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Caracterização da resistência à corrosão de ligas inoxidáveis Fe-Mn-Si-Cr-Ni-(Co) com efeito de memória de forma
(Universidade Federal de São Carlos, 2011-03-03) Rovere, Carlos Alberto Della; Kuri, Sebastião Elias; https://lattes.cnpq.br/6842072916153866; https://lattes.cnpq.br/8141224513975606
In this work, the corrosion behavior of three Fe-Mn-Si-Cr-Ni (Co) shape memory stainless steels (SMSS) in aggressive environments was characterized. The electrochemical corrosion behavior in 0.5 M H2SO4 solution was obtained by potentiodynamic polarization, linear polarization, potential decay curves, electrochemical impedance spectroscopy (EIS), and Mott-Schottky analyses. Localized corrosion resistance was evaluated by potentiodynamic polarization measurements in 3.5% NaCl solution. The corrosion performance in highly oxidizing environments was evaluated based on immersion tests in boiling HNO3 solution. The passive film composition was analyzed by X-ray photoelectron spectroscopy (XPS). The test results were compared with that of a type 304 (SS 304) austenitic stainless steel. The three SMSSs exhibited a passive behavior in 0.5 M H2SO4 solution; however, their anodic behavior in the active dissolution region was markedly different. The passive current densities of the SMSSs were similar to that of SS 304, although the critical anodic current required for passivation was higher. The corrosion rate of the SMSSs in 0.5 M H2SO4 solution was much higher than that of SS 304. It was observed that the amount of Cr and Mn plays an important role in the corrosion behavior of SMSS. The XPS analyses indicated substantial Si content (in the chemical form of a silicate) in the anodic passive films formed on SMSS. Mott-Schottky analyses suggested that the Si acts as a dopant in the films, making them less defective and thicker than the films formed on SS 304. Due to their high manganese content, SMSSs are highly prone to pitting corrosion in chloride environments. SMSSs exhibit better corrosion resistance than SS 304 in highly oxidizing environments.
Secagem de resíduos cítricos em secador rotativo
(Universidade Federal de São Carlos, 2011-03-03) Perazzini, Hugo; Freire, José Teixeira; https://lattes.cnpq.br/2270677706718167; https://lattes.cnpq.br/2676311547535414
In this present work, an experimental study about simultaneous heat and mass transfer phenomena was carried out during the drying process of citric solid waste in a direct-heat contact semi-pilot rotary dryer, operating with continuous feed of solids. The drying experiments consisted of obtaining humidity and temperature data as function of time for the solid and gaseous phases, evaluating the influence of the operational variables of the process. The material characterization was studied in relation to the apparent and real specific masses, porosity, specific heat and hygroscopicity. The last one was determined by thermodynamic equilibrium conditions and by the thin-layer drying kinetics of the solid waste in a fixed bed dryer. In parallel, a two-phase mathematical model of lumped parameters was developed based on macroscopic balances of mass and energy for the solid and for the drying air. The differential algebraic system was solved numerically using a computer routine developed in MatLab®, where the drying process was simulated taking into consideration the particle residence time distribution inside the dryer. The comparison between the predicted and observed results showed that the model needs some improvement, but permits a preliminary qualitative analysis of the drying process.
Discriminações simples e reforçamento específico e diferencial para cada classe no ensino de leitura a indivíduos com atraso no desenvolvimento
(Universidade Federal de São Carlos, 2011-03-03) Zaine, Isabela; Domeniconi, Camila; https://lattes.cnpq.br/0665572503019533
Training procedures in researchs about the estabilishment of stimulus equivalence classes are tipically based on conditional discriminations, in wich a sample controls selection of a comparison stimulus. Proposals based on simple discrimination have been suggested in order to expand the potential of such technology and empirical model. Considering also that reinforcers are a part of stimulus equivalence class, the use of specific reinforcers to each class may assist in the emergence of equivalent stimuli classes. The preset study aimed to propose a training structure combining simple and conditional discrimination and differential and specific reinforcement for each stimulus class to teach reading of six simple isolated words from to individuals with developmental delay. Participants were 14 individuals with developmental delay enrolled in a special education institution with ages ranging from nine to 15 years. They were divided in two groups and randomly assigned to an experimental or control group. LECH-GEIC software was utilized for programming and effectuation of the teaching program, which training consisted on four phases: 1. simple discrimination between pictures 2. simple discrimination between printed words, 3. conditional discrimination between pictures with onomatopoeic auditory model. 4 conditional discrimination between printed words with onomatopoeic auditory model. Results pointed that there was a higher number of repetitions and errors in the conditional discriminations condition. There was evidence of formation of stimuli equivalence classes for all or some classes of stimuli for all participants in the experimental group. The average percentage of correct selections on symmetry and transitivity tests evaluated by BC and CB matching performances was substantially higher in post-test (CB = 81.3%, BC = 72%) compared to pre-test (CB = 45.8 % BC = 40.4%), and this difference was statistically significant (Wilcoxon Z =- 2.197, p <0.028 (BC) Z =- 2.366, p <0.018 (CB)). Reading of the training words for this group increased from a correct average percentage of 2.3% at pre-test to 53.57% at post-test (Wilcoxon Z =- 2.371, p <0.018). There were no statistical significant differences in performance between control and experimental groups at pre-tests (Mann-Whitney U), however, the experimental group, at post-tests, scored significantly higher in comparison to the control group at AC (U = 1 , 0, p <0.001), BC (U = 2.0, p <0.002), CB (U = 6, p <0.017), CC (U = 10.0, p <0.043), CRCCs (U = 8 , 0, p <0.038) relations and naming of training words (U = 0.5, p <0.001). Neither group presented generalized reading. By starting from a simple discrimination training prior to conditional discrimination, the procedure has created a situation of complexity teaching from simple to more elaborate repertories. The use of specific reinforcers may have assisted the emergence of untrained repertoires, such as AC, BC, CB relations and reading. The performance on equivalence tests and reading of some stimuli may have been hampered by multiple similarities between some written words and absence of auditory model in training phases, since onomatopoeic sounds were used as models in situations of conditional discriminations.
Distribuição vegetal ao longo dos gradientes ambientais de um estuário irregular
(Universidade Federal de São Carlos, 2011-03-03) Ribeiro, José Pedro Nepomuceno; Lima, Maria Inês Salgueiro; https://lattes.cnpq.br/2171993314203162; https://lattes.cnpq.br/5713780053868735
Transferência de funções ordinais através de classes de estímulos equivalentes em surdos
(Universidade Federal de São Carlos, 2011-03-03) Resende, Alice Almeida Chaves de; Goyos, Antônio Celso de Noronha; https://lattes.cnpq.br/3407008711535651; https://lattes.cnpq.br/9884343350716175
The bilingual approach, adopted for educating deaf people in Brazil, regards the Brazilian Sign Language (Libras) as the first language and the written Portuguese Language as the instrumental language. The acquisition of the written language may be more difficult than the acquisition of the sign language due to the differences between their ordinal grammatical structures. The ordinal grammatical structure of the written Portuguese consists in a subject verb preposition complement order, whereas the structure of the Sign Language allows not only this order, but also different combinations of the elements. Such differences usually result, for the deaf people, in a writing repertoire of the Portuguese Language that has a different grammatical order than that one used by the verbal community in which they are inserted. This study investigated variables that control the transfer of ordinal functions through classes of equivalent stimuli. The experimental stimuli used were 32 printed words divided into four stimuli categories (A1A2A3A4; B1B2B3B4; C1C2C3C4 e D1D2D3D4), corresponding to subject, verb, preposition/article and complement, respectively. The categories were taught through matching-to-sample (MTS) tasks, while the sequences were taught through constructed-response matching-to-sample (CRMTS). All participants showed the formation of four stimulus classes, and learned one sequence (A1A2A3A4). After that, they showed the transference of ordinal functions to untaught sequences. In summary, results showed the transference of ordinal functions through equivalence classes.
Estudo da alimentação de sólidos em sistemas de transporte pneumático
(Universidade Federal de São Carlos, 2011-03-03) Lopes, Cibele Souza; Freire, José Teixeira; https://lattes.cnpq.br/2270677706718167; https://lattes.cnpq.br/3627302739758354
One of the most important parts in a pneumatic conveying is the solids feeding system due its complexity fluid dynamic, besides affecting the operational stability, economical and technical feasibility and system efficiency. The purpose of this wok was to carry out a experimental study of fluid dynamic of feeding configuration for different operational conditions, made of non-mechanicals devices and reduction nozzle combinations, considering the influence in all pneumatic conveying system. The feeders applied were inclined pipe and L-valve, with and without reduction nozzle. Moreover, the spouted bed and the horizontal feeders were analyzed as well, which on their original design has reduction area for the flow. An analyses and a comparison of the fluid dynamic data obtained for feeding configurations in a pneumatic loop with 53,4 mm of internal diameter tube and transporting 1 mm glass spheres showed a relationship between the operational conditions and the type of feeder, resulting in air velocity and solid flow rate characteristics for each case . This study also gives the idea to apply reductions nozzles combined with non-mechanicals solid feeder in order to increase the solid flow rate. Up to the moment, the reduction nozzle was indicated just to get better the operation stability.
Estudo da influência de argilitos e feldspatóides em composições de porcelanato
(Universidade Federal de São Carlos, 2011-03-03) Hoffmann, Felipe Schlittler; Morelli, Márcio Raymundo; https://lattes.cnpq.br/0172837599844991; https://lattes.cnpq.br/8350754524180998
Considering the various types of ceramic tiles used today, the stoneware tile is distinguished by its aesthetic and technical characteristics, such as: very low water absorption (less than 0.5%), high mechanical strength, high abrasion strenght, high chemical and frost strenght. Commonly, a composition of stoneware tile is constituted by homogeneous mixture of plastic clay(s), kaolin, feldspar, quartz and talc of high purity. This work studied the effect of replacing the plastic clay used in the manufacture of this product, typically a clay, by a mudstone of lower refractoriness. Another object of study was to evaluate the influence of the replacement, even partially, the content of feldspar (which is the raw material most suitable flux and used industrially, around 45% by mass) for nepheline, evaluating the technical characteristics achieved in the final product. For this, emphasis was given to the use of different levels and types of trainers from the liquid phase (feldspar and nepheline) in compositions of bath with the mudstone. For comparison it was characterized, by means of physical tests, the linear shrinkage and water absorption (vitrification curve), and flexural strength of a standard composition, reported in the literature, and new compositions. In addition, it was evaluated the cycle and the level of firing (1200 ° C is the temperature industrial average), verifying the possibility of reducing consumption of natural gas, which represents the main energy source of the production process.
Deformação em canal angular de uma liga Al-4%Cu: efeito dos mecanismos de endurecimento na resistência mecânica e ductilidade
(Universidade Federal de São Carlos, 2011-03-03) Prados, Erika Fernanda; Sordi, Vitor Luiz; https://lattes.cnpq.br/8364164402481940; Ferrante, Maurizio; https://lattes.cnpq.br/6067173982945625; https://lattes.cnpq.br/8992454758111330
Internal boundaries hardening and precipitation hardening are two important mechanisms acting in metallic alloys. The former has special relevance when the grain size is reduced to dimensions below 1 μm, and this can be accomplished by a variety of Severe Plastic Deformation techniques, such as Equal Channel Angular Pressing. The objective of the present thesis is a better understanding of the strengthening mechanisms and work-hardening behavior of a precipitation hardening Al alloy subjected to Equal Channel Angular Pressing. The pertinent literature almost invariably shows that high strength goes together with low work hardening rate, that is, the stress-strain curve tends to be flat, meaning that highly deformed metals and alloys show low ductility. Among the strategies devised to counteract this effect, post deformation precipitation heat treatments seem to have a beneficial effect on the work hardening rate. In this condition precipitates would reduce the dynamic recovery rate and additionally promote some hardening. The present study was performed on an Al-4%Cu alloy, deformed by up to four passes of equal channel angular pressing and heat treated according to different schedules, including post deformation ageing. The work is divided in three sections: (i) Severe plastic deformation influence on precipitation; (ii) Correlation of strength and ductility with the Al2Cu precipitates dispersion, while the work hardening behavior is described by the relevant Kocks-Mecking curves; (ii) Study of the contribution of each of the four hardening mechanisms on final strength: work hardening, solid solution, precipitation and internal boundaries hardening. Conclusions show that a fine precipitate dispersion increases the work hardening rate by limiting dynamic recovery rate. It was also ascertained that cold deformation accelerates precipitation by a factor of three, however, precipitation hardening is swamped by the softening effect caused by the precipitation heat treatment itself.
Obtenção e caracterização elétrica de filmes finos de SnO2:Sb
(Universidade Federal de São Carlos, 2011-03-03) Conti, Tiago de Goes; Leite, Edson Roberto; https://lattes.cnpq.br/1025598529469393; https://lattes.cnpq.br/2091351741982251
The growing demand for advanced electronic devices based on nanomaterials has motivated efforts to produce nanoscale building blocks with designed functions. Transparent conducting oxide nanocrystals (TCONs) are particularly promising for the development of such devices. TCONs synthesized in an organic medium play an important role as building blocks because nonaqueous processes allow for greater control of the reaction pathways on a molecular level, enabling the synthesis of nanomaterials with high crystallinity and well-defined and uniform particle morphologies. This work describes the synthesis of highly conducting antimony-doped tin oxide (ATO) nanocrystals prepared via a nonaqueous sol-gel route in the size range of 4-7 nm, as well as insights into its electrical properties when processed as pellet and thin films. The antimony composition was varied from 1 to 18 mol% and the lowest resistivity (4.0x10-4 Ωcm) was observed at room temperature in the SnO2:8.8%molSb composition. The samples were evaluated by XRD, HRTEM, EDX, and SEM, resistivity measurements were taken in the four-probe mode in the temperature range of 77-300K and Hall-effect measurements were taken at room temperature. The preparation of crystalline ATO nanoparticles fully redispersible in organic solvents consists in one pot reaction under solvothermal treatment of tin (IV) chloride and antimony (III) chloride in benzyl alcohol at 150°C for 48h. The ATO nanocrystals were collected by centrifugation and washed twice with THF. The pellets were prepared by pressing 200mg of ATO nanoparticles under 4 MPa into a rigid die in a single axial direction through a rigid punch and the thin films produced via dip-coating deposition on quartz substrate. The results show highly crystalline nanoparticles in a monodisperse colloidal system, dependence on the shape of ATO nanoparticles as a function of Sb distribution and low resistivity.
Diálogo das teses do subdesenvolvimento de Rostow, Nurkse e Myrdal com a teoria do desenvolvimento de Celso Furtado
(Universidade Federal de São Carlos, 2011-03-03) Gumiero, Rafael Gonçalves; Cepêda, Vera Alves; https://lattes.cnpq.br/4917331423373631; https://lattes.cnpq.br/3606249612497573
The period after the end of First World War and the crisis of 1929 introduces (from the critical to the liberal economic model and the emergence of strategies planned development and alternative Keynesian of economic regulation) a new investigation problem: the issue of delay and the condition of underdevelopment. In terms of world literature, this problem has been worked in an original and vigorous way by Ragnar Nurkse in "Problems of capital formation in underdeveloped countries ", by Rostow in "Stages of Economic Development", and Gunnar Myrdal in "Economic Theory and Regions Underdeveloped . These works and authors were not only well received by the national-developmentalist intelligentsia, as strongly influenced the theory of underdevelopment of Celso Furtado. This research has two objectives: 1) identify in the dialogue established between the arguments of Rostow, Nurkse and Myrdal agreement, kept their proper proportions in the work of Furtado (fundamental author in understanding the developmental question of the years 50/60); 2) to analyze how this influence has been received, appropriate and resignified according to perspectives of Furtado in the formulation of development theory for the Brazilian industrial planning.
Diversidade funcional e funcionamento da comunidade: teste em uma área de cerrado
(Universidade Federal de São Carlos, 2011-03-03) Freitas, Juliana Ribeirão de; Batalha, Marco Antônio Portugal Luttembarck; https://lattes.cnpq.br/3893228815181339; https://lattes.cnpq.br/0492047671819262
Community functioning may be affected by functional diversity, since it measures the extent of complementarity in resource use. We tested whether there was a relationship between functional diversity of woody species and community functioning at fine-scale, using FD as a measure of functional diversity and litter decomposition rate as a surrogate for community functioning. We measured eight functional traits from a woodland cerrado community in southeastern Brazil. We tested the correlation between FD and decomposition rate, between decomposition rate and each trait separately, and between FD and decomposition rate taking into account differences in soil features. There was a non-significant relationship between FD and decomposition rate, even when we considered each trait separately. Decomposition rate was related to aluminium and phosphorus concentration in soil, but not to FD, pointing out that functional diversity was not a good predictor of community functioning. Most studies on the relationships between biodiversity and community functioning at fine scales were carried out by experimental manipulation of diversity and in temperate regions. We carried out this fine scale study as a mensurative experiment and in a tropical savanna. Our findings indicated that the relationship between biodiversity and community functioning is not so straightforward as usually assumed.
Confiabilidade humana: uma abordagem baseada na análise ergonômica do trabalho na operação de um painel de equipamento
(Universidade Federal de São Carlos, 2011-03-03) Silva, João Alexandre Pinheiro; Camarotto, João Alberto; https://lattes.cnpq.br/1427853773681255
The restructuring of production processes throughout the entire petrochemical chain brought impacts on the labor division, resulting in a series of new demands for knowledge and skills, which are added to old ones, in order to maintain the stability and reliability of the production system, under their responsibility. The objective of this thesis is to build a theoretical framework on human reliability and ergonomics as well as the observation and analysis of an oil refinery production system. It aims to identify conflicts and gaps between the strategies and actions developed by the operators as system reliability maintainance agents in their work daily routine, and the organizational managerial approach for human reliability in the company. In order to achieve these goals, the research approach adopted has the characteristics of literature review that encompasses bibliometrics and content analysis, mixing action research methodology and Ergonomic Workplace Analysis in field research. The literature review identified 304 articles about "human reliability in the ISI Web of Knowledge scientific basis, of which only 50 items are classified in the field of ergonomics (16%). The major research stream on human reliability focuses on nominal scenarios, and therefore, in the ergonomics point of view, focuses on the task, i.e., the prescribed work. Another research stream focus on the real work analysis. The Company studied has classical and a mechanistic point of view focuses on the errors identification and construction barriers through procedures, checklists and other prescription alternatives to improve performance in reliability area. It was evident the fundamental role of the worker as an agent of maintenance and construction of system reliability. There are several strategies adopted by operators to mitigate in practice the gap between prescribed and real work.
Igreja Universal e democracia no Brasil: uma abordagem sobre as transformações do fenômeno político contemporâneo
(Universidade Federal de São Carlos, 2011-03-03) Antonio, Gabriel Henrique Burnatelli de; Lahuerta, Milton; https://lattes.cnpq.br/9326718732298388; https://lattes.cnpq.br/2858698343770358
This study sought to develop as its background theme the critical dimension of the contemporary political phenomenon, focusing on its impacts in Brazil´s democratization process. Starting from this agenda, the specific goal rested in the study of social and institutional conditions for the emergence of the Universal Church of the Kingdom of God (IURD) as a political subject in Brazilian democracy. With this issue, this study tried to point out that the large stock of individuals in social subaltern conditions, the weak democratic experiment in the Brazilian republican history and the historical absence of mechanisms to build social empowerment facilitated the emergence, in recent decades, of political interests such as presented by the data collected about it from IURD: eminently corporate, unconcerned with the public sphere and with the construction of a civic culture that could guide its social bases for the enjoyment of a well understood citizenship.
Efeito da exposição à atrazina nas brânquias de curimbatá, Prochilodus lineatus (Teleósteo, Prochilodontidae)
(Universidade Federal de São Carlos, 2011-03-03) Paulino, Marcelo Gustavo; Fernandes, Marisa Narciso; https://lattes.cnpq.br/6503185330517924
The herbicide atrazine is one of the most common pesticides found in the aquatic ecosystems all over the world. In this study the effects of atrazine, at sublethal concentrations, were evaluated on the gills of Prochilodus lineatus. Juveniles P. lineatus were divided in 4 groups: control and exposed to atrazine (2, 10 e 25 μg.L-1) for 48 hours or 14 days. After the experimental periods, blood samples were taken by caudal puncture for ion plasma analusis and the gills were removed and samples were fixed for morphological analysis (chloride cell immunohistochemistry, scanning electron microscopy, histochemistry of mucous cells and histopathology) or frozen for biochemical analysis (Na+/K+-ATPase and oxidative stress enzyme activity, GSH and determination of lipid hydroperoxidation). The activity of antioxidant enzymes (SOD, CAT e GST) e lipid peroxidation increased in fish of group exposed to 10 μg.L-1 for 14 days. Although there was an increase on plasma Na+ e Cl- and osmolality in fish exposed for 14 days it was not characterized as ionic imbalance as the Na+/Cl- ratio was similar in all groups. The total number of chloride cells decreased significantly only in the group exposed to 25 μg.l-1 of atrazine (48 h) and the CC density at epithelial surface and the fractional surface area of chloride cells increase in both treatments (48 h and 14 days) in fish exposed to 25 and 10 μg.l-1, respectively. The Na+/K+-ATPase activity was not altered in any experimental condition. The number of mucous cells containing sulfated mucins decreased. Hypertrophy and disruption of lamellar epithelium and vascular congestion were the most common injuries found in the gill tissue of P. lineatus and in fish exposed to 25 μg.l-1 atrazine (14 dias) the histopathological changes index was calculate as slightly to moderate. In conclusion, the tested concentrations, which are similar to those found in natural environments, may cause alterations in the gills of P. lienatus, so as not to endanger the vital functions of the gills and homeostasis of the animal. The changes observed in the gill of P. lineatus after atrazine exposure at tested concentrations, similar to that found in the natural environment, suggested that atrazine may affect the organ function.
Obtenção e caracterização de nanocompósitos de poli(cloreto de vinila): plastisol com argila
(Universidade Federal de São Carlos, 2011-03-03) Bettio, Paola Pedroza Serpa de Biasi; Pessan, Luiz Antonio; https://lattes.cnpq.br/8276650236213537
This project aims to study the effect of adding nanoparticles in the plastisol of poly(vinyl chloride) microsuspension. The influence of two different types of nanoclay, sodium montmorillonite and organophilic montmorillonite modified with quaternary ammonium salt was evaluated, considering both the method of exfoliation of the clay and the influence of concentration. The nanoclay at a concentration of 2.5, 5 or 10 phr, was previously exfoliated in plasticizer, under the action of shear and temperature in kaule mixer. Three plasticizers were used, Diisobutyl phthalate, Diisononyl phthalate and ester polyglycolic. Experiments without the prior exfoliating clay, were also performed for validation of its influence. The plastisol was obtained by mixing the nanoclay with PVC, diisononyl phthalate plasticizer and other additives in planetary mixer. The focus of the study will be not only to investigate the influence of nanoparticles on the improvement of rheological properties, but the influence on the mechanical properties, expanding the application of this resin. As the resin obtained will be attending the main application market, the analysis will focus on characterization for this particular application. Data analysis was performed with the aid of statistical method. It was possible to affirm that type of clay and also its concentration have influence on the viscosity. The prior exfoliation of the clay was not proved to be effective. It was possible to affirm that type and concentration also have significant influence on the opacity of the spread coating. In relation to thermal stability, it was possible to observe reduction in the nanocomposites containing organophilic modified nanoclay. In relation to the mechanical proprieties, it was possible to affirm that only the concentration of the clay was significant to the result, as its increase resulted in a decrease of these properties, with the exception of the Young modulus.