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Ultrasonic wave propagation in human cancellous bone is considered. Reflection and transmission coefficients are derived for a slab of cancellous bone having an elastic frame using Biot's theory modified by the model of Johnson et al. [J. Fluid Mech. 176, 379-402 (1987)] for viscous exchange between fluid and structure. Numerical simulations of transmitted(More)
Chlorophyll a fluorescence (ChlF) and leaf morphology were assessed in two sites in Europe (Kaltenborn, Germany, and Satakunta, Finland) within a forest diversity experiment. Trees at Satakunta, planted in 1999, form a stratified canopy, while in Kaltenborn the trees are 7 years old, with no apparent canopy connection among broadleaf species. The following(More)
An ultrasonic reflectivity method is proposed for measuring porosity and tortuosity of porous materials having a rigid frame. Porosity is the relative fraction by volume of the air contained within a material. Tortuosity is a geometrical parameter which intervenes in the description of the inertial effects between the fluid filled the porous material and(More)
An ultrasonic reflectivity method of evaluating the acoustic parameters of porous materials saturated by air (or any other gas) is discussed. The method is based on experimental detection of waves reflected at normal incidence by the first and second interface of the material. This method is based on a temporal model of direct and inverse scattering(More)
In the present work, we describe an anodization process that is able to fully transform a thin Ti metal layer on a conductive glass into a TiO(2) nanotubular array. Under optimized conditions, nanotube electrodes can be obtained that are completely transparent and defect-free and allow electrochromic switching. These electrochromic electrodes show(More)
The formation of nanotubes on titanium is compared for anodizing under controlled voltage and controlled current in a fluoride/glycerol electrolyte. Rutherford backscattering spectroscopy and nuclear reaction analysis are employed to determine the film compositions. Film morphologies are examined by electron microscopy. The findings reveal films of(More)
A new concept of a composite dielectric thin film fabrication is presented. The fabrication process consists of two stages. The first stage is anodizing a thin aluminum film to produce a porous alumina film that contains an array of nanometer sized parallel pores. The second stage is filling the pores with a saturated KDP (KH2PO4) liquid solution due to(More)
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