We present Giant Metrewave Radio Telescope (GMRT) HI 21cm emission images of the z = 0.009 damped Lyman-α (DLA) absorber towards the QSO HS 1543+5921. The DLA has been earlier identified as a low surface brightness galaxy SBS 1543+593 (Reimers & Hagen 1998, Bowen et al. 2001a) with small (∼ 400 pc) impact parameter to the QSO line of sight. The extremely low redshift of the absorber allows us t...

Coupled oscillators play an important role in many scientific fields, for example, in mechanics, electronics, and biology; see [1, 4] and references therein. In this paper we analyze two coupled oscillators, one of which is driven by an external periodic force. Important example of such a system is a dynamic vibration absorber which consists of a small mass, m2, attached to the primary vibratin...

Using a 100 ks XMM-Newton exposure of the well studied, low black hole mass (MBH = 1.9× 10 M⊙) Narrow Line Seyfert 1 NGC 4051, we show that the time evolution of the ionization state of the X-ray absorbers in response to the rapid and highly variable X-ray continuum constrains all the main physical and geometrical properties of an AGN Warm Absorber wind. We use a technique that takes advantage ...

In this paper, the possible realization of the electromagnetic (EM) absorber as a thin metasurface is considered. The metasurface is based on establishing a passive surface of electric and magnetic currents using the Huygen’s principle. So, the absorber is named Huygens Absorber (HA). The metasurface can be designed using split meander lines with spiral rings. In this way, both sides of the sub...

Micro-perforated absorber is a newly developed sound absorber, and it has a number of attractive features: • Unlike conventional perforated absorbers, micro-perforated absorber can be made from transparent materials like plastic glass. • Unlike commonly used fibrous absorptive materials, micro-perforated absorber is fibrous-free and thus, there is no health concern. • Micro-perforated membranes...

A broadband Circuit Analogue (CA) absorber using double-circular-loop array is investigated in this paper. A simple equivalent circuit model is presented to accurately analyze this CA absorber. The circuit simulation of the proposed model agrees well with full-wave simulations. Optimization based the equivalent circuit model, is applied to design a single-layer circuit analogue absorber using d...

We investigate the dynamics of the vertically forced Duffing oscillator with suspended tuned mass absorber. Three different types of tuned mass absorbers are taken into consideration, i.e., classical single pendulum, dual pendulum and pendulum-spring. We numerically adjust parameters of absorbers to obtain the best damping properties with the lowest mass of attached system. The modification of ...

As novel absorber materials are developed and screened for their photovoltaic (PV) properties, the challenge remains to reproducibly test promising candidates for high-performing PV devices. Many early-stage devices are prone to device shunting due to pinholes in the absorber layer, producing "false-negative" results. Here, we demonstrate a device engineering solution toward a robust device arc...