Revistas Universidad del Bío-Bío
Not a member yet
3557 research outputs found
Sort by
The effects of bioincising by Physisporinus vitreus on cuo retention and copper element leaching in oriental spruce wood
Get PDFSince the treatability of Oriental spruce wood (Picea orientalis) with preservative solutions is difficult and considered as a refractory wood species, this study was intended to bring its treatability class by a bioincising process to the level of sapwood of Scots pine (Pinus sylvestris), a desirable wood species for the forest products industry. Bioincising process by Physisporinus vitreus fungus was applied to wood samples from sapwood and heartwood portions of spruce wood. The samples with two different weight loss groups (5–10 % and 10–15 %) in the bioincising process were used to detect changes in treatability with wood preservative solutions caused by the fungus. The bioincised and unincised control samples were treated with either micronized copper quat (MCQ) or alkaline copper quat type D (ACQ-D) wood preservative solutions by either dipping or vacuum methods. Following impregnation with the preservative solutions, the effects of the bioincising process on CuO (copper oxide) retention, and the leaching of Cu (copper) element were determined. The results showed that CuO retention levels increased after the bioincising process. Moreover, there was greater CuO retention in the spruce heartwood samples compared to the spruce and Scots pine sapwood samples. Amount of Cu element released from the Scots pine sapwood samples was found to be lower than that from the spruce sapwood and heartwood samples after the bioincising. process. The results suggest that the bioincising process by P. vitreus in refractory wood species might improve the treatability of wood by Cu-based wood preservatives
Predictive expressions for withdrawal force capacity of various size of dowels from particleboard and medium density fiberboard
Get PDFThe objective of this study was to develop predictive expressions for estimating the withdrawal force capacity of various size of beech (Fagus orientalis) dowels from medium density fiberboard (MDF) and particleboard (PB). Furthermore, effects of the base material type, dowel diameter, dowel penetration and adhesive type on withdrawal force capacity were investigated. Polyurethane (PU), polyvinyl acetate based D2, and polyvinyl acetate (PVA) adhesives were utilized for gluing of dowels. A total of 540 specimens were prepared for edge and face withdrawal force capacity tests including two material types (MDF, PB), three dowel diameters (6 mm, 8 mm, 10 mm), three dowel penetration depths (15 mm, 20 mm, 25 mm for edge, 6 mm, 9 mm, 12 mm for face), three adhesive types and five replications for each group. Specimens were tested under static withdrawal forces. Based on results of tests, predictive expressions that allow furniture engineers to estimate edge and face dowel withdrawal force capacity as a function of dowel diameter and dowel penetration were developed. Calculations showed that the expressions developed provided reasonable estimates for withdrawal force capacity of dowels. As a result of statistical analyses, material type, dowel diameter, dowel penetration, adhesive type and their four-way interaction have significantly affected the withdrawal force capacity of dowels. Test results also indicated that PU adhesive and MDF ranked the highest withdrawal force capacity among the adhesive and material types. Increasing either dowel diameter or penetration tended to have a positive effect on withdrawal force capacity. Dowel diameter was found to have a higher effect on withdrawal force capacity than dowel penetration
Política de suelo urbano en San Carlos de Bariloche (2001-2019). Aportes para un balance crítico.
Get PDFEste artículo aborda las políticas de acceso al suelo urbano en cuanto elemento central para garantizar condiciones de habitabilidad para los sectores populares. En ese marco, se analizan las alternativas de producción de suelo urbano desarrolladas en la ciudad de San Carlos de Bariloche, Río Negro, en el período post-crisis de 2001, en particular luego de la crisis habitacional de 2006-2008, hasta el año 2019, con la finalidad de realizar un balance crítico de la implementación de la política de producción de lotes con servicios. A partir de un abordaje metodológico documental y cualitativo, se examinan las diferentes operatorias iniciadas por el Estado municipal, atendiendo a las modalidades de adquisición del suelo, las formas de financiamiento de la infraestructura, los destinatarios y su forma de organización, entre otras variables. Los resultados de la investigación muestran un esfuerzo del gobierno local de San Carlos de Bariloche orientado a urbanizar 140 hectáreas de suelo urbano, pero también evidencian las limitaciones en la implementación de la urbanización del mismo. El trabajo intenta aportar a la discusión sobre las causas de la informalidad urbana y su relación con las políticas habitacionales y urbanas adoptadas desde los gobiernos locales en la región latinoamericana. La producción de lotes con servicios constituye un pilar fundamental de la política urbana, sin embargo, su abordaje en investigación ha sido acotado, por lo que este artículo procura, igualmente, dar cuenta de dicho vacío en la literatura especializada.This article addresses urban land policies as a key element to guarantee habitability conditions for the working class. With this in mind, the article analyzes the urban land policy developed in the city of San Carlos de Bariloche, Río Negro, in the post-crisis period of 2001, in particular after the housing crisis of 2006-2008, until 2019, in order to make a critical balance of the lots with utilities production policy. Starting from a documentary and qualitative methodological approach, the different operations initiated by the municipal State are examined, taking into account the modalities of land acquisition, the forms of infrastructure financing, the recipients, and their form of organization, among other variables. The results of the research show an effort by the local government of San Carlos de Bariloche to provide utilities to 140 hectares of urban land, but they also show the limitations in its implementation. The work attempts to contribute to the discussion on the causes of urban informality and its relationship with housing and urban policies implemented by local governments in Latin America. The production of lots with utilities is a fundamental pillar of urban policy, but its research has been limited. As such, the article also tries to account for this gap in the literature
El reconocimiento de los valores patrimoniales por la comunidad y el conjunto moderno de Pampulha
Get PDFO Conjunto Moderno da Pampulha é um complexo urbano situado em Belo Horizonte, Brasil, cujo contexto metropolitano apresenta grande complexidade em função de pressões da dinâmica urbana, de impactos ambientais da urbanização e da necessidade de gerir mudanças, preservando os atributos da arquitetura e da paisagem que propiciaram o seu reconhecimento como Patrimônio Mundial. Este artigo é parte de um estudo maior que investiga o reconhecimento pela comunidade dos valores conferidos pelos especialistas à paisagem cultural do Conjunto como patrimônio mundial. Devido às condições restritivas impostas pela pandemia da COVID 19, utilizou-se como instrumento para a pesquisa de campo um questionário online de acesso franqueado ao público em geral para a coleta de dados primários junto à comunidade. A análise das respostas obtidas no pré-teste do questionário, objeto deste artigo, demonstram o reconhecimento de elementos da paisagem e do Conjunto Moderno da Pampulha que contribuem para sua fruição e que o caracteriza como paisagem diferenciada no contexto da cidade.El Conjunto Moderno da Pampulha es un complejo urbano ubicado en Belo Horizonte, Brasil, cuyo contexto metropolitano es altamente problemático debido a las presiones de la dinámica urbana, los impactos ambientales de la urbanización y la necesidad de gestionar los cambios y preservar los atributos de la arquitectura y el paisaje que brindaron su reconocimiento como Patrimonio de la humanidad. Este artículo es parte de un estudio más amplio que investiga el reconocimiento de la comunidad de los valores conferidos por los especialistas al paisaje cultural del Conjunto como Patrimonio de la humanidad. Debido a las condiciones restrictivas impuestas por la pandemia de COVID 19, se utilizó un cuestionario en línea con acceso abierto al público en general, como instrumento para la investigación de campo para recopilar datos primarios de la comunidad. El análisis de las respuestas obtenidas en el pre-test del cuestionario, objeto de este artículo, demuestra el reconocimiento de elementos del paisaje y del Conjunto Moderno da Pampulha que contribuyen a su fructificación y que lo caracterizan como un paisaje diferenciado en el contexto de la ciudad.The Pampulha Modern Ensemble is an urban complex located in Belo Horizonte, Brazil, whose metropolitan context is highly problematic due to the pressures of urban dynamics, impacts from urban development and the need to manage changes and preserve architectural and landscape attributes that have led to its recognition as World Heritage. This article is part of a larger study that investigates the community's recognition of the values conferred by experts on that complex’s cultural landscape as a world heritage site. Due to the restrictive conditions imposed by the COVID 19 pandemic, an online questionnaire with open access to the general public was used as an instrument for the field research to collect primary data from the community. The analysis of the answers obtained from the questionnaire pre-test, object of this article, demonstrates the recognition of landscape elements and of the Pampulha Modern Ensemble that contribute to its fruition and that characterize it as a differentiated landscape in the context of the city
Estimación del impacto de la Universidad del Bío-Bío sobre la producción de la Región del Biobío
Get PDFLa Universidad del Bío-Bío es una institución de educación superior chilena, de carácter estatal. No hay un estudio que mida el aporte económico que haga la Universidad del Bío-Bío y sus diferentes personas relacionadas en la Región del Biobío. Por ello, utilizando una aproximación de la matriz insumo-producto de la Región del Biobíopara el año 2012 estimo el aporte que hacen al producto de la Región del Biobíola Universidad y las personas relacionadas a ella. Encuentro que la Universidad aporta a la producción de la región tanto directa como indirectamente, totalizando para el año 2020 483,049,705,595 for 2020, with wich I make a serie of propossals for the authorities of the University and the authorities of the education of the Region
Análisis comparado de conmutación interregional en la nueva Región del Biobío, Chile (años 2010-2017)
Get PDFThe study estimates and analyzes the information on the main dimensions and char-acteristics of inter-regional residence-work mobility in the "new" Biobío region in Chile, contained in the National Employment Survey of the Instituto Nacional de Estadística of the State of Chile, period 2010-2020. For the main destinations and origins of the commuters of the Biobío region, their relationship with the dynamics of the respective macro-economic and regional series is investigated in order to verify or reject the hypothesis of synchronicity of the productive cycles with the flow of commutators as a cause of labor mobility.El estudio evalúa el impacto de la pandemia, provocada por la propagación de la en-fermedad por coronavirus (COVID-19), sobre las principales dimensiones de la movilidad residencia-trabajo en la “nueva” Región del Biobío. De la Encuesta Nacional de Empleo (ENE), período 2010-2020, se estiman las series de destinos y orígenes de los conmu-tantes de la Región del Biobío, se investiga su comportamiento en el año 2020 y su rela-ción con la dinámica de las respectivas series macroeconómicas y regionales como el PIB, empleo, con el objeto de verificar o rechazar la hipótesis de sincronía de los ciclos productivos con el flujo de conmutantes como causa de movilidad laboral.
Además, se cuantifica el impacto económico de este proceso mediante el cruce de los conmutantes con los antecedentes de ingreso medio de los ocupados por territorio e in-gresos medios por actividad económica de la Región del Biobío
Influence of the multiday and continuous hot press on the physical, mechanical and formaldehyde emission properties of the particleboard
Get PDFIn this study, Its the influence of according to press, particleboards produced in two different press types which were multiday and continuous hot press, the thickness, density, bending strength, modulus of elasticity, internal bond, surface soundness, withdrawal of screw resistance, moisture, thickness swelling, water absorption, formaldehyde emission content were researched. 18 mm x 2100 mm x 2800 mm size particleboards were manufactured on the production line which was using urea-formaldehyde (F:U;1,07 moles), and 30 % pine, 40 % oak, 20 % beech and 10 % poplar waste mixture of the wood materials. According to results of the tests performed after the multiday and continuous hot press production of the boards; thickness (0,63 %), bending strength (1,27 %), moisture content (0,47 %), thickness swelling (37 %), and water absorption (39,9 %), modulus of elasticity (11,35 %), internal bond (7,22 %) were increased according to multiday hot press while density (2,7 %), surface soundness (18,81 %), withdrawal of screw resistance (14 %) and formaldehyde (57,12 %) decreased. Formaldehyde content,surface soundness, withdrawal of screw resistance are the most prominent properties influenced by continuous hot press
Effects of glue spreading rate and veneer density on sugi (Cryptomeria japonica) plywood adhesive penetration
Get PDFAn optimum adhesive penetration is needed to provide satisfactory bonding strength at the veneer–veneer interface. The effect of veneer density and glue spreading rate on the phenol formaldehyde adhesive penetration plot profile was determined. An X-ray apparatus was used to visualize the adhesive penetration of the plywood. The heartwood and sapwood veneer of Cryptomeria japonica with low, medium, and high veneer densities were made into plywood. The glue spreading rate was applied from 75 g/m2 to 225 g/m2 for the heartwood plywood and up to 300 g/m2 for the sapwood plywood (plus 75 g/m2 at every level of glue spreading rate). An X-ray apparatus with a low tube voltage successfully visualized the adhesive penetration plot profile. Based on the half-width calculation, the adhesive penetration depth ranged from 0,3 – 0,9 mm. The mean half-width was 0,5 mm. The adhesive concentration increased with increasing glue spreading rate. In contrast, it also showed that using different veneer densities and increasing glue spreading rates does not affect the half-width value as the adhesive penetrates deeper
Arquitectura pública: la primera Terminal de Ómnibus estatal para Mendoza (Argentina, 1969- 1972)
Get PDFThe architecture for transportation and mobility had, between the sixties and seventies, an intensive period of execution in Argentina, driven by a political context that advocated for development in all its forms. Innovative programs and technologies were used in a typology that posed challenges in resolution terms for the professionals of the time. Among the numerous works that were built in the country, this article highlights the Mendoza Bus Terminal project, one of the first built in a provincial capital that, planned in 1964, was inaugurated in 1972, after a short construction period. From the review of technical publications of the time, graphic documentation of the project, press clippings, government work, and an interview with the site’s main designer, this text, in historical terms, seeks to delve into the particular aspects of the ideation and execution of this urban landmark, a local reflection of the degree of progress in terms of technology and construction techniques, and the executive capacity of the provincial State.As arquiteturas de transporte e mobilidade tiveram entre os anos de 1960 e1970 um período de profusa execução na Argentina, impulsionado por um contexto político que defendia o desenvolvimento em todas as suas formas. Foram utilizados programas e tecnologias inovadoras em uma tipologia que impôs desafios em termos de resolutividade para os profissionais da época. Entre as inúmeras obras construídas no país,o presente artigo destaca o projeto doTerminal Rodoviário de Mendoza,um dos primeiros construídos em uma capital provincial que, planejado em 1964, foi inaugurado em 1972, após um curto período de construção. A partir da consulta de publicações técnicas da época, documentação gráfica do projeto, imprensa, obra governamental e uma entrevista com o principal idealizador da obra, este texto em chave histórica busca deter-se nas particularidades da concepção e execução deste marco urbano, reflexo local do grau de progresso em termos de tecnologia e técnicas de construção; bem como da capacidade executiva do Estado provincial.Las arquitecturas para el transporte y la movilidad tuvieron, entre las décadas del sesenta y setenta, un período de profusa ejecución en Argentina, impulsadas por un contexto político que propugnaba el desarrollo en todas sus formas. Programas y tecnologías innovadoras fueron empleados en una tipología que suponía desafíos en términos resolutivos para los profesionales de la época. Entre las numerosas obras que se construyeron en el país, el presente artículo destaca el proyecto de la Terminal de Ómnibus para Mendoza, una de las primeras construidas en una capital provincial que, planificada en 1964, llegó a inaugurarse en 1972, después de un acotado lapso de construcción. A partir de la consulta de publicaciones técnicas de época, documentación gráfica del proyecto, prensa, labores de gobierno y una entrevista al proyectista principal de la obra, este texto en clave histórica, busca detenerse en las particularidades de la ideación y ejecución de este hito urbano, reflejo local del grado de avance en materia de tecnología y técnicas constructivas, como también de la capacidad ejecutiva del Estado provincial
Apego al lugar y percepción del riesgo volcánico en personas mayores de Ñuble, Chile
Get PDFChile presenta un alto grado de exposición y susceptibilidad ante escenarios de riesgo de desastre y es, además, uno de los cinco países con más volcanes activos a escala global. A lo anterior, se suma el sostenido aumento del envejecimiento poblacional, lo que convierte a las personas mayores en un grupo vulnerable ante potenciales desastres socio-naturales. Sustentado en lo anterior, el presente trabajo busca comprender la relación entre el apego al lugar y la percepción del riesgo volcánico de personas mayores residentes en la zona de exposición del complejo volcánico Nevados de Chillán, en el sur de Chile. Por medio de un diseño de caso cualitativo, de corte fenomenológico, se aplicaron 15 entrevistas semiestructuradas y un grupo focal, cuyo análisis se realizó bajo la teoría fundamentada. Los resultados señalan que las personas mayores presentan una baja percepción del riesgo volcánico, lo que conlleva i) minimización de los peligros naturales del entorno, ii) conocimiento informal basado en experiencias previas, y iii) desconocimiento de las características del riesgo natural y sus consecuencias negativas. Por otra parte, el apego al lugar y la vulnerabilidad social no solo actúan como obstaculizadores contextuales de la aceptación del riesgo volcánico, sino que también impactan en la falta de implicancia, adquisición y despliegue de capacidades de afrontamiento individuales y colectivas. Como conclusión, sostenemos la importancia de incorporar tanto el “envejecimiento en el lugar”, como el agenciamiento activo de la población adulta mayor en los procesos de planificación y gestión local del riesgo de desastre socio-natural.Chile has a high degree of exposure and susceptibility to disaster risk scenarios, and it is among the top five countries in the world regarding active volcanoes. Meanwhile, sustained population aging is making the older population vulnerable to potential socio-natural disasters. This article, using these concepts, seeks to understand the relationship between place attachment and the perception of volcanic risk among the older population, focusing on older adults residing in the hazard zone of the Nevados de Chillán volcanic complex in the Ñuble Region in southern Chile. Using a phenomenological qualitative case design, 15 semi-structured interviews and a focus group were applied, with the analysis carried out based on grounded theory. The results indicate that the older population has a low perception of volcanic risk, entailing i) the minimization of the surrounding natural hazards, ii) informal knowledge based on previous experiences, and iii) ignorance of the natural risk characteristics and their negative consequences. On the other hand, it is seen that place attachment and social vulnerability act not only as contextual barriers to accepting the volcanic risk but also lead to a lack of engagement, acquisition, and deployment of individual and collective coping mechanisms. In conclusion, the authors outline the importance of including “aging in place” and the active agency of the older population in socio-natural disaster risk planning and local management processes