Treesearch

Zinc naphthenate (ZnN) has been widely used for dip treatment of Department of Defense wood packaging materials but is no longer available. Research was conducted to evaluate the preservative efficacy and corrosiveness of U.S. Environmental Protection Agency (EPA) registered alternatives to ZnN. Efficacy of “green” preservatives (defined here as not containing pesticides that require EPA registration) was also evaluated. Most of the EPA-registered preservatives provided decay and termite protection similar to or greater than that of ZnN. Four of the formulations provided protection...

It is common practice to assume that a two-parameter Weibull probability distribution is suitable for modeling lumber properties. Verrill and co-workers demonstrated theoretically and empirically that the modulus of rupture (MOR) distribution of visually graded or machine stress rated (MSR) lumber is not distributed as a Weibull. Instead, the tails of the MOR distribution are thinned via “pseudo-truncation.” The theoretically portion of Verrill’s argument was based on the assumption of a bivariate normal—Weibull (Gaussian—Weibull) MOE—MOR distribution for the full population of lumber (as...

Soil samples were collected from field sites in two AWPA (American Wood Protection Association) wood decay hazard zones in North America. Two field plots at each site were exposed to differing preservative chemistries via in-ground installations of treated wood stakes for approximately 50 years. The purpose of this study is to characterize soil fungal species and to determine if long term exposure to various wood preservatives impacts soil fungal community composition. Soil fungal communities were compared using amplicon-based DNA sequencing of the internal transcribed spacer 1 (ITS1)...

In investing in a new venture, companies aim to increase their competitiveness and generate value in scenarios where volatile markets, geopolitical instabilities, and disruptive technologies create uncertainty and risk. The biobased industry poses additional challenges as it competes in a mature, highly efficient market, dominated by petroleum-based companies, and faces signifi cant feedstock availability and variability constraints, limited technological data, and uncertain market conditions for newly developed products. Thus, decision-making strategies and processes for these investment...

This study was to explore the conversion of low-cost bio-residuals into high value-added cellulose nanocrystals. Two enzymatic hydrolyzed residuals (i.e., HRMMW and HRSPW) were collected from two different bio-ethanol producing processes—hydrolyzing medium-milled wood (MMW) and hydrolyzing acid sulfite pretreated wood (SPW), respectively. The results showed that both residuals contained over 20 wt % glucan with a crystallinity of about 30%, confirming the existence of cellulose in a well-organized structure in two bio-residuals. The cellulose nanocrystals (CNCs) were successfully extracted...

The Pigorini cemí is an icon of Caribbean colonial history, reflecting early trans-Atlantic crosscultural exchanges. Although well documented, the piece has received surprisingly little systematic study. We present the first structural analysis and radiocarbon dating of the sculpture (modelled at AD 1492–1524), and a brief discussion of the materials from which it is comprised. These include indigenous shell and European glass beads, newly identified feather and hair fibres, and the enigmatic rhinoceros-horn mask carved as a human face. We also address the sculpture’s hidden internal...

Currently, feedstock size effects on chemical pretreatment performance were not clear due to the complexity of the pretreatment process and multiple evaluation standards such as the sugar recovery in spent liquor or enzymatic digestibility. In this study, we evaluated the size effects by various ways: the sugar recovery and coproduct yields in spent liquor, the chemical and thermal properties, and enzymatic digestibility of the pretreated solids. Four initial particle sizes were employed and characterized with the geometric mean diameters, which were 10.40, 2.25, 1.49, and 0.84 mm. The...

tMechanical pretreatment is an effective process for chemical or biochemical conversion of woodybiomass. The deconstruction features of the wood cell wall play an important role in its chemical or bio-chemical processing. In this work, we evaluated the wood cell wall fracture in the early stage of mechanicalpretreatment process conducted with various initial moisture contents. Electronic microscopy (i.e., SEMand TEM) and confocal laser scanning microscopy (CLSM) were used to visualize the cellular structurechanges due to cell wall fractures.Results reveal that the enzymatic digestibility...

This study demonstrated the technical potential for the large-scale co-production of sugars, lignosulfonates, cellulose, and cellulose nanocrystals. Ball-milled woods with two particle sizes were prepared by ball milling for 80 min or 120 min (BMW80, BMW120) and then enzymatically hydrolyzed. 78.3% cellulose conversion of BMW120 was achieved, which was three times as high as the conversion of BMW80. The hydrolyzed residues (HRs) were neutrally sulfonated cooking. 57.72 g/L and 88.16 g/L lignosulfonate concentration, respectively, were harvested from HR80 and HR120, and 42.6 ± 0.5% lignin...

Depolymerizing lignin, the complex phenolic polymer fortifying plant cell walls, is an essential but challenging starting point for the lignocellulosics industries. The variety of ether– and carbon–carbon interunit linkages produced via radical coupling during lignification limit chemical and biological depolymerization efficiency. In an ancient fungus-cultivating termite system, we reveal unprecedentedly rapid lignin depolymerization and degradation by combining laboratory feeding experiments, lignocellulosic compositional measurements, electron microscopy, 2D-NMR, and thermochemolysis....