http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
이재희,임진석,박진백,Lee, Jaehee,Lim, Jin Seok,Park, Jinbaek 한국안전학회 2021 한국안전학회지 Vol.36 No.1
This study aims to analyze an influence of industrial accident on industrial productivity. We analyzed relationship among industrial accident, labor force, and industrial productivity using vector error correction model (VECM). The data used in the analysis were the number of industrial accidents, the number of workers, and index of all industry production from January 2008 to June 2017 in Korea. Finally, the industrial accidents have played a role in reducing labor force and industrial productivity.
800 MPa급 고강도강 용접금속의 미세조직 특성 비교 연구
이재희,김상훈,윤병현,김환태,길상철,이창희,Lee, Jae-Hee,Kim, Sang-Hoon,Yoon, Byung-Hyun,Kim, Hwan-Tae,Kil, Sang-Cheol,Lee, Chang-Hee 대한용접접합학회 2011 대한용접·접합학회지 Vol.29 No.1
Microstructural characteristics of two high strength (600 MPa & 800 MPa) weld metals produced by flux-cored arc welding process (FCAW) were evaluated. The 600 MPa grade weld metal was consisted of 75% acicular ferrite and 25% ferrite which was formed at relatively high temperature (grain boundary ferrite, widmanstatten ferrite, polygonal ferrite). However, the 800 MPa grade weld metal was composed of about 85% acicular ferrite and 15% low temperature forming phases (bainite, martensite). The prior austenite grain size of 800 MPa grade weld metal was decreased by solute drag force. The compositions and sizes of inclusions which are the dominant factors for the formation of acicular ferrite were analyzed by a transmission electron microscopy (TEM). In both 600 MPa and 800MPa grade weld metals, the inclusions were mainly consisted of Ti-oxide and Mn-oxide, and the average size of inclusions was $0.7{\mu}m$. The 800 MPa grade weld metal exhibited higher tensile strength and similar toughness compared with the 600 MPa grade weld metal. This result is mainly due to a higher fraction of low temperature products and a lower fraction of grain boundary ferrite in the 800 MPa grade weld metal.
미용/의료용 유연 마이크로 발광 다이오드 디바이스 제작 공정
이재희,Jae Hee Lee 한국전기전자재료학회 2023 전기전자재료학회논문지 Vol.36 No.6
마이크로 발광다이오드(LED)는 칩 사이즈가 100마이크로미터 이하인 무기발광재료로 우수한 전기적, 광학적, 기계적 성능 때문에 유연 디스플레이, AR/VR, 바이오 메디컬 분야의 차세대 광원으로 큰 주목을 받고 있다. 특히, 바이오메디컬 분야에 적용하기 위해서는 매우 작은 크기의 마이크로 LED 칩을 원하는 유연 기판에 옮기기 위한 기술이 요구되며, 실제 인간의 얼굴, 장기 등 여러 신체 부위에 적용하기 위해서는 대량의 마이크로 LED 칩을 낮은 정밀 오차, 빠른 속도, 높은 수율로 타겟 기판에 전사하는 것이 중요하다. 본 논문의 목적은 미용/의료용 유연 마이크로 LED 디바이스 제작 공정 방법을 소개하고, 이를 실제 미용/의료 산업에 적용하기 위해 필요한 마이크로 LED 전사 기술을 소개한다. 해당 기술로 제작된 유연 마이크로 LED 디바이스는 피부 질환, 암, 신경질환 등 인간 질병 치료에 널리 활용될 것으로 기대된다. Micro light-emitting diodes (LEDs), with a chip size of 100 micrometers or less, have attracted significant attention in flexible displays, augmented reality/virtual reality (AR/VR), and bio-medical applications as next-generation light sources due to their outstanding electrical, optical, and mechanical performance. In the realm of bio-medical devices, it is crucial to transfer tiny micro LED chips onto desired flexible substrates with low precision errors, high speed, and high yield for practical applications on various parts of the human body, including someone's face and organs. This paper aims to introduce a fabrication process for flexible micro LED devices and propose micro LED transfer techniques for cosmetic and medical applications. Flexible micro LED technology holds promise for treating skin disorders, cancers, and neurological diseases.
마이크로파 조사가 산화그래핀의 화학적 박리에 미치는 효과
이재희,황기완,정영훈,김의태,Lee, Jae-Hee,Hwang, Ki-Wan,Jeong, Young-Hoon,Kim, Eui-Tae 한국재료학회 2013 한국재료학회지 Vol.23 No.12
Graphene oxide has been synthesized by microwave-assisted exfoliation of graphite oxide prepared by modified Hummers method. Graphite was oxidized in a solution of $H_2O_2$ and $KMnO_4$ at $65{\sim}80^{\circ}C$, followed by 10 % $H_2O_2$ solution treatment at $80{\sim}90^{\circ}C$. The graphite oxide was exfoliated under microwave irradiation of 1 kW and was reduced to graphene effectively by hydrazine hydrate ($H_4N_2{\cdot}H_2O$) treatment. The exfoliation of graphene oxide was significantly affected by the microwave irradiation on (heating)/off (cooling) period. An on/off period of 10 s/20 s resulted in much more effective exfoliation than that of 5 s/10 s with the same total treatment time of 10 min. This can be explained by the higher exfoliation temperature of 10 s/20 s. Repetition of the graphite oxidation and exfoliation processes also enhanced the exfoliation of graphene oxide. The thickness of the final graphene products was estimated to be several layers. The D band peaks of the Raman spectra of the final graphene products were quite low, suggesting a high crystal quality.
CO<sub>2</sub> 레이저 열분해법을 이용한 실리콘 나노입자 합성 시 H<sub>2</sub> 유량이 나노입자 특성에 미치는 영향
이재희,김성범,김종복,황택성,이정철,Lee, Jae Hee,Kim, Seongbeom,Kim, Jongbok,Hwang, Taekseong,Lee, Jeong Chul 한국재료학회 2013 한국재료학회지 Vol.23 No.5
Silicon nanoparticle is a promising material for electronic devices, photovoltaics, and biological applications. Here, we synthesize silicon nanoparticles via $CO_2$ laser pyrolysis and study the hydrogen flow effects on the characteristics of silicon nanoparticles using high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), and UV-Vis-NIR spectrophotometry. In $CO_2$ laser pyrolysis, used to synthesize the silicon nanoparticles, the wavelength of the $CO_2$ laser matches the absorption cross section of silane. Silane absorbs the $CO_2$ laser energy at a wavelength of $10.6{\mu}m$. Therefore, the laser excites silane, dissociating it to Si radical. Finally, nucleation and growth of the Si radicals generates various silicon nanoparticle. In addition, researchers can introduce hydrogen gas into silane to control the characteristics of silicon nanoparticles. Changing the hydrogen flow rate affects the nanoparticle size and crystallinity of silicon nanoparticles. Specifically, a high hydrogen flow rate produces small silicon nanoparticles and induces low crystallinity. We attribute these characteristics to the low density of the Si precursor, high hydrogen passivation probability on the surface of the silicon nanoparticles, and low reaction temperature during the synthesis.
이재희,Lee, Jae-Hui 한국과학기술단체총연합회 1976 과학과 기술 Vol.9 No.11
지난 8일 하룻동안 서울시내 9개소에서 연탄가스(Co가스) 중독사고가 발생하여 11명이 목숨을 잃었으며 10월 27일에는 서울에서 일가족 4명이 목숨을 잃었고 안양에서는 남매가 목숨을 잃은 불행한 사고가 연달아 이러나고 있어 세인의 가슴을 아프게 하고 있다. 겨울이면 계절병처럼 발생되는 연탄가스(일산화탄소) 중독사고로 인한 사망자 수가 1976년도에 벌써 7백여명을 훨씬 상회하는 희생자를 내고있다. 이와같은 엄청난 인명피해는 법정전염병으로 희생되는 수보다 월등히 높은 사정이고 보면 이에 대한 대책이 시급한 바 있다. 그러면 연탄가스 중독사고예방책은 무엇인가? 필자가 수년간 연구 비교한 바에 따라 공해에 대한 문제점과 아울러 연탄가스 예방책을 소개하므로 독자에게 다소라도 도움이 되고자 한다.