Effect of Attrition Scrubbing on the Recovery of Platinum Group Metals from Spent Automobile Catalytic Converters

김완태,김형석,조성백,이재천,김상배,Kim, Wan-Tae,Kim, Hyung-Seok,Cho, Sung-Baek,Lee, Jae-Chun,Kim, Sang-Bae The Korean Institute of Resources Recycling 2008 資源 리싸이클링 Vol.17 No.5

The effect of attrition scrubbing on the recovery of platinum group metals (PGMs) from automobile catalytic converters has been investigated. Catalytic converters were first crushed into particles less than 2 mm and attrition scrubbed in the range of 60 min, and then they were sieved with several screens. The catalyst layer, $\gamma$-alumina, was dislodged from the surface of the supporting matrix into fine particles less than $45{\mu}m$ by attrition scrubbing. The fraction of fine particles less than $45{\mu}m$ increased as the residence time for attrition scrubbing increased. The composition of the fine fraction obtained at a residence time of 40 min was $CeO_2$ 19.3%, $ZrO_2$ 1.9% and PGMs 419 ppm. In the fine fraction, the recovery of y-alumina increased proportionally to the residence time. Simultaneously, the recovery rates of $CeO_2$, $ZrO_2$ and PGMs increased to 82.9%, 78.7% and 78.9%, respectively. The production of the fine fraction less than $45{\mu}m$ and the recovery of $\gamma$-alumina increased when the solid concentration and initial feed size increased. Therefore, the attrition scrubbing as the comminution and separation process was concerned to be effective for the recovery of catalyst layer from ceramic supporting matrix by physical impact and shearing action between particles in the scrubbing vessel. 자동차 폐촉매로부터 백금족 금속(PGMs)의 회수를 위한 어트리션 스크러빙의 효과를 조사하였다. 자동차 폐촉매를 2mm이하로 분쇄한 후 60분 범위내에서 어트리션 스크러빙하였으며 이를 체가름하였다. 스크러빙을 통해 촉매층은 촉매 지지체 표면으로부터 탈리되어 $45{\mu}m$이하의 미립자로 분리되었다. $45{\mu}m$ 이하 미립자의 양은 스크러빙 시간이 증가함에 따라 증가하였으며, 스크러빙 시간 40분에서 미립자의 유가물 함량은 $CeO_2$ 19.3%, $ZrO_2$ 1.9%, PGMs 419ppm을 나타내었다. 미립자에서 감마 알루미나의 회수율은 스크러빙 시간이 증가함에 따라 증가하였으며, 동시에 $CeO_2$, $ZrO_2$ 및 PGMs의 회수율도 $CeO_2$ 82.9%, $ZrO_2$ 78.7%, PGMs 78.9%로 증가하였다. 시료의 고액비 및 초기 투입 입자 크기가 증가할 때 미립자의 양 및 감마알루미나의 회수율은 증가하였다. 어트리션 스크러빙은 분쇄 및 분리 기술로서 스크러빙 용기내에서 입자들 사이의 충격 및 전단 운동에 의해 코디어라이트 촉매 지지체로부터 감마알루미나의 분리에 효과적임을 알 수 있었다.

Clipping 구조를 개선한 OFDM 전송시스템의 PAPR 감소에 관한 연구

김완태,조성준,Kim, Wan-Tae,Cho, Sung-Joon 한국정보통신학회 2007 한국정보통신학회논문지 Vol.11 No.8

Recently many communication systems ate adapting the OFDM(Orthogonal Frequency Division Multiplexing) for multimedia data services. However, OFDM has some problems that PAPR is increased when sub-carries are summed up with same phases. This problem causes severe signal distortions while the signal is passing through non-linear system such as power amplifier resulting in performance degradation of transmission system. In this paper, we use IF-Clipping method to solve PAPR problem and the signal distortion caused by clipping is limited by use of SAW (Surface Acoustic Wave) filter and power amplifier(TWTA). And we derive the optimal parameter(PAPR, Backoff) values to meet the spectrum mask of WiBro system. 현재의 통신 시스템은 멀티미디어 서비스를 제공하기 위하여 OFDM(Orthogonal Frequency Division Multiplexing) 방식이 주로 쓰이고 있다. 그러나 OFDM 방식은 다수의 부반송파를 사용하므로 부반송파들이 동일위상으로 더해질 때 놀아지는 PAPR(Peak-to-Average Power Ratio)이 문제가 되고 있다. PAPR의 문제는 신호가 전력증폭기와 같은 비선형 소자를 통과할 때 심각한 왜곡을 받게 되므로 전송시스템 성능이 저하된다. 본 논문에서는 PAPR 문제를 해결하기 위해 IF-Clipping 기법을 제안하고, 신호의 clipping에 의해 발생되는 신호의 왜곡을 SAW(Solace Acoustic Wave) 필터와 전력증폭기를 사용하여 제한하였다. 또한 clipping 기법 이용 후 SAW Filter와 전력증폭기를 사용하여 WiBro 시스템의 Spectrum Mask를 만족하는 이상적인 파라메터 값(PAPR, Backoff)을 찾았다.

안전한 ESS 사용을 위한 System 구조와 GUI 구현에 관한 연구

김완태,김현식,박병준,Kim, Wantae,Kim, Hyunsik,Park, Byungjoon 디지털산업정보학회 2019 디지털산업정보학회논문지 Vol.15 No.2

As interest in the efficiency use of energy has been recently rising, studies have been performed in utilizing various types of eco-friendly green energy and natural energy. Especially there has been rapidly increase in the fields using ESS (Energy Storage System), which is the technology for storing the energy from nature. The application fields of ESS is continuously growing and expanding to various types of technologies. However, in recent years there have been continuing problems with the safety of ESS. And related researches are going on. In this paper, we has proposed a system structure to utilize more secure ESS and has monitored the system status of ESS in real time by using smart phone app. This paper has also proposed a new method to configure secure ESS by implementing GUI (Graphical User Interface) to control the system. And then explain experimental results to investigate the efficiency of the proposed ESS.

만경강유역에 (萬頃江流域) 있어서 정수중의 (井水中) 불소항량에 관한 연구

김완태,안영근,신화우,장현숙 ( wan Tae Kim,Young Gun Ahn,Wha Woo Shin,Hyun Sook Chang ) 한국하천호수학회 1978 생태와 환경 Vol.11 No.3·4

This study is the survey about Fluorine contents in the well water of area of Mankyung River side and water of Mankyung River. The result of this survey is as followings: The water of well in this area contained 0.5∼1.3ppm and it`s average value was about 0.8ppm. The water from Mankyung River contained 0.8∼0.9ppm and it`s average value is 0.87ppm. By the regionally sectional survey the well water of the area of Mankyung River side, the well water of Chunju, Iri, Samye, and Kunsan contained 0.5∼0.8ppm, but the well water of Baikku area contained 0.6∼1.3ppm. Especially in Baikku area 63% of well contained 0.6∼1.0ppm and 38% of well contained 1.1∼1.3ppm. From the above results one can conclude that the 38% of well water of the Baikku area is troubled one.

명사초대석-나의 건강비결

김완태,Kim, Wan-Tae 한국건강관리협회 1983 건강소식 Vol.7 No.6

윗몸일으키기가 불가한 요통 환자에 대한 흉쇄유돌근과 요근의 반응성 근육조절 치료 방법의 적용에 관한 실험

김완태,Kim, Wan-Tae 대한물리치료과학회 2006 대한물리치료과학회지 Vol.13 No.1

Purpose: The purpose of this experimental study have been testifying about reactive muscle control regarding sternocleidomastoid and psoas. Low back pain patient do not sit-up exercise without abnormality of trunk flexor. The reason of problem is unbalance sternocleidomastoid and psoas. According to George J, Goodheart who have been developing Applied Kinesiology (A. K.) since reactive muscle recognized gait testing in 1964. Materials and Methods: From September, 2004 to February, 2005, I have controled sternocleidomastoid and psoas. It is applied to the patients who are unable sit up exercise at Yang-Dong local clinic, Yang-Pyung county, Kyung-Gi Do province in Korea. 24 Patients divided 2 groups. A group is applied general physical therapy. Also B group is added reactive muscle control from M.E.M.P.T.(Korean society of muscle and energy monitoring physical therapy) Results : The results of this study follow. 1. Possible sit up group 8 persons of the second group. 2. Not possible sit up group the others. Conclusion: The study present that reactive muscle control sternocliedomastoid and psoas is useful in patient with low back pain is difficult to sit up.

최적 계획생성을 위한 동작비용 기반의 휴리스틱

김완태,김현식,Kim, Wantae,Kim, Hyunsik 디지털산업정보학회 2017 디지털산업정보학회논문지 Vol.13 No.2

Highly informative admissible heuristics can help to conduct more efficient search for optimal solutions. However, in general, more informative ones of heuristics from planning problems requires lots of computational effort. To address this problem, we propose an Delete Relaxation based Action Costs-based Planning Graph(ACPG) and Action Costs-based Heuristics for solving optimal planning problems more efficiently. The ACPG is an extended one to be applied to can find action costs between subgoal & goal conditions from the Relaxed Planning Graph(RPG) which is a common means to get heuristics for solving the planning problems, Action Costs-based Heuristics utilizing ACPG can find action costs difference between subgoal & goal conditions in an effective way, and then consider them to estimate the goal distance. In this paper, we present the heuristics algorithm to compute Action Costs-based Heuristics, and then explain experimental analysis to investigate the efficiency and the accuracy of the Action Costs-based Heuristics.

OFDM 시스템에서 PAPR의 감소와 대역 내 왜곡 보정에 관한 연구

김완태,유선용,조성준,Kim, Wan-Tae,Yoo, Sun-Yong,Cho, Sung-Jun 한국정보통신학회 2008 한국정보통신학회논문지 Vol.12 No.5

OFDM (Orthogonal Frequency Division Multiplexing) system is robust to frequency selective fading and narrowband interference in high-speed data communications. However, an OFDM signal consists of a number of independently modulated subcarriers, which can give a large PAPR (Peak-to-Average Power Ratio) when added up coherently. In this paper, we apply clipping and filtering to solve the PAPR problem and compensate the inband compensation using calculated EVM (Error Vector Magnitude). The proposed method can reduce the PAPR and inband distortion. From the results, we analyze the PAPR reducing efficiency and EVM, BER performance of proposed algorithm in the wireless communication system. OFDM (Orthogonal Frequency Division Multiplexing) 방식은 주파수 선택적 페이딩 (frequency selective fading)과 협대역 간섭 (narrwband interference)에 강한 전송 방식으로 대용량 데이터 통신에 적합하다. 하지만, OFDM 신호는 독립적으로 변조된 많은 부반송들로 구성되므로 이들이 동위상으로 더해질 때 신호의 진폭이 증가하여 PAPR(Peak-to-Average Power Ratio) 문제가 발생한다. 본 논문에서는 OFDM 시스템의 PAPR 문제를 해결하기 위해 반복구조의 clipping과 filtering 기법을 적용하고, 이로 인해 발생되는 대역 내 왜곡을 EVM (Error Vector Magnitude)을 이용하여 보정하는 기법을 제안하였다. 이 기법은 PAPR 감소는 물론 clipping에 의한 대역 내 왜곡을 감소시킬 수 있다. 제안하는 알고리즘을 무선 통신 시스템에 적용하였을 때 PAPR 감소 효율과 EVM, BER (Bit Error Rate) 성능을 시뮬레이션을 통해 분석했다.

공동육아시설의 적정 입지 선정에 관한 연구 : 서울시 강서구를 사례로

김완태(Wan-tae Kim),김나연(Na-yeon Kim),김민서(Min-seo Kim),이영미(Young-mee Lee),정민우(Min-woo Jeong),지수빈(Su-bin Ji) 대한지리학회 2023 대한지리학회 학술대회논문집 Vol.2023 No.06

교과서 분석을 통한 북한 기술과 교육의 실태

김완태(Wan Tae Kim),최준섭(Jun Seop Choi) 대한공업교육학회 1997 대한공업교육학회지 Vol.22 No.1

This study is a comparison of technology education between South and North Korea. The purpose of this study is to understand the existing and actual state of education in North Korea by analyzing the technological textbooks in their high schools and to find the differences in terminology and term used in both countries. The main findings from this study are as follows: (1) The current technology curriculum in North Korea is composed of mechanical manufacturing activity, electronic machinery, and drawing as compulsory subjects. And according to individual school characteristics, there are some differences in the case of practice subjects. (2) Most terminologies related to automobile technology in North Korea are quite different from South Korea. (3) Some differences are found in the standard of classification of automobiles, traffic rules between South and North Korea. (4) Through the Doctrine the textbook is used for bring up a man who is fully obeying to the guidance of the Great Leader Kim, Ii-Sung and used for a] tool to substain the socialist political structure.