Positively Charged Iridium(III) Triazole Derivatives as Blue Emitters for Light‐Emitting Electrochemical Cells

Cationic blue‐emitting complexes with (2,4‐difluoro)phenylpyridine and different 1,2,3‐triazole ligands are synthesized with different counterions. The influence of the substituents on the triazole ligand is investigated as well as the influence of the counterions. The substituents do not change the emission energy but, in some cases, slightly modify the excited‐state lifetimes and the emission quantum yields. The excited‐state lifetimes, in apolar solvents, are slightly dependent on the nature of the counterion. A crystal structure of one of the compounds confirms the geometry and symmetry postulated on the basis of the other spectroscopic data. Light‐emitting electrochemical cell devices are prepared and the recorded emission is the bluest with the fastest response time ever reported for iridium complexes.     

Generalized “satisfaction of search”: Adverse influences on dual-target search accuracy.

The successful detection of a target in a radiological search can reduce the detectability of a second target, a phenomenon termed satisfaction of search (SOS). Given the potential consequences, here we investigate the generality of SOS with the goal of simultaneously informing radiology, cognitive psychology, and nonmedical searches such as airport luggage screening. Ten experiments utilizing nonmedical searches and untrained searchers suggest that SOS is affected by a diverse array of factors, including (1) the relative frequency of different target types, (2) external pressures (reward and time), and (3) expectations about the number of targets present. Collectively, these experiments indicate that SOS arises when searchers have a biased expectation about the low likelihood of specific targets or events, and when they are under pressure to perform efficiently. This first demonstration of SOS outside of radiology implicates a general heuristic applicable to many kinds of searches. In an example like airport luggage screening, the current data suggest that the detection of an easy-to-spot target (e.g., a water bottle) might reduce detection of a hard-to-spot target (e.g., a box cutter). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A System under Stress: The Icelandic Volcano Ash Crisis

This paper analyzes the response to the Icelandic volcano ash crisis of 2010. We examine how the original response was determined by the formal organization of the European air traffic control system, how the crisis was defined, what characterized the or new regulatory regime, and how one can explain the development and handling of the crisis. The theoretical basis is a combination of instrumental organization theory and crisis management theories. The crisis is handled via established organizational arrangements and principles that impose limits on the scope of action. The response to the crisis involved fine‐tuning in the form of an instrumental and incremental adaptation of policies, regulations and practices challenging core political values, which also exhibit elements of path dependency.     

Structure and performance of soy hull carbon adsorbents as affected by pyrolysis temperature

Soy hulls were evaluated as a source of adsorbent carbon for vegetable oil processing. Soy hull carbon was prepared by burning ground soy hulls (<100 mesh) at 300, 400, 500, or 700°C in a muffle furnace. The structure of the soy hull carbon was studied by scanning electron microscope (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR). Crude soy oil was processed with the soy hull carbon products at 2% (w/w) in the laboratory under commercial bleaching conditions. Free fatty acids (FFA), peroxide value, phospholipid phosphorus (PLP), and lutein content of the treated samples were determined. SEM of the samples revealed particle size ranging from 1 to 2 mm. Increasing the pyrolysis temperature resulted in expansion and disruption of cellular structure. FTIR spectra of the carbon samples showed major differences in peak intensities at 3600 to 3200, 1600, and 1450 cm⁻¹ due to pyrolysis temperature. XRD revealed a predominantly amorphous structure with increasing pyrolysis temperature, which also resulted in an increased alkaline surface. Soy hull carbon decreased the FFA content of oil samples compared to that of crude oil, with the exception of carbon that was prepared at 300°C (P<0.05). A similar trend was observed in the adsorption of peroxides; however, no trends were observed in the adsorption of PLP or lutein. Higher pyrolysis temperature decreased randomness of the carbon and imparted a certain degree of structural order. This may be beneficial in providing physical access of the adsorbate molecule to the adsorbent surface.     

Microstructure, Phase and Thermoelastic Properties of Laminated Liquid-Phase-Sintered Silicon Carbide–Titanium Carbide Ceramic Composites

Hot-pressed silicon carbide–titanium carbide (SiC—TiC) composites sintered with liquid-phase forming Al₂O₃ and Y₂O₃ mixtures have been studied. Samples were fabricated by successively stacking tape-cast sheets of a single composition, resulting in a laminated body of uniform composition. This approach required the development of a technology easily transferable into the production of functionally graded SiC–TiC materials. The effects of this processing route on the resultant microstructures and phases were explored in detail. Additionally, because of the consequences for graded materials, the effects of TiC proportion on the thermal expansion coefficients, Young's modulus, and Poisson's ratios for several SiC–TiC composites were also determined.     

Passive room conditioning using phase change materials—Demonstration of a long-term real size experiment

The thermal properties of lightweight buildings can be efficiently improved by using phase change materials (PCMs). The heat storage capacity of the building can be extended exactly at the desired temperature level, which leads to an enormous increase in residential comfort. This is shown in the present paper using the example of a prefabricated wooden house. The house was divided into two identical rooms. One of them was equipped with almost one ton of phase change material based on salt hydrates with a melting temperature of approx. 21°C. The material was encapsulated in 1-l Polyethylene containers and installed in two back-ventilated layers inside of the walls. The house was monitored for a period of 87 days in terms of temperatures, solar radiation and air velocity inside the PCM wall system. A considerable temperature buffering could be observed in the PCM room compared to the reference room. An overall reduction of the temperature fluctuations of 57% and a reduction of the day/night fluctuations of 62% compared to the reference room could be obtained. In addition, a prediction regarding the energy demand of such buildings is discussed on the basis of a simulation program. Thus, the annual cooling capacity can be reduced by 36.5% compared to the regular timber construction technique by introducing PCM. Furthermore, the good correlation of the simulation results with the experimental ones allows using the simulation as a tool to design a house with additional thermal storages.     

Coupling membrane filtration and wet air oxidation for advanced wastewater treatment: Performance at the pilot scale and process intensification potential

Bio-refractory wastewater treatment is compulsory for a safe discharge into the environment. This paper aims to study the use of membrane processes to concentrate wastewater to be then treated by a hydrothermal process such as wet air oxidation for advanced and intensified wastewater treatment. The work focused on three different synthetic wastewaters of public or industrial interest: pharmaceutical wastewater, grey wastewater, and bilge wastewater. Membrane processes operated at the pilot scale enabled retentions as high as 100% of total organic carbon, more than 99% of turbidity, and 70% of hydrocarbon, respectively. High concentration factors were obtained. Membrane foulings were chemically reversible whatever the type of wastewater or the membrane process. Thanks to membrane filtrations, the volumes to be treated by wet air oxidation were drastically reduced, leading to high energy savings. Membrane retentates were then treated by wet air oxidation (300°C, 15 MPa) and resulted in more than an 83% mineralization rate, regardless of the effluent. The hybrid intensified process presented in this work strongly increased the possibility of discharging into the environment by mixing the process outputs or greatly reducing the discharge volume and ultimately the waste load.     

Die Bedeutung der Tragwerkseigenschaften im Gesamtsicherheitskonzept – am Beispiel der Dachkonstruktion der AWD‐Arena in Hannover

The significance of structural behaviour in the global safety concept exemplified at the roof construction of the AWD Arena in Hanover. The wide‐span roof structures of modern sports arenas demand a high level of safety. So the assessment of structural behaviour, “robustness” and residual load‐bearing capacity, as specified in the Eurocodes (EC 1), in the new DIN 1055 part 100 [1] and in the DIN 18800 part 1 [2], becomes a central part of the global static analysis. The appropriate safety factors for these structures cannot be determined in advance but only after having analyzed the structural sensitivities in relation to the load parameters, especially those of climatic loads. The present work shows the contribution of the structural analysis to a complex team‐work of wind and snow experts, checking and approving authorities exemplified at the AWD Arena roof.     

Influence of test parameters on tribological measurements ‐ results from international round robin tests

A series of cooperative interlaboratory tests (‘round robins’) was conducted in 1997, 1998, 1999, 2000, and 2001 by the DIN 51834 Working Group on Tribological Tests in Translatory Oscillation Apparatus. Statistical analysis of these results showed the influence of cleaning solvent, machine model, and evaluation criteria on the tribological properties of the lubricants tested. Coefficients of friction and wear results were ranked according to the effects of ten different cleaning solvents, where isopropanol gave the lowest values and isoparaffin solvents the highest. The effect of machine model on coefficients of friction varied from about 0.2 to 0.9% of the average. Wear results were not affected. The tests also showed that the seizure criteria and methods of measuring wear required in the test procedure do not provide a suitable measure of the tribological properties of certain lubricants.