@article{PrantlEigenbergerReinhardetal., author = {Prantl, Lukas and Eigenberger, Andreas and Reinhard, Ruben and Siegmund, Andreas and Heumann, Kerstin and Felthaus, Oliver}, title = {Cell-Enriched Lipotransfer (CELT) Improves Tissue Regeneration and Rejuvenation without Substantial Manipulation of the Adipose Tissue Graft}, series = {Cells}, volume = {11}, journal = {Cells}, number = {19}, publisher = {MDPI}, doi = {10.3390/cells11193159}, pages = {1 -- 11}, abstract = {The good availability and the large content of adult stem cells in adipose tissue has made it one of the most interesting tissues in regenerative medicine. Although lipofilling is one of the most frequent procedures in plastic surgery, the method still struggles with high absorption rates and volume losses of up to 70\%. Therefore, many efforts have been made to optimize liposuction and to process the harvested tissue in order to increase fat graft retention. Because of their immunomodulatory properties, their cytokine secretory activity, and their differentiation potential, enrichment with adipose tissue-derived stem cells was identified as a promising tool to promote transplant survival. Here, we review the important parameters for lipofilling optimization. Finally, we present a new method for the enrichment of lipoaspirate with adipose tissue-derived stem cells and discuss the parameters that contribute to fat graft survival.}, language = {en} } @article{LaumerKargSchmidt, author = {Laumer, Tobias and Karg, Michael Cornelius Hermann and Schmidt, Michael}, title = {Laser Beam Melting of Multi-Material Components}, series = {Physics Procedia}, volume = {39}, journal = {Physics Procedia}, publisher = {Elsevier}, issn = {1875-3892}, doi = {10.1016/j.phpro.2012.10.068}, pages = {518 -- 525}, abstract = {First results regarding the realisation of multi-material components manufactured by Laser Beam Melting of polymers and metals are published. For realising composite structures from polymer powders by additive manufacturing, at first relevant material properties regarding compatibility have to be analysed. The paper shows the main requirements for compatibility between different materials and offers first results in form of a compatibility matrix of possible combinations for composite structures.For achieving gradient properties of additively manufactured metal parts by using composite materials the composition of alloying components in the powder and adapted process strategies are varied. As an alternative to atomizing pre-alloyed materials, mixtures of different powders are investigated.}, language = {en} } @article{WidbillerKeimSchlichtingetal., author = {Widbiller, Matthias and Keim, Lukas and Schlichting, Ralf and Striegl, Birgit and Hiller, Karl-Anton and Jungbauer, Rebecca and Buchalla, Wolfgang and Galler, Kerstin M.}, title = {Debris Removal by Activation of Endodontic Irrigants in Complex Root Canal Systems}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {16}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app11167331}, pages = {1 -- 14}, abstract = {Aim of the study was to develop a standardized model system to investigate endodontic irrigation techniques and assess the efficiency of different activation methods on the removal of hard tissue debris in complex root canal systems. Mesial roots of mandibular molars were firstly scanned by micro-computed tomography (µCT) and allocated to three groups of irrigant activation: sonic activation (EDDY, VDW, Munich, Germany), laser activation (AutoSWEEPS, FOTONA, Ljubljana, Slovenia) and conventional needle irrigation (control). Roots were fixed in individual 3D-printed holders to facilitate root canal enlargement under constant irrigation with NaOCl (5\%). To enable standardized quantification of remaining debris, BaSO4-enriched dentine powder was compacted into the canals, followed by another µCT-scan. The final irrigation was performed using 17\% ethylenediaminetetraacetic acid (EDTA) and 5\% sodium hypochlorite (NaOCl) with the respective activation method, and the volume of remaining artificial debris was quantified after a final µCT-scan. The newly developed model system allowed for reliable, reproducible and standardized assessment of irrigation methods. Activation of the irrigant proved to be significantly more effective than conventional needle irrigation regarding the removal of debris, which persisted particularly in the apical third of the root canal in the control group. The efficiency of irrigation was significantly enhanced with laser- and sonic-based activation, especially in the apical third.}, language = {en} } @incollection{Giese, author = {Giese, Constanze}, title = {Roboter als Hoffnungstr{\"a}ger in der Pflege: Pflegeethische Zug{\"a}nge zur Einsch{\"a}tzung k{\"u}nftiger Einsatzm{\"o}glichkeiten}, series = {Digitale Technik f{\"u}r ambulante Pflege und Therapie II - Impulse f{\"u}r die Praxis}, booktitle = {Digitale Technik f{\"u}r ambulante Pflege und Therapie II - Impulse f{\"u}r die Praxis}, editor = {Weber, Karsten and Haug, Sonja and Mohr, Christa and Lauer, Norina and Pfingsten, Andrea and Raptis, Georgios and Bahr, Gudrun}, publisher = {transcript}, address = {Bielefeld}, doi = {10.14361/9783839467275-010}, pages = {115 -- 130}, language = {de} } @article{OsmanlicWudyLaumeretal., author = {Osmanlic, Fuad and Wudy, Katrin and Laumer, Tobias and Schmidt, Michael and Drummer, Dietmar and K{\"o}rner, Carolin}, title = {Modeling of Laser Beam Absorption in a Polymer Powder Bed}, series = {Polymers}, volume = {10}, journal = {Polymers}, number = {7}, publisher = {MDPI}, doi = {10.3390/polym10070784}, pages = {1 -- 11}, abstract = {In order to understand the absorption characteristic, a ray trace model is developed by taking into account the reflection, absorption and refraction. The ray paths are resolved on a sub-powder grid. For validation, the simulation results are compared to analytic solutions of the irradiation of the laser beam onto a plain surface. In addition, the absorptance, reflectance and transmittance of PA12 powder layers measured by an integration sphere setup are compared with the numerical results of our model. It is shown that the effective penetration depth can be lower than the penetration depth in bulk material for polymer powders and, therefore, can increase the energy density at the powder bed surface. The implications for modeling of the selective laser sintering (SLS) process and the processability of fine powder distributions and high powder bed densities are discussed.}, language = {en} } @misc{RollerRudolphEcketal., author = {Roller, Katrin and Rudolph, Clarissa and Eck, Sandra and Schneider, Kyra and Vischer, Nina}, title = {Wohnen, Care, Geschlecht - Theorie und Praxis kollektiven Wohnens aus Geschlechterperspektive}, publisher = {Westf{\"a}lisches Dampfboot}, address = {M{\"u}nster}, isbn = {978-3-98634-175-6}, doi = {10.56715/398634175}, language = {de} } @article{HaynackSekandarJithenderetal., author = {Haynack, Alexander and Sekandar, Zadran and Jithender, J. Timothy and Gambarelli, Serena and Kr{\"a}nkel, Thomas and Thiel, Charlotte and Ozbolt, Josko and Gehlen, Christoph}, title = {Can a Hend-Held 3D Scanner Capture Temperature-Induced Strain of Mortar Samples? Comparison between Experimental Measurements and Numerical Simulations}, series = {mathematics}, volume = {11}, journal = {mathematics}, number = {17}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/math11173672}, abstract = {The expected lifespan of cement-based materials, particularly concrete, is at least 50 years. Changes in the pore structure of the material need to be considered due to external influences and associated transport processes. The expansion behaviour of concrete and mortar during freeze-thaw attacks, combined with de-icing salt agents, is crucial for both internal and external damage. It is essential to determine and simulate the expansion behaviour of these materials in the laboratory, as well as detect the slow, long-term expansion in real structures. This study measures the expansion of mortar samples during freeze-thaw loading using a high-resolution hand-held 3D laser scanner. The specimens are prepared with fully or partially saturated pore structures through water storage or drying. During freeze-thaw experiments, the specimens are exposed to pure water or a 3\% sodium chloride solution (NaCl). Results show contraction during freezing and subsequent expansion during thawing. Both test solutions exhibit similar expansion behaviour, with differences primarily due to saturation levels. Further investigations are required to explore the changing expansion behaviour caused by increasing microcracking resulting from continuous freeze-thaw cycles. A numerical analysis using a 3D coupled hygro-thermo-mechanical (HTM) model is conducted to examine the freeze-thaw behaviour of the mortar. The model accurately represents the freezing deformation during the freeze-thaw cycle.}, language = {en} } @article{KruegerFischerManoonpongetal., author = {Kr{\"u}ger, Norbert and Fischer, Kerstin and Manoonpong, Poramate and Palinko, Oskar and Bodenhagen, Leon and Baumann, Timo and Kj{\ae}rum, Jens and Rano, Ignacio and Naik, Lakshadeep and Juel, William Kristian and Haarslev, Frederik and Ignasov, Jevgeni and Marchetti, Emanuela and Langedijk, Rosalyn Melissa and Kollakidou, Avgi and Jeppesen, Kasper Camillus and Heidtmann, Conny and Dalgaard, Lars}, title = {The SMOOTH-Robot: A Modular, Interactive Service Robot}, series = {Frontiers in Robotics and AI}, volume = {8}, journal = {Frontiers in Robotics and AI}, publisher = {Frontiers}, doi = {10.3389/frobt.2021.645639}, abstract = {The SMOOTH-robot is a mobile robot that-due to its modularity-combines a relatively low price with the possibility to be used for a large variety of tasks in a wide range of domains. In this article, we demonstrate the potential of the SMOOTH-robot through three use cases, two of which were performed in elderly care homes. The robot is designed so that it can either make itself ready or be quickly changed by staff to perform different tasks. We carefully considered important design parameters such as the appearance, intended and unintended interactions with users, and the technical complexity, in order to achieve high acceptability and a sufficient degree of utilization of the robot. Three demonstrated use cases indicate that such a robot could contribute to an improved work environment, having the potential to free resources of care staff which could be allocated to actual care-giving tasks. Moreover, the SMOOTH-robot can be used in many other domains, as we will also exemplify in this article.}, language = {en} } @article{AlvarezMoretObermeierPohletal., author = {Alvarez Moret, Judit and Obermeier, Tina and Pohl, Fabian and L{\"o}schel, Rainer and K{\"o}lbl, Oliver and Dobler, Barbara}, title = {Second cancer risk after radiation therapy of ependymoma using the flattening filter free irradiation mode of a linear accelerator}, series = {Journal of Applied Clinical Medical Physics}, volume = {19}, journal = {Journal of Applied Clinical Medical Physics}, number = {5}, publisher = {Wiley}, organization = {American Association of Physicists in Medicine}, doi = {10.1002/acm2.12438}, pages = {632 -- 639}, abstract = {Pediatric patients suffering from ependymoma are usually treated with cranial or craniospinal three-dimensional (3D) conformal radiotherapy (3DCRT). Intensity-modulated techniques spare dose to the surrounding tissue, but the risk for second malignancies may be increased due to the increase in low-dose volume. The aim of this study is to investigate if the flattening filter free (FFF) mode allows reducing the risk for second malignancies compared to the mode with flattening filter (FF) for intensity-modulated techniques and to 3DCRT. A reduction of the risk would be advantageous for treating pediatric ependymoma. 3DCRT was compared to intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy (VMAT) with and without flattening filter. Dose-volume histograms (DVHs) were compared to evaluate the plan quality and used to calculate the excess absolute risk (EAR) to develop second cancer in the brain. Dose verification was performed with a two-dimensional (2D) ionization chamber array and the out-of-field dose was measured with an ionization chamber to determine the EAR in peripheral organs. Delivery times were measured. Both VMAT and IMRT achieved similar plan quality in terms of dose sparing in the OAR and higher PTV coverage as compared to 3DCRT. Peripheral dose in low-dose region, which is proportional to the EAR in organs located in this region, for example, gonads, bladder, or bowel, could be significantly reduced using FFF. The lowest peripheral EAR and lowest delivery times were hereby achieved with VMATFFF . The EAR calculated based on DVH in the brain could not be reduced using FFF mode. VMATFFF improved the target coverage and homogeneity and kept the dose in the OAR similar compared to 3DCRT. In addition, delivery times were significantly reduced using VMATFFF . Therefore, for radiotherapy of ependymoma patients, VMATFFF may be considered advantageous for the combination of Elekta Synergy linac and Oncentra External Beam planning system used in this study.}, language = {en} } @article{MikhaeilGadererDawoud, author = {Mikhaeil, Makram and Gaderer, Matthias and Dawoud, Belal}, title = {Experimental Investigation of the Adsorption and Desorption Kinetics on an Open-Structured Asymmetric Plate Heat Exchanger; Matching Between Small-Scale and Full-Scale Results}, series = {Frontiers in Energy Research}, volume = {10}, journal = {Frontiers in Energy Research}, publisher = {Frontiers}, doi = {10.3389/fenrg.2022.818486}, pages = {1 -- 15}, abstract = {This paper introduces the results of an experimental study on the adsorption and desorption kinetics of a commercially available, open-structured asymmetric plate heat exchanger adapted to act as an adsorber/desorber for the application in adsorption heat transformation processes. In addition, a volumetric large temperature jump (V-LTJ) kinetic setup was applied to measure the adsorption and desorption kinetics of a small-scale adsorbent sample prepared dedicatedly to be representative for the adsorbent domain inside the investigated adsorber plate heat exchanger (APHE). All kinetic results of the small-scale adsorbent sample and the APHE were fitted into exponential forms with a single characteristic time constant (τ) with a coefficient of determination (R2) better than 0.9531. A very good matching between the small-scale and full-scale adsorption kinetic measurements was obtained, with an average relative deviation of 12.3\% in the obtained τ-values. In addition, the kinetic data of the small-scale adsorbent sample were utilized for estimating the expected specific instantaneous and moving average powers of the evaporator/condenser heat exchanger. The average relative deviation (ARD) between the moving average specific evaporator powers obtained from the small-scale and the full-scale measurements amounts between 5.4 and 15.1\%.}, language = {en} } @article{CurbachLanderDierksetal., author = {Curbach, Janina and Lander, Jonas and Dierks, Marie-Luise and Grepmeier, Eva-Maria and von Sommoggy, Julia}, title = {How do health professionals translate evidence on early childhood allergy prevention into health literacy-responsive practice?}, series = {BMJ OPEN}, volume = {11}, journal = {BMJ OPEN}, publisher = {BMJ}, doi = {10.1136/bmjopen-2020-047733}, pages = {1 -- 8}, abstract = {Introduction Paediatricians, general practitioners (GPs) and midwives in primary care are important sources of information for parents on early childhood allergy prevention (ECAP). Research has shown that preventive counselling by health professionals can be effective in improving patients' health literacy (HL) and health behaviour. Providing effective advice relies on two factors. First, health professionals need be up-to-date with research evidence on ECAP, to consider popular misconceptions and fears and to translate this knowledge into clear recommendations for parents (knowledge translation). Second, they need to know and apply counselling techniques and create a practice setting which accommodates parental HL needs (health literacy-responsive care). The objective of this study is to explore and assess how German health professionals take up and translate ECAP evidence into appropriate recommendations for parents, how they consider HL in counselling and practice organisation and what barriers and enablers they find in their performance of HL-responsive ECAP. Methods and analysis The study has a sequential mixed-method design, in two phases. In the first phase, qualitative semi-structured expert interviews will be conducted with health professionals (paediatricians, GPs and midwives) at primary care level and professional policy level. Data collection is ongoing until January 2022. In the second phase, based on the qualitative results, a standardised questionnaire will be developed, and pilot-tested in a wider population of German health professionals. The findings of both phases will be integrated. Ethics and dissemination The study has received ethical approval from the Ethics Committee of the University of Regensburg (18-1205-101). The results will be published in international peer-reviewed open access journals and via presentations at scientific conferences. The results will also be shared with German health professionals, decision-makers and potential funders of interventions.}, language = {en} } @article{BerndtMuggliHeckeletal., author = {Berndt, Dominik and Muggli, Josef and Heckel, Robert and Rahiman, Mohd Fuad and Lindner, Matthias and Heinrich, Stephan and Pl{\"o}chinger, Heinz and Schreiner, Rupert}, title = {A Robust Miniaturized Gas Sensor for H₂ and CO₂ Detection Based on the 3ω Method}, series = {Sensors}, volume = {22}, journal = {Sensors}, number = {2}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s22020485}, pages = {1 -- 17}, abstract = {Gas concentration monitoring is essential in industrial or life science areas in order to address safety-relevant or process-related questions. Many of the sensors used in this context are based on the principle of thermal conductivity. The 3ω-method is a very accurate method to determine the thermal properties of materials. It has its origin in the thermal characterization of thin solid films. To date, there have been very few scientific investigations using this method to determine the thermal properties of gases and to apply it to gas measurement technology. In this article, we use two exemplary gases (H2 and CO2) for a systematical investigation of this method in the context of gas analysis. To perform our experiments, we use a robust, reliable sensing element that is already well established in vacuum measurement technology. This helix-shaped thin wire of tungsten exhibits high robustness against chemical and mechanical influences. Our setup features a compact measurement environment, where sensor operation and data acquisition are integrated into a single device. The experimental results show a good agreement with a simplified analytical model and FEM simulations. The sensor exhibits a lower detection limit of 0.62\% in the case of CO2, and only 0.062\% in case the of H2 at an excitation frequency of 1 Hz. This is one of the lowest values reported in literature for thermal conductivity H2 sensors.}, language = {en} } @article{SteiningerGadererSteffensetal., author = {Steininger, Peter and Gaderer, Matthias and Steffens, Oliver and Dawoud, Belal}, title = {Experimental and Numerical Study on the Heat Transfer Characteristics of a Newly-Developed Solar Active Thermal Insulation System}, series = {Buildings}, volume = {11}, journal = {Buildings}, number = {3}, publisher = {MDPI}, doi = {10.3390/buildings11030123}, pages = {1 -- 22}, abstract = {A newly-developed solar active thermal insulation system (SATIS) is introduced with the main objective to accomplish a highly-dependent total solar transmittance on the irradiation angle. SATIS is also designed to obtain the maximum transmittance at a prescribed design irradiation angle and to reduce it remarkably at higher irradiation angles. A purely mineral thermal insulation plaster with micro hollow glass spheres is applied to manufacture the investigated SATIS prototype. Light-conducting elements (LCEs) have been introduced into SATIS and suitable closing elements have been applied. The SATIS prototype has been investigated both experimentally and numerically. It turned out that the contributions of conduction, radiation and convection to the effective thermal conductivity of SATIS, without the closing elements (49 mWmK), amount to 86.2\%, 13.2\% and 0.6\%, respectively. The angle-dependent short-wave radiation exchange within the LCE has been investigated via ray tracing. At the incidence angle of 19\% (design angle), 27\% of the radiation within the LCE is absorbed by the absorber plate, resulting in measured and computed total solar energy transmittances of 11.2\%/11.7\%, respectively. For a typical summer irradiation angle of 60\%, 98\% of the incident radiation is absorbed by the surfaces at the entrance of the LCE. The corresponding total solar energy transmittance amounts to 2.9\%.}, language = {en} } @article{GamischGadererDawoud, author = {Gamisch, Bernd and Gaderer, Matthias and Dawoud, Belal}, title = {On the Development of Thermochemical Hydrogen Storage: An Experimental Study of the Kinetics of the Redox Reactions under Different Operating Conditions}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {4}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app11041623}, pages = {1 -- 15}, abstract = {This work aims at investigating the reduction/oxidation (redox) reaction kinetics on iron oxide pellets under different operating conditions of thermochemical hydrogen storage. In order to reduce the iron oxide pellets (90\% Fe2O3, 10\% stabilizing cement), hydrogen (H2) is applied in different concentrations with nitrogen (N2), as a carrier gas, at temperatures between between 700 ∘C and 900 ∘C, thus simulating the charging phase. The discharge phase is triggered by the flow of a mixture out of steam (H2O) and N2 at different concentrations in the same temperature range, resulting in the oxidizing of the previously reduced pellets. All investigations were carried out in a thermo-gravimetric analyzer (TGA) with a flow rate of 250mL/min. To describe the obtained kinetic results, a simplified analytical model, based on the linear driving force model, was developed. The investigated iron oxide pellets showed a stable redox performance of 23.8\% weight reduction/gain, which corresponds to a volumetric storage density of 2.8kWh/(L bulk), also after the 29 performed redox cycles. Recalling that there is no H2 stored during the storage phase but iron, the introduced hydrogen storage technology is deemed very promising for applications in urban areas as day-night or seasonal storage for green hydrogen.}, language = {en} } @article{PremSindersbergerMonkman, author = {Prem, Nina and Sindersberger, Dirk and Monkman, Gareth J.}, title = {Mini-Extruder for 3D Magnetoactive Polymer Printing}, series = {Advances in Materials Science and Engineering}, journal = {Advances in Materials Science and Engineering}, publisher = {HINDAWI}, doi = {10.1155/2019/8715718}, pages = {1 -- 8}, abstract = {This work describes the development of a new miniature extruder, essential to cavity-free 3D printing of silicone-based smart materials. This makes the 3D printing of magnetoactive and electroactive polymer soft robotic components and devices directly from CAD data possible. The special feature of such an extruder is that it is designed for use with addition-crosslinking RTV-2 silicones, including solid particulate additives. The extruder merges the respective components automatically during extrusion which obviates the need for premixing and vacuum evacuation. Problems associated with inhomogeneities and unwanted cavity production are consequently eliminated. Rheological details necessary to the design, together with some preliminary performance results, are presented.}, language = {en} } @article{DechantFedulovFetisovetal., author = {Dechant, Eduard and Fedulov, Feodor and Fetisov, Leonid Y. and Shamonin (Chamonine), Mikhail}, title = {Bandwidth Widening of Piezoelectric Cantilever Beam Arrays by Mass-Tip Tuning for Low-Frequency Vibration Energy Harvesting}, series = {Applied Science}, volume = {7}, journal = {Applied Science}, number = {12}, publisher = {MDPI}, organization = {MDPI AG}, doi = {10.3390/app7121324}, abstract = {Wireless sensor networks usually rely on internal permanent or rechargeable batteries as a power supply, causing high maintenance efforts. An alternative solution is to supply the entire system by harvesting the ambient energy, for example, by transducing ambient vibrations into electric energy by virtue of the piezoelectric effect. The purpose of this paper is to present a simple engineering approach for the bandwidth optimization of vibration energy harvesting systems comprising multiple piezoelectric cantilevers (PECs). The frequency tuning of a particular cantilever is achieved by changing the tip mass. It is shown that the bandwidth enhancement by mass tuning is limited and requires several PECs with close resonance frequencies. At a fixed frequency detuning between subsequent PECs, the achievable bandwidth shows a saturation behavior as a function of the number of cantilevers used. Since the resonance frequency of each PEC is different, the output voltages at a particular excitation frequency have different amplitudes and phases. A simple power-transfer circuit where several PECs with an individual full wave bridge rectifier are connected in parallel allows one to extract the electrical power close to the theoretical maximum excluding the diode losses. The experiments performed on two- and three-PEC arrays show reasonable agreement with simulations and demonstrate that this power-transfer circuit additionally influences the frequency dependence of the harvested electrical power.}, language = {en} } @article{Diamantidis, author = {Diamantidis, Dimitris}, title = {A Critical View on Environmental and Human Risk Acceptance Criteria}, series = {International Journal of Environmental Science and Development}, volume = {8}, journal = {International Journal of Environmental Science and Development}, number = {1}, doi = {10.18178/ijesd.2017.8.1.921}, pages = {62 -- 66}, abstract = {Natural and technological hazards have a major impact on environmental and human safety. Risk assessment plays an essential role in the risk management of the effects of such hazards. This contribution summarizes first the general formulation of risk depending on two parameters: hazard probability and associated consequences. Problems faced in industrial applications based on the experience of the author are discussed. Risk acceptance criteria for the contributors to risk i.e. human, economic and environment are critically reviewed. Resilience based criteria are also included and conclusions for future developments are provided.}, language = {en} } @article{KreitmeierChashinFetisovetal., author = {Kreitmeier, Florian and Chashin, Dmitri V. and Fetisov, Yuri K. and Fetisov, Leonid Y. and Schulz, Irene and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail}, title = {Nonlinear Magnetoelectric Response of Planar Ferromagnetic-Piezoelectric Structures to Sub-Millisecond Magnetic Pulses}, series = {Sensors}, volume = {12}, journal = {Sensors}, number = {11}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s121114821}, pages = {14821 -- 14837}, abstract = {The magnetoelectric response of bi- and symmetric trilayer composite structures to pulsed magnetic fields is experimentally investigated in detail. The structures comprise layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 µs and amplitudes ranging from 500 Oe to 38 kOe. The time dependence of the resulting voltage is presented and explained by theoretical estimations. Appearance of voltage oscillations with frequencies much larger than the reciprocal pulse length is observed for sufficiently large amplitudes (~1-10 kOe) of the magnetic-field pulse. The origin of these oscillations is the excitation of bending and planar acoustic oscillations in the structures. Dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated by digital signal processing and compared with those obtained by the method of harmonic field modulation. The results are of interest for developing magnetoelectric sensors of pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures.}, language = {en} } @article{ApelsmeierGleixnerMayeretal., author = {Apelsmeier, Andreas and Gleixner, Ramona and Mayer, Matthias and Shamonin (Chamonine), Mikhail and Schmauss, Bernhard}, title = {Intensity referencing in an extrinsic optical fiber temperature sensor}, series = {Procedia Engineering}, volume = {5}, journal = {Procedia Engineering}, publisher = {Elsevier}, doi = {10.1016/j.proeng.2010.09.301}, pages = {1095 -- 1098}, abstract = {Optical fiber sensors based on intensity measurement require some form of intensity referencing to avoid errors arising from parasitic losses. Known techniques of referencing such as balanced bridge, divided beam systems or two-wavelength referencing are not suitable for low-cost applications since they use relatively complicated optical components such as multiple LED sources, couplers, filters etc. In this work a novel method of referencing in an extrinsic optical fiber sensor system utilizing temperature dependence of absorption edge in a semiconductor crystal is described. The sensor system comprises a single LED source and no optical fiber junctions. The emission spectrum of an LED depends on its temperature. The reference is provided by controlling the temperature of an LED source and transmission measurements with different emission spectra. The entire process is controlled by a microprocessor unit. Performance of a sensor system is investigated and it is shown that the losses in connectors may be compensated for.}, language = {en} } @article{MonkmanSindersbergerPremetal., author = {Monkman, Gareth J. and Sindersberger, Dirk and Prem, Nina and Szecsey, Tamara}, title = {Smart Stiction}, series = {Robotics \& Automation Engineering Journal}, volume = {4}, journal = {Robotics \& Automation Engineering Journal}, number = {4}, publisher = {Juniper Publishers}, doi = {10.19080/RAEJ.2019.04.555641}, abstract = {Soft robotics could loosely be described as the engineering science of expanded dexterity through controllable flexibility. The exploitation of controllable compliance through the judicious choice of soft flexible members, as opposed to a finite number of rigid kinematic joints, can result in greater dexterity without compromising simplicity. One example is the replacement of segmented mechanical legs with simple compliant material eruciform prolegs. To achieve this in robotics, without introducing additional mechanical joints, mobile surfaces with switchable coefficients of friction is essential. This paper explains how, using silicone based smart materials, the rapid alternation between kinematic and static friction (stiction) may be achieved.}, language = {en} }