• Korean Chemical Engineering Research
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• v.57 no.6
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• pp.868-873
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• 2019

In this study, the evaluation of performance of AORFB using methyl viologen and TEMPOL as organic active materials in neutral supporting electrolyte (NaCl) with various membrane types was performed. Using methyl viologen and TEMPOL as active materials in neutral electrolyte solution, the cell voltage is 1.37V which is relatively high value for AORFB. Two types of membranes were examined for performance comparison. First, when using Nafion 117 membrane which is commercial cation exchange membrane, only the charge process occurred in the first cycle and the single cell couldn't work because of its high resistance. However, when using Fumasep anion exchange membrane (FAA-3-50) instead of Nafion 117 membrane, the result was obtained as the totally different charge-discharge graphs. When current density was $40mA{\cdot}cm^{-2}$ and cut off voltage range was from 0.55 V to 1.7 V, the charge efficiency (CE) was 97% and voltage efficiency (VE) was 78%. In addition, the discharge capacity was $1.44Ah{\cdot}L^{-1}$ which was 54% of theoretical capacity ($2.68Ah{\cdot}L^{-1}$) at $10^{th}$ cycle and the capacity loss rate was $0.0015Ah{\cdot}L^{-1}$ per cycle during 50 cycles. Through cyclic voltammetry test, it seems that this difference in the performance between the full cell using Nafion 117 membrane and Fumasep anion exchange membrane came from increasing resistance due to chemical reaction between membrane and active material, not the capacity loss due to cross-over of active material through membrane.

• The Korean Journal of Archival Studies
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• no.16
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• pp.201-256
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• 2007

Nowadays Korean main archives and manuscript repositories are planning to develop archival information service for students and teachers in their web sites. This study is aimed at discovering main issues of developing archival information service for students and teachers and finding a solution. The goal of archival information service for students and teachers is the promotion of use through launching service and the gradual growth of archival management program. The customer group is segmented into the students and teachers who are learning and teaching Korean history in classroom. As a result of analyzing curriculum and educational environment, the archival information must be developed into teaching-learning materials. And the processing archival information into archival content is needed. Consequently the character of archival information service for students and teachers is conceptualized as archival content service for teaching-learning materials. At every step of developing archival content service for teaching-learning materials, the next main points are considered and achieved. First, the strategy of customer-focused service must be the same from beginning to end. Second, the growth of traditional archival management(e.g. classification, description and finding aids) must be contributed. Third, the collaboration system leading by professional education staff must be organized. Fourth, the archival information must be related with teaching-learning activities. Fifth, the quality of content is more important than the quantity of it. Sixth, the networking with another agencies for cooperation must be considered.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1108-1119
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• 2018

As the interest on the air pollution is gradually rising at home and abroad, automotive and fuel researchers have been studied on the exhaust and greenhouse gas emission reduction from vehicles through a lot of approaches, which consist of new engine design, innovative after-treatment systems, using clean (eco-friendly alternative) fuels and fuel quality improvement. This research has brought forward two main issues : exhaust emissions (regulated and non-regulated emissions, PM particle matter) and greenhouse gases of vehicle. Exhaust emissions and greenhouse gases of automotive had many problem such as the cause of ambient pollution, health effects. In order to reduce these emissions, many countries are regulating new exhaust gas test modes. Worldwide harmonized light-duty vehicle test procedure (WLTP) for emission certification has been developed in WP.29 forum in UNECE since 2007. This test procedure was applied to domestic light duty diesel vehicles at the same time as Europe. The air pollutant emissions from light-duty vehicles are regulated by the weight per distance, which the driving cycles can affect the results. Exhaust emissions of vehicle varies substantially based on climate conditions, and driving habits. Extreme outside temperatures tend to increasing the emissions, because more fuel must be used to heat or cool the cabin. Also, high driving speeds increases the emissions because of the energy required to overcome increased drag. Compared with gradual vehicle acceleration, rapid vehicle acceleration increases the emissions. Additional devices (air-conditioner and heater) and road inclines also increases the emissions. In this study, three light-duty vehicles were tested with WLTP, NEDC, and FTP-75, which are used to regulate the emissions of light-duty vehicles, and how much emissions can be affected by different driving cycles. The emissions gas have not shown statistically meaningful difference. The maximum emission gas have been found in low speed phase of WLTP which is mainly caused by cooled engine conditions. The amount of emission gas in cooled engine condition is much different as test vehicles. It means different technical solution requires in this aspect to cope with WLTP driving cycle.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.8
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• pp.47-55
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• 2019

This study was conducted to investigate the factors associated with electronic cigarette use by Korean adults. To accomplish this, data collected from 228,477 individuals during a community health survey conducted by the Korean Centers for Disease Control and Prevention in 2015 were analyzed by descriptive analysis, the Chi-squared test, and logistic regression analysis. The lifetime prevalence of electronic cigarette smoking was 11.1% for men and 0.8% for women. The current prevalence for electronic cigarettes smoking was 24.2% for men and 26.1% for women among lifetime users of electronic cigarettes. The lifetime experience rate of electronic cigarette smoking was significantly associated with age, educational attainment, occupation, income status and current smoking status, respectively. The current universal smoking e-cigarette is significantly related to the current smoking status, which shows a significantly higher number of current smokers than groups that have smoked in the past. The preference for electronic cigarette smoking was high. E-cigarettes were perceived by those who aimed to quit smoking as having a smoking cessation effect compared to regular cigarettes while also providing the pleasure of smoking and addressing the addiction. Therefore, e-cigarettes were highly favored because they were reflected as a solution to the dilemma of smoking. In 2014, electronic cigarette imports tripled from the previous year, and interest in electronic cigarettes is increasing worldwide. Accordingly, measures related to the prevention and discontinuation of e-cigarettes should be considered. Strengthening anti-smoking education and active promotion of anti-smoking risks is needed to improve smokers' wrong perception of smoking-related health. The WHO also reports that there is a lack of grounds to ensure or acknowledge that e-cigarettes are effective. Accordingly, it is important to identify environmental factors influencing the use of electronic cigarettes and explore the relationship between electronic cigarette recognition and use.

• Journal of the Korean Electrochemical Society
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• v.22 no.1
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• pp.36-42
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• 2019

A macroporous Sn thick film as a high capacity negative electrode for a lithium ion secondary battery was prepared by using a chemical etching method using nitric acid for a Sn film having a thickness of $52{\mu}m$. The porous Sn thick film greatly reduced the over-voltage for the alloying reaction with lithium by the increased reaction area. At the same time. The porous structure of active Sn film plays a part in the buffer and reduces the damage by the volume change during cycles. Since the porous Sn thick film electrode does not require the use of the binder and the conductive carbon black, it has substantially larger energy density. As the concentration of nitric acid in etching solution increased, the degree of the etching increased. The etching of the Sn film effectively proceeded with nitric acid of 3 M concentration or more. The porous Sn film could not be recovered because the most of Sn was eluted within 60 seconds by the rapid etching rate in the 5 M nitric acid. In the case of etching with 4 M nitric acid for 60 seconds, the appropriate porous Sn film was formed with 48.9% of weight loss and 40.3% of thickness change during chemical acid etching process. As the degree of etching of Sn film increased, the electrochemical activity and the reversible capacity for the lithium storage of the Sn film electrode were increased. The highest reversible specific capacity of 650 mAh/g was achieved at the etching condition with 4 M nitric acid. The porous Sn film electrode showed better cycle performance than the conventional electrode using a Sn powder.

• Journal of Climate Change Research
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• v.5 no.1
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• pp.83-94
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• 2014

Gangnam-gu, where the survey of residents' consciousness has been made in this study, is the district shows the highest rate of the energy consumption and greenhouse gas emission per unit area except some industrial districts such as Gwangyang, Ulsan, and Pohang. The greenhouse gas emission amount of Gangnam-gu is 4,863,765 $tCO_2$ which accounts for 10 % of the total discharging amount of Seoul, 50,330,356 $tCO_2$, which is ranked the top greenhouse gas emission rate in the commercial category and the 2nd place in the household category. The average recognition rate for the 5 subjects of the global warming phenomenons has indicated to be 83.58%. A survey questioning about the main agent to reduce the greenhouse gas, in all age groups except 20s have replied that it should be done by themselves, the residents of Gangnam-gu. For the question of the role of local government to respond to the climate change, the necessity of establishing infrastructure which is suitable for walking and biking. For the other question about the educational facilities to cope with the climate change, many answered the relevant education should be processed from the middle and high schools. For the practical activities in daily life to respond to the climate change, many replies have shown that the energy and resource conservation has been practiced pretty well broadly, but the ecomileage (former carbon mileage) has not been practiced well. Also, many replies have pointed that there were no benefits or rewards for the people who practiced the eco-mileage in their daily lives, which indicates that a kind of incentive is necessary for the efforts to respond to the climate change from the local government to execute the policy substantially and effectively. This study has the purpose to search the political countermeasures to improve the potentiality to reduce the green house gas emission rate through the residents conscious survey about climate change and the political solution by the local government to improve the certain items which showed the lower awareness rate.

• Journal of Conservation Science
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• v.34 no.6
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• pp.595-604
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• 2018

In this study, in a bid to develop natural bioadhesives for paper craft, the hanji industry, and preserving cultural assets, complex polysaccharides were extracted from brown and red algae and used as an ingredient in adhesives. Brown algae include sea trumpet, kelp, sea oak, and sea mustard, whereas red algae include Pachymeniopsis elliptica agar-agar weed, Gloiopeltis tenax, and hunori. The polysaccharides were extracted after transforming them from non-aqueous Ca complexes contained in each of the brown and red algae into water-soluble polysaccharides containing alkali metals with a solubility level of 1. and extracted Subsequently, only the polysaccharides were extracted using alcohol precipitation. The adhesion tensile strengths of kelp, a brown algae, and Pachymeniopsis elliptica, a red algae, were 21.58 and 32.99 kgf, respectively. They thus demonstrated better adhesion than that of solid glue products such as water plants (18.45 kgf) and glue sticks (20.45 kgf). The extraction yield of these polysaccharides is supposed to be determined according to their extracted environments; however, no difference in adhesion strength was seen. Further, it was found that the shapes of polysaccharides were determined by their growing environment instead of extraction environment. Use of multi-step alcohol precipitation method during extraction enabled the removal of the constituents except protein and other polysaccharides, thereby demonstrating a stable outcome without cultivation of mold. Furthermore, there was no occurrence of mold even after production of the adhesives by the simple solution method, which demonstrates the adhesive's potential as an environment-friendly adhesive material.

• Science of Emotion and Sensibility
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• v.22 no.1
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• pp.23-34
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• 2019

The U-Healthcare era has evolved with the development of the Internet of things (IoT) in the early stages of being connected as a society. Already, many changes such as increased well-being and the extension of human life are becoming evident across cultures. Korea entered the growing group of aging societies in 2017, and its silver industry is expected to grow rapidly by adopting the IoT of a super-connected society. In particular, the senior shift phenomenon has resulted in increased interest in the promotion of the health and well-being of the emergent silver generation which, unlike the existing silver generation, is highly active and wields great economic power. This study conducted in-depth interviews to investigate the characteristics of the new silver generation, and to develop the design for a wearable serious game that intends to boost the interest of the elderly in exercise and fitness activities according to their personalized physical training regimes as prescribed by the U-Hospital service. The usage scenario of this wearable serious game for the 'U-silver generation' is derived from social necessity. Medical professionals can utilize this technology to conduct health examinations and to monitor the rehabilitation of senior patients. The elderly can also use this tool to request checkups or to interface with their healthcare providers. The wearable serious game is further aimed at mitigating concerns about the deterioration of the physical functions of the silver generation by applying personalized exercise prescriptions. The present investigation revealed that it is necessary to merge the on / off line community activities to meet the silver generation's daily needs for connection and friendship. Further, the sustainability of the serious game must be enhanced through the inculcation of a sense of accomplishment as a player rises through the levels of the game. The proposed wearable serious game is designed specifically for the silver generation that is inexperienced in using digital devices: simple game rules are applied to a familiar interface grounded on the gourmet travels preferred by the target players to increase usability.

• The Korean Journal of Nuclear Medicine Technology
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• v.23 no.1
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• pp.64-68
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• 2019

Purpose In the preparation process for N-13 Ammonia injections, there were radioactive medicines adsorbed on filters remarkably. Hereby, we have compared the adsorption rate and quality test on Millex GS filter and Satorious Minisart filter, both representatively hydrophilic sterilizing filters, also evaluated which filter is more accommodative for N-13 Ammonia injection. Materials and Methods The filters used for sterilization of N-13 Ammonia injections were Millex GS filter($0.22{\mu}m$) mand Satorious Minisart filter ($0.2{\mu}m$), which are generally used to strain aqueous solutions. After the N-13 Ammonia passes through each sterilization filter, the adsorption rate of the filter (n=10) is determined by measuring not only the radioactivity through the filter also the amount of radioactivity remaining in it using a Dose Calibrator. The N-13 Ammonia injections after each filter is tested by the quality control test to conform to the Samsung Medical Center standard. Results The ratio of radioactivity passed through Millex GS indicated $29.0{\pm}17.6%$. Satorious Minisart filters output was $80.9{\pm}3.2%$, respectively. Each ratio of radioactivity adsorbed on the sterile filter was $71.0{\pm}17.6%$ for Millex GS and $19.1{\pm}3.2%$ for the Satorious Minisart filters, respectively. Furthermore, on the ratio of filtered radioactivity, Using Satorious Minisart filter showed about 2.8 times higher than using Millex GS filter. The quality testing of N-13 Ammonia injections through each filter met the Samsung Medical Center standard. Conclusion The Millex GS filter is composed of cellulose acetate and cellulose nitrate, whereas the Satorious Minisart filter if composed only of cellulose acetate. Therefore, the presence of cellulose nitrate in the membrane seems to have made differences. Therefore, the use of Satorious Minisart filter in the preparation of N-13 Ammonia injection solution minimized the loss of radioactive medicines due to filter adsorption, thereby improving the synthesis yield.

• Journal of Life Science
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• v.29 no.10
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• pp.1096-1103
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• 2019

Neuroinflammation is mediated by the activation of microglia and has been implicated in the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease and Parkinson's disease. Therefore, the inhibition of neuroinflammation may be an effective solution to treat these brain disorders. Protaetia brevitarsis seulensis is an insect belonging to the order Coleoptera and inhabits Korea, China, Japan and Siberia. P. brevitarsis seulensis is an edible insect that can be consumed as a protein source for humans. It has been reported that P. brevitarsis seulensis contains useful bioactive substances for hepatoprotection and improving blood circulation, such as indole alkaloids. Microglia cells are the main source of proinflammatory cytokines and nitric oxide (NO) in the central nervous system, which Perform neuroimmune, inflammatory, and other neurobilogical functions. In this study, we investigated the anti-neuroinflammatory effects of P. brevitarsis seulensis ethanol extract (PBE) in activated microglia cells treated with lipopolysaccgarude (LPS, 100 ng/ml). As a result, PBE significantly inhibited NO production without cytotoxicity and decreased the expression levels of inducible NO synthase and cyclooxygenase-2. In addition, the production of inflammatory cytokine secreted by LPS was also reduced by PBE. These results suggest that PBE could be a good source of functional substances to prevent neuroinflammation and neurodegenerative diseases.