• Korean Journal of Food Science and Technology
• /
• v.53 no.6
• /
• pp.799-808
• /
• 2021

This study was performed to investigate the extent of microbial contamination, the presence of enterotoxin genes, and the antibiotic susceptibility of Bacillus cereus in 58 red pepper plants and 43 environmental samples (soil, irrigation water, and gloves) associated with the plant cultivation. The detected counts of total aerobic bacteria, coliform bacteria, Escherichia coli, Bacillus cereus, and Staphylococcus aureus were lower in these samples, as compared to the regulations of standards for foods; moreover, pathogens, such as E. coli, E. coli O157:H7, Listeria monocytogenes, and Salmonella spp., were not detected. Genes encoding hemolysin BL enterotoxins (hblA, hblC, and hblD) as well as non-hemolytic enterotoxins (nheA, nheB, and nheC) were detected in 23 B. cereus specimens that were isolated from the test samples and had β-hemolytic activity. Interestingly, B. cereus is resistant to β-lactam and susceptible to non-β-lactam antibiotics. However, in this case, the isolated B. cereus specimens exhibited a shift from resistant to intermediate in response to cefotaxime and from susceptible to intermediate in case of rifampin, trimethoprim-sulfamethoxazole, vancomycin, clindamycin, and erythromycin. Therefore, the levels of B. cereus should be monitored to detect changes in antibiotic susceptibility and guarantee their safety.

• Clean Technology
• /
• v.27 no.4
• /
• pp.332-340
• /
• 2021

With the recent reinforcement of emission standards, it is necessary to make efforts to reduce NOx from air pollutant-emitting workplaces. The NOx reduction method mainly used in industrial facilities is selective catalytic reduction (SCR), and the most commercial SCR catalyst is the ceramic honeycomb catalyst. This study was carried out to reduce the NOx emitted from steel plants by applying De-NOx catalyst coated on metallic monolith. The De-NOx catalyst was synthesized through the optimized coating technique, and the coated catalyst was uniformly and strongly adhered onto the surface of the metallic monolith according to the air jet erosion and bending test. Due to the good thermal conductivity of metallic monolith, the De-NOx catalyst coated on metallic monolith showed good De-NOx efficiency at low temperatures (200 ~ 250 ℃). In addition, the optimal amount of catalyst coating on the metallic monolith surface was confirmed for the design of an economical catalyst. Based on these results, the De-NOx catalyst of commercial grade size was tested in a semi-pilot De-NOx performance facility under a simulated gas similar to the exhaust gas emitted from a steel plant. Even at a low temperature (200 ℃), it showed excellent performance satisfying the emission standard (less than 60 ppm). Therefore, the De-NOx catalyst coated metallic monolith has good physical and chemical properties and showed a good De-NOx efficiency even with the minimum amount of catalyst. Additionally, it was possible to compact and downsize the SCR reactor through the application of a high-density cell. Therefore, we suggest that the proposed De-NOx catalyst coated metallic monolith may be a good alternative De-NOx catalyst for industrial uses such as steel plants, thermal power plants, incineration plants ships, and construction machinery.

• Particle and aerosol research
• /
• v.14 no.4
• /
• pp.153-169
• /
• 2018

To identify a variety of organic compounds in the ambient aerosols, the two-dimensional gas chromatography-time of flight mass spectrometry (GCxGC) system (2DGC) has been applied. While 2DGC provides more peaks, the amount of the generated data becomes huge. A two-step approach has been proposed to efficiently interpret the organic aerosol analysis data. The two-dimensional 2DGC data were divided into 6 chemical groups depending on their volatility and polarity. Using these classification standards, all the peaks were subject to both qualitative and quantitative analyses and then classified into 8 classes. The aerosol samples collected in Seoul in summer 2013 and winter 2014 were used as the test case. It was found that some chemical classes such as furanone showed seasonal variation in the high polarity-volatile organic compounds (HP-VOC) group. Also, for some chemical classes, qualitative and quantitative analyses showed different trends. Limitations of the proposed method are discussed.

• Journal of Food Hygiene and Safety
• /
• v.34 no.1
• /
• pp.94-99
• /
• 2019

The objective of this study is to establish the shelf life of non-pasteurized whole egg, egg yolk and egg white liquid. Each sample was stored for two weeks at $5^{\circ}C$, $10^{\circ}C$, $15^{\circ}C$, and $25^{\circ}C$, and then sensory, microbial, and physicochemical tests were performed periodically. The estimation of shelf life was based on the microbial standards of total viable counts and coliforms. The chemical properties highly correlated with the sensory evaluation were also used. Our results showed that the shelf life was the most influenced by microbial properties. Exceptionally, however, whole egg and white liquid stored at $5^{\circ}C$ and $10^{\circ}C$ with limited bacterial growth were affected by chemical property. The shelf life of the three non-pasteurized liquids was calculated to be less than one day at over $15^{\circ}C$. At $5^{\circ}C$ and $10^{\circ}C$, the shelf life was calculated to be 5 d and 1 d for egg yolk liquid, 5 d and 5 d for egg white, and 7 d and 5 d for whole egg, respectively. Therefore, it is advisable to establish reasonable shelf life in the more specific manner based on consideration of these findings.

• Journal of Food Hygiene and Safety
• /
• v.36 no.3
• /
• pp.264-270
• /
• 2021

In this study we investigated the elution level of lead (Pb), cadmium (Cd), arsenic (As), zinc (Zn), nickel (Ni), antimony (Sb), germanium (Ge), aluminum (Al) and hexavalent chromium (Cr⁶⁺) from 69 home-cooking utensils into a food stimulants. The results of migration testing according to the Korea standards and specifications for utensils, containers and packages showed values the allowable migrantion limits. Al was detected in all 7 utensil materials with the average concentration ranging from 0.002-5.989 mg/L. According to the migration conditions for (180℃, 30 min), the average concentration of Al in paper was 7.2 times higher than 25℃, 10 min (P<0.05). The results of migration testing at 180℃, 30 min were also below the allowable migrantion limits. When comparing with the provisional tolerable weekly intake (PTWI) of Al, the estimated weekly intakes (EWI) accounted for 0.000-0.045% for Al.

• Korea Science and Art Forum
• /
• v.20
• /
• pp.147-158
• /
• 2015

This study made an approach to the industrial exhibition space, which is a medium of marketing communication, from the position of an enterprise and consumers through the output of Space Design, and conducted it with focus on B2B transactions among specialized exhibitions. In addition, this study inquired into what factors should be considered along with space design by interpreting the purpose of participating in the exhibition and space design of the enterprise which supply capital goods, elements, related technologies and materials, etc. This study aimed at drawing the direct/indirect effect, produced by space design, on the marketing by analyzing correlation between space design and participating enterprises' marketing. Despite the marketing effect of the exhibition, which was proved by preceding research results, the reality is that exhibition-participating expenses work as considerable burden on enterprises. Particularly, booth design, which is forming the most proportion among the participating expenses, was found to have insufficient influence on visitors due to the decline in its importance among diverse factors influencing visitor's decision to visit a booth. Regardless of the business category of participating enterprises in the exhibition, the standard of exhibits was ranked as the most important consideration factor in visiting a booth. Even by business category, the standard of booth design rarely had an influence on booth visit. Booth design had an affirmative influence on participating enterprise's preference, but its influence on product purchase or business talk & contact with a participating enterprise or price was found to be extremely low. It's difficult to judge marketing success or failure of an exhibition by the form and standard of booth design. Preferably, this study infers that it's necessary to put much weight on qualitative excellence of an exhibition, which consists of participation of an enterprise in possession of excellent technologies, exhibits with higher standards and high-quality visitors with purchasing power. This study suggests that it's more effective to set up the plan for expansion of participation in exhibition by optimally regulating the proportion of space design in participating expense to increase marketing effectiveness of an exhibition. The limitations of this study, analysis of which based on the visitors to an exhibition only, requires supplementation through the follow-up research work on participating enterprises in the exhibition.

• Economic and Environmental Geology
• /
• v.57 no.2
• /
• pp.205-217
• /
• 2024

This study evaluated the physical characteristics and quality of volcanic rocks distributed in the Jeju Island-Ulleung Island area as aggregate resources. The main rocks in the Jeju Island area include conglomerate, volcanic rock, and volcanic rock. Conglomerate is composed of yellow-red or gray heterogeneous sedimentary rock, conglomerate, and encapsulated conglomerate in a state between lavas. Volcanic rocks are classified according to their chemical composition into basalt, trachybasalt, basaltic trachytic andesite, trachytic andesite, and trachyte. By stratigraphy, from bottom to top, Seogwipo Formation, trachyte andesite, trachybasalt (I), basalt (I), trachybasalt (II), basalt (II), trachybasalt (III, IV), trachyte, trachybasalt (V, VI), basalt (III), and trachybasalt (VII, VIII). The bedrock of the Ulleung Island is composed of basalt, trachyte, trachytic basalt, and trachytic andesite, and some phonolite and tuffaceous clastic volcanic sedimentary rock. Aggregate quality evaluation factors of these rocks included soundness, resistance to abrasion, absorption rate, absolute dry density and alkali aggregate reactivity. Most volcanic rock quality results in the study area were found to satisfy aggregate quality standards, and differences in physical properties and quality were observed depending on the area. Resistance to abrasion and absolute dry density have similar distribution ranges, but Ulleung Island showed better soundness and Jeju Island showed better absorption rate. Overall, Jeju Island showed better quality as aggregate. In addition, the alkaline aggregate reactivity test results showed that harmless aggregates existed in both area, but Ulleungdo volcanic rock was found to be more advantageous than Jeju Island volcanic rock. Aggregate quality testing is typically performed simply for each gravel, but even similar rocks can vary depending on their geological origin and mineral composition. Therefore, when evaluating and analyzing aggregate resources, it will be possible to use them more efficiently if the petrological-mineralological research is performed together.

• Food Science and Preservation
• /
• v.30 no.1
• /
• pp.109-121
• /
• 2023

This study was conducted to evaluate vitamin D intake of Koreans in a total diet study (TDS) and to determine the effect of irradiation on vitamin D synthesis in mushrooms. For analysis, sample were saponified and extracted with hexane, and vitamin D was quantified by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Based on the validation results, the recovery of the National Institute of Standards and Technology (NIST) standard reference sample (SRM) 1849a was 96.7% and the z-score of -1.6 was obtained by the Food Analysis Performance Assessment Scheme (FAPAS) proficiency test (PT) 21115. Vitamin D₂ was not detected in any samples, and the highest level of vitamin D₃ was detected in mackerel and anchovies ranging from 24.2 to 120.2 ㎍/kg. The mean daily intake of vitamin D was 0.99 ㎍/day, as estimated from the vitamin D contents of the analyzed foods and their corresponding intake. The adequate intake (AI) of vitamin D based on the Dietary reference intakes for Koreans provided by the Ministry of Health and Welfare is 5-15 ㎍/day for Koreans aged 6 to 75 years. Compared with this AI, vitamin D intake of Koreans estimated in this study was inadequate. For that, the increased vitamin D content in ultraviolet (UV)/sun light irradiated mushrooms warrants further research to increase vitamin D intake of Koreans through diet.

• Economic and Environmental Geology
• /
• v.57 no.4
• /
• pp.397-416
• /
• 2024

This study assessed the hydrogeological properties of the deep geological environment to develop safety criteria for the natural barriers used in the deep geological disposal of high-level radioactive waste in Korea. The assessment focused on the distribution and trends of hydraulic conductivity and permeability properties appropriate for the domestic geological environment, using various in-situ hydraulic test data collected for groundwater development and management. To develop a depth-hydrogeological property relationship model suitable for domestic conditions, the study reviewed various international research examples and applied a representative model that explains the trends of hydraulic conductivity and permeability with depth. The development of the model suitable for Korea involved applying ensemble regression analysis to account for the uncertainty of various factors in the collected data. The results confirmed that existing international depth-hydrogeological property relationship models adequately describe the characteristics of the domestic geological environment. Considering the preferred hydrogeological criteria suggested by countries like Sweden, Germany, and Canada, there is a high likelihood that a suitable geological environment exists in Korea. Additionally, the application of hydrogeological criteria indicative of low-permeability environments showed that suitable conditions for disposal construction increase at depths greater than 300 m, where the influence of fractures on groundwater flow might be minimal at depths exceeding 500 m. This research can serve as foundational information for establishing hydrogeological safety standards for natural barriers in Korea according to international regulatory guidelines.

• Journal of Sinology and China Studies
• /
• v.81
• /
• pp.227-256
• /
• 2019

Hong Kong's protests, which began in June 2019 with Anti-Extradition Bill Protests, have already lasted for months, and the demonstrations have a significant impact on China and Hong Kong as a whole. The protests began in opposition to the Hong Kong government's revision of the extradition bill, but in substance, it has a strong nature as a test of China's "One Country Two Systems" policy. Since the establishment of the Hong Kong Special Administrative District on July 1, 1997, the primary legal norm between China and Hong Kong is the Basic Law of Hong Kong. However, conflicts of legal standards have occurred frequently due to the difference between socialism and the capitalist legal system, and there has been a continuous controversy over the interpretation of the Basic Law of Hong Kong. Moreover, the core of the legal conflict between China and Hong Kong has always been China's "One Country Two Systems" policy. This paper examined the issues related to the "Right of Legal Interpretation" of Standing Committee of the National People's Congress, the characteristics and interpretation rights of the Basic Law of Hong Kong, the direct election system of the administrative minister, the implementation of the universal suffrage, and the legislative issues of the application of Article 23 of the Hong Kong Basic Law. Furthermore, this paper also investigated the laws and systems newly introduced by China to solve these legal conflicts. The integration of the legal system of the divided state is a complicated process beyond the combination of the legal system by integrating the multiple legal systems that have separated for a long time under heterogeneous political, economic, and social networks. Moreover, the adjustment and integration of various legal systems under the premise of a single Constitution is the starting point for the actual inclusion of various fields after the unification as well as unification process and provides a basis for achieving full integration. Therefore, the unification of the divided countries should be the first step in a long journey toward becoming a practical one, not a goal itself. It is crucial to reduce trial and error and cost, and achieve stable unification in our unification process in Korea, by learning lessons from the contradictions and conflicts that appear in the "One Country Two Systems" unification between China and Hong Kong.