Alquilação redutiva da quitosana a partir do glutaraldeído e 3-amino-1-pr

Chitosan derivatives were prepared by reductive alkylation using glutaraldehyde and 3-amino-1-propanol. The reducing agent used was the sodium borohydride. Tests of solubility, stability and viscosity were performed in order to evaluate these parameters effects in the reaction conditions (molar ratio of the reactants and presence of nitrogen in the reaction system). The molecular structure of commercial chitosan was determined by infrared (IR) and hydrogen nuclear magnetic resonance spectroscopy (1H NMR). The intrinsic viscosity and average molecular weight of the chitosan were determined by viscosimetry in 0.3 M acetic acid aqueous solution 0.2 M sodium acetate at 25 ºC. The derivatives of chitosan soluble in aqueous acidic medium were characterized by 1H NMR. The rheological behavior of the chitosan and of the derivative of chitosan (sample QV), which presented the largest viscosity, were studied as a function of polymer concentration, temperature and ionic strength of the medium. The results of characterization of the commercial chitosan (the degree of deacetylation obtained equal 78.45 %) used in this work confirmed a sample of low molar weight (Mv = 3.57 x 104 g/mol) and low viscosity (intrinsic viscosity = 213.56 mL/g). The chemical modification of the chitosan resulted in derivatives with thickening action. The spectra of 1H NMR of the soluble derivatives in acid aqueous medium suggested the presence of hydrophobic groups grafted into chitosan in function of the chemical modification. The solubility of the derivatives of chitosan in 0.25 M acetic acid aqueous solution decreased with increase of the molar ratio of the glutaraldehyde and 3-amino-1-propanol in relation to the chitosan. The presence of nitrogen and larger amount of reducing agent in reaction system contributed to the increase of the solubility, the stability and the viscosity of the systems. The viscosity of the polymeric suspensions in function of the shear rate increased significantly with polymer concentration, suggesting the formation of strong intermolecular associations. The chitosan presented pseudoplastic behavior with the increase in polymer concentration at a low shear rate. The derivative QV presented pseudoplastic behavior at all concentrations used and in a large range of shear rate. The viscosity of chitosan in solution decreased with an increase of the temperature and with the presence of salt. However, there was an increase of the viscosity of the chitosan solution at higher temperature (65 ºC) and ionic strength of the medium which were promoted by hydrophobic associating of the acetamide groups. The solutions of the chitosan derivatives (sample QV) were significantly more viscous than chitosan solution and showed higher thermal stability in the presence of salt as a function of the hydrophobic groups grafted into chitosan backbone

Estudos de adsorção de tetraciclina em partículas de quitosana

Due to its physico-chemical and biological properties, related to the abundance and low cost of raw material, chitosan has been recognized as a material of wide application in various fields, such as in drug delivery systems. Many of these properties are associated with the presence of amino groups in its polymer chain. A proper determination of these amino groups is very important, in order to properly specify if a given chitosan sample can be used in a particular application. Thus, in this work, initially, a comparison between the determination of the deacetylation degree by conductometry and elemental analysis was carried out using a detailed analysis of error propagation. It was shown that the conductometric analysis resulted in a simple and safe method for the determining the degree of deacetylation of chitosan. Subsequently, experiments were performed to monitor and characterize the adsorption of tetracycline on chitosan particles through kinetic and equilibrium studies. The main models of kinetics and adsorption isotherms, widely used to describe the adsorption on wastewater treatment systems and the drug loading, were used to treat the experimental data. Firstly, it was shown that an apparent linear t/q(t) × t relationship did not imply in a pseudo-second-order adsorption kinetics, differently of what has been repeatedly reported in the literature. It was found that this misinterpretation can be avoided by using non-linear regression. Finally, the adsorption of tetracycline on chitosan particles was analyzed using insights obtained from theoretical analysis, and the parameters generated were used to analyze the kinetics of adsorption, the isotherm of adsorption and to ropose a mechanism of adsorption

Análise de grafos aplicada a relatos de sonhos: ferramenta diagnóstica objetiva e diferencial para psicose esquizofrênica e bipolar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Deliberação e participação: dinâmica e efetividade do conselho de saúde de Mossoró/RN – 2009/2012

The social participation in Brazil takes a new impetus with the (re)democratization process of the Brazilian society and is strengthened by the resurgence of the civil society and the 1988 Constitution. In this context, the study is conducted with the scope to verify the effectiveness of deliberative Municipal Health Council of Mossoro (CMSM), with theoretical and methodological support based on the following models: the participatory normativity, which measures the degree of institutionalization, democratization and council representation; and the effectiveness of deliberative that, from the calling capacity and agenda of the participants, from the kinds of manifestation, from the decisions and the council’s office, that measures the degree of effectiveness of the deliberative council. It appears, thus, that the council has an average degree of effectiveness deliberative, standing out as means an institution that practice, despite the existence of obstacles and challenges, the role of control over municipal health policies, due, among other factors, the conservative political context, the asymmetry of resources between the counselors, the little substantive participation of the actors who attend its meetings, either counselor or not, and in particular, the reduced influence of the members in its decision-making process. In public management of Mossoro, social participation, especially social control over public actions, face, today, great number of difficulties to be held. The study recognizes that, in such circumstances, the council partially fulfills the role for which it was created, what does not impede, however, be characterized as an important deliberative space, since it allows the participation of representatives of the various segments of the state, society, their demands and intentions. Overcoming such obstacles moves through the interest of civil society to wake up and fight for the spaces in these institutions.

As condições de trabalho e a satisfação profissional: dimensões do profissionalismo docente no ensino médio

The dissertation is developed in the Research Base of Teacher Training and Professionalization of Universidade Federal do Rio Grande do Norte as a way to discuss the professionalization of High School teachers in Natal. It is a study linked to the research The context of teaching practice and professionalism: the case of high school teachers and sponsored by CNPq, with the objective of characterizing working conditions and job satisfaction as dimensions to the teacher professionalism in high schools. In this study we prioritized the focus on professionalization in national and international discussions, which combines the aspects of teaching in its historical, social, political and economical path, in order to reflect about its evolutional elements in the hierarchy of professions and establish a relation to high school teaching. To develop this relation we elaborated some questions that are considered relevant, such as: How does the high school teacher evaluate his/her working conditions to his/her professional practice? What level of satisfaction does the high school teacher have regarding his/her professional practice? What expectations does the high school teacher have in relation to his/her professional development? The answers to those questions were according to the high school teachers considerations shown in the questionnaire, which was structured with open and closed questions. These questions gave better adequacy to the teachers evaluations about their working place and the situations they experience in their working conditions, provoking job satisfaction and expectations for professional growth. The description of the teachers perception about working conditions, job satisfaction and expectation of professional development can explain the distinct factors that characterize these categories in the working context, although the conclusive results, in general, do not show a direct relationship between the categories studied. Some factors that teachers attribute as causes of bigger difficulties in working conditions and work activity itself are: working time, salary, professional status, school s infrastructure, and school s social context. These factors are similarly related to the degree of job satisfaction, without showing interference in the professional expectations

As crenças docentes sobre a criatividade a as práticas pedagógicas criativa: o caso do programa do ensino médio inovador no RN

Estamos vivendo no século da criatividade em que os sujeitos precisam ser estimulados a criar e inovar nos processos de aprendizagem escolar. Nesse sentido, a criatividade precisa ser compreendida como um bem cultural, um direito de todos e uma condição histórica e cultural do sujeito, e não como uma capacidade inerente ao sujeito ou pertencente alguns poucos eleitos. Para que a criatividade do aluno seja estimulada, faz-se necessário, dentre outros elementos, que o conhecimento profissional do professor considere as crenças como componente de seu processo de profissionalização com o objetivo de reconhecer o seu papel e influências como formas de nortear as ações profissionais docentes. Para tanto, a presente tese tem o objetivo de estudar as crenças dos professores sobre a criatividade dos estudantes no Ensino Médio Inovador. O ensino, nessa perspectiva, mais especificamente, o ensino médio precisa inovar-se, e nesse processo, o Programa Ensino Médio Inovador PROEMI emerge como uma das iniciativas das políticas públicas educacionais vigentes. Para tanto, no intuito de fundamentar as nossas discussões dialogamos com autores que discutem a criatividade no contexto da educação, às crenças, o conhecimento profissional do professor e o ensino médio. Nessa pesquisa, 207 professores que atuam no ensino médio em escolas estaduais na cidade de Natal e sua Região Metropolitana dentro do PROEMI constituíram-se em nosso público-alvo. O instrumento de coleta de dados foi um questionário normativo de crenças contendo perguntas fechadas e abertas. Para a organização dos dados utilizamos os softwares estatísticos R. 2.15.1 e o Modalisa. O tratamento dos dados se deu mediante análises estatísticas como a análise descritiva dos enunciados, da média, do desvio padrão e a Análise de Componentes Principais ACP em relação aos resultados oriundos das perguntas fechadas e a análise de conteúdo em se tratando dos resultados referentes às perguntas abertas. Os resultados corroboraram com a tese de que os professores apresentam em suas crenças a predominância do enfoque tradicional ou clássico da criatividade, ou seja, creem-na como algo inato ao ser humano e que se desenvolve independentemente dos fatores sociais e culturais. No tocante às principais características do aluno criativo, a autonomia e o alto grau de originalidade em sua aprendizagem se destacaram, dentre outras características. Suas crenças, em relação aos elementos que inibem a criatividade do aluno apontaram que a escola, ao privilegiar os conteúdos escolares compromete a criatividade dos alunos e sobre os elementos que favorecem, destacaram-se as áreas da Arte, da Educação Física e da Literatura como disciplinas, que preferencialmente, desenvolvem a criatividade dos alunos no contexto escolar. Assim, constatamos que as crenças dos professores se configuram de forma reducionista e inatista e que precisam, urgentemente, ser repensadas para que não continue a comprometer o desenvolvimento da criatividade do aluno no contexto escolar, e nesse caso, as crenças se constituem em um dos elementos básicos da profissionalização docente que precisam constantemente ser repensadas e incluídas nas discussões sobre a formação e atuação docente, principalmente, dentro do PROEMI que tem como objetivo principal inovar e estimular a criatividade dos alunos no ensino médio

Gestão ambiental na educação: um estudo sobre fatores que afetam o comportamento ambiental de professores do ensino médio, na cidade de Floriano-PI

The present work sets out environmental issues in educational field. The aim of this research was to investigate the factors capable to influence the environmental behavior of the teachers in High school of the public school in Floriano, state of Piaui. For this, the methodology utilized an explanatory and descriptive search like a survey; questionnaires were applied with open and close questions establishing shifts that made up the following aspects; knowledge, behavior, responsibility, participation and trait of the teachers. The statistic techniques to analyze the data were descriptive analysis and analysis of multiple regression. The results reveal that teachers care about the real surrounding problems and believe that the school must develop ambient activities to stir the consciousness, it is important to the environmental improvement of the city. However, the results point out that are developed little activities related to theme concerned, besides the level of ambient consciousness given to the students are median. It was observed that teachers have little knowledge about theme like Agenda 21 and ISO14000. After identifying some factors of environmental knowledge, it was showed recommendations. The Agenda 21 recognizes in the educational field a mean of popular consciousness; the school should develop an education according to national policy of the environmental education

Um estudo de aplicação das teorias da expectativa e da ancoragem na motivação para o desempemho de alunos do ensino médio

This thesis presents a study on Tversky & Kahneman s (1974) Anchoring theory, and Vroom s (1964) Expectance theory in the context of education and students motivation. It is surveyed 424 students of a secondary and agricultural technical school in Brazil Northeast (EAJ). The survey form try to capture the Vroom s Expectance Theory constructs of Valence, Instrumentality, Expectation and Motivational Force, and also the Tversky and Kahneman Anchoring effect in terms of grade expected. The main findings suggest that the minimum grade required by the school is much strong in driving the students motivation and performance than the Expectancy Theory. It was found that the different grades required drive the students to pursue different grade in the same way

Vozes em diálogo na escola : uma análise de posicionamentos sobre a disciplina língua portuguesa no ensino médio integrado à educação profissional do IFRN

Esta investigación toma como tema la asignatura Lengua Portuguesa en el contexto de la enseñanza media integrada a la educación profesional, implementado en el año de 2005, en el Instituto Federal de Educação, ciência y tecnología del Rio Grande do Norte. En el ámbito general, objetiva analizar las voces reveladas en posicionamientos sobre la asignatura Lengua Portuguesa en este contexto. En este estudio, el uso del adjetivo integrado es comprendido como revelador de una formación escolar no basada en investigaciones dicotómicas, sobre todo en aquellas que evidencian una separación entre el conocimiento y el ejercicio profesional. Se buscó aporte teórico en los debates del área de educación, sobre formación integrada, en la visión de contemporaneidad de Bauman y en la concepción de lenguaje de M. Bakhtin. El corpus se compone de material empírico de la naturaleza cuantitativa y cualitativa, obtenido por medio de aplicación de cuestionarios con alumnos y profesionales, además del análisis documental de los PCNEM y de las OCEM, a lo que se refiere a asignatura Lengua Portuguesa. El direccionamiento metodológico es guiado por el paradigma cualitativo inserido en una perspectiva socio-histórica y eligió como categoría de análisis el concepto de voces sociales. Los resultados indican que la asignatura Lengua Portuguesa, en la perspectiva de integración con el mundo del trabajo, adquiere, en mayor o menor grado, en lo observado en los documentos oficiales y en los posicionamientos de alumnos y profesionales de la enseñanza media integrada a la educación profesional del IFRN, un perfil cuya esencia, lejos de asumir características de una enseñanza instrumental reductora, requiere una concepción de lenguaje que esté en sintonía con el mundo del trabajo de la sociedad contemporánea, una sociedad cada vez más abierta a la pluralidad de opiniones y a la ambivalencia de sentidos

Estudos de adsorção de tetraciclina e cromoglicato em partículas de quitosana

Among the polymers that stand out most in recent decades, chitosan, a biopolymer with physico-chemical and biological promising properties has been the subject of a broad field of research. Chitosan comes as a great choice in the field of adsorption, due to their adsorbents properties, low cost and abundance. The presence of amino groups in its chain govern the majority of their properties and define which application a sample of chitosan may be used, so it is essential to determine their average degree of deacetylation. In this work we developed kinetic and equilibrium studies to monitor and characterize the adsorption process of two drugs, tetracycline hydrochloride and sodium cromoglycate, in chitosan particles. Kinetic models and the adsorption isotherms were applied to the experimental data. For both studies, the zeta potential analyzes were also performed. The adsorption of each drug showed distinct aspects. Through the studies developed in this work was possible to describe a kinetic model for the adsorption of tetracycline on chitosan particles, thus demonstrating that it can be described by two kinetics of adsorption, one for protonated tetracycline and another one for unprotonated tetracycline. In the adsorption of sodium cromoglycate on chitosan particles, equilibrium studies were developed at different temperatures, allowing the determination of thermodynamic parameters

Hábito alimentar e percepção ambiental : um estudo de caso com estudantes do Ensino Médio em Natal-RN

This study has as objective to examine the level of perception of high school students from two private schools in Natal-RN about the existence of a direct link between alimentary habit and its effects on environmental. The research was lead with 433 students, who had their school alimentary habits investigated according to the 24-hour recall method and presents the results of data collection from their opinions on participating in the generation of industrialized solid residues and their yearnings about the improvements of the standard of the food offered in the school. The students show a high rate of grading age for level at school, traditional family structure, riding, predominantly, by car or by bus in the house-school-house way, have generally all three important meals at home, feed frequently at their school, getting it from their won school, which included, mainly, soft drinks and fried or grilled appetizers; show a good knowledge about selective collectors, however with a high variation in their correct use. They show significant approval in the existence of a connection between their alimentary habits and debased effects about environmental and consider their food compounds at school could improve the offering of health/natural food, slowing industrialized foods, which are highly used, sometimes. The study on the students knowledge and concern level with regard to the interface alimentary habit-environmental impact allowed delimitating some of the mainly involved components in the alimentary choices of the same students in the school environment, what might help to develop a set of proposals that stimulates the formation of a responsible consumption standard among teenagers and the need of a consideration about the consequences of their choices

Uma justificava da validade do teorema fundamental da álgebra para o ensino médio

Among several theorems which are taught in basic education some of them can be proved in the classroom and others do not, because the degree of difficulty of its formal proof. A classic example is the Fundamental Theorem of Algebra which is not proved, it is necessary higher-level knowledge in mathematics. In this paper, we justify the validity of this theorem intuitively using the software Geogebra. And, based on [2] we will present a clear formal proof of this theorem that is addressed to school teachers and undergraduate students in mathematics