Effects of liquid phase and reinforcing particle morphology on the sintering of Al-6 wt％Cu-10 vol％ or SiC particles were studied in regards to densification, structure and transverse rupture properties. The Al-Cu liquid phase penetrated the boundaries between the aluminum matrix powders and the interfaces with reinforcing particles as well, indicating a good wettability to the powders. This enhanced the densification during sintering and the resulting strength and ductility. Since most of the copper added, however, was dissolved in the liquid phase and formed a brittle phase upon cooling rather than alloyed with the aluminum matrix, the strengthening effect by the copper was not fully realized. Reinforcing particles of agglomerate type were found less suitable for the liquid phase sintering than solid type particles. and SiC particles protluced little difference on the sintering behavior but their size had a large effect. Repressing of the sintered composites increased density and bending properties but caused debonding at the matrix-particle interfaces and also fracturing of the particles.

Over the last decades, increasing natural disasters and climate change are considered as the major environmental problems facing the globe. Numerous studies have been indicated it would cause huge losses on agriculture, especially in the grain productivity. Therefore, several alternatives are suggested for boosting up productivity of wheat as one of the main human food crop. One of important strategy is proper management of inflorescence development and DELLA proteins have been elucidated to play pivotal roles in growth of many plant organs. In this study, putative negative regulator of DELLA protein, GAST (Gibberellic acids stimulated transcript) have been isolated to identify their role in the developing spike of wheat. Four genes were isolated from its gene family and designated as TaGAST1, 2, 3, 4. Genomic structure was analyzed to demonstrate chromosomal localization of TaGAST genes and evolutionary relationships were also verified with GAST genes in other plant species. RT-PCR was conducted to detect transcriptional changes of TaGAST genes on external phytohormone. Each of TaGAST genes showed considerable changes in transcription level after GA, ABA, PAC treatment, respectively. Through Yeast two-hybrid assay, one protein for TaGAST1, and four proteins for TaGAST2 was isolated as putative interactive proteins in wheat spikes just before and after emergence.