• The korean journal of orthodontics
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• v.19 no.2
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• pp.7-24
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• 1989

The physical properties of seven sizes of control groups and experimental group in stainless steel orthodontic wires were studied in tension, hardness, bending, torsion and observation of microstructure. The wires (0.40-0.90mm dia.) of round type were tested in the as-received condition. The wires of control groups were TRU-CHROME and REMANIUM, and experimental group was SK wire which was developed by ourselves and made in Korea. The results were as follows; 1. The chemical compositions of control groups and experimental group were austenite stainless steel wires of SOS 304. 2. Higher values of tensile and yield strength in tension were control group I, experimental group, control group II. Maximum tensile and yield strength of experimental group were $203.63{\pm}1.41kg/mm^2$ in 0.70mm diameter and $148.96{\pm}4.88kg/mm^2$ in 0.60mm diameter, and maximum elongation was $5.20{\pm}0.57%$ in 0.45mm diameter. 3. Hardness values of experimental group were similar to control groups. Maximum hardness values were $596.2{\pm}13.66Hv$ in 0.45mm diameter wire of control group I, $590.5{\pm}20.08Hv$ in 0.50mm diameter wire of control group II, and $563.6{\pm}5.35Hv$ in 0.70mm diameter wire of experimental group. 4. Torsion properties of experimental group were similar to control group I and more than control group II. Maximum torsion cycles were $31.8{\pm}2.48$ in 0.45mm diameter of control group I, $17.4{\pm}4.84$ in 0.60mm diameter of control group II, and $24.6{\pm}3.04$ in 0.45mm diameter of experimental group. 5. Maximum bending cycles of experimental group were smaller than control groups. Maximum bending cycles were $9.00{\pm}0.00$ in 0.50mm diameter wire of control group I, $10.0{\pm}0.82$ in 0.40mm diameter wire of control group II, and $8.0{\pm}1.26$ in 0.50mm diameter wire of experimental group. 6. Microstructures of experimental and control groups co-existed with martensited austenite structure and elongated austenite structure. 7. The direction of wire fracture was propagated parallel to torsion direction typically and there was no probability showing wire fracture at inclusions and surface scratches. 8. The type of wire fracture was brittle fracture at initiation site and ductile fracture at core.

• Journal of Navigation and Port Research
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• v.31 no.5 s.121
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• pp.435-445
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• 2007

Ship structures are thin-walled structures and lots of cutouts, for example, of inner bottom structure, girder, upper deck hatch, floor and dia-frame etc. In the case where a plate has cutout it experiences reduced buckling and ultimate strength and at the same time the in-plane stress under compressive load produced by hull girder bending will be redistributed. In the present paper, we investigated several kinds of perforated stiffened model from actual ship structure and series of elasto-plastic large deflection analyses were performed to investigate into the influence of perforation on the buckling and ultimate strength of the perforated stiffened plate varying the cutout ratio, web height, thickness and type of cross-section by commercial FEA program(ANSYS). Closed-form formulas for predicting the ultimate strength of the perforated stiffened plate are empirically derived by curve fitting based on the Finite Element Analysis results. These formulas are used to evaluate the ultimate strength, which showed good correlation with FEM results. These results will be useful for evaluating the ultimate strength of the perforated stiffened plate in the preliminary design.

• Restorative Dentistry and Endodontics
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• v.35 no.3
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• pp.222-228
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• 2010

The purpose of this study was to compare mineral trioxide aggregate (MTA; Dentsply, Tulsa Dental, Tulsa, OK, USA), which is widely used as root-end filling material, with DiaRoot BioAggregate (DB; Innovative BioCaramix Inc, Vancouver, BC, Canada), newly developed product, by using MG63 osteoblast-like cells. MTA, DB, and Intermediate Restorative Material (IRM; Dentsply Caulk, Milford, DE, USA) were used for root-end filling material while tissue culture plastic was used for control group. Each material was mixed and, the mixtures were left to set for 24 hours. MG63 cells were seeded to each group and then they were cultured for attachment for 4 hours. Following the attachment of cells to the root-end filling material, early cellular response was observed. After another 12 hours'culture, the level of attachment between cells and material was observed and in order to identify the effect of each material to bone formation, transforming growth factor beta1 ($TGF{\beta}1$) and osteocalin (OC) were estimated by using enzyme-linked immunosorbent assay (ELISA), and the amount of alkaline phosphatase (ALP) was also measured. The data were analyzed using one-way ANOVA. As a result, only at OC and the number of cells which were attached to materials, there was no statistical difference between MTA and DB. At other items, there was statistically significant difference in all groups. Although DB has not shown exactly the same cellular response like that of MTA, the number of attached cells shows that biocompatibility of the material and OC indicates bone formation rate. Therefore, if DB is used for root end filling material, it is expected to lead to similar results to MTA.

• Explosives and Blasting
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• v.22 no.3
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• pp.57-64
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• 2004

There are two major types of underwater blasting at Korea, bridges and harbor construction work. Pier blasting for lay the foundation bridges construction is used dry excavation working (drilling and charging) after pump out water and then fire pump in water that is same as bench blasting. In contrast, underwater blasting for harbor construction and increase of harbor load depth is used to barge with digging equipment that is in oder to drilling on the surface and blasting work(charge, hook-up) under water. Thus, there are need to special concern such as charge method and hook-up method different from tunnel blasting work and bench blasting work. If do not use special concern breaks out dead pressure and mis fire because of there are so many difficult condition such as water pressure, obstruct field of vision. In this study underwater blasting at Busan Harbor Construction have consider with special concern that is plastic pipe charge method used to MegaMITE I and specialized buoy hook- up method make far initial system detonate on the surface used to TLD. The results is designed blast pattern charge per delay effect an inspection of verify between predict velocity and measure velocity. minimized break out mis fire consideration charge method, hook up method. According to result best underwater blasting design is 105mm drilling dia, MeGAMITE II, HiNLL Plus(non electric detonator).

• Culinary science and hospitality research
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• v.14 no.1
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• pp.144-151
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• 2008

This study investigated the changes in the contents of allicin and diallyl disulfide and in the alliinase activity during the vacuum freeze drying of onion samples treated as the whole, sliced and crushed forms. The contents of allicin and diallyl disulfide in raw onions were 26.40ppm and 2.78ppm respectively. The contents of allicin and diallyl disulfide of onion samples treated as the whole, sliced and crushed forms increased with the progress of vacuum freeze drying. The degree of increase was different in each onion sample form prepared by vacuum freeze drying(p<0.05). The specific activity of alliinase in raw onions was 7.536 units/mg protein. The activity in onion samples treated as the whole, sliced and crushed forms decreased with the progress of vacuum freeze drying. The activity in the whole onion prepared by the vacuum freeze drying for 8 hrs reduced to 5.516 units/mg protein with 73.2% remaining and to 3.304 units/mg protein with 43.8% remaining for 36 hrs. The activity in the sliced onion prepared by the vacuum freeze drying for 36 hrs reduced to 2.366 units/mg protein with 31.4% remaining and the activity in the crushed onion prepared by the vacuum freeze drying for 36 hrs reduced to 2.232 units/mg protein with 29.6% remaining. The alliinase in onion sample treated as the whole form showed the highest remaining activity during the vacuum freeze drying.

• Korean Journal of Food Science and Technology
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• v.18 no.3
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• pp.187-191
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• 1986

Vitamin retention in rice bran during the extrusion cooking adapted for the rice bran stabilization was studied. The rice bran of different moisture content (9.5% and 15.6%) were extruded with cooking extruder (screw dia: 100mm. strew rpm:900. L/D ratio: 10.0) under the given conditions of specific power consumption(42.1 67.9 W/Kg) and extrusion temperatures $(99-135^{\circ}C)$. The affected retention rates of thiamine, riboflavin and niacin in extruded rice bran were determined. The extruded rice bran with higher moisture level had a lower or similar vitamin retention rate at lower specific power consumption and extrusion temperatures, relatively. The vitamin retention in extruded rice brail with the same moisture level were gradually decreased by the increased specific politer consumption and extrusion temperatures. The vitamin retention of rice bran during the extrusion cooking for the rice bran stabilization were observed as 89.9-97.0% for thiamin, 83.4- 97.3% for riboflavin and 94.0 - 97.7% for niacin, respectively.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.4
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• pp.260-266
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• 2008

Small lysimeter experiment under rain shelter plastic film house was conducted to investigate the effect of soil characteristics on the leaching and soil solution concentration of nitrate and phosphate. Three soils were obtained from different agricultural sites of Korea: Soil A (mesic family of Typic Dystrudepts), Soil B (mixed, mesic family of Typic Udifluvents), and Soil C (artificially disturbed soils under greenhouse). Organic-C contents were in the order of Soil C ($32.4g\;kg^{-1}$) > Soil B ($15.0g\;kg^{-1}$) > Soil A ($8.1g\;kg^{-1}$). Inorganic-N concentration also differed significantly among soils, decreasing in the order of Soil B > Soil C > Soil A. Degree of P saturation (DPS) of Soil C was 178%, about three and fifteen times of Soil B (38%) and Soil A (6%). Prior to treatment, soils in lysimeters (dia. 300 mm, soil length 450 mm) were tabilized by repeated drying and wetting procedures for two weeks. After urea at $150kg\;N\;ha^{-1}$ and $KH_2PO_4$ at $100kg\;P_2O_5\;ha^{-1}$ were applied on the surface of each soil, total volume of irrigation was 213 mm at seven occasions for 65 days. At 13, 25, 35, 37, and 65 days after treatment, soil solution was sampled using rhizosampler at 10, 20, and 30 cm depth and leachate was sampled by free drain out of lysimeter. The volume of leachate was the highest in Soil C, and followed by the order of Soils A and B, whereas the amount of leached nitrate had a reverse trend, i.e. Soil B > Soil A > Soil C. Soil A and B had a significant increase of the nitrate concentration of soil solution at depth of 10 cm after urea-N treatment, but Soil C did not. High nitrate mobility of Soil B, compared to other soils, is presumably due to relatively high clay content, which could induce high extraction of nitrate of soil matrix by anion exclusion effect and slow rate of water flow. Contrary to Soil B, high organic matter content of Soil C could be responsible for its low mobility of nitrate, inducing preferential flow by water-repellency and rapid immobilization of nitrate by a microbial community. Leached phosphate was detected in Soil C only, and continuously increased with increasing amount of leachate. The phosphate concentration of soil solution in Soil B was much lower than in Soil C, and Soil A was below detection limit ($0.01mg\;L^{-1}$), overall similar to the order of degree of P saturation of soils. Phosphate mobility, therefore, could be largely influenced by degree of P saturation of soils but connect with apparent leaching loss only more than any threshold of P accumulation.

• Journal of the Korean Chemical Society
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• v.44 no.2
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• pp.95-101
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• 2000

Macroacyclic transition metal complexes such as $Cu(H_2L[A]).H_2O$, $Cu(H_2L[B]).H_2O$, CuFe(L[A]($NO_3$).$4H_2O$, CuFe(L[B])($NO_3$).$4H_2O$, [$CuGd(H_2L[A])(NO_3)_2](NO_3).2CH_3OH$, [CuGd($H_2L$[B])($NO_3)_2$]($NO_3).2CH_3OH were prepared from the corresponding hexadentate compartmental ligands, $H_4L[A]$ and $H_4L[B]$, which were obtained by the condensation of 2-hydroxy-3-hydroxymethy1-5-methyIbenzaldehyde(HHNNB) and ethylenediamine or l,3-diaminopropane. Ln-macrocyclic([20]DOTA) complexes,[Ln([20]DOTA)($NO_3)(H_2O)$]($NO_3$)2.$xH_2O${Ln(III)=Pr, Sm, Gd, Dy, which had been synthesized from 2,6-diformyl-p-cresol(DFPC), was placed in methanol for 2 days, and [Ln([20] DOTA)($NO_3)(CH_3OH)]^{2+}$ was formed The equilibrium constants (k) for the substitution of coordinated $CH_3OH$ in the Ln-[20]DOTA complexes by various bidentate auxiliary ligands, $L_a$(=o-phenylenediamine,1,10-phenanthroline, ethylenediamine,oxalicacid, malonic acid, acethylacetone) were determined by spectroscopic method at $25^{\circ}C$ and 0.1M $NaClO_4$.The pKa of auxiliary ligands is in the order of o-phenylenediamine < 1,10-phenanthroline < ethylene-diamine, oxalic acid < malonic acid < acethylacetone. However, the equilibrium constant(K) has shown thetrend of ethyleneiamine < 1,10-phenanthroline < o-phenylenediamine, acethylacetone < malonic acid < oxalic acid.

• Cross-Cultural Studies
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• v.37
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• pp.211-231
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• 2014

Comment faciliter l'apprentissage du français pour rendre notre enseignement plus efficace? Beaucoup de recherches ont ${\acute{e}}t{\acute{e}}$ $men{\acute{e}}es$ sur cette question; en $r{\grave{e}}gle$ $g{\acute{e}}n{\acute{e}}rale$ l'enseignement de la langue d'une part et l'expression ${\acute{e}}crite$ et la $r{\acute{e}}flexion$ d'autre part ${\acute{e}}taient$ $men{\acute{e}}es$ $ind{\acute{e}}pendamment$. Notre intention dans ce $pr{\acute{e}}sent$ travail a ${\acute{e}}t{\acute{e}}$ d'introduire et $d^{\prime}e xp{\acute{e}}rimenter$ pendant $l^{\prime}ann{\acute{e}}e$ scolaire des cours associant le $d{\acute{e}}bat$ $d^{\prime}id{\acute{e}}e$ et la $r{\acute{e}}flexion$ $th{\acute{e}}matique$ avec l'apprentissage linguistique(grammaire, vocabulaire${\dots}$), afin de susciter $l^{\prime}i nt{\acute{e}}r{\hat{e}}t$ des apprenants, leur $curiosit{\acute{e}}$ et leur $vivacit{\acute{e}}$, au $del{\grave{a}}$ des $d{\acute{e}}fis$ $pos{\acute{e}}s$ par la langue française. Nous avons en particulier $utilis{\acute{e}}$ une $publicit{\acute{e}}$ comme support d'apprentissage des bases linguistiques et comme moteur $d^{\prime}{\acute{e}}veil$ ${\grave{a}}$ la civilisation française pour mobiliser leur attention et stimuler leur $activit{\acute{e}}$ cognitive par $l^{\prime}interdisciplinarit{\acute{e}}$. Nous avons donc $expos{\acute{e}}$ ici les exemples d'argumentation autour les deux $s{\acute{e}}quences$ publicitaires conduites avec les ${\acute{e}}tudiants$ et les arborescences $d{\acute{e}}gag{\acute{e}}es$ de ces analyses. Presque concomittamment ${\grave{a}}$ "voir" et "${\acute{e}}couter$", l'information est $trait{\acute{e}}e$ par $l^{\prime}activit{\acute{e}}$ "$d{\acute{e}}coder$". Nous approfondissons ensemble cette $interpr{\acute{e}}tation$ $s{\acute{e}}miotique$, et l'analyse de la façon dont la $publicit{\acute{e}}$ capte l'attention du spectateur nous $am{\grave{e}}ne$ ${\grave{a}}$ $d{\acute{e}}gager$ des faits de $soci{\acute{e}}t{\acute{e}}$ et ${\grave{a}}$ y $r{\acute{e}}fl{\acute{e}}chir$; comment, avec l'exemple de la $publicit{\acute{e}}$ jouant la musique $d{\acute{e}}licieuse$ de la gourmandise, nous entrevoyons la $r{\acute{e}}alit{\acute{e}}$ obscure de $l^{\prime}ob{\acute{e}}sit{\acute{e}}$ infantile. Ces approches interdisciplinaires ${\grave{a}}$ partir du multi-$m{\acute{e}}dia$ $r{\acute{e}}pondent$ ${\grave{a}}$ la $n{\acute{e}}cessit{\acute{e}}$ de distance critique que requiert la $soci{\acute{e}}t{\acute{e}}$ contemporaine. $L^{\prime}{\acute{e}}tude$ d'une $s{\acute{e}}quence$ publicitaire ne permet certes pas $d^{\prime}appr{\acute{e}}hender$ la $soci{\acute{e}}t{\acute{e}}$ française dans sa $globalit{\acute{e}}$, mais en $consid{\acute{e}}rant$ que notre travail consiste tout autant ${\grave{a}}$ stimuler la $facult{\acute{e}}$ critique $qu^{\prime}{\grave{a}}$ favoriser l'apprentissage linguistitique, notre $strat{\acute{e}}gie$ nous permet de $r{\acute{e}}aliser$ plusieurs objectifs autour d'un $m{\hat{e}}me$ axe d'enseignement.

• Journal of Nutrition and Health
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• v.6 no.3
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• pp.47-63
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• 1973

This study concerns the nutritional status of food in a lunch-box and the school lunch program provided for Dong Duck Elementary School Pupils in Daegu. Two hundred andsix pupils were randomly selected as a sample. The nutrients contained in a lunch-box and school lunch menu were analyzed according to the Food Composition Table. Nutrients and cost of the Dong Duck Elementary School Lunch were compared to the average nutrient contents of food in a lunch-box of o pupil. In addition, comparisons between the Recommended Daily Allowances of nutrients for Korean children aged from 9 to 11 (4th, 5th, and 6th grade) and that of the contained nutrients in the average lunch-box were conducted. The average nutrients contained in the lunch-box compared with the Recommended Daily Allowances are: Calorie 77.41% (542.60ca1), Protein 73.60% (16.93gr), Fat 33.95% (3.95gr), Calcium 27.85% (111.39mg), Ferret 80.30% (2.65mg), Vitamin A 10.09% (100.93 I.U.), Vitamin Bl 70.27% (0.27mg), Vitamin B2 88.37% (0.38mg), Vitamin C 15.40% (3.45mg). All of the nutrients in the lunch-box fall far below the Recommended Daily Allowances for the 9-11 age group. The average nutrients of staple food in the lunch-box compared with the side-dishes were found to contain Calorie 90.80%, Protein 50.32%, Fat 58.27%, Calcium 37.07 %, Ferret 53.96%, Vitamin A 0.0028%, Vitamin B1 78.11%, Vitamin B2 21.09%. The nutrients of food contained in the Dong Duck Elementary School Lunch Program compared with the Recommended Daily Allowances were: 1. The Protein, Fat, Ferret, Vitamin B1 and Vitamin B2 content was generally satisfactory. 2. Calcuim, Vitamin A and Vitamin C were lower than the Recommended Daily Allowances. 3. The Calorie content was generally lower for the 9-11 age group. The per pupil cost of the lunch-box was 41.87 won which includes the cost of staple food 16.92 won and side-dishes 24.95 won, whereas the school lune Provided by Dong Duck Elementary School Costs 35 won per pupil. Questionnaires were sent to four hundred parents (through their children) to find out their attitude toward the school lunch program. 390(97.50%) of them were returned and 7 of them dia not answer at all. Therefore, these were eliminated from the samlpe. Among 185 parents whose children were eating the school lunch; 172 parents (92.97% ) would pay 40 won for the proposed new school lunch program whereas only 13 parents (7.03%) did not want it. Among 198 parents whose children were not having the school lunch, 58 parents (29.29%) would agree to have the lunch for their children at the cost of 35 won with the proposed new school lunch program equivalent to 40 won. 126 parents (63.63%) could not agree to have their children being the school lunch because of their financial difficulty (74 parents 58.72%). The rest of parents (52 parents 41.28%) raised other reasons which were minor problems. Among the tatal of 383 parents, 309 parents (80.68%) would agree to gave school lunch for their children if the cost of the proposed new school lunch program would be 35 won to 40 won and if minor problems concerning the school lunch program are solved. Sixty parents (15.66% ) raised questions about the school lunch program concerning sanitary problems, taste of bread, and the quantity of lunch. Among 383 parents, 358 parents answered and 25 parents did not. When school officer asked if the parents would help during the school lunch hour, 101 parents indicated they could not help at all, but 177 parents, replied they could help. Among 177 parents, 40 parents of them could share their time from one or two hours everyday except Saturday and 107 parents could serve 1 to 3 days per week. Through this study, it is evident that further investigation should be done of the school lunch program which can be provided 35 won with the proposed new school lunch program. The parents participation in the school lunch program would be improved the understanding between school and parents as well as insure better nutrition and sanitation for the children.