Hydrogels Applied for Conformance-Improvement Treatment of Oil Reservoirs

This chapter aims at presenting a review of gelling polymer systems that are commercially available or under academic development with potential to control the anisotropic permeability profile of heterogeneous oil reservoirs. In these reservoirs, the oil recovery and sweep efficiency tend to be low, even after applying secondary and enhanced oil recovery methods, because the injected fluid flows preferably through the matrix’s most permeable regions leaving behind part of the displaceable oil retained at the nonswept volume. For that, cross-linked polymers can be used to plug the high-permeability main paths by means of: (i) the formation of an in situ hydrogel or (ii) the adsorption or swelling of pre–cross-linked hydrogel within the reservoir pores, thus causing the diversion of the subsequently injected fluid to low-permeability zones and/or preventing the channeling and early breakthrough of the injected fluid (water or gas) in production wells. The selection of the most suitable hydrogel for the reservoir conformance-improvement treatment should take into account the nature of the conformance problem, the reservoir’s lithology, mineralogy, temperature, pH value, salinity, and hardness of the formation water, as well as the gelling system toxicity and cost

CEREBROSPINAL FLUID DRAINAGE DEVICES: EXPERIMENTAL CARACTERIZATION

Hydrocephalus is a pathophysiology due to the excess of cerebrospinal fluid in the brain ventricles and it can be caused by congenital defects, brain abnormalities, tumors, inflammations, infections, intracranial hemorrhage and others. Hydrocephalus can be followed by significant rise of intraventricular pressure due to the excess of production of cerebrospinalfluid over the absorption, resulting in a weakening of intellectual functions, serious neurological damage (decreased movement, sensation and functions), critical physical disabilities and even death. A procedure for treatment involves the placement of a ventricular catheter into the cerebral ventricles to divert/drain the cerebrospinal fluid flow to a bag outside of the patient body – provisory treatment known as external ventricular drainage (EVD). Another option is the permanent treatment, internal ventricular drainage (IVD), promoting the cerebrospinal fluid drainage to other body cavity, being more commonly the abdominal cavity. In both cases, EVD and IVD, it is necessary to use of some type of neurological valve in order to control the flow of cerebrospinal fluid. In the present work is proposed an experimental procedure to test the hydrodynamic behavior of a complete drainage system, or parts of them, in order to verify its performance when subjected to pressure gradients found in the human body. Results show that the method is well adapted to quantify the pressure drop in neurological systems

Diagnóstico do meio físico da bacia hidrográfica do Rio do Imbé - RJ: aplicação de metodologia integrada como subsídio ao manejo de microbacias.

O Diagnóstico do Meio Físico da Bacia do Rio do Imbé (BHRI) integra os estudos que subsidiam o projeto Manejo Sustentável de Recursos Naturais em Microbacias do Norte-Noroeste Fluminense - SMH-SEAAPI/GEF (Global Enviroment Facility), cujo principal objetivo é apoiar produtores rurais de base familiar na autogestão dos recursos naturais, visando o desenvolvimento rural baseado em um modelo de agricultura socioambientalmente sustentável. A metodologia adotada partiu da integração da base cartográfica e dos dados digitais de mapeamentos temáticos do meio físico (clima, recursos hídricos, geologia, geomorfologia, solos e uso e ocupação das terras). Adotou-se no presente estudo a escala 1:250.000, compatível com a maioria dos dados secundários, que foram transformados para uma mesma projeção cartográfica e inseridos em uma base de dados digital. Inicialmente, foi realizada a síntese dos dados de solos e geomorfologia para a identificação e delimitação de unidades morfopedológicas. Em seguida, essas unidades foram agrupadas em seis zonas agroecológicas, considerando as potencialidades e fragilidades dos recursos naturais, os padrões de uso e o estado de degradação das terras. As zonas foram descritas e caracterizadas com base no conjunto de dados temáticos disponível e complementados com as informações levantadas em campo. O trabalho de campo foi orientado para verificação da diversidade dos aspectos físicos, das atividades antrópicas e dos problemas de degradação e conflitos relacionados ao uso dos recursos naturais. Foram considerados ainda o histórico socioeconômico e ambiental da região e a percepção dos atores locais com relação aos aspectos mencionados. Os resultados evidenciaram que a BHRI, face à singular interação dos aspectos fisiográficos e antrópicos, possui uma diversidade ambiental contrastante, apresentando diferentes potencialidades de uso e níveis de fragilidade. Contudo, o diagnóstico do meio físico, obtido segundo a metodologia apresentada, poderá constituir-se em um instrumento importante para subsidiar a tomada de decisões no que se refere às estratégias de planejamento, manejo adequado, monitoramento e avaliação dos recursos naturais, a serem adotados pelo projeto

The role of BAP in somatic embriogenesis induction from seed explants of Arachis species from Sections Erectoides and Procumbentes.

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Diagnóstico do meio físico das bacias hidrográficas do entorno da Mata do Carvão (BHMC), Noroeste do Estado do Rio de Janeiro.

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Assessment of genetic stability among in vitro plants of Arachis retusa using RAPD and AFLP markers for germplasm preservation.

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Diagnóstico do meio físico da bacia hidrográfica do Rio Muriaé.

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Diagnóstico do meio físico da bacia hidrográfica do Rio Doce/Canal Quitingute (BHRD)- RJ.

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Identification and quantification of microplastics in wastewater using focal plane array-based reflectance micro-FT-IR imaging

Microplastics (<5 mm) have been documented in environmental samples on a global scale. While these pollutants may enter aquatic environments via wastewater treatment facilities, the abundance of microplastics in these matrices has not been investigated. Although efficient methods for the analysis of microplastics in sediment samples and marine organisms have been published, no methods have been developed for detecting these pollutants within organic-rich wastewater samples. In addition, there is no standardized method for analyzing microplastics isolated from environmental samples. In many cases, part of the identification protocol relies on visual selection before analysis, which is open to bias. In order to address this, a new method for the analysis of microplastics in wastewater was developed. A pretreatment step using 30% hydrogen peroxide (H2O2) was employed to remove biogenic material, and focal plane array (FPA)-based reflectance micro-Fourier-transform (FT-IR) imaging was shown to successfully image and identify different microplastic types (polyethylene, polypropylene, nylon-6, polyvinyl chloride, polystyrene). Microplastic-spiked wastewater samples were used to validate the methodology, resulting in a robust protocol which was nonselective and reproducible (the overall success identification rate was 98.33%). The use of FPA-based micro-FT-IR spectroscopy also provides a considerable reduction in analysis time compared with previous methods, since samples that could take several days to be mapped using a single-element detector can now be imaged in less than 9 h (circular filter with a diameter of 47 mm). This method for identifying and quantifying microplastics in wastewater is likely to provide an essential tool for further research into the pathways by which microplastics enter the environment.This work is funded by a NERC (Natural Environment Research Council) CASE studentship (NE/K007521/1) with contribution from industrial partner Fera Science Ltd., United Kingdom. The authors would like to thank Peter Vale, from Severn Trent Water Ltd, for providing access to and additionally Ashley Howkins (Brunel University London) for providing travel and assistance with the sampling of the Severn Trent wastewater treatment plant in Derbyshire, UK. We are grateful to Emma Bradley and Chris Sinclair for providing helpful suggestions for our research