• Journal of Korean Society for Atmospheric Environment
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• v.19 no.6
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• pp.701-717
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• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• Journal of the Korea Convergence Society
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• v.11 no.8
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• pp.159-163
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• 2020

In this study, the flow analyses around according to the existence or non- existence of the trailer's deflector and the shapes were carried out. In the absence of a deflector, the kinetic energy of the turbulence behind the container also generates higher kinetic energy in a wider area than in the presence of a deflector, which adversely affects the vehicle's driving performance. As a trailer's wind deflector-free model has unstable flow rates around the trailer and high kinetic energy of turbulence than a model with a deflector, it can be thought that the increase of fuel economy can be expected by installing a deflector in the trailer. By applying the study result on flow analysis near trailer due to shape of wind deflector, this study is seen to be suitable for the aesthetic convergence.

• Economic and Environmental Geology
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• v.30 no.5
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• pp.443-450
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• 1997

The main purpose of this study is to investigate mineralogical and chemical changes during natural weathering, and assess the mobility of major and trace elements. Yongwol power plant utilize anthracite coal which is mainly composed of illite, kaolinite, pyrophyllite and quartz in mineralogy. Coal and coal-derived fly ash samples were sampled by the electrostatic precipitator in Yongwol coal-fired power plant in Korea. Short term weathered fly ash were also collected in ash disposal mound, and two profile soil samples were taken from an ash near the power plant. Amorphous materials are the main component of the fly ash, and mullite, quartz, magnetite and heamatite are present in all coal-derived fly ash. In chemistry, Si and Al are the most abundant elements of the total content. The ash samples were fractionated into upper $90{\mu}m$ and under $45{\mu}m$ size. Finer particles show higher concentrations in metal contents including Co, Cr, Cu, Ni, V, Zn and Pb. Concentration of Zn and Pb are nearly 4 times higher concentration in the finer particles. For the profile samples, the concentrations of $SiO_2$, $Na_2O$, MgO and $K_2O$ generally show increasing trends with depth, whereas those of $Fe_2O_3$ and $TiO_2$ appear to decrease with depth. Content of MnO does not show any specific depth trend. For the trace elements, Co, Cu, Ni and V show increasing concentrations with depth.

• Journal of Korean Society for Atmospheric Environment
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• v.16 no.5
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• pp.469-476
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• 2000

This study was performed to understand the behavior and source characteristics of particulate trace metals in Daegu area. To do this, total of 84 samples had been collected from January to December 1999. TSP (total suspended particulate matter) and PM-10(particulate matter with aerodynamic diameters less 10${\mu}{\textrm}{m}$) were collected by filters on portable air sampler, and in TSP and PM-10 were analyzed by ICP(Inductively Coupled Plasma Spectrometer) after preliminary treatment. The results were follow as: first, annul means of TSP and PM-10 concentration were 123 and 69$\mu\textrm{g}$/㎤ respectively. The concentration of TSP adn PM-10 were highest in winter season compared to other seasons. Second, the concentration of Al, Fe, Mn were higher in TSP than in PM-10, indicating that these metals are generally associate with natural contributions. Third, a hierarchical clustering technique was used to group 9 metals. The results from the cluster analysis of TSP and PM-10 shows a similar clustering pattern : Fe, Al in a group and the rest of the metals such as Ni, Cr, As, Mn, Cd, Pb, Zn in the other group. One group of metal such as Fe, Al is associated with natural sources such as soil and dust. The other is closely related to urban anthropogenic sources such as fuel combustion, incineration, and refuse burning, Finally, using Al as a reference element, enrichment factors were used for identifying the major particulate contributors. The enrichment factors of Al. Fe<10 (standard value of enrichment factor) were considered to have a significant dust and soil source and termed nonenriched. Ni, Cr, As, Mn, Cd, Pb, Zn》10 is enriched and has a significant which is contributed by athropogenic sources.

• The Journal of the Korea Contents Association
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• v.17 no.3
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• pp.666-674
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• 2017

Today, the term of fusion, such as technology convergence and industrial convergence, is emerging as one of the most important trends in our society. The purpose of this study is to analyze the convergence coefficient of each industry using patent data and to analyze the convergence phenomenon in industry based on convergence coefficient. To do this, 2011-2015 Korean patent data were utilized. The research findings revealed that the ICC by industry was the highest in order of man-made fibres, paints/varnishes, petroleum products/nuclear fuel and other chemicals. Also, according to the inter-industry convergence matrix, the number of convergence patents was the greatest in order of office machinery and computers, special purpose machinery industries and Measuring instruments. Added same analysis was conducted through Industry with high number of patents. As a result, the convergence has been actively carried out in the fields of optical instruments, Basic chemical, Fabricated metal products, Measuring instruments and special purpose machine manufacturing industries.

• Journal of Powder Materials
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• v.21 no.2
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• pp.119-123
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• 2014

Pt has been widely used as catalyst for fuel cell and exhausted gas clean systems due to its high catalytic activity. Recently, there have been researches on fabricating composite materials of Pt as a method of reducing the amount of Pt due to its high price. One of the approaches for saving Pt used as catalyst is a core shell structure consisting of Pt layer on the core of the non-noble metal. In this study, the synthesis of Pt shell was conducted on the surface of $TiO_2$ particle, a non-noble material, by applying ultraviolet (UV) irradiation. Anatase $TiO_2$ particles with the average size of 20~30 nm were immersed in the ethanol dissolved with Pt precursor of $H_2PtCl_6{\cdot}6H_2O$ and exposed to UV irradiation with the wavelength of 365 nm. It was confirmed that Pt nano-particles were formed on the surface of $TiO_2$ particles by photochemical reduction of Pt ion from the solution. The morphology of the synthesized Pt@$TiO_2$ nano-composite was examined by TEM (Transmission Electron Microscopy).

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.10 no.3
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• pp.171-188
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• 2012

A GoldSim template program for a safety assessment of a hybrid-typed repository system, called "A-KRS," in which two kinds of pyro-processed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyro-processing of PWR nuclear spent fuels are disposed of, has been developed. This program is ready both for a deterministic and probabilistic total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios. The A-KRS has been deterministically assessed with 5 various normal and abnormal scenarios associated with nuclide release and transport in and around the repository. Dose exposure rates to the farming exposure group have been evaluated in accordance with all the scenarios and then compared among other.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.17 no.4
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• pp.429-435
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• 2019

Decontamination wastewater generated from the HyBRID decontamination process of the primary system in a nuclear power plant contains impurities such as sulfate ions, metal ions containing radioactive nuclides, and hydrazine (carcinogenic agent). For this reason, it is necessary to develop a technology to remove these impurities from the wastewater to a safe level. In this study, it has been conducted to remove the impurities using a decontamination wastewater surrogate, and a treatment process of the HyBRID decontamination wastewater has been established. The performance and applicability of the treatment process have been verified through 1 L scale of replicates and a pilot scale (300 L/batch) test.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.16 no.3
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• pp.309-313
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• 2018

In this study, we prepared Li-K-Cd alloy, which meets the requirement of eutectic ratio of Li:K, to maintain the operating temperature of the drawdown process at $500^{\circ}C$ and to achieve the reuse of LiCl-KCl molten salt. The prepared Li-K-Cd alloys were added to LiCl-KCl salt bearing U and Nd at $500^{\circ}C$ to investigate the removal of $UCl_3$ in the salt. The reduction of $UCl_3$ in the salt was examined by measuring the OCP value of salt and analyzing the salt composition by ICP-OES. Reduction was also visually confirmed by change of salt color from dark purple to white. The experimental results reveal that the prepared Li-K-Cd alloy has reductive extractability for $UCl_3$ in salt. By improving the preparation method, the Li-K-Cd alloy can be applied to the drawdown process.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.31 no.9
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• pp.110-120
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• 2003

As the wooden aircraft in the early times has no way to let lightning flow when lighting flash attaches during flight, the aircraft got damage, or caught fire. Though all metal airplane was developed with an advent of aluminum, a lightning accident still occurred including a fire of a fuel tanks. Eventually, NACA declared problems in 1938, and an artificial lightning test began. III succession, FAA established Airworthiness Requirements for certification. The FAA committed test measures study for the protection of an airplane from lightning to SAE. SAE presented the test current and voltage waveforms that simulating natural lightning, and it is utilized on lightning protection certification of an airplane by public. A lightning effects of an airplane through an analysis of lightning mechanism was made in this technical note. Especially, lightning direct effects on aircraft are analyzed and lightning strike zones are described.