Choked accretion onto Kerr-Sen black holes in Einstein-Maxwell-Dilation-Axion gravity

We study the choked accretion process of an ultrarelativistic fluid onto axisymmetric Kerr-Sen black holes in Einstein-Maxwell-Dilation-Axion theory. We calculate the solution describing the velocity potential $\Phi$ of a stationary, irrotational fluid, which satisfies the stiff equation of state and draw the streamlined diagram of the quadrupolar flow solution. We investigate how parameters affect the solution's coefficient and stagnation point. The injection rate, ejection rate, and critical angle are discussed in detail at the end of the article. If the inner and outer event horizons of the black hole are satisfied, then we can find that the ratio of the ejection rate to the setting rate increases with an increase in the dilation parameter.Comment: 25pages,10 figure

Electrocardiogram Baseline Wander Suppression Based on the Combination of Morphological and Wavelet Transformation Based Filtering

One of the major noise components in electrocardiogram (ECG) is the baseline wander (BW). Effective methods for suppressing BW include the wavelet-based (WT) and the mathematical morphological filtering-based (MMF)algorithms. However, the T waveform distortions introduced by the WTand the rectangular/trapezoidal distortions introduced by MMF degrade the quality of the output signal. Hence, in this study, we introduce a method by combining the MMF and WTto overcome the shortcomings of both existing methods. To demonstrate the effectiveness of the proposed method, artificial ECG signals containing a clinicalBW are used for numerical simulation, and we also create a realistic model of baseline wander to compare the proposed method with other state-of-the-art methods commonly used in the literature. /e results show that the BW suppression effect of the proposed method is better than that of the others. Also, the new method is capable of preserving the outline of the BW and avoiding waveform distortions caused by the morphology filter, thereby obtaining an enhanced quality of ECG

Research on Injected Effect and Heat-transfer Characteristics of Narrow-Slit Injection Orifice Used for the Screw Compressor

A narrow-slit injection orifice which is used for the screw compressor injection is described in this paper. Different from the traditional injection orifice, the orifice is slit shaped but not circular. Liquid which is injected by the narrow-slit injection orifice appears as a curtain shape so that the heat transfer area is increased. The cooling effect is enhanced and then the efficiency of the compressor is improved. The injected velocity of the orifice is simulated through the CFD software, and then the experiments are carried out. The study verified the accuracy of the simulation results. It will provide a theoretical foundation for the design of the narrow-slit injection orifice used for the screw compressor