A plasma processing apparatus wherein a layer structure consisting of plural layers formed in stack one upon another on a semiconductor wafer placed on the sample holder located in the process chamber, is etched with plasma generated in the process chamber by supplying high frequency power to the electrode disposed in the sample holder, the apparatus comprising a ring-shaped electrode disposed above the electrode and around the periphery of the top portion of the sample holder, an outer circumferential ring of dielectric material disposed above the ring-shaped electrode and opposite to the plasma, and a power source for supplying power at different values to the ring-shaped electrode depending on the sorts of layers of the layer structure.

Plasma Processing Apparatus

A low temperature molten salt process is developed to prepare crystalline Si nanoparticles through the reduction of micro-sized high silicon zeolite by metallic Al (or Mg) in molten AlCl3. The reaction can be initiated at 200 °C, and the yield is about 40%. As the reaction temperature increases to 250 °C, the yield can reach about 75%. When the prepared Si was used as an anode for Li-ion batteries, reversible capacities of 2663 mA h g−1 at 0.5 A g−1 after 50 cycles and 870 mA h g−1 at 3 A g−1 after 1000 cycles can be obtained. Similarly, this synthetic strategy is employed to synthesize Si nanoparticles starting from various abundant raw materials including SiO2 powder, kieselguhr, fiberglass, and even the natural mineral of albite.

A low temperature molten salt process for aluminothermic reduction of silicon oxides to crystalline Si for Li-ion batteries

Three-dimensional fluid flow in continuous casting tundishes with and without flow control devices is first studied. The results indicate that flow control devices are effective to control the strong stirring energy within the inlet zone, and other zones are with much uniform streamline. By dividing tundish into two zones with different inclusion removal mechanisms the inclusion removal is calculated. Three modes of inclusion removal from molten steel in the tundish, i.e., flotation to the free surface, collision and coalescence of inclusions to form larger ones, and adhesion to the lining solid surfaces, are taken into account. The Brownian collision, Stokes collision, and turbulent collision are examined and discussed. The suitable coagulation coefficient is discussed, and a value of 0.18 is derived. Calculation results indicate that, besides flotation, collision of inclusion and adhesion to the lining solid surfaces are also important ways for inclusion removal from molten steel in tundish especially for the smaller inclusions. The flotation removal holds 49.5 pct, and the adhesion removal holds 29.5 pct for the tundish with flow control devices; the collision effect is reflected in improving flotation and adhesion. Finally, industrial experiment data are used to verify the inclusion removal model.

Fluid flow and inclusion removal in continuous casting tundish

http://arc.nucapt.northwestern.edu/refbase/files/Balch-2006.pdf

Load partitioning in aluminum syntactic foams containing ceramic microspheres

The evolution of structural order, microstructure and mineral matter of metallurgical coke in a blast furnace: A review

Model experiments on the particle coagulation in NaCl-aqueous solutions were made in an agitated vessel to learn the coagulation rate of inclusion particles in liquid steel. Polystyrene-latex particles, silica particles and alumina particles were tested at various agitation speeds, and coagulation coefficients were obtained by comparing the observed coagulation rate with the predicted rate by the Saffman-Turner model on turbulent collision. The Higashitani theory which considered the effect of van der Waals force and viscous resistance force on the coagulation coefficient was applied to obtain the Hamaker constant from the measured coefficients. Based on the measured Hamaker constants, the coagulation coefficients of inclusion particles in liquid steel were predicted for several steelmaking processes with different stirring intensities.

Model Experiment on the Coagulation of Inclusion Particles in Liquid Steel

実が急がれねばな らない. 溶鋼中介在物に関する研究は溶鋼 の脱酸 に端 を発 して いる.こ れまで脱酸に関する多 くの速度論的研究が行 わ れ1)2),脱酸反応 の律速段階 は脱酸生成物の凝集・分離 過 程にある とみなされるに至 っている.し か し,溶 鉄系に おける介在物凝集 につ いては実験の 困難 さが障害 とな り,メ カニズムまで立ち入った詳細 な研究 は少 ないのが 現状 である.一 方,他 分野 に目を転ずれば,流 体 中の微 小粒子の凝集に関 してはコロイ ド化学やエアロゾル工学 の分野で多 くの優れた研究 が蓄積 されている.ま た流体 中の粒子挙動 については流体力学の分野において盛 んに 研究が行 われている.さ らに近年で は,粒 子間の界面化 学的相互作用および流体力学 的相互作用の両者 を考慮 し た,凝 集 に関する厳密 な取扱 いも見 られるよ うになって いる.こ れらの研究成果の中には介在物凝集の解析 に十

Mechanisms of Collision and Coagulation between Fine Particles in Fluid

An aluminum/Al2O3 composite body is produced by a displacement reaction between SiO2 and molten aluminum. The growth rate of the reaction layer possesses negative (anomalous) temperature dependence at 1000–1300 K. This study compared reported reaction-kinetic data and investigated causes for this temperature dependence. The reaction product, Al2O3, changed from the γ-/θ-Al2O3 phase to the α-Al2O3 phase in this temperature range and α-Al2O3 became the dominant phase at >1273 K. Isothermal transformation of the γ-/θ-Al2O3 product phases to the α-Al2O3 phase was also observed. Morphologies and scales of the Al2O3 phases change drastically at 1173 K; this transition occurred in a spatially discontinuous manner. Reaction-rate retardation was interpreted in terms of occurrence of the competitive and simultaneous reactions to produce different Al2O3 phases in this temperature range. It was also found that the hydrogen release from the raw SiO2 and the SiO2 phase transformation were not related to the negative temperature dependence.

Anomalous Temperature Dependence of the Growth Rate of the Reaction Layer between Silica and Molten Aluminum

/pdf/dispersion-of-bubbles-and-gas-liquid-mass-transfer-in-a-gas-1xa0c9qgqh.pdf

Dispersion of bubbles and gas-liquid mass transfer in a gas-stirred system.

https://www.cfd.com.au/cfd_conf99/papers/033TANI.PDF

Atsushi Kikuchi

Papers

Model Experiment on the Coagulation of Inclusion Particles in Liquid Steel

Mechanisms of Collision and Coagulation between Fine Particles in Fluid

Anomalous Temperature Dependence of the Growth Rate of the Reaction Layer between Silica and Molten Aluminum

Dispersion of bubbles and gas-liquid mass transfer in a gas-stirred system.

Fluid flow and gas–liquid mass transfer in gas-injected vessels