Avaliação do potencial antiinflamatório, anticoagulante e hemorrágico de heparinóides presentes em "Artemia franciscana"

Heparan sulfate (HS) and Heparin (Hep) glycosaminoglycans (GAGs) are heterogeneous and highly charged polysaccharides. HS is structurally related to Hep but is much less substituted with sulfo groups than heparin and has a more varied structure (or sequence). Because of structural similiarities between these two polymers, they have been described together as heparinoids . Both chains bind a variety of proteins and mediate various physiologically important processes including, blood coagulation, cell adhesion and growth factor regulation. Heparinoids with structural characteristics similar to these described from HS and/or Hep from mammalian tissues have been isolated from different species of invertebrates, although only a few heparinoids from unusual sources have been characterized. The present study describes the presence of unusual heparinoids population from Artemia franciscana, isolated after proteolysis and fractionation by ion exchange resin and named, F-3.0M. The study model in vivo were hemostasis (rat tail scarification) and inflamatoty activity. The tests in vitro were used for coagulations assays (PT and APTT). The analyse of the heparinoids eluted with 3,0M NaCl showed electrophoretic migration in different buffer systems a single band with a behaviour intermediate between those of mammalian HEP and HS. The main products obtained from Artemia heparinoids after enzymatic degradation with heparitinases I and II from F. heparinum were N-sulphated disaccharides (∆U-GlcNS,6S/ ∆U,2S-GlcNS and ∆U-GlcNS) and N-acetylated disaccharides (∆U, GlcNAc). This heparinoid had a lower hemorrhagic effect (400μg/ml) when compared to unfractiionated heparins(25μg/ml).The results also suggest a negligible APTT activity of this heparinoid (62.2s). No action was observed on PT indicating that F-3.0M haven t action on the extrinsic pathway. The results showed that the fraction F- 3.0M have inhibitory effect on migration of leukocytes, 64.5% in the concentration of 10 μg/ml (P<0.001). The search for new heparin and/or heparan sulphates analogs devoid of anticoagulant activity is an atractive alternative and may open up a wide variety of new therapeutic applications

Estudos comparativos do ciclo de regeneração de diferentes tipos de silicoaluminofosfatos

Different types of heterogeneous catalysts of the silicoaluminophosphate type, (SAPO-5, SAPO-11, SAPO-31, SAPO-34 and SAPO-41), molecular sieves with a: AFI, AEL, ATO, CHA and AFO structure, respectively, were synthesized through the hydrothermal method. Using sources such as hydrated alumina (pseudobohemita), phosphoric acid, silica gel, water, as well as, different types of organic structural templates, such as: cetyltrimethylammonium bromide (CTMABr), di-isopropylamine (DIPA), di-n- propylamine (DNPA) and tetraethylammonium hydroxide (TEOS), for the respective samples. During the preparation of the silicoaluminophosphates, the crystallization process of the samples occurred at a temperature of approximately 200 ° C, ranging through periods of 18-72 h, when it was possible to obtain pure phases for the SAPOs. The materials were furthermore washed with deionized water, dried and calcined to remove the molecules of the templates. Subsequently the samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), absorption spectroscopy in the infrared region (FT-IR), specific surface area and thermal analysis via TG/DTG. The acidic properties were determined using adsorption of n-butylamine followed by programmed termodessorption. These methods revealed that the SAPO samples showed a typically weak to moderate acidity. However, a small amount of strong acid sites was also detected. The deactivation of the catalysts was conducted by artificially coking the samples, followed by n-hexane cracking reactions in a fixed bed with a continuous flow micro-reactor coupled on line to a gas chromatograph. The main products obtained were: ethane, propane, isobutene, n-butane, n-pentane and isopentane. The Vyazovkin (model-free) kinetics method was used to determine the catalysts regeneration and removal of the coke

Investigação das alterações citogenéticas em pacientes pediátricos com leucemia linfóide aguda do Rio Grande do Norte

Leukemia is a heterogeneous group of hematologic malignancies that result from partial or total transformation of the blast cells. The Acute Lymphoblastic Leukemia (ALL) is the most common malignancy in childhood, especially in male, Caucasian children younger than 14 years. Several criteria are adopted to classify ALL, including the cell morphology, cytochemistry, immunophenotyping and cytogenetic analysis. Cytogenetic studies allow a more detailed analysis to detect chromosomal abnormalities of leukemic cells. These modifications will determine the diagnosis, classification, stage characterization, remission assessment and prognosis. In this study were evaluated 30 patients, aged from four months to seventeen years, of both sexes and various ethnicities. The age distribution showed that 67% of patients had between one and ten years (with mean age of XX years old), the most prevalent ethnic was Caucasian (50%) and 57% were males. According to immunophenotype, 93% of patients had B-cells progenitor ALL and 7% early lineage T. Considering the total studied population, the most frequent medical findings were lymphadenopathy (37%), hepatomegaly (77%) and splenomegaly (70%), where one patient could present more than one of these medical findings. Regarding the CBC, the majority of patients had hemoglobin below 10 g / dl (73%), leukocyte count less than 10.000/μL (60%) and platelet count below 150.000/μL (83%). Chromosomal abnormalities were observed in 64% of all patients, where hyperdiploidy was the most common numerical change (67%), followed by hypodiploid (33%). All these data are in agreement with the literature. Moreover, complexes structural and/or number changes not yet described in literature were observed, which indicated poor prognosis. Finally, we concluded that this study demonstrated the importance of cytogenetic study in the diagnosis and identification of prognostic factors in pediatric patients with ALL in Rio Grande do Norte. The results obtained in this study are extremely useful and emphasizes that surveys of this nature must be conducted more frequently in our state

A escola rural e o desafio da docência em salas multisseriadas: o caso do seridó norteriograndense

Uno de los principales desafíos colocados a la educación del medio rural está relacionado a la enseñanza de las escuelas rurales con salas multifacéticas. Estas comprehenden alumnos de diferentes comunidades, series, edades, aprendizaje y niveles de conocimientos. Son cursos heterogéneos, que tienen como característica central la diversidad. En muchas regiones rurales de Brasil, la educación escolar es organizada en cursos multifacéticos debido a las grandes distancias entre las comunidades y el bajo número de alumnos en cada serie/año. Es común encontrar a los que están en fase de alfabetización estudiando con quien ya sabe leer y escribir - y todos sobre la orientación de apenas una profesora, que necesita enseñar a partir del contexto y la cultura local. El punto principal a ser tratado en este estudio está relacionado a las prácticas ejercidas en la acción educativa de las profesoras que actúan en escuelas rurales con salas multifacéticas de la región del Seridó do Rio Grande do Norte, precisamente en los municipios de Caicó, Jardim do Seridó y Ouro Branco. Creemos que este es uno de los puntos centrales en la discusión sobre la organización de la educación en el medio rural con fuertes implicaciones para el atendimiento cualificado de la población en condiciones de escolaridad de ese medio. Las contribuciones de Werthein y Bordenave, Calazans, Paiva, Ramalho, Therrien y Damasceno, Leite, Passador, Molina, Arroyo, Nascimento, Hage, además de documentos oficiales del MEC, como cuadernos SECAD, Ley de Directrices y Bases de la Educación Nacional, Directrices Operacionales para la Implantación de la Enseñanza Básica de 9 (nove) años, Proyecto Base del Programa Escuela Activa, entre otros, fundamentaron el análisis sobre la escuela rural y el desafío de la docencia en salas multifacéticas en el contexto del Seridó norteriograndense. El estudio envolvió 24 (veinticuatro) profesoras y 06 (seis) profesionales de la educación que desempeñan sus funciones en los Centros Municipales de Enseñanza Rural (CMER). Los instrumentos de investigación empleados fueron cuestionarios y observaciones aplicados para responder a las siguientes preguntas: ¿cómo se estructura la escuela rural con salas multifacéticas? ¿Cómo las profesoras se posicionan sobre su trabajo en salas multifacéticas esto es, como las concibe en el contexto de la educación rural del Seridó? ¿Qué opinan sobre la formación recibida para actuar en salas multifacéticas? Las profesoras y los/las profesionales de los CMER poseen en general formación superior en pedagogía, sin embargo, presentan limitaciones delante de las situaciones surgidas en el día a día de la sala de clases. El estudio revela que son las deficiencias de las políticas sociales y educacionales de formación docente, el bajo apoyo didáctico-pedagógico, reforzadas por la ausencia de un plano de carrera que dignifique el trabajo docente en ese medio, que generan limitaciones en el desarrollo profesional del magisterio rural, claramente junto a los docentes que actúan en salas multifacéticas en los municipios investigados

Enraizamento de estacas herbáceas de quatro clones de umezeiro (Prunus mume Sieb. et Zucc.) durante o inverno ameno, em Jaboticabal-SP

Estudos realizados no Brasil com o umezeiro (Prunus mume Sieb. et Zucc.) relatam promissoras perspectivas de utilização desta espécie como porta-enxerto para pessegueiro e nectarineira, em função de sua rusticidade, adaptação ao inverno brando, compatibilidade com Prunus persica, redução do vigor das plantas e melhoria da qualidade dos frutos. Entretanto, em função da propagação por sementes, tem sido observadas diferenças de vigor entre as plantas, resultando em pomares muito heterogêneos. Assim, o presente estudo teve por objetivo estudar o enraizamento de estacas herbáceas de quatro clones de umezeiro (Clones 02, 05, 10 e 15) durante o inverno ameno, em Jaboticabal-SP. O experimento foi conduzido entre os meses de junho e agosto, sendo avaliado aos 70 dias após a estaquia. Pelos resultados obtidos, foi possível concluir que é viável a propagação dos clones estudados por enraizamento de estacas herbáceas durante o inverno. Foram observadas diferenças entre os clones quanto à porcentagem de enraizamento, porcentagem de estacas com calo, número e comprimento das raízes. No conjunto das variáveis analisadas, os melhores resultados foram obtidos com os Clones 10 e 15.

Metodologia para adaptação de microarquiteturas microprogramadas soft-core à uma ISA padrão: estudo do impacto sobre a complexidade de hardware para o padrão MIPS

In academia, it is common to create didactic processors, facing practical disciplines in the area of Hardware Computer and can be used as subjects in software platforms, operating systems and compilers. Often, these processors are described without ISA standard, which requires the creation of compilers and other basic software to provide the hardware / software interface and hinder their integration with other processors and devices. Using reconfigurable devices described in a HDL language allows the creation or modification of any microarchitecture component, leading to alteration of the functional units of data path processor as well as the state machine that implements the control unit even as new needs arise. In particular, processors RISP enable modification of machine instructions, allowing entering or modifying instructions, and may even adapt to a new architecture. This work, as the object of study addressing educational soft-core processors described in VHDL, from a proposed methodology and its application on two processors with different complexity levels, shows that it s possible to tailor processors for a standard ISA without causing an increase in the level hardware complexity, ie without significant increase in chip area, while its level of performance in the application execution remains unchanged or is enhanced. The implementations also allow us to say that besides being possible to replace the architecture of a processor without changing its organization, RISP processor can switch between different instruction sets, which can be expanded to toggle between different ISAs, allowing a single processor become adaptive hybrid architecture, which can be used in embedded systems and heterogeneous multiprocessor environments

Aplicação de sistemas multi-classificadores no diagnóstico de falhas em motores de indução trifásicos

Equipment maintenance is the major cost factor in industrial plants, it is very important the development of fault predict techniques. Three-phase induction motors are key electrical equipments used in industrial applications mainly because presents low cost and large robustness, however, it isn t protected from other fault types such as shorted winding and broken bars. Several acquisition ways, processing and signal analysis are applied to improve its diagnosis. More efficient techniques use current sensors and its signature analysis. In this dissertation, starting of these sensors, it is to make signal analysis through Park s vector that provides a good visualization capability. Faults data acquisition is an arduous task; in this way, it is developed a methodology for data base construction. Park s transformer is applied into stationary reference for machine modeling of the machine s differential equations solution. Faults detection needs a detailed analysis of variables and its influences that becomes the diagnosis more complex. The tasks of pattern recognition allow that systems are automatically generated, based in patterns and data concepts, in the majority cases undetectable for specialists, helping decision tasks. Classifiers algorithms with diverse learning paradigms: k-Neighborhood, Neural Networks, Decision Trees and Naïves Bayes are used to patterns recognition of machines faults. Multi-classifier systems are used to improve classification errors. It inspected the algorithms homogeneous: Bagging and Boosting and heterogeneous: Vote, Stacking and Stacking C. Results present the effectiveness of constructed model to faults modeling, such as the possibility of using multi-classifiers algorithm on faults classification

Modelagem em SystemC-AMS de uma plataforma compatível com o sistema de coleta de dados brasileiro

This work presents simulation results of an identification platform compatible with the INPE Brazilian Data Collection System, modeled with SystemC-AMS. SystemC-AMS that is a library of C++ classes dedicated to the simulation of heterogeneous systems, offering a powerful resource to describe models in digital, analog and RF domains, as well as mechanical and optic. The designed model was divided in four parts. The first block takes into account the satellite s orbit, necessary to correctly model the propagation channel, including Doppler effect, attenuation and thermal noise. The identification block detects the satellite presence. It is composed by low noise amplifier, band pass filter, power detector and logic comparator. The controller block is responsible for enabling the RF transmitter when the presence of the satellite is detected. The controller was modeled as a Petri net, due to the asynchronous nature of the system. The fourth block is the RF transmitter unit, which performs the modulation of the information in BPSK ±60o. This block is composed by oscillator, mixer, adder and amplifier. The whole system was simulated simultaneously. The results are being used to specify system components and to elaborate testbenchs for design verification

Variabilidade genética em isolados de Curtobacterium flaccumfaciens

A cultura do feijoeiro está sujeita à incidência de várias doenças que acarretam perdas significativas na produção, dentre as quais encontra-se a murcha-de-curtobacterium ou murcha bacteriana, causada por Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff). Atualmente a murcha-de-curtobacterium tem se constituído em um novo problema para a cultura do feijoeiro em várias regiões brasileiras. A resistência genética tem sido o meio mais eficiente no controle da doença, porém a possibilidade da existência de variabilidade genética presente em isolados de Cff, pode ser uma conseqüência maléfica ao melhoramento visando a obtenção de cultivares de feijoeiro resistentes, especialmente na estabilidade e durabilidade da resistência. Neste sentido, o presente trabalho teve como objetivo o estudo da variabilidade genética de 26 isolados de Curtobacterium flaccumfaciens, 20 dos quais provenientes de feijoeiro (Cff), coletados em diferentes regiões do Brasil, quatro provenientes de coleções internacionais (Cff) e dois endofíticos de citros (C. flaccumfaciens). Foram utilizados dois pares de oligonucleotídeos, CffFOR2-CffREV4 e CF4-CF5, avaliando-se na especificidade em reação de PCR, para a caracterização dos 26 isolados. No estudo da variabilidade genética, utilizou-se da técnica rep-PCR e os iniciadores REP, ERIC e BOX. A partir do padrão eletroforético gerado pela amplificação dessas seqüências repetitivas no DNA genômico dos 26 isolados bacterianos, foram realizadas análises pertinentes (UPGMA SM) e obtenção de um dendograma. Considerando-se um índice de similaridade de 75%, os isolados foram distribuídos em quatro grupos distintos. Os isolados de Cff provenientes do Paraná e DF foram separados em grupos diferentes, enquanto que isolados endofíticos de citros não formaram um grupamento distinto dos de feijoeiro. Os isolados procedentes do Estados de São Paulo mostraram-se geneticamente heterogêneos, alguns se agruparam com o isolado de USA, Santa Catarina e de citros, enquanto outros agruparam-se com isolados provenientes da França e Paraná. A avaliação da especificidade dos dois pares de oligonucleotídeos, mostrou que os oligonucleotídeos CffFOR2-CffREV4 detectaram todos os 26 isolados. Os oligonucleotídeos CF4-CF5 apresentaram menor especificidade não detectando dois isolados de Cff de feijoeiro (2928) e (2936) e os isolados endofíticos de citros. Portanto como ferramenta para detecção de Cff em feijoeiro os oligonucleotídeos CffFOR2-CffREV4 revelaram ser os mais indicados.

Avaliação cinética e potencial do Nb2O5 obtido a partir de um complexo de nióbio para formação do oleato de metila através da reação de esterificação do ácido oleico

Among the heterogeneous catalysts materials made from niobium show up as an alternative to meet the demand of catalysts for biodiesel production. This study aims to evaluate the potential of a heterogeneous catalyst derived from a complex of niobium in the reaction of methyl esterification of oleic acid. The catalyst was synthesized after calcination at different temperatures of a niobium complex ((NH4)3[NbO(C2O4)3].H2O) generating a niobium oxide nanostructure with a different commercial niobium oxide used to synthesize the complex. The commercial niobium oxide, the complex niobium and niobium catalyst were characterized by thermogravimetry (TG and DTA), surface area analysis (BET), scanning electron microscopy (SEM) and X-ray diffraction (XRD), showing the catalyst has researched morphological and crystallographic indicating a catalytic potential higher than that of commercial niobium oxide characteristics. Factorial with central composite design point, with three factors (calcination temperature, molar ratio of alcohol/oleic acid and mass percentage of catalyst) was performed. Noting that the optimal experimental point was given by the complex calcination temperature of 600°C, a molar ratio alcohol/oleic acid of 3.007/1 and the catalyst mass percentage of 7.998%, with a conversion of 22.44% oleic acid in methyl oleate to 60 min of reaction. We performed a composite linear and quadratic regression to determine an optimal statistical point of the reaction, the temperature of calcination of the complex at 450°C, the molar ratio of alcohol/oleic acid 3.3408/1 and mass percentage of catalyst of 7.6833% . Kinetic modeling to estimate parameters for heterogeneous catalysis it set well the experimental results with a final conversion of 85.01% with 42.38% of catalyst and without catalyst at 240 min reaction was performed. Allowing to evaluate the catalyst catalytic studied has the potential to be used in biodiesel production

A construção de posicionamento valorativo no cronotopo do PSV- 2008 da UFRN

Située dans le domaine de la Linguistique Appliquée (CELANI, 1998; MOITA LOPES, 2004, 2006, 2009), cette recherche documentaire fait partie d‟une approche qualitative-interprétative qui privilégie une perspective socio-historique (FREITAS, 2002, 2007; ROJO, 2006). Le but principal de ce travail est d‟analyser comment l‟interlocution a lieu dans les lettres argumentatives produites par 10 sujets-énonciateurs ayant participé au processus de sélection du «vestibular» d‟UFRN, appelé ici le chronotope du PSV-2008. Pour cela, les objectifs spécifiques qui guident cette recherche consistent à analyser les modes d‟assimilation du discours de l‟autre par le candidat, à identifier les positions axiologiques résultant des formes du processus interlocutif, et à construire une vision du sujet-énonciateur sur la base des choix de valeurs de l‟énonciateur et des relations espace-temps qui constituent l‟énonciateur et l‟interlocuteur. Quant à la théorie, la recherche est fondée principalement sur la notion de chronotope de Bakhtin une catégorie qui découle de la théorie du roman et problématisée par Amorim (2004) en articulation avec les réflexions théoriques de Geraldi (1997, 1999, 2006), Britto (2006) et Antunes (2005, 2006) sur le processus d‟écriture les relations dialogiques, la responsivité et les voix sociales (BAKHTIN, 1990, 2003, 2008; BAKHTIN/VOLOCHINOV, 2006) qui sont traversées par la conception dialogique du langage. L‟analyse nous a permis d‟identifier, principalement, deux débats dialogiques, dont le premier confronte le candidat à la dissertation et le second, à des interlocuteurs mentionnés dans la proposition. Les sujets ont formulé leurs énoncés sur un ton d‟indignation, en critiquant ce que l‟interlocuteur avait exprimé. Les candidats ont fait appel à la formation d‟un scénario d‟espoir, de crédulité, de respect et d‟éthique, conforme à la dignité de l‟être humain. Ces résultats mettent en évidence la façon dont des sujets multiples et hétérogènes, insérés dans la dimension de la vie, prennent position à l‟intérieur des pratiques discursives, face aux coordonnées d‟espace et de temps

Pré-fabricados lingüísticos: estrutura e funcionamento de sintagmas verbais idiomatizados - por uma abordagem cognitivo-funcional em sala de aula

This work aims at under the cognitive-functional perspective describing, inside the vast domain of the linguistic prefabs, the structure and the functioning of the Idiomatic Verb Phrases (SVIs), produced by speakers of the Portuguese from Brazil, located in Natal (RN). From the functionalist presupposition that the language is used essentially to assist to communicative demands, it is observed that its morphologic-syntactic structure is conditioned to the inherent pragmatic vicissitudes to the verbal interaction of subjects, socially heterogeneous and historically established. It is focalized, in the composition of SVIs, the relationships VT + OD (transitive verb + direct object), characterizing the syntactic-semantic nature of the verb and of the respective verbal complement. Those verb combinations + complement can be interpreted as lexical structures, reflexes of the idiomaticity inherent to conventional constructions already systematized in the users' of the language cultural repertoire. It is sought, still, to glimpse the cognitive and discursive motivations pertinent to that linguistic phenomenon. In the investigative process, are analyzed exclusive data of speech collected in Corpus Discurso & Gramática a lingua falada e escrita na cidade do Natal, organized by Furtado da Cunha (1998). The adopted methodological procedures configure as methods of empiric analysis and use of the intuition, being emphasized the qualitative approach (explanatory) of the data with quantitative support of statistical indicators. It shows, finally, a grating of didactic suggestions on SVIs, for Portuguese's classes, as subsidies to the educational practice in the Medium Teaching and in the course of Letters.

Comportamento social de botos-cinza, sotalia guianensis, na praia de Pipa, RN, Brasil: dinâmica, sequência, sincronia e respostas ao turismo de observação

Social behavior of Guiana dolphins, Sotalia guianensis, at Pipa Beach, RN, Brazil: dynamics, sequence, breathing synchrony, and responses to dolphin watching. Social animals form groups that can range from temporary to permanent. Depending on the nature of the social relationships developed between individuals, groups present a particular social organization and the effect of these interactions shapes the activity patterns of these animals. This study investigates: (i) fission-fusion dynamics of Guiana dolphins, through the analysis of three dimensions of the social system (variation in spatial cohesion, variation in size and composition of groups), (ii) sequence, routine and behavioral stability, (iii) breathing intervals in synchronized groups and (iv) behavioral responses of the animals to dolphin watching. Systematic observations of Guiana dolphins were made from a platform located in cliffs about 25 m above sea level that surround Madeiro Bay, Pipa Beach. Sampling occurred from December 2007 to February 2009 between 0600 h and 1600 h, and the groups of Guiana dolphins were investigated according to their size (alone and group) and composition (adults, adults and juveniles, and adults and calves). According to the analysis of fission-fusion dynamics, Guiana dolphin groups frequently changed their composition, modifying their patterns of spatial grouping and cohesion every 20 minutes on average. More than 50% of the individuals maintained a distance of up to 2 m from other group members and new individuals were attracted to the group, especially during feeding, leaving it for foraging. Large groups were more unstable than small, while groups containing only adults were more stable than groups of adults and juveniles. According to the Z-score analysis to investigate the sequence and behavioral routine, lone individuals were more ! .7! ! involved in foraging and feeding, while resting was more common in groups. Foraging and feeding were more common in homogeneous groups (individuals of the same age class), while heterogeneous groups (different age classes) were often involved in socialization, displaying a broader behavioral repertoire. Foraging and resting behavior presented higher stability (continuous duration in minutes) than the other behaviors. The analysis of breathing intervals in synchronized groups showed significant differences depending on type of behavior, composition and area preference. During resting, breathing intervals were of longer duration, and groups with calves showed shorter breathing intervals than groups without calves. Lone individuals also preferred areas called corral , often used for the entrapment of fishes. The Markov chain analysis revealed behavioral changes in the presence of boats, according to the type of group composition. Groups composed of adults presented decreased resting and increased in traveling during the presence of boats. Groups of adults and juveniles showed a massive reduction of socialization, while the behavior transition probability traveling-traveling was higher in groups of adults and calves. In the presence of the boats, stability of resting was reduced by one third of its original duration and traveling more than doubled. The behavioral patterns analyzed are discussed in light of socio-ecological models concerning costs and benefits of proximity between individuals and behavioral optimization. Furthermore, significant changes in behavioral patterns indicate that Guiana dolphins, at Pipa Beach, have suffered the effects of tourism as a result of violation of rules of conduct established for the study area

Estudo da regeneração de aditivos para catalisadores de craqueamento aluminofosfatos (ALPO s)e silicoaluminofosfatos (SAPO s)

Heterogeneous catalysts such as aluminophosphate and silicoaluminophosphate, molecular sieves with AEL of ALPO-11 and SAPO-11, were synthesized by the hydrothermal method with the following molar composition: 2.9 Al +3.2 P + 3.5 DIPA +32.5 H20 (ALPO-11); 2.9 Al +3.2 P + 0.5 Si + 3.5 DIPA +32.5 H20 (SAPO-11) starting from silica (only in the SAPO-11), pseudoboehmite, orthophosphoric acid (85%) and water, in the presence of a di-isopropylamine organic template. The crystallization process occurred when the reactive hydrogel was charged into a vessel and autoclaved at 170ºC for a period of 48 hours under autogeneous pressure. The obtained materials were washed, dried and calcined to remove the molecular sieves of DIPA. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), infrared spectroscopy (FT-IR), thermo gravimetric differential thermal analysis (TG/DTA) and nitrogen adsorption (BET). The acidic properties were determined using adsorption of n-butylamine followed by programmed thermodessorption. This method revealed that ALPO-11 has weaker acid sites due to structural defects, while SAPO-11 shows an acidity that ranges from weak to moderate. However, a small quantity of strong acid sites could be detected there. The deactivation of the catalysts was conducted by the cracking of the n-hexane in a fixed bed continuous flow microrreator coupled on line to a gas chromatograph. The main products obtained were: ethane, propane, isobutene, n-butane, n-pentane and isopentane. The Vyazovkin (model-free) kinetics method was used to determine the regeneration and removal of the organic template

Hidróxidos duplos lamelares aplicados à obtenção de biodiesel

In this paper, the Layered Double Hydroxides (LDH s) type hydrotalcite were synthesized, characterized and tested as basic heterogeneous catalysts for the production of biodiesel by transesterification of sunflower oil with methanol. The synthesis of materials Layered Double Hydroxides (LDH s) by co-precipitation method from nitrates of magnesium and aluminum, and sodium carbonate. The materials were submitted to the variation in chemical composition, which is the amount of Mg2+ ions replaced by Al3+. This variation affects the characteristic physico-chemical and reaction the solid. The molar ratio varied in the range of 1:1 and 3:1 magnesium / aluminum, and their values between 0.2 and 0.33. This study aims to evaluate the influence of variation of molar ratio of mixed oxides derived from LDH s and the influence of impregnation of a material with catalytic activity, the KI, the rate of conversion of sunflower oil into methyl esters (biodiesel) through transesterification by heterogeneous catalysis. .The catalysts were calcined at 550 ° C and characterized by X-ray diffraction (XRD), scanning electron microscopy and energy dispersive spectroscopy of X-ray (SEM / EDS), thermogravimetric analysis (TG) and test basicity. The transesterification reaction was performed for reflux is a mixture of sunflower oil and methanol with a molar ratio of 15:1, a reaction time of 4h and a catalyst concentration of 2% by weight. The physical-chemical characterization of sunflower oil and biodiesel obtained by the route methyl submitted according NBR, EN, ASTM. Subsequently, it was with the chromatographic and thermogravimetric characterizations of oils. The results of chromatographic analysis showed that the catalysts were effective in converting vegetable oil into biodiesel, in particular the type hydrotalcite KI-HDL-R1, with a conversion of 99.2%, indicating the strong influence of the chemical composition of the material, in special due to presence of potassium in the structure of the catalyst