• Journal of the Korean Wood Science and Technology
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• v.35 no.4
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• pp.14-20
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• 2007

The properties of the wood pellets from damaged wood by forest fire and sound woods were investigated. Oven-dry densities of pellets made from sound wood and the damaged wood of Pinus densiflora were 0.93~0.94 and 0.86~0.88, respectively. Compressive strength of the pellets from the woods was ranged from 145 to $168kgf/cm^2$, and there was little difference between the sound wood and the damaged wood of P. densiflora. Ash content for the sound wood and the damaged wood of Pinus densiflora were 0.32~0.37% and 0.25~0.35%, respectively, and calorific values of each pellet were ranged from 18 to 19 MJ/kg. The result of elemental analysis in carbon. hydrogen and oxygen showed 45.8~48.8%, 6.2~6.5% and 46.5~48.0%, respectively. Consequently, there seem no significant difference in the properties between damaged and sound wood pellets.

• Journal of the Korean earth science society
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• v.26 no.3
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• pp.253-267
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• 2005

Seasonal and spatial variations of tidal flat sediments were studied in Yeoja Bay. Results of the yearly observation of tidal flat transect lines indicated that the monthly change of grain size composition was not distinct from each tidal flat transect line, but it was quite clear that clay covered $40\~70\%$ of the sediment composition. Clay composed most highest in the northern part of the bay, and lowest in the western. As clay content increased, water and organic matter showed a tendency of increase, while the mean grain size was fixed per clay amount. Shear strength came out as 0 kPa as a whole. Seasonal variations of clay contents in each tidal flat were higher in winter and spring, but lower in summer and autumn. Thefine sediments were likely to be accumulated in the winter and spring. The average accumulation rate of each tidal flat was $-14.62\~38.57mm{\cdot}yr^{-1}$. The numbers showed $32.13mm{\cdot}yr^{-1}$ in the northern, $-14.62mm{\cdot}yr^{-1}$in the western, and $6.46mm{\cdot}yr^{-1}$ in the eastern part. During the coarse of this study sediment accumulation rates indicated that the sediments deposited continuously in the northern part of tidal flat, whereas erosion occurred in the western part. However, there was no distinct change in the eastern part. It was due to the clockwise lateral circulation in Yeoja Bay. Seasonally, sedimentation happened during the dry season (winter and spring) and erosion during the wet season (summer and autumn).

• Journal of the Korean Geosynthetics Society
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• v.13 no.3
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• pp.21-30
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• 2014

In this study, the applicability of the lightweight dynamic cone penetrometer in the domestic slope site was investigated using the weathered granite soil sampled form the Namwon slope site. And then, the lightweight dynamic cone penetration tests according to the change in the degree of compaction and water content were performed and it was analyzed with the correlations between the degree of compaction, the void ratio, the degree of saturation and the value of cone resistance. From the laboratory test results, the cone penetration resistance was rapidly increased in the dry side of the optimum moisture content, and it was largely decreased in the wet side of the optimum moisture content. Moreover, when the degree of compaction and the degree of saturation are large, the cone resistance is increased linearly. And a high correlativity was shown between water content, void ratio, the degree of saturation and the cone resistance. From these results, it is judged that the lightweight dynamic cone penetrometer can be applied to the investigation on the site slope.

• Journal of the Korea Organic Resources Recycling Association
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• v.25 no.2
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• pp.69-76
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• 2017

In the Korea, 80 percent of livestock manure were converted into compost and used as organic fertilizers. The livestock manure compost has two types of powder and pellet type (ID= 5~10 mm). The aim of this study was to investigate the properties of two types of cow manure compost pellet (cylinder and sphere type). Nitrogen concentrations of cylinder type and sphere type of compost pellets were 1.23 and 1.24%, respectively. There were similar with nitrogen concentration of cylinder and sphere types of compost pellets. As a result of analyzing the effect of granulation processing, it was found that the moisture content of the raw material was the most influential factor in the granulation processing in both of the processing types of the screw pressing method and the rotating cylinder method. When the cylinder and sphere types of compost pellets were dry to 20% of moisture content, the specific gravities of these compost pellets were 1.38 and 1.13, respectively. The compressive strength of cylinder type pellet and sphere type pellet were 27.6 and $11.3kg/cm^2$, respectively.

• Proceedings of the Korea Society of Poultry Science Conference
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• 2001.11a
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• pp.24-39
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• 2001

These experiments were conducted to evaluate the nutritional and feeding value of red pepper seed oil meal (RPSOM) as local vegetable protein ingredients for poultry feeding. In the first experiment, nutritional values of RPSOM were evaluated by analyzing chemical compositions and determining true metabolizable energy (TME), nitrogen corrected TME (TMEn) and true available amino acid (TAAA) contents. According to the chemical analysis, RPSOM contained 22.50％ of crude protein, 4.75％ of ether extract, 27.70％ of crude fiber, 0.34 mg／g of capsaicin and 49.97 ppm of xanthophylls. The values of TME and TMEn determined by force-feeding 16 roosters (ISA-Brown) were 1.73 kcal／g and 1.63 kcal／g on dry matter basis, respectively. The average TAAA value of 16 amino acids measured by the force－feeding technique was 81.70％. These values were used for formulating experimental diets containing various levels of RPSOM for broiler chicks and laying hens. Two feeding trials were made to investigate the effects of dietary incorporation of RPSOM into chicken feed performances of broiler chicks and laying hens. In the broiler feeding (Exp. 2), a total of two hundred twenty-five, 4 wk old male broiler chicks (Ross) were randomly divided into 9 groups of 25 birds each and assigned to three experimental diets containing 0, 5 and 10% RPSOM. The birds were fed ad libitum the diets for 3 wk and feed intake, weight gain and feed conversion rate were determined. At the end of the feeding, the blood levels of glutamate oxaloacetate transaminase (GOT), gamma glutamyl transpeptidase (GGT), blood urea nitrogen (BUN) and cholesterol, and the body and fatty acid compositions of leg muscle were measured. No significant differences were observed in weight gain, feed intake, feed conversion rate, body composition, serum levels of GOT, GGT and BUN among the treatments. However, blood cholesterol level was lower (P＜0.05) in 10% RPSOM diet group than those in the other. The dietary RPSOM at 5 and 10% levels increased the content of linoleic acid (P＜0.05) in leg muscle compared to that of control group. The results indicate that RPSOM can be used for broiler feed up to 10% without any significant negative effects on broiler performance. In the layer feeding (Exp. 3), the effects of dietary RPSOM on the performances of laying hen were investigated by feeding ninety 45 wk old laying hens (ISA-Brown) with experimental diets containing 0, 5 and 10% RPSOM for 4 wk (30 birds per treatment). Measurements were made on egg production rate, egg weight, feed intake, Haugh unit, egg shell strength which was higher (P＜0.05) in layers fed 10% RPSOM diet compared to those fed 0 and 5% RPSOM diets. Thus, it can be concluded that RPSOM can be included into laying hen feed up to 10% without any harmful effects.

• Plant Biotechnology Reports
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• v.2 no.2
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• pp.163-169
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• 2008

Roots of Ophiorrhiza prostrata D. Don serve as a rich source of camptothecin (CPT), an anticancer drug. Because of the large-scale collection of its roots, the plant has become a threatened species. The present study accomplishes the induction of adventitious roots as a means for the production of CPT as well as for the large-scale propagation of this anticancer drug plant using leaf and internode explants. The biomass yield and CPT content of adventitious roots induced from different explants were compared to roots developed on ex vitro rooted stem cuttings. Adventitious roots were produced on half-strength Murashige and Skoog (MS) medium supplemented with $10.74{\mu}M$ ${\alpha}-naphthaleneacetic$ acid and $2.32{\mu}M$ kinetin at mean fresh weights of 0.753, 0.739 and 0.748 g roots from leaf, internode and shoot, respectively. CPT yield from in vitro derived roots after 50, 80 and 120 days of incubation (0.028, 0.06 and 0.1% dry weight, respectively) was not significantly different from those harvested at the same age from ex vitro rooted (0.03, 0.06 and 0.13%, respectively) stem cuttings. CPT from subcultured roots derived from solid (0.08%) medium was lower than from suspension culture medium (0.12%). Subsequent cultures of the adventitious roots showed a stable production of CPT (0.16%). The yield of CPT from 360-day-old plant-derived roots was 0.19%. Elicitation using methyl jasmonate and acetyl salicylic acid exhibited no enhancement in CPT yield. In vitro propagation through direct shoot regeneration was achieved from the adventitious roots upon transfer to MS medium with $8.87{\mu}M$ $N^6-benzyladenine$ (BA) and $2.46{\mu}M$ indole-3-butyric acid (IBA) with a mean of 21.2 shoots per culture in 50 days. The shoots upon subculture on medium having the same level of BA and IBA underwent rapid proliferation. The shoots transferred to field conditions after in vitro rooting exhibited 95% survival. Adventitious root induction, from leaf and internode explants, enables the feasible production of CPT as well as the large-scale rapid propagation of this species which can safeguard it from extinction.

• The Journal of Engineering Geology
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• v.17 no.3
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• pp.425-434
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• 2007

In this paper, the stability standards of slopes reclaimed by soils mixed with stone dust were proposed to manage the stone dust as recovery soils. First of all, the mixed ratio between stone dust and natural soil is classified into 5 groups, and a series of soil test was performed in each group. As the results of tests, the shear strength and the maximum dry unit weight were increased in decrease of the mixed ratio of stone dust. On the basis of the investigation to the safety factor standards of embankment slopes in and outside the country, a slope stability rank of slopes reclaimed by mixed soils were divided into 3 stages such as unstable stage, attention stage and stable stage. The slope angle, the slope height and the mixed ratio with stone dust were proposed by the result of stability analysis of slopes reclaimed by mixed soils. As the result of slope stability analysis, the slope angle of 1 : 1.8 at the reclaimed slope should be constructed in case of the slope height of 10 m. Also, the slope angle of 1 : 1.8 and the mixed ratio of stone dust less than 50% should be constructed in case of the slope height of 15 m. The analysis result of reclaimed slope constructed inside the quarry is similar to that of reclaimed slope constructed on the open ground in same conditions of the slope angle, the slope height and the mixed ratio with stone dust. The proposed stability standards of slopes reclaimed by soils mixed with stone dust can be used practically at the quarrying site.

• Journal of Dental Rehabilitation and Applied Science
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• v.25 no.2
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• pp.157-169
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• 2009

The aim of this study was to evaluate effect of implant abutment screw coating treatment on joint stability, investigating mechanical properties of these. For this study used $ExFeel^{(R)}$ external hexed implant system and $15mm{\times}1mm$ discs. Experimental group was $1{\mu}m$ TiN, TiCN, TiC coated abutment screws and discs. To know mechanical property, i evaluated adhesion strength, surface hardness, using disc, corrosion test using screw. The results were as follows : rotation angle of coated screws increased than that of non-coated screw because of lower friction coefficient, especially TiC coated screw group had the largest value, but removal torque decreased in all coated screws (p<0.05). Torque loss before and after fatigue test was the smallest in TiC-coated screws, and the largest in non-coated screws (p<0.05), and there was no statistically significant difference between dry condition and wet condition of screws because of higher surface hardness and lower friction coefficient. From the above results, TiN, TiCN, TiC coating group had high abrasion resistance, especially TiC coated group which had low torque-consuming, high rotation angle as low friction coefficient will be considered to influence on implant abutment screw joint stability positively.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.4
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• pp.763-770
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• 1997

The air abrasive technique is a non-mechanical method by which teeth are treated before restoration and stains and calculi are removed from tooth surfaces using the kinetic energy of small particles. The air abrasive technique in dentistry was first introduced in the 1950's with as instrument called 'Airdent'. But, as the main restorative materials of the period were amalgam and gold, and the instrument's inability to control the flow of particles caused the particles to be spread throughout the clinics, widespread use was not possible. In the 1990's, as these techincal problems were solved and more interest in new restorative materials rose in an effort to preserve sound tooth structure, new developements took place in instruments related to the air abrasive technique. The air abrasive technique produces less pressure, vibration and heat that might cause patient discomfort and facilitates the preservation of sound tooth structure. It also reduces the need for anesthesia and is less harmful to the pulp. Other advantages include increase in dentin bonding strength of composite resin, lower possibility of saliva contamination and maintenance of a dry field. But there is not direct contact between the nozzle and the tooth, the operator cannot use his or her tactile sense and must rely solely upon visual input. Other disadvantages are: the tooth preparation depends on the operator's ability; alpha-alumina particles, after bouncing off the tooth surface, cause damage to dental mirrors; the equipment is expensive and takes up a certain amount of space in the clinic. The author conducted case report using the air abrasive technique on patient visiting the Department of Pediatric Dentistry at Seoul National University Dental Hospital and arrived at the following conclusions. 1. The tooth preparation capability of different air abrasive devices varied widely among manufacturers. 2. It was more effective in treating early caries lesions and stains compared to lesions where caries had already progressed to produce soft dentin. 3. The cold stream and noise caused by the evacuation system was a major cause of discomfort to pediatric patients. 4. As there is no direct contact with tooth surface when using the air abrasive technique for tooth preparation, considerable experience and skill is required for proper tooth preparation.

• Journal of Adhesion and Interface
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• v.12 no.4
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• pp.111-116
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• 2011

The characteristics of natural resin, sap of the lacquer tree were examined as an adhesive for the ceramic conservation since it has such outstanding properties like corrosion resistance against acid and alkali, heat-resistance, waterproof, antiseptic and protection against insects. In order to utilize raw lacquer as an adhesive not under the hardening conditions of lacquer like high humidity (RH 75 to 85%) and high temperature (120 to $170^{\circ}C$), but under normal condition, isinglass and animal glue were added to raw lacquer at certain ratio. In addition, the viscosity and the drying time were measured and their possibilities of application were also investigated through measurement of tensile and adhesive strength. As a result of experiment, it was possible to dry at room temperature and RH $50{\pm}5%$ to mix with raw lacquer and glue, and the drying time of sample with animal glue was faster than that of isinglass. Furthermore, the adhesion of sample with glue was increased more than raw lacquer. It seems to be possible to use the environmental friendly traditional adhesive for the ceramic conservation and restoration, if there are studies or examinations of safety of applications on objects and weathering resistance.