• Journal of the Korean Chemical Society
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• v.28 no.5
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• pp.293-301
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• 1984

-ray fluorescence analysis of $Ta_2O_5$, $Nb_2O_5$ and $ZrO_2$ in tin-slag samples using the simple dilution method was studied. The method is to correct mathematically the calibration curve to the linear line by the dilution. One synthesized standard having similar composition to the sample and tin slag samples were diluted with anhydrous $Li_2B_4O_7$ at the level of 1%, 2% and 3% of the sample content respectively. The diluted samples were fused at $1150^{\circ}C$ for 30 minutes and these glass beads were finely ground and pelletized. Measuring the X-ray intensities with these pellets, analytical results were calculated by the equation derived from J. Scherman's equation for the characteristic X-ray intensity of an element. Analytical results agreed with the reference values obtained by the standard calibration method within allowable error range and were reproducible.

• Journal of Nuclear Fuel Cycle and Waste Technology(JNFCWT)
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• v.6 no.3
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• pp.189-203
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• 2008

The physical and chemical properties of radioactive waste drums, which have been temporarily stored on site, should be characterized before their shipment to a disposal facility in order to prove that the properties meet the acceptance guideline. The investigation of NDT(Nondestructive Test) method was figured out that the contents in drum, the quantitative analysis of free standing water and void fraction can be examined with X-ray NDT techniques. This paper describes the characteristics of X-ray NDT such as its principles, the considerations for selection of X-ray system, etc. And then, the waste drum characteristics such as drum type and dimension, contents in drum, etc. were examined, which are necessary to estimate the optimal X-ray energy for NDT of a drum. The estimation results were that: $(R)\acute{A}$ the proper X-ray energy is under 3 MeV to test the drums of 320 ${\beta}\S$ and less; $(R)\ddot{E}$ both X-ray systems of 450 keV and/or 3 MeV might be needed considering the economical efficiency and the realization. The number of drums that can be tested with 450 keV and 3 MeV X-ray system was figured out as 42,327 and 18,105 drums (based on storage of 2006. 12), respectively. Four testing scenarios were derived considering equipment procurement method, outsourcing or not, etc. The economical and feasibility assessment for the scenarios was resulted in that an optimal scenario is dependent on the acceptance guide line, the waste generator's policy on the waste treatment and the delivery to a disposal facility, etc. For example, it might be desirable that a waste generator purchases two 450 keV mobile system to examine the drums containing low density waste, and that outsourcing examination for the high density drums, if all NDT items such as quantitative analysis for 'free standing water' and 'void fraction', and confirmation of contents in drum have to be characterized. However, one 450 keV mobile system seems to be required to test only the contents in 13,000 drums per year.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.3
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• pp.297-302
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• 2016

In this study, we prepared liquid crystal emulsions composed of $C_{12-20}$ alkyl glucoside, $C_{14-22}$ alcohol, and behenyl alcohol and performed structure analysis using various analytical equipment. First, as an important characteristic of liquid crystal emulsions, maltese cross patterns and multi-layer structure were observed by a polarized microscope and cryo-SEM. Also, formation of liquid crystal phase was confirmed by DSC and multi-layer lamellar structure having an interlayer spacing approximately $305{\AA}$ was confirmed by small angle x-ray scattering (SAXS). The alkyl chain arrangement formed orthorhombic structure of a lamellar structure of the liquid crystal emulsion was confirmed by wide angle x-ray scattering (WAXS). These results suggest that information on the various physical properties obtained through the research of liquid crystal emulsion structure is expected to be widely used in cosmetics development in the future.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.05a
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• pp.113-113
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• 2015

본 연구에서는 thermal evaporation법을 이용하여 제작한 CdTe 후막의 미세구조, 전기적 특성 및 X-선 조사에 따른 특성을 비교분석하였다. 기판온도를 $370{\sim}450^{\circ}C$로 변화시키며 증착하였으며, CdCl2 첨가에 따른 미세구조 변화를 관찰하였다. CdTe 막의 상 하부에 전극을 형성하여 I-V 특성을 평가하고, 실제 X-ray를 샘플에 조사하여 sensitivity를 측정하였다. 박막형성 초기에는 기판온도가 증가함에 따라 grain size가 증가하였지만, grain uniformity는 감소하였다. X-ray 특성향상을 위해서는 grain size와 uniformity 모두 중요한 인자이기 때문에 uniformity 향상을 위해 Cl을 첨가하였다. 미량의 Cl 첨가에서는 큰 변화를 보이지 않았지만 더 많은 양의 Cl 첨가 시, grain size 와 uniformity 모두 증가되는 것을 확인하였으며, 그에 따라 I-V, X-ray 조사 특성 모두 개선되는 것을 확인할 수 있었다.

• Journal of the Korean Magnetics Society
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• v.25 no.2
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• pp.52-57
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• 2015

The focal spot of electron beam depending on the anode angle in the structure and major parts of the X-ray tube was investigated by the OPERA-3D/SCALAR simulation program. The simulation worked on four spaces with with two spaces, including anode and cathode of X-ray tube, by applying the finite element method analysis. The analytical model and dimension for the emission orbit of thermal electrons made from one filament of the focused X-ray cathode is affected to the penumbra of detector for the X-ray depending on any real focal spot size. The model shape of focusing cap and focusing tube with an anode target angle and a cathode filament is analyzed by the current density distribution of thermal electrons. The focusing width of thermal electrons for the X-ray tube depended on the anode angle (${\theta}$). The focusing value of electron beams at a region of anode angle having $10^{\circ}{\sim}17^{\circ}$ maintained to below value of $70{\mu}m$. The minimum focal size of the electron beam was $40{\mu}m$ at an anode angle of $15^{\circ}$. The focused X-ray tube of many variables depended on the thermionic emission of hot electrons from the target trajectory. The focusing tube will contribute to the real design of X-ray for the development of future diagnosis medical device.

• The Journal of the Petrological Society of Korea
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• v.19 no.4
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• pp.245-254
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• 2010

Technology of surface investigation using X-ray is one of widely used technology nowadays. This technique has been numerously used for planetary surface investigations for both orbital and rover scientific instruments. Korea has a plan to send an orbiter and lander to the Moon by the early 2020s. Therefore, the time has come for Korean researchers to develop major scientific instruments and start to do research on basic research for the Moon. Because of this situation, we firstly investigate X-ray technology, which is essential as one of core techniques of planetary remote sensing from the orbit and ground. This paper presents the current status of planetary exploration using X-ray techniques and new development of worldwide X-ray technology which could be adapted for prospective planetary missions.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.08a
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• pp.238-238
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• 2013

사파이어 단결정은 광학 투명도, 물리적 강도, 충격 저항, 마모 부식, 높은 압력 및 온도 내구성, 생체 호환성 등 다양한 특성을 가지고 있어 다양한 분야에서 사용되고 있으며, 특히 최근에는 백색 또는 청색 LED 소자 분야에서 기판으로 주로 활용되고 있다. 이러한 사파이어 단결정 기판은 공정에서 결정 성장 조건 및 기계적 연마 등의 다양한 요인으로 결정학적 결함이 발생한다. 이러한 결정학적 결함을 제어함으로서 좋은 품질의 단결정 기판을 생산할 수 있다. 이에 따라 각종 결함 제어를 위해서 X-선, EPD, 레이저 편광법 등 다양한 방법으로 결함들을 측정하고 있다. 그 중에서도 X-선 토포그래피는 시료를 비파괴적인 방법으로 단결정의 결함 밀도와 유형 등을 파악하는데 매우 유용한 측정법이며, Lang 토포그래피로 대표되는 X-선 회절 투과법은 기판과 같은 대구경의 시료를 우수한 분해능으로 내부 결함까지 관찰할 수 있는 장점을 지니고 있다. 본 연구에서는 대구경 사파이어 단결정 기판에 내재하는 결정 결함을 확인 및 분석하기 위해 X-선 Lang 토포그래피(X-ray Lang Topography) 장비를 구축하였다. 그리고 4, 6인치 c-면 사파이어 단결정 기판의 (110), (102) 회절면의 X-선 토포그래피 측정을 통해 전위(dislocation), 스크래치(scratch), 표면데미지(surface damage), 트윈(twin), 잔류 응력(strain) 등의 결함의 유형을 식별 및 분석하였으며, 각각의 결함들의 토포그래피 이미지 형성 메커니즘에 대해 분석하였다. 이를 통해 X-선 Lang 토포그래피(X-ray Lang Topography) 장비가 대구경 사파이어 단결정 기판의 결정 결함 평가에 폭넓은 활용이 가능할 것으로 예상된다.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.4
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• pp.415-425
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• 2003

A single particle analysis, called low-Z electron probe X-ray microanalysis was applied to characterize the atmospheric aerosols collected during Asian Dust storm events in the year of 2000 and 2001. Most frequently encountered chemical species were the soil-originated species such as aluminosilicates, silicon dioxide, and calcium carbonate. Also various species such as carbon -rich, organics, sea salts, and some reacted calcium carbonate were identified. The observation of internally mixed particles oi calcium carbonate, calcium nitrate and/or calcium sulfate shows the occurrence of the heterogeneous reaction between Asian Dust particles and NO$_{x}$ and/or SO$_{x}$ species in the atmosphere.ere.

• Journal of Astronomy and Space Sciences
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• v.15 no.2
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• pp.373-389
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• 1998

The test result of the X-ray observation system is presented which have been developed at Korea Astronomy Observatory for 3 years(1995 -1997). The instrument, which is composed of detector and signal processing parts, is designed for the future observations of compact X-ray sources. The performance of the instrument was tested by mounting on the two-stage Korean Sounding Rocket, which was launched from Taean rocket flight center on June 11 at 10:00 KST 1998. Telemetry data was received from individual parts of the instrument for 32 and 55.7 sec, respectively, since the launch of the rocket. In this paper, the result of the data analysis based on the received telemetry data and discussion about the performance of the instrument is reported.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.5-11
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• 2010

In this paper, we are suggested development of dual-mode detector for dual-energy digital radiography. Design of dual-energy radiography module for commercial BIS (Baggage Inspection System) is used in the spectrum of the X-ray generator and detector for dual-mode features and radiological characteristics were analyzed. BIS suggestl on the image detector module being used to target X-ray tube to simulate X-ray spectrum and simulated spectrum to offer through the new radiographic characteristics of the detector modules were investigated. Using X-ray experiments with an increase in the thickness of the copper filter low energy detector (LED) and high-energy detector (HED) as the difference between the output signal increases. HED, especially in the size of the output signal decreases with increasing thickness of the copper filter was found.