Publications Search Results

Now showing 1 - 10 of 98
  • Publication
    Polymer metal oxide composite layers for optical functional coatings
    ( 2010)
    Neubert, T.
    ;
    Drost, S.
    ;
    Nagel, K.
    ;
    Vergöhl, M.
    The objective of this work was to prove the suitability of metal oxide polymer composite layers for optical functional coatings. Because of their flexibility such layers could better meet the mechanical requirements of flexible substrates such as plastic foils than conventional dielectric coatings. Furthermore, with organic film components it should be possible to integrate specific layer properties like hydrophobicity or other functionalities. Thin composite layers of ditantalum pentoxide (Ta2O5) and polytetrafluoroethylene (PTFE) were made by a co-sputter deposition process. The Ta2O5 films were coated with reactive DC magnetron sputtering in an Ar/O2 atmosphere. For the PTFE films a PTFE target with RF power input was used. The influence of process parameters (power, gas atmosphere) on the optical and mechanical layer properties (transmittance in the visible range, dispersion, infra red absorption, adhesion, crack onset strain) was investigated. In addition different optical layer systems based on conventional material combinations and on polymer composites were compared.
  • Publication
    Organische Schichten für optische Interferenzschichtsysteme
    ( 2010)
    Neubert, T.
    ;
    Drost, S.
    ;
    Vergöhl, M.
  • Patent
    Vorrichtung zur Vervielfaeltigung und Detektion von Nukleinsaeuren
    ( 2007)
    Drost, S.
    ;
    Strohhoefer, C.
    ;
    Meixner, L.
    Es wird eine Vorrichtung zur Vervielfaeltigung und Detektion von Targetsubstanzen, insbesondere von Nukleinsaeuren, aus einer Probe beschrieben. Die Vorrichtung umfasst mindestens zwei Vervielfaeltigungsmodule sowie mindestens zwei Detektionsmodule, die auf einem Bauteil angeordnet sind, wobei die Vervielfaeltigungsmodule ueber eine jeweils individuell anzusteuernde Temperierungseinheit temperierbar sind.
  • Patent
    Vorrichtung zum Erfassen einer Belagsaenderung, Vorrichtung zum Erfassen eines Reinigungsfortschritts in einer zu reinigenden Anlage und Verfahren zum Steuern eines Reinigungsvorgangs von Belaegen auf einem Arbeitsteil
    ( 2004)
    Endres, H.
    ;
    Hammerl, E.
    ;
    Drost, S.
    ;
    Menner, M.
    ;
    Pfeiffer, T.
    Eine Vorrichtung zum Erfassen einer Belagsaenderung umfasst einen Interdigital-Kondensator mit einer Aussenflaeche, auf der ein Belag abscheidbar ist, so dass eine Impedanz des Interdigital-Kondensators von dem abgeschiedenen Belag abhaengt. Eine Impedanzerfassungsvorrichtung erfasst Impedanzwerte des Interdigital-Kondensators, wobei die erfassten Impedanzwerte in einer Auswerteeinrichtung verwendet werden, um eine Indikatorgroesse zu berechnen, die auf eine zeitliche Aenderung des Belags hinweist.
  • Publication
    Polymer BioMEMs with integrated optical and fluidic functionality
    ( 2003)
    Windhorn, K.
    ;
    Meixner, L.
    ;
    Drost, S.
    ;
    Schröder, H.
    ;
    Kilgus, E.
    ;
    Scheel, W.
    ;
    Ebling, F.
    ;
    Otto, T.
    ;
    Küchler, M.
    ;
    Nestler, J.
    ;
    Geßner, T.
  • Publication
    A technology for a device prototyping based on electrodeposited thermoelectric V-VI layers
    ( 2003)
    Diliberto, S.
    ;
    Michel, S.
    ;
    Boulanger, C.
    ;
    Lecuire, J.M.
    ;
    Jägle, M.
    ;
    Drost, S.
    ;
    Böttner, H.
  • Publication
    Monitoring of cleaning processes with an impedimetric sensor
    ( 2003)
    Endres, H.-E.
    ;
    Hammerl, E.
    ;
    Drost, S.
    ;
    Menner, M.
    ;
    Pfeiffer, T.
    Fouling layers on hot surfaces in food processing lines have frequently to be cleaned. Up to now, an inline monitoring of the cleaning process does not exist. Therefore, the cleaning is based on empirical knowledge and occasional optical inspections. The article presents a planar capacitive sensor together with an impedance spectroscopic measurement method and a multivariate signal evaluation to monitor the cleaning process. The result of the signal evaluation is a numerical cleaning indicator, which shows the progress of the cleaning. A steady state of the cleaning indicator signals the end of the cleaning proc-ess. First results, obtained in a laboratory model of a heat exchanger, were presented. A reduction of the cleaning time in industrial plants up to 50 % is expected.
  • Publication
    Sensor system to determine the supersaturation in industrial batch processes
    ( 2003)
    Endres, H.-E.
    ;
    Neumeier, K.
    ;
    Hammerl, E.
    ;
    Drost, S.
    ;
    Müller, R.
    ;
    Löffelmann, M.
    ;
    Mersmann, A.
    The supersaturation is an essential parameter to control industrial batch crysta llization processes. Until now a quantitative online measurement of supersaturat ion was not possible. A new sensor system consist-ing of an interdigitated capac itor (IDC) and a surface acoustic wave transducer is mounted on top of a peltier element, which allows a thermal cycling around the crystallization temperature. Together with a multivariate signal evaluation the online measurement of the su persaturation could be demonstrated.
  • Publication
    A new method for filter-free fluorescence measurements
    ( 2002)
    Langer, P.
    ;
    Muller, R.
    ;
    Drost, S.
    ;
    Werner, T.
    Fluorescence measurements usually evaluate the intensity and the decay- time of the fluorophore. For the suppression of the excitation light at the optical receiver optical filters are generally used. In this paper, a technique is described which provides the suppression of the excitation light component by electronic means, thus, eliminating the need for an optical filter. An intensity-modulated excitation light causes an intensity-modulated fluorescence signal. This fluorescence signal is mixed with a signal having a 90 degrees phase shift with respect to the excitation light. The product of two orthogonal signals equals zero and in this way the excitation light is suppressed. Measurements at two or more modulation frequencies make it possible to compute the relative intensity and the decay-time. The advantage of this technique is its flexibility in the adaptation to different fluorescent materials and its compact realization. This method was evaluated for Lucigenin quenched by chloride ions using an experimental set-up consisting of a LED, a photo multiplier, no optical filters and either a network analyzer (NWA) or a self-made electronic circuit. Although up to 10 times more primary light than fluorescence light was detected at the optical receiver, the omission of the optical filter did not contribute to undesired effects. The results were compared with measurements on the same samples using a conventional test set-up. There was no difference in the computed Stern-Volmer constant. Therefore, the new method offers a cost-effective but still exact alternative for measuring fluorescence intensity and decay-time down to the range of nano-seconds.
  • Publication
    HSG-FET - A novel hydrogen sensor
    ( 2002)
    Endres, H.-E.
    ;
    Neumeier, K.
    ;
    Drost, S.