• Journal of Life Science
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• v.10 no.3
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• pp.273-278
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• 2000

The chemical compositions as amino acids, minerals, fatty acids, and total polyphenolic compounds of the seeds of leek (Allium tuberusum) were analyzed. The antioxidative activity of water soluble extract from leek seeds was also tested in DPPH ($\alpha$, $\alpha$ - diphenyl-$\beta$ -picrylhydrazyl) method. The chemical compositions of leek seeds were moisture 4.4%, curde protein 25.7%, crude fat 16.6%, and crude ash 2.9%. Major amino acid compositions were proline 11 g, glutamic acid 4.9 g, arginine 2.1g, aspartic acid 1.6g, leucine 1.3g, valine 1.2 g, and methionine 1.1 g as per 100g. Mineral contents were K 215 ppm, Ca 142 ppm, Fe 124 ppm, and Mg 100 ppm. Major fatty acid compositions were linoleic acid 71.9%, oleic acid 12.7%, palmitic acid 8.6%, and stearic acid 1.4%. The changes of contents in polyphenolic compound from leek seeds caused by heat treatment were also listed in the following order; $20^{\circ}C$(364mg/100g), $40^{\circ}C$(462 mg/100g), and $60^{\circ}C$(551 mg/100g). Antioxidative activity as electron donating ability showed in the following order; 0.05% BHT(butylated hydroxytoluene)(45.6%)>0.05% water-extract(31.3%)>0.1% water extract(30.3%). On the basis of chemical analysis, the leek seedsshowed to have relatively high contents of nutrients as amino acids, minerals, fatty acids.

• Tunnel and Underground Space
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• v.20 no.4
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• pp.267-276
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• 2010

In modern rock engineering practice, fully grouted rock bolting is actively employed as a major supporting system, so that understanding the behavior of fully grouted rock bolts is essential for the precise design of rock bolting. Despite its importance, the supporting mechanism of rock bolts has not been fully understood yet. Since most of existing analytical models for rock bolts were developed by drastically simplifying their boundary conditions, they are not suitable for the bolts of in-situ condition. In this study, 3-D elastic FE analysis of fully grouted rock bolts has been conducted to provide insight into the supporting mechanism of the bolt. The distribution of shear and axial stresses along the bolt are investigated with the consideration of different boundary conditions including three different displacement boundary conditions at the bolt head, the presence of intersecting rock joints, and the variation of elastic modulus of adjacent rock. The numerical result reveals that installation of the faceplate at the bolt head plays an important role in mobilizing the supporting action and enhancing the supporting capabilities of the fully grouted rock bolts.

• Journal of Conservation Science
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• v.32 no.3
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• pp.377-384
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• 2016

There are physical and chemical method for removement of a lacquered layer existing on the surface when gilding an iron Buddha, these caused environmental pollution by surface degradation and is very noxious for conservation scientist's health. Thus, on this study, we conducted a lacquered layer removement experiments using Nd:YAG Laser which is contactless and eco-friendly. Specimens were made by polishing $5{\times}5$ size of iron(99.9%) specimens surfaces evenly and by differing of number of coating of unrefined lacquer, so there were thickness differences of $10{\mu}m$, $20{\mu}m$, and $30{\mu}m$. The laser machine used in this study was Nd:YAG Laser, and we used two wavelength modes; 1064 nm(160~180 mJ) for infrared light region and 532 nm(50~350 mJ) for ultraviolet light region. The experiment done by investigating the transition of specimens' surfaces with laser wavelength, energy, and numbers of investigation. The remain amount of lacquered layer surfaces before/after laser irradiation was investigated by stereoscopic microscope, observation by SEM, Non-contact Surface Roughness Measurement Device, and FT-IR etc. As a result of each analysis, we could verify the thickness of $10{\mu}m$, $20{\mu}m$ of lacquered layer removed without surface degradation when using 1064 nm wavelength with $1.0J/cm^2$ density. We could find out that Nd:YAG Laser is effective for removing remained lacquered layers when gilding an iron Buddha. In the future, when not only the metal has made various studies also wood lacquered furniture or the like, it seems to be utilized to remove the lacquer without surface damage.

• Journal of Conservation Science
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• v.33 no.6
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• pp.417-429
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• 2017

This study aimed at the identification of the black coating materials on the pottery surface and manufacturing technique of black burnished pottery excavated from the Pungnaptoseong, Seoul, which is estimated to be royal fortress of Beakje. According to observation of black coated surface and raw materials, potteries can be divided into two groups. The first group potteries have black inner and black surface with well-selected particles. Second group potteries are black in surface only with unevenly selected particles. Each group seems to represent different manufacturing technique in clay selection, color development timing and method. The black burnished pottery contains high values of CaO, $P_2O_5$, L.O.I. and lower content of $Fe_2O_3$ compared with gray pottery excavated from the same site, which indicates plant ashes were used for coloring the surface of pottery in black. According to the result of SEM-EDS mapping of black burnished pottery, carbon was concentrated on pottery surface, while iron was concentrated on the surface of the gray pottery. Based on XRD analysis, firing temperature of the black burnished potteries were fired low temperature range at 700 to $900^{\circ}C$, and that of the gray potteries ranged from $900^{\circ}C$ to $1000^{\circ}C$.

• Journal of the Korean Chemical Society
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• v.25 no.4
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• pp.275-282
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• 1981

A simple semiquantitative procedure was developed for the determination of sub-ppm level of chromium(VI) in aquatic samples by using an analytical micro-column packed with diphenylcarbazide(DPC) gel beads. DPC gel beads were prepared by swelling XAD-2 resin(115∼150 mesh in dry condition) in ethanol for 10min, packing into a glass column(1.5 mm bore, 65nm length) and adsorbing 1ml of ethanol solution of $2{\times}10^{-3}M$ DPC for 20min at room temperature. When 0.5ml of ethanol solution containing chromium(VI) was passed through the DPC gel column for 40min, the original white color of the reagent gel turned to red-violet from the up-stream of the column. As the length of colored band was proportional to the total amount of chromium(VI) in the sample solution passed through the column, the concentration of chromium(VI) could be determined from the calibration line which had been prepared by using the standard solution. Chromium(VI) ion as small as from 0.1 to 0.8 ppm could be determined with ${\pm}5{\sim}{\pm}15{\%}$ relative errors. Since other interfering cations were few, 100-fold excess of Fe(III), 50-fold excess of Cu(II) could be masked with EDTA. This method was successfully applied to the analysis of chromium(VI) in industrial effluents.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.8
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• pp.997-1006
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• 2010

For manufacturing modern cars, so-called multi-materials, such as aluminum alloy with high-strength steels, are used. For obtaining such materials, a new joining method is required to achieve the multi-material design. Mechanical clinching is one of joining methods used to join the dissimilar materials. The objective of this study is to investigate the characteristics of mechanical clinching of Al5052 alloy to high-strength steels (SPFC440, 590, 780). Using FE-analysis and clinching experiment, the joinability of Al5052 alloy to high-strength steel is evaluated by geometrical shape of mechanical clinched joint, such as neck-thickness and undercut. Further, the joint strength is evaluated by performing a single-lap shear test. The upper high-strength steel SPFC780 was not clinched because of the necking of the upper sheet. The joint strength increased with increasing strength of the upper sheet. For the lower high-strength steel sheet, the joinability and joint strength decreased with increasing strength of the lower sheet.

• The Korean Journal of Community Living Science
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• v.17 no.4
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• pp.81-95
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• 2006

This study was made to find out how stress affect on nutrition status of the college freshmen who were experiencing physical growth and development as well as drastic emotional change. 400 male and female freshmen in 4 year colleges were surveyed respectively through the health check-up procedure for college entrance in February, In order to find out the stress in each group frustration, deprivation, lack of self efficacy, type A behavior and anxiety response were surveyed through 10 questions with total 40 points by assigning 4 points for each question. Diet Status was expressed by DDS (Dietary Diversity Score by 5 food groups) and DVS(Dietary Variety Score). 24-hrs recall method was used to find out the quantity of daily nutrient of EAR(estimated adquacy ratio) by KDRIs(Korean Dietary Recommended Intakes). Nutrition level was analyzed by Can-Pro for professionals (Korea Nutrition Association). And for the quality intake, percentage was calculated and MAR(Mean Adequacy Ratio) were produced. Highest point was obtained in the stress of anxiety with the total 40 score of 30.20, and the scores were 29.79, 28.67, and 28.39 for deprivation, type A behavior and frustration respectively. There was no difference of blood components in accordance with stress type. Stress type was divided into less sensitive group and highly sensitive one and the relationship with the blood nutrient status was observed. The difference of blood component and blood pressure in sensitive and highly sensitive groups was observed in deprivation and anxiety. The index of blood pressure(p<0.05), hemoglobin(p<0.01), HDL-cholesterol(p<0.05), and Fe(p<0.05) was high in the deprivation of sensitive group. Blood pressure and hemoglobin was high in type A of sensitive group(p<0.05). And the contents of blood triglyceride was high in the anxiety of sensitive group(p<0.001) The result of nutrition intake analysis according to stress type showed that there was low intake for energy, riboflavin, and niacin. When the degree of deprivation was high there was a lack of riboflavin intake and there was no significant difference of nutrition intake in lack of self efficacy, type A behavior and anxiety response. Thus, it is necessary for colleges to educate the students to maintain mental stability through various programs and activities after catching a kind and extent of the stress college students we meeting with like the confusion of value system, open heterosexual relationship, and the employment difficulties linked with political uncertainty and economic recession.

• Journal of rehabilitation welfare engineering & assistive technology
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• v.6 no.1
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• pp.45-50
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• 2012

Thoracolumbar orthosis has been used for the rehabilitation of the patients with senile kyphosis. Recently, a number of different thoracolumbar orthosis designs have been introduced but its biomechanical effectiveness still remain unknown. In this study, we compared the pressure distribution on the surface of the trunk and stresses on the orthosis in relation to changes in connecting frame designs (Type 1, one-connecting frame type; Type 2, two-connecting frame type; Type 3, all-in-one type) using finite element (FE) models under different motions of the trunk. The results showed that Type 3 distributed the pressure on the trunk most evenly followed by Type 2 and Type 1 and the difference between Type 1 and Type 2 was negligible. ROM was limited most effectively by Type 3 ($8.5{\sim}9.4^{\circ}$), followed by Type 2 ($11.3{\sim}13.9^{\circ}$) and Type 1 ($12.1{\sim}15.4^{\circ}$). The ratio between the peak von Mises stress and yield strength of each material remained less than 20% regardless of orthosis type indicating low likelihood of component failure. In conclusion, our study found that all-in-one type of orthosis was the most effective design for the conservative treatment of spinal deformity in terms of function and comfort.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.3 no.2
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• pp.25-31
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• 1996

Various treaments such heating, acid tenting, acid healing, alkaline treating, acid+alkaline renting were attempted to investigate their effects on molar ratio, chemical composition, DTA and specific surface area(SSA) of natural zeolite poder. Molar ratio, Si to AI. of natural zeolite was 4.78, which represented high silica type. Composition of natural zeolite showed that $SiO_2$ was 66.34% $Al_2O_3$ was 13.89%, $Fe_2O_2$ was 1.55% X-ray diffraction showed that main component of natural zeolite was mordenite and clinoptliolite. Differential Thermal Analysis and Thermogravimetry curve of natural zeolite was showed to peak of endothermic peak at $80^{\circ}C$ and it means to the peak of dehydrate reaction, but recristalization was not formed below at $1,000^{\circ}C$. Weight loss during calcination was 16% at $1,000^{\circ}C$. Thermal treatments on SSA of natural zolite powder decreased from $75.2m^2/g\;to\;2.1m^2/g$. In contrast chemical treatments on SSA showed to increase to $300.2m^2/g$(1 N HCl treating), $54.9m^2/g$(1 N NaOH) and $90.9m^2/g$(HCl+NaOH)tudy, it could be proposed to employ acid tret method as packaging materisls for MA packaging.

• Korean Journal of Community Nutrition
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• v.17 no.6
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• pp.689-706
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• 2012

The purpose of this study was to evaluate effects of a nutrition education focused on Food Exchange System for the higher grades elementary children. Nutrition education lessons (40 min/lesson, 4 times), '5 major nutrients and functions', '6 food groups', 'daily needed energy and food exchange units', 'good choice of snacks and balanced exercise' were provided to elementary students (5th grade students). This research was based on the data from two groups of elementary school children in the 'education' group (n = 31) and 'non-education' group (n = 31). We assessed the changes in dietary attitude, food habit and nutrition knowledge using questionnaire and nutrient intake using 24hr recall method by nutrition education using the developed pamphlet. After education, there was a significant difference in the dietary attitude score only in attitude of 'balanced meal' (p < 0.001) in the education group compared to the non-education group. In food habit, there were significant positive changes in the type of breakfast and in the priority of choosing snack in the educated group. In nutrition knowledge, there were significant increases in scores of 'function of carbohydrate' (p < 0.05), 'function of fat' (p < 0.01), 'function of vitamin' (p < 0.01), 'foods of carbohydrate' (p < 0.01), and 'foods of vitamin' (p < 0.01) in the educated group. After education, carbohydrate: protein: fat (CPF) ratio was significantly different between the two groups (education group, 59 : 16 : 26 vs. non-education group, 63 : 15 : 23). In evaluation of nutrient intake by Dietary Reference Intakes for Koreans (KDRIs), there were significant positive effects in energy (p < 0.05), thiamin (p < 0.05), riboflavin (p < 0.05), vitamin C (p < 0.05), phosphorus (p < 0.01), Fe (p < 0.01) and zinc (p < 0.01) in the education group compared to the non-education group. In conclusion, the developed 4 times' nutritional education pamphlet focused on individual daily energy requirements and food exchange units using food exchange system for higher grades' elementary student may positively change nutrition knowledge and dietary intakes.