• Title/Summary/Keyword: Mechanics' Institute

Search Result 2,811, Processing Time 0.031 seconds

M-Zn (M = Sb, V, and Nb) Substituted Strontium Hexaferrites with Enhanced Saturation Magnetization for Permanent Magnet Applications

  • Sapoletova, Nina;Kushnir, Sergey;Ahn, Kyunghan;An, Sung Yong;Choi, Moonhee;Kim, Jae Yeong;Choi, Changhak;Wi, Sungkwon
    • Journal of Magnetics
    • /
    • v.21 no.3
    • /
    • pp.315-321
    • /
    • 2016
  • M-Zn (M = Sb, V, Nb) substituted M-type strontium hexaferrites were prepared by a ceramic method. The phase composition, morphology and magnetic properties were studied by x-ray diffractometry, scanning electron microscopy and vibrating sample magnetometry. Saturation magnetization increases with a substitution up to 75.0 emu/g (2.5 % higher compared to unsubstituted hexaferrite) and then decreases with a further substitution. A coercive field of substituted hexaferrite powders with highest saturation magnetization is more than 3 kOe. Substituted strontium hexaferrite powders prepared in this work are a rare example of high $M_S$ compositions without doping rare-earth elements and would be a promising candidate for a permanent magnet application.

The growth and applicatiion of LBO crystal (LBO 결정성장과 응용)

  • Jinghe Liu;Jianli Li;Kuisheng Yang;Xiyan Zhang;Yagui Lei;Mu Na;Yuqi Zou;Renhua Zhang
    • Journal of the Korean Crystal Growth and Crystal Technology
    • /
    • v.4 no.3
    • /
    • pp.230-237
    • /
    • 1994
  • The paper studies the growth and application of LBO Crystal and points that thermodynamics and dynamics model of crystal growth should be developed in high-$\eta$(viscosity) melt. The measurement on properties of crystal resonator and press-controlled oscillator indicates that this kind of crystal is one kind of piezo-electric crystal materials which has large-market application potentiality.

  • PDF

Development of New Computer Program for Mechanics of Materials and Structural Mechanics Courses (재료역학과 구조역학 수업을 위한 전산프로그램 개발)

  • Lee, Sang Soon
    • The Journal of Korean Institute for Practical Engineering Education
    • /
    • v.3 no.2
    • /
    • pp.106-113
    • /
    • 2011
  • The new computer program, visual SolidMech (ver 2.0), for mechanics of materials and structural mechanics has been developed using visual C++. The visual SolidMech is organized in a format similar to most standard texts on mechanics of materials and structural mechanics. This program consists of a number of menus to perform various calculations as well as a set of dedicated graphical user interfaces. Solutions to problems are given in both graphical and numerical forms. The visual SolidMech will help students develop problem-solving skills by showing them the important factors affecting various problem types, by helping them visualize the nature of internal stresses and member deformations, and by providing them an easy-to-use means of investigating a greater number of problems and variations. This new program can be utilized as a supplement to existing texts in mechanics of materials and structural mechanics.

  • PDF

Etch resist patterning of printed circuit board by ink jet printing technology (잉크젯 인쇄기술을 이용한 인쇄회로기판의 에칭 레지스터 패터닝)

  • Seo, Shang-Hoon;Lee, Ro-Woon;Kim, Yong-Sik;Kim, Tae-Gu;Park, Sung-Jun;Yun, Kwan-Soo;Park, Jae-Chan;Jeong, Kyoung-Jin;Joung, Jae-Woo
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2007.06a
    • /
    • pp.108-108
    • /
    • 2007
  • Inkjet printing is a non-contact and direct writing associated with a computer. In the industrial field, there have been many efforts to utilize the inkjet printing as a new way of manufacturing, especially for electronic devices. The etching resist used in this process is an organic polymer which becomes solidified when exposed to ultraviolet lights and has high viscosity of 300 cPs at ambient temperature. A piezoelectric-driven ink jet printhead is used to dispense $20-40\;{\mu}m$ diameter droplets onto the copper substrate to prevent subsequent etching. In this study, factors affecting the pattern formation such as printing resolution, jetting property, adhesion strength, etching and strip mechanism, UV pinning energy have been investigated. As a result, microscale Etch resist patterning of printed circuit board with tens of ${\mu}m$ high have been fabricated.

  • PDF