Treesearch

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....

Soils are significant terrestrial carbon stores yet the mechanisms that stabilize organic carbon in mineral soil remain poorly constrained. Here, we identified climate and topographic controls on soil organic carbon storage along the Catalina Critical Zone Observatory that spans a significant range in mean annual temperature (>10 °C) and mean annual precipitation (>50 cm year-1). Granitic soils were collected from divergent summit and convergent footslope positions in desert scrub, pine, and mixed conifer systems. Physical soil carbon distribution was quantified using a density and...

Traditional models of decomposition fail to capture litter mass loss patterns in dryland systems. This shortcoming has stimulated research into alternative drivers of decomposition, including photodegradation. Here, we use aboveground litter decomposition data for dryland (arid) sites from the Long-term Intersite Decomposition Experiment Team data set to test hypotheses (models) about the mechanisms and impacts of photodegradation. Incorporating photodegradation into a traditional biotic decomposition model substantially improved model predictions for mass loss at these dryland sites,...

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...

The ability of people to participate in the decisions that affect their lives is a tenet of democratic governance. In the broadest sense, public participation pertains to processes by which people engage in the development and implementation of public policies and programs. Fung (2006) stated that participation serves the democratic values of legitimacy and justice and improves the effectiveness of public action. Public participation can be carried out in a variety of ways, from casting votes at the ballot box, to testifying in court, to demonstrations and protests. It is also accomplished...

The effects of temperature and copper catalyst concentration on the formation of graphene-encapsulated copper nanoparticles (GECNs) were investigated by means of X-ray diffraction, Fourier transform infrared spectroscopy-attenuated total reflectance, and transmission electron microscopy. Results showed that higher amounts of copper atoms facilitated the growth of more graphene islands and formed smaller size GECNs. A copper catalyst facilitated the decomposition of lignin at the lowest temperature studied (600°C). Increasing the temperature up to 1000°C retarded the degradation process,...

This report describes the testing plan and preliminary results in an ongoing project to assess the efficacy of using ground-penetrating radar (GPR) to detect internal moisture and fungal decay within Douglas-fir beams. Initially, the test beams were assessed using a variety of physical, mechanical, and nondestructive evaluation (NDE) test methods including micro-resistance drilling, Janka hardness, stress wave transmission, and GPR. After initial baseline assessment, test beams were inoculated with brown-rot fungus, Fomitopsis pinicola, and exposed to just above-ground conditions 22 miles...

Winter is typically considered a dormant period in northern forests, but important ecological processes continue during this season in these ecosystems. At the Hubbard Brook Experimental Forest, located in the White Mountains of New Hampshire, we used an elevational climate gradient to investigate how changes in winter climate affect the litter and soil invertebrate community and related decomposition rates of Acer saccharum (Sugar Maple) litter over a 2-year period. The overall abundance and richness of litter invertebrates declined with increasing elevation, while the diversity and...