Análisis de Ciclo de Vida para el ecodiseño del sistema Intemper TF de cubierta ecológica aljibe

The construction industry is one of the less sustainable activities on the planet: with a consumption of 40% of the materials entering the global economy and the generation of 40–50% of the global output of greenhouse gases. The biggest environmental impact caused by buildings is generated during their use phase due to the energy consumption for thermal conditioning. Addition of green elements to buildings is used to improve energy efficiency of buildings. In this study Life Cycle Assessment (LCA) methodology has been applied to quantify the environmental impact of the green roofs materials to analyze its environmental profile. The identification of hot spots of the system permits an ecodesign strategy that effectively reduces environmental burdens associated with roof construction, optimizing the environmental performance. The results identify the high environmental impact associated to the structure, the important contribution of the felt wick irrigation system and the extruded polystyrene thermal insulation.El sector de la construcción representa una de las actividades menos sostenibles del planeta: consume el 40% de los materiales de la economía global y genera el 40-50% de las emisiones de gases de efecto invernadero. El mayor impacto ambiental de los edificios se genera durante su fase de uso, debido al gasto energético de su acondicionamiento térmico. El uso de elementos vegetales es una de las estrategias empleadas para aumentar la eficiencia energética. En este trabajo se ha empleado la metodología de Análisis de Ciclo de Vida (ACV) para cuantificar el impacto ambiental de los materiales de la cubierta vegetal. Se han identificado los puntos críticos del sistema para establecer una estrategia de ecodiseño y reducir eficazmente las cargas ambientales. Los resultados obtenidos muestran la importancia del impacto ambiental del soporte estructural, la elevada contribución de la mecha de riego de fieltro y del aislamiento de poliestireno extrudido

Phase diagram of silicon from atomistic simulations

In this letter we present a calculation of the temperature-pressure phase diagram of Si in a range of pressures covering from -5 to 20 GPa and temperatures up to the melting point. The phase boundaries and triple points between the diamond, liquid, $\beta$-Sn and ${Si}_{34}$ clathrate phases are reported. We have employed efficient simulation techniques to calculate free energies and to numerically integrate the Clausius-Clapeyron equation, combined with a tight binding model capable of an accuracy comparable to that of first-principles methods. The resulting phase diagram agrees well with the available experimental data.Comment: 5 pages, 1 figure, accepted in PR

In-situ monitoring by thermal lens microscopy of a photocatalytic reduction process of hexavalent chromium

In this work, we describe the application of a micro-spatial thermal lens spectroscopy setup (thermal lens microscope, TLM) with coaxial counter-propagating pump, and probe laser beams, and an integrated passive optical Fabry-Perot, to quantify the Cr-VI concentration in water during a photocatalytic reaction in-situ. A series of test samples was analyzed using the 1.5 diphenil carbazide colorimetric method. A calibration curve was obtained by plotting of the TLM signal as a function of the concentration of Cr(VI) in a range between 0 and 10 mu g/L (1 mu g/L = 1 ppb, part per billion), with a detection limit of 53 ng/L (1 ng/L = 1 ppt, part per trillion). A solution of 10 mu g/L Cr(VI) in distillated water was placed into a cell in contact with an iron-incorporated titanium dioxide film, which was previously grown onto a 1 mm thick glass microscope slide by the sol-gel dip-coating technique. The TLM signal was registered as a function of the photocatalysis time measured from the beginning of the process, radiating the film with UV-violet light. The Cr(VI) concentration was determined with the calibration curve and after the first 50 minutes a reduction of 95 % of Cr(VI) was observed, being the chemical reaction kinetic described by a potential time decreasing function.645507511Agências de fomento estrangeiras apoiaram essa pesquisa, mais informações acesse artig

Análisis de la frecuencia cardiaca en el entrenamiento de gimnastas de tumbling

En el presente estudio se analiza la frecuencia cardiaca (Fc) durante el entrenamiento de gimnastas de tumbling de nivel nacional e internacional, al objeto de obtener información acerca de cómo discurre a lo largo del mismo y extrapolarlo a la planificación de los volúmenes y las intensidades de los entrenamientos. Para ello se han analizado los registros de la Fc de 8 gimnastas de edades comprendidas entre 18 y 23 años mediante la colocación de un pulsómetro Polar Sport Tester

Correlated-informed neural networks: a new machine learning framework to predict pressure drop in micro-channels

Accurate pressure drop estimation in forced boiling phenomena is important during the thermal analysis and the geometric design of cryogenic heat exchangers. However, current methods to predict the pressure drop have one of two problems: lack of accuracy or generalization to different situations. In this work, we present the correlated-informed neural networks (CoINN), a new paradigm in applying the artificial neural network (ANN) technique combined with a successful pressure drop correlation as a mapping tool to predict the pressure drop of zeotropic mixtures in micro-channels. The proposed approach is inspired by Transfer Learning, highly used in deep learning problems with reduced datasets. Our method improves the ANN performance by transferring the knowledge of the Sun & Mishima correlation for the pressure drop to the ANN. The correlation having physical and phenomenological implications for the pressure drop in micro-channels considerably improves the performance and generalization capabilities of the ANN. The final architecture consists of three inputs: the mixture vapor quality, the micro-channel inner diameter, and the available pressure drop correlation. The results show the benefits gained using the correlated-informed approach predicting experimental data used for training and a posterior test with a mean relative error (mre) of 6%, lower than the Sun & Mishima correlation of 13%. Additionally, this approach can be extended to other mixtures and experimental settings, a missing feature in other approaches for mapping correlations using ANNs for heat transfer applications

Analyzing the turbulent planetary boundary layer by remote sensing systems: the Doppler wind lidar, aerosol elastic lidar and microwave radiometer

he planetary boundary layer (PBL) is the lowermost region of troposphere and is endowed with turbulent characteristics, which can have mechanical and/or thermodynamic origins. This behavior gives this layer great importance, mainly in studies about pollutant dispersion and weather forecasting. However, the instruments usually applied in studies of turbulence in the PBL have limitations in spatial resolution (anemometer towers) or temporal resolution (instrumentation aboard an aircraft). Ground-based remote sensing, both active and passive, offers an alternative for studying the PBL. In this study we show the capabilities of combining different remote sensing systems (microwave radiometer – MWR, Doppler lidar – DL – and elastic lidar – EL) for retrieving a detailed picture on the PBL turbulent features. The statistical moments of the high frequency distributions of the vertical wind velocity, derived from DL, and of the backscattered coefficient, derived from EL, are corrected by two methodologies, namely first lag correction and -2=3 law correction. The corrected profiles, obtained from DL data, present small differences when compared with the uncorrected profiles, showing the low influence of noise and the viability of the proposed methodology. Concerning EL, in addition to analyzing the influence of noise, we explore the use of different wavelengths that usually include EL systems operated in extended networks, like the European Aerosol Research Lidar Network (EARLINET),This work was supported by the Andalusia Regional Government through project P12-RNM-2409 and by the Spanish Agencia Estatal de Investigación (AEI) through projects CGL2016-81092-R and CGL2017-90884-REDT. We acknowledge the financial support by the European Union’s Horizon 2020 research and innovation program through project ACTRIS-2 (grant agreement no. 654109)

Algebra of Lax Connection for T-Dual Models

We study relation between T-duality and integrability. We develop the Hamiltonian formalism for principal chiral model on general group manifold and on its T-dual image. We calculate the Poisson bracket of Lax connections in T-dual model and we show that they are non-local as opposite to the Poisson brackets of Lax connection in original model. We demonstrate these calculations on two specific examples: Sigma model on S(2) and sigma model on AdS(2).Comment: 24 pages, references adde

Ciclo de vida, hábitos y morfometría de Metamasius hemipterus olivier y Rhynchophorus palmarum L. (Coleoptera: Curculionidae) en caña de azúcar (Saccharum officinarum L.).

Palma-Elaeis guineensi

La girolline, nouvelle substance antitumorale extraite de l'éponge, Pseudaxinyssa cantharella n. sp. (Axinellidae)

Une nouvelle substance antitumorale a été isolée d'une Eponge néo-calédonienne, #Pseudaxinyssa cantharella$. Sa structure a été établie à l'aide de ses caractéristiques spectrales et par préparation de dérivés sélectivement substitués. (Résumé d'auteur