to 2 min. Delta HR was used to evaluate HRonsetshort over the first 4 s of exercise, as well as for analyzing HRonsetlong. In exponential modeling, the HR response to dynamic exercise is biphasic, consisting of fast (parasympathetic, 0-10 s) and slow (sympathetic, 1-4 min) components. Although available studies differed largely in measurement protocols, cross-sectional and longitudinal training studies showed that studies analyzing HRonset

  3. The relation between tilt table and acceleration-tolerance and their dependence on stature and physical fitness

    NASA Technical Reports Server (NTRS)

    Klein, K. E.; Backhausen, F.; Bruner, H.; Eichhorn, J.; Jovy, D.; Schotte, J.; Vogt, L.; Wegman, H. M.

    1980-01-01

    A group of 12 highly trained athletes and a group of 12untrained students were subjected to passive changes of position on a tilt table and positive accelerations in a centrifuge. During a 20 min tilt, including two additional respiratory maneuvers, the number of faints and average cardiovascular responses did not differ significantly between the groups. During linear increase of acceleration, the average blackout level was almost identical in both groups. Statistically significant coefficients of product-moment correlation for various relations were obtained. The coefficient of multiple determination computed for the dependence of acceleration tolerance on heart-eye distance and systolic blood pressure at rest allows the explanation of almost 50% of the variation of acceleration tolerance. The maximum oxygen uptake showed the expected significant correlation to the heart rate at rest, but not the acceleration tolerance, or to the cardiovascular responses to tilting.

  4. Testing Posttraumatic Stress as a Mediator of Physical, Sexual, and Psychological Intimate Partner Violence and Substance Problems Among Women

    PubMed Central

    Sullivan, Tami P.; Cavanaugh, Courtenay E.; Buckner, Julia D.; Edmondson, Donald

    2010-01-01

    This study examined whether posttraumatic stress specifically resulting from intimate partner violence (IPV-related posttraumatic stress) mediated relationships between types of IPV and drug and alcohol problems among 212 women currently experiencing IPV. Six-month prevalence was high for drug use (48%) and alcohol use (59%). Structural equation modeling revealed that the frequency of physical, sexual, and psychological IPV were significantly and positively related to greater IPV-related posttraumatic stress, and IPV-related posttraumatic stress was significantly and positively related to drug problems. Further, IPV-related posttraumatic stress mediated the relationships between physical IPV and drug problems and psychological IPV and drug problems. Findings suggest that prevention and intervention efforts targeting posttraumatic stress among IPV-exposed women may reduce drug problems in this population. PMID:19960546

  5. Quick-hardening problems are eliminated with spray gun modification which mixes resin and accelerator liquids during application

    NASA Technical Reports Server (NTRS)

    Johnson, O. W.

    1964-01-01

    A modified spray gun, with separate containers for resin and additive components, solves the problems of quick hardening and nozzle clogging. At application, separate atomizers spray the liquids in front of the nozzle face where they blend.

  6. Application of Effective Field Theories to Problems in Nuclear and Hadronic Physics

    NASA Astrophysics Data System (ADS)

    Mereghetti, Emanuele

    The Effective Field Theory formalism is applied to the study of problems in hadronic and nuclear physics. We develop a framework to study the exclusive two-body decays of bottomonium into two charmed mesons and apply it to study the decays of the C-even bottomonia. Using a sequence of effective field theories, we take advantage of the separation between the scales contributing to the decay processes, 2mb >> mc >> ΛQCD. We prove that, at leading order in the EFT power counting, the decay rate factorizes into the convolution of two perturbative matching coefficients and three non-perturbative matrix elements, one for each hadron. We calculate the relations between the decay rate and non-perturbative bottomonium and D-meson matrix elements at leading order, with next-to-leading log resummation. The phenomenological implications of these relations are discussed. At lower energies, we use Chiral Perturbation Theory and nuclear EFTs to set up a framework for the study of time reversal (T) symmetry in one- and few-nucleon problems. We consider T violation from the QCD theta term and from all the possible dimension 6 operators, expressed in terms of light quarks, gluons and photons, that can be added to the Standard Model Lagrangian. We construct the low energy chiral Lagrangian stemming from different TV sources, and derive the implications for the nucleon Electric Dipole Form Factor and the deuteron T violating electromagnetic Form Factors. Finally, with an eye to applications to nuclei with A ≥ 2, we construct the T violating nucleon-nucleon potential from different sources of T violation.

  7. Unfortunate Outcomes of a "Funny" Physics Problem: Some Eye-Opening YouTube Comments

    ERIC Educational Resources Information Center

    Slisko, Josip; Dykstra, Dewey, Jr.

    2011-01-01

    The impressions we make as instructors of physics can affect student learning and public perception of physics teachers, physics as an academic subject, and physics as a profession. There are many sources from which we can collect evidence of these impressions. Among these sources are online public forums such as those at the Internet site known…

  8. Physical Abuse, Cognitive and Emotional Processes, and Aggressive/Disruptive Behavior Problems

    ERIC Educational Resources Information Center

    Teisl, Michael; Cicchetti, Dante

    2008-01-01

    Cognitive and emotional processes were examined in maltreated children with a history of physical abuse (n = 76), children with a history of maltreatment other than physical abuse (i.e., sexual abuse, physical neglect, and emotional maltreatment; n = 91), and a group of non-maltreated comparison children (N = 100). Physical abuse was associated…

  9. Women living with a history of physical and/or sexual abuse, substance use, and mental health problems.

    PubMed

    Nehls, Nadine; Sallmann, Jolanda

    2005-03-01

    Most researchers have studied physical and/or sexual abuse, substance use, and mental health problems separately or as a dual diagnosis, and from a theory-driven, empirical perspective. In this study, the authors examined these three phenomena together and from a phenomenological perspective. Thirty women each participated in an individual interview about living with a history of physical and/or sexual abuse, substance use, and mental health problems. Using a hermeneutic approach, a team of researchers analyzed the transcribed interview texts. They identified three themes: (a) being thrown: the cycle of abuse; (b) living life fearfully: a restricted world; and (c) helping: hearing my story. The results are significant, in that they challenge current assumptions underlying health care for women with histories of physical and/or sexual abuse, substance use, and mental health problems. PMID:15761105

  10. Using data from automatic planetary stations for solving problems in astronomy and space physics

    NASA Astrophysics Data System (ADS)

    Stoeva, Penka; Stoev, Alexey; Bojurova, Eva

    The specific nature of the Astronomy and Space Physics problems promote students' interest in the relevant sciences and provoke their creativity. It is illustrated by numerous examples of positive response from the participants in the Astronomy Olympiad to extraordinary moments in problems, especially those related to space flight and scientific data and photographs from satellites and automatic interplanetary stations (AIS). Jupiter's satellite Io is one of the satellites with the highest volcano activity in the solar system. So far, the volcanoes of Io were photographed for a short time only by the interplanetary stations Voyager 1 and Galileo - sent by NASA, and New Horizons of ESA. By monitoring these often erupting volcanoes, however, one can quickly gather detailed information and establish methods for prediction of eruptions, including the Earth's volcanoes. This could push forward research on volcanism in the Solar system. Therefore, this issue was used for creation conditions for problems in astronomy. The report shows how through measurements on images of Io taken with AIS heights of the jets emitted by volcanoes are defined. Knowing the mass and radius of the satellite initial speed of the emitted particles is evaluated. Similarly, the initial rate of discharge of earth volcanoes and ice geysers on Saturn's satellite Enceladus are also evaluated. An attempt is made to explain the rings of ejection around the volcanoes on Io. The ratio of the diameter of the dispersion of the substance to the height of the stream is studied. Actually, maximum speed of the particles is evaluated as the boundaries of the volcanic "fountain" are determined by the fast moving particles reaching maximal height. The observed ratio is compared with the theoretical one derived by the students. The results show that although the volcanoes of Io , Earth's volcanoes and even ice geysers of Enceladus operate under very different conditions and arise from different causes, the initial

  11. Verification of Unstructured Mesh Capabilities in MCNP6 for Reactor Physics Problems

    SciTech Connect

    Burke, Timothy P.; Martz, Roger L.; Kiedrowski, Brian C.; Martin, William R.

    2012-08-22

    New unstructured mesh capabilities in MCNP6 (developmental version during summer 2012) show potential for conducting multi-physics analyses by coupling MCNP to a finite element solver such as Abaqus/CAE[2]. Before these new capabilities can be utilized, the ability of MCNP to accurately estimate eigenvalues and pin powers using an unstructured mesh must first be verified. Previous work to verify the unstructured mesh capabilities in MCNP was accomplished using the Godiva sphere [1], and this work attempts to build on that. To accomplish this, a criticality benchmark and a fuel assembly benchmark were used for calculations in MCNP using both the Constructive Solid Geometry (CSG) native to MCNP and the unstructured mesh geometry generated using Abaqus/CAE. The Big Ten criticality benchmark [3] was modeled due to its geometry being similar to that of a reactor fuel pin. The C5G7 3-D Mixed Oxide (MOX) Fuel Assembly Benchmark [4] was modeled to test the unstructured mesh capabilities on a reactor-type problem.

  12. The effects of learner-generated representations versus computer-generated representations on physics problem solving

    NASA Astrophysics Data System (ADS)

    Price, Gwyneth A.

    In this study, multiple external representations and Generative Learning Theory were used to design instruction that would facilitate physics learning. Specifically, the study looks at the learning differences that may occur when students are engaged in generating a graphical representation as compared to being presented with a computer-generated graph. It is hypothesized that by generating the graphical representation students will be able to overcome obstacles to integration and determine the relationships involved within a representation. In doing so, students will build a more complete mental model of the situation and be able to more readily use this information in transfer situations, thus improving their problem solving ability. Though the results of this study do not lend strong support for the hypothesis, the results are still informative and encouraging. Though several of the obstacles associated with learning from multiple representations such as cognitive load were cause for concern, those students with appropriate prior knowledge and familiarity with graphical representations were able to benefit from the generative activity. This finding indicates that if the issues are directly addressed within instruction, it may be that all students may be able to benefit from being actively engaged in generating representations.

  13. Attention Problems Mediate the Association between Severity of Physical Abuse and Aggressive Behavior in a Sample of Maltreated Early Adolescents.

    PubMed

    Garrido, Edward F; Taussig, Heather N; Culhane, Sara E; Raviv, Tali

    2011-10-01

    Empirical evidence has accumulated documenting an association between childhood physical abuse and aggressive behavior. Relatively fewer studies have explored possible mediating mechanisms that may explain this association. The purpose of the current study was to examine whether caregiver- and youth-reported attention problems mediate the association between physical abuse severity and aggressive behavior. A sample of 240 maltreated early adolescents (ages 9-11) and their caregivers were interviewed within 14 months of being removed from the home. Results from multiple regression analyses indicated that caregiver- and youth-reported attention problems were partial mediators of the association between physical abuse severity and aggressive behavior. These associations were significant even after controlling for children's intellectual functioning, sex, age, and severity of other maltreatment types. Possible explanations for the detrimental impact of physical abuse on behavior are discussed, along with the implications of the current study's results for interventions aimed at reducing early adolescent aggressive behavior. PMID:21966081

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

    PubMed

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

    2016-01-01

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

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

    PubMed Central

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

    2016-01-01

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

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

    PubMed

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

    2016-01-01

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

  17. Effects of Problem-Based Learning on University Students' Epistemological Beliefs About Physics and Physics Learning and Conceptual Understanding of Newtonian Mechanics

    NASA Astrophysics Data System (ADS)

    Sahin, Mehmet

    2010-06-01

    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 university students (PBL = 55, traditional = 69) enrolled in a calculus-based introductory physics class. Students' beliefs about physics and physics learning and their physics conceptual understanding were measured with the Colorado Learning Attitudes about Science Survey (CLASS) and the Force Concept Inventory (FCI), respectively. Repeated measures analysis of variance of how PBL influence beliefs and conceptual understanding were performed. The PBL group showed significantly higher conceptual learning gains in FCI than the traditional group. PBL approach showed no influence on students' beliefs about physics; both groups displayed similar beliefs. A significant positive correlation was found between beliefs and conceptual understanding. Students with more expert-like beliefs at the beginning of the semester were more likely to obtain higher conceptual understanding scores at the end of the semester. Suggestions are presented regarding the implementation of the PBL approach.

  18. Unfortunate Outcomes of a ``Funny'' Physics Problem: Some Eye-Opening YouTube Comments

    NASA Astrophysics Data System (ADS)

    Slisko, Josip; Dykstra, Dewey

    2011-02-01

    The impressions we make as instructors of physics can affect student learning and public perception of physics teachers, physics as an academic subject, and physics as a profession. There are many sources from which we can collect evidence of these impressions. Among these sources are online public forums such as those at the Internet site known as YouTube. Whether we are proud of these impressions we make or not, we should consider how constructive these impressions are for our students' physics learning and their impact on the public perception of physics and the community of physicists.

  19. Problems of Quantum Theory may be Solved by an Emulation Theory of Quantum Physics

    NASA Astrophysics Data System (ADS)

    Woesler, Richard

    2005-02-01

    The emulation interpretation of quantum theory is described which may solve problems of the Copenhagen interpretation finally. According to Kolmogorov complexity theory it is conceivable that a bit string exists encoding our world which can be computed by an appropriate generalized Turing machine. In this case the computation would emulate the world, therefore this can be called an emulation theory of quantum physics, and the emulation interpretation of quantum theory. The probability of a string is dominated by the probabilities of its shortest programs which is known as the `coding theorem'. This leads to the suggestion that there may be a relatively short shortest program by which our world may be run. This suggestion appears to be in accordance with our world. The world exhibits a number of symmetries. It is plausible that the shortest algorithm for our special world is shorter than those for worlds where symmetries are broken more often than in our world, because each further deviation from a symmetry has to be encoded within the algorithm which would enlarge its length. Therefore, laws of physics may be identical rather globally in spacetime. Further, in the Copenhagen interpretation of quantum theory it is defined, how to compute probabilities for, e.g., measurement results when conducting measurements on variables of quantum systems. In a completely satisfactory theory of everything this would not be sufficient, but such a theory should give a reason why the values of the probabilities seem, as far as it is known, to be identical also in all different regions of the observed world. The emulation interpretation suggests that all deviations from this symmetry of the probabilities would enlarge the shortest program of the world, and, therefore, we would probably not live in a world with such deviations. A second question arises from the attempt to combine the theory of black holes, thermodynamics and quantum theory. Bekenstein derives a holography principle

  20. Physics faculty beliefs and values about the teaching and learning of problem solving. I. Mapping the common core

    NASA Astrophysics Data System (ADS)

    Yerushalmi, E.; Henderson, C.; Heller, K.; Heller, P.; Kuo, V.

    2007-12-01

    In higher education, instructors’ choices of both curricular material and pedagogy are determined by their beliefs about learning and teaching, the values of their profession, and perceived external constraints. Dissemination of research-based educational reforms is based on assumptions about that mental structure. This study reports the initial phase of an investigation of the beliefs and values of physics professors as they relate to the teaching and learning of problem solving in introductory physics. Based on an analysis of a series of structured interviews with six college physics faculty, a model of a common structure of such beliefs for all physics faculty teaching introductory physics was constructed. This preliminary model, when tested and modified by future research, can be used by curriculum developers to design materials, pedagogy, and professional development that gain acceptance among instructors.