Revistas Universidad del Bío-Bío
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Thermal performance of traditional east facing green facades in tract housing located in arid climates
Get PDFGreen infrastructure is a strategy for mitigating urban and building temperatures. This work assesses the impact of a type of Vertical Greenery System (VGS), the Traditional Green Façades (TGF), on the thermal condition of dwellings located in the Metropolitan Area of Mendoza, Argentina, whose climate is dry desert (BWk - Köppen-Geiger). To this end, two case studies were monitored for two consecutive summers: a dwelling with an east-facing TGF and a control dwelling of the same typology and materiality. Outdoor and indoor ambient temperature data were recorded: surface exterior and interior, and horizontal radiation. Decreases of up to 3.1°C in the indoor ambient temperature of FVT dwellings, of up to 27.4°C on exterior walls and 6.5°C on interior walls were found. The magnitudes of the results found show the potential of applying this strategy in an arid climate.La infraestructura verde constituye una estrategia de mitigación de las temperaturas urbanas y edilicias. El presente trabajo evalúa el impacto de un tipo de Sistema de Enverdecimiento Vertical (SEV), las Fachadas Verdes Tradicionales (FVT), en la condición térmica de viviendas localizadas en el Área Metropolitana de Mendoza, Argentina; cuyo clima es seco desértico (BWk - Köppen-Geiger). Con tal fin, se monitorearon, durante dos veranos consecutivos, dos casos de estudio: una vivienda con FVT, en orientación este, y una vivienda testigo de igual tipología y materialidad. Se registraron datos de temperatura ambiente exterior e interior; superficial exterior e interior y radiación horizontal. Se hallaron disminuciones de hasta 3.1°C en la temperatura ambiente interior de las viviendas con FVT, de hasta 27.4°C en muros exteriores y de 6.5°C en muros interiores. Las magnitudes de los resultados encontrados demuestran el potencial de la aplicación de esta estrategia en un clima árido
Prefabricated buildings in Chile: energy diagnosis, 40 years after their construction. Case study: KPD buildings, Santiago de Chile.
Get PDFLos edificios KPD son construcciones habitacionales sencillas y discretas, pero emblemáticas en Chile. Su recorrido histórico por este país inicia con un terremoto y se entrelaza con los antagónicos gobiernos de Salvador Allende y Augusto Pinochet. Estas construcciones han permanecido ajenas a las actualizaciones de la reglamentación térmica, pasando a formar parte del extenso parque habitacional construido que necesita ser diagnosticado energéticamente, para alinearlo a las exigencias térmicas nacionales y, de ese modo, mejorar la calidad de vida de sus habitantes y aportar a la carbono-neutralidad ya comprometida por Chile. Este artículo presenta un estudio de caso de evaluación de confort térmico en un conjunto habitacional de edificios KPD, ubicado en la Región Metropolitana. En concreto, se analizan cuatro edificios, idénticos en materialidad y distribución, pero con diferentes orientaciones. La metodología de evaluación consideró un triple enfoque: normativo, de etiquetado y subjetivo; e involucra a los habitantes en el diagnóstico, quienes constante e inexplicablemente, han quedado marginados en el análisis de sus propias viviendas. Los resultados del estudio han evidenciado discrepancias entre la percepción de los residentes y el rango de confort que utiliza la calificación energética nacional vigente.KPD residential buildings, although simple and discrete, are emblematic of Chile. Their story in this country starts with an earthquake and is intertwined with the antagonistic governments of Salvador Allende and Augusto Pinochet. These buildings have remained outside current thermal regulations, and have become part of an extensive built housing stock that need to be diagnosed in terms of energy, to align them with domestic thermal requirements and, in this way, improve the quality of life of their inhabitants and contribute to what Chile has already committed to in terms of carbon neutrality. This article presents a thermal comfort evaluation case study of a KPD residential building complex in the Metropolitan Region. Concretely, four buildings are analyzed, each with the same materials and distribution, but with different orientations. The evaluation methodology considered a three-fold approach: regulatory, labeling and subjective and involved their inhabitants in the diagnosis, who had constantly and inexplicably been marginalized in previous analyses of their own homes. The results show discrepancies between the residents’ perception and the comfort range used by the current energy rating system in Chile
The internal factors of SMEs and their influence on competitiveness (Case trade in Lazaro Cádernas Michoacán)
Get PDFEl presente estudio pretende identificar los factores internos y externos que influyen en la competitividad de las Pymes del sector abarrotero de Lázaro Cárdenas Michoacán ya que la competitividad es un aspecto que adquiere cada vez mayor relevancia en el ámbito empresarial, lo cual se deriva de las exigencias del entorno económico actual enmarcado en el proceso de la globalización. El desarrollo del sector privado, y en particular de las pequeñas y medianas empresas (pymes), es de suma relevancia, ya que, los factores internos de las mismas como son: Planeación estratégica, capital humano, innovación, productividad, sistemas de información y aseguramiento de la calidad resultan cruciales para que estas hagan un uso eficiente de sus recursos y alcancen grandes niveles de productividad y competitividad.This study aims to identify the internal and external factors that influence the competitiveness of SMEs in the Lazaro Cárdenas Michoacán grocery sector, since competitiveness is an increasingly important aspect in the business sector, which derives from the demands of the current economic environment framed in the process of globalization. The development of the private sector, and in particular of small and medium-sized enterprises (SMEs), is of great importance, since the internal factors of these are: Strategic planning, human capital, innovation, productivity, systems of Information and quality assurance are crucial for them to make efficient use of their resources and reach high levels of productivity and competitiveness
From happiness to well-being: A view from positive psychology
Get PDFLa psicología es una disciplina científica que ha logrado una transversalidad de la cual no ha quedado exenta la educación. Específicamente, la psicología positiva surge como una herramienta que ayuda a las personas a perseguir sus metas, “reseteando” su estructura de pensamiento y adoptando medidas que les permitan “ver el lado bueno de la vida”. La felicidad es sin duda ese lado bueno por el cual la psicología positiva ha decidido enfocar su trabajo. Este estudio presenta la revisión cronológica de los precedentes de la psicología positiva, estableciendo los aportes sociales que genera la adopción de una educación emocional en los distintos niveles de escolarización y que los autores han abordado en el constructo de bienestar. Las principales conclusiones de los autores se centran en que una educación formal, de manera formativa y en los distintos niveles educativos, debe ir acompañada por una educación emocional a través de los conceptos de felicidad y bienestar, enriqueciendo de esta manera la cadena educativa conformada por profesores, alumnos, familias y la sociedad en general; algo que en psicología positiva podría encontrar sus bases según lo planteado por Seligman en su teoría de la motivación.Psychology is a scientific discipline that has achieved a disciplinary transversality from education has not been exempted. Precisely positive psychology emerges as a tool that helps people to pursue their goals, "resetting" their thinking structure and adopting measures that allow them to "see the bright side of life." Happiness is undoubtedly that good side on which positive psychology has decided to focus its work. This study presents the chronological review of the precedents of positive psychology, establishing the social contributions generated by the adoption of an emotional education at the different levels of schooling and that the authors have addressed in the well-being construct. The main conclusions of the authors focus on the fact that a formal education, in a formative way and at the different educational levels, must be accompanied by an emotional education through the concepts of happiness and well-being, thus enriching the educational chain made up of teachers, students, families and society in general; something that in positive psychology could find its bases according to what Seligman proposed in his theory of motivatio
Carbon fiber-reinforced polymers as a tensile reinforcement of the Pinus elliotti and Manilkara huberi wood species
Get PDFIn wood structures, the elements subjected to bending stresses, such as the beams, present a fracture initiated in the tensile region, and under these conditions, the use of laminated composite materials is presented as an alternative solution in the form of repair or reinforcement. This research aimed to evaluate the influence of the use of carbon fibers laminated composites in tensile reinforcement in the direction parallel to grain of Pinus elliotti and Manilkara huberi wood species. The Viapol two-component epoxy adhesive was used in the lamination and fixation of the unidirectional carbon fiber in the wood species. Ten specimens with no defects (reference) and 10 specimens were prepared for each crack length (25 and 50mm) with and without the reinforcement (60mm × 50mm) by the laminated composite. The tensile tests were performed in accordance with the requirements of the Brazilian standard ABNT NBR 7190 (1997). From the results of the statistical analysis, the use of the carbon fiber composite was able to restore the tensile strength of the cracked samples (partial or total) in relation to samples without defects, demonstrating the potential of the laminates in carbon fibers as an alternative solution in repair for both wood species
Mechanical behavior of dowel connection for timber-concrete composite rural bridges
Get PDFThis study focuses on the evaluation of the mechanical behavior of two types of connections for intended use in rural Timber‑Concrete Composite traffic bridges. The two connection types used were the “X” type connection – XD and the dowel type connection – PD. Firstly, static shear tests in small-scale specimens were performed in both connection types and higher results were obtained for the XD series, both for stiffness and load carrying capacity. Secondly, the PD connection was chosen, based on practical and economical aspects, for further testing also in small-scale specimens, including cyclic tests. The influence of the number of cycles in the connection stiffness and load carrying capacity was evaluated. It was concluded that the load carrying capacity increased after the application of a pre-defined number of load cycles and that the connection stiffness increased 80.6% and 34.1% after 10,000 and 1,000 cycles, respectively, for different applied load levels. Also the increase of load level in the cyclic tests affected the performance of the connection, leading to a decrease in stiffness
Effect of thermal treatment variables on the thermogravimetric properties of eucalypt wood
Get PDFThermal treatments have the effect of reducing the hygroscopicity and improving the resistance to microbiological attack of wood by the degradation of its chemical constituents. During the treatments, the mass of the wood is reduced, a factor that can affect the quality of the materials according to their use. The objective was to verify the effect of the thermal treatment variables on the thermogravimetric properties and the chemical composition of Eucalyptus grandis. The treatments were carried out in a vacuum oven with three atmosphere conditions - vacuum; N2; vacuum+N2 at temperatures of 140, 180 and 220 °C for 6 hours. It was observed that the mass loss during treatments differed only according to the temperatures used. The extractive content, total lignin and holocellulose presented significant changes only at 220°C in all three atmospheres. In the thermogravimetric analysis, the greatest value of residual mass was found in the treatment that used nitrogen and 220 °C, thus demonstrating that this treatment was more invasive, leading to the conclusion that the vacuum application can help to reduce the degradation of the constituents of the eucalypti wood. wood, which can lead to the production of thermally treated wood without great losses in the mechanical properties
Measuring and estimating shear force of one stapled and one-row multi stapled wood joints
Get PDFSince staple is the most used fastener in furniture frame, its holding capacity in solid wood joints is need to be known. Therefore, lateral shear resistance capacity of one stapled and one-row multi stapled joints constructed from Scotch pine, alder, and beech were investigated. Results showed that the joints constructed from beech with a density of 0,54 gr/cm3 yielded 4893 N, the 4 staples joints constructed from alder with a density of 0,51 gr/cm3 yielded 4487 N, and the 4 staples joints constructed from Scotch pine with a density of 0,45 gr/cm3 yielded 3498 N. Three and two staples connected joints also indicated decreasing trend when changing wood from beech to alder and Scotch pine. Results also indicated that increasing number of staple from 2 to 4 in one-row joints increased force of the joints. Two prediction formulas were derived to predict the shear of one-row multi stapled wood joints. Both formulas yielded remarkable results compared to actual laboratory test results
COGNITIVE BIASES AND LABOR PERFORMANCE: RATIONAL AND NON-RATIONAL ASPECTS
Get PDFThe objective of this research is to identify qualitatively and quantitatively the important cognitive biases for the work performance of the small and medium industries of the Valencia municipality, Carabobo state, Venezuela, in order to be able to solve and give indications of which are the elements that These companies must take into account, to redefine, achieve and seek better results, representative of a good job performance, in their rational and non-rational aspects. Methodologically, the research conforms to the quantitative positivist paradigm; being an exploratory, field and descriptive study, adjusted to the deductive method, using direct observation and a questionnaire; processing the data with Descriptive Statistics, for empirical evidence. The results have shown that the experts selected 15 elements, grouped into 4 cognitive biases: illusion of control (key bias), aversion to losses, selective perception, and overconfidence. It is concluded that the cognitive biases in order of importance, for the work performance of the SMEs addressed and their better productivity are: aversion to losses, excess of confidence and excess of illusion of control, considering these biases in non-rational aspects. El objetivo de la presente investigación es identificar cualitativa y cuantitativamente los sesgos cognitivos importantes para el desempeño laboral de las pequeñas y medianas industrias del municipio Valencia, del Estado Carabobo, Venezuela, con la finalidad de poder resolver y dar indicios de cuáles son los elementos que dichas empresas deben tomar en cuenta, para redefinir, alcanzar y buscar mejores resultados, representativos de un buen desempeño laboral, en sus aspectos racionales y no racionales. Metodológicamente, la investigación se ajusta al paradigma positivista cuantitativo; siendo un estudio exploratorio, de campo y descriptivo, ajustado al método deductivo, usando la observación directa y un cuestionario; procesando los datos con la estadística descriptiva, para una evidencia empírica. Los resultados han arrojado que los expertos seleccionaron 15 elementos, agrupados en 4 sesgos cognitivos: ilusión de control (sesgo clave), aversión a las pérdidas, percepción selectiva, y exceso de confianza. Se concluye que los sesgos cognitivos en orden de importancia, para el desempeño laboral de las PyMEs abordadas y su mejor productividad son: aversión las pérdidas, exceso de confianza y exceso de ilusión de control, considerando a estos sesgos en los aspectos no racionales