• Journal of Conservation Science
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• v.30 no.2
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• pp.137-148
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• 2014

Large scale anoxic chamber system(volume $28m^3$) was developed and installed at The National Folk Museum of Korea for the first time in Korea. In order to get optimal anoxic treatment condition, we compared the disinfection of adults, larvae and eggs of cigarette beetles using nitrogen and argon. The time for complete disinfection of cigarette beetles in pine wooden blocks exposed to nitrogen at oxygen concentration 0.01% and 50% in relative humidity were 15 days at $20^{\circ}C$, 10 days at $25^{\circ}C$, and 7 days $30^{\circ}C$. Time were 10 days at $20^{\circ}C$, 7 days at $25^{\circ}C$, and 5 days $30^{\circ}C$ in argon anoxic atmosphere. From the mortality of cigarette beetles, optimal disinfection condition was oxygen concentration 0.01%, $25^{\circ}C$ in temperature, 50% in relative humidity and exposure time 21 days at nitrogen atmosphere. And when large scale anoxic chamber system was supplied nitrogen by nitrogen generator for anoxic treatment of many collections or large collections, it could be operated stably. To verify optimal disinfection condition, museum insects(adults, larvae, pupae and eggs of cigarette beetles in pine wooden blocks, cotton fabrics and Korean paper book, adults and larvae of drugstore beetles in pine wooden blocks, cotton fabrics and Korean paper book, larvae of varied carpet beetles in pine wooden block and silk fabrics, adults and larvae of hide beetles and adults of rice weevils in breeding boxes) which exposed at optimal disinfection condition, were completely killed.

• Applied Chemistry for Engineering
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• v.19 no.1
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• pp.122-128
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• 2008

We evaluated the relationship between the multiplication of heterotrophic microorganisms and physicochemical factors in the final discharged sewage water from J municipal waste water treatment plants. Dissolved organic carbon (DOC) was the most crucial factor influencing multiplication of heterotrophic plate counts (HPC) among the water quality variables selected. Degrading bacteria, such as proteolytic bacteria, lipholytic bacteria, starch degrading bacteria, cellulolytic bacteria, and pectinolytic bacteria, were monitored to understand the condition of nutrients in finished sewage effluent. The percentages of lipid and protein combined occupied 81% in finished sewage water. The multiplication of HPC showed the highest value in August. The formation of trihalomethane (THM) was low in the finished discharge water during chlorine disinfection, which was $71{\mu}/L$ (which was less than $100{\mu}/L$- the standard of drinking water quality) with 10 mg/L of chlorine during 15 min.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.12
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• pp.1141-1146
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• 2010

Isolated the heterotrophic aerobic bacteria in sandfiltered water on NA and TSBA solid medium, selected 8 dominant species and identified by Sherlock System. Each samples are irradiated 0, 5, 16, 40 and $60\;mJ/cm^2$ using on CBD (Collimated Beam Device) Medium Pressure UV lamp after these identified bacterium did liquid culture how to make $10^6{\sim}10^7\;cells/mL$ suspended in dilution water. Then cultured bacteria are estimated inactivation rate on plate media. Identified Gram positive group are Bacillus Subtilus, Bacillus megaterium, Rhodococcus erythropolis and Microbacterium laevaniformans; Gram negative group are Pseudomonas vesicularis, Pseudomonas pseudoflava, Alcaligenes paradoxus and Zooglea ramigera. These isolation of bacterium are more stronger reference strain and high resistance of MP UV irradiation, Besides Gram negative bacterium are more sensitive Gram positive bacterium on MP UV dose. Now we are estimating to $60{\sim}100\;mJ/cm^2$ MP UV dose for efficient disinfection in water treatment plant.

• Journal of Korean Society of Environmental Engineers
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• v.37 no.9
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• pp.505-510
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• 2015

This study investigated formation potential of 16 disinfection byproducts (DBPs) (e.g., g trihalomethanes, haloacetic acids, haloacetonitriles, chloral hydrate, etc.) upon chlorination of raw water at various pH, water temperatures, and chlorine doses. We also compared the DBP formation potential (DBPFP) of raw and filtered waters. Most of DBPs were formed higher at neutral pH, but dichloroacetic acid, chloroform, and bromodichloromethane were formed higher over pH 7. As water temperature increased, concentrations of chloral hydrate, haloacetic acids, and haloacetonitriles linearly increased while that of trihalomethanes exponentially increased. Formation of chloral hydrate, trihalomethanes, and trihaloacetonitriles significantly increased up to 2.0 mg/L $Cl_2$ of chlorine addition, then gradually increased at 2.0~5.6 mg/L $Cl_2$. Filtered water formed less DBPs than raw water in most DBPs except for trihalomethanes.

• Journal of Korean Society of Environmental Engineers
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• v.29 no.2
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• pp.192-196
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• 2007

In this study, a formation of N-nitrosodimethylamine(NDMA), a disinfection by-product, was investigated as a result of monochloramine addition in water. The NDMA formation was studied in terms of pH, dimethylamine(DMA), monochloramine concentration, and nitrogen composition in monochloramine. At a fixed DMA concentration of 0.01 mM or 0.05 mM, the NDMA formed concentration was quite different when the monochloramine to DMA ratio is less or greater than 1. The NDMA formation increased with increasing pH and a ratio of nitrogen composition in monochloramine to total nitrogen composition. At pH 7 and 8, more than five times higher NDMA formation was produced as a result of five times increase in DMA concentration. It was likely that monochloramine could be related to stimulate NDMA formation, if monochloramine may be produced with chlorine disinfection, in water treatment systems.

• Journal of Korean Society of Water and Wastewater
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• v.32 no.5
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• pp.421-434
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• 2018

Water supply/intake pumps operation use 70~80% of power costs in water treatment plants. In the water treatment plant, seasonal and hourly differential electricity rates are applied, so proper pump scheduling can yield power cost savings. Accordingly, the purpose of this study was to develop an optimal water supply pump scheduling scheme. An optimal operation method of water supply pumps by using genetic algorithm was developed. Also, a method to minimize power cost for water supply pump operation based on pump performance derived from the thermodynamic pump efficiency measurement method was proposed. Water level constraints to provide sufficient disinfection performance in a clearwell and reservoirs were calibrated. In addition, continuous operation time constraints were calibrated to prevent frequent pump switching. As a result of optimization, savings ratios during 7 days in winter and summer were 4.5% and 5.1%, respectively. In this study, the method for optimal water pump operation was developed to secure disinfection performance in the clearwell and to save power cost. It is expected that it will be used as a more advanced optimal water pump operation method through further studies such as water demand forecasting and efficiency according to pump combination.

• Journal of Sericultural and Entomological Science
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• v.19 no.1
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• pp.19-23
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• 1977

In the previous short communication, the authors reported the applicability of Sodium Hyplochoride solution to silkworm rearing industry as a disinfectant after confirmed the fact that the chemical agent is capable to kill most of the pathogens of silkworm diseases. The authors, in the present study, attempted to investigate the influence of the chemical on the growth of silkworm larvae and the effect on the disinfection of silkworm larvae to inactivate the pathogen of yellow muscardine disease, Isaria farinosa and the results obtained are summarized as fellows. 1. The chemical agent did not affect the growth of silkworm larvae, when it was applied on silk-worm body with the concentration of 1,3,5 per cent of the agent during the rearing period. 2. The Sodium Hypochloride solution did not give any damage to silkworm larvae when larvae were fed up with 1,3,5 per cent of the solution. 3. In the bioassay of the solution on disinfection of larvae inoculated with yellow muscardine disease pathogen, the fact that the agent could control the disease was observed by showing much low infection rate in 3.5 per cent treatment compared to non-treatment control.

• Journal of Digital Convergence
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• v.16 no.5
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• pp.299-307
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• 2018

This study survey research of infection control, wastewater management, and instrument disinfection according to characteristic at Daegu, Gyeongbuk Province In 2012 and 2017, the same 114 dental clinics to identify the infection management behavior and prevent infection of dental medical institutions. Scored mean 3.37 points on 8 items of infection control, 95.5% in "records of the patient's medical history", 1.8% in "presence of a wastewater facility." Scored 94.7% in "disinfection of metal trays", 17.5% in "storage from a spitting receptacle in the waste bin and commissioned management.", Scored higher in of infection control, wastewater management and instrument disinfection according to general characteristics and dental characteristics in 2017 than in 2012. Points were higher dental hygienist, University graduation, Type of duty was counseling and management, hospital or higher, Number of dentist(dental hygienist, chair, patient) was high. Therefore raise a need for infection control into consideration the dental characteristics and education and promotion regardless of the hospital size.

• Journal of Periodontal and Implant Science
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• v.37 no.3
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• pp.613-624
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• 2007

Full-mouth disinfection (Fdis) completes the entire scaling and root planing (SRP) in one stage within 24 hours for the prevention of microbial recolonization from untreated sites and ecological niches. The aim of this study is to compare the clinical short-term effects of modified Fdis with those of the conventional SRP in the therapy of moderate and severe chronic periodontitis. Modified Fdis group (5 patients) received the entire SRP within 24 hours using chlorhexidine solution (0.1%) and conventional SRP group (5 patients) received SRP per quadrant at one-week intervals. Clinical parameters were measured at baseline, one month and three months after both therapies. The results of this case report were as follows: 1. There were considerable decreases in sulcus bleeding index and plaque index one month after Fdis. 2. The mean probing depth of single-rooted teeth decreased more in Fdis group than conventional SRP group after therapy and, that of multi-rooted teeth decreased similarly in both groups. 3. The mean probing depth decreased 1.77mm in case of initial probing depth of 4-6mm and it decreased 4.13mm in case of initial probing depth of ${\geq}$ 7mm three months after Felis. 4. There were the smaller increases in gingival recession together with the larger gains in attachment in Fdis group than conventional SRP group after three months. Within the limitations of this study, one could conclude that Fdis has beneficial clinical effects in the treatment of moderate and severe chronic periodontitis and further research would be helpful including more subjects during a longer period to confirm the beneficial long-term effects of Fdis.

• Journal of Periodontal and Implant Science
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• v.39 no.sup2
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• pp.239-251
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• 2009

Purpose: Full-mouth disinfection enables to reduce the probability of cross contamination from untreated pockets to treated ones, for completing the entire SRP under local anesthesia with chlorhexidine as a mouth wash in two visits within 24 hours. This study aimed to compare the clinical effects of modified full-mouth disinfection (Fdis) after 6 months with those of conventional SRP (cSRP). Methods: Thirty non-smoking chronic periodontitis subjects were randomly allocated two groups. The Fdis group underwent the entire SRP under local anesthesia in two visits within 24 hours, a week after receiving supragingival scaling. A chlorhexidine (0.1%) solution was used for rinsing and subgingival irrigation for Fdis. The cSRP group received SRP per quadrant under local anesthesia at one-week intervals, one week after they had received scaling. Clinical parameters were recorded at baseline, after 1, 3 and 6 months. Results: There are significant (P<0.05) decreases in the sulcus bleeding index, and plaque index, and the increases in gingival recession were significantly smaller with Fdis after six months compared with cSRP. There was significant improvement in the probing depth and clinical attachment level for initially medium-deep pockets (4-6mm) after Fdis compared with cSRP. Multi-rooted teeth showed significantly larger attachment gain up to six months after Fdis. Single-rooted teeth showed significantly more attachment gain, 1 and 6 months after Fdis. Conclusions: Fdis has more beneficial effects on reducing gingival inflammation, plaque level, probing depth, gingival recession and improving clinical attachment level over cSRP.