Diffusion Tensor MRI (DTI) of the human heart in vivo has to date been performed in 2D and at a single phase of the cardiac cycle. Here we perform 3D tractography of the human heart in vivo at both end diastole and end systole. We show that fiber orientation in the subepicardium becomes more oblique during systole, and that scalar indices of diffusion (mean diffusivity and fractional anisotropy...

We describe an arrangement for simultaneous recording of speech and geometry of vocal tract in patients undergoing surgery involving this area. Experimental design is considered from an articulatory phonetic point of view. The speech and noise signals are recorded with an acousticelectrical arrangement. The vocal tract is simultaneously imaged with MRI. A MATLAB-based system controls the timing...

Quantitative nanoindentation of nominally 7.5 and 600 μm tall vertically aligned carbon nanotube (VACNT) arrays is observed in situ within an SEM chamber. The 7.5 μm array consists of highly aligned and weakly interacting CNTs and deflects similarly to classically defined cylindrical columns, with deformation geometry and critical buckling force well estimated using the Euler-Bernoulli theory. ...

Interdigitated microelectrodes have found wide applications in manipulating and/or separating biological particles due to their simple structure and easy implementation. Particle behaviors in such interdigitated microelectrode devices are affected by a number of factors, including particle size, electrical potential, chamber geometry and dielectric properties. This paper presents systematical s...

Transition rates were obtained from spectra for pure metallic samples of atomic number ranging from 22 to 27, measured with monochromatic incident X-ray beams from a synchrotron source. The experimental setup for this consisted of an energy dispersive spectrometer in a conventional 45–45 geometry, mounted in an evacuated chamber. Absorption, detector efficiency and multiple scattering were take...

The paper presents results of determination of sound source localization based on signals measured by first-order ambisonic microphone. The experiment consisted in recording the test signals with the 3D microphone positioned in the axis of the turntable in the anechoic chamber. The spherical coordinates of the sound intensity vector were calculated and compared to actual values resulting from t...

LXeGRIT – Liquid Xenon Gamma-Ray Imaging Telescope – is the first prototype of a Compton telescope for MeV γ-ray astrophysics based on a LXe time projection chamber. One of the most relevant figures of merit for a Compton telescope is the detection efficiency for γ-rays, which depends on diverse contributions such as detector geometry and passive materials, trigger efficiency, dead time, etc. A...

introduction: well type ionization chamber is a measuring device which is used to determine the activity of brachytherapy sources. the chamber has a cylindrical volume in which a cylindrical tube is mounted in the middle of the chamber. for the measurements, the brachytherapy sources are transferred to the middle of the tube. materials and methods: for designing the well type chamber, the measu...

This paper presents localized and temporal control of release kinetics over 3-dimensional (3D) hybrid wound devices to improve wound-healing process. Imaging study is performed to extract wound bed geometry in 3D. Non-Uniform Rational B-Splines (NURBS) based surface lofting is applied to generate functionally graded regions. Diffusion-based release kinetics model is developed to predict time-ba...

We study a uniform flow in a parallel plate geometry to model contaminant transport through a saturated porous medium in a semi-infinite domain in order to simulate an experimental apparatus mainly constituted by a chamber filled with a glass beads bed. The general solution of the advection dispersion equation in a porous medium was obtained by utilizing the Jacobi θ3 Function. The analytical s...