Treesearch

RIPYLD is a computer program that optimizes the cutting yield from multiple-ripped boards. Decisions are based on automatically collected defect information, cutting bill requirements, and sawing variables. The yield of clear cuttings from a board is calculated for every possible permutation of specified rip widths and both the maximum and minimum percent yield solutions are saved. Solutions include rip cut and crosscut locations as well as the percent yield of clear cuttings.

Ultrasonics, the technology of high-frequency sound, has been developed as a viable means for locating most defects In lumber for use in digital form in decision-making computers. Ultrasonics has the potential for locating surface and internal defects in lumber of all species, green or dry, and rough sawn or surfaced.

Reliability analysis is a mathematical technique for appraising the design and materials of engineered structures to provide a quantitative estimate of probability of failure. Two or more cases which are similar in all respects but one may be analyzed by this method; the contrast between the probabilities of failure for these cases allows strong analytical focus on the case differences. This comparative procedure is known as differential reliability analysis. The technique is demonstrated by means of an example involving a simple truss member. Applications of reliability analysis important...

Twelve-foot and 6-foot I-beams with webs of two different hardboard materials and plywood were subjected to constant loads in three different humidity environments. After 17,000 hours of test, the performance of the hardboard-webbed I-beams appears to be at least comparable to that of I- beams with plywood webs. Results of this study will be useful to researchers, designers, and building code officials for judging the acceptability of woodbase materials in structural components such as I- beams.

In the neotropics, the genus Chrysophyllum consists of C. cainito and a number of species which have recently been assigned to the genus Cynodendron. Many taxonomists have not accepted the new genus Cynodendron and this is supported by the present study of the wood anatomy. In this restricted sense, Chrysophyllum consists of a group of closely related species that are readily identifiable by their anatomical structure.

The old genus Chloroluma has been reinstated to generic status after having been in synonomy under Chrysophyllum for many years. The description is based on the type species C. gonocarpa which is characterized by: Its clear yellow wood; pores in radial-echelon arrangement; rhombic, two-sized, and microcrystals frequent in the axial parenchyma and wood rays; colored cell contents and silica lacking; very large crystals occasionally found in the tyloses.

The mobile home industry is a large and expanding lumber market within the housing industry. A sturdy wood frame lies under the metal wall and roof skin found on most mobile home units. When compared with data compiled in 1970 (1), the latest Forest Service, Department of Agriculture survey findings indicate the average mobile home now uses much more lumber for framing. This increase in lumber usage is attributed to larger units and better quality construction--with the quality factor generally thought to be most important. Better quality homes with sturdier framing are produced now...

This report has been prepared to supplement Federal Specification TT-W-571 “Wood Preservation: Treating Practices.” developed for the General Services Administration by the U.S. Department of Agriculture, Forest Service, Forest Products Laboratory, the Specification is used by Federal agencies, State agencies, and private users in procuring preservative-treated wood. The economical and practical procurement of treated wood demands a knowledge of wood deterioration and means of protection. The U.S. Forest Products Laboratory, the nation’s center for wood utilization research, has studied...

Describes a new technique for softening wood, using a 4 percent solution of ethylenediamine; a shortcut method for removing silica and crystalline materials with hydrofluoric acid; a method for rapidly neutralizing wood blocks which have been treated with hydrofluoric acid; and a method for maintaining the flatness of sections through staining, dehydration, and clearing. Methods described are applicable to wood with a specific gravity in excess of 0.75.

A methanol-from-wood waste facility having a capacity of 50 million gallons per year requires 1,500 ovendry tons (ODT) of wood waste per day. The yield of methanol from wood is about 38 percent, or about 100 gallons per ODT of wood. This yield is based on all process energy required coming from the wood waste. At a wood waste cost of $15/ODT, the selling price of methanol is estimated at $0.77/gal; at $34/ODT, the selling price is $0.96/gal.