Caracterização do óleo de carnaúba para uso como biolubrificante

Lubricant is responsible for reducing the wear on the friction protect the metal against oxidation, corrosion and dissipates excess heat, making it essential for the balance of a mechanical system, consequently prolonging the useful life of such a system. The origin of lubricating oils is usually mineral being extracted from the petroleum. But the search for a new source of production of lubricants and fuels it is necessary to meet future demands and reduce the possible environmental damage. For this reason, looking alternative means to produce certain products derived from petroleum, such as biodiesel, for example. Returning to the realm of lubricants, also one realizes this need for new raw materials for their production. Vegetable oil is a renewable resource and biodegradable, and its use entails advantages in environmental, social and economic. The development of this project aims to characterize the carnauba oil as a lubricant plant, or biolubricant. To analyze the oil carnauba tests as checking density, flash point, fire point, viscosity, viscosity, acid number, pH, copper corrosion, thermal conductivity and thermal resistivity were developed. In addition, for conducting the wear on the friction and the gradient of the system temperature, the analysis equipment is designed for wear on the friction. Based on these results, it is observed that the oil carnauba show good correlation to its application as biolubricant

A energia e suas implicações no ensino-aprendizagem da química

The area of Education in Chemistry in Brazil has appeared over 30 years and its growth has been accelerated by the need of comprehension of the processes of teaching and learning in chemistry. Many researches, in this area, has among its investigation objects the teaching tools like teaching materials and the learning processes of students in high school and basic education, but when dealing with higher levels of education, they are seldom portrayed. This study aimed to investigate the General Chemistry textbooks with respect to approach the concept of energy; know the main ideas of graduate students in Chemistry on the relation of the concept of energy and chemical transformations; finally, developing a cicle of studies with the proposition of an approach wich inter-relate the concept of energy and its implications in the teaching-learning process of a chemical transformation. To do so, we used as instruments a questionnaire, press conference, conceptual map and experimental activities. All activities of the study cicle were videotaped and recorded, transcribed and the results organized in tables. For the activities of the study cicle texts that have been developed and inter-relating concepts of chemistry and energy, which in turn gave theoretical support to the activities in the cycle. In the analysis it was used as a theoretical content the analysis of Laurence Bardin. The results revealed that the analysis of the book might be perceived that not always the concept of energy is used in order to generate the abstract thought of chemical transformations, but that the main macroscopic thermodynamic variables are present in the explanation of these transformations. During the study cicle, were studied two chemical reactions: the first one, made possible to approach the macroscopic dimension to quantify the concept of energy and the second one, made possible to demonstrate the macro and microscopic dimension of the concept of energy during a chemical transformation. In all reactions proposed, students used, in most of the times, as explanations, only macroscopic observations of the reactions under study and failed to realize that the concept of energy can be used to explain macro and microscopic chemical transformation. As a final action of the study cicle, students requested further discussion, to clarify the link between the concept of energy and the meanings constructed in the process of studying the reactions. This is done through an oral explanation, during the cycle, and registered in this thesis and attempts to show the interrelationship existing conceptual

Sonho e cura: o culto de Asclépio em Epidauro entre os séculos IV e II a. C.

Profound changes have marked Greek society from the fourth century B.C.. Conquests, wars and epidemics altered drastically the Greek’s posture regarding his public life, his conception of gods and hence the construction of their spaces, whether sacred or profane. Through the fonts, we perceived that the cult of god Asklepeios turned very popular, in this context, for the peculiar way that the god relates to his devotees, through the dreams. We know that the dream was held, for the Greeks, as a space of real existence, it was sacred, and could be accessed in the healing rituals of Asklepios. Our work intends, thereby, to understand the curious and peculiar oniric space, mainly through the inscriptions, architectural structures of the sanctuary and the ancient texts that refer to the context of the period, because we understand that this space was the essential condition for the popularization of the cult, it placed the individual in direct contact with the divinity, a rare closeness between men and gods accepted by the greek imagery until then.

Caracterização Hematológica e Imunofenotípica em Pacientes com Leucemia Linfoblástica Aguda

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Tratamentos de fibras de carnaúba [copernicia prunífera (miller) h. e. moore] para o desenvolvimento de compósito biodegradável com matriz de polihidroxibutirato

The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers

Modificação superficial de filmes de poliéster usando plasma a baixa temperatura

A polyester film has a vast application field, due some properties that are inherent of this kind of material such as, good mechanical resistance, chemical resistance to acids and bases and low production cost. However, this material has some limitations as low superficial tension, flat surface, low affinity to dyers, and poor adhesion which impede the use of the same ones for some finality as good wettability. Among the existent techniques to increase the superficial tension, plasma as energy source is the more promising technique, because of their versatility and for not polluting the environment. The plasma surface polymeric modification has been used for many researchers, because it does not affect the environment with toxic agents, the alterations remains only at nanometric layers and this technique shows expressive results. Then, due to its good acceptance, polyester films were treated with oxygen plasma varying the treatment time from 10 to 60 min with an increase of 10 min to each subsequent treatment. Also, the samples were treated with a gas mixture (nitrogen + oxygen) varying the percentage of each gas the mixture from 0 to 100%, the treatment time remaining constant to all treatments (10 min). After plasma treatment the samples were characterized by contact angle, surface tension, Raman spectroscopy, Infrared attenuated total reflection (IR-ATR) and atomic force microscopy, with the aim to study the wettability increase of treated polyester films as its variables. In the (O2/N2) plasma treatment of polyester films can be observed an increase of superficial roughness superior to those treated by O2 plasma. By the other hand, the chemical modification through the implantation of polar groups at the surface is obtained more easily using O2 plasma treatment

Incorporação de resíduo cerâmico para prevenção da retrogressão da resistência de cimentos de poços de petróleo submetidos à injeção de vapor

Steam injection is the most used thermal recovery method of oil nowadays because of the high degree of development of the technique that allows high recovery factors. However, injection of superheated steam into the reservoir affects the entire structure of the well, including the cemented layer that presents a retrogression of compressive strength and increases the permeability due to formation of more crystalline and denser phases at temperatures above 110 °C. These changes result in failures in the cement that favor the entrance of formation fluids into the annulus space resulting in unsafe operations and restrictions in the economic life of the well. But the strength retrogression can be prevented by partial replacement of cement by silica-based materials that reduce the CaO/SiO2 ratio of cement slurries changing the trajectory of the reactions, converting those deleterious phases in phases with satisfactory mechanical strength and permeability. The aim of this study was to evaluate the behavior of a ceramic waste material rich in silica in partial and total substitution of a mineral additive used to fight the strength retrogression of cement slurries subjected to high temperatures. The evaluation was made by compression, X-ray diffraction (XRD) and thermogravimetry (TG/DTG). The samples were submitted to a cycle of low temperature (38 °C) for 28 days and a cycle of low temperature followed by exposure to 280 ºC and 1000 psi by 3 days. The results showed that slurries with additions of up to 30% of the waste material are not enough to prevent the strength retrogression, while slurries with additions of the waste material combined with silica flour in various proportions produced hydrated products of low Ca/Si ratios that maintained the compressive strength at satisfactory levels

Conversão térmica e termocatalítica à baixa temperatura do óleo de girassol para obtenção de bio-óleo

The use of biofuels remotes to the eighteenth century, when Rudolf Diesel made the first trials using peanut oil as fuel in a compression ignition engine. Based on these trials, there was the need for some chemical change to vegetable oil. Among these chemical transformations, we can mention the cracking and transesterification. This work aims at conducting a study using the thermocatalytic and thermal cracking of sunflower oil, using the Al-MCM-41 catalyst. The material type mesoporous Al-MCM-41 was synthesized and characterized by Hydrothermical methods of X-ray diffraction, scanning electron microscopy, nitrogen adsorption, absorption spectroscopy in the infrared and thermal gravimetric analysis (TG / DTG).The study was conducted on the thermogravimetric behavior of sunflower oil on the mesoporous catalyst cited. Activation energy, conversion, and oil degradation as a function of temperature were estimated based on the integral curves of thermogravimetric analysis and the kinetic method of Vyazovkin. The mesoporous material Al-MCM-41 showed one-dimensional hexagonal formation. The study of the kinetic behavior of sunflower oil with the catalyst showed a lower activation energy against the activation energy of pure sunflower oil. Two liquid fractions of sunflower oil were obtained, both in thermal and thermocatalytic pyrolisis. The first fraction obtained was called bio-oil and the second fraction obtained was called acid fraction. The acid fraction collected, in thermal and thermocatalytic pyrolisis, showed very high level of acidity, which is why it was called acid fraction. The first fraction was collected bio-called because it presented results in the range similar to petroleum diesel

Caracterização de superfícies de titânio modificado por oxidação à plasma

Recent years have seen a significant growth in surface modifications in titanium implants, resulting in shorter healing times in regions with low bone density. Among the different techniques, subtraction by chemical agents to increase oxidation has been applied for surface treatment of dental implants. However, this technique is generally unable to remove undesirable oxides, formed spontaneously during machining of titanium parts, raising costs due to additional decontamination stages. In order to solve this problem, the present study used plasma as an energy source to both remove these oxides and oxidize the titanium surface. In this respect, Ti disks were treated by hollow cathode discharge, using a variable DC power supply and vacuum system. Samples were previously submitted to a cleaning process using an atmosphere of Ar, H2 and a mixture of both, for 20 and 60 min. The most efficient cleaning condition was used for oxidation in a mixture of argon (60%) and oxygen (40%) until reaching a pressure of 2.2 mbar for 60 min at 500°C. Surfaces were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), atomic force microscopy (AFM), adhesion and cell proliferation. SEM showed less cell spreading and a larger number of projections orfilopodia in the treated samples compared to the control sample. AFM revealed surface defects in the treated samples, with varied geometry between peaks and valleys. Biological assays showed no significant difference in cell adhesion between treated surfaces and the control. With respect to cell proliferation, the treated surface exhibited improved performance when compared to the control sample. We concluded that the process was efficient in removing primary oxides as well as in oxidizing titanium surfaces

Políticas públicas para agricultura familiar: uma avaliação sobre a correspondência do paa e do PRONAF nos territórios da cidadania do Rio Grande do Norte - 2008 a 2010.

Family farming has been considered as the new axis of rural development in the country, the focus of several public policies, especially the National Program for Strengthening Family Agriculture - PRONAF and Food Purchase Program - PAA. PRONAF was created with the aim of providing credit to farmers, while the PAA to support family farmers through the purchase of its production. In this context, the objective of this study is to analyze the correspondence of these two public policies for family farming, in the Territories of Citizenship of the state of Rio Grande do Norte, between the years 2008 to 2010. In the methodology, the analysis was performed by comparing the distributions of the two programs in the territories of citizenship status. There were also statistical tests of differences in proportions, and Spearman correlations, and estimated a logit regression model, in order to measure the probability of a farmer participating in the PAA is associated with one of the modes of PRONAF. The data used were obtained from the National and Supply - CONAB at the Institute of Technical Assistance and Rural Extension - EMATER, and the Ministry of Agrarian Development - MDA. Among the key findings was noted that policies were associated with a direct, but low in the districts of the Territories of Citizenship. And that, in the years 2008 and 2009, only in the territories of Mato Grande, Alto Oeste and Seridó, the actions of PAA and PRONAF had direct and significant correlations. It was found that in most of the territories, policies are performed randomly, ie that both have no correlation to each other. The estimates of the logit model showed that the chance of a family farmer, the PAA participant, receive credits PRONAF A, is higher in the territory of Mato Grande, and would have a chance to fall in PRONAF B in all areas surveyed. Moreover, farmers in the territories of the Assu-Mossoró, Sertão of Apodi, Seridó and Alto Oeste, participating in the PAA would be more likely to receive credits PRONAF C, reflecting thus the family farm more consolidated these territories

A recepção da criança com deficiência intelectual ao texto literário na educação infantil

The focus of this thesis is children's reception to literary texts starting from literary livelihood in an inclusive literary context, looking for the possible evidences that are present in the construction as reader/hearing of literature. Based on a study case, we search the ways of participation of a child (girl) with intellectual deficiency in situations of offering and reception of literary texts, looking for the understanding and explication of some aspects of her processing and the building up of an initial reader. The data were taken starting from observations in moments of reading and story-telling in the period from November to December/2008 and May to June/2009 in a public school of children education, in Natal- Brazil, in which there was a registered student showing intellectual deficiency associated to Down syndrome. As research tools we used: field diary, interview scripts and video recordings. The analyses were based on research from Amarilha (2001, 2006a, 2006b), Bettelheim (2007), Coelho (2008), Iser (1996), Jauss (1979, 1994), Luria (1990a, 1990b), Vygotsky (1991, 1993), Wallon (2007, 2008) amongst others. The research showed that although expressing little verbalization and limited levels of attention, body attitudes, movements and talks of the child under investigation, denounced engagement and rendition to the sonority of the texts shared. These data gives us traces that, under a mediating action, the child with intellectual limitation can turn into a reader/hearing subject of literature, developing a sensitive and a selective attitude towards the literary text. Amongst other aspects, we identified that (1) a conception of deficiency present through the school that recognizes his/her potential of developing and learning (2) the situation of sharing, that favours a relation with the texts through the other, and (3) the relevance of orality providing the semantic paths that help the child in the building up of meaning, presenting themselves as fundamental to her/his viewing of the literary text, and, therefore, the formation of the reader. Thus, recognizing her/his capacity and possibilities, we think it is important to guarantee to the child with intellectual deficiency, a space towards interaction with the fictional text in which the child can learn and live its ludic and interactive character, to enjoy its hearing abilities, benefiting, then, from the aesthetic experience lived, mainly, in collective situations mediated through the more experient reader and shared with her/his different pairs. The research shows yet that, looking after conditions that guarantee a comfortable environment to the story hearings in the classrooms that focus on children education, being aware of a selection and the prosody of stories, the didactic contract, the attention to individual reactions, enlarge the possibility of any child deficient or not to enjoy her/himself as reader/ hearing subject of literature, engaged in its richness and magic

Monitoramento em tempo real de processos fermentativos por espectroscopia no infravermelho próximo (NIRS)

A chemical process optimization and control is strongly correlated with the quantity of information can be obtained from the system. In biotechnological processes, where the transforming agent is a cell, many variables can interfere in the process, leading to changes in the microorganism metabolism and affecting the quantity and quality of final product. Therefore, the continuously monitoring of the variables that interfere in the bioprocess, is crucial to be able to act on certain variables of the system, keeping it under desirable operational conditions and control. In general, during a fermentation process, the analysis of important parameters such as substrate, product and cells concentration, is done off-line, requiring sampling, pretreatment and analytical procedures. Therefore, this steps require a significant run time and the use of high purity chemical reagents to be done. In order to implement a real time monitoring system for a benchtop bioreactor, these study was conducted in two steps: (i) The development of a software that presents a communication interface between bioreactor and computer based on data acquisition and process variables data recording, that are pH, temperature, dissolved oxygen, level, foam level, agitation frequency and the input setpoints of the operational parameters of the bioreactor control unit; (ii) The development of an analytical method using near-infrared spectroscopy (NIRS) in order to enable substrate, products and cells concentration monitoring during a fermentation process for ethanol production using the yeast Saccharomyces cerevisiae. Three fermentation runs were conducted (F1, F2 and F3) that were monitored by NIRS and subsequent sampling for analytical characterization. The data obtained were used for calibration and validation, where pre-treatments combined or not with smoothing filters were applied to spectrum data. The most satisfactory results were obtained when the calibration models were constructed from real samples of culture medium removed from the fermentation assays F1, F2 and F3, showing that the analytical method based on NIRS can be used as a fast and effective method to quantify cells, substrate and products concentration what enables the implementation of insitu real time monitoring of fermentation processes

Mariana , Pai contra mãe e O caso da vara : escravidão e chão histórico em Machado de Assis

Machado de Assis understood his time and brought his perception of Brazilian society in the 19th century, with its multiple aspects economy, politics, culture, amongst others - to the texts he wrote. Through the tensions lived in his novels and short stories, Machado displays Brazilian social reality and the changes it had been undergoing. Mariana and Pai contra mãe show the crisis of the slavery system, the relation of dependency, the treatment given to the captives and the lack of coherence of a country that intended to adopt Liberalism as an ideology, but which kept on living under the shadow of slavery and its consequences. A country where the priorities were given to the landlords, owners of slaves, in protection of their interests. O caso da vara tells about how the crias da casa little black girls who lived in the household and learned how to make spool embroidery were treated. What were the punishments for desobedience and how they were levelled out, how should be the behaviour of a child who lived as a social outcast. Thus, this paper aims at playing a game of mirrors between History and fiction. Not only to play it, but to analyze how Machado deals with the reflections of 19th century Brazil on his short stories

Inês de Castro no romance contemporâneo português

Ines de Castro is a theme in literature from the fourteenth century. The historical fact of his death, in 1355, became a landmark in the history of Portugal and, since then, several literary texts from various genres, have dealt with this theme, this made the couple Pedro and Ines a myth of love passion, of love beyond the barriers of death, like Tristan and Isolde, Romeo and Juliet, Abelard and Heloise. The literary myth - or any picture that mythologize literature - is always prepared before culturally and works in the same way that so many others, this is, as an element of cultural identity, either collectively or individually, making it also a feature poetic. Thereby, is an archetype confirmed through time and eventually reveals a series of webs of the human psyche. Ines de Castro became the Portuguese myth of eternal love: she became queen after your dead. The persistence of the myth makes the love story of Pedro and Ines continue to produce texts of various literary genres. This study examines six contemporary historical novels, to show that the way actually this kind o novel does a new formulacion of Pedro e Ines mythical, because now it s different view likes the victim in Os lusiadas and other texts from the past. Collaborate to this news relacions between history and literature and a novelist's new stance in relation to historical facts that relate like reffering to novel. The intention is to show, through the novels chosen now Ines de Castro have different profiles than it had before in tradicional historic novels from the period of Romanticism and New Romanticism. Authored by Agustina Bessa-Luís, João Aguiar, António Cândido Franco, Seomara da Veiga Ferreira and Luis Rosa, the six novels studied show the circularity cultural of inesian myth showing this new character of the new person Ines in the contemporany historical novel

A produção do gênero monografia em discursos de professores e alunos do curso de letras

A current worry in the teaching process at the university these days is text production process and genres produced there, especially those kind of writing that is concerned to course conclusion such as monograph, dissertation and thesis. From this perspective and considering our aims at understanding discursive process involved in the production of monograph genre at the university we want to analyze teachers and students discourses about the productive process of monograph in Letras Course, considering the guide, writing and specific aspects of that genre. To get the aims, we took as background theory the studies by Bakhtin linked to Utterance Linguistics with foundation concepts in Discourse Text Analysis by Adam (2010), and finally the studies developed about text production at college. This way, this work is based on a qualitative research and in data ethnographic procedures, they are: the observation in locus, as well as the application of questionnaires with opened questions to ten students and six teachers from Letras Course. The discourse analysis from the subjects reveal us that: i) the monograph production and the guidance are form of act by language, that need take into account in its development: students free chose as a principle in writing monograph, as well as a wide involvement between the teacher and the student in a sense to turn the writing better, among other aspects; (ii) there is a need to articulate monograph project and the text produced, considering that the guide process comes from a project written before; (iii) there are a number of role to discourses by teachers and students to the function of student and guide teacher, in a way that both can see the same assumptions in teachers and students discourses; (iv) teacher s and students discourses show that they assume the utterance responsibilities by the content of utterances proposed, they also show the voice from methodology guidebooks to monograph texts. So, we conclude that this research has some contributions to teach writing production at the university, especially to monograph in the ending of the courses. It can also be helpful in developing research in this area, mainly at the question about guide final works at college