Towards optimal control of fuel cell hybrid electric vehicles

Global warming, the decline of natural resources as well as the strengthening of emission regulations have led to a research focus in new drive technologies. Within the group of alternative propulsion systems, fuel cell hybrid electric vehicle (FHEV) are considered especially promising. Since system efficiency as well as the operation characteristics are determined by the chosen energy management system (EMS) scheme, an optimal approach is a key aspect to guarantee optimal system operation in terms of power and energy efficiency, as well as component lifetime and costs. Existing research efforts mostly focus on the optimisation of the hydrogen consumption, while neglecting component degradation as additional important part of total system and operation cost. Furthermore, almost no published work considers the thermal management of a FHEV. Therefore, the presented work propose a novel model predictive control based energy management approach with a special focus on preventing fuel cell (FC) and battery (BAT) degradation and the vehicle’s thermal management. In order to minimise component ageing and degradation, the objective function which is used in the developed method, includes cost which account for both decreasing BAT state of health as well as FC operation conditions which accelerate the degradation of the FC. To be able to test the developed EMS, a model and a hardware based test environment were developed. Since there are no thermal management systems for FHEV presented in literature, a new concept with a hierarchical control scheme was designed. Because the newly developed energy management shall be tested based on real world data, a method to generate test cases representing typical driving scenarios based on real world driving data was developed and implemented. Finally, the hardware system was used to validate the simulation model and vice versa, the model based approach was validated on real hardware

Quantitative Stain-free and Continuous Multimodal Monitoring of Wound Healing in vitro with Digital Holographic Microscopy

Impaired epithelial wound healing has significant pathophysiological implications in several conditions including gastrointestinal ulcers, anastomotic leakage and venous or diabetic skin ulcers. Promising drug candidates for accelerating wound closure are commonly evaluated in in vitro wound assays. However, staining procedures and discontinuous monitoring are major drawbacks hampering accurate assessment of wound assays. We therefore investigated digital holographic microscopy (DHM) to appropriately monitor wound healing in vitro and secondly, to provide multimodal quantitative information on morphological and functional cell alterations as well as on motility changes upon cytokine stimulation. Wound closure as reflected by proliferation and migration of Caco-2 cells in wound healing assays was studied and assessed in time-lapse series for 40 h in the presence of stimulating epidermal growth factor (EGF) and inhibiting mitomycin c. Therefore, digital holograms were recorded continuously every thirty minutes. Morphological changes including cell thickness, dry mass and tissue density were analyzed by data from quantitative digital holographic phase microscopy. Stimulation of Caco-2 cells with EGF or mitomycin c resulted in significant morphological changes during wound healing compared to control cells. In conclusion, DHM allows accurate, stain-free and continuous multimodal quantitative monitoring of wound healing in vitro and could be a promising new technique for assessment of wound healing

Handlungsfelder der gestaltungsorientierten Wirtschaftsinformatik im Kontext der Digitalen Fabrik

In Wissenschaft und Praxis beschäftigen sich unterschiedliche Disziplinen mit Methoden, Konzepten und Werkzeugen zur Verbesserung der Leistungsfähigkeit industrieller Unternehmen. Hierfür hat sich der Begriff der Digitalen Fabrik interdisziplinär etabliert, wobei festzustellen ist, dass ein einheitliches und disziplinübergreifendes Verständnis bisher nicht existiert. In diesem Beitrag werden daher die verschiedenen Definitionen für die Digitale Fabrik aufgezeigt sowie deren Bestandteile strukturiert dargestellt. Darauf aufbauend erfolgt die forschungstheoretisch begründete Zuordnung derjenigen Teilgebiete, die zu den Handlungsfeldern der gestaltungsorientierten Wirtschaftsinformatik gehören. Basierend auf der Erkenntnis, dass die Digitale Fabrik bisher ingenieurswissenschaftlich getrieben ist, werden für die identifizierten Felder Handlungsempfehlungen für die Wirtschaftsinformatik abgeleitet

Impact of a Glycolic Acid-Containing pH 4 Water-in-Oil Emulsion on Skin pH

The skin pH is crucial for physiological skin functions. A decline in stratum corneum acidity, as observed in aged or diseased skin, may negatively affect physiological skin functions. Therefore, glycolic acid-containing water-in-oil (W/O) emulsions adjusted to pH 4 were investigated regarding their effect on normal or increased skin pH. A pH 4 W/O emulsion was applied on three areas with pathologically increased skin surface pH in diabetics (n = 10). Further, a 28-day half-side trial (n = 30) was performed to test the long-term efficacy and safety of a pH 4 W/O emulsion (n = 30). In summary, the application of a pH 4 W/O emulsion reduced the skin pH in healthy, elderly and diabetic subjects, which may improve epidermal barrier functions

Optical constants of silicon carbide for astrophysical applications. II. Extending optical functions from IR to UV using single-crystal absorption spectra

Laboratory measurements of unpolarized and polarized absorption spectra of various samples and crystal stuctures of silicon carbide (SiC) are presented from 1200--35,000 cm$^{-1}$ ($\lambda \sim$ 8--0.28 $\mu$m) and used to improve the accuracy of optical functions ($n$ and $k$) from the infrared (IR) to the ultraviolet (UV). Comparison with previous $\lambda \sim$ 6--20 $\mu$m thin-film spectra constrains the thickness of the films and verifies that recent IR reflectivity data provide correct values for $k$ in the IR region. We extract $n$ and $k$ needed for radiative transfer models using a new ``difference method'', which utilizes transmission spectra measured from two SiC single-crystals with different thicknesses. This method is ideal for near-IR to visible regions where absorbance and reflectance are low and can be applied to any material. Comparing our results with previous UV measurements of SiC, we distinguish between chemical and structural effects at high frequency. We find that for all spectral regions, 3C ($\beta$-SiC) and the $\vec{E}\bot \vec{c}$ polarization of 6H (a type of $\alpha$-SiC) have almost identical optical functions that can be substituted for each other in modeling astronomical environments. Optical functions for $\vec{E} \| \vec{c}$ of 6H SiC have peaks shifted to lower frequency, permitting identification of this structure below $\lambda \sim4\mu$m. The onset of strong UV absorption for pure SiC occurs near 0.2 $\mu$m, but the presence of impurities redshifts the rise to 0.33 $\mu$m. Optical functions are similarly impacted. Such large differences in spectral characteristics due to structural and chemical effects should be observable and provide a means to distinguish chemical variation of SiC dust in space.Comment: 46 pages inc. 8 figures and 2 full tables. Also 6 electronic-only data files. Accepted by Ap

Finding Optimal Timetables for Edinburgh Bus Routes

AbstractWe present a novel application of stochastic simulation and model-checking methods to determining whether bus services are fulfilling their service-level agreement to provide on-time departures of buses from stops sufficiently often. We use open data on predicted bus arrival times to parameterise a stochastic model of a particular bus route from Edinburgh city centre out to suburban and rural areas to the south of the city. We validate and then analyse our stochastic model using both simulation and model-checking methods. Finally, we complete an optimisation study on the model and discover a better timetable for the service which would expose the bus service operator to less financial risk of penalties being applied by the regulatory authorities which define standards for bus service, punctuality and reliability

The INF Treaty of 1987

Der von Ronald Reagan und Michail Gorbatschow am 8. Dezember 1987 unterzeichnete »Intermediate-Range Nuclear Forces Treaty«, kurz INF-Vertrag, stellte einen Meilenstein der nuklearen Abrüstungsverhandlungen zwischen den Vereinigten Staaten von Amerika und der Sowjetunion dar. Im Jahr 2019 wurde er von Russland und den USA gekündigt. Der englischsprachige Band untersucht die Vorgeschichte des Abkommens, dessen Implementierung und Folgen sowohl in den beiden Supermächten als auch in den mit ihnen verbündeten Staaten. Er ist damit die erste umfassende Darstellung eines der wichtigsten Abrüstungsabkommen der jüngsten Zeit

Разработка нейросетевого подхода сегментации и распознавания номерных знаков автомобилей на изображениях реальных сцен

Объектом исследования являются методы искусственного интеллекта, используемые в алгоритмах сегментации и распознавания автомобильных номерных знаков. Целью работы является разработка и реализация алгоритма детектирования и распознавания автомобильных номерных знаков на изображениях реальных сцен с применением аппарата искусственных нейронных сетейThe object of research is the artificial intelligence methods used in the segmentation and recognition of automobile license plates. The aim of the work is to develop and implement an algorithm for detecting and recognizing car license plates on images of real scenes using the apparatus of artificial neural network

Properties of dust in the Galactic center region probed by AKARI far-infrared spectral mapping - detection of a dust feature

We investigate the properties of interstellar dust in the Galactic center region toward the Arches and Quintuplet clusters. With the Fourier Transform Spectrometer of the AKARI/Far-Infrared Surveyor, we performed the far-infrared (60 - 140 cm^-1) spectral mapping of an area of about 10' x 10' which includes the two clusters to obtain a low-resolution (R = 1.2 cm^-1) spectrum at every spatial bin of 30" x 30". We derive the spatial variations of dust continuum emission at different wavenumbers, which are compared with those of the [O III] 88 micron (113 cm^-1) emission and the OH 119 micron (84 cm^-1) absorption. The spectral fitting shows that two dust modified blackbody components with temperatures of ~20 K and ~50 K can reproduce most of the continuum spectra. For some spectra, however, we find that there exists a significant excess on top of a modified blackbody continuum around 80 - 90 cm^-1 (110 - 130 microns). The warmer dust component is spatially correlated well with the [O III] emission and hence likely to be associated with the highly-ionized gas locally heated by intense radiation from the two clusters. The excess emission probably represents a dust feature, which is found to be spatially correlated with the OH absorption and a CO cloud. We find that a dust model including micron-sized graphite grains can reproduce the observed spectrum with the dust feature fairly well.Comment: 10 pages, 8 figures, accepted for publication in A&

Excitation of H2_2 in photodissociation regions as seen by Spitzer

We present spectroscopic observations obtained with the infrared Spitzer Space Telescope, which provide insight into the H$_2$ physics and gas energetics in photodissociation Regions (PDRs) of low to moderate far-ultraviolet (FUV) fields and densities. We analyze data on six well known Galactic PDRs (L1721, California, N7023E, Horsehead, rho Oph, N2023N), sampling a poorly explored range of excitation conditions ($\chi \sim 5-10^3$), relevant to the bulk of molecular clouds in galaxies. Spitzer observations of H$_2$ rotational lines are complemented with H$_2$ data, including ro-vibrational line measurements, obtained with ground-based telescopes and ISO, to constrain the relative contributions of ultraviolet pumping and collisions to the H$_2$ excitation. The data analysis is supported by model calculations with the Meudon PDR code. The observed column densities of rotationally excited H$_2$ are observed to be much higher than PDR model predictions. In the lowest excitation PDRs, the discrepancy between the model and the data is about one order of magnitude for rotational levels $J \ge$3. We discuss whether an enhancement in the H$_2$ formation rate or a local increase in photoelectric heating, as proposed for brighter PDRs in former ISO studies, may improve the data-model comparison. We find that an enhancement in the H$_2$ formation rates reduces the discrepancy, but the models still fall short of the data. This large disagreement suggests that our understanding of the formation and excitation of H$_2$ and/or of PDRs energetics is still incomplete. We discuss several explanations, which could be further tested using the Herschel Space TelescopeComment: A&A in pres