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Schuler J.,California Institute of Technology | Pugh D.J.,University of Cambridge | Pugh D.J.,Now Technologies | Hauksson E.,California Institute of Technology | And 3 more authors.
Journal of Geophysical Research: Solid Earth | Year: 2016

Seismicity was monitored beneath the Krafla central volcano, NE Iceland, between 2009 and 2012 during a period of volcanic quiescence, when most earthquakes occurred within the shallow geothermal field. The highest concentration of earthquakes is located close to the rock-melt transition zone as the Iceland Deep Drilling Project-1 (IDDP-1) wellbore suggests and decays quickly at greater depths. We recorded multiple swarms of microearthquakes, which coincide often with periods of changes in geothermal field operations, and found that about one third of the total number of earthquakes are repeating events. The event size distribution, evaluated within the central caldera, indicates average crustal values with b = 0.79 ± 0.04. No significant spatial b value contrasts are resolved within the geothermal field nor in the vicinity of the drilled melt. Besides the seismicity analysis, focal mechanisms are calculated for 342 events. Most of these short-period events have source radiation patterns consistent with double-couple (DC) mechanisms. A few events are attributed to non-shear-faulting mechanisms with geothermal fluids likely playing an important role in their source processes. Diverse faulting styles are inferred from DC events, but normal faulting prevails in the central caldera. The best fitting compressional and tensional axes of DC mechanisms are interpreted in terms of the principal stress or deformation rate orientations across the plate boundary rift. Maximum compressive stress directions are near-vertically aligned in different study volumes, as expected in an extensional tectonic setting. Beneath the natural geothermal fields, the least compressive stress axis is found to align with the regional spreading direction. In the main geothermal field both horizontal stresses appear to have similar magnitudes causing a diversity of focal mechanisms. ©2016. American Geophysical Union. All Rights Reserved.


PubMed | VU University Amsterdam and Now Technologies
Type: | Journal: Drug discovery today. Technologies | Year: 2016

The blood-brain barrier (BBB) represents a major obstacle for the delivery and development of drugs curing brain pathologies. However, this biological barrier presents numerous endogenous specialized transport systems that can be exploited by engineered nanoparticles to enable drug delivery to the brain. In particular, conjugation of glutathione (GSH) onto PEGylated liposomes (G-Technology


Xia T.-Q.,Now Technologies
Signal Processing | Year: 2014

A novel joint direction of departures (DODs) and direction of arrivals (DOAs) estimator for bistatic multiple-input multiple-output (MIMO) radar via joint diagonalization direction matrices is proposed. The proposed estimator makes use of the MIMO array structure that enables to obtain an extended two-dimensional (2-D) array. Thereby, it may significantly increase the array degrees of freedom (DOFs) to estimate more targets than physical antenna elements. The computation complexity of the proposed method is also shown to be acceptable. Finally, asymptotic performance analysis and numerical experimental results are presented to demonstrate the effectiveness of the proposed method.


Xia T.-Q.,Now Technologies
Signal Processing | Year: 2015

A joint two dimensional (2D) direction of departures (DODs) and 2D direction of arrivals (DOAs) estimator for bistatic multiple input multiple output (MIMO) radar via joint diagonalization direction matrices (JDDM) is proposed. The proposed estimator makes use of the L-shaped MIMO array structure that enables to obtain an extended virtual array. Thereby, it may significantly increase the array degree of freedom and can handle targets with common one dimensional (1D) DODs and DOAs. Finally, asymptotic performance analysis and numerical experiment results are also presented to demonstrate the effectiveness of the proposed method. © 2015 Elsevier B.V. All rights reserved.


Patent
Now Technologies | Date: 2011-04-28

There is disclosed an apparatus configured to provide a chart of content items to a plurality of user devices. The apparatus is configured to enable individual users to temporarily access one or more content items listed in the chart. The apparatus comprises a user device interface configured to communicate with user device applications and a permissions module configured to define user access permissions, including temporary user access permissions, relating to individual ones of the one or more items of content. The apparatus also provides a distribution module configured to implement permissions defined in the permission module in relation to user devices by making available one or more items of content listed in the chart to at least one user device application.


Patent
Now Technologies | Date: 2013-03-28

An exhaust system includes first and second exhaust components with an inter-pipe that fluidly connects an outlet of the first exhaust component to an inlet of the second exhaust component. A passive valve is mounted within the inter-pipe. The second exhaust component defines an internal cavity that is at least partially packed with a high frequency absorption material and cooperates with the passive valve to effectively attenuate low and high frequency noise.

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