Evapotranspiración del cultivo de granado por balance de energía

Evapotranspiration is a key element in calculating the surface energy balance, wáter balance and crop water stress and crop yield determination. However, it´s direct measurement or estimation is frequently complicated, since the diversity and complexity of the factors acting in this physical process. (morphological, physiological and soil factors). SEBAL (Surface Energy Balance Algorithm for Land) estimates ET based on satellite images, using the principles of surface energy balance producing excellent results as reported in several studies of different scientist authors; minimizing the cost and time for the ET determination for large vegetation zones. The objective of this research work was to estimate the potential evapotranspiration for the pomegranate crop in a commercial farm, located in Gomez Palacio, Durango, Mexico, by SEBAL using Landsat 8 satellite images during the crop cycle 2016. The results were validated with estimates of ET by the FAO 56 method, obtaining a Willmott concordance index of 0.96, which means good estimation precision.

Simulación del comportamiento térmico en exteriores urbanos correlacionando las variables de calor antropogénico vehicular y orientación

The complexity of the urban environment and its undeniable connection with the energy balance equation opens the doors for researchers to understand phenomena such as the Urban Heat Island (UHI). The least studied factor of the UHI is vehicular anthropogenic heat. Using Computational Fluid Dynamics (CFD) software, the aim is to understand the thermal environment within an urban canyon, based on two variables, the heat produced by the vehicle combustion engine and the orientation of the street (North - South and East -West). The analysis of the correlation of these variables is based on the information obtained from the simulation in different height strata, considering constant values such as direct radiation, diffuse radiation, emissivity and absorptivity of materials and a fixed temperature for the bonnet or hood of the car, altering the number of automotive vehicles and the orientation to examine the different patterns of the thermal profiles. The research opens the way to understand this phenomenon and be considered in simulations for the energy efficiency of buildings, since it directly impacts the facades of buildings and the determination of passive and active cooling techniques.

Mecanismo Diseñado y Simulado Virtualmente

Objectives: To show a process to synthesize and analyze a crank mechanism oscillator function generator. Simulate it in a virtual reality environment, without losing its physical characteristic. Evaluate deviations between analytically desired and virtually obtained. Methodology: Using the analytical method described by Hartenberg and Denavit, a graphic package and an electronic spreadsheet; knowing the angle of rotation of the crank, the angular reference position of the crank, the displacement of the oscillator, the extreme values of the independent variable and the function; precision positions, link lengths, eccentricity and oscillator reference position were determined. The links were generated, the mechanism was assembled, analyzing fifteen of its positions. Of the infinite number of existing solutions, five were synthesized. For each solution that justify it, the deviation of the generated function was evaluated with respect to the desired one. Contribution: The friendly, fast, safe, accurate and parametric process was demonstrated; modifying the inputs and checking the update of the outputs, therefore it is a contribution to the scientific progress of the area.

Prototipo de estación agrometeorológica de monitoreo de datos climatológicos

One of the limitations in agricultural production in the State of Guerrero is the various events of meteorological disasters, with the case of recurrent drought, hurricane winds, high rainfall that cause floods and very high daytime temperatures that directly affect annual crops (corn, beans and sorghum) and perennials (mango, lemon, avocados). In the entity there is little accurate and timely agroclimatic information that serves as a determining factor in the decision-making process of production processes. The present study has the purpose of developing a prototype of low-cost agrometeorological station. The data can be monitored via the Internet 24 hours a day, from the climate variables, such as: environmental temperature, relative humidity, rainfall, solar and ultraviolet radiation, wind speed and direction. With the storage of these climatological data, information will be obtained that contributes to the prevention of diseases and pests in the cultivation of corn, fruit trees and vegetables of economic importance. Reason for which the National Institute of Forestry, Agriculture and Livestock Research and the Technological University of the North Region of Guerrero, are joining forces in the development of a prototype of agrometeorological station.

Modelado y simulación CFD de un sistema de refrigeración para el almacenamiento de vacunas contra la Influenza Estacional

It is very important to carry out vaccination campaigns in the marginalized areas of our country, because they are more vulnerable to contracting diseases, but to do the appropriate containers are needed so that they arrive with their properties and to protect each person. The Seasonal Influenza vaccine is transported in portable refrigerators at a temperature of 2 and 8 ° C, and the storage time is within 3 and 7 days for the first and 12 to 36 hours for the second. This paper presents the modeling and simulation by Computational Fluid Dynamics (CFD) of a refrigerated system, from thermoelectric cells, for the storage of influenza vaccines. The results show the temperature distribution within the refrigerated system and the transfer of heat in each container element, as well as the most appropriate arrangement to keep each vaccine to the optimal storage temperature. Being able to count on portable systems that allow the optimal transfer of vaccines keeping refrigerated in a constant way would have a positive impact on the health of people who live in marginalized areas.

Propiedades ópticas y estructurales de las películas de óxido de silicio rico en silicio obtenidas por la técnica HFCVD

In this work we present the results of the analysis obtained from the deposit and characterization of thin films of silicon rich oxide (SRO). The films were obtained by hot filament chemical vapor deposition (HFCVD) technique, such films were deposited on silicon substrates p-type. The deposit of thin films was realized considering different distances from source to substrate (DFS) which were 3, 4, 5 and 6 mm. The quantity of precursors (SiO2) was controlled by the distance from the filament to the source, which was 6 mm for this work, the filament was held at 2000°C. A constant 3-minute deposit time was maintained, and the hydrogen flow level was 10 sccm. The films thickness was obtained by using the profilometry technique, the thickness range was from 200 to 600 nm. The vibrational molecular modes of the SRO films were obtained by Fourier Transform Infrared Spectroscopy (FTIR). The films of 3 mm DFS exhibit an optical transmittance of 90%. The optical energy band gap of the thin films varies from 2.2 to 3.3 eV. When an annealing process at 1000°C was carried out for one hour, the SRO films increase their photoluminescence by an order of magnitude approximately.

Simulación del Modelo Matemático de la Cinemática Diferencial de Robots Seriales Planos Configuración RRR y RPR

This article presents the model and simulation of the serial robot configurations of the types RRR and RPR, applying the theories of differential kinematics, to obtain the representation of its mathematical model (Jacobian matrix) and its simulation. The differential kinematics in robotics is the relationship between vector spaces, so it is possible to make the velocity map in the joint space in the end effector workspace. We present the differential kinematic model that is obtained from the position kinematics by differentiation techniques and with the help of the asymmetric matrix we obtain the information that is part of the Jacobian matrix, which allows us to know the velocities of the joint variables as a function of linear and angular velocity in the end effector and vice versa. The simulation of the manipulators is carried out validating the mathematical differential model; through the validation of the differential kinematics of serial chains it is possible to apply the procedure to complicated manipulator robots. The method presented here is the basis of a useful tool for solving complex robots, as in the case of redundant, parallel and hybrid serial manipulator robots.

Metodología para el Modelado y simulación de pruebas de fatiga en álabes de aerogeneradores de baja potencia

This article presents the design, simulation and fatigue analysis of various aerodynamic profiles used in low power wind turbines. For this purpose, the model of a blade of a horizontal axis wind turbine with a nominal power of 5 kW is developed. The analysis of the lift, drag and power coefficients of the aerodynamic profiles was carried out with the XFLR5 software. The methodology used for the blade design is based on the interactions and convergence method called BEM. Also, to simulate the structural and aerodynamic part of the element, the QBlade program was used. With the main objective of ensuring that the fatigue safety factors mentioned in the IEC 61400 standard are achieved, the Simplified Load Model was applied. The maximum fatigue value of 21,421.66 N and the maximum flapwise moment value of 698.41 Nm were obtained.

Sobre la síntesis óptima de mecanismos

In the engineering design process, it is of particular relevance the problem statement that has to be solved to guarantee an optimal design. There is no general rule for this, and in the particular case of the synthesis of flat mechanisms, the solution strongly depends on the problem statement for the design or mechanism synthesis. The object this paper is presenting one proposal at synthesis problem of a four-bar flat mechanism for cartesian trajectory tracking. The mechanism synthesis problem is stated as a nonlinear optimization problem with non linear constraints. Four different approaches are considered in order to demonstrate the impact of the considered statement of the optimization problem for its solution. The solution of the four optimization problems is obtained by means of numerical calculations using genetic algorithms. The numerical results of the four optimization problem statemens are compared under fair circumstances and they depict the great influence of the initial problem statement for its solution.

Convergencia de la trayectoria lingüística en el espacio de estados de un Controlador Difuso aplicado a un Sistema No Lineal

This article presents the design of a fuzzy controller to stability analysis base on the convergence of the linguistic trajectory in the state of space, for an inverted car-pendulum system, the fuzzy controller is of the Mamdani type and, it consists of 25 rules, 3 input variables and each one is composed of five memberships functions. The inverted car-pendulum system is represented by a non-linear model, which is obtained from a linearized equivalent model under the consideration of small oscillations. Results are validated against a PID control base on the trajectory on the phase plane to evaluate the efficiency and effectiveness of the fuzzy controller. The dynamic behavior of the system of both controllers is obtained with a unit impulse input, the simulation of the control system is developed on the MATLAB / SIMULINK software using the FUZZY LOGIC TOOLBOX, which allows to perform test and simulations, and also it shows results of graphic form.