Treesearch

Many durable wood species contain extractives with biologically active chemical components that have potential to be used for the development of pharmaceuticals. For this study, extractive compounds from western redcedar (Thuja plicata) were separated by their relative polarities using liquid–liquid fractionation and characterized through gas chromatography–mass spectroscopy (GC–MS). Fractionation was successful at separating the components of western redcedar in a consistent manner, and GC–MS was able to identify the presence of various terpenoid compounds, primarily nezukone and thujaplic...

Commonly the raw material round timber is reduced into smaller parts such as solid wood boards, sheets of veneer, strands, particles, and fibers for further manufacturing and processing. In following steps, the single wooden pieces are joined together by adhesive bonding to achieve the final structures such as various types of wood laminations or wood-based panels. This chapter describes the various mechanical connecting and adhesive bonding solutions. Different mechanical connector systems are introduced in theory and practice. A major part of the chapter is dedicated to wood adhesion and...

Glue laminated timber (glulam) is an engineered wood product composed of wood laminations bonded together with durable adhesives. Glulam is versatile ranging from simple, straight beams to complex, curved structural members and are used in a variety of applications including residential and commercial construction where they are often exposed due to the timeless aesthetic of wood. Glulam beams are also resource-efficient and offer designers highly predictable structural and fire performance when used in accordance with design specifications. However, factory-cut or field modifications to...

Timber structures decay over time with degradation in their structural integrity. Changing environmental conditions, varying loads, exposure to moisture or insect attacks lead to changes in their vibrational response behaviour. Here we present a low-cost device used as a triggered exciter to enable the monitoring of the structural integrity of timber bearers or even power poles in electricity networks. The actuation is initiated by a novel purpose-built, calibrated spring-loaded piezo-electric exciter. The device is connected to a fibre-optical network with optical accelerometers to...

Sulfurized polyacrylonitrile (SPAN) is a promising cathode active material capable of suppressing lithium polysulfide dissolution in lithium−sulfur (Li−S) batteries. However, due to the low S content in SPAN, achieving a high SPAN areal loading without compromising specific capacity and cycling stability would be required. To address this challenge, we took advantage of the inherent porous structure of natural wood and engineered carbonized delignifed wood (CDW) frameworks using a delignification/low-temperature pyrolysis approach. The unique design of the SPAN-impregnated CDW (SPAN@CDW)...

Candidate insecticide products under consideration for use as soil termiticides are required to have specific efficacy data for federal registration by the U.S. Environmental Protection Agency (EPA). Data that are collected annually by the U.S. Department of Agriculture (USDA) Forest Service (FS) Forest Products Laboratory (FPL), Durability and Wood Protection research work unit (RWU 4723), serve to fulfill this need. The FS group installs and evaluates wooden test pieces on plots of soil treated with candidate termiticide products. Data from these studies are used in the registration...

Currently, the North American standard, ANSI/APA PRG 320: Standard for Performance-Rated Cross-Laminated Timber, requires a full-scale compartment fire test to qualify adhesives for use in cross laminated timber (CLT) for structural applications. This test is necessary to determine whether the adhesives will experience heat delamination - a premature adhesive failure during fire that can lead to sudden fire regrowth during the decay phase of a fire commonly referred to as a secondary flashover. The required full-scale test is cost-prohibitive to adhesive manufacturers when developing new...

United States hardwood production and markets have seen a number of ups and downs over the last 20 years since peak production in the late 1990s, followed by historic lows during the "Great Recession" in 2009 and a slowly recovering industry since. During this time, we have seen the loss of domestic furniture and cabinet markets, increases in forest product export markets, trade disputes, reduced grade-lumber, and increased industrial wood demand, and most recently the COVID-19 crisis. With this backdrop, presenters from forest industry, wood market pricing services, and wood products...

Trees contain a number of different extractives that may have specific biological activities, many of which are capable of protecting the tree against different forms of infection. The hardwood species catalpa (Catalpa speciosa) is one of many types of wood that are rich with these chemicals. Researchers are often interested in extractives because knowledge of the defense mechanisms of trees against xenobiotics could potentially be applied to pharmaceutical development. For instance, literature indicates that catalpa wood often contains high concentrations of sterolic and phenolic compounds...

Casehardening is commonly misunderstood. This report should improve understanding of wood moisture issues, especially for the woodcrafters and woodworker.