Una nueva subespecie de Moricandia moricandioides (Boiss.) Heywood (Brassicaceae).

A new subspecies of Moricandia moricandioides (Boiss.) Heywood (Brassicaceae). Palabras clave: Moricandia, Brassicaceae, Murcia, España.Key words: Moricandia, Brassicaceae, Murcia, Spain

Solving initial value problems for ordinary differential equations by two approaches: BDF and Piecewise-linearized methods

Many scientific and engineering problems are described using Ordinary Differential Equations (ODEs), where the analytic solution is unknown. Much research has been done by the scientific community on developing numerical methods which can provide an approximate solution of the original ODE. In this work, two approaches have been considered based on BDF and Piecewise-linearized Methods. The approach based on BDF methods uses a Chord–Shamanskii iteration for computing the nonlinear system which is obtained when the BDF schema is used. Two approaches based on piecewise-linearized methods have also been considered. These approaches are based on a theorem proved in this paper which allows to compute the approximate solution at each time step by means of a block-oriented method based on diagonal Padé approximations. The difference between these implementations is in using or not using the scale and squaring technique. Five algorithms based on these approaches have been developed. MATLAB and Fortran versions of the above algorithms have been developed, comparing both precision and computational costs. BLAS and LAPACK libraries have been used in Fortran implementations. In order to compare in equality of conditions all implementations, algorithms with fixed step have been considered. Four of the five case studies analyzed come from biology and chemical kinetics stiff problems. Experimental results show the advantages of the proposed algorithms, especially when they are integrating stiff problems.Ibáñez González, JJ.; Hernández García, V.; Arias, E.; Ruíz Martínez, PA. (2009). Solving initial value problems for ordinary differential equations by two approaches: BDF and Piecewise-linearized methods. Computer Physics Communications. 180(5):712-723. doi:10.1016/j.cpc.2008.11.013S712723180

Análisis del juego de ataque en balonmano femenino

.- This study focuses on the specific organization of the attacking strategies in women's handball. In particular, we explore the specific weight of the two possible modalities of attack: positional and counterattack. To do so, during the 2008/2009 season, we have analyzed through a systematic observation methodology, direct and non-participant, the matches of a team that plays in the First Division of Women's Handball. To determine the rates of effectiveness, we have studied more than 2000 attacks and 900 throws on goal. Statistical analysis revealed that counterattack is more effective than positional play, and that it has a closer relationship with victory.Este estudio examinó la específica organización del juego de ataque en balonmano femenino. En concreto, hemos explorando el peso específico de los dos posibles tipos de ataque: posicional y contraataque. Para ello, hemos analizado los partidos de un mismo equipo de División de Honor Femenina durante la temporada 2008/2009 mediante metodología de la observación sistemática, directa y no participante. Hemos estudiado más de 2000 jugadas de ataque y 900 lanzamientos a portería, determinando de esta manera los índices de efectividad. El análisis estadístico reveló que existe una mayor eficacia del contraataque frente al juego posicional, además de una mayor relación con la victoria final

Pumped heat energy storage with liquid media: Thermodynamic assessment by a Brayton-like model

[EN]A thermodynamic model for a steady state pumped heat energy storage in liquid media is presented: it comprises a coupled Brayton-like heat pump and heat engine cycles connected to a cryogenic liquid and a hot molten salt by counter-flow heat exchangers. The model considers non-isothermal heat transfers between the working fluid and the liquid media and explicitly includes a set of parameters accounting for the main internal and external losses, heat leak, and pinch point effects for both the heat pump (charge) and heat engine (discharge) modes. Specific expressions for the main magnitudes in the charge (as the input power and coefficient of performance) and discharge (as power output and efficiency) modes and the global round trip efficiency have been analytically derived in terms of isentropic efficiencies of the compressor and turbine, pressure losses in the heat exchange processes, effectivenesses of the external counter-flow heat exchangers, and coupling between the working fluid and the storage and cryogenic liquid media. Round trip efficiencies around of 35 − 40% have been obtained, internal losses being those with main negative influence on the calculated values. The strong constraints imposed by the pinch point effects and liquid media have been analyzed. The model provides a thermodynamic assessment of the main involved processes and their interplay for a selected arrangement (molten salts, cryogenic fluid, and the charge and discharge power blocks) in order to check parametric strategies for thermodynamic optimization and design. These strategies are based on a reduced set of parameters of the overall installation and without the high computational costs of dynamical models.(ANII); Fondo Sectorial de Energía, Uruguay; contract FSE-1-2018-1-153077

Multicriteria optimization of Brayton-like pumped thermal electricity storage with liquid media

[EN]A multi-objective and multi-parametric optimization of a Pumped Thermal Electricity Storage system based on Brayton cycles is presented by the calculation of different Pareto fronts and the associated Pareto optimal sets for energetic and design analysis, respectively. A large range of internal and external irreversibilities and the thermodynamic properties of the storage media are taken into account. The analysis shows that the heat capacity of the working fluid and the heat capacity of the storage media should be the same in the contact with the hot reservoirs and in the contact with the cold reservoir in the heat pump, but in the contact with the cold reservoir for the heat engine the ratio should be 0.33, this offers information regarding the mass flow increasing significantly the achievable values for the round-trip efficiency, power output and the heat engine efficiency in the discharge process. Optimal values are given in terms of the degree of irreversibilities in the system and a comparison is made with extreme cases of infinite and minimum sizes for the storage system. Round-trip efficiencies in the so-called optimum scale/mass-flow-ratio design point exhibits noticeably larger values compared to previously reported results including the so-called endoreversible limit, where no internal irreversibilities are considered and where the improvement can achieve 49% over the endoreversible case in the most ideal scenario. Explicit numerical values of the maximum round trip efficiency, power output, and efficiency are given for a broad range of both internal and external irreversibilities.Agencia Nacional de Investigación e Innovación (ANII): Fondo Sectorial de Energía (Uruguay), under contract FSE-1-2018-1-153077 Universidad de Salamanca, Spain, under contracts 18.KB.YF/463A.C.01 and 0218463AB01

Motivational Climate, Physical Self-Concept, and Social Relationships in Adolescents in Physical Education Classes: A Systematic Review

The aim of the present study was to provide a comprehensive summary of scientific evidence related with the influence on physical self-concept and prosocial behaviours in adolescents, taking into account the motivational climate generated in Physical Education classes by the teacher. Studies with similar samples have shown that special consideration must be given to the motivational climate of involvement with the task and the coach’s style in support of autonomy in a greater occurrence of prosocial behaviours in the sports context, which shows that the social context is the most important variable in the direction of moral behaviours. Following the application of a search protocol in the Web of Science (WoS) database, 131 articles were initially identified, with eight manuscripts finally being analysed according to previously established criteria for the various stages of the PRISMA checklist. Despite only a relatively small number of articles being available to have rigorously evaluated the topic of interest, analysed studies revealed a direct relationship between motivational climate and physical self-concept. In contrast, no relationship emerged with prosocial behaviour.Consejería de Desarrollo educativo y formación profesional de la Junta de Andalucía (Spain

Aportaciones a la flora del sureste ibérico

New records to the flora of SE Spain.Palabras clave: Corología, plantas vasculares, Murcia, Albacete, España.Key words: Chorology, vascular plants, Murcia, Albacete, Spain

La Dramatización como estrategia didáctica para la inclusión y la expresión oral de los estudiantes de 4° grado B en la asignatura de Lengua y Literatura en el Colegio Público Josefa Toledo #1, municipio de Managua, durante el II semestre del año 2021

La presente investigación, tiene como propósito: “Valorar las estrategias que aplica la docente de 4° grado “B” para mejora el proceso de enseñanza y aprendizaje de los estudiantes en la disciplina de Lengua y Literatura del colegio público Josefa Toledo #1”, de igual forma, se determina la posible solución al problema identificado, con el fin de contribuir al fortalecimiento del proceso enseñanza y aprendizaje del centro de estudio antes mencionado. En el trabajo realizado se encontraron los siguientes hallazgos: se logró con la aplicación de la estrategia la inclusión de los estudiantes en el proceso de enseñanza y aprendizaje a través de la puesta en práctica de la propuesta didáctica como es la dramatización, se reconoció el esfuerzo realizado en los diferentes ensayos que se dieron previos al día de la presentación ante la comunidad educativa. Además se obtuvo la participación de los estudiantes en conjunto con aquellos que no participaban, interactuaron de forma espontánea apoyados de las diferentes lecturas del guion previamente elaborados ya sea de forma individual o colectiva, mostrando el interés en realizar la estrategia, evitando el nerviosismo, miedo o temor ante otros estudiantes de diferentes grados. El informe de investigación se desarrolló desde el enfoque cualitativo, y el tipo de estudio fue descriptivo ya que a partir de las diferentes vivencias en el contexto se muestran detalles sobre el desarrollo de la estrategia propuesta; para la recolección de datos se hizo necesario realizar observaciones y aplicar entrevistas a la docente y estudiantes lo que permitió descubrir o afinar preguntas de investigación en el proceso de interpretación, e identificar la naturaleza profunda de las realidades en el salón de clase, su estructura dinámica así como el comportamiento y manifestación de los protagonistas. Mediante este trabajo se brindó recomendaciones a docente, estudiantes y directores, que ayuden al desarrollo de estrategias antes, durante y al finalizar el desarrollo de las asignaturas con el fin de obtener un proceso de enseñanza y aprendizaje satisfactorio. Palabras claves: Dramatización, expresión oral, inclusión, estrategia didáctic