• 한국건설순환자원학회논문집
• /
• 제5권1호
• /
• pp.53-58
• /
• 2017

FRP Hybrid Bar는 내부에 강재를 유리섬유와 에폭시 수지가 코팅된 형태로 사용되는데, 인장경화 성능이 있으며, 경량이므로 효과적인 보강재료로 사용될 수 있다. 자외선 및 동결융해에 노출된 에폭시는 표면 열화가 발생하기 쉬우며, 이는 매립된 철근 및 표면의 콘크리트와의 부착력 저하를 야기할 수 있다. 본 연구에서는 일반철근, FRP Hybrid Bar 및 자외선(UV) 폭로시험을 거친 FRP Hybrid Bar의 외관특성분석을 실시하였다. 또한 각 보강재를 사용하여 콘크리트 인발 공시체를 제조하였으며, 동결융해시험을 실시해 Cycle에 따른 부착성능을 분석하였다. FRP Hybrid Bar는 UV 폭로시험 후에도 표면 산화(Chalking)와 같은 에폭시계 재료의 열화가 나타나지 않았다. 동결융해시험은 120Cycle 및 180Cycle까지 진행하였는데, UV 폭로시험 후 FRP Hybrid Bar를 사용한 공시체는 $241{\pm}kN$ 부착력을 가지고 있었다. 이는 일반철근 대비 약 106.3%수준으로 개선된 부착강도인데, FRP Hybrid Bar 표면의 규사코팅에 따라 부착면적이 증가했기 때문이다. 3가지 조건(일반철근, FRP Hybrid Bar, UV 폭로시험 후의 FRP Hybrid Bar)에 대하여, 동결융해 Cycle이 증가함에 따라 부착력이 크게 감소하지는 않았으나, 코팅된 규사의 박락으로 인해 UV 시험 이후의 동결융해를 거친 조건에서는 실험 편차가 상대적으로 증가하였다.

• 한국건설순환자원학회논문집
• /
• 제5권2호
• /
• pp.130-136
• /
• 2017

본 연구에서는 UV 폭로 및 동결융해 환경이 FRP Hybrid Bar의 인장거동 및 표면 열화에 미치는 영향을 평가하기 위해 FRP Hybrid Bar를 대상으로 UV 폭로 및 동결융해 시험을 실시하였다. FRP Hybrid Bar의 경우 UV 폭로 및 동결융해 180cycle 시험 전/후 외관적인 열화가 거의 발생하지 않았다. 또한 FRP Hybrid Bar의 주요 장점 중 하나인 인장경화특성은 동결융해 시험을 거친 이후에도 유지되었는데, 이는 UV 폭로시험을 거친 FRP Hybrid Bar에도 유효하게 평가되었다. UV 폭로시험을 거친 FRP Hybrid Bar는 일반 FRP Hybrid Bar와 거의 비슷한 인장거동을 나타내었으며, 동결융해 180cycle의 진행에도 불구하고 일반철근, FRP Hybrid Bar, UV 폭로를 거친 FRP Hybrid Bar의 인장거동은 큰 변화를 나타내지 않았다. 본 연구에서는 UV 폭로 및 동결융해 환경이 FRP Hybrid Bar의 외관 및 인장 특성에 큰 영향을 미치지 못하는 것으로 판단되지만, 충격에 따른 규사코팅의 박락은 콘크리트와의 부착력에 영향을 미치므로 이에 대한 고려가 필요하다.

• 한국정보통신학회:학술대회논문집
• /
• 한국정보통신학회 2021년도 춘계학술대회
• /
• pp.567-568
• /
• 2021

본 논문에서는 UV-A와 UV-C를 포함하는 복합 파장의 LED 모듈을 적용한 캐빈 필터를 설계 및 제작하고 성능를 시험하였다. 제작한 캐빈 필터의 세균 및 공팜이 살균 시험에서 살균 능력을 확인하였고 유기화합물 분해 시험에서는 특수 챔버를 제작하여 유기물 분해 능력을 검증하였다. 광촉매로 콜케이트를 사용하는 것이 매탈매쉬를 사용하는 것보다 우수한 성능을 확인하였다. 본 연구를 통해서 제작한 캐빈 필터의 살균 및 공기 정화 능력을 실제와 유사한 환경 시험을 통해서 확인하였다.

• 방사선산업학회지
• /
• 제4권1호
• /
• pp.39-45
• /
• 2010

The pollution of antibiotics is a major cause of spreading antibiotics resistant bacteria in the environment. Applications of ozonation, UV, and ${\gamma}-ray$ irradiations have been introduced to remove antibiotics in the effluents from wastewater treatment system. In this study, we compared the chemical (HPLC) and biological (antimicrobial susceptibility test, AMS) assays in measuring of the concentrations of residual antibiotics after ${\gamma}-ray$ and UV irradiation. Most samples were degraded by ${\gamma}-ray$ irradiation (1~2 kGy). However, lincomycin and tetracycline were not degraded by UV irradiation. The concentration of residual antibiotics, that was treated with ${\gamma}-ray$ and UV irradiation, measuring by bioassay was similar to HPLC. The concentrations of ${\gamma}-ray$ irradiated cephradine measured by AMS test were 2 times higher than that of HPLC assay, indicating AMS test is more sensitive than HPLC assay. These results indicate that ${\gamma}-ray$ irradiation technique is more useful than UV irradiation, and biological assay is more useful to detect the antibiotics and toxic intermediates in antibiotics degradation.

• 전기학회논문지
• /
• 제62권5호
• /
• pp.643-648
• /
• 2013

In this study, degradation was observed by irradiating UV rays to the polymer insulators which have been widely used in outdoor electric power facilities. For an indoor accelerated UV test, 0.55 w/m2 of UV rays were applied using a xenon-arc method. A UV detection system with 65 ${\phi}mm$ in diameter, 100 mm in length and 1.0 of brightness (F/#) has been designed. Even though efflorescence on the surface of polymer insulators wasn't observed according to the accelerated UV test. UV rays were detected at around 50% and 40% of insulation breakdown in EPDM and silicone-type insulators respectively. As degradation continued because of an indoor accelerated UV test, breakdown voltage with which UV rays can be detected in an early stage decreased as well. A silicone polymer insulator would be severer than EPDM polymer insulator in terms of surface degradation because of UV strength against $V_m/V_{BD}$ was high in silicone polymer insulators. UV strength in silicone-type insulators increased at 1,000 $kJ/m^2$ because contact angle at the intial stage sharply decreased to from $113^{\circ}$ to $92.1^{\circ}$.

• 한국기계가공학회지
• /
• 제17권5호
• /
• pp.8-15
• /
• 2018

Films with special properties (e.g., water-repellent films, optical films, anti-reflection films, and flexible films) are referred to as functional films. Recently, there has been interest in fine patterning methods for film fabrication. In particular there have been many studies that use a UV nanoimprint process involving a UV curing method. In this paper, a polymer film was fabricated by the UV nanoimprint process with a micro-pattern, and its durability was evaluated by a wear test and a nano-indentation test. The film mechanical properties (such as coefficient of friction, hardness, and modulus of elasticity) were measured. Moreover, the choice of PUA type resin used in the UV nanoimprint process was confirmed to impact the durability of the thin film. Despite making the polymer film samples using the same method and PUA type resin, different coefficient of friction, hardness, and modulus of elasticity values were obtained. PUA 4 resin had the most favorable coefficient of friction, hardness, and modulus of elasticity. This material is predicted to produce a high durability functional film.

• The Journal of Advanced Prosthodontics
• /
• 제3권2호
• /
• pp.63-68
• /
• 2011

PURPOSE. The object of this study was to investigate the effect of UV irradiation (by a general commercial UV sterilizer) on anodized titanium surface. Surface characteristics and cellular responses were compared between anodized titanium discs and UV irradiated anodized titanium discs. MATERIALS AND METHODS. Titanium discs were anodized and divided into the following groups: Group 1, anodized (control), and Goup 2, anodized and UV irradiated for 24 hours. The surface characteristics including contact angle, roughness, phase of oxide layer, and chemical elemental composition were inspected. The osteoblast-like human osteogenic sarcoma (HOS) cells were cultured on control and test group discs. Initial cellular attachment, MTS-based cell proliferation assay, and ALP synthesis level were compared between the two groups for the evaluation of cellular response. RESULTS. After UV irradiation, the contact angle decreased significantly (P<.001). The surface roughness and phase of oxide layer did not show definite changes, but carbon showed a considerable decrease after UV irradiation. Initial cell attachment was increased in test group (P=.004). Cells cultured on test group samples proliferated more actively (P=.009 at day 2, 5, and 7) and the ALP synthesis also increased in cells cultured on the test group (P=.016 at day 3, P=.009 at day 7 and 14). CONCLUSION. UV irradiation induced enhanced wettability, and increased initial cellular responses of HOS cells on anodized titanium surface.

• 한국식품위생안전성학회지
• /
• 제9권1호
• /
• pp.15-21
• /
• 1994

The mutagenic activity of four phenothiazine derivatives such as chlorpromazine, perphenazine, trifluoperazine and thioridazine in conjunction with UV-A irradiation or not based on the Ames plate incorporation test in the presence and absence of liver microsomal enzyme(S9 fraction). None of these compounds and their photo-excited were detected as mutagen in the Salmonella microsome assay with TA 98 and TA 100.

• Corrosion Science and Technology
• /
• 제9권6호
• /
• pp.265-269
• /
• 2010

This paper describes the exfoliation and surface modification of muscovite mica for UV coating formulation. For the exfoliation of the mica, hydrothermal process was used in the presence of lithium nitrate ($LiNO_3$). After the cation exchange with $Li^+$ ions, the surface of the mica was modified with several amphiphilic substances to increase compatibility and storage stability in UV coating formulation. Such a hydrophobic surface modification affected colloidal stability as well as dispersibility of the exfoliated mica in UV coating solution. Anticorrosive property of mica/UV coated steel plates was tested by salt spray test (SST) and compared with sodium montmorillonite ($Na^+$-MMT)/UV coated steel plates.

• 패션비즈니스
• /
• 제11권3호
• /
• pp.59-68
• /
• 2007

This study examined knowledge and hair care behaviors of hair and scalp on UV(ultraviolet) comparing beauty care major and non-major female students. Results were obtained by questionnaire in 159 students majoring in beauty care and 198 students not majoring, was used frequency analysis, varimax rotation, t-test, F-test, Tukey post test. The analysis was statistically processed by using SPSS 12.0 program. The knowledge of hair and scalp on UV associated with a major showed significant on hair damage, in the UV, hair, scalp, hair damage, and UV and hair-related items, suggesting higher level in major female students. The results of care behaviors of UV and hair and scalp knowledge associated with a major. Correlation of care behaviors with a major showed significant results. For correlation by subfactor, there was significant difference in self-care, habitual care, and washing care between two groups, but there was no significant difference in protection care. It was found that both major and non-major students did not receive professional care.