@inproceedings{SchoeningAbdelghani2012, author = {Sch{\"o}ning, Michael Josef and Abdelghani, Adnane}, title = {Nanoscale Science and Technology (NS\&T'12) : Proceedings Book Humboldt Kolleg <2012, Tunisia> ; Tunisia, 17-19 March, 2012 / ed. by Michael J. Sch{\"o}ning ; Adnane Abdelghani}, url = {http://nbn-resolving.de/urn:nbn:de:hbz:a96-opus-3544}, year = {2012}, abstract = {Proceedings of the 2nd Humboldt Kolleg, Hammamet, Tunisia Organizer: Alexander von Humboldt Stiftung, Germany. pdf 184 p. Welcome Address Dear Participants, Welcome to the 2nd Humboldt Kolleg in "Nanoscale Science and Technology" (NS\&T'12) in Tunisia, sponsored by the "Alexander von Humboldt" foundation. The NS\&T'12 multidisciplinary scientific program includes seven "hot" topics dealing with "Nanoscale Science and Technology" covering basic and application-oriented research as well as industrial (market) aspects: - Molecular Biophyics, Spectroscopy Techniques, Imaging Microscopy - Nanomaterials Synthesis for Medicine and Bio-chemical Sensors - Nanostructures, Semiconductors, Photonics and Nanodevices - New Technologies in Market Industry - Environment, Electro-chemistry, Bio-polymers and Fuel Cells - Nanomaterials, Photovoltaic, Modelling, Quantum Physics - Microelectronics, Sensors Networks and Embedded Systems We are deeply indebted to all members of the Scientific Committee and General Chairs for joint Sessions and to all speakers and chairmen, who have dedicated invaluable time and efforts for the realization of this event. On behalf of the Organizing Committee, we are cordially inviting you to join the conference and hope that your stay will be fruitful, rewarding and enjoyable. Prof. Dr. Michael J. Sch{\"o}ning, Prof. Dr. Adnane Abdelghani}, subject = {Biosensor}, language = {en} } @article{WernerWagnerMiyamotoetal.2012, author = {Werner, Frederik and Wagner, Torsten and Miyamoto, Ko-ichiro and Yoshinobu, Tatsuo and Sch{\"o}ning, Michael Josef}, title = {High speed and high resolution chemical imaging based on a new type of OLED-LAPS set-up}, series = {Sensors and Actuators B: Chemical}, volume = {175}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.12.102}, pages = {118 -- 122}, year = {2012}, abstract = {Light-addressable potentiometric sensors (LAPS) are field-effect-based sensors. A modulated light source is used to define the particular measurement spot to perform spatially resolved measurements of chemical species and to generate chemical images. In this work, an organic-LED (OLED) display has been chosen as a light source. This allows high measurement resolution and miniaturisation of the system. A new developed driving method for the OLED display optimised for LAPS-based measurements is demonstrated. The new method enables to define modulation frequencies between 1 kHz and 16 kHz and hence, reduces the measurement time of a chemical image by a factor of 40 compared to the traditional addressing of an OLED display.}, language = {en} } @article{WagnerWernerMiyamotoetal.2012, author = {Wagner, Torsten and Werner, Frederik and Miyamoto, Ko-Ichiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Development and characterisation of a compact light-addressable potentiometric sensor (LAPS) based on the digital light processing (DLP) technology for flexible chemical imaging}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2010.12.003}, pages = {34 -- 39}, year = {2012}, abstract = {Chemical imaging systems allow the visualisation of the distribution of chemical species on the sensor surface. This work represents a new flexible approach to read out light-addressable potentiometric sensors (LAPS) with the help of a digital light processing (DLP) set-up. The DLP, known well for video projectors, consists of a mirror-array MEMS device, which allows fast and flexible generation of light patterns. With the help of these light patterns, the sensor surface of the LAPS device can be addressed. The DLP approach has several advantages compared to conventional LAPS set-ups, e.g., the spot size and the shape of the light pointer can be changed easily and no mechanical movement is necessary, which reduces the size of the set-up and increases the stability and speed of the measurement. In addition, the modulation frequency and intensity of the light beam are important parameters of the LAPS set-up. Within this work, the authors will discuss two different ways of light modulation by the DLP set-up, investigate the influence of different modulation frequencies and different light intensities as well as demonstrate the scanning capabilities of the new set-up by pH mapping on the sensor surface.}, language = {en} } @article{AggarwalDhimanKumaretal.2012, author = {Aggarwal, P. and Dhiman, S. and Kumar, G. and Scherer, Ulrich W. and Singla, M. L. and Srivastava, A.}, title = {Optical study of poly(ethyleneterephthalate) modified by different ionizing radiation dose}, series = {Indian Journal of Pure and Applied Physics}, volume = {50}, journal = {Indian Journal of Pure and Applied Physics}, number = {2}, issn = {0019-5596}, pages = {129 -- 132}, year = {2012}, abstract = {Thin films of poly(ethyleneterephthalate) [PET]were exposed to radiation dose ranging from 10 to 30 kGy by using gamma rays in the range 12.8-177.8 MGy using swift light ions of hydrogen. There was no effect of the radiation dose on the optical behaviour of PET as a result of exposure to radiation dose up to 30 kGy brought about by gamma rays but a significant decrease in the optical band gap values was observed when PET was exposed to swift light ions of hydrogen. The data obtained are discussed in terms of optical studies carried out on PET using swift heavy ions.}, language = {en} } @article{MiyamotoKanekoMatsuoetal.2012, author = {Miyamoto, Ko-ichiro and Kaneko, Kazumi and Matsuo, Akira and Wagner, Torsten and Kanoh, Shin{\´i}chiro and Sch{\"o}ning, Michael Josef and Yoshinobu, Tatsuo}, title = {Miniaturized chemical imaging sensor system using an OLED display panel}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.02.029}, pages = {82 -- 87}, year = {2012}, abstract = {The chemical imaging sensor is a semiconductor-based chemical sensor that can visualize the two-dimensional distribution of specific ions or molecules in the solution. In this study, we developed a miniaturized chemical imaging sensor system with an OLED display panel as a light source that scans the sensor plate. In the proposed configuration, the display panel is placed directly below the sensor plate and illuminates the back surface. The measured area defined by illumination can be arbitrarily customized to fit the size and the shape of the sample to be measured. The waveform of the generated photocurrent, the current-voltage characteristics and the pH sensitivity were investigated and pH imaging with this miniaturized system was demonstrated.}, language = {en} } @article{KirchnerOberlaenderFriedrichetal.2012, author = {Kirchner, Patrick and Oberl{\"a}nder, Jan and Friedrich, Peter and Berger, J{\"o}rg and Rysstad, Gunnar and Sch{\"o}ning, Michael Josef and Keusgen, Michael}, title = {Realisation of a calorimetric gas sensor on polyimide foil for applications in aseptic food industry}, series = {Sensors and Actuators B: Chemical}, volume = {170}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2011.01.032}, pages = {60 -- 66}, year = {2012}, abstract = {A calorimetric gas sensor is presented for the monitoring of vapour-phase H2O2 at elevated temperature during sterilisation processes in aseptic food industry. The sensor was built up on a flexible polyimide foil (thickness: 25 μm) that has been chosen due to its thermal stability and low thermal conductivity. The sensor set-up consists of two temperature-sensitive platinum thin-film resistances passivated by a layer of SU-8 photo resist and catalytically activated by manganese(IV) oxide. Instead of an active heating structure, the calorimetric sensor utilises the elevated temperature of the evaporated H2O2 aerosol. In an experimental test rig, the sensor has shown a sensitivity of 4.78 °C/(\%, v/v) in a H2O2 concentration range of 0\%, v/v to 8\%, v/v. Furthermore, the sensor possesses the same, unchanged sensor signal even at varied medium temperatures between 210 °C and 270 °C of the gas stream. At flow rates of the gas stream from 8 m3/h to 12 m3/h, the sensor has shown only a slightly reduced sensitivity at a low flow rate of 8 m3/h. The sensor characterisation demonstrates the suitability of the calorimetric gas sensor for monitoring the efficiency of industrial sterilisation processes.}, language = {en} } @article{AtlasBrealeyDharetal.2012, author = {Atlas, Glen and Brealey, David and Dhar, Sunil and Dikta, Gerhard and Singer, Meryvn}, title = {Additional hemodynamic measurements with an esophageal Doppler monitor: a preliminary report of compliance, force, kinetic energy, and afterload in the clinical setting}, series = {Journal of clinical monitoring and computing}, journal = {Journal of clinical monitoring and computing}, number = {26}, publisher = {Springer Nature}, address = {London}, isbn = {1573-2614}, doi = {10.1007/s10877-012-9386-5}, pages = {473 -- 482}, year = {2012}, abstract = {The esophageal Doppler monitor (EDM) is a minimally-invasive hemodynamic device which evaluates both cardiac output (CO), and fluid status, by estimating stroke volume (SV) and calculating heart rate (HR). The measurement of these parameters is based upon a continuous and accurate approximation of distal thoracic aortic blood flow. Furthermore, the peak velocity (PV) and mean acceleration (MA), of aortic blood flow at this anatomic location, are also determined by the EDM. The purpose of this preliminary report is to examine additional clinical hemodynamic calculations of: compliance (C), kinetic energy (KE), force (F), and afterload (TSVRi). These data were derived using both velocity-based measurements, provided by the EDM, as well as other contemporaneous physiologic parameters. Data were obtained from anesthetized patients undergoing surgery or who were in a critical care unit. A graphical inspection of these measurements is presented and discussed with respect to each patient's clinical situation. When normalized to each of their initial values, F and KE both consistently demonstrated more discriminative power than either PV or MA. The EDM offers additional applications for hemodynamic monitoring. Further research regarding the accuracy, utility, and limitations of these parameters is therefore indicated.}, language = {en} } @article{IkenKirsanovLeginetal.2012, author = {Iken, Heiko and Kirsanov, D. and Legin, A. and Sch{\"o}ning, Michael Josef}, title = {Novel Thin-Film Polymeric Materials for the Detection of Heavy Metals}, series = {Procedia Engineering}, journal = {Procedia Engineering}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2012.09.148}, pages = {322 -- 325}, year = {2012}, abstract = {A variety of transition metals, e.g., copper, zinc, cadmium, lead, etc. are widely used in industry as components for wires, coatings, alloys, batteries, paints and so on. The inevitable presence of transition metals in industrial processes implies the ambition of developing a proper analytical technique for their adequate monitoring. Most of these elements, especially lead and cadmium, are acutely toxic for biological organisms. Quantitative determination of these metals at low activity levels in different environmental and industrial samples is therefore a vital task. A promising approach to achieve an at-side or on-line monitoring on a miniaturized and cost efficient way is the combination of a common potentiometric sensor array with heavy metal-sensitive thin-film materials, like chalcogenide glasses and polymeric materials, respectively.}, language = {en} } @article{MiyamotoIchimuraWagneretal.2012, author = {Miyamoto, K. and Ichimura, H. and Wagner, Torsten and Yoshinobu, T. and Sch{\"o}ning, Michael Josef}, title = {Chemical Imaging of ion Diffusion in a Microfluidic Channel}, series = {Procedia Engineering}, journal = {Procedia Engineering}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2012.09.289}, pages = {886 -- 889}, year = {2012}, abstract = {The chemical imaging sensor is a chemical sensor which is capable of visualizing the spatial distribution of chemical species in sample solution. In this study, a novel measurement system based on the chemical imaging sensor was developed to observe the inside of a Y-shaped microfluidic channel while injecting two sample solutions from two branches. From the collected chemical images, it was clearly observed that the injected solutions formed laminar flows in the microfluidic channel. In addition, ion diffusion across the laminar flows was observed. This label-free method can acquire quantitative data of ion distribution and diffusion in microfluidic devices, which can be used to determine the diffusion coefficients, and therefore, the molecular weights of chemical species in the sample solution.}, language = {en} } @article{WagnerShigiaharaMiyamotoetal.2012, author = {Wagner, Torsten and Shigiahara, N. and Miyamoto, K. and Suzurikawa, J. and Finger, F. and Sch{\"o}ning, Michael Josef and Yoshinobu, T.}, title = {Light-addressable Potentiometric Sensors and Light-addressable Electrodes as a Combined Sensor-and-manipulator Microsystem with High Flexibility}, series = {Procedia Engineering}, journal = {Procedia Engineering}, number = {47}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1877-7058}, doi = {10.1016/j.proeng.2012.09.290}, pages = {890 -- 893}, year = {2012}, abstract = {This work describes the novel combination of the light-addressable electrode (LAE) and the light-addressable potentiometric sensor (LAPS) into a microsystem set-up. Both the LAE as well as the LAPS shares the principle of addressing the active spot by means of a light beam. This enables both systems to manipulate resp. to detect an analyte with a high spatial resolution. Hence, combining both principles into a single set-up enables the active stimulation e.g., by means of electrolysis and a simultaneous observation e.g., the response of an entrapped biological cell by detection of extracellular pH changes. The work will describe the principles of both technologies and the necessary steps to integrate them into a single set-up. Furthermore, examples of application and operation of such systems will be presented.}, language = {en} } @article{MuribTranCeunincketal.2012, author = {Murib, Mohammed S. and Tran, Anh Quang and Ceuninck, Ward de and Sch{\"o}ning, Michael Josef and Nesladek, Milos and Serpeng{\"u}zel, Ali and Wagner, Patrick}, title = {Analysis of an optical biosensor based on elastic light scattering from diamond-, glass-, and sapphire microspheres}, series = {Physica Status Solidi A}, volume = {209}, journal = {Physica Status Solidi A}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100795}, pages = {1804 -- 1810}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{LogenHoefkenSchuba2012, author = {Logen, Steffen and H{\"o}fken, Hans and Schuba, Marko}, title = {Simplifying RAM Forensics : A GUI and Extensions for the Volatility Framework}, series = {2012 Seventh International Conference on Availability, Reliability and Security (ARES), 20-24 August 2012, Prague, Czech Republic}, booktitle = {2012 Seventh International Conference on Availability, Reliability and Security (ARES), 20-24 August 2012, Prague, Czech Republic}, publisher = {IEEE}, address = {New York}, isbn = {978-1-4673-2244-7}, doi = {10.1109/ARES.2012.12}, pages = {620 -- 624}, year = {2012}, abstract = {The Volatility Framework is a collection of tools for the analysis of computer RAM. The framework offers a multitude of analysis options and is used by many investigators worldwide. Volatility currently comes with a command line interface only, which might be a hinderer for some investigators to use the tool. In this paper we present a GUI and extensions for the Volatility Framework, which on the one hand simplify the usage of the tool and on the other hand offer additional functionality like storage of results in a database, shortcuts for long Volatility Framework command sequences, and entirely new commands based on correlation of data stored in the database.}, language = {en} } @book{Grotendorst2012, author = {Grotendorst, Johannes}, title = {Hierarchical methods for dynamics in complex molecular systems : IAS Winter School, 5 - 9 March 2012, Forschungszentrum J{\"u}lich GmbH ; lecture notes / ed. by Johannes Grotendorst, Godehard Sutmann, Gerhard Gompper, Dominik Marx}, publisher = {Forschungszentrum J{\"u}lich}, address = {J{\"u}lich}, isbn = {978-3-89336-768-9}, pages = {VI, 540 S. zahlr. Ill. u. graph. Darst.}, year = {2012}, language = {en} } @article{GutheilBergGrotendorst2012, author = {Gutheil, Inge and Berg, Tommy and Grotendorst, Johannes}, title = {Performance Analysis of Parallel Eigensolvers of two Libraries on BlueGene/P}, series = {Journal of Mathematics and Systems Science}, volume = {2}, journal = {Journal of Mathematics and Systems Science}, number = {4}, publisher = {David Publishing}, address = {Libertyville}, issn = {2159-5291}, doi = {10.17265/2159-5291/2012.04.003}, pages = {231 -- 236}, year = {2012}, abstract = {Many applications in computational science and engineering require the computation of eigenvalues and vectors of dense symmetric or Hermitian matrices. For example, in DFT (density functional theory) calculations on modern supercomputers 10\% to 30\% of the eigenvalues and eigenvectors of huge dense matrices have to be calculated. Therefore, performance and parallel scaling of the used eigensolvers is of upmost interest. In this article different routines of the linear algebra packages ScaLAPACK and Elemental for parallel solution of the symmetric eigenvalue problem are compared concerning their performance on the BlueGene/P supercomputer. Parameters for performance optimization are adjusted for the different data distribution methods used in the two libraries. It is found that for all test cases the new library Elemental which uses a two-dimensional element by element distribution of the matrices to the processors shows better performance than the old ScaLAPACK library which uses a block-cyclic distribution.}, language = {en} } @article{Grotendorst2012, author = {Grotendorst, Johannes}, title = {IAS Winter School: Hierarchical Methods for Dynamics in Complex Molecular Systems}, series = {Innovatives Supercomputing in Deutschland : inSiDE. 10 (2012), H. 1}, journal = {Innovatives Supercomputing in Deutschland : inSiDE. 10 (2012), H. 1}, publisher = {-}, pages = {104}, year = {2012}, language = {en} } @article{NomdedeuWillenSchiefferetal.2012, author = {Nomdedeu, Mar Monsonis and Willen, Christine and Schieffer, Andre and Arndt, Hartmut}, title = {Temperature-dependent ranges of coexistence in a model of a two-prey-one-predator microbial food web}, series = {Marine Biology}, volume = {159}, journal = {Marine Biology}, number = {11}, publisher = {Springer}, address = {Berlin}, issn = {1432-1793}, doi = {10.1007/s00227-012-1966-x}, pages = {2423 -- 2430}, year = {2012}, abstract = {The objective of our study was to analyze the effects of temperature on the population dynamics of a three-species food web consisting of two prey bacteria (Pedobacter sp. and Acinetobacter johnsonii) and a protozoan predator (Tetrahymena pyriformis) as model organisms. We assessed the effects of temperature on the growth rates of all three species with the objective of developing a model with four differential equations based on the experimental data. The following hypotheses were tested at a theoretical level: Firstly, temperature changes can affect the dynamic behavior of a system by temperature-dependent parameters and interactions and secondly, food web response to temperature cannot be derived from the single species temperature response. The main outcome of the study is that temperature changes affect the parameter range where coexistence is possible within all three species. This has significant consequences on our ideas regarding the evaluation of effects of global warming.}, language = {en} } @phdthesis{Schieffer2012, author = {Schieffer, Andre}, title = {Studies on diversity and coexistence in an experimental microbial community}, pages = {76 Bl. : Ill.}, year = {2012}, abstract = {Biodiversity and the coexistence of species have puzzled and fascinated biologists since decades and is a hotspot in todays' natural sciences. Preserving this biodiversity is a great challenge as habitats and environments underlying tremendous changes like climate change and the loss of natural habitats, which are mainly due to anthropogenic influences. The coexistence of numerous species even in homogeneous environments is a stunning feature of natural communities and has been summarized under the term 'paradox of plankton'. Up to now, there are several mechanisms discussed, which may contribute to local and global diversity of organisms. Several interspecific trade offs have been identified maintaining the coexistence of species like their abilities regarding competition and predator avoidance, their capability to disperse in space and time, and their ability to exploit variable resources. Further, micro-evolutionary dynamics supporting the coexistence of species have been added to our knowledge, and deriving from theoretical deterministic models, non-linear dynamics which describe the temporal fluctuation of abundances of organisms. Whereas competition and predation seem to be clue structural elements within interacting organisms, the intrinsic dynamic behavior - by means of temporal changes in abundance - plays an important role regarding coexistence within a community. The present work sheds light on different factors affecting the coexistence of species using experimental microbial model systems consisting of a bacterivorous ciliate as the predator and two bacteria strains as prey organism. Additionally, another experimental setup consisting of two up to five bacteria species competing for one limiting resource was investigated. Highly controllable chemostat systems were established to exclude extrinsic disturbances. According to theoretical analyses I was able to show - experimentally and theoretically - that phenotypic plasticity of one species within a microbial one-predator-two-prey food web enlarges the range of possible coexistence of all species under different dynamic conditions, compared to a food web without phenotypic plasticity. This was accompanied by non-linear (chaotic) population dynamics within all experimental systems showing phenotypic plasticity. The experiments on the interplay of competition, predation and invasion showed that all aspects have an influence on species coexistence. Under undisturbed controlled conditions all aspects were analyzed in detail and in combination. Populations showed oscillations which were shown by quasi-chaotic attractors in phase space diagrams. Competition experiments with two up to five bacteria species competing for one limiting resource showed that all organisms were able to coexist which was mediated by species oscillations entering a regime of chaos. Besides that fact it was found, that the productivity (biomass) as well as the total cell numbers - under the same nutrition supply - increased by an increasing number of species in the experimental systems. Up to now, the occurrence of non-linear dynamics in well controlled experimental studies has been recognized several times and this phenomenon seemed to be more common in natural systems than generally assumed.}, language = {en} } @inproceedings{StreunAlKaddoumParletal.2012, author = {Streun, M. and Al-Kaddoum, R. and Parl, C. and Pietrzyk, U. and Ziemons, Karl and Waasen, S. van}, title = {Simulation studies of optical photons in monolithic block scintillators}, series = {2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)}, booktitle = {2011 IEEE Nuclear Science Symposium Conference Record (NSS/MIC)}, publisher = {IEEE}, address = {New York}, isbn = {978-1-4673-0120-6 (electronic ISBN)}, doi = {10.1109/NSSMIC.2011.6154621}, pages = {1380 -- 1382}, year = {2012}, abstract = {The interest in PET detectors with monolithic block scintillators is growing. In order to obtain high spatial resolutions dedicated positioning algorithms are required. But even an ideal algorithm can only deliver information which is provided by the detector. In this simulation study we investigated the light distribution on one surface of cuboid LSO scintillators of different size. Scintillators with a large aspect ratio (small footprint and large height) showed significant position information only for a minimum interaction depth of the gamma particle. The results allow a quantitative estimate for a useful aspect ratio.}, language = {en} } @article{LustfeldPithanReissel2012, author = {Lustfeld, H. and Pithan, C. and Reißel, Martin}, title = {Metallic electrolyte composites in the framework of the brick-layer model}, series = {Journal of the European Ceramic Society}, volume = {32}, journal = {Journal of the European Ceramic Society}, number = {4}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0955-2219}, doi = {10.1016/j.jeurceramsoc.2011.10.017}, pages = {859 -- 864}, year = {2012}, abstract = {It is well known that the already large dielectric constants of some electrolytes like BaTiO₃ can be enhanced further by adding metallic (e.g. Ni, Cu or Ag) nanoparticles. The enhancement can be quite large, a factor of more than 1000 is possible. The consequences for the properties will be discussed in the present paper applying a brick-layer model (BLM) for calculating dc-resistivities of thin layers and a modified one (PBLM) that includes percolation for calculating dielectric properties of these materials. The PBLM results in an at least qualitative description and understanding of the physical phenomena: This model gives an explanation for the steep increase of the dielectric constant below the percolation threshold and why this increase is connected to a dramatic decrease of the breakdown voltage as well as the ability of storing electrical energy. We conclude that metallic electrolyte composites like BaTiO₃ are not appropriate for energy storage.}, language = {en} } @inproceedings{ReisertGeisslerFloerkeetal.2012, author = {Reisert, Steffen and Geissler, H. and Fl{\"o}rke, R. and Weiler, C. and Wagner, P. and Sch{\"o}ning, Michael Josef}, title = {Characterisation of aseptic sterilisation processes using an electronic nose}, series = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, booktitle = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, editor = {Abdelghani, Adnane and Sch{\"o}ning, Michael Josef}, pages = {45 -- 45}, year = {2012}, language = {en} } @inproceedings{YoshinobuMiyamotoWagneretal.2012, author = {Yoshinobu, Tatsuo and Miyamoto, Ko-Ichiro and Wagner, Torsten and Sch{\"o}ning, Michael Josef}, title = {Miniaturized and high-speed chemical imaging systems}, series = {Nano-Biomedical Engineering 2012. Proceedings of the Tohoku University Global Centre of Excellence Programme, Sakura Hall, Tohoku University, Sendai Japan, 5 - 6 March 2012}, booktitle = {Nano-Biomedical Engineering 2012. Proceedings of the Tohoku University Global Centre of Excellence Programme, Sakura Hall, Tohoku University, Sendai Japan, 5 - 6 March 2012}, editor = {Yamaguchi, Takami}, publisher = {World Scientific}, address = {Singapur}, doi = {10.1142/9781848169067_0045}, pages = {386 -- 395}, year = {2012}, language = {en} } @article{LeursMezoOehlschlaegeretal.2012, author = {Leurs, Ulrike and Mezo, Gabor and {\"O}hlschl{\"a}ger, Peter and Orban, Erika and Marquard, Andrea and Manea, Marilena}, title = {Design, synthesis, in vitro stability and cytostatic effect of multifunctional anticancer drug-bioconjugates containing GnRH-III as a targeting moiety}, series = {Peptide Science}, volume = {98}, journal = {Peptide Science}, number = {1}, publisher = {Wiley}, address = {New York, NY}, issn = {1097-0282}, doi = {10.1002/bip.21640}, pages = {1 -- 10}, year = {2012}, abstract = {Bioconjugates containing the GnRH-III hormone decapeptide as a targeting moiety are able to deliver chemotherapeutic agents specifically to cancer cells expressing GnRH receptors, thereby increasing their local efficacy while limiting the peripheral toxicity. However, the number of GnRH receptors on cancer cells is limited and they desensitize under continuous hormone treatment. A possible approach to increase the receptor mediated tumor targeting and consequently the cytostatic effect of the bioconjugates would be the attachment of more than one chemotherapeutic agent to one GnRH-III molecule. Here we report on the design, synthesis and biochemical characterization of multifunctional bioconjugates containing GnRH-III as a targeting moiety and daunorubicin as a chemotherapeutic agent. Two different drug design approaches were pursued. The first one was based on the bifunctional [4Lys]-GnRH-III (Glp-His-Trp-Lys-His-Asp-Trp-Lys-Pro-Gly-NH2) containing two lysine residues in positions 4 and 8, whose ϵ-amino groups were used for the coupling of daunorubicin. In the second drug design, the native GnRH-III (Glp-His-Trp-Ser-His-Asp-Trp-Lys-Pro-Gly-NH2) was used as a scaffold; an additional lysine residue was coupled to the ϵ-amino group of 8Lys in order to generate two free amino groups available for conjugation of daunorubicin. The in vitro stability/degradation of all synthesized compounds was investigated in human serum, as well as in the presence of rat liver lysosomal homogenate. Their cellular uptake was determined on human breast cancer cells and the cytostatic effect was evaluated on human breast, colon and prostate cancer cell lines. Compared with a monofunctional compound, both drug design approaches resulted in multifunctional bioconjugates with increased cytostatic effect.}, language = {en} } @article{GrinsvenBonStrauvenetal.2012, author = {Grinsven, Bart van and Bon, Natalie vanden and Strauven, Hannelore and Grieten, Lars and Murib, Mohammed and Jim{\´e}nez Monroy, Kathia L. and Janssens, Stoffel D. and Haenen, Ken and Sch{\"o}ning, Michael Josef and Vermeeren, Veronique and Ameloot, Marcel and Michiels, Luc and Thoelen, Ronald and Ceuninck, Ward de and Wagner, Patrick}, title = {Heat-Transfer Resistance at Solid-Liquid Interfaces: A Tool for The Detection of Single Nucleotide Polymorphisms in DNA.}, series = {ACS Nano}, volume = {6}, journal = {ACS Nano}, number = {3}, publisher = {ACS Publications}, address = {Washington, DC}, issn = {1936-086X}, doi = {10.1021/nn300147e}, pages = {2712 -- 2721}, year = {2012}, abstract = {In this article, we report on the heat-transfer resistance at interfaces as a novel, denaturation-based method to detect single-nucleotide polymorphisms in DNA. We observed that a molecular brush of double-stranded DNA grafted onto synthetic diamond surfaces does not notably affect the heat-transfer resistance at the solid-to-liquid interface. In contrast to this, molecular brushes of single-stranded DNA cause, surprisingly, a substantially higher heat-transfer resistance and behave like a thermally insulating layer. This effect can be utilized to identify ds-DNA melting temperatures via the switching from low- to high heat-transfer resistance. The melting temperatures identified with this method for different DNA duplexes (29 base pairs without and with built-in mutations) correlate nicely with data calculated by modeling. The method is fast, label-free (without the need for fluorescent or radioactive markers), allows for repetitive measurements, and can also be extended toward array formats. Reference measurements by confocal fluorescence microscopy and impedance spectroscopy confirm that the switching of heat-transfer resistance upon denaturation is indeed related to the thermal on-chip denaturation of DNA.}, language = {en} } @inproceedings{FredebeulKreinSteingroever2012, author = {Fredebeul-Krein, Markus and Steingr{\"o}ver, Markus}, title = {Wholesale Broadband Access to IPTV in an NGA environment : how to deal with it from a regulatory perspective?}, pages = {1 -- 16}, year = {2012}, language = {en} } @inproceedings{BohrnStuetzFleischeretal.2012, author = {Bohrn, U. and St{\"u}tz, E. and Fleischer, M. and Sch{\"o}ning, Michael Josef and Wagner, P.}, title = {Towards a paradigm change - mammalian cells as sensitive biosensor layers for the detection of unexpected toxic substances in air}, series = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, booktitle = {Nanoscale Science and Technology (NS\&T´12) : Proceedings Book Humboldt Kolleg ; Tunisia, 17-19 March, 2012}, editor = {Abdelghani, Adnane and Sch{\"o}ning, Michael Josef}, pages = {44 -- 44}, year = {2012}, language = {en} } @article{OlaruKowalskiSethietal.2012, author = {Olaru, Alexandra Maria and Kowalski, Julia and Sethi, Vaishali and Bl{\"u}mich, Bernhard}, title = {Exchange relaxometry of flow at small P{\´e}clet numbers in a glass bead pack}, series = {Journal of Magnetic Resonance (JMR)}, volume = {220}, journal = {Journal of Magnetic Resonance (JMR)}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1096-0856}, doi = {10.1016/j.jmr.2012.04.015}, pages = {32 -- 44}, year = {2012}, abstract = {In this paper we consider low P{\´e}clet 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.}, language = {en} } @article{FischerKowalskiPudasaini2012, author = {Fischer, Jan-Thomas and Kowalski, Julia and Pudasaini, Shiva P.}, title = {Topographic curvature effects in applied avalanche modelling}, series = {Cold Regions Science and Technology}, volume = {74-75}, journal = {Cold Regions Science and Technology}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7441}, doi = {10.1016/j.coldregions.2012.01.005}, pages = {21 -- 30}, year = {2012}, abstract = {This paper describes the implementation of topographic curvature effects within the RApid Mass MovementS (RAMMS) snow avalanche simulation toolbox. RAMMS is based on a model similar to shallow water equations with a Coulomb friction relation and the velocity dependent Voellmy drag. It is used for snow avalanche risk assessment in Switzerland. The snow avalanche simulation relies on back calculation of observed avalanches. The calibration of the friction parameters depends on characteristics of the avalanche track. The topographic curvature terms are not yet included in the above mentioned classical model. Here, we fundamentally improve this model by mathematically and physically including the topographic curvature effects. By decomposing the velocity dependent friction into a topography dependent term that accounts for a curvature enhancement in the Coulomb friction, and a topography independent contribution similar to the classical Voellmy drag, we construct a general curvature dependent frictional resistance, and thus propose new extended model equations. With three site-specific examples, we compare the apparent frictional resistance of the new approach, which includes topographic curvature effects, to the classical one. Our simulation results demonstrate substantial effects of the curvature on the flow dynamics e.g., the dynamic pressure distribution along the slope. The comparison of resistance coefficients between the two models demonstrates that the physically based extension presents an improvement to the classical approach. Furthermore a practical example highlights its influence on the pressure outline in the run out zone of the avalanche. Snow avalanche dynamics modeling natural terrain curvature centrifugal force friction coefficients.}, language = {en} } @article{PieperKlein2012, author = {Pieper, Martin and Klein, Peter}, title = {Application of simple, periodic homogenization techniques to non-linear heat conduction problems in non-periodic, porous media}, series = {Heat mass transfer}, volume = {48}, journal = {Heat mass transfer}, number = {2}, publisher = {Springer}, address = {Berlin}, issn = {0947-7411}, doi = {10.1007/s00231-011-0879-4}, pages = {291 -- 300}, year = {2012}, abstract = {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.}, language = {en} } @article{FateriHoetterGebhardt2012, author = {Fateri, Miranda and H{\"o}tter, Jan-Steffen and Gebhardt, Andreas}, title = {Experimental and Theoretical Investigation of Buckling Deformation of Fabricated Objects by Selective Laser Melting}, series = {Physics Procedia}, volume = {39}, journal = {Physics Procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.10.062}, pages = {464 -- 470}, year = {2012}, abstract = {Although Selective Laser Melting (SLM) process is an innovative manufacturing method, there are challenges such as inferior mechanical properties of fabricated objects. Regarding this, buckling deformation which is caused by thermal stress is one of the undesired mechanical properties which must be alleviated. As buckling deformation is more observable in hard to process materials, silver is selected to be studied theoretically and experimentally for this paper. Different scanning strategies are utilized and a Finite Element Method (FEM) is applied to calculate the temperature gradient in order to determine its effect on the buckling deformation of the objects from experiments.}, language = {en} } @book{WosnitzaHilgers2012, author = {Wosnitza, Franz and Hilgers, Hans Gerd}, title = {Energieeffizienz und Energiemanagement : ein {\"U}berblick heutiger M{\"o}glichkeiten und Notwendigkeiten}, publisher = {Springer Spektrum}, address = {Wiesbaden}, isbn = {978-3-8348-1941-3}, pages = {XVII, 548 S. : Ill., graph. Darst.}, year = {2012}, language = {en} } @book{JanserHavermann2012, author = {Janser, Frank and Havermann, Marc}, title = {Inkompressible Str{\"o}mungen}, publisher = {Mainz}, address = {Aachen}, isbn = {978-3-86130-446-3}, pages = {189 S. : Ill., graph. Darst.}, year = {2012}, language = {en} } @misc{BaumgartnerWunderlichJaunichetal.2012, author = {Baumgartner, Thomas and Wunderlich, Florian and Jaunich, Arthur and Sato, Tomoo and Bundy, Georg and Grießmann, Nadine and Kowalski, Julia and Burghardt, Stefan and Hanebrink, J{\"o}rg}, title = {Lighting the way: Perspectives on the global lighting market}, edition = {2nd ed.}, address = {McKinsey}, pages = {58}, year = {2012}, language = {en} } @inproceedings{FunkeBoernerKeinzetal.2012, author = {Funke, Harald and B{\"o}rner, Sebastian and Keinz, Jan and Kusterer, K. and Kroninger, D. and Kitajima, J. and Kazari, M. and Horikama, A.}, title = {Numerical and experimental characterization of low NOx Micromix combustion principle for industrial hydrogen gas turbine applications}, series = {Proceedings of ASME Turbo Expo 2012}, booktitle = {Proceedings of ASME Turbo Expo 2012}, pages = {11}, year = {2012}, language = {en} } @inproceedings{FunkeBoernerKeinzetal.2012, author = {Funke, Harald and B{\"o}rner, Sebastian and Keinz, Jan and Hendrick, P. and Recker, E.}, title = {Low NOx Hydrogen combustion chamber for industrial gas turbine applications", 14th International Symposium on Transport Phenomena and Dynamics of Rotating Machinery}, series = {ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012}, booktitle = {ISROMAC-14 : the Forteenth International Symposium on Transport Phenomena and Dynamics of Rotating Machinery ; Honolulu, Hawaii, February 27 - March 02nd, 2012}, year = {2012}, language = {en} } @article{KirsteinMuellerWaleckiMingersetal.2012, author = {Kirstein, Simon and M{\"u}ller, Karsten and Walecki-Mingers, Mark and Deserno, Thomas M.}, title = {Robust adaptive flow line detection in sewer pipes}, series = {Automation in construction}, journal = {Automation in construction}, number = {21}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1872-7891 (E-Journal) ; 0926-5805 (Print)}, doi = {10.1016/j.autcon.2011.05.009}, pages = {24 -- 31}, year = {2012}, abstract = {As part of a novel approach to automatic sewer inspection, this paper presents a robust algorithm for automatic flow line detection. A large image repository is obtained from about 50,000 m sewers to represent the high variability of real world sewer systems. Automatic image processing combines Canny edge detection, Hough transform for straight lines and cost minimization using Dijkstra's shortest path algorithm. Assuming that flow lines are mostly smoothly connected horizontal structures, piecewise flow line delineation is reduced to a process of selecting adjacent line candidates. Costs are derived from the gap between adjacent candidates and their reliability. A single parameter α enables simple control of the algorithm. The detected flow line may precisely follow the segmented edges (α = 0.0) or minimize gaps at joints (α = 1.0). Both, manual and ground truth-based analysis indicate that α = 0.8 is optimal and independent of the sewer's material. The algorithm forms an essential step to further automation of sewer inspection.}, language = {en} } @inproceedings{GanegedaraAlahakoonMashfordetal.2012, author = {Ganegedara, H. and Alahakoon, D. and Mashford, J. and Paplinski, A. and M{\"u}ller, Karsten and Deserno, T. M.}, title = {Self organising map based region of interest labelling for automated defect identification in large sewer pipe image collections}, series = {The 2012 International Joint Conference on Neural Networks (IJCNN) : 10 - 15 June 2012, Brisbane, Australia ; [part of the] 2012 IEEE World Congress on Computational Intelligence (IEEE-WCCI 2012)}, booktitle = {The 2012 International Joint Conference on Neural Networks (IJCNN) : 10 - 15 June 2012, Brisbane, Australia ; [part of the] 2012 IEEE World Congress on Computational Intelligence (IEEE-WCCI 2012)}, publisher = {IEEE}, address = {Piscataway, NJ}, organization = {IEEE Computational Intelligence Society (IEEE-CIS)}, isbn = {978-1-4673-1490-9}, pages = {8 S.}, year = {2012}, language = {en} } @inproceedings{SauerbornHoffschmidtTelleetal.2012, author = {Sauerborn, Markus and Hoffschmidt, Bernhard and Telle, R. and Wagner, M.}, title = {Heatable optical analyse system for high temperature absorbers}, series = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, booktitle = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Solar Energy Society}, isbn = {978-1-61839-364-7}, pages = {3852 -- 3860}, year = {2012}, language = {en} } @inproceedings{SauerbornArshadiRohrmoser2012, author = {Sauerborn, Markus and Arshadi, S. and Rohrmoser, R.}, title = {Influence of clouds and aerosols to the haze of the sunshape}, series = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, booktitle = {30th ISES Biennial Solar World Congress 2011 : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Solar Energy Society}, pages = {3887 -- 3894}, year = {2012}, language = {en} } @article{SpelthahnKirsanovLeginetal.2012, author = {Spelthahn, Heiko and Kirsanov, Dmitry and Legin, Andrey and Osterrath, Thomas and Schubert, J{\"u}rgen and Zander, Willi and Sch{\"o}ning, Michael Josef}, title = {Development of a thin-film sensor array for analytical monitoring of heavy metals in aqueous solutions}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, isbn = {1862-6319}, doi = {10.1002/pssa.201100733}, pages = {885 -- 891}, year = {2012}, abstract = {In industrial processes there is a variety of heavy metals (e.g., copper, zinc, cadmium, and lead) in use for wires, coatings, paints, alloys, batteries, etc. Since the application of these transition metals for industry is inevitable, it is a vital task to develop proper analytical techniques for their monitoring at low activity levels, especially because most of these elements are acutely toxic for biological organisms. The determination of ions in solution by means of a simple and inexpensive sensor array is, therefore, a promising task. In this work, a sensor array with heavy metal-sensitive chalcogenide glass membranes for the simultaneous detection of the four ions Ag⁺, Cu2⁺, Cd2⁺, and Pb2⁺ in solution is realized. The results of the physical characterization by means of microscopy, profilometry, Rutherford backscattering spectroscopy (RBS), and scanning electron microscopy (SEM) as well as the electrochemical characterization by means of potentiometric measurements are presented. Additionally, the possibility to expand the sensor array by polymeric sensor membranes is discussed.}, language = {en} } @article{SpelthahnSchubertSchoening2012, author = {Spelthahn, Heiko and Schubert, J{\"u}rgen and Sch{\"o}ning, Michael Josef}, title = {D{\"u}nnschichtsensoren f{\"u}r die Schwermetallanalytik}, series = {GIT : Labor-Fachzeitschrift}, volume = {56}, journal = {GIT : Labor-Fachzeitschrift}, number = {4}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0016-3538}, pages = {285 -- 287}, year = {2012}, abstract = {Die Detektion von Schadstoffen repr{\"a}sentiert in der Umweltanalytik eine wichtige Aufgabenstellung. Gerade die Abwasser- bzw. Brauchwasseranalytik sowie die Prozesskontrolle haben einen hohen Stellenwert. Siliziumbasierte D{\"u}nnschichtsensoren bieten eine kosteng{\"u}nstige M{\"o}glichkeit, „online"-Messungen bzw. Vor-Ort-Messungen zeitnah durchzuf{\"u}hren. In dieser Arbeit wird ein potentiometrisches Sensorarray auf der Basis von Chalkogenidgl{\"a}sern zur Detektion von Schwermetallen in w{\"a}ssrigen Medien vorgestellt.}, language = {en} } @inproceedings{GerhardsSanderBelloum2012, author = {Gerhards, Michael and Sander, Volker and Belloum, Adam}, title = {About the flexible Migration of Workflow Tasks to Clouds : Combining on- and off-premise Executions of Applications}, series = {CLOUD COMPUTING 2012 : The Third International Conference on Cloud Computing, GRIDs, and Virtualization ; July 22-27, 2012 - Nice, France}, booktitle = {CLOUD COMPUTING 2012 : The Third International Conference on Cloud Computing, GRIDs, and Virtualization ; July 22-27, 2012 - Nice, France}, editor = {Zimmermann, Wolf and Lee, Yong Woo and Demchenko, Yuri}, publisher = {IARIA Journals}, isbn = {978-1-61208-216-5}, pages = {82 -- 87}, year = {2012}, abstract = {An increasing number of applications target their executions on specific hardware like general purpose Graphics Processing Units. Some Cloud Computing providers offer this specific hardware so that organizations can rent such resources. However, outsourcing the whole application to the Cloud causes avoidable costs if only some parts of the application benefit from the specific expensive hardware. A partial execution of applications in the Cloud is a tradeoff between costs and efficiency. This paper addresses the demand for a consistent framework that allows for a mixture of on- and off-premise calculations by migrating only specific parts to a Cloud. It uses the concept of workflows to present how individual workflow tasks can be migrated to the Cloud whereas the remaining tasks are executed on-premise.}, language = {en} } @article{KotliarLanzlHanssenetal.2012, author = {Kotliar, Konstantin and Lanzl, Ines M. and Hanssen, Henner and Eberhardt, Karla and Vilser, Walthard and Halle, Martin and Heemann, Uwe and Schmidt-Trucks{\"a}ss, Arno and Baumann, Marcus}, title = {Does increased blood pressure rather than aging influence retinal pulse wave velocity?}, series = {Investigative Ophthalmology \& Visual Science, IOVS}, volume = {53}, journal = {Investigative Ophthalmology \& Visual Science, IOVS}, number = {4}, publisher = {ARVO}, address = {Rockville, Md.}, issn = {0146-0404}, doi = {10.1167/iovs.11-8815}, pages = {2119 -- 2126}, year = {2012}, abstract = {Purpose: It was demonstrated previously that retinal pulse wave velocity (rPWV) as a measure of retinal arterial stiffness is increased in aged anamnestically healthy volunteers compared with young healthy subjects. Using novel methodology of rPWV assessment this finding was confirmed and investigated whether it might relate to the increased blood pressure usually accompanying the aging process, rather than to the aging itself. Methods: A total of 12 young 25.5-year-old (24.0-28.8) [median(1st quartile-3rd quartile)] and 12 senior 68.5-year-old (63.8-71.8) anamnestically healthy volunteers; and 12 senior 63.0-year-old (60.8-65.0) validated healthy volunteers and 12 young 33.0-year-old (29.5-35.0) hypertensive patients were examined. Time-dependent alterations of vessel diameter were assessed by the Dynamic Vessel Analyzer in a retinal artery of each subject. The data were filtered and processed using mathematical signal analysis and rPWVs were calculated. Results: rPWV amounted to 1200 (990-1470) RU (relative units)/s in the hypertensive group and to 1040 (700-2230) RU/s in anamnestically healthy seniors. These differed significantly from rPWVs in young healthy group (410 [280-500] RU/s) and in validated healthy seniors (400 [320-510] RU/s). rPWV associated with age and mean arterial pressure (MAP) in the pooled cohort excluded validated healthy seniors. In a regression model these associations remain when alternately adjusted for MAP and age. When including validated healthy seniors in the pooled cohort only association with MAP remains. Conclusions: Both aging (with not excluded cardiovascular risk factors) and mild hypertension are associated with elevated rPWV. rPWV increases to a similar extent both in young mildly hypertensive subjects and in aged anamnestically healthy persons. Healthy aging is not associated with increased rPWV.}, language = {en} } @article{BohrnStuetzFuchsetal.2012, author = {Bohrn, U. and St{\"u}tz, E. and Fuchs, K. and Fleischer, M. and Sch{\"o}ning, Michael Josef and Wagner, P.}, title = {Monitoring of irritant gas using a whole-cell-based sensor system}, series = {Sensors and Actuators B: Chemical}, volume = {175}, journal = {Sensors and Actuators B: Chemical}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0925-4005}, doi = {10.1016/j.snb.2012.05.088}, pages = {208 -- 217}, year = {2012}, abstract = {Cell-based sensors for the detection of gases have long been underrepresented, due to the cellular requirement of being cultured in a liquid environment. In this work we established a cell-based gas biosensor for the detection of toxic substances in air, by adapting a commercial sensor chip (Bionas®), previously used for the measurement of pollutants in liquids. Cells of the respiratory tract (A549, RPMI 2650, V79), which survive at a gas phase in a natural context, are used as biological receptors. The physiological cell parameters acidification, respiration and morphology are continuously monitored in parallel. Ammonia was used as a highly water-soluble model gas to test the feasibility of the sensor system. Infrared measurements confirmed the sufficiency of the medium draining method. This sensor system provides a basis for many sensor applications such as environmental monitoring, building technology and public security.}, language = {en} } @article{WernerGroebelKrumbeetal.2012, author = {Werner, Frederik and Groebel, Simone and Krumbe, Christoph and Wagner, Torsten and Selmer, Thorsten and Yoshinobu, Tatsuo and Baumann, Marcus and Sch{\"o}ning, Michael Josef}, title = {Nutrient concentration-sensitive microorganism-based biosensor}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100801}, pages = {900 -- 904}, year = {2012}, language = {en} } @article{KirchnerReisertPuetzetal.2012, author = {Kirchner, Patrick and Reisert, Steffen and P{\"u}tz, Patrick and Keusgen, Michael and Sch{\"o}ning, Michael Josef}, title = {Characterisation of polymeric materials as passivation layer for calorimetric H2O2 gas sensors}, series = {Physica Status Solidi (a)}, volume = {209}, journal = {Physica Status Solidi (a)}, number = {5}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1862-6319}, doi = {10.1002/pssa.201100773}, pages = {859 -- 863}, year = {2012}, abstract = {Calorimetric gas sensors for monitoring the H₂O₂ concentration at elevated temperatures in industrial sterilisation processes have been presented in previous works. These sensors are built up in form of a differential set-up of a catalytically active and passive temperature-sensitive structure. Although, various types of catalytically active dispersions have been studied, the passivation layer has to be established and therefore, chemically as well as physically characterised. In the present work, fluorinated ethylene propylene (FEP), perfluoralkoxy (PFA) and epoxy-based SU-8 photoresist as temperature-stable polymeric materials have been investigated for sensor passivation in terms of their chemical inertness against H₂O₂, their hygroscopic properties as well as their morphology. The polymeric materials were deposited via spin-coating on the temperature-sensitive structure, wherein spin-coated FEP and PFA show slight agglomerates. However, they possess a low absorption of humidity due to their hydrophobic surface, whereas the SU-8 layer has a closed surface but shows a slightly higher absorption of water. All of them were inert against gaseous H₂O₂ during the characterisation in H₂O₂ atmosphere that demonstrates their suitability as passivation layer for calorimetric H₂O₂ gas sensors.}, language = {en} } @article{Huening2012, author = {H{\"u}ning, Felix}, title = {Using Trench PowerMOSFETs in Linear Mode}, series = {Power Electronics Europe (2012)}, journal = {Power Electronics Europe (2012)}, publisher = {DFA Media}, address = {Tonbridge}, issn = {1748-3530}, pages = {27 -- 29}, year = {2012}, abstract = {If we think about applications for modern Power MOSFETs using trench technology, running them in linear mode may not be top of the priority list. Yet there are multiple uses for Trench Power MOSFETs in linear mode. In fact, even turning the device on and off in switching applications is a form of linear operation. Also, these components can be run in linear mode to protect the device against voltage surges. This article will illustrate the factors that need to be considered for linear operation and show how Trench Power MOSFETs are suited to it.}, language = {en} } @inproceedings{EngelsSchnabel2012, author = {Engels, Elmar and Schnabel, Holger}, title = {Rapid-control-prototyping of industrial drives for the sercos automation bus}, series = {13th International Workshop on Mechatronics (MECATRONICS), 2012 9th France-Japan \& 7th Europe-Asia Congress on and Research and Education in Mechatronics (REM)}, booktitle = {13th International Workshop on Mechatronics (MECATRONICS), 2012 9th France-Japan \& 7th Europe-Asia Congress on and Research and Education in Mechatronics (REM)}, isbn = {978-1-4673-4771-6}, pages = {177 -- 181}, year = {2012}, abstract = {This article describes the functionality of a MATLAB® library that can be used to develop motion-logic applications in MATLAB programming language for industrial drive and control systems using the well known sercos automation bus. Therewith MATLAB's functionality is extended to designing automation applications from single axis machines up to multi-kinematic robots.}, language = {en} } @inproceedings{ReisgenSchleserSchoeneetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Schoene, Jens and Hegger, Josef and Gallwoszus, J{\"o}rg and Feldmann, Markus and Kopp, Maik and G{\"u}ndel, Max}, title = {Investigation on bond mechanisms of innovative small-scale shear connectors between steel and concrete}, series = {Bond in concrete 2012. Vol. 2. Bond in new materials and under severe conditions}, booktitle = {Bond in concrete 2012. Vol. 2. Bond in new materials and under severe conditions}, editor = {Cairns, John W.}, publisher = {Publisher creations}, address = {Manerbio, Brescia}, isbn = {978-88-907078-3-4}, pages = {893 -- 898}, year = {2012}, language = {en} } @article{ReisgenSchleserMokrovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg and Ahmed, Essam}, title = {Statistical modeling of laser welding of DP/TRIP steel sheets}, series = {Optics and laser technology}, volume = {44}, journal = {Optics and laser technology}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-2545 (E-Journal); 0030-3992 (Print); 0308-4280 (Print)}, doi = {10.1016/j.optlastec.2011.05.025}, pages = {92 -- 101}, year = {2012}, abstract = {In this research work, a statistical analysis of the CO2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets was done using response surface methodology. The analysis considered the effect of laser power (2-2.2 kW), welding speed (40-50 mm/s) and focus position (-1 to 0 mm) on the heat input, the weld bead geometry, uniaxial tensile strength, formability limited dome height and welding operation cost. The experimental design was based on Box-Behnken design using linear and quadratic polynomial equations for predicting the mathematical models. The results indicate that the proposed models predict the responses adequately within the limits of welding parameters being used and the welding speed is the most significant parameter during the welding process.}, language = {en} } @article{ReisgenSchleserMokrovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg and Ahmed, Essam}, title = {Optimization of laser welding of DP/TRIP steel sheets using statistical approach}, series = {Optics and laser technology}, volume = {44}, journal = {Optics and laser technology}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1879-2545 (E-Journal); 0030-3992 (Print); 0308-4280 (Print)}, doi = {10.1016/j.optlastec.2011.06.028}, pages = {255 -- 262}, year = {2012}, abstract = {Generally, the quality of a weld joint is directly influenced by the welding input parameter settings. Selection of proper process parameters is important to obtain the desired weld bead profile and quality. In this research work, numerical and graphical optimization techniques of the CO2 laser beam welding of dual phase (DP600)/transformation induced plasticity (TRIP700) steel sheets were carried out using response surface methodology (RSM) based on Box-Behnken design. The procedure was established to improve the weld quality, increase the productivity and minimize the total operation cost by considering the welding parameters range of laser power (2-2.2 kW), welding speed (40-50 mm/s) and focus position (-1 to 0 mm). It was found that, RSM can be considered as a powerful tool in experimental welding optimization, even when the experimenter does not have a model for the process. Strong, efficient and low cost weld joints could be achieved using the optimum welding conditions.}, language = {en} } @article{ReisgenOlschokJakobsetal.2012, author = {Reisgen, Uwe and Olschok, Simon and Jakobs, Stefan and Schleser, Markus and Mokrov, Oleg and Rossiter, Eduardo}, title = {Laser beam submerged arc hybrid welding}, series = {Physics procedia}, volume = {39}, journal = {Physics procedia}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.10.016}, pages = {75 -- 83}, year = {2012}, abstract = {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.}, language = {en} } @article{ReisgenSchleserAbdurakhmanovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Gumenyuk, Andrey}, title = {Measuring of plasma properties induced by non-vacuum electron beam welding}, series = {Physics of plasma}, volume = {19}, journal = {Physics of plasma}, number = {1}, publisher = {AIP Publishing}, address = {Melville, NY}, issn = {1089-7674 (E-Journal); 1070-664X (Print)}, doi = {10.1063/1.3675874}, pages = {1 -- 7}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{QuadfliegSchoeneSchleseretal.2012, author = {Quadflieg, Till and Schoene, Jens and Schleser, Markus and Jockenh{\"o}vel, Stefan and Reisgen, Uwe and Gries, Thomas}, title = {Shear connectors for hybrid joints of metal and FRP}, series = {Diversity in composites : conference proceedings : Composites Australia and CRC-ACS 2012 conference}, booktitle = {Diversity in composites : conference proceedings : Composites Australia and CRC-ACS 2012 conference}, editor = {Heslehurst, Rikard Benton}, publisher = {Composites Australia}, address = {Hawthorne}, isbn = {978-0-9873285-0-2}, pages = {[152] -- [160]}, year = {2012}, language = {en} } @article{ReisgenSchleserMokrovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Mokrov, Oleg and Zabirov, Alexander and F{\"u}ssel, Uwe and Schnick, Michael and Hertel, Martin and Jaeckel, Sebastian}, title = {Modelling and visualisation of the GMA process}, series = {Welding and Cutting}, volume = {11}, journal = {Welding and Cutting}, number = {4}, publisher = {DVS Verlag}, address = {D{\"u}sseldorf}, issn = {1612-3433}, pages = {242 -- 249}, year = {2012}, language = {en} } @inproceedings{ReisgenSchleserAbdurakhmanovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Gumenyuk, Andrej}, title = {Application of electron beam welding to fabrication of steel-aluminium dissimilar joint}, series = {Beam technologies \& laser application : proceedings of the VII international conference, Saint Petersburg, Sept. 18-21, 2012}, booktitle = {Beam technologies \& laser application : proceedings of the VII international conference, Saint Petersburg, Sept. 18-21, 2012}, publisher = {Publ. House}, address = {Saint Petersburg}, pages = {265 -- 279}, year = {2012}, language = {en} } @article{ReisgenSchleserAbdurakhmanovetal.2012, author = {Reisgen, Uwe and Schleser, Markus and Abdurakhmanov, Aydemir and Turichin, Gleb and Valdaitseva, Elena and Bach, Friedrich-Wilhelm and Hassel, Thomas and Beniyashi, Alexander}, title = {Investigation of factors influencing the formation of weld defects in non-vacuum electron beam welding}, series = {The Paton welding journal}, volume = {2012}, journal = {The Paton welding journal}, number = {2}, publisher = {Paton Publishing House}, address = {Kiev}, issn = {0957-798X}, pages = {11 -- 18}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{FeldmannPyschnyDoeringetal.2012, author = {Feldmann, Markus and Pyschny, D. and D{\"o}ring, Bernd and Kuhnhenne, Markus}, title = {Life cycle assessment of steel constructions}, series = {Life-cycle and sustainability of civil infrastructure systems : proceedings of the Third International Symposium on Life-Cycle Civil Engineering (IALCCE'12) : Vienna, Austria, October 3-6, 2012}, booktitle = {Life-cycle and sustainability of civil infrastructure systems : proceedings of the Third International Symposium on Life-Cycle Civil Engineering (IALCCE'12) : Vienna, Austria, October 3-6, 2012}, publisher = {Taylor and Francis}, address = {Hoboken}, organization = {International Symposium on Life-Cycle Civil Engineering <3, 2012, Wien>}, isbn = {978-0-203-10336-4}, pages = {321}, year = {2012}, language = {en} } @inproceedings{KuhnhenneDoeringPyschnyetal.2012, author = {Kuhnhenne, Markus and D{\"o}ring, Bernd and Pyschny, Dominik and Feldmann, Markus}, title = {Energy efficient sandwich construction}, series = {Proceedings of the VI International Congress on Architectural Envelopes : 20.6. - 22.6.2012, San Sebastian, Spain}, booktitle = {Proceedings of the VI International Congress on Architectural Envelopes : 20.6. - 22.6.2012, San Sebastian, Spain}, publisher = {ICAE}, organization = {International Congress on Architectural Envelopes <6, 2012, San Sebastian>}, pages = {277 -- 285}, year = {2012}, language = {en} } @article{HoetterFateriGebhardt2012, author = {H{\"o}tter, Jan-Steffen and Fateri, Miranda and Gebhardt, Andreas}, title = {Selective laser melting of metals: desktop machines open up new chances even for small companies}, series = {Advanced materials research}, volume = {622-623}, journal = {Advanced materials research}, publisher = {Trans Tech Publ.}, address = {Baech}, issn = {1662-8985 (E-Journal); 1022-6680 (Print)}, doi = {10.4028/www.scientific.net/AMR.622-623.461}, pages = {461 -- 465}, year = {2012}, abstract = {Additive manufacturing (AM) of metal parts by using Selective Laser Melting (SLM) has become a powerful tool mostly in the area of automotive, aerospace engineering and others. Especially in the field of dentistry, jewelry and related branches that require individualized or even one-of-a-kind products, the direct digital manufacturing process opens up new ways of design and manufacturing. In these fields, mostly small and medium sized businesses (SME) are operating which do not have sufficient human and economic resources to invest in this technology. But to stay competitive, the application of AM can be regarded as a necessity. In this situation a new desktop machine (Realizer SLM 50) was introduced that cost about 1/3 of a shop floor SLM machine and promises small quality parts. To find out whether the machine really is an alternative for SMEs the University of Applied Science, Aachen, Germany, designed, build and optimized typical parts from the dentistry and the jewelry branches using CoCr and silver material, the latter being new with this application. The paper describes the SLM procedure and how to find and optimize the most important parameters. The test is accompanied by digital simulation in order to verify the build parameters and to plan future builds. The procedure is shown as well as the resulting parts made from CoCr and silver material.}, language = {en} } @article{BoettcherHaselhuhnJakseetal.2012, author = {Boettcher, Martin and Haselhuhn, Angelika and Jakse, Gerhard and Brehmer, Bernhard and Kirschner-Hermanns, Ruth}, title = {Overactive bladder syndrome: an underestimated long-term problem after treatment of patients with localized prostate cancer?}, series = {BJU international}, volume = {109}, journal = {BJU international}, number = {12}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1365-2176 (E-Journal); 1464-410X (E-Journal); 0007-1331 (Print); 1464-4096 (Print)}, doi = {10.1111/j.1464-410X.2011.10623.x}, pages = {1824 -- 1830}, year = {2012}, abstract = {In this study we observed courses of micturition symptoms and differentiated degrees of symptoms for each point in time while also considering the impact of bothersomeness. Our data show that not only significantly more patients who have undergone BT suffer from OAB than those who have undergone RP, but also that those affected show significantly higher values for severity of OAB symptoms throughout the whole observation period of 36 months. Our data analysis further shows that variability of OAB symptoms as well as fluctuation of severity of OAB symptoms vary to a significantly higher degree after BT than after RP. Looking only at mean figures at a given point in time clearly underestimates the underlying problem. This fact is not reflected in the literature.}, language = {en} } @article{RibitschHeumannKarletal.2012, author = {Ribitsch, D. and Heumann, S. and Karl, W. and Gerlach, J. and Leber, R. and Birner-Gruenberger, R. and Gruber, K. and Eiteljoerg, I. and Remler, P. and Siegert, Petra and Lange, J. and Maurer, Karl-Heinz and Berg, G. and Guebitz, G. M. and Schwab, H.}, title = {Extracellular serine proteases from Stenotrophomonas maltophilia: Screening, isolation and heterologous expression in E. coli}, series = {Journal of biotechnology}, volume = {157}, journal = {Journal of biotechnology}, number = {1}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-4863 (E-Journal); 0168-1656 (Print)}, doi = {10.1016/j.jbiotec.2011.09.025}, pages = {140 -- 147}, year = {2012}, abstract = {A large strain collection comprising antagonistic bacteria was screened for novel detergent proteases. Several strains displayed protease activity on agar plates containing skim milk but were inactive in liquid media. Encapsulation of cells in alginate beads induced protease production. Stenotrophomonas maltophilia emerged as best performer under washing conditions. For identification of wash-active proteases, four extracellular serine proteases called StmPr1, StmPr2, StmPr3 and StmPr4 were cloned. StmPr2 and StmPr4 were sufficiently overexpressed in E. coli. Expression of StmPr1 and StmPr3 resulted in unprocessed, insoluble protein. Truncation of most of the C-terminal domain which has been identified by enzyme modeling succeeded in expression of soluble, active StmPr1 but failed in case of StmPr3. From laundry application tests StmPr2 turned out to be a highly wash-active protease at 45 °C. Specific activity of StmPr2 determined with suc-l-Ala-l-Ala-l-Pro-l-Phe-p-nitroanilide as the substrate was 17 ± 2 U/mg. In addition we determined the kinetic parameters and cleavage preferences of protease StmPr2.}, language = {en} } @article{SchmitzWeber2012, author = {Schmitz, Philipp and Weber, Martin}, title = {Buying and selling behavior of individual investors in option-like securities}, series = {Die Betriebswirtschaft : DBW}, volume = {72}, journal = {Die Betriebswirtschaft : DBW}, number = {5}, publisher = {Sch{\"a}ffer-Poeschel}, address = {Stuttgart}, issn = {0342-7064}, doi = {10.2139/ssrn.2055088}, pages = {409 -- 426}, year = {2012}, abstract = {We analyze the trading behavior of individual investors in option-like securities, namely bankissued warrants, and thus expand the growing literature of investors behavior to a new kind of securities. A unique data set from a large German discount broker gives us the opportunity to analyze the trading behavior of 1,454 investors, making 89,958 transactions in 6,724 warrants on 397 underlyings. In different logit regression, we make use of the facts that investors can speculate on rising and falling prices of the underlying with call and put warrants and that we also have information about the stock portfolios of the investors. We report several facts about the trading behavior of individual investors in warrants that are consistent with the literature on the behavior of individual investors in the stock market. The warrant investors buy calls and sell puts if the price of the underlying has decreased over the past trading days and they sell calls and buy puts if the price of the underlying has increased. That means, the investors follow negative feedback trading strategies in all four trading categories observed. In addition, we find strong evidence for the disposition effect for call as well as put warrants, which is reversed in December. The trading behavior is also influenced if the underlying reaches some exceptionally prices, e.g. highs, lows or the strike price. We show that hedging, as one natural candidate to buy puts, does not play an important role in the market for bank-issued warrants.}, language = {en} } @article{LeidingerNoistenWollert2012, author = {Leidinger, Rafael and Noisten, Thomas and Wollert, J{\"o}rg}, title = {Realtime automation networks in moVing industrial environments}, series = {Journal of systemics, cybernetics and informatics}, volume = {Vol. 10}, journal = {Journal of systemics, cybernetics and informatics}, number = {Iss. 2}, publisher = {IIIC}, address = {Orlando}, issn = {1690-4532}, pages = {52 -- 56}, year = {2012}, abstract = {The radio-based wireless data communication has made the realization of new technical solutions possible in many fields of the automation technology (AT). For about ten years, a constant disproportionate growth of wireless technologies can be observed in the automation technology. However, it shows that especially for the AT, conventional technologies of office automation are unsuitable and/or not manageable. The employment of mobile services in the industrial automation technology has the potential of significant cost and time savings. This leads to an increased productivity in various fields of the AT, for example in the factory and process automation or in production logistics. In this paper technologies and solutions for an automation-suited supply of mobile wireless services will be introduced under the criteria of real time suitability, IT-security and service orientation. Emphasis will be put on the investigation and development of wireless convergence layers for different radio technologies, on the central provision of support services for an easy-to-use, central, backup enabled management of combined wired / wireless networks and on the study on integrability in a Profinet real-time Ethernet network.}, language = {en} } @inproceedings{Wollert2012, author = {Wollert, J{\"o}rg}, title = {The performance of UWB-communication in an industrial environment}, series = {IEEE 1st International Symposium on Wireless Systems : (IDAACS-SWS) : Offenburg, 20-21 Sept. 2012}, booktitle = {IEEE 1st International Symposium on Wireless Systems : (IDAACS-SWS) : Offenburg, 20-21 Sept. 2012}, publisher = {IEEE}, address = {Piscataway, NJ}, organization = {International Symposium on Wireless Systems <1, 2012, Offenburg>}, isbn = {978-1-4673-4678-8}, doi = {10.1109/IDAACS-SWS.2012.6377639}, pages = {85 -- 90}, year = {2012}, language = {en} } @article{MottaghyDijkshoorn2012, author = {Mottaghy, Darius and Dijkshoorn, Lydia}, title = {Implementing an effective finite difference formulation for borehole heat exchangers into a heat and mass transport code}, series = {Renewable Energy}, volume = {45}, journal = {Renewable Energy}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0960-1481}, doi = {10.1016/j.renene.2012.02.013}, pages = {59 -- 71}, year = {2012}, abstract = {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.}, language = {en} } @inproceedings{KernSchelthoffMathieu2012, author = {Kern, Alexander and Schelthoff, Christof and Mathieu, Moritz}, title = {Calculation of interception efficiencies for mesh-type air-terminations according to IEC 62305-3 using a dynamic electro-geometrical model}, series = {International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna}, booktitle = {International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna}, publisher = {IEEE}, address = {Piscataway, NJ}, organization = {International Conference on Lightning Protection <2012, Wien>}, isbn = {978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print)}, pages = {1 -- 6}, year = {2012}, language = {en} } @inproceedings{LoPiparoKernMazzetti2012, author = {Lo Piparo, G. B. and Kern, Alexander and Mazzetti, C.}, title = {Some masterpoints about risk due to lightning}, series = {International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna}, booktitle = {International Conference on Lightning Protection (ICLP) : 2 - 7 Sept. 2012, Vienna}, publisher = {IEEE}, address = {Piscataway, NJ}, organization = {International Conference on Lightning Protection <2012, Wien>}, isbn = {978-1-4673-1896-9 (E-Book) ; 978-1-4673-1898-3 (Print)}, pages = {1 -- 6}, year = {2012}, language = {en} } @article{BragardvanHoekDeDoncker2012, author = {Bragard, Michael and van Hoek, H. and De Doncker, R. W.}, title = {A major design step in IETO concept realization that allows overcurrent protection and pushes limits of switching performance}, series = {IEEE transactions on power electronics}, volume = {27}, journal = {IEEE transactions on power electronics}, number = {9}, publisher = {IEEE}, address = {New York}, issn = {0885-8993}, doi = {10.1109/TPEL.2012.2189136}, pages = {4163 -- 4171}, year = {2012}, abstract = {This paper presents the latest prototype of the integrated emitter turn-off thyristor concept, which potentially ranks among thyristor high-power devices like the gate turn-off thyristor and the integrated gate-commutated thyristor (IGCT). Due to modifications of the external driver stage and mechanical press-pack design optimization, this prototype allows for full device characterization. The turn-off capability was increased to 1600 A with an active silicon area of 823mm2 . This leads to a transient peak power of 672.1kW/cm² . Within this paper, measurements and concept assessment are presented and a comparison to state-of-the-art IGCT devices is provided.}, language = {en} } @phdthesis{Bragard2012, author = {Bragard, Michael}, title = {The integrated emitter turn-off thyristor : an innovative MOS-gated high-power device. - (Aachener Beitr{\"a}ge des ISEA ; 62)}, publisher = {Shaker}, address = {Aachen}, isbn = {978-3-8440-1152-4}, pages = {III, 164 S. : Ill., graph. Darst.}, year = {2012}, abstract = {This thesis introduces the Integrated Emitter Turn-Off (IETO) Thyristor as a new high-power device. Known state-of-the-art research activities like the Dual GCT, the ETO thyristor and the ICT were presented and critically reviewed. A comparison with commercialized solutions identifies the pros and cons of each type of device family. Based on this analysis, the IETO structure is proposed, covering most benefits of each device class. In particular the combination of a MOS-assisted turn-off with a thyristor-based device allows a voltage-controlled MOS switching and the low on-state voltage of the thyristors. The following synthesis of an IETO device stands on a three-dimensional field of optimization spanned by electric, mechanical and thermal aspects. From an electric point of view, the lowest possible parasitic inductance and resistance within the commutation path are optimization criteria. The mechanical construction has to withstand the required contact pressure of multiple kilo Newtons. Finally, thermal borders limit the maximum average current of the device. FEM simulations covering these three aspects are performed for several design proposals. An IETO prototype is constructed and measurements on various test benches attest thermal, mechanical and electric performance. A local decoupling of the external driver stage and the presspack housing is presented by a cable connection. This separation enables a thermal and mechanical independence, which is advantageous in terms of vibrations and thermal cycles including increased reliability. The electric pulse performance of the prototype device is a factor of 3.1 above today''s solutions. In single-pulse measurements, a current up to 1600 A was successfully turned off at 115°C with an active silicon area of 823 mm². One reason for this increased turn-off capability is the extremely low-inductive construction. Additional functionality of the IETO thyristor like over-current self-protection and defined short-circuit failure state are successfully verified.}, language = {en} } @inproceedings{NoetzoldUphuesWegeneretal.2012, author = {N{\"o}tzold, K. and Uphues, A. and Wegener, R. and Soter, S. and Fink, K. and Bragard, Michael and Griessel, R.}, title = {Inverter based test setup for LVRT verification of a full-scale 2 MW wind power converter}, series = {EPE Joint Wind Energy and T\&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance}, booktitle = {EPE Joint Wind Energy and T\&D Chapters Seminar : 28th and 29th of June 2012, in the Utzon Centre, Aalborg, Denmark ; papers, posters, presentations. - Session 2: Grid connection, compliance}, publisher = {EPE Association}, address = {Brussels}, year = {2012}, language = {en} } @article{EilmannRigling2012, author = {Eilmann, Britta and Rigling, Andreas}, title = {Tree-growth analyses to estimate tree species' drought tolerance}, series = {Tree Physiology}, volume = {32}, journal = {Tree Physiology}, number = {2}, editor = {Abrams, Marc}, publisher = {Oxford University Press}, address = {Oxford}, issn = {0829-318X (Print)}, doi = {10.1093/treephys/tps004}, pages = {178 -- 187}, year = {2012}, abstract = {Climate change is challenging forestry management and practices. Among other things, tree species with the ability to cope with more extreme climate conditions have to be identified. However, while environmental factors may severely limit tree growth or even cause tree death, assessing a tree species' potential for surviving future aggravated environmental conditions is rather demanding. The aim of this study was to find a tree-ring-based method suitable for identifying very drought-tolerant species, particularly potential substitute species for Scots pine (Pinus sylvestris L.) in Valais. In this inner-Alpine valley, Scots pine used to be the dominating species for dry forests, but today it suffers from high drought-induced mortality. We investigate the growth response of two native tree species, Scots pine and European larch (Larix decidua Mill.), and two non-native species, black pine (Pinus nigra Arnold) and Douglas fir (Pseudotsuga menziesii Mirb. var. menziesii), to drought. This involved analysing how the radial increment of these species responded to increasing water shortage (abandonment of irrigation) and to increasingly frequent drought years. Black pine and Douglas fir are able to cope with drought better than Scots pine and larch, as they show relatively high radial growth even after irrigation has been stopped and a plastic growth response to drought years. European larch does not seem to be able to cope with these dry conditions as it lacks the ability to recover from drought years. The analysis of trees' short-term response to extreme climate events seems to be the most promising and suitable method for detecting how tolerant a tree species is towards drought. However, combining all the methods used in this study provides a complete picture of how water shortage could limit species.}, language = {en} } @article{RiglingBiglerEilmannetal.2012, author = {Rigling, Andreas and Bigler, Christof and Eilmann, Britta and Feldmeyer-Christe, Elisabeth and Gimmi, Urs and Ginzler, Christian and Graf, Ulrich and Mayer, Phillip and Vacchiano, Giorgio and Weber, Pascal and Wohlgemuth, Thomas and zweifel, Roman and Dobbertin, Matthias}, title = {Driving factors of a vegetation shift from Scots pine to pubescent oak in dry Alpine forests}, series = {Global Change Biology}, volume = {19}, journal = {Global Change Biology}, number = {1}, publisher = {Wiley-Blackwell}, address = {Oxford}, issn = {1354-1013 (Print)}, doi = {10.1111/gcb.12038}, pages = {229 -- 240}, year = {2012}, abstract = {An increasing number of studies have reported on forest declines and vegetation shifts triggered by drought. In the Swiss Rhone valley (Valais), one of the driest inner-Alpine regions, the species composition in low elevation forests is changing: The sub-boreal Scots pine (Pinus sylvestris L.) dominating the dry forests is showing high mortality rates. Concurrently the sub-Mediterranean pubescent oak (Quercus pubescens Willd.) has locally increased in abundance. However, it remains unclear whether this local change in species composition is part of a larger-scale vegetation shift. To study variability in mortality and regeneration in these dry forests we analysed data from the Swiss national forest inventory (NFI) on a regular grid between 1983 and 2003, and combined it with annual mortality data from a monitoring site. Pine mortality was found to be highest at low elevation (below 1000 m a.s.l.). Annual variation in pine mortality was correlated with a drought index computed for the summer months prior to observed tree death. A generalized linear mixed-effects model indicated for the NFI data increased pine mortality on dryer sites with high stand competition, particularly for small-diameter trees. Pine regeneration was low in comparison to its occurrence in the overstorey, whereas oak regeneration was comparably abundant. Although both species regenerated well at dry sites, pine regeneration was favoured at cooler sites at higher altitude and oak regeneration was more frequent at warmer sites, indicating a higher adaptation potential of oaks under future warming. Our results thus suggest that an extended shift in species composition is actually occurring in the pine forests in the Valais. The main driving factors are found to be climatic variability, particularly drought, and variability in stand structure and topography. Thus, pine forests at low elevations are developing into oak forests with unknown consequences for these ecosystems and their goods and services.}, language = {en} } @inproceedings{BohrnMuchaWerneretal.2012, author = {Bohrn, Ulrich and Mucha, Andreas and Werner, Frederik and St{\"u}tz, Evamaria and B{\"a}cker, Matthias and Krumbe, Christoph and Schienle, Meinrad and Fleischer, Maximilian and Wagner, Patrick and Sch{\"o}ning, Michael Josef}, title = {Detection of toxic chromium species in water using cellbased sensor systems}, isbn = {978-3-9813484-2-2}, doi = {10.5162/IMCS2012/P2.1.14}, pages = {1364 -- 1367}, year = {2012}, language = {en} } @inproceedings{BohrnStuetzFleischeretal.2012, author = {Bohrn, Ulrich and St{\"u}tz, Evamaria and Fleischer, Maximilian and Sch{\"o}ning, Michael Josef and Wagner, Patrick}, title = {Living cell-based gas sensor system for the detection of acetone in air}, isbn = {978-3-9813484-2-2}, doi = {10.5162/IMCS2012/3.2.3}, pages = {269 -- 272}, year = {2012}, language = {en} } @inproceedings{TakenagaWernerSawadaetal.2012, author = {Takenaga, Shoko and Werner, Frederik and Sawada, Kazuaki and Sch{\"o}ning, Michael Josef}, title = {Comparison of label-free ACh image sensors based on CCD and LAPS}, isbn = {978-3-9813484-2-2}, doi = {10.5162/IMCS2012/4.2.6}, pages = {356 -- 359}, year = {2012}, language = {en} } @article{HenkenOosterhuisOehlschlaegeretal.2012, author = {Henken, F. E. and Oosterhuis, K. and {\"O}hlschl{\"a}ger, Peter and Bosch, L. and Hooijberg, E. and Haanen, J. B. A. G. and Steenbergen, R. D. M.}, title = {Preclinical safety evaluation of DNA vaccines encoding modified HPV16 E6 and E7}, series = {Vaccine}, volume = {30}, journal = {Vaccine}, number = {28}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0264-410X}, doi = {10.1016/j.vaccine.2012.04.013}, pages = {4259 -- 4266}, year = {2012}, abstract = {Persistent infection with high-risk human papillomaviruses (hrHPV) can result in the formation of anogenital cancers. As hrHPV proteins E6 and E7 are required for cancer initiation and maintenance, they are ideal targets for immunotherapeutic interventions. Previously, we have described the development of DNA vaccines for the induction of HPV16 E6 and E7 specific T cell immunity. These vaccines consist of 'gene-shuffled' (SH) versions of HPV16 E6 and E7 that were fused to Tetanus Toxin Fragment C domain 1 (TTFC) and were named TTFC-E6SH and TTFC-E7SH. Gene-shuffling was performed to avoid the risk of inducing malignant transformation at the vaccination site. Here, we describe the preclinical safety evaluation of these candidate vaccines by analysis of their transforming capacity in vitro using established murine fibroblasts (NIH 3T3 cells) and primary human foreskin keratinocytes (HFKs). We demonstrate that neither ectopic expression of TTFC-E6SH and TTFC-E7SH alone or in combination enabled NIH 3T3 cells to form colonies in soft agar. In contrast, expression of HPV16 E6WT and E7WT alone or in combination resulted in effective transformation. Similarly, retroviral transduction of HFKs from three independent donors with both TTFC-E6SH and TTFC-E7SH alone or in combination did not show any signs of immortalization. In contrast, the combined expression of E6WT and E7WT induced immortalization in HFKs from all donors. Based on these results we consider it justified to proceed to clinical evaluation of DNA vaccines encoding TTFC-E6SH and TTFC-E7SH in patients with HPV16 associated (pre)malignancies.}, language = {en} } @article{ImmelGruetzkeSpaeteetal.2012, author = {Immel, Timo and Gr{\"u}tzke, Martin and Sp{\"a}te, Anne-Katrin and Groth, Ulrich and {\"O}hlschl{\"a}ger, Peter and Huhn, Thomas}, title = {Synthesis and X-ray structure analysis of a heptacoordinate titanium(IV)-bis-chelate with enhanced in vivo antitumor efficacy}, series = {Chemical Communications}, volume = {48}, journal = {Chemical Communications}, number = {46}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1364-548X}, doi = {10.1039/C2CC31624B}, pages = {5790 -- 5792}, year = {2012}, abstract = {Chelate stabilization of a titanium(IV)-salan alkoxide by ligand exchange with 2,6-pyridinedicarboxylic acid (dipic) resulted in heptacoordinate complex 3 which is not redox-active, stable on silica gel and has increased aqueous stability. 3 is highly toxic in HeLa S3 and Hep G2 and has enhanced antitumor efficacy in a mouse cervical-cancer model.}, language = {en} } @inproceedings{Bung2012, author = {Bung, Daniel Bernhard}, title = {Sensitivity of phase detection techniques in aerated chute flows to hydraulic design parameters}, series = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, booktitle = {2nd European IAHR congress : 27. - 29. June 2012, M{\"u}nchen}, publisher = {Lehrstuhl u. Versuchsanst. f{\"u}r Wasserbau u. Wasserwirtschaft d. TU M{\"u}nchen}, address = {M{\"u}nchen}, organization = {International Association for Hydraulic Engineering and Research}, isbn = {978-3-943683-03-5}, pages = {Artikelkennnummer: B15}, year = {2012}, language = {en} } @inproceedings{FrickeZiolkoAnthrakidisetal.2012, author = {Fricke, Barbara and Ziolko, C. and Anthrakidis, Anette and Alexopoulos, Spiros and Hoffschmidt, Bernhard and Giese, F. and Dillig, M.}, title = {InnoSol - environmental aspects of the open volumetric receiver technology}, series = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, booktitle = {30th ISES Biennial Solar World Congress 2011 : : Kassel, Germany, 28 August - 2 September 2011. Vol. 5}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Solar Energy Society}, pages = {3895 -- 3900}, year = {2012}, language = {en} } @book{Bialonski2012, author = {Bialonski, Stephan}, title = {Inferring complex networks from time series of dynamical systems: Pitfalls, misinterpretations, and possible solutions}, publisher = {Universit{\"a}ts- und Landesbibliothek Bonn}, address = {Bonn}, pages = {Online-Ausgabe (III, 135 S. : Ill., graph. Darst.)}, year = {2012}, language = {en} } @inproceedings{SauerbornKlimekHoffschmidtetal.2012, author = {Sauerborn, Markus and Klimek, J. and Hoffschmidt, Bernhard and Essen, H. and Sieger, S. and Biegel, G. and G{\"o}ttsche, Joachim and Hilger, Patrick}, title = {Eurosun 2012 : radar technology for heliostat posititon control}, series = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012}, booktitle = {Eurosun 2012 : Solar energy for a brighter future : conference proceedings : Rijeka, 18.-22.09.2012}, address = {Rijeka}, pages = {ID 80}, year = {2012}, language = {en} } @inproceedings{DuongNguyenStaat2012, author = {Duong, Minh Tuan and Nguyen, Nhu Hunyh and Staat, Manfred}, title = {Finite Element Implementation of a 3D Fung-type Model}, series = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, booktitle = {ESMC-2012 - 8th European Solid Mechanics Conference, Graz, Austria, July 9-13, 2012}, publisher = {Verlag d. Technischen Universit{\"a}t Graz}, address = {Graz}, isbn = {978-3-85125-223-1}, year = {2012}, language = {en} } @misc{LindelGreiserWaxmanetal.2012, author = {Lindel, Tomasz Dawid and Greiser, Andreas and Waxman, Patrick and Dietterle, Martin and Seifert, Frank and Fontius, Ulrich and Renz, Wolfgang and Dieringer, Matthias A. and Frauenrath, Tobias and Schulz-Menger, Jeanette and Niendorf, Thoralf and Ittermann, Bernd}, title = {Cardiac CINE MRI at 7 T using a transmit array}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {With its need for high SNR and short acquisition times, Cardiac MRI (CMR) is an intriguing target application for ultrahigh field MRI. Due to the sheer size of the upper torso, however, the known RF issues of 7T MRI are also most prominent in CMR. Recent years brought substantial progress but the full potential of the ultrahigh field for CMR is yet to be exploited. Parallel transmission (pTx) is a promising approach in this context and several groups have already reported B1 shimming for 7T CMR. In such a static pTx application amplitudes and phases of all Tx channels are adjusted individually but otherwise imaging techniques established in current clinical practice 1.5 T and 3 T are applied. More advanced forms of pTx as spatially selective excitation (SSE) using Transmit SENSE promise additional benefits like faster imaging with reduced fields of view or improved SAR control. SSE requires the full dynamic capabilities of pTx, however, and for the majority of today's implemented pTx hardware the internal synchronization of the Tx array does not easily permit external triggering as needed for CMR. Here we report a software solution to this problem and demonstrate the feasibility of CINE CMR at 7 T using a Tx array.}, language = {en} } @article{FerreinSteinbauerVassos2012, author = {Ferrein, Alexander and Steinbauer, Gerald and Vassos, Stavros}, title = {Action-Based Imperative Programming with YAGI}, pages = {24 -- 31}, year = {2012}, abstract = {Many tasks for autonomous agents or robots are best described by a specification of the environment and a specification of the available actions the agent or robot can perform. Combining such a specification with the possibility to imperatively program a robot or agent is what we call the actionbased imperative programming. One of the most successful such approaches is Golog. In this paper, we draft a proposal for a new robot programming language YAGI, which is based on the action-based imperative programming paradigm. Our goal is to design a small, portable stand-alone YAGI interpreter. We combine the benefits of a principled domain specification with a clean, small and simple programming language, which does not exploit any side-effects from the implementation language. We discuss general requirements of action-based programming languages and outline YAGI, our action-based language approach which particularly aims at embeddability.}, language = {en} } @inproceedings{AchenbachGeimerLynenetal.2012, author = {Achenbach, Timm and Geimer, Konstantin and Lynen, Arthur and G{\"o}ttsche, Joachim and Hoffschmidt, Bernhard}, title = {Simulation of thermo-mechanical processes in open volumetric absorber modules}, series = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko}, booktitle = {SolarPaces 2012 : concentrating solar power and chemical energy systems : Sept. 11 - 14 2012, Marrakech, Marokko}, pages = {1 -- 8}, year = {2012}, language = {en} } @incollection{HoffschmidtAlexopoulosGoettscheetal.2012, author = {Hoffschmidt, Bernhard and Alexopoulos, Spiros and G{\"o}ttsche, Joachim and Sauerborn, Markus}, title = {High concentration solar collectors}, series = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, volume = {3}, booktitle = {Comprehensive renewable energy / ed. Ali Sayigh. Vol. 3: Solar thermal systems: components and applications}, publisher = {Elsevier}, address = {Amsterdam}, isbn = {978-0-08-087873-7}, doi = {10.1016/B978-0-08-087872-0.00306-1}, pages = {165 -- 209}, year = {2012}, abstract = {Solar thermal concentrated power is an emerging technology that provides clean electricity for the growing energy market. To the solar thermal concentrated power plant systems belong the parabolic trough, the Fresnel collector, the solar dish, and the central receiver system. For high-concentration solar collector systems, optical and thermal analysis is essential. There exist a number of measurement techniques and systems for the optical and thermal characterization of the efficiency of solar thermal concentrated systems. For each system, structure, components, and specific characteristics types are described. The chapter presents additionally an outline for the calculation of system performance and operation and maintenance topics. One main focus is set to the models of components and their construction details as well as different types on the market. In the later part of this chapter, different criteria for the choice of technology are analyzed in detail.}, language = {en} } @article{KurulganDemirciDemirciLinderetal.2012, author = {Kurulgan Demirci, Eylem and Demirci, Taylan and Linder, Peter and Trzewik, J{\"u}rgen and Gierkowski, Jessica Ricarda and Gossmann, Matthias and Kayser, Peter and Porst, Dariusz and Digel, Ilya and Artmann, Gerhard and Temiz Artmann, Ayseg{\"u}l}, title = {rhAPC reduces the endothelial cell permeability via a decrease of contractile tensions induced by endothelial cells}, series = {Journal of Bioscience and Bioengineering}, volume = {113}, journal = {Journal of Bioscience and Bioengineering}, number = {2}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1347-4421}, doi = {10.1016/j.jbiosc.2012.03.019}, pages = {212 -- 219}, year = {2012}, abstract = {All cells generate contractile tension. This strain is crucial for mechanically controlling the cell shape, function and survival. In this study, the CellDrum technology quantifying cell's (the cellular) mechanical tension on a pico-scale was used to investigate the effect of lipopolysaccharide (LPS) on human aortic endothelial cell (HAoEC) tension. The LPS effect during gram-negative sepsis on endothelial cells is cell contraction causing endothelium permeability increase. The aim was to finding out whether recombinant activated protein C (rhAPC) would reverse the endothelial cell response in an in-vitro sepsis model. In this study, the established in-vitro sepsis model was confirmed by interleukin 6 (IL-6) levels at the proteomic and genomic levels by ELISA, real time-PCR and reactive oxygen species (ROS) activation by florescence staining. The thrombin cellular contraction effect on endothelial cells was used as a positive control when the CellDrum technology was applied. Additionally, the Ras homolog gene family, member A (RhoA) mRNA expression level was checked by real time-PCR to support contractile tension results. According to contractile tension results, the mechanical predominance of actin stress fibers was a reason of the increased endothelial contractile tension leading to enhanced endothelium contractility and thus permeability enhancement. The originality of this data supports firstly the basic measurement principles of the CellDrum technology and secondly that rhAPC has a beneficial effect on sepsis influenced cellular tension. The technology presented here is promising for future high-throughput cellular tension analysis that will help identify pathological contractile tension responses of cells and prove further cell in-vitro models.}, language = {en} } @inproceedings{RosemannEggertVoigtetal.2012, author = {Rosemann, Michael and Eggert, Mathias and Voigt, Matthias and Beverungen, Daniel}, title = {Leveraging Social Network Data for Analytical CRM Strategies - The Introduction of Social BI.}, series = {ECIS 2012 Proceedings}, booktitle = {ECIS 2012 Proceedings}, pages = {12 S.}, year = {2012}, language = {en} } @inproceedings{DachwaldFeldmannEspeetal.2012, author = {Dachwald, Bernd and Feldmann, Marco and Espe, Clemens and Plescher, Engelbert and Konstantinidis, K. and Forstner, R.}, title = {Enceladus explorer - A maneuverable subsurface probe for autonomous navigation through deep ice}, series = {63rd International Astronautical Congress 2012, IAC 2012; Naples; Italy; 1 October 2012 through 5 October 2012. (Proceedings of the International Astronautical Congress, IAC ; 3)}, booktitle = {63rd International Astronautical Congress 2012, IAC 2012; Naples; Italy; 1 October 2012 through 5 October 2012. (Proceedings of the International Astronautical Congress, IAC ; 3)}, publisher = {Curran}, address = {Red Hook, NY}, organization = {International Astronautical Congress <63, 2012, Napoli>}, isbn = {978-1-62276-979-7}, pages = {1756 -- 1766}, year = {2012}, language = {en} } @article{OertelBung2012, author = {Oertel, Mario and Bung, Daniel Bernhard}, title = {Initial stage of two-dimensional dam-break waves: laboratory versus VOF}, series = {Journal of hydraulic research}, volume = {50}, journal = {Journal of hydraulic research}, number = {1}, publisher = {Taylor \& Francis}, address = {London}, issn = {1814-2079 (E-Journal); 0022-1686 (Print)}, doi = {10.1080/00221686.2011.639981}, pages = {89 -- 97}, year = {2012}, abstract = {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.}, language = {en} } @article{NguyenDuongTranetal.2012, author = {Nguyen, Nhu Huynh and Duong, Minh Tuan and Tran, Thanh Ngoc and Pham, Phu Tinh and Grottke, O. and Tolba, R. and Staat, Manfred}, title = {Influence of a freeze-thaw cycle on the stress-stretch curves of tissues of porcine abdominal organs}, series = {Journal of Biomechanics}, volume = {45}, journal = {Journal of Biomechanics}, number = {14}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2380}, doi = {10.1016/j.jbiomech.2012.07.008}, pages = {2382 -- 2386}, year = {2012}, abstract = {The paper investigates both fresh porcine spleen and liver and the possible decomposition of these organs under a freeze-thaw cycle. The effect of tissue preservation condition is an important factor which should be taken into account for protracted biomechanical tests. In this work, tension tests were conducted for a large number of tissue specimens from twenty pigs divided into two groups of 10. Concretely, the first group was tested in fresh state; the other one was tested after a freeze-thaw cycle which simulates the conservation conditions before biomechanical experiments. A modified Fung model for isotropic behavior was adopted for the curve fitting of each kind of tissues. Experimental results show strong effects of the realistic freeze-thaw cycle on the capsule of elastin-rich spleen but negligible effects on the liver which virtually contains no elastin. This different behavior could be explained by the autolysis of elastin by elastolytic enzymes during the warmer period after thawing. Realistic biomechanical properties of elastin-rich organs can only be expected if really fresh tissue is tested. The observations are supported by tests of intestines.}, language = {en} } @article{StaatTrenzLohmannetal.2012, author = {Staat, Manfred and Trenz, Eva and Lohmann, Philipp and Frotscher, Ralf and Klinge, Uwe and Tabaza, Ruth and Kirschner-Hermanns, Ruth}, title = {New measurements to compare soft tissue anchoring systems in pelvic floor surgery}, series = {Journal of Biomedical Materials Research Part B: Applied Biomaterials}, volume = {100B}, journal = {Journal of Biomedical Materials Research Part B: Applied Biomaterials}, number = {4}, publisher = {Wiley}, address = {Hoboken, NJ}, issn = {1552-4981}, doi = {10.1002/jbm.b.32654}, pages = {924 -- 933}, year = {2012}, abstract = {Suburethral slings as well as different meshes are widely used treating stress urinary incontinence and prolaps in women. With the development of MiniSlings and special meshes using less alloplastic material anchorage systems become more important to keep devices in place and to put some tension especially on the MiniSlings. To date, there are many different systems of MiniSlings of different companies on the market which differ in the structure of the used meshes and anchors. A new objective measurement method to compare different properties of MiniSling systems (mesh and anchor) is presented in this article. Ballistic gelatine acts as soft tissue surrogate. Significant differences in parameters like pull-out strength of anchors or shrinkage of meshes under loading conditions have been determined. The form and size of the anchors as well as the structural stability of the meshes are decisive for a proper integration. The tested anchorings sytems showed markedly different mechanical function at their respective load bearing capacity. As the stable fixation of the device in tissue is a prerequisite for a permanet reinforcement, the proposed test system permits further optimisation of anchor and mesh devices to improve the success of the surgical treatment}, language = {en} } @article{NovacekTranKlingeetal.2012, author = {Novacek, V. and Tran, Thanh Ngoc and Klinge, U. and Tolba, R. H. and Staat, Manfred and Bronson, D. G. and Miesse, A. M. and Whiffen, J. and Turquier, F.}, title = {Finite element modelling of stapled colorectal end-to-end anastomosis : Advantages of variable height stapler design}, series = {Journal of Biomechanics}, volume = {45}, journal = {Journal of Biomechanics}, number = {115}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1873-2380}, doi = {10.1016/j.jbiomech.2012.07.021}, pages = {2693 -- 2697}, year = {2012}, abstract = {The impact of surgical staplers on tissues has been studied mostly in an empirical manner. In this paper, finite element method was used to clarify the mechanics of tissue stapling and associated phenomena. Various stapling modalities and several designs of circular staplers were investigated to evaluate the impact of the device on tissues and mechanical performance of the end-to-end colorectal anastomosis. Numerical simulations demonstrated that a single row of staples is not adequate to resist leakage due to non-linear buckling and opening of the tissue layers between two adjacent staples. Compared to the single staple row configuration, significant increase in stress experienced by the tissue at the inner staple rows was observed in two and three rows designs. On the other hand, adding second and/or third staple row had no effect on strain in the tissue inside the staples. Variable height design with higher staples in outer rows significantly reduced the stresses and strains in outer rows when compared to the same configuration with flat cartridge.}, language = {en} } @article{BassamHeschelerTemizArtmannetal.2012, author = {Bassam, Rasha and Hescheler, J{\"u}rgen and Temiz Artmann, Ayseg{\"u}l and Artmann, Gerhard and Digel, Ilya}, title = {Effects of spermine NONOate and ATP on the thermal stability of hemoglobin}, series = {BMC Biophysics}, volume = {5}, journal = {BMC Biophysics}, publisher = {BioMed Central}, address = {London}, issn = {2046-1682}, doi = {10.1186/2046-1682-5-16}, pages = {Art. 16}, year = {2012}, abstract = {Background Minor changes in protein structure induced by small organic and inorganic molecules can result in significant metabolic effects. The effects can be even more profound if the molecular players are chemically active and present in the cell in considerable amounts. The aim of our study was to investigate effects of a nitric oxide donor (spermine NONOate), ATP and sodium/potassium environment on the dynamics of thermal unfolding of human hemoglobin (Hb). The effect of these molecules was examined by means of circular dichroism spectrometry (CD) in the temperature range between 25°C and 70°C. The alpha-helical content of buffered hemoglobin samples (0.1 mg/ml) was estimated via ellipticity change measurements at a heating rate of 1°C/min. Results Major results were: 1) spermine NONOate persistently decreased the hemoglobin unfolding temperature T u irrespectively of the Na + /K + environment, 2) ATP instead increased the unfolding temperature by 3°C in both sodium-based and potassium-based buffers and 3) mutual effects of ATP and NO were strongly influenced by particular buffer ionic compositions. Moreover, the presence of potassium facilitated a partial unfolding of alpha-helical structures even at room temperature. Conclusion The obtained data might shed more light on molecular mechanisms and biophysics involved in the regulation of protein activity by small solutes in the cell.}, language = {en} } @incollection{NiendorfWinterFrauenrath2012, author = {Niendorf, Thoralf and Winter, Lukas and Frauenrath, Tobias}, title = {Electrocardiogram in an MRI environment: Clinical needs, practical considerations, safety implications, technical solutions and fFuture directions}, series = {Advances in Electrocardiograms - Methods and Analysis}, booktitle = {Advances in Electrocardiograms - Methods and Analysis}, editor = {Millis, Richard}, publisher = {IntechOpen}, address = {London}, isbn = {978-953-307-923-3 (print)}, doi = {10.5772/24340}, pages = {309 -- 324}, year = {2012}, language = {en} } @article{MansurovDigelBiisenbaevetal.2012, author = {Mansurov, Z. and Digel, Ilya and Biisenbaev, M. and Savistkaya, I. and Kistaubaeva, A. and Akimbekov, Nuraly S. and Zhubanova, A.}, title = {Bio-composite material on the basis of carbonized rice husk in biomedicine and environmental applications}, series = {Eurasian Chemico-Technological Journal}, volume = {14}, journal = {Eurasian Chemico-Technological Journal}, number = {2}, publisher = {Institute of Combustion Problems}, address = {Almaty}, issn = {2522-4867}, doi = {10.18321/ectj105}, pages = {115 -- 131}, year = {2012}, language = {en} } @article{FrauenrathFuchsDieringeretal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Dieringer, Matthias A. and {\"O}zerdem, Celal and Patel, Nishan and Renz, Wolfgang and Greiser, Andreas and Elgeti, Thomas and Niendorf, Thoralf}, title = {Detailing the use of magnetohydrodynamic effects for synchronization of MRI with the cardiac cycle: A feasibility study}, series = {Journal of Magnetic Resonance Imaging}, volume = {36}, journal = {Journal of Magnetic Resonance Imaging}, number = {2}, publisher = {Wiley-Liss}, address = {New York}, issn = {1522-2586}, doi = {10.1002/jmri.23634}, pages = {364 -- 372}, year = {2012}, abstract = {Purpose: To investigate the feasibility of using magnetohydrodynamic (MHD) effects for synchronization of magnetic resonance imaging (MRI) with the cardiac cycle. Materials and Methods: The MHD effect was scrutinized using a pulsatile flow phantom at B0 = 7.0 T. MHD effects were examined in vivo in healthy volunteers (n = 10) for B0 ranging from 0.05-7.0 T. Noncontrast-enhanced MR angiography (MRA) of the carotids was performed using a gated steady-state free-precession (SSFP) imaging technique in conjunction with electrocardiogram (ECG) and MHD synchronization. Results: The MHD potential correlates with flow velocities derived from phase contrast MRI. MHD voltages depend on the orientation between B0 and the flow of a conductive fluid. An increase in the interelectrode spacing along the flow increases the MHD potential. In vivo measurement of the MHD effect provides peak voltages of 1.5 mV for surface areas close to the common carotid artery at B0 = 7.0 T. Synchronization of MRI with the cardiac cycle using MHD triggering is feasible. MHD triggered MRA of the carotids at 3.0 T showed an overall image quality and richness of anatomic detail, which is comparable to ECG-triggered MRAs. Conclusion: This feasibility study demonstrates the use of MHD effects for synchronization of MR acquisitions with the cardiac cycle. J. Magn. Reson. Imaging 2012;36:364-372. © 2012 Wiley Periodicals, Inc.}, language = {en} } @inproceedings{FerreinKallweitLautermann2012, author = {Ferrein, Alexander and Kallweit, Stephan and Lautermann, Mark}, title = {Towards an autonomous pilot system for a tunnel boring machine}, series = {5th Robotics and Mechatronics Conference of South Africa (ROBMECH) : 26 - 27 November 2012 ; CSIR International Conference Centre Gauteng South Africa}, booktitle = {5th Robotics and Mechatronics Conference of South Africa (ROBMECH) : 26 - 27 November 2012 ; CSIR International Conference Centre Gauteng South Africa}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-4673-5183-6}, year = {2012}, language = {en} } @misc{FrauenrathFuchsHezeletal.2012, author = {Frauenrath, Tobias and Fuchs, Katharina and Hezel, Fabian and Dieringer, Matthias A. and Rieger, Jan and Niendorf, Thoralf}, title = {Improved cardiac triggering by combining multiple physiological signals: a cardiac MR feasibility study at 7.0 T}, series = {2012 ISMRM Annual Meeting Proceedings}, journal = {2012 ISMRM Annual Meeting Proceedings}, issn = {1545-4428}, year = {2012}, abstract = {In current clinical cardiovascular MR (CMR) practice cardiac motion is commonly dealt with using ECG based synchronization. However, ECG is corrupted by magneto-hydrodynamic (MHD) effects in magnetic fields. This leads to artifacts in the ECG trace and evokes severe T-wave elevations, which might be misinterpreted as R-waves resulting in erroneous triggering. At (ultra)high field strengths, the propensity of ECG recordings to MHD effects is further pronounced. Pulse oximetry (POX) being inherently sensitive to blood oxygenation provides an alternative approach for cardiac gating. However, due to the travel time of the blood the peak of maximum oxygenation and hence the trigger is delayed by approx. 300 ms with respect to the ECG's R-wave. Also the peak of maximum oxygenation shows a jitter of up to 65 ms. Alternative triggering approaches include acoustic cardiac triggering (ACT). In current clinical practice cardiac gating / triggering commonly relies on using single physiological signals only. Realizing this limitation this study proposes a combined triggering approach which exploits multiple physiological signals including ECG, POX or ACT to track cardiac activity. The feasibility of the coupled approach is examined for LV function assessment at 7.0 T. For this purpose, breath-held 2D-CINE imaging in conjunction with cardiac synchronization was performed paralleled by real time logging of physiological waveforms to track (mis)synchronization between the cardiac cycle and data acquisition. Combinations of the ECG, POX and ACT signals were evaluated and processed in real time to facilitate reliable trigger information.}, language = {en} } @article{ScheerBalimaneHaywardetal.2012, author = {Scheer, Nico and Balimane, Praveen and Hayward, Michael D. and Buechel, Sandra and Kauselmann, Gunther and Wolf, C. Roland}, title = {Generation and Characterization of a Novel Multidrug Resistance Protein 2 Humanized Mouse Line}, series = {Drug Metabolism and Disposition}, volume = {40}, journal = {Drug Metabolism and Disposition}, number = {11}, publisher = {ASPET}, address = {Bethesda, Md.}, issn = {1521-0111}, doi = {10.1124/dmd.112.047605}, pages = {2212 -- 2218}, year = {2012}, abstract = {The multidrug resistance protein (MRP) 2 is predominantly expressed in liver, intestine, and kidney, where it plays an important role in the excretion of a range of drugs and their metabolites or endogenous compounds into bile, feces, and urine. Mrp knockout [Mrp2(-/-)] mice have been used recently to study the role of MRP2 in drug disposition. Here, we describe the first generation and initial characterization of a mouse line humanized for MRP2 (huMRP2), which is nulled for the mouse Mrp2 gene and expresses the human transporter in the organs and cell types where MRP2 is normally expressed. Analysis of the mRNA expression for selected cytochrome P450 and transporter genes revealed no major changes in huMRP2 mice compared with wild-type controls. We show that human MRP2 is able to compensate functionally for the loss of the mouse transporter as demonstrated by comparable bilirubin levels in the humanized mice and wild-type controls, in contrast to the hyperbilirubinemia phenotype that is observed in MRP2(-/-) mice. The huMRP2 mouse provides a model to study the role of the human transporter in drug disposition and in assessing the in vivo consequences of inhibiting this transporter by compounds interacting with human MRP2.}, language = {en} }