• 한국산학기술학회논문지
• /
• 제21권9호
• /
• pp.487-497
• /
• 2020

본 연구는 미용적인 피부 관리를 위해 대표적으로 사용되는 다양한 필링중 화학적인 필링과 물리적인 필링이 여성들의 피부 개선에 미치는 효과와 장단점을 확인하여 대상자의 피부상태에 따른 올바른 적용법을 알아보고자 하였다. 연구를 위하여 2011년 11월 1일부터 12월 27일까지 복합성 피부를 가진 여성 20명을 대상으로 조사를 실시하였고, 이 중 10명은 화학적 필링 군으로, 10명은 물리적 필링 군으로 나누었다. 실험은 6주 동안 주 1회 총 6회를 진행 하였고, 시술시 마다 피부측정기를 이용해 수분과 유분, 각질, 모공, 주름, 색소에 대해 측정하였다. 실험결과 화학적 필링군의 경우 글리콜산 필링과 젖산 필링 모두 보습에 효과적으로 나타났다. 물리적 필링군의 경우 크리스탈 필링은 주름에 더 효과적이었고, 다이아몬드 필링은 각질과 색소개선에 더 효과적이었다. 매체에 따른 필링의 효과를 비교해 본 결과 더 많은 항목에서 물리적 필링이 더 효과적으로 나타났으나, 수분과 유분의 변화는 화학적 필링이 더 효과적인 것으로 나타났다. 결론적으로 두 집단 간에 시행했던 필링의 효과가 큰 차이가 나지 않는다면 시술 시 자극이 적고 만족도가 높은 필링 시술을 받는 것이 효과적인 피부 관리법 이라고 볼 수 있을 것이다.

• 열처리공학회지
• /
• 제33권3호
• /
• pp.124-128
• /
• 2020

Recently, many studies on growth of single crystal diamond using MPECVD have been conducted. The heteroepitaxial method is one of the methods for growing diamonds on a large-area substrate, and research on synthesis of single crystal diamonds using SrTiO₃, MgO, and sapphire substrates has been attempted. In addition, research is being conducted to reduce the internal stress generated during diamond growth and to improve the crystallinity of the diamond. The compressive stress generated therein causes peeling and bowing from the substrate. This study aimed to synthesize heteroepitaxial single crystal diamonds with high crystallinity by surface modification. A diamond thin film was first grown on a sapphire/Ir substrate by MPECVD, and then etched with H₂ gas to modified the morphology and roughness of the surface. A secondary diamond layer was grown on the surface, and the internal stress, crystallinity of the diamond were investigated. As a result, the fabrication of single crystal diamonds with improved crystallinity was confirmed.

• 한국기계가공학회지
• /
• 제15권6호
• /
• pp.9-15
• /
• 2016

Due to material-specific vulnerabilities, the surfaces of the liquid crystal glasses used in mobile phones can crack easily, with even the smallest cracks undergoing propagation. To protect the glass surfaces, films are attached to the surfaces during the mobile phone production process. However, after machining the liquid crystal, removal of the film on the liquid crystal surface using chemical and mechanical methods is required. In this research, a peeling apparatus was developed for removing the films attached to liquid crystal surfaces during the production process. Mechanical attachment and design automation through experimentation and finite element modelling were performed to confirm the validity of the design.

• 한국표면공학회지
• /
• 제13권4호
• /
• pp.211-220
• /
• 1980

Internal stress of electrodeposited metals affect physical and mechanical characteristics of deposits. Internal stress of nickel deposits was reviewed intensively. Important outcomes are as follows. Substrate have an important effect on internal stress of electrodeposit. Origin of its internal stress could be explained mismatch of crystal lattice and coalescence of crystallites. When surface cleaning is not satisfying, instantaneous stress is low but the electrodeposited layer being thickened increasingly stress become to high and peeling phenomenon occurs. Effect of current density and temperature on internal stress is variable. Internal stress increases rapidly at pH 5 and above because of codepositing colloidal materials caused hydrolysis. Concentrations of nickel ion and $H_3BO_3$ ion affect little on internal stress and solution which contains impurities tend to increase stress. Especially impurities of $H_2O_2$ and iron ion have a great effect on internal stress. Additives are divided in two kind. One is increasing tensile stress another is increasing compressive stress. Concentrations of additives have a great effect on internal stress.

• Journal of Pharmaceutical Investigation
• /
• 제32권2호
• /
• pp.107-112
• /
• 2002

To investigate the feasibility of developing a novel melatonin plaster, the effects of vehicles and drug loading dose on the in vitro permeation of melatonin across dorsal hairless mouse skin from pressure-sensitive adhesive (PSA) matrices were examined. Vehicles employed were propylene glycol laurate (PGL), propylene glycol monocaprylate (PGMC) and diethylene glycol monoethyl ether (DGME). Among PSAs used, only $Duro-Tak^{\circledR}$ 87-2196 showed a good peeling property. The release from $Duro-Tak^{circledR}$ 87-2196 was proportional to the square root of time, and dose-dependent. The fluxes increased as the loading dose increased over the doses under solubility. The relatively high permeation flux $(3.03{\pm}1.37\;{\mu}g/cm^2/hr)$ was obtained when using PGMC at the melatonin loading dose of $45\;mg/140\;cm^2$. Lag time was not affected by the vehicles used but by the thickness spread. The melatonin plasters prepared using PGMC showed a good adhesive property onto skin, and showed no crystal formation.

• 보존과학회지
• /
• 제33권6호
• /
• pp.431-442
• /
• 2017

본 연구는 양산 통도사 괘불탱의 손상 및 채색 상태 유형에 대한 자료를 확보하고, 비파괴 방법과 박락된 시편의 교차분석을 통한 채색 안료의 종류를 밝혀내고자 하였다. 괘불탱의 손상 유형을 확인한 결과, 꺾임과 접힘, 들뜸, 결실, 박락 등이 관찰되었다. 채색 안료 분석 결과, 적색 계열의 안료는 연단과 진사, 유기 안료가 사용되었고, 녹색 안료는 공작석과 염화동(녹염동광)을 사용하였으며, 청색 안료는 석청과 군청, 백색 안료는 연백과 활석을 혼합하여 사용하였다. 또한, 황색 안료는 연백과 유기 안료를 혼합하여 사용하거나 연백 위에 유기 안료를 덧칠하였으며, 흑색 안료는 먹을 사용 했을 것으로 추정된다. 박락된 시료를 수습하여 안료의 입자상태 분석을 통해 녹색안료의 결정형을 쉽게 구분할 수 있었으며, 진한청색과 연한청색도 마찬가지로 입자의 크기나 형태가 원료의 상이함에 따라 서로 다름을 확인하였다. 또한, 황색과 자색은 입자감이 없는 유기안료를 사용하였으며, 특이하게 어두운 적색은 주황색과 먹을 혼합하여 사용한 것으로 확인되었다.

• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2012년도 제42회 동계 정기 학술대회 초록집
• /
• pp.478-478
• /
• 2012

Recently, there are many researches in order to increase the deposition rate (D/R) and improve film uniformity and quality in the deposition of microcrystalline silicon thin film. These two factors are the most important issues in the fabrication of the thin film solar cell, and for the purpose of that, several process conditions, including the large area electrode (more than 1.1 X 1.3 (m2)), higher pressure (1 ~ 10 (Torr)), and very high frequency regime (VHF, 40 ~ 100 (MHz)), have been needed. But, in the case of large-area capacitively coupled discharges (CCP) driven at frequencies higher than the usual RF (13.56 (MHz)) frequency, the standing wave and skin effects should be the critical problems for obtaining the good plasma uniformity, and the ion damage on the thin film layer due to the high voltage between the substrate and the bulk plasma might cause the defects which degrade the film quality. In this study, we will propose the new concept of the large-area multi-electrode (a new multi-electrode concept for the large-area plasma source), which consists of a series of electrodes and grounds arranged by turns. The experimental results with this new electrode showed the processing performances of high D/R (1 ~ 2 (nm/sec)), controllable crystallinity (~70% and controllable), and good uniformity (less than 10%) at the conditions of the relatively high frequency of 40 MHz in the large-area electrode of 280 X 540 mm2. And, we also observed the SEM images of the deposited thin film at the conditions of peeling, normal microcrystalline, and powder formation, and discussed the mechanisms of the crystal formation and voids generation in the film in order to try the enhancement of the film quality compared to the cases of normal VHF capacitive discharges. Also, we will discuss the relation between the processing parameters (including gap length between electrode and substrate, operating pressure) and the processing results (D/R and crystallinity) with the process condition map for ${\mu}c$-Si:H formation at a fixed input power and gas flow rate. Finally, we will discuss the potential of the multi-electrode of the 3.5G-class large-area plasma processing (650 X 550 (mm2) to the possibility of the expansion of the new electrode concept to 8G class large-area plasma processing and the additional issues in order to improve the process efficiency.