• The Korean Journal of Food And Nutrition
• /
• v.30 no.2
• /
• pp.211-217
• /
• 2017

In the present study, we investigated the protective effect of various grain methanolic extracts against UVB-induced photo-aging in human skin fibroblasts. Various grain methanolic extracts were evaluated for their antioxidant compounds and activities. 2,2-Ddiphenyl-1-picryhydrazyl radical (DPPH) and ABTS 2,2-azino-bris-(3-ethylbenzoth iazoline-6-sulphonic acid) radical cation scavenging activities have been used to measure the relative antioxidant activities of extracts from grains. The content of total polyphenolics in the extracts were evaluated using spectrophotometric methods. Human skin fibroblast (Hs68) cells were pretreated with various grain methanolic extracts ($25{\mu}g/mL$). Skin toxicity was simulated by exposing the cells to UVB ($30mJ/cm^2$) irradiation. In response to the UVB-irradiation, an increased amount of matrix metallo-proteinases (MMPs) release was observed, whereas pretreatment of various grain methanolic extracts significantly inhibited the production of MMP-1 in Hs68 cells. We also found that pretreatment of the extracts significantly decreased UVB-induced reactive oxygen species and significantly increased total collagen content in Hs68 cells. These results provide that grains could be regarded as a potential ingredient in natural cosmetics, used for UVB protection.

• Korean Journal of Microbiology
• /
• v.50 no.2
• /
• pp.128-136
• /
• 2014

Acyl homoserine lactone (AHL) lactonase has been proved to be the AHL-degrading enzyme with the highest substrate specificity for AHL molecules and has shown a considerable potential as low-cost and efficient quorum quenching (QQ) technique. However, few studies focused on its inhibitory effect on biofilm formation which is also a quorum sensing (QS)-regulated phenomenon. In this study, QQ activity of six isolates from biofouled reverse osmosis membranes was studied using Chromobacterium violaceum CV026 and Agrobacterium tumefaciens NTL4 as biosensors under various conditions. All of the isolates belonged to the genus Bacillus and showed QQ activity regardless of the acyl chain length or substitution of AHL molecule. The isolates were capable of significantly inhibiting biofilm formation (46.7-58.3%) by Pseudomonas aeruginosa PAO1 and produced heat-sensitive extracellular QQ substances. The LC-MS analysis of the QQ activity of a selected isolate, RO1S-5, revealed the degradation of N-(3-oxododecanoyl)-L-homoserine lactone (3-oxo-C12 AHL) and the production of corresponding acyl homoserine (3-oxo-C12-HS), which indicated the activity of AHL lactonase. The broad AHL substrate range and high substrate specificity suggested that the isolate would be useful for the control of biofilm-related pathogenesis and biofouling in industrial processes.

• Electronics and Telecommunications Trends
• /
• v.24 no.6
• /
• pp.22-31
• /
• 2009

전 세계는 온실가스의 배출을 줄이기 위한 방안의 하나로 전 에너지 소비의 약 20%를 차지하고 있는 조명의 고효율화를 위한 노력을 다각적으로 벌이고 있으며, 그러한 노력의 일환으로 지난 100년간 사용되어온 백열등이 낮은 효율로 인하여 사용규제 논의의 대상이 되고 있다. 반면, 효율은 백열등의 7~8배인 형광등은 높은 효율에도 불구하고 수은과 납이 함유되어 중금속 사용규제(RoHs, WEEE)로 인하여 그 사용이 규제될 계획이다. 따라서, 백열등과 형광등의 빈자리를 채울 수 있는 친환경 차세대 조명에 대한 수요가 확대되고 있어 LED, OLED와 같은 반도체 조명에 대한 개발이 확대되고 있다. 본 기고서에서는 차세대 조명 중에서 OLED 기술을 기반으로 한 OLED 조명 기술과 선진국 및 선진산업체의 개발 동향을 소개하고자 한다.

• Journal of the Microelectronics and Packaging Society
• /
• v.22 no.3
• /
• pp.1-7
• /
• 2015

In this study, properties of Pb-free solders for automotive electronics parts were discussed. Lead-free solders for electronics became important after RoHS (Restriction of the use of certain Hazardous Substances) to avoid environmental pollution. Also the growing electronic rate in automotive parts and ELV (End-of Life Vehicles) make Pb-free solder for automotive electronics to be inevitable trend. Definitely, Pb-free solder for automotive electronics should have good wettability, basic strength, but need more reliability than other solders, since it has harsh condition like high temperature, humidity and engine vibration. Thus, shear strength test, thermal shock, drop test and many others are needed to ensure the high reliability. This study describes the properties and requirements of Pb-free solders for automotive electronics.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2016.11a
• /
• pp.167.2-167.2
• /
• 2016

금(Au) 및 금의 합금도금은 주로 극히 얇고 색상만 나타내는 정도의 장식용으로 많이 사용되고 있으나 단순한 장식품뿐만 아니고 스마트폰, 정보통신 서버, 전자기기, 자동차, 전지용에도 널리 사용되고 있다. 특히 로켓공업이나 인공위성의 와곽부, 엔진에는 필수적이다. 현재 미국의 금도금액 85%는 전자부품과 인공위성(NASA) 등의 공업용에 사용되고 있다. 금도금의 이용가치는 주로 내식성이며 전기저항이 작고 열전도성이 뛰어나 전기접전부에 필수적으로 사용해야만 한다. 또한 2007년 유럽의 RoHS규정에 의해 피부에 접촉하는 팔찌, 귀걸이, 목걸이, 반지 등의 디자인 액세서리 제품에 있어서도 종래의 6가 크롬이나, 납, 수은, 카드뮴 사용이 금지되었다. 종래의 산성, 알칼리성, 중성 금도금에서는 주로 시안(Cyan) 기반의 전처리 탈지액이 사용되고 있어 작업환경에도 유해하며 생산성 감소로 이어지고 있다. 이에 전해 금도금 전처리 탈지공정을 개선함으로써 품질불량 20%감소와 함께 작업환경 개선으로 생산성 30%향상을 기대할 수 있다.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.05a
• /
• pp.62-67
• /
• 2002

While upwelling regions account for only 0.1% of the ocean surface, they yield over 40% of world's fish catch. Thus it is vary important making upwelling region by various methods. This study was performed to find out basic hydrodynamic characteristics (function, stability..,) of artificial upwelling structures. The hydrodynamic characteristics of artificial upwelling structures can be summarized as follows: 1) The falling velocity of blocks was effected size($l_B$) of blocks than incident current velocity( $V_0$). 2) The falling horizontal distance was reduced as induce of stratification parameters and block' size. 3) Generation of artificial upwelling current was effected by size of structures and incident current. When stratification parameters was about 3.0 and relative height(hs/h) of structures was about $0.125{\sim}0.15$, stable artificial upwelling current was generated in the back-side of structures.

• 한국정보통신설비학회:학술대회논문집
• /
• 2007.08a
• /
• pp.235-237
• /
• 2007

Concerns on environmental issues and global warming are increasing worldwide. Environmental regulations such as Tokyo Protocol, RoHS, WEEE are also getting harder and harder and used as trade barriers. Different from other manufacturing industries, information and communication industry is basically environment friendly-low emission of harmful materials and little consumption of energy. But information and communication industry can contribute to world environment by recycle articles in disuse and properly process discarded trash. Furthermore, by using more renewable energy, it can reduce the $CO_2$ emission, one of the major the green house gas.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
• /
• 2007.05a
• /
• pp.160-165
• /
• 2007

형광램프와 HID(high intensity discharge)램프는 수은(Hg)에 의해 빛을 방사한다. 산업환경의 변화속에서 침체기를 맞고 있는 국내 조명산업이 내부적으로는 친환경 조명제품 개발에 주력하고 외부적으로는 환경규제로 인한 피해를 최소화시킴과 동시에 적극적인 세계시장공략으로 고부가가치산업으로 성장할 수 있도록 조명분야의 환경규제 동향을 조사하여 조명산업 전반에 널리 홍보함으로써 국내 조명산업의 지속적인 경쟁력 및 성장가능성 확보에 목적을 두고 있다. 선진국을 중심으로 제도화되고 있는 환경규제(RoHS. WEEE 등)에 따른 문제점과 예상 영향(피해)도를 조사, 분석하여 시기적절한 효율적인 발전방안을 모색함으로써 국내 조명산업의 지속적인 경쟁력 및 성장가능성 확보를 위한 조명산업 발전방안 제시에 목적을 두고 있다.

• Proceedings of the Safety Management and Science Conference
• /
• 2006.11a
• /
• pp.361-365
• /
• 2006

Air pollution problem has been one of the most urgent global environmental problems since UN Framework Convention on Climate Change accepted in Rio Conference, 1992. International environmental regulations of global community to reduce the green house gases have Influenced the domestic environmental policies. Recently, various policy have been made to cope with foreign environment restrction and active supports for development of related technology have been carried out in our government confrontation strategy still leaves much to be desired. In this paper, government confrontation program to climate agreement, counter strategies in motor and also electrics, electronics industries are investigated and discussed.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
• /
• 2002.10a
• /
• pp.277-282
• /
• 2002

This study was performed to find out basic function of artificial upwelling structures. Generation of artificial upwelling current was affected by size of structures, incident current and porosity. when stratification parameters was about 3.0, relative height(hs/h) of structures was $0.125{\sim}0.15$, stable artificial upwelling current was generated in the back-side of structures. when porosity is lower than 50%, the effect of artificial upwelling structure was to be better than little by little.