Measuring country exchange rates relative to a common reference basket results in a set of no-arbitrage prices, unlike trade-weighted indexes, the usual method of comparing country exchange rate histories. The reference basket is analogous to a portfolio, and its choice can be resolved by drawing on required economic interpretations or uses. We use currency reference rates to examine the historical variability of different currencies over designated cyclical bands. The temporal decompositions used are those provided by wavelet analysis, which is light on maintained assumptions about data generating processes. Some countries, notably Japan and New Zealand do exhibit a powerful but irregular medium term cycle, while others are much more stable. Implications are briefly examined for investment, hedging, monetary policy and common currency studies.
This study evaluated the quality of kraft pulp from budworm-infested jack pine. The logs were classified as merchantable live, suspect, or merchantable dead. Raw materials were evaluated through visual inspection, analysis of the chemical composition, SilviScan measurement of the density, and measurement of the tracheid length. Unbleached pulps were then refined using a laboratory disk refiner. The mechanical and optical properties of handsheets made from the refined pulps were evaluated. Although budworm galleries may affect the physical integrity of the wood, they have no effect on pulp quality. Blue stain did not affect the handsheet brightness. The results indicate that merchantable dead jack pine trees are acceptable for kraft pulp production, with equivalent pulp yield.
Quinone methides were produced in aqueous solution by photochemical dehydration of o-hydroxybenzyl alcohols (o-HOC6H4CHROH; R = H, C6H5, 4-CH3OC6H4), and flash photolytic techniques were used to examine their rehydration back to starting substrate as well as their interaction with bromide and thiocyanate ions. These reactions are acid-catalyzed and show inverse isotope effects (kH+/kD+ < 1), indicating that they occur through preequilibrium protonation of the quinone methide on its carbonyl carbon atom followed by rate-determining capture of the benzyl carbocations so formed by H2O, Br-, or SCN-. With some quinone methides (R = C6H5 and 4-CH3OC6H4) this acid catalysis could be saturated, and analysis of the data obtained in the region of saturation for the example with R = 4-CH3OC6H4 produced both the equilibrium constant for the substrate protonation step and the rate constant for the rate-determining step. Energy relationships comparing the quinone methides with their benzyl alcohol precursors are derived.