A Comparison of Coated Paper Surfaces by Photomicrography

Five different types of coated papers were photomicrographed, namely cast coated, roll coated, trailing blade coated, air brush coated, and brush coated grades. All cast coated papers were found to be extremely smooth and essentially free of pattern. Roll coated papers displayed a microscopic pattern which resembled the magnified surface of an orange peel. Trailing blade coated papers displayed sharp-edged pits and, in some cases, scuffed surfaces. Air brush coated papers had a microscopic pattern which resembled the non-magnified surface of a pie crust. Brush coated papers closely resembled air brush coated papers microscopically, however, they also carried a macroscopic pattern of brush marks which distinguished them from the air brush coated grades. It was concluded that various types of coating processes leave typical patterns which may be used in conjunction with other characteristics of the paper to identify the particular coating process used

On the Relative Accuracy of Discounting Based on Risk-Free and Risky Portfolios

The degree of risk that should be incorporated into the net discount rate that is used to estimate the present value of future lost earnings has been the subject of controversy. While some forensic economists insist that a risk-free discount rate must be used, others have offered economic arguments that support use of a risk-adjusted rate. Historical simulation studies have found that, when the discount rate is based on risk-free or low-risk securities, the historical averages method of estimating present value is subject to large forecast errors due to significant changes in net discount rates over time. This study explores whether basing the discount rate on mixed portfolios of equities, intermediate- term government bonds, and Treasury bills might result in more accurate estimation. Using the historical averages method with data covering the period 1926-2008, results are generated for four mixed portfolios of varying degrees of risk, and these results are compared to the results obtained with Treasury bills, intermediate-term government bonds and long-term corporate bonds. The historical simulations do show that the mixed portfolios often provide more accurate estimates. These results should be of considerable interest to forensic economists who believe that some degree of risk should be incorporated into the discount rate

Motor brush wear measured with strain gages

Balanced bridge circuit, supplied with low-voltage direct current and connected to a readout device, measures remaining brush material, rate of brush wear, armature runout, and brush signature

Linear Rheological Response of a Series of Densely Branched Brush Polymers

We have examined the linear rheological responses of a series of welldefined, dense, regularly branched brush polymers. These narrow molecular weight distribution brush polymers had polynorobornene backbones with degrees of polymerization (DP) of 200, 400, and 800 and polylactide side chains with molecular weight of 1.4 kDa, 4.4 kDa, and 8.7 kDa. The master curves for these brush polymers were obtained by time temperature superposition (TTS) of the dynamic moduli over the range from the glassy region to the terminal flow region. Similar to other long chain branched polymers, these densely branched brush polymers show a sequence of relaxation. Subsequent to the glassy relaxation, two different relaxation processes can be observed for samples with the high molecular weight (4.4 and 8.7 kDa) side chains, corresponding to the relaxation of the side chains and the brush polymer backbone. Influenced by the large volume fraction of high molecular weight side chains, these brush polymers are unentangled. The lowest plateau observed in the dynamic response is not the rubbery entanglement plateau but is instead associated with the steady state recoverable compliance. Side chain properties affect the rheological responses of these densely branched brush polymers and determine their glassy behaviors