In this Article dispersion characteristic of conventional optical waveguide with helical winding at core – cladding interface has been obtained. The model dispersion characteristics of optical waveguide with helical winding at core-cladding interface have been obtained for five different pitch angles. This paper includes dispersion characteristics of optical waveguide with helical winding, and ...

We present a quantum theory of a coherently pumped two-level atom in a photonic band gap ~PBG!, coupled to both a multimode waveguide channel and a high-quality microcavity embedded within a photonic crystal. One mode is engineered to exhibit a sharp cutoff within the PBG, leading to a large discontinuity in the local photon density of states near the atom, and the cavity field mode is resonant...

A recent study [1] has shown that a small discontinuity such as an enlargement or a hole on circular waveguides can produce trapped electromagnetic modes with frequencies slightly below the waveguide cutoff. The trapped modes due to multiple discontinuities can lead to high narrow-band contributions to the beam-chamber coupling impedance, especially when the wall conductivity is high enough. To...

Synopsis The yield-line method of analysis provides a powerful means of identifying the ultimate load carrying capacity of reinforced concrete slabs. Benefits of the yield-line method are that it will often identify additional reserves of strength when applied to the analysis of existing slabs, and to highly economic slabs when used in design. Traditionally a hand-based method, the yield-line m...

The transverse operator method is used for the analysis of an open-ended rectangular waveguide, in particular as a radiating element. It is shown that the method allows a systematic formulation of problems involving discontinuities whether they are radiating or not. The numerical results concerning the admittance and power patterns of a waveguide aperture surrounded by an infinite conducting fl...

A low cross-polarization slot array antenna in the narrow wall of ridge waveguide is presented. A non-angled slot which is created in the narrow wall of the ridge waveguide is considered to be used as radiating resonant slot. The normalized resistance and normalized reactance curves are presented for design purposes. A six element slot array waveguide antenna with ridges on its narrow wall is t...

The present work is about the synthesis of piano sound based on the grounds of physical principles. For that, rst the acoustical properties of the piano have to be understood, since the underlying physical phenomena establish the framework for the model-based sound synthesis. Therefore, the di erent parts of the piano were measured and analyzed. The groundwork of the piano model lies in the dig...

Instead of ‘researching’ for perfected (yet rejected) solutions, IMAG-DLO stresses the need for a farmer participatory approach towards: local development of less perfect, yet accepted practical and low-cost technologies; based on simple and durable equipment designs suitable for local manufacture.