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아크롤레인 선택 산화반응에서 Mo-V-O와 SnO<sub>2</sub>의 상간협동 - II. 담지촉매 -
박대원,나석은,김경훈,이원호,정종식,Park, Dae-Won,Na, Suk-Eun,Kim, Kyung-Hoon,Lee, Won-Ho,Chung, Jong Shik 한국공업화학회 1994 공업화학 Vol.5 No.2
$Mo-V-O/SnO_2$(VM/Sn) and $SnO_2/Mo-V-O$(Sn/VM) catalysts have been prepared and characterized by XRD, BET, SEM and TPD of ammonia. The catalytic reaction of acrolein oxidation with these catalysts, in a continuous-flow fixed-bed reactor, showed that they had higher conversion of acrolein and higher yield of acrylic acid than those of Mo-V-O itself. The origin of the observed synergy studied by TPD, TPR and TPO is explained by the cooperation of $SnO_2$ and Mo-V-O at their interfaces where electrons flow from Mo-V-O phase to $SnO_2$ and $SnO_2$ produces spill-over oxygens, which, by being transported onto the surface of Mo-V-O, reoxidize the partially reduced active sites.
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박대원,이정윤,길경석,Park, Dae-Won,Lee, Jung-Yoon,Kil, Gyung-Suk 한국전기전자재료학회 2012 전기전자재료학회논문지 Vol.25 No.9
This paper dealt with the measurement and analysis of electromagnetic waves radiated from a partial discharge (PD) source in insulation oil to apply condition monitoring of oil-immersed transformers. Two types of narrow-band monopole antennas with the resonant frequency of a 500 MHz and a 1 GHz were designed and fabricated. Also, a needle-plane electrode system was manufactured to simulate PDs and the curvature radius of the needle is 10 ${\mu}m$ and the diameter of the plane is 60 mm. Electromagnetic wave was measured by the PD measurement system with the monopole antennas. Detection sensitivity of the fabricated antenna was compared for the same PD magnitude; 620 $mV_{peak}$ for the 500 MHz antenna and 960 $mV_{peak}$ for the 1 GHz antenna to the PD magnitude of 74 pC. Consequently, the 1 GHz monopole antenna is more effective to detect PDs in oil-immersed transformers.
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아크롤레인 선택산화반응 에서 Mo - V - O 와 SnO2 의 상간협동
박대원,나석은,김경훈,이원호 ( Dae Won Park,Suk Eun Na,Kyung Hoon Kim,Won Ho Lee ) 한국화학공학회 1994 Korean Chemical Engineering Research Vol.32 No.2
The present study was aimed to elucidate the mechanism of synergy effect in mechanically mixed catalysts of Mo-V-O and SnO₂ for the selective oxidation of acrolein. Physical and structural properties of catalysts were characterized by TG/DTA, BET, XRD and SEM. TPD of ammonia was carried out for the measurement of catalyst acidity. Reduction and oxidation behaviors of catalysts were studied using TPD, TPR and TPO. Reaction test showed that the mixture catalysts had higher conversion of acrolein than either of the each metal oxide. The origin of the synergy is attributed to the cooperation of the two metal oxide, in which electrons flow from Mo-V-O phase to SnO₂ at their interface and it creates oxygen vacancies in SnO₂. Dissociated oxygen ions formed by the oxygen vacancies of SnO₂ move to Mo-V-O, active phase for the formation of acrylic acid, and promotes its reoxidation.
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박대원,정진영,정윤철,윤운영 ( Dae Won Park,Jin Young Jung,Yun Chul Chung,Woon Young Yun ) 한국물환경학회 1995 한국물환경학회지 Vol.11 No.2
Experiments were conducted to investigate the effect of MLSS concentration on the performance of a sequencing batch reactor (SBR) treating industrial wastewater containing high concentration of organics and nitrogen. Three laboratory-scale reactors were designed and operated at different MLSS concentration. Total organic carbon and nitrogen concentration in the reactors were monitored over reaction time. The higher MLSS concentration in the reactor resulted in the greater COD removal rate with up to 1.24㎏ COD/㎥.day. The higher MLSS concentration resulted in the lower TOC concentration in the effluent. It was observed from monitoring ammonia in the reactor that the higher MLSS concentration in the reactor resulted in the higher rate of ammonia oxidation and the earlier production of NO₃-N. MLSS concentration was observed to be an important factor determining removal rate of organic and ammonia
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박대원,송재용,한주섭,길경석,Park Dae-won,Song Jae-yong,Han Joo-sup,Kil Gyung-suk 한국정보통신학회 2005 한국정보통신학회논문지 Vol.9 No.6
본 논문은 외부의 서지로부터 컴퓨터 네트워크회로의 보호를 위한 서지방호장치에 대하여 기술하였다. 서지방호장치는 동작속도가 빠른 아발란시 다이오드와 에너지 내량이 큰 가스튜브의 하이브리드형으로 구성하였으며, 고주파 대역에서의 삽입손실을 줄이기 위하여 고속회복 다이오드를 사용하였다. 제안한 서지전압 차단장치의 성능 평가를 위하여 국제규격 IEC 61000-4-5 및 IEC 61643-21에 따라 서지차단특성과 신호전송 특성평가를 수행하였다. 실험결과로부터 본 서지차단장치는 국제규격에 제시된 서지차단특성을 만족하였으며, -3dB의 고역차단 주파수가 204 MHz로 100 Mbps급 근거리 통신네트워크에 적합한 특성을 나타내었다. This paper dealt with the development of surge protection devices (SPDs) that can protect high speed computer network devices from overvoltages caused by switching operations or lightning surges. The designed SPD is a form of hybrid circuit which is composed of a gas tube having large current diverting capability, high response bi-directional avalanche diodes, and fast recovery diodes to reduce insertion loss on high frequency domain. Surge protection and signal transmission characteristics of the fabricated SPD was tested according to the international standards, IEC 61000-4-5 and IEC 61643-21. From the test results, the SPD is satisfied with the international standards and the high cut-off frequency was 204 MHz. Also, the SPD showed a good performance without an insertion loss on a field test of 100 Mbps class Local Area Network.
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