To develop an effective process for titanium powder production, a new preform reduction process (PRP), based on the calciothermic reduction of preform containing titanium oxide (TiO
2), was ...investigated. The feed preform was fabricated from slurry, which was made by mixing TiO
2 powder, flux (e.g. CaCl
2) and binder. Various types of preforms in the form of plates, spheres, or tubes were prepared using a conventional technique, and the fabricated preform was sintered at 1073 K before reduction in order to remove the binder and water. The sintered solid preform containing TiO
2 was then placed in a stainless steel container, and reacted with calcium vapor at a constant temperature ranging between 1073 and 1273 K for 6 h. Titanium powder was recovered from the reduced preform by leaching it with acid. As a result, pure titanium powder with 99 mass% purity was obtained. This process was found to be suitable for producing a homogeneous fine powder when the composition of flux and the size of the preform are controlled.
Deoxidation of Titanium Using Mg as Deoxidant in MgCl2-YCl3 Flux Zheng, Chenyi; Ouchi, Takanari; Iizuka, Akihiro ...
Metallurgical and materials transactions. B, Process metallurgy and materials processing science,
15/4, Letnik:
50, Številka:
2
Journal Article
Recenzirano
To reduce the oxygen level in titanium (Ti) to less than 1000 mass ppm O, using magnesium as the deoxidant at 1300 K (1027 °C), the activity of the deoxidation product (MgO),
i.e.
,
a
MgO
, in the ...system must be reduced to less than 0.04, from a thermodynamic viewpoint. In this study, we developed a new deoxidation technique for Ti, by adding yttrium chloride (YCl
3
) to magnesium chloride (MgCl
2
) flux, which effectively decreases and maintains the
a
MgO
in the system at a low level,
via
the formation of yttrium oxychloride (YOCl). Through thermodynamic assessment using a
p
O
2
-
p
Cl
2
diagram, as well as experiments, the deoxidation of Ti to an oxygen level below 1000 mass ppm O,
via
the reaction O (in Ti) + Mg + YCl
3
→ MgCl
2
+ YOCl, was confirmed. Furthermore, using the
E
-pO
2−
diagram of the M-O-Cl system (M = Y, Mg), the possibility of electrochemical deoxidation is discussed. In the MgCl
2
-YCl
3
flux, Mg deposits on the Ti cathode and simultaneously deoxidizes it. The activity of the deoxidation product, MgO, decreases due to the formation of YOCl and/or the electrochemical oxidation of oxide ions on the carbon anode; thus, the deoxidation of Ti becomes feasible. This new deoxidation technique using rare-earth-containing MgCl
2
flux can be applied to the recycling of Ti scraps, in the future.
A new type of compact enhanced-bandwidth hybrid ring using an artificial lumped-element left-handed (LH) transmission-line (TL) section is proposed. The replacement of the 270/spl deg/ branch of the ...conventional hybrid ring by a -90/spl deg/ LH-TL branch results in both size reduction and bandwidth enhancement. The working principle of the LH TL used in the hybrid ring is explained and the performances of the component are demonstrated by measurement results. The proposed hybrid exhibits 67% size reduction compared to the conventional one, and shows a 58% and 49% bandwidth enhancements at 2 GHz in the 180/spl deg/-out-of-phase and in-phase operations, respectively.
We discuss exact multisoliton solutions of integrable hierarchies on noncommutative space–times in various dimensions. The solutions are represented by quasideterminants in compact forms. We study ...soliton scattering processes in the asymptotic region where the configurations can be real-valued. We find that the asymptotic configurations in the soliton scatterings can all be the same as commutative ones, i.e., the configuration of an N-soliton solution has N isolated localized lumps of energy, and each solitary wave-packet lump preserves its shape and velocity in the scattering process. The phase shifts are also the same as commutative ones. As new results, we present multisoliton solutions of the noncommutative anti-self-dual Yang–Mills hierarchy and discuss two-soliton scattering in detail.
Circulating tumour cells (CTCs) have an important role in metastatic processes, but details of their basic characteristics remain elusive. We hypothesised that CD44-expressing CTCs show a mesenchymal ...phenotype and high potential for survival in hepatocellular carcinoma (HCC).
Circulating CD44(+)CD90(+) cells, previously shown to be tumour-initiating cells, were sorted from human blood and their genetic characteristics were compared with those of tumour cells from primary tissues. The mechanism underlying the high survival potential of CD44-expressing cells in the circulatory system was investigated in vitro.
CD44(+)CD90(+) cells in the blood acquired epithelial-mesenchymal transition, and CD44 expression remarkably increased from the tissue to the blood. In Li7 and HLE cells, the CD44(high) population showed higher anoikis resistance and sphere-forming ability than did the CD44(low) population. This difference was found to be attributed to the upregulation of Twist1 and Akt signal in the CD44(high) population. Twist1 knockdown showed remarkable reduction in anoikis resistance, sphere formation, and Akt signal in HLE cells. In addition, mesenchymal markers and CD44s expression were downregulated in the Twist1 knockdown.
CD44s symbolises the acquisition of a mesenchymal phenotype regulating anchorage-independent capacity. CD44s-expressing tumour cells in peripheral blood are clinically important therapeutic targets in HCC.
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