• Food Science and Preservation
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• v.16 no.3
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• pp.321-326
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• 2009

We assessed quality changes in and washing effects (time and method) on lettuce (Lactuca sativa L.) treated with micro-bubbles. Samples were treated with micro-bubbling for 1, 3, or 5 min, and the 5-min treatment yielded the best results in terms of reduced total microorganism counts, sensory aspects, and degree of washing. Total microorganism counts were 4.30 log colony-forming units (CFU)/g in unwashed lettuce(CT), 4.10 log CFU/g in hand-washed lettuce (HW), 3.98 log CFU/g in conventional, bubble-washed lettuce (BW) and 3.25 log CFU/g in micro-bubble-washed lettuce (MW). In comparison, total counts of samples examined after 10 days of storage were 7.00 log CFU/g for CT, 6.19 log CFU/g for HW, 6.02 log CFU/g for BW, and 5.89 log CFU/g for MW. The lowest counts were seen after micro-bubble treatment. BW and MW samples showed significantly higher counts than did CT and HW samples. In general, BW and MW samples did not vary significantly in count numbers. MW showed a 2.3-fold lower residual pesticide level compared with CT, and also had the lowest level of impurities. HW and BW samples were not well washed.

• Journal of Food Hygiene and Safety
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• v.35 no.1
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• pp.60-67
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• 2020

This study determined the microbial contamination levels of hot pepper at harvest, sorting, and distribution stages to suggest a way of reducing the microbial contamination of hot peppers by changing work gloves used throughout these processes. According to the monitoring results, the contamination levels of total aerobic bacteria (TAB) were found in the following order: soil (5.3±0.9 log CFU/g), hot pepper (4.2±0.9 log CFU/g), gloves (4.2±0.6 log CFU/g), baskets (4.1±0.7 log CFU/ g), clippers (3.9±0.6 log CFU/ g) and water (3.2±1.1 log CFU/g) at harvest stage. The contamination level of coliforms were found in the following order: soil (2.2±0.9 log CFU/g), hot pepper (2.2±0.3 log CFU/g), gloves (2.1±0.6 log CFU/g), clippers (2.0±0.21 log CFU/ g) and baskets (1.9±1.1 log CFU/ g) at harvest stage. TAB on hot pepper at the harvest stage was reduced from 4.2±0.9 log CFU/g to cold storage 3.8±0.2 log CFU/g and room temperature storage 2.6±0.3 log CFU/g, respectively. By the replacement of work gloves and lower distribution temperature, TAB levels of the peppers were significantly reduced compared to those without replacement and distributed at room temperature. In addition, the utilization of plasma was effective on reducing microbial contamination of hot pepper. These results demonstrated that appropriate replacement of gloves at the harvest stages, using plasma in the distribution stage, and refrigerated distribution conditions, which are simple and easy to practice in the field, are effective to reduce microbial contamination on hot peppers.

• Journal of the Korean GEO-environmental Society
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• v.3 no.3
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• pp.15-25
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• 2002

The permeability coefficient is one of the fundamental engineering properties of soft clays. Consolidation process as well as migration of pollutants in soil are affected the permeability coefficient, which generally decreases with the reduction in void ratio during consolidation. After Kozeny(1927) and Carman(1956), many researchers have proposed the relationships between void ratio and permeability in such forms as; (1) log e - log k(1+e), (2) e - log k, or (3) log e - log k. Constant rate of strain (CRS) tests was performed with undisturbed samples obtained at Kunsan and Kimhae deposits, which are representative Korean marine clay. From the results of the tests, the relationships were found valid for Kunsan and Kimhae clays. The experimental correlation $C_k=0.5e_o$ was satisfied with Kimhae clay but not with Kunsan clay.

• Journal of the Korean Wood Science and Technology
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• v.41 no.4
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• pp.337-345
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• 2013

Log grading rules are essential tools to ensure the quality of logs in distribution structure. The rules should reflect the long experience and accepted usage practice in the market. A gap between the rules and market should be improved based on analysis of log qualities that produced and market demand. In this study more than ten millions logs which were produced by 5 Regional Forest Services in 2010~2011 period, were analyzed in their qualities including diameters and lengths by species. A proposal was driven to improve the current log grading rules in terms of log diameter classes and length. The followings are the summary of this study. Most of domestic softwood logs are belong to small diameter class of 100~160 mm, which imply the diameter classes of current log grading rules are immoderate. Distributions of log diameter shows distinctive patterns by species, which indicate a necessity of differentiated diameter classes by species in an improved rules. Lengths of logs in productions do not corresponding to the demands and preferences in sawmills. Therefore it is highly recommended to include log length term in an improved log grading system. Based on these findings, 6 log grading systems for 3 species groups of softwood are newly proposed to improve current log grading rules. Limits of log diameter and log length are also proposed for each log grading system.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.10
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• pp.1619-1626
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• 2014

This study was conducted to evaluate the effects of Joule heating and hydrostatic pressure on reduction of total aerobes and spores of Bacillus cereus in four kinds of sauces prepared with traditional Korean fermented foods. Total aerobes and inoculated spores of B. cereus in sauces were assayed after treatment or during storage at $30^{\circ}C$ after 4 or 8 weeks. Joule heating ($85^{\circ}C$), hydrostatic pressure (550 Mpa, 5 min), and antimicrobial additive (3% ethanol) were separately applied or combined as a hurdle technique. A 1.0~2.0 log reduction in total aerobes of Doenjang and Gochujang sauce was observed upon Joule heating at 80, 85, and $95^{\circ}C$. Significant reductions (0.92~1.21 log/0.5~1.38 log and 1.26~1.7 log/0.47~3.45 log) of total aerobes/spores of B. cereus in Doenjang and Gochujang sauce, respectively, occurred upon JA (Joule+additive), JP (Joule+hydrostatic pressure) or JAP (Joule+additive+ hydrostatic pressure). Effects of each treatments were maintained or increased during storage for 8 weeks at $30^{\circ}C$, suggesting that total aerobes and spores of B. cereus in Doenjang and Gochujang sauce can be controlled through Joule heating or hydrostatic pressure treatment.

• Journal of the Korean Chemical Society
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• v.36 no.6
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• pp.840-848
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• 1992

An ionizable macrocyclic ligand, diaza-18-crown-6-diisopropionic acid(K22DAP) has been synthesized. Protonation constants of this compound and stability constants with some lanthanides were determined by potentiometric titration method. The protonation constants are log$K_1$ = 9.05, log$K_2$ = 8.37, log$K_3$ = 1.88 and log$K_4$ = 0.99. The logarithmic values of stability constants with La(III), Nd(III), Gd(III) and Lu(III) are 11.14, 11.43, 11.74 and 10.88 respectively. Extraction behavior of Ln(III) ion was investigated using TTA(thenoyltrifluoroacetone) as extractant in the presence of K22DAP as macrocyclic ionophore. It was observed that Ln(K22DAP)TTA is the dominating species in aqueous complexes of La(III) and Nd(III).

• Journal of Food Hygiene and Safety
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• v.28 no.4
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• pp.319-323
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• 2013

The objective of this study was to investigate the microbial contamination levels of ginseng and ginseng products distributed in markets. A total of 81 ginseng and ginseng products samples (fresh ginseng 37, white ginseng 15, red ginseng 15, red ginseng beverage 14) were tested to analyze sanitary indicator bacteria (total aerobic bacteria, coliforms and Escherichia coli), major foodborne pathogens, and fungi. The contamination levels of total aerobic bacteria and coliforms were in the range of 3.19 to 7.02 log CFU/g for fresh ginseng, 0.25 to 7.31 log CFU/g for white ginseng, 0 to 2.89 log CFU/g for red ginseng and 0 to 1.70 log CFU/mL for red ginseng beverage. In case of major foodborne pathogens, B. cereus was detected at levels of 0.50 to 2.41 log CFU/g in samples except red ginseng beverage. Fungi was detected at levels of 2.41 log CFU/g in fresh ginseng, the contamination levels of the other ginseng products samples were lower than 1 log CFU/g or mL. These results indicate that the ginseng and ginseng products were comparatively safe with respect to microbiological hazard.

• Journal of the Korean Society of Food Science and Nutrition
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• v.38 no.2
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• pp.252-260
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• 2009

Whereas the numbers of childcare centers and kindergartens are increasing rapidly, systematic management to control the food safety of foodservice operation is not yet well established. Samples from 12 centers in Seoul and Gyeonggi Province were collected to assess the microbiological quality of 32 raw materials, 24 cooked foods, 76 food-contact surfaces (knives, cutting boards, dish towels and gloves), 17 employees' hands and 12 air-borne bacteria. The microbiological analyses were performed for aerobic plate counts (APC), Enterobacteriaceae, E. coli and 7 pathogens (B. cereus, C. jejuni, C. perfringens, L. monocytogenes, Salmonella spp., S. aureus, and V. parahaemolyticus). Among raw materials, E. coli ($1.39{\sim}2.08\;\log\;CFU/g$) were detected in 4 out of 6 meats and 7.46 log CFU/g of APC in tofu. High enterobacteriaceae levels of 4.23, 5.14 and 4.19 log CFU/g were found in cucumber salad, steamed spinach with seasonings and steamed bean sprout with seasonings, respectively. No pathogens were found in all samples except for C. perfringens detected from raw spinach and raw lotus root. Only APC and enterobacteriaceae were found in food-contact surfaces. Two of the 23 knives and three of the 24 kitchen boards showed over 500 CFU/$100\;cm^2$ of APC; also, APC levels (5.03 to 5.44 log CFU/g) were detected in 4 of the 12 dish towels. Only one glove showed Enterobacteriaceae (2.44 log CFU/glove) contamination. Enterobacteriaceae were found in 2 employees' hands ($2.37{\sim}4.44\;\log\;CFU$/hand) among the 16 employees. The contamination levels of air-borne bacteria were shown unacceptable in two (2.25 and 2.30 log CFU/petri-film/15 min) out of the 12 kitchen areas. These results suggest that the microbiological hazards in some foods and environments are not well controlled and thus a guideline should be provided to ensure the food safety in childcare center and kindergarten foodservice operations.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.9 no.8
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• pp.3182-3202
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• 2015

Flexibly expanding the storage capacity required to process a large amount of rapidly increasing unstructured log data is difficult in a conventional computing environment. In addition, implementing a log processing system providing features that categorize and analyze unstructured log data is extremely difficult. To overcome such limitations, we propose and design a MongoDB-based unstructured log processing system (MdbULPS) for collecting, categorizing, and analyzing log data generated from banks. The proposed system includes a Hadoop-based analysis module for reliable parallel-distributed processing of massive log data. Furthermore, because the Hadoop distributed file system (HDFS) stores data by generating replicas of collected log data in block units, the proposed system offers automatic system recovery against system failures and data loss. Finally, by establishing a distributed database using the NoSQL-based MongoDB, the proposed system provides methods of effectively processing unstructured log data. To evaluate the proposed system, we conducted three different performance tests on a local test bed including twelve nodes: comparing our system with a MySQL-based approach, comparing it with an Hbase-based approach, and changing the chunk size option. From the experiments, we found that our system showed better performance in processing unstructured log data.

• Journal of the Chungcheong Mathematical Society
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• v.26 no.4
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• pp.769-780
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• 2013

Motivated essentially by their potential for applications in a wide range of mathematical and physical problems, the log-sine and log-cosine integrals have been evaluated, in the existing literature on the subject, in many different ways. Very recently, Choi [6] presented explicit evaluations of some families of log-sine and log-cosine integrals by making use of the familiar Beta function. In the present sequel to the investigation [6], we evaluate the log-sine and log-cosine integrals involved in more complicated integrands than those in [6], by also using the Beta function.