78 research outputs found

    Signal-to-noise ratio enhanced electrode configurations for magnetoelectric cantilever sensors

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    Magnetoelectric cantilevers consisting of strain-coupled magnetostrictive and piezoelectric (PE) layers are applicable to magnetic-fi eld sens- ing. For the fi rst bending mode, the magnetic fi eld-induced stress distribution is of equal sign along the cantilever length. Thus, a plate- capacitor electrode configuration encompassing the complete PE layer may be used for collecting the strain-induced charge. For higher order modes, stress regions of the opposite sign occur in the cantilever length direction. To prevent charge cancellation and to harvest the piezo- electric induced charge effi ciently, segmented electrodes are employed. This study investigates the effect of the electrode confi gurationon the signal-to-noise ratio (SNR) for higher order bending modes. The charges collected by the electrodes are calculated using a fi nite element method simulation considering the mechanical, electrical, and magnetic properties of the cantilever. By combination with an analytic noise model, taking into account the sensor and amplifi er noise sources, the SNR is obtained. We analyze a 3 mm long, 1 mm wide, and 50 μm thick silicon cantilever with layers of 2 μm magnetostrictive soft amorphous metal (FeCoSiB) and 2 μm piezoelectric aluminum nitride. We demonstrate that an SNR-optimized electrode design yields an SNR improvement by 2.3 dB and 2.4 dB for the second and third bending modes compared to a signal optimized design

    Local unemployment changes the springboard effect of low pay: Evidence from England

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    There is considerable debate on whether the employment and earnings prospects are better for those on low pay or for the unemployed. Low-pay work tends to be undertaken more locally but no empirical analysis has focused on how local opportunities alter prospects. Using Understanding Society data for England matched with local unemployment rates, we estimate dynamic random effects panel models, which show robust evidence that the future unemployment risk is lower for those who are currently on low pay compared to those who are currently unemployed. The low-paid also have a higher chance than the unemployed of becoming higher-paid. These findings are most marked in neighbourhoods with high unemployment

    Does neighbourhood unemployment affect the springboard effect of low pay?

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    There is considerable debate on whether the employment and earnings prospects are better for those on low pay or for the unemployed. We use Understanding Society data for England and estimate dynamic random effects panel models which show robust evidence that the future unemployment risk is lower for those who are currently on low pay compared to those who are currently unemployed and the low-paid also have a higher chance than the unemployed of becoming higher-paid. These findings are most marked in neighbourhoods with high unemployment which is attributable to the much poorer prospects of the unemployed in these neighbourhoods

    Sea ice dynamics across the Mid-Pleistocene transition in the Bering Sea.

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    Sea ice and associated feedback mechanisms play an important role for both long- and short-term climate change. Our ability to predict future sea ice extent, however, hinges on a greater understanding of past sea ice dynamics. Here we investigate sea ice changes in the eastern Bering Sea prior to, across, and after the Mid-Pleistocene transition (MPT). The sea ice record, based on the Arctic sea ice biomarker IP25 and related open water proxies from the International Ocean Discovery Program Site U1343, shows a substantial increase in sea ice extent across the MPT. The occurrence of late-glacial/deglacial sea ice maxima are consistent with sea ice/land ice hysteresis and land-glacier retreat via the temperature-precipitation feedback. We also identify interactions of sea ice with phytoplankton growth and ocean circulation patterns, which have important implications for glacial North Pacific Intermediate Water formation and potentially North Pacific abyssal carbon storage

    Using computer simulation to aid the research of drilling processes

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    Drilling wells is one of the primary methods used for mineral exploration. Scientific studies have aimed at improving the technical and economic aspects of drilling because of the current competitive economic conditions. Note that the primary topic of these studies has been developing new effective rock-cutting tools. To design a new rock-cutting tool, a thorough, reliable, and accurate study of the processes that occur during drilling is necessary. During drilling, mechanical, hydraulic, thermal, and chemical phenomena, which are interdependent and affect the performance of a drilling tool, simultaneously occur; therefore, a systematic, integrated approach is required for studying drilling processes. Field-based and laboratory experiments are quite tedious to perform and require high material costs, and it is often not possible to separately evaluate small elements of the drilling model. Therefore, computer simulation is an important research tool that enables accurate and reliable visualization of even small parts of the model. The aim. The aim of this study is to examine the potential for computer simulation of the processes that occur during drilling. Objective. In this study, we evaluated the simulation features of various software products, such as KOMPAS-3D, ANSYS, Delphi, and LabVIEW, for their utility in studying the processes that occur during drilling. The possibility of computer simulation for studying drilling processes, including its advantages and disadvantages, are demonstrated. The results are obtained from a model that simulates a rock cutting tool. The main uses of the rock cutting tool are outlined, and the drilling simulation development is planned. Choice of research method. The study of the capabilities of existing modern software products, for use in drilling process research, is carried out by an analytical review method

    Escape of methane gas from the seabed along the West Spitsbergen continental margin

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    More than 250 plumes of gas bubbles have been discovered emanating from the seabed of the West Spitsbergen continental margin, in a depth range of 150-400 m, at and above the present upper limit of the gas hydrate stability zone (GHSZ). Some of the plumes extend upward to within 50 m of the sea surface. The gas is predominantly methane. Warming of the northward-flowing West Spitsbergen current by 1°C over the last thirty years is likely to have increased the release of methane from the seabed by reducing the extent of the GHSZ, causing the liberation of methane from decomposing hydrate. If this process becomes widespread along Arctic continental margins, tens of Teragrams of methane per year could be released into the ocean

    Measurement of the J/ψJ/\psi radiative decay into f0(1270)γf^0(1270)\gamma

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    The J/ψ decay modes f 0 (1270)γ and ρπ have been studied in e + e − collision at 3.1 GeV center of mass energy leading to the π + π − γ and π + π − π 0 final states. The f 0 γ decay branching ratio is measured to be (0.20 ± 0.07) × 10 −2 , a value comparable to the J/ψ radiative decay rates into the ηγ and η′γ channels. The J/ψ decay branching ratio into ϱπ is measured to be (1.6 ± 0.4) × 10 −2

    Measurement of the JψJ\psi radiative decay into F0F_0 (1270) γ\gamma

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    The J/ψ decay modes f 0 (1270)γ and ρπ have been studied in e + e − collision at 3.1 GeV center of mass energy leading to the π + π − γ and π + π − π 0 final states. The f 0 γ decay branching ratio is measured to be (0.20 ± 0.07) × 10 −2 , a value comparable to the J/ψ radiative decay rates into the ηγ and η′γ channels. The J/ψ decay branching ratio into ϱπ is measured to be (1.6 ± 0.4) × 10 −2
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