Education and Economic Dominance

The paper examines the role of national education in achieving leading positions in global economic relations. Theoretical part uses stock of knowledge accumulated by scholars in the sphere related to human capital. Empirical part uses logistic regressions in order to test for relationship between global economic dominance and national education. Membership in the G20 is used in the models as a dependent categorical variable indicating the fact of the worldwide leadership. The models indicate that human capital and its educational part have statistically significant influence on the probability of becoming worldwide economic leader

The radiation history of material returned by the Soviet automatic stations Luna 16 and Luna 20, according to track studies

Fission tracks formed by the vH (very heavy) nuclei group of solar and galactic cosmic rays have been studied in silicate minerals of the lunar regolith returned by the Luna 16 and Luna 20 unmanned spacecraft. It is shown that the material in the Luna 16 core sample, from a typical mare region of the lunar surface, has undergone stronger irradiation by cosmic rays than material returned a highland region by Luna 20. A low-irradiation component (about 10 percent of the total number of crystals) has been found in the Luna 20 core sample materials, which can possibly be attributed to material added to the main bulk of the regolith in the formation of the crater Apollonius C. From the track density distribution of crystals, as a function of depth in the regolith core sample, it follows that the process of formation of the upper layer of the regolith, both for the lunar mare and for the highland region, includes sequential layering of finely crushed crystalline matter and subsequent mixing of it by micrometeorite bombardment. A portion of the crystals with a very high track density may be a component added to the lunar surface from outer space

Влияние имплантации титана на скорость сорбции водорода zr-2.5nb

Представлены результаты исследования влияния плазменно-иммерсионной ионнойимплантации титана на скорость сорбции Zr-2.5Nb. После имплантации титана снижаетсяконцентрация и скорость сорбции водорода, что связано с образованием диффузионного барьерного слоя, который снижает диффузию водорода в объем образца

Performance of Hydrogen Storage Tanks of Type IV in a Fire: Effect of the State of Charge

The use of hydrogen storage tanks at 100% of nominal working pressure (NWP) is expected only after refuelling. Driving between refuellings is characterised by the state of charge SoC <100%. There is experimental evidence that Type IV tanks tested in a fire at initial pressures below 1/3 NWP, leaked without rupture. This paper aims at understanding this phenomenon. The numerical research has demonstrated that the heat transfer from fire through the composite overwrap at storage pressures below NWP/3 is sufficient to melt the polymer liner. This melting initiates hydrogen microleaks through the composite before it loses the load-bearing ability. The fire-resistance rating (FRR) is defined as the time to rupture in a fire of a tank without or with blocked thermally activated pressure relief device. The dependence of a FRR on the SoC is demonstrated for the tanks with defined material properties and volumes in the range of 36–244 L. A composite wall thickness variation is shown to cause a safety issue by reducing the tank’s FRR and is suggested to be addressed by tank manufacturers and OEMs. The effect of a tank’s burst pressure ratio on the FRR is investigated. Thermal parameters of the composite wall, i.e., decomposition heat and temperatures, are shown in simulations of a tank failure in a fire to play an important role in its FRR