• Title/Summary/Keyword: Major Materials

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A Study on Storage of Major Herbal Medicine Materials, Zingiberis Rhizoma

  • Choi, Seong-Kyu;Yun, Kyeong-Won;Shin, Kil-Man
    • Plant Resources
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    • v.5 no.3
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    • pp.224-227
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    • 2002
  • To develop optimal storage method of root of Zingiberis Rhizoma, which has been grown as major cultural herbal medicine materials, root of Zingiberis Rhizoma, was stored for 10 months with different packing materials and sealing methods. The loss in dry weight as influenced by packing materials and sealing methods was the lowest at vacuum packing and followed by complete sealing methods with transparent polyethylene film. The ratio of root rot during the storage period was not significantly different between packing materials but was significantly different between sealing conditions. Conclusionally, vacuum packing and complete sealing with polyethylene film appears to be optimal for storage of Zingiberis Rhizoma.

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A Basic Study on the Storage of Major Chinese Herbal Medicine Materials , Moutan Radicis Cortex (주요 한약재인 목단피의 저장에 관한 기초 연구)

  • KyongJuChoi
    • Korean Journal of Plant Resources
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    • v.7 no.2
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    • pp.183-186
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    • 1994
  • This study was conducted to investigate desirable storage method to major chinese herbal medicine materials, Moutan Radicis Cortex in different packing materials and sealing degree. The loss in weight of Moutan Radicis Cortex as influenced by packing materials was the lowest at complete sealing treatment with transparent or black polyethylene film. The rot ratio of Moutan Radicis Cortex during the storage period was not difference between packing materials, transparent and black polyethylene film, but rot ratio of complete sealing condition was lower than punch ($\phi$J5mm) on polyethylene film.

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Multifunctional Fire Sensor Fabricated on a Flexible Substrate (플렉서블 기판상에 제작한 다기능 화재센서에 관한 연구)

  • Seo, JoonYoung;Ko, Dongwan;Choi, Junseck;Noh, JaeHa;Jung, Jung-Yeul;Lee, MoonJin;Lee, Sangtae;Chang, Jiho
    • Journal of Sensor Science and Technology
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    • v.29 no.1
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    • pp.40-44
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    • 2020
  • An integrated multifunctional sensor, capable of raising an early electric-fire warning, was fabricated. An arc-light, temperature, and humidity sensor was fabricated on a flexible substrate using a printed thin film of indium tin oxide. A polyethylene terephthalate (PET) substrate was used as the flexible substrate. The sensor was fabricated on a PET substrate, and its operating characteristics were tested. The operating performances of the sensor when serving as an arc-light, a temperature, and a humidity sensor were estimated to be 0.6247 Ω/W, 80.6 Ω/K, and -4.08 Ω/RH, respectively. The feasibility of the proposed fire sensor was demonstrated; it costs low and offers multiple functionalities.

A Study on the Fabrication of Multi-Walled Nanotubes (MWCNT) Based Thin Film and Chemical Sensor Operation Characteristics (Multi-Walled Carbon Nanotubes (MWCNT) 인쇄박막의 제작과 화학센서 동작 특성에 관한 연구)

  • Noh, Jae Ha;Choi, Junseck;Ko, Dongwan;Seo, Joonyoung;Lee, Sangtae;Jung, Jung-Yeul;Chang, Jiho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.33 no.3
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    • pp.181-185
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    • 2020
  • Hazardous and noxious substance (HNS) detection sensors were fabricated using multi-walled carbon nanotubes (MWCNTs) and various binder materials for ion batteries. To obtain uniformly printed films, the printing precision according to the substrate cleaning method was monitored, and the printing paste mixing ratio was investigated. Binders were prepared using styrene butadiene rubber + carboxymethyl cellulose (SBR+CMC), polyvinylidene fluoride + n-methyl-2-pyrrolidene (PVDF+NMP), and mixed with MWCNTs. The surface morphology of the printed films was examined using an optical microscope and a scanning electron microscope, and their electrical properties are investigated using an I-V sourcemeter. Finally, sensing properties of MWCNT printed films were measured according to changes in the concentration of the chemical under the various applied voltages. In conclusion, the MWCNT printed films made of (SBR+CMC) were found to be feasible for application to the detection of hazardous and noxious chemicals spilled in seawater.

Simulation of outgassing effects of vacuum materials on vacuum characteristics

  • Kim, Hyung-Taek;Kim, Young-Suk
    • Journal of the Semiconductor & Display Technology
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    • v.8 no.1
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    • pp.7-12
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    • 2009
  • The outgassing effects of selected vacuum materials on the vacuum characteristics were simulated by the $VacSim^{Multi}$ simulation tool. This investigation examined the feasibility of reliably simulating the outgassing characteristics of common vacuum chamber materials (aluminum, copper, stainless steel, nickel plated steel, Viton A). The optimum design factors for these vacuum systems were suggested based on the simulation results. The baking-out effects of the modeled systems and materials on the performance of the vacuum system were also analyzed. The simulation predicted that the overall outgassing effect was more significant in the TMP system than in the DP system and that the utilization of a booster pump has a greater effect on the evacuation time than on the ultimate pressure.

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Acoustic Property and Hardness of Coatings for Musical Instruments with Various Coating Thicknesses

  • Hwang, Hyeon-Deuk;Lee, Byoung-Hoo;Choi, Jae-Hoon;Kim, Hyun-Joong;Chung, Woo-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.34 no.2
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    • pp.58-67
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    • 2006
  • The relationship between acoustic property and coating hardness of musical instruments was investigated using a sound level meter and a pendulum hardness tester. Urethane topcoat, oil stain, natural oil varnish, and UV-curable epoxy acrylate coatings were applied on four different substrates: Paulownia coreana, Pinus koraiensis, Castanea crenata var. dulcis and Pinus densiflora. The influence of the coating type on the acoustic properties was stronger than that of the substrate. In the case of an oil stain formed with tacky coating layer, the sound pressure level (SPL) and surface hardness decreased with increasing of coating thickness. In the other coatings, SPL decreased and hardness increased as the coating layer thickened. However, SPL began to increase again at coating thickness above $100{\mu}m$.

Investigation on the Excitonic Luminescence Properties of ZnO Bulk Crystal (ZnO 기판의 불순물 속박 엑시톤 발광을 이용한 물성 분석)

  • Choi, Jun Seck;Ko, Dong Wan;Jeong, Min Ji;Lee, Sang Tae;Chang, Ji Ho
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.32 no.3
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    • pp.196-200
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    • 2019
  • In this study, photoluminescence (PL) analysis was performed to evaluate the optical properties of commercial ZnO substrates. Particular attention was paid to the bound exciton (BX) luminescence, which is usually the strongest emission intensity of commercial substrates. At 15 K, PL analysis revealed that the BX peak due to donor-type impurities (donor-bound-exciton; DX) dominated, while two-electron satellite (TES) emission, donor-accepter pair (DAP) emission, and LO-phonon replica emission were also observed. The impurity concentration of the ZnO substrate was determined to be $10^{15}$ to $10^{16}/cm^3$ by examination of the temperature variation of DAP, while the half width and intensity change of the luminescence revealed that the temperature change of BX can be interpreted almost the same as the analysis of free-exciton emission.

Temperature-Dependent Characteristics of Carbon Nanotubes-Film-Based Electrochemical Sensor (CNT 필름 전기화학 센서의 온도 의존 특성에 관한 연구)

  • Noh, Jaeha;Ahn, Hyung Soo;An, Sangsu;Lee, Changhan;Lee, Sangtae;Lee, Moonjin;Seo, Dongmin;Chang, Jiho
    • Journal of Sensor Science and Technology
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    • v.31 no.3
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    • pp.163-167
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    • 2022
  • In this study, we investigated a carbon nanotube (CNT) film sensor to detect hazardous and noxious substances distributed in seawater. The response change of the sensor was studied according to environmental temperature, and its temperature coefficient of resistance (TCR, α) was measured. The temperature of the CNT film (~50 ㎛) was in the range of 20-50 ℃, and αCNT was calculated to be -0.0011 %/ ℃. We experimentally confirmed that the CNT film had a smaller TCR value than that of the conventional sensor. Therefore, we investigated the response change of the CNT sensor according to temperature. The CNT sensor showed a relatively small error of approximately 2.3 % up to 30 ℃, which is within the temperature range of the seawater of the Korean Peninsula. However, when the temperature exceeded 40 ℃, the error in the CNT sensor increased by more than 5.2 %. We fabricated a metal oxide (ITO, indium-tin-oxide) film and compared its performance with that of the CNT sensor. The ITO sensor showed an error of >12.5 % at 30 ℃, indicating that in terms of the stability of the sensor to temperature, the CNT film sensor has superior performance.

Ni Catalyst Properties for Ammonia Reforming: Comparison of Ni Content and Space Velocity (암모니아 개질에 대한 Ni 촉매 특성: Ni 함량과 공간속도 비교)

  • WOO, JINHYEOK;KIM, TAEYOUNG;KIM, JU EON;CHO, BYUNGOK;JUNG, SUKYONG;PARK, SAEMI;LEE, SOOCHOOL;KIM, JAECHANG
    • Transactions of the Korean hydrogen and new energy society
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    • v.32 no.6
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    • pp.464-469
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    • 2021
  • A reforming catalyst for hydrogen production from ammonia is being studied. Non-novel metal based Ni catalysts for use in ammonia reforming processes are being developed. In this study, the ammonia reforming characteristics according to Ni content of the alumina pellet supported catalyst in the mid-temperature region were investigated under different space velocity. 20 Ni and 3,000 h-1 showed the best catalytic activity with ammonia conversion of 63% among all conditions.