• 제목/요약/키워드: Caustic

검색결과 170건 처리시간 0.023초

태양전지용 규소의 texture etching에 미치는 초음파의 영향 (The effect of the ultrasonic wave on the texturisation of the silicon crystal-line solar cell)

  • 김정민;김영관
    • 한국결정성장학회지
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    • 제13권6호
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    • pp.261-266
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    • 2003
  • 결정질 규소를 이용한 태양전지의 제조에 필요한 texture 식각 공정에 초음파를 적용하였다. 이 결과 $60^{\circ}C$에서 초음파를 적용하여 식각된 규소 기판으로 제조된 태양전지의 광전변환효율이 기존의 방식대로 $70^{\circ}C$에서 초음파 없이 식각된 규소 기판으로 제조된 태양전지의 광전변환효율보다 높았다. 이 결과는 규소를 이용한 태양전지의 제조에 필요한 식각공정에서 초음파를 적용하면 공정 온도를 낮출 수 있고 또한 사용되는 고가의 용액을 줄일 수 있어 전체적으로 태양전지의 제조 가격을 낮출 수 있는 가능성을 보여준다.

하인두 및 위의 손상을 동반한 급성 부식성 식도손상의 외과적 치료 (Surgical Treatment for Acute Caustic Injury of the Hypopharynx, Esophagus, and Stomach -Two Cases-)

  • 김형곤;이삼윤;최종범
    • Journal of Chest Surgery
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    • 제28권10호
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    • pp.935-938
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    • 1995
  • Two cases of severe caustic injury of the hypopharynx, esophagus, and stomach are presented. Restoration of digestive continuity was accomplished by retrosternal isoperistaltic interposition of the transverse and left colon on the post-injury 73rd and 66th day respectively. The upper oro-colon continuity was made by a cervical approach, a vertical incision at the posterior hypopharyngeal wall, and interrupted one-layer sutures using 3-0 Dacron suture materials. The distal continuity was made by colojejunostomy between the transposed colon and proximal jejunum. There was no event after the operation in both cases. The posterior vertical hypopharyngotomy and hypopharyngocolostomy at the early post-injury period may be the preferred procedure to obtain normal deglutition in patients with esophageal stricture associated with hypopharyngeal injury.

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유기산 처리가 해도형 초극세 폴리에스터 섬유의 용출 특성에 미치는 영향 (1) (Accelerating Effect of Organic Acid Treatment on Weight Reduction Characteristics of Sea-Island Type PET Supermicrofiber (1))

  • 김혜인;정천희;민문홍
    • 한국염색가공학회지
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    • 제24권1호
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    • pp.45-53
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    • 2012
  • In order to make a supermicrofiber fabric with PET/co-PET sea-island type filament fiber, the optimum conditions of dissolution of co-PET composite filament fiber was examined. The data set was made at various organic acid concentration and steam temperature with treated time as a main variable. At the same time, the microstructure changes by organic acid treatment of sea-island type PET supermicrofibers were monitored by thermal analysis morphology, DSC thermgrams and SEM images. Weight reduction behavior of supermicrofibers by caustic treatment was investigated in a comparative method. The termination of dissolution was also confirmed using DSC thermgrams and SEM images.

일메나이트 상에서 물의 광분해에 의한 수소의 생성 (Hydrogen Formation by Photo-splitting of Water on Ilmenite)

  • 최임규;하백현
    • 태양에너지
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    • 제8권1호
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    • pp.49-56
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    • 1988
  • Thermally treated Korean ilmenite was characterized and used for water splitting to obtain hydrogen by photo-catalytic reaction. Experiments on specific surface area, X-ray diffraction and EDS showed that the formation of FeO, $Fe_2O_3$ and $TiO_2$ ilmenite crystal surface increased the specific surface area with maximum value, phase change of $TiO_2$ at $600^{\circ}C$ and hetrogeneity. The hydrogen evolved in caustic soda solution on these ilmenites indicated that there was a maximum yield point at about $600^{\circ}C$. This point was explained with the change of the surface area due to sintering of newly formed FeO, $Fe_2O_3$ and $TiO_2$, as well as crystal phase change of anatase to rutile at $600^{\circ}C$. Produced hydrogen increased also as the concentration of caustic soda, but become constant at the near 1N solution.

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Microwave Effect on Curing of Waterborne Polyurethane

  • Lee, Hoi-Kwan;Fang, Chris. Y.;Pantano, Carlo. G.;Kang, Won-Ho
    • Bulletin of the Korean Chemical Society
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    • 제32권3호
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    • pp.961-963
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    • 2011
  • Spin-coated waterborne polyurethane to protect glass surface from environmental attacks was cured by using microwave heating. The effect of microwave heating on the reaction kinetics, chemical durability, and transmittance of polyurethane was investigated. In comparison to the conventional heating the results show that the microwave heating substantially accelerates the curing process of waterborne polyurethane and the total time for the completion of the reaction is only 1/7 of that in the conventional process. The microwave cured sample showed an excellent caustic resistance compared to conventional cured one. It means that microwave heating produces dense structure during curing process. The dense structure does not affect to the transmittance in the visible region.

정전위법에 의한 Alloy 600 및 Alloy 690의 Caustic 분위기에서의 부식저항성 비교

  • 맹완영;강영환;남태운
    • 한국원자력학회:학술대회논문집
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    • 한국원자력학회 1996년도 추계학술발표회논문집(2)
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    • pp.475-480
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    • 1996
  • Alloy 600 및 Alloy 690의 Caustic 분위기에서, 시편의 포텐셜을 재료의 anodic polarization curve의 active-passive transition 영역의 한 값으로 일정하게 유지함으로서 응력부식균열을 쉽게 유발시키는 정전위 시험방법을 사용하여, 두 합금의 부식저항성을 비교하였다. C-ring형태의 Alloy 600 및 690 시편에 응력을 부과하고 30$0^{\circ}C$의 10% NaOH용액에서 7일간 정전위 응력부식시험을 수행하였다. Alloy 600의 경우, 입계를 따르는 100$\mu$m정도 깊이의 균열이 발생하였으나 Alloy 690의 경우는 균열이 유발되지 않았다. Alloy 690의 경우 부식 시험시간이 경과함에 따라 표면부식전류밀도는 주기적인 Passivation 경향을 보이나 Alloy 600의 경우는 점진적으로 표면부식전류밀도가 증가한다. Alloy 690의 강한 응력부식저항성은 이와 같은 주기적인 Passivation에 의한 것으로 판단된다.

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