광촉매 코팅 유리의 특성 조사 및 응용

나경주,김종범,김종호 全南大學校 觸媒硏究所 2003 觸媒硏究 論文集 Vol.24 No.-

Photocatalyst, which is a kind of semiconductor, generates the strong oxidation on a surface under UV light. Photocatalyst was coated on a glass to form a very thin film by the use of a dip-coater. The thickness of the coating layer could be adjusted in ㎛ order. The physico-chemical state of a TiO_2 film was investigated using nitrogen adsorption, XRD, TEM, SEM and UV-VIS techniques. The glassware coated with TiO_2 photocatalyst exhibited the decomposing activities in the methyleneblue, chloroform and toluene due to the photo-oxidation.

청색 사파이어에 대한 광물학적 및 변색 연구

나경주,김원사,김문영,장영남,배인국 한국광물학회 1992 광물과 암석 (J.Miner.Soc.Korea) Vol.5 No.1

靑色 사파이어의 熱處理와 分光學的 特性

나경주,김원사,김문영,배인국,장영남 충남대학교 기초과학연구소 1994 연구논문집 Vol.14 No.-

For the blue sapphires from Santung, China, the color change before and after has been investigated by UV-Visible spectrophotometry method. The blue sapphires from Shantung show four groups of absorption bands: the bands A (374, 386 and 450 ㎚) being attributed to single Fe^3+ ion, the band B (560, 579 and 704 ㎚) to Fe^2+/Ti^4+ pairs, the band C (∼800 ㎚) to Fe^2+/Fe^3+ pairs, and the D (528 ㎚) to Ti^3+ dd transitions. From those UV-VIS characteristics the origin of blue color of the sapphires is confirmed to be attributed by the factors such as Fe^2+/Fe^3+ and Ti^3+/Ti^4+. The absorption spectra of natural blue sapphires before and after heat treatment show distintive features, comparing with those of sapphires from other localities: the bands of 689 ㎚ and of Cr^3+ are not recorded on the spectra of sapphires from Shantung. The band (492 ㎚), which resulted from Ti^3+, is not shown and the intensity of the band 528 ㎚ decreases after the heat treatment. Decoloration of ink-blue sapphires are found to be successful by heat treatment with the control of annealing and atmosphere. During the diffusion process the excess components of impurities contained originally in the host crystal were expelled to the surface of crystals, enhancing the transparency of the crystals noticeably.

珍島아리랑 形成攷

地春相,羅景株 全南大學校 湖南文化硏究所 1988 호남학 Vol.18 No.-

공공건축물에서의 지열이용방법에 관한 연구

나경주 ( Kyoung Ju Na ),윤경섭 ( Kyeng Sup Yoon ),임만택 ( Mann Taek Lim ) 조선대학교 공학기술연구원 2011 공학기술논문지 Vol.4 No.4

The building to be examined has load capacity of cooling (259 kw), heating (316 kw) and geothermal capacity of cooling (333.8 kw) and heating (335.4 kw). In the process of design, first internal load and ventilation load of building were calculated with data such as insulation and finishing materials. Second, thermal conduction test was conducted for the installation of PE pipe for underground heat exchanger and water circulation for 2,882 min. Then heat exchanger quantity, drilled hole quantity and geothermal heat pump capacity were calculated with thermal conduction rate (2.83 W/mK). Third, geothermal circulating pump, hot and cold water circulating pump, expansion tank, buffer tank and apparatus were calculated with the estimated load. All equipments were arranged in machinery room and piping connected with each equipment. As a result of employing geothermal system to the building and comparing the system with existing urban gas energy consumption, it was found that the energy consumption and energy-saving rates of each season was varied. And this study confirmed the effect of energy saving effects of 7.1~37% compared to existing urban gas heating and cooling system. In addition, cooling tower to be installed on the front of the building resulted ill block noise and prevent civil complaint. Moreover, the effects of promoting the use of new and renewable energy to residents were also great.

靑色 사파이어의 熱處理와 分光學的 特性

나경주(Kyung Ju Na),김원사(Won Sa Kim),김문영(Mun Young Kim),배인국(In Kook Bae),장영남(Young Nam Jang) 대한자원환경지질학회 1993 자원환경지질 Vol.26 No.1

For the blue sapphires from Santung, China, the color change before and after has been investigated by UV-Visible spectrophotometry method. The blue sapphires from Shantung show four groups of absorption bands: the bands A (374, 386 and 450 nm) being attributed to single Fe³⁺ ion, the band B (560, 579 and 704 nm) to Fe²⁺/Ti⁴⁺ pairs, the band C (~800 nm) to Fe²⁺/Fe³⁺ pairs, and the D (528 nm) to Ti³⁺ d-d transitions. From those UV-VIS characteristics the origin of blue color of the sapphires is confirmed to be attributed by the factors such as Fe²⁺/Fe³⁺ and Ti³⁺/Ti⁴⁺. The absorption spectra of natural blue sapphires before and after heat treatment show distintive features, comparing with those of sapphires from other localities: the bands of 689 nm and of Cr³⁺ are not recorded on the spectra of sapphires from Shantung. The band (492 nm), which resulted from Ti³⁺, is not shown and the intensity of the band 528 nm decreases after the heat treatment. Decoloration of ink-blue sapphires are found to be successful by heat treatment with the control of annealing and atmosphere. During the diffusion process the excess components of impurities contained originally in the host crystal were expelled to the surface of crystals, enhancing the transparency of the crystals noticeably.

포기조에서 산기관의 설치위치가 용존산소에 미치는 영향 연구

나경주 ( Kyeong-ju Na ),박혜윤 ( Hye-yun Park ),이채영 ( Chaeyoung Lee ) 한국수처리학회 2021 한국수처리학회지 Vol.29 No.4

Currently, countries worldwide are trying to reduce greenhouse gases, and Korea also attempts to decrease industrial greenhouse gas emissions. Aeration is the most energy-demanding process in a sewage treatment facility. Improvements in the aeration process's efficiency will significantly contribute to national goals and climate change response. We conduct the aeration performance test to derive the optimum conditions for the diffuser arrangement and its installation depth in the aeration tank. The ball-type diffusers are installed at about 1/3 level (900 mm below the water surface) and 2/3 level (1,800 mm below the water level) of the water tank. We observed the change in aeration tank dissolved oxygen (DO) concentration with the blown air volume and time. The average increase in DO concentration ranged from 1.13 mg/L to 1.73 mg/L when aeration was conducted at the middle of the aeration tank. In contrast, the average increase in DO concentration ranged from 0.52 mg/L to 1.04 mg/L when aeration devices were installed at the bottom of the aeration tank. These results indicated that installing diffusers in the middle depth of the aeration tank was more effective for oxygen delivery and power requirement. The average air power required to drive the DO between 0.5 mg/L and 3.0 mg/L for an hour is found as 0.42 kWh and 0.38 kWh for the bottom and middle part of the tank, respectively. The results show 9.5% energy saving for aeration in the middle. The results reveal that the lower the depth of the aeration diffuser installation, the better the oxygen delivery. Therefore, it will be possible to construct an aeration system with better energy efficiency when aeration diffusers are installed at low-water-depths.

PCM 함침 경량골재를 이용한 열에너지 저장 콘크리트의 열사이클링 시험에 대한 연구

경주현,홍선기,나상빈,차승환,김현 한국공업화학회 2022 한국공업화학회 연구논문 초록집 Vol.2022 No.1

인공자수정 육성및 광물학적 보석학적 연구

김원사,이선숙,나경주 한국지구과학회 1991 韓國地球科學會誌 Vol.12 No.1

Synthetic amethyst grown from hydrothermal method and subsequently irradiated with gamma ray was investigated by polarizing microscopy, emission spectroscopy, atomic absorption spectroscopy, X-ray diffraction electron microscopy, infrared absorption spectroscopy, heating and freezing microscopy, density balance, and optical refractometry. Natural amethysts collected from Sokrisan, Eonyang, and Brazil were also studied to compare their mineralogical and gemmological properties with those of the synthetic counterpart. Synthetic and natural amethysts show exactly or nearly identical properties in specific gravity, refractive index, crystal structure, and chemical composition. In contrast, UV-visible spectrometry and I. R. spectrometry data, solid and fluid inclusion features, and color distribution differ considerably which may be used in differentiating the synthetic from its natural equivalents.

영지버섯과 아까시흰구멍버섯의 판별을 위한 미토콘드리아 유전체 기반 InDel 마커 개발

안화용,구현조,김은경,정지란,나경주 한국약용작물학회 2023 한국약용작물학회지 Vol.31 No.5

Background: Ganoderma lucidum and Perenniporia fraxinea are morphologically similar, mak- ing them difficult to distinguish when cut into pieces or powdered. Ganoderma lucidum is a more effective medicinal mushroom than P. fraxinea, but it is expensive, so there is a strong possibility that similar shaped mushrooms are mixed and sold together. Therefore, molecular biological mark- ers that can differentiate G. lucidum from P. fraxinea are needed. Methods and Results: We selected two polymorphic insertion-deletion (InDel) sites and one poly- morphic InDel site from the cox1 and rnl genes within the mitochondrial DNA, respectively, and designed primers using flanking sequences that surrounded these polymorphic sites. We performed a polymerase chain reaction (PCR) to validate these markers. Three InDel markers were developed to differentiate between G. lucidum and P. fraxinea: GlPf_INDEL01, GlPf_INDEL02, and GlP- f_INDEL04. Conclusions: The three InDel markers developed in this study combined with a simple PCR anal- ysis easily distinguished G. lucidum from P. fraxinea.