Demagnetization followed by remagnetization of waste NdFeB magnet for reuse

이광석,유경근,윤호성,김철주,정경우 한국자원공학회 2013 Geosystem engineering Vol.16 No.4

New recycling process was proposed to reuse the waste NdFeB magnet scrap powder from the manufacturing process of NdFeB magnet and disc from motor of waste washing machine. The feasibility study was carried out to examine demagnetizing followed by remagnetizing the waste NdFeB magnets. The X-ray diffractometer patterns showed that the peaks of Fe were observed and those of NdFeB disappeared with increasing temperature to more than 5008C under the Ar atmosphere. The weight increased more under the air atmosphere than under the Ar atmosphere in TG-DTA test. After the waste NdFeB magnets were demagnetized at 300–5008C under the air and Ar atmospheres, they were remagnetized, and the magnetic power was measured. All remagnetization ratios showed more than 100% except the waste NdFeB magnet demagnetized at 5008C under the air atmosphere. The remagnetization ratio decreased with increasing the demagnetization temperature, and the decrease is faster under the air atmosphere than under the Ar atmosphere, which would result from the metal crystal structure change.

시판(市販) 작약(芍藥)의 Paeoniflorin 및 무기성분(無機成分) 함량(含量)

정상환,서동환,박노권,이숙희,김기재,이광석,최부술,강광희 韓國藥用作物學會 1993 한국약용작물학회지 Vol.1 No.2

1989년(年) 10월(月)부터 1990년(年) 5월(月)까지 국내(國內) 시판(市販) 생약중(生藥中) 작약(芍藥)에 대(對)하여 생약(生藥)의 안정성(安全性)과 유효성(有效性) 및 품질관리상(品質管俚上)의 기초자료(基礎資料)를 얻고자 생약근중(生藥根中)에 존재(存在)하는 Paeoniflorin 및 회분(灰分)과 무기성분(無機成分) 함량(含量)을 조사분석(調査分析)한 결과(結果)를 요약(要約)하면 다음과 같다. 1. 9개(個) 수집지역(蒐集地域)의 작약근중(芍藥根中)의 Paeoniflorin 함량(含量)은 평균(平均) 2.87%였다. 2. 회분함량(灰分含量)은 평균(平均) 4.28%로 대한약전(大韓藥典) 규격(規格) 6.5% 이하(以下)였으며 산불용성(酸不溶性) 회분(灰分) 함량(含量)은 평균(平均) 0.55%로써 기준치(基準値) 0.5%보다 0.05% 정도(程度) 상회(上廻)하였다. 3. 9개(個) 수집지역(蒐集地域)의 작약근중(芍藥根中)의 평균(平均) 총질소(總窒素) 함량(含量)은 0.70%, 인산(燐酸)은 0.69%, 칼륨은 0.73%, 칼슘은 1.02%, 철함량(鐵含量)은 82.15ppm이었다. 4. 아연함량(亞鉛含量)은 평균(平均) 34.59ppm이어서 주요농산물중(主要農産物中)의 대두(大豆) 및 보리와 대등(對等)한 함량(含量)을 나타내었고 마그네슘 함량(含量)은 평균(平均) 0.25%이었다. 5. 시판용(市販用) 작양근중(芍藥根中)의 평균(平均) Cd 함량(含量)은 0.31ppm Cu 함량(含量)은 4.95ppm Pb 함량(含量)은 2.47ppm이었고 특(特)히 생약중(生藥中) 잔류량(殘留量) 문제(問題)로 심각(深刻)한 Pb 함량(含量)으로 보아 국내산(國內産) 시판용(市販用) 작약(芍藥)으로써는 큰 문제(問題)가 없을 것으로 판단(判斷)되었다. 6. 작약(芍藥)은 토양별(土壤別), 재식년수별(裁植年數別), 재식지역(栽培地域) 또는 재식방법(栽培方法)과 가공(加工) 조제(調劑) 방법(方法)에 따라서 생약(生藥)으로 사용(使用)되는 근중(根中)의 Paeoniflorin 및 회분(灰分) 함량(含量), 3요소(要素) 함량(含量), 중금속함량(重金屬含量) 등(等)에 많은 차이(差異)가 있을 것이며 향후(向後) 더 많은 연구(硏究) 검토(檢討)가 요망(要望)된다. This study was carried out to investigate the contents of ash and inorganicelements in the herbaceous paeony roots collected from the markets of 9 regions in Korea. The contents of paeoniflorin ranged from 2.14% to 3.7%, and the average was 2.87%. The mean contents of ash was 4.2% and acid insoluble ash content was 0.55%. Total nitrogen of herbaceous paeony roots was 0.7%, phosphorus 0.69%, potassium 0.73%, calcium monoxide 1.02% and ferric oxide 82.15ppm respectively. The content of zinc ranged from 19.80ppm to 103.02ppm and the average was 34.59ppm ; this value showed some differences than other elements were, and the mean content of magnesium was 0.25%. The cadmium content showed 0.31ppm copper 4.95ppm, and plumbum 20.47ppm respectively. As above results, we could say that there was no health problems with local products, if we use a the herb medicine.

근대건축의 형성 및 변천과정에 관한 연구-부산시의 근대건축을 중심으로-

정이순(Jung. Yi-Soon),박철언(Park. Cheol-Eun),김경민(Kim. Kyoung-Min),이광석(Lee. Kwang-Seok),정량부(Chung. Yang-Boo) 대한건축학회 2004 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.24 No.1

This study is investigated modern architecture in central Busan, built since Japanese colonial period that they opened the port Busan in 1876 until 1960's Korea's economical stability period. Even though many modern buildings were built after opened the port, there is remaining only a few architecture in the present Busan. Futhermore, there is only one modern architecture designated as an important cultural property in Busan. Therefore, this study is investigated the present modern architecture and researched how to preserve the architecture in the future. After the investigation and analysis, this study lead to understand whether some of investigated buildings is able to be the cultural property.

작약종자(芍藥種子)의 채종시기(採種時期)와 후숙(後熟)이 출아(出芽)에 미치는 영향(影響)

정상환,서동환,김기재,이광석,최부술,김용한 한국약용작물학회 1993 한국약용작물학회지 Vol.1 No.1

본 연구는 1991년부터 1992년까지 2개년간 경상북도 농촌진흥원 특용작물 시험포장에서 풍기종과 의성종을 공시하여 채종시기와 종자 후숙방법별 100립중과 출현율을 경시적으로 조사한 바 그 결과를 요약하면 다음과 같다. 1. 풍기종은 의성종에 비해 100립중이 무거운 대립 종이었는데 두 품종 모두 7월 25일경 100립중이 최대가 되었고 이후 점차 감소되어 7월 25일 이후 종자가 등숙되는 시기로 판단되었다. 2. 채종시기에 따른 출현율은 풍기종이 7월 5일 채종한 종자에서 7.8%의 출현율을 나타내었고 의성종은 10일정도 늦었는데 두 품종 모두 8월 15일 채종에서 평균 출현율은 풍기종이 96.7%, 의성종은 94.0%로 가장 높았다. 3. 종실채종과 협실채종에서 후숙시킨 것은 후숙시키지 않고 즉시 파종한 것 보다 출현율이 높았는데 특히, 7월 5일~8월 5일 사이의 조기 채종에서 출현율이 높고 8월(月) 15일(日) 이후 채종에서 일정한 경향은 없었다. 또한 종실 및 협실 후숙에 있어서 7월 5일과7월 15일 채종한 것은 10일간 후숙한 것보다 20~30일 후숙시킨 것이 출현율이 약간 높은 경향이고 7월 25일 이후 채종에서는 차이를 볼 수 없었다. This study was carried out to identify the effect of seed gathering time and after-ripening on Paeonia lactiflora Pall (PL) seed emergence, and to establish optimal seed gathering time and sowing time. We used two local cultivar of PL ; Punggi and Uisung. Seeds were gathered 6 times from 5th July to 25th August in 1992. The seeds of Punggi local cultivar were planted by the planting density of 10 × 15cm after treatment of 7 ways ; without after-ripening, with after-ripening for 10, 20, 30 days without or with capsule. We investigated the change of 100 grains weight of PL seed by the passage of time and emergence rate after treatment. The seed weight of Punggi was heavier than that of Uisung and the seed weight was maximzed at 25th July both of the two, and then decreased by the passage of time. The seed emergence rate of Punggi gathered at 5th July was showed 7.8% and the seed emergence of Uisung was later 10 days than that of Punggi. The maximum emergence rate of two local cultivars was the highest in gathering the seeds on the 15th of August. In gathering the seeds without and with capsule, the emergence rate of seeds sowed with after-ripening was higher than that of seeds sowed immediately after gathering the seeds without after-ripening when the seeds gathered between 5th July and 5th August. In after-ripening with out and with capsule, the emergence rate of 10 days after-ripening seeds was less than that of 20 and 30 days after-ripening seeds after the seeds gathered on the 5th and 15th of July. Difference of the emergence rate of seeds by after-ripening time did not show when the seeds gathered after 25th July.

식방풍(植防風)의 파종기(播種期), 피복(被覆), 재식밀도(栽植密度)에 따른 생육(生育)과 수양(收量) 변화(變化)

정상환,김기재,서동환,이광석,최부술 한국약용작물학회 1994 한국약용작물학회지 Vol.2 No.2

본 연구는 1991년부터 1992년까지 2년간 경상북도 농촌진흥원 특용작물 시험포장에서 봉화 지방종의 식방풍을 공시하여 무피복 파종시기 및 피복 재료와 흑색비닐피복 파종기, 재식밀도를 구명키 위해 시험한 결과를 요약하면 다음과 같다. 1. 무피복 파종기는 관행 3월 30일 파종보다 3월 20일 파종이 지상부 및 지하부 생육이 양호하였고 건근수량이 8%나 증수되었다. 2. 흑색비닐피복이 무피복에 비해 출현기간이 단축되고 주근장, 근직경, 건근비율이 높아 건근 수량이 10%나 증수되었다. 3. 흑색비닐 파종적기는 관행 3월 30일의 10a당 건근수량이 548kg인데 비해 3월 20일 파종에서 6% 증수되었다. 4. 식방풍의 재식밀도는 관행 30×20cm의 10a당 건근수량이 388kg인데 비해 20×15cm가 50% 증수되었으며 10a당 재식주수는 3.333주이었다. This experiment was carried out in the field to investigate the effects of sowing time, mulching materials and planting density on the growth and root yield of Peucedanum japonicum. The optfimum planting time for yield increase at Kyungbuk area whether the plant was grown under non-mulching or black P. E. mulching condition. Black polyethylene (P. E) film mulching was effective to promote emergence and growth, and dry root yield in the P. E. mulching was 10% higher than that in the non-mulching condition. The yield in the 20×15cm planting density was 50% higher than that in the conventional 30×20cm.

Diagnostic accuracy of prostate-specific antigen below 4 ng/mL as a cutoff for diagnosing prostate cancer in a hospital setting: A systematic review and meta-analysis

김연,정재흥,한웅규,황의창,노윤미,이나래,윤지은,이광석,이상협,이학민,유수연 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.3

Purpose: A prostate-specific antigen (PSA) cutoff of 4 ng/mL has been widely used for prostate cancer screening in population-based settings. However, the accuracy of PSA below 4 ng/mL as a cutoff for diagnosing prostate cancer in a hospital setting is inconclusive. We systematically reviewed the accuracy of PSA below 4 ng/mL cutoff in a hospital setting. Materials and Methods: We systematically reviewed the literature by searching major databases until March 2020, and a meta-analysis and quality assessment were performed. Results: A total of 11 studies were included at the completion of the screening process. The meta-analysis showed a sensitivity of 0.92 and a specificity of 0.16 for a PSA cutoff below 4 ng/mL. The area under the hierarchical summary receiver operating characteristic curve was 0.87, the positive likelihood ratio was 1.23, the negative likelihood ratio was 0.46, and the diagnostic odds ratio was 2.64. PSA sensitivities and specificities varied according to the cutoff range: 0.94 and 0.17 for 2 to 2.99 ng/mL, and 0.92 and 0.16 for 3 to 3.99 ng/mL, respectively. No significant differences in the sensitivity and specificity of PSA cutoffs in the range of 2 to 2.99 ng/mL and 3 to 3.99 ng/mL were found. Conclusions: Although a PSA cutoff <3 ng/mL is relatively more sensitive and specific than PSA ≥3 ng/mL, no significant differences in sensitivity and specificity were found in the diagnosis of prostate cancer. Therefore, clinicians should choose an appropriate PSA cutoff on the basis of clinical circumstances and patients’ characteristics.

연구발표논문초록 ( 공업화학 (Ⅱ) ) : 광산 용출에 의한 Builder 급 Zeolite 의 개량 점토법

이광석 (정),서정권 (정),이정민 (정),정필조 (정),박춘희 (정) ( K . S . Lee,J . K . Suh,J . M . Lee,P . J . Chong,C . H . Park ) 한국화학공학회 1988 춘계학술발표회 Vol.- No.-