• Nuclear Engineering and Technology
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• 제39권5호
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• pp.663-672
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• 2007

The mutual separation behavior of actinides and rare earths in a countercurrent multistage reductive extraction system was predicted by computer calculation. The distribution information for actinides and rare earths in the reductive extraction systems of LiCl-KCl/Cd and LiCl-KCl/Bi was collected from literature and then it was used for the calculation of a multistage extraction. The results of the concentration profiles throughout the extraction cascade, recovery yields of various metal solutes, and separation factors between the actinides and rare earths were calculated. The effects of the major process parameters, such as reducing agent content in the metal phase, number of stages, and salt/metal flow ratio, etc., on the extraction behavior were also examined.

• Advances in aircraft and spacecraft science
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• 제1권4호
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• pp.443-454
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• 2014

An experimental study was conducted to investigate the effect of Reynolds number on compressible convex-corner flows, which correspond to an upper surface of a deflected flap of an aircraft wing. The flow is naturally developed along a flat plate with two different lengths, resulting in different incoming boundary layer thicknesses or Reynolds numbers. It is found that boundary layer Reynolds number, ranging from $8.04{\times}10^4$ to $1.63{\times}10^5$, has a minor influence on flow expansion and compression near the corner apex in the transonic flow regime, but not for the subsonic expansion flow. For shock-induced separated flow, higher peak pressure fluctuations are observed at smaller Reynolds number, corresponding to the excursion phenomena and the shorter region of shock-induced boundary layer separation. An explicit correlation of separation length with deflection angle is also presented.

• Nuclear Engineering and Technology
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• 제5권3호
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• pp.234-239
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• 1973

페이퍼 크로마토그래피에 의한 o-iodohippuric acid-$^{131}$ I와 o-iodobenzoic acid-$^{131}$ I의 분리에 관한 기보된 방법은 착오인 것으로 밝혀졌다. 이들 두 유사 화합물들의 효과적 분리를 위하여 제시된 용매는 균일하게 섞여지지 않을뿐 아니라 그대로 사용하더라도 이들 두 화합물은 분리되지 않았다. o-iodohippuric acid-$^{131}$ I의 동위원소 교환법에 의한 제조과정에서 o-iodohippuric acid가 o-iodobenzoic acid로 변환되지 알음을 확인하였으며 Hippuran-$^{131}$ I의 방사화학적 순도 결정을 위한 간편한 방법을 제시하였다.

• Journal of Mechanical Science and Technology
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• 제18권7호
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• pp.1236-1245
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• 2004

In this study, an optical imaging method was developed for the measurements of the sizes and velocities of droplets in sprays. Double-exposure single-frame spray images were captured by the imaging system. An image processing program was developed for the measurements of the sizes and positions of individual particles including separation of the overlapped particles and particle tracking and pairing at two time instants. To recognize and separate overlapping particles, the morphological method based on watershed segmentation as well as separation using the perimeter and convex hull of image was used consecutively. Better results in separation were obtained by utilization of both methods especially for the multiple or heavily-overlapped particles. The match probability method was adopted for particle tracking and pairing after identifying the positions of individual particles and it produced good matching results even for large particles like droplets in sprays. Therefore, the developed optical imaging method could provide a reliable way of analyzing the motion and size distribution of droplets produced by various sprays and atomization devices.

• Nuclear Engineering and Technology
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• 제15권2호
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• pp.149-153
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• 1983

흡착 기포 분리에 의하여 수용액으로부터 아연(II)을 회수하는 방법에 관하여 연구하였다. 그리고 흡착 기포 분리에서 용매부선 과정과 거품 분별 과정에 채용되었고 이들 분리 과정에서 카프르산을 아연의 회수 물질로 사용하였다. 이온 강도 및 수소이온의 농도가 분리 과정의 효율에 어떤 영향을 미치는지를 기술하였으며, 추출제로 벤젠에 녹은 카프르산을 이용한 용매 추출과정과도 상호 비교하였다.

• Journal of the Optical Society of Korea
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• 제17권6호
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• pp.506-512
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• 2013

Recently, the color separation issue of wide-spreading white LEDs has attracted attention due to their wide applicability as light sources in direct-lit LCD backlights. These wide-spreading LED packages usually consist of LED chips, a color-conversion phosphor layer, and a light-shaping lens. The technical aspect of this color issue was related to a method for balancing the yellow spectral component emitting from phosphors with respect to the blue one from the LED chip as a function of viewing angle. In this study, we suggested an approach for carrying out quantitative analysis for the color separation problem occurring in wide-spreading LED packages by optical simulation. In addition, the effect of an internal scattering layer on the color uniformity was investigated, which may be considered as a potential solution for this problem.

• Nuclear Engineering and Technology
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• 제53권10호
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• pp.3352-3358
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• 2021

Aiming at selective adsorption and separation of Y(III) from the Y(III)-Sr(II) group in acid solution, a silica-based TODGA impregnated adsorbent [(TODGA+1-dodecanol)/SiO₂-P-F600] has been prepared. Batch adsorption experiments were conducted under the effect of contact time, acid concentration, solution temperature, and adsorption capacity etc. Chromatography recovery of more than 90% Y(III) was successfully achieved under elution with 0.01 M DTPA solution in nitric acid adsorption system, and 0.1 M HCl solution in hydrochloride adsorption system, respectively.

• Nuclear Engineering and Technology
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• 제52권12호
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• pp.2867-2873
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• 2020

In reprocessed uranium, derived from an impoverished fuel of light-water moderated reactors, there are isotopes of ^{232, 234, 236}U, which make its recycling remarkably difficult. A method of concentration of ²³⁵U target isotope in cascade's additional product was proposed to recover the isotopic composition of reprocessed uranium. A general calculation procedure is presented and a parameters' optimization of multi-flow cascades with additional products. For the first time a numeric model of a cascade that uses the cuts of partial flows of stages with relatively high separation factors was applied in this procedure. A novel computing experiment is carried out on separation of reprocessed uranium hexafluoride with providing a high concentration of ²³⁵U in cascade's additional product with subsequent dilution. The parameters of cascades' stages are determined so as to allow reducing the ^{232, 234, 236}U isotope content up to the acceptable. It was demonstrated that the dilution of selected products by the natural waste makes it possible to receive a low enriched uranium hexafluoride that meets the ASTM C996-15 specification for commercial grade.

• 한국초전도ㆍ저온공학회논문지
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• 제8권3호
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• pp.41-44
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• 2006

This study introduced waste water treatment method by superconducting HGMS(High Gradient Magnetic Separation). HGMS treatment method is high efficient method for various waste water, we have surveyed superconducting magnetic separation technology. We fabricated the prototypes of magnetic matrix filter consisting of stainless steel mesh, which is a core component in the magnetic separation system. In our basic preliminary experiment using HGMS, it was made clear that the fine para-magnetic particles in the wasted water obtained from steelmaking process of POSCO can be separated with high efficiency.

• Nuclear Engineering and Technology
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• 제55권3호
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• pp.989-998
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• 2023

Under nuclear reactor severe accidents, the resuspension of radioactive aerosol may occur in the containment due to the disturbing airflow generated by hydrogen combustion, hydrogen explosion and containment depressurization resulting in the increase of radioactive source term in the containment. In this paper, for containment conditions, by considering the contact between particle and rough deposition surface, the distribution of the distance between two contact points of particle and deposition surface, rolling and lifting separation mechanism, resuspension model based on random contact with rough surface (RRCR) is established. Subsequently, the detailed torque and force analysis is carried out, which indicates that particles are more easily resuspended by rolling under low disturbing airflow velocity. The simulation result is compared with the experimental result and the prediction of different simulation methods, the RRCR model shows equivalent and better predictive ability, which can be applicable for simulation of aerosol resuspension in containment during severe accident.