Effects of inland nitrogen transport and attenuation modeling on coastal nitrogen load abatement

Modeling of the spatial distribution of nitrogen transport and attenuation from various inland sources and along different hydrological pathways to coastal waters is needed for relevant decisions on effective allocation of measures for coastal nitrogen load abatement. We identify, classify, and quantify uncertainties associated with main discrepancies between spatial process representations in different catchment-scale nitrogen transport-attenuation models. The results show important model differences, indicating scientific disagreement on the realistic spatial process understanding, representation, and quantification in nitrogen transport-attenuation modeling. By further developing solutions for economic optimization of spatially differentiated nitrogen source abatement in coastal catchments, we find this disagreement to considerably affect the economic efficiency of coastal nitrogen load reduction. It may also lead to stakeholder mistrust and conflict and needs to be recognized and handled in environmental policy.     

Effect of ZrO2 addition on the mechanical properties of porous TiO2 bone scaffolds

This study aimed at the investigation of the effect of zirconium dioxide (ZrO₂) addition on the mechanical properties of titanium dioxide (TiO₂) bone scaffolds. The highly biocompatible TiO₂ has been identified as a promising material for bone scaffolds, whereas the more bioinert ZrO₂ is known for its excellent mechanical properties. Ultra-porous TiO₂ scaffolds (> 89% porosity) were produced using polymer sponge replication with 0–40 wt.% of the TiO₂ raw material substituted with ZrO₂. Microstructure, chemical composition, and pore architectural features of the prepared ceramic foams were characterised and related to their mechanical strength. Addition of 1 wt.% of ZrO₂ led to 16% increase in the mean compressive strength without significant changes in the pore architectural parameters of TiO₂ scaffolds. Further ZrO₂ additions resulted in reduction of compressive strength in comparison to containing no ZrO₂. The appearance of zirconium titanate (ZrTiO₄) phase was found to hinder the densification of the ceramic material during sintering resulting in poor intergranular connections and thus significantly reducing the compressive strength of the highly porous ceramic foam scaffolds.     

Motion of inertial particles in Gaussian fields driven by an infinite-dimensional fractional Brownian motion

We study the motion of an inertial particle in a fractional Gaussian random field. The motion of the particle is described by Newton's second law, where the force is proportional to the difference between the background fluid velocity and the particle velocity. The fluid velocity satisfies a linear stochastic partial differential equation driven by an infinite-dimensional fractional Brownian motion with an arbitrary Hurst parameter H?∈?(0,?1). The usefulness of such random velocity fields in simulations is that we can create random velocity fields with desired statistical properties, thus generating artificial images of realistic turbulent flows. This model also captures the clustering phenomenon of preferential concentration, observed in real world and numerical experiments, i.e. particles cluster in regions of low-vorticity and high-strain rate. We prove almost sure existence and uniqueness of particle paths and give sufficient conditions to rewrite this system as a random dynamical system with a global random pullback attractor. Finally, we visualize the random attractor through a numerical experiment.     

Depth profiling for the identification of unknown substances and concealed content at remote distances using time-resolved stand-off Raman spectroscopy

Time-resolved stand-off Raman spectroscopy was used to determine both the position and identity of substances relative to each other at remote distances (up to tens of meters). Spectral information of three xylene isomers, toluene, and sodium chlorate was obtained at a distance of 12 m from the setup. Pairs and triplets of these samples were placed at varying distances (10-60 cm) relative to each other. Via the photon time of flight the distance between the individual samples was determined to an accuracy of 7% (corresponding to a few cm) of the physically measured distance. Furthermore, at a distance of 40 m, time-resolved Raman depth profiling was used to detect sodium chlorate in a white plastic container that was non-transparent to the human eye. The combination of the ranging capabilities of Raman LIDAR (sample location usually determined using prior knowledge of the analyte of interest) with stand-off Raman spectroscopy (analyte detection at remote distances) provides the capability for depth profile identification of unknown substances and analysis of concealed content in distant objects. To achieve these results, a 532 nm laser with a pulse length of 4.4 ns was synchronized to an intensified charge-coupled device camera with a minimum gate width of 500 ps. For automated data analysis a multivariate curve resolution algorithm was employed.     

High performance hard carbon coatings (diamond‐like coatings)

Different dLc coating types are applied at an industrial scale by sulzer Metco thin Film. The coatings are generated with different coating architecture. Deposition methods are: magnetron sputtering, electron beam evaporation and PA‐cVd. Reactive magnetron sputtering is used to deposit metal containing a‐c:h coatings (a‐c:h:Me), e.g. MAXit W‐ch. Pure a‐c:h coatings as functional top coatings are used for cavidur®, MAXit® AhdLc and special versions of dylyn® coatings. In addition to the pure a‐c:h coatings, doped a‐c:h coatings are also used. The dylyn® family of coatings is comprised of at least one layer a‐c:h:si:O. The dylyn® coatings may be doped with metal (a‐c:h:ti:si:O) to adapt selected properties like electrical conductivity.     

Modeling of glass sintering applied for the fabrication of porous glass bodies

The sintering behavior of borosilicate and soda-lime mono-sized glass beads was investigated with the aim to fabricate transparent porous glass balls and cylinders. As the glasses tend to crystallize, temperatures where the sintering was in advantage compared to crystallization were used. Isothermal studies were undertaken for modeling the evolution of sintering necks as a function of radii of beads, temperature and time. The Frenkel model of viscous flow was applied to predict first and second stage of sintering. As the sintering of the glasses without crystallization was only possible at high temperatures the process is very fast and has to be controlled precisely. The results of this work were applied for the fabrication of porous bodies with specific characteristics: different geometries and sizes, transparency, high porosities to be achieved during first stage sintering of spherical glass beads. The porous parts with these characteristics are used for the investigation of hydrodynamic processes in the pore network of glass parts.     

Entwicklung eines webbasierten Dokumentenmanagement-Systems für eine Fluggesellschaft

Ohne Zusammenfassung Zuschriften zum Studierendenforum bitte an: Universit?t Bayreuth Lehrstuhl BWL VII (Wirtschaftsinformatik) Prof. Dr. Torsten Eymann Redaktion Studierendenforum z. Hd. Dipl.-Wirtschaftsinformatiker Stefan K?nig Universit?tsstra?e 30 95447 Bayreuth E-Mail: stefan.koenig@uni-bayreuth.de     

Simlab 1 - A Laboratory Workflow Recorder for Process Assessment

Process management and workflow optimisation have become key issues of good laboratory management and now seem to be predominant over traditional challenges such as the quality of analytical testing. The first author of this paper has conducted several workflow optimisation studies for clinical laboratories in Europe (Universities of Zurich and Amsterdam, Manchester Royal Infirmary and others) and in the US (University of Virginia), using a laboratory-specific simulation software called Simlab™ for realistic computer modeling of laboratory scenarios. Since data input and calibration of the models against reality have always been a challenge in these studies, we looked into possibilities of using automated data extraction to extract as much information as possible from the laboratory information system. In this paper we describe our first experience with a Microsoft Excel™-based software program called Simlab 1, which uses the ASCII file transfer protocol to extract data from the LIS.     

Effect of MOVPE growth interruptions on the gallium arsenide interior interface morphology

We have studied MOVPE-grown interior GaAs/AlAs interfaces using highly selective etching combined with atomic force microscopy. We observe substantial restructuring for samples grown on both (100) exact and vicinal substrates. Interface structures differ significantly from sample surfaces after cool-down. On (100) exact substrates, the macroscopic monolayer island and terrace structure smoothes during growth interruptions over the whole 2 min period of time studied. A new, mesoscopic scale of roughness is detected for the first time. This structure does not depend on growth interruption time but does change its typical size at different growth temperatures. On vicinal substrates, we observe and quantify step bunching during growth interruption. The growing surface itself is smooth, in sharp contrast to the corresponding macrostepped GaAs sample surface obtained after cooling down.