기상장 수치모의를 이용한 김해지역 대기질 예측

이화운,정우식,임헌호,이강열,노순아 부산대학교 환경문제연구소 2003 環境硏究報 Vol.21 No.-

For the purpose of prediction air quality in Kimhae area, ISC3 and UAM were used. As the study area is located in a coastal area, the atmospheric flow is strong1y affected by the sea breeze. The air quality model results show that the dirunal variation pattern of pollutants is consistent with observed spatial and temporal features, as a whole.

남제주 화력발전소의 증설과 저감대대책의 영향 분석

이화운,김유근,정우식,오은주,임헌호,노순아,반수진,최현정,김민선,김헌숙 부산대학교 환경문제연구소 2002 環境硏究報 Vol.20 No.-

In the view of the results investigated the effect of air pollutants that is emitted from a new generator facilities, the total estimated concentration which is the summation of a contributional concentration and observational concentration is much less than that of atmospheric environment criterion for the air pollutants. So we can predict that the operation of the new generator facilities with mitigation equipment don't seriously affect around environment. At the same time, we compared the contributional concentration of before mitigation equipment with that of after it to examine the decreasing amount due to mitigation equipment. The result showed that the concentration of SO2, NO2 and PM-10 is reduced to 25%, 30% and 26% of original value, respectively.

[논문]감천댐 건설에 따른 기상변화 연구

이화운,정우식,이귀옥,임헌호,백승주 부산대학교 환경문제연구소 2004 環境硏究報 Vol.22 No.-

In order to investigate the variation of meteological factors induced by construction of dam, the prediction model, WQRRS, is used. As a result, the effect of Dam construction showed that the amount of evaporation increases because of broad water surface area. Therefore, nighttime relative humidity is raised, and annual foggy days are increased more than 7days and sunshine hours are decreased.

Single-material zinc sulfide bi-layer antireflection coatings for GaAs solar cells.

Leem, Jung Woo,Jun, Dong-Hwan,Heo, Jonggon,Park, Won-Kyu,Park, Jin-Hong,Cho, Woo Jin,Kim, Do Eok,Yu, Jae Su Optical Society of America 2013 Optics express Vol.21 No.5

<P>We demonstrated the efficiency improvement of GaAs single-junction (SJ) solar cells with the single-material zinc sulfide (ZnS) bi-layer based on the porous/dense film structure, which was fabricated by the glancing angle deposition (GLAD) method, as an antireflection (AR) coating layer. The porous ZnS film with a low refractive index was formed at a high incident vapor flux angle of 80 in the GLAD. Each optimum thickness of ZnS bi-layer was determined by achieving the lowest solar weighted reflectance (SWR) using a rigorous coupled-wave analysis method in the wavelength region of 350-900 nm, extracting the thicknesses of 20 and 50 nm for dense and porous films, respectively. The ZnS bi-layer with a low SWR of ~5.8% considerably increased the short circuit current density (J(sc)) of the GaAs SJ solar cell to 25.57 mA/cm(2), which leads to a larger conversion efficiency (η) of 20.61% compared to the conventional one without AR layer (i.e., SWR~31%, J(sc) = 18.81 mA/cm(2), and η = 14.82%). Furthermore, after the encapsulation, its J(sc) and η values were slightly increased to 25.67 mA/cm(2) and 20.71%, respectively. For the fabricated solar cells, angle-dependent reflectance properties and external quantum efficiency were also studied.</P>

Plasmonic photocatalyst-like fluorescent proteins for generating reactive oxygen species

Leem Jung Woo,Kim Seong-Ryul,Choi Kwang-Ho,Kim Young L. 나노기술연구협의회 2018 Nano Convergence Vol.5 No.8

The recent advances in photocatalysis have opened a variety of new possibilities for energy and biomedical applications. In particular, plasmonic photocatalysis using hybridization of semiconductor materials and metal nanoparticles has recently facilitated the rapid progress in enhancing photocatalytic efficiency under visible or solar light. One critical underlying aspect of photocatalysis is that it generates and releases reactive oxygen species (ROS) as intermediate or final products upon light excitation or activation. Although plasmonic photocatalysis overcomes the limitation of UV irradiation, synthesized metal/semiconductor nanomaterial photocatalysts often bring up biohazardous and environmental issues. In this respect, this review article is centered in identifying natural photosensitizing organic materials that can generate similar types of ROS as those of plasmonic photocatalysis. In particular, we propose the idea of plasmonic photocatalyst-like fluorescent proteins for ROS generation under visible light irradiation. We recapitulate fluorescent proteins that have Type I and Type II photosensitization properties in a comparable manner to plasmonic photocatalysis. Plasmonic photocatalysis and protein photosensitization have not yet been compared systemically in terms of ROS photogeneration under visible light, although the phototoxicity and cytotoxicity of some fluorescent proteins are well recognized. A comprehensive understanding of plasmonic photocatalyst-like fluorescent proteins and their potential advantages will lead us to explore new environmental, biomedical, and defense applications.

Tunable distributed Bragg reflectors with wide-angle and broadband high-reflectivity using nanoporous/dense titanium dioxide film stacks for visible wavelength applications.

Leem, Jung Woo,Guan, Xiang-Yu,Yu, Jae Su Optical Society of America 2014 Optics express Vol.22 No.15

<P>Highly-tolerant distributed Bragg reflectors (DBRs) based on the same materials consisting of nanoporous/dense titanium dioxide (TiO2) film pair structures with wide-angle and broadband highly-reflective properties at visible wavelengths are reported. For a high refractive index contrast, the two dense and nanoporous TiO2 film stacks are alternatingly deposited on silicon (Si) substrates by a oblique angle deposition (OAD) method at two vapor flux angles (θα) of 0 and 80 for high and low refractive indices, respectively. For the TiO2 DBRs at a center wavelength (λ(c)) of 540 nm, the maximum level in reflectance (R) band is increased with increasing the number of pairs, exhibiting high R values of > 90% for 5 pairs, and the normalized stop bandwidth (?λ/λ(c)) of ~17.8% is obtained. At λ(c) = 540 nm, the patterned TiO2 DBR with 5 pairs shows an uniform relative reflectivity over a whole surface of 3 inch-sized Si wafer and a large-scalable fabrication capability with any features. The angle-dependent reflectance characteristics of TiO2 DBR at λ(c) = 540 nm are also studied at incident angles (θ(inc)) of 20-70 for p-, s-, and non-polarized lights in the wavelength region of 350-750 nm, yielding high R values of > 70.4% at θ(inc) values of 20-70 for non-polarized light. By adjusting the λ(c)/4 thicknesses of nanoporous and dense films, for λ(c) = 450, 540, and 680 nm, tunable broadband TiO2 DBRs with high R values of > 90% at wavelengths of 400-800 nm are realized.</P>

Visible light biophotosensors using biliverdin from Antheraea yamamai

Leem, Jung Woo,Allcca, Andres E. Llacsahuanga,Chen, Junjie,Kim, Seong-Wan,Kim, Kee-Young,Choi, Kwang-Ho,Chen, Yong P.,Kim, Seong-Ryul,Kim, Young L. The Optical Society 2018 Optics express Vol.26 No.24

Silk is a Biomedical Metamaterial: An Oxymoron?

Jung Woo LEEM,Jongwoo PARK,Seong-Wan KIM,Young L. KIM 한국생물공학회 2021 한국생물공학회 학술대회 Vol.2021 No.10

As protein-based biopolymers produced by spiders and silkworms, silk is a fascinating biomaterial that has been extensively studied for numerous biomedical applications. Several studies show that silk proteins can be reinforced to superior material properties that often do not exist in naturally occurring materials. This idea has an analogy with the concept of metamaterials and metastructures. Research on metamaterials and metastrcutures is centered in constructing materials to have user-designed atypical responses that often do not exhibit in nature. Optical metamaterials are often realized by controlling the electric and magnetic properties, not limited to negative refractive index and invisibility cloaks. Mechanical metamaterials take advantage of artificially engineered structures to determine mechanical properties, relatively independent of material compositions. On the other hand, typical metamaterials are not intended for biomedical applications and their construction primarily relies on exotic materials and complex nanofabrication and nanomanufacturing. In this talk, we argue that the concept of reinforced or superior silk can be extended to a type of metamaterials. In other words, reinforced silk produced by transgenic silkworms and silkworms fed with special diets could be considered as biomedical metamaterials that are designed for direct utilizations for biological and medical applications. In particular, metamaterial-like silk can serve as an ab initio foundation for opening immediate applications. Reactive oxygen species (ROS)-generating fluorescent silk will offer immediately exploitable and scalable photocatalyst-like biomaterials. The ROS generation and the photoelectric conversion are two sides of the same coin in terms of redox reactions and electrochemistry. As light-fluorescent protein interactions are often understood based on quantum mechanics, fluorescent protein-expression silk could provide an alternative model system for studying quantum biology and quantum biophotonics. Silkworm transgenesis and diet-enhanced silk production can potentially guide synthetic biology approaches to enable the production of superior synthetic silk.

Association of serum C1q/TNF-related protein-9 concentration with arterial stiffness in subjects with type 2 diabetes.

Jung, Chang Hee,Lee, Min Jung,Kang, Yu Mi,Jang, Jung Eun,Leem, Jaechan,Lee, Yoo La,Seol, So Mi,Yoon, Hae Kyeong,Lee, Woo Je,Park, Joong-Yeol Issued for the Endocrine Society by the Williams W 2014 The Journal of clinical endocrinology & metabolism Vol.99 No.12

<P>Although recent animal studies have suggested that C1q/TNF-related protein-9 (CTRP9) is more likely to be involved in the regulation of vascular function, more specifically atherosclerosis, in rodents, little is known about whether serum CTRP9 level is associated with atherosclerosis in humans.</P>

Broadband wide-angle antireflection enhancement in AZO/Si shell/core subwavelength grating structures with hydrophobic surface for Si-based solar cells.

Leem, Jung Woo,Song, Young Min,Yu, Jae Su Optical Society of America 2011 Optics express Vol.19 No.5

<P>Broadband wide-angle antireflection characteristics of aluminum-doped zinc oxide (AZO)/silicon (Si) shell/core subwavelength grating (SWG) structures with a hydrophobic surface, together with theoretical prediction using a rigorous coupled-wave analysis simulation, were investigated for Si-based solar cells. The AZO films with different thicknesses were deposited on Si SWGs by rf magnetron sputtering method, which forms a shell/core structure. The AZO/Si shell/core SWGs reduced significantly the surface reflection compared to the AZO films/Si substrate. The coverage of AZO films on Si SWGs improved the antireflective property over a wider incident angle. The AZO/Si shell/core SWG structure with a 200 nm-thick AZO layer deposited at an rf power of 200 W exhibited a water contact angle of 123°. This structure also exhibited a low average reflectance of ~2% over a wide wavelength range of 300-2100 nm with a solar weighted reflectance of 2.8%, maintaining a reflectance of < 9.2% at wavelengths of 300-2100 nm up to the incident angle of 관(i) = 70°. The effective electrical properties of AZO films in AZO/Si shell/core SWGs were also analyzed.</P>