3,939 research outputs found
Common Ground: Uniting Archaeology and Secondary Social Studies Curricula
Archaeologists have been attempting to establish stronger connections with communities for several decades. Concepts such as stewardship can be presented to a larger audience, and archaeology can be a valuable tool for public education. Public schools across the nation are struggling to improve with limited resources. Archaeology can provide teachers with inexpensive resources that improve student learning while simultaneously helping teachers meet more rigorous standards. Using historical, archaeological, and cultural resources from the World War II Japanese American internment camp, Amache, I created a new supplementary curriculum that focused on the experience of Japanese and Japanese Americans during that era. This thesis presents that curriculum and an accompanying case study that introduced archaeologically based activities in a secondary social studies classroom. Analysis of student responses indicates that supplementing with archaeology had no adverse effects to student exam scores on overall WWII history. In addition many students felt more connected to former Amache internees and their experience
Sphenothallus-Like Fossils from the Martinsburg Formation (Upper Ordovician), Tennessee, USA
Tubular fossils, up to 2 mm in diameter and 60 mm in length, occur rarely in the upper Martinsburg Formation (Upper Ordovician), northeastern Tennessee Appalachians, U.S.A. The fossils are unbranched, straight or slightly bent, occasionally twisted and wrinkled, and not significantly tapered. Orientation of the fossils within shallow-marine tempestites suggests that they represent remains of organisms that were broken, transported, and deposited by storm waves and currents. The fossils are morphologically similar to many of the previously identified species belonging to the genus Sphenothallus, a relatively rare tube-dwelling Paleozoic marine invertebrate. Owing to the limited evidence for distal widening of the tubes, lack of holdfasts, and carbonaceous rather than phosphatic composition, the affinity of these fossils remains uncertain, and we refer to them as Sphenothallus-like
Solar power and policy powerlessness â perceptions of persuasion in distributed residential solar energy policy development
Distributed residential solar energy (photovoltaic) technologies have been praised as a mechanism to not only increase the penetration of renewable energy but engage the community in a clean energy revolution. In spite of this it is unclear how much potential there is for stakeholders to influence processes around the adoption of solar energy, including policy development and regulation. As part of a wider research project assessing the social acceptance of residential solar energy in Western Australia a variety of stakeholders, including public servants, network operators, Members of Parliament, energy advocates, renewable energy industry members and community members, were asked whether they thought they had the potential to influence solar policy. The objective of this research was to highlight positions of influence over policy development. In total 23 interviews with regional Western Australian householders and 32 interviews with members of industry and government were undertaken between May and October 2015. Most respondents believed that they had previously, or could in future, influence solar policy by taking advantage of networks of influence. However, stakeholders perceived as having policy influence did not necessarily demonstrate the capacity to influence policy beyond providing information to decision-makers, namely Cabinet members. Instead, networks of renewable energy advocates, industry and community members could apply political pressure through petitions, media coverage and liaising with parliamentarians to develop support for policy changes. Furthermore, while policies for the promotion of solar energy, and renewable energy more generally, could be implemented at various levels of government, only those policies delivered at the state level could address socio-political barriers to renewable energy adoption. These barriers include: a lack of political will and funding to overcome technical issues with network connection; reductions in fossil fuel subsidies to encourage an âeven playing fieldâ; and removal of regulatory barriers for innovative renewable energy solutions
HPC-driven computational reproducibility
Reproducibility of results is a cornerstone of the scientific method.
Scientific computing encounters two challenges when aiming for this goal.
Firstly, reproducibility should not depend on details of the runtime
environment, such as the compiler version or computing environment, so results
are verifiable by third-parties. Secondly, different versions of software code
executed in the same runtime environment should produce consistent numerical
results for physical quantities. In this manuscript, we test the feasibility of
reproducing scientific results obtained using the IllinoisGRMHD code that is
part of an open-source community software for simulation in relativistic
astrophysics, the Einstein Toolkit. We verify that numerical results of
simulating a single isolated neutron star with IllinoisGRMHD can be reproduced,
and compare them to results reported by the code authors in 2015. We use two
different supercomputers: Expanse at SDSC, and Stampede2 at TACC.
By compiling the source code archived along with the paper on both Expanse
and Stampede2, we find that IllinoisGRMHD reproduces results published in its
announcement paper up to errors comparable to round-off level changes in
initial data parameters. We also verify that a current version of
IlliinoisGRMHD reproduces these results once we account for bug fixes which has
occurred since the original publicationComment: 22 pages, 6 figures, submitted to Classical and Quantum Gravit
The coupling of a young stellar disc with the molecular torus in the Galactic centre
The Galactic centre hosts, according to observations, a number of early-type
stars. About one half of those which are orbiting the central supermassive
black hole on orbits with projected radii 0.03 pc form a coherently
rotating disc. Observations further reveal a massive gaseous torus and a
significant population of late-type stars. In this paper, we investigate, by
means of numerical N-body computations, the orbital evolution of the stellar
disc, which we consider to be initially thin. We include the gravitational
influence of both the torus and the late-type stars, as well as the
self-gravity of the disc. Our results show that, for a significant set of
system parameters, the evolution of the disc leads, within the lifetime of the
early-type stars, to a configuration compatible with the observations. In
particular, the disc naturally reaches a specific - perpendicular - orientation
with respect to the torus, which is indeed the configuration observed in the
Galactic centre. We, therefore, suggest that all the early-type stars may have
been born within a single gaseous disc.Comment: Accepted for publication in MNRAS; 9 pages, 4 figures, 1 tabl
Loads Model Development and Analysis for the F/A-18 Active Aeroelastic Wing Airplane
The Active Aeroelastic Wing airplane was successfully flight-tested in March 2005. During phase 1 of the two-phase program, an onboard excitation system provided independent control surface movements that were used to develop a loads model for the wing structure and wing control surfaces. The resulting loads model, which was used to develop the control laws for phase 2, is described. The loads model was developed from flight data through the use of a multiple linear regression technique. The loads model input consisted of aircraft states and control surface positions, in addition to nonlinear inputs that were calculated from flight-measured parameters. The loads model output for each wing consisted of wing-root bending moment and torque, wing-fold bending moment and torque, inboard and outboard leading-edge flap hinge moment, trailing-edge flap hinge moment, and aileron hinge moment. The development of the Active Aeroelastic Wing loads model is described, and the ability of the model to predict loads during phase 2 research maneuvers is demonstrated. Results show a good match to phase 2 flight data for all loads except inboard and outboard leading-edge flap hinge moments at certain flight conditions. The average load prediction errors for all loads at all flight conditions are 9.1 percent for maximum stick-deflection rolls, 4.4 percent for 5-g windup turns, and 7.7 percent for 4-g rolling pullouts
Infrared to millimetre photometry of ultra-luminous IR galaxies: new evidence favouring a 3-stage dust model
Infrared to millimetre spectral energy distributions have been obtained for
41 bright ultra-luminous infrared galaxies. The observations were carried out
with ISOPHOT between 10 and 200 micron and supplemented for 16 sources with
SCUBA at 450 and 850 micron and with SEST at 1.3 mm. In addition, seven sources
were observed at 1.2 and 2.2 m with the 2.2 m telescope on Calar Alto.
These new SEDs represent the most complete set of infrared photometric
templates obtained so far on ULIRGs in the local universe.Comment: 23 pages, 11 figures, accepted for publication in Astronomy &
Astrophysic
Probing the momentum relaxation time of charge carriers in ultrathin semiconductor layers
We report on a terahertz time-domain technique for measuring the momentum
relaxation time of charge carriers in ultrathin semiconductor layers. The phase
sensitive modulation technique directly provides the relaxation time.
Time-resolved THz experiments were performed on n-doped GaAs and show precise
agreement with data obtained by electrical characterization. The technique is
well suited for studying novel materials where parameters such as the charge
carriers' effective mass or the carrier density are not known a priori
The Opacity of Nearby Galaxies from Counts of Background Galaxies: II. Limits of the Synthetic Field Method
Recently, we have developed and calibrated the Synthetic Field Method (SFM)
to derive the total extinction through disk galaxies. The method is based on
the number counts and colors of distant background field galaxies that can be
seen through the foreground object, and has been successfully applied to NGC
4536 and NGC 3664, two late-type galaxies located, respectively, at 16 and 11
Mpc. Here, we study the applicability of the SFM to HST images of galaxies in
the Local Group, and show that background galaxies cannot be easily identified
through these nearby objects, even with the best resolution available today. In
the case of M 31, each pixel in the HST images contains 50 to 100 stars, and
the background galaxies cannot be seen because of the intrinsic granularity due
to strong surface brightness fluctuations. In the LMC, on the other hand, there
is only about one star every six linear pixels, and the lack of detectable
background galaxies results from a ``secondary'' granularity, introduced by
structure in the wings of the point spread function. The success of the SFM in
NGC 4536 and NGC 3664 is a natural consequence of the reduction of the
intensity of surface brightness fluctuations with distance. When the dominant
confusion factor is structure in the PSF wings, as is the case of HST images of
the LMC, and would happen in M 31 images obtained with a 10-m diffraction-
limited optical telescope, it becomes in principle possible to improve the
detectability of background galaxies by subtracting the stars in the foreground
object. However, a much better characterization of optical PSFs than is
currently available would be required for an adequate subtraction of the wings.
Given the importance of determining the dust content of Local Group galaxies,
efforts should be made in that direction.Comment: 45 pages, 10 Postscript figure
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