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In spent fuel nuclear reprocessing plant, nitric acid is the main medium used in PUREX method. The passive film compositions and corrosion resistance of 11 % Cr ferritic/martensitic and 9-15 % Cr oxide dispersion strengthened steels in different nitric acid concentrations were studied. The open circuit potential is shifted toward more noble potential as the concentrations increased from 1 M HNO to 9 M HNO in all the investigated alloy steels. The results of the potentiodynamic polarization plots also exhibited a shift in corrosion potential as the concentrations increased from 1 M to 9 M HNO This shift is undesirable because of risk of overshooting the potential beyond passive region and may result into transpassive corrosion. The X-ray photoelectron spectroscopy results of the passive film analysis are composed mostly of FeO, CrO, and YO, and the depth profile of Fe and Cr concentrations vary depending upon the nitric acid concentration. The surface morphology after the corrosion test does not show intergranular corrosion attack at the nitric acid concentrations studied. It is desirable that materials for use in nitric acid service are resistant to such corrosion induced degradation. [ABSTRACT FROM AUTHOR]

Abstract: The 9CrODS steel specimens were prepared by different processing with hot-rolling and different cooling rate. The hardness and high-temperature tensile properties were measured. Microstructure was analyzed by means of EBSD inverse pole figure and kernel average miss-orientation angles. The hot-rolled and then air-cooled specimen has the highest tensile strength. The furnace-cooled specimen also has better tensile strength at 700°C than air-cooled specimen at normalized condition. The high-temperature strength of 9CrODS steel is significantly improved with increasing grain size that can be induced by hot-rolling or furnace-slow cooling, where the localized grain boundary deformation can be suppressed. [Copyright &y& Elsevier]

Abstract: Out-of-pile FCCI tests for 9CrODS steel were performed at 973K by using simulated fission products Cs and Te under the oxygen potential in equilibrium with Fe/FeO and Cr/Cr2O3. Al2O3 powder were inserted to reduce a concentration of the Cs and Te in the system; its molar fraction is Cs:Te:Al2O3 =1:1:1000. From EPMA and XRD analyses, Cr2O3 was formed at the most outer layer, which significantly suppressed the fission product corrosion. Cr2Te3 was also produced at the outer layer and interior of 9CrODS steel through liquid Te migration along grain boundaries. It was demonstrated the corrosion depth of 9CrODS steel is between PNC-FMS and PNC316, which were tested as reference. The Cs and Te assisted corrosion of 9CrODS steel was thermodynamically analyzed through the formation of Cs2O, Cs3CrO4, Cr2O3 and Cr2Te3. [Copyright &y& Elsevier]

Brain vasculature forms the blood-brain barrier ( BBB) that restricts the movement of molecules between the brain and blood, but the capillary of the median eminence ( ME) lacks the BBB for secretion of adenohypophysial hormone-releasing peptides. In the present study, we aimed to elucidate whether continuous angiogenesis occurs in the ME of adult mice. By using a mitotic marker, bromodeoxyuridine ( Br dU), we demonstrated that new endothelial cells were born continuously in the ME of adults. Prominent expression of NG2, platelet-derived growth factor receptor B ( PDGFRB), and delta-like ligand 4 was observed at pericytes of adults, although the expression of these angiogenesis-associated proteins has been shown to be at low or trace levels in adult mature capillary. In addition, vascular endothelial growth factor ( VEGF), a key regulator of angiogenesis, was expressed highly in the nervous parenchyma of the ME. Expression of VEGF receptor 2 ( VEGFR2) was observed at endothelial cells in the external zone and at somatodendrites in the internal zone. Finally, a VEGFR- and PDGFR-associated tyrosine kinase inhibitor, SU11248, significantly decreased the number of Br dU-positive proliferating endothelial cells and parenchyma cells. In conclusion, the present study demonstrates VEGF-dependent continuous angiogenesis in the ME of adult mouse brains under normal conditions, which provides new insight into our understanding of neurosecretion in the ME. [ABSTRACT FROM AUTHOR]

Abstract: A combined Large-Eddy-Simulation (LES) – Conditional Moment Closure (CMC) method has been applied to model spray combustion. Additional source terms in the CMC transport equation that originate from the evaporation of the fuel have been modelled and their influence on flame structure and global quantities such as temporally averaged temperature profiles has been analysed. The predictions of a laboratory spray jet flame are generally good, the temperature profiles are in good agreement with measurements, and predictions of droplet velocities are satisfactory. The evaporation source term leads to a flux in mixture fraction space and peak temperatures are shifted towards higher mixture fraction regions. The results, however, also highlight some limitations associated with mixture fraction as a single conditioning variable for mixture fraction based approaches if applied to liquid fuel combustion. [Copyright &y& Elsevier]

The high-temperature oxidation behavior of pure Ni in air and Ar with and without 30 vol%HO at 1,000 °C was investigated to understand the effects of water-vapor on the resulting oxidation kinetics and scale structures. It was found that water-vapor significantly affected the morphology and scale structure of NiO. A duplex NiO scale with a powder-like outer and dense inner NiO layer developed when the Ni was oxidized in atmospheres containing water-vapor. The grain size of the dense inner NiO layer was much smaller than that formed in dry atmospheres. The growth of the powder-like NiO required outward diffusion of Ni and its continued formation occurred at the interface between the powder and dense NiO layers. The dense inner NiO layer grew outward and incorporated the powder-like NiO particles and the resulting grain size of the inner layer was smaller in the presence of water-vapor. The water-vapor is speculated to have prevented sintering of NiO particles during growth of the NiO scale. [ABSTRACT FROM AUTHOR]