Adsorção do corante amarelo reativo BF-4G 200% por argila esmectita

This study aimed to evaluate the potential use of smectite clays for color removal of textile effluents. The experiments were performed by testing exploratory/planning method factorial and fractional factorial where the factors and levels are predetermined. The smectite clays were used originating from gypsum hub of the region Araripe-PE, and the dye used was Reactive Yellow BF-4G 200%. The smectite clay was collected and transported to the Laboratory of Soil Physics of UFRPE, where it held its preparation through air drying, lump breaking and classification in sieve to then submit it to the adsorption process. Upon completion of 22 complete factorial design it was concluded that the values of (96, 96,5 and 95,8%) corresponding to the percentage of of removal for "in-kind", chemically and thermally activated, respectively and adsorbed amounts of (4,80, 4,61 and 4,74 mg/g) for three clays. Showed that the activation processes used did not increase the adsorption capacity of smectite clay. The kinetic data were best fitted to the Freundlich isotherm, with an exponential distribution of active sites and that shows above the Langmuir equation for adsorption of cations and anions by clays. The kinetic model that best adapted to the results was the pseudosecond order model. In the factorial design study 24-1, at concentrations up to 500 mg/L obtains high percentage of color removal (92,37, 90,92 and 93,40%) and adsorbed amount (230,94, 227,31 and 233,50 mg/g) for three clays. The kinetic data fitted well to Langmuir and Freundlich isotherms. The kinetic model that best adapted to the results was the pseudosecond order model

Avaliação da capacidade de adsorção do CO2 em zeólita 12X com gases sintéticos e originados da pirólise do lodo de esgoto

This work depicts a study of the adsorption of carbon dioxide on zeolite 13X. The activities were divided into four stages: study batch adsorption capacity of the adsorbent with synthetic CO2 (4%), fixed bed dynamic evaluation with the commercial mixture of gases (4% CO2, 1.11% CO, 1 2% H2, 0.233% CH4, 0.1% C3, 0.0233% C4 argon as inert closing balance), fixed bed dynamic modeling and evaluation of the breakthrough curve of CO2 originated from the pyrolysis of sewage sludge. The sewage sludge and the adsorbent were characterized by analysis TG / DTA, SEM, XRF and BET. Adsorption studies were carried out under the following operating conditions: temperature 40 °C (for the pyrolysis of the sludge T = 600 °C), pressures of 0.55 to 5.05 bar (batch process), flow rate of the gaseous mixture between 50 - 72 ml/min and the adsorbent masses of 10, 15 and 20 g (fixed bed process). The time for the adsorption batch was 7 h and on the fixed bed was around 180 min. The results of this study showed that in batch adsorption process step with zeolite 13X is efficient and the mass of adsorbed CO2 increases with the increases pressure, decreases with temperature increases and rises due the increase of activation temperature adsorbent. In the batch process were evaluated the breakthrough curves, which were compared with adsorption isotherms represented by the models of Langmuir, Freündlich and Toth. All models well adjusted to the experimental points, but the Langmuir model was chosen in view of its use in the dynamic model does not have implications for adsorption (indeterminacy and larger number of parameters such as occurred with others) in solving the equation. In the fixed bed dynamic study with the synthetic gas mixture, 20 g of mass adsorbent showed the maximum adsorption percentage 46.7% at 40 °C temperature and 50 mL/min of flow rate. The model was satisfactorily fitted to the three breakthrough curves and the parameters were: axial dispersion coefficient (0.0165 dm2/min), effective diffusivity inside the particle (dm2/min 0.0884) and external transfer coefficient mass (0.45 dm/min). The breakthrough curve for CO2 in the process of pyrolysis of the sludge showed a fast saturation with traces of aerosols presents in the gas phase into the fixed bed under the reaction process

Estudo da influência da temperatura na degradação termoquímica da biomassa de avelós

The bio-oil obtained from the pyrolysis of biomass has appeared as inter-esting alternative to replace fossil fuels. The aim of this work is to evaluate the influence of temperature on the yield of products originating from the pyrolysis process of the powder obtained from the dried twigs of avelós (Euphorbia tirucalli), using a rotating cylinder reactor in laboratory scale. The biomass was treated and characterized by: CHNS, moisture, volatiles, fixed carbon and ashes, as well as evaluation of lignin, cellulose and hemicellulose, besides other instrumental techniques such as: FTIR, TG/DTG, DRX, FRX and MEV. The activation energy was evaluated in non-isothemichal mode with heating rates of 5 and 10 oC/min. The obtained results showed biomass as feedstock with potential for biofuel production, because presents a high organic matter content (78,3%) and fixed-carbon (7,11%). The activation energy required for the degradation of biomass ranged between 232,92 392,84 kJ/mol, in the temperature range studied and heating rate of 5 and 10°C/min. In the pyrolysis process, the influence of the reaction temperature was studied (350-520 ° C), keeping constant the other variables, such as, the flow rate of carrier gas, the centrifugal speed for the bio-oil condensationa, the biomass flow and the rotation of the reactor. The maximum yield of bio-oil was obtained in the temperature of 450°C. In this temperature, the results achieved where: content of bio-oil 8,12%; char 32,7%; non-condensed gas 35,4%; losts 23,8%; gross calorific value 3,43MJ/kg; pH 4,93 and viscosity 1,5cP. The chromatographic analysis of the bio-oil produced under these conditions shows mainly the presence of phenol (17,71%), methylciclopentenone (10,56%) and dimethylciclopentenone (7,76%)

Recuperação e purificação de quitosanases usando adsorção em leito expandido com streamline DEAE com modelagem e simulação usando redes neurais

Expanded Bed Adsorption (EBA) is an integrative process that combines concepts of chromatography and fluidization of solids. The many parameters involved and their synergistic effects complicate the optimization of the process. Fortunately, some mathematical tools have been developed in order to guide the investigation of the EBA system. In this work the application of experimental design, phenomenological modeling and artificial neural networks (ANN) in understanding chitosanases adsorption on ion exchange resin Streamline® DEAE have been investigated. The strain Paenibacillus ehimensis NRRL B-23118 was used for chitosanase production. EBA experiments were carried out using a column of 2.6 cm inner diameter with 30.0 cm in height that was coupled to a peristaltic pump. At the bottom of the column there was a distributor of glass beads having a height of 3.0 cm. Assays for residence time distribution (RTD) revelead a high degree of mixing, however, the Richardson-Zaki coefficients showed that the column was on the threshold of stability. Isotherm models fitted the adsorption equilibrium data in the presence of lyotropic salts. The results of experiment design indicated that the ionic strength and superficial velocity are important to the recovery and purity of chitosanases. The molecular mass of the two chitosanases were approximately 23 kDa and 52 kDa as estimated by SDS-PAGE. The phenomenological modeling was aimed to describe the operations in batch and column chromatography. The simulations were performed in Microsoft Visual Studio. The kinetic rate constant model set to kinetic curves efficiently under conditions of initial enzyme activity 0.232, 0.142 e 0.079 UA/mL. The simulated breakthrough curves showed some differences with experimental data, especially regarding the slope. Sensitivity tests of the model on the surface velocity, axial dispersion and initial concentration showed agreement with the literature. The neural network was constructed in MATLAB and Neural Network Toolbox. The cross-validation was used to improve the ability of generalization. The parameters of ANN were improved to obtain the settings 6-6 (enzyme activity) and 9-6 (total protein), as well as tansig transfer function and Levenberg-Marquardt training algorithm. The neural Carlos Eduardo de Araújo Padilha dezembro/2013 9 networks simulations, including all the steps of cycle, showed good agreement with experimental data, with a correlation coefficient of approximately 0.974. The effects of input variables on profiles of the stages of loading, washing and elution were consistent with the literature

Estudo da influência da temperatura na degradação termoquímica da biomassa de avelós (euphorbia tirucalli Linn)

The bio-oil obtained from the pyrolysis of biomass has appeared as inter-esting alternative to replace fossil fuels. The aim of this work is to evaluate the influence of temperature on the yield of products originating from the pyrolysis process of the powder obtained from the dried twigs of avelós (Euphorbia tirucalli), using a rotating cylinder reactor in laboratory scale. The biomass was treated and characterized by: CHNS, moisture, volatiles, fixed carbon and ashes, as well as evaluation of lignin, cellulose and hemicellulose, besides other instrumental techniques such as: FTIR, TG/DTG, DRX, FRX and MEV. The activation energy was evaluated in non-isothemichal mode with heating rates of 5 and 10 oC/min. The obtained results showed biomass as feedstock with potential for biofuel production, because presents a high organic matter content (78,3%) and fixed-carbon (7,11%). The activation energy required for the degradation of biomass ranged between 232,92 392,84 kJ/mol, in the temperature range studied and heating rate of 5 and 10°C/min. In the pyrolysis process, the influence of the reaction temperature was studied (350-520 ° C), keeping constant the other variables, such as, the flow rate of carrier gas, the centrifugal speed for the bio-oil condensationa, the biomass flow and the rotation of the reactor. The maximum yield of bio-oil was obtained in the temperature of 450°C. In this temperature, the results achieved where: content of bio-oil 8,12%; char 32,7%; non-condensed gas 35,4%; losts 23,8%; gross calorific value 3,43MJ/kg; pH 4,93 and viscosity 1,5cP. The chromatographic analysis of the bio-oil produced under these conditions shows mainly the presence of phenol (17,71%), methylciclopentenone (10,56%) and dimethylciclopentenone (7,76%)

Desenvolvimento de um secador spray para obtenção de pós finos de precursores de nióbio

This work presents a spray-dryer designed to oxalate-niobate precursors and suitable for the production of Niobium Carbide. The dryer was intended to produce powders of controlled particle size. First, the precursor is dissolved in water to produce a solution of known concentration and then it is atomized on the spray-dryer to produce the powder. This equipment consists of a 304 stainless steel chamber, 0.48 m x 1.9 m (diameter x length), with a conical shape at the lower portion, which is assembled on a vertical platform. The chamber is heated by three 4 kW electrical resistances. In this process, drying air is heated as it flows inside a serpentine surrounding the chamber, in contrary to more traditional processes in which the hot drying air is used to heat the component. The air enters the chamber at the same temperature of the chamber, thus avoiding adherence of particles on the internal surface. The low speed flow is concurrent, directed from the top to the bottom portion of the chamber. Powders are deposited on a 0.4 m diameter tray, which separates the cylindrical portion from the conical portion of the chamber. The humid air is discharged though a plug placed underneath the collecting tray. A factorial experimental planning was prepared to study the influence of five parameters (concentration, input flow, operation temperature, drying air flow and spray air flow) on the characteristics of the powders produced. Particle size distribution and shape were measured by laser granulometry and scanning electronic microscopy. Then, the powders are submitted to reaction in a CH4 / H2 atmosphere to compare the characteristics of spray-dried powders with powders synthetizided by conventional methods

Bio-óleo e biogás da degradação termoquímica de lodo de esgoto doméstico em cilindro rotativo

The objective of this study was to produce biofuels (bio-oil and gas) from the thermal treatment of sewage sludge in rotating cylinder, aiming industrial applications. The biomass was characterized by immediate and instrumental analysis (elemental analysis, scanning electron microscopy - SEM, X-ray diffraction, infrared spectroscopy and ICP-OES). A kinetic study on non-stationary regime was done to calculate the activation energy by Thermal Gravimetric Analysis evaluating thermochemical and thermocatalytic process of sludge, the latter being in the presence of USY zeolite. As expected, the activation energy evaluated by the mathematical model "Model-free kinetics" applying techniques isoconversionais was lowest for the catalytic tests (57.9 to 108.9 kJ/mol in the range of biomass conversion of 40 to 80%). The pyrolytic plant at a laboratory scale reactor consists of a rotating cylinder whose length is 100 cm with capable of processing up to 1 kg biomass/h. In the process of pyrolysis thermochemical were studied following parameters: temperature of reaction (500 to 600 ° C), flow rate of carrier gas (50 to 200 mL/min), frequency of rotation of centrifugation for condensation of bio-oil (20 to 30 Hz) and flow of biomass (4 and 22 g/min). Products obtained during the process (pyrolytic liquid, coal and gas) were characterized by classical and instrumental analytical techniques. The maximum yield of liquid pyrolytic was approximately 10.5% obtained in the conditions of temperature of 500 °C, centrifugation speed of 20 Hz, an inert gas flow of 200 mL/min and feeding of biomass 22 g/min. The highest yield obtained for the gas phase was 23.3% for the temperature of 600 °C, flow rate of 200 mL/min inert, frequency of rotation of the column of vapor condensation 30 Hz and flow of biomass of 22 g/min. The non-oxygenated aliphatic hydrocarbons were found in greater proportion in the bio-oil (55%) followed by aliphatic oxygenated (27%). The bio-oil had the following characteristics: pH 6.81, density between 1.05 and 1.09 g/mL, viscosity between 2.5 and 3.1 cSt and highest heating value between 16.91 and 17.85 MJ/ kg. The main components in the gas phase were: H2, CO, CO2 and CH4. Hydrogen was the main constituent of the gas mixture, with a yield of about 46.2% for a temperature of 600 ° C. Among the hydrocarbons formed, methane was found in higher yield (16.6%) for the temperature 520 oC. The solid phase obtained showed a high ash content (70%) due to the abundant presence of metals in coal, in particular iron, which was also present in bio-oil with a rate of 0.068% in the test performed at a temperature of 500 oC.

Utilização de membranas no pós-tratamento de esgotos para reuso do permeado e aproveitamento do concentrado

The use of membrane filters in the post-treatment of sewage has been increasingly employed to obtain water quality, applicable to various forms of reuse. Despite the advantages presented using the permeate membranes, such as saving water and reducing water pollution, the concentrate generated in the process ends up being an inconvenience to the deployment of this technology due to lack of sustainable solutions for their management. Thus, the main objective of this research was to evaluate the use of membranes for microfiltration, ultrafiltration, nanofiltration and reverse osmosis concentrated in agriculture, using it as liquid fertilizer. The permeated membranes were also assessed in order to identify activities in which they could be reused. Five configurations were established from four types of membranes, so that each configuration represents a different system. The tests were conducted in batch mode, with triplicate for each configuration. The results indicated that permeated the microfiltration and ultrafiltration can be used in urban areas, in non-potable uses. Have the nanofiltration permeate can be reused in the industry, replacement cooling towers, and other non -potable uses required in the manufacturing unit. The permeate obtained in reverse osmosis met the intended uses for nanofiltration as well as the standards required for boiler feed, adding alkalizing being required to raise the pH to the recommended value. Concentrates generated in nanofiltration and reverse osmosis can be availed as liquid fertilizer in agriculture, but they must be diluted in the irrigation water, in order to adjust the salt concentration allowed for the least tolerant crops patterns

Educação científica no contexto pós-ontológico: por uma concepção plural de conhecimento e educação

The development of this work arises from the research of sociological and philosophical characters contemplating also other approaches which aims to answer the followingquestions: what is the responsibility of science teaching for the image one has about science? ; which scientific education should be designed for nowadays? . After considering the assumptions brought along by rationalism and the criticisms to the illuminist model proposed by sociology and philosophy of science, as well by the biology of the knowing process, going through discussions concerning post-modernity issues, one is given to understand that the image of science has become the central point of discussion in the last hundred years, including what concerns the area of science teaching, and that practically none of those discussions really reached natural science classes indeed. We adopt the term postontological to characterize the recent proposals on philosophy and sociology, because we evaluate that this term allows a better identification of the scientific realism crisis, which supports the existence of an ontological domain which science, and only science, is able to understand. One notices that the general public is not aware of those discussions, mainly if they are science teachers and students. So we believe that discussing the logic in which science is structured, the new understandings concerning the scientific undertaking, especially those of an externalist character, and the relationship between science and society, all of this contributes to build up a science teaching which contemplates a reflective contribution, besides allowing the inclusion of the study of other epistemologies in the educational practice. We argue that a revisionist posture seems to be the most appropriate for the contemporary scientific education, contemplating, besides the teaching of the usual science contents, discussions on the issues involving that knowledge, as well as respecting epistemologies alternative to the modern Western scientific one, in order one can work on the perception of local knowledge generated from other epistemological bases. We describe here practical activities we did involving teachers (short-term courses) and high-school students in an inland school in the Rio Grande do Norte state, in Brazil, as a way to demonstrate the possibility of interventions which can take those conceptions, discussions and changes to the classroom

A formação pós-graduada em ensino de ciências naturais e matemática de docentes do IFRN: implicações na atuação docente

This research part of the educational context of the Federal Rio Grande do Norte, through the resumption of legal frameworks that characterize it as an institution belonging to the Federal Network of Professional Education and Technology Brazilian, with a focus on continued education policies for the servers who work there specifically teachers, especially those who have their work in the Teaching of Natural Science and Mathematics. To do this the cut in an agreement between the IFRN and UFRN PPGECNM through the professional master's degree Teaching of Natural Sciences and Mathematics. This agreement as we have research collaborators 08 master teachers who graduated in the period 2004 to 2010, so we undertook a qualitative and quantitative research aimed to conduct the study in general terms of description and analysis of the impacts caused by the formation of masters IFRN in PPGECNM UFRN, taking into account the production of the same academic (dissertation), his performance in the context of the institution and the historical, social, economic and political aspects involved, and also meet the guidelines of the project at the Observatory in 2008 - MEC / CAPES / BSD-P. We used the theoretical options methodological elements of Comprehensive Interview and multireferentiality, our data collection instrument was the main interview, we also performed the analysis of dissertations by lecturers and teachers featured, from the specific descriptors used in catalogs USP / IFUSP (1992, 1996) and UNICAMP / FE / CEDOC (1998) and by other researchers. In analyzing and understanding the speech of the interviewees were able to identify the implications of teacher education in the school context, the motivation to seek the Master; how was the construction of the object of study of the educational product and its use in teaching practice and intervention, the question of the role of master teachers in the school environment to the post master taking into account changes in professional performance and influence in the working groups, how does the use of research and investigation in the classroom after training and between training and educational quality in the context of IFRN. In reading and analysis of the dissertations were able to identify the main focus and under-explored thematic focus as well as the theoretical methodological references. At the end of the research developed a product that could be used for technical analysis studies and assessment in quantitative terms the results achieved by the master teachers IFRN through his training in PPGECNM UFRN

Referenciação anáforica: um estudo de produções textuais no ensino fundamental

Esta pesquisa trata da referenciação ocorrida pelas anáforas diretas e indire-tas em produções textuais de alunos do Ensino Fundamental. Como elemento pri-mordial de nossas investigações, ancoramo-nos na referenciação e estudos da aná-fora no âmbito da Lingüística Textual como fazem Mondada e Dubois (2003); KOCH (2003) e Marcuschi (2005). De acordo com estudos já realizados e envolvidos com a temática, defendemos a noção de referenciação como sendo um processo de cons-trução de sentidos que se realiza no discurso, isto é, em atividades interativas entre os sujeitos exigindo, portanto, uma ação colaborativa entre os interlocutores. Nesse aspecto, a interação precisa existir, visto que os referentes de um termo anafórico nem sempre se encontram na superfície textual; muitas vezes, são construídos a partir de uma representação ou modelo mental disponível na memória discursiva. Nessa perspectiva, procuramos analisar o processo de referenciação construído a partir de anáforas diretas e indiretas identificando as estratégias utilizadas em textos produzidos em situações de sala de aula. Dizemos que a anáfora direta, de modo geral, é definida pela relação de correferencialidade estabelecida entre o anafórico e seu antecedente, enquanto a anáfora indireta é vista como uma estratégia referenci-al de associação, sem referente explícito, tendo que se esforçar para estabelecer a continuidade referencial no texto e para isso utiliza-se da ativação (referenciação mental) de elementos novos e não de uma reativação de referentes já conhecidos, o que constitui um processo de referenciação implícita. Para alcançarmos nosso obje-tivo, utilizamos como subsídio teórico, o processo de informação na memória cogni-tiva, a referência e estudos da anáfora no âmbito da Lingüística Textual. O corpus deste trabalho constitui-se de sessenta textos escritos por alunos de 7ª série (atual 8º ano), dentre os quais analisamos o processo de referenciação ocasionado pelas anáforas diretas e indiretas em doze desses textos. Considerando os dados analisa-dos, dentre os tipos de anáforas estudados, constatamos que houve preponderância no uso das anáforas diretas, destacando-se entre elas a anáfora direta correferencial co-significativa, com maior manifestação no uso das retomadas diretas por pronomi-nalização

Processos de construção do sentido na esquizofrenia: uma perspectiva cognitiva da linguagem

There is still a lot to be said about the relationship between culture, cognition and language. Within an embodied cognition perspective to language, it may be understood that the senses generated and used in discourse are built and negotiated not only linguistically, since they also involve stereotypes, schemes, frames, etc. These cognitive structures, in turn, would emerge from subjects experiences and interactions with a sociohistorically constituted environment. With that in mind, what would happen if someone had an altered view in the perception of such environment? The objective of this master s thesis was to understand the process of meaning construction, aiming at the activation of frames, in the discourse of people who have been diagnosed as schizophrenic and have been hospitalized, that is, individuals who have their socio-environmental perception affected. With that aim in mind, a speech corpus was generated with three schizophrenic patients from Professor Severino Lopes Psychiatric Hospital. The data were collected and analyzed qualitatively, based on the theoretical and analytical premises of Cognitive Linguistics, more specifically, of Simulation Semantic perspective. Therefore, it was possible to identify aspects related to meaning construction processes in the discourse of schizophrenic patients, understanding that language is integrated with cognition and culture. Therefore, the alteration in the way experiences are perceived by schizophrenic patients affect the linguistic production of these subjects. Finally, if we take into consideration that the mental disturbance caused by schizophrenia results in a change in perception of reality by these individuals, we can infer an implication of such factors in language and, subsequently, the interference of such issues in the meaning construction processes in the discourse of patients diagnosed with schizophrenia

Processos cognitivos que operam na construção da referência: uma análise das produções textuais elaboradas na EaD - UFRN

Beneath the theoretical assumptions of Cognitive Linguistics contemporary, we analyze the cognitive processes underlying the construction of the reference in the text. To do so, we choose as corpus the written textual productions of undergraduates at the Department of Distance Education/UFRN provided in sections of responses of presential evaluation activities and activities in the Moodle virtual ambience. These activities and texts were produced in the discipline of Reading, Interpretation and Textual Production taught in the courses of Chemistry, Physics, Mathematics, Biology and Geography we monitor during the period of 2008.1 to 2010.1. Through the analysis of discursive productions, it was evident that the construction of the reference is made by means of the activation and manipulation of information acquired through our perceptual and social experiences. Thus, we confirm the cognitive assumption that the linguistic clues available in the texts of the activities serve as guides towards cognitive domains that activate the process of building reference

A construção de modelos situacionais no padrão discursivo narrativa em quadrinhos

The object of this study is the construction of situation models in the discourse pattern comic book narrative, and sits in the field of Cognitive Linguistics. Its main foundations are the notions of embodied mind (LAKOFF; JOHNSON, 1999), mental simulation (BARSALOU, 1999), discourse pattern (DUQUE; COSTA, 2012) and situation models (ZWAAN, 1999). I stem from the hypothesis that the process of meaning construction in narratives is attached to the simulation of space, of time and of the characters goals and actions within the story world, dimensions which make up the situation models elaborated by the reader. The simulation of these experiences during discourse processing originates from the fact of it having an embodied and cultural basis, i.e., upon being confronted with the clues found in the narrative, the cognitive structures that make up the reader s personal and social memories are triggered and make it possible to activate information which in turn refer to his/her physical and social experiences, built up in the environment in which he/she lives. As regards comic book narratives, the construction of situation models is closely related to the recurring activation of certain cognitive structures originating from graphic resources that are typical of that discourse pattern. These conclusions were drawn from the data analysis taken from the work Palestina (SACCO, 2003; 2004; 2011)

O processamento discursivo e suas bases corpóreas estratégias cognitivas de alunos da Educação de Jovens e Adultos na compreensão de narrativas

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