• Advances in environmental research
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• 제9권2호
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• pp.97-107
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• 2020

The indiscriminate growth in global population poses a threat to the world in handling and disposal of Municipal solid waste. Rapid urban growth increases the production, consumption and generation of Municipal solid waste which leads to a drastic change in the environment. The methane produced from the Municipal Solid waste accounts for up to 11% global anthropogenic emissions, which is a major cause for global warming. This study reports the methane emission estimation using IPCC default, TNO, LandGEM, EPER and close flux chamber from open dump yards at Perungudi and Kodungaiyur in Chennai, India. The result reveals that the methane emission using close flux chamber was in the range of 8.8 Gg/yr-11.3 Gg/yr and 6.1Gg/yr to 9.1 Gg/yr at Kodungaiyur and Perungudi dump yard respectively. The per capita waste generation was estimated based on waste generation and population. The waste generation potential was projected using linear regression model for the period 2017-2050. The trend of CH₄ emission in the actual field measurement were increased every year, similarly the emission trend also increased in IPCC default method (mass balance approach), EPER Germany (zero order decay model) where as TNO and Land GEM (first order decay model) were decreased. The present study reveals that Kodungaiyur dump yard is more vulnerable to methane emission compared to Perungudi dump yard and has more potential in waste to energy conversion mechanisms than compare to Perungudi dump yard.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 추계학술대회 논문집 전기물성,응용부문
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• pp.204-206
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• 2003

Electron beam generator of cold cathode type has been developed for industrial application, for example, waste water cleaning, flue gas cleaning, and pasteurization etc. The operational principle is based on the emission of secondary electrons from cold cathode when ions in the plasma hit the cathode, which are accelerated toward exit window by the gradient of an electric potential. The characteristics of secondary electron emission are studied by comparing total cathode current with ion current.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2000년도 제1회 학술대회 논문집
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• pp.129-130
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• 2000

The emission color stability of poly(fluorene) derivatives upon thermal annealing or passage of current in an electroluminescent device is affected by the structure of the main chain polymer unit and particularly by the polymer chain end substituents. Proper attention to these features leads to colorfast blue emission in both photo- and electoluminescence. Furthermore, the spectral emission characteristics can be tuned by the incorporation of various comonomers. Preliminary single layer device studies validate the potential utility of poly(fluorene) homo and copolymers for OLED applications.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권1호
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• pp.764-767
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• 2007

We investigated the field emission of single carbon nanotube including the anode effect by calculating the tunneling probability of an electron. The experimental results from this study were in agreement with our theoretical calculations. The constant enhancement factor was calculated using an approximation of the potential barrier.

• 천문학회보
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• 제42권2호
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• pp.81.2-81.2
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• 2017

Polarized mid-infrared emission from polycyclic aromatic hydrocarbons (PAHs) can provide a crucial test of basic physics of alignment of nanoparticles and opens a potential new window into studying magnetic fields. In this talk, I will present a new model of polarized PAH emission that takes into account the effect of PAH alignment with the magnetic field due to resonance paramagnetic relaxation. I will then present our predictions for the polarization level of the strong PAH emission features from the interstellar medium. I will present the first detection of polarization of PAH emission at 11.3micron which is consistent with our theoretical prediction. Finally, I will discuss important implications of this work for tracing magnetic fields via mid-IR PAH features and for constraining the polarization of anomalous microwave emission that is useful for the quest of CMB B-modes.

• 한국자동차공학회논문집
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• 제6권1호
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• pp.108-121
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• 1998

Using gas chromatography, the light hydrocarbon emissions were analyzed from SI engine fueled with methane and liquified petroleum gas(LPG), and the effects of fuel and engine operating condition were discussed. For this purpose, 14 species of light hydrocarbon including 1, 3-butadiene were separated, calibrated with standard gas, and measured from undiluted emissions. The brake specific hydrocarbon emission(BSHC) and ozone forming potential(BSO)3 were calculated and discussed with the changes of fuel, engine speed, load, fuel/air equivalence ratio, coolant temperature, and spark timing. As a result, exhaust emission was composed of mainly fuel composed of mainly fuel comp- onent and other olefin components of similar carbon number. The olefin components such as ethylene and propylene determine most of the ozone forming potential. The fraction of fuel component in total hydrocarbon emission was bigger with methane fuel than with LPG fuel. Also fuel fraction increased at high speed or high speed or high temperature of exhaust gas, and to lesser extent with high coolant temperature and retarded spark. However, the effect of equivalence ratio had different tendency according to fuels.

• JSTS:Journal of Semiconductor Technology and Science
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• 제13권4호
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• pp.395-401
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• 2013

In-situ optical emission spectroscopy (OES) is employed for leak detection in plasma etching system. A misprocessing is reported for significantly reduced silicon etch rate with chlorine gas, and OES is used as a supplementary sensor to analyze the gas phase species that reside in the process chamber. Potential cause of misprocessing reaches to chamber O-ring wear out, MFC leaks, and/or leak at gas delivery line, and experiments are performed to funnel down the potential of the cause. While monitoring the plasma chemistry of the process chamber using OES, the emission trace for nitrogen species is observed at the chlorine gas supply. No trace of nitrogen species is found in other than chlorine gas supply, and we found that the amount of chlorine gas is slightly fluctuating. We successfully found the root cause of the reported misprocessing which may jeopardize the quality of thin film processing. Based on a quantitative analysis of the amount of nitrogen observed in the chamber, we conclude that the source of the leak is the fitting of the chlorine mass flow controller with the amount of around 2-5 sccm.

• 한국연소학회:학술대회논문집
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• 한국연소학회 2013년도 제46회 KOSCO SYMPOSIUM 초록집
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• pp.33-35
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• 2013

The present work is an experimental investigation on potential operating range using directly injected gasoline fuel in a single-cylinder compression ignition (CI) engine. The objectives of present study were to apply auto-ignited combustion to gasoline fuel and to evaluate potential operating range. In order to auto-ignite gasoline fuel in CI engine, the fuel direct-injection system and the intake air system were modified that a flow rate and temperature of intake air were regulated. The heat-release rate (HRR), net indicated mean effective pressure (IMEP), start of combustion (SOC), and combustion duration were derived from in-cylinder pressure data in a test engine, which has 373.33cc displacement volume and 17.8 compression ratio. The exhaust emission characteristics were obtained emission gas analyzer and smoke meter on the exhaust line system.

• 한국염색가공학회지
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• 제25권3호
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• pp.159-164
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• 2013

Pyrene based molecule has been synthesized through the reaction of pyrene-1-carboxaldehyde and 4- phenylthiosemicarbazide in this research. The pyrene based molecule showed specific optical properties such as absorption and emission changes after mixing with fluoride in DMSO. The phenomenon is induced by the interaction of the molecule and fluoride. This interaction may affect to electron distributions and potential energy levels. In this regard, synthesized pyrene based molecule has been investigated for its electron distributions and HOMO/LUMO energy levels depending on interaction with fluoride. The absorption measurement, cyclicvoltammograms and computational method were investigated to calculate and compare energy potential levels.

• 대기
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• 제24권2호
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• pp.245-251
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• 2014

Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.