Treesearch

Wood densification, aimed at enhancing mechanical properties through compression, faces challenges due to set-recovery, where densified wood regains its original shape upon re-moistening. However, understanding the role of lignin in set-recovery remains elusive. In this study, acidified sodium chlorite was applied to achieve approximately 50 % delignification without removing other wood components from 3.2 mm veneers of birch, aspen, and grey alder. The veneers were then densified at 100◦C and 6 MPa, with wood moisture contents (MC) of 10 % and 16 %. The morphology, physical properties,...

Wood–plastic composites are composite materials consisting of wood particles, thermoplastic polymer, and small amounts of other performance additives to increase performance in exterior construction applications such as decking and siding. Three best-performing fire retardants, determined from a previous study, which were brominated, magnesium hydroxide, and ammonium polyphosphate, were selected for this weathering study and more detailed analysis with color analysis, thermogravimetric analysis/differential scanning calorimetry, and the cone calorimeter. With the rapid surface heating...

End coatings are typically used to help prevent end checks on sawn lumber during the drying process. These drying defects can cause a loss of valuable lumber. This study was conducted to look at the effectiveness of three different types of end coatings. After 1 year of air-drying, boards with each of the three end coatings were compared with each other, and they were also compared with untreated control boards. Although all three end coatings were found to be effective in decreasing the amount and severity of drying defects compared with the untreated controls, there were no significant...

Two of the most important characteristics of wood, its combustibility and strength, have made it so that wood has served humankind both as fuel and as a building material for thousands of years. As a building material, wood is often used for structures, transportation networks, and infrastructure systems. Wood materials come in many forms, including dimensional lumber, heavy timber, and engineered wood products (e.g., plywood, orientated strand board, glulam, and cross-laminated timber). A more recent category of engineered wood products, known as mass timber, has increased the market and...

The Log Recovery Analysis Tool (LORCAT) is a simulation tool that allows users to examine the impact of changes in the hardwood log-sawing process on sawn volume, grade recovery, and profit. LORCAT was designed to be simple to use and requires a minimum of user data entry. While the results of LORCAT have been informally compared to sawmill results by users, no formal validation of results has yet been performed. This study compared LORCAT’s simulated recovery results to that of an actual sawmill. For the 42 hardwood log samples we examined, we found no significant statistical difference...

This paper summarizes work conducted to assess the condition of members in historically significant timber sailing vessels. Four ship assessments are described, the USS Constitution, the USS Cairo, and the Wapama. Launched in 1797, the USS Constitution was nicknamed “Old Ironsides” and was a combat vessal used by the US Navy. “Old Ironsides” is a three-masted heavy frigate with a hull primarily constructed of live oak. The USS Cairo is a city class ironclad river gunboat. It was built in 1861 and commissioned in January 1862. It was used in combat by Union forces during the American Civil...

Background: Boreal forests cover vast areas of land in the northern hemisphere and store large amounts of carbon (C) both aboveground and belowground. Wildfires, which are a primary ecosystem disturbance of boreal forests, affect soil C via combustion and transformation of organic matter during the fire itself and via changes in plant growth and microbial activity post-fire. Wildfire regimes in many areas of the boreal forests of North America are shifting towards more frequent and severe fires driven by changing climate. As wildfire regimes shift and the effects of fire on belowground...

Cellulose nanomaterials (CNMs) have potential utilization as oxygen barrier layers when applied as the primary component of a single layer in multilayer packaging systems. One limitation of dense CNM films is their lack of durability due to their brittle nature. The durability of cellulose nanofibril (CNF) films was examined through the lens of understanding the residual stress that formed within the films during drying. A beam bending method consisting of drying CNF films on top of a flexible substrate was used to quantify residual stress. It was determined that for two common variations...

Engineered wood floor framing members, such as I-joists, must pass full-scale fire endurance tests to demonstrate equivalency to unprotected nominal 2 by 10 dimension lumber (actual dimensions 38 by 235 mm (1.5 by 9.25 in.)) if used in fire-rated assemblies. The full-scale test is performed in a furnace with dimensions of at least 3.7 by 3.7 m (12.1 by 12.1 ft) with a floor assembly loaded to 50% of the allowable stress design bending load. The standard fire curve is used during the test. The acceptance criteria of 15.5 min was determined from equivalence to the calculated fire resistance...

Elderberry (Sambucus spp.) is an emerging and popular specialty crop in North America and worldwide. Both the fruit and flowers are being increasingly consumed because of their proven health benefits, mostly in the form of dietary supplement products. We explored changes in consumer knowledge and purchasing preferences regarding elderberry products after comparing results of a survey conducted in 2022 with those of a previous study conducted in 2011. Findings based on responses from 1036 US residents revealed that 41.2% had previously consumed elderberry products. This marks a significant...