Treesearch

Colonization of wood blocks by brown and white rot fungi rapidly resulted in detectable wood oxidation, as shown by a reduced phloroglucinol response, a loss of autofluorescence, and acridine orange (AO) staining. This last approach is shown to provide a novel method for identifying wood oxidation. When lignin was mildly oxidized, the association between AO and lignin was reduced such that stained wood sections emitted less green light during fluorescence microscopy. This change was detectable after less than a week, an interval that past work has shown to be too short for significant...

Lignins are complex and heterogeneous natural polymers in which the major units are characterized by certain prominent interunit linkages. Previous attempts to identify and quantify 4−O−5-linked units in softwood lignins by NMR were not successful. In this work, various lignin model compounds, including the tetramers formed by the 4−O−5- coupling of β−O−4-, β−β-, and β−5-model dimers, were synthesized. Such compounds are better able to model the corresponding structures in lignins than those used previously. 4−O−5-Linked structures could be clearly observed and identified in real softwood...

Background: Valorization of lignin from biofuel production is the key to developing biorefinery technologies for sustainable and economic utilization of lignocellulosic biomass. Here we present isolating lignosulfonate from the spent liquors of Sulfite Pretreatment to Overcome the Recalcitrance of Lignocelluloses (SPORL)-pretreated lodgepole pine and Douglas-fir forest residue as a dispersant for coal water slurry. The two SPORL pretreatments were conducted at a pilot scale and resulted in very high ethanol yield from the pretreated biomass. Therefore, demonstrating the commercial utility...

This paper examines how wood decay fungi affect the electrical resistance (resistivity) of wood to determine whether an electrical resistance probe could be deployed as a remote sensor in a wall to detect wood decay. Electrical resistance measurements were taken on wood blocks exposed to Gloeophyllum trabeum in a standard soil bottle tests (AWPA E10) as a function of time. To understand how and why resistance changed with time, results were compared against resistance measurements taken in sterilized, un-inoculated wood at high moisture contents; concentrations of certain mineral ions in...

Cross-laminated timber (CLT) is a relatively new heavy timber construction material (also referred to as massive timber) that origi-nated in central Europe and quickly spread to building applications around the world over the past two decades. Using dimension lumber (typically in the range of 1× or 2× sizes) glue laminated with each lamination layer oriented at 90° to the adjacent layer, CLT panels can be manufactured into virtually any size (with one dimension limited by the width of the press), precut and pre-grooved into desirable shapes, and then shipped to the construction site for...

This paper presents recent progress in the development of seismic performance factors for cross-laminated timber (CLT) systems in the United States. A brief overview of some of other systematic studies conducted in Europe, North America, and Japan is also provided. The FEMA P695 methodology is briefly described and selected results from connector testing and CLT wall testing are discussed. Shear and uplift tests were performed on generic angle brackets to quantify their behavior. CLT walls with these connectors were then tested investigate the influence of various parameters on wall...

The formation of graphene-encapsulated copper nanoparticles was investigated through carbonizing a mixture of kraft lignin and copper sulfate pentahydrate at the temperature up to 500 °C. The abrupt conversion of copper ions into its atoms occurred at 300 °C. The formation of graphene layers surrounding copper nanoparticles started as early as the heating temperature reached 400 °C. Most copper nanoparticles were covered with less than five graphene layers when the temperature reached 500 °C. The average diameter of graphene-encapsulated copper nanoparticles was 12.75 and 11.62 nm for...

To achieve green processing through recycling catalysts, this study demonstrated a commercial solid acid toluenesulfonic acid (p-TsOH) for furfural production from corncob. Acid recyclability study indicate that crystalized p-TsOH was highly effective for furfural production. A kinetic based reaction severity, combined hydrolysis factor (CHF), was used to develop a furfural predictive model with the consideration of loss through degradation. Furfural yield of approximately 75% theoretical was achieved in a CHF range between 830 and 1850.

This paper reports the implementation of renewable, biodegradable, and abundant cellulose nanofibrils (CNFs) in triboelectric nanogenerator (TENG) development. Flexible and transparent CNF thin films are triboelectric positive material with nanoscale surface roughness. They are paired with FEP (fluorinated ethylene propylene) to assemble TENG devices, which exhibit comparable performance to the reported TENG devices built on synthetic polymers. CNF-based TENG is further integrated within a fiberboard made from recycled cardboard fibers using a chemical-free cold pressing method. The...

tSuperhydrophobic and crosslinked poly(vinyl alcohol) (PVA)/cellulose nanofibril (CNF) aerogel micro-spheres were prepared via a combination of the water-in-oil (W/O) emulsification process with thefreeze-drying process, followed by thermal chemical vapor deposition of methyltrichlorosilane. The oilphase and the cooling agent were judiciously selected to ensure that the frozen ice microspheres canbe easily separated from the emulsion system. The silanized microspheres were highly porous with abulk density ranging from 4.66 to 16.54 mg/cm3. The effects of the solution pH, stirring rate, and...