35 research outputs found
Silicon solar cell with cover glass bonded to cell by metal pattern Patent
Metal pattern bonding technique for cover glass attachment to silicon solar cells for space application
Gd or Sm doped silicon semiconductor composition Patent
Gadolinium or samarium doped-silicon semiconductor material with resistance to radiation damage for use in solar cell
Method of making a silicon semiconductor device Patent
Doping silicon material with gadolinium to increase radiation resistance of solar cell
Effects of impurities on radiation damage of silicon solar cells
Impurities effects on radiation damage of silicon solar cell
Radiation-Resistant Solar Cells - A Panel Discussion
Radiation resistant silicon cells for solar energy conversio
Correlation for Sessile Drop Evaporation Over a Wide Range of Drop Volatilities, Ambient Gases and Pressures
A correlation for the evaporation of sessile drops over a very broad range of conditions was developed based on measured evaporation rate data obtained for drops of acetone, methanol, and six hydrocarbons ranging from hexane to isooctane, evaporating in air, helium, argon, and krypton, over a range of ambient pressures from 96 kPa to 615 kPa. The experiments were designed to produce a large variation in the rates of diffusion and buoyancy-induced (natural) convection of the vapor phase amongst the experimental conditions. The correlation, which fits the measurements with an RMS relative error of 5.2%, is a simple equation involving conventional parameters for diffusive and convective transport and is applicable to conditions for which vapor transport limits the rate of evaporation. Application of the correlation requires knowledge of eight basic properties: the ambient pressure and temperature, the equilibrium vapor pressure of the evaporating component, the diffusion coefficient for the evaporating component in the ambient gas, the viscosity of the ambient gas, the radius of the sessile drop, and the molecular weights of the evaporating component and the ambient gas. The correlation is much easier to implement than a computational model based on the coupled conservation equations of mass, energy, and momentum for the two phases, and it offers a single mathematical expression that provides valuable insight into how the roles of diffusive and convective transport change with physical and geometrical parameters. The correlation can be a valuable tool to aid in the analyses of applications involving sessile drop evaporation and to support the validation of complex computational models.
The range of experimental conditions resulted in a large variation in the rates of diffusive and naturally convective transport of the vapor. Over the range of experimental conditions, the liquid volatility, as indicated by the equilibrium vapor pressure, was varied by a factor of 16.7, the mass diffusivity by a factor of 52.2, the density difference ratio (the impetus for natural convection) by a factor of 3,557, and the drop radius by a factor of 22. In terms of the Rayleigh number, the experimental data covers a range from 5 to 361,000. Consequently, the correlation is applicable to a very broad range of conditions. To our knowledge these evaporation rate measurements of sessile drops in gases other than air and at pressures above one atmosphere are the first to be reported in the literature
The major acid-soluble proteins of Bacillus subtilis spores: partial amino acid sequence and forespore location of their mRNAs
In Bacillus subtilis the alpha, beta, gamma and delta components comprise 80-90% of the total acid-soluble spore proteins (ASSPs). Sequence analysis demonstrates that alpha and beta share 32 of their first 36 amino acids and are closely related to the A and C ASSPs of Bacillus megaterium spores, confirming the results of analysis of their cloned genes. Despite the difference in apparent size of gamma and delta, they have identical N-terminal sequences (37 residues). Unless gamma and delta derive from very recently duplicated genes, it appears that gamma is derived from delta, either in vivo or during isolation. Although the sequenced regions of gamma and delta have no homology to alpha and beta, outside of the previously recognized pentapeptide recognition sequence for the spore endopeptidase, they share 10 and 15 residue peptides flanking this sequence with ASSP B of B. megaterium, but in reverse order. At least two groups of ASSPs have, therefore, been conserved between B. subtilis and B. megaterium: the multigene AC alpha beta family and the B gamma (delta) group. Sequence conservation in each group implies selection for functions in addition to storage. Both the alpha and beta components of B. subtilis ASSPs and their mRNAs are located in the forespore compartment of cells at t5.5 of sporulation, the time of most rapid ASSP synthesis. The sizes of these transcripts (250-350 bp) and their ability to direct the in vitro synthesis of ASSPs of mature size, indicate that genes for these ASSPs are monocistronic, consistent with dispersed map location. Synthesis of ASSPs is, therefore, coordinately controlled by selective transcription in the forespore