The toxic nature of polycyclic aromatic hydrocarbons (PAHs), in particular benzo[a]pyrene (B[a]P), neccessitates the monitoring of PAH contamination levels in food and the environment. Here we introduce an indirect immunoassay format using electro-switchable biosurfaces (ESB) for the detection of B[a]P in water. The association of anti-B[a]P antibodies to microelectrodes is analyzed in real-time by measuring changes in the oscillation dynamics of DNA nanolever probes, which are driven to switch their orientations by high-frequency electrical actuation. From the association kinetics, the active concentration of anti-B[a]P, and hence the B[a]P contamination of the sample, can be determined with picomolar sensitivity. The detection limit of the assay improves with measurement time because increasingly accurate analyses of the binding kinetics become possible. It is demonstrated that an exceedance of the permissible 10 ng/L (40 pM) limit for B[a]P is detectable in an unprecedented short assay time (<1 h), using a simple three-step workflow involving minimal sample preparation. The reproducibility was satisfying with standard deviations below 5%. Further, the utility of the assay for practical applications is exemplified by analyzing a river water sample.

Industrial robots are usually not suitable for high-precision applications due to their limited absolute accuracy. This issue can be solved by calibrating the robot using an adequate model of its kinematic chain and physical behaviour. However, this presupposes a deep understanding of the effects that influence the absolute accuracy and repeatability of the robot. This paper outlines a set of experiments to gain this knowledge by analysing the effects that limit the precision and furthermore presents a way for the proper visualisation of the consequent errors. The investigation includes a range of robots with different characteristics to gather valid and preferably universal information for off-the-shelf industrial robots.

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In the past 20 years, a vast amount of research has shown that Augmented and Mixed Reality applications can support physical exercises in medical rehabilitation. In this paper, we contribute a taxonomy, providing an overview of the current state of research in this area. It is based on a comprehensive literature review conducted on the five databases Web of Science, ScienceDirect, PubMed, IEEE Xplore, and ACM up to July 2021. Out of 776 identified references, a final selection was made of 91 papers discussing the usage of visual stimuli delivered by AR/MR or similar technology to enhance the performance of physical exercises in medical rehabilitation. The taxonomy bridges the gap between a medical perspective (Patient Type, Medical Purpose) and the Interaction Design, focusing on Output Technologies and Visual Guidance. Most approaches aim to improve autonomy in the absence of a therapist and increase motivation to improve adherence. Technology is still focused on screen-based approaches, while the deeper analysis of Visual Guidance revealed 13 distinct, reoccurring abstract types of elements. Based on the analysis, implications and research opportunities are presented to guide future work.

To determine whether the "finish" of steel prior to electroplating affects the protective value of the plated coatings, strips of cold-rolled steel were polished with wheels to which abrasives of different grain size were glued . The resultant finishes were measured with a Profilometer and were expressed as root mean square, in microinches (millionths of an inch) of the departure of the contours from a plane surface. The finishes varied from a "s uperfinish," with root mean square of less than 1 microinch, to 65 microinches, produced with a 90-grain abrasive. The weight (and average thickness) of steel removed by polishing was measured.The polished specimens were plated with copper, nickel, and chromium of controlled thickness, and were exposed to the atmosphere at N ew York, N. Y.; Sandy Hook, N . J.; and Washington, D . C. The extent of rusting observed at periodic inspections was expressed on a numerical scale, and the average results over a period such as 1 year ",ere expressed as "Percentage scores."Comparison of these scores showed that wide differences in the surface finish of the steel had no significant effects on the protective value of the plated coatings. It is possible that use of hot-rolled steel, which is more likely to contain foreign inclusions, would have yielded differences as a result of polishing.Results with accelerated tests, such as the salt spray, hot water, ferroxyl, and condensation tests, were not as reproducible and consistent as the atmospheric tests.