• Journal of Sensor Science and Technology
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• v.8 no.2
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• pp.163-170
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• 1999

A programmable A/D converter for an embedded fiber-optic combustion pressure sensor has been designed with 8 N and P channel MOSFETs, respectively. A local field enhancement for reducing programming voltage during writing as well as erasing an EEPROM device is introduced. In order to observe linear programmability of the EEPROM device during programming mode, a cell is developed with a $1.2\;{\mu}m$ double poly CMOS fabrication process in MOSIS. It is observed that the high resolution, of say 10mVolt, is valid in the range 1.25volts to 2volts. The experimental result is used for simulating the programmable 8 bit A/D converter with Hspice. The A/D converter is demonstrated to consume low power, $37\;{\mu}W$ by utilizing a programming operation. In addition, the converter is attained at the conversion frequency of 333 MHz.

• Journal of the Korean Society of Propulsion Engineers
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• v.21 no.4
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• pp.21-27
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• 2017

In this paper, in order to control the burning rate and pressure exponent of HTPB/AP/Al based propellant for the improvement of performance, the effect of the size ratio of AP particles and various contents of Butacene as burning catalyst on combustion properties was investigated. In the propellant formulation with both $28{\mu}m$ Al of 23% and Butacene of 3%, the burning rate and pressure exponent were increased with increasing the contents of $9{\mu}m$ AP particles. And the burning rate was increased with increasing the contents of Butacene with showing the relatively low pressure exponent in the propellant containing Butacene. However, the significant variations of pressure exponent by contents of Butacene were not observed.

• Fire Science and Engineering
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• v.20 no.4 s.64
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• pp.72-76
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• 2006

Polymer/clay nanocomposites have generated considerable interests in the past decade because adding just tiny amount of clay to the polymer matrix could produce a dramatic enhancement in physical, thermal and mechanical properties. Smectite clays, such as montmorillonite (MMT), are of great industrial value because of their high aspect ratio, plate morphology, intercalative capacity, natural abundance and low cost. In this study, PE/MMT nanocomposites were directly prepared by melt intercalating PE and the modified clay. The nanostructure was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their flame retardant properties were measured and discussed by limiting oxygen index (LOI), char yield and smoke mass concentration. And their thermal stabilities were measured by differential thermogravimetric (DTG) and thermogravimetric analysis (TGA). The PE/MMT nanocomposites proved more effective the conventional composites in reinforcement. Two functions in the thermal stability of the PE/MMT nanocomposite, one is the barrier effect to improve the thermal stability, and another is catalysis, leading to a decrease of the thermal stability. The flammability was greatly decreased due to the formation of the clay-enriched protective char during the combustion.

• Korean Journal of Medicinal Crop Science
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• v.27 no.3
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• pp.218-231
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• 2019

Background: We recently reported that Salvia plebeia R. Br. extracts suppress leukotriene production and effectively inhibit the airway inflammatory response by modulating inflammatory chemokine and cytokine expression. Here, we investigated the synergistic airway anti-inflammation effect of Salvia plebeia and Panax ginseng (Korean red ginseng, KRG) that has been used to treat various immune diseases such as asthma. Methods and Results: To evaluate the synergistic airway anti-inflammatory effect of Salvia plebeia and KRG, we measured the inhibitory effect of monotheraphy with either or co-theraphy with both on leukotriene and reactive oxygen species (ROS) production. Using coal a combustion, fly ash, and diesel exhaust particle (CFD)-induced respiratory disease mouse model, we found that co-theraphy synergistically suppressed airway inflammatory signs such as alveolar wall thickness and collagen fibers deposition, and decreased the number of total cell, $CD11b^+Gr-1^+$ cells, and inflammatory cytokines (IL17A, TNF, MIP-2 and CXCL-1) in bronchoalveolar lavage (BAL) fluid. Conclusions: We confirmed respiratory protection as a therapeutic effect of the Salbia plebeia-KRG 3 : 1 complex (KGC-03-PS) via anti-tracheal muscle contraction and expectorant animal studies using a CFD-induced respiratory disease mouse model.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.22 no.1
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• pp.181-186
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• 2022

The world's electric automobile sector has shifted beyond technological environmental changes to a stage that has an impact on the market environment. And automakers are shifting from the existing strategy of "technological advantage → brand enhancement → sales expansion of existing internal combustion engine vehicles" to the expansion of the electric automobile market itself, which is to enhance market competitiveness. In addition, competition in the electric automotive parts market is expected to intensify due to the expansion of the business areas of existing parts makers and the entry of new companies, and development cooperation is expected to actively proceed to improve the efficiency of major eco-friendly parts. Along with this prospect, electric vehicles are expected to change the overall structure of the automobile industry, the overall growth of the electric vehicle value chain such as batteries, power trains (motors, power management and control systems), electric vehicle production, and charging infrastructure Is expected. Therefore, in this thesis, in order to cultivate a variety of high-quality human resources that companies want to keep pace with the changing automobile industry, we study a professional manpower training program that leads the growth engine of the electric automobile industry.

• Journal of the Korea Institute of Building Construction
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• v.17 no.4
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• pp.313-320
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• 2017

Flue gas desulfurization gypsum(FDG) is produced when removing sulfur oxides from combustion gas generated by coal power plant. However, the recycling of FDG is still limited to the certain purposes. In order to expand the possible application of FDG, this study aims to utilize FDG as an activator for ground granulated blast furnace slag. FDG produced by dry- and wet-process were used for the experiments. Slag paste specimens were produced by mixing with deionized water and simulated pore solution, and the role of FDG as an activator for blast furnace slag was evaluated using hydration study by XRD analysis and compressive strength development. According to the results, dry-type FDG was found to work as an activator for blast furnace slag without the presence of soluble alkalis. However, wet-type FDG needs assistance by soluble alkalis in order to work as an activator for blast furnace slag. It was also found that the substitution of dry- and wet-type FDG into blast furnace slag can increase the 28 day compressive strength of slag paste. It is expected that efficient and economical recycling of FDG will be possible if quantitative analysis of strength enhancement according to substitution rate of both dry- and wet-type FDG.

• Journal of the Korean Society of Tobacco Science
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• v.13 no.2
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• pp.5-20
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• 1991

For the quality enhancement of harvested-year leaf tobacco to the quality of 2-year naturally aged leaf tobacco, cellulose and nicotine degradative bacteria were isolated and identified. Effects of artificial fermentation treated cellulase and nicotine degradative bacteria on the quality of leaf tobacco were investigated from the chemical and sensory points of view. 1, Changes in chemical composition of leaf tobacco resulted from the addition of cellulase extracted from Cellulomonas sp. [3ml(${\mu}{\textrm}{m}$ D-glucose/ml. mil-1) of enzymes solution 11009 of leaf tobacco] and nicotine degradative bacteria, Pseudomonas sp. 2ml(IX109 cells$\div$ 100g of leaf tobacco), and subsequently fermented at 40${\mu}{\textrm}{m}$$^{\circ}C$, 65% R. H. for 40 days are as follows : 1) Content of crude fiber decreased 12% It took 9 min, 53 sec. to reach full combustion in control group but took only 7 min. 47 sec. in the treated group, taking almost equal time to 2-year naturally aged leaf tobacco(7 min. 35sec.). 2) Light intensity of control group was 60.96% with bright lemon color but that of treated leaf tobacco accounted for 47.69 with orange to dark brown color series, which was almost equal to the value, 45.69, of 2-year naturally aged leaf tobacco. 3) Linoleic acid, serving mild taste among organic acids, amounted to 1.llmg/g in control group but increased to 1.35m9/9 in the treated leaf tobacco, identical to the content(1.35mg/g) of 2-year naturally aged leaf tobacco. 4) Content of solanone, on of the typical leaf tobacco flavor compounds, accounted for 2.95% in control group but increased to 2.87% in treated group. 5) Methyl furan, useful flavor compound in smoke composition, accounted for 17.6$\mu\textrm{g}$/cig. in control group but increased to 25.9$\mu\textrm{g}$/cig. in treated group. However, acroleine decreased from 69.3$\mu\textrm{g}$/cig. in control group to 58.6$\mu\textrm{g}$/cig. in treated group 2. In sonsory test, mild taste evaluation of control group scored 5.47 and treated group 7.93 which was evaluted almost equal to the value(8.00) of 2-year naturally aged leaf tobacco. Aroma evaluation of control group scored 5.60, treated group 8.20, and 2-year naturally aged leaf tobacco 8.33. In addition, total harmony taste of control group showed 5.67, treated group 8.07 (p<0.01), and 2-year naturally aged leaf tobacco 8.00. From these results, it can be said that quality of treated leaf tobacco is not inferior to that 2-year naturally aged leaf tobacco.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.725-732
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• 2017

Weight reduction is one of the important issues in the automotive industry and the development of internal combustion engines vehicles, future vehicles, and eco-friendly vehicles for improving fuel efficiency. The objective of this study is to investigate the improvement of driving performance by weight reduction and optimum design for a formula-type self-designed on-road vehicle. This study is divided into the four steps. Firstly, the engine room was replaced and designed with a lighter engine. Secondly, an optimization study was conducted to simplify and lighten the vehicle components with the design of the frame. Thirdly, the structure design was optimized and the suspension was analyzed with the design of the frame. Finally, the design of an upright and hub with reduced weight was carried out using lighter parts. As a result, we reduced the weight of the vehicle by 48.5kg compared to the previous year (19.5%) and increased the acceleration from 6.8 s to 5.8 s.s.

• Journal of Radiation Industry
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• v.10 no.4
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• pp.173-179
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• 2016

Coals and coal ashes, raw materials and by-products, in coal-fired power plants contain naturally occurring radioactive materials (NORM). They may give rise to internal exposure to workers due to inhalation of airborne particulates containing radioactive materials. It is necessary to characterize radioactivity concentrations of the materials for assessment of radiation dose to the workers. The objective of the present study was to analyze radioactivity concentrations of coals and by-products at four coal-fired plants in Korea. High purity germanium detector was employed for analysis of uranium series, thorium series, and potassium 40 in the materials. Radioactivity concentrations of $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were $2{\sim}53Bq\;kg^{-1}$, $3{\sim}64Bq\;kg^{-1}$, and $14{\sim}431Bq\;kg^{-1}$ respectively in coal samples. For coal ashes, the radioactivity concentrations were $77{\sim}133Bq\;kg^{-1}$, $77{\sim}105Bq\;kg^{-1}$, and $252{\sim}372Bq\;kg^{-1}$ in fly ash samples and $54{\sim}91Bq\;kg^{-1}$, $46{\sim}83Bq\;kg^{-1}$, and $205{\sim}462Bq\;kg^{-1}$ in bottom ash samples. For flue gas desulfurization (FGD) gypsum, the radioactivity concentrations were $3{\sim}5Bq\;kg^{-1}$, $2{\sim}3Bq\;kg^{-1}$, and $22{\sim}47Bq\;kg^{-1}$. Radioactivity was enhanced in coal ash compared with coal due to combustion of organic matters in the coal. Radioactivity enhancement factors for $^{226}Ra$, $^{228}Ra$, and $^{40}K$ were 2.1~11.3, 2.0~13.1, and 1.4~7.4 for fly ash and 2.0~9.2, 2.0~10.0, 1.9~7.7 for bottom ash. The database established in this study can be used as basic data for internal dose assessment of workers at coal-fired power plants. In addition, the findings can be used as a basic data for development of safety standard and guide of Natural Radiation Safety Management Act.

• Journal of Energy Engineering
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• v.23 no.4
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• pp.61-72
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• 2014

This paper analyzed transition pathways toward a low carbon society in Korea to meet global $2^{\circ}C$ climate target. Lower economic growth, industrial structure change, enhance of energy demand management, decarbonization of power sector, and replacement of low carbon fuel could reduce greenhouse gas (GHG) emission from fuel combustion in 2050 by 67% against in 2011, or by 74% against in BAU (Business-As-Usual). Lower economic growth contributes to 13% of cumulative emission reduction relative to BAU, industrial structure change 9%, enhance of energy demand management 72%, decarbonization of power sector 5% and replacement of low carbon fuel 1% respectively. Final energy consumption in 2050 needs to be reduced to 50% relative to 2011, or to 41% relative to BAU. Nuclear, coal and renewable energy represent 31%, 40%, 2% respectively among electricity generation in 2011, but 38%, 2%, 32% in 2050. CCS represents 23% of total generation in 2050. Emission intensity of electricity in 2050 was decreased to 19% relative to 2011, or to 24% relative to BAU. Primary energy in 2050 was decreased to 64% compared to 2011, or to 44% compared to BAU. Final energy consumption, primary energy supply and GHG emission from fuel combustion from 1990 to 2011 increased by 176%, 197%, 146%. Radical change from historical trend is required to transit toward a low carbon society by 2050. Appropriate economic growth, structural change to non-energy intensive industries, energy technology research, development and deployment (RD&D) in terms of enhancement of energy efficiency and low carbon energy supply technologies, and fuel change to electricity and renewable energy are key instruments.