• Title/Summary/Keyword: $sc-CO_2$

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EFFICACY AND BIOLOGICAL ACTIVITIES OF A NEW ANTI-AGING AGENT OBTAINED FROM ARECA CATECHU

  • Lee, Kun-Kook;Lee, Kwang-Sik;Kim, Jeong-Ha;Jo, Byung-Kee;Choi, Jung-Do
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.24 no.3
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    • pp.24-30
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    • 1998
  • Inhibitory effects of the new material obtained from Areca catechu seed (CC-516) according to a special process, and its applicability to the skin as a cosmetic raw material in terms of its efficacy were presented. Areca catechu extract out of 150 medicinal plants, exhibited high inhibitory effect on the porcine pancreatic elastase ($IC_{50}$ : $40.8{\mu}$g/ml). It also had an inhibitory effect on the human leukocyte elastase ($IC_{50}$ : 48.1$\mu$g/ml), hyaluronidase ($IC_{50}$ : $416{\mu}$g/ml), antioxidative activity ($IC_{50}$ : $45.4\mu$g/ml) and free radical scavenging activity ($SC_{50}$ : $10.2{\mu}$g/ml). The cream contained 3% of CC-516 improved skin hydration above 16.5%. Especially, the skin elasticity increases more than 35% and skin wrinkles decreased more than 23%. The CC-516 was designed to be utilized in cosmetology. The cream containing 3% of this product has not only protecting effect on the skin mechanical properties provided by the collagen and the elastin in the derm but also restructuring effect of scarring or aging tissue.

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The Effect of Variation of Design Parameters on the Flexural Behavior of UHPFRC Beams (UHPFRC 보 휨 거동에 대한 설계변수 변동의 영향)

  • Yang, In-Hwan;Kim, Kyung-Chul;Park, Ji-Hun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.2
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    • pp.138-145
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    • 2018
  • This paper studies the bending behavior of ultra-high-performance fiber-reinforced concrete (UHPFRC) beams focused on the effect of variation in major material design parameters such as tensile strength, elastic modulus of UHPFRC, and rebar ratio. Analytical results show that the variation in the range of ${\pm}20%$ in the tensile strength of UHPFRC causes the significant difference in ${\pm}8{\sim}9%$ of bending strength compared to the reference condition. The variation of elastic modulus in UHPFRC rarely causes the effect on the bending strength of the UHPFRC section, whereas causes the difference in the slopes of moment-curvature curves, indicating different bending stiffness of UHPFRC sections. For the rebar with yield strength of 400MPa, the bending strength of SC120f is increased by 30, 67, and 99% when the rebar ratio is 1.0, 1.5, and 20%, respectively, compared to the rebar ratio of 0.5%. Therefore, it is observed that the variation of rebar ratio significantly affects the difference in bending strength of UHPFRC beams. However, as the compressive strength of UHPFRC becomes greater, the effect of rebar ratio on the increase of bending strength is decreased.

Experimental Study on Heat Exchange Efficiency of Combined Well & Open-Closed Loops Geothermal System (지하수정호와 결합한 복합지열시스템의 열교환 효율에 대한 실험적 연구)

  • Song, Jae-Yong;Lee, Geun-Chun;Park, Namseo
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.5
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    • pp.43-50
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    • 2018
  • The temperature of underground water generally remains constant regardless of the season. therefore, it is possible to get plenty of energy if we use characteristics of underground water for both cooling and heating. This study evaluates efficiency of real size coaxial and U-tube type complex geothermal system which is combined with underground water well. This study also evaluates relative efficiency/adaptability through comparison with existing geothermal systems(vertical closed loop system, open loop system(SCW)). The heat exchange capacity of complex geothermal system according to temperature difference between circulating water and underground water shows very high significance by increasing proportionally. The temperature change of underground water according to injection energy, shows very high linear growth aspect as injection thermal volume heightens. As a result of evaluation of heat exchange volume between complex geothermal system and comparative geothermal system, coaxial type has 26.1 times greater efficiency than comparative vertical closed type and 2.8 times greater efficiency than SCW type. U-tube type has 26.5 tims greater efficiency than comparative vertical closed type and 2.8 times greater than SCW type as well. This means complex geothermal system has extremely outstanding performance.

Annual Intensities (2016-2017) Analysis of Energy Use and CO2 Emission by End Use based on Measurements of Sample Apartment Units (표본건물 계측에 의한 공동주택 세대에서의 용도별 에너지사용량 및 CO2 배출량 연간 원단위 (2016 - 2017) 분석)

  • Jin, Hye-Sun;Lim, Han-Young;Lee, Soo-Jin;Kim, Sung-Im;Lim, Jae-Han;Song, Seung-Yeong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.7
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    • pp.43-52
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    • 2018
  • In this study, annual site and primary energy use intensities (EUIs) and CO2 emission intensities (CEIs) per area by end use were estimated based on the measurement data from June 2016 to May 2017 of 50 sample apartment units in Seoul. In addition, estimated site EUIs by end use were compared to the U.S. Residential Energy Consumption Survey (RECS) 2009 data. Site EUIs by end use were found to be in the order of heating > electric appliance > domestic hot water > cooking > lighting > cooling > air movement. In the case of primary EUIs and CEIs by end use, electric appliance was found to be the largest. As results of comparison with the RECS 2009 data, it was found that site EUIs were very similar for heating, domestic hot water and electric appliance, etc., but slightly different for cooling. The number of sample apartment units will continue to increase until 2020 (total number of samples 200) and intensities data by end use will be continuously updated through continuous collection of measurement data.

Annual Intensities (2016-2017) Analysis of Energy Use and CO2 Emission by End Use Based on Measurements of Sample Office Building (표본건물 계측에 의한 업무시설에서의 용도별 에너지사용량 및 CO2 배출량 연간 원단위 (2016 - 2017) 분석)

  • Lim, Han-Young;Lim, Su-Hyun;Jin, Hye-Sun;Kim, Sung-Im;Lee, Soo-Jin;Lim, Jae-Han;Song, Seung-Yeong
    • Journal of the Architectural Institute of Korea Structure & Construction
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    • v.34 no.8
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    • pp.19-27
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    • 2018
  • In this study, annual site and primary energy use intensities (EUIs) and $CO_2$ emission intensities (CEIs) per area by end use were estimated based on the measurement data from June 2016 to May 2017 of 19 sample office buildings in Seoul. In addition, the estimated site EUIs by end use were compared to the U.S. Commercial Buildings Energy Consumption Survey (CBECS) 2012 data. Average site EUIs by end use were found to be in the order of electric appliance (typical floors) > heating > cooling > lighting > air movement > domestic hot water > vertical transportation > city water supply. In the case of primary EUIs and CEIs by end use, electric appliance was found to be the largest. As results of comparison with the CBECS 2012 data, it was found that the site EUIs were similar for heating, cooling, domestic hot water, and electric appliance, etc., but slightly different for lighting and air movement. The number of sample office buildings will continue to increase until 2020 (total number of samples 85) and intensities data by end use will be continuously updated through continuous collection of measurement data.

고이동도의 W-doped $In_2O_3$(IWO) 투명 전극을 이용한 유기태양전지 특성 분석

  • Kim, Jun-Ho;Kim, Han-Gi;Seong, Tae-Yeon
    • Proceedings of the Materials Research Society of Korea Conference
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    • 2012.05a
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    • pp.109.1-109.1
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    • 2012
  • 본 연구에서는 co-sputtering을 통한 $WO_3$$In_2O_3$ 타겟을 사용하여 $WO_3$ 파워에 따른 Tungsten(W)-doped $In_2O_3$ (IWO) 투명 전극의 전기적, 광학적, 구조적 특성을 연구하고 이를 활용한 유기태양전지(Organic Photovoltaics; OPVs)의 특성을 분석하였다. Tungsten의 doping 농도는 $WO_3$에 인가되는 Radio-frequency (RF) power를 5~30 W 까지 변화시켜 조절하였으며, Rapid Thermal Annealing (RTA) 후 열처리 공정을 통해 IWO 박막의 전기적, 광학적, 구조적 특성을 분석하였다. Hall measurement 및 UV/Vis spectrometry 분석을 통하여 가시광선 영역에서 80% 이상의 높은 투과율, $48\;cm^2\;V^{-1}\;s^{-1}$의 홀 이동도, 20 ${\Omega}/{\Box}$ 이하의 낮은 면저항과 $3.2{\times}10^{-4}\;{\Omega}-cm$의 비저항 값을 나타내었다. 최적화된 IWO 박막을 이용한 OPV 셀 특성은 fill factor(FF): 61.59 %, short circuit current($J_{SC}$): 8.84 $mA/cm^2$, open circuit voltage($V_{OC}$): 0.60 V, efficiency(PCE): 3.27 %로 ITO로 제작된 OPV 샘플과 비교하였을 때 ITO를 대체할 수 있는 고이동도의 새로운 투명 전극 재료로서의 가능성을 확인하였다.

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Fabrication and Electrochemical Characterization of LSM/GDC based Cathode Supported Direct Carbon Fuel Cells (직접탄소 연료전지용 LSM/GDC 공기극 지지체 제조 및 전기화학 특성 평가)

  • Ahmed, Bilal;Wahyudi, Wandi;Lee, Seung-Bok;Song, Rak-Hyun;Lee, Jong-Won;Lim, Tak-Hyoung;Park, Seok-Joo
    • Transactions of the Korean hydrogen and new energy society
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    • v.24 no.3
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    • pp.230-236
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    • 2013
  • In this study, successive coating and co-sintering techniques have been used to fabricate LSM/GDC based cathode supported direct carbon fuel cells. The porous LSM/GDC cathode substrate, dense, thin and crack free GDC and ScSZ layers as bi-layer electrolyte, and a porous Ni/ScSZ anode layer was obtained by co-firing at $1400^{\circ}C$. The porous structure of LSM/GDC cathode substrate, after sintering at $1400^{\circ}C$, was obtained due to the presence of GDC phase, which inhibits sintering of LSM because of its higher sintering temperature. The electrochemical characterization of assembled cell was carried out with air as an oxidant and carbon particles in molten carbonate as fuel. The measured open circuit voltages (OCVs) were obtained to be more than 0.99 V, independent of testing temperature. The peak power densities were 116, 195 and $225mWcm^{-2}$ at 750, 800 and $850^{\circ}C$, respectively.

Geochemistry of Trace and Rare Earth Elements from Coal-bearing Metapelites of the Ogcheon Supergroup at the Hoenam Area, Korea (회남지역(懷南地域)의 옥천누층군(沃川累層群)에 분포(分布)하는 탄질(炭質) 변성이질암(變成泥質岩)의 미량(微量) 및 희토류원소(稀土類元素) 지화학(地化學))

  • Lee, Hyun Koo;Lee, Chan Hee
    • Economic and Environmental Geology
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    • v.29 no.6
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    • pp.689-698
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    • 1996
  • The coal-bearing metapelites from the Hoenam area are interbedded within the Ogcheon Supergroup, which are composed mainly of graphite, quartz, muscovite and associated with trace amount of biotite, chlorite, pyrite, rutile and barite. Although the formation was mined for coal, and the contents of V, U and Mo are a higher grade in coal formations than the host metapelites. The ratios of Al/Na and K/Na in coal formation are very heterogeneous and wide range from 10.28 to 90.91 and from 3.73 to 36.60, respectively. The V content increase with increasing Al and Ba contents, but the U and Mo are not related with other elements. Those are suggested that controlled of mineral compositions in coaly metapelites due to substitution, migration and reequilibrium of elements by regional metamorphism. These coal formation were deposited in basin of marine environments and the REE of these rocks are not influenced with metamorphism and hydrothermal alterations on the basis of Al content versus La, La against Ce, the ratios of La/Ce (0.23 to 0.73) and Th/U (0.03 to 16.6). These rocks also show much variation in $La_N/Yb_N$ (0.53 to 14.19), Th/Yb (0.51 to 6.00) and La/Th (0.15 to 18.92), and their origin is explained by derivation from a mixture of sedimentary and metasedimentary rocks. The wide range in trace and REE element characteristics as Co/Th (0.07 to 3.00), La/Sc (0.04 to 23.48), Sc/Th (0.06 to 7.57), V/Ni (2 to 3319), Cr/V (0.03 to 1.06) and Ni/Co (1.00 to 79.85) of these coaly metapelites argues for inefficient mixing of the various source lithologies during sedimentation.

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Stratum Corneum Lipids as Bioactive Materials for Atopic Dermatitis (생체활성 각질층 지질 - 아토피 피부염 관리를 중심으로 -)

  • Park Byeong Deog;Youm Jong Kyung;Ahn Sung Ku;Lee Seung Hun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.345-352
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    • 2004
  • There are two paradigms to explain the atopic dermatitis. The first is outside-inside paradigm and the second is inside-outside paradigm. According to the outside-inside paradigm the best way to treat the atopic dermatitis is recovery of skin barrier function. The barrier function is maintained by the specific structure of stratum corneum, which is constructed from corneocytes and intercellular lipids. In terms of lipid structures of SC in atopic dermatitis and lamellar ichthyosis, they contain more fluid hexagonal gel structures in SC and show deficiencies in free fatty acids, especially long chains and certain ceramides. With this reason, moisturizer which has the lamellar structure and restoring function of intrinsic intercellualr long periodicity phase can maintain and restore the lamellar structure of intercellular lipids in SC. The moisturizers containing ceramide or pseudoceramide also seem to be reasonable therapy for atopic dermatitis and several skin diseases, which interrelated with impaired skin harrier. By the way, according to the inside-outside paradigm, immune response including helper T cells, IgE, eosinophils is related. It is effective treatment of atopic dermititis to restore imbalance between Th1 and Th2 cells. Even though several kinds of immune-suppressor were introduced, these can affect the intrinsic immune function. SPC and S1P, metabolites of ceramide, would be interesting because they have the function of wound healing and immune modulating properties.

Preparation and Properties of Hollow Fiber Membrane for CO2/H2 Separation (이산화탄소/수소 분리용 중공사형 기체분리막의 제조 및 특성)

  • Hyung Chul Koh;Mi-jin Jeon;Sang-Chul Jung;Yong-Woo Jeon
    • Membrane Journal
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    • v.33 no.4
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    • pp.222-232
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    • 2023
  • In this study, a hollow fiber support membrane was prepared by a non-solvent induced phase separation (NIPS) method using a polysulfone (PSf). The prepared hollow fiber support membrane was coated with PDMS and Pebax to prepare a hollow fiber composite membrane. The prepared composite membrane was measured for permeance and selectivity for pure CO2, H2, O2 and N2. Gas separation performance of the module having the highest selectivity (CO2/H2) among the prepared composite membrane modules was measured according to the change in stage cut using simulated gas. The composition of the simulated gas used at this time was 70% CO2 and 30% H2. In the 1 stage experiment, it was possible to obtain values of about 60% of H2 concentration and 12% of H2 recovery. In order to overcome the low H2 concentration and recovery, 2 stage serial test was performed, and through this, it was possible to achieve 70% H2 concentration and 70% recovery. Through this, it was possible to derive a separation process configuration for CO2/H2 separation.