1,401 research outputs found
Heterogeneous catalytic ozonation of aniline-contaminated waters: A three-phase modelling approach using TiO2/GAC
This work aims to study the sustainable catalytic ozonation of aniline promoted by granular active carbon (GAC) doped with TiO2. Aniline was selected as a model compound for the Accelerator manufacturing industries used in the manufacture of rubber due to its environmental impact, low biodegradability, and harmful genotoxic effects on human health. Based on the evolution of total organic carbon (TOC), aniline concentration measured using high performance liquid chromatography (HPLC), pH and ozone concentration in liquid and gas phase, and catalyst loading, a three-phase reaction system has been modelled. The proposed three-phase model related the ozone transfer parameters and the pseudo-first order kinetic constants through three coefficients that involve the adsorption process, oxidation in the liquid, and the solid catalyst. The interpretation of the kinetic constants of the process allowed the predominance of the mechanism of Langmuir–Hinshelwood or modified Eley–Rideal to be elucidated. Seven intermediate aromatic reaction products, representative of the direct action of ozone and the radical pathway, were identified and quantified, as well as precursors of the appearance of turbidity, with which two possible routes of degradation of aniline being proposed.The authors are grateful to the University of the Basque Country for their financial support of this study through the PPGA19/63 project and C. Ferreiro’s predoctoral PIF grant (PIF16/367)
Eficacia de un programa de Entrenamiento de Intervalos de Alta Intensidad en la modificación de variables corporales en escolares preadolescentes de un colegio de la ciudad de Temuco, Chile
Introduction: High caloric intake and lack of physical activity are causing alarming increases in the amount of overweight and obese children. The objective of this study was to determinate the effectiveness of an High-Intensity Interval Training (HIIT) program in the reduction of fat percentage, improve nutritional status and physical abilities of schoolchildren.Material and methods: 153 schoolchildren between the ages of 7 and 10 from a subsidized private school in the city of Temuco (Chile), were randomly selected, distributed in an experimental group (EG) who were applied a 12 week HIIT intervention in physical education classes, twice per week and a control group. The percentage of fat by bioelectrical impedance analysis, weight, height, body mass index and functional capacity, were measured before and after the intervention, using the 6-minute walk test.Results: In EG, the parameters that showed significant improvements (p <0.05) were weight, fat percentage that decreased while the number of meters traveled in the 6-minute test increased. At comparing ages between 7-8 only the weight and the 6- minute test and for the aged between 9-10 years only the weight and meters traveled in the 6-minute test. While it is true that only in EG all variables show a downward trend, except in the size and in the meters traveled in the 6-minute test, only statistically significant differences were obtained in those mentioned previously. Conclusions: The HIIT program in schoolchildren showed improvement in the parameters related to overweight and obesity, which highlights the importance of including interventions of this type at the school resume of our country.Introducción: La alta ingesta calórica y la falta de actividad física están provocando alarmantes alzas en la cantidad de niños con sobrepeso y obesidad. El objetivo del estudio fue determinar la eficacia de un programa de Entrenamiento de Intervalos de Alta Intensidad (HIIT, por sus siglas en inglés) en la disminución del porcentaje de grasa, mejorar el estado nutricional y las capacidades físicas de los escolares.Material y métodos: Se seleccionaron 153 escolares de edades entre los 7 y 10 años de un colegio particular subvencionado de la ciudad de Temuco (Chile), distribuidos en un grupo experimental (GE), a los que se les aplicó una intervención HIIT de 12 semanas en las clases de educación física, dos veces por semana y un grupo control. Se midió previa y posteriormente a la intervención el porcentaje de grasa por análisis de impedancia bioeléctrica, peso, talla, índice de masa corporal y la capacidad funcional mediante el test de caminata de 6 minutos. Resultados: En GE los parámetros que mostraron mejorías significativas (p<0,05), fueron el peso, porcentaje de grasa que disminuyeron mientras la cantidad de metros recorridos en el test de 6 minutos aumentó. Al comparar entre las edades 7-8 sólo muestran diferencias estadísticamente significativas el peso y el test de 6 minutos y para los 9-10 años sólo el peso y metros recorridos en el test de 6 minutos. Si bien solo en el GE todas las variables presentan una tendencia a la baja, excepto en la talla y en los metros recorridos en el test de 6 minutos, únicamente se obtuvieron diferencias estadísticamente significativas en los que se mencionan anteriormente. Conclusiones: El programa HIIT en escolares mostró mejorías en los parámetros relacionados con el sobrepeso y obesidad, lo que resalta la importancia de incluir intervenciones de este tipo en el currículo escolar de Chile.
The effects of interset rest on adaptation to 7 weeks of explosive training in young soccer players
The aim of the study was to compare the effects of plyometric
training using 30, 60, or 120 s of rest between sets on explosive
adaptations in young soccer players. Four groups of athletes
(age 10.4 ± 2.3 y; soccer experience 3.3 ± 1.5 y) were randomly
formed: control (CG; n = 15), plyometric training with 30 s
(G30; n = 13), 60 s (G60; n = 14), and 120 s (G120; n = 12) of
rest between training sets. Before and after intervention players
were measured in jump ability, 20-m sprint time, change of
direction speed (CODS), and kicking performance. The training
program was applied during 7 weeks, 2 sessions per week, for a
total of 840 jumps. After intervention the G30, G60 and G120
groups showed a significant (p = 0.0001 – 0.04) and small to
moderate effect size (ES) improvement in the countermovement
jump (ES = 0.49; 0.58; 0.55), 20 cm drop jump reactive strength
index (ES = 0.81; 0.89; 0.86), CODS (ES = -1.03; -0.87; -1.04),
and kicking performance (ES = 0.39; 0.49; 0.43), with no
differences between treatments. The study shows that 30, 60,
and 120 s of rest between sets ensure similar significant and
small to moderate ES improvement in jump, CODS, and kicking
performance during high-intensity short-term explosive training
in young male soccer players
El entramado penal, las políticas públicas y la seguridad
156 p.El conflicto armado en Colombia es la causa principal de los crímenes, incluso de aquellos que se perciben como delitos comunes en el ámbito urbano. La producción del crimen en Colombia se estructura a partir de la delincuencia organizada, que va desde las organizaciones criminales, las pandillas, los grupos financieros, hasta los aparatos organizados de poder. En este contexto, la justicia transicional no es solo una herramienta para hacer tránsito hacia la paz, sino además un mecanismo de caracterización de la delincuencia y de desmantelamiento de dichas organizaciones.
En la otra orilla, el control de tan compleja criminalidad se ha venido poniendo en marcha, particularmente en las últimas décadas, a partir del discurso securitario, el cual elige enemigos a quienes vigilar y eliminar; por ello, vale la pena preguntarse por el contexto colombiano y la pertinencia de tan curiosas formas de control, máxime cuando su dinámica apunta hacia la eliminación de chivos expiatorios, mientras que las causas estructurales de producción de la violencia siguen indemnes.
El presente libro aborda estos temas desde diversas miradas, a partir de los dos conceptos básicos sobre los cuales se estructura todo el trabajo del grupo de investigación Conflicto y Criminalidad.Presentación
Capítulo 1. La degradación del conflicto armado interno en Colombia: causas y efectos
Capítulo 2. Análisis de los discursos securitarios de la política criminal desde las políticas de seguridad en Bogotá
Capítulo 3. La sostenibilidad de la política de paz para la terminación del conflicto armado interno en Colombia
Capítulo 4. La extradición en el gobierno de la Prosperidad Democrática: caracterización y análisis de la extradición pasiva a Estados Unidos entre 2011 y 2014
Capítulo 5. La justicia transicional no es justicia penal
Bibliografí
Prácticas pedagógicas que favorecen u obstaculizan la inclusión educativa en el aula de educación física desde la perspectiva del alumnado y profesorado
The aim of the present investigation was to analyze students’ perception of the practices that favor or obstruct educational inclusion in Physical Education settings. Also, to inquire about teachers’ beliefs on the subject. The study has an exploratory-descriptive scope and uses a mixed method. Participants included were 163 students in the 7th and 8th grade of the Temuco and Los Angeles, Chile, and 7 teachers of Physical Education at all levels, all of whom were intentionally selected. The instruments of data collection were a questionnaire of inclusive practices, and in-depth interviews. Factors that favor inclusion include physical education teachers’ personal skills, and the class as an environment that benefits relationships. As a hindrance factor, homogeneity of activities arises, constant competition, and hetero-evaluation as the main means to evaluate the achievement of students’ learnin
Analysis of a hybrid suspended-supported photocatalytic reactor for the treatment of wastewater containing benzothiazole and aniline
In this work, a study of the main operating variables affecting TiO2/UV photocatalysis was carried out. The treatment of an industrial effluent containing aniline and benzothiazole from the manufacture of accelerants for vulcanization was performed in a TiO2-supported commercial photoreactor. The degradation of both contaminants was monitored by GC-MS analysis. The proposed experiments were able to properly identify the phenomenon of adsorption, as well as to improve the performance of the commercial photoreactor by adding small amounts of TiO2 in suspension. The removal performance, durability of the photocatalytic material, and energy costs were analysed. The results showed that the use of suspensions intensifies the degradation obtaining an improvement of 23.15% with respect to the use of the supported catalyst. For an aniline and benzothiazole solution, the best operating conditions were found at pH = 12.0, introducing 60.0 mg L−1 of suspended TiO2 together with the existing supported catalyst
Removal of aniline and benzothiazole wastewaters using an efficient MnO2/GAC catalyst in a photocatalytic fluidised bed reactor
This work presents an efficient method for treating industrial wastewater containing aniline and benzothiazole, which are refractory to conventional treatments. A combination of heterogeneous photocatalysis operating in a fluidised bed reactor is studied in order to increase mass transfer and reduce reaction times. This process uses a manganese dioxide catalyst supported on granular activated carbon with environmentally friendly characteristics. The manganese dioxide composite is prepared by hydrothermal synthesis on carbon Hydrodarco® 3000 with different active phase ratios. The support, the metal oxide, and the composite are characterised by performing Brunauer, Emmett, and Teller analysis, transmission electron microscopy, X-ray diffraction analysis, X-ray fluorescence analysis, UV–Vis spectroscopy by diffuse reflectance, and Fourier transform infrared spectroscopy in order to evaluate the influence of the metal oxide on the activated carbon. A composite of MnO2/GAC (3.78% in phase α-MnO2) is obtained, with a 9.4% increase in the specific surface of the initial GAC and a 12.79 nm crystal size. The effect of pH and catalyst load is studied. At a pH of 9.0 and a dose of 0.9 g L−1, a high degradation of aniline and benzothiazole is obtained, with an 81.63% TOC mineralisation in 64.8 min
Avaliações feita por estudantes de pós-graduação da docência sobre a metodologia de investigação recebida no processo de graduação e sua utilização na prática docente
This article analyzes postgraduate teaching students’ evaluations of the training in research methodology received during their degree and its use in the teaching practice. The participants are students attending the Research Methodology course corresponding to a Master’s program, in the pedagogical field, at the Universidad del Bío-Bío, Chile. The methodology was qualitative, using open questionnaires and a discussion group. The data were analyzed using a categorical analysis and reduction, through ATLAS.ti 6.0. The main results show a critical view of the participants on the methodology and research training they received in undergraduate courses, as well as the insufficiencies in the training that is focused on the degree´s thesis design and not on giving tools to practice the profession. The participants questioned the role of the university in the education of teachers who do research. Regarding the uses of research methodology in the professional practice, although varied, they are limited by training deficits and institutional conditions. Despite their critics, the participants have high valuation of the significance of research methodology for the development of their professional practice. These results encourage us to suggest elements to nourish the debate about the way in which research methodology should be taught, as well as what research methodology is taught for, in order to contribute to the professional development processes of the teaching-research teams.Este artículo presenta el análisis de las valoraciones que estudiantes de un posgrado de profesión docente tienen sobre la formación en metodología de la investigación recibida en su pregrado y su uso en la práctica docente. El estudio se realizó en el marco de la asignatura de Metodología de la investigación, con estudiantes que cursan un programa de maestría en el ámbito pedagógico, en la Universidad del Bío-Bío, Chile. El enfoque es cualitativo. Las técnicas: el cuestionario de preguntas abiertas y grupo de discusión. El procesamiento se realizó con un modelo de análisis y reducción categorial con ATLAS.ti 6.0. Los principales resultados muestran la visión crítica de los sujetos participantes sobre la formación en metodología de la investigación recibida en pregrado; evidencian los déficits formativos, con una formación orientada a la realización de la tesis de grado y no a la entrega de herramientas para el ejercicio profesional, problematizan la intencionalidad de las universidades de querer formar profesorado investigador. Respecto de usos de la metodología de la investigación en el ejercicio profesional, estos, siendo variados, se encuentran muy condicionados por los déficits formativos y las condiciones institucionales. A pesar de los cuestionamientos del grupo de informantes, tienen una alta valoración de las potencialidades de la metodología de la investigación para el desarrollo de su ejercicio profesional. Estos resultados nos animan a sugerir elementos para nutrir el debate en torno a la forma en que se debe enseñar, así como para qué se enseña metodología de la investigación, a fin de contribuir a los procesos de desarrollo profesional del equipo docente-investigador.Este artigo apresenta a análise das avaliações feitas por estudantes de pós-graduação em docência, sobre sua formação em metodologia da investigação recebida em sua formação inicial do magisterio e seu uso na prática docente. O estudo foi realizado no âmbito do curso de Metodologia da investigação, com estudantes que participam de um programa de mestrado no campo pedagógico, na Universidade de Bío-Bío, Chile. A abordagem é qualitativa. As técnicas: o questionário de questões abertas e grupo de discussão. O processamento foi feito com um modelo de análise e redução categorial com ATLAS.ti 6.0. Os principais resultados mostram a visão crítica dos sujeitos participantes sobre a formação de metodologia de investigação recebida no bacharelato; mostram os déficits formativos, com uma formação voltada para a realização da tese de licenciatura e não para a entrega de ferramentas para o exercício profissional, problematizam a intencionalidade das universidades de querer formar professores pesquisadores. Quanto aos usos da metodologia de investigação na prática profissional, estes, sendo variados, são altamente condicionados por déficits de formação e condições institucionais. Apesar dos questionamentos por parte do grupo de informantes, ainda assim têm uma alta avaliação do potencial da metodologia de investigação para o desenvolvimento de sua prática profissional. Esses resultados nos estimulam a sugerir elementos que estimulam o debate em torno da maneira como se ensina, bem como para que se ensina a metodologia da investigação, a fim de contribuir aos processos de desenvolvimento profissional da equipe de ensino-pesquisa
Differences in the electromyography activity of a roundhouse kick between novice and advanced taekwondo athletes
P. 31-38Objetivo: el objetivo de este estudio fue determinar las diferencias en la activación muscular y el momento de máxima amplitud electromiográfica antes y después del impacto de la patada circular (bandalchagui) entre los atletas novatos y avanzados de taekwondo. Método: dieciséis competidores de taekwondo (cuatro mujeres) se clasificaron según los años de práctica en novatos (n = 8, 3 años de experiencia). Las variables de activación muscular y el momento de máxima amplitud electromiográfica se expresaron como un porcentaje con respecto a la máxima contracción isométrica voluntaria y el ciclo de patada, respectivamente. El tamaño del efecto se calculó con la d de Cohen y se estableció un nivel de significación de p .5). Se observaron diferencias post-impacto entre los grupos para el vasto medial (p = .041; d = .761). El momento de máxima amplitud de la electromiografía reflejó diferencias en ambas fases para bíceps y músculos semitendinosos (p .5). Conclusión: se observaron diferencias en la actividad electromiográfica por años de experiencia entre los atletas de taekwondo, que podrían considerarse para el control de entrenamientoS
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