Treesearch

The interphase region of a wood-reinforced polypropylene (PP) composite was investigated with nanoindentation techniques capable of separating intrinsic properties of PP in the interphase region from the effect of elastic discontinuity caused by the nearby wood cell wall. From data collected in this experiment, no differences in hardness or Young’s modulus for PP were observed between bulk PP and PP in the inter-phase. Had the elastic discontinuity not been taken into consideration, the measured Young’s modulus would have appeared to increase in the interphase region. Observations were...

Although laboratory evaluations of wood-plastic composites (WPCs) are helpful in predicting long-term durability, field studies are needed to verify overall long-term durability. Field exposure can encompass numerous degradations i.e., fungal, ultraviolet light, moisture, wind, temperature, freeze/thaw, wet/ dry cycling, termites, mold, etc. that traditionally are studied separately in the laboratory. Moisture sorption of WPCs is slower than in unmodified solid wood, but it affects the strength, stiffness, and ultimately the decay of the material. The objectives of this study were to: 1)...

Progress in four interrelated catalysis research efforts in our laboratory are summarized: (1) catalytic photochemical functionalization of unactivated CeH bonds by polyoxometalates (POMs); (2) self-repairing catalysts; (3) catalysts for air-based oxidations under ambient conditions; and (4) terminal oxo complexes of the late-transition metal elements and their oxidation chemistry.

The scope of this paper is to compare commercial formulations of aqueous products containing silver for their ability to prevent termite damage by Eastern subterranean termites in a no-choice laboratory test. Five commercial products were tested in order to explore a broad range of formulation and silver forms: colloidal, ionic and nanoparticles. Southern pine wood blocks were dip treated in each solution for 30 seconds, dried and weighed. No-choice tests were run for 4 weeks at 26ºC and 85% RH. Mortality and visual ratings were recorded at the end of the test period. For comparison, some...

Nanotechnology has the potential to greatly impact the wood protection industry through the creation of nanomaterials with unique properties. Nanobiocides may find applications as co-biocides, or may alter treatability properties such as penetration and biocide distribution. Nanocarrier delivery systems may increase the applications for organic biocides through controlled release of biocide, treatment of engineered composites with heat-labile biocides, or prevention of leaching in otherwise soluble biocides. The unique properties of nanomaterials that make them attractive as preservatives...

In termites, differentiation plasticity in undifferentiated Reticulitermes progresses with growth stages from larvae to workers, which may then differentiate into soldiers, winged nymphs, or neotenics. Although studies have been done on seasonality of the termite life cycle, data appears to vary from location to location. Reticulitermes populations in Wisconsin appear to behave slightly differently in terms of colony formation and differentiation than in other parts of the continent. Timing of differentiation, feeding, and foraging behavior show some specific trends in Wisconsin termite...

In the north-eastern United States, invasive plants alter forest fuels, but their combustion characteristics are largely unknown. We assessed unground samples of foliage and twigs in the cone calorimeter for 21 non-invasive, native species, paired with 21 invasive species (18 non-native). Variables included sustained ignition, peak heat release rate, total heat release, and especially average effective heat of combustion, which is independent of initial sample mass. Heat of combustion was overall slightly lower for invasive species than for counterpart non-invasive species, and was...

Few microbes compare with the filamentous fungus Aspergillus niger in its ability to produce prodigious amounts of useful chemicals and enzymes. This fungus is the principal source of citric acid for food, beverages and pharmaceuticals and of several important commercial enzymes, including glucoamylase, which is widely used for the conversion of starch to food syrups and to fermentative feedstocks for ethanol production. Although most of these fermentation processes are well established, the underlying genetics are still poorly understood. In this issue, Pel et al. report the genome...