Magnetic properties of nanostructured materials are affected in complicated manner by their microstructure such as pain size (or particle size), internal strain and crystal structure. Thus, studies on the synthesis of nanostructured materials with controlled microstructure are necessary fur a significant improvement in magnetic properties. In the present work, nanostructured Fe-Co alloy powders with a grain size of 50 nm were successfully fabricated from the powder mixtures of (99.9% purity) and by chemical solution mixing and hydrogen reduction.

The microstructure and mechanical property of hot-pressed nanocomposites with a different temperature for atmosphere changing from to Ar have been studied. When the atmosphere changed from to Ar gas at , the hot-pressed composite was characterized by inhomogeneous microstructure and low fracture strength. On the contrary, when the atmosphere changed at a lower temperature of , a more homogeneous microstructure and higher fracture strength was observed.

The effect of Cu on the hydrogen reduction of powders was investigated by measuring the humidity change during a non-isothermal process of hydrogen reduction. The presence of Cu induced a shift in the reduction temperature and strongly affected the reduction processes of , which comprised the contained chemical vapor transport of . This study suggests that the surface of the Cu grains acts as a nucleation site for the reduction of to particles from or . Such an activated reduction process results in the deposition of Mo and particles on the surface of the Cu.

In this investigation, based ceramic composites were fabricated by in-situ reaction hot pressing using , TiC SiC powder as starting materials. The reaction synthesized composites by hot pressing at was found to posses very high relative density. The reaction synthesized composites comprise , , SiC and graphite by the reaction between TiC and . The newly formed and graphite was embedded both inside grain and at grain boundary . The mechanical properties of reaction synthesized -graphite composites were more enhanced compared to those of monolithic .

The aging behavior of sintered Al composites with various ceramic contents was investigated. 2xxx series blended powder was used as the starting powder. Ceramic contents were 0wt.% and 5wt.%. The blended powders were compacted at 250MPa. The sintering process was performed at for 60min in a atmosphere. Each part was solution-treated at for 60min and aged at . The Rockwell hardness at the peak aging time increased with ceramic contents. However, the peak aging time at maximum hardness was reduced with increased ceramic contents.

Mechanical properties of 7xxx series Al metal matrix composite (MMC) powders containing different amounts of ceramic were investigated. The ceramic contents of the starting powders were 5 wt.% or 10 wt.%. The powders were uniaxially cold compacted using a cylindrical die with a compacting pressure of 250 MPa and were sintered at in a dry atmosphere for 60 min. For the heat treatment, sintered parts were solution treated at and aged at . Compression tests were conducted to reveal the effect of particle content on the mechanical properties of the composites. Fractography was examined using a scanning electron microscope.

Cr2AlC was synthesized by a reactive hot pressing of CrCx (x=0.5) and Al powder mixture used as starting materials at the temperature range of 1200 oC~1400 oC under 25 MPa in Ar atmosphere. Fully dense Cr2AlC with high purity was synthesized by hot pressing CrCx and Al powder mixture at the temperature as low as 1200 oC. The average grain size of synthesized bulk Cr2AlC was varied in the range of 10-100 ㎛ depending on hot pressing temperatures. The maximum flexural strength of synthesized bulk Cr2AlC exceeded 600 MPa.

Magnetic properties of nanostructured materials are affected by the microstructures such as grain size (or particle size), internal strain and crystal structure. Thus, it is necessary to study the synthesis of nanostructured materials to make significant improvements in their magnetic properties. In this study, nanostructured Fe-20at.%Co and Fe-50at.%Co alloy powders were prepared by hydrogen reduction from the two oxide powder mixtures, and . Furthermore, the effect of microstructure on the magnetic properties of hydrogen reduced Fe-Co alloy powders was examined using XRD, SEM, TEM, and VSM.

This study provided the status and efficiency of the domestic wastewater sea outfalls based on the previous numerical and experimental studies for the analysis of the buoyant discharges from Rosette diffuser in shallow water. The VISJET model and the hybrid model proposed by Kim (2002) can be proper models for the domestic sea outfalls. The experimental results show that the merging height for MBR and MIR depends on the riser diameter and spacing between risers, and the bending characteristics of the buoyant discharges in still ambient water have significant impacts on the dilution. The current wastewater outfall systems in Korea are not effective for the environmental aspect due to the low discharge water depth. The strategies to reduce the contamination near the domestic wastewater outfalls were found to require the sufficient discharge water depth, proper diffuser location considering the tidal currents, enough riser diameter, and sufficient spacing between risers.