• Title/Summary/Keyword: Emission trend

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Electron Emission Property of Carbon Nanotubes Grown Using Different Source Gases

  • Han, Jae-Hee;Lee, Tae-Young;Yoo, Ji-Beom;Park, Chong-Yun;Jung, Tae-Won;Yu, Se-Gi;Yi, Whi-Kun;Kim, Jong-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2002.08a
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    • pp.658-661
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    • 2002
  • Chemical species during growth of carbon nanotubes (CNTs) in direct current-plasma enhanced chemical vapor deposition were studied in details using $C_3H_4-NH_3$ and $CO-NH_3$ mixtures through optical emission spectroscopy (OES). In the $C_3H_4-NH_3$ system, the relative intensities of CN (388.3 nm) and CH (431.4 nm) decreased and that of $C_2$ (436 nm) increased, leading to $sp^2$-graphization into the CNT structure, leading to improvement of field emission property of CNTs. In the $CO-NH_3$ system, the trend is completely reversed. Attributing to the atomic oxygen for helping the graphitization of carbon, CNTs could be grown under the flow rate of CO (180 sccm)-$NH_3$ (10 sccm). Through these results, we suggest the growth mechanism in our system.

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R&D Status of NOx and Flue-gas Treatment Technologies in KIER (KIER의 NOx 및 연소배가스 처리기술 개발현황)

  • Min, Byoung-Moo;Choi, Sang-Il
    • 한국연소학회:학술대회논문집
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    • 2003.05a
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    • pp.295-300
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    • 2003
  • In Korea, the emission standards for air pollutants will be more tighten from Jan. 2005. Especially, the new emission standards is focused on the nitrogen oxide. From this trend of standards, nitrogen oxide emission is hot issue in energy fields. Also, we have a new environmental problem, the carbon dioxide emission, which are related to the global warming. To solve the environmental problems, we must define the situation of clean-up technologies level in Korea and decide the direction of R&D for flue gas cleaning technologies. Now, this paper discus briefly on the De-NOx R&D activities and the large scale testing facility for flue gas clean-up technologies in Korea Institute of Energy Research. These discussions are contribute to the increasing of the R&D activities for flue gas clean-up technologies in Korea.

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Study on the Real-Time Leak Monitoring Technique for Power Plant Valves (발전용 밸브누설 실시간 감시기술 연구)

  • Lee, S.G.
    • Journal of Power System Engineering
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    • v.11 no.1
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    • pp.39-44
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    • 2007
  • The purpose of this study is to verify availability of the acoustic emission in-situ monitoring method to the internal leak and operating conditions of the major valves at nuclear power plants. In this study, acoustic emission tests are performed when the pressurized temperature water and steam flowed through glove valve(main steam dump valve) and check valve(main steam outlet pump check valve) on the normal size of 12 and 18". The valve internal leak monitoring system for practical field was designed. The acoustic emission method was applied to the valves at the site, and the background noise was measured for the abnormal plant condition. To improve the reliability, a judgment of leak on the system was used various factors which are AE parameters, trend analysis, frequency analysis, voltage analysis and amplitude analysis of acoustic signal emitted from the valve operating condition internal leak.

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Development of Diagnosis Technique for Converter Bearings by Using Acoustic Emission (음향방출기법을 이용한 전로베어링 안전진단 기술개발)

  • 박경조
    • Journal of the Korean Society of Safety
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    • v.18 no.2
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    • pp.6-15
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    • 2003
  • A method is presented for diagnosing the converter bearings by using acoustic emission. The flaking mechanism causing the large-scale bearing for furnace to flaw is investigated and a possibility of defect is verified by Finite Element method. he diagnosis logic is proposed fir detecting the flaw of a non-continuous rotating machine. It is proved that the acoustic emission energy can be used as a representative parameter for an acoustic event. Applying the method to the tilting bearings for steel mill in operation, the effectiveness of this logic is evaluated. It is shown that AE signal is generated only when the bearing is tilting, and the trend analysis can be focused upon this process.

A study on Technical Development a Trend of Digital Image Information (디지털 영상정보의 기술 발전 동향 연구)

  • Kim, Soo-Yong;Jee, Suk-Kun
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2008.05a
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    • pp.755-760
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    • 2008
  • 영상 Display의 시장 동향과 기술 동향에 대하여 기술하였다. 영상 Display 로서는 그밖에 유기 EL(Electroluminescence), FED(Filed Emission Display) 등이 있고 차세대 Display도 개발이 진행되고 있다. 양자 모두 스스로 발광하는 형태를 취하기 위해서는 Back Light가 필요하지 않고, 박형과, 넓은 시야각, 또한 응답 속도가 빠르고 때문에 액정 Display 보다 유리하리라 판단된다.

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A Study on the Power Output and Exhaust Emission using the Fuel Vaporizing Device in Spark-Ignition Engine (기화혼합장치를 사용한 스파크 점화기관의 기관성능 및 배기성능에 관한 연구)

  • 이성열
    • Journal of the korean Society of Automotive Engineers
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    • v.9 no.6
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    • pp.53-59
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    • 1987
  • The effect of the three types of fuel vaporizing device on the engine torque and exhaust emission was investigated. Among the three types of fuel vaporizing device designed for the experiments, a 88mm long device with mesh around the inside pipe showed stable lean mixture combustion up to 21:1 air-fuel ratio and reduced the exhaustion of CO and HC. Compared with the general trend in the decrease of engine torque it was observed that the decrease of engine torque in this lean mixture combustion with the new device was small.

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A Study on the Exhaust Characteristics of Pollutants from Recreational Vehicle (RV) in Korea (국내 다목적저동차의 오염물질 배출특성 연구)

  • Jung Sung Woon;Ryu Jeong Ho;Lyu Young Sook;Lim Cheol Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.22 no.1
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    • pp.127-134
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    • 2006
  • In Korea, the number of recreational vehicle (RV) has been increased dramatically recent year. Now there are emission regulations for RV which include pollutants such as CO, HC, NOx, PM. However considering the trend of preferring RV, there needs more strict strategies to control emissions from this type of vehicle. For that reason, we studied emission characteristics of RV and provided basic emission data to evaluate the contribution of RV to the total air pollutant emissions and to establish RV emission management plan. A total of 21 RV were tested on the chassis dynamometer system ranging from small to large engine displacement by vehicle speed, fuel types, regulations and fuel efficiency in order to investigate the characteristics of CO, HC, NOx and PM. For the test modes, 10 different driving speed modes and CVS-75 mode were used. On the basis of this study, RV pollutants emission factors and management strategies will be proposed.

A new model and testing verification for evaluating the carbon efficiency of server

  • Liang Guo;Yue Wang;Yixing Zhang;Caihong Zhou;Kexin Xu;Shaopeng Wang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.17 no.10
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    • pp.2682-2700
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    • 2023
  • To cope with the risks of climate change and promote the realization of carbon peaking and carbon neutrality, this paper first comprehensively considers the policy background, technical trends and carbon reduction paths of energy conservation and emission reduction in data center server industry. Second, we propose a computing power carbon efficiency of data center server, and constructs the carbon emission per performance of server (CEPS) model. According to the model, this paper selects the mainstream data center servers for testing. The result shows that with the improvement of server performance, the total carbon emissions are rising. However, the speed of performance improvement is faster than that of carbon emission, hence the relative carbon emission per unit computing power shows a continuous decreasing trend. Moreover, there are some differences between different products, and it is calculated that the carbon emission per unit performance is 20-60KG when the service life of the server is five years.

A Study on the Estimation of GHGs Emission by Military Sector (군사부문 온실가스 배출량 산정에 관한 연구)

  • Song, Ki Pong;Choi, Sang Jin;Kim, Jeong;Jang, Young Kee
    • Journal of Climate Change Research
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    • v.8 no.2
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    • pp.177-186
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    • 2017
  • In this research, we have developed standardized procedures for preparing of emission inventories on military sector. The procedures are as follows; 1) Identify all relevant emission sources list of military sector in Republic of Korea. 2) Select methods to estimate GHGs emissions by source categories such as heating boilers, tactical vehicles, military vessels and military aviation from US EPA, IPCC, EEA/EMEP, and ROK Ministry of Environment. 3) Identify and select data sources for activities and parameters from Korea annual oil statistics and Korea Procurement system. 4) Compare with each GHGs emission used by each activities. The conclusive results utilized by emission source categories and associated factors are described as follows; In 2013, GHGs was estimated 2,656 kilotons $CO_2-eq$ emitted by military sector. The diesel combustion contributed from a minimum of 43.8% to a maximum of 50.2% and JP-8 contributed from a minimum of 43.7% to a maximum of 52.8% to the 2001~2015 GHGs emission trend. In the result of comparing GHGs emissions with Korea Annual Oil Statistics (Tier 1) and supplied fuel through the Korea Procurement System (Tier 2) in 2015, the total GHGs emission was 2,867 kilotons $CO_2-eq$ estimated by Tier 2 is similar to the emission estimated by Tier 1. However, this reveals that the GHGs emission separated by local areas were a lot of different from Tier 1 and 2. The cause of difference between Tier 1 and Tier 2 was that Korea annual oil statistics utilized data from a fuel supplier. The data does not reflect the reality of the location of end user.