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Endoxylanases are important enzymes in bioenergy research because they specifically hydrolyze xylan, the predominant polysaccharide in the hemicellulose fraction of lignocellulosic biomass. For effective biomass utilization, it is important to understand the mechanism of substrate recognition by these enzymes. Recent studies have shown that the substrate specificities of bacterial and fungal endoxylanases classified into glycoside hydrolase family 30 (GH30) were quite different. While the functional differences have been described, the mechanism of substrate recognition is still unknown....

The effect of fiber drying on the properties of lignin containing cellulose nanocrystals (LCNC) and nanofibrils (LCNF) produced using concentrated maleic acid hydrolysis of a never dried unbleached mixed hardwood kraft pulp was evaluated. Two drying conditions, i.e., air drying and heat drying at 105°C were employed. It was found that drying (both air and heat) enhanced acid hydrolysis to result in slightly improved LCNC yields and less entangled LCNF. This is perhaps due to the fact that drying modified the cellulose supermolecular structure to become more susceptible to acid hydrolysis...

This paper introduces a concentrated di-carboxylic acid (DCA) hydrolysis process for the integrated production of thermally stable and carboxylated cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). The DCA hydrolysis process addressed several issues associated with mineral acid hydrolysis for CNC production, such as cellulose loss and acid recovery. The surface and morphological properties of the cellulose nanomaterials resulting from the DCA hydrolysis process can be tailored simply by controlling the severity of DCA hydrolysis. To further reduce cost, a low temperature...

In this chapter, we present recent advances in the multi-scale data-driven inverse constitutive characterization of composites via multi-axial robotic testing, high-performance full-field strain measurement methods and surrogate models. Emphasis is given first on the motivating aspects for multi-scale model inversion for the case of laminated composites, followed by a description of a data-driven inverse constitutive characterization of the bulk lamina of composites via multi-axial loading of laminate-level coupons. A description of a surrogate modeling approach is presented in order to...

The formation of carbon-based nanomaterials was investigated through heating iron nitrate promoted kraft lignin at different temperatures up to 600°C under argon gas at atmospheric pressure. High-resolution transmission electron microscopy and electron diffraction images showed that multi-layer turbostratic-structured graphene presented in samples heated at 600°C. X-ray diffraction results indicated that iron oxides nanoparticles started their formation as an amorphous carbon matrix at 300°C, and turned into α-Fe nanoparticles at 600°C. It is believed that the formation of observed...

A free-standing, lightweight, highly porous, and highly flexible cellulose nanofibril (CNF)–reduced graphene oxide (RGO)–molybdenum oxynitride (MoOxNy) aerogel film electrode was synthesized by freeze-drying a CNF/GO/MoO3 aqueous dispersion followed by subsequent in situ hydrazine reduction. Due to the partial reduction and nitrogen doping of the MoO3 nanobelts and the highly open and continuous porous structure, the free-standing CNF/RGO/MoOxNy aerogel film electrode delivered an outstanding specific capacitance of 680 F g
1 in an aqueous electrolyte and 518 F g
1 in an ionic liquid...

Graphene-encapsulated copper nanoparticles (GECNs) can be applied in the wood protection industry. In this study, a simple thermal treatment was applied to a mixture of kraft lignin and copper sulfate for the synthesis of GECNs. The effect of temperature, duration time, temperature rising ramp, and argon gas flow rate were investigated on the quality of the GECNs. Temperature was found to be the most important factor in the growth of graphene; high temperature was preferred to obtain less defective graphene shells. Gas flow rate, duration time, and temperature rising ramp had less effect....

The objective of this research was to examine the technical feasibility of combining acoustic wave data with high-resolution laser scanning data to improve accuracy of hardwood log defect detection and segregation. Using acoustic impact testing and high-resolution laser scanning techniques, 21 yellowpoplar logs obtained from the central Appalachian region were evaluated for internal and external defects. These logs were then sawn into boards, and the boards were visually graded based on National Hardwood Lumber Association grading rules. The response signals of the logs from acoustic...

Cellulose, the most abundant natural polymer, is renewable, biodegradable, and cost competitive. This paper reports the development of a highperformance triboelectric nanogenerator (TENG) with both contacting materials made from cellulosic materials. Cellulose nanofibrils (CNFs) are used as the raw material, and chemical reaction approaches are employed to attach nitro groups and methyl groups to cellulose molecules to change the tribopolarities of CNF, which in turn significantly enhances the triboelectric output. Specifically, the nitro-CNF possesses a negative surface charge density of...

Increment core analysis has dominated research for more than half a century and has been used as a standard method for assessing basic wood density in forests, for determining biomass of ecosystems, and for investigating climate history through dendrochronological analysis. Comprehensive wood density models have been developed for commercially important species that use outer wood cores and knowledge of internal wood density distribution to fairly accurately predict the density of major tree components. With the development of SilviScan and near infrared spectroscopy instruments, more wood...