Dynamics of Fe(II), sulphur and phosphate in pilot-scale constructed wetlands treating a sulphate-rich chlorinated hydrocarbon contaminated groundwater

Long-term investigations were carried out in two pilot-scale horizontal subsurface flow constructed wetlands (planted and unplanted) with an iron-rich soil matrix for treating sulphate-rich groundwater which was contaminated with low concentrations of chlorinated hydrocarbons. The temporal and spatial dynamics of pore-water sulphide, Fe(II) and phosphate concentrations in the wetland beds were characterized and the seasonal effects on sulphide production and nitrification inhibition were evaluated. The results demonstrated that the pore-water sulphide concentrations gradually increased from less than 0.2 mg/L in 2005 to annual average concentrations of 15 mg/L in 2010, while the pore-water Fe(II) concentrations decreased from 35.4 mg/L to 0.3 mg/L. From 2005 to 2010, the phosphate removal efficiency declined from 91% to 10% under a relatively constant inflow concentration of 5 mg/L. The pronounced effect of plants was accompanied by a higher sulphate reduction and ammonium oxidation in the planted bed, as compared to the unplanted control. A high tolerance of plants towards sulphide toxicity was observed, which might be due to the detoxification of sulphide by oxygen released by the roots. However, during the period of 2009-2010, the nitrification was negatively impacted by the sulphide production as the reduction in the removal of ammonium from 75% to 42% (with inflow concentration of 55 mg/L) correlated with the increasing mean annual sulphide concentrations. The effect of the detoxification of sulphide and the immobilization of phosphate by the application of the iron-rich soil matrix in the initial years was proven; however, the life-span of this effect should not only be taken into consideration in further design but also in scientific studies.     

Rheinbrücke Breisach – Umbau und Instandsetzung einer 45 Jahre alten Stahlkonstruktion

The Rhine Bridge at Breisach – Alteration and maintenance work at a 45‐years‐old steel structure across the river Rhine. The Breisach Rhine Bridge between Breisach in Baden‐Württemberg, Germany, and Neuf‐Brisach in Alsace, France, is next to the Europe Bridge Kehl–Strasbourg the most important road connection between the two countries. The three‐pillar road bridge was built in 1962 using the foundation of an old railway bridge. The box girder of the bridge is welded as well as riveted and bolted. Both the design of the curb with its underseepage – a feature that was often used at that time but is now out of favour – and damages at the drain pipes in the girder box led to significant corrosion damage. In the future a bicycle lane will run over the bridge. For this an enlargement of the southern footpath is required. Bridge repair and maintenance work began in the spring of 2008. In this paper not only the details of the projects will be considered, but also the solutions to the problems discovered during repair work. An additional special feature of the bridge is the fact that two road construction agencies, one French, one German, are in charge of maintenance.     

Faces versus patterns: Exploring aesthetic reactions using facial EMG.

We used facial EMG to examine reactions to the attractiveness of natural (faces) and artificial (abstract patterns) stimuli under long and short presentation durations. Attractive stimuli produced strong activations of the M. zygomaticus major muscle, indicating positive affective reactions; and unattractive stimuli produced strong activations of the M. corrugator supercili muscle, indicating negative affective reactions. Fluency effects, indicated by stronger activations of the M. zygomaticus major under the longer presentation duration were, however, only found for the abstract patterns. Moreover, the abstract patterns also were associated with more consistent activations over time than the faces, suggesting differences in the processes underlying the evaluation of faces and patterns. We discuss these results in terms of differences in appraisal processes between the two classes of stimuli—the greater biological, social, and sociosexual significance of faces trigger more complex appraisals than the abstract patterns. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Thermophysical Properties of Platinum-Copper Alloys

Platinum and copper along with their alloys have been used in a broad range of applications including jewelry, coinage, electrical and electronic devices, and many others. Their thermophysical properties play an important role in casting processes and are required as input data for casting simulation. The focus of this work was to investigate these properties by different methods. Platinum, copper, and four platinum-copper alloys, namely, Pt96Cu04, Pt68Cu32, Pt50Cu50, and Pt25Cu75, were investigated within this work. The melting range and thermal expansion were measured at fem by differential scanning calorimetry and dilatometry, respectively. At TU Graz, wire-shaped samples were investigated by an ohmic pulse heating technique. This technique delivers thermophysical properties of electrically conducting materials far into the liquid phase. These measurements allow the calculation of specific heat capacity and the temperature dependencies of electrical resistivity, enthalpy, and density of these alloys in the solid and liquid phases. Thermal conductivity and thermal diffusivity as a function of temperature are estimated from resistivity data using the Wiedemann?CFranz law at the end of the solid phase and at the beginning of the liquid phase. The results are compared with the available literature values.     

Thermophysical Properties of Liquid Aluminum

Ohmic pulse-heating with sub-microsecond time resolution is used to obtain thermophysical properties for aluminum in the liquid phase. Measurement of current through the sample, voltage drop across the sample, surface radiation, and volume expansion allow the calculation of specific heat capacity and the temperature dependencies of electrical resistivity, enthalpy, and density of the sample at melting and in the liquid phase. Thermal conductivity and thermal diffusivity as a function of temperature are estimated from resistivity data using the Wiedemann–Franz law. Data for liquid aluminum obtained by pulse-heating are quite rare because of the low melting temperature of aluminum with 933.47 K (660.32 °C), as the fast operating pyrometers used for the pulse-heating technique with rise times of about 100 ns generally might not be able to resolve the melting plateau of aluminum because they are not sensitive enough for such low temperature ranges. To overcome this obstacle, we constructed a new, fast pyrometer sensitive in this temperature region. Electromagnetic levitation, as the second experimental approach used, delivers data for surface tension (this quantity is not available by means of the pulse-heating technique) and for density of aluminum as a function of temperature. Data obtained will be extensively compared to existing literature data.

     

Search asymmetries with real faces: Testing the anger-superiority effect.

The anger-superiority hypothesis states that angry faces are detected more efficiently than friendly faces. Previously research used schematized stimuli, which minimizes perceptual confounds, but violates ecological validity. The authors argue that a confounding of appearance and meaning is unavoidable and even unproblematic if real faces are presented. Four experiments tested carefully controlled photos in a search-asymmetry design. Experiments 1 and 2 revealed more efficient detection of an angry face among happy faces than vice versa. Experiment 3 indicated that the advantage was due to the mouth, but not to the eyes, and Experiment 4, using upright and inverted thatcherized faces, suggests a perceptual basis. The results are in line with a sensory-bias hypothesis that facial expressions evolved to exploit extant capabilities of the visual system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decreased emitter sheet resistivity loss in high-eficiency silicon solar cells

State-of-the-art two-dimensional (2D) numerical semiconductor device simulation tools are applied to bifacially contacted silicon solar cells of practical dimensions in order to investigate the 2D effects arising from ohmic voltage drops in cell emitters due to finite front metal grid line spacings. the 2D simulations show that for typical front finger spacings of high-efficiency silicon solar cells the minority carrier flow in the base deviates strongly from the purely linear flow assumed by one-dimensional (1D) theory. Compared to conventional 1D theory, this 2D effect results in reduced emitter sheet resistivity losses, an increased optimum front finger spacing and a reduced impact of finger spacing on cell efficiency. the 2D effects are of particular importance for concentrator solar cells. The 2D simulations presented in this work considerably improve the general understanding of internal device physics of high-efficiency silicon solar cells and reveal the limits of 1D models for the simulation of these devices.     

Pattern recognition methods for advanced stochastic protein sequence analysis using HMMs

Currently, Profile Hidden Markov Models (Profile HMMs) are the methodology of choice for probabilistic protein family modeling. Unfortunately, despite substantial progress the general problem of remote homology analysis is still far from being solved. In this article we propose new approaches for robust protein family modeling by consequently exploiting general pattern recognition techniques. A new feature based representation of amino acid sequences serves as the basis for semi-continuous protein family HMMs. Due to this paradigm shift in processing biological sequences the complexity of family models can be reduced substantially resulting in less parameters which need to be trained. This is especially favorable when only little training data is available as in most current tasks of molecular biology research. In various experiments we prove the superior performance of advanced stochastic protein family modeling for remote homology analysis which is especially relevant for e.g. drug discovery applications.