Treesearch

This paper reports on the ground-contact durability of lesser-used wood species of the northeastern United States after treatment with copper-based preservatives. Stakes (19 x 19 x 457 mm) cut from balsam-fir (Abies balsamea), eastern hemlock (Tsuga canadensis), eastern spruce (mixture of Picea glauca, Picea mariana and Picea rubens), red maple (Acer rubrum) or eastern white pine (Pinus strobus) were treated with one of four concentrations of chromated copper arsenate type C (CCA-C), copper citrate (CC), alkaline copper quat type C (ACQ-C) or copper azole type A (CBA-A) and placed into the...

Impact of planetary ball milling on pre-milled wood fiber was studied to improve efficiency of energy consumption for bioconversion using post-harvest forest residuals. Crystalline cellulose decreased from 40.73% to 11.70% by ball milling. Crystallinity index of ball milled wood samples had a negative correlation with glucose yield (r=−0.97, p < .01), xylose/mannose (r=−0.96, p < .01), and a positive correlation with median particle size (r=0.77, p < .01). Range of glucose yield and xylose/mannose yield for ball milled samples was found to be 24.45–59.67% and from 11.92% to 23.82%,...

To accelerate development of new and improved wood adhesives for engineered wood products, the optimal adhesive penetration into wood needs to be better understood for specific products and applications. Adhesive penetration includes both flow of adhesives into wood micron-scale voids and infiltration into the polymer components of the wood cell wall layers. In this work, X-ray computed tomography (XCT) and X-ray fluorescence microscopy (XFM) were used to study adhesive flow and infiltration. Model wood–adhesive bondlines were made using loblolly pine(Pinus taeda)latewood substrates and...

The use of mass timber structural products in tall building applications (6–20 stories) is becoming more common around the world including North America. A potential concern is the environmental wetting of mass timber products during construction because such products may dry out more slowly than light-frame structural lumber, and wood, as an organic material, is susceptible to deterioration at elevated moisture contents. In order to better understand the moisture conditions present in high rise timber constructions, a long-term moisture monitoring program was implemented on an eight...

A solvent-free route was developed to fabricate 100% biobased, renewable, and degradable polylactide (PLA) composites reinforced will ball-milled celluloses. The results show that the original pulp cellulose fibers were modified to partial amorphization through 30-min ball milling. Filling the ball-milled celluloses into PLA increased the tensile modulus for the resultant cellulose/PLA composite materials, while decreased their tensile strength and impact resistance. This method can be used to access the cost-efficient PLA-based composite materials with tunable mechanical properties. The...

This paper is a written summary of the keynote lecture presented at the 13th Annual Meeting of the Northern European Network on Wood Science and Engineering (WSE2017). The lecture summarized work performed at the Forest Products Laboratory (Madison, WI, USA) over the past 10 years related to understanding diffusion through cell walls. The highlighted work includes advances in electrical measurements and synchrotron-based X-ray fluorescence microscopy. The paper also discusses how diffusion is related to many wood damage mechanisms. The ultimate goal of the presented research is to develop...

Bridge inspection using a drone, also referred to as an unpiloted aircraft system, has gained more interest in recent years among bridge owners, researchers, and stakeholders because of its efficiency and effectiveness. In fact, numerous bridges classified as structurally deficient in the United States that require more attention and effort for maintenance activities can be inspected using drones in an efficient manner. The primary goal of this project was to evaluate drones as supplemental bridge inspection tools for bridges that present accessibility challenges for inspectors. To...

Lignin is a heterogenous plant cell wall polyphenol derived primarily from hydroxycinnamyl alcohols via combinatorial radical coupling reactions containing ether- and C-C linkages [2]. Its depolymerization is challenging, making lignin a major barrier to gaining access to stored energy within lignocellulosic materials [3]. Termites from the sub family Macrotermitinae form a monophyletic group of species that have cultivated fungi (Termitomyces spp.) using wood materials and are able to decompose lignocellulose almost completely [4]. Fungus-cultivating termites have evolved in mutualistic...

Dynamic vapor sorption (DVS) measurements are widely used to collect water vapor sorption isotherms for wood and other cellulosic materials. Equilibrium moisture content (EMC) is typically assumed to have been reached when the rate of change in moisture content with time (dM∕dt) drops below a certain value. However, the errors associated with determining EMC in this manner have never been characterized. Here, an operational defnition of equilibrium for DVS measurements is provided, and twenty test cases over four cellulosic materials are presented where the relative humidity was stepped up...

A post-esterifcation with a high degree of substitution (hDS) mechanical treatment (Pe(hDS)M) approach was used for the production of highly hydrophobic cellulose nanoparticles (CNPs). The process has the advantages of substantially reducing the mechanical energy input for the production of CNPs and avoiding CNP aggregation through drying or solvent exchange. A conventional esterifcation reaction was carried out using a mixture of acetic anhydride, acetic acid, and concentrated sulfuric acid, but at temperatures of 60–85 ◦C. The successful hDS esterifcation of bleached eucalyptus kraft...