Desafios do pré-sal para a Comunidade Científica e Tecnológica Brasileira

This article deals with the diverse researches carried out in the field of oilproduction which led Brazil to the finding of hydrocarbon reserves under saltlayers; that is, in places considered to be non-favorable till then. In doing so, ithighlights the role played by the Petrobras Research and Development Center(Cenpes), and the participation of the University of São Paulo in that process.O artigo aborda as diversas pesquisas feitas no campo da produção do petróleoe que levaram o Brasil à descoberta de reservas de hidrocarbonetos abaixodas camadas salinas, ou seja, em locais até então considerados não propícios.Nesse sentido, destaca o Centro de Pesquisa e Desenvolvimento da Petrobras(Cenpes) e a participação da Universidade de São Paulo nesse processo

The determination of glial fibrillary acidic protein for the diagnosis and histogenetic study of central nervous system tumors: a study of 152 cases.

Glial fibrillary acidic protein (GFAP) was purified from human spinal cord and cerebral white matter. GFAP was localized by an immuno-peroxidase method in normal adult and fetal human brains, rat brains, and 152 central nervous system (CNS) tumors. GFAP was found in reactive and normal astrocytes, immature cells of fetal brain at the 18th to 21st gestational weeks, and normal rat astrocytes. This GFAP staining was quite specific for glial tumors, including astrocytomas, glioblastomas, astroblastomas, and ependymomas. GFAP-positive cells were also found in oligodendrogliomas and choroid plexus papillomas, and they were interpreted as being astroglial or ependymal differentiations. Stromal cells in cerebellar hemangioblastomas were negative. However, engulfed astrocytes were found at the periphery of such tumors and often adjacent to the proliferate blood vessels. In meningiomas, neurinomas, metastatic carcinomas, pituitary adenomas and other non-glial tumors, GFAP-positive cells were not identified.</p

Numerical simulation of oil leakage, water flooding and damaged stability of oil carrier based on moving particle semi-implicit (MPS) method

Oil leakage or water flooding in a damaged oil carrier are complex phenomena that involve fluid-solid interaction with complicated geometry and multiphase flow. In order to assess the damaged stability and environmental impact when the damage occurs, the present research models the non-linear hydrodynamic problems by using a numerical approach based on MPS (Moving particle Semi-Implicit) method. The comparison of numerical results with that obtained by quasi-static approach shows the limit of validity of the last one. Cconsidering the reduced dimension of the opening of the damage, the effects of the resolution of spatial discretization are also analysed

Flow conditioning modeling and application to particle method

This work comprises the development of a re-circulation boundary condition to simulate the flow around a cylinder using the Moving Particles Simulation (MPS). The recirculation boundary condition consists in the re-injection of the fluid particles that flows out the downstream boundary of the computational domain into the upstream boundary through the application of a periodic boundary condition, and a flow conditioner that comprises a region where the velocities of the fluid particles are gradually adjusted to a uniform flow by suppressing the velocity perturbations. The proposed recirculation boundary condition is applied to simulate the flow around a fixed cylinder and the vortex sheet formation process. The Strouhal Number x Reynolds Number diagram obtained using the MPS method show results close to those present in literature. For the laminar flow, the streamlines of MPS simulations show similarity with experimental results present in literature

Investigation of green water in FPSO by a particle-based numerical offshore tank

The green water is a highly non linear hydrodynamic phenomenon that occurs when the wave height exceeds the freeboard of the floating structures in harsh environments, and may compromise the operation and security of the on deck equipment. In the present study, in order to assess the effects of the green water phenomenon in FPSO and FLNG systems, the Moving Particle Semi-implicit (MPS) method, which is a fully lagrangian particle-method for incompressible flow, is adopted to model the complex fluid structure interaction problem. This article is focused on the recent developments of the MPS based simulation system of Numerical Offshore Tank (TPN-USP) and its application to the real scale offshore engineering problem. Results of large scale simulations using distributed memory architecture for models from 30 million to 100 million particles are presented

Electron microscopic features of a brain tumor induced in hamster by BK virus, a human papova virus.

In order to locate the target cells for malignant transformation by BK virus (a human papova virus) in hamster brain, electron microscopic observation of tumor originally induced in hamster brain by BK virus was performed. With light microscopy, the BK virus-induced tumor (Vn 17) bore a close resemblance to human malignant ependymoma. Under the electron microscope, numerous microvilli and few cilia were visible on the surface of the tumor cells. These tumor cells were joined to each other by desmosomes. Gap junctions were not observed. Multilayered cuboidal cells were observed around the lumen and blood vessels in the tumor. With regard to fine structure, three types of Vn 17 cells were recognized; ependymal like cells, tanycytes with prominent cell processes, and undifferentiated cells with few cytoplasmic organelles. There was no basal lamina between the ependymal cells and the connective tissue stroma. The Vn 17 cells showed some similarity to the ultrastructural features of the epemdymal cells of newborn rabbits, suggesting that the target cells for Vn 17 may be cells related to ependyma. Malignant transformation of the cells would be initiated in the early stages after BK virus inoculation into the brain of newborn hamsters.</p

Alteration of water-soluble S-100 protein content in microembolized rat brain.

The amount of S-100 protein in rat brain embolized with carbon microspheres decreased in parallel with the development of cerebral edema as judged by water content, recovering to the normal range by 24h after embolization. These results suggest the participation of S-100 protein in the permeability characterisitics of nervous system capillaries known as the blood-brain barrier.</p