Navegando por Orientadores "ESTUMANO, Diego Cardoso"

Agora exibindo 1 - 7 de 7

Acesso aberto (Open Access)
Aplicação do método Lean no processo de cadeia de manutenção
(Universidade Federal do Pará, 2020-11-25) CAVALCANTE, Milca Daniele Marques; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
With the fourth industrial revolution underway and a globalized market, organizations must be agile and flexible to meet customer requirements and needs. As a result, organizations should use management tools and techniques that add value to their products and/or services, that is, that allows them to produce more with fewer resources. In this perspective, this work aims to develop an analysis of the application of Lean Manufacturing tools in the management of Maintenance Planning and Control (PCM) of a mining company. The study was based on a diagnosis of the initial situation of the PCM, in which low adherence to some indicators was identified, as well as the lack of a problem-solving method. Based on this, a methodology was developed to evaluate the indicators after the implementation of the shop floor and routine management tools (FMDS, kaizen and Andon), and also developed a flowchart to facilitate the employees' decision making regarding the type of continuous improvement tool to use to develop projects. within the PCM. With the implementation of the FMDS tools, Andon and kaizen were achieved consistent results that are presented in graphs, these results were achieved after using the Lean Manufacturing philosophy.
Acesso aberto (Open Access)
Estimativa de parâmetros aplicados em modelos epidemiológicos
(Universidade Federal do Pará, 2022-01-28) PINTO, Thiago Moreira; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153
In this study, the Bayesian Monte Carlo technique via Markov Chain (MCMC) was selected to estimate the parameters of the differential equations of the SQUIDER3 and SEIR4 compartmental models, seeking to reflect the propagation of Covid-19 in the state of Pará. An algorithm was developed in Matlab, reproducing the MCMC technique that uses stochastic processes and simulates a random selection of values of each parameter. When sampling proportionally to the probability of the values, a probability distribution was reached in order to be able to both adjust the model parameters and converge to the stationary distribution of interest. The parameters estimated in this paper for the SQUIDER and SEIR compartmental models were compared to real data using the Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC) metrics. Both of these were applied for a better definition of the model that best represents the Covid-19 propagation phenomenon in the state of Pará. As a result, histograms were obtained that indicate a convergence of parameters in the SQUIDER model, which did not happen in the SEIR model. By applying the AIC and BIC, it was demonstrated that the SQUIDER model was the best model to represent the phenomena (i.e. the propagation of Covid-19 in the state of Pará), and has the potential to be used as a predictive model.
Acesso aberto (Open Access)
Implantação do sistema milk run em uma empresa do polo de duas rodas em Manaus
(Universidade Federal do Pará, 2022-03-25) NOGUEIRA, Shelle Pontes; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153
Considering the current situation of the global economic crisis and globalized competition, it is necessary to reduce cost and improve productivity in industrial activities. In this context, logistics in general stands out as a source of opportunity for organizations to establish competitive advantages. In this respect, the present work seeks to highlight the contributions that the Milk Run System can bring to the improvement of the flow of materials in the supply area and with the work in partnership with its suppliers, allowing cost reduction through changes in logistics operations. The work was developed in a multinational company manufacturer of electronic parts for the 2 and 4 wheel poles, located in thecity of Manaus. The study showed that by replacing the conventional system with the Milk Run system, the company is able to improve delivery rates. In the case study, the work was carried out in the four suppliers with the highest volume of cargo, in which it was creating routes and delivery times that best met the interests of the company and suppliers.
Acesso aberto (Open Access)
Inserção da temperatura no modelo de Langmuir aplicado na adsorção de íons cobre por zeólita 5A : experimental e estatística Bayesiana
(Universidade Federal do Pará, 2025-02-05) SOUSA, Ana Paula Souza de; RODRIGUES, Emerson Cardoso; http://lattes.cnpq.br/7459428211048580; HTTPS://ORCID.ORG/0000-0002-0303-4578; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of wastewater contaminated by heavy metals represents a significant environmental challenge, with adsorption being one of the main approaches for removing these contaminants, as it exhibits high efficiency in molecular separation. Understanding the interaction between adsorbent and adsorbate is essential for predicting dynamics under different operational conditions. Thus, the use of modeling techniques in isotherm prediction allows for estimating adsorption performance, reducing the need for intensive experimentation, while promoting process optimization. Considering these factors, this work aimed to develop a predictive model capable of estimating adsorption isotherms of copper ions by zeolite 5A at different temperatures. The methodology involved the production and characterization of kaolin waste, metakaolin, and the zeolitic product, utilizing characterization techniques such as X-ray Fluorescence Spectrometry (XRF), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and thermal analyses, including Thermogravimetry (TG), Differential Thermogravimetry (DTG), and Differential Scanning Calorimetry (DSC), to determine the chemical and mineralogical composition, morphology, and thermal stability of the material. Adsorption isotherms of copper ions were performed at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC. To study the adsorption mechanisms and the adsorbent/adsorbate interaction, the Markov Chain Monte Carlo (MCMC) method with the Metropolis-Hastings algorithm was used to estimate model parameters and subsequently fit them to the experimental data. Based on these data, the Langmuir model was adapted to incorporate temperature, in the range of 25 ºC to 150 ºC, followed by the calibration, validation, and prediction of adsorption dynamics. The characterization results confirmed the potential use of kaolinitic waste for zeolite synthesis, as well as the successful formation of zeolite 5A through its chemical composition, mineralogy, and morphology. The isotherms revealed that copper removal capacity increased proportionally with temperature, obtaining a maximum adsorption capacity of 754.85 mg/g at 95 ºC. The parameter estimation validated the adaptation of the Langmuir model for different thermal conditions, which proved effective in predicting the isotherms, optimizing the adsorption process at different temperatures, and providing a good model estimate, thus enabling the reduction of extensive experimental activities.
Acesso aberto (Open Access)
Modelagem, simulação e estimação dos parâmetros por MCMC de um modelo que descreve a dinâmica de adsorção em uma coluna de leito fixo
(Universidade Federal do Pará, 2023-01-18) SOEIRO, Wilhamis Fonseca; VIEGAS, Bruno Marques; http://lattes.cnpq.br/1196600058247902; HTTPS://ORCID.ORG/0000-0002-2768-652X; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The treatment of industrial effluents is extremely important for both the environment and human health. The purification of water from polluting components, such as metals and organic compounds, for reuse in the industrial process can be considered one of the main applications in this field. Therefore, there is interest in modeling one of the most used treatment processes, adsorption. Aiming to describe the dynamics of the process in an adsorption column, in this work the method of lines and the pdepe function (matlab) are used to solve the model formed by the mass balance in the liquid phase, linear driving force equation (LDF) and the Langmuir isotherm for equilibrium. An evaluation of the model varying some experiment conditions was carried out, from which results congruent with those found in the literature were observed. In addition, a sensitivity analysis of the phenomenon was carried out in relation to the parameters: Langmuir constant, intraparticle mass transfer coefficient and axial dispersion coefficient. Subsequently, these parameters were estimated using the Monte Carlo technique via Markov chain (MCMC) using experimental data found in the literature. Finally, in general, the estimates were good enough to represent the adsorption dynamics of the evaluated experiments.
Acesso aberto (Open Access)
Modelos de estimativa de radiação solar global e análise Estatística em dez cidades do Estado do Pará – Brasil
(Universidade Federal do Pará, 2022-01-28) VALENTE, Alexandre Miguel da Cruz; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153
Estimating solar radiation is important for various segments of society such as agriculture, meteorology and electricity generation (photovoltaic systems). This workaims to estimate the Global Solar Radiation in ten cities in the state of Pará - Brazil, using estimation models, Hargreaves-Samani and Bristow-Campbell, using meteorological data provided by Automatic Meteorological Stations, belonging to the National Institute of Meteorology (INMET), to compare the observed and estimated values and analyze which model best fits the region, through the parameters Coefficient of Determination (R²), Willmott Index (d), Pearson correlation coefficient (r) andRelative Root Mean Squared Error (rRMSE). The results showed that the models are satisfactory and can be used to estimate the Global Solar Radiation, however for the less rainy period there was an overestimation, between june and november. The Castanhal station had the lowest average global solar radiation compared to the other stations with an average daily radiation equal to 15.06 M/m².day, while the city of Redenção had the highest daily average, 18.33 MJ /m².day. The city of Tomé Açu presented better fit of the models referring to the observed values, since for the HS model, the confidence index was considered very good, c equal to 0.78, and the relative RMSE was considered excellent, with rRMSE equal to 9.93%. For the B-C model for this station, the confidence index and the relative RMSE were considered good, c equal to 0.71 and rRMSE equal to 19.14%.
Acesso aberto (Open Access)
Produção de material zeolítico em escala semi piloto com o calor proveniente da dissolução de hidróxido de sódio
(Universidade Federal do Pará, 2025-02-05) LIMA, Haianny Beatriz Saraiva; COSTA, Deibson Silva da; http://lattes.cnpq.br/1521124351431087; HTTPS://ORCID.ORG/0000-0002-2165-2628; ESTUMANO, Diego Cardoso; http://lattes.cnpq.br/5521162828533153; https://orcid.org/0000-0003-4318-4455
The increasing demand for zeolitic materials, due to their high adsorption capacity, selectivity, and ion exchange, highlights the need for more efficient and sustainable production methods. Thus, the study aimed to produce zeolites on a semi pilot scale from kaolin waste, utilizing reactive heat for hydrothermal synthesis and applying these zeolites for copper ion adsorption. The methodology involved drying, disaggregation, and calcination of the kaolinitic waste, followed by the synthesis of the zeolitic material. Characterization of the materials was performed using X-ray Diffraction (XRD), X-ray Fluorescence (XRF), Scanning Electron Microscopy (SEM), and Thermogravimetric Analysis (TGA), Differential Thermogravimetric Analysis (DTG), and Differential Scanning Calorimetry (DSC). Subsequently, equilibrium isotherms were conducted at temperatures of 25 ºC, 35 ºC, 45 ºC, 55 ºC, 65 ºC, 75 ºC, 85 ºC, and 95 ºC, along with parameter estimation to study the adsorption mechanisms and the adsorbate/adsorbent interface. Additionally, modeling of the adsorption process for hydrogen sulfide (H2S) and carbon dioxide (CO2) gases was carried out, using experimental data from the literature and employing analytical breakthrough curve models to describe the adsorption phenomenon in continuous flow. The results confirmed the predominant presence of kaolinite in the waste, the efficiency of the calcination process, and the formation of zeolitic material, evidenced by the mineralogical and chemical composition, as well as the cubic morphology characteristic of zeolite 4A and the spherical shapes of sodalite. Thermal analyses elucidated changes associated with water loss and phase transitions. Adsorption tests demonstrated that the produced material was effective in removing copper ions, with a maximum amount adsorbed of 782,76 mg/g at 95 ºC, indicating a good interaction between the adsorbent and the adsorbate. Furthermore, the use of Bayesian techniques for parameter estimation in isotherm and breakthrough curve models enabled a better understanding of the process dynamics. Finally, this study demonstrated the feasibility of producing zeolites from kaolin residue on a semi-pilot scale using reactional heat, offering an approach that is less harmful to the environment and reduces costs through the reuse of industrial waste and energy optimization of the process.