Treesearch

Continuous exterior insulation on above-grade walls is becoming more common in many parts of North America. It is generally accepted that exterior insulation provides advantages for energy performance, by reducing thermal bridging, and for moisture performance, by warming the wood structural members, thereby reducing the potential for wintertime moisture accumulation. However, the effects of vaportight rigid foam insulation on the drying capability of the wall systems are not fully understood. In this study, temperature and moisture conditions in north-facing and south-facing wall assemblie...

The importance of lignin as a recalcitrant constituent of soil organic matter (SOM) remains contested. Associations with iron (Fe) oxides have been proposed to specifically protect lignin from decomposition, but impacts of Fe-lignin interactions on mineralization rates remain unclear. Oxygen (O2) fluctuations characteristic of humid tropical soils drive reductive Fe dissolution and precipitation, facilitating multiple types of Fe-lignin interactions that could variably decompose or protect lignin. We tested impacts of Fe addition on 13C methoxyl-labeled lignin mineralization in soils that...

Acoustic tomography for urban tree inspection typically uses stress wave data to reconstruct tomographic images for the trunk cross section using interpolation algorithm. This traditional technique does not take into account the stress wave velocity patterns along tree height. In this study, we proposed an analytical model for the wave velocity in the longitudinal–radial (LR) plane of a live tree. Both field and laboratory stress wave testing were conducted to determine the stress wave velocity patterns in healthy and defective trees. The results showed that the ratio of the wave velocity...

This paper describes the testing plan and current progress for assessing the efficacy of using ground-penetrating radar (GPR) to detect fungal decay within Douglas-fir beams. Initially, the beams were assessed using a variety of physical, mechanical, and nondestructive evaluation (NDE) test methods including micro-resistance drilling, Janka hardness, ultrasonic transmission, and GPR. After initial baseline assessment, beams were inoculated with brown rot fungus, Fomitopsis pinicola, and exposed to above-ground conditions approximately 25 miles (40 km) north of Gulfport, Mississippi, USA....

This paper examines the accuracy of a recently developed hygrothermal-corrosion model which predictsthe corrosion of fasteners embedded in wood by comparing the results of the model to a one year fieldtest. Steel and galvanized steel fasteners were embedded into untreated and preservative treated woodand exposed outdoors while weather data were collected. Qualitatively, the distribution of corrosionproducts along the length of the fastener were in agreement with the simulation results. Quantitatively,the combined hygrothermal-corrosion model predicted 20% less corrosion than measured in...

The objective of this study was to examine the potential of ultrasonic velocity as a rapid and nondestructive method to predict the dimensional stability of oak (Quercus petraea (Mattuschka) Lieblein) and chestnut (Castanea sativa Mill.) that are commonly used in flooring industry. Ultrasonic velocity, specific gravity, and radial, tangential and volumetric shrinkages were measured on seventy-four 20
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30-mm3 specimens obtained from freshly cut oak and chestnut stems. The ultrasonic velocities of the specimens decreased with increasing moisture content (MC). We found that specific...

In this study, the interfacial and mechanical properties of cellulose nanocrystals (CNC) coated glass fiber/epoxy composites were investigated as a function of the CNC content on the surface of glass fibers (GF). Chopped GF rovings were coated with CNC by immersing the GF in CNC (0–5 wt%) aqueous suspensions. Single fiber fragmentation (SFF) tests showed that the interfacial shear strength (IFSS) increased by ~69% in composites produced with CNC coated GF as compared to uncoated GF, suggesting an enhancement of stress transfer across the GF/matrix interface. The role of CNC coatings on the...

All consumer products have an environmental footprint. Quantifying that footprint has become more common with the advent of Environmental Preferential Purchasing (EPP), an emergent world-wide phenomenon. The forest products industry in particular has been challenged regarding its environmental sustainability. The greatest challenges with respect to practices center on the extraction of forest resources with questions about product environmental performance focused on uses, longevity and final disposal. In addition forest land owners and product manufacturers are facing increased environment...

Wood material surface properties play an important role in adhesive bond formation and performance. In the present study, a test method was developed to evaluate the integrity of the wood surface, and the results were used to understand bond performance. Materials used were rotary cut birch (Betula pendula Roth) veneers, produced from logs soaked at 20 or 70 °C prior to peeling and followed by drying at 160 °C. Surface quality was evaluated through surface roughness measurement, SEM imaging, lathe check depth evaluation and surface integrity testing. The results show that soaking logs at...

This report presents annual data but is published every 2 years. The data present current and historical information on production, trade, consumption, and prices of timber products in the United States. The report focuses on national statistics but includes some data for individual states and regions and for Canada. The data were collected from industry trade associations and government agencies. They are intended for use by forest land managers, forest industries, trade associations, forestry schools, renewable resource organizations, individuals in the major timber producing and...