The mechanical and chemical properties of transition metal nitrides are very attractive for numerous industrial applications. Thin nitride films are expected to be good diffusion barrier in microelectronic devices. Ni...The mechanical and chemical properties of transition metal nitrides are very attractive for numerous industrial applications. Thin nitride films are expected to be good diffusion barrier in microelectronic devices. Nitrogen diffuses into the whole thickness of the molybdenum film heated at low temperature and exposed to expanding plasma of (Ar-N2-H2) compared with pure N2 plasma. NHx species in the plasma are produced by different homogeneous or heterogeneous reactive mechanisms that results in an expansion of the plasma compared with pure N2 plasma. NHx species and probably H atoms improve the transfer of nitrogen into the metal by preventing the formation of MoO2 oxides which act as a barrier of diffusion for nitrogen.展开更多
The mechanical and physical properties of TUFF from Korsimoro (Burkina Faso) were investigated for use as admixtures in clinker to make pozzolanic cement. Six different cement mortar specimens were prepared by replaci...The mechanical and physical properties of TUFF from Korsimoro (Burkina Faso) were investigated for use as admixtures in clinker to make pozzolanic cement. Six different cement mortar specimens were prepared by replacing clinker with TUFF in ratios of 0%, 5%, 8%, 10%, 13% and 15% by mass. The flexural and compressive strengths of the specimens were determined at the ages of 2, 7, 28 and 60 days. The effects of the TUFF replacement ratio on workability, setting time and volume expansion were also examined. Based on the results, it was concluded that Korsimoro TUFF has pozzolanic activity and is suitable for use as an alternative adherent material in the cement industry.展开更多
文摘The mechanical and chemical properties of transition metal nitrides are very attractive for numerous industrial applications. Thin nitride films are expected to be good diffusion barrier in microelectronic devices. Nitrogen diffuses into the whole thickness of the molybdenum film heated at low temperature and exposed to expanding plasma of (Ar-N2-H2) compared with pure N2 plasma. NHx species in the plasma are produced by different homogeneous or heterogeneous reactive mechanisms that results in an expansion of the plasma compared with pure N2 plasma. NHx species and probably H atoms improve the transfer of nitrogen into the metal by preventing the formation of MoO2 oxides which act as a barrier of diffusion for nitrogen.
文摘The mechanical and physical properties of TUFF from Korsimoro (Burkina Faso) were investigated for use as admixtures in clinker to make pozzolanic cement. Six different cement mortar specimens were prepared by replacing clinker with TUFF in ratios of 0%, 5%, 8%, 10%, 13% and 15% by mass. The flexural and compressive strengths of the specimens were determined at the ages of 2, 7, 28 and 60 days. The effects of the TUFF replacement ratio on workability, setting time and volume expansion were also examined. Based on the results, it was concluded that Korsimoro TUFF has pozzolanic activity and is suitable for use as an alternative adherent material in the cement industry.
