• 환경생물
• /
• 제30권4호
• /
• pp.349-354
• /
• 2012

To evaluate the biological response of sea squirt Halocynthia roretzi with different body size to heavy metals and its suitability for ecotoxicity assays, the effects of Cr, Cu and Zn on its clearance and oxygen consumption rates were investigated. Clearance and oxygen consumption rates of H. roretzi with various body sizes were calculated at different metal concentrations. Both clearance and oxygen consumption rate were negatively correlated with body sizes. Clearance rate of H. roretzi decreased gradually with increasing concentration of heavy metal, the decreasing rate was in an order of Cr>Cu>Zn. The oxygen consumption rate first increased at low metal concentration (below $100{\mu}g\;L^{-1}$) and then decreased rapidly with increasing metal concentrations. The decreasing rate was in an order of Cu>Cr=Zn. There was a trend that the clearance rate and oxygen consumption rate decreased drastically under a concentration of $400{\mu}g\;L^{-1}$, and then decreased smoothly when the metal ion concentration increased continually. So the oxygen consumption and clearance rate at a concentration of $400{\mu}g\;L^{-1}$ Cu could be thought as a suitable biological tool for exotoxicology analysis.

• 한국환경보건학회지
• /
• 제32권2호
• /
• pp.186-191
• /
• 2006

Metal contamination of medicinal herbs is of growing concern because of their potential adverse health effects. In this study, metal exposures were estimated and their potential health risks were preliminarily evaluated using available data including metal contamination levels and consumption estimates of herbal medicine in Korea. Consumption and contamination data of 34 medicinal herbs abundantly used in Oriental medicine in Korea were used in this study. Lead, mercury, arsenic, cadmium, cobalt, and chrome were identified as contaminants of potential health concerns. Even based on a conservative exposure scenario, i.e., consuming 5 times more herbal medicine with 95th percentile contamination levels, health risks associated with herbal medicine consumption were estimated to be minuscule. Herbal consumption was 0.3% of the provisional tolerable daily intake levels recommended by Joint Expert Committee on Food Additives (JECFA) of WHO/FAO. However, it should be noted that there are several important assumptions and uncertainties associated with this evaluation: This study was conducted for only 34 types of medicinal herbs of which consumption and metal contamination data were available. In addition, there are no reliable herbal medicine consumption data among Korean population. The pattern and amount of herbal (medicine) consumption in Korea need to be investigated in order to conduct more refined risk assessment associated with metal contamination in medicinal herbs.

• 한국환경보건학회지
• /
• 제36권1호
• /
• pp.14-19
• /
• 2010

Based on a nationwide survey of the consumption of oriental medicine by the Korean population, we estimated the potential risk from the inadvertent ingestion of heavy metals such as Pb, Hg, As, and Cd as a result such consumption. Compared to the provisional daily intake limit, heavy metal intake through oriental medicine resulted in hazard quotients of less than one. The upper $90^{th}$ percentile exposure estimates for each metal also showed insignificant risk. In relation to inorganic forms that are known carcinogens the excess cancer risk was less than $1{\times}10^7$. Based on the results of this study exposure to Pb, Hg, As, or Cd through oriental medicine intake appeared to be negligible and would not cause a significant impact on health.

• 한국정보디스플레이학회:학술대회논문집
• /
• 한국정보디스플레이학회 2005년도 International Meeting on Information Displayvol.I
• /
• pp.609-613
• /
• 2005

Advanced mobile communication devices require a bright, high information content display in a small, light-weight, low power consumption package. In this paper we will outline our progress towards developing such a low power consumption active-matrix flexible OLED ($FOLED^{TM}$) display. Our work in this area is focused on three critical enabling technologies. The first is the development of a high efficiency long-lived phosphorescent OLED ($PHOLED{TM}$) device technology, which has now proven itself to be capable of meeting the low power consumption performance requirements for mobile display applications. Secondly, is the development of flexible active matrix backplanes, and for this our team are employing poly-Si TFTs formed on metal foil substrates as this approach represents an attractive alternative to fabricating poly-Si TFTs on plastic for the realization of first generation flexible active matrix OLED displays. Unlike most plastics, metal foil substrates can withstand a large thermal load and do not require a moisture and oxygen permeation barrier. Thirdly, the key to reliable operation is to ensure that the organic materials are fully encapsulated in a package designed for repetitive flexing. We also present progress in operational lifetime of encapsulated T-PHOLED pixels on planarized metal foil and discuss PHOLED encapsulation strategy.

• 한국자동차공학회논문집
• /
• 제9권3호
• /
• pp.35-41
• /
• 2001

In recent applications, map controlled thermostat has been adapted to optimize engine cooling system and vehicle cooling system. First of all, this strategy is focused on improving fuel consumption rate and reducing emissions, especially unburned hydrocarbon. The object can be obtained through controlling engine metal temperature by varying engine coolant temperature with engine load and speed. To achieve this goal, it is necessary to understand the characteristics of engine metal temperature and heat rejection rate to coolant. From the results of tested engines, it is obvious that fuel consumption rate has more dominant effect on engine metal temperatures than the corresponding engine power does. Also, Re-Nu relation which shows heat rejection rate to coolant in function of air-fuel mixture and engine specifications has been studied. Also, the empirical Re-Nu relation at full loaded engine was developed.

• 한국포장학회지
• /
• 제11권2호
• /
• pp.109-114
• /
• 2005

This paper introduces the current status of total overseas packaging industries. The total market of the world packaging industry reached over 500 billion dollars in 2002. The top nations for the packaging industry were U.S. at about 27 percent, the countries of Western Europe at about 27%, Japan at about 14%. In terms of packaging materials, the overall market rate for paper, plastics, and metal parts in world packaging industry was 84%. Also, the market rate of glass, packaging machine, and others was only 5-6%. Among EU nations, Germany showed largest packaging consumption of 23 percent in 2000, and consumed about 17,125,814 ton of packaging materials yearly. For paper and paperboard cartons, the percentage used for the packaging consumption was about 39.4%. The consumption rate of plastic and glass packaging was approximately 14.6% and 23.7% respectively. For metal packaging the consumption rate was about 5.9%. In Japan, the production rate of packaging materials was decreased slowly at paper, metal, glass, and wood areas, but plastic packaging showed a constant rate of growth. In China, total production of packaging industry amounted to about 33.7 billion in 2003. The paper packaging in china was a remarkable production rate of 32%. The production rate of plastic and printing packaging was 28% and 20% respectively. The rate of packaging industry for printing in China was much higher than that in other countries.

• 자원리싸이클링
• /
• 제19권6호
• /
• pp.11-26
• /
• 2010

일본의 도시광산자원과 금속재자원화산업을 파악하기 위하여, 일본(日本)의 금속소비량, 금속리싸이클리률을 논하고, 철스크랩, 사용이 끝난 자동차, 폐가전제품 및 폐전자정보기지 등의 대표적인 재자원화산업의 개요를 조사하였다. 일본은 금속자원 소비대국이고 각종 금속 축적량 대국이기도 하다. 도시광산자원의 리싸이클링률은 자급률로 계산할 때 Pb 50%, Fe 33%, Al 25%이고, Hg, Au, Cd, Mn, Mo, Ag 등이 이어지고 있다. 그러나 기능재료에 첨가되는 레어메탈 및 REE 등은 리싸이클링 기술개발 단계라고 할 수 있다. 자동차, 가전제품 PC 등 사용이 끝난 제품의 리싸이클링산업은 활발하고, 리사이클링률은 법정기준치를 상회하고 있다.

• 대한전자공학회:학술대회논문집
• /
• 대한전자공학회 2006년도 하계종합학술대회
• /
• pp.503-504
• /
• 2006

This paper presents the design and fabrication of a LC voltage-controlled oscillator (VCO) using 1-poly 6-metal mixed signal CMOS process. To obtain the high-quality factor inductor in LC resonator, patterned-ground shields (PGS) is placed under the symmetric inductor to reduce the effect from image current of resistive Si substrate. Moreover, due to the incapability of using thick top metal layer of which the thickness is over $2{\mu}m$, as used in many RF CMOS process, the structure of dual-metal layer in which we make electrically short circuit between the top metal and the next metal below it by a great number of via materials along the metal traces is adopted. The circuit operated from 2.63 GHz to 3.09 GHz tuned by accumulation-mode MOS varactor. The corresponding tuning range was 460 MHz. The measured phase noise was -115 dBc/Hz @ 1MHz offset at 2.63 GHz carrier frequency and the current consumption and the corresponding power consumption were about 2.6 mA and 4.68 mW respectively.

• 전기학회논문지
• /
• 제57권4호
• /
• pp.660-667
• /
• 2008

To improve the luminous efficacy of PDPs, an AC PDP with new metal electrode structure is suggested. Operating voltage margin, power consumption, luminance, luminous efficacy, addressing jitter and ICCD image of test panel with proposed structure are measured, to compared with performances of the conventional ITO structure and proposed structures. To enhance luminous efficacy, we designed new structure which have asymmetric metal electrode structure. The experimental results show that the suggested structure shows luminance to maximum 89% and luminous efficacy to maximum 107% compared with conventional ITO standard structure. In addition, proposed structures with asymmetric electrode show low power consumption by $2{\sim}3%$, high luminance by $5{\sim}7%$, and high luminous efficacy by $2{\sim}3%$ compared with proposed symmetric electrode structures.

• 자원리싸이클링
• /
• 제19권5호
• /
• pp.13-24
• /
• 2010

도시광산(사용후제품) 재자원화의 필요성과 배경을 설명하기 위하여, 자원고갈, 금속지원의 소비, 환경오염 그리고 금속재자원화 산업 등을 논하였다. 지속가능한 사회를 개발하기 위해서는 폐기물처리와 리싸이클링이 가장 중요한 과제이고, 특히 도시광산을 재자원화하는 것이 자원고갈을 지연시키고, 환경오염을 감소시키는 첩경임을 잘 알고 있다. 그러기 위해서는 도시광산지원의 재자원화 제도의 구축과 고도의 재자원화 기술개발이 시급한 과제라고 할 수 있다.