Treesearch

Cellulose nanomaterials have attracted much attention in a broad range of fields such as flexible electronics, tissue engineering, and 3D printing for their excellent mechanical strength and intriguing optical properties. Economic, sustainable, and eco-friendly production of cellulose nanomaterials with high thermal stability, however, remains a tremendous challenge. Here versatile cellulose nanocrystals (DM-OA-CNCs) are prepared through fully recyclable oxalic acid (OA) hydrolysis along with disk-milling (DM) pretreatment of bleached kraft eucalyptus pulp. Compared with the commonly used...

This paper is the first stage of a study that attempts to improve the process of manufacturing treated lumber through the use of statistical process control (SPC). Analysis of industrial and auditing agency data sets revealed there are differences between the industry and agency probability density functions (pdf) for normalized retention data. Resampling of batches of treated wood without replacement appears to affect the pdf of the industrial data. The best-fitting pdf for the agency data is the Largest Extreme Value (LEV) pdf. Assumptions of a normal or a Gaussian pdf may not be valid....

Stake tests are a critical part of evaluating durability of wood in ground-contact, but there is a lack of criteria for interpreting stake test results. This paper discusses criteria that might be used to determine if short term ratings indicate satisfactory longterm performance. Ratings of 19 by 19 mm stakes from multiple plots in the Harrison Experimental Forest, Mississippi, were analyzed to determine how well performance criteria at years three, four, or five predicted durability over the longer term (nine years). Results revealed that with only three years of data, false prediction of...

This report summarizes a state-of-the-art review conducted on the topic of field measurement of the quality of wood in trees. The foundation science of micro-resistance drilling and acoustic-based techniques for use with woody materials is presented, and use of these techniques for the detection of biodeterioration in wood is discussed. Quantification of the physical and mechanical properties of wood, in standing timber, is reviewed. Studies designed to examine the use of these techniques with trees are summarized, and a list of commercially available technologies that use these techniques...

Thirteen bonded engineered wood products representing those commonly used in building construction were evaluated for volatile organic chemicals using methods developed for interior bonded wood products. Although formaldehyde and acetaldehyde were emitted from all samples, they were not the dominant volatiles, which greatly depended on wood species and bonding processes.

Limited long-term field data exist evaluating the benefit of chemical wood preservatives on refractory wood species with abundant heartwood. The objective of this study was to determine the effectiveness of preservative-treated refractory solid heartwood comprised of southern pine, Douglas-fir, or Engelmann spruce. Non-incised and incised solid lumber of these species were treated to three different retentions of either chromated copper arsenate (CCA) or ammoniacal copper arsenate (ACA) and placed in ground contact (AWPA E7) at a Mississippi field test site in 1975. Field stakes were rated...

Surfaces of novel foam core sandwich panels were adhered with intumescent fire‐retardant paper underneath the veneers (FRV) to improve their flammability properties. The panels were evaluated by means of cone calorimeter test (ASTM E 1354). Variables tested were different surface layer treatments, adhesives used for veneering, surface layer thicknesses, and processing conditions, having the objective of obtaining similar or better flammability as that of solid particle boards. Previous research showed that sandwich panels without FRV compared to panels with FRV generally had much higher...

Increasing environmental regulations have limited the use of certain broad spectrum synthetic pesticides as wood preservatives creating a need for more environmentally benign wood preservative systems. Biocidal compounds from natural products have been proposed as alternatives to commercial wood preservatives, but field data from long term performance testing is lacking. To investigate long term performance of wood extractives, stakes and blocks of southern pine (SP) and cottonwood (CW) were treated with heartwood extractives of four durable wood species commonly used in Pakistan. Treated...

Cementitious materials cover a very broad area of industries/products (buildings, streets and highways, water and waste management, and many others; see Fig. 20.1). Annual production of cements is on the order of 4 billion metric tons [2]. In general these industries want stronger, cheaper, more durable concrete, with faster setting times, faster rates of strength gain, and there is growing interest in advancing sustainability [3]. To achieve these improvements in properties, there are a wide range of additives such as supplementary cementitious materials (SCMs) [4], chemical admixtures...

Composition of the southern pine forest is now predominated by two species, loblolly pine (Pinus taeda L.) and slash pine (Pinus elliottii Engelm.), owing to fire suppression activities, natural regeneration on abandoned agricultural lands, and extensive planting. Comparison of the wood and bark physical properties of these pines is of interest in terms of the yields of usable biomass and, for the bark, its ecological functionality on a living tree. Trees from a species comparison study were used to generate wood and bark property data, on a whole-tree basis, and for stem disks collected...