Treesearch

This paper is an overview of what we know about occurrence of wood decay above ground within buildings. It presents information concerning under what conditions decay may become established. In laboratory tests involving optimum moisture and temperature conditions for decay fungi, and direct contact with large quantities of specific well-developed decay fungi, substantial decay in small specimens of untreated wood of nondurable species can occur in a few weeks. The simultaneous occurrence of optimum conditions for decay and high degree of inoculation with mature decay fungi is probably...

On account of its distinctive features, Setchellanthus cannot be included within any of the families of glucosinolate-producing plants. Features unknown in any of these families include abundant vasicentric tracheids, abaxial axial parenchyma, and only short uniseriate rays (composed of upright cells) in wood: and the presence of wide-helix tracheary elements in leaves. Wood offers the greatest number of phyletically significant features, and wood of Capparaceae offers many similarities, although the wood of Helianthemum (Cisraceae) is even more like that of Setchellanthus. Despite the...

As a result of a United States Postal Service (USPS) initiative, a work team consisting of the USPS, the Forest Products Laboratory (FPL),Springborn Testing and Research (STR), and industry representatives wasformed. The industry representatives include papermakers, paper recyclers,paper collectors, equipment manufacturers, paper users, and adhesive and chemical suppliers. The objective of the work team is to develop new and innovative solutions to the problems associated with recycling recovered paper containing pressure-sensitive adhesives (PSAs). Initial open discussions were held at...

As a result of a United States Postal Service (USPS) initiative, a work team was formed consisting of representatives from USPS, Forest Products Laboratory (FPL), Specialized Technology Resources, Inc. (STR), and industry. The industries represented included papermakers, paper recyclers, paper collectors, equipment manufacturers, paper users, adhesive manufacturers and chemical suppliers. The objective of the work team is to develop new and innovative solutions to problems associated with recycling paper containing pressure sensitive adhesives (PSAs). Based on criteria developed by the...

In the area of photoyellowing of mechanical pulps, recently obtained experimental evidence has shown that hydroquinone/p-quinone redox couple is present in lignin-rich mechanical pulps. It was also noted that compared to a control pulp the concentration of p-quinones was significantly higher in a photoyellowed pulp. Under ambient conditions, upon exposure to light, the existent pulp hydroquinones were converted to p-quinones. To further investigate the importance of hydroquinone/p-quinone redox couple in photoyellowing, studies of methylhydroquinone and methyl-p-quinone were carried out....

Mechanical pulping process is electrical energy intensive and results in low paper strength. Biomechanical pulping, defined as the fungal treatment of lignocellulosic materials prior to mechanical pulping, has shown at least 30% savings in electrical energy consumption, and significant improvements in paper strength properties compared to the control at a laboratory scale. In an effort to scale-up biomechanical pulping to an industrial level, fifty tons of spruce wood chips were inoculated with the best biopulping fungus in a continuous operation and stored in the form of an outdoor chip...

The structures of native celluloses have traditionally been presented in terms of two-domain models consisting of crystalline and non-crystalline fractions. Such models have been of little help in advancing understanding of enzyme-substrate interactions. In this report we first address issues that complicate characterization of the structure of native celluloses particularly with respect to information that may be relevant to understanding susceptibility to enzyme action. Key among these is the fact that crystallographic models define structure primarily at the level of the unit cell while...

Wood- and nonwood-based fibers have been found to have a significant sorption capacity for ionized copper, a heavy metal commonly found in stormwater. The USDA-FS Forest Products Laboratory (Madison, WI) is conducting research on the potential of utilizing natural wood- and nonwood-based fibers in stormwater treatment. The problem with the current practice of stormwater filtration is that it requires a large area, can be very expensive, and typically does not solve the problem of fine suspended particles or dissolved pollutants. The integration of these fibers into a stormwater filtration...

Lignocellulosic materials were evaluated for their effectiveness in filtering toxic heavy metals from stormwater. Kenaf, alfalfa, juniper, and aspen fibers were used as models to evaluate the effectiveness and limitations of chemical modification and the extent of fiber degradation. Individual and mixed aqueous solutions of nickel, copper, zinc, and cadmium in various concentrations were exposed to the lignocellulosic fibers to estimate ion-exchange capacity and competition between ionic species. The potential of lignocellulosic fibers to act as filters is related to their sugar, extractive...

The efficacy of fiber length measurement techniques such as digitizing, the Kajaani procedure, and NIH Image are compared in order to determine the optimal tool. Kenaf bast fibers, aspen, and red pine fibers were collected from different anatomical parts, and the fiber lengths were compared using various analytical tools. A statistical analysis on the validity of the fiber length measurements of each method was obtained. Using this analysis, a relationship was developed between fiber length, growth, and pulping conditions.