• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.72-77
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• 2014

Microstructure and thermal stability of mechanically ball milled $FeS_2$ were investigated. The average particle size and distribution of $FeS_2$ powder were changed in two steps with the increased ball milling time. The average particle size drastically decreased from $98.4{\mu}m$ to 1.01 and $0.89{\mu}m$ after ball milling of 10 h and 30 h, respectively. However, the distribution was broad and a shoulder appeared at $2{\mu}m$ because the pulverization was still in process at 10 h ball milling. After 60 h ball milling, the distribution became narrower. After ball milling of 120 h, the average particle size increased because of $FeS_2$ particle agglomeration. Therefore, the particle size distribution became broaden again. Finally, after ball milling of 170 h, $FeS_2$ with the narrowest size distribution can be obtained. Thermal stability of $FeS_2$ was unstable as the $FeS_2$ particle was pulverized. Therefore, the activation energy of the fine size particles is 27% lower than that of the as-received $FeS_2$.

• Korean Journal of Food Science and Technology
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• v.23 no.3
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• pp.379-387
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• 1991

The effects of organic acids (acetic, citric and lactic acids) treatment on microbial spoilage of chilled beef were studied during aerobic storage at $4^{\circ}C$ for 11 days. The organic acids had definite effects on the delay of the development of off-odor and slime of chilled beef. When chilled beef slices were treated with 1, 2, 3 and 4% of organic acids, off-odor was developed 1, 2, 3 and 5 days later than control, respectively, regardless of the kinds of organic acid. The slime was produced two days after the day of off-odor development in $1{\sim}3%$ organic acid-treated chilled beef, but no slime was produced on chilled beef treated with 4% organic acid. The off-odor was detected organoleptically when pH and number of microorganisms of chilled beef were, $5.6{\sim}5.8\;and\;0.8{\times}10^7{\sim}1.8{\times}10^7\;cell/cm^2$, respectively, and slime was observed when pH and number of microorganisms of chilled beef were $5.9{\sim}6.2\;and\;2.0{\times}10^7{\sim}6.0{\times}10^7\;cell/cm^2$, respectively, in control and treated groups.

• Korean Journal of Social Welfare Studies
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• no.39
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• pp.365-393
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• 2008

This research examnied the roles, the strategies and the influence of labor unions on the pension reform. In Italia labor unions were important actors in pension reform politics during 1990s, but in 2004 labor union was excluded from the pension reform. This difference is not only related with diffusion of the leftist party but also the experience of pension benefit retrenchment of the pension reform in 1995 in which labor unions had initiatives. Labor unions choose their strategies, social dialogue or mass struggle, depending on the attitudes of government. After change of government following the failure of the pension reform in 1994 Italian government tried social dialogue. In Dini reform in 1995, laborunions had initiative in making pension reform plan. Labor unions obtained member's approval using membership vote. It had repressed opposition from militant sectors effectively. However Labor unions concentrated on the issues of transition measures and protecting vested rights in seniority pension ignoring problems of contribution evasion of small-firm workers and benefit adequacy of young workers. Even when labor unions leaded social concertation processes and pursued union democracy, labor unions' influences on the pension reform had fundamental limitations.

• Korean Journal of Clinical Laboratory Science
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• v.51 no.2
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• pp.171-176
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• 2019

A comparative study between commercially available mycobacteria growth indicator tubes (MGIT) in the BACTEC MGIT 960 System and the conventional Ogawa media was carried out to assess the effectiveness of the re-decontaminating process for the recovery of mycobacteria. Processed specimens with 5% sodium hydroxide and 0.5% N-acetyl-L-cysteine were inoculated into MGIT and Ogawa media. The acid fast bacilli (AFB) recovered from the cultures were identified using a mycobacterium tuberculosis (TB) antigen kit. If contaminants were observed in the MGIT tubes within five days, a decontaminating process was repeated. A total of 1,190 out of 4,790 (24.8%) specimens showed positive results using the BACTEC MGIT 960 system. Among them, 278 specimens were reprocessed. When the MGIT and Ogawa results were compared, it showed discordant results (weighted kappa value: 0.283). One TB and 10 nontuberculous mycobacteria (NTM) were newly detected in MGIT only. The likely benefit of the re-decontaminating process is the detection of additional mycobacteria that could not be detected without a re-decontaminating process despite being small in number. In addition to the combination of MGIT and Ogawa, the re-decontaminating process is recommended in the case of contaminations to recover mycobacteria.

• The Journal of the Korea Contents Association
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• v.21 no.6
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• pp.404-414
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• 2021

This study was to investigate the differences of functional health status and medical service experience and needs between general and vulnerable older people in community. This study is a cross-sectional descriptive research. The data obtained through direct visit surveys from November to December 2016. The target population of the study was older people over 65 years old, the final study subjects were 444 older people residing in one district of Seoul. The chi-square test was conducted to confirm the difference in their functional health areas and medical service experiences, and the necessity of medical service utilization in accordance to the social class. In the experience of abnormality in functional health, the vulnerable older people had higher experience in cognitive function, nutrition, hydration, pain, and falling than the general older people. The rate of experience of using medical service to solve the cognitive function problem for general older people was 31.9%, higher than that of the vulnerable older people. In contrast, the medical service utilization needs of the vulnerable older people in the pain management category was significantly higher than that of the general older people. In setting policy of public medical service programs for general and vulnerable older people in community may be differentially developed based on this study. In order to improve the medical accessibility of the vulnerable older people, public medical institutions should be actively supported to overcome obstacles to medical use due to economic barriers.

• The Journal of Internal Korean Medicine
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• v.42 no.6
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• pp.1199-1210
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• 2021

Objectives: The aim of this study was to analyze the correlation between patterns determined by pattern identification of functional dyspepsia (FD) and tongue features, including tongue coating and tooth marks, in FD patients. Methods: We reviewed the clinical records of 68 FD patients who visited the Department of Digestive Diseases of Kyung Hee University Korean Medicine Hospital from September 1, 2020 to August 31, 2021. The subjects were evaluated with a computerized tongue image acquisition system (CTIS) and by pattern identification of FD. Measurement included the percentage of tongue coating, tooth mark levels, and pattern scores. Results: Statistically significant negative correlations were noted between the scores of the pattern of 'spleen and stomach deficiency and cold' (SSDC) and the percentage of tongue coating in whole, center, and root of the tongue body. However, no other patterns were correlated with any parameter measured by CTIS. No significant difference was noted in the percentage of tongue coating and the tooth mark level between the patterns. Conclusions: This study demonstrated that the pattern of SSDC was significantly associated with the percentage of tongue coating. We suggest that the percentage of tongue coating could be a useful indicator for identifying the degree of patterning of SSDC in patients with FD.

• Journal of Life Science
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• v.33 no.8
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• pp.680-691
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• 2023

Peak oil, climate change, and microplastics caused by the production and usage of petroleum-based plastics have threatened the sustainability of our daily life, and this has emerged as a recent global issue. To solve this global issue, the production and usage of biodegradable eco-friendly bioplastics such as polyhydroxyalkanoates (PHAs) has been suggested as an alternative. Therefore, in this review, the present status of global PHA manufacturers, the advantages of the production of PHAs using marine-origin microorganisms (with their productivity potential) and further required research and development strategies for cost-competitive production of PHAs using marine-based microorganisms were investigated. In this review, PHAs produced from marine microorganisms were found to have similar physical properties to petroleum-based plastics but with several advantages that can reduce the costs of PHA production. Those advantages include, seawater used in the medium preparation step, and osmotic-based cell lysis technology used in the separation and purification steps. However, the PHA productivities from marine microorganisms showed somewhat lower efficiencies than those from the commercial strains isolated from terrestrial environments. In order to solve the problem, further research strategies using synthetic microbiology-based technology, the development of long-term continuous culture technology, and solutions to improve PHA efficiency are required to meet future market demands for alternative bioplastics.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3A
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• pp.341-347
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• 2008

Among coating systems used for steel bridge coatings on highway such as red lead-pigmented alkyd, chlorinated rubber, waterborne inorganic zinc, inorganic zinc/epoxy/urethane and inorganic zinc/epoxy/fluororesin, evaluation of deterioration degree and prediction of lifetime through regression analysis were carried out for coating systems widely used and grossly degraded. For evaluation of deterioration degree, 75 bridges on highway were selected, and evaluations were carried out according to point offering method regulated by Guideline of maintenance coating for steel bridges used in Korea Expressway Corporation. Lifetime prediction results showed 13.0~13.3 years for the whole nation, 11.8 years for urban and industrial region in the metropolitan area, 13.2 years for rural region except the metropolitan area, 13.5~13.7 years for chlorinated rubber coating systems, and 12.86 years for red lead-pigmented alkyd systems. For prediction of the rest life of coating, we tried to execute parallel translations of standard deterioration curve to current life and deterioration degree for both x and y axes, and it was thought that parallel translation for x axis corresponded to deterioration aspects in actual environment. Maximum and minimum equations were derived from standard deterioration equation by adding and subtracting error values deduced in regression analysis to/from each coefficient in order to establish maintenance coating criteria for overall steel bridges on highway. Whole domain was divided into 8 parts in order to predict the rest life of coating and optimum time of maintenance coating, and maintenance coating criteria for each 8 domains were presented.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.611-626
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• 2023

Overseas examples of the characterization stage of site selection proposed by the International Atomic Energy Agency were reviewed to highlight the factors necessary for consideration in the deep disposal of high-level radioactive waste. Studies in Sweden, Finland, the USA, and Canada were considered. Site investigations in Sweden and Finland commonly covered the fields of geology, hydrogeology, and hydrogeochemistry using similar field investigation techniques. The USA considered survey groups and factors under pre- and post-lockdown guidelines, as well as those for desaturated and saturated surveys. involving geophysical, hydrological, hydrogeological, hydrogeochemical, mechanical/physical, and thermal-characterization investigations. Canada provided a list of investigative methods for both preliminary and detailed site assessments including geological, physical, boring, hydrological, laboratory testing, and chemical analysis studies. Results of this study should elucidate site-selection investigation factors and survey methods applicable to Korea.

• The Journal of Internal Korean Medicine
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• v.45 no.3
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• pp.519-531
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• 2024

Objectives: This case study reports the effectiveness of Korean medical treatment in a patient with cyclic vomiting syndrome. Methods: A 29-year-old female Korean patient with cyclic vomiting syndrome received acupuncture, electroacupuncture, herbal medicine, and moxibustion for 2 weeks in hospital. Changes in symptoms were evaluated using the Gastrointestinal Symptom Rating Scale (GSRS), Visual Analog Scale (VAS), Index for Nausea, Vomiting, and Retching (INVR), Nausea Severity Scale (NSS), Nepean Dyspepsia Index-Korean version (NDI-K), quality of life using the Functional Dyspepsia Related Quality of Life questionnaire (FD-QoL), and gastric motility using electrogastrography (EGG). Results: Post-treatment, the patient showed high satisfaction and improvement in symptoms of nausea and vomiting. The following changes were observed in scores: GSRS: 23 to 19; VAS of nausea: 88 to 95; VAS of dyspepsia: 95 to 12; INVR: 13 to 1; NSS: 17 to 5; NDI-K: 107 to 78; and FD-QoL 84 to 27. We also found positive results in Channel 3 of EGG parameters, implying the improvement of gastric motility disorder. Conclusion: Korean medical treatment can be a therapeutic option for cyclic vomiting syndrome.