• 제목/요약/키워드: Solid support

검색결과 356건 처리시간 0.022초

Direct Microwave Sintering of Poorly Coupled Ceramics in Electrochemical Devices

  • Amiri, Taghi;Etsell, Thomas H.;Sarkar, Partha
    • Journal of Electrochemical Science and Technology
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    • 제13권3호
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    • pp.390-397
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    • 2022
  • The use of microwaves as the energy source for synthesis and sintering of ceramics offers substantial advantages compared to conventional gas-fired and electric resistance furnaces. Benefits include much shorter processing times and reaching the sintering temperature more quickly, resulting in superior final product quality. Most oxide ceramics poorly interact with microwave irradiation at low temperatures; thus, a more complex setup including a susceptor is needed, which makes the whole process very complicated. This investigation pursued a new approach, which enabled us to use microwave irradiation directly in poorly coupled oxides. In many solid-state electrochemical devices, the support is either metal or can be reduced to metal. Metal powders in the support can act as an internal susceptor and heat the entire cell. Then sufficient interaction of microwave irradiation and ceramic material can occur as the sample temperature increases. This microwave heating and exothermic reaction of oxidation of the support can sinter the ceramic very efficiently without any external susceptor. In this study, yttria stabilized zirconia (YSZ) and a Ni-YSZ cermet support were used as an example. The cermet was used as the support, and a YSZ electrolyte was coated and sintered directly using microwave irradiation without the use of any susceptor. The results were compared to a similar cell prepared using a conventional electric furnace. The leakage test and full cell power measurement results revealed a fully leak-free electrolyte. Scanning electron microscopy and density measurements show that microwave sintered samples have lower open porosity in the electrode support than conventional heat treatment. This technique offers an efficient way to directly use microwave irradiation to sinter thin film ceramics without a susceptor.

Synthesis, Characterization and Application of Poly(4-vinylpyridine)-Supported Brønsted Acid as Reusable Catalyst for Acetylation Reaction

  • Borah, Kalyan Jyoti;Dutta, Papia;Borah, Ruli
    • Bulletin of the Korean Chemical Society
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    • 제32권1호
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    • pp.225-228
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    • 2011
  • Poly(4-vinylpyridine)-supported $Br{\phi}nsted$ acids (P4VP-HX) were prepared by wet impregnation technique. These supported acids were found as efficient heterogeneous green catalysts for acetylation of alcohol, amine and phenol with different catalytic activities. The wide application of P4VP-HX as reusable solid acid catalyst in organic reactions is possible because of its simple preparation and handling, stability, simple work up procedure.

오스테나이트계 스테인리스강 레이저 용접부의 응고균열 거동 (Part 2) - δ 페라이트 정출 및 응고편석 거동에 따른 응고균열 민감도 변화 - (Solidification Cracking Behavior in Austenitic Stainless Steel Laser Welds (Part 2) -Effects of δ-ferrite Crystallization and Solidification Segregation Behavior on Solidification Cracking Susceptibility-)

  • 천은준;이수진;서정;강남현
    • Journal of Welding and Joining
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    • 제34권5호
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    • pp.61-69
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    • 2016
  • A numerical simulation of the solid/liquid coexistence temperature range, using solidification segregation model linked with the Kurz-Giovanola-Trivedi model, explained the mechanism of the BTR shrinkage (with an increase in welding speed) in type 310 stainless steel welds by reduction of the solid/liquid coexistence temperature range of the weld metal due to the inhibited solidification segregation of solute elements and promoted dendrite tip supercooling attributed to rapid solidification of laser beam welding. The reason why the BTR enlarged in type 316 series stainless welds could be clarified by the enhanced solidification segregation of impurity elements (S and P), corresponding to the decrement in ${\delta}-ferrite$ crystallization amount at the solidification completion stage in the laser welds. Furthermore, the greater increase in BTR with type 316-B steel was determined to be due to a larger decrease in ${\delta}-ferrite$ amount during welding solidification than with type 316-A steel. This, in turn, greatly increases the segregation of impurities, which is responsible for the greater temperature range of solid/liquid coexistence when using type 316-B steel.

조성변화에 따른 세라믹지지체의 제조 및 그 특성 (Changes in the composition according to the manufacturer and the characteristics of the ceramic support)

  • 권용진;최병현;지미정;안용태;설광희;남산
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2011년도 추계학술대회 초록집
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    • pp.83.2-83.2
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    • 2011
  • In this study, we fabricated tubular ceramic support for segmented-in-series solid oxide fuel cell (SOFC) by using MAO(MgAl-stabilized ) as main material and activated carbon as pore former. Thermal expansion properties of ceramic support with different amounts of activated carbon were analyzed by using dilatometer to decide a suitable sintering temperature. The tubular ceramic supports with different amounts of activated carbon (15, 20, 30wt.%) were fabricated by the extrusion technique. After sintering at $1400^{\circ}C$ for 2h, cross section and surface morphology of tubular ceramic support were analyzed by using SEM image. Also, the porosity, mechanical property, gas permeability of tubular ceramic supports was measured. Based on these results, we established the suitable fabrication technique of tubular ceramic support for segmented-in-series SOFC.

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흉부 CT 영상에서 다중 뷰 영상과 텍스처 분석을 통한 고형 성분이 작은 폐 간유리음영 결절 분류 (Classification of Ground-Glass Opacity Nodules with Small Solid Components using Multiview Images and Texture Analysis in Chest CT Images)

  • 이선영;정주립;이한상;홍헬렌
    • 한국멀티미디어학회논문지
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    • 제20권7호
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    • pp.994-1003
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    • 2017
  • Ground-glass opacity nodules(GGNs) in chest CT images are associated with lung cancer, and have a different malignant rate depending on existence of solid component in the nodules. In this paper, we propose a method to classify pure GGNs and part-solid GGNs using multiview images and texture analysis in pulmonary GGNs with solid components of 5mm or smaller. We extracted 1521 features from the GGNs segmented from the chest CT images and classified the GGNs using a SVM classification model with selected features that classify pure GGNs and part-solid GGNs through a feature selection method. Our method showed 85% accuracy using the SVM classifier with the top 10 features selected in the multiview images.

Covalent Binding of DNA onto Glass Support for the Construction of Genosensor

  • 정우성;백세환
    • 한국생물공학회:학술대회논문집
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    • 한국생물공학회 2000년도 추계학술발표대회 및 bio-venture fair
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    • pp.709-710
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    • 2000
  • 유전자센서 기술은 biomedical analysis를 위해 일반적으로 고체 상에 고정화된 DNA 분자를 이용한다. 이 센서의 검출능력은 주로 capture probe의 서열뿐만 아니라 oligonucleotide의 고체 상에 고정화 방법에 달려있다. 본 연구에서는 glass 표면에 DNA 분자를 고정화시키는 두 가지 다른 방법을 비교하였고 유전자센서의 구성에 대해 검토하였다.

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Immobilization of Polysiloxane Liquid Phase on the Gas Chromatographic Solid Supports via In-Situ Cross-Linking

  • Kim, Kyoung-Rae;Zlatkis, Albert
    • Bulletin of the Korean Chemical Society
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    • 제8권3호
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    • pp.133-137
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    • 1987
  • Polysiloxane SE-54 liquid phase was immobilized on the support surface as coated in thin film via in-situ cross-linking. The cross-linking between liquid molecules was initiated by dicumylperoxide. Among the supports investigated, only Chromosorb W provided the cross-linkable surface. The optimal in-situ cross-linking was achieved when Chromosorb W was coated with 5% (w/w) SE-54 and cross-linked with 1% (w/w) dicumylperoxide. The cross-linked support was useful for the trace analysis as well as for the trace enrichment.

Ecofriendly Synthesis of Antifungal Azoles

  • Kidwai, M.;Mohan, R.
    • 대한화학회지
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    • 제48권2호
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    • pp.177-181
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    • 2004
  • 1,2,4-트라이아졸, 피라졸론, 그리고 1,3,4-옥사다이아졸을 마이크로파 쬐임(MWI) 하에서 여러 가지 고체지지체를 이용하여 치환기가 있는 하이드라자이드로부터 합성하였다. 그 얻어진 실험 결과들은 고체지지체의 다양성을 보여준다. 합성한 모든 유도체들을 A. niger와 A. flavus 균주에서 항진균성활성도를 조사한 하였으며 좋은 활성을 보여 주었다.

금속지지체형 고체산화물 연료전지의 열 및 물질전달 특성에 대한 전산해석 (Numerical Analysis of the Heat and Mass Transfer Characteristics in Metal-Supported Solid Oxide Fuel Cell)

  • 박준근;김선영;배중면
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 추계학술대회 논문집
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    • pp.143-146
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    • 2009
  • The metal-supported SOFC has beed developed as a new concept of SOFC which has higher mechanical strength. However, the mass transfer rate in this type of SOFC may be decreased due to the contact layer and the support layer and that can cause the low performance. Therefore, numerical analysis of the heat and mass transfer characteristics in a metal-supported solid oxide fuel cell(SOFC) is studied in this paper. Governing equations and electrochemical equations are calculated simultaneously. And the numerical results are compared with the experimental results for the code validation. The current density, temperature, and pressure drop are suggested as numerical results.

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Concept, Manufacture and Results of the Microtubular Solid Oxide Fuel Cell

  • Sammes, Nigel;Galloway, Kevin;Yamaguchi, Toshiaki;Serincan, Mustafa
    • Transactions on Electrical and Electronic Materials
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    • 제12권1호
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    • pp.1-6
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    • 2011
  • This paper summarized concept, manufacture and results of the micro-tubular solid oxide fuel cells (SOFCs). The cells were fabricated by co-sintering of extruded micro-tubular anode support and electrolyte coating layer, and then additional cathode coating. The cells showed quick voltage rising within 1 minute, and the electrochemical performances were closely related to the balance of fuel utilization and performance loss. And a thermal-fluid simulation model was also reported in combination with the electrochemical evaluation results on the GDC-based micro-tubular SOFCs.