Treesearch

In this report, we assess the unmitigated pest risk potential of importing Eucalyptus logs and chips from South America into the United States. To do this, we estimated the likelihood and consequences of introducing representative insects and pathogens of concern. Nineteen individual pest risk assessments were prepared, eleven dealing with insects and eight with pathogens. The selected organisms were representative examples of insects and pathogens found on the foliage, on the bark, in the bark, and in the wood of Eucalyptus spp. Among the insects and pathogens assessed, eight were rated a...

These standardized bridge plans are for superstructures consisting of treated timber. Seven superstructure types are includes: five longitudinal and two transverse deck systems. Both HS520 and HS25 loadings are included, along with L/360 and L/500 deflection criteria.

ASTM D1990, “Establishing Allowable Properties for Visually Graded Dimension Lumber from In-Grade Tests of Full-Size Specimens,” is the consensus standard used to make submissions of allowable properties for many U.S., Canadian, and foreign species to the Board of Review of the American Lumber Standards Committee. Recently, it has become apparent how difficult it is to perform the calculations for such a submission. Some calculations are clearly specified in the standard; in some cases the standard merely indicates a need to make an adjustment but does not specify how to do so. This report...

Will the National Forests become a more reliable supplier of timber again in conjunction with the National Fire Plan? The National Forests represent a major potential source of wood fiber in the West. They occupy 48% of the commercial forestland, hold 63% of the region?s softwood growing stock, and contribute 48% of its net annual growth. But in California, Idaho, Montana, Oregon, and Washington, timber sales have declined from an average of 8 billion board feet per year during 1960-1 990 to about 1.5 billion board feet since. The new millennium saw the lowest volumes offered since the...

Stress-wave-based nondestructive evaluation methods were used to evaluate the potential quality and modulus of elasticity (MOE) of wood from creosote-treated Douglas-fir and southern pine piles removed from service. Stress-wave measurements were conducted on each pile section. Stress-wave propagation speeds were obtained to estimate the MOE of the wood. Tests were then conducted on octagonal cants, boards, and small clear specimens obtained from piles and cants. Regression analyses gave a reasonably useful correlation between the stress-wave-based MOE of piles and cants and the correspondin...

Trends in the stability of ¥á and ©¬-Keggin heteropolytungstates of the second-row main-group heteroatoms Al(III), Si(IV), and P(V) are elaborated by data that establish the roles of kinetic and thermodynamic control in the formation and isomerization of Keggin tungstoaluminates. Slow, room-temperature co-condensation of Al(III)and W(VI) (2:11 molar ratio) in water gives a pH 7 solution containing ©¬1 and ©¬2 isomers of [Al(AlOH2)W11O39]6-(©¬1- and ©¬2=1). Partial equilibration of this kinetic product mixture by gentle heating (2 h at 100¡ÆC) or, alternatively, co-condensation of Al(III)...

Small-diameter and underutilized (SDU) material refers to the timber that is left in the forest because it is not economical to remove, or local capacity to process it does not exist. SDU material also includes the dense, understory present through-out the forest as a result of 50 years of successful fire suppression. It has become apparent that there are many beneficial forest management reasons why this material should be removed, including reducing fire hazards, altering the stand species and quality mix to a more desirable composition, providing healthier wildlife habitat, and protectin...

This report describes the long-term performance of painted window units that were placed outdoors near Madison, Wisconsin, in 1956. Covered in this report are the effects of the initial water repellent preservative (WRP) treatment during the first 6 years of exposure, a comparison of the water repellent effectiveness (WRE) ofthe WRP with the condition of the windows after 32 years, restoration of the windows after 32 years, paint performance after the restoration, and the final evaluation for decay after 45 years. There was no correlation between the WRE of the treating solutions as...

From an early status as a “weed tree,” poplar has become an important commercial genus in North America during the past 20 years. The many and varied uses of poplar wood now include pulp and paper, lumber, veneer, plywood, composite panels, structural composite lumber, containers, pallets, furniture components, match splints and chopsticks.The high cellulose and relatively low lignin content make poplars well suited for pulp and paper products. Thewood can be pulped by all commercial pulping methods, such as mechanical, semi-chemical, sulphate and sulphite processes. Poplar pulps are...

Wood is a thermally degradable and combustible material. Applications range from a biomass providing useful energy to a building material with unique properties. Wood products can contribute to unwanted fires and be destroyed as well. Minor amounts of thermal degradation adversely affect structural properties. Therefore, knowledge of the thermal degradation and fire performance of wood can be critical in many applications. Chemical treatments are available to improve fire performance characteristics.