• 대한기계학회논문집B
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• 제35권5호
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• pp.547-550
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• 2011

레이저 기반의 무바늘 액체 약물전달장치는 계속해서 개발되어왔다. 레이저 빔이 고무 챔버 내부의 액체에 모이게 된다. 초점이 맞춰진 레이저 빔은 공기방울을 생성시키고 급격히 팽창하게 된다. 밀봉된 챔버 안쪽에서의 급격한 부피변화는 액체약물을 마이크로 노즐을 통해 빠르게 밀어내어 마이크로 약물젯을 생성한다. 노즐의 출구지름은 100 ${\mu}m$ 이하이며 본 연구팀은 생성된 마이크로 약물젯의 속도가 인체의 연조직으로 침투시키기에 충분함을 확인하였다. 이 실험에서는 사람의 혈전을 모사한 무게 비 5%의 젤라틴 수용액을 냉각시킨 샘플과 돼지 지방층을 사용하여 침투실험을 수행하였다.

• 상하수도학회지
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• 제32권5호
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• pp.381-388
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• 2018

Microbubbles oxygen transfer to water was simulated based on experimental results obtained from the bubbles generation operated under varying liquid supply velocity to the multi-step orifices of the generator. It had been known that liquid supply velocity and bubble size are inversely related. In the oxygen transfer, a non-steady state was assumed and the pseudo stagnation caused the slow movement of bubbles from the bottom to the water surface. Two parameters were considered for the simulation: They represent a factor to correct the pseudo stagnation state and a scale which represented the amount of bubbles in supply versus time. The sum of absolute error determined by fitting regression to the experimental results was comparable to that of the American Society of Civil Engineers (ASCE) model, which is based on concentration differential as the driving force. Hence, considering the bubbles formation factors, the simulation process has the potential to be easily used for applications by introducing two parameters in the assumptions. Compared with the ASCE model, the simulation method reproduced the experimental results well by detailed conditions.

• Nuclear Engineering and Technology
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• 제33권2호
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• pp.145-155
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• 2001

This simulation first allows us to define a transition zone from a bubble to jet mode of the argon out-flow and hereinafter to define a similar area for water-steam leak in the KALIMER SG (Korea Advanced Liquid Metal Reactor Steam Generator) using a water mock-up system, taking into account the KALIMER leak classification and tube bundle design, as a simulation of a real water-steam into sodium leak. in accordance with leak conditions in the KALIMER SG, the transition from bubbling to jetting is studied by means of turbulence regime simulation for argon out-flow through a very small orifice, which has the equivalent diameter of about 0.253 mm. finally the noise generation mechanism is explained from the existing experimental data. We also confirmed the possibility of micro-leak detection from the information of the bubbling mode through simulations and the experiment in this study.

• 한국환경과학회지
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• 제29권11호
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• pp.1025-1032
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• 2020

This work was performed to develop a dip injection wet scrubber (DIWS) system with chlorine dioxide as the oxidant. The exhaust pollutants from a lime kiln of paper-mill were introduced to the system. When NaClO₃ was used to oxidize NO into NO₂, the oxidation was unsatisfactory and the combination of HNO₃ or H₂SO₄ was required for 100% oxidation. ClO₂ is recommended to oxidize NO and SO₂ effectively. With the combination of 1^st stage of DIWS and ClO₂, 57.1% of NOx and 98% of SO₂ were effectively removed. In the case of 2^nd stage of DIWS and ClO₂, 93.5% of NOx and 99% of SO₂ were removed. The ClO₂+DIWS process was superior to the ClO₂+Scrubber process in terms of investment, running cost and NOx removal efficiency.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2010년도 제34회 춘계학술대회논문집
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• pp.326-330
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• 2010

본 연구진은 레이저-물질 간의 상호작용을 응용하여 새로운 방식의 약물 전달 시스템을 개발하고 있다. 레이저 빔이 마이크로 단위 크기의 고무 챔버 속에 채워져 있는 액체 속에 집광되면 순간적인 고에너지 전달로 인해 기포가 생겨나고, 이로 인한 빠른 부피팽창으로 인해 마이크로 노즐 속의 약물 용액이 빠른 속도의 마이크로 젯의 형태로 분사되는 원리를 이용하는 것이다. 실험에서 노즐 출구의 지름은 125 ${\mu}m$, 측정된 마이크로 젯의 속도는 265 m/s였다. 이 장치의 주요한 특징은 시간에 따른 마이크로 젯의 제어가 가능하다는 것이다.

• 상하수도학회지
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• 제26권1호
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• pp.107-113
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• 2012

Pollutants in aquaculture system effluent mostly originated from solid wastes including uneaten feed and excreta of cultured species. In this research, DAF(Dissolved Air Flotation) unit is suggested as an integrated solid control unit especially as a form of IIBG(Inline Injection Bubble Generation) process in aquaculture system. Solid removal performance of DAF unit was examined under various operation and salinity conditions with turbidity and suspended solid. Solid waste removal efficiencies were found to be affected by operation conditions including saturator pressure, recycle ratio, coagulant concentration. Solid removal efficiency was higher under higher saturator pressure and recycle ratio under which condition larger number of bubbles is generated. Coagulant is thought to have important role in creating bubble-particle aggregate by showing better removal efficiency with higher concentration. However higher saline water showed less effectiveness in removing solids by DAF(IIBG). Application of DAF(IIBG) process also showed additional effect in phosphate removal and DO(Dissolved Oxygen) supply. Phosphate existed in polluted water was removed up to 46% after treatment, which is thought to attribute to aluminium phosphate precipitation. And DO concentration was found to increase over 50% of initial saturation concentration after the injection of micro-bubbles. Through experiments on solid removal from aquaculture effluent, DAF(IIBG) process is estimated to be effective solid control method. This property can help aquaculture system being installed and operated simply and effectively.

• 산경연구논집
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• 제9권12호
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• pp.23-29
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• 2018

Purpose - The purpose of this study is to apply a cost effective ultrasonic odor reduction method that generated micro-bubbles using ejector to the Southeast Asian wastewater market. Research design, data, and methodology - A leather maker located in Ansan-city, Gyunggi-do, South Korea was sampled from the collection tank to select experimental materials. Experimental setup consisted of circulating water tank-air ejector-ultrasonic device, and circulating wastewater. Sample analysis was performed by CODcr, T-N, T-P, and turbidity by the National Environmental Science Institute. Results - Experimental results show that it is most effective in removing odors when the frequency range of ultrasonic wave is 60~80 Khz and the output is 200 W. It showed that the concentration of complex odor dropped from a maximum of 14,422 times to a minimum of 120 times. Also, analysis of ammonia and hydrogen sulfide in specific odor substances has shown that they were reduced from 1.5 ppm to 0.4 ppm and from 0.6 ppm to 0.1 ppm, respectively. Conclusions - It is possible to shorten more than 12 hours in the treatment of micro-organisms. It can be seen that the processing time of odor after ultrasonic treatment in the pre-treatment facility is reduced by 25% when compared to the resultant micro-organisms after the chemical treatment, that is, the time of the bio-treatment of micro-organisms. Based on the results, it was confirmed that the pre-treatment method using the ultrasonic and the air ejector device of the experiment shows the effect of reducing the water pollutants and odor more effectively in a relatively short time than the conventional advanced oxidation method.

• 한국환경과학회지
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• 제20권3호
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• pp.291-299
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• 2011

The main objectives of this research are to investigate characteristics of ozone solubility due to low solubility of conventional bubbles-ozone generators, evaluate the treatment characteristics of reclaiming textile wastewater for industrial water by means of micro/nano bubbles-dissolved ozone flotation(MNB-DOF) process. The textile wastewater used in this research was obtained from final effluent of the textile wastewater in B city. There is a 400L reactor which consists of a micro-nano bubble system and a ozone generator for experiments. As a result of generating micro-nano bubbles (below $0.5{\mu}m$) by using of MNB-DOF process, it improved ozone solubility due to higher ozone transfer rates. Consequently, the shorter ozonation time clearly indicates the lower power costs. The reported results clearly indicated that MNB-DOF process can be effectively and inexpensively. Results of the experiments through MNB-DOF process in this study satisfy all reclaiming standards as industrial water: pH 6.5~8.5, SS 10 mg/L or below, $BOD_5$) 6 mg/L or below, turbidity 10 NTU or below, Coliforms 1,000/100 mL or below. Therefore there is a possibility of the reclaiming of the textile wastewater as industrial water.

• 공업화학
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• 제33권6호
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• pp.606-612
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• 2022

수용액에서 수용성 염료를 소수성 염료로 전환시킨 후 마이크로 버블을 이용한 침전 및 부상응집에 의한 염료를 제거하는 연구를 수행하였다. 양이온성 염료에 음이온 collector를 반응시키며, 또한 음이온성 염료에 양이온 collector를 첨가하여 소수성으로 변환시켰다. 소수성으로 전환된 염료 용액을 회분식 반응기에 저장하여 마이크로 버블을 분사시켜 색을 제거하였다. 염료 용액을 제조하기 위해 Basic Yellow 1 및 Direct Orange 10을 사용하였으며, sodium dodecyl sulfate, oleic acid sodium salt 및 amine류와 같은 음이온 및 양이온 collector를 사용하면 색 제거에 효과적이었으며, 모든 색은 8분 이내에 제거되었다. 색 제거는 collector의 첨가량과 수용액 pH의 영향을 받으며, 염료농도에 비해 극히 소량의 계면활성제를 첨가하였을 경우에는 pH에 의존하였으나, 염료농도와 비슷한 collector 양을 첨가하였을 경우에는 pH에 의존하지 않았음을 알 수 있었다. 그 이유는 collector와 염료가 1:1M로 반응하여 소수성이 완전히 부여되어야 제거됨을 알 수 있었다.

• 대한환경공학회지
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• 제38권9호
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• pp.513-520
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• 2016

수중에 용존된 가스뿐 아니라 소독부산물과 같은 휘발성 화합물은 탈기에 의해 효과적으로 제거할 수 있는 것으로 알려져 있다. 탈기공정에 사용되는 미세 기포는 수백~수천 ${\mu}m$이지만 부상 공정의 기포는 수 ${\mu}m$ 정도로 작다. 이에 따라 부상공정에서의 마이크로 기포는 수중의 휘발성 화합물이 대기로 방출될 수 있는 매우 넓은 기-액 비표면적을 제공한다. 또는 마이크로 기포는 상승 속도가 느려서 휘발성 화합물이 방출될 수 있는 긴 체류시간을 갖게 된다. 본 연구에서 일련의 탈기와 부상 실험을 실시한 결과, THMs의 제거율에서 상당히 큰 차이가 있었다. THMs의 물질전달계수 $K_La$ 역시 큰 차이를 보였다. 따라서 부상공정에서 THMs과 같은 휘발성 화합물을 제거하기 위해서는 일반적으로 입자제거를 위하여 적용되는 통상적인 운전범위보다 더 높은 기포체적농도가 필요함을 알 수 있다.