Treesearch

Wildland fire can cause significant damage but is also a natural process that is key to the healthy functioning of many ecosystems worldwide. Primary fuels for a wildland fire are the dead foliage and small branches which accumulate as litter on the ground. A cone calorimeter was used to measure the various aspects of these fuels. A single sample of preignition gases from the live leaves of seven plant species were vacuum collected on quality filters and within super-chilled solvent mixtures. GC-TOFMS (1D) and GCxGC-TOFMS (2D) were used to characterize the "white" smoke emissions. The...

This report highlights the benefits of tropical research in wood durability, preservation, and related fields. The Forest Products Laboratory (FPL) has a long tradition of conducting tests in the tropics around the world and recognizes the benefits they present. Research needs are also discussed, and research partners are identified. The appendixes summarize activities during the 2019 research summit in Panama and Suriname in which FPL and Michigan Technological University (MTU) participated. In late 2017, Department of Defense (DOD) contacted FPL and MTU to assist in durability evaluations...

Cross-laminated timber (CLT) used in the U.S. is mainly imported from abroad. In the existing literature, however, there are data on domestic transportation, but little understanding exists about the environmental impacts from the CLT import. Most studies use travel distances to the site based on domestic supply origins. The new Adohi Hall building at the University of Arkansas campus, Fayetteville, AR, presents the opportunity to address the multimodal transportation with overseas origin, and to use real data gathered from transporters and manufacturers. The comparison targets the...

Field deployable computer vision wood identification systems can be relevant in combating illegal logging in the real world. This work used 764 xylarium specimens from 84 taxa to develop an image data set to train a classifier and identify 14 commercial Colombian timbers. We took images of specimens from various xylaria outside Colombia, trained and evaluated an initial identification model and then collected additional images from a Colombian xylarium (BOFw) and incorporated these images to refine and produce a final model. The specimen classification accuracy of this final model was ~...

Cellulose nanocrystals (CNCs) are crystalline nano-rods that have high specific strength with hydroxyl surface chemistry. A wide range of chemical modifications have been performed on the surface of CNCs to increase their potential to be used in applications where compatibilization with other materials is required. Understanding the surface chemistry of CNCs and critically examining the functionalization technique are crucial to enable control over the extent of modification and the properties of CNCs. This work aims to optimize the surface modification of wood-derived CNCs with isocyanatoe...

The Wisconsin Department of Transportation recognizes the importance of accurately assessing the timber deck slab bridge inventory within the state. Of the 571 timber bridges in Wisconsin, 450 bridges are timber slab bridges. Current methods of load rating employ equations first developed in the later 1980s and early 1990s for determining the equivalent strip width. These equations often produce results that unnecessarily penalize the bridge by requiring a posted weight limit. Through a program of bridge live load tests and analytical modeling, the researchers in this study have both...

Cellulose nanofibrils (CNFs) have already been proved to be a potential candidate as one of the next-generation renewable and sustainable packaging materials. However, the mechanical and barrier properties of CNF films are not yet up to the mark for certain applications, especially at higher relative humidity. Those properties can be controlled by the degree of fibrillation of fibers and drying methods of films. Here we prepared CNF films from CNF suspensions with two different degrees of fibrillation - standard CNF (90% fine) and high-fine CNF (97% fine) by casting and filtration. These...

This article describes a fast and reliable method of screening membrane materials designed by measuring moisture vapor transmission rate (WVTR) and permeance of membrane materials using a Payne-style diffusion cell (dry cup) placed in a Dynamic Vapor Sorption (DVS) instrument. The materials were cellulose nanocrystals (CNC)/polydimethylsiloxane (PDMS) hybrid membranes. A casting method was used to fabricate three types of membrane samples. The WVTR and permeance of the samples were measured at two RH (RH) levels of 60% and 80% at 25 C. The results revealed that the WVTR and permeance of...

Preparation of activated carbons from wood waste including northern hardwood pins-fines and wood dust was conducted and then compared through the following methods: physical pyrolysis and CO2 activation, vacuum pyrolysis and CO2 activation, CO2 gasification, and vacuum CO2 gasification processes. Experimental results show that chars and activated carbons with high surface area and pore volume are produced from wood waste through a vacuum CO2 pyrolysis/gasification process. The effects of operation variables of vacuum pyrolysis/gasification on the properties of chars and activated carbons...

Catalytic pathways to produce high carbon number compounds from benzyl phenyl ether require multiple steps to break the aryl etheric carbon–oxygen bonds; these steps are followed by energy-intensive processes to remove oxygen atoms and/or carbon–carbon coupling. Here, we show an upgrading strategy to transform benzyl phenyl ether into large phenolic (C12–C22) compounds by a one-step C–O breaking and C–C coupling catalyzed by metal triflates under a mild condition (100 °C and 1 bar). Hafnium triflate was the most selective for the desired products. In addition, we measured the effect of...