• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.249-249
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• 2011

투명전도성산화물(transparent conducting oxides, TCOs) 박막은 전기 전도성과 광투과성이 우수하여 유기발광다이오드(organic light-emitting diode, OLED), 태양전지(solar cell), 발광다이오드(LED) 등의 광전자 소자에 널리 응용되고 있다. 특히 LED에서 p-GaN층에서 전류가 층안에서 충분하게 확산되지 않기 때문에, TCO는 균일하게 전류를 흘려보내기 위해서 전류확산층(current spreading layer)으로 사용된다. 그 중 널리 쓰이는 산화인듐주석(indium tin oxide, ITO)은 고가의 indium가격과 인체에 유해한 독성 등이 문제점으로 지적되고 있다. 따라서 indium의 함량을 저감하거나 함유하지 않은 새로운 조성의 친환경적 대체 TCO 개발에 대한 연구가 많이 진행되고 있다. 이러한 반도체 재료 중 하나인 AZO (Al-doped zinc oxide, Al2O3 : 2wt.%)는 3.3 eV의 넓은 에너지 밴드갭을 가지며, 가시광선 및 근적외선 파장영역에서 높은 투과율을 나타낸다. 따라서 본 연구에서는 GaN기반 LED 응용을 위한 전류확산층으로 ITO 대신 AZO의 특성을 연구하였다. 박막 증착율이 높고, 제작과정의 조정이 용이한 RF magnetron 스퍼터를 이용하여 glass기판 위에 AZO, Ni/AZO, NiOx/AZO를 증착하였다. 이어서 $N_2$ 분위기에서 다양한 온도 조건에서 열처리(rapid thermal annealing, RTA)하여 전기적 광학적 특성에 대하여 비교 분석하였다.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.02a
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• pp.101-101
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• 2011

투명전도성산화물(transparent conducting oxides, TCOs) 박막으로써 널리 쓰이는 산화인듐주석(indium tin oxide, ITO)은 전기 전도성과 광 투과성이 우수하여 주로 유기발광다이오드(organic light-emitting diode, OLED)의 전극, 발광다이오드(light-emitting diode, LED)의 current spreading 층 및 태양전지(solar cell)의 윈도우층(window layer) 등의 광전자 소자로 응용되고 있으나, 고가의 indium 가격과 인체에 유해한 독성 등이 문제점으로 지적되고 있다. 따라서 indium의 함량을 저감한 새로운 조성의 TCO 또는 indium을 함유하지 않은 친환경적인 TCO 대체 재료 개발의 필요성이 증대되고 있다. 이러한 재료 중 하나인 AZO (Al-doped zinc oxide, $Al_2O_3$: 2 wt.%)는 3.82eV의 넓은 에너지 밴드갭을 가지며, 가시광선 및 근 적외선 파장 영역에 대하여 90% 이상의 높은 투과율을 나타낸다. 또한, 습식식각이 가능하며, 매우 풍부하여 원가가 매우 저렴하고, 독성이 없다. 본 연구에서는 박막 증착율이 높고, 제작과정의 조정이 용이한 RF magnetron 스퍼터를 이용하여 glass 기판 위에 AZO 박막을 성장하고, $N_2$ 분위기에서 다양한 온도 조건에서 열처리(rapid thermal annealing, RTA)하여 전기 및 광학적 특성에 대하여 비교 분석하였다. 또한, 이후에 기존의 성장방법과 달리 고가의 진공 장비를 사용하지 않고, 저온에서도 간단한 구조의 장비를 이용하여 균일한 나노구조를 성장시킬 수 있는 전기화학증착법(electrochemical deposition)으로 AZO 박막위에 ZnO 나노로드를 다양한 성장조건에 따라 성장시켜 광학적 특성을 비교 분석하였다.

• Proceedings of the KIEE Conference
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• 2001.10a
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• pp.254-257
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• 2001

This paper is managing about problem and EMI by electromagnetic waves occurrence of electrical appliances and harmfulness of EMS and standard. Specially, because this paper certifies a mouse and electromagnetic waves interception effect of electricity market place which possess electromagnetic waves interception facility, there is effect that contribute in health life that do to secure safe going to sleep condition from electromagnetic waves of electricity market place that is security of computer working environment of safe state through electromagnetic waves interception and essential electric appliance of home life.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.83-83
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• 2009

우수한 압전성을 가지는 PZT는 인체에 유해한 다량의 PbO을 함유하여 심각한 환경문제를 야기함은 물론 제조 공정 중 PbO 휘발 억제 시설 구비에 따른 경제적 부담 등 문제점이 지적되었다. 따라서 환경오염 및 가격경쟁력을 갖추기 위해 현재 무연 조성 세라믹스에 대한 많은 연구가 진행되고 있다. 최근 비납계 압전 세라믹의 연구는 비스무스 레이어형과 페로브스카이트 형 비납계 세라믹스의 연구가 활발히 진행되고 있다. 특히 $(Na,K)NbO_3$ 계는 페로브스카이트 구조를 가지는 비납계 세라믹으로 현재 많은 연구가 진행되고 있다. 이 물질은 PZT계와 유사하게 상전이(morphotropic phase boundary:MPB)영역을 가지고 있 으며 이 영역에서 높은 압전 특성을 보여주고 있다. 최근 $Na_{0.5}K_{0.5}NbO_3$에 $LiTaO_3$를 치환하여 우수한 압전 특성을 지니는 조성이 개발되고 있지만, 보통 소성법으로 제조된 세라믹스는 PZT계 세라믹스와 비교하여 특성이 떨어진다. 본 연구에서는 압전성이 우수한 $(Na_{0.44}K_{0.52}Li_{0.44})(Nb_{0.90}Sb_{0.06}Ta_{0.04})O_3$ 조성에 도너 도핑과 억셉터 도핑을 한 다음 전기기계결합계수, 압전상수, 유전상수의 변화를 평가하고, hardener 와 softener 특성이 본조성에서 나타나는지를 관찰하였다. 실험방법은 보통 소성법을 사용하였으며, 분쇄와 혼합은 직경 3 mm zirconia ball을 사용하여 볼밀 하였다. $850^{\circ}C$ 에서 5h 하소 후 $1100{\sim}1200^{\circ}C$ 에서 소결하고, 두께 1 mm로 연마한 다음 silver paste를 $650^{\circ}C$ 에서 소부하여 전극을 형성하였다. 제작된 시편은 $90^{\circ}C$의 실리콘유에서 3~4 kV/mm의 전계를 가해 20분간 분극 처리를 수행하였다. 제작된 시편의 압전전하 상수 값은 d33-meter(APC-8000)를 이용하여 측정하였고, 유전율, 전기기계결합계수 및 기계적품질계수 등은 임피던스 분석기 (impedance/gain phase analyzer)를 이용하여 특성을 측정 하였다. 또한 전압-분극 특성의 평가에는 강유전특성 측정기(ferroelectric tester: Precision-LC, Radiant Technologies, USA)를 이용하였다.

• Korean Journal of Optics and Photonics
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• v.25 no.6
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• pp.315-325
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• 2014

A combination of MHL and LED fish-luring light is used in this study. Its yield, characteristics, and irradiance distribution are evaluated and analyzed. To obtain an irradiance distribution similar to that of an MHL, we suggest the optimal arrangement of MHL and LED.

• Journal of the Korean Society of Marine Environment & Safety
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• v.24 no.2
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• pp.275-281
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• 2018

It is known that he pollutant emitted from the combustion process of marine fuel oil causes air pollution and harmful effects to the human body. Accordingly, IMO regulates pollutants emitted from ships. However, the regulation of Particulate Matter (PM) is still in the process of debate, so preemptive action is needed. Fundamental research on PM is essential. In this study, the Dimensionless Light Extinction Constant ($K_e$) of fuel oil used in marine diesel engines was measured and analyzed to construct the basic data of the PM generated from marine-based fuel oil. The fuel oil used in the land diesel engine was measured in the same way for character comparison. Both fuel oils differ in sulfur content and density. The $K_e$ was measured via the optical method using a 633 nm laser and was determined by using the volume fraction of PM collected by the gravimetric filter method. The $K_e$ of the PM discharged from marine fuel oil is 8.28, and the land fuel oil is 8.44. The $K_e$ of two fuel oils was similar within the measurement uncertainty range. However, it was found by comparison with the value obtained by the Rayleigh-Limit solution that the light scattering portion could be large. Also, it was found that light extinction characteristics could be different due to the relationship between light transmittance and collected mass.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.509-515
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• 2004

Photodynamic therapy(PDT) has advanced to clinical trials for the treatment of a variety of solid tumors and presents an alternative treatment option for tumors resistant to chemo-and/or radio-therapy. PDT is based on the combination of laser light of appropriate wavelength and energy to activate a systemically or locally applied photosensitizer that concentrates preferentially in malignant tissues. In this study, phototoxicity of laser EIT 21 was analysed in human osteosarcoma cell(HOS) and the second objective of this study was to determine the ability of laser EIT 21 to induce apoptosis. This study demonstrated that laser EIT 21 had a phototoxicity to HOS cells. In order to examinate whether cell death was induced by necrosis or apoptosis, variety of techniques which assess apoptosis were used. TUNEL assay showed only a few the positive reaction on condensed nuclei. It is hard to find condensed or fragmented nuclei on HOS cells irradiated with laser EIT 21 in Hemastat and AO/EB stain. By DNA electrophoresis, cells also did not show DNA degradation characteristic of apoptosis with a ladder pattern of DNA fragments. Apoptosis-related factors were analyzed by western blotting. The expression of p53 was constant and cells irradiated with laser did not show the caspase-3 and PARP degradation, therefore we suggest that p53 and caspase-3 are not involved in laserinduced cell death.

• Korean Journal of Environmental Agriculture
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• v.28 no.3
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• pp.310-325
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• 2009

Veterinary drugs have been used to prevent livestock diseases for many years. In spite of having advantages, sometimes indiscriminate application, overdose and abuse may cause risk for human. Therefore, management and risk assessment of veterinary drugs become essential to ensure food safety. So the National Veterinary Research & Quarantine Service (NVRQS) impose on registration for use of veterinary drugs also Korea Food and Drug Administration (KFDA) fixed the maximum residue limits (MRLs) for veterinary drugs in food. Basically, KFDA set MRLs based on the veterinary drugs residual data. Moreover, KFDA estimates the theoretical maximum daily intake (TMDI) with food consumption data and population mean body weight. Recently, 116 veterinary drug MRLs including banned veterinary drugs have been established and other 32 veterinary drugs MRLs will be established within 2009. In 2010, MRLs among antibiotics and synthetic antibacterial agents in livestock fishery products (including milk and eggs) and honey (including royal jelly and propolis) which have not been set in Korea Food Code and Codex Alimentarius Commission (CAC) will be regulated as uniform limit (0.03 mg/kg). In future, veterinary drugs will be controlled strictly to strengthen public health by improving analytical method.

• Journal of Industrial Convergence
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• v.18 no.1
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• pp.45-52
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• 2020

This study is a descriptive study conducted to investigate the effect of smoking cigarette sign sold in Korea on the smoking cessation effects and to use it as a basis for future smoking cessation and health related health data. To this end, we surveyed 500 men and women over 20 years of age on the Internet Naver web using Naver form questionnaire for 10 days from October 1, 2018 using blogs and cafes. The analyzed data were analyzed by factor analysis, T-test and correlation using SPSS WIN20.0. The main findings were as follows: First, the cigarette warning picture harmful to human body had the biggest influence on the smoking cessation effect. Second, the smoking cessation effect had the highest correlation with the pre-question consciousness about the cigarette warning picture. This indicates that the cigarette pack warning is considered the most sensitive part of smokers. Based on the results of this paper, diversification of cigarette warning picture and regular replacement of warning picture are expected to provide useful basic data for suggesting practical measures to prevent smoking. do. Therefore, the smoking warning picture is widely promoted through the media and the media, which has a positive effect on the practice of quitting smoking to the public, and is also used as a basic data for the health policy for the health promotion of the public.

• Journal of Animal Science and Technology
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• v.49 no.6
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• pp.819-828
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• 2007

Two experiments were conducted to observe the effects of direct fed microbials on metabolic characteristics in sheep and milking performance in dairy cows. A metabolic trial with four ruminally cannulated sheep(60±6kg) was conducted in a 4×4 Latin square design to investigate the supplementation effects of Saccharomyces cerevisiae, Clostridium butyricum or mixed microbes of S. cerevisiae and C. butyricum on ruminal fermentation characteristics and whole tract digestibility. Sheep were fed 1.25 kg of total mixed ration(TMR, DM basis) supplemented with S. cerevisiae (2.5g/day), C. butyricum (1.0g/day) or its mixture(S. cerevisiae 1.25g/day+C. butyricum 1g/day), twice daily in an equal volume. But control sheep were fed only TMR. A feeding trial with 28 lactating Holstein cattle was also conducted for 12 weeks to investigate the effects of the same microbial supplements as for the metabolic trial on milking performance. The cows were fed the TMR(control), and fed S. cerevisiae(50g/day), C. butyricum(15g/day) or its mixture (S. cerevisiae 25g/day + C. butyricum 7.5g/day) with upper layer dressing method. Total VFA concentration and the digestibility of whole digestive tract in the sheep increased by supplementation of S. cerevisiae, C. butyricum or their combined microbials compare to control group. The proportion of propionic acid at 1h(P<0.039) and 3h(P<0.022) decreased by supplementation of S. cerevisiae while tended to increase acetic acid proportion at the same times. Daily dry matter intake(DMI) was not influenced by the microbial treatments, but milk yield(P<0.031) and feed efficiency(milk yield/DMI, P<0.043) were higher for the cow received C. butyricum than those for other treatments. The milk fat content was higher (P<0.085) when cows fed S. cerevisiae(4.11%) than that fed the control (4.08%), the diets with C. butyricum (3.85%) and the microbial mixture. Based on the results obtained from the current experiments, supplementation of C. butyricum or mixture with S. cerevisiae might be increased milk fat content and milk productivity of lactating daily cows. (Key words:Saccharomyces cerevisiae, Clostridium butyricum, Fermentation characteristics,