Sistema Híbrido de Inferência Baseado em Análise de Componentes Principais e Redes Neurais Artificiais Aplicado a Plantas de Processamento de Gás Natural

Nowadays, where the market competition requires products with better quality and a constant search for cost savings and a better use of raw materials, the research for more efficient control strategies becomes vital. In Natural Gas Processin Units (NGPUs), as in the most chemical processes, the quality control is accomplished through their products composition. However, the chemical composition analysis has a long measurement time, even when performed by instruments such as gas chromatographs. This fact hinders the development of control strategies to provide a better process yield. The natural gas processing is one of the most important activities in the petroleum industry. The main economic product of a NGPU is the liquefied petroleum gas (LPG). The LPG is ideally composed by propane and butane, however, in practice, its composition has some contaminants, such as ethane and pentane. In this work is proposed an inferential system using neural networks to estimate the ethane and pentane mole fractions in LPG and the propane mole fraction in residual gas. The goal is to provide the values of these estimated variables in every minute using a single multilayer neural network, making it possibly to apply inferential control techniques in order to monitor the LPG quality and to reduce the propane loss in the process. To develop this work a NGPU was simulated in HYSYS R software, composed by two distillation collumns: deethanizer and debutanizer. The inference is performed through the process variables of the PID controllers present in the instrumentation of these columns. To reduce the complexity of the inferential neural network is used the statistical technique of principal component analysis to decrease the number of network inputs, thus forming a hybrid inferential system. It is also proposed in this work a simple strategy to correct the inferential system in real-time, based on measurements of the chromatographs which may exist in process under study

Diagnóstico regional do processo de queijo coalho comercializado em Natal/RN

Coalho cheese is a typical product of the Northeastern Brazil, which is consumed both raw and cooked. The present work aimed to study the characteristics of artisanal and industrial processes in the production of coalho cheese sold in Natal / RN in order to evaluate its quality and consumer s profile. Four artisanal cheeses plants were monitored and a questionnaire was sent to different cheese industries. Besides this, eight cheese samples (four artisanal and four industrial) were evaluated in regard to the microbiological quality, physical-chemical and sensory attributes. The sensory acceptance was evaluated by using 108 non-trained panelists by using the hedonic scale. The consumer s profile survey was applied to 400 consumers of coalho cheese. The lack of hygiene control was detected at the artisanal cheese production, which uses raw milk as its raw material. Research has shown that the industrialized cheeses are made from pasteurized milk provided by their own production or by a third party, as observed in cheese making dairies. In general, the results indicate variation in the manufacturing process of coalho cheese, which results in the lack of product standardization. Regarding the physical-chemical analysis, most artisanal and industrial samples presented moisture content between 36 and 40 %, classified as medium moisture cheese, which is the only parameter that showed no significant difference (p>0.05). However, the water activity (Aw), pH and acidity results differed significantly. All artisanal samples showed coliform contamination at 35 °C, which confirms the poor hygienic conditions. In regard to coliforms at 45 °C, 75 % of artisanal coalho cheese samples had value higher than 103 MPN / g, a value above the lawful limits determined by RDC nº 12. Fifty percent of industrial coalho cheese samples showed coagulase-positive Staphylococcus values above the limit allowed by the RDC nº 12, indicating poor handling. The sensory evaluation revealed that the taste was the only parameter that showed significant difference, and this difference was only between two industrial brands. The consumer s survey showed that the coalho cheese flavor is the most important reason for buying this kind of cheese. Although coalho cheese is mainly bought in supermarkets, open street markets and country shops are still important selling points. It is concluded that there is no coalho cheese standardization in the RN state, which leads to variations in physical-chemical and sensory attributes. Moreover, it is necessary greater hygiene control in the production and handling procedures of coalho cheese.

Recuperação de fósforo por cristalização de estruvita

This study investigated the influence of the molar ratio, the phosphorus initial concentration, the mixture gradient, mixing time, pH and the secondary nucleation on struvite s crystallization in synthetic water in batch reactors. The study was divided into two stages. The first investigated struvite s crystallization at different Mg:N:P molar ratios and at different initial concentrations of magnesium, nitrogen and phosphorus. It was also evaluated the importance of secondary nucleation on the struvite s crystallization. In the second, five parameters were tested to evaluate their influence on the struvite s crystallization, which were: Mg:N:P molar ratio, initial concentration of phosphate, mixing time, mixture gradient and pH. The best conditions for struvite s crystallization were: Mg:N:P = 1,3:1:1 molar ratio; mixture gradient = 60 rpm, pH = 10.0, mixing time = 5 minutes and high initial concentrations of the constituent ions of struvite. Furthermore, the use of struvite crystals as seed influenced positively on the struvite s crystallization

O uso pedagógico de uma seqüência didática para a aquisição de algumas idéias relacionadas ao conceito de números complexos

The aim of the present work is to contribute to the teaching-learning process in Mathematics through an alternative which tries to motivate the student so that he/she will learn the basic concepts of Complex Numbers and realize that they are not pointless. Therefore, this work s general objective is to construct a didactic sequence which contains structured activities that intends to build up, in each student s thought, the concept of Complex Numbers. The didactic sequence is initially based on a review of the main historical aspects which begot the construction of those numbers. Based on these aspects, and the theories of Richard Skemp, was elaborated a sequence of structured activities linked with Maths history, having the solution of quadratic equations as a main starting point. This should make learning more accessible, because this concept permeates the students previous work and, thus, they should be more familiar with it. The methodological intervention began with the application of that sequence of activities with grade students in public schools who did not yet know the concept of Complex Numbers. It was performed in three phases: a draft study, a draft study II and the final study. Each phase was applied in a different institution, where the classes were randomly divided into groups and each group would discuss and write down the concepts they had developed about Complex Numbers. We also use of another instrument of analysis which consisted of a recorded interview of a semi-structured type, trying to find out the ways the students thought in order to construct their own concepts, i.e. the solutions of the previous activity. Their ideas about Complex Numbers were categorized according to their similarities and then analyzed. The results of the analysis show that the concepts constructed by the students were pertinent and that they complemented each other this supports the conclusion that the use of structured activities is an efficient alternative for the teaching of mathematics

Cartografias do desejo em asfalto selvagem - engraçadinha, seus amores e seus pecados: humor, erotismo e o pornógrafo no romance rodrigueano

Trata-se nesta dissertação de estabelecer, partindo do pensamento contemporâneo francês da linha deleuziana e guattariana, sobretudo, uma analítica do desejo capaz de reconfigurar o romance de Nelson Rodrigues, Asfalto selvagem: Engraçadinha, seus amores e seus pecados, desterritorializá-lo em relação à tradição crítica e estética, fundada no paradigma realista-naturalista enraizado no pensamento literário brasileiro, especificamente no século XX. Movemo-nos por discussões sobre o autor e sobre o romance, empreendidas por Rolnik, interlocutora de Guattari, o qual está ligado aos novos paradigmas estéticos, à questão da produção de subjetividades, à micropolítica, às multiplicidades e às minorias. Buscamos contribuir para esse redimensionamento, colocando-nos na perspectiva cartográfica e rizomática para surpreender, em Asfalto, seus processos de subjetivação, incidindo sobre as singularidades selvagens, considerando os conceitos de Foucault, aplicados à construção literária enquanto espaço heterotópico, configurando a experiência do fora, como princípios estéticos. Veremos que as personagens, com foco em Engraçadinha, funcionam, como pequenas máquinas desejantes, Corpos sem Órgãos, moléculas desestabilizando as formações molares. Destarte, Nelson Rodrigues, na perspectiva da produção autoral, torna-se o pornógrafo, o literato iterador, como agenciador de uma palavra perversa, para além dos dogmas, da cena romantizada, originando, em sua poética, a revelação da obs-cena, a obscenidade, como crítica às instituições falidas. Trazemos, nesse sentido, referências de Bataille, quanto ao que na atividade estética se relaciona com o excedente da visão, relacionados ao espaço tático-ótico, concepção deleuziana referentes ao corpo-linguagem, pornografia, pornógrafo, narrativas abomináveis. Acompanhamo-nos, pois, dos conceitos da problemática da diferença e da alteridade, repercutindo na larvaridade, nas afecções, que abrem vias comunicantes com fenômenos extremos, atuantes em torno do mesmo e do outro, trazendo a rizomaticidade do mal e da monstruosidade para a construção estética de Asfalto selvagem, vistos sob a ótica de Bataille, Deleuze, Baudrillard, em ensaios que rompem o olhar estrutural em torno da obra e oferecem subsídios para a construção de uma cartografia outra, o território do ficcional, habitado por um povo por vir, na perspectiva tratada por Deleuze e por Blanchot

Avaliação da eficácia de selante ionomérico modificado por resina e escovação dentária na preservação de cárie oclusal

The purpose of this study was to evaluate the effectiveness during a twelve-month period, of resin-modified glass ionomer (Vitremer@) used as fissure sealants compared to supervised teeth brushing in the prevention of oclusal caries in permarient molars of pubIlc school children from 5 to 7 years of age. A total of 91 children participated in the study, being randomly divided up into three groups of investigation: group with sealant (n=31), group of supervised brushing (m=30), and control gorup (n=30). After 12 months, a total of 28.5% of tosses in the sample of 26 children was registered, and although there wasn t a significant diference between these losses and the groups studles (p = 0.6355), there was a considerable reduction in the sample. The results showed that none of the independentIy studied variables (present caries experience, biofilm, bleeding, sealant retention, position of the tooth in the arch, and sex) interfered in the final results, and that there was no significant difference between applying the sealant in question, perfornling supervised dental brushing, or not intervening at alI (p=0.542). These results could have been a consequence of the limitations found alI through the study, especially relating to the losses occurred because of school evasion, transfer, or because of the accident in the Marise Paiva Municipal School, Keeping students away for approximately one semester, so tht a new reseach had to be developed sos as to better clarify the effects among the treatments done there

Avaliação clínica da relação entre o índice de placa, índice gengival, alinhamento dental, mucosa ceratinizada, tipo de periodonto e distúrbios oclusais com a ocorrência de recessão gengival

This study clinically evaluated the relationship of gingival recessions with the periodontal index of gingival and plaque, dental alignment, keratinized mocous, type of periodontal, and occlusal disorders. Study participants were individuals aged between 19 and 33 years. The evaluations were performed by using questionnaires and clinical examinations. In subjects examined, the teeth were assessed and divided into groups (Molars, premolars, canines and incisors). The gingival recession were measured in the central region of the teeth and individuals were subject to disclosure to the plate and observing the poll of plaque and gingival index, respectively. 558 teeth were examined, with 24.1%, 135 had gingival recession greater than or equal to 1mm. Through the combination of tests used to evaluate the average of the recession and its relationship with the variables studied, we observed that the degree of recession of the elements assessed dental showed, almost for the most part, when higher values associated with the index plaque (p = 0.101), Gingival Index (p = 0.053), dental alignment (p = 0.962), width of keratinized mocous (p = 0.004) and type of periodontium (p = 0.033), however statistically significant difference could only be considered when related the recessions in the keratinized mocous and the type of the periodontium. Although we identify, when we evaluate the whole set of teeth that occlusal disturbances (p = 0.002) were more strongly associated with cases of gum recession that the gingival index (p = 0.006), however, these two conditions were correlated with the cases of recession, contributing to its occurrence

Eficácia do cimento de ionômero de vidro como selante oclusal sobre a paralisação de lesões cariosas em dentina

Dental caries consists in a multifactorial and dynamic process. The knowledge of the ionic interactions among dental tissues and dental biofilm make possible its understanding as a process that can be stopped. Recently, the use of sealants have lost its function as preventive agent and passed to be argued as a possible therapeutical agent. This happens by hindering the substratum flow to the lesion inner and, therefore, controls the advance of the process. This study aimed to evaluate glass ionomer cement as a not invasive technique of treatment in occlusal caries without clinical cavitation, but with dentinal involvement. The research was accomplished using a controlled clinical trial with two groups (experimental and control) in 38 subjects (8-18 years) with 51 molars. The teeth of the experimental group were sealed with glass ionomer cement (Vidrion-R, S.S.White, Juiz de Fora, Brazil) and the molars control did not suffer intervention. The experimental group was followed by a year and the control by 8 months due the progression of the carious injury. Both groups were reevaluated to each 4 months with the use of clinical, radiographic and laser fluorescence (DIAGNOdent®) examination. The analysis of the clinical evaluation did not observe a significant difference between experimental and control groups. However, analysis with radiographic and laser fluorescence (DIAGNOdent®) examination observed a significant difference (p> 0,05) between groups, demonstrating a wors condition to the group without intervention. The results suggest that glass ionomer cement as sealant can be efficient to paralyze dentinal caries without clinical cavitation

Cisto dentígero: estudo epidemiológico, correlação clinicopatológica e caracterização de uma possível variante inflamatória

The aim of this study was to evaluate the clinical and pathological features of cases diagnosed as dentigerous cyst by the Department of Oral Pathology, School of Dentristy at the Federal University of Rio grande do Norte, attempting the possible correlation between histomorphological findings and epidemiological data contained at the files of the patients, in order to define a suggested variation of lesion named inflammatory dentigerous cyst. It was verified that dentigerous cyst are more frequently present in the earfy three decades of life, with the majority of cases occuring in the second decade (40,740/0 ), and also male (57,41%) and white patients (68,52%) were most affected. In relation to anatomic site, the dentigerous cyst was more prevalent at anterior maxila and posterior mandible, showing, usually, a slow growth pattem. The majority of lesions were asymptomatic and the radiographic observed was frequently na unilocular radiolucency. In regard to the histomorphological analysis, it was noticed that the lesions showed commonly a thin epithelium, with a capsule of fibrous connective tissue, richly vascularized and collagenized with an intense mononuclear inflammatory infiltrate. Finally, clinicopathological was performed and it was find out that cysts that showed a thick epithelium, with a high degree of vascularization and collagenization, intense inflammatory infiltrate in the cystic capsule, were located in the pre-molares region, in patients under 12 years old and the majority showing painfull sintomatology, properly, compatible with inflammatory dentigerous cyst. The findings of the present study indicate that, probably, there is a variant of the dentigerous cyst, and therefore, we suggest the denomination inflammatory follicular cyst for this entity

Resposta celular Th1 /Th2 na doença periodontal experimental, em ratos: um estudo imuno-histoquímico

Host response plays a major role in the pathogenesis of periodontal disease. Mediators such as inflammatory cytokines which are secreted during the immune response to bacterial challenges have ambiguous functions that may or may not lead to protection of the attacked tissue. In this context, experimental evidence suggests that T-helper 1 (Th-1) and T-helper 2 (Th-2) mediated responses are potentially important during the disease process. The aims of this study therefore were to further clarify the role played by Th2 cells during different time points of the active phase of periodontal disease, as well as, to investigate whether there was any evidence of a Th1 response in the periodontal disease microenvironment. Experimental periodontitis was induced in 30 Wistar male rats by placing cotton ligatures around the mandibular first molars. The rats were then randomly divided into two groups. Group1 (G1=15) and Group 2 (G2=15). In G1 the ligatures were maintained for 2 days, whereas in G2 the ligatures were left for 15 days, a time point that corresponds to the advanced stage of periodontal disease The contra-lateral teeth served as controls (no ligatures). Immunohistochemical investigation for the presence in gingival tissue of Th2 specific transcription factor (GATA3) and the subunit of the IFN-γ receptor was carried out after the disease induction period. Light microscopy analysis revealed a decrease in the expression of GATA-3 as bone loss progressed. On the other hand, although IFN-γ R1 was detected at an early stage of the active phase of disease its expression remained unaltered during the remaining period of the study. These results indicate that the Th2 response have a protective role during the pathogenesis of periodontal disease and that the progression of the periodontal disease is related with the unbalance of the responses Th1/Th2

Os agentes funerários e a morte: o cuidado presente diante da vida ausente

The present time is marked by the art of escape from death, which has become synonymous with failure, its exposure has become intolerable and the care of the dead body were assigned to third parties who market this practice through services and products that shape the market undertaker. In this context, in which death is an object of study, has arisen funeral officers, as professionals dealing with a dead body, with the pain of relatives and their reactions, often being the first to have contact with the death scene. As professionals in the health area, the morticians also deal with death. The first attempt to prevent the arrival of death, funeral officers already has begun their work routine from there. Death and its surrounding part of their profession. What about those professionals whose work demands as a feared and denied by society? This study aims to understand the intents, meanings and implications for the mortician to deal with death in their daily work in order to focus renewed attention to the care of these professionals. To this end, it was carried out a qualitative research grounded in the theoretical framework of Gadamerian hermeneutics for production and interpretation of narratives. It was used two methodological strategies for data collection: in-depth interview with script and workshop with the use of "scenes". Research participants were nine morticians funeral of two funeral agencies of the city of Natal. It was possible to detect the presence of the social imaginary of interdiction on the theme of death from living with feelings of his presence daily, from the need of respondents to naturalize their contacts with death, a requirement of their office to deal with the difficulties of manipulating body fluids and odors, sometimes in a state of decomposition; allied to wishes to achieve the goal of delivering to family-customers a "embellished" body for the final farewell. Being a mortician, in addition to not being a professional motivation, involves facing difficulties related to heavy routine work, low salaries, unprofitable work materials and equipments, besides having to deal with the social gaze that devalues the profession. In turn, they also deal with the pain coming especially from contact with family members, either when they are targets of these feelings of anger, whether they identify with the pain of the bereaved ones. On the other hand, when the recognition and gratitude of the families occur, they find meaning and beauty in their profession of caring for the dead body. The present study by giving voice to morticians has become possible to understand better their profession, the pain that surrounds and care needs of these workers. Finally, it has argued that the mortician may be recognized as a care professional for the way exercising caution with the dead body and their families.

Síntese e caracterização de látices acrílicos reticulados com (1,6-diacrilato propoxilato hexanodiol) via polimerização em emulsão

Latices based on acrylic acid and ethyl methacrylate, crosslinked with 1,6‐propoxylate‐hexanodiol diacrylate were synthesized via emulsion polymerization with different monomeric compositions. The resultant latices were thickened with different NaOH/(acrylic acid) molar ratios and were characterized by titrimetry, zeta potential measurements, turbidimetry, and capillary viscometry. Intrinsic viscosity was determined for an uncrosslinked copolymer, using toluene as solvent. All the latices were coagulated with NaCl and washed with water at 60°C analyzed by FTIR spectrophotometry, in order to characterize functional groups from the copolymer and crosslinking agent.

Alquilação redutiva da quitosana a partir do glutaraldeído e 3-amino-1-pr

Chitosan derivatives were prepared by reductive alkylation using glutaraldehyde and 3-amino-1-propanol. The reducing agent used was the sodium borohydride. Tests of solubility, stability and viscosity were performed in order to evaluate these parameters effects in the reaction conditions (molar ratio of the reactants and presence of nitrogen in the reaction system). The molecular structure of commercial chitosan was determined by infrared (IR) and hydrogen nuclear magnetic resonance spectroscopy (1H NMR). The intrinsic viscosity and average molecular weight of the chitosan were determined by viscosimetry in 0.3 M acetic acid aqueous solution 0.2 M sodium acetate at 25 ºC. The derivatives of chitosan soluble in aqueous acidic medium were characterized by 1H NMR. The rheological behavior of the chitosan and of the derivative of chitosan (sample QV), which presented the largest viscosity, were studied as a function of polymer concentration, temperature and ionic strength of the medium. The results of characterization of the commercial chitosan (the degree of deacetylation obtained equal 78.45 %) used in this work confirmed a sample of low molar weight (Mv = 3.57 x 104 g/mol) and low viscosity (intrinsic viscosity = 213.56 mL/g). The chemical modification of the chitosan resulted in derivatives with thickening action. The spectra of 1H NMR of the soluble derivatives in acid aqueous medium suggested the presence of hydrophobic groups grafted into chitosan in function of the chemical modification. The solubility of the derivatives of chitosan in 0.25 M acetic acid aqueous solution decreased with increase of the molar ratio of the glutaraldehyde and 3-amino-1-propanol in relation to the chitosan. The presence of nitrogen and larger amount of reducing agent in reaction system contributed to the increase of the solubility, the stability and the viscosity of the systems. The viscosity of the polymeric suspensions in function of the shear rate increased significantly with polymer concentration, suggesting the formation of strong intermolecular associations. The chitosan presented pseudoplastic behavior with the increase in polymer concentration at a low shear rate. The derivative QV presented pseudoplastic behavior at all concentrations used and in a large range of shear rate. The viscosity of chitosan in solution decreased with an increase of the temperature and with the presence of salt. However, there was an increase of the viscosity of the chitosan solution at higher temperature (65 ºC) and ionic strength of the medium which were promoted by hydrophobic associating of the acetamide groups. The solutions of the chitosan derivatives (sample QV) were significantly more viscous than chitosan solution and showed higher thermal stability in the presence of salt as a function of the hydrophobic groups grafted into chitosan backbone

Caracterização de látices acrílicos em função da neutralização de seus grupos carboxilas

Latexes based on acrylic acid, acrylamide, ethyl methacrylate, and ethyl acrylate were synthesized via emulsion polymerization with different monomer compositions. The resultant latices were thickened with different molar ratios of NaOH to acrylic acid and were analyzed in terms of acid‐basis titrimetry, turbidimetry, rheology, and tensiometry. Titrimetry, turbidimetry, and rheometry were used to analyze factors such as carboxyl group availability and particle solubilization, tensiometry monitoring the influence of carboxyl neutralization on polymer‐surfactant interactions. For the acrylic acid content used in this work (20 wt%), the results indicated that as carboxyl groups distribution became more homogeneous, the process of latex thickening became more effective

Obtenção de diesel verde por craqueamento termocatalítico de óleo de buriti (Mauritia flexuosa L.) sobre materiais nanoestruturados do tipo LaSBA-15

In order to obtain a biofuel similar to mineral diesel, lanthanum-incorporated SBA- 15 nanostructured materials, LaSBA-15(pH), with different Si/La molar ratios (75, 50, 25), were synthesized in a two-steps hydrothermal procedure, with pH-adjusting of the synthesis gel at 6, and were used like catalytic solids in the buriti oil thermal catalytic cracking. These solids were characterized by X-ray fluorescence (XRF), powder X-ray diffraction (XRD), thermogravimetric analysis (TG/DTG), infrared spectroscopy (FTIR), nitrogen porosimetry and ethanol dehydration, aiming to active sites identify. Taken together, the analyses indicated that the synthesis method has employed to obtain materials highly ordered mesostructures with large average pore sizes and high surface area, besides suggested that the lanthanum was incorporated in the SBA-15 both into the framework as well as within the mesopores. Catalytic dehydration of ethanol over the LaSBA-15(pH) products has shown that they have weak Lewis acid and basic functionalities, indicative of the presence of lanthanum oxide in these samples, especially on the La75SBA-15(pH) sample, which has presented the highest selectivity to ethylene. The buriti oil thermal and thermal catalytic cracking, realized from the room temperature to 450 ºC in a simple distillation system, has allowed obtaining two liquid fractions, each consisting of two phases, one aqueous and another organic, organic liquid (OL). The OL obtained from first fractions has shown high acid index, even in the thermal catalytic process. One the other hand, OL coming from second ones, called green diesel (GD), have presented low acid index, particularly that one obtained from the thermal catalytic process realized over LaSBA-15(pH) samples. The acid sites presence in these samples, associated to their large average pore sizes and high surface areas, have allowed them, especially the La75SBA-15(pH), to present deoxygenating activity in the buriti oil thermal catalytic cracking, providing an oxygenates content reduction, particularly carboxylic acids, in the GD. Furthermore, the GD comes from the second liquid fraction obtained in the buriti oil thermal catalytic cracking over this latest solid sample has shown hydrocarbons composition and physic-chemical properties similar to that mineral diesel, beyond sulfur content low