@article{PalombaNowakDawoudetal., author = {Palomba, Valeria and Nowak, Sebastian and Dawoud, Belal and Frazzica, Andrea}, title = {Dynamic modelling of Adsorption systems: a comprehensive calibrated dataset for heat pump and storage applications}, series = {Journal of energy storage}, volume = {33}, journal = {Journal of energy storage}, publisher = {Elsevier}, doi = {10.1016/j.est.2020.102148}, abstract = {The growing efforts for the development of clean and efficient energy systems require the use of a multi-disciplinary approach and the integration of multiple generation appliances. Among the fields that can be considered enabling technologies, adsorption systems for air conditioning and thermal energy storages, are constantly increasing their maturity. However, for a proper design and integration of such systems, there is the need for a simulation framework that is reliable and computationally convenient. In the present paper, the implementation of a dynamic model for adsorption systems is presented, which includes different components (adsorber, phase changer, sorption materials) and is structured as a library. Modelica language and the commercial software Dymola (R) are used for the analysis. Data for different heat exchangers and working pairs are calibrated using experimental results and the calibrated model is subsequently used for the design of an adsorber based on a plate heat exchanger for thermal energy storage applications. The results proved that the model is fast and can reproduce experimental results with good accuracy, thus being a useful tool for the design and optimization of the different components of sorption systems.}, language = {en} } @article{GradNadammalSchultheissetal., author = {Grad, Marius and Nadammal, Naresh and Schultheiss, Ulrich and Lulla, Philipp and Noster, Ulf}, title = {An Integrative Experimental Approach to Design Optimization and Removal Strategies of Supporting Structures Used during L-PBF of SS316L Aortic Stents}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {19}, publisher = {MPDL}, doi = {10.3390/app11199176}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-25612}, pages = {1 -- 22}, abstract = {One of the fundamental challenges in L-PBF of filigree geometries, such as aortic stents used in biomedical applications, is the requirement for a robust yet easily removable support structure that allows each component to be successfully fabricated without distortion. To solve this challenge, an integrative experimental approach was attempted in the present study by identifying an optimal support structure design and an optimized support removal strategy for this design. The specimens were manufactured using four different support structure designs based on the geometry exposed to the laser beam during the L-PBF. Support removal procedures included sand blasting (SB), glass bead blasting (GB), and electrochemical polishing (ECP). The two best-performing designs (line and cross) were chosen due to shorter lead times and lower material consumption. As an additional factor that indicates a stable design, the breaking load requirement to remove the support structures was determined. A modified line support with a 145° included angle was shown to be the best support structure design in terms of breaking load, material consumption, and manufacturing time. All three procedures were used to ensure residue-free support removal for this modified line support design, with ECP proving to be the most effective.}, language = {en} } @article{KoenigGuertler, author = {Koenig, Eric and Guertler, Katherine}, title = {One Size Does Not Fit All: Individuality and Perceptions of Improvement and Satisfaction Among TE Students}, series = {English Teaching \& Learning}, volume = {45}, journal = {English Teaching \& Learning}, number = {3}, publisher = {Springer Nature}, doi = {10.1007/s42321-021-00076-4}, pages = {303 -- 324}, abstract = {Academic self-regulation is a key factor for motivation and learning achievement. Yet with the large range of individual factors, this is not a one-size-fits-all proposition. This study of L2 Technical English students at two German universities explored learners' expectations and motivations, in particular regarding self-regulation and self-efficacy via the individual's time investment in self-led study. In an initial survey, learners (N=1646) reported on their English skill levels and anticipated learning habits. Complementarily, the retrospective survey investigated learners' (N=796) actual behavior during the course, their perceptions of language skill improvement, and their satisfaction. The initial survey indicates a clear understanding that time investment in self-regulated study will lead to greater improvement, an outcome confirmed in the retrospective survey. Additionally, students who invested more time in their coursework were more satisfied with their achievement, although most learners acknowledge they should have studied more. The results verify that learners recognize the nexus between self-regulation and language skill improvement, yet university students are not satisfied with their capacity to self-regulate their language learning strategies. While differences in students' skill levels and academic self-efficacy result in divergent degrees of progress, students of all types report benefits to their language skills when motivated to self-regulated study.}, language = {en} } @article{SnarskiiZorinetsShamoninChamonineetal., author = {Snarskii, Andrei A. and Zorinets, Denis and Shamonin (Chamonine), Mikhail and Kalita, Viktor M.}, title = {Theoretical method for calculation of effective properties of composite materials with reconfigurable microstructure}, series = {Physica A: Statistical Mechanics and its Applications}, volume = {535}, journal = {Physica A: Statistical Mechanics and its Applications}, number = {December}, publisher = {Elsevier}, doi = {10.1016/j.physa.2019.122467}, abstract = {We propose a theoretical approach for calculating effective electric and magnetic properties of composites, with field dependent restructuring of the filler. The theory combines the effective medium approximation, extended to a field-dependent (variable) percolation threshold, with an approximate treatment of the nonlinearity of material properties. Theoretical results are compared with experiments on magnetorheological elastomers, which in the context of investigated phenomena are often called magnetoactive elastomers (MAEs). In MAEs with soft polymer matrices, the mutual arrangement of inclusions changes in an applied magnetic field. This reorganization of the microstructure leads to unconventionally large changes of electrical and magnetic properties. The obtained theoretical results describe observed phenomena in MAEs well. For the magnetodielectric effect, qualitative agreement between theory and experiment is demonstrated. In the case of magnetic permeability, quantitative agreement is achieved. The theoretical approach presented can be useful for the development of field-controlled smart materials and design of intelligent structures on their basis, because the field dependence of physical properties can be predicted. (C) 2019 Elsevier B.V. All rights reserved.}, language = {en} } @article{HansenHoeblerPurretal., author = {Hansen, B. and Hoebler, Michael and Purr, Stephan and Meinhardt, J. and Merklein, Marion}, title = {Basics for inline measurement of tribological conditions in series production of car body parts}, series = {IOP Conference Series: Materials Science and Engineering}, volume = {651}, journal = {IOP Conference Series: Materials Science and Engineering}, publisher = {IOP Publishing}, doi = {10.1088/1757-899x/651/1/012050}, abstract = {The quality of car body parts in series production is strongly dependent on the tribological behavior. Fluctuating material properties such as the sheet roughness and the amount of lubricant have an influence on the forming process. On the basis of large amounts of data it is possible to investigate the friction behavior in series production and to make process adjustments if required. Therefore, inline measurement systems have a great potential to detect the sheet roughness during the cutting process of blanks in the coil line. Furthermore, contactless systems are advantageous as they do not damage the surface. Nevertheless, the optical measuring is influenced by the lubricant layer on top of the surface. Therefore, the previously unknown impact of the lubricant on the measuring result is investigated. Within this study, stationary optical roughness measurements have been conducted using different amounts of lubricant on hot-dip galvanized EDT steel. The results demonstrate the influence of different amounts of lubricant on the sheet roughness measurement. Hence, it is possible to correct the inline measuring results and gain knowledge of fluctuating surface roughness. In addition, strip drawing test has been carried out to investigate the effect of fluctuating tribological conditions.}, language = {en} } @article{LenkDuttgeFlatauetal., author = {Lenk, Christian and Duttge, Gunnar and Flatau, Laura and Frommeld, Debora and Poser, Wolfgang and Reitt, Markus and Schulze, Thomas and Weber, Alexandra and Zoll, Barbara}, title = {A look into the future? Patients' and health care staff's perception and evaluation of genetic information and the right not to know}, series = {American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics}, volume = {180}, journal = {American journal of medical genetics. Part B, Neuropsychiatric genetics : the official publication of the International Society of Psychiatric Genetics}, number = {8}, publisher = {Wiley}, doi = {10.1002/ajmg.b.32751}, pages = {576 -- 588}, abstract = {The progress of medical genetics leads to a significant increase in genetic knowledge and a vast expansion of genetic diagnostics. However, it is still unknown how these changes will be integrated into medical practice and how they will change patients' and healthy persons' perception and evaluation of genetic diagnoses and genetic knowledge. Therefore, we carried out a comprehensive questionnaire survey with more than 500 patients, clients seeking genetic counseling, health care staff, and healthy persons (N = 523). The questionnaire survey covered detailed questions on the value of genetic diagnoses for the different groups of study participants, the right to know or not to know genetic diagnoses, possible differences between genetic and other medical diagnoses, and the practical use and implications of genetic knowledge with a special focus on hereditary neuropsychiatric diseases. A huge majority of the participants (90.7\%) stated to have a right to learn every aspect of her or his genetic make-up. Similarly, study participants showed high interest (81.8\%) in incidental health care findings-independent of whether the diseases are treatable or not. One can derive from the data outcome that study participants did not follow the implications of a "genetic exceptionalism" and often considered genetic findings as equivalent in relation to other medical diagnoses.}, language = {en} } @article{SchwanzerSchillingerMieslingeretal., author = {Schwanzer, Peter and Schillinger, Maximilian and Mieslinger, Johann and Walter, Stefanie and Hagen, Gunter and Maerkl, Susanne and Haft, Gerhard and Dietrich, Markus and Moos, Ralf and Gaderer, Matthias and Rabl, Hans-Peter}, title = {A Synthetic Ash-Loading Method for Gasoline Particulate Filters with Active Oil Injection}, series = {SAR International Journal of Engines}, volume = {14}, journal = {SAR International Journal of Engines}, number = {4}, publisher = {SAE International}, issn = {1946-3936}, doi = {10.4271/03-14-04-0029}, pages = {493 -- 506}, abstract = {To reduce particulate emissions, the use of particulate filters in diesel engines is meanwhile state of the art, while the integration of such systems in gasoline engines is now also necessary in order to comply with today's regulations. Over its lifetime, a gasoline particulate filter (GPF) collects ash components of fuel, lubrication oil, and materials originating from the catalytic coating and from engine abrasion. In the development and application process, synthetic ashing from GPFs is challenging. The ash of the lubrication oil can be increased in various ways, like oil-doped fuel, a separate oil burner, or changes in the piston-cylinder system of the engine. However, these methods show major disadvantages. For this reason, an improved approach is presented in this study, which allows a quick response to changes in combustion (e.g., engine knocking) and producing ash, which is more realistic due to its primary particle size and the density of ash plugs, in a shorter time. Therefore, an approach to accelerate ash loading by active oil injection using a multi-point injection (MPI) system is introduced. With the help of this methodology, an ashing capacity of 1.21 g/h is implemented, which is a high rate compared to other investigations. The primary particle size (evaluated by means of a transmission electron microscope), is in the same size range as those detected at the full-load curve during regular operation. A computer tomographic (CT) analysis of the incinerated particulate filter also shows that a very high density of ash plugs can be realized, which has also been found in the literature for real applications. In addition, with the help of a mass spectrometer (MS) and an intermediate weighing of the particulate filter, the current ash loading of the GPF could be determined with an accuracy of 1\%.}, language = {en} } @article{FeldRochGaboretal., author = {Feld, Sebastian and Roch, Christoph and Gabor, Thomas and Seidel, Christian and Neukart, Florian and Galter, Isabella and Mauerer, Wolfgang and Linnhoff-Popien, Claudia}, title = {A Hybrid Solution Method for the Capacitated Vehicle Routing Problem Using a Quantum Annealer}, series = {Frontiers in ICT}, volume = {6}, journal = {Frontiers in ICT}, publisher = {Frontiers}, doi = {10.3389/fict.2019.00013}, pages = {1 -- 13}, abstract = {he Capacitated Vehicle Routing Problem (CVRP) is an NP-optimization problem (NPO) that has been of great interest for decades for both, science and industry. The CVRP is a variant of the vehicle routing problem characterized by capacity constrained vehicles. The aim is to plan tours for vehicles to supply a given number of customers as efficiently as possible. The problem is the combinatorial explosion of possible solutions, which increases superexponentially with the number of customers. Classical solutions provide good approximations to the globally optimal solution. D-Wave's quantum annealer is a machine designed to solve optimization problems. This machine uses quantum effects to speed up computation time compared to classic computers. The problem on solving the CVRP on the quantum annealer is the particular formulation of the optimization problem. For this, it has to be mapped onto a quadratic unconstrained binary optimization (QUBO) problem. Complex optimization problems such as the CVRP can be translated to smaller subproblems and thus enable a sequential solution of the partitioned problem. This work presents a quantum-classic hybrid solution method for the CVRP. It clarifies whether the implementation of such a method pays off in comparison to existing classical solution methods regarding computation time and solution quality. Several approaches to solving the CVRP are elaborated, the arising problems are discussed, and the results are evaluated in terms of solution quality and computation time.}, language = {en} } @article{XueKeimParedesetal., author = {Xue, Lufeng and Keim, Vincent and Paredes, Marcelo and Nonn, Aida and Wierzbicki, Tomasz}, title = {Anisotropic effects on crack propagation in pressurized line pipes under running ductile fracture scenarios}, series = {Engineering fracture mechanics}, volume = {249}, journal = {Engineering fracture mechanics}, publisher = {Elsevier}, doi = {10.1016/j.engfracmech.2021.107748}, abstract = {The current analyses present results of running ductile fracture propagation in high strength X100 line pipe steels under the influence of anisotropy. Mechanical anisotropy is commonly available in pipe products as a result of the manufacturing process, especially, those subjected to hot/cold-worked deformation. The outcomes of the present analyses show that its effect on the behavior of running ductile fracture in cracked pipes undergoing depressurization is meaningful. For instance, the Crack-Tip Opening Angle (CTOA) not only exhibits a strong dependence to the pipe's diameter size, but also to the material's anisotropy nature when compared to a hypothetical isotropic material. Moreover, laboratory scale tests such as those performed on Battelle Drop Weight Tear (BDWT) samples provide useful information about initiation of ductile crack propagation when the anisotropy features are taken into account in the material description.}, language = {en} } @article{ThemaBauerSterner, author = {Thema, Martin and Bauer, Franz and Sterner, Michael}, title = {Power-to-Gas: Electrolysis and methanation status review}, series = {Renewable and Sustainable Energy Reviews}, volume = {112}, journal = {Renewable and Sustainable Energy Reviews}, number = {7}, publisher = {Elsevier}, doi = {10.1016/j.rser.2019.06.030}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26238}, pages = {775 -- 787}, abstract = {This review gives a worldwide overview on Power-to-Gas projects producing hydrogen or renewable substitute natural gas focusing projects in central Europe. It deepens and completes the content of previous reviews by including hitherto unreviewed projects and by combining project names with details such as plant location. It is based on data from 153 completed, recent and planned projects since 1988 which were evaluated with regards to plant allocation, installed power development, plant size, shares and amounts of hydrogen or substitute natural gas producing examinations and product utilization phases. Cost development for electrolysis and carbon dioxide methanation was analyzed and a projection until 2030 is given with an outlook to 2050. The results show substantial cost reductions for electrolysis as well as for methanation during the recent years and a further price decline to less than 500 euro per kilowatt electric power input for both technologies until 2050 is estimated if cost projection follows the current trend. Most of the projects examined are located in Germany, Denmark, the United States of America and Canada. Following an exponential global trend to increase installed power, today's Power-to-Gas applications are operated at about 39 megawatt. Hydrogen and substitute natural gas were investigated on equal terms concerning the number of projects.}, language = {en} } @article{LindnerPipaKarpenetal., author = {Lindner, Matthias and Pipa, Andrei V. and Karpen, Norbert and Hink, R{\"u}diger and Berndt, Dominik and Foest, R{\"u}diger and Bonaccurso, Elmar and Weichwald, Robert and Friedberger, Alois and Caspari, Ralf and Brandenburg, Ronny and Schreiner, Rupert}, title = {Icing Mitigation by MEMS-Fabricated Surface Dielectric Barrier Discharge}, series = {Applied Sciences}, volume = {11}, journal = {Applied Sciences}, number = {23}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/app112311106}, pages = {1 -- 17}, abstract = {Avoiding ice accumulation on aerodynamic components is of enormous importance to flight safety. Novel approaches utilizing surface dielectric barrier discharges (SDBDs) are expected to be more efficient and effective than conventional solutions for preventing ice accretion on aerodynamic components. In this work, the realization of SDBDs based on thin-film substrates by means of micro-electro-mechanical-systems (MEMS) technology is presented. The anti-icing performance of the MEMS SDBDs is presented and compared to SDBDs manufactured by printed circuit board (PCB) technology. It was observed that the 35 mu m thick electrodes of the PCB SDBDs favor surface icing with an initial accumulation of supercooled water droplets at the electrode impact edges. This effect was not observed for 0.3 mu m thick MEMS-fabricated electrodes indicating a clear advantage for MEMS-technology SDBDs for anti-icing applications. Titanium was identified as the most suitable material for MEMS electrodes. In addition, an optimization of the MEMS-SDBDs with respect to the dielectric materials as well as SDBD design is discussed.}, language = {en} } @article{LovšinBrandlGlavanetal., author = {Lovšin, Matija and Brandl, Dominik and Glavan, Gašper and Belyaeva, Inna A. and Cmok, Luka and Coga, Lucija and Kalin, Mitjan and Shamonin (Chamonine), Mikhail and Drevenšek-Olenik, Irena}, title = {Reconfigurable Surface Micropatterns Based on the Magnetic Field-Induced Shape Memory Effect in Magnetoactive Elastomers}, series = {Polymers}, volume = {13}, journal = {Polymers}, number = {24}, publisher = {MDPI}, doi = {10.3390/polym13244422}, abstract = {A surface relief grating with a period of 30 mu m is embossed onto the surface of magnetoactive elastomer (MAE) samples in the presence of a moderate magnetic field of about 180 mT. The grating, which is represented as a set of parallel stripes with two different amplitude reflectivity coefficients, is detected via diffraction of a laser beam in the reflection configuration. Due to the magnetic-field-induced plasticity effect, the grating persists on the MAE surface for at least 90 h if the magnetic field remains present. When the magnetic field is removed, the diffraction efficiency vanishes in a few minutes. The described effect is much more pronounced in MAE samples with larger content of iron filler (80 wt\%) than in the samples with lower content of iron filler (70 wt\%). A simple theoretical model is proposed to describe the observed dependence of the diffraction efficiency on the applied magnetic field. Possible applications of MAEs as magnetically reconfigurable diffractive optical elements are discussed. It is proposed that the described experimental method can be used as a convenient tool for investigations of the dynamics of magnetically induced plasticity of MAEs on the micrometer scale.}, language = {en} } @article{SternerSpecht, author = {Sterner, Michael and Specht, Michael}, title = {Power-to-Gas and Power-to-X-The History and Results of Developing a New Storage Concept}, series = {Energies}, volume = {14}, journal = {Energies}, number = {20}, publisher = {MDPI}, doi = {10.3390/en14206594}, url = {http://nbn-resolving.de/urn:nbn:de:bvb:898-opus4-26202}, abstract = {Germany's energy transition, known as 'Energiewende', was always very progressive. However, it came technically to a halt at the question of large-scale, seasonal energy storage for wind and solar, which was not available. At the end of the 2000s, we combined our knowledge of both electrical and process engineering, imitated nature by copying photosynthesis and developed Power-to-Gas by combining water electrolysis with CO2-methanation to convert water and CO2 together with wind and solar power to synthetic natural gas. Storing green energy by coupling the electricity with the gas sector using its vast TWh-scale storage facility was the solution for the biggest energy problem of our time. This was the first concept that created the term 'sector coupling' or 'sectoral integration'. We first implemented demo sites, presented our work in research, industry and ministries, and applied it in many macroeconomic studies. It was an initial idea that inspired others to rethink electricity as well as eFuels as an energy source and energy carrier. We developed the concept further to include Power-to-Liquid, Power-to-Chemicals and other ways to 'convert' electricity into molecules and climate-neutral feedstocks, and named it 'Power-to-X'at the beginning of the 2010s.}, language = {en} } @article{HaugLochnerHuber, author = {Haug, Sonja and Lochner, Susanne and Huber, Dominik}, title = {Methodological Aspects of a Quantitative and Qualitative Survey of Asylum Seekers in Germany}, series = {mda - methods data analyses}, volume = {13}, journal = {mda - methods data analyses}, number = {2}, publisher = {GESIS - Leibniz-Institut f{\"u}r Sozialwissenschaften}, doi = {10.12758/mda.2019.02}, pages = {321 -- 340}, abstract = {This field report presents and discusses methodological issues and challenges encountered in a mixed-methods research project on asylum seekers in Bavaria, Germany. It documents the research design of, and field experiences in, a quantitative survey based on a quota sampling procedure and a qualitative study, both of which were conducted in collective accommodation for asylum seekers at selected locations in that federal state. Standardized PAPI multiple-topic questionnaires were completed by asylum seekers from Syria, Afghanistan, Eritrea, and Iraq (N = 779); most of the questionnaires were self-administered. In addition, 12 qualitative face-to-face biographical interviews were conducted in order to gain an in-depth understanding of attitudes and experiences of asylum seekers. This report focuses on the following aspects: the use of gatekeepers to facilitate participant recruitment; sampling procedures; the involvement of interpreters in the data collection process; response bias and response behaviors among asylum seekers; and the experiences gained from data collection in collective accommodation for asylum seekers.}, language = {en} } @article{KahlKrauseHackenbergetal., author = {Kahl, Matthias and Krause, Veronika and Hackenberg, Rudolf and Ul Haq, Anwar and Horn, Anton and Jacobsen, Hans-Arno and Kriechbaumer, Thomas and Petzenhauser, Michael and Shamonin (Chamonine), Mikhail and Udalzow, Anton}, title = {Measurement system and dataset for in-depth analysis of appliance energy consumption in industrial environment}, series = {tm - Technisches Messen}, volume = {86}, journal = {tm - Technisches Messen}, number = {1}, publisher = {De Gruyter}, doi = {10.1515/teme-2018-0038}, pages = {1 -- 13}, abstract = {To support a rational and efficient use of electrical energy in residential and industrial environments, Non-Intrusive Load Monitoring (NILM) provides several techniques to identify state and power consumption profiles of connected appliances. Design requirements for such systems include a low hardware and installations costs for residential, reliability and high-availability for industrial purposes, while keeping invasive interventions into the electrical infrastructure to a minimum. This work introduces a reference hardware setup that allows an in depth analysis of electrical energy consumption in industrial environments. To identify appliances and their consumption profile, appropriate identification algorithms are developed by the NILM community. To enable an evaluation of these algorithms on industrial appliances, we introduce the Laboratory-measured IndustriaL Appliance Characteristics (LILAC) dataset: 1302 measurements from one, two, and three concurrently running appliances of 15 appliance types, measured with the introduced testbed. To allow in-depth appliance consumption analysis, measurements were carried out with a sampling rate of 50 kHz and 16-bit amplitude resolution for voltage and current signals. We show in experiments that signal signatures, contained in the measurement data, allows one to distinguish the single measured electrical appliances with a baseline machine learning approach of nearly 100\% accuracy.}, language = {en} } @article{SnarskiiPodlasovShamoninChamonine, author = {Snarskii, Andrei A. and Podlasov, Sergii and Shamonin (Chamonine), Mikhail}, title = {Isotropic inertia tensor without symmetry of mass distribution}, series = {American Journal of Physics}, volume = {89}, journal = {American Journal of Physics}, number = {10}, publisher = {AIP Publishing}, doi = {10.1119/10.0005416}, pages = {916 -- 920}, abstract = {Conventional calculations of the inertia tensor in undergraduate physics course are usually done for highly symmetrical bodies. Students might therefore get the impression that the moment of inertia about any axis through the center of mass is the same only for bodies with the highest degree of symmetry relative to this point, e.g., for spheres. A simple, seemingly counterintuitive example is presented, showing that the moment of inertia of a non-regular body, here an assembly of material points, can be the same about any axis passing through its center of mass.}, language = {en} } @article{SchwanzerRablLodersetal., author = {Schwanzer, Peter and Rabl, Hans-Peter and Loders, S. and Seifert, P. and Himmelstoss, S. and Gaderer, Matthias}, title = {Difference in the Tailpipe Particle Number by Consideration of Sub-23-nm Particles for Different Injection Settings of a GDI Engine}, series = {Emission control science and technology}, volume = {5}, journal = {Emission control science and technology}, number = {1}, publisher = {Springer Nature}, doi = {10.1007/s40825-019-0114-1}, pages = {7 -- 22}, abstract = {The purpose of this study was to investigate the characteristic of nanoparticles under consideration of sub-23-nm particles from a 1.8-l direct injection (DI) gasoline engine under stoichiometric air/fuel conditions in the exhaust gas system. For future CO2 challenges, the usage of DI-instead of port fuel injection (PFI)-gasoline engines is unavoidable. Therefore, a state of the art particle management program-particle number (PN) system, the Horiba SPCS (2100) with an integrated CPC (condensation particle counter), was recalibrated from a 50\% cutoff (D-50\%) at 23 nm down to a cutoff at 10 nm and the PCRF (particle concentration reduction factor) for sizes smaller than 23 nm was checked. Two different modal points, out of a representative Real Driving Emission (RDE) cycle, were investigated with both calibrations, D-50\%=10 nm and D-50\%=23 nm. For these different load points, the fuel pressure (FUP) and the start of injection (SOI) were varied, to represent the difference in the structure and the ratio conc((10 nm))/conc((23 nm)) of the nanoparticle emissions. The particle characterization includes the particle number (PN), the particle size distribution (PSD), and the particle mass (PM). The particle number was measured with Horiba SPCS (2100). The particle size distribution was analyzed with a Grimm differential mobility analyzer (DMA) in combination with a Faraday cup electrometer (FCE). Micro Soot and Pegasor were used to determine the PM, and an optical characterization was done with a 120-kV Phillips CM12 transmission electron microscope (TEM). The position of all particle measurement systems was downstream the three-way catalyst (TWC). The results of this investigation showed that a higher injection pressure decreases the PN (without consideration of sub-23-nm particles) in general. The ratio conc((10 nm))/conc((23 nm)) was therefore higher, because smaller particles, especially ash particles, were less reduced from the FUP. This means higher FUP tends to a higher ratio. For the SOI, the main reasons of the ratio differences were explained by an encroachment between the injection jet and the piston, the valve and the wall.}, language = {en} } @article{VerezBorriCrespoetal., author = {V{\´e}rez, David and Borri, Emiliano and Crespo, Alicia and Zsembinszki, Gabriel and Dawoud, Belal and Cabeza, Luisa F.}, title = {Experimental Study of a Small-Size Vacuum Insulated Water Tank for Building Applications}, series = {Sustainability}, volume = {13}, journal = {Sustainability}, number = {10}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/su13105329}, pages = {1 -- 11}, abstract = {Insulation of thermal energy storage tanks is fundamental to reduce heat losses and to achieve high energy storage efficiency. Although water tanks were extensively studied in the literature, the enhancement of the insulation quality is often overlooked. The use of vacuum insulation has the potential to significantly reduce heat losses without affecting the dimension of the storage system. This paper shows for the first time the results of the heat losses tests done for a 0.535 m3 water tank for residential building applications built with a double wall vacuum insulation. The different tests show that the rate of heat losses strictly depends on the temperature distribution inside the tank at the beginning of the experiment. Compared to a conventional water tank insulated with conventional materials, the U-value of the lateral surface was reduced by almost three times (from 1.05 W/K·m2 to 0.38 W/K·m2) using vacuum insulation. However, the bottom part, which is usually used to place the support parts and the piping, is the critical design part of those tanks acting as a thermal bridge with the ambient and enhancing heat losses.}, language = {en} } @article{SteiningerGadererDawoud, author = {Steininger, Peter and Gaderer, Matthias and Dawoud, Belal}, title = {Assessment of the Annual Transmission Heat Loss Reduction of a Refurbished Existing Building with an Advanced Solar Selective Thermal Insulation System}, series = {Sustainability}, volume = {13}, journal = {Sustainability}, number = {13}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/su13137336}, pages = {1 -- 19}, abstract = {A numerical parameter sensitivity analysis of the design parameters of the recently published solar selective thermal insulation system (SATIS) has been carried out to enhance its thermal and optical properties. It turned out that the insulation properties of SATIS can be effectively improved by reducing the length of the glass closure element. Increasing the area share of the light conducting elements (LCEs) and decreasing their length-to-diameter (L/D) ratio were identified as key parameters in order to increase the solar gain. Two SATIS variants were compared with the same wall insulation without SATIS in a yearly energetic performance assessment. The SATIS variant with 10 mm length of the closure element, 44.2\% area share of LCE, as well as front and rear diameters of 12 mm/9 mm shows an 11.8\% lower transmission heat loss over the heating period than the wall insulation without SATIS. A new methodology was developed to enable the implementation of the computed solar gains of SATIS in 1D simulation tools. The result is a radiant heat flow map for integration as a heat source in 1D simulation models. A comparison between the 1D and 3D models of the inside wall heat fluxes showed an integral yearly agreement of 98\%.}, language = {en} } @article{SindersbergerPremMonkman, author = {Sindersberger, Dirk and Prem, Nina and Monkman, Gareth J.}, title = {Structure formation in low concentration magnetoactive polymers}, series = {AIP advances}, volume = {9}, journal = {AIP advances}, number = {3}, publisher = {AIP Publishing}, doi = {10.1063/1.5079997}, abstract = {This paper concerns recent research into the autonomous formation of micro-structures in low carbonyl iron powder (CIP) concentration magneto active polymers (MAP). Higher concentrations of CIP show an isotropic distribution of magnetic filler throughout the entire sample, while autonomous structure formation is possible at mass concentrations lower than 3\%. The formation of micro-toroids commences as CIP concentration approaches 1\% wt. Further development of coherent rings with a defined order follow as CIP concentrations increase toward 2\% wt, whilst exceeding 3\% wt leads to the same isotropic distribution found in higher concentration MAP. Structured samples containing between 1\% wt and 3\% wt CIP were investigated using X-Ray tomography where solitary structures could clearly be observed. The ring structures represent microinductivities whose geometries can be manipulated during fabrication. In addition, these structures are magnetic field sensitive. This is not only relevant to applications in the GHz and THz areas but recent research has revealed implications for optical, thermal, acoustic and even chemical MAP sensors. (C) 2019 Author(s).}, language = {en} }