Treesearch

To ensure the safety of trees, two NDT (nondestructive testing) techniques, electric resistance tomography and stress wave tomography, were employed to quantitatively detect and characterize the internal decay of standing trees. Comparisons between those two techniques were done to make full use of the individual capability for decay detection.

A modern paradigm of soil organic matter proposes that persistent carbon (C) derives primarily from microbial residues interacting with minerals, challenging older ideas that lignin moieties contribute to soil C because of inherent recalcitrance. We proposed that aspects of these old and new paradigms can be partially reconciled by considering interactions between lignin decomposition products and redox-sensitive iron (Fe) minerals. An Fe-rich tropical soil (with C4 litter and either 13C-labeled or unlabeled lignin) was pretreated with different durations of anaerobiosis (0−12 days) and...

A simple and novel method, self-assembly of nanocellulose and nanochitin, was developed to produce high-efficiency and versatile biohybrid hydrogel (BHH) and aerogel (BHA) for water purification. The self-assembly process was driven by the electrostatic force between one-dimensional (1D) negatively charged TEMPO-oxidized cellulose nanofiber (TOCNF) and positively charged partly deacetylated chitin nanofiber (PDChNF). The self-assembly process was performed at room temperature and without adding any crosslinking agents throughout the process. This results in the threedimensional (3D) BHH...

There is an increasing attention to cellulose nanofibrils (CNFs) for food packaging applications due to their abundance, biodegradability, and low gas permeability. In this work, oxygen and water barrier performance is studied for bio-nanocomposite films formed by incorporation of two types of bentonite (PGN and PGV) at different loads (15, 30 and 45 wt%) into continuous CNF matrix. The resulting hybrid films were analyzed for their morphology, surface energy, mechanical strengths as well as water/oxygen barrier qualities. Both types of bentonite lowered the CNF degradation temperature and...

With most wood products being bonded with adhesives, it is important to understand failures. Although it is observed macroscopically, it originates microscopically.

Despite the importance of cell wall diffusion to nearly all aspects of wood utilization, diffusion mechanisms and the detailed effects of moisture remain poorly understood. In this perspective, we introduce and employ approaches established in polymer science to develop a phenomenological framework for understanding the effects of moisture on diffusion in unmodifed wood cell walls. The premise for applying this polymer-science-based approach to wood is that wood polymers (cellulose, hemicelluloses, and lignin) behave like typical solid polymers.Therefore, the movement of chemicals through...

Illegal logging and associated trade aggravate the over-exploitation of Swietenia species, of which S. macrophylla King, S. mahagoni (L.) Jacq, and S. humilis Zucc. have been listed in Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) Appendix II. Implementation of CITES necessitates the development of efficient forensic tools to identify wood species accurately, and ideally ones readily deployable in wood anatomy laboratories across the world. Herein, a method using quantitative wood anatomy data in combination with machine learning models to discrimin...

Thermally modifed wood is becoming commercially available in North America for use in outdoor applications. While there have been many studies on how thermal modifcation affects the dimensional stability, water vapor sorption, and biodeterioration of wood, little is known about whether thermally modifed wood is corrosive to metal fasteners and hangers used to hold these members in place. As thermally modifed wood is used in outdoor applications, it has the potential to become wet which may lead to corrosion of embedded fasteners. Here, we examine the corrosiveness of thermally modifed ash...

Wood is a versatile and sustainable building material but may be vulnerable to fungal decay and insect damage when used outdoors or otherwise subjected to moisture. Pressure treatment with wood preservatives is the most common method of protecting wood from biological deterioration. This publication summarizes characteristics of pressure-treating preservatives and provides guidance for selection of pressure-treated wood for specific applications. It also discusses construction practices, service life expectations, and environmental considerations. The intended audience for this publication...

Computer vision systems for wood identifcation have the potential to empower both producer and consumer countries to combat illegal logging if they can be deployed effectively in the feld. In this work, carried out as part of an active international partnership with the support of UNIDO, we constructed and curated a feld-relevant image data set to train a classifer for wood identifcation of 15 commercial Ghanaian woods using the XyloTron system. We tested model performance in the laboratory, and then collected real-world feld performance data across multiple sites using multiple XyloTron...