Treesearch

Ability to determine stresses in loaded, perforated cellulosic-manure composites from recorded temperature information was demonstrated. Being able to stress analyze such green materials addresses several societal issues. These include providing engineering members fabricated from materials that are suitable for developed and developing nations, relieving a troubling by-product of agricultural regions and reducing demands on our landfills. Most engineering applications of these materials necessitate knowing their structural integrity eg capability to evaluate stresses.

In this study, the effects of cellulose nanofibrils (CNFs) ratio, press program, particle size, and density on the vertical density profile (VDP) and internal bond (IB) strength of the wet-formed particleboard were investigated. Results revealed that the VDP was significantly influenced by the press program. Pressing using a constant pressure (CP) press program produced panels with flat-shaped profile. Panels made from a constant thickness (CT) press program produced U-shaped profile. The CNF ratio and density also influenced the VDP especially for the CT panels. As the CNF ratio increased,...

Programs aimed at developing clones of hybrid trees are commonly established in Brazil to meet the demands of various forest-based industries. These programs have continually improved the quality of eucalyptus wood, which has the potential to reduce deforestation by lowering demand for other high-value species. This is particularly true in the lumber market, but little is known about the resistance of eucalyptus wood to biodegradation. This study evaluated variation in natural resistance of seven Eucalyptus grandis x Eucalyptus urophylla hybrid clones to decay by four wood-rot fungi and...

Wet-formed particleboard bonded with cellulose nanofibrils (CNF) was prepared in this work. The effects of density, CNF addition ratio, pressing method, and particle size on the bending strength were evaluated. The results showed that density had the most important effect on the modulus of elasticity (MOE), while the CNF addition ratio had the most important effect on the modulus of rupture (MOR). For panels with low density (< 640 kg/m3), the MOE and MOR did not change much with the configuration changes between particle size and pressing method. This was due to the synergistic effect of...

A comparative study was done on Liquidambar Orientalis Mill heartwood extractive samples. These extractives were collected from wood decay specimens. The objective of the study was to determine the chemical composition of the extractives remaining after exposure to brown rot fungi Tyromyces Palustris and white rot fungi Trametes Vericolor. All samples were extracted according to TAPPI Standard T-204. Samples were put through two different solvent systems and characterized by analytical techniques for any changes in chemical and morphological properties. The extracted chemicals collected...

We report the discovery of the hydrotropic properties of a recyclable aromatic acid, p-toluenesulfonic acid (p-TsOH), for potentially low-cost and efficient fractionation of wood through rapid and near-complete dissolution of lignin. Approximately 90% of poplar wood (NE222) lignin can be dissolved at 80°C in 20 min. Equivalent delignification using known hydrotropes, such as aromatic salts, can be achieved only at 150°C or higher for more than 10 hours or at 150°C for 2 hours with alkaline pulping. p-TsOH fractionated wood into two fractions: (i) a primarily cellulose-rich water-insoluble...

Identification of spatially varying stiffness is a challenging, but important, research topic in the mechanics of materials and can provide the necessary information for material suitability, damage, and process control, especially for high‐value applications. One homogeneous and 3 heterogeneous virtual field method (VFM) formulations were used to create a methodology for varying stiffness identification. Two finite element method simulations were used to demonstrate the validity and capability of the formulations. A tensile test protocol was implemented to identify spatially varying...

Wood-plastic composites (WPCs) have slower moisture sorption than solid wood, but over time moisture can impact the strength, stiffness, and decay of the composite. These changes will become increasingly important if WPCs are used in more challenging environments such as in ground-contact applications. There are several options for mitigating the moisture sorption of WPCs. A coupling agent can be added to potentially improve the wetting and dispersion of the wood flour and improve its adhesion with the plastic matrix. In previous investigations, the use of a coupling agent has been shown...

Imagine if you could measure all the genes being expressed at any one time in an organism and you knew what all the genes did in a cell. The power of this knowledge would allow you to determine how organisms regulate gene activity to survive. This is the essence of how “omics” science accelerates biological understanding. From a wood protections standpoint, understanding which genes regulate copper tolerance effectively identifies metabolic chokepoints that would have the highest likelihood of interfering with copper tolerance. Thus, the search for copper co-biocides is no longer random,...

The termite hindgut contains a bacterial community that symbiotically aids in digestion of cellulosic materials. For this paper, a species survey of bacterial hindgut symbionts in termites collected from Saucier, Mississippi was examined. Two methods were tested for optimal genetic material isolation. Genomic DNA was isolated from the hindgut luminal contents of five termites and 16S ribosomal RNA (rRNA) gene fragments were amplified with 16S rRNA amplicon primers. The fragments were cloned into E. coli cells and plasmid DNA was isolated from subsequent clones for sequencing. The results...