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Síntese e caracterização de nanoilhas de PZT e BaTiO3
(Universidade Federal de São Carlos, 2007-09-27) Albarici, Viviane Cristina; Leite, Edson Roberto; https://lattes.cnpq.br/1025598529469393
This work presents a systematic study of synthesis and characterization of ferroelectric nanoislands. Generally three methods were had been studied: polymerized complex method (MPC), hydrothermal synthesis and nonaqueous synthesis. In order to optimize the formation of nanoislands we realized studies about influence of some experimental parameters. When we used MPC the concentration of metallic cátions (Pb2+, Zr4+ and Ti4+) in the polymeric resin, influence of the type calcination (using microwave and conventional oven), the citric acid - metallic cátion ratio (AC:Metal) and the resins deposition method were varied. The results showed that using the spin-coating deposition onto Si (100) substrate, the dilution of the polymeric resin proportionate samples with of distinct particle concentrations. Some of these regions with nanoislands. With the increase of ratio AC: Metal we had the formation of continuous films. The samples prepared by immersion method showed that it is possible the formation of nanoislands with uniform size and distribution by MPC. Tests in MgO and STO substrates were also accomplished based on the optimization discussed above. Tests with one layer indicated only the presence of PZT tetragonal phase. Moreover the optimized immersion conditions lead the formation of a continuous film along the MgO substrate. The sample obtained onto STO substrate presented agglomerated regions. Also hydrothermal synthesis was used to produce PZT nanoparticles. However, even with the variation of the synthesis conditions PZT powders were obtained in a micrometric scale. On the other hand, the nonaqueous route produced a low cristallinity PZT precursor, with was crystallized at lower temperatures than those reported in the literature. Besides, BaTiO3 was also studied. In this case the samples were deposited by immersion and spin-coating. The samples obtained by immersion did not present the formation of nanoislands but regions with agglomerated particles. The viscosity and concentration of organic material were investigated accomplished aiming the formation of films with the thinnest thickness possible to the samples obtained by spin-coating. The formation of continuous films was verified and in some of them the formation of pores was observed. The formation of micrometric islands was observed at higher temperatures.
Uma proposta para análise de dados com correlação espacial e temporal
(Universidade Federal de São Carlos, 2007-09-27) Pedroso, Flávia Maria de Toledo; Barreto, Maria Cecília Mendes; https://lattes.cnpq.br/2218053283392257; https://lattes.cnpq.br/8633049196791123
In several research areas, the study of the occurrence of a phenomenon over a period of time is very common. In this case, if we use the theory of Generalized Linear Models to analyze the subject of interest, we ll have, as a consequence, incorrect inferences concerning regression parameters and inefficient estimators, since considering the random variables as independent responses, is the main characteristic of this theory. When the variable response is observed over time, there can be a correlation between the observations and that must be taken into consideration on the estimation of the parameters. To incorporate this temporal dependence, we can use the theory of Generalized Estimating Equations, proposed by Liang & Zeger, 1986, as an extension of the Generalized Linear Models, to compute the correlation between the observations. Besides the temporal correlation, there can even be a space correlation and, in this case, we can use the theory of Geostatistic to estimate the reach of the correlation of samples over a study region, as well as to identify whether there is a privileged direction of variability of the studied phenomenon, important data not revealed when we utilize the theories of classic statistic. In this dissertation, we applied the methodologies mentioned above to try to explain the presence and the behavior of the female Aedes (Stegomyia) aegypti captured by adulticed traps in the city of Mirassol/SP, with the goal of helping on the search of more precise methods to contain the dissemination of dengue.
Present perfect: uma questão de aspecto : um estudo sobre o contexto na compreensão da noção de aspecto subjacente ao present perfect simples em inglês.
(Universidade Federal de São Carlos, 2007-09-27) Espino, Sabrina de Paula; Silva, Ademar da; https://lattes.cnpq.br/9028512631572133
This study approaches the present perfect simple (PP) in English, a verb structure that does not have a semantic equivalent in Brazilian Portuguese language. This fact brings out teaching and learning issues that one occasionally tries to answer. Frequently taught through out of context sentences and treated in grammar and language teaching books in a fragmented way, through confusing and haphazard explanations, this structure is difficult for Brazilian English learners to grasp. Although morphologically similar to the compound past tense in Portuguese, once both are formed by have and the past participle of a given verb, it is acknowledged that these structures do not always operate in the same way. Besides the concept of Tense, the PP also bears strong aspectual information which is rarely taken into consideration in its teaching, but essential for its understanding. With this in mind, this investigation goal was to analyze if a contextual approach facilitates the comprehension of the notion of Aspect underlying the PP. The experiment consisted of two distinct tasks, one structural and another contextual, and also a questionnaire with questions concerning some verb structures. Based on verbal protocols technique, the participants, 20 English language students attending the last year of Language College in two public universities in the state of São Paulo, were instructed to verbalize their thoughts while performing the tasks. The results are favorable to the use of contextual activities in the understanding of the aspectual feature that underlies the meaning of the PP, since this type of approach seems to attenuate the difficulties found by learners when carrying out tasks involving several verb structures, therefore providing greater possibility of focusing in aspectual features and less in temporality.
Educação religiosa, disciplina e poder na terra do ouro: a história do Seminário de Mariana, entre 1750 e 1850
(Universidade Federal de São Carlos, 2007-09-27) Selingardi, Sérgio Cristóvão; Tagliavini, João Virgílio; https://lattes.cnpq.br/8503750331108989
The seminar of Nossa Senhora da Boa Morte was founded in 1750, in the city of Mariana, headquarterrs of the first bishop of Minas Gerais, for D. Frei Manuel da Cruz , the first bishop of that diocese. This institution was responsible for the training of almost all the clergy and colonial mining man who occupied positions of proeminence in the political and intellectual fields of Brazil, during colonial and Monarchy. First, was made an apporach about the foundation of the seminar, Mariana, focusing the origins fo the Church mining and the precariousness fo instruction in the territory mining, seeking to understand taht the creation fo the aforementioned semiar justified by the preparation of young people for both European universities as for priestly career. Thus, this institution was created to satisfy the interests of elites, which did not need more send their children to study in colleges Jesuits of Bahia or Rio de Janeiro and also meet the desire of the Catholic Church, in the form of Minas a mative clergy. Then, trough the history of Seminary of Mariana, between 1750 and 1850, sought to strengthen the elitist nature of this institution, whose in majority, belonged to the most advantaged and humanistic education, whose aim was the formation of an elite leader and culture. Finally, trough the study of their Bylaws internal and his authoritarian process of education, it was found that the Seminar of Mariana it is a total institution, which possibly has positive and negative repercussions on the lives of some of his former students.