Novel application for exergy and thermoeconomic analysis of processes simulated with Aspen Plus

A visual basic application for Microsoft® Excel 2007 has been developed as a helpful tool to perform mass, energy, exergy and thermoeconomic (MHBT) calculations during the systematic analysis of energy processes simulated with Aspen Plus®. The application reads an Excel workbook containing three sheets with the matter, work and heat streams results of an Aspen Plus® simulation. The required information from the Aspen Plus® simulation and the algorithm/calculations of the application are described and applied to an Air Separation Unit (ASU). This application helps the designer when MHBT analyses are performed, as it increases the knowledge of the process simulated with Aspen Plus®. It’s a valuable tool not only because of the calculations performed, but also because it creates a new Excel workbook where the results and the formulae written on the cells are fully visible and editable. There is free access to the application and it has no protection allowing changes and improvements to be done

Short-term effects of impurities in the CO2 stream injected into fractured carbonates.

After the Paris Agreement in which 195 countries are involved, the Carbon Capture and Storage (CCS) is now an accepted technology in the United Nations Framework Convention on Climate Change (UNFCCC). In Spain, Fundación Ciudad de la Energía (CIUDEN) has successfully completed the full CCS chain, being CO2 captured in the Technology Development Centre in Cubillos del Sil (León, Spain) whereas that it is geologically stored in a deep saline aquifer, formed by fractured carbonates with poor matrix porosity, located in the Technology Development Plant (TDP) at Hontomín (Burgos, Spain). The results of the field tests, in which up to 150 tons of CO2 and synthetic air (5 %v of N2 and O2) were co-injected on site, are analyzed in this paper comparing the operational parameters gained during the injection of impure CO2 (pressures, temperatures and flow ranges) with its corresponding baseline previously determined (i.e. 1,500 tons of pure CO2 were injected during the reservoir hydraulic characterization). Besides that, the geochemical reactivity analysis of impure CO2 injected in this saline aquifer and its correlation with the results from laboratory tests were assessed. As main conclusions from laboratory scale results, a porosity diminution was measured after the injection of CO2 with 5 %v of SO2; apart from that, without SO2, the effluent pH was in the range of 7-8 whereas in case of CO2 and SO2, a pH of 1-2 was obtained. Otherwise and focused on field scale tests, a density decrease was detected comparing the base case (pure CO2) with the CO2 injection containing 5.1 %v of synthetic air. On the other hand, Ca2+, SO42-, Mg2+ and K+ migration effects in the rock were also detected and analyzed

Composición corporal y condición física de escolares colombianos de educación secundaria y media de Ibagué

Introduction: Body composition and other components of physical fitness have proved to be important markers of health condition.Objective: To analyze body composition and physical fitness in Colombian students from public high schools of Ibagué, as well as to study differences between sexes and age groups, and establish correlations between some of the variables.Materials and methods: The sample consisted of 1,253 students (601 males; 652 females), with an age range of 10-20 years. The ALPHA-Fitness test (extended version) was applied. Body Mass Index (BMI), waist circumference and fat percentage were assessed.Results: Differences between sexes were found in the variables studied, with greater BMI and fat percentage among females (20.6 kg/m2 vs. 19.4 kg/m2 and 26.1% vs. 16.8%, respectively); however, waist circumference was greater in males (69.6 cm vs. 67.9 cm), who also showed better fitness in the rest of the physical tests (p<0.05). In both sexes, age was associated to increases in BMI (p<0.05), and among females to fat percentage as well (p<0.05); among males it was the opposite, as in them, age was inversely associated to fat percentage (p<0.05). For the rest of the physical tests, age was positively associated to fitness both in men and women, except for maximal oxygen uptake (VO2 max). Correlations were found between some of the variables studied.Conclusions: Adiposity was significantly greater in females than in males (p<0.05). Males showed better levels of aerobic, musculoskeletal and motor capacities.Introducción. La composición corporal y otros componentes de la condición física han demostrado ser importantes indicadores de la condición de salud.Objetivo. Analizar la composición corporal y la condición física de escolares colombianos de educación secundaria y media de las instituciones oficiales de Ibagué, estudiar las diferencias por sexo y edad, y establecer la correlación entre algunas variables.Materiales y métodos. Participaron 1.253 estudiantes (601 hombres y 652 mujeres), con un rango de edad entre los 10 y los 20 años. Se aplicaron las pruebas físicas de la batería ALPHA-Fitness en su versión extendida. Se evaluó el índice de masa corporal (IMC), el perímetro de la cintura y el porcentaje de grasa.Resultados. Se encontraron diferencias por sexo en las variables estudiadas, con mayor IMC y porcentaje de grasa en las mujeres que en los hombres (20,6 Vs. 19,4 kg/m2 y 26,1 Vs. 16,8 %, respectivamente); sin embargo, el perímetro de cintura fue mayor en los hombres (69,6 cm Vs. 67,9 cm), aunque ellos registraron mejor rendimiento en el resto de pruebas físicas (p<0,05). En ambos sexos la edad se asoció con aumentos del IMC (p<0,05) y, en las mujeres, con el porcentaje de grasa (p<0,05), lo que no ocurrió en los hombres, en quienes la edad se asoció inversamente con la grasa corporal (p<0,05). En el resto de las pruebas físicas, la edad se asoció positivamente con el rendimiento en ambos sexos, excepto en el consumo máximo de oxígeno (VO2 máx). Se hallaron correlaciones entre algunas de las variables estudiadas.Conclusiones. La adiposidad fue significativamente mayor en las mujeres que en los hombres (p<0,05). Los hombres tuvieron mejores niveles de capacidad aeróbica, musculoesquelética y motora

Multifunctional Nanocarriers Based on Chitosan Oligomers and Graphitic Carbon Nitride Assembly

In this study, a graphitic carbon nitride and chitosan oligomers (g-C3N4–COS) nanocarrier assembly, which was obtained by cross-linking with methacrylic anhydride (MA), was synthesized and characterized. Its characterization was carried out using infrared spectroscopy, elemental and thermal analyses, and transmission electron microscopy. The new nanocarriers (NCs), with an average particle size of 85 nm in diameter and a 0.25 dispersity index, showed photocatalytic activity (associated with the g-C3N4 moiety), susceptibility to enzymatic degradation (due to the presence of the COS moiety), and high encapsulation and moderate-high release efficiencies (>95% and >74%, respectively). As a proof of concept, the visible-light-driven photocatalytic activity of the NCs was tested for rhodamine B degradation and the reduction of uranium(VI) to uranium(IV). Regarding the potential of the nanocarriers for the encapsulation and delivery of bioactive products for crop protection, NCs loaded with Rubia tinctorum extracts were investigated in vitro against three Vitis vinifera phytopathogens (viz. Neofusicoccum parvum, Diplodia seriata, and Xylophilus ampelinus), obtaining minimum inhibitory concentration values of 750, 250, and 187.5 µg·mL−1, respectively. Their antifungal activity was further tested in vivo as a pruning wound protection product in young ‘Tempranillo’ grapevine plants that were artificially infected with the two aforementioned species of the family Botryosphaeriaceae, finding a significant reduction of the necrosis lengths in the inner woody tissues. Therefore, g-C3N4-MA-COS NCs may be put forward as a multifunctional platform for environmental and agrochemical delivery applications

Experiencia de mentorización entre docentes universitarios

Los profesores universitarios son los únicos profesionales de la educación reglada, en España, que no reciben una formación específica para el desarrollo de su actividad. La implantación de programas y planes de asesoramiento y mentoría para profesores noveles ofrece una excelente oportunidad para iniciarse en el ejercicio de la docencia universitaria. Este tipo de programas reduce incertidumbres y favorece el logro de los niveles de calidad y excelencia que ha de exigirse en la enseñanza universitaria. En esta comunicación se explica una experiencia de asesoría a profesores noveles desarrollada en la Facultad de Ciencias Políticas de la Universidad de Granada durante el curso 2009-2010

Prototipo de pulsera para la medida de ECG bajo demanda y la medida continua de la onda de pulso

El interés en la variabilidad de ritmo cardiaco (HRV) y la estimación de la presión arterial a partir del tiempo de llegada de la onda de pulso (PAT) se ha incrementado exponencialmente en los últimos años debido a los indicadores que se pueden extraer. En este trabajo se presenta un prototipo de pulsera que, sin ningún otro medio externo a esta, es capaz de medir electrocardiograma (ECG), onda de pulso y, por consiguiente el PAT, de forma no invasiva. Además, está diseñada para la realización de medidas oportunistas y pensando en la comodidad del usuario. Se presentan también los materiales y electrónica empleados para la implementación del prototipo. A partir de los resultados obtenidos se da una guía para la colocación de los sensores en la pulsera. Finalmente, los resultados indican que la calidad de las medidas realizadas es suficiente para ser utilizadas en el estudio de HRV y PAT.Postprint (updated version

Anorexia nerviosa. Una causa excepcional de derrame pericárdico severo

It is well known that eating disorders causes malnutrition and have devastating effects on cardiovascular, endocrine, digestive and neurological system. This case is about a patient with anorexia nervosa that belongs to the 22% of patients that, due to hipoproteinemia, develop pericardial effusion. Even if it is large, according to its aetiology, the patient has bradycardia and none signs of hemodynamic instability. Finally, thanks to a weight gain, it decreases significantly and the patient is discharged. Se conoce que los trastornos de la conducta alimentaria restrictivos suponen un déficit de nutrientes que tiene consecuencias fatales en el sistema cardiovascular, endocrino, digestivo y neurológico. El caso que se expone forma parte de ese 22% de pacientes con anorexia nerviosa que, debido a la hipoproteinemia desarrollan un derrame pericárdico. La particularidad del caso reside en que, a pesar de la severidad del derrame, este no presenta ningún signo de taponamiento, al contrario y de acuerdo con la etiología del mismo, el paciente se encuentra bradicárdico. Además, con la ganancia ponderal a lo largo de su ingreso se logra una mejoría del mismo

LCC Resonant Multilevel Converter for X-ray Applications

Medical X-ray appliances use high-voltage power supplies that must be able to work with very different energy requirements. Two techniques can be distinguished in X-ray medical imaging: fluoroscopy and radioscopy. The former involves low power radiation with a long exposure time, while radioscopy requires large power during short radiographic exposure times. Since the converter has to be designed by taking into account the maximum power specification, it will exhibit a poor efficiency when operating at low power levels. Such a problem can be solved by using a new multilevel LCC topology. This topology is based on a classical series-parallel resonant topology, but includes an additional low-voltage auxiliary transformer whose function depends on the X-ray technique considered. When radioscopy operation is selected, the transformer will allow the power to be shared between two full-bridges. If fluoroscopy mode is activated, the auxiliary full bridge is disconnected and the magnetizing inductance of the auxiliary transformer is used to increase the resonant inductor in order to reduce the resonant currents, thus improving the efficiency of the converte

Modeling a multilevel converter for radiography and fluoroscopy

EPE'16 ECCE Europe, 18th European Conference on Power Electronics and Applications, 5-9 september 2016, Karsruhe, GermanyIn this paper a mathematical model for a resonant multilevel converter is presented. The topology has been conceived to be used in X-ray power supplies. The power stage has been designed to minimize the resonant current throughout the input voltage range: 400V to 750V. The inverter stage is based on the series-parallel resonant topology, LCC, to include the parasitic elements of the step-up transformer. However, the introduction of an additional magnetic coupling provides a way to modify the reactive elements depending on the output powe