Design and Simulation of an Electrically Pumped SPASER

In this investigation, a novel SPASER is designed and simulated which uses a forward biased pn junction to induce population inversion condition. Simulations are performed by means of SILVACO software. In the proposed structure, the active region is considered as a direct bandgap material (InGaAs) and a larger bandgap material (InP) is used for p and n regions to form heterojunctions. This pn junction is in contact with gold and surface plasmons propagate along their interface. Free space wavelength of the oscillations of surface plasmons is 1550nm that is used in photonic devices, frequently. To form the resonance cavity of the SPASER, two high reflective mirrors are placed at the ends of the plasmonic waveguide. Applied forward voltage and absorption coefficient of the SPASER are 1.2V and − 0.33cm− 1, respectively. Thus, the optical gain for a 50 microns cavity length is 1cm− 1. Moreover, the power consumption of the proposed device at these conditions is 1.2mW. The output plasmonic power is 0.6mW which yields 50% power efficiency.

Wind-Tunnel Simulation of Stable Atmospheric Boundary Layers with an Overlying Inversion

Four cases of an overlying inversion imposed on a stable boundary layer are investigated, extending the earlier work of Hancock and Hayden (Boundary-Layer Meteorol 168:29–57, 2018), where no inversion was imposed. The inversion is imposed to one or other of two depths within the layer: midway or deep. Four cases of changed surface condition are also investigated, and it is seen that the surface and imposed conditions behave independently. A change of imposed inversion condition leaves the bottom 1/3 of the layer almost completely unaffected; a change of the surface condition leaves the top 2/3 unaffected. Comparisons are made against two sets of local-scaling systems over the full height of the boundary layer. Both show some influence of the inversion condition. The surface heat flux and the reduction in surface shear stress, and hence the ratio of the boundary-layer height to surface Obukhov length, are determined by the temperature difference across the surface layer (not the whole layer), bringing all cases together in single correlations as functions of a surface-layer bulk Richardson number.

Natural Images Contour Segmentation

This paper, a combination of edge detection and contour based segmentation approach for object contour delineation is proposed. The proposed approach employs a new methodology for segmenting the fruit contour from the indoor and outdoo r natural images more effectively. The overall process is carried out in five steps. The first step is to pre - process the image in order to convert the colour image to grayscale image. Second step is the adoption of Laplacian of Gaussian edge detection and a new corner template detection algorithm for adjustment of the pixels along the edge map in the interpolation process. Third step is the reconstruction process by implementing two morphology operators with embedded of inversion condition and dynamic thr eshold to preserve and reconstruct object contour. Fifth step is ground mask process in which the outputs of the inference obtained for each pixel is combined to a final segmented output, which provides a segmented foreground against the black background. This proposed algorithm is tested over 150 indoor and 40 outdoor fruit images in order to analyse its efficiency. From the experimental results, it has been observed that the proposed segmentation approach provides better segmentation accuracy of 100 % in segmenting indoor and outdoor natural images. This algorithm also present a fully automatic model based system for segmenting fruit images of the natural environment.

Verification of Theoretical Model for Tunneling Currents in Al/SiO2/p-Si MOS Capacitors with Nanometer-Thick Oxides

The verification of calculation results of the isotropic and anisotropic-isotropic mass models in Al/SiO2/Si MOS capacitor against the experimental data is presented, using electron transversal velocity as a fitting parameter. In the accumulation condition, the comparison yields the electron velocity of 2.8 x 106m/s for both isotropic and isotropic-anisotropic mass models. The tunneling current values for both models are slighly different with experimental data. In the inversion condition, the values of electron velocity for isotropic and isotropic-anisotropic model are 1.55 x 106m/s and 1 x 105m/s, respectively. The calculation results of isotropic-anisotropic mass model appear to be closer to the experimental data compared to those of isotropic mass model, due to the effect of electron effective mass.

Forefoot Plantar Pressure Distribution Character during Inversion Position

This study analyzed the plantar pressure distribution character as the foot position between normal to inversion. Eight healthy male volunteers have participated in the test with the foot position from normal to 20 inversion angles which controlled by wedges. The results of this test showed that the centre of the pressure was clearly transferred from centre to lateral side when the foot position was changed from normal to inversion. In addition, the contact area varied largely between the normal and inversion condition, but changed a little between two inversion loading situations. The finding of this study suggests that the foot injuries could attributed to more of inappropriate foot positioning than the magnitude of loading force.