• 제목/요약/키워드: Wet cell

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Study on the Development of Wet Cell Holder for the Measurement of Hydrophilic Contact Lens (친수성 콘택트렌즈 측정용 Wet Cell 홀더 개발에 관한 연구)

  • Song, Kyoung-Sek;Lim, Hyeon-Sun;Joo, Seok-Hee
    • Journal of Korean Ophthalmic Optics Society
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    • v.20 no.4
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    • pp.455-462
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    • 2015
  • Purpose: To develop more accurate wet measuring system combining the wet cell, automatic lensmeter and the related software for hydrophilic contact lenses and to verify the accuracy of those measuring holder system already available in the market. Methods: Refractive power measurement were done in both a conventional method which has been commonly used in optical shops and a new method which is recently developed in korea. Hydrophilic contact lens of korean brand was chosen as a test material and was tested by water content ratio and by spherical refractive power. Results: When spherical power of -3.00 D contact lens is measured in the newly developed wet cell measurement holder with automatic lensmeter, it reads -3.01 D at water content ratio of 38%. -3.00 D at 45% and -2.98 D at 58%. The same experiment with the Poster soft contact lens wet cell measurement holder maintaining other conditions same resulted in -3.60 D at the water content ratio of 38%, -3.06 D at 45% and -2.46 D at 58%. Conclusions: At the higher water content, the refractive power values measured by both of the wet cell measuring holders are shown lower, and additionally, the new method using the wet cell holder and new software program in a automatic lensmeter showed more accurate readings than conventional Poster soft contact lens wet cell measuring system.

A Study of Characterization of Multi-Crystalline Silicon Solar Cell Module using by RIE and Wet Texturing for BIPV (BIPV용 건식 및 습식 텍스쳐링 공정에 의한 다결정실리콘 태양전지 모듈 특성 연구)

  • Seo, Il-Won;Yun, Myung-Soo;Jo, Tae-Hoon;Son, Chan-Hee;Cha, Sung-Ho;Lee, Sang-Du;Kwon, Gi-Chung
    • New & Renewable Energy
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    • v.9 no.2
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    • pp.30-39
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    • 2013
  • Multi-crystalline silicon solar cells is not exist a specific crystal direction different from single crystalline silicon solar cells. In functional materials, therefore, isotropic wet etching of mc-Si solar cell is easy the acid solution rather than the alkaline solution. The reflectance of wet texturing process is about 25% and the reflectance of RIE texturing process is achieved less than 10%. In addition, wet texturing has many disadvantages as well as reflectance. So wet texturing process has been replaced by a RIE texturing process. In order to apply BIPV, RIE and wet textured multi-crystalline silicon solar cell modules was manufactured by different kind of EVA sheet. Moreover, in case of BIPV, the short circuit current characteristics according to the angle of incidence is more important, because the installation of BIPV is fixed location. In this study, we has measured SEM image and I-V curve of RIE and wet textured silicon solar cell and PV module. Also we has analyzed quantum efficiency characteristics of RIE and wet textured silicon solar cell for PV modules depending on incidence angle.

Reliability of Measurements of Back Vertex Power for Soft Contact Lenses Using an Auto-Lensmeter (자동렌즈미터를 이용한 소프트 콘택트렌즈의 굴절력 측정 방법에 관한 신뢰도)

  • Kim, Kun-Kyu;Lee, Wook-Jin;Lee, Sun-Haeng;Kwak, Ho-Won;Yu, Dong-Sik
    • Journal of Korean Ophthalmic Optics Society
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    • v.15 no.1
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    • pp.39-46
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    • 2010
  • Purpose: To assess the reliability for measuring the back vertex power of soft contact lenses by dry blotting and wet cell method using an auto-lensmeter. Methods: The soft contact lenses used for measurement were 5 types that were distributed in Korea, and 4 back vertex powers (-1.50D, -3.00D, -6.00D, -9.00D) were used. and repeatability and reproducibility were evaluated by measuring them with an auto-lensmeter by two examiners. Results: Measured powers by dry blotting method were ranged in mean differences from 0.03D to 0.18D for overall lenses, 0.10D to 0.18D for silicone hydrogel lenses, 0.03D to 0.08D for hydrogel lenses. The mean differences between two examiners were less than 0.10D, and the inter-examiner reproducibility was good for dry blotting method. The mean difference between powers determined by wet cell method were 0.09D to 0.69D, the mean differences between two examiners were 0.02D to 0.59D. The reliability of measurements and inter-examiner reproducibility were less than dry blotting method. Conclusions: The reliability of measurements for all materials was better in dry blotting than wet cell method, the re liability of measurements for silicone hydrogel lenses was low in both methods. In clinical practical which requires quick checking of back vertex power using an auto-lensmeter. dry blotting method is thought to be more efficient than wet cell one.

Synthesis and Characterization of Polyurethane for Artificial Leather Using Bio Polyol (바이오 폴리올을 이용한 인공피혁 코팅용 폴리우레탄의 합성 및 특성)

  • Sur, Suk-Hun;Choi, Pil-Jun;Ko, Jae-Wang;Lee, Jae-Yeon
    • Textile Coloration and Finishing
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    • v.30 no.4
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    • pp.321-328
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    • 2018
  • Wet polyurethane resin was synthesized by using polytrimethylene ether glycol prepared from 1,3-propanediol produced by fermentation from corn sugar as bio polyol and polyether-polyol(PTMG). Physical properties and cell characteristics by wet coagulation were investigated using the synthesized wet polyurethane resin. The tensile strength of wet polyurethane resin decreased with increasing content of bio polyol as copolymer polyol, but it tended to increase elongation at break and tear strength. As a result of thermal characteristic analysis, it was found that the glass transition temperature was slightly increased as the content of bio polyol increased. As a result of comparing the cell characteristics by the wet coagulation method, it was found that the shape of the cell was good when the ether polyol and the bio polyol were used alone.

STUDY ON THE HIGH EFFICIENCY BURIED CONTACT SOLAR CELL WITH WET ETCHING PROCESS

  • Kang, Dae-Keun;Choi, Kang-Ho;Lee, Joo-Yul;Lee, Kyu-Hwan
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2009.10a
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    • pp.156-156
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    • 2009
  • High efficiency silicon solar cell technology based on planar technology has been improved by various kinds of process by using the wet etching process. In particular, the buried contact solar cell has been successfully studied. In the present work, a simplified process of the buried contact solar cell has been suggested to help one design effectively the high-efficiency solar cell.

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Alkali metal free texturing for mono-crystalline silicon solar cell (알카리 금속을 배재한 단결정 실리콘 태양전지의 텍스쳐링 공정)

  • Kim, Taeyoon;Kim, Hoechang;Kim, Bumho
    • 한국신재생에너지학회:학술대회논문집
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    • 2010.11a
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    • pp.48.1-48.1
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    • 2010
  • Mono-crystalline silicon solar cell is fabricated by using alkali metals. These alkali metal, used in wet etching process, must be removed for the high efficiency solar cell. As wet etching process has been adapted due to its low cost. But lots of alkali metals like potassium remains on the silicon surface and acts as impurities. To remove these alkali metals many of cleaning process have to be applied when solar cell manufacturing process. In terms of alkali metal removal, modified etchant solution is required for concise cleaning process. In this paper ethylenediamine was used and proposed for the substituion of postassium hydroxide.

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The Cytotoxic Effect of Oral Wet Wipes on Gingival Cells (시판 중인 구강청결티슈의 세포 독성 관찰)

  • Jung, Im-hee;Park, Ji Hyeon;Lee, Min Kyeng;Hwang, Young Sun
    • Journal of dental hygiene science
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    • v.18 no.2
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    • pp.76-84
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    • 2018
  • Wet wipes are being increasingly used because of their convenience. Particularly, oral wet wipes are useful for regular cleaning of a baby's mouth after birth. Therefore, the consumption of oral wet wipes has increased over the past few years and a variety of products are commercially available. However, product information on safety is not sufficiently provided and still raises doubts regarding adverse effects. To confirm the safety of wet wipes as an oral hygiene item and provide information for their use, we investigated the cytotoxicity of oral wet wipes and verified the underlying mechanism. The anti-bacterial effect of oral wet wipes was analyzed using the disk diffusion method. The cytotoxic effects of oral wet wipes were observed based on morphological changes using microscopy and determined using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in gingival epithelial cells and gingival fibroblasts. Evaluation of apoptosis by oral wet wipes was explored using propidium iodide flow cytometric analysis and a terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate (dUTP) nick-end labeling (TUNEL) assay. Apoptosis-related molecules were also analyzed using western blotting. Five types of oral wet wipes were tested, and two products from Fisher-Price and Dr. Kennedy revealed strong cytotoxic effects on gingiva epithelial cells and gingiva fibroblasts, although they also showed intense anti-bacterial effects on oral bacteria. Cell cycle arrest in the G2/M phase and apoptosis were observed based on treatment of extracts from Fisher-Price and Dr. KENNEDY. Relatively high TUNEL levels, reduction of proliferating cell nuclear antigen and cyclin-dependent kinase 4 expression, and fragmentation of poly (ADP-ribose) polymerase were also elucidated. These results suggest that commercial oral wet wipes could exert cytotoxic influences on oral tissue, although there are anti-bacterial effects, and careful attention is required, especially for infants and toddlers.

In vitro Glutathione Production using Mixed Cells in an Aerated Slurry Bioreactor (혼합세포를 이용한 Aerated Slurry Bioreactor에서의 in vitro Glutathione 생산)

  • Go, Seong-Yeong;Gu, Yun-Mo
    • KSBB Journal
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    • v.14 no.4
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    • pp.445-451
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    • 1999
  • Glutathione production was carried out using mixed cells of E. coli TG1/pDG7 $\alpha$ and bakers yeast in an Aerated Slurry Bioreactor. Glutathione-producing enzymes were stable for 34 hours, yielding 4.6 mM glutathione in suspension reaction. Glutahione production with high density mixed cells was studied as a function of flow rate in an Aereated Slurry Bioreactor. Glutathione concentration was higher than that in suspension reaction for 32 hours at the substrate feeding rate of 5.2 mL/hr with cell recycle in continuous Aerated Slurry Bioreactor. It was for 42 hours at 2.6 mL/hr and 22 hours at 5.2 mL/hr without cell recycle. Glutahione productivity was 25.7 mg/g wet $cell{\cdot}hr$ at the substrate feeding rate of 10.4 mL/hr with cell recycle, but 5.28 mg/g wet $cell{\cdot}hr$ at 5.2 mL/hr and 1.65 mg/g wet $cell{\cdot}hr$ at 2.6 mL/hr without cell recycle. Effective production time increased from 25 to 45 hours, by using a surfactant, tween 80. As a purfing gas, nitrogen was tested instead of air to avoid a possible oxidizing effect on glutathione-producing enzymes, resulting in the increase of effective production time to 40 hours.

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Effects of Prevention on the Cow Mastitis Based on Functional Non-woven Finishing Products (기능성 부직포 후가공 제품에 의한 젖소 유방염 예방효과)

  • Hong, Young-Ki;Lee, Mun-Soo
    • Textile Coloration and Finishing
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    • v.18 no.6 s.91
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    • pp.57-62
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    • 2006
  • The functional non-woven fabrics have been applied in various industry fields, such as clothing, hygiene, environment, medical and so forth. The functional non-woven fabrics for wet tissue were manufactured by meltblown and wet tissue finishing processes. The wet tissue was contained the various composition substances such as Benzalkonium Chloride(0.2292g), lodo-2-propynyl Butyl carbamate(0.0069g) and 5-Chloro-2-Methyl-Isothiazolin -3-one, 2-Methyl-Isothiazolin-3-one (0.0034g) with purified water (999.76g). In this study, the functional wet tissue based on meltblown nonwovens has been applied in dairy cattle for prevention on cow mastitis. Mastitis is the most costly disease results in lost milk production, decreased milk quality, milk discard, early culling of cows, drug costs and labor costs in dairy cattle. Therefore, this study was investigated to evaluate clinical effect of the functional wet tissue in mastitis control. The results, after experiment the functional wet tissue used group, demonstrated that the infection rate, cure rate and mean somatic cell count(SCC) were significantly decreased as compared to the control group.

Surface Analysis and Conversion Efficiency of Multi-crystalline Silicon Solar Cell by Wet Chemical Etching (습식 화학 식각에 의한 다결정 실리콘 웨이퍼의 표면 분석 및 효율 변화)

  • Park, Seok-Gi;Do, Kyeom-Seon;Song, Hee-Eun;Kang, Gi-Hwan;Ahn, Hyung-Keun;Han, Deuk-Young
    • 한국태양에너지학회:학술대회논문집
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    • 2011.04a
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    • pp.111-115
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    • 2011
  • Surface Texturing is an essential process for high efficiency in multi-crystalline silicon solar cell. In order to reduce the reflectivity, there are two major methods; proper surface texturing and anti-reflection coating. For texturization, wet chemical etching is a typical method for multi-crystalline silicon. The chemical solution for wet etching consists of HF, $NHO_3$, DI and $CH_3COOH$. We carried out texturization by the change of etching time like 15sec, 30sec, 45sec, 60sec and measured the reflectivity of textured wafers. As making the silicon solar cells, we obtained the conversion efficiency and relationship between texturing condition and solar cell characteristics. The reflectivity from 300nm to 1200nm was the lowest with 15 sec texturing time and 60 sec texturing time showed almost same reflectivity as bare one. The 45 sec texturing time showed the highest conversion efficiency.

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