and+Engineer
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KAIST Team Identifies Nano-scale Origin of Toughness in Rare Earth-added Silicon Carbide
A research team led by Prof. Do-Kyung Kim of the Department of Materials Science and Engineering of KAIST has identified the nano-scale origin of the toughness in rare-earth doped silicon carbide (RE-SiC), university sources said on Monday (Oct. 6).
The research was conducted jointly with a U.S. team headed by Prof. R. O. Ritchie of the Department of Materials Science and Engineering, University of California, Berkeley.
The findings were carried in the online edition of Nano Letters published by the American Chemical Association.
Silicon carbide, a ceramic material known to be one of the hardest substances, are potential candidate materials for many ultrahigh-temperature structural applications. For example, if SiC, instead of metallic alloys, is used in gas-turbine engines for power generation and aerospace applications, operating temperatures of many hundred degrees higher can be obtained with a consequent dramatic increase in thermodynamic efficiency and reduced fuel consumption. However, the use of such ceramic materials has so far been severely limited since the origin of the toughness in RE-SiC remained unknown thus far.
In order to investigate the origin of the toughness in RE-SiC, the researchers attempted to examine the mechanistic nature of the cracking events, which they found to occur precisely along the interface between SiC grains and the nano-scale grain-boundary phase, by using ultrahigh-resolution transmission electron microscopy and atomic-scale spectroscopy. The research found that for optimal toughness, the relative elastic modulus across the grain-boundary phase and the interfacial fracture toughness are the most critical material parameters; both can be altered with appropriate choice of rare-earth elements.
In addition to identifying the nano-scale origin of the toughness in RE-SiC, the findings also contributed to precisely predicting how the use of various rare-earth elements lead to difference in toughness.
University sources said that the findings will significantly advance the date when RE-SiC will replace metallic alloys in gas-turbine engines for power generation and aerospace applications.
2008.10.08 View 13937 -
Women Leaders Awarded Honorary Degrees
Korea"s two women leaders, Park Geun-hye, former President of the Grand National Party, and Lee Gil-ya, chairperson of the Gachon Gil Foundation, a major medical services organization, were awarded honorary doctorate degrees by KAIST, Korea"s state-run science and technology research university, on Feb. 29.
It is the first time in the school"s 37-year history that women have been awarded honorary doctorate degrees. Park and Lee were conferred with the honor during the university"s 2008 graduation ceremony in recognition of their achievements in social services.
KAIST President Suh Nam-pyo said that the university decided to confer honorary doctorate degrees to Park and Lee, who both have educational backgrounds in the fields of engineering and science, in order to present role models to female students in science and engineering who still make up a relatively small percentage of the total enrollment at KAIST and throughout Korean universities.
"Our graduates and future students will strive to make meaningful contributions to the nation and the world, just as the two women leaders have done so well, for so many years," said Suh in his commencement address.
Female students constitute 23 percent of the total enrollment of 7,800, including graduate and doctorate students.
The honorary doctorate citation said Park Geun-hye, a graduate of the Department of Electronic Engineering, Sogang University in Seoul, has exerted strenuous efforts for the advancement of science and technology education and women"s social role. Among other things, Park called for the launching of a "second-stage science and technology revolution" during her 2007 presidential campaign. She declared science and technology as "the most crucial area of national development and survival" and instituted seven-point strategies to innovate the nation"s science and technology. Those strategies are specifically aimed at increasing investment in science and technology, fostering a world-class science and technology university and creating science-friendly curriculum at schools.
Lee Gil-ya, a widely-revered medical doctor, has demonstrated outstanding leadership in education, culture, journalism and business management, according to her citation. Throughout her brilliant professional career, she has vigorously pursued her lifelong goal of philanthropy, social service and patriotism. In particular, her dedication to nurturing young talents is widely recognized in Korea.
2008.03.05 View 12846 -
Professor Jongwon Lee wins Korean Engineering Award
Professor Jongwon Lee wins Korean Engineering Award
Professor Jongwon Lee of the department of Mechanical Engineering won the 7th Korean Engineering Award conferred by the Ministry of Science and Technology and Korean Science and Engineering Foundation.
Professor Lee is a world-famous scholar in the field of ‘dynamics and vibration of rotors’ and his work in 1993, ‘Vibration Analysis of Rotors’, is highly recognized as a creative and practical research on the dynamics of rotors.
The Korean Engineering Award is conferred on domestic scientists who have made world-level research achievements in the engineering field by the Ministry of Science and Technology and Korean Science and Technology Foundation every two years.
2007.01.11 View 12202