• Asian-Australasian Journal of Animal Sciences
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• 제16권5호
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• pp.702-705
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• 2003

Forest by-product silage (FPS) comprised of foliage, shrubs, and wild grasses was prepared to examine feeding value as sole roughage source for spotted (sika) deer. This diet was compared with imported oak leaf hay (OLH) and a commercial mixed ration (CMR) in digestion balance trials with spotted deer. Dry matter intake was highest (p<0.05) on the OLH, whereas intakes of the FPS and CMR were similar (p>0.05). Digestibility of dry matter was highest (p<0.05) for CMR. Digestibility of crude protein was highest in CMR and lowest in OLH and there were significant differences (p<0.05) among diets. Average daily gain, digestible dry matter intake and digestibility of crude fiber did not differ significantly among diets. Nitrogen intake, urinary and digestible nitrogen were highest (p<0.05) in CMR. However, nitrogen retention was not significantly different. Consequently, FPS is a good roughage source for deer having high digestibility, dry matter intake and availability of nitrogen.

• Nuclear Engineering and Technology
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• 제52권1호
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• pp.109-114
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• 2020

This work presents the results of laboratory scale tests of the CARBOFLUOREX (CARBOnate FLUORide EXtraction) process - a novel technology for the recovery of U and Pu from the solid fluorides residue (fluorination ash) of Fluoride Volatility Method (FVM) reprocessing of spent nuclear fuel (SNF). To study the oxidative leaching of U from the fluorination ash (FA) by Na₂CO₃ or Na₂CO₃-H₂O₂ solutions followed by solvent extraction by methyltrioctylammonium carbonate in toluene and purification of U from the fission products (FPs) impurities we used a surrogate of FA consisting of UF₄ or UO₂F₂, and FPs fluorides with stable isotopes of Ce, Zr, Sr, Ba, Cs, Fe, Cr, Ni, La, Nd, Pr, Sm. Purification factors of U from impurities at the solvent extraction refining stage reached the values of 10⁴-10⁵, and up to 10⁶ upon the completion of the processing cycle. Obtained results showed a high efficiency of the CARBOFLUOREX process for recovery and separating of U from FPs contained in FA, which allows completing of the FVM cycle with recovery of U and Pu from hardly processed FA.

• Nuclear Engineering and Technology
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• 제51권7호
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• pp.1799-1804
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• 2019

The concept of a new method, the CARBEX (CARBonate EXtraction) process, was proposed for reprocessing of spent uranium oxide fuel. The proposed process is based on use of water solutions of $Na_2CO_3$ or $(NH_4)_2CO_3$ and solvent extraction (SE) by the quaternary ammonium compounds for selective recovery and purification of U from the fission products (FPs). Applying of SE allows to reach high degree of purification of U from FPs. Carrying out the processes in poorly aggressive alkaline carbonate media leads to increasing safety of SNF's reprocessing and better selectivity of separation of lanthanides and actinides. Moreover carbonate reprocessing media allows to carry out a recycling and regeneration of reagents. We have been done laboratory scale experiments on the extraction components of simulated voloxidated spent fuel in the solutions of NaOH or $Na_2CO_3-H_2O_2$ and recovery of U from carbonate solutions by SE method using carbonate of methyltrioctylammonium in toluene. It was shown that the purification factors of U from impurities of simulated FPs reached values $10^3-10^5$. The received results support our opinion that CARBEX after the further development can become more safe, simple and profitable method of spent fuel reprocessing.

• Nuclear Engineering and Technology
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• 제56권4호
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• pp.1480-1489
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• 2024

Displacement cascade behaviors of Ti-6Al-4V alloys are investigated using molecular dynamics (MD) simulation. The embedded atom method (EAM) potential including Ti, Al and V elements is modified by adding Ziegler-Biersack-Littmark (ZBL) potential to describe the short-range interaction among different atoms. The time evolution of displacement cascades at the atomic scale is quantitatively evaluated with the energy of primary knock-on atom (PKA) ranging from 0.5 keV to 15 keV, and that for pure Ti is also computed as a comparison. The effects of temperature and incident direction of PKA are studied in detail. The results show that the temperature reduces the number of surviving Frenkel pairs (FPs), and the incident direction of PKA shows little correlation with them. Furthermore, the increasing temperature promotes the point defects to form clusters but reduces the number of defects due to the accelerated recombination of vacancies and interstitial atoms at relatively high temperature. The cluster fractions of interstitials and vacancies both increase with the PKA energy, whereas the increase of interstitial cluster is slightly larger due to their higher mobility. Compared to pure Ti, the presence of Al and V is beneficial to the formation of interstitial clusters and indirectly hinders the production of vacancy clusters.

• 한국위성정보통신학회논문지
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• 제12권4호
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• pp.78-86
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• 2017

일본은 과거 2차 세계대전과 러시아와 북방4개 도서 영토분쟁, 중국과 센카쿠 열도 및 태평양 진출정책 등으로 인한 갈등문제로 주변 국가 무기체계에 대한 정보획득에 지속적인 관심을 갖고 정보자산 확충에 많은 투자를 해왔으며 1998년에 북한의 대포동 미사일 발사 계기로 고주파수대역을 활용한 탄도미사일 탐지 및 요격을 위한 정책수립, 탐지체계 개발, 요격무기체계 도입에 많은 예산을 사용해왔다. 1950~1960년대 미군에서 설치, 운용하던 SIGINT장비를 미국으로부터 이전받아 기술분석 후 성능이 우수한 SIGINT장비를 제작, 일본 전역 19개소에 설치하였고, 첨단 조기경보 레이더도 국내업체에서 제작, 28개소에 설치하여 일본영역으로 침입하는 항공기와 고속으로 비행하는 탄도미사일을 감시하고 있다. 해상도가 우수한 광학 및 SAR위성 6기의 위성정찰체계와 탄도미사일 탐지능력이 탁월한 이지스함 6척을 해상에 배치하여 미사일 발사 준비 활동과 엔진실험, 미사일 발사 순간을 언제든지 탐지가 가능하며 또한 미국과의 긴밀한 공조로 우주적외선 감시망인 SBIRS망에 접근하여 주변국의 탄도미사일 발사를 조기에 탐지가 가능하다. 향후에도 동북 동남아시아에서 미군에 대한 일본의 역할이 증가되기 때문에 일본의 미사일의 탐지능력은 더욱 확장되리라 예상된다.