• Journal of the Korean Recycled Construction Resources Institute
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• v.3 no.4
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• pp.301-306
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• 2015

For the purpose of developing high performance marine concrete with improved crack resistance and durability, this analytical study aimed to estimate strength, hydration heat characteristics, and chloride attack resistance of concrete with mineral admixture. Ground granulated furnace slag and fly ash were considered for mineral admixture. The replacement of ground granulated furnace slag and fly ash considered in the analysis was in the range of 0~70% and 0~40 %, respectively. The analysis results indicated that both ground granulated furnace slag and fly ash decreased compressive strength, and the effect of adding ground granulated furnace slag on mitigation of hydration heat was limited whereas fly ash had an noticeable influence on it. It was also found that the replacement with ground granulated furnace slag enhanced the chloride attack resistance but fly ash deteriorated the resistance. From the analytical studies, It could be expected that a ternary blended cement composition with proper amount of ground granulated furnace slag and fly ash might be effective to control crack resistance as well as chloride attack resistance of marine concrete.

• Ocean and Polar Research
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• v.44 no.3
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• pp.221-233
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• 2022

A sediment trap had been deployed at 1250 m depth in the Eastern Tropical Pacific (ETP) from September 2009 to July 2010, with the aim of understanding the temporal and vertical variability of particle flux. During the monitoring period, total particle flux varied from 12.4 to 101.0 mg m^-2day^-1, with the higher fluxes in January-March 2010. Biogenic particle flux varied in phase with the total particle flux. The increase in total particle flux during January-March 2010 was attributed to the enhanced biological production in the surface layer caused by wind-driven mixing in response to the seasonal shifts in the location of the Intertropical convergence zone. The export ratio (e-ratio) was estimated using the particulate organic carbon flux and satellite-derived net primary production data. The estimated e-ratios changed between 0.8% and 2.8% (1.4±0.6% on average). The ratio recorded in the negative phase of Pacific decadal oscillation (PDO) was similar to the previous results obtained from the ETP during the 1992/93 periods in the positive phase of PDO. This suggests that the regime shift of the PDO is not related to the carbon export ratio.

• The Science & Technology
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• v.9 no.8 s.87
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• pp.23-27
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• 1976

우리나라에서 본격적으로 물리탐사를 시도한것은 1958~1960년에 실시한 항공자력탐사로서 그후 현재까지 불과 20년이 지나지 않았다. 그간 물리탐사의 기술발전으로 자원탐사분야에 많은 공헌이 있었다. 현재까지 주로 적용된 분야는 철자원탐사를 위한 자력탐사, 지하수조사를 위한 전기비저항탐사동, 연등의 통화금속광물탐사를 위한 각종 전기탐사, 제3기층 지질구조와 땜공사, 공업단지조성등의 기반암조사, 그리고 광산의 갱내 출수조사등을 위한 탄성파탐사, 우라늄자원을 위한 방사능탐사, 그리고 해저지질 및 자원조사를 위한 해상물리탐사등이다. 이와 동시에 석탄층조사를 위한 전기탐사 및 Model연구자력탐사의 전산처리 적용, 그리고 광물 및 암석의 물리적 성질등 학술분야에 대한 기초연구도 계속하여 왔다. 우리나라에 있어 물리탐사의 적용조건은 비교적 험악한 지형, 복잡한 지질구조, 광상의 불규칙 또는 소규모의 발달과 산재등이다. 이와 같은 특징은 탐사해석의 정도를 높이기 위하여 보다 고도의 과학기술문제의 해결을 요구하고 있으며 이와 동시에 현대적 탐사방법과 연구개발로 대상자원의 탐사지역확대와 지하심부 탐사등이 당면과제이다. 기술과제로서는 석탄 및 기타자원에 대한 물리검층탐사, 경상계 지질구조구명을 위한 탄성파탐사 및 동력탐사의 적용, 항공자력, 전자 및 방사능탐사 및 해양의 각종물리탐사의 기술개발이 있으며 그외 탐사자료의 전산처리기술 및 지구과학의 기초연구등이 있다.

• Ocean and Polar Research
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• v.27 no.1
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• pp.97-108
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• 2005

The International Seabed Authority (ISA) formally came into existence upon the entry into force of the UNCLOS on 16 November 1994. By adopting the Implementing Agreement in 1994, UNCLOS has the universality as a Magna Carta of International Ocean Regime, and the Deep Seabed Mining Regime could be operated as a unique one for the benefit of mankind. During last 10 years, ISA established the institutional framework successfully and made substantial and tangible progress in formulating the rules, regulations and procedures for the prospecting and exploration for polymetally nodules. Furthermore, RPI's obligations had been carried out completely, and the 7 RPI made contract with ISA to become a contractor who has an at least 15 you exclusive right for exploration in their allocated site. However, due to the uncertainty of commercial mining, the number of representatives from developing countries has been getting looser and looser and ISA has a problem of quorum of the Assembly. Land-based producers took a very strong opposite position to the contractors to make their loss in the minimum level. For the next decade, it might be prospected that ISA will focus on monitoring the contractor's activities, making rules, regulations and procedures for exploration on cobalt rich crust, sulphide and methane hydrate and implementing environment studies.

• Bulletin of the Society of Naval Architects of Korea
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• v.33 no.4
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• pp.67-75
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• 1996

일찌기 20세기 초반부터 지구의 마지막 남은 자원의 보고로서 또한 미래의 생화공간으로서 해양에 대한 관심이 고조되어 왔다. 해양의 에너지/광물 자원의 개발을 위한 노력은 이미 1950년대 부터 시작되어 상당한 가시적인 성과를 얻고 있다. 최근에는 특히 환경보존에 대한 관심이 고조됨에 따라 육상기피시설물(공항, 폐기물 처리시설, 원자력 발전설비 등)들의 부지확보 문제를 해결하기 위하여 해양공간을 활용하는 방안이 선진각국에서 연구되고 있으며, 그중 가장 타당성이 높은 방안의 하난로서 각종 생산활동을 위한 플랜트를 대형 부유구조물 위에 설치하는 해상플랜트(Barge Mounted Plant, BMP)가 제안되고 있다. 원자력 발전설비를 비롯한 대형 프랜트를 부유구조물 위에 설치할 경우, 지진의 영향을 극소화 할 수 있다는 장점이 있으나 해상의 파도, 조류, 바람, 일사에 의한 갑판의 열변형 등 불규칙적인 환경하중에 노출되므로 이러한 환경조건하에서 구조물이 설계 수명 동안 안전하게 기능을 다할 수 있는지를 세심하게 검토할 필요가 있다. 따라서 BMP의 안전성 평가방법에 대한 신뢰도를 높이고 평가결과에 대한 합리성을 제고하는 한편, 이를 바타응로 현재까지는 설계/건조 경험이 전무한 초대형 부유구조물의 구조설계와 관련된 기초기술 및 응용기술을 확보하는 문제는 가장 시급히 해결되어야 할 부분이다.

• Journal of Korea Spatial Information System Society
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• v.9 no.2
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• pp.55-66
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• 2007

There has been increasing concerns regarding marine mineral resources as the land energy resources has been depleting from worldwide energy crisis. Also, all the coastal countries around the world are getting into the high competition as EEZ implemented to widen each country's marine autonomy. Especially, the adoption of EEZ in UN's marine regulation agreement at the January of 1996 has aggravated conflicts among coastal countries and eventually resulted in critical agenda to determine the boundaries of EEZ among such countries. It is imperative for us to have negotiation with neighboring countries to determine the boundaries of EEZ. For the preparation of such negotiation, it is essential to have data such as mineral distribution, deep-sea geology, related agreement and marine laws, etc. Therefore, this study mainly concentrates on analyzing existing data of resources exploration and establishing standards for each type of data and manipulating data based on such standards, thereby building a database for more efficient management of EEZ data from marine resources survey. MRIS has also been developed to diversely analyze and visualize graphic and attribute data considering data usage and inter-relationship in the database. This system can provide various spatial analysis and spatial searching techniques to enable easier comparison of cost-benefit analysis and data provision of any area in EEZ thereby facilitating major policy making. In addition, the system can support sustainable management of marine resources of EEZ regions and data supply for systematic management of national marine resources. Furthermore, this will be very useful for negotiating with neighboring countries to determine EEZ boundaries to lead more favorable results.

• Economic and Environmental Geology
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• v.54 no.1
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• pp.151-160
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• 2021

2:1 clay minerals such as smectite incorporating ammonium were extracted to investigate the ammonium behavior and nitrogen isotope characteristics for two different sediment cores which were collected from shimmering sites on seafloor of the Wakamiko crater, southwestern Japan. Inorganic nitrogen contents in clay fraction were estimated by calibration curve based on consistently decreasing carbon and nitrogen ratio during the treatment to decompose organic materials, after removing inorganic carbon. The results show that the proportions of inorganic nitrogen for total nitrogen in clay fraction of SWS site(Core#1094MR: av. 18.2%) are higher than those in SES site(Core#1093MG: av. 11.5%). Relatively good crystallinity of the former suggests that exchangeable ammonium was transformed to non-exchangeable ammonium during more evolving diagenetic process. Nitrogen isotope variance of clay fraction(SES site: Core#1093MG: -4.4 ~ +0.2 ‰, av. -2.4 ‰; SWS site: Core#1094MR: -0.7 ~ +3.0 ‰, av. +1.5 ‰) during sequential decomposition of exchangeable ammonium suggests that heat flow derived from deep magma led to nitrogen isotope fractionation between dissolved ammonium and ammonia in the fluids involved in the formation of 2:1 clay mineral incorporating ammonium with local temperature variation.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2002.10a
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• pp.45-50
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• 2002

This study presents a modeling method to predict fate of resuspended sediment in the development of deep-sea mineral resources. Resuspended deep-sea sediment during the development is considered a major environmental problem. In order to quantitatively analyze the resuspended sediment in the water column, particle size distribution (PSD) is considered an important factor. The model developed here includes PSD and coagulation process, as well as sedimentation process. Using the model, basic simulation was performed under representative environmental setting. The simulation showed the dynamics of change of particle size distribution for 50 m depth of water column up to 10 days of simulation time. Coagulation seemed an important factor in the fate of resuspended deep-sea sediment.

• Ocean and Polar Research
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• v.41 no.3
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• pp.169-181
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• 2019

The purpose of this study is to develop geochemical tracers to identify a specific source desert of mineral dust in China using the published data. In addition, we tested the applicability of these tracers to wet-deposits and soil samples collected in Jeju, Korea. Because of similarity in trace elemental compositions of mineral dust from the major arid regions in China, such as Taklimakan, West Ordos (Badain Jaran), East Ordos (Mu Us and Hobq), East Northern China (Horqin), West Northern China (Gurbantunggut), and Chinese Loess Plateau, there has been limited to the use of geochemical data for source identification. Here we propose the four (4) plots using combination of seven (7) geochemical variables as a source indicator to distinguish one from other source regions in China: $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$, where $_N$ and $\(\frac{Ce}{Ce}\)_N^*$ stand for values normalized to Post-Archean Average Shale composition and Ce anomaly, respectively. Mineral dusts from aforementioned six major deserts are distinguished one from the others by the combined use of these variables. Jeju rock and soil samples form a separate domain from Chinese mineral dusts in all four plots. In contrast, most of Jeju dust samples were comparable with the West Ordos desert (Badain Jaran) domain, indicative of strong influence of Badain Jaran dust in Jeju in spring season when the mineral dust was collected. A weak positive Ce anomaly in Jeju samples implies minimal local contribution. Our study suggests that the combination of $\frac{Y}{Tb_N}$ vs. $\frac{Th}{{\Sigma}REE_N}$, $\(\frac{La}{Gd}\)_N$ vs. $\frac{Y}{{\Sigma}REE_N}$, $\frac{Th}{Tb_N}$ vs. $\frac{Y}{Nd_N}$, and $\frac{Th}{Tb_N}$ vs. $\(\frac{Ce}{Ce}\)_N^*$ can be used to identify a specific source region of mineral dust in China as well as Jeju mineral particles.

• Resources Recycling
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• v.28 no.4
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• pp.51-58
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• 2019

Dismantlement of lithium primary batteries without explosion is required to recycle the lithium primary batteries which could be exploded by heating too much or crushing. In the present study, the optimum discharging condition was investigated to dismantle the batteries without explosion. When the batteries were discharged with $0.5kmol{\cdot}m^{-3}$ sulfuric acid, the reactivity of the batteries decreased after 4 days at $35^{\circ}C$ and after 1 day at $50^{\circ}C$, respectively. This result shows that higher temperature removed the high reactivity of the batteries. Because loss of metals recycled increases when the batteries are discharged only with the sulfuric acid, discharging process using acid solution and water was newly proposed. When the batteries were discharged with water during 24 hours after discharging with $0.5kmol{\cdot}m^{-3}$ sulfuric acid during 6 hours, the batteries discharged were dismantled without explosion. Because decrease in loss of metals was accomplished by new process, the recycling process of the batteries could become economic by the 2-step discharging process.