Browsing by Issue Date, starting with "2013-03-19"

Filter results by year or month

Now showing 1 - 20 of 18154

Análise da secagem convectiva de folhas de manjericão (Ocimum basilicum L.)
(Universidade Federal de São Carlos, 2013-03-19)
Lima, Renata de Aquino Brito
;
Ferreira, Maria do Carmo
;
https://lattes.cnpq.br/7070885875161111
;
https://lattes.cnpq.br/5050641829811424
Convective drying of leaves involves heat and mass transfer in packed-beds of deformable material, since the leaves shrink significantly when the moisture is removed. Therefore, the packing structure changes over time, and the transfer properties alter as well. An additional drawback is the challenge to obtain reproducible packings, given the random nature of packing for such an irregular type of material. In this work, an experimental investigation was conducted to analyze how basil leaves (Ocimum basilicum L.) behave during drying focusing in the challenging characteristics of this particulate phase. A full characterization of the leaves as a particulate solid was conducted by measuring their dimensions, specific density, initial moisture content and equilibrium moisture content. Loose and compacted bulk densities were measured for beds of leaves under different moisture content. Results indicate that the basil leaves have a low sphericity (=0.160), a high projected area (Aproj=4.55 cm2) and density equal to 0.874 g.cm-3. Bulk density of fresh leaves was 0.089 g.cm-3 in loosely packed-beds, and 0.198 g.cm-3 in compacted packed-beds. Drying experiments were performed in a range of 30 to 60oC under different air-particle contact modes, including fixed and moving beds. Drying cells 10 cm in diameter with heights of either 1 or 12 cm (corresponding to thin-layer and deep-layer beds respectively) were tested with air flowing perpendicular to the samples. In moving beds, a rectangular chamber of dimensions 20 cm x 11 cm was used, also with air flowing perpendicular to the samples. In the conditions tested, problems were observed regarding reproducibility of data of moisture content versus time, bed shrinking, channeling and non-homogeneous drying. It was demonstrated that these problems appear due to the inherent characteristics of the leaves (low density, high ratios of surface area to volume, rough surface, etc.), and also due to their biological variability, which made it difficult to obtain packed-beds with reproducible characteristics in different assays. Homogeneous drying was obtained only for moving beds with vertical vibration, under dimensionless vibration parameter equal to 1.0 and an amplitude of vibration of 0.5 cm. The effect of the cell diameter to mean leaf size ratio (D/dm) on the bulk densities and drying rates was also investigated. For that, the size of leaves was reduced by cutting them in two parts widthways (half-sized particles), and also in four parts, width- and lengthways (quarter-sized particles), resulting in D/dm= 4.2 (whole leaves), 5.3 and 7.8 (half- and quarter-sized leaves respectively). It was observed that loose and compacted bulk densities did not vary significantly for beds of half-sized particles, but increased approximately 20% in beds of quarter-sized leaves. Regarding the drying rates, a tendency of an increase as D/dm was raised to 7.8 was observed, but the variation remained within the range of standard deviation of experimental data. Axial shrinking of the beds throughout drying was measured in deep packed-beds. The initial bed height was reduced by approximately 47% after 100 minutes of drying at 60 oC. The pressure drop through the bed decreased drastically when the leaves were dried, resulting in an increase by 141 times in the bed permeability for drying at a temperature of 60°C. The results obtained show that the packed-bed structure strongly affects the heat and mass transfer during convective drying of leaves.
Abordagem ativa da acústica no ensino médio com a confecção de artefatos musicais pelos alunos
(Universidade Federal de São Carlos, 2013-03-19)
Pereira, Rodrigo Machado
;
Leodoro, Marcos Pires
;
https://lattes.cnpq.br/2929842229198829
;
https://lattes.cnpq.br/1138096178145802
This paper aims to present, as experience report, an active approach to teaching about the content of Acoustics by contextualized knowledge of music, from the design and construction of sound artifacts with low cost materials for high school students. The activities were conducted in a public school of the state of São Paulo in the city of Mogi Guaçu. The acoustic content were worked both quantitatively and qualitatively. Qualitative analysis was applied to the study of the properties of sound musical artifacts produced by students taking into account the aspects of production, propagation and amplification of sound. The quantitative phase of didactic activity was conducted using the software "Soundcard Scope V1.4" which allowed the harmonic analysis of the sound produced by these devices and captured by the sound card of a computer. The active approach we present has its theoretical foundations in education and social constructivist approach is inspired by Kuhn's epistemology. Process is guided by social contextualization of knowledge and consideration, the teacher, the students' spontaneous conceptions, as well as the cooperative work between them. The mediation of the teacher tried to always be located within the Zone of Proximal Development (ZPD) of the students and thus contributing to the formalization of scientific concepts worked. We have also added strategies such as the use of Information and Communication Technologies (ICT) and the approach of the relations between Science, Culture and Society. The material production of students through the sound artifacts that confected, and the monitoring of the production process of these signs indicate that the work has motivated students for learning physics, and also contributed to make it meaningful to them, some concepts of acoustics.
Desenvolvimento da microscopia de força química usando modelagem molecular
(Universidade Federal de São Carlos, 2013-03-19)
Amarante, Adriano Moraes
;
Leite, Fabio de Lima
;
https://lattes.cnpq.br/5490031389817518
;
https://lattes.cnpq.br/5625045786963147
;
Campos, Sérgio Dias
In this work was developed a prototype of a new nanobiosensor with molecular specificity through a study of theoretical models of Chemical Force Microscope. For the sensing were used molecular modeling techniques as well as experimental models of the functionalized Atomic Force Microscope tip with the Acetil co-A Carboxylase (ACC) attached. Specific and non-specific inhibitors were used to evaluate substrate-enzyme interactions. The nanobiosensor investigates specific enzymatic inhibition characteristics of the ACC enzyme through the herbicide Diclofop by reversing this process applying a force in a determined direction. The force is theoretically calculated by using molecular dynamic techniques associated to the adhesion force experimentally obtained. Theoretical and experimental questions involving nanobiosensors of AFM tips still obscure until now, such as, the number of functional enzymes attached on the AFM tip, the number of the active sites available to interact after immobilization process, the consequences of the enzyme immobilization as well as the substrate and theoretical adhesion between AFM tip and substrate were analyzed here.
Contribuições para a otimização da programação da produção de bebidas a base de frutas
(Universidade Federal de São Carlos, 2013-03-19)
Pagliarussi, Marina Sanches
;
Morabito Neto, Reinaldo
;
https://lattes.cnpq.br/6595717122698262
Beverage factories have been trying to improve production planning and control to increase competitive advantages and market shares. In order to achieve such goals, the industries attempted to improve the process of meeting demands, manufacture larger product variety in less time, use less resources and considering the factory´s operating limit. This work considers a production planning problem which lies in the factories which manufactures non-alcoholic beverages fruit. The research problem is the lotscheduling of drinks, characterized by: finite planning horizon, multi-period, multimachine, capacity constraints, setup time and cost, special machine constraints (the machines must be cleaned after certain production time). An optimization approach based on mathematical modeling is proposed, considering different scenarios and using optimization softwares. The proposed models are variations of mixed-integer programming models well-known in the literature, such as the GLSPPL (General Lot Sizing and Scheduling Problem for Parallel Production Lines) and CLSP (Capacitated lot sizing problem). However, instead of considering parallel machines, different arrangements of machines are considered to obtain better representation of the production processes. In order to validate the models, we proposed an approach involving a case study in a beverage factory in the state of São Paulo. The solutions obtained by the models were compared with those used in practice. The results show that the proposed approach has good potential for practical use.
Aplicação do resíduo de bauxita como fonte de Al2O3 e Fe2O3 na preparação de clínqueres de cimentos portland
(Universidade Federal de São Carlos, 2013-03-19)
Lourenço, Rafaela Roberta
;
Rodrigues, José de Anchieta
;
https://lattes.cnpq.br/4000441989868775
;
https://lattes.cnpq.br/9480551360978454
During the past decades, the bauxite residue (BR) generated in the aluminium production was considered unusable waste. However, the difficulties and the costs associated with the residue management and storage have motivated companies to invest in innovative research to find economical and environmentally safe applications for the BRin order to reduce the volume of waste stored. In this context, the building industry offers a promising application for BR. This sort of residue could be used in large quantities in the production of Portland cement, one of the most important materials in this sector. The partnership between the aluminium and cement producers might benefit both areas, opening a great opportunity to move towards sustainable development and to minimize environmental impacts. Therefore, the aim of this study was to evaluate the use of BR as an alternative source of Al2O3 and Fe2O3 in Portland cements clinker. Four formulations were developed: one without BR, which was used as a reference composition (C1),and three others containing 3wt%(C2)7 wt%(C3) and13 wt% (C4) of BR. As the main phases-C3S, C2S, C3A e C4AF- were detected in the produced clinker, it was clear that BR addition did not affect the mineralogical composition. Nevertheless, BR contents equal or greater than7wt% resulted in the formation of C3A doped with Na, which has an orthorhombic structure. Based on the quantitative X ray diffraction results and on the phase s morphology it was found that although the presence of residue has altered the chemical composition of the clinker, the mechanical behavior of the material was not affected. The mortars prepared with these clinkers reached satisfactory compressive strength and C4 materials had values of 39MPa. The results demonstrated that the presence of the BR did not affect negatively the quality of the produced material which indicates an interesting potential application for the BR.
Discriminações condicionais em bebês de risco: o responder por exclusão
(Universidade Federal de São Carlos, 2013-03-20)
Sertori, Natália Maria
;
Gil, Maria Stella Coutinho de Alcântara
;
https://lattes.cnpq.br/1673770301699940
;
https://lattes.cnpq.br/4989052052680767
Exclusion responding has been investigated as the immediate choice for unknown comparison stimuli (picture or object) facing a model stimulus also unknown. For Behavior Analysis, it is one of the processes by which children learn to relate new words to new objects or new events. This process has been extensively investigated under experimental conditions and is usually based on studies made by the teaching of "conditional discrimination" with the technique of matching to sample. Considering the advances in literature, the present study aimed to investigate exclusion responding in infants aged between 13 and 20 months, with indicators of difficulties in language acquisition. Data collection began by teaching familiar conditional relations in base lines, using familiar stimuli. After the establishment of such relations, tests of exclusion, control and learning with familiar insertion using objects intercalated between the base lines were conducted. The results demonstrated the repeatability of the procedure, seen in previous studies, through which the population of young children respond by exclusion and some show, after being exposed to more than one attempt, they learn to relate word-object. Control probes showed that all babies responded under control of the topography of selection and rejection in different attempts. Two participants demonstrated control only by selection in all attempts. The procedure was terminated either if the baby hit the learning probe or after a maximum of two sessions with five attempts. One can assume that this study brings an important variable - the investigation of the control of responding by exclusion, with babies from this age group - using the "teaching notebook" as storage apparatus, in hopes to bring about a more natural environment for the child, in order to not to cause "strangeness" to the little ones, besides all methodological difficulties that audience brings. In the present study, emphasis was given to the teaching procedures of exclusion responding to babies at developmental risk, younger than populations previously studied, in order that studies with small children in the language acquisition phase can contribute to the proposition of further studies for the improvement of language teaching procedures.
A gestão entra em cena: um estudo do programa gestão nota 10 do Instituto Ayrton Senna
(Universidade Federal de São Carlos, 2013-03-20)
Stabelini, Ana Maria
;
Riscal, Sandra Aparecida
;
https://lattes.cnpq.br/8644271456768354
This study aims to identify and analyse the theoretical and methodological foundations in which underlie the Programa Gestão Nota 10, from Ayrton Senna Institute, which aims to implement a management methodology in public schools. The study was conducted through analysis of category of management, partnership and social justice that support the discourse presented by the Institute in its disclosure documents and course material, focused on managers of public networks in the municipalities which are partners of the program .We also analysed some action strategies proposed in partnership with two local systems of education - the cities of São Roque Guariba - in the state of São Paulo. The findings show that the program presents management concepts, partnership and social justice, removed from the productive sphere. The results management is considered by the Office as the most appropriate form of management for the school to be more efficient and effective and should be adopted by all public education. On the other hand partnership policy seems to work as a supply of services of the Institute, which would help in solving the problems faced by municipalities. In relation to the issue of social justice, they believe that equality of opportunity is the possibility of being able to enter in the labor market. Furthermore, there is a use of range of terms that, despite they are similar, they take on different meanings. We also note that the implementation of results management is encouraged not only in educational administration, but on the whole educational process by encouraging students to be managers of their learning process.
Tecnologia naval e política: o caso da marinha brasileira na era dos contratorpedeiros, 1942-1970
(Universidade Federal de São Carlos, 2013-03-20)
Waldmann Júnior, Ludolf
;
Martins Filho, João Roberto
;
https://lattes.cnpq.br/5064104684523336
This work aims to analyze the technological modernization of the Brazilian Navy in the period between 1942 and 1970. Despite starting the Second World War without conditions of defending the country, the Brazilian Navy has modernized with American support, equipping it with modern anti-submarine equipment within the concept of hemispheric defense. At the end of the conflict and start of the Cold War, U.S. politics for the Latin America changed, and the Brazilian Navy stopped receiving modern military equipment from that country. Nevertheless, most Brazilian officers continued supporting the principles of the hemispheric defense, which mean subordination, strategic and intellectual, to the U.S. Navy. For much of the following decades, despite the changes in the foreign policy and investments in scientific and technological research in Brazil, the Brazilian Navy continued subordinated to the concept of hemispheric defense, with an obsolete fleet and unable to get modern ships. In late 1960s, the Brazilian Navy begins to face difficulties in acquiring modern weapons because of changes in the U.S. politics, culminating in the acquisition of British frigates, which despite having great emphasis on anti-submarine warfare, mark the recovery of shipbuilding in Brazil, the beginning of the withdrawal of the material and intellectual dependence on the U.S. and a major technological leap in the Brazilian Navy.
Biodiversidade como tema para a educação ambiental : contextos urbanos, sentidos atribuídos e possibilidades na perspectiva de uma educação ambiental crítica
(Universidade Federal de São Carlos, 2013-03-20)
Thiemann, Flávia Torreão Corrêa da Silva
;
Oliveira, Haydée Torres de
;
https://lattes.cnpq.br/5458113597909705
;
https://lattes.cnpq.br/4159638058064663
Biodiversity is all around us, in what we wear, eat, into objects from our daily, past and future lives. It is present as an explosion of colors and hues, sounds and smells. It is both invisible and inescapable. The discourses on biodiversity are also multiple: it is the basis of life on Earth, it is essential, and yet suffers constant threats. In this thesis we seek to raise possibilities of working with biodiversity as a theme in an urban environment, the São Carlos Ecological Pole, and to understand the meanings attributed to biodiversity by researchers and students in the Life Sciences and similar areas, and to envision possibilities for addressing the concept of biodiversity in environmental education processes conducted within the principles of a critical environmental education. We conducted a qualitative study, using naturalist research techniques and the Delphi Method, and used a philosophical hermeneutics perspective to interpret and understand the data. This research generated nine categories of meaning attributed to biodiversity: Concreteness, Symbolic, Knowledge, Holism, Kaleidoscope, Hidden, Threatened, Inclusive and Exclusive, listed 16 sets of concepts considered essential, organized in spheres that contemplate aspects of scientific content, values and action, and six suggestions of themes that can help the process of learning about biodiversity: Experiencing biodiversity; "Opening your eyes" for biodiversity; Exercising dialogue/discussions; Acknowledging the importance of biodiversity and the limits of human interference; Biodiversity in our own territory; Overcoming teaching fragmentation. The results are ideas, suggestions, possibilities to be explored from the perspective of a critical environmental education, and must be contextualized in processes that respect the multiplicity of views on environmental issues, and seek understanding and to build agreements that allow for action in favor of the diversity of life on Earth.
Método Halliwick de natação: aplicação em crianças com deficiência visual
(Universidade Federal de São Carlos, 2013-03-20)
Gomide Neto, Ulysses
;
Denari, Fátima Elisabeth
;
https://lattes.cnpq.br/5575213011914394
;
https://lattes.cnpq.br/2905797623719852
Swimming is one of the most complete sports and more accessible to all kinds of people. The benefits of swimming for visually impaired relate to social, cognitive, motor and affective. Development is a continuous process that starts from pre-natal to death of the person. This research aimed to examine the program and apply the ten points of the method Halliwick swimming in children with Visual Impairment, highlighting the benefits brought by this reality, the dimensions cognitive, affective and motor skills of the children in the aquatic environment. The water allows people perform amazing moves that were made in the soil would be more difficult and performed by few, water also provides people with disabilities numerous benefits such as: rehabilitation and stimulation of paralyzed muscles, strengthening the muscles that helps in posture, relief of pain, strength work without worrying about friction, perceptual-motor intervention, independent mobility, among others. This, the methodological procedures were applied to children aged seven to thirteen years old. The results achieved with the research showed an improvement in motor coordination, sensory spatial orientation and understanding and ease of use of the proposed methodology employed and thus it is concluded that it can become more of a learning aid for swimming children with Visual Impairment. It is hoped that this research emphasize the potential of people with Visual Impairment, disclose the method Halliwick swimming and encourage their practice with people with disabilities
A escola e o bairro entre o público e o privado: um estudo da concepção do Programa de Gestão Comunitária da Associação Cidade Escola Aprendiz
(Universidade Federal de São Carlos, 2013-03-20)
Freitas, Mayara de
;
Riscal, Sandra Aparecida
;
https://lattes.cnpq.br/0325728474204996
This study has enquired the Bairro-Escola conception, a social program from the ONG Associação Cidade Escola Aprendiz. Terms such as Bairro-Escola , Educador Comunitário , and Gestor Público em Educação Comunitária have had their meanings analyzed according to community, partnership, and social justice ideas. The data on Bairro-Escola were collected from its documentation in websites, manuals, projects, etc. From this data, the Bairro-Escola s purposes have been compared to the theoretical concepts which one alleges to guide this program. One seeks to know how the Associação Cidade Escola Aprendiz s policy is conducted by compensatory actions which are part of modernization, rationalization, and result management projects that they have been developed in the brazilian education policy. That research has in Max Weber, John Rawls, Maurício Tragtenberg, and Evelina Dagnino s studies their theoretical support. In those studies, concepts as work, progress, modernization, rationalization (Weber), fairness, social justice (Rawls), management, self-management, ideology, administration (Tragtenberg), perverse confluence, participation, and citizenship (Dagnino) are discussed. In this study, we found some concepts about education within the Bairro-Escola project from the Associação Cidade Escola Aprendiz. Communitarian education features are like the perverse confluence, that look for improving the human and social capital by development of their abilities. This development has a constitutive ambiguity between the mercantile interests in maximizing profits and the public image based on "social responsibility."
Experimentos probabilísticos: noções de probabilidade no ensino fundamental II
(Universidade Federal de São Carlos, 2013-03-20)
Biajoti, Emerson Donizeti
;
Paterlini, Roberto Ribeiro
;
https://lattes.cnpq.br/6240750958932738
;
https://lattes.cnpq.br/4975815157723039
This work has as its main goal to show the results of an instructive and pedagogical research which uses games with coins and dice, whose solutions and appropriate teacher´s mediation, allow the student to make the construction about the initial concepts of Probability. This research, through the engineering instructive method, took place in four different 7th grade classrooms in a public school, in the countryside of the state of São Paulo. The results show that the use of such a teaching proposal may improve learning, make the classes more interesting and help the students to take real part in them. The learners become the chief builders in the evolution of their own knowledge. The study about Probability problems was part, for many years, of High School only. Yet this subject can be taught to younger students as well, what has been widely recognized by the PCNs, published by MEC. In order to make these learnings related to Probability a reality we must change, which is just something imposed in our text books, in real experiences. It is suggested to toss a coin several times, discuss and reflect about this procedure, helping the students observe and make presumptions about how and why the chance of being winners in a heads or tails game is of 50%. According to the PCNs (BRAZIL, 1998), the notions about Probability must be explored through experiences and simulations to calculate the Probabilities themselves and check expected Ones.
Geometria, modelagem e código de barras na construção de luminárias
(Universidade Federal de São Carlos, 2013-03-21)
Fernandes, Estela Aparecida
;
Soares, Márcio de Jesus
;
https://lattes.cnpq.br/3273672989988386
The presented work aims to allow students to infer about the different concepts by building Mathematicians luminaire. For this, occur following the development of a didactic, teaching methodology that consists in presenting the project to the students who undergo an initial production or initial assessment - production of texts, conversations, problems - from which different activities are performed, worked in modules on the topics. It is then rated the performance obtained through the production end. This methodology was applied to two classes of 2nd year of high school in a public school. The first step began with a presentation of the sequence followed by initial production, which allowed students to exhibit their knowledge of mathematics involved in the production end (luminaire). The proposal focuses on various topics from basic mathematics possible, through different methodologies, the resumption of constant content addressed thus enabling advances in the teachinglearning process. The topics taken up are observed in the plane geometry, which underlies the study of Space Geometry. The practice of mathematical modeling is used to rescue the concept of function with real meaning to students. The news was on account of the discovery of mathematics Barcode. And finally, the closing of the work took place with the presentation of the final production performed by students.
Influência da linhagem da levedura e das condições de cultivo no processo de isomerização e fermentação simultâneas da xilose
(Universidade Federal de São Carlos, 2013-03-21)
Moraes, Guilherme Silveira
;
Zangirolami, Teresa Cristina
;
https://lattes.cnpq.br/4546701843297248
;
https://lattes.cnpq.br/9013240485281830
The conversion of the hemicellulosic fraction in ethanol is a factor that impacts on the economic viability of the second generation ethanol production process from sugar cane bagasse. Hemicellulose from bagasse is a heteropolymer constituted by pentoses and glucose, being xylose the predominant sugar (~ 21 %). Among the available technological alternatives for ethanol production from xylose, SIF process (Simultaneous Isomerization and Fermentation), consisting of xylose conversion to xylulose by glucose isomerase (GI) enzyme and xylulose fermentation by the yeast S. cerevisiae, is considered a promising alternative. The main objectives of the present work were: i) evaluate the performance of different S. cerevisiae strains towards xylulose intake and ethanol productivity; ii) assess the influence of cultivation conditions (temperature, oxygen availability and initial xylose concentration) upon ethanol and xylitol production by the selected strains; iii) define the operation conditions for the continuous SIF process, using a system of fixed bed reactors associated in series. Preliminary experiments were conducted in 50 mL flasks, containing 4 g of pellets with a load of 20 % of immobilized GI, co-immobilized with yeast (load of 10 %) in alginate gel. For the screening of yeasts showing better performance on ethanol production from xylose, two commercial baker´s yeast strains (Itaiquara® e Fleischmann®), three industrial strains (BG-1, CAT-1 e PE-2) and one lab strain (CEN.PK113-7D) were evaluated. These experiments were performed at 35 oC, using a medium composed by xylose (60 g/L), urea (5 g/L), CaCl2 (1.9g/L) and several salts, at initial pH of 5.6. Additional SIF studies were carried out with the selected yeasts Itaiquara®, BG-1 or CEN.PK113-7D under different temperature conditions (40 oC), aeration (15 mL flasks) and initial xylose concentration (130 g/L) for comparison with the results obtained at the standard conditions. For SIF cultures, samples were withdrawal and the concentrations of reducing sugars were determined by DNS method while xylose, xylulose, ethanol and by-products (xylitol, glycerol etc) concentrations were assessed by liquid chromatography. Cell viability was also measured at the beginning and end of the experiment. When comparing the different yeasts, Itaiquara® strain presented the best performance, reaching ethanol concentrations of 22.4 g/L, with a productivity of 2.1 g/Lh. The conversion of xylose was similar for all studied industrial strains as well as among the baker s yeast and lab strains. Concerning the group of additional experiments, at 40 oC, a decrease of viability and ethanol selectivity was observed for Itaiquara®, whereas productivity and selectivity for CEN.PK113-7D. was improved. For the studies conducted under semianaerobic conditions, the yeast BG-1 showed an increase in selectivity and yield. However, the reaction time increased to app. 45 hours. On the other hand, the performance of strain Itaiquara® was not altered by the lower level of oxygen tested. In the experiment with 120 g/L of xylose, more than 40 g/L of ethanol was obtained in 24 hours of cultivation. Thus, we conclude that the SIF process proposed in the present work is a viable alternative for the production of ethanol from xylose or lignocellulosic residues. For the operation of the continuous system composed by fixed bed reactors associated in series, the recommended conditions include the Itaiquara® yeast with a temperature no higher than 35 oC, keeping the total residence time around 10 hours for a feeding supply containing 60 g/L of xylose.
Produção de ácido glucônico e xarope de frutose a partir de sacarose catalisada por enzimas em reator airlift
(Universidade Federal de São Carlos, 2013-03-21)
Mafra, Agnes Cristina Oliveira
;
Tardioli, Paulo Waldir
;
https://lattes.cnpq.br/6868423702339380
The sugarcane sugar (sucrose) is a raw material produced in abundance in Brazil, being attractive to produce high added-value by-products. The gluconic acid (GA) can be obtained by multienzymatic conversion of sucrose, using three enzymes. Invertase, responsible for the inversion of sucrose to glucose and fructose, glucose oxidase (GOD) responsible for the glucose oxidation and catalase (CAT) responsible for decomposition of hydrogen peroxide. In multienzymatic process fructose is obtained as a byproduct, also of great interest to the food, pharmaceutical and chemical industries. In this study, the production of GA from sucrose in airlift reactor is evaluated. Temperature and pH of maximum activity were determined for the enzymes invertase, GOD and CAT , as well as the thermal stability in the absence of substrate. Invertase enzymatic activity was quantified by formation of reducing sugars on a 200 mM sucrose solution at 30 ° C, and pH 4.8. The enzymatic activity of GOD and the CAT were determined by monitoring respectively the formation of H2O2 from a solution of glucose 1 g/L, 25°C, pH 5.0 and the decomposition of H2O2 from a solution of H2O2 35 mM, 25°C, pH 7.5. Invertase showed maximum activity at 45 ºC and pH 5.0; GOD at 55ºC and pH 6.0 and CAT at 25 ° C and pH 8.0, respectively. From the activity profiles as a function of temperature and pH, the operational conditions of 50, 45 and 40°C at pH 5.0 and 6.0 were pre-selected for the multienzymatic process. It was found that the best half-lives times of the soluble enzymes, invertase, GOD and CAT, occurred in the condition of 40°C and pH 6.0, respectively 137, 105 and 98 h. A kinetic study was carried out at 40°C and pH 6.0. The kinetics of the enzyme invertase showed a behavior best predicted by the model of substrate inhibition. Michaelis-Menten model (MM) was fitted to experimental data of GOD and substrate inhibition model best predicted the kinetics behavior of CAT. The proposed kinetic models were used to estimate enzyme/substrate ratio (w/w) used in the production of GA in agitated and aerated and airlift bioreactors. On the other hand, in the batch assays conducted in airlift bioreactor were obtained AG real yields of 80.38 ± 5.69% and global yields of 103.20 ± 13.96% and conversion of sucrose of 98.86 ± 0.97%; obtained after 5 h. A new set of kinetic parameters including volumetric oxygen transfer coefficient (kLa) was based on the experimental data from tests in airlift bioreactor. These showed that Bi-Bi Ping-Pong model both with or without product inhibition correspond satisfactorily to the tendency of the experimental data.
Avaliação experimental da fragmentação do hábitat em comunidades de macroinvertebrados associados a macroalgas
(Universidade Federal de São Carlos, 2013-03-21)
Daunt, Ana Beatriz Pierri
;
Tanaka, Marcel Okamoto
;
https://lattes.cnpq.br/2768658925977757
;
https://lattes.cnpq.br/8306035178191448
Habitat fragmentation is a major cause of biodiversity loss, so understanding the effects of habitat fragmentation on the structure and dynamics of natural communities is very important to biodiversity conservation. This study evaluated whether habitat fragmentation affects the structure of macroinvertebrate communities associated with macroalgae in the sublittoral of a protected shore in the northern coast of São Paulo State. First, we carried out an experiment to evaluate the colonization of the aquatic fauna to substrates with different structural characteristics after two and four weeks for colonization (Chapter II). Our results showed that the tubular plastic net exposed to four weeks of colonization would be efficient to the execution of the fragmentation experiment (Chapter III). Then, we built artificial landscapes that formed large patches, which were later fragmented to analyse the development of communities relative to position within the patches (edge vs. interior) and resulting patch size . Higher taxon richness and gastropod abundance were recorded in the patch edge, but no significant differences were found among patch sizes. We found a significant effect of fragmentation, with lower abundances of Gammaridea (the dominant taxon), Ophyuroidea and Pycnogonida after the experimental fragmentation. Edge environments may shelter higher richness and abundance of organisms due to higher inputs of food and organism settlement. The lack of experimental studies in this systems makes it difficult to determine the appropriate spatial scale to study and to interpret patch size differences. Our results support the importance to preserve seaweed beds for the conservation of macroinvertebrate diversity, independently of patch sizes. Thus, these results can help to understand the effects of habitat fragmentation in marine systems, supporting management actions for biodiversity conservation.
Utilização de mensagens criptografadas no ensino de matrizes
(Universidade Federal de São Carlos, 2013-03-21)
Oliveira, Reinaldo Donizete de
;
Soares, Márcio de Jesus
;
https://lattes.cnpq.br/3273672989988386
The present work aims at showing the development and implementation of a Didactic Engineering on the use of encrypted messages in teaching matrices to students who are attending the second high school year at Esmeralda Soares Ferraz School in the City of Ourinhos-SP. This work begins with a question related to the discouragement and apathy of students in studying mathematics and suggests, taking the teaching of matrices through encrypted messages by transposition of letters, a different approach from those commonly applied, through which, the student eager to solve them, will get engaged and interested in learning, in a simple way, the concepts of matrices and transposed matrices, being protagonist of his/her search for knowledge.
Desenvolvimento de eletrodos de carbono vítreo modificados com nanotubos de carbono para a determinação de analitos de interesse farmacêutico
(Universidade Federal de São Carlos, 2013-03-21)
Oliveira, Geiser Gabriel de
;
Fatibello Filho, Orlando
;
https://lattes.cnpq.br/9859737944357808
;
https://lattes.cnpq.br/6504190570083114
In this work, the development of electroanalytical methods for the determination of methotrexate (MTX), propylthiouracil (PTU), propanolol (PROP) and verapamil (VPM) in pharmaceutical formulations is described. In these methods it was employed a glassy carbon electrode (GC) modified with dihexadecyl hydrogenphosphate (DHP) or polyallylamine hydrochloride (PAH) film containing immobilized multi-walled carbon nanotubes (MWCNTs). Initially, the electrochemical behavior of each modified electrode was studied by cyclic voltammetry at different scan rates for a 1.0 × 103 mol L1 potassium hexacyanoferrate (III) in 0.1 mol L1 potassium chloride solution. Applying the Randles-Sevcik equation, it was observed an increase of the active area of MWCNTs-DHP/GC and MWCNTs-PAH/GC electrodes of 1.5 and 3.1 times respectively in comparision with the GC electrode. The square wave voltammetry, differential pulse voltammetry and linear sweep voltammetry parameters were studied and optimized for each analyte and then it was selected the best technique for the development of the analytical method. In the developed method for MTX determination in pharmaceutical formulations, it was used the GC electrode modified with MWCNTs and DHP (MWCNTs-DHP/GC), employing differential pulse adsorptive anodic stripping voltammetry (DPAdASV) technique after the optimization of experimental conditions. The analytical curve obtained was linear in the MTX concentration range from 5.0 × 10-8 to 5.0 × 10-6 mol L-1, with a limit of detection (LOD) of 1.2 × 10-8. The MTX was quantified in commercial samples and the results compared with an HPLC method, and the relative errors ranged from -4.0 to 4.0%. An analytical method for determination of PTU in pharmaceutical formulations was also developed using a modified GC electrode with MWCNTs within a PAH film (MWCNTs-PAH/GC) and linear sweep adsorptive cathodic stripping voltammetry (LSAdCSV). After the optimization of experimental conditions, the analytical curve was linear in the PTU concentration range from 5.0 × 10-6 to 5.8 × 10-5 mol L-1, with a LOD equal to 1.0 × 10-6 mol L-1. The PTU was quantified in commercial samples and the results were compared with those results obtained using the British Pharmacopoeia method. The relative errors obtained were between -1.0 and 2.0%. Using DPAdASV technique and a MWCNTs-PAH/GC electrode, PROP was determined in pharmaceutical formulations. The analytical curve was linear in the concentrations range from 7.5 × 10-8 to 1.0 × 10-6 mol L-1 PROP, with LOD equal to 6.3 × 10-8 mol L-1 and the results were in close agreement whit those obtained using the Brazilian Pharmacopoeia method at a confidence level of 95 %. The relative standard deviation ranged from 2.5 and 1.2%. Finally, as a fourth electroanalytical method, a square wave adsorptive anodic stripping voltammetry (SWAdASV) was proposed for determination of VPM in pharmaceutical formulations using a MWCNTs-PAH/GC electrode. The analytical curve was linear over the VPM concentration range 5.0 × 10-9 - 1.0 × 10-7 mol L-1, with an LOD of 3.6 × 10-9 mol L-1 . The VPM was quantified in pharmaceutical samples and the results compared with results obtained using the method of the Brazilian Pharmacopoeia.
Recobrimento de sementes silvestres em panela rotatória
(Universidade Federal de São Carlos, 2013-03-21)
Rosso, Giovana Américo
;
Sartori, Dermeval José Mazzini
;
https://lattes.cnpq.br/3207012091734322
In order to minimize the effects caused by the development of Brazil, such as the suppression of riparian forest, one has searched for tree species that have the characteristics needed for the recovery of degraded areas. Given this, studies focus on higher plants of encapsulated wild fruits, especially the Mabea fistulifera Mart. Considering that M. fistulifera reproduces through embryonic units that need to be treated, this study aimed to evaluate the drying of wild fruits with explosive dehiscence and the coating "in natura" seed with gel mixture via coating pan, as well as evaluating the tolerance of embryos related to the immediate effects of the processes. Thus, the experimental procedure consisted of the collection of capsular fruits and extraction of seeds of fruit by drying so were analyzed drying methods via radiation, natural convection, forced convection and coating pan. It was considered for the drying methods analysis the opening fruit speed and seed vigor. Thus, all processes allowed physiological recovery of embryos, but the extraction method via pan promoted the highest opening speed of the fruits. Once performed the extraction, the seeds were separated from the inert material obtaining pure batches of seeds. There were also characterizations of size, shape and specific mass obtaining the results (0,78±0,05) cm, (0,67±0,04) cm and (0,59±0,04) cm for Dmax, Dmédio and Dmim, respectively, form factor (0,75±0,01), specific mass of (1,20±0,01) g/cm³ and apparent mass of (0,82±0,01) g/cm³. Analyzes were also made for chemical seed yielding (82,93±0,11)% of dry matter (19,03±0,78)% crude protein, (1,18±0,11) g/kg calcium (0,65±0,03) g/kg magnesium (0,58±0,04) g/kg phosphorus (13,45±0,33) g/kg potassium (0,70±0,03) g/kg of sulfur. The process of coating seeds, through reaction between sodium alginate gel and calcium chloride salt at different angles of inclination and rotation speed of the coating pan, was also analyzed. Thus, it was found that to achieve the coating of the particles it was necessary to prepare the particle surface by chemical scarification, in order to increase the surface roughness of the seed, followed by rehydration with saturated calcium chloride. This way, it was found that the angle of 25° and speed of 25 rpm generate the greatest quantity of mass adhered on seeds. In addition, tests were performed to verify the efficiency of the coating process, and with the lowest angle set in experimental design was found higher values of efficiency. In tests of particle growth was evaluated that the process time was approximately 8 seconds. Finally, the analysis and processing of data obtained through statistical techniques and equations from literature were performed. In this way, the results contributed to improvements in drying processes of wild fruits and the coating of seeds of the pioneer species M. fistulífera.
Relações entre ambiente, traços, composição e funcionamento de comunidades vegetais de cerrado
(Universidade Federal de São Carlos, 2013-03-21)
Carvalho, Gustavo Henrique de
;
Batalha, Marco Antônio Portugal Luttembarck
;
https://lattes.cnpq.br/3893228815181339
;
https://lattes.cnpq.br/0896575446907453
Identifying the relative importance of deterministic and stochastic factors to the assembly of local communities has been tagged as one of the fundamental questions ecologists need to answer. Niche-based theories predict that the subset of species from the regional pool that occur in a local community presents a trait distribution that has been shaped by biotic and abiotic factors. The neutral theory, on the other hand, predicts that the species that compose the regional pool are functionally equivalent. Local communities formed from stochastic processes would, thus, present abundances not significantly different from those in the species pool. We collected traits on all woody individuals in 100 25m2 quadrats to test if we could predict local abundances using a pool of species and traits. We combined plots into large scale, intermediate scale, and fine scale samples. We used random sampling, spatial distance, soil characteristics, and fire to assemble species in different scales and environmental gradients. In the Brazilian cerrado, fire and nutrient-poor soils are likely promoters of habitat filtering. To test if traits improved the predictions generated by the information present in the pool, we used maximum entropy models coupled with permutation tests. We could accurately predict local abundances of the 73 species in the pool. Dispersal limitation was the main factor assembling communities at all the scales we studied, but the effects of stochasticity became more important as the scale became local. Traits explained little of the uncertainty present in local abundances, but coupled with pool frequencies they yielded large coefficients of determination.