TY  - JOUR
A1  - Welden, Rene
A1  - Jablonski, Melanie
A1  - Wege, Christina
A1  - Keusgen, Michael
A1  - Wagner, Patrick Hermann
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
T1  - Light-Addressable Actuator-Sensor Platform for Monitoring and Manipulation of pH Gradients in Microfluidics: A Case Study with the Enzyme Penicillinase
JF  - Biosensors
N2  - The feasibility of light-addressed detection and manipulation of pH gradients inside an electrochemical microfluidic cell was studied. Local pH changes, induced by a light-addressable electrode (LAE), were detected using a light-addressable potentiometric sensor (LAPS) with different measurement modes representing an actuator-sensor system. Biosensor functionality was examined depending on locally induced pH gradients with the help of the model enzyme penicillinase, which had been immobilized in the microfluidic channel. The surface morphology of the LAE and enzyme-functionalized LAPS was studied by scanning electron microscopy. Furthermore, the penicillin sensitivity of the LAPS inside the microfluidic channel was determined with regard to the analyte’s pH influence on the enzymatic reaction rate. In a final experiment, the LAE-controlled pH inhibition of the enzyme activity was monitored by the LAPS.
KW  - microfluidics
KW  - enzyme kinetics
KW  - actuator-sensor system
KW  - light-addressable electrode
KW  - light-addressable potentiometric sensor
Y1  - 2021
U6  - http://dx.doi.org/10.3390/bios11060171
SN  - 2079-6374
N1  - This article belongs to the Special Issue "Selected Papers from the 1st International Electronic Conference on Biosensors (IECB 2020)"
VL  - 11
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - CHAP
A1  - Welden, Melanie
A1  - Severins, Robin
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Siegert, Petra
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Studying the immobilization of acetoin reductase with Tobacco mosaic virus particles on capacitive field-effect sensors
T2  - 2022 IEEE International Symposium on Olfaction and Electronic Nose (ISOEN)
N2  - A capacitive electrolyte-insulator-semiconductor (EISCAP) biosensor modified with Tobacco mosaic virus (TMV) particles for the detection of acetoin is presented. The enzyme acetoin reductase (AR) was immobilized on the surface of the EISCAP using TMV particles as nanoscaffolds. The study focused on the optimization of the TMV-assisted AR immobilization on the Ta 2 O 5 -gate EISCAP surface. The TMV-assisted acetoin EISCAPs were electrochemically characterized by means of leakage-current, capacitance-voltage, and constant-capacitance measurements. The TMV-modified transducer surface was studied via scanning electron microscopy.
KW  - Tobacco mosaic virus
KW  - acetoin
KW  - capacitive field-effect biosensor
KW  - enzyme immobilization
Y1  - 2022
SN  - 978-1-6654-5860-3 (Online)
SN  - 978-1-6654-5861-0 (Print)
U6  - http://dx.doi.org/10.1109/ISOEN54820.2022.9789657
N1  - IEEE International Symposium on Olfaction and Electronic Nose (ISOEN), 29 May 2022 - 01 June 2022, Aveiro, Portugal.
PB  - IEEE
ER  - 
TY  - JOUR
A1  - Welden, Melanie
A1  - Severins, Robin
A1  - Poghossian, Arshak
A1  - Wege, Christina
A1  - Bongaerts, Johannes
A1  - Siegert, Petra
A1  - Keusgen, Michael
A1  - Schöning, Michael Josef
T1  - Detection of acetoin and diacetyl by a tobacco mosaic virus-assisted field-effect biosensor
JF  - Chemosensors
N2  - Acetoin and diacetyl have a major impact on the flavor of alcoholic beverages such as wine or beer. Therefore, their measurement is important during the fermentation process. Until now, gas chromatographic techniques have typically been applied; however, these require expensive laboratory equipment and trained staff, and do not allow for online monitoring. In this work, a capacitive electrolyte–insulator–semiconductor sensor modified with tobacco mosaic virus (TMV) particles as enzyme nanocarriers for the detection of acetoin and diacetyl is presented. The enzyme acetoin reductase from Alkalihalobacillus clausii DSM 8716ᵀ is immobilized via biotin–streptavidin affinity, binding to the surface of the TMV particles. The TMV-assisted biosensor is electrochemically characterized by means of leakage–current, capacitance–voltage, and constant capacitance measurements. In this paper, the novel biosensor is studied regarding its sensitivity and long-term stability in buffer solution. Moreover, the TMV-assisted capacitive field-effect sensor is applied for the detection of diacetyl for the first time. The measurement of acetoin and diacetyl with the same sensor setup is demonstrated. Finally, the successive detection of acetoin and diacetyl in buffer and in diluted beer is studied by tuning the sensitivity of the biosensor using the pH value of the measurement solution.
Y1  - 2022
U6  - http://dx.doi.org/10.3390/chemosensors10060218
SN  - 2227-9040
N1  - This article belongs to the Special Issue "Nanostructured Devices for Biochemical Sensing"
VL  - 10
IS  - 6
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Welden, Melanie
A1  - Poghossian, Arshak
A1  - Vahidpour, Farnoosh
A1  - Wendlandt, Tim
A1  - Keusgen, Michael
A1  - Wege, Christina
A1  - Schöning, Michael Josef
T1  - Towards multi-analyte detection with field-effect capacitors modified with tobacco mosaic virus bioparticles as enzyme nanocarriers
JF  - Biosensors
N2  - Utilizing an appropriate enzyme immobilization strategy is crucial for designing enzyme-based biosensors. Plant virus-like particles represent ideal nanoscaffolds for an extremely dense and precise immobilization of enzymes, due to their regular shape, high surface-to-volume ratio and high density of surface binding sites. In the present work, tobacco mosaic virus (TMV) particles were applied for the co-immobilization of penicillinase and urease onto the gate surface of a field-effect electrolyte-insulator-semiconductor capacitor (EISCAP) with a p-Si-SiO₂-Ta₂O₅ layer structure for the sequential detection of penicillin and urea. The TMV-assisted bi-enzyme EISCAP biosensor exhibited a high urea and penicillin sensitivity of 54 and 85 mV/dec, respectively, in the concentration range of 0.1–3 mM. For comparison, the characteristics of single-enzyme EISCAP biosensors modified with TMV particles immobilized with either penicillinase or urease were also investigated. The surface morphology of the TMV-modified Ta₂O₅-gate was analyzed by scanning electron microscopy. Additionally, the bi-enzyme EISCAP was applied to mimic an XOR (Exclusive OR) enzyme logic gate.
KW  - urease
KW  - enzyme-logic gate
KW  - bi-enzyme biosensor
KW  - capacitive field-effect sensor
KW  - tobacco mosaic virus (TMV)
KW  - penicillinase
Y1  - 2022
U6  - http://dx.doi.org/10.3390/bios12010043
SN  - 2079-6374
N1  - This article belongs to the Special Issue "Biosensors: 10th Anniversary Feature Papers"
VL  - 12
IS  - 1
PB  - MDPI
CY  - Basel
ER  - 
TY  - BOOK
A1  - Weißmantel, Ralf
T1  - Plakatzeichen : Plakate mit Schrift über Schrift ; 50 typografische Plakate ; Kommunikationsdesign
Y1  - 2013
SN  - 978-3-00041325-4
PB  - Fachhochschule Aachen, Fachbereich Design
CY  - Aachen
ER  - 
TY  - CHAP
A1  - Weiss, Christian
A1  - Heslenfeld, Jonas
A1  - Saewe, Jasmin Kathrin
A1  - Bremen, Sebastian
A1  - Häfner, Constantin Leon
T1  - Investigation on the influence of powder humidity in Laser Powder Bed Fusion (LPBF)
T2  - Procedia CIRP
N2  - In the Laser Powder Bed Fusion (LPBF) process, parts are built out of metal powder material by exposure of a laser beam. During handling operations of the powder material, several influencing factors can affect the properties of the powder material and therefore directly influence the processability during manufacturing. Contamination by moisture due to handling operations is one of the most critical aspects of powder quality. In order to investigate the influences of powder humidity on LPBF processing, four materials (AlSi10Mg, Ti6Al4V, 316L and IN718) are chosen for this study. The powder material is artificially humidified, subsequently characterized, manufactured into cubic samples in a miniaturized process chamber and analyzed for their relative density. The results indicate that the processability and reproducibility of parts made of AlSi10Mg and Ti6Al4V are susceptible to humidity, while IN718 and 316L are barely influenced.
KW  - LPBF
KW  - Additive Manufacturing
KW  - Powder Material
KW  - Humidity
Y1  - 2022
U6  - http://dx.doi.org/10.1016/j.procir.2022.08.102
SN  - 2212-8271
N1  - Teil der Sonderausgabe: 12th CIRP Conference on Photonic Technologies [LANE 2022]
VL  - 111
SP  - 115
EP  - 120
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Weiss, Alexander
A1  - Abanteriba, Sylvester
A1  - Esch, Thomas
T1  - Investigation of Flow Separation Inside a Conical Rocket Nozzle With the Aid of an Annular Cross Flow
T2  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B
N2  - Flow separation is a phenomenon that occurs in all kinds of supersonic nozzles sometimes during run-up and shut-down operations. Especially in expansion nozzles of rocket engines with large area ratio, flow separation can trigger strong side loads that can damage the structure of the nozzle. The investigation presented in this paper seeks to establish measures that may be applied to alter the point of flow separation. In order to achieve this, a supersonic nozzle was placed at the exit plane of the conical nozzle. This resulted in the generation of cross flow surrounding the core jet flow from the conical nozzle. Due to the entrainment of the gas stream from the conical nozzle the pressure in its exit plane was found to be lower than that of the ambient. A Cold gas instead of hot combustion gases was used as the working fluid. A mathematical simulation of the concept was validated by experiment. Measurements confirmed the simulation results that due to the introduction of a second nozzle the pressure in the separated region of the conical nozzle was significantly reduced. It was also established that the boundary layer separation inside the conical nozzle was delayed thus allowing an increased degree of overexpansion. The condition established by the pressure measurements was also demonstrated qualitatively using transparent nozzle configurations.
Y1  - 2007
SN  - 0-7918-4288-6
U6  - http://dx.doi.org/10.1115/FEDSM2007-37387
N1  - Proceedings of the ASME/JSME 2007 5th Joint Fluids Engineering Conference. Volume 1: Symposia, Parts A and B. San Diego, California, USA. July 30–August 2, 2007
SP  - 1861
EP  - 1871
PB  - American Society of Mechanical Engineers (ASME)
CY  - New York
ER  - 
TY  - RPRT
A1  - Weis, Fabian
A1  - Schorn, Christian
A1  - Anthrakidis, Anette
A1  - Herrmann, Ulf
T1  - Entwicklung eines kleinen Parabolrinnenkollektors mit Kunststoffkorpus zur Bereitstellung solarer Prozesswärme : Poly-P : Abschlussbericht
Y1  - 2016
PB  - Solar-Institut Jülich
CY  - Jülich
ER  - 
TY  - CHAP
A1  - Weingart, Daniel
A1  - Schneider, Ulf
A1  - Wollert, Jörg
T1  - Doppelt gekoppelt - Kabellose und dynamische Anbindung von CANopen an Profinet IO
T2  - Elektrische Automatisierung - Systeme und Komponenten: SPS-IPC-Drives 2009, Fachmesse & Kongress, 24. - 26. Nov. 2009, Nürnberg ; [Tagungsband]
Y1  - 2009
SN  - 978-3-8007-3184-8
SP  - 147
EP  - 154
PB  - VDE-Verl.
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Weil, M.
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Cherstvy, A.
T1  - Electrical monitoring of layer-by-layer adsorption of oppositely charged macromolecules by means of capacitive field-effect devices
Y1  - 2012
SN  - 978-3-9813484-2-2
U6  - http://dx.doi.org/10.5162/IMCS2012/P2.5.2
SP  - 1575
EP  - 1578
ER  - 
TY  - JOUR
A1  - Weihe, Stefan
A1  - Ernst, Ansgar
A1  - Röth, Thilo
A1  - Proksch, Johannes
T1  - Aluminium-Stahl-Verbundguss im Nutzfahrzeugbau
JF  - ATZ - Automobiltechnische Zeitschrift
N2  - In modernen Fahrzeugkarosserien der Großserie kommen zunehmend Materialmischbauweisen zur Anwendung. In Zusammenarbeit der Daimler AG, der Tower Automotive Holding GmbH, der Imperia GmbH sowie der Partnerunternehmen KSM Castings GmbH und Schaufler Tooling GmbH & Co. KG wird das Leichtbaupotenzial von Aluminiumverbundguss-Stahlblech-Hybriden am Beispiel des vorderen Dachquerträgers des Mercedes-Benz Viano/Vito ausführlich untersucht.
Y1  - 2013
SN  - 2192-8800 (Online)
SN  - 0001-2785 (Print)
VL  - 115
IS  - 4
SP  - 312
EP  - 316
PB  - Springer Fachmedien Wiesbaden
ER  - 
TY  - JOUR
A1  - Weihe, Stefan
A1  - Ansgar, Ernst
A1  - Röth, Thilo
A1  - Proksch, Johannes
T1  - Leichtmetall-Stahl-Verbundguss im Nutzfahrzeugbau
JF  - Lightweight Design
N2  - In modernen Fahrzeugkarosserien der Großserie kommen zunehmend Materialmischbauweisen
zur Anwendung. In Zusammenarbeit der Daimler AG, der Tower Automotive Holding
GmbH, der Imperia GmbH sowie der Partnerunternehmen KSM Castings GmbH und Schaufler
Tooling GmbH & Co. KG wird das Leichtbaupotenzial von Stahlblech-AluminiumverbundgussHybriden
am Beispiel des vorderen Dachquerträgers des Mercedes-Benz Viano/Vito ausführlich
untersucht.
Y1  - 2013
SN  - 2192-8738 (Online)
SN  - 1865-4819 (Print)
VL  - 6
IS  - 2
SP  - 38
EP  - 43
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
A1  - Collani, E. v.
A1  - Saniga, E.M.
T1  - Economic Adjustment Design for -Control Charts. E.v.Collani, E.M. Saniga, Ch. Weigand
JF  - IIE Transactions / Institute of Industrial Engineers. 26 (1994), H. 6
Y1  - 1994
SN  - 0569-5554
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - Optimal Production Schedule for a K Products Single Machine Problem
JF  - Economic Quality Control. 9 (1994)
Y1  - 1994
SN  - 0940-5151
SP  - 91
EP  - 101
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - Optimale Maschinenjustierung
JF  - Technische Hochschule <Ilmenau> / Bibliothek: Wissenschaftliche Zeitschrift. 37 (1991)
Y1  - 1991
SN  - 0043-6917
SP  - 167
EP  - 175
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - A Solution to the Scheduling Problem Taking into Account Quality
JF  - Operations research '91 : extended abstracts of the 16th Symposium on Operations Research held at the University of Trier at September 9 - 11, 1991 / [GMÖOR]. Peter Gritzmann ... (eds.)
Y1  - 1991
SN  - 3790806080
N1  - Symposium on Operations Research ; (16, 1991, Trier)
SP  - 373
EP  - 375
PB  - Physica-Verl.
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - Optimal Adjustment Policies
JF  - Proceedings of the First Umeå-Würzburg Conference in Statistics : Kronlund Conference Center and University of Umeå, September 10 - 14, 1990 / ed. by Kurt Brännäs
Y1  - 1990
SN  - 91-7174-564-5
N1  - Umeå-Würzburg Conference in Statistics <1, 1990>
SP  - 147
EP  - 158
PB  - Univ. of Umeå
CY  - Umeå
ER  - 
TY  - BOOK
A1  - Weigand, Christoph
T1  - Statistik mit und ohne Zufall : eine anwendungsorientierte Einführung ; mit 10 Tabellen / Christoph Weigand
Y1  - 2006
SN  - 3-7908-1693-0
N1  - [Neuere Aufl. vorh.] https://doi.org/10.1007/978-3-662-59309-7
PB  - Physica-Verl.
CY  - Heidelberg
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - Technically Optimal Inspection Policy with Arithmetical Adaption
JF  - IMA Journal of Management Mathematics. 14 (2003), H. 4
Y1  - 2003
SN  - 1471-678X
N1  - weitere ISSN 1471-6798 (E)
SP  - 357
EP  - 371
ER  - 
TY  - JOUR
A1  - Weigand, Christoph
T1  - Economically Optimal Inspection Policy with Geometrical Adaption
JF  - Journal of Applied Statistics. 30 (2003), H. 5
Y1  - 2003
SN  - 0266-4763
N1  - weitere ISSN 1360-0532 (E)
SP  - 555
EP  - 569
ER  -