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The Unmanned Underwater Vehicles (UUV) designed for the detection and neutralization of naval mines are characterized by their high requirements regarding the reduction of the signatures of a vessel (thermal, acoustic, magnetic, etc.), all of them must be reduced in order not to be detected by the mines during the mission. This research work focuses on the reduction of the thermal signature transmitted by the UUV hull, where the use of phase change materials (PCM) is proposed as thermal insulation, placing it between the internal heat source of the UUV and the pressure hull, with the aim of drastically increasing the time in which the external face of the hull of the UUV is within a range of 3 °C and 5 °C temperature increase, allowing it to perform its mission without being detected by the thermal sensors of current naval mines. The simulation will be carried out using the Network Simulation Method for the resolution of the governing equations, which will allow the optimization of the necessary insulation thickness according to the required mission profile. In addition, it is proposed an expression that relates the PCM thickness and the time needed to reach a certain temperature increase.
Juan Francisco Sánchez-Pérez; Carlos Mascaraque-Ramírez; Jose Andrés Moreno Nicolás; Enrique Castro; Manuel Cánovas. Study of the application of PCM to thermal insulation of UUV hulls using Network Simulation Method. Alexandria Engineering Journal 2021, 60, 4627 -4637.
AMA StyleJuan Francisco Sánchez-Pérez, Carlos Mascaraque-Ramírez, Jose Andrés Moreno Nicolás, Enrique Castro, Manuel Cánovas. Study of the application of PCM to thermal insulation of UUV hulls using Network Simulation Method. Alexandria Engineering Journal. 2021; 60 (5):4627-4637.
Chicago/Turabian StyleJuan Francisco Sánchez-Pérez; Carlos Mascaraque-Ramírez; Jose Andrés Moreno Nicolás; Enrique Castro; Manuel Cánovas. 2021. "Study of the application of PCM to thermal insulation of UUV hulls using Network Simulation Method." Alexandria Engineering Journal 60, no. 5: 4627-4637.
This study deals with the potential use of water stored in a lake formed by Reocín’s old zinc mine, which has become the second most important reservoir in Cantabria, with a flow of 1300 L s−1. The methodology used is based on the hydrogeological and hydrochemical characterization of the area studied. A total of 16 piezometers were installed to monitor the amount and quality of water. Results obtained show a pH close to 8 and iron, manganese, zinc, and sulphate concentrations lower than 0.05 mg L−1, 0.05 mg L−1, 1.063 mg L−1, and 1305.5 mg L−1, respectively. The volume of the water stored in the lake amounts to 34 hm3. Measurements show that Fe, Mn, and Zn concentrations are below the limits acceptable for human consumption, according to the Spanish 0.2, 0.05, and 5.0 mg L−1 standards, respectively, while sulphate greatly exceeds the 250 mg L−1 limit accepted by the norm. Therefore, the water could be apt for human consumption after a treatment appropriate for decreasing the sulphate level by, for example, reverse osmosis, distillation, or ion exchange. Although industrial and energy uses are possible, the lake water could be utilized as a geothermal energy source. The management of the hydric resources generated when a mine is closed could improve the economic and environmental conditions of the zone, with all the benefits it brings about, thus allowing for compensating of the pumping cost that environmental protection entails, creating, at the same time, a new business opportunity for the company that owns the mine.
Noemí Barral; Raúl Husillos; Elena Castillo; Manuel Cánovas; Elizabeth Lam; Lucas Calvo. Volumetric Quantification and Quality of Water Stored in a Mining Lake: A Case Study at Reocín Mine (Spain). Minerals 2021, 11, 212 .
AMA StyleNoemí Barral, Raúl Husillos, Elena Castillo, Manuel Cánovas, Elizabeth Lam, Lucas Calvo. Volumetric Quantification and Quality of Water Stored in a Mining Lake: A Case Study at Reocín Mine (Spain). Minerals. 2021; 11 (2):212.
Chicago/Turabian StyleNoemí Barral; Raúl Husillos; Elena Castillo; Manuel Cánovas; Elizabeth Lam; Lucas Calvo. 2021. "Volumetric Quantification and Quality of Water Stored in a Mining Lake: A Case Study at Reocín Mine (Spain)." Minerals 11, no. 2: 212.
RESUMEN Chile es el mayor exportador de cobre del mundo. Sin embargo, este liderazgo tiene importantes costos medioambientales como la generación de enormes cantidades de residuos sólidos procedentes del tratamiento de las menas de cobre. Con objeto de abordar esta problemática, se propone la aplicación de la técnica de drenaje electroosmótico a ripios y relaves. La parte experimental del trabajo consiste en un diseño experimental con matrices sólidas sintéticas. El porcentaje de finos y la humedad inicial se definen como factores de tres niveles. El volumen de líquido drenado se define como la variable respuesta. Los resultados muestran que el drenaje electroosmótico es más eficiente que el drenaje gravitacional cuando el contenido de humedad y el porcentaje de finos se encuentran en su nivel más alto. Mediante un análisis de varianza del diseño experimental, se corrobora el efecto de los factores y su interacción en la variable de respuesta. Finalmente, se genera una ecuación que describe la relación entre las variables de respuesta y los factores del modelo.
Julio Valenzuela; Manuel Cánovas; Paul González; Cristian Cuevas. Aplicación de drenaje electroosmótico a pasivos ambientales mineros. Matéria (Rio de Janeiro) 2021, 26, 1 .
AMA StyleJulio Valenzuela, Manuel Cánovas, Paul González, Cristian Cuevas. Aplicación de drenaje electroosmótico a pasivos ambientales mineros. Matéria (Rio de Janeiro). 2021; 26 (1):1.
Chicago/Turabian StyleJulio Valenzuela; Manuel Cánovas; Paul González; Cristian Cuevas. 2021. "Aplicación de drenaje electroosmótico a pasivos ambientales mineros." Matéria (Rio de Janeiro) 26, no. 1: 1.
A mathematical model for the simulation of the diffusion of the pollutants released from a point source is presented. All phenomena have been included, such as thermal and wind gradients, turbulence, fumigation, convective and diffusive effects, and atmospheric stabilities. To better understand the dynamics of these occurrences, the Network Simulation Method was used to provide the concentration of pollutants in three spatial coordinates. The model was simulated in open source software and validated with experimental data, satisfying the Hanna criteria. Additionally, this model selects for the appropriate expressions based on the physical phenomena that govern each case and allows for time-dependent data entry. The cases studied show the great coupling that exists between the variables of wind velocity and atmospheric stability for the pollutant diffusion. The model can be used for two important aims, to identify the behavior of the emission of pollutants, and to determine the concentration of a pollutant at various points, through an inverse problem, locating the source of the emission.
Juan Francisco Sánchez-Pérez; María Rosa Mena-Requena; Manuel Cánovas. Mathematical Modeling and Simulation of a Gas Emission Source Using the Network Simulation Method. Mathematics 2020, 8, 1996 .
AMA StyleJuan Francisco Sánchez-Pérez, María Rosa Mena-Requena, Manuel Cánovas. Mathematical Modeling and Simulation of a Gas Emission Source Using the Network Simulation Method. Mathematics. 2020; 8 (11):1996.
Chicago/Turabian StyleJuan Francisco Sánchez-Pérez; María Rosa Mena-Requena; Manuel Cánovas. 2020. "Mathematical Modeling and Simulation of a Gas Emission Source Using the Network Simulation Method." Mathematics 8, no. 11: 1996.
This paper intends to validate the application of magnetic techniques, particularly magnetic susceptibility, as sampling tools on a copper tailings terrace, by correlating them analytically. Magnetic susceptibility was measured in both the field and laboratory. Data obtained allowed for designing spatial magnetic susceptibility distribution maps, showing the horizontal variation of the tailings. In addition, boxplots were used to show the variation of magnetic susceptibility and the concentration of the elements analyzed at different depths of the copper tailings terrace. The degree of correlation between magnetic and chemical variables was defined with coefficient R2. The horizontal and vertical variations of magnetic susceptibility, the concentration of elements, and the significant correlations between them show a relationship between magnetic susceptibility and the chemical processes occurring in the tailing management facility, such as pyrite oxidation. Thus, the correlation functions obtained could be used as semiquantitative tools to characterize tailings or other mining residues.
Elizabeth J. Lam; Rodrigo Carle; Rodrigo González; Ítalo L. Montofré; Eugenio A. Veloso; Antonio Bernardo; Manuel Cánovas; Fernando A. Álvarez. A Methodology Based on Magnetic Susceptibility to Characterize Copper Mine Tailings. Minerals 2020, 10, 939 .
AMA StyleElizabeth J. Lam, Rodrigo Carle, Rodrigo González, Ítalo L. Montofré, Eugenio A. Veloso, Antonio Bernardo, Manuel Cánovas, Fernando A. Álvarez. A Methodology Based on Magnetic Susceptibility to Characterize Copper Mine Tailings. Minerals. 2020; 10 (11):939.
Chicago/Turabian StyleElizabeth J. Lam; Rodrigo Carle; Rodrigo González; Ítalo L. Montofré; Eugenio A. Veloso; Antonio Bernardo; Manuel Cánovas; Fernando A. Álvarez. 2020. "A Methodology Based on Magnetic Susceptibility to Characterize Copper Mine Tailings." Minerals 10, no. 11: 939.
A study of transition zones in the carbon monoxide catalytic oxidation over platinum is presented. After the design of a network model following the rules of the Network Simulation Method, it is run in a standard (free) software providing the fractional coverages of all species for different values of carbon monoxide partial pressure, the main parameter that produces the change between a stationary or periodic response. The design of the model is explained in detail and no assumptions are made concerning the removing of oxidation fractional coverage. The illusory chaotic behavior associated with an inadequate time step in the numerical algorithm is studied. This work provides an explanation for the transition (bifurcation) between the stationary and the periodical response studies making use of Poincaré plane and phase-diagrams. The extinction of variable fluctuation in the transition zone is analyzed to understand its relation with given values of transition partial pressures. Of particular interest is the small time span of the superficial fractional coverage of carbon monoxide fluctuation near the second transition partial pressure.
Juan Francisco Sánchez-Pérez; Jose Andres Moreno Nicolas; Francisco Alhama; Manuel Canovas. Study of Transition Zones in the Carbon Monoxide Catalytic Oxidation on Platinum Using the Network Simulation Method. Mathematics 2020, 8, 1413 .
AMA StyleJuan Francisco Sánchez-Pérez, Jose Andres Moreno Nicolas, Francisco Alhama, Manuel Canovas. Study of Transition Zones in the Carbon Monoxide Catalytic Oxidation on Platinum Using the Network Simulation Method. Mathematics. 2020; 8 (9):1413.
Chicago/Turabian StyleJuan Francisco Sánchez-Pérez; Jose Andres Moreno Nicolas; Francisco Alhama; Manuel Canovas. 2020. "Study of Transition Zones in the Carbon Monoxide Catalytic Oxidation on Platinum Using the Network Simulation Method." Mathematics 8, no. 9: 1413.
The normalization of dimensionless groups that rule the system of nonlinear coupled ordinary differential equations defined by the Lotka–Volterra biological or chemical oscillator has been derived in this work by applying a normalized nondimensionalization protocol. The normalization procedure, which is quite accurate, does not require complex mathematical steps; however, a deep physical understanding of the problem is required to choose the appropriate references to define the dimensionless variables. From the dimensionless groups derived, the functional dependences of some unknowns of interest are established. Due to the coupled nature of the problem that induces temporal concentration rates of each species that are quite different at each point of the phase diagram, this diagram has been divided into four stretches corresponding to the four quadrants. For each stretch, the limit values (maximum or minimum) of the variables, as well as their duration, are expressed in terms of the dimensionless groups derived before. Finally, to check all the mentioned dependences, a numerical simulation has been carried out.
Juan Francisco Sánchez-Pérez; Manuel Conesa; Iván Alhama; Manuel Cánovas. Study of Lotka–Volterra Biological or Chemical Oscillator Problem Using the Normalization Technique: Prediction of Time and Concentrations. Mathematics 2020, 8, 1324 .
AMA StyleJuan Francisco Sánchez-Pérez, Manuel Conesa, Iván Alhama, Manuel Cánovas. Study of Lotka–Volterra Biological or Chemical Oscillator Problem Using the Normalization Technique: Prediction of Time and Concentrations. Mathematics. 2020; 8 (8):1324.
Chicago/Turabian StyleJuan Francisco Sánchez-Pérez; Manuel Conesa; Iván Alhama; Manuel Cánovas. 2020. "Study of Lotka–Volterra Biological or Chemical Oscillator Problem Using the Normalization Technique: Prediction of Time and Concentrations." Mathematics 8, no. 8: 1324.
Manuel Cánovas; Julio Valenzuela; Leonardo Romero; Paul González. Characterization of electroosmotic drainage: application to mine tailings and solid residues from leaching. Journal of Materials Research and Technology 2020, 9, 2960 -2968.
AMA StyleManuel Cánovas, Julio Valenzuela, Leonardo Romero, Paul González. Characterization of electroosmotic drainage: application to mine tailings and solid residues from leaching. Journal of Materials Research and Technology. 2020; 9 (3):2960-2968.
Chicago/Turabian StyleManuel Cánovas; Julio Valenzuela; Leonardo Romero; Paul González. 2020. "Characterization of electroosmotic drainage: application to mine tailings and solid residues from leaching." Journal of Materials Research and Technology 9, no. 3: 2960-2968.
The authors wish to make the following corrections to this paper
David Torres; Luís Ayala; Manuel Saldaña; Manuel Cánovas; Ricardo I. Jeldres; Steven Nieto; Jonathan Castillo; Pedro Robles; Norman Toro. Correction: Torres, D. et al. Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents. Metals 2019, 9, 1316. Metals 2020, 10, 506 .
AMA StyleDavid Torres, Luís Ayala, Manuel Saldaña, Manuel Cánovas, Ricardo I. Jeldres, Steven Nieto, Jonathan Castillo, Pedro Robles, Norman Toro. Correction: Torres, D. et al. Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents. Metals 2019, 9, 1316. Metals. 2020; 10 (4):506.
Chicago/Turabian StyleDavid Torres; Luís Ayala; Manuel Saldaña; Manuel Cánovas; Ricardo I. Jeldres; Steven Nieto; Jonathan Castillo; Pedro Robles; Norman Toro. 2020. "Correction: Torres, D. et al. Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents. Metals 2019, 9, 1316." Metals 10, no. 4: 506.
The deposits of Fe-Mn, in the seabed of the planet, are a good alternative source for the extraction of elements of interest. Among these are marine nodules, which have approximately 24% manganese and may be a solution to the shortage of high-grade ores on the surface. In this investigation, an ANOVA analysis was performed to evaluate the time independent variables and MnO2/reducing agent in the leaching of manganese nodules with the use of different Fe reducing agents (FeS2, Fe2+, Fe0 and Fe2O3). Tests were also carried out for the different reducing agents evaluating the MnO2/Fe ratio, in which the Fe0 (FeC) proved to be the best reducing agent for the dissolution of Mn from marine nodules, achieving solutions of 97% in 20 min. In addition, it was discovered that at low MnO2/Fe ratios the acid concentration in the system is not very relevant and the potential and pH were in ranges of −0.4–1.4 V and −2–0.1 favoring the dissolution of Mn from MnO2.
David Torres; Luís Ayala; Manuel Saldaña; Manuel Cánovas; Ricardo I. Jeldres; Steven Nieto; Jonathan Castillo; Pedro Robles; Norman Toro. Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents. Metals 2019, 9, 1316 .
AMA StyleDavid Torres, Luís Ayala, Manuel Saldaña, Manuel Cánovas, Ricardo I. Jeldres, Steven Nieto, Jonathan Castillo, Pedro Robles, Norman Toro. Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents. Metals. 2019; 9 (12):1316.
Chicago/Turabian StyleDavid Torres; Luís Ayala; Manuel Saldaña; Manuel Cánovas; Ricardo I. Jeldres; Steven Nieto; Jonathan Castillo; Pedro Robles; Norman Toro. 2019. "Leaching Manganese Nodules in an Acid Medium and Room Temperature Comparing the Use of Different Fe Reducing Agents." Metals 9, no. 12: 1316.
Chalcopyrite is the most abundant copper ore and, consequently, the most utilised to produce metallic copper. The main route of treatment is through pyrometallurgical processes, but these emit significant quantities of SO2 into the atmosphere (e.g. 182,000 t/year among all Chilean smelters), producing mighty concern in the community. In this context, hydrometallurgy is presented as an alternative that may be more environmentally friendly; however, the difficulties of processing sulphide minerals prevent achieving sustainable efficiencies for the industry. In this research, a pure chalcopyrite mineral is leached at 25 °C with the addition of manganese nodules as an oxidizing agent, and wastewater with a high concentration of chloride that both enhances the dissolution and avoid the passivation of the chalcopyrite. The high concentrations of MnO2 (4/1 and 5/1) allows that the potential values can be between 580 and 650 mV, which favors the dissolution of CuFeS2. The XRD showed the formation of non-polluting species and, besides, they do not cause obstacles to the copper dissolution. High concentrations of chloride enable increasing copper solutions from CuFeS2, attaining favorable outcomes when working with wastewater instead of seawater.
Norman Toro; Kevin Pérez; Manuel Saldaña; Ricardo I. Jeldres; Matías Jeldres; Manuel Cánovas. Dissolution of pure chalcopyrite with manganese nodules and waste water. Journal of Materials Research and Technology 2019, 9, 798 -805.
AMA StyleNorman Toro, Kevin Pérez, Manuel Saldaña, Ricardo I. Jeldres, Matías Jeldres, Manuel Cánovas. Dissolution of pure chalcopyrite with manganese nodules and waste water. Journal of Materials Research and Technology. 2019; 9 (1):798-805.
Chicago/Turabian StyleNorman Toro; Kevin Pérez; Manuel Saldaña; Ricardo I. Jeldres; Matías Jeldres; Manuel Cánovas. 2019. "Dissolution of pure chalcopyrite with manganese nodules and waste water." Journal of Materials Research and Technology 9, no. 1: 798-805.
Raffinate is an aqueous acid phase with low copper content obtained in the solvent extraction phase (SX). This solution, which drags a significant amount of the organic phase that forms an oil-in-water (O/W) emulsion, is recycled back to the leaching phase as an irrigation solution. In addition, the formation of emulsions can cause operational problems in the leaching phase. To solve these problems, this work is aimed to employ electrocoalescence under AC electrical fields to enhance demulsification of the emulsions that formed. The main objectives of this work were to select the most appropriate electrode and conduct laboratory tests based on a 23 factorial design to determine the variables that have the most significant effect on electrocoalescence. The variables considered were distance, frequency and voltage, while TOC removal and actual power were the response variables. The distance between electrodes is the most important parameter affecting TOC removal. In relation to actual power, the voltage applied was more significant than the distance between electrodes, the frequency and the interactions among variables. The tests to determine the optimal type of electrode identified rectangular steel plate electrodes as providing the best results. The operational parameters: a voltage of 30 V, a frequency of 400 Hz and an electrode distance of 14 cm showed the greatest efficiency. Considering these results, it is demonstrated that electrocoalescence enhances demulsification of O/W emulsions in raffinate from solvent extraction in copper processing.
Julio Valenzuela-Elgueta; Manuel Cánovas; Antonio García; Ramón Zárate. Electrocoalescence of emulsions in raffinate from the solvent extraction phase under AC electrical fields. Journal of Materials Research and Technology 2019, 9, 490 -497.
AMA StyleJulio Valenzuela-Elgueta, Manuel Cánovas, Antonio García, Ramón Zárate. Electrocoalescence of emulsions in raffinate from the solvent extraction phase under AC electrical fields. Journal of Materials Research and Technology. 2019; 9 (1):490-497.
Chicago/Turabian StyleJulio Valenzuela-Elgueta; Manuel Cánovas; Antonio García; Ramón Zárate. 2019. "Electrocoalescence of emulsions in raffinate from the solvent extraction phase under AC electrical fields." Journal of Materials Research and Technology 9, no. 1: 490-497.
Chalcocite is the most important and abundant secondary copper ore in the world with a rapid dissolution of copper in an acid-chloride environment. In this investigation, the methodology of surface optimization will be applied to evaluate the effect of three independent variables (time, concentration of sulfuric acid and chloride concentration) in the leaching of pure chalcocite to extract the copper with the objective of obtaining a quadratic model that allows us to predict the extraction of copper. The kinetics of copper dissolution in regard to the function of temperature is also analyzed. An ANOVA indicates that the linear variables with the greatest influence are time and the chloride concentration. Also, the concentration of chloride-time exerts a significant synergic effect in the quadratic model. The ANOVA indicates that the quadratic model is representative and the R2 value of 0.92 is valid. The highest copper extraction (67.75%) was obtained at 48 h leaching under conditions of 2 mol/L H2SO4 and 100 g/L chloride. The XRD analysis shows the formation of a stable and non-polluting residue; such as elemental sulfur (S0). This residue was obtained in a leaching time of 4 h at room temperature under conditions of 0.5 mol/L H2SO4 and 50 g/L Cl−.
Norman Toro; Williams Briceño; Kevin Pérez; Manuel Cánovas; Emilio Trigueros; Rossana Sepúlveda; Pía Hernández. Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water. Metals 2019, 9, 780 .
AMA StyleNorman Toro, Williams Briceño, Kevin Pérez, Manuel Cánovas, Emilio Trigueros, Rossana Sepúlveda, Pía Hernández. Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water. Metals. 2019; 9 (7):780.
Chicago/Turabian StyleNorman Toro; Williams Briceño; Kevin Pérez; Manuel Cánovas; Emilio Trigueros; Rossana Sepúlveda; Pía Hernández. 2019. "Leaching of Pure Chalcocite in a Chloride Media Using Sea Water and Waste Water." Metals 9, no. 7: 780.
Manganese nodules are an attractive source of base metals and critical and rare elements and are required to meet a high demand of today’s industry. In previous studies, it has been shown that high concentrations of reducing agent (Fe) in the system are beneficial for the rapid extraction of manganese. However, it is necessary to optimize the operational parameters in order to maximize Mn recovery. In this study, a statistical analysis was carried out using factorial experimental design for the main parameters, including time, MnO2/Fe2O3 ratio, and H2SO4 concentration. After this, Mn recovery tests were carried out over time at different ratios of MnO2/Fe2O3 and H2SO4 concentrations, where the potential and pH of the system were measured. Finally, it is concluded that high concentrations of FeSO4 in the system allow operating in potential and pH ranges (−0.2 to 1.2 V and −1.8 to 0.1) that favor the formation of Fe2+ and Fe3+, which enable high extractions of Mn (73%) in short periods of time (5 to 20 min) operating with an optimum MnO2/Fe2O3 ratio of 1:3 and a concentration of 0.1 mol/L of H2SO4.
Norman Toro; Manuel Saldaña; Edelmira Galvez; Manuel Cánovas; Emilio Trigueros; Jonathan Castillo; Pía C. Hernández. Optimization of Parameters for the Dissolution of Mn from Manganese Nodules with the Use of Tailings in An Acid Medium. Minerals 2019, 9, 387 .
AMA StyleNorman Toro, Manuel Saldaña, Edelmira Galvez, Manuel Cánovas, Emilio Trigueros, Jonathan Castillo, Pía C. Hernández. Optimization of Parameters for the Dissolution of Mn from Manganese Nodules with the Use of Tailings in An Acid Medium. Minerals. 2019; 9 (7):387.
Chicago/Turabian StyleNorman Toro; Manuel Saldaña; Edelmira Galvez; Manuel Cánovas; Emilio Trigueros; Jonathan Castillo; Pía C. Hernández. 2019. "Optimization of Parameters for the Dissolution of Mn from Manganese Nodules with the Use of Tailings in An Acid Medium." Minerals 9, no. 7: 387.
In this paper, a relation between the ultraviolet index (UVI) as a Sun exposure time and its effects in the form of burns according to the skin type has been elaborated. Moreover, we present a new expression that relates the intensity of solar radiation and the UVI, as well as expressions to obtain the percentage of population affected both by first and second degree lllsunburn for every skin-type. The results have been adjusted and validated through experimental results taken from the bibliography. Finally, this paper presents a table where the population can easily interpret the UVI values and calculate the maximum time one can be exposed to solar radiation without getting sunburn. In addition, this article aims to raise awareness of the potential harm caused by solar radiation by indicating the percentage of population affected by different types of sunburn depending on skin-type. Moreover, ultraviolet exposure to sunlight could not just result in sunburn, but also have long-term effects on eyes, or even cause immune system disorders or melanoma. Therefore, managing risk perception with this useful table could familiarize the population with actual harm prevention.
J. F. Sánchez-Pérez; D. Vicente-Agullo; M. Barberá; E. Castro-Rodríguez; M. Cánovas. Relationship between ultraviolet index (UVI) and first-, second- and third-degree sunburn using the Probit methodology. Scientific Reports 2019, 9, 733 .
AMA StyleJ. F. Sánchez-Pérez, D. Vicente-Agullo, M. Barberá, E. Castro-Rodríguez, M. Cánovas. Relationship between ultraviolet index (UVI) and first-, second- and third-degree sunburn using the Probit methodology. Scientific Reports. 2019; 9 (1):733.
Chicago/Turabian StyleJ. F. Sánchez-Pérez; D. Vicente-Agullo; M. Barberá; E. Castro-Rodríguez; M. Cánovas. 2019. "Relationship between ultraviolet index (UVI) and first-, second- and third-degree sunburn using the Probit methodology." Scientific Reports 9, no. 1: 733.
Nonlinear consolidation scenarios, based on potential type constitutive dependences—like those proposed by Juárez-Badillo—and eliminating the more restrictive hypothesis of 1+e and dz constant, were characterized by the nondimensionalization process of the governing equations, providing the independent dimensionless groups that rule the main unknowns of interest. From these, universal curves have been depicted for both the characteristic time and the average degree of consolidation. The solutions were verified by numerical simulations and successfully compared in a case study, showing the simplicity of use of the curves and the high reliability of the solutions they provide.
Gonzalo García-Ros; Iván Alhama; Manuel Cánovas; Francisco Alhama. Derivation of Universal Curves for Nonlinear Soil Consolidation with Potential Constitutive Dependences. Mathematical Problems in Engineering 2018, 2018, 1 -15.
AMA StyleGonzalo García-Ros, Iván Alhama, Manuel Cánovas, Francisco Alhama. Derivation of Universal Curves for Nonlinear Soil Consolidation with Potential Constitutive Dependences. Mathematical Problems in Engineering. 2018; 2018 ():1-15.
Chicago/Turabian StyleGonzalo García-Ros; Iván Alhama; Manuel Cánovas; Francisco Alhama. 2018. "Derivation of Universal Curves for Nonlinear Soil Consolidation with Potential Constitutive Dependences." Mathematical Problems in Engineering 2018, no. : 1-15.
This paper presents a mathematical model of pitting corrosion formed by eight non-linear coupled differential equations and their boundary equations. In this model we studied the effect of the variation of parameter values (temperature, crevice depth, oxygen and sodium chloride concentration outside the cavity, and pH) on all the concentrations of the species, and on their differences with their concentrations outside the crevice and along the cavity using the network method. Moreover, a sensitivity study of the system parameters has been carried out. No simplifications have been considered, although the model is firmly coupled and susceptible to any variation of the aforementioned parameters. The development of the model is clearly explained. The results are compared with data published in the scientific literature for domains that establish the most complex and complete scenarios to verify the reliability of the model. One of the practical applications of this work, among others, is focused on the possible effects of this type of corrosion on the reinforced concrete, in buried pipes and on ship hulls.
J.F. Sánchez-Pérez; F. Alhama; J.A. Moreno; M. Cánovas. Study of main parameters affecting pitting corrosion in a basic medium using the network method. Results in Physics 2018, 12, 1015 -1025.
AMA StyleJ.F. Sánchez-Pérez, F. Alhama, J.A. Moreno, M. Cánovas. Study of main parameters affecting pitting corrosion in a basic medium using the network method. Results in Physics. 2018; 12 ():1015-1025.
Chicago/Turabian StyleJ.F. Sánchez-Pérez; F. Alhama; J.A. Moreno; M. Cánovas. 2018. "Study of main parameters affecting pitting corrosion in a basic medium using the network method." Results in Physics 12, no. : 1015-1025.
The solution to the 2-D consolidation problem, both for rectangular and cylindrical domains, has been widely studied in the scientific literature, reporting the most precise solutions in the form of analytical expressions difficult to handle for the engineer due to the high number of parameters involved. In this paper, after introducing a precise definition of the characteristic time, both this magnitude and the average degree of consolidation are obtained in terms of the least number of dimensionless groups that rule the problem. To do this, the groups are firstly derived from the dimensionless governing equations deduced from the mathematical model, following a discriminated nondimensionalization procedure which provides new groups that cannot be obtained by classical nondimensionalization. By a large number of numerical simulations, the dependences of the characteristic time and the average degree of consolidation on the new dimensionless groups have allowed to represent these unknowns graphically in the form of universal curves. This allows these quantities to be read with the least mathematical effort. A case study is solved to demonstrate the reliability and accuracy of the results.
Gonzalo García-Ros; Iván Alhama; Manuel Cánovas. Use of discriminated nondimensionalization in the search of universal solutions for 2-D rectangular and cylindrical consolidation problems. Open Geosciences 2018, 10, 209 -221.
AMA StyleGonzalo García-Ros, Iván Alhama, Manuel Cánovas. Use of discriminated nondimensionalization in the search of universal solutions for 2-D rectangular and cylindrical consolidation problems. Open Geosciences. 2018; 10 (1):209-221.
Chicago/Turabian StyleGonzalo García-Ros; Iván Alhama; Manuel Cánovas. 2018. "Use of discriminated nondimensionalization in the search of universal solutions for 2-D rectangular and cylindrical consolidation problems." Open Geosciences 10, no. 1: 209-221.
Mathematical models simulating different and representative engineering problem, atomic dry friction, the moving front problems and elastic and solid mechanics are presented in the form of a set of non-linear, coupled or not coupled differential equations. For different parameters values that influence the solution, the problem is numerically solved by the network method, which provides all the variables of the problems. Although the model is extremely sensitive to the above parameters, no assumptions are considered as regards the linearization of the variables. The design of the models, which are run on standard electrical circuit simulation software, is explained in detail. The network model results are compared with common numerical methods or experimental data, published in the scientific literature, to show the reliability of the model.
J. F. Sánchez-Pérez; Francisco Marin; J. L. Morales; M. Cánovas; F. Alhama. Modeling and simulation of different and representative engineering problems using Network Simulation Method. PLOS ONE 2018, 13, e0193828 .
AMA StyleJ. F. Sánchez-Pérez, Francisco Marin, J. L. Morales, M. Cánovas, F. Alhama. Modeling and simulation of different and representative engineering problems using Network Simulation Method. PLOS ONE. 2018; 13 (3):e0193828.
Chicago/Turabian StyleJ. F. Sánchez-Pérez; Francisco Marin; J. L. Morales; M. Cánovas; F. Alhama. 2018. "Modeling and simulation of different and representative engineering problems using Network Simulation Method." PLOS ONE 13, no. 3: e0193828.
The present work describes the program Simulation of Consolidation with Vertical Drains (SICOMED_2018), a tool for the solution of consolidation processes in heterogeneous soils, with totally or partially penetrating prefabricated vertical drains (PVD) and considering both the effects of the smear zone, generated when introducing the drain into the ground, and the limitation in the discharge capacity of the drain. In order to provide a completely free program, the code Next-Generation Simulation Program with Integrated Circuit Emphasis (Ngspice) has been used as a numerical tool while the Matrix Laboratory (MATLAB) code was used to program and create an interface with the user through interactive screens. In this way, SICOMED_2018 is presented as an easy-to-use and intuitive program, with a simple graphical interface that allows the user to enter all the soil properties and geometry of the problem without having to resort to a complex software package that requires programming. Illustrative applications describe both the versatility of the program and the reliability of its numerical solutions.
Gonzalo García-Ros; Ivan Alhama; Manuel Cánovas. Powerful Software to Simulate Soil Consolidation Problems with Prefabricated Vertical Drains. Water 2018, 10, 242 .
AMA StyleGonzalo García-Ros, Ivan Alhama, Manuel Cánovas. Powerful Software to Simulate Soil Consolidation Problems with Prefabricated Vertical Drains. Water. 2018; 10 (3):242.
Chicago/Turabian StyleGonzalo García-Ros; Ivan Alhama; Manuel Cánovas. 2018. "Powerful Software to Simulate Soil Consolidation Problems with Prefabricated Vertical Drains." Water 10, no. 3: 242.