Estudo da absorção das espécies pesadas do gás natural em octanol: efeitos da temperatura e vazão

In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 °C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.

Estudo da absorção das espécies pesadas do gás natural em octanol: efeitos da temperatura e vazão

In the oil industry, natural gas is a vital component of the world energy supply and an important source of hydrocarbons. It is one of the cleanest, safest and most relevant of all energy sources, and helps to meet the world's growing demand for clean energy in the future. With the growing share of natural gas in the Brazil energy matrix, the main purpose of its use has been the supply of electricity by thermal power generation. In the current production process, as in a Natural Gas Processing Unit (NGPU), natural gas undergoes various separation units aimed at producing liquefied natural gas and fuel gas. The latter should be specified to meet the thermal machines specifications. In the case of remote wells, the process of absorption of heavy components aims the match of fuel gas application and thereby is an alternative to increase the energy matrix. Currently, due to the high demand for this raw gas, research and development techniques aimed at adjusting natural gas are studied. Conventional methods employed today, such as physical absorption, show good results. The objective of this dissertation is to evaluate the removal of heavy components of natural gas by absorption. In this research it was used as the absorbent octyl alcohol (1-octanol). The influence of temperature (5 and 40 °C) and flowrate (25 and 50 ml/min) on the absorption process was studied. Absorption capacity expressed by the amount absorbed and kinetic parameters, expressed by the mass transfer coefficient, were evaluated. As expected from the literature, it was observed that the absorption of heavy hydrocarbon fraction is favored by lowering the temperature. Moreover, both temperature and flowrate favors mass transfer (kinetic effect). The absorption kinetics for removal of heavy components was monitored by chromatographic analysis and the experimental results demonstrated a high percentage of recovery of heavy components. Furthermore, it was observed that the use of octyl alcohol as absorbent was feasible for the requested separation process.

Métodos de avaliação nutricional para a suplementação oral com zinco em crianças pré-púberes não deficientes em zinco

Background: Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cellmediated immune dysfunction, and cognitive impairment. Objective: This study evaluated nutritional assessment methods for zinc supplementation in prepubertal nonzinc- deficient children. Design: We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n = 31) and an experimental group (10 mg Zn/day, n = 31) for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children. Results: Our study showed (1) an increased body mass index for age and an increased phase angle in the experimental group; (2) a positive correlation between nutritional assessment parameters in both groups; (3) increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4) increased consumption of all nutrients, including zinc, in the experimental group; and (5) an increased serum zinc concentration in both groups (p < 0.0001). Conclusions: Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

Métodos de avaliação nutricional para a suplementação oral com zinco em crianças pré-púberes não deficientes em zinco

Background: Zinc is an essential nutrient that is required for numerous metabolic functions, and zinc deficiency results in growth retardation, cellmediated immune dysfunction, and cognitive impairment. Objective: This study evaluated nutritional assessment methods for zinc supplementation in prepubertal nonzinc- deficient children. Design: We performed a randomised, controlled, triple-blind study. The children were divided into a control group (10% sorbitol, n = 31) and an experimental group (10 mg Zn/day, n = 31) for 3 months. Anthropometric and dietary assessments as well as bioelectrical measurements were performed in all children. Results: Our study showed (1) an increased body mass index for age and an increased phase angle in the experimental group; (2) a positive correlation between nutritional assessment parameters in both groups; (3) increased soft tissue, and mainly fat-free mass, in the body composition of the experimental group, as determined using bioelectrical impedance vector analysis; (4) increased consumption of all nutrients, including zinc, in the experimental group; and (5) an increased serum zinc concentration in both groups (p < 0.0001). Conclusions: Given that a reference for body composition analysis does not exist for intervention studies, longitudinal studies are needed to investigate vector migration during zinc supplementation. These results reinforce the importance of employing multiple techniques to assess the nutritional status of populations.

Métodos de extração de fósforo e micronutrientes em latossolos com uso de energia ultrassônica

Assessing the soil nutrient availability to plants under lab conditions is one of the main challenges to Soil Fertility and Chemistry, due to the complex behavior and the interaction of the soil properties. Many extractant solutions associated with mechanical forms of agitation have been proposed, showing different correlations with plant growth and nutrients absorption. Using ultrasonic energy is a agitation procedure of the soil:extractant solution suspension (based on the cavitation phenomenon). It allows the establishment of relations between the amount of extracted nutrient and the ultrasonic energy level. Thus, this work aims: to evaluate the effect of cavitation intensity on the extraction of P, Zn, Cu, Mn and Fe in soil samples from five Latosols under different uses around Uberlândia and Uberaba, Minas Gerais State; to obtain extracting curves as function of ultrasonic energy levels; and to obtain an index from extracting curves to expresses the nutrient retention by the soil solid phase. A soil-solution suspension (ratio 1:10) was sonicated using a probe ultrasound equipment under different combinations of power and time: i) 30 W for 35, 70, 140 and 280 s; ii) 50 W for 21, 42, 84 and 168 s; and iii) 70 W for 15, 30, 60 and 120 s. The extractant solutions used were Mehlich-1 (for all elements), Olsen and distilled water for P. After each sonication, P concentration was quantified by molybdenum blue colorimetric method and Zn, Cu, Mn and Fe by flame atomic absorption spectrophotometry. The cavitation intensity did not affect the P extraction, only the total energy applied. The P extraction was influenced by extractant solution, decreasing as follows: Mehlich-1>Olsen>water. In cultivated Latosols, the P extraction increased linearly with ultrasonic energy, and the slope of the 1:1 linear regression reflects the P retention in the soil. The Zn and Fe extractions were influenced only by total energy applied. Mn and Cu extractions were influenced by both cavitation intensity and total ultrasonic energy. Soils containing similar amounts of P, Cu, Zn, Mn, and Fe may have a different extraction rate. Likewise, soils containing different amounts of those elements may have the same extraction rate.

Experimentos de nutrientes y productividad con agua de mar y de la desembocadura del río Rimác

Al estudiar los problemas de la contaminación marina en micro escala se ha realizado últimamente análisis de nutrientes y clorofila "a" en el área del Callao. La relación de datos de los bioensayos realizados en el muestreo 8408 y 8411 de Callao son dados en Guillen et al, 1984. En dichos análisis se ha encontrado que la concentración de tales parámetros es diferente en aguas muy costeras que en aguas más alejadas de la costa, por lo que se ha realizado este trabajo con el propósito de conocer estas variaciones y comparar con los resultados de la misma área de 1985.

Produção de biomassa e exportação de nutrientes de Eucalyptus grandis e E. urophylla

Scientific research in forest production technology area search techniques that increase production per unit area, with high economic viability and reducing environmental impacts. When dealing with forest plantations, studies are needed in the production of biomass and its nutrient content, and these are data parameters for planning the environmental implications of different intensities of forest harvesting. Given the above, this study aimed to elucidate the production and export of biomass and nutrients for two species of the genus Eucalyptus (E. grandis and E. urophylla) grown in the southwestern region of Parana. For this, it was evaluated: the stock of biomass and nutrients in eucalyptus (wood, bark, branches and leaves) at 60 months of age; the export rate of nutrients; the calorific value and economic viability. The biomass and the largest eucalyptus nutrient stocks are predominantly allocated to the stem (wood + bark). The components of biomass showed different chemical compositions, generally being higher in the leaves and bark and lower in wood and branches components. As for the calorific value, the leaves had its calorific value statistically superior than the other fractions, followed by branches, wood and bark. The organic carbon content (C.O.) is directly connected to the calorific value, and the calorific value increases as its content increase. The wood had the highest nutrient use efficiency values, something highly desirable and of great interest to forestry. The leaves showed smaller nutrient utilization efficiency values, with the exception of Ca and Mg that were smaller in the bark, indicating the importance of maintaining these components in the soil after harvest. The wood fraction presents the biomass lower cost when considering the replacement of nutrients exported by its biomass. On the other hand, the leaf fraction showed NPK higher cost of replacement.

Crecimiento, acumulación de biomasa seca y nutrientes en los frutos de café (Coffea arabica L.) variedad Pacas, Masatepe, Nicaragua

De abril a diciembre de 2012, en un ensayo ya establecido se realizó un estudio en el cultivo de café variedad pacas, con el objetivo de determinar las curvas de crecimiento, acumulación de biomasa seca y acumulación de nutrientes (N, P, K, Ca y Mg) en los frutos de café uva. El ensayo fue establecido en el año 2000 en el Jardín Botánico hoy conocido como Centro Nacional de Educación y Cooperativis mo (CENECCOP), Masatepe, Nicaragua. Se seleccionaron cuatro parcelas grandes con combinación de árboles de sombra maderables y de servicio y una parcela a pleno sol. Los tratamientos en estudio fueron a) Inga laurina y Simaruba glauca, b) Samanea saman y Tabebuia rosea, c) Samanea saman e Inga laurina, d) Tabebuia rosea y Simaruba glauca y e) una parcela a pleno sol. Las parcelas fueron distribuidas en un diseño de bloques completos al Azar (BCA). Las variables evaluadas en los frutos de café fueron diámetro polar, diámetro ecuatorial y peso seco. Los frutos se secaron en el horno a 70 °C y posteriormente se utilizó un molino Foss Tecator Cyclotec para obtener una muestra fina. De la muestra molida de los frutos, en el laboratorio de suelo y agua de la UNA se determinaron las concentraciones de N, P, K, Ca y Mg. Los datos fueron colectados cada 30 días. Para el análisis estadístico se utilizó SAS 9.1. Las curvas de crecimiento del fruto y la acumulación de peso seco se ajustaron a regresiones no lineales simples y dobles exponenciales. Se realizó una correlación entre el diámetro polar y diámetro ecuatorial de los frutos dando un coeficiente de determinación r de 98% (Pr>F= 0.0001). Para el ajuste de la curva de aumento de peso seco se utilizó el modelo Probit normal. El mayor crecimiento de los frutos se dio durante los primeros 90 días y la mayor acumulación de nutrientes se dio entre los 90 y 210 días. La combinación de árboles leguminosos presentó el diámetro polar y ecuatorial más alto. También la acumulación de biomasa seca fue mayor en el tratamiento con sombra de leguminosas.

Valoração do efluente da indústria processadora de pescado por incorporação de nutrientes em aphanothece microscopica nägeli

Nesta tese procurou-se demonstrar a valoração do efluente do processamento de pescado por incorporação dos nutrientes em Aphanothece microscopica Nägeli a diferentes temperaturas. Para tanto o trabalho é composto de cinco artigos que objetivaram avaliar sob o ponto de vista do tratamento do efluente pela cianobactéria Aphanothece e a separação e avaliação da biomassa gerada. O primeiro artigo intitula-se “Influência da temperatura na remoção de nutrientes do efluente da indústria de pescado por Aphanothece microscopica Nägeli”, e teve por objetivo avaliar a influência da temperatura (10, 20 e 30ºC) em um sistema de tratamento pela cianobactéria Aphanothece na remoção de matéria orgânica, nitrogênio e fósforo do efluente oriundo do processamento de pescado. A análise dos resultados mostrou que a temperatura influenciou significativamente na remoção de DQO, NTK, N-NH4 + e P-PO4 -3 . Para os experimentos a 20 e 30ºC todos os limites estabelecidos para os parâmetros avaliados foram atingidos. O segundo artigo intitulado “Efeito de coagulantes no efluente da indústria da pesca visando à separação de biomassa quando tratado por cianobactéria” avaliou o efeito da concentração e pH de dois tipos de coagulantes, cloreto férrico (FeCl3) e sulfato de alumínio (Al2(SO4)3), na separação da biomassa da cianobactéria Aphanothece microscopica Nägeli cultivada em efluente da indústria da pesca, assim como a remoção de matéria orgânica e nutrientes do efluente. Os resultados indicaram que o coagulante FeCl3 foi mais eficaz na remoção de todos os parâmetros testados. No que concerne à separação da biomassa, com um número de seis lavagens foi removido cerca de 97,6% da concentração de FeCl3 adicionado inicialmente. O terceiro artigo com o título “Caracterização da biomassa de Aphanothece microscopica Nägeli gerada no efluente da indústria da pesca em diferentes temperaturas de cultivo” avaliou a composição química da biomassa da cianobactéria Aphanothece microscopica Nägeli quando desenvolvida em meio de cultivo padrão BG11 e no efluente do processamento de pescado. O quarto artigo teve como título “Influência do meio de cultivo e temperatura em compostos nitrogenados na cianobactéria Aphanothece microscopica Nägeli” objetivou avaliar o teor de compostos nitrogenados presentes na biomassa da cianobactéria Aphanothece microscopica Nägeli quando cultivada em meio padrão e no efluente da indústria da pesca nas diferentes fases de crescimento. Para o estudo da composição química e nitrogenados no efluente foram realizados experimentos nas temperaturas de 10, 20 e 30ºC. As concentrações de proteína, cinzas e pigmentos aumentaram com o aumento da temperatura. Por outro lado, foi observada uma redução do teor de lipídios e carboidratos com o aumento da temperatura. O íon amônio juntamente com os ácidos nucléicos representa uma importante fração do nitrogênio não protéico presente na biomassa da cianobactéria Aphanothece. Ficou demonstrada a influência do meio de cultivo na concentração de nitrogênio, bem como a determinação de proteína pelo método de Kjeldahl superestima a concentração protéica em cianobactérias. O quinto artigo intitulado “Produção de proteína unicelular a partir do efluente do processamento do pescado: modelagem preditiva e simulação” avaliou a produção de proteína unicelular através do cultivo da cianobactéria Aphanothece microscopica Nägeli no efluente da indústria da pesca. Os dados cinéticos de crescimento celular foram ajustados a quatro modelos matemáticos (Logístico, Gompertz, Gompertz Modificado e Baranyi). Os resultados demonstraram que o modelo Logístico foi considerado o mais adequado para descrever a formação de biomassa. A análise preditiva mostrou a possibilidade da obtenção de 1,66, 18,96 e 57,36 kg.m-3.d-1 de biomassa por volume do reator em 1000 h de processo contínuo, para as temperaturas de 10, 20 e 30ºC, respectivamente.

Altura do pasto e adubação nitrogenada sobre a produção de forragem e eficiência no uso de nutrientes em sistema de integração lavoura-pecuária

The proper use of management strategies, such as grazing intensity and nitrogen fertilization are primordial to the success of integrated crop-livestock system. Several studies have demonstrated the influence of grazing intensity and nitrogen fertilization on dynamics of forage production and nutrient cycling. However, most this researches studying these strategies in isolation and little is known about the interaction of these factors in the management of an integrated crop-livestock system. In this context, the aim of this study is to determine the best management strategy involving sward height and nitrogen fertilization, permitting greater forage production and improved efficiency in the use of nitrogen soil by a black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture in integrated crop-livestock system. The experiment was realized in Abelardo Luz – SC, in an area of 14 ha, where has been conducted an experiment in long term with integrated crop-livestock system under no-tillage since 2012. The experimental design is a randomized block design with three replications in a factorial design (2x2), the first factor was the grazing intensity (high and low), characterized by two sward height management (10 and 25 cm), and the second included the time factor application of N in the system: N applied on pasture (N-pasture) and N applied on the culture of grain (N-grain), at dose of 200 kg N ha stocking and variable stocking rate. The previous crop to pasture was corn. The nitrogen fertilization of pasture increased tiller density, forage density, participation of ryegrass ‘Barjumbo’ and percentage of ryegrass leaves in forage mass. Forage mass was less at low sward height on average, however the percentage of ryegrass ‘Barjumbo’ and rye leaves was greater and dead material was lower in this treatment. With nitrogen fertilization of pasture it was possible to double the amount of forage accumulated in periods with further development of ryegrass, furthermore, the total production of DM was increased in 38.4% and the shoot N concentration in 28.6%. When the nitrogen fertilization is applied in pasture, it is possible to keep black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture with an average sward height of 11 cm. The residual effect of N applied at corn was not sufficient to meet the nutritional needs of pasture and the forage production was affected by periods with N deficiency, while a single application of 200 kg N ha was sufficient to meet the N requirements throughout the forage accumulation period. The black oat ‘BRS 139’ plus ryegrass ‘Barjumbo’ pasture is efficient in use and recovery of the nitrogen applied in both treatments of sward height.

Efeitos da tilápia do Nilo (Oreochromis niloticus) e do enriquecimento por nutrientes sobre a comunidade planctônica em um lago artificial no semi-árido brasileiro

The major aim of this study was to test the hypothesis that the introduction of the Nile tilapia (Oreochromis niloticus) and the enrichment with nutrients (N and P) interact synergistically to change the structure of plankton communities, increase phytoplankton biomass and decrease water transparency of a semi-arid tropical reservoir. One field experiment was performed during five weeks in twenty enclosures (8m3) to where four treatments were randomly allocated: with tilapia addition (T), with nutrients addition (NP), with tilapia and nutrients addition (T+NP) and a control treatment with no tilapia or nutrients addition (C). A two-way repeated measures ANOVA was done to test for time (t), tilapia (T) and nutrient (NP) effects and their interaction on water transparency, total phosphorus, total nitrogen, phytoplankton and zooplankton. The results show that there was no effect of nutrient addition on these variables but significant fish effects on the biomass of total zooplankton, nauplii, rotifers, cladocerans and calanoid copepods, on the biovolume of Bacillariophyta, Zygnemaphyceae and large algae (GALD ≥ 50 μm) and on Secchi depth. In addition, we found significant interaction effects between tilapia and nutrients on Secchi depth and rotifers. Overall, tilapia decreased the biomass of most zooplankton taxa and large algae (diatoms) and decreased the water transparency while nutrient enrichment increased the biomass of zooplankton (rotifers) but only in the absence of tilapia. In conclusion, the influence of fish on the reservoir plankton community and water transparency was greater than that of nutrient loading. This finding suggests that biomanipulation should be a greater priority in the restoration of eutrophic reservoirs in tropical semi-arid regions

Efeito dos nutrientes (nitrogênio e fósforo) sobre o desenvolvimento da Gracilaria birdiae: crescimento e possível uso como biofiltro

Marine shrimp farming has grown exponentially during the last years in Brazil. In spite of the promising economical situation, this activity is facing an increasing criticism due to its environmental impact. Thus, the necessity of alternatives to mitigate environmental degradation caused by this activity. An alternative that is being studied is the policulture that is the integrated culture of two or more organisms, normally one of them a filtering organism. Among filtering organisms, macroalgae are very practicable because they are efficient in the removal of the exceeding nutrients of the water and do not leave residues in the water. Besides, the integrated culture with macroalgae allows the economical exploration of the seaweed (for the manufacture of jelly and jam, for the dairy industry, pharmaceuticals, etc.) along with possibility of a sustainable aquaculture. In the present experiment, the development of the seaweed Gracilaria birdiae, the influence and tolerance of this species to the environmental parameters, and its absorption efficiency in relation with the three kinds of macronutrients (NH4+, NO3- and PO4-3) found in the effluents of marine shrimp farming was studied. The experiment was divided in two parts: a laboratorial part and one part carried under natural conditions. The water used in the laboratory trial was collected in the shrimp ponds of Tecnarão farm and distributed in aquaria containing 20 g of G. birdiae. In the field trial, 0.5 kg of G. birdiae was inserted in PVC cages cultivated in the farm. The results of the study showed a modest growth of G. birdiae, probably due to its low tolerance to highly eutrophicated environments. However, the removal of nutrients was very expressive. Ammonia was reduced in approximately 34 %. Ortho-phosphate showed a reduction of 93.5 %. The capacity of biofiltration of the NO3- by the macro algae was of 100 %, showing that G. birdiae is a seaweed-filtered with a high level of removal for this nutrient under laboratorial conditions. In spite of the low growth of the macro algae in the experiment, the results in relation to the removal of nutrients of the water was encouraging, suggesting that this species can be an efficient biofilter and thus, a strong candidate to be used in a sustainable aquaculture

Fritura da batata: influência do corte na absorção de gordura

As famílias portuguesas têm vindo a mudar o seu estilo de vida e tem-se assistido cada vez mais a uma diminuição do tempo e disponibilidade para a confeção das suas refeições diárias. Tal facto aumenta a procura e o consumo de alimentos de fácil confeção comercializados nas grandes superfícies comerciais, como é o caso das batatas pré-fritas congeladas. O objetivo deste trabalho foi determinar o teor de gordura total e o perfil de ácidos gordos de batatas pré-fritas, ultracongeladas, com diferentes tipos de corte. Em 2015, foram adquiridos em superfícies comerciais da região de Lisboa, 6 tipos de batatas pré-fritas ultracongeladas com diferentes cortes (palitos, palitos finos, cubos, rodelas, “steakhouse” e “noisette”). As amostras foram posteriormente sujeitas a fritura doméstica, com o mesmo tipo de óleo de fritura. O teor total de gordura das amostras (pré-fritas e fritas) foi determinado pelo método de hidrólise ácida e extração em Soxhlet com éter de petróleo, e o perfil de ácidos gordos foi determinado por cromatografia gasosa com deteção por ionização de chama. O teor total de gordura das amostras variou entre 3,01 e 14,9 g/100 g de parte edível para as batatas pré-fritas (cubos) e as batatas fritas (palitos finos), respetivamente. Durante a fritura, as batatas cortadas em palitos finos foram as que absorveram mais gordura (10,5 g/100 g), enquanto as batatas “noisette” foram as que menos absorveram (3,12 g/100 g). No que diz respeito ao perfil de ácidos gordos, 66,7% das amostras apresentaram maioritariamente ácidos gordos polinsaturados (AGPI), com teores que variaram entre 0,30 e 8,71 g/100 g de parte edível, para as batatas pré-fritas (cubos) e as batatas fritas (palitos finos), respetivamente. O teor de ácidos gordos saturados variou entre 0,83 e 2,16 g/100 g para as batatas “steakhouse” e palitos finos, ambas pré-fritas. Com este trabalho foi possível verificar que o tipo de corte da batata influencia diretamente a absorção de gordura aquando da sua fritura. Foi também possível concluir que as amostras analisadas apresentaram teores elevados de AGPI, sendo este perfil de ácidos gordos fortemente influenciado pelo óleo ou gordura utilizada na fritura, dado que a batata no seu estado natural apresenta um teor de gordura muito reduzido.

Balanço de nutrientes em explorações agrícolas da Ilha Terceira

Dissertação de Mestrado, Engenharia Agronómica, 20 de Julho de 2016, Universidade dos Açores.