Browsing by Author "Erickson, John R"

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    Heat Sterilization Times of Five Hardwood Species: Stress Wave E-Rating of Specimens
    (University of Minnesota Duluth, 2004-09) Wang, Xiping; Forsman, John W; Erickson, John R
    Heat Sterilization of lumber, timbers and pallets is currently used to kill insects to prevent their transfer between countries in international trade. A typical requirement is that the center of any wood configuration be held at 133 °F (56 °C) for 30 min. However, the time required for the center to reach this temperature can vary widely depending on a number of factors such as wood species, physical prope1iies, cross-sectional dimensions, and heating medium, etc. The overall objective of this project was to quantify the effects of wood species, cross-sectional dimension, and heating medium on the time required to heat the center of hardwood lumber and timbers to 133 °Fat a heating temperature of 160 °F (71 °C). A stress wave E-rating procedure was also added to examine if the stress wave properties of lumber and timbers can be any useful in predicting heating times for untested species in the future.
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    Low Frequency Vibration Approach to Assess the Performance of Wood Structural Systems
    (University of Minnesota Duluth, 2003-10) Wang, Xiping; Ross, Robert J; Erickson, John R; Forsman, John W
    The primary means of inspecting buildings and other structures is to evaluate each structural member individually. This is a time consuming process that is expensive, particularly if sheathing or other covering materials must be removed to access the structural members. This report presents an effort to use a low frequency vibration method for assessing the structural performance of wood floor systems.