• Korean journal of food and cookery science
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• v.21 no.5
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• pp.703-708
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• 2005

The purposes of this study were to establish washing conditions for vegetable salad to reduce the microbial hazard by using sodium hypochlorite solution and eventually to implement HACCP for salad processing. By using the salad production line of Shinkeum Co. located in Gwacheon, Gyunggi-do, salad samples were washed under several washing conditions (chlorine dip period, chlorine concentration, rinse time, etc.) to determine the most effective conditions. The original washing line consisted of 3 baths (100 ppm chlorine water dip, water rinse, and water rinse), each with a capacity of 100 L of tap water and 5 kg of salad. First, the salad samples were washed with 100 ppm of sodium hypochlorite solution for various dip times (3, 6, 9, 12 min); however, only a 1 log- or less-reduction in total microbial counts was achieved in all groups and the time of chlorine water dip was not a significant factor in reducing the microbial hazard. When another water bath was added before the chlorine water dip (4-bath washing), a 2 log-reduction in total microbial counts was achieved. This result suggested the importance of pre-dipping salad materials in water before chlorine treatment to reduce the organic load on the surface of the vegetables. Coliforms were not detected at all after washing. As the concentration of chlorine $(50{\sim}150\;ppm)$ and rinse time $(0.5{\sim}2\;min)$ increased, greater microbial reduction was achieved; however, physical damage of the salad was observed. Finally, the optimum washing conditions for salad were determined as 3 min-water dip, 3 min-chlorine (100 ppm) dip, 2 min-rinse, and 2 min-rinse.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.242-247
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• 2003

Murine encephalomyocarditis virus (EMCV) has been used as a surrogate for hepatitis A virus (HAV) for the validation of virus removal and/or inactivation during the manufacturing process of biopharmaceuticals. Recently international regulation for the validation of HAV safety has been reinforced because of the reported cases of HAV transmission to hemophiliac patients who had received ntihemophilic factors prepared from human plasma. The purpose of the present study was to compare the resistance of HAV and EMCV to various viral inactivation processes and then to standardize the HAV validation method. HAV was more resistant than EMCV to pasteurization (60oC heat treatment for 10 hr), low pH incubation (pH 3.9 at 25oC for 14 days), 0.1 M NaOH treatment, and lyophilization. EMCV was completely inactivated to undetectable levels within 2 hr of pasteurization, however, HAV was completely inactivated to undetectable levels after 5 hr treatment. EMCV was completely inactivated to undetectable levels within 15 min of 0.1 M NaOH treatment, however, residual infectivity of HAV still remained even after 120 min of treatment. The log reduction factors achieved during low pH incubation were 1.63 for HAV and 3.84 for EMCV. Also the log reduction factors achieved during a lyophilization process of antihemophilic factor VIII were 1.21 for HAV and 4.57 for EMCV. These results indicate that HAV rather than EMCV should be used for the virus validation study and the validation results obtained using EMCV should be precisely reviewed.

• Journal of Applied Biological Chemistry
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• v.62 no.2
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• pp.181-186
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• 2019

The optimum design of LED device for irradiation of 460 nm blue light on extruded rice cake using simulation and the effect of the blue light on the inactivation of Bacillus cereus (B. cereus) group on the rice cake were investigated. The irradiated light intensity patterns on the surface area of the sample were simulated with three different LED arrays (centered, cross, and evenly spaced) and at various distances (22, 32, 42 mm) between the LED modules and the sample. In addition, the uniformity was calculated as Petri factor. The evenly spaced array resulted the most uniform light intensity pattern in the simulation, and the Petri factor of 32 and 42 mm of the distances showed higher than 0.9, which represents the ideal uniformity of LED device. The bacterial population of the rice cake decreased to less than the initial bacterial population during exposure to LED blue light, whereas the bacterial population of the control sample increased. The bacterial count of the rice cake after blue light irradiation for 24 h was 1.21 log CFU/g lower than the control sample. Petri factor increased with increase of the distance between the light source and sample, however, the reduction rate of B. cereus group decreased. Therefore, the design of LED device, that represented the Petri factor higher than 0.9 and inactivated the population of B. cereus group, with evenly spaced and 32 mm of distance between the light source and sample was suitable for extending shelf-life of rice cake.

• Journal of Microbiology and Biotechnology
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• v.18 no.5
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• pp.997-1003
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• 2008

Viral safety is a prerequisite for manufacturing clinical antihemophilic factor VIII concentrates from human plasma. With particular regard to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor VIII concentrate. The loss of factor VIII activity during dry-heat treatment was of about 5%. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor VIII compared with those of the factor VIII before dry-heat treatment. The dry-heat-treated factor VIII was stable for up to 24 months at $4^{\circ}C$. The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV, murine encephalomyocarditis virus (EMCV), and human immunodeficiency virus (HIV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Bovine herpes virus (BHV) and bovine viral diarrhea virus (BVDV) were potentially sensitive to the treatment. However porcine parvovirus (PPV) was slightly resistant to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\geq}5.55$ for HAV, ${\geq}5.87$ for EMCV, ${\geq}5.15$ for HIV, 6.13 for BHV, 4.46 for BVDV, and 1.90 for PPV. These results indicate that dry-heat treatment improves the virus safety of factor VIII concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid-enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

• Environmental and Resource Economics Review
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• v.31 no.4
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• pp.825-848
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• 2022

This paper analyzed the factors for increasing energy consumption in the domestic manufacturing sector using the LMDI (Log mean division index) decomposition method for the period from 1999 to 2019. Among the LMDI decomposition analysis methods, both additive and multiplicative factor decomposition methods were used. in this analysis. According to the result of the analysis, the factor that increased energy consumption in the domestic manufacturing industry was the production effect, and the structure effect and intensity effect were found to be the factors that decreased energy consumption. In particular, the reduction of energy consumption due to the structure effect was greater than that of energy consumption effect due to the intensity effect. By period, it can be seen that energy consumption increased rapidly due to the production effect until 2011, but after that, the increase in energy consumption due to the production effect slowed down. On the other hand, after that, the energy reduction effect due to the structure effect and the intensity effect became prominent. In order to save energy in the manufacturing sector in the future, energy diagnosis and management through EMS (Energy management system) and FEMS (Factory energy management system) are more necessary. In addition, restructuring into a low-energy consumption industry seems more necessary.

• Biotechnology and Bioprocess Engineering:BBE
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• v.11 no.1
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• pp.19-25
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• 2006

With particular regards to the hepatitis A virus (HAV), a terminal dry-heat treatment ($100^{\circ}C$ for 30 min) process, following lyophilization, was developed to improve the virus safety of a solvent/detergent-treated antihemophilic factor IX concentrate. The loss of factor IX activity during dry-heat treatment was of about 3%, as estimated by a clotting assay. No substantial changes were observed in the physical and biochemical characteristics of the dry-heat-treated factor IX compared with those of the factor IX before dry-heat treatment. The dry-heat-treated factor IX was stable for up to 24 months at $4^{\circ}C$, The dry-heat treatment after lyophilization was an effective process for inactivating viruses. The HAV and murine encephalomyocarditis virus (EMCV) were completely inactivated to below detectable levels within 10 min of the dry-heat treatment. Porcine parvovirus (PPV) and bovine herpes virus (BHV) were potentially sensitive to the treatment. The log reduction factors achieved during lyophilization and dry-heat treatment were ${\ge}5.60$ for HAV, ${\ge}6.08$ for EMCV, 2.64 for PPV, and 3.59 for BHV. These results indicate that dry-heat treatment improves the virus safety of factor IX concentrates, without destroying the activity. Moreover, the treatment represents an effective measure for the inactivation of non-lipid enveloped viruses, in particular HAV, which is resistant to solvent/detergent treatment.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.18 no.2
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• pp.3-10
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• 2008

The choice of basis for representation of element in $GF(2^m)$ affects the efficiency of a multiplier. Among them, a multiplier using redundant representation efficiently supports trade-off between the area complexity and the time complexity since it can quickly carry out modular reduction. So time of a previous multiplier using redundant representation is faster than time of multiplier using others basis. But, the weakness of one has a upper space complexity compared to multiplier using others basis. In this paper, we propose a new efficient multiplier with consideration that polynomial exponentiation operations are frequently used in cryptographic hardwares. The proposed multiplier is suitable fer left-to-right exponentiation environment and provides efficiency between time and area complexity. And so, it has both time delay of $T_A+({\lceil}{\log}_2m{\rceil})T_x$ and area complexity of (2m-1)(m+s). As a result, the proposed multiplier reduces $2(ms+s^2)$ compared to the previous multiplier using equally-spaced polynomials in area complexity. In addition, it reduces $T_A+({\lceil}{\log}_2m+s{\rceil})T_x$ to $T_A+({\lceil}{\log}_2m{\rceil})T_x$ in the time complexity.($T_A$:Time delay of one AND gate, $T_x$:Time delay of one XOR gate, m:Degree of equally spaced irreducible polynomial, s:spacing factor)

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.8
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• pp.1296-1303
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• 2014

This study was conducted to develop predictive models for the growth of Bacillus cereus on carrot treated with slightly acidic electrolyzed water (SAcEW) and ultrasonication (US) at different storage temperatures. In addition, the inactivation of B. cereus by US with SAcEW was investigated. US treatment with a frequency of 40 kHz and an acoustic energy density of 400 W/L at $40^{\circ}C$ for 3 min showed the maximum reduction of 2.87 log CFU/g B. cereus on carrot, while combined treatment of US (400 W/L, $40^{\circ}C$, 3 min) with SAcEW reached to 3.1 log CFU/g reduction. Growth data of B. cereus on carrot treated with SAcEW and US at different temperatures (4, 10, 15, 20, 25, 30, and $35^{\circ}C$) were collected and used to develop predictive models. The modified Gompertz model was found to be more suitable to describe the growth data. The specific growth rate (SGR) and lag time (LT) obtained from the modified Gompertz model were employed to establish the secondary models. The newly developed secondary models were validated using the root mean square error, bias factor, and accuracy factor. All results of these factors were in the acceptable range of values. After compared SGR and LT of B. cereus on carrot, the results showed that the growth of B. cereus on carrot treated with SAcEW and US was slower than that of single treatment. This result indicates that shelf life of carrot treated with SAcEW and US could be extended. The developed predictive models might also be used to assess the microbiological risk of B. cereus infection in carrot treated with SAcEW and US.

• Bulletin of the Society of Naval Architects of Korea
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• v.21 no.1
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• pp.35-42
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• 1984

In the present study, rotating bending fatigue tests have been carried out in three kinds of carbon steel specimens; an annealed low carbon steel, an annealed high carbon steel and quenched-tempered high carbon steel; with a small artificial surface defect that might exist in real structures. Fatigue crack lengths have been observed by a method of replication in order to investigate the growth characteristic of fatigue crack in the viewpoints of strength of materials and fracture mechanics. The main results obtained are as follows: 1) The effect of a small surface defect upon the reduction of fatigue limit is considerably large, and the rate of fatigue limit reduction grows in the following order; annealed low carbon steel(mild steel), annealed high carbon steel, quenched-tempered high carbon steel. 2) When the growth rate of surface crack length(2a) was investigated in the viewpoints of fracture mechanics based upon $ ${\Delta}K_{\varepsilon}$, the dependence of stress level and of surface defect size disappear, and there exists a linear relationships between d(2a)/dN and ${\Delta}K_{{\varepsilon}t},\;\Delta_{{\varepsilon}t}\sqrt{{\pi}a}$, on log. plot, i.e, $d(2a)/dN={C{\cdot}{\Delta}K_{\varepsilon}}^3_t$, where ${\Delta}_{{\varepsilon}t}\sqrt{{\pi}a}$ a is the cyclic total strain intensity factor range.

• Journal of Radiation Protection and Research
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• v.46 no.1
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• pp.8-13
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• 2021

Background: Salmonella enteritidis (SE) was the main cause of the pandemic of foodborne salmonellosis. The surface of eggs' shells can be contaminated with this bacterium; however, washing them with sodium hypochlorite solution not only reduces their flavor but also heavily impacts the environment. An alternative to this is surface sterilization using low-energy electron beam. It is known that irradiation with 1 kGy resulted in a significant 3.9 log reduction (reduction factor of 10,000) in detectable SE on the shell. FAO/IAEA/WHO indicates irradiation of any food commodity up to an overall average dose of 10 kGy presents no toxicological hazard. On the other hand, the Food and Drug Administration has deemed a dose of up to 3 kGy is allowable for eggs. However, the maximum dose permitted to be absorbed by an edible part (i.e., internal dose) is 0.1 Gy in Japan and 0.5 Gy in European Union. Materials and Methods: The electron beam (EB) depth dose distribution in the eggshell was calculated by the Monte Carlo method. The internal dose was also estimated by Monte Carlo simulation and experimentation. Results and Discussion: The EB depth dose distribution for the eggshells indicated that acceleration voltages between 80 and 200 kV were optimal for eggshell sterilization. It was also found that acceleration voltages between 80 and 150 kV were suitable for reducing the internal dose to ≤ 0.10 Gy. Conclusion: The optimum irradiative conditions for sterilizing only eggshells with an EB were between 80 and 150 kV.