Estudo da síntese e propriedade magnética de ferritas de manganês/cobalto dopadas com níquel

For the chemical method of synthesis of co-precipitation were produced ferrite powders manganese-cobalt equal stoichiometric formula Mn (1-x) Co (x) Fe2O4, for 0 < x < 1, first reagent element using as the hydroxide ammonium and second time using sodium hydroxide. The obtained powders were calcined at 400 ° C, 650 ° C, 900 ° C and 1150 ° C in a conventional oven type furnace with an air atmosphere for a period of 240 minutes. Other samples were calcined at a temperature of 900 ° C in a controlled atmosphere of argon, to evaluate the possible influence of the atmosphere on the final results the structure and morphology. The samples were also calcined in a microwave oven at 400 ° C and 650 ° C for a period of 45 minutes possible to evaluate the performance of this type of heat treatment furnace. It was successfully tested the ability of this group include isomorphic ferrite with the inclusion of nickel cations in order to evaluate the occurrence of disorder in the crystalline structures and their changes in magnetic characteristics.To identify the structural, morphological, chemical composition and proportions, as well as their magnetic characteristics were performed characterization tests of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDX), thermogravimetric (TG), vibrating sample magnetometry (MAV) and Mössbauer spectroscopy. These tests revealed the occurrence of distortion in the crystal lattice, changes in magnetic response, occurrence of nanosized particles and superparamagnetism

Transmissão de Radiação Ultravioleta Através do Pelame e da Epiderme de Bovinos

A transmissão de radiação ultravioleta de comprimentos de onda entre 250 e 360 nm através do pelame e da epiderme de bovinos foi determinada em laboratório, usando-se amostras de couro de animais recém-abatidos. A quantidade de radiação transmitida através do pelame depende da coloração e também das características estruturais do pelame (espessura da capa; comprimento, diâmetro, número e inclinação dos pêlos), pelas quais é definido o trajeto médio de um fóton pela massa de pêlos (L). A maior transmissão é proporcionada por pelames brancos com altos valores de L, ao passo que pelames negros em geral apresentam transmissão nula ou muito baixa. Quanto menos pigmentada a epiderme, maior a transmissão de radiação através da sua superfície. A melhor proteção é proporcionada por pelames negros com baixo valor de L sobre epiderme igualmente negra, mas em vista do aquecimento causado pela absorção de radiação térmica (em vacas Holandesas a temperatura das malhas negras atinge 44,1ºC ao mesmo tempo em que a das malhas brancas é 37,7ºC), a combinação ideal para ambientes tropicais é um pelame branco com baixo valor de L sobre epiderme negra, uma combinação dificilmente encontrada em animais de raças européias. Uma alternativa seria um pelame negro com um baixo valor de L. Animais vermelhos apresentam alta transmissão de radiação UV através da epiderme e do pelame, sendo desaconselhados para ambientes tropicais. Entretanto, foi observada uma vaca Holandesa com áreas isoladas de epiderme negra coberta com pelame branco, o que pode trazer perspectivas para uma seleção para combinações mais adequadas de epiderme e pelame em bovinos de raças européias.

O hipertexto eletrônico de meio ambiente : estratégias de leitura e navegação

The incorporation of computing in class instigate the use of the Internet and websites as a content support in the teaching/leaning process. This kind of practice had challenged the students to read through eletronic hypertextual means. In that way, we re trying to undestand which strategies of reading and navigation the students of the second and third grade of highschool levels are using when reading electronic hypertexts from the www.ambientebrasil.com.br website. The research took place in the Escola Estadual Jerônimo Rosado in Mossoró RN. Our theoretical base was estructured on the digital Technology (electronic hypertext estructure and it s navigation modes), in applied linguistics (act of reading) and in cognition (interaction of the reader with the text and the use of reading strategies in the virtual computing enviroment). The applied methodology was the case analysis which was developed with the reunion of collected data through qualitative reseach questionaries, direct observations and video recording sessions. The research demonstrates that reader s ability in the act of navigating on virtual sites activates his/her reading strategies. Also shows how the semantic architecture of the hyperlinks can interfere directly over the strategies of reading and navigation in specific websites. Our research also intend to demonstrate that the student use his strategies of linear text reading when are not accustomed to use the reading through websites in a regular basis. The investigation concludes observing that the amount of hypertexts per pages and the inappropriate use of the multimedia elements were harmful to the reading fluency

Uso de ferramentas por macacos-prego em manguezais

The present study discusses the geographical distribution and the context on the occupation of mangrove swamp areas by capuchin monkeys. In addition, we assess how the dispersion to the mangrove allowed the exploration of different food items, permitting the development of predation by ambush and the use of cracking tools. From 2004 to 2008 we surveyed the main estuaries of Brazilian Amazon coast, from northeastern state of Pará to the eastern boundary of the state of Maranhão, and recorded the presence of two species of capuchin monkeys in the mangrove forest areas. Cebus apella has been widely distributed in the mangrove at the estuaries examined (excluding C. libidinosus areas). Its presence is often related to Amazon forest remnants in the neighbourhood of the mangrove swamps and thus it is possible that some groups live in both kinds of habitats. However, we recorded some populations restricted only to mangrove swamp surrounded by open areas. On the other hand, Cebus libidinosus had a distribution more restricted and isolated in mangroves. Its pattern of habitat use is consistent with geographic distribution in mangrove patches. It seems that the possible contact zone previously proposed in the literature for that two species has no evident barriers in the mangrove. Furthermore, we record cracking sites and systematic observations on the tool use, carnivory and predation by ambush in Cebus libidinosus from 2006 to 2008. Cebus libidinosus is the only Neotropical primate species in which the tool use has been systematically recorded in nature. However all previous studies had been obtained is open areas (Cerrado and Caatinga). Thus, the present study is first one to report that behaviour in forested habitats in which the tool use to cracking by capuchin monkeys is associated with the consumption of meat. In the Caatinga and Cerrado, food shortages and terrestriality has been proposed by different authors to explain the evolution of tool use in primates. Here, we analyzed the relative contribution of these two variables as selective pressures for the tool use by capuchin monkeys in the mangrove forests, an ecological scenario in which food resources is available around the year and terrestriality is limited by structural habitat features, as the presence of stilt roots and muddy soil

Efeito da degradação ambiental nas propriedades de cisalhamento de compósitos PPS/fibra de carbono

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Pistas orgânicas: uma atividade lúdica para o ensino das funções orgânicas

Educational games can work as a complementary tool in teaching and learning chemistry, playing an important role in the development of the students cognitive structures, familiarizing them with certain conceptual content, which may arouse interest in the study of such content. In this work, we made an analysis of organic chemistry textbooks recommended by Programa Nacional do Livro Didático 2012, for high school students in order to verify the existence of methodological proposals using educational games. From this analysis, we proposed an educational game to be developed for students on 3º year of high medium and undergraduate chemistry, that are in 1º semester of the course, which is constituted of a tray and 48 letters, which work various concepts concerning organic functions, such as: structural characteristics, physical properties, chemical and properties diverse of the compounds used for the confection of the letters. The game was applied to a class degree in chemistry, period 2012.1 to a Federal Education of Rio Grande do Norte and a group of students of the 3rd year of the state schools of Rio Grande do Norte, in the period the months of April and May 2012. The analysis of the performance of the game proposed was made using visual observations, photographic records and testimonials of students who participated in the games. The instrument used for the data collection was the student questionnaire, which was similar for both groups, differing only in the amount of questions, because one of them had one more question. During application of the game it was observed that it constitutes a dynamic strategy in the teaching and learning of chemistry concepts, given that students actively participated in the classes as well, demonstrated more motivation in the construction of concepts, furthermore, it was possible to observe evidence of other possibilities of the game. This could be verified through visual observations and testimonials at the end of each game, by reading the answers to the questionnaires

As Faces e os Disfaces da Informalidade no Capitalismo Conteporâneo: Um Estudo do Comércio de Rua em Pau dos Ferros/RN

This paper discusses the expression of informality in contemporary capitalism. Thematic of relevance to the analysis of the reality of work today and the logic that moves the capital, its real presence in the lives of individuals. The street trading of Pau dos Ferros town, popularly known as "street market" was chosen as the search space. The main objective is to seize and examine the articulations and logic, present in the configuration of the street trading of this city, located in the state of Rio Grande do Norte, explaining the functionality of informality for capitalist accumulation, but also for the reproduction of segments of the working class. Our analysis is based in the perspective of totality, trying to grasp the historical determinations of the phenomenon in focus. It includes the analysis of the mechanisms used by the capital to reproduce itself in the current historical context, which has been implicated in the composition of the labor markets of different countries and in various forms of exploitation to which workers in general are subject. It also means discussing the development of capitalism in Brazil, the logic that permeates its dependence, and especially the use of over-exploitation of labor, as a lever for internal accumulation. The course of investigation consisted of theoretical research to form the basis of theoretical and methodological analysis and to outline the context in which our research object is inserted, and field research conducted in two phases: systematic observation, which allowed to map traders features and the infrastructure of commerce, and the conduction of interviews with key informants. The material collected was scrutinized according to analytical scheme inspired by the content analysis. Among the main considerations developed from the research process we include: the street trading of Pau dos Ferros remains shrouded in the majority sale of agricultural products, this demonstrates the structural characteristics of the region. However, the supply of this product is no longer restricted to the excess of small local producers. The presence of the dealer changed the distribution of the product, streamlining it. In parallel, business practices are developed, practices in which traded goods (industrial) reflect the moment of capitalist restoration, a larger business network. The reflections also made it possible to show that street trading follows developing on the basis of informal work, which gains functionality to the system, as it is configured as a space commonly used to drain part of the production, of industries (clothing/shoes), especially if the distribution is considered as an essential element of the complex process that aims at capital appreciation. This activity has been functioning as a place of employment and income generation for the subjects who are away from formal employment, masking, this way, unemployment, moreover, they allow them to continue as consumers. Such expressions reflect the ability and the logic of capital to expand and aggregate into so many realities. It is underway today, the logic that has led many workers to join the project of domination of capital, by the illusory chance to become capitalists. The aim has been to turn the subject into a consumer and the worker an enterprising

Análise espectroscópica da estrela HD 150050: uma nova estrela gigante rica em lítio

Conselho Nacional de Desenvolvimento Científico e Tecnológico

Cyclodextrin glycosyltransferase production by new Bacillus sp. strains isolated from brazilian soil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production of thermostable glucoamylase by newly isolated Aspergillus flavus A 1.1 and Thermomyces lanuginosus A 13.37

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Production and characterization of glucoamylase from fungus Aspergillus awamori expressed in yeast Saccharomyces cerevisiae using different carbon sources

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of enzymatic hydrolysis on some physicochemical properties of root and tuber granular starches

A hidrólise enzimática do amido pode fornecer informações importantes sobre sua estrutura granular. Amidos de mandioca, batata-doce, mandioquinha-salsa e batata foram hidrolisados por α-amilase bacteriana a 37 °C durante 48 horas, e algumas propriedades físico-químicas dos resíduos da hidrólise foram determinadas. O amido de mandioca foi o mais suscetível à enzima com 20,9% de hidrólise, enquanto o amido de batata foi o mais resistente com 5,9%. O tamanho médio dos grânulos variou de 10,8 a 23,4 μm para os amidos de mandioquinha-salsa e batata, respectivamente. Amidos de mandioca e batata-doce apresentaram um padrão de difração de raio-X tipo A, enquanto os amidos de mandioquinha-salsa e batata mostraram padrão tipo B. Todos os amidos nativos mostraram superfície granular lisa e, após hidrólise, os amidos de mandioca, batata-doce e mandioquinha-salsa mostraram alguns grânulos bastante degradados, enquanto o amido de batata apresentou sutil sinal de degradação. O teor de amilose dos amidos diminuiu com a hidrólise para os amidos de mandioca, batata-doce e mandioquinha-salsa, permanecendo inalterado para o amido de batata. Como esperado, a viscosidade intrínseca e as propriedades de pasta diminuíram para todos os amidos hidrolisados. Não houve diferença significativa entre as propriedades térmicas dos amidos nativos e hidrolisados. Estes resultados sugeriram que a hidrólise ocorreu nas áreas cristalinas e amorfas dos grânulos. O padrão de difração do tipo B e o grande tamanho dos grânulos do amido de batata podem ter contribuído para a maior resistência deste amido à hidrólise.

Effect of addition of different hydrocolloids on pasting, thermal, and rheological properties of cassava starch

Amidos e gomas são hidrocoloides frequentemente usados em sistemas alimentícios com a finalidade de fornecer textura, umidade e mobilidade de água. A interação amido-goma em sistemas alimentícios pode alterar o inchamento do grânulo de amido e as suas propriedades de gelatinização e reológicas. Neste trabalho, o efeito da adição de goma xantana (GX), carboximetilcelulose sódica (CMC) e carragena (CAR) nas concentrações de 0,15, 0,25, 0,35 e 0,45% (p/v) sobre as propriedades de pasta, térmicas e reológicas do amido de mandioca foi estudado. O Poder de inchamento (PI) e a Microscopia Eletrônica de Varredura (MEV) dos géis de amido também foram avaliados. Os resultados obtidos mostraram que a GX apresentou forte interação com o amido, penetrando entre os grânulos e provocando aumento das viscosidades de pasta, PI, G' e G, e redução da retrogradação do amido; CMCS aumentou as viscosidades de pasta, PI, G' e G das misturas, principalmente em função da sua maior capacidade de reter água, e não por causa da interação com o amido; CAR não modificou qualquer das propriedades do amido, porque não houve nenhuma interação entre essa goma e o amido de mandioca nas concentrações usadas.

Avaliações ultra-sonográfica, macroscópica e histológica da biopsia testicular em ovinos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Anatomia comparada do pulvino, pecíolo e raque de Pterodon pubescens Benth. (Fabaceae - Faboideae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)