Kinetic study of the hydrolysis of isocyanic acid in the gas phase

The hydrolysis of isocyanic acid in the gaseous phase has been investigated at temperatures between 553 and 613 K by mass spectrometry and evaluated to obtain the corresponding kinetic data. The reaction order and reaction constant have been determined. Finally, the influence of water on the catalysed formation of melamine from isocyanic acid under the operating conditions employed has been investigated in order to determine whether there is a need to try the process gas.     

To Score or Not to Score? Tripling Insights for Participatory Design

For evaluating visual-analytics tools, many studies confine to scoring user insights into data. For participatory design of those tools, we propose a three-level methodology to make more out of users' insights. The Relational Insight Organizer (RIO) helps to understand how insights emerge and build on one each other.     

Visual methods for analyzing time-oriented data

Providing appropriate methods to facilitate the analysis of time-oriented data is a key issue in many application domains. In this paper, we focus on the unique role of the parameter time in the context of visually driven data analysis. We will discuss three major aspects - visualization, analysis, and the user. It will be illustrated that it is necessary to consider the characteristics of time when generating visual representations. For that purpose we take a look at different types of time and present visual examples. Integrating visual and analytical methods has become an increasingly important issue. Therefore, we present our experiences in temporal data abstraction, principal component analysis, and clustering of larger volumes of time-oriented data. The third main aspect we discuss is supporting user-centered visual analysis. We describe event-based visualization as a promising means to adapt the visualization pipeline to needs and tasks of users.     

Soot predictions in premixed and non-premixed laminar flames using a sectional approach for PAHs and soot

A new soot model is presented, which has been developed for CFD applications, combining accuracy and efficiency. While the chemical reactions of small gas phase species are captured by a detailed chemical kinetic mechanism, polycyclic aromatic hydrocarbons (PAHs) and soot particles are represented by sectional approaches. The latter account for important mechanisms such as the formation of sections, their oxidation, the condensation of acetylene, and the collisions between sections. The model has been designed to predict soot for a variety of fuels with good accuracy at relatively low computational cost. Universal model parameters are applied, which require no tuning in dependence of test case or fuel. Soot predictions of ethylene, propylene, kerosene surrogate, and toluene flames are presented, which show good agreement with the experimental data. Furthermore, the importance of the correct choice for thermodynamic data of PAHs and soot is highlighted and the impact of heat radiation is discussed.     

Current drive methods to extend the range of travel ofelectrostatic microactuators beyond the voltage pull-in point

When a voltage source drives an electrostatic parallel plate actuator, the well-known pull-in instability limits the range of displacement to 1/3 of the gap. Different strategies have been reported to overcome this limitation. More recently, experimental results have been presented using a capacitor in series with the actuator. Nevertheless, this strategy requires higher voltage than the pull-in voltage value to achieve full range of travel. In order to reduce the operating voltage, a switched-capacitor configuration has been also proposed. In this paper, two different approaches are introduced to control charge in the actuator by means of current driving. Theoretical equations derived for each method show that full range of travel can be achieved without voltage penalty. Both approaches are based on the use of current pulses injecting the required amount of charge to fix the position of the movable plate. Experimental measurements, showing that displacement beyond the pull-in point can be achieved, are in good agreement with the theoretical and the predicted simulated behavior     

Multifunctional Magnetic Optical Sensor Particles with Tunable Sizes for Monitoring Metabolic Parameters and as a Basis for Nanotherapeutics

Magnetic optical sensor particles with multifunctional cores and shells are synthesized via a facile nanoprecipitation method and the subsequent modification of the particle shell. The hydrophobic particle core includes optical oxygen indicators, a light harvesting system, photosensitizers, and magnetic nanoparticles. Further functionalities are introduced by modifying the shell with enzymes, antibodies, multiple layers of polyelectrolytes, stimuli‐responsive polymers, and luminescent indicator dyes. The hydrodynamic diameter is tunable by varying different precipitation parameters.     

Friction and ablation measurements in a round bore railgun

Detailed experiments were performed in order to determine electrode ablation and friction effects in a round-bore railgun. An accelerating model was developed which includes electrode-ablation effects, the viscous arc drag, and the mechanical friction of the projectile. In addition, a novel nonlinear electrode-ablation model was found to describe the experimental data very well. A model for the mechanical friction force between the projectile and bore wall was applied to the equation of motion. The position/time data of the projectile acceleration could be adjusted with quite reasonable friction effects. Theoretical and experimental results show that the `ideal' projectile velocity is decreased by about 28%: 15% due to electrode ablation, 9% due to mechanical friction, and about 4% due to viscous arc drag     

Erdpunktverlagerungen bei Transkommandotastung in Drehstromnetzen

Ohne Zusammenfassung     

Nordic hydropower flexibility and transmission expansion to support integration of North European wind power

The expected increase of wind power production in the North and Baltic Seas will substantially increase the variability of the generation portfolio in Northern Europe. Access to available resources of flexible power production will be necessary to support the power system against this variability. Since the Nordic hydro‐based power system can provide such resources, a stronger interconnection between continental Europe and the Nordic region seems to be beneficial. This paper assesses the challenges related to wind power production variability, especially offshore, in the North and Baltic Seas. Assessment on the transmission grid needed for both harvesting the available wind production located far away from load centres and to enable the optimal use of hydropower flexibility is studied in a long‐term cost‐benefit analysis. Special focus is devoted to the role of an offshore grid structure and the impact of onshore grid constraints. The analysis includes two interrelated simulation steps. The first step focuses on the strategic use of hydro energy in the day‐ahead market, where detailed modelling of water courses and hydro production in the Nordic region is considered. Then, in a second step, flow‐based simulations are conducted on a detailed grid model for the whole European system. The results show that long‐term strategies for the expansion of offshore and onshore grids must be defined in a coordinated way to ensure optimal developments. Copyright © 2014 John Wiley & Sons, Ltd.