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Full-Text Articles in Physical Sciences and Mathematics
Low Resolution Hi Imaging Of The Shield Galaxies, Masao L. Miazzo
Low Resolution Hi Imaging Of The Shield Galaxies, Masao L. Miazzo
Macalester Journal of Physics and Astronomy
We present low-resolution Karl G. Jansky Very Large Array D-configuration HI spectral line observations of 32 previously unobserved local-volume low-mass dwarf galaxies in the Survey of HI in Extremely Low-mass Dwarfs (SHIELD). SHIELD was designed to probe the physical characteristics of the objects that inhabit the faint end of the HI mass function as populated by the ALFALFA blind HI extragalactic survey. These low angular-resolution images localize the HI-gas and provide the first glimpse of the neutral interstellar medium in these sources. We quantify the total HI mass of each system, and, using SDSS imaging, we compare the HI and …
Actinometry Of Hydrogen Plasmas, A. M. Cotter, James Doyle
Actinometry Of Hydrogen Plasmas, A. M. Cotter, James Doyle
Macalester Journal of Physics and Astronomy
Optical emission spectroscopy (OES) can be used to map the electron energy distribution of hydrogen plasmas. Using actinometry, a type of OES where trace amounts of noble gases are introduced, the effect of discharge power on the electron temperature of hydrogen plasmas was explored. This was done using argon and krypton as actinometers for low pressure hydrogen plasmas. It was determined that the electron temperature decreased with respect to power supplied to the discharge.
Modeling Recombination In Solar Cells, Paul Chery
Modeling Recombination In Solar Cells, Paul Chery
Macalester Journal of Physics and Astronomy
Solar cells are a competitive alternative to nonrenewable energy sources such as fossil fuels. However, the efficiency of these devices is limited by photogenerated carrier recombination. We use a finite difference numerical model to study recombination phenomena in the absorber layer of solar cells including alternate recombination models and the effects of spatial distribution of recombination centers. We compare the effect of using the constant lifetime approximation for recombination to the full Shockley-Read-Hall expression in Silicon solar cells and find that the constant lifetime approximation holds for high defect densities but not for high photon flux densities. Finally, we simulate …