Treesearch

A timber bridge, once a thing of the past, is now becoming a thing of the present. Interest in timber bridges and other transportation structures has been rapidly increasing. Much of this is due to new technologies in design and construction as well as advances in material manufacturing and presevative treatments. Although timber bridges and other transportation structures are gaining in popularity, there is much to be accomplished to fully develop wood as a material for transportation structures. This report summarizes research needs determined and prioritized by public and private...

This report presents a worldwide overview of the dissolving pulp industry and highlights of this industry in Alaska. It describes trends in world markets and major end-use markets, with special emphasis on the manufacture and use of textile fibers in the United States. Figures and tables present data on production, consumption, and trade of dissolving pulp and the cellulosic fibers-rayon and acetate-produced from it. Data are also given on the production and use of competing natural and synthetic fibers, such as cotton, silk, nylon, and polyester.

This document provides over 4,000 citations from the world literature on forest products for Latin America. Citations are grouped in 11 subject areas, with emphasis on products made directly from wood. Excluded are nonwood products such as rattan, bamboo, nuts, fruits, honey, and mushrooms. Also excluded are services from the forest, such as watershed protection, recreation, tourism, and wildlife. Primary sources of citations include USDA-AGRICOLA, CAB, and Forest Products Society’s FOREST (AIDS) system, which were searched electronically. Citations prior to the late 1960s were obtained by...

To help foster rural economic development in 18 Northeastern states, an economic information system developed at the USDA Forest Service, Forest Products Laboratory was used to facilitate access to reference data on forest products industry activities. The Census and Survey of Manufactures were used as sources for information. This report explains the computerized system and provides instruction for users.

Basidiomycetes are the most conspicuous fungi on wood and are the main decomposers. Lignicolous basidiomycetes include white-rotters that remove both lignin and cellulose, and brown-rotters that remove only the cellulose and hemicellulose. The South is a region of diverse lignicolous basidiomycetes because it is the northern limit for many tropical and subtropical taxa and the southern limit for many north temperate taxa. Niches for various taxa are defined by host, substrate, size, and degree of decay. Hence, diversity of these fungi can be enhanced by a mixture of woody angiosperm and...

This report reviews the basis for determining values for the density of wood as it depends on moisture content and specific gravity. The data are presented in several ways to meet the needs of a variety of users.

This report reviews historical price trends of nonconiferous and tropical sawlogs and tropical sawnwood imports to several major consuming regions of the world. Data on real prices for imports from Africa, Asia, and Latin America to the United States, Europe, and Japan are presented as a reference for policymakers interested in the relative price movements of tropical wood products. The discussion includes an assessment of the data with particular emphasis on indications of economic scarcity evidenced by increasing real price trends. Average real prices of tropical logs doubled in the past...

The use of paraffin wax to reinforce the loading edges of corrugated fiberboard edge-crush specimens requires that the specimens be reconditioned after waxing. The traditional practice employing a 24-h reconditioning period is a conservative approach based on the moisture response rate of corrugated containers. An interlaboratory study was conducted to determine the effect of reconditioning time on edgewise compressive strength of waxed specimen prepared by standard test methods. Results showed that reconditioning time can be reduced from 24 h to 2 h with no significant change in test...

This report analyzes the implied reliability of current practice for the design of bolted wood connections. All U.S. data available to the writer were used. The resistance distribution was taken to be normal. and the coefficient of variation was obtained by pooling data from several sources. as long as the moisture condition. grain direction. side-plate material, and species were alike. The reliability index for softwood connections is about 5; the index for hardwood connections is about 20% greater than that for softwood connections. A comparative study of data from six sources showed...

In 1991, Ylinen’s column equation was adopted for the design of wood columns in the United States. Ylinen originally derived this equation as a plasticbuckling criterion, using a nonlinear compressive stress-strain law as the startingpoint. The stress-strain law contained a parameter c ≤ 1, which controlled the degree of nonlinearity. Linearity was achieved at c = 1. This same parameterappeared in the final column equation. At c = 1. the column equation reduced to elementary theory, i.e., to a perfectly plastic-perfectly elastic failure criterion. Column design equations are viewed in this...