Comparison of A1-absorption data with theoretically computed values based on the International Reference Ionosphere (IRI)

Total absorption of hf radio waves at vertical incidence is calculated using the IRI electron density N(h) profiles at a low latitude for low and high solar activities and the calculated values of absorption are compared with the observed values. It is found that the IRI model holds good in this respect only for equinoxial months in years of low solar acitvity; however, it yields much higher values of absorption than observed during years of high solar activity (all seasons). It is suggested that seasonal anomalous variations of gas composition and bottomside thickness of the E-layer may be given due weight in revising the IRI.     

Atmospheric electrical conductivity measurements and modeling for application to air pollution studies

The experimentally measured ground level atmospheric electrical conductivity is validated from a simplified ion–aerosol model for which the inputs are ionization rate from surface radioactivity, aerosol density and meteorological parameters. Also estimated from the model is the reduction in conductivity for assumed aerosol levels. It is seen that for an increase of ambient aerosols by threefold the percent reduction in conductivity is 7% and it is 10% for an increase by sixfold. Thus, the variations in the measured ground level conductivity can be used to examine the atmospheric pollution, if any.     

Military qualification of a high-reliability, light-weight 24 V/30Ah aircraft battery

The United States Navy has flown Valve Regulated Lead-Acid Batteries (VRLA) for approximately 18 years. The first VRLA aircraft batteries were cylindrical cell design and evolved to a prismatic design to save weight, volume, and to increase rate capability. This paper discusses the next generation of the VRLA aircraft battery. The HORIZON composite grid VRLA design reduces weight, increases high rate performance, and is expected to increase service life. This paper discusses the weight reduction over the present 30 Ah prismatic VRLA aircraft battery design; improvements in high rate engine start performance, and present status of the development effort. Finally, the paper discusses the applications for the 30 Ah composite grid VRLA aircraft battery, and shows the future application opportunities for light-weight VRLA, both in the military and commercially