Effect of Steaming on Some Physical and Chemical Properties of Black Walnut Heartwood

The influence of steaming time and temperature on some physical and chemical properties of black walnut heartwood was studied. One-inch cube sample blocks were steamed at two different temperatures and four different times, and the pH, surface tension, and color of the wood fluids, as well as the extractives and area of cell lumina, were determined.The pH and surface tension were not affected enough by steaming to be related to color changes of wood, swelling the wood beyond that normally expected in water at room temperature, or reducing drying defects. Prolonged and high temperature (above 100 C) steaming increased alcohol-benzene extractives of the steamed wood. Prolonged and high temperature steaming caused cell walls to swell beyond that in water at room temperature, especially in earlywood. Steaming temperature and time were highly effective in changing the color of wood fluids

Oscillating Rim Hook Tableaux and Colored Matchings

Motivated by the question of finding a type B analogue of the bijection between oscillating tableaux and matchings, we find a correspondence between oscillating m-rim hook tableaux and m-colored matchings, where m is a positive integer. An oscillating m-rim hook tableau is defined as a sequence $(\lambda^0,\lambda^1,...,\lambda^{2n})$ of Young diagrams starting with the empty shape and ending with the empty shape such that $\lambda^{i}$ is obtained from $\lambda^{i-1}$ by adding an m-rim hook or by deleting an m-rim hook. Our bijection relies on the generalized Schensted algorithm due to White. An oscillating 2-rim hook tableau is also called an oscillating domino tableau. When we restrict our attention to two column oscillating domino tableaux of length 2n, we are led to a bijection between such tableaux and noncrossing 2-colored matchings on $\{1, 2,..., 2n\}$, which are counted by the product $C_nC_{n+1}$ of two consecutive Catalan numbers. A 2-colored matching is noncrossing if there are no two arcs of the same color that are intersecting. We show that oscillating domino tableaux with at most two columns are in one-to-one correspondence with Dyck path packings. A Dyck path packing of length 2n is a pair (D, E), where D is a Dyck path of length 2n, and E is a dispersed Dyck path of length 2n that is weakly covered by D. So we deduce that Dyck path packings of length 2n are counted by $C_nC_{n+1}$.Comment: 15 pages, 16 figure