264 research outputs found
Estimation of the Efficiency of Hydraulic Pumps
A sustainable design of water supply systems needs to account operational costs. When pumping is required, the energy consumed by the pumps plays a major part in the operational costs, and the efficiency of the pumps can greatly affect the energy expenses. How to properly estimate the value of pump efficiency is hence of great importance. The aim of this study is to study in depth the efficiency of hydraulic pumps, in relation with the other design variables (flow rate, pumping head, power, etc.). For that, 400 hydraulic pumps were analysed. A strong relationship between the flow rate and the pump efficiency was observed. This relationship was interpolated, and three empiric curves were defined (one for the average maximum and minimum expected value of pump efficiency). These curves can be easily used by designers in order to obtain an estimation of the efficiency of the hydraulic pumps
Higher Education in Times of Pandemic. Experiences at the Orellana de la ESPOCH Headquarters
Education worldwide has been modified and led to new teaching canons due to the presence of the pandemic caused by COVID 19. Therefore, the objective of this research is to study the impact of COVID 19 on higher education, in this special case in the Higher Polytechnic School of Chimborazo, Sede Orellana. For this, the enrollments were analyzed from 2019 to the present, 30 students and 3 teachers from the different careers were interviewed. The main result is that the campus has been gradually increasing its students, reaching 911 students today, more than double that of 2019. This has increased more strongly in the pandemic. The teachers, in agreement with the students, affirm that careers should be created that allow not only faceto-face education, but also virtual education that allows education to be more widespread. So also that hybrid education be considered that combines virtuality with face-to-face to promote careers that require face-to-face practices, such as zootechnics, tourism, agronomy, among others.
Keywords: Covid 19, education in pandemic, Study in pandemic.
Resumen
La educación a nivel mundial se ha visto modificada y llevada a nuevos cánones de enseñanza debido a la presencia de la pandemia ocasionada por el COVID 19. Por lo cual el objetivo de esta investigación es estudiar el impacto del COVID 19 en la educación superior, en este caso especial en la Escuela Superior Politécnica de Chimborazo, Sede Orellana. Para ello se analizó las matrículas desde el 2019 hasta la actualidad, se entrevistó a 30 estudiantes y 3 docentes de las distintas carreras. El principal resultado es que la sede ha ido incrementando de manera paulatina sus estudiantes, llegando a tener 911 estudiantes en la actualidad, más del doble que en el 2019. Llegando a incrementar con mayor fuerza en la pandemia. Los docentes en coincidencia con los estudiantes afirman que se deben crear carreras que permitan que no solo la educación presencial, sino que se debe optar por una educación virtual que permita que la educación sea más extendida. Así también que se considere la educación hibrida que conjuga la virtualidad con la presencialidad para potenciar las carreras que necesitan de manera obligatoria practicas presenciales, como lo es la zootecnia, el turismo, agronomía entre otras.
Palabras Clave: Covid 19, educación en pandemia, Estuiar en pandemia
Bending behavior analysis of geogrid reinforced adobe walls
La tierra cruda constituye el material de construcción más importante en muchas regiones del planeta. Dado el riesgo sísmico existente en la mayor parte de estas regiones, es necesario el desarrollo de técnicas de refuerzo eficaces y adecuadas desde un punto de vista tecnológico y socioeconómico. Este artículo analiza desde un punto experimental y analítico el comportamiento a flexión de muros de adobe reforzados con geomallas. Las leyes momento-curvatura de los muros ensayados son aproximadas mediante una serie de modelos analíticos que permiten analizar el comportamiento del material compuesto adobe-geomalla. Los resultados obtenidos muestran como la geomalla mejora el comportamiento de la mampostería de adobe en términos de resistencia y ductilidad, mejorando así su comportamiento en caso de movimiento
sísmico.Rammed earth is a widely used building material in many regions of the world. Due to the high seismic risk in those
areas, earthen constructions require suitable and efficient reinforcement techniques from a technological and socioeconomic point of view. This paper analyzes the bending behavior of geogrid reinforced adobe walls from an experimental
and analytical point of view. The experimental bending moment-curvature relationships are analytically approached.
The results show how geogrid reinforcement improves the performance of adobe masonry in terms of strength and ductility. Thus, a better seismic performance is achieve
Bending behavior analysis of geogrid reinforced adobe walls
La tierra cruda constituye el material de construcción más importante en muchas regiones del planeta. Dado el riesgo sísmico existente en la mayor parte de estas regiones, es necesario el desarrollo de técnicas de refuerzo eficaces y adecuadas desde un punto de vista tecnológico y socioeconómico. Este artículo analiza desde un punto experimental y analítico el comportamiento a flexión de muros de adobe reforzados con geomallas. Las leyes momento-curvatura de los muros ensayados son aproximadas mediante una serie de modelos analíticos que permiten analizar el comportamiento del material compuesto adobe-geomalla. Los resultados obtenidos muestran como la geomalla mejora el comportamiento de la mampostería de adobe en términos de resistencia y ductilidad, mejorando así su comportamiento en caso de movimiento
sísmico.Rammed earth is a widely used building material in many regions of the world. Due to the high seismic risk in those
areas, earthen constructions require suitable and efficient reinforcement techniques from a technological and socioeconomic point of view. This paper analyzes the bending behavior of geogrid reinforced adobe walls from an experimental
and analytical point of view. The experimental bending moment-curvature relationships are analytically approached.
The results show how geogrid reinforcement improves the performance of adobe masonry in terms of strength and ductility. Thus, a better seismic performance is achieve
Experimental and Analytical Approach for the Assesment of Flexural Strength of Adobe Masonry
This paper presents an investigation about the flexural behavior of adobe masonry. It is focused on the development of constitutive models that can serve as a basis for the establishment of new design guidelines for adobe constructions, with special emphasis on seismic reinforcements. The paper analyzes the flexural behaviour of geogrid reinforced adobe walls. The experimental seismic tests of geogrid reinforced adobe houses have proven the effectiveness of the reinforcement technique. However, additional research is needed to develop constitutive models that can be used to quantify the actual performances of the reinforced adobe. For this purpose, bending tests have been carried out to obtain experimental curvature-moment relationships for reinforced and non reinforced adobe walls. Analytical models have been developed to approach these experimental laws, using equilibrium and compatibility equations similar to those usually applied for the flexural behaviour of reinforced concrete. The constitutive models of the individual materials are previously obtained through experimental tests, and simplified constitutive models are proposed for the governing equations. The analytical models show the ductility of adobe masonry, and how ductility increases when adobe is reinforced with geogrids. The proposed mathematical models and methodology can be applied to other structural elements and reinforcement systems. They can serve as a basis for the development of new design guidelines for adobe masonry
Exposure to Smoking Imagery in Popular Films and Adolescent Smoking in Mexico
Background: Exposure to smoking imagery in films in consistently associated with smoking behavior and its psychological antecedents among adolescents in high-income countries, but its association with adolescent smoking in middle-income countries is unknown.
Methods: In 2006, a cross-sectional sample of 3876 Mexican adolescents in secondary school was surveyed on smoking behavior, smoking risk factors, and exposure to 42 popular films that contained smoking. Participants were classified into quartiles of exposure to smoking imagery across all films they reported having seen. Models were estimated to determine associations among quartiles of film-smoking exposure, smoking behavior, and the psychological antecedents of smoking, adjusting for age, gender, sensation seeking, self-esteem, parental smoking, sibling smoking, best-friend smoking, having a bedroom TV, and private versus public school attendance. Analyses were conducted in 2007.
Results: Adolescents were exposed to an average of 51.7 (SE=1.3) minutes of smoking in the films they viewed. Crude and adjusting ORs indicated positive associations between quartiles of film-smoking exposure and both current smoking (AOR4v1=3.13; p\u3c0.0001) and having ever smoked (AOR4v1=2.42;p\u3c0.0001). Data from never-smokers (n=2098) were analyzed to determine associations between film-smoking exposure and psychological antecedents of smoking uptake. Crude and adjusted coefficients indicated significant, positive associations between exposure and susceptibility to smoking (AOR4v1=1.66; p\u3c0.05); favorable attitudes toward smoking (Adjusted B4v1=0.44;p\u3c0.0001); and perceived peer prevalence of smoking (Adjusted B4v1=0.26; p\u3c0.0001).
Conclusions: Exposure to smoking in films appears associated with smoking among Mexican adolescents. Policies could aim to decrease youth exposure to smoking in nationally and internationally distributed
Evaluación del impacto ambiental al extender la vida útil del teléfono móvil
El mercado de telefonía móvil ha experimentado un continuo crecimiento en la última década. Cada vez más, los teléfonos móviles son reemplazados por nuevos modelos con diseños más modernos y ampliación de funciones. Este estilo de vida está provocando incremento en la cantidad de residuos de aparatos electrónicos que no siempre reciben tratamiento. Por lo que, en este artículo, se presentan los resultados de la aplicación de la metodología de análisis de ciclo de vida (ACV) para calcular cuantitativamente el beneficio ambiental debido a la extensión de vida útil del teléfono móvil durante diferentes períodos. Tomando como unidad funcional el ciclo de vida promedio de 30 meses, se modelaron tres escenarios considerando cuatro etapas: adquisición de materias primas/producción, distribución, uso y fin de vida útil. Se utilizó el paquete SimaPro (2013), la base de datos Ecoinvent para configurar el inventario y las emisiones consideradas se asignaron en seis categorías de impacto según el método CML2000 del Centro para Estudios Medioambientales (CML). Se observó que al prolongar la vida útil del teléfono móvil y dar tratamiento cuando se convierte en residuo representa una ganancia ambiental no sólo porque se evita su disposición y consumo de uno nuevo, sino porque se ahorran recursos limitados y la energía necesaria para su extracción a través de la recuperación de materiales. Sin embargo, antes de reciclar es importante considerar su reutilización (extensión de su vida útil) ya que una cantidad sustancial de los móviles son dispuestos por razones de moda o estética mientras aún son funcionales.The mobile phone market has experienced continuous growth over the last decade. Increasingly, mobile phones are replaced by new models with more modern designs or expansion of functions. This lifestyle is causing increasing amount of electronic waste that do not always receive treatment. This article presents the results of the application
of the methodology for life-cycle assessment (LCA) to calculate quantitatively the
environmental benefit due to the extension of lifespan mobile phones during different
periods of time. Taking as a functional unit the life cycle of an average mobile phone
during 30 months and considering the stages of raw materials/production, distribution,
use and end of life, three scenarios were modeled. The SimaPro (2013) software was
used, the Ecoinvent database has been applied to configure the life cycle inventory,
and the emissions were allocated into six categories according to the impact CML2000
method. It was observed that to extend the mobile phone useful life and to provide
treatment when it becomes a waste, represents an environmental gain not only because
the provision and consumption of a new one is avoided, but because limited resources
and energy required for extraction are saved through recovery of materials. However,
before recycling it is important to consider reuse (extending lifespan) because a substantial
amount of the mobile phones are discarded for fashion or cosmetic reasons
while they are still functional
The relationship of Charlson comorbidity index and postoperative complications in elderly patients after partial or radical nephrectomy
Objectives: To compare preoperative Charlson comorbidity Index (CCI) and postoperative complications after oncologic kidney surgery in patients aged 70 or older. To compare CCI and need for interdisciplinary evaluation, consults to the emergency department and need of readmission are secondary objectives.Patients and methods: This is a retrospective cohort study. Patients aged 70 or older who underwent partial or radical nephrectomy were collected from an institutional database. Period: February 2012–June 2014. Association between CCI and complications was estimated using Chi2.Results: Final population: 143 (male: 65%). Age median was 75. Minor postoperative complications were 33.88% (n = 41) for patients CCI ≤ 4 versus 9.09% (n = 2) for patients CCI > 4 (p > 0.05), and major postoperative complications were 9.91% (n = 12) versus 45.45% (n = 10), respectively (p < 0.01). Interdisciplinary evaluation was required for 30.6% (n = 37) of patients CCI ≤ 4 versus 59% (n = 13) of patients CCI > 4 (p = 0.01). Readmission was needed for 9.09% (n = 11) and 40.1% (n = 11) respectively (p < 0.01).Conclusions: Patients with high comorbidity presented more major postoperative complications. These patients also required more interdisciplinary evaluation after surgery. A higher CCI was not associated with further consults to the emergency department or readmission
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