• Journal of the Optical Society of Korea
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• v.17 no.6
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• pp.548-558
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• 2013

In this work, laser induced breakdown spectroscopy (LIBS) is used to investigate soil samples collected from different desert areas of Riyadh city in Saudi Arabia. Both qualitative analysis and plasma parameters are studied via the observed LIBS spectra. These experiments have been done using a Spectrolaser-7000 system with 50 mJ fundamental wavelength of Nd:YAG laser and detection delay time of 1 microsecond. Many spectral lines are highly resolved for many elements like Al, Fe, Mg, Si, Mn, Na, Ca and K. The electron temperatures Te and electron densities Ne, for the constituent of generated LIBS plasma, are determined for all the collected samples. It is found that both Te and Ne vary from one desert area to other. This variation is due to the change of the elemental concentration in different desert areas that affects the sample's matrices. Time dependent measurements have also been performed on the soil samples. While the signal-to-base ratio (SBR) reached its optimal value at 1 microsecond, the plasma parameters Ne and Te reach values of $4{\times}10^{17}cm^{-3}$ and 9235 K, respectively, at 2.5 microsecond. The later indicate that the plasma cooling processes are slow in comparison to the previously observed results for metallic samples. The observed results show also that in the future it is possible to enhance the exploitation of LIBS in the remote on-line environmental monitoring application, by following up only the values of Ne and Te for one element of the soil desert sample using an optical fiber probe.

• Composites Research
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• v.35 no.3
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• pp.161-174
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• 2022

SiC fiber-reinforced SiC matrix composite is a promising accident-tolerant fuel cladding material to improve the safety of light water nuclear reactors. Compared to the current zirconium alloy fuel cladding as well as metallic accident-tolerant fuel cladding, SiC composite fuel cladding has exceptional accident-tolerance such as excellent structural integrity and extremely low corrosion rate during severe accident of light water nuclear reactors, which reduces reactor core temperature and delays core degradation processes. In this paper, we introduce the concept, technical issues, and properties of SiC composite accident-tolerant fuel cladding during operation and accident scenarios of light water nuclear reactors.

• Journal of Periodontal and Implant Science
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• v.32 no.1
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• pp.89-112
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• 2002

The earliest reports of the use of electrical energy to directly stimulate bone healing seem to be in 1853 from England, the techniques involved the introduction of direct current into the non-united fracture site percutaneously via metallic needles, with subsequent healing of the defect. One endpoint of the periodontal therapy is to generate structure lost by periodontal diseases. Several procedural advances may support regeneration of attachment, however, regeneration of alveolar bone does not occur consistently. Therefore, factors which stimulate bone repair are areas for research in periodontal reconstructive therapy. Effects of cytokines or growth factors on bone repair are examples of such areas. Another one is electrical current which occurs in bone naturally, so that such bone may be particularly susceptible to electrical therapy. The purposes of this study were to observe the effects of electrical stimulation on the normal periodontium, to determine whether the electricity is the useful means for periodontal regeneration or not. Forty rats weighted about 100 gram were used and divided into 4 groups, the first group, there was no electrical stimulation with the connection of electrodes only. In the second group, there was stimulated by the 10 mA during 10 minutes per a day, in the third group was stimulated by the 25 mA , and the fourth by the 50 mA. At 3, 5, 10 and 15 days post-appliance , two rats in each group were serially sacrificed. and the maxillae and the mandible processed to paraffin, and the specimens were prepared with Hematoxylin-Eosin stain for the light microscopic evaluation. The results of this study were as follows : 1. There was the distinct reversal line on the lingual alveolar crest, whereas a little changes in the labial alveolarcrest to the duration and amount of currents. 2. In 50 mA group, the cells were highly concentrated at the apex of anterior teeth, and was observed the necrotic tissue. In posterior root apex, the hypercementosis was appeared, and newly formed cementum layer has been increased continuously with the time. 3. The periodontal ligament fiber and Sharpey's fiber were arranged in order, and the bone trabeculae were increased as the experiment proceeded by, relatively the bone marrows were decreased. 4. In the pulp tissue, the blood vessels were increased with blood congestion in the experimetal specimens remarkably, and the dentinal tubules were obstructed . 5. The osteoblasts in alveolar bone proper had been showed highly activity, and also observed the formation of bone trabeculea. In the conclusion, it was suggested that the electrical stimulation has influence on the periodontium and the pulp tissue. However, there might be the injurious effects.

• Animal Bioscience
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• v.37 no.2
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• pp.228-239
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• 2024

Objective: The objective of the experiment was to study yeast supplementation (yeast, Y) and dried kratom leaves (DKTL) on the digestibility, ruminal fermentation, blood metabolites and nitrogen balance in goats. Methods: Four of 7 to 8 months old male crossbred (50% Thai Native-Anglo Nubian) goats with average liveweight 20±0.13 kg were randomly assigned according to a 2×2 factorial arrangement in a 4×4 Latin square design to receive four diets ad libitum basis. The study investigated the effects of two levels of yeast (Y) supplementation (Y, 0 and 0.5g/kg dry matter [DM]) along with two levels of DKTL supplementation (DKTL, 0 and 4.44g/kg DM). The experimental groups were as follows: T1 = control group with 0Y+0DKTL, T2 = 0Y+4.44 DKTL, T3 = 0.5Y+0DKTL, and T4 = 0.5Y+4.44 DKTL. Results: The results showed that there were no interactions between Y levels and DKTL levels with respect to total DM intake, but there were significant effects (p<0.05) by levels of Y; goats receiving 0.05 g/kg DM Y had higher than goats fed 0.0 g/kg DM on average (kg/d). A percentage of body weight (% BW) and grams per kilogram of metallic weight (g/kg w^0.75) had no influence on yeast levels and DKTL, but there was a difference (p<0.05) by yeast level Y at 0.5 g/kg DM, being higher compared to the non-supplemented group. Apparent digestibility coefficient of nutrition in the form of (DM, organic matter, crude protein, neutral detergent fiber, and acid detergent fiber) was an increased trend in the Y-level complementary group at 0.5 g/kg DM and DKTL at 4.44 g/kg DM, respectively. Protozoa populations decreased in the group receiving Y levels at 0.5 g/kg DM and DKTL levels at 4.44 g/kg DM when compared to group T1. The acetic acid concentration and methane gas generation decreased (p<0.05) in the group receiving Y levels of 0.5 g/kg DM and DKTL levels of 4.44 g/kg DM, while the amount of propionic acid increased (p<0.05). Conclusion: Effects of feeding combinations of Y and DKTL supplementation on feed showed no interaction effect (Y×DKTL) on feed intake, rumen fermentation, bacterial and fungi population. The effect on protozoal populations was lower in the group that was supplemented with DKTL at 4.44 g/kg DM related to synthetic CH₄ was reduced.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2344-2349
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• 2015

In Korea, summer is hot and humid, and air-conditioners consume too much electricity due to large amount of latent heat. Simultaneous usage of dehumidifier may reduce the latent heat and save the electricity. In this study, dehumidification performance was measured in a constant temperature and humidity chamber for a small-sized dehumdification rotor made of inorganic fiber impregnated with metallic silicate. Variables were rotor speed, room temperature, regeneration temperature, room relative humidity and frontal velocity to the rotor. Results showed that there existed optimum rotor speed (1.0 rpm), and optimum regeneration temperature ($100^{\circ}C$). Above the optimum rotor speed, incomplete regeneration is responsible for reduced dehumidification. Above the optimum regeneration temperature, increased temperature difference between regeneration and dehumidification process is responsible for reduced dehumidification. The amount of dehumidification also increases with the increase of relative humidity, dehumidification temperature and flow velocity into the rotor.

• Korean Journal of Heritage: History & Science
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• v.46 no.2
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• pp.4-25
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• 2013

Goli-su is the innovative special kind of the embroidery technique, which combines twining and interlacing skill with metal technology and makes the loops woven to each other with a strand. The loops floating on the space of the ground look like floating veins of sculpture and give people the feeling of the openwork. This kind of characteristic has some similarities with the lacework craft of Western Europe in texture and technique style, but it has its own features different from that of Western Europe. It mainly represents the splendid gloss with metallic materials in the Embroidered cloth, such as gold foil or wire. In the 10th century, early days of Goryo, we can see the basic Goli-su structure form of its initial period in the boy motif embroidery purse unearthed from the first level of Octagonal Nine-storied Pagoda of Woljeong-sa. In the Middle period of Joseon, there are several pieces of Goli-su embroidered relic called "Battle Flag of Goryo", which was taken by the Japanese in 1592 and is now in the Japanese temple. This piece is now converted into altar-table covers. In 18~19th century, two pairs of embroidered pillows in Joseon palace were kept intact, whose time and source are very accurate. The frame of the pillows was embroidered with Goli-su veins, and some gold foil papers were inserted into the inside. The triangle motif with silk was embroidered on the pillow. The stitch in the Needle-Looped embroidery is divided into three kinds according to comprehensive classification: 1. Goli-su ; 2. Goli-Kamgi-su ; 3. Goli-Saegim-su. From the 10th century newly establishing stage to the 13th century, Goli-su has appeared variational stitches and employed 2~3 dimensional color schemes gradually. According to the research of this thesis, we can still see this stitch in the embroidery pillow, which proves that Goli-suwas still kept in Korea in the 19th century. And in terms of the research achievement of this thesis, Archetype technology of Goli-su was restored. Han Sang-soo, Important Intangible Cultural Heritage No. 80 and Master of Embroidery already recreated the Korean relics of Goli-su in Joseon Dynasty. The Needle-Looped embriodery is the overall technological result of ancestral outstanding Metal craft, Twining and Interlacing craft, and Embroidery art. We should inherit, create, and seek the new direction in modern multi-dimensional and international industry societyon the basis of these research results. We can inherit the long history of embroidering, weaving, fiber processing, and expand the applications of other craft industries, and develop new advanced additional values of new dress material, fashion technology, ornament craft and artistic design. Thus, other crafts assist each other and broaden the expressive field to pursue more diversified formative beauty and beautify our life abundantly together.