نتایج جستجو برای: silver pinhole

تعداد نتایج: 47177  

Journal: :British Dental Journal 2003

Journal: :Analytical chemistry 2014
Francesco Paolo Romano Claudia Caliri Luigi Cosentino Santo Gammino Lorenzo Giuntini David Mascali Lorenzo Neri Lighea Pappalardo Francesca Rizzo Francesco Taccetti

This work describes a tabletop (50 cm × 25 cm × 25 cm) full field X-ray pinhole camera (FF-XPC) presenting high energy- and high spatial-resolution. The FF-XPC consists of a conventional charge-coupled device (CCD) detector coupled, in a coaxial geometry, to a pinhole collimator of small diameter. The X-ray fluorescence (XRF) is induced on the samples with an external low-power X-ray tube. The ...

Journal: :Physics in medicine and biology 2009
Marc A N Korevaar Jan W T Heemskerk Freek J Beekman

The performance of pinhole single photon emission computed tomography (SPECT) depends on the spatial resolution of the gamma-ray detectors used. Pinhole cameras suffer from strong resolution loss due to the varying depth-of-interaction (DOI) of gamma quanta that enter the detector material at an angle. We eliminate DOI effects in a scintillation gamma camera via a dedicated optic fiber bundle t...

2013
M. J. Ayers S. R. Nagel B. Felker P. M. Bell D. K. Bradley K. Piston J. Parker Z. Lamb J. D. Kilkenny T. J. Hilsabeck T. Chung J. D. Hares A. K. L. Dymoke-Bradshaw

Gated X-Ray imagers have been used on many ICF experiments around the world for time resolved imaging of the target implosions. DIXI (Dilation X-ray Imager) is a new fixed base diagnostic that has been developed for use in the National Ignition Facility. The DIXI diagnostic utilizes pulse-dilation technology [1,2,3,4] and uses a high magnification pinhole imaging system to project images onto t...

2015
Trent Koessler Harold Hill

A hollow (concave) mask appears convex when viewed from beyond a certain distance even when viewed stereoscopically-this is the hollow-face illusion. At close viewing distances, the same mask is seen as hollow even when disparity information is eliminated by monocular viewing. A potential source of nonpictorial, monocular information that favors a veridical percept at close distances is accommo...

Journal: :Journal of biomedical optics 2004
Krishnakumar Venkateswaran Austin Roorda Fernando Romero-Borja

We present axial resolution calculated using a mathematical model of the adaptive optics scanning laser ophthalmoscope (AOSLO). The peak intensity and the width of the axial intensity response are computed with the residual Zernike coefficients after the aberrations are corrected using adaptive optics for eight subjects and compared with the axial resolution of a diffraction-limited eye. The AO...

2008
Thomas Carlier Aurore Oudoux Eric Mirallié Alain Seret Isabelle Daumy Christophe Leux Caroline Bodet-Milin Françoise Kraeber-Bodéré Catherine Ansquer

Purpose A pinhole collimator is routinely used to increase the resolution of scintigraphy. This prospective study was conducted to determine the interest of Tc-MIBI pinhole SPECT for the preoperative localization of parathyroid lesions in primary hyperparathyroidism. Methods All patients underwent a neck US, TcO4 and Tc-MIBI planar images, and two consecutive SPECT with a parallel (C-SPECT) and...

2016
X. Gu D. F. R. Mildner

Small-angle neutron scattering (SANS) measurements from thin sections of rock samples such as shales demand as great a scattering vector range as possible because the pores cover a wide range of sizes. The limitation of the scattering vector range for pinhole SANS requires slit-smeared ultra-SANS (USANS) measurements that need to be converted to pinhole geometry. The desmearing algorithm is onl...

1999
Chi Wu Ke-Qing Xia

A new differential refractometer, which mainly consists of a laser light source, a position-sensitive detector, and a temperature-controlled refractometer cuvette has recently been developed. In comparison with a conventional differential refractometer, it has a different optical design so that the effect of laser beam drift can be greatly reduced. In our design, a very small pinhole is illumin...

Journal: :Journal of nuclear medicine : official publication, Society of Nuclear Medicine 1981
J L Ritchie D L Williams J H Caldwell J R Stratton G D Harp R A Vogel G W Hamilton

Thirty-six patients with prior myocardial infarction, and 14 patients without, had myocardial imaging at rest using both seven-pinhole emission tomography and planar imaging with thallium-201. The sensitivity and specificity of the two approaches for the detection of prior myocardial infarction were compared. Qualitatively, planar imaging yielded sensitivities of 69% (25 of 36) and 80% (29 of 3...

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