Portal de Revistas Académicas UC Temuco
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A review and analysis of control techniques in HVAC systems
Get PDFHeating Ventilating and Air Conditioning (HVAC) systems are the core energy-absorbing equipment in buildings. Building HVAC system with effective control technique can greatly reduce energy consumption. The high demand for HVAC system Placing in buildings, using an effective control technique to decrease the energy absorbing of the equipment while meeting the thermal comfort demands in buildings are the most important goals of control designers. The different control methods for HVAC systems. This paper defines control techniques used in HVAC systems, MATLAB/simulation design and implementation of controller’s technique with the transfer function for the HVAC system.
Keywords-HVAC, PID controller, MPC Controller, Adaptive Controller, Fuzzy Controller
Biofouling Impacts and Toxicity of Antifouling Agents on Marine Environment: A Qualitative Study.
Get PDFBiofouling from microorganisms, plants, barnacles, mussels or algae is a major problem for marine structures. Fouling leads to increased fuel costs due to increased frictional resistance on ships, and reduces reserve buoyancy of floating offshore structure, in addition to causing cage deformation and structural fatigue, impacting endurance of materials. The intrusion of invasive aquatic species (IAS) to new environments by ships is identified as a major threat to the world’s oceans. Marine fouling affects most manmade surfaces immersed in the sea, resulting in substantial losses. Anti-fouling paints tackle this problem to a certain extent. Extensive research is in progress in the antifouling technologies in maritime sector, with new products in compliance with International Maritime Organisation (IMO) regulations being developed. The most efficient solution to minimise fouling is to make surfaces unsuitable for settlers, coating them with Antifouling (AF) Paints containing toxic compounds. Most AF agents had Tributyltin (TBT), and has been phased out by IMO since 2008 due to harmful effect on environment. However, use of TBT in AF paints is not prohibited, though has been restricted in several countries. The environmental problems by biofouling and toxicity of existing and alternative Anti-Fouling techniques are reviewed in this paper. Further, various ship hull cleaning technologies commercially available including afloat cleaning are also introduced.
Keywords— Biofouling, TBT, Antifouling (AF), IAS, IMO, AFS, Alternative
Building integrated photovoltaics- an overview
Get PDFFrom the older concept of photovoltaic installation, which includes the addition of solar panels to a building’s roof, the construction technology has merged with the photovoltaics technology. The result is Building Integrated Photovoltaics (BIPV), in which integrating the architectural, structural and aesthetic component of photovoltaics into buildings. Building integration of photovoltaics (BIPVs) has been recognized worldwide as a pivotal technology enabling the exploitation of innovative renewable energy sources in buildings, acting as electric power generators within the new framework of smart cities. The standard semitransparent photovoltaic (PV) modules can largely replace architectural glass installed in the building envelopes such as roofs, skylights, and facade of a building. Their main features are power generation and transparency, as well as possessing a heat insulating effect. PV glass shows the same mechanical properties as a conventional, architectural glass used in construction. Additionally, it provides free and clean energy. Given these properties, PV Glass maximizes the performance of the building’s envelope. The cost of the PV system and its implementation is still significantly high in comparison to solar thermal systems.
Keywords: Building Integrated Photovoltaics, renewable energy, power generation, heat insulating effec
Quantitative risk analysis procedure for economic project sustainability.
Get PDFThe paper briefly explains the importance of quantitative procedures of risk analysis in large and medium scale projects for the sustenance of project economic sustainability. Globally, several construction projects are being descoped and tend to close out before attaining the initial project deliverables due to cost and schedule overruns. The quantitative methods can sieve the key factors and forecast the tangible impacts that can lead to schedule or cost variance in a project. It can guide the project stakeholders for timely decision making and mitigate the risks associated to achieve the project goals. Today, the quantitative methods are pivotal to analyze the impacts of Covid-19 crises in Construction industry which are increasingly apparent.
Keywords- Project economic sustainability, Risk analysis, Quantitative method
Folding house
Get PDFNowadays there is massive use of concrete in construction industry. To overcome this, new construction techniques and material is adopted for good living standard. Folding house is a technique that considered all the factors like sufficient space for living, economy, environmental issues and living standard. . The tendency for the cost effective and quicker construction pushed the folded structures made in reinforced concrete, and led to the construction realized in wood, steel and other modern materials that eventually experienced expansion .In this project we are introducing a cost effective folding house.
Keywords—folding house,cost effective and quicker constructio
A review on the influence of shrinkage reducing admixtures on concrete
Get PDFShrinkage cracking is a common source of distress in concrete structures. In addition to being unsightly, these cracks serve to accelerate other forms of damage in concrete, thereby shortening the service life of structures. One solution to reduce the potential for shrinkage cracking is to incorporate a shrinkage reducing admixture (SRA) in concrete mixtures. SRAs belong to a special type of organic chemicals (i.e., surfactants) that when mixed in water, reduce the surface tension of the liquid, and thereby reduce the magnitude of capillary stresses and shrinkage strains that occur when concrete is losing moisture. Various studies show that SRAs have proven to reduce drying, autogenous, and plastic shrinkage, which has been summarized in this literature.
Keywords—Shrinkage Reducing Admixtures, Surfactants, Drying shrinkage, Plastic shrinkage, Autogenous shrinkage
Effect of wind on performance of double slope solar desalination still for fresh water production.
Get PDFThis study aimed at investigating the effect of wind for double slope solar desalination still. Two double slope solar stills were designed, constructed and experimentally tested their performance depending up on the wind. One experiment carried out with a wind speed of 4m/s and other 3m/s. The results show that the variation in wind affects the fresh water production. Double slope solar desalination still with wind speed 4m/s gives 17.8% higher productivity compare to 3m/s.
Keywords: wind, freshwater production, desalination
PAPEL DAS PEQUENAS CULTURAS DE MILLETE NA SEGURANÇA ALIMENTAR DE SATPURA OCIDENTAL NO DISTRITO DE NANDURBAR (MS), ÍNDIA.
No full textABSTRACT
The term millet includes many small-grain cereals. Grain-based on size, millet is classified as the major and minor grain millet. In the study area cultivated proso millet (Mor), Foxtail millet (padi and rala) and Barnyard millet (banti), etc small millets. These crops occupied 31.35 percent of the total cultivated area and are mostly grown on the hill slope. Small millets cultivated during the rainy season and also unmanured and unfertilized conditions. Small millets are highly nutritious and are better in protein, oil, mineral, calcium content than rice and wheat. These small millets are usually cooked as rice after dehulling in the study area. Small millets are used as a substitute for rice flour in various snack foods. They were primarily stored in larger quantities in Kothi for up to fifteen years for food security and used as animal feed. Regular consumption of small millets reduces lifestyle (diabetes), cardiovascular, gastrointestinal diseases.
KEYWORDS: Cropping System, Food Security, Nutritional Value, Small Millet, Wooden Plough.RESUMEN
El término mijo incluye muchos cereales de grano pequeño. Según el tamaño del grano, el mijo se clasifica como el mijo de grano mayor y menor. En la zona de estudio se cultivaron mijo proso (Mor), mijo cola de zorra (padi y rala) y mijo de corral (banti), etc. mijo pequeño. Estos cultivos ocuparon el 31,35 por ciento del área total cultivada y se cultivan principalmente en la ladera de la colina. Mijo pequeño cultivado durante la temporada de lluvias y también en condiciones no abonadas y no fertilizadas. Los mijos pequeños son muy nutritivos y son mejores en proteínas, aceite, minerales y contenido de calcio que el arroz y el trigo. Estos pequeños mijos se suelen cocinar como arroz después de descascararlos en el área de estudio. Los mijos pequeños se utilizan como sustituto de la harina de arroz en varios bocadillos. Se almacenaron principalmente en grandes cantidades en Kothi durante un máximo de quince años para la seguridad alimentaria y se utilizaron como alimento para animales. El consumo regular de mijo pequeño reduce el estilo de vida (diabetes), enfermedades cardiovasculares y gastrointestinales.
PALABRAS CLAVE: Sistema de cultivo, Seguridad alimentaria, Valor nutricional, Mijo pequeño, Arado de madera.ABSTRATO
O termo painço inclui muitos cereais de grãos pequenos. Com base no tamanho do grão, o painço é classificado como o painço do grão maior e menor. Na área de estudo cultivou-se proso milheto (Mor), milheto Foxtail (padi e rala) e milheto Barnyard (banti), etc. painço pequeno. Essas safras ocuparam 31,35 por cento da área total cultivada e são principalmente cultivadas na encosta do morro. Painço pequeno cultivado durante a estação chuvosa e também em condições não adubadas e não fertilizadas. O painço pequeno é altamente nutritivo e tem melhor teor de proteína, óleo, mineral e cálcio do que o arroz e o trigo. Esses pequenos painços são geralmente cozidos como arroz após o descasque na área de estudo. O painço pequeno é usado como substituto da farinha de arroz em vários salgadinhos. Eles foram armazenados em grandes quantidades em Kothi por até quinze anos para segurança alimentar e usados como ração animal. O consumo regular de milho pequeno reduz o estilo de vida (diabetes), doenças cardiovasculares e gastrointestinais.
PALAVRAS-CHAVE: Sistema de cultivo, Segurança alimentar, Valor nutricional, Painço pequeno, Arado de madeira
Life below water and the fate of humanity: with special reference to the efforts by adidas towards reducing the effects of plastic waste on the marine life.
Get PDFMarine Pollution is all the human waste in terms of chemicals, unwanted substances, non-biodegradable waste such as plastic that is thrown into the Earth’s water. The origin of the marine pollution is varied human activity that takes place on land. Wherein industrialization on one has shown immense growth in the life of human beings on this planet, taking them to the era being ruled by artificial intelligence, this rapid and unprecedented growth has also lead to the demolish of the treasures of our oceans and water bodies. The Pacific Ocean has a plastic “garbage patch” of approximately 6, 20,000 sq miles. The plastic pollution, notedly, is the most harmful of the other pollution sources as it directly affects the life of corals through fibres, poisoning and trapping of sea animals in nets, wires etc. In 1972, London Convention was the first international agreement on protecting the oceans and the oceanic life. The 2006 London Protocol bans all the hazardous waste from being disposed in the sea. Companies like Adidas have started finding solutions to control, if not yet eliminate, hazardous human actions.
Keywords: marine life, pollution, human actions, water bodie
Precariedad, trabajo y reproducción: el trabajo de las mujeres en el sector exportador de uva en Chile y Brasil
Get PDFThe expansion of export agribusiness in Latin America leads to a growing feminization of the workforce. However, women are incorporated in this sector under unfavorable conditions- occupying low-skilled, low-income and temporary jobs. This article intends to investigate the precariousness of the working and living conditions of women who work as wage earners in San Francisco Valley (Brazil) and in Elqui/Limarí Valley (Chile) grape export sector, putting forward an analysis that integrates both the sphere of production and reproduction. The aim of this article is to contribute to identify the existing interconnections between productive and reproductive universes, as well as the main mechanisms implemented by companies for extracting surplus value and outsourcing costs to households. La expansión del agronegocio de exportación en Latinoamérica ha ido acompañado de una creciente femeinización de la fuerza de trabajo. No obstante, las mujeres han sido incorporadas en condiciones poco favorables, ocupando empleos de baja calificación, bajos ingresos y temporales. El presente artículo propone investigar la precariedad de las condiciones de trabajo y de vida de las mujeres que trabajan como asalariadas en el sector de exportación de uva en el Valle San Francisco (Brasil) y en el Valle de Elqui/Limarí (Chile), proponiendo un análisis que integra tanto la esfera de la producción como de la reproducción. Esto con la finalidad de identificar las interconexiones existentes entre ambos ámbitos así como los principales mecanismos de extracción de plusvalor y de externalización de los costos a los hogares, implementados por las empresas