• The Korean Journal of Pesticide Science
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• v.19 no.1
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• pp.1-4
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• 2015

The current official perfluorochemicals (PFCs) analysis method is established with hydrophilic-lipophilic balance (HLB) solid phase extraction (SPE) clean-up method with LC-tandem mass spectrometry ($MS^n$). Herein the HLB clean-up method from the official method by Korean government was modified with Envi-Carb$^{TM}$ to improve the clean-up efficiency for agricultural water and the unexpected UV disturbance in the water was effectively removed by the adsorbent treatment without a significant disturbance of quantitation. And quadrupole time of flight mass spectrometry (qTOFMS) was suggested to the available $MS^n$ instruments for the residue analysis of PFCs based on the ng/L of quantitation limits in water as well.

• Journal of Surface Science and Engineering
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• v.49 no.3
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• pp.280-285
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• 2016

In this study, we investigated the influences of potassium fluoride(KF) addition on the surface characteristics of plasma electrolytic oxidation(PEO) coating produced on Al alloy. The PEO of marine grade Al alloy(5083 grade) was conducted in KOH 1g/L solution adding different concentrations of KF(0, 1 and 2 g/L) under a galvanostatic regime. With KF addition, unusual behavior was observed on the voltage-time characteristic curves, which can be characterized by the following process: (i) initial rapid increase in voltage (ii) a short plateau after 1st breakdown (iii) gradual increase in voltage (iv) intermittent fluctuation of voltage after 2nd breakdown. The SEM observation revealed irregular surface morphology with KF addition, as compared with one formed without KF addition, which had a reticulate structure. The XRD analysis detected the formation of aluminium hydroxide fluoride hydrate($H_{4.76}Al_2F_{3.24}O_{3.76}$) on surface grown by PEO process with KF. Particularly, at very early stage of the process (~ 120 s), thin film was formed having nanoporous structure, and F element was confirmed on surface by EDS analysis. The thickness and surface roughness of the coating increased with increasing KF concentration. As a result, KF addition was found to be less beneficial influences on PEO of marine grade Al alloy, and therefore needs further research to improve its capability.

• Korean Journal of Microbiology
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• v.25 no.4
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• pp.282-289
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• 1987

The characteristics of the plasmid pKU10 isolated from Pseudomonas putida KU816 were investigated and its restriction map was constructed. The pKU10 plasmid was a small R plasmid carrying genes for resistance to ampicillin, tetracyclin, and chloramphenicol, and cured by treatment with mitomycin C. The molecular size of pKU10 was estimated to be 9.4Kb. Pseudomonas strains and E. coli cells could be transformed for antibiotic resistance characters specified by pKU10 plasmid DNA. By incompatibility test with other plasmids, pKU10 is grouped into IncP-1. EcoRI, XhoI, SalI, BglII, and SmaI cleaved pKU10 once, while PstI cleaved at two sites, and HindIII cleaved at six sites. The restriction map was constructed by partial and complete digestion of the purified plasmid DNA with single, double, or triple restriction enzymes. Thus, pKU10 is expected to be used for a cloning vector in Pseudomonas cells.

• Conservation Science in Museum
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• v.14
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• pp.13-22
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• 2013

The Nectar Ritual Painting(Jeung7551) in National Museum of Korea is estimated to have been produced in the 16th century. Ezimagodo who is the head priest of Ruganji in Kyoto, Japan donated this painting in 2010. Overall, damages were serious, such as missing, staining, folding, insects of the face and mounting silk, therefore, it need to conservation treatment. The treatment of conservation in painting was removing surface stains and repairing missing area. It was mounted by following the original form. The analysis result of textile in mounting and support fiber used silk and hemp in microscope. Pigments in paint were divided into six color types. This painting was used that vermilion(cinnabar) and red lead for red color, litharge(massicot) and gold for yellow color, lead white for white color, malachite for green color, azurite for blue color, and carbon black(chinese ink) for black color.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.368-368
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• 2019

경제의 발전과 더불어 사회가 복잡해지면서 재난의 발생은 다양한 형태로 더욱 복잡하게 발생하고 있다. 최근들어 매년 발생하는 가뭄과 기후적 특성으로 인한 유량의 변동성으로 인해 수질오염이 심해지기를 반복하고 있다. 특히, 산업단지나 화재 등 여러 가지 원인으로 인해 수질오염사고도 빈번하게 발생하고 있으며 심한 경우 취수원의 취수중단과 같은 심각한 상황을 발생하기도 한다. 최근들어 심각한 가뭄과 폭염으로 인해 취수원의 수질이 악화되는 사고들이 발생하고 있으며, 과거 수질오염사고를 살펴보면 1991년에 낙동강에서 발생한 구미 두산전자의 페놀방류에 의한 사고로 18시간 동안 대구에 취수가 중단된 적이 있으며, 1994년 대구광역시 성서공단에서 배출된 유기용제에 의해 낙동강 수계 5개 정수장이 취수가 중단된 바도 있다. 또한 2008년 김천공단 (주)코오롱 유화에서 방류된 페놀에 의해 대구의 취수원 중 두류, 매곡취수장이 5시간동안 취수가 중단된바 있으며, 2009년 다이옥산 배출, 2015년 구미공단에서 불소, 암모니아성 질소, 1.4 다이옥산 배출사고, 2018년 과불화화합물에 낙동강 수질사고, 운문댐과 가창댐 유역의 가뭄으로 인한 취수정지 상태가 발생하는 등 대구광역시 시민들의 먹는 물에 대한 불안이 끊이지 않고 있다(Peacenews, 2018). 본 연구는 대구광역시의 상수도시설이 재난상황 발생에 따라 취수가 중단되어 물을 생산하는 취수장이 불능상태가 되는 가상의 시나리오를 설정하고 각 정수장에서 용수를 공급할 수 있는 대응에 대해서 검토하였다. 대구시에서 운영하는 정수장은 총 5개이며, 전체 공급량의 60.5%를 낙동강을 수원으로 하는 매곡과 문산정수장에서 취수하고 있다. 가상의 재난상황 시나리오는 각각의 정수장이 재난발생에 따라 운영이 불가능한 경우인 Scenario 1(a)~(e)와 매곡과 문산정수장이 운영불가능한 경우인 Scenario 2를 가정하여 용수공급 대응방안에 대해 검토하였다. 그 결과 Scenario 1(a)~(e)에서는 매곡정수장이 운영이 불가능한 경우 대구광역시 전체의 용수공급 신뢰도 80.4%로 250 lpcd를 공급할 수 있으며, Scenario 2의 경우에는 낙동강 오염사고로 인해 매곡과 문산정수장이 운영이 불가능할 경우 60.4%의 신뢰도로 205 lpcd를 공급할 수 있는 것으로 검토되었다.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.89-89
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• 2019

수환경으로 유출되는 유해화학물질은 독성을 가지고 직접 유출되거나 다양한 매체와 반응하여 화재 및 폭발 등의 사고가 발생한다. 실제로 낙동강 유역에서는 1991년 페놀 유출사고를 시작으로 2009년 구미공단 '1,4-다이옥산' 유출사고, 2014년 11월 경북 봉화군의 황산유출사고 등 크고 작은 사고가 빈번히 발생하고 있으며 작년 6월에는 대구와 부산의 수돗물에서 과불화화합물이 검출되기도 하였다. 이러한 대규모 사고를 방지하기 위해 신속한 오염물의 거동 예측이 가능한 추적모델이 필요하며, 본 연구에서는 수환경으로 유출된 유해화학물질의 추적을 위한 1차원 저장대 모형을 개발하였다. 일반적으로 저장대 모형은 복잡한 하천 구조를 하천의 주 흐름이 존재하는 본류대와 하천 흐름이 정체되는 저장대, 그리고 하상구조로 단순화 하여 나타낸다. 본류대에서는 하천흐름에 의한 이송 및 횡방향 유속차로 발생하는 전단류에 의한 확산이 일어나며, 저장대와의 물질교환으로 발생하는 저장효과와, 하상구조와의 흡착 및 탈착, 그리고 생물화학적 반응 및 휘발이 발생한다고 가정한다. 본류대와 저장대간의 질량교환은 난류유속변동과 농도차에 의해서만 발생한다고 가정하고 오염물질의 이송과 분산과정을 해석한다. 저장대에서는 이송 및 전단류에 의한 확산은 일어나지 않으며, 본류대와의 물질교환으로 발생하는 저장효과와 하상구조로의 흡착, 그리고 생물화학적 반응 및 휘발이 발생한다고 가정하며, 하상구조에서는 본류대 및 저장대와의 흡착 및 탈착만 발생한다고 가정한다. 저장대 모형의 해석을 위해서는 리치(Reach) 별로 본류대 분산계수($K_F$), 본류대 면적($A_F$), 저장대 면적($A_S$), 그리고 저장대 교환계수(${\alpha}$)의 네 가지 저장대 매개변수가 필요하며 본 연구에서 개발된 저장대 모형은 흡탈착, 생물화학적 반응 및 휘발 과정을 모두 고려하여 유해화학물질의 확산 거동을 모의한다. 최적의 리치길이, 흡탈착, 반응 및 휘발 계수를 산정하여 모형의 정확도를 향상시켰으며, 신속하고 정확하게 오염물의 거동을 예측할 수 있었다.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.5
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• pp.377-383
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• 2006

Recently, production and use of Freon substances are restrained due to destruction of ozone layer and grobal warming. In this aspect of environmental problems, the best solution is to use the natural refrigerant such as ammonia. Thus, this study apply the $NH_3$ and R22 to study the performance characteristic from the superheat control and compare the energy efficiency of two refrigerants from the high performance. The condensing pressure of refrigeration system is increased from 1,500 kPa to 1,600 kPa and degree of superheat is increased from 0 to $10^{\circ}C$ at each condensing pressure. As the result of experiment, when comparing the each COP, we knew the $NH_3$ is suitable as the alternative refrigerant of the R22.

• Journal of Sasang Constitutional Medicine
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• v.33 no.3
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• pp.87-94
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• 2021

Objectives The purpose of this study is to examine the meaning of the Soeumin's Softness and Non-softness in the mouth(口中和, 口中不和). Methods We examined The Existing Doctors's using of the Softness and Non-softness in the mouth, and considered Jema Lee's using of the Softness and Non-softness in the mouth. Afterward, we considered the meaning of the Soeumin's Softness and Non-softness in the mouth in 『Donguisusebowon(東醫壽世保元)』. Results and Conclusion 1. Junggyeong Jang used the Softness in the mouth, and he didn't use the Non-softness in the mouth in 『Sanghanlun(傷寒論)』. 2. The Next Generation Doctors used the Softness in the mouth, and they didn't use the Non-softness in the mouth. Especially, Dongwon Lee used the Softness in the mouth as the Knowing the taste of food, and used the Non-softness in the mouth as the Non-knowing the taste of food. 3. Jema Lee used the Softness and Non-softness in the mouth as urgent indicator of the Soeumbyeong diarrhea in 『Gabobon(甲午本)』, and used the Softness and Non-softness in the mouth as classification indicator of the Taeeumbyeong and Soeumbyeong in 『Sinchuckbon(辛丑本)』. 4. The Non-softness in the mouth is Jema Lee's specific term. It means dry of mouth, thirsty and the Non-knowing the taste of food. 5. The change from the Non-softness to Softness in the mouth is recovery indicator of the Soeumin's disease. It is the basis for setting the Drinking water(能飮水) as the Soeumin's igiljeung(二吉證).

• Journal of Convergence for Information Technology
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• v.8 no.6
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• pp.43-48
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• 2018

An etchant capable of forming a circuit in an FTO film that can replace ITO, which depends on full imports, was prepared. The etching solution is composed of 1 to 30% by weight of fluoride, 1 to 20% by weight of acid, 0.5 to 5% by weight of surfactant, 5 to 20% by weight of solvent, 0.5 to 10% by weight of corrosion inhibitor and the balance of water. This etchant can be etched using a dry film, thereby reducing the cost, and is free from bubbles and residue of the etchant. The characteristics of the etchant were etched in a time of 2 minute with a 100 nm thick FTO, and the etchant temperature was maintained at $50^{\circ}C$. An undercut of -0.00364% was obtained when put into a 2 minute etching solution. No harmful substances such as Cd, Pb, Hg and Cr components were measured. The use of FTO in Korea where rare earths do not exist can achieve localization and import substitution effect.

• Journal of Climate Change Research
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• v.4 no.3
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• pp.269-278
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• 2013

Sulfur hexafloride($SF_6$) emission to atmosphere is lower than $CO_2$, but $SF_6$ GWP is 22,800 times lager than $CO_2$. In recent years as restriction of $non-CO_2$ gas has been greatly reinforced, development of environment-friendly technology with $SF_6$ removal is becoming to main issue. This study shows that $SF_6$ used insulator electrical equipment has emission characteristics during the each phase(maintenance, use, diposal), and analyzed $SF_6$ emission reduction technology related phase. The major technology applies maintenance and disposal step is that improvment of gas recovery rate($85{\rightarrow}99%$), manufacturing catalysts, internal inspection of circuit breaker using endoscopy. Using those technolgies can reduce $SF_6$ emission in atmosphere.