In the radio communications industry, one major problem is the vibration induced on to a frequency standard. The most commonly used frequency standard is the crystal oscillator; as the crystal oscillator gets vibrated with varying force and frequencies of vibration the phase noise of the signal changes. As the phase noise increases, the signal to noise ratio decreases causing the likelihood of ...

In this paper, the superior mid-frequency vibration isolation of a geometrically optimized lightweight structure is demonstrated. The initial structure under test here was a 4.5m long satellite boom consisting of 10 identical bays with equilateral triangular cross-sections. An unusual geometric variant of this, with inherent isolation characteristics, has been designed by the use of genetic alg...

Due to limitations on the use of passive base isolation systems which show poor performance in near field seismic excitations or active systems which require high external power, as stand alone control devices for a range of seismic excitations, a hybrid control system that mitigates the limitations of either passive or active control systems is preferred. The present study examines the use of ...

Anopheles gambiae, responsible for the majority of malaria deaths annually, is a complex of seven species and several chromosomal/molecular forms. The complexity of malaria epidemiology and control is due in part to An. gambiae's remarkable genetic plasticity, enabling its adaptation to a range of human-influenced habitats. This leads to rapid ecological speciation when reproductive isolation m...

Vibration attenuation to horizontal propagating waves by using periodic foundations is investigation. Periodic structure theory is introduced to design a new type of isolation foundations, which has a special frequency band gaps (or ‘attenuation zones’) that can barrier waves/vibrations propagation. Materials usually used in civil engineering are used to fabric periodic foundations with the uni...