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Comparison of water quality of domestic natural mineral water (국내 먹는샘물의 수질특성비교)

  • Doo, Yong-Kyoon;Kim, Jun-Hwan;Kim, Chang-Su;Chang, Duk
    • Journal of environmental and Sanitary engineering
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    • v.15 no.1
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    • pp.88-94
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    • 2000
  • The purpose of this study was to analyze and compare the contents of minerals and ionic components in domestic commercial natural mineral waters, and to investigate the relationship between water quality and characteristics of suspended and rocks there of its source. All mineral waters tested in this study met the korean mineral water quality guideline, although chemical components varied widely depending upon the geological characteristics and degree of urbanization of the source area or physical water treatment method. The water quality of commercial bottled water was different from that of source water, especially in cationic components, and showed a tendency to become worse with time elapsed. The water quality on the bottle was also different from the measured quality.

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A Biovoltine Silkworm Variety, Huayuan${\times}$Dongshen, That is Resistant to Fluoride Contamination

  • Xu, Anying;Lin, Changqi;Hou, Chengxiang;Zhang, Yuehua;Li, Muwang;Sun, Pingjiang
    • International Journal of Industrial Entomology and Biomaterials
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    • v.13 no.1
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    • pp.1-5
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    • 2006
  • The major dominant fluoride-endurance (Dfe) gene was introduced into the commercial varieties by crossing and pedigree selection to breed silkworm races that could normally develop in the area that polluted by fluoride. After backcrossed for two generations, the Dfe gene was made homozygous, and individuals with good economic characters were selected to generate next generation. After 8 generations of selection, their characters became stable, and the silkworm variety which is resistant to fluoride, Huayuan${\times}$Dongsheng, for spring rearing were bred.

Performance and Safety of EDLC of PVdF-PVP Mixed Binder (PVdF-PVP 복합결합제를 이용한 EDLC의 성능과 안정성)

  • 김경민;오호성;정세일;이용욱;강안수
    • Proceedings of the Safety Management and Science Conference
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    • 2001.05a
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    • pp.319-324
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    • 2001
  • High surface area and high pore volume activated carbon was prepared by KOH activation of rice hull. The electrodes were fabricated by compounding the commercial and rice hull activated carbons with PVdF and PVdF-PVP mixed binders without addition of conductivity improver. The electrodes fabricated with rice hull activated carbon and PVdF-PVP mixed binders showed the best performance because the PVP played as a pore-forming agent. The electrode exhibited excellent electrochemical characteristics having 7.9 W.h/kg of energy density, 33.5 F/g of speific capacitance, 0.7 $\Omega$ of ESR and good efficiency of self-discharge compared with that fabricated with commercial activated carbons.

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Critical Issues on Health Risk of Asbestos (석면과 건강에 대한 이슈)

  • Yoon, Chung-Sik
    • Journal of Environmental Health Sciences
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    • v.35 no.5
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    • pp.426-432
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    • 2009
  • Asbestos is a commercial term of natural occurring silicated minerals and forms long, thin fibers. Chrysotile, the serpentine asbestos, accounts for most use in commercial use. Asbestos is well known health hazard material and it is proved that inhalation of asbestos fibers leads to increased risk of developing several diseases such as lung cancer, mesothelioma, asbestosis. In these days, people most at risk for exposure are maintenance and construction workers and general citizens who are working on and close to the work area at which asbestos containing material is disturbing. Non asbestiform, though its chemical composition is same with regulated asbestos, is known to be less hazardous than asbestiform. Exposure guideline, 0.01 f/ml, is not safe level in terms of health risk. It is reasonable to take preventable action when asbestos is suspicious. In Korea, it is necessary to clarify the concept between hazard and risk, to differentiate asbestiform from non asbestiform, to make regulations for compensation for asbestos related patients, to manage future exposure for general citizens.

Analysis Model Development for Designing of Hydraulic Power Steering System (유압식 동력조향 장치 설계를 위한 해석 모델 개발)

  • Jang, Joo-Sup;Yoon, Young-Hwan
    • Transactions of the Korean Society of Automotive Engineers
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    • v.16 no.1
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    • pp.158-165
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    • 2008
  • Hydraulic power steering system has been adopted in seniority passenger and commercial vehicle system for an easy maneuverability and a smoother ride. In this study, hydraulic power steering system analysis model which includes hydraulics and mechanical sub-systems was developed using commercial software, AMESim in order to predict characteristics for various steering components. Each component which constructs system was modeled and verified by experimentally obtained characteristics curves of each components. The agreement between simulation and experimental results shows the validity of the simulation model. The parameter sensitivity analysis such as valve opening area, torsional stiffness for system design are carried out by the analysis and experimental method.

Space-based Ocean Surveillance and Support Capability: with a Focus on Marine Safety and Security (인공위성 원격탐사의 활용: 선박 감시 기법)

  • Yang, Chan-Su
    • Proceedings of KOSOMES biannual meeting
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    • 2006.05a
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    • pp.41-45
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    • 2006
  • From the 1978 Seasat synthetic aperture radar(SAR) to present systems, spaceborne SAR has demonstrated the capability to image the Earth's ocean and land features over broad areas, day and night, and under most weather conditions. The application of SAR for surveillance of commercial fishing grounds can did in the detection of illegal fishing activities and provides more efficient use cf limited aircraft or patron craft resources. In the area of vessel traffic monitoring for commercial vessels, Vessel Traffic Service (VTS) which uses the ground-based radar system has some difficulties in detecting moving ships due to the limited detection range cf about 10 miles. This paper introduces the field testing results of ship detection by RADARSAT SAR imagery, and proposes a new approach for a Vessel Monitoring System(VMS), including VTS, and SAR combination service.

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Uncertainty Analysis and Compensation of the Cell for Permittivity Measurement of Solid Materials (고체재료의 유전율 측정용 Cell의 불확도 분석과 보상)

  • Kim, Han-Jun;Yu, Kwang-Min;Kang, Jeon-Hong;Han, Sang-Ok
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.21 no.1
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    • pp.53-56
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    • 2008
  • The commercial parallel plate electrodes system with guard-ring electrode have been widely used for measurement of dielectric constants of solid materials. And the specification of the electrodes system is about 1 % of measurement uncertainty. This measurement uncertainty is only estimated the error come from mechanical measurements such as the area of the electrodes and the gap between the electrodes except the error come from the air gap between the electrodes and dielectric specimen. Because it is impossible to measure the air gap. This study analyze the total measurement uncertainties of the commercial dielectric constant test cell using 3 kinds of Standard Reference Materials. As a results, the total measurement uncertainty is much bigger than 1 % and the most of the uncertainty can be reduced by compensation of the error values evaluated in this study.

Nonuniformity of Energy Absorption Capabilities of ZnO Varistors

  • He, Jin-Liang;Han, Se-Won;Cho, Han-Goo;Kang, Hyung-Boo
    • The Korean Journal of Ceramics
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    • v.4 no.1
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    • pp.47-52
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    • 1998
  • The nonuniformity of energy absorption capability of ZnO varistor is systematically discussed in this paper. The nonuniformity of electrical characteristics and microstructure leads to decrease the energy absorption capability of ZnO varistor. The energy absorption capabilities were measured under different current waves, the experimental results stated that they have highly scattered phenomena. The influences of varistor surface area and nonuniformity of electrical characteristics to the energy absorption capability and the nonuniformity of commercial ZnO varistors were analyzed. There is a high nonuniformity existing in the energy absorption capability of commercial ZnO varistors.

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A Study on characteristics of AUC Powder Prepared with the Waste AC Solution (폐 AC용액으로부터 제조된 AUC분말의 특성에 대한 연구)

  • 정경채;김태준;최종현;박진호
    • Journal of the Korean Ceramic Society
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    • v.33 no.3
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    • pp.332-338
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    • 1996
  • This study was investigated on the recycle feasibility of the waste AC(Ammonium Carbonate) solution produ-ced in a commercial AUC(Ammonium Uranyl Carbonate) conversion plant. AUC particles were produced with the AC solution which was prepared with AC solid-agent instead of ammonia and carbon-dioxide gases. As the results particles of monoclinic shapes has been obtained regardless of the pH change if the carbonate concentration is sufficient in the mother liquore. Also a lot of twinned or aggregated particles were formed in case of the increase of pH in the reaction system but not affected in the change of temperature. Consequen-tly the characteristics of the particles which converted for AUC were produced withAC solution to UO2, particles specific surface area shape sintered density and others were similar to that of the particles which were produced with gases only when the pellets are fabricated in the nuclear fuel manufacturing process So the waste AC solution which is produced in the commercial AUC conversion plant is possible to recycle.

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An Efficient 2-D Conveolver Chip for Real-Time Image Processing (효율적인 실시간 영상처리용 2-D 컨볼루션 필터 칩)

  • 은세영;선우명
    • Journal of the Korean Institute of Telematics and Electronics C
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    • v.34C no.10
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    • pp.1-7
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    • 1997
  • This paper proposes a new real-time 2-D convolver filter architecture wihtout using any multiplier. To meet the massive amount of computations for real-time image processing, several commercial 2-D convolver chips have many multipliers occupying large VLSI area. Te proposed architecture using only one shift-and-accumulator can reduce the chip size by more than 70% of commercial 2-D convolver filter chips and can meet the real-time image processing srequirement, i.e., the standard of CCIR601. In addition, the proposed chip can be used for not only 2-D image processing but also 1-D signal processing and has bood scalability for higher speed applications. We have simulated the architecture by using VHDL models and have performed logic synthesis. We used the samsung SOG cell library (KG60K) and verified completely function and timing simulations. The implemented filter chip consists of only 3,893 gates, operates at 125 MHz and can meet the real-time image processing requirement, that is, 720*480 pixels per frame and 30 frames per second (10.4 mpixels/second).

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