Micro- and macromixing studies in two- and three-phase (gas-solid-liquid) stirred chemical reactors

The iodide/iodate reaction scheme was used to study the effect of gas sparging and/or solid particles on micromixing in a stirred vessel. A literature review illustrated the need for focused work on this matter and gave valuable ideas for the experiments. For this, the experimental method was first validated for using the added gaseous and solid phases air and glass beads, respectively. The experiments covered a range of conditions for micromixing in single-phase, for validation, in gas-liquid, solid-liquid and gas-solid-liquid systems: power inputs up to 1.94 W/kg, gas sparge rates up to 1.5 vvm and up to 11.63 wt.% solids with diameters from 150 to 1125 μm. For comparison, the power inputs from the impeller were kept constant when affected by the added phase(s). In order to allow better quantification of the experimental data, variations of the Incorporation model were evaluated for taking recent suggestions for the reaction scheme into consideration. The second dissociation of sulphuric acid was included in the model and different kinetic rate laws from the literature on the Dushman reaction were implemented. These variations allowed order-of-magnitude estimates and further comparisons of local specific energy dissipation rates

Characterization of the biological clock in Svalbard ptarmigan (Lagopus muta hyperborea)

Svalbard ptarmigan (Lagopus muta hyperborea), permanent inhabitants of the High Arctic, lose daily behavioral rhythmicity during polar day and night, and rhythms in core body temperature (Tb) weaken after prolonged exposure to constant photic conditions. A weak circadian system has been suggested in Svalbard ptarmigan, however, the molecular clockwork in Svalbard ptarmigan has not been investigated yet. Here, we studied activity and Tb in Svalbard ptarmigan after controlled changes in light conditions and examined the molecular dynamics of the clock. We show that daily rhythms in locomotor and feeding activity in Svalbard ptarmigan stop after a transition from external light-dark cycles (LD) to constant dark (DD)/constant light (LL), while rhythms in Tb persisted for at least 10 days in all experimental birds. Approximately four days after a transition from DD to LD birds showed a rise in Tb in anticipation of light onset. These findings suggest an endogenous timing system in control of Tb under LD that weakens under constant conditions. A sustained ultradian rhythmicity was present during the entire experimental design, however, the underlying mechanisms driving ultradian rhythms in Svalbard ptarmigan remain unclear. To investigate the molecular dynamics of the clock we performed luciferase promoter reporter assays and qPCRs with Svalbard ptarmigan skin fibroblasts. We observed daily oscillations in Per2 and Bmal1 transcription, however, no rhythmicity in clock gene expression was measured by qPCRs. This discrepancy may reflect the high temperature sensitivity of our promoter reporters to small temperature fluctuations we detected in our equipment. Finally, we show that ptarmigan fibroblasts cycle with simulated body temperature cycles with Per1 and Bmal1 transcription being in phase, indicating a response to temperature cycles rather than to an endogenous clock. Taken together, these findings argue for a weak circadian system in Svalbard ptarmigan

‘Muhajirun’ from Austria. Why they left to join ISIS and why they don’t return.

After the proclamation of the so-called Islamic State in June 2014 thousands of Europeans, including hundreds of Austrian residents, went to fight and live with ISIS or other extremist groups in Syria or Iraq. Austria is one of the European countries with the highest per-capita share of foreign fighters. The article gives a broad overview of the situation in Austria: Who are the different groups relevant in this field? How did young people who grew up in Austria become radicalised, and what is their current status? The data from two Austrian commissioned research projects and one EU-funded project are supplemented by the findings of recent research in northern Syria focusing on the current situation of Austrian foreign fighters and their families and supporters in the region

Dynamic Guidance by Colored Running Lights and Affordance: Route Choices of Adults and Older Children

Abstract Guidance to emergency exits play an important role for safe evacuation. Dynamic route guidance by colored flashing lights and strobe lights at emergency exits has been tested [1–3], but the effects of dynamic lights to support route choices need to be determined in more detail. Also, the guidance effects of different colors need to be examined and the reaction of various groups of evacuees. The paper analyzes the effects of red and green running lights on route choice in subway stations comparing adults and older children (10 to 12 years old). Data was gathered in a laboratory experiment, focusing on the concept of affordance [4, 5]. Participants were asked to make a decision about the safest direction between two alternative directions. Their choice was either unsupported or supported by red or green running lights. In general, an interaction between color and direction of the running light was found. Green running lights influenced route choices of both participant groups and led participants clearly into the direction indicated by the lights. Red running lights influenced route choices of both participant groups, but red lights lead to ambiguous decisions. Architectural elements such as stairs influenced route choices of both participant groups (functional affordance). But green running light offered a stronger indication to a safe route (cognitive affordance) than a visible staircase (functional affordance). Green lights even led participants to modify their route preference. In contrast, red running lights had an aversive effect: older children chose against the lights and preferred the other direction than the red lights were directing to. Implications for design of dynamic route guidance are discussed. This includes colored running lights to lead evacuees to a safe exit and to implement the influence of running lights on route choice and movement in simulations

Safe Evacuation for All A top 10 List of Requirements

Evacuations are an important aspect of emergency planning. Many persons with special needs could reach a safe area on their own or with assistance by other people around, if evacuation planning and guidance considered them. The so-called self-rescue is crucial for safe evacuation, as fire services and other first-responders need some time to arrive at the scene. In general, people should find the conditions to arrive at a safe area on their own. In many buildings and infrastructures today, self-rescue is difficult for persons with special needs, e.g. wheelchair users. Sometimes it appears that designers and fire safety engineers only think of “average”, healthy and agile people in evacuations. But for safe and effective evacuations, different groups of people and their needs have to be considered. The paper suggests a top 10 list of requirements for safe evacuation and improvement of self-rescue from a psychological point of view. Universal Design or Design for All in evacuation has become more relevant in recent times, since accessibility as a political goal has made it possible for persons with special needs to participate more easily in public life. Nonetheless, regulations focus on how people enter a building but not on how to evacuate safely. Preparing for safer evacuations requires knowledge about different occupant groups and their needs. Requirements for different phases of evacuations are discussed and their implications for simulation and modelling, e.g. the potential impact of physiological requirements. The need for a multi-method approach to gather and integrate data, factors to foster safe evacuations, just as practical and design requirements are included. When self-rescue is not possible, assisted evacuation will rely on good leadership fostering social motivation. Last but not least, implementing design for all will help everyone to evacuate safely