Intelligent Integrated Model for Improving Performance in Power Plants

Zirconia oxygen sensors, in such applications as power plants and automobiles, generally utilize platinum electrodes for the catalytic reaction of dissociating O2 at the surface. The microstructure of the platinum electrode defines the resulting electrical response. The electrode must be porous enough to allow the oxygen to reach the zirconia surface while still remaining electrically continuous. At low sintering temperatures, the platinum is highly porous and fine grained. The platinum particles sinter together as the firing temperatures are increased. As the sintering temperatures are raised even further, the surface of the platinum begins to facet with lower energy surfaces. These microstructural changes can be seen in Figures 1 and 2, but the goal of the work is to characterize the microstructure by its fractal dimension and then relate the fractal dimension to the electrical response. The sensors were fabricated from zirconia powder stabilized in the cubic phase with 8 mol% percent yttria. Each substrate was sintered for 14 hours at 1200°C. The resulting zirconia pellets, 13mm in diameter and 2mm in thickness, were roughly 97 to 98 percent of theoretical density. The Engelhard #6082 platinum paste was applied to the zirconia disks after they were mechanically polished ( diamond). The electrodes were then sintered at temperatures ranging from 600°C to 1000°C. Each sensor was tested to determine the impedance response from 1Hz to 5,000Hz. These frequencies correspond to the electrode at the test temperature of 600°C.

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The Effects of Ion Implantation on the Surface Features of Inconel 600

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100118333 ◽

1985 ◽

Vol 43 ◽

pp. 288-289

Author(s):

John D. Rubio

Keyword(s):

Grain Boundary ◽

Ion Implantation ◽

Nuclear Power ◽

Power Plants ◽

Surface Region ◽

Selective Dissolution ◽

Boundary Region ◽

Near Surface ◽

Inconel 600 ◽

Steam Generator Tubing

The degradation of steam generator tubing at nuclear power plants has become an important problem for the electric utilities generating nuclear power. The material used for the tubing, Inconel 600, has been found to be succeptible to intergranular attack (IGA). IGA is the selective dissolution of material along its grain boundaries. The author believes that the sensitivity of Inconel 600 to IGA can be minimized by homogenizing the near-surface region using ion implantation. The collisions between the implanted ions and the atoms in the grain boundary region would displace the atoms and thus effectively smear the grain boundary.To determine the validity of this hypothesis, an Inconel 600 sample was implanted with 100kV N2+ ions to a dose of 1x1016 ions/cm2 and electrolytically etched in a 5% Nital solution at 5V for 20 seconds. The etched sample was then examined using a JEOL JSM25S scanning electron microscope.

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Multilinguistic Components of Spelling: An Overview

Perspectives on Language Learning and Education ◽

10.1044/lle20.4.124 ◽

2013 ◽

Vol 20 (4) ◽

pp. 124-128 ◽

Cited By ~ 5

Author(s):

Angela Barber

Keyword(s):

Integrated Model ◽

Literacy Skills ◽

Speech Language Pathologists ◽

Language System ◽

Adequate Information ◽

Intervention Plan ◽

Semantic Awareness

Spelling is a window into a student's individual language system and, therefore, canprovide clues into the student's understanding, use, and integration of underlyinglinguistic skills. Speech-language pathologists (SLPs) should be involved in improvingstudents' literacy skills, including spelling, though frequently available measures ofspelling do not provide adequate information regarding critical underlying linguistic skillsthat contribute to spelling. This paper outlines a multilinguistic, integrated model of wordstudy (Masterson & Apel, 2007) that highlights the important influences of phonemicawareness, orthographic pattern awareness, semantic awareness, morphologicalawareness and mental graphemic representations on spelling. An SLP can analyze anindividual's misspellings to identify impairments in specific linguistic components andthen develop an individualized, appropriate intervention plan tailored to a child's uniquelinguistic profile, thus maximizing intervention success.

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