Combustion synthesis has been used to produce Fe-(Ti,W)C composites. A simple reactor was designed which made it possible to ignite the samples under controlled atmosphere. Samples with different W/Ti ratio were ingnited under argon atmosphere by an electric arc and a self-propagating reaction was initiated in each sample. Different composites such as WC in Fe-Ti matrix, WC+(Ti,W)C in Fe matrix...

By using the [Fe ii] lambda8617/[O i] lambda6300 flux ratio, we demonstrate that most of the interstellar dust grains survive in shocks associated with supernova remnants and Herbig-Haro objects. The [Fe ii]/[O i] flux ratio is sensitive to the gas-phase Fe/O abundance ratio but is insensitive to the ionization state, temperature, and density of the gas. We calculate the [Fe ii]/[O i] flux rati...

We have determined elemental abundance ratios in the core of the Perseus cluster for several elements. These ratios indicate a central dominance of SN Ia ejecta similar to that found for A496, A2199 and A3571 (Dupke & White 2000a). Simultaneous analysis of ASCA spectra from SIS1, GIS 2&3 shows that the ratio of Ni to Fe abundances is ∼ 3.4 ± 1.1 times Solar within the central 4. This ratio is c...

Ilmenite, aluminum and graphite can be used to produce in-situ Al2O3/TiC–Fe composites which are used as cutting tools. Few publications can be found in the literature that discusse the effect of molar ratio of aluminum and graphite on the Al2O3/TiC–Fe formation mechanism. Therefore, the present research is designed to make the issue clear.  To achieve this goal, at first, the mechanism o...

From equivalent widths of the S i lines at 8694 Å, Israelian & Rebolo (2001) and Takada-Hidai et al. (2002) have derived a surprisingly high sulphur-to-iron ratio ([S/Fe] ≃ 0.5 to 0.7) in six halo stars with [Fe/H] ≃ −2.0 suggesting perhaps that hypernovae made a significant contribution to the formation of elements in the early Galaxy. To investigate this problem we have used high-resolution s...

Ilmenite is a valuable industrial mineral containing Fe and Ti elements. Two composites with different morphology and composition were produced using the reaction of synthesized ilmenite and aluminum. The molar ratios of 1:2 and 1:8 were selected. The critical temperatures of each molar ratio were determined using the Differential Thermal Analysis (DTA). The heat treatment of the systems ...

Copper abundances are presented for 40 red-giant members of the massive Galactic globular cluster ω Centauri, as well as 15 red-giant members of the globular clusters NGC288, NGC362, NGC3201, NGC6752, and M4 (NGC6121). The spectra are of relatively high spectral-resolution and signal-to-noise. Using these abundances, plus published literature values for field stars, the abundance trends of [Cu/...

Metal–olivine Fe–Ni exchange distribution coefficients were determined at 1500 8C over the pressure range of 1 to 9 GPa for solid and liquid alloy compositions. The metal alloy composition was varied with respect to the Fe/Ni ratio and the amount of dissolved carbon and sulfur. The Fe/Ni ratio of the metal phase exercises an important control on the abundance of Ni in the olivine. The Ni abunda...