• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2005년도 추계 학술발표회 발표논문집
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• pp.192-194
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• 2005

O$_3$/H$_2$O$_2$ 고급산화공정에서 1,4-D의 제거는 반응시간에 따라 완만하게 감소하였으나, O$_3$/catalyst 고급산화공정에서는 전체 제거량의 약 50${\sim}$75%가 반응 초기 5분 내에 제거되어 O$_3$/H$_2$O$_2$ 공정에 비해 초기 반응속도가 현저히 빠른 것을 알 수 있었다. O$_3$/H$_2$O$_2$ 고급산화공정은 ${\Delta}$TOC/${\Delta}$ThOC의 비는 0.09${\sim}$0.40으로 나타났으며, O$_3$/catalyst 고급산화공정에서는 ${\Delta}$TOC/${\Delta}$ThOC의 비가 0.68${\sim}$0.98로 나타나 O$_3$/catalyst 고급산화공정이 O$_3$/H$_2$O$_2$ 고급산화공정에 비해 유기물의 산화력이 우수한 것으로 확인되었다.

• 치과방사선
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• 제20권1호
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• pp.53-62
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• 1990

This experiment was performed to clarify the effects of /sup 60/Co gamma irradiation on secretory function, amylase activity and contents of nucleic acids of parotid gland in rat. Experimental animals were divided into 6th hours, 3rd, 7th, 14th and 28th days after irradiation and control. The experimental animals are singly irradiated with 20Gy (2,000rad) through protective lead block. Secretory function of parotid gland was evaluted by uptake and clearance of /sup 99m/TcO₄. /sup 99m/TcO₄. 0.2μ ci/gm, was injected into peritonium in uptake groups. Rats were sacrified with cervical dislocation after 30 minutes and gland was excised. In the clearance group. pilocarpine nitrate (8㎎/㎏) was intraperitoneally injected at 30 minutes after /sup 99m/TcO₄ injection and rats were sacrified 30 minutes after pilocarpine injection. Radioactivity of excised parotid gland was measured by using of gamma counter and stimulation-secretion coefficients, uptake radioactivity divided by clearance radioactivity, was calculated. Amylase activity and contents of DNA and RNA were determined by spectrophotometry. The results obtained were as follows: 1. In the uptake test, the radioactivity of /sup 99m/TcO₄ per unit weight increase in experimental group except 6th hours group, compared with control groups and showed a peak at 3rd days after irradiation. 2. In the clearance test, the radioactivity of /sup 99m/cO₄per unit weight rose to a peak at 3rd days after irradiation and gradually recovered thereafter. 3. Stimulation-secretion coefficient of parotid gland decreased at 6th hours, 3rd and 7th days after irradiation, and gradually increased. 4. Amylase activity of parotid gland decreased in 3rd and 7th days group, and especially lowest in 3rd days after irradiation. 5. The contents of DNA showed no definite difference in all the experimental groups, but RNA was seemed to decrease with time after irradiation.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2001년도 추계학술발표회요약집
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• pp.222.1-222
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• 2001

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 춘계공동학술발표회요약집
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• pp.240.1-240
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• 2002

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1733-1739
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• 2017

Molecular dynamics simulations were performed to investigate the uniaxial tensile properties of nanocrystalline $U_{0.5}Th_{0.5}O_2$ solid solution with the Born-Mayer-Huggins potential. The results indicated that the elastic modulus increased linearly with the density relative to a single crystal, but decreased with increasing temperature. The simulated nanocrystalline $U_{0.5}Th_{0.5}O_2$ exhibited a breakdown in the Halle-Petch relation with mean grain size varying from 3.0 nm to 18.0 nm. Moreover, the elastic modulus of $U_{1-y}Th_yO_2$ solid solutions with different content of thorium at 300 K was also studied and the results accorded well with the experimental data available in the literature. In addition, the fracture mode of nanocrystalline $U_{0.5}Th_{0.5}O_2$ was inclined to be ductile because the fracture behavior was preceded by some moderate amount of plastic deformation, which is different from what has been seen earlier in simulations of pure $UO_2$.

• 대한화학회지
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• 제56권1호
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• pp.62-67
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• 2012

A series of homo binuclear complexs of the type $[M_2(L/L^')(NO_3)n].mH_2O$, [where $M=U{O_2}^{2+},\;Th^{4+},\;ZrO^{2+}$] and $[(VO)_2(L/L^')(SO_4)_2]{\cdot}2H_2O$, L=1,5,6,9,12,15,16,20 octaaza-7,813,14-tetraphenyl-2,4,17,19-tetramethyl-1,4,6,8,12,14,16,19-docosaoctene (OTTDO) or L'=10:11;21:22-dibenzo-1,5,6,9,12,15,16,20-octaaza-7,813,14-tetraphenyl-2,4,17,19-tetramethyl-1,4,6,8,12,14,16,19-docosaoctene (DOTTOT), n=4 for $U{O_2}^{2+}$, $ZrO^{2+}$ n=8 for $Th^{4+}$ m=1,2,3 respectively, have been synthesized in template method from ethylenediamine/orthophenylene diamine, benzil monohydrazone and acetyl acetone and characterized on the basis of elemental analysis, thermal analysis, molar conductivity, magnetic moment, electronic, infrared, $^1H$-NMR studies. The results indicate that the VO(IV) ion is penta co-ordinated yielding paramagnetic complexes; $UO_2(VI)$, ZrO(IV) ions are hexa co-ordinated where as Th(IV) ion is octa co-ordinated yielding diamagnetic complexes of above composition. The fungi toxicity of the ZrO(IV) and VO(IV) complexes against some fungal pathogen has been studied.

• 한국광물학회지
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• 제25권4호
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• pp.295-304
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• 2012

하동군 옥종면 월횡리에는 과거 개발하던 티탄철석 광산이 위치하며, 주변 지질은 선캄브리아기 지리산 편마암 복합체가 광범위하게 분포하고 이를 회장암이 관입하고 있다. 간극누적형 회장암체 내 티탄철 광체가 발달하고 있으며, Ti-광체 내 희토류원소를 포함하는 갈렴석이 맥상으로 발달하고 있다. 갈렴석의 CaO 함량은 11.02~12.81 wt%로 낮은 반면, ${\Sigma}R_2O_3$는 상대적으로 높은 17.21~21.58 wt% (R=Ce, La, Nd)의 범위를 보여준다. 갈렴석이 높은 방사능 이상치를 보여주는 이유는 갈렴석 내에 미립의 광물상으로 존재하는 토륨 광물인 톨라이트(thorite, $ThSiO_4$) 때문인 것으로 밝혀졌다. 톨라이트는 $3{\sim}6{\mu}m$ 크기의 입상으로 누대구조를 보여주며, 화학분석 결과 $ThO_2$는 65~72.78 wt%, $UO_2$는 5.49~12.78 wt%의 함량을 보였다. 이러한 광물학적 특성은 톨라이트를 함 REE 갈렴석을 찾는 방사능 탐사를 함에 있어 좋은 지시자로 이용할 수 있을 것으로 사료된다.

• Nuclear Engineering and Technology
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• 제52권6호
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• pp.1156-1163
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• 2020

Fuel temperature coefficient (FTC) of PuO₂+ZrO₂ (ROX) fueled LWR cell is analyzed neutronically with reactor- and weapons-grade plutonium fuels in comparison with a U-free PuO₂+ThO₂ (TOX), and a conventional MOX fuel cells. The FTC value of a ROX fueled LWR is smaller compared to a TOX or a MOX fueled LWRs and becomes extremely positive especially, at EOL. This is because when fuel temperature is increased, thermal neutron spectrum is shifted to harder, which is extreme at EOL in ROX fuel than that in TOX and MOX fuels. Consequently at EOL, ²³⁹Pu and ²⁴¹Pu contributes to positive fuel temperature reactivity (FTR) in ROX fuel, while they have negative contribution in TOX and MOX fuels. The FTC problem of ROX fuel is mitigated by additive ThO₂, UO₂ or Er₂O₃. In ROX-additive fuel, the atomic density of fissile Pu becomes more than additive free ROX fuel especially at EOL, which is the main cause to improve the FTC problem. The density of fissile Pu is more effective to decrease the thermal spectrum shifts with increase the fuel temperature than additive ThO₂, UO₂ or Er₂O₃ in ROX fuel.

• 대한화학회지
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• 제54권4호
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• pp.395-401
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• 2010

[M(L/L')$(NO_3)_n$].$mH_2O$ 및 [VO(L/L')($SO_4)$].$2H_2O$ (여기서 L/L'는 Schiff 염기로 thiocarbohydrazide (TCH), benzilmonohydrazone (BMH)/diacetylmonohydrazone (DMH) 및 carbon disulphide에서 유도된 "3,4,10,11-tetraphenyl/tetramethyl-1,2,5,6,8,9,12,13-octaazacyclotetradeca-2,4,9,11-tetraene-7,14-dithione")의 분자식을 갖는 일련의 거대고리 착물을 (M = $UO_2$(VI), Th(IV) and ZrO(IV), n = 2, 4, m = 2, 3)을 금속이온 주형법으로 합성하였다. 이들 착물의 특성을 원소분석, 열분석, 몰 전기전도도, 자기모멘트 그리고 전자, 적외선 및 $^1H$-NMR로 조사하였다. 바나딜 착물의 경우 ESR 및 순환 전압전류법을 사용하였다. 그 결과, VO(IV) 이온은 5배위의 상자기성 착물을 이루며, $UO_2$(VI) 및 ZrO(IV)는 6배위 그리고 Th(IV)는 8배위를 가지나 공통적으로 위의 조성을 갖는 반자기성임을 알았다.

• The International Journal of Costume Culture
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• 제7권1호
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• pp.40-47
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• 2004

The purpose of this research was to examine the degradation rate of alizarin in accelerated degradation conditions using the GC-MS quantitative analysis. Alizarin dye solution (2.5 x 10/sup -3/ M conc.) were kept in 150℃ oven for total of 7 days and the degradation rate was examined each day. 2.5 × 10/sup -4/M conc. alizarin dye solution was mixed with H₂O₂ according to [H₂O₂]/[dye] ratio 40 and were kept under 365㎚ UV for 2 hours, analyzed after 0, 30, 60, 90, 120min using the GC-MS. Gas chromatogram showed alizarin peak at 9.96 - 10.13 min. retention time range and residual peaks in the wide range from 9.6 to 11.1 min. Oven degradation exhibited an initial decrease in the amount of alizarin, which was followed by increasing amount in 4/sup th/ day. The decrease in the alizarin was significantly shown by the 7/sup th/ day. Same pattern was also observed in the H₂O₂/UV/O₂ degradation samples and was verified ed by the UV-VIS spectra. The differences in the amount of alizarin between 1/sup st/ day and 4/sup th/ day samples, 4/sup th/ day and 7/sup th/ day samples, and Control and 7/sup th/ day samples of the oven degradation were significant at alpha .20.