29 research outputs found
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Abstracted model for ceramic coating
Engineers are exploring several mechanisms to delay corrosive attack of the CAM (corrosion allowance material) by dripping water, including drip shields and ceramic coatings. Ceramic coatings deposited with high-velocity oxyfuels (HVOF� s) have exhibited a porosity of only 2% at a thickness of 0.15 cm. The primary goal of this document is to provide a detailed description of an abstracted process-level model for Total System Performance Assessment (TSPA) that has been developed to account for the inhibition of corrosion by protective ceramic coatings. A second goal was to address as many of the issues raised during a recent peer review as possible (direct reaction of liquid water with carbon steel, stress corrosion cracking of the ceramic coating, bending stresses in coatings of finite thickness, limitations of simple correction factors, etc.). During the periods of dry oxidation (T 2 100°C) and humid-air corrosion (T I 100°C & RH 80%), it is assumed that the overall mass transfer resistance governing the corrosion rate is due to the combined resistance of ceramic coating & interfacial corrosion products. Two porosity models (simple cylinder & cylinder-sphere chain) are considered in estimation of the mass transfer resistance of the ceramic coating. It is evident that substantial impedance to 02 transport is encountered if pores are filled with liquid water. It may be possible to use a sealant to eliminate porosity. Spallation (rupture) of the ceramic coating is assumed to occur if the stress introduced by the expanding corrosion products at the ceramic- CAM interface exceeds fracture stress. Since this model does not account for the possibility of corrosion products filling pores, it is believe to be very conservative. In such a case, the corrosion product would not spread across the ceramic-CAM interface and no spallation would occur. Thus, the coating would be expected to last indefinitely
The international synchronisation of business cycles: the role of animal spirits
Business cycles among industrial countries are highly correlated. We develop a two-country behavioral macroeconomic model where the synchronization of the business cycle is produced endogenously. The main channel of synchronization occurs through a propagation of “animal spirits”, i.e. waves of optimism and pessimism that become correlated internationally. We find that this propagation occurs with relatively low levels of trade integration. We do not need a correlation of exogenous shocks to generate synchronization. We also empirically test the main predictions of the model
Then Rushed In Sanitary Trucks . . .
Photograph used for a story in the Daily Oklahoman newspaper
[Photograph 2012.201.B1008.0653]
Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Moss Patterson holds Dan Larry D 4 herd sire of the Lazy S ranch's registered Herefords. This $8,500 bull has been champion of many Herford shows.
[Photograph 2012.201.B0246.0068]
Photograph taken for a story in the Daily Oklahoman newspaper. Caption: "This is headquarters of the Cravens Hereford Ranch north of Oklahoma City.
[Photograph 2012.201.B0246.0063]
Photograph taken for a story in the Daily Oklahoman newspaper. Caption: "Rancher manager Al Wamboldt and herdsman Harvey Joe Burns hold CR Baca Prince I and CR Baca Duchess 70, a bull and heifer in the Cravens ranch show herd, while R. D. Cravens looks on.
[Photograph 2012.201.B1267.0416]
Photograph used for a story in the Daily Oklahoman newspaper. Caption: "Beaver County agent Bill Strom, left, compares heads of standard grain sorghum with loose open head of commercial hybrid grown this year by Lyle Wheeler.
[Photograph 2012.201.B0246.0062]
Photograph taken for a story in the Daily Oklahoman newspaper. Caption: "Mr. and Mrs. Cravens look over the guest book showing names of visitors and cattle customers.