11,729 research outputs found

    Water Fun at Exploration Station

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    This report documents the design and fabrication processes involved for the creation of an interactive science exhibit for the Grover Beach Exploration Station. This is a student-led senior project advised by Sarah Harding, professor of mechanical engineering, as a part of California Polytechnic State University in San Luis Obispo’s mechanical engineering program. The final product is a fully functioning, durable system that is capable of pumping and recycling water throughout use when users are in its vicinity. The exhibit is to be considered in 4 main subsystems: basin, plumbing, frame, and sleep mode system. A fiberglass basin that holds all the water in the exhibit sits recessed inside a welded steel frame. Water is pumped through the bottom of the basin from within an enclosed storage area inside the frame, and is recycled back into the water reservoir by placement of two weir valves. A submersible pump powers the exhibit, and is controlled by passive infrared sensors that activate when human presence is sensed within 15ft. While the manufacturing process did reach completion, testing and verification did not. However, proposed testing plans are still included in the appendices of the report for informational purposes. Divided into distinct sections, this report will enlighten the reader on each part of the design process. First, background research and preliminary design explains the methodology of developing the vision of the final design. Next, different design analysis techniques are given for each respective subsystem of the proposed exhibit. An in-depth description for manufacturing and testing of the completed exhibit is given for each subsystem. Finally, recommendations are given for future improvements to the exhibit, and what kinds of different decisions would be made in the design process if given a second iteration

    Far Ultraviolet Spectroscopic Explorer Survey of Magellanic Cloud Supernova Remnants

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    We report the progress to date from an ongoing unbiased ultraviolet survey of supernova remnants in the Magellanic Clouds using the Far Ultraviolet Spectroscopic Explorer (FUSE) satellite. This survey is obtaining spectra of a random large sample of Magellanic Cloud supernova remnants with a broad range of radio, optical, and X-ray properties. To date, 39 objects have been observed in the survey (38 in the LMC and one in the SMC) and 15 have been detected, a detection rate of nearly 40%. Our survey has nearly tripled the number of UV-detected SNRs in the Magellanic Clouds (from 8 to 22). Because of the diffuse source sensitivity of FUSE, upper limits on non-detected objects are quite sensitive in many cases. Estimated total luminosities in O~VI span a broad range from considerably brighter to many times fainter than the inferred soft X-ray luminosities, indicating that O~VI can be an important and largely unrecognized coolant in certain objects. We compare the optical and X-ray properties of the detected and non-detected objects but do not find a simple indicator for ultraviolet detectability. Non-detections may be due to clumpiness of the emission, high foreground extinction, slow shocks whose emission gets attenuated by the Magellanic interstellar medium, or a combination of these effects.Comment: 34 pages, 26 figures in 8 separate JPG figure files; the characteristics of individual detected supernova remnants are summarized in an Appendi

    XMM-Newton Witness of M86 X-ray Metamorphosis

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    The environmental influence of cluster media on its member galaxies, known as Butcher--Oemler effect, has recently been subject to revision due to numerous observations of strong morphological transformations occurring outside the cluster virial radii, caused by some unidentified gas removal processes. In this context we present new XMM-Newton observations of M86 group. The unique combination of high spatial and spectral resolution and large field of view of XMM-Newton allows an in-depth investigation of the processes involved in the spectacular disruption of this object. We identify a possible shock with Mach number of ~1.4 in the process of crushing the galaxy in the North-East direction. The latter is ascribed to the presence of a dense X-ray emitting filament, previously revealed in the RASS data. The shock is not associated with other previously identified features of M86 X-ray emission, such as the plume, the north-eastern arm and the southern extension, which are found to have low entropy, similar to the inner 2 kpc of M86. Finally, mere existence of the large scale gas halo around the M86 group, suggests that the disruptions of M86's X-ray halo may be caused by small-scale types of interactions such as galaxy-galaxy collisions.Comment: 11 pages, A&A in pres

    A simple model for electron plasma heating in supernova remnants

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    Context: Multiwavelength observations of supernova remnants can be explained within the framework of diffusive shock acceleration theory, which allows effective conversion of the explosion energy into cosmic rays. Although the models of nonlinear shocks describe reasonably well the nonthermal component of emission, certain issues, including the heating of the thermal electron plasma and the related X-ray emission, still remain open. Methods: Numerical solution of the equations of the Chevalier model for supernova remnant evolution, coupled with Coulomb scattering heating of the electrons. Results: The electron temperature and the X-ray thermal Bremsstrahlung emission from supernova remnants have been calculated as functions of the relevant parameters. Since only the Coulomb mechanism was considered for electron heating, the values obtained for the electron temperatures should be treated as lower limits. Results from this work can be useful to constrain model parameters for observed SNRs.Comment: Accepted to A&A as a research not

    Epilepsy, cognitive deficits and neuroanatomy in males with ZDHHC9 mutations.

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    OBJECTIVE: Systematic investigation of individuals with intellectual disability after genetic diagnosis can illuminate specific phenotypes and mechanisms relevant to common neurodevelopmental disorders. We report the neurological, cognitive and neuroanatomical characteristics of nine males from three families with loss-of-function mutations in ZDHHC9 (OMIM #300799). METHODS: All known cases of X-linked intellectual disability (XLID) due to ZDHHC9 mutation in the United Kingdom were invited to participate in a study of neurocognitive and neuroimaging phenotypes. RESULTS: Seven out of nine males with ZDHHC9 mutations had been diagnosed with epilepsy, exceeding epilepsy risk in XLID comparison subjects (P = 0.01). Seizure histories and EEG features amongst ZDHHC9 mutation cases shared characteristics with rolandic epilepsy (RE). Specific cognitive deficits differentiated males with ZDHHC9 mutations from XLID comparison subjects and converged with reported linguistic and nonlinguistic deficits in idiopathic RE: impaired oromotor control, reduced verbal fluency, and impaired inhibitory control on visual attention tasks. Consistent neuroanatomical abnormalities included thalamic and striatal volume reductions and hypoplasia of the corpus callosum. INTERPRETATION: Mutations in ZDHHC9 are associated with susceptibility to focal seizures and specific cognitive impairments intersecting with the RE spectrum. Neurocognitive deficits are accompanied by consistent abnormalities of subcortical structures and inter-hemispheric connectivity. The biochemical, cellular and network-level mechanisms responsible for the ZDHHC9-associated neurocognitive phenotype may be relevant to cognitive outcomes in RE.This study was funded by the Wellcome Trust/Academy of Medical Sciences (Starter Grant for Clinical Lecturers to K. B.). K. B. is funded by the National Institute of Health Research (Academic Clinical Lectureship). J. B. and D. A. are funded by an MRC UK intramural programme (MCA0606- 5PQ41). G. S. is funded by Wellcome Trust project grant (WT079326AIA) and a James S. McDonnell Foundation Understanding Human Cognition Scholar Award. F. L. R. is funded by the National Institute of Health Research (Cambridge Biomedical Research Centre).This is the final published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1002/acn3.196/full

    OVII and OVIII line emission in the diffuse soft X-ray background: heliospheric and galactic contributions

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    We study the 0.57 keV (O VII triplet) and 0.65 keV (O VIII) diffuse emission generated by charge transfer collisions between solar wind (SW) oxygen ions and interstellar H and He neutral atoms in the inner Heliosphere. These lines which dominate the 0.3-1.0 keV energy interval are also produced by hot gas in the galactic halo (GH) and possibly the Local Interstellar Bubble (LB). We developed a time-dependent model of the SW Charge-Exchange (SWCX) X-ray emission, based on the localization of the SW Parker spiral at each instant. We include input SW conditions affecting three selected fields, as well as shadowing targets observed with XMM-Newton, Chandra and Suzaku and calculate X-ray emission fot O VII and O VIII lines. We determine SWCX contamination and residual emission to attribute to the galactic soft X-ray background. We obtain ground level intensities and/or simulated lightcurves for each target and compare to X-ray data. The local 3/4 keV emission (O VII and O VIII) detected in front of shadowing clouds is found to be entirely explained by the CX heliospheric emission. No emission from the LB is needed at these energies. Using the model predictions we subtract the heliospheric contribution to the measured emission and derive the halo contribution. We also correct for an error in the preliminary analysis of the Hubble Deep Field North (HDFN).Comment: 21 pages (3 on-line), 10 figures (4 on-line), accepted for publication in Astronomy and Astrophysic

    The i-School movement

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    No Abstract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/57317/1/14504301131_ftp.pd
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