33,071 research outputs found

    Autonomous Cars, Electric and Hybrid Cars, and Ridesharing: Perceptions vs. Reality

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    Autonomous Cars, Electric and Hybrid Cars, and Ridesharing are all important new technologies in today\u27s society that can have potentially large impacts on the environment in the future. This study was conducted to determine the differences in perceptions of Gettysburg College students regarding Autonomous Cars, Electric and Hybrid Cars, and Ridesharing and the reality of these topics in the real world. This paper also compares the perceptions of Environmental Studies majors/minors to the perceptions of other majors at Gettysburg College. The primary research was conducted by analyzing questions that were a part of a survey consisting of 16 questions which was administered to Gettysburg College students via Facebook class group pages and the Environmental Studies majors email alias. The study group consisted of 110 students with 31 of them being Environmental Studies majors/minors and 79 of them being non-Environmental Studies majors/minors. It was determined that there were no statistically significant differences between the Environmental Studies majors/minors and students that are other majors/minors at Gettysburg College. From our survey, we found that there is a distinct gap in knowledge on the current and future impacts on the environment from Autonomous Cars, Electric and Hybrid Cars, and Ridesharing. The questions that ask which power method produces more greenhouse gas emissions as well as the questions about the miles per gallon of participants’ personal vehicles were the most accurately answered. Overall, Gettysburg College students regardless of major or minor were found to have mostly inaccurate perceptions on the topics of Autonomous Cars, Electric and Hybrid Cars, and Ridesharing

    Diffuse radio emission in MACS J0025.4−-1222: the effect of a major merger on bulk separation of ICM components

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    Mergers of galaxy clusters are among the most energetic events in the Universe. These events have significant impact on the intra-cluster medium, depositing vast amounts of energy - often in the form of shocks - as well as heavily influencing the properties of the constituent galaxy population. Many clusters have been shown to host large-scale diffuse radio emission, known variously as radio haloes and relics. These sources arise as a result of electron (re-)acceleration in cluster-scale magnetic fields, although the processes by which this occurs are still poorly understood. We present new, deep radio observations of the high-redshift galaxy cluster MACS J0025.4−-1222, taken with the GMRT at 325 MHz, as well as new analysis of all archival ChandraChandra X-ray observations. We aim to investigate the potential of diffuse radio emission and categorise the radio population of this cluster, which has only been covered previously by shallow radio surveys. We produce low-resolution maps of MACS J0025.4−-1222 through a combination of uv-tapering and subtracting the compact source population. Radial surface brightness and mass profiles are derived from the ChandraChandra data. We also derive a 2D map of the ICM temperature. For the first time, two sources of diffuse radio emission are detected in MACS J0025.4−-1222, on linear scales of several hundred kpc. Given the redshift of the cluster and the assumed cosmology, these sources appear to be consistent with established trends in power scaling relations for radio relics. The X-ray temperature map presents evidence of an asymmetric temperature profile and tentative identification of a temperature jump associated with one relic. We classify the pair of diffuse radio sources in this cluster as a pair of radio relics, given their consistency with scaling relations, location toward the cluster outskirts, and the available X-ray data.Comment: 20 pages, 15 figures, accepted for publication in A&

    Stripes in thin ferromagnetic films with out-of-plane anisotropy

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    We examine the T=0 phase diagram of a thin ferromagnetic film with a strong out-of-plane anisotropy in the vicinity of the reorientation phase transition (with Co on Pt as an example). The phase diagram in the anisotropy-applied field plane is universal in the limit where the film thickness is the shortest length scale. It contains uniform fully magnetized and canted phases, as well as periodically nonuniform states: a weakly modulated spin-density wave and strongly modulated stripes. We determine the boundaries of metastability of these phases and point out the existence of a critical point at which the difference between the SDW and stripes vanishes. Out-of-plane magnetization curves exhibit a variety of hysteresis loops caused by the coexistence of one or more phases. Additionally, we study the effect of a system edge on the orientation of stripes. We compare our results with recent experiments.Comment: added references and clarified derivations in response to referee comment

    Transitions in the morphological features, habitat use, and diet of young-of-the-year goosefish (Lophius americanus)

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    This study was designed to improve our understanding of transitions in the early life history and the distribution, habitat use, and diets for young-of-the-year (YOY) goosefish (Lophius americanus) and, as a result, their role in northeastern U.S. continental shelf ecosystems. Pelagic juveniles (>12 to ca. 50 mm total length [TL]) were distributed over most portions of the continental shelf in the Middle Atlantic Bight, Georges Bank, and into the Gulf of Maine. Most individuals settled by 50−85 mm TL and reached approximately 60−120 mm TL by one year of age. Pelagic YOY fed on chaetognaths, hyperiid amphipods, calanoid copepods, and ostracods, and benthic YOY had a varied diet of fishes and benthic crustaceans. Goosefish are widely scattered on the continental shelf in the Middle Atlantic Bight during their early life history and once settled, are habitat generalists, and thus play a role in many continental shelf habi

    Aquisiton and management of reindeer herd data

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    Obtaining and maintaining accurate records of reindeer (Rangifer tarandus) herd data has become a necessary tool for efficient herd management. A computerized record keeping and reporting system was developed due to the speed which which animals were seen at the seasonal handlings. Custom software was written using the dBASE III + data management package to handle the special needs of herd record keeping. The software was then compiled using the Clipper compiler. The resulting program and data were implemented in ramdisk on a Toshiba 3100 microcomputer. Data structures were carefully chosen to provide for recording of tag identification, sex, age, body weight, abnormalities, disease testing, and treatments for each deer. Additionally, fields were provided to maintain records of ongoing biologic experiments. A report generation program was written to provide a current herd status report to the herders

    Control Plane Compression

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    We develop an algorithm capable of compressing large networks into a smaller ones with similar control plane behavior: For every stable routing solution in the large, original network, there exists a corresponding solution in the compressed network, and vice versa. Our compression algorithm preserves a wide variety of network properties including reachability, loop freedom, and path length. Consequently, operators may speed up network analysis, based on simulation, emulation, or verification, by analyzing only the compressed network. Our approach is based on a new theory of control plane equivalence. We implement these ideas in a tool called Bonsai and apply it to real and synthetic networks. Bonsai can shrink real networks by over a factor of 5 and speed up analysis by several orders of magnitude.Comment: Extended version of the paper appearing in ACM SIGCOMM 201

    Flickering in FU Orionis

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    We analyze new and published optical photometric data of FU Orionis, an eruptive pre-main sequence star. The outburst consists of a 5.5 mag rise at B with an e-folding timescale of roughly 50 days. The rates of decline at B and V are identical, 0.015 +- 0.001 mag per yr. Random fluctuations superimposed on this decline have an amplitude of 0.035 +- 0.005 mag at V and occur on timescales of 1 day or less. Correlations between V and the color indices U-B, B-V, and V-R indicate that the variable source has the optical colors of a G0 supergiant. We associate this behavior with small amplitude flickering of the inner accretion disk.Comment: 19 pages of text, 3 tables, and 6 figures to be published in the Astrophysical Journal, 10 March 200
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