@article{FleischhakerEversDey2010, author = {Fleischhaker, Robert and Evers, J{\"o}rg and Dey, Tarak N.}, title = {Phase modulation induced by cooperative effects in electromagnetically induced transparency}, series = {Physical Review A - Atomic, molecular, and optical physics}, volume = {82}, journal = {Physical Review A - Atomic, molecular, and optical physics}, number = {1}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {1050-2947}, doi = {10.1103/PhysRevA.82.013815}, pages = {013815}, year = {2010}, abstract = {We analyze the influence of dipole-dipole interactions in an electromagnetically induced transparency set up for a density at the onset of cooperative effects. To this end, we include mean-field models for the influence of local-field corrections and radiation trapping into our calculation. We show both analytically and numerically that the polarization contribution to the local field strongly modulates the phase of a weak pulse. We give an intuitive explanation for this local-field-induced phase modulation and demonstrate that it distinctively differs from the nonlinear self-phase-modulation that a strong pulse experiences in a Kerr medium.}, language = {en} } @article{FleischhakerEvers2011, author = {Fleischhaker, Robert and Evers, J{\"o}rg}, title = {A Maxwell-Schr{\"o}dinger solver for quantum optical few-level systems}, series = {Computer Physics Communications}, volume = {182}, journal = {Computer Physics Communications}, number = {3}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0010-4655}, doi = {10.1016/j.cpc.2010.10.018}, pages = {739 -- 747}, year = {2011}, abstract = {The msprop program presented in this work is capable of solving the Maxwell-Schr{\"o}dinger equations for one or several laser fields propagating through a medium of quantum optical few-level systems in one spatial dimension and in time. In particular, it allows to numerically treat systems in which a laser field interacts with the medium with both its electric and magnetic component at the same time. The internal dynamics of the few-level system is modeled by a quantum optical master equation which includes coherent processes due to optical transitions driven by the laser fields as well as incoherent processes due to decay and dephasing. The propagation dynamics of the laser fields is treated in slowly varying envelope approximation resulting in a first order wave equation for each laser field envelope function. The program employs an Adams predictor formula second order in time to integrate the quantum optical master equation and a Lax-Wendroff scheme second order in space and time to evolve the wave equations for the fields. The source function in the Lax-Wendroff scheme is specifically adapted to allow taking into account the simultaneous coupling of a laser field to the polarization and the magnetization of the medium. To reduce execution time, a customized data structure is implemented and explained. In three examples the features of the program are demonstrated and the treatment of a system with a phase-dependent cross coupling of the electric and magnetic field component of a laser field is shown.}, language = {en} } @article{FleischhakerKraussSchaettigeretal.2013, author = {Fleischhaker, Robert and Krauß, Nico and Sch{\"a}ttiger, Farina and Dekorsy, Thomas}, title = {Consistent characterization of semiconductor saturable absorber mirrors with singe-pulse and pump-probe spectroscopy}, series = {Optics Express}, volume = {21}, journal = {Optics Express}, number = {6}, publisher = {Optica}, address = {Washington, DC}, issn = {1094-4087}, doi = {10.1364/OE.21.006764}, pages = {6764 -- 6776}, year = {2013}, language = {en} } @inproceedings{FleischhakerGebsBudnickietal.2013, author = {Fleischhaker, Robert and Gebs, Raphael and Budnicki, Aleksander and Wolf, M. and Kleinbauer, Jochen and Sutter, Dirk H.}, title = {Compact gigawatt-class sub-picosecond Yb:YAG thin-disk regenerative chirped-pulse amplifier with high average power at up to 800 kHz}, series = {Lasers and electro-optics europe (CLEO EUROPE/IQEC) : International quantum electronics conference : 12 - 16 May 2013, Munich, GE.}, booktitle = {Lasers and electro-optics europe (CLEO EUROPE/IQEC) : International quantum electronics conference : 12 - 16 May 2013, Munich, GE.}, publisher = {IEEE Computer Society}, isbn = {978-1-4799-0593-5}, doi = {10.1109/CLEOE-IQEC.2013.6801054}, pages = {1}, year = {2013}, language = {en} } @inproceedings{HecklWeilerFleischhakeretal.2014, author = {Heckl, O. H. and Weiler, Sascha and Fleischhaker, Robert and Gebs, Raphael and Budnicki, Aleksander and Wolf, M. and Kleinbauer, Jochen and Russ, S. and Kumkar, M. and Sutter, Dirk H.}, title = {Industry-grade high average power femtosecond light source}, series = {Frontiers in ultrafast optics: Biomedical, scientific, and industrial applications XIV : 1 Februar 2014, San Francisco, USA. - (SPIE proceedings series ; 8972)}, booktitle = {Frontiers in ultrafast optics: Biomedical, scientific, and industrial applications XIV : 1 Februar 2014, San Francisco, USA. - (SPIE proceedings series ; 8972)}, editor = {Heisterkamp, Alexander and Herman, Peter R. and Meunier, Michael and Nolte, Stefan}, publisher = {SPIE, International Society for Optical Engineering}, doi = {10.1117/12.2039337}, pages = {89720P -- 89720P-7}, year = {2014}, language = {en} } @inproceedings{PrickingGebsFleischhakeretal.2015, author = {Pricking, Sebastian and Gebs, Raphael and Fleischhaker, Robert and Kleinbauer, Jochen and Budnicki, Aleksander and Sutter, Dirk and Killi, Alexander and Weiler, Sascha and Mielke, M. and Beaudou, B. and Debord, B. and Gerome, F. and Benabid, F.}, title = {Hollow core fiber delivery of sub-ps pulses from a TruMicro 5000 Femto edition thin disk amplifier}, series = {High-power laser materials processing: Lasers, beam delivery, diagnostics, and applications IV : 7 Februar 2015, San Francisco, USA. - (SPIE proceedings series ; 9356)}, booktitle = {High-power laser materials processing: Lasers, beam delivery, diagnostics, and applications IV : 7 Februar 2015, San Francisco, USA. - (SPIE proceedings series ; 9356)}, editor = {Dorsch, Friedhelm}, publisher = {SPIE, International Society for Optical Engineering}, organization = {The international society for optical engineering, SPIE <2, 2015, San Francisco, CA>}, isbn = {978-162841446-2}, issn = {0277-786X}, doi = {10.1117/12.2079289}, pages = {935602}, year = {2015}, language = {en} } @article{MahmoudiFleischhakerSahraietal.2008, author = {Mahmoudi, Mohammad and Fleischhaker, Robert and Sahrai, Mostafa and Evers, J{\"o}rg}, title = {Group velocity control in the ultraviolet domain via interacting dark-state resonances}, series = {Journal of physics B: Atomic, molecular and optical physics}, volume = {41}, journal = {Journal of physics B: Atomic, molecular and optical physics}, number = {2}, issn = {0953-4075}, doi = {10.1088/0953-4075/41/2/025504}, pages = {25504 -- 25600}, year = {2008}, language = {en} } @inproceedings{Huening2016, author = {H{\"u}ning, Felix}, title = {Power Semiconductors for the automotive 48V board net}, series = {PCIM Europe 2016 Conference Proceedings}, booktitle = {PCIM Europe 2016 Conference Proceedings}, publisher = {VDE Verl.}, address = {Berlin}, isbn = {978-3-8007-4186-1}, pages = {1963 -- 1969}, year = {2016}, language = {en} } @inproceedings{SchreiberKraftZuendorf2016, author = {Schreiber, Marc and Kraft, Bodo and Z{\"u}ndorf, Albert}, title = {Cost-efficient quality assurance of natural language processing tools through continuous monitoring with continuous integration}, series = {3rd International Workshop on Software Engineering Research and Industrial Practice}, booktitle = {3rd International Workshop on Software Engineering Research and Industrial Practice}, doi = {10.1145/2897022.2897029}, pages = {46 -- 52}, year = {2016}, language = {en} } @article{WegmannHacklStaatetal.2016, author = {Wegmann, Kilian and Hackl, Michael and Staat, Manfred and Mayer, Katharina and M{\"u}ller, Lars-Peter}, title = {Double plate osteosynthesis of proximal ulna fractures: biomechanical and clinical results}, series = {Knee surgery, sports traumatology, arthroscopy}, volume = {Volume 24}, journal = {Knee surgery, sports traumatology, arthroscopy}, number = {Supplement 1}, publisher = {Springer}, address = {Berlin}, issn = {0942-2056}, doi = {10.1007/s00167-016-4079-0}, pages = {58 -- 59}, year = {2016}, abstract = {While plate fixation of proximal ulna fractures might lead to superior clinical results compared to tension band wiring, regular plates represent an established risk factor for wound complications. The olecranon double plates (Medartis, Basel, CH) might decrease complications related to the osteosynthesis because of their low profile and better anatomical fit. This study aimed to evaluate the biomechanical performance and clinical results of the olecranon double plates.}, language = {en} } @article{HacklLeschingerStaatetal.2016, author = {Hackl, Michael and Leschinger, T. and Staat, Manfred and M{\"u}ller, Lars-Peter and Wegmann, Kilian}, title = {Reconstruction of the interosseous membrane in the Essex Lopresti lesion — a biomechanical evaluation}, series = {Knee surgery, sports traumatology, arthroscopy}, volume = {Volume 24}, journal = {Knee surgery, sports traumatology, arthroscopy}, number = {Supplement 1}, publisher = {Springer}, address = {Berlin}, issn = {0942-2056}, doi = {10.1007/s00167-016-4080-7}, pages = {130 -- 131}, year = {2016}, abstract = {Surgical reconstruction of the interosseous membrane (IOM) could restore longitudinal forearm stability to avoid persisting disability due to capituloradial and ulnocarpal impingement in Essex Lopresti lesions. This biomechanical study aimed to assess longitudinal forearm stability of intact specimens, after sectioning of the IOM and after reconstruction with a TightRope construct using either a single or double bundle technique.}, language = {en} } @article{HacklKahmannWegmannetal.2016, author = {Hackl, Michael and Kahmann, Stephanie Lucina and Wegmann, Kilian and Ries, Christian and Staat, Manfred and M{\"u}ller, Lars-Peter}, title = {Shortening osteotomy of the proximal radius — a treatment option for isolated osteoarthritis of the lateral column of the elbow joint?}, series = {Knee surgery, sports traumatology, arthroscopy}, volume = {Volume 24}, journal = {Knee surgery, sports traumatology, arthroscopy}, number = {Supplement 1}, publisher = {Springer}, address = {Berlin}, issn = {0942-2056}, doi = {10.1007/s00167-016-4080-7}, pages = {128 -- 129}, year = {2016}, abstract = {Treatment of posttraumatic osteoarthritis of the radial column of the elbow joint remains a challenging yet common issue. While partial joint replacement leads to high revision rates, radial head excision has shown to severely increase joint instability. Shortening osteotomy of the radius could be an option to decrease the contact pressure of the radiohumeral joint and thereby pain levels without causing valgus instability. Hence, the aim of this biomechanical study was to evaluate the effects of radial shortening on axial load distribution and valgus stability of the elbow joint.}, language = {en} } @article{HacklMuellerStaatetal.2016, author = {Hackl, Michael and M{\"u}ller, Lars-Peter and Staat, Manfred and Kahmann, Stephanie Lucina and Wegmann, Kilian}, title = {Proximal phalangeal neck fractures of the hand — a biomechanical comparison of three fixation techniques}, series = {Knee surgery, sports traumatology, arthroscopy}, volume = {Volume 24}, journal = {Knee surgery, sports traumatology, arthroscopy}, number = {Supplement 1}, publisher = {Springer}, address = {Berlin}, issn = {0942-2056}, doi = {10.1007/s00167-016-4080-7}, pages = {148 -- 149}, year = {2016}, abstract = {Plate osteosynthesis of displaced proximal phalangeal neck fractures of the hand allows early mobilization due to a stable internal fixation. Nevertheless, joint stiffness—because of soft tissue irritation—represents a common complication leading to high complication rates. Del Pinal et al. recently reported promising clinical results for a new, minimally invasive fixation technique with a cannulated headless intramedullary compression screw. Hence, the aim of this study was to compare plate fixation of proximal phalangeal neck fractures to less two less invasive techniques: Crossed k-wire fixation and intramedullary screw fixation. We hypothesized that these fixation techniques provide inferior stability when compared to plate osteosynthesis.}, language = {en} } @inproceedings{KasperSchiffelsKrafftetal.2016, author = {Kasper, Katharina and Schiffels, Johannes and Krafft, Simone and Kuperjans, Isabel and Elbers, Gereon and Selmer, Thorsten}, title = {Biogas Production on Demand Regulated by Butyric Acid Addition}, series = {IOP Conference Series: Earth and Environmental Science. Bd. 32}, volume = {32}, booktitle = {IOP Conference Series: Earth and Environmental Science. Bd. 32}, issn = {1755-1315}, doi = {10.1088/1755-1315/32/1/012009}, pages = {012009/1 -- 012009/4}, year = {2016}, language = {en} } @inproceedings{StollenwerkRiekeDahmenetal.2016, author = {Stollenwerk, Dominik and Rieke, Christian and Dahmen, Markus and Pieper, Martin}, title = {Biogas Production Modelling : A Control System Engineering Approach}, series = {IOP Conference Series: Earth and Environmental Science. Bd. 32}, booktitle = {IOP Conference Series: Earth and Environmental Science. Bd. 32}, issn = {1755-1315}, doi = {10.1088/1755-1315/32/1/012008}, pages = {012008/1 -- 012008/4}, year = {2016}, language = {en} } @book{GebhardtHoetter2016, author = {Gebhardt, Andreas and H{\"o}tter, Jan-Steffen}, title = {Additive manufacturing : 3D printing for prototyping and manufacturing}, publisher = {Hanser Publishers}, address = {Munich}, isbn = {978-1-56990-582-1 ; 978-1-56990-583-8}, pages = {591 S.}, year = {2016}, language = {en} } @inproceedings{KahmannHacklWegmannetal.2016, author = {Kahmann, Stephanie and Hackl, Michael and Wegmann, Kilian and M{\"u}ller, Lars-Peter and Staat, Manfred}, title = {Impact of a proximal radial shortening osteotomy on the distribution of forces and the stability of the elbow}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {7 -- 8}, year = {2016}, abstract = {The human arm consists of the humerus (upper arm), the medial ulna and the lateral radius (forearm). The joint between the humerus and the ulna is called humeroulnar joint and the joint between the humerus and the radius is called humeroradial joint. Lateral and medial collateral ligaments stabilize the elbow. Statistically, 2.5 out of 10,000 people suffer from radial head fractures [1]. In these fractures the cartilage is often affected. Caused by the injured cartilage, degenerative diseases like posttraumatic arthrosis may occur. The resulting pain and reduced range of motion have an impact on the patient's quality of life. Until now, there has not been a treatment which allows typical loads in daily life activities and offers good long-term results. A new surgical approach was developed with the motivation to reduce the progress of the posttraumatic arthrosis. Here, the radius is shortened by 3 mm in the proximal part [2]. By this means, the load of the radius is intended to be reduced due to a load shift to the ulna. Since the radius is the most important stabilizer of the elbow it has to be confirmed that the stability is not affected. In the first test (Fig. 1 left), pressure distributions within the humeroulnar and humeroradial joints a native and a shortened radius were measured using resistive pressure sensors (I5076 and I5027, Tekscan, USA). The humerus was loaded axially in a tension testing machine (Z010, Zwick Roell, Germany) in 50 N steps up to 400 N. From the humerus the load is transmitted through both the radius and the ulna into the hand which is fixed on the ground. In the second test (Fig. 1 right), the joint stability was investigated using a digital image correlation system to measure the displacement of the ulna. Here, the humerus is fixed with a desired flexion angle and the unconstrained forearm lies on the ground. A rope connects the load actuator with a hook fixed in the ulna. A guide roller is used so that the rope pulls the ulna horizontally when a tensile load is applied. This creates a moment about the elbow joint with a maximum value of 7.5 Nm. Measurements were performed with varying flexion angles (0°, 30°, 60°, 90°, 120°). For both tests and each measurement, seven specimens were used. Student's t-test was employed to determine whether the mean values of the measurements in native specimen and operated specimens differ significantly.}, language = {en} } @inproceedings{JungStaat2016, author = {Jung, Alexander and Staat, Manfred}, title = {Computing olympic gold: Ski jumping as an example}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, isbn = {978-3-940402-06-6}, doi = {10.17185/duepublico/40821}, pages = {54 -- 55}, year = {2016}, language = {en} } @inproceedings{BhattaraiStaat2016, author = {Bhattarai, Aroj and Staat, Manfred}, title = {Female pelvic floor dysfunction: progress weakening of the support system}, series = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, booktitle = {1st YRA MedTech Symposium 2016 : April 8th / 2016 / University of Duisburg-Essen}, editor = {Erni, Daniel}, publisher = {Universit{\"a}t Duisburg-Essen}, address = {Duisburg}, organization = {MedTech Symposium}, doi = {10.17185/duepublico/40821}, pages = {11 -- 12}, year = {2016}, abstract = {The structure of the female pelvic floor (PF) is an inter-related system of bony pelvis,muscles, pelvic organs, fascias, ligaments, and nerves with multiple functions. Mechanically, thepelvic organ support system are of two types: (I) supporting system of the levator ani (LA) muscle,and (II) the suspension system of the endopelvic fascia condensation [1], [2]. Significantdenervation injury to the pelvic musculature, depolimerization of the collagen fibrils of the softvaginal hammock, cervical ring and ligaments during pregnancy and vaginal delivery weakens thenormal functions of the pelvic floor. Pelvic organ prolapse, incontinence, sexual dysfunction aresome of the dysfunctions which increases progressively with age and menopause due toweakened support system according to the Integral theory [3]. An improved 3D finite elementmodel of the female pelvic floor as shown in Fig. 1 is constructed that: (I) considers the realisticsupport of the organs to the pelvic side walls, (II) employs the improvement of our previous FEmodel [4], [5] along with the patient based geometries, (III) incorporates the realistic anatomy andboundary conditions of the endopelvic (pubocervical and rectovaginal) fascia, and (IV) considersvarying stiffness of the endopelvic fascia in the craniocaudal direction [3]. Several computationsare carried out on the presented computational model with healthy and damaged supportingtissues, and comparisons are made to understand the physiopathology of the female PF disorders.}, language = {en} } @article{PookhalilAmoabedinyTabeshetal.2016, author = {Pookhalil, Ali and Amoabediny, Ghassem and Tabesh, Hadi and Behbahani, Mehdi and Mottaghy, Khosrow}, title = {A new approach for semiempirical modeling of mechanical blood trauma}, series = {The international journal of artificial organs}, volume = {39}, journal = {The international journal of artificial organs}, number = {4}, publisher = {Sage}, address = {London}, issn = {1724-6040}, doi = {10.5301/ijao.5000474}, pages = {171 -- 177}, year = {2016}, abstract = {Purpose Two semi-empirical models were recently published, both making use of existing literature data, but each taking into account different physical phenomena that trigger hemolysis. In the first model, hemoglobin (Hb) release is described as a permeation procedure across the membrane, assuming a shear stress-dependent process (sublethal model). The second model only accounts for hemoglobin release that is caused by cell membrane breakdown, which occurs when red blood cells (RBC) undergo mechanically induced shearing for a period longer than the threshold time (nonuniform threshold model). In this paper, we introduce a model that considers the hemolysis generated by both these possible phenomena. Methods Since hemolysis can possibly be caused by permeation of hemoglobin through the RBC functional membrane as well as by release of hemoglobin from RBC membrane breakdown, our proposed model combines both these models. An experimental setup consisting of a Couette device was utilized for validation of our proposed model. Results A comparison is presented between the damage index (DI) predicted by the proposed model vs. the sublethal model vs. the nonthreshold model and experimental datasets. This comparison covers a wide range of shear stress for both human and porcine blood. An appropriate agreement between the measured DI and the DI predicted by the present model was obtained. Conclusions The semiempirical hemolysis model introduced in this paper aims for significantly enhanced conformity with experimental data. Two phenomenological outcomes become possible with the proposed approach: an estimation of the average time after which cell membrane breakdown occurs under the applied conditions, and a prediction of the ratio between the phenomena involved in hemolysis.}, language = {en} }