The Determinants of Soccer Player Substitutions: a Survival Analysis of the Spanish Soccer League

This paper analyzes the pattern of player substitutions during a soccer match, using data from the First Division (Primera División) of the Spanish National Soccer League in the 2004-2005 season. To do so, an inverse Gaussian hazard model is adopted to analyze the first substitutions of each team that take place at half-time and in the second half of matches. The results show that the most important factor is the score as it stands prior to the time of the player substitution. Furthermore, defensive substitutions are made later in the match than offensive substitutions. We also find some evidence that the home team makes more substitutions than the visiting team in the halftime interval.hazard model; soccer substitutions; strategy.

Application of finite difference method in the study of diffusion with chemical kinetics of first order

The mathematical modelling of diffusion of a bleaching agent into a porous material is studied in the present paper. Law of mass conservation was applied to analize the mass transfer of a reactant from the bulk into the external surface of a solid geometrically described as a flat plate. After diffusion of the reactant, surface reaction following kinetics of first order was considered to take place. The solution of the differential equation that described the process leaded to an equation that represents the concentration profile in function of distance, porosity and Thiele modulus. The case of interfacial mass resistance is also discused. In this case, finite difference method was used for the solution of the differential equation taking into account the respective boundary conditions. The profile of concentration can be obtained after numerical especification of Thiele modulus and Biot number.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)

Parameters determination for column design in gas absorption systems

Separation processes by means of mass transfer play a key role in chemical industry. Very often, a number of different components are present in streams from chemical reactors and some of them may be separated from the main stream for environmental reasons, for purification purposes, for commercialization, to be used in other chemical manufacturing process or even reused in the same process, to improve industrial performance, or for sale as a final product. Gas adsorption is one example of this separation process, where it is normally desired to separate a dilute component from a gas stream. In the present paper we studied packed columns by graphical and algebraic methods and determine the tower height using volumetric mass transfer coefficients, we analyze a gas stream that contains a defined amount of a gas, which concentration decreases after being in contact to a packed absorption tower, and model this process by mass balance taking into consideration volumetric mass transfer coefficients, operating line and equilibrium line of the process. The model allows us finally to understand the variation of height column with column diameter, which is particularly useful for the design of absorption columns as it requires the determination of these parameters. © 2019, World Scientific and Engineering Academy and Society. All rights reserved

Development of a catalytic model system using nitrous oxide

Currently, special attention is paid to partial oxidation of several sugar alcohols because it generates oxidation intermediate products with high utility value. In the present paper, we study the modelling of oxidation reaction of 1,2,3 propanotriol using an oxidizing agent in low concentrations. A major problem of such oxidation system is its low reactivity and high oxidation reactivity of products, As a result, the yield to a specific compound (i.e. dihydroxypropanal) depends on the ratio of rate constants of the consecutive reactions and also on the initial concentration of oxidizing agent. In this case, as the input value for the model calculations we chose a ratio of values of the specified rate constants and initial concentrations of nitrous oxide and 1,2,3-propanotriol. Accordingly, an experimental setup was proposed to follow the variation of temperature of the reaction blend after gradual addition of ammonium nitrate to a solution of 1,2,3 propanotriol, which can provide insights for the control of the chemical reactor. © 2018, World Scientific and Engineering Academy and Society. All Rights Reserved.LO1303, MŠMT, Ministerstvo Školství, Mládeže a Tělovýchov

Mathematical model of an integrated circuit cooling through cylindrical rods

One of the main challenges in integrated circuits development is to propose alternatives to handle the extreme heat generated by high frequency of electrons moving in a reduced space that cause overheating and reduce the lifespan of the device. The use of cooling fins offers an alternative to enhance the heat transfer using combined a conduction-convection systems. Mathematical model of such process is important for parametric design and also to gain information about temperature distribution along the surface of the transistor. In this paper, we aim to obtain the equations for heat transfer along the chip and the fin by performing energy balance and heat transfer by conduction from the chip to the rod, followed by dissipation to the surrounding by convection. Newton's law of cooling and Fourier law were used to obtain the equations that describe the profile temperature in the rod and the surface of the chip. Ordinary differential equations were obtained and the respective analytical solutions were derived after consideration of boundary conditions. The temperature along the rod decreased considerably from the initial temperature (in contatct with the chip surface). This indicates the benefit of using a cilindrical rod to distribute the heat generated in the chip.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA [CZ.1.05/2.1.00/03.0089]; Grant Agency of the Czech Republic [GACR 588 P103/15/06700S]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CebiaTech/2016/007]; National Council for Science and Technology (CONACYT) in Mexico; Council for Science and Technology of the State of Guanajuato (CONCYTEG) in Mexic

Modeling of the partial oxidation of glycerol by estimation of its transfer function

The reaction pathway for the conversion of glycerol into different products, namely glyceraldehyde, glyceric acid, glycolic acid, mesoxalic acid and tartronic acid was studied by means of electrochemistry. Multiple Pulse Amperometry technique was used to control the potential during the electrooxidation reaction. The estimation of the transfer function was realized on the basis of dynamic models for the oxidation reaction. The equations obtained in the s-domain were expressed in the time domain using Inverse Laplace transformation to describe the variation of glycerol and products concentration.Ministry of Education, Youth and Sports of the Czech Republic within the National Sustainability Programme [LO1303 (MSMT-7778/2014)]; European Regional Development Fund under the project CEBIA-Tech [CZ.1.05/2.1.00/03.0089

La accesibilidad del vídeo bajo demanda. Una asignatura pendiente en la regulación europea y española

El auge de nuevas formas de consumo audiovisual, de entre las que destaca el vídeo bajo demanda y las plataformas SVOD (subscription video on demand) como Netflix, hace necesario extender el concepto tradicional de accesibilidad de la televisión a toda la comunicación audiovisual. Sin embargo, la normativa, tanto en el ámbito televisivo como en el caso del vídeo bajo demanda, parece ir siempre por detrás del mercado, mostrando una clara distancia entre la implantación de los nuevos servicios y la regulación de los mismos a escala europea y nacional. Este estudio pone de relieve la necesidad de extender la obligatoriedad de la accesibilidad de la televisión a los contenidos bajo demanda para garantizar el derecho a la libertad de expresión y a recibir información en igualdad, fundamental en sociedades democráticas. Este derecho se garantiza mediante la implantación del subtitulado, la audiodescripción, la lengua de signos y los audiosubtítulos en los contenidos audiovisuales. La revisión bibliográfica y documental es el método aplicado en este estudio e incluye la regulación al respecto en la Unión Europea y España, así como la literatura científica publicada en esta área. De entre ella destaca la directiva europea más reciente (Directiva 2018/1808), que en su propia denominación reconoce la modificación de la norma a consecuencia de la “evolución de las realidades del mercado”

Development of Cocontinuous Morphologies in Initially Heterogeneous Thermosets Blended with Poly(methyl methacrylate)

Morphology and phase separation process in blends of a network-forming reactive polymer, poly(aminopropylmethylsiloxane) (PAMS), in a poly(methyl methacrylate) (PMMA)-modified epoxy system were studied using optical, epifluorescence and scanning electron microscopy, Fourier transform infrared spectroscopy (FTIR), and dynamic mechanical thermal analysis (DMTA). The thermoset system was bisphenol A diglycidyl ether (DGEBA) with different PMMA percentages, 2−10% w/w. Phase separation and reaction advancement were monitored in situ. At the concentration studied, PMMA does not influence the kinetics of the curing process, but it strongly affects the reactive compatibilization between DGEBA and PAMS. The morphology obtained consists of a continuous thermoplastic-rich phase surrounding thermosetting connected polyhedral particles of 5−15 μm. This cocontinuous morphology is observed independently of the percentage of PMMA. Results show that the morphology is strongly influenced by the diffusion and viscosity conditions during reactive compatibilization and phase separation. An increase in PMMA content leads to a decrease in the thermosetting polyhedral particle size. In contrast, an increase in curing temperature leads to bigger sizes. The addition of thermoplastic polymers to initially nonhomogeneous reactive blends is a potential route for generating cocontinuous morphologies irrespective of the thermoplastic contentThe authors would like to ex-press their gratitude to the Epoxsil (MAT2000-0391-P4-02) and Fibrodont (MAT2001-0677-P3) projects for financial support. The authors would also like to thank to Dr. I. Esteban (UNED) for his assistance with the TOM micrographs and to Dr. J. Iruin (UPV) for his assistance with the density measurements

Diseño definitivo comparativo del puente de 60.0 m. de luz sobre el rio Toachi en base a las normas AASHTO estándar y LRFD. : Tomo I

Generalidades. Análisis de estudios preliminares. Diseño estructural (código AASHTO estándar). Aplicación de las normas AASHTO LRFD al diseño estructural de puentes. Diseño estructural (código AASHTO estándar).Presupuesto y programación de obra. Comparación técnico económica. Impacto ambiental. Conclusiones y recomendaciones. Bibliografí

The Potential of Seaweeds as a Source of Functional Ingredients of Prebiotic and Antioxidant Value

Two thirds of the world is covered by oceans, whose upper layer is inhabited by algae. This means that there is a large extension to obtain these photoautotrophic organisms. Algae have undergone a boom in recent years, with consequent discoveries and advances in this field. Algae are not only of high ecological value but also of great economic importance. Possible applications of algae are very diverse and include anti-biofilm activity, production of biofuels, bioremediation, as fertilizer, as fish feed, as food or food ingredients, in pharmacology (since they show antioxidant or contraceptive activities), in cosmeceutical formulation, and in such other applications as filters or for obtaining minerals. In this context, algae as food can be of help to maintain or even improve human health, and there is a growing interest in new products called functional foods, which can promote such a healthy state. Therefore, in this search, one of the main areas of research is the extraction and characterization of new natural ingredients with biological activity (e.g., prebiotic and antioxidant) that can contribute to consumers? well-being. The present review shows the results of a bibliographic survey on the chemical composition of macroalgae, together with a critical discussion about their potential as natural sources of new functional ingredients.Fil: Gomez Zavaglia, Andrea. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Criotecnología de Alimentos. Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Criotecnología de Alimentos; ArgentinaFil: Prieto Lage, Miguel Ángel. Universidad de Vigo; EspañaFil: Jiménez López, Cecilia. Universidad de Vigo.; EspañaFil: Mejuto, Juan Carlos. Universidad de Vigo. Facultad de Ciencias de Ourense; EspañaFil: Simal Gándara, Jesús. Universidad de Vigo; Españ