• Title/Summary/Keyword: Shaping Process

Search Result 292, Processing Time 0.034 seconds

New Technique of Spatial Printing of Materials for Arbitrary Shape Forming (임의의 형상 성형을 위한 새로운 공간 직접 성형 기술)

  • 이일한;정용재;김창경
    • Journal of the Korean institute of surface engineering
    • /
    • v.33 no.2
    • /
    • pp.107-114
    • /
    • 2000
  • In this study, we investigated the possibility of the application of the EzROBO system to direct shaping techniques which can make arbitrary shapes without any specific mold. We formed arbitrary shapes using raw materials of EH-260D (Epoxy+Binder) with the conditions of $250\mu\textrm{m}$ layer thickness, 0.2MPa working pressure, 20mm/sec working velocity, and 1.8mm needle thickness. The developed Spatial Printing Technique showed enhanced working velocity and lower cost than existing 3DP process, and is expected to replace the existing process through the process optimization in the future.

  • PDF

A Study on the Manufacturing Process of Fe-Ti Type Electrode for Ni/MH Secondary Battery (Ni/MH 2차전지용 Fe-Ti계 전극 제조공정에 대한 연구)

  • Joung, Sang-sik;Kim, Ki-won;Ahn, Hyo-jun;Joung, Soon-dol
    • Transactions of the Korean hydrogen and new energy society
    • /
    • v.9 no.2
    • /
    • pp.65-75
    • /
    • 1998
  • Five different processes were selected and tested to find an useful method of manufacturing Fe-Ti type electrode. Initially, FeTi alloy was prepared by melting in plasma arc furnace and then powdered for shaping. Electroless Ni plating on these powder particles before shaping improved the discharge characteristics. The effects of heat-treatments on the electrode characteristics were also investigated. The discharge capacities of electrods were increased with the increasing heat-treatment temperatures. When heat treated at $1000^{\circ}C$ after shaping, the best results were acquired in the discharge capacity and cycle life. Both electroless Ni plating and heat-treatment were appeared to be crucial for the performance improvement of FeTi type electrode. Fe-Ti -Mn electrodes were prepared according to the process suggested in this study and tested to verify the promising effects of that.

  • PDF

The shaping process of Masan urban landscape (마산시 경관의 형성과정에 관한 연구)

  • ;Ok, Han Seok
    • Journal of the Korean Geographical Society
    • /
    • v.26
    • /
    • pp.15-51
    • /
    • 1982
  • 이 글에서는 다음의 내용을 다루었다. 1. 마산의 입지조건과 합포.마산포의 형성, (1) 마산의 입지조건, (2) 합포와 포산포의 형성 2. 신마산의 등장과 단일욱시의 성립, (1) 신마산의 등장, (2) 단일욱시의 성립 3. 마산의 인구팽창과 동마산의 성장, (1) 마산의 인구팽창, (2) 동마산의 성장, (3) 마산시의 입체경관(skyline)

  • PDF

Zigzag Tool-Path Linking Algorithm for Shaping Process Using Heat Source (열원을 이용한 공정에서 지그재그 공구 경로 연결 알고리즘)

  • Kim H. C.;Lee S. H.;Yang D. Y.
    • Korean Journal of Computational Design and Engineering
    • /
    • v.9 no.4
    • /
    • pp.286-293
    • /
    • 2004
  • Recently, hot processing using the heat source like laser machining and RFS was developed and spreaded gradually. In order to generate tool-path for the proper hot tool, a new tool-path linking algorithm is needed because tool-path linking algorithm for machining can't be applied. In this paper, zigzag tool-path liking algorithm was proposed to generate tool-path automatically for RFS. The algorithm is composed of three steps: 1) Generating valid tool-path element, 2) Storing tool-path elements and creating sub-groups, 3) linking sub-groups. Using the proposed algorithm, CAD/CAM software for the tool-path generation of hot tool was developed. The proposed algorithm was applied and verified for Venus's face and die of cellular phone case.

A Model for the Relation between Strength and Porosity in Sintered Parts Produced by Powder Injection Molding Process (분말사출성형을 통해 제조된 소결체의 기공율에 따른 강도예측모델)

  • 성환진;하태권;안상호;장영원
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2003.05a
    • /
    • pp.375-378
    • /
    • 2003
  • In the present study, a new approach to predict the strength of sintered materials has been carried out and a new framework combining neck growth model and ideal pore model has been established based on the results of tensile tests on powder injection molded specimens with the various porosity. Powder injection molding (PIM) uses the shaping advantage of injection molding but is applicable to metals and ceramics. PIM delivers structural materials in a shaping technology previously restricted to polymers. 17-4 PH stainless steel powders with average diameters of 10 $\mu\textrm{m}$ were injection-molded into flat tensile specimens sintered at the various temperatures ranging from 900 to 1350$^{\circ}C$ for 1h. The relationships between strength and porosity were applied to the experimental results and verified.

  • PDF

The Political Economy of Nuclear Reactors and Safety (원자로의 정치경제학과 안전)

  • Park, Jin-Hee
    • Journal of Engineering Education Research
    • /
    • v.15 no.1
    • /
    • pp.45-52
    • /
    • 2012
  • The success history of Light Water Reactors (PWR and BWR) showed how a dominant technology could be shaped in a political and economical context. The american nuclear politics, the interest of american nuclear industry, and the accumulated technological know-hows made it possible that the not inherently safe reactor-Light Water Reactor- became a prominent reactor model. The path dependency of reactor technology on LWR kept the engineers from developing a new safer reactor, even if the severe reactor accidents occurred. In oder to increase safety of nuclear power system, we should understand the social shaping process of nuclear technology.

A Study on the Effect of Tool Thermal Deformation on Surface Profiles for Turing Process (선삭에서 공구열변형이 표면 형상에 미치는 영향에 관한 연구)

  • 염철만;신근하;홍민성
    • Transactions of the Korean Society of Machine Tool Engineers
    • /
    • v.10 no.4
    • /
    • pp.33-39
    • /
    • 2001
  • During the turning of the workpiece, cutting heat causes thermal deformation of the cutting tool which influences the surface characteristics of the machined part. This paper presents a study of thermal deformation of the cutting tool. For this purpose, cutting tool is modeled based of Pro/Engineering and the thermal deformation is simulated by means of the finite element method. The thermal effect on the surface roughness profile is simulated by using surface-shaping system. It has been shown that the results of simulation are similar to those of experiment.

  • PDF

The role of mitochondria in apoptosis

  • Jeong, Seon-Yong;Seol, Dai-Wu
    • BMB Reports
    • /
    • v.41 no.1
    • /
    • pp.11-22
    • /
    • 2008
  • Apoptosis (programmed cell death) is a cellular self-destruction mechanism that is essential for a variety of biological events, such as developmental sculpturing, tissue homeostasis, and the removal of unwanted cells. Mitochondria play a crucial role in regulating cell death. $Ca^{2+}$ has long been recognized as a participant in apoptotic pathways. Mitochondria are known to modulate and synchronize $Ca^{2+}$ signaling. Massive accumulation of $Ca^{2+}$ in the mitochondria leads to apoptosis. The $Ca^{2+}$ dynamics of ER and mitochondria appear to be modulated by the Bcl-2 family proteins, key factors involved in apoptosis. The number and morphology of mitochondria are precisely controlled through mitochondrial fusion and fission process by numerous mitochondria-shaping proteins. Mitochondrial fission accompanies apoptotic cell death and appears to be important for progression of the apoptotic pathway. Here, we highlight and discuss the role of mitochondrial calcium handling and mitochondrial fusion and fission machinery in apoptosis.