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Hydrochloric acid leaching behavior of metals from non-magnetic fraction of Pb dross
Sanghyeon Choi,Kyoungkeun Yoo,Richard Diaz Alorro 한국자원공학회 2019 Geosystem engineering Vol.22 No.6
The leaching behaviors of tin (Sn), antimony (Sb), iron (Fe), and lead (Pb) from non-magnetic fraction of Pb dross, which was obtained from magnetic separation process to remove As components, were investigated using HCl solution. The leaching efficiencies of Sn, Fe, and Pb increased with increasing agitation speed, temperature, and HCl concentration and with decreasing pulp density, but Sb was dissolved only in the 3 and 5 M HCl solutions. The leaching efficiencies of metals increased to 100% in the 5 M HCl solution at 400 rpm and 70°C with 1% pulp density within 120 min. In the case of leaching test with 1 M HCl, Sb components could be recovered as leach residue. After leaching test, Pb could be recovered as PbCl2 from the solution by lowering temperature. Tin ions were extracted selectively by solvent extraction with tri-butyl phosphate, remaining Fe and Pb ions in the solution. The process consisting of HCl leaching, precipitation, and solvent extraction recovers successfully Sb, Pb, and Sn from non-magnetic fraction of Pb dross.
최준섭(Junsub Choi),문태석(Taeseok Moon),최종인(Jongin Choi),박상현(Sanghyeon Park),김한솔(Hansol Kim),허환일(Hwanil Huh) 한국항공우주학회 2018 韓國航空宇宙學會誌 Vol.46 No.8
고도보정 노즐은 모든 고도에서 최적의 성능을 발휘할 수 있도록 고안된 노즐이다. 발사체의 비추력을 향상시키기 위한 방법으로는 연소실만의 특성인 특성배기속도를 향상시키는 방법과 노즐만의 특성인 추력계수를 향상시키는 방법이 있다. 고도보정 노즐은 동일한 연소기에서 노즐의 성능 개선을 통해 발사체의 성능향상을 가능하게 한다. 고도보정 노즐에 대한 연구는 독일 DLR에서 활발하게 진행되고 있으며, 미국, 러시아, 영국, 호주, 일본 등 항공우주선진국에서도 진행되고 있다. 본 논문에서는 고도보정 노즐에 대한 기술 현황 및 특허 동향에 대해 조사하였다. 이를 바탕으로 고도보정 노즐의 기술흐름을 파악하고 발사체 성능향상 연구에 기초자료로 활용하고자 한다. The altitude compensation nozzle is a nozzle designed for optimum performance at all altitudes. A method of improving the specific impulse of the space launch vehicle is a method of improving the characteristic exhaust velocity which is a characteristic of the combustion chamber and a method of improving the thrust coefficient which is a characteristic of the nozzle. The altitude compensation nozzle enables improvement of the performance of the space launch vehicle by improving the nozzle performance for the same combustor. Research on altitude compensation nozzles has been actively carried out in the DLR in Germany and is being carried out in advanced countries such as the US, Russia, UK, Australia and Japan. In this paper, the technology trends and patent trends of altitude compensation nozzles are investigated and summarized. Based on this, the technical trends of altitude compensation nozzles is grasped and utilized as basic data for the study on the performance improvement of a launch vehicle.
Algorithm for environmental risk assessment of cosmetics to reduce their environmental impact
Choi Min-Seok,Kim Seoyoung,Lee Si Eun,Yeon Sanghyeon,Park Sanghee,Yang Jun Yong,An Susun 한국독성학회 2023 Toxicological Research Vol.39 No.1
Cosmetics, especially rinse-off personal care products (PCPs), such as shampoo, facial cleanser, and body wash, are composed of various chemicals and are one of the sources of chemicals released into aquatic ecosystems. Therefore, the cosmetic industry strives to reduce the impact of their products on the aquatic environment. In this study, we proposed an algorithm based on persistence, bioaccumulation potential, and toxicity (PBT) for the environmental risk assessment of cosmetics. PBT features are generally used in the evaluation of the environmental impact of chemicals. Based on the PBT assessment, it is possible to predict the short- and long-term effects of chemicals on the environment. Our algorithm derives substance and product scores from PBT features, allowing for the risk assessment of each ingredient in the product. Furthermore, we proposed a criterion for the environmental impact grade through which each component can be classified. We intend to use this grade and factors determined through the algorithm to manufacture products with low environmental impact.
EDR 기록정보와 PC-Crash를 활용한 차량 전복 사고 분석
임상현(Sanghyeon Lim),오원택(Wontaek Oh),최지훈(Jihun Choi),박종찬(Jongchan Park) 한국자동차공학회 2020 한국 자동차공학회논문집 Vol.28 No.4
In the case of vehicle fall and rollover accidents, crashes often occur at high speeds. Directly after the crash, the vehicle’s movement varies rapidly, and the occupants’ movements also change highly according to the vehicle’s motion. In addition, if the occupants did not wear their seatbelts, they would leave the vehicle with an increased probability of death. Impact spot, impact speed, and impact position are commonly considered important factors in general vehicle accidents, but if the vehicle falls or rolls over, which does not commonly occur, there is a need to know the falling time point and the route by which the vehicle reached the final position. In this study, vehicle fall and rollover accident reconstruction was performed using PC-CrashTM, where event data recorder(EDR) data exist, and by comparing the EDR rollover angle with the PC-CrashTM roll angle, reliability evaluation of the accident reconstruction simulation was performed.
PC-CRASH의 충돌 최적화를 이용한 차량의 충돌 속도 추정
임상현(Sanghyeon Lim),오원택(Wontaek Oh),최지훈(Jihun Choi),박종찬(Jongchan Park) 한국자동차공학회 2019 한국 자동차공학회논문집 Vol.27 No.12
According to the Automobile Management Act, the EDR data of vehicles launched after 2016 should be made accessible to the public. Based on the Ministry of Land statistics, there were 54.03 million cars registered after 2016, thereby accounting for approximately 42 % of the number of cars registered between 2011 and 2018. The speed before impact is the most important factor in the case of a vehicle-to-vehicle collision. If it is possible to retrieve the EDR data, its impact speed can be extracted easily. Otherwise, we need to calculate the impact speed by using some evidence. This paper reconstructed the vehicle accident by utilizing the PC-CRASH collision optimal function with the damaged spot of the vehicle and the final stop position of the cars. We calculated the impact speed and compared this estimated impact speed with the real impact speed by using the reconstructed accident scenario. The reliability of the simulation was evaluated based on this.
문상현 ( Sanghyeon Moon ),김지영 ( Jiyoung Kim ),최현국 ( Hyun-kuk Choi ),김문갑 ( Moon-gab Kim ),이영세 ( Young-sei Lee ),이기영 ( Kiyoung Lee ) 한국공업화학회 2021 공업화학 Vol.32 No.3
금속 유기 골격체는 최근 20년간 센서, 촉매, 에너지 저장과 같은 많은 응용분야에서 관심을 받아온 물질이다. 이 물질을 합성하기 위해 수열 합성, 유기용매열과 같은 합성법이 제시되어 왔으나, 그 공정이 복잡하면서 고비용·장시간이 소요된다는 문제점이 제기되어 왔다. 이를 해결하기 위한 전기화학적 합성법이 새롭게 제시되었는데, 간단한 준비 절차와 특정한 온도·압력 조건 없이 합성할 수 있어 기존 합성법의 단점을 보완한다는 특징이 있다. 이에 본 총설논문에서는 전기화학적으로 합성 가능한 금속 유기 골격체의 종류와 전기화학적 합성 메커니즘을 다루고 있다. 전기화학적 합성법을 통해 형성된 금속 유기 골격체를 적용한 응용분야 연구동향을 정리하였다. During the last two decades, metal-organic frameworks (MOFs) have been drawn attention due to their high specific surface area, porosity, and catalytic activities that allow to use in many applications such as sensor, catalysis, energy storage, etc. To synthesize MOFs hydrothermal or solvothermal method were generally used. However, these methods require high-cost equipment and long time-spend for the synthesis with multi-step process. In contrast, electrochemical synthesis has been considered as a simple and easy process under the ambient conditions. In this review, we described the mechanism of electrochemical MOFs synthesis by the number of configured electrodes system, with the recent reports of various applications.
가스터빈 연소기에서 메탄과 수소 혼합 비율 및 운전조건에 따른 연소특성 연구
이상현(Sanghyeon Lee),이재빈(Jaebin Lee),안병민(Byeongmin Ahn),강도원(Dowon Kang),김민국(Minkuk Kim),최민성(Minsung Choi) 한국연소학회 2023 KOSCOSYMPOSIUM논문집 Vol.2023 No.11
This study investigated the combustion characteristics in a gas turbine combustor with varying methane and hydrogen mixing ratios and operating conditions. We conducted study through CFD analysis and presented the results of temperature, velocity, fuel mixedness, and NOx emissions for hydrogen mixture. All simulations were conducted under high-pressure conditions at 25.9 bar, and hydrogen mixture were varied from 0% to 60%. The simulation results showed that as the mixture ratio increased, NOx exhibited the most significant difference, while the other parameters did not show a significant impact.