19 results on '"Ureta, Gabriel"'
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2. Geomorphological, morphometric, and spatial distribution analysis of the scoria cones in the Negros de Aras monogenetic volcanic field, northern Chile
- Author
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Aguilera, Mauricio, Ureta, Gabriel, Grosse, Pablo, Németh, Károly, Aguilera, Felipe, and Vilches, Matias
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- 2022
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3. Effusion rate estimation based on solidified lava flows: Implications for volcanic hazard assessment in the Negros de Aras monogenetic volcanic field, northern Chile
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Vilches, Matias, Ureta, Gabriel, Grosse, Pablo, Németh, Károly, Aguilera, Felipe, and Aguilera, Mauricio
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- 2022
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4. Holocene collapse of Socompa volcano and pre- and post-collapse growth rates constrained by multi-system geochronology
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Grosse, Pablo, Danišík, Martin, Apaza, Facundo D., Guzmán, Silvina R., Lahitte, Pierre, Quidelleur, Xavier, Self, Stephen, Siebe, Claus, van Wyk de Vries, Benjamin, Ureta, Gabriel, Guillong, Marcel, De Rosa, Rosanna, Le Roux, Petrus, Wotzlaw, Jörn-Frederik, and Bachmann, Olivier
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- 2022
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5. Evolution of a magmatic to a phreatomagmatic volcanic system: The birth of a monogenetic volcanic field, Tilocálar volcanoes, northern Chile
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Ureta, Gabriel, Németh, Károly, Aguilera, Felipe, Kósik, Szabolcs, González, Rodrigo, Menzies, Andrew, González, Cristóbal, and James, Diego
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- 2021
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6. Advances in scientific understanding of the Central Volcanic Zone of the Andes: a review of contributing factors
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Aguilera, Felipe, Apaza, Fredy, Del Carpio, José, Grosse, Pablo, Jiménez, Néstor, Ureta, Gabriel, Inostroza, Manuel, Báez, Walter, Layana, Susana, Gonzalez, Cristóbal, Rivera, Marco, Ortega, Mayra, Gonzalez, Rodrigo, and Iriarte, Rodrigo
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- 2022
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7. Deposition of metals and metalloids in the fumarolic fields of Guallatiri and Lastarria volcanoes, northern Chile
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Inostroza, Manuel, Aguilera, Felipe, Menzies, Andrew, Layana, Susana, González, Cristóbal, Ureta, Gabriel, Sepúlveda, José, Scheller, Samuel, Böehm, Stephan, Barraza, María, Tagle, Roald, and Patzschke, Max
- Published
- 2020
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8. Control interfaces for wheelchair mobility.
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Felipe, Marely del Rosario Cruz, Pinargote-Ortega, Maricela, Ureta, Gabriel Primitivo Demera, Molina, Marcelo Andrés Alcívar, and Morales, José Andrés García
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ELECTRIC wheelchairs ,ELECTRIC motors ,MUSCULAR dystrophy ,WHEELCHAIRS ,STEPPING motors ,CELL phones ,ELECTRONIC systems - Abstract
Technology allows the development of products that help improve the quality of life of people with disabilities. In the Inclusion, Social Equity, and Gender Unit of the Technical University of Manabí, there are three registered students with muscular dystrophy, who need to move autonomously. The objective of this research was to evaluate interfaces for the mobility of a wheelchair. The experimental method was applied and observation was used to identify the requirements based on the needs of students with muscular dystrophy within the university and at home and establish the mechanical, electronic, and interface components. From the evaluations of the interfaces, a prototype was developed at a lower cost than those existing in the current market and with the transport facilities of a traditional wheelchair. A mechanical and electronic system was designed with an Arduino UNO board, Bluetooth module, cell phone microphone, step electric motors, motor control drivers, and batteries, among other equipment, and for this, an application with an Android Studio interface was developed. The motors produce the appropriate movements using a voice command module, so the person with muscular dystrophy can go in any direction they want: forward, backward, left, right, or stop. It is concluded that the voice command interface is the one with the least margin of error for people with muscular dystrophy because they do not have the strength to handle a joystick or press buttons. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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9. A window on mantle-derived magmas within the Central Andes: eruption style transitions at Cerro Overo maar and La Albóndiga lava dome, northern Chile
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Ureta, Gabriel, Németh, Károly, Aguilera, Felipe, Zimmer, Martin, and Menzies, Andrew
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- 2021
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10. Optimal control of fermentation processes
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Carillo-Ureta, Gabriel Eduardo
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670 ,TA Engineering (General). Civil engineering (General) - Abstract
The general purpose of this thesis is to focus on a particular industrial process (from the beer industry) which serves as a guidance example for optimal control using different algorithms/methods. At the same time, the aim is to demonstrate the capabilities/features of MATLAB and SIMULINK as tools used in programming algorithms and simulation for optimal control of non linear systems. The thesis shows how to approach an optimisation problem with different techniques and to compare them on the same basis. The main reasons for carrying out research on a beer fermentation process can be summarised as follows: this kind of industry represents an up-to-date example of industrial processes in general, the need to compare and evaluate optimisation methods (well established and "modern") on similar circumstances using the sanle process model and finally, give a good foundation for the control engineer to followup this work with different optimisation techniques and/or any other industrial process. The fundamental features of the methods used involve the viability of known previously tested algorithms for optimal control of beer processes with high nonlinearity and constraints; thus testing the flexibility of some of the known MA TLAB Toolboxes for the optimal control of a particular simulated mathematical model. An important aspect of the experimentation that has been carried out, is the creation of a simulated model of a selected beer process by means of including the mathematical equations, parameters and initial conditions into an s-function block. This SIMULINK model also incorporates the particular objective function that can be calculated directly after the simulation of the process for a particular input temperature profile. Together with the use of some available MA TLAB functions for the formulation of particular optimal control techniques, this facilitates the creation of program routines that can be interfaced with the simulated process. The final results using different optimisation methods such as: the gradient method in function space, DIS OPE algorithm, Genetic Algorithms and Sequential Quadratic programming; show substantial improvement in the perfomance index obtained. The optimised temperature profiles found can be implemented for industrial application to provide a maximised ethanol production under particular restrictions, i.e. final byproducts concentration, contamination risk and brisk changes in temperature.
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- 2003
11. Resistivity electrical model of the Cerro Overo maar in the Central Andes
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Alarcon, Noemi, Diaz, Daniel, Oliveros, Verónica, and Ureta, Gabriel
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The Cerro Overo volcano is a monogenetic center of the Holocene age located in the north of Chile in the Central Volcanic Zone of the Andes, which is part of the Altiplano-Puna Volcanic Complex. Based on petrological and geochemical data, it has been classified by Ureta et al. (2021) as a phreatomagmatic explosion crater generating a maar-type structure with a diameter of 600 m. Our interest lies in the morphological difference between Cerro Overo with the nearby eruptive centers. Its current morphology is inferred from a phreatomagmatic eruption during its magma ascent. The initial hypothesis is that the electrical resistivity model would allow the identification of fluids and typical structures of magma-water explosions. Broadband magnetotelluric (MT) soundings were carried out in the surroundings of the volcano, managing to identify the distribution of low-resistivity structures up to the first kilometers, becoming more resistive with depth. This structure would correspond to the diatreme as a remnant of the eruption percolated by fluids in its upper part., The 28th IUGG General Assembly (IUGG2023) (Berlin 2023)
- Published
- 2023
12. Herramienta para el Análisis de la Calidad de Servicio de Una Red Simple
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Felipe, Marely del Rosario Cruz, Ortega, Maricela Pinargote, and Ureta, Gabriel Demera
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El crecimiento de las redes y la incorporación de nuevos servicios a las mismas, hace necesario implementar técnicas de calidad de servicio (Quality of Service, QoS) para satisfacer las necesidades siempre crecientes de los usuarios informáticos. A su vez esto trae aparejado la necesidad de implementar mecanismos de evaluación de la QoS dentro de ellos uno de los más efectivos la simulación, para así poder predecir el comportamiento de las redes y aparejado a esto tomar todas las medidas necesarias para su correcto funcionamiento. Es por esto que la presente investigación tiene como objetivo elaborar una herramienta para la simulación de una red simple, la cual permitirá calcular los parámetros de QoS. Esta herramienta se encuentra sustentada en un modelo de una red simple, desarrollado para la simulación y muestra resultados de la misma, arrojando la comparación con resultados obtenidos a partir de un modelo analítico de una red simple lo cual permite corroborar la efectividad de la herramienta desarrollada. Palabras claves: Calidad de servicio, red, herramienta, modelo.
- Published
- 2018
13. Propuesta de Sitio Web Accesible para Personas con Discapacidad Visual
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Ortega, Maricela Pinargote, Felipe, Marely del Rosario Cruz, and Ureta, Gabriel Demera
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World Wide Web ,Screen reader ,Background color ,Visual impairment ,Technical university ,medicine ,medicine.symptom ,Psychology ,Inclusion (education) ,Web accessibility ,Unit (housing) ,Social equality - Abstract
The Technical University of Manabí (UTM) (Ecuador) provides support to people with priority attention, currently has registered: 36 students, 3 teachers and 8 employees with visual impairment. The present work proposes to transform the website of the Unit for Inclusion, Social Equity and Gender (UIESG) into accessible based on accessibility standards; where the community in general and university with visual impairment enjoy in equal conditions different alternatives: configure the screen with increasing or decreasing the size of the text, activate voice, use screen reader programs that read the alternative text of the images And correctly describe the content, and change the background color in contrast to the text; contributing to the inclusive progress of this university.Keywords: Ecuador, university, visual impairment, website, accessibility.
- Published
- 2018
14. PRELIMINARY ASSESSMENT OF THE ORIGIN AND EVOLUTION OF FLUIDS DISCHARGED FROM GUALLATIRI VOLCANO SAMPLING PLAN RESULTS AND DISCUSSIONS
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Inostroza, Manuel, Aguilera, Felipe, Tassi, Franco, Capecchiacci, Francesco, Sepulveda, Jose, González, Cristóbal, Ureta, Gabriel, Layana, Susana, and Capasso, Giorgio
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- 2018
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15. An Overview of the Mafic and Felsic Monogenetic Neogene to Quaternary Volcanism in the Central Andes, Northern Chile (18-28°Lat.S)
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Ureta, Gabriel, Sepúlveda, José Pablo, González, Rodrigo, Scheinost, Alexander, Torres, Ivana, Aguilera, Mauricio, Vilches, Matias, Németh, Károly, and Aguilera, Felipe
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Science / Earth Sciences - Abstract
Monogenetic volcanism produces small eruptive volumes with short eruption history, different chemical compositions, and relatively simple conduit. The Central Volcanic Zone of the Andes is internationally known as a natural laboratory to study volcanism, where mafic and felsic products are present. In this contribution, the spectrum of architectures, range of eruptive styles, lithological features, and different magmatic processes of the mafic and felsic monogenetic Neogene to Quaternary volcanoes from the Central Volcanic Zone of the Andes in northern Chile (18°S-28°S) are described. The major volcanic activity occurred during the Pleistocene, where the most abundant activity corresponds to effusive and Strombolian eruptions. This volcanism is characterized by external (e.g., magma reservoirs or groundwater availability) and internal (e.g., magma ascent rate or interaction en-route to the surface) conditions, which determine the changes in eruptive style, lithofacies, and magmatic processes involved in the formation of monogenetic volcanoes.
- Published
- 2018
16. Transition from small-volume ephemeral lava emission to explosive hydrovolcanism: The case of Cerro Tujle maar, northern Chile.
- Author
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Ureta, Gabriel, Aguilera, Felipe, Németh, Károly, Inostroza, Manuel, González, Cristóbal, Zimmer, Martin, and Menzies, Andrew
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CLASTIC rocks , *FELSIC rocks , *LAVA , *LAVA flows , *WATER table , *BRECCIA - Abstract
Cerro Tujle is an isolated Quaternary maar located 21 km south-east of the Salar de Atacama basin. It is situated at 3,554 m a.s.l., on the top of the Cordón de Tujle ridge forming a north-south striking morphological element in the Central Volcanic Zone of the Andes, in northern Chile. The material erupted at Cerro Tujle lies over the Tucúcaro Ignimbrite (3.2 ± 0.3 Ma), covering the whole area. The origin of the magma source, as well as the evolution and control of the volcanic eruptive styles, were determined by fieldwork, stratigraphic, morphometric, textural (density and vesicularity), petrographic, and geochemical analyses. The Cerro Tujle maar features an elliptical crater (333 × 279 m wide in east-west and north-south directions, respectively) surrounded by lava flow and tephra deposits. The total Dense Rock Equivalent volume of the products was calculated in 1.53 × 105 m3, and mainly correspond to andesites (58.62–59.80 wt% of SiO 2). The lava flow can be categorized in at least two types: i) brown-red and green-to-gray andesites located on the north-northwestern flank of the crater, and ii) black andesites with felsic rock clasts distributed around the crater underlying the other lavas. In contrast, the pyroclastic deposit displays breccias of juvenile pyroclasts with xenoliths of rhyolitic composition. These felsic clasts suggest magma assimilation with a shallow magma reservoir during a relatively fast ascent of the magma. This is evidenced by disequilibrium textures in mineral levels, such as reaction rim, and skeletal and sieve textures of the phenocrysts. The field evidence and results of the different analyses suggest a change in the eruptive style from effusive to explosive. This transition is associated with a decrease of the magma flux and a withdrawal of magma below the groundwater table, which has produced a phreatomagmatic eruption by magma-water interaction. • The field relationships between lava flow emission and pyroclastic surge deposit. • Changing eruptive styles in intermediate volcanism. • The hydromagmatic explosive eruptions are not uncommon in the Altiplano-Puna region, northern Chile. [ABSTRACT FROM AUTHOR]
- Published
- 2020
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17. Features That Favor the Prediction of the Emplacement Location of Maar Volcanoes: A Case Study in the Central Andes, Northern Chile.
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Ureta, Gabriel, Németh, Károly, Aguilera, Felipe, and González, Rodrigo
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VOLCANOES , *VOLCANIC hazard analysis , *VOLCANIC activity prediction , *ENDORHEIC lakes , *FORECASTING , *AQUIFERS , *VOLCANOLOGY - Abstract
Maar volcanoes are monogenetic landforms whose craters cut below the pre-eruptive surface and are surrounded by a tephra ring. Both the maar crater and the surrounding tephra rim deposits are typically formed due to magma–water explosive interactions. Northern Chile is located in the Central Volcanic Zone of the Andes where, in literature, 14 maars have been recognized as parasite (6) and individual (8) volcanoes. Amongst these individual maars, 3 of them, namely the Tilocálar Sur, Cerro Tujle, and Cerro Overo volcanoes, are not related to calderas and were emplaced <1 Ma ago by magmatic explosive-effusive and phreatomagmatic eruptions. Based on the evolution and control of the volcanic eruptive styles of these three maars, which have been determined in previous research through fieldwork, stratigraphic, morphometric, textural (density and vesicularity), petrographic, and geochemical analyses, a set of key features that favor a prediction of the emplacement location of maar volcanoes in Central Andes, northern Chile are proposed. The set of features that permit and favor the growth mechanisms for maar formations corresponds to (i) a compressive tectonic setting (e.g., ridge structures), (ii) groundwater recharge (e.g., snowmelt and seasonal rainfall), (iii) the lithological setting (e.g., layers of low permeability), (iv) the presence of aquifer and/or endorheic basins (e.g., lakes or salars), and (v) a period of stress relaxation that permits magma ascent to the surface in volcanically active areas. Considering these characteristics, it is possible to identify places where phreatomagmatic eruption can occur. If the magma ascent flux is lower than the groundwater flux, this can lead to a phreatomagmatic eruption because of groundwater coming into contact with the magma. These eruptive features evidence internal—and external—factors that play an essential role in the transition from explosive-effusive magmatic to phreatomagmatic volcanic eruption styles during the same eruptive period that is one of the biggest challenges in volcanic hazard evaluations. Although, in this contribution, a set of features that permit and favor the growth mechanisms for a prediction of the emplacement location of maars in northern Chile is proposed, these considerations could also be applied to identify potential locations in other parts of the world where magma–water interaction eruption could occur. Therefore, this approach could be useful in the prediction of hydromagmatic volcanic eruptions and, thus, in mitigating the impact of volcanic hazard for the inhabitants of the surrounding areas. [ABSTRACT FROM AUTHOR]
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- 2020
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18. First Measurements of Gas Flux with a Low-Cost Smartphone Sensor-Based UV Camera on the Volcanoes of Northern Chile.
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Aguilera, Felipe, Layana, Susana, Rojas, Felipe, Arratia, Pilar, Wilkes, Thomas C., González, Cristóbal, Inostroza, Manuel, McGonigle, Andrew J.S., Pering, Tom D., and Ureta, Gabriel
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VOLCANOES ,IMAGE stabilization ,VOLCANIC plumes ,LIGHT absorption ,VOLCANIC gases ,CAMERAS ,VOLCANIC activity prediction ,GROUND reaction forces (Biomechanics) - Abstract
UV cameras have been used for over a decade in order to remotely sense SO
2 emission rates from active volcanoes, and to thereby enhance our understanding of processes related to active and passive degassing. Whilst SO2 column density retrievals can be more accurate/sophisticated using alternative techniques (e.g., Differential Optical Absorption Spectrometer (DOAS), Correlation Spectrometer (COSPEC)), due to their higher spectral resolutions, UV cameras provide the advantage of high time-resolution emission rates, a much greater spatial resolution, and the ability to simultaneously retrieve plume speeds. Nevertheless, the relatively high costs have limited their uptake to a limited number of research groups and volcanic observatories across the planet. One recent intervention in this regard has been the introduction of the PiCam UV camera, which has considerably lowered instrumental cost. Here we present the first data obtained with the PiCam system from seven persistently degassing volcanoes in northern Chile, demonstrating robust field operation in challenging conditions and over an extended period of time, hence adding credence to the potential of these units for more widespread dissemination to the international volcanic gas measurement community. Small and weak plumes, as well as strongly degassing plumes were measured at distances ranging 0.6–10.8 km from the sources, resulting in a wide range of SO2 emission rates, varying from 3.8 ± 1.8 to 361 ± 31.6 td−1 . Our acquired data are discussed with reference to previously reported emission rates from other ground-based remotely sensed techniques at the same volcanoes, in particular considering: resolution of single plume emissions in multi-plume volcanoes, light dilution, plume geometry, seasonal effects, and the applied plume speed measurement methodology. The main internal/external factors that influence positive/negative PiCam measurements include camera shake, light dilution, and the performance of the OpenCV and control points post processing methods. A simple reprocessing method is presented in order to correct the camera shake. Finally, volcanoes were separated into two distinct groups: low and moderate SO2 emission rates systems. These groups correlate positively with their volcanological characteristics, especially with the fluid compositions from fumaroles. [ABSTRACT FROM AUTHOR]- Published
- 2020
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19. Characterization, origin, and evolution of one of the most eroded mafic monogenetic fields within the central Andes: The case of El País lava flow field, northern Chile.
- Author
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Torres, Ivana, Németh, Károly, Ureta, Gabriel, and Aguilera, Felipe
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LAVA flows , *VOLCANIC fields , *BRECCIA , *SURFACE texture , *ANALYTICAL geochemistry , *VOLCANOES - Abstract
El País is a monogenetic lava flow field located 16 km southeast of Peine town in the Altiplano-Puna area, Antofagasta region, Chile. El País is a monogenetic lava flow field located 16 km southeast of Peine town in the Altiplano-Puna area, Antofagasta region, Chile. El País is composed by lava flows of small-to-moderate volumes, which are fed from individual point sources unassociated with a central volcano of large-volume (stratovolcano) typical of the Andean arc. This lava flow field was emplaced in an area dominated by thin-skinned deformation under a compressive tectonic regime, where multiple volcanic centers (monogenetic and polygenetic volcanoes) have been developed. The volumetric and chemical evolutions were determined by fieldwork, stratigraphic, morphometric, textural (density and vesicularity), petrographic, and geochemical analyses. El País can be divided into three principal mafic lava flows such as Northern-, Main-, and Western-lava flows, which display an E-W orientation. Besides, at least eight ephemeral vents were identified as small erosion remnants of lava emitting point-sources. The identified vents are principally aligned in an ENE-WSW direction, east of the Main lava flow. It is inferred that El País was emplaced near-simultaneously above two ignimbrite sheets: Tucúcaro Ignimbrite (3.2 Ma) and Patao Ignimbrite (3.1 Ma). Stratigraphically, the Main lava flow has a surface texture with strong similarities to an ʻaʻā lava flow, composed of three unique layers well distinguishable in the field such as i) Basal, ii) Top auto-breccia, composed of sub-angular scoriaceous and dense clasts in an oxidized matrix, and iii) A single core between both auto-breccias, composed of dense lavas, exhibiting multiple cooling jointing, such as vertical to platy jointing. The advanced stage of erosion since the formation of El País is evidenced by the poorly preserved lava flows (flat morphology), upper auto-breccia layer, and the presence of large sub-angular blocks of lava (vesicular and dense) along the axis of the lava flows. The eruptive products are geochemically basaltic andesite (Main lava flow and ephemeral vents) and andesite (specifically in the Northern lava flow), making the lava flow field one of the most mafic in the broader region. The lava presents a glomeroporphyric texture, showing at least three different glomerocrysts: i) Plagioclase + clinopyroxene having reabsorption boundaries, ii) Clinopyroxene with reabsorption boundaries, and iii) Plagioclase with sieve-texture. The groundmass is principally composed of glass, plagioclase microlites with a low orientation preference, and opaque minerals (magnetite). This study helps understand the development of dispersed-monogenetic-volcanism (e.g., Tilocálar complex and Cerro Tujle maar), and its relationship with neighboring polygenetic volcanism (e.g., Toloncha stratovolcano) in the Central Volcanic Zone of the Andes, northern Chile. • Different vent location during effusive eruption in lava flow field context. • Ascent rate of basic and intermediate volcanism related with deep source and low magma supply. • Erosion process in dessert climate. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
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