5,805 research outputs found
New observations of the low frequency interplanetary radio emissions
Recent Voyager 1 observations reveal reoccurrences of the low frequency interplanetary radio emissions. Three of the new events are weak transient events which rise in frequency from the range of 2-2.5 kHz to about 3 kHz with drift rates of approximately 1.5 kHz/year. The first of the transient events begins in mid-1989 and the more recent pair of events both were first detected in late 1991. In addition, there is an apparent onset of a 2-kHz component of the emission beginning near day 70 of 1991. The new transient emissions are barely detectable on Voyager 1 and are below the threshold of detectability on Voyager 2, which is less sensitive than Voyager 1. The new activity provides new opportunities to test various theories of the triggering, generation, and propagation of the outer heliospheric radio emissions and may signal a response of the source of the radio emissions to the increased solar activity associated with the recent peak in the solar cycle
Lattice density functional theory at finite temperature with strongly density-dependent exchange-correlation potentials
The derivative discontinuity of the exchange-correlation (xc) energy at
integer particle number is a property of the exact, unknown xc functional of
density functional theory (DFT) which is absent in many popular local and
semilocal approximations. In lattice DFT, approximations exist which exhibit a
discontinuity in the xc potential at half filling. However, due to convergence
problems of the Kohn-Sham (KS) self-consistency cycle, the use of these
functionals is mostly restricted to situations where the local density is away
from half filling. Here a numerical scheme for the self-consistent solution of
the lattice KS Hamiltonian with a local xc potential with rapid (or
quasi-discontinuous) density dependence is suggested. The problem is formulated
in terms of finite-temperature DFT where the discontinuity in the xc potential
emerges naturally in the limit of zero temperature. A simple parametrization is
suggested for the xc potential of the uniform 1D Hubbard model at finite
temperature which is obtained from the solution of the thermodynamic Bethe
ansatz. The feasibility of the numerical scheme is demonstrated by application
to a model of fermionic atoms in a harmonic trap. The corresponding density
profile exhibits a plateau of integer occupation at low temperatures which
melts away for higher temperatures.Comment: 14 pages, 11 figure
A unit based approach to adaptations in inclusive classrooms.
Ms. Lawson is an inclusive special education teacher at Ortega Middle School. She has
noticed that to make inclusion “work” for her students, she needs to make the curriculum
accessible for her students through collaboration and adaptations. This year, Ms. Lawson will be
collaborating with Mr. Jackson, an 8th grade English teacher, to facilitate the inclusion of
Amanda, who enjoys movies and talking with her girl friends. Amanda also has an intellectual
disability and is learning content that is at a different level than her peers. John is also in 8th
grade and will be enrolled in Mr. Jackson’s class. John enjoys video games and movies. John
has autism and is also working at a different grade level than his peers. Amanda and John have
been included in general education classes since preschool, but with each passing year the need
for differentiated instruction and curriculum has increased. Ms. Lawson has been working to
design curriculum that meets the needs of each student individually, including Amanda and
John, but is wondering if this piece-meal, one-student-at-a-time approach is effective or efficient
for her, her students, or her general education colleagues
Plasma waves near Saturn: Initial results from Voyager 1
The Voyager 1 encounter with Saturn provided the first opportunity to investigate plasma wave interactions in the magnetosphere of Saturn. An overview of the principal results from the Voyager 1 plasma wave instrument is presented starting with the initial detection of Saturn and ending about four weeks after closest approach. A survey plot of the electric field intensities detected during the Saturn encounter is shown starting shortly before the inbound shock crossing and ending shortly after the outbound magnetopause crossing. Many intense waves were observed in the vicinity of Saturn. To provide a framework for presenting the observations, the results are discussed more or less according to the sequence in which the data were obtained
Plasma diagnostics package. Volume 1: OSS-1 section
This volume (1) of the Plasma Diagnostics Package (PDP) final science report contains a summary of all of the data reduction and scientific analyses which were performed using PDP data obtained on STS-3 as a part of the Office of Space Science first payload (OSS-1). This work was performed during the period of launch, March 22, l982, through June 30, l983. During this period the primary data reduction effort consisted of processing summary plots of the data received by the 14 instruments located on the PDP and submitting these data to the National Space Science Data Center (NSSDC). The scientific analyses during the performance period consisted of general studies which incorporated the results of several of the PDP's instruments, detailed studies which concentrated on data from only one or two of the instruments, and joint studies of beam-plasma interactions with the OSS-1 Fast Pulse Electron Generator (FPEG) of the Vehicle Charging and Potential Investigation (VCAP). Internal reports, published papers and oral presentations which involve PDP/OSS-1 data are listed in Sections 3 and 4. A PDP/OSS-1 scientific results meeting was held at the University of Iowa on April 19-20, 1983. This meeting was attended by most of the PDP and VCAP investigators and provided a forum for discussing and comparing the various results, particularly with regard to the shuttle orbiter environment. One of the most important functional objectives of the PDP on OSS-1 was to characterize the orbiter environment
Educational Placement of Students with Autism: The Impact of State of Residence
Typically, child characteristics such as IQ and severity of autism symptoms are thought
to determine educational placement. The present study examines external factors,
including state of residence and state funding formulas, to determine their potential
influence on placement outcomes. Findings reveal that considerable variations exist
among states in placing students with ASD in inclusive, mainstreaming, self-contained,
and separate schools, suggesting that external to the child factors play a major role in
educational placement decisions. Further, states in the Eastern US tend to have more
restrictive placement rates than states in the Western US. State special education funding
was found to have a minimal impact on placement outcomes
Plasma diagnostics package. Volume 2: Spacelab 2 section. Part B: Thesis projects
This volume (2), which consists of two parts (A and B), of the Plasma Diagnostics Package (PDP) Final Science Report contains a summary of all of the data reduction and scientific analyses which were performed using PDP data obtained on STS-51F as a part of the Spacelab 2 (SL-2) payload. This work was performed during the period of launch, July 29, 1985, through June 30, 1988. During this period the primary data reduction effort consisted of processing summary plots of the data received by 12 of the 14 instruments located on the PDP and submitting these data to the National Space Science Data Center (NSSDC). Three Master's and three Ph.D. theses were written using PDP instrumentation data. These theses are listed in Volume 2, Part B
Direction finding measurements of auroral kilometric radiation
Direction finding measurements with plasma wave experiments onboard the Hawkeye-1 and IMP-8 satellites were used to locate the source region of auroral kilometric radiation. The radiation exhibits peak intensities between about 100 kHz and 300 kHz, and emits intense sporadic bursts lasting for between one half hour to several hours. The total power emitted in this frequency range exceeds 10 to the 9th power watts at peak intensity. The occurrence of the radiation is known to be closely associated with bright auroral arcs which occur in the local evening auroral regions
Large-scale solar wind flow around Saturn's nonaxisymmetric magnetosphere
The interaction between the solar wind and a magnetosphere is fundamental to
the dynamics of a planetary system. Here, we address fundamental questions on
the large-scale magnetosheath flow around Saturn using a 3D magnetohydrodynamic
(MHD) simulation. We find Saturn's polar-flattened magnetosphere to channel
~20% more flow over the poles than around the flanks at the terminator.
Further, we decompose the MHD forces responsible for accelerating the
magnetosheath plasma to find the plasma pressure gradient as the dominant
driver. This is by virtue of a high-beta magnetosheath, and in turn, the
high-MA bow shock. Together with long-term magnetosheath data by the Cassini
spacecraft, we present evidence of how nonaxisymmetry substantially alters the
conditions further downstream at the magnetopause, crucial for understanding
solar wind-magnetosphere interactions such as reconnection and shear
flow-driven instabilities. We anticipate our results to provide a more accurate
insight into the global conditions upstream of Saturn and the outer planets.Comment: Accepted for publication in Journal of Geophysical Journal: Space
Physic
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