http://hdl.handle.net/1957/22029 2013-06-19T01:48:41Z 2013-06-19T01:48:41Z Schauwecker, Christoph F. McDonald, Armando G. Morrell, Jeff J. http://hdl.handle.net/1957/38295 2013-04-23T15:36:15Z 2013-02-01T00:00:00Z

Performance of wood treated with prospective organic surface protectants upon outdoor exposure: FTIR spectroscopic analysis of weathered surfaces Schauwecker, Christoph F.; McDonald, Armando G.; Morrell, Jeff J. Visual appeal of wood is as important as its structural integrity in outdoor applications. Discoloration and checking of wood favor the utilization of alternative materials for outdoor cladding and decking. Lignin depolymerization is one of the critical processes leading to weathering. In the present paper, the potential of different classes of surface protection agents has been assessed on loblolly pine ( Pinus taeda ) impregnated with water repellents, organic UV inhibitors, and an organic biocide. The treated samples were exposed to predetermined doses of solar radiation in Eastern Oregon, and the chemical changes occurring on the surfaces were evaluated by FTIR spectroscopy. After 1-year exposure, lignin loss was complete on all surfaces; however, some treatments provided longer term protection than others. Organic UV light inhibitors were most effective in this regard. A petroleumbased water repellent with a melting point of 54 – 58 ° C also provided protection against lignin degradation. This is the publisher’s final pdf. The published article is copyrighted by De Gruyter and can be found at: http://www.degruyter.com/.

2013-02-01T00:00:00Z Reed, Daniel Bergman, Richard Kim, Jae-Woo Taylor, Adam Harper, David Jones, David Knowles, Chris Puettmann, Maureen E. http://hdl.handle.net/1957/36841 2013-02-13T21:02:24Z 2012-01-01T00:00:00Z

Cradle-to-Gate Life-Cycle Inventory and Impact Assessment of Wood Fuel Pellet Manufacturing from Hardwood Flooring Residues in the Southeastern United States Reed, Daniel; Bergman, Richard; Kim, Jae-Woo; Taylor, Adam; Harper, David; Jones, David; Knowles, Chris; Puettmann, Maureen E. In this article, we present cradle-to-gate life-cycle inventory (LCI) data for wood fuel pellets manufactured in the Southeast United States. We surveyed commercial pellet manufacturers in 2010, collecting annual production data for 2009. Weighted-average inputs to, and emissions from, the pelletization process were determined. The pellet making unit process was combined with existing LCI data from hardwood flooring residues production, and a life-cycle impact assessment was conducted using the Tool for the Reduction and Assessment of Chemical and Other Environmental Impacts (TRACI) model. The potential bioenergy and embodied nonrenewable energy in 907 kg (1 ton, the functional unit of this study) of wood fuel pellets was also calculated. The pelletization of wood requires significant amounts of electrical energy (145 kWh/Mg), but the net bioenergy balance is positive. Wood pellets require 5.8 GJ of fossil energy to produce 17.3 GJ of bioenergy (a net balance of 10.4 GJ/Mg). However, if environmental burdens are allocated to the pellet raw material (flooring residues) by value, then the embodied fossil energy is reduced to 2.3 GJ. The pelletization unit process data collected here could be used in an assessment of the environmental impacts of pellet fuel, or when pellets are a pretreatment step in wood-based biorefinery processes. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Forest Products Society and can be found at: http://www.forestprod.org/.

2012-01-01T00:00:00Z Voelker, Steven L. Noirot-Cosson, Paul-Emile Stambaugh, Michael C. McMurry, Erin R. Meinzer, Frederick C. Lachenbruch, Barbara Guyette, Richard P. http://hdl.handle.net/1957/36612 2013-02-06T21:13:54Z 2012-05-01T00:00:00Z

Spring temperature responses of oaks are synchronous with North Atlantic conditions during the last deglaciation Voelker, Steven L.; Noirot-Cosson, Paul-Emile; Stambaugh, Michael C.; McMurry, Erin R.; Meinzer, Frederick C.; Lachenbruch, Barbara; Guyette, Richard P. Paleoclimate proxies based on the measurement of xylem cell anatomy have rarely been developed across the temperature range of a species or applied to wood predating the most recent millennium. Here we describe wood anatomy-based proxies for spring temperatures in central North America from modern bur oaks (Quercus macrocarpa Michx.). The strong coherence of temperature signals across the species range supports the use of these proxies across thousands of years of climatic change. We also used 79 subfossil oak log cross sections from northern Missouri, ¹⁴C-dated to 9.9-13.63 ka (ka is 1000 cal yr BP), to assess the frequency of oak deposition into alluvial sediments and a subset of these oaks for a wood anatomy-based reconstruction of spring paleotemperatures. Temperatures during the Younger Dryas cold period (YD) were up to 3.5 degrees C lower than modern temperatures for that region, equivalent to or lower than those experienced at the northern edge of the modern species range. Compared to extant oaks growing at much higher [CO₂], subfossil oaks had greater vessel frequencies. Besides very low theoretical (or estimated) xylem conductivity near the beginning of the oak record near 13.6 ka, vessel frequencies greater than modern trees compensated for reduced vessel dimensions so that theoretical xylem conductivity was consistently above that of modern trees at the cold northern sites. Significant correlations were found between the frequency of ¹⁴C-dated oaks and either delta δ¹⁸O from the NGRIP (North Greenland Ice Core Project) ice core or from the Cariaco grayscale marine-sediment record from the southern Caribbean sea. Oak deposition into alluvial sediments during the YD was significantly lower than expected given the average sample depth of oaks from 9.9 to 13.6 ka. Reduced oak deposition during the YD suggests that an abrupt shift in climate reduced oak populations across the region and/or changed the rates of channel movement across drainages. To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by Ecological Society of America and can be found at: http://www.esa.org/.

2012-05-01T00:00:00Z van de Lindt, John W. Gupta, Rakesh Pei, Shiling Tachibana, Kazuki Araki, Yasuhiro Rammer, Douglas Isoda, Hiroshi http://hdl.handle.net/1957/36316 2013-01-23T23:33:07Z 2012-01-01T00:00:00Z

Damage Assessment of a Full-Scale Six-Story Wood-Frame Building Following Triaxial Shake Table Tests van de Lindt, John W.; Gupta, Rakesh; Pei, Shiling; Tachibana, Kazuki; Araki, Yasuhiro; Rammer, Douglas; Isoda, Hiroshi In the summer of 2009, a full-scale midrise wood-frame building was tested under a series of simulated earthquakes on the world's largest shake table in Miki City, Japan. The objective of this series of tests was to validate a performance-based seismic design approach by qualitatively and quantitatively examining the building's seismic performance in terms of response kinematics and observed damage. This paper presents the results of detailed damage inspections following each test in a series of five shake table tests, and explains their qualitative synthesis to provide design method validation. The seismic test program had two phases. Phase I was the testing of a seven-story mixed-use building with the first story consisting of a steel special moment frame (SMF) and stories 2-7 made of light-frame wood. In Phase II, the SMF was heavily braced such that it effectively became an extension of the shake table and testing was conducted on only stories 2-7, making the building a six-story light-frame multifamily residential building instead of a mixed-use building. All earthquake motions were scalings of the 1994 Northridge earthquake at the Canoga Park recording station with seismic intensities ranging from peak ground accelerations of 0.22 to 0.88 g. The building performed quite well during all earthquakes with damage only to the gypsum wall board (drywall), no sill plate splitting, no nails withdrawing or pulling through the sheathing, no edge tearing of the sheathing, no visible stud splitting around tie-down rods, and reasonable floor accelerations. On the basis of damage inspection, it was concluded that it is possible to design this type of building and keep the damage to a manageable level during major earthquakes by utilizing the new design approach. DOI: 10.1061/(ASCE)CF.1943-5509.0000202. (C) 2012 American Society of Civil Engineers To the best of our knowledge, one or more authors of this paper were federal employees when contributing to this work. This is the publisher’s final pdf. The published article is copyrighted by American Society of Civil Engineers and can be found at: http://www.asce.org/.

2012-01-01T00:00:00Z