5,916 research outputs found
Asynchronous Course Delivery: Instructor and Student Views
Accompanying the projected growth in computers, bandwidth improvements will make Internet use a more satisfying experience, leading to increased usage. It follows that faculty in higher education will explore strategies that increase student achievement and satisfaction in asynchronous teaching and learning. Use of the Internet for course and program delivery will increase. The potential of the Web as both a set of tools and a medium for course delivery offers limitless possibilities for creating innovative course design that can be more effective than some classroom experiences (Hafner & Oblinger, 1998). There is evidence that building an online community begins with establishing good online program administration. Central to this is the infrastructure to support online delivery coupled with the faculty who create, deliver, and manage the courses. The debate continues among educators as to the effectiveness of asynchronous teaching and learning in higher education. Some argue it provides a new context for teaching and learning, chiefly because it removes the constraints of time and physical presence
Quantum Dot Potentials: Symanzik Scaling, Resurgent Expansions and Quantum Dynamics
This article is concerned with a special class of the ``double-well-like''
potentials that occur naturally in the analysis of finite quantum systems.
Special attention is paid, in particular, to the so-called Fokker-Planck
potential, which has a particular property: the perturbation series for the
ground-state energy vanishes to all orders in the coupling parameter, but the
actual ground-state energy is positive and dominated by instanton
configurations of the form exp(-a/g), where a is the instanton action. The
instanton effects are most naturally taken into account within the modified
Bohr-Sommerfeld quantization conditions whose expansion leads to the
generalized perturbative expansions (so-called resurgent expansions) for the
energy values of the Fokker-Planck potential. Until now, these resurgent
expansions have been mainly applied for small values of coupling parameter g,
while much less attention has been paid to the strong-coupling regime. In this
contribution, we compare the energy values, obtained by directly resumming
generalized Bohr-Sommerfeld quantization conditions, to the strong-coupling
expansion, for which we determine the first few expansion coefficients in
powers of g^(-2/3). Detailed calculations are performed for a wide range of
coupling parameters g and indicate a considerable overlap between the regions
of validity of the weak-coupling resurgent series and of the strong-coupling
expansion. Apart from the analysis of the energy spectrum of the Fokker-Planck
Hamiltonian, we also briefly discuss the computation of its eigenfunctions.
These eigenfunctions may be utilized for the numerical integration of the
(single-particle) time-dependent Schroedinger equation and, hence, for studying
the dynamical evolution of the wavepackets in the double-well-like potentials.Comment: 13 pages; RevTe
Nurses\u27 Alumnae Association Bulletin, December 1968
President\u27s Message
Officers and Committee Chairman
Financial Report
Report to Alumnae Association
Annual Report to Alumnae Association
School of Practical Nursing Report
Student Activities
Nursing Service Staff Association
Letter from Vietnam
Resume of Alumnae Meetings
Ways and Means Report
Social Committee
Building Fund Report
Bulletin Committee Report
Class News
Notice
Probing the Solar Atmosphere Using Oscillations of Infrared CO Spectral Lines
Oscillations were observed across the whole solar disk using the Doppler
shift and line depth of spectral lines from the CO molecule near 4666~nm with
the National Solar Observatory's McMath/Pierce solar telescope. Power,
coherence, and phase spectra were examined, and diagnostic diagrams reveal
power ridges at the solar global mode frequencies to show that these
oscillations are solar p-modes. The phase was used to determine the height of
formation of the CO lines by comparison with the IR continuum intensity phase
shifts as measured in Kopp et al., 1992; we find the CO line formation height
varies from 425 < z < 560 km as we move from disk center towards the solar limb
1.0 > mu > 0.5. The velocity power spectra show that while the sum of the
background and p-mode power increases with height in the solar atmosphere as
seen in previous work, the power in the p-modes only (background subtracted)
decreases with height, consistent with evanescent waves. The CO line depth
weakens in regions of stronger magnetic fields, as does the p-mode oscillation
power. Across most of the solar surface the phase shift is larger than the
expected value of 90 degrees for an adiabatic atmosphere. We fit the phase
spectra at different disk positions with a simple atmospheric model to
determine that the acoustic cutoff frequency is about 4.5 mHz with only small
variations, but that the thermal relaxation frequency drops significantly from
2.7 to 0 mHz at these heights in the solar atmosphere
Quantum statistics of atoms in microstructures
This paper proposes groove-like potential structures for the observation of
quantum information processing by trapped particles. As an illustration the
effect of quantum statistics at a 50-50 beam splitter is investigated. For
non-interacting particles we regain the results known from photon experiments,
but we have found that particle interactions destroy the perfect bosonic
correlations. Fermions avoid each other due to the exclusion principle and
hence they are far less sensitive to particle interactions. For bosons, the
behavior can be explained with simple analytic considerations which predict a
certain amount of universality. This is verified by detailed numerical
calculations.Comment: 18 pages incl. 13 figure
Magnetoacoustic Portals and the Basal Heating of the Solar Chromosphere
We show that inclined magnetic field lines at the boundaries of large-scale convective cells (supergranules) provide "portals" through which low-frequency ( 5 mHz) acoustic waves, which are believed to provide the dominant source of wave heating of the chromosphere. This result opens up the possibility that low-frequency magnetoacoustic waves provide a significant source of energy for balancing the radiative losses of the ambient solar chromosphere
Variably Transmittive, Electronically-Controlled Eyewear
A system and method for flight training and evaluation of pilots comprises electronically activated vision restriction glasses that detect the pilot's head position and automatically darken and restrict the pilot's ability to see through the front and side windscreens when the pilot-in-training attempts to see out the windscreen. Thus, the pilot-in-training sees only within the aircraft cockpit, forcing him or her to fly by instruments in the most restricted operational mode
Deconfinement in the Quark Meson Coupling Model
The Quark Meson Coupling Model which describes nuclear matter as a collection
of non-overlapping MIT bags interacting by the self-consistent exchange of
scalar and vector mesons is used to study nuclear matter at finite temperature.
In its modified version, the density dependence of the bag constant is
introduced by a direct coupling between the bag constant and the scalar mean
field. In the present work, the coupling of the scalar mean field with the
constituent quarks is considered exactly through the solution of the Dirac
equation. Our results show that a phase transition takes place at a critical
temperature around 200 MeV in which the scalar mean field takes a nonzero value
at zero baryon density. Furthermore it is found that the bag constant decreases
significantly when the temperature increases above this critical temperature
indicating the onset of quark deconfinement.Comment: LaTeX/TeX 15 pages (zk2.tex)+ 6 figures in TeX forma
Vanishing Hall Constant in the Stripe Phase of Cuprates
The Hall constant R_H is considered for the stripe structures. In order to
explain the vanishing of R_H in LNSCO at x = 1/8, we use the relation of R_H to
the Drude weight D as well as direct numerical calculation, to obtain results
within the t-J model, where the stripes are imposed via a charge potential and
a staggered magnetic field. The origin of R_H ~ 0 is related to a maximum in D
and the minimal kinetic energy in stripes with a hole filling ~ 1/2. The same
argument indicates on a possibility of R_H ~ 0 in the whole range of static
stripes for x < 1/8.Comment: RevTeX, 4 pages, 5 figure
- …