Influence Of Pressure Waves Research Articles

The influence of pressure waves in tidal gravity records

For the reduction of atmospheric effects, observed gravity has initially been corrected by using the computed barometric admittance k of the in situ measured pressure, expressed in nms−2/hPa units and estimated by least squares method. However, the local pressure changes alone cannot account for the atmospheric mass attraction and loading when the coherent pressure field exceeds a specific size, i.e., with increasing periodicities. To overcome this difficulty, it is necessary to compute the total atmospheric effect at each station using the global pressure field. However, the direct subtraction of the total gravity effect, provided by the models of pressure correction, is not yet satisfactory for S2 and other tidal components, such as K2 and P1, which include solar heating pressure tides. This paper identifies the origin of the problem and presents strategies to obtain a satisfactory solution.First, we set up a difference vector between the tidal factors of M2 and S2 after correction of the pressure and ocean tides effects. This vector, hereafter denoted as RES, presents the advantage of being practically insensitive to calibration errors. The minimum discrepancy between the tidal parameters of M2 and S2 corresponds to the minimum of the RES vector norm d.Secondly we adopt the hybrid pressure correction method, separating the local and the global pressure contribution of the models and replacing the local contribution by the pressure measured at the station multiplied by an admittance kATM.We tested this procedure on 8 stations from the IGETS superconducting gravimeters network (former GGP network). For stations at an altitude lower than 1000 m, the value of dopt is always smaller than 0.0005. The discrepancy between the tidal parameters of the M2 and S2 waves is always lower than 0.05% on the amplitude factors and 0.025° on the phases. For these stations, a correlation exists between the altitude and the value kopt. The results at the three Central European stations Conrad, Pecny and Vienna are in excellent agreement (0.05%) with the DDW99NH model for all the main tidal waves.

Global Solar Variations and Effects of Relativistic 2D-Hydrogen

Characteristics of the temporal evolution of the global solar magnetic field were found to display a 2-step cycling mode consistent with a pattern of a fundamental harmonic progression underlying all solar cycles at all times and having its seat in the fusion region of the core via nuclear magnetic resonance as part of the hydrogen and helium fusion chain. In addition to the three principal zones in the interior of the sun, core, radiative zone, and convection zone, a sub-surface layer is being suggested to take part in the processes of varying solar activity, which would be an extension of relativistic 2D hydrogen being formed throughout the plasma body under the influence of pressure waves originating in the core. The major participants confined to such a 2D layer is for the most part 2D hydrogen particularly in its form of relativistic 2D hydrogen, where the Bohratom binding energies are replaced by binding energies in the range of Eo = 0.5 MeV. For this reason it is conjectured that this condition lends itself to providing contributions to (a) the energy release including 0.5 MeV and lower energy γ-photons as well as (b) superimposing a radial component to the global dipole field.

312 キャビテーション気泡流れと圧力波を用いた水処理システムの基礎的研究(水環境保全・改善技術(3))

This paper describes the fundamental investigations for developing new technology using cavitation bubbles, microbubbles and pressure waves. The absorbance change of the aqueous solution of methylene blue was examined to quantify water treatment efficiency. Also, influence of cavitation bubbles and micro bubbles on the efficiency of methylene blue were examined. In addition, the influence of pressure waves on cavitation bubbles was investigated. As the result, it was found that (1) the efficiency was decreased by adding microbubbles to cavitation bubbles, (2) the efficiency in the cavitation flow depends on the quantity of cavitation bubbles, (3) by working pressure waves on cavitation flow, the collapsing pressure becomes larger, and the frequency of collapsing bubbles becomes higher.

Influence of pressure waves on the initial development of an explosion kernel

The paper discusses the role of pressure waves in the propagation of deflagrations immediately after ignition. The effect of one-dimensional pressure interactions upon the mass burning rate of a planar flame is first of all discussed, whereby it is shown that there can be a large transient effect on the mass flux through the flame at different locations in the reaction zone. The paper then goes on to discuss two-dimensional effects, in particular the baroclinic production of vorticity leading to the eventual breakup of a laminar flame into a series of turbulent flamelets.