• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2006년 창립20주년기념 정기학술대회 및 국제워크샵
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• pp.14-20
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• 2006

During the 11 year period of 1995-2005, there was about a 40% increase in the world copper demand mainly because of the Asian economic growth. In the increase, about a half was consumed by China. Most of the China's copper demand increase has been taken place over the final 5-6 years of that period. The growth is expected to continue for several years, and in 10 years or sooner the same situation is expected for India. Copper is the third metal in global demand, but its little abundance in the Earth's crust is not well recognized. From the production rate and the abundance, a copper shortage, or crisis, has a high probability than the other metals. Deep ocean mineral resources such as manganese nodules in the Clarion-Clipperton Fracture Zones, Kuroko-type massive seafloor sulfides (SMS), and cobalt-rich manganese crusts in the EEZ and the high sea areas have big potentials for the future sources. We need to re-evaluate their potentials as copper resources and other metals to realize their developments. The same situation is under progress in the hydro-carbon markets. Methane hydrates that are classified into non-conventional hydro-carbon resources have an important role as the future sources, too.

• Journal of Korea Trade
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• 제27권5호
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• pp.167-198
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• 2023

Purpose - This paper aims to compare and analyze the co-movements and information spillover effects between the international commodity futures markets and the South Korean stock markets during the COVID-19 and the 2008 financial crises. Design/methodology - The DCC-GARCH model is used in the co-movements analysis. In contrast, the BEKK-GARCH model is used to evaluate information spillover effects. The statistical data used is from January 1, 2005, to December 31, 2022. It comprises the Korea Composite Stock Price Index data and daily international commodity futures prices of natural gas, West Texas Intermediate crude oil, gold, silver, copper, nickel, soybean, and wheat. Findings - The results of the co-movement analysis were as follows: First, it was shown that the co-movements between the international commodity futures markets and the South Korean stock markets were temporarily strengthened when the COVID-19 and 2008 financial crises occurred. Second, the South Korean stock markets were shown to have high correlations with the copper, nickel, and crude oil futures markets. The results of the information spillover effects analysis are as follows: First, before the 2008 financial crisis, four commodity futures markets (natural gas, gold, copper, and wheat) were shown to be in two-way leading relationships with the South Korean stock markets. In contrast, seven commodity futures markets, except for the natural gas futures market, were shown to be in two-way leading relationships with the South Korean stock markets after the financial crisis. Second, before the COVID-19 crisis, most international commodity futures markets, excluding natural gas and crude oil future markets, were shown to have led the South Korean stock markets in one direction. Third, it was revealed that after the COVID-19 crisis, the connections between the South Korean stock markets and the international commodity futures markets, except for natural gas, crude oil, and gold, were completely severed. Originality/value - Useful information for portfolio strategy establishment can be provided to investors through the results of this study. In addition, it is judged that financial policy authorities can utilize the results as data for efficient regulation of the financial market and policy establishment.

• 자원리싸이클링
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• 제28권1호
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• pp.3-14
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• 2019

구리는 뛰어난 전기전도성 및 열전달 특성으로 인해 많은 전자기기 및 건축 부품에 활용되고 있고 니켈 등 다른 도금의 밑 도금으로 사용되는 등 현대 산업에서 필수적으로 사용되는 소재이다. 뿐만 아니라 차세대 산업군에서 배선, 센서, 데이터 장비의 사용량과 중요도가 더욱 커지면서 그 활용도가 더욱 커질 것으로 예상됨에도 불구하고 유럽발 경제위기, 중국 경제 저성장 기조, 트럼프 대통령의 공공 산업설비 투자 공약 등에 따라 가격이 급동하는 추세를 보여 안정적인 수급 확보 및 자원관리에 어려움을 겪는 실정이다. 국내 구리 사용량의 거의 대부분을 전기동을 이용하여 사용하기 때문에 본 연구에서는 상용화 되고 있는 구리 재활용 기술과 연구 단계에 머물고 있는 구리 재활용 기술을 구분하여 각각의 기술적 수준을 파악하였다. 이를 통해 각 공정별 특징과 향후 기술개발이 요구되는 분야를 고찰해 보고자 하였다.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2008년도 하계학술발표대회 논문집
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• pp.436-439
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• 2008

This paper is to research the heat transfer performance of the sintered pipe. Recently, oil prices is to be 127 $ per barrel, we expect higher costs this summer. We promote alternative fuels, after oil and gasoline prices reached record highs. The governments have made efforts to avoid future crisis by continuing the move toward renewable energy and energy saving. In this paper, we have fabricated a sintered pipe, the heat transfer performance of sintered pipe is achieved experimentally. The pipe is copper tube of outer diameter of 15.88 mm, the length of the pipe is 800 mm. Based on the experimental results, it is shown the overall heat transfer coefficient of sintered pipe is increased as compared with that of a straight pipe, is equal as compared with that of a spiral pipe. The overall heat transfer coefficient was $0.075{\sim}0.09\;kW/^{\circ}C$

• 한국동물위생학회지
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• 제29권4호
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• pp.459-467
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• 2006

This study was designed to investigate if there were groundwater contamination in 17 landfill where slaughtered animals were buried during the crisis of 2002 foot-and-mouth-disease (FMD) outbreaks in Gyeonggi province. From March to August 2005 groundwater was collected once a month from 17 sites, and examined with potential for hydrogen (pH), colour, turbidity, lead (Pb), arsenic (As), mercury (Hg), cadmium (Cd), copper (Cu), zinc (Zn) , iron (Fe), manganese (Mn) , aluminium (Al), nitrate-nitrogen $(NO_3-N)$, ammonia-nitrogen $(NH_3-N)$, microbial pathogen and Escherichia spp. In the examination of $NH_3-N$ which of the mean concentration was from not-detected (ND) to 0.05 mg/l. The range of $NH_3-N$ level was $0.3-24.1mg/{\ell}$. However, groundwater from four sites was to go beyond the drinking water quality standard (DWQS), i.e., the mean concentration of those were $15.5mg/{\ell}\;(site\;1),\;20.7mg/{\ell}\;(site\;9),\;24.1mg/{\ell}\;(site\;13)\;and\;10.6mg/{\ell}\;(site\;17)$. In the investigation of pH, colour and turbidity, all of the pH were below of DWQS (pH 5.8-6.6), but one site in color test and four sites in turbidity test were over the standard level. Among 9 metal ions examined, Mn was in excess of DWQS, and its concentration was $2.4mg/{\ell}$. Pb, Cd, Hg and As were not traced. The contents of Cu, Zn, Fe and Al were $ND-0.22mg/{\ell},\;0.01-0.05mg/{\ell},\;ND-0.05mg/{\ell}\;and\;0.03-0.16mg/{\ell}$, respectively. Escherichiae spp were not identified, but bacterial colonies were detected at 3 groundwater including 2 sites over the DWQS at the level of $491CFU/m{\ell}\;(site\;4)\;and\;217CFU/m{\ell}\;(site\;15)$.

• Korean Chemical Engineering Research
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• 제56권1호
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• pp.49-55
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• 2018

에너지 위기 시대를 맞이하여 수소에너지가 가장 가능성 있는 대체에너지 중의 하나로 고려되고 있다. 액체수소는 기체수소와 비교하여 단위 부피당 에너지 밀도가 월등히 높으며 수소에너지의 탁월한 저장 방법으로 간주되고 있다. 본 연구에서는 2 상 모델에 기초를 둔 Navier-Stokes 식을 전산유체역학 프로그램을 이용하여 풀었으며, 초저온 냉각 튜브를 통과하면서 기체수소가 액화되는 과정을 분석하였다. 열전도율이 높은 구리관을 초저온 냉각을 위한 관의 재질로 가정하였다. 기체수소의 유입속도를 5 cm/s, 10 cm/s, 20 cm/s로 변화시키면서 냉각튜브 내 유체 온도분포, 축방향 및 반경방향 유체 속도, 기체 및 액체 수소 부피분율 분포를 각각 분석하였다. 본 연구 결과는 향후 액체수소 제조를 위한 기체수소 초저온 냉각기의 설계 및 제작을 위한 기초자료로 활용이 될 것으로 기대된다.