Safe Transport of Acrylic Acid in Railroad Tank Cars. Part 1: Determination of the Self‐Accelerating Decomposition Temperature

Experiments according to a test specified in the UN Recommendations on the Transport of Dangerous Goods, Manual of Tests and Criteria, and numerical simulations by means of a finite element method are employed to determine the self‐accelerating decomposition temperature of acrylic acid in a railroad tank car. The results demonstrate that the transport of acrylic acid in big tank cars is safe as long as some basic conditions are taken into account.     

A Model to Characterize and Predict Fugitive Emissions from Flange Joints

The new model describing the gaseous transport through graphite gaskets is based on the assumption of a flow in the transition regime through nano‐scale capillaries, using the Maxwellian wall‐slip boundary condition for rarefied gases. Together with an earlier published model describing the liquid transport in graphite gaskets, it enables the characterization of fugitive emissions of volatile organic compounds from fluid‐charged flange joints in chemical and petrochemical plants as a function of medium properties, pipe pressure, and gasket stress. Additionally, combination of the models allows predicting the emission rates of gases by experiments with liquids as the emitting fluid. Finally, recommendations are made to improve the gaskets with respect to their sealing performance towards gases.     

Maintenance procedures and definition of limit states for exterior wood coatings

Maintenance procedures of different wood coating systems were studied in field exposure trials with coated balcony constructions. Maintenance coatings were applied on one half of each of the balcony parts after 18 months and assessed after 24 months of total exposure time. It was found that the opaque white coating systems were the most durable ones reaching long intervals of required maintenance. For systems with lower durability on the maintained surfaces further degradation of the coatings was prevented. Different characteristics were observed for film forming and non film forming semi-transparent varnishes. Definitions of a series of limit states for coating systems on wood were suggested including esthetical limits and three levels of durability limits. Film forming coatings can reach two durability limits, i.e. the maintenance interval and the renovation interval. For non film forming coatings there is only one limit state of coating durability where maintenance is needed. The third durability limit is related to the coated substrate, i.e. the wood component, by the onset of decay in wood.     

Automation of Solubility Measurements on a Robotic Platform

Experimental investigation in the laboratory can be accelerated and supported by miniaturized automation techniques. In the design of unit operations, e.g., for crystallization and precipitation processes or for chromatographic separations where no solids should appear during the run, reliable solubility data are mandatory. The development and validation of a robotic routine for completely automated solubility measurements are introduced. The triple‐determination of automated solubility measurements of the model systems succinic acid and adipic acid/water have a relative standard deviation below 0.99 % and are comparable to literature and manual experiments. Data are generated with high precision and accuracy, and the experimental effort and the hands‐on time are reduced significantly to a few minutes necessary to prepare the platform since all subsequent pipetting and control steps are automated.     

Implementation and evaluation of wearable reaction time tests

Conducting cognitive assessment tests throughout normal daily life offers new opportunities to early detect changes in cognitive efficiency. Such tests would allow identification of early symptoms of cognitive impairment, monitor the progress of disease processes related to cognitive efficiency and reduce the risk of cognitive overload. Reaction time tests are known as simple and sensitive tests for detecting variation in cognitive efficiency. A drawback of existing reaction time tests is that they require the full attention of a test person, which prohibits the measurement of cognitive efficiency during daily routine tasks. In this contribution we present the design, implementation and empirical evaluation of two wearable reaction time tests that can be operated throughout everyday life. We designed and implemented wearable watch-like devices, which combine the generation of haptic stimuli and the recognition of hand gestures as the subject’s response. For the evaluation of the wearable interface, we conducted a user study with 20 subjects to investigate to what extent we can measure changes in length and variability of user’s reaction time with the wearable interfaces in comparison to well accepted, traditional desktop-based tests. Based on the achieved statistical results, we conclude that the presented wearable reaction time tests are suitable to measure factors that influence length and variability of reaction times.     

Weathering indicator for artificial and natural weathering of wood coatings

The aim of the present study was to find and develop a sensor to evaluate the weathering rates of wood coatings during natural and artificial weathering using a material of known and controlled rate of decomposition. This was achieved by the use of a coating based on poly (vinyl acetate) copolymer binder in combination with Fe²⁺ as redox catalyst. It was possible to model the decomposition rates by dry film thickness, Fe²⁺ concentration and addition of pigments. One application of this sensor for wood coatings is to indicate the need of maintenance.     

Continuous activity recognition in a maintenance scenario: combining motion sensors and ultrasonic hands tracking

We describe the design and evaluation of pattern analysis methods for the recognition of maintenance-related activities. The presented work focuses on the spotting of subtle hand actions in a continuous stream of data based on a combination of body-mounted motion sensors and ultrasonic positioning. The spotting and recognition approach is based on three core ideas: (1) the use of location information to compensate for the ambiguity of hand motions, (2) the use of motion data to compensate for the slow sampling rate and unreliable signal of the low cost ultrasonic positioning system, and (3) an incremental, multistage spotting methodology. The proposed methods are evaluated in an elaborate bicycle repair experiment containing nearly 10 h of data from six subjects. The evaluation compares different strategies and system variants and shows that precision and recall rates around 90% can be achieved.