• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.1
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• pp.65-73
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• 2012

Nowadays, the concern on the environmental load of bleaching process gave rise to the process of ECF(elemental chlorine free) and TCF(total clorine free). These sequences are based on oxygen-derived compounds such as oxygen, ozone, and hydrogen peroxide which is used as a typical eco-friendly bleaching agent. In this study, paper mulberry pulp was bleached with hydrogen peroxide and some bleaching process were accompanied with ultrasonication in order to increase the bleaching efficiency. The best bleaching efficiency of paper mulberry pulp was obtained in the condition of hydrogen peroxide and ultrasonication(20 kHz) bleaching system at $45^{\circ}C$ for 30 min. The brightness and kappa number of paper mulberry pulp were gained to 5.09% and 3.52 respectively. and yield was slightly loosed to 2%. Therefore, the efficiency of hydrogen peroxide and ultrasonication bleaching system of paper mulberry pulp was superior to the conventional hydrogen peroxide bleaching system. Magnesium sulfate acted as a bleaching stabilizer for the increasement of yield. As a result, the yield and viscosity were increased to 2.2% and 12% respectively.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.1
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• pp.24-30
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• 2012

This study was carried out in order to analyze a repletion possibility about color change of base paper after elevated heat exposure when wooden fillers were added. Fillers may reduce production cost because its price is usually inexpensive than pulp with higher bulkiness. Wooden fillers have lower density than inorganic fillers, so they may increase bulk more than inorganic fillers. Never the less wooden fillers have disadvantage of yellow color by heat exposure, so the addition level should be carefully controlled. Brightness and whiteness changes after elevated heat exposure depending on coating weight were analyzed. With wooden fillers addition, breaking length and surface strength decreased but bulkiness increased. As the exposure time of elevated heat increased the coating paper with wooden fillers addition had higher brightness and whiteness values than those of inorganic fillers.

• Journal of the Korean Wood Science and Technology
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• v.44 no.4
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• pp.494-504
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• 2016

Eucalyptus oils are widely used as spices, perfume industrial materials, food flavorings, and medicines. Several types of Eucalyptus oils also have insecticidal activity and as carminative. This study investigated the chemical composition, insecticidal (larvicidal and repellent) activity of E. urophylla oil against filarial mosquito Culex quinquefasciatus. E. urophylla oil was obtained from fresh leaves by water-steam distillation with oil yield 1.08%. E. urophylla oil in this study had no color (clear), has odor (typical eucalyptus), with specific gravity 0.941; refractive index 1.465; miscibility in 70% ethanol 1 : 3; and optical rotation (-) $5.83^{\circ}$. The major compounds of the oil were ${\alpha}$-pinene (11.73%), 1,8-cineole (49.86%), ${\beta}$-ocimene (6.25%), ${\gamma}$-terpinene (9.11%), and ${\alpha}$-terpinyl acetate (7.63%). The result showed the excellent insecticide activity against C. quinquefasciatus. The oil provided larvicidal activity with $LC_{50}$: 80.21 ppm and $LC_{90}$: 210.18 ppm, and repellent activity with $IC_{50}$: 0.82% and $IC_{90}$: 4.88%. The present study showed the effectiveness of E. urophylla as natural insecticide against C. quinquefasciatus, the mosquito vector of filariasis.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.143-143
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• 2022

Precipitation plays an essential role in water resources management and disaster prevention. Therefore, the understanding related to spatiotemporal characteristics of rainfall is necessary. Nowadays, highly accurate precipitation is mainly obtained from gauge observation systems. However, the density of gauge stations is a sparse and uneven distribution in mountainous areas. With the proliferation of technology, satellite-based precipitation sources are becoming increasingly common and can provide rainfall information in regions with complex topography. Nevertheless, satellite-based data is that it still remains uncertain. To overcome the above limitation, this study aims to take the strengthens of machine learning to generate a new reanalysis of precipitation data by fusion of multiple satellite precipitation products (SPPs) with gauge observation data. Several machine learning algorithms (i.e., Random Forest, Support Vector Regression, and Artificial Neural Network) have been adopted. To investigate the robustness of the new reanalysis product, observed data were collected to evaluate the accuracy of the products through Kling-Gupta efficiency (KGE), probability of detection (POD), false alarm rate (FAR), and critical success index (CSI). As a result, the new precipitation generated through the machine learning model showed higher accuracy than original satellite rainfall products, and its spatiotemporal variability was better reflected than others. Thus, reanalysis of satellite precipitation product based on machine learning can be useful source input data for hydrological simulations in ungauged river basins.

• Journal of the Korean Wood Science and Technology
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• v.48 no.1
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• pp.76-85
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• 2020

This study was conducted to analyze the application of boron compounds, methyl methacrylate (MMA), and heat treatment (HT) on changes in the density, moisture content, and flexural properties of samama (Anthocephalus macrophyllus) wood. Samama wood was impregnated with borax (BX) and boric acid (BA) using a pressure method at 5 atm for 4 h. Afterwards, the wood was impregnated with MMA at the same pressure and duration. Finally, the samama wood was given HT at 90 ℃ and 180 ℃. The results indicate that there was a weight gain of 93.4% in the wood impregnated using BA and MMA monomer and HT at 90 ℃. Consequently, the wood's density increased by 82.3%. Increased MOE and MOR percentages of 32.2% and 29.4%, respectively, were also found. HT at 180 ℃ degraded the wood components and MMA, and consequently, the density, MOE, and MOR also decreased. The wood impregnated by BX, BA, and MMA, and subjected to HT also had decreased moisture content (MC). This research recommends that the application of boron (BX, BA) should be combined with an MMA monomer and HT at 90 ℃ as an alternative method to improve samama wood quality. If darker color is preferable, HT should be conducted at 180 ℃.

• Journal of the Korean Wood Science and Technology
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• v.36 no.3
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• pp.47-54
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• 2008

To make up original defects of the wooden materials for decks, and to supply the wooden material for outdoor, we fabricated preservative treated plywood(PTP). Copper azole (CUAZ-1) preservative was treated with a normal full-cell process. Bond Strength of PTP was not affected after the preservative treatment. The anti-fungal efficiency and dimensional stability were obtained from PTP. A little discoloration of the surface was detected, but the dimensional change or peel bonded area off were not observed after accelerated weathering test. Although some strength of PTP was reduced after 17 months of field exposure, the PTP should be applicable for outdoor applications.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.555-564
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• 2019

Biodiesel is produced through the transesterification process in the presence of alcohol and a catalyst that catalyzes the conversion of triglycerides to esters and glycerol compounds. A more optimal product conversion can be achieved using enzymes, such as lipase. Lipase is reported to be produced in osmophilic yeasts due to the low water content in their natural habitats. Wild forest honey is one of the osmophilic natural habitats in Indonesia. However, lipase-producing yeast has not been reported in the Indonesian honey. In this study, we screened the lipase-producing yeasts isolated from wild forest honey collected from Central Sulawesi. The production profile and activity of lipase were determined at different pH values and temperatures. One promising yeast was isolated from the honey, which was identified as Zygosaccharomyces mellis SG 1.2 based on ITS sequence. The maximum lipase production (24.56 ± 1.30 U/mg biomass) was achieved by culturing the strain in a medium containing 2% olive oil as a carbon source at pH 7 and 30℃ for 40 h. The optimum pH and temperature for lipase activity were 6 and 55℃, respectively. The enzyme maintained 80% of its activity upon incubation at 25℃ for 4 h. However, the enzyme activity decreased by more than 50% upon incubation at 35 and 40℃ for 2 h. This is the first study to report the lipase producing capability of Z. mellis. Further studies are needed to optimize the enzyme production.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.12 no.6
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• pp.285-289
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• 2012

In this paper, the farm information system was designed by ubiquitous computing. The irrigation system was set up for growing forest products. Also, the integrated sensing system with the radar sensors would be constructed for sensing the temperature, the humidity and the direction of the wind, ect. And the monitoring programs for workers in the fields were provided for the control and the monitoring the growing conditions of the forest products. Finally the database was constructed for the total monitoring and management system, so the data from sensor system was stored in the database sever for analysing growing environment.

• Journal of Animal Science and Technology
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• v.44 no.1
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• pp.87-94
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• 2002

A comparison of intake, digestibility and nitrogen balance in spotted deer(Cervus nippon) fed forest by-product silage(FBS), arrowroot silage(ARS) and oak leaf hay(OLH) was made to examine the feeding value of forest by-product silage. Dry matter digestibility of ARS was significantly higher(p$<$0.05) than that of OLH while crude protein digestibility was significantly higher(p$<$0.05) in ARS and FBS than in OLH. The digestibility of crude fiber was highest in FBS. Dry matter intake of OLH was significantly higher(p$<$0.05) than that of ARS, and there was no significant difference with FBS. Nitrogen intake was higher in OLH and ARS than in FBS, but there was no significant difference. Fecal nitrogen was highest(p$<$0.05) in OLH and urinary nitrogen was highest(p$<$0.05) in ARS. Retained nitrogen was highest in FBS, however, there was no significant difference among treatments. In Conclusion. FBS was estimated as a useful roughage source for deer, showing high digestibility, dry matter intake and nitrogen utilization.

• Journal of the Korean Wood Science and Technology
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• v.46 no.2
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• pp.155-165
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• 2018

The objective of the research was to evaluate the effect of particle pre-treatment on physical, mechanical, and durability of jatropha fruit hulls (JFH) particleboard. The pre-treatments included were immersing in cold water, hot water, and acetic acid solution. After each treatment, the particles were dried up to 3% moisture content. Urea-formaldehyde (UF) resin was used to fabricate particleboards with board size, thickness and density target of 25 cm by 25 cm, 0.80 cm, and $0.70g/cm^3$, respectively. Board pressed at $130^{\circ}C$ for 10 minutes, and $25kg/cm^2$ pressure. The evaluation of particleboard followed the JIS A 5908-2003. Whilist their resistance to subterranean termite test (mass loss, mortality, antifeedant value and feeding rate) refers to the Indonesian standard (SNI 01.7207-2006). The physical and mechanical properties of particleboards showed that all pre-treatments decreased the pH of particles. Overall, all particle immersing treatments resulted of better physical and mechanical properties of particleboard than those of untreated ones. The acetic acid treatment resulted the best physical and mechanical properties of particleboard. Based on the mass loss of JFH particleboard, hot water and acetic acid treated particleboards were classified into weak resistance to subterranean attack. The other two treatments were classified into very weak resistance. Hot water treated particleboard provided the highest mortality and antifeedant as much as 87.40% and 34.20%, respectively. Based on antifeedant classification, hot water treated particleboards were classified into moderately strong resistance, while other treatments were categorized into weak resistance. The lowest feeding rate value ($45.30{\mu}g/termite/day$) was attained by hot water treatment.