WoT model for authenticity contents in virtual learning platforms

The following research proposal seeks to bring a model of security software on virtual learning platforms LCMS under all SCORM specifications to ensure the authenticity of content created under concepts of digital signature and identification of protocols and mechanisms to ensure such activities

Systematic XAS study on the reduction and uptake of Tc by magnetite and mackinawite

The mechanisms for the reduction and uptake of Tc by magnetite (Fe3O4) and mackinawite (FeS) are investigated using X-ray absorption spectroscopy (XANES and EXAFS), in combination with thermodynamic calculations of the Tc/Fe systems and accurate characterization of the solution properties (pHm, pe, [Tc]). Batch sorption experiments were performed under strictly anoxic conditions using freshly prepared magnetite and mackinawite in 0.1 M NaCl solutions with varying initial Tc(VII) concentrations (2 × 10−5 and 2 × 10−4 M) and Tc loadings (400–900 ppm). XANES confirms the complete reduction of Tc(VII) to Tc(IV) in all investigated systems, as predicted from experimental (pHm + pe) measurements and thermodynamic calculations. Two Tc endmember species are identified by EXAFS in the magnetite system, Tc substituting for Fe in the magnetite structure and Tc–Tc dimers sorbed to the magnetite {111} faces through a triple bond. The sorption endmember is favoured at higher [Tc], whereas incorporation prevails at low [Tc] and less alkaline pH conditions. The key role of pH in the uptake mechanism is interpreted in terms of magnetite solubility, with higher [Fe] and greater recrystallization rates occurring at lower pH values. A TcSx-like phase is predominant in all investigated mackinawite systems, although the contribution of up to 20% of TcO2·xH2O(s) (likely as surface precipitate) is observed for the highest investigated loadings (900 ppm). These results provide key inputs for an accurate mechanistic interpretation of the Tc uptake by magnetite and mackinawite, so far controversially discussed in the literature, and represent a highly relevant contribution to the investigation of Tc retention processes in the context of nuclear waste disposal

Adquisición de datos con tecnología IoT LoraWAN para monitoreo de turbinas eólicas bio-inspiradas en zonas rurales de Cundinamarca

Context: The energy crisis is a global problem. In Colombia, research aimed at the efficient use of renewable energies is being conducted. For example, in the case of bio-inspired wind generators, a monitoring system is required to observe the output variables (voltage and frequency). Method: LoRaWAN technologies are used to deploy the wireless link since the generators are separated from the base station. In addition, the Gateway coverage area is simulated with HTZ Communications software for future smart grid improvements. Results: The implemented system allows constant monitoring over a long period of time and stores its information in online, open-source databases, which allows remotely visualizing the status of the network, with a total of 3 samples per minute and a range of up to 3,47 km. Conclusions: The data acquisition system can be implemented for remote monitoring. Moreover, since it is a low power system, it can be utilized in non-interconnected areas, as well as for storing data for up to 6 months. However, for the characterization of a model of wind generators, it is advisable to modify the system so that the sampling time is lower.Contexto: La crisis energética es una problemática global. En Colombia se están realizando investigaciones para el aprovechamiento eficiente de energías renovables. Por ejemplo, en el caso de generadores eólicos bio-inspirados, se requiere un sistema de monitoreo para observar variables de salida (voltaje y frecuencia). Método: Se utilizan tecnologías LoRaWAN para el despliegue del enlace inalámbrico, ya que los generadores están separados de la estación base. Además, la zona de cobertura del Gateway se construye en el software HTZ Communications para futuras mejoras en la red inteligente. Resultados: El sistema implementado permite realizar un monitoreo constante por periodos de tiempo prolongados y almacena su información en bases de datos online de código abierto, lo cual permite visualizar el estado de la red de forma remota, con un total de 3 muestras por minuto y un alcance de hasta 3,47 km. Conclusiones: El sistema de adquisición de datos puede ser implementado para monitoreo remoto. Adicionalmente, dado que es un sistema de baja potencia, puede utilizarse en zonas no interconectadas, así como para almacenar datos hasta por 6 meses. Sin embargo, para la caracterización de un modelo de generadores eólicos, es aconsejable modificar el sistema para que el tiempo de muestreo sea menor

Trust Levels Definition on Virtual Learning Platforms Through Semantic Languages

Trust level concept is a topic that has opened a knowledge area about the profile evaluation and the people participation in Social Networks. These have presented a high knowledge profit, but at the same time it is necessary to analyze a group of variables to determine the trust participants' degree. In addition, this is a topic that from some years ago has been presenting a big expectation to settle some alternatives to generate confidence in an activer community on internet. To establish these parameters it is important to define a model to abstract some variables that are involved in this process. For this, it is relevant to take into account the semantic languages as one of the alternatives that allow these kinds of activities. The purpose of this article is to analyze the Trust Levels definition in the contents that are shared on Open Source Virtual learning Platforms through the use of a model of representation of semantic languages. The last ones allow determining the trust in the use of learning objects that are shared in this kind of platforms

Recent advances in the aqueous chemistry of the calcium(II)-gluconate system – Equilibria, structure and composition of the complexes forming in neutral and in alkaline solutions

Of the sugar carboxylates, D-gluconate is clearly the most significant representative: the world’s annual production of this organic compound is estimated to be in the order of 10$^{5}$ tonnes. The reason of its mass production is due to its outstandingly broad range of practical (medical, pharmaceutical, industrial, etc.) applications. D-gluconate is a well-known and exceptionally popular complexing agent; accordingly, it has been the subject of a large number of coordination chemical research investigations. Its complexation properties are specially remarkable in alkaline to hyperalkaline pH conditions, where the deprotonation of one or more of its alcoholic OH groups provides a favourable frame for the formation of very stable chelate complexes with a large variety of metal cations. With the aim to show the state of the art of some relevant issues in the aqueous chemistry of the D-gluconate ion, the current paper focusses on the acidbase properties and calcium(II) complexation of the compound encompassing the entire experimentally available pH-range in water. The accessible literature on the deprotonation of carboxylic and alcoholic OH groups is collected and critically evaluated. The lactonization equilibria of D-gluconic acid are also scrutinized. The available data on the calcium complexes forming in neutral and in (hyper)alkaline solutions (both in terms of composition, formation constants and solution structure) are also discussed. Where feasible, some of these properties are compared with those of D-glucose and its derivatives as well as some less common sugar carboxylates, structurally related to D-gluconate, (i.e., D-heptagluconate, Lgulonate and α-D-isosaccharinate). Special emphasis is laid on the relationship between complex stability and the type of metal-binding groups