Treesearch

This study proposed a novel headspace gas chromatographic (HS-GC) method for determination of adhesive contaminants (microstickies) in recycled whitewater, a fiber containing process stream, in the paper mill. It is based on the adsorption behavior of toluene (as a tracer) on the hydrophobic surface of microstickies, which affects the apparent vapor-liquid equilibration partitioning of toluene. It was found that the equilibrium concentration of toluene in the vapor phase is inversely proportional to the apparent effective surface area of microstickies that remain in the corresponding...

Commercial softwood kraft pulp with kappa number 30.5 (KP30.5) was delignified with polyoxometalates (POM, Na5(+2)[SiV1(-0.1)MoW10(+0.1)O40]), and POM-treated kraft pulp of kappa number 23.6 was obtained (KPPOM,23.6). Residual lignin from pulps was isolated by mild acid hydrolysis and characterized by analytical and spectral methods to gain insight into lignin reactions taking place during the initial delignification phase. Lignin from POM-delignified pulp was isolated in lower yield. Comparative analysis of residual lignins (RL-KP30.5, RL-KPPOM,23.6) showed that POM leads to products...

Assessment of the quality of raw wood materials has become a crucial issue in the operational value chain as forestry and the wood processing industry are increasingly under economic pressure to maximize extracted value. A significant effort has been devoted toward developing robust nondestructive evaluation (NDE) technologies capable of predicting the intrinsic wood properties of individual trees, stems, and logs, and assessing the value of stands and forests. Such technologies can help foresters make wise management decisions, grow higher quality wood, and lead to greater profitability...

Wood-grown cultures of Daldinia concentrica oxidized a permethylated [beta]-14C- labeled synthetic lignin to 14CO2 and also cleaved a permethylated [alpha]-13C-labeled synthetic lignin to give C[alpha]-C[beta] cleavage products that were detected by 13C nuclear magnetic resonance spectrometry. Therefore, this ascomycete resembles white-rot basidiomycetes in attacking the recalcitrant nonphenolic structures that predominate in lignin.

This study evaluated the feasibility of producing value-added wood products from hemlock lumber salvaged from building deconstruction. About 6,000 board feet of lumber, ranging in size from 3 in. by 8 in. to 3 in. by 12 in., was remilled into four products including log cabin siding, V-groove paneling, beadboard (wainscoting), and tongue and groove flooring. The general quality of the products produced was high and little loss was found after processing, although checks, ringshake, and face-nail holes were found in some pieces. The yield of value-added products was rather low (about 33%)...

The number of larger, permanent softwood lumber mills in the United States and Canada has shrunk from 1,311 in 1995 to 990 as of June 2007. These mills had a combined capacity of 190.2 million m3 (80.6 × 109 board feet), slightly down from the 2005 value. In 2006, they produced 171 million (nominal) m3 (72.3 × 109 board feet) of lumber, and in the process, generated approximately 0.56 oven-dried metric tons of chips and 0.23 tons of saw-dust and shavings for every 2.36 m3 (1,000 board feet) of lumber produced. Of the chips, 95% were used for pulp and the contribution of this product stream...

For normally distributed populations, we obtain confidence bounds on a ratio of two coefficients of variation, provide a test for the equality of k coefficients of variation, and provide confidence bounds on a coefficient of variation shared by k populations. To develop these confidence bounds and test, we first establish that estimators based on Newton steps from n-consistent estimators may be used in place of efficient solutions of the likelihood equations in likelihood ratio, Wald, and Rao tests. Taking a quadratic mean differentiability approach, Lehmann and Romano have outlined proofs...

Reliability estimates for the resistance distribution of wood product properties may be made from test data where all specimens are broken (full data sets) or by using data sets where information is obtained only from the weaker pieces in the distribution (censored data). Whereas considerable information exists on property estimation from full data sets, much less information is available on property estimation using censored data. To assess the need for a more rigorous study, a small simulation study was conducted to identify potential problems that could be associated with censoring...

Located in 23 countries, 40 forest-products research and development organizations outside the United States were reviewed in 2004 and 2005. The intent was to obtain a better understanding of how such organizations are structured and administered and their performance judged. Investing over $600 million annually, the 40 organizations employed 7,000 to 7,500 scientists and supporting staff. Especially noteworthy about the organizations are the many ways in which they identify themselves (such as institutes, laboratories, centers); their long history of sustained involvement in forest...