J. Billerman Robles-Ocampo

• Universidad Politécnica de Chiapas

This study introduces a new method to locate cracks in wind turbine blades using the support vector machine algorithm and the tangential vibration signal measured at the root blade in static conditions. The method was implemented in hardware and experimentally validated on 200 W wind turbine blades. The blade conditions were healthy, and transverse...

In this work, we present experimental and theoretical analysis of the absorbance of the SiNPs that exhibit an interesting behavior on light manipulation through the downshifting mechanism. Silicon nanoparticles (1 nm <radius < 3 nm) were synthesized using a green chemistry method, and characterized to determine its experimental absorbance region, s...

The evaluation of photovoltaic devices must be carried out in laboratories under stable conditions of irradiance, spatial uniformity, and spectral mismatch. Large-scale solar simulators are a reliable option for this. Various designs of simulators have been reported; however, more needs to be deepened in their study. In this work, an experimental i...

Photovoltaic systems for pumping water, based on direct current powered motor pumps, have great application in small rural regions without electrical networks. In addition, these systems provide environmental benefits by replacing fossil fuels. However, these systems reduce their performance due to partial shading, which is magnified by the interna...

In this article, the behavior of the thrust force on the blades of a 10 kW wind turbine was obtained by considering the characteristic wind speed of the Isthmus of Tehuantepec. Analyzing mechanical forces is essential to efficiently and safely design the different elements that make up the wind turbine because the thrust forces are related to the l...

Accurate classification of electromyographic (EMG) signals is vital in biomedical applications. This study evaluates different architectures of recurrent neural networks for the classification of EMG signals associated with five movements of the right upper extremity. A Butterworth filter was implemented for signal preprocessing, followed by segmen...

Wind turbine blades in excessive wind conditions present extreme deflection problems. For this reason, an analysis of the structural response of composite reinforced box beams is developed. For this purpose, reinforced box beams were fabricated to improve the bending strength in the flapwise direction of the wind turbine blades. The box beams were...

We present a study of the efficiency of excitation of surface plasmon polaritons (SPP) at a vacuum-metal interface as a function of the permittivity of the metal. The results of the efficiency, obtained using two types of coupling structures, are presented as maps in complex permittivity space. We find that the efficiency reaches a maximum value of...

The present study examines a hybrid solar drying (HSD) system designed to dry the medicinal plant species, Tithonia diversifolia Gray, via both natural and forced convection. The dryer was built and tested at the Polytechnic University of Chiapas, Mexico. The hybrid solar technology used in the present research comprise a flat solar collector, a so...

The production of biofuels (biogas, ethanol, methanol, biodiesel, and solid fuels, etc.), beginning with cocoa pod husk (CPH), is a way for obtaining a final product from the use of the principal waste product of the cocoa industry. However, there are limitations to the bioconversion of the material due to its structural components (cellulose, hemi...

The partial shading on PV arrays causes power decrease, hot spots, and damage to its components. In addition, the performance of the PV array is reduced for the internal mismatch. This work proposes a novel dynamic, on line, low costs, and automatic method to mitigate these effects. The method considers the mismatch due to partial shading and cell...

Dementia diseases are increasing rapidly, according to the World Health Organization (WHO), becoming an alarming problem for the health sector. The electroencephalogram (EEG) is a non-invasive study that records brain electrical activity and has a wide field of applications in the medical area, one of which is the detection of neurodegenerative dis...

The existence of failures in photovoltaic systems causes energy losses, security problems, and damage to its components. Therefore, it is necessary to develop monitoring systems to improve their productivity, reliability, efficiency, and safety. This work proposes a method for detecting and indicating short-circuit failure and partial shading prese...

The use of wind generators has grown exponentially in recent decades to meet the increasing demand for electricity. With both generator design and generation capability growing, the resulting increases in the size of generators require them to withstand multiple and intense dynamic loads. These loads cause greater stresses, fatigue, torsions, defle...

Wind turbine blades are designed to be thin and flexible elements. Because unstable dynamic behaviour can affect the life of the rotor, it is crucial to understand the instability of non-linear behaviour caused by large deflections. The present study undertakes both a stability analysis of the non-linear response and an experimental validation of a...

In this work the design of a solar dryer for the dehydration of fruits is presented. Banana is used as raw material for analysis and evaluation purposes. The system is supplied with solar energy in the form of (photovoltaic) PV and (photothermic) PT. The PV part of the dehydrator consists of a solar panel, whose energy supplies electrical resistanc...

The present study synthesized powders of bismuth vanadate-alumina (BiVO4-Al2O3) by means of the microwave-assisted hydrothermal method. The powders prepared were characterized by X-ray diffraction, scanning electron microscopy (SEM) and UV–vis diffuse reflectance spectroscopy. The photocatalytic activity of the synthesized powders was determined vi...

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...

This study presents a fault detection and location method for photovoltaic (PV) arrays. One novelty of the method is the use of the different amplitude changes of the alternating current frequency component of the PV array output voltage. Another novelty is the technique used to generate the PV array output voltage. In this technique, the entire ph...

This paper presents a monitoring method for on-line detection and indication of the occurrence of a cutting tool failure during high-speed face milling. The method consists of processing of the vibration signal using a reconfigurable infinite impulse response (IIR) bandpass digital filter and statistical techniques. The healthy tool threshold and t...

We present a reconfigurable system to detect and indicate online and in real time, the cutting tool conditions in high-speed face milling. It consists of a data acquisition system (DAS) and a hardware signal processing (HSP) unit. The DAS acquires and digitalizes the cutting vibration signals generated from machining tests performed under different...

A plane collector was used for dehydration of chamomile (Matricaria Chamomilla L.). The thermal system was built and tested in Chiapas. The proposed system increased the solar thermal energy efficiency, due to it could change his position depending on the season of the year. During the experiment test, 2 kg of fresh chamomile was considered. The ex...

In this work a novel nonlinear model for centerless grinding is presented. The model describes the dynamic behavior of the process. The model considers that the system’s stiffness depends on the existence of lobes in the workpiece surface. Lobes geometry is treated as a polygonal shape and it is demonstrated that the system can be represented as a...

Tool condition monitoring, mainly tool breakage detection for high-speed machining (HSM), is an important problem to solve; however, the techniques or types of sensors applied in other research projects present certain inconveniences. In order to improve tool breakage monitoring systems, a simple, effective, and fast method is presented herein. Thi...

The geometric irregularities that the workpiece presents during the centerless grinding process are a source of dynamic instability and self-excited nonlinear phenomena. The cylindrical surface presents deformations under some cutting conditions; this effect produces two phenomena that cause nonlinear behavior: one is the generation of vertical acc...