On the 3D distribution and size fractionation of microparticles in a serpentine microchannel. - In: Microfluidics and nanofluidics, ISSN 1613-4990, Bd. 24 (2020), 3, 22, S. 1-10
https://doi.org/10.1007/s10404-020-2326-7
On the theory of deuteron NMR free induction decay of reptating polymer chains: effect of end segment dynamics. - In: The journal of chemical physics, ISSN 1089-7690, Bd. 152 (2020), 18, 184904, insges. 12 S.
https://doi.org/10.1063/5.0005049
Field emission scanning probe lithography with GaN nanowires on active cantilevers. - In: Journal of vacuum science & technology, ISSN 2166-2754, Bd. 38 (2020), 3, S. 032806-1-032806-6
https://doi.org/10.1116/1.5137901
Inductive temperature measurement: a new sensor improvement for industrial applications. - In: Review of scientific instruments, ISSN 1089-7623, Bd. 91 (2020), 4, S. 046101-1-046101-3
https://doi.org/10.1063/1.5078581
A new array concept using spatially distributed subarrays for unambiguous GNSS interference mitigation in automotive applications. - In: Navigation, ISSN 2161-4296, Bd. 67 (2020), 1, S. 23-41
https://doi.org/10.1002/navi.353
Origins of boosted charge storage on heteroatom-doped carbons. - In: Angewandte Chemie, ISSN 1521-3757, Bd. 132 (2020), 20, S. 8002-8007
https://doi.org/10.1002/ange.202000319
Review on recent advances of cathode materials for potassium-ion batteries. - In: Energy & Environmental Materials, ISSN 2575-0356, Bd. 3 (2020), 1, S. 56-66
https://doi.org/10.1002/eem2.12060
On the application of neural networks for temperature field measurements using thermochromic liquid crystals. - In: Experiments in fluids, ISSN 1432-1114, Bd. 61 (2020), 4, 111, S. 1-21
This study presents an investigation regarding the applicability of neural networks for temperature measurements using thermochromic liquid crystals (TLCs) and discusses advantages as well as disadvantages of common calibration approaches. For the characterization of the measurement technique, the dependency of the color of the TLCs on the temperature as well as on the observation angle and, therefore, on the position within the field of view of a color camera is analyzed in detail. In order to consider the influence of the position within the field of view on the color, neural networks are applied for the calibration of the temperature measurements. In particular, the focus of this study is on analysis of the error of temperature measurement for different network configurations as well as training methods, yielding a mean absolute deviation and a mean standard deviation in the range of 0.1 K for instantaneous measurements. On the basis of a comparison of this standard deviation to that of two further calibration approaches, it is shown that neural networks are suited for temperature measurements via the color of TLCs. Finally, the applicability of this measurement technique is illustrated at an exemplary temperature measurement in a horizontal plane of a Rayleigh-Bénard cell with large aspect ratio, which clearly shows the emergence of convective flow patterns by means of the temperature field.
https://doi.org/10.1007/s00348-020-2943-7
Composite spiral multi-value zone plates. - In: Applied optics, ISSN 2155-3165, Bd. 59 (2020), 15, S. 4618-4623
We present composite spiral multi-value phase zone plates that are achieved by sectioning a spiral multi-value phase zone plate into several radial regions. Each region is composed of specially structured Fresnel zones with optimized phase values and an embedded basic topological charge. In numerical studies, it is shown that the proposed element is capable of producing equal intensity arrays of petal-like modes as well as dark optical ring lattice structures along the optical axis in multiple focal planes of the diffractive element. Additionally, it is demonstrated that the generated petal-like modes can be rotated in a controllable manner by implementing an angular frequency shift between the two composited spiral multi-value phase zone plates. We also illustrate that the rotation angle is independent of the diffraction order. Experimental results are included to verify the theoretical outcomes, where the phase pattern of the composite spiral multi-value zone plate is encoded onto a spatial light modulator.
https://doi.org/10.1364/AO.392746
Evaluation of quadratic phase hologram calculation algorithms in the Fourier regime. - In: Applied optics, ISSN 2155-3165, Bd. 59 (2020), 6, S. 1501-1506
The display of phase-only holograms with a spatial light modulator (SLM) has many applications due to its potential for dynamic three-dimensional projection of arbitrary patterns. We describe an innovative modification of the quadratic phase method for hologram calculation that uses error diffusion for initialization of an iterative phase retrieval algorithm. We compare the performance of our algorithm to other variations of hologram calculation approaches that use the quadratic phase method in the Fourier regime. Parameter variation is conducted for finding the differences and limits of the methods. Experiments with an SLM show the validity of the simulations.
https://doi.org/10.1364/AO.381547