• Title/Summary/Keyword: Treatment barrier

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Study of the Carrier Injection Barrier by Tuning Graphene Electrode Work Function for Organic Light Emitting Diodes OLED (일함수 변화를 통한 그래핀 전극의 배리어 튜닝하기)

  • Kim, Ji-Hun;Maeng, Min-Jae;Hong, Jong-Am;Hwang, Ju-Hyeon;Choe, Hong-Gyu;Mun, Je-Hyeon;Lee, Jeong-Ik;Jeong, Dae-Yul;Choe, Seong-Yul;Park, Yong-Seop
    • Proceedings of the Korean Vacuum Society Conference
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    • 2015.08a
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    • pp.111.2-111.2
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    • 2015
  • Typical electrodes (metal or indium tin oxide (ITO)), which were used in conventional organic light emitting devices (OLEDs) structure, have transparency and conductivity, but, it is not suitable as the electrode of the flexible OLEDs (f-OLEDs) due to its brittle property. Although Graphene is the most well-known alternative material for conventional electrode because of present electrode properties as well as flexibility, its carrier injection barrier is comparatively high to use as electrode. In this work, we performed plasma treatment on the graphene surface and alkali metal doping in the organic materials to study for its possibility as anode and cathode, respectively. By using Ultraviolet Photoemission Spectroscopy (UPS), we investigated the interfaces of modified graphene. The plasma treatment is generated by various gas types such as O2 and Ar, to increase the work function of the graphene film. Also, for co-deposition of organic film to do alkali metal doping, we used three different organic materials which are BMPYPB (1,3-Bis(3,5-di-pyrid-3-yl-phenyl)benzene), TMPYPB (1,3,5-Tri[(3-pyridyl)-phen-3-yl]benzene), and 3TPYMB (Tris(2,4,6-trimethyl-3-(pyridin-3-yl)phenyl)borane)). They are well known for ETL materials in OLEDs. From these results, we found that graphene work function can be tuned to overcome the weakness of graphene induced carrier injection barrier, when the interface was treated with plasma (alkali metal) through the value of hole (electron) injection barrier is reduced about 1 eV.

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The effects of the Hominis placenta on skin barrier (태반이 피부장벽에 미치는 영향)

  • Nam, Hae-Jung;Park, Owe-Suk;Kim, Hee-Jeong;Kim, Keoo-Seok;Cha, Jae-Hoon;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.2
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    • pp.99-107
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    • 2006
  • Objectives : This experimental study was performed to investigate the effects of the Hominis placenta extracts on skin barrier. Methods : Male hairless mice, average weight 20g, were divided into two groups, intact and treatment group(paired, n=15). Intact group was not applied YB-301(an ointment including Hominis placenta). Treatment group was applied YB-301(an ointment including Hominis placenta) two times a day for 8 days. We observed skin melanin, skin erythema, skin pH, skin humidity, transepidermal water loss. Statistical analysis was performed by using paired sample T-test. Statistical significance was achieved if the probability was less than 5%(p<0.05) or 1%(p <0.01) Results : 1. YB-301(an ointment including Hominis placenta) showed statistically significant effect on skin melamin, skin pH, skin humidity(p<0.05). 2. YB-301(an ointment including Hominis placenta) showed statistically significant inhibitory effect on transepidermal water loss(p<0.01). 3. YB-301(an ointment including Hominis placenta) showed statistically no significant effect on skin erythema(p<0.05). conclusions : YB-301(an ointment including Hominis placenta) was effective m skin melanin, skin pH, skin humidity, transepidermal water loss in our study, so we suggest that Hominis placenta can be used as a ointment ingredient for strengthening the function of skin barrier.

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THE SYNTHESIS, PHYSICAL PROPERTY, AND THE BIOLOGICAL ACTIVITY OF NOVEL NEO-CERAMIDES

  • Kim, Duck-Hee;Lee, Bo-Seaub;Koo, Myeong-Soo;Kim, Hyun-Jun;Lee, Hae-Kwang;Park, Moon-Jae;Lee, Ok-Sub
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.24 no.3
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    • pp.6-16
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    • 1998
  • Ceramides are currently emerging as the major skin care ingredients due to !heir barrier properties in the stratum corneum of the human skin. Thus, major cosmetic companies have developed synthetic ceramide analogs for their own use. In this study, several ceramide mimic compounds , new skin barrier lipids, were designed and synthesized, and their physical and biological properties were investigated to evaluate their skin care capability. Several structures were designed from the variation of hydrophobic alkyl chain and hydrophilic moiety by the use of molecular modeling software. The selected targets were synthesized, and their properties and activities were studied as the pure form, in the emulsion, or in the lamellar mixture containing cholesterol and fatty acid. Some compounds, such as 1,3-bis(N-(2-hydroxyethyl)-palmitoylamino)-2-hydroxypropane, enhanced the restoration of skin barrier damaged by SDS(sodium dodecyl sulfate), and by acetone treatment. The rate of restoration was comparable to that of natural ceramides. The synthesized compounds alleviated SDS induced skin irritation and facilitated lamellar phase liquid crystal formation. The treatment of 1,3-Dis(N-(2-hydroxyethyl)-palmitoylam ino)-2-hyd roxypropane on the acetone damaged skin revealed that the compound promoted the recovery of intercellular lipid lamellar structure of stratum corneum layer. The replacement of palmitoyl groups of the compound with shorter alkyl chain gave lower emulsion viscosity and liquid crystal density, suggesting easier formulation and poorer barrier activity. Most of the synthesized compounds were non-irritable in various toxicological tests proving that they can be safely introduced to the skin care formulations.

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Antimicrobial activities and skin barrier improvement effect of Eruca sativa extract (루꼴라(Eruca sativa) 추출물의 항균활성과 피부장벽 개선 효과)

  • Kim, Bora;Kim, Hyun-Soo
    • Food Science and Preservation
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    • v.24 no.2
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    • pp.320-324
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    • 2017
  • Eruca sativa is a rocket plant and a member of the Brassicaceae, which is considered to be an important chemo-preventive plant family. Although Eruca sativa has positive biological effects, the effect of Eruca sativa extract (ES) on improvement of skin barrier function has not been reported. In this study, we investigated the applicability of functional materials by examining a variety of physiological activities of Eruca sativa extract. ES showed anti-microbial activities against Bacillus subtilis, Escherichia coli, and Candida albicans. In particular, antimicrobial activities of ES against B. subtilis was the highest. Additionally, immunohistochemical analysis of protein marker related to keratinocyte differentiation was determined. The treatment by ES (50 mg/L) showed a significant increase of involucrin expression compared with treatment by 0.1% DMSO as a control in skin equivalents, the ES-treated group showed similar level in the expression of involucrin compared to the group treated with the same concentration of WY14643 in $EpiDerm^{TM}$, a three-dimensional model of skin equivalents. These results indicate that ES promotes the expression of protein related to barrier properties of the skin. Therefore, ES may be an effective ingredient for skin barrier improvement.

Improvement in Capacitor Characteristics of Titanium Dioxide Film with Surface Plasma Treatment (플라즈마 표면 처리를 이용한 TiO2 MOS 커패시터의 특성 개선)

  • Shin, Donghyuk;Cho, Hyelim;Park, Seran;Oh, Hoonjung;Ko, Dae-Hong
    • Journal of the Semiconductor & Display Technology
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    • v.18 no.1
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    • pp.32-37
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    • 2019
  • Titanium dioxide ($TiO_2$) is a promising dielectric material in the semiconductor industry for its high dielectric constant. However, for utilization on Si substrate, $TiO_2$ film meets with a difficulty due to the large leakage currents caused by its small conduction band energy offset from Si substrate. In this study, we propose an in-situ plasma oxidation process in plasma-enhanced atomic layer deposition (PE-ALD) system to form an oxide barrier layer which can reduce the leakage currents from Si substrate to $TiO_2$ film. $TiO_2$ film depositions were followed by the plasma oxidation process using tetrakis(dimethylamino)titanium (TDMAT) as a Ti precursor. In our result, $SiO_2$ layer was successfully introduced by the plasma oxidation process and was used as a barrier layer between the Si substrate and $TiO_2$ film. Metal-oxide-semiconductor ($TiN/TiO_2/P-type$ Si substrate) capacitor with plasma oxidation barrier layer showed improved C-V and I-V characteristics compared to that without the plasma oxidation barrier layer.

Application of rapid thermal annealing process to the aluminum induced crystallization of amorphous silicon thin film (비정질 실리콘의 부분적 알루미늄 유도 결정화 공정에서의 급속 열처리 적용 가능성)

  • Hwang, Ji-Hyun;Yang, Su-Won;Kim, Young-Kwan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.2
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    • pp.50-53
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    • 2019
  • In this study, polycrystalline silicon thin film useful for the solar cells was fabricated by AIC(Aluminum Induced Crystallization) process. A diffusing barrier for this process is prepared with $Al_2O_3$. For the maximization of the grain size of the polycrystalline silicon, a selective blasting of the $Al_2O_3$ diffusing barrier was conducted before annealing treatment. The heat treatment for the activation of the amorphous-Si (a-Si) layer was carried out with Rapid Thermal Annealing (RTA) process. Crystallization of the a-Si layer was analyzed with XRD. It was confirmed that a-Si was crystallized at $500^{\circ}C$ and the silicon crystal is observed to be formed and the grain size of the polycrystalline silicon was observed to be $15.9{\mu}m$.

Effects of Minimum Furrow Mulching with Weed Straw and Gravel Furrow Barrier on Soil Conservation at Potato Field in Gangwon Highland (골부초와 자갈대에 의한 고랭지 감자재배지 토양보전 효과)

  • Park, Chol-Soo;Jung, Yeong-Sang;Joo, Jin-Ho;Lee, Won-Jung;Yang, Jae-E.
    • Korean Journal of Environmental Agriculture
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    • v.24 no.1
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    • pp.29-33
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    • 2005
  • To develop proper soil management practices for reducing soil erosion, experiments were carried out by using lysimeters in Pyeongchang highland, Korea. Lysimeters installed at Hoenggye bad 13% slope, 15 m slope length and 3 m width. Lysimeters with 23% slope, 15 m slope length and 3 m width were also installed at Yongsan. Soil textures in Hoenggye and Yongsan lysimeter plots were silty clay loam and sandy loam, respectively. In the lysimeters potato was cultivated, and slant furrow culture and contour culture were applied. Up-down furrow and continuous fallow lysimeter was included in the experiments as a control plot. For the slant furrow and contour culture methods, minimum furrow mulching and gravel barrier were placed at each end of the furrows in the lysimeters from April to October in 2000 and 2001 to prevent soil and nutrient losses. In Heonggye, in two years experiments, average soil loss of 17 Mg/ha was found in the up-down and continuous fallow lysimeter and 2.6 Mg/ha from furrow minimum straw and slant furrow treatment, and 1.8 Mg/ha from slant furrow and gravel bag treatment. In the contour culture, the soil losses were further reduced. In Yongsan, soil loss in the slant furrow culture without any protection treatment was 167 Mg/ha, and the soil loss was reduce to 61 and 86 Mg/ha with minimum straw and gravel bag treatments, respectively. The soil loss could be reduced more than 45% by furrow minimum straw and gravel barrier. The furrow minimum straw or gravel bag barrier successfully reduced soil loss in clay loam soil in Heonggye, but still the treatments were not enough to reduce soil loss in saprolite piled sandy loam soil in Yongsan.

Heat Treatment Effects of Staggered Tunnel Barrier (Si3N4 / HfAlO) for Non-volatile Memory Application

  • Jo, Won-Ju;Lee, Se-Won
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.08a
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    • pp.196-197
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    • 2010
  • NAND형 charge trap flash (CTF) non-volatile memory (NVM) 소자가 30nm node 이하로 고집적화 되면서, 기존의 SONOS형 CTF NVM의 tunnel barrier로 쓰이는 SiO2는 direct tunneling과 stress induced leakage current (SILC)등의 효과로 인해 data retention의 감소 등 물리적인 한계에 이르렀다. 이에 따라 개선된 retention과 빠른 쓰기/지우기 속도를 만족시키기 위해서 tunnel barrier engineering (TBE)가 제안되었다. TBE NVM은 tunnel layer의 전위장벽을 엔지니어드함으로써 낮은 전압에서 전계의 민감도를 향상 시켜 동일한 두께의 단일 SiO2 터널베리어 보다 빠른 쓰기/지우기 속도를 확보할 수 있다. 또한 최근에 각광받는 high-k 물질을 TBE NVM에 적용시키는 연구가 활발히 진행 중이다. 본 연구에서는 Si3N4와 HfAlO (HfO2 : Al2O3 = 1:3)을 적층시켜 staggered의 새로운 구조의 tunnel barrier Capacitor를 제작하여 전기적 특성을 후속 열처리 온도와 방법에 따라 평가하였다. 실험은 n-type Si (100) wafer를 RCA 클리닝 실시한 후 Low pressure chemical vapor deposition (LPCVD)를 이용하여 Si3N4 3 nm 증착 후, Atomic layer deposition (ALD)를 이용하여 HfAlO를 3 nm 증착하였다. 게이트 전극은 e-beam evaporation을 이용하여 Al를 150 nm 증착하였다. 후속 열처리는 수소가 2% 함유된 질소 분위기에서 $300^{\circ}C$$450^{\circ}C$에서 Forming gas annealing (FGA) 실시하였고 질소 분위기에서 $600^{\circ}C{\sim}1000^{\circ}C$까지 Rapid thermal annealing (RTA)을 각각 실시하였다. 전기적 특성 분석은 후속 열처리 공정의 온도와 열처리 방법에 따라 Current-voltage와 Capacitance-voltage 특성을 조사하였다.

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Effect of Edible Coatings Containing Soy Protein Isolate (SPI) on the Browning and Moisture Content of Cut Fruit and Vegetables

  • Shon, Jin-Han;Choi, Yong-Hwa
    • Journal of Applied Biological Chemistry
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    • v.54 no.3
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    • pp.190-196
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    • 2011
  • Effectiveness of edible coatings containing soy protein isolate (SPI), in reducing oxidative browning and moisture loss during storage ($4^{\circ}C$) of cut apples, potatoes, carrots, and onions was investigated. The SPI coatings were shown to have antioxidative activity. Furthermore, addition of carboxymethyl cellulose (CMC) to the formulations significantly improved its antioxidative activity. Oxidative discoloration, as determined by Commission Internationale De I'Eclairage (CIE) lightness ($L^*$), redness ($a^*$), and yellowness ($b^*$) color scale, was significantly reduced (p <0.05) by SPI coating treatments over a storage time of 120 min. Loss of lightness was reduced by SPI coatings with and without CMC. These respectively showed 4.03 and 3.71% change of $L^*$ value compared to 8.56% for control. Browning of the control in cut potatoes was significantly increased by 106.6% in contrast to 34.3 and 35.2% for SPI coatings with and without CMC, respectively. The $b^*$ values also reflected effectiveness of SPI. Moisture barrier effect was significantly better for the treatments, compared to the control. SPI coatings reduced moisture loss in apples and potatoes, respectively, by 21.3 and 29.6% over the control. Cut onions did not show any treatment effect both in terms of browning and moisture loss. SPI coatings prove to be good moisture barrier and antioxidative property.