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Fire safety is an important concern in all types of construction. The high level of national concern for fire safety is reflected in limitations and design requirements in building codes. These code requirements are discussed in the context of fire safety design and evaluation in the initial section of this chapter. Since basic data on fire behavior of wood products are needed to evaluate fire safety for wood construction, the second major section of this chapter covers fire performance characteristics of wood products. The chapter concludes with a discussion of flame-retardant treatments...

Glued structural members are manufactured in a variety of configurations. Structural composite lumber (SCL) products consist of small pieces of wood glued together into sizes common for solid-sawn lumber. Glued-laminated timber (glulam) is an engineered stress-rated product that consists of two or more layers of lumber in which the grain of all layers is oriented parallel to the length of the lumber. Glued structural members also include lumber that is glued to panel products, such as box beams and I- eams, and structural sandwich construction.

Our understanding of the diversity of native celluloses has been limited by the fact that studies of their structures have sought to establish ideal crystal lattice forms for the native state. Departures from ideal structures in the native state are viewed as defects in the ideal lattice. In most instances real celluloses have been regarded as departing from the ideal structures primarily with respect to the degree of disorder. The disorder is considered as imparting an amorphous character to part of the cellulose and methods are sought to quantify the bamorphousc fraction. In contrast,...

Hydrolysis of bordered and pinoid pits may be a key event during colonization of wood by decay fungi. Although pits are numerous, studies of pectin-hydrolyzing enzymes in wood decay fungi are scarce, probably because of the relatively low content (less than 4 %) of pectin in wood and because of the primary focus on understanding the degradation of lignified components. Endopolygalacturonase (endo- PG) activity was estimated by cup-plate assay and viscosity reduction of pectin from liquid cultures of fifteen brown-rot and eight white-rot basidiomycetous fungi using sodium polypectate as the...

The objective of this study was to investigate the influence of the phenol-formaldehyde resin content level (3 percent and 7 percent), and three fungi species (Poria placenta, Gleophyllum trabeum, and Polyporus versicolor) on the dimensional stability and decay resistance of high density composition boards made from plantation-grown southern pine chips. A standard ASTM method was used to evaluate weight loss and thickness change. The linear shrinkage and expansion of each species were also determined. All specimens were exposed to decay chambers for 16 weeks. Test results indicated that...

The development of grade standards for recycled timber and lumber will aid in reclaiming the value of wood.

To enhance appearance, stains are often sprayed onto western hemlock (Tsuga heterophylla (Raf.) Sarg.) lumber prior to treatment with chromated copper arsenate (CCA-C). Recently, concerns have increased that prestaining may affect the rate of leaching of CCA-C components from the treated wood and that leaching data generated with prestained material may not reflect the rate of release from nonstained wood. A secondary concern is that copper naphthenate field treatments applied to wood exposed during construction may contribute to the amount of copper released from CCA-C-treated structures....

Published spectroscopic observations pertaining to the crystal structure of native celluloses are reviewed for the purpose of defining our current level of understanding about crystalline polymorphism in these materials. Emphasis is placed on observations from solid state 13 C nuclear magnetic resonance (NMR), which first led to the postulate that most native, semicrystalline celluloses are composites of two crystalline allomorphs, labeled I a and I b . Historical background is presented, highlighting the structural controversies which mainly arose because different native celluloses were...

The concept of land expectation value developed by Martin Faustmann may serve as a paradigm for outcome-based performance measures in public forest management if the concept of forest equity value is broadened to include social and environmental benefits and costs, and sustainability. However, anticipation and accurate evaluation of all benefits and costs appears to present significant challenges, as revealed in the history of public forest policy in the United States. While public forest managers are unlikely to adopt performance measures based on forest equity value, an understanding of...

Ultrafiltration was investigated as a means to remove flexographic ink pigments from wash filtrate effluent generated from various mixtures of flexographic and offset old newspapers from deinking operations. Membrane separation efficiency was assessed from permeate flux, fouling rate, and ease of membrane regeneration (cleaning). Ultrafiltration was capable of completely removing ink pigments from effluent streams. Permeate flux decreased significantly with time due to membrane fouling and concentration polarization. Flocculation by acidification of the flexographic ink of effluents...