LED 폐자원의 재활용 현황

이덕희,신동윤,김태형,이찬기,박경수,이기웅,이재령,Lee, Duk-Hee,Shin, Dongyoon,Kim, Tae-Hyung,Lee, Chan-Gi,Park, Kyung-Soo,Lee, Ki Woong,Lee, Jaeryeong 한국자원리싸이클링학회 2019 資源 리싸이클링 Vol.28 No.2

Development of technology makes LED an economical option because of lower energy consumption and better environmental impact. Because higher consumer demand the LED market is expanding rapidly due to its environment-friendly advantages. Expansion of LED application, development of various fusion technologies, the emergence of new markets, and the large-scale expansion of markets would lead to a large volume of e-waste generation with valorization potential. Currently, most of the generated waste being that landfilled and incinerated due to the absence of technology and management system. In this paper, we review the current status of LED waste recycling and analyzes the available recycling technologies.

정상 소아들의 혈중 연 농도와 지능지수와의 관련성

이덕희,이용환,김진하,박인근,한태영,장세한,Lee, Duk-Hee,Lee, Yong-Hwan,Kim, Jin-Ha,Park, In-Geun,Han, Tae-Young,Jang, She-Han 대한예방의학회 1995 Journal of Preventive Medicine and Public Health Vol.28 No.2

The association between blood lead of children and Intelligent Quotient(I.Q) was investigated in a sample of 100 boys and girls aged $6\sim8$ years from one primary school within an industrial area of Pusan. The trained undergraduates in school of public health administered an 1.0. test one by one. Parents answered a questionnaire on demographic, perinatal and socioeconomic variables. Atomic Absorbtion Spectrophotometer was used to determine blood lead levels. The geometric mean of blood lead value was $7.99{\mu}g/dl$. In total children, there was no significant relationship between blood lead level and I.Q. But in the children who were born of gestational age of less than 38 weeks, children with higher levels of blood lead performed more poorly on I.Q test with correlation coefficient from -0.68 to -0.71. But, the children who were born of gestational age of 38 weeks and more were same as total children. These results suggest that exposure to low levels of lead in the children who were born premature probably may result in impaired intelligent development. But, We think that more profound study should be performed with sufficient numbers of subjects.

급성기 허혈성 뇌경색의 자기공명영상

이덕희,이정현,Lee, Deok-Hui,Lee, Jeong-Hyeon 대한영상의학회 2004 대한영상의학회지 Vol.50 No.1

최근 뇌혈관 질환 특히 허혈성 뇌졸중에 대한 관심이 고조되고 있고, 확산강조영상의 성공적인 임상 적용은 방사선과, 신경과 의사들의 진단과 치료 패턴에 큰 변화를 몰고 온 계기가 되었다. 이러한 뇌질환에 대한 관심은 국내외적인 상황이라 우리 방사선과 의사들의 적극적인 관심이 요구되는 때라고 생각된다. 이를 계기로 급성 허혈성 뇌경색 특히 증상 발현 6시간 이내의 초급성기 환자의 진단과 치료에 있어서 MR의 역할을 살펴보고자 한다.

다종슬래그를 재활용한 Glass-Ceramic의 제조 및 물성

이덕희,신동윤,윤미정,박현서,윤진호,Lee, Duk-Hee,Shin, Dongyoon,Yoon, Mijung,Park, Hyun Seo,Yoon, Jin-Ho 한국재료학회 2016 한국재료학회지 Vol.26 No.5

Glass-ceramics were developed many years ago and have been applied in many fields such as electronics, chemistry, optics, etc. Much is already known about glass-ceramic technology, but many challenges in glass-ceramic research are still unresolved. Recently, large amounts of slag have steadily increased in the steel industry as by-products. To promote recycling of industrial waste, including steel industry slags, many studies have been performed on the fabrication of basalt-based high-strength glass-ceramics. In this study, we have fabricated such ceramics using various slags to replace high performance cast-basalt, which is currently imported. Glass-ceramic material was prepared in similar chemical compositions with commercial cast-basalt through a pyro process using slags and power plant by-product (Fe-Ni slag, converter slag, dephosphorization slag, Fly ash). The properties of the glass-ceramic material were characterized using DTA, XRD, and FE-SEM; measurements of compressive strength, Vicker's hardness, and abrasion were carefully performed. It is found that the prepared glass-ceramic material showed better performance than that of commercial cast-basalt.

One-pot 습식화학공정을 이용한 TiO₂ 중공 구조체 제조 및 광촉매 활성 연구

이덕희,박경수,박재량,이찬기,Lee, Duk-Hee,Park, Kyung-Soo,Park, Jae-Ryang,Lee, Chan-Gi 한국분말야금학회 2020 한국분말재료학회지 (KPMI) Vol.27 No.2

A facile one-pot wet chemical process to prepare pure anatase TiO₂ hollow structures using ammonium hexafluorotitanate as a precursor is developed. By defining the formic acid ratio, we fabricate TiO₂ hollow structures containing fluorine on the surface. The TiO₂ hollow sphere is composed of an anatase phase containing fluorine by various analytical techniques. A possible formation mechanism for the obtained hollow samples by self-transformation and Ostwald ripening is proposed. The TiO₂ hollow structures containing fluorine exhibits 1.2 - 2.7 times higher performance than their counterparts in photocatalytic activity. The enhanced photocatalytic activity of the TiO₂ hollow structures is attributed to the combined effects of high crystallinity, specific surface area (62 ㎡g^-1), and the advantage of surface fluorine ions (at 8%) having strong electron-withdrawing ability of the surface ≡ Ti-F groups reduces the recombination of photogenerated electrons and holes.

Ammonium Hexafluorotitanate 전구체로부터 습식 공정을 이용한 불소 함유 TiO₂ 나노 분말 제조 및 광촉매 특성 연구

이덕희,박재량,이찬기,김현모,박경수,Lee, Duk-Hee,Park, Jae-Ryang,Lee, Chan-Gi,Kim, Hyeon-Mo,Park, Kyung-Soo 한국분말야금학회 2018 한국분말재료학회지 (KPMI) Vol.25 No.3

F-containing $TiO_2$ nanopowders are synthesized using simple wet processes (precipitation-based and hydrothermal) from ammonium hexafluorotitanate (AHFT, $(NH_4)_2TiF_6$) as a precursor to apply as a photocatalyst for the degradation of rhodamine B (RhB). The surface properties of the prepared samples are evaluated using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The results confirm that the synthesized anatase $TiO_2$ has sphere-like shapes, with numerous small nanoparticles containing fluorine on the surface. The photocatalytic activity of F-containing $TiO_2$ compared with F-free $TiO_2$ is characterized by measuring the degradation of RhB using a xenon lamp. The photocatalytic degradation of F-containing $TiO_2$ exhibits improved photocatalytic activity, based on the positive effects of adsorbed F ions on the surface.

유기인계 농약 중독 환자에서 약물의 종류에 따른 임상 양상 및 예후의 차이

이덕희,정진희,정구영,어은경,Lee, Duk-Hee,Jung, Jin-Hee,Jung, Koo-Young,Eo, Eun-Kyung 대한임상독성학회 2007 대한임상독성학회지 Vol.5 No.1

Purpose: Organophosphorus insecticides tend to be regarded as a homogeneous single entity. We aimed to determine whether organophosphate poisoning differs by subgroups in clinical features and severity. Methods: We retrospectively reviewed medical records of all patients with acute organophophorus poisoning from January 1998 to December 2006. We investigated clinical features, Glasgow coma scale (GCS), laboratory findings, QTc intervals, management, and outcomes. Results: A total of 109 patients were included. The dimethoxy group experienced significantly longer times than the diethoxy group for ventilation duration (0.6 day vs. 0.2 day, p=0.006), ICU duration (2.0 day vs. 0.8 day, p=0.037), and total admission duration (2.8 day vs. 0.9 day, p=0.008), except in cases of dichlorvos poisoning. Also, the GCS of the dimethoxy group (except with dichlorvos) was significantly lower than for the diethoxy group (dimethoxy, $11.2{\pm}5.2$ vs. diethoxy, $13.8{\pm}2.4$, p= 0.021). QTc intervals for the dimethoxy group (except with dichlorvos) tended to be somewhat greater than for the diethoxy group (dimethoxy, $452.9{\pm}16.1\;msec$ vs. diethoxy, $429.6{\pm}40.9\;msec$). There were 65 patients with dichlorvos ingestion, and 2 of these patients (3%) died. Conclusion: When compared to the diethoxy group, the dimethoxy group of organophosphates (with the exception of dichlorvos) were associated with poorer prognostic value for indicators such as GCS, QTc interval, requirement for intubation, ICU duration, and total admission duration. Within the dimethoxy group, patients with dichlorvos poisoning had relatively better prognoses than for the other dimethoxy group organophosphates studied.

건설현장의 안전관리 개선사항이 근로자의 안전보건 증진에 미치는 영향에 관한 연구

이덕희,박종용,염희상,Lee, Duck Hee,Park, Jong Young,Youm, Hie Sang 한국재난정보학회 2021 한국재난정보학회 논문집 Vol.17 No.3

Purpose: TThis study seeks to understand the provisions of the Industrial Safety and Health Act and the Construction Technology Promotion Act and to propose measures to prevent serious industrial accidents by seeking to promote safety and health of workers through improvement of safety management at construction sites. Method: A survey was conducted on construction sites with more than 50 permanent workers (5 billion won in construction amount). The analysis of the data was conducted using the JAMOVI statistics program and based on objective data. Result: Multiple regression analysis was conducted to verify the hypothesis of this study, and the results of the analysis. The participation of workers in safety and health activities has the highest impact on the promotion of safety and health of workers. Conclusion: In order to promote safety and health of workers at construction sites, compliance with safety and health rules of workers is required and improvements should be made to allow workers to participate in safety and health activities. 연구목적: 본 연구는 산업안전보건법과 건설기술진흥법의 규정을 파악하고, 건설현장의 안전관리 개선을 통하여 근로자의 안전보건 증진방안 모색하여 중대산업재해 방지 방안을 제안하고자 한다. 연구방법: 본 연구의 표본 대상 범위는 상시 근로자 50인(공사금액 50억원) 이상의 건설현장을 대상으로 설문조사를 실시하였다. 자료의 분석은 JAMOVI 통계 프로그램을 이용하였으며, 객관적인 자료를 바탕으로 하여 분석하는 연구를 진행하였다. 연구결과: 본연구의 가설을 검증하기 위하여 다중회귀분석을 시행하였으며, 분석결과. 근로자의 안전보건 활동 참여가 근로자 안전보건 증진에 가장 높은 영향을 미치는 것으로 나타났다. 결론: 건설현장의 근로자 안전보건 증진을 위하여 근로자의 안전보건 규칙 준수가 필요하고 근로자가 안전보건 활동에 참여하도록 개선되어야 한다고 할 수 있을 것이다.

유기금속화학증착 분진(MOCVD dust)을 이용한 갈륨 함유 고순도 수용액 제조 연구

이덕희,윤진호,박경수,홍명환,이찬기,박정진,Lee, Duk-Hee,Yoon, Jin-Ho,Park, Kyung-Soo,Hong, Myung-Hwan,Lee, Chan-Gi,Park, Jeung-Jin 한국자원리싸이클링학회 2015 資源 리싸이클링 Vol.24 No.4

본 연구에서는 LED 칩 제조를 위해 이용되는 유기금속화학증착(MOCVD) 장비에서 발생하는 분진(dust)으로부터 용매추출을 통해 고순도 갈륨(Ga) 함유 수용액을 회수하는 연구를 수행하였다. 추출제 종류, 추출제의 농도 변화에 대한 연구를 통해 Ga 추출에 효과적인 추출제를 선정하고자 하였으며 다단계 추출/역추출 공정을 통해 추출 효율을 향상시켜 고순도 Ga 수용액을 제조하였다. 선행연구에서 원료에 대한 분석을 바탕으로 Ga의 추출 및 분리를 위해 PC88A, DP-8R, Cyanex 272 추출제 중 Cyanex 272를 선택하였으며 1.5M일 때 43.8%의 효율이 나타났다. 다단계 추출을 통해 Ga의 추출 효율은 83%까지 상승하였으며 0.1 M HCl을 이용한 역추출 공정으로 불순물이 없는 5N급 고순도 Ga 수용액을 제조할 수 있었다. In this study, we have investigated solvent extraction of Ga and recovery of high pure Ga solution from MOCVD dust for manufacturing of LED chip. Effect of extractan, concentration of extractant were examined for choosing the more effective extractant and high pure Ga solution was fabricated by multi-stage extraction/stripping process. For extraction/separation of Ga based on the analysis of raw-material in previous study, 3 different extractants PC 99A, DP-8R, Cyanex 272 has been investigated and the extraction efficiency of 1.5 M Cyanex 272 was 43.8%. It was conformed that extraction efficiency of Ga was 83% in multi-stage extraction and 5N high purity Ga stripping solution without impurities also obtained.

제언 - 현대의학의 잃어버린 고리: 저농도 화학물질 혼합체에 대한 만성노출

이덕희,Lee, Deok-Hui 대한산업보건협회 2020 산업보건 Vol.388 No.-