• Fire Science and Engineering
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• v.30 no.5
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• pp.60-66
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• 2016

This study investigated the structure and combustion characteristics of four species, Timber Douglas-fir being used construction materials (finishes), Lauan, Cryptomeria japonica, Pinus densiflora trees in the area. In lookong into the ignition characteristics was a time range of ignition (TTI) appeared in the 21 s~32 s, especially Pinus densiflora TTI is ignited in a relatively rapid 601 s to 21 s than the other materials were destroyed in the 631 s. The maximum heat release rate and average heat release rate is Pinus densiflora > Lauan > Cryptomeria japonica > Douglas-fir showed a net. Barrel emissions are Lauan > Douglas-fir > Pinus densiflora > Cryptomeria japonica was in order. The total emissions was postponed Pinus densiflora $424.80m^2/m^2$, Lauan $185.93m^2/m^2$. Douglas-fir carbon emissions of 1460, showing 0.185 kg/kg CO maximum value from s $CO_2$ values show the maximum value to 15,986 kg/kg in 750 s stopped in the 3,090 s. Next, the study suggested methods to utilize as the basic data for evaluating the safety of the fire as a building material.

• Journal of the Korean Society of Safety
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• v.32 no.3
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• pp.8-14
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• 2017

This study examined the combustion and thermal characteristics of imported woods for building materials in Korea. Wooden specimens were confirmed by a cone calorimeter according to the KS F ISO 5660-1 standard. The combustion properties of the wooden specimens were measured in terms of the heat release rate (HRR), total heat released (THR), mass lose rate (MLR), and ignition time (time to ignition; TTI). The optical microscope was used for determine the anatomical characteristics of wood pit and structure. Also, the thermal properties were measured by thermogravimetric analysis (TGA) to determine the thermal stability of wooden specimens. The result of this experiment would be useful for fundamentals of guiding the combustion properties and thermal stability using wood application.

• Journal of Mushroom
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• v.19 no.1
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• pp.9-13
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• 2021

This study was performed to find a medium material that can replace Douglas fir sawdust and rice bran in spawn media for growing spawn directly in the oyster mushroom farm. The pH range, total nitrogen source, and total carbon source of the mixed spawn medium were 5.3~5.9, 0.65~1.11%, and 47.0~49.1%, respectively. The C/N ratio was high in the mixed medium of poplar sawdust, with a low total nitrogen content. The protein content was high in the medium containing fermented Douglas fir sawdust. The mycelium growth rate was higher in the medium containing wheat bran than that in the medium containing rice bran. The highest yield per bottle was observed with poplar sawdust, oak sawdust, and rice bran mixed at a ratio of 40:40:20 (v/v/v); however, there was no significant difference observed in terms of productivity with the other treatments. Thus, when growing sawdust spawns in farms, it is efficient to use poplar sawdust, oak sawdust, and wheat bran, which are also easily available, instead of Douglas fir sawdust and rice bran.

• Journal of the Korean Wood Science and Technology
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• v.19 no.3
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• pp.72-76
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• 1991

The new preparative separation techneque of dihydroquercetin (2, 3-trans-dihdroxy-3, 3', 4', 5, 7-pentahydroxydihydroflavonol) was investigated by liquid chromatography. Also some typical coniferous wood bark were examined for the sources of dihydroquercetin. The good sources of dihydroquercetin were Douglas-fir[Pseudotsuga menziesii] bark and pitch pine [Pinus rigida] bark. There is no dependance the produced place and species dihyroquercetin which is separated by silica-gel column chromatography was taken with white needle-like crystals. This crystals were very stable in the humidity and on the light. It also can stored very long without derivatives.

• Journal of Korean Society of Forest Science
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• v.89 no.4
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• pp.463-469
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• 2000

Douglas-fir (Pseudotsuga menziesd Mirb. Franco) is highly regarded as a commercial timber species throughout the world in part due to its fast growth relative to many other species. In this study, basal area per hectare equation for Douglas-fir plantations in Southland of New Zealand has been developed based on medium measurement cycles of permanent sample plots data set. The function was developed using the algebraic difference equation method, and various sigmoid-shaped projection equations were used. Parameter estimation was obtained by non-linear routine of the SAS. As a result, of the functions tested a variant of the Schumacher polymorphic function including site index and thinning term as predictor variables showed the higher precision of the fitting. The results indicate that site index is positively correlated with basal area growth. And the thinning term was found to be useful to increase precision of the model.

• Journal of the Korean Wood Science and Technology
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• v.9 no.4
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• pp.1-21
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• 1981

Exterior grades of Douglas-fir and aspen plywood were impregnated with interior fire-retardant chemicals and redried under low-, intermediate-, and high-temperature drying conditions. Fire-retardant treatments included borax-boric acid, chromated zinc chloride, minalith, pyresote, and a commercial formulation. Drying processes included kiln and press-drying. Evaluated were drying rates and defects generated. The borax-boric acid and the commercial treatments redried at rates similar to water-treated controls. Other salt treatments were significantly slower drying and more defect prone. Chromated zinc chloride treatment was consistently the slowest drying and most defect prone. Press drying was three times faster at an equivalent temperature level. However, thickness shrinkage doubled because of 50 1b/in. platen pressure.

• Journal of Conservation Science
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• v.26 no.1
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• pp.77-83
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• 2010

The damage from the underground termite cannot be discovered with peculiar appearance of building but hollow phenomenon will occur. But there is no case in Korea as a non-destructive measurement of termite activation. Therefore, this research constructs non-destructive diagnostic techniques for wooden cultural properties using microwave detector (Termatrac, Australia). Result of maximun distance were measured 16cm (Pine tree, sensitivity 5, 6), 17cm (Zelkova and Douglas fir, sensitivity 5, 6). These results are expected that can be applied in the field. Result of field test using microwave detector, 33.8% of the wooden cultural properties were damaged by termites, and until now 7.8% (18 buildings) are being damaged in nationwide (total 231 buildings). Based on the above results, microwave detector will be able to be utilized effectively for detecting termite, preventing intrusion in wooden structure, and making full use of monitoring system periodically. In addition, it could be of great worth in preventing insect and microorganism in wooden structure.

• Journal of Mushroom
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• v.12 no.2
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• pp.117-121
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• 2014

The experiments were conducted to provide information on the chemical concentrations and cultural characteristics in the periods of hyphal incubation, primordial formation, and fruiting bodies yield of winter mushroom, Flammulina velutipes at the mixture ratio of the raw materials. Substrates were analyzed for pH, total carbon (T-C), total nitrogen (T-N), and C/N ratio. In case of Flammulina velutipes, yield of fruiting bodies were 190.5 g/850 ml in the substrates, [Corn-cob + Rice bran + Soybean curd residue (75:20:5)], which was increased 20.4% more than the control, [Douglas fir sawdust + Rice bran (75:25)]. But the periods of hyphal incubation took 28 days, which was 7 days longer than the control. Also, in the substrates [Douglas fir sawdust + Rice bran + Soybean curd residue (75:20:5)], the yields was 172.7 g/850 ml and the periods of hyphal incubation was 21 days.

• Journal of the Korean Wood Science and Technology
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• v.39 no.1
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• pp.33-40
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• 2011

In this study, we identified wood species used in manufacturing Streetcar No. 381 from Seoul Museum of History. This Streetcar No. 381 is an important cultural heritage as one of the 2 streetcars remained in Seoul. It is important to preserve this streetcar through restoration and to maintain without any damage or degradation. The information on species of wood members should be needed for its original restoration. Thus, 6 interior and 1 exterior wood members were sampled and identified microscopically. Among the 7 wood members identified, 2 were found to be douglas-fir ($Pseudotsuga$), 2 lauan ($Shorea$), 1 exotic hard pine of ponderosa group ($Pinus$), 1 larch ($Larix$), and 1 oak of cerris group ($Quercus$), respectively.

• Journal of Korean Society of Forest Science
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• v.88 no.2
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• pp.142-148
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• 1999

This research describes the construction of a site index equation and curves for Douglas-fir plantation (Pseudotsuga menziesii Mirb. Franco) in Nelson, New Zealand. The data sets of 146 Permanent Sample Plots (PSP) were used to build the model, and it was developed using the difference equation method. Parameter estimates were obtained using the non-linear routine of the SAS, PROC NLIN procedure. Of the models tested, a variant of the Schumacher polymorphic yield function showed the higher precision of fitting. About 95% of the observations used to fit the model could be predicted within ${\pm}1.2m$ of the actual values. Therefore, polymorphic family of site index curves, which reflect different shapes for the different site index classes, were derived from the Schumacher equation. It was found that the polymorphic site index equation was more accurate than the anamorphic equation in this study.