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Este trabajo se centra en el modelado mediante TRNSYS de una bomba de calor geotérmica agua-agua que utiliza CO2 como refrigerante para producir agua caliente sanitaria (ACS), para posteriormente hacer un estudio comparativo con una instalación solar. Dicha instalación se encuentra disponible en el laboratorio de Calor y Frío del ELDI. Los objetivos principales del trabajo son: - Estudiar y entender el funcionamiento de la bomba de calor y de todos sus componentes. - Conocer las ventajas que presente el CO2 como refrigerante. - Búsqueda de información acerca de los sistemas de captación de energía geotérmica. - Modelar los componentes que constituyen una bomba de calor geotérmica. - Programar los modelos seleccionados mediante el compilador FORTRAN. - Simulación de la bomba de calor en TRNSYS a partir de los componentes programados que la forman. - Realizar un estudio comparativo con un sistema solar convencional a base de colectores solares. ; Escuela Técnica Superior de Ingeniería Industrial ; Universidad Politécnica de Cartagena

Abstract. Flooding in the Amazon basin is frequently attributed to modes of large-scale climate variability, but little attention is paid to how these modes influence the timing and duration of floods despite their importance to early warning systems and the significant impacts that these flood characteristics can have on communities. In this study, river discharge data from the Global Flood Awareness System (GloFAS 2.1) and observed data at 58 gauging stations are used to examine whether positive or negative phases of several Pacific and Atlantic indices significantly alter the characteristics of river flows throughout the Amazon basin (1979–2015). Results show significant changes in both flood magnitude and duration, particularly in the north-eastern Amazon for negative El Niño–Southern Oscillation (ENSO) phases when the sea surface temperature (SST) anomaly is positioned in the central tropical Pacific. This response is not identified for the eastern Pacific index, highlighting how the response can differ between ENSO types. Although flood magnitude and duration were found to be highly correlated, the impacts of large-scale climate variability on these characteristics are non-linear; some increases in annual flood maxima coincide with decreases in flood duration. The impact of flood timing, however, does not follow any notable pattern for all indices analysed. Finally, observed and simulated changes are found to be much more highly correlated for negative ENSO phases compared to the positive phase, meaning that GloFAS struggles to accurately simulate the differences in flood characteristics between El Niño and neutral years. These results have important implications for both the social and physical sectors working towards the improvement of early warning action systems for floods.

The objective of this work is to valorise the discharges (rejections) of the Boukhedra iron ore mine (east of Algeria) as raw materials for the elaboration of the cement raw. The study concerns the development of different types of low impact environmental belite cements whose raw are exclusively mine rejections. The use of a low CaO / SiO2 ratio and the combination of quick cooling of clinker with adequate NaF and LiF mineralization in association with CaSO4, has led to the production of belite cement with high hydraulic reactivity comparable to that of ordinary Portland cements. The used mineralization plays also a positive role in improving performance in terms of firing of the raw, by lowering the clinker process temperatures of these cements, thus, enabling an additional gain in terms of environmental impact and energy consumption. This mineralization and the low LSF of these cements allows obtaining them at low burning temperatures 1150 °C and 1100 °C for the cement with 2%LiF. This is 350 °C lower to ordinary Portland cement. The addition of CaSO4, NaF and LiF to the clinkers makes the improvement of its clinkering possible. The effect of LiF seems to be the most significant followed by NaF and finally, CaSO4

The energy considered as waste heat in industrial furnaces owing to inefficiencies represents a substantial opportunity for recovery by means of thermal energy storage (TES) implementation. Although conventional systems based on sensible heat are used extensively, these systems involve technical limitations. Latent heat storage based on phase change materials (PCMs) results in a promising alternative for storing and recovering waste heat. Within this scope, the proposed PCM-TES allows for demonstrating its implementation feasibility in energy-intensive industries at high temperature range. The stored energy is meant to preheat the air temperature entering the furnace by using a PCM whose melting point is 885 °C. In this sense, a heat transfer model simulation is established to determine an appropriate design based on mass and energy conservation equations. The thermal performance is analysed for the melting and solidification processes, the phase transition and its influence on heat transference. Moreover, the temperature profile is illustrated for the PCM and combustion air stream. The obtained results prove the achievability of very high temperature levels (from 700 to 865 °C) in the combustion air preheating in a ceramic furnace; so corroborating an energy and environmental efficiency enhancement, compared to the initial condition presenting an air outlet at 650 °C.

At the 1972 Stockholm Conference, participating States expressed concern about the extent and consequences of air pollution, laying the groundwork for international legal cooperation to address it. The Action Plan for the Human Environment included the need to promote scientific observation of the atmosphere, and the principles set out in the Stockholm Declaration served, as in other areas of environmental international law, to articulate the response to the threats identified. Since that meeting, the evolution of international legal protection of the atmosphere has been marked by the implementation of three international regimes. The European regime on transboundary air pollution, inaugurated in 1979, was the first model of international cooperation in this field, and influenced subsequent developments in the regimes on ozone layer protection and climate change. Taking into account the foundational impetus that the Stockholm Conference provided for the development of these regimes, this paper analyses the evolution of international legal protection of the atmosphere in the fifty years since the Conference was held

Recycled polylactic acid (PLAr) was reinforced with treated nanocellulosic hemp fibers for biocomposite fabrication. Cellulosic fibers were extracted from hemp fibers chemically and treated enzymatically. Treated nanocellulosic fibers (NCF) were analyzed by Fourier-transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. Biocomposite fabrication was done with PLAr and three concentrations of treated NCF (0.1%, 0.25%, and 1% (v/v)) and then studied for thermal stability and mechanical properties. Increased thermal stability was observed with increasing NCF concentrations. The highest value for Young’s modulus was for PLAr + 0.25% (v/v) NCF (250.28 ± 5.47 MPa), which was significantly increased compared to PLAr (p = 0.022). There was a significant decrease in the tensile stress at break point for PLAr + 0.25% (v/v) NCF and PLAr + 1% (v/v) NCF as compared to control (p = 0.006 and 0.002, respectively). No significant difference was observed between treatments for tensile stress at yield.

With the aim to fully exploit the by-products obtained after the industrial extraction of starch from sweet potatoes, a cascading approach was developed to extract high-value molecules, such as proteins and pectins, and to valorize the solid fraction, rich in starch and fibrous components. This fraction was used to prepare new biocomposites designed for food packaging applications. The sweet potato residue was added to poly(3-hydroxybutyrate-co-3-hydroxyvalerate) in various amounts up to 40 wt % by melt mixing, without any previous treatment. The composites are semicrystalline materials, characterized by thermal stability up to 260 °C. For the composites containing up to 10 wt % of residue, the tensile strength remains over 30 MPa and the strain stays over 3.2%. A homogeneous dispersion of the sweet potato waste into the bio-polymeric matrix was achieved but, despite the presence of hydrogen bond interactions between the components, a poor interfacial adhesion was detected. Considering the significant percentage of sweet potato waste used, the biocomposites obtained show a low economic and environmental impact, resulting in an interesting bio-alternative to the materials commonly used in the packaging industry. Thus, according to the principles of a circular economy, the preparation of the biocomposites closes the loop of the complete valorization of sweet potato products and by-products.