The flow at the leading edge and in the interior of a rectangular porous obstruction is described through experiments and scaling. The porous obstruction consists of an emergent, rectangular array of cylinders in shallow flow, a configuration that mimics aquatic vegetation. The main features of the flow depend upon the non-dimensional canopy flow-blockage, which is a function of the obstruction...

Nowadays, functionally graded materials (FGM) are widely used in many industrial, aerospace and military fields. On the other hand, the interest in the use of shrink-fitted assemblies is increasing for designing composite tubes, high-pressure vessels, rectors and tanks. Although extensive researches exist on thick-walled cylindrical shells, not many researches have been done on shrink-fitted th...

Tissue arrays can evaluate molecular targets in high numbers of samples in parallel. Array construction presents technical difficulties and tissue arrayers are expensive, particularly for small and medium sized laboratories. This report describes a method for the construction of 36 sample arrays using widely available materials. A blunted 16 gauge needle for bone marrow aspiration was used to e...

In this paper, we study the operation of electrostatically actuated electromechanical resonators having fractal electrodes. Using the spring-mass model, we establish the scaling relationships for pull-in instability , voltage dependent resonance frequency 1 , and pull-in voltage , where is the fractal dimension of the electrode, is the air-gap, and are the resonance frequency at zero and applie...

Under the assumption of linear wave theory, a semi-analytical model is developed to address time-dependent water scattering problem involving marine structure consisting several circular rigid vertical cylinders, each which surrounded by thin cylindrical porous wall with region between inner cylinder and wall. The tackled applying eigenfunction expansion approach. energy dissipation relation al...

There is an increased use of fiber reinforced polymer composites (FRPC) in a wide area of engineering fields for various reasons including, ease of transportation and installation, high strength to weight ratio and favorable durability in different conditions. On the other hand, the use of this material as confining shells has been an interesting matter for retrofit, strengthening and construct...

We argue that the presence of dissociated ions in block copolymers under electric fields can induce strong morphological changes and even lead to phase transitions. We investigate, in particular, diblock copolymers in the body centered cubic (bcc) phase. In pure dielectric materials (no free charges), a dielectric breakdown is expected to occur for large enough electric fields, preempting any s...

An investigation is made into water-wave propagation through a doubly-periodic array of vertical cylinders extending to infinity in both horizontal directions. Methods are presented for the calculation of the frequency ranges for which wave propagation without change of amplitude is possible (‘passing bands’), and for which propagation without change of amplitude is not possible (‘stopping band...

It is shown that Bound States in the Continuum (BSC) exist an elastic structure consisting of a periodic double array thin (subwavelength) cylindrical scatterers embedded background material, where distance between arrays taken to be large comparison both wavelength and period array. The medium supports waves with all polarizations, one longitudinal two transverse, each which has different phas...