• Title/Summary/Keyword: Lead in air

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Present Status of Domestic Air Transport Industry and Policy Proposal for National Carrier's Sustainable Development (국내 항공운송산업의 현황 및 지속발전을 위한 정책제언)

  • Choi, Doo-Hwan;Hwang, Ho-Won
    • The Korean Journal of Air & Space Law and Policy
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    • v.33 no.2
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    • pp.3-34
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    • 2018
  • Korea's air transport industry has a 70-year history since Korea National Airline was establishment in October 1948. Korea has 9 airlines which have international air transport business licenses, and as of 2017, air transport performance(Domestic & International) is ranked 8th in the world. Through analysis of Korea's air transport industry, this paper examines the essential problems of the domestic air transport industry and what policies and laws should be supplemented, and presents an "Policy Directions for the Air Transport Industry" that can continue to grow into a global aviation leading country in the future. Analysis of aviation statistics shows that the nation's air transport industry has a very high growth rate, and national airlines continue to invest in sustainable growth. Furthermore, new companies are also trying to enter the market. As of November 2018, four companies applied for licenses for international air transport business, one for international air transport business (cargo) license, and the Ministry of Land, Infrastructure and Transport is expected to decide whether to issue the license by first quarter of 2019. While some expect price reductions and consumer benefits through competition promotion, others worry about worsening airline financial structures and reducing safety investment due to competition. To sum up the problems of the nation's air transport industry, first, low-cost airlines focus only on attracting domestic demand, and thus have a weak foundation for continued growth. Second, the rapid growth in recent years has led to the lack of aviation professionals such as pilots and technicians and the saturation of slots at major airports. Third, since the financial soundness of airlines is not systematically managed, the financial situation of airlines can quickly deteriorate and the damage can be attributed to consumers. In order for the national airlines to continue to develop, the first is to focus on the endless demand of the global aviation market and to secure international competitiveness. Second, the government should support the airline infrastructure according to the size of the air transport industry, third, we will systematically nurture aviation experts who will lead the future of the nation's air transport industry, and finally, the government will have to continuously manage the financial status of airlines to prevent consumer damage in advance. Nowadays the air transport industry has become very competitive. Not only do airlines have to work hard for the sustainable development of national airlines, but all government agencies must support our airline companies in policy to win international competition.

Heavy Metals in Soils of the Urban Area (도시 토사중 중금속 함량)

  • 손동헌;정원태;박종필;김덕희;정성윤
    • Journal of Korean Society for Atmospheric Environment
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    • v.8 no.4
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    • pp.221-228
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    • 1992
  • In order to evaluate the degree of air pollution, soils from 125 and 60points of main streets of Seoul and Daejeon, respectively, were sampled and analyzed for the contents of lead, copper, iron and zinc by nitric acid($HNO_3$) extraction followed by atomic absorption spectrophotometry during June and September, 1990. The Pb contents of Seoul and Daejeon were 350.2$\mu$g/g and 175.9$\mu$g/g, respectively, which were 14.5times and 7.3times respectively higher than the control(24.0). In Seoul, the commercial area gave the highest value followed by resdential and industrial areas in the decreasing order, while the order in Daejeon was Industrial, commercial and residential areas. The Cu contents in Seoul and Daejeon were very similar(236.6 and 234.6, respectively) each other, and about 11times higher than the control(20.9). The concentration was highest in industrial, followed by commercial and the lowest in residential areas in Seoul, while the order in Daejeon was industrial, residential and commercial areas. The Fe contents were 25716.5 in Seoul and 22838.6 in Daejeon, both being similar to the control value(22537.0). The value was highest in industrial and next in commercial areas and the lowest in residential area both in Seoul and Daejeon. The Zn contents in Seoul and Daejeon were 728.2 and 404.0, respectively, wihch were 6.3 and 3.6times higher than the control(113.3). The value was highest in commercial and next in industrial areas and the lowest in residental area in Seoul, while the order was industrial, residential and commercial areas in Daejeon. The heavy metal content was higher in the soil of main streets than that of minor streets in Seoul. The content of lead in Seoul was higher in the streets of Chongro-ku(525.9) and Chung-ku(684.8), the central area of the city which had a heavy traffic, than those in Nowon-ku(320.3) and Kwanak-ku(312.6) which had relatively less traffic crowd. The similar pattern was observed in the content of zinc; it was higher in Chongro-ku(1305.0) and Chung-ku(1335.4) than in Nowon-ku(489.1) and Kwanak-ku(569.8). In Daejeon, the contents of lead and zinc were decreasing as the distance from Daejeon Railroad Station increased : they were respectively 157.8 and 447.7 within 2km from the station, 157.6 and 235.7 with in 2-4km, and 63.5 and 156.2 within 4-6km and 58.7 and 142.2 within 6-8km. In summary, the contents of lead, copper and zinc were generally higher in the central area of the city, areas of heavy traffic and areas of industry and commerce.

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Estimation of BTX Emission Using Pseudo-gasoline (유사휘발유 사용에 의한 BTX 배출량 추정)

  • Jeon, So-Young;Kim, Jeong;Jang, Young-Kee;Jung, Bong-Jin
    • Journal of Korean Society for Atmospheric Environment
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    • v.28 no.5
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    • pp.527-537
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    • 2012
  • The increasing consumption of pseudo-petroleum products (PPP) has been disturbing the national petroleum market. The use of PPP lead to tax evasion, disturbance of sound trading principles, component corrosion of cars, and explosion accident. Also, PPP have emitted hazardous air pollutants (HAP) including the carcinogenic aromatic hydrocarbons, PAHs and aldehydes more than regular-petroleum products. It thus has potentials to cause many environmental and health care problems. In this study, benzene, toluene and xylene emissions from road transport vehicles due to the use of pseudo-gasoline are estimated for the year 2008. The results of our study provide emission estimates of benzene, toluene and xylene for the year as 405, 1,711, 717 tonne/yr, respectively for regular-gasoline. BTX emissions are calculated as 452~515, 1,882~2,264 and 732~752 tonne/yr when the amount of pseudo-gasoline is estimated to account for 6~13% for regular-gasoline consumption. BTX emissions increased as much as 12~27, 10~32, 2~5% by using pseudo-gasoline. It is found that the pseudo-gasoline should be the key component to produce HAP in urban area.

Design of a Mechanism for Reproducing Hovering Flight of Insects (곤충의 호버링 비행을 구현하는 메카니즘의 설계)

  • 정세용;최용제
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.826-831
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    • 2004
  • Recently, studies have been carried out to develop unmanned Micro Air Vehicles(MAVs) that can search and monitor inside buildings during urban warfare or rescue operations in hazardous environments. However, existing fixed-wing and rotary-wing MAVs cannot travel at extremely low or high speeds, hover in place, or change directions instantly. This has lead researches to search for other flight methods that could overcome those drawbacks. Insect flight principles and its applications to MAVs are being studied as an alternative flight method. To take flight, insects flap and rotate their wings. These wing motions allow for high maneuverability flight such as hovering, vertical take off and landing, and quick acceleration and deceleration. This paper proposes a method for designing a mechanism that reproduces hovering insect flight, the basis for all other forms of insect flight. The design of a mechanism that can reproduce the motion that causes maximum lift is proposed, the required specifications are calculated, and a method for reproducing hovering insect flight with a single motor is presented. Also, feasibility of the design was confirmed by simulation.

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A Study on the Sensitivity Analysis of Line Source Air Quality Models (移動汚染源에 대한 大氣擴散模型의 感應度 分析에 관한 硏究 (HIWAY2, PAL, CALINE3 模型을 對象으로))

  • 김선태;김병태;김정욱
    • Journal of Korean Society for Atmospheric Environment
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    • v.5 no.1
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    • pp.1-10
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    • 1989
  • The sensitivity analysis is a method to quantify to what extent the output of a model changes with the values of input parameters. This will lead to increase model accuracy through measurement validation. Three line source air quality models, HIWAY 2, PAL, and CALINE 3 were selected for this study. The input parameters analysed included wind speed, wind direction, stability, emission rate, mixing height, receptor distance, initial dispersion coefficient, surface roughness, and averaging time. It turned out that PAL model generally showed higher concentration than other two models, and that between CALINE 3 and HIWAY 2, CALINE 3 showed higher concentration than HIWAY 2 model near the line sources, but beyond a certain downwind distances HIWAY 2 model showed higher concentration. The modesl were very sensitive to wind speed especially in the range of 0 $\sim$ 1 m/s and to wind direction near the parallel wind to streets. In case of emission rate, the output concentration was directly proportional to these input parameters. And the sensitivity of the input parameters such as stability, mixing height, initial dispersion coefficient, surface roughness, and averaging time were not very significant.

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Verification Experiment and Analysis for 6kW Solar Water Heating System(Part 3 : Optimum Design and Economic Evaluation) (6kW급 태양열 온수급탕 시스템의 실증실험 및 분석(제3보 최적설계 및 경제성평가))

  • Choi Bong Su;Lee Bong Jin;Kang Chaedong;Hong Hiki
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.17 no.1
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    • pp.16-24
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    • 2005
  • The goal of the present paper is to show the optimum design and operation conditions on 6 kW solar water heating system by using computer simulation with verified modelling. As the object functions, we took not only the amount of acquired and auxiliary heat but LCC, which has a relative importance and decisive role in economy. As expected, the maximum heat is acquired at the slope of collector with the equal degree to the latitude, facing the south. The capacity increase of the circulation pump and the storage tank lead to the increase of acquired heat and the decrease of auxiliary heat, but do not necessarily give economical advantages owing to additional electrical power consumption. In the present system, the minimum LCC can be obtained at the storage tank volume of 450 L and the mass flow rate of 0.344 kg/s.

A Study on Injection and Combustion of D.I. Diesel Engine with Electronic-hydraulic Fuel Injection System (전자유압식 분사계를 갖는 D.I. 디젤기관의 분사 및 연소에 관한 연구)

  • Kim, Hyun-Gu;Ra, Jin-Hong;Ahn, Soo-Kil
    • Journal of Fisheries and Marine Sciences Education
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    • v.9 no.1
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    • pp.83-97
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    • 1997
  • Diesel engine is widely used for ship and industry source of power because of its high thermal efficiency and reliability and durability. However it lead to air pollution due to exhaust gas, and it is important to develop diesel engine of lower air-pollution to decrease the hazardous exhaust gas emissions. As one of the ways, the study for practically using the high pressure of fuel injection and variable injection timing system is being processing. The high pressure injection, which is said to be an effective means for reducing both NOx and particulate emissions, and great improvements in combustion characteristics have been reported by many researchers. In this study, electronic-hydraulic fuel injection system and hydraulic fuel injector system have been applied to the D.I. test engine for high pressure injection and variable injection timing. The injection pressure and injection rate depending upon accumulator pressure were measured with strain gage and Bosch injection rate measuring system before fitting the system into test engine, and analyzed the characteristics of the injection system. The combustion characteristics with this injection system has been analyzed with data concerning heat release rate, pressure rising rate, ignition point, ignition delay and maximum pressure value.

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A study on the elimination of static electricity by use of beta radiation source (Beta 방사선원을 이용한 정전기 제거법에 대한 고찰)

  • 임용규
    • 전기의세계
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    • v.14 no.3
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    • pp.28-33
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    • 1965
  • This experiment is based on "the feasible improvement studies for an eliminating device of the static electricity which applies the ionizing effect of beta radiation." In order to accomplish this object, the following problems were necessarily considered to investigate and to determine. The efficiency of the elimination of static electricity was determined by means of measuring the ion current between electrically charged plates with micro-ammeter. The effects of various factors, i.e., the distance between charged plate and radiation source, the activity of radiation source, the electric otential and the area of the charged plate, the shape of the source housing, the lining of backscattering material (Pb) on the source housing surface and blowing of ionized air, on the static electricity eliminating efficiency were studied. The beta radiation sources used in this experiment were S$^{35}$ and Sr$^{90}$ -Y$^{90}$ . It was revealed that ion current increased with source activity, the electric potential and area of the plates, the lead (Pb) lining on the surface of the source housing and the velocity of the ionized air blowing. As one could expect the S$^{35}$ was more effective to increase the ion current since it is known to be a higher specific ionization source than Sr$^{90}$ -Y$^{90}$ . The detailed result and performance of the eliminating device of the static electricity are described here.ibed here.

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Optimum Management Plan of the HVAC Equipments with LCC Analysis (LCC 분석을 통한 공기조화 열원설비의 최적 관리방안)

  • Kim, Yong-Ki;Woo, Nam-Sub;Kang, Sung-Ju;Lee, Tae-Won
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.20 no.8
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    • pp.556-562
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    • 2008
  • The building HVAC systems have very different qualities of performance and durability with the superintendent's ability for management and maintenance. The poor management of these systems finally lead to the shortening of the life expectancy and result in the increase of operating costs and energy consumptions due to low efficiencies. This study presents an example of appropriate use of the LCC(Life Cycle Cost) analysis in a process of maintaining and repairing old HVAC equipments, by demonstrating the difference of optimal economic life, decrease of running cost, and energy consumption according to the management level of the HVAC equipments. But there are no reliable life expectancy and performance history data at present for optimal management of various building service equipments. Therefore, it is necessary to construct long-term database on operation results of them for more accurate and optimized LCC analysis.

A Development of the On-line Maintenance and Management System for the HVAC Systems and the Evaluation of Its Effects (공조설비 온라인 유지관리시스템 개발 및 효과분석)

  • Lee, Tae-Won;Kim, Yong-Ki;Woo, Nam-Sub
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.21 no.11
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    • pp.591-598
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    • 2009
  • The service quality with the various building equipments tends to depend on the individual superintendent's capability and efforts generally and this often lead to poor maintenances and managements of them. N-BMS(Networked Building Management System), proposed in this study, is a new type of building management method, which links principal equipments within many buildings into a communication network and carries out several significant missions such as fault detection, deterioration diagnosis and control the equipments and so on, as well as monitoring which is the main and unique purpose of the conventional BMS. How to construct the N-BMS was considered to keep performance of equipments high and thus to save energy and resource. LCC(Life Cycle Cost) based analysis was also performed in order to verify the effects of some maintenance and management works for the building HVAC systems.