• Journal of the Korean Applied Science and Technology
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• v.29 no.3
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• pp.486-494
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• 2012

Nano-emulsion with phase inversion temperature (PIT) emulsifying system was prepared to use rapeseed oil from originating Jeju in order to apply various cosmetic applications. Natural rape seed oil (NRSO) extraction was extracted using n-hexane as a solvent. NRSO extract showed a light yellowish color of viscous liquid as well as yield was $43{\pm}2.5%$. Acid value was $2.76{\pm}0.5$ and gravity was $0.89{\pm}0.05$. Droplet size of PIT-Yuche-NE with 20wt% of rapeseed oil was 50-120nm (average: $82{\pm}5.8nm$) and zeta potential was -29.5mV. It was thermodynamically good stable emulsion due to $(PEG)_{5-30}$fattyacidether. Some conclusions from the result of characteristic experiment were obtained as follows. First, the anti-oxidative activity was measured by free radical scavenging activity using DPPH (1,1-diphenyl-2-picrylhydrazyl radical). Anti-oxidative activity of PIT-Yuche-NE was $37.2{\pm}6.7%$ on 10mg/mL compared with PIT-Toco-NE (Natural tocopherol nano-emulsion, $28.8{\pm}6.5%$ on 10 mg/mL) and PIT-Nokcha-NE (Green tea extract nano-emulsion, $29.6{\pm}7.2%$ on 10mg/mL). Second, the collagen synthesis activity of PIT-Yuche-NE was $148{\pm}15.2%$ compared with PIT-Toco-NE (Natural tocopherol nano-emulsion, $121{\pm}13.5%$ on 10mg/mL) and PIT-Nokcha-NE (Green tea extract nano-emulsion, $95{\pm}12.7%$ on 10mg/mL). Third, the effectiveness of moisturizing activity of Yuche-CRM with Aramo-TS after 6 hours increase $47{\pm}3.9%$ (*p-value￡0.05, n=7) whereas Both Toco-CRM was $30{\pm}5.2%$ (*p-value￡0.05, n=7) and Nokcha-CRM was $35{\pm}4.5%$. Therefore, Yuche-CRM has higher moisturizing effect than other two creams. Finally, Nano-emulsion stabilizing rapeseed oil using PIT emulsifying system of this study can be used to apply cosmetics industry and pharmaceutical industry.

• Korean Journal of Soil Science and Fertilizer
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• v.49 no.5
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• pp.449-455
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• 2016

'Gamhong' apple cultivar which was bred by National Institute of Horticultural and Herbal Science, has high sugar contents, large types of fruit and mid-season types of cultivar. However, 'Gamhong' apple tree is very sensitive cultivar to bitter pit. Therefore, many farms have not solved the problems on bitter pit to cultivate 'Gamhong' apple tree. This study was carried out to find out the exposed length of rootstocks on the occurrence of bitter pit and fruit quality of 'Gamhong'/M.26 apple tree and seek the ideal cultivation strategy to decrease bitter pit to cultivate it. For this research, ten-years-old 'Gamhong'/M.26 apple trees were used. The difference among the treatments of the exposure of rootstock of RL (5 cm), RM (15 cm) and RH (20 cm) from the soil surface was observed with 4 repetition from 2010 to 2011. Decreased exposure of rootstocks resulted in more vigorous growth, taller height, and greater number of shoots. N and K/Ca of RH was tend to be lower than RM and RL, whereas as the exposure of rootstock decreased, fruit weight and bitter pit increased. Therefore, occurrence of bitter pit in RH was significantly lower than that of RM and RL treatment and fruit weight also decreased. There was no difference on nutrient contents of leaf and the fruit quality by the exposed of rootstock in 'Gamhong' M.26 apple tree. To reduce the occurrence of bitter pit, it may be helpful to keep the optimum exposure of rootstock within 20 cm from the soil surface.

• Journal of the Korean Applied Science and Technology
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• v.37 no.6
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• pp.1738-1751
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• 2020

The skin is divided into three parts: the epidermis, the dermis, and the subcutaneous fat, and the stratum corneum, which is located at the top of the epidermis, acts as a barrier that prevents drug delivery. Nanoemulsions are known to be effective in transdermal delivery of drugs through intercellular lipids because of their unique small particle size. In this study, phase inversion temperature (PIT) nanoemulsion containing α-bisabolol was optimized using response surface methodology (RSM) for effective skin absorption of α-bisabolol. As a preliminary experiment, the 25-2 fractional factorial design method and the 23 full factorial design method were performed. Box-Behnken design was performed based on the results of the factorial design method. The content of surfactant (6.3~12.6%), co-surfactant (5.2~7.8%) and α-bisabolol (0.5~5.0%) were used as factors, and the dependent variable was the particle size of the nanoemulsion. PIT nanoemulsion optimization was performed according to the RSM results, and as a result, the optimal nanoemulsion formulation conditions were predicted to be 10.4% surfactant content, 6.3% co-surfactant content, and 5.0% α-bisabolol content. As a result of the skin absorption test, the final skin absorption rate of the PIT nanoemulsion was 35.11±1.01%, and the final skin absorption rate of the general emulsion as a control was 28.25±1.69%, confirming that the skin absorption rate of the PIT nanoemulsion was better.

• Steel and Composite Structures
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• v.46 no.3
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• pp.385-401
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• 2023

Steel is becoming increasingly popular due to its high strength, excellent ductility, great assembly performance, and recyclability. In reality, steel structures serving for a long time in atmospheric, industrial, and marine environments inevitably suffer from corrosion, which significantly decreases the durability and the service life with the exposure time. For the mechanical properties of corroded steel, experimental studies are mainly conducted. The existing numerical analyses only evaluate the mechanical properties based on corroded morphology at the isolated time-in-point, ignoring that this morphology varies continuously with corrosion time. To solve this problem, the relationships between pit depth expectation, standard deviation, and corrosion time are initially constructed based on a large amount of wet-dry cyclic accelerated test data. Successively, based on that, an in-situ pitting evolution method for evaluating the residual tensile strength of corroded steel is proposed. To verify the method, 20 repeated simulations of mass loss rates and mechanical properties are adopted against the test results. Then, numerical analyses are conducted on 135 models of corrosion pits with different aspect ratios and uneven corrosion degree on two corroded surfaces. Results show that the power function with exponents of 1.483 and 1.091 can well describe the increase in pit depth expectation and standard deviation with corrosion time, respectively. The effect of the commonly used pit aspect ratios of 0.10-0.25 on yield strength and ultimate strength is negligible. Besides, pit number ratio α equating to 0.6 is the critical value for the strength degradation. When α is less than 0.6, the pit number increases with α, accelerating the degradation of strength. Otherwise, the strength degradation is weakened. In addition, a power function model is adopted to characterize the degradation of yield strength and ultimate strength with corrosion time, which is revised by initial steel plate thickness.

• Journal of Forest and Environmental Science
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• v.8 no.1
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• pp.51-66
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• 1992

This study was carried out to investigate the micromorphology of vessel wall sculpture such as shape of perforation plate, perforation rim, steepness of perforation plate, occurrence of vestured pit, warty layer and ray-vessel pitting on 13 species of Fagaceae in Korea. The results were summarized as follows ; 1. In the species examined, all sample species except Fagus crenata var. multinervis have simple perforation plate. But Fagus crenata var. multinervis has simple and scalariform perforation plate (it was called to combination perforation plate) in a tree stem. 2. The shapes of perforation rim could be classified into five types; Type A without tail, Type B with small tail on both sides, Type C with long tail on both sides, Type D with tail only one side and Type E with the very short interval between perforations. Among five types, Type Band C have higer frequency of distribution than the others. 3. The steepness of perforation plate measured was about 20 degree on pore zone and 43 degree on outside parts of pore zone. 4. Species with vestured pit were Q. aliena, Q, dentata, Q. variabilis, Fagus crenata var. multinervis, Castanopsis cuspidata var sieboldii, Q. acuta, Q. stenophylla, and Q. glauca. But the extent of vesturing was very slight and vestured pits were observed mainly in ray-vessel pit of some vessel elements. 5. Species with warty layer on the inner surface wall of all vessel elements were Q. acuta, Q. stenophylla, Q. glauca, Fagus crenata var. multinervis and species with warty layer of some vessel elements were Q. aliena, Q, dentata, Q. variabilis, Castanopsis cuspidata var. sieboldii. 6. Species with palisade ray-vessel pit were Q. acuta, Q. stenophylla, Q. glauca, Castanea crenata, Castanea bungeana, Q. aliena, Q. serrata, Q. mongolica, and species with scalariform ray-vessel pit was Fagus crenata var. multinervis and species with oval ray-vessel pit were Q, dentata, Castanopsis cuspidata var sieboldii.

• Animal Bioscience
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• v.35 no.12
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• pp.1977-1985
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• 2022

Objective: This study was conducted to determine the seasonal characteristics of odorous material emissions from a swine finishing barn equipped with a continuous pit recirculation system (CPRS) using aerobically treated manure. Methods: The CPRS consists of an aerobic manure treatment process and a pit recirculation system, where the solid fraction is separated and composted. The aerated liquid fraction (290.0%±21.0% per day of total stored pig slurry) is continuously recirculated to the top of the slurry in the pit. Four confinement pig barns in three piggery farms were used: two were equipped with CPRS, and the other two operated a slurry pit under the slatted floor across all seasons. Results: The indoor, exhaust, and outside odor intensities were significantly lower in the CPRS group than in the control group (p<0.001). In the CPRS group, the odor intensity outside was significantly lower in the fall than in the other seasons (p = 0.015). In the indoor atmosphere, the temperature and CO₂, NH₃, and H₂S contents of the CPRS group were significantly lower than those of the control group (p<0.05). In the CPRS group, indoor temperature did not significantly change in the spring, summer, and fall seasons and was significantly lower in the winter (p = 0.002). NH₃, H₂S, methyl mercaptan, dimethyl disulfide, trimethylamine, phenol, indole, and skatole levels were significantly lower in the CPRS group than in the control group (p<0.05). There were significant seasonal differences on the odorous material in both the control and CPRS groups (p<0.05), but the pattern was not clear across seasons. Conclusion: The CPRS can reduce the indoor temperature in the summer to a level similar to that in the spring and fall seasons. The CPRS with aerated liquid manure is expected to reduce and maintain malodorous emissions within acceptable limits in swine facilities.

• Journal of Ocean Engineering and Technology
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• v.16 no.6
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• pp.37-43
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• 2002

The calculation of earthwork plays a major role in the plan or design phase of many civil engineering projects, such as seashore reclamation; and thus, it has become very important to improve upon its accuracy. There have been common drawbacks to earlier methods of ground profiling, such as dialing with sharp corners or the grid points of any tow straight lines. In this paper, we prepose an algorithm for finding a terrain surface using the natural boundary conditions and the both direction spline method, which interpolates the given three-dimensional data by using spline. As a result of this study, the algorithm of the proposed two methods to estimate pit excavation volume should provide a better accuracy than Spot height, Chambers, Chen, or Lin method. Also, the mathematical model mentioned offers maximum accuracy in estimating the volume of a pit excavation.

• Journal of Korean society of Dental Hygiene
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• v.20 no.4
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• pp.535-543
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• 2020

Objectives: The aim of this study was to investigated the surface roughness and change in the amount of adhesion of Streptococcus mutans to the commercial pit and fissure sealant containing cerium oxide nano particles(CNPs). Methods: The CNPs was incorporated into a commercial pit and fissure sealant at 0-4.0 wt%. Disk Specimens (ϕ 10 mm × 2 mm) were prepared by light polymerization the front and back for 40s. Average surface roughness was measured and Streptococcus mutans adhesion was observed under confocal laser scanning microscopy (CLSM) after 24 hour. Data were statistically analyzed by one-way ANOVA and Tukey HSD^a post-hoc test. Results: Difference of the surface roughness(Ra) between groups was not statistically significant in both non CNPs group and CNPs group(p>0.05). In CNPs group, the amount of S. mutans adhesion was significantly different between control group and decreased in order of CNPs 4.0, CNPs 0.5, CNPs 1.0 and CNPs 2.0(p<0.05). Conclusions: Within the limitation of this study, these aspects of oral bacteria performances suggest potential usefulness of the CNPs incorporation, especially CNPs 1% and 2%, in pit and fissure sealant for inducing antibacterial effect.

• Journal of the Korean Wood Science and Technology
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• v.21 no.4
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• pp.60-63
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• 1993

In the present paper, we discribed distributions patterns of pits on the tracheids of Pinus koraiensis. The number of bordered pits on a tracheid is more numerous than that of cross-field pittings. And they appeared different in the number depending on the shape and size of tracheids. Both pit and cross-field pitting on a tracheid is fewer in number near the pith. The number of bordered pits on the tracheid increased rapidly from pith toward cambial zone but that of cross-field pittings increased gradually. The number of bordered pit and corss-field pitting is more frequent in the first-formed tracheid, and the number of bordered pit decreased rapidly from earlywood to latewood but that of corss-field pittings decreased gradually. Bordered pits on a tracheid are more numerous at the end of tracheids and cross-field pittings occur more frequently in the center part of a tracheid.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2003.05a
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• pp.311-314
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• 2003

Superconduction materials possess electrical/electronic and magnetic properties. Because superconduction materials is a ceramic powder, that can not be produced singlehandedly. So Ag sheathed Bi-2223 wire was produced by drawing process using powder-in-tube(PIT) method This superconductor has many difficulties to produce. The main difficulty is that the mechanical properties of the ceramic powder are very different from those of the Ag sheath. Actually, the fabrication of Ag sheathed Bi-2223 superconductor by PIT tends to lead to non-uniformity in the core thickness during drawing process. That is so called “Sausaging”. This study analyzed a sausaging using the finite-element method. Also, Effects of drawing process parameters on a sausaging has been carried out using finite element method. Finally, A way to prevent a sausaging has been discussed.