Fortran para localizar todos los azeótropos homogéneos de ocho mezclas quinarias

La capacidad de predecir si una determinada mezcla multicomponente formará uno o más azeótropos y el determinar las condiciones de presión o temperatura junto con la composición de cada azeótropo que se forma, son esenciales para diseñar la estrategia para llevar a cabo la separación de cada uno de los componentes. Análogamente, es necesario tomar en cuenta el efecto de la temperatura y la presión sobre la composición del azeótropo en el diseño de procesos de separación. En este trabajo se determinó los azeótropos binarios, ternarios, cuaternarios y quinarios de ocho mezclas con cinco componentes cada una a presión atmosférica. La desviación de los resultados al comparar la mezcla multicomponente acetona, cloroformo, metanol, etanol y benceno con valores de los puntos azeotrópicos reportados en la literatura fue de 6.4% en composición y 1.1 % en temperatura utilizando el modelo de solución de la fase líquida de Wilson.The ability to predict if a given multicomponent mixture will form one or more azeotropes and to obtain the pressure or temperature and the composition of each azeotrope that is formed, are essential to design the strategy to carry out the separation of each component. Another hand it is necessary to take into account the effect of temperature and pressure on the composition of the azeotrope in the design of processes separation. In this work were determined binary, ternary, quaternary and quinary azeotropes from eight mixtures of five components at atmospheric pressure. The deviation obtained in the mixture acetone, chloroform, methanol, ethanol and benzene with reported values in literature was 6.4% and 1.1 % in composition in temperature respectively with the Wilson model

Simulación del proceso de separación de acroleína presente en una mezcla multicomponente vía Aspen Plus

Actualmente, en la industria química se presentan diferentes problemas de separación de mezclas multicomponentes, los métodos comúnmente empleados son destilación, absorción, extracción líquido-líquido, etc. El presente trabajo se centra en la destilación, ya que la destilación es el proceso más empleado para la separación de mezclas, el predominio de la destilación sobre otras operaciones unitarias de separación de mezclas obedece fundamentalmente a que se trata de la operación que permite la mayor velocidad de transferencia de masa. El objetivo de este trabajo es realizar el diseño del proceso de separación de la acroleína de una mezcla multicomponente, que permita obtener una pureza de acroleína mayor al 90% mol y llevar a cabo la simulación del proceso de separación con el simulador comercial Aspen Plus. La acroleína se separa de la mezcla multicomponente Agua-Acroleína-Hidroxiacetona-Acetaldehído-Formaldehído que se obtiene a partir de la deshidratación del glicerol.Now, in the chemical industry exist different difficulties of separation of multicomponent mixtures, the process commonly used are distillation, absorption, liquid-liquid extraction, etc. The present work regard on distillation, since the distillation is the most used process for the separation of mixtures, the acceptance of distillation over other unit operations of mixtures separation, submits to the greater speed of mass transfer. The focus of this work is to design the separation process of acrolein from a multicomponent mixture with a purity greater than 90% mol and develop the simulation of process separation by a commercial simulator Aspen Plus. The acrolein is separated from the multicomponent mixture Water-Acrolein- Hydroxyacetone-Acetaldehyde- Formaldehyde which is obtained from the dehydration of glycerol

Preparación de un material híbrido adsorbente

El objetivo de esta investigación es desarrollar un material híbrido para ser usado, en un futuro, como adsorbente y/o catalizador de compuestos orgánicos volátiles (COV´s), dicho material está conformado por una zeolita natural, que es un sustrato de estructura cristalina cuyas propiedades son ampliamente utilizadas en el tratamiento de COV’s y, por otra parte, por una estructura metal orgánica (MOF) compuesta de cerio, que también es sabido tiene excelentes propiedades como adsorbente; se busca lograr un efecto sinérgico entre ambos materiales, y que el material híbrido así conformado funcione primeramente como adsorbente y además como un catalizador con propiedades redox, que permita la oxidación de los COV´s en sustancias no tóxicas. Por lo que en esta propuesta se propone preparar un material híbrido eficiente y de bajo costo a partir el uso de una MOF con Ce y una zeolita natural, para una completa y efectiva oxidación de COV´s.The objective of this research is to develop a hybrid material to be used, in the future, as an adsorbent and/or catalyst of volatile organic compounds (VOC’s), said material is formed by a natural zeolite, which is a substrate of crystalline structure whose properties are widely used in the treatment of VOC’s and, on the other hand, by an organic metal structure (MOF) composed of cerium, which is also known to have excellent adsorbent properties. We want to achieve a synergistic effect between both materials, and that the hybrid material thus formed functions primarily as an adsorbent and also as a catalyst with redox properties, which allows the oxidation of VOC’s into non-toxic substances. So in this proposal it is proposed to prepare an efficient and low-cost hybrid material from the use of a MOF with Ce and a natural zeolite, for a complete and effective oxidation of VOC’s

The impact of surgical delay on resectability of colorectal cancer: An international prospective cohort study

AimThe SARS-CoV-2 pandemic has provided a unique opportunity to explore the impact of surgical delays on cancer resectability. This study aimed to compare resectability for colorectal cancer patients undergoing delayed versus non-delayed surgery.MethodsThis was an international prospective cohort study of consecutive colorectal cancer patients with a decision for curative surgery (January-April 2020). Surgical delay was defined as an operation taking place more than 4 weeks after treatment decision, in a patient who did not receive neoadjuvant therapy. A subgroup analysis explored the effects of delay in elective patients only. The impact of longer delays was explored in a sensitivity analysis. The primary outcome was complete resection, defined as curative resection with an R0 margin.ResultsOverall, 5453 patients from 304 hospitals in 47 countries were included, of whom 6.6% (358/5453) did not receive their planned operation. Of the 4304 operated patients without neoadjuvant therapy, 40.5% (1744/4304) were delayed beyond 4 weeks. Delayed patients were more likely to be older, men, more comorbid, have higher body mass index and have rectal cancer and early stage disease. Delayed patients had higher unadjusted rates of complete resection (93.7% vs. 91.9%, P = 0.032) and lower rates of emergency surgery (4.5% vs. 22.5%, P ConclusionOne in 15 colorectal cancer patients did not receive their planned operation during the first wave of COVID-19. Surgical delay did not appear to compromise resectability, raising the hypothesis that any reduction in long-term survival attributable to delays is likely to be due to micro-metastatic disease

Delaying surgery for patients with a previous SARS-CoV-2 infection

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