Performance evaluation of capacitive based force sensor for electroencephalography head caps. - In: International journal on robotics, automation and sciences, ISSN 2682-860X, Bd. 2 (2020), S. 4-8
https://doi.org/10.33093/ijoras.2020.2.1
Methods for the determination of parameters for the electrical warning of persons :
Techniken zur Bestimmung von Parametern für die elektrische Personenwarnung. - In: Arbeitsmedizin, Sozialmedizin, Umweltmedizin, ISSN 0944-6052, Bd. 55 (2020), 10, S. 645-652
Investigation of the reaction kinetics of chromium(III) ions with carboxylic acids in aqueous solutions and the associated effects on chromium deposition. - In: Journal of the Electrochemical Society, ISSN 1945-7111, Bd. 167 (2020), 16, 162509, insges. 8 S.
Electroplated chromium is an important industrial coating. Both in the decorative and functional field, research is being carried out to develop trivalent chromium electrolytes. In this work, the interaction between CrIII ions and carboxylic acids (malonic acid, malic acid, oxalic acid and glycolic acid) is investigated. The use of carboxylic acids to improve the current efficiency in trivalent chromium plating baths has been known for a long time. But the thermodynamics and kinetics of the associated complexing reactions are not well understood. It is shown that the complexes form at different rates depending on the acid and its concentration and have a varying influence on chromium deposition. For the development of a technical bath, care must be taken to ensure that the molar ratios between chromium and carboxylic acids can be controlled. This is possible with the HPLC method presented here.
https://doi.org/10.1149/1945-7111/abd1f4
Electrogravimetry and structural properties of thin silicon layers deposited in sulfolane and ionic liquid electrolytes. - In: ACS applied materials & interfaces, ISSN 1944-8252, Bd. 12 (2020), 51, S. 57526-57538
Potentiostatic deposition of silicon is performed in sulfolane (SL) and ionic liquid (IL) electrolytes. Electrochemical quartz crystal microbalance with damping monitoring (EQCM-D) is used as main analytical tool for the characterization of the reduction process. The apparent molar mass (Mapp) is applied for in situ estimation of the layer contamination. By means of this approach, appropriate electrolyte composition and substrate type are selected to optimize the structural properties of the layers. The application of SL electrolyte results in silicon deposition with higher efficiency compared to the IL 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, [BMP][TFSI]. This has been associated with the instability of the IL in the presence of silicon tetrachloride and the enhanced incorporation of IL decomposition products into the growing silicon deposit. X-ray photoelectron spectroscopy (XPS) analysis supports the results about the layer composition, as suggested from the microgravimetric experiments. Attention has been given to the impact of practically relevant substrates (i.e., Cu, Ni, and vitreous carbon) on the reduction process. An effective deposition can be carried out on the metal electrodes in both electrolytes due to accelerated reaction kinetics for these types of substrates. However, on vitreous carbon (VC), a successful reduction of SiCl4 can only be accomplished in the IL, while the electroreduction process in SL is dominated by the decomposition of the electrolyte. For short deposition times, the scanning electron microscopy (SEM) images display rough morphologies in the nanometer range, which evolve further to structures with increased length scale of the surface roughness. The development of a rough interface during deposition, resulting in QCM damping at advanced stages of the process, is interpreted by a model accounting for the resistive force caused by the interaction of the liquid with a nonuniform layer interface. By using this approach, the individual contributions of the surface roughness and viscoelastic effects to the measured damping values are estimated.
https://doi.org/10.1021/acsami.0c14694
Scanning probe microscopy - from surfaces to single atoms. - In: Encyclopedia of applied physics, (2020), S. 1-39
This article highlights the important role of scanning tunneling and atomic force microscopy in modern surface science experiments. Imaging with atomic resolution, manipulation of matter atom by atom, spectroscopy of confined electrons, molecular vibrational quanta, surface phonons, singleatom spin flips, and singlemolecule fluorescence photons are some of the diverse applications of the microscopes. The impact of the actual atomic or molecular termination of the tip is emphasized. A variety of examples presents the state of the art in quantum physics of surfaces and interfaces and demonstrates that scanning probe techniques significantly contribute to the understanding of matter at the atomic scale.
https://doi.org/10.1002/3527600434.eap914
Energy-resolved secondary-electron emission of candidate beam screen materials for electron cloud mitigation at the Large Hadron Collider. - In: Physical review accelerators and beams, ISSN 2469-9888, Bd. 23 (2020), 10, S. 103101-1-103101-10
Energy-resolved secondary electron spectroscopy has been performed on air-exposed standard Cu samples and modified Cu surfaces that are tested and possibly applied to efficiently suppress electron cloud formation in the high-luminosity upgrade of the Large Hadron Collider at CERN. The Cu samples comprise pristine oxygen-free, carbon-coated and laser-structured surfaces, which were characterized prior to and after electron irradiation and rare-gas ion bombardment. Secondary-electron and reflected-electron yields measured with low charge dose of the samples exhibit a universal dependence on the energy of the primary impinging electrons. State-of-the-art models can successfully be used to describe the spectroscopic data. The supplied spectral dependence of electron emission and integrated electron yield as well as the derived parametrization can serve as a basis for forthcoming simulations of electron cloud formation and multipacting.
https://doi.org/10.1103/PhysRevAccelBeams.23.103101
Subsampling approaches for compressed sensing with ultrasound arrays in non-destructive testing. - In: Sensors, ISSN 1424-8220, Bd. 20 (2020), 23, 6734, insges. 23 S.
Full Matrix Capture is a multi-channel data acquisition method which enables flexible, high resolution imaging using ultrasound arrays. However, the measurement time and data volume are increased considerably. Both of these costs can be circumvented via compressed sensing, which exploits prior knowledge of the underlying model and its sparsity to reduce the amount of data needed to produce a high resolution image. In order to design compression matrices that are physically realizable without sophisticated hardware constraints, structured subsampling patterns are designed and evaluated in this work. The design is based on the analysis of the Cramér–Rao Bound of a single scatterer in a homogeneous, isotropic medium. A numerical comparison of the point spread functions obtained with different compression matrices and the Fast Iterative Shrinkage/Thresholding Algorithm shows that the best performance is achieved when each transmit event can use a different subset of receiving elements and each receiving element uses a different section of the echo signal spectrum. Such a design has the advantage of outperforming other structured patterns to the extent that suboptimal selection matrices provide a good performance and can be efficiently computed with greedy approaches.
https://doi.org/10.3390/s20236734
Mensch-Maschine-Schnittstelle in der digitalen Fabrikhalle 2030 : DKE : Teil 5: "Umgang mit Unterschieden zwischen Kulturen, Milieus, Generationen, Bildungsniveaus, Überforderungsschwellen". - In: DIN-Mitteilungen + Elektronorm, ISSN 0722-2912, Bd. 99 (2020), 8, S. 35-38
Mensch-Maschine-Schnittstelle in der digitalen Fabrikhalle 2030 : DKE : Teil 2: "Die Kooperation mehrerer Nutzer in unterschiedlichen Rollen beim Maschineneinsatz" (Zukunftszenario 1). - In: DIN-Mitteilungen + Elektronorm, ISSN 0722-2912, Bd. 99 (2020), 2, S. 10-14
Mensch-Maschine-Schnittstelle in der digitalen Fabrikhalle 2030 : DKE : Teil 7: Szenario 7 "Die Maschine als Lernort" und Szenario 8 "Smartwatches im Fertigungsumfeld". - In: DIN-Mitteilungen + Elektronorm, ISSN 0722-2912, Bd. 99 (2020), 12, S. 20-24