Papers by Keyword: Theory

Paper TitlePage

Authors: Lin Feng Wu, Xiao Chun Yin, Zhong Hua Liu
Abstract: The torsion bar system model of a 150-ton convertor tilting mechanism was made by using APDL language of the finite element software ANSYS.And the diameter of the torsion bar and the fillet radius were optimized based on the above analysis by using optimal module.A new 150-ton convertor was developed by the optimal results and has been in good performance since 2006.The results show that the optimal structure of torsion bar was more economic and reasonable than the traditional structure.Optimization scheme can all be given access to safe,economical and reliable design results and ensure the converter performance.Moreover, this method provides three-dimensional, multi-touch, irregular structure with a valuable experience and a new idea and can be extended to the design of heavy products.
Authors: Peter Deák, Adam Gali, Z. Hajnal, Thomas Frauenheim, Nguyen Tien Son, Erik Janzén, Wolfgang J. Choyke, P. Ordejón
Authors: G. Trumpy, M.D. Bentzon
Authors: E. Rauls, Uwe Gerstmann, M.V.B. Pinheiro, Siegmund Greulich-Weber, Johann Martin Spaeth
Abstract: In a combined theoretical and experimental work, we have investigated the common DI photoluminescence in 6H-SiC material. We present an atomistic model which is able to explain the annealing behavior, i. e. the correlation with the silicon vacancy, the local vibrational modes and the excitonic-like character observed.
Authors: Zhong Ren Zhou
Abstract: Biomass energy is an important component of household energy consumption in rural areas of China. However, under current exploitation levels, the energy source is beset with both theoretical and practical challenges, and its sustainable utilization is seriously restricted. One key to solving this problem is the establishment of a theoretical framework for the sustainable use of biomass energy by rural households. Based on the new viewpoint that biomass energy is a type of ‘weakly’ renewable energy, this paper provides the first theoretical basis outlining the sustainable use of biomass energy in rural households, including systems theory, the theory of ecological carrying capacity, the utility theory, the theory of ecological economics and the theory of natural resource values. The relationships among these theories are also discussed. In addition, four conditions governing the theoretical sustainable use of biomass energy by rural households are analyzed: the sustainability of the resource supply, the sustainability of biomass energy production, the sustainability of consumer acceptance, and the sustainability of ecological environmental effects.
Authors: T. Hornos, Adam Gali, Nguyen Tien Son, Erik Janzén
Abstract: We have investigated several aluminum-related complexes in 4H-SiC by ab initio supercell calculations. The binding energies of the defects predict high thermal stability and complex formation between aluminum and carbon interstitials in SiC. We show that the carbon vacancy can be attached to a shallow the aluminum acceptor and form a very stable defect. We also found that aluminum interstitial forms stable and metastable complexes with one or two carbon interstitials. The possible relation of these defects to the recently found aluminum- related DLTS centers is also discussed.
Authors: Hoda Eskandari, Ho Sung Kim
Abstract: A theory for mathematical framework is developed with axioms for fatigue damage, quantification and relativity concept, boundary conditions, and compatibility, allowing us to evaluate the validity of candidate damage equations/quantities on S-N plane for prediction of fatigue life. Manifestation points for accumulated damage were defined for boundary conditions by differentiating between damage accumulated before failure, and failure caused by damage at quantised fatigue loading cycles. A selected damage equation leading to a theoretical S-N curve was validated as an example.
Authors: Anthony D. Rollett
Abstract: A theory for abnormal grain growth (AGG) in polycrystalline materials is revisited and extended in order to predict AGG in textured polycrystals. The motivation for the work is to improve our understanding of the origins of the Goss texture component, {110}<001>, during annealing of Fe-Si sheet. Since the AGG phenomenon in grain-oriented electrical steels is known to be dependent on the presence of a dispersion of fine second phase particles, the grain boundary properties are treated as representative of the homogenized behavior of the material, and not necessarily the properties that would be measured directly. The predictions of AGG are presented in the form of maps in Euler space, showing which texture components are most likely to grow abnormally. For different models of grain boundary properties applied to a theoretically derived texture, different sets of texture components are predicted to grow; neither model, however, predicts growth of the Goss component.
Showing 1 to 10 of 75 Paper Titles