• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2005년도 춘계학술대회 논문집
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• pp.237-240
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• 2005

The demand of micro electrical mechanical system (MEMS) bio/chemical sensor is rapidly increasing. To prevent the contamination of sensing area, a filtration system is required in on-chip total analyzing MEMS bio/chemical sensor. A nano-filter was mainly applied in some application detecting submicron feature size bio/chemical products such as bacteria, fungi and so on. We suggested a simple nano-filter fabrication process based on replication process. The mother pattern was fabricated by holographic lithography and reactive ion etching process, and the replication process was carried out using polymer mold and UV-imprinting process. Finally the nano-filter is obtained after removing the replicated part of metal deposited replica. In this study, as a practical example of the suggested process, a nano-dot array was replicated to fabricate nano-filter fur bacteria sensor application.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집 Vol.14 No.1
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• pp.117-120
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• 2001

A new photoalignment material PFCPMI, poly[4-(fluorocinnamate)phenylmaleimide], was synthesized and the nematic liquid crystal (NLC) aligning capabilities on the photopolymer surface. The NLC pretilt angle generated by non-UV filter method on the PFCPMI surface was higher than that of the UV filter method. A good LC alignment by non-UV filter method was observed at $150^{\circ}C$ of annealing temperature. However, the alignment defect of the NLC by UV filter method was measured above $150^{\circ}C$ of annealing temperature. Consequently, the high pretilt angle and the good LC alignment in NLC using non-UV filter method can be acheived.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 추계학술대회 논문집
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• pp.117-120
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• 2001

A new photoalignment material PFCPMI, poly [4-(fluorocinnamate) phenylmaleimide], was synthesized and the nematic liquid crystal (NLC) aligning capabilities on the photopolymer surface. The NLC pretilt angle generated by non-UV filter method on the PFCPMI surface was higher than that of the UV filter method. A good LC alignment by non-UV filter method was observed at 150\`c of annealing temperature. However, the alignment defect of the NLC by UV filter method was measured above 150$^{\circ}C$ of annealing temperature. Consequently, the high pretilt angle and the good LC alignment in NLC using non-UV filter method can be achieved.

• 한국전기전자재료학회논문지
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• 제15권5호
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• pp.423-428
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• 2002

The photoalignment material PFCPMI, poly[4-(fluorocinnamate)phenylmaleimide], was synthesized and the nematic liquid crystal(NLC) aligning capabilities on the photopolymer surface. The NLC pretilt angle geneated by non-UV filter method on the PFCPMI surface was higher than that of the UV filter method. A good LC alignment by non-UV filter method was observed at $150^{\circ}C$ of annealing temperature. However, the alignment defect of the NLC by UV filter method was measured above $150^{\circ}C$ of annealing temperatue. Consequently, the high pretilt angle and the good LC alignment in NLC using non-UV filter method can be acheived.

• 한국결정성장학회지
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• 제29권6호
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• pp.276-282
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• 2019

본 연구의 목적은 공기청정기의 극세필터(프로필터), 집진필터, 헤파(HAPA-High Efficiency Particulate Air)필터, 탈취필터 등을 사용하는 일반적인 필터의 구조를 분석하고 초미세먼지, 유해가스 및 살균 정화성능을 향상시킬 수 있는 새로운 형태의 공기정화 필터 디자인을 제시하는 것이다. 기존 단계적 여과 필터 형태에 광촉매 필터 시스템을 추가하는 방법으로 연구하였으며, 광촉매 필터는 좌우측의 UV-LED 설치 프레임과 광촉매 코팅 허니컴(honeycomb)프레임 3단 결합구조의 디자인으로 제안했다. 광촉매 필터의 살균소독 효과에 대해서는 향후 연구가 필요하며, 본 연구에서는 공기청정기에 광촉매 필터 적용 및 구조에 대하여 보고하고자 한다.

• 마이크로전자및패키징학회지
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• 제29권1호
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• pp.67-70
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• 2022

본 연구는 최근 유행하고 있는 코로나 바이러스(SARS-CoV-2) UV 살균을 위한 1차원 광자 준결정 구조 개념의 광학 필터를 설계하고 시뮬레이션 하였다. 시뮬레이터는 수치해석 프로그램으로 사용되는 MATLAB 프로그램과 직접 코딩한 연산수식을 사용하였다. 비주기(복합구조) 다중층 구조 모델을 설계한 후, 특성 계산을 위하여 다중층 구조 모델의 물성치를 천이 행렬법(TMM, Transfer Matrix Method)으로 설정하였다. 설계된 복합 다중층 구조의 MATLAB을 활용한 전산모사법을 통하여 얻은 행렬값으로부터 반사도와 투과도를 계산하였다. 이 연구의 결과로 인체에 무해하면서 코로나 바이러스 UV 살균이 가능한 253.7 nm 파장만을 투과하는 광학 필터의 제작 및 응용 가능성을 증명하였다.

• 상하수도학회지
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• 제25권6호
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• pp.861-867
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• 2011

Wastewater from crude oil reserve base usually contains large amount of non-biodegradable contaminants. The conventional wastewater treatment progress can hardly meet the regulation of wastewater effluent quality. This study investigated the removal of non-biodegradable organic contaminants in wastewater from crude oil reserve base using a pulse UV treatment. The modified process incorporating pulse UV process was set up to treat the wastewater from crude oil reserve base. The treatment process is composed with coagulation and flocculation, micro-bubble flotation, sand filter, pulse UV system, and GAC filter. The results show CODMn was effectively removed by the process with pulse UV system and it can meet the wastewater effluent regulation. The single effect of pulse UV process in CODMn removal was not significant(9~15% based on sand filtered effluent), however with the subsequent activated carbon filter the removal ratio CODMn was increased up to 28% compared to the process without pulse UV syetem.

• 소성∙가공
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• 제14권5호
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• pp.473-476
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• 2005

The demand of on-chip total analyzing system with MEMS (micro electro mechanical system) bio/chemical sensor is rapidly increasing. In on-chip total analyzing system, to detect the bio/chemical products with submicron feature size, a filtration system with nano-filter is required. One of the conventional methods to fabricate nano-filter is to use direct patterning or RIE (reactive ion etching). However, those procedures are very costly and are not suitable fur mass production. In this study, we suggested new fabrication method for a nano-filter based on replication process, which is simple and low cost process. After the Si master was fabricated by laser interference lithography and reactive ion etching process, the polymeric mold was replicated by UV-imprint process. Metallic nano-filter was fabricated after removing the polymeric part of metal deposited polymeric mold. Finally, our fabrication method was applied to metallic nano-filter with $1{\mu}m$ pitch size and $0.4{\mu}m$ hole size for bacteria sensor application.

• 한국환경보건학회지
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• 제50권3호
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• pp.201-211
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• 2024

Background: Organic ultraviolet (UV) filters are widely used in sunscreen products and have been identified as an emerging contaminant. Organic UV filters co-exist with multiple components, but their mixture toxicity remains largely unknown. Objectives: We investigated the toxicity of single and binary mixtures of commonly used UV-filters using the human adrenocarcinoma (H295R) cell line. Methods: After exposure to non-cytotoxic concentrations of avobenzone (AVO), homosalate (HS), octisalate (OS), octinoxate (OMC), and octocrylene (OC), the levels of testosterone (T) and 17β-estradiol (E2) were measured. The median effective concentration (EC₅₀) values for the E2 of the individual substances were used to determine the mixture effect of four binary combinations: OMC+AVB, OMC+HS, OMC+OS, and OMC+OC. The synergistic, additive, and antagonistic effects of the mixture were determined by calculating toxic units (TU). To examine the mechanism of mixture toxicity, eight genes involved in steroidogenesis were analyzed using the real-time polymerase chain reaction. Results: The significant increase in E2 in H295R cells exposed to AVO, HS, OS, OMC, and OC suggest an estrogenic effect of the tested UV-filters. A significant decrease in T was observed in cells exposed to HS and OS. EC₅₀ values for E2 increase were 105 nM for AVO, 110 nM for HS, 120 nM for OS, 55 nM for OMC, and 80 nM for OC. Both binary mixtures consisting of OMC+HS and OMC+OS have synergistic effects. Conclusions: Our results showed that five types of UV-filter substances increase E2 in H295R cells. We examined the mixture toxicity in terms of increased estrogenicity and confirmed that E2 significantly increased when OMC was mixed with a salicylate-based UV-filters. These findings highlight the importance of determining the impact of UV filter mixtures.

• 한국전기전자재료학회논문지
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• 제15권3호
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• pp.253-257
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• 2002

A new photoalignment material PNC, pole norbornene-2,3-dicarboxyolyl cholesterol, was synthesized and the electro-optical (EO) characteristics of the vortical-alignment (VA) liquid crystal display (LCD) photoaligned with UV exposure on the PNC surface were studied. EO characteristics of the photoaligned VA-LCD using a UV filter-less method was better than that of the UV filter method on the PNC surface for short UV exposure time. The response time of the photoaligned VA-LCD on the PNC surface without UV filter on the PNC surface is almost the same compared with the rubbing aligned VA-LCD.