3,939 research outputs found

    Common Ground: Uniting Archaeology and Secondary Social Studies Curricula

    Get PDF
    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

    Get PDF
    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 − perceptions of persuasion in distributed residential solar energy policy development

    Get PDF
    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 “even playing field”; and removal of regulatory barriers for innovative renewable energy solutions

    HPC-driven computational reproducibility

    Full text link
    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

    Full text link
    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 ≳\gtrsim 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

    Get PDF
    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

    Get PDF
    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 Ό\mum 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

    Full text link
    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

    Get PDF
    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
    • 

    corecore