• Journal of the Korean Wood Science and Technology
• /
• v.19 no.4
• /
• pp.34-42
• /
• 1991

Protection of tropical forest affects on significant reduce of tropical hardwood supply, and softwood resources will be increasingly important for the timber security in Korea. U.S. softwood log was most favorite species for Korean softwood log importers in overall import conditions except price stablization and consistency of export policy. Reduced export volume from Pacific Northwest to Korean market has been immediately replenished by rediata pine from New Zealand and Chilean plantation. Siberian timber will hardly play major roles in Korean timber market unless budding structure. softwood plywood and softwood furniture uses are enhanced. Recent rapid rise of labor cost and reducing tariff rrate in Korea provided better opportunities for import lumber in building materials market. Dry dimension lumber was relatively profitable when processed from import U.S. soft-wood log while green lumber was favorable products processed from radiata pine log in Korean lumber market. This means U.S. softwood lumber would have better opportunity to market for '2${\times}$'4 studs when wood frame housing is introduced. On the other hand while radiata pine is competitive on temporary construction lumber such as supporter and concrete forming frame in Korea. Shortage of raw material for the new capacity of board plants in Korea will be it bottle neck. Major log export countries to Korea as U.S. New Zealand and Chile showed high trade intensity indices of composite hoard produces for Korean market. As Korea efforts to diversify import sources, and tariffs are reduced to 8% as scheduled by 1994. countries of scoring higher comparative advantages as Portugal. Brazil, Austria as well as New Zealand will have better opportunity to penetrate into promised Korean composites hoard market.

• Journal of Korea Foresty Energy
• /
• v.25 no.2
• /
• pp.49-54
• /
• 2006

This study was carried out to provide basic data for using domestic structural softwood lumber efficiently and ensuring structural safety of timber structures. The ratios (k-factor) between static and dynamic MOE measured by ultrasonic device for $2{\times}6$ domestic softwood structural lumber are 1.0602 for Korean red pine, 1.0013 for Korean white pine and 1.2320 for Japanese larch. In machine grade using nondestructive method, 76% of Korean red pine was classified into higher than E9 grade, 85% of Korean white pine was sorted into higher than E7 grade and 68% of Japanese larch was classified into higher than E11 grade. Correlation between MOE and MOR by static bending with k-factor from nondestructive method provide a possibility to predict bending strength and allowable stress of domestic softwood structural lumber.

• Korean Journal of Poultry Science
• /
• v.34 no.1
• /
• pp.15-21
• /
• 2007

This study was conducted to evaluate the effects of dietary softwood by-products extract on growth performance, organ weight and intestinal microbes in organic broiler chicks. Five treatments were assigned to 200 broiler chicks with four replication, allocating 10 broiler chicks in each replication. Dietary treatments included control(Organic diet), +C(Organic diet + antibiotics), T1(Organic diet + softwood by-product powder 3.0%), T2(Organic diet + softwood by-product extract 0.05%) and T3(Organic diet + softwood by-product extract 0.1%). Body weight gain was higher in +C and T3 for overall period than control and T1. Feed efficiency of were slightly improved in +C and T3 groups compared with that of control and T1. The small intestine weight tended to be higher in control and +C, but it's length showed high in only T1 group. Gizzard weight was significantly higher in T2 compared with other treatments(P<0.05). In contrast, spleen weight was significantly lower in control group(P<0.05), whereas the weight of cecum and liver were not significantly different by dietary treatment. Intestinal microflora was significantly lower or/and seemed to be low in softwood by-products treatment groups than control. Digestibility of energy and protein were statistically lower in control and T1 than other treatments(P<0.05). The IgG concentration of birds fed antibiotics, softwood by-product extract was higher than control and T1, but was no significance. The results of this experiments indicated that softwood by-product extract would be possible to apply for the feed additive in organic broiler diets.

• Journal of the Korea Furniture Society
• /
• v.26 no.3
• /
• pp.222-228
• /
• 2015

To evaluate the natural decay durability of valuable domestic softwoods which are used for preservative treatment in our country, we carried out decay test by European standard method. Of all test wood species, Japanese larch (Larix leptolepis) showed slightly high natural decay durability compared to other 4 wood species, Japanese red pine (Pinus densiflora), pitch pine (Pinus rigida), Japanese cedar (Cryptomeria japonica), and scots pine (Pinus sylvestris). However, all of evaluated domestic softwood species in this study caused high weight losses over about 30% in heartwood by test fungus, Poria placenta. We can hardly expect a good natural decay durability from these softwood species. According to the classification of the natural durability of European standard (EN 350-1), they are classified into "Not durable" or "Slightly durable". Therefore, if using these softwoods as exterior materials, we must do preservative treatment to ensure durability.

• Journal of the Korean Wood Science and Technology
• /
• v.38 no.5
• /
• pp.429-438
• /
• 2010

In this study, effect of carbon source on the hydrolytic ability of the enzyme from Fomitopsis pinicola, a brown rot fungi, for lignocellulosic biomass were examined on two lignocellulosic biomasses (rice straw and wood) without any pretreatment. Cellulase activities of crude enzyme from F. pinicola, which was cultured on softwood mixture as a carbon source, were 19.10 U/$m{\ell}$ for endo-${\beta}$-1,4-gulcanase (EG), 36.1 U/$m{\ell}$ for ${\beta}$-glucosidase (BGL), 7.27 U/$m{\ell}$ for cellobiohydrolase (CBH), and 7.12 U/$m{\ell}$ for ${\beta}$-1,4 xylosidase (BXL). Softwood mixture as a carbon source in F. pinicola comparatively enhanced cellulase activities than rice straw. The optimal pH and temperature of the cellulase was identified to pH 5 and $50^{\circ}C$for the hydrolysis of rice straw. Under these condition rice straw was hydrolyzed to glucose by the cellulase up to $32.0{\pm}3.1%$ based on the glucan amount of the rice straw for 72 h, while the hydrolytic capability of commercial enzyme (Celluclast 1.5${\ell}$) from rice straw to glucose was estimated to $53.7{\pm}4.7%$ at the same experimental condition. In case of addition of Tween 20 (0.1% w/w, substrate) to the cellulase the hydrolysis of rice straw to glucose was enhanced to $38.1{\pm}2.0%$.

• Journal of the Korea Furniture Society
• /
• v.25 no.3
• /
• pp.233-237
• /
• 2014

The eco-friendly preservatives such as ACQ or CUAZ have been used in landscape architectural facilities these days. In this study, the decay efficacies of ACQ treatments were evaluated according to domestic veneer species, concentration of ACQ, weathering test, adhesive type, and fungus type. In case of veneer species, hinoki cypress and yellow poplar showed the highest and lowest decay resistance, respectively. And the decay resistance appeared to be greater in plywoods bonded by resorcinol resin-bonded plywood and non-weathering treated plywood than polyurethane resin-bonded plywood and weathering treated plywood.

• Journal of the Korean Wood Science and Technology
• /
• v.31 no.6
• /
• pp.55-59
• /
• 2003

The fixation and leaching characteristics of chromated copper arsenate (CCA Type C) and chromium- copper-fluoride-zinc (CCFZ) in domestic softwood (Japanese red pine, Korean pine, and Japanese larch) sapwood were investigated using the expressate method to follow chromium fixation and the American Wood-Preservers' Association (AWPA) leaching procedure to determine leaching properties after fixation. The rates of fixation were affected by preservative types; CCA was fixed much faster than CCFZ for all species evaluated. There were definite differences in the fixation rates of different species, with Korean pine requiring shorter to fix than the other species evaluated. Chromium fixation was greatly enhanced by elevated temperatures, and fixation time can be estimated according to fixation temperatures applied. The percentage of arsenic and zinc leached from domestic softwoods was relatively high compared to chromium and copper, indicating that there is still a relatively high unfixed arsenic and zinc components after complete chromium fixation in CCA-and CCFZ-treated samples, respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
• /
• v.47 no.5
• /
• pp.68-73
• /
• 2015

Electron beam irradiation is also an eco-friendly treatment compared to other physical and chemical treatments. In this study, we attempted to evaluate the possibilities of energy savings by applying electron beam irradiation to the refining process. After softwood unbleached kraft pulp (UKP) was irradiated with electron beams at 50 and 100 kGy, it was beaten in a laboratory beater, and then its freeness and fiber properties were analyzed. The physical properties of their fiber handsheet were also and measured. As the irradiation dose of the electron beam and the beating time increased, lower freeness and fiber lengths of the UKP were observed. Handsheets made from UKP that was irradiated by electron beam and beaten showed a reciprocal relationship with the irradiation dose of the electron beam, in particular, the strength of the handsheets decreased dramatically at 100 kGy of irradiation. Therefore, it was confirmed that electron beam irradiation is effective in reducing the beating time or beating energy. But the irradiation dose must be controlled under 50 kGy to minimize the loss of paper strength.

• Korean Journal of Environmental Biology
• /
• v.17 no.2
• /
• pp.191-198
• /
• 1999

Enzyme-aided bleaching of softwood and hardwood kraft pulps by a xylanase preparation from an alkalophilic fungus Cephalospotium sp. RYM-202 was studied. Maximal solubilization of Pulp xylan was obtained at 5$0^{\circ}C$ in both kraft pulps. The optimum pH of the enzyme for the hydrolysis of pulp xylan was 8.0 and more than 90% of the maximal activity was detected at 9.0. The positive effects of xylanase pretreatment on bleachability of softwood and hardwood kraft pulps were observed. The kappa number of softwood and hardwood kraft pulps was decreased by 3.7 and 2.0 units, respectively. The pulp fibre integrity was not significantly affected by xylanase pretreatment when the physical properties of handsheets made from xylanase-treated pulps were compared with those of handsheets from untreated pulps. These results indicate that the alkaline xylanase of Cephalospotium sp. RYM-202 is well suitable for application in enzymatic prebleaching of softwood and hardwood kraft pulps under the alkaline conditions.

• Korean Chemical Engineering Research
• /
• v.50 no.2
• /
• pp.385-389
• /
• 2012

In this study, torrefaction of mixed softwood chips under anoxic condition was performed to improve energy density and maintain consistent quality of biomass. Characteristics of torrefied biomass depending on reaction time (30 min) and temperature (240, 260,$280^{\circ}C$) were investigated. Torrefaction of mixed softwood chips significantly improved the heating value compared to that of untreated biomass. As the torrefaction temperature was increased, the carbon content of torrefied biomass increased from 46.55 to 55.73%, while its hydrogen and oxygen contents decreased from 6.00 to 5.87% and from 30.55 to 27.21%, respectively. Most of hemicelluloses and volatile compounds were removed during torrefaction. The highest heating value was 5132 kcal/kg when torrefaction was performed at$280^{\circ}C$ for 30 min. It implied that the heating value increased by 13% compared to that of original biomass. However, the condition of effective torrefaction was at $240^{\circ}C$ for 30 min when weight loss and energy yield was considered.