O Núcleo genuíno lateral dorsal do tálamo do sagüi (callithrix jacchus): Pprojeção retiniana, caracterização citoarquitetônica e neuroquimica da principal estação visual primária.

The thalamus plays an important role in the sensorial processing information, in this particular case, the visual information. Several neuronal groups have been characterized as conductors and processors of important sensorial information to the cerebral cortex. The lateral geniculate complex is one to them, and appears as a group very studied once it is responsible, in almost all totality, for the processing of visual information. Among the nuclei that constitute the lateral geniculate complex we highlight the dorsal lateral geniculate nucleus of the thalamus (DLG), the main thalamic relay for the visual information. This nucleus is located rostral and lateral to medial geniculate nucleus and ventral to thalamic pulvinar nucleus in most of the mammals. In the primates humans and non-humans, it presents as a laminate structure, arranged in layers, when observed in coronal sections. The objective of this work was to do a mapping of the retinal projections and a citoarchictetonic and neurochemical characterization of DLG in the marmoset (Callithrix jacchus), a New World primate. The retinal projections were traced by anterograde transport of subunit b of cholera toxin (CTb), the citoarchicteture was described by Nissl method, and to neurochemical characterization immunohistochemicals technical were used to examine the main neurotransmitters and neuroatives substances present in this neural center. In DGL of marmoset thalamus, in coronal sections labeled by Nissl method, was possible to visualize the division of this nucleus in four layers divided in two portions: magnocellular and parvocellular. The retinal projections were present being visualized fibers and terminals immunorreactives to CTb (IR-CTb) in the DLG ipsilateral and contralateral. And through the immunohistochemicals techniques was observed that DLG contain cells, fibers and/or terminals immunoreactives against neuronal nuclear protein, subunits of AMPA 15 glutamate receptors (GluR1, GluR2/3, GluR4), choline acetyltransferase, serotonin, glutamic acid decarboxylase, binding calcium proteins (calbindin, parvalbumin and calretinin), vasopressin, vasoactive intestinal polypeptide, and an astrocyte protein, glial fibrillary acidic protein.

Caracterização citoarquitetônica, neuroquímica e de aferência óptica do complexo parabraquial do sagui (Callithrix jacchus)

The parabrachial complex (PB) is an area of the brainstem responsible for the processing and transmission of essential physiologic information for the survival of the organisms. This region is subdivided in approximately nine subregions, considering morphology, cytoarchitectural and functional characteristic. Its neurons have an extensive network of connections with other regions of the nervous system. The objective in this work was to map the retinal projection to the PB and make a citoarchitectonic and neurochemical characterization of this region in the common marmoset (Callithrix jacchus), a primate of the New World. The retinal projections were mapped by anterograde transport of the choleric toxin subunit b (CTb). The citoarchitecture was described through the Nissl method, and the neurochemical characterization was made through immunohistochemical technique to the some neurotransmitters and neuroactives substances present in this neural center. In marmoset PB, in the coronal sections labeled by Nissl method, we found a similar pattern to that evidenced in other animal species. The immunoreactivity against CTb was verified in the PBMv in fibers/terminal, characterizing such as retinal innervations in this area. The immunohistochemical technique reveled that the PB contain cells, fibers and/or terminals immunoreactives to the neuronal nuclear protein, Choline acetyl transferase, nitric oxide synthase, serotonin, enkephalin, substance P, Calcium-binding proteins (calbindin, calretinin e parvalbumin), and glial fibrillary acidic protein. The histochemical technique reveled cells and fibers NADPH-diaphorase reactive. Each one of those substances presented a characteristic pattern of demarcation in PB, and some serve as specific markers of subregions

Caracterização do ciclo sono/vigília de professores do ensino médio em natal/rn

In the school environment is fundamental the knowledge about the sleep-wake cycle (SWC), because we find children and adolescents with excessive sleepiness and learning difficulties. Furthermore, teachers with high demand and with different work schedule, which may contribute to changes in SWC. The aim of this study was to describe the SWC of high school teachers in Natal/RN. Habits and knowledge about sleep, chronotype, SWC, daytime sleepiness, sleep quality and job satisfaction were described in 98 high school teachers from public and private school. These parameters were compared according to the characteristics of work, family structure and gender. Data collection was performed with the use of questionnaires in two stages: 1) "health and sleep" (general characterization of sleep habits), Horne & Ostberg questionnaire (characterization of chronotype), Epworth Sleepiness Scale and the Index of Pittsburg Sleep Quality, 2) The sleep diary for 14 days. From the results, we observe that the teachers woke up and went to bed earlier in the week and showed a reduction of time in bed around 42min comparing to weekend. This reduction in time in bed during the week was accompanied by an increase in nap duration on weekend. In addition the teachers woke up earlier on Saturdays than on Sundays, probably due to housework and leisure. The teachers' knowledge about sleep was low in relation to individual differences and effect of alcoholic beverages on sleep, and high in the consequences of sleep deprivation. The differences found in comparisons on the characteristics of work, family structure and gender were punctual, except concerning the work schedule. The teacher who started work in the morning and finished in the night, woke up earlier, went to bed later and had less time in bed, when compared to teachers who work only in two shifts. In addition, teachers with late chronotypes who begin the work in the morning had a greater irregularity in the wake up time compared to teachers with earlier and intermediate chronotypes. Half of teachers have excessive sleepiness, which was positive correlated with work dissatisfaction. In general, teachers showed IPSQ averages equivalent to poor sleep quality and the women showed worst averages. From the results, it is suggested that the SWC of teachers varies according to work schedule, leading to irregularity and partial sleep deprivation in the week, although these responses vary according to chronotype. These changes are accompanied by excessive daytime sleepiness and poor sleep quality. However, it is necessary to expand the sample to clarify the influence of variables related to work, family structure and gender together

Caracterização do repertório acústico do botocinza, sotalia guianensis, e impacto de embarcações no nordeste do brasil

The wide distribution along the Brazilian coast of specie Sotalia guianensis has been growing interest in searchers on the ecology of this species, addition to commercial interests by whalewatching. This work described the accoustic repertory of S. guianensis and their behavior associated and found if underwater noises affect this repertorie in Pipa-RN. It were analyzed 18:49h of recordings maked between april and june/2009. It were found 3258 whistles, 289 calls, 873 clicks and no gargle. The frequencies range of guiana dolphins was 1 a 48kHz and may be related to system response recorder and population s regionalization. The frequencies overlaps the noise made by motorboats, schooners and water bomb. The behavior travelling ocurred siletly in 72,58% and socialization presented no sound (56,4%) and presence of sound (43,6%). This great absence of sound may be relacioned to saving energy, probably because in this behaviors they can use physical and visual contacts. The foraging presented highest records of all class noise with 46,84% clicks, 33,84% whistles and 9,02% calls. All this sounds occurred differently in each behavior (travelling: x2 = 134,35 df = 3 p = 0,0001; foraging: x2 = 19,83 df = 3 p= 0,00018 and socialization x2 = 60,35 df = 3 p = 0,0001). It was possible to determine that underwater noise cause changes in the repertorie and does a considerable increase in whistle s number and reduce clicks. Also occurs changes in some whistles (FI: t=2,42, p=0,015; FF: t= -2,22, p=0,025), calls (FMI: t= -3,13, p=0,001; FMA: t= -3,49, p=0,0005; FD: t= -2,21, p=0,027; D: t=2,89, p=0,004) and clicks parameters (D: t= -3,85, p=0,0001; I: t= -5,32, p=0,0001) during presence of noise. These changes may be a strategy of these animals to win this sound barrier. We can not say which noise has more impact, ix however the water bomb seems to affect more the clicks and the motorboats seems to affect the others sounds. Little is know about auditive sensibility of this specie, but daily exposure to this noise may cause damage and this specie appears to have residence. The specie conservation is necessary because the population already seems to suffer damage as decrease in length of stay, number of individuals entering the inlet and the apparent diminution in the foragind during vessels presence and control standards and ambiental education can help. So, we can advance in knowledge about the ecology of this specie especially when it come to bioacoustics and their behaviors associated and reveals some of the impacts that the noise have brought to this population

Disfunção sexual feminina e níveis dos hormônios esteroidais em mulheres obesas atendidas no ambulatório de cirurgia bariátrica do hospital universitário Onofre Lopes em Natal/RN

A disfunção sexual corresponde a alterações em uma ou mais fases da resposta sexual humana e apresenta maior prevalência na população feminina. Ademais, a participação de alguns fatores como obesidade e níveis dos hormônios esteroidais na disfunção sexual feminina (DSF) permanece incerta. O presente estudo deteve-se na análise da ocorrência de DSF numa população de mulheres portadoras de obesidade, cadastradas no Ambulatório de Cirurgia Bariátrica do Hospital Universitário Onofre Lopes, da Universidade Federal do Rio Grande do Norte, no município de Natal, RN. O estudo foi realizado em uma amostra composta por trinta e uma mulheres, com idade entre 20 e 50 anos, com índice de massa corpórea (IMC) > 30 Kg/m2. A todas as pacientes foi aplicado um questionário composto por uma seção com dados socio-econômicos, e outra abordando a saúde sexual feminina, sendo esta última correspondente ao Female Sexual Function Index (FSFI), para diagnóstico de DSF. A partir dessa caracterização, as pacientes foram reunidas nos grupos CD (pacientes com disfunção, n= 9) e SD (sem disfunção, n= 22). Para a análise do efeito da obesidade na DSF, as pacientes foram reunidas nos grupos 1 (6 pacientes com IMC grau I e II: entre 30 e 40 Kg/m2) e 2 (25 com IMC grau III: acima de 40). Para o estudo da participação dos hormônios esteroidais foram determinadas as concentrações séricas de cortisol, estradiol e dehidroepiandrosterona (DHEA) pelo método de quimiluminescência. A análise estatística dos dados foi realizada usando os testes ANOVA, MANOVA (Pillai), além de análise de Cluster. Para identificar as diferenças entre os domínios do FSFI, foi usado o teste T de Student. A significância considerada para todos os testes foi para p< 0,01. Das pacientes estudadas, 25,8% apresentaram DSF de acordo com o escore total do FSFI. A análise estatística posterior evidenciou que as diferenças ocorreram para os domínios desejo, excitação e orgasmo. Não foi encontrada relação da presença de DSF com os diferentes graus de obesidade ou com os níveis hormonais dos esteróides cortisol, estradiol ou DHEA. Contudo, foi encontrado aumento significativo nos níveis séricos de estradiol para o grupo 1, que corresponde ao de menor índice de IMC. Estes resultados mostram que a prevalência de DSF não diferiu entre os graus I,II e III de obesidade das pacientes deste estudo mas, quando presente, a disfunção ocorre nos domínios desejo, excitação e orgasmo. A maior concentração de estradiol encontrada nas pacientes de menor índice de IMC sugere uma possível relação entre as duas variáveis que precisa ser investigada em estudos futuros.

Os núcleos dopaminérgicos do mesencéfalo do mocó (kerodon rupestris): caracterização citoarquitetônica e por imunoistoquímica para tirosina-hidroxilase

The 3-hydroxytyramine/dopamine (DA) is a monoamine of catecholamineric group and consists in the progenitor substantia of synthesis of noradrenaline and adrenaline, having the enzyme tyrosine hydroxylase as a regulator of this process. Nuclei of midbrain expressing DA are the retrorubral field (RRF, A8 group), the substantia nigra pars compacta (SNc, A9 group) and the ventral tegmental area (VTA, A10 group). These nuclei are involved in three complex circuitry called mesostriatal, mesocortical and mesolimbic, which are related directly with various behavioral manifestations such as motor control, reward signaling in behavioural learning, motivation and pathological manifestations of Parkinson s disease and schizophrenia. The aim of this study was describe the morphology of midbrain dopaminergic neurons (A8, A9 and A10) of the rock cavy (Kerodon rupestris), a rodent belonging to the family Caviidae typical of the Brazilian Northeast, which is being adopted as a model for neuroanatomical studies in laboratory of neuroanatomy of the Federal University of Rio Grande do Norte. Coronal sections of brains of the rock cavies were submitted to staining by Nissl s method and immunohistochemistry against tyrosine hydroxylase. The nuclear organization of the midbrain dopaminergic nuclei of the rock cavy is very similar to that found in other animals of the order Rodentia, except by the presence of the tail of substantia nigra, which was found only in the studied species. We concluded that the midbrain dopaminergic nuclei are phylogenetically stable among species, but we think to be it necessary to expand the studies about the particularity found the rock cavy, investigating its occurrence in other species of rodents or investigating its functional relevance

Caracterização da frequência de atividades aéreas do golfinho-rotador, Stenella longirostris (Gray, 1828), na Baía dos Golfinhos do Parque Nacional Marinho de Fernando de Noronha

The aerial activities, leaps and slaps with parts of the body in the surface of water, are part of the behavioral repertoire of several species of cetaceans. Among them, the spinner dolphin, Stenella longirostris, shows greater diversity in such behavior. For the spinner dolphins of Fernando de Noronha, the aerial activities are classified as vertical and horizontal, with eight patterns to be noted (tail slap, head slap, motor boating, partial leap, leap, spin, tail over head and tail over head with spin) discriminated between these categories. Such behaviors can be used as a parameter to identify behavioral changes, as well as patterns of daily and seasonal activity. In this manner, this study aimed to characterize the frequency in performance of such activity while the dolphins were within the Dolphin Bay of Fernando de Noronha, and verify possible daily and seasonal hourly fluctuations on such behaviors. The data analyzed in this study was acquired during the period of January 2006 through December 2010, totaling 1431 days of observation from land set point, with 113027 aerial activities registered, daily average of 72,27 (SD=96,10). During 5478h and 54 min of observation the horizontal aerial activity was the most observed and rotation was the most executed pattern. Greater frequency of execution of aerial activity was observed in adults, but for both adults and calves, was observed a predominance of horizontal activities, with spin being the pattern most executed. Positive correlation was observed between the amount of aerial activity performed and the number of animals inside the Bay. Hourly daily fluctuation was observed in the expression of aerial activities by spinner dolphins, and was observed a peak of activity between 8h and 8h59min for the overall frequency relative of aerial activities, as well as for the categories and patterns. Seasonal differences were observed between the rainy and dry season with the greater amount of activity being observed during the rainy season. Nevertheless, the same profile of frequency relative of aerial activity was observed in both seasons with the peak amount being during the same period. When discriminated the aerial activities in categories and patterns, for both seasons, there was a similar pattern of hourly fluctuation; for most of parameters, higher frequency relative of execution of aerial activity remain between 8h and 8h59min

Padrão de distribuição e caracterização morfológica de fibras serotonérgicas nos núcleos da linha Média/ intralaminares do tálamo do mocó (Kerodon rupestris)

The midline/intralaminar nuclei form a remarkable group of nuclei of the medial and dorsal thalamus. The midline nuclei, in rats, comprises the paratenial nuclei (PT), paraventricular (PV), intermediodorsal (IMD), reuniens (Re) and rhomboid (Rh). The intralaminar nuclei comprises the central medial (CM), paracentral (PC), central lateral (CL) and parafascicular (PF). Such nuclei have dense serotonergic innervation originating from the brainstem, especially from the so-called ascending activation system. These nuclei, in turn, send projections to various cortical and subcortical areas, specifically to limbic areas, which suggests the important role of this neurotransmitter in the limbic circuitry. The aim of this study was to characterize the distribution pattern and morphology of serotonin fibers in the nuclei of the midline and intralaminar thalamic of rocky cavy (Kerodon rupestris), a tipical rodent from brazilizan northeast. To reach this aim we used four rock cavies adults. Following the transcardially perfusion with paraformaldehyde and brain microtomy steps was performed immunohistochemistry for serotonin (5-HT), Nissl technique and subsequent achievement and image analysis to characterize the cytoarchitecture of these nuclei and the serotonergic fibers visualized. An analysis was made of Relative Optical Density (ROD) to semi-quantify the concentration of serotonin fibers in the areas of interest. Thus, we observed a cytoarchitectonic arrangement of these nuclei similar to that found in rats. In case of fibers distribution, those immunoreactive to 5-HT were presented in a higher concentration according as ROD in the midline nuclei relative to intralaminar; Re being the core which has a higher pixel value followed by the PV , Rh, IMD and PT. In intralaminar CL showed higher pixels, followed by nuclei CM, PC and PF. The serotonergic fibers were classified as number of varicosities and axon diameter, therefore find three types of fibers distributed through this nuclear complex: fibers rugous, granular and semi-granular. In PV fibers predominated rugous; in PT fibers predominated granular; IMD, CL and PF fibers were represented by semi-granular and Re, Rh, PC and CM fibers showed granular and semi-granular. Morphological characterization of serotonergic fibers and differences in density between the nuclei may suggest different patterns of synaptic organization of this neurotransmitter beyond confirming his large repertoire functional

Projeção retiniana, caracterização citoarquitetônica e neuroquímica da zona incerta do moco (Kerodon rupestris)

The Zona Incerta (ZI) is embryologically derived from the ventral thalamus, in continuity with the reticular nucleus of the thalamus. Studies usingneural tracers technics have allowed identify a complex connectional map including the ZI. Futhermore, cytochemical, molecular and functional data have shown abundant variability in the neurochemical contend in the ZI, as well as,the involvement of the ZI in the modulation of nociception, attention, alertness, control and maintenance of posture and control of visceral activity. This work aims to characterize the cytoarchitecture, neurochemical content of the ZI in the rock cavy (Kerodon rupestris), and a direct retinal-ZI pathway present in this species. The Nissl staining is effective for the delineation and characterization of ZI citoarchitecture. ZIc receives a contralateral retinal projection showing varicosities, suggesting a modulatory character of photic information. The ZI in the rock cavy, as in others rodents and primates, is characterized by a complex neurochemical signature. The ZI neurochemistry presents great diversity, especially in the medial portion of ZIr, where we have found immunoreactivity of all neuroactive substances investigated, and that NOS-IR, GFAP and CR helped the delimitation of middle ZI in ZId and ZIv. Nevertheless, just 5-HT-IR fibers are present in all subdivisions of the ZI. These data demonstrate the great wealth of the neurochemistry of rock cavy s ZI and a direct retinal modulation in the ZI, helping to explain it s broad functional repertory

Aplicabilidade do Rorshach na avaliação psicológica do autismo

This study investigates the applicability of the Rorschach Method for evaluating the personality of people with Autism Spectrum Disorder (ASD).The relevance of this study is justified by the limited number of investigations published in the research literature concerning the use of psychological tests used for evaluating the personality of individuals with ASD. The Rorschach Method was chosen as an appropriate instrument considering it reveals the personality s basic structure, including characteristics of the affectivity, sensuality, inner life, mental resources, psychic energy and general characteristics and intellectual state of the individual. The general objective of this investigation consisted of verifying the applicability of the use the Rorschach Method in the evaluation of the characteristics of people's personality with autism spectrum disorder (ASD).The study also sought to identify perceptive factors of the personality structure of individuals with ASD, provide contributions of the understanding of this syndrome, seeking the establishment of possible therapeutic interventions starting from diagnostic by Rorschach Method. In addition, this investigation aims at verifying the adequacy of using the Rorschach Method as an instrument for evaluating the personality characteristics of individuals with ASD and its possible use in Brazil, starting from preliminary normative results. Participants consisted of 44 youngsters and adults, both genders with age range 14 - 39 years-old (average: 23.5 years-old) distributed in 2 groups. Group 1: composed with 22 youngsters and adults with clinical diagnosis of autism spectrum disorder (communication impairments, social interaction deficits, restricted and repetitive interests and activities); Group 2: composed with 22 youngsters and adults with typical behavior. The participants were paired to gender and age, individually. The Mann-Whitney and Wilcoxon tests were applied to evaluate statistical differences between the groups, considering demographic and social data. The results indicate the presence of restricted interest or difficulty in the expression of the social and affective interaction of people with ASD. However, the need of broader normative studies concerning the use of personality evaluation instruments for people with ASD is warranted. These investigations could help understand the psychic dynamism of this population, offering subsidies that can be added to the current techniques of diagnosis. The Rorschach Method is susceptible to application but it is necessary to respect the individual limitations of these people and to establish more criterions about the spectrum

Síntese, caracterização e aplicação do MCM-41 e A1-MCM-41 na pirólise do resíduo atmosférico de petróleo

In present work, mesoporous materials of the M41S family were synthesized, which were discovered in the early 90s by researchers from Mobil Oil Corporation, thus allowing new perspectives in the field of catalysis. One of the most important members of this family is the MCM-41, which has a hexagonal array of mesopores with pore diameters ranging from 2 to 10 nm and a high surface area, enabling it to become very promising for the use as a catalyst in the refining of oil in the catalytic cracking process, since the mesopores facilitate the access of large hydrocarbon molecules, thereby increasing the production of light products, that are in high demand in the market. The addition of aluminum in the structure of MCM-41 increases the acidity of the material, making it more beneficial for application in the petrochemical industry. The mesoporous materials MCM-41 and Al-MCM-41 (ratio Si / Al = 50) were synthesized through the hydrothermal method, starting with silica gel, NaOH and distilled water. CTMABr was used as template, for structural guiding. In Al-MCM-41 the same reactants were used, with the adding of pseudoboehmite (as a source of aluminum) in the synthesis gel. The syntheses were carried out over a period of four days with a daily adjustment of pH. The optimum conditions of calcination for the removal of the organic template (CTMABr) were discovered through TG / DTG and also through analysis by XRD, FTIR and Nitrogen Adsorption. It was found that both the method of hydrothermal synthesis and calcination conditions of the studies based on TG were promising for the production of mesoporous materials with a high degree of hexagonal array. The acidic properties of the materials were determined by desorption of n-butylamine via thermogravimetry. One proved that the addition of aluminum in the structure of MCM-41 promoted an increase in the acidity of the catalyst. To check the catalytic activity of these materials, a sample of Atmospheric Residue (RAT) that is derived from atmospheric distillation of oil from the Pole of Guamaré- RN was used. This sample was previously characterized by various techniques such as Thermogravimetry, FTIR and XRF, where through thermal analysis of a comparative study between the thermal degradation of the RAT, the RAT pyrolysis + MCM-41 and RAT + Al- MCM-41. It was found that the Al-MCM-41 was most satisfactory in the promotion of a catalytic effect on the pyrolysis of the RAT, as the cracking of heavy products in the waste occurred at temperatures lower than those observed for the pyrolysis with MCM-41, and thereby also decreasing the energy of activation for the process and increasing the rates of conversion of residue into lighter products

Síntese e Caracterização de Titanatos de Cobalto e Níquel, dopados com Praseodímio, obtidos a partir da decomposição de Nitrilotriacetatos

In recent years, studies about the physicochemical properties of mixed oxides, call attention of the scientific community, properties like as piezoelectricity, photoluminescence, or applications as catalysts, arise in these compounds, when their chemical compositions are modified, in this context some routes are employed in the synthesis of these materials, among which can be cited these methods: ceramic, combustion, co-precipitation, Pechini or polymeric precursor method, hydrothermal, sol-gel; these routes are divided into traditional routes or chemical routes. In this work were synthesized oxides with variable composition, from the thermal decomposition of titanium, cobalt, nickel and praseodymium nitrilotriacetates. The nitrilotriacetates were characterized by IR Spectroscopy (FTIR), Thermogravimetric (TG/ DTG) and Differential Scanning Calorimetry (DSC), while oxides have been characterized by X-ray diffraction (XRD), Spectrofluorimetry and IR Spectroscopy (FTIR). From FTIR data, it was demonstrated that the displacement of the band corresponding to the carboxylate group (νCOOH) at 1712 cm-1, present in nitrilotriacetic acid (H3NTA), for 1680-1545 cm-1, these stretches are characteristics of coordinated nitrilotriacetates, By thermal analysis (TG/DTG /DSC), it was suggested, that in an oxidizing atmosphere (air) oxides are obtained at lower temperatures than in an inert atmosphere N2(g). By results from X-ray Diffraction (XRD), it was determinated that the oxides are crystalline and the predominant phases obtained are summarized titanate phases rutile and ilmenite. By fluorimetry was observed that the intensity of emission bands are directly proportional to the concentration of ions Ni2+, Co2+ and Pr3+, and IR spectroscopy (FTIR) from oxides, demonstrated the disappearance of characteristic bands by nitrilotriacetates, determining the complete decomposition of the nitrilotriacetates in oxides

Síntese e caracterização de membranas zeolíticas tipo mfi e aplicação em separação de aromáticos

The synthesis of MFI-type zeolite membranes was carried by the process in situ or hydrothermal crystallization. We studied the homogenization time of the room temperature and gel filtration just before the crystallization step performed out in an oven, thus obtaining a more uniform zeolite film. The powder synthesized zeolite (structure type MFI, Silicalite) was characterized by several complementary techniques such as Xray diffraction (XRD), scanning electron microscopy (SEM), thermal analysis, temperature programmed desorption (TPD), Fourier Transform infrared spectroscopy (FTIR) and textural analysis by nitrogen adsorption (specific surface area). For the purpose of evaluating the quality of the layer supported on the ceramic support, N2 permeation tests were carried starting from room temperature to 600 °C, where values were observed values more appropriate permeation from 200 °C. With the data obtained, it was made into a graph of temperature versus permeation function, the curve of surface diffusion was found. For scanning electron microscopy, we observed the formation of homogeneous crystals and the zeolite film showed no fissures or cracks, indicating that the process of synthesis and subsequent treatments not damaged the zeolite layer on the support. Carried permeation studies were found values ranging from 3.64x10-6 to 3.78x10-6, 4.71x10-6 to 5.02x10-6, to pressures 20 and 25 psi, respectively. And the mixture xylenes/N2 values were between 5.39x10-6 to 5.67x10-6 and 8.13x10-6 to 8.36x10-6, also for pressures of 20 and 25 psi. The values found for the separation factor were 15.22 at 400 °C in the first experiment and 1.64 for the second experiment at a temperature of 150 °C. It is concluded that the Silicalite membrane was successfully synthesized and that it is effective in the separation of binary mixtures of xylenes

Caracterização de resíduo sólido formado em biodiesel de sebo bovino

Biodiesel production has increased over the last decade because of the benefits associated with this fuel, including renewability, domestic feedstock, lower toxicity, and biodegradability. From 2008, the use of beef tallow as a feedstock for biodiesel production in Brazil has increased in significance, representing the second largest source of biodiesel, after soybeans. However, the performance of biodiesel in cold weather conditions is worse than diesel because of deposition of insoluble at low temperatures, accelerating the plugging of fuel filters and injectors of the vehicle engine. Studies have been conducted on beef tallow biodiesel, mostly related to the properties of thermal and oxidative stability. However, few studies have described the nature of the precipitate formed and its influence on product quality. Research suggests that the cause of deposition is related to the nature of saturated esters and monoacylglycerols as inducing agents. This study monitored the levels of mono-, diand triacylglycerols, the oxidation stability and the cold filter plugging point (CFPP) in beef tallow biodiesel samples from two commercial producers in Brazil for a period of twelve months. Filtered precipitates were analyzed by comparative techniques of GCFID, HPLC-UV/VIS, HPLC-MS-IT-TOF and TG to verify the nature, using monopalmitin and monostearin as reference standards. The formation of precipitate reduced the levels of monoacylglycerols in the beef tallow biodiesel. GC-FID and LCMS- IT-TOF results confirmed the nature of the deposit as saturated monoacylglycerols, predominantly monostearin and monopalmitin as the second major component. Moreover the TG analysis of the residue indicated similar thermal decomposition of the reference standards. The precipitate did not affect the oxidation stability of beef tallow biodiesel and the CFPP characteristic of blends up B60. However, the presence of iron reduced significantly the oxidation stability of biodiesel

Caracterização de resíduo sólido formado em biodiesel de sebo bovino

Biodiesel production has increased over the last decade because of the benefits associated with this fuel, including renewability, domestic feedstock, lower toxicity, and biodegradability. From 2008, the use of beef tallow as a feedstock for biodiesel production in Brazil has increased in significance, representing the second largest source of biodiesel, after soybeans. However, the performance of biodiesel in cold weather conditions is worse than diesel because of deposition of insoluble at low temperatures, accelerating the plugging of fuel filters and injectors of the vehicle engine. Studies have been conducted on beef tallow biodiesel, mostly related to the properties of thermal and oxidative stability. However, few studies have described the nature of the precipitate formed and its influence on product quality. Research suggests that the cause of deposition is related to the nature of saturated esters and monoacylglycerols as inducing agents. This study monitored the levels of mono-, diand triacylglycerols, the oxidation stability and the cold filter plugging point (CFPP) in beef tallow biodiesel samples from two commercial producers in Brazil for a period of twelve months. Filtered precipitates were analyzed by comparative techniques of GCFID, HPLC-UV/VIS, HPLC-MS-IT-TOF and TG to verify the nature, using monopalmitin and monostearin as reference standards. The formation of precipitate reduced the levels of monoacylglycerols in the beef tallow biodiesel. GC-FID and LCMS- IT-TOF results confirmed the nature of the deposit as saturated monoacylglycerols, predominantly monostearin and monopalmitin as the second major component. Moreover the TG analysis of the residue indicated similar thermal decomposition of the reference standards. The precipitate did not affect the oxidation stability of beef tallow biodiesel and the CFPP characteristic of blends up B60. However, the presence of iron reduced significantly the oxidation stability of biodiesel