• 제목/요약/키워드: Advanced techniques

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미세조직 정량 분석을 통한 고체산화물 연료전지용 NiO-YSZ 연료극 전기전도도 예측 (Quantitative Microstructure Analysis to Predict Electrical Property of NiO-YSZ Anode Support for SOFCs)

  • 완디 와휴디;빌랄 아메드;이승복;송락현;이종원;임탁형;박석주
    • 한국수소및신에너지학회논문집
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    • 제24권3호
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    • pp.237-241
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    • 2013
  • The correlation between NiO-YSZ microstructure and its electrical property used for SOFC anode was critically evaluated with image processing and direct measurement techniques. These innovative processing techniques were employed to quantify the contiguity of the anode constituent phase. The calculated contiguities were then correlated with electrical conductivity attained from 4-probe DC method. This investigation described that contiguity of nickel oxide phases of an anode has a linear relationship with its electrical conductivity. We observed that the contiguity of NiO increased from 0.18 to 0.50 then electrical conductivity attained was significantly increased from 520 S/cm to 1468 S/cm at $900^{\circ}C$.

Variation of optimization techniques for high dose rate brachytherapy in cervical cancer treatment

  • Azahari, Ahmad Naqiuddin;Ghani, Ahmad Tirmizi;Abdullah, Reduan;Jayamani, Jayapramila;Appalanaido, Gokula Kumar;Jalil, Jasmin;Aziz, Mohd Zahri Abdul
    • Nuclear Engineering and Technology
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    • 제54권4호
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    • pp.1414-1420
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    • 2022
  • High dose rate (HDR) brachytherapy treatment planning usually involves optimization methods to deliver uniform dose to the target volume and minimize dose to the healthy tissues. Four optimizations were used to evaluate the high-risk clinical target volume (HRCTV) coverage and organ at risk (OAR). Dose-volume histogram (DVH) and dosimetric parameters were analyzed and evaluated. Better coverage was achieved with PGO (mean CI = 0.95), but there were no significant mean CI differences than GrO (p = 0.03322). Mean EQD2 doses to HRCTV (D90) were also superior for PGO with no significant mean EQD2 doses than GrO (p = 0.9410). The mean EQD2 doses to bladder, rectum, and sigmoid were significantly higher for NO plan than PO, GrO, and PGO. PO significantly reduced the mean EQD2 doses to bladder, rectum, and sigmoid but compromising the conformity index to HRCTV. PGO was superior in conformity index (CI) and mean EQD2 doses to HRCTV compared with the GrO plan but not statistically significant. The mean EQD2 doses to the rectum by PGO plan slightly exceeded the limit from ABS recommendation (mean EQD2 dose = 78.08 Gy EQD2). However, PGO can shorten the treatment planning process without compromising the CI and keeping the OARs dose below the tolerance limit.

숭례문 장여 제작 기법을 통해 본 여말선초 건축 기술 연구 (Research on Architectural Technology from Late Goryeo to Early Joseon through the Examination of Bracket Tie Beam Manufacturing Techniques in Sungnyemun Gate)

  • 김석현
    • 건축역사연구
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    • 제33권1호
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    • pp.45-60
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    • 2024
  • This study aims to examine the cutting traces remaining on the bracket tie beams of Sungnyemun gate, identifying the tools employed during the late Goryeo to early Joseon periods by specific processes, and deliberating on the timber shaping techniques utilized in advanced architectural construction during the late Goryeo to early Joseon eras. Through the research, it was confirmed that in the production of Sungnyemun Gate's bracket tie beams during the 14th to 15th centuries, both the timber splitting and ripsawing methods were used in conjunction. Moreover, the wood finishing process revealed the use of a plane. It can be inferred that the characteristics of the plane used during that time were not significantly different from those observed in the later period of the Joseon dynasty. The ripsawing and plane finishing techniques were evident in various parts of the bracket tie beams of Sungnyemun gate across the reigns of king Taejo and Sejong, indicating that the techniques involving ripsaw and plane were already prevalent in the late Goryeo period. Consequently, it can be inferred that the ripsawing and plane finishing techniques might have been applied in the construction of prominent government buildings in Hanyang(Seoul), including Gyeongbokgung Palace, and in the residences of royalty and nobility after the establishment of the Joseon dynasty.

NONDESTRUCTIVE/IN-FIELD CHARACTERIZATION OF TENSILE PROPERTIES AND RESIDUAL STRESS OF WELDED STRUCTURES USING ADVANCED INDENTATION TECHNIQUE

  • Park, Yeol;Dongil Son;Kim, Kwang-Ho;Park, S. Joon;Jang, Jae-il;Dongil Kwon
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2002년도 Proceedings of the International Welding/Joining Conference-Korea
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    • pp.668-674
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    • 2002
  • Structural integrity assessment is indispensable for preventing catastrophic failure of industrial structures/components/facilities. This diagnosis of operating components should be done periodically for safe maintenance and economical repair. However, conventional standard methods for mechanical properties have the problems of bulky specimen, destructive and complex procedure of specimen sampling. Especially, the mechanical properties at welded zone including weldment and heat affected zone could not be evaluated individually due to their size requirement problem. So, an advanced indentation technique has been developed as a potential method for non-destructive testing of in-field structures. This technique measures indentation load-depth curve during indentation and analyzes the mechanical properties related to deformation such as yield strength, tensile strength and work-hardening index. Also indentation technique can evaluate a residual stress based on the concept that indentation load-depth curves were shifted with the direction and the magnitude of residual stress applied to materials. In this study, we characterized the tensile properties and welding residual stress of various industrial facilities through the new techniques, and the results are introduced and discussed.

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Direct Printable Nanowire p-n Junction device

  • Lee, Tae-Il;Choi, Won-Jin;Kar, Jyoti Prakash;Moon, Kyung-Ju;Lee, Min-Jung;Jun, Joo-Hee;Baik, Hong-Koo;Myoung, Jae-Min
    • 한국재료학회:학술대회논문집
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    • 한국재료학회 2010년도 춘계학술발표대회
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    • pp.30.2-30.2
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    • 2010
  • Nano-scale p-n junction can generate various nano-scale functional devices such as nanowire light emitting diode, nanowire solar cell, and nanowire sensor. The core shell type nanowire p-n junction has been considered for the high efficient devices in many previous reports. On the other hand, although device efficiency is relatively lower, the cross bar type p-n junction has simple topological structure, suggested by C.M. Lieber group, to integrate easily many p-n junction devices in one board. In this study, for the integration of the cross bar nanowire p-n junction device, a simple fabrication route, employed dielectrophoretic array and direct printing techniques, was demonstrated by the successful fabrication and programmable integration of the nanowire cross bar p-n junction solar cell. This direct printing process will give the single nanowire solar cell the opportunity of the integration on the circuit board with other nanowire functional devices.

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첨단소재 및 성형법을 사용한 조선기자재의 개발 (Development of Marine Equipment Using New Materials and Fabrication Method)

  • ;한중원;최병근;김윤해
    • Journal of Advanced Marine Engineering and Technology
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    • 제25권1호
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    • pp.74-86
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    • 2001
  • With the advanced composites technologies and designs advancing faster than ever in the past then years, it has extremely important to keep up with technology by introducing new manu-facturing techniques to advance the industy even more. Specifically, the marine related indus-tries. The United States has preparing for the future by aerospace composite technology to the boat, canoe, kayak and naval vessel busin. This paper will describe one of the methods being implemented to improve quality and structural integrity to compete in the world market.

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Epitaxial Self-Assembly of Block Copolymer Thin Film for Nanofabrication

  • Kim, Sang-Ouk
    • 한국고분자학회:학술대회논문집
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    • 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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    • pp.293-293
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    • 2006
  • Self-assembled nanostructures of block copolymer thin films have gathered significant attention due to their potential applications as templates for nanofabrication. However the lack of a robust strategy to control the structure formation in thin film geometries has been considered a major obstacle for the practical application. In this presentation 'epitaxial self-assembly' will be introduced as a successful strategy to control the self-assembled nanostructure of block copolymer. Chemically patterned surfaces prepared by advanced lithographic techniques successfully registered nanodomains in block copolymer thin film without any single defect over an arbitrarily large area.

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정전형 MEMS 검출기의 새로운 Offset 보상 방법 (New Offset-compensation Technique for Capacitive MEMS-Sensor)

  • 민동기;전종업
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2001년도 하계학술대회 논문집 C
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    • pp.1896-1898
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    • 2001
  • An offset problem caused by the static parasitic capacitors is analyzed and then some techniques to reduce their effect on the capacitive position sensor are presented. Also new offset compensation technique is proposed that by adjusting the magnitudes of the modulating signals independently, the charge imbalance between electrodes caused by the parasitic capacitors is eliminated without sensor gain variation. Simulation results are given to validate the proposed compensation technique.

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Corrosion in Batteries

  • Muniyandi, N.
    • Corrosion Science and Technology
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    • 제2권1호
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    • pp.1-6
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    • 2003
  • A comprehensive coverage of corrosion in batteries is rendered difficult by the wide choice of materials, environments and physical features as obtained in practical settings. Understanding of the complex processes that occur in these electrochemical systems gets clearer as new theoretical approaches backed by sophisticated analytical and characterization techniques continue to provide valuable insights which aid in controlling/mitigating wasteful corrosion reactions which affect battery shelf-life, cycle life, rate capability and capacity. In the light of the above, I limit myself to a discussion on corrosion aspects in representative system such as conventional Leclanche, lead-acid battery and magnesium batteries, and advanced lithium systems.

촉매연소의 신기술 동향 (Status and perspectives of the advanced catalytic combustion)

  • 강성규
    • 한국연소학회:학술대회논문집
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    • 대한연소학회 2003년도 제27회 KOSCO SYMPOSIUM 논문집
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    • pp.299-308
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    • 2003
  • This paper provides a review of the status and of the perspectives of advanced catalytic combustion for ultra clean combustion of gas turbines and for industrial combustors. The development of catalytic materials and their combustion techniques for gas turbines are briefly reported. The fuel-rich approaches to catalytic combustion are mentioned for a new technology of thermal- and fuel-NOx control. The fuel-rich catalytic combustion are also applicable to the combustor of ceramic gas turbine, and to the combustion of biomess and municipal waste sludge. Some extended technologies of combustion synthesis are introduced for the synthesis of carbon nanotube and of Perovskite combustion catalysts

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