We suggest and demonstrate the concept and design of sectional asymmetric structures which can manipulate the metamaterial absorber's working bandwidth with maintaining the other inherent advantages. As an example, a broadband terahertz perfect absorber is designed to confirm its effectiveness. The absorber's each cell integrates four sectional asymmetric rings, and the entire structure compose...

A large area and broadband ultra-black absorber based on microstructured aluminum (Al) doped silicon (Si) films prepared by a low-cost but very effective approach is presented. The average absorption of the absorber is greater than 99% within the wide range from 350 nm to 2000 nm, and its size reaches to 6 inches. We investigate the fabrication mechanism of the absorber and find that the Al ato...

The Compact Linear Fresnel Reflector (CLFR) is a linear-concentrating solar thermal energy system currently in the prototype stage at the Liddell power station in the Hunter Valley, NSW. A system-level thermo-fluidic model for the CLFR has been developed in order to predict steady-state operating conditions, required pumping power and pressure, mass transfer around the system and likely startup...

We have used X-ray spectra to measure attenuating columns in a large sample of Seyfert galaxies. Over 30 of these sources have resolved radio jets, allowing the relative orientation of the nucleus and host galaxy to be constrained. We have discovered that the distribution of absorbing columns is strongly correlated with the relative orientation of the Seyfert structures. This result is inconsis...

X-ray spectroscopy of Seyfert 1 galaxies often reveal absorption edges resulting from photoionized gas along the line-of-sight to the central engine, the so-called warm absorber. I discuss how recent ASCA observations of warm absorber variability in MCG?6-30-15 can lead us to reject a one-zone model and, instead, have suggested a multi-zone warm absorber. The evidence for dust within the warm a...

We describe the optical characterisation of two silicon cold-electron bolometers each consisting of a small (32 × 14 μm) island of degenerately doped siliconwith superconducting aluminium contacts. Radiation is coupled into the silicon absorber with a twin-slot antenna designed to couple to 160-GHz radiation through a silicon lens. Thefirst device has a highly doped silicon absorber, the second...

The present work deals with the theoretical study on heat transfer characteristics and the performance of a cylindrical parabolic solar water heater with twisted tape inserted inside the absorber tube. The absorber tube equipped with twisted tape with six different twist ratios 5, 6, 7, 8, 9 and 10. The theoretical work is conducted in a turbulent flow regime and considering water as a working ...

A novel active electromagnetic vibration absorber (AEMVA) is developed. It is shown that for suppression of steady-state response to a harmonic excitation, a proportional and derivative feedback control is equivalent to a time-delayed control. The study of the stability issue focuses on a conflicting goal of achieving the marginal stability of the time-delayed vibration absorber and the stabili...

The Cu(In,Ga)(S,Se)(2)Mo interface in thin-film solar cells has been investigated by surface-sensitive photoelectron spectroscopy, bulk-sensitive x-ray emission spectroscopy, and atomic force microscopy. It is possible to access this deeply buried interface by using a suitable lift-off technique, which allows us to investigate the back side of the absorber layer as well as the front side of the...

in this work an improved method for designing a linear vibrational absorber, excited by random vibrations is presented and analyzed. first, analytical expressions, for non-stationary white noise accelerations, are derived. the criterion is different from the conventional criteria, used for structural design under random vibration, and it is based on minimum displacement or acceleration response...