Large-scale (up to 100 kpc) H I structures have been found in three radio galaxies using the WSRT and the VLA. In one case, the H I has been detected in emission while in the other two H I absorption is detected against the radio lobes. In at least two of the three studied radio galaxies the H I appears to be distributed in a large disk and the large amount of neutral gas detected (> ∼ 10 M⊙) i...

In the present study, some perturbation methods are applied to Duffing equations having a displacement time-delayed variable to study the stability of such systems. Two approaches are considered to analyze Duffing oscillator having a strong delayed variable. The homotopy perturbation method is applied through the frequency analysis and nonlinear frequency is formulated as a function of all the ...

T/R switches, baluns and detuning elements are three major devices to reduce RF/EM couplings among receive RF coils, transmit RF coils and MRI system environment around RF coils in MRI system. Inadequate designs on these parts often lead to unnecessary high transmit power consumption, noisy NMR signal and the RF heating issues. In this paper we discuss the basic functions, theories and commonly...

This paper is devoted to the way point following motion task of a unicycle where the motion planning and the closed-loop motion realization stage are considered. The way point following task is determined by the user-defined sequence of waypoints which have to be passed by the unicycle with the assumed finite precision. This sequence will take the vehicle from the initial state to the target st...

We study the variation of word frequencies in Russian literary texts. Our findings indicate that the standard deviation of a word’s frequency across texts depends on its average frequency according to a power law with exponent 0.62, showing that the rarer words have a relatively larger degree of frequency volatility (i.e., “burstiness”). Several latent factors models have been estimated to inve...

We report the discovery of a new two-image gravitational lens candidate. The system RXJ0921+4529 contains two zs = 1.66 quasars separated by 6. 93 with an H band magnitude difference of ∆m = 1.39. The HST NIC2 H band images reveal an H=18.2 spiral galaxy between the quasar images, which is probably a member of a zl = 0.32 X-ray cluster centered on the field. We detect an extended source near th...

In the framework of the study of extragalactic radio sources, we will focus on the importance of the spatial resolution at different wavelengths, and of the combination of observations at different frequency bands. In particular, a substantial step forward in this field is now provided by the new generation X-ray telescopes which are able to image radio sources in between 0.1–10 keV with a spat...

The paper is devoted to the trajectory tracking control task for a differentiallydriven vehicle moving on a plane surface under conditions of the persistent skid-slip phenomena. The Vector Field(s) Orientation (VFO) control strategy, presented originally for undisturbed case in [6], has been reformulated here to the new disturbed motion conditions. The extension of the VFO strategy relies on in...

We present the results of 5-GHz observations with the VLA A-array of a sample of candidate Compact Steep Spectrum sources (CSSs) selected from the S4 survey. We also estimate the symmetry parameters of high-luminosity CSSs selected from different samples of radio sources, and compare these with the larger sources of similar luminosity to understand their evolution and the consistency of the CSS...