• 한국환경보건학회지
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• 제8권2호
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• pp.33-46
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• 1982

This experiment was carried out for the purpose of reducing alkaloid in reconstituted tobacco sheet and effluent of reconstituted tobacco sheet manufacturing company by treating oxidizing agents such as ozone, sodium hypochlorite, perchloric acid and hydrogen peroxide to tobacco extract created from the manufacturing process of reconstituted tobacco sheet. The effect of alkaloid reduction in tobacco extract by the volume added, time of treatment and pH of oxidizing agents were as follows: 1. When the solid rate of tobacco extract stood at 10 percent, the content of alkaloid, total sugar, total nitrogen and chlorine was 1,600mg/l, 11,000mg/l, 3,200mg/l and 4,000mg/l, respectively. 2. The effect of alkaloid reduction through ozone treatment was in proportion to time of ozone treatment. Alkaloid showed a 31.2 percent reduction under 8 hours' ozone treatment and 0.23g ozone consumed to remove lmg alkaloid. 3. Alkaloid reduction through sodium hypochlorite treatment was influenced by quantity of chlorine in sodium hypochlorite solution. To remove lmg alkaloid, 36.3mg chlorine was used. Reduction of alkaloid was not affected by time of sodium hypochlorite treatment, while showed the best reaction under pH 5-7. 4. The effect of alkaloid reduction by perchloric acid was under the control of the volume added and time of treatment of perchloric acid. The volume of perchloric acid required to remove alkaloid was on the decrease as time of treatment was getting longer. lmg alkaloid was removed by 0.15g perchloric acid under 8 hours' perchloric acid treatment. 5. Alkaloid reduction reacted slowly to the volume added and time of treatment of hydrogen peroxide. Under 8 hours' hydrogen peroxide treatment, it showed maximum removal, registering 10 percent alkaloid reduction.

• 한국산학기술학회논문지
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• 제19권6호
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• pp.154-159
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• 2018

도시가스 회사는 설비의 유지보수 및 점검을 수행할 경우에 가스를 방산하는 경우가 있는데, 가스누출 오인으로 신고 및 주민불안이 발생하게 됨에 따라 활성물질을 통한 천연가스의 부취냄새를 효과적으로 탈취하는 방법을 연구하는데 그 목적을 두었다. 본 연구에서는 천연가스 부취냄새 탈취를 위해 활성물질인 차아염소산나트륨을 이용한 산화법을 통해 천연가스 부취제와 활성물질간 효율적 혼합방법을 위해 간이 탈취방산장치를 제작하여 현장에서 실험을 통해 부취농도를 확인하였다. 탈취실험장치의 기본원리는 방산되는 가스(0.8~1.0MPa)의 에너지를 이용하여 활성물질용액이 첨가되도록 하여 가스 내 부취제와 혼합과정을 거친 후 방출구를 통해 대기로 방산된다. 도시가스 부취제의 활성물질인 차아염소산나트륨을 이용하여 산화반응을 통해 벤츄리와 혼합용기의 직렬연결방식을 적용하여 제작한 장치를 통해 현장에서 효과적으로 부취냄새를 제거할 수 있었다. 하지만, 실질적인 효과를 거두기 위해서는 도시가스의 다량과 고압에서 방산되는 조건에서의 적용하는 문제해결 과제가 남아 있다.

• 구강회복응용과학지
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• 제28권2호
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• pp.139-145
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• 2012

본 연구의 목적은 근관세척제로 2.5% Sodium Hypochlorite, 2% chlorhexidine gel, 식염수를 사용하였을 때, Root ZX와 Sybron Mini의 근관장 측정의 정확도를 평가하고자 하는 것이다. 20개의 발치된 사람 치아에서 Donnelly의 gelatin technique으로 측정하였다. Digital caliper를 이용해 0.01 mm 단위까지 각 전자 근관장 측정기의 0.5와 0.0 level에서 전자 근관장을 측정하였다. 각 측정은 세척제 종류에 따라 세 번식 반복해서 측정하였다. 세 가지 세척제에서 Sybron Mini와 Root ZX의 정확도는 유의한 차이가 없었으며, 제조사의 지시 (Sybron Mini의 0.0 level과 Root ZX의 0.5 level)에서 전자 근관장 측정)에 따라 사용되었을 때 세척제에 따른 전자 근관장 측정기의 정확도는 유의한 차이가 없었다. Root ZX와 Sybron Mini의 사용 시 제조사의 지시대로 사용한다면, 근관세척제으로서 2.5% Sodium Hypochlorite, 2% chlorhexidine gel, 식염수의 사용은 근관장 측정의 정확도에 영향을 미치지 않는다.

• The Journal of Advanced Prosthodontics
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• 제11권3호
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• pp.155-161
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• 2019

PURPOSE. Although dental impression disinfection is determinant to reduce the cross-infection risk, some studies have shown that, in real practice, the disinfection procedures vary considerably. Thus, the aim of this study was to evaluate the antimicrobial effectiveness and the impact on the dimensional stability of addition silicone' impressions of water wash and the most clinically used disinfection solutions: 3% hydrogen peroxide, commercial disinfectant MD520 (Durr) and 1% and 5.25% sodium hypochlorite. MATERIALS AND METHODS. For this investigation, dental impressions were taken on 16 volunteer dental students. The antimicrobial effectiveness of each procedure was evaluated by pour plate method. The dimensional stability was evaluated using a standardized stainless-steel model, according to ANSI/ADA nº19 specification. RESULTS. The study results showed that water wash does not alter the dimensional stability of addition silicone impressions but doesn't reduce the microbial load of the material (P>.05). On the other hand, addition silicone disinfection by immersion with 3% hydrogen peroxide, MD520 (Durr), or sodium hypochlorite at 1% and 5.25% does not alter the dimensional stability significantly but reduces > 99.9% of the microbial load of the impressions (P<.001). CONCLUSION. Addition silicone impressions should always be disinfected after water wash in order to reduce effectively the cross-infection risk. All disinfectants tested showed high antimicrobial efficiency without significant changes in three-dimensional shape of impressions. Hydrogen peroxide and sodium hypochlorite are of particular importance because are easily accessible in dental setting. The less explored hydrogen peroxide could be a valuable alternative for silicone impressions disinfection.

• 대한의생명과학회지
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• 제27권4호
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• pp.264-269
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• 2021

The purpose of this study was to evaluate the disinfecting efficacy of peracetic acid (PAA), sodium hypochlorite (NaOCl) and phenol, which are representative disinfectants in medical environments using four types of multi-drug resistance (MDR) clinical isolates with healthcare-associated infections (HAI). 26 antibiotic susceptibility tests were conducted for the four types of MDR clinical isolates in the same way as for clinical specimens. The minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC) of the disinfectants were determined by using in vitro liquid medium dilution method and inoculation of the plate medium. Both the MIC and MBC of phenol against MRSA and VRE were 3.1%, while those against KPC and MRPA were 6.2%. The MIC and MBC of peracetic acid (PAA) against MRSA, VRE, KPC, and MRPA were 0.18%. The MIC and MBC of sodium hypochlorite (NaOCl) against MRSA were 0.39% and 0.78%, respectively. Both values of MIC and MBC were 0.78% for VRE. In addition, KPC and MRPA showed 0.39% for MIC and 0.78% for MBC. For all MDR strains used in this study, sodium hypochlorite and peracetic acid showed significant sterilizing efficiency, while no clear correlation was identified between antibiotic resistance clinical isolated and ability of disinfection.

• 한국식품위생안전성학회지
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• 제32권2호
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• pp.154-162
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• 2017

본 연구는 영양부추의 미생물학적 안전성을 확보하기 위하여 이산화염소와 차아염소산나트륨을 이용하여 미생물의 저감효과를 분석하고, 최적의 영양부추와 소독제의 비율을 결정하기 위하여 수행하였다. 이를 위하여 영양부추에 E. coli, Salmonella spp., S. aureus, B. cereus을 7.0 log CFU/g 정도로 접종 한 후 이산화염소는 3, 5, 10, 25, 100 ppm 차아염소산나트륨은 100, 150, 200 ppm에서 5, 10, 30, 60분간 처리하였으며, 또한 유기물이 이산화염소와 차아염소산나트륨의 효과에 미치는 영향을 분석하기 위해 영양부추와 소독제를 1 : 2, 1 : 4, 1 : 9, 1 : 19 비율로 처리하여 소독제의 효과를 분석하였다. 그 결과, 소독제의 농도에 따른 저감효과는 차아염소산나트륨 150 ppm, 이산화염소 50 ppm으로 30분간 처리시 일반세균수는 2.0 log CFU/g 정도 감소효과를 나타내었으며, 식중독세균은 차아염소산나트륨 100 ppm, 이산화염소 3 ppm에서 약 2.0 log CFU/g 정도 감소효과를 보였다. 한편, 이산화염소의 경우 50 ppm으로 30분간 영양부추를 처리할 경우 탈색 등 상품성이 저하되어 현장 적용이 어렵다고 판단되었다. 또한 영양부추와 소독제 처리 비율에 따른 미생물 저감효과는 일반세균의 경우 1:4에 비하여 1:9에서 유의적으로 높은 저감 효과를 보였다(p < 0.05). 확립된 기술을 영양부추 생산농장에 적용한 결과 일반세균수의 경우 2.7 log CFU/g, 대장균군의 경우 4.0 log CFU/g의 감소효과를 보였다. 따라서 영양부추를 세척이후 차아염소산나트륨 150 ppm에서 1:9 정도의 비율로 30분간 침지하면 미생물 안전성을 향상시킬 수 있으며, 최종 소비자에게 보다 안전한 부추의 공급이 가능할 것으로 판단된다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.124.2-124.2
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• 2010

Generally, a coolant of the nuclear power plant is manufactured by electrolyzing the sea water near the plant for making the sodium hypochlorite(NaOCl), which is used for sterilizing the bacteria and the shellfishes sticking to the drains or the pumps at the outlet of the cooling system due to $8-10^{\circ}C$ warmer temperature than the inlet sea water. During manufacturing the sodium hypochlorite, the hydrogen with the high purity is also produced at the anode side of the electrolyzer. This paper describes a novel power plant system combined with the polymer electrolyte membrane(PEM) fuel cell, the wasted hydrogen from the sea water electrolyzer and the wasted heat of the nuclear power plant. The present status over the exhausted hydrogen at twenty nuclear power plants in Korea was investigated in this study, from which an available power generation is estimated. Furthermore, the economic feasibility of the PEM fuel cell power plant is also evaluated by a current regulations over the power production and exchange using a renewable energy shown in Korea Power Exchange(KRX).

• Environmental Analysis Health and Toxicology
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• 제17권2호
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• pp.135-140
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• 2002

넙치는 단기간 NaOCl에 대한 노출에 대해 2ppm이하에서는 육안적으로 관찰시 심각한 이상증상이 관찰되지 않았으며, 조피볼락에서는 2.5ppm까지 급성적으로 안전하였다. 넙치와 조피볼락에서의 1시간 LC$_{50}$은 각각 3.24ppm 및 7.58ppm이었다. 조피볼락을 NaOCl로 1시간 노출시키고 혈액학적 및 혈장생화학적 변수를 측정하였을 때 2ppm이상의 농도에서 glucose의 농도가 현저히 상승한 부분을 제외하고는 생화학적 변수에도 이상이 발견되지는 않았다. Glucose는 거의 모든 종류의 stress에 의해서 신속히 증가하는 변수로서 이 시험에서 발견된 증가현상도 NaOCl이 가진 냄새 또는 화학적 자극성에 의한 stress의 결과로 나타난 것으로 추정된다.

• Restorative Dentistry and Endodontics
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• 제21권1호
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• pp.267-279
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• 1996

Microorganisms are implicated the endodontic treatment failures. Persistent endodontic infection may be the result of retention of microorganisms in the dentin of the root canal walls. Dentinal tubules of the root canal walls have been shown to harbor microorganisms. The purpose of this study was to investigate the invasion of microorganism into the root dentin and dentinal tubules. The effects of irrigation solutions and smear layer on bacterial colonization of root canal were evaluated using a scanning electron microscopy. Canals of extracted human teeth with single and straight canals were stepback prepared using normal saline. Tooth samples were divided into four groups according to the irrigation solutions -5 % sodium hypochlorite and normal saline-and smear layer treatment. The smear layer was removed by 5% NaOCl and 20% EDTA for 10 min respectively. After sterilization, they were incubated with each strains of Streptococcus sanguis, Enterococcus faecalis, Staphylococcus aureus and Escherichia coli. Sodium hypochlorite solution reduced the adhesion of microorganisms effectively compared to normal saline. The smear layer inhibited colonization of E. faecalis, S. aureus and E. coli in the root canals due to their blocking of dentianl tubules. But S. sanguis invaded dentinal tubules in the root canals without smear layer. It was suggested that bacterial attachment might be different according to the strains. Sodium hypochlorite inhibited bacterial attachment in the dentinal tubules dramatically. The absence or presence of smear layer affected bacterial invasion of the dentinal tubules.

• 대한치과의사협회지
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• 제53권12호
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• pp.958-966
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• 2015

Objective: Sodium hypochlorite (NaOCl) decreases the bond strength of resin composite. The purpose of this study was to compare the effect of antioxidant and superficial dentin surface removal on the microtensile bond strength of NaOCl-treated dentin. Materials and Methods: Twenty non-carious human third molars were used in this study. The dentin surfaces were treated with 5.25% NaOCl for 10 min, followed either by treatment with 10% ascorbic acid or superficial dentin surface removal. Two-step self-etch adhesive and resin composite were used for restoration. The bonded specimens were subjected to the microtensile bond strength test. Statistical analysis was performed using one-way analysis of variance (ANOVA) and Tukey's test (p < 0.05). Results: The bond strength after removal of the superficial dentin surface following NaOCl irrigation was similar to that in the control group. The group treated with 10% ascorbic acid demonstrated significantly higher bond strength than the other groups. Conclusion: NaOCl irrigation-induced reduction in dentin bond strength could be recovered by either treatment with 10% ascorbic acid or simple removal of the superficial dentin surface.