70 research outputs found

    Remoción del colorante azul marino directo sobre borra de café modificada

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    The presence of dyes in water bodies inhibits the penetration of light, affecting the flora and fauna of these ecosystems, which is why, greater efforts are made to eliminate them before being poured. This study allowed the removal of the direct navy-blue dye (DNB), using activated carbon prepared from coffee beans and H3PO4. The experimental methodology began with the preparation of three types of activated carbon by varying the concentration of H3PO4 (20, 40 and 60% m/v). Texture properties were evaluated by adsorption-desorption isotherms with N2 to 77 K, the identification and quantification of organic functional groups, mainly acids, with FTIR and the Boehm method, respectively. Batch adsorption experiments were performed by varying the initial dye concentration (5, 10, 50, 75, 100 and 200 mg/dm3) to 25 °C and, the adsorption kinetics was determined. Both coffee beans and activated carbons have an acidic nature with surface area development between 519 and 771 m2/g. With respect to the batch study, a monolayer and multilayer growth was observed on a heterogeneous surface. Activated carbon prepared with 20% of H3PO4 recorded the highest removal capacity with a value of 25.8 mg/g. The kinetic model of pseudo second order was the one that best fit to the experimental data (R2 > 0.98). It can be concluded that the coffee bean treated with H3PO4 is an efficient adsorbent to remove DNB from aqueous solutions.La presencia de colorantes en los cuerpos de agua inhibe la penetración de la luz, afectando la flora y la fauna de estos ecosistemas, razón por la cual se hacen cada vez esfuerzos mayores para eliminarlos antes de ser vertidos. Este estudio permitió remover el colorante azul marino directo (AMD), empleando carbón activado preparado a partir de la borra de café y H3PO4. La metodología experimental inició con la preparación de tres tipos de carbón activado, variando la concentración de H3PO4 (20, 40 y 60% m/v). Las propiedades de textura se evaluaron mediante isotermas de adsorción-desorción con N2 a 77 K; la identificación y cuantificación de grupos funcionales orgánicos, en especial ácidos, con FTIR, y el método de Boehm, respectivamente. Se realizaron experimentos de adsorción por lote, variando la concentración inicial del colorante (5, 10, 50, 75, 100 y 200 mg/dm3) a 25 °C y se determinó la cinética de adsorción. Tanto la borra de café como los carbones activados tienen naturaleza ácida con desarrollo de áreas superficiales entre 519 y 771 m2/g. Con respecto al estudio por lote, se observó un crecimiento en monocapa y multicapa sobre una superficie heterogénea. El carbón activado preparado con 20% de H3PO4 registró la mayor capacidad de remoción, con un valor de 25.8 mg/g. El modelo cinético de pseudo segundo orden fue el que mejor se ajustó a los datos experimentales (R2 > 0.98). Se puede concluir que la borra de café tratada con H3PO4 es un adsorbente eficiente para eliminar AMD de soluciones acuosas

    The Long-Baseline Neutrino Experiment: Exploring Fundamental Symmetries of the Universe

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    The preponderance of matter over antimatter in the early Universe, the dynamics of the supernova bursts that produced the heavy elements necessary for life and whether protons eventually decay --- these mysteries at the forefront of particle physics and astrophysics are key to understanding the early evolution of our Universe, its current state and its eventual fate. The Long-Baseline Neutrino Experiment (LBNE) represents an extensively developed plan for a world-class experiment dedicated to addressing these questions. LBNE is conceived around three central components: (1) a new, high-intensity neutrino source generated from a megawatt-class proton accelerator at Fermi National Accelerator Laboratory, (2) a near neutrino detector just downstream of the source, and (3) a massive liquid argon time-projection chamber deployed as a far detector deep underground at the Sanford Underground Research Facility. This facility, located at the site of the former Homestake Mine in Lead, South Dakota, is approximately 1,300 km from the neutrino source at Fermilab -- a distance (baseline) that delivers optimal sensitivity to neutrino charge-parity symmetry violation and mass ordering effects. This ambitious yet cost-effective design incorporates scalability and flexibility and can accommodate a variety of upgrades and contributions. With its exceptional combination of experimental configuration, technical capabilities, and potential for transformative discoveries, LBNE promises to be a vital facility for the field of particle physics worldwide, providing physicists from around the globe with opportunities to collaborate in a twenty to thirty year program of exciting science. In this document we provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess.Comment: Major update of previous version. This is the reference document for LBNE science program and current status. Chapters 1, 3, and 9 provide a comprehensive overview of LBNE's scientific objectives, its place in the landscape of neutrino physics worldwide, the technologies it will incorporate and the capabilities it will possess. 288 pages, 116 figure

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

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    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

    Clustering COVID-19 ARDS patients through the first days of ICU admission. An analysis of the CIBERESUCICOVID Cohort

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    Background Acute respiratory distress syndrome (ARDS) can be classified into sub-phenotypes according to different inflammatory/clinical status. Prognostic enrichment was achieved by grouping patients into hypoinflammatory or hyperinflammatory sub-phenotypes, even though the time of analysis may change the classification according to treatment response or disease evolution. We aimed to evaluate when patients can be clustered in more than 1 group, and how they may change the clustering of patients using data of baseline or day 3, and the prognosis of patients according to their evolution by changing or not the cluster.Methods Multicenter, observational prospective, and retrospective study of patients admitted due to ARDS related to COVID-19 infection in Spain. Patients were grouped according to a clustering mixed-type data algorithm (k-prototypes) using continuous and categorical readily available variables at baseline and day 3.Results Of 6205 patients, 3743 (60%) were included in the study. According to silhouette analysis, patients were grouped in two clusters. At baseline, 1402 (37%) patients were included in cluster 1 and 2341(63%) in cluster 2. On day 3, 1557(42%) patients were included in cluster 1 and 2086 (57%) in cluster 2. The patients included in cluster 2 were older and more frequently hypertensive and had a higher prevalence of shock, organ dysfunction, inflammatory biomarkers, and worst respiratory indexes at both time points. The 90-day mortality was higher in cluster 2 at both clustering processes (43.8% [n = 1025] versus 27.3% [n = 383] at baseline, and 49% [n = 1023] versus 20.6% [n = 321] on day 3). Four hundred and fifty-eight (33%) patients clustered in the first group were clustered in the second group on day 3. In contrast, 638 (27%) patients clustered in the second group were clustered in the first group on day 3.Conclusions During the first days, patients can be clustered into two groups and the process of clustering patients may change as they continue to evolve. This means that despite a vast majority of patients remaining in the same cluster, a minority reaching 33% of patients analyzed may be re-categorized into different clusters based on their progress. Such changes can significantly impact their prognosis

    Planeamiento Y Control Estratégico De Operaciones-II153-201702

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    Es un curso de especialidad en la carrera de Ingeniería Industrial EPE de carácter teórico dirigido a los estudiantes del 8° ciclo que busca desarrollar las siguientes competencias:Competencias Generales:- Pensamiento crítico.- Manejo de la información.Planeamiento y Control Estratégico de Operaciones es un curso de especialidad en la carrera de IngenieríaIndustrial de carácter teórico-práctico y dirigido a los estudiantes del sexto ciclo. Busca desarrollar lascompetencias generales de Pensamiento Crítico y Manejo de la Información y la competencia específica ABET:(g.1) Se comunica de manera clara y efectiva utilizando el lenguaje técnico de la empresa.El curso prepara a los estudiantes en el manejo apropiado de las diferentes técnicas para diseñar planearprogramar y controlar las operaciones básicas de los procesos de fabricación de bienes y servicios calculando yoptimizando el uso eficiente de los recursos de una organización bajo condiciones reales y cumpliendo con lasexigencias del mundo actual. Asimismo los estudiantes aprenden a definir estrategias alineadas a los objetivosde largo y corto plazo de la empresa actividad que les permite desempeñarse eficientemente en áreas deOperaciones a lo largo de su carrera profesionalLas operaciones al interior de la empresa se elaboran inicialmente con un plan a largo plazo que debe estar alineado con los objetivos de la empresa. Las decisiones de operaciones giran en torno a la capacidad diseño del producto y procesos. Este curso será importante y útil para tu vida profesional porque aprenderás a establecer programas que satisfagan necesidades de insumos y recursos para las operaciones planifiques el uso de dichos insumos y recursos y finalmente puedas controlar los mismos. Este tipo de decisiones te permitirán actuar como lo hace un Gerente de Operaciones

    Síntesis de puntos cuánticos de CdTe mediante la técnica de ablación láser de sólidos en líquidos

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    En este trabajo se presentan resultados sobre la caracterización de puntos cuánticos (PCs) en un medio líquido (acetona) obtenidos por ablación láser a partir de un blanco de Teluro de Cadmio (CdTe). La ablación de CdTe se llevó a cabo mediante un láser de Nd-YAG con pulsos láser de 30 picosegundos. Con el propósito de variar la concentración en la solución de PCs, se realizaron experimentos a diferentes tiempos de irradiación. Las soluciones coloidales de CdTe fueron caracterizadas por espectroscopía UV-Vis y de fotoluminiscencia. El tamaño y forma de los puntos cuánticos generados se determinaron por microscopía electrónica de transmisión (TEM, HRTEM), de donde se confirmó la obtención de nanoestructuras con geometría esférica con una distribución de tamaños entre 4 y 200 nm, centrado en 6 nm. El espectro de fotoluminiscencia de los puntos cuánticos en solución mostró una banda de emisión centrada en 488 nm cuando se excita con luz ultravioleta de 369 nm. Palabras

    Revista Temas Agrarios Volumen 26; Suplemento 1 de 2021

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    1 Simposio Intenacional y 2 Nacional de Ciencias Agronómicas: El renacer del espacio de discusión científica para el Agro colombiano.</jats:p
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