• Mineral and Industry
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• v.21 no.1
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• pp.56-66
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• 2008

이 동향자료는 Geoscience Australia에서 2001년 발간한 "Geoscience Australia Mineral Resources Report No.1"과 역시 동 기관에서 2007년 발행한 "Australia's Identified Mineral Resources 2007" 중 일부 내용을 발췌하여 정리 한 것으로서 요약하면 다음과 같다. OECD/NEA와 IAEA(2000)는 세계적으로 분포하는 우라늄 광상유형을 지질학적인 형성환경에 따라 15개 유형으로 분류하였으며 호주에서는 각력복합형, 부정합형, 사암형, 지표형, 변성교대형, 변성형, 화산형, 관입형 및 맥상형이 보고되어 있다. 유형별 자원량은 각력복합형, 부정합형 및 사암형 3개 유형 광상이 약 93%를 차지하며, 각력복합형광상의 자원량이 63%에 달한다. 현재 개발되는 광상은 각력복합형의 올림픽댐 광산, 부정합형인 레인저 광산 및 사암형인 베벌리 광산이다. 호주는 세계 총 우라늄 자원량의 27%를 보유하고 있어 세계 1위를 차지한다. 올림픽댐광상이 항내채광을 하는 우라늄 광산으로서는 세계에서 가장 큰 광상으로서 US$80 이하에서 회수가능한 RAR(적정확정자원량)이 476,000톤이다. 이 자원량은 세계 총 자원량의 18%를 차지하며, 단일 광산으로서는 세계최대규모이다. 2006년 호주의 우라늄 총생산량은 $U_3O_8$ 8,943톤(7,584톤 U)이며 이는 세 광산에서 생산된 양으로서 캐나다에 이어 두 번째로 많은 양(세계 생산량의 19%)이다. 2006년 우라늄 수출량은 $U_3O_8$ 8,660톤(7,344톤 U)이며 수출가는 호주달러 5억2천9백만불에 달한다. 호주는 우라늄 수출국들과 "원자력협력협약"을 맺어 평화적 목적을 위해서만 공급한다는 단서를 달고 있으며 IAEA에 의해 관리/감독되고 있다. 최근 호주 정부는 지구과학연구소에 많은 예산을 투여하여 육상에너지안전대책을 발의하여 자원개발에 요구되는 탐사자료 확보에 주력하고 있다.

• The Journal of the Petrological Society of Korea
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• v.23 no.4
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• pp.393-403
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• 2014

U-Pb ages were determined from the Yongyudo biotite granites from western parts of Gyeonggi massif. The results show that the emplacement age of the Yongyudo biotite granite is ca. 227-230 Ma. Such age result that is somewhat older than previous reported ages, suggesting further investigations for the timing and evolution of the Jurassic granites of the western Gyeonggi massif.

• Resources Recycling
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• v.20 no.2
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• pp.30-44
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• 2011

This review describes the involvement of different microorganisms for the recovery of uranium from the ore. Mainly Acidithiobacillus forrooxidans, Acidithiobacillus thiooxidans and Leptospirillum ferrooxidans are found to be the most widely used bacteria in the bioleaching process of uranium. The bioleaching of uranium generally follows indirect mechanism in which bacteria provide the ferric iron required to oxidize $U^{4+}$. Commercial applications of bioleaching have been incorporated for extracting valuable metals, due to its favorable process economics and reduced environmental problems compared to conventional metal recovery processes such as smelting. At present the uranium is recovered through main bioleaching techniques employed by heap, dump and in situ leaching. Process development has included recognition of the importance of aeration of bioheaps, and improvements in stirred tank reactor design and operation. Concurrently, knowledge of the key microorganisms involved in these processes has advanced, aided by advances in molecular biology to characterize microbial populations.

• KOREAN POULTRY JOURNAL
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• v.39 no.12 s.458
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• pp.130-133
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• 2007

• Analytical Science and Technology
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• v.17 no.4
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• pp.302-307
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• 2004

Determination of actinides in the environmental sample requires separation of each element. This procedure is tedious and time consuming. And also, the detection limits of some nuclides using alpha spectrometry are rather higher. To overcome the lower detection limit and complicated separation procedure, a simple analytical technique for the determination of actinide isotopes in the environmental samples was developed and applied to IAEA and NIST reference sediment samples. For the separation of actinides from matrix, anion exchange resin and TRU-spec extraction chromatography resin were used and chemical yields were obtained using natural uranium, thorium, $^{242}Pu$ and $^{243}Am$ tracers. For overcoming the higher detection limits of U and Th in alpha spectrometry, neutron activation analysis was applied. Using combined method, the detection limit was increased about 10 times. The activity values of each isotope were consistent with the reference values reported by IAEA and NIST.

• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.298-304
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• 2006

This study was carried out to elucidate the relationship among exercise, bone mineral density and antioxidant enzyme activity of postmenopausal women. 60 women residing in the Iksan, Korea area were recruited. The questionnaires were designed to find out exercise habits. Bone mineral density (BMD) was measured by dual energy X-ray absorptiometry. Parameters of antioxidative capacity, including the activities of superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT) and total antioxidant capacity (TA) were analyzed in fasting blood. The mean age, height, weight, and BMI of subjects were 65.0 years, 151.1 cm, 59.5 kg $26.0\;m/kg^2$, respectively. The mean BMDs of subjects were $0.85\;g/cm^2$ (lumbar spine), $0.6\;g/cm^2$ (Femoral neck), $0.49\;g/cm^2$ (trochanter), and $0.40\;g/cm^2$ (Ward's triangle). There was a significant difference in BMD among different age groups (50's, 60's and 70's) showing lower value with increasing age (p<0.05). The mean SOD, GPx, and CAT activities were 138.5 U/mL, 1,273.8 U/mL and 314.3 kU/L respectively, and TA was 1.16 mmol/L. TA of the group which exercised 3$\sim$4 times a week was significantly higher than those of the other exercise groups (p<0.05). The subjects with higher SOD activity also have a higher the T values in the lumbar spine, femoral neck, trochanter, and Ward's triangle. In conclusion, this study revealed that the levels of antioxidant enzyme activity were closely associated with the exercise status and bone mineral density in postmenopausal women.

• The Journal of Engineering Geology
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• v.21 no.3
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• pp.259-269
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• 2011

Concentrations of uranium (U) and radon (Rn) were measured in groundwater from 74 wells in the Icheon area, with the aim of determining the range and distribution of concentrations in an area underlain by granite (in this case, the Icheon granite). U concentrations ranged from 0.02 to 1,640.0 ${\mu}g/L$ (median value, 2.03 ${\mu}g/L$) and Rn concentrations ranged from 40 to 23,400 pCi/L (median value, 4,649 pCi/L). U concentrations in 10.8% of the samples exceeded 30 ${\mu}g/L$, which is the maximum contaminant level (MCL) proposed by the US Environmental Protection agency (EPA), based on the chemical toxicity of U. In addition, U concentrations in 59.5% and 13.5% of the samples exceeded 4,000 pCi/L (the Alternative MCL (AMCL) of the US EPA) and 8,100 pCi/L (Finland’s guideline level), respectively. We found no significant correlations between U (Rn) and other constituents, except for U-$HCO_3$ (correlation coefficient of 0.71), U-Ca (0.69), U-Li (0.45), U-Sr (0.43), and U-F (0.42). U and Rn contents in the groundwater are low relative to those in areas in other countries with similar geological settings, possibly due to the inflow of shallow groundwater to the wells in the Icheon area.

• Economic and Environmental Geology
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• v.46 no.5
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• pp.455-468
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• 2013

We performed reconnaissance survey on Dashinchilen Nb-Ta REE area and Sant Cu area which are located in southeastern part of Khangai rare metals mineralized belt. In Dashinchilen area, Nb and Ta have been found in pegmatitic granite that is largely distributed in the survey area and muscovite in pegmatite which is an intrusion in paleozoic sedimentary rocks which are mostly composed of sandstone. While grades of Nb and Ta are not high, an outcrop that has high Th and U contents (542 ppm of Th and 56.9 ppm of U) has been found. Average and maximum REE contents in the survey area is three times and seven times, respectively, larger than average REE contents in the crust of the Earth. In Sant area, copper oxides such as malachite has been found in quartzite in paleozoic sedimentary rocks. A sedimentary rock formation that has high grade of Mn (12.4-34.6 %) has been found in the survey area. This sedimentary rock formation is the same formation with that of Ugii Nuur Fe-Mn mineralization which is located about 200 km northwest of the survey area. Average and maximum REE contents in the survey area is two and half times and seven times, respectively, larger than average REE contents in the crust of the Earth. According to the factor analysis for the data of the geochemical analysis, Nb and Ta in Dashinchilen area are highly correlated with muscovite and Cu in Sant area is highly correlated with Mo, Sn, and Bi. Furthermore, the factor analysis results show that Fe in Sant area was deposited with rare earth elements.

• The Journal of the Petrological Society of Korea
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• v.24 no.1
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• pp.55-63
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• 2015

We investigated the zircon U-Pb ages of the metapelites from the Sungjeon-myeon Gangjin-gun, the southwestern Ogcheon belt, to provide geochronological constraints for the depositional age as well as the distribution of Late Paleozoic formation. Data from the detrital zircons are mostly concordant, yielding four major age groups: (1) Neoarchean (~2.5 Ga); (2) Paleoproterozoic (~1.86 Ga, Statherian); (3) Middle Devonian(~390 Ma); and (4) Late Paleozoic (~322 Ma, Serpukhobian). The youngest zircon age gives a weighted mean $^{206}Pb/^{238}U$ age of $322{\pm}4.8$ Ma (n=16, MSWD=4.9), indicating deposition age of Early Carboniferous(Serpukhobian) or after. Therefore, the metapelites is considered to be the lowest Formation of the late Paleozoic Pyeongan Supergroup correlated with the Manhang Formation of the Samcheock coal fields and the Oeumri Formation(the Middle to Late Carboniferous) of the Hwasun coal field.

• Proceedings of the Korean Geotechical Society Conference
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• 1998.10a
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• pp.57-64
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• 1998