• KSBB Journal
• /
• 제29권3호
• /
• pp.139-144
• /
• 2014

Microorganisms play a significant role in bioremediation of heavy metal contaminated seawater. In this study, we reported an effective removal of Cu and Zn in marine envionment by using Desulfovibrio desulfuricans (D. desulfuricans) which belong to sulfate reducing bacteria. D. desulfuricans showed stable growth characteristics in high salt concentration and had resistance to heavy metals. Cu and Zn was removed not only by physical adsorption on the surface of bacteria but also by precipitation reaction of microbial metabolism by D. desulfuricans in seawater. In case of different heavy metal concentration, Cu was effectively removed 85% at 25 ppm and 60% at 50 ppm and Zn was effectively removed 54% at 50 ppm and 46% at 200 ppm, respectively.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2008년도 International Meeting on Information Display
• /
• pp.1311-1314
• /
• 2008

We have developed new electrical dopants of rhenium oxide ($ReO_3$) and cupper iodide (CuI) as p-dopants and rubidium carbonate ($Rb_2CO_3$) as an n-dopant, respectively. $ReO_3$ has advantage of low temperature evaporation (about $300^{\circ}C$) with enhanced device stability. Various kinds of high performance organic light emitting diodes have been realized, including bottom emission, tandem, and top-emission OLEDs.

• 한국정밀공학회:학술대회논문집
• /
• 한국정밀공학회 1996년도 춘계학술대회 논문집
• /
• pp.646-650
• /
• 1996

In this paper, A hydrostatic bearing spindle for high precision machining and a motor built-in spindle for high speed machining are developed toobtain the high precision machining accuracy of the prototype lathe. The sliding bearing with fluoric resin (turcite) pad is adopted for improving the damping charateristics of guide ways. The funning accuracy of moving elements isestimated to confirm the validity of application on the prototype; the high precision CNC lathe. The surface roughness of Cupper and Aluminum machined by the hydrostatic spindle are 0.07 .mu. m and 0.10 .mu. mRmax. The surface roughness of Aluminium machined by the built-in spindle are 0.10 .mu. mRmax. From this results, it is venified that the prototype lathe is effective to high precision maching.

• 한국정밀공학회지
• /
• 제30권3호
• /
• pp.349-355
• /
• 2013

Recent high oil price results in the development of energy saving technology such as LED lighting system. Street-lighting system using COH LED package can save energy because the heat dissipation through cupper base is better than conventional technology. Studies on manufacturing processes of lighting system are insufficient even though LED package design and its heat analysis have been studied. This study focuses on the problem and solution of manufacturing processes such as LED packaging process, optimized emission angle, and LED bar dimension for mechanical assembly. As a result, we established better manufacturing alternatives of LED packaging and street-lighting system with higher lighting efficiency of 84 lm/W, as well as good illumination intensity of 39.7 lux at 6 m from lighting source.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 추계학술대회 논문집
• /
• pp.336-339
• /
• 2005

API steel is used for line-pipe to transport the oil and natural gas. As the recent trends in the development of API steel are towards the use of larger diameter and thicker plate, many researches have been studied to achieve higher strength, higher toughness and lower yield ratio in API steel. However, the strength of API steel after pipe forming is changed depend on the competition of the Bauschinger effect and work hardening. So, the purpose of this study is to investigate the influence on the Bauschinger effect for API steel by addition of V and Cu which are formed the precipitations for higher strength in API steel. The results are that the addition of V considered as a ferrite stabilizer and Cu considered as a austenite stabilizer decreases and increases the Bauschinger effect for API steel respectively.

• 한국재료학회:학술대회논문집
• /
• 한국재료학회 2012년도 춘계학술발표대회
• /
• pp.79.2-79.2
• /
• 2012

In this work, vertically aligned metal oxide nanorods(ZnO, $TiO_2$, $WO_3$) were grown onto CuO film at the room temperature. The fabricated nanorods of 90nm~500nm diameter range and $1{\mu}m{\sim}15{\mu}m$ of length range. Growth of metal oxide nanorods only depends on thickness of CuO film in this method, and it is grown at both of room temperature and high temperature. That means, it is much faster mathod to make the vertical metal oxide nanorods than old method such as hydrothermal method.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2011년도 제41회 하계 정기 학술대회 초록집
• /
• pp.339-339
• /
• 2011

진공 플라즈마와 달리 개방된 공간에서 방전되는 대기압 플라즈마는 진공상태에서 수행되는 에칭, 증착 등의 복잡한 플라즈마 공정을 경제적이고 신속하게 수행할 수 있어, 최근 들어 연구가 활발히 진행 중이다. 이와 관련하여 He, Ar, $N_2$, $O_2$, Air 등의 여러 종류의 기체를 50 kHz 고전압에서 방전하여 대기 중에서 저온 플라즈마 공정이 가능한 아크젯 타입의 플라즈마 소스를 개발하였다. 개발된 플라즈마 소스에서는 입력전압, 기체유량, 노즐의 구조와 크기 등의 여러 운전변수에 따라 플라즈마의 방전특성이 변화되었다. 특히 본 연구에서는 아크젯의 플라즈마 발생부의 물질성분(SUS, Aluminum, Cupper)에 따른 플라즈마의 기체온도 및 전자여기 온도의 변화를 광방출분광법(OES)를 이용한 Synthetic spectrum method와 Boltzmann plot method을 통해 살펴보았다. 전압-전류 특성곡선, 시간분해 이미지 촬영법, 기체온도 측정법 등을 이용하여 발생된 플라즈마의 물리적인 특성을 분석하였다. 특히 물질의 성분에 따라 발생되는 플라즈마의 기체 및 전자여기 온도가 이차 전자 방출계수 및 물질의 전도도와의 상관관계가 있는지 연구가 진행 중이다.

• 대한화학회지
• /
• 제16권6호
• /
• pp.373-377
• /
• 1972

미량 구리의 sodium diethyl dithiocarbamate의 chelate를 ethyl acetate로 추출하고 이 추출액을 구리(원자번호 29번)의 이웃원소인 아연(원자번호 30번) 분말에 흡착시켰다. 추출액을 날려보낸 뒤에 $250kg/cm^2$ 으로 압축성형하여 구리의 $K_{\alpha}2(2{\theta}_{LiF} = 45.08^{\circ})$에서 형광 X-선을 측정한 결과 구리 $10{\mu}g$까지 측정할 수 있었으며 표준물질첨가법에 의하여 상대오차를 ${\pm}10$%이내로 낮출수가 있었다.

• 한국세라믹학회지
• /
• 제43권10호
• /
• pp.653-659
• /
• 2006

The glass-SiC composites have been manufactured via viscous flow of glass for investigating their sinterability and various properties. The relative density of 99.6% could be achieved when 5 wt% SiC was mixed with glass powder, glass-rearranged at 460$^{\circ}C$ for 3 h and then sintered at 665$^{\circ}C$ for 1 h. The sintered density was decreased as adding more than 5 wt% SiC to glass powder. The resistance properties against hyper velocity copper jet formed by explosion of K215 warhead were compared with other ceramics such as $Al_2O_3$ and pyrex, resulting in lower values than that of $Al_2O_3$.

• 자원환경지질
• /
• 제3권3호
• /
• pp.141-161
• /
• 1970

The outline of general trend on production, consumption and price of non-ferrous metals during 1969 is summerized in the paper. The production of every non-ferrous metals has increased compare to that of last year, and their consumption except silver has also increased. Specially the rate of growth of production is that; The rate of growth of consumption is such; The prices of gold and silver have decreased since last November due to the stability of international currency and the creation of S.D.R. at I.M.F., but those of other metals have increased, marking the price at the end of 1969 as follows: Cupper price of Foreign Refinery showed ¢72.471/lb(increased 39% per year), lead and Zinc jumped up to the highest price since the Korean War (1951-1953), showing the lead price ¢16.50/lb (increased 27% per year) and the zinc price ¢15.50/lb (increased 15% per year). Price of tungsten was higher than the agreed price that was made between Korea and U.S.A. during 1951 through 1954, showing $63.4/S.T.U. (increased 13% per year). The price of molybdenum was slightly increased from $1.62 to $1.72 (increased 6% per year). In summing up, the year of 1969 was the golden age for the nonferrous metals. It is, hawever, expected that in the next few years, the consumption rate and the prices of non-ferrous metals will be declined compared to those of 1969.