• Korean Journal of Food Science and Technology
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• v.47 no.3
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• pp.273-280
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• 2015

Lentils (Lens culinaris) are a nutritious and popular food throughout the world. This review provides an overview of the nutritional and functional properties of lentils. Lentils have high nutritional value: high protein, high fiber, low fat, and a variety of minerals. The addition of lentils to other foods could enhance their health benefits. Additionally, there is no decrease in the amino acid content in lentils when cooked; rather, the amino acids increased and the phytic acids decreased. Lentils are generally known to have biomedical functions including antioxidative, anti-cancer, anti-inflammatory, antihypertensive, and thrombolytic properties. The data presented here show that fermentation would increase the amount of bioactive substances in the beans. Therefore, fermentation techniques could be a new approach to produce lentil-based foods. They are also eco-friendly, cost-effective, and feasible processes. This review has suggested a future development of new lentil-related foods using traditional fermentation technology.

• Journal of Life Science
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• v.23 no.10
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• pp.1209-1215
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• 2013

Graphene is an allotrope of carbon that is composed of one-atom-thick planar sheets. It is known to have a preventive effect on cancer in photothermal therapy and a protective effect in DNA oxidation. The effect of graphene on oxidative stress and matrix metalloproteinases (MMPs) was investigated in human fibrosarcoma HT1080 cells. The results showed that graphene specifically exerted an inhibitory effect on DNA oxidation, but it did not inhibit other oxidative stress. In addition, graphene decreased the expression and the activation of MMP-2 and MMP-9 stimulated by phenazine methosulfate-m, which induces the production of intracellular hydrogen peroxide. In particular, the expression of antioxidant enzymes, such as superoxide dismutase (SOD-2), was decreased in the HT1080 cells, indicating that the decrease in the expression level of SOD was due to the antioxidant effect of graphene. These results suggest that the inhibitory effect of oxidative stress in the presence of graphene could inhibit the expression of MMPs in HT1080 cells. Based on the above results, graphene may have chemoprevention properties through inhibition of MMP-2 and MMP-9 related to metastasis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.46 no.10
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• pp.1178-1185
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• 2017

Two types of kimchi with a different total acidity (TA, 0.75% or 1.19%) were heated at $100^{\circ}C$ for up to 60 min to develop a gratin added with heated-kimchi. Their browning index and color intensity increased with increasing heating time, which was more apparent for the kimchi with the higher TA. This was attributed to the Maillard reaction facilitated at a higher heat intensity and by the smaller fermentation products. The same tendency was also observed for the antioxidant activities determined by the total reducing capacity, metal-chelating activity, and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity. In particular, heating kimchi at $100^{\circ}C$ only for 10 min increased the activities significantly. Therefore, the heated-kimchi was added to gratin at 20%. With the addition, the dietary fiber, ${\gamma}-aminobutyric$ acid (GABA) and ornithine contents in the gratin were increased appreciably (P<0.01). Nevertheless, there was little change in its salinity. The antioxidant activities of the gratin were significantly (P<0.001) higher than the control gratin without kimchi, with DPPH radical scavenging activity being 3.6 times higher. The results suggest that the functionality of kimchi could be effectually added to gratin even after heat treatment.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 1997.11a
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• pp.35-36
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• 1997

복합재는 강도가 높고 가볍기 때문에 최근 로켓의 연소관으로 널리 사용되고 있다. 그런데 이 복합재 로켓 연소관은 제조 후 대기 환경에 장기적으로 노출되어 있기 때문에 금속 연소관과는 달리 온도 또는 습도 등의 환경에 대한 영향을 고려해야 한다. 더구나 연소관은 내부에 추진제가 충전되어 있으므로 추진제의 기계적 특성이 습도에 민감함을 생각할 때 강도뿐만 아니라 습기의 투과도 또한 매우 중요한 고려 요소가 된다. 그러나 온/습도 변화에 따른 복합재 자체의 재료 특성 변화에 대한 연구는 많이 보고되었으나 습기의 투과 정도에 관한 연구는 자료가 미흡한 실정이다. 한편, 포화 함수율은 복합재에 따라서 차이가 있으나 T300/5208의 경우 문헌을 참조하면 20-$50^{\circ}C$에서 복합재 무게의 약 1.5% 정도이며 포화에 걸리는 시간은 약 100일 정도로 나타나 있다.본 연구에서는 수분이 복합재를 통하여 투과되는 정도를 고찰하기 위하여 $20^{\circ}C$,95%RH의 온/습도를 유지하는 수조를 제작하였고, 이 수조내에 보관한 복합재 연소관의 실린더 벽면으로 투과되는 습기를 측정하기 위하여 연소관 내에 습도 센서를 투입하여 상대습도를 직접 측정하였다. 복합재 연소관이 로켓에 사용될 때는 연소관 외부에 페인트로 피막 처리하고 연소관 내부에도 추진제와의 사이에 라이너가 접착되어 있어서 수분 침투 및 온도 등의 외부 환경조건에 견디기에 더 양호한 조건이나 본 연구에서는 복합재 자체의 특성을 고찰하기 위하여 섬유를 에폭시에 함침시켜 winding한 상태 그대로의 복합재 연소관 시료를 사용하였다. 습기의 투과는 내부에 라이너/인슐레이션이 피복되거나 또는 추진제가 충전된 경우 많은 감소효과를 보였다. 순수 복합재 연소관의 경우 수조에 넣고 평형에 도달한 후로부터 약 8개월의 습기 투과 상태를 볼대 벽면을 통하여 들어가는 water vapor flux는 $20^{\circ}C$,95%RH 에서 평균적으로 9.3163$\times$$10^{-8}$g/$m^2$sec로 나타났다. 이때 습기가 투과되는 연소관이 국지점을 평판으로 가정하고 Fick's law를 이용하여 구한 습기에 대한 복합재의 확산계수는 D=2.5$\times$$10^{-6}$$mm^2$sec였으며, 이는 다른 graphite/epixy 복합재의 확산계수와 유사한 값을 나타내고 있다. 또한 추진제가 충전된 연소관을 절단하여 밀폐한 후 95%RH 습도 조건에 보관함으로써 연소관 내부의 추진제 기계적 특성에 미치는 침투된 습기의 영향도 함께 고찰하였다. 추진제에 따라 차이는 있겠으나 추진제가 충전된 연소관은 순수 복합재 연소관에 비해 습기의 투과 정도가 작으며, 본 연소관에 충전된 RDX/AP계 추진제의 경우 추진제의 습기투과에 의한 추진제 물성 변화는 미미한 것으로 나타났다.

• Journal of Life Science
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• v.26 no.6
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• pp.673-679
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• 2016

The development of safe and effective anti-cancer compounds has been seriously required to prevent and treat development of tumor in recent years. Among them, natural compounds derived traditional medicinal stuffs have been paid to attention as an anti-cancer candidate. In this study, aesculetin is a main component of a widely known as a medicinal stuff. It was reported that aesculetin has various biological effects such as anti-inflammatory and anti-bacterial, but its effect related to cell invasion was not discovered. Therefore, in this study, the effect of aesculetin on antioxidant and matrix metalloproteases (MMPs) was investigated in human fibrosarcoma cells, HT1080. First of all, aesculetin showed the scavenging activity of DPPH radical and reducing power in a dose dependent manner. As a result of cytotoxicity, the nontoxic concentration of aesculetin was below 2 μM in HT1080 cells performed by MTT assay. In addition, aesculetin displayed the inhibitory effect on MMP-9 activity related to cell invasion in experiment carried out by gelatin zymography assay. Furthermore, aesculetin increased the expression level of TIMP-1 but decreased the expression level of MMP-9 stimulated with PMA in western blot assay. Furthermore, aesculetin remarkably inhibited cell invasion related to metastasis a dose dependent manner. Above results suggest that aesculetin could exert chemopreventive effect through inhibition of activity and expression of MMP-9 related to cell invasion.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.2
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• pp.104-115
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• 2014

Abundance and composition of marine debris on 13 beaches of Tongyeong City, South Korea were surveyed in 2013 Autumn. The average quantity of macro debris (>25 mm) was about 30 particle/$m^2$ and that of micro debris (1 mm-25 mm) was about 26,971 particle/$m^2$. This is a very high level compared with other areas of South Korea and the other countries. Among the 7 material types of debris (styrofoam, hard plastic, fiber, metal, glass, wood and others), styrofoam composed a large portion: 75% of macro debris and 98% of micro debris. And among the 'whole' styrofoam debris items whose original volume is remained more than 50%, styrofoam buoy debris composed 93%. This result suggests that the beaches surveyed are seriously contaminated by marine debris, and most of its sources are aquaculture styrofoam buoys. Management of styrofoam buoy debris used for oyster aquaculture in Tongyeong City is important not only for Tongyeong city, but also for other areas, because Tongyeong city hosts the biggest number of oyster aquaculture areas in South Korea.

• Journal of the Korean Society for Nondestructive Testing
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• v.34 no.2
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• pp.155-164
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• 2014

Carbon-fiber-reinforced plastic (CFRP) composites are increasingly being used in a variety of industry applications, such as aircraft, automobiles, and ships because of their high specific stiffness and high specific strength. Aircraft are exposed to high temperatures and high humidity for a long duration during flights. CFRP materials of the aircraft can absorb water, which could decrease the adhesion strength of these materials and cause their volumes to change with variation in internal stress. Therefore, it is necessary to estimate the characteristics of CFRP composites under actual conditions from the viewpoint of aircraft safety. In this study air-coupled ultrasonic testing (ACUT) was applied to the evaluation of water absorption properties of CFRP composites. CFRP specimens were fabricated and immersed in distilled water at $75^{\circ}C$ for 30, 60, and 120 days, after which their ultrasonic images were obtained by ACUT. The water absorption properties were determined by quantitatively analyzing the changes in ultrasonic signals. Further, shear strength was applied to the specimens to verify the changes in their mechanical properties for water absorption.

• The Korean Journal of Mycology
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• v.49 no.2
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• pp.199-209
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• 2021

The present study was performed to improve the technique used for fermenting the mushroom growth medium. Taxonomic analysis of 16S rDNA sequence from the predominant Bacillus strain CY-24 isolated during the fermentation phase of the rice straw medium identified it as Bacillus licheniformis. In addition, the growth environment of B. licheniformis was also examined in this study, which revealed the optimal growth temperature and pH to be 30 ℃ and 6.0, respectively. This study also revealed that carboxymethyl cellulase (CMCase) and polygalacturonase (PGase) enzymes isolated from B. licheniformis achieved their maximal activities at 50 ℃ and 60 ℃ respectively. Furthermore, the study confirmed that the two enzymes, i.e., CMCase and PGase in B. licheniformis are stable at temperatures above 60 ℃. The present study thus demonstrates that B. licheniformis CY-24 possesses excellent enzymatic properties. It also reveals that the action of enzymes during the production of growth mediums used for the cultivation of mushrooms is closely associated with the promotion of fermentation and softening of the rice straw. Overall, this study provides elementary information regarding the role of B. licheniformis enzymes during growth medium fermentation for Agaricus bisporus cultivation.

• Journal of the Korean Electrochemical Society
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• v.22 no.3
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• pp.87-103
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• 2019

Nonaqueous organic electrolyte solution in commercially available lithium-ion batteries, due to its flammability, corrosiveness, high volatility, and thermal instability, is demanding to be substituted by safer solid electrolyte with higher cycle stability, which will be utilized effectively in large-scale power sources such as electric vehicles and energy storage system. Of various types of solid electrolytes, composite solid electrolytes with polymer matrix and active inorganic fillers are now most promising in achieving higher ionic conductivity and excellent interface contact. In this review, some kinds and brief history of solid electrolyte are at first introduced and consequent explanations of polymer solid electrolytes and inorganic solid electrolytes (including active and inactive fillers) are comprehensively carried out. Composite solid electrolytes including these polymer and inorganic materials are also described with their electrochemical properties in terms of filler shapes, such as particle (0D), fiber (1D), plane (2D), and solid body (3D). In particular, in all-solid-state lithium batteries using lithium metal anode, the interface characteristics are discussed in terms of cathode-electrolyte interface, anode-electrolyte interface, and interparticle interface. Finally, current requisites and future perspectives for the composite solid electrolytes are suggested by help of some decent reviews recently reported.

• Composites Research
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• v.32 no.5
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• pp.284-289
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• 2019

In the present paper, the dynamic force-moment equilibrium equations, driving power and energy equations are analyzed to formulate the equation for fuel economy(km/liter) equivalent to the driving distance (km) divided by the fuel volume (liter) of the vehicle, a selected model of gasoline powered KIA K3 (1.6v). In addition, the effects of the dynamic parameters such as speed of vehicle (V), vehicle total weight(M), rolling resistance ($C_r$) between tires and road surface, inclined angle of road (${\theta}$), as well as the aerodynamic parameters such as drag coefficient ($C_d$) of vehicle, air density(${\rho}$), cross-sectional area (A) of vehicle, wind speed ($V_w$) have been analyzed. And the possibility of alternative materials such as lightweight metal alloys, fiber reinforced plastic composite materials to replace the conventional steel and casting iron materials and to reduce the weight of the vehicle has been investigated by Ashby's material index method. Through studies, the following results were obtained. The most influencing parameters on the fuel economy at high speed zone (100 km/h) were V, the aerodynamic parameters such as $C_d$, A, ${\rho}$, and $C_r$ and M. While at low speed zone (60 km/h), they are, in magnitude order, dynamic parameters such as V, M, $C_r$ and aerodynamic ones such as $C_d$, A, and ${\rho}$, respectively.