The flow enthalpy of an arc-heated wind tunnel is an important parameter for reproducing planetary entry and performing heating tests. However, its distribution is insufficiently clarified owing to complicated phenomena, such as arc discharge and supersonic expansion. In this study, we assess the enthalpy of an arc-heated flow in a large-scale facility based on measurements and computational results. The flow enthalpy of high-temperature gases, which comprised thermal, chemical, kinetic, and pressure components, was reconstructed based on the measured rotational temperature, heat flux, and impact pressure, in addition to the computational science approach. The rotational temperature of nitric oxide molecules was obtained using emission spectroscopic measurements of band spectra in the near-ultraviolet range. A numerical model was developed and validated based on measured data. The results indicated that the model efficiently reproduced the arc discharge behavior in the heating section and the thermochemical non-equilibrium in the expansion section. It was discovered that the dominant components of the arc-heated flow in the test section were the chemical and kinetic components. The flow enthalpy exhibited a non-uniform distribution in the radial direction. We conclude that the flow enthalpy of the core is approximately 28 MJ/kg at the nozzle exit.
To elucidate the role of recombinant human colony-stimulating factors (CSFs) for expanding peripheral blood (PB) CD34+ cells, these cells were purified up to 94.5% +/- 1.3% and the effects of individual and combined CSFs on the proliferation and differentiation of these cells were studied in a 7-day suspension culture. The majority of CD34+ cells coexpressed CD38 (81.8% +/- 5.1%), but was negative for CD33 (88.5% +/- 3.4%). Among the individual CSFs examined, recombinant interleukin-3 (rIL-3) was identified as the most potent factor for expanding PB progenitor cells and increased nonerythroid progenitor cells 13- +/- 4- fold (P < .01). Recombinant granulocyte-macrophage colony-stimulating factor (rGM-CSF), recombinant granulocyte-CSF (rG-CSF), recombinant macrophage-CSF (rM-CSF), rIL-6, rIL-11, and recombinant stem cell factor (rSCF) did not alone expand nonerythroid progenitor cells. A combination of 5 CSFs, ie, rIL-3, rIL-6, rGM-CSF, rG-CSF, and rSCF, was identified as the most potent combination of those tested and increased nonerythroid progenitor cells 57- +/- 11-fold. After a 7-day suspension culture of CD34+ cells with these 5 CSFs, CD34+ cells expanded 14.5- fold, and CD34+/CD33- cells and CD34+/CD33+ cells were also expanded 2.9-fold and 307-fold, respectively. Most secondary colonies derived from expanded cells were small; however, the absolute number of large- sized colonies expanded 5.9- +/- 3.3-fold. Thus, the combination of CSFs can achieve a degree of amplification of PB CD34+ cells. The capability of in vitro expansion of PB CD34+ cells as an adjunct to PB stem cell transplantation is worthy of consideration.
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