TY  - JOUR
A1  - Murib, Mohammed S.
A1  - Tran, Anh Quang
A1  - Ceuninck, Ward de
A1  - Schöning, Michael Josef
A1  - Nesladek, Milos
A1  - Serpengüzel, Ali
A1  - Wagner, Patrick
T1  - Analysis of an optical biosensor based on elastic light scattering from diamond-, glass-, and sapphire microspheres
JF  - Physica Status Solidi A
N2  - Deoxyribonucleic acid (DNA) and protein recognition are now standard tools in biology. In addition, the special optical properties of microsphere resonators expressed by the high quality factor (Q-factor) of whispering gallery modes (WGMs) or morphology dependent resonances (MDRs) have attracted the attention of the biophotonic community. Microsphere-based biosensors are considered as powerful candidates to achieve label-free recognition of single molecules due to the high sensitivity of their WGMs. When the microsphere surface is modified with biomolecules, the effective refractive index and the effective size of the microsphere change resulting in a resonant wavelength shift. The transverse electric (TE) and the transverse magnetic (TM) elastic light scattering intensity of electromagnetic waves at 600 and 1400 nm are numerically calculated for DNA and unspecific binding of proteins to the microsphere surface. The effect of changing the optical properties was studied for diamond (refractive index 2.34), glass (refractive index 1.50), and sapphire (refractive index 1.75) microspheres with a 50 µm radius. The mode spacing, the linewidth of WGMs, and the shift of resonant wavelength due to the change in radius and refractive index, were analyzed by numerical simulations. Preliminary results of unspecific binding of biomolecules are presented. The calculated shift in WGMs can be used for biomolecules detection.
Y1  - 2012
U6  - https://doi.org/10.1002/pssa.201100795
SN  - 1862-6319
N1  - Special Issue: "Fundamentals and Applications of Diamond"
VL  - 209
IS  - 9
SP  - 1804
EP  - 1810
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Yeap, W. S.
A1  - Martens, D.
A1  - Liu, X.
A1  - Bienstman, P.
A1  - Fahlman, M.
A1  - Schöning, Michael Josef
A1  - Michiels, L.
A1  - Haenen, K.
A1  - Serpengüzel, A.
A1  - Wagner, Patrick
T1  - Photonic studies on polymer-coated sapphire-spheres : a model system for biological ligands
JF  - Sensors and actuators A: Physical
N2  - In this study we show an optical biosensor concept, based on elastic light scattering from sapphire microspheres. Transmitted and elastic scattering intensity of the microspheres (radius 500 μm, refractive index 1.77) on an optical fiber half coupler is analyzed at 1510 nm. The 0.43 nm angular mode spacing of the resonances is comparable to the angular mode spacing value estimated using the optical size of the microsphere. The spectral linewidths of the resonances are in the order of 0.01 nm, which corresponds to quality factors of approximately 105. A polydopamine layer is used as a functionalizing agent on sapphire microspherical resonators in view of biosensor implementation. The varying layer thickness on the microsphere is determined as a function of the resonance wavelength shift. It is shown that polymer functionalization has a minor effect on the quality factor. This is a promising step toward the development of an optical biosensor.
Y1  - 2015
U6  - https://doi.org/10.1016/j.sna.2014.11.024
SN  - 1873-3069 (E-Journal); 0924-4247 (Print)
VL  - 222
SP  - 212
EP  - 219
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Yeap, W. S.
A1  - Eurlings, Y.
A1  - Grinsven, B. van
A1  - Boyen, H.-G.
A1  - Conings, B.
A1  - Michiels, L.
A1  - Ameloot, Marcel
A1  - Carleer, R.
A1  - Warmer, J.
A1  - Kaul, P.
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Ceuninck, W. de
A1  - Wagner, P.
T1  - Heat-transfer based characterization of DNA on synthetic sapphire chips
JF  - Sensors and Actuators B: Chemical
N2  - In this study, we show that synthetic sapphire (Al₂O₃), an established implant material, can also serve as a platform material for biosensors comparable to nanocrystalline diamond. Sapphire chips, beads, and powder were first modified with (3-aminopropyl) triethoxysilane (APTES), followed by succinic anhydride (SA), and finally single-stranded probe DNA was EDC coupled to the functionalized layer. The presence of the APTES-SA layer on sapphire powders was confirmed by thermogravimetric analyis and Fourier-transform infrared spectroscopy. Using planar sapphire chips as substrates and X-ray photoelectron spectroscopy (XPS) as surface-sensitive tool, the sequence of individual layers was analyzed with respect to their chemical state, enabling the quantification of areal densities of the involved molecular units. Fluorescence microscopy was used to demonstrate the hybridization of fluorescently tagged target DNA to the probe DNA, including denaturation- and re-hybridization experiments. Due to its high thermal conductivity, synthetic sapphire is especially suitable as a chip material for the heat-transfer method, which was employed to distinguish complementary- and non-complementary DNA duplexes containing single-nucleotide polymorphisms. These results indicate that it is possible to detect mutations electronically with a chemically resilient and electrically insulating chip material.
Y1  - 2016
U6  - https://doi.org/10.1016/j.snb.2016.02.027
SN  - 0925-4005
VL  - 230
IS  - 230
SP  - 260
EP  - 271
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Murib, M. S.
A1  - Grinsven, B. van
A1  - Grieten, L.
A1  - Janssens, S. D.
A1  - Vermeeren, V.
A1  - Eersels, K.
A1  - Broeders, J.
A1  - Ameloot, Marcel
A1  - Michiels, L.
A1  - Ceuninck, W. De
A1  - Haenen, K.
A1  - Schöning, Michael Josef
A1  - Wagner, Patrick
T1  - Electronic monitoring of chemical DNA denaturation on nanocrystalline diamond electrodes with different molarities and flow rates
JF  - Physica Status Solidi (A). Vol. 210 (2013), iss. 5
Y1  - 2013
SN  - 0031-8965
SP  - 911
EP  - 917
PB  - Wiley-VCH
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Mulsow, Niklas A.
A1  - Hülsen, Benjamin
A1  - Gützlaff, Joel
A1  - Spies, Leon
A1  - Bresser, Andreas
A1  - Dabrowski, Adam
A1  - Czupalla, Markus
A1  - Kirchner, Frank
T1  - Concept and design of an autonomous micro rover for long term lunar exploration
T2  - Proceedings of the 74th International Astronautical Congress
N2  - Research on robotic lunar exploration has seen a broad revival, especially since the Google Lunar X-Prize increasingly brought private endeavors into play. This development is supported by national agencies with the aim of enabling long-term lunar infrastructure for in-situ operations and the establishment of a moon village. One challenge for effective exploration missions is developing a compact and lightweight robotic rover to reduce launch costs and open the possibility for secondary payload options. Existing micro rovers for exploration missions are clearly limited by their design for one day of sunlight and their low level of autonomy. For expanding the potential mission applications and range of use, an extension of lifetime could be reached by surviving the lunar night and providing a higher level of autonomy. To address this objective, the paper presents a system design concept for a lightweight micro rover with long-term mission duration capabilities, derived from a multi-day lunar mission scenario at equatorial regions. Technical solution approaches are described, analyzed, and evaluated, with emphasis put on the harmonization of hardware selection due to a strictly limited budget in dimensions and power.
Y1  - 2023
N1  - 74. International Astronautical Congress (IAC-2023), October 2-6 2023, Baku, Azerbaijan
PB  - dfki
CY  - Saarbrücken
ER  - 
TY  - JOUR
A1  - Mulhern, Colm
A1  - Bialonski, Stephan
A1  - Kantz, Holger
T1  - Extreme events due to localization of energy
JF  - Physical Review E
Y1  - 2015
U6  - https://doi.org/10.1103/PhysRevE.91.012918
SN  - 2470-0053
VL  - 91
IS  - 1
SP  - 012918
ER  - 
TY  - JOUR
A1  - Mukherjee, Krishnendu
A1  - Ramazani, Ali
A1  - Yang, Li
A1  - Prahl, Ulrich
A1  - Bleck, Wolfgang
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
T1  - Characterization of gas metal arc welded hot rolled DP600 steel
JF  - Steel research international
Y1  - 2011
SN  - 1869-344X (E-Book); 1611-3683 (Print)
VL  - Vol. 82
IS  - Iss. 12
SP  - 1408
EP  - 1416
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Mukherjee, Krishnendu
A1  - Prahl, Ulrich
A1  - Bleck, Wolfgang
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
T1  - Characterization and modelling techniques for gas metal arc welding of DP 600 sheet steels
JF  - Materialwissenschaft und Werkstofftechnik
N2  - The objectives of the present work are to characterize the Gas Metal Arc Welding process of DP 600 sheet steel and to summarize the modelling techniques. The time-temperature evolution during the welding cycle was measured experimentally and modelled with the softwaretool SimWeld. To model the phase transformations during the welding cycle dilatometer tests were done to quantify the parameters for phase field modelling by MICRESS®. The important input parameters are interface mobility, nucleation density, etc. A contribution was made to include austenite to bainite transformation in MICRESS®. This is useful to predict the microstructure in the fast cooling segments. The phase transformation model is capable to predict the microstructure along the heating and cooling cycles of welding. Tensile tests have shown the evidence of failure at the heat affected zone, which has the ferrite-tempered martensite microstructure.
Y1  - 2010
U6  - https://doi.org/10.1002/mawe.201000692
SN  - 1521-4052
VL  - 41
IS  - 11
SP  - 972
EP  - 983
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - CHAP
A1  - Muffler, Kai
A1  - Tippkötter, Nils
A1  - Ulber, Roland
ED  - Timmis, Kenneth N.
T1  - Chemical feedstocks and fine chemicals from other substrates
T2  - Handbook of hydrocarbon and lipid microbiology. Volume 4:  Consequences of microbial interactions with hydrocarbons, oils and lipids. - (Springer reference)
Y1  - 2010
SN  - 978-3-540-77588-1
U6  - https://doi.org/10.1007%2F978-3-540-77587-4_214
SP  - 2891
EP  - 2902
PB  - Springer
CY  - Berlin [u.a.]
ER  - 
TY  - CHAP
A1  - Muffler, Kai
A1  - Poth, Sabastian
A1  - Sieker, Tim
A1  - Tippkötter, Nils
A1  - Ulber, Roland
A1  - Sell, Dieter
ED  - Moo-Young, Murray
T1  - Bio-feedstocks
T2  - Comprehensive biotechnology : principles and practices in industry, agcriculture, medicine and the environment. Volume 2: Engineering fundamentals of biotechnology
Y1  - 2011
SN  - 978-0-444-53352-4
U6  - https://doi.org/10.1016/B978-0-08-088504-9.00088-X
SP  - 93
EP  - 101
PB  - Elsevier
CY  - Amsterdam
ET  - 2. edition
ER  - 
TY  - JOUR
A1  - Mues genannt Koers, Lucas
A1  - Prevost, David
A1  - Paulßen, Elisabeth
A1  - Hoehr, Cornelia
T1  - Density reduction effects on the production of [11C]CO2 in Nb-body targets on a medical cyclotron
N2  - Medical isotope production of 11C is commonly performed in gaseous targets. The power deposition of the proton beam during the irradiation decreases the target density due to thermodynamic mixing and can cause an increase of penetration depth and divergence of the proton beam. In order to investigate the difference how the target-body length influences the operation conditions and the production yield, a 12 cm and a 22 cm Nb-target body containing N2/O2 gas were irradiated using a 13 MeV proton cyclotron. It was found that the density reduction has a large influence on the pressure rise during irradiation and the achievable radioactive yield. The saturation activity of [11C]CO2 for the long target (0.083 Ci/μA) is about 10% higher than in the short target geometry (0.075 Ci/μA).
Y1  - 2023
U6  - https://doi.org/10.1016/j.apradiso.2023.110911
VL  - 199
IS  - Art. 110911
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mues genannt Koers, Lucas
A1  - McNeil, S. W.
A1  - Radchenko, V.
A1  - Paulßen, Elisabeth
A1  - Hoehr, Cornelia
T1  - Production of Co-58m in a siphon-style liquid target on a medical cyclotron
N2  - We present the production of 58mCo on a small, 13 MeV medical cyclotron utilizing a siphon style liquid target system. Different concentrated iron(III)-nitrate solutions of natural isotopic distribution were irradiated at varying initial pressures and subsequently separated by solid phase extraction chromatography. The radio cobalt (58m/gCo and 56Co) was successfully produced with saturation activities of (0.35 ± 0.03) MBq μA−1 for 58mCo with a separation recovery of (75 ± 2) % of cobalt after one separation step utilizing LN-resin.
Y1  - 2023
U6  - https://doi.org/10.1016/j.apradiso.2023.110734
SN  - 0969-8043
VL  - 195
IS  - Art. 110734
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mueller, Tobias
A1  - Segin, Alexander
A1  - Weigand, Christoph
A1  - Schmitt, Robert H.
T1  - Feature selection for measurement models
JF  - International journal of quality & reliability management
N2  - Purpose
In the determination of the measurement uncertainty, the GUM procedure requires the building of a measurement model that establishes a functional relationship between the measurand and all influencing quantities. Since the effort of modelling as well as quantifying the measurement uncertainties depend on the number of influencing quantities considered, the aim of this study is to determine relevant influencing quantities and to remove irrelevant ones from the dataset.

Design/methodology/approach
In this work, it was investigated whether the effort of modelling for the determination of measurement uncertainty can be reduced by the use of feature selection (FS) methods. For this purpose, 9 different FS methods were tested on 16 artificial test datasets, whose properties (number of data points, number of features, complexity, features with low influence and redundant features) were varied via a design of experiments.

Findings
Based on a success metric, the stability, universality and complexity of the method, two FS methods could be identified that reliably identify relevant and irrelevant influencing quantities for a measurement model.

Originality/value
For the first time, FS methods were applied to datasets with properties of classical measurement processes. The simulation-based results serve as a basis for further research in the field of FS for measurement models. The identified algorithms will be applied to real measurement processes in the future.
KW  - Feature selection
KW  - Modelling
KW  - Measurement models
KW  - Measurement uncertainty
Y1  - 2022
U6  - https://doi.org/10.1108/IJQRM-07-2021-0245
SN  - 0265-671X
IS  - Vol. ahead-of-print, No. ahead-of-print.
PB  - Emerald Group Publishing Limited
CY  - Bingley
ER  - 
TY  - JOUR
A1  - Muck, A.
A1  - Wang, J.
A1  - Jacobs, M.
A1  - Chen, G.
A1  - Chatrathi, M. P.
A1  - Jurka, V.
A1  - Vyborny, Z.
A1  - Spillmann, S. D.
A1  - Sridharan, G.
A1  - Schöning, Michael Josef
T1  - Fabrication of poly(methyl methacrylate) microfluidic chips by atmospheric molding
JF  - Analytical Chemistry. 76 (2004), H. 8
Y1  - 2004
SN  - 0003-2700
SP  - 2290
EP  - 2297
ER  - 
TY  - JOUR
A1  - Mourzina, Yu.G.
A1  - Schöning, Michael Josef
A1  - Schubert, J.
A1  - Zander, W.
A1  - Legin, A.
A1  - Vlasov, Y. G.
A1  - Lüth, H.
T1  - Thin film microsensors for fast heavy metal analysis
JF  - Proceedings : Copenhagen, Denmark, 27 - 30 August 2000 / [ed.: R. de Reus ...]
Y1  - 2000
SN  - 87-89935-50-0
N1  - Eurosensors ; (14, 2000, København) ; Eurosensors ; (14 : ; 2000.08.27-30 : ; Copenhagen) ; European Conference on Solid-State Transducers ; (14 : ; 2000.08.27-30 : ; Copenhagen)
SP  - 839
EP  - 840
PB  - MIC, Mikroelektronik Centret
CY  - Lyngby, Denmark
ER  - 
TY  - JOUR
A1  - Mourzina, Yu. G.
A1  - Schubert, J
A1  - Zander, W.
A1  - Legin, A.
A1  - Vlasov, Y. G.
A1  - Lüth, H.
A1  - Schöning, Michael Josef
T1  - Development of multisensor systems based on chalcogenide thin film chemical sensors for the simultaneous multicomponent analysis of metal ions in complex solutions
JF  - Scaling down in electrochemistry : electrochemical micro- and nanosystem technology ; proceedings of the 3rd International Symposium on Electrochemical Microsystem Technologies, Garmisch-Patenkirchen, Germany, 11 - 15 September 2000 / ed. by J. W. Schultz
Y1  - 2001
SN  - 0-08-044014-2
SP  - 251
EP  - 263
PB  - Elsevier [u.a.]
CY  - Amsterdam [u.a.]
ER  - 
TY  - JOUR
A1  - Mourzina, Y.G.
A1  - Schöning, Michael Josef
A1  - Schubert, J.
A1  - Zander, W.
A1  - Legin, A. V.
A1  - Vlasov, Y. G.
A1  - Kordos, P.
A1  - Lüth, H.
T1  - A new thin film Pb microsensor based on chalcogenide glasses
JF  - Sensors and Actuators B. 71 (2000), H. 1-2
Y1  - 2000
SN  - 0925-4005
SP  - 13
EP  - 18
ER  - 
TY  - JOUR
A1  - Mourzina, Y.
A1  - Yoshinobu, T.
A1  - Ermelenko, Y.
A1  - Furuichi, K.
A1  - Vlasov, Y.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Technology of photocurable membranes for ion sensors based on laser scanned semiconductor transducer (LSST)
JF  - Book of abstracts / ed. by J. Saneistr.
Y1  - 2002
SN  - 80-01-02576-4
N1  - Eurosensors ; (16, 2002, Praha)
SP  - 254
EP  - 257
PB  - Czech Technical University, Faculty of Electrical Engineering, Department of Measurement
CY  - Prague
ER  - 
TY  - JOUR
A1  - Mourzina, Y.
A1  - Mai, T.
A1  - Poghossian, Arshak
A1  - Ermolenko, Y.
A1  - Yoshinobu, T.
A1  - Vlasov, Y.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - K+-selective field-effect sensors as transducers for bioelectronic applications
JF  - Electrochimica Acta. 48 (2003), H. 20-22
Y1  - 2003
SN  - 0013-4686
SP  - 3333
EP  - 3339
ER  - 
TY  - JOUR
A1  - Mourzina, Y. G.
A1  - Yoshinobu, T.
A1  - Schubert, J.
A1  - Lüth, H.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - Ion-selective lightaddressable potentiometric sensor (LAPS) with chalcogenide thin film by pulsed laser deposition
JF  - Sensors and Actuators B. 80 (2001), H. 2
Y1  - 2001
SN  - 0925-4005
SP  - 136
EP  - 140
ER  - 
TY  - JOUR
A1  - Mourzina, Y. G.
A1  - Schöning, Michael Josef
A1  - Schubert, J.
A1  - Zander, W.
A1  - Legin, A. V.
A1  - Vlasov, Y. G.
A1  - Lüth, H.
T1  - Copper, cadmium and thallium thin film sensors based on chalcogenide glasses
JF  - Analytica Chimica Acta. 433 (2001)
Y1  - 2001
SN  - 0378-4304
SP  - 103
EP  - 110
ER  - 
TY  - JOUR
A1  - Mourzina, Y. G.
A1  - Legin, A.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Schubert, J.
A1  - Zander, W.
A1  - Lüth, H.
T1  - Thin film chemical sensors based on chalcogenide glasses for „electronic tongue“ applications
JF  - Sensor 2001 : 10th international conference, May 8 - 10, 2001, Exhibition Centre Nuremberg, Germany ; proceedings
Y1  - 2001
N1  - Sensor-Kongress ; (10, 2001, Nürnberg) Sensor 2001 Conference ; (10 : ; 2001.05.08-10 : ; Nuremberg)
SP  - 137
EP  - 141
PB  - AMA Service
CY  - Wunstorf
ER  - 
TY  - JOUR
A1  - Mourzina, Y. G.
A1  - Ermelenko, Y. E.
A1  - Yoshinobu, T.
A1  - Vlasov, Y.
A1  - Iwasaki, H.
A1  - Schöning, Michael Josef
T1  - Anionselective light-addressable potentiometric sensors (LAPS) for the determination of nitrate and suphate ions
JF  - Sensors and Actuators B. 91 (2003), H. 1-3
Y1  - 2003
SN  - 0925-4005
SP  - 32
EP  - 38
ER  - 
TY  - JOUR
A1  - Mourzina, Ioulia G.
A1  - Yoshinobu, Tatsuo
A1  - Ermolenko, Yuri E.
A1  - Vlasov, Yuri G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Immobilization of urease and cholinesterase on the surface of semiconductor transducer for the development of lightaddressable potentiometric sensors
JF  - Microchimica Acta. 144 (2004), H. 1-3
Y1  - 2004
SN  - 0026-3672
SP  - 41
EP  - 50
ER  - 
TY  - JOUR
A1  - Mourzina, I.G.
A1  - Yoshinobu, T.
A1  - Ermolenko, Y.E.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Immobilization of urease and cholinesterase on the surface of semiconductor transducer for the development of light-addressable potentiometric sensors
JF  - Technical digest of the 10th International Meeting on Chemical Sensors, July 11 - 14, 2004, Tsukuba, Japan / Japan Association of Chemical Sensors
Y1  - 2004
N1  - Chemical sensors ; 20.2004 Suppl. B. IMCS ; (10, 2004, Tsukuba) ; International Meeting on Chemical Sensors ; (10 : ; 2004.07.11-14 : ; Tsukuba)
SP  - 788
EP  - 789
PB  - Japan Association of Chemical Sensors
CY  - Fukuoka
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Vosteen, Hans-Dieter
A1  - Schellschmidt, Rüdiger
T1  - Temperature dependence of the relationship of thermal diffusivity versus thermal conductivity for crystalline rocks
JF  - International Journal of Earth Sciences
Y1  - 2008
U6  - https://doi.org/10.1007/s00531-007-0238-3
SN  - 1437-3262
VL  - 97
IS  - 2
SP  - 435
EP  - 442
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Schwamborn, G.
A1  - Rath, V.
T1  - Past climate changes and permafrost depth at the Lake El'gygytgyn site: implications from data and thermal modeling
JF  - Climate of the Past
Y1  - 2013
U6  - https://doi.org/10.5194/cp-9-119-2013
SN  - 1814-9332
VL  - 9
IS  - 1
SP  - 119
EP  - 133
PB  - Copernicus
CY  - Katlenburg-Lindau
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Schellschmidt, R.
A1  - Popov, Y. A.
A1  - Clauser, C.
A1  - Kukkonen, I. T.
A1  - Nover, G.
A1  - Milanovsky, S.
A1  - Romushkevich, R. A.
T1  - New heat flow data from the immediate vicinity of the Kola super-deep borehole: Vertical variation in heat flow density confirmed and attributed to advection
JF  - Tectonophysics
Y1  - 2005
U6  - https://doi.org/10.1016/j.tecto.2005.03.005
SN  - 1879-3266
VL  - 401
IS  - 1-2
SP  - 119
EP  - 142
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Rath, Volker
T1  - Latent heat effects in subsurface heat transport modelling and their impact on palaeotemperature reconstructions
JF  - Geophysical Journal International
Y1  - 2006
U6  - https://doi.org/10.1111/j.1365-246X.2005.02843.x
SN  - 1365-246X
VL  - 164
IS  - 1
SP  - 236
EP  - 245
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Pechnig, Renate
A1  - Vogt, Christian
T1  - The geothermal project Den Haag: 3D numerical models for temperature prediction and reservoir simulation
JF  - Geothermics
N2  - The proposed Den Haag Zuidwest district heating system of the city of The Hague consists of a deep doublet in a Jurassic sandstone layer that is designed for a production temperature of 75 °C and a reinjection temperature of 40 °C at a flow rate of 150 m3 h−1. The prediction of reservoir temperature and production behavior is crucial for success of the proposed geothermal doublet. This work presents the results of a study of the important geothermal and geohydrological issues for the doublet design. In the first phase of the study, the influences of the three-dimensional (3D) structures of anticlines and synclines on the temperature field were examined. A comprehensive petrophysical investigation was performed to build a large scale 3D-model of the reservoir. Several bottomhole temperatures (BHTs), as well as petrophysical logs were used to calibrate the model using thermal conductivity measurements on 50 samples from boreholes in different lithological units in the study area. Profiles and cross sections extracted from the calculated temperature field were used to study the temperature in the surrounding areas of the planned doublet. In the second phase of the project, a detailed 3D numerical reservoir model was set up, with the aim of predicting the evolution of the producer and injector temperatures, and the extent of the cooled area around the injector. The temperature model from the first phase provided the boundary conditions for the reservoir model. Hydraulic parameters for the target horizons, such as porosity and permeability, were taken from data available from the nearby exploration wells. The simulation results are encouraging as no significant thermal breakthrough is predicted. For the originally planned location of the producer, the extracted water temperature is predicted to be around 79 °C, with an almost negligible cooling in the first 50 years of production. When the producer is located shallower parts of the reservoir, the yield water temperatures is lower, starting at ≈76 °C and decreasing to ≈74 °C after 50 years of operation. This comparatively larger decrease in temperature with time is caused by the structural feature of the reservoir, namely a higher dip causes the cooler water to easily move downward. In view of the poor reservoir data, the reservoir simulation model is constructed to allow iterative updates using data assimilation during planned drilling, testing, and production phases. Measurements during an 8 h pumping test carried out in late 2010 suggest that a flow rate of 150 m3 h−1 is achievable. Fluid temperatures of 76.5 °C were measured, which is very close to the predicted value.
Y1  - 2011
U6  - https://doi.org/10.1016/j.geothermics.2011.07.001
SN  - 0375-6505
VL  - 40
IS  - 3
SP  - 199
EP  - 210
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Mottaghy, Darius
A1  - Majorowicz, Jacek
A1  - Rath, Volker
T1  - Ground Surface Temperature Histories Reconstructed from Boreholes in Poland: Implications for Spatial Variability
T2  - The Polish Climate in the European Context: An Historical Overview
Y1  - 2009
SN  - 978-90-481-3167-9
U6  - https://doi.org/10.1007/978-90-481-3167-9_17
SP  - 375
EP  - 387
PB  - Springer Science+Business Media
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Mottaghy, Darius
A1  - Dijkshoorn, Lydia
T1  - Implementing an effective finite difference formulation for borehole heat exchangers into a heat and mass transport code
JF  - Renewable Energy
N2  - We present an effective finite difference formulation for implementing and modeling multiple borehole heat exchangers (BHE) in the general 3-D coupled heat and flow transport code SHEMAT. The BHE with arbitrary length can be either coaxial or double U-shaped. It is particularly suitable for modeling deep BHEs which contain varying pipe diameters and materials.

Usually, in numerical simulations, a fine discretization of the BHE assemblage is required, due to the large geometric aspect ratios involved. This yields large models and long simulation times. The approach avoids this problem by considering heat transport between fluid and the soil through pipes and grout via thermal resistances. Therefore, the simulation time can be significantly reduced.

The coupling with SHEMAT is realized by introducing an effective heat generation. Due to this connection, it is possible to consider heterogeneous geological models, as well as the influence of groundwater flow. This is particularly interesting when studying the long term behavior of a single BHE or a BHE field. Heating and cooling loads can enter the model with an arbitrary interval, e.g. from hourly to monthly values. When dealing with large BHE fields, computing times can be further significantly reduced by focusing on the temperature field around the BHEs, without explicitly modeling inlet and outlet temperatures. This allows to determine the possible migration of cold and warm plumes due to groundwater flow, which is of particular importance in urban areas with a high BHE installation density.

The model is validated against the existing BHE modeling codes EWS and EED. A comparison with monitoring data from a deep BHE in Switzerland shows a good agreement. Synthetic examples demonstrate the field of application of this model.
KW  - Borehole heat exchanger
KW  - Finite differences
KW  - Heat transport
Y1  - 2012
U6  - https://doi.org/10.1016/j.renene.2012.02.013
SN  - 0960-1481
VL  - 45
SP  - 59
EP  - 71
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Mosset, J.-B.
A1  - Devroede, O.
A1  - Krieguer, M.
A1  - Rey, M.
A1  - Vieira, J.-M.
A1  - Jung, J. H.
A1  - Kuntner, C.
A1  - Streun, M.
A1  - Ziemons, Karl
A1  - Auffray, E.
A1  - Sempere-Roldan, P.
A1  - Lecoq, P.
A1  - Bruyndonckx, P.
A1  - Loude, J.-F.
A1  - Tavernier, S.
A1  - Morcel, C.
T1  - Development of an optimized LSO/LuYAP phoswich detector head for the Lausanne ClearPET demonstrator
JF  - IEEE Transactions on Nuclear Science
N2  - This paper describes the LSO/LuYAP phoswich detector head developed for the ClearPET small animal PET scanner demonstrator that is under construction in Lausanne within the Crystal Clear Collaboration. The detector head consists of a dual layer of 8×8 LSO and LuYAP crystal arrays coupled to a multi-anode photomultiplier tube (Hamamatsu R7600-M64). Equalistion of the LSO/LuYAP light collection is obtained through partial attenuation of the LSO scintillation light using a thin aluminum deposit of 20-35 nm on LSO and appropriate temperature regulation of the phoswich head between 30°C to 60°C. At 511keV, typical FWHM energy resolutions of the pixels of a phoswich head amounts to (28±2)% for LSO and (25±2)% for LuYAP. The LSO versus LuYAP crystal identification efficiency is better than 98%. Six detector modules have been mounted on a rotating gantry. Axial and tangential spatial resolutions were measured up to 4 cm from the scanner axis and compared to Monte Carlo simulations using GATE. FWHM spatial resolution ranges from 1.3 mm on axis to 2.6 mm at 4 cm from the axis.
Y1  - 2006
SN  - 0018-9499
VL  - 53
IS  - 1
SP  - 25
EP  - 29
ER  - 
TY  - JOUR
A1  - Moseley, Fiona
A1  - Halamek, Jan
A1  - Kramer, Friederike
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
A1  - Katz, Evgeny
T1  - An enzyme-based reversible CNOT logic gate realized in a flow system
JF  - Analyst
N2  - An enzyme system organized in a flow device was used to mimic a reversible Controlled NOT (CNOT) gate with two input and two output signals. Reversible conversion of NAD⁺ and NADH cofactors was used to perform a XOR logic operation, while biocatalytic hydrolysis of p-nitrophenyl phosphate resulted in an Identity operation working in parallel. The first biomolecular realization of a CNOT gate is promising for integration into complex biomolecular networks and future biosensor/biomedical applications.
Y1  - 2014
U6  - https://doi.org/10.1039/C4AN00133H
SN  - 1364-5528 (E-Journal) ; 0003-2654 (Print)
VL  - 139
IS  - 8
SP  - 1839
EP  - 1842
PB  - Royal Society of Chemistry
CY  - Cambridge
ER  - 
TY  - CHAP
A1  - Moritz, Werner
A1  - Yoshinobu, Tatsuo
A1  - Finger, Friedhelm
A1  - Krause, Steffi
A1  - Schöning, Michael Josef
T1  - Amorphous silicon as semiconductor material for high resolution LAPS
T2  - Eurosensors XVII : the 17th European Conference on Solid-State Transducers ; University of Minho, Guimarães, Portugal, September 21 - 24, 2003
Y1  - 2003
SP  - 48
EP  - 49
ER  - 
TY  - JOUR
A1  - Moritz, W.
A1  - Yoshinobu, T.
A1  - Finger, F.
A1  - Krause, S.
A1  - Xu, M.
A1  - Schöning, Michael Josef
T1  - Microscopy of impedance and surface ion concentrations
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1000
EP  - 1001
ER  - 
TY  - JOUR
A1  - Moritz, W.
A1  - Yoshinobu, T.
A1  - Finger, F.
A1  - Krause, S.
A1  - Martin-Fernandez, M.
A1  - Schöning, Michael Josef
T1  - High resolution LAPS using amorphous silicon as the semiconductor material
JF  - Sensors and Actuators B. 103 (2004), H. 1-2
Y1  - 2004
SN  - 0925-4005
SP  - 436
EP  - 444
ER  - 
TY  - JOUR
A1  - Moret, J.L.T.M.
A1  - Alkemade, J.
A1  - Upcraft, T.M.
A1  - Paulßen, Elisabeth
A1  - Wolterbeek, H.T.
A1  - Ommen, J.R. van
A1  - Denkova, A.G.
T1  - The application of atomic layer deposition in the production of sorbents for ⁹⁹Mo/⁹⁹ᵐTc generator
JF  - Applied Radiation and Isotopes
N2  - New production routes for ⁹⁹Mo are steadily gaining importance. However, the obtained specific activity is much lower than currently produced by the fission of U-235. To be able to supply hospitals with ⁹⁹Mo/⁹⁹ᵐTc generators with the desired activity, the adsorption capacity of the column material should be increased. In this paper we have investigated whether the gas phase coating technique Atomic Layer Deposition (ALD), which can deposit ultra-thin layers on high surface area materials, can be used to attain materials with high adsorption capacity for ⁹⁹Mo. For this purpose, ALD was applied on a silica-core sorbent material to coat it with a thin layer of alumina. This sorbent material shows to have a maximum adsorption capacity of 120 mg/g and has a ⁹⁹ᵐTc elution efficiency of 55 ± 2% based on 3 executive elutions.
Y1  - 2020
U6  - https://doi.org/10.1016/j.apradiso.2020.109266
SN  - 0969-8043
VL  - 164
IS  - 109266
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Moreno, Lia
A1  - Dosev, D.
A1  - Bratov, A.
A1  - Dominguez, C.
A1  - Schöning, Michael Josef
A1  - Kloock, Joachim P.
T1  - Effect of electrical properties of the surrounding medium on the response of an interdigitated electrode array with chalcogenide glass film
T2  - XX Eurosensors : 20th anniversary ; Göteborg, Sweden, 17 - 20 September 2006 ; [proceedings]. - Vol. 1
Y1  - 2006
SN  - 978-91-631-9280-7
N1  - Paper number: T1A-P22
SP  - 384
EP  - 385
CY  - Göteborg
ER  - 
TY  - JOUR
A1  - Moreno i Codinachs, Lia
A1  - Kloock, Joachim P.
A1  - Schöning, Michael Josef
A1  - Baldi, Antoni
A1  - Ipatov, Andrey
A1  - Bratov, Andrey
A1  - Jimenez-Jorquera, Cecilia
T1  - Electronic integrated multisensor tongue applied to grape juice and wine analysis
JF  - Analyst. 133 (2008)
Y1  - 2008
SN  - 1364-5528
SP  - 1440
EP  - 1448
ER  - 
TY  - JOUR
A1  - Moreno i Codinachs, L.
A1  - Birkenstock, C.
A1  - Garma, T.
A1  - Zierold, R.
A1  - Bachmann, J.
A1  - Nielsch, K.
A1  - Schöning, Michael Josef
A1  - Fontcuberta i Morral, A.
T1  - A micron-sized nanoporous multifunction sensing device
JF  - physica status solidi (a) . 206 (2009), H. 3
Y1  - 2009
SN  - 1862-6319
N1  - Special Issue: Engineering of Functional Interfaces (EnFI 08)
SP  - 435
EP  - 441
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Morat, Mareike
A1  - Faude, Oliver
A1  - Hanssen, Henner
A1  - Ludyga, Sebastian
A1  - Zacher, Jonas
A1  - Eibl, Angi
A1  - Albracht, Kirsten
A1  - Donath, Lars
T1  - Agility Training to Integratively Promote Neuromuscular, Cognitive, Cardiovascular and Psychosocial Function in Healthy Older Adults: A Study Protocol of a One-Year Randomized-Controlled Trial
JF  - International Journal of Environmental Research and Public Health
N2  - Exercise training effectively mitigates aging-induced health and fitness impairments. Traditional training recommendations for the elderly focus separately on relevant physiological fitness domains, such as balance, flexibility, strength and endurance. Thus, a more holistic and functional training framework is needed. The proposed agility training concept integratively tackles spatial orientation, stop and go, balance and strength. The presented protocol aims at introducing a two-armed, one-year randomized controlled trial, evaluating the effects of this concept on neuromuscular, cardiovascular, cognitive and psychosocial health outcomes in healthy older adults. Eighty-five participants were enrolled in this ongoing trial. Seventy-nine participants completed baseline testing and were block-randomized to the agility training group or the inactive control group. All participants undergo pre- and post-testing with interim assessment after six months. The intervention group currently receives supervised, group-based agility training twice a week over one year, with progressively demanding perceptual, cognitive and physical exercises. Knee extension strength, reactive balance, dual task gait speed and the Agility Challenge for the Elderly (ACE) serve as primary endpoints and neuromuscular, cognitive, cardiovascular, and psychosocial meassures serve as surrogate secondary outcomes. Our protocol promotes a comprehensive exercise training concept for older adults, that might facilitate stakeholders in health and exercise to stimulate relevant health outcomes without relying on excessively time-consuming physical activity recommendations.
KW  - agility
KW  - prevention
KW  - healthy aging
KW  - community dwelling
KW  - psychosocial
Y1  - 2020
U6  - https://doi.org/10.3390/ijerph17061853
SN  - 1660-4601
VL  - 17
IS  - 6
SP  - 1
EP  - 14
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Morandi, Paolo
A1  - Butenweg, Christoph
A1  - Breis, Khaled
A1  - Beyer, Katrin
A1  - Magenes, Guido
ED  - Ansal, Atilla
T1  - Latest findings on the behaviour factor q for the seismic design of URM buildings
JF  - Bulletin of Earthquake Engineering
N2  - Recent earthquakes as the 2012 Emilia earthquake sequence showed that recently built unreinforced masonry (URM) buildings behaved much better than expected and sustained, despite the maximum PGA values ranged between 0.20–0.30 g, either minor damage or structural damage that is deemed repairable. Especially low-rise residential and commercial masonry buildings with a code-conforming seismic design and detailing behaved in general very well without substantial damages. The low damage grades of modern masonry buildings that was observed during this earthquake series highlighted again that codified design procedures based on linear analysis can be rather conservative. Although advances in simulation tools make nonlinear calculation methods more readily accessible to designers, linear analyses will still be the standard design method for years to come. The present paper aims to improve the linear seismic design method by providing a proper definition of the q-factor of URM buildings. These q-factors are derived for low-rise URM buildings with rigid diaphragms which represent recent construction practise in low to moderate seismic areas of Italy and Germany. The behaviour factor components for deformation and energy dissipation capacity and for overstrength due to the redistribution of forces are derived by means of pushover analyses. Furthermore, considerations on the behaviour factor component due to other sources of overstrength in masonry buildings are presented. As a result of the investigations, rationally based values of the behaviour factor q to be used in linear analyses in the range of 2.0–3.0 are proposed.
KW  - Unreinforced masonry buildings
KW  - Modern constructions
KW  - Seismic design
KW  - Linear elastic analysis
KW  - Behaviour factor q
Y1  - 2022
U6  - https://doi.org/10.1007/s10518-022-01419-7
SN  - 1573-1456
SN  - 1570-761X
VL  - 20
IS  - 11
SP  - 5797
EP  - 5848
PB  - Springer Nature
CY  - Cham
ER  - 
TY  - CHAP
A1  - Morandi, Paolo
A1  - Butenweg, Christoph
A1  - Breis, Khaled
A1  - Beyer, Katrin
A1  - Magenes, Guido
ED  - Arion, Christian
ED  - Scupin, Alexandra
ED  - Ţigănescu, Alexandru
T1  - Behaviour factor q for the seismic design of URM buildings
T2  - The Third European Conference on Earthquake Engineering and Seismology
N2  - Recent earthquakes showed that low-rise URM buildings following codecompliant seismic design and details behaved in general very well without substantial damages. Although advances in simulation tools make nonlinear calculation methods more readily accessible to designers, linear analyses will still be the standard design method for years to come. The present paper aims to improve the linear seismic design method by providing a proper definition of the q-factor of URM buildings. Values of q-factors are derived for low-rise URM buildings with rigid diaphragms, with reference to modern structural configurations realized in low to moderate seismic areas of Italy and Germany. The behaviour factor components for deformation and energy dissipation capacity and for overstrength due to the redistribution of forces are derived by means of pushover analyses. As a result of the investigations, rationally based values of the behaviour factor q to be used in linear analyses in the range of 2.0 to 3.0 are proposed.
KW  - unreinforced masonry buildings
KW  - modern constructions
KW  - seismic design
KW  - linear elastic analysis;
KW  - behaviour factor q
Y1  - 2022
SN  - 978-973-100-533-1
N1  - 3ECEES - Third European Conference on Earthquake Engineering and Seismology, September 4 – September 9, 2022, Bucharest
SP  - 1184
EP  - 1194
ER  - 
TY  - JOUR
A1  - Morais, Paulo V.
A1  - Suman, Pedro H.
A1  - Schöning, Michael Josef
A1  - Siqueira Junior, José R.
A1  - Orlandi, Marcelo O.
T1  - Layer-by-layer film based on Sn₃O₄ nanobelts as sensing units to detect heavy metals using a capacitive field-effect sensor platform
JF  - Chemosensors
N2  - Lead and nickel, as heavy metals, are still used in industrial processes, and are classified as “environmental health hazards” due to their toxicity and polluting potential. The detection of heavy metals can prevent environmental pollution at toxic levels that are critical to human health. In this sense, the electrolyte–insulator–semiconductor (EIS) field-effect sensor is an attractive sensing platform concerning the fabrication of reusable and robust sensors to detect such substances. This study is aimed to fabricate a sensing unit on an EIS device based on Sn₃O₄ nanobelts embedded in a polyelectrolyte matrix of polyvinylpyrrolidone (PVP) and polyacrylic acid (PAA) using the layer-by-layer (LbL) technique. The EIS-Sn₃O₄ sensor exhibited enhanced electrochemical performance for detecting Pb²⁺ and Ni²⁺ ions, revealing a higher affinity for Pb²⁺ ions, with sensitivities of ca. 25.8 mV/decade and 2.4 mV/decade, respectively. Such results indicate that Sn₃O₄ nanobelts can contemplate a feasible proof-of-concept capacitive field-effect sensor for heavy metal detection, envisaging other future studies focusing on environmental monitoring.
KW  - Sn₃O₄
KW  - nanobelts
KW  - field-effect sensor
KW  - LbL films
KW  - heavy metals
Y1  - 2023
U6  - https://doi.org/10.3390/chemosensors11080436
SN  - 2227-9040
N1  - This article belongs to the Special Issue The Application of Electrochemical Sensors or Biosensors Based on Nanomaterials
VL  - 11
IS  - 8
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Morais, Paulo V.
A1  - Silva, Anielle C. A.
A1  - Dantas, Noelio O.
A1  - Schöning, Michael Josef
A1  - Siqueira, José R., Jr.
T1  - Hybrid Layer‐by‐Layer Film of Polyelectrolytes‐Embedded Catalytic CoFe2O4 Nanocrystals as Sensing Units in Capacitive Electrolyte‐Insulator‐Semiconductor Devices
JF  - physica status solidi a : applications and materials sciences
Y1  - 2019
U6  - https://doi.org/10.1002/pssa.201900044
VL  - 216
IS  - 1900044
SP  - 1
EP  - 9
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Morais, Paulo V.
A1  - Gomes, Vanderley F., Jr.
A1  - Silva, Anielle C. A.
A1  - Dantas, Noelio O.
A1  - Schöning, Michael Josef
A1  - Siqueira, José R., Jr.
T1  - Nanofilm of ZnO nanocrystals/carbon nanotubes as biocompatible layer for enzymatic biosensors in capacitive field-effect devices
JF  - Journal of Materials Science
N2  - The incorporation of nanomaterials that are biocompatible with different types of biological compounds has allowed the development of a new generation of biosensors applied especially in the biomedical field. In particular, the integration of film-based nanomaterials employed in field-effect devices can be interesting to develop biosensors with enhanced properties. In this paper, we studied the fabrication of sensitive nanofilms combining ZnO nanocrystals and carbon nanotubes (CNTs), prepared by means of the layer-by-layer (LbL) technique, in a capacitive electrolyte-insulator-semiconductor (EIS) structure for detecting glucose and urea. The ZnO nanocrystals were incorporated in a polymeric matrix of poly(allylamine) hydrochloride (PAH), and arranged with multi-walled CNTs in a LbL PAH-ZnO/CNTs film architecture onto EIS chips. The electrochemical characterizations were performed by capacitance–voltage and constant capacitance measurements, while the morphology of the films was characterized by atomic force microscopy. The enzymes glucose oxidase and urease were immobilized on film’s surface for detection of glucose and urea, respectively. In order to obtain glucose and urea biosensors with optimized amount of sensitive films, we investigated the ideal number of bilayers for each detection system. The glucose biosensor showed better sensitivity and output signal for an LbL PAH-ZnO/CNTs nanofilm with 10 bilayers. On the other hand, the urea biosensor presented enhanced properties even for the first bilayer, exhibiting high sensitivity and output signal. The presence of the LbL PAH-ZnO/CNTs films led to biosensors with better sensitivity and enhanced response signal, demonstrating that the adequate use of nanostructured films is feasible for proof-of-concept biosensors with improved properties that may be employed for biomedical applications.
Y1  - 2017
U6  - https://doi.org/10.1007/s10853-017-1369-y
SN  - 1573-4803
VL  - 52
IS  - 20
SP  - 12314
EP  - 12325
PB  - Springer
CY  - Berlin
ER  - 
TY  - JOUR
A1  - Moosdorf, Andreas
T1  - It’s not just the Talent, it’s the Knowledge Transfer Method
JF  - GC Ticker
Y1  - 2009
IS  - 1
SP  - 16
EP  - 16
ER  - 
TY  - BOOK
A1  - Moosdorf, Andreas
T1  - The determinants of international knowledge transfer effectiveness - conceptual advances and empirical verification
Y1  - 2008
N1  - The University of Leeds > Leeds University Business School. Thesis (PhD)
ER  - 
TY  - JOUR
A1  - Monti, Elena
A1  - Waldvogel, Janice
A1  - Ritzmann, Ramona
A1  - Freyler, Kathrin
A1  - Albracht, Kirsten
A1  - Helm, Michael
A1  - De Cesare, Niccolò
A1  - Pavan, Piero
A1  - Reggiani, Carlo
A1  - Gollhofer, Albert
A1  - Narici, Marco Vincenzo
T1  - Muscle in variable gravity: “I do not know where I am, but I know what to do”
JF  - Frontiers in Physiology
N2  - Performing tasks, such as running and jumping, requires activation of the agonist and antagonist muscles before (motor unit pre-activation) and during movement performance (Santello and Mcdonagh, 1998). A well-timed and regulated muscle activation elicits a stretch-shortening cycle (SSC) response, naturally occurring in bouncing movements (Ishikawa and Komi, 2004; Taube et al., 2012). By definition, the SSC describes the stretching of a pre-activated muscle-tendon complex immediately followed by a muscle shortening in the concentric push-off phase (Komi, 1984).
Given the importance of SSC actions for human movement, it is not surprising that many studies investigated the biomechanics of this phenomenon; in particular, drop jumps (DJs) represent a good paradigm to study muscle fascicle and tendon behavior in ballistic movements involving the SSC.
Within a DJ, three main phases [pre-activation, braking, and push-off (PO; Komi, 2000)] have been recognized and extensively studied in common and challenging conditions, such as changes in load, falling height, or simulated hypo-gravity (Avela et al., 1994; Arampatzis et al., 2001; Fukashiro et al., 2005; Ishikawa et al., 2005; Sousa et al., 2007; Ritzmann et al., 2016; Helm et al., 2020).
These studies show that the timing and amount of triceps-surae muscle-tendon unit pre-activation in DJs are differentially regulated based on the load applied to the muscle, being optimal in normal “Earth” gravity conditions (Avela et al., 1994), but decreased in simulated hypo-gravity, hyper-gravity (Avela et al., 1994; Ritzmann et al., 2016), or unknown conditions (i.e., unknown falling heights; Helm et al., 2020). Some authors indicated that, when falling from heights different from the optimal one [defined as the drop height giving a maximum DJ performance indicated as peak ground reaction force (GRF) or jump high], electromyographic (EMG) activity of the plantar flexors increases from lower than optimal to higher than optimal heights (Ishikawa and Komi, 2004; Sousa et al., 2007).
These findings highlight the ability of the central nervous system to regulate the timing and amount of pre-activation according to different jumping conditions, thus regulating muscle fascicle length, tendon and joint stiffness as well as position, in order to safely land on the ground and quickly re-bounce.
Similarly, to pre-activation, also in the braking phase, the plantar flexors are differentially regulated. In optimal height (i.e., load) jumping conditions, gastrocnemius medialis (GM) fascicles shorten at early ground contact (possibly due to the intervention of the stretch reflex; Gollhofer et al., 1992) and behave quasi-isometrically in the late braking phase, enabling tendon elongation, and storage of elastic energy (Gollhofer et al., 1992; Fukashiro et al., 2005; Sousa et al., 2007). When increasing the falling height (augmenting the impact GRF), the quasi-isometric behavior of fascicles disappears, and fast fascicle lengthening occurs (Ishikawa et al., 2005; Sousa et al., 2007).
In the third and last PO phase, fascicles shorten and the tendon releases the elastic energy previously stored. Bobbert et al. (1987) reported no influence of jumping height on the work done and on the net vertical impulse assessed during PO; this observation suggests that, despite an optimal DJ performance might be achieved only in specific conditions (falling heights, loads), the central nervous system seems to be able to regulate muscle behavior in order to effectively perform the required task also in challenging situations.
Although the regulation of triceps-surae muscle-tendon unit in DJs has been extensively investigated, very few studies focused on sarcomeres behavior during the performance of this SSC movement (Kurokawa et al., 2003; Fukashiro et al., 2005, 2006). Sarcomeres represent muscle contractile units and are known to express different amounts of force depending on their length (Gordon et al., 1966; Walker and Schrodt, 1974); thus, understanding the time course of their responses during DJs is fundamental to gain further insights into muscle force-generating capacity. In vivo measurement of sarcomere length in humans has been so far been performed only in static positions and under highly controlled experimental conditions (Llewellyn et al., 2008; Sanchez et al., 2015). Instead, human sarcomere length estimation (achieved by dividing GM measured fascicle length for a fixed sarcomere number) in dynamic contractions provided an indirect measure of sarcomere operating range during squat jump, countermovement jump, and DJ (Fukashiro et al., 2005, 2006; Kurokawa et al., 2003). The results of these studies showed that sarcomeres operate in the ascending limb of their length-tension (L-T) relationship in all types of jumps, and particularly so in DJ.
However, most of the available observations on sarcomere and muscle fascicle behavior were made in condition of constant gravity. Thus, in order to understand how sarcomere and muscle fascicle length are regulated in variable gravity conditions, we performed experiments in a parabolic flight, involving variable gravity levels, ranging from about zero-g to about double the Earth’s gravity (1 g; Waldvogel et al., 2021).
Specifically, the aims of the present study were as follows:
1. To investigate the ability of the neuromuscular system in regulating fascicle length in response to conditions of variable gravity.
2. To estimate sarcomere operative length in the different DJ phases, in order to calculate its theoretical force production and its possible modulation in conditions of variable gravity.
We hypothesized that muscle fascicles would be differentially regulated in different gravity conditions compared to 1 g, particularly in anticipation of landing and re-bouncing in unknown gravity levels. In addition, we hypothesized that sarcomeres would operate in the upper part of the ascending limb of their L-T relationship, possibly lengthening during the braking phase (especially in hyper-gravity) while operating quasi-isometrically in 1 g.
KW  - parabolic flight
KW  - drop jump
KW  - hypo-gravity
KW  - hyper-gravity
KW  - sarcomere operating length
Y1  - 2021
U6  - https://doi.org/10.3389/fphys.2021.714655
SN  - 1664-042X
VL  - 12
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  -