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Suche nach „[2018]“ hat 104 Publikationen gefunden
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    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTC Weißenburg

    Zeitschriftenartikel

    Damigos, Y., Kourousis, D., Frankenstein, B., Gerhard, R., Amditis, A., Cheilakou, E., Dmitry Rychkov, Bouklas, C., Tsopelas, N., Anastasopoulos, A.

    Strain monitoring system for steel and concrete structures

    Procedia Structural Integrity, vol. 10, pp. 25-32

    2018

    DOI: 10.1016/j.prostr.2018.09.005

    Abstract anzeigen

    The present work is part of a collaborative H2020 European funded research project called SENSKIN, that aims to improve Structural Health Monitoring (SHM) for transport infrastructure through the development of an innovative monitoring and management system for bridges based on a novel, inexpensive, skin-like sensor. The integrated SENSKIN technology will be implemented in the case of steel and concrete bridges, and tested, field-evaluated and benchmarked on actual bridge environment against a conventional health monitoring solution developed by Mistras Group Hellas. The main objective of the present work is to implement the autonomous, fully functional strain monitoring system based on commercially available off-the-shelf components, that will be used to accomplish direct comparison between the performance of the innovative SENSKIN sensors and the conventional strain sensors commonly used for structural monitoring of bridges. For this purpose, the mini Structural Monitoring System (mini SMS) of Physical Acoustics Corporation, a comprehensive data acquisition unit designed specifically for long-term unattended operation in outdoor environments, was selected. For the completion of the conventional system, appropriate foil-type strain sensors were selected, driven by special conditioners manufactured by Mistras Group. A comprehensive description of the strain monitoring system and its peripheral components is provided in this paper. For the evaluation of the integrated system’s performance and the effect of various parameters on the long-term behavior of sensors, several test steel pieces instrumented with different strain sensors configurations were prepared and tested in both laboratory and field ambient conditions. Furthermore, loading tests were performed aiming to validate the response of the system in monitoring the strains developed in steel beam elements subject to bending regimes. Representative results obtained from the above experimental tests have been included in this paper as well.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTC Weißenburg

    Zeitschriftenartikel

    Dmitry Rychkov, Altafim, R.A.P.

    Template-based fluoroethylenepropylene ferroelectrets with enhanced thermal stability of piezoelectricity

    Journal of Applied Physics, vol. 124, no. 17

    2018

    DOI: 10.1063/1.5041374

    Abstract anzeigen

    In ferroelectrets, the piezoelectricity stems from the charges of both polarities trapped on the inner surfaces of the cavities in the material, so that its thermal stability is defined by the stability of the respective charges. In the present work, a template-based lamination technique has been employed to fabricate tubular-channel ferroelectrets from fluoroethylenepropylene (FEP) films. It has been shown that the piezoelectricity in FEP ferroelectrets decays at relatively low temperatures due to the inherently lower thermal stability of the positive charge. In order to improve charge trapping, we have treated both FEP films and inner surfaces of the ferroelectret cavities with titanium-tetrachloride vapor, using the atomic-layer-deposition technique. Using surface-potential-decay measurements on FEP films, we have found that the charge-decay curves shift by more than 100 ∘C to the higher temperatures as a result of the surface treatment. Direct measurements of piezoelectric d33 coefficients as a function of temperature have shown that the piezoelectric stability is likewise improved with the d33-decay curves shifted by 60 ∘C to the right. The improvement of electret/ferroelectret properties can be attributed to the formation of the deeper traps on the chemically modified FEP surface. SEM micrographs and EDS analysis reveal island-like structures with titanium- and oxygen-containing species that can be responsible for the deeper trapping of the electret charges.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenTC Weißenburg

    Zeitschriftenartikel

    Gerhard, R., Kuznetsov, A., Dmitry Rychkov, Rychkov, A. A.

    Influence of Charge Density on the Trap-Energy Spectrum in Fluoroethylenepropylene Copolymer Films with Chemically Modified Surfaces

    IEEE Transactions on Dielectrics and Electrical Insulation, vol. 25, no. 3, pp. 840-844

    2018

    DOI: 10.1109/TDEI.2018.007437

    Abstract anzeigen

    Tetrafluoroethylene-hexafluoropropylene copolymer (FEP) films were treated with titanium-tetrachloride vapor by means of molecular-layer deposition. The treatment leads to considerable improvements of the electret-charge stability on positively charged films. A slight improvement is also observed for negatively charged films. In line with our previous findings, we attribute the improvement in electret properties to the formation of deeper traps on the chemically modified polymer surfaces. Here, we investigate the influence of the charge density on electret stability of FEP films with modified surfaces. Trap-energy spectra obtained from thermally-stimulated-discharge measurements indicate that the charge stability on modified FEP films depends on how the surface traps are populated and on the availability of additional deeper traps.

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Actuation of fuel injectors for multiple injections

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    [DE] Bestimmung des elektrischen Widerstands eines Kraftstoffinjektors mit Magnetspulenantrieb [EN] Determining the electrical resistance of a fuel injector having a solenoid drive [FR] Détermination ...

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, G. Rösel, Frank Denk

    Method for operating a fuel injector with an idle stroke

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Determination of a point in time of a predetermined open state of a fuel injector

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Verfahren zum Betreiben einer Magnetaktoranordnung

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Precise determinatin of the electrical resistance of fuel injector having solenoid drive

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Precise determination of the electrical resistance of a fuel injector having a solenoid drive

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Method for determining a reference current value for actuating a fuel injector

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Method For Determining A Reference Current Value For Actuating A Fuel Injector

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Actuation of fuel injectors for multiple injections

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Device and method for controlling an injection valve

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Determination of the point in time of a predetermined open state of a fuel injector

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Method and device for determining a reference current progression for a fuel injector, for determining the instant of a predetermined opening state of the fuel injector

    2018

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    Patent

    Continental Automotive GmbH, Frank Denk, U. Wagner

    Verfahren zur Ermittlung des in einem Kraftstoffeinspritzventil herrschenden Kraftstoffdruckes

    2018

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    Patent

    Continental Automotive GmbH, Frank Denk

    Verfahren zum Erkennen einer Veränderung eines zumindest einen Teil eines Gesamtluftspaltes bildenden Arbeitsweges eines Magnetankers eines Kraftstoffeinspritzventils

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Verfahren zum Erkennen einer Veränderung eines zumindest einen Teil eines Gesamtluftspaltes bildenden Arbeitsweges eines Magnetankers eines Kraftstoffeinspritzventils

    2018

    TC Cham

    Patent

    Continental Automotive GmbH, Frank Denk

    Verfahren zum Erkennen der Vorspannung einer Kalibrationsfeder eines magnetisch betriebenen Kraftstoffeinspritzventils

    2018