Treesearch

This report summarizes technical and scientific literature on the relationship between silvicultural practices and engineering properties of wood from northern hardwood species grown in the Great Lakes Region. Knowledge of engineering properties is critical to the utilization of hardwoods in engineered wood products, including but not limited to wood composites and mass timber. In addition, this review revealed the following: (a) fundamental property information from research studies conducted in the early 20th century exists for many hardwood species indigenous to the Great Lakes Region;...

This is a guide for the collection of reference s amples of trees to enable the identification of species and/or geographical origin of woody material.

Cellulose nanofibrils (CNF) are a promising building block of structural materials because they are biodegradable, can be made into optically transparent bulk materials, and have exceptional specific strength and stiffness compared to common synthetic polymers. The manufacturing of bulk materials from CNFs is a challenge because CNFs form networks in solution at low solids concentration, which can result in long processing times as well as large residual stresses and distortion upon water removal. Here, a method to form materials from CNF suspensions via direct ink writing, a type of...

Jadeite artefacts at Maya sites are normally associated with ritual and ceremonial loca-tions, with high-quality jadeite reserved for elite objects. The discovery of a jadeite gouge with a wooden handle at a Classic Maya salt-working site submerged by sea-level rise—Ek Way Nal, Belize—is therefore unexpected and provides new information about the utilitarian use of this stone. The extremely high quality of this jadeite tool is particularly surprising, offer-ing new insight into the Classic Maya exchange systems and the role of salt makers such as those based at Ek Way Nal.

The concentration of atmospheric carbon dioxide is constantly rising, with severe effects on global climate change. To mitigate impacts of climate change, the role of forest in terms of carbon sequestration are well-known as trees naturally pull CO2 from the atmosphere as they grow. Contrarily, only recently the carbon mitigation value of wood-based products in buildings has been recognized. Buildings are a fundamental sector for wood-based products, both in terms of volume and service life length. In particular, furnishings in housing include high quantities of wood-based products; they...

The pore size distribution of cell walls in softwood pulps was studied using the pressure plate technique and mercury intrusion porosimetry, which together make it possible to cover the range from 101 to 106 nm in pore sizes (mesopores and macropores). The differences in pore size distribution between never-dried pulp from a fiber line, industrially-dried pulp, and laboratory-dried pulps were evaluated. The results showed an increase in the relative pore volume (100 to 2,000 nm) between industrial washing and bleaching stages. Also, mercury porosimetry showed a broadening of the pore size...

Chemical modification of the hydroxyl groups of wood can improve the properties of wood by providing moisture and biological resistance, as well as dimensional stability. Southern pine solid wood was chemically modified to various weight percentage gains (WPG) with epoxybutene (EpB, 8%-38% WPG). After modification, specimens were extracted with a toluene: ethanol (2:1) solution for 2 hours or water leached for 2 weeks. The equilibrium moisture content (EMC) at 30%, 65% and 90% relative humidity (RH) and 27°C was determined on all specimens. Laboratory soil block decay evaluations against...

Utilization of cellulose nanofibril (CNF) material for light weight and high strength structural composites has attracted considerable attention in the recent years. CNF aerogels have a microporous structure that could have potential properties, such as ultra-low density, high porosity, high specific surface area, high flexibility, and low thermal conductivity. However, producing such a product is still somewhat problematic. In this study, an epoxy/CNF (EP/CNF) nanocomposite foam with micro-rib structures has been developed using emulsification combined with freeze-dried processes. The...

Lignin graphene oxide was oxidized after Kraft lignin was graphitized by thermal catalytic conversion. The reduced lignin graphene oxide was derived from lignin graphene oxide through thermal reduction treatment. These Kraft lignin, lignin graphite, lignin graphene oxide, and reduced lignin graphene oxide were characterized by scanning electron microscopy, raman microscopy, high-resolution transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, atomic force microscopy and thermogravimetric analysis. The results showed lignin graphite converted from...

Poplar wood was fractionated under a range of conditions using an inexpensive and recyclable commercial aromatic acid, p-toluenesulfonic acid (p-TsOH), as an acid hydrotrope (AH). The fractionated cellulose-rich solid fraction demonstrated excellent physical and optical properties as papermaking fibers. The dissolved xylose can be dehydrated into furfural using the p- TsOH in the spent liquor without additional catalysts. The acid hydrotrope dissolved lignin (AHL) has high β-aryl ether linkage content (∼60%) and high molecular weight (∼4000 Da), similar to that of mill wood lignin (MWL)....