In the present paper , dynamic characteristics of the pressure pulsation and heat exchange have been analyzed in cooler of reciprocating compressor. Through the analysis of energy balance for an heat exchange element , the differential equations are established for the heat exchange element. Effect of the pressure pulsation on heat exchange has been considered in the cooler of the compressor by...

The characteristics of substorm-associated Pi2 pulsations observed by the SABRE coherent radar system during three separate case studies are presented. The SABRE field of view is well positioned to observe the differences between the auroral zone pulsation signature and that observed at mid-latitudes. During the first case study the SABRE field of view is initially in the eastward electrojet, e...

Pulsation in β Cep and SPB stars are driven by the κ mechanism which depends critically on the metallicity. It has therefore been suggested that β Cep and SPB stars should be rare in the Magellanic Clouds which have lower metallicities than the solar neighborhood. To test this prediction we have observed the open SMC cluster NGC 371 for 12 nights in order to search for β Cep and SPB stars. Surp...

A model for the adiabatical pulsation of a Cepheid based on primary physical principles such as energy conservation, mechanical adiabaticity and hydrostatic equilibrium is presented. The adiabatical treatment of the pulsation has been already studied by other authors but the novelty of our model is that it allows to obtain physical parameters of the star, namely the amplitude of the oscillation...

It is suggested that a moving canonical particle interacts with a vacuum regarded as a ”soft” cellular space. The interaction results into the emergence of elementary excitations of space – inertons – surrounding the particle. It is assumed that such a motion leads not only to the spatial oscillation of the particle along a path but to the oscillation of the particle centre-of-mass as well. Thi...

Context. PG 1159-035, a pre-white dwarf with Teff ≃ 140 000 K, is the prototype of both two classes: the PG 1159 spectroscopic class and the DOV pulsating class. Previous studies of PG 1159-035 photometric data obtained with the Whole Earth Telescope (WET) showed a rich frequency spectrum allowing the identification of 122 pulsation modes. Analyzing the periods of pulsation, it is possible to m...

The effect of pulsation on the heat transfer rates, for turbulent water stream with upstream pulsation of different amplitudes, in a double-pipe heat exchanger for both parallel and counter flows, with cold water on the shell side, was investigated. Pulsation frequencies, with using a reciprocating device, ranged up to 260 cycles per minute (up to 4.3 Hz) and 5 different displacement amplitudes...

Pressure pulsation, created by the operation of hydraulic pumps in a fluid power system, is one of the primary causes of noise issues from hydraulic machinery. The wave energy resulting from such pulsation propagates in both the wall and the fluid of the flow pipes associated with the fluid power systems, inducing fluid borne vibration of the pipes and the consequent noise radiated from the pip...

The long-term observations of the Galactic Centre as well as the Galactic anti-Centre regions in hard X-rays (10-300 keV) were made in experiments on board Prognoz-9 satellite and ”Mir” orbital station (GRIF experiment). Some transient pulsars including A0535+262, GS1722-36, 4U1145-619, A1118615, EXO2030+37, Sct X-1, SAX J2103.5+4545, IGR 16320-4751, IGR 164654507 were observed. The pulsation f...