CFD model-based analysis and experimental assessment of key design parameters for an integrated unglazed metallic thermal collector façade

Active façade systems incorporating solar thermal collectors currently offer very promising energetic solutions. From among the available systems, a simple solution is the unglazed heat collector for potential integration in low-temperature applications. However, when adopting system definitions, the modification of some design parameters and their impact has to be fully understood. In this study, the case of an unglazed collector integrated into a sandwich panel is assessed and a specific analysis is performed for a proper assessment of the influence of key design parameters. Based on that case study of the real built system, a CFD model is developed and validated and a parametric assessment is then performed, by altering the configurations of both the panel and the hydraulic circuit. In this way, the potential of each measure to harness solar energy can be evaluated and each parameter with its different level of impact can be highlighted, to identify those of higher relevance. A characterization of the real solution completes the study, by providing the efficiency curves and the total energy collected during the experimental campaign. The maximum estimate of the efficiency of a 6 m2 façade was within a range between 0.47 and 0.34 and the heat loss factor was between 4.8 and 7.5. The case study exercises reveal the real energy efficiency and solar production patterns. There was also an opportunity to consider significant improvements to increase the output of the active façade. The main conclusions concerned the different criteria that improved the definition of the system and greater comprehension of alternative designs that may be integrated in the underlying concept.The authors are grateful to the Basque Government for fundingthis research through projects IT781-13 and IT1314-19 and to allthose involved in the different stages for their guidance andinvaluable help.The authors would also like to thank all those companies andresearchers participating in the BASSE project for their stronginvolvement during that research. Results from BASSE project haveinspired present research. The BASSE project received funding fromthe European Union, RFCS Program, Research Fund for Coal and Steel project Building Active Steel Skin (BASSE, Grant Agreement noRFSR-CT-2013-00026

Kinetic Modeling of the UV/H2O2 Process: Determining the Effective Hydroxyl Radical Concentration

A kinetic model for pollutant degradation by the UV/H2O2 system was developed. The model includes the background matrix effect, the reaction intermediate action, and the pH change during time. It was validated for water containing phenol and three different ways of calculating HO° level time-evolution were assumed (non-pseudo-steady, pseudo-steady and simplified pseudo-steady state; denoted as kinetic models A, B and C, respectively). It was found that the kind of assumption considered was not significant for phenol degradation. On the other hand, taking into account the high levels of HO2° formed in the reaction solution compared to HO° concentration (~10–7 M >>>> ~10–14 M), HO2° action in transforming phenol was considered. For this purpose, phenol-HO2° reaction rate constant was calculated and estimated to be 1.6x103 M-1 s-1, resulting in the range of data reported from literature. It was observed that, although including HO2° action allowed slightly improving the kinetic model degree of fit, HO° developed the major role in phenol conversion, due to their high oxidation potential. In this sense, an effective level of HO° can be determined in order to be maintained throughout the UV/H2O2 system reaction time for achieving an efficient pollutant degradation

Sensitive spectrophotometric determination of hydrogen peroxide in aqueous samples from advanced oxidation processes: Evaluation of possible interferences

Hydrogen peroxide (H2O2) determination in real watersamples was carried out in a simple and sensitiveway. The resulting optimal operating conditions froma 23 full factorial experimental design were 450 nm, 50mm and 6x10-3 M for the absorption wavelength, thequartz cell path length and the final concentration ofthe ammonium monovanadate solution, respectively;allowing the quantification of H2O2 up to 2.94x10-3mM. The proposed analytical method was validatedand the effect of the background matrix was investigated,obtaining a selective method. Additionally, thedeveloped analytical method was applied for studyingthe evolution of H2O2 in the decontamination of watercontaining 6.73x10-5 mM of anthracene and 1.19x10-5mM of benzo[a]pyrene using the UV/H2O2 system. Itwas found that the optimal H2O2 level enabling about45% of mineralisation and a removal of the targetpolycyclic aromatic hydrocarbons higher than 99%was 2.94x10-1 mM, remaining approximately 1.47x10-1 mM of H2O2 after 90 min of treatment

Iterative approach to computational enzyme design

A general approach for the computational design of enzymes to catalyze arbitrary reactions is a goal at the forefront of the field of protein design. Recently, computationally designed enzymes have been produced for three chemical reactions through the synthesis and screening of a large number of variants. Here, we present an iterative approach that has led to the development of the most catalytically efficient computationally designed enzyme for the Kemp elimination to date. Previously established computational techniques were used to generate an initial design, HG-1, which was catalytically inactive. Analysis of HG-1 with molecular dynamics simulations (MD) and X-ray crystallography indicated that the inactivity might be due to bound waters and high flexibility of residues within the active site. This analysis guided changes to our design procedure, moved the design deeper into the interior of the protein, and resulted in an active Kemp eliminase, HG-2. The cocrystal structure of this enzyme with a transition state analog (TSA) revealed that the TSA was bound in the active site, interacted with the intended catalytic base in a catalytically relevant manner, but was flipped relative to the design model. MD analysis of HG-2 led to an additional point mutation, HG-3, that produced a further threefold improvement in activity. This iterative approach to computational enzyme design, including detailed MD and structural analysis of both active and inactive designs, promises a more complete understanding of the underlying principles of enzymatic catalysis and furthers progress toward reliably producing active enzymes

La formación de valores en la historia de la educación colombiana

El presente artículo esta orientado describir el pasado, el presente y las tendencias de la formación de valores en la educación superior colombiana. Inicialmente se hace un recuento histórico de las diferentes épocas de la educación colombiana, la cual estuvo influenciada desde sus comienzos por la religión católica tendencia que permaneció incólume desde la colonia hasta finales de 1970. Posteriormente y en especial en las postrimerías del siglo XX, se presentaron varios acontecimientos que incidieron para que el objetivo de formar valores fuera perdiendo importancia hasta quedar totalmente relegado, estos sucesos fueron : a) el vertiginoso avance científico y técnico que se presentó después de los años setenta incidiendo para que nuestros directivos encargados de orientar la políticas de la educación superior terminaran privilegiando, la instrucción sobre la educación y b) los fenómenos de narcotráfico, guerrilla y corrupción que han venido recorriendo nefastamente, el territorio nacional transformaron el tejido axiológico sobre el cual se cimentaba la sociedad colombiana. Por fortuna con el advenimiento del siglo XXI, la formación en: ética, moral y valores se ha convertido en una recomendación universal emanada desde la UNESCO. En los foros y congresos sobre educación e los ámbitos: internacional, nacional, regional y locales, el tema de formación en valores ha saltado a la palestra y se ha convertido en una tendencia de primera línea. En este sentido, la educación superior colombiana deberá hacer un gran esfuerzo en los próximos años para recuperar la formación integral de estudiante colombiano, deberá por tanto diseñar políticas, establecer programas y trazar tareas que permitan recuperar la urdimbre axiológica, visión explicitada en la parte final de este artículo para que en nuestras facultades y carreras se introduzcan mecanismos que permitan formar ciudadanos integrales esto es: instruidos y éticos

Why simheuristics? : Benefits, limitations, and best practices when combining metaheuristics with simulation

Many decision-making processes in our society involve NP-hard optimization problems. The largescale, dynamism, and uncertainty of these problems constrain the potential use of stand-alone optimization methods. The same applies for isolated simulation models, which do not have the potential to find optimal solutions in a combinatorial environment. This paper discusses the utilization of modelling and solving approaches based on the integration of simulation with metaheuristics. These 'simheuristic' algorithms, which constitute a natural extension of both metaheuristics and simulation techniques, should be used as a 'first-resort' method when addressing large-scale and NP-hard optimization problems under uncertainty -which is a frequent case in real-life applications. We outline the benefits and limitations of simheuristic algorithms, provide numerical experiments that validate our arguments, review some recent publications, and outline the best practices to consider during their design and implementation stages

Increasing knowledge of the transmissivity field of a detrital aquifer by geostatistical merging of different sources of information

Acknowledgements The work reported here was supported by research project PID2019-106435GB-I00 of the Ministerio de Ciencia e Innovación of Spain. We thank Philippe Renard and the two anonymous reviewers who provided constructive comments that have allowed us to improve the final version of this paper.Transmissivity is a significant hydrogeological parameter that affects the reliability of groundwater flow and transport models. This study demonstrates the improvement in the estimated transmissivity field of an unconfined detritic aquifer that can be obtained by using geostatistical methods to combine three types of data: hard transmissivity data obtained from pumping tests, soft transmissivity data obtained from lithological information from boreholes, and water head data. The piezometric data can be related to transmissivity by solving the hydrogeology inverse problem, i.e., including the observed water head to determine the unknown model parameters (log transmissivities). The geostatistical combination of all the available information is achieved by using three different geostatistical methodologies: ordinary kriging, ordinary co-kriging and inverse problem universal co-kriging. In addition, there are eight methodological cases to be compared according to which log-transmissivity data are considered as the primary variable in co-kriging and whether two or three variables are used in inverse-problem universal co-kriging. The results are validated by using the performance statistics of the direct modelling of the unconfined groundwater flow and comparing observed water heads with the modelled ones. Although the results show that the two sets of log-transmissivity data are incompatible, the set of log-transmissivity data from the lithofacies provides a good log-transmissivity image that can be improved by inverse modelling. The map provided by inverse-problem universal co-kriging provides the best results. Using three variables, rather than two in the inverse problem, gives worse results because of the incompatibility of the log-transmissivity data sets.Project PID2019-106435GB-I00 of the Ministerio de Ciencia e Innovación of SpainOpen Access funding provided thanks to the CRUE-CSIC agreement with Springer Natur

Acinetobacter Lwofii, an unusual cause of infectious pericarditis complicated with cardiac tamponade: a case report

Bacterial pericarditis can be considered a rare pathology, usually associated with cardiac procedures and, to a lesser extent, with immunosuppression and chronic diseases. The importance of its knowledge lies in the fact that mortality can reach up to 100% in untreated patients. Once diagnosed, pericardiocentesis and administration of intravenous antimicrobial therapy are mandatory for the prevention of its complications, which include cardiac tamponade and sepsis. Here we present an exceptional case of infectious pericarditis due to Acinetobacter Lwoffii in an older adult, which was complicated by pericardial effusion and cardiac tamponade

Determinación espectrofotométrica sensible del peróxido de hidrógeno en muestras de agua procedentes de procesos de oxidación avanzada : Evaluación de posibles interferencias

RESUMEN: La determinación de peróxido de hidrógeno (H2O2) en muestras de agua real se llevó a cabo de una manera sencilla y sensible. Las condiciones óptimas de funcionamiento resultantes de un diseño experimental factorial completo fueron 450 nm, 50 mm y 6 x 10-3 M de longitud de onda de absorción, longitud de trayectoria de la celda de cuarzo y concentración final de la solución de monovanadato de amonio, respectivamente; permitiendo la cuantificación de 2.94x10-3 mM de H2O2. Se validó el método analítico propuesto y se investigó el efecto de la matriz obteniendo un método selectivo. Además, se aplicó el método analítico desarrollado para estudiar la evolución de H2O2 en la descontaminación de agua que contenía 6,73x10-5 mM de antraceno y 1,19x10-5 mM de benzo[a]pireno utilizando el sistema UV/H2O2. Se encontró que el nivel óptimo de H2O2 que permitía cerca del 45% de mineralización y una eliminación de los hidrocarburos aromáticos policíclicos objeto de estudio superior al 99% fue de 2,94x10-1 mM, permaneciendo aproximadamente 1,47x10-1 mM de H2O2 después de 90 min de tratamiento.ABSTRACT: Hydrogen peroxide (H2O2) determination in real water samples was carried out in a simple and sensitive way. The resulting optimal operating conditions from a 23 full factorial experimental design were 450 nm, 50 mm and 6x10-3 M for the absorption wavelength, the quartz cell path length and the final concentration of the ammonium monovanadate solution, respectively; allowing the quantification of H2O2 up to 2.94x10-3 mM. The proposed analytical method was validated and the effect of the background matrix was investigated, obtaining a selective method. Additionally, the developed analytical method was applied for studying the evolution of H2O2 in the decontamination of water containing 6.73x10-5 mM of anthracene and 1.19x10-5 mM of benzo[a]pyrene using the UV/H2O2 system. It was found that the optimal H2O2 level enabling about 45% of mineralisation and a removal of the target polycyclic aromatic hydrocarbons higher than 99% was 2.94x10-1 mM, remaining approximately 1.47x10-1 mM of H2O2 after 90 min of treatment