Social and collaborative aspects of interaction with a service robot

To an increasing extent, robots are being designed to become a part of the lives of ordinary people. This calls for new models of the interaction between humans and robots, taking advantage of human social and communicative skills. Furthermore, human–robot relationships must be understood in the context of use of robots, and based on empirical studies of humans and robots in real settings. This paper discusses social aspects of interaction with a service robot, departing from our experiences of designing a fetch-and-carry robot for motion-impaired users in an office environment. We present the motivations behind the design of the Cero robot, especially its communication paradigm. Finally, we discuss experiences from a recent usage study, and research issues emerging from this work. A conclusion is that addressing only the primary user in service robotics is unsatisfactory, and that the focus should be on the setting, activities and social interactions of the group of people where the robot is to be used.     

Reactions of Secondary Phases with Carbon in Magnesia‐Carbon Bricks

Despite the excellent thermochemical properties of magnesia carbon bricks, these exhibit one weak characteristic during their use: their carbothermally induced wear. Carbon has a high affinity to oxygen, which leads to a reaction between magnesia and carbon, forming gaseous products at very low oxygen partial pressures in the surrounding atmosphere. When magnesia carbon material is furthermore applied at negative pressures, the precited carbothermic reduction processes effect an internal decomposition or even degradation of the bricks. Mostly, high‐purity magnesia varieties (MgO ≥ 96 wt%) are used for the production of magnesia carbon bricks because the low‐melting calcium silicate secondary phases in magnesia impair the high‐temperature resistance of these bricks. The fundamental question if and to which extent secondary phases react with carbon and which impact they have on the carbothermally induced wear of bricks has been unsolved so far. The following paper presents which influence the mineral secondary phases, monticellite, merwinite, and belite that are most commonly occurring in magnesia, have on the carbothermally induced wear. The respective studies were conducted by means of thermogravimetric and microstructural analyses. The results of these studies show that monticellite in the MgO–C microstructure brings about an increase in weight loss on account of carbothermic reduction processes. On the contrary, belite and merwinite in the MgO–C structure do not exhibit any negative impact on the thermal stability of the microstructure.     

Jakobs-Kreuzkraut (<Emphasis Type="Italic">Senecio jacobaea</Emphasis>): eine Ursache für Pyrrolizidin-Alkaloide im Sommerhonig?

Pyrrolizidine alkaloids (PAs) are secondary plant compounds, which may be carried into honey by honey bees (Apis mellifera) and thus enter the human food chain. Depending on the quantity consumed, PAs are considered harmful to human health. At present, however, there is no statutory limit for PAs in foodstuffs. Because of several hints that larger occurrences of PA-containing tansy ragwort (Senecio jacobaea) may be responsible for PAs in summer honeys, honey samples from regions with and without tansy ragwort from all across Schleswig-Holstein were tested for their PA content (28 individual PAs) by LC-MS/MS analysis in 2014. By including honey samples from surroundings of flower plots established on arable land, it was tested if the carry-over of PAs into honey can be reduced by “distraction feed”. Samples from regions with tansy ragwort showed significantly higher PA contents than those from regions without tansy ragwort. Flower plots had no significant influence on the PA content. PAs were detected in 53.5 % of the 86 honey samples investigated. The mean PA value of PA-positive honeys was much higher than the median value since the sample comprised only few high and many low values. 28.6 % of the detected PAs were not from Senecio species, but from the Borage family (Boraginaceae) or Hemp Agrimony (Eupatorium cannabinum). In 2.3–15.1 % of the samples the limit value recommended by the BfR (Analytik und Toxizität von Pyrrolizidinalkaloiden sowie eine Einschätzung des gesundheitlichen Risikos durch deren Vorkommen in Honig. Stellungnahme Nr. 038/2011 des BfR vom 11. August 2011, ergänzt am 21. Januar 2013. Bundesinstitut für Risikobewertung [Hrsg.], Berlin: 37 S, 2013a) for different eating habits was exceeded. Because of the potential risk to human health, beekeepers and users of land with larger occurrences of tansy ragwort should take joint measures to keep the PA load in summer honeys as low as possible.     

Aryl Polyenes,a Highly Abundant Class of Bacterial Natural Products,Are Functionally Related to Antioxidative Carotenoids

Bacterial pigments of the aryl polyene type are structurally similar to the well‐known carotenoids with respect to their polyene systems. Their biosynthetic gene cluster is widespread in taxonomically distant bacteria, and four classes of such pigments have been found. Here we report the structure elucidation of the aryl polyene/dialkylresorcinol hybrid pigments of Variovorax paradoxus B4 by HPLC‐UV‐MS, MALDI‐MS and NMR. Furthermore, we show for the first time that this pigment class protects the bacterium from reactive oxygen species, similarly to what is known for carotenoids. An analysis of the distribution of biosynthetic genes for aryl polyenes and carotenoids in bacterial genomes is presented; it shows a complementary distribution of these protective pigments in bacteria.     

In Situ Electrochemical Electron Microscopy Study of Oxygen Evolution Activity of Doped Manganite Perovskites

Fundamental studies of catalysts based on manganese oxide compounds are of high interest since they offer the opportunity to study the role of variable valence state in the active state during O₂ evolution from H₂O. This paper presents a study of doping dependent O₂ evolution electrocatalysis of Pr‐doped CaMnO₃ via in situ environmental transmission electron microscopy (ETEM) combined with ex situ cyclic voltammetry studies. ETEM studies of heterogeneous catalysis are a challenge, since the reactions in the H₂O vapor phase cannot directly be observed. It is shown that the oxidation of silane by free oxygen to solid SiO_2‐x can be used to monitor catalytic oxygen evolution. Electron energy loss spectroscopy (EELS) as well as the in situ X‐ray absorption study of near edge structures (XANES) in H₂O vapor reveals that the Mn valence is decreased in the active state. Careful TEM analysis of samples measured by ex situ cyclic voltammetry and an in situ bias‐controlled ETEM study allows us to distinguish between self‐formation during oxygen evolution and corrosion at the Pr_1‐xCa_xMnO₃‐H₂O interface. Including density functional theory (DFT) calculations, trends in O₂ evolution activity and defect chemistry in the active state can be correclated to doping induced changes of the electronic band structure in A‐site doped manganites.     

Influence of ethanol/water mixture on the undrained shear strength of pure clays

The mechanical properties of clays are highly dependent not only on the stress/strain ratio to which the material is subjected but also on the chemistry of the pore fluids which in turn affects the intergranular or the effective stresses. Atterberg limits and vane shear tests were performed with different pore fluids in order to observe how the fine-grained material mechanically responded. The diffuse double layer theory has been used to interpret the data of vane shear tests in order to explain the variation of geotechnical responses with the different clays. Van der Waals forces and double layer forces were obtained and capillary forces calculated. The results show that while for kaolinite and illite the chemistry of the pore fluids has no influence on the water content and hence on the mechanical behaviour of the material, Na-smectite shows a strong correlation between the dielectric constant of the pore fluids and an increase in undrained shear strength. The data obtained extends an understanding of the influence of the dielectric constant (ε) of the pore fluids on the geotechnical properties of fine-grained materials.     

On atmospheric stability in the dynamic wake meandering model

The present study investigates a new approach for capturing the effects of atmospheric stability on wind turbine wake evolution and wake meandering by using the dynamic wake meandering model. The most notable impact of atmospheric stability on the wind is the changes in length and velocity scales of the atmospheric turbulence. The length and velocity scales in the turbulence are largely responsible for the way in which wind turbine wakes meander as they convect downstream. The hypothesis of the present work is that appropriate turbulence scales can be extracted from the oncoming atmospheric turbulence spectra and applied to the dynamic wake meandering model to capture the correct wake meandering behaviour. The ambient turbulence in all stability classes is generated using the Mann turbulence model, where the effects of non‐neutral atmospheric stability are approximated by the selection of input parameters. In order to isolate the effect of atmospheric stability, simulations of neutral and unstable atmospheric boundary layers using large‐eddy simulation are performed at the same streamwise turbulence intensity level. The turbulence intensity is kept constant by calibrating the surface roughness in the computational domain. The changes in the turbulent length scales due to the various atmospheric stability states impact the wake meandering characteristics and thus the power generation by the individual turbines. The proposed method is compared with results from both large‐eddy simulation coupled with an actuator line model and field measurements, where generally good agreement is found with respect to the velocity, turbulence intensity and power predictions. Copyright © 2013 John Wiley & Sons, Ltd.     

Genetics and intelligence: new approaches in production engineering

Parts which inherently store data about their fabrication and find their own way through the production, or, machine components that autonomously monitor themselves and arrange inspections as required may still sound like a vision of the future. Nonetheless, in the Collaborative Research Centre 653 ‘Gentelligent Components in their Lifecycle—Utilisation of Inheritable Component Information in Production Engineering’ they will soon be a reality. Transferring characteristics that are similar to those found in nature to industrial production will lead to a paradigm shift in the development and manufacturing of prospective components. This paper presents the techniques and methods that enable this new approach in production engineering by transferring biological principles from the field of genetics into the manufacturing environment.     

Reactivity of alkaline lignite fly ashes towards CO2 in water

The reaction kinetics between alkaline lignite fly ashes and CO2 (pCO2 = 0.01--0.03 MPa)were studied in a laboratory CO2 flow-through reactor at 25--75 degrees C. The reaction is characterized by three phases that can be separated according to the predominating buffering systems and the rates of CO2 uptake. Phase I (pH > 12, < 30 min) is characterized by the dissolution of lime, the onset of calcite precipitation and a maximum uptake, the rate of which seems to be limited by dissolution of CO2. Phase II (pH < 10.5, 10--60 min) is dominated by the carbonation reaction. CO2 uptake in phase III (pH < 8.3) is controlled by the dissolution of periclase (MgO) leading to the formation of dissolved magnesium-bicarbonate. Phase I could be significantly extended by increasing the solid-liquid ratios and temperature, respectively. At 75 degrees C the rate of calcite precipitation was doubled leading to the neutralization of approximately 0.23 kg CO2 per kg fly ash within 4.5 h, which corresponds to nearly 90% of the total acid neutralizing capacity.