• Korean Journal of Microbiology
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• v.52 no.4
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• pp.391-397
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• 2016

Clostridium is a genus of Gram-positive, rod shape, spore-forming obligate anaerobe. Recently, Clostridium has been attracted as a host for bio-based chemical production, due to its diversity of substrate utilization and the production ability for metabolites which can be used as a building block for chemical production. Especially, butanol produced from Clostridium has been considered as an alternative fuel. As a transportation fuel, butanol has a higher energy density and lower hygroscopicity compared to ethanol, the first generation biofuel. Recently, metabolic engineering of Clostridium has been massively conducted for butanol production. In this study, the metabolic engineering strategy of Clostridium for butanol production has been reviewed with a brief perspective.

• Journal of The Korean Association For Science Education
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• v.35 no.4
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• pp.565-572
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• 2015

The purpose of this paper is to offer an analysis on the research trends of web-based inquiry learning effectiveness in science education, and to present suggestions for future studies. This study compiled data on 43 articles in Korea and international journals. The content analysis of articles published were from academic journals related to science education and educational technology from 2000 to 2014. The results are as follows: Among domestic articles, the participants ranged from school children to high school students. On the contrary, among foreign articles, the participants are centralized on secondary school students; most used experimental studies; most of the studies resulted with web-based inquiry learning in science education showing effectiveness on science learning performance or science inquiry ability; all web-based inquiry learning were designed using different models of teaching and learning, with the result in the case of domestic research, the utilized models refer to the STS learning model, Internet utilization problem-center inquiry learning model, Procedural model, while in the case of overseas research, the utilized models are SCY, IBLE, and TESI model. Implications of the findings are then discussed, which implies considerations for further research related to web-based inquiry learning.

• Journal of the Korean Wood Science and Technology
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• v.48 no.4
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• pp.431-449
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• 2020

Structural property of most hydrogels is soft, resulting in low mechanical performance that limits their usage in the biomedical applications. For overcoming the drawback, cellulose nanocrystals (CNCs) were adopted in this study. Effects of CNCs on characteristics and drug delivery performance of poly (vinyl alcohol) based hydrogels were explored. FT-IR results showed that the fabricated hydrogels had semi-IPN (semi-interpenetrating polymer network) by formation of acetal and aldehyde bridge. Water absorption and swelling ratio decreased with increasing CNCs content, and the hydrogels with CNCs showed better viscoelastic performance than the without CNCs. Also, CNCs mostly improved the ability of the hydrogel to absorb the drug and the sustainability of the drug release. These results demonstrated that incorporating CNCs into the hydrogel systems can be a good alternative to improve drug delivery performance and mechanical property of the hydrogels.

• Biomedical Science Letters
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• v.5 no.2
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• pp.201-208
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• 1999

To evaluate an effect of growth periods on the bromobenzene-induced liver damage, bromobenzene was administrated to 5-week-old rats and 10-week-old rats pretreated with bromobenzene 5 times every other day for 10 days and then the animals were sacrificed. The results were obtained as follows; The increasing rate of serum levels of alanine aminotransferase, xanthine oxidase activity, hepatic lipid peroxide contents, liver weight per body weight (％) and decreasing rate of hepatic contents of protein to each control group were higher in 10-week-old rats than 5-week-old rats by the pretreatment of bromobenzene. According to the above results, 10-week-old rats indicated more severe liver injury than 5-week-old those in case of bromobenzene pretreatment. On the other hand, hepatic aniline hydroxylase activity was more increased in 10-week-old rats than 5-week-old rats both in control and bromobnezene pretreated rats where as the reverse in hepatic glutathione S-transferase. In case of hepatic GSH determination at the intervals of 2, 4, 8, 24 hours throughout 24 hr after administration of single dose of bromobenzene to 5-week-old and 10-week-old rats both in control and bromobnezene pretreated, the rate of GSH utilization was lower in 10-week-old rats than 5-week-old rats. In conclusion, from the above experimental, it is deduce that the 10-week-old rats showed more severe liver injury than 5-week-old rats by the bromobenzene treatment because the disposal ability of bromobenzene in liver was lower in 10-week-old rats than 5-week-old rats.

• Korean Journal of Community Nutrition
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• v.24 no.6
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• pp.525-534
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• 2019

Objectives: Reduced glucose utilization in the main parts of the brain involved in memory is a major cause of Alzheimer's disease, in which ketone bodies are used as the only and effective alternative energy source of glucose. This study examined the effects of a low-carbohydrate and high-fat (LCHF) diet supplemented with a ketogenic nutrition drink on cognitive function and physical activity in the elderly at high risk for dementia. Methods: The participants of this study were 28 healthy elderly aged 60-91 years showing a high risk factor of dementia or whose Korean Mini-Mental State Examination (K-MMSE) score was less than 24 points. Over 3 weeks, the case group was given an LCHF diet with nutrition drinks consisting of a ketone/non-ketone ratio of 1.73:1, whereas the control group consumed well-balanced nutrition drinks while maintaining a normal diet. After 3 weeks, K-MMSE, body composition, urine ketone bodies, and physical ability were all evaluated. Results: Urine ketone bodies of all case group subjects were positive, and K-MMSE score was significantly elevated in the case group only (p=0.021). Weight and BMI were elevated in the control group only (p<0.05). Grip strength was elevated in all subjects (p<0.01), and measurements of gait speed and one leg balance were improved only in the case group (p<0.05). Conclusions: We suggest that adherence to the LCHF diet supplemented with a ketogenic drink could possibly influence cognitive and physical function in the elderly with a high risk factor for dementia. Further, we confirmed the applicability of this dietary intervention in the elderly based on its lack of any side effects or changes in nutritional status.

• Science of Emotion and Sensibility
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• v.15 no.1
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• pp.121-132
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• 2012

Recently, interest in emotional technology has escalated and its application has extended to many fields, from both an industrial (product) and service (culture, tourism, medical, education, advertising) perspective. Moreover, culture has become a fundamental aspect of modern industry, playing key roles in: gaming, exhibitions, performances, sports, tourism, design, edutainment, as well as various content distribution industries. The prospect of applying emotional technology for cultural content industries makes up for more than half of the 'plan-manufacture-distribution-marketing' process, and thereby also serves as driving force for the growth of a nation. The primary objective of the following research is analyze successful cases from the past through utilization of emotional technology, and to speculate on efficient directions for future research into developing emotional contents. To achieve this, some of the key terms have been defined and elaborated for the sake of clarity. The terms are as follows: emotion, emotion engineering, science of emotion, emotional technology, and emotional contents. Furthermore, studies were conducted based on the six different fields surrounding CT R&D to observe how projects involving emotional technology have succeeded both on a national and global scale. Based on this analysis, this research aims to develop personalized 'Concierge' service-providing contents, contents designed to maximize performance ability of humans, and contents that could be controlled simply via emotion to effectively spread the culture of Korea by focussing on 'fusion' content development. The following research data may hopefully serve as a basic reference to industries navigating towards emotional content development.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.567-575
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• 1999

This study found potential ability to generate electric power using difference in water temperature between sea surface water and deep water in the East Sea which includes the East Sea Proper Water with the temperature less than 1$^{\circ}C$ throughout a year without seasonal variation. To quantify the difference in water temperature between sea surface water and deep water in the East Sea. We computed the annual mean ($^{\circ}C$), the annual amplitude ($^{\circ}C$), the annual phase (degree) and the duration time which showed more than 15$^{\circ}C$ temperature difference from the water temperature data using Harmonic analysis during 1961~1997. The best place for generating electric power in the East Sea seems to be the eastward ocean areas (36$^{\circ}$ 05'N, 129$^{\circ}$ 48'E~36$^{\circ}$ 05'N, 130$^{\circ}$ 00E'E) from Pohang city. The annual mean of the difference in water temperature between sea surface water and 500 m depth was 24$^{\circ}$C at the place to generate electric power in August according to the data of 1961~1997. the maximum duration periods with more than 15$^{\circ}C$ temperature difference were 215 days (5/5-12/10) a year in the place mentioned electricity with a stable plan. In the East Sea coastal areas of the Korean peninsula, the average minimum depth to reach the East Sea Proper Water from surface water is 300 m and fluctuates between 250 m and 350 m throughout a year. Further studies could be needed for the utilization of cold water, such as the East Sea Proper Water for energy conversion.

• Journal of Korea Water Resources Association
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• v.41 no.10
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• pp.983-993
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• 2008

In recent times, sea level increasing caused by abnormal weather and global warming, sea-sand dredging and complex development causes various kind of erosion damages onto the coastal area in the world. The various types of erosion control and protection methods are applied but there are no signs of fruitful effectiveness. The PC concrete protection block for shore protection structure is practically installed in globally but most of structures in the present day became villainous because of bad accessability. In this study, hydrophilic revetments for control and protection of coastline erosion will be developed in order to make up for a faculty of the shore erosion protection block with better accessibility and excellent protection ability. Experimental measurements were researched to insure for the capacity and facility on reflection coefficient, overtopping volume, and overtopping height characteristics of newly developed shore erosion protection block in model tests. As the result, hydraulic model tests show much excellent than the general step block. Field tests were carried out also to verify through vegetative test on an affinity and construction work test of control-protection on coastline erosion with actual utilization. In the latter case, deposition of sand accumulation occurred in fairly short time at the established reaches and then we can be confirmed to utilize for newly developed block as the revetments for control and protection of coastline erosion.

• Korean Journal of Soil Science and Fertilizer
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• v.35 no.1
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• pp.59-67
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• 2002

A phosphate solubilizing bacterium. strain 60-2G, possessing a strong ability to solubilize insoluble phosphate was isolated from the rhizosphere of grass. On the basis of GC-FAME profile, carbon utilization pattern, and the DNA sequence of a conserved partial 16S rRNA gene, the 60-2G was identified as Enterobacter intermedium. The analysis by HPLC revealed that the strain 60-2G produced mainly gluconic and 2-ketogluconic acids with small amounts of lactic acid in broth culture medium containing hydroxyapatite. During the incubation period of the strain 60-2G in broth culture, pH of the medium decreased upto 3.8 while the soluble phosphate concentration increased. The reversed correlation between pH and soluble phosphate concentration indicated that the solubility of P was due to the produced organic acids. The sequence homology of the deduced amino acids suggested that E. intermedium 60-2G synthesized PQQ which is essential for the oxidation of glucose by glucose dehydrogenase.

• Korean Journal of Remote Sensing
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• v.37 no.6_2
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• pp.1803-1818
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• 2021

As the frequency of drought increases due to climate change, it is very important to have a monitoring system that can accurately determine the situation of widespread drought. However, while ground-based meteorological data has limitations in identifying all the complex droughts in Korea, satellite remote sensing data can be effectively used to identify the spatial characteristics of drought in a wide range of regions and to detect drought. This study attempted to analyze the possibility of using remote sensing data for drought identification in South Korea. In order to monitor various aspects of drought, remote sensing and ground observation data of precipitation and potential evapotranspiration, which are major variables affecting drought, were collected. The evaluation of the applicability of remote sensing data was conducted focusing on the comparison with the observation data. First, to evaluate the applicability and accuracy of remote sensing data, the correlations with observation data were analyzed, and drought indices of various aspects were calculated using precipitation and potential evapotranspiration for meteorological drought monitoring. Then, to evaluate the drought monitoring ability of remote sensing data, the drought reproducibility of the past was confirmed using the drought index. Finally, a high-resolution drought map using remote sensing data was prepared to evaluate the possibility of using remote sensing data for actual drought in South Korea. Through the application of remote sensing data, it was judged that it would be possible to identify and understand various drought conditions occurring in all regions of South Korea, including unmeasured watersheds in the future.