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Uso da técnica laser-induced breakdown spectroscopy (LIBS) para análise direta de ligas metálicas: estratégias de normalização, calibração univariada e multivariada e modelos de classificação
(Universidade Federal de São Carlos, 2017-02-10) Castro, Jeyne Pricylla de; Pereira Filho, Edenir Rodrigues; https://lattes.cnpq.br/3394181280355442; https://lattes.cnpq.br/6327313723314696
This academic master's dissertation was devoted to the development of analytical methods for the determination of Al, Cr, Cu, Fe, Mn, Mo, Ni, Ti, V and Zn in alloys and steels. The main purpose of the study was to present the Laser-induced Breakdown Spectroscopy (LIBS) as a viable alternative for the direct analysis of alloys and steels using chemometric tools to interpret the obtained data. Initially, the optimization of the parameters of the LIBS equipment was done using Doehlert design, varying the laser energy in 7 levels (30 to 80 mJ), delay time in 5 levels (0 to 2 μs) and spot size in 3 levels (50 to 150 μm). The chosen compromise condition was 60 mJ of energy, 0.9 μs of delay time and 100 μm of spot size, which were applied to 80 samples. The reference values of the analytes were obtained using the X-ray Fluorescence (XRF) technique for the construction of calibration models.To minimize signal variations and sample matrix differences, twelve normalization modes were tested and two calibration strategies were studied: multivariate calibration using Partial Least Squares (PLS) and univariate calibration using area and height of several emission lines. Thus, we search to identify the best mode of normalization, emission line and calibration strategy for each analyte. For most analytes, there was no significant difference between the normalization modes and also between the univariate and multivariate calibration. Classification models were applied to identify the samples in 3 different groups. K-nearest neighbor (KNN), Soft independent modeling of class analogy (SIMCA) and Partial-least squares-discriminant analysis PLS-DA were used in 3 different matrices: concentrations obtained using XRF, height and area of the LIBS emission lines (total of 57 emission lines). When comparing the models, some merit figures were evaluated, such as accuracy, sensitivity, false alarm rate and specificity. The classification model that obtained the best results was KNN. As a conclusion of the work, factorial design was useful to obtain an adequate analysis condition for all analytes and samples simultaneously, saving time and resources. Normalization modes were effective to minimize signal variations and differences in sample matrices. Univariate models were more satisfactory than multivariate models. In the case of classification models, it was possible to identify the samples, being the KNN model more efficient than the others.
As práticas de intervenção precoce no estado de São Paulo
(Universidade Federal de São Carlos, 2017-02-10) Marini, Bruna Pereira Ricci; Della Barba, Patrícia Carla de Souza; https://lattes.cnpq.br/6448489426438006; https://lattes.cnpq.br/2001819857612181
Early Intervention is constituted as an important tool for prevention, identification and intervention in conditions that offer risks to child development. Since the emergence of the first programs dating back to the 1960s, there were a number of conceptual and theoretical developments which culminated in the recognition of the systemic, ecological and family-centered model, as it produces better effects. In Brazil, the Early Intervention practices appear to develop highly focused on the needs of children, prioritizing interventions guided in their problems and developed from a rehabilitative model. It also observes that, despite the relevance of the theme, the scientific literature is scarce, which points to the need for further investigation. In this context, this study aimed to identify the practices developed by the Early Intervention services for children from zero to five years, in the state of São Paulo. This is a cross-sectional, descriptive and exploratory study with a qualitative approach. Participants were selected through non-probability sampling for convenience, in the case of professional staff working in services for children between zero and five years, located in the area covered by the Programa São Paulo pela Primeiríssima Infância. The study was developed in two stages, the first identification and characterization of early intervention services and the second identification of early intervention practices developed for services previously selected from the first stage. Data were collected through questionnaires (first stage) and interview (second stage). For the analysis of data from the questionnaires was used the methodology of descriptive statistics and analysis of the interviews content analysis methodology, the thematic analysis mode. The results of this study corroborate with the descriptions in the national scientific literature showing that Early Intervention practices remain being developed within the rehabilitation model, geared to the deficits presented by the children. In this context, the participation of families in the services proved to be limited because of the hegemonic role played by professionals in relation to the intervention process. It also revealed the existence of differences between the recommended practices in the child care networks and those that, in fact, are developed by the services. Regarding the existence of practices implemented in the natural context of the child, the results showed that these have been limited to observations and guidelines. Finally, the study identified a number of gaps in the process of training and continuing education of professionals that working in Early Intervention, a factor that can directly impact on the quality and the implemented practice model. From these results, the possibilities and challenges for the approximation between current practices and those recommended internationally are discussed, based on IP literature and national child care policies.
Refusão superficial a laser da liga com memória de forma Cu-11,8Al-3,2Ni-3Mn (% Peso)
(Universidade Federal de São Carlos, 2017-02-10) Silva, Murillo Romero da; Gargarella, Piter; https://lattes.cnpq.br/4641435644243916; Bolfarini, Claudemiro; https://lattes.cnpq.br/9231627080617037; https://lattes.cnpq.br/7741315791368505
Shape memory alloys (SMA) are alloys that undergo martensitic transformation due to an external solicitation (temperature, stress, strain or magnetic field) and are capable of recovering permanent deformation when heated above a critical temperature. The most used shape memory alloys are Ti-Ni- and Cu-based. Cu-based SMA have some advantages due to better thermal and electrical conductivity, lower production cost and are easier to process. The main disadvantage of Cu-based SMA is its low ductility. This property is improved by decreasing the grain size and by a reduction of microstructural heterogeneities. This can be achieved at the surface of structural components after LASER remelting, through which the surface of the material is remelted by a LASER beam and solidifies under extremely high cooling rates. In this context, the aim of the present work is to investigate the influence of LASER surface remelting in the microstructure, thermal stability and mechanical properties of Cu-11.8Al-3.2Ni-3Mn (wt. %) SMA plates obtained by suction casting. The samples were characterized by optical and scanning electron microscopy, energy dispersive X-ray spectroscopy, electron backscatter diffraction, X-ray computed tomography, X-ray diffraction, differential scanning calorimetry as well as by tensile and microhardness tests. The results show that small shifts in the transformation temperatures occur due to the LASER treatment. It was observed that only the monoclinic β’1 martensitic phase formed in the as cast and LASER treated samples. The LASER treatment provided an improvement in mechanical properties with an increase of up to 162 MPa in fracture stress, up to 2.2% in fracture strain and up to 21 HV in microhardness when compared with the as-cast sample. This makes the surface remelting treatment a promising method for improving the mechanical properties of Cu-based SMA.
Eefeitos de posicionamentos em “tilt” e “recline” na distribuição da pressão no assento de pessoas com tetraplegia
(Universidade Federal de São Carlos, 2017-02-10) Gradim, Luma Carolina Câmara; Cruz, Daniel Marinho Cezar da; https://lattes.cnpq.br/7350460642976728; https://lattes.cnpq.br/6753297003669861
The development of pressure ulcers (PU) in people with spinal cord injury (SCI) is a relevant factor and directly affects the health. Several preventive methods in a wheelchair have been researched for pressure relief, health promotion and disease prevention, such as PU. Some methods such as seating positioning system, different cushions and variable positions as tilt and recline seating systems, are most commonly used to relieve the pressure, and have been studied and achieved significant results for people with SCI in wheelchair. This study aims, thus, to evaluate the pressure redistribution buttock interface / cushion in areas susceptible to UP (sacrum, ischia) for the positions of tilt and recline in the wheelchair, in people with tetraplegia by spinal cord injury. In order to proceed to the research, we analyzed five people of both sexes with tetraplegia by LM, between 18 and 60 years. Was used a characterization form, a wheelchair simulator, ROHO ®High Profile Quadtro Select ™ cushion, a pressure mapping system, adaptations to the simulator and a questionnaire of satisfaction with the use of tilt and recline systems. As results, the pressure relief in the buttocks was better in higher angles, such as 10 ° tilt with 120 ° of recline, 20 ° tilt with 120 ° of recline and 30° tilt with 120° recline. But, even the smaller angulation positions resulted in pressure relief. Therefore, our results indicate that a greater angle of tilt and recline is needed to improve pressure redistribution compared to smaller angles. A position of 30° tilt combined with 120° recline is effective in relieving pressure on the ischial tuberosities and the buttocks.
O PROFMAT e as relações distintivas no campo da matemática
(Universidade Federal de São Carlos, 2017-02-10) Farias, José Vilani de; Vilela, Denise Silva; https://lattes.cnpq.br/8155152145332951; https://lattes.cnpq.br/3915260629619142
Several national and international studies have addressed the teacher training model in the past decades. A large number of educators, including mathematics teachers, have focused on the theme of mathematics teacher training in Basic Education seeking to discuss, among other topics, the necessary knowledge for teaching practice. In this context, changes in the Brazilian legislation and the institutional support of the government were also observed - factors that fostered teacher training courses with the aim of improving education in the country. The Professional Master's Degree Course in Mathematics (Profmat) is among these initiatives. The Profmat came into force in 2011, having in-service Basic Education mathematics teachers as their target audience. The choice of Profmat as the object of this study is justified because of its size and scope: the number of students enrolled and trained; the number of participating institutions; the Program investment, which exceeds that of other professional master‘s degree courses, including the granting of scholarships. This choice is also justified because Profmat was designed and implemented, and is administered by the Brazilian Mathematical Society (SBM) and the National Institute of Pure and Applied Mathematics (Impa), that is, by professional mathematicians who do not develop research addressing teacher training and do not establish interlocution with researchers in this area. The following questions are posed with reference to studies on teacher training: If the scope of this Program is justified by the need and importance to enhance the ability of teachers in favor of Basic Education, how to justify it if the emphasis of this professional course is in mathematics education aiming more comprehensive knowledge on specific contents and with few disciplines focused on the discussion of educational problems? How to justify the fact that a program with this characteristic - not attending the demands of in-service teachers - become a model for other programs in other areas, such as Physics, Languages, History, etc.? To this end, the theory of Pierre Bourdieu with the concepts of habitus, field, and capital was used. The sociological investigation, based on the notion of mathematics field, allowed the understanding of Profmat as a strategy to value a way of seeing and doing specific mathematics that, owing to its distance from the teaching practice, does not contemplate the specificities and does not meet the needs of teacher practice.