2,694 research outputs found

    Response Fibre Bragg Grating (FBG) strain sensors embedded at different locations through the thickness around a delamination in a composite lamina

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    A few FBG strain sensors were embedded at a vicinity of delamination of a laminated composite plate. Reflected spectra of FBG sensors which located in the same layer as the delamination and one layer above the delamination were investigated in order to understand the change of the reflected spectra due to stress concentrations at the delamination. The reflected waveforms of sensors were broadened with the increase of loading, as expected. A considerable difference in the response of two sensors was observed during both uniaxial and flexural loading. These differences show that the FBG sensors are capable of capturing the precise nature of the delamination under various loading conditions. Further, these observations provide evidence of the feasibility of using FBG sensor responses obtained from various locations allows the location of the delamination to be determined. This paper details some new and interesting findings of the use of spectral shapes and strain measurements from embedded FBG sensors in damage detection

    Pesticide Properties that Affect Water Quality

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    16 pp., 9 tables, 6 illustrationsIn order to keep our water supplies safe from pesticide contamination, we must understand which pesticide properties affect water quality, and how. The subject is complex, as properties such as pesticide class, formulation, toxicity, dose, effective dose, persistence, volatility, water solubility, and soil adsorption all must be considered. This publication interprets those characteristics and explains the interaction of chemicals with surface and ground waters

    The Impact of Eruption Source Parameter Uncertainties on Ash Dispersion Forecasts During Explosive Volcanic Eruptions

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    Volcanic ash in the atmosphere is a hazard to aviation. To predict which areas of airspace are most likely to be affected by the presence of ash, Volcanic Ash Advisory Centers (VAACs) use observations and atmospheric dispersion models. These models are initialized with, among other parameters, a mass eruption rate (MER), which quantifies the emission rate into the atmosphere at the source. This influences the predicted spatial–temporal evolution and concentration of the ash cloud. Different models are available to estimate MER from the volcanic plume height and some models also include the weather conditions (e.g., wind speed). The REFIR software tool uses time‐series of plume height estimated from observations and weather data to provide estimates of MER through time. Here we present an updated version of REFIR that can now be used also to calculate MER for past eruptions and produce output parameters in a format suitable for use with the NAME dispersion model (UK Met Office—London VAAC). We also investigate how uncertainty in input parameters is propagated through to dispersion model output. Our results show that a +/−1 km uncertainty on a 6 km high plume can result in the affected area ranging by a factor of three between the minimum and maximum estimates. Additionally, we show that using wind‐affected plume models results in affected areas that are five times larger than using no‐wind‐affected models. This demonstrates the sensitivity of MER to the type of plume model chosen (no‐wind‐ vs. wind‐affected)

    Geology of Tindfjallajökull volcano, Iceland

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    The geology of Tindfjallajökull volcano, southern Iceland, is presented as a 1:50,000 scale map. Field mapping was carried out with a focus on indicators of past environments. A broad stratocone of interbedded fragmental rocks and lavas was constructed during Tindfjallajökull’s early development. This stratocone has been dissected by glacial erosion and overlain by a variety of mafic to silicic volcanic landforms. Eruption of silicic magma, which probably occurred subglacially, constructed a thick pile of breccia and lava lobes in the summit area. Mafic to intermediate flank eruptions continued through to the end of the last glacial period, producing lavas, hyaloclastite-dominated units and tuyas that preserve evidence of volcano-ice interactions. The Thórsmörk Ignimbrite, a regionally important chronostratigraphic marker, is present on the SE flank of the volcano. The geological mapping of Tindfjallajökull gives insights into the evolution of stratovolcanoes in glaciated regions and the influence of ice in their development

    The C-Band All-Sky Survey: Instrument design, status, and first-look data

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    The C-Band All-Sky Survey (C-BASS) aims to produce sensitive, all-sky maps of diffuse Galactic emission at 5 GHz in total intensity and linear polarization. These maps will be used (with other surveys) to separate the several astrophysical components contributing to microwave emission, and in particular will allow an accurate map of synchrotron emission to be produced for the subtraction of foregrounds from measurements of the polarized Cosmic Microwave Background. We describe the design of the analog instrument, the optics of our 6.1 m dish at the Owens Valley Radio Observatory, the status of observations, and first-look data.Comment: 10 pages, 11 figures, published in Proceedings of SPIE MIllimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy V (2010), Vol. 7741, 77411I-1 - 77411I-1

    Seabed mapping for the 21st century : the Marine Environmental Mapping Programme (MAREMAP): preface

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    During the 1970s and 1980s, the British Geological Survey (BGS) carried out systematic surveys of the seabed and subseabed around Britain, as part of a Government-funded programme to map the UK Continental Shelf (UKCS). Using an array of sampling, coring and seismic profiling equipment, the programme resulted in a series of geological maps and scientific publications which described the sediments at the seafloor, the sediments deposited during the Quaternary glaciations, and the older sedimentary, igneous and metamorphic rocks. These systematic surveys of the UKCS were followed during the 1990s by BGS and industry co-funded surveys in the deep-water areas to the west of the UK, such as the Rockall Trough and Plateau; although here, the density of sampling, shallow boreholes and seismic surveys was significantly reduced

    A Prediction for the 4-Loop \beta Function

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    We predict that the four-loop contribution \beta_3 to the QCD \beta function in the MS-bar prescription is given by \beta_3\simeq 23,600(900) - 6,400(200) N_f + 350(70) N_f^2 + 1.5 N_f^3, where N_f is the number of flavours and the coefficient of N_f^3 is an exact result from large-N_f expansion. In the phenomenologically-interesting case N_f=3, we estimate \beta_3 = (7.6 \pm 0.1) x 10^3. We discuss our estimates of the errors in these QCD predictions, basing them on the demonstrated accuracy of our method in test applications to the O(N) \Phi^4 theory, and on variations in the details of our estimation method, which goes beyond conventional Pade approximants by estimating and correcting for subasymptotic deviations from exact results.Comment: 11 pages, LaTeX, including 2 figures in 3 ps files; requires epsfig.sty; added comparison with recent exact result

    Scalable background-limited polarization-sensitive detectors for mm-wave applications

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    We report on the status and development of polarization-sensitive detectors for millimeter-wave applications. The detectors are fabricated on single-crystal silicon, which functions as a low-loss dielectric substrate for the microwave circuitry as well as the supporting membrane for the Transition-Edge Sensor (TES) bolometers. The orthomode transducer (OMT) is realized as a symmetric structure and on-chip filters are employed to define the detection bandwidth. A hybridized integrated enclosure reduces the high-frequency THz mode set that can couple to the TES bolometers. An implementation of the detector architecture at Q-band achieves 90% efficiency in each polarization. The design is scalable in both frequency coverage, 30-300 GHz, and in number of detectors with uniform characteristics. Hence, the detectors are desirable for ground-based or space-borne instruments that require large arrays of efficient background-limited cryogenic detectors.Comment: 7 pages, 3 figures, Presented at SPIE Astronomical Telescopes and Instrumentation 2014: Millimeter, Submillimeter, and Far-Infrared Detectors and Instrumentation for Astronomy VII. To be published in Proceedings of SPIE Volume 915

    The Ursinus Weekly, February 27, 1961

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    Student-faculty show to climax charity drive • ICG holds banquet at Immaculata • Dr. Elmer H. Funk addresses students • Power lines snap, disrupt campus • YM-YWCA plans fireside chats, first will be held on March 1 • Jun Kawashima addresses PSEA on Japan\u27s education • WSGA plans two demonstrations • Meistersingers open season at Faith Church • Frosh girls, reps receive colors on February 23 • U.C. students dine with Republicans • AF recruiter offers ACPP applications • International Relations Club to hear speaker on Finland • Joan Meszaros elected Spring Festival queen • Jazz festival in Fla. over recess • Placement Office posts job listing • Newman Club to hold next meeting on March 6 • Editorial: Apathy again • Eichmann: Perhaps a case of injustice • Northbound • From the continent to the cottage • Book review: The same door • Chestnut Hill falls to badminton team • Girls\u27 swimming team defeats Beaver 44-21 • Thinclads have practice meet with Delaware • Intramural corner • Lassies cop two during past week; Crosley stars • Basketball team split; End with 6-11 season • Grapplers win 2, down Drexel, PMC • Greek gleanings • Letters to the editor • Like I went to a work camphttps://digitalcommons.ursinus.edu/weekly/1334/thumbnail.jp
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