• The Journal of Advanced Prosthodontics
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• v.5 no.1
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• pp.2-8
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• 2013

PURPOSE. Autoclaves and UV sterilizers have been commonly used to prevent cross-infections between dental patients and dental instruments or materials contaminated by saliva and blood. To develop a dental sterilizer which can sterilize most materials, such as metals, rubbers, and plastics, the sterilization effect of an atmospheric pressure non-thermal air plasma device was evaluated. MATERIALS AND METHODS. After inoculating E. coli and B. subtilis the diamond burs and polyvinyl siloxane materials were sterilized by exposing them to the plasma for different lengths of time (30, 60, 90, 120, 180 and, 240 seconds). The diamond burs and polyvinyl siloxane materials were immersed in PBS solutions, cultured on agar plates and quantified by counting the colony forming units. The data were analyzed using one-way ANOVA and significance was assessed by the LSD post hoc test (${\alpha}$=0.05). RESULTS. The device was effective in killing E. coli contained in the plasma device compared with the UV sterilizer. The atmospheric pressure non-thermal air plasma device contributed greatly to the sterilization of diamond burs and polyvinyl siloxane materials inoculated with E. coli and B. subtilis. Diamond burs and polyvinyl siloxane materials inoculated with E. coli was effective after 60 and 90 seconds. The diamond burs and polyvinyl siloxane materials inoculated with B. subtilis was effective after 120 and 180 seconds. CONCLUSION. The atmospheric pressure non-thermal air plasma device was effective in killing both E. coli and B. subtilis, and was more effective in killing E. coli than the UV sterilizer.

• YAKHAK HOEJI
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• v.49 no.2
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• pp.180-184
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• 2005

The purpose of this study was to develop the best methods to sterilize Moutan Root Bark which is frequently used as a herbal medicine, and known to have high susceptibility to m icrobial contamination. We used dry heat, gamma irradiation and alcohol gas treatment for sterilization, and evaluated these methods in terms of the followings; I) the efficacy of sterilization, and ii) the chemical alteration of a major component of the harbal medicines. Treatment with dry heat effectively got rid of contaminated microorganisms, and did not significantly alter the content of paeonol. However it seriously changed the color and morphology which are an essential criterion to estimate a measure of quality of medicinal herbs. Treatment with gamma irradiation showed a strong sterilizing effect, and no alteration of the content of paeonol, color and morphology. Alcohol gas treatment resulted in similar effects as those in gamma irradiation. Collectively, these results suggest that appropriate sterilizing methods to guarantee the microbial quality of this herbal medicine may be those using gamma irradiation or alcohol gas.

• Korean Journal of Food Science and Technology
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• v.16 no.2
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• pp.139-142
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• 1984

Effects of irradiation on the microbial growth and physicochemical properties of garlic powder were investigated during 3 months storage. Total bacteria and coliform group of garlic powder were $4.74{\times}10^{4}$ and $5.0{\times}10^{3}$ per g, respectively and irradiation of 5 kGy and 7 kGy could sterilize coliform group and total bacteria, respectively. $D_{10}$ value of total bacteria was 3.34 and no microorganisms were grown in 5 to f kGy irradiated groups after 3 months storage at $30{\pm}1^{\circ}C$. Moisture, sugars and pH of garlic powder were not remarkably changed during storage but pyruvic acid content was slightly decreased with storage period. Color difference of garlic powder after 3 months storage could not be distinguished by naked eye, but a slight change was recongized by the mechanical measurement.

• The Korean Journal of Pesticide Science
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• v.4 no.3
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• pp.1-6
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• 2000

In order to elucidate the degradation of the herbicide dicamba, the degradabilities of dicamba under sunlight and in soils were investigated. The photodegradation rate of the authentic dicamba under sunlight condition was only 3.3% after 9 weeks. 4-Hydroxy dicamba turned out to be the major product, and 5-hydroxy dicamba was also identified. Dicamba was degraded to 3,6-dichlorosalicylic acid by demethylation in the viable soil, which resulted in 14.7 to 23.2% degradation of the applied amount during 8 weeks of incubation. Meanwhile, the degradation was quite slow in the sterilize soil, which revealed that the soil microbes played a major role in dicamba degradation.

• 보존과학연구
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• s.19
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• pp.75-107
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• 1998

The cultural properties of paper made from 11 to 16th century of the Kirimsa temple were found in Birozana Buddhist Statue which was made from 15 to 16th century. These have been stored and exhibited in the exhibition showcase. To examine the environment of conservation and the state of paper, we investigated the temperature and the relative humidity in the inside and outside of the Kirimsa museum and examined the external form and the internal state (water content, acidity and whiteness) of paper. During the investigation period from 27 Aug. to 30 Aug. 1997. The average of temperature and relative humidity were $28.2^{\circ}C$, 67% in the outside and $27.1^{\circ}C$, 73% in the inside, respectively. These indicated the air conditioning was wrong. Among the cultural properties of 79 papers stored in the Kirimsa museum, 37 cases had been repaired but 42 cases not. From the result examining the external form, 20 cases needed to repair. In the internal state of the cultural properties of paper, the water contents were from 11.9% to 16.5%, the average was 15.7%, the acidities from pH 5.7 to pH 6.2 and the whiteness from 37 to 45. From these results, we could see the cultural properties of paper stored in the Kirimsa museum was damaged by the several factors (hydrolysis by fungi, repeated elongation and retraction of cellulose) caused mainly by the high temperature and relative humidity. Therefore, for the conservation of the cultural properties of paper stored in the Kirimsa museum, it need to control the temperature at $18~20^{\circ}C$ and the relative humidity at $55\pm5%$ by the appropriate air conditioning. In order to sterilize fungi occurred to the surface of paper, the cultural properties of paper needed to fumigate. The fungi occurred on the surface of paper were wiped out by using of 70%solution dissolved thymol in ethyl alcohol.

• Korean Journal of Organic Agriculture
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• v.7 no.1
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• pp.79-90
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• 1998

This study was conducted to effect promotion of fall potato growth in the place which green manual crops had been previously cultivated, crushed and tilled and polyethylene transparent vinyl had been mulched from Aug. 5 to Aug. 29 in 1997. The maximum temperature of below-ground at the depth of 10cm was $42^{\circ}C$ during the mulching period, and the pH and the organic compound content of soil was very increased by the cultivation of green manual crops and the mulching of polyethylene transparent vinyl. The total yields of green manual crops which had been previously cultivated were as the following orders; the hybrid of sudan grass, soybean, alfalfa, otherwise, fresh weight of stems and the tuber yield of fall potato were significantly affected in the plot of soybean + fall potato after the soil solarization with the mulching. As these results, it was possible to improve crops growth and to sterilize soil by the mulching treatment of polyethylene vinyl after cultivation of green manual crops during the high temperature of the summer season.

• Journal of Radiation Industry
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• v.5 no.3
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• pp.267-272
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• 2011

This study evaluated the microbial population (total aerobic count, fungi) and organoleptic quality of freeze-dried bibimbap sterilized by gamma irradiation to develop the space food. An irradiation dose above 30 kGy was needed to sterilize the freeze-dried bibimbap, while organoleptic quality of the sample was significantly decreased by irradiation (p<0.05). However, it was observed that scores on overall acceptance of rehydrated bibimbap after irradiation were the highest, when vitamin C and paprika extract were added at 0.1%, respectively. Therefore, it was considered that the freeze-dried bibimbap could be developed as a space food, which meet microbial requirements and organoleptic quality through addition of vitamin C 0.1% and paprika extract 0.1% before gamma irradiation at 30 kGy.

• Journal of Radiation Industry
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• v.4 no.1
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• pp.59-64
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• 2010

This study was conducted to evaluate the microbial (Total aerobic count, Coliform, Coagulase positive Staphylococci, Salmonella, Yeast/Mold, Escherichia coli, Bacillus cereus), Hunter'color values ($L^*$, $a^*$, $b^*$) and organoleptic quality of freeze-dried Miyeokguk, Korean seaweed soup in space food. Bacillus cereus was 1 log level while not detected in the sample irradiated at 10 kGy. Hunter's color values of the samples irradiated less than 10 kGy was not significantly different (p>0.05). The sensory evaluation result showed that the preference scores in all the sensory properties decreased when it was irradiated over 10 kGy, but sensory score of less than 10 kGy samples was similar in all terms. Therefore, it was considered that gamma irradiation at 10 kGy was enough to sterilize the freeze-dried Miyeokguk without deterioration of sensory quality.

• Journal of Radiation Industry
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• v.7 no.2_3
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• pp.177-182
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• 2013

This study was conducted to evaluate the effect of gamma irradiation on the microbial populations of dried raw materials (9 products) and Saengsik powder. The samples were gammairradiated at doses of 2, 4, 6 and 8 kGy and the microbiological populations were evaluated. The total numbers of bacteria and Bacillus cereus in non-irradiated dried-raw materials for Saengsik powder was 1.3~3.4 and $1.7{\sim}2.4log\;CFU\;g^{-1}$. However, gamma irradiation reduced the microbiological populations in all samples, and Saengsik powder were sterilized at more than 6 kGy. Moreover, Clostridium perfringens were not observed in all samples within detection limit (<$1log\;CFU\;g^{-1}$). Therefore, the results of this study suggest that gamma irradiation at 6 kGy is sufficient to sterilize Saengsik powder, and thus, irradiated Saengsik powder at 6 kGy fulfills the microbiological requirements for sterilized food.

• Journal of Radiation Industry
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• v.6 no.3
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• pp.239-244
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• 2012

This study was conducted to investigate bacterial growth, viscosity, color, and sensory properties of gamma-irradiated Tarakjuk powder, a Korean milk porridge powder, at 1, 3, 5, 7, and 10 kGy. The total aerobic bacteria in non-irradiated Tarakjuk powder was $2.56{\log}\;CFU{\cdot}g^{-1}$, whereas it was not observed within the detection limit of $2{\log}\;CFU{\cdot}g^{-1}$ in samples irradiated at more than 1 kGy. Spore-forming bacteria, however, were not observed in all samples within the detection limit of $1{\log}\;CFU{\cdot}g^{-1}$. The viscosity of rehydrated Tarakjuk after gamma irradiation significantly decreased from 16,770 cP to 4,060 cP when irradiated at 10 kGy. The redness ($a^*$ value) and yellowness ($b^*$ value) evaluated using a colorimeter were significantly increased according to the increase in irradiation dose (p<0.05), while there was no difference in color evaluation conducted by panels. The overall acceptance decreased as the irradiation dose increased, and the 5 kGy sample was 4.0 (normal) on a 7-point scale. As a result, it is considered that a gamma irradiation of 5 kGy is enough to sterilize Tarakjuk powder with a acceptable sensory quality.