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This research investigates the flight behavior of refuse-derived fuel (RDF) in a drop shaft using Computer Vision to obtain statistical data on the aerodynamic properties of the particles. Methods to determine 3D geometry models of complex-shaped particles by photogrammetry and to obtain time resolved particle positions and velocities are described. Furthermore, an approach to obtain the frequency distribution of drag and lift coefficients from photogrammetric analysis and drop shaft experiments is presented. The image evaluation is based on algorithms of the open-source libraries OpenCV, COLMAP as well as MeshLab and Open3D. The precision of the system is validated employing model particles with known geometry. The 3D particle models overestimate the particle surface area by 4.58 %, the position detection works with a mean deviation of 2.73 %. The average sink rate is calculated with an accuracy of 4.87 % and the drag coefficient with an accuracy of 2.08 %. Finally, the frequency distribution of four RDF fractions, namely, textiles, cardboard, 3D plastic particles and 2D plastic foils are presented.

For layered oxide cathodes, aluminum doping has widely been shown to improve performance, particularly at high degrees of delithiation. While this has led to increased interest in Al-doped systems, including $\mathrm{LiNi_{0.8}Co_{0.15}Al_{0.05}O_{2}}$ (NCA), the aluminum surface environment has not been thoroughly investigated. Using hard x-ray photoelectron spectroscopy measurements of the Al 1s core region for NCA electrodes, we examined the evolution of the surface aluminum environment under electrochemical and thermal stress. By correlating the aluminum environment to transition metal reduction and electrolyte decomposition, we provide further insight into the cathode-electrolyte interface layer. A remarkable finding is that Al-O coatings in LiPF$_6$ electrolyte mimic the evolution observed for the aluminum surface environment in doped layered oxides. ECS transactions 80(10), 197 - 206 (2017). doi:10.1149/08010.0197ecst Published by Pennington, NJ

AbstractWe report a nickel complex for catalytic oxidation of ammonia to dinitrogen under ambient conditions. Using the aryloxyl radical 2,4,6‐tri‐tert‐butylphenoxyl (tBu3ArO⋅) as a H atom acceptor to cleave the N−H bond of a coordinated NH3 ligand up to 56 equiv of N2 per Ni center can be generated. Employing the N‐oxyl radical 2,2,6,6‐(tetramethylpiperidin‐1‐yl)oxyl (TEMPO⋅) as the H‐atom acceptor, up to 15 equiv of N2 per Ni center are formed. A bridging Ni‐hydrazine product identified by isotopic nitrogen (15N) studies and supported by computational models indicates the N−N bond forming step occurs by bimetallic homocoupling of two paramagnetic [Ni]−NH2 fragments. Ni‐mediated hydrazine disproportionation to N2 and NH3 completes the catalytic cycle.

In the 21st century, many countries are starting to use geothermal energy (GTE) as a new energy source. Serbia also has the potential to use it as a renewable energy source. The complex geological structure of its terrain has given rise to a large number of thermomineral springs and geothermal wells. Based on the existing measurements, the geothermal heat flow density in Serbia ranges from 80 to 120 mW/m2, which is above Europe's average (60 mW/m2). Currently, there are 66 projects in Serbia that directly use geothermal energy. There are an estimated 1005 geothermal heat pump units. Their power varies between 10 kW and 40 kW and they operate for 2860 full load hours per year. This paper deals with the development, current state and perspectives of geothermal energy utilization for heating in Serbia. To illustrate the current state of geothermal energy utilization in Serbia, spa settlements Vranjska Banja and Gornja Trepča, as well as the Bogatić Municipality have been singled out as examples of good practice. The presented analysis includes determining the available amount of geothermal energy and its utilization for district heating or heating of selected public facilities. The concept and methodology of the presented research are based on data collection through literature review, surveys and field research. The analysis confirms the cost-effectiveness of using geothermal energy and reveals numerous ecological advantages over other energy sources. However, it was concluded that аlthough there is potential, geothermal sources, as a renewable energy source, are used negligibly in Serbia.