Browsing by Issue Date, starting with "2012-03-27"

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Efeitos de spin em diodos de tunelamento ressonante tipo-p
(Universidade Federal de São Carlos, 2012-03-27)
Galeti, Helder Vinicius Avanço
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Gobato, Yara Galvão
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https://lattes.cnpq.br/7558531056409406
;
https://lattes.cnpq.br/3876752605313288
In this work, we have investigated the spin effects in p-i-p GaAs/AlAs resonant tunneling diodes under magnetic field parallel to the tunnel current. The spin-dependent tunneling of carriers was studied by analyzing the current-voltage characteristics (I(V)) and the right (+) and left (-) circular polarized PL from the contact layers and the QW as a function of the applied bias. We have observed that the polarization degree from QW and contact emission is highly bias voltage sensitive. For low voltages the QW polarization exhibits strong oscillations with values up to 50% at 15 T and sign inversions for the voltages corresponding to the resonant tunneling of carriers into the well. The GaAs contact emission shows several bands including the indirect recombination between free electrons and holes localized at the 2DHG formed at the accumulation layer (2DHG-e). We have evidence that the spin polarized hole gas can contribute to the circular polarization degree of carriers in the QW. However, our results show that the circular polarization of the carriers in the QW is a complex issue which depends on various points, including the g-factors of the different layers, the spin-polarization of carriers in the contact layers, the density of carriers along the structure and the Rashba effect. The temporal evolution of the spin-polarization carriers was also investigated. We have measured the time-resolved polarized PL emission from the GaAs quantum well (QW) of a p-i-p GaAs/AlAs Resonant Tunneling Device (RTD). We have used a linearly-polarized Ti:Saphire laser and tuned below the QW absorption edge. Therefore, the electrons are created solely at the top GaAs layer and with no defined spin polarization. Under applied bias, the tunneling holes from the p-doping contact attain a quasi-stationary distribution along the RTD structure, while electrons are only photocreated during the pulse excitation with a ps Ti:Sa laser. These photogenerated electrons are driven by the applied bias and tunnel into the QW, where they might recombine with holes or tunnel out of the well. Under illumination, the current-voltage characteristics of the device present two additional features attributed, respectively, to resonant and -X electron tunneling. Optical measurements for biases where these two alternative transport mechanisms have competitive probabilities revealed an unusual carrier dynamics. The quantum well emission is strongly delayed and we observe a remarkable nonlinear effect where the emission intensity decreases at the arrival of a laser pulse. We propose a simple model that adequately describes our results where we assume that the indirect transition rate depends on the density of electrons accumulated along the structure. Under magnetic field, the PL transients reveal two rather distinct time constants, a short time ( ~ 1 ns) and a long one, which is longer than the laser repetition time (> 12 ns). The bi-exponential behavior indicates additional electron-tunneling processes, which may be associated to indirect tunneling through X-AlAs levels and tunneling of hot vs quasiequilibrium carriers at the accumulation layer. Immediately after the laser pulse, while the faster tunneling process dominates, the QW emission shows a rather small polarization. As the faster tunneling process dies out, the polarization increases to a value that remains approximately constant along the whole transient. This result demonstrates that electrons tunneling through these two distinct processes should present different spin-polarization values. We have also observed that at low biases, around to the expected -X resonance , the QW polarization is very sensitive to the excitation intensity, showing a signal inversion as a function the laser intensity. We attribute this effect to a critical dependence of the electron polarization on the occupation of the various levels involved on the process. Furthermore, at large biases, the long decay component almost disappears for low-excitation conditions and show an unusual time-dependent polarization behavior under high-excitation regime. For the analysis of this complex dynamics, we have also considered the process of tunneling out of the QW, which should become more effective, competing with the radiactive recombination process under high bias voltages. Finally, our results reveal new insights on the mechanisms that determine the spin-polarization of carriers tunneling through a doublebarrier structure and can be explored to develop spin-filter devices based on a RTD structure.
Responder por exclusão em treinos de discriminação condicional com estímulos temporais por universitários
(Universidade Federal de São Carlos, 2012-03-27)
Cippola, Nathália Sabaine
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Domeniconi, Camila
;
https://lattes.cnpq.br/9684535663947328
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https://lattes.cnpq.br/1911605025436199
Choose by exclusion has been extensively investigated and documented in different human populations. The pattern of conditional discrimination of an undefined stimulus obtained for an undefined model when possible experimentally defined choices exist has attracted the attention of researchers interested in symbolic processes such as vocabulary acquisition. Studies employing concrete stimuli have generated compelling data at the same time that they have also highlighted the need for refining knowledge about the properties of the stimuli controlling the response. The utilization of a onedimensional stimulus, like time, could add empirical data about the exact moment when the participant starts to see the undefined stimulus as being different from those used during training. Temporal stimuli have been applied in many investigations of temporal perception. In this context, this work aims to verify how university students respond to exclusion tasks and generalization tests using temporal stimuli as the stimulus mode,on the basis of double temporal bisection trainings. Forty-four university students aged between 18 and 26 years participated in this study, conducted under four different experimental conditions. For the first condition, training consisted in the formation of two conditionals between stimuli lasting 0.5 and 2 seconds for the colors red and green (first bisection), and the relation between stimuli lasting 2 and 8 seconds for the colors blue and yellow (second bisection).For the second condition, the model stimuli lasted 0.3 and 1.2 seconds for red and green, and 1.2 and 4.8for blue and yellow. Models with even shorter duration were utilized for the third and fourth conditions, 0.2 and 0.6,and 0.6 and 1.8 seconds for red and green, and blue and yellow, respectively. The other difference between the conditions lay on the stimulus mode; i.e., visual (time during which a black square remained on the screen) for the first three conditions, and auditory (time during which a beep could be heard) for the last condition. Once the baseline was established, we conducted five blocks of generalization tests with attempts consisting in the presentation of model stimuli lasting for a time period different from the trained periods and undefined and defined comparison stimuli (colors). The generalization test results revealed that the preference for red diminished with longer stimuli, and that the preference for yellow followed an inverse trend. Compared with blue, the choice of green was more frequent during shorter time intervals. As for the Exclusion Test, there was preference for defined stimuli compared with stimuli closer to the trained ones and for undefined stimuli compared with periods less close to the trained ones. These findings contribute to the investigation of responding by exclusion, since there is preference for the undefined stimulus compared with models never seen previously, especially if the models are distant from the trained ones. The generalization data differed from those achieved for non-humans, which opens a discussion about temporal discrimination learning and the role of verbalization and counting.
A construção de significados sobre letramento e seus recentes estudos durante a formação inicial e contínua de professores de língua estrangeira
(Universidade Federal de São Carlos, 2012-03-27)
Jesus, Deborah Nathalia Silva de
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Paula, Sandra Regina Buttros Gattolin de
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https://lattes.cnpq.br/9228036521343293
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https://lattes.cnpq.br/7388658055234525
The contemporary period is marked by technological development and by economic, political, cultural and social changes influenced by globalization. Such changes had its impact on Brazilian education, encouraging researches and new proposals for education, in order to adapt it to new goals and needs of society. It is intended to leave behind teaching practices based on a banking model of education and to introduce new concepts and technologies, such as literacy and its more recent studies, such as multiliteracies, new literacies and critical literacy. The school has the responsibility of forming critical citizens, prepared for social and political interaction and for new demands of labor market. Meanwhile, teachers must be updated to understand, discuss and work in the classroom with the new guidelines for education, as well as to reflect about their practice. Foreign language teachers, especially of English, the language of globalization, have also the challenge of affirming the social and educational role of their discipline. This research is interested, therefore, in understanding how knowledge about educational theories is constructed by English teachers in initial or continuous formation. The concern with the theoretical knowledge construction by teachers is justified by its importance for the development of an informed and conscious practice, in which the teacher can explain the process of teaching, analyze it and, above all, transform it.
O dialogismo e a construção de sentido nas cartas encíclicas do papa Bento XVI
(Universidade Federal de São Carlos, 2012-03-27)
Branco, Nanci Moreira
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Miotello, Valdemir
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https://lattes.cnpq.br/9131819326282708
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https://lattes.cnpq.br/8778865168706085
This study aims to analyze how the dialogical relationships and construction of meaning are built in current Catholic religious discourse, here represented by the encyclical letters of Pope Benedict XVI. I understand that even a discourse as established as the religious it is influenced by several others with which they share and to which they oppose ideas or use them to establish the meaning of the discourse. Thus, the dialogism and construction of meaning will be observed in the clash that occurs between the texts of the pope and the present discourses in society in different contexts, explicity and implicity referred to by the author, or even the discourses that are formed in different contexts in which these themes are inserted. So, the developed analysis will seek to understand, from the observation of dialogism in the documents in question, how to organize such discursive genre, and then establish, from the undeniable formation of extraverbal on the verbal, which is the relationship they have with these texts that circulate in society. I therefore consider that dialogical relations enable convergence or divergence, acceptance or refusal. In that way, one must do the question: what kind of opposing discourses should they keep deleted to preserve the hegemony of the official discourse? Which discourses are confronted with it? A discourse that intends to be dominant it tends to exclude others, not belonging to their universe that are not accepted or are discredited. The fundamental question of this analysis is therefore to understand the discourses of which we must defend and discourses to which we must resort to form the intended meaning in the encyclical letters in Authier Revuz (1990): that another one needs to defend, the other is needed to resort to be formed (p.31). Hence, this analysis seeks to verify how it happens, in the language, the confrontation of ideas which constitutes the discourse of this letter, analyzing how the voice of the Other is part of such discourse. The thought that will guide this research will be based on studies of the Russian philosopher Milkhail Bakhtin on Dialogism and Ideology.
Conferências de políticas para as mulheres: potencialidades e limites participativos
(Universidade Federal de São Carlos, 2012-03-28)
Magrini, Flávia Mello
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Cepêda, Vera Alves
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https://lattes.cnpq.br/4917331423373631
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https://lattes.cnpq.br/2488821023239417
Identificação e estudo do fungo Mucor circinelloides isolado do tronco de Pinus taeda, com ênfase em biotransformação da carvona
(Universidade Federal de São Carlos, 2012-03-28)
Santos, Gabriel Franco dos
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Rodrigues Filho, Edson
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https://lattes.cnpq.br/3667941735597178
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https://lattes.cnpq.br/3896543395330784
Identification and study of the fungus Mucor circinelloides isolated from the trunk of Pinus taeda, with emphasis on the carvone biotransformation. Fungi associated with plants have been studied ripping seeking the discovery of new substances and the understanding of the ecological interactions between plants and microorganisms. This study aimed to identify a fungus associated with the trunk of Pinus taeda using morphological analysis with images obtained by optical microscopy and scanning electron microscopy (SEM), genetic sequencing of the 18S ribosomal region, and proteome analysis by MALDI-TOF. The fungus was identified as Mucor circinelloides and its metabolism was studied. A mixture of 3-epiergosterol and ergosterol, glucosilceramidas mixture, and 3-glucopyranosyl-sitosterol were identified. The emphasis of this work was on the biotransformation of carvone, which is one of the main monoterpenes found in nature and one of the most commercialized. From the biotransformation experiment it was possible to isolate two trihydroxylated products and also dihydrocarvona, dihydrocarveol and neo-dihydrocarveol identified by GC-MS. The biotransformation products were identified by GC-MS and were proposed a pathway biotransformation. After that was performed also an estimative of production for some products and consumption estimated of (4R) - and (4S)-carvone, which is consumed in less than four hours of the experiment, showing a very rapid metabolism as reported in several genera of Mucor.
A produção de sentidos e significados matemáticos por estudantes do último ciclo do ensino fundamental por meio da leitura da obra "O homem que calculava"
(Universidade Federal de São Carlos, 2012-03-28)
Paez, Gisele Romano
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Sousa, Maria do Carmo de
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https://lattes.cnpq.br/6637658562543505
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https://lattes.cnpq.br/8273301804112624
This research aims to analyze the production of meanings that were articulated by students of grades of elementary school , while reading the book : " The Man Who Counted ." Thus , based on the assumption that reading literary texts in mathematics classes can instigate the imagination nurture the production of meaning not only to mathematics in everyday situations as experienced by students . Therefore , if selected for this study the work of Malba Tahan . It is driven by the following research question : what are the meanings mathematicians that can be produced by students of 8th and 9th grades of elementary school , a public school in the city of São Carlos , the state of São Paulo , from reading the stories of the book " the Man who Counted ?" . It is based primarily on studies of Lev Vygotsky , for the study of the production of meaning and meaning from the word , Bento de Jesus Caraga and George Ifrah , for the production of meanings to mathematical content through the history of mathematics . And is qualitative . Data were built in ten encounters were videotaped and analysis category was defined retrospectively . The analysis was made from a unit of meaning , descriptive - analytical nature of the role of the written and spoken word in the production of meanings for the mathematical content . As a result one can point out that the reading of literary texts in mathematics classes exceed the production of meaning in mathematics , arousing sense to everyday practices through relationships made between school subjects , not just math , and life . It was also possible to detect the difficulty of specific symbolic representation of mathematics especially in situations requiring a fractional representation of the situation , allowing us to ask: to what extent the way we teach mathematics with its own representation is being appropriated by the student as a way of interpreting the world ?
Ensino de espanhol para brasileiros : das crenças à prática docente
(Universidade Federal de São Carlos, 2012-03-28)
Vieira, Dark dos Santos
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Viana, Nelson
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https://lattes.cnpq.br/6252579012192711
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https://lattes.cnpq.br/1356347525580260
In recent years, we have observed that the presence of the Spanish language teaching in regular schools has been expanded gradually. However, even in the context of teaching-learning favoring of the Spanish language, it is quite frequently to hear from professionals in other fields and language learners that the broad similarity between Portuguese and Spanish facilitates communication among speakers of the two languages, and for that reason, Portuguese speakers would not need to devote themselves so deeply and systematically to the study of Spanish (or vice versa). In the field of Applied Linguistics around the same period, the number of researches focusing on beliefs related to the teaching-learning language process have increased and the results indicate the need for knowledge of teacher beliefs (trainers and training) so that one could achieve critical-reflexive education. From these findings, this ethnographic-based research developed under an interpretative perspective aims to investigate the perceptions and beliefs of Spanish teachers on the teaching of this language for Brazilians, and see how the relationship of the beliefs of these teachers with their context and their practice in the classroom is characterized. The participants of this survey were teachers of Spanish for Brazilians students in the metropolitan region of Campinas, São Paulo, and as instruments for data collection, we used a mixed questionnaire (with open questions and items in scale), interviews with teachers, field notes and recordings lessons in audio and video. This study took place on the basis of discussions on approaches to Teaching, teaching-learning language and beliefs. The data show us that, in general, the practice of teachers is guided by a system of beliefs and assumptions that underlie their approach to teaching. In addition, we also note that both beliefs about the approach of teaching have a strong relationship with the teaching context.
Correspondência fazer-dizer : variáveis de controle e condições de manutenção e generalização
(Universidade Federal de São Carlos, 2012-03-29)
Cortez, Mariéle de Cássia Diniz
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Rose, Julio Cesar Coelho de
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https://lattes.cnpq.br/3386857761295187
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https://lattes.cnpq.br/7927746584626515
The present proposal is based on the assumption that verbal responding is an operant behavior established and maintained by reinforcement contingencies. Study 1 evaluated the effects of three different correspondence training methods on the maintenance of eleven children s accurate self-report. Doing consisted of reading aloud a written word presented on a computer s screen. Saying consisted of reporting on the accuracy of the textual response after the computer s automated feedback. Following report accuracy evaluation, participants were assigned to different correspondence training methods. Five children were exposed to Training A (continuous reinforcement), three to Training B (continuous and intermittent reinforcement plus instructions), and the remaining were exposed to Training C (continuous and intermittent reinforcement only). After training criteria was met, participants were re-exposed to report accuracy evaluation sessions. Follow-up sessions were then conducted 30 and 60 days later. All training methods were effective in maintaining accurate self-reports for eight participants. Low accuracy during initial sessions (report accuracy evaluation) seemed to predict low maintenance over time. Study 2 investigated the role of the audience (computer, experimenter, and peer) on children s self-report accuracy. Participants were six children who exhibited high do-say correspondence during report accuracy evaluation sessions. The Audience Test evaluated the frequency of accurate reports as a function of different audiences. Only the correct and accurate reports were followed by points. The amount of points required to obtain the high preferred item, however, was higher than the amount received during the session. At the end of each session, participants reported how many points they obtained. Self-report accuracy was evaluated in three conditions: while engaging in the task, while reporting to the audiences, and while choosing the item. Five out of six participants self-report accuracy decreased in at least one of the three conditions as a function of the different audience s presence. After correspondence training was conducted, previous do-say correspondence levels were recovered. Audience seemed to be a relevant controlling variable on children s self-report accuracy since the presence of different audiences controlled different patterns of correspondence. Study 3 investigated the effects of errors on six children s self-report accuracy as a function of the nature of the task (academic and nonacademic), and verified generalization of a do-say correspondence training across tasks. Doing consisted of reading aloud written words, playing a computer game, announcing the result of mathematical operations, and naming different auditory or visual stimuli related to music. During baseline, the frequency of corresponding reports was evaluated as a function of the different tasks presented. Correspondence training was conducted, initially, only to the task in which participants exhibited the lowest levels of accuracy. After training criteria was met, generalized dosay correspondence of untrained tasks was then tested. Academic tasks produced the lowest levels of correspondence during baseline sessions. Four out of six children exhibited generalized say-do correspondence after the first correspondence training employed and the remaining, after a second training was conducted. Results indicated do-say correspondence as a generalized operant behavior.
Comportamento dos preços de terras em região de fronteira agrícola e em áreas tradicionais
(Universidade Federal de São Carlos, 2012-03-29)
Ferro, Aline Barrozo
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Castro, Eduardo Rodrigues de
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https://lattes.cnpq.br/5702172673123334
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https://lattes.cnpq.br/1742640723524757
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Figueiredo, Adelson Martins
This study aims to evaluate the impact of some factors on prices of agricultural land in three different regions: agricultural frontier (in the south of Maranhão, south of Piauí, eastern region of Tocantins and west of Bahia), transition area (relatively recent agricultural use of the land; however, it already represents a major soybean producing region, such as the Central-Western region in Brazil) and developed (more traditional agricultural areas, such as the South of Brazil). The period of the analysis is from 2002 to 2010, due to the recent availability of prices of regional lands. Several studies regarding the land market were analyzed; consequently, some factors related to the revenue obtained with land, to the technological level, to the infrastructure, to the need of credit, to the availability of land to expand crops and to one factor linked to expectations of agents. The elasticity in relation to the land price was obtained, using the econometric model of panel data. Soybean prices, which represent the revenue of land, had a positive relation with the price of this factor. Moreover, it was possible to verify that, in less occupied regions, an increase in the demand for area may bring negative impacts on its prices, because of the higher elasticity of the land supply and the possibility to convert raw lands and pastures in agricultural areas. This occurs because the land conversion shifts the supply curve to the right, which might impact negatively the land price. On the other hand, in the developed area, the relation is positive, since the land supply is almost inelastic. The factor of speculation was very important in the agricultural frontier region, differently from what was observed in other regions, which has highlighted the sharp interest of investors groups interested in the potential of the land valuation in that region in the period considered.
Reação de deslocamento gás-água em catalisadores de platina suportados em TiO2-CeO2
(Universidade Federal de São Carlos, 2012-03-29)
Cesário, Gabriel
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Assaf, José Mansur
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https://lattes.cnpq.br/9563312407691130
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https://lattes.cnpq.br/0960412419762463
In this work platinum catalysts supported on CeO2, TiO2, TiO2-CeO2 were prepared for application in water gas shift reaction also called Shift or well known by the letters WGSR - Water Gas Shift Reaction. The mixed titanium dioxide modified with cerium dioxide supports and platinum supported catalysts were obtained by the wet impregnation method, the two supports of titanium dioxide (Degussa and Alfa Aesar) was stabilized by thermal treatment and cerium dioxide support was obtained by thermal decomposition of its precursor. The supports and catalysts were characterized by fluorescence spectroscopy X ray (FRX), X ray diffraction (XRD), the BET method for specific area, CO chemisorption and temperature programmed reduction (TPR). On initial tests the catalysts were activated in situ and tested for WGSR ranging systems that includes the HTS (High Temperature Shift) at 450 350 ° C and LTS (Low Temperature Shift) at 350 200 ° C, and then tested only under LTS conditions. The composition of effluent stream from the reactor was analyzed online by gas chromatograph. It was noted that low charges of cerium oxide is sufficient to enhance the activity and stability of the catalysts supported on mixed oxides when compared with catalysts supported on bare oxides. The effluent stream from the reactor showed compositions similar to those expected when taken into account the ratio H2O/CO. Thus, it was concluded that Pt/Ti-CeO2 is a promising catalyst for application in WGSR reactor.
Tratamento metrológico e quimiométrico de dados de ressonância magnética nuclear para amostras de biodiesel em diesel
(Universidade Federal de São Carlos, 2012-03-29)
Gambarra Neto, Francisco Fernandes
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Ferreira, Antonio Gilberto
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https://lattes.cnpq.br/3676462220401452
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https://lattes.cnpq.br/8404572138177315
The development of instrumentation in Nuclear Magnetic Resonance (NMR) increased the sensitivity of the technique, allowing samples in micro and nanogram scale can be examined. These new technologies enabled the NMR technique was seen as an analytical tool for the quantification of substances in addition to their use in identifying as traditionally did. Quantitative Nuclear Magnetic Resonance (qNMR) is a very important area that is not widely used in analytical chemistry, with the need for a validation study to verify its ability to quantify by a metrological point of view. The application and validation of methods minimize the potential problems associated with the analytical method and also lends credence to the method studied, providing comprehensive information about many important aspects that reflect the behavior and reliability of the method. The validation studies of methods RMNq were performed in accordance with ISO / IEC 17025 and ISO GUM. The validation of the method is followed by measuring the uncertainty of measurement qNMR and its importance has been widespread in the analytical chemists area and also in the chemical society in general. The rules for establishing chemical activity as a source of patterning the selectivity studies, investigating the effects of interferents likely in the samples, and for the NMR technique, it is superior to many other analytical instruments. Therefore, the objective of this study was to provide quantitative and alternatives tools, taking into account the metrological quantification of substances by 1H NMR, which is something absolutely new for the Brazilian market. The measure of the selectivity was performed using quantification chemometrics in the spectra of 1H and 13C NMR. Metrology of the main interfering in the 1H NMR technique was studied to quantify the levels of biodiesel in commercial samples and standards of diesel in different proportions in the mixture of biodiesel BX. This study led to the separation of two sets of samples which, by classification using the chemometrics algorithm Successive projection algorithm - Linear Discriminant Analysis (SPA-LDA), are widely separated in diesel fuel containing sulfur in 1800 and 500 ppm . The selectivity was calculated by the quantification chemometric by the algorithm SPA - Multiple linear regression (SPA-MLR) of sulfur content, the density at 20°C, the distillation temperature to 50% and 80% of diesel oil, the cetane number and flash point compared to the results obtained by laboratory (Laboratório de Combustíveis do CCDM/DEMa Universidade Federal de São Carlos) accredited by the ANP (Agência Nacional de Petróleo e Biocobumstíveis).
Integração do processo de cristalização de frutose por adição de antissolvente
(Universidade Federal de São Carlos, 2012-03-29)
Crestani, Carlos Eduardo
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Giulietti, Marco
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https://lattes.cnpq.br/7703659740618915
;
https://lattes.cnpq.br/4466916726010127
Fructose (C6H12O6) is a monosaccharide with increasing industrial interest, and with some advantages over other sugars, facts that have motivated many studies about its production from its aqueous solution, by crystallization. Fructose crystallization occurs, in general, with the addition of ethanol as anti-solvent, aiming the reduction of its solubility and metastable zone width. Addition of ethanol makes feasible fructose crystallization, however, generates other negative factors to the process, as economically, because of its cost, as environmentally, because of the generation of the mother-liquor as a highly concentrate ethanol residue. These factors motivated the study of separation and reuse of the mother-liquor, recycling both ethanol and the diluted solution of non-crystallized fructose back to the process. Besides, the process was integrated into the calcium gluconate enzymatic production, through the reuse of its byproduct as raw material of the process of this work. Because of the absent of experimental data in literature, some methods of calculation of the vapor-liquid equilibrium (VLE) of the ternary solution were tested and compared, providing the choice of some of them to determine the equilibrium data. The method which obtained the best results was the AUNIFAC, and this method was used to provide the energy calculations of the process, by the evaporation and distillation temperature calculations. The cost of energy together with the replaced ethanol, were used to determine the operational cost, allowing the comparison of different operational conditions of the global process. With temperatures above 100°C in laboratorial experiments, the solution became yellow, a behavior of fructose caramelisation. It can occur because of the thermal degradation of fructose producing hydroxymethylfurfural and it prejudices the crystallization process. Because of it, it is necessary to avoid temperatures above 100°C. Finally, the integrated process made feasible crystalline fructose production by crystallization.
Aísthesis e teoria da percepção no Teeteto
(Universidade Federal de São Carlos, 2012-03-29)
Silva, Daniel Reis Lima Mendes da
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Souza, Eliane Christina de
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https://lattes.cnpq.br/5658382257368048
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https://lattes.cnpq.br/7036491650112900
In this thesis, we investigate in the first part of the Theaetetus how Plato develops the concept of aísthesis, demonstrating that at first he alternates it between the senses of mental perception and bodily sensation, and finally fixed it as mere passive reception of data from the five senses. This definition has as its objective, unlink it from the character of opinion, that Protagoras associated to the term, while inserting it into the size of the sensible world, whose key feature is the constant change. From this viewpoint, we investigate the centrality of the sense of aísthesis within the theory of perception shown in the secret doctrine, in this dialogue, which in our view, would be a first attempt of Plato to a descriptive theory of perception that explains how we capture sensitive data by through the soul, accepting shares in an effort dialectical thesis of Protagoras and Heraclitus. We also analyze the link between the theories of Theaetetus, Protagoras and Heraclitus exposed in this first part of the dialogue, and how they interrelate in order to make clear that Plato maintains intact his Theory of Forms.
“A apoteose da imagem”: cineclubismo e crítica cinematográfica no Chaplin-Club
(Universidade Federal de São Carlos, 2012-03-29)
Santos, Fabricio Felice Alves dos
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Araújo, Luciana Sá Leitão Corrêa de
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https://lattes.cnpq.br/9890886509956837
;
ttp://lattes.cnpq.br/5646532889487401
Founded in Rio de Janeiro in 1928, the Chaplin-Club is considered the milestone of ciné-clubs and of film criticism in Brazil. Since the beginning of its activities, the club used to release O Fan, a vehicle dedicated to spread the group’s ideas. The objective of this dissertation is to analyze the activities of Chaplin-Club and its members’ reflections on cinema. Having as main source the nine issues of O Fan, this work aims to establish a dialogue among the different conceptions of cinema expressed by the club members and evaluate the set of concepts applied by them in the construction of their critical parameters, in order to present the particularities of Chaplin-Club’s thoughts and its specificity in the Brazilian context of the time.
Eficiência da ação fotodinâmica em Mycobacterium massiliense
(Universidade Federal de São Carlos, 2012-03-30)
Arantes, Danilo Pastori
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Souza, Clovis Wesley Oliveira de
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https://lattes.cnpq.br/0781683628437007
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https://lattes.cnpq.br/6837759934908545
In Brazil there was an increase of post-surgical infections by rapidly growing mycobacteria, mainly Mycobacterium massiliense, leading the Agency for Sanitary Surveillance (ANVISA) to establish standards for the mandatory notification of cases occurring nationwide. In order to deal with a major public health problem, this study aimed to determine the efficiency of using antimicrobial photodynamic inactivation (PDIa) in Mycobacterium massiliense for future use in the treatment of agent infections. The objective was to test in vitro technique the PDI to control Mycobacterium massiliense to determine the best light dose and concentration of each photosensitizer (FS). To accomplish this search were used two FS: Photogem® and salt Curcumin (N-Methyl-D-Glucominato of Curcumin, 31.8%). As a light source for radiating a BioTable ® operated at 630nm (red light) for Photogem ® and 460nm (blue light) to the salt of curcumin. After the standardized inoculum was added to the sample analyzed in triplicate to a 24 well plate which contained 500μl aliquots of the inoculum +500 μ l of the FS for the study groups tested, and the control group containing 1 ml of inoculum, and five minutes as time incubation (protected from light). After expiration of the irradiation time in accordance with the previously analyzed fluences of the tested groups and subsequent dilution of the sample to the value of 10-5, 100mL sample were plated in triplicate on 7H10 agar + OADC 10% and maintained at 37 for about 5 days with subsequent counting of colony forming units. Based on the results, they showed that FS Photogem ® until the concentration of 1000 μg/Ml was not effective in reducing the number of CFU of M. massiliense. In contrast, the FS Salt Curcumin was effective at concentrations of 1300 μg/Ml with a light dose 50 J/cm2 compared to controls. Thus, these data suggest that the salt FS Curcumin in photodynamic action is a viable alternative for reducing M massiliense when tested in vitro.
Efeitos dos herbicidas clomazone e ametrina em parâmetros funcionais da espécie de peixe neotropical Prochilodus lineatus
(Universidade Federal de São Carlos, 2012-03-30)
Pereira, Lindalva
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Fernandes, Marisa Narciso
;
https://lattes.cnpq.br/3021357484136942
;
https://lattes.cnpq.br/3342059478238761
The use of biomarkers can provide a great help in the evaluation of the damages caused by pesticides in aquatic organisms. The present study aimed to verify the toxicity of clomazone and ametryn for a tropical freshwater fish Prochilodus lineatus by using different parameters in fish exposed for 96h to clomazone (1, 5 and 10 mg.L-1) and to ametryn, as the commercial product GesapaxR500 or in its pure form, in the concentrations 2.5 and 5.0 mg.L-1, or only to water (CTR). The parameters used were: hematological; metabolic (concentration of glucose); osmoionic (osmolarity and plasmatic Cl-, Na+ e K+); biochemical and genotoxic (DNA damage). Clomazone caused hematological disturbances in P. lineatus as noted in the lowervalues of hematocrit (Hct) in 10 mg.L-1; hemoglobin (Hb), mean corpuscular hemoglobin (HCM) and mean corpuscular hemoglobin concentration (CHCM) in 5 and 10 mg.L-1, which, in general, may indicate anemia. The number of erythrocytes (RBC) presented increased values in the lowerconcentration tested for clomazone, which probable is related to the stress response, with the releasing of immature erythrocytes in the blood stream. Clomazone also activated the detoxification and antioxidant pathways of the tested animals, as shown by the increased activity of the hepatic biotransformation enzyme glutathione-S-transferase (GST) and the antioxidant enzyme catalase (CAT) in 5 and 10 mg.L-1. The reduced activity of glutathione peroxidase (GPx) observed in 5 and 10 mg.L-1 indicated efficient performance of CAT removing the H2O2, or even a competition with GST for the substratereduced glutathione (GSH). The activity of brain acetylcholinesterase (AChE) in P. lineatus was inhibited in the concentrations of 5 and 10 mg.L-1 of clomazone, showing that this herbicide has an anticholinesterasic effect on the studied fish species. Fish exposed to ametrynshowed hematological disturbances such as lower values of Hct in 2.5 and 5.0 mg.L-1 and of RBC in the concentration of 5.0 mg.L-1. The reduction of plasmatic K+ in the concentration of 2.5 mg.L-1, and the hematological alterations mentioned above, may indicate a rupture of the erythrocytes. Fish exposed both to pure ametrynand the formulated product, showed higher values of glucose as a stress response, in both concentrations tested. The two products also caused inhibition of the gill activity of Na+/K+ATPase in 5.0 mg.L-1. The concentration of 5.0 mg.L-1 caused significant decrease in the malondialdehyde (MDA) levels, leading to the conclusion that ametrynor its formulated product do not generate lipidic peroxidation. DNA damages in the erythrocytes of P. lineatus were x observed in the concentration of 5.0 mg.L-1 of ametryn and GesapaxR 500, showing the genotoxicity of ametryn, probably because it binds directly to the genetic material of the fish. The results presented here allow concluding that the pesticides ametryn and clomazone interfere in the functional parameters of P. lineatus and can compromise the health of these animals
Emprego da organocatálise como uma ferramenta da química verde em reações de adição conjugada : estudos visando a síntese de anéis indólicos
(Universidade Federal de São Carlos, 2012-03-30)
Feu, Karla Santos
;
Paixão, Márcio Weber
;
https://lattes.cnpq.br/3773908504964104
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https://lattes.cnpq.br/1138069644348816
Organocatalysis has emerged as a powerful synthetic paradigm and has accelerated the development of new methods to make diverse chiral molecules. In addition, the small chiral organic molecules used to accelerate asymmetric reactions, In this regard L-proline and its derivatives have risen to gaining prominence. In the present work, we have designed and synthesized LProline derived organocatalysts 4 a-e bearing with the alkyl chain containing chalcogen moiety such as Sulfur & Oxygen and to evaluate their application as catalysts in enantioselective reactions. The synthesized catalysts 4a-e were then employed as organocatalysts in enantioselective conjugate addition of malonates to alfa, beta- unsaturated aldehydes in an environmentally benign approach. Several different reaction conditions were screened and enantiomeric excess upto 96% with good to excellent yields was achieved for the Michael adducts. The best result was achieved for organocatalyst 4b in aqueous reaction conditions. Exploiting the application of the synthesized Michael adducts 5a-i, we then decided for the synthesis of the biologically important substituted indole and it was successfully accomplished with good yields along with excellent ee.
Catalisadores bimetálicos de Co e Ni aplicados à reforma à vapor do etanol: propriedades de oxiredução na resistência à deposição de carbono
(Universidade Federal de São Carlos, 2012-03-30)
Braga, Adriano Henrique
;
Bueno, José Maria Corrêa
;
https://lattes.cnpq.br/0157452280626031
;
https://lattes.cnpq.br/7251309652981943
The effect of variation of cobalt (Co)/nickel (Ni) composition in catalysts based on these transition metals was evaluated focusing mainly in the oxi-reduction properties and their relation to carbon deposition in the Steam Reforming of Ethanol (SRE) reaction. The catalysts, with metal loading of 15 and 8 wt%, were prepared by conventional impregnation of the Co and Ni salts on the sol-gel synthesized support MgAl2O4. The characterization was performed by N2 adsorption-desorption isotherms; X-ray diffraction (XRD); temperature programed reduction (H2-TPR); thermogravimetric analysis (TGA); scanning electron microscopy (SEM) and transmission electron microscopy (TEM); X-ray absorption near edge spectroscopy (H2-XANES), in situ extended X-ray absorption on fine structure spectroscopy (SRE-EXAFS) and Raman spectroscopy. The catalytic tests were done in the temperature range of 250 to 700°C and the conversion and products distribution dependence on the metal loading and composition were evaluated. Reduction profiles and diffraction patterns lead to believe that occur the formation of a spinel NiCo2O4 in the weight ratio 1Co:1Ni during calcination. Such spinel once reduced yields an alloy Co-Ni, accordinto to TEM images and EXAFS data. The alloy formation, although it is hard to characterize, seems to be determining factor on carbon deposition resistance on the catalyst surface during SRE. Carbon deposition, as addressed by TGA and SEM, is strongly sensitive to metal loading, being severe on monometallic samples with higher metal loading; independent of the loading, the bimetallic catalysts in the proportion 1:1 are resistant to carbon deposition. SRE-EXAFS showed that these catalysts didn t oxidize during reaction, differing from Co catalysts, where the equilibrium between oxide and metallic sites controls the ethanol activation and carbon oxidation rates.
A oferta de serviços ambientais na bacia hidrográfica dos rios Sorocaba e Médio Tietê
(Universidade Federal de São Carlos, 2012-03-30)
Kawaichi, Vanessa Mayumi
;
Faria, Rosane Nunes de
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https://lattes.cnpq.br/1172221536399083
;
https://lattes.cnpq.br/8307217059333898
;
Almeida, Alexandre Nunes de
The present study aims to estimate the supply of environmental services Sorocaba Rivers Basin and Middle Tietê, located in the central-southeastern state of Sao Paulo. The focus of the environmental service is given to the hydrological services, which are responsible for providing farmers in the region. Thus, from the provision of environmental services in the Basin, we estimated the value of PES to farmers based on the opportunity cost of changing agricultural practices on farms in the region. The methodology is based on the opportunity cost of changing a conventional practice for a conservation practice. The opportunity cost was obtained from the comparison between the yield of each crop analyzed by adopting the conventional practice and practice conservation. Thus, we analyzed the yields of major crops Basin (coffee, corn, beans, potatoes, sugar cane, orange, tomato, onion, grapes, rice and cassava), comparing the difference between the yields for both practices. The classification for conservation practice and conventional practice followed at the discretion of the forest area of the basin, considering the municipalities with an area of forest above average as conservation and below average, as conventional. Thus, the forest area was used as a proxy for measuring the environmental service in question, knowing that the preservation of vegetation provides a number of benefits, including conservation of water resources. The results show that the estimated values of PES for the main crops of the Basin can range from R$100/ha/year to R$30.000/ha/year. In relation to the cultures analyzed in this study, we can say that with the highest potential for implementation of programs for PES were the crops of rice and cassava, which, besides having more profitable return for the conservation practice, have a initial offering of high environmental services and the lowest values for PES. Cultures orange, tomato, onions and grape also have an initial supply of high environmental services, however, PES values are estimated quite high in comparison with other cultures, thereby implementing programs to increase the supply PES environmental services in this case should consider how much the payment would compensate for the provision of environmental services provided by these cultures.