Chien-Tien Hsu

Efficient adaptive phase field simulation of dendritic growth in a forced flow at low supercooling

Abstract Efficient phase field simulation using an adaptive finite volume method is presented for two-dimensional dendritic growth in a forced flow. The extremely large domain (over 2 18 in the ratio of cell size), while keeping very small cell size at the interface, makes the simulation at low supercooling possible. With a strong forced flow, the upstream tip speed reaches a steady state quickly even at low supercooling. The upstream arm develops side branches easily, but remains similar after rescaling, i.e., self-affine, as the diffusive one at steady state.

Engineering silicon crystals for photovoltaics

Silicon has remained the material of choice for both the microelectronic and photovoltaic (PV) industries for a few decades. In addition to its abundance, silicon can be refined to an extremely high purity and grown into large dislocation-free single crystals that meet the stringent requirements of modern electronic devices for many applications. On the other hand, customized silicon crystals with lower purity and perfectness, grown via high-throughput directional solidification at a low cost, that can meet the high performance needs of solar cells have rapidly driven PV development in the past decade. In this highlight, we review the recent engineering efforts in the state-of-the art industrial production of customized silicon crystals, including quasi-mono and multi-crystalline silicon (mc-Si). Special attention will be focused on the so-called high-performance (HP) mc-Si that has become the mainstream material for solar cells since 2012.

Studies on abruptio placentae

Abstract 1. The incidence of abruptio placentae at Provincial Taipei Hospital is 2.09 per cent of the total deliveries and that in Taipei City is 0.16 per cent. 2. In our small series a high incidence of afibrinogenemia was seen (62.5 per cent). 3. Elderly grand multiparas with toxemia or chronic hypertensive vascular disease are predisposed to abruptio placentae and should be placed under special prenatal supervision. 4. Coagulation defects in our series were characterized by thrombocytopenia, deficiency of Ac-globulin, prolonged prothrombin time, prolonged bleeding and coagulation times, hypo-, or afibrinogenemia, and the rarity of appearance of fibrinolysin and fibrinogenolysin. 5. Transfusions of fresh blood effected a rise in the fibrinogen level, without the use of supplementary fibrinogen. 6. It is important to terminate the labor as quickly as possible when the fibrinogen level is elevated above the critical level. 7. Paper electrophoresis of the plasma in cases of suspected afibrinogenemia is a rapid and simple tool for the diagnosis of this condition.