Revistas Universidad del Bío-Bío
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Análise espaço-temporal do uso e cobertura da terra no município de Paranaguá, Paraná
Get PDFThe Atlantic Forest is a biome with only 8% of native vegetation remaining. The Great Atlantic Forest Reserve covers 50 municipalities in the states of São Paulo, Paraná, and Santa Catarina, aiming at their conservation. This study analyzed the land use and land cover changes for the years 2000 and 2020 in Paranaguá, PR. Using Landsat 5 TM (2000) and Landsat 8 OLI/TIRS (2020) satellite images, a supervised digital classification was performed on the Google Earth Engine platform. The classification's quality was assessed using the confusion matrix and Kappa index. As a result, two land use and land cover maps for Paranaguá in 2000 and 2020 were produced. The main changes observed were a 40.53% increase in the urban area class and a 10.51% decrease in the forest class. It is concluded that Paranaguá has good forest conservation due to the presence of Conservation Units, specific laws for land use and occupation, and being in an area with low agricultural propensity. In a further phase, these analyses will be extended to cover the entire Great Atlantic Forest Reserve.
A Mata Atlântica é um bioma com apenas 8% de vegetação nativa remanescente. A Grande Reserva da Mata Atlântica, abrange 50 municípios em SP, PR e SC e visa sua conservação. Esse estudo analisou as transformações no uso e ocupação da terra para os anos de 2000 e 2020 em Paranaguá, PR. Usando imagens Landsat 5 TM (2000) e Landsat 8 OLI/TIRS (2020). No Google Earth Engine, realizou-se a classificação supervisionada digital das imagens. A qualidade da classificação foi realizada pelo cálculo da matriz de confusão e do índice Kappa. Como resultado foram produzidos 2 mapas de uso e cobertura da terra de Paranaguá para o ano de 2000 e 2020. As principais mudanças observadas foram o crescimento da classe área urbana de 40,53% e uma diminuição da classe floresta de 10,51%. Conclui-se que Paranaguá apresenta uma boa conservação das florestas do município e isso se deve principalmente pelo fato da existência de Unidades de Conservação, leis específicas para uso e ocupação da terra e estar em uma área com baixa propensão para atividades agrícolas. Em uma próxima etapa pretende-se estender essas análises para toda a Grande Reserva da Mata Atlântica
Some physical and mechanical properties of Laminated Veneer Lumber reinforced with glass fiber mesh
Get PDFStructural composite lumbers are used extensively in wooden structures. There are many reasons for choosing these materials, including their light weight, easy assemble, and low cost. Various studies have been conducted to increase the load carrying capacities of these materials. Reinforcement with various natural or synthetic fibers is one method that has been studied. In this study, laminated veneer lumber was produced using poplar veneers and glass fiber mesh. One-component polyurethane glue was used in the production of the boards. The modulus of rupture, modulus of elasticity in bending, impact bending strength, and splitting strength values of the control laminated veneer lumber and laminated veneer lumber reinforced with the glass fiber mesh were investigated. In addition, some physical properties such as the densities and moisture contents of the test samples were investigated. Although the reinforcement of laminated veneer lumber using glass fiber mesh had statistically significant effects on impact bending strength, and splitting strength. The effect on the modulus of rupture and the modulus of elasticity in a static bending test was not significant. In addition, the effects of the reinforcement on the densities and moisture contents of the test samples compared the control samples were statistically significant
Editorial
Get PDFO ano de 2023 foi um marco climático alarmante, com as temperaturas mais altas desde que os registros climáticos são mantidos. Novembro, em particular, atingiu o valor mais alto para esse mês, com 2ºC acima do nível pré-industrial, elevando a média global anual em 1,25ºC acima da média pré-industrial. Esses dados mostram que estamos próximos de ultrapassar o limite de 1,5ºC estabelecido no Acordo de Paris[1] para 2045, com a expectativa de que esse limite seja ultrapassado em 2034[2] .
Sete anos após a implementação do Acordo, vemos um compromisso global crescente, com países, regiões, cidades e empresas estabelecendo metas de neutralidade de carbono. No entanto, 53,8 Gt CO2eq foram emitidos globalmente em 2022, o que representou 2,3% a mais do que em 2019, o ano anterior à pandemia de Covid-19. A China, os Estados Unidos, a Índia, a UE27, a Rússia e o Brasil emitiram 61,6% das emissões mundiais de gases de efeito estufa em 2022.
[1] O Acordo de Paris é um tratado internacional juridicamente vinculativo sobre mudanças climáticas. Ele foi adotado por 196 Partes na COP21 em 12 de dezembro de 2015 e entrou em vigor em 4 de novembro de 2016. Seu objetivo é limitar o aquecimento global, em comparação com os níveis pré-industriais, a menos de 2 e, de preferência, a menos de 1,5 graus Celsius.
[2] https://climate.copernicus.eu/weve-lost-19-years-battle-against-global-warming-paris-agreement2023 has marked an alarming climate milestone, with the highest temperatures since climate records began. November, in particular, reached its highest-ever figure, 2ºC above pre-industrial levels, raising the annual global average to 1.25ºC above the pre-industrial average. These data show that we are close to exceeding the 1.5ºC threshold set in the Paris Agreement[1] for 2045, currently predicting that this will be exceeded in 2034[2].
Seven years after the Agreement's implementation, we have seen a growing global commitment, with countries, regions, cities, and companies setting carbon neutrality targets. However, 53.8 Gt CO2eq was emitted globally in 2022, 2.3% more than in 2019, the year before the Covid-19 pandemic[3], with China, the United States, India, the EU27, Russia, and Brazil emitting 61.6% of the world's greenhouse gas emissions.
[1] The Paris Agreement is a legally binding international climate change treaty. 196 Parties at COP21 adopted it on December 12th, 2015, and came into force on November 4th, 2016. Its goal is to limit global warming, compared to pre-industrial levels, to below 2°C and, preferably, under 1.5°C.
[2] https://climate.copernicus.eu/weve-lost-19-years-battle-against-global-warming-paris-agreement
[3] Crippa, M., Guizzardi, D., Pagani, F., Banja, M., Muntean, M., Schaaf E., Becker, W., Monforti-Ferrario, F., Quadrelli, R., Risquez Martin, A., Taghavi-Moharamli, P., Köykkä, J., Grassi, G., Rossi, S., Brandao De Melo, J., Oom, D., Branco, A., San-Miguel, J., Vignati, E., GHG emissions of all world countries, Publications Office of the European Union, Luxembourg, 2023, doi:10.2760/953322, JRC134504.El año 2023 ha marcado un hito climático alarmante con las temperaturas más elevadas desde que existen registros climáticos. Noviembre, en particular, ha alcanzado la cifra más alta para dicho mes con 2ºC por encima del nivel preindustrial, elevándose la media global anual en 1,25ºC por encima de la media preindustrial. Estos datos evidencian que estamos próximos a sobrepasar el umbral de 1,5ºC fijado en el Acuerdo de París[1] para 2045, previendo que este límite se supere en 2034[2].
Siete años después de la implementación del Acuerdo, observamos un creciente compromiso global, con países, regiones, ciudades y empresas estableciendo objetivos de carbono neutralidad. Sin embargo, en 2022 se emitieron 53,8 Gt CO2eq a nivel mundial, lo que supuso un 2,3% más que en 2019, año anterior a la pandemia Covid-19[3]. China, Estados Unidos, India, la UE27, Rusia y Brasil emitieron en 2022 el 61,6% de las emisiones de Gases de Efecto Invernadero del mundo.
[1] El Acuerdo de París es un tratado internacional sobre el cambio climático jurídicamente vinculante. Fue adoptado por 196 Partes en la COP21, el 12 de diciembre de 2015 y entró en vigor el 4 de noviembre de 2016. Su objetivo es limitar el calentamiento mundial, en comparación con los niveles preindustriales, por debajo de 2 y, preferiblemente bajo 1,5 grados centígrados.
[2] https://climate.copernicus.eu/weve-lost-19-years-battle-against-global-warming-paris-agreement
[3] Crippa, M., Guizzardi, D., Pagani, F., Banja, M., Muntean, M., Schaaf E., Becker, W., Monforti-Ferrario, F., Quadrelli, R., Risquez Martin, A., Taghavi-Moharamli, P., Köykkä, J., Grassi, G., Rossi, S., Brandao De Melo, J., Oom, D., Branco, A., San-Miguel, J., Vignati, E., GHG emissions of all world countries, Publications Office of the European Union, Luxembourg, 2023, doi:10.2760/953322, JRC134504
Wood quality of 10 clonal progenies of rubber tree as raw material for bioenergy
Get PDFThe use of wood as a bioenergetic source requires knowledge of its technical properties. The rubber tree Hevea brasiliensis has an economic life cycle of 25 to 30 years in Brazil. It is used for extracting rubber and generating residual wood for fuel. Our goal was to characterize the wood quality of 10 clonal progenies as a source of raw material for bioenergy. Ten clonal progenies of 12-year-old Hevea brasiliensis from an experimental planting in Selvíria municipality were evaluated. Three trees per clone were evaluated for individual properties of Higher Heating Value, immediate chemical analysis, chemical composition, fiber dimensions, thermogravimetric analysis of wood under nitrogen atmosphere and Fourier Transform Infrared Spectrosocopy analysis. We highlight clone IAC 311 for fuel because it presents elevated Higher Heating Value and fixed carbon and less volatile material. However, the other genetic materials studied also meet the specifications for energy use and can be highly viable given their physical, chemical, energy, and thermal properties
Biosorption of methylene blue and malachite green from single and binary solutions by Pinus pinaster bark
Get PDFAiming to develop a sustainable separation process reducing the water pollution, in this work Pinus pinaster (cluster pine) bark from a wood veneer industry was used for methylene blue and malachite green removal from aqueous systems. For single adsorption, the influence of time (up 8 h), adsorbent dose (2,5 - 5- 10 g·L-1), temperature (25 ºC - 40 ºC - 60 ºC), pH (2 - 4 - 6) and particle size (0,1 mm - 0,5 mm, 0,5 mm - 1 mm and 1,6 mm - 2 mm) on adsorption was investigated. To study the initial concentration effect on binary adsorption, different concentrations (0 - 5 - 25 - 50 mg·L-1) were used at 25 ºC, natural pH and a dose of 5 g·L-1. High efficiency was obtained at pH = 4 (natural pH), dose of 5 g·L-1 and particle size of 0,5 - 1 mm.
Adsorption percentages higher than 70 % were reached in less than one hour, with removal almost complete at equilibrium in single systems, without temperature influence. Methylene blue was slightly better adsorbed b ybark. In binary systems, dyes exhibited competitive adsorption, decreasing their removal, especially increasing the ini- tial concentration of the other dye. Dyes adsorption followed the pseudo-second order kinetic model, whereas the Langmuir isotherm explained adsorption equilibria in mono-component systems. High adsorption capac- ities (41,7 mg·g-1 for malachite green and 50,0 mg·g-1 for methylene blue) were obtained at 40 ºC and natural pH indicating that pine bark can be effectively used as biosorbent
PERCEPCIONES DE ESTUDIANTES SOBRE SU EXPERIENCIA DE APRENDIZAJE EN PANDEMIA POR COVID19
No full textAs a result of the COVID19 pandemic, which imposed virtuality, the implementation of virtual education is accelerated and has an impact on the process of change that has been taking place in terms of the training of engineers by competencies focused on thestudent. For this reason, the students' perceptions regarding their experience in this situation are investigated. A mixed sample of students who took the 2020 Human Resources Administration subject in the first and second semester is taken. The resulting data on the self-perceptions of students about the development of their skills, their experience in virtuality and impact on pedagogical mediations through different theoretical perspectives. It is of a quantitative and exploratory nature using a virtual survey that allows establishing and understanding which are the most outstanding variables in relation to the phenomenon under study. As results we can express that the outstanding competencies in relation to learning were autonomous learning, time management and teamwork, for both groups, coinciding in the order of importance but not in the percentage of responses. Regarding the experience in virtuality, the second group has a more positive perception of their achievements when comparing virtuality with face-to-face in terms of their learning, the result of their previous journey. Finally, it is concluded that the transit through an imposed virtual education stage caused both students and teachers to develop and improve skills that positively impact the teaching-learning process.Producto de la pandemia por el COVID19, que impuso la virtualidad, se aceleró la implementación de la educación virtual e impactó en el proceso de cambio que se venía produciendo en cuanto a la formación de ingenieros por competencias centrado en el estudiante. Por tal motivo, se indaga cuáles son las percepciones de los estudiantes respecto de su experiencia ante esta situación. Se toma una muestra mixta de estudiantes que cursaron en el primer y segundo cuatrimestre la asignatura Administración de Recursos Humanos del año 2020. Se analizan los datos resultantes sobre las autopercepciones de los estudiantes acerca del desarrollo de sus competencias, su experiencia en virtualidad e impacto en las mediaciones pedagógicas a través de distintas perspectivas teóricas. El mismo es de carácter cuantitativo y exploratorio utilizando una encuesta virtual que permite establecer y comprender cuáles son las variables más destacadas en relación al fenómeno en estudio. Los resultados en cuanto a las competencias destacadas en relación al aprendizaje han sido aprendizaje autónomo, administración del tiempo y trabajo en equipo, para ambos grupos, coincidiendo en el orden de importancia, pero no en el porcentaje de respuestas.En cuanto a la experiencia en la virtualidad, el segundo grupo tiene una percepción más positiva de sus logros al comparar virtualidad y presencialidad en cuanto a sus aprendizajes, resultado de su recorrido previo. Finalmente, se concluye que el tránsitopor una etapa de educación virtual impuesta provocó tanto en estudiantes como docentes el desarrollo y mejora de competencias que impacta positivamente en el proceso de enseñanza-aprendizaje
Determination of processing characteristics of wood materials densified by compressing
Get PDFThe main objective of this study is to determine optimum cutting parameters in order to specify the effect of densification by compressing on the processing properties of solid wood material and to achieve the best surface quality in materials densified at different rates. In line with this goal, the widely grown and low-density black poplar (Populus nigra) tree species were selected as the experimental material. Samples, which were compressed and densified by Thermo-Mechanical method at 0 %, 20 % and 40 % ratios, were processed at 1000 mm/min, 1500 mm/min and 2000 mm/min feed speeds and in 12000 rpm, 15000 rpm, 18000 rpm rotation speed on a computer numerical control machine by using two different cutters. Surface roughness values (Ra and Rz) were measured in order to evaluate surfaces obtained. Smoother surfaces were obtained in computer numerical control machining of densified samples. The lowest surface roughness values occurred in 40 % densified samples, which were the densest. The lowest surface roughness was obtained when 40 % densified samples were processed with cutter no.1, at 1000 mm/min feed speed and at 18000 rpm
Feminicidio en Ciudad Juárez: Consideraciones al patriarcalismo
Get PDFThe study reviews the historical construction of the patriarchal narrative in Mexico, justifying it in the abominable murders that have been occurring in Ciudad Juarez. A hermeneutic approach of documentary and bibliographic analysis is used, considering three differentiated perspectives.
The first of these perspectives locates the participation of women in the public space and analyzes how politics becomes, over time, a forbidden place for women, as a result of practices and discourses that construct reality.
The second perspective reviews the exclusion of women's participation in economic activities and how it was not until the twentieth century, with the growth of cities and access to education, that they opened up to the possibility of paid work.
The third is the one that provides an epistemological foundation to the two previous ones, qualifying women in a negative way and establishing, through a narrative more than a thousand years old, a moral order that establishes the primacy of man over woman.
El estudio realiza una revisión de la construcción histórica del relato patriarcal en México, justificándose para ello en los abominables asesinatos que vienen ocurriendo en Ciudad Juárez. Se utiliza un enfoque hermenéutico de análisis documental y bibliográfico, considerando tres aristas diferenciadas.
La primera de estas aristas ubica la participación de la mujer en el espacio público y analiza cómo la política se convierte, con el tiempo, en un lugar vedado para las mujeres, producto de prácticas y discursos constructores de realidad.
La segunda arista revisa la negación de la participación de la mujer en las actividades económicas y como éstas recién en el siglo XX, con el crecimiento de las ciudades y el acceso a la educación, se abren a posibilidades de trabajo remunerado.
La tercera es la que entrega un fundamento epistemológico a las dos anteriores, calificando en forma negativa a la mujer y determinando, a través de un relato con más de mil años de antigüedad, un orden moral que establece la primacía del hombre sobre la mujer.
 
Aos olhos de Santa Lucía: arte urbana e organização comunitária no centro histórico de San Salvador
Get PDFA arte urbana tem sido e continua a ser uma componente transformadora nos processos de renovação urbana, por meio do fortalecimento da memória, da recuperação do sentido do lugar e da redução da estigmatização. Este artigo analisa em profundidade o papel da arte urbana nos processos de requalificação (físico-espacial) e ressignificação (simbólica) em favelas urbanas, avaliando como estes processos estão relacionados com o reforço do apego ao lugar, o sentido de pertencimento, o sentido de segurança e a organização comunitária, e buscando refletir sobre como estes processos podem influenciar questões mais profundas, tais como o risco social e ambiental. A metodologia utilizada é a investigação de ação participativa, desenvolvida em conjunto com a Comunidade de Santa Lucía, no Centro Histórico de San Salvador. Embora as limitações da arte urbana sejam claras face a problemas complexos como a violência urbana e o risco ambiental, o caso de Santa Lucía reflete o potencial destas intervenções quando emergem como uma expressão coletiva e consensual, tornando-se um instrumento de reivindicação do cidadão, reforçando os laços e a organização da comunidade.El arte urbano ha sido y sigue siendo un componente transformador dentro de los procesos de renovación urbana, a través del fortalecimiento de la memoria, la recuperación del sentido del lugar y la reducción de la estigmatización. El presente artículo ahonda en el rol del arte urbano dentro de los procesos de recualificación (física-espacial) y resignificación (simbólica), analizando cómo se relacionan estos procesos con el fortalecimiento del apego del lugar, el sentido de pertenencia, el sentido de seguridad y la organización comunitaria, y apuntando a reflexionar en cómo estos procesos pueden incidir en problemáticas más profundas como el riesgo social y ambiental en Asentamientos Populares Urbanos. En términos metodológicos, se trata de una investigación-acción participativa, desarrollada junto a la Comunidad Santa Lucía en el Centro Histórico de San Salvador. Si bien las limitantes del arte urbano son claras de cara a problemáticas complejas como la violencia urbana y el riesgo ambiental, el caso de Santa Lucía refleja el potencial de estas intervenciones cuando surgen como una expresión colectiva y consensuada, llegando a convertirse en un instrumento de reivindicación ciudadana y fortaleciendo los lazos y la organización comunitaria.Urban art has been and continues to be a transforming component within urban renewal processes, reinforcing memory, recovering the sense of place, and reducing stigmatization. This article delves into the role of urban art within the (physical-spatial) requalification and (symbolic) resignification processes in Urban Working-Class Settlements, analyzing how these processes are related to strengthening place attachment, sense of belonging, sense of security, and community organization, and trying to reflect on how they can affect deeper lying issues such as social and environmental risk. The methodology used is participatory action research, which was developed with the Santa Lucía Community in the Historic Center of San Salvador. Although the limitations of urban art are clear in the face of complex problems such as urban violence and environmental risk, the case of Santa Lucía reflects the potential of these interventions when they emerge as a collective and consensual expression, becoming an instrument of citizen vindication, strengthening community ties and organization
The use of herbal extracts in lacquer paint coloring and determination of some mechanical resistance properties on wood-based surfaces
Get PDFThe aim of this study was to determine the usability of selected natural dye extracts as environmentally friendly colorants that are used in painting of MDF based furniture and evaluate their resistance to scratch resistance, adhesion resistance, and surface hardness properties. In this study, the water-based lacquer coatings were prepared with natural dyes obtained from purple cabbage (Brassica oleracea), safflower (Carthamus tinctorius L.), Red beetroot (Beta vulgaris L.) and three synthetic paints that were black, blue and light blue as a comparison. Coated MDF test panels used for evaluation of performances of dyes to abiotic factors that are determined by mechanical tests such as scratch resistance, adhesion resistance, and surface hardness. As a result of the study, it has been observed that, except for scratch resistance, natural dyes perform as well as synthetic ones as alternative colorants in the lacquer coatings. Thus, natural and aesthetic raw materials that are environmentally friendly dyes can be used safely especially in children's furniture and for wood-based products that are especially used indoors