• Journal of Digital Convergence
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• v.18 no.11
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• pp.329-336
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• 2020

The study investigated the perception and experience of infection control targeting dental users. During July-August 2020, 198 adults over the age of 20 were surveyed on general characteristics, infection control awareness and experience, and improvement. Analysis was performed using PASW Statistics ver 18.0. The research results, 91% of dental users recognized that infection control was important. In the recognition of infection control were highly investigated oral treatment equipment sterilization, hand hygiene and glove replacement before and after treatment by dental staff. And dental users was relatively low the replacement of disposable gowns and safety glasses for each patient by medical staff. The dental staff are doing well in personal protection and instrument sterilization. Surface disinfection and water quality management needed improvement. It was meaningful to suggest improvement in infection control based on the perception and experience from the perspective of dental users. It is expected to be used as basic data necessary for high-quality medical services through infection control in dental medical institutions.

• Korean Chemical Engineering Research
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• v.50 no.1
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• pp.83-87
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• 2012

Activated carbon fiber (ACF) was used to remove four kinds of trihalomethanes(THMs) from tap water which were remained as by-products during the chlorination of water. Adsorption capacity was investigated as a function of THMs concentration and solution temperature, and adsorption mechanism was studied in relating to the surface characteristics of ACF. All the four kinds of THMs were rapidly adsorbed on the surface of ACF by physical adsorption due to the enormous surface micropores and chemical adsorption due to the hydrogen bonds, showing a Langmuir type adsorption isotherm. Langmuir type is especially profitable for the adsorption of low level adsorptives. ACF was very effective for the removal of THMs from tap water because the THMs concentration is below $30{\mu}g/L$ in tap water. The adsorption amount of THMs on ACF increased in order of the number of brom atom; chloroform, bromodichloromethane, dibromochloromethane, and bromoform. The adsorption capacity increased as increasing the number of brom atom due to the decrease of polarity in solution. The adsorption capacity of THMs on ACF can be enhanced by proper surface treatment of ACF.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
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• v.19 no.1
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• pp.11-15
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• 2013

In order to find a sanitary logistic way to handle library books, papers and environmental sources contacting the books were tested in their microbial contamination load and methods to decontaminate the books were investigated. Generally bacterial load of inner book pages was very low, but increased when contaminated with liquid such as saliva. In contrast, their lateral ends showed much higher bacterial contamination presumably due to dry dust contamination on there. As operations to improve the sanitary book conditions, turbulent air blow was found to be workable for reducing dry dusty contamination and 280 nm ultra-violet (UV) light emitting diode (LED) was so for decontaminating wet surface contamination. Microbial inactivation by the UV LED could be realized with irradiation for more than 5 minutes at 2 cm distance. Air blow of 5.5 m/s for 0.5~1 minute could reduce the dusty contamination on a model book surface.

• Research in Plant Disease
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• v.28 no.1
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• pp.54-56
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• 2022

A peanut plant showing wilt and browned symptom was found in the field of Gochang, Korea, in July 2021. The symptomatic peanut plant was collected from the field and isolation of the pathogen caused the wilt symptom was performed using the collected sample on TZC media. The dominated colony on media was isolated colony on media was isolated and subcultured of purification. The pure cultured bacteria was identified as Ralstonia solanacearum by sequencing of 16S rRNA gene. Multiplex polymerase chain reaction using phylotype-specific primer set identified isolate as phylotype I (R. pseudosolanacearum). Phylogenetic tree was constructed based on 16S rRNA sequence and it was closed with R. pseudosolanacearum. Pathogenicity of the isolates was assessed by soil drenching inoculation on 4-week-old peanut plant. The wilt symptom was successfully reproduced by inoculation of the isolates after 14 days. This is first report of bacterial wilt caused by R. pseudosolanacearum on peanut in Korea.

• Korean Journal of Poultry Science
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• v.20 no.1
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• pp.33-41
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• 1993

Among the several factors that affect shelf-life of washed shell eggs, storage temperature and relative humidity were the most important. Besides those factors listed above, temperature of washing water, composition of foreign substances and washing method of eggs were also the factors affecting the shelf-life of the eggs. The effect of sanitizer treatment was significant in extending the shelf-life of eggs compared with washed and unwashed eggs. In case of oil coating treatment, the shell eggs treated showed the better results than that of washed and unwashed eggs because the coating materials prevented the moisture evaporation from the inner shell eggs and kept the contamination of microorganisms from the environment. Consequently, it is considered that reducing egg shell contamination of microorganisms and proper treatment could be the key to extend the shelf-life of shell eggs.

• Restorative Dentistry and Endodontics
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• v.19 no.1
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• pp.106-113
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• 1994

Dental professions are considered high risk for contracting hepatitis infection. In Korea, many patients are hepatitis B virus carriers. HBV are most efficiently transmitted by blood. Root canal treatment, as in cases of acute pulpitis always accompanied by contaminated blood. Therefore it is absolutely necessary to use irrigation solutions having strong antiviral effect for prophylaxis both dental personnel and patients. The purpose of this study was to investigate the antiviral effect of seven root canal irrigation solutions by radioimmunometric test. The solutions were 5% sodium phyochlorite, 5% cresol, 2% glutaraldehyde, 3% hydrogen peroxide, 0.05% chlorohexidine, 10% iodine, and 70% isoprophyl alcohol. Each irrigation solutions was mixed with serum preparated from HBsAg positive patients and sera were diluted to 1:1. 1:4. 1:20 and 1:100. Percentage of radioactivity was assayed with AUK(Sorbin biomedica, Italy) and COBRA(Packwood Instrument company, USA). Sodium hypochlorite and glutaraldehyde showed most strong antivral activity against HBsAg. Isoprophyl alcohol had moderate antiviral effect and the effect and the effect was increased especially in 1:4 solution. Hydrogen peroxide exihibited very weak aintivral activity. Cresol, chlorohexidine, and iodine exhibited little antiviral activity.

• Korean journal of food and cookery science
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• v.25 no.3
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• pp.365-378
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• 2009

This study performed microbiological hazards analysis in raw food materials, cooking processes, kitchen staff, utensils, and the environment in order to obtain contamination levels of S. aureus in school foodservice operations. S. aureus was not detected in cooked foods offered by the foodservice operations; however, it was found in raw food materials prior to cooking. In the case of vegetables, S. aureus was detected in washed mung bean sprouts, parboiled mung bean sprouts, and bellflower roots both before and after disinfection, at levels of 2.2, 1.0, 1.0, and 1.0 log CFU/g, respectively. For processed foods, S. aureus was detected in one sample of packaged bean curd as well as in mung bean jelly cake at the level of 1.5 log CFU/g. For meat products, S. aureus was detected in beef brisket and chicken at levels of 2.3 and 1.3 log CFU/g, respectively. To determine microbiological hazard data for the hands and gloves of cooking personnel, the staff members were divided into two groups: a group presenting Enterobacteriaceae or coliforms, and another group presenting neither Enterobacteriaceae nor coliforms. The results showed that S. aureus was detected on the hands of staff in each group at levels of 2.0 and 2.1 log CFU/hand, respectively, and at 1.8 and 0.0 log CFU/hand on the gloves of staff in each group, respectively. Among kitchen utensils, as an environmental factor in school foodservice operations, S. aureus was detected on meat knives, mixing bowls, and dish cloths at levels exceeding 1.0 log CFU/hand.

• Korean journal of applied entomology
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• v.20 no.2 s.47
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• pp.103-106
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• 1981

This experiment was carried out to investigate the vertical penetration and diffusion of fumigants for soybean disinfection in jumbo silo. The results were as follows, 1. Using the methylbromide independently as a soybean fumigant, penetration and diffusing velocity of methylbromide gas which moved from the top to the bottom through the vertica1 silo was too rapidly, it was possible to find out more 60mg/l of methylbromide gas concentration at bottom of silo within 4 hours after beginning the fumigation. And it showed the tendency of reducing methylbromide gas concentration gradually over the 10 hours from tile beginning the fumigation. 2. In case of added $CO_2$ gas to the methylbromide as a carrier is much more rapid velocity of penetration and diffusion of methylbromide gas than that of methylbromide gas independently. Therefore methylbromide gas concentration at bottom of silo was detected over the 70mg/l within 1.5 hours after beginning the fumigation.. 3. On the other hand, hence the phostoxin as a soybean fumigant was less velocity of Penetration and diffusion of the gas through the vertical silo compare to methylbromide gas, the phostoxin gas concentration couldn't detect over the 10mg/1 during the whole fumigation period at the bottomside of silo. 4. Test insects (rice weevil; sitophilus oryzae. L.) inserted at bottom of silo for examine the fumigation effect were killed completly by using the methylbromide independently and added $CO_2$ gas to methylbromide, while using the phostoxin the test insects were most alive.

• Journal of Korean Society of Environmental Engineers
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• v.22 no.4
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• pp.661-669
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• 2000

This research was carried out to evaluate effect of metallic release and change of water corrosive indices by the pH and alkalinity adjustment using the SDLS (Simulated Distribution Loop System) which consist of six types of pipe loop with DCIP, PVC, PE, STS304, CP, GSP, respectively, and its effects on water quality changes which were microbes quality(SPC), residual chlorine. THMs and other parameters. And it was to propose optimal criteria of water quality control for the field application. According to the results, water control system by pH and alkalinity adjustment showed the changing of corrosive water and reducing of metallic release rate and it was not affects of THMs formation, microbes regrowth and variation of other parameters. Water quality stability and corrosion control were due to calcium carbonate precipitation film formation of pipe inner by water quality control. Therefore, corrosive water control system by pH and alkalinity adjustment can be attributed to effective water quality management in water distribution system according to water quality stability of pH and TIC(Total Inorganic Carbonate concentration) that affect the precipitation and dissolution of solids.

• Restorative Dentistry and Endodontics
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• v.26 no.4
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• pp.350-359
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• 2001

목적 - 근관형성시 근관내 상아질벽에는 항상 도말층(smear layer)이 형성되는데, 이는 상아질, 치수조직 잔사, 조상아세포 돌기, 때로는 미생물 등으로 구성되며, 주사전자현미경상으로는 비규칙적이며, 무정형의 구상(granular)구조물로 관찰된다. 본 연구에서는 도말층의 유무에 따른 혐기성 미생물, Prevotella nigrescens의 근관내 상아질 부착정도를 주사전자현미경으로 평가하고자 한다. 지금까지 사용되었던 실험방법에 비하여 보다 임상적 환경에 가까운 실험방법을 고안, 신빙성 있는 연구결과를 기대할 수 있도록 하였다. 방법 - 치주질환이나 외상 등의 원인으로 발거된 상, 하악 전치 18개를 사용하였다. 각 치아의 치관부를 백악법랑경계부위에서 절단하고, 1군(5개치아)은 10ml의 생리식 염수를, 2군(5개치아)과 3군(5개치아)은 10ml의 3.5% NaOCl을 근관관주용액으로 사용하여 근관형성을 하였다. 근관형성 완료후 1군과 2군은 10ml의 생리식염수로, 3군은 10ml의 0.5M EDTA용액으로 final flush를 시행하여, 3군의 도말층을 제거하였다. 치근수직절단과 ethylene oxide(EO) gas 소독후 1, 2, 3군의 시편(각군10개시편)을 Prevotella nigrescens가 부유된 Brain Heart Infusion with Yeast estract, Hemin and Menadione(BHIYHM) broth내에 37$^{\circ}C$에서 3시간 동안 incubation했다. 4, 5, 6군은 실험과정을 검증하기 위한 대조군으로써, 4군(1개치아)과 5군(1개치아)은 1군, 2군과 같이 각각 생리식염수와 NaOCl만을 이용한 근관형성으로 도말층을 잔존시키고, 6군(1개치아)은 3군과 같이 NaOCl과 EDTA를 적용하여 도말층을 제거한 후, 치근 수직절단과 EO gas 소독을 시행했다. 모든 시편(1, 2, 3, 4, 5, 6군)을 통상의 방법에 따라 처리한 후 주사전자현미경을 통하여 관찰, 근관내면에 부착되어 있는 Prevotella nigrescens의 개수, 모양, 상아세관 및 도말층과의 관계 등을 관찰, 비교, 분석하였다. 결과는 t-test와 one-way ANOVA를 통하여 통계처리 하였다. 결론 - 1. 근관형성 후 근관내 상아질 표면 전체는 도말층으로 덮여 있는 양상을 보였다. 2. 3.5% NaOCl과 0.5M EDTA를 적용하여 근관내 도말층을 효과적으로 제거할 수 있었으며, 상아세관 개구부가 확연히 노출되어 있는 소견을 관찰할 수 있었다. 3. 도말층이 덮인군에서 미생물의 부착이 유의성 있게 높았다(P<0.05). 4. 근관 형성중 형성되어 근관 상아질을 덮고 있는 도말층이 미생물의 부착을 증가시켜, 근관 재감염의 기회를 증가시킴을 알 수 있었다.