most of the earth's crust contains fluids, and fractures are common throughout the upper part. they exist at a wide range of scales from micro-fractures within grains to major faults and shear zones that traverse the crust. in this paper, the stress-dependent permeability in fractured rock masses have been investigated considering the effects of nonlinear normal deformation and shear dilation o...

in this paper a new low profile substrate integrated waveguide (siw) probe-fed h-plane horn antenna structure with improved gain is proposed. the proposed antenna consists of two waveguides including a rectangular and a taper one, in which both, first and third modes of the structure are simultaneously excited leading to a uniform field distribution along the radiating aperture of the antenna a...

Horn antennas can result in good impedance matching between the waveguide and free space due to the gradual increase in the aperture size. In this paper, a novel plasmonic sectoral horn nanoantenna based on using lens in the aperture is proposed. It is investigated that in addition to improvement of the directivity, the reflection coefficient is also reduced using the proper lens structure. The...

We have proposed a new ultra-compact optical demultiplexer based on metal-insulator-metal plasmonic waveguides aperture-coupled to the ring resonators. Our proposed device has high performance, small footprint, and high potential for integration and development to more channels.

Fluid flow in jointed rock mass with impermeable matrix is often controlled by joint properties, including aperture, orientation, spacing, persistence and etc. On the other hand, since the rock mass is made of heterogeneous and anisotropic natural materials, geometric properties of joints may have dispersed values. One of the most powerful methods for simulation of stochastic nature of geometri...

A very-small-aperture laser (VSAL) with a circular aperture has a trade-off between the spot size and the output power. A nanometric annular aperture is fabricated to overcome this difficulty. The advantages of the annular aperture are demonstrated by measuring and comparing its near-field intensity distribution with that of a circular aperture. These apertures are fabricated on the same VSAL t...

The dipole impedance of an aperture in a plane conductor is obtained by modifying the general network formulation of electromagnetic apertures presented by Mautz and Harrington. The derived dipole impedances are combined in parallel to form an effective circuit description of low frequency aperture diffraction. Power transmitted into the aperture by an incident wave is determined by incorporati...

analysis of aperture-coupled microstrip antennas with a superstrate using space domain closed form greens functions is presented. integral equations are derived from applying the boundary conditions on the radiating patch, across the aperture, and on the microstrip feedline. the computation of space domain greens functions is performed using the closed-form. the solution of the integral equatio...