Making sense of collaboratively annotated Multimedia Metadata for (mobile) digital Story-Telling and Educational Gaming

Abstract. Technology enhanced learning (TEL) is considered a key element for lifelong and cost-effective learning processes. Nowadays, with the rapid development and evolution of the Web 2.0 (e.g. wikis, blogs, etc.) new learning paradigms have emerged. Instead of a simpler model where students consume instructor-written documentation, it appears to be a natural process that users (or learners in this case) may become a prosumer (a combination of producer and consumer). In the context of TEL this implies the creation of a new species: The teaner (a combination of teacher and learner). Additionally, TEL is now exploring alternative forms of content such as story-telling and educational gaming. These two approaches, when combined, can be mutually beneficial, with games bringing the educational stories to life and with the stories providing a solid narrative backbone for the games. In this work, we propose an approach to merge educational gaming, interactive story-telling and collaborative creation of content, glued together by interoperable multimedia metadata. Finally, we discuss aspects of mobile learning and the challenges posed by adding a fourth dimension for the problem: letting teaners go mobile

Application of Fe-MFI zeolite catalyst in heterogeneous electro-Fenton process for water pollutants abatement

International audienc

Fe-Nanoporous Carbon Derived from MIL-53(Fe): A Heterogeneous Catalyst for Mineralization of Organic Pollutants

Catalytic electrodes were prepared via carbonization of MIL-53(Fe) on the surface of porous carbon felt electrodes (CF) for use in wastewater treatment by the heterogeneous electro-Fenton (EF) process. The best results were obtained when the carbon felt was pretreated with nitric acid, enhancing the affinity of the MIL-53(Fe) for the surface. Following a series of optimization experiments, carbonization conditions of 800 °C for 5 h were used to form Fe-nanoporous carbon (MOFs@CF). The as-prepared electrodes were used as both cathode and heterogeneous catalyst in the EF process for the mineralization of exemplar dye Acid Orange 7 (AO7). Total organic carbon (TOC) removal of 46.1% was obtained within 8 h of electrolysis at around neutral pH (6.5) and the electrode retained over 80% of its original efficiency over five treatment cycles

Design of a novel fuel cell-Fenton system: a smart approach to zero energy depollution

International audienceA model azo dye pollutant, Acid Orange 7 (AO7), was removed efficiently from an aqueous medium by a smart eco-friendly Fuel Cell-Fenton (FC-Fenton) system without any external power supply. In this approach, AO7 was degraded by an electro-Fenton process at a designed cathode (Carbon Felt (CF)/porous Carbon (pC)) supplied by direct clean electrical energy from abiotic glucose oxidation at a CF/gold anode (CF@Au). The highly active cathode was fabricated by an attractive route combining Atomic Layer Deposition (ALD) of ZnO on commercial carbon felts (CFs) followed by subsequent solvothermal conversion of the metal oxide to a metal organic framework (here ZIF-8). The as-prepared composite material was further calcined at high temperature under a controlled atmosphere. A pC-based support with high specific surface area and nitrogen as a dopant was thus obtained, enhancing both conductivity and electrocatalytic properties toward H2O2 production from oxygen reduction. Degradation kinetics of AO7 (0.1 mM initial concentration) at the CF@pC cathode was monitored by UV-vis spectrophotometry and High-Performance Liquid Chromatography (HPLC) to prove the efficiency of the composite material for the degradation of such a bio-refractory model molecule. Benefitting from the H2O2 production rate (9.2 mg L−1 h−1) by the pC layer, AO7 (35.0 mg L−1) was degraded by the electro-Fenton process in acidic medium (pH = 3) with removal efficiency reaching 90% in 10 h. The durability of the system was extended for more than 2 months with an average power output of 170 mW m−2, confirming this abiotic FC-Fenton system as a promising, green, future technology for both environmental and energy-related areas, including membrane-coupled reactor systems

Nitrogen-Doped Graphitized Carbon Electrodes for Biorefractory Pollutant Removal

A novel material was fabricated by deposition of graphitized nitrogen-doped porous carbon layer (NPC) on commercial carbon felt (CF). The NPC was obtained via atomic layer deposition of zinc oxide (ZnO) and its subsequent solvothermal conversion to zeolitic imidazolate framework (ZIF-8) followed by its carbonization under controlled atmosphere. Both physical and electrochemical properties have been evaluated by scanning electron microscopy, X-ray diffraction, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, Raman spectroscopy, nitrogen sorption, contact angle, and cyclic voltammetry measurements. The parameters affecting the growth of NPC, such as the amount of ZnO/ZIF-8 material before calcination and thermal treatment temperature, have been investigated in detail. The versatility of the as-prepared NPC/CF material was assessed by studying (i) its adsorption ability and/or (ii) its behavior as cathode in electro-Fenton process (EF) for the elimination of a model refractory pollutant (acid orange 7 (AO7)). Once used as adsorbent, the NPC/CF proved good adsorption capacity with 97% color removal of initial 0.02 mM dye concentration after 30 min. Moreover, the application of such novel cathode could also reduce the cost for EF technology by using lower energy consumption at 0.54 kWh g^–1 TOC (total organic carbon). The apparent rate constant (<i>k</i>_app ∼ 0.8 min^–1) obtained for NPC/CF was more than 7 times higher compared to pristine CF commercial electrode, thus leading to more than 90% TOC removal in 8 h. In addition, high reaction efficiency and system durability were attributed to continuous regeneration of the NPC/CF sorption capacity upon total mineralization of the pollutants accumulated at the electrode surface. Results confirmed that the new NPC/CF material behaves as a highly active electrode with attractive adsorption efficiency and at the same time it possesses an excellent electrochemical activity in the EF oxidation process for the removal of persistent water pollutants