Navegando por Data de Publicação, começando com "2012-06-22"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 6 de 6

Desenvolvimento de biossensores utilizando nanotubos de carbono e nanopartículas de ouro
(Universidade Federal de São Carlos, 2012-06-22) Janegitz, Bruno Campos; Fatibello Filho, Orlando; https://lattes.cnpq.br/9859737944357808; https://lattes.cnpq.br/7746094938977989
First, a glassy carbon electrode modified with functionalized carbon nanotubes (CNTs) and glucose oxidase was proposed. Cyclic voltammetry of GOx immobilized onto the surface of CNTs showed a pair of well-defined redox peaks, which corresponds to the direct electron transfer of GOx, with a formal potential of -0.418 V in 0.1 mol L-1 phosphate buffer solution (pH 7.0). An apparent heterogeneous electron transfer rate constant of 1.69 s-1 was obtained. The determination of glucose was carried out by square wave voltammetry and the developed biosensor showed good reproducibility and stability. The second biosensor was a boron-doped diamond electrode modified with AuNPs electrodeposited and Tyrosinase (Tyr). The occurrence of direct electron transfer between the electrode surface and the Tyr active site was verified by cyclic voltammetry, yielding the following parameter values: formal redox potential of 0.115 V. The developed Tyr-AuNPs/BDD biosensor exhibits good sensitivity, stability, and reproducibility for the determination of phenol by SWV. The third proposed biosensor was developed based on acetylcholinesterase, gold nanoparticles and poly (allylamine hydrochloride) film on the surface of screen printed carbon electrodes (SPCE) for the determination of pesticides using a portable micromachined flow injection system. The AChE-AuNPs/SPCE biosensor presented a limit of detection of 5.0 x 10-8 mol L-1 for Diuron. In addition, the biosensor showed good sensitivity, stability and reproducibility for Diuron determination in water samples. Finally, a novel electrochemical immunosensor using electrodeposited gold nanoparticles modified-screen-printed carbon electrodes (AuNPs/SPCEs) was developed for the determination of prolactin.The variables involved in the preparation of the immunosensor and the electrochemical detection step were optimized, which presented a limit of detection of 10 ng mL-1. The analytical usefulness of the immnunosensor for the analysis of real samples was demonstrated by analyzing human serum spiked with PRL at two different concentration levels.
O gênero musical samba como conteúdo cultural no ensino de PLE : uma experiência com aprendentes hispanofalantes
(Universidade Federal de São Carlos, 2012-06-22) Tonelli, Fernanda; Barbosa, Lúcia Maria de Assunção; https://lattes.cnpq.br/5030878430187815; https://lattes.cnpq.br/7748078290997968
This Master research focuses the use of samba as a means of working culture in Portuguese as a Foreign Language class. For this, we conducted a content-based course about samba for Spanish speakers to analyze how the samba can be configured as a way to teach cultural aspects related to language and to identify the impressions of these learners about learning Portuguese through this cultural content. We assume the proposal that the place of language is the same as the culture, so there is no way to separate these two elements in the teaching/learning a foreign language. As a social manifestation of great representative for the Brazilian culture, samba was chosen in this research as a content that can reveal elements of cultural and national identity, thus, should contribute to the learning of Portuguese as a foreign language. The methodology adopted is qualitative and ethnography based and the procedures and data collection instruments were observation and notes, classes audio recording and questionnaires made at the beginning and at the end of the course. In this research, we verify the validity of using the samba as a pedagogical resource for teaching PLE, acting both as an initiator of cultural reflection in the classroom and as a voice that collaborates for the cultural discussion that is already started in class. Moreover, the samba was perceived by students as a source of cultural contact by several themes that his lyrics convey.
Propriedades eletrônicas e estruturais do Cu/ZrO2 aplicadas à reação do etanol
(Universidade Federal de São Carlos, 2012-06-22) Sato, André Gustavo; Bueno, José Maria Corrêa; https://lattes.cnpq.br/0157452280626031; https://lattes.cnpq.br/3495469721481454
Copper is a typical catalyst for dehydrogenation of ethanol to acetaldehyde. However, copper supported on ZrO2 was found to be extremely active and selective to convert ethanol directly to ethyl acetate. Several reports in the literature have been made attempting to explain the catalytic properties of the solid Cu/ZrO2. Nevertheless, the nature of active sites, the role of copper, ZrO2 and their interface require further study with the use of more accurate techniques. Since the precise identification of the active sites for the occurrence of this reaction is the first step to propose mechanisms that help to understand it. In this work, we conducted a study using copper supported on three different polymorphs of ZrO2: monoclinic (m-ZrO2), tetragonal (t-ZrO2) and amorphous (am-ZrO2). Thus, the interaction of copper phase with ZrO2 would be limited to changes in textural, structural and electronic properties intrinsic to each polymorph, and not to the chemical composition in the case of we chose other support oxide. With an innovative and challenging proposal, this thesis developed by itself conducting in advanced characterizations of the structure and electronic state of the Cu/ZrO2 activated in H2. The analytical approach adopted for the characterization of the Cu/ZrO2 was performed by monitoring its in situ activation by the temperature programmed reduction in H2 with technique using synchrotron radiation like X-ray Absorption spectroscopy. Although reactions in heterogeneous catalysis proceed on the surface of an active catalyst, the properties of the surface can be influenced or determined by the bulk of the catalyst. X-ray photoelectron spectroscopy and diffuse reflectance infrared Fourier transform spectroscopy of adsorbed CO were used for Cu/ZrO2 active surface characterization. Catalytic tests show that the direct and efficient formation of ethyl acetate from ethanol depends on the chemical interface between Cu-ZrO2. However, it was found that higher performance of these catalysts to ethyl acetate does not occur at any interface. The property of Cu-ZrO2 interface varies according to the ZrO2 polymorphism, with the best performance in the ethyl acetate formation observed in the catalyst Cu/m-ZrO2. The premature loss in ethyl acetate selectivity observed at temperatures above 250 °C in Cu/m-ZrO2 revealed that the origin of its interface property can be associated with the oxygen mobility and lability from the bulk of the catalyst. Through the redox mechanism promoted by oxygen vacancies in am-ZrO2 and in m-ZrO2, an electron transfer between support and Cu surface would be established as to form highly active species to ethyl acetate.
Confiabilidade humana e o funcionamento normal de uma refinaria de petróleo
(Universidade Federal de São Carlos, 2012-06-22) Borges, Fábio Morais; Menegon, Nilton Luiz; https://lattes.cnpq.br/5461487552981919; https://lattes.cnpq.br/9440105038133106
There is a distance between a design as planed and one developed effectively. It varies according to both the constraints involved in the design process and accuracy of design conception. Many projects are designed without taking into account the user‟s real needs. It makes difficult or impossible the developing of the tasks. To improve this scenario, the Ergonomics seeks to understand the activity to incorporate the workers perspective in the design and operation of sociotechnical systems. To reach this goal, it uses the Activity Analysis approach. It is on the situated activity that emerge the own skills and characteristics of human, in order to ensure the system stability. Thus, the human is the reliability factor of the system. It is called Human Reliability. It follows in this research, the assumption that the Activity Analysis is the most appropriate method to provide subsidies for a design focused on the needs of the task, increasing the supports that help ensure the operational reliability of the system. It were used analyzes carried out in a Petroleum Refinery for 3 years and a half of study. They enabled the development of designs that take into account the role of refinery workers as the most experts of his work. The analyzes used photographs and videos to understand more deeply the activity of the refinery workers. From these analyzes were extracted actions and strategies used to refinery workers to correct instabilities that are present at all times. It can generate incidents which lead to lose of control of the system as a whole, if not noticed at time. The workers do it using the representation of the system. The actions were classified into five categories, according to the elements mobilized for the recovery of the normal state of the system. It is proposed a Design Resilient Model that incorporates these actions and aims to ensure that new strategies, built from new constraints, are constantly evaluated and incorporated on the project, if possible. It emphasizes that even with the construction of the Model, it been possible realize that the conflicts that operators face in the daily routine of the Refinery are dynamic and cannot be translated for a Model. There will always be a remnant. There will always be hysteresis. Thus, the activity will continue to be the place where operators respond to these conflicts. Showing that, for the most appropriate to the needs of the task that is a model, the refinery workers will continue having to resolve conflicts in situated action.
De cleaner a waiter: trajetórias de trabalhadores brasileiros em Londres
(Universidade Federal de São Carlos, 2012-06-22) Martins Junior, Angelo; Lima, Jacob Carlos; https://lattes.cnpq.br/9244132532446607; https://lattes.cnpq.br/2540009751058701
The aim of this dissertation is to analyze a group of Brazilian workers who are in London doing some "unskilled job" in the service sector. It is intended to verify: the alleged reasons to migrate; how it developed throughout the process of displacement, arrival and adaptation in the new society; the working conditions that these immigrants are submitted; the social networks used to obtain and maintain the work; and the intra-Community relations. In a context of mobility of people between continents and region, social networks act as mediators that facilitate these movements, since the social contacts provide initial information to obtain access to housing, work and other material or symbolic goods. However, those individuals who "constitute social ties" are not always supportive and these links will not provide gains to all, and it may exclude some while includes others. Inserted into a new social logic and working on activities that they would not perform in their country of origin, these immigrants assume new values in relation to work, building new forms of social differentiation and justification. The research is the result of two distinct moments. First an exploratory study was conducted from an experience as student and casual worker for nine months in London, in which was developed ethnography of social relations and work in the "community" of informal Brazilian workers. Secondly, in-depth interviews were conducted in order to recover the trajectory of life of these migrant.
Caminhos para a transição agroecológica: estudo com uma família do assentamento Fazenda Ipanema, Iperó (SP)
(Universidade Federal de São Carlos, 2012-06-22) Avila, João Eduardo Tombi de; Assad, Maria Leonor Ribeiro Casimiro Lopes; https://lattes.cnpq.br/0379324550884468; https://lattes.cnpq.br/0701072376750140
Many farmers consider Agroecology a tool to produce sustainably. By changing their production systems, changing crops and inputs applied, aiming at a sustainable system, the family farmer search a transition agroecology. However, few among them can produce or advance in agroecological transition. A reason for this difficulty may be related to biomass production in quantity and quality to ensure the agroecosystems sustainability. The family agroecosystems tend to have greater biodiversity than large farms due to a tendency to polycultures, self, family pluriactivity, among other strategies. In this local biodiversity, plants play a key role and can be considered co-products. This study aimed to characterize a unit of production and family life (UPVF) adopting management practices aimed at agroecological transition, to discuss the importance of plant biomass in this transition process and to propose alternatives to achieve the fertility system. The research was developed at Iperó in Ipanema Farm settlement in the State of Sao Paulo. The UPVF studied occupies a plot of eight hectares and is divided into seven sectors of production. The family with whom this work was developed live in the settlement since 1992. The research aimed to detail the system features and the complexity of relationships in order to describe and analyze a case study setting. It was found that the biomass produced in UPVF did not meet the nutritional demand of the main sector of commercial product, the banana orchard. The proposed redesign sought to ally virtuous experiences and scenic beauty, attractive for humans. Thus, the UPVF redesign aimed at promoting the cradle areas of fertility, assisted in the production of plant biomass in abundance and quality (diversity), preferably in well accessible, as the surrounding residences, places of daily traffic and nearby areas containment of animals. Thus, it is expected to 16 contribute to the sense of pride in the family for the successful transformation of the local landscape and the awareness of what it represents.