Activity of alumina supported fe catalysts for N2O decomposition: Effects of the iron content and thermal treatment

Indexación: Scopus.The activity of Fe2O3/Al2O3 catalysts prepared by impregnation of Al2O3 with different amounts of Fe and calcination temperatures (650 and 900 °C) in the direct N2O decomposition reaction was studied. High calcination temperature was introduced to study the effect of "aging", which are the conditions prevailing in the process-gas option for N2O abatement. The catalysts were characterized by BET, XRD, UV-DRS, and H2-TPR. The incorporation of Fe promotes the alumina phase transition (g-Al2O3 to a-Al2O3) when the catalysts are calcined at 900 °C, which is accompanied by a decrease in the specifc area. The activity of the catalysts and the specifc surface area depend on Fe loading and calcination temperature. It was found that highly dispersed Fe species are more active than bulk type Fe2O3 particles. We conclude that Fe2O3/Al2O3 catalysts prepared by impregnation method are active in the decomposition of N2O, to be used at low or high reaction temperatures (tail-gas or process-gas treatments, respectively), as part of nitric acid production plant. © 2018 Sociedad Chilena de Quimica. All rights reserved.https://scielo.conicyt.cl/pdf/jcchems/v62n4/0717-9324-jcchems-62-04-3752.pd

Digital Competences in the Profile of Teaching Education: Context of Remote Education of Peru

Education developed in the virtual context becomes remote today both because of the distance in which school groups are served far from the city, as well as the distance that teachers and students have to reach technological resources to educate and educate themselves, and the resources that affect a higher quality digital education.In this sense, it is understood that digital skills are essential to generate relevant, comprehensive, inclusive and cooperative virtual educational methodologies, especially during the pandemic, which requires mastery of teaching techniques and mastery of these digital skills. The objective was to determine the causality of digital competencies on the teacher teaching profile. The methodology developed was quantitative, causal, correlational and transactional. The sample consisted of 200 active teachers in Basic Education from a Latin American city. These developed their teaching during the onset of the pandemic (2020) until the middle of the year 2021. The variables were evaluated with Likert-type scales. The reports conclude that the scores in digital competencies present moderate intensity of causality and correlation on the teaching profile of those evaluated. Similar effects were found from digital skills on the cognitive and affective characteristics of the profile, although there are common causal effects on motivation. It is suggested to include other variables in a multi-causal analysis, considering vulnerable contexts in evaluating teachers and their execution during the pandemic

Amplification of cestode DNA from the peri-anal region of naturally infected foxes by PCR and LAMP: proof of concept for a potential sampling strategy for diagnosing human taeniosis

The diagnosis of human taeniosis can be achieved through coproscopy, ELISA or PCR. An important limitation of these methods is the high turnaround time for stool sample collection and preparation, indicating the need for a straightforward sampling strategy. Due to the high metabolic activity and reproductive potential of Taenia spp., we hypothesise that parasite DNA (cells and eggs) present in the peri-anal region of the host can be exploited as a target for molecular diagnosis. We evaluated the feasibility of recovering parasite DNA from the peri-anal area of foxes naturally infected with Taenia spp. Before necropsy, cotton swabs were rubbed at the peri-anal region of foxes. DNA was extracted using alkaline lysis coupled with a commercial DNA isolation kit (method A) or alkaline lysis alone (method B). DNA was used in the multiplex-PCR assay (previously described and called here swab-PCR) and a novel LAMP assay detecting Taenia spp. commonly found in foxes (swab-LAMP). The results of these assays from 105 foxes were compared with the presence of intestinal helminths determined at necropsy and by the sedimentation and counting technique (SCT). The sensitivity of swab-PCR for detecting Taenia (n = 68) was 89.8% (95% CI, 77.7–96.6) and 89.5% (66.9–98.7) using methods A and B, respectively. The sensitivity of the swab-LAMP assay was 83.7% (70.3–92.7) using method A and 89.5% (66.9–98.7) with method B. We postulate that peri-anal swab sampling followed by simplified DNA extraction and LAMP might be a suitable strategy for surveillance of human taeniosis in resource-limited settings in the future

The nature of leisure revisited : an interpretation of digital leisure

Information and communication technologies have made it possible to engage in leisure and paid-work activities outside their usual context, thereby challenging the construction of their meanings. We explored 30 individuals' narratives in an endeavour to identify the properties of digital leisure and paid-work activities performed in and out of their usual contexts. Our interpretation suggests that the nature of leisure activities is only associated with the freedom of individuals to choose which activity to do and how to do it. The patterns of interpenetration, integration, and segmentation of spaces varied according to informants occupations, but were also moderated by marital status and gender. We conclude with a discussion of how these find¬ings challenge the traditional divisions between work and leisure

Bochdalek hernia associated with intestinal malrotation as an incidental finding in an adult patient: case report

Bochdalek hernia (BH) is the most common congenital diaphragmatic hernia, however in adults the clinical presentation and diagnosis is rare. Intestinal malrotation (IM) is a congenital anomaly that results in an alteration in intestinal anatomy secondary to inadequate intestinal rotation, which occurs at the end of the first trimester of embryonic development, some digestive anomalies may be related, such as diaphragmatic hernia, its Diagnosis is made in the neonatal period although it can be diagnosed in older children and adults, debuting with symptoms of intestinal obstruction or being an incidental finding. Below we present a case report of an adult patient with a diagnosis of Bochdalek congenital diaphragmatic hernia (CDH) in whom an incidental diagnosis of IM was made, who underwent elective surgery, performing laparoscopic diaphragmatic plasty with favorable results

Cornea Confocal Microscopy: Utilities and Perspectives

The cornea is the ocular refractive medium with the greatest refractive power of the eye. The study of it is of vital importance for the diagnosis and follow-up of ophthalmological diseases with the aim of achieving high standards of visual acuity in our patients. Confocal microscopy of the cornea allows in-depth study of it, quickly, safely, painlessly, obtaining high-resolution images of the corneal sublayers. This chapter summarizes the procedure for performing corneal confocal microscopy, the normal characteristics of the tissue with real images of our patients, as well as a brief explanation of the main applications of this technology in the study of corneal dystrophies (keratoconus), in refractive surgery, corneal transplantation, infectious keratitis, glaucoma filtration bulla, among other topics

Distribuição exata da estatistica de razão de verossimilhança para testar Ho: =I em populações normais multivariadas complexas

Orientador: Pushpa Narayan RathieDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Matematica, Estatistica e Ciencia da ComputaçãoResumo: O objetivo do presente trabalho é a determinação da distribuição exata do critério de razão de verossimilhança para testar a hipótese Ho : S = I contra H1 : S ? I em populações normais multivariadas complexas. A distribuição da estatística de razão de verossimilhança determina-se em forma de série de densidade chi-quadrado, série logarítmica e série beta incompleta. Faz-se cálculo computacional para determinar os valores de À correspondente a níveis de a = 0.01,0.05,0.10,0.90,0.95 e 0.99 para 2,3 e 4 variáveis e vários tamanhos de amostras, especificamente para amostras pequenas.Abstract: Not informedMestradoMestre em Estatístic

Clasificación de leucocitos en imágenes microscópicas de frotis sanguíneo usando machine learning y CNN

El problema principal de las formas actuales de realizar la clasificación de leucocitos es que solo tenemos dos opciones más comunes en el mercado, se utiliza una maquinaria de alto coste para poder hacer el procedimiento de clasificación o un técnico de laboratorio lo tiene que hacer manualmente con una muestra y un microscopio. El objetivó de esta investigación es poder validar un tercer camino el cual utiliza tecnologías que tuvieron un gran avance recientemente en el mercado como lo son machine learning (más específicamente las Redes Neuronales Convolucionales) para la creación de nuevas soluciones con Inteligencia Artificial. Con este objetivo en mente se siguieron varios pasos. El primero es la identificación del grado de error de los procesos manuales y automatizados. Para este objetivo, se realiza un análisis bibliográfico y se determinó que el promedio de grado de error de los procesos manuales y automatizados son de 18.33 % y 3.59 % respectivamente. Y para la investigación se decidió utilizar un grado de error mínimo de 5 %. La solución que cumplió con este valor seleccionado tiene garantizado ser una solución mejor que el procedimiento manual y ser comparable con procedimientos automatizados realizados por maquinaria especializada. Para la obtención del dataset, el cual fue utilizado en los procesos de entrenamiento validación y testeo de los modelos de redes neuronales, se decidió utilizar datos de investigaciones previas realizadas por entidades de diferentes partes del mundo y publicados para su uso en investigación. Se utilizaron 4 fuentes de datos los cuales nos dieron un dataset diverso de 37760 muestras. Como el dataset obtenido tenía una deficiencia de pocas muestras de un tipo especifico de leucocitos. Se decidió utilizar la técnica de preprocesamiento de datos llamada Data Augmentation; el cual, usando variaciones de rotación, flip, iluminación (valor gamma) y ruido gaussiano permitió aumentar el número de muestras a 59877. Se procedió a realizar iteraciones para la detección de la estructura del modelo de red neuronal convolucional. Durante estas iteraciones se decidió utilizar técnicas contra el overfitting (el cual es uno de los principales problemas que pueden presentar las redes neuronales). Las técnicas las cuales se utilizaron fueron reducción de complejidad de la estructura de modelo, valores de regularización y capas de DropOut (capas que eliminan aleatoriamente entradas de una capa oculta de la red neuronal). Todas estas técnicas se vieron efectivas ya que con su ayuda se logró determinar un modelo el cual cumplía con nuestro grado de error mínimo. El ultimo paso fue un proceso de testeo, en este paso se realizaron las pruebas de predicción de uno a uno, uso de la función de evaluación propio de la framework de keras, generación de 129 dataset de 500 imágenes cada uno para prode verificar resultado obtenido con la función de evaluación previamente utilizado y generación de matriz de confusión para poder ver diferentes resultados de predicción