Treesearch

Time series data frequently used in Forest Service studies of wood products consumption have been stored in a data retrieval system on the computer of the University of Wisconsin. The data cover activity in wood processing from forest to end use. Prices and costs at succeeding stages, historical usage, production rates, and other relevant data to wood use analysis were compiled. The system is available on-line and may be accessed directly or the data may be obtained in printed form by interested users.

Ninety glued-laminated Douglas-fir or southern pine beams of a uniform grade with 2-, 4-, or 6-laminations were evaluated in static bending tests. No specially graded tension laminations or end joints were used. The purpose of the tests was to determine which of three present design criteria best predict near minimum bending strength values for shallow glued-laminated (glulam) beams. A variation of a strength ratio concept, with an applied adjustment factor of 0.85, was found to predict the near- minimum strengths more accurately than the IK/IG concept now used for deep beams. Because a...

Gayella splendens (A. DC.) Aubr., the sole member of this genus, is a tall shrub, endemic to Chile. Baehni and Eyma place G. splendens in Pouteria but Aubréville recognizes Gayella as distinct. Anatomically, the alliance of Gayella is not with Pouteria but with Pradosia and particularly with lactescens and ptychandra.

Candida tropicalis converts xylose to ethanol under aerobic, but not anaerobic, conditions. Ethanol production lags behind growth and is accelerated by increased aeration. Adding xylose to active cultures stimulates ethanol production as does serial subculture in a medium containing xylose as a sole carbon source.

In pulp processing development it is often necessary to measure the effect of a process variable on individual pulp fiber wettability. Such processes would include drying of market pulps, recycling of secondary fibers, and surface modification of fibers as in sizing. However, if wettability is measured on a fiber sheet surface, the results are confounded by variations in fiber network morphology.

The quinone methide from guaiacylglycol-ß-guaiacyl ether underwent nucleophilic addition to the a-carbon with primary and secondary amines at 40°C. At pulping temperature, 170°C, only the primary amine adduct was detected. The quinone methide from guaiacylglycerol-ß-guaiacyl ether gave analogous adducts at 40°C, but no quinone methide-amine adducts were detected at 170°C. Instead, the major products were the vinyl ether and a substituted vinyl ether which resulted from a Mannich reaction of the vinylether, amine, and liberated formaldehyde.

An American wood. Description of the distribution, growth, habit, wood, and wood properties of the species. Includes bibliographical references.

An American wood. Description of the distribution, growth, habit, wood, and wood properties of the species. Includes bibliographical references.

Present building codes and standards are a combination of specifications and performance criteria. Where specifications prevail, the introduction f new materials or methods can be a long, cumbersome process. To facilitate the introduction of new technology, performance requirements are becoming more prevalent. In some areas, there is a lack of information on which to base acceptable performance. As background information, existing major codes and standards were surveyed. Existing criteria are listed for each aspect of construction under major headings of structural and environmental. A...

There is a growing demand for natural exterior wood finishes that retain the original attractive appearance of wood with the least change in color and masking of grain. A number of experimental finishes are being evaluated for their performance in the cool, moist climate of Olympia, Wash. This study, started in 1966, has included observations on the weathering performance of 48 experimental finishes, both transparent and pigmented. Of these, 36 are still on exposure and inspected annually. Generally, water-repellent preservatives are the least durable of the natural finishes. Pentachlorophe...