Treesearch

Two simple methods based on the 370 cm-1 Raman band intensity were developed for estimation of syringyl-to-guaiacyl (S/G) ratio in woods. The methods, in principle, are representative of the whole cell wall lignin and not just the portion of lignin that gets cleaved to release monomers, for example, during certain S/G chemical analyses. As such, it is like the whole-cell-wall NMR methods. The Raman analysis is quick, free of the use of harmful chemicals, carried out nondestructively, and is insensitive to the wet or dry state of the sample. The only limitation is that a wood sample should...

The weathering performance of wood coated with a combination of rutile TiO2 hierarchicalnanostructures and a sol-gel deposit of alkoxysilanes was determined by exposing three sets of specimens to UV light and water spray. The first set consisted of specimens coated with a mixture of methyltrimethoxysilane (MTMOS) and hexadecyltrimethoxysilane (HDTMOS). The second set consisted of specimens coated with nanostructural TiO2 followed by a mixture of MTMOS and HDTMOS. The third set consisted of uncoated control specimens. The wood coated with TiO2 followed by a mixture of MTDMOS and HDTMOS...

An equivalent strain method was used to analyze and determine material relaxation properties for specimens from particleboard, high density fiberboard, and medium density fiberboard. Cantilever beams were clamped and then deflected to 11 m and held for either 2 h or 3 h, while the load to maintain that deflection was measured vs. time. Plots of load relaxation for each specimen showed similar load relaxation vs. time even though there were some slight differences in the maximum load per sample. Three models were developed to fit the relaxation data. The first model was a simple log...

The industrial production of palm oil concurrently generates a substantial amount of empty fruit bunch (EFB) fibers that could be used as a feedstock in a lignocellulose based biorefinery. Lignin byproducts generated by this process may offer opportunities for the isolation of value-added products, such as p-hydroxybenzoate (pBz), to help offset operating costs. Analysis of the EFB lignin by nuclear magnetic resonance (NMR) spectroscopy clearly revealed the presence of bound acetate and pBz, with saponification revealing that 1.1 wt% of the EFB was pBz; with a lignin content of 22.7 %, 4.8...

Protecting wood products from biodeterioration has been a dynamic area of research in the past decade with an emphasis on the development of non-arsenical wood preservatives. Naturally occurring cellulose nanomaterials that are reported to have unique chemical properties, high strength, and stiffness were evaluated for the potential to improve durability of wood either as a stand-alone treatment or in combination with a cationic biocide. In this study, benzalkonium chloride (ADBAC) was selected as a biocidal counter-cation for the sulfate ester on cellulose nanocrystals (CNC). In a...

Molecular dynamics simulation is commonly used to study the properties of nanocellulose-based materials at the atomic scale. It is well known that the accuracy of these simulations strongly depends on the force field that describes energetic interactions. However, since there is no force field developed specifically for cellulose, researchers utilize models parameterized for other materials. In this work, we evaluate three reactive force field (ReaxFF) parameter sets and compare them with two commonly-used non-reactive force fields (COMPASS and GLYCAM) in terms of their ability to predict...

Species identification of logs, planks, and veneers is difficult because they lack the traditional descriptors such as leaves and flowers. An additional challenge is that many transnational shipments have unreliable geographic provenance. Therefore, frequently the lowest taxonomic determination is genus, which allows unscrupulous importers to evade the endangered species laws. In this study we explore whether analysis of wood using a Direct Analysis in Real Time (DART) Time-Of-Flight Mass Spectrometer (TOFMS) can assist in making unequivocal species determinations of Dalbergia. DART TOFMS...

Four species of the ectomycorrhizal (ECM) genus Sarcodon (Bankeraceae, Thelephorales, Basidiomycota) are described as new to science. Sarcodon pakaraimensis sp. nov. is described from forests dominated by the ECM trees Pakaraimaea dipterocarpacea (Dipterocarpaceae) and Dicymbe jenmanii (Fabaceae subfam. Caesalpinioideae) in the Pakaraima Mountains of Guyana. Sarcodon portoricensis sp. nov. is described from lower montane wet forest within the El Yunque National Forest of Puerto Rico. Sarcodon quercophilus sp. nov. and Sarcodon umbilicatus sp. nov. are described from Quercus (Fagaceae)...

In this study, cellulose nanocrystals (CNCs) are incorporated into a waterborne epoxy resin following two processing protocols that vary by order of addition. The processing protocols produce different levels of CNC dispersion in the resulting composites. The more homogeneously dispersed composite has a higher storage modulus and work of fracture at temperatures less than the glass transition temperature. Some properties related to the component interactions, such as thermal degradation and moisture content, are similar for both composite systems. The mechanism of dispersion is probed with...

Eight poorly known or unusual crustose and pileate basidiomycete species were studied. These included the type specimens of three monotypic genera: Chrysoderma alboluteum from Réunion is conspecific with Cerocorticium molle; Dendrophysellum amurense from the Russian Far East is a species of Vararia; and Hyphoradulum conspicuum belongs in Pseudolagarobasidium and is the first representative of the genus from Europe. Corticium murrillii, from Mexico, is congeneric with Corneromyces kinabalui. New combinations Vararia amurensis, Pseudolagarobasidium conspicuum, and Corneromyces murrillii are...