Diseño de un manual con procesos didácticos

PDFLa presente investigación fue desarrollada en la carrera de Literatura y español, perteneciente a la Facultad de Filosofía, Letras y Ciencias de la Educación de la Universidad de Guayaquil. El tiempo, en el cual esta se llevó a cabo, tuvo una duración de tres meses aproximadamente, tomado desde que nos dictaron el módulo referente a la teoría y los pasos que se deben seguir para finalizar con el proyecto. Los involucrados en este proceso son: estudiantes, docentes, expertos, y autoridades. El propósito de la investigación es el de resolver la problemática referente a los procesos didácticos que inciden en el desarrollo del análisis literario para obtener estudiantes y profesionales óptimos, el cual se logró, a través de la creación de un manual con procesos didácticos, en el cual se especifican los procesos que se deben seguir en el análisis de una obra. El motivo esencial por la que surge la presente, es debido a la existencia de una necesidad latente que modifique los interaprendizajes en lo que respecta a los análisis literarios. Las fundamentaciones: filosófica, pedagógica, psicológica, andragógica y legal le otorgan validez científica a lo investigado. Entre los métodos empleados resaltan el deductivo, el inductivo, y el científico. Los resultados manifiestan que el 68% de los profesores están muy de acuerdo que los procesos didácticos inciden directamente en el desarrollo del análisis literario. Se concluyó que los procesos didácticos mejorarán la capacidad creativa en los estudiantes y aumentarán su nivel de abstracciónThis research was developed in the race for Literature and Spanish, belongs to the Faculty of Philosophy, Letters and Science Education at the University of Guayaquil. The time in which this took place, lasted about three months, taken since we issued the reference to the theory module and the steps to follow to complete the project. Those involved in this process are: students, teachers, experts and authorities. The purpose of the research is to solve the problems concerning the educational processes that affect the development of literary analysis to obtain optimal students and professionals, which was achieved through the creation of a manual for teaching processes in the which the processes to be followed in the analysis of a work specified. The essential reason why this arises, it is due to the existence of a latent need to modify the interaprendizajes with regard to literary analysis. The foundations: philosophical, pedagogical, psychological, andragogical and give legal validity to scientific investigation. Among the methods used emphasize the deductive, inductive, and scientific. The results show that 68% of teachers strongly agree that learning processes directly affect the development of literary analysis. It was concluded that improve learning processes creative abilities in students and increase their level of abstractio

Thermodynamic Performance of a Brayton Pumped Heat Energy Storage System: Influence of Internal and External Irreversibilities

[EN]A model for a pumped thermal energy storage system is presented. It is based on a Brayton cycle working successively as a heat pump and a heat engine. All the main irreversibility sources expected in real plants are considered: external losses arising from the heat transfer between the working fluid and the thermal reservoirs, internal losses coming from pressure decays, and losses in the turbomachinery. Temperatures considered for the numerical analysis are adequate for solid thermal reservoirs, such as a packed bed. Special emphasis is paid to the combination of parameters and variables that lead to physically acceptable configurations. Maximum values of efficiencies, including round-trip efficiency, are obtained and analyzed, and optimal design intervals are provided. Round-trip efficiencies of around 0.4, or even larger, are predicted. The analysis indicates that the physical region, where the coupled system can operate, strongly depends on the irreversibility parameters. In this way, maximum values of power output, efficiency, round-trip efficiency, and pumped heat might lay outside the physical region. In that case, the upper values are considered. The sensitivity analysis of these maxima shows that changes in the expander/turbine and the efficiencies of the compressors affect the most with respect to a selected design point. In the case of the expander, these drops are mostly due to a decrease in the area of the physical operation region

Thermodynamic optimization subsumed in stability phenomena

[EN]In the present paper the possibility of an energetic self-optimization as a consequence of thermodynamic stability is addressed. This feature is analyzed in a low dissipation refrigerator working in an optimized trade-off regime (the so-called Omega function). The relaxation after a perturbation around the stable point indicates that stability is linked to trajectories in which the thermodynamic performance is improved. Furthermore, a limited control over the system is analyzed through consecutive external random perturbations. The statistics over many cycles corroborates the preference for a better thermodynamic performance. Endoreversible and irreversible behaviors play a relevant role in the relaxation trajectories (as well as in the statistical performance of many cycles experiencing random perturbations). A multi-objective optimization reveals that the well-known endoreversible limit works as an attractor of the system evolution coinciding with the Pareto front, which represents the best energetic compromise among efficiency, entropy generation, cooling power, input power and the Omega function. Meanwhile, near the stable state, performance and stability are dominated by an irreversible behavior

Seasonal thermodynamic prediction of the performance of a hybrid solar gas-turbine power plant

[EN] An entirely thermodynamic model is developed for predicting the performance records of a solar hybrid gas turbine power plant with variable irradiance and ambient temperature conditions. The model considers a serial solar hybridization in those periods when solar irradiance is high enough. A combustion chamber allows to maintain an approximately constant inlet temperature in the turbine ensuring a stable power output. The overall plant thermal efficiency is written as a combination of the thermal efficiencies of the involved subsystems and the required heat exchangers. Numerical values of model input parameters are taken from a central tower installation recently developed near Seville, Spain. Real data for irradiance and external temperature are taken in hourly terms. The curves of several variables are obtained for representative days of all seasons: overall plant efficiency, solar subsystem efficiency, solar share, fuel conversion rate, and power output. The fuel consumption assuming natural gas fueling is calculated and the reduction in greenhouse emissions is discussed. The model can be applied to predict the daily and seasonal evolution of the performance of real installations in terms of a reduced set of parameters.MINECO of Spai

Compartmental Learning versus Joint Learning in Engineering Education

[EN]Sophomore students from the Chemical Engineering undergraduate Degree at the University of Salamanca are involved in a Mathematics course during the third semester and in an Engineering Thermodynamics course during the fourth one. When they participate in the latter they are already familiar with mathematical software and mathematical concepts about numerical methods, including non-linear equations, interpolation or differential equations. We have focused this study on the way engineering students learn Mathematics and Engineering Thermodynamics. As students use to learn each matter separately and do not associate Mathematics and Physics, they separate each matter into different and independent compartments. We have proposed an experience to increase the interrelationship between different subjects, to promote transversal skills, and to make the subjects closer to real work. The satisfactory results of the experience are exposed in this work. Moreover, we have analyzed the results obtained in both courses during the academic year 2018–2019. We found that there is a relation between both courses and student’s final marks do not depend on the course

Thermodynamic model of a hybrid Brayton thermosolar plant

[EN]We present a thermodynamic model for the prediction of the performance records of a solar hybrid gas turbine power plant. Variable irradiance and ambient temperature conditions are considered. A serial hybridization is modeled with the aim to get an approximately constant turbine inlet temperature, and thus to deliver to the grid a stable power output. The overall thermal efficiency depends on the efficiencies of the involved subsystems and the required heat exchangers in a straightforward analytical way. Numerical values for input parameters are taken from a central tower heliostat field recently developed near Seville, Spain. Real data for irradiance and external temperature are taken in hourly terms. Curves for the evolution of plant efficiencies (solar, gas turbine, fuel conversion efficiency, overall efficiency, etc.) and solar share are presented for representative days of each season. The cases of non-recuperative and recuperative plant configurations are shown. Estimations of the hourly evolution of fuel consumption are simulated as well as savings between the hybrid solar operation model and the pure combustion mode. During summer, fuel saving can reach about 11.5% for a recuperative plant layout. In addition, plant emissions for several configurations are presented

On- and off-design thermodynamic analysis of a hybrid polar solar thermal tower power plant

[EN]Concentrated solar power (CSP) is one challenging renewable technology for the production of electricity. Within this concept central receiver solar plants combined with gas turbines are being investigated because of their promising efficiencies and reduced water consumption. Hybrid plants incorporate a combustion chamber in such a way that in periods of low solar irradiance power output can be kept approximately constant and so, electricity production is predictable. An integrated, non-complex solar thermodynamic model of a hybrid gas turbine solar plant is developed employing a reduced number of parameters with a clear physical meaning. The solar subsystem is modeled in detail, taking into account the main heliostats field losses factors as cosine effect, blocking and shadowing, or attenuation. An heliostat field with polar symmetry together with a cavity receiver are considered. The model is implemented in our own software, developed in Mathematica language, considering as reference SOLUGAS solar field (Seville, Spain). Heliostats field configuration is determined for the design point and its associated efficiency is computed. First, an on-design analysis is performed for two different working fluids (dry air and carbon dioxide), for recuperative and non-recuperative modes. A pre-optimization process is carried out regarding the pressure ratio of the gas turbine for different configurations. Some significant efficiency and power rises can be obtained when pressure ratio is adapted for each specific configuration and working fluid. Maximum achievable plant overall efficiency is 0.302 for both fluids in the recuperative mode, taking a pressure ratio of 7 for dry air and 16 for carbon dioxide. In non-recuperative configurations maximum overall efficiency is obtained for dry air, about 0.246. Moreover, a dynamic study is performed for four representative days of each season. Then, efficiencies and solar share are plotted against time. In addition, fuel consumption and greenhouse emissions are computed for all seasons

Optimization induced by stability and the role of limited control near a steady state

[EN]A relationship between stability and self-optimization is found for weakly dissipative heat devices. The effect of limited control on operation variables around an steady state is such that, after instabilities, the paths toward relaxation are given by trajectories stemming from restitution forces which improve the system thermodynamic performance (power output, efficiency, and entropy generation). Statistics over random trajectories for many cycles shows this behavior as well. Two types of dynamics are analyzed, one where an stability basin appears and another one where the system is globally stable. Under both dynamics there is an induced trend in the control variables space due to stability. In the energetic space this behavior translates into a preference for better thermodynamic states, and thus stability could favor self-optimization under limited control. This is analyzed from the multiobjective optimization perspective. As a result, the statistical behavior of the system is strongly influenced by the Pareto front (the set of points with the best compromise between several objective functions) and the stability basin. Additionally, endoreversible and irreversible behaviors appear as very relevant limits: The first one is an upper bound in energetic performance, connected with the Pareto front, and the second one represents an attractor for the stochastic trajectoriesJunta de Castilla y León, SA017P17 ; Universidad de Salamanca, 2017/X005/1 ; National Natural Science Foundation of China, 1140503

Energetic Self-Optimization Induced by Stability in Low-Dissipation Heat Engines

[EN]The local stability of a weakly dissipative heat engine is analyzed and linked to an energetic multiobjective optimization perspective. This constitutes a novel issue in the unified study of cyclic energy converters, opening the perspective to the possibility that stability favors self-optimization of thermodynamic quantities including efficiency, power and entropy generation. To this end, a dynamics simulating the restitution forces, which mimics a harmonic potential, bringing the system back to the steady state is analyzed. It is shown that relaxation trajectories are not arbitrary but driven by the improvement of several energetic functions. Insights provided by the statistical behavior of consecutive random perturbations show that the irreversible behavior works as an attractor for the energetics of the system, while the endoreversible limit acts as an upper bound and the Pareto front as a global attractor. Fluctuations around the operation regime reveal a difference between the behavior coming from fast and slow relaxation trajectories: while the former are associated to an energetic self-optimization evolution, the latter are ascribed to better performances. The self-optimization induced by stability and the possible use of instabilities in the operation regime to improve the energetic performance might usher into new useful perspectives in the control of variables for real engines.University of Salamanca Contract No. 2017/X005/1 ; Junta de Castilla y León Project No. SA017P17 ; National Natural Science Foundation of China (No. 11405032)