Sample records for accelerator physics problems

  1. Compensation Techniques in Accelerator Physics

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

    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. Twomore » 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.« less

  2. 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.

  3. 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.

  4. An introduction to the physics of high energy accelerators

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

    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 knowledgemore » 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.« less

  5. 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

  6. 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.

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

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

    Siemann, R.H.; /SLAC

    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.

  8. Physics in ;Real Life;: Accelerator-based Research with Undergraduates

    NASA Astrophysics Data System (ADS)

    Klay, J. L.

    All undergraduates in physics and astronomy should have access to significant research experiences. When given the opportunity to tackle challenging open-ended problems outside the classroom, students build their problem-solving skills in ways that better prepare them for the workplace or future research in graduate school. Accelerator-based research on fundamental nuclear and particle physics can provide a myriad of opportunities for undergraduate involvement in hardware and software development as well as ;big data; analysis. The collaborative nature of large experiments exposes students to scientists of every culture and helps them begin to build their professional network even before they graduate. This paper presents an overview of my experiences - the good, the bad, and the ugly - engaging undergraduates in particle and nuclear physics research at the CERN Large Hadron Collider and the Los Alamos Neutron Science Center.

  9. Differences in the Processes of Solving Physics Problems between Good Physics Problem Solvers and Poor Physics Problem Solvers.

    ERIC Educational Resources Information Center

    Finegold, M.; Mass, R.

    1985-01-01

    Good problem solvers and poor problem solvers in advanced physics (N=8) were significantly different in their ability in translating, planning, and physical reasoning, as well as in problem solving time; no differences in reliance on algebraic solutions and checking problems were noted. Implications for physics teaching are discussed. (DH)

  10. 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.

  11. Computational Accelerator Physics. Proceedings

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

    Bisognano, J.J.; Mondelli, A.A.

    1997-04-01

    The sixty two papers appearing in this volume were presented at CAP96, the Computational Accelerator Physics Conference held in Williamsburg, Virginia from September 24{minus}27,1996. Science Applications International Corporation (SAIC) and the Thomas Jefferson National Accelerator Facility (Jefferson lab) jointly hosted CAP96, with financial support from the U.S. department of Energy`s Office of Energy Research and the Office of Naval reasearch. Topics ranged from descriptions of specific codes to advanced computing techniques and numerical methods. Update talks were presented on nearly all of the accelerator community`s major electromagnetic and particle tracking codes. Among all papers, thirty of them are abstracted formore » the Energy Science and Technology database.(AIP)« less

  12. Solution Strategies for Constant Acceleration Problems

    ERIC Educational Resources Information Center

    Wheaton, S. M.; Binder, P.-M.

    2017-01-01

    We discuss strategies for the general solution of single-step 1D constant acceleration problems. In a slightly restricted form, these problems have five variables (?"x," "v[subscript 0]," "v," "a" and "t") and two independent equations, so three variables must be given to solve for the other two,…

  13. High Energy Density Physics and Exotic Acceleration Schemes

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

    Cowan, T.; /General Atomics, San Diego; Colby, E.

    2005-09-27

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

  14. Acceleration methods for multi-physics compressible flow

    NASA Astrophysics Data System (ADS)

    Peles, Oren; Turkel, Eli

    2018-04-01

    In this work we investigate the Runge-Kutta (RK)/Implicit smoother scheme as a convergence accelerator for complex multi-physics flow problems including turbulent, reactive and also two-phase flows. The flows considered are subsonic, transonic and supersonic flows in complex geometries, and also can be either steady or unsteady flows. All of these problems are considered to be a very stiff. We then introduce an acceleration method for the compressible Navier-Stokes equations. We start with the multigrid method for pure subsonic flow, including reactive flows. We then add the Rossow-Swanson-Turkel RK/Implicit smoother that enables performing all these complex flow simulations with a reasonable CFL number. We next discuss the RK/Implicit smoother for time dependent problem and also for low Mach numbers. The preconditioner includes an intrinsic low Mach number treatment inside the smoother operator. We also develop a modified Roe scheme with a corresponding flux Jacobian matrix. We then give the extension of the method for real gas and reactive flow. Reactive flows are governed by a system of inhomogeneous Navier-Stokes equations with very stiff source terms. The extension of the RK/Implicit smoother requires an approximation of the source term Jacobian. The properties of the Jacobian are very important for the stability of the method. We discuss what the chemical physics theory of chemical kinetics tells about the mathematical properties of the Jacobian matrix. We focus on the implication of the Le-Chatelier's principle on the sign of the diagonal entries of the Jacobian. We present the implementation of the method for turbulent flow. We use a two RANS turbulent model - one equation model - Spalart-Allmaras and a two-equation model - k-ω SST model. The last extension is for two-phase flows with a gas as a main phase and Eulerian representation of a dispersed particles phase (EDP). We present some examples for such flow computations inside a ballistic evaluation

  15. 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).

  16. Advanced Computing Tools and Models for Accelerator Physics

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

    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.

  17. 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…

  18. Fifty years of accelerator based physics at Chalk River

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

    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.

  19. Analytical tools in accelerator physics

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

    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 andmore » 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.« less

  20. Theoretical and Experimental Studies in Accelerator Physics

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

    Rosenzweig, James

    This report describes research supported by the US Dept. of Energy Office of High Energy Physics (OHEP), performed by the UCLA Particle Beam Physics Laboratory (PBPL). The UCLA PBPL has, over the last two decades-plus, played a critical role in the development of advanced accelerators, fundamental beam physics, and new applications enabled by these thrusts, such as new types of accelerator-based light sources. As the PBPL mission is broad it is natural that it has been grown within the context of the accelerator science and technology stewardship of the OHEP. Indeed, steady OHEP support for the program has always beenmore » central to the success of the PBPL; it has provided stability, and above all has set the over-arching themes for our research directions, which have producing over 500 publications (>120 in high level journals). While other agency support has grown notably in recent years, permitting more vigorous pursuit of the program, it is transient by comparison. Beyond permitting program growth in a time of flat OHEP budgets, the influence of other agency missions is found in push to adapt advanced accelerator methods to applications, in light of the success the field has had in proof-of-principle experiments supported first by the DoE OHEP. This three-pronged PBPL program — advanced accelerators, fundamental beam physics and technology, and revolutionary applications — has produced a generation of students that have had a profound affect on the US accelerator physics community. PBPL graduates, numbering 28 in total, form a significant population group in the accelerator community, playing key roles as university faculty, scientific leaders in national labs (two have been named Panofsky Fellows at SLAC), and vigorous proponents of industrial application of accelerators. Indeed, the development of advanced RF, optical and magnet technology at the PBPL has led directly to the spin-off company, RadiaBeam Technologies, now a leading industrial

  1. Multipactor Physics, Acceleration, and Breakdown in Dielectric-Loaded Accelerating Structures

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

    Fischer, Richard P.; Gold, Steven H.

    2016-07-01

    The objective of this 3-year program is to study the physics issues associated with rf acceleration in dielectric-loaded accelerating (DLA) structures, with a focus on the key issue of multipactor loading, which has been found to cause very significant rf power loss in DLA structures whenever the rf pulsewidth exceeds the multipactor risetime (~10 ns). The experiments are carried out in the X-band magnicon laboratory at the Naval Research Laboratory (NRL) in collaboration with Argonne National Laboratory (ANL) and Euclid Techlabs LLC, who develop the test structures with support from the DoE SBIR program. There are two main elements inmore » the research program: (1) high-power tests of DLA structures using the magnicon output (20 MW @11.4 GHz), and (2) tests of electron acceleration in DLA structures using relativistic electrons from a compact X-band accelerator. The work during this period has focused on a study of the use of an axial magnetic field to suppress multipactor in DLA structures, with several new high power tests carried out at NRL, and on preparation of the accelerator for the electron acceleration experiments.« less

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

    NASA Technical Reports Server (NTRS)

    Skarda, J. Raymond

    1998-01-01

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

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

    NASA Astrophysics Data System (ADS)

    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.

  4. Physical condition for the slowing down of cosmic acceleration

    NASA Astrophysics Data System (ADS)

    Zhang, Ming-Jian; Xia, Jun-Qing

    2018-04-01

    The possible slowing down of cosmic acceleration was widely studied. However, judgment on this effect in different dark energy parameterizations was very ambiguous. Moreover, the reason of generating these uncertainties was still unknown. In the present paper, we analyze the derivative of deceleration parameter q‧ (z) using the Gaussian processes. This model-independent reconstruction suggests that no slowing down of acceleration is presented within 95% C.L. from the Union2.1 and JLA supernova data. However, q‧ (z) from the observational H (z) data is a little smaller than zero at 95% C.L., which indicates that future H (z) data may have a potential to test this effect. From the evolution of q‧ (z), we present an interesting constraint on the dark energy and observational data. The physical constraint clearly solves the problem of why some dark energy models cannot produce this effect in previous work. Comparison between the constraint and observational data also shows that most of current data are not in the allowed regions. This implies a reason of why current data cannot convincingly measure this effect.

  5. The effect of mathematical model development on the instruction of acceleration to introductory physics students

    NASA Astrophysics Data System (ADS)

    Sauer, Tim Allen

    The purpose of this study was to evaluate the effectiveness of utilizing student constructed theoretical math models when teaching acceleration to high school introductory physics students. The goal of the study was for the students to be able to utilize mathematical modeling strategies to improve their problem solving skills, as well as their standardized scientific and conceptual understanding. This study was based on mathematical modeling research, conceptual change research and constructivist theory of learning, all of which suggest that mathematical modeling is an effective way to influence students' conceptual connectiveness and sense making of formulaic equations and problem solving. A total of 48 students in two sections of high school introductory physics classes received constructivist, inquiry-based, cooperative learning, and conceptual change-oriented instruction. The difference in the instruction for the 24 students in the mathematical modeling treatment group was that they constructed every formula they needed to solve problems from data they collected. In contrast, the instructional design for the control group of 24 students allowed the same instruction with assigned problems solved with formulas given to them without explanation. The results indicated that the mathematical modeling students were able to solve less familiar and more complicated problems with greater confidence and mental flexibility than the control group students. The mathematical modeling group maintained fewer alternative conceptions consistently in the interviews than did the control group. The implications for acceleration instruction from these results were discussed.

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

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

    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 authorsmore » 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.« less

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

    NASA Astrophysics Data System (ADS)

    Barletta, William A.

    2012-02-01

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

  8. 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.

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

    NASA Astrophysics Data System (ADS)

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

    1997-02-01

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

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

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

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

    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 necessarymore » 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 Com

  11. Collection of solved problems in physics

    NASA Astrophysics Data System (ADS)

    Koupilová, ZdeÅka; Mandíková, Dana; Snětinová, Marie

    2017-01-01

    To solve physics problems is a key ability which students should reach during their physics education. Ten years ago we started to develop a Collection of fully solved problems. The structure of problems' solutions is specially designed to substitute tutor's help during lesson and encourage students to solve at least some parts of a problem independently. Nowadays the database contains about 770 fully solved problems in physics in Czech, more than 100 problems in Polish and more than 140 problems in English. Other problems are still being translated. Except for physics problems, the Collection has also a mathematical part, which contains more than 300 fully solved problems in mathematics. This paper follows the presentation of the Collection of solved problems from previous years and introduces a new interface of the Collection, its enhanced functionality, new topics, newly created interface for teachers, user feedback and plans for future development. The database is placed at the website of the Department of Physics Education, Faculty of Mathematics and Physics, Charles University in Prague, the links are: http://reseneulohy.cz/fyzika (Czech version); http://www.physicstasks.eu/ (English version).

  12. 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.

  13. Neutron physics with accelerators

    NASA Astrophysics Data System (ADS)

    Colonna, N.; Gunsing, F.; Käppeler, F.

    2018-07-01

    Neutron-induced nuclear reactions are of key importance for a variety of applications in basic and applied science. Apart from nuclear reactors, accelerator-based neutron sources play a major role in experimental studies, especially for the determination of reaction cross sections over a wide energy span from sub-thermal to GeV energies. After an overview of present and upcoming facilities, this article deals with state-of-the-art detectors and equipment, including the often difficult sample problem. These issues are illustrated at selected examples of measurements for nuclear astrophysics and reactor technology with emphasis on their intertwined relations.

  14. 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.

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

    NASA Astrophysics Data System (ADS)

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

    2015-02-01

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

  16. 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.

  17. 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.

  18. Female acceleration tolerance: effects of menstrual state and physical condition.

    PubMed

    Heaps, C L; Fischer, M D; Hill, R C

    1997-06-01

    The literature contains a paucity of information on female tolerance to high sustained acceleration. With women now flying high-performance aircraft, gender-specific factors that may affect female acceleration tolerance have become increasingly important. The purpose of this investigation was to determine how menstrual state and physical condition affect acceleration tolerance. We hypothesized the menstrual cycle would have no effect on acceleration tolerance and that a positive correlation would exist between physical fitness level and tolerance to high sustained acceleration. Centrifuge exposures on 8 female subjects consisted of a relaxed gradual-onset run (0.1 G.s-1) to the visual endpoint, a rapid-onset run (6 G.s-1) to +5 GZ for 15 s, and a +4.5 to +7 GZ simulated aerial combat maneuver (SACM) to physical exhaustion. Acceleration tolerance data were collected at onset of menstruation and 1, 2 and 3 weeks following the onset for two complete menstrual cycles. On separate days, body composition, anaerobic power output and peak oxygen uptake were determined. Retrospective data from 10 male subjects who had performed the +4.5 to +7 GZ SACM were analyzed and compared to these data. Analysis of variance revealed no significant difference in relaxed tolerance or SACM duration between the four selected menstrual cycle time points. Time-to-fatigue on the +4.5 to +7 GZ SACM was positively (p < or = 0.05) correlated with absolute fat-free mass (r = 0.87) and anaerobic power production (r = 0.76) in female subjects. However, when these variables were adjusted for total body mass, the significant correlations no longer existed. No correlation was found between SACM duration and absolute (L min-1) nor relative (ml.kg-1.min-1) aerobic fitness. Time-to-fatigue during the SACM was not significantly different between male and female subjects (250 +/- 97 and 246 +/- 149 s, respectively).

  19. Inquiry-based problem solving in introductory physics

    NASA Astrophysics Data System (ADS)

    Koleci, Carolann

    What makes problem solving in physics difficult? How do students solve physics problems, and how does this compare to an expert physicist's strategy? Over the past twenty years, physics education research has revealed several differences between novice and expert problem solving. The work of Chi, Feltovich, and Glaser demonstrates that novices tend to categorize problems based on surface features, while experts categorize according to theory, principles, or concepts1. If there are differences between how problems are categorized, then are there differences between how physics problems are solved? Learning more about the problem solving process, including how students like to learn and what is most effective, requires both qualitative and quantitative analysis. In an effort to learn how novices and experts solve introductory electricity problems, a series of in-depth interviews were conducted, transcribed, and analyzed, using both qualitative and quantitative methods. One-way ANOVA tests were performed in order to learn if there are any significant problem solving differences between: (a) novices and experts, (b) genders, (c) students who like to answer questions in class and those who don't, (d) students who like to ask questions in class and those who don't, (e) students employing an interrogative approach to problem solving and those who don't, and (f) those who like physics and those who dislike it. The results of both the qualitative and quantitative methods reveal that inquiry-based problem solving is prevalent among novices and experts, and frequently leads to the correct physics. These findings serve as impetus for the third dimension of this work: the development of Choose Your Own Adventure Physics(c) (CYOAP), an innovative teaching tool in physics which encourages inquiry-based problem solving. 1Chi, M., P. Feltovich, R. Glaser, "Categorization and Representation of Physics Problems by Experts and Novices", Cognitive Science, 5, 121--152 (1981).

  20. Cosmic Acceleration, Dark Energy, and Fundamental Physics

    NASA Astrophysics Data System (ADS)

    Turner, Michael S.; Huterer, Dragan

    2007-11-01

    A web of interlocking observations has established that the expansion of the Universe is speeding up and not slowing, revealing the presence of some form of repulsive gravity. Within the context of general relativity the cause of cosmic acceleration is a highly elastic ( p˜-ρ), very smooth form of energy called “dark energy” accounting for about 75% of the Universe. The “simplest” explanation for dark energy is the zero-point energy density associated with the quantum vacuum; however, all estimates for its value are many orders-of-magnitude too large. Other ideas for dark energy include a very light scalar field or a tangled network of topological defects. An alternate explanation invokes gravitational physics beyond general relativity. Observations and experiments underway and more precise cosmological measurements and laboratory experiments planned for the next decade will test whether or not dark energy is the quantum energy of the vacuum or something more exotic, and whether or not general relativity can self consistently explain cosmic acceleration. Dark energy is the most conspicuous example of physics beyond the standard model and perhaps the most profound mystery in all of science.

  1. Chemical vs. Physical Acceleration of Cement Hydration

    PubMed Central

    Bentz, Dale P.; Zunino, Franco; Lootens, Didier

    2016-01-01

    Cold weather concreting often requires the use of chemical accelerators to speed up the hydration reactions of the cement, so that setting and early-age strength development will occur in a timely manner. While calcium chloride (dihydrate – CaCl2·2H2O) is the most commonly used chemical accelerator, recent research using fine limestone powders has indicated their high proficiency for physically accelerating early-age hydration and reducing setting times. This paper presents a comparative study of the efficiency of these two approaches in accelerating hydration (as assessed via isothermal calorimetry), reducing setting times (Vicat needle), and increasing early-age mortar cube strength (1 d and 7 d). Both the CaCl2 and the fine limestone powder are used to replace a portion of the finest sand in the mortar mixtures, while keeping both the water-to-cement ratio and volume fractions of water and cement constant. Studies are conducted at 73.4 °F (23°C) and 50 °F (10 °C), so that activation energies can be estimated for the hydration and setting processes. Because the mechanisms of acceleration of the CaCl2 and limestone powder are different, a hybrid mixture with 1 % CaCl2 and 20 % limestone powder (by mass of cement) is also investigated. Both technologies are found to be viable options for reducing setting times and increasing early-age strengths, and it is hoped that concrete producers and contractors will consider the addition of fine limestone powder to their toolbox of techniques for assuring performance in cold weather and other concreting conditions where acceleration may be needed. PMID:28077884

  2. 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,…

  3. Lecture Notes on Topics in Accelerator Physics

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

    Chao, Alex W.

    These are lecture notes that cover a selection of topics, some of them under current research, in accelerator physics. I try to derive the results from first principles, although the students are assumed to have an introductory knowledge of the basics. The topics covered are: (1) Panofsky-Wenzel and Planar Wake Theorems; (2) Echo Effect; (3) Crystalline Beam; (4) Fast Ion Instability; (5) Lawson-Woodward Theorem and Laser Acceleration in Free Space; (6) Spin Dynamics and Siberian Snakes; (7) Symplectic Approximation of Maps; (8) Truncated Power Series Algebra; and (9) Lie Algebra Technique for nonlinear Dynamics. The purpose of these lectures ismore » not to elaborate, but to prepare the students so that they can do their own research. Each topic can be read independently of the others.« less

  4. 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.

  5. 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)

  6. Graduate Student Program in Materials and Engineering Research and Development for Future Accelerators

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

    Spentzouris, Linda

    The objective of the proposal was to develop graduate student training in materials and engineering research relevant to the development of particle accelerators. Many components used in today's accelerators or storage rings are at the limit of performance. The path forward in many cases requires the development of new materials or fabrication techniques, or a novel engineering approach. Often, accelerator-based laboratories find it difficult to get top-level engineers or materials experts with the motivation to work on these problems. The three years of funding provided by this grant was used to support development of accelerator components through a multidisciplinary approachmore » that cut across the disciplinary boundaries of accelerator physics, materials science, and surface chemistry. The following results were achieved: (1) significant scientific results on fabrication of novel photocathodes, (2) application of surface science and superconducting materials expertise to accelerator problems through faculty involvement, (3) development of instrumentation for fabrication and characterization of materials for accelerator components, (4) student involvement with problems at the interface of material science and accelerator physics.« less

  7. Hierarchy problem and BSM physics

    NASA Astrophysics Data System (ADS)

    Bhattacharyya, Gautam

    2017-10-01

    The `hierarchy problem' plagues the Standard Model of particle physics. The source of this problem is our inability to answer the following question: Why is the Higgs mass so much below the GUT or Planck scale? A brief description about how `supersymmetry' and `composite Higgs' address this problem is given here.

  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. Competing explanations for cosmic acceleration or why is the expansion of the universe accelerating?

    NASA Astrophysics Data System (ADS)

    Ishak, Mustapha

    2012-06-01

    For more than a decade, a number of cosmological observations have been indicating that the expansion of the universe is accelerating. Cosmic acceleration and the questions associated with it have become one of the most challenging and puzzling problems in cosmology and physics. Cosmic acceleration can be caused by (i) a repulsive dark energy pervading the universe, (ii) an extension to General Relativity that takes effect at cosmological scales of distance, or (iii) the acceleration may be an apparent effect due to the fact that the expansion rate of space-time is uneven from one region to another in the universe. I will review the basics of these possibilities and provide some recent results including ours on these questions.

  10. 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.

  11. GRIPs (Group Investigation Problems) for Introductory Physics

    NASA Astrophysics Data System (ADS)

    Moore, Thomas A.

    2006-12-01

    GRIPs lie somewhere between homework problems and simple labs: they are open-ended questions that require a mixture of problem-solving skills and hands-on experimentation to solve practical puzzles involving simple physical objects. In this talk, I will describe three GRIPs that I developed for a first-semester introductory calculus-based physics course based on the "Six Ideas That Shaped Physics" text. I will discuss the design of the three GRIPs we used this past fall, our experience in working with students on these problems, and students' response as reported on course evaluations.

  12. The Missing Curriculum in Physics Problem-Solving Education

    NASA Astrophysics Data System (ADS)

    Williams, Mobolaji

    2018-05-01

    Physics is often seen as an excellent introduction to science because it allows students to learn not only the laws governing the world around them, but also, through the problems students solve, a way of thinking which is conducive to solving problems outside of physics and even outside of science. In this article, we contest this latter idea and argue that in physics classes, students do not learn widely applicable problem-solving skills because physics education almost exclusively requires students to solve well-defined problems rather than the less-defined problems which better model problem solving outside of a formal class. Using personal, constructed, and the historical accounts of Schrödinger's development of the wave equation and Feynman's development of path integrals, we argue that what is missing in problem-solving education is practice in identifying gaps in knowledge and in framing these knowledge gaps as questions of the kind answerable using techniques students have learned. We discuss why these elements are typically not taught as part of the problem-solving curriculum and end with suggestions on how to incorporate these missing elements into physics classes.

  13. 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…

  14. Implementation of an accelerated physical examination course in a doctor of pharmacy program.

    PubMed

    Ho, Jackie; Bidwal, Monica K; Lopes, Ingrid C; Shah, Bijal M; Ip, Eric J

    2014-12-15

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

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

    PubMed Central

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

    2014-01-01

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

  16. A physical process of the radial acceleration of disc galaxies

    NASA Astrophysics Data System (ADS)

    Wilhelm, Klaus; Dwivedi, Bhola N.

    2018-03-01

    An impact model of gravity designed to emulate Newton's law of gravitation is applied to the radial acceleration of disc galaxies. Based on this model (Wilhelm et al. 2013), the rotation velocity curves can be understood without the need to postulate any dark matter contribution. The increased acceleration in the plane of the disc is a consequence of multiple interactions of gravitons (called `quadrupoles' in the original paper) and the subsequent propagation in this plane and not in three-dimensional space. The concept provides a physical process that relates the fit parameter of the acceleration scale defined by McGaugh et al. (2016) to the mean free path length of gravitons in the discs of galaxies. It may also explain the gravitational interaction at low acceleration levels in MOdification of the Newtonian Dynamics (MOND, Milgrom 1983, 1994, 2015, 2016). Three examples are discussed in some detail: the spiral galaxies NGC 7814, NGC 6503 and M 33.

  17. 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

  18. Signal of Acceleration and Physical Mechanism of Water Cycle in Xinjiang, China

    PubMed Central

    Feng, Guo-Lin; Wu, Yong-Ping

    2016-01-01

    Global warming accelerates water cycle with features of regional difference. However, little is known about the physical mechanism behind the phenomenon. To reveal the links between water cycle and climatic environment, we analyzed the changes of water cycle elements and their relationships with climatic and environmental factors. We found that when global warming was significant during the period of 1986-2003, the precipitation in Tarim mountains as well as Xinjiang increased rapidly except for Tarim plains, which indicated that there existed a signal of acceleration for water cycle in Xinjiang. The speed of water cycle is mainly affected by altitude, latitude, longitude, slope direction, and the most fundamental element is temperature. Moreover, according to Clausius-Kela Bai Lung relation, we found that the climate change induced the increase of temperature and accelerated the local water cycle only for the wet places. Our results provide a possible physical mechanisms of water cycle and thus well link the climate change to water circulation. PMID:27907078

  19. Signal of Acceleration and Physical Mechanism of Water Cycle in Xinjiang, China.

    PubMed

    Feng, Guo-Lin; Wu, Yong-Ping

    2016-01-01

    Global warming accelerates water cycle with features of regional difference. However, little is known about the physical mechanism behind the phenomenon. To reveal the links between water cycle and climatic environment, we analyzed the changes of water cycle elements and their relationships with climatic and environmental factors. We found that when global warming was significant during the period of 1986-2003, the precipitation in Tarim mountains as well as Xinjiang increased rapidly except for Tarim plains, which indicated that there existed a signal of acceleration for water cycle in Xinjiang. The speed of water cycle is mainly affected by altitude, latitude, longitude, slope direction, and the most fundamental element is temperature. Moreover, according to Clausius-Kela Bai Lung relation, we found that the climate change induced the increase of temperature and accelerated the local water cycle only for the wet places. Our results provide a possible physical mechanisms of water cycle and thus well link the climate change to water circulation.

  20. The Implementation of Physics Problem Solving Strategy Combined with Concept Map in General Physics Course

    NASA Astrophysics Data System (ADS)

    Hidayati, H.; Ramli, R.

    2018-04-01

    This paper aims to provide a description of the implementation of Physic Problem Solving strategy combined with concept maps in General Physics learning at Department of Physics, Universitas Negeri Padang. Action research has been conducted in two cycles where each end of the cycle is reflected and improved for the next cycle. Implementation of Physics Problem Solving strategy combined with concept map can increase student activity in solving general physics problem with an average increase of 15% and can improve student learning outcomes from 42,7 in the cycle I become 62,7 in cycle II in general physics at the Universitas Negeri Padang. In the future, the implementation of Physic Problem Solving strategy combined with concept maps will need to be considered in Physics courses.

  1. Evolutionary optimization methods for accelerator design

    NASA Astrophysics Data System (ADS)

    Poklonskiy, Alexey A.

    Many problems from the fields of accelerator physics and beam theory can be formulated as optimization problems and, as such, solved using optimization methods. Despite growing efficiency of the optimization methods, the adoption of modern optimization techniques in these fields is rather limited. Evolutionary Algorithms (EAs) form a relatively new and actively developed optimization methods family. They possess many attractive features such as: ease of the implementation, modest requirements on the objective function, a good tolerance to noise, robustness, and the ability to perform a global search efficiently. In this work we study the application of EAs to problems from accelerator physics and beam theory. We review the most commonly used methods of unconstrained optimization and describe the GATool, evolutionary algorithm and the software package, used in this work, in detail. Then we use a set of test problems to assess its performance in terms of computational resources, quality of the obtained result, and the tradeoff between them. We justify the choice of GATool as a heuristic method to generate cutoff values for the COSY-GO rigorous global optimization package for the COSY Infinity scientific computing package. We design the model of their mutual interaction and demonstrate that the quality of the result obtained by GATool increases as the information about the search domain is refined, which supports the usefulness of this model. We Giscuss GATool's performance on the problems suffering from static and dynamic noise and study useful strategies of GATool parameter tuning for these and other difficult problems. We review the challenges of constrained optimization with EAs and methods commonly used to overcome them. We describe REPA, a new constrained optimization method based on repairing, in exquisite detail, including the properties of its two repairing techniques: REFIND and REPROPT. We assess REPROPT's performance on the standard constrained

  2. 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

  3. 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

  4. Present and future prospects of accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kutschera, Walter

    1988-05-01

    Accelerator mass spectrometry (AMS) has become a powerful technique for measuring extremely low abundances (10 -10 to 10 -15 relative to stable isotopes) of long-lived radioisotopes with half-lives in the range from 10 2 to 10 8 years. With a few exceptions, tandem accelerators turned out to be the most useful instruments for AMS measurements. Both natural (mostly cosmogenic) and manmade (anthropogenic) radioisotopes are studied with this technique. In some cases very low concentrations of stable isotopes are also measured. Applications of AMS cover a large variety of fields including anthropology, archaeology, oceanography, hydrology, climatology, volcanology, mineral exploration, cosmochemistry, meteoritics, glaciology, sedimentary processes, geochronology, environmental physics, astrophysics, nuclear and particle physics. Present and future prospects of AMS will be discussed as an interplay between the continuous development of new techniques and the investigation of problems in the above mentioned fields. Depending on the specific problem to be investigated, different aspects of an AMS system are of importance. Typical factors to be considered are energy range and type of accelerator, and the possibilities of dedicated versus partial use of new or existing accelerators.

  5. EDITORIAL: Metrological Aspects of Accelerator Technology and High Energy Physics Experiments

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.; Pozniak, Krzysztof T.

    2007-08-01

    The subject of this special feature in Measurement Science and Technology concerns measurement methods, devices and subsystems, both hardware and software aspects, applied in large experiments of high energy physics (HEP) and superconducting RF accelerator technology (SRF). These experiments concern mainly the physics of elementary particles or the building of new machines and detectors. The papers present practical examples of applied solutions in large, contemporary, international research projects such as HERA, LHC, FLASH, XFEL, ILC and others. These machines are unique in their global scale and consist of extremely dedicated apparatus. The apparatus is characterized by very large dimensions, a considerable use of resources and a high level of overall technical complexity. They possess a large number of measurement channels (ranging from thousands to over 100 million), are characterized by fast of processing of measured data and high measurement accuracies, and work in quite adverse environments. The measurement channels cooperate with a large number of different sensors of momenta, energies, trajectories of elementary particles, electron, proton and photon beam profiles, accelerating fields in resonant cavities, and many others. The provision of high quality measurement systems requires the designers to use only the most up-to-date technical solutions, measurement technologies, components and devices. Research work in these demanding fields is a natural birthplace of new measurement methods, new data processing and acquisition algorithms, complex, networked measurement system diagnostics and monitoring. These developments are taking place in both hardware and software layers. The chief intention of this special feature is that the papers represent equally some of the most current metrology research problems in HEP and SRF. The accepted papers have been divided into four topical groups: superconducting cavities (4 papers), low level RF systems (8 papers

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

    NASA Astrophysics Data System (ADS)

    Shiltsev, Vladimir D.

    2015-08-01

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

  7. 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.

  8. Using isomorphic problems to learn introductory physics

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Yin; Singh, Chandralekha

    2011-12-01

    In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. Three hundred sixty-two students from a calculus-based and an algebra-based introductory physics course were given a quiz in the recitation in which they had to first learn from a solved problem provided and take advantage of what they learned from it to solve another problem (which we call the quiz problem) which was isomorphic. Previous research suggests that the multiple-concept quiz problem is challenging for introductory students. Students in different recitation classes received different interventions in order to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. We also conducted think-aloud interviews with four introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. We found that most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem. However, they were not necessarily able to apply the principles correctly. Research suggests that more scaffolding is needed to help students in applying these principles appropriately. We outline a few possible strategies for future investigation.

  9. Examining problem solving in physics-intensive Ph.D. research

    NASA Astrophysics Data System (ADS)

    Leak, Anne E.; Rothwell, Susan L.; Olivera, Javier; Zwickl, Benjamin; Vosburg, Jarrett; Martin, Kelly Norris

    2017-12-01

    Problem-solving strategies learned by physics undergraduates should prepare them for real-world contexts as they transition from students to professionals. Yet, graduate students in physics-intensive research face problems that go beyond problem sets they experienced as undergraduates and are solved by different strategies than are typically learned in undergraduate coursework. This paper expands the notion of problem solving by characterizing the breadth of problems and problem-solving processes carried out by graduate students in physics-intensive research. We conducted semi-structured interviews with ten graduate students to determine the routine, difficult, and important problems they engage in and problem-solving strategies they found useful in their research. A qualitative typological analysis resulted in the creation of a three-dimensional framework: context, activity, and feature (that made the problem challenging). Problem contexts extended beyond theory and mathematics to include interactions with lab equipment, data, software, and people. Important and difficult contexts blended social and technical skills. Routine problem activities were typically well defined (e.g., troubleshooting), while difficult and important ones were more open ended and had multiple solution paths (e.g., evaluating options). In addition to broadening our understanding of problems faced by graduate students, our findings explore problem-solving strategies (e.g., breaking down problems, evaluating options, using test cases or approximations) and characteristics of successful problem solvers (e.g., initiative, persistence, and motivation). Our research provides evidence of the influence that problems students are exposed to have on the strategies they use and learn. Using this evidence, we have developed a preliminary framework for exploring problems from the solver's perspective. This framework will be examined and refined in future work. Understanding problems graduate students

  10. SOME PROBLEMS IN THE CONSTRUCTION OF AN ELECTRON LINEAR ACCELERATOR (in Dutch)

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

    Verhaeghe, J.; Vanhuyse, V.; Van Leuven, P.

    1959-01-01

    Special problems encountered in the construction of the electron linear accelerator of the Natuurkundig Laboratorium der Rijksuniversiteit of Ghent are discussed. The subjects considered are magnetic focusing, magnetic screening of the electron gun cathode, abnormal attenuation-multipactor effects, and electron energy control. (J.S.R.)

  11. Solving the problem of negative populations in approximate accelerated stochastic simulations using the representative reaction approach.

    PubMed

    Kadam, Shantanu; Vanka, Kumar

    2013-02-15

    Methods based on the stochastic formulation of chemical kinetics have the potential to accurately reproduce the dynamical behavior of various biochemical systems of interest. However, the computational expense makes them impractical for the study of real systems. Attempts to render these methods practical have led to the development of accelerated methods, where the reaction numbers are modeled by Poisson random numbers. However, for certain systems, such methods give rise to physically unrealistic negative numbers for species populations. The methods which make use of binomial variables, in place of Poisson random numbers, have since become popular, and have been partially successful in addressing this problem. In this manuscript, the development of two new computational methods, based on the representative reaction approach (RRA), has been discussed. The new methods endeavor to solve the problem of negative numbers, by making use of tools like the stochastic simulation algorithm and the binomial method, in conjunction with the RRA. It is found that these newly developed methods perform better than other binomial methods used for stochastic simulations, in resolving the problem of negative populations. Copyright © 2012 Wiley Periodicals, Inc.

  12. Problem solving in the borderland between mathematics and physics

    NASA Astrophysics Data System (ADS)

    Jensen, Jens Højgaard; Niss, Martin; Jankvist, Uffe Thomas

    2017-01-01

    The article addresses the problématique of where mathematization is taught in the educational system, and who teaches it. Mathematization is usually not a part of mathematics programs at the upper secondary level, but we argue that physics teaching has something to offer in this respect, if it focuses on solving so-called unformalized problems, where a major challenge is to formalize the problems in mathematics and physics terms. We analyse four concrete examples of unformalized problems for which the formalization involves different order of mathematization and applying physics to the problem, but all require mathematization. The analysis leads to the formulation of a model by which we attempt to capture the important steps of the process of solving unformalized problems by means of mathematization and physicalization.

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

    USDA-ARS?s Scientific Manuscript database

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

  14. 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).

  15. Role of Multiple Representations in Physics Problem Solving

    ERIC Educational Resources Information Center

    Maries, Alexandru

    2013-01-01

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

  16. Pulsed power accelerator for material physics experiments

    DOE PAGES

    Reisman, D.  B.; Stoltzfus, B.  S.; Stygar, W.  A.; ...

    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 tomore » 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.« less

  17. Accelerated Physical Stability Testing of Amorphous Dispersions.

    PubMed

    Mehta, Mehak; Suryanarayanan, Raj

    2016-08-01

    The goal was to develop an accelerated physical stability testing method of amorphous dispersions. Water sorption is known to cause plasticization and may accelerate drug crystallization. In an earlier investigation, it was observed that both the increase in mobility and decrease in stability in amorphous dispersions was explained by the "plasticization" effect of water (Mehta et al. Mol. Pharmaceutics 2016, 13 (4), 1339-1346). In this work, the influence of water concentration (up to 1.8% w/w) on the correlation between mobility and crystallization in felodipine dispersions was investigated. With an increase in water content, the α-relaxation time as well as the time for 1% w/w felodipine crystallization decreased. The relaxation times of the systems, obtained with different water concentration, overlapped when the temperature was scaled (Tg/T). The temperature dependencies of the α-relaxation time as well as the crystallization time were unaffected by the water concentration. Thus, the value of the coupling coefficient, up to a water concentration of 1.8% w/w, was approximately constant. Based on these findings, the use of "water sorption" is proposed to build predictive models for crystallization in slow crystallizing dispersions.

  18. Pre-Service Physics Teachers’ Problem-solving Skills in Projectile Motion Concept

    NASA Astrophysics Data System (ADS)

    Sutarno, S.; Setiawan, A.; Kaniawati, I.; Suhandi, A.

    2017-09-01

    This study is a preliminary research aiming at exploring pre-service physics teachers’ skills in applying the stage of problem-solving strategies. A total of 76 students of physics education study program at a college in Bengkulu Indonesia participated in the study. The skills on solving physics problems are being explored through exercises that demand the use of problem-solving strategies with several stages such as useful description, physics approach, specific application of physics, physics equation, mathematical procedures, and logical progression. Based on the results of data analysis, it is found that the pre-service physics teachers’ skills are in the moderate category for physics approach and mathematical procedural, and low category for the others. It was concluded that the pre-service physics teachers’ problem-solving skills are categorized low. It is caused by the learning of physics that has done less to practice problem-solving skills. The problems provided are only routine and poorly trained in the implementation of problem-solving strategies.The results of the research can be used as a reference for the importance of the development of physics learning based on higher order thinking skills.

  19. FERMILAB ACCELERATOR R&D PROGRAM TOWARDS INTENSITY FRONTIER ACCELERATORS : STATUS AND PROGRESS

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

    Shiltsev, Vladimir

    2016-11-15

    The 2014 P5 report indicated the accelerator-based neutrino and rare decay physics research as a centrepiece of the US domestic HEP program at Fermilab. Operation, upgrade and development of the accelerators for the near- term and longer-term particle physics program at the Intensity Frontier face formidable challenges. Here we discuss key elements of the accelerator physics and technology R&D program toward future multi-MW proton accelerators and present its status and progress. INTENSITY FRONTIER ACCELERATORS

  20. Physical health problems in adults with Prader-Willi syndrome.

    PubMed

    Sinnema, Margje; Maaskant, Marian A; van Schrojenstein Lantman-de Valk, Henny M J; van Nieuwpoort, I Caroline; Drent, Madeleine L; Curfs, Leopold M G; Schrander-Stumpel, Constance T R M

    2011-09-01

    Prader-Willi syndrome (PWS) is a genetic disorder which is characterized by severe hypotonia and feeding problems in early infancy. In later childhood and adolescence, this is followed by hyperphagia and extreme obesity if the diet is not strictly controlled. Data on physical health problems in adults with PWS are scarce. We report on the prevalence of physical health problems in a Dutch cohort of adults with PWS in relation to age, BMI, and genetic subtype. Participants (n = 102) were retrieved via the Dutch Prader-Willi Parent Association and through physicians specializing in persons with intellectual disabilities (ID). Details regarding physical health problem spanning the participants' lifespan were collected from caretakers through semi-structured interviews. Cardiovascular problems included diabetes mellitus, hypertension, and cerebrovascular accidents. Respiratory infections were frequent in adulthood. In males, cryptorchidism was almost universal, for which 28/48 males had a history of surgery, mostly orchidopexy. None of the women had a regular menstrual cycle. Sixteen individuals had a diagnosis of osteoporosis. Spinal deformation, hip dysplasia, and foot abnormalities were common. Skinpicking, leg edema, and erysipelas were frequent dermatological problems. The findings in our group support the notion that the prevalence of physical health problems is underestimated. This underscores the importance of developing monitoring programs which would help to recognize physical health problems at an early stage. Copyright © 2011 Wiley-Liss, Inc.

  1. Examining Problem Solving in Physics-Intensive Ph.D. Research

    ERIC Educational Resources Information Center

    Leak, Anne E.; Rothwell, Susan L.; Olivera, Javier; Zwickl, Benjamin; Vosburg, Jarrett; Martin, Kelly Norris

    2017-01-01

    Problem-solving strategies learned by physics undergraduates should prepare them for real-world contexts as they transition from students to professionals. Yet, graduate students in physics-intensive research face problems that go beyond problem sets they experienced as undergraduates and are solved by different strategies than are typically…

  2. 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…

  3. Impact accelerations

    NASA Technical Reports Server (NTRS)

    Vongierke, H. E.; Brinkley, J. W.

    1975-01-01

    The degree to which impact acceleration is an important factor in space flight environments depends primarily upon the technology of capsule landing deceleration and the weight permissible for the associated hardware: parachutes or deceleration rockets, inflatable air bags, or other impact attenuation systems. The problem most specific to space medicine is the potential change of impact tolerance due to reduced bone mass and muscle strength caused by prolonged weightlessness and physical inactivity. Impact hazards, tolerance limits, and human impact tolerance related to space missions are described.

  4. 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

  5. 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.

  6. 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

  7. Vecksler-Macmillan phase stability for neutral atoms accelerated by a laser beam

    NASA Astrophysics Data System (ADS)

    Mel'nikov, I. V.; Haus, J. W.; Kazansky, P. G.

    2003-05-01

    We use a Fokker-Planck equation to study the phenomenon of accelerating a neutral atom bunch by a chirped optical beam. This method enables us to obtain a semi-analytical solution to the problem in which a wide range of parameters can be studied. In addition it provides a simple physical interpretation where the problem is reduced to an analogous problem of charged particles accelerators, that is, the Vecksler-Macmillan principle of phase stability. A possible experimental scenario is suggested, which uses a photonic crystal fiber as the guiding medium.

  8. Physical Scaffolding Accelerates the Evolution of Robot Behavior.

    PubMed

    Buckingham, David; Bongard, Josh

    2017-01-01

    In some evolutionary robotics experiments, evolved robots are transferred from simulation to reality, while sensor/motor data flows back from reality to improve the next transferral. We envision a generalization of this approach: a simulation-to-reality pipeline. In this pipeline, increasingly embodied agents flow up through a sequence of increasingly physically realistic simulators, while data flows back down to improve the next transferral between neighboring simulators; physical reality is the last link in this chain. As a first proof of concept, we introduce a two-link chain: A fast yet low-fidelity ( lo-fi) simulator hosts minimally embodied agents, which gradually evolve controllers and morphologies to colonize a slow yet high-fidelity ( hi-fi) simulator. The agents are thus physically scaffolded. We show here that, given the same computational budget, these physically scaffolded robots reach higher performance in the hi-fi simulator than do robots that only evolve in the hi-fi simulator, but only for a sufficiently difficult task. These results suggest that a simulation-to-reality pipeline may strike a good balance between accelerating evolution in simulation while anchoring the results in reality, free the investigator from having to prespecify the robot's morphology, and pave the way to scalable, automated, robot-generating systems.

  9. Ultrahigh Energy Cosmic Rays: Old Physics or New Physics?

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.

    2004-01-01

    We consider the advantages of and the problems associated with hypotheses to explain the origin of ultrahigh energy cosmic rays (UHECR: E greater than 10 EeV) and the "trans-GZK" cosmic rays (TGZK: E greater than 100 EeV) both through "old physics" (acceleration in cosmic sources) and "new physics" (new particles, topological defects, fat neutrino cross sections, Lorentz invariance violation).

  10. Physical activity problem-solving inventory for adolescents: development and initial validation.

    PubMed

    Thompson, Debbe; Bhatt, Riddhi; Watson, Kathy

    2013-08-01

    Youth encounter physical activity barriers, often called problems. The purpose of problem solving is to generate solutions to overcome the barriers. Enhancing problem-solving ability may enable youth to be more physically active. Therefore, a method for reliably assessing physical activity problem-solving ability is needed. The purpose of this research was to report the development and initial validation of the physical activity problem-solving inventory for adolescents (PAPSIA). Qualitative and quantitative procedures were used. The social problem-solving inventory for adolescents guided the development of the PAPSIA scale. Youth (14- to 17-year-olds) were recruited using standard procedures, such as distributing flyers in the community and to organizations likely to be attended by adolescents. Cognitive interviews were conducted in person. Adolescents completed pen and paper versions of the questionnaire and/or scales assessing social desirability, self-reported physical activity, and physical activity self-efficacy. An expert panel review, cognitive interviews, and a pilot study (n = 129) established content validity. Construct, concurrent, and predictive validity were also established (n = 520 youth). PAPSIA is a promising measure for assessing youth physical activity problem-solving ability. Future research will assess its validity with objectively measured physical activity.

  11. 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.

  12. The Effect of Problem Based Learning (PBL) Instruction on Students' Motivation and Problem Solving Skills of Physics

    ERIC Educational Resources Information Center

    Argaw, Aweke Shishigu; Haile, Beyene Bashu; Ayalew, Beyene Tesfaw; Kuma, Shiferaw Gadisa

    2017-01-01

    Through the learning of physics, students will acquire problem solving skills which are relevant to their daily life. Determining the best way in which students learn physics takes a priority in physics education. The goal of the present study was to determine the effect of problem based learning strategy on students' problem solving skills and…

  13. 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

  14. 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.

  15. Using an isomorphic problem pair to learn introductory physics: Transferring from a two-step problem to a three-step problem

    NASA Astrophysics Data System (ADS)

    Lin, Shih-Yin; Singh, Chandralekha

    2013-12-01

    In this study, we examine introductory physics students’ ability to perform analogical reasoning between two isomorphic problems which employ the same underlying physics principles but have different surface features. 382 students from a calculus-based and an algebra-based introductory physics course were administered a quiz in the recitation in which they had to learn from a solved problem provided and take advantage of what they learned from it to solve another isomorphic problem (which we call the quiz problem). The solved problem provided has two subproblems while the quiz problem has three subproblems, which is known from previous research to be challenging for introductory students. In addition to the solved problem, students also received extra scaffolding supports that were intended to help them discern and exploit the underlying similarities of the isomorphic solved and quiz problems. The data analysis suggests that students had great difficulty in transferring what they learned from a two-step problem to a three-step problem. Although most students were able to learn from the solved problem to some extent with the scaffolding provided and invoke the relevant principles in the quiz problem, they were not necessarily able to apply the principles correctly. We also conducted think-aloud interviews with six introductory students in order to understand in depth the difficulties they had and explore strategies to provide better scaffolding. The interviews suggest that students often superficially mapped the principles employed in the solved problem to the quiz problem without necessarily understanding the governing conditions underlying each principle and examining the applicability of the principle in the new situation in an in-depth manner. Findings suggest that more scaffolding is needed to help students in transferring from a two-step problem to a three-step problem and applying the physics principles appropriately. We outline a few possible strategies

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

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

    Rivlin, Lev A

    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)

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

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

    Chauvin, J. P.; Lebrat, J. F.; Soule, R.

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

  18. 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.

  19. Open problems in mathematical physics

    NASA Astrophysics Data System (ADS)

    Coley, Alan A.

    2017-09-01

    We present a list of open questions in mathematical physics. After a historical introduction, a number of problems in a variety of different fields are discussed, with the intention of giving an overall impression of the current status of mathematical physics, particularly in the topical fields of classical general relativity, cosmology and the quantum realm. This list is motivated by the recent article proposing 42 fundamental questions (in physics) which must be answered on the road to full enlightenment (Allen and Lidstrom 2017 Phys. Scr. 92 012501). But paraphrasing a famous quote by the British football manager Bill Shankly, in response to the question of whether mathematics can answer the Ultimate Question of Life, the Universe, and Everything, mathematics is, of course, much more important than that.

  20. 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…

  1. 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.

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

    NASA Astrophysics Data System (ADS)

    Zhao, Jin-Hua; Zhou, Hai-Jun

    2014-07-01

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

  3. 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…

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

  5. Problem Solving in Physics: Undergraduates' Framing, Procedures, and Decision Making

    NASA Astrophysics Data System (ADS)

    Modir, Bahar

    In this dissertation I will start with the broad research question of what does problem solving in upper division physics look like? My focus in this study is on students' problem solving in physics theory courses. Some mathematical formalisms are common across all physics core courses such as using the process of separation of variables, doing Taylor series, or using the orthogonality properties of mathematical functions to set terms equal to zero. However, there are slight differences in their use of these mathematical formalisms across different courses, possibly because of how students map different physical systems to these processes. Thus, my first main research question aims to answer how students perform these recurring processes across upper division physics courses. I break this broad question into three particular research questions: What knowledge pieces do students use to make connections between physics and procedural math? How do students use their knowledge pieces coherently to provide reasoning strategies in estimation problems? How do students look ahead into the problem to read the information out of the physical scenario to align their use of math in physics? Building on the previous body of the literature, I will use the theory family of Knowledge in Pieces and provide evidence to expand this theoretical foundation. I will compare my study with previous studies and provide suggestions on how to generalize these theory expansions for future use. My experimental data mostly come from video-based classroom data. Students in groups of 2-4 students solve in-class problems in quantum mechanics and electromagnetic fields 1 courses collaboratively. In addition, I will analyze clinical interviews to demonstrate how a single case study student plays an epistemic game to estimate the total energy in a hurricane. My second research question is more focused on a particular instructional context. How do students frame problem solving in quantum mechanics? I

  6. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. 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.

  8. Physics of the saturation of particle acceleration in relativistic magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Kagan, Daniel; Nakar, Ehud; Piran, Tsvi

    2018-05-01

    We investigate the saturation of particle acceleration in relativistic reconnection using two-dimensional particle-in-cell simulations at various magnetizations σ. We find that the particle energy spectrum produced in reconnection quickly saturates as a hard power law that cuts off at γ ≈ 4σ, confirming previous work. Using particle tracing, we find that particle acceleration by the reconnection electric field in X-points determines the shape of the particle energy spectrum. By analysing the current sheet structure, we show that physical cause of saturation is the spontaneous formation of secondary magnetic islands that can disrupt particle acceleration. By comparing the size of acceleration regions to the typical distance between disruptive islands, we show that the maximum Lorentz factor produced in reconnection is γ ≈ 5σ, which is very close to what we find in our particle energy spectra. We also show that the dynamic range in Lorentz factor of the power-law spectrum in reconnection is ≤40. The hardness of the power law combined with its narrow dynamic range implies that relativistic reconnection is capable of producing the hard narrow-band flares observed in the Crab nebula but has difficulty producing the softer broad-band prompt gamma-ray burst emission.

  9. 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.

  10. 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

  11. 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)

  12. 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…

  13. 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,…

  14. 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…

  15. 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

  16. Behaviour of mathematics and physics students in solving problem of Vector-Physics context

    NASA Astrophysics Data System (ADS)

    Sardi; Rizal, M.; Mansyur, J.

    2018-04-01

    This research aimed to describe behaviors of mathematics and physics students in solving problem of the vector concept in physics context. The subjects of the research were students who enrolled in Mathematics Education Study Program and Physics Education Study Program of FKIP Universitas Tadulako. The selected participants were students who received the highest score in vector fundamental concept test in each study program. The data were collected through thinking-aloud activity followed by an interview. The steps of data analysis included data reduction, display, and conclusion drawing. The credibility of the data was tested using a triangulation method. Based on the data analysis, it can be concluded that the two groups of students did not show fundamental differences in problem-solving behavior, especially in the steps of understanding the problem (identifying, collecting and analyzing facts and information), planning (looking for alternative strategies) and conducting the alternative strategy. The two groups were differ only in the evaluation aspect. In contrast to Physics students who evaluated their answer, mathematics students did not conducted an evaluation activity on their work. However, the difference was not caused by the differences in background knowledge.

  17. Commnity Petascale Project for Accelerator Science And Simulation: Advancing Computational Science for Future Accelerators And Accelerator Technologies

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

    Spentzouris, Panagiotis; /Fermilab; Cary, John

    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 necessarymore » 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.« less

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

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

    Gillich, Don; Kovanen, Andrew; Anderson, Tom

    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 {approx}100 keV. Within the next year, cadets and faculty atmore » 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.« less

  19. 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.

  20. Spatial visualization in physics problem solving.

    PubMed

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

    2007-07-08

    Three studies were conducted to examine the relation of spatial visualization to solving kinematics problems that involved either predicting the two-dimensional motion of an object, translating from one frame of reference to another, or interpreting kinematics graphs. In Study 1, 60 physics-naíve students were administered kinematics problems and spatial visualization ability tests. In Study 2, 17 (8 high- and 9 low-spatial ability) additional students completed think-aloud protocols while they solved the kinematics problems. In Study 3, the eye movements of fifteen (9 high- and 6 low-spatial ability) students were recorded while the students solved kinematics problems. In contrast to high-spatial students, most low-spatial students did not combine two motion vectors, were unable to switch frames of reference, and tended to interpret graphs literally. The results of the study suggest an important relationship between spatial visualization ability and solving kinematics problems with multiple spatial parameters. 2007 Cognitive Science Society, Inc.

  1. 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…

  2. Self-Paced Physics, Segments 11-14.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    Four segments of the Self-Paced Physics Course materials are presented in this problems and solutions book for use as the third part of student course work. The subject-matter topics are related to impulses, inelastic and elastic collisions, two-dimensional collision problems, universal constant of gravitation, gravitational acceleration and…

  3. Physics through the 1990s: Elementary-particle physics

    NASA Astrophysics Data System (ADS)

    The volume begins with a non-mathematical discussion of the motivation behind, and basic ideas of, elementary-particle physics theory and experiment. The progress over the past two decades with the quark model and unification of the electromagnetic and weak interactions is reviewed. Existing theoretical problems in the field, such as the origin of mass and the unification of the fundamental forces, are detailed, along with experimental programs to test the new theories. Accelerators, instrumentation, and detectors are described for both current and future facilities. Interactions with other areas of both theoretical and applied physics are presented. The sociology of the field is examined regarding the education of graduate students, the organization necessary in large-scale experiments, and the decision-making process involved in high-cost experiments. Finally, conclusions and recommendations for maintaining US excellence in theory and experiment are given. Appendices list both current and planned accelerators, and present statistical data on the US elementary-particle physics program. A glossary is included.

  4. Physics through the 1990s: Elementary-particle physics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The volume begins with a non-mathematical discussion of the motivation behind, and basic ideas of, elementary-particle physics theory and experiment. The progress over the past two decades with the quark model and unification of the electromagnetic and weak interactions is reviewed. Existing theoretical problems in the field, such as the origin of mass and the unification of the fundamental forces, are detailed, along with experimental programs to test the new theories. Accelerators, instrumentation, and detectors are described for both current and future facilities. Interactions with other areas of both theoretical and applied physics are presented. The sociology of the field is examined regarding the education of graduate students, the organization necessary in large-scale experiments, and the decision-making process involved in high-cost experiments. Finally, conclusions and recommendations for maintaining US excellence in theory and experiment are given. Appendices list both current and planned accelerators, and present statistical data on the US elementary-particle physics program. A glossary is included.

  5. 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.

  6. Victimization, Smoking, and Chronic Physical Health Problems Among Sexual Minority Women

    PubMed Central

    Simoni, Jane M.

    2014-01-01

    Background Sexual minority women (SMW) have been shown to be at increased risk for abuse, smoking, and chronic physical health problems compared with heterosexual women. In the general population, abuse and smoking are associated with physical health problems. However, there has been little research on their associations among SMW. Purpose The current study examined a mediational model of abuse, smoking, and self-reported physical health conditions in a national sample of SMW. Methods Participants (N=1,224) were recruited via the Internet and completed measures of childhood trauma, adult sexual assault, smoking, body mass index, and chronic medical conditions. Results Structural equation modeling demonstrated that childhood abuse was associated with adult sexual assault, smoking, and physical health problems, but smoking was not a significant mediator. Conclusions The results highlight the impact of childhood abuse on physical health problems among SMW and the need to examine other health behaviors that may mediate this relation. PMID:21735343

  7. Chaotic dynamics in accelerator physics

    NASA Astrophysics Data System (ADS)

    Cary, J. R.

    1992-11-01

    Substantial progress was made in several areas of accelerator dynamics. We have completed a design of an FEL wiggler with adiabatic trapping and detrapping sections to develop an understanding of longitudinal adiabatic dynamics and to create efficiency enhancements for recirculating free-electron lasers. We developed a computer code for analyzing the critical KAM tori that binds the dynamic aperture in circular machines. Studies of modes that arise due to the interaction of coating beams with a narrow-spectrum impedance have begun. During this research educational and research ties with the accelerator community at large have been strengthened.

  8. Childhood Physical Punishment and Problem Solving in Marriage

    ERIC Educational Resources Information Center

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

    2006-01-01

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

  9. 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.

  10. Geometric multigrid to accelerate the solution of the quasi-static electric field problem by tetrahedral finite elements.

    PubMed

    Hollaus, K; Weiss, B; Magele, Ch; Hutten, H

    2004-02-01

    The acceleration of the solution of the quasi-static electric field problem considering anisotropic complex conductivity simulated by tetrahedral finite elements of first order is investigated by geometric multigrid.

  11. First muon acceleration using a radio-frequency accelerator

    NASA Astrophysics Data System (ADS)

    Bae, S.; Choi, H.; Choi, S.; Fukao, Y.; Futatsukawa, K.; Hasegawa, K.; Iijima, T.; Iinuma, H.; Ishida, K.; Kawamura, N.; Kim, B.; Kitamura, R.; Ko, H. S.; Kondo, Y.; Li, S.; Mibe, T.; Miyake, Y.; Morishita, T.; Nakazawa, Y.; Otani, M.; Razuvaev, G. P.; Saito, N.; Shimomura, K.; Sue, Y.; Won, E.; Yamazaki, T.

    2018-05-01

    Muons have been accelerated by using a radio-frequency accelerator for the first time. Negative muonium atoms (Mu- ), which are bound states of positive muons (μ+) and two electrons, are generated from μ+'s through the electron capture process in an aluminum degrader. The generated Mu- 's are initially electrostatically accelerated and injected into a radio-frequency quadrupole linac (RFQ). In the RFQ, the Mu- 's are accelerated to 89 keV. The accelerated Mu- 's are identified by momentum measurement and time of flight. This compact muon linac opens the door to various muon accelerator applications including particle physics measurements and the construction of a transmission muon microscope.

  12. 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.

  13. Physics and engineering design of the accelerator and electron dump for SPIDER

    NASA Astrophysics Data System (ADS)

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

    2011-06-01

    The ITER Neutral Beam Test Facility (PRIMA) is planned to be built at Consorzio RFX (Padova, Italy). PRIMA includes two experimental devices: a full size ion source with low voltage extraction called SPIDER and a full size neutral beam injector at full beam power called MITICA. SPIDER is the first experimental device to be built and operated, aiming at testing the extraction of a negative ion beam (made of H- and in a later stage D- ions) from an ITER size ion source. The main requirements of this experiment are a H-/D- extracted current density larger than 355/285 A m-2, an energy of 100 keV and a pulse duration of up to 3600 s. Several analytical and numerical codes have been used for the design optimization process, some of which are commercial codes, while some others were developed ad hoc. The codes are used to simulate the electrical fields (SLACCAD, BYPO, OPERA), the magnetic fields (OPERA, ANSYS, COMSOL, PERMAG), the beam aiming (OPERA, IRES), the pressure inside the accelerator (CONDUCT, STRIP), the stripping reactions and transmitted/dumped power (EAMCC), the operating temperature, stress and deformations (ALIGN, ANSYS) and the heat loads on the electron dump (ED) (EDAC, BACKSCAT). An integrated approach, taking into consideration at the same time physics and engineering aspects, has been adopted all along the design process. Particular care has been taken in investigating the many interactions between physics and engineering aspects of the experiment. According to the 'robust design' philosophy, a comprehensive set of sensitivity analyses was performed, in order to investigate the influence of the design choices on the most relevant operating parameters. The design of the SPIDER accelerator, here described, has been developed in order to satisfy with reasonable margin all the requirements given by ITER, from the physics and engineering points of view. In particular, a new approach to the compensation of unwanted beam deflections inside the accelerator

  14. 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)

  15. IOTA (Integrable Optics Test Accelerator): Facility and experimental beam physics program

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

    Antipov, Sergei; Broemmelsiek, Daniel; Bruhwiler, David

    The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning andmore » research. Finally, the physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.« less

  16. IOTA (Integrable Optics Test Accelerator): Facility and experimental beam physics program

    DOE PAGES

    Antipov, Sergei; Broemmelsiek, Daniel; Bruhwiler, David; ...

    2017-03-06

    The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning andmore » research. Finally, the physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.« less

  17. IOTA (Integrable Optics Test Accelerator): facility and experimental beam physics program

    NASA Astrophysics Data System (ADS)

    Antipov, S.; Broemmelsiek, D.; Bruhwiler, D.; Edstrom, D.; Harms, E.; Lebedev, V.; Leibfritz, J.; Nagaitsev, S.; Park, C. S.; Piekarz, H.; Piot, P.; Prebys, E.; Romanov, A.; Ruan, J.; Sen, T.; Stancari, G.; Thangaraj, C.; Thurman-Keup, R.; Valishev, A.; Shiltsev, V.

    2017-03-01

    The Integrable Optics Test Accelerator (IOTA) is a storage ring for advanced beam physics research currently being built and commissioned at Fermilab. It will operate with protons and electrons using injectors with momenta of 70 and 150 MeV/c, respectively. The research program includes the study of nonlinear focusing integrable optical beam lattices based on special magnets and electron lenses, beam dynamics of space-charge effects and their compensation, optical stochastic cooling, and several other experiments. In this article, we present the design and main parameters of the facility, outline progress to date and provide the timeline of the construction, commissioning and research. The physical principles, design, and hardware implementation plans for the major IOTA experiments are also discussed.

  18. Conceptual design of a pulsed-power accelerator optimized for megajoule-class 1-TPa dynamic-material-physics experiments

    DOE PAGES

    Stygar, William A.; Reisman, David B.; Stoltzfus, Brian S.; ...

    2016-07-07

    In this study, we have developed a conceptual design of a next-generation pulsed-power accelerator that is optmized for driving megajoule-class dynamic-material-physics experiments at pressures as high as 1 TPa. The design is based on an accelerator architecture that is founded on three concepts: single-stage electrical-pulse compression, impedance matching, and transit-time-isolated drive circuits. Since much of the accelerator is water insulated, we refer to this machine as Neptune. The prime power source of Neptune consists of 600 independent impedance-matched Marx generators. As much as 0.8 MJ and 20 MA can be delivered in a 300-ns pulse to a 16-mΩ physics load;more » hence Neptune is a megajoule-class 20-MA arbitrary waveform generator. Neptune will allow the international scientific community to conduct dynamic equation-of-state, phase-transition, mechanical-property, and other material-physics experiments with a wide variety of well-defined drive-pressure time histories. Because Neptune can deliver on the order of a megajoule to a load, such experiments can be conducted on centimeter-scale samples at terapascal pressures with time histories as long as 1 μs.« less

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

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

    Stygar, W. A.; Awe, T. J.; Bennett, N L

    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

  20. 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; ...

    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

  1. 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.

  2. Helping Students with Problems: What Physical Educators Can Do.

    ERIC Educational Resources Information Center

    Jones, C. J.; Nelson, Barbara

    1985-01-01

    Children often have trouble finding effective ways to deal with daily stress. Physical educators work in an environment where they can observe and study their students. Suggestions are offered for physical education teachers dealing with students with problems. (DF)

  3. Nonlinear theory of diffusive acceleration of particles by shock waves

    NASA Astrophysics Data System (ADS)

    Malkov, M. A.; Drury, L. O'C.

    2001-04-01

    Among the various acceleration mechanisms which have been suggested as responsible for the nonthermal particle spectra and associated radiation observed in many astrophysical and space physics environments, diffusive shock acceleration appears to be the most successful. We review the current theoretical understanding of this process, from the basic ideas of how a shock energizes a few reactionless particles to the advanced nonlinear approaches treating the shock and accelerated particles as a symbiotic self-organizing system. By means of direct solution of the nonlinear problem we set the limit to the test-particle approximation and demonstrate the fundamental role of nonlinearity in shocks of astrophysical size and lifetime. We study the bifurcation of this system, proceeding from the hydrodynamic to kinetic description under a realistic condition of Bohm diffusivity. We emphasize the importance of collective plasma phenomena for the global flow structure and acceleration efficiency by considering the injection process, an initial stage of acceleration and, the related aspects of the physics of collisionless shocks. We calculate the injection rate for different shock parameters and different species. This, together with differential acceleration resulting from nonlinear large-scale modification, determines the chemical composition of accelerated particles. The review concentrates on theoretical and analytical aspects but our strategic goal is to link the fundamental theoretical ideas with the rapidly growing wealth of observational data.

  4. Physics and Novel Schemes of Laser Radiation Pressure Acceleration for Quasi-monoenergetic Proton Generation

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

    Liu, Chuan S.; Shao, Xi

    2016-06-14

    The main objective of our work is to provide theoretical basis and modeling support for the design and experimental setup of compact laser proton accelerator to produce high quality proton beams tunable with energy from 50 to 250 MeV using short pulse sub-petawatt laser. We performed theoretical and computational studies of energy scaling and Raleigh--Taylor instability development in laser radiation pressure acceleration (RPA) and developed novel RPA-based schemes to remedy/suppress instabilities for high-quality quasimonoenergetic proton beam generation as we proposed. During the project period, we published nine peer-reviewed journal papers and made twenty conference presentations including six invited talks onmore » our work. The project supported one graduate student who received his PhD degree in physics in 2013 and supported two post-doctoral associates. We also mentored three high school students and one undergraduate student of physics major by inspiring their interests and having them involved in the project.« less

  5. Flare physics at high energies

    NASA Technical Reports Server (NTRS)

    Ramaty, R.

    1990-01-01

    High-energy processes, involving a rich variety of accelerated particle phenomena, lie at the core of the solar flare problem. The most direct manifestation of these processes are high-energy radiations, gamma rays, hard X-rays and neutrons, as well as the accelerated particles themselves, which can be detected in interplanetary space. In the study of astrophysics from the moon, the understanding of these processes should have great importance. The inner solar system environment is strongly influenced by activity on the sun; the physics of solar flares is of great intrinsic interest; and much high-energy astrophysics can be learned from investigations of flare physics at high energies.

  6. Do students benefit from drawing productive diagrams themselves while solving introductory physics problems? The case of two electrostatics problems

    NASA Astrophysics Data System (ADS)

    Maries, Alexandru; Singh, Chandralekha

    2018-01-01

    An appropriate diagram is a required element of a solution building process in physics problem solving and it can transform a given problem into a representation that is easier to exploit for solving the problem. A major focus while helping introductory physics students learn problem solving is to help them appreciate that drawing diagrams facilitates problem solving. We conducted an investigation in which two different interventions were implemented during recitation quizzes throughout the semester in a large enrolment, algebra-based introductory physics course. Students were either (1) asked to solve problems in which the diagrams were drawn for them or (2) explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed a rubric to score the problem solving performance of students in different intervention groups. We investigated two problems involving electric field and electric force and found that students who drew productive diagrams were more successful problem solvers and that a higher level of relevant detail in a student’s diagram corresponded to a better score. We also conducted think-aloud interviews with nine students who were at the time taking an equivalent introductory algebra-based physics course in order to gain insight into how drawing diagrams affects the problem solving process. These interviews supported some of the interpretations of the quantitative results. We end by discussing instructional implications of the findings.

  7. Understanding Coreference in a System for Solving Physics Word Problems.

    NASA Astrophysics Data System (ADS)

    Bulko, William Charles

    In this thesis, a computer program (BEATRIX) is presented which takes as input an English statement of a physics problem and a figure associated with it, understands the two kinds of input in combination, and produces a data structure containing a model of the physical objects described and the relationships between them. BEATRIX provides a mouse-based graphic interface with which the user sketches a picture and enters English sentences; meanwhile, BEATRIX creates a neutral internal representation of the picture similar to the which might be produced as the output of a vision system. It then parses the text and the picture representation, resolves the references between objects common to the two data sources, and produces a unified model of the problem world. The correctness and completeness of this model has been validated by applying it as input to a physics problem-solving program currently under development. Two descriptions of a world are said to be coreferent when they contain references to overlapping sets of objects. Resolving coreferences to produce a correct world model is a common task in scientific and industrial problem-solving: because English is typically not a good language for expressing spatial relationships, people in these fields frequently use diagrams to supplement textual descriptions. Elementary physics problems from college-level textbooks provide a useful and convenient domain for exploring the mechanisms of coreference. Because flexible, opportunistic control is necessary in order to recognize coreference and to act upon it, the understanding module of BEATRIX uses a blackboard control structure. The blackboard knowledge sources serve to identify physical objects in the picture, parse the English text, and resolve coreferences between the two. We believed that BEATRIX demonstrates a control structure and collection of knowledge that successfully implements understanding of text and picture by computer. We also believe that this

  8. Systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators

    DOEpatents

    Grisham, Larry R

    2013-12-17

    The present invention provides systems and methods for the magnetic insulation of accelerator electrodes in electrostatic accelerators. Advantageously, the systems and methods of the present invention improve the practically obtainable performance of these electrostatic accelerators by addressing, among other things, voltage holding problems and conditioning issues. The problems and issues are addressed by flowing electric currents along these accelerator electrodes to produce magnetic fields that envelope the accelerator electrodes and their support structures, so as to prevent very low energy electrons from leaving the surfaces of the accelerator electrodes and subsequently picking up energy from the surrounding electric field. In various applications, this magnetic insulation must only produce modest gains in voltage holding capability to represent a significant achievement.

  9. 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

  10. Radiobiological research at JINR's accelerators

    NASA Astrophysics Data System (ADS)

    Krasavin, E. A.

    2016-04-01

    The half-a-century development of radiobiological studies at the Joint Institute for Nuclear Research (JINR) is reviewed on a stage-by-stage basis. With the use of the institute's accelerators, some key aspects of radiation biology have been settled, including the relative biological effectiveness (RBE) of various types of ionizing radiation with different physical characteristics; radiation-induced mutagenesis mechanisms, and the formation and repair of genetic structure damage. Practical space radiobiology problems that can be solved using high-energy charged particles are discussed.

  11. 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…

  12. Assessing students' ability to solve introductory physics problems using integrals in symbolic and graphical representations

    NASA Astrophysics Data System (ADS)

    Khan, Neelam; Hu, Dehui; Nguyen, Dong-Hai; Rebello, N. Sanjay

    2012-02-01

    Integration is widely used in physics in electricity and magnetism (E&M), as well as in mechanics, to calculate physical quantities from other non-constant quantities. We designed a survey to assess students' ability to apply integration to physics problems in introductory physics. Each student was given a set of eight problems, and each set of problems had two different versions; one consisted of symbolic problems and the other graphical problems. The purpose of this study was to investigate students' strategies for solving physics problems that use integrals in first and second-semester calculus-based physics. Our results indicate that most students had difficulty even recognizing that an integral is needed to solve the problem.

  13. Acceleration training for improving physical fitness and weight loss in obese women.

    PubMed

    So, Rina; Eto, Miki; Tsujimoto, Takehiko; Tanaka, Kiyoji

    2014-01-01

    Reducing body weight and visceral adipose tissue (VAT) are the primary goals for maintaining health in obese individuals as compared to those of normal weight, but it is also important to maintain physical fitness for a healthy life after weight-loss. Acceleration training (AT) has recently been indicated as an alternative to resistance training for elite athletes and also as a component of preventive medicine. However, it is unclear whether combining AT with a weight-loss diet will improve physical fitness in obese individuals. The present study aimed to determine the synergistic effects of AT on body composition and physical fitness with weight-loss program in overweight and obese women. Twenty-eight obese, middle-aged women were divided into two groups as follows: diet and aerobic exercise group (DA; BMI: 29.3 ± 3.0 kg/m2); and diet, aerobic exercise and acceleration training group (DAA; BMI: 31.2 ± 4.0 kg/m2). Both groups included a 12-week weight-loss program. Body composition, visceral adipose tissue (VAT) area and physical fitness (hand grip, side-to-side steps, single-leg balance with eyes closed, sit-and-reach and maximal oxygen uptake) were measured before and after the program. Body weight, BMI, waist circumference and VAT area decreased significantly in both groups. Hand grip (2.1 ± 3.0 kg), single-leg balance (11.0 ± 15.4 s) and sit-and-reach (6.5 ± 4.8 cm) improved significantly only in the DAA group. Our findings indicate that combining AT with classical lifestyle modifications is effective at reducing VAT, and it may enhance muscle strength and performance in overweight and obese women. © 2014 Asian Oceanian Association for the Study of Obesity . Published by Elsevier Ltd. All rights reserved.

  14. 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…

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

    NASA Astrophysics Data System (ADS)

    Folan, Lorcan M.; Tsifrinovich, Vladimir I.

    2007-03-01

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

  16. Physics-based Inverse Problem to Deduce Marine Atmospheric Boundary Layer Parameters

    DTIC Science & Technology

    2017-03-07

    please find the Final Technical Report with SF 298 for Dr. Erin E. Hackett’s ONR grant entitled Physics-based Inverse Problem to Deduce Marine...From- To) 07/03/2017 Final Technica l Dec 2012- Dec 2016 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER Physics-based Inverse Problem to Deduce Marine...SUPPLEMENTARY NOTES 14. ABSTRACT This report describes research results related to the development and implementation of an inverse problem approach for

  17. 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.

  18. Differences in Visual Attention between Those Who Correctly and Incorrectly Answer Physics Problems

    ERIC Educational Resources Information Center

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

    2012-01-01

    This study investigated how visual attention differed between those who correctly versus incorrectly answered introductory physics problems. We recorded eye movements of 24 individuals on six different conceptual physics problems where the necessary information to solve the problem was contained in a diagram. The problems also contained areas…

  19. Research Projects in Physics: A Mechanism for Teaching Ill-Structured Problem Solving

    ERIC Educational Resources Information Center

    Milbourne, Jeff; Bennett, Jonathan

    2017-01-01

    Physics education research has a tradition of studying problem solving, exploring themes such as physical intuition and differences between expert and novice problem solvers. However, most of this work has focused on traditional, or well-structured, problems, similar to what might appear in a textbook. Less work has been done with open-ended, or…

  20. Physics through the 1990s: elementary-particle physics

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

    Not Available

    1986-01-01

    The volume begins with a non-mathematical discussion of the motivation behind, and basic ideas of, elementary-particle physics theory and experiment. The progress over the past two decades with the quark model and unification of the electromagnetic and weak interactions is reviewed. Existing theoretical problems in the field, such as the origin of mass and the unification of the fundamental forces, are detailed, along with experimental programs to test the new theories. Accelerators, instrumentation, and detectors are described for both current and future facilities. Interactions with other areas of both theoretical and applied physics are presented. The sociology of the fieldmore » is examined regarding the education of graduate students, the organization necessary in large-scale experiments, and the decision-making process involved in high-cost experiments. Finally, conclusions and recommendations for maintaining US excellence in theory and experiment are given. Appendices list both current and planned accelerators, and present statistical data on the US elementary-particle physics program. A glossary is included.« less

  1. The physical and chemical stability of anti-tuberculosis fixed-dose combination products under accelerated climatic conditions.

    PubMed

    Bhutani, H; Mariappan, T T; Singh, S

    2004-09-01

    To determine the physical and chemical stability of anti-tuberculosis fixed-dose combinations (FDC) of rifampicin (RMP), isoniazid (INH), pyrazinamide (PZA) and ethambutol (EMB) sold on the Indian market. The products were stored for 3 months under ICH/WHO accelerated conditions (40 degrees C / 75% RH), with and without the original packaging in the presence and absence of light. The initial RMP, INH and PZA content was found to be within the range of 90-110% of the label claim. However, the products were found to have some chemical instability even initially; one of the tablets also showed physical instability. Under accelerated conditions, the unpackaged products underwent severe changes, whereas both physical and chemical changes were also observed in the packaged formulations. The physical changes were stronger under lighted conditions. A significant finding is that PZA and perhaps EMB may play a catalytic role in the interaction between INH and RMP. This study suggests that, unless they are packed in barrier packaging, anti-tuberculosis FDC formulations should be considered unstable, and due consideration should be given to their development pharmaceutics, packaging and stability testing.

  2. Research Projects in Physics: A Mechanism for Teaching Ill-Structured Problem Solving

    NASA Astrophysics Data System (ADS)

    Milbourne, Jeff; Bennett, Jonathan

    2017-10-01

    Physics education research has a tradition of studying problem solving, exploring themes such as physical intuition and differences between expert and novice problem solvers. However, most of this work has focused on traditional, or well-structured, problems, similar to what might appear in a textbook. Less work has been done with open-ended, or ill-structured, problems, similar to the types of problems students might face in their professional lives. Given the national discourse on educational system reform aligned with 21st century skills, including problem solving, it is critical to provide educational experiences that help students learn to solve all types of problems, including ill-structured problems.

  3. Including Critical Thinking and Problem Solving in Physical Education

    ERIC Educational Resources Information Center

    Pill, Shane; SueSee, Brendan

    2017-01-01

    Many physical education curriculum frameworks include statements about the inclusion of critical inquiry processes and the development of creativity and problem-solving skills. The learning environment created by physical education can encourage or limit the application and development of the learners' cognitive resources for critical and creative…

  4. Parental Physical Force and Alcohol Use in Emerging Adults: Mediation by Psychological Problems.

    PubMed

    Pollard, Mary Ward; McKinney, Cliff

    2016-07-01

    Research has indicated that negative parenting practices, such as physical punishment, are associated with negative outcomes in children. These negative outcomes can present during childhood and during emerging adulthood. One negative consequence can be excessive alcohol use, a problematic outcome with its own myriad consequences. The goal of the current study was to examine the effects of parental physical force on emerging adult functioning, specifically alcohol and psychological problems. A sample of 488 young adults completed questionnaires on current perceptions related to alcohol-related problems, physical and psychological aggression by their parents experienced during the previous year, and current emotional and behavioral functioning. Results showed full mediation between paternal physical force and emerging adult alcohol problems by emerging adult psychological problems. Emerging adult psychological problems partially mediated the effect of maternal physical force on emerging adult alcohol problem. Gender did not moderate these effects. The results support existing literature suggesting that the use of parental physical force may lead to a chain reaction of problems, even during emerging adulthood. These results also reveal that emerging adults report currently receiving physical force from their parents, which brings to light a concerning lack of literature on the use of parental physical force on emerging adult children. These results advocate for positive parenting practives and efforts to teach them, even for emerging adult children. The results may also clinically suggest that paying attention to parental force in emerging adult clients could yield a better understanding of their current functioning, especially including excessive alcohol use.

  5. Figuring the Acceleration of the Simple Pendulum

    NASA Astrophysics Data System (ADS)

    Lieberherr, Martin

    2011-12-01

    The centripetal acceleration has been known since Huygens' (1659) and Newton's (1684) time.1,2 The physics to calculate the acceleration of a simple pendulum has been around for more than 300 years, and a fairly complete treatise has been given by C. Schwarz in this journal.3 But sentences like "the acceleration is always directed towards the equilibrium position" beside the picture of a swing on a circular arc can still be found in textbooks, as e.g. in Ref. 4. Vectors have been invented by Grassmann (1844)5 and are conveniently used to describe the acceleration in curved orbits, but acceleration is more often treated as a scalar with or without sign, as the words acceleration/deceleration suggest. The component tangential to the orbit is enough to deduce the period of the simple pendulum, but it is not enough to discuss the forces on the pendulum, as has been pointed out by Santos-Benito and A. Gras-Marti.6 A suitable way to address this problem is a nice figure with a catch for classroom discussions or homework. When I plotted the acceleration vectors of the simple pendulum in their proper positions, pictures as in Fig. 1 appeared on the screen. The endpoints of the acceleration vectors, if properly scaled, seemed to lie on a curve with a familiar shape: a cardioid. Is this true or just an illusion?

  6. Frontier applications of electrostatic accelerators

    NASA Astrophysics Data System (ADS)

    Liu, Ke-Xin; Wang, Yu-Gang; Fan, Tie-Shuan; Zhang, Guo-Hui; Chen, Jia-Er

    2013-10-01

    Electrostatic accelerator is a powerful tool in many research fields, such as nuclear physics, radiation biology, material science, archaeology and earth sciences. Two electrostatic accelerators, one is the single stage Van de Graaff with terminal voltage of 4.5 MV and another one is the EN tandem with terminal voltage of 6 MV, were installed in 1980s and had been put into operation since the early 1990s at the Institute of Heavy Ion Physics. Many applications have been carried out since then. These two accelerators are described and summaries of the most important applications on neutron physics and technology, radiation biology and material science, as well as accelerator mass spectrometry (AMS) are presented.

  7. 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…

  8. 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.

  9. Comparison of accelerator physics issues for symmetric and asymmetric B-factory rings

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

    Tigner, M.

    1990-10-10

    A systematic comparison of accelerator physics issues from the beam-beam interaction to single particle stability including ring and IR layout, synchrotron radiation and lost particle backgrounds, and single and multi-bunch instabilities is given. While some practical handicap probably accrues to the asymmetric design because of its extra constraints, the differences in the two approaches tend to be obscured by larger issues such as how to achieve the enormous increases in luminosity demanded of a b-factory.

  10. Solar Physics - Plasma Physics Workshop

    NASA Technical Reports Server (NTRS)

    Baum, P. J.; Beckers, J. M.; Newman, C. E.; Priest, E. R.; Rosenberg, H.; Smith, D. F.; Sturrock, P. A.; Wentzel, D. G.

    1974-01-01

    A summary of the proceedings of a conference whose purpose was to explore plasma physics problems which arise in the study of solar physics is provided. Sessions were concerned with specific questions including the following: (1) whether the solar plasma is thermal or non-themal; (2) what spectroscopic data is required; (3) what types of magnetic field structures exist; (4) whether magnetohydrodynamic instabilities occur; (5) whether resistive or non-magnetohydrodynamic instabilities occur; (6) what mechanisms of particle acceleration have been proposed; and (7) what information is available concerning shock waves. Very few questions were answered categorically but, for each question, there was discussion concerning the observational evidence, theoretical analyses, and existing or potential laboratory and numerical experiments.

  11. Determining Students' Attitude towards Physics through Problem-Solving Strategy

    ERIC Educational Resources Information Center

    Erdemir, Naki

    2009-01-01

    In this study, the effects of teacher-directed and self-directed problem-solving strategies on students' attitudes toward physics were explored. Problem-solving strategies were used with the experimental group, while the control group was instructed using traditional teaching methods. The study was conducted with 270 students at various high…

  12. 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…

  13. Separating Movement and Gravity Components in an Acceleration Signal and Implications for the Assessment of Human Daily Physical Activity

    PubMed Central

    van Hees, Vincent T.; Gorzelniak, Lukas; Dean León, Emmanuel Carlos; Eder, Martin; Pias, Marcelo; Taherian, Salman; Ekelund, Ulf; Renström, Frida; Franks, Paul W.; Horsch, Alexander; Brage, Søren

    2013-01-01

    Introduction Human body acceleration is often used as an indicator of daily physical activity in epidemiological research. Raw acceleration signals contain three basic components: movement, gravity, and noise. Separation of these becomes increasingly difficult during rotational movements. We aimed to evaluate five different methods (metrics) of processing acceleration signals on their ability to remove the gravitational component of acceleration during standardised mechanical movements and the implications for human daily physical activity assessment. Methods An industrial robot rotated accelerometers in the vertical plane. Radius, frequency, and angular range of motion were systematically varied. Three metrics (Euclidian norm minus one [ENMO], Euclidian norm of the high-pass filtered signals [HFEN], and HFEN plus Euclidean norm of low-pass filtered signals minus 1 g [HFEN+]) were derived for each experimental condition and compared against the reference acceleration (forward kinematics) of the robot arm. We then compared metrics derived from human acceleration signals from the wrist and hip in 97 adults (22–65 yr), and wrist in 63 women (20–35 yr) in whom daily activity-related energy expenditure (PAEE) was available. Results In the robot experiment, HFEN+ had lowest error during (vertical plane) rotations at an oscillating frequency higher than the filter cut-off frequency while for lower frequencies ENMO performed better. In the human experiments, metrics HFEN and ENMO on hip were most discrepant (within- and between-individual explained variance of 0.90 and 0.46, respectively). ENMO, HFEN and HFEN+ explained 34%, 30% and 36% of the variance in daily PAEE, respectively, compared to 26% for a metric which did not attempt to remove the gravitational component (metric EN). Conclusion In conclusion, none of the metrics as evaluated systematically outperformed all other metrics across a wide range of standardised kinematic conditions. However, choice of metric

  14. Separating movement and gravity components in an acceleration signal and implications for the assessment of human daily physical activity.

    PubMed

    van Hees, Vincent T; Gorzelniak, Lukas; Dean León, Emmanuel Carlos; Eder, Martin; Pias, Marcelo; Taherian, Salman; Ekelund, Ulf; Renström, Frida; Franks, Paul W; Horsch, Alexander; Brage, Søren

    2013-01-01

    Human body acceleration is often used as an indicator of daily physical activity in epidemiological research. Raw acceleration signals contain three basic components: movement, gravity, and noise. Separation of these becomes increasingly difficult during rotational movements. We aimed to evaluate five different methods (metrics) of processing acceleration signals on their ability to remove the gravitational component of acceleration during standardised mechanical movements and the implications for human daily physical activity assessment. An industrial robot rotated accelerometers in the vertical plane. Radius, frequency, and angular range of motion were systematically varied. Three metrics (Euclidian norm minus one [ENMO], Euclidian norm of the high-pass filtered signals [HFEN], and HFEN plus Euclidean norm of low-pass filtered signals minus 1 g [HFEN+]) were derived for each experimental condition and compared against the reference acceleration (forward kinematics) of the robot arm. We then compared metrics derived from human acceleration signals from the wrist and hip in 97 adults (22-65 yr), and wrist in 63 women (20-35 yr) in whom daily activity-related energy expenditure (PAEE) was available. In the robot experiment, HFEN+ had lowest error during (vertical plane) rotations at an oscillating frequency higher than the filter cut-off frequency while for lower frequencies ENMO performed better. In the human experiments, metrics HFEN and ENMO on hip were most discrepant (within- and between-individual explained variance of 0.90 and 0.46, respectively). ENMO, HFEN and HFEN+ explained 34%, 30% and 36% of the variance in daily PAEE, respectively, compared to 26% for a metric which did not attempt to remove the gravitational component (metric EN). In conclusion, none of the metrics as evaluated systematically outperformed all other metrics across a wide range of standardised kinematic conditions. However, choice of metric explains different degrees of variance in

  15. Terascale Computing in Accelerator Science and Technology

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

    Ko, Kwok

    2002-08-21

    We have entered the age of ''terascale'' scientific computing. Processors and system architecture both continue to evolve; hundred-teraFLOP computers are expected in the next few years, and petaFLOP computers toward the end of this decade are conceivable. This ever-increasing power to solve previously intractable numerical problems benefits almost every field of science and engineering and is revolutionizing some of them, notably including accelerator physics and technology. At existing accelerators, it will help us optimize performance, expand operational parameter envelopes, and increase reliability. Design decisions for next-generation machines will be informed by unprecedented comprehensive and accurate modeling, as well as computer-aidedmore » engineering; all this will increase the likelihood that even their most advanced subsystems can be commissioned on time, within budget, and up to specifications. Advanced computing is also vital to developing new means of acceleration and exploring the behavior of beams under extreme conditions. With continued progress it will someday become reasonable to speak of a complete numerical model of all phenomena important to a particular accelerator.« less

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

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

    NONE

    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 themore » 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.« less

  17. Problem Solving: Physics Modeling-Based Interactive Engagement

    ERIC Educational Resources Information Center

    Ornek, Funda

    2009-01-01

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

  18. 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.

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

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

    Merzari, E.; Shemon, E. R.; Yu, Y. Q.

    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 ofmore » 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.« less

  20. Prevalence of physical health problems among youth entering residential treatment.

    PubMed

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

    2011-11-01

    To examine the prevalence of physical health problems among youth entering residential treatment. The sample included 1744 youth (mean age: 14.6 ± 1.8 years) entering a large residential treatment program between 2000 and 2010. Youth received an intake medical evaluation, including a review of available records, detailed medical history, and physical examination. Medical conditions present at the time of the evaluation were recorded by the examining physician and later coded by the research team. Only diagnoses recognized by the International Classification of Diseases, 10th Revision, were included in the analyses. To maintain the focus on physical health problems, behavioral and emotional disorders listed in the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision were excluded. Obesity, acne, and allergies were also excluded. Approximately one-third (33.7%) of youth had a physical health diagnosis at the time of intake. Asthma was the most prevalent condition diagnosed (15.3% of the sample). Girls were significantly more likely to have a diagnosis than were boys (37.1% vs 31.5%). Age was not associated with diagnostic status. Rates of physical health conditions differed significantly by ethnicity: black (36.4%) and white (35.4%) youth had the highest rates, and Hispanic youth (23.2%) had the lowest. Youth who enter residential treatment have high rates of physical health conditions. These problems could complicate mental health treatment and should be considered in multidisciplinary treatment planning.

  1. What Is Physics Problem-Solving Competency? The Views of Arnold Sommerfeld and Enrico Fermi

    NASA Astrophysics Data System (ADS)

    Niss, Martin

    2018-05-01

    A central goal of physics education is to teach problem-solving competency, but the description of the nature of this competency is somehwat fragmentary and implicit in the literature. The present article uses recent historical scholarship on Arnold Sommerfeld and Enrico Fermi to identify and characterize two positions on the nature of physics problem-solving competency. The first, Sommerfeld's, is a "theory first, phenomenon second" approach. Here, the relevant problems originate in one of the theories of physics and the goal of the problem-solver is to make a mathematical analysis of the relevant equation(s) and then give a qualitative analysis of the phenomenon that arise from these mathematical results. Fermi's position is a "phenomenon first, theory second" approach, where the starting point is a physical phenomenon that is analyzed and then brought into the realm of a physics theory. The two positions are illustrated with solutions to two problems and it is shown that the two positions are reflected in problem collections of university educations in physics.

  2. 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…

  3. 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.

  4. Problem Solving and the Use of Math in Physics Courses

    ERIC Educational Resources Information Center

    Redish, Edward F.

    2006-01-01

    Mathematics is an essential element of physics problem solving, but experts often fail to appreciate exactly how they use it. Math may be the language of science, but math-in-physics is a distinct dialect of that language. Physicists tend to blend conceptual physics with mathematical symbolism in a way that profoundly affects the way equations are…

  5. Conceptual design of a 15-TW pulsed-power accelerator for high-energy-density–physics experiments

    DOE PAGES

    Spielman, R. B.; Froula, D. H.; Brent, G.; ...

    2017-06-21

    We have developed a conceptual design of a 15-TW pulsed-power accelerator based on the linear-transformer-driver (LTD) architecture described by Stygar [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The driver will allow multiple, high-energy-density experiments per day in a university environment and, at the same time, will enable both fundamental and integrated experiments that are scalable to larger facilities. In this design, many individual energy storage units (bricks), each composed of two capacitors and one switch, directly drive the target load without additional pulse compression. Ten LTD modules in parallel drive the load. Each modulemore » consists of 16 LTD cavities connected in series, where each cavity is powered by 22 bricks connected in parallel. This design stores up to 2.75 MJ and delivers up to 15 TW in 100 ns to the constant-impedance, water-insulated radial transmission lines. The transmission lines in turn deliver a peak current as high as 12.5 MA to the physics load. To maximize its experimental value and flexibility, the accelerator is coupled to a modern, multibeam laser facility (four beams with up to 5 kJ in 10 ns and one beam with up to 2.6 kJ in 100 ps or less) that can provide auxiliary heating of the physics load. The lasers also enable advanced diagnostic techniques such as x-ray Thomson scattering and multiframe and three-dimensional radiography. In conclusion, the coupled accelerator-laser facility will be the first of its kind and be capable of conducting unprecedented high-energy-density-physics experiments.« less

  6. Conceptual design of a 15-TW pulsed-power accelerator for high-energy-density–physics experiments

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

    Spielman, R. B.; Froula, D. H.; Brent, G.

    We have developed a conceptual design of a 15-TW pulsed-power accelerator based on the linear-transformer-driver (LTD) architecture described by Stygar [W. A. Stygar et al., Phys. Rev. ST Accel. Beams 18, 110401 (2015)]. The driver will allow multiple, high-energy-density experiments per day in a university environment and, at the same time, will enable both fundamental and integrated experiments that are scalable to larger facilities. In this design, many individual energy storage units (bricks), each composed of two capacitors and one switch, directly drive the target load without additional pulse compression. Ten LTD modules in parallel drive the load. Each modulemore » consists of 16 LTD cavities connected in series, where each cavity is powered by 22 bricks connected in parallel. This design stores up to 2.75 MJ and delivers up to 15 TW in 100 ns to the constant-impedance, water-insulated radial transmission lines. The transmission lines in turn deliver a peak current as high as 12.5 MA to the physics load. To maximize its experimental value and flexibility, the accelerator is coupled to a modern, multibeam laser facility (four beams with up to 5 kJ in 10 ns and one beam with up to 2.6 kJ in 100 ps or less) that can provide auxiliary heating of the physics load. The lasers also enable advanced diagnostic techniques such as x-ray Thomson scattering and multiframe and three-dimensional radiography. In conclusion, the coupled accelerator-laser facility will be the first of its kind and be capable of conducting unprecedented high-energy-density-physics experiments.« less

  7. 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…

  8. Proposal for an Accelerator R&D User Facility at Fermilab's Advanced Superconducting Test Accelerator (ASTA)

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

    Church, M.; Edwards, H.; Harms, E.

    2013-10-01

    Fermilab is the nation’s particle physics laboratory, supported by the DOE Office of High Energy Physics (OHEP). Fermilab is a world leader in accelerators, with a demonstrated track-record— spanning four decades—of excellence in accelerator science and technology. We describe the significant opportunity to complete, in a highly leveraged manner, a unique accelerator research facility that supports the broad strategic goals in accelerator science and technology within the OHEP. While the US accelerator-based HEP program is oriented toward the Intensity Frontier, which requires modern superconducting linear accelerators and advanced highintensity storage rings, there are no accelerator test facilities that support themore » accelerator science of the Intensity Frontier. Further, nearly all proposed future accelerators for Discovery Science will rely on superconducting radiofrequency (SRF) acceleration, yet there are no dedicated test facilities to study SRF capabilities for beam acceleration and manipulation in prototypic conditions. Finally, there are a wide range of experiments and research programs beyond particle physics that require the unique beam parameters that will only be available at Fermilab’s Advanced Superconducting Test Accelerator (ASTA). To address these needs we submit this proposal for an Accelerator R&D User Facility at ASTA. The ASTA program is based on the capability provided by an SRF linac (which provides electron beams from 50 MeV to nearly 1 GeV) and a small storage ring (with the ability to store either electrons or protons) to enable a broad range of beam-based experiments to study fundamental limitations to beam intensity and to develop transformative approaches to particle-beam generation, acceleration and manipulation which cannot be done elsewhere. It will also establish a unique resource for R&D towards Energy Frontier facilities and a test-bed for SRF accelerators and high brightness beam applications in support of the

  9. 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.

  10. 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.

  11. Toward the automated analysis of plasma physics problems

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

    Mynick, H.E.

    1989-04-01

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

  12. The Dresden Felsenkeller shallow-underground accelerator laboratory for nuclear astrophysics - Status and first physics program

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

    Ilgner, Ch.

    Favored by the low background in underground laboratories, low-background accelerator-based experiments are an important tool to study nuclear reactions involving stable charged particles. This technique has been used for many years with great success at the 0.4 MV LUNA accelerator in the Gran Sasso laboratory in Italy, protected from cosmic rays by 1400 m of rock. However, the nuclear reactions of helium and carbon burning and the neutron source reactions for the astrophysical s-process require higher beam energies than those available at LUNA. Also the study of solar fusion reactions necessitates new data at higher energies. As a result, inmore » the present NuPECC long range plan for nuclear physics in Europe, the installation of one or more higher-energy underground accelerators is strongly recommended. An intercomparison exercise using the same High-Purity Ge detector at several sites has shown that, with a combination of 45 m rock overburden, as can be found in the Felsenkeller underground site in Dresden, and an active veto against the remaining muon flux, in a typical nuclear astrophysics setup a background level can be achieved that is similar to the deep underground scenario as in the Gran- Sasso underground laboratory, for instance. Recently, a muon background study and geodetic measurements were carried out by the REGARD group. It was estimated that the rock overburden at the place of the future ion accelerator is equivalent to 130 m of water. The maximum muon flux measured was 2.5 m{sup -2} sr{sup -1} s{sup -1}, in the direction of the tunnel entrance. Based on this finding, a used 5 MV pelletron tandem accelerator with 250 μA up-charge current and external sputter ion source has been obtained and transported to Dresden. Work on an additional radio-frequency ion source on the high voltage terminal is in progress and far advanced. The installation of the accelerator in the Felsenkeller is expected for the near future. The status of the project and

  13. 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.

  14. Neutrino Physics with Accelerator Driven Subcritical Reactors

    NASA Astrophysics Data System (ADS)

    Ciuffoli, Emilio

    2017-09-01

    Accelerator Driven Subcritical System (ADS) reactors are being developed around the world, to produce energy and, at the same time, to provide an efficient way to dispose of and to recycle nuclear waste. Used nuclear fuel, by itself, cannot sustain a chain reaction; however in ADS reactors the additional neutrons which are required will be supplied by a high-intensity accelerator. This accelerator will produce, as a by-product, a large quantity of {\\bar{ν }}μ via muon Decay At Rest (µDAR). Using liquid scintillators, it will be possible to to measure the CP-violating phase δCP and to look for experimental signs of the presence of sterile neutrinos in the appearance channel, testing the LSND and MiniBooNE anomalies. Even in the first stage of the project, when the beam energy will be lower, it will be possible to produce {\\bar{ν }}e via Isotope Decay At Rest (IsoDAR), which can be used to provide competitive bounds on sterile neutrinos in the disappearance channel. I will consider several experimental setups in which the antineutrinos are created using accelerators that will be constructed as part of the China-ADS program.

  15. 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

  16. The physical properties of accelerated Portland cement for endodontic use.

    PubMed

    Camilleri, J

    2008-02-01

    To investigate the physical properties of a novel accelerated Portland cement. The setting time, compressive strength, pH and solubility of white Portland cement (Lafarge Asland; CEM 1, 52.5 N) and accelerated Portland cement (Proto A) produced by excluding gypsum from the manufacturing process (Aalborg White) and a modified version with 4 : 1 addition of bismuth oxide (Proto B) were evaluated. Proto A set in 8 min. The compressive strength of Proto A was comparable with that of Portland cement at all testing periods (P > 0.05). Additions of bismuth oxide extended the setting time and reduced the compressive strength (P < 0.05). Both cements and storage solution were alkaline. All cements tested increased by >12% of their original weight after immersion in water for 1 day with no further absorption after 28 days. Addition of bismuth oxide increased the water uptake of the novel cement (P < 0.05). The setting time of Portland cement can be reduced by excluding the gypsum during the last stage of the manufacturing process without affecting its other properties. Addition of bismuth oxide affected the properties of the novel cement. Further investigation on the effect that bismuth oxide has on the properties of mineral trioxide aggregate is thus warranted.

  17. How do classical particle-field systems become unstable? - The last physics problem that Ronald Davidson studied

    NASA Astrophysics Data System (ADS)

    Qin, Hong

    2016-10-01

    Many of the classical particle-field systems in (neutral and nonneutral) plasma physics and accelerator physics become unstable when the system parameters vary. How do these instabilities happen? It turns out, very interestingly, that all conservative systems become unstable by the same mechanism, i.e, the resonance between a positive- and a negative-action modes. And this is the only route that a stable system can become unstable. In this talk, I will use several examples in plasma physics and accelerator physics with finite and infinite degrees of freedom to illustrate the basic physical picture and the rigorous theoretical structure of the process. The features at the transition between stable and unstable regions in the parameter space are the fundamental characteristics of the underlying real Hamiltonian system and complex G-Hamiltonian system. The resonance between a positive- and a negative-action modes at the transition is the Krein collision well-known to mathematicians. Research supported by the U.S. Department of Energy (DE-AC02-09CH11466).

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

    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. Attitude and practice of physical activity and social problem-solving ability among university students.

    PubMed

    Sone, Toshimasa; Kawachi, Yousuke; Abe, Chihiro; Otomo, Yuki; Sung, Yul-Wan; Ogawa, Seiji

    2017-04-04

    Effective social problem-solving abilities can contribute to decreased risk of poor mental health. In addition, physical activity has a favorable effect on mental health. These previous studies suggest that physical activity and social problem-solving ability can interact by helping to sustain mental health. The present study aimed to determine the association between attitude and practice of physical activity and social problem-solving ability among university students. Information on physical activity and social problem-solving was collected using a self-administered questionnaire. We analyzed data from 185 students who participated in the questionnaire surveys and psychological tests. Social problem-solving as measured by the Social Problem-Solving Inventory-Revised (SPSI-R) (median score 10.85) was the dependent variable. Multiple logistic regression analysis was employed to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) for higher SPSI-R according to physical activity categories. The multiple logistic regression analysis indicated that the ORs (95% CI) in reference to participants who said they never considered exercising were 2.08 (0.69-6.93), 1.62 (0.55-5.26), 2.78 (0.86-9.77), and 6.23 (1.81-23.97) for participants who did not exercise but intended to start, tried to exercise but did not, exercised but not regularly, and exercised regularly, respectively. This finding suggested that positive linear association between physical activity and social problem-solving ability (p value for linear trend < 0.01). The present findings suggest that regular physical activity or intention to start physical activity may be an effective strategy to improve social problem-solving ability.

  20. Dissociative conceptual and quantitative problem solving outcomes across interactive engagement and traditional format introductory physics

    NASA Astrophysics Data System (ADS)

    McDaniel, Mark A.; Stoen, Siera M.; Frey, Regina F.; Markow, Zachary E.; Hynes, K. Mairin; Zhao, Jiuqing; Cahill, Michael J.

    2016-12-01

    The existing literature indicates that interactive-engagement (IE) based general physics classes improve conceptual learning relative to more traditional lecture-oriented classrooms. Very little research, however, has examined quantitative problem-solving outcomes from IE based relative to traditional lecture-based physics classes. The present study included both pre- and post-course conceptual-learning assessments and a new quantitative physics problem-solving assessment that included three representative conservation of energy problems from a first-semester calculus-based college physics course. Scores for problem translation, plan coherence, solution execution, and evaluation of solution plausibility were extracted for each problem. Over 450 students in three IE-based sections and two traditional lecture sections taught at the same university during the same semester participated. As expected, the IE-based course produced more robust gains on a Force Concept Inventory than did the lecture course. By contrast, when the full sample was considered, gains in quantitative problem solving were significantly greater for lecture than IE-based physics; when students were matched on pre-test scores, there was still no advantage for IE-based physics on gains in quantitative problem solving. Further, the association between performance on the concept inventory and quantitative problem solving was minimal. These results highlight that improved conceptual understanding does not necessarily support improved quantitative physics problem solving, and that the instructional method appears to have less bearing on gains in quantitative problem solving than does the kinds of problems emphasized in the courses and homework and the overlap of these problems to those on the assessment.

  1. On the Physics of Drag Racing

    ERIC Educational Resources Information Center

    Fox, Geoffrey T.

    1973-01-01

    This sport can be usefully examined in an introductory mechanics course. The concepts of energy, momentum, acceleration, velocity, torque, and power are all involved in the analysis of the problem. High interest among the students usually results in increased understanding of the physical principles involved. (Author/DF)

  2. Case of Two Electrostatics Problems: Can Providing a Diagram Adversely Impact Introductory Physics Students' Problem Solving Performance?

    ERIC Educational Resources Information Center

    Maries, Alexandru; Singh, Chandralekha

    2018-01-01

    Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an…

  3. Use of model analysis to analyse Thai students’ attitudes and approaches to physics problem solving

    NASA Astrophysics Data System (ADS)

    Rakkapao, S.; Prasitpong, S.

    2018-03-01

    This study applies the model analysis technique to explore the distribution of Thai students’ attitudes and approaches to physics problem solving and how those attitudes and approaches change as a result of different experiences in physics learning. We administered the Attitudes and Approaches to Problem Solving (AAPS) survey to over 700 Thai university students from five different levels, namely students entering science, first-year science students, and second-, third- and fourth-year physics students. We found that their inferred mental states were generally mixed. The largest gap between physics experts and all levels of the students was about the role of equations and formulas in physics problem solving, and in views towards difficult problems. Most participants of all levels believed that being able to handle the mathematics is the most important part of physics problem solving. Most students’ views did not change even though they gained experiences in physics learning.

  4. 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.

  5. Brane with variable tension as a possible solution to the problem of the late cosmic acceleration

    NASA Astrophysics Data System (ADS)

    García-Aspeitia, Miguel A.; Hernandez-Almada, A.; Magaña, Juan; Amante, Mario H.; Motta, V.; Martínez-Robles, C.

    2018-05-01

    Braneworld models have been proposed as a possible solution to the problem of the accelerated expansion of the Universe. The idea is to dispense the dark energy (DE) and drive the late-time cosmic acceleration with a five-dimensional geometry. We investigate a brane model with variable brane tension as a function of redshift called chrono-brane. We propose the polynomial λ =(1 +z )n function inspired in tracker-scalar-field potentials. To constrain the n exponent we use the latest observational Hubble data from cosmic chronometers, Type Ia Supernovae from the full joint-light-analysis sample, baryon acoustic oscillations and the posterior distance from the cosmic microwave background of Planck 2015 measurements. A joint analysis of these data estimates n ≃6.19 ±0.12 which generates a DE-like (cosmological-constantlike at late times) term, in the Friedmann equation arising from the extra dimensions. This model is consistent with these data and can drive the Universe to an accelerated phase at late times.

  6. Analysis of Anderson Acceleration on a Simplified Neutronics/Thermal Hydraulics System

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

    Toth, Alex; Kelley, C. T.; Slattery, Stuart R

    ABSTRACT A standard method for solving coupled multiphysics problems in light water reactors is Picard iteration, which sequentially alternates between solving single physics applications. This solution approach is appealing due to simplicity of implementation and the ability to leverage existing software packages to accurately solve single physics applications. However, there are several drawbacks in the convergence behavior of this method; namely slow convergence and the necessity of heuristically chosen damping factors to achieve convergence in many cases. Anderson acceleration is a method that has been seen to be more robust and fast converging than Picard iteration for many problems, withoutmore » significantly higher cost per iteration or complexity of implementation, though its effectiveness in the context of multiphysics coupling is not well explored. In this work, we develop a one-dimensional model simulating the coupling between the neutron distribution and fuel and coolant properties in a single fuel pin. We show that this model generally captures the convergence issues noted in Picard iterations which couple high-fidelity physics codes. We then use this model to gauge potential improvements with regard to rate of convergence and robustness from utilizing Anderson acceleration as an alternative to Picard iteration.« less

  7. Fundamentals of Physics, Part 1 (Chapters 1-11)

    NASA Astrophysics Data System (ADS)

    Halliday, David; Resnick, Robert; Walker, Jearl

    2003-12-01

    Chapter 1.Measurement. How does the appearance of a new type of cloud signal changes in Earth's atmosphere? 1-1 What Is Physics? 1-2 Measuring Things. 1-3 The International System of Units. 1-4 Changing Units. 1-5 Length. 1-6 Time. 1-7 Mass. Review & Summary. Problems. Chapter 2.Motion Along a Straight Line. What causes whiplash injury in rear-end collisions of cars? 2-1 What Is Physics? 2-2 Motion. 2-3 Position and Displacement. 2-4 Average Velocity and Average Speed. 2-5 Instantaneous Velocity and Speed. 2-6 Acceleration. 2-7 Constant Acceleration: A Special Case. 2-8 Another Look at Constant Acceleration. 2-9 Free-Fall Acceleration. 2-10 Graphical Integration in Motion Analysis. Review & Summary. Questions. Problems. Chapter 3.Vectors. How does an ant know the way home with no guiding clues on the deser t plains? 3-2 Vectors and Scalars. 3-3 Adding Vectors Geometrically. 3-4 Components of Vectors. 3-5 Unit Vectors. 3-6 Adding Vectors by Components. 3-7 Vectors and the Laws of Physics. 3-8 Multiplying Vectors. Review & Summary. Questions. Problems. Chapter 4.Motion in Two and Three Dimensions. In a motorcycle jump for record distance, where does the jumper put the second ramp? 4-1 What Is Physics? 4-2 Position and Displacement. 4-3 Average Velocity and Instantaneous Velocity. 4-4 Average Acceleration and Instantaneous Acceleration. 4-5 Projectile Motion. 4-6 Projectile Motion Analyzed. 4-7 Uniform Circular Motion. 4-8 Relative Motion in One Dimension. 4-9 Relative Motion in Two Dimensions. Review & Summary. Questions. Problems. Chapter 5.Force and Motion-I. When a pilot takes off from an aircraft carrier, what causes the compulsion to fly the plane into the ocean? 5-1 What Is Physics? 5-2 Newtonian Mechanics. 5-3 Newton's First Law. 5-4 Force. 5-5 Mass. 5-6 Newton's Second Law. 5-7 Some Particular Forces. 5-8 Newton's Third Law. 5-9 Applying Newton's Laws. Review & Summary. Questions. Problems. Chapter 6.Force and Motion-II. Can a Grand Prix race car be driven

  8. 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.

  9. An Overview of Problem Solving Studies in Physics Education

    ERIC Educational Resources Information Center

    Ince, Elif

    2018-01-01

    Education policies today aim to raise individuals with 21st Century skills considered as a universal necessity and problem-solving skill is the one of the skills that have emerged as a requirement of the 21st century. Teaching problem solving is one of the most important topics of physics education, it is also the field where students have the…

  10. REVIEWS OF TOPICAL PROBLEMS: Acceleration of cosmic rays by shock waves

    NASA Astrophysics Data System (ADS)

    Berezhko, E. G.; Krymskiĭ, G. F.

    1988-01-01

    Theoretical work on various processes by which shock waves accelerate cosmic rays is reviewed. The most efficient of these processes, Fermi acceleration, is singled out for special attention. A linear theory for this process is presented. The results found on the basis of nonlinear models of Fermi acceleration, which incorporate the modification of the structure caused by the accelerated particles, are reported. There is a discussion of various possibilities for explaining the generation of high-energy particles observed in interplanetary and interstellar space on the basis of a Fermi acceleration mechanism. The acceleration by shock waves from supernova explosions is discussed as a possible source of galactic cosmic rays. The most important unresolved questions in the theory of acceleration of charged particles by shock waves are pointed out.

  11. Status of MAPA (Modular Accelerator Physics Analysis) and the Tech-X Object-Oriented Accelerator Library

    NASA Astrophysics Data System (ADS)

    Cary, J. R.; Shasharina, S.; Bruhwiler, D. L.

    1998-04-01

    The MAPA code is a fully interactive accelerator modeling and design tool consisting of a GUI and two object-oriented C++ libraries: a general library suitable for treatment of any dynamical system, and an accelerator library including many element types plus an accelerator class. The accelerator library inherits directly from the system library, which uses hash tables to store any relevant parameters or strings. The GUI can access these hash tables in a general way, allowing the user to invoke a window displaying all relevant parameters for a particular element type or for the accelerator class, with the option to change those parameters. The system library can advance an arbitrary number of dynamical variables through an arbitrary mapping. The accelerator class inherits this capability and overloads the relevant functions to advance the phase space variables of a charged particle through a string of elements. Among other things, the GUI makes phase space plots and finds fixed points of the map. We discuss the object hierarchy of the two libraries and use of the code.

  12. USPAS | U.S. Particle Accelerator School

    Science.gov Websites

    U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School U.S. Particle Accelerator School Education in Beam Physics and Accelerator Technology Home About About University Credits Joint International Accelerator School University-Style Programs Symposium-Style Programs

  13. Leveraging Anderson Acceleration for improved convergence of iterative solutions to transport systems

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

    Willert, Jeffrey; Taitano, William T.; Knoll, Dana

    In this note we demonstrate that using Anderson Acceleration (AA) in place of a standard Picard iteration can not only increase the convergence rate but also make the iteration more robust for two transport applications. We also compare the convergence acceleration provided by AA to that provided by moment-based acceleration methods. Additionally, we demonstrate that those two acceleration methods can be used together in a nested fashion. We begin by describing the AA algorithm. At this point, we will describe two application problems, one from neutronics and one from plasma physics, on which we will apply AA. We provide computationalmore » results which highlight the benefits of using AA, namely that we can compute solutions using fewer function evaluations, larger time-steps, and achieve a more robust iteration.« less

  14. Physics-Based Fragment Acceleration Modeling for Pressurized Tank Burst Risk Assessments

    NASA Technical Reports Server (NTRS)

    Manning, Ted A.; Lawrence, Scott L.

    2014-01-01

    As part of comprehensive efforts to develop physics-based risk assessment techniques for space systems at NASA, coupled computational fluid and rigid body dynamic simulations were carried out to investigate the flow mechanisms that accelerate tank fragments in bursting pressurized vessels. Simulations of several configurations were compared to analyses based on the industry-standard Baker explosion model, and were used to formulate an improved version of the model. The standard model, which neglects an external fluid, was found to agree best with simulation results only in configurations where the internal-to-external pressure ratio is very high and fragment curvature is small. The improved model introduces terms that accommodate an external fluid and better account for variations based on circumferential fragment count. Physics-based analysis was critical in increasing the model's range of applicability. The improved tank burst model can be used to produce more accurate risk assessments of space vehicle failure modes that involve high-speed debris, such as exploding propellant tanks and bursting rocket engines.

  15. Future HEP Accelerators: The US Perspective

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

    Bhat, Pushpalatha; Shiltsev, Vladimir

    2015-11-02

    Accelerator technology has advanced tremendously since the introduction of accelerators in the 1930s, and particle accelerators have become indispensable instruments in high energy physics (HEP) research to probe Nature at smaller and smaller distances. At present, accelerator facilities can be classified into Energy Frontier colliders that enable direct discoveries and studies of high mass scale particles and Intensity Frontier accelerators for exploration of extremely rare processes, usually at relatively low energies. The near term strategies of the global energy frontier particle physics community are centered on fully exploiting the physics potential of the Large Hadron Collider (LHC) at CERN throughmore » its high-luminosity upgrade (HL-LHC), while the intensity frontier HEP research is focused on studies of neutrinos at the MW-scale beam power accelerator facilities, such as Fermilab Main Injector with the planned PIP-II SRF linac project. A number of next generation accelerator facilities have been proposed and are currently under consideration for the medium- and long-term future programs of accelerator-based HEP research. In this paper, we briefly review the post-LHC energy frontier options, both for lepton and hadron colliders in various regions of the world, as well as possible future intensity frontier accelerator facilities.« less

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

    ERIC Educational Resources Information Center

    De Lozano, Silvia Ragout; Cardenas, Marta

    2002-01-01

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

  17. On the maximum energy achievable in the first order Fermi acceleration at shocks

    NASA Astrophysics Data System (ADS)

    Grozny, I.; Diamond, P.; Malkov, M.

    2002-11-01

    Astrophysical shocks are considered as the sites of cosmic ray (CR) production. The primary mechanism is the diffusive shock (Fermi) acceleration which operates via multiple shock recrossing by a particle. Its efficiency, the rate of energy gain, and the maximum energy are thus determined by the transport mechanisms (confinement to the shock) of these particles in a turbulent shock environment. The turbulence is believed to be generated by accelerated particles themselves. Moreover, in the most interesting case of efficient acceleration the entire MHD shock structure is dominated by their pressure. This makes this problem one of the challenging strongly nonlinear problems of astrophysics. We suggest a physical model that describes particle acceleration, shock structure and the CR driven turbulence on an equal footing. The key new element in this scheme is nonlinear cascading of the MHD turbulence on self-excited (via modulational and Drury instability) sound-like perturbations which gives rise to a significant enrichment of the long wave part of the MHD spectrum. This is critical for the calculation of the maximum energy.

  18. The emerging problem of physical child abuse in South Korea.

    PubMed

    Hahm, H C; Guterman, N B

    2001-05-01

    South Korea has had remarkably high incidence and prevalence rates of physical violence against children, yet the problem has received only limited public and professional attention until very recently. This article represents the first attempt in English to systematically analyze South Korea's recent epidemiological studies on child maltreatment. Discussed are sociocultural factors that have contributed both to delays in child protection laws and a low public awareness of the problem of child abuse. The article highlights methodological issues concerning the definition of physical abuse in South Korea and the complex attitudes toward violence. It also examines the role of the Korean women's movement in the reform of family laws and the recent establishment of new child protection legislation. Suggestions for future directions for the problem of child maltreatment within South Korea are presented.

  19. 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…

  20. Toward GPGPU accelerated human electromechanical cardiac simulations

    PubMed Central

    Vigueras, Guillermo; Roy, Ishani; Cookson, Andrew; Lee, Jack; Smith, Nicolas; Nordsletten, David

    2014-01-01

    In this paper, we look at the acceleration of weakly coupled electromechanics using the graphics processing unit (GPU). Specifically, we port to the GPU a number of components of Heart—a CPU-based finite element code developed for simulating multi-physics problems. On the basis of a criterion of computational cost, we implemented on the GPU the ODE and PDE solution steps for the electrophysiology problem and the Jacobian and residual evaluation for the mechanics problem. Performance of the GPU implementation is then compared with single core CPU (SC) execution as well as multi-core CPU (MC) computations with equivalent theoretical performance. Results show that for a human scale left ventricle mesh, GPU acceleration of the electrophysiology problem provided speedups of 164 × compared with SC and 5.5 times compared with MC for the solution of the ODE model. Speedup of up to 72 × compared with SC and 2.6 × compared with MC was also observed for the PDE solve. Using the same human geometry, the GPU implementation of mechanics residual/Jacobian computation provided speedups of up to 44 × compared with SC and 2.0 × compared with MC. © 2013 The Authors. International Journal for Numerical Methods in Biomedical Engineering published by John Wiley & Sons, Ltd. PMID:24115492

  1. Workplace bullying, sleep problems and leisure-time physical activity: a prospective cohort study.

    PubMed

    Hansen, Åse Marie; Gullander, Maria; Hogh, Annie; Persson, Roger; Kolstad, Henrik A; Willert, Morten Vejs; Bonde, Jens Peter; Kaerlev, Linda; Rugulies, Reiner; Grynderup, Matias Brødsgaard

    2016-01-01

    Workplace bullying is a potent stressor that may increase sleep problems. Since physical fitness improves resilience to stress, it seems plausible that recreational physical activities may moderate the association between bullying and sleep. The study aimed to examine prospectively whether (i) bullying increases the risk of sleep problems, and (ii) the association between bullying and sleep problems is moderated by leisure-time physical activity (LTPA). The study sample comprised a cohort of public and private sector employees, who were enrolled into the Work Bullying and Harassment (WBH) cohort (N=3278) or the Psychosocial Risk Factors for Stress and Mental Disease (PRISME) cohort (N=4455). We measured workplace bullying using one question that was preceded by a definition of bullying. We used the Karolinska sleep questionnaire to assess sleep problems. The number of hours per week spent on LTPA estimated the degree of physical activity. Workplace bullying at baseline (T1) was associated with awakening problems and lack of restful sleep at follow-up (T2) but not with overall sleep problems and disturbed sleep. T1-LTPA did not moderate the association between T1-workplace bullying and T2-sleep problems. We found support that workplace bullying is related to development of T2-sleep problems, but this association seems not to be modified by LTPA.

  2. Emotional and physical health problems of battered women.

    PubMed

    Jaffe, P; Wolfe, D A; Wilson, S; Zak, L

    1986-10-01

    The present study focused on the emotional and physical health problems of battered women by comparing a sample of residents in shelters with a group of women in the community matched for family income, length of marriage, and number of children on the General Health Questionnaire. The results indicated that battered women report a significantly higher level of somatic complaints, anxiety, and depression. These effects tended to be associated with other life stressors and children with serious behavior problems. The implications of the study are discussed in terms of assessing the needs of battered women and their children as well as being vigilant for family violence as an etiological factor for other presenting problems.

  3. Role of neutrino mixing in accelerated proton decay

    NASA Astrophysics Data System (ADS)

    Blasone, M.; Lambiase, G.; Luciano, G. G.; Petruzziello, L.

    2018-05-01

    The decay of accelerated protons has been analyzed both in the laboratory frame (where the proton is accelerated) and in the comoving frame (where the proton is at rest and interacts with the Fulling-Davies-Unruh thermal bath of electrons and neutrinos). The equality between the two rates has been exhibited as an evidence of the necessity of Fulling-Davies-Unruh effect for the consistency of quantum field theory formalism. Recently, it has been argued that neutrino mixing can spoil such a result, potentially opening new scenarios in neutrino physics. In the present paper, we analyze in detail this problem, and we find that, assuming flavor neutrinos to be fundamental and working within a certain approximation, the agreement can be restored.

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

    NASA Astrophysics Data System (ADS)

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

    2000-08-01

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

  5. 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.…

  6. The practice of problem-based investigative teaching reform in semiconductor physics course

    NASA Astrophysics Data System (ADS)

    Chen, Aiping; Wu, Gaojian; Gu, Dawei; Jiang, Hongying; Wang, Lei

    2017-08-01

    Semiconductor physics is an important basic course for the students of the majors of applied physics, optoelectronics, and microelectronics. The authors have been carrying out investigative-teaching reform in semiconductor physics teaching. Firstly, the teaching content was re-structured based on scientific problems. Secondly, the students were placed in groups to discuss different scientific problems and to present a few short science-reports. Thirdly, micro-lesson videos were produced for the students to study and analyze before or after class. With comparative analysis, we find out that the semiconductor-physics curriculum content was greatly enriched. In addition, the students' learning motivation and scientific thinking ability increased, and their innovation ability was improved. Overall, the teaching quality of the semiconductor physics course could be significantly improved.

  7. Plasma Wakefield Acceleration and FACET - Facilities for Accelerator Science and Experimental Test Beams at SLAC

    ScienceCinema

    Seryi, Andrei

    2017-12-22

    Plasma wakefield acceleration is one of the most promising approaches to advancing accelerator technology. This approach offers a potential 1,000-fold or more increase in acceleration over a given distance, compared to existing accelerators.  FACET, enabled by the Recovery Act funds, will study plasma acceleration, using short, intense pulses of electrons and positrons. In this lecture, the physics of plasma acceleration and features of FACET will be presented.  

  8. A new problem in mathematical physics associated with the problem of coherent phase transformation

    NASA Astrophysics Data System (ADS)

    Grinfeld, M. A.

    1985-06-01

    The description of heterogeneous coherent phase equilibria in an elastic single component system is shown to lead, in the approximation of small intrinsic deformation, to a new problem in mathematical physics with an unknown bound. The low order terms of the resulting system of equilibrium equations coincide with the equations of the classical linear theory of elasticity (generally speaking, anisotropic); however, the problem remains strongly nonlinear overall, inasmuch as it contains an unknown bound and a boundary condition on it which is quadratic with respect to translation. The formulas obtained are used to find certain explicit solutions to the boundary problems. As an example, the problem of heterogeneous equilibria in an infinite rectangular isotropic beam with free faces and constant loading on the surfaces x squared = const can be examined. A modeling problem for the asymptote of small intrinsic deformation during coherent phase transformation is presented as a scalar analog of the vector problem considered initially.

  9. Problem-Based Learning in the Physical Science Classroom, K-12

    ERIC Educational Resources Information Center

    McConnell, Tom J.; Parker, Joyce; Eberhardt, Janet

    2018-01-01

    "Problem-Based Learning in the Physical Science Classroom, K-12" will help your students truly understand concepts such as motion, energy, and magnetism in true-to-life contexts. The book offers a comprehensive description of why, how, and when to implement problem-based learning (PBL) in your curriculum. Its 14 developmentally…

  10. 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.

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

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

    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 coordinatemore » 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.« less

  12. 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

  13. EDITORIAL: Laser and plasma accelerators Laser and plasma accelerators

    NASA Astrophysics Data System (ADS)

    Bingham, Robert

    2009-02-01

    This special issue on laser and plasma accelerators illustrates the rapid advancement and diverse applications of laser and plasma accelerators. Plasma is an attractive medium for particle acceleration because of the high electric field it can sustain, with studies of acceleration processes remaining one of the most important areas of research in both laboratory and astrophysical plasmas. The rapid advance in laser and accelerator technology has led to the development of terawatt and petawatt laser systems with ultra-high intensities and short sub-picosecond pulses, which are used to generate wakefields in plasma. Recent successes include the demonstration by several groups in 2004 of quasi-monoenergetic electron beams by wakefields in the bubble regime with the GeV energy barrier being reached in 2006, and the energy doubling of the SLAC high-energy electron beam from 42 to 85 GeV. The electron beams generated by the laser plasma driven wakefields have good spatial quality with energies ranging from MeV to GeV. A unique feature is that they are ultra-short bunches with simulations showing that they can be as short as a few femtoseconds with low-energy spread, making these beams ideal for a variety of applications ranging from novel high-brightness radiation sources for medicine, material science and ultrafast time-resolved radiobiology or chemistry. Laser driven ion acceleration experiments have also made significant advances over the last few years with applications in laser fusion, nuclear physics and medicine. Attention is focused on the possibility of producing quasi-mono-energetic ions with energies ranging from hundreds of MeV to GeV per nucleon. New acceleration mechanisms are being studied, including ion acceleration from ultra-thin foils and direct laser acceleration. The application of wakefields or beat waves in other areas of science such as astrophysics and particle physics is beginning to take off, such as the study of cosmic accelerators considered

  14. The Effect of New Vocabulary on Problem Solving in Novice Physics Students.

    ERIC Educational Resources Information Center

    Sobolewski, Stanley J.

    One of the difficulties encountered by novice problem solvers in introductory physics is in the area of problem solving. It has been shown in other studies that poor problem solvers are affected by the surface aspects of the problem in contrast with more efficient problem solvers who are capable of constructing a mental model of the physical…

  15. Proceedings of the 1995 Particle Accelerator Conference and international Conference on High-Energy Accelerators

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

    None

    1996-01-01

    Papers from the sixteenth biennial Particle Accelerator Conference, an international forum on accelerator science and technology held May 1–5, 1995, in Dallas, Texas, organized by Los Alamos National Laboratory (LANL) and Stanford Linear Accelerator Center (SLAC), jointly sponsored by the Institute of Electrical and Electronics Engineers (IEEE) Nuclear and Plasma Sciences Society (NPSS), the American Physical Society (APS) Division of Particles and Beams (DPB), and the International Union of Pure and Applied Physics (IUPAP), and conducted with support from the US Department of Energy, the National Science Foundation, and the Office of Naval Research.

  16. Multigrid accelerated simulations for Twisted Mass fermions

    NASA Astrophysics Data System (ADS)

    Bacchio, Simone; Alexandrou, Constantia; Finkerath, Jacob

    2018-03-01

    Simulations at physical quark masses are affected by the critical slowing down of the solvers. Multigrid preconditioning has proved to deal effectively with this problem. Multigrid accelerated simulations at the physical value of the pion mass are being performed to generate Nf = 2 and Nf = 2 + 1 + 1 gauge ensembles using twisted mass fermions. The adaptive aggregation-based domain decomposition multigrid solver, referred to as DD-αAMG method, is employed for these simulations. Our simulation strategy consists of an hybrid approach of different solvers, involving the Conjugate Gradient (CG), multi-mass-shift CG and DD-αAMG solvers. We present an analysis of the multigrid performance during the simulations discussing the stability of the method. This significant speeds up the Hybrid Monte Carlo simulation by more than a factor 4 at physical pion mass compared to the usage of the CG solver.

  17. Anderson acceleration and application to the three-temperature energy equations

    NASA Astrophysics Data System (ADS)

    An, Hengbin; Jia, Xiaowei; Walker, Homer F.

    2017-10-01

    The Anderson acceleration method is an algorithm for accelerating the convergence of fixed-point iterations, including the Picard method. Anderson acceleration was first proposed in 1965 and, for some years, has been used successfully to accelerate the convergence of self-consistent field iterations in electronic-structure computations. Recently, the method has attracted growing attention in other application areas and among numerical analysts. Compared with a Newton-like method, an advantage of Anderson acceleration is that there is no need to form the Jacobian matrix. Thus the method is easy to implement. In this paper, an Anderson-accelerated Picard method is employed to solve the three-temperature energy equations, which are a type of strong nonlinear radiation-diffusion equations. Two strategies are used to improve the robustness of the Anderson acceleration method. One strategy is to adjust the iterates when necessary to satisfy the physical constraint. Another strategy is to monitor and, if necessary, reduce the matrix condition number of the least-squares problem in the Anderson-acceleration implementation so that numerical stability can be guaranteed. Numerical results show that the Anderson-accelerated Picard method can solve the three-temperature energy equations efficiently. Compared with the Picard method without acceleration, Anderson acceleration can reduce the number of iterations by at least half. A comparison between a Jacobian-free Newton-Krylov method, the Picard method, and the Anderson-accelerated Picard method is conducted in this paper.

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

    PubMed Central

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

    2015-01-01

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

  19. Electron acceleration by wave turbulence in a magnetized plasma

    NASA Astrophysics Data System (ADS)

    Rigby, A.; Cruz, F.; Albertazzi, B.; Bamford, R.; Bell, A. R.; Cross, J. E.; Fraschetti, F.; Graham, P.; Hara, Y.; Kozlowski, P. M.; Kuramitsu, Y.; Lamb, D. Q.; Lebedev, S.; Marques, J. R.; Miniati, F.; Morita, T.; Oliver, M.; Reville, B.; Sakawa, Y.; Sarkar, S.; Spindloe, C.; Trines, R.; Tzeferacos, P.; Silva, L. O.; Bingham, R.; Koenig, M.; Gregori, G.

    2018-05-01

    Astrophysical shocks are commonly revealed by the non-thermal emission of energetic electrons accelerated in situ1-3. Strong shocks are expected to accelerate particles to very high energies4-6; however, they require a source of particles with velocities fast enough to permit multiple shock crossings. While the resulting diffusive shock acceleration4 process can account for observations, the kinetic physics regulating the continuous injection of non-thermal particles is not well understood. Indeed, this injection problem is particularly acute for electrons, which rely on high-frequency plasma fluctuations to raise them above the thermal pool7,8. Here we show, using laboratory laser-produced shock experiments, that, in the presence of a strong magnetic field, significant electron pre-heating is achieved. We demonstrate that the key mechanism in producing these energetic electrons is through the generation of lower-hybrid turbulence via shock-reflected ions. Our experimental results are analogous to many astrophysical systems, including the interaction of a comet with the solar wind9, a setting where electron acceleration via lower-hybrid waves is possible.

  20. Current Fragmentation and Particle Acceleration in Solar Flares

    NASA Astrophysics Data System (ADS)

    Cargill, P. J.; Vlahos, L.; Baumann, G.; Drake, J. F.; Nordlund, Å.

    2012-11-01

    Particle acceleration in solar flares remains an outstanding problem in plasma physics and space science. While the observed particle energies and timescales can perhaps be understood in terms of acceleration at a simple current sheet or turbulence site, the vast number of accelerated particles, and the fraction of flare energy in them, defies any simple explanation. The nature of energy storage and dissipation in the global coronal magnetic field is essential for understanding flare acceleration. Scenarios where the coronal field is stressed by complex photospheric motions lead to the formation of multiple current sheets, rather than the single monolithic current sheet proposed by some. The currents sheets in turn can fragment into multiple, smaller dissipation sites. MHD, kinetic and cellular automata models are used to demonstrate this feature. Particle acceleration in this environment thus involves interaction with many distributed accelerators. A series of examples demonstrate how acceleration works in such an environment. As required, acceleration is fast, and relativistic energies are readily attained. It is also shown that accelerated particles do indeed interact with multiple acceleration sites. Test particle models also demonstrate that a large number of particles can be accelerated, with a significant fraction of the flare energy associated with them. However, in the absence of feedback, and with limited numerical resolution, these results need to be viewed with caution. Particle in cell models can incorporate feedback and in one scenario suggest that acceleration can be limited by the energetic particles reaching the condition for firehose marginal stability. Contemporary issues such as footpoint particle acceleration are also discussed. It is also noted that the idea of a "standard flare model" is ill-conceived when the entire distribution of flare energies is considered.

  1. Case of two electrostatics problems: Can providing a diagram adversely impact introductory physics students' problem solving performance?

    NASA Astrophysics Data System (ADS)

    Maries, Alexandru; Singh, Chandralekha

    2018-06-01

    Drawing appropriate diagrams is a useful problem solving heuristic that can transform a problem into a representation that is easier to exploit for solving it. One major focus while helping introductory physics students learn effective problem solving is to help them understand that drawing diagrams can facilitate problem solution. We conducted an investigation in which two different interventions were implemented during recitation quizzes in a large enrollment algebra-based introductory physics course. Students were either (i) asked to solve problems in which the diagrams were drawn for them or (ii) explicitly told to draw a diagram. A comparison group was not given any instruction regarding diagrams. We developed rubrics to score the problem solving performance of students in different intervention groups and investigated ten problems. We found that students who were provided diagrams never performed better and actually performed worse than the other students on three problems, one involving standing sound waves in a tube (discussed elsewhere) and two problems in electricity which we focus on here. These two problems were the only problems in electricity that involved considerations of initial and final conditions, which may partly account for why students provided with diagrams performed significantly worse than students who were not provided with diagrams. In order to explore potential reasons for this finding, we conducted interviews with students and found that some students provided with diagrams may have spent less time on the conceptual analysis and planning stage of the problem solving process. In particular, those provided with the diagram were more likely to jump into the implementation stage of problem solving early without fully analyzing and understanding the problem, which can increase the likelihood of mistakes in solutions.

  2. Unsolved problems. [the physics of B stars

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The level of understanding of the physics of single, isolated B stars is assessed and unresolved problems are defined. The significant observational results concerning the effective temperatures, radii, masses and mantles are summarized. The results of the theory of the evolution of massive stars are confronted with the observed luminosities and effective temperatures of B stars. In addition the implications of stellar spectra theory are compared with observed spectra and a heuristic model for a mantle is developed. The chief unresolved problems for B stars concern developing detailed models for (1) the internal structure of massive stars which are beginning to evolve rapidly as they complete burning hydrogen in their cores; (2) mantles; and (3) the transfer of radiation in high temperature inhomogeneous moving bodies of gas.

  3. Probing electron acceleration and x-ray emission in laser-plasma accelerators

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

    Thaury, C.; Ta Phuoc, K.; Corde, S.

    2013-06-15

    While laser-plasma accelerators have demonstrated a strong potential in the acceleration of electrons up to giga-electronvolt energies, few experimental tools for studying the acceleration physics have been developed. In this paper, we demonstrate a method for probing the acceleration process. A second laser beam, propagating perpendicular to the main beam, is focused on the gas jet few nanosecond before the main beam creates the accelerating plasma wave. This second beam is intense enough to ionize the gas and form a density depletion, which will locally inhibit the acceleration. The position of the density depletion is scanned along the interaction lengthmore » to probe the electron injection and acceleration, and the betatron X-ray emission. To illustrate the potential of the method, the variation of the injection position with the plasma density is studied.« less

  4. The Quantum Measurement Problem and Physical reality: A Computation Theoretic Perspective

    NASA Astrophysics Data System (ADS)

    Srikanth, R.

    2006-11-01

    Is the universe computable? If yes, is it computationally a polynomial place? In standard quantum mechanics, which permits infinite parallelism and the infinitely precise specification of states, a negative answer to both questions is not ruled out. On the other hand, empirical evidence suggests that NP-complete problems are intractable in the physical world. Likewise, computational problems known to be algorithmically uncomputable do not seem to be computable by any physical means. We suggest that this close correspondence between the efficiency and power of abstract algorithms on the one hand, and physical computers on the other, finds a natural explanation if the universe is assumed to be algorithmic; that is, that physical reality is the product of discrete sub-physical information processing equivalent to the actions of a probabilistic Turing machine. This assumption can be reconciled with the observed exponentiality of quantum systems at microscopic scales, and the consequent possibility of implementing Shor's quantum polynomial time algorithm at that scale, provided the degree of superposition is intrinsically, finitely upper-bounded. If this bound is associated with the quantum-classical divide (the Heisenberg cut), a natural resolution to the quantum measurement problem arises. From this viewpoint, macroscopic classicality is an evidence that the universe is in BPP, and both questions raised above receive affirmative answers. A recently proposed computational model of quantum measurement, which relates the Heisenberg cut to the discreteness of Hilbert space, is briefly discussed. A connection to quantum gravity is noted. Our results are compatible with the philosophy that mathematical truths are independent of the laws of physics.

  5. Centripetal Acceleration: Often Forgotten or Misinterpreted

    ERIC Educational Resources Information Center

    Singh, Chandralekha

    2009-01-01

    Acceleration is a fundamental concept in physics which is taught in mechanics at all levels. Here, we discuss some challenges in teaching this concept effectively when the path along which the object is moving has a curvature and centripetal acceleration is present. We discuss examples illustrating that both physics teachers and students have…

  6. Physical health problems among patients seeking treatment for alcohol use disorders: a study in six European cities.

    PubMed

    Gossop, Michael; Neto, Domingos; Radovanovic, Mirjana; Batra, Anil; Toteva, Sonya; Musalek, Michael; Skutle, Arvid; Goos, Cees

    2007-06-01

    The present study investigates physical health problems among patients with alcohol use disorders at alcohol treatment agencies in six European cities. The sample comprised 315 patients with a primary alcohol use disorder. Data were collected at admission to treatment using a structured research protocol, and ratings were made by a medically qualified physician subsequent to a physical examination of the patient. Physical health problems were extremely common: 79% of the sample had at least one problem, and 59% had two or more problems. Health problems were often serious, and 60% had at least one health problem that required treatment. The most common problems were gastrointestinal and liver disorders, but about a quarter of the sample had cardiovascular or neurological problems. Frequency of drinking, duration of alcohol use disorder, and severity of alcohol dependence were associated with increased physical morbidity. Current smoking status and age were also associated with poorer physical health. Older drinkers had more physical health problems although they were less severely alcohol dependent than their younger counterparts. The high prevalence of physical health problems among problem drinkers provides opportunities of screening for alcohol use disorders not only in specialist alcohol treatment services but also in other health-care settings. It is recommended that alcohol treatment agencies should provide a full routine health screen of patients at admission to treatment with provision or referral to appropriate treatment.

  7. The history and future of accelerator radiological protection.

    PubMed

    Thomas, R H

    2001-01-01

    The development of accelerator radiological protection from the mid-1930s, just after the invention of the cyclotron, to the present day is described. Three major themes--physics, personalities and politics--are developed. In the sections describing physics the development of shielding design though measurement, radiation transport calculations, the impact of accelerators on the environment and dosimetry in accelerator radiation fields are described. The discussion is limited to high-energy, high-intensity electron and proton accelerators. The impact of notable personalities on the development of both the basic science and on the accelerator health physics profession itself is described. The important role played by scholars and teachers is discussed. In the final section. which discusses the future of accelerator radiological protection, some emphasis is given to the social and political aspects that must he faced in the years ahead.

  8. 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…

  9. Learning problem-solving skills in a distance education physics course

    NASA Astrophysics Data System (ADS)

    Rampho, G. J.; Ramorola, M. Z.

    2017-10-01

    In this paper we present the results of a study on the effectiveness of combinations of delivery modes of distance education in learning problem-solving skills in a distance education introductory physics course. A problem-solving instruction with the explicit teaching of a problem-solving strategy and worked-out examples were implemented in the course. The study used the ex post facto research design with stratified sampling to investigate the effect of the learning of a problem-solving strategy on the problem-solving performance. The number of problems attempted and the mean frequency of using a strategy in solving problems in the three course presentation modes were compared. The finding of the study indicated that combining the different course presentation modes had no statistically significant effect in the learning of problem-solving skills in the distance education course.

  10. 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

  11. 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.

  12. 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…

  13. Diversity of Approaches to Problems by Students Enrolled in a Non-Calculus College Physics Course.

    ERIC Educational Resources Information Center

    Cohen, Anna Foner

    This study was undertaken to determine whether hierarchically structured problem situations could be developed and used to identify where individual solutions to problems in elementary physics are interrupted and whether examination of student approaches to problem situations would be useful to physics teaching. A random sample of 26 students…

  14. Behavior Problems in School-Aged Physically Abused and Neglected Children in Spain.

    ERIC Educational Resources Information Center

    de Paul, Joaquin; Arruabarrena, M. Ignacia

    1995-01-01

    This study investigated behavior problems in 66 school-aged physically abused, neglected, and control group children in the Basque Country, Spain. Abused and neglected children had higher subscale scores for social problems, delinquent behavior, and attention problems and showed lower school adjustment. Neglected children appeared more aggressive,…

  15. Accelerator Technology Division annual report, FY 1989

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

    Not Available

    1990-06-01

    This paper discusses: accelerator physics and special projects; experiments and injectors; magnetic optics and beam diagnostics; accelerator design and engineering; radio-frequency technology; accelerator theory and simulation; free-electron laser technology; accelerator controls and automation; and high power microwave sources and effects.

  16. High Gradient Accelerator Research

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

    Temkin, Richard

    The goal of the MIT program of research on high gradient acceleration is the development of advanced acceleration concepts that lead to a practical and affordable next generation linear collider at the TeV energy level. Other applications, which are more near-term, include accelerators for materials processing; medicine; defense; mining; security; and inspection. The specific goals of the MIT program are: • Pioneering theoretical research on advanced structures for high gradient acceleration, including photonic structures and metamaterial structures; evaluation of the wakefields in these advanced structures • Experimental research to demonstrate the properties of advanced structures both in low-power microwave coldmore » test and high-power, high-gradient test at megawatt power levels • Experimental research on microwave breakdown at high gradient including studies of breakdown phenomena induced by RF electric fields and RF magnetic fields; development of new diagnostics of the breakdown process • Theoretical research on the physics and engineering features of RF vacuum breakdown • Maintaining and improving the Haimson / MIT 17 GHz accelerator, the highest frequency operational accelerator in the world, a unique facility for accelerator research • Providing the Haimson / MIT 17 GHz accelerator facility as a facility for outside users • Active participation in the US DOE program of High Gradient Collaboration, including joint work with SLAC and with Los Alamos National Laboratory; participation of MIT students in research at the national laboratories • Training the next generation of Ph. D. students in the field of accelerator physics.« less

  17. Dark Energy: A Crisis for Fundamental Physics

    ScienceCinema

    Stubbs, Christopher [Harvard University, Cambridge, Massachusetts, USA

    2017-12-09

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talk will present experiments and observations that are exploring this issue.

  18. REVIEWS OF TOPICAL PROBLEMS: Application of cybernetic methods in physics

    NASA Astrophysics Data System (ADS)

    Fradkov, Aleksandr L.

    2005-02-01

    Basic aspects of the subject and methodology for a new and rapidly developing area of research that has emerged at the intersection of physics and control theory (cybernetics) and emphasizes the application of cybernetic methods to the study of physical systems are reviewed. Speed-gradient and Hamiltonian solutions for energy control problems in conservative and dissipative systems are presented. Application examples such as the Kapitza pendulum, controlled overcoming of a potential barrier, and controlling coupled oscillators and molecular systems are presented. A speed-gradient approach to modeling the dynamics of physical systems is discussed.

  19. Project Physics Tests 1, Concepts of Motion.

    ERIC Educational Resources Information Center

    Harvard Univ., Cambridge, MA. Harvard Project Physics.

    Test items relating to Project Physics Unit 1 are presented in this booklet, consisting of 70 multiple-choice and 20 problem-and-essay questions. Concepts of motion are examined with respect to velocities, acceleration, forces, vectors, Newton's laws, and circular motion. Suggestions are made for time consumption in answering some items. Besides…

  20. Accelerator-based Neutrino Physics at Fermilab

    NASA Astrophysics Data System (ADS)

    Dukes, Edmond

    2008-10-01

    The discovery of neutrino mass has excited great interest in elucidating the properties of neutrinos and their role in nature. Experiments around the world take advantage of solar, atmospheric, reactor, and accelerator sources of neutrinos. Accelerator-based sources are particularly convenient since their parameters can be tuned to optimize the measurement in question. At Fermilab an extensive neutrino program includes the MiniBooNE, SciBooNE, and MINOS experiments. Two major new experiments, MINERvA and NOvA, are being constructed, plans for a high-intensity neutrino source to DUSEL are underway, and an R&D effort towards a large liquid argon detector is being pursued. The NOvA experiment intends to search for electron neutrino appearance using a massive surface detector 811 km from Fermilab. In addition to measuring the last unknown mixing angle, theta(13), NOvA has the possibility of seeing matter-antimatter asymmetries in neutrinos and resolving the ordering of the neutrino mass states.

  1. Students' conceptual performance on synthesis physics problems with varying mathematical complexity

    NASA Astrophysics Data System (ADS)

    Ibrahim, Bashirah; Ding, Lin; Heckler, Andrew F.; White, Daniel R.; Badeau, Ryan

    2017-06-01

    A body of research on physics problem solving has focused on single-concept problems. In this study we use "synthesis problems" that involve multiple concepts typically taught in different chapters. We use two types of synthesis problems, sequential and simultaneous synthesis tasks. Sequential problems require a consecutive application of fundamental principles, and simultaneous problems require a concurrent application of pertinent concepts. We explore students' conceptual performance when they solve quantitative synthesis problems with varying mathematical complexity. Conceptual performance refers to the identification, follow-up, and correct application of the pertinent concepts. Mathematical complexity is determined by the type and the number of equations to be manipulated concurrently due to the number of unknowns in each equation. Data were collected from written tasks and individual interviews administered to physics major students (N =179 ) enrolled in a second year mechanics course. The results indicate that mathematical complexity does not impact students' conceptual performance on the sequential tasks. In contrast, for the simultaneous problems, mathematical complexity negatively influences the students' conceptual performance. This difference may be explained by the students' familiarity with and confidence in particular concepts coupled with cognitive load associated with manipulating complex quantitative equations. Another explanation pertains to the type of synthesis problems, either sequential or simultaneous task. The students split the situation presented in the sequential synthesis tasks into segments but treated the situation in the simultaneous synthesis tasks as a single event.

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

    NASA Astrophysics Data System (ADS)

    Gollub, Jerry

    2003-04-01

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

  3. The effectiveness of collaborative problem based physics learning (CPBPL) model to improve student’s self-confidence on physics learning

    NASA Astrophysics Data System (ADS)

    Prahani, B. K.; Suprapto, N.; Suliyanah; Lestari, N. A.; Jauhariyah, M. N. R.; Admoko, S.; Wahyuni, S.

    2018-03-01

    In the previous research, Collaborative Problem Based Physic Learning (CPBPL) model has been developed to improve student’s science process skills, collaborative problem solving, and self-confidence on physics learning. This research is aimed to analyze the effectiveness of CPBPL model towards the improvement of student’s self-confidence on physics learning. This research implemented quasi experimental design on 140 senior high school students who were divided into 4 groups. Data collection was conducted through questionnaire, observation, and interview. Self-confidence measurement was conducted through Self-Confidence Evaluation Sheet (SCES). The data was analyzed using Wilcoxon test, n-gain, and Kruskal Wallis test. Result shows that: (1) There is a significant score improvement on student’s self-confidence on physics learning (α=5%), (2) n-gain value student’s self-confidence on physics learning is high, and (3) n-gain average student’s self-confidence on physics learning was consistent throughout all groups. It can be concluded that CPBPL model is effective to improve student’s self-confidence on physics learning.

  4. Measurement of Coriolis Acceleration with a Smartphone

    ERIC Educational Resources Information Center

    Shaku, Asif; Kraft, Jakob

    2016-01-01

    Undergraduate physics laboratories seldom have experiments that measure the Coriolis acceleration. This has traditionally been the case owing to the inherent complexities of making such measurements. Articles on the experimental determination of the Coriolis acceleration are few and far between in the physics literature. However, because modern…

  5. Cosmic acceleration in the nonlocal approach to the cosmological constant problem

    NASA Astrophysics Data System (ADS)

    Oda, Ichiro

    2018-04-01

    We have recently constructed a manifestly local formulation of a nonlocal approach to the cosmological constant problem which can treat with quantum effects from both matter and gravitational fields. In this formulation, it has been explicitly shown that the effective cosmological constant is radiatively stable even in the presence of the gravitational loop effects. Since we are naturally led to add the R^2 term and the corresponding topological action to an original action, we make use of this formulation to account for the late-time acceleration of expansion of the universe in case of the open universes with infinite space-time volume. We will see that when the "scalaron", which exists in the R^2 gravity as an extra scalar field, has a tiny mass of the order of magnitude {O}(1 meV), we can explain the current value of the cosmological constant in a consistent manner.

  6. 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…

  7. Personifying self in physics problem situations involving forces as a student help strategy

    NASA Astrophysics Data System (ADS)

    Tabor-Morris, A. E.

    2013-03-01

    How can physics teachers best guide students regarding physics problem situations involving forces? A suggestion is made here to personify oneself as the object in question, that is, to pretend to be the object undergoing forces and then qualify and quantify those forces according to their vectors for the system at hand. This personification is not meant to empower the object to act, just to sense the forces it is experiencing. This strategy may be especially useful to beginning physics learners attacking problems that involve both multiple forces AND multiple objects, since each object acted upon needs to be considered separately, using the idea that one cannot be two places at once. An example of this type of problem expounded on here is Atwood's machine: two weights hung over a pulley with a single rope. Another example given is electromagnetic forces on one charge caused by other charges in the vicinity. Discussion is made on implementation of classroom strategies. Department of Physics

  8. Students Problem-Solving Difficulties and Implications in Physics: An Empirical Study on Influencing Factors

    ERIC Educational Resources Information Center

    Reddy, M. Vijaya Bhaskara; Panacharoensawad, Buncha

    2017-01-01

    In twenty first century, abundant innovative tools have been identified by the researchers to evaluate the conceptual understandings, problem solving, beliefs and attitudes about physics. Nevertheless, lacking of wide variety of evaluation instruments with respect to problem solving in physics. It indicates that the complexity of the domain fields…

  9. Accelerators Beyond The Tevatron?

    NASA Astrophysics Data System (ADS)

    Lach, Joseph

    2010-07-01

    Following the successful operation of the Fermilab superconducting accelerator three new higher energy accelerators were planned. They were the UNK in the Soviet Union, the LHC in Europe, and the SSC in the United States. All were expected to start producing physics about 1995. They did not. Why?.

  10. 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…

  11. 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.

  12. 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

  13. 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 in the…

  14. 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.

  15. Accelerated Educational Change; The Annual Western Regional Conference on Testing Problems (15th, San Francisco, California, May 6, 1966).

    ERIC Educational Resources Information Center

    Educational Testing Service, Princeton, NJ.

    The 1966 meeting of the Western Regional Conference on Testing Problems dealt with accelerated educational change. The following speeches were presented: (1) "Access to Higher Education: Implications for Future Planning" by Richard Pearson; (2) "The Differentiated Youth: A Challenge to Traditional Institutions" by Joseph D. Lohman; (3) "Teaching…

  16. Detailed Modeling of Physical Processes in Electron Sources for Accelerator Applications

    NASA Astrophysics Data System (ADS)

    Chubenko, Oksana; Afanasev, Andrei

    2017-01-01

    At present, electron sources are essential in a wide range of applications - from common technical use to exploring the nature of matter. Depending on the application requirements, different methods and materials are used to generate electrons. State-of-the-art accelerator applications set a number of often-conflicting requirements for electron sources (e.g., quantum efficiency vs. polarization, current density vs. lifetime, etc). Development of advanced electron sources includes modeling and design of cathodes, material growth, fabrication of cathodes, and cathode testing. The detailed simulation and modeling of physical processes is required in order to shed light on the exact mechanisms of electron emission and to develop new-generation electron sources with optimized efficiency. The purpose of the present work is to study physical processes in advanced electron sources and develop scientific tools, which could be used to predict electron emission from novel nano-structured materials. In particular, the area of interest includes bulk/superlattice gallium arsenide (bulk/SL GaAs) photo-emitters and nitrogen-incorporated ultrananocrystalline diamond ((N)UNCD) photo/field-emitters. Work supported by The George Washington University and Euclid TechLabs LLC.

  17. Abraham Pais Prize Lecture: Shifting Problems and Boundaries in the History of Modern Physics

    NASA Astrophysics Data System (ADS)

    Nye, Mary-Jo

    A long established category of study in the history of science is the ``history of physical sciences.'' It is a category that immediately begs the question of disciplinary boundaries for the problems and subjects addressed in historical inquiry. As a historian of the physical sciences, I often have puzzled over disciplinary boundaries and the means used to create or justify them. Scientists most often have been professionally identified with specific institutionalized fields since the late 19th century, but the questions they ask and the problems they solve are not neatly carved up by disciplinary perimeters. Like institutional departments or professorships, the Nobel Prizes in the 20th century often have delineated the scope of ``Physics'' or ``Chemistry'' (and ``Physiology or Medicine''), but the Prizes do not reflect disciplinary rigidity, despite some standard core subjects. In this paper I examine trends in Nobel Prize awards that indicate shifts in problem solving and in boundaries in twentieth century physics, tying those developments to changing themes in the history of physics and physical science in recent decades.

  18. Physically Abused Women’s Experiences of Sexual Victimization and their Children’s Disruptive Behavior Problems

    PubMed Central

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

    2012-01-01

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

  19. Maxwell-Faraday Stresses in Electromagnetic Fields and the Self-Force on a Uniformly Accelerating Point Charge

    ERIC Educational Resources Information Center

    Rowland, D. R.

    2007-01-01

    The physical analysis of a uniformly accelerating point charge provides a rich problem to explore in advanced courses in electrodynamics and relativity since it brings together fundamental concepts in relation to electromagnetic radiation, Einstein's equivalence principle and the inertial mass of field energy in ways that reveal subtleties in each…

  20. Do New Caledonian crows solve physical problems through causal reasoning?

    PubMed Central

    Taylor, A.H.; Hunt, G.R.; Medina, F.S.; Gray, R.D.

    2008-01-01

    The extent to which animals other than humans can reason about physical problems is contentious. The benchmark test for this ability has been the trap-tube task. We presented New Caledonian crows with a series of two-trap versions of this problem. Three out of six crows solved the initial trap-tube. These crows continued to avoid the trap when the arbitrary features that had previously been associated with successful performances were removed. However, they did not avoid the trap when a hole and a functional trap were in the tube. In contrast to a recent primate study, the three crows then solved a causally equivalent but visually distinct problem—the trap-table task. The performance of the three crows across the four transfers made explanations based on chance, associative learning, visual and tactile generalization, and previous dispositions unlikely. Our findings suggest that New Caledonian crows can solve complex physical problems by reasoning both causally and analogically about causal relations. Causal and analogical reasoning may form the basis of the New Caledonian crow's exceptional tool skills. PMID:18796393

  1. Block-accelerated aggregation multigrid for Markov chains with application to PageRank problems

    NASA Astrophysics Data System (ADS)

    Shen, Zhao-Li; Huang, Ting-Zhu; Carpentieri, Bruno; Wen, Chun; Gu, Xian-Ming

    2018-06-01

    Recently, the adaptive algebraic aggregation multigrid method has been proposed for computing stationary distributions of Markov chains. This method updates aggregates on every iterative cycle to keep high accuracies of coarse-level corrections. Accordingly, its fast convergence rate is well guaranteed, but often a large proportion of time is cost by aggregation processes. In this paper, we show that the aggregates on each level in this method can be utilized to transfer the probability equation of that level into a block linear system. Then we propose a Block-Jacobi relaxation that deals with the block system on each level to smooth error. Some theoretical analysis of this technique is presented, meanwhile it is also adapted to solve PageRank problems. The purpose of this technique is to accelerate the adaptive aggregation multigrid method and its variants for solving Markov chains and PageRank problems. It also attempts to shed some light on new solutions for making aggregation processes more cost-effective for aggregation multigrid methods. Numerical experiments are presented to illustrate the effectiveness of this technique.

  2. 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…

  3. Conceptual design project: Accelerator complex for nuclear physics studies and boron neutron capture therapy application at the Yerevan Physics Institute (YerPhI) Yerevan, Armenia

    NASA Astrophysics Data System (ADS)

    Avagyan, R. H.; Kerobyan, I. A.

    2015-07-01

    The final goal of the proposed project is the creation of a Complex of Accelerator Facilities at the Yerevan Physics Institute (CAF YerPhI) for nuclear physics basic researches, as well as for applied programs including boron neutron capture therapy (BNCT). The CAF will include the following facilities: Cyclotron C70, heavy material (uranium) target/ion source, mass-separator, LINAC1 (0.15-1.5 MeV/u) and LINAC2 (1.5-10 MeV/u). The delivered by C70 proton beams with energy 70 MeV will be used for investigations in the field of basic nuclear physics and with energy 30 MeV for use in applications.

  4. Physics Teachers' Education (PTE): Problems and Challenges

    NASA Astrophysics Data System (ADS)

    Sassi, Elena; Michelini, Marisa

    A vast majority of the research results acknowledge the crucial role of teacher's education, as a vital tool in enhancing the quality of physics education. The projects like PISA, ROSE and TIMMS showcase the impact of teacher's education as a qualitative improvement in the physics learning environment. In Physics Education Research (PER), the impact of teacher's education had been addressed for the its role in the enhancement of positive interest among the students. The current world-wide state of the art characterizes a large variety of boundary conditions, traditions and practices that are being followed. In our present context, we foucus and discuss on the multidimensional challanges such as competencies needed, degrees required, problems encountered, support to be provided and the basic pre-requirements of Teacher's education for the secondary schools. We present some of the teaching methods and practices followed in coherent with, both, the Student centered and open learning environments along with some of the useful didactical indicators. Also, we potray a couple of research-based examples successfully experimented in Italy. Finally we propose some useful recommendations along with the criteria to be followed in the teachers education for the overall improvement.

  5. 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…

  6. The profile of students’ problem-solving skill in physics across interest program in the secondary school

    NASA Astrophysics Data System (ADS)

    Jua, S. K.; Sarwanto; Sukarmin

    2018-05-01

    Problem-solving skills are important skills in physics. However, according to some researchers, the problem-solving skill of Indonesian students’ problem in physics learning is categorized still low. The purpose of this study was to identify the profile of problem-solving skills of students who follow the across the interests program of physics. The subjects of the study were high school students of Social Sciences, grade X. The type of this research was descriptive research. The data which used to analyze the problem-solving skills were obtained through student questionnaires and the test results with impulse materials and collision. From the descriptive analysis results, the percentage of students’ problem-solving skill based on the test was 52.93% and indicators respectively. These results indicated that students’ problem-solving skill is categorized low.

  7. 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…

  8. Attention and Encoding in Physics Learning and Problem Solving

    ERIC Educational Resources Information Center

    Feil, Adam John

    2009-01-01

    This dissertation presents several studies designed to probe the mental representations that physics experts and novices form when interacting with typical instructional materials, such as diagrams and problem statements. By using recognition tasks and a change detection task, the mental representations of experts and novices are studied in a more…

  9. Electronic collection of solved physics problems to encourage students’ active approach (not only to self study)

    NASA Astrophysics Data System (ADS)

    Koupilová, Zdeňka; Mandíková, Dana; Snětinová, Marie

    2017-09-01

    Ten years ago we started to develop a Collection of Fully Solved Problems aimed at introductory undergraduate and high school level students. The collection is specially designed to encourage students in an active approach to problem solving, e.g. to solve at least some parts of a problem on their own. Nowadays the Collection contains about 800 fully solved problems in physics in Czech and nearly 180 problems in English. It has several hundreds of unique visitors per school day. Based on user feedback, the collection is used by students mainly for their home study and by teachers as a supplementary material. The creation of the structured solution of the physics problems has proved to be a beneficial activity for prospective physics teachers (students of our department).

  10. 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.

  11. Multi-GPU Jacobian accelerated computing for soft-field tomography.

    PubMed

    Borsic, A; Attardo, E A; Halter, R J

    2012-10-01

    Image reconstruction in soft-field tomography is based on an inverse problem formulation, where a forward model is fitted to the data. In medical applications, where the anatomy presents complex shapes, it is common to use finite element models (FEMs) to represent the volume of interest and solve a partial differential equation that models the physics of the system. Over the last decade, there has been a shifting interest from 2D modeling to 3D modeling, as the underlying physics of most problems are 3D. Although the increased computational power of modern computers allows working with much larger FEM models, the computational time required to reconstruct 3D images on a fine 3D FEM model can be significant, on the order of hours. For example, in electrical impedance tomography (EIT) applications using a dense 3D FEM mesh with half a million elements, a single reconstruction iteration takes approximately 15-20 min with optimized routines running on a modern multi-core PC. It is desirable to accelerate image reconstruction to enable researchers to more easily and rapidly explore data and reconstruction parameters. Furthermore, providing high-speed reconstructions is essential for some promising clinical application of EIT. For 3D problems, 70% of the computing time is spent building the Jacobian matrix, and 25% of the time in forward solving. In this work, we focus on accelerating the Jacobian computation by using single and multiple GPUs. First, we discuss an optimized implementation on a modern multi-core PC architecture and show how computing time is bounded by the CPU-to-memory bandwidth; this factor limits the rate at which data can be fetched by the CPU. Gains associated with the use of multiple CPU cores are minimal, since data operands cannot be fetched fast enough to saturate the processing power of even a single CPU core. GPUs have much faster memory bandwidths compared to CPUs and better parallelism. We are able to obtain acceleration factors of 20

  12. Multi-GPU Jacobian Accelerated Computing for Soft Field Tomography

    PubMed Central

    Borsic, A.; Attardo, E. A.; Halter, R. J.

    2012-01-01

    Image reconstruction in soft-field tomography is based on an inverse problem formulation, where a forward model is fitted to the data. In medical applications, where the anatomy presents complex shapes, it is common to use Finite Element Models to represent the volume of interest and to solve a partial differential equation that models the physics of the system. Over the last decade, there has been a shifting interest from 2D modeling to 3D modeling, as the underlying physics of most problems are three-dimensional. Though the increased computational power of modern computers allows working with much larger FEM models, the computational time required to reconstruct 3D images on a fine 3D FEM model can be significant, on the order of hours. For example, in Electrical Impedance Tomography applications using a dense 3D FEM mesh with half a million elements, a single reconstruction iteration takes approximately 15 to 20 minutes with optimized routines running on a modern multi-core PC. It is desirable to accelerate image reconstruction to enable researchers to more easily and rapidly explore data and reconstruction parameters. Further, providing high-speed reconstructions are essential for some promising clinical application of EIT. For 3D problems 70% of the computing time is spent building the Jacobian matrix, and 25% of the time in forward solving. In the present work, we focus on accelerating the Jacobian computation by using single and multiple GPUs. First, we discuss an optimized implementation on a modern multi-core PC architecture and show how computing time is bounded by the CPU-to-memory bandwidth; this factor limits the rate at which data can be fetched by the CPU. Gains associated with use of multiple CPU cores are minimal, since data operands cannot be fetched fast enough to saturate the processing power of even a single CPU core. GPUs have a much faster memory bandwidths compared to CPUs and better parallelism. We are able to obtain acceleration factors of

  13. Beam acceleration through proton radio frequency quadrupole accelerator in BARC

    NASA Astrophysics Data System (ADS)

    Bhagwat, P. V.; Krishnagopal, S.; Mathew, J. V.; Singh, S. K.; Jain, P.; Rao, S. V. L. S.; Pande, M.; Kumar, R.; Roychowdhury, P.; Kelwani, H.; Rama Rao, B. V.; Gupta, S. K.; Agarwal, A.; Kukreti, B. M.; Singh, P.

    2016-05-01

    A 3 MeV proton Radio Frequency Quadrupole (RFQ) accelerator has been designed at the Bhabha Atomic Research Centre, Mumbai, India, for the Low Energy High Intensity Proton Accelerator (LEHIPA) programme. The 352 MHz RFQ is built in 4 segments and in the first phase two segments of the LEHIPA RFQ were commissioned, accelerating a 50 keV, 1 mA pulsed proton beam from the ion source, to an energy of 1.24 MeV. The successful operation of the RFQ gave confidence in the physics understanding and technology development that have been achieved, and indicate that the road forward can now be traversed rather more quickly.

  14. Dark Energy: A Crisis for Fundamental Physics

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

    Stubbs, Christopher

    2010-04-12

    Astrophysical observations provide robust evidence that our current picture of fundamental physics is incomplete. The discovery in 1998 that the expansion of the Universe is accelerating (apparently due to gravitational repulsion between regions of empty space!) presents us with a profound challenge, at the interface between gravity and quantum mechanics. This "Dark Energy" problem is arguably the most pressing open question in modern fundamental physics. The first talk will describe why the Dark Energy problem constitutes a crisis, with wide-reaching ramifications. One consequence is that we should probe our understanding of gravity at all accessible scales, and the second talkmore » will present experiments and observations that are exploring this issue.« less

  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. Behavior problems in school-aged physically abused and neglected children in Spain.

    PubMed

    de Paúl, J; Arruabarrena, M I

    1995-04-01

    The present study investigated behavior problems in school-aged physically abused, neglected, and comparison children in the Basque Country (Spain). Data from the Teacher's Report Form of the Child Behavior Checklist was obtained on 66 children consisting of three groups (17 physically abused children, 24 physically neglected children, and 25 low-risk comparison children). The three groups were matched on seven sociodemographic variables. Overall, the abused and neglected children were higher than the comparison group on Total Behavior Problems scores. However, only neglected children obtained higher scores than the comparison group on the total score of the Externalized Scale, and only abused children scored higher than the comparison group on the total score of the Internalized Scale. Follow-up analysis indicated that both abused and neglected children had higher scores on the Social Problems, Delinquent Behavior, and Attention Problems subscales. Moreover, neglected children had higher scores on the Aggressive Behavior subscale than the comparison children, and abused children had higher scores on the Withdrawn subscale than the comparison children. The abused and neglected children also showed a lower school adjustment than the comparison group. Possible explanations of these findings are discussed and their implications for research and treatment are considered.

  17. 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 this…

  18. 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…

  19. 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…

  20. Electron Accelerators for Research at the Frontiers of Nuclear Physics

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

    Hartline, Beverly; Grunder, Hermann

    1986-10-01

    Electron accelerators for the frontiers of nuclear physics must provide high duty factor (gte 80) for coincidence measurements; few-hundred-MeV through few-GeV energy for work in the nucleonic, hadronic, and confinement regimes; energy resolution of ~ 10 -4; and high current (gte 100 zA). To fulfill these requirements new machines and upgrades of existing ones are being planned or constructed. Representative microtron-based facilities are the upgrade of MAMI at the University of Mainz (West Germany), the proposed two-stage cascade microtron at the University of Illinois (U.S.A.), and the three-stage Troitsk ``polytron'' (USSR). Representative projects to add pulse stretcher rings to existingmore » linacs are the upgrades at MIT-Bates (U.S.A.) and at NIKHEF-K (Netherlands). Recent advances in superconducting rf technology, especially in cavity design and fabrication, have made large superconducting cw linacs become feasible. Recirculating superconducting cw linacs are under construc« less

  1. 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…

  2. 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…

  3. 1985 Particle Accelerator Conference: Accelerator Engineering and Technology, 11th, Vancouver, Canada, May 13-16, 1985, Proceedings

    NASA Astrophysics Data System (ADS)

    Strathdee, A.

    1985-10-01

    The topics discussed are related to high-energy accelerators and colliders, particle sources and electrostatic accelerators, controls, instrumentation and feedback, beam dynamics, low- and intermediate-energy circular accelerators and rings, RF and other acceleration systems, beam injection, extraction and transport, operations and safety, linear accelerators, applications of accelerators, radiation sources, superconducting supercolliders, new acceleration techniques, superconducting components, cryogenics, and vacuum. Accelerator and storage ring control systems are considered along with linear and nonlinear orbit theory, transverse and longitudinal instabilities and cures, beam cooling, injection and extraction orbit theory, high current dynamics, general beam dynamics, and medical and radioisotope applications. Attention is given to superconducting RF structures, magnet technology, superconducting magnets, and physics opportunities with relativistic heavy ion accelerators.

  4. Age-related physical and psychological vulnerability as pathways to problem gambling in older adults.

    PubMed

    Parke, Adrian; Griffiths, Mark; Pattinson, Julie; Keatley, David

    2018-03-01

    Background To inform clinical treatment and preventative efforts, there is an important need to understand the pathways to late-life gambling disorder. Aims This study assesses the association between age-related physical health, social networks, and problem gambling in adults aged over 65 years and assesses the mediating role of affective disorders in this association. Methods The sample comprised 595 older adults (mean age: 74.4 years, range: 65-94 years; 77.1% female) who were interviewed using a structured questionnaire to assess physical frailty, geriatric pain, loneliness, geriatric depression, geriatric anxiety, and problem gambling. Results Pathway analysis demonstrated associations between these variables and gambling problems, providing a good fit for the data, but that critically these relationships were mediated by both anxiety and depression symptoms. Conclusions This study indicates that late-life problem gambling may develop as vulnerable individuals gamble to escape anxiety and depression consequent to deteriorating physical well-being and social support. When individuals develop late-life problem gambling, it is recommended that the treatment primarily focuses upon targeting and replacing avoidant coping approaches.

  5. ON THE PROBLEM OF PARTICLE GROUPINGS IN A TRAVELING WAVE LINEAR ACCELERATOR

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

    Zhileyko, G.I.

    1957-01-01

    A linear accelerator with traveling'' waves may be used for the production of especially short electron momenta, although in many cases the grouping capacity of the accelerator is not sufficient. Theoretically the case is derived in which grouping of the electrons takes place in the accelerator itself. (With 3 illustrations and 1 Slavic Reference). (TCO)

  6. Illinois Accelerator Research Center

    DOE PAGES

    Kroc, Thomas K.; Cooper, Charlie A.

    2017-10-26

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 heavy assembly building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, whichmore » contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. Finally, at IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.« less

  7. Illinois Accelerator Research Center

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

    Kroc, Thomas K.; Cooper, Charlie A.

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 heavy assembly building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, whichmore » contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. Finally, at IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.« less

  8. Illinois Accelerator Research Center

    NASA Astrophysics Data System (ADS)

    Kroc, Thomas K.; Cooper, Charlie A.

    The Illinois Accelerator Research Center (IARC) hosts a new accelerator development program at Fermi National Accelerator Laboratory. IARC provides access to Fermi's state-of-the-art facilities and technologies for research, development and industrialization of particle accelerator technology. In addition to facilitating access to available existing Fermi infrastructure, the IARC Campus has a dedicated 36,000 ft2 Heavy Assembly Building (HAB) with all the infrastructure needed to develop, commission and operate new accelerators. Connected to the HAB is a 47,000 ft2 Office, Technology and Engineering (OTE) building, paid for by the state, that has office, meeting, and light technical space. The OTE building, which contains the Accelerator Physics Center, and nearby Accelerator and Technical divisions provide IARC collaborators with unique access to world class expertise in a wide array of accelerator technologies. At IARC scientists and engineers from Fermilab and academia work side by side with industrial partners to develop breakthroughs in accelerator science and translate them into applications for the nation's health, wealth and security.

  9. 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…

  10. Examining End-of-Chapter Problems across Editions of an Introductory Calculus-Based Physics Textbook

    ERIC Educational Resources Information Center

    Xiao, Bin

    2016-01-01

    End-Of-Chapter (EOC) problems have been part of many physics education studies. Typically, only problems "localized" as relevant to a single chapter were used. This work examines how well this type of problem represents all EOC problems and whether EOC problems found in leading textbooks have changed over the past several decades. To…

  11. Measurement of Coriolis Acceleration with a Smartphone

    NASA Astrophysics Data System (ADS)

    Shakur, Asif; Kraft, Jakob

    2016-05-01

    Undergraduate physics laboratories seldom have experiments that measure the Coriolis acceleration. This has traditionally been the case owing to the inherent complexities of making such measurements. Articles on the experimental determination of the Coriolis acceleration are few and far between in the physics literature. However, because modern smartphones come with a raft of built-in sensors, we have a unique opportunity to experimentally determine the Coriolis acceleration conveniently in a pedagogically enlightening environment at modest cost by using student-owned smartphones. Here we employ the gyroscope and accelerometer in a smartphone to verify the dependence of Coriolis acceleration on the angular velocity of a rotatingtrack and the speed of the sliding smartphone.

  12. 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.

  13. Maternal depression and physical health problems in early pregnancy: findings of an Australian nulliparous pregnancy cohort study.

    PubMed

    Perlen, Susan; Woolhouse, Hannah; Gartland, Deirdre; Brown, Stephanie J

    2013-03-01

    to investigate the relationship between physical health problems and depressive symptoms in early pregnancy. baseline questionnaire, prospective pregnancy cohort study. six metropolitan public maternity hospitals in Victoria, Australia. 1507 nulliparous women recruited in early pregnancy. nine per cent of women (131/1500) scored ≥ 13 on the EPDS indicating probable clinical depression in early pregnancy (mean gestation=15 weeks). The five most commonly reported physical health problems were as follows: exhaustion (86.9%), morning sickness (64.3%), back pain (45.6%), constipation (43.5%) and severe headaches or migraines (29.5%). Women scoring ≥ 13 on the EPDS reported a mean of six physical health problems compared with a mean of 3.5 among women scoring <13 on the EPDS. Women reporting five or more physical health problems had a three-fold increase in likelihood of reporting depressive symptoms (Adj OR=3.13, 95% CI 2.14-4.58) after adjusting for socio-demographic factors, including maternal age. the findings from this large multi-centre study show that women experiencing a greater number of physical health problems are at increased risk of reporting depressive symptoms in early pregnancy. early detection and support for women experiencing physical and psychological health problems in pregnancy is an important aspect of antenatal care. The extent of co-morbid physical and psychological health problems underlines the need for comprehensive primary health care as an integral component of antenatal care. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. A test harness for accelerating physics parameterization advancements into operations

    NASA Astrophysics Data System (ADS)

    Firl, G. J.; Bernardet, L.; Harrold, M.; Henderson, J.; Wolff, J.; Zhang, M.

    2017-12-01

    The process of transitioning advances in parameterization of sub-grid scale processes from initial idea to implementation is often much quicker than the transition from implementation to use in an operational setting. After all, considerable work must be undertaken by operational centers to fully test, evaluate, and implement new physics. The process is complicated by the scarcity of like-to-like comparisons, availability of HPC resources, and the ``tuning problem" whereby advances in physics schemes are difficult to properly evaluate without first undertaking the expensive and time-consuming process of tuning to other schemes within a suite. To address this process shortcoming, the Global Model TestBed (GMTB), supported by the NWS NGGPS project and undertaken by the Developmental Testbed Center, has developed a physics test harness. It implements the concept of hierarchical testing, where the same code can be tested in model configurations of varying complexity from single column models (SCM) to fully coupled, cycled global simulations. Developers and users may choose at which level of complexity to engage. Several components of the physics test harness have been implemented, including a SCM and an end-to-end workflow that expands upon the one used at NOAA/EMC to run the GFS operationally, although the testbed components will necessarily morph to coincide with changes to the operational configuration (FV3-GFS). A standard, relatively user-friendly interface known as the Interoperable Physics Driver (IPD) is available for physics developers to connect their codes. This prerequisite exercise allows access to the testbed tools and removes a technical hurdle for potential inclusion into the Common Community Physics Package (CCPP). The testbed offers users the opportunity to conduct like-to-like comparisons between the operational physics suite and new development as well as among multiple developments. GMTB staff have demonstrated use of the testbed through a

  15. Problem Solving in the Borderland between Mathematics and Physics

    ERIC Educational Resources Information Center

    Jensen, Jens Højgaard; Niss, Martin; Jankvist, Uffe Thomas

    2017-01-01

    The article addresses the problématique of where mathematization is taught in the educational system, and who teaches it. Mathematization is usually not a part of mathematics programs at the upper secondary level, but we argue that physics teaching has something to offer in this respect, if it focuses on solving so-called unformalized problems,…

  16. Muon Sources for Particle Physics - Accomplishments of the Muon Accelerator Program

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

    Neuffer, D.; Stratakis, D.; Palmer, M.

    The Muon Accelerator Program (MAP) completed a four-year study on the feasibility of muon colliders and on using stored muon beams for neutrinos. That study was broadly successful in its goals, establishing the feasibility of lepton colliders from the 125 GeV Higgs Factory to more than 10 TeV, as well as exploring using a μ storage ring (MSR) for neutrinos, and establishing that MSRs could provide factory-level intensities of νe (ν more » $$\\bar{e}$$) and ν $$\\bar{μ}$$) (ν μ) beams. The key components of the collider and neutrino factory systems were identified. Feasible designs and detailed simulations of all of these components were obtained, including some initial hardware component tests, setting the stage for future implementation where resources are available and clearly associated physics goals become apparent« less

  17. 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

  18. 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

  19. Gendered emotion work around physical health problems in mid- and later-life marriages.

    PubMed

    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. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. 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.

  1. Analysing the Problems of Science Teachers That They Encounter While Teaching Physics Education

    ERIC Educational Resources Information Center

    Demir, Cihat; Sincar, Burhan; Çelik, Ridvan

    2015-01-01

    Even though physical science is very important in our daily lives, it is insufficiently understood by students. In order for students to get a better physical education, the teachers who have given physics lesson should first eliminated the problems that they face during the teaching process. The aim of this survey is to specify the matters…

  2. Particle tracking acceleration via signed distance fields in direct-accelerated geometry Monte Carlo

    DOE PAGES

    Shriwise, Patrick C.; Davis, Andrew; Jacobson, Lucas J.; ...

    2017-08-26

    Computer-aided design (CAD)-based Monte Carlo radiation transport is of value to the nuclear engineering community for its ability to conduct transport on high-fidelity models of nuclear systems, but it is more computationally expensive than native geometry representations. This work describes the adaptation of a rendering data structure, the signed distance field, as a geometric query tool for accelerating CAD-based transport in the direct-accelerated geometry Monte Carlo toolkit. Demonstrations of its effectiveness are shown for several problems. The beginnings of a predictive model for the data structure's utilization based on various problem parameters is also introduced.

  3. Physical activity and sleep problems in 38 low- and middle-income countries.

    PubMed

    Vancampfort, Davy; Stubbs, Brendon; Smith, Lee; Hallgren, Mats; Firth, Joseph; Herring, Matthew P; Probst, Michel; Koyanagi, Ai

    2018-05-24

    Although physical activity (PA) is associated with a reduction of a wide range of sleep problems, it remains uncertain whether complying with the international guidelines of 150 min of moderate to vigorous PA per week can reduce sleep problems in adults. This research investigated the relationship between compliance with the PA recommendations of the World Health Organization and sleep problems in 38 low- and middle-income countries (LMICs). Cross-sectional, community-based data from the World Health Survey were analyzed. Adjusted logistic regression analyses were undertaken to explore the relationship between PA levels using the International Physical Activity Questionnaire and self-reported sleep problems (such as difficulties falling asleep, waking up frequently during the night or waking up too early in the morning) in the last 30 days. Across 204,315 individuals (38.6 ± 16.1 years; 49.3% males), the overall prevalence (95% CI) of low PA and sleep problems were 29.9% (29.1-30.8%) and 7.5% (7.2-7.9%), respectively. After adjusting for socio-demographics, obesity, chronic physical conditions, depression, and anxiety; not complying with PA recommendations was associated with higher odds for sleep problems overall [odds ratio (OR) = 1.23, 95% CI = 1.10-1.38] as well as across the entire age range: 18-34 years (OR = 1.26; 95% CI = 1.02-1.57); 35-64 years (OR = 1.17; 95% CI = 1.01-1.35); and age ≥65 years (OR = 1.40; 95% CI = 1.11-1.76). Not complying with international PA recommendations is associated with higher odds of sleep problems, independently of depression and anxiety in LMICs. Future longitudinal and interventional studies are warranted to assess whether increasing PA levels may improve sleep problems in this setting. Copyright © 2018 Elsevier B.V. All rights reserved.

  4. Magnetic Reconnection and Particle Acceleration in the Solar Corona

    NASA Astrophysics Data System (ADS)

    Neukirch, Thomas

    Reconnection plays a major role for the magnetic activity of the solar atmosphere, for example solar flares. An interesting open problem is how magnetic reconnection acts to redistribute the stored magnetic energy released during an eruption into other energy forms, e.g. gener-ating bulk flows, plasma heating and non-thermal energetic particles. In particular, finding a theoretical explanation for the observed acceleration of a large number of charged particles to high energies during solar flares is presently one of the most challenging problems in solar physics. One difficulty is the vast difference between the microscopic (kinetic) and the macro-scopic (MHD) scales involved. Whereas the phenomena observed to occur on large scales are reasonably well explained by the so-called standard model, this does not seem to be the case for the small-scale (kinetic) aspects of flares. Over the past years, observations, in particular by RHESSI, have provided evidence that a naive interpretation of the data in terms of the standard solar flare/thick target model is problematic. As a consequence, the role played by magnetic reconnection in the particle acceleration process during solar flares may have to be reconsidered.

  5. 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.

  6. Stochastic Particle Acceleration in Impulsive Solar Flares

    NASA Technical Reports Server (NTRS)

    Miller, James A.

    2001-01-01

    The acceleration of a huge number of electrons and ions to relativistic energies over timescales ranging from several seconds to several tens of seconds is the fundamental problem in high-energy solar physics. The cascading turbulence model we have developed has been shown previously (e.g., Miller 2000; Miller & Roberts 1995; Miner, LaRosa, & Moore 1996) to account for all the bulk features (such as acceleration timescales, fluxes, total number of energetic particles, and maximum energies) of electron and proton acceleration in impulsive solar flares. While the simulation of this acceleration process is involved, the essential idea of the model is quite simple, and consists of just a few parts: 1. During the primary flare energy release phase, we assume that low-amplitude MHD Alfven and fast mode waves are excited at long wavelengths, say comparable to the size of the event (although the results are actually insensitive to this initial wavelength). While an assumption, this appears reasonable in light of the likely highly turbulent nature of the flare. 2. These waves then cascade in a Kolmogorov-like fashion to smaller wavelengths (e.g., Verma et al. 1996), forming a power-law spectral density in wavenumber space through the inertial range. 3. When the mean wavenumber of the fast mode waves has increased sufficiently, the transit-time acceleration rate (Miller 1997) for superAlfvenic electrons can overcome Coulomb energy losses, and these electrons are accelerated out of the thermal distribution and to relativistic energies (Miller et al. 1996). As the Alfven waves cascade to higher wavenumbers, they can cyclotron resonate with progressively lower energy protons. Eventually, they will resonate with protons in the tail of the thermal distribution, which will then be accelerated to relativistic energies as well (Miller & Roberts 1995). Hence, both ions and electrons are stochastically accelerated, albeit by different mechanisms and different waves. 4. When the

  7. Low-energy ion acceleration at quasi-perpendicular shocks: Transverse diffusion

    NASA Technical Reports Server (NTRS)

    Giacalone, J.; Jokipii, J. R.

    1995-01-01

    The problem of ion injection and acceleration at quasi perpendicular shocks has been the subject of some debate over the past two decades. It is widely known that these shocks efficiently accelerate particles that are well in the high-energy tail of the distribution. However, the issue of injection, or the acceleration of low-energy ions, has yet to reach a consensus. The fundamental issue is whether there is enough diffusion normal to the magnetic field for the particles to remain near the shock. Since transverse diffusion is a physical process that is not well understood in space plasmas, this is an important, and difficult issue to address. In this report, we will investigate the ion injection problem by performing test particle orbit integrations using synthesized turbulent fields. These fields are fully three-dimensional so that transverse diffusion is possible (cross-field diffusion is not possible in geometries where the electromagnetic fields are less than three dimensional). The synthesized fields are produced by superimposing a three-dimensional wave field on a background field. For completeness, we will compare the results from this model with the more well-established theories, such as the diffusive approximation and scatter-free shock drift acceleration. We will also compare these results with other numerical simulation techniques such as the well known hybrid simulation, and other test-particle calculations in which the shock fields are specified to have less than three dimensions. We will also discuss some recent relevant observations and how these compare with our results.

  8. Multi-representation ability of students on the problem solving physics

    NASA Astrophysics Data System (ADS)

    Theasy, Y.; Wiyanto; Sujarwata

    2018-03-01

    Accuracy in representing knowledge possessed by students will show how the level of student understanding. The multi-representation ability of students on the problem solving of physics has been done through qualitative method of grounded theory model and implemented on physics education student of Unnes academic year 2016/2017. Multiforms of representation used are verbal (V), images/diagrams (D), graph (G), and mathematically (M). High and low category students have an accurate use of graphical representation (G) of 83% and 77.78%, and medium category has accurate use of image representation (D) equal to 66%.

  9. Exploring problem-based cooperative learning in undergraduate physics labs: student perspectives

    NASA Astrophysics Data System (ADS)

    Bergin, S. D.; Murphy, C.; Shuilleabhain, A. Ni

    2018-03-01

    This study examines the potential of problem-based cooperative learning (PBCL) in expanding undergraduate physics students’ understanding of, and engagement with, the scientific process. Two groups of first-year physics students (n = 180) completed a questionnaire which compared their perceptions of learning science with their engagement in physics labs. One cohort completed a lab based on a PBCL approach, whilst the other completed the same experiment, using a more traditional, manual-based lab. Utilising a participant research approach, the questionnaire was co-constructed by researchers and student advisers from each cohort in order to improve shared meaning between researchers and participants. Analysis of students’ responses suggests that students in the PBCL cohort engaged more in higher-order problem-solving skills and evidenced a deeper understanding of the scientific process than students in the more traditional, manual-based cohort. However, the latter cohort responses placed more emphasis on accuracy and measurement in lab science than the PBCL cohort. The students in the PBCL cohort were also more positively engaged with their learning than their counterparts in the manual led group.

  10. A Theoretical Analysis: Physical Unclonable Functions and The Software Protection Problem

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

    Nithyanand, Rishab; Solis, John H.

    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. This property of unclonability is due to the accepted hardness of replicating the multitude of uncontrollable manufacturing characteristics and makes PUFs useful in 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 and show that traditional non-computational (black-box) PUFs cannot solve the problem against real world adversaries in offline settings. Our contributionsmore » are the following: We provide two real world adversary models (weak and strong variants) and present definitions for security against the adversaries. We continue by proposing schemes secure against the weak adversary and show that no scheme is secure against a strong adversary without the use of trusted hardware. Finally, we present a protection scheme secure against strong adversaries based on trusted hardware.« less

  11. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Covariant Uniform Acceleration

    NASA Astrophysics Data System (ADS)

    Friedman, Yaakov; Scarr, Tzvi

    2013-04-01

    We derive a 4D covariant Relativistic Dynamics Equation. This equation canonically extends the 3D relativistic dynamics equation , where F is the 3D force and p = m0γv is the 3D relativistic momentum. The standard 4D equation is only partially covariant. To achieve full Lorentz covariance, we replace the four-force F by a rank 2 antisymmetric tensor acting on the four-velocity. By taking this tensor to be constant, we obtain a covariant definition of uniformly accelerated motion. This solves a problem of Einstein and Planck. We compute explicit solutions for uniformly accelerated motion. The solutions are divided into four Lorentz-invariant types: null, linear, rotational, and general. For null acceleration, the worldline is cubic in the time. Linear acceleration covariantly extends 1D hyperbolic motion, while rotational acceleration covariantly extends pure rotational motion. We use Generalized Fermi-Walker transport to construct a uniformly accelerated family of inertial frames which are instantaneously comoving to a uniformly accelerated observer. We explain the connection between our approach and that of Mashhoon. We show that our solutions of uniformly accelerated motion have constant acceleration in the comoving frame. Assuming the Weak Hypothesis of Locality, we obtain local spacetime transformations from a uniformly accelerated frame K' to an inertial frame K. The spacetime transformations between two uniformly accelerated frames with the same acceleration are Lorentz. We compute the metric at an arbitrary point of a uniformly accelerated frame. We obtain velocity and acceleration transformations from a uniformly accelerated system K' to an inertial frame K. We introduce the 4D velocity, an adaptation of Horwitz and Piron s notion of "off-shell." We derive the general formula for the time dilation between accelerated clocks. We obtain a formula for the angular velocity of a uniformly accelerated object. Every rest point of K' is uniformly accelerated, and

  13. Beam transport results on the multi-beam MABE accelerator

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

    Coleman, P.D.; Alexander, J.A.; Hasti, D.E.

    1985-10-01

    MABE is a multistage, electron beam linear accelerator. The accelerator has been operated in single beam (60 kA, 7 Mev) and multiple beam configurations. This paper deals with the multiple beam configuration in which typically nine approx. = 25 kA injected beams are transported through three accelerating gaps. Experimental results from the machine are discussed, including problems encountered and proposed solutions to those problems.

  14. High field gradient particle accelerator

    DOEpatents

    Nation, J.A.; Greenwald, S.

    1989-05-30

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications is disclosed. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle. 10 figs.

  15. High field gradient particle accelerator

    DOEpatents

    Nation, John A.; Greenwald, Shlomo

    1989-01-01

    A high electric field gradient electron accelerator utilizing short duration, microwave radiation, and capable of operating at high field gradients for high energy physics applications or at reduced electric field gradients for high average current intermediate energy accelerator applications. Particles are accelerated in a smooth bore, periodic undulating waveguide, wherein the period is so selected that the particles slip an integral number of cycles of the r.f. wave every period of the structure. This phase step of the particles produces substantially continuous acceleration in a traveling wave without transverse magnetic or other guide means for the particle.

  16. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    DOE PAGES

    O’Shea, B. D.; Andonian, G.; Barber, S. K.; ...

    2016-09-14

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m –1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m –1 using a dielectric wakefield accelerator of 15 cmmore » length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m –1. As a result, both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons.« less

  17. Observation of acceleration and deceleration in gigaelectron-volt-per-metre gradient dielectric wakefield accelerators

    PubMed Central

    O'Shea, B. D.; Andonian, G.; Barber, S. K.; Fitzmorris, K. L.; Hakimi, S.; Harrison, J.; Hoang, P. D.; Hogan, M. J.; Naranjo, B.; Williams, O. B.; Yakimenko, V.; Rosenzweig, J. B.

    2016-01-01

    There is urgent need to develop new acceleration techniques capable of exceeding gigaelectron-volt-per-metre (GeV m−1) gradients in order to enable future generations of both light sources and high-energy physics experiments. To address this need, short wavelength accelerators based on wakefields, where an intense relativistic electron beam radiates the demanded fields directly into the accelerator structure or medium, are currently under intense investigation. One such wakefield based accelerator, the dielectric wakefield accelerator, uses a dielectric lined-waveguide to support a wakefield used for acceleration. Here we show gradients of 1.347±0.020 GeV m−1 using a dielectric wakefield accelerator of 15 cm length, with sub-millimetre transverse aperture, by measuring changes of the kinetic state of relativistic electron beams. We follow this measurement by demonstrating accelerating gradients of 320±17 MeV m−1. Both measurements improve on previous measurements by and order of magnitude and show promise for dielectric wakefield accelerators as sources of high-energy electrons. PMID:27624348

  18. Chirped pulse inverse free-electron laser vacuum accelerator

    DOEpatents

    Hartemann, Frederic V.; Baldis, Hector A.; Landahl, Eric C.

    2002-01-01

    A chirped pulse inverse free-electron laser (IFEL) vacuum accelerator for high gradient laser acceleration in vacuum. By the use of an ultrashort (femtosecond), ultrahigh intensity chirped laser pulse both the IFEL interaction bandwidth and accelerating gradient are increased, thus yielding large gains in a compact system. In addition, the IFEL resonance condition can be maintained throughout the interaction region by using a chirped drive laser wave. In addition, diffraction can be alleviated by taking advantage of the laser optical bandwidth with negative dispersion focusing optics to produce a chromatic line focus. The combination of these features results in a compact, efficient vacuum laser accelerator which finds many applications including high energy physics, compact table-top laser accelerator for medical imaging and therapy, material science, and basic physics.

  19. Plasma inverse transition acceleration

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

    Xie, Ming

    It can be proved fundamentally from the reciprocity theorem with which the electromagnetism is endowed that corresponding to each spontaneous process of radiation by a charged particle there is an inverse process which defines a unique acceleration mechanism, from Cherenkov radiation to inverse Cherenkov acceleration (ICA) [1], from Smith-Purcell radiation to inverse Smith-Purcell acceleration (ISPA) [2], and from undulator radiation to inverse undulator acceleration (IUA) [3]. There is no exception. Yet, for nearly 30 years after each of the aforementioned inverse processes has been clarified for laser acceleration, inverse transition acceleration (ITA), despite speculation [4], has remained the least understood,more » and above all, no practical implementation of ITA has been found, until now. Unlike all its counterparts in which phase synchronism is established one way or the other such that a particle can continuously gain energy from an acceleration wave, the ITA to be discussed here, termed plasma inverse transition acceleration (PITA), operates under fundamentally different principle. As a result, the discovery of PITA has been delayed for decades, waiting for a conceptual breakthrough in accelerator physics: the principle of alternating gradient acceleration [5, 6, 7, 8, 9, 10]. In fact, PITA was invented [7, 8] as one of several realizations of the new principle.« less

  20. The implementation of physical safety system in bunker of the electron beam accelerator

    NASA Astrophysics Data System (ADS)

    Ahmad, M. A.; Hashim, S. A.; Ahmad, A.; Leo, K. W.; Chulan, R. M.; Dalim, Y.; Baijan, A. H.; Zain, M. F.; Ros, R. C.

    2017-01-01

    This paper describes the implementation of physical safety system for the new low energy electron beam (EB) accelerator installed at Block 43T Nuclear Malaysia. The low energy EB is a locally designed and developed with a target energy of 300 keV. The issues on radiation protection have been addressed by the installation of radiation shielding in the form of a bunker and installation radiation monitors. Additional precaution is needed to ensure that personnel are not exposed to radiation and other physical hazards. Unintentional access to the radiation room can cause serious hazard and hence safety features must be installed to prevent such events. In this work we design and built a control and monitoring system for the shielding door. The system provides signals to the EB control panel to allow or prevent operation. The design includes limit switches, key-activated switches and emergency stop button and surveillance camera. Entry procedure is also developed as written record and for information purposes. As a result, through this safety implementation human error will be prevented, increase alertness during operation and minimizing unnecessary radiation exposure.

  1. Figuring the Acceleration of the Simple Pendulum

    ERIC Educational Resources Information Center

    Lieberherr, Martin

    2011-01-01

    The centripetal acceleration has been known since Huygens' (1659) and Newton's (1684) time. The physics to calculate the acceleration of a simple pendulum has been around for more than 300 years, and a fairly complete treatise has been given by C. Schwarz in this journal. But sentences like "the acceleration is always directed towards the…

  2. Achievement of learning outcome after implemented physical modules based on problem based learning

    NASA Astrophysics Data System (ADS)

    Isna, R.; Masykuri, M.; Sukarmin

    2018-03-01

    Implementation of Problem BasedLearning (PBL) modules can grow the students' thinking skills to solve the problems in daily life and equip the students into higher education levels. The purpose of this research is to know the achievement of learning outcome after implementation physics module based on PBL in Newton,s Law of Gravity. This research method use the experimental method with posttest only group design. To know the achievement of student learning outcomes was analyzed using t test through application of SPSS 18. Based on research result, it is found that the average of student learning outcomes after appliying physics module based on PBL has reached the minimal exhaustiveness criteria. In addition, students' scientific attitudes also improved at each meeting. Presentation activities which contained at learning sync are also able to practice speaking skills and broaden their knowledge. Looking at some shortcomings during the study, it is suggested the issues raised into learning should be a problem close to the life of students so that, the students are more active and enthusiastic in following the learning of physics.

  3. 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

  4. Thomas Jefferson National Accelerator Facility

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

    Grames, Joseph; Higinbotham, Douglas; Montgomery, Hugh

    The Thomas Jefferson National Accelerator Facility (Jefferson Lab) in Newport News, Virginia, USA, is one of ten national laboratories under the aegis of the Office of Science of the U.S. Department of Energy (DOE). It is managed and operated by Jefferson Science Associates, LLC. The primary facility at Jefferson Lab is the Continuous Electron Beam Accelerator Facility (CEBAF) as shown in an aerial photograph in Figure 1. Jefferson Lab was created in 1984 as CEBAF and started operations for physics in 1995. The accelerator uses superconducting radio-frequency (srf) techniques to generate high-quality beams of electrons with high-intensity, well-controlled polarization. Themore » technology has enabled ancillary facilities to be created. The CEBAF facility is used by an international user community of more than 1200 physicists for a program of exploration and study of nuclear, hadronic matter, the strong interaction and quantum chromodynamics. Additionally, the exceptional quality of the beams facilitates studies of the fundamental symmetries of nature, which complement those of atomic physics on the one hand and of high-energy particle physics on the other. The facility is in the midst of a project to double the energy of the facility and to enhance and expand its experimental facilities. Studies are also pursued with a Free-Electron Laser produced by an energy-recovering linear accelerator.« less

  5. [Methodological problems in the use of information technologies in physical education].

    PubMed

    Martirosov, E G; Zaĭtseva, G A

    2000-01-01

    The paper considers methodological problems in the use of computer technologies in physical education by applying diagnostic and consulting systems, educational and educational-and-training process automation systems, and control and self-control programmes for athletes and others.

  6. 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…

  7. (Installation of the Vinca Accelerator)

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

    Zucker, A.

    1991-04-22

    I participated in a workshop of the physics with accelerators in Belgrade, Yugoslavia and chaired an advisory committee for the Vinca Accelerator Installation which is currently in progress. Also, I participated in meetings with the Serbian Academy of Sciences and with the Deputy Prime Minister of Serbia concerning the plans and aspirations of the nuclear research center at Vinca.

  8. Prediction of scaling physics laws for proton acceleration with extended parameter space of the NIF ARC

    NASA Astrophysics Data System (ADS)

    Bhutwala, Krish; Beg, Farhat; Mariscal, Derek; Wilks, Scott; Ma, Tammy

    2017-10-01

    The Advanced Radiographic Capability (ARC) laser at the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the world's most energetic short-pulse laser. It comprises four beamlets, each of substantial energy ( 1.5 kJ), extended short-pulse duration (10-30 ps), and large focal spot (>=50% of energy in 150 µm spot). This allows ARC to achieve proton and light ion acceleration via the Target Normal Sheath Acceleration (TNSA) mechanism, but it is yet unknown how proton beam characteristics scale with ARC-regime laser parameters. As theory has also not yet been validated for laser-generated protons at ARC-regime laser parameters, we attempt to formulate the scaling physics of proton beam characteristics as a function of laser energy, intensity, focal spot size, pulse length, target geometry, etc. through a review of relevant proton acceleration experiments from laser facilities across the world. These predicted scaling laws should then guide target design and future diagnostics for desired proton beam experiments on the NIF ARC. This work performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344 and funded by the LLNL LDRD program under tracking code 17-ERD-039.

  9. Coilgun Acceleration Model Containing Interactions Between Multiple Coils

    NASA Technical Reports Server (NTRS)

    Liu, Connie; Polzin, Kurt; Martin, Adam

    2017-01-01

    Electromagnetic (EM) accelerators have the potential to fill a performance range not currently being met by conventional chemical and electric propulsion systems by providing a specific impulse of 600-1000 seconds and a thrust-to-power ratio greater than 200 mN/kW. A propulsion system based on EM acceleration of small projectiles has the traditional advantages of using a pulsed system, including precise control over a range of thrust and power levels as well as rapid response and repetition rates. Furthermore, EM accelerators have lower power requirements than conventional electric propulsion systems since no plasma creation is necessary. A coilgun is a specific type of EM device where a high-current pulse through a coil of wire interacts with a conductive projectile via an induced magnetic field to accelerate the projectile. There are no physical or electrical connections to the projectile, which leads to less system degradation and a longer life expectancy. Multi-staging a coilgun by adding multiple turns on a single coil or on the projectile increases the inductance, thus permitting acceleration of the projectile to higher velocities. Previously, a simplified problem of modeling an inductively-coupled, single-coil coilgun using a circuit-based analysis coupled to the one-dimensional momentum equation through Lenz's law was solved; however, the analysis was only conducted on uncoupled coils. The problem is significantly more complicated when multiple, independently-powered coils simultaneously operate and interact with each other and the projectile through induced magnetic fields. This paper presents a multi-coil model developed with the magnetostatic finite element solver QuickField. In the model, mutual inductance values between pairs of conductors were found by first computing the magnetic field energy for different cases where individual coils or multiple coils carry current, then integrating over the entire finite element domain for each case, and finally

  10. An ion accelerator for undergraduate research and teaching

    NASA Astrophysics Data System (ADS)

    Monce, Michael

    1997-04-01

    We have recently upgraded our 400kV, single beam line ion accelerator to a 1MV, multiple beam line machine. This upgrade has greatly expanded the opportunities for student involvement in the laboratory. We will describe four areas of work in which students now participate. The first is the continuing research being conducted in excitations produced in ion-molecule collisions, which recently involved the use of digital imaging. The second area of research now opened up by the new accelerator involves PIXE. We are currently beginning a cross disciplinary study of archaeological specimens using PIXE and involving students from both anthropology and physics. Finally, two beam lines from the accelerator will be used for basic work in nuclear physics: Rutherford scattering and nuclear resonances. These two nuclear physics experiments will be integrated into our sophomore-junior level, year-long course in experimental physics.

  11. What We Don't Understand About Ion Acceleration Flares

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.; Ng, C. K.; Tylka, A. J.

    1999-01-01

    There are now strong associations between the (3)He-rich, Fe-rich ions in "impulsive" solar energetic particle (SEP) events and the similar abundances derived from gamma-ray lines from flares. Compact flares, where wave energy can predominate, are ideal sites for the study of wave-particle physics. Yet there are nagging questions about the magnetic geometry, the relation between ions that escape and those that interact, and the relative roles of cascading Alfven waves and the EMIC waves required to enhance He-3. There are also questions about the relative timing of ion and electron acceleration and of heating; these relate to the variation of ionization states before and during acceleration and during transport out of the corona. We can construct a model that addresses many of these issues, but problems do remain. Our greatest lack is realistic theoretical simulations of element abundances, spectra, and their variations. By contrast, we now have a much better idea of the acceleration at CME-driven shock waves in the rare but large "gradual" SEP events, largely because of their slow temporal evolution and great spatial extent.

  12. 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"…

  13. The Role of Content Knowledge in Ill-Structured Problem Solving for High School Physics Students

    ERIC Educational Resources Information Center

    Milbourne, Jeff; Wiebe, Eric

    2018-01-01

    While Physics Education Research has a rich tradition of problem-solving scholarship, most of the work has focused on more traditional, well-defined problems. Less work has been done with ill-structured problems, problems that are better aligned with the engineering and design-based scenarios promoted by the Next Generation Science Standards. This…

  14. MO-DE-BRA-02: SIMAC: A Simulation Tool for Teaching Linear Accelerator Physics

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

    Carlone, M; Harnett, N; Department of Radiation Oncology, University of Toronto, Toronto, Ontario

    Purpose: The first goal of this work is to develop software that can simulate the physics of linear accelerators (linac). The second goal is to show that this simulation tool is effective in teaching linac physics to medical physicists and linac service engineers. Methods: Linacs were modeled using analytical expressions that can correctly describe the physical response of a linac to parameter changes in real time. These expressions were programmed with a graphical user interface in order to produce an environment similar to that of linac service mode. The software, “SIMAC”, has been used as a learning aid in amore » professional development course 3 times (2014 – 2016) as well as in a physics graduate program. Exercises were developed to supplement the didactic components of the courses consisting of activites designed to reinforce the concepts of beam loading; the effect of steering coil currents on beam symmetry; and the relationship between beam energy and flatness. Results: SIMAC was used to teach 35 professionals (medical physicists; regulators; service engineers; 1 week course) as well as 20 graduate students (1 month project). In the student evaluations, 85% of the students rated the effectiveness of SIMAC as very good or outstanding, and 70% rated the software as the most effective part of the courses. Exercise results were collected showing that 100% of the students were able to use the software correctly. In exercises involving gross changes to linac operating points (i.e. energy changes) the majority of students were able to correctly perform these beam adjustments. Conclusion: Software simulation(SIMAC), can be used to effectively teach linac physics. In short courses, students were able to correctly make gross parameter adjustments that typically require much longer training times using conventional training methods.« less

  15. Obstacles Related to Structuring for Mathematization Encountered by Students When Solving Physics Problems

    ERIC Educational Resources Information Center

    Niss, Martin

    2017-01-01

    This paper studies the cognitive obstacles related to one aspect of mathematization in physics problem-solving, namely, what might be called "structuring for mathematization," where the problem situation is structured in such a way that a translation to a mathematical universe can be done. We report the results of an analysis of four…

  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. Accelerators for America's Future

    NASA Astrophysics Data System (ADS)

    Bai, Mei

    2016-03-01

    Particle accelerator, a powerful tool to energize beams of charged particles to a desired speed and energy, has been the working horse for investigating the fundamental structure of matter and fundermental laws of nature. Most known examples are the 2-mile long Stanford Linear Accelerator at SLAC, the high energy proton and anti-proton collider Tevatron at FermiLab, and Large Hadron Collider that is currently under operation at CERN. During the less than a century development of accelerator science and technology that led to a dazzling list of discoveries, particle accelerators have also found various applications beyond particle and nuclear physics research, and become an indispensible part of the economy. Today, one can find a particle accelerator at almost every corner of our lives, ranging from the x-ray machine at the airport security to radiation diagnostic and therapy in hospitals. This presentation will give a brief introduction of the applications of this powerful tool in fundermental research as well as in industry. Challenges in accelerator science and technology will also be briefly presented

  18. The Role of Content Knowledge in Ill-Structured Problem Solving for High School Physics Students

    NASA Astrophysics Data System (ADS)

    Milbourne, Jeff; Wiebe, Eric

    2018-02-01

    While Physics Education Research has a rich tradition of problem-solving scholarship, most of the work has focused on more traditional, well-defined problems. Less work has been done with ill-structured problems, problems that are better aligned with the engineering and design-based scenarios promoted by the Next Generation Science Standards. This study explored the relationship between physics content knowledge and ill-structured problem solving for two groups of high school students with different levels of content knowledge. Both groups of students completed an ill-structured problem set, using a talk-aloud procedure to narrate their thought process as they worked. Analysis of the data focused on identifying students' solution pathways, as well as the obstacles that prevented them from reaching "reasonable" solutions. Students with more content knowledge were more successful reaching reasonable solutions for each of the problems, experiencing fewer obstacles. These students also employed a greater variety of solution pathways than those with less content knowledge. Results suggest that a student's solution pathway choice may depend on how she perceives the problem.

  19. 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…

  20. Optimization of a Small Scale Linear Reluctance Accelerator

    NASA Astrophysics Data System (ADS)

    Barrera, Thor; Beard, Robby

    2011-11-01

    Reluctance accelerators are extremely promising future methods of transportation. Several problems still plague these devices, most prominently low efficiency. Variables to overcoming efficiency problems are many and difficult to correlate how they affect our accelerator. The study examined several differing variables that present potential challenges in optimizing the efficiency of reluctance accelerators. These include coil and projectile design, power supplies, switching, and the elusive gradient inductance problem. Extensive research in these areas has been performed from computational and theoretical to experimental. Findings show that these parameters share significant similarity to transformer design elements, thus general findings show current optimized parameters the research suggests as a baseline for further research and design. Demonstration of these current findings will be offered at the time of presentation.

  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. Application of particle accelerators in research.

    PubMed

    Mazzitelli, Giovanni

    2011-07-01

    Since the beginning of the past century, accelerators have started to play a fundamental role as powerful tools to discover the world around us, how the universe has evolved since the big bang and to develop fundamental instruments for everyday life. Although more than 15 000 accelerators are operating around the world only a very few of them are dedicated to fundamental research. An overview of the present high energy physics (HEP) accelerator status and prospectives is presented.

  3. Collisionless Shocks and Particle Acceleration.

    NASA Astrophysics Data System (ADS)

    Malkov, M.

    2016-12-01

    Collisionless shocks emerged in the 50s and 60s of the last century as an important branch of plasma physics and have remained ever since. New applications pose new challenges to our understanding of collisionless shock mechanisms. Particle acceleration in astrophysical settings, primarily studied concerning the putative origin of cosmic rays (CR) in supernova remnant (SNR) shocks, stands out with the collisionless shock mechanism being the key. Among recent laboratory applications, a laser-based tabletop proton accelerator is an affordable compact alternative to big synchrotron accelerators. The much-anticipated proof of cosmic ray (CR) acceleration in supernova remnants is hindered by our limited understanding of collisionless shock mechanisms. Over the last decade, dramatically improved observations were puzzling the theorists with unexpected discoveries. The difference between the helium/carbon and proton CR rigidity (momentum to charge ratio) spectra, seemingly inconsistent with the acceleration and propagation theories, and the perplexing positron excess in the 10-300 GeV range are just two recent examples. The latter is now also actively discussed in the particle physics and CR communities as a possible signature of decay or annihilation of hypothetical dark matter particles. By considering an initial (injection) phase of a diffusive shock acceleration mechanism, including particle reflection off the shock front - where an elemental similarity of particle dynamics does not apply - I will discuss recent suggestions of how to address the new data from the collisionless shock perspective. The backreaction of accelerated particles on the shock structure, its environment, and visibility across the electromagnetic spectrum from radio to gamma rays is another key aspect of collisionless shock that will be discussed.

  4. ADHD-related symptoms, emotional/behavioral problems, and physical conditions in Taiwanese children with epilepsy.

    PubMed

    Tsai, Fang-Ju; Liu, Shu-Tsen; Lee, Chi-Mei; Lee, Wang-Tso; Fan, Pi-Chuan; Lin, Wei-Sheng; Chiu, Yen-Nan; Gau, Susan Shur-Fen

    2013-07-01

    Little is known about whether Asian children with epilepsy have more attention-deficit hyperactivity disorder (ADHD)-related symptoms, emotional/ behavioral problems, and physical conditions compared with those described in Western studies. The authors investigated the rates of ADHD-related symptoms, emotional/behavioral problems, and physical conditions among pediatric patients with epilepsy. We recruited 61 patients with epilepsy, aged 6-16 years, and 122 age-, sex-, and parental education-matched school controls. Data on demographics, parental reports on the Child Behavior Checklist (CBCL) and Swanson, Nolan, and Pelham, version IV scale (SNAP-IV), and medical records were collected. The average full-scale intelligence quotient of the case group was 95.8. There were 11 (18.0%), 7 (11.5%), 26 (42.6%), and 26 (42.6%) of children with epilepsy ever clinically diagnosed with developmental delay, overt ADHD symptoms, allergies reported by physicians, and behavior problems measured by the CBCL, respectively. Those children with epilepsy had more severe ADHD-related symptoms and a wider range of emotional/behavioral problems than controls (Cohen's d 0.36-0.80). The rate of potential cases of ADHD among children with epilepsy was 24.6%. A history of developmental delay predicted ADHD- related symptoms and internalizing and externalizing problems. Among children with epilepsy, a longer duration of treatment with antiepileptic drugs predicted externalizing problems, and an earlier onset of epilepsy predicted inattention and hyperactivity/impulsivity. Our findings imply that clinicians should assess physical and emotional/behavioral problems among children with epilepsy in order to provide interventions to offset possible adverse psychiatric outcomes. Copyright © 2012. Published by Elsevier B.V.

  5. Fundamentals of Physics, Volume 1, (Chapters 1 - 21)

    NASA Astrophysics Data System (ADS)

    Walker, Jearl

    2004-01-01

    Chapter 1. Measurement 1. How does the appearance of a new type of cloud signal changes in Earth's atmosphere? 1-1 What Is Physics? 1-2 Measuring Things. 1-3 The International System of Units. 1-4 Changing Units. 1-5 Length. 1-6 Time. 1-7 Mass. Review & Summary. Problems. Chapter 2. Motion Along a Straight Line. What causes whiplash injury in rear-end collisions of cars? 2-1 What Is Physics? 2-2 Motion. 2-3 Position and Displacement. 2-4 Average Velocity and Average Speed. 2-5 Instantaneous Velocity and Speed. 2-6 Acceleration. 2-7 Constant Acceleration: A Special Case. 2-8 Another Look at Constant Acceleration. 2-9 Free-Fall Acceleration. 2-10 Graphical Integration in Motion Analysis. 2 Review & Summary. Questions. Problems. Chapter 3. Vectors. How does an ant know the way home with no guiding clues on the desert plains? 3-1 What Is Physics? 3-2 Vectors and Scalars. 3-3 Adding Vectors Geometrically. 3-4 Components of Vectors. 3-5 Unit Vectors. 3-6 Adding Vectors by Components. 3-7 Vectors and the Laws of Physics. 3-8 Multiplying Vectors. Review & Summary. Questions. Problems. Chapter 4. Motion in Two and Three Dimensions. In a motorcycle jump for record distance, where does the jumper put the second ramp? 4-1 What Is Physics? 4-2 Position and Displacement. 4-3 Average Velocity and Instantaneous Velocity. 4-4 Average Acceleration and Instantaneous Acceleration. 4-5 Projectile Motion. 4-6 Projectile Motion Analyzed. 4-7 Uniform Circular Motion. 4-8 Relative Motion in One Dimension. 4-9 Relative Motion in Two Dimensions. Review & Summary. Questions. Problems. Chapter 5. Force and Motion--I. When a pilot takes off from an aircraft carrier, what causes the compulsion to .y the plane into the ocean? 5-1 What Is Physics? 5-2 Newtonian Mechanics. 5-3 Newton's First Law. 5-4 Force. 5-5 Mass. 5-6 Newton's Second Law. 5-7 Some Particular Forces. 5-8 Newton's Third Law. 5-9 Applying Newton's Laws. Review & Summary. Questions. Problems. Chapter 6. Force and Motion--II. Can a

  6. Induction linear accelerators

    NASA Astrophysics Data System (ADS)

    Birx, Daniel

    1992-03-01

    Among the family of particle accelerators, the Induction Linear Accelerator is the best suited for the acceleration of high current electron beams. Because the electromagnetic radiation used to accelerate the electron beam is not stored in the cavities but is supplied by transmission lines during the beam pulse it is possible to utilize very low Q (typically<10) structures and very large beam pipes. This combination increases the beam breakup limited maximum currents to of order kiloamperes. The micropulse lengths of these machines are measured in 10's of nanoseconds and duty factors as high as 10-4 have been achieved. Until recently the major problem with these machines has been associated with the pulse power drive. Beam currents of kiloamperes and accelerating potentials of megavolts require peak power drives of gigawatts since no energy is stored in the structure. The marriage of liner accelerator technology and nonlinear magnetic compressors has produced some unique capabilities. It now appears possible to produce electron beams with average currents measured in amperes, peak currents in kiloamperes and gradients exceeding 1 MeV/meter, with power efficiencies approaching 50%. The nonlinear magnetic compression technology has replaced the spark gap drivers used on earlier accelerators with state-of-the-art all-solid-state SCR commutated compression chains. The reliability of these machines is now approaching 1010 shot MTBF. In the following paper we will briefly review the historical development of induction linear accelerators and then discuss the design considerations.

  7. 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.

  8. Absolute acceleration measurements on STS-50 from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1994-01-01

    Orbital Acceleration Research Experiment (OARE) data on Space Transportation System (STS)-50 have been examined in detail during a 2-day time period. Absolute acceleration levels have been derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. During the interval, the tri-axial OARE raw telemetered acceleration measurements have been filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval have been analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z-axis sensitive range scale factors were determined in a separate process using orbiter maneuvers and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter center-of-gravity, which are the aerodynamic signals along each body axis. Results indicate that there is a force being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces have been reexamined, but none produces the observed effect. Thus, it is tentatively concluded that the orbiter is creating the environment observed. At least part of this force is thought to be due to the Flash Evaporator System.

  9. 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.

  10. 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

  11. Operational health physics.

    PubMed

    Miller, Kenneth L

    2005-06-01

    A review of the operational health physics papers published in Health Physics and Operational Radiation Safety over the past fifteen years indicated seventeen general categories or areas into which the topics could be readily separated. These areas include academic research programs, use of computers in operational health physics, decontamination and decommissioning, dosimetry, emergency response, environmental health physics, industrial operations, medical health physics, new procedure development, non-ionizing radiation, radiation measurements, radioactive waste disposal, radon measurement and control, risk communication, shielding evaluation and specification, staffing levels for health physics programs, and unwanted or orphan sources. That is not to say that there are no operational papers dealing with specific areas of health physics, such as power reactor health physics, accelerator health physics, or governmental health physics. On the contrary, there have been a number of excellent operational papers from individuals in these specialty areas and they are included in the broader topics listed above. A listing and review of all the operational papers that have been published is beyond the scope of this discussion. However, a sampling of the excellent operational papers that have appeared in Health Physics and Operational Radiation Safety is presented to give the reader the flavor of the wide variety of concerns to the operational health physicist and the current areas of interest where procedures are being refined and solutions to problems are being developed.

  12. Operational health physics.

    PubMed

    Miller, Kenneth L

    2005-01-01

    A review of the operational health physics papers published in Health Physics and Operational Radiation Safety over the past fifteen years indicated seventeen general categories or areas into which the topics could be readily separated. These areas include academic research programs, use of computers in operational health physics, decontamination and decommissioning, dosimetry, emergency response, environmental health physics, industrial operations, medical health physics, new procedure development, non-ionizing radiation, radiation measurements, radioactive waste disposal, radon measurement and control, risk communication, shielding evaluation and specification, staffing levels for health physics programs, and unwanted or orphan sources. That is not to say that there are no operational papers dealing with specific areas of health physics, such as power reactor health physics, accelerator health physics, or governmental health physics. On the contrary, there have been a number of excellent operational papers from individuals in these specialty areas and they are included in the broader topics listed above. A listing and review of all the operational papers that have been published is beyond the scope of this discussion. However, a sampling of the excellent operational papers that have appeared in Health Physics and Operational Radiation Safety is presented to give the reader the flavor of the wide variety of concerns to the operational health physicist and the current areas of interest where procedures are being refined and solutions to problems are being developed.

  13. Introduction to Particle Acceleration in the Cosmos

    NASA Technical Reports Server (NTRS)

    Gallagher, D. L.; Horwitz, J. L.; Perez, J.; Quenby, J.

    2005-01-01

    Accelerated charged particles have been used on Earth since 1930 to explore the very essence of matter, for industrial applications, and for medical treatments. Throughout the universe nature employs a dizzying array of acceleration processes to produce particles spanning twenty orders of magnitude in energy range, while shaping our cosmic environment. Here, we introduce and review the basic physical processes causing particle acceleration, in astrophysical plasmas from geospace to the outer reaches of the cosmos. These processes are chiefly divided into four categories: adiabatic and other forms of non-stochastic acceleration, magnetic energy storage and stochastic acceleration, shock acceleration, and plasma wave and turbulent acceleration. The purpose of this introduction is to set the stage and context for the individual papers comprising this monograph.

  14. Large-scale studies on the transferability of general problem-solving skills and the pedagogic potential of physics

    NASA Astrophysics Data System (ADS)

    Mashood, K. K.; Singh, Vijay A.

    2013-09-01

    Research suggests that problem-solving skills are transferable across domains. This claim, however, needs further empirical substantiation. We suggest correlation studies as a methodology for making preliminary inferences about transfer. The correlation of the physics performance of students with their performance in chemistry and mathematics in highly competitive problem-solving examinations was studied using a massive database. The sample sizes ranged from hundreds to a few hundred thousand. Encouraged by the presence of significant correlations, we interviewed 20 students to explore the pedagogic potential of physics in imparting transferable problem-solving skills. We report strategies and practices relevant to physics employed by these students which foster transfer.

  15. Acceleration of boundary element method for linear elasticity

    NASA Astrophysics Data System (ADS)

    Zapletal, Jan; Merta, Michal; Čermák, Martin

    2017-07-01

    In this work we describe the accelerated assembly of system matrices for the boundary element method using the Intel Xeon Phi coprocessors. We present a model problem, provide a brief overview of its discretization and acceleration of the system matrices assembly using the coprocessors, and test the accelerated version using a numerical benchmark.

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

    NASA Astrophysics Data System (ADS)

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

    2011-09-01

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

  17. Accelerator science and technology in Europe: EuCARD 2012

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2012-05-01

    Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, shown during the third annual meeting of the EuCARD - European Coordination of Accelerator Research and Development. The conference concerns building of the research infrastructure, including in this advanced photonic and electronic systems for servicing large high energy physics experiments. There are debated a few basic groups of such systems like: measurement - control networks of large geometrical extent, multichannel systems for large amounts of metrological data acquisition, precision photonic networks of reference time, frequency and phase distribution.

  18. Physical activity is associated with the physical, psychological, social and environmental quality of life in people with mental health problems in a low resource setting.

    PubMed

    Vancampfort, Davy; Van Damme, Tine; Probst, Michel; Firth, Joseph; Stubbs, Brendon; Basangwa, David; Mugisha, James

    2017-12-01

    There is a growing recognition of the importance of encouraging patients with mental health problems to become more active as an efficacious strategy to reduce the disability-associated burden. The aim of the current study was to investigate if there are differences in quality of life (QoL) outcomes between people with mental health problems that do and do not meet the recommendations of 150min per week of physical activity. 109 (36♀) Ugandan in- and outpatients (mean age = 34.2 ± 10.2 years) (depression = 7, bipolar disorder = 31, schizophrenia = 21, alcohol use disorder = 50) completed the Physical Activity Vital Sign (PAVS) method and World Health Organization Quality of Life Assessment brief version. Those who did not achieve the minimum physical activity recommendations as assessed by the PAVS (n = 63) had a lower physical, psychological, social and environmental QoL. The current data offer further evidence that the PAVS method might be an important risk identification tool in people with mental health problems. The feasibility and acceptability of the PAVS may help promote the importance of physical activity assessment and prescription as a core part of the treatment of mental health problems in LMICs. Copyright © 2017 Elsevier B.V. All rights reserved.

  19. Physics through the 1990s: Nuclear physics

    NASA Technical Reports Server (NTRS)

    1986-01-01

    The volume begins with a non-mathematical introduction to nuclear physics. A description of the major advances in the field follows, with chapters on nuclear structure and dynamics, fundamental forces in the nucleus, and nuclei under extreme conditions of temperature, density, and spin. Impacts of nuclear physics on astrophysics and the scientific and societal benefits of nuclear physics are then discussed. Another section deals with scientific frontiers, describing research into the realm of the quark-gluon plasma; the changing description of nuclear matter, specifically the use of the quark model; and the implications of the standard model and grand unified theories of elementary-particle physics; and finishes with recommendations and priorities for nuclear physics research facilities, instrumentation, accelerators, theory, education, and data bases. Appended are a list of national accelerator facilities, a list of reviewers, a bibliography, and a glossary.

  20. Λ CDM is Consistent with SPARC Radial Acceleration Relation

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

    Keller, B. W.; Wadsley, J. W., E-mail: kellerbw@mcmaster.ca

    2017-01-20

    Recent analysis of the Spitzer Photometry and Accurate Rotation Curve (SPARC) galaxy sample found a surprisingly tight relation between the radial acceleration inferred from the rotation curves and the acceleration due to the baryonic components of the disk. It has been suggested that this relation may be evidence for new physics, beyond Λ CDM . In this Letter, we show that 32 galaxies from the MUGS2 match the SPARC acceleration relation. These cosmological simulations of star-forming, rotationally supported disks were simulated with a WMAP3 Λ CDM cosmology, and match the SPARC acceleration relation with less scatter than the observational data.more » These results show that this acceleration relation is a consequence of dissipative collapse of baryons, rather than being evidence for exotic dark-sector physics or new dynamical laws.« less

  1. The United States Particle Accelerator School: Educating the Next Generation of Accelerator Scientists and Engineers

    NASA Astrophysics Data System (ADS)

    Barletta, William A.

    2009-03-01

    Only a handful of universities in the US offer any formal training in accelerator science. The United States Particle Accelerator School (USPAS) is National Graduate Educational Program that has developed a highly successful educational paradigm that, over the past twenty-years, has granted more university credit in accelerator/beam science and technology than any university in the world. Sessions are held twice annually, hosted by major US research universities that approve course credit, certify the USPAS faculty, and grant course credit. The USPAS paradigm is readily extensible to other rapidly developing, cross-disciplinary research areas such as high energy density physics.

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

    ERIC Educational Resources Information Center

    Sahin, Mehmet

    2009-01-01

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

  3. Andy Sessler: The Full Life of an Accelerator Physicist

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Je; Budnitz, Robert J.; Winick, Herman

    2015-02-01

    This article describes the distinguished career of Andrew M. Sessler, the visionary former director of the Lawrence Berkeley National Laboratory (LBNL), one of the most influential accelerator physicists, and a strong, dedicated human-rights activist. Andy died on 17 April 2014 from cancer at age 85. He grew up in New York City, and attended Harvard (BA in Mathematics, 1949) and then Columbia (PhD in Physics, 1953.) After an NSF postdoc at Cornell with Hans Bethe and a stint on the faculty at the Ohio State University in 1954-59, he joined the Lawrence Radiation Laboratory (now LBNL) in 1959, and spent the remainder of his career there. Although Andy l his mark on several areas of physics, including nuclear structure theory, elementary-particle physics, and many-body problems, his lasting and most important contributions came from his efforts in accelerator physics and engineering, to which he devoted most of his life's work. In collaboration with his colleagues of the legendary Midwestern Universities Research Association, he developed theories for the RF acceleration process and the collective instability phenomena, helping to realize the colliding-beam accelerators with which most of the high-energy-physics discoveries of the last few decades have been made. His work in connection with the free-electron-laser (FEL) amplifier for high-power microwave generation constructed at the Lawrence Livermore National Laboratory anticipated the optical-guiding and the self-amplified spontaneous-emission principles, upon which the success of the X-ray FELs as the fourth-generation light sources is based. Throughout his career Andy made major contributions to issues related to the impact of science and technology on society. He helped usher in a new era of research on energy efficiency and sustainable-energy technology and was instrumental in building the research agendas in those areas for the Atomic Energy Commission (AEC) and later the Department of Energy. With a lifelong

  4. Andy Sessler: The Full Life of an Accelerator Physicist

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Je; Budnitz, Robert J.; Winick, Herman

    2014-04-01

    This article describes the distinguished career of Andrew M. Sessler, the visionary former director of the Lawrence Berkeley National Laboratory (LBNL), one of the most influential accelerator physicists, and a strong, dedicated human-rights activist. Andy died on 17 April 2014 from cancer at age 85. He grew up in New York City, and attended Harvard (BA in Mathematics, 1949) and then Columbia (PhD in Physics, 1953.) After an NSF postdoc at Cornell with Hans Bethe and a stint on the faculty at the Ohio State University in 1954-59, he joined the Lawrence Radiation Laboratory (now LBNL) in 1959, and spent the remainder of his career there. Although Andy l his mark on several areas of physics, including nuclear structure theory, elementary-particle physics, and many-body problems, his lasting and most important contributions came from his efforts in accelerator physics and engineering, to which he devoted most of his life's work. In collaboration with his colleagues of the legendary Midwestern Universities Research Association, he developed theories for the RF acceleration process and the collective instability phenomena, helping to realize the colliding-beam accelerators with which most of the high-energy-physics discoveries of the last few decades have been made. His work in connection with the free-electron-laser (FEL) amplifier for high-power microwave generation constructed at the Lawrence Livermore National Laboratory anticipated the optical-guiding and the self-amplified spontaneous-emission principles, upon which the success of the X-ray FELs as the fourth-generation light sources is based. Throughout his career Andy made major contributions to issues related to the impact of science and technology on society. He helped usher in a new era of research on energy efficiency and sustainable-energy technology and was instrumental in building the research agendas in those areas for the Atomic Energy Commission (AEC) and later the Department of Energy. With a lifelong

  5. Andy Sessler: The Full Life of an Accelerator Physicist

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Je; Budnitz, Robert J.; Winick, Herman

    This article describes the distinguished career of Andrew M. Sessler, the visionary former director of the Lawrence Berkeley National Laboratory (LBNL), one of the most influential accelerator physicists, and a strong, dedicated human-rights activist. Andy died on 17 April 2014 from cancer at age 85. He grew up in New York City, and attended Harvard (BA in Mathematics, 1949) and then Columbia (PhD in Physics, 1953.) After an NSF postdoc at Cornell with Hans Bethe and a stint on the faculty at the Ohio State University in 1954-59, he joined the Lawrence Radiation Laboratory (now LBNL) in 1959, and spent the remainder of his career there. Although Andy left his mark on several areas of physics, including nuclear structure theory, elementary-particle physics, and many-body problems, his lasting and most important contributions came from his efforts in accelerator physics and engineering, to which he devoted most of his life's work. In collaboration with his colleagues of the legendary Midwestern Universities Research Association, he developed theories for the RF acceleration process and the collective instability phenomena, helping to realize the colliding-beam accelerators with which most of the high-energy-physics discoveries of the last few decades have been made. His work in connection with the free-electron-laser (FEL) amplifier for high-power microwave generation constructed at the Lawrence Livermore National Laboratory anticipated the optical-guiding and the self-amplified spontaneous-emission principles, upon which the success of the X-ray FELs as the fourth-generation light sources is based. Throughout his career Andy made major contributions to issues related to the impact of science and technology on society. He helped usher in a new era of research on energy efficiency and sustainable-energy technology and was instrumental in building the research agendas in those areas for the Atomic Energy Commission (AEC) and later the Department of Energy. With a

  6. [The physical problems in medicine].

    PubMed

    Bao, Shang-lian; Wang, Wei-dong; Fan, Tie-shuan

    2007-05-01

    According to the World Health Organization (WHO), the basic sciences to support the human health are chemistry, physics and informatics. Chemistry is the base of pharmacy. Physics is the base of medical instruments and equipments (MIE). The diagnosis and therapy of diseases are relying on informatics. Therefore, as the fusion results of physics and medicine, medical physics is the creative source science of MIE. Among all diagnosis tools, medical imaging devices are the fastest-developed and the most-complicated MIE since Roentgen discovered X-ray which was quickly used in medical diagnosis in 1895. Among all treatment tools, the radiotherapeutical devices are the most-widely used and the most effective MIE for tumor treatments since Mrs. Courier found the nature radiation isotope Radium at the end of 19th century and began to use it in tumor therapy. Although the research and development (R&D) of so-complicated MIE need many subjects of science and engineering, the kernel science is medical physics. With the results of more than 50 years' development in developed countries, medical physics has defined its own field, which is the medical imaging physics and the radiotherapeutical physics. But, the definition has been expanded to be wider and wider. Therefore, we should pay more attention to the establishment of Medical Physics in China. In order to develop medical physics in china, the bases of R&D and clinical practice should be also built.

  7. 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…

  8. Torque-based optimal acceleration control for electric vehicle

    NASA Astrophysics Data System (ADS)

    Lu, Dongbin; Ouyang, Minggao

    2014-03-01

    The existing research of the acceleration control mainly focuses on an optimization of the velocity trajectory with respect to a criterion formulation that weights acceleration time and fuel consumption. The minimum-fuel acceleration problem in conventional vehicle has been solved by Pontryagin's maximum principle and dynamic programming algorithm, respectively. The acceleration control with minimum energy consumption for battery electric vehicle(EV) has not been reported. In this paper, the permanent magnet synchronous motor(PMSM) is controlled by the field oriented control(FOC) method and the electric drive system for the EV(including the PMSM, the inverter and the battery) is modeled to favor over a detailed consumption map. The analytical algorithm is proposed to analyze the optimal acceleration control and the optimal torque versus speed curve in the acceleration process is obtained. Considering the acceleration time, a penalty function is introduced to realize a fast vehicle speed tracking. The optimal acceleration control is also addressed with dynamic programming(DP). This method can solve the optimal acceleration problem with precise time constraint, but it consumes a large amount of computation time. The EV used in simulation and experiment is a four-wheel hub motor drive electric vehicle. The simulation and experimental results show that the required battery energy has little difference between the acceleration control solved by analytical algorithm and that solved by DP, and is greatly reduced comparing with the constant pedal opening acceleration. The proposed analytical and DP algorithms can minimize the energy consumption in EV's acceleration process and the analytical algorithm is easy to be implemented in real-time control.

  9. Accelerated test plan for nickel cadmium spacecraft batteries

    NASA Technical Reports Server (NTRS)

    Hennigan, T. J.

    1973-01-01

    An accelerated test matrix is outlined that includes acceptance, baseline and post-cycling tests, chemical and physical analyses, and the data analysis procedures to be used in determining the feasibility of an accelerated test for sealed, nickel cadmium cells.

  10. 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.

  11. 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

  12. Experiences of physical and relational victimization in children with ADHD: The role of social problems and aggression.

    PubMed

    McQuade, Julia D; Breslend, Nicole L; Groff, Destin

    2018-04-16

    The social risk factors for physical and relational peer victimization were examined within a mixed-gender sample of children with and without attention-deficit/hyperactivity disorder (ADHD). Participants were 124 children (ages 8-12 years; 48% boys), with 47% exhibiting sub-clinical or clinical elevations in ADHD symptoms. ADHD and oppositional defiant disorder (ODD) symptom counts were assessed based on parent- and teacher-reports; parents rated children's social problems and teachers rated children's use of physical and relational aggression and experiences of physical and relational victimization. A multiple mediator model was used to test whether there were indirect effects of ADHD or ODD symptoms on physical and relational victimization through social problems, physical aggression, or relational aggression. At the bivariate level, ADHD and ODD symptoms were both significantly associated with higher rates of physical and relational victimization. In the mediational model, there were significant indirect effects of ADHD symptoms on relational victimization via social problems, of ODD on relational victimization via relational aggression, and of ODD symptoms on physical victimization via physical aggression. Results suggest that there are distinct risk factors implicated in the physical and relational victimization of youth with ADHD and that the co-occurrence of ODD symptoms is important to assess. Clinical implications for addressing victimization in children with ADHD are discussed. © 2018 Wiley Periodicals, Inc.

  13. Health problems in adolescents with alcohol use disorders: self-report, liver injury, and physical examination findings and correlates.

    PubMed

    Clark, D B; Lynch, K G; Donovan, J E; Block, G D

    2001-09-01

    Although adolescent alcohol consumption has been found to be positively correlated with self-reported health problems, few studies have examined other health indicators. This study compared adolescents with alcohol use disorders (AUDs) and a community reference group on self-reported health problems, serum liver enzymes, and physical examination findings. The relevance of negative emotionality to understanding these health problems was also investigated. The subjects were adolescents with AUDs recruited from clinical programs and classified as having DSM-IV alcohol dependence (n = 71) or alcohol abuse (n = 57) and reference adolescents without AUDs recruited from community sources (n = 131). The assessment of health status included self-reported health problems in 15 areas; serum liver enzyme assays, including gamma-glutamyl transpeptidase, alanine aminotransferase, and aspartate aminotransferase; and physical examination findings. Negative emotionality was determined by systematically combining scores from the Hamilton Anxiety Rating Scale, the Beck Depression Inventory, the Child Behavior Checklist, and the Multidimensional Personality Questionnaire. Adolescent AUDs were associated with more self-reported health problems, higher gamma-glutamyl transpeptidase and alanine aminotransferase levels, and more physical examination abnormalities. Negative emotionality was highly correlated with self-reported health problems, mediated the relationship between AUDs and self-reported health problems, and was not correlated with serum liver enzyme levels or physical examination abnormalities. These results indicated that AUDs during adolescence were associated with health problems, including modest but demonstrable liver injury. Self-reported health problems were probably best understood, in this context, as a negative emotionality manifestation.

  14. Acceleration technologies for charged particles: an introduction

    NASA Astrophysics Data System (ADS)

    Carter, Richard G.

    2011-01-01

    Particle accelerators have many important uses in scientific experiments, in industry and in medicine. This paper reviews the variety of technologies which are used to accelerate charged particles to high energies. It aims to show how the capabilities and limitations of these technologies are related to underlying physical principles. The paper emphasises the way in which different technologies are used together to convey energy from the electrical supply to the accelerated particles.

  15. Acceleration of cosmic rays in supernova-remnants

    NASA Technical Reports Server (NTRS)

    Dorfi, E. A.; Drury, L. O.

    1985-01-01

    It is commonly accepted that supernova-explosions are the dominant source of cosmic rays up to an energy of 10 to the 14th power eV/nucleon. Moreover, these high energy particles provide a major contribution to the energy density of the interstellar medium (ISM) and should therefore be included in calculations of interstellar dynamic phenomena. For the following the first order Fermi mechanism in shock waves are considered to be the main acceleration mechanism. The influence of this process is twofold; first, if the process is efficient (and in fact this is the cas) it will modify the dynamics and evolution of a supernova-remnant (SNR), and secondly, the existence of a significant high energy component changes the overall picture of the ISM. The complexity of the underlying physics prevented detailed investigations of the full non-linear selfconsistent problem. For example, in the context of the energy balance of the ISM it has not been investigated how much energy of a SN-explosion can be transfered to cosmic rays in a time-dependent selfconsistent model. Nevertheless, a lot of progress was made on many aspects of the acceleration mechanism.

  16. Amplitude-dependent orbital period in alternating gradient accelerators

    DOE PAGES

    Machida, S.; Kelliher, D. J.; Edmonds, C. S.; ...

    2016-03-16

    Orbital period in a ring accelerator and time of flight in a linear accelerator depend on the amplitude of betatron oscillations. The variation is negligible in ordinary particle accelerators with relatively small beam emittance. In an accelerator for large emittance beams like muons and unstable nuclei, however, this effect cannot be ignored. In this study, we measured orbital period in a linear non-scaling fixed-field alternating-gradient accelerator, which is a candidate for muon acceleration, and compared it with the theoretical prediction. The good agreement between them gives important ground for the design of particle accelerators for a new generation of particlemore » and nuclear physics experiments.« less

  17. 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.

  18. Simon van der Meer (1925-2011):. A Modest Genius of Accelerator Science

    NASA Astrophysics Data System (ADS)

    Chohan, Vinod C.

    2011-02-01

    Simon van der Meer was a brilliant scientist and a true giant of accelerator science. His seminal contributions to accelerator science have been essential to this day in our quest for satisfying the demands of modern particle physics. Whether we talk of long base-line neutrino physics or antiproton-proton physics at Fermilab or proton-proton physics at LHC, his techniques and inventions have been a vital part of the modern day successes. Simon van der Meer and Carlo Rubbia were the first CERN scientists to become Nobel laureates in Physics, in 1984. Van der Meer's lesserknown contributions spanned a whole range of subjects in accelerator science, from magnet design to power supply design, beam measurements, slow beam extraction, sophisticated programs and controls.

  19. The Four Lives of a Nuclear Accelerator

    NASA Astrophysics Data System (ADS)

    Wiescher, Michael

    2017-06-01

    Electrostatic accelerators have emerged as a major tool in research and industry in the second half of the twentieth century. In particular in low energy nuclear physics they have been essential for addressing a number of critical research questions from nuclear structure to nuclear astrophysics. This article describes this development on the example of a single machine which has been used for nearly sixty years at the forefront of scientific research in nuclear physics. The article summarizes the concept of electrostatic accelerators and outlines how this accelerator developed from a bare support function to an independent research tool that has been utilized in different research environments and institutions and now looks forward to a new life as part of the experiment CASPAR at the 4,850" level of the Sanford Underground Research Facility.

  20. Where is particle physics going?

    NASA Astrophysics Data System (ADS)

    Ellis, John

    2017-12-01

    The answer to the question in the title is: in search of new physics beyond the Standard Model, for which there are many motivations, including the likely instability of the electroweak vacuum, dark matter, the origin of matter, the masses of neutrinos, the naturalness of the hierarchy of mass scales, cosmological inflation and the search for quantum gravity. So far, however, there are no clear indications about the theoretical solutions to these problems, nor the experimental strategies to resolve them. It makes sense now to prepare various projects for possible future accelerators, so as to be ready for decisions when the physics outlook becomes clearer. Paraphrasing George Harrison, “If you don’t yet know where you’re going, any road may take you there.”

  1. Naked singularities as particle accelerators

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

    Patil, Mandar; Joshi, Pankaj S.

    We investigate here the particle acceleration by naked singularities to arbitrarily high center of mass energies. Recently it has been suggested that black holes could be used as particle accelerators to probe the Planck scale physics. We show that the naked singularities serve the same purpose and probably would do better than their black hole counterparts. We focus on the scenario of a self-similar gravitational collapse starting from a regular initial data, leading to the formation of a globally naked singularity. It is seen that when particles moving along timelike geodesics interact and collide near the Cauchy horizon, the energymore » of collision in the center of mass frame will be arbitrarily high, thus offering a window to Planck scale physics.« less

  2. A QR accelerated volume-to-surface boundary condition for finite element solution of eddy current problems

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

    White, D; Fasenfest, B; Rieben, R

    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 discretizedmore » Biot-Savart law.« less

  3. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator.

    PubMed

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  4. Back to basics: informing the public of co-morbid physical health problems in those with mental illness.

    PubMed

    Ahire, Mrinalini; Sheridan, Judith; Regbetz, Shane; Stacey, Phillip; Scott, James G

    2013-02-01

    Those with mental illness are at increased risk of physical health problems. The current study aimed to examine the information available online to the Australian public about the increased risk and consequences of physical illness in those with mental health problems and the services available to address these co-morbidities. A structured online search was conducted with the search engine Google Australia (www.google.com.au) using generic search terms 'mental health information Australia', 'mental illness information Australia', 'depression', 'anxiety', and 'psychosis'. The direct content of websites was examined for information on the physical co-morbidities of mental illness. All external links on high-profile websites [the first five websites retrieved under each search term (n = 25)] were examined for information pertaining to physical health. Only 4.2% of websites informing the public about mental health contained direct content information about the increased risk of physical co-morbidities. The Australian Government's Department of Health and Ageing site did not contain any information. Of the high-profile websites, 62% had external links to resources about physical health and 55% had recommendations or resources for physical health. Most recommendations were generic. Relative to the seriousness of this problem, there is a paucity of information available to the public about the increased physical health risks associated with mental illness. Improved public awareness is the starting point of addressing this health inequity.

  5. 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…

  6. Multilevel acceleration of scattering-source iterations with application to electron transport

    DOE PAGES

    Drumm, Clif; Fan, Wesley

    2017-08-18

    Acceleration/preconditioning strategies available in the SCEPTRE radiation transport code are described. A flexible transport synthetic acceleration (TSA) algorithm that uses a low-order discrete-ordinates (S N) or spherical-harmonics (P N) solve to accelerate convergence of a high-order S N source-iteration (SI) solve is described. Convergence of the low-order solves can be further accelerated by applying off-the-shelf incomplete-factorization or algebraic-multigrid methods. Also available is an algorithm that uses a generalized minimum residual (GMRES) iterative method rather than SI for convergence, using a parallel sweep-based solver to build up a Krylov subspace. TSA has been applied as a preconditioner to accelerate the convergencemore » of the GMRES iterations. The methods are applied to several problems involving electron transport and problems with artificial cross sections with large scattering ratios. These methods were compared and evaluated by considering material discontinuities and scattering anisotropy. Observed accelerations obtained are highly problem dependent, but speedup factors around 10 have been observed in typical applications.« less

  7. 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…

  8. First-Order Hyperbolic System Method for Time-Dependent Advection-Diffusion Problems

    NASA Technical Reports Server (NTRS)

    Mazaheri, Alireza; Nishikawa, Hiroaki

    2014-01-01

    A time-dependent extension of the first-order hyperbolic system method for advection-diffusion problems is introduced. Diffusive/viscous terms are written and discretized as a hyperbolic system, which recovers the original equation in the steady state. The resulting scheme offers advantages over traditional schemes: a dramatic simplification in the discretization, high-order accuracy in the solution gradients, and orders-of-magnitude convergence acceleration. The hyperbolic advection-diffusion system is discretized by the second-order upwind residual-distribution scheme in a unified manner, and the system of implicit-residual-equations is solved by Newton's method over every physical time step. The numerical results are presented for linear and nonlinear advection-diffusion problems, demonstrating solutions and gradients produced to the same order of accuracy, with rapid convergence over each physical time step, typically less than five Newton iterations.

  9. Dissociative Conceptual and Quantitative Problem Solving Outcomes across Interactive Engagement and Traditional Format Introductory Physics

    ERIC Educational Resources Information Center

    McDaniel, Mark A.; Stoen, Siera M.; Frey, Regina F.; Markow, Zachary E.; Hynes, K. Mairin; Zhao, Jiuqing; Cahill, Michael J.

    2016-01-01

    The existing literature indicates that interactive-engagement (IE) based general physics classes improve conceptual learning relative to more traditional lecture-oriented classrooms. Very little research, however, has examined quantitative problem-solving outcomes from IE based relative to traditional lecture-based physics classes. The present…

  10. Hilbert's sixth problem: between the foundations of geometry and the axiomatization of physics.

    PubMed

    Corry, Leo

    2018-04-28

    The sixth of Hilbert's famous 1900 list of 23 problems was a programmatic call for the axiomatization of the physical sciences. It was naturally and organically rooted at the core of Hilbert's conception of what axiomatization is all about. In fact, the axiomatic method which he applied at the turn of the twentieth century in his famous work on the foundations of geometry originated in a preoccupation with foundational questions related with empirical science in general. Indeed, far from a purely formal conception, Hilbert counted geometry among the sciences with strong empirical content, closely related to other branches of physics and deserving a treatment similar to that reserved for the latter. In this treatment, the axiomatization project was meant to play, in his view, a crucial role. Curiously, and contrary to a once-prevalent view, from all the problems in the list, the sixth is the only one that continually engaged Hilbet's efforts over a very long period of time, at least between 1894 and 1932.This article is part of the theme issue 'Hilbert's sixth problem'. © 2018 The Author(s).

  11. Hilbert's sixth problem: between the foundations of geometry and the axiomatization of physics

    NASA Astrophysics Data System (ADS)

    Corry, Leo

    2018-04-01

    The sixth of Hilbert's famous 1900 list of 23 problems was a programmatic call for the axiomatization of the physical sciences. It was naturally and organically rooted at the core of Hilbert's conception of what axiomatization is all about. In fact, the axiomatic method which he applied at the turn of the twentieth century in his famous work on the foundations of geometry originated in a preoccupation with foundational questions related with empirical science in general. Indeed, far from a purely formal conception, Hilbert counted geometry among the sciences with strong empirical content, closely related to other branches of physics and deserving a treatment similar to that reserved for the latter. In this treatment, the axiomatization project was meant to play, in his view, a crucial role. Curiously, and contrary to a once-prevalent view, from all the problems in the list, the sixth is the only one that continually engaged Hilbet's efforts over a very long period of time, at least between 1894 and 1932. This article is part of the theme issue `Hilbert's sixth problem'.

  12. 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…

  13. Elementary particle physics

    NASA Technical Reports Server (NTRS)

    Perkins, D. H.

    1986-01-01

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

  14. Pathways maintaining physical health problems from childhood to young adulthood: The role of stress and mood

    PubMed Central

    Hammen, Constance L.; Brennan, Patricia A; Najman, Jake M.

    2016-01-01

    Objective Poor physical health in childhood is associated with a variety of negative health-related outcomes in adulthood. Psychosocial pathways contributing to the maintenance of physical health problems from childhood to young adulthood remain largely unexamined, despite evidence that factors such as negative mood and stress impact physical health. Design The current study tested the direct and indirect effects of ongoing health, chronic stress, health-related chronic stress, and depressive symptoms at age 20 on the link between health problems in childhood and young adulthood (age 21) in a longitudinal sample (n = 384). Main Outcome Measures The hypotheses were tested using a multiple mediation path analysis framework; the primary outcome measure was a composite index of health status markers in young adulthood. Results The proposed model provided an adequate fit for the data, with significant total indirect effects of the four mediators and significant specific indirect effects of health-related chronic stress and depressive symptoms in maintaining health problems from childhood into young adulthood. Conclusions Health problems are maintained from early childhood into young adulthood in part through psychosocial mechanisms. Depressive symptoms and health-related chronic stress have significant, unique effects on the relationship between health problems in early childhood and young adulthood. PMID:27329508

  15. Stochastic first passage time accelerated with CUDA

    NASA Astrophysics Data System (ADS)

    Pierro, Vincenzo; Troiano, Luigi; Mejuto, Elena; Filatrella, Giovanni

    2018-05-01

    The numerical integration of stochastic trajectories to estimate the time to pass a threshold is an interesting physical quantity, for instance in Josephson junctions and atomic force microscopy, where the full trajectory is not accessible. We propose an algorithm suitable for efficient implementation on graphical processing unit in CUDA environment. The proposed approach for well balanced loads achieves almost perfect scaling with the number of available threads and processors, and allows an acceleration of about 400× with a GPU GTX980 respect to standard multicore CPU. This method allows with off the shell GPU to challenge problems that are otherwise prohibitive, as thermal activation in slowly tilted potentials. In particular, we demonstrate that it is possible to simulate the switching currents distributions of Josephson junctions in the timescale of actual experiments.

  16. Particle acceleration on a chip: A laser-driven micro-accelerator for research and industry

    NASA Astrophysics Data System (ADS)

    Yoder, R. B.; Travish, G.

    2013-03-01

    Particle accelerators are conventionally built from radio-frequency metal cavities, but this technology limits the maximum energy available and prevents miniaturization. In the past decade, laser-powered acceleration has been intensively studied as an alternative technology promising much higher accelerating fields in a smaller footprint and taking advantage of recent advances in photonics. Among the more promising approaches are those based on dielectric field-shaping structures. These ``dielectric laser accelerators'' (DLAs) scale with the laser wavelength employed and can be many orders of magnitude smaller than conventional accelerators; DLAs may enable the production of high-intensity, ultra-short relativistic electron bunches in a chip-scale device. When combined with a high- Z target or an optical-period undulator, these systems could produce high-brilliance x-rays from a breadbox-sized device having multiple applications in imaging, medicine, and homeland security. In our research program we have developed one such DLA, the Micro-Accelerator Platform (MAP). We describe the fundamental physics, our fabrication and testing program, and experimental results to date, along with future prospects for MAP-based light-sources and some remaining challenges. Supported in part by the Defense Threat Reduction Agency and National Nuclear Security Administration.

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

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

    Mocker, Anna; Bugiel, Sebastian; Srama, Ralf

    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-flightmore » 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

  18. TEACHING PHYSICS: Atwood's machine: experiments in an accelerating frame

    NASA Astrophysics Data System (ADS)

    Teck Chee, Chia; Hong, Chia Yee

    1999-03-01

    Experiments in an accelerating frame are often difficult to perform, but simple computer software allows sufficiently rapid and accurate measurements to be made on an arrangement of weights and pulleys known as Atwood's machine.

  19. Routes for the production of isotopes for PET with high intensity deuteron accelerators

    NASA Astrophysics Data System (ADS)

    Arias de Saavedra, F.; Porras, I.; Praena, J.

    2018-04-01

    Recent advances in accelerator science are opening new possibilities in different fields of physics. In particular, the development of compact linear accelerators that can provide charged particles of low-medium energy (few MeV) with high current (above mA) allows for the study of new possibilities in neutron production and for new routes for the production of radioisotopes. Keeping in mind how radioisotopes are actually produced in dedicated facilities, we have performed a study of alternative reactions to produce PET isotopes induced by low-energy deuterons. We have fitted the EXFOR cross sections data, used the fitted values of the stopping power by Andersen and Ziegler and calculated by numerical integration the production rate of isotopes for charged particles up to 20 MeV. The results for deuterons up to 3 MeV are compared with the ones from cyclotrons, which are able to provide higher energies to the charged projectiles but with lower intensities. Our results indicate that using linear accelerators may be a good alternative for producing PET isotopes, reducing the problem of neutron activation.

  20. Beamlets from stochastic acceleration

    NASA Astrophysics Data System (ADS)

    Perri, Silvia; Carbone, Vincenzo

    2008-09-01

    We investigate the dynamics of a realization of the stochastic Fermi acceleration mechanism. The model consists of test particles moving between two oscillating magnetic clouds and differs from the usual Fermi-Ulam model in two ways. (i) Particles can penetrate inside clouds before being reflected. (ii) Particles can radiate a fraction of their energy during the process. Since the Fermi mechanism is at work, particles are stochastically accelerated, even in the presence of the radiated energy. Furthermore, due to a kind of resonance between particles and oscillating clouds, the probability density function of particles is strongly modified, thus generating beams of accelerated particles rather than a translation of the whole distribution function to higher energy. This simple mechanism could account for the presence of beamlets in some space plasma physics situations.

  1. Accelerated Hydrolysis of Aspirin Using Alternating Magnetic Fields

    NASA Astrophysics Data System (ADS)

    Reinscheid, Uwe M.

    2009-08-01

    The major problem of current drug-based therapy is selectivity. As in other areas of science, a combined approach might improve the situation decisively. The idea is to use the pro-drug principle together with an alternating magnetic field as physical stimulus, which can be applied in a spatially and temporarily controlled manner. As a proof of principle, the neutral hydrolysis of aspirin in physiological phosphate buffer of pH 7.5 at 40 °C was chosen. The sensor and actuator system is a commercially available gold nanoparticle (NP) suspension which is approved for animal usage, stable in high concentrations and reproducibly available. Applying the alternating magnetic field of a conventional NMR magnet system accelerated the hydrolysis of aspirin in solution.

  2. The Los Alamos Laser Acceleration of Particles Workshop and beginning of the advanced accelerator concepts field

    NASA Astrophysics Data System (ADS)

    Joshi, C.

    2012-12-01

    The first Advanced Acceleration of Particles-AAC-Workshop (actually named Laser Acceleration of Particles Workshop) was held at Los Alamos in January 1982. The workshop lasted a week and divided all the acceleration techniques into four categories: near field, far field, media, and vacuum. Basic theorems of particle acceleration were postulated (later proven) and specific experiments based on the four categories were formulated. This landmark workshop led to the formation of the advanced accelerator R&D program in the HEP office of the DOE that supports advanced accelerator research to this day. Two major new user facilities at Argonne and Brookhaven and several more directed experimental efforts were built to explore the advanced particle acceleration schemes. It is not an exaggeration to say that the intellectual breadth and excitement provided by the many groups who entered this new field provided the needed vitality to then recently formed APS Division of Beams and the new online journal Physical Review Special Topics-Accelerators and Beams. On this 30th anniversary of the AAC Workshops, it is worthwhile to look back at the legacy of the first Workshop at Los Alamos and the fine groundwork it laid for the field of advanced accelerator concepts that continues to flourish to this day.

  3. No Issue, No Problem? Co-Education in Dutch Secondary Physical Education during the Twentieth Century.

    ERIC Educational Resources Information Center

    Van Essen, Mineke

    2003-01-01

    Examines the development co-education in Dutch secondary physical education, suggesting that the dominant 20th century co-educational tradition in the Netherlands has influenced educational ideals and school practice with respect to physical education. Asserts that a historical lack of discussions about co-education trivializes today's problems in…

  4. High gradient tests of metallic mm-wave accelerating structures

    DOE PAGES

    Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; ...

    2017-05-10

    This study explores the physics of vacuum rf breakdowns in high gradient mm-wave accelerating structures. We performed a series of experiments with 100 GHz and 200 GHz metallic accelerating structures, at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. This paper presents the experimental results of rf tests of 100 GHz travelling-wave accelerating structures, made of hard copper-silver alloy. The results are compared with pure hard copper structures. The rf fields were excited by the FACET ultra-relativistic electron beam. The accelerating structures have open geometries, 10 cm long, composed of two halves separated bymore » a variable gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 90 GHz to 140 GHz. The measured frequency and pulse length are consistent with our simulations. When the beam travels off-axis, a deflecting field is induced in addition to the decelerating longitudinal field. We measured the deflecting forces by observing the displacement of the electron bunch and used this measurement to verify the expected accelerating gradient. We present the first quantitative measurement of rf breakdown rates in 100 GHz copper-silver accelerating structure, which was 10 –3 per pulse, with peak electric field of 0.42 GV/m, an accelerating gradient of 127 MV/m, at a pulse length of 2.3 ns. The goal of our studies is to understand the physics of gradient limitations in order to increase the energy reach of future accelerators.« less

  5. High gradient tests of metallic mm-wave accelerating structures

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

    Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon

    This study explores the physics of vacuum rf breakdowns in high gradient mm-wave accelerating structures. We performed a series of experiments with 100 GHz and 200 GHz metallic accelerating structures, at the Facility for Advanced Accelerator Experimental Tests (FACET) at the SLAC National Accelerator Laboratory. This paper presents the experimental results of rf tests of 100 GHz travelling-wave accelerating structures, made of hard copper-silver alloy. The results are compared with pure hard copper structures. The rf fields were excited by the FACET ultra-relativistic electron beam. The accelerating structures have open geometries, 10 cm long, composed of two halves separated bymore » a variable gap. The rf frequency of the fundamental accelerating mode depends on the gap size and can be changed from 90 GHz to 140 GHz. The measured frequency and pulse length are consistent with our simulations. When the beam travels off-axis, a deflecting field is induced in addition to the decelerating longitudinal field. We measured the deflecting forces by observing the displacement of the electron bunch and used this measurement to verify the expected accelerating gradient. We present the first quantitative measurement of rf breakdown rates in 100 GHz copper-silver accelerating structure, which was 10 –3 per pulse, with peak electric field of 0.42 GV/m, an accelerating gradient of 127 MV/m, at a pulse length of 2.3 ns. The goal of our studies is to understand the physics of gradient limitations in order to increase the energy reach of future accelerators.« less

  6. 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…

  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. Time to Completion of Web-Based Physics Problems with Tutoring

    PubMed Central

    Warnakulasooriya, Rasil; Palazzo, David J; Pritchard, David E

    2007-01-01

    We studied students performing a complex learning task, that of solving multipart physics problems with interactive tutoring on the web. We extracted the rate of completion and fraction completed as a function of time on task by retrospectively analyzing the log of student–tutor interactions. There was a spontaneous division of students into three groups, the central (and largest) group (about 65% of the students) being those who solved the problem in real time after multiple interactions with the tutorial program (primarily receiving feedback to submitted wrong answers and requesting hints). This group displayed a sigmoidal fraction-completed curve as a function of logarithmic time. The sigmoidal shape is qualitatively flatter for problems that do not include hints and wrong-answer responses. We argue that the group of students who respond quickly (about 10% of the students) is obtaining the answer from some outside source. The third group (about 25% of the students) represents those who interrupt their solution, presumably to work offline or to obtain outside help. PMID:17725054

  9. Family Violence and Children’s Behavior Problems: Independent Contributions of Intimate Partner and Child-Directed Physical Aggression

    PubMed Central

    Gustafsson, Hanna C.; Barnett, Melissa A.; Towe-Goodman, Nissa R.; Mills-Koonce, W. Roger; Cox, Martha J.

    2014-01-01

    Using data from a diverse sample of 581 families living in predominantly low-income, rural communities, the current study sought to investigate the longitudinal associations among father-perpetrated intimate partner violence (IPV) and child-directed physical aggression perpetrated by the mother. The unique contributions of each of these types of family violence on children’s behavioral problems at school entry were also examined. Results confirm bidirectional associations between father-perpetrated IPV and maternal physical aggression directed toward the child, and indicate that both types of physical aggression contribute to child behavior problems at school entry. PMID:25431522

  10. 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…

  11. Do mental health problems in childhood predict chronic physical conditions among males in early adulthood? Evidence from a community-based prospective study.

    PubMed

    Goodwin, R D; Sourander, A; Duarte, C S; Niemelä, S; Multimäki, P; Nikolakaros, G; Helenius, H; Piha, J; Kumpulainen, K; Moilanen, I; Tamminen, T; Almqvist, F

    2009-02-01

    Previous studies have documented associations between mental and physical health problems in cross-sectional studies, yet little is known about these relationships over time or the specificity of these associations. The aim of the current study was to examine the relationship between mental health problems in childhood at age 8 years and physical disorders in adulthood at ages 18-23 years. Multiple logistic regression analyses were used to examine the relationship between childhood mental health problems, reported by child, parent and teacher, and physical disorders diagnosed by a physician in early adulthood. Significant linkages emerged between childhood mental health problems and obesity, atopic eczema, epilepsy and asthma in early adulthood. Specifically, conduct problems in childhood were associated with a significantly increased likelihood of obesity and atopic eczema; emotional problems were associated with an increased likelihood of epilepsy and asthma; and depression symptoms at age 8 were associated with an increased risk of asthma in early adulthood. Our findings provide the first evidence of an association between mental health problems during childhood and increased risk of specific physical health problems, mainly asthma and obesity, during early adulthood, in a representative sample of males over time. These data suggest that behavioral and emotional problems in childhood may signal vulnerability to chronic physical health problems during early adulthood.

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

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

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

    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 quadraturemore » 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)« less

  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. The Role of Substorms in Storm-time Particle Acceleration

    NASA Astrophysics Data System (ADS)

    Daglis, Ioannis A.; Kamide, Yohsuke

    The terrestrial magnetosphere has the capability to rapidly accelerate charged particles up to very high energies over relatively short times and distances. Acceleration of charged particles is an essential ingredient of both magnetospheric substorms and space storms. In the case of space storms, the ultimate result is a bulk flow of electric charge through the inner magnetosphere, commonly known as the ring current. Syun-Ichi Akasofu and Sydney Chapman, two of the early pioneers in space physics, postulated that the bulk acceleration of particles during storms is rather the additive result of partial acceleration during consecutive substorms. This paradigm has been heavily disputed during recent years. The new case is that substorm acceleration may be sufficient to produce individual high-energy particles that create auroras and possibly harm spacecraft, but it cannot produce the massive acceleration that constitutes a storm. This paper is a critical review of the long-standing issue of the storm-substorm relationship, or—in other words—the capability or necessity of substorms in facilitating or driving the build-up of the storm-time ring current. We mainly address the physical effect itself, i.e. the bulk acceleration of particles, and not the diagnostic of the process, i.e. the Dst index, which is rather often the case. Within the framework of particle acceleration, substorms retain their storm-importance due to the potential of substorm-induced impulsive electric fields in obtaining the massive ion acceleration needed for the storm-time ring current buildup.

  15. Effects of a Problem-based Structure of Physics Contents on Conceptual Learning and the Ability to Solve Problems

    NASA Astrophysics Data System (ADS)

    Becerra-Labra, Carlos; Gras-Martí, Albert; Martínez Torregrosa, Joaquín

    2012-05-01

    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 undergraduates taking physics. A number of tests and questionnaires were administered to a group of students following a traditional lecture-based instruction, as well as to another group that was following an instruction scheme based on the proposed approach and the teaching materials developed ad hoc. The results show that students following the new method can develop scientific reasoning habits in problem-solving skills, and show gains in conceptual learning, attitudes and interests, and that the effects of this approach on learning are noticeable several months after the course is over.

  16. Accelerated observers and the notion of singular spacetime

    NASA Astrophysics Data System (ADS)

    Olmo, Gonzalo J.; Rubiera-Garcia, Diego; Sanchez-Puente, Antonio

    2018-03-01

    Geodesic completeness is typically regarded as a basic criterion to determine whether a given spacetime is regular or singular. However, the principle of general covariance does not privilege any family of observers over the others and, therefore, observers with arbitrary motions should be able to provide a complete physical description of the world. This suggests that in a regular spacetime, all physically acceptable observers should have complete paths. In this work we explore this idea by studying the motion of accelerated observers in spherically symmetric spacetimes and illustrate it by considering two geodesically complete black hole spacetimes recently described in the literature. We show that for bound and locally unbound accelerations, the paths of accelerated test particles are complete, providing further support to the regularity of such spacetimes.

  17. 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…

  18. Operational and design aspects of accelerators for medical applications

    NASA Astrophysics Data System (ADS)

    Schippers, Jacobus Maarten; Seidel, Mike

    2015-03-01

    Originally, the typical particle accelerators as well as their associated beam transport equipment were designed for particle and nuclear physics research and applications in isotope production. In the past few decades, such accelerators and related equipment have also been applied for medical use. This can be in the original physics laboratory environment, but for the past 20 years also in hospital-based or purely clinical environments for particle therapy. The most important specific requirements of accelerators for radiation therapy with protons or ions will be discussed. The focus will be on accelerator design, operational, and formal aspects. We will discuss the special requirements to reach a high reliability for patient treatments as well as an accurate delivery of the dose at the correct position in the patient using modern techniques like pencil beam scanning. It will be shown that the technical requirements, safety aspects, and required reliability of the accelerated beam differ substantially from those in a nuclear physics laboratory. It will be shown that this difference has significant implications on the safety and interlock systems. The operation of such a medical facility should be possible by nonaccelerator specialists at different operating sites (treatment rooms). The organization and role of the control and interlock systems can be considered as being the most crucially important issue, and therefore a special, dedicated design is absolutely necessary in a facility providing particle therapy.

  19. REVIEWS OF TOPICAL PROBLEMS: Contemporary status and prospects of high-energy physics

    NASA Astrophysics Data System (ADS)

    Okun', Lev B.

    1981-05-01

    A concise review of the most recent major achievements of elementary-particle physics is given. The successes and problems of gauge theories of the strong and electroweak interactions are discussed. A comparison is made of the possible alternatives in the development of physics in the transition to laboratory energies of the order of a tera-electron-volt. Models of grand unification and superunification of the various types of fundamental interactions are considered. A number of examples are used to demonstrate the connection between the properties of elementary particles and the properties of astronomical objects and of the Universe as a whole.

  20. Disciplinary Knots and Learning Problems in Waves Physics

    NASA Astrophysics Data System (ADS)

    Di Renzone, Simone; Frati, Serena; Montalbano, Vera

    An investigation on student understanding of waves is performed during an optional laboratory realized in informal extracurricular way with few, interested and talented pupils. The background and smart intuitions of students rendered the learning path very dynamic and ambitious. The activities started by investigating the basic properties of waves by means of a Shive wave machine. In order to make quantitative observed phenomena, the students used a camcorder and series of measures were obtained from the captured images. By checking the resulting data, it arose some learning difficulties especially in activities related to the laboratory. This experience was the starting point for a further analysis on disciplinary knots and learning problems in the physics of waves in order to elaborate a teaching-learning proposal on this topic.

  1. The roles of emotional competence and social problem-solving in the relationship between physical abuse and adolescent suicidal ideation in China.

    PubMed

    Kwok, Sylvia Y C L; Yeung, Jerf W K; Low, Andrew Y T; Lo, Herman H M; Tam, Cherry H L

    2015-06-01

    The study investigated the relationship among physical abuse, positive psychological factors including emotional competence and social problem-solving, and suicidal ideation among adolescents in China. The possible moderating effects of emotional competence and social problem-solving in the association between physical abuse and adolescent suicidal ideation were also studied. A cross-sectional survey employing convenience sampling was conducted and self-administered questionnaires were collected from 527 adolescents with mean age of 14 years from the schools in Shanghai. Results showed that physical abuse was significantly and positively related to suicidal ideation in both male and female adolescents. Emotional competence was not found to be significantly associated with adolescent suicidal ideation, but rational problem-solving, a sub-scale of social problem-solving, was shown to be significantly and negatively associated with suicidal ideation for males, but not for females. However, emotional competence and rational problem-solving were shown to be a significant and a marginally significant moderator in the relationship between physical abuse and suicidal ideation in females respectively, but not in males. High rational problem-solving buffered the negative impact of physical abuse on suicidal ideation for females. Interestingly, females with higher empathy and who reported being physically abused by their parents have higher suicidal ideation. Findings are discussed and implications are stated. It is suggested to change the attitudes of parents on the concept of physical abuse, guide them on appropriate attitudes, knowledge and skills in parenting, and enhance adolescents' skills in rational problem-solving. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Theoretical model to explain the problem-solving process in physics

    NASA Astrophysics Data System (ADS)

    Lopez, Carlos

    2011-03-01

    This work reports a theoretical model developed with the aim to explain the mental mechanisms of knowledge building during the problem-solving process in physics using a hybrid approach of assimilation- formation of concepts. The model has been termed conceptual chains and represents graphic diagrams of conceptual dependency, which have yielded information about the background knowledge required during the learning process, as well as about the formation of diverse structures that correspond to distinct forms of networking concepts Additionally, the conceptual constructs of the model have been classified according to five types of knowledge. Evidence was found about the influence of these structures, as well as of the distinct types of knowledge about the degree of difficulty of the problems. I want to be grateful to Laureate International Universities, Baltimore M.D., USA, for the financing granted for the accomplishment of this work.

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

    DOE PAGES

    Rubinstein, Roy

    2016-12-14

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

  4. 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). © 2014 Wiley Publishing Asia Pty Ltd.

  5. Children at risk of residual physical problems after public road traffic injuries--a 1-year follow-up study.

    PubMed

    Olofsson, Eva; Bunketorp, Olle; Andersson, Anna-Lena

    2012-01-01

    To describe the residual physical problems 1 year after traffic injuries in children with respect to age, gender, extraction (Swedish or foreign), type of care, type of accident and use of protective equipment, type of injury, and the impact on daily living activities. Hospital data were analysed for children, aged 15 or under, after road traffic accidents in the Gothenburg region in 2000. Age, gender, type of road user, counterpart, use of protective equipment, type and severity of each injury, and type of care were related to follow-up data obtained by a self-completed questionnaire answered 1 year after the accident. The AIS90 was used for injury classification. Residual physical problems were specified, graded, and mapped on anatomical pictures of the body by the respondents. Logistic regression was used to explore independent factors for residual problems. A total of 341 children (81%) fulfilled the study. Cyclists dominated, 60%, followed by moped users, car occupants and pedestrians. The mean age was 11 years, 61% were boys, 16% were of foreign extraction, 26% were treated as inpatients, and 11% had at least one serious (AIS3+) injury. Residual problems were reported for 16% of the study group (n=53), and of these 31% were located to the lower extremities (mostly knee problems), upper extremities in 20%, face in 14%, neck in 14%, upper trunk in 8%, lower trunk in 8%, and skull/brain in 3%. Significant permanent impairment was reported in one case. Cyclists reported problems significantly less frequently than others. Children reporting problems tended to be older and were most often injured as moped users. Problems to the neck and the upper trunk were reported to a higher rate than the injury rate in these regions. Children with residual problems reported limitations in daily living activities after the accident more often than those without residual physical problems. Residual physical problems were reported in about one sixth of the study group, few with

  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. Ashra Neutrino Telescope Array (NTA): Combined Imaging Observation of Astroparticles — For Clear Identification of Cosmic Accelerators and Fundamental Physics Using Cosmic Beams —

    NASA Astrophysics Data System (ADS)

    Sasaki, Makoto; Kifune, Tadashi

    In VHEPA (very high energy particle astronomy) 2014 workshop, focused on the next generation explorers for the origin of cosmic rays, held in Kashiwa, Japan, reviewing and discussions were presented on the status of the observation of GeV-TeV photons, TeV-PeV neutrinos, EeV-ZeV hadrons, test of interaction models with Large Hadron Collider (LHC), and theoretical aspects of astrophysics. The acceleration sites of hadrons, i.e., sources of PeV-EeV cosmic rays, should exist in the universe within the GZK-horizon even in the remotest case. We also affirmed that the hadron acceleration mechanism correlates with cosmic ray composition so that it is important to investigate the acceleration mechanism in relevance to the composition survey at PeV-EeV energy. We regard that LHC and astrophysics theories are ready to be used to probe into hadron acceleration mechanism in the universe. Recently, IceCube has reported detection of three events of neutrinos with energies around 1 PeV and additional events at lower energies, which significantly deviate from the expected level of background events. It is necessary to observe GeV-TeV photon, EeV-ZeV hadron and TeV-PeV neutrino all together, in order to understand hadronic interactions of cosmic rays in the PeV-EeV energy region. It is required to make a step further toward exploring the PeV-EeV universe with high accuracy and high statistics observations for both neutrinos and gamma rays simultaneously, by using the instrument such as Ashra Neutrino Telescope Array (NTA). Wide and fine survey of gamma-rays and neutrinos with simultaneously detecting Cherenkov and fluorescence light with NTA will guide us to a new intriguing stage of recognizing astronomical objects and non-thermal phenomena in ultra-high energy region, in addition, new aspect about the fundamental concepts of physics beyond our presently limited understanding; the longstanding problem of cosmic ray origin, the radiation mechanism of gamma-rays, neutrino and

  8. 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…

  9. Methods of geometrical integration in accelerator physics

    NASA Astrophysics Data System (ADS)

    Andrianov, S. N.

    2016-12-01

    In the paper we consider a method of geometric integration for a long evolution of the particle beam in cyclic accelerators, based on the matrix representation of the operator of particles evolution. This method allows us to calculate the corresponding beam evolution in terms of two-dimensional matrices including for nonlinear effects. The ideology of the geometric integration introduces in appropriate computational algorithms amendments which are necessary for preserving the qualitative properties of maps presented in the form of the truncated series generated by the operator of evolution. This formalism extends both on polarized and intense beams. Examples of practical applications are described.

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

    PubMed

    Gramfort, Alexandre; Kowalski, Matthieu; Hämäläinen, Matti

    2012-04-07

    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.

  11. 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

  12. 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'…

  13. Neurons compute internal models of the physical laws of motion.

    PubMed

    Angelaki, Dora E; Shaikh, Aasef G; Green, Andrea M; Dickman, J David

    2004-07-29

    A critical step in self-motion perception and spatial awareness is the integration of motion cues from multiple sensory organs that individually do not provide an accurate representation of the physical world. One of the best-studied sensory ambiguities is found in visual processing, and arises because of the inherent uncertainty in detecting the motion direction of an untextured contour moving within a small aperture. A similar sensory ambiguity arises in identifying the actual motion associated with linear accelerations sensed by the otolith organs in the inner ear. These internal linear accelerometers respond identically during translational motion (for example, running forward) and gravitational accelerations experienced as we reorient the head relative to gravity (that is, head tilt). Using new stimulus combinations, we identify here cerebellar and brainstem motion-sensitive neurons that compute a solution to the inertial motion detection problem. We show that the firing rates of these populations of neurons reflect the computations necessary to construct an internal model representation of the physical equations of motion.

  14. Problems in particle theory. Technical report - 1993--1994

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

    Adler, S.L.; Wilczek, F.

    This report is a progress report on the work of two principal investigators in the broad area of particle physics theory, covering their personal work, that of their coworkers, and their proposed work for the future. One author has worked in the past on various topics in field theory and particle physics, among them current algebras, the physics of neutrino induced reactions, quantum electrodynamics (including strong magnetic field processes), the theory of the axial-vector current anomaly, topics in quantum gravity, and nonlinear models for quark confinement. While much of his work has been analytical, all of the projects listed abovemore » (except for the work on gravity) had phases which required considerable computer work as well. Over the next several years, he proposes to continue or initiate research on the following problems: (1) Acceleration algorithms for the Monte Carlo analysis of lattice field and gauge theories, and more generally, new research in computational neuroscience and pattern recognition. (2) Construction of quaternionic generalizations of complex quantum mechanics and field theory, and their application to composite models of quarks and leptons, and to the problem of unifying quantum theories of matter with general relativity. One author has worked on problems in exotic quantum statistics and its applications to condensed matter systems. His work has also continued on the quantum theory of black holes. This has evolved toward understanding properties of quantum field theory and string theory in incomplete regions of flat space.« less

  15. Accelerated testing of space batteries

    NASA Technical Reports Server (NTRS)

    Mccallum, J.; Thomas, R. E.; Waite, J. H.

    1973-01-01

    An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.

  16. Laboratory laser acceleration and high energy astrophysics: {gamma}-ray bursts and cosmic rays

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

    Tajima, T.; Takahashi, Y.

    1998-08-20

    Recent experimental progress in laser acceleration of charged particles (electrons) and its associated processes has shown that intense electromagnetic pulses can promptly accelerate charged particles to high energies and that their energy spectrum is quite hard. On the other hand some of the high energy astrophysical phenomena such as extremely high energy cosmic rays and energetic components of {gamma}-ray bursts cry for new physical mechanisms for promptly accelerating particles to high energies. The authors suggest that the basic physics involved in laser acceleration experiments sheds light on some of the underlying mechanisms and their energy spectral characteristics of the promptlymore » accelerated particles in these high energy astrophysical phenomena.« less

  17. SuperB Progress Report for Accelerator

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

    Biagini, M.E.; Boni, R.; Boscolo, M.

    2012-02-14

    This report details the progress made in by the SuperB Project in the area of the Collider since the publication of the SuperB Conceptual Design Report in 2007 and the Proceedings of SuperB Workshop VI in Valencia in 2008. With this document we propose a new electron positron colliding beam accelerator to be built in Italy to study flavor physics in the B-meson system at an energy of 10 GeV in the center-of-mass. This facility is called a high luminosity B-factory with a project name 'SuperB'. This project builds on a long history of successful e+e- colliders built around themore » world, as illustrated in Figure 1.1. The key advances in the design of this accelerator come from recent successes at the DAFNE collider at INFN in Frascati, Italy, at PEP-II at SLAC in California, USA, and at KEKB at KEK in Tsukuba Japan, and from new concepts in beam manipulation at the interaction region (IP) called 'crab waist'. This new collider comprises of two colliding beam rings, one at 4.2 GeV and one at 6.7 GeV, a common interaction region, a new injection system at full beam energies, and one of the two beams longitudinally polarized at the IP. Most of the new accelerator techniques needed for this collider have been achieved at other recently completed accelerators including the new PETRA-3 light source at DESY in Hamburg (Germany) and the upgraded DAFNE collider at the INFN laboratory at Frascati (Italy), or during design studies of CLIC or the International Linear Collider (ILC). The project is to be designed and constructed by a worldwide collaboration of accelerator and engineering staff along with ties to industry. To save significant construction costs, many components from the PEP-II collider at SLAC will be recycled and used in this new accelerator. The interaction region will be designed in collaboration with the particle physics detector to guarantee successful mutual use. The accelerator collaboration will consist of several groups at present universities and

  18. PHYSICS OF OUR DAYS Physical conditions in potential accelerators of ultra-high-energy cosmic rays: updated Hillas plot and radiation-loss constraints

    NASA Astrophysics Data System (ADS)

    Ptitsyna, Kseniya V.; Troitsky, Sergei V.

    2010-10-01

    We review basic constraints on the acceleration of ultra-high-energy (UHE) cosmic rays (CRs) in astrophysical sources, namely, the geometric (Hillas) criterion and the restrictions from radiation losses in different acceleration regimes. Using the latest available astrophysical data, we redraw the Hillas plot and find potential UHECR accelerators. For the acceleration in the central engines of active galactic nuclei, we constrain the maximal UHECR energy for a given black hole mass. Among active galaxies, only the most powerful ones, radio galaxies and blazars, are able to accelerate protons to UHE, although acceleration of heavier nuclei is possible in much more abundant lower-power Seyfert galaxies.

  19. Ion Beam Facilities at the National Centre for Accelerator based Research using a 3 MV Pelletron Accelerator

    NASA Astrophysics Data System (ADS)

    Trivedi, T.; Patel, Shiv P.; Chandra, P.; Bajpai, P. K.

    A 3.0 MV (Pelletron 9 SDH 4, NEC, USA) low energy ion accelerator has been recently installed as the National Centre for Accelerator based Research (NCAR) at the Department of Pure & Applied Physics, Guru Ghasidas Vishwavidyalaya, Bilaspur, India. The facility is aimed to carried out interdisciplinary researches using ion beams with high current TORVIS (for H, He ions) and SNICS (for heavy ions) ion sources. The facility includes two dedicated beam lines, one for ion beam analysis (IBA) and other for ion implantation/ irradiation corresponding to switching magnet at +20 and -10 degree, respectively. Ions with 60 kV energy are injected into the accelerator tank where after stripping positively charged ions are accelerated up to 29 MeV for Au. The installed ion beam analysis techniques include RBS, PIXE, ERDA and channelling.

  20. Fermilab | Science | Particle Accelerators

    Science.gov Websites

    2,300 physicists from all over the world come to Fermilab to conduct experiments using particle particle physics to the next level, collaborating with scientists and laboratories around the world to help world leader in accelerator research, development and industrialization. Learn more about IARC. Fermilab

  1. Analyzing Collision Processes with the Smartphone Acceleration Sensor

    ERIC Educational Resources Information Center

    Vogt, Patrik; Kuhn, Jochen

    2014-01-01

    It has been illustrated several times how the built-in acceleration sensors of smartphones can be used gainfully for quantitative experiments in school and university settings (see the overview in Ref. 1 ). The physical issues in that case are manifold and apply, for example, to free fall, radial acceleration, several pendula, or the exploitation…

  2. The Bonn Electron Stretcher Accelerator ELSA: Past and future

    NASA Astrophysics Data System (ADS)

    Hillert, W.

    2006-05-01

    In 1953, it was decided to build a 500MeV electron synchrotron in Bonn. It came into operation 1958, being the first alternating gradient synchrotron in Europe. After five years of performing photoproduction experiments at this accelerator, a larger 2.5GeV electron synchrotron was built and set into operation in 1967. Both synchrotrons were running for particle physics experiments, until from 1982 to 1987 a third accelerator, the electron stretcher ring ELSA, was constructed and set up in a separate ring tunnel below the physics institute. ELSA came into operation in 1987, using the pulsed 2.5GeV synchrotron as pre-accelerator. ELSA serves either as storage ring producing synchrotron radiation, or as post-accelerator and pulse stretcher. Applying a slow extraction close to a third integer resonance, external electron beams with energies up to 3.5GeV and high duty factors are delivered to hadron physics experiments. Various photo- and electroproduction experiments, utilising the experimental set-ups PHOENICS, ELAN, SAPHIR, GDH and Crystal Barrel have been carried out. During the late 90's, a pulsed GaAs source of polarised electrons was constructed and set up at the accelerator. ELSA was upgraded in order to accelerate polarised electrons, compensating for depolarising resonances by applying the methods of fast tune jumping and harmonic closed orbit correction. With the experimental investigation of the GDH sum rule, the first experiment requiring a polarised beam and a polarised target was successfully performed at the accelerator. In the near future, the stretcher ring will be further upgraded to increase polarisation and current of the external electron beams. In addition, the aspects of an increase of the maximum energy to 5GeV using superconducting resonators will be investigated.

  3. The free fall of an apple: conceptual subtleties and implications for physics teaching

    NASA Astrophysics Data System (ADS)

    Assis, A. K. T.; Karam, R. A. S.

    2018-05-01

    The study of free fall is thoroughly present in physics teaching at all levels. From the point of view of Newtonian dynamics it appears to be extremely simple, as it consists of a two-body problem with a constant force generating a constant acceleration. However, there are several important conceptual subtleties and hidden assumptions involved in this problem, which are rarely discussed in educational settings. In this work we present some of these subtleties and argue that explicitly addressing them has significant pedagogical benefits.

  4. 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.

  5. 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.…

  6. Global problems in magnetospheric plasma physics and prospects for their solution

    NASA Technical Reports Server (NTRS)

    Roederer, J. G.

    1977-01-01

    Selected problems in magnetospheric plasma physics are critically reviewed. The discussion is restricted to questions that are 'global' in nature (i.e., involve the magnetosphere as a whole) and that are beyond the stage of systematic survey or isolated study requirements. Only low-energy particle aspects are discussed. The article focuses on the following subjects: (1) the effect of the interplanetary magnetic field on the topography, topology, and stability of the magnetospheric boundary; (2) solar-wind plasma entry into the magnetosphere; (3) plasma storage and release mechanisms in the magnetospheric tail; and (4) magnetic-field-aligned currents and magnetosphere-ionosphere interactions. A brief discussion of the prospects for the solution of these problems during and after the International Magnetospheric Study is given.

  7. 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. Copyright © 2015 Mosby, Inc. All rights reserved.

  8. 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].

  9. Effect of Physics Problem Solving on Structures Schemes and Knowledge Associations

    NASA Astrophysics Data System (ADS)

    Setyowidodo, I.; Jatmiko, B.; Susantini, E.; Widodo, S.; Shofwan, A.

    2017-09-01

    This study aims to develop learners’ thinking structures through associations, case based, and schematic method so that different knowledge structures have a role in influencing the structure of creative thinking. The learners have low mastery of physics materials since they are not given sufficient opportunity to build their own knowledge. They should be directed to approach each new problem or task with their prior knowledge, assimilate new information, and construct their own understanding. The design of this research was a quasi-experiment using purposive sampling. Data were analyzed using variance analysis. The design of this research was a quasi-experiment using purposive sampling. Data were analyzed using variance analysis. The learning process of problemsolving consists of: 1) identifying problems, 2) planning projects, 3) creating projects, 4) presenting projects, and 5) evaluating projects. From the results of this research, it can be concluded that problem-solving method can provide strong supports in developing the learners’ creative thinking skills as they can share their knowledge and interact with their friends and the environment. This learning activity also constitutes an appropriate technique to help the learners to develop problem solving knowledge and skills.

  10. The High Energy Solar Physics mission (HESP): Scientific objectives and technical description

    NASA Technical Reports Server (NTRS)

    Crannell, Carol; Dennis, Brian; Davis, John; Emslie, Gordon; Haerendel, Gerhard; Hudson, High; Hurford, Gordon; Lin, Robert; Ling, James; Pick, Monique

    1991-01-01

    The High Energy Solar Physics mission offers the opportunity for major breakthroughs in the understanding of the fundamental energy release and particle acceleration processes at the core of the solar flare problem. The following subject areas are covered: the scientific objectives of HESP; what we can expect from the HESP observations; the high energy imaging spectrometer (HEISPEC); the HESP spacecraft; and budget and schedule.

  11. Anderson Acceleration for Fixed-Point Iterations

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

    Walker, Homer F.

    The purpose of this grant was to support research on acceleration methods for fixed-point iterations, with applications to computational frameworks and simulation problems that are of interest to DOE.

  12. Particle Acceleration at the Sun and in the Heliosphere

    NASA Technical Reports Server (NTRS)

    Reames, Donald V.

    1999-01-01

    Energetic particles are accelerated in rich profusion at sites throughout the heliosphere. They come from solar flares in the low corona, from shock waves driven outward by coronal mass ejections (CMEs), from planetary magnetospheres and bow shocks. They come from corotating interaction regions (CIRs) produced by high-speed streams in the solar wind, and from the heliospheric termination shock at the outer edge of the heliospheric cavity. We sample all these populations near Earth, but can distinguish them readily by their element and isotope abundances, ionization states, energy spectra, angular distributions and time behavior. Remote spacecraft have probed the spatial distributions of the particles and examined new sources in situ. Most acceleration sources can be "seen" only by direct observation of the particles; few photons are produced at these sites. Wave-particle interactions are an essential feature in acceleration sources and, for shock acceleration, new evidence of energetic-proton-generated waves has come from abundance variations and from local cross-field scattering. Element abundances often tell us the physics the source plasma itself, prior to acceleration. By comparing different populations, we learn more about the sources, and about the physics of acceleration and transport, than we can possibly learn from one source alone.

  13. Problem based learning approaches to the technology education of physical therapy students.

    PubMed

    Castro-Sánchez, Adelaida M; Aguilar-Ferrándiz, María Encarnación M E; Matarán-Peñarrocha, Guillermo A Ga; Iglesias-Alonso, Alberto A; Fernández-Fernández, Maria Jesus M J; Moreno-Lorenzo, Carmen C

    2012-01-01

    Problem-Based Learning (PBL) is a whole-curriculum concept. This study aimed to compare learning preferences and strategies between physical therapy students taught by PBL and those receiving conventional lectures on massage therapy, trauma physical therapy, and electrotherapy, hydrotherapy, and thermotherapy. This quasi-experimental study included 182 male and female students on physical therapy diploma courses at three universities in Andalusia (Spain). The Canfield Learning Skills Inventory (CLSI) was used to assess learning strategies and the Approaches to Study Skills Inventory for Students (ASSIST) to analyze study preferences. At the end of the academic year 2009/10, physical therapy students taught by PBL considered the most important learning strategies to be group work, study organization, relationship of ideas, and academic results. In comparison to conventionally taught counterparts, they considered that PBL reduced lack of purpose, memorizing without relating, the law of minimum effort, and fear of failure. Among these PBL students, the most highly rated study preferences were: organization of course tasks, cordial interaction with the teacher, learning by reading and images, and direct hands-on experience. For these physical therapy students, PBL facilitates learning strategies and study preferences in comparison to conventional teaching.

  14. Measuring physical activity in children and adolescents for dietary surveys: practicalities, problems and pitfalls.

    PubMed

    Mindell, Jennifer S; Coombs, Ngaire; Stamatakis, Emmanuel

    2014-05-01

    Physical inactivity is an important risk factor for many chronic diseases and contributes to obesity and poor mental well-being. The present paper describes the main advantages and disadvantages, practical problems, suggested uses, and future developments regarding self-reported and objective data collection in the context of dietary surveys. In dietary surveys, physical activity is measured primarily to estimate energy expenditure. Energy expenditure surveillance is important for tracking changes over time, particularly given the debates over the role of the relative importance of energy intake and expenditure changes in the aetiology of obesity. It is also important to assess the extent of underreporting of dietary intake in these surveys. Physical activity data collected should include details on the frequency, duration and relative intensity of activity for each activity type that contributes considerably to overall activity and energy expenditure. Problems of validity and reliability, associated with inaccurate assessment, recall bias, and social desirability bias, are well-known; children under 10 years cannot report their activities accurately. However, despite such limitations, questionnaires are still the dominant method of physical activity assessment in dietary surveys due to their low cost and relatively low participant burden. Objective, time-stamped measures that monitor heart rate and/or movement can provide more comprehensive, quantitative assessment of physical activity but at greater cost and participant burden. Although overcoming many limitations of questionnaires, objective measures also have drawbacks, including technical, practical and interpretational issues.

  15. Applying physics to solve problems in new contexts and representations: Methods Students Use

    NASA Astrophysics Data System (ADS)

    Zollman, Dean

    2010-02-01

    ``The questions on the test were, like, totally different from the homework.'' All of us have heard variations on this statement. Yet, when we look at the homework and the test questions, we see great similarities. Changing the context or the representation in a physics problem can cause students to have significant difficulties. These difficulties persist sometimes in homework problems, exams and even hands-on activities. With significant effort from Sanjay Rebello our group has been investigating some of the issues which lead to the inability to apply physics learned in one context or with one representation to other situations. By looking at what aspects students are able to use easily and those that they have difficulty applying, we are beginning to understand some of the aspects that help this transfer of learning and some that do not. (Supported by the grants from the National Science Foundation and US Department of Education) )

  16. 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

  17. Accelerator Driven Nuclear Energy: The Thorium Option

    ScienceCinema

    Raja, Rajendran

    2018-01-05

    Conventional nuclear reactors use enriched Uranium as fuel and produce nuclear waste which needs to be stored away for over 10,000 years.   At the current rate of use, existing sources of Uranium will last for 50-100 years.  We describe a solution to the problem that uses particle accelerators to produce fast neutrons that can be used to burn existing nuclear waste and produce energy.  Such systems, initially proposed by Carlo Rubbia and collaborators in the 1990's, are being seriously considered by many countries as a possible solution to the green energy problem.  Accelerator driven reactors operate in a sub-critical regime and, thus, are safer and can obtain energy from plentiful elements such as Thorium-232 and Uranium-238. What is missing is the high intensity (10MW) accelerator that produces 1 GeV protons. We will describe scenarios which if implemented will make such systems a reality.  

  18. Examining End-Of-Chapter Problems Across Editions of an Introductory Calculus-Based Physics Textbook

    NASA Astrophysics Data System (ADS)

    Xiao, Bin

    End-Of-Chapter (EOC) problems have been part of many physics education studies. Typically, only problems "localized" as relevant to a single chapter were used. This work examines how well this type of problem represents all EOC problems and whether EOC problems found in leading textbooks have changed over the past several decades. To investigate whether EOC problems have connections between chapters, I solved all problems of the E&M; chapters of the most recent edition of a popular introductory level calculus-based textbook and coded the equations used to solve each problem. These results were compared to the first edition of the same text. Also, several relevant problem features were coded for those problems and results were compared for sample chapters across all editions. My findings include two parts. The result of equation usage shows that problems in the E&M; chapters do use equations from both other E&M; chapters and non-E&M; chapters. This out-of-chapter usage increased from the first edition to the last edition. Information about the knowledge structure of E&M; chapters was also revealed. The results of the problem feature study show that most EOC problems have common features but there was an increase of diversity in some of the problem features across editions.

  19. PREFACE: 17th International School on Condensed Matter Physics (ISCMP): Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications

    NASA Astrophysics Data System (ADS)

    Dimova-Malinovska, Doriana; Nesheva, Diana; Pecheva, Emilia; Petrov, Alexander G.; Primatarowa, Marina T.

    2012-12-01

    We are pleased to introduce the Proceedings of the 17th International School on Condensed Matter Physics: Open Problems in Condensed Matter Physics, Biomedical Physics and their Applications, organized by the Institute of Solid State Physics of the Bulgarian Academy of Sciences. The Chairman of the School was Professor Alexander G Petrov. Like prior events, the School took place in the beautiful Black Sea resort of Saints Constantine and Helena near Varna, going back to the refurbished facilities of the Panorama hotel. Participants from 17 different countries delivered 31 invited lecturers and 78 posters, contributing through three sessions of poster presentations. Papers submitted to the Proceedings were refereed according to the high standards of the Journal of Physics: Conference Series and the accepted papers illustrate the diversity and the high level of the contributions. Not least significant factor for the success of the 17 ISCMP was the social program, both the organized events (Welcome and Farewell Parties) and the variety of pleasant local restaurants and beaches. Visits to the Archaeological Museum (rich in valuable gold treasures of the ancient Thracian culture) and to the famous rock monastery Aladja were organized for the participants from the Varna Municipality. These Proceedings are published for the second time by the Journal of Physics: Conference Series. We are grateful to the Journal's staff for supporting this idea. The Committee decided that the next event will take place again in Saints Constantine and Helena, 1-5 September 2014. It will be entitled: Challenges of the Nanoscale Science: Theory, Materials and Applications. Doriana Dimova-Malinovska, Diana Nesheva, Emilia Pecheva, Alexander G Petrov and Marina T Primatarowa Editors

  20. Laser acceleration

    NASA Astrophysics Data System (ADS)

    Tajima, T.; Nakajima, K.; Mourou, G.

    2017-02-01

    The fundamental idea of Laser Wakefield Acceleration (LWFA) is reviewed. An ultrafast intense laser pulse drives coherent wakefield with a relativistic amplitude robustly supported by the plasma. While the large amplitude of wakefields involves collective resonant oscillations of the eigenmode of the entire plasma electrons, the wake phase velocity ˜ c and ultrafastness of the laser pulse introduce the wake stability and rigidity. A large number of worldwide experiments show a rapid progress of this concept realization toward both the high-energy accelerator prospect and broad applications. The strong interest in this has been spurring and stimulating novel laser technologies, including the Chirped Pulse Amplification, the Thin Film Compression, the Coherent Amplification Network, and the Relativistic Mirror Compression. These in turn have created a conglomerate of novel science and technology with LWFA to form a new genre of high field science with many parameters of merit in this field increasing exponentially lately. This science has triggered a number of worldwide research centers and initiatives. Associated physics of ion acceleration, X-ray generation, and astrophysical processes of ultrahigh energy cosmic rays are reviewed. Applications such as X-ray free electron laser, cancer therapy, and radioisotope production etc. are considered. A new avenue of LWFA using nanomaterials is also emerging.

  1. Self-shielded electron linear accelerators designed for radiation technologies

    NASA Astrophysics Data System (ADS)

    Belugin, V. M.; Rozanov, N. E.; Pirozhenko, V. M.

    2009-09-01

    This paper describes self-shielded high-intensity electron linear accelerators designed for radiation technologies. The specific property of the accelerators is that they do not apply an external magnetic field; acceleration and focusing of electron beams are performed by radio-frequency fields in the accelerating structures. The main characteristics of the accelerators are high current and beam power, but also reliable operation and a long service life. To obtain these characteristics, a number of problems have been solved, including a particular optimization of the accelerator components and the application of a variety of specific means. The paper describes features of the electron beam dynamics, accelerating structure, and radio-frequency power supply. Several compact self-shielded accelerators for radiation sterilization and x-ray cargo inspection have been created. The introduced methods made it possible to obtain a high intensity of the electron beam and good performance of the accelerators.

  2. Severe physical punishment: risk of mental health problems for poor urban children in Brazil

    PubMed Central

    Duarte, Cristiane S; Peres, Clovis A; Nascimento, Rosimeire; Curto, Bartira M; Paula, Cristiane S

    2009-01-01

    Abstract Objective To examine the relationship between specific types of child mental health problems and severe physical punishment, in combination with other important known risk factors. Methods We conducted a cross-sectional study in Embu, São Paulo, Brazil, as the Brazilian component of a multicountry survey on abuse in the family environment. From a probabilistic sample of clusters that included all eligible households (women aged 15–49 years with a son or daughter < 18 years of age), we randomly selected one mother–child pair per household (n = 813; attrition rate: 17.6%). This study focused on children aged 6–17 years (n = 480). Child Behaviour Checklist CBCL/6–18 was used to identify children with internalizing problems only, externalizing problems only, and both internalizing and externalizing problems (comorbidity). Severe physical punishment was defined as being hit with an object, being kicked, choked, smothered, burnt, scalded, branded, beaten or threatened with a weapon. We examined other potential correlates from four domains: child (gender, age, ever witnessing marital violence); mother (education, unemployment, anxiety or depression, marital violence); father (absence, drunkenness); and family (socioeconomic status). The WHO Self-Reporting Questionnaire (SRQ-20) was used to identify maternal anxiety or depression (score > 7). Backward logistic regression analysis identified independent correlates and significant interactions. Findings Multivariate modelling showed that severe punishment was an independent correlate of comorbid internalizing and externalizing problems but was not associated with internalizing problems only. It increased the risk of externalizing problems alone only for children and adolescents not exposed to maternal anxiety or depression. Maternal anxiety or depression increased the risk only for children or adolescents not exposed to severe punishment. Conclusion Severe punishment may be related to child mental

  3. 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

    2014-08-06

    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.

  4. Reinventing the Accelerator for the High Energy Frontier

    ScienceCinema

    Rosenzweig, James [UCLA, Los Angeles, California, United States

    2017-12-09

    The history of discovery in high-energy physics has been intimately connected with progress in methods of accelerating particles for the past 75 years. This remains true today, as the post-LHC era in particle physics will require significant innovation and investment in a superconducting linear collider. The choice of the linear collider as the next-generation discovery machine, and the selection of superconducting technology has rather suddenly thrown promising competing techniques -- such as very large hadron colliders, muon colliders, and high-field, high frequency linear colliders -- into the background. We discuss the state of such conventional options, and the likelihood of their eventual success. We then follow with a much longer view: a survey of a new, burgeoning frontier in high energy accelerators, where intense lasers, charged particle beams, and plasmas are all combined in a cross-disciplinary effort to reinvent the accelerator from its fundamental principles on up.

  5. 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.

  6. Accelerator shield design of KIPT neutron source facility

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

    Zhong, Z.; Gohar, Y.

    Argonne National Laboratory (ANL) of the United States and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the design development of a neutron source facility at KIPT utilizing an electron-accelerator-driven subcritical assembly. Electron beam power is 100 kW, using 100 MeV electrons. The facility is designed to perform basic and applied nuclear research, produce medical isotopes, and train young nuclear specialists. The biological shield of the accelerator building is designed to reduce the biological dose to less than 0.5-mrem/hr during operation. The main source of the biological dose is the photons and the neutrons generatedmore » by interactions of leaked electrons from the electron gun and accelerator sections with the surrounding concrete and accelerator materials. The Monte Carlo code MCNPX serves as the calculation tool for the shield design, due to its capability to transport electrons, photons, and neutrons coupled problems. The direct photon dose can be tallied by MCNPX calculation, starting with the leaked electrons. However, it is difficult to accurately tally the neutron dose directly from the leaked electrons. The neutron yield per electron from the interactions with the surrounding components is less than 0.01 neutron per electron. This causes difficulties for Monte Carlo analyses and consumes tremendous computation time for tallying with acceptable statistics the neutron dose outside the shield boundary. To avoid these difficulties, the SOURCE and TALLYX user subroutines of MCNPX were developed for the study. The generated neutrons are banked, together with all related parameters, for a subsequent MCNPX calculation to obtain the neutron and secondary photon doses. The weight windows variance reduction technique is utilized for both neutron and photon dose calculations. Two shielding materials, i.e., heavy concrete and ordinary concrete, were considered for the shield design. The main goal is to maintain

  7. REVIEWS OF TOPICAL PROBLEMS: Analytic calculations on digital computers for applications in physics and mathematics

    NASA Astrophysics Data System (ADS)

    Gerdt, V. P.; Tarasov, O. V.; Shirkov, Dmitrii V.

    1980-01-01

    The present state of analytic calculations on computers is reviewed. Several programming systems which are used for analytic calculations are discussed: SCHOONSCHIP, CLAM, REDUCE-2, SYMBAL, CAMAL, AVTO-ANALITIK, MACSYMA, etc. It is shown that these systems can be used to solve a wide range of problems in physics and mathematics. Some physical applications are discussed in celestial mechanics, the general theory of relativity, quantum field theory, plasma physics, hydrodynamics, atomic and molecular physics, and quantum chemistry. Some mathematical applications which are discussed are evaluating indefinite integrals, solving differential equations, and analyzing mathematical expressions. This review is addressed to physicists and mathematicians working in a wide range of fields.

  8. Testing posttraumatic stress as a mediator of physical, sexual, and psychological intimate partner violence and substance problems among women.

    PubMed

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

    2009-12-01

    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.

  9. Physics at the SPS.

    PubMed

    Gatignon, L

    2018-05-01

    The CERN Super Proton Synchrotron (SPS) has delivered a variety of beams to a vigorous fixed target physics program since 1978. In this paper, we restrict ourselves to the description of a few illustrative examples in the ongoing physics program at the SPS. We will outline the physics aims of the COmmon Muon Proton Apparatus for Structure and Spectroscopy (COMPASS), north area 64 (NA64), north area 62 (NA62), north area 61 (NA61), and advanced proton driven plasma wakefield acceleration experiment (AWAKE). COMPASS studies the structure of the proton and more specifically of its spin. NA64 searches for the dark photon A', which is the messenger for interactions between normal and dark matter. The NA62 experiment aims at a 10% precision measurement of the very rare decay K + → π + νν. As this decay mode can be calculated very precisely in the Standard Model, it offers a very good opportunity to look for new physics beyond the Standard Model. The NA61/SHINE experiment studies the phase transition to Quark Gluon Plasma, a state in which the quarks and gluons that form the proton and the neutron are de-confined. Finally, AWAKE investigates proton-driven wake field acceleration: a promising technique to accelerate electrons with very high accelerating gradients. The Physics Beyond Colliders study at CERN is paving the way for a significant and diversified continuation of this already rich and compelling physics program that is complementary to the one at the big colliders like the Large Hadron Collider.

  10. Physics at the SPS

    NASA Astrophysics Data System (ADS)

    Gatignon, L.

    2018-05-01

    The CERN Super Proton Synchrotron (SPS) has delivered a variety of beams to a vigorous fixed target physics program since 1978. In this paper, we restrict ourselves to the description of a few illustrative examples in the ongoing physics program at the SPS. We will outline the physics aims of the COmmon Muon Proton Apparatus for Structure and Spectroscopy (COMPASS), north area 64 (NA64), north area 62 (NA62), north area 61 (NA61), and advanced proton driven plasma wakefield acceleration experiment (AWAKE). COMPASS studies the structure of the proton and more specifically of its spin. NA64 searches for the dark photon A', which is the messenger for interactions between normal and dark matter. The NA62 experiment aims at a 10% precision measurement of the very rare decay K+ → π+νν. As this decay mode can be calculated very precisely in the Standard Model, it offers a very good opportunity to look for new physics beyond the Standard Model. The NA61/SHINE experiment studies the phase transition to Quark Gluon Plasma, a state in which the quarks and gluons that form the proton and the neutron are de-confined. Finally, AWAKE investigates proton-driven wake field acceleration: a promising technique to accelerate electrons with very high accelerating gradients. The Physics Beyond Colliders study at CERN is paving the way for a significant and diversified continuation of this already rich and compelling physics program that is complementary to the one at the big colliders like the Large Hadron Collider.

  11. Concordance among Physical Educators', Teachers', and Parents' Perceptions of Attention Problems in Children

    ERIC Educational Resources Information Center

    Efstratopoulou, Maria; Simons, Johan; Janssen, Rianne

    2013-01-01

    Objective: The study examined the concordance among rating sources on attention problems of elementary school-aged children. Method: A randomly selected sample ("N" = 841) of children was rated by the physical educators, the teachers, and the parents, using the Attention Scales of the Motor Behavior Checklist (MBC), the Teacher Report…

  12. Educating and Training Accelerator Scientists and Technologists for Tomorrow

    NASA Astrophysics Data System (ADS)

    Barletta, William; Chattopadhyay, Swapan; Seryi, Andrei

    2012-01-01

    Accelerator science and technology is inherently an integrative discipline that combines aspects of physics, computational science, electrical and mechanical engineering. As few universities offer full academic programs, the education of accelerator physicists and engineers for the future has primarily relied on a combination of on-the-job training supplemented with intensive courses at regional accelerator schools. This article describes the approaches being used to satisfy the educational curiosity of a growing number of interested physicists and engineers.

  13. Educating and Training Accelerator Scientists and Technologists for Tomorrow

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

    Barletta, William A.; Chattopadhyay, Swapan; Seryi, Andrei

    2012-07-01

    Accelerator science and technology is inherently an integrative discipline that combines aspects of physics, computational science, electrical and mechanical engineering. As few universities offer full academic programs, the education of accelerator physicists and engineers for the future has primarily relied on a combination of on-the-job training supplemented with intense courses at regional accelerator schools. This paper describes the approaches being used to satisfy the educational interests of a growing number of interested physicists and engineers.

  14. Challenges in 21st Century Physics

    NASA Technical Reports Server (NTRS)

    Wilson, Thomas L.

    2007-01-01

    We are truly fortunate to live in one of the great epochs of human discovery, a time when science is providing new visions and understanding about ourselves and the world in which we live. At last, we are beginning to explore the Universe itself. One particularly exciting area of advancement is high-energy physics where several existing concepts will be put to the test. A brief survey will be given of accomplishments in 20th Century physics. These include relativity and quantum physics which have produced breakthroughs in cosmology, astrophysics, and high-energy particle physics. The current situation is then assessed, combining the last 100 years of progress with new 21st Century challenges about unification and where to go next. Finally, the future is upon us. The next frontier in experimental high-energy physics, the Large Hadron Collider (LHC) at CERN in Geneva, is scheduled to begin coming online this year (2007). The potential for the LHC to address several of the significant problems in physics today will be discussed, as this great accelerator examines the predictions of the Standard Model of particle physics and even cosmology. New physics and new science will surely emerge and a better vision of the world will unfold.

  15. Acceleration of High Energy Cosmic Rays in the Nonlinear Shock Precursor

    NASA Astrophysics Data System (ADS)

    Derzhinsky, F.; Diamond, P. H.; Malkov, M. A.

    2006-10-01

    The problem of understanding acceleration of very energetic cosmic rays to energies above the 'knee' in the spectrum at 10^15-10^16eV remains one of the great challenges in modern physics. Recently, we have proposed a new approach to understanding high energy acceleration, based on exploiting scattering of cosmic rays by inhomogenities in the compressive nonlinear shock precursor, rather than by scattering across the main shock, as is conventionally assumed. We extend that theory by proposing a mechanism for the generation of mesoscale magnetic fields (krg<1, where rg is the cosmic ray gyroradius). The mechanism is the decay or modulational instability of resonantly generated Alfven waves scattering off ambient density perturbations in the precursors. Such perturbations can be produced by Drury instability. This mechanism leads to the generation of longer wavelength Alfven waves, thus enabling the confinement of higher energy particles. A simplified version of the theory, cast in the form of a Fokker-Planck equation for the Alfven population, will also be presented. This process also limits field generation on rg scales.

  16. Exploring phase space using smartphone acceleration and rotation sensors simultaneously

    NASA Astrophysics Data System (ADS)

    Monteiro, Martín; Cabeza, Cecilia; Martí, Arturo C.

    2014-07-01

    A paradigmatic physical system as the physical pendulum is experimentally studied using the acceleration and rotation (gyroscope) sensors available on smartphones and other devices such as iPads and tablets. A smartphone is fixed to the outside of a bicycle wheel whose axis is kept horizontal and fixed. The compound system, wheel plus smartphone, defines a physical pendulum which can rotate, giving full turns in one direction, or oscillate about the equilibrium position (performing either small or large oscillations). Measurements of the radial and tangential acceleration and the angular velocity obtained with smartphone sensors allow a deep insight into the dynamics of the system to be gained. In addition, thanks to the simultaneous use of the acceleration and rotation sensors, trajectories in the phase space are directly obtained. The coherence of the measures obtained with the different sensors and by traditional methods is remarkable. Indeed, due to their low cost and increasing availability, smartphone sensors are valuable tools that can be used in most undergraduate laboratories.

  17. Accelerator science and technology in Europe 2008-2017

    NASA Astrophysics Data System (ADS)

    Romaniuk, Ryszard S.

    2013-10-01

    European Framework Research Projects have recently added a lot of meaning to the building process of the ERA - the European Research Area. Inside this, the accelerator technology plays an essential role. Accelerator technology includes large infrastructure and intelligent, modern instrumentation embracing mechatronics, electronics, photonics and ICT. During the realization of the European research and infrastructure project FP6 CARE 2004-2008 (Coordinated Accelerator Research in Europe), concerning the development of large accelerator infrastructure in Europe, it was decided that a scientific editorial series of peer-reviewed monographs from this research area will be published in close relation with the projects. It was a completely new and quite brave idea to combine a kind of a strictly research publisher with a transient project, lasting only four or five years. Till then nobody did something like that. The idea turned out to be a real success. The publications now known and valued in the accelerator world, as the (CERN-WUT) Editorial Series on Accelerator Science and Technology, is successfully continued in already the third European project EuCARD2 and has logistic guarantees, for the moment, till the 2017, when it will mature to its first decade. During the realization of the European projects EuCARD (European Coordination for Accelerator R&D 2009-2013 and TIARA (Test Infrastructure of Accelerator Research Area in Europe) there were published 18 volumes in this series. The ambitious plans for the nearest years is to publish, hopefully, a few tens of new volumes. Accelerator science and technology is one of a key enablers of the developments in the particle physic, photon physics and also applications in medicine and industry. The paper presents a digest of the research results in the domain of accelerator science and technology in Europe, published in the monographs of the European Framework Projects (FP) on accelerator technology. The succession of CARE, Eu

  18. Illness consequences after myocardial infarction: problems with physical functioning and return to work.

    PubMed

    Brink, Eva; Brändström, Yvonne; Cliffordsson, Christina; Herlitz, Johan; Karlson, Björn W

    2008-12-01

    This paper is a report of a study to explore health problems, physical and mental functioning, and physical activity in working-age patients after myocardial infarction, in order to assess the possible effects of these factors on return to work. A diagnosis of myocardial infarction may discourage patients from continuing an active working life. Enabling myocardial infarction patients to return to work has benefits for both individuals and society. A convenience sample was recruited of 88 patients, physical activity (footsteps per day) were conducted in 2005-2006, 4-6 months after myocardial infarction. To explore data and compare groups, t-tests were applied. Logistic regression analyses were performed to identify variables that best predicted return to work. Differences were identified between individuals who were employed after myocardial infarction and those who were not. Those not in work scored lower on variables related to the physical dimension of health-related quality of life and on physical activity. Logistic regression revealed that a multivariate model including age, physical dimension of health-related quality of life and footsteps per day predicted return to work in 68% of all cases (R2=0.344). Low physical health and low physical activity after myocardial infarction negatively affect returning to work. These findings stress the importance of clinical assessment of myocardial infarction patients' daily physical activity and physical functioning.

  19. On some variational acceleration techniques and related methods for local refinement

    NASA Astrophysics Data System (ADS)

    Teigland, Rune

    1998-10-01

    This paper shows that the well-known variational acceleration method described by Wachspress (E. Wachspress, Iterative Solution of Elliptic Systems and Applications to the Neutron Diffusion Equations of Reactor Physics, Prentice-Hall, Englewood Cliffs, NJ, 1966) and later generalized to multilevels (known as the additive correction multigrid method (B.R Huthchinson and G.D. Raithby, Numer. Heat Transf., 9, 511-537 (1986))) is similar to the FAC method of McCormick and Thomas (S.F McCormick and J.W. Thomas, Math. Comput., 46, 439-456 (1986)) and related multilevel methods. The performance of the method is demonstrated for some simple model problems using local refinement and suggestions for improving the performance of the method are given.

  20. Accelerator Science: Collider vs. Fixed Target

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

    Lincoln, Don

    Particle physics experiments employ high energy particle accelerators to make their measurements. However there are many kinds of particle accelerators with many interesting techniques. One important dichotomy is whether one takes a particle beam and have it hit a stationary target of atoms, or whether one takes two counter rotating beams of particles and smashes them together head on. In this video, Fermilab’s Dr. Don Lincoln explains the pros and cons of these two powerful methods of exploring the rules of the universe.