• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.18 no.11
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• pp.933-940
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• 2006

In this study multi-zone modeling program CONTAM 2.4 developed by NIST is used for estimating the air disinfection rate of the interior of a room which is set up the indoor air disinfection system with filter and ultra violet germicidal irradiation (UVGI). Developed models those enable to predict the transmission of air home contagion such as bacteria and fungus generated in our daily life are useful model for designning air cleaning & ventilation system of building. Also, results indicate that these models are enable to compute the real situation that is almost impossible of carrying out experiment in an actual condition due to biohazard problems and suggest that engineers will use these models as a design tool for the future immune building system.

• Membrane Journal
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• v.24 no.2
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• pp.88-99
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• 2014

Demand for water is increasing due to rapid population growth and increased industrial activities. Membrane technologies have attracted most attention as a promising advanced technology for the supply of sustainable water resources. Chemical and structural properties of polyamide membranes, one of the most widely used membranes in water treatment plant, has been reported to be affected by residual chlorine dissolved in water after chlorine disinfection. This paper focuses on the chlorine speciation at various solution pHs and change of surface properties/performance of polyamide membranes due to the chlorine exposure.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.6
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• pp.199-206
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• 2016

The aim of this study was to establish the optimal conditions to design a shoe rack that could effectively sterilize and deodorize shoes contaminated by various bacteria. The manufacture and evaluation of a shoe rock was conducted for one year from October 2014 to September 2015. The antibacterial efficacies were evaluated using Escherichia coli and Staphylococcus aureus by JIS Z 2801:2010. The deodorization efficiency was identified by the standard method for deodorization efficiency evaluation of an indoor air cleaner established by Korea Air Cleaning Association, SPS-KACA002-132:2006. The results showed that antibacterial evaluation showed more than 99.9% of the sterilization effects on Escherichia coli and Staphylococcus aureus after exposure to ultraviolet (UV) light for 30 seconds. The average deodorization efficiency for the test gases was 42.5%. The temperature in the shoes and in the shoe rack was lower than $40^{\circ}C$ and $25^{\circ}C$, respectively, when the UV lamp was turned on for 5 minutes and off for 25 minutes repeatedly. This was controlled by turning the UV lamp on and off to maintain the appropriate temperature in the shoes. In conclusion, the real deodorization efficiency is expected to be higher than the measured value because the internal volume of the shoe rack was smaller than the test chamber used to measure the deodorization efficiency. The deodorization effect could be increased further by the sterilization of bacteria causing bad odors in shoes. Further studies will be needed to determine the temperature deviations within the shoe rack to provide constant conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.6
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• pp.558-566
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• 2017

In this study, we developed an electron-emission OH radical generator for waste water treatment. The stability of the circuitry was ensured by implementing stable pulse waves with a MOSFET and reducing the momentary current rise. The OH radical generator uses a high-voltage and low-current discharger. The performance of the device was evaluated experimentally, which showed that it is possible to produce a stable and uniform pulse waveform for the drain current of the power MOSFET, which is connected to the input side of an AC multiplying converter through negative feedback circuitry with CR-snubber architecture. It was also possible to reduce the excitation current of the converter and improve the stability of the oscillation circuit. In addition, the generator can generate hydroxyl radicals stably. The bactericidal activities were also evaluated, and the germicidal power for E. coli, S. aureus, and S. flexneriwas improved by 99.9% or more after 60 minutes.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.199-199
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• 2019

친환경적인 산업기술인 초미세기포(Ultra Fine Bubble, 이하 UFB) 제조 기술은 농업, 수처리, 그리고 환경재생 등 다양한 분야에서 적용되고 있다. UFB는 1,000nm 이하의 크기를 가진 기포로서 용존산소를 통한 농작물 성장 촉진 및 수중의 대장균 및 세균제거 등 다양한 성질을 지니고 있다. 본 연구는 기존의 방식과는 다르게 자왜현상을 메카니즘으로 갖는 타격식으로 제조된 UFB 생성장치를 통해 생성된 200nm이하의 크기를 가진 UFB를 실제 딸기 농장에 적용하여 딸기의 성장을 모니터링하고 살균 성능을 가진 화학제품과 UFB를 대장균에 적용하여 대장균 제거효율을 비교하였다. 딸기농장에 기존에 사용되던 지하수 대신 UFB를 주입하여 딸기성장 초기단계의 DO농도를 측정하고 딸기 생식단계에 산소포화도에 대한 질산염의 농도를 측정하여 상관관계를 분석하였으며 각각의 딸기 열매를 수확하여 무게를 비교하였다. 또한 대장균이 함유되어있는 대변을 채취하여 살균 성능을 가진 화학제품과 UFB수를 각각 대장균이 포함된 실험원수와 반응시켜 배양하고 검출된 대장균 개체 수에 확인하여 제거효율을 비교분석 하였다. 딸기성장 초기단계의 DO농도 측정결과 DO농도가 6~9ml/L로 높게 유지되고 있음을 확인하였고 딸기 생식단계에서 산소포화도가 일정하게 유지되고 있음에 따라 질산염의 농도가 점차 감소하는 것을 확인하였다. 또한 수확한 열매의 무게는 각각 37g, 19g으로 UFB수를 통해 재배된 딸기가 약 2배 이상 높은 것으로 나타났다. 이와 같은 결과는 수중의 용존산소가 딸기 성장 초기에 뿌리의 발육에 긍정적인 영향을 미치고 질산염을 원활하게 섭취하게 하여 딸기의 성장이 촉진되었고 열매의 무게가 증가하였다고 판단된다. 또한 대장균이 함유된 원수, 원수+화학제품, 원수+UFB를 접종하여 대장균과 반응시켜 배양하여 대장균 개체 수를 확인한 결과, 원수의 경우 약 600개의 대장균의 개체수가 나타났고, 원수+화학제품의 경우 검출된 대장균의 개체 수는 약 300개 정도로 나타났다. 이를 희석한 비율을 계산하여 대장균 개체 수를 나타내면 원수 약 6000개/ml, 원수+화학제품 약 6000개/ml로 비슷하게 나타난다. 반면, 원수+UFB 경우 검출된 대장균의 개체 수는 1개로 희석한 비율을 계산하여 대장균 개체 수를 나타내면 약 20개/ml로 나타난다. 이와 같은 결과를 통해 UFB는 99.9%의 대장균 제거효율을 보였으며, 화학제품은 대장균 제거효율을 보이지 않았다. 따라서 화학제품은 항균기능은 작용하지만 살균기능은 거의 없다고 판단하였고, UFB의 경우 기포가 소멸하면서 발생되는 초고온, 초고압을 형성하여 주변에 존재하는 대장균을 제거하였거나, 기포가 소멸할 때 발생되는 OH 라디칼을 통해 대장균의 세포를 화학적으로 분해시켜 대장균을 제거하였다고 보인다.

• Applied Chemistry for Engineering
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• v.33 no.4
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• pp.444-450
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• 2022

The effect of coated polyester (PET) textiles with metal oxide, chitosan, and copper ion on the antibacterial and antiviral activities was evaluated to investigate the applicability of multi-coated PET textiles as antiviral materials. Compared to coated PETs with a single agent, multi-coated PETs reduced the loading amount of coating materials as well as the contact time with bacteria for a bacterial cell number of < 10 CFU/mL, which was not detectable with the naked eyes. Metal oxides generate reactive oxygen species (ROS) such as free radicals by a catalytic reaction, and copper ions can promote contact killing by the generation of ROS. Chitosan not only enhanced antibacterial activities due to amine groups, but enabled it to be a template to load copper ions. We observed that multi-coated PET textiles have both antibacterial activities for E. coli and S. aureus and antiviral efficiency of more than 99.9% for influenza A (H1N1) and SARS-CoV-2. The multi-coated PET textiles could also be prepared via a roll-to-roll coating process, which showed high antiviral efficacy, demonstrating its potential use in air filtration and antiviral products such as masks and personal protective equipment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.10
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• pp.437-443
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• 2018

This study investigates the effect of the mixing elements on the pressure loss and mixing performance in line mixer. The high density ozone water devices mixed with gas and liquid are used in various fields such as sterilizing of group feeding facilities and water quality management at a fish farm. Due to the decrease in rainfall due to climate change, pasteurization of drinking water from ground water and surface water is extremely important. Therefore, it is intended to develop a line-mixed gas liquid mixer with a small amount of space. In this study, the effects of the number of static mixers and the types and the number of the orifice used in line mixer on the volume fraction and the pressure loss were studied by CFD simulation. The pressure drops of line mixer with orifice which curved vanes were attached to were down to more than 50 percent of that of line mixer with static mixer whereas the mixing performance of the former was similar to that of the latter.

• Journal of Food Hygiene and Safety
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• v.23 no.2
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• pp.98-107
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• 2008

The ozone has the oxidizing power which is powerful the fluorine and the antimicrobial spectrum of wide scope. Researches were carried out to use the merits that ozone has in various fields including the food industry, and many studies are also conducted nowadays for more efficient use of ozone. The ozone was permitted legally as a food additive and was practically used in the United States, Australia, Japanese etc. In November 2007, ozone water was permitted as a food additive in Korea and the interest in the use of ozone water has been on the rise in the Korea's food industry. As a olisinfectant method, ozone has many advantages. The maintenance and management expenses of ozone are lower than the installation cost at early stages and no by-products are generated after use it compared to others. Recently the demand of ozone as a olisinfectant method is increasing drastically. Although ozone water is popularly used to sterilize raw foods like fruits, vegetables and meats, the cases are still limited and were verified by the survey results. However, the use of ozone water is gradually being increased and is focused on food services. Ozone water refers to a state where ozone is dissolved into water to more conveniently use ozone. Accordingly, ozone water should be managed in regards with the amount and time of water-dissolved ozone, and the control of discharged ozone concentration is required for safe use of ozone water. The items to control mentioned above are directly related to the performance of the devices, and therefore, it is required to newly establish the performance criteria of ozone water manufacturing devices.

• Journal of Korea Society of Industrial Information Systems
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• v.23 no.3
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• pp.25-34
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• 2018

This paper presents a heating source of carbon nanofibers for the efficiency and the drying performance of laundry dryer, and focuses on the applicability-evaluation of its source. To design the proposed heating module, experiments were conducted in terms of surface temperature and surface temperature distribution characteristics of carbon nanofiber lamps. The surface temperature of the lamps increased linearly with increment of a current to flow a lamp and revealing the increasing pattern as the length of the ramps is shorter. The proposed heating source was evaluated based on drying efficiency, moisture evaporation rate at laundry, and internal temperature of a drum during drying process. The drying efficiency satisfied a 45% which is specified in KS C 9319. The moisture evaporation rate and the internal temperature of the drum were respectively 98.88% and $61.1^{\circ}C$, which are similar to that of S's company dryer. From the evaluation and actual drying test results, the proposed carbon nanofiber lamp heating module is considered to be applicable as a heat source for laundry dryer in terms of drying efficiency and drying performance. it is possible to obtain a heat source at a high temperature, an excellent calorific value, an improvement in drying performance, and an effect of sterilizing laundry due to the emission of far-infrared rays. In addition to the applicability, the difference of the drying efficiency between the dryers was analyzed in detail based on the power consumption of the heat sources.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2011.03a
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• pp.99-99
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• 2011

최근 건강에 대한 관심이 높아지면서 천연 기능물질을 이용한 고기능 및 고부가가치 상품개발이 여러 산업분야에서 일반화되는 추세이다. 대표적으로 마이크로캡슐은 원하는 기능을 발휘할 수 있는 기능성 물질을 다양한 방법으로 다양한 제품에 부여함으로써, 기능성 물질을 오랜 기간 동안 외부로 방출하거나 외부의 환경으로부터 보호하는 수단으로 각광받고 있다. 이러한 마이크로캡슐은 의약분야 제초제, 멸충제, 곰팡이 방지제, 살균제로 적용되는 농약분야, 식품 분야, 화장품 분야 등의 전반에 걸쳐 응용 및 연구가 활발히 이루어지고 있다. 이에 본 연구에서는 다양한 나노 합성기술과 유/무기 하이브리드를 이용해 서방화 관련 기술을 개발하여 보습성, 항균, 노화방지, 외부 유해물질로부터의 피부보호 특성을 가진 인체 친화형 복합기능성 섬유 가공조제를 개발하여 다양한 섬유소재에 적용하고자 하며, 궁극적으로 기존 선진국 제품의 기능을 뛰어넘는 원천기술, 즉 새로운 가공제 합성과 응용성, 그 성능평가와 동시에 최적의 처리기술을 개발함으로써 섬유제품의 부가가치를 높이는 계기를 마련하고자 한다. 본 연구에서는 나노미터 직경을 갖는 침상형의 주형(hydroxyapatite)을 이용하여 중공 나노구조체를 제조 한 후 이에 천연고분자를 혼합하여 초음파처리 후 유/무기 하이브리드 기술을 이용한 서방성 가공제를 합성하였다. 중공의 나노구조체 확인은 투과전자현미경(TEM)을 이용하였으며, 주형의 나노구조체는 주사전자현미경(FE-SEM)으로 확인하였다. 이상의 결과를 통해 본 연구에서 제안한 방법이 나노구조체의 새로운 합성방법으로써 가능성을 확인할 수 있었다.