Author: T. E. McLainPublisher:
ISBN:
Category : Lumber
Languages : en
Pages : 48
Book Description
The Influence of Moisture Content on the Flexural Properties of Southern Pine Dimension Lumber
Author: T. E. McLainThe Influence of Moisture Content on the Flexural Properties of Douglas Fir Dimension Lumber
Author: Research Paper FPL
Author: Long-term Load Performance of Hardboard I-beams
Author: J. Dobbin McNattPublisher:
ISBN:
Category : Girders
Languages : en
Pages : 688
Book Description
Wood-Water Relations
Author: Christen SkaarPublisher: Springer Science & Business Media
ISBN: 3642736831
Category : Technology & Engineering
Languages : en
Pages : 292
Book Description
Wood is formed in an essentially water-saturated environment in the living tree, and the cell wall remains in this state until the water flow from the roots is interrupted, such as by felling the tree. The wood then begins to lose most of its moisture by drying, resulting in changes in most of its physical properties. These changes, and their relationship to the environment to which the wood is subsequently ex posed, are the subject of this book. The text consists of six chapters. The first chapter discusses cer tain empirical relationships between wood and water, methods of measuring wood moisture content, factors which affect its equilib rium moisture content, and the effect of moisture content on wood strength. The second chapter treats the thermodynamics of moisture sorption by wood, inc1uding enthalpy, entropy, and free energy changes. The third chapter discusses some of the theories which have been proposed to explain the sorption isotherms for hygroscopic ma terials such as wood. Chapter 4 considers hygroexpansion or the shrinking and swelling of wood associated with moisture change. Chapter 5 is concerned with how moisture moves through the cell wall of wood in response to both moisture and temperature gradients. The sixth and final chapter discusses the theoretical and practical aspects of the electrical resistance and dielectric properties of wood, in c1uding the principles involved in their application in electrical moisture meters.
Confidence Intervals for Predicting Lumber Strength Properties Based on Ratios of Percentiles from Two Weibull Populations
Author: Richard Arnold JohnsonPublisher:
ISBN:
Category : Confidence intervals
Languages : en
Pages : 12
Book Description
Ratios of strength properties of lumber are commonly used to calculate property values for standards. Although originally proposed in terms of means, ratios are being applied without regard to position in the distribution. It is now known that lumber strength properties are generally not normally distributed. Therefore, nonparametric methods are often used to derive property values. In some situations, estimating properties based on a parametric estimate is required. For these situations, the three-parameter Weibull distribution looks promising. To use this approach, procedures for estimating confidence intervals for ratios of percentiles from two Weibull populations are needed. In this study, we employed the large sample properties of maximum likelihood estimators to obtain a confidence interval for the ratio of 100Sa-th percentiles from two different three-parameter Weibull distributions. The coverage probabilities were investigated by a computer simulation study. We concluded that the procedure has considerable promise, but many questions remain to be answered.
Current Topics in Forest Research
Author: Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 208
Book Description
Thirty-four papers are presented in nine categories: silviculture/ecology, genetics, soils and nutrients, regeneration, forest products, sociology, economics, policy, and insects and diseases. Also included is the keynote address, "Women in natural resources," by R. Max Peterson
Research Paper FPL-RP
Author: Making Our Forests and Rangelands More Productive
Author: General Technical Report WO.
Author: Publisher:
ISBN:
Category : Forests and forestry
Languages : en
Pages : 432
Book Description