• Journal of Food Hygiene and Safety
• /
• v.27 no.1
• /
• pp.18-23
• /
• 2012

Highly pathogenic avian influenza virus (HPAIV) is already panzootic in poultry and caused a considerable economic loss in poultry industry. In addition, HPAIV continues to cross species barriers to infect humans and other mammals, often with fatal outcomes. In this study, the virucidal efficacy of Citra-$Kill^{(R)}$ composed to quaternary ammonium chloride and citric acid was investigated against avian influenza H9N2 virus (AIV). A virucidal efficacy was determined with the viability of AIV contacted with the disinfectant in the allantoic membrane of chicken embryos. Citra-$Kill^{(R)}$ and AIV was reacted on the distilled water (DW), hard water (HW) or organic matter suspension (OM) condition. On DW condition, AIV was inactivated with 2,000 fold dilutions of Citra-$Kill^{(R)}$. When the antiviral effect on HW condition was evaluated, the antiviral activity of the disinfectant showed on 1,500 fold dilutions against AIV. With the investigation of the antiviral effect of the disinfectant on OM condition, AIV was inactivated on 500 fold dilutions of Citra-$Kill^{(R)}$. As Citra-$Kill^{(R)}$ possesses virucidal efficacy against AIV, the disinfectant solution can be used to limit the spread of animal viral diseases.

• Journal of Food Hygiene and Safety
• /
• v.31 no.4
• /
• pp.299-303
• /
• 2016

Salmonella spp. and Brucella spp. can cause considerable diseases on both humans and animals. In addition, these microorganisms cause the economic loss in animal farming and food industry. In this study, the disinfection efficacy of a disinfectant spray, composed to grapefruit seed extract, citric acid, malic acid and benzalkonium chloride, was evaluated against S. Typhimurium and B. ovis. A bactericidal efficacy test by broth dilution method was used to determine the lowest effective dilution of the disinfectant following exposure to test bacteria for 30 min at $4^{\circ}C$. The disinfectant and test bacteria were diluted with hard water (HW) or organic matter suspension (OM) according to treatment condition. On HW condition, the bactericidal activity of the disinfectant spray against S. Typhimurium and B. ovis was 5 and 4 fold dilutions, respectively. On OM condition, the bactericidal activity of the disinfectant spray was 2 and 1 fold dilutions against S. Typhimurium and B. ovis, respectively. As the disinfectant spray possesses bactericidal efficacy against foodborne pathogens such as S. Typhimurium and B. ovis, the disinfectant spray can be used to control the spread of bacterial diseases.

• Proceedings of the Korean Institute Of Construction Engineering and Management
• /
• autumn
• /
• pp.232-239
• /
• 2001

Young Jong Grand Bridge is approach traffic road of New Inchon International Airport which covers hub airport function in northeast asia. The total span length of this bridge is $4,420{\cal}m$ and this main bridge type is, the first in the world, Double Deck Self Anchored Suspension Bridge, designed as double deck systems to be arranged by road and railroad. Approach bridges to be connected with main span also are composed double deck steel truss and steel box girder to consider a continuity with this span. Our company erected $1,375{\cal}m$(about 60,000tons) of double deck steel truss bridge type which is composed by 6 traffic lane on upper deck and 4 traffic lane and Double track railroad on lower deck. The original installation method of this bridge was planed to install about 75 meters bridge blocks to use floating crane, after temporary bent was constructed between permanent piers. But this method which had to construct many temporary bents in the sea had the matter that construction periods can become lengthen and construction cost can be risen. To overcome the uncertainty to ensure high qualify of bridge and economic project execution, our company developed new bridge erection method to assure both quality control and economic construction work. The new erection method which was developed by us was one that could transport and install long bridge block, $120{\cal}m$ unit at a time and that temporary bent was not required. We hope that this paper is used as technical data which will erect bridge in the western sea and others marine region.

• The Journal of the Institute of Internet, Broadcasting and Communication
• /
• v.17 no.2
• /
• pp.245-250
• /
• 2017

From the instant of installation and operation, power cables start deteriorating. Cable systems can be maintained not only by monitoring the insulation status of the insulation layer and oversheath, but also the insulation status of the terminal and junction in high-voltage power cables. When the cable system (the cable itself and cable junctions combined) deteriorates, fire accidents happen due to dielectric breakdowns. We have invented a device to monitor the deteriorating status of cables, and installed it at Korea Western Power Co. Ltd. located in Taean, Chungcheongnam-do Province. In this paper, we present the results obtained using our device, through analysing and calculating the standard deviation of leakage current from cable insulators attached to the cables. When the standard deviation of analysed leakage current falls below a critical value, a cable system is deemed to be operating safely. But when the standard deviation of analysed leakage current is larger than the critical value, the insulation status of the terminal and junction in the cable system is considered to have seriously deteriorated. The terminal and junction in the relevant system should then be replaced preemptively in order to prevent blackout accidents of cables caused by the suspension of power supply.

• Journal of Navigation and Port Research
• /
• v.27 no.1
• /
• pp.97-102
• /
• 2003

Wire ropes are used in a myriad of various industrial applications such as elevator, mine hoist, construction machinery, lift, and suspension bridge. Especially, the wire rope of crane is important component to container transfer. If it happens wire rope failures during the operation, it may lead to safety accident, economic loss by productivity decline and so on. To solve this problem, we developed remote wire rope fault detecting system, and this system is consisted of 3 parts that portable fault detecting part, signal processing part and remote monitoring part. All detected signal has external noise or disturbance according to circumstances. So, we applied to discrete wavelet transform to extract a signal from noisy data. It is verified that the detecting system by de-noising has good efficiency for inspecting faults of wire ropes in service. As a result, by developing this system, container terminal could reduce expense because of extension fo wire ropes exchange period and could competitive power. Also, this system is possible to apply in several field such as elevator, lift and so on.

• 대한공업교육학회지
• /
• v.41 no.2
• /
• pp.134-150
• /
• 2016

This study has analyzed the subjects of transportation technology problem solving activities at Energy and Transportation Technology unit in the 12 kinds of middle school Technology Home Economics textbooks of the 2009 national revised curriculum. An analysis frame was developed with systems and environmental mediums which are common elements of transportation and the subjects were analyzed. As a result of this study, first, 8 kinds of subjects among 20 subjects in analysis frame were suggested in the textbooks. Second, according to the environmental, there are 13 terrestrial activities, 2 atmospheric activities, and 1 marine activity in the textbooks. However, there is no space related activity. Third, according to the system, there are 13 activities for the structure, 12 activities for the propulsion and suspension system, 5 activities related to the control system, and 1 activity regarding guidance system. Fourth, there are 4 kinds of problem solving activities depending on categorizing result of the analysis of the activities.

• Journal of Food Hygiene and Safety
• /
• v.29 no.3
• /
• pp.217-222
• /
• 2014

This study was performed to evaluate the sporicidal efficacy of a fumigation disinfectant containing 20% ortho-phenylphenol against Clostridium perfringens (C. perfringens) spores. In this research, efficacy test of fumigant against C. perfringens spores was carried out according to French standard NF T 72-281. C. perfringens spores working culture suspension number (N value), all the spore numbers on the carriers exposed with the fumigant (n1, n2, and n3), the number of bacterial spore suspensions by pour plate method (N1), the number of bacterial spore suspensions by filter membrane method (N2) and the mean number of bacterial spore recovered on the control-carriers (T value) were obtained from the preliminary test. In addition, the reduction number of C. perfringens spores exposed with the fumigant (d value) was calculated using T value, the mean number of bacterial spore in recovery solution (n'1) and the mean number of bacterial spore on carriers plated in agar (n'2). N value was $4.3{\times}10^7spores/mL$, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, T value was $4.9{\times}10^5spores/carrier$. In the sporicidal effect of the fumigant, the d value was 4.52log reduction. According to the French standard for the fumigant, the d value for the effective sporicidal fumigant should be over than 3log reduction. The results indicated that Fumagari $OPP^{(R)}$ had an efficient sporicidal activity against spores of C. perfringens, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with bacterial spores.

• Journal of Food Hygiene and Safety
• /
• v.28 no.4
• /
• pp.349-353
• /
• 2013

This study was performed to evaluate the bactericidal efficacy of Fumagari OPP$^{(R)}$, fumigation disinfectant, containing 20% ortho-phenylphenol against Staphylococcus aureus (S. aureus). In this research, efficacy test of fumigant against S. aureus was carried out according to French standard NF T 72-281. S. aureus working culture suspension number (N value), all of the colony numbers on the carriers exposed with the fumigant (n1, n2, and n3), the number of bacterial test suspentions by pour plate method (N1), the number of bacterial test suspentions by filter membrane method (N2) and the mean number of bacteria recovered on the control-carriers (T value) were obtained from the preliminary test. In addition, the reduction number of S. aureus exposed with the fumigant (d value) was calculated using T value, the mean number of bacteria in recovery solution (n'1) and the mean number of bacteria on carriers plated in agar (n'2). N value was $4.0{\times}10^8$ CFU/mL, and n1, n2, and n3 were higher than 0.5N1, 0.5N2 and 0.5N1, respectively. Additionally, T value was $3.4{\times}10^6$ CFU/mL. In the bactericidal effect of the fumigant, the d value was 6.43 logCFU/mL. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. The results indicated that Fumagari OPP$^{(R)}$ had an effective bactericidal activity against S. aureus, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with pathogenic bacteria.

• Korean Journal of Poultry Science
• /
• v.40 no.3
• /
• pp.197-205
• /
• 2013

This study established a method for preserving chicken primordial germ cells (PGCs) that enables long-term storage in liquid nitrogen ($LN_2$) for preservation of the species. The purpose of this study was to compare the effects of Ethylene Glycol (EG) and Propylene Glycol (PG) on viability of cryopreserved PGCs with vitrification in Korean Native Chicken (Ogye), and to fine should be find or to the optimal protocol for PGCs freezing. One of the important components of cryopreservation process is cryopreservation medium that plays a vital role in preventing cellular injury during freeze-thawing. Cryoprotective agents have been known to improve cell viability after freeze-thawing. PGCs obtained from the germinal gonade of 5.5~6 day (stage 28) chick embryos, using the MACS method were suspended in a freezing medium containing a freezing and protecting agents. Gonads were harvested from stage 28 chick embryos and pooled in groups of 10E embryos, contributing gonads to the cell suspension. The gonadal cells, including PGCs, were then frozen in 1 of the following cryoprotectant treatments: 2.5% EG, 5% EG, 10% EG, 2.5% PG, 5% PG, 10% PG, and 0% cryoprotectant as a control. Effects of exposure to vitrification solution and vitrification, with different concentrations of the cryoprotectant solution, were examined. After freezing and thawing, survival rates of the frozen-thawed PGCs from the 0, 2.5, 5, 10 and 15% EG plus FBS treatment were 44.24%, 64.51%, 85.63%, 80.51% and 73.52% (p<0.05), respectively. The viability of PGCs after freeze-thawing was significantly higher for 10% EG plus FBS treatment than for 10% PG + FBS treatment (p<0.05)(85.63% vs 66.81%). Therefore, these systems may contribute in the improvement of cryopreservation for a scarce species in birds preservation. This study established a method for preserving chicken PGC that enables systematic storage and labeling of cryopreserved PGCs in liquid N at a germplasm repository and ease of entry into a database. In the future, the importance for this new technology is that poultry lines can be conserved while work is being conducted on improving the production of germline chimeras.

• Journal of Food Hygiene and Safety
• /
• v.29 no.1
• /
• pp.60-66
• /
• 2014

This test was performed to evaluate the bactericidal efficacy of a fumigation disinfectant containing 20% ortho-phenylphenol against Pseudomonas aeruginosa (P. aeruginosa) and Enterococcus hirae (E. hirae). In preliminary tests, P. aeruginosa and E. hirae working culture suspension number (N value) were $2.8{\times}10^8$ and $4.0{\times}10^8CFU/mL$, respectively. And all the colony numbers on the carriers exposed to the fumigant (n1, n2, n3) were higher than 0.5N1 (the number of bacterial test suspentions by pour plate method), 0.5N2 (the number of bacterial test suspentions by filter membrane method) and 0.5N1, respectively. In addition, the mean number of P. aeruginosa and E. hirae recovered on the control-carriers (T value) was $2.8{\times}10^8$ and $3.4{\times}10^6CFU/mL$, respectively. In the bactericidal effect of the fumigant, the reduction number of $2.8{\times}10^8$ (d value) was 6.46 and 5.19 logCFU/mL, respectively. According to the French standard for the fumigant, the d value for the effective bactericidal fumigant should be over than 5 logCFU/mL. With the results from this study, the fumigation disinfectant containing 20% ortho-phenylphenol has an effective bactericidal activity, then the fumigant can be applied to disinfect food materials and kitchen appliances contaminated with the pathogenic bacteria.