Ultrafine WC-10wt.%Co cemented carbides powders were synthesized by direct carburization. W-Co composite powders and carbon black powders were mixed by wet ball milling and dried. The mixed powders were heated to 800 with heating rate of 8.2/min and held for various times in flowing . For carbon addition of 140%, the carburization was completed by heating at 80 for 4 hours. The carburization time decreased with increasing amount of carbon and carburization was completed by heating at 800 for 2 hours with carbon addition of 150%. WC-10 wt%Co cemented carbides powders fabricated by direct carburization have nanoscale WC(100 nm) size.

A radically new approach to the in situ synthesis of the consituent phases of a composite structure has enabled the production of a new WC/Co materials with an ultrafine microstructure. The process for synthesizing nanophase WC/Co powders consists of spray drying from solution to form a homogeneous precursor powder, and thermochemical conversion of the precursor powder to the nanophase WC/Co powder. Near theoretical density of pure nanophase WC-10 wt%Co has been obtained in only 30 sec at 140. But WC particles were grown up very rapidly with longer sintering time to get full density. To overcome coarsening of WC particle during sintering, VC, TaC and VC/TaC were used as the grain growth inhibitor with different amount respectively. VC/TaC doped WC-10 wt%Co was shown superior hardness and TRS and microstructure was maintained ultrafine scale (average WC size is less than 0.1 ).

Cu-10wt%W composite powders have been manufactured by a high energy ball milling technique. The composite powders were pressed at 250 MPa and sintered in a dry hydrogen at 103 for 4 hours. After sintering, Cu-10wt%W composite materials were forged. And the arc-resistance of forged materials which have the same relative density of 94% has been tested. Composite particles, i.e. tungsten particles distributed homogeneously in the copper matrix, was formed after 480 min mechanical alloying. Densities of these sintered materials were ranged from 74 to 84%. Densification degree was due to the formation of composite powders. As the mechanical alloying time increased, the hardness was increased and tungsten particle size was decreased. Arc loss of the forged specimens was decreased as increasing the mechanical alloying time.

Needs for more accurate greenhouse gas (GHG) emission estimation are increasing to prepare for post-Kyoto protocol and emission trading starting from 2015 in Korea. Although GHG emission from landfill is relatively low, uncertainty of methane emissions from landfill is very high compared to the other sectors. Moreover, accurate estimation is needed to design landfill gas collection system and energy generation plant. In this paper, we investigated development methodologies of parameters comprising methane generation potential (L0) which is one of key parameters in methane emission estimation models. DOC included four steps including analysis of waste component, water content, organic carbon content, fossil carbon content. Instead of analysis of organic carbon content and fossil carbon content, biochemical analysis, measuring content of cellulose, hemicellulose, and lignin, is used in MELMod, landfill gas generation model in UK. Methodologies to develop DOCF has several methods including batch test, lysimeter test and test cell. They had difference in scale and similarity to landfill, but it is hard to consider the best method at the present stage. Preceding research on MCF is little. Lysimeter test and test cell can be the candidate to develop MCF, because of flexibility on test condition to characterize the structure of landfill sites. F is defined as fraction of methane in landfill gas. But by carbon flow and mass balance, F should represent fraction of methane in biogas generated by anaerobic decomposition. In this definition, F can be derived by same methods to that of DOCF.