• Journal of the Korean Vacuum Society
• /
• v.21 no.1
• /
• pp.6-11
• /
• 2012

In order to understand a process of contaminants removal on surface of Cu seed layer (Cu seed/Ti/Si) by sputter deposition, we investigated the changed morphology and states of Cu seed surface after pretreatment in alkali degreasing Metex TS-40A solution according to dipping time. After TS-40A pretreatment, the surface morphology with clearer grains was observed by Field emission scanning electron microscope and the changed surface chemical states and impurities on surface of samples were checked by X-ray photoelectron spectroscopy. Dipping time in TS-40A solution had very little effect on surface of Cu seed layer. After pretreatment, much carbons and little oxygens on surface of Cu seed were eliminated and the decrease of peaks corresponded to O=C and $Cu(OH)_2$ was estimated. However, Si content (=silicate) was detected on sample surface. We think that the silicate impurity forms on Cu seed by chemical reaction of TS-40A solution included silicate component. By pretreatment of alkali degreasing Metex TS-40A solution, it showed an excellent effect in removal of O=C and $Cu(OH)_2$ on Cu seed layer, but the silicate was formed on surface of Cu seed. Therefore, another cleaning process such as acid cleaning is required for removal of this silicate in use of this alkali degreasing.

• Journal of the Korean Geosynthetics Society
• /
• v.18 no.1
• /
• pp.79-89
• /
• 2019

The field measurement and laboratory experiment were conducted to investigate the effect of reducing the surface temperature of the functional aspect of the heat island phenomenon of the permeable block which is made the recycled synthetic resin rather than the existing concrete permeable block. Field measurement was taken for 3 days in consideration of dry condition and wet condition and laboratory experiment was divided into dry condition, rainfall simulating condition, and wetting condition. The variations of temperature and the evaporation rate of water moisture content after experiment were confirmed. As a result of field measurement, it is confirmed that the surface temperature decreases due to the difference in albedo of the pore block surface rather than the cooling effect due to the latent heat of vaporization. The evaporation of moisture in a dry state where drought persisted or a certain level of moisture was not maintained in the surface layer. As a result of laboratory experiment, resin permeable block gives higher surface temperature when it is dry condition than concrete permeable block, but the evaporation of water in the pore is kept constant by capillary force in rainfall simulation condition, and higher temperature reduction rate. As a result of measuring the evaporation rate after laboratory experiment, it is confirmed that the effect of reducing temperature is increased as the evaporation rate of water is higher. Based on these results, correlation formula for evaporation rate and temperature reduction rate is derived.

• Journal of the Korean Applied Science and Technology
• /
• v.34 no.1
• /
• pp.152-162
• /
• 2017

A hydrophilic coating solution was prepared by adding a silane coupling agent and a nano-inorganic oxide in aqueous surfactant solution to increase the efficiency of photovoltaic power generation due to the introduction of antifogging and antifouling properties on the glass surface of the solar cell module. Addition of $Ludox^{(R)}$, a nano-inorganic oxide, to 1% hydrophilic coating solution showed improved hydrophilicity and excellent antifogging effect regardless of $Ludox^{(R)}$ concentration. However, the antifouling effect on the glass surface was showed only when Ludox was added more than 10%. In the case of addition of 0.7% of hydrolyzed TEOS at pH 4, the antifogging effect was maintained as a result of the steam test as well as the antifouling effect even after the coated glass surface was rubbed 100 times with a wet Kimwipe. In addition, from the surface roughness ($R_q$) calculated using AFM data, the higher surface roughness with irregular surface shape was obtained with the higher concentration of TEOS. The addition of 0.7% of TEOS showed relatively high surface roughness and well organized surface condition which can help to improve transmittance of light. In conclusion, $Ludox^{(R)}$ is not required only for the antifogging property. However, at least 10% of Ludox should be added to show antifouling effect and 0.7% of TEOS should be added for good durability.

• Proceedings of the Computational Structural Engineering Institute Conference
• /
• 2009.04a
• /
• pp.247-250
• /
• 2009

본 연구에서는 반복하중을 받는 구리 나노와이어에서 나타나는 초탄성 거동을 분자동역학 전산모사를 통해 해석하였다. 나노스케일에서는 표면적 대 부피비가 매우 크기 때문에 표면효과가 지배적으로 나타난다. 이로 인해 벌크상태에서는 보이지 않던 새로운 성질들이 나노크기에서 나타나는데, 이러한 효과로 인해 나노와이어의 경우에는 초탄성 거동을 보인다. 초탄성 거동은 나노와이어의 결정학적 방향의 재배열에 의한 것으로써, 하중을 받는 동안 나노와이어의 결정 구조는 변하지 않으며, 쌍정의 발생 및 쌍정계면의 전파에 의해 결정학적 방향이 재배열된다. 재배열에 의해 부분적으로 변형되었던 나노와이어는 하중을 제거하거나 하중의 방향이 바뀜에 따라 원래의 상태를 회복하는 거동을 보이게 된다. 본 연구에서는 분자 동역학 전산 모사를 통해 <100>/{100} 구리 나노와이어가 반복적인 압축-인장 거동 하에서 초탄성을 보이게 됨을 확인하였으며, 반복 하중 싸이클을 증가시키는 전산모사를 통해 나노와이어의 초탄성이 영구적으로 유지됨을 확인하였다.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.15 no.8
• /
• pp.4930-4941
• /
• 2014

This study had three purposes. First, the effects of job-related affective states on emotional labor (deep acting and surface acting) of employees engaging in service job were examined. Second, previous studies focused on the negative effects of emotional labor on job attitudes. On the other hand, this study dealt with not only the negative effects of emotional labor but also its positive effects. In particular, this study examined the effects of emotional labor on positive job attitudes, such as job commitment and job involvement, as well as negative job attitudes, such as exhaustion and cynicism. Finally, this study examined the mediation effect of emotional labor on the relationship between the job-related affective state and job attitudes. The data was collected from 150 employees working in 15 service firms in Korea. The results were as follows. First, the positive job-related affective state increased the deep-acting. On the other hand, negative job-related affective state increased surface-acting. Second, the main effect of deep-acting on positive job attitudes (dedication and vigor) was significant. In addition, the main effects of surface-acting on the negative job attitudes (exhaustion and cynicism) was significant. Finally, the mediating effect of deep-acting on the relationship between positive job-related affective state and positive job attitudes was significant. In addition, surface-acting mediated the relationship between negative job-related affective state and negative job attitudes. The theoretical and practical implications of this study are provided in the discussion session.

• Applied Microscopy
• /
• v.42 no.2
• /
• pp.95-103
• /
• 2012

The cell surface sculpture of the plant epidermis has received great interest recently. It has also been an active area of research, as the biological microstructures of the surface, such as papillae and waxes, exhibit several unique properties, including self-cleaning character; namely the "Lotus effect" first described in the leaves of the lotus, Nelumbo nucifera. The Lotus effect is the phenomenon in which the super-hydrophobic and water-repellent nature of lotus leaves allow water drops to run off easily on the surface in a rolling and sliding motion thereby facilitating the removal of dirt particles. It is well-known that surface roughness on the micro- and nanoscale is a primary characteristic allowing for the Lotus effect. This effect is common among plants and is of great technological importance, since it can be applied industrially in numerous fields. In the present study, Nelumbo nucifera leaf and stem epidermal surfaces have been examined with a focus on the features of papillae and wax crystalloids. Both young and mature Nelumbo nucifera leaf epidermis demonstrated the Lotus effect on their entire epidermal surface. The central area of the upper epidermis, in particular, formed extremely papillose surfaces, with an additional wax layer, enabling greater water repellency. Despite the presence of wax crystalloids, epidermal surfaces of the lower leaf and stem lacking papillae, were much more easily wetted.

• Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
• /
• 2003.04a
• /
• pp.133.2-134
• /
• 2003

감(Diospyros kaki)은 한국과 일본이 주산지이며 국내 단감의 재배 품종은 만생종인 ‘부 유’가 주종을 이루고 있으며 독특한 맛, vitamin C 등 영양적 가치와 함께 식품으로서 안전성이 우수한 과실로 평가되면서 소비량이 매년 꾸준히 증가하고 있다. 단감은 국내에서 생산되는 과실로서는 드물게 PE필름에 포장된 상태에서 유통되고 있다. 이렇게 포장된 과실은 저온상태에서 유통되어야 MA의 효과를 충분히 발휘할 수 있으며 유통기한도 연장될 수 있을 것으로 생각되나 현재 국내에서 저온 유통되는 단감은 찾아보기 어렵다. 이에 현행 상온유통에서 PE필름 밀봉 방식과 무포장 상태의 과실의 품질변화를 살펴봄으로써 그 문제점을 파악하고 반응표면분석을 통하여 최적 저장조건을 찾아내고자 하였으며 유통조건을 고려하여 0.05mm LDPE 필름밀봉방식의 품질변화를 보았으며, 문제점을 파악하고자 하였다. 본 연구에서는 LDPE 필름포장이 단감의 품질변화에 미치는 영향을 알아보기 위하여 단감은 2$0^{\circ}C$에서 0.05mm LDPE필름으로 포장하여, 당도, 수소이온농도, 경도를 측정하고 또한 $O_2$(1, 3, 5%) $CO_2$(5, 10, 15%)의 9구분으로 환경기체조성을 조절하여 중심합성계획법에 의해 반응표면분석을 하고 종합적으로 검토하였다.

• Journal of the Korean Magnetics Society
• /
• v.25 no.6
• /
• pp.175-179
• /
• 2015

The half-metallicity and magnetism of the (001) surfaces of $(AlP)_1/(CrP)_1$ superlattice were investigated by means of FLAPW (Full-potential Liniarized Augmented Plane Wave) method. We considered four types of (001) surface termination, i.e., Al(S)-, Cr(S)-, P(S)Al(S-1)- and P(S)Cr(S-1)-term systems. We found that only Cr(S)-term system maintains the half-metallicity at the surface as only this system has the calculated magnetic moment of integer number of bohr magnetons. The magnetic moment of Cr(S) atom in the system was $3.02{\mu}_B$ which was increased from the bulk value by the effects of band narrowing and increased spin-splitting at the surface. The electronic density of states of the P(S) atom in the P(S)Al(S-1)-term showed very sharp surface states due to the broken $p_z$ bonds at the surface. We found there is still a strong p-d hybridization between the P(S) and Cr(S-1) layers in the P(S)Cr(S-1)-term which causes a considerable increase of magnetic moment of P(S) atom.

• Journal of the Korean Ceramic Society
• /
• v.38 no.7
• /
• pp.608-614
• /
• 2001

수지결합질 탄소재의 사출성형시 중요한 요소는 열유변학적 거동이다. 수지결합질 탄소재의 열유변성, 기계적 물성은 충진제(흑연)의 표면상태에 영향을 받는다. Coupling 처리에 의한 충진제의 표면개질은 binder와의 젖음성과 호환성 등에 영향을 미쳐 수지결합질 탄소재의 특성을 향상시킨다. 본 연구에서는 충진제의 표면개질을 위해 실란 coupling 처리하였다. 충진제의 표면에 코팅된 실라놀은 FT-IR과 침수거동 관찰결과 충진제 표면에 단층으로 코팅되었음을 보였다. Coupling 처리는 충진제 표면에 활성을 가함으로써 수지결합질 탄소재의 열유변학적 거동과 기계적 물성에 기여하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
• /
• 2014.11a
• /
• pp.298-298
• /
• 2014

표면 텍스처링 기술은 서로 접촉되는 표면 형태에 발생하는 마찰을 줄이는 기술이다. 이 기술은 자동차와 같은 기계장치에서 마찰을 줄여 보다 좋은 에너지 효율을 얻을 수 있어 효과가 기대되는 기술이다. 본 연구는 고체윤활제($CaF_2$ or $BaF_2$)와 alumina, zriconia를 이용하여 자기 윤활 세라믹 복합체를 만들고 그 위에 표면 텍스처링 후, 윤활 상태에서의 마찰특성을 알아보았다.