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Suche nach „[F: Elektrotechnik und Medientechnik]“ hat 1223 Publikationen gefunden
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    NachhaltigF: Elektrotechnik und Medientechnik

    Zeitschriftenartikel

    Christoph Metzke, Fabian Kühnel, Jonas Weber, Günther Benstetter

    Scanning Thermal Microscopy of Ultrathin Films: Numerical Studies Regarding Cantilever Displacement, Thermal Contact Areas, Heat Fluxes, and Heat Distribution

    Nanomaterials, vol. 11, no. 2

    2021

    DOI: 10.3390/nano11020491

    Abstract anzeigen

    New micro- and nanoscale devices require electrically isolating materials with specific thermal properties. One option to characterize these thermal properties is the atomic force microscopy (AFM)-based scanning thermal microscopy (SThM) technique. It enables qualitative mapping of local thermal conductivities of ultrathin films. To fully understand and correctly interpret the results of practical SThM measurements, it is essential to have detailed knowledge about the heat transfer process between the probe and the sample. However, little can be found in the literature so far. Therefore, this work focuses on theoretical SThM studies of ultrathin films with anisotropic thermal properties such as hexagonal boron nitride (h-BN) and compares the results with a bulk silicon (Si) sample. Energy fluxes from the probe to the sample between 0.6 µW and 126.8 µW are found for different cases with a tip radius of approximately 300 nm. A present thermal interface resistance (TIR) between bulk Si and ultrathin h-BN on top can fully suppress a further heat penetration. The time until heat propagation within the sample is stationary is found to be below 1 µs, which may justify higher tip velocities in practical SThM investigations of up to 20 µms−1. It is also demonstrated that there is almost no influence of convection and radiation, whereas a possible TIR between probe and sample must be considered.

    NachhaltigF: Elektrotechnik und Medientechnik

    Zeitschriftenartikel

    C. Niu, Y. Zhang, Y. Cui, X. Li, W. Liu, W. Ni, H. Fan, N. Lu, Günther Benstetter, G. Lei, D. Liu

    Effect of temperature on the growth and surface bursting of He nano-bubbles in W under fusion-relevant He ion irradiations

    Fusion Engineering and Design, vol. 163, no. Available online 26 December 2020

    2020

    DOI: 10.1016/j.fusengdes.2020.112159

    Abstract anzeigen

    Under fusion-relevant He+ irradiations, the W surface temperature is one of the most important parameters for controlling the fuzz growth over the W divertor targets, which is associated with the surface bursting of He nano-bubbles. Using He reaction rate model in W, we investigate the effect of temperature on the growth and surface bursting of He nano-bubbles under low-energy (100 eV) and large-flux (∼1022/m2⋅s) He+ irradiations. Increasing the irradiation temperature from 750 to 2500 K leads to a significant change in both the radius of He nano-bubbles and He retention. At an elevated temperature, He solute atoms prefer to rapidly diffuse into He nano-bubbles, thus affecting their concentration, growth and surface bursting. The decrease in He retention is attributed to an increase in the hop rate of solute He atoms in the W top layer, resulting in the significant He release from the W surface. The radius and density of He nano-bubbles calculated by our model are consistent with our experimental observation.

    NachhaltigF: Elektrotechnik und Medientechnik

    Zeitschriftenartikel

    W. Ni, Y. Zhang, Y. Cui, C. Niu, L. Liu, H. Fan, Günther Benstetter, G. Lei, D. Liu

    The effect of fusion-relevant He ion flux on the evolution of He nano-bubbles in W

    Plasma Physics and Controlled Fusion, vol. 62, no. 6

    2020

    DOI: 10.1088/1361-6587/ab8242

    Abstract anzeigen

    Based on a He reaction rate model in W, we have analyzed the effect of fusion-relevant He+ flux on the evolution and surface bursting of He nano-bubbles in W. The concentrations of solute He atoms, trapped He atoms, and He nano-bubbles, and the radius of He nano-bubbles have been obtained as a function of depth, He+ dose, and He+ flux. He retentions in W are also calculated as the function of He+ dose and flux. Our modeling shows that the He+ flux varying from 5.0 × 1018 to 5.0 × 1024 m−2centerdots−1 significantly affects the concentration of solute He atoms diffusing in W and trapped He atoms, the evolution of He nano-bubbles, and He retention in W. Both the concentration and radius of He nano-bubbles in W show the dependence on He+ flux, and their surface bursting leads to an increase ($\Delta {A_{b - Burst}}$) in the W surface area, thus the growth of W nano-fuzz. When He+ flux increases 5.0 × 1018 to 5.0 × 1024m−2centerdots−1, the bursting rate of He nano-bubbles is greatly reduced, accompanied by an increase in $\Delta {A_{b - Burst}}$. However, $\Delta {A_{b - Burst}}$ is less dependent on the fusion-relevant He+ flux varying from 9.0 × 1020 to 1.6 × 1022m−2centerdots−1, which is consistent with the measured W nano-fuzz growth by He/D2 plasmas.

    DigitalF: Elektrotechnik und MedientechnikS: TSZ Weißenburg

    Beitrag (Sammelband oder Tagungsband)

    Alireza Tajafari Sahebi, Amir Samiee, László Juhász

    MRAC Implementation for Electric Throttle Valve

    Proceedings of the 2020 10th International Conference on Advanced Computer Information Technologies (ACIT) [September 6-8, 2020; Deggendorf]

    2020

    DOI: 10.1109/ACIT49673.2020.9208929

    Abstract anzeigen

    Design, implementation and testing of a model reference adaptive controller for an electric throttle valve are presented. An important step by design an adaptive controller is to find an adaptation mechanism. For this purpose, we employed the Lyapunov stability theory. The main challenge in this project originates from a certain term in the updating rules. This term contains the angular velocity, which is not measurable directly. Numerical differentiation of the measured angular position yields a noisy signal. To overcome this problem, we used a non-ideal derivative method. The use of a non-linear state observer based on extended Kalman filter could significantly enhance the control quality. This task is currently in progress.

    F: Elektrotechnik und Medientechnik

    Beitrag (Sammelband oder Tagungsband)

    Günter Keller

    Electromagnetic Compatibility of Switched-Mode Power Supplies

    IEEE International Conference on Industrial Technology (ICIT 2020)

    2020

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Vortrag

    Fabian Kühnel, Christoph Metzke, Günther Benstetter

    Thermal conductivity measurements of thin films using 3ω method

    7. Tag der Forschung, Deggendorf

    2020

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Vortrag

    Christoph Metzke, Fabian Kühnel, Günther Benstetter

    Thermal characterization of thin films using FEM simulations

    7. Tag der Forschung, Deggendorf

    2020

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    H. Fan, Y. Zhang, D. Liu, C. Niu, L. Liu, W. Ni, Y. Xia, Z. Bi, Günther Benstetter, G. Lei

    Tensile stress-driven cracking of W fuzz over W crystal under fusion-relevant He ion irradiations

    Nuclear Fusion, vol. 60, no. 4

    2020

    DOI: 10.1088/1741-4326/ab71bb

    Abstract anzeigen

    Although W fuzz is formed in the divertor region of the fusion reactor, no theory may clearly explain the W fuzz growth mechanism. In this study, we observe the growth process of W fuzz over W crystal under ITER-relevant He ion irradiations. We propose the tensile stress-driven cracking of nano-structured fuzz during the initial growth of W fuzz. We demonstrate that the existence of tensile stress is due to the swelling of He nano-bubbles in the fuzz. After this cracking, the W fuzz breaks away from the planar network and grows over the W surface, where the micro-stress in the W surface layer acts as the driving force.

    F: Elektrotechnik und Medientechnik

    Zeitschriftenartikel

    H. Heckelmüller, F. Kendl, Gerhard Krump

    TDR Einzahlwert zur Charakterisierung der dynamischen Oberbausteifigkeit

    ZEVrail - Zeitschrift für das gesamte System Bahn, vol. 144, no. Mai, pp. 190-194

    2020

    Abstract anzeigen

    Der Schallmesswagen (SMW) der DB Systemtechnik prüft den akustischen Zustand des Oberbaus und wird vor allem zur Überprüfung von Streckenabschnitten mit der Maßnahme „Besonders überwachtes Gleis“ (BüG) verwendet. Zusätzlich wird der SMW zur Qualitätskontrolle und Abnahme des akustischen Schienenschleifens eingesetzt. Falls ein BüG-Abschnitt nicht vom SMW befahren werden kann, gilt seit 2001 die Ersatzmaßnahme RMF-BüG. Dieses Verfahren soll die Messaufgaben des SMW durch kontinuierliche Rauheitsmessungen beider Schienen ersatzweise übernehmen können. Beim RMF-BüG-Verfahren wurde zur Berechnung des SMW-Pegels ausschließlich die Schienenrauheit berücksichtigt. Anhand einer Vielzahl von Messungen konnte gezeigt werden, dass das Rollgeräusch des SMW signifikant ebenfalls von der Gleisabklingrate (Track Decay Rate TDR) abhängig ist. Das vorgestellte Verfahren zeigt die Verwendung des Einzahlwertes der Schienenrauheit LλCA und des Einzahlwertes der TDR L TDR zur Bestimmung des SMW-Pegels.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    Christoph Metzke, Werner Frammelsberger, Jonas Weber, Fabian Kühnel, K. Zhu, M. Lanza, Günther Benstetter

    On the Limits of Scanning Thermal Microscopy of Ultrathin Films

    Materials, vol. 13, no. 3

    2020

    DOI: 10.3390/ma13030518

    Abstract anzeigen

    Heat transfer processes in micro- and nanoscale devices have become more and more important during the last decades. Scanning thermal microscopy (SThM) is an atomic force microscopy (AFM) based method for analyzing local thermal conductivities of layers with thicknesses in the range of several nm to µm. In this work, we investigate ultrathin films of hexagonal boron nitride (h-BN), copper iodide in zincblende structure (γ-CuI) and some test sample structures fabricated of silicon (Si) and silicon dioxide (SiO2) using SThM. Specifically, we analyze and discuss the influence of the sample topography, the touching angle between probe tip and sample, and the probe tip temperature on the acquired results. In essence, our findings indicate that SThM measurements include artefacts that are not associated with the thermal properties of the film under investigation. We discuss possible ways of influence, as well as the magnitudes involved. Furthermore, we suggest necessary measuring conditions that make qualitative SThM measurements of ultrathin films of h-BN with thicknesses at or below 23 nm possible.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    W. Ni, L. Liu, Y. Zhang, C. Niu, H. Fan, G. Song, D. Liu, Günther Benstetter, G. Lei

    Effect of intermittent He/D ion irradiations on W nano-fuzz growth over W targets

    Vacuum, vol. 173, no. March

    2020

    DOI: 10.1016/j.vacuum.2019.109146

    Abstract anzeigen

    The intermittent He/D ion irradiations of polycrystalline W have been performed at the ion energy of 50 eV by changing the time of the single irradiations and the irradiation temperature. All irradiated W specimens have been observed by scanning electron microscopy, and the effect of intermittent He/D ion irradiations on the W fuzz growth has been analyzed. The W fuzz growth over W targets does not show the clear dependence on the intermittent He/D ion irradiations, where the He/D ion fluence of the single irradiations typically varies from 5.0 × 1024 to 2.5 × 1025/m2. However, a slight change in the W surface temperature during the single He ion irradiations significantly affects the W fuzz growth rate. Analysis indicates that W fuzz growth is significantly affected by the total He ion fluence varying from 5.0 × 1024 to 5.0 × 1025/m2 and the irradiation temperature varying from 1100 to 1450 K. This current study will play a crucial role in understanding the W fuzz growth under the periodic He/D ion irradiations of W divertor in fusion reactors, such as ELMs.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Beitrag (Sammelband oder Tagungsband)

    Christoph Metzke, Günther Benstetter

    Thermische Charakterisierung ultradünner Schichten

    Forschungsbericht 2018/2019 der Technischen Hochschule Deggendorf, Deggendorf

    2019

    NachhaltigF: Elektrotechnik und Medientechnik

    Zeitschriftenartikel

    Jens Schanze

    Nachhaltigkeitsthemen in der studentischen TV-Sendung "doschauher.tv" der TH Deggendorf

    Bavarian Journal of Applied Sciences (Rubrik Schlaglichter), vol. 5, no. 1, pp. 482-485

    2019

    DOI: 10.25929/bjas.v5i1.72

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Vortrag

    Christoph Metzke, Günther Benstetter, Werner Frammelsberger, Jonas Weber, Fabian Kühnel

    Temperature dependent investigation of hexagonal boron nitride films using scanning thermal microscopy

    Poster presentation

    6th Nano Today Conference 2019, Lisbon, Portugal

    2019

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    Z. Bi, D. Liu, Y. Zhang, L. Liu, Y. Xia, Y. Hong, H. Fan, Günther Benstetter, G. Lei, L. Yan

    The evolution of He nanobubbles in tungsten under fusion-relevant He ion irradiation conditions

    Nuclear Fusion, vol. 59, no. 8

    2019

    DOI: 10.1088/1741-4326/ab2472

    Abstract anzeigen

    He-induced W nanofuzz growth over the W divertor target is one of the main limiting factors affecting the current design and development of fusion reactors. In this paper, based on He reaction rate model in W, we simulate the growth and evolution of He nanobubbles during W nanofuzz formation under fusion-relevant He+ irradiation conditions. Our modeling unveils the existence of He nanobubble-enriched W surface layer (<10 nm), formed due to the He diffusion in W crystal into defect sites. At an elevated temperature, the growth of He bubbles in the W surface layer prevents He atoms diffusing into the deep layer (>10 nm). The formation of W nanofuzz at the surface is attributed to surface bursting of high-density He bubbles with their radius of ~4 nm, and an increase in the surface area of irradiated W. Our findings have been well confirmed by the experimental measurements.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    W. Ni, L. Liu, Y. Zhang, H. Fan, G. Song, D. Liu, Günther Benstetter, G. Lei

    Mass loss of pure W, W-Re alloys, and oxide dispersed W under ITER-relevant He ion irradiations

    Journal of Nuclear Materials, vol. 527

    2019

    DOI: 10.1016/j.jnucmat.2019.151800

    Abstract anzeigen

    In this study, polycrystalline W, W-Re alloys, and La2O3 and Y2O3 dispersion-strengthened W have been irradiated by our large-power materials irradiation experimental system (LP-MIES) at the irradiation temperature of 1360–1460 K. Our measurements show that the W nano-fuzz layer which is < 5.2 μm thick has been formed over all the specimens exposed to the low-energy (50 or 100 eV) and high-flux (1.37 × 1022–1.62 × 1022 ions/m2⋅s) He+ irradiations. The mass loss of the fuzz layer almost linearly increases with the He+ fluence, which does not show any dependence on the thickness of fuzz layer varying from 1.1 to 5.2 μm La2O3 and Y2O3 dispersions into W significantly suppress the growth of W fuzz, indicating that He diffusion and the evolution of He nano-bubbles in the near-surface can be significantly influenced due to the dispersion. After He+ (100 eV) irradiation at He+ fluence of 5.83 × 1026/m2, the mass loss of 0.1 vol% - 1.0 vol% La2O3-dispersed W is about 20% lower than the one of the pure W, and the La2O3 dispersed W exhibits the best erosion resistance among various W material grades. Our analysis indicates that both the surface sputtering of W fuzz by energetic ions and surface bursting of He nano-bubbles can be responsible for the mass loss of W under ITER-relevant He+ irradiations.

    NachhaltigF: Elektrotechnik und MedientechnikI: IQMA

    Zeitschriftenartikel

    C. Wen, X. Jing, F. Hitzel, C. Pan, Günther Benstetter, M. Lanza

    In Situ Observation of Current Generation in ZnO Nanowire Based Nanogenerators Using a CAFM Integrated into an SEM

    ACS Applied Materials & Interfaces, vol. 11, no. 17, pp. 15183-15188

    2019

    DOI: 10.1021/acsami.9b00447

    Abstract anzeigen

    In this work, we monitor in situ the movement of ZnO piezoelectric nanowires by using a conductive atomic force microscope integrated into a scanning electron microscope. This setup allows seeing the bending of the nanowires and simultaneously measuring the currents generated. We conclude that the currents generated not only come from piezoelectric effect, but also from contact potential and triboelectric effect. These contributions have been ignored in all previous reports in this field, meaning that the power conversion efficiency of these devices may have been systematically overestimated. Our study helps to clarify the working mechanism of piezoelectric nanogenerators based on ZnO nanowires.

    F: Elektrotechnik und Medientechnik

    Beitrag (Sammelband oder Tagungsband)

    E. Hasenberger, Gerhard Krump, M. Schneider

    Evaluating Binaural Simulations of a Premium Automotive Sound System

    Paper No. 3

    Proceedings of the 2019 AES International Conference on Automotive Audio

    2019

    F: Elektrotechnik und Medientechnik

    Beitrag (Sammelband oder Tagungsband)

    R. Beinstingel, Gerhard Krump

    Untersuchungen zur tieffrequenten Wiedergabe bei dreidimensionaler Beschallung

    Fortschritte der Akustik - DAGA 2019, Berlin

    2019

    DigitalF: Elektrotechnik und MedientechnikS: TSZ Weißenburg

    Beitrag (Sammelband oder Tagungsband)

    László Juhász, Amir Samiee, W. Engelbrecht

    XCP Service Integration for Model-Based, Automatic Production Code Generation

    Proceedings of IEEE EUROCON 2019 -18th International Conference on Smart Technologies

    2019

    DOI: 10.1109/EUROCON.2019.8861774

    Abstract anzeigen

    Automated, model-based production code generation is widely used in the development and testing of electronic control units (ECUs). During ECU commissioning, extensive tests of the implemented control algorithms are required. Knowledge of the internal values and states of the ECU software are essential for verifying the correct software functionality by means of complex control algorithms. Calibration and measurement services make it possible to observe the ECU-internal memory values associated with the variables originating from the function model. Furthermore, the final adjustment of control parameters in the production ECU can be performed by means of calibration services. For these reasons, calibration and measurement through service integration is widely applied in both the automotive industry and other industrial fields. Integrating measurement and calibration services is therefore an important task for engineers working with model-based control development and, particularly, ECU production code integration. This paper describes an example integration of the Universal Measurement and Calibration Protocol (XCP) for model-based automatic code generation. The application used for the service integration is the commercially available Motor Control Education Kit (MEDKit) from Emerge-Engineering and dSPACE GmbH. The model-based automatic code generation is performed using the production code generator dSPACE TargetLink. The integration of the XCP on CAN protocol is completed in the scope of student projects. The upgraded MEDKit demonstrator will be used for education purposes in the Deggendorf Institute of Technology.