Diseño de silo experimental para el estudio de sistemas de protección frente a las explosiones de polvo

El objetivo principal de este trabajo es el diseño de un silo experimental concebido para el ensayo de explosiones de polvo venteadas. Este equipo permitirá avanzar en el conocimiento de todas las variables que intervienen en el fenómeno de la explosión y del venteo; y también avanzar en el diseño de dispositivos de protección más eficaces. Gracias a su diseño modular se pretende disponer de una herramienta abierta a multitud de posibilidades de ensayo, pudiendo variar factores con gran influencia en el desarrollo de la explosión, como el área de venteo, el volumen del silo y su relación altura/diámetro (L/D)

Dust explosions in vented silos: Simulations and comparisons with current standards

[EN] Dust explosions represent a serious hazard to personnel and equipment in industries and silo facilities that handle combustible materials. Venting devices are the most common protective systems employed in silos, although their use may pose problems in large and low-strength silos. The main aim of the present work was to simulate dust explosions in silos using a commercial CFD program, the DESC code, to determine the pressures developed in vented explosions with vent areas of different sizes. Dust cloud characteristics were taken fromstudies carried out by the FSA(ResearchCentre for Applied System Safety andIndustrial Medicine, Germany) in a 12 m3silo with a mechanical feeding system. The pressures and associated vent areas in these simulations were compared to those contemplated in two venting standards. The simulated explosion pressures showed the expected trends for the associated vent areas and agreed reasonably well with the values contemplated in NFPA 68(2007) [5]. However,whenthe reduced explosion overpressure waslow, the vent area contemplated in EN 14491 (2006) [4] was much larger than in the present simulations.SIThe authors express their deepest gratitude to the late Dr.Frank Hauert (FSA) for providing information on the CREDIT Project. Acknowledgements are also due to the Education Council of the Community of Castilla y León (Spain) and the European Social Fund, for funding this work via project LE010B05 and via a research gran

Ignition and explosion characteristics of olive-derived biomasses

Pore size distributions and degree of anisotropy (pore channel orientation) affect the mechanical properties, fragmentation, and dissolution kinetics of granular composites. Especially in porous solids such as granular urea fertilizers, uncontrolled dissolution leads to soil and water contamination from nutrient leaching. In this work, a dry compaction method and a bilayer granulation process were compared to investigate their ability to control the nutrient release from granular urea fertilizers. Urea and binary mixtures of urea and a xanthan and konjac gum binder were dry compacted. The compacts were then milled to specific particle sizes producing core granules. The core granules were drum granulated along with a known percent of fines and water to produce bilayer granules. The drum granulation parameters were optimized based on the granules’ particle size distri- butions and color analysis. Dissolution and porosity distributions of core and bilayer granules were investigated and compared to market urea granules. Core granules with or without a binder compacted at 100 MPa had smaller pore size distributions compared with core granules compacted at 50 MPa, bilayer granules, and market urea granules. Core granules compacted at 100 MPa showed a significant decrease in the dissolution rate compared to less dense systems, such as core granules at 50 MPa, bilayer, and market urea granules. The addition of gums as binder caused an additional delay in the dissolution rate, indicating that formulation design is essential in controlling nutrient release. Less porous structures, i.e., higher compaction pressure to produce core granules, along with binder addition resulted in delayed dissolution rates due to binder migration and gelation atS

Treatment with tocilizumab or corticosteroids for COVID-19 patients with hyperinflammatory state: a multicentre cohort study (SAM-COVID-19)

Objectives: The objective of this study was to estimate the association between tocilizumab or corticosteroids and the risk of intubation or death in patients with coronavirus disease 19 (COVID-19) with a hyperinflammatory state according to clinical and laboratory parameters. Methods: A cohort study was performed in 60 Spanish hospitals including 778 patients with COVID-19 and clinical and laboratory data indicative of a hyperinflammatory state. Treatment was mainly with tocilizumab, an intermediate-high dose of corticosteroids (IHDC), a pulse dose of corticosteroids (PDC), combination therapy, or no treatment. Primary outcome was intubation or death; follow-up was 21 days. Propensity score-adjusted estimations using Cox regression (logistic regression if needed) were calculated. Propensity scores were used as confounders, matching variables and for the inverse probability of treatment weights (IPTWs). Results: In all, 88, 117, 78 and 151 patients treated with tocilizumab, IHDC, PDC, and combination therapy, respectively, were compared with 344 untreated patients. The primary endpoint occurred in 10 (11.4%), 27 (23.1%), 12 (15.4%), 40 (25.6%) and 69 (21.1%), respectively. The IPTW-based hazard ratios (odds ratio for combination therapy) for the primary endpoint were 0.32 (95%CI 0.22-0.47; p < 0.001) for tocilizumab, 0.82 (0.71-1.30; p 0.82) for IHDC, 0.61 (0.43-0.86; p 0.006) for PDC, and 1.17 (0.86-1.58; p 0.30) for combination therapy. Other applications of the propensity score provided similar results, but were not significant for PDC. Tocilizumab was also associated with lower hazard of death alone in IPTW analysis (0.07; 0.02-0.17; p < 0.001). Conclusions: Tocilizumab might be useful in COVID-19 patients with a hyperinflammatory state and should be prioritized for randomized trials in this situatio

Las medidas de aseguramiento para imputables en la nueva legislación penal colombiana

T345.0527 G984m151 páginas: ilustracione

Auditoria a la eficiencia energética de la caldera jct200-h3p del tunel de tratamiento de cataforesis en la empresa Sofasa de Envigado.

La eficiencia energética es un aspecto crucial en la actualidad para la competitividad de cualquier tipo de empresa, incluyendo en este concepto de eficiencia los diferentes aspectos energéticos: consumo eléctrico, de combustibles fósiles (provenientes del petróleo, carbón o gas natural) y otras fuentes de energía alternativas. Para SOFASA es una realidad que golpea fuerte a su puerta y para algunos de sus funcionarios se presenta como una oportunidad en el campo laboral y académico, es a partir de allí que nuestro equipo decide realizar esta auditoria al equipo de calentamiento de agua Caldera JCT del TTS de pintura con la premisa de inspeccionar la eficiencia energética de la caldera, durante la lectura del documento se vera como se fue recopilando paso a paso todos los datos estadísticos de funcionamiento de la caldera tales como: consumo de combustible, caudal de agua, temperaturas de entrada y salida del agua, temperaturas de entrada y salida de los gases factor de aireación y precio del combustible. Una ves que se obtuvo todos estos datos se procede a tabularlos y reemplazarlos en las formulas de calculo que ya existen para hallar la eficiencia del equipo, una vez determinada la eficiencia ya sea por método directo o indirecto se procede a comparar estos datos y analizarlos para proceder a formular las recomendaciones a la empresa, una ves realizada las recomendaciones se pretende que surja un plan de acción convalidado por el auditor y los responsables de las acciones, es entonces el plan de acción el objetivo final que toda auditoria debe alcanzar pues con ello asegura que la gestión de la auditoria no se quede en simples informes archivados sin ningún valor para la empresa. Un buen plan de acción podrá ayudar a toda empresa a mantener sus niveles de contaminación bajos, mantenimiento, productividad y calidad muy altos.Introducción. -- 1. Planteamiento del problema. -- 2. Justificación del problema. -- 3. Objetivos. -- 3.1 Objetivo general. -- 3.2 Objetivos específicos. -- 4. Marco teórico. -- 4.1 Reseña histórica de sofasa. -- 4.2 Definición auditoría energética. -- 4.2.1 Diagnostico. -- 4.2.2 Implementación y seguimiento. -- 4.3 Que es una caldera de vapor. -- 4.4 Definición de balance de energía. -- 4.5. Definición de eficiencia térmica. -- 5. Descripción del proceso. -- 6. Metodología. -- 7. Auditoria energética de la caldera jct 200 h3p. -- 7.2. Eficiencia de la caldera. -- 8. Análisis de los datos. -- 9. Recomendaciones. -- 10. Recursos. -- 11 Conclusiones. -- 12. Bibliografía. -- 12. Anexos. -

FACTORES CRITICOS DE EXITO, BALANCED SCORECARD

Articulo de investigación Maestría en Finanzas. Facultad de Ciencias Económicas y AdministrativasEn Colombia, las mipymes desempeñan un papel significativo en la economía del país, debido a su gran influencia en la generación de empleo. Por esta razón, es fundamental que estas empresas cuenten con una sólida planificación estratégica para administrar eficazmente sus actividades administrativas e impulsar su crecimiento. Por tanto, uno de los mayores desafíos que enfrentan son los limitados recursos planeación estratégica con los que cuentan y que pueden utilizarse para medir e impulsar sus objetivos organizacionales. Debido a esto se realiza una investigación que permite proponer unos indicadores como una herramienta de medición y control. Por ello, se propone un modelo de gestión basado en el Balanced Scorecard (BSC), la cual es una herramienta útil para la planeación estratégica que considera las cuatro perspectivas: financiera, cliente, procesos internos, aprendizaje y desarrollo. Teniendo como base los factores críticos de éxito se realizan cinco entrevistas semiestructuradas con ejecutivos de una mipyme del sector de la construcción, analizando las respuestas por medio del software Atlas. Ti. Los análisis realizados con el software sirvieron como base para la formulación de los indicadores para el área de presupuesto y finanzas y área de operaciones, que les sirva a las mipymes como herramienta analítica para la toma de decisiones y evaluación continua de los resultados y diseñar estrategias para lograr una alternativa al problema planteado.In Colombia, MSMEs play a significant role in the country's economy due to their great influence on job creation, with the construction sector being one of the sectors that contributes the most in this regard. For this reason, these companies must have solid strategic planning to manage their administrative activities effectively and drive their growth. Therefore, one of the biggest challenges they face is their limited strategic planning resources, which can be used to measure and drive their organizational objectives. Due to this, research is carried out that allows us to propose indicators as a measurement and control tool. Therefore, a management model based on the Balanced Scorecard (BSC), a useful tool for strategic planning that considers the four perspectives: financial, customer, internal processes, learning, and development, is proposed. Using the critical success factors as a conceptual basis, five semi-structured interviews were carried out with executives of an MSME in the construction sector, and the responses were analyzed using Atlas. Ti software. The analyses carried out with the software served as a basis for formulating indicators for the budget finance and operations areas. These serve the MSMEs as an analytical tool for decision-making, continuous evaluation of results, and designing strategies to achieve an alternative to the problem posed.MaestríaMagister en Finanza

Chiral ligand-exchange chromatography with Cinchona alkaloids. Exploring experimental conditions for enantioseparation of α-amino acids

The natural Cinchona alkaloid quinidine as chiral selector in chiral ligand-exchange chromatography was systematically studied. Chromatographic conditions for enantioseparation of twentya-amino acidswere first timestudied by changing mobile phase parameters such as pH, concentration of organic solvent, type of salt, ligand to metal ratio and also column temperature. Maximum retention and enantioselectivity factors were observed at the region close to pH = 8, since the tertiary amine (the quinuclidinic nitrogen) of the quinidine is protonated only in a small degree, and therefore is available for the chelate formation. Additionally at this pH value there is no other competing ligand for complex the metallic cation. The thermodynamic transfer parameters of the enantiomers from the mobile to the stationary phase from van't Hoff plots within the range of 10-35 °C were estimated. Thus, the differences in the transfer enthalpy Δ(ΔH), and transfer entropy Δ(ΔS) enabled an investigation of the origin of the differences in interaction energies Δ(ΔG). Finally, the molecular geometry of the formed diastereomeric complexes was modelled and energetic differences between both compounds were calculated by a semi empirical method.Fil: Echevarria, Romina Noel. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Franca, Carlos Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Química Inorgánica "Dr. Pedro J. Aymonino". Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Centro de Química Inorgánica "Dr. Pedro J. Aymonino"; ArgentinaFil: Tascon, Marcos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Castells, Cecilia Beatriz Marta. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; ArgentinaFil: Keunchkarian, Sonia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Exactas; Argentin

Análisis y arquitectura del sistema de CDT para el Banco de Occidente

T005.12 M566a v.1145 p