This research investigates the effect of copper retention on copper leaching in wood treated with copper-based preservatives. Radiata pine (Pinus radiata D. Don) sapwood samples were ground in a Wiley mill equipped with a 20-mesh screen. The ground wood was vacuum-treated with various concentrations of alkaline copper quat (ACQ), bis-(N-cyclohexyl-diazeniumdioxy)-copper (CB-HDO), and copper azole (CUAZ). The treated samples were conditioned at $70^{\circ}C$ and 100% RH for 72 hours. The samples were leached by using the distilled water for four weeks, and the copper contents in each sample were measured by X-ray spectroscopy. As expected, the copper leaching was increased with increasing of copper retention. The copper leaching from the ACQ and CB-HDO treated samples were gradually decreased with increasing copper retention: however, the copper losses from the CUAZ treated samples appeared to be proportionally increased with the increase in copper retention in all retention levels tested. The results indicate that at the conditions of the same copper retention ACQ and CB-HDO treated wood have a better leaching resistance compared to CUAZ treated wood.

This study investigates the tensile and morphological properties of nanocomposites prepared from poly(lactic acid) (PLA), wood flour (WF) and montmorillonite (MMT) by melt compounding with a twin screw extruder. In order to enhance the mechanical properties of PLA/WF composites, maleic anhydride grafted PLA (MAPLA) is synthesized as a compatibilizer. MAPLA prepared in the laboratory is characterized using FT-IR (Fourier transformed infrared spectroscopy). From the results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) analysis for nanocomposites, we confirmed that silicate layers of MMT are intercalated and partially exfoliated. When 2 wt% MAPLA is added, the tensile strength and modulus of PLA/WF/MAPLA composites were higher than those of the PLA/WF composite. The addition of MMT increases the tensile modulus of PLA/WF/MAPLA composites but decreases the tensile strength.

This study investigates the thermal properties of nanocomposites prepared from poly(lactic acid) (PLA), wood flour (WF) and montmorillonite (MMT) by melt compounding with a twin screw extruder. In order to enhance the mechanical properties of PLA/WF composites, maleic anhydride grafted PLA (MAPLA) is synthesized as a compatibilizer. MAPLA prepared in the laboratory is characterized using FR-IR. From SEM microphotographs, the presence of MAPLA has a positive effect on the mechanical properties of WF-reinforced PLA composites. The addition of WF/MAPLA into neat PLA increased the glass transition temperature ($T_g$). The addition of 1 to 5 wt% MMT into PLA/WF/MAPLA composite decreases the $T_g$. The cold crystallization temperature ($T_{cc}$) was decreased by the addition of MMT. The MMT could act as effective nucleating sites of PLA crystallization. The thermal stability evaluated by thermogravimetric analysis (TGA) is improved with the contents of MMT up to 3 wt%.

In case of wood flooring, the high emissivity would be one of the most important properties especially as the cover material of underfloor heating system. The FIR (Far Infrared) materials such as wood emit FIR energy by heating, which has been used as the medical therapy such as dry sauna. This research investigated the emissivity and the emission power of wood composites by comparing the amount of the three heat transfer modes transferred by infrared radiation which came from the increased temperature of the bottom board of the plywood box by the heater. The results showed the value of radiation mode was the highest mode for the plywood box, and the convection mode was the main mode for the aluminum box. The rate of convection was 81.8% in the aluminum box and 48.2% in the plywood box, respectively. In case of the rate of radiation, the aluminum box showed only 15.4% and the plywood box showed 51%. The emissivity and the emission power of birch plywood showed the same values as those of wood. The amount of energy required for the temperature rising of water within vial in the aluminum box and in the plywood box were 3.32 kJ and 6.70 kJ respectively, which showed that the vial temperature of the plywood box was two times higher than that of the aluminum box.

Anatomical comparison of 8 North American species of Abies was executed to provide taxonomic information. The species of eastern (balsam and Fraser fir) and western (Pacific silver, white, grand, subalpine, California red, and noble fir) were found to be separated on the basis of crystals and color of contents in ray parenchyma cells and ray height. In eastern species, crystals in ray parenchyma cells were absent and ray parenchyma cell contents were colorless to very light. These two eastern species were further characterized by the absence of uniseriate rays exceeding 25 cells in height. In western species, only subalpine fir had colorless to very light contents but the remaining five species have dark contents in ray parenchyma cells. Crystals were absent to extremely sparse in Pacific silver fir, somewhat frequent in noble fir, frequent in grand and California red fir, and very frequent in white fir. Uniseriate rays exceeding 25 cells in height were regularly found in grand and California red fir but absent in white and noble fir.

This study was conducted to find the relationship between the moisture content and basic density of green lumber and the final moisture content of kiln dried lumber. The possibility of using a ultrasonic nondestructive testing technology was investigated. Four matched 2-foot long boards were kiln-dried for 12, 24, 36 and 48 hours. Twenty three slices were cut to examine the distribution of moisture content along the length. It was revealed that the green weight was a better estimator of the final moisture content of the kiln-dried board than the green moisture content. The standard deviations of the moisture contents of the slices were not correlated with the final moisture contents of the kiln-dried boards. The two ultrasonic devices used for this study were apparently good tools for NDT.

Three failure theories were studied to evaluate the wood strength variation with grain slope. Maximum stress theory, Tsai-Hill theory and Hankinson formula were presented to hypothesize the failure of wood according to grain slope to loading direction. Red pine and Japanese larch were used as materials to simulate failure strength prediction with grain slope. Calculation of strength results was that the strength of wood drops rapidly between parallel to grain orientation (0 degree) and 15 degree grain orientation. The strength of wood with grain orientation were somewhat different at small grain angles among failure theories, and this tendency was due to tension and compression distinction, and shear accounting in each theories. For the above 45 degree grain orientation, the predicted failure strength of wood with grain variation were very close in each failure theories and were useful in assessing failure strength of wood. The applicable these theories should be considered that the wood has different behavior in tension and compression, and this lead to different strength at small grain angles in each theories. Furthermore, reconsideration is needed to assess the failure strength of wood at small grain angles in Hankinson formula and further studies are necessary to accounting for shear behavior at small grain angles.

Pinus koraiensis inner bark was collected and extracted with 95% ethanol. The extracts were concentrated and then sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc, and $H_2O$ to be freeze dried. A portion of EtOAc fraction (6.6 g) was chromatographed on a Sephadex LH-20 column using aqueous methanol to isolate (+)-catechin (1), (-)-epicatechin (2), and trans-pinostilbenoside (3). Resveratrol (4) and trans-pinostilbene (5) were isolated by column chromatography using EtOH-hexane mixture after purification with aqueous methanol. The structures of these stilbenosides and flavans were characterized by spectroscopic tools using NMR and MS.

Juglans mandshurica bark was collected and extracted with 70% aqueous acetone. The extracts were concentrated and then sequentially fractionated using n-hexane, $CH_2Cl_2$, EtOAc, and $H_2O$ to be freeze dried. A portion of $H_2O$ fraction was chromatographed on a Sephadex LH-20 column using aqueous methanol to isolate (S)-2,3-HHDP-D-glucopyranoside (1). Some of EtOAc fraction was also treated on a Sephadex LH-20 column using aqueous methanol and EtOH-hexane mixture to purify pedunculagin (2). The structures of these two epimeric ellagitannins were elucidated by spectroscopic tools, NMR and MS.