Artigos - Engenharia Elétrica - FEG

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Expert system: use of CLIPS software to evaluate solar energy for residences and businesses
(2023-12-01) David, Thamyres Machado [UNESP]; de Souza, Teófilo Miguel [UNESP]; Rizol, Paloma Maria Silva Rocha [UNESP]; Universidade Estadual Paulista (UNESP)
The use of energy is important in all sectors, considered essential in industrial, commercial and residential activities. In view of this and the environmental problems caused by energy sources with fossil fuel origin, methods of energy production with renewable sources have been increasingly addressed. Studies that estimate the impact and evaluations of solar technologies in homes are scarce. In this sense, the applied method addresses the use of CLIPS for the development of a knowledge base for preliminary diagnosis and evaluation of solar energy for homes and businesses, thus obtaining a prototype of an expert system, the method also approaches the use of artificial intelligence with a heuristic characteristic and its target audience is people with little or no knowledge in the area, thus contributing to the social impact. As a result, the developed programming helps people with little or no knowledge about solar energy and its residential application to have access and thus verify the applicability. It is worth noting that this is the first empirical study carried out in Brazil, a country of crucial importance for the development of solar energy.
The Evolution of Knowledge and Trends within the Building Energy Efficiency Field of Knowledge
(2022-02-01) Cristino, Talita Mariane [UNESP]; Neto, Antonio Faria [UNESP]; Wurtz, Frédéric; Delinchant, Benoit; Universidade Estadual Paulista (UNESP); G2Elab
The building sector is responsible for 50% of worldwide energy consumption and 40% of CO2 emissions. Consequently, a lot of research on Building Energy Efficiency has been carried out over recent years, covering the most varied topics. While many of these themes are no longer of interest to the scientific community, others flourish. Thus, reading trends within a field of knowledge is wise since it allows resources to be directed towards the most promising topics. However, there is a paucity of research on trend analysis in this field. Therefore, this article aims to analyse the evolution of the Building Energy Efficiency field of knowledge, identifying the recurrent themes and pointing out their trends, supported by statistical methods. Such an analysis relied on more than 9000 authors’ keywords collected from 2000 articles from the Scopus database and classified into 30 topics/themes. A frequency distribution of these themes enabled us to distinguish those most published as well as those whose academic interest has cooled down. This field of knowledge has evolved over three distinct phases, throughout which, eight themes presented an upward trend. These findings can assist researchers in optimising time and resources, investigating the topics with growing interest, and possibilities for new contributions.
Guidelines for efficient and sustainable energy management in hospital buildings
(2021-12-20) Borges de Oliveira, Karine [UNESP]; dos Santos, Eduardo Ferro; Neto, Antonio Faria [UNESP]; de Mello Santos, Vitor Homem [UNESP]; de Oliveira, Otávio José [UNESP]; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP)
The increasing global consumption of energy and its negative impacts on the environment has been an issue discussed both by academics and practitioners, including in the health sector. Hospitals are major consumers of energy, which leads to increased operating costs, decreased competitiveness, and negative environmental impacts. Energy management in hospitals must be understood as a way to contribute to environmental sustainability and as a way to improve competitiveness. Therefore, the objective of this paper is to propose guidelines for efficient and sustainable energy management in hospitals, developed based on the literature review, the challenges faced and the good practices of sustainable energy management in the hospitals studied, the cross analysis of the case studies, and the authors' expertise. As a result, the eight proposed guidelines are related to culture change, energy consumption management, energy management standard, purchase of renewable energy, green technologies, sustainable hospital buildings, social responsibility programs focused on energy use, and sustainable energy public policies. These guidelines contribute in an applied/managerial way to help managers of public and private hospitals overcome the challenges of energy management and contribute to UN's SDG7 due to its potential to improve energy efficiency and environmental performance, therefore, being a movement towards clean energy. This study also theoretically/scientifically contributes to the academic debate since the empirical findings found in the hospitals studied and the proposition of guidelines deepen and expand the key elements identified in the literature on efficient energy management in hospitals, providing the basis for developing new research on the subject.
Using design of experiments in the evaluation of the microstructural characterization parameters with the LePera reagent in a multiphase steel
(2021-08-01) De Faria Neto, Antonio Dos Reis [UNESP]; Fukugauchi, Cristina Sayuri; Dos Santos Pereira, Marcelo [UNESP]; Universidade Estadual Paulista (UNESP); São José Dos Campos
The performance of multiphase steels is closely related to their microconstituents. Thus, the characterization and effective control of the microstructure of these materials are crucial, and chemical attack processes are essential for this to occur. In this context, this study sought to employ the Taguchi method to evaluate the chemical etching process with the LePera reagent in order to investigate the influence of different process variables, in addition to the interactions between them, on the quality of the image obtained. The variables analyzed were: concentration of picral (CP) and sodium metabisulfite (CSM) solution, pre-attack (PA), drying mode (DM) and attack time (AT). in addition to the relative humidity and temperature of the environment. Therefore, a quality index (QI) was suggested for the images obtained, which, together with the analysis of variance, indicates the best route for microstructural characterization of TRIP800 steel (CP-4.0%; CSM-0.5% ; PA-No; DM-Natural; AT-25s; . Temperature ( C): 15I - -25 and Relative humidity (%): 55I - -90). In addition to indicating the variables that most influence the process. The influence of noise factors (temperature and relative humidity) was also proven.
Initial study of an alternative technology aimed at measuring and controlling the flow rate in air conditioning ducts
(2021-01-01) Testi, Andrei; Marcelino, Marcio Abud [UNESP]; Lotufo, Francisco Antonio [UNESP]; de Souza, Teófilo Miguel [UNESP]; University of Taubate – UNITAU; Universidade Estadual Paulista (UNESP)
This paper states that there might have around 1000 small size business jets (until nine occupants) flying across the world equipped with flow control and regulating shut-off valves that uses hot wire anemometer devices to regulate massflow rate from the bleed airflow to supply the air-conditioning and pressurization systems. However, these valves present low reliability in the field. The purpose of this paper is to evaluate the implications of a flow control and regulating shut-off valve with a non-intrusive airflow measurer device under the perspective of fluid mechanics. The Venturi technology that is commonly used technology, given its construction simplicity, precision, and broad use in the industry, is selected to substitute the flow control and regulating shut-off valves with hot wire anemometer of the mentioned small size business jets applications. This paper has adopted a numeric simulation approach utilizing the ANSYS-CFX computational fluid dynamics software to verify both the differential pressure at the Venturi device and its correspondent mass flow rate to supply the air conditioning systems of some small size business jets, considering the mass-flow rate as requested by the FAA certification requirement (0.55 lb/min per occupant). This paper shows that a mass-flow rate control and regulating shut-off valve with a Venturi device, of 1 inch and β of 0.67, is compliant with the minimum fresh air flow requested by the FAA certification requirement to operate in some small size business jets. Besides that, the software ANSYS-CFX is also effective to support the engineering analysis of flow field characteristics inherent to the applications of internal compressible flow. The numeric simulation utilizing the ANSYS-CFX computational fluid dynamics software outlined herein can lay the basis for further research related to the design of a flow control and regulating shut-off valves with a Venturi device.
Building new paths for responsible solid waste management
(2021-07-01) Espuny, Maximilian [UNESP]; Faria Neto, Antonio [UNESP]; da Motta Reis, José Salvador [UNESP]; dos Santos Neto, Sérgio Tenório [UNESP]; Nunhes, Thais Vieira [UNESP]; de Oliveira, Otávio José [UNESP]; Universidade Estadual Paulista (UNESP)
The amount of solid waste produced across the planet in the past decade was 1.3 billion tons (1.2 kg/year per person). Also, the significant number of publications on solid waste management (SWM) draws attention to the importance of discussing the topic to improve public health and to mitigate environmental impacts. The objectives of this article are to identify the state of the art and the scientific gaps on SWM and to propose a framework to promote it in the coming years. For this, a content analysis was carried out with the support of a bibliometric study, considering articles published in the Scopus database. The field of SWM study was classified into 12 different themes, and from this division, it was sought to identify the evolution of each of them between the 2005 and 2018 period. Content analysis and bibliometric study indicate that thermal and biological treatments are a promising trend to improve the performance of SWM. Its most important applied contribution is the generation of qualified information about SWM that can support the decision-making of public and private managers to reduce environmental impacts and improve life in urban spaces. The main academic contribution of the paper is the articulation of the most important themes on SWM, identifying the individual impact of each one of them in this field of study and the indication of the scientific trends that should guide the development of future research.
The Positive Impacts of Sustainability in the Community
(2021-01-01) Martins De Moraes, Thiago Matheus [UNESP]; Jacintho, Felipe Fernandes; Camargo, Gabriela Maia [UNESP]; Adami, Jose Feliciano [UNESP]; Dias, Rubens Alves [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Estadual de Campinas (UNICAMP)
The Brazilian electric power matrix has always been profoundly dependent on hydroelectric power plants. According to the 2019 decennial plan by the Energy Research Company (EPE, in Portuguese), 60% of the instal led power from Brazil's electrical system is in large hydroelectric plants, and 4% is in small hydroelectric plants. Recently, however, between 2014 and 2016, the most representative Brazilian federative unit, in terms of gross domestic product, suffered a severe hydroelectric crisis, which highlighted discussions about the future of power generation.
Saving energy by changing the tariff structure and applying flag fees in Brazil
(2018-12-03) Touma, Daniela Wolter Ferreira; Cassula, Agnelo Marotta [UNESP]; University of South Alabama; Universidade Estadual Paulista (UNESP)
Trying to mitigate the crisis in the energy sector in the last few years, the Brazilian government implemented tariff flags, which increase the power bills in several areas. Alternative analyses of the power consumption may suggest ways to reduce losses and the monthly power bill. This paper identifies the different strategies of power billing in a residential and a small industrial consumer in Brazil. It uses power measurements in the two different consumers in detail to propose improvements in the consumption which could lead not only to decrease the power bill but also to relieve the power energy system.
Education for energy efficiency through an educational game
(2013-12-01) Mesquita, Leonardo [UNESP]; Monteiro, Marco Aurélio A. [UNESP]; De Sena, Galeno J. [UNESP]; Ninomiya, Maurício P. [UNESP]; Da Costa, Charles A. [UNESP]; Universidade Estadual Paulista (UNESP)
This paper presents an assessment of an educational game for teaching the efficient use of electricity. Developed with Adobe Flash®, it is a virtual board game where participants choose a car that starts the path and reaches the same final goal, going through a number of track steps defined in terms of a dice that each player rolls in turn. The car moves if the participant is able to correctly answer a question that is randomly generated by the software. The objective of the game is to answer questions related to energy efficiency promoting a healthy and attractive learning process for participants on concepts related to energy efficiency such as: the rational use of energy, the basic concepts of forms of energy generation, among others. The main objective of this paper is to assess the impact of the application of this virtual game in the teaching and learning process of high school students. Therefore, the game was applied in the discipline of physics in a class of junior high public school in the state of São Paulo. Initially, the class that had 43 students was divided into 10 groups of 4 students, and 1 group of 3 students. Each student group competed with one another. The idea was that each of them should indicate a student who was the representative of this group until only 4 group leaders were selected for the finals. At this stage, each student could interact with a group of up to ten students that acted as advisers. The adopted assessment process is based on the model proposed by Savi [7]. Then, at the end of the game, the students answered a prepared questionnaire based on the model proposed by Savi. According to Savi, although there are significant studies that show the importance of educational games for the process of cognitive development and learning concepts of students, there are few papers that present forms of assessing the potential of these resources. Thus, the assessment criteria proposed by Savi are based on the model of training evaluation by Kirkpatrick [3], taken as a reference to measure the efficiency of processes of continuing education courses for professionals. The authors assert that the metric of the evaluation proposed to assess the game is based on the first level of the model proposed by Kirkpatrick. © 2013 IEEE.
Stepping motor driven constant-shear-rate rotating viscometer
(2004-10-08) De Lucena, Samuel E.; Kaiser, Walter; Universidade de São Paulo (USP)
Despite the frequent use of stepping motors in robotics, automation and in a variety of precision instruments, they can hardly be found in rotational viscometers. This paper proposes the use of a stepping motor to drive conventional constant-shear-rate laboratory rotational viscometer, in order to avoid the use of velocity sensor and gearbox and, thus, simplify the instrument design. To investigate this driving technique, a commercial rotating viscometer has been adapted to be driven by a stepping motor, which is controlled via PC. Special circuitry has been added in order to microstep the stepping motor at a selectable step size, and to condition the torque signal. Tests have been carried out using the prototype to produce three flow curves for a standard Newtonian fluid (920 mPa.s at 25°C) but employing a different microstep size for each of them, within the shear rate range from 50 s-1 to 500 s-1. The results indicate the feasibility of the proposed driving technique.
A CMOS class-AB instrumentation amplifier for micropower applications
(1998-12-01) De Lima, Jader A. [UNESP]; Silva, Sidnei F. [UNESP]; Universidade Estadual Paulista (UNESP)
A simple micropower CMOS instrumentation amplifier comprising a double-input Gm-stage and a low-distortion class-AB output stage is presented. The amplifier was designed according to micropower techniques to achieve high values of low-frequency differential-gain and common-mode rejection and integrated in a digital-oriented 0.7μm n-Well CMOS process. For a bias current of 130nA, amplifier standby power consumption is 26μW. Measurements revealed good characteristics at DC and low frequencies such as A dm=87dB and CMRR=-137dB. For a compensation capacitor of 4.5pF, it was found ΦM=73° and a unity-gain frequency of 47KHz. Offset voltage was below 0.7mV, typically. Resistive loads down to 10KΩ can be driven with a 1.3V peak-to-peak swing. Overall linearity is represented by a THD of - 42.9dB. Although bandwidth limitation occurs due to small bias currents, the proposed amplified can be advantageously employed in many control and low-frequency signal processing. © 1998 Editions Frontieres.
Power performance evaluation of an electric home fan with triac-based automatic speed control system
(2009-12-01) Bianchi, Inácio [UNESP]; Filho, Paulo Magalhães [UNESP]; Sobrinho, José Pinto Ferreira [UNESP]; Universidade Estadual Paulista (UNESP)
In order to provide a low cost system of thermal comfort, a common model of home fan, 40 cm diameter size, had its manual four-button control system replaced by an automatic speed control. The new control system has a temperature sensor feeding a microcontroller that, by using an optic coupling, DIAC or TRIAC-based circuit, varies the RMS value of the fan motor input voltage and its speed according to the room temperature. Over a wide range of velocity, the fan net power and the motor fan input power were measured working under both control system. The temperature of the motor stator and the voltage waveforms were observed too. Measured values analysis showed that the TRIAC-based control system makes the fan motor work at a very low power factor and efficiency values. The worst case is at low velocity range where the higher fan motor stator temperatures were registered. The poor power factor and efficiency and the harmonics signals inserted in the motor input voltage wave by the TRIAC commutation procedure are correlated.
Portable MP3 player as low-cost data logger
(2009-12-01) De Lucena, Samuel E. [UNESP]; Universidade Estadual Paulista (UNESP)
Non-audio signals have been recorded in the flash ROM memory of a portable MP3 player, in WAV format file, to examine the possibility of using these cheap and small instruments as general-purpose portable data loggers. A 1200-Hz FM carrier modulated by the non-audio signal has replaced the microphone signal, while using the REC operating mode of the MP3 player, which triggers the voice recording function. The signal recovery was carried out by a PLL-based FM demodulator whose input is the FM signal captured in the coil leads of the MP3 player's earphone. Sinusoidal and electrocardiogram signals have been used in the system evaluation. Although the quality of low frequency signals needs improvement, overall the results indicate the viability of the proposal. Suggestions are made for improvements and extensions of the work.
Automatic tuning of linearly tunable high-Q filters
(2002-01-01) Karşilayan, Aydin I.; Huang, Sung-Ling; De Lima, Jader A. [UNESP]; Texas A and M University; Universidade Estadual Paulista (UNESP)
A new tuning scheme for linearly tunable high-Q filters is proposed. The tuning scheme uses the phase information for both frequency and Q factor tuning, therefore no relationship between filter's passband magnitude and Q is required. To reduce the simulation overhead, operation of the tuning circuit is verified on a symbolic filter whose parameters were derived from the transistor level circuit. At 10 MHz, for a desired Q of 20, simulated frequency and Q tuning errors are 0.3% and 1.7%, respectively.
Smart & Integrated Management System - Smart Cities, Epidemiological Control Tool Using Drones
(Ieee, 2020-01-01) Rangel, Rodrigo Kuntz; Freitas Jr, Joacy L. [UNESP]; Souza, Teofilo Miguel de [UNESP]; IEEE; IBRV Inst Res & Dev; BRV UAV & Flight Syst BRVANT; Universidade Estadual Paulista (UNESP)
This paper describes the development of a real application using Drones over urban regions to help the authorities at epidemiological control through a disruptive solutions based on a customizable Smart & Integrated Management System (SIGI), devices and software based on the Enterprise Resource Planning (ERP) concept. Compound by management software, Drones and specific IoT devices, both referred to as sensors, the sensors collect the data of the interest areas in real time, creating a specified database. Based on the data collected from the interest areas, SIGI software has the ability to show real-time situational analysis of these areas and allows that the administrator can optimize resources (material and human) improving the efficiency of resource allocation in these areas. In addition to the development of the management software, the development of sensors to collect the information in the field and update these information to the database of the management software, are considered. The sensors will be recognized as IoT devices for the collection of meteorological data, images and command / control Drones. Initially the system will be customized, using an Artificial Intelligence tool, to collect data and identify the outbreaks of the dengue mosquito, zika and Chikungunya, nominee by risk areas. After the definition of the potential risk areas, in a complementary way, a totally customized Drone will be used to map these areas of interest, generating aerial photographs, identifying and geotagging the potential targets, which will allow the agents to identify potential mosquito breeding sites. After the identification of breeding areas, the next step will be the effective combat of the vectors, using the Drones to fly over the areas of interest, where biological defenses will be dropped over the targets to combat mosquitoes. Due some Drone flight restrictions over the cities, the whole process will be monitored by a situation room, that will be able to control the Drone remotely, access the air space controller, reads the sensors installed in the city (field), that will measure, for example, rainfall through weather stations installed in risk areas and subsequently processed by Intelligent System Integrated Management (SIGI), which will result to the information public official reflecting the situational analysis of the areas, which will enable a better management of available resources, helping the public agent, preventively in the decision making.
Groundwater and the water-food-energy nexus: The grants for water resources use and its importance and necessity of integrated management
(Elsevier B.V., 2021-10-01) Moraes-Santos, Eliana Cristina [UNESP]; Dias, Rubens Alves [UNESP]; Perrella Balestieri, Jose Antonio [UNESP]; Universidade Estadual Paulista (UNESP)
According to the Brazilian National Water Resources Policy, water is a limited public good, and its management involves the participation of public authorities, users, and communities. This paper analyzes data on groundwater concession and uses in five Brazilian municipalities, located in the northeastern region of the Paraiba do Sul River Basin. Data were analyzed to associate aquifer systems and groundwater use with electricity consumption of the water supply systems and food production, in the perspective of the water-food-energy nexus. This analysis aimed to quantify the exploited water flows and if it is adequate with the capacity of the aquifers. For data analysis and interpretation, statistical techniques were used, which allowed structuring, organizing, and associating the information. The results indicate that, among the regional aquifer systems, the Cacapava System is the most explored in terms of groundwater abstraction, with an average of 9769 m(3)/h, of which only 1331 m(3)/h is used for public supply and 8456 m(3)/h for private use. One finding of this research was to verify that just one of the municipalities studied makes public the use of groundwater abstraction, with consequences in public policy and alerting to the need for adequate inspection in the areas of underground well-drilling for non-contamination and better maintenance of aquifer systems. The results highlight the water-food-energy nexus in the study area, indicating that municipalities with large rice cultivation areas use or store most of the water resources for agricultural use. Promoting new sustainable actions and achieving the Sustainable Development Goals requires integrated management outside the traditional sectors and water-food-energy nexus approach.
MODELOS COMPUTACIONAIS FUZZY PARA AVALIAR EFEITOS DA POLUIÇÃO DO AR EM CRIANÇAS
(Sociedade de Pediatria de São Paulo, 2017-11-13) David, Gleise Silva [UNESP]; Rizol, Paloma Maria Silva Rocha [UNESP]; Nascimento, Luiz Fernando Costa [UNESP]; Universidade Estadual Paulista (Unesp)
The use of technology for the growth of the sustainability concept inside community
(2020-10-29) De Moraes, Thiago Matheus Martins [UNESP]; De Lima Viveiros, Henrique Amon [UNESP]; Jacintho, Felipe Fernandes; Camargo, Gabriela Maia [UNESP]; Adami, Jose Feliciano [UNESP]; Dias, Rubens Alves [UNESP]; Universidade Estadual Paulista (Unesp); Universidade Estadual de Campinas (UNICAMP)
The Ponto Iluminadoinitiative consists of a wide range of technical actions in the areas of clean energy generation, energy efficiency, solid waste management and water savings together, creating a virtuous cycle of sustainability within the Saõ Paulo State University-Guaratingueta campus. The development of this model campus serves as a large laboratory for the entire local community and, also, having already received visitors from all regions of the country; in order to disseminate the concepts of sustainability and create a more conscious society regarding the rational use of natural resources. This project, which achieves 12 of the 17 Sustainable Development Goals, aims to change actions and customs through education and improvement of knowledge, acting, especially, in the conscious education of children and young people. Thus, creating a society capable of growing and developing with greater care for the environment and being capable of a better managing of its natural resources.
Monitoring the process mean with an ATTRIVAR chart
(2020-01-01) Costa, Antonio Fernando Branco; Faria Neto, Antonio [UNESP]; Federal University of Itajubá (UNIFEI); Universidade Estadual Paulista (Unesp)
In this article, we propose an ATTRIVAR chart to control the process mean. With the ATTRIVAR chart, the sampling is performed in two stages, collecting attribute and variable sample data from the same sample (attribute plus variable data–ATTRIVAR). That is, if the first m items of the sample fail to pass the go gauge test, or they pass the no-go gauge test, the sampling moves on to stage two, where the quality characteristic X of the first m and the remaining n-m items of the sample is measured. Otherwise, the sampling is interrupted and the process is declared to be in control. The number of tested items, if one, or two, or as many as m, is only known after the completion of the first stage. At the second stage, the (Formula presented.) value is computed and used to decide the state of the process. It is worthwhile to stress that the go/no-go gauge test truncates the X distribution and, because of that, the mathematical development to obtain the (Formula presented.) distribution is not trivial. The ATTRIVAR chart signals faster than the Double Sampling (Formula presented.) chart and, more important than that, it is simpler to use because the go/no-go gauge test reduces the frequency with which the quality characteristic X of the sample items is measured. The ATTRIVAR chart is also faster and simpler than the mixed chart. With the mixed chart, the sampling is also performed in two stages; the difference is that all items of the sample are always submitted to the go/no-go gauge test before deciding to go to stage two, where the (Formula presented.) value is computed.
Spaces of interdisciplinary in/congruity: the coming together of engineers and social scientists in planning for sustainable urban environments
(2020-01-01) Hadfield-Hill, Sophie; Horton, John; Kraftl, Peter; Balestieri, José Antônio Perrella [UNESP]; Vilanova, Mateus Ricardo Nogueira [UNESP]; Dias, Rubens Alves [UNESP]; Soares, Paulo Valladares [UNESP]; University of Birmingham; University of Northampton; Universidade Estadual Paulista (Unesp)
In the context of a globalised interdisciplinary moment, where boundary-crossing research collaborations are valorised, this paper considers encounters between multidisciplinary researchers. Presenting empirics and reflections from an international project where social scientists and engineers sought to collaborate, communicate and address complex challenges associated with sustainable urban development, we question a series of assumptions about interdisciplinary research. Importantly, we pause to consider the practical implications of doing this work. In particular, we draw attention to the spaces of interdisciplinarity, from the field to the lab and the meeting room, the role of researchers’ reflexivity and positionality, and the importance of being aware of the embodied, emotional realities of such work. In so doing, we call for more critical, evidence-based reflection upon the lived in/congruities of interdisciplinary practices.

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