Hochschule Bonn-Rhein-Sieg
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ZAT: Guidelines for Research Data in Research and Development Processes of Pro-adaptive Cognitive Assistive Technologies (Pro-CAT)
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Cover Feature: Amphiphilic Fluoro‐Functionalized Cellulosic Materials: Synthesis, Characterization, and Organic Dye Adsorption Properties (Eur. J. Org. Chem. 20/2025)
No full textRichtlinie des Präsidiums der Hochschule Bonn-Rhein-Sieg für die Vergabe von Leistungsbezügen für Professor:innen
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4-Methyl-3-penten-2-on – Bestimmung von 4-Methyl-3-penten-2-on (Mesityloxid) in der Luft am Arbeitsplatz mittels Hochleistungsflüssigkeitschromatographie (HPLC-DAD)
No full textThe working group “Air Analyses” of the German Senate Commission for the Investigation of Health Hazards of Chemical Compounds in the Work Area (MAK Commission) developed and verified the presented analytical method. It is used to determine the levels of 4-methyl-3-penten-2-one [141-79-7] that occur in the workplace air. The method covers concentrations in the range from one tenth up to twice the current occupational exposure limit value (OELV) of 8.1 mg/m3. The method is also suitable for verifying the short-term exposure limit (STEL; excursion factor 2). Samples are collected by drawing a defined volume of air through a sampling tube filled with silica gel using a flow regulated pump at a volumetric flow rate of 0.5 l/min. Exposure during the shift is measured with a sampling period of 2 hours and the short-term exposure with a period of 15 minutes. The 4-methyl-3-penten-2-one adsorbed to the silica gel is extracted by liquid extraction with methanol and analysed by high-performance liquid chromatography using diode array detection. The quantitative determination is based on multiple-point calibrations with external standards. A relative limit of quantification (LOQ) of 0.06 mg/m3 is obtained for an air sample volume of 60 litres. As the LOQ for a sample volume of 30 litres is 0.03 mg/m3, the STEL can also be measured. The recovery is approx. 100% and the expanded uncertainty is 14% for a sampling period of 2 hours and below 16% for a period of 15 minutes
Universal Metrics to Characterize the Performance of Imaging 3D Measurement Systems With a Focus on Static Indoor Scenes
No full textImaging 3-D measurement systems differ not only in design, power consumption, and resolution but, most notably, in their measurement performance, which is rarely documented in a reproducible or comparable manner. In this work, we introduce a simple, universal methodology for quantitatively characterizing indirect time-of-flight cameras, focusing on point cloud data acquired under reproducible conditions. Our metrics build upon the ISO 5725-1 standard and related research to enable standardized comparisons across different systems, independent of their measurement principles. Beyond trueness, accuracy, and precision, we propose additional metrics to evaluate surface texture quality, addressing visually disruptive systematic measurement errors. We condense these measurements into 14 key metrics for a straightforward camera comparison. In addition, we introduce the energy-density-weighted depth precision index (EPI) as a metric to relate an active measurement system’s performance to the emitted optical power. Finally, we demonstrate the applicability of our methodology by evaluating seven state-of-the-art 3-D systems
Modular architecture of K+ channels: the functional plasticity of the pore module
No full textMiniature K+ channel proteins from viruses (Kcv) are structurally and functionally equivalent to the pore module of all K+ channels. Here, we summarize data in support of the hypothesis that pores of primitive K+ channels served as building blocks for evolving the modern complex mammalian ion channels. Experimental data show that mutations in Kcv channels can generate gating phenomena like slow-activating inward or outward rectification, which are typical of complex mammalian channels. Hence, the basic mechanism for rectification is an inherent property of the pore module, which was further tuned and/or amplified during evolution by the addition of sensory protein domains. This evolutionary trend can be experimentally mimicked by coupling small pore units with a voltage-sensing domain or a glutamate-binding domain to acquire voltage and ligand-sensitive gating. The same modularity principle can be exploited in the design of synthetic channels in which the Kcv pore is coupled to orthogonal sensor domains. These synthetic channels exhibit new gating properties like a sensitivity to light or Ca2+, which originate from their attached sensor domains