Time filter

Source Type

Kaschel H.,University of Santiago de Chile | Cordero S.,University of Technology of Chile | Costoya E.,Colegio de Ingenieros de Chile
2016 IEEE International Conference on Automatica, ICA-ACCA 2016 | Year: 2016

On this paper, worldwide Digital TV Standards (TDT) are reviewed as well as the approach and needs for point to area propagation modeling currently used worldwide to predict TDT broadcasting coverage. One of the models currently used for coverage calculations, the deterministic ITM (Irregular Terrain Model - Longley-Rice) based on Technical Note 101 Vol-I and II, as well as the empirical ITU-R-P1546-5 Model will be studied and analyzed. The modeling of TVD coverage of existing TVD stations will be performed with both Models and compared with actual coverage of exiting field strength surveys, performed by broadcast operators under the ITU recommendations specs. Finally, conclusions will be drawn on the pros and cons of each Model. © 2016 IEEE.


Gonzalez-Burboa A.L.,University of Concepción | Cossio C.A.A.,University of Technology of Chile
Revista Cubana de Educacion Medica Superior | Year: 2016

Introduction: In the context of the process for the implementation of the Model by Competences, to which University of Concepción has joined, we considered relevant the follow-up and assessment of the educative practices performed from a perspective that permitted verifying its adaptation to the context in which they were implemented. Objective: Describe the first year students majoring in Obstetrics and Puericulture at University of Concepción's perception about the implementation of the Generic Macro-competences. Methods: Evaluative research of quantitative and qualitative approach. A self-report instrument containing 22 Likert items and other 3 open questions were applied to 86 women and 7 men. For the quantitative analysis of the data, the statistical software SPSS 19 was used; for the qualitative analysis, the software Atlas.ti 6.2 was used. Results: The qualitative analysis showed a positive evaluation of the methodology and contents treated in the implementation. The quantitative analysis showed high approval in all the dimensions, with Content outstanding (n=85; 91.4 %). Conclusions: The students assess the Generic Macro-competences as an aspect for their professional and personal development. However, a context-adapted implementation is required. © 2016, Editorial Ciencias Medicas. All rights reserved.


Wilen J.E.,University of California at Davis | Cancino J.,University of Technology of Chile | Uchida H.,University of Rhode Island
Review of Environmental Economics and Policy | Year: 2012

The most recent stage in the evolution of fisheries management institutions has been the adoption of so-called rights-based management schemes that grant secure rights of access to users so they are not forced to compete wastefully under open access conditions. The most common rights-based system is the individual transferable quota that grants fishermen rights to a share of a biologically determined total harvest. Another rights-based system is the harvester cooperative that grants access rights to a group. Unlike these species-based rights systems, territorial use rights fisheries, known as TURFs, are place-based, allocating some or all resources within a designated coastal zone to one or more agents. This article discusses the deficiencies of species-based systems and the advantages of place-based systems and reviews experience with TURFs in Japan and Chile. We argue that the success of TURFs depends not only on their physical design and placement, but also on the governing institutions that make internal resource use decisions. In most applications, TURFs are governed by harvester cooperatives that generate value by mitigating common property incentives and resolving internal coordination problems not otherwise addressed by species-based instruments. (JEL: Q2, Q22, Q28) © The Author 2012. Published by Oxford University Press on behalf of the Association of Environmental and Resource Economists. All rights reserved.


Tapia J.,University of Talca | Vargas-Chacoff L.,Austral University of Chile | Bertran C.,Austral University of Chile | Pena-Cortes F.,Catholic University of Temuco | And 4 more authors.
Environmental Monitoring and Assessment | Year: 2012

The concentrations of cadmium, lead, manganese and zinc were determined in the fish species Micropogonias manni captured in Budi Lake, Araucanía Region (Chile). The measurements were made by atomic absorption spectroscopy, and the analysis considered the sex, weight and size of the species; the representative samples were taken from the liver and muscle tissue. The method was validated using certified reference material (DOLT-1). The ranges of concentrations found in the muscle tissue were: Cd, not determinate (n.d.)-0.26; Pb, n.d.-1.88; Mn, 0.02-12.17 and Zn, 0.48-39.04 mg kg -1 (dry weight). The concentrations in muscle tissue were generally lower than those found in the liver. With respect to the average concentrations recorded for each metal in the edible part of the fish (muscle tissue), it was found that the levels of Cd, Pb, Mn and Zn are within the ranges published by other authors in similar works and below the maximum concentration limits permitted by current legislation (FAO/WHO 2004; EU 2001) and do not constitute a health hazard for consumers of this species. The results were subjected to statistical analysis to evaluate the correlations between the content of the various metals and the sex, weight and size of each sample. © Springer Science+Business Media B.V. 2011.


Aquatic re-circulation systems (SAR) are being used more and more in agriculture, especially in the north of Chile where the environment conditions are suitable for breeding in SAR (aquatic re-circulation system) of species such as Bonito (Sarda chiliensis chiliensis), whose embryo or larvae origins are unknown, which complicates the evaluation of a technical and economical possibility of developing its breeding in SAR. Due to this, bases for its breeding were determined in January 2013, for 45 days. The characterized embryo periods were 31 in 71, 83 hours, defined in 5 stages: Morula, Blastula, Gastrula, Neurulation and Metamery. From the larvae development 35 periods in 519 hours were observed, a pre-juvenile stage observed at 591 hours and a juvenile one. The eggs were translucent of a telolecitic type of a slow growing in relation to Sarda sarda and Sarda ch. lineolata, since it took them almost three days to hatch. The surviving and hatching rates were high (86,316-9,808% and 89,596-11,683% respectively), so the conditions for their development would be appropriate. Meanwhile, the larvae presented more similarities with Sarda sarda in the first periods of development. The crucial period was between the 81 and 89 hours of life, when the oily drop was re-absorbed; besides, this was a distinguishing feature with the other two species because it was the only one that presented just one oily drop in the larvae period. The possibility of a Sarda ch. chiliensis hatchery is inferred, due to the similarities with Sarda sarda, and because of the success obtained in this breeding. From the morphometric characters, future monitoring is suggested, the ones that represent the most variables in the stages of development such as length and height of the head, and length and height of the eye. © 2014, Postgraduate Medical Institute. All rights reserved.


Uribe E.,University of La Serena | Miranda M.,University of La Serena | Vega-Galvez A.,University of La Serena | Quispe I.,University of La Serena | And 4 more authors.
Food and Bioprocess Technology | Year: 2011

Mathematical modelling was used to study the effect of process temperature on moisture and salt mass transfer during osmotic dehydration (OD) of jumbo squid with 6% (w v -1) NaCl at 75, 85 and 95 °C. The diffusion coefficients for moisture and salt increased with temperature. Based on an Arrhenius-type equation, activation energy values of 62.45 kJ mol -1 and 52.14 kJ mol -1 for moisture and salt, respectively, were estimated. Simulations of mass transfer for both components were performed according to Newton, Henderson and Pabis, Page, Weibull and logarithmic mathematical expressions. The influence of drying temperature on the kinetic parameters was also studied. Based on statistical tests, the Weibull and logarithmic models were the most suitable to describe the mass transfer phenomena during OD of jumbo squid. © 2010 Springer Science+Business Media,LLC.


Gonzalez C.M.,University of Technology of Chile | Pizarro-Guerra G.,University of Technology of Chile | Droguett F.,University of Technology of Chile | Sarabia M.,University of Chile
Biochimica et Biophysica Acta - Biomembranes | Year: 2015

Abstract Organic thin film deposition presents a multiplicity of challenges. Most notably, layer thickness control, homogeneity and subsequent characterization have been not cleared yet. Phospholipid bilayers are frequently used to model cell membranes. Bilayers can be disrupted by changes in mechanical stress, pH and temperature. The strategy presented in this article is based on thermal study of 1,2-dipalmitoyl-sn-glycero-3-phosphocholine (DPPC) through analysis of slight changes in material thickness. The sample was prepared by depositing X- or Y-type DPPC bilayers using Langmuir-Blodgett technique over silicon wafer. Thus, molecular inclination degree, mobility and stability of phases and their respective phase transitions were observed and analyzed through ellipsometric techniques during heating cycles and corroborated by Grazing Incidence X-ray Diffraction and Atomic Force Microcopy measurements. DPPC functional group vibrations were detected by Raman spectra analysis. Scanning Electron Microscope with Field Emission gun (FE-SEM) and conventional SEM micrographs were also used to characterize sample morphology, demonstrating that homogenous bilayer formations coexist with some vesicles or micelles at surface level. Contact angle measurements corroborate DPPC surface wettability, which is mainly related to surface treatment methods of silicon wafer used to create either hydrophilic or hydrophobic nature regarding the substrate surface. Also, shifting and intensity changes of certain functional groups into Raman spectra confirm water presence between DPPC layers. Signal analysis detects certain interdigitation between aliphatic chains. These studies correspond to the base of future biosensors based on proteins or antimicrobial peptides stabilized into phospholipid bilayers over thin hydrogel films as moist scaffold. © 2015 Elsevier B.V.


Barragan C.C.,Major University | Huidobro C.B.,Diego Portales University | Esquivel M.P.,University of Technology of Chile
Proceedings - International Conference of the Chilean Computer Science Society, SCCC | Year: 2016

The world of mobile devices which have the quality to stay connected to the web is going through a exponential growth, but in parallel with this event, appears the threats with the developing of an equal magnitude, which are segmented primarily by the characteristics of the target device, therefore, as an final user is very difficult to know how exposed it is to use or purchase one of these devices. Those, the present work aims at obtain and understand a mathematical formula to helps determine the probability that a mobile device should be infected, considering the threats that surround it by operating system and their version. This research is based on numerical data obtained through extensive investigation, the quantity of devices with Android operating system and their respective versions, to contrast with the amount of malware developed for each version, to thereby obtain a probability of recognition the device to be tested. © 2015 IEEE.


Correa-Llanten D.N.,Fundacion Cientifica y Cultural Biociencia | Munoz-Ibacache S.A.,Fundacion Cientifica y Cultural Biociencia | Munoz-Ibacache S.A.,University of Technology of Chile | Castro M.E.,Fundacion Cientifica y Cultural Biociencia | And 4 more authors.
Microbial Cell Factories | Year: 2013

Background: The use of microorganisms in the synthesis of nanoparticles emerges as an eco-friendly and exciting approach, for production of nanoparticles due to its low energy requirement, environmental compatibility, reduced costs of manufacture, scalability, and nanoparticle stabilization compared with the chemical synthesis.Results: The production of gold nanoparticles by the thermophilic bacterium Geobacillus sp. strain ID17 is reported in this study. Cells exposed to Au3+ turned from colourless into an intense purple colour. This change of colour indicates the accumulation of intracellular gold nanoparticles. Elemental analysis of particles composition was verified using TEM and EDX analysis. The intracellular localization and particles size were verified by TEM showing two different types of particles of predominant quasi-hexagonal shape with size ranging from 5-50 nm. The mayority of them were between 10-20 nm in size. FT-IR was utilized to characterize the chemical surface of gold nanoparticles. This assay supports the idea of a protein type of compound on the surface of biosynthesized gold nanoparticles. Reductase activity involved in the synthesis of gold nanoparticles has been previously reported to be present in others microorganisms. This reduction using NADH as substrate was tested in ID17. Crude extracts of the microorganism could catalyze the NADH-dependent Au3+ reduction.Conclusions: Our results strongly suggest that the biosynthesis of gold nanoparticles by ID17 is mediated by enzymes and NADH as a cofactor for this biological transformation. © 2013 Correa-Llantén et al.; licensee BioMed Central Ltd.


Banda P.,University of Technology of Chile
Life In:formation: On Responsive Information and Variations in Architecture - Proceedings of the 30th Annual Conference of the Association for Computer Aided Design in Architecture, ACADIA 2010 | Year: 2010

The following paper deals with a performance-driven morphogenetic design task to improve the conditions of room acoustics, using as a case study the material laboratory of the School of Architecture at Federico Santa Maria University of Technology. Combining contemporary Parametric Modeling techniques and a Performance- Based approach, an automatic generative system was produced. This system generated a modular acoustic ceiling based on Helmholtz Resonators. To satisfy sound absorption requirements, acoustic knowledge was embedded within the system. It iterates through a series of design sub-tasks from Acoustic Simulation to Digital Fabrication, searching for a suitable design solution. The internal algorithmic complexity of the design process has been explored through this case study. Although it is focused on an acoustic component, the proposed design methodology can influence other experiences in Parametric Design.

Loading University of Technology of Chile collaborators
Loading University of Technology of Chile collaborators