• 한국환경복원기술학회지
• /
• 제18권2호
• /
• pp.53-64
• /
• 2015

Rooftop greening is the alternative of urban heat island. The purpose of this study is selecting Sedum to the effect of temperature reduction of the rooftop greening. Since the state of growth is excellent, Sedum kamtschaticum, Sedum takesimense and Sedum middendorffianum surveyed as coverage. It was investigated that there is the effect of reducing the temperature. The effect of temperature reduction of Sedum counted compound was found to be associated with state of growth. When you construct a rooftop greening, planting Sedum kamtschaticum, Sedum takesimense and Sedum middendorffianum is helpful to the effect of temperature reduction. Also, the ingredients various types of Sedum in order to reduce the effective temperature, it must be densified. It must demonstrate an additional effect of temperature reduction of Sedum through complementary and continuous monitoring of the future temperature monitoring method.

• 한국농림기상학회지
• /
• 제14권2호
• /
• pp.63-70
• /
• 2012

지구온난화 현상과 관련하여 온도 상승에 따른 수목의 초기 생리 반응 변화를 이해하기 위하여, 일본잎갈나무와 거제수나무 유묘를 $24^{\circ}C$와 $27^{\circ}C$에서 4주간 키운 후, 이들의 생장, 광색소 함량, 항산화효소 활성 및 MDA 함량을 조사 분석하였다. 높은 온도($27^{\circ}C$)에서 생장한 두 수종의 수고 상대생장률은 대조구에 비해 낮았으며, 잎, 줄기, 뿌리의 건중량도 모두 낮았다. 특히 뿌리의 생장 감소는 시간이 지나면서 뚜렷하게 증가하였으며, 이로 인해 지상부와 지하부의 비는 높은 온도에서 증가하였다. 광색소 함량은 두 수종 모두 온도 증가로 감소하였으며, 항산화효소인 APX와 CAT의 활성은 높은 온도에서 증가하였다. 그러나 MDA 함량은 온도 변화에 영향을 받지 않았다. 결론적으로, 수목의 생육 온도 증가는 생육 초기에 뿌리의 생장을 감소시켜 양료 흡수를 제한하며, 엽록소 함량 감소와 지상부의 생장을방해할 수 있다. 또한 온도 증가는 수목의 생장 기간 동안 스트레스 요인으로 작용하여 에너지의 소모를 증가시켜 생장 감소를 초래할 수 있다.

• Applied Science and Convergence Technology
• /
• 제24권6호
• /
• pp.262-267
• /
• 2015

We demonstrate the growth of single-walled carbon nanotubes (SWNTs) using ethylene-based chemical vapor deposition (CVD) and ferritin-induced catalytic particles toward growth temperature reduction. We first optimized the gas composition of $H_2$ and $C_2H_4$ at 500 and 30 sccm, respectively. On a planar $SiO_2$ substrate, high density SWNTs were grown at a minimum temperature of $760^{\circ}C$. In the case of growth using nanoporous templates, many suspended SWNTs were also observed from the samples grown at $760^{\circ}C$; low values of $I_D/I_G$ in the Raman spectra were also obtained. This means that the temperature of $760^{\circ}C$ is sufficient for SWNT growth in ethylene-based CVD and that ethylene is more effective that methane for low temperature growth. Our results provide a recipe for low temperature growth of SWNT; such growth is crucial for SWNT-based applications.

• Journal of Microbiology and Biotechnology
• /
• 제20권3호
• /
• pp.615-621
• /
• 2010

The viability of low-temperature sulfate reduction with hydrogen as electron donor was studied with a bench-scale gas-lift bioreactor (GLB) operated at $9^{\circ}C$. Prior to the GLB experiment, the temperature range of sulfate reduction of the inoculum was assayed. The results of the temperature gradient assay indicated that the inoculum was a psychrotolerant mesophilic enrichment culture that had an optimal temperature for sulfate reduction of $31^{\circ}C$, and minimum and maximum temperatures of $7^{\circ}C$ and $41^{\circ}C$, respectively. In the GLB experiment at $9^{\circ}C$, a sulfate reduction rate of 500-600 mg $l^{-1}d^{-1}$, corresponding to a specific activity of 173 mg ${SO_4}^{2-}g\;VSS^{-1}d^{-1}$, was obtained. The electron flow from the consumed $H_2$-gas to sulfate reduction varied between 27% and 52%, whereas the electron flow to acetate production decreased steadily from 15% to 5%. No methane was produced. Acetate was produced from $CO_2$ and $H_2$ by homoacetogenic bacteria. Acetate supported the growth of some heterotrophic sulfate-reducing bacteria. The sulfate reduction rate in the GLB was limited by the slow biomass growth rate at $9^{\circ}C$ and low biomass retention in the reactor. Nevertheless, this study demonstrated the potential sulfate reduction rate of psychrotolerant sulfate-reducing mesophiles at suboptimal temperature.

• 산업기술연구
• /
• 제39권1호
• /
• pp.7-14
• /
• 2019

Carbon nanotubes (CNT) on metal substrates are definitely beneficial because they can maintain robust mechanical stability and high conductivity between CNT and metal interfaces. Here, we report direct growth of CNT on Ni-based superalloy, Inconel 600, using thermal chemical vapor deposition (CVD) with acetylene feedstock in the growth temperature range of $400-725^{\circ}C$. Furthermore, we studied the effect of substrate pretreatment on the growth yield enhancement and growth temperature decrease of CNT on Inconel 600. Activation energy (AE) for CNT growth was estimated from the CNT height change with respect to the growth temperature. The AE values significantly decreased from 205.03 to 24.35 kJ/mol by the pretreatment of thermal oxidation of Inconel substrate at $725^{\circ}C$ under ambient. Higher oxidation temperature tends to have lower activation energy. The results have shown the importance of pretreatment temperature on CNT growth yield and growth temperature decrease.

• Membrane and Water Treatment
• /
• 제10권1호
• /
• pp.39-44
• /
• 2019

LID facilities do not consider environmental factors, and due to inappropriate vegetation planting causing degradation in efficiency due to plant damage and difficulty in maintenance. Therefore, in this study, assessment of impact environmental factor by seasonal variation of chlorophyll and growth of vegetation planted in LID technologies and change of pollutant reduction were conducted. In the case of B-SJ and B-RI, growth rate decreased after summer (August), and B-MG showed steady growth until autumn (September). Chlorophyll was found to increase during spring season while it decreased during autumn season. The chlorophyll concentration was found to affect the plant growth pattern. TN reduction efficiency was highest with greater than 80% efficiency in summer, and it was analyzed that plants were identified as the main factor affecting the seasonal reduction efficiency of TN. Also, temperature and relative humidity were analyzed to affect plant growth, activity and pollutant removal efficiency. Plant type and growth pattern are considered as factors to be considered in selection of appropriate plant types in LID technologies.

• 한국결정성장학회지
• /
• 제13권3호
• /
• pp.117-121
• /
• 2003

염화 니켈과 마그네슘 스테아린산 혼합 분말로부터 수소환원 공정에 의하여 니켈 분말을 제조하고 반응온도 및 마그네슘스테아린산의 첨가에 따른 분말의 특성을 검토하였다. 마그네슘 스테아린산을 함유한 경우 과도한 입자 성장의 억제로 인하여 입경 감소 효과가 있었다. 마그네슘 스테아린산의 함유량이 증가함에 따라 이에 따른 액상량의 증가로 인하여 입경 감소와 입자들간의 응집 정도에도 영향을 주었다.

• 한국결정성장학회지
• /
• 제6권3호
• /
• pp.415-423
• /
• 1996

황산니켈염 수용액에서 가압수소환원법을 이용하여 알루미나 분말상에 니켈 코팅층을 형성하기 위하여 실험조건(수소분압, 반응온도, $PdCl_{2}$ 첨가량, 알루미나의 종류 및 입도)을 변화시키면서 니켈이온의 환원속도 및 석출상태를 조사하였다. 환원온도 $165^{\circ}C$, 수소분압 300 psi, 코팅촉매제 $PdCl_{2}\;2\;mg/\ell$를 첨가한 조건에서 균질한 니켈코팅층을 얻을 수 있었다.

• Ocean and Polar Research
• /
• 제37권3호
• /
• pp.201-209
• /
• 2015

To examine the effects of increased $CO_2$ concentration and seawater temperature on the photosynthesis and growth of forest forming Ecklonia cava (Laminariales, Phaeophyta), sporophytic discs and gametophytes were cultured under three $pCO_2$ concentrations (380, 750, 1000 ppm), four temperatures (5, 10, 15, $20^{\circ}C$ for sporophytes; 10, 15, 20, $25^{\circ}C$ for gametophytes), and two irradiance levels (40, $80{\mu}mol$ photons $m^{-2}s^{-1}$) for 5 days. Photosynthetic parameter values ($ETR_{max}$, $E_k$, and ${\alpha}$) were generally higher as sporophytic discs were grown under low temperature and increased $CO_2$ concentration at 750 ppm. However, photosynthesis of Ecklonia sporophytes was severely inhibited under a combination of high temperature ($20^{\circ}C$) and 1000 ppm $CO_2$ concentration at the two photon irradiance levels. The growth of gametophytes was maximal at the combination of 380 ppm (present seawater $CO_2$ concentration) and $25^{\circ}C$. Minimal growth of gametophytes occurred at enriched $pCO_2$ concentration levels (750, 1000 ppm) and high temperature of $25^{\circ}C$. The present results imply that climate change which is increasing seawater temperature and $pCO_2$ concentration might diminish Ecklonia cava kelp beds because of a reduction in recruitments caused by the growth inhibition of gametophytes at high $pCO_2$ concentration. In addition, the effects of increased temperature and $pCO_2$ concentration were different between generations - revealing an enhancement in the photosynthesis of sporophytes and a reduction in the growth of gametophytes.

• 한국전기전자재료학회논문지
• /
• 제28권8호
• /
• pp.531-538
• /
• 2015

This study examined the size and shape of the nano-silver particle through the analysis of electrical resistance when synthesizing nano-sized silver by using the chemical liquid reduction. Changes in particle behaviors formed according to the changes in electronic characteristics by electric resistance in each time period in the beginning of reduction reaction in a course of synthesizing the nano-silver particle formation were studied. In addition, analysis was conducted on particle behaviors according to the changes in concentration of $AgNO_3$ and in temperature at the time of reduction and nucleation and growth course when synthesizing the particles based on the particle behaviors were also examined. As the concentration of $AgNO_3$ increased, the same amount of resistance of approximately $5{\Omega}$ was increased in terms of initial electronic resistance. Furthermore, according to the result of formation of nuclear growth graph and estimation of slope based on estimated resistance, slops of $6.25{\times}10^{-3}$, $2.89{\times}10^{-3}$, and $1.85{\times}10^{-3}$ were derived from the concentrations of 0.01 M, 0.05 M, and 0.1 M, respectively. As the concentration of $AgNO_3$ increased, the more it was dominantly influenced by the nuclear growth areas in the initial phase of reduction leading to increase the size and cohesion of particles. At the time of reduction of nano-silver particle, the increases of initial resistance were $4{\Omega}$, $4.2{\Omega}$, $5{\Omega}$, and $5.3{\Omega}$, respectively as the temperature increased. As the temperature was increased into $23^{\circ}C$, $40^{\circ}C$, $60^{\circ}C$, and $80^{\circ}C$, slopes were formed as $4.54{\times}10^{-3}$, $4.65{\times}10^{-3}$, $5.13{\times}10^{-3}$, and $5.42{\times}10^{-3}$ respectively. As the temperature increased, the particles became minute due to the increase of nuclear growth area in the particle in initial period of reduction.