• Journal of the Korean Vacuum Society
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• v.17 no.3
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• pp.247-252
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• 2008

By using the transmission anode x-ray tube developed to apply to the hand-held XRF equipment, we carried out XRF experiment and evaluated the influences of the x-ray tube on XRF spectra. XRF data, which is measured using the W-target and Rh-target tube, were good agreements with the known results. FWHM of Fe $K_{\alpha}$-line measured by W-target tube with the 35 kV-tube voltage and the $40{\mu}A$-tube current was 180 eV. This result reveals that our XRF equipment using the transmission anode x-ray tube is enough for a qualitative analysis of materials. By comparison XRF data with the integrated intensity of x-ray tube, it was confirmed that Rh-target tube is better than W-target tube for application to the hand-held XRF equipment.

• Economic and Environmental Geology
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• v.17 no.4
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• pp.315-320
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• 1984

The newly discovered minerals found during 30 years have been discovered with election microprobe analysis, and several other new minerals have been described largely on the basis of probe analysis. Widely used types of instrument are the wavelength dispersive spectrometer (WDS) and the energy dispersive Spectrometer (EDS), with emitted X-ray dispersed by a curved crystal that is arranged to satisfy the Bragg equation ($n{\lambda}=2dsin{\theta}$). Atomic Nos of Z 4 to 92 can be analyzed quantitatively if they present in amount exceeding 50~100ppm. The application of the microprobe in mineralogical and geological research is quantitative chemical analysis of grains as small as a few microns in diameter, individual grains in a rock or can be analyzed in thin section and polished section, analysis can be made comparatively short time, methods in non-destructure, to photographical and crystallographical information. This paper was written in order to document data evaluation procedure for quantitative energy dispersive election probe analysis.

• Journal of Hydrogen and New Energy
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• v.4 no.1
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• pp.31-39
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• 1993

In order to improve the hydrogen storage capacity and the activation property of the $MmNi_{4.5}Al_{0.5}$ alloy, the multiphase alloy system are prepared by adding the excess Zr in $MmNi_{4.5}Al_{0.5}$ alloy. It is estimated from the X-ray diffraction pattern and the energy dispersive X-ray analysis that the 2nd phases in $MmNi_{4.5}Al_{0.5}Zr_x$ alloys are $ZrNi_3$, ${\beta}$-Zr. Their morphology is also examined by the scanning electron microscope, and it shows the needle-like precipitation. As the Zr contents increase, the activation time and the plateau pressure decrease, sloping of the plateau pressure increase. Amount of the 2nd phases increase with Zr contents in $MmNi_44.5Al_{0.5}Zr_x$ alloys. The $MmNi_44.5Al_{0.5}Zr_{0.05}$ alloy, which shows the maximum storage capacity and the strong resistance to intrinsic degradation, is considered as a proper alloy for hydrogen storage.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.1
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• pp.20-26
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• 2015

Objectives: To evaluate the biodurability of Korean Chrysotile(KC), the changes in fibers numbers and changes in the element composition of fibers from the lung of Sprague-Dawley rats instilled KC(average size $4.74{\mu}m$, $59,043{\times}10^6$ fibers/mg) was estimated. Methods: Rats were administered 1 mg KC(low group) or 2 mg KC(high group) by a single intratracheal instillation. At each time point(5 days, 5 weeks, 10 weeks), the numbers of KC fibers and the changes of element composition(atomic %) of KC fibers from the lung of the rats were analyzed with transmission electron microscope equipped with energy dispersive X-ray spectrometer. Results: Over time, the number of fibers within the lungs of animals were reduced. The average length of the low and high group is significantly reduced from 5 days after administration. Over time, the fiber ratio of at least $5{\mu}m$ remaining in the lung tissue of the low concentration group was up but the high group was reduced. From day 5 after administration, the composition ratio(Mg) was significantly decreased in all groups. Conclusions: Size and composition of Korean Chrysotile in the lung tissue of rats was changed from 5 days.

• Journal of Environmental Science International
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• v.5 no.3
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• pp.317-327
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• 1996

This study was performed to develop the biological treatment technology of wastewater polluted with heavy metals. Zinc-tolerant microorganism, such as Pseudomonas chlororaphis which possessed the ability to accumulate zinc, was isolated from industrial wastewaters polluted with various heavy metals. The characteristics of zinc accumulation in the cells, recovery of the zinc from the cells accumulating zinc, were investigated. Removal rate of zinc from the solution containing 100 mall of Zinc by zinc-tolerant microorganism was more than 90% at 48 hours after inoiulation of the microorganisms. A large number of the electron-dense granules were found mainly on thIn cell wall and membrane fractions, when determined by transmission electron microscope. Energy dispersive X- ray spectroscopy revealed that the electron-dense granules were zinc complex with the substances binding Heavy metals. The zinc accumulated into cells was not desorbed by distilled water, but more than 80% of the zinc accumulated was desorbed by 0.1M-EDTA. The residues of the cells after combustion at 55$0^{\circ}C$ amounted to about 21% of the dry weight of the cells. EDS analysis showed that the residues were comparatively pure zinc compounds containing more than 79% of zinc.

• Geomechanics and Engineering
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• v.7 no.6
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• pp.649-663
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• 2014

In past few years, the use of bacterial calcium carbonate precipitation (biocementation) has become popular as a ground improvement technique for sandy soil. However, this technique was not applied to organic soil. This study focused on bacterial calcium carbonate precipitation and its effect on permeability in organic soil. A special injection system was prepared for inducing bacterial solution to the samples. The bacterial solution supplied to the samples by gravity for 4 days in specific molds designed for this work. Calcite precipitation was observed by monitoring pH value and measuring amount of calcium carbonate. Change in the permeability was measured before and after biocementation. The test results showed that the pH values indicates that the treatment medium is appropriate for calcite precipitation, and amount of precipitated calcium carbonate in organic soil increased about 20% from untreated one. It was also found that the biocementation can be considered as an effective method for reducing permeability of organic soil. The results were supported by Scanning electron microscopy (SEM) analysis and energy-dispersive x-ray (EDX) analysis.

• Korean Journal of Materials Research
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• v.17 no.8
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• pp.408-413
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• 2007

Process of the hydroxyapapite(HA) precipitation on bioactive titanium metal prepared by NaOH in a modified-simulated body fluid(mSBF) was investigated by high resolution transmission electron microscope (HRTEM) attached with energy dispersive X-ray spectrometer(EDX). The amorphous titanate phase on titanium surface is form by NaOH treatment and an amorphous titanate incorporated calcium and phosphate ions in the liquid to form an amorphous calcium phosphate. With increasing of soaking time in the liquid, the HA particles are observed in amorphous calcium phosphate phase with a Ca/P atomic ratio of I.30. The octacalcium phosphate (OCP) structure is not detected in HRTEM image and electron diffraction pattern. After a long soaking time, the HA particles grow as needle-like shape on titanium surface and a large particle-like aggregates of needle-like substance were observed to form on titanium surface within needle-like shape. A long axis of needle parallels to c-direction of the hexagonal HA structure.

• Journal of the Korea Organic Resources Recycling Association
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• v.19 no.1
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• pp.79-85
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• 2011

A study on characteristics for removal of arsenic ion using phosphorylated pine needles was performed. The surface condition of phosphorylated pine needles was confirmed by FT-IR, SEM(Scanning Electron Microscopy) and EDX(Energy Dispersive X-ray). The removal rate of arsenic ion was the highest as about 98% at pH 7. Most absorption for arsenic ion was also completed within 30min and decreased with time and pH of arsenic solution from 6.5 to 2.4.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.34 no.5
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• pp.364-370
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• 2021

In this study, the dielectric properties of flame retardant silicone rubber mixed with the amount of silica 50~65 phr were measured at frequencies ranging from 1 to 2.7 MHz and temperature ranges from 30℃ to 160℃. The permittivity decreased with higher frequencies and higher temperatures, and tanδ are thought to have decreased due to the increased heat oxidation of the methyl group bound to Si, which increased the hardness of silicone rubber. FT-IR analysis of specimen mixed with SiO₂ of 50~65 phr showed oscillations of OH groups bound to SiO₂ between wavenumber 3,600 and 3,300. As a result of analyzing surface components by Energy Dispersive X-ray (EDX) on all specimens mixed with SiO₂ of 50 to 65 phr, all specimens contained Si, and the analysis by field emission scanning electron (FE-SEM) confirmed that about 1~5 ㎛ particles were distributed regularly on the surface of the specimens.

• Journal of the Semiconductor & Display Technology
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• v.21 no.4
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• pp.99-105
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• 2022

Public attention to the indoor environment of underground subway stations, which is a representative multi-use facility, has been increasing along with the increase in indoor activities. In underground stations, fine iron oxide, which affects the health of users, is generated because of the friction between wheels and rails. Among particulate pollutant reduction technologies, plants have been considered as a non-chemical air purification method, and their effects in reducing certain chemical species have been identified in previous studies. The present study aimed to derive the total quantitative and qualitative reduction effects of a bio-filter system comprising air purifying plants, installed in an underground subway station. The experiment proceeded in two ways. First, PM(particulate matter) reduction effect by vegetation biofilter was monitored with the IAQ(indoor air quality) station. In addition, chemical speciation analysis conducted on the samples collected from the experimental and control areas where plants and irrigation using SEM-EDS(scanning electron microscopy-energy dispersive X-ray spectroscopy). This study confirmed the effect of the vegetation bio-filter system in reducing the accumulation of particulate pollutants and transition and other metals that are harmful to the human body.