Últimos itens adicionados do Acervo: Universidade Católica de Temuco

A Universidade Católica de Temuco é uma institução privada confessional do Chile, fundada pelo bispo Alejandro Menchaca Lira em 1959.

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‣ Desarrollo de la Energía Mareomotriz en Chile

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
El presente artículo trata una revisión del estado del arte de la energía marina, que puede ser generada por las mareas o el oleaje, se analizaron las experiencias a nivel mundial, así como se estudió la factibilidad técnica y económica de la instalación de esta fuente de energía en Chile, específicamente para la industria del cultivo de salmón.; The present study is a review of marine energy sources, that can be generated by tidal or waves, it analyzed the experiences at worldwide level, and it was studied the technical and economical factibility of use of this energetic source in Chile, specifically in salmon farming industry. Keywords: marine energy, tides, wave, aquaculture.

‣ Estimation of aerial biomass using discrete-wave LiDAR data in combination with different vegetation indices in plantations of Pinus radiata (D. DON), Región del Maule, Chile.

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The aerial biomass of Pinus radiata plantations in the Región del Maule, Chile, was estimated from linear models using databases of LiDAR and multispectral LANDSAT ETM+. Six descriptive height variables were obtained from the LiDAR point cloud; the 25%, 50%, 75%, 95% and 100% percentiles and the mean height. Two variables associated with the density of points were also obtained, which relate the returns between fixed weighted intervals calculated as a function of the observed biomass. For multispectral variables we used NDVI, corrected NVDI (NDVIc) and the “Tasseled Cap” components brilliance, greenness and humidity. The results showed coefficients of determination (R2) between 0.801 and 0.814, with errors between 36.07 and 36.11 ton ha-1 for the models generated using height percentiles, and R2 from 0.807 to 0.823 with errors between 36.06 and 36.84 ton ha-1 for transformed LiDAR data. Finally, the stepwise model using all available variables had R2 of 0.821-0.835 with errors of 34.28 - 36.31 ton ha-1.; La biomasa aérea en bosques de pino insigne en la región del Maule, Chile, fue estimada utilizando modelos lineales sobre la base de datos LiDAR y multiespectrales de LANDSAT ETM+. De la nube de puntos LiDAR se obtuvo un total de seis variables descriptivas de altura...

‣ Distribución y diversidad de crustáceos zooplanctónicos en lagos y lagunas de la región de la Araucanía, Chile: Orden Calanoida y Cyclopoida (Maxillopoda, Copepoda)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Los ensambles zooplanctónicos en los ecosistemas acuáticos chilenos se caracterizan por presentar un bajo número de especies y un alto predominio de copépodos. El objetivo de este trabajo es presentar la diversidad y distribución de crustáceos zooplanctónicos de los órdenes Calanoida y Cyclopoida en la región de la Araucanía, Chile. Se registraron un total de 8 especies siendo mayor la diversidad de copépodos ciclopoideos, sin embargo los calanoideos fueron más dominantes. De los crustáceos, el orden Cyclopoida es el menos estudiado, existiendo errores en su nomenclatura.

‣ Aves en un humedal boscoso costero de la región de la Araucanía: Humedal de Mahuidanche

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Los humedales son considerados los ecosistemas de mayor riqueza biológica del planeta, destacándose por su gran productividad y biodiversidad (Kusler et al. 1994; Innis et al. 2000), los cuales otorgan variadas funciones como la contribución en los ciclos de vida de plantas y animales, hábitat, alimento, sitios de nidificación y refugio para numerosas especies de animales (insectos, peces, batracios, crustáceos, aves, etc.) (Perotti et al, 2005; Correa-Araneda et al. 2011).

‣ Physico-chemical characterization of surface waters of the west coast of Algeria: Bay of Mostaganem and Cheliff estuary

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
A follow-up in 2013 of the indicators of pollution (temperature, hydrogen potential, salinity, dissolved oxygen, ammonium, nitrites, nitrates, orthophosphates, ortho silicates, biological oxygen demand, chemical oxygen demand, suspended solids) in surface water was performed, in order to estimate the physicochemical quality of the west coast of Algeria. The results obtained revealed the existence of a water contamination by domestic and industrial waste water conveyed to the north by the Cheliff River for discharge into the Bay of Mostaganem, marked by significant space-time variations. In January (24 mg / l), the values of nitrates recorded west of the mouth of Cheliff exceed norms. Ammonium records strong concentrations in January (1.2 mg NH4+/ l) and in February (0.8 mg /l). Nitrites such lagging of high contents in January (NO2- 0.99 mg / l) and February (NO2- 0.59 mg /l), respectively. The ortho phosphates post a maximum concentration in January (6.6mg PO43-/ l). In addition, the organic matter rate measured in surface water is maximum during periods of flooding especially in January (7.51 mg / l) and lowest in the exceptionally dry season in August (2.19 mg / l).

‣ Emprendimiento turístico rural y asociatividad: estudio en base a experiencias en chile y el mundo.

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The development of tourism in recent decades had led many types of tourism. Rural tourism is an example of this situation and this type of tourism is characterized by a respectful contact with the natural environment and interaction with the local people. Rural tourism arises in a context of agricultural diversification, which leads to innovation and incorporating activities; and also, rural tourism comes with a revaluation of rural. This activity has its origin in Europe; specifically, in France and Spain has a higher level of development. In these countries, there are economics incentives for entrepreneurship destined to rural people and municipalities; and also, France and Spain promotes associativity. In the Americas, rural tourism is still a novelty; only Argentina, Chile and Mexico have strong public programs on this issue. In these countries, there are touristic routes around a key food. In Chile, rural touristic entrepreneur are small farmers and they are networking in touristic routes.; El desarrollo de la actividad turística en las décadas recientes ha dado lugar a una amplia gama de formas de turismo. El turismo rural constituye un ejemplo de esta tendencia, el cual se distingue por un contacto respetuoso con el entorno natural y una interrelación con la población local. Esta forma de turismo surge en un contexto de diversificación productiva...

‣ Observations on Phallocryptus spinosa (Branchiopoda, Anostraca) populations from the high plateaus of Northeastern Algeria

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Phallocryptus spinosa (Thamnocephalidae) is a small primitive crustacean which lives in temporary saline pools of the Palaearctic region called Chott, Sebkha, Garâa or Daya in North Africa. Data on its biology and life history are very scarce despite its ecological importance in wetlands. Four populations living in the Northeastern High Plateaus of Algeria, Garâas Guellif, El-Tarf, Ank Djemel and Sebkha Ez-Zemoul, have been studied in point of view of their morphmetry (13 parameters) and their reproduction. The population of Sebkha Ez-Zemoul, living in higher salinities and in sympatry with Artemia salina was different from the 3 other populations that are close together. Its adults are the largest (21.77 ± 2.34 mm and 23.65 ± 2.36 mm for males and females respectively) and produce more cysts 771.47±8.45 cysts/brood of 293.11±10.41 μm diameter. Associated carcinological fauna and some behavioral traits are also approached.

‣ Evaluación de riesgo ecológico en la aplicación de lodos de plantas de tratamiento de aguas servidas a suelos en la región de la Araucanía.

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Los lodos generados en plantas de tratamiento de aguas servidas contienen materiales orgánicos ricos en nutrientes como nitrógeno (N), fósforo (P) y potasio (K), además de metales y pequeñas cantidades de otros elementos tales como celulosa, ácidos orgánicos. Los lodos pueden ser considerados como residuos o reciclados mediante la incorporación a suelos. Frente a esta situación de disposición de lodos primarios en suelos, se determinó el efecto de dos muestras de lodos (una ya incorporada en suelo y otra fresca) mediante la evaluación de bioensayos de toxicidad en Eisenia foetida durante 14 días, en donde se determinó que las muestras de lodos no presentaban toxicidad y que además existe una independencia entre la concentración y sus efectos en la mortalidad y crecimiento. Sumado a lo anterior, se evaluó las muestras de lodos en base a su contenidos de metales mediante el análisis de riesgo ecológico , en el cual obtenidos los antecedentes referidos a efectos y exposición, se integró la información para estimar el riesgo ecológico para metales pesados, en donde los factores de riesgo para el suelo son como cobre, cadmio, mercurio, níquel y zinc, la estimación del riesgo ecológico en el lodo incluye a todos los metales pesados y finalmente los factores de riesgo para el lodo aplicado en el suelo son todos los metales a excepción de arsénico.; The sludge generated at treatment plants wastewater containing organic materials rich in nutrients such as nitrogen (N)...

‣ Cargas polínicas en Chile y salud pública.

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
La flora urbana de muchas ciudades chilenas posee más elementos exóticos que nativos, adaptadas y difundidas a lo largo de nuestro país, desde las especies nativas originarías a especies introducidas, privilegiando principalmente especies provenientes de Europa, Norte América y Australia (Romero, 2009), Sin embargo varias de estas especies son anemófilas y con antecedentes de inducir alergias, con un aumento de la expresión clínica por sensibilización al polen (Rojas et al, 1999) En Chile, los trabajos orientados a describir cargas polínicas atmosféricas han sido escasos. El primer intento de investigar y medir el polen atmosférico fue realizado por el grupo de Hoffman (1978), este trabajo, se llevó a cabo con un captador gravimétrico, lo que limitaba sus conclusiones al definir cualitativamente el polen presente y su estacionalidad. Posteriormente Rojas et al (1999) determinaron mediante métodos volumétricos la lluvia polínica de Santiago durante tres años.

‣ Distribución y diversidad de Cladóceros (Sididae, Daphniidae, Bosminidae y Chydoridae) en la región de la Araucanía (38º-39ºS)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Los cuerpos de agua de Chile se caracterizan por la presencia de tramas tróficas sencillas (De los Ríos-Escalante, 2003) y un bajo número de especies zooplanctonicas, siendo dominante los copépodos calanoideos, específicamente los géneros Boeckella y Tumeodiaptomus, ocurriendo el proceso contrario con los Cladoceros, los cuales son especies dominantes en el hemisferio norte (Soto & Zúñiga, 1991; Gilloly & Dodson, 2000; Dodson et al 2009).

‣ Regression modeling of field emissions in wheat production using a life cycle assessment (LCA) approach

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Field emissions of Irianian wheat production were investigated. Data were collected from 260 farms from the city of Fereydonshahr in the Esfahan province. Life cycle assessment (LCA) methodology was developed to assess environmental impacts associated with the production of wheat in the studied region. Global warming potential (GWP), eutrophication potential (EP), human toxicity potential (HTP), terrestrial eco-toxicity potential (TEP), oxidant formation potential (OFP) and acidification potential (AP) were calculated as 2620.86 kg CO2 eq.t-1 (tonne of grain), 14.25 kg PO4 -2 eq.t-1, 1111.7 kg 1,4-DCB eq.t-1, 10.59 kg 1,4-DCB eq.t-1, 0.0073 kg ethylene eq.t-1 and 19.07 kg SO2 eq.t-1, respectively. In order to specify a relationship between input materials and field emissions (direct and indirect emission), the Cobb-Douglass production function was applied. The impacts of farm area, N, P2O5, K2O, diesel fuel and biocides were entered as independent variables and different impact categories as dependent variables. RMSE of models for GWP, EP, HTP, TEP, OFP and AP was 0.07, 0.19, 0.17, 0.34, 0.49 and 0.26, respectively. Accordingly with a rise in farm size level, the emissions per tonne of grain produced decreased.

‣ Optimization of degummed Linum usitatissimum methyl ester from methanolysis as a potential resource for diesel engines

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Studies were carried out on the methanolysis of crude and degummed Linum usitatissimum seed oil with methanol for methyl ester synthesis. In this study, response surface methodology was applied in order to optimize the reaction factors for methyl ester synthesis. The present work also studies the experimental conditions such as catalyst concentration, molar ratio (methanol:oil) and reaction time on the conversion of Linum usitatissimum seed oil to methyl esters. The conversion was above 96.2% under the condition of 60 ºC, methanol-oil molar ratio of 8:1, reaction time of 60 minutes and catalyst concentration (catalyst/oil) of 0.6 wt%. The resulting methyl esters (biodiesel) and its diesel blends were characterized for basic fuel properties including density, viscosity, cloud and pour point, flash and fire point, calorific value and acid value. The results show that the enzymatic degummed Linum usitatissimum seed oil used with a phosphorus (phospholipids) level of 9.8 ppm provides an excellent methyl ester yield of over 96.2% and basic fuel properties of these blends are comparable to those of conventional diesel fuel at 20% of methyl esters concentrations.

‣ Optimal Control of PV/Wind/Hydro-Diesel Hybrid Power Generation System for Off-grid Macro Base Transmitter Station Site

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
An operational control system was proposed in order to control and supervise the operations of PV/Wind/Hydro-Diesel hybrid power generation systems at GSM base station sites. The control system was developed in such a way that it coordinates when power should be generated by renewable energy (PV panels, wind turbine and hydro turbine) and when it should be generated by diesel generators. This system is intended to maximize the use of the renewableenergy system while limiting the use of the diesel generator. The diesel generator is utilized only when the demand cannot be met by the renewable energy sources including battery bank. A developed control system was used to study the operations of the hybrid PV/Wind/Hydro-Diesel energy system. The control simulation shows that the developed control system reduces the operational hours of the diesel generator thereby reducing the running cost of the hybrid energy system and pollutant emissions. From the simulation result, the developed control system reduces the operational hours of the diesel generator from 7,106 h yr-1 to 1,786 h yr-1 saving 28,087 L of fuel annually, and thereby preventing about 73,961 kg of CO2 from entering the environment of the studied area. This control system is suitable for use in a more complex hybrid system.

‣ Environmental Impact Assessment of Power Generation Systems at GSM (Global Systems for Mobile Communication) Base Station Site

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Hybrid power systems were used to minimize the environmental impact of power generation at GSM (global systems for mobile communication) base station sites. This paper presents the comparative environmental impact assessment of a diesel gas (DG) and hybrid (PV/wind/hydro/diesel) power system for the base station sites. The assessment was based on theoretical modeling of the power stations using Hybrid Optimization Model for Electric Renewables (HOMER) software. The model was designed to provide an optimal system configuration based on hour-by-hour data for energy availability and demands. Energy source, energy storage and their applicability in terms of performance are discussed. The proposed hybrid (solar, wind & hydro) + DG system was simulated using the model which results in eight different topologies: hybrid (solar, wind & hydro) + DG, hybrid (solar & hydro) + DG, hybrid (wind & hydro) + DG, hydro only + DG, hybrid (solar & wind) + DG, solar only + DG, wind only + DG, DG. From the simulation results, it is shown that a 69% renewable energy penetration in the designed hybrid PV/wind/hydro/diesel system reduces the quantity of different air pollutants relative to the case of a diesel-only system. Details of the comparisons are presented.

‣ Exhaust Gas Simulation of Hydrogen–Ethanol Dual Fuel

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The drawback of lean burn with ethanol is reduced power output. Lean operation of ethanol fuelled engines has additional drawbacks. Lean mixtures are hard to ignite, despite the mixture being above the low fire (point) limit of the fuel. This results in misfire, which increases unburned hydrocarbon emissions, reduces performance and wastes fuel. Hydrogen can be used in conjunction with ethanol provided it is stored separately. Mixing hydrogen with a oxygenated hydrocarbon fuel such as ethanol reduces all of these drawbacks. The low ignition energy limit of hydrogen combined with a high burning speed makes the hydrogen-ethanol mixture easier to ignite, reducing misfire and thereby improving emissions, performance and fuel economy. The current study involved generating simulation software that provides the mole fraction of each of the exhaust species when hydrogen is combusted with ethanol. The proportion of hydrogen in the hydrogen–ethanol blend affecting the mole fraction of the exhaust species is also simulated. The program code developed gave reasonably good results for the present hydrogen-ethanol dual fuel. At low and high percentages of hydrogen, and during transition between ethanol and hydrogen, the model predictions are not very clear. The best results were obtained for a combination of 80% hydrogen and 20% ethanol by volume.

‣ Comparison Between Measured Mean Monthly Solar Insolation Data and Estimates from Swera Database for Salta City (Northwestern Argentina)

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The lack of measured data for global solar insolation in the Argentine Northwest (ANW) was supplied using free-access databases available on the Internet. For Salta Capital metropolitan region, measured monthly mean global solar insolation and estimated monthly values from SWERA, SoDa and SSE databases are compared. The objective was to determine the degree of correlation of each database with measured values and the origin in found differences. SWERA data happened to be the best correlation, with the measured data (average RMSE% = 14%). The other databases have errors above 24 %, this being attributed to larger satellite grid cells. A linear model, developed using MLR, is presented. It offers better estimates than the databases (RMSE% of 6%), but only applies to Salta Capital.

‣ The Potential of a Mix of Renewable (PV/Wind) Energy System for an Information and Communication Technology (ICT) Centre in a Rural Environment

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
The design is presented of an optimized mix of renewable (PV/Wind) energy system for an Information and Communication Technology (ICT) Center in Rural environments in Kauru (Kaduna State), Northern Nigeria with a daily load of 24 kwh d-1. Solar radiation and wind speed for the design of the system were obtained from the NASA Surface Meteorology and solar energy website at a location of 10° 39’ N latitude and 8° 09’ E longitude, with annual average solar radiation of 5.64 kWh m-2d-1 and annual average wind speed of 2.5 m s-1. The patterns of load consumption by the ICT Centre were studied and suitably modeled for optimization using the National Renewable Energy Laboratory’s Hybrid Optimization Model for Electric Renewables (HOMER) software. The proposed PV/Wind system was simulated using the model resulting in two different topologies: PV/Wind and PV only. From the simulation results, the PV/Wind system solution was considered to be the best energy option (solution) for the ICT Center. This optimization study indicates that energy requirements to provide electricity for an ICT center in Kauru with the least cost could be accomplished by a combination of 8 kW PV array, 1 unit 7.5 kW BWC Excel-R wind turbine...

‣ Assessment of Power Coefficient of an Offline Wind Turbine Generator System

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
In this paper, we present the design of an estimator for the assessment of the power coefficient of an offline wind turbine in a variable wind turbine generator system (WTGS) using a direct drive permanent magnet synchronous generator. It is shown that the estimator is supplying accurate estimates of the power coefficient. A further advantage of the estimator design presented is that it can be easily connected to WTGS where different types of generators and turbines are employed. The simulation results are presented using a graphic user interface and MATLAB Simulink.

‣ Health impacts in South-central Chile due to misuse of wood-burning stoves

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
After the episode that occurred in London in December of 1952 in which more than four thousand people died as a result of acute exposure to atmospheric contaminants (particulate matter and sulfur dioxide, principally), there are no doubts that air quality has an important effect on the health of the population. Exposure to air and the intake of air and its components are permanent and obligatory. “We can choose the water we drink and the food that we eat, but we cannot choose the air that we breathe.” Given that a person inhales between 13 and 15 m3 (between 13,000 or 15,000 liters), it is understood that humans are highly vulnerable to atmospheric pollution. As is shown in Fig. 1, in many cities in the central and southern parts of Chile, (Rancagua, Talca, Chillán, Gran Concepción, Los Angeles, Temuco, Osorno, Valdivia and Coyhaique) the problem of atmospheric pollution from particulate matter (PM) exists [Ministerio del Medio Ambiente, 2011]. This agent is principally emitted by wood stoves and ovens that use firewood, due to the bad practices or misuse of these devices, such as the burning of wet wood (humidity over 25%) in articles of precarious technology, that are additionally operated in an undesirable manner (closure of air intakes). Also...

‣ The Impact of Particle Size on the Dilute Acid Hydrolysis of Giant Reed Biomass

Fonte: Universidade Católica de Temuco Publicador: Universidade Católica de Temuco
Tipo: Artículo de Revista
Português
Heterogeneous reaction systems, such as the dilute acid hydrolysis of lignocellulosic biomass for the recovery of hemicelluloses, are typically dependent of particle size which is considered as one of the most important variables that affect process yield and global production costs. In this work, the effect of feedstock particle size on dilute acid hydrolysis is studied using Giant Reed (Arundo donax), a Mediterranean energy crop with a high potential for the production of bioenergy and added-value products, as a model feedstock. Five different particle sizes (ranging between < 0.25 to 4 mm) were studied using previously optimized dilute hydrolysis conditions. Both the hydrolysates and the residual solids were chemically characterized. Hydrolysates always contained more than 32 g/L of total sugars (from which 93% are pentoses) and all the residual solids contained more than 50% glucan per dry weight of processed solids that corresponds to complete recovery of glucan in the solid phase. These results clearly show a selective hydrolysis of the hemicellulose regardless of the particle size fractions assayed. Actually, no statistically significant changes between fractions were identified, which is a further advantage for this raw material...