Treesearch

The aim of this study was to discern the film formation mechanism of cellulose nanoparticle suspensions (CNP suspensions) by transforming the film formation process to be a water evaporation process, investigating the fast freeze-drying morphology of CNPs, the resulting natural formation structure, and the relationship of CNPs and water molecules. It was found that an increasing aspect ratio transforms CNPs from the oriented arrangement to a distributed network. Hydrogen bonds and van der Waals forces among CNPs led to a close and interactive film formation process, contributing to various...

This study has evaluated the comminution energy reduction efficiency of a multi-stage milling method and established a mathematical mode for estimating the specifc energy consumption as a function of moisture content and particle size change. A Bliss hammer mill was employed to grind the feedstock targeting at two fna screen sizes of 0.84 and 0.69 mm. For the target screen size of 0.84 mm, the single-stage, two-stage, and threestage milling process were employed. Whereas, the single-stage, two-stage, and four-stage milling process were employed for the 0.69-mm target screen size. Four...

Cellulose nanomaterials (CNMs) are a unique type of nanomaterial that are produced via several routes including chemical and mechanical, including the most researched cellulose nanocrystals (CNCs) and cellulose nanofibrils (CNFs). CNM films exhibit excellent oxygen barrier properties in medium to low relative humidity conditions. The oxygen barrier characteristics are desirable for CNM film proposed use in food packaging applications where both performance and biodegradability are of concern. However, the oxygen barrier property of CNM films is reduced if films are exposed to high relative...

Conceptually, drought is a water shortage due to reduced rainfall compared to long-term, normal baseline conditions specific to geographical extents with ecological, social, and economic consequences. Objective and operational definitions of drought depend on perspective. Meteorological definitions are based on temporary departures from climate averages as measured by metrics including the Standard Precipitation Index, which is based on low rainfall relative to average precipitation. Similarly, the Palmer Drought Severity Index approximates the long-term balance between precipitation and...

In contrast with current operational products of burned area, which are generally available one month after the fire, active fires are readily available, with potential application for early evaluation of approximate fire perimeters to support fire management decision making in near real time. While previous coarse-scale studies have focused on relating the number of active fires to a burned area, some local-scale studies have proposed the spatial aggregation of active fires to directly obtain early estimate perimeters from active fires. Nevertheless, further analysis of this latter...

Forests are increasingly affected by natural disturbances. Subsequent salvage logging, a widespread management practice conducted predominantly to recover economic capital, produces further disturbance and impacts biodiversity worldwide. Hence, naturally disturbed forests are among the most threatened habitats in the world, with consequences for their associated biodiversity. However, there are no evidence-based benchmarks for the proportion of area of naturally disturbed forests to be excluded from salvage logging to conserve biodiversity. We apply a mixed rarefaction/extrapolation...

Mountains are model systems for understanding the mechanisms that underlie patterns of biodiversity and ecosystem function. This study disentangles the effects of climatic and edaphic properties on patterns of trait variation across two mountains, tests foundational assumptions of trait-based approaches, and tests the stress dominance hypothesis of decreasing trait variation with increasing environmental stress. The results suggest that elevation as a proxy of abiotic conditions is not enough to generalize the variability of plant strategies across mountains. The ability to distinguish...

A biomass biorefinery strategy for the selective fractionation of poplar into its three main compositions (hemicellulose sugars, lignin, and high-purity cellulose) with a two-step process is developed. The first step consists of the selective hydrolysis of hemicellulose at mild conditions in a CO2/H2O system. This leads to various hemicellulose sugars and other intermediates in the water-soluble fraction, with more than 87.90% of the hemicellulose being extracted from the original poplar (180 °C, 2.0 MPa CO2, 10 min). The pretreated sample is subsequently used for extracting lignin in a...

The invasion by emerald ash borer (Agrilus planipennis) of extensive black ash wetlands in the upper Great Lakes region of North America is expected to alter plant community structure and composition and, therefore, abiotic factors like temperature and hydrology.We conducted two experiments to examine how changes in leaf litter could alter ecosystem function via 1) changes in litter breakdown and 2) aquatic invertebrate feeding. For the first experiment, we placed litter bags containing black ash (Fraxinus nigra), swamp white oak (Quercus bicolor), and lake sedge (Carex lacustris), in...

Storms are among the greatest natural disturbances in temperate forests, and increased nitrogen (N) availability is thought to increase storm damage. However, the extent to which N availability increases damage from snowfall is less clear. To test how N availability might affect the susceptibility of trees to snow damage in a temperate forest, we took advantage of an opportunistic storm and surveyed damage in fertilized and unfertilized stands, and across a native N availability gradient. In response to a severe, early season snow storm—a consequence of Superstorm Sandy—the percentages of...