Estudo da influência de sistemas microemulsionados na molhabilidade de arenitos e na recuperação avançada de petróleo

Sandstone-type reservoir rocks are commonly responsible for oil accumulation. The wettability is an important parameter for the physical properties of the container, since it interferes in characteristics such as relative permeability to the aqueous phase, residual oil distribution in the reservoir, operating characteristics with waterflood and recovery of crude oil. This study applied different types of microemulsion systems - MES - in sandstone reservoirs and evaluated their influences on wettability and residual oil recovery. For this purpose, four microemulsion were prepared by changing the nature of ionic surfactants (ionic and nonionic). Microemulsions could then be characterized by surface tension analysis, density, particle diameter and viscosity in the temperature range 30° C to 70° C. The studied oil was described as light and the sandstone rock was derived from the Botucatu formation. The study of the influence of microemulsion systems on sandstone wettability was performed by contact angle measurements using as parameters the rock treatment time with the MES and the time after the brine surface contact by checking the angle variation behavior. In the study results, the rock was initially wettable to oil and had its wettability changed to mixed wettability after treatment with MES, obtaining preference for water. Regarding rock-MES contact time, it was observed that the rock wettability changed more when the contact time between the surface and the microemulsion systems was longer. It was also noted only a significant reduction for the first 5 minutes of interaction between the treated surface and brine. The synthesized anionic surfactant, commercial cationic, commercial anionic and commercial nonionic microemulsion systems presented the best results, respectively. With regard to enhanced oil recovery performance, all systems showed a significant percentage of recovered oil, with the anionic systems presenting the best results. A percentage of 80% recovery was reached, confirming the wettability study results, which pointed the influence of this property on the interaction of fluids and reservoir rock, and the ability of microemulsion systems to perform enhanced oil recovery in sandstone reservoirs.

Avaliação clínica e da qualidade de vida utilizando dois protocolos para recuperação miofuncional em pacientes que se submeteram à cirurgia ortognática: resultados preliminares

The objective of this randomized, blind and prospective clinical trial was to compare the pain, the edema, the mandibular movements, the masticatory efficiency and life quality, in the first 60 days after surgery using 2 different clinical protocols for myofunctional recovery, in patients who underwent orthognathic surgery. A sample of 19 patients was used and divided into 2 groups. The control group (CG) consisted of 10 patients who had postoperative rehabilitation guided by a standard protocol, conducted by the Service of Surgery and Traumatology Oral and Maxillofacial. In other hand, the experimental group (EC) totaled 9 patients who received the speech therapy rehabilitation protocol specialized, by professionals in the area. The variables pain, edema and mandibular movements were analyzed during 48h, 96h, 7 days, 14 days, 30 and 60 days post-surgery. The masticatory efficiency and the quality of life were classified with 60 days after surgery . The data were submitted an analysis of variance, Student's t-test and Fisher's independence, at the level of 5% probability. It was identified that patients of GE have benefited in the first 14 days(p<0,001), as they have had reported less pain than those in the CG. Significant statistics differences between groups for pain parameters (after 14 days) (p=0,065), edema(p=0,063), mandibular movements(p=0,068), masticatory efficiency(p=0,630) and the impact on quality of life (p=0,813) were not observed on this study. The speech therapy protocol for myofunctional recovery (EG), although it has not obtained statistical results superiors than the CG in the general context, presents itself as a viable alternative to conventional therapy assumed by many maxillofacial surgeons, allowing the surgeon to optimize time with patients in the period postoperatively.

Politica de indexação: visando a qualidade para a recuperação da informação

NASCIMENTO, Bruna Laís C. do; FELIPE, Carla Beatriz Marques; BEZERRA, Midinai Gomes.Política de indexação: visando a qualidade para a recuperação da informação. In: SEMINÁRIO DE PESQUISA DO CCSA, 16., 2010, Natal. Anais eletrônicos... Natal: UFRN, 2010. Disponível em:.

Caracterização ecológica dos peixes recifais do Atol das Rocas

The present work was carried out at the Atol das Rocas (3º 51 S; 33º 49 W), the only atoll of the South Atlantic and the first Brazilian marine protected area. It was guided by the following hypothesis: the composition of the fish communities varies in agreement with the position of the pools; in other words, with or without permanent ocean connection. To test the validity of this hypothesis, the fish abundance was estimated in the connected pools (Barretinha/Barreta Falsa) and unconnected ones (Cemiteriozinho/Âncoras), carrying an ecological characterization of the fishes that inhabit these pools. Additionally, the structural complexity of the sampled places was also evaluated intending to verify the variations of the abundance and diversity of fishes in function to this factor. By the fact of this research was being carried out through the limits of a conservation unit, the samples was realized using visual census techniques. The results generated through uni and multivariate analytic techniques allowed the evidence that decisive factor in the density, richness and diversity variations of fishes are linked to the substratum type (Hard / Soft bottom) and not by the fact that the pool are or are not connected permanently to the ocean. In relation to the structural complexity; 58% of the variations in the diversity of fishes were attributed to changes in the structural complexity, while 12% of the variations in the abundance were attributed to the structural complexity