26 research outputs found
Inspire: Challenging the lack of interest in physics among students
The Inspire project tested and analyzed the use of digital Learning resources (LR) in the field of Maths, Science and Technology (MST) in 63 schools in Austria, Germany, Italy, Lithuania and Spain. MST teachers used the LR from a pool of 60 resources (12 for Physics) in class and the effects on teachers and 5â18+ year old students were measured. We found the use of LR increases the understanding of students of MST and allows for differentiated learning within a class. LR have a larger impact on boys than girls, and it decreases with age. Overall, it appears the use of LR has a positive impact on MST education but special attention has to be placed on technical requirements and localization of the LR
Ionic liquids at electrified interfaces
Until recently, âroom-temperatureâ (<100â150 °C) liquid-state electrochemistry was mostly electrochemistry of diluted electrolytes(1)â(4) where dissolved salt ions were surrounded by a considerable amount of solvent molecules. Highly concentrated liquid electrolytes were mostly considered in the narrow (albeit important) niche of high-temperature electrochemistry of molten inorganic salts(5-9) and in the even narrower niche of âfirst-generationâ room temperature ionic liquids, RTILs (such as chloro-aluminates and alkylammonium nitrates).(10-14) The situation has changed dramatically in the 2000s after the discovery of new moisture- and temperature-stable RTILs.(15, 16) These days, the âlater generationâ RTILs attracted wide attention within the electrochemical community.(17-31) Indeed, RTILs, as a class of compounds, possess a unique combination of properties (high charge density, electrochemical stability, low/negligible volatility, tunable polarity, etc.) that make them very attractive substances from fundamental and application points of view.(32-38) Most importantly, they can mix with each other in âcocktailsâ of oneâs choice to acquire the desired properties (e.g., wider temperature range of the liquid phase(39, 40)) and can serve as almost âuniversalâ solvents.(37, 41, 42) It is worth noting here one of the advantages of RTILs as compared to their high-temperature molten salt (HTMS)(43) âsister-systemsâ.(44) In RTILs the dissolved molecules are not imbedded in a harsh high temperature environment which could be destructive for many classes of fragile (organic) molecules
Electroplating of Dysprosium, Electrochemical Investigations, and Study of Magnetic Properties
Electroplating of dysprosium from several nonaqueous solutions and from an ionic liquid was studied. Dysprosium metal was used as the anode material, and several metals and a silicon wafer with a vacuum-deposited gold layer were used as cathode materials. Dysprosium was successfully electroplated from dimethylformamide-based solutions with high coulombic efficiency. The resulting dysprosium layer was effectively protected vs reactions with water and oxygen from air by electroplating an aluminum layer onto dysprosium from a nonaqueous electrolyte. All processes were investigated by electrochemical methods including cyclic voltammetry, chronoamperometry, chronopotentiometry, and with the help of an electrochemical quartz microbalance coupled to an Autolab PGSTAT30 controlled by the GPES software from Eco Chemie B.V., Utrecht, The Netherlands. A nonaqueous reference electrode developed by Izutsu was applied; the diffusion potential was kept low by a slight modification of his original proposal. X-ray fluorescence spectroscopy was used to verify electroplating of Dy. The presence of metallic Dy was also confirmed by superconducting quantum interference device magnetometry which showed a ferromagnetic moment at 5 K
Temperature Dependence of the Non-Stokesian Charge Transport in Binary Blends of Ionic Liquids
Electrode Reaction and Mass-Transport Mechanisms Associated with the Iodide/Triiodide Couple in the Ionic Liquid 1-Ethyl-3-methylimidazolium Bis(trifluoromethanesulfonyl)imide
Material development for dye solar modules: Results from an integrated approach
In this paper, we report on tire outcome of a German network project conducted with 12 partners from universities and research institutes on the material development of dye solar cells (DSC). We give an overview in the field and evaluate the concept of monolithic DSC further with respect to upscaling and producibility oil glass substrates. We have developed a manufacturing process for monolithic DSC modules which is entirely based on screen printing. Similar to our previous experience gained in the sealing of standard DSC, the encapsulation of the modules is achieved in a fusing step by soldering of glass frit layers. For use in monolithic DSC, a platinum free, conductive counter electrode layer, showing a charge transfer resistance of R-CT<1.5 Omega cm(2), has been realized by firing a graphite/carbon black composite under an inert atmosphere. Glass frit sealed monolithic test cells have been prepared using this platinum free material. A solar efficiency of 6% on a 2.0 cm(2) active cell area has been achieved in this case. Various types of non-volatile imidazolium-based binary ionic liquid electrolytes have been synthesized and optimized with respect to diffusion-limited currents and charge transfer resistances in DSC. In addition, quasi-solid-state electrolytes have been successfully tested by applying inorganic (SiO2) physical gelators. For the use in semi-transparent DSC modules, a polyol process has been developed which resulted in tire preparation of screen printed transparent catalytic platinum layers showing an extremely low charge transfer resistance (0-25 Omega cm(2)). Copyright (C) 2008 John Wiley & Sons, Ltd