@article{RauschHarbrechtKahmannetal.2020, author = {Rausch, Valentin and Harbrecht, Andreas and Kahmann, Stephanie Lucina and Fenten, Thomas and Jovanovic, Nebojsa and Hackl, Michael and M{\"u}ller, Lars P. and Staat, Manfred and Wegmann, Kilian}, title = {Osteosynthesis of Phalangeal Fractures: Biomechanical Comparison of Kirschner Wires, Plates, and Compression Screws}, series = {The Journal of Hand Surgery}, volume = {45}, journal = {The Journal of Hand Surgery}, number = {10}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0363-5023}, doi = {10.1016/j.jhsa.2020.04.010}, pages = {987.e1 -- 987.e8}, year = {2020}, abstract = {Purpose The aim of this study was to compare several osteosynthesis techniques (intramedullary headless compression screws, T-plates, and Kirschner wires) for distal epiphyseal fractures of proximal phalanges in a human cadaveric model. Methods A total of 90 proximal phalanges from 30 specimens (index, ring, and middle fingers) were used for this study. After stripping off all soft tissue, a transverse distal epiphyseal fracture was simulated at the proximal phalanx. The 30 specimens were randomly assigned to 1 fixation technique (30 per technique), either a 3.0-mm intramedullary headless compression screw, locking plate fixation with a 2.0-mm T-plate, or 2 oblique 1.0-mm Kirschner wires. Displacement analysis (bending, distraction, and torsion) was performed using optical tracking of an applied random speckle pattern after osteosynthesis. Biomechanical testing was performed with increasing cyclic loading and with cyclic load to failure using a biaxial torsion-tension testing machine. Results Cannulated intramedullary compression screws showed significantly less displacement at the fracture site in torsional testing. Furthermore, screws were significantly more stable in bending testing. Kirschner wires were significantly less stable than plating or screw fixation in any cyclic load to failure test setup. Conclusions Intramedullary compression screws are a highly stable alternative in the treatment of transverse distal epiphyseal phalangeal fractures. Kirschner wires seem to be inferior regarding displacement properties and primary stability. Clinical relevance Fracture fixation of phalangeal fractures using plate osteosynthesis may have the advantage of a very rigid reduction, but disadvantages such as stiffness owing to the more invasive surgical approach and soft tissue irritation should be taken into account. Headless compression screws represent a minimally invasive choice for fixation with good biomechanical properties.}, language = {en} } @inproceedings{RauschLeiseEdereretal.2016, author = {Rausch, Lea and Leise, Philipp and Ederer, Thorsten and Altherr, Lena and Pelz, Peter F.}, title = {A comparison of MILP and MINLP solver performance on the example of a drinking water supply system design problem}, series = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering}, booktitle = {ECCOMAS Congress 2016 VII European Congress on Computational Methods in Applied Sciences and Engineering}, editor = {Papadrakakis, M. and Ppadopoulos, V. and Stefanou, G. and Plevris, V.}, isbn = {978-618-82844-0-1}, pages = {8509 -- 8527}, year = {2016}, abstract = {Finding a good system topology with more than a handful of components is a highly non-trivial task. The system needs to be able to fulfil all expected load cases, but at the same time the components should interact in an energy-efficient way. An example for a system design problem is the layout of the drinking water supply of a residential building. It may be reasonable to choose a design of spatially distributed pumps which are connected by pipes in at least two dimensions. This leads to a large variety of possible system topologies. To solve such problems in a reasonable time frame, the nonlinear technical characteristics must be modelled as simple as possible, while still achieving a sufficiently good representation of reality. The aim of this paper is to compare the speed and reliability of a selection of leading mathematical programming solvers on a set of varying model formulations. This gives us empirical evidence on what combinations of model formulations and solver packages are the means of choice with the current state of the art.}, language = {en} } @inproceedings{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Pelz, Peter F.}, title = {Using mixed-integer programming for the optimal design of water supply networks for slums}, series = {Operations Research Proceedings 2017}, booktitle = {Operations Research Proceedings 2017}, editor = {Kliewer, Natalia and Ehmke, Jan Fabian and Bornd{\"o}rfer, Ralf}, publisher = {Springer}, address = {Cham}, isbn = {978-3-319-89919-0 (Print)}, doi = {10.1007/978-3-319-89920-6_68}, pages = {509 -- 516}, year = {2018}, abstract = {The UN sets the goal to ensure access to water and sanitation for all people by 2030. To address this goal, we present a multidisciplinary approach for designing water supply networks for slums in large cities by applying mathematical optimization. The problem is modeled as a mixed-integer linear problem (MILP) aiming to find a network describing the optimal supply infrastructure. To illustrate the approach, we apply it on a small slum cluster in Dhaka, Bangladesh.}, language = {en} } @article{RauschFriesenAltherretal.2018, author = {Rausch, Lea and Friesen, John and Altherr, Lena and Meck, Marvin and Pelz, Peter F.}, title = {A holistic concept to design optimal water supply infrastructures for informal settlements using remote sensing data}, series = {Remote Sensing}, volume = {10}, journal = {Remote Sensing}, number = {2}, publisher = {MDPI}, address = {Basel}, isbn = {2072-4292}, doi = {10.3390/rs10020216}, pages = {1 -- 23}, year = {2018}, abstract = {Ensuring access to water and sanitation for all is Goal No. 6 of the 17 UN Sustainability Development Goals to transform our world. As one step towards this goal, we present an approach that leverages remote sensing data to plan optimal water supply networks for informal urban settlements. The concept focuses on slums within large urban areas, which are often characterized by a lack of an appropriate water supply. We apply methods of mathematical optimization aiming to find a network describing the optimal supply infrastructure. Hereby, we choose between different decentral and central approaches combining supply by motorized vehicles with supply by pipe systems. For the purposes of illustration, we apply the approach to two small slum clusters in Dhaka and Dar es Salaam. We show our optimization results, which represent the lowest cost water supply systems possible. Additionally, we compare the optimal solutions of the two clusters (also for varying input parameters, such as population densities and slum size development over time) and describe how the result of the optimization depends on the entered remote sensing data.}, language = {en} } @article{RauppSchmittWalzetal.2018, author = {Raupp, Sebastian M. and Schmitt, Marcel and Walz, Anna-Lena and Diehm, Ralf and Hummel, Helga and Scharfer, Philip and Schabel, Wilhelm}, title = {Slot die stripe coating of low viscous fluids}, series = {Journal of Coatings Technology and Research}, volume = {15}, journal = {Journal of Coatings Technology and Research}, number = {5}, publisher = {Springer}, issn = {1935-3804}, doi = {10.1007/s11998-017-0039-y}, pages = {899 -- 911}, year = {2018}, abstract = {Slot die coating is applied to deposit thin and homogenous films in roll-to-roll and sheet-to-sheet applications. The critical step in operation is to choose suitable process parameters within the process window. In this work, we investigate an upper limit for stripe coatings. This maximum film thickness is characterized by stripe merging which needs to be avoided in a stable process. It is shown that the upper limit reduces the process window for stripe coatings to a major extent. As a result, stripe coatings at large coating gaps and low viscosities are only possible for relatively thick films. Explaining the upper limit, a theory of balancing the side pressure in the gap region in the cross-web direction has been developed.}, language = {en} } @inproceedings{RaupachOrlowskyBuettneretal.2006, author = {Raupach, Michael and Orlowsky, Jeannette and B{\"u}ttner, T. and Dilthey, Ulrich and Schleser, Markus}, title = {Epoxy-impregnated textiles in concrete - load bearing capacity and durability}, series = {Textile reinforced concrete : proceedings of the 1. International RILEM Conference, held at the RWTH Aachen, September 6/7, 2006. (RILEM proceedings ; 50)}, booktitle = {Textile reinforced concrete : proceedings of the 1. International RILEM Conference, held at the RWTH Aachen, September 6/7, 2006. (RILEM proceedings ; 50)}, editor = {Hegger, Josef}, publisher = {RILEM Publ.}, address = {Bagneux}, organization = {International Conference on Textile Reinforced Concrete <1, 2006, Aachen>}, isbn = {2-912143-97-7}, pages = {77 -- 88}, year = {2006}, language = {en} } @article{RaueWambachGloeggleretal.2014, author = {Raue, Markus and Wambach, M. and Gl{\"o}ggler, S. and Grefen, Dana and Kaufmann, R. and Abetz, C. and Georgopanos, P. and Handge, U. A. and Mang, Thomas and Bl{\"u}mich, B. and Abetz, V.}, title = {Investigation of historical hard rubber ornaments of Charles Goodyear}, series = {Macromolecular chemistry and physics}, volume = {Vol. 215}, journal = {Macromolecular chemistry and physics}, number = {No. 3}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1022-1352}, pages = {245 -- 254}, year = {2014}, language = {en} } @article{RauAlexopoulosBreitbachetal.2014, author = {Rau, Christoph and Alexopoulos, Spiros and Breitbach, Gerd and Hoffschmidt, Bernhard and Latzke, Markus and Sattler, Johannes Christoph}, title = {Transient simulation of a solar-hybrid tower power plant with open volumetric receiver at the location Barstow}, series = {Energy procedia : proceedings of the SolarPACES 2013 International Conference}, volume = {49}, journal = {Energy procedia : proceedings of the SolarPACES 2013 International Conference}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1876-6102}, doi = {10.1016/j.egypro.2014.03.157}, pages = {1481 -- 1490}, year = {2014}, abstract = {In this work the transient simulations of four hybrid solar tower power plant concepts with open-volumetric receiver technology for a location in Barstow-Daggett, USA, are presented. The open-volumetric receiver uses ambient air as heat transfer fluid and the hybridization is realized with a gas turbine. The Rankine cycle is heated by solar-heated air and/or by the gas turbine's flue gases. The plant can be operated in solar-only, hybrid parallel or combined cycle-only mode as well as in any intermediate load levels where the solar portion can vary between 0 to 100\%. The simulated plant is based on the configuration of a solar-hybrid power tower project, which is in planning for a site in Northern Algeria. The meteorological data for Barstow-Daggett was taken from the software meteonorm. The solar power tower simulation tool has been developed in the simulation environment MATLAB/Simulink and is validated.}, language = {en} } @article{RatkeMilowLisinskietal.2014, author = {Ratke, Lorenz and Milow, Barbara and Lisinski, Susanne and Hoepfner, Sandra}, title = {On an effect of fine ceramic particles on the structure of aerogels}, series = {Microgravity science and technology}, volume = {26}, journal = {Microgravity science and technology}, publisher = {Springer Nature}, address = {Heidelberg}, issn = {0938-0108 ; 1875-0494}, doi = {10.1007/s12217-014-9380-2}, pages = {103 -- 110}, year = {2014}, language = {en} } @book{RathDzierzynski1995, author = {Rath, Walter and Dzierzynski, Elmar}, title = {Solvent-free contact adhesive = L{\"o}sungsmittelfreier Kontaktklebstoff / Rath, Walter ; Dzierzynski, Elmar [Erfinder]}, publisher = {Europ{\"a}isches Patentamt}, address = {M{\"u}nchen}, year = {1995}, language = {en} } @article{RathMottaghy2007, author = {Rath, V. and Mottaghy, Darius}, title = {Smooth inversion for ground surface temperature histories: estimating the optimum regularization parameter by generalized cross-validation}, series = {Geophysical Journal International}, volume = {171}, journal = {Geophysical Journal International}, number = {3}, issn = {1365-246X}, doi = {10.1111/j.1365-246X.2007.03587.x}, pages = {1440 -- 1448}, year = {2007}, language = {en} } @article{RateikeWeyerWiedenmannetal.1981, author = {Rateike, Franz-Matthias and Weyer, K. G. and Wiedenmann, H. and MacGillivray, W. R.}, title = {Observation of absorptive optical bistability in a fabry-perot cavity containing multiple atomic beams / K. G. Weyer ; H. Wiedenmann ; M. Rateike ; W. R. Mac Gillivray ; P. Meystre ; H. Walther}, series = {Optics communications. 37 (1981), H. 6}, journal = {Optics communications. 37 (1981), H. 6}, isbn = {0030-4018}, pages = {426 -- 430}, year = {1981}, language = {en} } @article{RateikeSiebourgSchmidetal.1990, author = {Rateike, Franz-Matthias and Siebourg, W. and Schmid, H. and Anders, S.}, title = {Birefringence - An important property of plastic substrates for magneto-optical storage disks / W. Siebourg ; H. Schmid ; F. M. Rateike ; S. Anders ; U. Grigo ; H. L{\"o}wer}, series = {Polymer engineering \& science / Society of Plastics Engineers. 30 (1990), H. 18}, journal = {Polymer engineering \& science / Society of Plastics Engineers. 30 (1990), H. 18}, isbn = {0032-3888}, pages = {1133 -- 1139}, year = {1990}, language = {en} } @incollection{RaoPathroseHueningetal.2019, author = {Rao, Deepak and Pathrose, Plato and H{\"u}ning, Felix and Sid, Jithin}, title = {An Approach for Validating Safety of Perception Software in Autonomous Driving Systems}, series = {Model-Based Safety and Assessment: 6th International Symposium, IMBSA 2019, Thessaloniki, Greece, October 16-18, 2019, Proceedings}, booktitle = {Model-Based Safety and Assessment: 6th International Symposium, IMBSA 2019, Thessaloniki, Greece, October 16-18, 2019, Proceedings}, publisher = {Springer}, address = {Cham}, isbn = {978-3-030-32872-6}, doi = {10.1007/978-3-030-32872-6_20}, pages = {303 -- 316}, year = {2019}, abstract = {The increasing complexity of Advanced Driver Assistance Systems (ADAS) presents a challenging task to validate safe and reliable performance of these systems under varied conditions. The test and validation of ADAS/AD with real test drives, although important, involves huge costs and time. Simulation tools provide an alternative with the added advantage of reproducibility but often use ideal sensors, which do not reflect real sensor output accurately. This paper presents a new validation methodology using fault injection, as recommended by the ISO 26262 standard, to test software and system robustness. In our work, we investigated and developed a tool capable of inserting faults at different software and system levels to verify its robustness. The scope of this paper is to cover the fault injection test for the Visteon's DriveCore™ system, a centralized domain controller for Autonomous driving which is sensor agnostic and SoC agnostic. With this new approach, the validation of safety monitoring functionality and its behavior can be tested using real-world data instead of synthetic data from simulation tools resulting in having better confidence in system performance before proceeding with in-vehicle testing.}, language = {en} } @article{RamoshabaHuismanLammertynetal.2020, author = {Ramoshaba, Nthai E. and Huisman, Hugo W. and Lammertyn, Leandi and Kotliar, Konstantin and Schutte, Aletta E. and Smith, Wayne}, title = {Retinal microvasculature and masked hypertension in young adults: the African-PREDICT study}, series = {Hypertension Research}, journal = {Hypertension Research}, number = {43}, publisher = {Springer Nature}, address = {Osaka}, issn = {1348-4214}, doi = {10.1038/s41440-020-0487-0}, pages = {1231 -- 1238}, year = {2020}, abstract = {Masked hypertension is known to induce microvascular complications. However, it is unclear whether early microvascular changes are already occurring in young, otherwise healthy adults. We therefore investigated whether retinal microvascular calibers and acute responses to a flicker stimulus are related to masked hypertension. We used the baseline data of 889 participants aged 20-30 years who were taking part in the African Prospective study on the Early Detection and Identification of Cardiovascular Disease and Hypertension. Clinic and 24-h ambulatory blood pressure were measured. The central retinal artery equivalent (CRAE) and central retinal vein equivalent were calculated from fundus images, and retinal vessel dilation was determined in response to flicker light-induced provocation. A smaller CRAE was observed in those with masked hypertension vs. those with normotension (157.1 vs. 161.2 measuring units, P < 0.001). In forward multivariable-adjusted regression analysis, only CRAE was negatively related to masked hypertension [adjusted R² = 0.267, β = -0.097 (95\% CI = -0.165; -0.029), P = 0.005], but other retinal microvascular parameters were not associated with masked hypertension. In multivariable logistic regression analyses, masked hypertension [OR = 2.333, (95\% CI = 1.316; 4.241), P = 0.004] was associated with a narrower CRAE. In young healthy adults, masked hypertension was associated with retinal arteriolar narrowing, thereby reflecting early microvascular alterations known to predict cardiovascular outcomes in later life.}, language = {en} } @article{RamazaniLiMukherjeeetal.2013, author = {Ramazani, Ali and Li, Yang and Mukherjee, Krishnendu and Prahl, Ulrich and Bleck, Wolfgang and Abdurakhmanov, Aydemir and Schleser, Markus and Reisgen, Uwe}, title = {Microstructure evolution simulation in hot rolled DP600 steel during gas metal arc welding}, series = {Computational materials science}, volume = {Vol. 68}, journal = {Computational materials science}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-0801 (E-Book); 0927-0256 (Print)}, pages = {107 -- 116}, year = {2013}, language = {en} } @inproceedings{RamanJungHorvathetal.2019, author = {Raman, Aravind Hariharan and Jung, Alexander and Horv{\´a}th, Andr{\´a}s and Becker, Nadine and Staat, Manfred}, title = {Modification of a computer model of human stem cell-derived cardiomyocyte electrophysiology based on Patch-Clamp measurements}, series = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, booktitle = {3rd YRA MedTech Symposium 2019 : May 24 / 2019 / FH Aachen}, editor = {Staat, Manfred and Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-22-6}, doi = {10.17185/duepublico/48750}, pages = {10 -- 11}, year = {2019}, abstract = {Human induced pluripotent stem cells (hiPSCs) have shown to be promising in disease studies and drug screenings [1]. Cardiomyocytes derived from hiPSCs have been extensively investigated using patch-clamping and optical methods to compare their electromechanical behaviour relative to fully matured adult cells. Mathematical models can be used for translating findings on hiPSCCMs to adult cells [2] or to better understand the mechanisms of various ion channels when a drug is applied [3,4]. Paci et al. (2013) [3] developed the first model of hiPSC-CMs, which they later refined based on new data [3]. The model is based on iCells® (Fujifilm Cellular Dynamics, Inc. (FCDI), Madison WI, USA) but major differences among several cell lines and even within a single cell line have been found and motivate an approach for creating sample-specific models. We have developed an optimisation algorithm that parameterises the conductances (in S/F=Siemens/Farad) of the latest Paci et al. model (2018) [5] using current-voltage data obtained in individual patch-clamp experiments derived from an automated patch clamp system (Patchliner, Nanion Technologies GmbH, Munich).}, language = {en} } @inproceedings{RajanKubalskiAltayetal.2017, author = {Rajan, Sreelakshmy and Kubalski, Thomas and Altay, Okyay and Dalguer, Luis A and Butenweg, Christoph}, title = {Multi-dimensional fragility analysis of a RC building with components using response surface method}, series = {24th International Conference on Structural Mechanics in Reactor Technology, Busan, Korea, 20-25 August, 2017}, booktitle = {24th International Conference on Structural Mechanics in Reactor Technology, Busan, Korea, 20-25 August, 2017}, publisher = {International Assn for Structural Mechanics in Reactor Technology (IASMiRT)}, address = {Raleigh, USA}, isbn = {9781510856776}, pages = {3126 -- 3135}, year = {2017}, abstract = {Conventional fragility curves describe the vulnerability of the main structure under external hazards. However, in complex structures such as nuclear power plants, the safety or the risk depends also on the components associated with a system. The classical fault tree analysis gives an overall view of the failure and contains several subsystems to the main event, however, the interactions in the subsystems are not well represented. In order to represent the interaction of the components, a method suggested by Cimellaro et al. (2006) using multidimensional performance limit state functions to obtain the system fragility curves is adopted. This approach gives the possibility of deriving the cumulative fragility taking into account the interaction of the response of different components. In this paper, this approach is used to evaluate seismic risk of a representative electrical building infrastructure, including the component, of a nuclear power plant. A simplified model of the structure, with nonlinear material behavior is employed for the analysis in Abaqus©. The input variables considered are the material parameters, boundary conditions and the seismic input. The variability of the seismic input is obtained from selected ground motion time histories of spectrum compatible synthetic ccelerograms. Unlike the usual Monte Carlo methods used for the probabilistic analysis of the structure, a computationally effective response surface method is used. This method reduces the computational effort of the calculations by reducing the required number of samples.}, language = {en} } @inproceedings{RajanHoltschoppenDalgueretal.2016, author = {Rajan, Sreelakshmy and Holtschoppen, B. and Dalguer, L. A. and Klinkel, S. and Butenweg, Christoph}, title = {Seismic fragility analysis of a non-conventional reinforced concrete structure considering different uncertainties}, series = {Proceedings of ISMA2016, International Conference on Noise and Vibration Engineering/USD2016, International Conference on Uncertainty in Structural Dynamics, / ISMA 2016, USD 2016}, booktitle = {Proceedings of ISMA2016, International Conference on Noise and Vibration Engineering/USD2016, International Conference on Uncertainty in Structural Dynamics, / ISMA 2016, USD 2016}, editor = {Sas, P.}, publisher = {KU Leuven}, address = {Leuven}, pages = {4213 -- 4225}, year = {2016}, language = {en} } @inproceedings{RajanButenwegDalgueretal.2017, author = {Rajan, S. and Butenweg, Christoph and Dalguer, L. A. and An, J. H. and Renault, P. and Klinkel, S.}, title = {Fragility curves for a three-storey reinforced concrete test structure of the international benchmark SMART 2013}, series = {16th World Conference on Earthquake, 16WCEE 2017 Santiago Chile, January 9th to 13th 2017}, booktitle = {16th World Conference on Earthquake, 16WCEE 2017 Santiago Chile, January 9th to 13th 2017}, publisher = {Chilean Association on Seismology and Earthquake Engineering (ACHISINA)}, year = {2017}, language = {en} }