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A series of experiments was performed to test the appearance of wood samples after treatment and accelerated weathering. In the initial experiments, treatment effects were obscured by the high variability between the wood samples. The wood samples can be characterized, but their properties cannot be changed or controlled. Subsequent experiments were designed using robust and optimal design techniques. The characteristics of the wood samples were measured and included as noise variables. The wood samples were selected and assigned to treatments using the D-optimal criterion. Control-by-noise interaction effects were included in the presumed model where possible. The resulting designs yielded significant treatment effects. Approximately half of the variability in the appearance after weathering can be attributed to the characteristics of the wood samples. After removing the variability due to the wood itself, most of the remaining variability in the appearance of the wood can be attributed to the treatments. Copyright © 2000 John Wiley & Sons, Ltd.

Scanning electron microscopy was used to study the distribution of synthetic resin consolidants after treatment of deteriorated wood samples by vacuum impregnation. These resins included Butvar B98, Acryloid B72, and Butvar B90. After the samples had been completely saturated with consolidant, evidence of resin could be found throughout cross sections taken from them, although examination of the samples showed that the resin was not uniformly distributed. Most strikingly, some tracheids could be observed to have heavy deposits of resin, which in some cases completely filled the cell lumen, while adjacent tracheids contained litde or no resin. The percentage of earlywood tracheids with visible resin deposits in a given sample area was then used as an indicator of resin content. Results showed that there was greater concentration of resin in the surface layers of radial or tangential faces than in the specimen core, as well as a tendency toward increasing concentration toward the end surfaces.

Extended abstract of a paper presented at Microscopy and Microanalysis 2012 in Phoenix, Arizona, USA, July 29 – August 2, 2012.

We present experimental results for the transmission T, haze H, sheet resistance Rs, and its spatial fluctuations ΔRs for silver nanowire films. Mie light scattering theory of nanowires is developed to predict both T and H as a function of diameter D of wires and the surface fraction ϕs covered by the wires. Percolation theory is used to derive an equation for Rs in terms of D, the aspect ratio of wires D/L and ϕs. The critical exponent t for percolation of Rs is found to be 1.23 in close agreement with theoretical results for 2D random resistive networks (t = 1.3). These equations show the importance of both the distributions of diameter ⟨D⟩ and aspect ratio of wires ⟨D⟩⟨L⟩/⟨L2⟩ to predict the optical and electrical properties. Spatial fluctuations ΔRs/Rs can also be significant in these films and be greater than 10% as ϕs approaches the critical percolation concentration ϕc. We show that the calculated T versus Rs and H versus Rs curves are in good agreement with the experimental data. We propose figures of merit for percolating nanowire films in terms of high T, low H, and low Rs to order the quality of films for touch screen applications. The results show that D 5 μm are needed to achieve low haze H 90%, together with low Rs ∼ 100 Ω/sq for touch screen applications. Finally, we present experimental and theoretical results of the real and imaginary refractive indices of AgNW/polymer nanocomposites, and find that the Van De Hulst model is more accurate than the Maxwell Garnett models.