Prediction of Heat Transfer and Fluid Flow Effects on Entropy Generation in a Monolithic Catalytic Converter Using Large-Eddy Simulation

In the present work, heat transfer and fluid flow and their effects on entropy generation in a realistic catalytic converter of a Lada Niva 21214 vehicle are studied using large eddy simulation. At first, the pressure drop over the catalytic converter is measured for dry air at constant temperature (T=298 K), different volumetric flow rates, and extrapolated to large volumetric flow rates for dry air (T=298 K) and for the exhaust gas under realistic engine conditions (T=900 K) using the Darcy–Forchheimer relation. Then, coupled heat and fluid flow phenomena inside the catalytic converter are analyzed for nonreacting isothermal conditions and nonreacting conditions with conjugate heat transfer by using the large-eddy simulation. The predicted pressure drop agrees well with the measured and extrapolated data. Based on the obtained numerical results, the characteristic flow features are identified, namely: the impinging flow with stagnation, recirculation, flow separation and laminarization within the fine ducts of the monolith, which depends on the heat transfer through temperature-dependent thermophysical properties of exhaust gas. Moreover, due to high-velocity gradients at the wall of the narrow ducts in the monolith, entropy production by viscous dissipation is observed predominantly in the monolith region. In contrast, entropy production due to heat transport is relatively small in the monolith region, while it overwhelms viscous dissipation effects in the pipe regions

Prediction of Heat Transfer and Fluid Flow Effects on Entropy Generation in a Monolithic Catalytic Converter Using Large-Eddy Simulation

In the present work, heat transfer and fluid flow and their effects on entropy generation in a realistic catalytic converter of a Lada Niva 21214 vehicle are studied using large eddy simulation. At first, the pressure drop over the catalytic converter is measured for dry air at constant temperature (T=298 K), different volumetric flow rates, and extrapolated to large volumetric flow rates for dry air (T=298 K) and for the exhaust gas under realistic engine conditions (T=900 K) using the Darcy–Forchheimer relation. Then, coupled heat and fluid flow phenomena inside the catalytic converter are analyzed for nonreacting isothermal conditions and nonreacting conditions with conjugate heat transfer by using the large-eddy simulation. The predicted pressure drop agrees well with the measured and extrapolated data. Based on the obtained numerical results, the characteristic flow features are identified, namely: the impinging flow with stagnation, recirculation, flow separation and laminarization within the fine ducts of the monolith, which depends on the heat transfer through temperature-dependent thermophysical properties of exhaust gas. Moreover, due to high-velocity gradients at the wall of the narrow ducts in the monolith, entropy production by viscous dissipation is observed predominantly in the monolith region. In contrast, entropy production due to heat transport is relatively small in the monolith region, while it overwhelms viscous dissipation effects in the pipe regions

Memorias: primer encuentro de la RED internacional de investigación en el marco de la X Jornada de Investigación 2019

ERII 2019 es el Primer Encuentro de la Red Internacional Universitaria para el Desarrollo de la Investigación y las Publicaciones Científicas, conformada por la Universidad Católica de Colombia, la Universidad Católica de Salta (Argentina), la Universidad de Monterrey (México) y la Universidad Gabriela Mistral (Chile). Esta red tiene como principal objetivo potenciar el desarrollo de la actividad investigativa, mediante la formalización de redes de investigadores, la promoción de actividades conjuntas, el diseño de planes y movilidad y el trabajo en una red editorial. La actividad académica fue un espacio abierto para compartir experiencias y resultados de investigación no solo de las universidades adscritas a la red, sino de otras instituciones que participaron en el evento. (Tomado de la fuente).1ra ediciónIntroducción ponencias I. Derecho y Ciencias Sociales Análisis del marco institucional vinculado a la implementación de las salvaguardas REDD+ en la Provincia de Salta, Argentina Guadalupe Zapata: intersticios en la construcción histórica fundacional de Pereira, Colombia La notificación por aviso como garantía al debido proceso y tutela judicial efectiva en el proceso monitorio colombiano: análisis en el marco de la Sentencia C-031/2019 Migración y prácticas territoriales de la comunidad boliviana en la ciudad de Salta, Argentina El derecho de infancia y adolescencia en Colombia: reflexiones sobre su estatuto jurídico-doctrinal La soberanía funcional en Colombia para los derechos humanos Agnición de los militares víctimas del conflicto armado en Colombia Elementos politológicos y jurídicos del voto en blanco, el voto nulo y el abstencionismo en las elecciones presidenciales de Ecuador 2017, Costa Rica 2018 y Colombia 2018 La democracia: ¿un fruto envenenado? Una propuesta de jerarquización de las democracias liberales Estudio sobre las relaciones de similitud, causalidad y simbólicas en niños de 3 a 13 años Garantías para el ejercicio de los derechos de los usuarios y estudiantes con discapacidad, enfocado en la inclusión desde el consultorio jurídico de CECAR II. Arte, Arquitectura, Urbanismo y Diseño La industrialización como motor de suburbanización y metropolización de Monterrey, México, en el siglo XX Reivindicación del campesinado desde sus prácticas y saberes: tradiciones en tiempos del posacuerdo en el Sumapaz (Colombia) Diseño geométrico de “calado” para potencializar la ventilación natural en edificaciones El Anfiteatro de la quebrada de Las Conchas: caracterización acústica direccional Estrategia de intervención urbana para la reconfiguración de las redes caminables del borde urbano. Caso de estudio: Sierra Morena, USME Instrumentos musicales del Caribe colombiano en vías de extinción: guandú, arco de boca y marimba de pierna Dispositivos de cambio: intervenciones colectivas en el borde urbano suroriental de Bogotá Creación de nuevos procesos y diseños para la arquitectura de América Latina con la ayuda de indicadores III. Ingeniería y Tecnología Diseño de inclusión tecnológica educativa a través del B-Learning y las TIC Diseño de soluciones tecnológicas a problemas del contexto local en región a través del semillero de investigación TECSIS de la Universidad de Caldas Aplicación de las tecnologías semánticas a la forensia digital: ontología del correo electrónico y su trazabilidad para el análisis forense M-Learning aplicado para estudio de mercados en la formulación de proyectos Análisis en la generación de caudales pico a partir del cambio de la cobertura vegetal en la cuenca Sardinata, departamento del Norte de Santander, Colombia Análisis de impactos ambientales provocados por el aprovechamiento de recursos naturales renovables: metodologías que desarrollan nuevas fuentes generadoras de energía en Panamá y Colombia Aplicación de un modelo unificado para arcillas y arenas a suelos típicos de la ciudad de Salta Estudio técnico para la planeación de la emisora radial de la Universidad Católica de Colombia con migración hacia radio digital La transferencia de las tecnologías limpias en la vivienda social en Brasil y Colombia Desarrollo de un contador Geiger-Müller para verificar la exposición a la radiación en salas de radiología convencional Diseño de un controlador tolerante a fallas en un vehículo de suspensión semiactiva IV. Ciencias de la Salud Biorremediación de residuos peligrosos generados por laboratorios de docencia de la Universidad Colegio Mayor de Cundinamarca Morbilidad en Ecuador, 2007-2016 El desplazamiento del metabolismo de atorvastatina es afectado por los polimorfismos SLCO1B1 y ABCB1 en la población mexicana Terapia ocupacional basada en la evidencia y razonamiento profesional en equipos interdisciplinares de tecnología de apoyo: prótesis impresas en 3D de la Corporación Fabrilab Vicisitudes actuales de la autoridad en las familias de Salta, Argentina Efecto de la lesión por leishmaniasis cutánea (Leishmania braziliensis, Leishmania amazonensis) en el nervio periférico y dermis en ratones Balb/C. Estudio in vivo Diseño y validación del cuestionario de gravedad social percibida del consumo de alcohol en adolescentes Diseño y construcción de una aplicación virtual para rehabilitación auditiva en adultos Revisión sistemática: propiedades psicométricas de los instrumentos utilizados para evaluar las actividades instrumentales de la vida diaria en joven, adulto y persona mayor V. Negocios, Ciencias Económicas y Administrativas Estudio de factibilidad para la conformación de una empresa prestadora de servicios para motocicletas en Manizales Oferta productiva del cacao colombiano en el posconflicto: estrategias para el aprovechamiento de oportunidades comerciales en el marco del acuerdo comercial entre Colombia y la Unión Europea VI. Educación y Humanidades La infantilización del estudiante universitario: origen, situación actual e implicaciones Promoción de competencias socioafectivas en el aula Análisis de la estructura curricular de la Licenciatura en Higiene y Seguridad en el Trabajo: el sistema modular La familia cristiana, una nueva buena para el tercer milenio: los Encuentros Mundiales de las Familias, de Juan Pablo II a Francisco (1994-2018) Perspectivas de la innovación educativa que caracterizan los trabajos de investigación de la Maestría en E-Learning de la Universidad Autónoma de Bucaramanga (Colombia) Análisis de las nuevas tendencias laborales y formativas del trabajador social de Uniminuto (Girardot) Articulación entre la educación religiosa escolar y el derecho a la libertad religiosa Análisis correlacional del aporte de la educación pregradual a la educación secundaria de los egresados del programa de Trabajo Social del 2018 del CRG Uniminuto El aprendizaje en la resignificación de la vida de las infancias Modelo teórico predictor de la retención estudiantil a partir del engagement en la Fundación Universitaria Los Libertadores La letra con sangre entra: castigo permitido en la educación escolar en Bogotá La diferencia en la educación pósteres I. Arte, Arquitectura, Urbanismo y Diseño Restructuración de los paisajes naturales presentes en los bordes urbanos de Bogotá ¿Paisaje, medioambiente y tecnología como bioarquitectura del paisaje? El equipamiento de culto en la construcción del borde urbano de la ciudad II. Ingeniería y Tecnología Nueva matriz para registrar la experiencia consolidada de los oferentes que contratan con el Estado en el sector de la infraestructura vial, en la empresa JOYCO S. A. S Seguridad a un ojo de distancia Sistema de radio sobre fibra para la transmisión de imágenes Estructuras en guadua (quiosco) y bambú (yurta)* Análisis de la utilización de fibras de guadua como refuerzo del concreto Laboratorios con simulación y con equipo real en la enseñanza de redes de computadoras en el nivel universitario Análisis bibliométrico de la correlación existente entre los tópicos de “identificadores de radiofrecuencia” y “gestión de cadena de suministros” como caso de estudio II. Ciencias de la Salud Presencia en manos y conocimiento de Staphylococcus aureus coagulasa positivo en estudiantes de áreas de la salud IV. Educación y Humanidades Del refugio de la virtualidad a la exposición del contacto real Conclusione

Antimicrobial Lessons From a Large Observational Cohort on Intra-abdominal Infections in Intensive Care Units

evere intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by disease-specific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed.Severe intra-abdominal infection commonly requires intensive care. Mortality is high and is mainly determined by diseasespecific characteristics, i.e. setting of infection onset, anatomical barrier disruption, and severity of disease expression. Recent observations revealed that antimicrobial resistance appears equally common in community-acquired and late-onset hospital-acquired infection. This challenges basic principles in anti-infective therapy guidelines, including the paradigm that pathogens involved in community-acquired infection are covered by standard empiric antimicrobial regimens, and second, the concept of nosocomial acquisition as the main driver for resistance involvement. In this study, we report on resistance profiles of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecalis and Enterococcus faecium in distinct European geographic regions based on an observational cohort study on intra-abdominal infections in intensive care unit (ICU) patients. Resistance against aminopenicillins, fluoroquinolones, and third-generation cephalosporins in E. coli, K. pneumoniae and P. aeruginosa is problematic, as is carbapenem-resistance in the latter pathogen. For E. coli and K. pneumoniae, resistance is mainly an issue in Central Europe, Eastern and South-East Europe, and Southern Europe, while resistance in P. aeruginosa is additionally problematic in Western Europe. Vancomycin-resistance in E. faecalis is of lesser concern but requires vigilance in E. faecium in Central and Eastern and South-East Europe. In the subcohort of patients with secondary peritonitis presenting with either sepsis or septic shock, the appropriateness of empiric antimicrobial therapy was not associated with mortality. In contrast, failure of source control was strongly associated with mortality. The relevance of these new insights for future recommendations regarding empiric antimicrobial therapy in intra-abdominal infections is discussed

Poor timing and failure of source control are risk factors for mortality in critically ill patients with secondary peritonitis

Purpose: To describe data on epidemiology, microbiology, clinical characteristics and outcome of adult patients admitted in the intensive care unit (ICU) with secondary peritonitis, with special emphasis on antimicrobial therapy and source control. Methods: Post hoc analysis of a multicenter observational study (Abdominal Sepsis Study, AbSeS) including 2621 adult ICU patients with intra-abdominal infection in 306 ICUs from 42 countries. Time-till-source control intervention was calculated as from time of diagnosis and classified into 'emergency' (< 2 h), 'urgent' (2-6 h), and 'delayed' (> 6 h). Relationships were assessed by logistic regression analysis and reported as odds ratios (OR) and 95% confidence interval (CI). Results: The cohort included 1077 cases of microbiologically confirmed secondary peritonitis. Mortality was 29.7%. The rate of appropriate empiric therapy showed no difference between survivors and non-survivors (66.4% vs. 61.3%, p = 0.1). A stepwise increase in mortality was observed with increasing Sequential Organ Failure Assessment (SOFA) scores (19.6% for a value ≤ 4-55.4% for a value > 12, p < 0.001). The highest odds of death were associated with septic shock (OR 3.08 [1.42-7.00]), late-onset hospital-acquired peritonitis (OR 1.71 [1.16-2.52]) and failed source control evidenced by persistent inflammation at day 7 (OR 5.71 [3.99-8.18]). Compared with 'emergency' source control intervention (< 2 h of diagnosis), 'urgent' source control was the only modifiable covariate associated with lower odds of mortality (OR 0.50 [0.34-0.73]). Conclusion: 'Urgent' and successful source control was associated with improved odds of survival. Appropriateness of empirical antimicrobial treatment did not significantly affect survival suggesting that source control is more determinative for outcome

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials Group Project

PURPOSE: To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). METHODS: We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. RESULTS: The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. CONCLUSION: This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection.status: publishe

Epidemiology of intra-abdominal infection and sepsis in critically ill patients: "AbSeS", a multinational observational cohort study and ESICM Trials Group Project

Purpose To describe the epidemiology of intra-abdominal infection in an international cohort of ICU patients according to a new system that classifies cases according to setting of infection acquisition (community-acquired, early onset hospital-acquired, and late-onset hospital-acquired), anatomical disruption (absent or present with localized or diffuse peritonitis), and severity of disease expression (infection, sepsis, and septic shock). Methods We performed a multicenter (n = 309), observational, epidemiological study including adult ICU patients diagnosed with intra-abdominal infection. Risk factors for mortality were assessed by logistic regression analysis. Results The cohort included 2621 patients. Setting of infection acquisition was community-acquired in 31.6%, early onset hospital-acquired in 25%, and late-onset hospital-acquired in 43.4% of patients. Overall prevalence of antimicrobial resistance was 26.3% and difficult-to-treat resistant Gram-negative bacteria 4.3%, with great variation according to geographic region. No difference in prevalence of antimicrobial resistance was observed according to setting of infection acquisition. Overall mortality was 29.1%. Independent risk factors for mortality included late-onset hospital-acquired infection, diffuse peritonitis, sepsis, septic shock, older age, malnutrition, liver failure, congestive heart failure, antimicrobial resistance (either methicillin-resistant Staphylococcus aureus, vancomycin-resistant enterococci, extended-spectrum beta-lactamase-producing Gram-negative bacteria, or carbapenem-resistant Gram-negative bacteria) and source control failure evidenced by either the need for surgical revision or persistent inflammation. Conclusion This multinational, heterogeneous cohort of ICU patients with intra-abdominal infection revealed that setting of infection acquisition, anatomical disruption, and severity of disease expression are disease-specific phenotypic characteristics associated with outcome, irrespective of the type of infection. Antimicrobial resistance is equally common in community-acquired as in hospital-acquired infection