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    NachhaltigTC Freyung

    Zeitschriftenartikel

    Roland Zink, Javier Valdés, Jane Wuth

    Prioritizing the Chicken or Egg? Electric Vehicle Purchase and Charging Infrastructure Subsidies in Germany

    Politics and Governance, vol. 8, no. 3, pp. 185-198

    2020

    DOI: 10.17645/pag.v8i3.3025

    Abstract anzeigen

    To meet current targets for greenhouse gas emissions in Europe, emissions, especially those originating from the road transport sector, need to be reduced. Plans are to achieve this goal by substituting fossil fuel vehicles with electric vehicles (EVs). This article first discusses conceptually the impact of an increasing share of EVs on the electricity grid and suitable locations for charging stations with examples from a Case Study in Lower Bavaria. Secondly, the impact of purchase subsidies on EV purchases in Germany, a high-income country characterized by an important automotive industry and an increasing share of private vehicles is examined. To achieve this, yearly information on EV purchases were analyzed by applying the Synthetic Control Method. Combining data from different sources including the European Alternative Fuels Observatory, Eurostat, and the European Automobile Manufacturers' Association, an overall picture was developed. Results indicate a difference between private, semi-public, and public charging infrastructures. Its spatial distribution does not correspond to a specific development strategy. Moreover, EV subsidies have a limited effect in Germany when controlling for market size. Limiting the discussion to a trade-off between subsidizing infrastructures or EV purchases obviates the multidimensionality of the problem as neither of them may be sufficient to accelerate the transition per se. Furthermore, if electricity provided for EVs comes mainly from fossil carriers, the changes in the road transport sector will not yield the expected emission reductions. The transition towards renewables is directly intertwined with the effects of EVs on emission reductions in the road transport sector.

    DigitalNachhaltigTC Grafenau

    Zeitschriftenartikel

    S. Goisser, S. Wittmann, Michael Fernandes, H. Mempel, C. Ulrichs

    Comparison of colorimeter and different portable food-scanners for non-destructive prediction of lycopene content in tomato fruit

    Postharvest Biology and Technology, vol. 167, no. September

    2020

    DOI: 10.1016/j.postharvbio.2020.111232

    Abstract anzeigen

    Lycopene, the red colored carotenoid in tomatoes, has various health benefits for humans due to its capability of scavenging free radicals. Traditionally, the quantification of lycopene requires an elaborate extraction process combined with HPLC analysis within the laboratory. Recent studies focused simpler methods for determining lycopene and utilized spectroscopic measurement methods. The aim of this study was to compare non-destructive methods for the prediction of lycopene by using color values from colorimeter measurements and Vis/NIR spectra recorded with three commercially available and portable Vis/NIR spectrometers, so called food-scanners. Tomatoes of five different ripening stages (green to red) as well as tomatoes stored up to 22 days after harvest were used for modeling. After measurement of color values and collection of Vis/NIR spectra the corresponding lycopene content was analyzed spectrophotometrically. Applying exponential regression models yielded very good prediction of lycopene for color values L*, a*, a*/b* and the tomato color index of 0.94, 0.90, 0.90 and 0.91, respectively. Color value b* was not a suitable predictor for lycopene content, whereas the (a*/b*)² value had the best linear fit of 0.87. In comparison to color measurements, the cross-validated prediction models developed for all three food-scanners had coefficients of determination (r²CV) ranging from 0.92 to 0.96. Food-scanners also can be used for additional measurements of internal fruit quality, and therefore have great potential for fruit quality assessment by measuring a multitude of important fruit traits in one single scan.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Simon Killinger, Johannes Liebl, Rolf Rascher

    First steps towards an automated polishing process chain using one robot

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2564840

    Abstract anzeigen

    Manufacturing precision optics is a complex process chain, which requires many operations on different machines. This is combined with operator-dependent steps such as manual cleaning, loading and measuring. In order to realize this process chain on a smaller shop area and to achieve a higher level of automation we build an operator-independent polishing cell. In this cell, an ABB robot serves as the actuator handling the workpiece. We positioned the robot in the center of the polishing cell to operate several workstations, so the whole process chain works with one single actuator. This arrangement allows a smaller and cheaper system, since no additional handling is required.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Michael Benisch, O. Fähnle, Rolf Rascher, Werner Bogner

    Force and pressure analysis during overarm polishing

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2564903

    Abstract anzeigen

    The Preston-equation implies, that, besides the relative speed υrel and a specific constant KP, the pressure p plays a significant role for the removal rate when polishing an optical component. This paper demonstrates a possibility for a qualitative evaluation of the pressure distribution before the polishing process. A pressure-sensitive foil is used as a gauge for pressure measurement. The effectiveness of this measuring method is explained. Specific weaknesses and limitations in the use of these foils are discussed. A method for an integrated evaluation of the pressure on different spots of the polishing pad is proposed at the end of the paper.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    M. Pohl, R. Börret, Olga Kukso, Rolf Rascher

    Mid spatial frequency error prevention strategies for the grinding process

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2565261

    Abstract anzeigen

    This research is focused on the link between manufacturing parameters and the resulting mid-spatial frequency error in the manufacturing process of precision optics. The goal is to understand the generation mechanisms of mid-spatial frequency errors and avoid their appearance in the manufacturing process. Also, a simulation which is able to predict the resulting mid spatial frequency error from a manufacturing process is desired.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Jessica Stelzl, Christine Wünsche, S. Höfer

    Influencing factors for a continuous wave UV-laser component

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2564916

    Abstract anzeigen

    During the development of an optical system, one comes to the point where you have to build the optically active element into a mechanical device that becomes part of the system. At this point you come across the well-known question that it is not only necessary to consider and ensure the quality of the individual element. It is also important to look at the entire component in order to identify potential influencing factors on the performance of the optical system. At the beginning of a two-year project at Technologiecampus Teisnach the polishing process of a nonlinear crystal as the crucial component of the optical system was being explored. This system is designed to create continuous wave laser beams in the deep UV range. The crystal has to be embedded between two prisms. Roughness and shape of the crystal is ensured via the polishing process which alone has many influencing factors and was examined at the beginning of the project. The quality of the crystal can be as good as it can be, but if the contacting prisms do not fit, the whole prism-coupled device will become unusable in the overall optical laser system. The performance of the laser can only be achieved by harmonizing all elements of the PCD and the PCD itself into the laser set-up. In the current phase of the project this question will be dealt with. The prism-coupled device is split up into its individual parts, which are the nonlinear crystal, the prisms as optical auxiliary components, micro screws and mechanical support. Going through the requirements to the properties of the crystal and their limitations, the influence of the PCD on the optical performance of the crystal is presented. Here, the main focus is placed on the mode of fixing the crystal between the prisms and on putting the stack of crystal and prisms in the laser beam. The influencing factors between the crystal, the prisms and the method of fixing the PCD are described.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Michael Wagner, Gerald Fütterer

    Computer-aided beam path generation and assessment for Stevick-Paul telescopes

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2564852

    Abstract anzeigen

    At Deggendorf Institute of Technology a student project is currently under way to build a Stevick-Paul telescope for astrophotography. An important step in the overall development procedure of each telescope is the design of a beam-path and ensuring its suitability under optical and engineering aspects. The students performed this process in a sequential manner by using several different computer programs (e.g. MATLAB, Zemax, Creo Parametric). To accelerate the beam path design process, a Python program to automate the major part of the design process with minimum human supervision was created. The input data of the python program consists of ranges of the desired characteristics of the Stevick-Paul telescope, such as focal lengths, primary mirror diameters and tilts etc., mirror thickness and mount geometries, as well as the specific type of camera. After setting the input, the program creates 2D cross-sections of beam paths according to the formulas of D. Stevick and may introduce a flat fold mirror to reduce the overall system size as well as improve the accessibility of the focus plane. The subsequent assessment routine checks against the susceptibility for stray light and performs a complex analysis of the available installation space to ensure sufficient mechanical tolerances. In this way, collisions between mirrors, mounts and cameras are avoided and obstructions of the beam path are prevented. At any stage, the program can produce graphical representations of the beam paths. In this paper the computer-aided design of a telescope beam path with a focal length of 2400 mm is demonstrated. During development of the software, a subset of folded Stevick-Paul telescopes, in which certain components are parallel, was found. This subset may be useful to simplify the alignment procedure. In conclusion, further refinement of the software is necessary, although the program is already a useful aid for certain aspects when creating a beam path design.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Olga Kukso, Rolf Rascher, M. Pohl, R. Börret

    On the metrology and analysis of MSF error

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2566251

    Abstract anzeigen

    The aim of our research was to study middle spatial frequency errors (MSFE) on optical surfaces. We investigate the surfaces after manufacturing processes to find out the main affecting factors and to choose the proper processing parameters to minimize the size of the errors. To find an appropriate parameter window we have to be able not only to define the factors, which lead to MSFE, but also to analyze the change of the error after next following production steps.

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    M. Jung, Christian J. Trum, Beate Schmidbauer, E. Willenborg, Rolf Rascher

    Non-ablative removal of sub surface damages in ground optical glass substrates by controlled melting of thin surface layers using CO2-laser radiation

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2564801

    Abstract anzeigen

    The form generation of optical surfaces by grinding and mechanical polishing results in small sub surface damages in the form of micro cracks that conventionally have to be removed by further removal of the damaged surface layers. In order to reduce process time and material cost non-ablative methods for removal of micro cracks are desired. Utilising the low optical penetration depths of less than 10 μm for CO2-laser radiation in glass, the laser energy can be used to heat up and melt thin surface layers. Using a 1.5 kW CO2-laser, a quasi-line focus formed by a scanner unit and a constant feed speed, it is possible to close all micro cracks present in the rough grinded test surfaces (max. SSD-depth ~ 63 μm), while achieving a process time of less than 2 seconds for a Ø 30 mm N-BK7 lens, respectively 7.5 seconds for fused silica. With a Sa as low as 50 nm and low distortion from the original shape the surfaces can directly be conventionally polished, further reducing the process chain complexity.

    NachhaltigTC Weißenburg

    Zeitschriftenartikel

    Wang, J., Dmitry Rychkov, Q. Nguyen, Gerhard, R.

    The influence of orthophosphoric-acid surface modification on charge-storage enhancement in polypropylene electrets

    Journal of Applied Physics, vol. 128, no. 3

    2020

    DOI: 10.1063/5.0013805

    Abstract anzeigen

    Bipolar electrets from polypropylene (PP) are essential, e.g., in electret air filters and in cellular-foam ferroelectrets. Therefore, the mechanism of surface-charge stability enhancement on PP electrets via orthophosphoric-acid surface treatment is investigated in detail. It is shown that the significant charge-stability enhancement can be mainly attributed to deeper surface traps originating from deposited chemicals and topographic features on the modified surfaces. Thermally stimulated discharge of chemically treated and non-treated PP films with different surface-charge densities is used to test the limits of the newly formed deep traps in terms of the capacity for hosting surface charges. When the initial surface-charge density is very high, more charges are forced into shallower original traps on the surface or in the bulk of the treated PP samples, reducing the effect of the deeper surface traps brought by the surface modification. The well-known crossover phenomenon (of the surface-charge decay curves) has been observed between modified PP electrets charged to ±2 kV and to ±3  kV. Acoustically probed charge distributions in the thickness direction of PP electrets at different stages of thermal discharging indicate that the deep surface trapping sites may have preference for negative charges, resulting in the observed asymmetric charge stability of the modified PP films.

    NachhaltigElektrotechnik und MedientechnikIQMA

    Vortrag

    Fabian Kühnel, Christoph Metzke, Günther Benstetter

    Thermal conductivity measurements of thin films using 3ω method

    7. Tag der Forschung, Deggendorf

    2020

    NachhaltigElektrotechnik und MedientechnikIQMA

    Vortrag

    Christoph Metzke, Fabian Kühnel, Günther Benstetter

    Thermal characterization of thin films using FEM simulations

    7. Tag der Forschung, Deggendorf

    2020

    DigitalNachhaltigFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    Gabriel Herl, Jochen Hiller, A. Maier

    Scanning trajectory optimisation using a quantitative Tuybased local quality estimation for robot-based X-ray computed tomography

    Nondestructive Testing and Evaluation, vol. (Published 21 June 2020), no. 6

    2020

    DOI: 10.1080/10589759.2020.1774579

    Abstract anzeigen

    Robotic CT systems allow complex scanning trajectories. This work presents a workflow to automatically calculate optimised scanning trajectories for robotic CT systems. In particular, as a local quality estimation, this work introduces a quantitative measure to quantify local reconstruction quality based on the Tuy conditions. The proposed method is tested in two summation experiments using an STL model of a motorcycle. In both experiments, a trajectory is calculated using a quantitative Tuy-based local quality estimation and the reconstruction result is then compared to reconstructions using conventional scanning trajectories. The comparison results indicate that the proposed approach automatically finds trajectories that enable 3D reconstructions with high image quality using much less projection data, which allows a significant reduction of scanning time.

    DigitalNachhaltigFraunhofer AWZ CTMTMaschinenbau und Mechatronik

    Zeitschriftenartikel

    A. Stock, Gabriel Herl, T. Sauer, Jochen Hiller

    Edge-preserving compression of CT scans using wavelets

    Insight - Non-Destructive Testing and Condition Monitoring (The British Institute of Non-Destructive Testing), vol. 62, no. 6, pp. 345-351

    2020

    DOI: 10.1784/insi.2020.62.6.345

    Abstract anzeigen

    This work addresses the subject of efficient storage of computed tomography (CT) data with an emphasis on the quality of surfaces. Industrial dimensional metrology often requires high measurement accuracy and it is shown that this is retained using wavelet-based compression methods. The applied techniques include a tensor product wavelet transform and soft wavelet shrinkage. In these tests, performed on real objects, dimensional CT measurements of compressed and uncompressed volumes were compared. The necessary storage space was reduced significantly with a negligible loss of accuracy. The storage space required for a multi-sphere phantom was decreased to 4.7% (from 638 MB to 30 MB), with an average deviation below 1 μm from the original volume.

    DigitalNachhaltigExtern

    Vortrag

    T. Heberholz, Andrey Prihodovsky, M. Nowottnick

    Einfluss eines abnormalen (CuNi)6Sn5/(NiCu)3Sn4-Schichtwachstums auf die Robustheit von bleifreien Zinn-Silber-Basis-Lotstellen bei Temperaturen oberhalb von 175 °C

    Fachtagung/Konferenz EBL 2020 - Elektronische Baugruppen und Leiterplatten, Fellbach

    2020

    DigitalNachhaltigExtern

    Zeitschriftenartikel

    Anton Schmailzl, Johannes Käsbauer, J. Martan, P. Honnerová, F. Schäfer, Maximilian Fichtl, T. Lehrer, L. Prušáková, J. Tesař, J. Skála, M. Honner

    Measurement of core temperature through semi-transparent polyamide 6 using scanner-integrated pyrometer in laser welding

    International Journal of Heat and Mass Transfer, vol. 146, no. January

    2020

    DOI: 10.1016/j.ijheatmasstransfer.2019.118814

    Abstract anzeigen

    Predicting the core temperature during welding is an ambitious aim in many research works. In this work, a 3D-scanner with integrated pyrometer is characterized and used to measure the temperature during quasi-simultaneous laser transmission welding of polyamide 6. However, due to welding in an overlap configuration, the heat radiation emitted from the joining zone of a laser transmission weld has to pass through the upper polymer, which is itself a semi-transparent emitter. Therefore, the spectral filtering of the heat radiation in the upper polymer is taken into account by calibrating the pyrometer for the measurement task. Thermal process simulations are performed to compare the temperature field with the measured temperature signal. The absorption coefficients of the polymers are measured, in order to get precise results from the computation. The temperature signals during welding are in good agreement with the computed mean temperature inside the detection spot, located in the joining area. This is also true for varying laser power, laser beam diameter and the carbon black content in the lower polymer. Both, the computed mean temperature and the temperature signal are representing the core temperature. In order to evaluate the spatial sensitivity of the measurement system, the emitted heat radiation from both polymers is calculated on basis of the computed temperature field. Hereby it is found, that more than 90 percent of the detected heat radiation comes from the joining area, which is a crucial information for contact-free temperature measurement tasks on semi-transparent polymers.

    DigitalNachhaltigExtern

    Vortrag

    Johannes Käsbauer, Anton Schmailzl, T. Loose, S. Hierl

    Potentials of the EFG-Method for Modeling Quasi-Simultaneous Laser Transmission Welding Considering the Melt Flow

    Simulationsforum 2019 Schweißen und Wärmebehandlung, Weimar

    2020

    DigitalNachhaltigExtern

    Vortrag

    Johannes Käsbauer, Anton Schmailzl, T. Loose, S. Hierl

    Thermo-Mechanical Modeling of Quasi-Simultaneous Laser Transmission Welding using LS-DYNA with Focus on Accuracy of Heat Input Calculation

    Technology Day 2020 - Plastics on the test rig, Traboch, Österreich

    2020

    DigitalNachhaltigExtern

    Zeitschriftenartikel

    Johannes Käsbauer, Anton Schmailzl, J. Prehm, T. Loose, S. Hierl

    Simulation of Quasi-Simultaneous Laser Transmission Welding of Plastics: Optimization of Material Parameters in Broad Temperature Range

    [Accepted for publication]

    Procedia CIRP

    2020

    NachhaltigAngewandte Naturwissenschaften und WirtschaftsingenieurwesenIPH Teisnach

    Beitrag (Sammelband oder Tagungsband)

    Sebastian Sitzberger, Johannes Liebl, Christian J. Trum, Rolf Rascher

    Concept of a two-part clamping system for lenses in optical metrology

    Proceedings of SPIE 11478 (Seventh European Seminar on Precision Optics Manufacturing [8 July 2020; Teisnach]), Bellingham, WA, USA

    2020

    DOI: 10.1117/12.2566547

    Abstract anzeigen

    The developed concept represents a universally applicable clamping system designed to fit in any measuring machine with any measuring principle. The design ensures that, as long as the lens remains clamped, the measurement results are reproducible. Form errors due to tension remain constant across all measuring and processing steps. The version presented in this paper was developed especially for small lenses in the diameter range up to 40 mm. On the one hand, the design allows for fast measurement of loose lenses. On the other hand, the device can also be used for measurement comparisons, since lenses can also be mounted permanently. In the following, the concept and first results of measurement tests are presented.