• Bulletin of the Korean Chemical Society
• /
• 제30권12호
• /
• pp.2921-2926
• /
• 2009

Cu-BTC[$Cu_3(BTC)_2(H_2O)_3$, BTC = 1,3,5-benzenetricarboxylate], one of the most well-known metal-organic framework materials (MOF), has been synthesized under atmospheric pressure and room temperature by using ultrasound. The Cu-BTC can be obtained in 1 min in the presence of DMF (N,N-dimethylformamide), suggesting the possibility of continuous production of Cu-BTC. Moreover, the surface area and pore volume show that the concentration of DMF is important for the synthesis of Cu-BTC having high porosity. The morphology and phase also depend on the concentration of DMF : Cu-BTC cannot be obtained at room temperature in the absence of DMF and aggregated Cu-BTC (with low surface area) is produced in the presence of high concentration of DMF. It seems that the deprotonation of benzenetricarboxylic acid by base (such as DMF) is inevitable for the room temperature syntheses.

• 한국연소학회지
• /
• 제15권1호
• /
• pp.30-37
• /
• 2010

Carbonization characteristics of Indonesian bamboos were investigated using lab-scale tube furnace, in order to find optimum design temperature of a carbonizer for producing bamboo charcoal and vinegar. The bamboo samples used in this study are local bamboos from Damyang in Korea, Andong and Petung in Indonesia. Correlation of electric resistance, specific surface area and pH of bamboo vinegar with pyrolysis temperature has been investigated. Electric resistance of the charcoal increased for higher pyrolysis temperature the specific surface area was also increased as carbonization temperature got higher. Charcoal which has specific surface area of over $300\;m^2/g$ could be produced at $700^{\circ}C$. pH of bamboo vinegar was decreased for highter carbonization temperature and vinegar under pH 3 could be produced for all bamboo samples. In this experimental condition, it was found that lower carbonization temperature is better for producing bamboo vinegar of high quality, while higher temperature is better for obtaining bamboo charcoal with larger surface.

• 아시안잔디학회지
• /
• 제3권1호
• /
• pp.24-33
• /
• 1989

This study was conducted to investigate the effect of paclobutrazol [(2 RS , 3 RS )1-(4- chlor-ophenyl )-4, 4- dimethyl -2- (1, 2, 4- triazol -1- yl )- pentan -3-01] on the tolerance of hi-gh temperature and drought stress as related to growth retardation , iranspiration rate , soil water content , nitrogen level and photosynthetic rate in perennial ryegrass ( Loliurn perenne L . ' Omega H , ). Plants were given a 30 ml soil drench of paclohutrazol at the concentrations of 0, 0.01, 0.1, 1.0, 10.. 0, mg / 6 .5cm- diameter pot . The rcsults were as follows : 1. Increasing concentrations of paclohutrazul reduced plant height , leaf area , fresh weight and dry weight , hut increased chlorophyll content per unit area . The number of tillers and leaf width were not affected hy the paclobutrazol concentrations . 2. The proper concentration of paclohatrazol on growth retardation in perennial ryegrass was about I mq /pot , hut leaf deformity and severe growth retardation were shown at high concentration of 10 mq / pot . 3. Perennial ryegrasses grown at 30˚C were shown significantly short plant height and low leaf nitrogen level compared with those grown at 20˚C. Increasing concentrations of paclohutrazol at 20˚C increased nitrogen level hut it could not increase nitrogen level at 30˚C . 4. During the drought stress , increasing temperatures significantly promoted transpiration rate and wilting time . It took about 5 days at 20˚C and 3 days at 30˚C to reach wilting time of leaves from water stress treatment . Soil water contents at wilting time of non-treated controls were averaged 6. 871% at 20˚C and 6. 17% at 30˚C 5. Paclohutrazol reduced transpiration rate at high temperature and drought stress . Wilting appeared at the lower water content of soil according to increasing concentrations of paclobutrazol at 30˚C hut there were no differences among concentrations of at 20˚C. 6.Paclohutrazol treatment at 1 rag /pot reduced injury rate of leaves from 67.1 % and 100 % in control plants to 15.7% and 80% at 20˚C and 3010, respectively. 7. Photosynthetic rate per unit area was significantly reduced at high temperature . Paclohutrazol stimulated photosynthetic rate with increase of concentrations at 20˚C but there was no increasing effect at 30˚C.

• 대한간호학회지
• /
• 제43권1호
• /
• pp.30-38
• /
• 2013

Purpose: The study was done to explore variations in physiologic parameters of the stratum corneum (SC) of the dorsal hand and cord area during early days of life in high-risk newborns. Methods: In this longitudinal study, a total of 77 high-risk newborns were assessed for pH, temperature and hydration of the SC of the dorsal hand and the cord area on the $1^{st}$, $2^{nd}$, $3^{rd}$, $5^{th}$ and $7^{th}$ days of life. Results: Results showed that an acid mantle (AM) was formed in 57.1% for dorsal hand and 35.1% for cord area, implying significant delay regardless of decrease in pH (F=103.60, p<.001), and hydration (F=4.00, p=.003) across days in both areas. Peripheral hypothermia with low hydration level was also observed in both areas. There was a positive relation between hydration and temperature (.14

• 대기
• /
• 제29권2호
• /
• pp.183-196
• /
• 2019

High-quality and high-resolution meteorological information is essential to reduce damages due to disastrous weather phenomena such as flash flood, strong wind, and heat/cold waves. There are many meteorological observation stations operated by Korea Meteorological Administration (KMA) in Seoul Metropolitan Area (SMA). Nonetheless, they are still not enough to represent small-scale weather phenomena like convective storm cells due to its poor resolution, especially over urban areas with high-rise buildings and complex land use. In this study, feasibilities to use additional pre-existing networks (e.g., operated by local government and private company) are tested by investigating the effects of network density on the gridded horizontal distribution of two meteorological variables (temperature and precipitation). Two heat wave event days and two precipitation events are chosen, respectively. And the automatic weather station (AWS) networks operated by KMA, local-government, and SKTechX in Incheon area are used. It is found that as network density increases, correlation coefficients between the interpolated values with a horizontal resolution of 350 m and observed data also become large. The range of correlation coefficients with respect to the network density shows large in nighttime rather than in daytime for temperature. While, the range does not depend on the time of day, but on the precipitation type and horizontal distribution of convection cells. This study suggests that temperature and precipitation sensors should be added at points with large horizontal inhomogeneity of land use or topography to represent the horizontal features with a resolution higher than 350 m.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 2009년도 하계학술대회 논문집
• /
• pp.214-215
• /
• 2009

This paper presents the fabrication and characteristics of microheaters, built on AlN(0.1 um)/3C-SiC(1 um) suspended membranes. Pt was used as microheater and temperature sensor materials. The results of simulated are shown that AlN/3C-SiC membrane has more large uniform-temperature area than $SiO_2$/3C-SiC membrane. Resistance of temperature sensor and power consumption of microheater were measured and calculated. Pt microheater generates the heat of about $550^{\circ}C$ at 340 mW and TCR of Pt temperature sensor is about 3188 ppm/$^{\circ}C$.

• 한국측량학회지
• /
• 제26권3호
• /
• pp.219-225
• /
• 2008

원자력 발전소의 주변 지역은 해안지역이고 비교적 광범위하므로, 환경 변화를 감시하는데 많은 어려움이 있다. Landsat ETM+영상은 해상도가 30m 급이나 온도정보 추출에 있어 대기보정을 못하는 문제를 가지고 있다. MODIS 영상의 경우 2개의 적외선 밴드를 이용하여 대기보정된 비교적 적확한 온도를 추출할 수 있으나 해상도가 1km이다. 따라서, 두 위성영상의 자료를 이용한다면 대기보정된 고해상도의 온도자료를 추출할 수 있다. 본 연구에서는 대상지역의 Landsat ETM+영상에 대하여 기하보정을 수행하고, 방사휘도 및 온도를 산정한 후 MODIS영상을 이용하여 대기보정을 수행하였다. 그 결과 울진 원자력발전소 주변 연근해 지역과 온배수의 영향을 받지 않는 동쪽으로 5km 떨어진 동일 면적의 지역과 비교하여 보았을 때 약 $3.5^{\circ}C$ 높은 것을 알 수 있었다.

• 대한지리학회지
• /
• 제48권1호
• /
• pp.37-55
• /
• 2013

기존의 푄 관련 선행연구에서는 크게 영서 지방에서 푄(Foehn)이 두드러지게 나타난다고 하였다. 그러나 영서 지방의 어디에서 두드러지게 나타나며 어떠한 분포양상을 보이는지에 대해서는 연구된 바가 없다. 본 연구는 영서 지방 중 홍천 지역을 대상으로 푄 발생 시의 일최고기온분포도 작성을 통해 국지적인 규모에서 푄의 빈도와 강도에 어떠한 차이가 나는지를 파악하고자 하였다. 연구대상기간은 2003년부터 2012년까지 봄에서 초여름(3~6월)이다. 기온과 해발고도를 변수로 한 공동크리깅(CoKriging)기법을 사용하였을 경우 푄 발생일의 일최고기온분포도 작성에 있어서 보다 높은 정확도를 나타내었다. 일최고기온분포도의 작성을 통해 푄은 홍천 전 지역에서 나타나는 것이 아니며 일부 지역에서만 나타나는 것을 확인하였다. 특히 홍천강 하류 지역에서 푄이 빈번하며 강도 또한 강함을 파악하였다. 홍천 지역 주민들의 푄 인식 정도에 대하여도 조사해 보았다. 봄철에 고온 건조함을 느끼지만 그것이 푄에 의한 것인지 인식은 하지 못하고 있었다. 본 연구의 국지기후 규모에서 푄을 분석하는 절차와 기법은 지역기후 이해와 연구분야에 기여 할 수 있을 것이며 특히 근래에 봄철부터 여름철에 두드러지게 나타나는 고온, 여름철 폭염, 봄철 농작물 생육 등과 관련하여 응용하여 적용할 수 있을 것이라 생각한다.

• 한국주조공학회지
• /
• 제34권5호
• /
• pp.170-178
• /
• 2014

Using the Gleeble test, the effects of [Mn/S] ratios and the presence of sulfides on the high-temperature fracture morphology of heavy-section steel castings were analysed via the observations of the microstructures. The specimens for which the [Mn/S] ratio was in the range of 60~80 showed a ductile fracture morphology with an area reduction of more than 60%, while some specimens with similar [Mn/S] ratios showed a brittle fracture morphology with an area reduction of 0.0% due to the liquidation of sulfides at the grain boundary. The fracture morphology was classified into three types in the Gleeble high-temperature tensile test specimens. The first type showed dimple formation at the grain boundary, the formation of globular MnS sulfides, and plastic deformation of sulfides at an elevated temperature, indicating a needle-point type of ductile fracture with area reductions of 96.0~97.8%. The second type was a knife-edge type brittle fracture with an area reduction of 0.0% due to the film-type liquidation of sulfides at the grain boundary, band-type liquidation, and the liquidation of a terraced nipple pattern. The third type was the typical ductile fracture with an area reduction of 31.3~81.0%, in accordance with the mixture of dimples with in the grains and terraced nipple pattern at the grain boundary.

• Composites Research
• /
• 제14권1호
• /
• pp.30-38
• /
• 2001

복합재료는 우수한 비강성, 비강도 특성 때문에 기존의 항공우주산업뿐만 아니라 로봇 팔. 공작기계 등에 널리 사용되고 있다. 복합재료 경화중의 온라인 모니터링기법은 생산성 향상 및 품질의 신뢰성 향상을 위하여 매우 중요한 연구분야로 대두되고 있다. 본 논문에서는 휘스톤 브리지식 유전회로를 설계하고 제작하였다. 또한 고온 경화 복합재료에 적용할 수 있는 고온 유전센서를 개발하여 그 성능을 평가하였다. 유한요소해석을 이용하여 유전 센서에 작용하는 열 잔류응력을 계산하였으며, 고온분위기 하에서 유전센서의 유전특성을 평가하였다. 이상에서 개발된 유전회로와 고온 유전센서를 이용하여 BMI(Blsmaleimlde) 수지의 경화모니터링을 수행하였다.