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Influência da incorporação de poli(ácido lático) - PLA, de pó de madeira e outros aditivos no comportamento físico-mecânico do poli(hidroxibutirato) - PHB
(Universidade Federal de São Carlos, 2004-04-30) Falcone, Daniele Maria Bruno; Agnelli, José Augusto Marcondes; https://lattes.cnpq.br/7592090152400440; https://lattes.cnpq.br/8438856690765294
Polymeric materials are used today in the most varied sectors and the deleterious effects of their application, particularly in the short-term, have led to increasing environmental concern. On the other hand, innovative biodegradable polymers, which promise to offset these effects, are still hampered by their high cost and often unsatisfactory performance. In view of this fact, a study was made of poly(hydroxybutyrate)/poly(lactic acid) - PHB/PLA; poly(hydroxybutyrate)/wood powder-PHB/WP; and PHB/other modifiers (starch, rice chaff, sugarcane bagasse fiber) blends and compounds. These blends and compounds were evaluated and characterized using the following techniques: Melt Flow Index (MFI), Capillary Rheometry, Torque Rheometry, Differential Scanning Calorimetry (DSC), Thermogravimetry (TG), Dynamic Mechanical Thermal Analysis (DMTA), Physical and Mechanical Tensile and Impact tests, Heat Deflection Temperature (HDT) tests, and Scanning Electron Microscopy (SEM). The results obtained indicated the immiscibility of the PHB/PLA blends. The absence of transesterification reactions in the PHB/PLA blends was verified by TG. From the standpoint of mechanical properties, the PHB/PLA blends generally displayed characteristics superior to those of pure polymers. On the other hand, the polymeric compounds containing wood powder displayed rigidity and greater brittleness due to the lack of adhesion between the wood powder and the polymer, as indicated by SEM. This study therefore indicated that it is possible to obtain materials with adequate physical and mechanical characteristics that are viable particularly for short-term applications.
O início da docência e a trajetória profissional segundo a visão de professoras em final de carreira.
(Universidade Federal de São Carlos, 2004-04-30) Pizzo, Silvia Vilhena; Lima, Emília Freitas de
The present work called The Beginning of Teaching Profession according to Ending Career Professors , has the aim to investigate the following inquiring question: What are the aspects that Elementary School first to fourth grade teachers at the end of their career remember from their initial professional course process of becoming a teacher? The theoretical reference used has involved studies about the construction of teacher career beginning, the professorship professional development, and learning by experience. The initial phase of the career is extremely important because it is the moment that the teaching bases are constructed. At this phase have occurred rare instants in teachers life becoming unique and transitory for them. It is a stage marked by the professor s attempts and mistakes, when the feelings of survival and discovery have appeared. The professional development of teachership involves personal growth dimensions, professionalism, and socialization. The teaching learning by experiences valorizes the practice in the classroom, and the experiences that are fundamental to the process of being teachers. In order to accomplish this research we counted with the participation of six educators that work in Public State Schools at least twenty-one years, that is considered the end of the career. The data were collected from semi-structured interviews made with teachers, and literally transcribed later. After these the statements were grouped for analysis according its similarities and discrepancies. The results obtained in this research indicate that: the beginning of the career is really, like shown in the literature, a difficult moment, with a lot of newness, conflicts, expectatives, rare episodes, and sometimes, the reality shock . The career maturity is related to the life experiences and personal route of each teacher, and the data have shown that the educators valorize the professional learning by experience as fundamental to the process of becoming professors. The reflection is seen like an important link between the acquired theories in the initial professional formation and the classroom practice.
Dinâmica da alimentação de peixes piscívoros da Represa de Três Marias (MG)
(Universidade Federal de São Carlos, 2004-04-30) Peret, André Moldenhauer; Verani, José Roberto; https://lattes.cnpq.br/0053232138684810; https://lattes.cnpq.br/6651955939013556
The fish feeding study is a valuable tool on understanding the interactions between populations in a community. The Três Marias reservoir, on the high region of the São Francisco River (MG), is a typically oligotrophic environment with a high density of piscivorous fishes (about 20% of the total icthyomass). To support this trophic guild on environments like this, it is expected a high aloctone matter input. In such environment, in the high waters period, the marginal area is flooded, providing food to the fodder species, which support the piscívorous communities. During this period, the contribution of terrestrial insects is fundamental to support many fish species. It was analyzed the stomach content of five piscívorous species (Serrasalmus brandti, Pygocentrus piraya, Pachyurus squamipennis, Acestrorhynchus britskii and Acestrorhynchus lacustris) in four distinct periods of the year and four stations in the reservoir. The food items importance was estimated using the feeding index. S brandti was the only piscívorous species responsible for the incorporation of aloctone matter, basically terrestrial insects. The other species showed a high niche overlap during the high waters period (higher food providing), when they feed basically upon Anchoviella vaillanti, and had a wide niche overlap reduction in the low waters period, what characterizes a niche displacement. It was detected, on the station that receives domestic waste, a reduction on the niche overlap, an indication of a change on the food offer, as a consequence of the environmental pollution or even of the enrichment by the additional organic matter input.
Engenharia de interações fônon-fóton-matéria mediadas por um campo clássico
(Universidade Federal de São Carlos, 2004-04-30) Rodrigues, Ricardo Luciano; Moussa, Miled Hassan Youssef; https://lattes.cnpq.br/7828776012924524; https://lattes.cnpq.br/3539989706481901
In this work we consider the problem of a three-level trapped ion inside a high- Q cavity. We study the process of phonon-foton-matter interaction mediated by a classical field. We are particularly interested in the engineering process of two excitation changes, phonons and/or photons, which result in squeezing of the cavity mode and/or the vibrational field. The adiabatic aproximation is employed to obtain simplified effective Hamiltonians.
Respostas fisiológicas ao estresse em Prochilodus scrofa durante a exposição ao cobre e subseqüente recuperação em água sem cobre
(Universidade Federal de São Carlos, 2004-04-30) Pinheiro, Guilherme Henrique Dyonísio; Fernandes, Marisa Narciso; https://lattes.cnpq.br/3021357484136942; https://lattes.cnpq.br/4219585514139735
Copper is an essential trace-element for all live organisms however, when its concentration is high in the aquatic environment, copper is potentially toxic. Most physiological changes caused by copper in fish has been analyzed after acute exposure (96h). The aim of this study was investigate the physiological responses of Prochilodus scrofa to stress, during acute copper exposition (24, 48, 72 and 96 hours) and recovery period after animal transference to clean water, and the time necessary to recovery after animals transference to clean water. The changes associated to fish transference to experimental systems were also evaluated. Juveniles Prochilodus scrofa were acclimated during 30 days and then fish were sampled to take blood for pH, hematocrit, plasma cortisol glucose and ions (Na+, Cl- e K+) analyses and specific Na+/K+-ATPase activity of gills. The remaining fish were divided in two groups: control (C) and exposed to copper (CU) and transferred to glass aquariums where was kept for 4 days. CU groups were exposed to copper (96h-CL50 = 29 µgCu L-1). Sampling was done 1, 2, 3 and 4 days of copper exposure. Surviving fish were then transferred to aquariums with flowing water without copper and sampling was done 1, 2, 7, 15 and 30 days of recovery. Blood sampling was taken for the same analyses above cited. Plasma cortisol concentration increased 300 a 400% in control and copper exposed groups related to acclimated fish, plasma glucose increased 800% only in the copper exposed groups during the exposure period and returned to normal levels in the 2nd day of recovery. In general, the changes in plasma ion (Na+, Cl- e K+) concentrations and pH were not significant in relation to those of acclimated fish however, significant changes were found between the values of control and copper exposed groups during copper exposure and recovery period. The activity of Na+/K+-ATPase of gills was lower in the CU group during the copper exposure period and on the 1st day of recovery. The hematocrit increased during metal exposure but on the 1st day of recovery reached the normal values. Although changes were found on the analyzed parameters, on the 7th days after the transference to clean water all parameters evidenced a tendency to recovery the physiological changes reaching the values of acclimated fish. The present study showed that the stress responses to copper exposure is complex and P. scrofa presents high susceptibility to handling evidencing the importance of comparative analyses involving acclimated and/or unstressed fish together with the controls and exposed fish to a given stressor.
Representações de professores: elementos para refletir sobre a função da instituição escolar e da professora de educação infantil
(Universidade Federal de São Carlos, 2004-04-30) Assis, Muriane Sirlene Silva de; Basso, Itacy Salgado; https://lattes.cnpq.br/3283708100330653
Contribuição para o conhecimento do gênero Chironomus Meigen, 1803 na região neotropical
(Universidade Federal de São Carlos, 2004-04-30) Correia, Leny Célia da Silva; Strixino, Susana Trivinho; https://lattes.cnpq.br/1804083229761186
The present work aimed to study one of the most used genera in water quality assessment, Chironomus, identifying and/or describing the species inhabiting aquatic systems of the State of São Paulo with varied ecological features. The study area included 27 aquatic systems consisting of lentic habitats (lakes, reservoirs, temporary pools, waste stabilization lagoons and fish ponds) and lotic habitats (streams, rivers and drainage channels) at different localities of Mogi-Guaçu and Tietê-Jacaré hydrographic sub-basins. The sampling and analyses followed the conventional methods used in taxonomic and limnological studies. The survey resulted in the identification of 16 Chironomus species, including 7 new records to the State of São Paulo and 8 new species. Besides C. sancticaroli Strixino & Strixino, 1981, a species previously recorded in the State of São Paulo, I identified the immatures and adults of C. calligraphus Goeldi, 1905, C. gigas Reiss, 1974, C. latistylus Reiss, 1974, C. paragigas Reiss, 1974, C. strenzkei Fittkau, 1968, C. stigmaterus Say, 1823 and C. columbiensis Wülker et al., 1989. Some species were sampled in similar habitats, indicating a possible relation with them. C. gigas, C. paragigas and C. latistylus were collected only in lentic systems with low antropic influence. The immatures of C. sp. 1, C. sp. 5 and C. sp. 6 were sampled only in association with aquatic macrophytes growing in lakes and stream pools. C. sp. 3 and C. sp. 4 inhabited temporary pools with great amounts of detritus. C. stigmaterus and C. calligraphus were found only in waste stabilization lagoons. Only the larvae of C. sp. 2 were sampled in lotic systems polluted with high level of organic material from urban sewage and agricultural activities. The morphological analyses of larvae enabled the construction of a preliminary identification key for the species of Chironomus that live in the different aquatic systems of the State of São Paulo. This key could be a useful tool in analyses and diagnostics carried out during water quality assessment programs.