Hollow-core photonic crystal fibres have excited interest as potential ultra-low loss telecommunications fibres because light propagates mainly in air instead of solid glass. We propose that the ultimate limit to the attenuation of such fibres is determined by surface roughness due to frozenin capillary waves. This is confirmed by measurements of the surface roughness in a HC-PCF, the angular d...

The sensitivity of an innovative micromachined acoustic sensor consisting of four hot-wires is analyzed theoretically and experimentally. An analytical model is presented that describes both the air flow and the temperature profile in and around the probe. The presence of the chip surface in the vicinity of the wires influences the acoustic flow, while also affecting the temperature distributi...

Direct drive wind turbine generators are gaining importance for light weight, compact design in wind power generation. A new design approach of superconducting wind generator having both axial and radial air gaps between stator and superconducting rotor winding is selected for this simulation work. This paper deals with the simulation of magnetic flux distribution in stator and rotor coil of th...

multiple coupled circuit modeling of squirrel-cage induction motors, or winding function approach is the most detailed and complete analytical model used to analyze the performance of the faulty induction motors. this paper extends the above-mentioned model to a saturable model including variable degrees of the saturation effects using an appropriate air gap function and novel techniques for lo...

We demonstrate the Fourier relationship between angular position and angular momentum for a light mode. In particular we measure the distribution of orbital angular momentum states of light that has passed through an aperture and verify that the orbital angular momentum distribution is given by the complex Fourier-transform of the aperture function. We use spatial light modulators, configured a...

the most important environmental pollutant in steel industry is air pollution due to the process of its products. optimise sitting for this industry, in a great extend will prevent pollutants and emissions. khorasan steel company is located near some populous villages and three rivers. it is necessary to perform an investigation for providing abatement and control of air pollution, in time of p...

concerns have been raised about the adverse impact of dusty air pollution (dap) on human health. the aim of this study was to find the association between dusty air pollution based on air quality index (aqi) and the risk of allergic diseases in southwestern provinces of iran, with assessing cytokine profiles and lymphocyte immunophenotypes.in this case control study 148 individuals participated...

A problem of density matrix determination in terms of the given angular distribution of decay products is considered. In the first part of this paper (Section III) a quantum system, described by density matrix, has been considered. In this the density matrix was diagonal with respect to orbital quantum numbers and the state was mixed only partially. Now we will consider the process X → 0 + 0, w...

We investigate the focusing properties of a femtosecond vortex light pulse focused by a high numerical aperture objective. By using the Richards-Wolf vectorial diffraction method, the intensity distribution, the velocity variation and the orbital angular momentum near the focus are studied in great detail. We have discovered that the femtosecond vortex light pulse can travel at various speeds, ...