research and developmentexpenditure (r&d;) in new literature plays an important role in economic growth. investment in r&d;, increases level of knowledge and enhanced knowledge, increase production efficiency and from efficiency channel economic growth improves. many studies have been done on the r&d; not used unit of data for this variable. this is due to a lack of labor and the level of inves...

Abstract Only few design guidelines for side channel compressors are published in open literature. Among those the most common ones from Grabow, Surek, and Raheel. In this publication we focus on guideline of which includes, among several analytical equations, two empirical estimates head coefficient blade angle. These lead to an uncertainty process could potentially effect performance curve ma...

A traveling wave analysis for a quantum hydrodynamic model ist performed. The isobaric, isentropic and isothermal cases are studied. In all three cases the qualitative behaviour of the solutions is analysed.

After a review of the isentropic compressible magnetohydrodynamics (ICMHD) equations, a quaternionic framework for studying the alignment dynamics of a general fluid flow is explained and applied to the ICMHD equations.

We give a complete description of nonlinear waves and their pairwise interactions in isentropic gas dynamics. Our analysis includes rarefactions, compressions and shock waves. Because the waves are arbitrarily large, we describe the change of states across the wave exactly, without resolving the characteristic patterns. We similarly describe the states between nonlinear waves in any pairwise in...

The dynamical equations of atmospheric flow are written using potential vorticity as the meridional coordinate and potential temperature as the vertical coordinate. Within this system, the atmosphere is divided into undulating tubes bounded by isentropic and constant potential vorticity surfaces, and, under adiabatic and frictionless conditions, the air moves through the tubes without penetrati...

Gas wave ejector (GWE) is an efficient ejection equipment using pressure waves to extract and transfer energy. However, at present, GWE designed only for single condition, not fully utilizing the production capacity. The collaborative mode one work simultaneously under two different conditions was proposed resolve this issue in study, analyzed by combining numerical simulation experimental test...

The Allam cycle is a novel that capitalizes on the unique thermodynamic properties of supercritical CO2 and advantages oxy-fuel combustion for power generation capture. This study aims to confirm outstanding performance coal-fired with aid an exergetic analysis provide detailed important information real inefficiencies within cycle. results show overall efficiency 40.6%, near 100% carbon highes...