CHARACTERIZATION OF HETEROGENEITIES AT THE RESERVOIR SCALE: SPATIAL DISTRIBUTION AND INFLUENCE ON FLUID FLOW

ABSTRACTIn the Czochralski growth of single crystals from large melts, fluid flow phenomena have a major effect on interface shape, growth striations, defect density and the length of crystals which can be grown from a melt of given volume and thermal geometry. Because of the technical difficulties encountered in making direct measurements in molten oxides, simulation experiments have been extensively utilized to gain insight into melt behavior.Both temperature profile and flow geometry results from simulation experiments are discussed. This data is supported by direct melt observations and results from the characterization of grown crystals. When reviewed together, this information offers new insights into the complex behavior of Czochralski growth processes, including the role of thermal gradients, crystal rotation, and surface tension driven (Marangoni) convection.

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Digital autoradiography on C-14-labelled PMMA impregnated rock samples using the BeaverTM

MRS Advances ◽

10.1557/adv.2018.226 ◽

2018 ◽

Vol 3 (21) ◽

pp. 1161-1166 ◽

Cited By ~ 3

Author(s):

Mikko Voutilainen ◽

Juuso Sammaljärvi ◽

Eveliina Muuri ◽

Jérôme Donnard ◽

Samuel Duval ◽

...

Keyword(s):

Spatial Distribution ◽

Spent Nuclear Fuel ◽

Rock Sample ◽

Crystalline Rock ◽

Imaging Plate ◽

Heterogeneous Distribution ◽

Heterogeneous Structures ◽

In Situ Diffusion

In Finland and Sweden the KBS-3 concept has been chosen for the disposal of spent nuclear fuel in crystalline rock. Recent experiments have shown that heterogeneity of rock may play a major role in the transport of radionuclides. Autoradiographic methods have been proven to be able to assist the characterization of heterogeneous structures. In this study we tested a novel filmless autoradiographic device called BeaverTM which applies a micro patterned gaseous detector in order to quantitatively map beta emissions from C-14 atoms. The studied samples were impregnated with C-14-labelled methylmethacrylate (C-14-MMA) and polymerized to C-14-PMMA with thermal initiator. The BeaverTM was then used to determine the spatial distribution of the C-14-PMMA by measuring the C-14 emissions. The porosity is determined from the amount of C-14-PMMA in the rock sample and results were compared to ones from phosphor imaging plate autoradiography. The resulting images show a heterogeneous distribution of porosity which arises from the different minerals. The samples were chosen from three sites that have been used recently for in situ diffusion experiments: Olkiluoto (Finland), Äspö (Sweden) and Grimsel (Switzerland).

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CONHECENDO A PESCA ARTESANAL EM TRAMANDAÍ E IMBÉ – RS: DISTRIBUIÇÃO ESPACIAL E DESAFIOS

Ciência e Natura ◽

10.5902/2179460x24320 ◽

2017 ◽

Vol 39 (2) ◽

pp. 341

Author(s):

Abraão Martins Terceiro

Keyword(s):

Spatial Distribution ◽

Rio Grande ◽

Economic Importance ◽

The State ◽

Artisanal Fisheries ◽

Rio Grande Do Sul ◽

Popular Knowledge

The work deals with the theme artisanal fisheries and has as main objective, the characterization of the activity in the municipalities of Tramandaí and Imbé, located in the State of Rio Grande do Sul, the spatial distribution and the challenges to occur fisheries in this region. The research is justified by the large number of fishermen in the study area and the economic importance of the activity, mapping through popular knowledge areas of greatest value for fishing, the main existing species and the main features and instruments used in fish capture.

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