Avaliação e modelagem da absorção de H2S do gás natural em coluna de leito estagnado

Natural gas, although basically composed by light hydrocarbons, also presents contaminant gases in its composition, such as CO2 (carbon dioxide) and H2S (hydrogen sulfide). The H2S, which commonly occurs in oil and gas exploration and production activities, causes damages in oil and natural gas pipelines. Consequently, the removal of hydrogen sulfide gas will result in an important reduction in operating costs. Also, it is essential to consider the better quality of the oil to be processed in the refinery, thus resulting in benefits in economic, environmental and social areas. All this facts demonstrate the need for the development and improvement in hydrogen sulfide scavengers. Currently, the oil industry uses several processes for hydrogen sulfide removal from natural gas. However, these processes produce amine derivatives which can cause damage in distillation towers, can cause clogging of pipelines by formation of insoluble precipitates, and also produce residues with great environmental impact. Therefore, it is of great importance the obtaining of a stable system, in inorganic or organic reaction media, able to remove hydrogen sulfide without formation of by-products that can affect the quality and cost of natural gas processing, transport, and distribution steps. Seeking the study, evaluation and modeling of mass transfer and kinetics of hydrogen removal, in this study it was used an absorption column packed with Raschig rings, where the natural gas, with H2S as contaminant, passed through an aqueous solution of inorganic compounds as stagnant liquid, being this contaminant gas absorbed by the liquid phase. This absorption column was coupled with a H2S detection system, with interface with a computer. The data and the model equations were solved by the least squares method, modified by Levemberg-Marquardt. In this study, in addition to the water, it were used the following solutions: sodium hydroxide, potassium permanganate, ferric chloride, copper sulfate, zinc chloride, potassium chromate, and manganese sulfate, all at low concentrations (»10 ppm). These solutions were used looking for the evaluation of the interference between absorption physical and chemical parameters, or even to get a better mass transfer coefficient, as in mixing reactors and absorption columns operating in counterflow. In this context, the evaluation of H2S removal arises as a valuable procedure for the treatment of natural gas and destination of process by-products. The study of the obtained absorption curves makes possible to determine the mass transfer predominant stage in the involved processes, the mass transfer volumetric coefficients, and the equilibrium concentrations. It was also performed a kinetic study. The obtained results showed that the H2S removal kinetics is greater for NaOH. Considering that the study was performed at low concentrations of chemical reagents, it was possible to check the effect of secondary reactions in the other chemicals, especially in the case of KMnO4, which shows that your by-product, MnO2, acts in H2S absorption process. In addition, CuSO4 and FeCl3 also demonstrated to have good efficiency in H2S removal

Avaliação da coluna vertebral: relação entre gibosidade e curvas sagitais por método não-invasivo

Os objetivos do estudo foram avaliar o alinhamento, no plano sagital, da coluna de indivíduos com alterações na medida da gibosidade, comparando com um grupo sem alterações; testar a confiabilidade do instrumento utilizado e verificar se existem correlações entre as medidas da gibosidade e os valores das curvaturas vertebrais. Foram avaliados 40 jovens, divididos em grupo controle - ausência ou presença de gibosidades inferiores a 0,5 cm na curvatura torácica e 0,7 cm na lombar (n=20) e, grupo experimental - gibosidades superiores às descritas (n=20). A gibosidade e as curvaturas no plano sagital foram mensuradas com um instrumento adaptado a um nível d'água e o teste de Adams. As coletas foram realizadas em duas datas distintas, nos dois grupos. Após aplicação do teste Mann-Whitney não foi encontrada diferença entre as ocasiões de coletas e, emparelhando-se os grupos, foi encontrada diferença apenas na medida cervical. Na verificação de existência de relação entre as medidas coletadas, foi encontrada correlação linear (Spearmann) no grupo controle - curvatura torácica e gibosidade torácica; em ambos os grupos - curvaturas torácica e lombar; e no grupo experimental - gibosidade torácica e as curvaturas lombar e sacral e, curvatura sacral e curvaturas torácica e lombar. Pôde-se concluir que a medida da gibosidade tem relações com as curvaturas no plano sagital. Por ser um método confiável, simples e acessível, pode ser reproduzido sem altos custos financeiros e sem causar prejuízo à saúde do paciente.

Quantificação do linalol no óleo essencial da Aniba duckei Korstermans utilizando uma nova coluna capilar POLYH4-MD em Cromatografia Gasosa

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

Utilização de uma coluna de flotação para remoção de compostos orgânicos da água de produção

Innovative technologies using surfactant materials have applicability in several industrial fields, including petroleum and gas areas. This study seeks to investigate the use of a surfactant derived from coconut oil (SCO saponified coconut oil) in the recovery process of organic compounds that are present in oily effluents from petroleum industry. For this end, experiments were accomplished in a column of small dimension objectifying to verify the influence of the surfactant SCO in the efficiency of oil removal. This way, they were prepared emulsions with amount it fastens of oil (50, 100, 200 and 400 ppm), being determined the great concentrations of surfactant for each one of them. Some rehearsals were still accomplished with produced water of the industry of the petroleum to compare the result with the one of the emulsions. According to the experiments, it was verified that an increase of the surfactant concentration does not implicate in a greater oil removal. The separation process use gaseous bubbles formed when a gas stream pass a liquid column, when low surfactant concentrations are used, it occurs the coalescence of the dispersed oil droplets and their transport to the top of the column, forming a new continuous phase. Such surfactants lead to a gas-liquid interface saturation, depending on the used surfactant concentration, affecting the flotation process and influencing in the removal capacity of the oily dispersed phase. A porous plate filter, with pore size varying from 40 to 250 mm, was placed at the base of the column to allow a hydrodynamic stable operation. During the experimental procedures, the operating volume of phase liquid was held constant and the rate of air flow varied in each experiment. The resulting experimental of the study hydrodynamic demonstrated what the capturing of the oil was influenced by diameter of the bubbles and air flow. With the increase flow of 300 about to 900 cm3.min-1, occurred an increase in the removal of oil phase of 44% about to 66% and the removal kinetic of oil was defined as a reaction of 1° order.

Sistematização da assistência de enfermagem a paciente com luxação de coluna cervical: estudo de caso

Trata-se de um estudo de caso de paciente portador de luxação de coluna cervical. Sem comprometimento medular, no qual as autoras operacionalizaram o processo de enfermagem, segundo Modelo Conceitual de Horta, adaptando a Taxonomia I dos Diagnósticos de Enfermagem proposta pela North American Nursing Diagnosis Association (NANDA). Os resultados demonstraram que as intervenções propostas ao caso contribuíram na sua reabilitação, prevenindo complicações, bem como ajudando-o a retomar ao seu ambiente social para reassumir a sua autonomia.

Aspectos tomográficos da coluna cervical de equinos

Descreveu-se a anatomia da região cervical de equinos adultos, com base em imagens obtidas no exame de tomografia computadorizada helicoidal realizado em peças anatômicas de equinos adultos. A tomografia computadorizada foi o método de imagem diagnóstica de escolha e possibilita as reconstruções de imagens tridimensionais e em outros planos anatômicos, como sagital e coronal. Todas as imagens foram adquiridas e avaliadas em filtro e janela para tecido ósseo. Observaram-se diferenças anatômicas e as particularidades normais das vértebras, principalmente da região occipitoatlantoaxial, a qual apresenta maior incidência de alterações.

Características limnológicas da coluna d'água e dos efluentes de viveiros de criação de camarões-da-amazônia

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A proposta biomecânica para a avaliação de sobrecarga na coluna lombar: efeito de diferentes variáveis demográficas na fadiga muscular

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Método colorimétrico para determinação de dióxido de nitrogênio atmosférico com preconcentração em coluna de c-18

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

Desenvolvimento de um método analítico rápido e eficiente para a determinação de corticosteróides plasmáticos por injeção direta em coluna cromatográfica ISRP-C18 por CLAE

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribuição do macrozoobentos na coluna vertical dos sedimentos da região estuarina de Cananéia (SP), Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Injeção subaracnóidea inadvertida de corticoíde em tratamento de dor crônica da coluna lombar. Relato de caso

BACKGROUND AND OBJECTIVES: Before epídural steroids were used in chronic lumbar pain, subarachnoid injection of these agents was the treatment of choice. Although still preconized by some authors, this technique may lead to severe complications with neurological sequelae. This report aimed at describing a case of accidental subarachnoid injection of steroid associated to local anesthetics during epidural puncture to treat lumbar pain. CASE REPORT: Male patient, 46 years old, followed byneuro-surgery for presenting right sciatic pain for 9 month, refractory to clinical treatment due to L 4-L 5 disk protrusion confirmed by CT scan, without neurological deficit. Epidural puncture for pain treatment was performed in L 4-L 5 with 17G needle and 10 mL solution were injected containing 4 mL of 0.25% bupivacaine, 80 mg methylprednisolone and 4 mL of 0.9% saline. Although there has not been CSF reflux, 5 minutes after injection there were sensory block in T 4 and motor block in T 6, associated to blood pressure and heart rate decrease. CONCLUSIONS: Accidental subarachnoid injections with the association of steroids for pain relief may cause adverse effects. There are several risks, varying from mild transient symptoms to nervous injuries, including spinal cord injuries. Our patient had no sequelae from the accidental subarachnoid injection, probably because it has been a single injection.

Protocolo de exame físico para a coluna toracolombar de equinos

Thoracolumbar injuries represent a challenge to the veterinarian that seeks to eliminate the pain, reinstitute the athletic use of the horse and minimize economic losses. The percentage of lost training days due to orthopedic conditions in race horses is of 72.1% and within those conditions is back pain, whicht represents from 4.35% to 20% of the lameness cases. The present study searched to establish a protocol based on score points for the thoracolumbar physical exam, by which it is able to determine the possible affected areas and the seriousness of the injuries. Along with the physical exam, it was performed an ultrasonographic exam of the thoracolumbar region to characterize and classify the injuries found, as to accompany its evolution after treatment. It was observed a clear reduction in the physical exam score sum in all animals between the exam days being that the exam of most of the animals presented a zero score at 60 days after the treatment. Relating the evolution of the clinical exam with the ultrasonography image tests, there was a positive association between the reduction score in the severity scale and the evolution of the ultrasonographic image of the evaluated structures. Thus, it can be concluded that gradation of the physical exam showed to be efficient and allowed the monitoring of the clinical evolution, as the answer of the injuries to the suggested treatment. Besides that, the results showed that 60 days is the ideal time for the first reevaluation of the animal after the treatment.

Efeito de dietas e altura da coluna d’água na sobrevivência de larvas de Betta splendens e o aporte de nitrogênio e fósforo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise do princípio centrando do método pilates e de indicadores de resistência e estabilidade da coluna lombar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)