• Fire Science and Engineering
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• v.31 no.5
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• pp.63-69
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• 2017

This study describes the development of a long-distance hose for ultra-high pressure operation, which can be used in conjunction with an ultra-high pressure pump and can be effectively applied to the fire suppression of high-rise buildings and a long, large tunnels. Also, it has phosphorescent properties, which can help to secure the withdrawal route of the fire-fighters when they are threatened by the fire. We developed an ultra-high pressure hose aiming at a pressure of 3 MPa and a flow rate of 2000 lpm and developed an ultra-high pressure fire hose that can withstand this very high pressure by using a double jacket, triple polyurethane coating and warf (Wp) of 52. In order to ensure the performance of the developed ultra-high pressure hose, its structure, appearance, leakage at high pressure, length and elongation were inspected by a certified certification agency, who also subjected it to a peeling test, friction test, breaking pressure test and free fall test. Also, it was studied in addition to the luminescent high-pressure hose for fire-fighting. In the phosphorescence test, the luminance measurement value was more than the reference value of the luminance test after 40 minutes, which confirmed that its performance was satisfactory for fire-fighting products. In the future, if such an ultra-high pressure fire hose were commercialized and applied in the field, it could contribute to securing improved fire suppression and safer exit from fires, as compared to the fire hoses currently used in the suppression of fires in skyscraper buildings and long tunnels.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.6
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• pp.1006-1012
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• 2004

We evaluated physicochemical and sensory characteristics of 25 commercial salt-fermented shrimps by kind (Oh Jeot, Yook Jeot and Chu Jeot) by manufacturer (traditional marketer (TS) ＆ company (CS)). Salinity and pH ranged 17.9∼28.7% and 7.82∼8.74, respectively, of which Chu Jeot was somewhat higher in salinity and pH, compared with those of the others. Amino nitrogen (AN), volatile basic nitrogen (VBN) and thiobarbituric acid reactive subjects (TBARS) showed great variation ranged with 21.41∼661.13 mg%, 263.2∼1180.2 mg% and 0.507∼1.322 $\mu\textrm{g}$/g, respectively. Hunter color of L value was 53.99∼67.45, a value, 4.98∼12.06 and b value, 4.45∼10.4. Physicochemical quality showed greater variations in Chu Jeot of TS than that of CS. Products of CS have higher salinity while lower VBN and AN than those of TS. Sensory results showed that mean scores of appearance, over-all taste, over-all flavor and over-all acceptability between TS and CS were not significantly different. The mean score of over-all acceptance was the highest in Yook Jeot. Physicochemical and sensory characteristics of salt-fermented shrimps in a PCA plot comprised of first principal component (68.36%) and second principal component (31.36%).

• Biomaterials Research
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• v.22 no.4
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• pp.328-336
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• 2018

Background: Biogenic fabrication of silver nanoparticles from naturally occurring biomaterials provides an alternative, eco-friendly and cost-effective means of obtaining nanoparticles. It is a favourite pursuit of all scientists and has gained popularity because it prevents the environment from pollution. Our main objective to take up this project is to fabricate silver nanoparticles from lichen, Usnea longissima and explore their properties. In the present study, we report a benign method of biosynthesis of silver nanoparticles from aqueous-ethanolic extract of Usnea longissima and their characterization by ultraviolet-visible (UV-vis), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses. Silver nanoparticles thus obtained were tested for antimicrobial activity against gram positive bacteria and gram negative bacteria. Results: Formation of silver nanoparticles was confirmed by the appearance of an absorption band at 400 nm in the UV-vis spectrum of the colloidal solution containing both the nanoparticles and U. longissima extract. Poly(ethylene glycol) coated silver nanoparticles showed additional absorption peaks at 424 and 450 nm. FTIR spectrum showed the involvement of amines, usnic acids, phenols, aldehydes and ketones in the reduction of silver ions to silver nanoparticles. Morphological studies showed three types of nanoparticles with an abundance of spherical shaped silver nanoparticles of 9.40-11.23 nm. Their average hydrodynamic diameter is 437.1 nm. Results of in vitro antibacterial activity of silver nanoparticles against Staphylococcus aureus, Streptococcus mutans, Streptococcus pyrogenes, Streptococcus viridans, Corynebacterium xerosis, Corynebacterium diphtheriae (gram positive bacteria) and Escherichia coli, Klebsiella pneuomoniae and Pseudomonas aeruginosa (gram negative bacteria) showed that it was effective against tested bacterial strains. However, S. mutans, C. diphtheriae and P. aeruginosa were resistant to silver nanoparticles. Conclusion: Lichens are rarely exploited for the fabrication of silver nanoparticles. In the present work the lichen acts as reducing as well as capping agent. They can therefore, be used to synthesize metal nanoparticles and their size may be controlled by monitoring the concentration of extract and metal ions. Since they are antibacterial they may be used for the treatment of bacterial infections in man and animal. They can also be used in purification of water, in soaps and medicine. Their sustained release may be achieved by coating them with a suitable polymer. Silver nanoparticles fabricated from edible U. longissima are free from toxic chemicals and therefore they can be safely used in medicine and medical devices. These silver nanoparticles were stable for weeks therefore they can be stored for longer duration of time without decomposition.

• Journal of the Korean Geophysical Society
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• v.4 no.1
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• pp.57-69
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• 2001

We have carried out a nondestructive close examination for the purpose of the structural safety diagnosis of the Three-Story Pagoda(Seokga Pagoda) in Bulkuk temple in the city of Kyungju, Kyungbuk, Korea. Ultrasonic wave velocities were measured at 456 points of the pagoda comprising 44 blocks to estimate the mechanical properties of rock blocks constituting the pagoda. The measured velocities have the range of 1217 to 4403 m/sec with the average of 3227 m/sec. The empirical relationship between the ultrasonic velocity and the uniaxial compressive strength yielded the estimation of strength of each block, ranging from 134 to 844 kg/cm^2 and averaging 463 kg/cm^2. With an assumption that the strength of each block is described as a random variables having a normal distribution, we calculated the probability of failure of rock blocks of the pagoda. Our investigation revealed that the probability of the structural failure due to the weight of higher blocks is very low. However, the probability of partial failure around contact area is substantial, which is consistent with the appearance that edges and the corners of some blocks were broken off. The platform under the body of the pagoda appeared to be structurally weak as the probability of tensile failure of the lower platform is up to 18%, and diagonal fractures are shown where the probability of failure is high.

• Journal of Sericultural and Entomological Science
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• v.50 no.2
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• pp.116-121
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• 2012

Cordyceps and its allies fungi has been described as a secret medicine that gives eternal youth and a long life. Some species of Cordyceps are sources of biochemicals, such ascordycepin, with interesting biological and pharmacological properties. Hence, it has been studied to uncover its pharmacological effect. We attempted to study the formation of fruiting bodies and to develop means of mass production Korean isolate of Paecilomyces tenuipes has been inoculated into silkworms, where it reproduced using culture container, mini-kit successfully. Culture container, mini-kit is composed of a cylinder-shaped body and lid. The container is made of translucent polyethylene terephthalate. The size of the container is $82{\times}75mm$, reduced by 10 times as compared with the conventional culture kit. The mini kit has many advantages - high culture amount, ability of maintaining optimal humidity, parasite-free cultivation and high-end appearance. With the kit, the optimal cultivation condition is under $22^{\circ}C$, culture period of 53 days. And synnemata of P. tenuipes could be kept fresh for 14 days at the temperature of under $10^{\circ}C$. Therefore, the Min-kit can be used in both ways as a culture container and a packing kit for end-user customers.

• Food Engineering Progress
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• v.14 no.4
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• pp.322-327
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• 2010

Wheat is widely used in food industry because of its low price, convenience, protein-rich resource, easy processibility, and so on. However, people who have wheat-gluten allergy need gluten-free products. Especially, gluten-free products are desirable to early childhood even though they may or may not be sensitive to wheat-gluten. As the alternative of wheat flour, recently, rice flour is gaining popularity. Hence, we developed the puffed rice snack for the baby. In order to prepare for rice extrudate, 1 kg rice flour, 450 g water, and 6 g salt were mixed together and then steamed for 1 hr. The rice extrudate was shredded into pieces (0.5 cm${\times}$0.5 cm) and dried up to 4.5% moisture content. The dried rice shreds were puffed at $257^{\circ}C$ in a puffing machine. The puffed rice snack was oval-shaped having thickness of 0.5 cm, white in color with brown flakes. Appearance and texture of the puffed rice snacks were evaluated by the measurement of the texture, isothermal water absorption, expansion, and the color. Puffed rice was more porous, because rice increased up to about two times larger than its original volume. Texture of the rice puffing snack was suitable for early childhood. Rice puffing snack showed potentials including soft, low-allergenic, and easily digestible properties. It is concluded that rice puffing snack has potential in the food markets for early childhood.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.133-138
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• 2019

This study evaluated the tensile properties of SAPH440, a hot-rolled steel for automotive structural applications, based on GMAW lap welding, the welding current, the welding voltage, and the feed rate. Tensile tests were performed according to the joint parameters of the GMAW process, for which specimens were fabricated according to KS B ISO 9018 by lap welding. The bead appearance was observed in each condition, and the weldability was evaluated by the tensile test. Higher the welding current resulted in a deeper weld, but the tensile strength was not significantly different from when the parameter was fixed due to the fracture of the base material. When the current was higher than the voltage, as in the case of a welding current of 200 A and welding voltage of 17 V, a large amount of spatter is generated, the welding is unstable, and the welded part breaks. Higher the voltage resulted in the bead not causing defects in general, and it also affected the weldability. If the current and voltage were too low, the welding was not performed normally, and the tensile strength could not be measured. However, as the current increased, the increase of the voltage and the feed rate did not affect the tensile strength.

• Journal of Life Science
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• v.29 no.9
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• pp.955-963
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• 2019

This study evaluated the characteristics and antioxidant properties of cookies prepared with different amounts (0%, 1%, 3%, 5%, and 7%) of Lentinus edodes water extract (LEWE). The baking loss rate of cookies increased as the amount of LEWE increased (p<0.05). The pH of cookies significantly decreased when amounts of LEWE increased (p<0.05), but spread factor, leavening rate, and moisture content showed no significant difference among the samples. L value and b value of cookies significantly decreased when amounts of LEWE increased (p<0.05), but a value of cookies significantly increased when amounts of LEWE increased (p<0.05). Hardness was higher in the 7% LEWE cookies. Chewiness and brittleness increased with increasing LEWE concentration, but cohesiveness and springiness showed no significant differences among the samples. Total polyphenol content and DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity significantly increased upon the addition of LEWE (p<0.05). In a sensory evaluation, the appearance, color, and taste of the cookies were rated higher in groups containing 0% LEWE, but the flavor, texture, and overall acceptability scores were highest for cookies with 1% LEWE added. These results suggest that cookies prepared by adding 1-3% LEWE achieve the best sensory evaluation and antioxidant activity.

• Korean Journal of Heritage: History & Science
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• v.49 no.1
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• pp.120-145
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• 2016

An understanding of 'original form' plays an important role as it is the starting point of heritage conservation. This paper delineated several types of understanding on 'original form' over times, and aims at analyzing the way how such concepts has provided a platform of repair works of timber buildings in Korea over times. Conservation in Korea was initiated by the attitude of the Japanese authority during the Colonial period and 'restoring into the earliest form', which had been set in the early stage of the Japanese conservation, has strongly influenced on Korean practice during the period. Such attitude has lasted even after the independence of Korea. In Japan, however, the attitude has shifted to taking a careful decision on the alteration of the existing form during the 1930s. In addition, examination and research in the repair work became essential steps to conduct along with the publication of the report of works. In Korea there has been lack of understanding on the importance of examination and research in repair works and the publication of report of the works has not been mandatory so that it has emphasized on the 'form' in conservation aiming at 'restoring the earliest form'. Such attitude has created the problem of replacing original material during the work which should aim at preserving and maintaining heritage in Korea. Because of these circumstances in preserving the architectural cultural properties in Korea, cultural buildings had succeeded in preserving the outer appearance but there are remaining questions on preserving the original states of them. This paper has pointed out that it is necessary to set out the principles of conserving 'original condition' through further study and discussion based on the careful consideration on both the international principles and Korean context.

• The Journal of the Convergence on Culture Technology
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• v.7 no.1
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• pp.58-65
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• 2021

Jewelry Object to adorn a body with has been a very important culture since the primitive age when history of human beings started. Ornaments for social status or wealth's symbolic icon otherwise for private embellishment have been developed with various properties such as decorative, monetary, scarce, historic ones. However, since the latter 20th century, when intellecture concept was more valuable than the tradition laying emphasis on preciousness, with counting of artistic activities and aesthetic values, they have had expressionistic tendency centered on artists. In this manner, modern ornaments have been developed as an artistic genre deviating from traditional way in which material or technology was emphasized. While this expressionistic tendency emphasized artistic value, galleries only for ornaments have been started since 1960s and especially from this period, a lot of experimental and revolutionary ornaments works deviating from traditional way have been exhibited. The appearance of galleries specialized in ornaments as described above had a great influence on the ornaments' development to an artistic genre. This study is the one in respect of two exhibition types through the combination of human body and clothes in displaying ornaments. The first one represents active displaying way for the communication with audience by introducing fashion show to galleries deviating from general exhibition way. The second one plans to run a project collaborating fashion brand for the communication between ornaments and clothes and represents displaying way in the shop of fashion brand for active exhibition publicity.