The exact output regulation problem for Takagi-Sugeno (TS) fuzzy models, designed from linear local subsystems, may have a solution if input matrices are the same for every local linear subsystem. Unfortunately, such a condition is difficult to accomplish in general. Therefore, in this work, an adaptive network-based fuzzy inference system (ANFIS) is integrated into the fuzzy controller in order to obtain the optimal fuzzy membership functions yielding adequate combination of the local regulators such that the output regulation error in steady-state is reduced, avoiding in this way the aforementioned condition. In comparison with the steepest descent method employed for tuning fuzzy controllers, ANFIS approximates the mappings between local regulators with membership functions which are not necessary known functions as Gaussian bell (gbell), sigmoidal, and triangular membership functions. Due to the structure of the fuzzy controller, Levenberg-Marquardt method is employed during the training of ANFIS.
Tin sulfide doped with copper (SnS:Cu) thin films were deposited on glass substrates by the ultrasonic spray pyrolysis (USP) technique at different concentration ratios (y = [Cu]/[Sn] = 0% (undoped), 2%, 5% and 10%). The aim of this work is to analyze the effect of copper on structural, morphological, and optoelectronic properties of SnS:Cu and discuss their possible application as an absorber layer in a solar cell structure proposed which is simulated using SCAPS software. X-ray diffraction (XRD) reveals an orthorhombic structure in the undoped sample and a cubic structure in doped ones. Raman spectroscopy suggests a possible unit cell size change due to the addition of Cu. Scanning electron microscopy (SEM) shows growth in grain density with an increasing y. Image analysis based on second-order features was used to discuss grain distribution. UV-VIS spectroscopy helps to find an increase of bandgap for the doped samples when copper concentration increases, going from 1.82 eV in the doped film y = 2% to 2.2 eV in the 10% doped samples. A value of 3.51 eV was found for the undoped sample y = 0%. A rise in both carrier concentration and mobility but a decrease in resistivity when y is increased was observed through the Hall–Van der Pauw technique. Simulations by SCAPS helped conclude that considering the material thickness, the SnS:Cu compound can be an alternative for implementation in the manufacturing of solar cells as an absorber layer since it is possible to obtain the optoelectronic properties necessary using the UPS economical technique.
In this paper, we present a comparison of classical theory with video analysis techniques to teach kinetic and potential energy of a device with a boomerang effect as an observable and measurable concept. The device can store energy through an elastic band when it rolls downan inclined plane and can release the energy when it rolls on a horizontal surface; hence, the name Boomerang. In theoretical terms, the details of energy charge and discharge processes are analysed with Newton’s laws and Lagrangian method. The experimental results were recorded with cell phone cameras and processed with an open-source video analysis software, called ’Tracker’. The comparison shows relevant concepts about kinetic and potential energy, which can help the student to overcome some of the typical student misconceptions.
This chapter aims to describe the conceptual design and operating mode of an innovative thermoelectric heating unit (THU) prototype in a heating mode. Firstly, the conceptual design of THU system and improvements are described to investigate the effects of design in the thermal performance. Secondly, the THU prototype was compared with a conventional airconditioning system using the typical economic indicators (investment costs, maintenance costs and operational costs). The results indicate that the overall cost of this project was approximately 84,860 Euros, of which 69.27% of the total investment cost are for the engineering costs. By focused on the investment costs of the THU system, the results reveal that the conventional airconditioning system is economically viable than a THU system. The analysis shows that the design has a direct effect on the costs. The maintenance costs show that THU v1.2 prototype is more economically viable in maintenance than the conventional airconditioning system. Likewise, the operational costs show that THU v1.2 had a more stable thermal behaviour than the conventional airconditioning system. Based on the results, the authors concluded that the THU system could be a viable option for a heating room.
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