• Journal of the Korean Society of School Health
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• v.21 no.1
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• pp.33-41
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• 2008

Purpose : The purpose of this study was to provide the basic data for p lanning oral health education in elementary schol. Methods conducted using a postal, self-administered questionnaire. A questionnaire containing 19 questions about oral health education which was provided by health teachers in elementary schol was used for data colle ction. Total response rate was 64.3% (119 out of 185). Results : Oral health education except one through textbooks was conduc of which taught oral health themselves. The contents of oral he alth education through special clas was mainly focusing on the tothbrushing method, dental caries, and the use of fluo ride. Acording to the grades clasified by the level of education, the order was the 3rd, 1st, and 2nd grade, which mea ns that the lower grades got more training than the h was acquired through the internet (72.2%), health-related organizations or academies (51.5%). Also, materi als for oral health education were obtained from health-related organizations or academies (67%), self-productio n (49.5%). According to the data during the past 5 years it was found that 13.4% health teachers had oral health-related that more traing neded to be conducted from 89.7% health tea chers. The most dificult problem in oral health education were insufficient time (56.7%). Conclusion : For effective oral health education, there needs a developmen t of targeted goal to achieve a systemic oral health education for each grades as wel as a ned for as health teachers to eficiently acquire knowledge and materials for oral health education, it is necessary to hold regular workshops for health teachers, and develop and distribute appro priate educational materials.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.408-408
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• 2012

It is well known that magnetic random access memory (MRAM) is nonvolatile memory devices using ferromagnetic materials. MRAM has the merits such as fast access time, unlimited read/write endurance and nonvolatility. Although DRAM has many advantages containing high storage density, fast access time and low power consumption, it becomes volatile when the power is turned off. Owing to the attractive advantages of MRAM, MRAM is being spotlighted as an alternative device in the future. MRAM consists of magnetic tunnel junction (MTJ) stack and complementary metal- oxide semiconductor (CMOS). MTJ stacks are composed of various magnetic materials. FePt thin films are used as a pinned layer of MTJ stack. Up to date, an inductively coupled plasma reactive ion etching (ICPRIE) method of MTJ stacks showed better results in terms of etch rate and etch profile than any other methods such as ion milling, chemical assisted ion etching (CAIE), reactive ion etching (RIE). In order to improve etch profiles without redepositon, a better etching process of MTJ stack needs to be developed by using different etch gases and etch parameters. In this research, influences of $O_2$ gas on the etching characteristics of FePt thin films were investigated. FePt thin films were etched using ICPRIE in $CH_4/O_2/Ar$ gas mix. The etch rate and the etch selectivity were investigated in various $O_2$ concentrations. The etch profiles were studied in varying etch parameters such as coil rf power, dc-bias voltage, and gas pressure. TiN was employed as a hard mask. For observation etch profiles, field emission scanning electron microscopy (FESEM) was used.

• The Journal of Advanced Prosthodontics
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• v.8 no.6
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• pp.417-422
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• 2016

PURPOSE. The purposes of this study were to evaluate the staining resistance of CAD/CAM resin-ceramics polished with different techniques and to determine the effectiveness of the polishing techniques on resin-ceramics, comparing it with that of a glazed glass-ceramic. MATERIALS AND METHODS. Four different CAD/CAM ceramics (feldspathic ceramic: C-CEREC Blocs, (SIRONA) and three resin-ceramics: L-Lava Ultimate, (3M ESPE), E-Enamic, (VITA) and CS-CeraSmart, (GC)) and one light cure composite resin: ME-Clearfil Majesty Esthetic (Kuraray) were used. Only C samples were glazed (gl). Other restorations were divided into four groups according to the polishing technique: nonpolished control group (c), a group polished with light cure liquid polish (Biscover LV BISCO) (bb), a group polished with ceramic polishing kit (Diapol, EVE) (cd), and a group polished with composite polishing kit (Clearfil Twist Dia, Kuraray) (kc). Glazed C samples and the polished samples were further divided into four subgroups and immersed into different solutions: distilled water, tea, coffee, and fermented black carrot juice. Eight samples ($8{\times}8{\times}1mm$) were prepared for each subgroup. According to CIELab system, four color measurements were made: before immersion, immersion after 1 day, after 1 week, and after 1 month. Data were analyzed with repeated measures of ANOVA (${\alpha}=.05$). RESULTS. The highest staining resistance was found in gl samples. There was no difference among gl, kc and cd (P>.05). Staining resistance of gl was significantly higher than that of bb (P<.05). Staining resistances of E and CS were significantly higher than those of L and ME (P<.05). CONCLUSION. Ceramic and composite polishing kits can be used for resin ceramics as a counterpart of glazing procedure used for full ceramic materials. Liquid polish has limited indications for resin ceramics.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.431-433
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• 2009

We developed 4.8 inch WQVGA e-paper on plastic substrate using organic field effect transistors (OFETs). Polyethylene naphthalate (PEN) film was used as a flexible substrate and arrays of OFETs with bottom-gate, bottom-contact structure were fabricated on it. Lowtemperature curable organic gate insulating materials were employed and polymer semiconductor solutions were ink-jetted on arrays with high-resolution. At all steps, process temperature was limited below $130^{\circ}C$. Finally, we could drive flexible e-paper displays based on OFET arrays with the resolution of 100 dpi.

• Journal of the Korean Applied Science and Technology
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• v.38 no.1
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• pp.107-117
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• 2021

The purpose of this study is to provide basic data for the development of UV protection products using natural materials. The research method is investigation and analyzation of the current status of the domestic and foreign industries, natural material research trends, and patent status of skin care-related sunscreen. As the result of the study, the U.S. market for sunscreen is the largest one, accounting for about 21% of the world, and the Chinese market is rapidly growing. The top four major types of functional cosmetics in Korea are complex functional products, followed by wrinkle improvement, sunscreen and whitening, and both the global and domestic markets continue to grow continuously. Over the past decade, research trends in natural sunscreen materials have shown that Scutellaria baicalensis, Humulus lupulus L., licorice, Finger root, Green tea, lespedeza cuneata extracts are effective, and in addition, they are also effective in photo-aging, antioxidant, anti-inflammatory, antibacterial, whitening, and wrinkle improvement. The patent registration status is on the rise and the ingredients were secured from plants and seaweeds. As the conclusion of this research, It is expected that natural UV protection material will be able to be used as multi-functional cosmetics material by developing safe and proven natural materials in line with future global trends.

• Applied Chemistry for Engineering
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• v.31 no.5
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• pp.532-538
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• 2020

In this study, emulsification process were conducted to manufacture the natural sunscreen from raw materials such as shea butter, olive emulsifier wax, and green tea extract. The emulsification was optimized by using the central composite design model-response surface methodology (CCD-RSM) where the response values were established as the mean droplet size (MDS) and emulsion stability index (ESI) after 7 days in addition to UV absorbance at 300nm. The amount of emulsifier and additives and emulsification time were established as operating variables and the optimal conditions of sunscreen emulsification were accepted as 3.70, 2.47 wt.%, and 15.42 min, respectively according to the result of CCD-RSM. On the other hand, the response values were estimated as 1173.80 nm and 99.56% for MDS and ESI, respectively, after 7 days, in addition to UV absorbance at 300 nm (2.47). The average error from actual experiments was a low level as about 3.0 ± 1.5%, which is mainly due to the fact that the optimization using CCD-RSM applied in this study was in the relatively high significant level.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.4
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• pp.428-441
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• 2022

The purpose of this study is was to compare the color stability of alkasite and other restorative materials commonly used in the field of pediatric dentistry and to study a color change in response to various beverages. Test specimens of glass ionomer, resin modified glass ionomer, alkasite restorative material, and composite resin were prepared, and the color stability was measured after thermocycling. Each specimen was also subdivided into 5 groups and submerged in PBS, coffee, green tea, coke, and orange juice to analyze the color change from the original CIE L^*a^*b^* values after 7, 14, 21, and 28 days. Composite resin showed the best color stability after thermocycling, followed by alkasite restorative material, glass ionomer, and resin modified glass ionomer. Submerging in various beverages for 7 days resulted in color change in all test specimens, with alkasite restorative material showing less color change than glass ionomer but greater change than composite resin. Alkasite restorative material showed the greatest color change in coffee, followed by green tea and orange juice, but almost no change in coke and PBS even after 28 days of submersion.

• Journal of dental hygiene science
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• v.23 no.4
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• pp.351-360
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• 2023

Background: The purpose of this study is to investigate the tooth whitening effect of Listerine Healthy White and provide effective management of extrinsic discoloration by comparing the whitening effects of existing whitening products. Methods: The included study four groups: those using whitening gel, whitening toothpaste, and Listerine Healthy White and a control using artificial saliva. Each group received 40 bovine tooth specimens, which were stained with commonly consumed tooth-coloring-inducing foods; black tea, black coffee, and instant noodles for 72 hours. The specimens were treated with tooth whitening materials for 5 weeks, after which the lightness (L^*) was measured weekly using a spectrophotometer. Results: There was a significant difference in lightness among the groups between the 1st and 5th week of treatment for all tooth-coloring-inducing foods (p<0.05). When comparing the changes in lightness values from before whitening to the 5th week of whitening for all tooth-coloring-inducing foods, the order of change was as follows: whitening gel, whitening toothpaste, Listerine Healthy White, and artificial saliva. Listerine Healthy White showed a significant whitening effect for all tooth-coloring-inducing foods (p<0.05). Particularly, changes in lightness values for specimens stained by black tea after 5 weeks of whitening were in the following order: whitening gel (21.72), whitening toothpaste (14.89), Listerine Healthy White (12.91), and artificial saliva (3.85). For specimens stained by black coffee, the changes in lightness values were in the following order: whitening gel (12.99), whitening toothpaste (9.66), Listerine Healthy White (7.91), and artificial saliva (3.12). Lastly, changes in lightness values for specimens stained by instant noodles were as follows: whitening gel (10.84), whitening toothpaste (9.85), Listerine Healthy White (7.71), and artificial saliva (2.61). Conclusion: Listerine Healthy White exhibits continuous whitening effects over time, and for consumers seeking convenient ways to achieve tooth whitening effects at home, consistent use of Listerine Healthy White is recommended.

• Korean journal of food and cookery science
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• v.6 no.4 s.13
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• pp.69-83
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• 1990

Gynostemma pentaphyllum Makino is a kind of perennial liana plant belonging to the Cucurbitaceae family. Since it was first discovered and reported to the Japanese academy in 1977, it came to be widely known to China and Southeast Asia areas as well as Japan. In Korea its name began to appear in the first half of 1980's, and it is now being nationwidely cultivated and popularized as tea stuffs. Gynostemma pentaphyllum Makino has remarkably strong propagation power. In addition. since it contains a great quantity of beneficial components, especially saponin it is believed to have excellent medical effects, too. This study was undertaken to examine the value of Gynostemma pentaphyllum Makino as a health-promotint tea, by investigating the components creating the flaver of tea and the saponin ingredient making medical effects as well as by inspecting whether Gynostemma pentaphyllum Makino products show different component arrangements according to their growing districts. As raw materials of the experiment, three kinds of Gynostemma pentaphyllum Makino samples produced in Suwon, Geochang and Uleungdo were taken. To accomplish the formerly stated goals, the contained quantity of the proximate composition, free sugar, reducing sugar, free amino acid, minerals, tannin, caffeine and vitamin C were measured respectively and compared between the samples, while the saponin content was compared with heat extracted from panax ginseng. The results of the experiment are as follows: 1. In the case of the proximate composition, the crude fat content was the highest in the Gymostemma pentaphyllum Makino material from Geochang (1.62%), the second in that from Suwon (1.56%), and the lowest in that from Uleungdo (1.0%). In addition the Geochang: produced sample had the greatest quantity of the crude protein and ash contents: the order of the crude Protein content was the Geochang produced (17.83%), the Suwon-produced (15.87%), and the Uleungdo-produced(12.28%), while that of the ash content was the Geochang-produced (14.80%), the Uleungdo-produced(10.17%), and the Suwon-produced(9.34%). 2. As for the reducing sugar contents, the Suwon-produced scored the highest of the three (3.3%), while the Geochang-produced was 1.3% and the Uleungdo-produced 0.5%. The total content of free sugar was 1.07% (the Suwon-produced), and 0.49% (the Geochang-produced) respectively but the sample from Uleungdo showed almost no free sugar content. The contained quantity of fructose and glucose was the highest among the kinds of free sugar both in the Suwon-produced and in the Geochang-produced. 3. The content of amino acid was the highest in the Suwon-produced(1.41%), the second in the Geochang-produced(1.37%), and the lowest in the Uleungdo-produced(0.53%). In the experiment, sixteen kinds of amino acid were extracted-Asp. Thr. Ser. Glu. Gly. Ala. Val. Het. Ileu. Leu. Tyr. Phe. Lys. His. Arg. Try. All of them except glutamic acid and methionine showed the highest quantity score in the Suwon-produced, while the glutamic acid content was the higest in the Uleungdo-produced and the methionine content in the Geochang-produced. The sequential arrangement of the sixteen contents according to their magnitude ranged from glycine, aspartic acid, and glutamic acid (the highest) to tryptophan, serine and lysine (the lowest). 4. Ten kinds of mineral were detected-Ca, Mn, Cd, K, Na, Pb, Mg, Fe, Zn, Cu. Among them, the content of Cd, Na, Mg, Zn and Fe was the highest in the Geochang-produced and that of K in the Suwon-produced. 5. The Geochang-produced materials contained much a larger quantity of tannin (6.3%) than the Suwon-produced (2.6%). Neither caffeine nor vitamin C was detected in the three kinds of materials. 6. In the case of the saponin content the Geochang-produced showd 2.39%, the Uleungdo-produced 1.77% and the Suwon-produced 1.49% respectively. However, it was found also that the saponin content of Gymostemma pentaphyllum Makino was the same kind as that of panax ginseng.

• Journal of Physiology & Pathology in Korean Medicine
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• v.21 no.1
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• pp.219-225
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• 2007

This study was performed to provide basic ideas as understanding and application for oriental medicinal cuisine (Yak-Sun). To develop medicinal cuisine, it is necessary to grasp the theoretical system. And to develop medicinal cuisine for health enhancement, it is also required not only to consider constitutions but also to suggest the need of knowledge for moderation in terms of regimen along with the theory of oriental medicine. Also to develop medicinal cuisine according to the perspective of oriental medicinal theory, what should be taken into account is not only the understanding of the characteristics of food materials, but also the properties of them that the theory of oriental medicine. Lastly the scientific effect of the medicinal cuisine which is developed according to the oriental medicinal theory. And it is believed to De essential for the government to make effects to set a standard and laws to validate the medicinal effects and the process of assessment so that the systematic development can be encouraged, and to prepare guidance to food development for national health improvement. This research was planned and executed to evaluate how the composition of Yak-sun(oriental diet therapy) can effect health conditions of people who are suffering from diet-related diseases like cardiovascular related disease. by taking Yak-sun in a form of nutritional supplement with our daily meals. We produced Yak-sun tea with Mansam, Hwanggi, Tanggi and Paekchak and observed nutritional composition. We concluded that we could apply the components not only in a form of tea, but also in other forms of various food. The information we received from this conclusion will be a basic information on how we can apply oriental medicinal resources into other food and will also be a steppingstone for medicinal herbs to step foot in the field of functional food research, which already draws sizable attention world-wide.