Introduction Signal intensity uniformity in a magnetic resonance (MR) image indicates how well the MR imaging (MRI) system represents an object. One of the major sources of image non-uniformity in high-field MRI scanners is inhomogeneity of radio-frequency coil. The aim of this study was to investigate non-uniformity in head, head and neck, and body coils and compare the obtained results to det...

Aiming at the pulsation problem of traditional external grooved wheel fertilizer distributor, an opposed double spiral distributor is designed, and design analysis parameters are carried out. In order to obtain with best discharge effect, movement process particles in opposite was analyzed through discrete element simulation. Using combination simulation bench test, a orthogonal experiment out ...

The response uniformity of a 90]290 cm2 RPC prototype working in avalanche mode has been tested using cosmic rays. The high statistics needed for the test has also been used for accurate e$ciency studies. The intrinsic detector ine$ciency free, from spacers e!ects has been measured. ( 2000 Elsevier Science B.V. All rights reserved.

In this paper, we introduce new tests for exponentiality based on estimators of Renyi entropy of a continuous random variable. We first consider two transformations of the observations which turn the test of exponentiality into one of uniformity and use a corresponding test based on Renyi entropy. Critical values of the test statistics are computed by Monte Carlo simulations. Then, we compare p...

A detailed Computational Fluid Dynamics (CFD) and experimental investigation into characterizing the fluid flow and thermal profiles in a wind tunnel was carried out, highlighting the effect of progressive heating on the non-uniformity flow profile of air. Using controllable electrical heating elements, the operating temperatures in the test-section were gradually increased in order to determin...

An opto-electronic seed spacing evaluation system that measured time intervals between seeds and detected frontto-back location of seed drop events relative to the planter was used to rapidly determine planter seed spacing uniformity in the laboratory. The seed detection sensor for the opto-electronic system consisted of a rectangular photogate with 24 phototransistors receiving light beams fro...

OBJECTIVE To validate a method for determining the simvastatin content of compounded capsules, using high performance liquid chromatography. METHODS Eighteen samples of simvastatin 40 mg capsules from compounding pharmacies in the cities of São Paulo, Guarulhos, São Bernardo do Campo and Campinas, Southeastern Brazil, prescribed for fictitious patients were assessed. The analyses were based o...