introduction: good radiographs are required for endodontic therapy and because some patient’s are intolerant to intraoral films and/or sensors, this can cause complications in endodontic treatment. extraoral film placement can be used to obtain clinically diagnostic and working radiographs. materials and methods: the no. 2 receptor was placed against the model ’ s cheek and centered in the mola...

We comment on a recent article (Gomà et al 2014 Phys. Med. Biol. 59 4961-71) which compares different routes of reference dosimetry for the energy dependent beam monitor calibration in scanned proton beams. In this article, a 3% discrepancy is reported between a Faraday cup and a plane-parallel ionization chamber in the experimental determination of the number of protons per monitor unit. It is...

The purpose of this study is to calculate correction factors for plastic water (PW) and plastic water diagnostic-therapy (PWDT) phantoms in clinical photon and electron beam dosimetry using the EGSnrc Monte Carlo code system. A water-to-plastic ionization conversion factor k(pl) for PW and PWDT was computed for several commonly used Farmer-type ionization chambers with different wall materials ...

The purpose of this study was to investigate the effect of dose perturbations for two metallic spinal screw implants in proton beam therapy in the perpendicular and parallel beam geometry. A 5.5 mm (diameter) by 45 mm (length) stainless steel (SS) screw and a 5.5 mm by 35 mm titanium (Ti) screw commonly used for spinal fixation were CT-scanned in a hybrid phantom of water and solid water. The C...

OBJECTIVE We compare the mitral valve annular dimension in relation to the body surface area of the Indian population as against the standard values. METHODS The study was conducted between September 2004 and February 2006 on 406 subjects, out of which 252 were males and 154 were females. A spatially oriented B-mode scan echocardiogram was used, with the long-axis plane running parallel to th...

We study numerically the reconfiguration process of colliding m=1/2 strength disclinations in an achiral nematic liquid crystal (NLC). A Landau–de Gennes approach terms tensor nematic-order parameters is used. Initially, different pairs m1,m2 parallel wedge disclination lines connecting opposite substrates confining NLC a plane-parallel cell thickness h are imposed: {1/2,1/2}, {−1/2,−1/2} and {...