856 research outputs found

    Evaluación experimental y matemática de modelos de adsorción molecular para contaminantes orgánicos en partículas de TiO2-P25

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    Abstract In this work we evaluated conventional models based on adsorption isotherms of L2 type for organic compounds: DCA, phenol and 4-chlorophenol over TiO2-P25 particles to different operational conditions. The models studied were Langmuir-Hinshelwood, Redlich-Petersen and Toth because these models can be applied as possible equations to improve the description of the reaction rate mechanism based on hydroxyl radical attack, and the degradation using heterogeneous photocatalysis. Finally the models were compared with experimental data for determination of the more appropriate isotherm. L-H model was the more appropriate and the results were high effective in the prediction of experimental data. Resumen Se evaluaron modelos convencionales de adsorción molecular basados en isotermas del tipo L2 para compuestos orgánicos ácido dicloroacético, fenol y 4-clorofenol sobre partículas de TiO2-25 a diferentes condiciones de operación. Los modelos estudiados fueron Langmuir-Hinshelwood, Redlich-Petersen y Toth puesto que estos modelos pueden ser aplicados como posibles ecuaciones para mejorar la descripción de los mecanismos de velocidad de reacción basados en ataque de radicales hidroxilo y degradación usando fotocatálisis heterogénea. Los modelos fueron comparados con datos experimentales para determinar la isoterma más adecuada. El modelo L-H fue el mas apropiado y los resultados fueron de alta efectividad en la predicción de los datos experimentales

    Diagnostic study on shape perception errors within 3D-modeling courses

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    Form has always been a central concern for design -- Several tools and strategies have been developed aiming to support form generation from different perspectives -- And these issues are also a matter of study for design education -- Under this view, it is relevant to explore how technology and new interactions can aid design students to better understand form generation -- The present study, therefore, is centered on the 3D-modeling courses (ID0245-Modelación 3D1 and ID0267- Modelación 3D2) and tools (PTC® Creo 3.0™) provided inside the Product Design Engineering syllabus at EAFIT University -- In the ever changing academic world, new generations of students will be always in need of new methodological approaches from educators, in order to better understand the knowledge they are being given -- Curriculum adaptations will be always necessary to achieve this goal -- Therefore, the scope of the present study aims to set the ground for new teaching strategies around the 3D-modeling courses, based on the most commonly identified errors and difficulties found in 3D-modeling students -- These errors or difficulties might not be isolated factors, only present in the named courses -- They can be intrinsically connected with the acquired skills from other form generation-related courses, such as Drawing and Projects (where physical model are built and techniques are introduced by guidance) -- However, since the project is framed by the mentioned 3D-modeling tools and courses, it is necessary to understand how form is being generated inside 3D digital environments as a starting point for future work -- Nowadays, individual software provide increasing capabilities to help achieving specific modeling tasks -- This segmentation and specialization demands high expertize from users to become accustomed and keep up with the ever demanding industry standards -- Nonetheless, speed and quality cannot be compromised -- Hence, the main target around the study will be design students that take their first steps towards product embodiment -- The project, therefore, aims to understand how students approach styling activities and to report on their most common mistakes -- It is based on how they perceive 2D representations of products and how accurate their 3D-models are, based on selected shape properties -- This will serve as an essential input for new teaching strategies towards students’ self-awareness when performing in 3D form-giving environment

    La realimentación en la enseñanza de lenguas extranjeras: un modelo conceptual desde la participación estudiantil

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    From the constructivist perspective held by the Benemérita Universidad Autónoma de Puebla, feedback is an indispensable element of both the learning and teaching processes. The objective of this work is to design a feedback model in a constructivist context of foreign language teaching based on the student experience. This research is oriented under the considerations of the interpretive paradigm, a qualitative approach and a case study methodology. The focus group technique was established as the main information gathering mechanism. The results allow us to point out that feedback is perceived as a phenomenon mediated by three aspects: the role of the student, the role of the teacher and the feedback process. Categories such as professional idiosyncrasy, the design of the process and the attitudinal posture of the students are discussed in the analysis and considered in the construction of a conceptual model.Desde la mirada constructivista que ostenta la Benemérita Universidad Autónoma de Puebla, la realimentación es un elemento indispensable tanto del proceso de aprendizaje como de enseñanza. El objetivo de este trabajo consiste en diseñar un modelo de realimentación en un contexto constructivista de enseñanza de lenguas extranjeras a partir de la experiencia estudiantil. Esta investigación está orientada bajo las consideraciones del paradigma interpretativo, un enfoque cualitativo y una metodología de estudio de caso. Se estableció la técnica de grupos focales como el principal mecanismo de recolección de información. Los resultados permiten señalar que la realimentación es percibida como un fenómeno mediado por tres ejes: el rol del estudiante, el rol del docente y el proceso de realimentación. Categorías como la idiosincrasia profesional, el diseño del proceso y la postura actitudinal de los estudiantes son discutidas en el análisis y consideradas en la construcción de un modelo conceptual

    “El desarrollo de la inteligencia emocional, a través de cuentos escritos en inglés, en Educación Primaria”

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    A lo largo de la historia hemos visto como la Educación Emocional ha sido apar-tada del aula, y lo que pretendo con este trabajo es dar a entender que hablar de educación es siempre hablar de emociones, ya que son una parte fundamental del ser humano que también debe ser enseñada y practicada, para conseguir el desarrollo integral del niño. Considero, que el desarrollo de la Inteligencia Emocional a través de los cuentos ayuda a los niños a identificar emociones, y generar estrategias de resolución de conflic-tos. Por tanto, esa ha sido la motivación y finalidad de mi trabajo, desarrollar la Inteligen-cia Emocional y la enseñanza- aprendizaje de una Lengua Extranjera (Inglés), a través de una actividad tan dinámica como es la lectura en el aula de Educación Primaria.Throughout history we have seen how the Emotional Education has been away from the classroom, and what I intend with this work is to understand that talking about education is always talking about emotions, because they are an essential part of the hu-man species which must be taught and practiced, to achieve the integral development of the child. I think that the development of the Emotional Intelligence through stories helps children to identify emotions and develop strategies for conflict resolution. Therefore, this has been the motivation and purpose of my work, develop the Emotional Intelligence and the teaching and learning of a foreign language (English), through a dynamic activity such as reading in a primary school classroom.Grado en Educación Primari

    El discípulo según el evangelio de Lucas. una mirada exegético-narrativa para el mundo actual a partir de tres relatos lucanos.

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    El objetivo principal de este trabajo es proponer una reflexión teológico-bíblica sobre algunos rasgos esenciales del discípulo a partir de la exégesis narrativa de los siguientes micro-relatos: Lc 10, 38-42; 19, 1-10; 24, 13-35.Universidad de San Buenaventura sede Bogot

    Factores que afectan el uso y/o comercialización del conocimiento codificado en patentes académicas

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    RESUMEN: Este trabajo presenta una revisión sistemática de literatura sobre los factores que afectan el uso y/o comercialización de las patentes producidas por las instituciones universitarias. Para ello se consideran aspectos institucionales (políticos-contextuales), organizacionales e individuales (a nivel de inventor). La revisión se hace a partir de cuatro fuentes secundarias: Scopus, Web of Science, Google Scholar y Lens.org, seleccionando un total de 100 documentos. Para el análisis se emplea la bibliometría y el análisis de contenido crítico, recopilando 289 factores. Tras su revisión, se identificaron seis categorías correspondientes a Recursos e infraestructura, Estrategia, Relacionamiento, Políticas, Estructura organizacional y capacidades, y Cultura. A raíz de la revisión de recurrencias, se consolidaron 36 factores, siendo el eje organizacional el de mayor número con 19. Los resultados muestran que el uso y/o comercialización de las patentes académicas es altamente complejo, en el que intervienen varios factores asociados a las políticas, la estrategia, los recursos, las capacidades y la cultura. Es necesario comprender su relación con los ejes institucional, organizacional e individual como clave para el diseño de estrategias, que puedan mejorar los procesos de transferencia en las universidades.ABSTRACT: This paper presents a systematic review of the literature on the factors that affect the use and / or commercialization of patents produced by university institutions. For this, institutional (political-contextual), organizational and individual aspects (at the inventor's level) are considered. The review is made from four secondary sources: Scopus, Web of Science, Google Scholar and Lens.org, selecting a total of 100 documents. Bibliometric and critical content analysis are used for the analysis, compiling 289 factors. After its review, six categories corresponding to Resources and infrastructure, Strategy, Relationship, Policies, Organizational structure and capacities, and Culture were identified. Following the review of recurrences, 36 factors were consolidated, the organizational axis being the one with the highest number of 19. The results show that the use and / or commercialization of academic patents is highly complex, in which several factors associated with policies, strategy, resources, capabilities and culture. It is necessary to understand its relationship with the institutional, organizational and individual axes as a key to the design of strategies that can improve the transfer processes in universities

    Effects of Nitrogen Deposition on the Abundance and Metabolism of Lichens: A Meta-analysis

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    Lichens are the key to nutrient cycling and trophic networks in many terrestrial ecosystems and are good bioindicators of air pollution, including nitrogen (N) deposition. Experimental studies have shown that N deposition can reduce the abundance of lichens and alter their thallus chemistry and metabolism, but we currently lack information about how widespread this effect is and what are the environmental factors modulating the response of lichens to N. We carried out a meta-analysis of the literature about the effects of experimental N fertilization on lichen abundance and metabolism. We found thirty-nine articles from thirty-one experimental sites that met our search criteria. These studies showed that the addition of N accelerates lichen metabolism in the short term and decreases their abundance in the medium–long term. Early senescence of lichens is proposed as a possible mechanism linking the two observed responses. Chlorolichens from regions with high precipitation (> 1000 mm) and with a background N deposition of mixed origin (agricultural and industrial) were the most affected by N, in terms of both abundance and metabolism. Structural equation modelling showed that the rate of N addition was the main factor in modulating the response of lichens to N in terms of metabolism, whereas isothermality played a very important role in modulating the lichen response to N in terms of abundance. Our meta-analysis identified that excess N deposition reduces lichen abundance and increases the metabolism of sensitive species, especially across European ecosystems; lichens from more climatically benign regions (that is, greater precipitation and isothermality) are the most affectedROH initiated this study being funded by a Juan de la Cierva-Incorporación Fellowship (JCI-2014-21252) from MINECO and finished it with the support of a Ramón y Cajal Fellowship (RYC-2017-22032) from MICIU. All data used in this study can be accessed from Ochoa-Hueso and Gutierrez-Larruga (2019)

    El rol del funcionamiento familiar y del apoyo social en el consumo de sustancias de los adolescentes

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    En el presente estudio se analizan las relaciones entre el funcionamiento familiar, la percepción de apoyo social de diferentes personas significativas (padre, madre, hermano/a, amigo/a y otro adulto) y el consumo de sustancias en una muestra de 625 adolescentes valencianos. Utilizando el cálculo de ecuaciones estructurales para el análisis de los datos, se observa que el funcionamiento en la familia se relaciona indirectamente con el consumo de los adolescentes a través de sus recursos de apoyo social percibido. Se observa un efecto protector del apoyo social percibido de los miembros de la familia frente a la implicación en el consumo de sustancias, mientras que el efecto es de riesgo cuando se trata del apoyo percibido de personas no pertenecientes al contexto familiar

    Concordancia de la tasa de filtración glomerular con depuración de creatinina en orina de 24 horas, fórmulas de Schwartz y Schwartz actualizada

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    ResumenIntroducciónLos métodos de referencia para cuantificar la tasa de filtración glomerular (TFG) son poco accesibles en la práctica clínica. Para evaluar la TFG se utilizan fórmulas basadas en la creatinina sérica y/o aclaramiento de creatinina. El objetivo de este estudio fue cuantificar la correlación y concordancia de la TFG con depuración de creatinina en orina de 24 horas (TFG24) y fórmulas de Schwartz y Schwartz actualizada.MétodosEstudio transversal analítico que incluyó pacientes de 5 a 16.9 años, sanos y con enfermedad renal crónica. Se evaluó la relación lineal entre la TFG24 y ambas fórmulas con el coeficiente de correlación de Pearson (r) y la concordancia con el coeficiente de correlación intraclase (CCI).ResultadosSe estudiaron 134 pacientes, 59.7% de género masculino, la edad promedio fue 10.8 años. La TFG24 promedio fue 140.34ml/min/1.73m2; el 34.3% (n=46) presentaron TFG<90ml/min/1.73m2. Se observó moderada relación lineal entre la TFG24 y las fórmulas de Schwartz (r= 0.63) y Schwartz actualizada (r= 0.65). Hubo buena concordancia entre la TFG24 y fórmula de Schwartz (CCI= 0.77) y de Schwartz actualizada (CCI= 0.77). En pacientes con TFG24 ≥ 90ml/min/1.73m2 la fórmula de Schwartz clásica estimó valores mayores de TFG, mientras que Schwartz actualizada subestimó los valores.ConclusionesExiste moderada correlación y buena concordancia entre la TFG24 y fórmulas de Schwartz y Schwartz actualizada. Con ambas fórmulas la concordancia fue mayor en pacientes con obesidad y menor en mujeres, pacientes con hiperfiltración y con peso normal.AbstractBackgroundReference methods for the quantification of the glomerular filtration rate (GFR) are difficult to use in clinical practice; formulas for evaluating GFR based on serum creatinine (SCr) and/or creatinine clearance are used. The aim of this study was to quantify the correlation and concordance of GFR with creatinine clearance in 24-hour urine (GFR24) and Schwartz and Schwartz updated formulas.MethodsCross-sectional study involving healthy pediatric patients and with chronic kidney disease (CKD) from 5 to 16.9 years. Linear correlation between GFR 24 and two formulas was evaluated with the Pearson correlation coefficient (r) and intraclass correlation coefficient (ICC).ResultsWe studied 134 patients, of which 59.7% were male. Mean age was 10.8 years. The average GFR24 was 140.34ml/min/1.73m2; 34.3% (n=46) had GFR <90ml/min/1.73m2. Moderate linear correlation between GFR24 and Schwartz (r= 0.63) and Schwartz updated (r= 0.65) formulas was observed. There was good concordance between the GFR24 and Schwartz (ICC= 0.77) and updated Schwartz (ICC= 0.77) formulas. Schwartz classical formula in patients with GFR24 ≥ 90ml/min/1.73m2 estimated higher values, while Schwartz updated underestimated values.ConclusionsThere is moderate correlation and good concordance between the GFR24 and Schwartz and Schwartz updated formulas. The concordance was better in patients with obesity and lower in women, patients with hyperfiltration and normal weight
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