Treesearch

We derive the predictive distribution for a specified order statistic, determined from a future random sample, under a Dirichlet process prior. Two variants of the approach are treated and some limiting cases studied. A practical application to monitoring the strength of lumber is discussed including choices of prior expectation and comparisons made to a Bayesian parametric approach.

Water repellents and water-repellent preservatives increase the durability of wood by enabling the wood to repel liquid water. This report focuses on water-repellent finishes for wood exposed outdoors above ground. The report includes a discussion of the effects of outdoor exposure on wood, the characteristics of water repellent and water-repellent preservative formulations, and methods for applying these finishes.

This paper presents an overview of selected research at the Forest Products Laboratory (FPL) to characterize the grade distribution and engineering properties of lumber and timber recycled from deconstructed buildings on US. Army installations. The effects of splits on timber beam and column strength and the effects of damage on lumber grade yield are reported here.

Data suggest that the dimerization of coniferyl alcohol is not under thermodynamic control. In this study, molecular dynamics calculations were used to estimate the effect of the solvent environment. In water, the coniferyl alcohol radicals were forced to associate by the formation of a solvent cage. In glycerol, the solvent cage effect appeared to be absent. These results suggest that in water, the product distribution of the dimers will be modified by interactions with the solvent. The computed results are consistent with experimental observations of coniferyl alcohol reactions in...

Raman spectroscopy is being increasingly used to carry out in situ analysis of wood and other lignocellulosics. To obtain useful information from the spectra, the vibrational bands need to be assigned in terms of contributions from various chemical components and component sub-structures. In additional, so that the technique can be better applied as an analytical tool, an understanding of chemical treatment induced spectral changes is important. In the present work, Raman spectra of four MWLs (black spruce, loblolly pine, aspen, and sweet gum) were compared and, for black spruce MWL,...

It is hard to imagine a world without forests. Forests provide a wide range of benefits at the local, national, and global levels. Some of these benefits depend on leaving the forest alone or subjecting it to only minimal interference. Other benefits can only be realized by harvesting the forest for wood and other products. The shrinking land base and growing human population have heightened the challenge for forestry and forest products utilization to produce the needed types and quantity of trees. The concept of sustainability is central to sound forest management and the subject of much...

When silviculture researchers in central Europe were gathering together to form IUFRO in 1892, forest products researchers were occupied with making useful forest products and conserving the forest resource through wise use. Forest products researchers did not become an active part of IUFRO until 50 years later. Research in forest products was stimulated by World War I and II1wood was essential for airplanes, ships, packaging, construction, and derived products. As World War II drew to a close, the newly established United Nations provided a forum for bringing together efforts that would...

This report describes how lumber can be air-dried most effectively under outdoor conditions and illustrates the principles and procedures of air-drying lumber that were developed through field investigations and observations of industrial practices. Particular emphasis is placed on the yarding of lumber in unit packages. Included are topics such as why lumber is dried, advantages and limitations of the drying process, properties of wood in relation to drying, layout of the drying yard, piling methods, causes and remedies of air-drying defects, and protection of air-dried lumber.

Many specialty treatments can be applied to wood to either improve its performance or change its properties. Treatments addressed in this chapter are those that make permanent changes in the shape of a wood product, improvements in dimensional stability, or improvements in performance through combinations with nonwood resources.

Chemical pulping of kenaf fiber is comparatively new. In this study, bast, core, and whole stalk kenaf fibers were pulped using a soda-AQ pulping process and various pulping conditions. Handsheets were evaluated for density, Canadian standard freeness, brightness, opacity, smoothness, and tensile, burst, and tear indexes and strength. The results indicate that commercially viable pulp can be produced from kenaf using 12% NaOH, 0.15 AQ, and 2 h of cooking at 160*C.