8,907 research outputs found
Educating Seth: An Ecosophical Conversation
Most accounts of human activity have a particular structure that supports the accounting. Education as a human activity has over centuries, and particularly in the past century, developed a narrative structure that, while seemingly "neutral", privileges accounts of a certain kind. The authors suggest that if ecosophical education is to find a presence in today's schools, the now dominant narrative structure needs to be challenged. By revealing an alternate narrative structure embodied in the particularities of a grade 4 classroom, the authors hope that such a narrative structure can provide ecosophical education with an authentic home in today's schools
Tracking Transfer of Reform Methodology from Science and Math College Courses to the Teaching Style of Beginning Teachers of Grades 5-12
The purpose of this study was to determine if reformed science and math courses at community colleges and the university were impacting education majors as they began a teaching career. The reformed courses, in contrast to typical lecture classes, implemented inquiry-based methods that emphasized deep understanding of fundamental science and math concepts. Trained evaluators, utilizing the Reformed Teaching Observation Protocol (RTOP) gathered a total of 86 classroom observations to gauge the level of reform that beginning teachers (one to three years’ teaching experience) were implementing in grades 5-12. The pre-service experience of the beginning teachers varied from having had zero to four reform courses. Results indicated that teachers who had completed reform college courses instructed in a significantly more reformed manner. Furthermore, analysis of years of teaching experience revealed that, while both control and experimental groups achieved higher RTOP scores as they progressed from year to year, the experimental group significantly outpaced their counterparts
The Impact of a Summer Workshop: Staff Orientation at Mesa Community College
The Arizona Collaborative for Excellence in the Preparation of Teachers (ACEPT) is a National Science Foundation (NSF) funded project to reform teacher preparation in Arizona. One of the major modes for initiating both collaboration and reform between and among university and community college staff has been the Summer Faculty Enhancement Workshops developed and offered by ACEPT co-principal investigators each summer since 1996. The summer of 1999 featured five workshops, one of which was the Geology Summer Workshop which brought participants into close contact with eighteen reformed practices appropriate for large lecture style classes. One of the nineteen participants was Ray Grant, Department of Science Chair at Mesa Community College, one of the collaborating institutions in ACEPT. This report describes what Ray, as department chair, did as a follow-up to the summer workshop. What occurred completely transformed the Department of Science staff orientation meeting held just prior to the fall semester. Some of the surprising events are described in this report. The transformation of the staff meeting not only speaks to the impact of the Geology Summer Workshop, but also suggests creative roles for staff orientation meetings in community college settings
3D Finite Volume Simulation of Accretion Discs with Spiral Shocks
We perform 2D and 3D numerical simulations of an accretion disc in a close
binary system using the Simplified Flux vector Splitting (SFS) finite volume
method. In our calculations, gas is assumed to be the ideal one, and we
calculate the cases with gamma=1.01, 1.05, 1.1 and 1.2. The mass ratio of the
mass losing star to the mass accreting star is unity. Our results show that
spiral shocks are formed on the accretion disc in all cases. In 2D calculations
we find that the smaller gamma is, the more tightly the spiral winds. We
observe this trend in 3D calculations as well in somewhat weaker sense.Comment: 2 pages, LaTeX with 2 ps figures using crckapb.sty. To appear in the
Proceedings of Numerical Astrophysics 1998, Tokyo, Japan, 10-13 March, 1998,
eds. S. M. Miyama, K. Tomisaka and T. Hanawa (Kluwer Academic Publishers
Spiral Structure in IP Peg: Confronting Theory and Observations
The first convincing piece of evidence of spiral structure in the accretion
disc in IP Pegasi was found by Steeghs et al. (1997). We performed two kinds of
2D hydrodynamic simulations, a SFS finite volume scheme and a SPH scheme, with
a mass ratio of 0.5. Both results agreed well with each other. We constructed
Doppler maps and line flux-binary phase relations based on density
distributions, the results agreeing well with those obtained by observation.Comment: 4 pages, LaTeX with 2 ps figures using crckapb.sty. To appear in the
Proceedings of Numerical Astrophysics 1998, Tokyo, Japan, 10-13 March, 1998,
eds. S. M. Miyama, K. Tomisaka and T. Hanawa (Kluwer Academic Publishers
Coordinate space proton-deuteron scattering calculations including Coulomb force effects
We present a practical method to solve the proton-deuteron scattering problem
at energies above the three-body breakup threshold, in which we treat
three-body integral equations in coordinate space accommodating long-range
proton-proton Coulomb interactions. The method is examined for phase shift
parameters, and then applied to calculations of differential cross sections in
elastic and breakup reactions, analyzing powers, etc. with a realistic
nucleon-nucleon force and three-nucleon forces. Effects of the Coulomb force
and the three-nucleon forces on these observables are discussed in comparing
with experimental data.Comment: 15 pages, 14 figures, submitted to PR
Gigantic Enhancement of Magneto-Chiral Effect in Photonic Crystals
We theoretically propose a method to enhance dramatically a
magneto-chiral(MC) effect by using the photonic crystals composed of a
multiferroic material. The MC effect, the directional birefringence even for
unpolarized light, is so small that it has been difficult to observe
experimentally. Two kinds of periodic structures are investigated; (a) a
multilayer and (b) a stripe composed of a magneto-chiral material and air. In
both cases, the difference in reflectivity between different magnetization
directions is enhanced by a factor of hundreds compared with a bulk material.Comment: 3 pages, 3 figure
Microscopic Theory of Skyrmions in Quantum Hall Ferromagnets
We present a microscopic theory of skyrmions in the monolayer quantum Hall
ferromagnet. It is a peculiar feature of the system that the number density and
the spin density are entangled intrinsically as dictated by the W
algebra. The skyrmion and antiskyrmion states are constructed as W-rotated states of the hole-excited and electron-excited states,
respectively. They are spin textures accompanied with density modulation that
decreases the Coulomb energy. We calculate their excitation energy as a
function of the Zeeman gap and compared the result with experimental data.Comment: 15 pages (to be published in PRB
Hydrodynamic Simulations of Counterrotating Accretion Disks
Hydrodynamic simulations have been used to study accretion disks consisting
of counterrotating components with an intervening shear layer(s).
Configurations of this type can arise from the accretion of newly supplied
counterrotating matter onto an existing corotating disk. The grid-dependent
numerical viscosity of our hydro code is used to simulate the influence of a
turbulent viscosity of the disk. Firstly, we consider the case where the gas
well above the disk midplane rotates with angular rate +\Omega(r) and that well
below has the same properties but rotates with rate -\Omega(r). We find that
there is angular momentum annihilation in a narrow equatorial boundary layer in
which matter accretes supersonically with a velocity which approaches the
free-fall velocity and the average accretion speed of the disk can be
enormously larger than that for a conventional \alpha-disk rotating in one
direction. Secondly, we consider the case of a corotating accretion disk for
rr_t. In this case we observed, that
matter from the annihilation layer lost its stability and propagated inward
pushing matter of inner regions of the disk to accrete. Thirdly, we
investigated the case where counterrotating matter inflowing from large radial
distances encounters an existing corotating disk. Friction between the
inflowing matter and the existing disk is found to lead to fast boundary layer
accretion along the disk surfaces and to enhanced accretion in the main disk.
These models are pertinent to the formation of counterrotating disks in
galaxies and possibly in Active Galactic Nuclei and in X-ray pulsars in binary
systems.Comment: LaTeX, 18 pages, to appear in Ap
Coexistence of Bloch electrons and glassy electrons in Ca10(Ir4As8)(Fe2_xIrxAs2)5 revealed by angle-resolved photoemission spectroscopy
Angle-resolved photoemission spectroscopy of Ca10(Ir4As8)(Fe2_xIrxAs2)5 shows
that the Fe 3d electrons in the FeAs layer form the hole-like Fermi pocket at
the zone center and the electron-like Fermi pockets at the zone corners as
commonly seen in various Fe-based superconductors. The FeAs layer is heavily
electron doped and has relatively good two dimensionality. On the other hand,
the Ir 5d electrons are metallic and glassy probably due to atomic disorder
related to the Ir 5d orbital instability. Ca10(Ir4As8)(Fe2_xIrxAs2)5 exhibits a
unique electronic state where the Bloch electrons in the FeAs layer coexist
with the glassy electrons in the Ir4As8 layer.Comment: 4 pages, 3 figure
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