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Transferência de oxigênio e condições de cisalhamento em biorreator convencional com impelidores orelha de elefante
(Universidade Federal de São Carlos, 2013-09-30) Bustamante, Maritza Catalina Condori; Badino Júnior, Alberto Colli; https://lattes.cnpq.br/7269967957109739
Due to owing to the nature of culture involving aerobic filamentous microorganisms, conventional aerated stirred-tank bioreactors using the Rushton turbine impeller are widely employed in order to achieve good mixing and oxygen mass transfer. However, this impeller presents disadvantages such as high power consumption, and generates higher shear in the medium, which can cause irreversible morphological changes in microorganisms, damaging the culture performance. In literature, impellers called "Elephant Ear" (EE), presented in down-flow (down-pumping) (EEDP) and up-flow (up-pumping) (EEUP) configurations, are indicated as suitable for cultivation of shear sensitive cells. However, this characteristic has never been demonstrated quantitatively. In the present study, the oxygen transfer and hydrodynamics parameters were evaluated and compared in a conventional aerated stirredtank bioreactor equipped with impellers as the classical impeller Rushton turbine (RT) and with EE in EEDP and EEUP modes. Firstly, prediction equations were obtained for quantifying the average shear rate (Ýav) in the different systems, as function of the operating conditions (600≤N≤1000 rpm and 0.40≤Ýavar≤1.2 vvm) and rheological properties of the pseudoplastic fluids (K and n), based on a methodology that uses the volumetric oxygen transfer coefficient as characteristic parameter. The values of Ýav obtained from the correlations for the RT impeller were within a range of values estimated from correlations of the literature, showing that the methodology utilized is valid. Based on correlations of Ýav and on results of power consumption, the energy dissipation and Kolmogorov micro-scale (micro eddy sizes) could be estimated. For non-Newtonian fluids, the RT and EEUP impellers generated micro-eddies with smaller sizes in the range from 45.0-127.0 and 80.6-123.7 μm, respectively, showing that the impellers RT and EEUP are more shear than EEDP impeller. Using the prediction equations of Ýav the effect of shear conditions in cultures of Streptomyces clavuligerus were evaluated in conventional bioreactor equipped with RT, EEDP and EEUP impellers at 800 rpm, 0.50 vvm and 30C. Profiles of the volumetric oxygen transfer coefficient and shear rate were obtained during the cultivation. The morphological changes resulted from shear conditions imposed for the different impellers were analyzed using image analysis technique. The RT and EEDP impellers imposed the highest oxygen transfer and smaller shear to the broth, respectively. The flow pattern generated by EE impellers was crucial at the beginning of the cultivation, and is highly beneficial when EEUP impeller were used, since it presented a controlled shear throughout the cultivation. The best cultivation condition for the clavulanic acid production was obtained using the EEUP impeller, which resulted in a maximum concentration of 453 mg/L and a consistency index K= 2.5 Pa.s0.27. The results suggested that the isolated hyphae are directly related to the K of the broth and clavulanic acid production. According to the rapid fragmentation of clumps and emergence of isolated hyphae, it was concluded that the RT impeller presents shear rates higher than the EEs impellers, since the size of branched and non-branched hyphae were smaller and in greater quantities. This fact shows an advantage in the EEUP impeller use in shear sensitive microorganism cultures that requiring high levels of oxygen, without affecting the process performance. This advantage is associated with the flow pattern generated for the EEUP impeller.
Sinterização por micro-ondas em uma e em duas etapas de varistores à base de ZnO
(Universidade Federal de São Carlos, 2013-09-30) Gunnewiek, Rodolfo Foster Klein; Kiminami, Ruth Herta Goldschmidt Aliaga; https://lattes.cnpq.br/7643216999108223; https://lattes.cnpq.br/5185829124608696
This thesis is aimed at one-step microwave sintering at frequencies of 2.45 GHz and 30 GHz and the development of two-step microwave sintering (MW-TSS) at 2.45 GHz of ZnO-based nanostructured semiconductor compositions for application in varistors. The synthesis of nanostructured additives Mn, Cu, Cr, Co and Bi oxides with particles below 100 nm, based on the cationic exchange of soluble salt/polymer was developed and improved. After preparation and conformation, the samples were ultra-rapidly sintered at heating rates of 100 °C/min at 2.45 GHz and 20 °C/min at 30 GHz, both at 10 minutes of holding time, and in the two-step sintering the t2 holding time did not exceed one hour. The MW-TSS technique enabled us to reduce the pure ZnO average grain size from 4.85 (micro) to 2.85 (micro) while increasing density from 96.9% to 97.9%. For the Matsuoka nano composition, sintering at 30 GHz proved more effective, reaching a non-linear coefficient (atto) of 37 and a density of 96.5%. The addition of copper to the composition improved the value of (atto) reaching 71.4 at 2.45 GHz. However, the two-step sintering by microwave permitted a reduction in the average grain size and an increase in the electrical properties, reaching of 40 in the copper-free composition, and with the addition of copper it reached 83 with the breakdown electrical field achieving 14 kV/cm, with average grain size always below 3 μm, and, in the best condition in which the electrical properties were optimized, of merely 1.84. Although the average grain size attained is not located within the nanometric scale, sintering by microwave proved effective in obtaining varistors with excellent electrical properties, achieving finer microstructures when the two-step sintering by microwave technique is applied, with greatly reduced times for both one-step and two-step sintering techniques. The accelerated diffusional processes relative to the possible nonthermal effects caused by the microwave processing were also discussed.
O mal-estar em Guimarães Rosa - os empecilhos da cultura encenados nas famílias rosianas: a tragicidade da constituição cultural
(Universidade Federal de São Carlos, 2013-09-30) Cardoso, Naiara Mangino; Alves-Bezerra, Wilson; https://lattes.cnpq.br/1602719736498812; https://lattes.cnpq.br/3951720136978245
En este trabajo proponemos analizar tres cuentos de João Guimarães Rosa Sorôco, sua mãe, sua filha (1962), A terceira margem do rio (1962) y Meu tio o Iauaretê (1969) por medio de la teoría psicoanalítica. Las dos nociones principales que estructuraran nuestra lectura son: la cultura (Kultur), a partir de los estudios de Sigmund Freud (1930), y el significante, a través de los apuntes de Jacques Lacan (1957). Teniendo por base tales nociones pretendemos demostrar cómo en Rosa se arquitecta estéticamente la tragicidad de la constitución cultural (cf. Walnice Nogueira Galvão, 1978). La cultura (Kultur), establecida a partir de los tabúes que limitan la realización de los deseos humanos, causa malestar (Unbehagen). De este modo, el hombre crea una relación problemática con este universo lleno de privaciones fundamentadas en la Ley. Tal problemática es puesta en escena en estos tres cuentos rosianos de distintas maneras. Somos así, colocados delante del sentimiento de culpa oriundo de la instauración cultural (Freud, 1912-1913) , de la locura, y de la ilusión (Illusion) (cf. Freud, 1927) de un posible regreso a la Naturaleza tiempo mítico y místico de la plenitud del sujeto. Todo se pasa en el microcosmo de las relaciones familiares (padre e hijo en las márgenes del río, Sorôco, su madre y su hija, y el sobrino de Iauaretê), que se confrontan con las relaciones de parentesco (cf. Lévi-Strauss, 1949); o sea, prenderse en la familia perjudica la unión en la cultura (Kultur), que tiene por objetivo la supremacía de los lazos artificiales sociales en detrimento de las relaciones naturales (cf. Lévi-Strauss, 1949) familiares.
A experiência da estereoscopia no audiovisual contemporâneo (2005-2012)
(Universidade Federal de São Carlos, 2013-09-30) Cordebello, Pedro Dolosic; Massarolo, João Carlos; https://lattes.cnpq.br/3308336910966465; https://lattes.cnpq.br/7962735326969600
Stereoscopic three dimensional pictures has gained significant importance in the entertainment industry nowadays. 3-D movies are intended to bring back the audience to the theater, and the stereoscopic television is the technology which will bring such immersive experience in the home. However, to produce, transport and show high quality stereoscopic content many skills and technologies are involved. The aim of this work is to bring some of the newest technological achievements in this area to anyone interested, and to contribute to scientific production in this research field.
Desenvolvimento de sistemas automáticos empregando flow-batch e multicomutação para análise fotométrica de amostras de interesse farmacêutico e agronômico
(Universidade Federal de São Carlos, 2013-09-30) Pereira, Alessandra Félix da Costa; Reis, Boaventura Freire dos; https://lattes.cnpq.br/7619359855870896; https://lattes.cnpq.br/3911505765005171
In this work is proposed the development of automated procedures with sufficient sensitivity for photometric determination of aluminium in water used for hemodialysis treatment and nickel in digested plants. ANVISA established that the maximum allowable concentration is 10 μg L-1 Al (III) in solution for hemodialysis. The matrix has a high concentration of salts such as Ca, Mg, K and about 30% (w/v) NaCl, thus causing difficult to determine the metal. This drawback was overcome in this work by employing a multicommuted flow-batch system and a LED photometer equipped with a flow cell with optical path length of 200 mm. There was no prior preparation of the sample and the method was based on the reaction of Al (III) with chromeazurol S, producing a compound of pink color, which absorbed electromagnetic radiation with maximum at 530 nm. After optimization of the parameters, the proposed procedure showed a linear response range between 5.0 and 125 μg L-1; a detection limit of 0.6 μg L-1; consumption of 12 mg and 85 mg S chromeazurol and hexamine per determination, respectively; a sampling frequency of 70 determination per hour and a waste generation of 1.6 mL per determination. To evaluate the accuracy of the methodology was employed standard addition and the results showed a recovery in the range 90-113 %. The analytical module for the determination of nickel was developed to implement the multicommutation process with the use of solenoid minipump as fluid propelling device. The procedure was developed based on the reaction with Ni (II) with dimethylglyoxime in alkaline medium, producing a compound which showed maximum absorption at 490 nm. After optimization of the control parameters, the proposed procedure showed a linear response in the range from 0.13 to 2.0 mg L-1; detection limit of 0.04 mg L-1; 2.40 mg consumption of trietanolamine; 2.00 mg of potassium persulfate; and 0.40 mg of dimethylglyoxime, all for determination.
Desenvolvimento de três aplicativos educacionais para plataformas de tablets e smartphones baseados em sistemas iOS
(Universidade Federal de São Carlos, 2013-09-30) Varjão, Ricardo Moreira; Garcia, Ducinei; https://lattes.cnpq.br/5236758856687873; https://lattes.cnpq.br/5329334049890115
This study aimed to produce educational apps for tablets and smartphones targeted to teaching physics and mathematics that could be used both in the classroom and in informal places of learning and teaching. "Kinematics", "String" and "Equation" with themes of kinematic waves on strings and polynomial equations up to the third degree, respectively, three applications for iOS systems were developed. Until the release date at the Apple Store, between December 2011 and January 2012 up to September 2013 were made more than fourteen thousand downloads in one hundred and twelve countries spread across all continents. Comments sent to the author, both the virtual store, and through social networks, demonstrated the successful implementation of these new applications as educational tools.
Abordagem do ensino de desvio padrão em livros didáticos
(Universidade Federal de São Carlos, 2013-09-30) Francisco, Sérgio Luiz; Moura, Renato José de; https://lattes.cnpq.br/5227908949297904; https://lattes.cnpq.br/7962308898758608
Teaching Statistics as part of the axis Treatment Information is seen by PCN (Parâmetros Curriculares Nacionais) as a tool for the interpretation of the world that surrounds the pupil, in view of the diversity of areas using the typical elements of Statistics (such as tables, graphs, etc.) in the dissemination of information. Hence, the need for teaching this subject should strive for contextualization of its contents and provide information for decision-making. The objective of this work was to present a didactic sequence that judges be more appropriate as the significance for the student with regard to the teaching of some of these elements of statistics, specifically the Standard Deviation, the application of an exercise in a class of 3rd. year of high school public school education in the city of Jahu. Together, adds that, after analysis of seven textbooks indicated by PNLEM programs (Programa Nacional do Livro Didático do Ensino Médio) and PNLD ((Programa Nacional do Livro Didático) as to approach the teaching of statistics, it was found that in one there is the option for this instructional sequence in which the settings of the approach is associated with the Normal Curve probabilities related to a frequency distribution. Expected to lead teachers and mentors to reflect on the teaching of this subject, both in performance in the classroom or guidance for professionals in education, as in the choice of books or other educational materials.
Modelagem da eficiência de coleta em ciclones utilizando a fluidodinâmica computacional
(Universidade Federal de São Carlos, 2013-09-30) Ramirez, Maribel Valverde; Gonçalves, José Antônio Silveira; https://lattes.cnpq.br/0337997526924402; https://lattes.cnpq.br/9371597807489520
Cyclones are used to separate suspended particles from gas streams. The analysis of flow inside the cyclone is complex due to the large number of parameters and operating variables that influence the dynamics of the system. Due to its versatility of use and its robustness, results in computational fluid dynamic are an important alternative often used to study the dynamics of flow in the cyclone. In the literature, several works make use of computational fluid dynamics in order to study the pressure drop of cyclones. However, the works about the efficiency of collection are fewer. For the cyclone, computational fluid dynamics allows an accurately simulation of the collection efficiency of particles with diameter greater than 5 µm; but for particles with smaller diameters the simulated results diverge from experimental values. In this work, Stairmand s cyclone was numerically simulated with injected particles with diameters from 1 to 5 µm. The results were verified using available experimental data reported in the literature. The experimental data taken from literature belong to Zhao and Shen Kang (2004) and Zhao (2005). The simulation mesh was analyzed before and after the simulations. The turbulence models used in the simulation of flow in the cyclone were: Reynolds Stress Model (RSM) and Large Eddy Simulation (LES). The dispersed phase was simulated considering one and two way couplings. The equation of motion of the particles was integrated using the integration schemes: implicit, analytic, trapezoidal, and Runge-Kutta. The results showed that the methodology was adequate to reproduce the behavior of the flow in the cyclone. The error percentages obtained in pressure drop were under 5% and the average collection efficiency was reproduced with good accuracy for diameters of 3, 4 and 5 µm.