• Journal of Dental Rehabilitation and Applied Science
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• v.39 no.4
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• pp.195-203
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• 2023

Purpose: This study aimed to evaluate the influence of surface sealants on the surface roughness of composite resins. Materials and Methods: The study used microfilled composite resin (Metafil CX, Sun Medical Co.) and hybrid composite resin (Aelite^TM LS posterior, Bisco). Sixty specimens (8 mm in diameter and 4 mm in height) of each composite resin type were prepared and divided into 3 groups. Each specimen was ground with 600, 1000, and 2000-grit sandpaper. The Surface roughness (Ra) values were measured using a surface roughness tester (SJ-301, Mytutoyo) before and after surface sealant application. Surface sealants, BisCover^TM LV (Bisco), Optiguard^® (Kerr), and Seal-n-Shine^TM (Pulpdent), were applied to the specimens, as instructed and observed by scanning electron microscope (JSM-7500, JEOL) and atomic force microscope (MultiMode IV, Veeco Instruments). Results: Specimens ground with 600-grit sandpaper coated with surface sealants exhibited significantly lower Ra values than the untreated group (P < 0.05). Specimens ground with 1000 and 2000-grit sandpaper showed statistically no difference. There was no significant difference in surface roughness among BisCover^TM LV, Optiguard^®, and Seal-n-Shine^TM. SEM and AFM revealed remarkably decreased microdefects on the surfaces of composite resins after surface sealant application. Conclusion: Surface sealants can influence surface roughness when applied on the rough surface of composite resins but not on highly polished composite resins.

• Journal of Power System Engineering
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• v.7 no.1
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• pp.25-33
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• 2003

섬유강화 복합재료의 계면 강도는 강화재와 메트릭스간의 계면특성, 강화용 섬유의 표면처리 및 섬유간의 거리 등에 많은 영향을 받는다. 본 연구에서는 섬유간의 거리가 섬유강화 복합재료의 계면특성에 미치는 영향을 고찰하기 위해, E glass fiber/epoxy 복합재료의 시험편을 제작하고, 섬유의 표면처리 및 섬유파괴가 이웃하는 섬유파괴에 영향을 미치는 거리에 대해 고찰하였다. E glass fiber/epoxy 복합재료의 계면 전단강도는 섬유간 거리 $0{\sim}50{\mu}m$ 사이에서는 섬유의 표면처리와는 관계없이 섬유간 거리가 증가할수록 증가하였고, 섬유간 거리 $50{\mu}m$ 이상에서는 섬유간거리에 관계없이 계면전단강도는 일정하였다.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.38 no.2
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• pp.311-317
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• 2018

The new asphalt surface reinforcement method (ASRM) is one of the preventive maintenance methods in asphalt concrete pavements. The adhesion performance of new ASRM satisfied the standard of non-slip pavement and bridge waterproofing materials. As a results of durability tests (as wheel load, rolling bottle and UV resistance test), the new ASRM showed sufficient resistance to traffic and environmental loads. The waterproof and chemical resistance tests of new ASRM were conducted to evaluate whether the pavement could be protected from water and chemicals and the performances of new ASRM were satisfactory. Furthermore, the new ASRM demonstrated some rejuvenation effects due to its toughness increases in recycled asphalt concrete mixture by 5% compared to the conventional hot mix asphalt mixture using reclaimed asphalt pavement. In conclusion, the new ASRM was evaluated to protect the asphalt concrete pavement and increase the lifetime.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.2
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• pp.389-395
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• 2017

A study was carried out to improve the field implementation of asphalt surface reinforcement method which is a preventive maintenance. Mean Texture Depth (MTD) was measured to quantify the surface condition and used to determine the optimum application rate. Determining the application rate using MTD can reduce the material loss from 30% to 15%. In order to reduce the curing time to 30 minutes, the heat capacity of $317kcal/m^2$ is required. Therefore, the design capacity of the heating curing device requires more than 380,000 kcal/hr. The asphalt surface reinforcement method is preferably applied at a time when slight cracking occurs before the permanent deformation becomes serious. Through the analysis of the pavement survey data, it was decided to apply the surface reinforcement method at the crack rate of 3~4%. Heating the surface reinforcement agent to $50^{\circ}C$ improves workability and ensures sufficient penetration depth even at a crack width of 1 mm. The results will be utilized as basic data for the development of automated construction equipment for efficiency improvement.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.302-302
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• 2013

본 연구는 이온질화시 self-sputtering에 의한 AISI D2 소재의 표면경화에 대한 연구를 진행하였다. 이를 위해 이온질화시 질소가스와 아르곤 가스를 이용해 이온질화를 수행하였다. 이에 대한 결과는 optical micrograph (OM), scanning electron microscopy (SEM), X-ray diffraction(XRD), transmission electron microscopy (TEM)를 이용해 분석하였다. 실험결과, 소재의 경도는 570 HV에서 약 1470 HV까지 상승하였다. 극표면에 CrN-enriched layer의 형성 및 극표면 아래층에서 질소의 과포된 화합물층을 관찰할 수 있었다. 표면경화는, 극표면에 CrN-enriched layer의 형성과, 아래 N의 과포화에 의한 ${\gamma}$?autenite) phase, 그리고 diffusion layer의 형성에 의한 multi-layer의 형성으로 표면에 강화에 기여한것으로 사료된다.

• Analytical Science and Technology
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• v.8 no.3
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• pp.313-319
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• 1995

Surface-enhanced Raman scattering(SERS) spectroscopy was employed to analyze the genotoxic nucleobase adducts of benzo[a]pyrene(BP) formed through one-electron oxidation pathway. SERS spectroscopy provided sufficient resolution to distinguish if BP intermediate was bound to different nucleobases(e. g. adenine or guanine). Furthermore, SERS specroscopy was also able to detect the difference in the binding position of the adduct to the various sites of the nucleobase. The linearity of the calibration curve for N7Ade-BP ranged from 20 picogram to 800 nanogram per microliter and the detection limit under the current conditions was determined 20 picogram per microliter in a solution volume of 20 microliter.

• Korean Journal of Optics and Photonics
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• v.24 no.1
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• pp.39-44
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• 2013

In this study, we assessed the hydrophilic characteristics of the surface of toughened glass used in smartphones by investigating the optical properties and contact angle characteristics of the plasma device. In this study, the characteristics were different depending on the partial pressure of the gas, input voltage, and degree of ionization of argon gas. In this study, the surface of the toughened glass became more hydrophilic, as indicated by contact angle and light spectrum, after plasma treatment than before the treatment.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.513-514
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• 2009

This study is to determine that lithium-silicate as reinforcement on surface for repairing concrete structure affects adhesive strength of mortar to recover the surface and of the strength for the obverse of concrete. these are focused on applying fields to the study.

• Proceedings of the Korean Fiber Society Conference
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• 2001.10a
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• pp.330-333
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• 2001

일반적으로 하나 또는 그 이상의 입자상 충전재 흑은 섬유상 강화재와 연속상인 고분자 기재로 이루어진 고분자 복합재료는 물성이나 기능이 더욱 더 우수한 고성능/고기능성 고분자 재료에 대한 수요가 급격히 증대됨에 따라 이에 대한 많은 연구가 행해지고 있다[1,2]. 그러나 고분자 복합재료의 응력전달은 강화재와 고분자 기재의 계면을 통하여 일어나게 되므로 복합재료의 기계적 물성 등은 충전재의 양, 입자의 크기, 표면성질 뿐만 아니라 강화재와 고분자 기재 사이의 계면 접착력 또는 계면 성질에 크게 좌우된다. (중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2007.11a
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• pp.29-29
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• 2007

본 연구에서는 분산강화 스테인리스강을 이용하여 케비테이션 발생 시 고체입자충격에 의한 재료의 침식메커니즘 및 침식저항성을 고찰하고자 하였다. 케비테이션 시간에 따른 침식저항성 측정결과, 기존재료에 비해 분산강화된 시편의 무게손실량이 낮았으며 침식잠복기가 짧고 침식속도가 낮아 전반적으로 우수한 저항성을 보였다. 이것은 침식표면의 손상메커니즘 관찰을 통해 확인할 수 있었다.