Bulk properties of open cell polyurethane foam are studied in a hydrostatic compression experiment under strain control. A linear region of behaviour is observed in the stress-strain curve, followed by a non-monotonic region corresponding to a negative incremental bulk modulus. The bulk modulus in the linear region is in reasonable agreement with the value calculated from compressional Young’s ...

A novel type of circularly polarized broadband antenna consisting of a modified circular wideslot aperture and an L-shaped feed probe is introduced. The modified circular wide-slot is partially covered to generate circular polarization with broadband characteristics in the axial ratio. Variations in both the axial ratio and the S11 characteristics of the device are investigated and radiation pa...

Based on computational fluid dynamics, friction lubrication theory and hydrostatic technology, large size hydrostatic Guide-way of heavy vertical CNC lathes,which are widely used, was taken as research object. The control equation of hydrostatic guide-way’s interstitial fluid was established. By finite volume method, lubricating oil properties, boundary conditions such as constant flow inlet, o...

Photonic Crystal Fibers, optical fibers with regular structure of micro-holes running along the axial direction, have ability to change their optical properties through inserting different materials into their holes. The paper presents our latest experimental results of the influence of external electric field and hydrostatic pressure on propagation properties of the photonic crystal fibers inf...

This paper presents an element of a 2×2-element array antenna for Inmarsat BGAN/GPS applications. The element is an axial mode printed quadrifilar helical antenna that has been integrated with a compact feed network to provide sequential phase rotation for circular polarization (CP) radiation. The novel integrated lumped-element feed network is designed to provide a balanced RF power to the fou...

The design and application of a patented active actuator design that combines the radial and axial actuator into one combination radial-axial actuator is presented. The theory of operation of the actuator is defined and magnetic finite element analysis modeling shown verifying operation. Its mechanical construction is then presented to show how this actuator configuration is successfully integr...