• 제목/요약/키워드: Thermal processes

검색결과 1,091건 처리시간 0.023초

연소합성에 의한 크로메이트 내화물 제조 (Chromate Refractory by Combustion Process)

  • 김형순;한정환
    • 한국세라믹학회지
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    • 제31권12호
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    • pp.1437-1442
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    • 1994
  • Self propagating synthesis and thermal explosion of combustion reactions were applied to Al/K2Cr2O7/Al2O3 system as the first stage for a production of magnesia-chromium refractory. Several factors related to products made by two combustion reactions were considered and properties of products were characterised. Two processes were required to preheat upto at least 80$0^{\circ}C$ for the thermal explosion and the self propagating synthesis. These processes were so violent and explosive that alumina as diluent was added to the system in order to absorb the reaction heat and reduce the reaction rate. The products consisted of crystal phases of KAl5O8, Cr2O3, Al2O3, K2CrO4, and K2Al2O4.3H2O. The amount of KAl5O8 and K2Al2O4.3H2O crystal phases of products were decreased with further addition of alumina.

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Flexible Display ; Low Temperature Processes for Plastic LCDs

  • Han, Jeong-In
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2002년도 하계학술대회 논문집
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    • pp.185-189
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    • 2002
  • Flexible displays such as plastic based LCDs and organic light-emitting diodes for mobile communication devices have been researched and developed at KETI in KOREA since 1997. The Plastic film substrate has so poor thermal tolerance and non-rigidness that the fabrication of active devices and panel assembly have to perform at low temperature and pressure. In addition, high thermal expansion of the substrate is also a serious problem for reliable metallic film deposition. In this paper, we investigated particularly on the fundamental characteristics of various plastic substrates and then, suggested novel methods that improve the fabrication processes of plastic LCD panel. In order to maintain stable substrate surface and uniform cell gap during panel assembly, we utilized newly-invented iii and vacuum chuck. Electro-optical characteristics of fabricated plastic LCD are better than or equivalent to those of typical glass based LCDs though it is thinner, lighter-weight and more robust.

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복합 황산염 수화물의 열분해에 의한 Mg-Al 스피넬의 생성반응 (Reaction Processes of the Formation of Mg-Al Spinel by a Thermal Decomposition of a Mixed Sulfate Hydrate)

  • 박홍채;오기동
    • 한국세라믹학회지
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    • 제23권6호
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    • pp.71-75
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    • 1986
  • The forming reaction processes of magnesium aluminate spinel by a thermal decomposition of sulfate hydrate were studied with DTA, TG. SEM and X-ray powder diffraction methods. The hydrous salt composed of the mixture of the two compounds of $MgSO_4$ $6H_2O$ and ${AL_2}({SO_4})_17H_2O_3$ in which both sulfates were crystalline. On heating the hydrous slat the crystalline magnesium and aluminum sulfate anhydride to amorphous alumina magnesium sulfate anhydride decomposed to amorphous magnesia and these amorphous oxides reacted completely each other to form a spinel at $1000^{\circ}C$ The apparent activation energy of forming reaction of spinel was 36.5 kcal/mole($900^{\circ}C$~$1000^{\circ}C$) The crystallite size of spinel obtained at $1000^{\circ}C$ after 1 h was 380$\AA$.

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연구용 원자로 2호기 해체과정 전산모사 (3D Graphic Simulation on the Dismantling Process of the KRR-2)

  • 김성균;정운수;이근우;박진호
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2003년도 춘계학술대회
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    • pp.1199-1204
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    • 2003
  • The 3D simulations of the shielding concrete and the Rotary Specimen Rack(RSR) in the Korea Research Reactor-1&2(KRR-1&2) were carried out in present work. Four main dismantling processes, which are the removal of the RSR, reactor core region, beam tube, and thermal column and activated concrete, were selected for the graphic simulation by the consideration of the activation, worker training, work difficulty and so on. On the basis of these, we constructed their 3D CAD models and then drawn and reviewed their dismantling processes. In this study, the 3D simulation results of the shielding concrete and the RSR among main components are also presented and discussed.

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熱交換 過程을 考慮한 랜킨 사이클의 性能解析 (Analysis of the Rankine Cycle Including Heat Exchange Processes)

  • 정평석;노승탁
    • 대한기계학회논문집
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    • 제10권1호
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    • pp.150-156
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    • 1986
  • 본 논문에서는 열전달을 포함한 사이클 해석의 좀 더 실제적인 경우로서, 주어진 연소가스로부터 랜킨사이클을 사용하여 동력을 추출할 때 최대의 출력을 추출하기 위한 사이클의 운전조건을 고찰하고, 대표적인 랜킨 사이클에 대하여 여러가지 운전조건에 따른 출력등을 계산하여, 그 결과를 고찰하였다.

후판 구조의 각변형 예측 및 제어에 관한 연구 (A Study on the Prediction and Control of Angular Distortion in Thick Weldments)

  • 허주호;김상일
    • Journal of Welding and Joining
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    • 제21권5호
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    • pp.518-524
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    • 2003
  • The block assembly of ship consists of a series of heat processes such as cutting, bending, welding, residual stress relaxation and fairing. With the fast development of computers, the thermal elasto-plastic analysis method has become a versatile tool for practical applications in the ship production. If numerical analysis is proved to be an advantageous tool to predict the residual deformation due to various heat processes, the optimum methods which can remove the welding distortion can be presented at each assembly stage, which will result in great progress in improving the accuracy of block assembly. In order to minimize the weld-induced angular distortion in thick weldments, this paper proposes the optimum groove design for various plate thickness as the distortion control method. The validity of this method has been substantiated by a number of numerical simulations and experiments.

후판 구조의 각변형 예측 및 제어에 관한 연구 (A Study on the Prediction and Control of Angular Distortion in Thick Weldments)

  • 김상일
    • 한국해양공학회지
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    • 제22권6호
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    • pp.100-105
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    • 2008
  • The block assembly of ship consists of a series of heat processes such as cutting, bending, welding residual stress relaxation and fairing With the fast development of computers, the thermal elasto-plastic analysis method has become a versatile tool for practical applications in the ship production. If numerical analysis is proved to be an advantageous tool to predict the residual deformation due to various heat processes, the optimum methods which can remove the welding distortion can be presented at each assembly stage, which will result in great progress in improving the accuracy of block assembly. In order to minimize the weld-induced angular distortion in thick weldments, this paper proposes the optimum groove design for various plate thickness as the distortion control method. The validity of this method has been substantiated by a number of numerical simulations and experiments.

芳香族할라이드의 Hot Atom Chemistry 스캐벤져, 溫度 및 酸素의 效果 (Hot Atom Chemistry of Aromatic Halides : Scavenger, Temperature and Oxygen Effect)

  • 최재호;박용찬;손미자
    • 대한화학회지
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    • 제9권2호
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    • pp.78-80
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    • 1965
  • The organic yields(i.e., fraction of nuclear events resulting in organic compound formation) of the radioactive neutron capture reactions of the halogens in purified aromatic halides have been determined in the liquid and solid state, in the presence of scavenger, elemental halogen for thermal atoms, and in the presence of oxygen. Among the important results are; (1) organic yields of the halides are due in part to hot processes and in part to thermal processes; (2) temperature (from liquid state to solid state); (3) the organic yield of chlorobenzene is the same in the solid phase as in the liquid phase whereas the yields of the bromo-and iodobenzene are higher in the solid.

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Development of Roll-to- Flat Thermal Imprinting Equipment and Experimental Study of Large Area Pattern Replication on Polymer Substrate

  • 이문구;란 슈하이;이수훈;이혜진;;성연욱
    • 한국생산제조학회지
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    • 제18권3호
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    • pp.307-314
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    • 2009
  • Large area micro pattern replication has promising application potential in many areas. Rolling imprint process has been demonstrated as one of the most competitive processes for such micro pattern replication, because it has advantages in low cost, high throughput and high efficiency. In this paper, we developed a prototype of roll-to-flat(R2F) thermal imprint system for large area micro pattern replication process, which is one of the key processes in the fabrication of flexible displays. Experimental tests were conducted to evaluate the feasibility of system and the parameters' effect on the process, such as flat mold temperature, loading pressure and rolling speed. 100mm $\times$ 100mm stainless steel flat mold and commercially available polycarbonate sheets were used for the tests. The experimental results showed that the developed R2F system is suitable for fabrication of various micro devices with micro pattern over large area.

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Treatment Cost Comparison and Development of Sustainability Indices for Microwave Soil Remediation of TPHs(Total Petroleum Hydrocarbons)

  • Kim, Dong Uk;Koo, Ja-Kong
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제20권5호
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    • pp.11-15
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    • 2015
  • The three processes of 1) high- & low-temperature microwave heatings, 2) the soil washing, and 3) the thermal desorption processes in soil remediation are analysed on the treatment cost data for 2003-2012 years. The cost of microwave heating method with at temperature 500-700℃, for 30 minutes, and at 4-6 kW is approximately 10 $/ton (13,000 ₩) due to the deep through heating of micro-wave, the soil washing with chemicals is about 80 $/ton (85,000 ₩) due to the chemicals & duration, and the thermal desorption process is around 40 $/ton (41,000 ₩) from the less efficiency. Furthermore the sustainability has been assessed, and suggestions are made. 1) Green; the minimal environmental footprint, 2) Growth; the least cost, 3) Shared; the social & environmental justice, 4) Smart; the microwave characteristics of deep through irradiation & heating, and 5) Mutuality; the flexibility of the technology. More additives including water, the government support, and public relation are suggested realizing the microwave in this condition is not harmful to human beings.