Background: The use of lasers has become increasingly common in the field of medicine and dentistry, and there is a growing need for a deeper understanding of the procedure and its effects on tissue. The aim of this study was to compare the erbium-doped yttrium aluminium garnet (Er:YAG) laser and conventional drilling techniques, by observing the effects on trabecular bone microarchitecture and...

The effect of porosity on the elastic behavior of cast steel is investigated experimentally, and an approach for including porosity effects in finite element analysis (FEA) simulations is presented. Porous cast steel specimens are mechanically tested having apparent elastic moduli reduced between 17 and 61 pct. Analysis of radiographs and tomography is used to measure and reconstruct the porosi...

Numerical simulations are performed to investigate the interaction of acoustic waves with an array of equally-spaced two-dimensional micro-cavities on an otherwise flat plate without external boundary-layer flow. This acoustic scattering problem is important in the design of ultrasonic absorptive coatings (UAC) for hypersonic laminar flow control. The reflection coefficient, characterizing the ...

We investigated the cluster-size distribution of the residual nonwetting phase in a sintered glass-bead porous medium at two-phase flow conditions, by means of micro-computed-tomography (μCT) imaging with pore-scale resolution. Cluster-size distribution functions and cluster volumes were obtained by image analysis for a range of injected pore volumes under both imbibition and drainage condition...

Canopy gaps are small-scale openings in forest canopies which offer suitable micro-climatic conditions for tree regeneration. Field mapping of gaps is complex and time-consuming. Several studies have used Canopy Height Models (CHM) derived from airborne laser scanning (ALS) to delineate gaps but limited accuracy assessment has been carried out, especially regarding the gap geometry. In this stu...

The problem of the reduced dielectric response in thin films of high-permittivity materials is analyzed by studying the soft-mode response in several SrTiO3 thin films by means of Fourier transform far infrared, monochromatic submillimeter, and micro-Raman spectroscopies. A 300-nm-thick metalorganic chemical vapor deposition film, quasiepitaxially grown on a ~0001! sapphire substrate with a per...

Extremely low permeability due to nano-scale pores is a distinctive feature of gas transport in a shale matrix. The permeability of shale depends on pore pressure, porosity, pore throat size and gas type. The pore network model is a practical way to explain the macro flow behavior of porous media from a microscopic point of view. In this research, gas flow in a shale matrix is simulated using a...

A two-dimensional computer code, using a multi-material Eulerian finite element formulation, was used to investigate the dynamic micromechanical behavior of granular material. The main results are : The strain-rate insensitive material model provides the correct increase in the dissipated energy with an increase of shock pressure ; An increase in the initial porosity or the pressure results in ...