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Southern blot and nucleotide sequence analysis of Phanerochaete chrysosporium BKM-F-1767 genomic clones indicate that this wood-degrading fungus contains at least six genes with significant homology to the Trichoderma reesei cellobiohydrolase I gene (cbh1). Using pulsed-field gel electrophoresis to separate P. chrysosporium chromosomes, the six cellulase genes were found to hybridize to at least three different chromosomes, one of which is dimorphic. The organization of these genes was similar in another P. chrysosporium strain, ME 446. It is clear that, unlike T. reesei, the most well-stud...

Lignin peroxidases (LiP) of Phanerochaete chrysosporium are encoded by a family of six closely related genes. Five LiP genes have been localized to the same dimorphic chromosome. In this investigation, relative transcript levels of the LiP genes were determined. Transcripts of the LiPA, LiPB, and 0282 genes were at similar levels in both carbon-and nitrogen-limited cultures. In contrast, transcription of the GLG5, V4, and GLG4 genes was dramatically altered by culture conditions. Under carbon-limited conditions, GLG4 transcripts were, by far, the most abundant. Southern blot analyses of...

Low-expansivity alloys have the potential to reduce thermal instability of sawblades during the sawing operation. In preliminary industrial trials of sawblades made of low-expansivity alloy, sawing accuracy was improved 22 to 38 percent during normal sawing. When saws made of a low-expansivity alloy were operated with a large temperature gradient across the blade, sawing accuracy was comparable to that of steel saws operated with little temperature gradient.

This paper focuses on the characterization and the performance of glued laminated (glulam) timber beams manufactured from machine stress graded Norwegian spruce in comparison to developing CEN standards. Material property testing indicated that the supplied laminating timber can be represented by two CEN strength classes, C37-14E and C30-12E, with about 50% yield in each class. Beams constructed from these grades exhibited strength and stiffness meeting the requirements of CEN combinations LH35, LH40 and LC38.

Compartment fire zone models are based on many simplifying assumptions, in particular that gases stratify in two distinct layers. Because of these assumptions, certain model output is in a form unsuitable for direct comparison to measurements made in full-scale room tests. The experimental data must first be reduced and transformed to be compatible with the model output. In this article, new techniques are described to calculate neutral plane height, vent flow rates, uniform upper and lower layer temperature and interface height from measured temperature profiles. The new calculation...

Burning rate is a key factor in modeling fire growth and fire endurance of wood structures. This study investigated the burning rate of selected wood materials as determined by heat release, mass loss and charring rates. Thick samples of redwood, southern pine, red oak and basswood were tested in a heat release rate calorimeter. Results on ignitability and average beat release, mass loss and charring rates are reported for a heat flux range between 15 and 55 kW m -2. In this range, burning rate increased linearly with heat flux. Burning rate was very species dependent. Heat release rate...

This article updates a previous literature review paper on the performance of woodframe buildings during earthquakes and summarizes recent research related to understanding seismic behavior of low-rise wood buildings.

This report contains a set of FORTRAN subroutines written to calculate the Hasofer-Lind reliability index. Nonlinear failure criteria and correlated basic variables are permitted. Users may incorporate these routines into their own calling program (an example program, RELANAL, is included) and must provide a failure criterion subroutine (two example subroutines, LINFAIL and YLINEN, are included).

One barrier to producing wood-plastic composites with wood fiber is the poor thermoplasticity of wood fiber. The objective of our study was to determine the plasticization of chemically modified wood fiber through tests on unmodified and esterified fiberboards. Attrition-milled aspen fiber was esterified with neat acetic, maleic, or succinic anhydride. Fourier transform infrared spectroscopy, gas liquid chromatography, and titrational methods were used to confirm derivatization and to characterize the end products of the esterification reaction. All anhydrides formed a simple monoester;...

Practical and cost-effective uses for peroxymonosulfate can be developed in pulping and bleaching. Peroxymonosulfate pulping produces strong pulps, has lower capital requirements, and is less environmentally troublesome compared with current pulping processes. The cost of oxidant may, however, be somewhat too high for practical use. We discuss means for reducing the cost and for disposal or recovery of the spent treating liquors. Low-lignin chemical pulps were effectively bleached by alkaline solutions of peroxymonosulfate. Our results indicate that a practical bleaching sequence can...