TY  - GEN
A1  - Lemke, Matthias
A1  - Fernández-Trujillo, Rebeca
A1  - Löhmannsröben, Hans-Gerd
T1  - In-situ LIF analysis of biological and petroleum-based hydraulic oils on soil
N2  - Absorption and fluorescence properties of 4 hydraulic oils (3 biological and 1 petroleum-based) were investigated. In-situ LIF (laser-induced fluorescence) analysis of the oils on a brown sandy loam soil was performed. With calibration, quantitative detection was achieved. Estimated limits of detection were below ca. 500 mg/kg for the petroleum-based oil and ca. 2000 mg/kg for one biological oil. A semi-quantitative classification scheme is proposed for monitoring of the biological oils. This approach was applied to investigate the migration of a biological oil in soil-containing compartments, namely a soil column and a soil bed.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 011 
KW  - in-situ
KW  - optical oil sensor
KW  - lubricants
KW  - hydraulic oils
KW  - soil
KW  - laser induced
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12268
ER  - 
TY  - GEN
A1  - Löhmannsröben, Hans-Gerd
A1  - Kantor, Zoltan
A1  - Kumke, Michael Uwe
A1  - Schmälzlin, Elmar
A1  - Reich, Oliver
T1  - OPQS – optische Prozess- und Qualitäts-Sensorik
N2  - Im vorliegenden Beitrag wird an Hand dreier Beispiele der Einsatz von optischer Sensorik zur Produktcharakterisierung dargestellt, nämlich Untersuchungen zum O2-Gehalt in Fruchtsäften, zur Isotopiesignatur von CO2 in Mineralwässern und zu Lichtstreueigenschaften eines Sonnenschutzmittels. Inhalt: Bestimmung von O2 mit Lumineszenzsonden Isotopenselektive Bestimmung von CO2 mit TDLAS Optische Charakterisierung stark streuender Materialien mit Photonendichtewellen
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 028 
KW  - Sensorik
KW  - Prozesskontrolle
KW  - Absorption
KW  - Lumineszenz
KW  - Lichtstreuung
KW  - Isotopie
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-13205
ER  - 
TY  - GEN
A1  - Schmälzlin, Elmar
A1  - Dongen, Joost T. van
A1  - Klimant, Ingo
A1  - Marmodée, Bettina
A1  - Steup, Martin
A1  - Fishahn, Joachim
A1  - Geigenberger, Peter
A1  - Löhmannsröben, Hans-Gerd
T1  - An optical multifrequency phase-modulation method using microbeads for measuring intracellular oxygen concentrations in plants
N2  - A technique has been developed to measure absolute intracellular oxygen concentrations in green plants. Oxygen-sensitive phosphorescent microbeads were injected into the cells and an optical multifrequency phase-modulation technique was used to discriminate the sensor signal from the strong autofluorescence of the plant tissue. The method was established using photosynthesis-competent cells of the giant algae Chara corallina L., and was validated by application to various cell types of other plant species.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 007 
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12232
ER  - 
TY  - GEN
A1  - Schuler, Benjamin
A1  - Lipman, Everett A.
A1  - Steinbach, Peter J.
A1  - Kumke, Michael Uwe
A1  - Eaton, William A.
T1  - Polyproline and the "spectroscopic ruler" revisited with single-molecule fluorescence
N2  - To determine whether Förster resonance energy transfer (FRET) measurements can provide quantitative distance information in single-molecule fluorescence experiments on polypeptides, we measured FRET efficiency distributions for donor and acceptor dyes attached to the ends of freely diffusing polyproline molecules of various lengths. The observed mean FRET efficiencies agree with those determined from ensemble lifetime measurements but differ considerably from the values expected from Förster theory, with polyproline treated as a rigid rod. At donor–acceptor distances much less than the Förster radius R0, the observed efficiencies are lower than predicted, whereas at distances comparable to and greater than R0, they are much higher. Two possible contributions to the former are incomplete orientational averaging during the donor lifetime and, because of the large size of the dyes, breakdown of the point-dipole approximation assumed in Förster theory. End-to-end distance distributions and correlation times obtained from Langevin molecular dynamics simulations suggest that the differences for the longer polyproline peptides can be explained by chain bending, which considerably shortens the donor–acceptor distances.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 008 
KW  - Förster resonance energy transfer
KW  - molecular dynamics
KW  - polypeptide
KW  - FRET
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-12229
ER  -