Treesearch

Wood properties in transverse compression are difficult to determine because of such factors as anatomical complexity, specimen geometry, and loading conditions. The mechanical properties of wood, considered as an anisotropic or orthotropic material, are related by certain tensor transformation rules when the reference coordinate system changes its orientation. In this paper, we used our verified shear modulus model to estimate compressive modulus of elasticity in the radial direction by means of certain established tensor transformation rules. The obtained basic engineering constants form...

In wood, the threshold level below which decay cannot occur varies with species or type of wood product and other factors such as temperature, humidity, and propensity of exposure or service-use to allow rain-induced wetting and subsequent drying. The ability to control wood moisture content (MC) during laboratory decay testing could allow research on the moisture thresholds required for the initiation of wood decay over a range ofmoisture conditions. In this study, we modified the soil-pan decay test method to control wood MC by controlling the vermiculite moisture levels. A model was...

Wood is used to produce many products (structural and nonstructural) for applications in which its natural properties are adequate. With the decrease of wood availability and the increase of less durable, younger and faster-growing trees, it is possible to modify wood in various ways to improve the properties, depending on the ultimate application. Wood- polymer composites (WPCs) can be any combination of wood and polymer, from polymer filled with wood fiber to solid pieces of wood filled with polymer. This chapter refers to WPCs made from solid wood such as small pieces of wood or veneer....

Despite the many human uses to which various woods are suited, at a fundamental level wood is a complex biological structure, itself a composite of many chemistries and cell types acting together to serve the needs of the plant. Although humans have striven to understand wood in the context of wood technology, we have often overlooked the key and basic fact that wood evolved over the course of millions of years to serve three main functions in plants: the conduction of water from the roots to the leaves, the mechanical support of the plant body, and the storage of biochemicals. The need...

Fiber-level simulations are employed to probe the relationships between various properties and macroscopic behavior of flexible fiber suspensions. Issues addressed include flocculation, suspension rheology, and handsheet formation and testing. Results show that such simulations can be useful tools for understanding the factors that control the behavior of suspensions.

This paper will present several successful case studies where scale has been eliminated in mills including calcium carbonate scale in a white liquor strainer, calcium oxalate scale in the D0 stage, enzymatic treatment of brown stock to eliminate oxalate scale, and control of barium sulfate scale.

The purpose of this literature review is to give an overview of test methods previously used to evaluate the corrosion of metals in contact with wood. This article reviews the test methods used to evaluate the corrosion of metals in contact with wood by breaking the experiments into three groups: exposure tests, accelerated exposure tests, and electrochemical tests.

Global pulp, paper and paperboard markets improved in 2004 and 2005, as indicated by generally higher prices for most pulp, paper and paperboard products in comparison with 2003. While growth in demand was quite robust in 2004, by the end of the first half of 2005, markets appeared more hesitant and prices appeared to waver or reach a plateau. Within the UNECE region, annual growth in consumption of paper and paperboard halved within the CIS subregion (from 12.9% in 2003 to 6.5% in 2004), while growth rebounded in North America (from –0.7% to 4.5%). Thus, there were converging rates of...

For general linear models with normally distributed random errors, the probability of a Type II error decreases exponentially as a function of sample size. This potentially rapid decline reemphasizes the importance of performing power calculations.

A thin, solid, circular wood disk, cut from the transverse plane of a tree stem, can be modeled as a cylindrically orthotropic elastic material. It is known that a stress singularity can occur at the center of a cylindrically orthotropic disk subjected to uniform pressure. If a solid cylindrically orthotropic disk is subjected to sinusoidal pressure distributions, then other stress singularities can also occur in the disk. The criterion for the existence of these singularities is based on a simple relationship between two dimensionless elastic constant parameters and the sinusoidal...