• 보존과학연구
• /
• 통권30호
• /
• pp.47-61
• /
• 2009

Cultural heritages are affected by various environmental factors. Main factors are temperature, humidity, light and indoor air pollutants such as ozone, nitrogen oxides. Especially humidity condition is very important. Low humidity condition can cause contraction and high humidity condition can lead to growth of microorganism. This study is conducted to appraise an applicability of the Humidity Indicator which is one of the simple method for humidity control. The Humidity Indicator shows the humidity conditions through color change. Therefore, photometer was used to correctly measure the color change of Humidity Indicator. As a result of lab test, Humidity Indicators was stabilized after one hour from en exposure in a certain humidity condition and the indicators indicated clear correlations between color changes of Humidity Indicators and humidity conditions. Some Humidity Indicators which had been selected through the lab tests were applied to preservation facilities of cultural heritages and the indicators indicated closed correlations with humidity conditions in indoor of facilities.

• 한국대기환경학회지
• /
• 제30권5호
• /
• pp.504-509
• /
• 2014

Twenty-five stations of the urban monitoring network in Seoul were assessed with a focus on surveillance function of the exceedances of 8-hour ozone and 24-hour $PM_{10}$ standards. The two standards were selected because their attainment rates were particularly low. Two hierarchical cluster analyses were performed to group stations with similar atmospheric environments-one using daily highest 8-hour [$O_3+NO_2$], 8-hour $O_3$ concentrations plus corresponding 8-hour $NO_2$ concentrations considering the interconversion of $O_3$ and $NO_2$, and the other using 24-hour $PM_{10}$ concentrations. An index to measure higher concentration and exceedances of the standards was introduced. Within a cluster, sufficiently high score was assigned to the trends station or the station with higher index. Scores for $O_3+NO_2$ and $PM_{10}$ of a given station were added and ranked in the descending order to determine the relative importance.

• 한국대기환경학회지
• /
• 제12권1호
• /
• pp.91-99
• /
• 1996

Ozone, sulfur dioxide, and nitrogen oxides were measured at Kosan, Cheju Island, Korea during the period of March 11 .sim. April 19, 1994. During the measurement period, the average SO$_{2}$ and NOx concentrations were about 0.97 ppb and 3.5 ppb, respectively. Average NO concentration was below the detection limit and thus the effect of NO during the period was negligible. The concentrations of SO$_{2}$ and Nox were lower than those at other urban area in Korea but higher than other remote areas in the world. Average $O_{3}$ concentration for the period was about 55 ppb, slightly higher than or comparable to those at remote marine areas in the world. Detailed analyses of trend of gaseous species concentrations show that the effects of local NO emission sources for NOx concentration were significant during the period, while those of local SO$_{2}$ emission sources were not high. Backward trajectory analysis results show that when SO$_{2}$ or $O_{3}$ concentration was higher than the average concentrations, the air parcels were transported from China.

• 한국전기전자재료학회논문지
• /
• 제19권11호
• /
• pp.1044-1049
• /
• 2006

We reported on characteristics of the fluorescent OLED fabricated on commercial ITO/glass and BCS grown IZO/glass substrate, respectively. The amorphous IZO anode film grown by box cathode sputtering(BCS) exhibited similar electrical and optical characteristics to commercial ITO anode even though it was deposited at room temperature. In addition, the amorphous IZO anode showed higher workfunction (5.2 eV) than that of the commercial ITO anode (5.0 eV) after ozone treatment for 10 min. Furthermore, fluorescent OLED fabricated on amorphous IZO anode film showed improved current-voltage-luminance characteristics, external quantum efficiency and power efficiency en contrast with fluorescent OLED fabricated on commercial ITO anode film. It was thought that smooth surface and high workfunction of amorphous IZO anode lead to more efficient hole injection by reduction of interface barrier height between anode and organic layers.

• 설비공학논문집
• /
• 제8권1호
• /
• pp.140-150
• /
• 1996

CFC-12, which has been used most widely in automobile air conditioners and household refrigerators is scheduled to be phased out soon because of its high ozone depletion potential. Now HFC-134a is suggested as an alternative refrigerant for CFC-12. In this Study, we intended to investigate how PAG oil influence evaporation heat transfer and flow pattern, using R-134a and PAG oil influences evaporation heat transfer and flow pattern, using R-134a and PAG oil in the horizontal miro-fin evaporation tube. Experiments were conducted under the flowing est conditions : mass velocity 86-250kg/$m^2$s, heat flux 5-30 ㎾/$m^2$, oil concentration 0-21 wt.% and saturation temperature 5$^{\circ}C$. Local evaporation heat transfer coefficients were found to be higher at the top, side and bottom of the tube in this order. Average heat transfer coefficients turned out to increase with oil concentration increment up to 3 wt.% oil concentration, whereas heat transfer coefficients gradually decreased over 3 wt.% oil concentration, because of oil-rich liquid film was formed on the heat transfer surface. Flow patterns were rapidly transitioned to annular regimes up to 3 wt.% oil concentration. In case of pure refrigerant, measured heat transfer coefficients in the experiments were similar to those of Kandlikar＇s correlation.

• Elastomers and Composites
• /
• 제33권3호
• /
• pp.159-167
• /
• 1998

고무제품의 노화는 인간의 노화 처럼 오존, 자외선, 산소 등의 작용에 의하여 매우 복잡하게 진행된다. 노화에 대한 이해는 매우 중요하나 너무나 복잡하기 때문에 이에 대한 논문이 매우 드물다. 본문에서는 EPDM과 천연고무의 노화거동을 이해하고자 하였고 가황물과 과산화물 가교물의 노화거동을 서로 비교하여 보았다. 실험결과 파산화물에 의한 가교물이 황에 의한 가교물보다 노화면에서는 좋게 나타났다. 저자는 본 연구가 고기능성 고무 제품을 제조하는데 도움이 되리라 믿는다.

• 한국환경과학회지
• /
• 제24권6호
• /
• pp.807-817
• /
• 2015

In this study the urban atmospheric environment map in Busan was made and it consist of the atmospheric environment element map and the atmospheric environment analysis map. The atmospheric environment element map covered the topography, the urban climate, the air pollutant emission, ozone and PM10 concentrations in Busan and the atmospheric environment analysis map included the thermal environment and the wind flow by using WRF meteorological numerical simulation. The meteorological elements from 2007 to 2011 in Busan were used in this study. As a result, in the center of Busan and Buk-gu along to the Nakdong river was the temperature high. To analyze the air flow of Busan 3 clusters depending on the wind direction were extracted with the cluster analysis. The results of the analysis on the detailed wind field of each cluster showed that the weak ventilation could be happened locally at the specific meteorological condition.

• 한국공작기계학회논문집
• /
• 제14권4호
• /
• pp.69-74
• /
• 2005

Nowadays CFC and HCFC refrigerants are restricted because they causes to depletion of ozone layer. Accordingly, an experiment is apply to the $NH_3$ gas for refrigerant to study the performance characteristic and to improve the energy efficiency. An experiment are carried out for the condensed pressure in a range from 14.5bar to 16bar and for degree of superheat in a range from 0 to $10^{\circ}C$ at each condensed pressure. As the result of experiment, when degree of superheat is $1^{\circ}C$ and condensed pressure is 14.5bar, the refrigeration system showed the high performance.

• Plant Resources
• /
• 제8권1호
• /
• pp.52-59
• /
• 2005

A cDNA, PSOD1, encoding cytosolic copper/zinc superoxide dismutase (CuZn-SOD) was cloned and characterized from a full length cDNA library prepared from Populus alba${\times}$Populus glandulosa cultured in vitro. A PSOD1, is 725 nucleotides long and has an open reading frame of 459 bp with 152 amino acid residues (pI 5.43). The deduced amino acid sequence of PSOD1 perfect matched to the previously reported CuZn-SOD (CAC33845.1). Consensus amino acid residues (His-45, -47, -62, -70, -79, -119) were involved in Cu-, Cu/Zn-, and Zn- binding ligands. The deduced amino acid sequence of PSOD1 exhibited the high level of similarity from 100 to $85\%$ among previously registered SOD genes. The expression of PSOD1 in poplar increased at the 1 mM $H_{2}O_2$ and drought stress during 30 min and 60 min, but the ozone treated poplar increased at 30 min in the early time and then decreased at 60 min.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2000년도 하계학술대회 논문집
• /
• pp.779-782
• /
• 2000

Silicone rubbers are first silicone polymers and has named silicone from existence of Si-O bond similar to Keton. Silicon in organic compound has been called silicone, and linear or network polymers. Silicone rubbers have been used as an power insulator because they are well weather proof, ozone proof and have excellent electric characteristics, thermal stability, cold resistance and low surface energy. Especially, it is known that they have very excellent characteristics at 200[$^{\circ}C$]. For this study, we made silicone rubbers as specimens and we measured dielectric loss tangent due to applied voltage at temperature range 25[$^{\circ}C$] to 180[$^{\circ}C$] and frequency range 20[Hz] to 1${\times}$10$\^$6/[Hz] to examine dielectric properties. We measured dielectric loss tangent to study the insulation performance of silicone rubbers.