Portal de Revistas Académicas UC Temuco
Not a member yet
1040 research outputs found
Sort by
Bond strength properties of confined and unconfined coconut shell aggregate concrete by beam splice test
Get PDFThis study investigates the bond strength properties of a green concrete produced by replacing the coarse aggregate by an agricultural by product, coconut shell (CS). The bond between steel reinforcement and coconut shell aggregate concrete was studied by using 60 numbers of beam splice specimens. Confined and unconfined beam splice specimens were used. The effects of rebar diameter of lap splice and types of aggregate were investigated. It was observed that the percentage reduction in bond stress for 16 mm rebar unconfined beam splice specimens for various percentage replacements of CS from 25% to 100%, lies in the range of 6-8% compared to 12 mm rebar specimens. Whereas, for confined beam splice specimens the range of percentage reduction is 6-10%. For unconfined and confined beam splice specimens, percentage reduction in bond stress for 25% to 100% replacement by CS for each 25% increment was approximately in the range of 2-3%, 20-23%, 31-34% and 47-48% respectively with respect to normal concrete for both 12mm and 16mm rebar specimens. The percentage increase in bond stress by confining the specimens for various percentage replacements of CS and different size rebar lies in the range of 52-58%.
Keywords: coconut shell aggregate concrete, bond strength of concrete, beam splice tes
Microplastics as contaminants in marine environment
Get PDFABSTRACT
Since the mass production of plastics began in the 1940s, microplastic contamination of the marine environment has been a growing problem. Here, a review of the literature has been conducted with the following objectives: To summarise what are microplastics; To discuss the routes by which microplastics enter the marine environment; To assess spatial and temporal trends of microplastic abundance; to discuss the environmental impact of microplastics; and remedial measures; Microplastics are both abundant and widespread within the marine environment, found in their highest concentrations along coastlines and within mid-ocean gyres. Ingestion of microplastics has been demonstrated in a range of marine organisms, a process which may facilitate the transfer of chemical additives or hydrophobic waterborne pollutants to biota. A case study has also been done about the ingestion of microplastics by zooplankton groups in Kenya’s marine environment. We conclude by highlighting key future research areas for scientists and policymakers.
Keywords—Micro plastics; marine organisms; marine environmen
Potential & challenges of national waterway 3.
Get PDFKerala has a rich source of inland waterways, which can be used for the betterment of the state and country. One side of Kerala has a stretch of coastal line of the Arabian Sea and when it comes to the inland areas, the National Waterway 3 lies parallel to the Arabian Sea from Kollam to Kozhikode. This study deals with the actual potential of National waterway 3 which plays a prominent role in the commutation of goods and people. The inland waterways are the healthiest option in contrast to roads and railways, however it’s actual potential remains invisible for most people. The possibility of national waterway 3 is much higher if we deal with it in a better way. This study deals with the facilities, potential, relevance and challenges faced by the national waterway 3 and is presented from the information based on secondary data and information has been sourced from various books, trade journals, government publications newspapers and observations.
Keywords— National waterway, Inland, Coasta
Prediction of Joint Shear Strength of RC Beam-Column Joint Subjected to Seismic loading using Artificial Neural Network
Get PDFBC (Beam-column) joints are critical locations in RC frames subjected to severe earthquake attack. Failure of Joint which is of shear type is not an appreciable structural behaviour. Present study proposes an artificial neural network model for joint shear strength of reinforced exterior BC connections. ANN is a component of artificial intelligence which mimics the human brain characteristics and learns from previous experiences and has recently gained popularity in the area of civil engineering. A dataset of specimen dimensions, material properties, Area of Reinforcement used in Beam and column and failure mode are established from past experimental investigations on BC joints subjected to seismic type loading and are used for ANN modelling. ANN model is developed with eleven input parameters to predict the Joint shear strength of Exterior BC Joints. The Proposed model is compared with the equation given in design codes and empirical formula. Proposed ANN model has predicted the shear strength more accurately. Thus the proposed ANN model can be used for Prediction of Joint shear strength of Reinforced concrete exterior BC joints subjected to seismic loading.
Keywords— Joint Shear strength, Beam-Column Joint, Artificial neural networ
Seismic behaviour of post-tensioned concrete shear wall: a review
Get PDFShear walls are specifically meant to withstand lateral forces exerted by either wind or earthquake loads on a structure. Due to their superior strength and stiffness, shear walls have been an integral feature of mid-rise and high- rise structures over the past two decades. Various studies have been performed in this field. Usage of post-tensioned tendons in the traditional shear wall is one of the major advancements in recent times so as to increase the stiffness and reduce the damage incurred by destructive earthquakes. The key advantage of post-tensioned shear walls is the potential to re-centre after a devastating earthquake which is lacking in conventional reinforced concrete (RC) shear walls that rely on yielding creating large deformations. Moreover, compared with conventional shear wall construction, post-tensioned shear walls can reduce the use of vertical mild steel reinforcement. This results in materials being used more effectively and eliminates congestion. This paper seeks to review and analyze the research studies based on post- tensioned shear wall focusing on works published within the last decade. Firstly, the benefits of using post-tensioned shear walls in seismically active areas are illustrated. The behaviour and parameters controlling the performance of post-tensioned shear walls are then studied. A critical study of the factors responsible for the performance of post- tensioned shear wall is the primary objective of this review.
Keywords- Shear Wall, Post-Tensioning, Energy-Dissipation, Self-Centerin
Review on carbon capture and storage for construction engineering.
Get PDFGlobal warming and climatic changes due to pollution have triggered the global efforts to reduce the concentration of atmospheric carbon dioxide. The carbon dioxide capture and storage method is considered as a strategy or plan of action for meeting carbon dioxide emission reduction targets. This paper aims at providing an intensive review of various carbon capture and storage techniques, transportation of carbon dioxide & the utilization of this captured carbon dioxide in the construction industry. It also provides a huge perception of the manufacturing process of various construction materials using carbon dioxide. This review may present a clear understanding of the carbon upcycling technologies & everything we do is geared towards a goal of creating a circular economy & awaken new ideas to promote its practical application in construction materials.
Keywords-Carbon abatement technology, Carbon capture, Carbon storage, Carbon transportation, Safety and tracking
Circular economy in the wine industry: an agent based model for the wine supply chain
Get PDFIn the last decades, the concept of sustainability has driven many industries into a reconfiguration of their operations to reduce environmental impact. Accordingly, governments and public institutions are shaping the boundaries for new regulations, especially in the agriculture sector. Wine production is a major global industry, and its interest in becoming greener and more sustainable is growing. Since most of the wastes in the wine industry are attributable to organic composition, people share the belief that these wastes are not dangerous for the environment. However, the waste proportion in wine production is significant, reaching a 2:1 ratio, which means that for every two bottles of wine produced, the companies must discard a “bottle of waste”. This study concerns the winemaking process and the possibility to implement Circular Economy (CE) practices in it. The paper also shows several applications of circular economy in the wine sector, identifying benefits, drivers and actions that can lead towards more sustainable business models.
Keywords—Wine, wine industry, winemaking, sustainable, circular economy, business mode
La continuidad cultural en el Wallmapu: Reflexiones desde la arqueología mortuoria en los últimos 2000 años
Get PDFIt is proposed that there are elements of cultural continuity, beyond the material, between the populations that have inhabited the central south of Chile and Norpatagonia in Argentina during the last 2000 years. In order to integrate and link symbolic aspects of archaeological record, the Chezungunlinguistic area is taken as a reference. From a bioanthropological point of view, the wide mortuary variability from the Early Ceramic Period to the historical period is analyzed.Se plantea que existen elementos de continuidad cultural más allá de lo material entre las poblaciones que han habitado el Centro Sur de Chile y Norpatagonia argentina dentro de los últimos 2000 años. Para lograr integrar y vincular aspectos simbólicos del registro arqueológico se toma como referente el área lingüística del chezungun. Desde un punto de vista bioantropológico se analiza la amplia variabilidad mortuoria desde el período Alfarero Temprano al período histórico
Sobre la onto-fenomenología sartreana. Algunas derivaciones sobre la moral
Get PDFThis theoretical review summarizes our journey through the Sartrean work, placing emphasis on its onto-phenomenology, to identify some dilemmatic points that derive from it. The literature review is basically organized and two of his works for which we have deep respect: Being and Nothingness (SYN) and Critique of Dialectical Reason (CRD). In this posthumous text we think that the author remedies a certain attachment to the Cartesian cogito that still subsists in SYN and makes present an unjust and anthropophagic social order in a forceful way. The author talks about dilemmatic life, feelings and human experience, drowned out due to universal and abstract categories by idealism in all its aspects. We try to sketch his intellectual path from an ontophenomenology that is grounded on a conception of a person based on an excessive solipsism to another clearly linked to a historical person that is next to others. We will not emphasize the methodological aspects of the author’s work. This review aims, firstly, to identify the milestones of this Sartrean journey so as to indicate some of its vanishing points related to his conception of Morals. Esta revisión teórica resume nuestro recorrido por la obra sartreana, colocando énfasis en su onto-fenomenología para posteriormente identificar algunos puntos dilemáticos que derivan de ella. El recorrido bibliográfico básicamente se organiza en torno a dos de sus obras por las que sentimos profundo respeto: El Ser y la Nada (SYN) y Crítica a la Razón dialéctica (CRD). En este texto póstumo pensamos que el autor subsana cierto apego al cogito cartesiano que aún subsiste en SYN y hace presente de manera contundente un orden social injusto y antropofágico. El autor dialoga sobre la vida dilemática, los sentimientos, la experiencia humana, ahogadas por categorías universales y abstractas por parte del idealismo en todas sus vertientes. Tratamos de bosquejar su camino intelectual desde una onto-fenomenología que se apoya en una concepción del ser basada en un solipsismo excesivo a otra claramente vinculada a un ser histórico que es junto a otros. No haremos énfasis en los aspectos metodológicos de la obra del autor. La revisión apunta, en un primer momento, a identificar los mojones de ese recorrido sartreano para, posteriormente, indicar algunos de sus puntos de fuga relacionados con su concepción de la Moral
Transparencia algorítmica ¿un problema normativo o tecnológico?
Get PDFAs technology evolves, it will become increasingly frequent for decisions such as personnel selection, credit granting or partner selection, to be adopted by machine learning algorithms. Many of these decisions may contain biases that result in discriminatory decisions that affect the subject on whom the decision falls. In order to reveal how such decisions have been made, the idea of transparency in terms of algorithms has been used, implementing it through regulations. Such a normative or regulatory approach ignores a basic premise: transparency is not only a legal problem, but also a technological problem, which becomes relevant when we talk about machine learning algorithms. Machine learning algorithms are the basis for the development of a more sophisticated technology in automating processes than the classic programming approach, since it involves access to more powerful and flexible rules, which are automatically adjusted to the environment as the sample data evolve and recognize variations depending on many factors. However, the degree of sophistication of these algorithms leads to a complexity of their models, which generates a difficulty in their interpretation. The regulatory approach does not take into account the complexity mentioned above, what generates an insufficient and rigid regulatory framework. This article proposes to exceed this vision through flexible proposals, understanding the role of technology, recognizing its value and stimulating its use, this means proposals that promote and strengthen innovation in Chile. Con la evolución de las tecnologías, cada vez va a ser más frecuente que ciertas decisiones tales como selección de personal, otorgamiento de crédito o selección de parejas, sean adoptadas por sistemas de inteligencia artificial estructurados sobre la base de algoritmos de aprendizaje automático. Muchas de esas decisiones pueden contener sesgos que derivan en decisiones discriminatorias que afectan al sujeto sobre el que recae dicha decisión.Para revelar cómo se adoptaron dichas decisiones, se ha recurrido a la idea de transparencia en materia de algoritmos, implementándola a través de regulaciones. Dicho enfoque normativo o regulatorio resulta insuficiente para resolver el problema planteado, principalmente, porque ignora una premisa básica: la transparencia no es solamente un problema legal, sino también un problema tecnológico, que adquiere relevancia cuando se considera la naturaleza de los algoritmos involucrados, esto es, algoritmos de aprendizaje automático.Los algoritmos de aprendizaje automático, por su parte, constituyen una tecnología idónea para obtener una automatización de procesos más sofisticada, pues supone acceder a reglas más inteligentes, potentes y flexibles, que se van corrigiendo a medida que los datos de la muestra van evolucionando y reconociendo variaciones en función de muchísimos factores. Sin embargo, el grado de sofisticación de estos algoritmos conlleva una complejidad de sus modelos que, a su vez, inciden en la dificultad para su interpretación.El enfoque normativo desconoce la complejidad antes mencionada, generando un marco regulatorio insuficiente y rígido. El presente artículo propone superar dicha visión a través de propuestas flexibles, comprendiendo el rol de la tecnología, reconociendo su valor y estimulando su uso. En definitiva, propuestas que fomenten y fortalezcan la innovación en Chile