• 한국가시화정보학회지
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• 제13권3호
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• pp.20-23
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• 2015

In this experiment, a heterogeneous droplet consisted of de-ionized water and olive oil was made through two 31G injection needles. The injection flow rate was $50{\mu}{\ell}/min$ and the droplet size was 2 mm. The droplet was impinged onto a sapphire plate which was heated up to $300^{\circ}C$ by a heater. Two high speed cameras were used for visualization, and the frame rate was 20,000 fps. A 150W metal halite lamp was used for illumination. The dropping height was fixed to 20 mm and the corresponding Weber number was 10.6 based on water. Due to different boiling points of two liquids, partial boiling features of heterogeneous droplet was observed. At the Leidenfrost condition, micro explosion phenomenon has occurred.

• 천문학회지
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• 제40권4호
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• pp.127-129
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• 2007

It is well known that water vapor maser emission at 22.2 GHz is associated with the earliest stages of both low- and high-mass star formation and it can be considered a reliable diagnostic of their evolutionary state. Bright Rimmed Clouds (BRCs) are clouds that have been compressed by an external ionization-shock front which focuses the neutral gas into compact globules. The boundary layer between the neutral gas and the gas ionized by the incident photons is often called "bright rim" but the clumps are sometimes classified also as speck globules or cometary globules depending on their appearance. Small globules with bright rims have been considered to be potential sites of star formation and have been studied in several individual regions. We present results from high resolution VLA observations searching for new candidates of recent star formation in bright-rimmed clouds/globules associated with IRAS point sources.

• 대한화장품학회지
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• 제18권1호
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• pp.132-149
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• 1992

이 논문은 외관, 안정도, 얇고 균일하게 끈적이지 않는 Film 형성 등의 우수한 특징을 갖고 있기 때문에 Cosmetic preparations의 여러 방면에 응용하고 있는 Microemulsion gel에 관한 것이다. 우리의 연구는 Microemulsion의 Clarifying agent 또는 Coupling agent로 이용되고 있는 Polyol류가 Microemulsion에 미치는 영향을 해명함으로써, Consistency, Stability, Clarity, Pick-up from a container등이 우수한 최적의 Microemulsion gel의 형성 조건을 확립하여 Cosmetic preparations에 응용할 수 있도록 하는 것이다. 연구한 System은 De-ionized water, Oil로는 Polar한 Ester oil, Emulsifying agent는 Nonionic syrfactant, Coupling agent는 Polyol로 구성하였으며, Three component phase diagram과 Tetrahedral phase diagram을 이용하여, Polyol의 비율에 따라 Microemulsion gel의 투명 영역, Consistency, 충격에 의한 Resonance 효과, Pick-up from a container등의 변화를 고찰하였다. 연구결과 구성 성분 중 De-ionized water의 Coupling agent의 비율변화에 의한 영향이 가장 크게 나타났으며, Coupling agent로 사용된 Glycerine의 물에 대한 비율이 63-75%일 때 최적 Microemulsion gel 형성 영역이 가장 넓게 나타났다. 특히 Polyol의 비율을 적절히 선택함으로써, 최근 관심이 모아지고 있는 최소의 유화제량으로 최대의 유상량을 함유한 Microemulsion gel을 얻는데 기여할 수 있을 것으로 생각된다.

• Applied Microscopy
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• 제39권4호
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• pp.311-317
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• 2009

본 연구는 투어마린 소재와 전기적인 방전을 통해 물의 성질을 변화시킨 투어마린이온활성수를 이용하여 간보호 효과, 비만 예방 효과, 숙취제거 효과를 확인하기 위해 시행되었다. 고지방식이로 비만을 유도한 ICR 마우스에서 투어마린이온활성수를 급이한 실험군은 정수물을 급이한 대조군과 비교하여 사료섭취량이 비슷하고 음수량이 더 적었지만 체중증가는 대조군에 비하여 억제되어 13주에는 유의한 차이를 보여줌으로써 비만 예방 효과를 나타내었다(P<0.05). 사염화탄소로 간독성을 유발시킨 생쥐를 이용하여 간보호 효과를 관찰한 실험에서, 실험군의 aspartate aminotransferase (AST)와 alanine aminotransferase (ALT)는 대조군과 비교하여 평균적인 차이를 나타내었으며, 간의 조직학적 관찰에서 괴사를 비롯한 병리학적 병변이 감소한 것으로 나타났다. S-D rats을 이용한 숙취 실험에서는 실험군이 대조군에 비해 혈중알콜농도가 유의하게 낮았으며(P<0.01), 알콜 대사와 관련된 항산화 효소인 glutathione-S transferase (GST)는 활성이 증가한 것으로 관찰되었고(P<0.05), 간기능 지표인 AST와 ALT는 상대적인 감소현상을 보였다. 이와 같은 결과는 투어마린이온활성수의 음용이 동물의 항산화 체계에 영향을 미침으로써 간조직을 보호하고 알콜 분해를 향상시킨 것으로 판단되며, 그 결과 숙취해소에 어느 정도 효과가 있을 것으로 판단된다. 투어마린이온활성수의 효능과 관련된 기전은 아직 과학적 검증에 어려움이 있으나, 물에 전달된 투어마린의 원적외선에너지나 전기적 영향으로 인하여 물분자의 결합력과 분자 구조 또는 클러스터의 크기에 변화를 일으켰기 때문으로 판단된다. 사용된 투어마린이온활성수는 음용안전성이 확보된 물로서 효과적인 기능수로 개발될 가능성을 가지며, 유효성과 관련된 기전은 더 연구될 필요성이 있다.

• 연구논문집
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• 통권33호
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• pp.99-109
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• 2003

Recently the utilization of the ozone dissolved de-ionized water(DIW-$O_3$) in semiconductor wet cleaning process and photoresist stripping process to replace the conventional sulfuric acid and hydro peroxide mixture(SPM) method has been studied. In this paper, we propose the water-electrode type ozone generator which has the characteristics of the high concentration and purity to produce the high concentration DIW-$O_3$ for the photoresist strip process in the semiconductor fabrication. The proposed ozone generator has the dual dielectric tube structure of silent discharge type and the water is both used to electrode and cooling water. Through this study, we obtained the results of the 10.3 wt% of ozone gas concentration at the oxygen gas of 0.5 [liter/min.] and the DIW-$O_3$ concentration of 79.5 ppm.. Through the photoresist stripping test using the produced DIW-$O_3$, we confirmed that the photoresist coated on the silicon wafer was removed effectively in the 12 minutes.

• 한국동물학회지
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• 제8권2호
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• pp.28-32
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• 1965

It is well known that many kinds of chemical or metalic agent which were ionized or undissociated at toxified external medium and remarkable effect occurred to the fresh water fish. The effects of hydrogen ion concentration on serum protein of fresh water fish, (phycephalus argus CANTOR) had not been reported yet. In this point, authors attempted to study the changes of A/G ratio, total protein, hemoglobin, hematocrit, RBC , liver and kidney weight of snake head in the above environment. 95 snake heads were subjected to external medium with PH-4.5 and A/G ratio, hematocrit, hemoglobin, total protein, RBC, and liver & kidney weight were measured at 32.80, 15202000 and 272 hours respectively. In whole experimental period, L 1 and L2 globulin increased, on the other, albumin decreased as compare with control . Hence, the A/G ratio decreased remarkably . Though, total protein increased prominently through the whole experimental period, hematocrit, hemoglobin, RBC, increased only at 80 hours, and then decreased as compared to the control. Liver weight revealed distinctive increase at 80 hours, but no remarkable change could be seen there after. Hence, kidney weight revealed continuous rise. By these results, it may be said that as snake head were subjected to external medium with PH-4.5, this environmental factor influenced protein metabolism , blood component and organs.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.185-188
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• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP Process, deionized water (DIW) pressure, purified $N_2$ (P$N_2$) gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and P$N_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• 한국환경보건학회지
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• 제39권5호
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• pp.391-407
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• 2013

Micropollutants emerge in surface water through untreated discharge from sewage and wastewater treatment plants (STPs and WWTPs). Most micropollutants resist the conventional systems in place at water treatment plants (WTPs) and survive the production of tap water. In particular, pharmaceuticals and endocrine disruptors (ECDs) are micropollutants frequently detected in drinking water. In this review, we summarized the distribution of micropollutants at WTPs and also scrutinized the effectiveness and mechanisms for their removal at each stage of drinking water production. Micropollutants demonstrated clear concentrations in the final effluents of WTPs. Although chronic exposure to micropollutants in drinking water has unclear adverse effects on humans, peer reviews have argued that continuous accumulation in water environments and inappropriate removal at WTPs has the potential to eventually affect human health. Among the available removal mechanisms for micropollutants at WTPs, coagulation alone is unlikely to eliminate the pollutants, but ionized compounds can be adsorbed to natural particles (e.g. clay and colloidal particles) and metal salts in coagulants. Hydrophobicities of micropollutants are a critical factor in adsorption removal using activated carbon. Disinfection can reduce contaminants through oxidation by disinfectants (e.g. ozone, chlorine and ultraviolet light), but unidentified toxic byproducts may result from such treatments. Overall, the persistence of micropollutants in a treatment system is based on the physico-chemical properties of chemicals and the operating conditions of the processes involved. Therefore, monitoring of WTPs and effective elimination process studies for pharmaceuticals and ECDs are required to control micropollutant contamination of drinking water.

• Journal of Advanced Marine Engineering and Technology
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• 제39권1호
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• pp.75-80
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• 2015

최근 일정기간 해상에서 운용된 해양교통시설물은 수주와 파도 유입구에 해조류 증착이 발생되어, 파력발전 효율이 감소되는 문제점이 발생하였다. 따라서 해조류 증착을 억제하고자 단일채널 AFS(Anti-Fouling System)를 적용하였다. 그러나 단일채널 AFS에 이용된 구리 전극봉의 이온화 불균형 현상이 나타났다. 구리 전극봉의 이온화 불균형은 전극봉의 교환시기를 앞 당겨, 잦은 전극봉의 교체가 필요한 문제가 발생하였다. 본 논문에서는 다 채널 전류제어 방식을 이용한 해양교통시설물용 다채널 AFS의 알고리즘을 만들고, 하드웨어를 설계, 제작하였다. 그리고 기존의 단일채널 AFS와 다채널 AFS의 실 해역실험을 통해 제어방식에 따른 구리 전극봉 이온화 차이를 확인할 수 있는 비교 실험을 진행하였다. 실 해역실험결과 다채널 AFS에 이용된 구리 전극봉이 균일하게 이온화 되는 것을 확인할 수 있었다.

• 대한기계학회논문집B
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• 제23권8호
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• pp.1031-1039
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• 1999

Electrospraying comprises the generation of liquid droplets by applying a high voltage to the surface of a liquid. By monitoring the current and the flow rate it was possible to obtain a stable cone jet mode in a given condition. In this work the liquid contained NaCl particles resolved in distilled water. The NaCl particles increased concentration of the ionized solution and thus increased electrical conductivity of the liquid, which was inversely proportional to the flow rate in the cone jet mode. A number of sprayed droplets were sampled and dried enough, and then the size of NaCl particles were measured. The measured droplet diameter was a little larger than two theoretical diameters, Rayleigh diameter and mobility diameter.