The acoustic properties of a periodic rigid frame porous layer with multiple irregularities in the rigid backing and embedded rigid circular inclusions are investigated theoretically and numerically. The theoretical representation of the sound field in the structure is obtained using a combination of multipole method that accounts for the periodic inclusions and multi-modal method that accounts...

Curcumin, the active molecule present in Curcuma longa is known for its antitumour, antioxidant, antiarthritic, anti-amyloid, anti-ischemic, anti-inflammatory activities. In addition, it may also be effective in treating malaria, prevention of cervical cancer, etc. High-performance thin-layer chromatography (HPTLC) method has been employed for determination of curcumin in four varieties of turm...

SUMMARY Behavior of a poroelastic material bonded onto a vibrating plate is investigated in the low frequency range. From the analysis of dissipation mechanisms, a model accounting for damping added by the porous layer on the plate is derived. This analysis is based on a 3-D finite element formulation including poroelastic elements based on Biot displacement theory. First, dissipated powers rel...

The design of a simple, robust, low-cost, and bidirectional displacement sensor with subangstrom resolution is described. A small gold plate is attached to the object, whose displacement is to be measured, and a small gold tip is brought into contact with the plate, establishing a reference current between the two. Movements of the gold plate away from the tip lead to a change in the tip-plate ...

An analytical expression for the voltage measured by a four-point alternating current potential drop (ACPD) method on a flat metal surface is derived. Far-field expressions for the electric field in a metal plate and in the region of the probe (air) are used to obtain contributions to the ACPD voltage from the metal plate and due to inductance in the pick-up circuit. The far-field approximation...

Solar drying technology has been widely used in engineering fields such us chemical because of its low cost and pollution advantages. In this review, the structural forms, materials coatings heat-absorbing panels flat plate solar air collector are classified, experimental theoretical results performance level panel summarized. indoor tests, energy efficiency is 30% to 79%, applications 28% 62%.