The main objective of this article is to present the semi-active vibration control using an electro-rheological fluid embedded sandwich structure for a cantilever beam. ER fluid is a smart material, which cause the suspended particles polarize and connect each other to form chain. The stiffness and damping coefficients of the ER fluid can be changed in 10 micro seconds; therefore, ERF is suitab...

To simulate the interaction of buried defects and absorber features in EUV masks and their effects on projection printing, a prototype 2D, fast, integrated, simulator based on ray tracing and a thin mask model is presented. RADICAL (Rapid Absorber Defect Interaction Computation for Advanced Lithography), consists of three sequential steps: the propagation of the mask illumination down through t...

We present spectroscopic observations of the damped Lyα absorber at redshift z = 1.9342 seen in the spectrum of the quasar Q0151+048A. The redshift of the absorber is greater than the redshift of the quasar, so the system resembles the zabs ≈ zem damped absorber at z = 2.81 towards the quasar PKS0528-250. We have previously reported the detection of Lyα emission from the latter absorber, one of...

We show that a fundamental feature of the three-level:two-level model, used to describe molecular monomode lasers with a saturable absorber, is the existence of isolas of periodic passive Q-switching (PQS) self-pulsations. A common feature of these closed families of periodic solutions is that they contain regions of stability of the PQS self-pulsation bordered by period-doubling and fold bifur...

In this paper, a compact plasmonic metamaterial absorber for terahertz frequencies is proposed and simulated. The absorber is based on metamaterial graphene structures, and benefits from dynamically controllable properties of graphene. Through patterning graphene layers, plasmonic resonances are tailored to provide a dual band as well as an improved bandwidth absorption. Unit cell of the design...

The first X-ray observation of the Seyfert 2 galaxy NGC5252 is reported. ASCA collected ∼ 4000 photons/detector enough to perform an accurate spectral analysis of this source. The luminosity of NGC5252 is L X (0.7-10 keV) ≃ 2.6 ×10 43 erg s −1 , typical of a Seyfert 1 galaxy. A simple description of the spectrum with a single power law is ruled out by the SIS data which shows a strong soft exce...

Current solar to thermal energy conversion technologies, including concentrated solar power (CSP) and solar water heaters (SWH) utilize absorber surfaces that collect incident solar radiation. However, these absorber surfaces emit thermal energy (at their temperature) in the infrared (IR) spectrum, resulting in decreased overall efficiency for solar-to-thermal conversion. Selective absorber sur...

A thin electromagnetic band-gap (EBG) absorber is employed to capture the 2-d image of radio-frequency (RF) power distribution. The EBG absorber consists of an array of mushroom unit cells formed on a thin dielectric substrate with a metal backplane, and lumped resistors interconnecting the surface patches of the mushrooms. Around the resonance frequency at which the EBG structure acts as a hig...

Vibro-impact (VI) based control strategies exploit non-linear phenomena occurring during impacts between oscillating masses and vibrating structures to mitigate vibrations. They are known be effective on a wide frequency range, in harsh environnement, they eco-friendly comparison some visco-elastic polymers used for the same application. Different assumptions emerge explain energy dissipation s...