Fast High Resolution Echelle Spectroscopy Of A Laboratory Plasma

An echelle diffraction grating and a multianode photomultiplier tube are paired to construct a high resolution (R=lambda/delta lambda approximate to 2.5x10(4)) spectrograph with fast time response for use from the UV through the visible. This instrument has analyzed the line shape of C III impurity ion emission at 229.687 nm over the lifetime (approximate to 100 mu s) of the hydrogen plasmas produced at SSX. The ion temperature and line of sight average velocity are inferred from the observed thermal broadening and Doppler shift of the line. The time resolution of these measurements is about 1 mu s, sufficient to observe the fastest magnetohydrodynamic activity

Experimental Observation Of Energetic Ions Accelerated By Three-Dimensional Magnetic Reconnection In A Laboratory Plasma

Magnetic reconnection is widely believed responsible for heating the solar corona as well as for generating X-rays and energetic particles in solar flares. On astrophysical scales, reconnection in the intergalactic plasma is a prime candidate for a local source (Mpc) of cosmic rays exceeding the Greisen-Zatsepin-Kuzmin cutoff (∼10(19) eV). In a laboratory astrophysics experiment, we have made the first observation of particles accelerated by magnetic reconnection events to energies significantly above both the thermal and the characteristic magnetohydrodynamic energies. These particles are correlated temporally and spatially with the formation of three-dimensional magnetic structures in the reconnection region

Six Volleyball Skill Tests as a Predictor of Game Performance

The purpose of this study was to investigate the relationship of six selected volleyball skill tests to actual volleyball game performance. The six skill test items were administered to 64 subjects, who were all members of a college level introductory volleyball course. Based on the ratings of a panel of experts, subjects were rated during game play as good, average, or poor performers. The stepwise discriminant analysis was used to analyze the relationship between skill tests and game performance. Four of the six skill tests were identified as significantly contributing to group membership. These tests, in order of the magnitude of their standardized discriminant function coefficients were: 1. Brumbach Serve Test, 2. AAHPER Wall Volley test, 3. AAHPERD Wall Spike Test, and 4. AAHPERD Serve Test. It was concluded that a volleyball skill test battery consisting of these four items would objectively measure volleyball playing ability and discriminate between players of various skill levels. The results of this test battery could be used for classification, diagnosis, motivational purposes, and grading

Issues in Forest Restoration: Full Cost Accounting of the 2010 Schultz Fire

The Schultz Fire of 2010 burned just over 15,000 forested acres and caused the evacuation of hundreds of homes. Heavy floods followed the fire, resulting in extensive damage to property downstream from the charred hillsides. Nearly three years later, seasonal flooding is still a concern and residents continue to live under the threat of swift floodwaters that may carve unanticipated pathways through their sloping neighborhoods. Official reports form city, county, state, and federal governments have listed response and mitigation costs of the fire and flood at nearly $60 million. This study adds to those costs, exploring the impacts on private property owners, as well as societal costs that are often overlooked when quantifying the full impact of disasters. Through analysis of Coconino County Assessor’s records, a survey of residents in the fire/flood impact area, and the perceived value of both endangered species habitat and human life, this study conservatively estimates the total impact of the Schultz Fire at between$133 million and $147 million

The Emotional Dimensions of Urban Teacher Change

This study used an emotional geographies theoretical framework to analyze the emotional dimensions of urban teacher change. Fifteen urban physical education teachers involved in a comprehensive curriculum reform project were interviewed and observed multiple times across one school year. Data were analyzed using inductive analysis, and trustworthiness measures included triangulation, peer debriefing, researcher journals, and member checks. Teachers reported that emotional dimensions related to their urban students, colleagues, and status heavily influenced their engagement in the project. The discussion section maps the emotional dimensions of these teachers\u27 change experiences onto an emotional geographies framework that situates their experiences in change literature and offers a roadmap for future reform initiatives

Three-Dimensional Magnetohydrodynamics Simulations Of Counter-Helicity Spheromak Merging In The Swarthmore Spheromak Experiment

Recent counter-helicity spheromak merging experiments in the Swarthmore Spheromak Experiment (SSX) have produced a novel compact torus (CT) with unusual features. These include a persistent antisymmetric toroidal magnetic field profile and a slow, nonlinear emergence of the n = 1 tilt mode. Experimental measurements are inconclusive as to whether this unique CT is a fully merged field-reversed configuration (FRC) with strong toroidal field or a partially merged doublet CT configuration with both spheromak- and FRC-like characteristics. In this paper, the SSX merging process is studied in detail using three-dimensional resistive MHD simulations from the Hybrid Magnetohydrodynamics (HYM) code. These simulations show that merging plasmas in the SSX parameter regime only partially reconnect, leaving behind a doublet CT rather than an FRC. Through direct comparisons, we show that the magnetic structure in the simulations is highly consistent with the SSX experimental observations. We also find that the n = 1 tilt mode begins as a fast growing linear mode that evolves into a slower-growing nonlinear mode before being detected experimentally. A simulation parameter scan over resistivity, viscosity, and line-tying shows that these parameters can strongly affect the behavior of both the merging process and the tilt mode. In fact, merging in certain parameter regimes is found to produce a toroidal-field-free FRC rather than a doublet CT. (C) 2011 American Institute of Physics. [doi:10.1063/1.3660533

Teachers Mentoring Teachers: A View Over Time

from the introduction: It was the purpose of this investigation to explore one school districtʼs professional development program intended to address the challenges that newer teachers face when learning new curricula

The Effectiveness of Mentoring-Based Professional Development on Physical Education Teachers\u27 Pedometer and Computer Efficacy and Anxiety

The purpose of our study was to examine the impact of mentoring-based professional development on physical education teachers\u27 efficacy. Experienced mentor teachers were paired (n = 15) with inexperienced protégé teachers (n = 15) at the beginning of a yearlong intervention study. It was hypothesized that teachers would increase their efficacy to use pedometers and computers to enhance instruction, and reduce their computer anxiety. Repeated-measures ANOVAs for mentors and protégés revealed a variety of significant main effects. We found increases in computer and pedometer efficacy. A second set of repeated-measures ANOVAs based on mentors\u27, protégés\u27, and control groups\u27 scores revealed a significant interaction for computer efficacy, indicating that both mentors and protégés significantly increased their computer efficacy compared with the control group. Finally, a significant interaction effect was also found for pedometer efficacy, again indicating that both groups significantly increased their efficacy compared with control teachers

Energetic Particles From Three-Dimensional Magnetic Reconnection Events In The Swarthmore Spheromak Experiment

Measurements are presented from the Swarthmore Spheromak Experiment (SSX) [M. R. Brown, Phys. Plasmas 6, 1717 (1999)] showing a population of superthermal, super-Alfvénic ions with Ē≅90 eV and Emax⩾200 eV accelerated by reconnection activity in three-dimensional magnetic structures. These energetic ions are temporally and spatially correlated with three-dimensional magnetic reconnection events (measured with a 3D probe array) and are accelerated along the X-line normal to the local 2D plane of reconnection. In a typical SSX discharge, the peak reconnection electromotive force ℰ=vBL⩽(105 m/s)(0.05 T)(0.1 m)=500 V consistent with our observations. In addition, test particle simulations using magnetohydrodynamic (MHD) data from SSX simulations and run with dimensionless parameters similar to the experiment (S=1000, β=0.1) show acceleration of ions up to 2vAlf in a few Alfvén times consistent with the measurement. The process includes two phases—a strong but short duration direct acceleration in the quasi-steady reconnection electric field, and a weaker longer lived sub-diffusive component associated with turbulence

The Influence of Professional Development on Teachers\u27 Psychosocial Perceptions of Teaching a Health-Related Physical Education Curriculum

The impact of a yearlong professional development intervention on physical education teachers\u27 psychosocial perceptions was investigated. Experienced mentor teachers (n = 15) were paired with inexperienced protégé teachers (n = 15) who helped them learn how to teach a health-related physical education curriculum (i.e., the Exemplary Physical Education Curriculum). Using the theory of planned behavior as the guiding theory, it was hypothesized that teachers would experience favorable increases in various psychological constructs (e.g., attitude) and variables reflecting the social culture of their schools (e.g., administrator\u27s perceptions) as compared with control teachers (n = 17). A variety of statistically significant main and interaction effects with mean scores in expected directions were found. In general, mentors and protégés developed a more positive view of their own psychological state (e.g., perceived behavioral control) and of the immediate school social environment (i.e., support from administrators and fellow teachers). The significant results, combined with meaningful effect sizes, supported the effectiveness of this intervention