TY  - JOUR
A1  - Oertel, Mario
A1  - Bung, Daniel B.
T1  - Initial stage of two-dimensional dam-break waves: laboratory versus VOF
JF  - Journal of hydraulic research
N2  - Since several decades, dam-break waves have been of main research interest. Mathematical approaches have been developed by analytical, physical and numerical models within the past 120 years. During the past 10 years, the number of research investigations has increased due to improved measurement techniques as well as significantly increased computer memories and performances. In this context, the present research deals with the initial stage of two-dimensional dam-break waves by comparing physical and numerical model results as well as analytical approaches. High-speed images and resulting particle image velocimetry calculations are thereby compared with the numerical volume-of-fluid (VOF) method, included in the commercial code FLOW-3D. Wave profiles and drag forces on placed obstacles are analysed in detail. Generally, a good agreement between the laboratory and VOF results is found.
KW  - VOF
KW  - PIV
KW  - physical model
KW  - numerical model
KW  - drag force
KW  - dam-break
Y1  - 2012
U6  - http://dx.doi.org/10.1080/00221686.2011.639981
SN  - 1814-2079 (E-Journal); 0022-1686 (Print)
VL  - 50
IS  - 1
SP  - 89
EP  - 97
PB  - Taylor & Francis
CY  - London
ER  - 
TY  - CHAP
A1  - Oertel, Mario
A1  - Bung, Daniel B.
T1  - Characteristics of cross-bar block ramp flows
T2  - Hydraulic structures into the 21st century : 4th IAHR International Symposium on Hydraulic Structures : 9.-11.2.2012, Porto
Y1  - 2012
SN  - 978-989-8509-01-7
ER  - 
TY  - CHAP
A1  - Oertel, Mario
A1  - Bung, Daniel B.
A1  - Schlenkhoff, Andreas
ED  - Carstensen, Dirk
T1  - Blocksteinrampen in Riegelbauweise : Neue Bemessungsansätze
T2  - Staubauwerke : planen, bauen, betreiben; 35. Dresdner Wasserbaukolloquium 2012, 08. - 09. März 2012
Y1  - 2012
SN  - 978-3-86780-261-1
SP  - 317
EP  - 326
PB  - Selbstverl. der Techn. Univ.
CY  - Dresden
ER  - 
TY  - THES
A1  - Oflaz, Hakan
T1  - Entwicklung eines Prototypen zur Prognose von Frühgeburten : ein biomedizintechnischer Ansatz
Y1  - 2012
U6  - http://dx.doi.org/10.4126/38m-004639208
N1  - Köln, Univ., Diss., 2012
PB  - Deutsche Zentralbibliothek für Medizin
CY  - Köln
ER  - 
TY  - JOUR
A1  - Olaru, Alexandra Maria
A1  - Kowalski, Julia
A1  - Sethi, Vaishali
A1  - Blümich, Bernhard
T1  - Exchange relaxometry of flow at small Péclet numbers in a glass bead pack
JF  - Journal of Magnetic Resonance (JMR)
N2  - In this paper we consider low Péclet number flow in bead packs. A series of relaxation exchange experiments has been conducted and evaluated by ILT analysis. In the resulting correlation maps, we observed a collapse of the signal and a translation towards smaller relaxation times with increasing flow rates, as well as a signal tilt with respect to the diagonal. In the discussion of the phenomena we present a mathematical theory for relaxation exchange experiments that considers both diffusive and advective transport. We perform simulations based on this theory and discuss them with respect to the conducted experiments.
KW  - NMR exchange relaxometry
KW  - Low-field NMR
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.jmr.2012.04.015
SN  - 1096-0856
VL  - 220
SP  - 32
EP  - 44
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Olbertz, Klaus
T1  - Übergang von Leiharbeitnehmern bei Übertragung des Entleiherbetriebs - Entscheidung des EuGH zum Recht des Betriebsübergangs
JF  - NWB - Steuer- und Wirtschaftsrecht
N2  - Wieder einmal hat eine Entscheidung des Europäischen Gerichtshofs (EuGH) das bisherige nationale Verständnis zu einer Frage des Rechts des Betriebsübergangs erheblich ins Wanken gebracht. Bisher entsprach es allgemeiner Auffassung, dass die Arbeitsverhältnisse von Zeit- bzw. Leiharbeitnehmern bei einem Betriebs(teil)übergang des die Leiharbeitnehmer entleihenden Betriebs nicht auf den Betriebserwerber übergehen. Der EuGH hat in der Rechtssache Albron Catering mit Urteil vom 21.10.2010 jedoch entschieden, dass auch Leiharbeitnehmer von einem Betriebs(teil)übergang erfasst sein können. Folglich kann der Erwerber eines Betriebs oder Betriebsteils gem. § 613a BGB zukünftig verpflichtet sein, auch die an den Betriebsveräußerer verliehenen Leiharbeitnehmer zu übernehmen. Die Entscheidung des EuGH hat somit zur Konsequenz, dass der Übergang von Leiharbeitsverhältnissen auf den Erwerber eines Betriebs jedenfalls nicht mehr pauschal ausgeschlossen werden kann. Dies gilt es bei künftigen Betriebs(teil)übertragungen zu berücksichtigen, um unliebsame Überraschungen zu vermeiden.
Y1  - 2018
SN  - 1860-9449
IS  - 5
SP  - 398
EP  - 403
PB  - NWB-Verlag
CY  - Herne
ER  - 
TY  - JOUR
A1  - Olbertz, Klaus
A1  - Fahrig, Stephan
T1  - Offshoring als Betriebs(teil)übergang gemäß § 613a BGB
JF  - ZIP Zeitschrift für Wirtschaftsrecht
Y1  - 2018
SN  - 0723-9416
N1  - gedruckt in der Bereichsbibliothek Eupener Str. unter der Signatur 43 Z 548 vorhanden
IS  - 42
SP  - 2045
PB  - Verlag Dr. Otto Schmidt
CY  - Köln
ER  - 
TY  - JOUR
A1  - Orzada, S.
A1  - Maderwald, S.
A1  - Poser, B. A.
A1  - Johst, S.
A1  - Kannengiesser, S.
A1  - Ladd, M. E.
A1  - Bitz, Andreas
T1  - Time-interleaved acquisition of modes: an analysis of SAR and image contrast implications
JF  - Magnetic Resonance in Medicine
N2  - s the magnetic field strength and therefore the operational frequency in MRI are increased, the radiofrequency wavelength approaches the size of the human head/body, resulting in wave effects which cause signal decreases and dropouts. Especially, whole-body imaging at 7 T and higher is therefore challenging. Recently, an acquisition scheme called time-interleaved acquisition of modes has been proposed to tackle the inhomogeneity problems in high-field MRI. The basic premise is to excite two (or more) different Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-1 modes using static radiofrequency shimming in an interleaved acquisition, where the complementary radiofrequency patterns of the two modes can be exploited to improve overall signal homogeneity. In this work, the impact of time-interleaved acquisition of mode on image contrast as well as on time-averaged specific absorption rate is addressed in detail. Time-interleaved acquisition of mode is superior in Burn:x-wiley:07403194:media:MRM23081:tex2gif-stack-2 homogeneity compared with conventional radiofrequency shimming while being highly specific absorption rate efficient. Time-interleaved acquisition of modes can enable almost homogeneous high-field imaging throughout the entire field of view in PD, T2, and T2*-weighted imaging and, if a specified homogeneity criterion is met, in T1-weighted imaging as well.
Y1  - 2012
U6  - http://dx.doi.org/10.1002/mrm.23081
SN  - 1522-2594
VL  - 67
IS  - 4
SP  - 1033
EP  - 1041
PB  - Wiley-Liss
CY  - New York
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Kong, Shushu
A1  - Arciszewski, Pawel
A1  - Wielbalck, Swantje
A1  - Abram, Ulrich
T1  - Aryl and NHC Compounds of Technetium and Rhenium
JF  - Journal of the American Chemical Society
N2  - Air- and water-stable phenyl complexes with nitridotechnetium(V) cores can be prepared by straightforward procedures. [TcNPh2(PPh3)2] is formed by the reaction of [TcNCl2(PPh3)2] with PhLi. The analogous N-heterocyclic carbene (NHC) compound [TcNPh2(HLPh)2], where HLPh is 1,3,4-triphenyl-1,2,4-triazol-5-ylidene, is available from (NBu4)[TcNCl4] and HLPh or its methoxo-protected form. The latter compound allows the comparison of different Tc–C bonds within one compound. Surprisingly, the Tc chemistry with such NHCs does not resemble that of corresponding Re complexes, where CH activation and orthometalation dominate.
Y1  - 2012
U6  - http://dx.doi.org/10.1021/ja3033718
SN  - 1520-5126
VL  - 134
IS  - 22
SP  - 9118
EP  - 9121
PB  - ACS Publications
CY  - Washington, DC
ER  - 
TY  - JOUR
A1  - Paulßen, Elisabeth
A1  - Ngyugen, Hung Huy
A1  - Kahlcke, Nils
A1  - Deflon, Victor M.
A1  - Abram, Ulrich
T1  - Tricarbonyltechnetium(I) and -rhenium(I) complexes with N′-thiocarbamoylpicolylbenzamidines
JF  - Polyhedron
N2  - N,N-Dialkylamino(thiocarbonyl)-N′-picolylbenzamidines react with (NEt4)2[M(CO)3X3] (M = Re, X = Br; M = Tc, X = Cl) under formation of neutral [M(CO)3L] complexes in high yields. The monoanionic NNS ligands bind in a facial coordination mode and can readily be modified at the (CS)NR1R2 moiety. The complexes [99Tc(CO)3(LPyMor)] and [Re(CO)3(L)] (L = LPyMor, LPyEt) were characterized by X-ray diffraction. Reactions of [99mTc(CO)3(H2O)3]+ with the N′-thiocarbamoylpicolylbenzamidines give the corresponding 99mTc complexes. The ester group in HLPyCOOEt allows linkage between biomolecules and the metal core.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.poly.2012.04.008
SN  - 0277-5387
VL  - 40
IS  - 1
SP  - 153
EP  - 158
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Pham, Phu Tinh
A1  - Nguyen, Thanh Ngoc
A1  - Staat, Manfred
T1  - FEM based shakedown analysis of hardening structures
T2  - Proceedings International Conference on Advances in Computational Mechanics (ACOME)
Y1  - 2012
N1  - International Conference on Advances in Computational Mechanics (ACOME), August 14-16, 2012, Ho Chi Minh City, Vietnam
SP  - 870
EP  - 882
ER  - 
TY  - JOUR
A1  - Pieper, Martin
A1  - Klein, Peter
T1  - Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media
JF  - Heat mass transfer
N2  - Often, detailed simulations of heat conduction in complicated, porous media have large runtimes. Then homogenization is a powerful tool to speed up the calculations by preserving accurate solutions at the same time. Unfortunately real structures are generally non-periodic, which requires unpractical, complicated homogenization techniques. We demonstrate in this paper, that the application of simple, periodic techniques to realistic media, that are just close to periodic, gives accurate, approximative solutions. In order to obtain effective parameters for the homogenized heat equation, we have to solve a so called “cell problem”. In contrast to periodic structures it is not trivial to determine a suitable unit cell, which represents a non-periodic media. To overcome this problem, we give a rule of thumb on how to choose a good cell. Finally we demonstrate the efficiency of our method for virtually generated foams as well as real foams and compare these results to periodic structures.
Y1  - 2012
U6  - http://dx.doi.org/10.1007/s00231-011-0879-4
SN  - 0947-7411
VL  - 48
IS  - 2
SP  - 291
EP  - 300
PB  - Springer
CY  - Berlin
ER  - 
TY  - CHAP
A1  - Poghossian, Arshak
A1  - Abouzar, Maryam H.
A1  - Schöning, Michael Josef
ED  - Abdelghani, Adnane
ED  - Schöning, Michael Josef
T1  - (Bio-­)chemical sensor array based on nanoplate SOI capacitors
T2  - Nanoscale Science and Technology (NS&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012
Y1  - 2012
SP  - 31
EP  - 31
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Weil, M. H.
A1  - Bäcker, Matthias
A1  - Mayer, D.
A1  - Schöning, Michael Josef
T1  - Field-effect Devices Functionalised with Gold-Nanoparticle/Macromolecule Hybrids: New Opportunities for a Label-Free Biosensing
JF  - Procedia Engineering
N2  - Field-effect capacitive electrolyte-insulator-semiconductor (EIS) sensors functionalised with citrate-capped gold nanoparticles (AuNP) have been used for the electrostatic detection of macromolecules by their intrinsic molecular charge. The EIS sensor detects the charge changes in the AuNP/macromolecule hybrids induced by the adsorption or binding events. A feasibility of the proposed detection scheme has been exemplary demonstrated by realising EIS sensors for the detection of poly-D-lysine molecules.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.proeng.2012.09.136
SN  - 1877-7058
N1  - Part of special issue "26th European Conference on Solid-State Transducers, EUROSENSOR 2012"
IS  - 47
SP  - 273
EP  - 276
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Quadflieg, Till
A1  - Schoene, Jens
A1  - Schleser, Markus
A1  - Jockenhövel, Stefan
A1  - Reisgen, Uwe
A1  - Gries, Thomas
ED  - Heslehurst, Rikard Benton
T1  - Shear connectors for hybrid joints of metal and FRP
T2  - Diversity in composites : conference proceedings : Composites Australia and CRC-ACS 2012 conference
Y1  - 2012
SN  - 978-0-9873285-0-2
SP  - [152]
EP  - [160]
PB  - Composites Australia
CY  - Hawthorne
ER  - 
TY  - CHAP
A1  - Reisert, Steffen
A1  - Geissler, H.
A1  - Flörke, R.
A1  - Weiler, C.
A1  - Wagner, P.
A1  - Schöning, Michael Josef
ED  - Abdelghani, Adnane
ED  - Schöning, Michael Josef
T1  - Characterisation of aseptic sterilisation processes using an electronic nose
T2  - Nanoscale Science and Technology (NS&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012
Y1  - 2012
SP  - 45
EP  - 45
ER  - 
TY  - JOUR
A1  - Reisgen, Uwe
A1  - Olschok, Simon
A1  - Jakobs, Stefan
A1  - Schleser, Markus
A1  - Mokrov, Oleg
A1  - Rossiter, Eduardo
T1  - Laser beam submerged arc hybrid welding
JF  - Physics procedia
N2  - The laser beam-submerged arc hybrid welding method originates from the knowledge that, with increasing penetration depth, the laser beam process has a tendency to pore formation in the lower weld regions. The coupling with the energy-efficient submerged-arc process improves degassing and reduces the tendency to pore formation. The high deposition rate of the SA process in combination with the laser beam process offers, providing the appropriate choice of weld preparation, the possibility of welding plates with a thickness larger than 20° mm in a single pass, and also of welding thicker plates with the double-sided single pass technique.
Y1  - 2012
U6  - http://dx.doi.org/10.1016/j.phpro.2012.10.016
SN  - 1875-3892
N1  - Part of special issue "Laser assisted net shape engineering 7 (LANE 2012)"
VL  - 39
SP  - 75
EP  - 83
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - CHAP
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
A1  - Gumenyuk, Andrej
T1  - Application of electron beam welding to fabrication of steel-aluminium dissimilar joint
T2  - Beam technologies & laser application : proceedings of the VII international conference, Saint Petersburg, Sept. 18-21, 2012
Y1  - 2012
SP  - 265
EP  - 279
PB  - Publ. House
CY  - Saint Petersburg
ER  - 
TY  - JOUR
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
A1  - Gumenyuk, Andrey
T1  - Measuring of plasma properties induced by non-vacuum electron beam welding
JF  - Physics of plasma
N2  - Electron beam plasma measurement was realised by means of DIABEAM system invented by ISF RWTH Aachen. The Langmuir probe method is used for measurement. The relative simplicity of the method and the possibility of dispersion of high power on the probe allow its application for the investigation of high-power electron beams. The key element of the method is a rotating thin tungsten wire, which intersects the beam transversely on its axis and collects part of the current by itself. The signals, which are registered in the DIABEAM as a voltage, were taken in the form of amplitude. The conversion of the probe current into the distribution along the beam radius was realised using the Abel’s method. A voltage-current characteristic was built for the beam current. The local electron density as well as the electron temperature, the floating potential and the plasma potential were measured and calculated by means of this characteristic.
Y1  - 2012
U6  - http://dx.doi.org/10.1063/1.3675874
SN  - 1089-7674 (E-Journal); 1070-664X (Print)
VL  - 19
IS  - 1
SP  - 1
EP  - 7
PB  - AIP Publishing
CY  - Melville, NY
ER  - 
TY  - JOUR
A1  - Reisgen, Uwe
A1  - Schleser, Markus
A1  - Abdurakhmanov, Aydemir
A1  - Turichin, Gleb
A1  - Valdaitseva, Elena
A1  - Bach, Friedrich-Wilhelm
A1  - Hassel, Thomas
A1  - Beniyashi, Alexander
T1  - Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding
JF  - The Paton welding journal
N2  - The influence of welding condition parameters and properties of material on formation of defects, such as humping and undercuts, in non-vacuum electron beam welding was investigated. The influence of separate welding parameters on the quality of welds was determined.
Y1  - 2012
SN  - 0957-798X
VL  - 2012
IS  - 2
SP  - 11
EP  - 18
PB  - Paton Publishing House
CY  - Kiev
ER  -