607 research outputs found

    Composite Structures using Asphalt Based Roofing Scrap Materials: EIERA -- Final Report

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    The uses of recycled materials in composites provide the potential for large cost savings and a solution to the ever-growing disposal problem. Shingles contain petroleum based binders and fillers, which used as a valuable resource in composite production. Composites offer inherent advantages over traditional materials in regard to corrosion resistance, design flexibility and extended service life. Use of scrap-roofing shingles as a core material in glass fiber reinforced composite materials offer potential low cost composite products such as sound barrier system, railroad ties and other building materials including blocks. In the present work, processes have been developed for shredding scrap roof shingles, for making shingle blocks, and for filling hollow composite tubes. Mechanical testing was performed to compare the performance of filled composite tubes to hollow tubes and oak wood beams. Filled tubes show improvement in ultimate flexural strength by preventing buckling and crushing. Tests were also conducted to evaluate the sound attenuation capability of recycled shingle walls. It was observed that the mean sound level at the backside of the wall, measured in decibels, was greatly reduced and shows potential use for recycled shingles in a sound barrier system. University of Missouri-Rolla has collaborated with Future Tek Inc. and Lemay Center for Composites Technology for successful completion of this project. The economic benefits are truly immense. This project will impact the community by diverting thousands of tons of shingles into usable products with a real economic impact

    Needed Research on the Englishes of Appalachia

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    Information about the 79th annual meeting of the Southeastern Conference on Linguistics (SECOL) organized by Jennifer Cramer at the University of Kentucky on April 2012 in Lexington, Kentucky. Topics discussed at the meeting includes current state of research studies on linguistic processes in Appalachia, traditional dialectological and ethnographic. The meeting also featured panel experts including Bridget L. Anderson, Michael Montgomery and Walt Wolfram

    The Green Bank Northern Celestial Cap Pulsar Survey - I: Survey Description, Data Analysis, and Initial Results

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    We describe an ongoing search for pulsars and dispersed pulses of radio emission, such as those from rotating radio transients (RRATs) and fast radio bursts (FRBs), at 350 MHz using the Green Bank Telescope. With the Green Bank Ultimate Pulsar Processing Instrument, we record 100 MHz of bandwidth divided into 4,096 channels every 81.92 μs\mu s. This survey will cover the entire sky visible to the Green Bank Telescope (δ>40\delta > -40^\circ, or 82% of the sky) and outside of the Galactic Plane will be sensitive enough to detect slow pulsars and low dispersion measure (<<30 pccm3\mathrm{pc\,cm^{-3}}) millisecond pulsars (MSPs) with a 0.08 duty cycle down to 1.1 mJy. For pulsars with a spectral index of -1.6, we will be 2.5 times more sensitive than previous and ongoing surveys over much of our survey region. Here we describe the survey, the data analysis pipeline, initial discovery parameters for 62 pulsars, and timing solutions for 5 new pulsars. PSR J0214++5222 is an MSP in a long-period (512 days) orbit and has an optical counterpart identified in archival data. PSR J0636++5129 is an MSP in a very short-period (96 minutes) orbit with a very low mass companion (8 MJM_\mathrm{J}). PSR J0645++5158 is an isolated MSP with a timing residual RMS of 500 ns and has been added to pulsar timing array experiments. PSR J1434++7257 is an isolated, intermediate-period pulsar that has been partially recycled. PSR J1816++4510 is an eclipsing MSP in a short-period orbit (8.7 hours) and may have recently completed its spin-up phase.Comment: 18 pages, 10 figures, 5 tables, accepted by Ap

    Sex differences in perceived risk and testing experience of HIV in an urban fishing setting in Ghana

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    The concept of neighborhood remains important in criminology but there is an increasing academic interest in the potential impact of the Modifiable Areal Unit Problem (MAUP) on neighborhood based studies. In the present study data over arson from the Swedish rescue services 2007-2012 have been employed to analyze MAUP in the city of Malmö, Sweden. The city has been divided into 50*50 meter pixels as micro-places (n=64540) which have been assigned a value for arson from frequency of arson within the pixel. The analysis is based on a comparison of two types of administrative geographical units alongside 40 randomly generated sets of thiessen polygon geographical units. Empty two-level hierarchical regression models with the micro-places as level 1 unit have been used to calculate Intra-Class Correlations (ICC) separately with each of the 42 different geographical units of analysis as level 2 units. The analysis is repeated with two alternative methods, kernel density and euclidian distance, to calculate a value for each micro-place. Results show that administrative geographical units of analysis in some cases just are marginally better than geographical units with random boundaries if the basic urban structure is taken into account

    The Green Bank Northern Celestial Cap Pulsar Survey II: The Discovery and Timing of Ten Pulsars

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    We present timing solutions for ten pulsars discovered in 350 MHz searches with the Green Bank Telescope. Nine of these were discovered in the Green Bank Northern Celestial Cap survey and one was discovered by students in the Pulsar Search Collaboratory program in analysis of drift-scan data. Following discovery and confirmation with the Green Bank Telescope, timing has yielded phase-connected solutions with high precision measurements of rotational and astrometric parameters. Eight of the pulsars are slow and isolated, including PSR J0930-2301, a pulsar with nulling fraction lower limit of \sim30\% and nulling timescale of seconds to minutes. This pulsar also shows evidence of mode changing. The remaining two pulsars have undergone recycling, accreting material from binary companions, resulting in higher spin frequencies. PSR J0557-2948 is an isolated, 44 \rm{ms} pulsar that has been partially recycled and is likely a former member of a binary system which was disrupted by a second supernova. The paucity of such so-called `disrupted binary pulsars' (DRPs) compared to double neutron star (DNS) binaries can be used to test current evolutionary scenarios, especially the kicks imparted on the neutron stars in the second supernova. There is some evidence that DRPs have larger space velocities, which could explain their small numbers. PSR J1806+2819 is a 15 \rm{ms} pulsar in a 44 day orbit with a low mass white dwarf companion. We did not detect the companion in archival optical data, indicating that it must be older than 1200 Myr.Comment: 9 pages, 5 figure

    The Green Bank North Celestial Cap Pulsar Survey. IV: Four New Timing Solutions

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    We present timing solutions for four pulsars discovered in the Green Bank Northern Celestial Cap (GBNCC) survey. All four pulsars are isolated with spin periods between 0.26\,s and 1.84\,s. PSR J0038-2501 has a 0.26\,s period and a period derivative of 7.6×1019ss1{7.6} \times {10}^{-19}\,{\rm s\,s}^{-1}, which is unusually low for isolated pulsars with similar periods. This low period derivative may be simply an extreme value for an isolated pulsar or it could indicate an unusual evolution path for PSR J0038-2501, such as a disrupted recycled pulsar (DRP) from a binary system or an orphaned central compact object (CCO). Correcting the observed spin-down rate for the Shklovskii effect suggests that this pulsar may have an unusually low space velocity, which is consistent with expectations for DRPs. There is no X-ray emission detected from PSR J0038-2501 in an archival swift observation, which suggests that it is not a young orphaned CCO. The high dispersion measure of PSR J1949+3426 suggests a distance of 12.3\,kpc. This distance indicates that PSR J1949+3426 is among the most distant 7% of Galactic field pulsars, and is one of the most luminous pulsars.Comment: 7 pages, 5 figure

    The bolometric focal plane array of the Polarbear CMB experiment

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    The Polarbear Cosmic Microwave Background (CMB) polarization experiment is currently observing from the Atacama Desert in Northern Chile. It will characterize the expected B-mode polarization due to gravitational lensing of the CMB, and search for the possible B-mode signature of inflationary gravitational waves. Its 250 mK focal plane detector array consists of 1,274 polarization-sensitive antenna-coupled bolometers, each with an associated lithographed band-defining filter. Each detector's planar antenna structure is coupled to the telescope's optical system through a contacting dielectric lenslet, an architecture unique in current CMB experiments. We present the initial characterization of this focal plane

    A re-investigation of the path of carbon in photosynthesis utilizing GC/MS methodology. Unequivocal verification of the participation of octulose phosphates in the pathway

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    A GC/EIMS/SIM methodology has been developed to re-examine the path of carbon in photosynthesis. Exposing isolated spinach chloroplasts to (13)CO(2 )on a solid support for a defined period followed by quenching and work-up provided a mixture of labelled sugar phosphates. After enzymatic dephosphorylation and derivatization, the Mox-TMS sugars were analysed using the above method. The purpose of the study was to try to calculate the atom% enrichment of (13)C in as many of the individual carbons in each of the derivatized sugars as was practical using diagnostic fragment ions. In the event, only one 45 s experiment provided sufficient data to enable a range of enrichment values to be calculated. This confirmed that D-glycero-D-altro-octulose phosphate was present in the chloroplasts and was heavily labelled in the C4, C5 and C6 positions, in keeping with the hypothesis that it had an inclusive role and a labelling pattern consistent with a new modified pathway of carbon in photosynthesis
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