Long term Evolution of Earth Orbiting Debris

Long Term Evolution of Earth Orbiting Objects

The evolution of the orbiting debris population larger than 1 mm has been simulated for 100 yr assuming four diierent space policy scenarios. The study was made possible by the development of two speciic software codes, including the relevant source and sink mechanisms and several model options. A sensitivity analysis has shown that the results are relatively insensitive to the adoption of diie...

The Evolution of Long-term Care Programs; Comment on “Financing Long-term Care: Lessons From Japan”

The need for long-term care (LTC) represents a “new social risk,” one that overlaps with and complements systems of care that pre-date such programs, complicating LTC program design. This commentary expands on Ikegami’s discussion of how these structural factors must be accommodated, as well as historical and cultural factors that influence public expectations of such a...

Long Term Evolution of the Space Debris Population

In the last few years two diierent computer models have been developed in Pisa to study the evolution of the debris population. With them it is possible to simulate diierent scenarios for the future launch policies. We have deened a reference case which is a reasonable forecasting of the future space activities. Based upon it we have performed a number of simulations to study the innuence of th...

Analysis of the Earth Dams Function against the Effects of Long-Term Deposition in Reservoirs (Polrood Earth Dam-Guilan Province)

Estimation of sediment transport load due to erosion in river basins is one of the issues which is indispensable for many projects related to water resources, soil and damps construction. With regards to the phenomenon of erosion and transmission Sedimentation in rivers has always led to deformation in the seaboard and sedimentation, so the management and planning in bank of rivers is important...

Two Earth - sized planets orbiting