• 한국환경복원기술학회지
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• 제12권3호
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• pp.98-105
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• 2009

The objective of this study is to develop numerical simulation model for analysing the wind speed reduction effect by coastal forest belts. The horizontally homogeneous turbulent flow equations, which are derived from the Reynolds-averaged Navier-Stokes method, both above the tree canopy and within the canopy were first formulated, and a first-order closure scheme with the capability of accounting the bulk momentum transport term within the canopy was employed. The averaged equations were solved numerically by finite difference method, FTCS (forward time centered space) scheme. The proposed model was also used to numerically investigate the effects of structural characteristic of forest belt on the wind speed. The effects of maximum leaf area density were evaluated, with the leaf area density of $1.0m^2/m^3$, $2.0m^2/m^3$, $3.0m^2/m^3$, and $4.0m^2/m^3$. Vertical distributions of leaf area, both uniform and varied distribution with a height, were also considered. A comparison of wind profile indicated that there was in good agreements between simulated and measured wind speed. Also, the results showed horizontal wind speed decreased under a height of the tree with increasing maximum leaf area density. In conclusion, in applications where computational efficiency and simplicity are desirable, the proposed numerical model has of great capability to determine the vertical turbulent momentum transport and wind profile in the costal forest belt.

• The Korean Journal of Ecology
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• 제19권4호
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• pp.321-328
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• 1996

The profile and concentration of monoterpene metabolites in the leaf and stem of Artemisia princeps var. orientalis were quantified, and seasonal variation in monoterpenes of Artemisia plant was investigated. Samples were taken from five sites at the campus of Kyungnam University during maturing season. Monoterpenes in leaf and stem were analyzed using gas chromatography-mass spectrometry (GC-MS). The major constituents of A. princeps var. orientalis in both the leaf and stem were 21 monoterpenes.$ {\alpha}-pinene,\;{\beta}-pinene,\;{\beta}-myrcene$, dl-limonene, naphthalene and unknown monoterpenes with 5.49 and 16.27 of retenstion time were present in high concentrations of compounds identified on the leaf and stem of A. princeps var. orientalis. The cmounts of total monoterpenes of leaf were from two to five times higher than stem and rapidly decreased with the time, while that of stem was constnat except early spring. Most of the high percentage of monoterpenes in the leaf were those with later retention time. These results indicated that monoterpenes yields are considered to be more variable than monoterpene composition in responding to the time in both the leaf and stem.

• 한국식품영양학회지
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• 제29권3호
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• pp.411-419
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• 2016

In this study, we determined the effect of the mulberry leaf powder on blood lipid metabolism and liver function improvement of mice fed a high fat diet. The mulberry leaf showed a moisture content of $10.74{\pm}0.56%$, ash $9.67{\pm}0.56%$, crude protein $25.24{\pm}1.02%$, and crude fat $2.66{\pm}0.08%$. In the group with high fat diet supplemented with mulberry leaf powder, serum low-density lipoprotein (LDL-cholesterol) and total cholesterol levels were significantly lower (p<0.05); also, serum phospholipid and aspartate amino transferase (AST) levels were significantly lower (p<0.05). Serum insulin and leptin levels were high in mice fed a high fat diet; however, addition of mulberry leaf powder 10% in the diet had no significant effect on blood insulin and leptin control. The results of the study suggested that various plant sterols in mulberry leaf improve lipid metabolism and liver function in ICR-mice.

• Membrane and Water Treatment
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• 제7권5호
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• pp.403-416
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• 2016

The possibility of using carica papaya leaf powder for removal of copper from wastewater as a low cost adsorbent was explored. Different parameters that affect the adsorption process like initial concentration of metal ion, time of contact, adsorbent quantity and pH were evaluated and the outcome of the study was tested using adsorption isotherm models. A maximum of 90%-94.1% copper removal was possible from wastewater having low concentration of the metal using papaya leaf powder under optimum conditions by conducting experimental studies. The biosorption of copper ion was influenced by pH and outcome of experimental results indicate the optimum pH as 7.0 for maximum copper removal. Copper distribution between the solid and liquid phases in batch studies was described by isotherms like Langmuir adsorption and Freundlich models. The adsorption process was better represented by the Freundlich isotherm model. The maximum adsorption capacity of copper was measured to be 24.51 mg/g through the Langmuir model. Pseudo-second order rate equation was better suited for the adsorption process. A dynamic mode study was also conducted to analyse the ability of papaya leaf powder to remove copper (II) ions from aqueous solution and the breakthrough curve was described by an S profile. Present study revealed that papaya leaf powder can be used for the removal of copper from the wastewater and low cost water treatment techniques can be developed using this adsorbent.

• 한국식품영양학회지
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• 제30권6호
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• pp.1191-1198
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• 2017

This study aimed to evaluate the utilization of the top of a low intake of root, through the analysis of the antioxidant activity of the powder of hydroponic-cultured ginseng. Quality characteristics and antioxidant activity were compared and analyzed with Korea's traditional dessert Gaeseong-Juak, which is made of the powder of hydroponic-cultured ginseng's leaf by adjusting the added volume. DPPH radical scavenging activity of the hydroponic-cultured ginseng by the part powder was in the following order: highly stem, leaf and root. It was measured as 67.9%, 42.9%, and 25.9% at the 1 mg/m level. Gaeseong-Juak was prepared by adding hydroponic-cultured ginseng leaf powder at 0%, 0.3%, 0.6%, and 0.9% of the rice powder. As the content of hydroponic-cultured ginseng leaf powder increased, moisture content, L-value, and a-value were significantly decreased, while the b-value was significantly increased. The texture profile analysis of Gaeseong-Juak was not significantly different among the samples. In the sensory test, the sample containing 0.6% hydroponic-cultured ginseng leaf powder achieved good scores. The DPPH radical scavenging activity of Gaeseong-Juak was significantly increased, as the addition level increased, compared to the original. Based on the above results, hydroponic-cultured ginseng leaf was verified to be a possible natural antioxidant. It can increase food's nutritional values and possibilities when made of hydroponic-cultured ginseng, using leaf which is added to the traditional dessert Gaeseong-Juak.

• 동아시아식생활학회지
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• 제21권3호
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• pp.367-374
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• 2011

The purpose of this study was to determine the optimum condition for producing tea leaf Jeung-pyun that does not contain added parched tea leafs (0, 0.5, 1, 1.5, and 2%) while producing Jeung-pyun that has a variety of functional ingredients and to investigate the possibility of making practical application of tea leafs. Moisture contents were 56 ~66% and there were no significant differences among the samples. The pH of Jeung-pyun samples was 5.65~5.74. The L-value decreased as the amount of added tea leaf increased, and the a-value was low in the group made with added tea leafs. The b-value was high in the 1% added group and had a tendency to increase vs the control group as amount of added tea leaf increased. In the groups with added tea leaf the volume was evaluated as being higher in the order of 1>1.5>2%. The specific volume of the group with added tea leaf was evaluated as being higher in the order of 1>1.5>2%. Sensory characteristics of the group with added tea leaf were evaluated as being high. For characteristics of cell uniformity, rice wine flavor, and sweetness, the control group was evaluated as being high, and for characteristics of color, moistness, and softness the 1% added group was evaluated as high. Astringency was evaluated as being high in the 2% added group. Texture profile analysis was conducted after samples were maintained in an incubator at $20^{\circ}C$ for 0, 1, 3, 5, and 7 days. Characteristics for hardness, gumminess, chewiness tended to increase with longer periods of storage. Characteristics for cohesiveness, springiness tended to decrease as the storage period increased. As determined by this study, addition of 1% tea leaf was the most favorable method for making use of tea leafs the production of Jeung-pyun and a potentiality for the use of tea leafs in food was discorvered.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2000년도 제32회 추계학술대회 정기총회
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• pp.177-185
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• 2000

The characteristics of multi-leaf feil bearing are investigated. The Foil bearing is preloaded and has several leaf foils modeled by curved beams. An analysis of the air foil bearing was performed, considering effects of foil deflection and compressible lubrication equation simultaneously. A parametric study shows that the number of foils significantly affect the static characteristics of air foil bearings and describes what the minimum film thickness means. The results include pressure profile, load capacity, dimensionless torque and minimum film thickness in the foil bearing.

• 한국식품조리과학회지
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• 제27권6호
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• pp.763-772
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• 2011

This study evaluated the antioxidative activity and quality characteristics of Sulgidduk (traditional rice cakes) prepared with ramie leaf powder, in order to measure the antioxidative activity of ramie leaves, which are a potentially useful antioxidant food. Antioxidant activities were measured by total phenolic contents, the scavenging activities of DPPH radicals and ABTS+ radicals, and the reducing power. The total phenolic content of freeze dried ramie leaves was estimated at $58.70{\pm}11.42mg$ GAE/g. The $IC_{50}$ values for DPPH radicals and the ABTS+ radical scavenging activity of the ramie leaves were $23.76{\pm}1.41ug/mL$ and $174.82{\pm}6.4ug/mL$, respectively. The leaves also showed a high reducing power of $1.1057{\pm}0.03$ (O.D). To increase the utilizability of ramie leaf, we made Sulgidduk with added ramie leaf powder. Re-grading the quality characteristics of the altered Sulgidduk, the 3% and 5% addition levels most satisfied texture profile analysis and sensory evaluation. The antioxidative effect of the Sulgidduk significantly increased as the addition level increased, compared to the original Sulgidduk. In term of DPPH radical scavenging activity, the 5% or more addition level Sulgidduk showed an antioxdative effect increase of more than 50%. At the 3% or higher addition level, there was higher antioxidant activity than in the positive control group, which included vitamin C and BHT additions. We thus concluded that Sulgidduk with added ramie leaf power can be manufactured as a food that can satisfy sensory preferences as well as boosting antioxidant activity, at both the 3% and 5% addition level.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.90-93
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• 2003

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a circle leaf spring mechanism and a capacitive-type sensor. The, contact probe is attached on the z-axis during measurement while aspheric object are supported on the diamond turning machine(DTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of on-machine measurement system in this investigation is capable of providing a repeatability of 10 nanometers with a $\pm$20 uncertainty of 200nmPv.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 추계학술대회 논문집
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• pp.391-395
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• 2002

This paper described about the ultra-precision profile measurement of aspheric surfaces using contact probing technique. A contact probe has been designed as a sensing device to obtain measuring resolutions in nanometer regime utilizing a leaf spring mechanism and a capacitive-type sensor. The contact probe is attached on the z-axis during measurement while aspheric objects are supported on the single point diamond turning machine(SPDTM). The machine xz-axis motions are monitored by a set of two orthogonal plane mirror type laser interferometers. Experimental results show that the contact probing technique developed of On-machine Measurement System in this investigation is capable of providing a repeatability of 20 nanometers with a $\pm$20 uncertainty of 300 nanometers.