Treesearch

Cornipulvina ellipsoides is described as a new genus and species in the family Boliniaceae, order Boliniales and Erythromada lanciospora is described as a new genus and species in the Sordariomycetidae. Cornipulvina is distinguished by irregular stromata with long rostrate necks and ellipsoid ascospores lacking a germ pore. Erythromada differs from similar scolecosporous genera in its superficial, clustered, ovoid ascomata and its nonseptate. wider ascospores. Phylogenetic analyses of nuclear 28S large subunit (LSU) sequences supports the establishment of both genera.

We used SilviScan analysis and tracheid measurement to evaluate the effect of suppressed growth on the fundamental properties of wood fiber. Suppressed growth reduced cell tracheid length, but the high content of mature wood may translate into longer fibers overall. In pilot-scale refining experiments, blending 25% chips from small-diameter trees (SMD) with 75% mill wood chips produced slightly better quality pulp compared with pulp from a control mill wood chip sample. The pulp from the SMD mix had slightly lower shives and fines content than that of the control pulp. Handsheets from the...

The properties of any resource are, in general, a result of the chemistry of the components of that resource. In the case of wood, the cell wall polymers (cellulose, hemicelluloses, and lignin) are the components that, if modified, would change the properties of the resource. If the properties of the wood are modified, the performance of the modified wood would be changed. This is the basis of our chemical modification of wood— to change its properties and improve its performance. This idea is applied to both solid wood and wood composites. In order to produce wood-based materials with a...

The term “wood-plastic composites” refers to any number of composites that contain wood (of any form) and either thermoset or thermoplastic polymers. Thermosets or thermoset polymers are plastics that, once cured, cannot be remelted by heating. These include cured resins, such as epoxies and phenolics, plastics with which the forest products industry is most familiar (see Chapter 10). Wood thermoset composites date to the early 1900s. An early commercial composite marketed under the trade name Bakelite was composed of phenol-formaldehyde and wood flour. Its first commercial use was...

The purpose of this chapter is to describe the reasons for the development of ICT and e-business systems in the paper and paperboard packaging industry and to discuss future scenarios that may serve to guide forest- sector research in this topical area. The paper and paperboard packaging industry encompasses producers of primary paper and paperboard packaging materials (paper and paperboard mills) plus secondary producers who convert paper or paperboard into packaging products, such as corrugated containers, boxes, sacks, or other forms of paper or paperboard packaging. Some firms in the...

Wood-plastic lumber is promoted as a low-maintenance, high-durability product. After weathering, however, wood-plastic composites (WPCs) often fade. In the first part of this study, 50 percent woodflour-filled high- density polyethylene (HDPE) composite samples were manufactured. Composites were exposed to two accelerated weathering cycles in a xenon- arc type weathering apparatus: either ultraviolet (UV) light only or UV light and water spray. The composites lightened less when they were exposed to only W light compared with exposure to UV light and water spray. In the second part of this...

Forests, and the wood they produce, have played an important role in human activity since before recorded history. Indeed, one of the first major innovations of humankind was utilizing fire, fueled by wood, for cooking and heating. It is very likely that early hominids used wood fires for cooking as long as 1.5 million years ago (Clark and Harris 1985). Clear evidence of this use of wood exists from sites 400,000 years old (Sauer 1962). Since this ancient beginning, the uses of wood, and the value of the forest, have expanded dramatically, as the population of humans and their economies...

Weathering is the general term used to define the slow degradation of materials exposed to the weather. The degradation mechanism depends on the type of material, but the cause is a combination of factors found in nature: moisture, sunlight, heat/cold, chemicals, abrasion by windblown materials, and biological agents. Tall mountains weather by the complex and relentless action of these factors. All natural and man-made materials weather; for polymeric materials, the weathering rate is considerably faster than the degradation of mountains. Many of the materials we depend on for clothing and...

Over 1.9 × 106 housing units are constructed in the United States in 2004. On a volume basis, wood products comprise almost 80% of all materials used in residential housing. It is estimated that over 7 × 109 m3 of lumber have gone into structures in the United States over the last century. Half of the wood products now used in construction are engineered wood composites. Employing nanotechnology within the forest products industry could result in previously undreamed of growth opportunities for bio-based products. Nanotechnology will result in a unique next generation of wood- based...

Decay can cause significant damage to high-value hardwood timber. New nondestructive evaluation (NDE) technologies are urgently needed to effectively detect incipient decay in hardwood timber at the earliest possible stage. Currently, the primary means of inspecting timber relies on visual assessment criteria. When visual inspections are used exclusively, they provide no indication of the extent of internal deterioration that may exist in timber. In this study, time-of-flight, stress-wave tomography, and micro-drilling resistance methods were investigated for locating incipient decay in...