• Analytical Science and Technology
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• v.18 no.5
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• pp.436-443
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• 2005

A study of physical properties and their application using K-powdered activated carbon system followed powdered carbon dispersion was carried out at laboratory. scale. Two types of K-powdered activated carbon for the dispersion have been used in this study to investigate the catalytic removal efficiency of pollutants from the wastewater. From the surface properties obtained for carbon samples treated with aqueous solutions containing potassium salts, main investigations were subjected to isotherm shape, SEM, EDX and surface functional groups. K-powdered activated carbons were dispersed to wastewater with pH variation to investigate the removal efficiency for the color, COD, T-N and T-P. From these removal results of the piggery waste using K-powdered activated carbon, satisfactory removal performance in the region of pH 6~8 was achieved. The excellent effects for the dispersion of the K-powdered activated carbon were proved by the above mentioned properties of the material for adsorption and trapping of organics, and catalytic effects.

• Journal of the Korean GEO-environmental Society
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• v.13 no.5
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• pp.51-57
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• 2012

The purpose of study is to understand the possibility of biogrout of soil induced by bacteria. Microbial Calcium Carbonate Precipitation(MCP) has been analysed using the microorganism Bacillus Pasteurii. In order to understand the biogrout of soft ground treated with microbial calcium carbonate precipitation, four types of specimens(sterilization soil, non-sterilization soil, reaction solution and microorganism solution with pre-treatment mix and reaction solution and microorganism solution with post-treatment mix) were made. Scanning Electron Microscope(SEM), EDX and X-ray diffraction(XRD) analyses were performed on the soft ground specimens. On the basis of the preliminary results, it appears that microbial treatment methods using calcium carbonate precipitation may be possible to improve property of biogrout.

• Resources Recycling
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• v.9 no.1
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• pp.52-62
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• 2000

In order to maximize the recycling of converter slag to the more valuable fields, such as high quality aggregates for construction, cement industry and flux for ion making. It will be very important to control the compositions and properties of converter slag to suit the purpose of utilizastion. In this study, converter slag (STELCO, CANADA) was mixed with 5%~30% $SiO_2$and 7% carbon, and then reduced at $1650^{\circ}C$. After the reduction was completed, the reformed slags were cooled to room temperature in the furnace. All of the slags were then characterized using SEM-EDX, XRD and chemical analysis. Also the compressive strengths and densities of the reformed slags were measured to compare with natural aggregates. XRD analysis shows that th phases of reformed slags are changed from bredigite+merwinite mixed phases of 10% $SiO_2$added reduction to akermanite phases of 20% and 30% $SiO_2$ added reduction. But the SEM-EDX analysis revealed that the phase distribution of the reformed slags was changed very sensitively and complicately depends on the change of slag compositions. And also the properties of reformed slags are changed very much depend on the phase distribution. About one third of Cadmium and on fifth of Vanadium are remained in reduction reformed converter slag. Another heavy metal elements such as cobalt, zinc, lead are removed up to more than 90-95% of original slag. The compressive strength and density of 25% $SiO_2$ added and reformed slag is very near to natural granite. This is superior more than 10% to Thyssen's $SiO_2$ added and oxidized converter slag aggregates.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.68-69
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• 2008

• Polymer(Korea)
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• v.33 no.3
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• pp.268-271
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• 2009

In this study, the distribution behaviors of the polystyrene sulfonic acid (PSSA) grafting polymer across the FEP-g-PSSA membranes prepared by a simultaneous irradiation method, were investigated by analyzing the cross-section of the membranes with a SEM-EDX instrument. The effects of irradiation conditions such as the degree of grafting, FEP film thickness, and grafting solvent on the distribution of the grafting polymer were mainly studied in this experiment. The results indicate that to obtain the evenly grafted FEP-g-PSSA membranes, the higher degree of grafting is required as the film thickness increases, and the lower dose rate are more effective than the higher dose rate at the given dose.

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.355-360
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• 2006

The Alkali-Silica Reaction(ASR) may cause a serious failure in the concrete pavements and structures. Several researches in some nations have conducted the continuous studies to prevent failure of the concrete structures by the ASR distress as well as the studies to manifest the mechanism. The researches on the ASR have not been performed affluently in Korea because the distress due to ASR has seldom been reported literarily. In this study, we tried to set up the systematic scheme practically for verifying the cause of distress due to ASR by using the visual inspections in field, the chemical method, petrographic analysis, and Electron Dispersive X-ray Spectrometer(EDX) method of Scanning Electron Microscopy(SEM) in laboratory. The chemical method, petrographic method using SEM, and X-ray method were used to verify the cause of pattern crack on the surface and internal crack in the plain concrete pavement. It can be concluded that the distress of a specific site in plain concrete pavement was mainly due to ASR. The chemical method, the petrographic method and EDX method using SEM may be the effective tools for verifying the cause of AAR distresses.

• Applied Chemistry for Engineering
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• v.8 no.1
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• pp.122-131
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• 1997

Zinc titanate sorbents for $H_2S$ removal were prepared and their reactivities were studied for high temperature desulfurization of coal gas. Sulfidation of zinc titanates by $H_2S$ sorption was conducted in a packed-bed tubular flow reactor at the temperature range of $550{\sim}750^{\circ}C$, and the results reveal that $650^{\circ}C$ was the optimal sulfidation temperature with respect to desulfurization efficiency and zinc loss. The structural change of sorbent particle was investigated by SEM analysis for the forbents sulfided at $650^{\circ}C$ and subsequently regenerated at $750^{\circ}C$. The stability of desulfurization capability as well as the mechanical stability of the zinc titanates was studied by means of the successive cycles of sulfidation-regeneration of sorbents, and the sorbent samples taken after the 10th cycle were characterized using BET, XRD, and SEM/EDX analyses. Zinc titanate sorbents exhibited nearly constant desulfurization capability in the successive cycle operation.

• Analytical Science and Technology
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• v.19 no.6
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• pp.460-467
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• 2006

Carbon-coated $TiO_2$ was prepared by $CCl_4$ solvent mixing method with different heat treatment temperature (HTT). Since the carbon layers derived from pitch on the $TiO_2$ particles were porous, the carbon-coated $TiO_2$ sample series showed a good adsorptivity and photo decomposition activity. The BET surface area was decreased by the increasing of the heat treatment temperature. The SEM results present to the characterization of surface texture on the carbon-coated $TiO_2$ sample and carbon distributions on the surfaces for all the materials used. The main elements of C, O and Ti were shown from EDX spectra. And the quantity of these elements is very rich in the samples. From XRD data, the pristine anatase peaks were observed in the X-ray diffraction patterns for the carbon-coated $TiO_2$ at the different HTTs. However, the rutile peaks were observed for the carbon-coated $TiO_2$ at HTT of 1073 K and 1123 K. Finally, the excellent photocatalytic activity of carbon-coated $TiO_2$ with UV-vis spectra between absorbance and time could be attributed to the homogeneous coated carbon on the external surface and structural phase transform, and the photocatalytic activity was decreased by the increasing of the HTT.

• Proceedings of the International Microelectronics And Packaging Society Conference
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• 2001.07a
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• pp.127-133
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• 2001

Package reliability test was conducted to investigate the effect of solder composition on ball fatigue strength. The specimens are first assembled using eutectic Composition S $n_{62}$P $b_{36}$A $g_2$, S $n_{63}$P $b_{34.5}$A $g_2$S $b_{0.5}$ solder and Pre-conditioned at MRT Lv 2a and then conducted under Temperature Cycle test(TC). For each case, the ball shear strength is obtained and micro structure photos are taken. SEM and EDX are used to analyze failure mechanism. The degradation of shear strength of solder balls after reliability test is discussed.d.

• Mass Spectrometry Letters
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• v.7 no.2
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• pp.41-44
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• 2016

Secondary ion mass spectrometry (SIMS) is a promising tool to measure isotope ratios of individual uranium particles in environmental samples for nuclear safeguards. However, the analysis requires prior identification of a small number of uranium particles that coexist with a large number of other particles without uranium. In the present study, this identification was performed by scanning electron microscopy - energy dispersive X-ray analysis with automated particle search mode. The analytical results for an environmental sample taken at a nuclear facility indicated that the observation of backscattered electron images with × 1000 magnification was appropriate to efficiently identify uranium particles. Lower magnification (less than × 500) made it difficult to detect smaller particles of approximately 1 μm diameter. After identification, each particle was manipulated and transferred for subsequent isotope ratio analysis by SIMS. Consequently, the isotope ratios of individual uranium particles were successfully determined without any molecular ion interference. It was demonstrated that the proposed technique provides a powerful tool to measure individual particles not only for nuclear safeguards but also for environmental sciences.