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Importância da mastofauna como ferramenta para conservação: estudo de caso do remanescente de Cerrado na UFSCar – campus São Carlos, SP
(Universidade Federal de São Carlos, 2023-02-01) Silva, Melissa Freitas da; Fieker, Carolline Zatta; https://lattes.cnpq.br/4453761595730340; Carmignotto, Ana Paula; https://lattes.cnpq.br/0633095503285315; https://lattes.cnpq.br/1303611652109341
Recently, discussions about the future of environmental conservation have received greater attention. Still, it is shocking to observe that, even though the increase of information currently available, biodiversity continues to suffer frequent anxieties. The Cerrado is considered one of the most impacted domains due to habitat loss and fragmentation, and the concern with the effects of human disturbances on biological communities is even more urgent for medium and large mammals, which need larger areas for their survival. Observing the movement and behavior of species in situ and comparing these data to the history of land use in the region, we can provide a consistent basis for planning future management actions that aim at the effective conservation of native vegetation remnants. The objective of this work was to inventory mammalian fauna found in the Cerrado remnant located at the UFSCar, Campus São Carlos, to discuss the use of this taxonomic group as a tool for conservation of this area, and to carry out scientific dissemination of the results here found. The use of camera traps and linear transects were chosen as the main survey methodology, in addition to the comparison with previous data available from literature for the studied and adjacent regions. Nine camera traps were evenly distributed in three phytophysiognomies: three in the “cerrado sensu stricto”, three in the “mata de galeria”, and three at an Eucalipto plantation. In this study, 30 species of medium and large mammals were recorded, including species poorly known or at some threaten category such as: Myrmecophaga tridactyla, Sylvilagus minensis Chrysocyon brachyurus, Herpailurus yagouaroundi, Leopardus pardalis, Puma concolor, Mazama rufa and Dicotyles tajacu. M. tridactyla, Cabassous sp., Dasypus septemcinctus, P. concolor and L. pardalis, are new records for the area. Domestic animals and exotic invaders were also recorded, like “java-porcos”, highlighting the need to preserve the native species. The great diversity of mammals sampled in this work is the proof of the resilience of the Cerrado, in the sense that it can maintain viable populations of native species in the region, and serves as support for future projects to obtain higher legislative protection for this area and other native Cerrado vegetation remnants. A guidebook was developed for scientific dissemination of the data here obtained, and is available for public use.
Fracionamento de lignina proveniente do processo kraft para obtenção de frações com diferentes massas molares e aplicação em materiais funcionais: espumas de carbono.
(Universidade Federal de São Carlos, 2023-02-01) Rodrigues, Jéssica de Souza; Botaro, Vagner Roberto; https://lattes.cnpq.br/2907189124654066; https://lattes.cnpq.br/4368023496052703
This thesis has three main objectives: (i) To describe an efficient fractionation method for Kraft lignin (KL) to extract large amounts of low molecular weight lignin, which indicates the presence of a higher content of phenolic hydroxyl groups; (ii) Select KL fractions as a partial substitute for phenol in the synthesis of phenolic resins and correlate their structure-property; (iii) To describe an efficient route for the synthesis of carbon foams (CF) derived from KL fractions by thermal decomposition of a polyurethane (PU) sacrificial mold. The KL from Eucalyptus urograndis wood was refined by the ethyl acetate (EtOAc) fractionation process. The lignin-phenol-formaldehyde (LPF) resins were formulated replacing 25 and 50% of the phenol by fractionated lignin. The lignin used were KL, fraction of KL insoluble in EtOAc (LFIns) and fraction of KL soluble in EtOAc (LFSol). LFSol and LFIns fractions were analyzed for composition, functional group content and thermal properties. The structure-property correlation of the CF produced by the partial replacement of phenol by KL, and its fractions (LFSol and LFIns) was also analyzed. For this, the CF produced were characterized by thermal analysis, X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), Brunauer-Emmett-Teller (BET) and electrochemical measurements. Gel Permeation Chromatography (GPC) results indicated that lower molecular weight lignin fractions (LFSol) showed greater solubility in EtOAc. The total hydroxyl group content (by 31P NMR) of the LFSol fraction increased to 4.73 mmol.g-1 after fractionation. The phenolic resin based on LFSol-derived monomers showed adhesion resistance, glass transition temperature and thermal stability with values close to commercial phenolic resins. The better homogeneity of the LPF resin produced from LFSol, with 25% phenol replacement, resulted in adhesion properties similar to the control resin (2.58±0.13 and 2.38±0.23 MPa for the samples control and LFSol, respectively). On the other hand, FLSol can directly replace 15% of the commercial FF resin (corresponding to >30% phenol replacement) showing similar adhesive performance (4.71±0.22 and 4.56±0.43 MPa for the control and LFSol samples, respectively) compared to the commercial control and significantly superior to LFIns (3.38±0.20 MPa) and KL (3.59±0.23 MPa). The results indicated that the foam synthesized with LFSol had very similar properties to the control resin with 100% phenol. The potential of LFSol for application as an electrochemical sensor was also demonstrated, with good selectivity for the detection of hydroquinone in water.
Estudo da leitura do sinal de runout utilizando sensores do tipo eddy current em eixos de aço revestidos pelo processo de laser cladding
(Universidade Federal de São Carlos, 2023-02-01) Júnior, Fábio Tommasini de Carvalho; Paziani, Fabricio Tadeu; https://lattes.cnpq.br/2204448761802712; Franco, Vitor Ramos; https://lattes.cnpq.br/4590258470207467; https://lattes.cnpq.br/3231404823024264
The continuous vibration monitoring in rotary machines is a common practice at the automation engineering and predictive maintenance fields. Specially for gearboxes speed increasers and reducers, the radial and axial vibration of the rotary shafts is measured by vibration system analysis sets that use eddy current (EC) sensors for data collecting of relative displacement. When using proximity sensors, the surface conditions of the measured part directly influence the collected signal. In order to increase the reliability of the measurement, geometrical deviations in the runout track must be known. Therefore, the runout test is a crucial step in rotary sets manufacturing processes to ensure the integrity of these regions. The output results with EC sensors test is the Total Indicated Runout (TIR), which is a composition of geometric deviations of the surface (mechanical runout) and a noise in the collected signal known as electrical runout (ERO) that arises due to oscillations in the electrical and metallurgical properties of the target material, and this disturbances in signal are captured as variations in the distance betwen sensor and object. This test is widely practiced in industry for shafts manufactured from forged steel parts. Due to most diverse manufacturing deviations of these shafts, there are situations in which it is possible to carry out a process of adding material for dimensional recovery by addictive manufacturing (AM). One option is the material deposition technology through laser cladding process (LC). However, not much is known about how material properties of these coated layers applied over shafts influence the reading of EC sensors. This work explores the readings captured by an EC sensor during TIR tests on two rotating shafts made of steel alloys 18CrNiMo7-6 and 42CrMo4, each one of them coated with two metallic powder alloys - HGMET and X-402 - deposited by LC process. Considering the defects of the clads inherent to the coating process and the alterations caused in the microstructure of the substrate, it was concluded under the pre-established conditions and through the presented results that the ERO signal behaves randomly and presents values from 150 up to 400% above the values recorded on the uncoated substrate material. In practical terms for the industry, also considering the costs of the process for recovering shaft collars, the study does not recommend the use of this solution neither over vibration reading tracks nor their surroundings.
A ordem: tempo analítico, homicídios e PCC no Triângulo Mineiro (1990-2020)
(Universidade Federal de São Carlos, 2023-02-01) Marques, Thalia; Feltran, Gabriel de Santis; https://lattes.cnpq.br/6789864439048444; https://lattes.cnpq.br/0026361290425859
Homicide rates have varied widely in Brazil, in time and space, over the past four decades (1990-2020). From the standpoint of their aggregate levels, these rates rise consistently until 2017 and then fall. Detained observations in individual states and regions, however, show rapid upward and downward variations on the same dates. This dissertation proposes an interpretation of this phenomenon. Studying the Triângulo Mineiro, I propose the idea of "analytical time" of factional expansion, the time of passage from one order of regulation of lethal violence to another, to understand these variations. To accomplish this, I present a multi-methodological study, because it deals with a complex, relational, and multi-causal phenomenon, as are homicides. It is quantitative concerning the compilation, production, and analysis of homicide rates, and qualitative in understanding the mechanisms involved in homicide cases, in three cities of the region: Uberlândia, Uberaba, and Cidade da Saúde. This methodological and analytical framework could, as hypothesized here, be used to think about homicide variations in a relational way, in the national context.
Agrupamento em conjunto de dados com múltiplos atributos via redução de dimensionalidade e detecção de comunidades
(Universidade Federal de São Carlos, 2023-02-01) Modesto, Júlia Almeida; Valejo, Alan Demétrius Baria; https://lattes.cnpq.br/9546164790189830
This work falls within the field of Machine Learning and focuses on the challenge of Clustering in datasets with multiple variables. Addressing the issue of the Curse of Dimensionality, a common difficulty in high-dimensional data, the study focuses on Dimensionality Reduction and Community Detection techniques. The Curse of Dimensionality refers to the deterioration of the performance of certain learning algorithms as the dimensionality of the data increases. Few studies address the implications of graph-based clustering in this scenario, highlighting the need to investigate how clustering techniques can be adapted to effectively deal with high-dimensional datasets. Through the application of Community Detection Algorithms in conjunction with Graph Construction, the study aims to explore efficient methods for handling large volumes of data. The experiments conducted showed that, in datasets with a large number of samples, the use of Dimensionality Reduction techniques, in particular, resulted in superior performance in identifying significant clusters. This result emphasizes the importance of Dimensionality Reduction as a crucial tool for overcoming the challenges posed by the Curse of Dimensionality in Machine Learning environments. This work can assist future investigations and practical applications in complex and multidimensional data analysis.
Investigação sobre o potencial da instrumentação de baixo custo na digitalização de máquinas-ferramenta antigas e seu impacto na rugosidade superficial
(Universidade Federal de São Carlos, 2023-02-01) Durigan, Paulo de Tarso; Barbosa, Gustavo Franco; https://lattes.cnpq.br/4027686840017498; Shiki, Sidney Bruce; https://lattes.cnpq.br/0573973677787523; https://lattes.cnpq.br/3840295185099951
Intelligent manufacturing involves the convergence of Industry 4.0 technologies dedicated to modernizing production systems, which require active and real-time management to maximize their processes. In this sense, the integration of new technologies for monitoring manufacturing processes is becoming increasingly urgent to ensure competitiveness. However, many companies have outdated structures in which old and outdated machine tools that do not offer communication or data transmission represent a significant portion of the equipment in operation. The main reasons for this reality are the lack of financial resources for updating the manufacturing park and the lack of strategic vision for the business. Within this context, this study proposes an investigation into the impact of digitizing legacy machine tools on productivity and the potential for improving surface quality through low-cost instrumentation. For the development of this work, low-cost sensors and hardware were installed on a universal lathe for continuous and real-time monitoring of the turning process. Instrumentation based on the IoT (Internet of Things) concept allowed for data collection and exchange with a cloud-based analysis system via a Wi-Fi connection. A rapid prototyping board was used to collect sensor data and transmit it to the cloud platform, allowing for the creation of a history and real-time monitoring of the process. The results confirm the influence of cutting speed and feed rate on surface finish, as described in the literature. The instrumentation used showed good results in monitoring rotation and feed rate. The difference between the rotations (measured by the sensor and the configuration) was less than 4.38%, while the differences in feed rate did not exceed 6.33%. The results of vibration parameters were not as evident due to the low amplitudes presented in the analyzed spectrum. The main reason is associated with the low sensitivity of the accelerometer associated with the use of new cutting edges in each experiment, which reduces the vibration levels of the process. Despite the low amplitudes, it was possible to establish the influence of the RMS values on surface roughness. It is expected that this study will contribute to recent research on manufacturing process monitoring and enable a solid analysis of the benefits of real-time monitoring of machining on universal mechanical lathes.