• Title/Summary/Keyword: emission coefficient

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The Influence of Industrial Structure Upgrading on Carbon Emission Efficiency in China

  • Song, Luyan
    • The Journal of Industrial Distribution & Business
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    • v.10 no.2
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    • pp.7-15
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    • 2019
  • Purpose - The industrial structure upgrading can play an important role in promoting the carbon emission efficiency. Thus, this paper attempts to study the impact of industrial structure upgrading on carbon emission efficiency in order to reduce carbon emissions. Research design, data, and methodology - This paper selects panel data of 30 provinces and municipalities (autonomous regions) in China from 2001 to 2016, and divides them into three regions. The Moore index is used to measure the industrial structure upgrading, the non-radial SBM model based on undesired output is used to measure the slack variable to calculate the total factor carbon emission efficiency. Finally the impact of industrial structure upgrading on the carbon emission efficiency are analyzed. Results - It is found that the Moore index and the carbon emission efficiency in the eastern region is the highest in the three regions. Conclusions - The influence of various influencing factors on carbon emission efficiency is different between regions. The Moore index has a positive effect on the carbon emission efficiency in the eastern region, and has a negative influence coefficient on the central region. The effect on the western region is not obvious.

The Effect of Fuel Injection Timing on the Combustion and Emission Characteristics of a Natural Gas Fueled Engine at Part Loads

  • Cho, Haeng-Muk
    • Journal of Advanced Marine Engineering and Technology
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    • v.32 no.7
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    • pp.1013-1018
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    • 2008
  • For a sequential port fuel injection natural gas engine, its combustion and emission characteristics at low loads are crucial to meet light duty vehicle emission regulations. Fuel injection timing is an important parameter related to the mixture formation in the cylinder. Its effect on the combustion and emission characteristics of a natural gas engine were investigated at 0.2 MPa brake mean effective pressure (BMEP)/2000 rpm and 0.26 MPa BMEP/1500 rpm. The results show that early fuel injection timing is beneficial to the reduction of the coefficient of variation (COV) of indicated mean effective pressure (IMEP) under lean burn conditions and to extending the lean burn limits at the given loads. When relative air/fuel ratio is over 1.3, fuel injection timing has a relatively large effect on engine.out emissions. The levels of NOx emissions are more sensitive to the fuel injection timing at 0.26 MPa BMEP/1500 rpm. An early fuel injection timing under lean burn conditions can be used to control engine out NOx emissions.

Effect of Sc doping on the electron emission properties of an MgO protective layer.

  • Matulevich, Y.T.;Lee, Min-Suk;Moon, Sung-Hwan;Choi, Jong-Seo;Zang, Dong-Sik
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1057-1059
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    • 2008
  • Study of the ion-induced-, photo- and exo-electron emission from a Sc doped MgO protective layer has been performed. It is established that doping with Sc increases photo- and especially exo-electron emission from MgO films while the ion-induced electron emission coefficient $\gamma$ stays unchanged.

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Prediction of VOCs Emissions from Multi-layers Materials (복합자재에서의 VOCs 방출량 예측에 관한 연구)

  • Yoon, Chang-Hyun;Kwon, Kyung-Woo;Park, Jun-Seok
    • Proceedings of the SAREK Conference
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    • 2005.11a
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    • pp.9-14
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    • 2005
  • The purpose of this study is to predict VOCs emission rates from multi-layers materials, which are composed of single-layer materials having various VOCs emission rates, by using effective diffusion coefficients of the single-layer materials. The study was consisted of two parts; the one is the prediction of VOCs emission rates from multi-layer materials through numerical methods. The other is the measurement of VOCs emissions rates of wall composite and floor composite in Mock-up rooms for comparing the prediction and the experiments' values. The results of the study show that the short-term VOCs emission rates of multi-layers materials can be predicted from the effective diffusion coefficients of single materials in odor accuracy.

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Estimating Ozone Sensitivity Coefficients to NOx and VOC Emissions Using BFM and HDDM for A 2007 June Episode (HDDM과 BFM을 이용한 NOx와 VOC 배출량에 대한 오존민감도계수 산정 및 결과 비교: 2007년 6월 수도권 사례)

  • Kim, Soon-Tae
    • Journal of Environmental Science International
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    • v.20 no.11
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    • pp.1465-1481
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    • 2011
  • The accuracy of ozone sensitivity coefficients estimated with HDDM (High-order Decoupled Direct Method) can vary depending on the $NO_x$ (Nitrogen Oxides) and VOC (Volatile Organic Compound) conditions. In order to evaluate the applicability of HDDM over the Seoul Metropolitan Area (SMA) during a high ozone episode in 2007 June, we compare BFM (Brute Force Method) and HDDM in terms of the $1^{st}$-order ozone sensitivity coefficient to explain ozone change in response to changes in NOx and VOC emissions, and the $2^{nd}$-order ozone sensitivity coefficient to represent nonlinear response of ozone to the emission changes. BFM and HDDM estimate comparable ozone sensitivity coefficients, exhibiting similar spatial and temporal variations over the SMAduring the episode. NME (Normalized Mean Error) between BFM and HDDM for the episode average $1^{st}$- and $2^{nd}$-order ozone sensitivity coefficients to NOx and VOC emissions are less than 3% and 9%, respectively. For the daily comparison, NME for the $1^{st}$- and $2^{nd}$-order ozone sensitivity coefficients are less than 4% ($R^2$ > 0.96) and 15% ($R^2$ > 0.90), respectively. Under the emission conditions used in this study, two methods show negative episode average $1^{st}$-order ozone sensitivity coefficient to $NO_x$ emissions over the core SMA. The $2^{nd}$-order ozone sensitivity coefficient to $NO_x$ emissions leads ozone to respond muchnonlinear to the reduction in $NO_x$ emissions over Seoul. Nonlinear ozone response to reduction in VOC emissions is mitigated due to the $2^{nd}$-order ozone sensitivity coefficient which is much smaller than the $1^{st}$-order ozone sensitivity coefficient to the emissions in the magnitude.

Influence of the random fluctuation in grating period on the Coupling Coefficient of QWS-DFB Lasers (회절격자 주기의 랜덤 변이가 QWS-DFB 레이저의 정규화된 결합계수에 미치는 영향)

  • Ha, Seon-Yong;Kim, Sang-Bae
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.38 no.9
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    • pp.624-633
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    • 2001
  • Influence of the grating half-period fluctuation on the normalized coupling coefficient has been studied by an effective index transfer matrix method in quarter wavelength shifted(QWS) DFB lasers. The laser facets are assumed to be perfectly antireflection coated, and the period fluctuation is modeled by two correlated Gaussian random variables. In the presence of the random fluctuation in the grating period, effective normalized coupling coefficient is reduced because the in-phase feedback strength Is weakened. We have shown that the normalized coupling coefficient determined from the side mode spacing is less than the effective coupling coefficient, and the normalized coupling coefficient determined from the mode spacing or spontaneous emission spectrum does not properly represent the feedback strength of the grating.

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Influences of degradation in MgO protective layer and phosphors on ion-induced secondary electron emission coefficient and static margins in alternating current plasma display panels

  • Jeong, H.S.;Lim, J.E.;Park, W.B.;Jung, K.B.;Choi, E.H.
    • 한국정보디스플레이학회:학술대회논문집
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    • 2004.08a
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    • pp.518-521
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    • 2004
  • The degradation characteristics of MgO protective layer and phosphors have been investigated in terms of the ion-induced secondary electron emission coefficient ${\gamma}$ and static margin of discharge voltages, respectively, in this experiment. The ion-induced secondary electron emission coefficients ${\gamma}$ for the degraded MgO protective layer and phosphors have been studied by ${\gamma}$ -focused ion beam system. The energy of Ne+ ions used is from 80 eV to 200 eV in this experiment. The degraded MgO and phosphor layers are found to have higher ${\gamma}$ than that of normal ones without degradations or aged one. Also, the static margin of discharge voltages for test panels with degraded MgO protective layer and phosphors been found to be seriously decreased in comparison with those of normal ones without degradations.

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Soot Temperature and Concentration Measurement Using Emission/Transmission Tomography in Laminar Diffusion Flame (방사와 투과를 이용한 층류확산화염내 매연입자의 온도 및 농도 측정)

  • 송상종;박성호;김상수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.10
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    • pp.2563-2573
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    • 1993
  • The measurements of monochromatic line-of-sight flame emission and light transmission in the same path having small spatial resolution were performed in an axisymmetric laminar propane $C_{3}H_{8}$ diffusion flame. The light wavelengthes of 632 nm, 800nm, 900nm were used. From these measurements, local point soot radiances (by Kirchhoff's law) and absorption coefficients were reconstructed by tomography. Thus local point soot temperatures and concentrations were obtained. The reconstructed soot temperatures and concentrations of local points have no differences between the case of visible range (632 nm) and the case of infrared range (800 nm and 900 nm). In these ranges, the scattering coefficient is much lower than the absorption coefficient. Soot mean temperature over the path also matches well with local soot temperature in outer region of the flame. Temperature measurement by thermocouple with different bead diameters $(222{\mu}m and 308{\mu}m)$ was carried in the same flame. Rapid insertion technique was used and radiation effect was considered. Radiation correction in the sooting region was carried out and the corrected result was in good agreement with the local soot temperature.

Ultra accelerated molecular dynamics study on electronic structure and luminous efficacy of PDP protecting layer

  • Takaba, Hiromitsu;Serizawa, Kazumi;Suzuki, Ai;Tsuboi, Hideyuki;Hatakeyama, Nozomu;Endou, Akira;Kubo, Momoji;Kajiyama, Hiroshi;Miyamoto, Akira
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.169-172
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    • 2009
  • We developed ultra-accelerated quantum chemical molecular dynamics and characterization simulators for study and design of plasma display panel (PDP) related materials. By use of these simulators, realistic structure of PDP materials is drawn on the computer. Furthermore, based on the structures, various properties such as secondary electron emission coefficient are successfully evaluated. In this report, we will discuss the theoretical secondary electron emission coefficient for several protecting layer materials and the effect of surface structure on the properties based on the result of atomistic simulations.

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Effects of Intake Swirl and Combustion Parameters on the Performance and Emission in a V8 Type Turbocharged Intercooler Diesel Engine (흡기 선회유동 및 연소인자가 V8형 TCI 디젤엔진의 성능 및 배출가스특성에 미치는 영향)

  • Yoon Junkyu;Cha Kyungok
    • Transactions of the Korean Society of Automotive Engineers
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    • v.13 no.4
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    • pp.135-144
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    • 2005
  • The Effects of intake swirl and combustion parameters on the performance and emission characteristics in a V8 type turbocharged intercooler D.I. diesel engine of the displacement $16.7\iota$ were studied experimentally in this paper. Generally the swirl in the combustion process of diesel engine promotes mixing of the injection fuel and the intake air. Also, TCI diesel engine is put to practically use intercooler in order to increase boost efficiency which is cooled boost air. As a result of steady flow test, when the swirl ratio is increased, the mean flow coefficient is decreased, whereas the Gulf factor is increased. And through engine test, its can be effected to meet performance and emission by optimizing the main parameters; the swirl ratio is 2.25, compression ratio is 17.5, combustion bowl is re-entrant $8.5^{\circ}$, nozzle hole diameter is $\phi0.33^{\ast}3+\phi0.35^{\ast}2$, injection timing is BTDC $12^{\circ}CA$ and turbocharger is T02 model which are compressor 0.6A/R+46trim and turbine 1.0A/R+57trim.