Artigos - Matemática - FEIS

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Gingivitis in calves: longitudinal hematological and metabolic profiles-and salivary buffering capacity in animals treated with virginiamycin
(2023-01-01) Vaccari, Juliana [UNESP]; Ramos, Thamiris Naiasha Minari [UNESP]; Júnior, Elerson Gaetti-Jardim [UNESP]; Chaves-Neto, Antonio Hernandes [UNESP]; Borsanelli, Ana Carolina; Saraiva, Júlia Rebecca [UNESP]; de Souza, Natália Cristina [UNESP]; Bomfim, Suely Regina Mogami [UNESP]; Schweitzer, Christiane Marie [UNESP]; Dos Santos Dutra, Iveraldo [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de Goiás (UFG)
Gingivitis is an infectious inflammatory process that generates local and systemic conditions, compromising the masticatory capacity of animals. Virginiamycin controls and prevents gingivitis and necrotizing gingivitis in cattle. However, the interaction and effect with different sera and salivary elements remain unknown. The present 6-month longitudinal study evaluated the hematological, metabolic, and salivary buffering capacity profiles of calves with gingivitis treated with virginiamycin. Ten calves were divided into two groups: control and virginiamycin (n = 5 each). Calves in the virginiamycin group had a lower occurrence of gingivitis (P < 0.01, Student’s t-test). The animals that developed gingivitis in both experimental groups had higher salivary levels of alkaline phosphatase (P = 0.01915) and lower serum levels of albumin (P = 0.0028). Additionally, animals receiving virginiamycin had higher serum levels of magnesium (P = 0.008), albumin (P = 0.0008), urea (P = 0.008), alkaline phosphatase (P = 0.008), total proteins (P = 0.008), and plasma protein (P = 0.018). Salivary buffering capacity was negatively correlated with salivary variables such as calcium, magnesium, albumin, total protein, and aspartate aminotransferase and serum variables such as albumin and aspartate aminotransferase. Results of the present study suggested that the occurrence of periodontopathies in episodes is reflected in the local and systemic alterations in animals. In this context, clinical periodontal monitoring also showed the benefits of virginiamycin supplementation on gingival conditions and systemic health markers, in addition to controlling the two precursor forms of periodontitis.
Population evaluation of the adapted particle swarm optimization algorithm applied for control in view of unknown parameter changes in the system
(2023-02-01) Karmouche, Diogo Cunha José [UNESP]; Chavarette, Fábio Roberto [UNESP]; de Abreu, Gustavo Luiz Chagas Manhães [UNESP]; Gonçalves, Aparecido Carlos [UNESP]; Universidade Estadual Paulista (UNESP)
A proposed particle swarm optimization algorithm is analyzed to adapt the controller to an inverted pendulum system, where the physical parameters of the system will be changed throughout for iterations. The parameters to be changed will be the friction coefficients, the length of the pendulum rod, and the mass of the car at different times of the iterations. The five populations used to evaluate the performance of the algorithm in the adaptation of control vectors were generated in different ways using a random normal distribution, the linear–quadratic regulatory technique, and the description of the linear–quadratic regulatory technique in linear matrix inequality, thus occupying different regions of the search space and having different characteristics. The study shows that the proposed algorithm adapts the control vector independent of the origin of the populations and without knowledge of the changes in the system, thus demonstrating the contribution of this work.
Analysis of the Influence of Gasoline Adulteration on Lubricant Degradation and Internal Combustion Engine Performance
(2022-09-27) Gonçalves, Aparecido Carlos [UNESP]; Ferreira, Ronaldo Lourenço [UNESP]; Preto, Eduardo [UNESP]; Karmouche, Diogo [UNESP]; Chavarette, Fábio Roberto [UNESP]; Outa, Roberto [UNESP]; Universidade Estadual Paulista (UNESP); UniRV─University of Rio Verde
In internal combustion engines, studies of the effects of fuel adulteration focus on problems that occur in the fuel system and pollutants, but little attention is paid to lubricants. Some of these research studies are focused on detecting adulteration rather than the impact of this tampering on the internal combustion engine and lubricant degradation. This work evaluates, in addition to the problems in the supply system, the early degradation of the lubricant from the physical and chemical changes it undergoes when using adulterated gasoline in an internal combustion engine. For that, a 160cc Honda stationary engine mounted on a bench and connected to an alternator through a transmission belt was used. Fuels adulterated with ethanol, kerosene, and thinner were used in proportions of 5, 10, 15, and 20%. The cycles were 40 h each, which is equivalent to approximately 2000 km covered. To measure the engine time and rotation, a tachometer/hourmeter was used, where the time of each cycle was recorded. Particle quantifier analysis (PQA) tests and infrared spectrometry (sulfation, nitriding, oxidation, and total acid number (TBN)) were performed, in addition to changes in engine behavior in relation to rotation. The results showed changes in rotation according to the concentration and type of contaminants. Engine wear was small for the 2000 km covered. The sulfation, nitriding, oxidation, and TBN levels were altered, indicating the degradation of the lubricating oil.
Monitoring periodontal lesions and their effects during pregnancy: microbiological aspects of the oral cavity and amniotic fluid in pregnant ewes
(2023-01-01) Souza, Natália C. [UNESP]; Ramos, Thamiris N.M. [UNESP]; Borsanelli, Ana Carolina; Saraiva, Júlia R. [UNESP]; Ferreira, Evandro M.; Schweitzer, Christiane M. [UNESP]; Elerson, Gaetti-Jardim [UNESP]; Dutra, Iveraldo S. [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de Goiás (UFG); Universidade de São Paulo (USP)
Periodontitis affects the teeth supporting tissues, leading to tooth loss and damage to animal health. Evidence in humans suggests that oral microorganisms spread systemically, increasing the risk of pregnancy disorders such as miscarriage, prematurity, and low birth weight. This study aimed to verify whether periodontopathogenic microorganisms reach the transplacental unit, culminating in problems in pregnant ewes. After analyzing the oral cavity, 10 clinically healthy pregnant ewes (OGCH group) and 10 pregnant ewes with periodontitis (OGP group) were selected. The subgingival biofilm was collected for the polymerase chain reaction (PCR) test and amniotic fluid for both the PCR and interleukin (IL) analysis. Peripheral blood was collected for complete blood count, and analyses of IL-6, IL1-β, and tumor necrosis factor-α were performed. Placental fragments were collected to assess the inflammatory changes using optical microscopy. After giving birth, both the ewes and their lambs were weighed. On clinical examination, a positive correlation between bleeding and suppuration (correlation index – CI=0.54), suppuration and marginal gingivitis (CI=0.34), and marginal gingivitis and edema (CI=0.54) was observed. The weights of the ewes (p=0.013) and their respective lambs (p=0.04) in the OGP group were lower than those of their OGCH group counterparts. The hematological analysis revealed that the OGP group ewes showed a slight increase in the mean corpuscular volume (p=0.2447), segmented cells (p=0.3375), and eosinophils (p=0.3823) when compared with the OGCH group ewes, without a statistical difference. Regarding the microorganisms detected in the oral cavity, there was a significant difference between the occurrence of periodontal pockets and the presence of Fusobacterium necrophorum (p=0.0328), Porphyromonas asaccharolytica (p=0.0392), and the Mollicutes class (p=0.0352). Staphylococcus genus (p=0.9107) and Archaea domain (p=0.7245) were detected in the amniotic samples of both groups, without a significant difference, whereas P. asaccharolytica (p=0.2685) was only detected in one sample in the OGCH group. The expression of cytokine IL-6 in the OGP group differed significantly between the prepartum and postpartum periods (p=0.0039); moreover, it differed significantly in the postpartum period between the OGCH and OGP groups (p=0.0198). Histological examination showed a higher percentage of placental changes in the OGP group (70%) than in the OGCH group, such as the presence of macrophages, neutrophils, plasma cells, and multifocal areas of calcification. These results do not corroborate the hypothesis of dissemination of oral microorganisms to the placental unit, suggesting that it constitutes placental isolation in sheep.
In vitro germination of passion fruit seeds in the function of tegument removal and culture media
(2023-01-01) Faria, Glaucia A. [UNESP]; Lopes, Beatriz G.; Suares-Rocha, Paula [UNESP]; Ferreira, Antonio F. A.; Maltoni, Katia L. [UNESP]; Silvério Junior, Luiz H.; Pigari, Lucas B. [UNESP]; Felizardo, Lucas M. [UNESP]; Furlani Júnior, Enes [UNESP]; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP); Faculdade Centro Mato-grossense/Departamento de Agronomia
The presence of salts in the culture medium and the addition of phytohormones, necessary to break seed dormancy in the in vitro germination of passion fruit, can induce critical values of osmotic potential. This can change the membrane permeability of seeds, affecting the hydration rate, enzyme release, ion transport, pH, and inhibitor values, which may decrease germination percentage. The aim of this study was to evaluate different types of culture media, composed of other substances, combined with mechanical techniques of tegument removal to determine the most appropriate culture medium for the in vitro germination of Passiflora edulis (Sims flavicarpa Deg.) seeds obtained by open pollination. The experimental design was completely randomized in a 10 × 3 factorial scheme (10 culture media × three types of seed-intact, scarified, and cut), with eight replicates and five seeds per plot. Scarified seeds cultivated in a medium composed of a commercial substrate and gibberellic acid presented a higher percentage of germination than intact or cut seeds cultivated in different concentrations of Murashige & Skoog (MS) medium. Scarification is a satisfactory method for breaking the dormancy of passion fruit seeds, and commercial substrates Bioflora® enriched with gibberellic acid may replace in vitro germination.
Selection of desirable characters for papaya genetic improvement programs associated with hydric and thermal stress
(2023-01-01) Costa, Taís F. [UNESP]; Lopes, Beatriz G.; Faria, Glaucia A. [UNESP]; Ribeiro, Otavio A. P. da S. [UNESP]; Suares-Rocha, Paula [UNESP]; de Lima, Juliana F.; Felizardo, Lucas M. [UNESP]; Furlani Junior, Enes [UNESP]; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP); Universidade Federal do Recôncavo da Bahia
Papaya cultivation is widespread in Brazil, particularly in the states of Bahia and Espírito Santo, where most commercial plantations are concentrated. Owing to the economic and social importance of papaya, the present study aimed to determine the explanatory variables between the genotypes of two cultivars: Golden (from the Soil group) and Tainung Nº 1 hybrid (from the Formosa group), cultivated under high temperatures and hydric stress. The genotypes containing more desirable agronomic characteristics were identified for use in plant genetic improvement programs. Principal component analysis (PCA) was applied to select the desirable genotypes for Golden and Tainung Nº 1 cultivars based on specific variables analyzed for two groups of variables; for group 1, the plant height, stem diameter, leaf length, leaf width, and leaf number were analyzed, whereas for group 2, the leaf and root dry mass, stem dry mass and fresh mass of 10 discs, fresh mass, and stem and root fresh mass were analyzed. When exposed to hydric and thermal stress, the Tainung Nº 1 cultivar outperformed the Golden cultivar for the evaluation characteristics selected for use in genetic improvement programs.
A practical approach to evaluate periodic rods composed of cells with geometric and material periodicity
(2023-06-09) Santos, Rodrigo B.; Berres, Gabriel; Inman, Daniel J.; Gonsalez-Bueno, Camila G. [UNESP]; Bueno, Douglas D. [UNESP]; Faculty of Engineering; College of Engineering; Universidade Estadual Paulista (UNESP)
The use of a periodic structure is an useful alternative for suppressing vibrations without requiring strategies of active control. The main characteristic of this type of strategy is to conveniently define the geometry and material of the structure. Although there are different techniques for designing periodic structures, these methods typically require a candidate structure for computing the desired band gap. Thus, if a specific target frequency (or frequency range or band gap) is required, these methods need to be solved repetitively for different candidate structures, until the desired result is achieved. In this context, the present article introduces an approach for designing periodic rods considering both geometric and material periodicity. A new equation is derived from the state vector notation and the longitudinal transmitted wave is examined in computing the vibration transmissibility. The proposed equation allows one to define a target frequency, for which the band gap is specified, and its solution provides two parameters which are used to design the periodic rod. Alternatively, the proposed approach allows verification of the frequency of minimum transmissibility for a pre-defined candidate structure. Numerical simulations and experimental tests are presented to demonstrate the approach. The results show that the proposed approach is a useful strategy for designing periodic structures.
On the modeling of circular piezoelectric transducers for wave propagation-based structural health monitoring applications
(2023-01-01) Lopes, Kayc W [UNESP]; Gonsalez-Bueno, Camila G [UNESP]; Inman, Daniel J; Bueno, Douglas D [UNESP]; Universidade Estadual Paulista (UNESP); University of Michigan
Structural Health Monitoring (SHM) techniques have an important role in the performance of mechanical structures. In particular, piezoelectric transducers (PZT) have been employed for establishing damage detection processes in SHM systems. However, despite their wide use, there is limited information in the literature regarding important characteristics for SHM applications, such as the shape, dimensions and frequencies to use, which can affect the performance of the system used to detect the damage. This article investigates longitudinal and flexural waves for applications using circular piezoelectric transducers bonded to thin plates. The methodology allows one to obtain optimal frequencies to create and capture both types of waves and understand the influence of the geometric characteristics of these transducers on the damage detection. Numerical simulations are carried out to show that a change in the parameters of the piezoelectric transducers can maximize the waves amplitudes incoming at the sensor. Results from experimental tests are presented to demonstrate the proposed methodology. New equations are introduced and they compute output voltage and determine optimal frequencies to monitor the structure. The findings contribute to establishing a more efficient design of a damage detection process involving plate-like structures in SHM systems based on wave propagation.
Gingivitis in calves: longitudinal hematological and metabolic profiles- and salivary buffering capacity in animals treated with virginiamycin
(Univ Federal Santa Maria, 2023-01-01) Vaccari, Juliana [UNESP]; Ramos, Thamiris Naiasha Minari [UNESP]; Gaetti-Jardim Jr, Elerson [UNESP]; Chaves-Neto, Antonio Hernandes [UNESP]; Borsanelli, Ana Carolina; Saraiva, Julia Rebecca [UNESP]; Souza, Natalia Cristina de [UNESP]; Bomfim, Suely Regina Mogami [UNESP]; Schweitzer, Christiane Marie [UNESP]; Dutra, Iveraldo dos Santos [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Federal de Goiás (UFG)
Gingivitis is an infectious inflammatory process that generates local and systemic conditions, compromising the masticatory capacity of animals. Virginiamycin controls and prevents gingivitis and necrotizing gingivitis in cattle. However, the interaction and effect with different sera and salivary elements remain unknown. The present 6-month longitudinal study evaluated the hematological, metabolic, and salivary buffering capacity profiles of calves with gingivitis treated with virginiamycin. Ten calves were divided into two groups: control and virginiamycin (n = 5 each). Calves in the virginiamycin group had a lower occurrence of gingivitis (P < 0.01, Student's t-test). The animals that developed gingivitis in both experimental groups had higher salivary levels of alkaline phosphatase (P = 0.01915) and lower serum levels of albumin (P = 0.0028). Additionally, animals receiving virginiamycin had higher serum levels of magnesium (P = 0.008), albumin (P = 0.0008), urea (P = 0.008), alkaline phosphatase (P = 0.008), total proteins (P = 0.008), and plasma protein (P = 0.018). Salivary buffering capacity was negatively correlated with salivary variables such as calcium, magnesium, albumin, total protein, and aspartate aminotransferase and serum variables such as albumin and aspartate aminotransferase. Results of the present study suggested that the occurrence of periodontopathies in episodes is reflected in the local and systemic alterations in animals. In this context, clinical periodontal monitoring also showed the benefits of virginiamycin supplementation on gingival conditions and systemic health markers, in addition to controlling the two precursor forms of periodontitis.
Sugarcane Fields: Harvest Systems and Residue Management
(Crc Press-taylor & Francis Group, 2017-01-01) La Scala, Newton [UNESP]; Bordonal, Ricardo de Oliveira [UNESP]; Figueiredo, Eduardo Barretto de [UNESP]; Panosso, Alan Rodrigo [UNESP]; Moitinho, Mara Regina [UNESP]; Corradi, Mariana Marotti [UNESP]; Lal, R.; Universidade Estadual Paulista (UNESP)
Sugarcane (Saccharum officinarum) fields in Southern Brazil have been progressively converted from a burned harvest regime (BH) to a non-burned green mechanized harvest (GH), after which a large amount of crop residue is left on the soil surface. This conversion has resulted in ongoing social, economic, and environmental changes. In this entry, we analyze the aspects of soil physics and chemistry related to this conversion, with special emphasis on carbon dioxide (CO2) emissions and soil carbon (C) accumulation. We show how small changes in soil C stocks, related to increased soil CO2 emissions arising from different management options, can impact the C footprint of ethanol. Ethanol is an important option as a replacement for fossil fuels. The results we present and the mechanisms we discuss reveal an optimum land management strategy once the sugarcane areas are converted from a BH to a GH system, and the soil is left covered with sugarcane crop residue. Very different from a bare soil surface scenario, we predict that this is a more appropriate method for sustainable and long-term needs. Here, we maintain that when assessing the long-term effect of sugarcane-based ethanol production, consideration should be given to the long-term effects on the agroecosystem, particularly the soil being the basis for sustainability.
Design of Nearly-Orthogonal Symmetric Wavelet Filter Banks Based on the Wavelet Orthogonalization Process
(2022-01-01) Gossler, Fabrício Ely [UNESP]; Duarte, Marco Aparecido Queiroz; Villarreal, Francisco [UNESP]; Universidade Estadual Paulista (UNESP); Universidade Estadual de Mato Grosso do Sul (UEMS)
This work proposes a new method for nearly-orthogonal wavelet filter banks design based on the wavelet orthogonalization process. A new procedure to extract semi-conjugate filters from non-orthogonal wavelets is used for such purposes. The proposed methodology allows the design of symmetrical odd length nearly-orthogonal wavelet filters according to the frequency domain specifications. Finite impulse response wavelet filters with linear phase are obtained, not implying significant gain distortions and satisfying perfect reconstruction condition as accurately as possible. A signal decomposition example is presented and the wavelet coefficients results are compared with orthogonal and biorthogonal wavelet filter banks. Considering such an example, the best result was obtained by one of the proposed nearly-orthogonal wavelet filter banks. Some nearly-orthogonal wavelet filter banks designed in this work are applied in the context of image compression, involving the reconstruction process. Image compression results from a nearly-orthogonal wavelet filter designed in this work are superior to those from some classical wavelet filters.
LQR Optimal Control Applied in an Energy Harvesting System with Non-ideal Excitation Operating with Uncertain Parameters
(2022-01-01) de Almeida, Estevão Fuzaro [UNESP]; Chavarette, Fábio Roberto [UNESP]; Universidade Estadual Paulista (UNESP)
The majority of active control applications in vibrational dynamic systems are utilized to minimize vibrations. The goal of this research, on the other hand, is to employ vibrations to generate electrical energy in such a way that the vibration becomes a desired phenomenon. The change of the physical characteristics of the system was conducted in this work with the goal of enhancing the modeling of complex energy harvesting systems with non-ideal excitation, bringing higher resilience, and bringing them closer to reality. To stabilize the orbits and compare the power generated by the systems with and without control, the optimal control technique via Linear Quadratic Regulator (LQR) is used.
Dysbiosis and predicted function of dental and ruminal microbiome associated with bovine periodontitis
(2022-08-12) Borsanelli, Ana C.; Athayde, Flávia R. F. [UNESP]; Riggio, Marcello P.; Brandt, Bernd W.; Rocha, Fernando I.; Jesus, Ederson C.; Gaetti-Jardim, Elerson [UNESP]; Schweitzer, Christiane M. [UNESP]; Dutra, Iveraldo S. [UNESP]; Universidade Federal de Goiás (UFG); Universidade Estadual Paulista (UNESP); University of Glasgow; University of Amsterdam and VU University Amsterdam; Universidade Federal Rural do Rio de Janeiro; Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA)
Extensive cattle livestock is advancing in Amazonia and its low productivity, with consequent pressure to open new areas, is partly due to sanitary problems and, among them, the periodontal diseases, whose environmental triggers or modifying factors are unknown. In this study, we used high-throughput sequencing, network analysis and predicted functions to investigate the dental and ruminal microbiota of cattle raised in new livestock areas in the Amazon and identify possible keystone pathogens and proteins associated with the disease. Ninety-three genera were common in dental and ruminal fluid microbiomes and among them periodontal pathogens such as Fusobacterium, Prevotella, Porphyromonas and Actinomyces were recognized. Network analysis showed that dental microbiomes of clinically healthy animals tend to comprise a group of OTUs in homeostasis and when analyzed together, dental and ruminal fluid microbiomes of animals with periodontitis had almost twice the number of negative edges, indicating possible competition between bacteria and dysbiosis. The incisor dental and ruminal fluid microbiomes were dominated by a core community composed of members of the phyla Firmicutes and Bacteroidetes. Network results showed that members of the Prevotella genus stood out among the top five OTUs, with the largest number of hubs in the dental and ruminal microbiota of animals with periodontitis. Protein families linked to an inflammatory environment were predicted in the dental and ruminal microbiota of cattle with periodontitis. The dissimilarity between dental microbiomes, discriminating between healthy cattle and those with periodontitis and the identification of possible key pathogens, represent an important reference to elucidate the triggers involved in the etiopathogenesis of bovine periodontitis, and possibly in the development of measures to control the disease and reduce the pressures for deforestation.
A new approach to suppressing the Sommerfeld effect in vibrating structures
(2022-09-01) Brogin, João Angelo Ferres [UNESP]; Bueno, Douglas D. [UNESP]; Santos, Rodrigo Borges; Varanis, Marcus; Universidade Estadual Paulista (UNESP); Federal University of Grande Dourados (UFGD); Universidade Federal de Mato Grosso do Sul (UFMS)
The Sommerfeld effect is a non-linear phenomenon which occurs due to the interaction between non-ideal sources of energy and a mechanical system operating in the non-stationary regime. In certain conditions, this leads to high-amplitude vibrations that may be potentially harmful to the health of the structure. Although the Sommerfeld effect is relatively well studied, control strategies specifically designed for it still lack in the literature. Therefore, this work proposes a new approach to suppressing these undesired effects, based on fuzzy Takagi-Sugeno Modeling, in a three-degree-of-freedom shear building considering the equations of motion with and without a non-linear stiffness. The results show that the vibrations can be efficiently controlled and even chaotic patterns of motion are suppressed. Practical applications involving the controller for future work are also discussed in detail.
Chaotic and stochastic dynamics of epileptiform-like activities in sclerotic hippocampus resected from patients with pharmacoresistant epilepsy
(2022-04-01) Araújo, Noemi S.; Reyes-Garcia, Selvin Z.; Brogin, João A.F. [UNESP]; Bueno, Douglas D. [UNESP]; Cavalheiro, Esper A.; Scorza, Carla A.; Faber, Jean; Universidade de São Paulo (USP); Universidad Nacional Autónoma de Honduras; Universidade Estadual Paulista (UNESP)
The types of epileptiform activity occurring in the sclerotic hippocampus with highest incidence are interictal-like events (II) and periodic ictal spiking (PIS). These activities are classified according to their event rates, but it is still unclear if these rate differences are consequences of underlying physiological mechanisms. Identifying new and more specific information related to these two activities may bring insights to a better understanding about the epileptogenic process and new diagnosis. We applied Poincaré map analysis and Recurrence Quantification Analysis (RQA) onto 35 in vitro electrophysiological signals recorded from slices of 12 hippocampal tissues surgically resected from patients with pharmacoresistant temporal lobe epilepsy. These analyzes showed that the II activity is related to chaotic dynamics, whereas the PIS activity is related to deterministic periodic dynamics. Additionally, it indicates that their different rates are consequence of different endogenous dynamics. Finally, by using two computational models we were able to simulate the transition between II and PIS activities. The RQA was applied to different periods of these simulations to compare the recurrences between artificial and real signals, showing that different ranges of regularity-chaoticity can be directly associated with the generation of PIS and II activities.
Nonlinear Dynamics, Chaos and Control of the Hindmarsh-Rose Neuron Model
(2022-01-01) de Lima, Raildo Santos; Chavarette, Fábio Roberto [UNESP]; Universidade Federal de Mato Grosso do Sul (UFMS); Universidade Estadual Paulista (UNESP)
Mathematics has changed over time to comprise interdisciplinary fields of research, and consid- ering this, biomathematics has arisen as an interface study. In this work, we analyze the dynamical behavior of the Hindmarsh-Rose neuron model, which describes the neuronal bursting in a single neuron. A stability study through the Lyapunov exponents method is proposed and evidence of a chaotic dynamics is presented. This chaotic behavior is biologically comparable to an individual undergoing an epileptic seizure, in which the application of an efficient controller represents a proposal for preventing epilepsy from happening. Therefore, a control design based on the State-Dependent Riccati Equation is proposed aiming to reduce the oscillation of the system to a desired orbit. The results show that the controller is efficient and robust as a method for preventing epileptic seizures.
Analysis of the Influence of Contamination in Lubricant by Biodiesel in a Pin-On-Disk Equipment
(2022-01-01) Cuerva, Murilo Parra; Gonçalves, Aparecido Carlos [UNESP]; Da Consolação Fonseca de Albuquerque, Maria [UNESP]; Chavarette, Fábio Roberto [UNESP]; Outa, Roberto; De Almeida, Estevão Fusaro [UNESP]; Centro Universitário Votuporanga - UNIFEV; Universidade Estadual Paulista (UNESP); Faculdade de Tecnologia de Araçatuba - FATEC
The introduction of biodiesel to commercial diesel is being increased every year. The need to check this addition to the engine and lubricant is important for automakers and internal combustion engine manufacturers. The oil analysis technique is a type of predictive maintenance, done by collecting oil from equipment and analyzing it later in the laboratory, or by analyzing it directly and continuously in on-line systems. In internal combustion engines, all parts have a pre-established service life, longer or shorter, according to the specific function assigned to it. By analyzing the oil, the condition of these parts can be monitored. The oils analysis reveals the first signs of wear of a component. The identification is made based on the study of the number of particles, size, shape and composition thereof, present in the lubricant samples, which provide accurate information about the conditions of the moving surfaces without the need to disassemble the assembly to which these parts belongs. In this work a lubricant contamination by biodiesels were made to simulate possible scenarios within an internal combustion engine.The lubricant recommended by an engine manufacturer was contaminated with commercial diesel and with different percentages and types of biodiesel. After this contamination they were placed in a pin on disk device under certain conditions.Through the analyzes of the lubricants extracted from the Pin on disk Equipment after the tests, some analysis were carried out in order to study the effects of using biodiesel in the internal combustion engine.These analyzes consisted of Flash point, analytical ferrography, monitoring of ferrous particles generated, viscosity, viscosity index, basicity index and X-ray spectrometry.Among the results obtained it is observed that for a 5% contamination of animal biodiesel there was an increase in the viscosity index. Conversely, the contamination of 5% of animal + vegetable biodiesel decreased the viscosity index in relation to Diesel B5. We also found that these biodiesel additions were not detrimental to the engine and lubricant at the mix ratios and test conditions used.
Design, construction and evaluation of a device for the manufacture of ferrogram for analytical ferrography
(2022-03-01) Júnior, Anderson Inácio Junqueira; Gonçalves, Aparecido Carlos [UNESP]; Ribeiro, Victor Hugo [UNESP]; Chavarette, Fábio Roberto [UNESP]; Outa, Roberto; UniRV - Rio Verde University; Universidade Estadual Paulista (UNESP); Araçatuba Technology College – FATEC
The dynamism of the reliability of machines and equipment has the objective of availability, leading to the development of several techniques of predictive maintenance, to define the ideal point for the intervention. Among the several predictive techniques, the analysis of lubricants has its highlight. In this sense, lubricants are used to reduce friction and wear between two interacting surfaces, filling the space of surface imperfections. In this way, wear is common even with the use of lubricating oils on the interacting surfaces. Thus, an artefact for ascertaining the wear particles by size in lubricating oils is analytical ferrography. In this way, this work presents the development of a low cost rotary separator prototype to obtain ferrograms, through five distinct combinations of permanent magnets and electronic devices. Several combinations of magnets were used and it was concluded that the 03, 04, and 05 combinations showed a better formation quality of ferrous wear particle rings. In addition, only two rings were formed in the 04 combination, but this was the best combination by size separation.
Reliability analysis using experimental statistical methods and ais: Application in continuous flow tubes of gaseous medium
(2021-08-20) Outa, Roberto; Chavarette, Fábio Roberto [UNESP]; Gonçalves, Aparecido Carlos [UNESP]; da Silva, Sidney Leal; Mishra, Vishnu Narayan; Panosso, Alan Rodrigo [UNESP]; Mishra, Lakshmi Narayan; Fatec Fernando Amaral de Almeida Prado; Universidade Estadual Paulista (UNESP); Faculdade de Tecnologia Itaquera Miguel Reale; Indira Gandhi National Tribal University; Vellore Institute of Technology
The motivation for the development of this work arose from the observation of maintenance in pressure vessels, which are categorized as highly hazardous security risk products. The costs of detecting failures in the production systems allow the result of the process to be safe and of good quality, using standardized tests internally within the company. The main objective of this work demonstrates the efficiency and robustness of the artificial immune system (AIS) of negative selection in the detection of failures by recognizing the vibration signals and categorizing them in the degree of probability and level of severity of failures. The intrinsic objectives are the application of the elimination of signal noise by the Wiener filter, and the processing of data-Wiener data using experimental statistics. The result of this work successfully demonstrates the precision between the experimental statistical and AIS techniques of negative selection; the robustness of the algorithm in precision and signal recognition; and the classification of the degree of severity and probability of failure.
Robust static output feedback H control for uncertain Takagi-Sugeno fuzzy systems
(2022-01-01) Elias, Leandro Jose; Faria, Flavio Andrade; Araujo, R.; Magossi, Rafael; Oliveira, Vilma Alves; Universidade Estadual Paulista (UNESP); Universidade de São Paulo (USP)
In this work, a robust static output feedback (SOF) design for continuous-time nonlinear systems under norm bounded uncertainties, described as a Takagi-Sugeno (TS) system is proposed. The key features are that a switching control law is used to activate the SOF gains to stabilize the uncertain TS fuzzy system and that the SOF design does not require the measurements of all premise variables in real time as in the standard fuzzy parallel distributed compensation (PDC) design. The main result is given in terms of linear matrix inequalities (LMIs) which guarantees a H attenuation level of for the SOF control system. The efficiency of the main results is illustrated with examples, including a nonlinear active suspension system under uncertain driver masses, and compared to other published results from the literature.

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