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.

APACHE III 시스템을 이용한 병원간 중환자실 치료결과 비교분석

이덕희,노미영,김병성,Lee, Duk-Hee,No, Mee-Young,Kim, Byung-Sung 대한예방의학회 1994 Journal of Preventive Medicine and Public Health Vol.27 No.3

The objective of this study was to evaluate outcome for the patients of the intensive care unit, using APACHE III prognostic system. We prospectively collected the information of 429 patients in intensive care units at 2 tertiary care hospitals and 4 secondary care hospitals in PUSAN who had been admitted from December 1, 1993 to February 28, 1994. The results were as follows. 1. APACHE III scores were various from 0 to 173. But the distribution of the scores were similar between tertiary care hospitals and secondary care hospitals. 2. The mortality rate significantly increased as APACHE III score rised (p<0.001). Within the interval of same score, generally, the mortality of operative patients was higher in secondary care hospitals but in the case of nonoperative patients higher in tertiary care hospitals. 3. When the tertiary care hospitals compared with secondary for ratio of the predicted mortality rate to the actual mortality rate, there was little difference. 4. When we compared the 6 hospitals, one hospital had significantly better results and another hospital was significantly inferior (p<0.05).

LED 폐자원 재활용: 현황과 향후 방향

이덕희,오현경,박경수,Duk-Hee Lee,Hyeon-Kyung Oh,Kyung-Soo Park 한국자원리싸이클링학회 2024 資源 리싸이클링 Vol.33 No.1

Owing to technological advancements and energy-saving policies, the demand for LED is increasing, leading to rapid industry expansion. Consequently, efficient recycling of accumulated LED waste has become a growing social concern, and current recycling status of LED waste resources and future directions were reviewed. Currently, waste LED recycling is focused on Ga recovery. Therefore, the development of integrated recycling technologies such as pre-treatment and concentration/recovery of high valued materials is necessary. In this study, we investigated the status and recycling technologies of waste LED and presented prospects.

복합유기용제의 누적 폭로 정도에 따른 신경행동학적 변화

이덕희,박인근,김진하,이용환,강성규,김두희,Lee, Duk-Hee,Park, In-Geun,Kim, Jin-Ha,Lee, Young-Hawn,Kang, Sung-Gye,Kim, Doo-Hie 대한예방의학회 1995 Journal of Preventive Medicine and Public Health Vol.28 No.2

A cross sectional study was performed to evaluate the neurobehavioral effects of chronic exposure of complex organic solvents, using NCTB(Neurobehavioral Core Test Battery) recommended by WHO(World Health Organization). Forty female shoe factory workers and twenty-two controls matched with age were participated. The tests were performed in the morning before start of work, to exclude the effects of acute exposure. Workers were exposed mainly to toluene, methyl ethyl ketone, n-hexane, cyclo-hexane, dichloroethylene, trichloroethylene, benzene, xylenes etc. The ranges of present solvent exposure of hygienic effect were $0.46\sim0.71$ in the process using adhesives indirectly, and $1.83\sim2.39$ in the process using it directly. We reclassified the subjects, according to cumulative exposure. It showed significantly poorer performances in high exposed group on Santa Ana Dexterity and Benton Visual Retention, compared with control group. After controlling confounder, the significances were still remained. But, further cohort studies, having the information of personal exposure dose from entering a factory, are required to clarify the effects of chronic exposure of complex organic solvents in relation to dose and duration of exposure.

저농도 혈중 카드뮴과 아연이 혈압에 미치는 영향

이덕희,김두희,Lee, Duk-Hee,Kim, Doo-Hie 대한예방의학회 1992 예방의학회지 Vol.25 No.2

A case-control study was conducted to investigate the relationship between blood cadmium, blood zinc and cadmium/zinc ratio and hypertension. Eighty-three hypertensive and seventy-seven normotensive study subjects matched for age and sex were selected from the workers who had no history of job-related cadmium exposure, in Ulsan city and it's vincinity, Korea. The blood cadmium in hypertensive group was $2.90{\eta}g/mL$, which was significantly higher than that of control group, $1.99{\eta}g/mL$(P<0.01). After stratifing for smoking and age variables, the relationship was still remained. The blood cadmium/zinc ratio in hypertensive group was 2.46, which was significantly higher than that of control group, 1.65(P<0.01), After stratifing for smoking and age variables, the relationship was still remained. There was no significant differance in blood zinc between hypertensive and control group. On multiple logistic regression analysis, the blood cadmium/zinc ratio is highly significant than blood cadmium. In conclusion, there is the possible relationship between blood cadmium level which has been known to be within normal limits and hypertension. But, futrher cohort studies to define the effect of cadmium on human hypertension are required. 혈중 카드뮴, 아연 및 아연에 대한 카드뮴의 비와 혈압 간의 관련성을 보기 위하여 울산 및 그 인근지역에서 직업적으로 카드뮴에 폭로된 경력이 없는 근로자중 고혈압군 83명과 대조군 77명을 성과 연령에 대해 빈도수 짝짓기로 선택하여 얻은 결과는 다음과 같다. 평균 혈중 카드뮴치는 고혈압군이 $2.90{\eta}g/ml$로, 대조군의 $1.99{\eta}g/ml$보다 유의하게 높았으며(P<0.01), 흡연 정도와 연령에 대해 층화분석을 한 후에도 모든 층에서 고혈압군이 유의하게 놀았다. 혈중 아연에 대한 카드뮴의 비도 고혈압군이 2.46. 대조군의 1.65로 유의하게 높았으며(P<0.01), 흡연정도와 연령에 대해 층화분석을 한 후에도 모든 층에서 고혈압군이 유의하게 높았다. 혈중 아연치는 두 군 사이에 유의한 차이를 볼 수 없었다. 홉연, 연령, 음주, 크레아티닌 및 ${\beta}2$-마이크로글로블린 등의 혼란변수를 고려한 다변량 분적상 혈중 아연에 대한 카드뮴의 비가 가장 유의한 변수로 나타났다. 본 연구를 통하여 볼 때 정상치 범위 이내의 혈중 카드뮴치도 고혈압과 관련성이 있을 것으로 생각되며, 특히 아연치에 대한 상대적인 카드뮴치의 상승이 카드뮴의 절대치보다 더욱 중요한 인자일 것으로 생각된다. 그러나 명확한 인과관계를 밝히기 위하여서는 코호트 연구가 필요할 것으로 생각된다.

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.

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.

AOD공정으로 재활용된 니켈합금의 산소주입량에 따른 조직과 기계적 성질 변화

이덕희,우기도,강황진,윤진호,Lee, Duk-Hee,Woo, Kee-Do,Kang, Whang-Jin,Yoon, Jin-Ho 한국자원리싸이클링학회 2016 資源 리싸이클링 Vol.25 No.2

본 연구에서는 Inconel 713C 스크랩을 원료로 아르곤-산소 탈탄 공정을 이용하여 니켈계 초내열합금을 재활용 하였다. 아르곤-산소 탈탄 공정에서 아르곤은 1,000 sccm으로 지속적으로 주입되었고 산소는 100, 250, 500 sccm의 유량으로 10, 20, 30 분씩 주입되었다. 산소 주입 초기 단계에서는 산소 양이 증가하면서 Al, Cr, 및 Mo 함량은 증가하였고 탄소 함량은 감소하였다. 그리고 Al 함유량은 탄소의 반응이 끝난 후 Al, Cr 등의 원소와 산화가 일어났기 때문에 첨가원소와 탄소의 반응에 의해 감소하였다. 결과적으로, Al 함유량이 감소하였기 때문에 ${\gamma}^{\prime}$상이 줄어들었으며 이는 Al이 ${\gamma}^{\prime}$을 형성하는 주요 원소이기 때문이다. 또한, 탄소의 양이 줄어들면서 탄화물도 줄어들었으며 산소가 과잉 공급된 시료의 기계적인 물성(강도, 경도 등)은 감소하게 된다. In this study, the Ni base superalloy was recycled by Argon oxygen decarburization(AOD) process using an inconel 713C scrap. During AOD process, argon gas was continuously injected 1,000 sccm and oxygen gas was injected into 10, 20 and 30 minutes of 100, 250 and 500 sccm.. In early stage of oxygen injection, the oxygen dose increased with increasing Al, Cr, and Mo content and decreasing C content. And Al content was decreased by carburization with added elements in late stage Because of oxidation was occurred with Al, Cr etc. after the reaction of carbon has been finished. From the results, the ratio of ${\gamma}^{\prime}$ phase reduced due to decreasing of Al content for that reason Al is the main element to form the ${\gamma}^{\prime}$ phase. Also carbide reduced owing to decreasing of C content so the mechanical properties of the specimens excessively injected by excess $O_2$ gas were decreased.

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.

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.