introduction: the selection of suitable beam angles and weights in external-beam radiotherapy is at present generally based upon the experience of the planner. therefore, automated selection of beam angles and weights in forward-planned radiotherapy will be beneficial. material and methods: in this work, an efficient method is presented within the matlab environment to investigate how to improv...

UNLABELLED The use of convergent-beam SPECT can increase detection sensitivity; however, the projection data are likely to be truncated if the patient is not properly positioned. This article describes a patient-positioning method that has been adopted in our hospital for cardiac SPECT scans when convergent-beam collimators are used. METHODS The system that we use has 3 detector heads and a p...

Most small-animal X-ray computed tomography (CT) scanners are based on cone-beam geometry with a flat-panel detector orbiting in a circular trajectory. Image reconstruction in these systems is usually performed by approximate methods based on the algorithm proposed by Feldkamp et al. (FDK). Besides the implementation of the reconstruction algorithm itself, in order to design a real system it is...

Our institution established a new treatment facility for carbon ion beam scanning therapy in 2010. The major advantages of scanning beam treatment compared to the passive beam treatment are the following: high dose conformation with less excessive dose to the normal tissues, no bolus compensator and patient collimator/multi-leaf collimator, better dose efficiency by reducing the number of scatt...

The work of a reinforced concrete beam lying on an elastic foundation is considered, the deformation characteristics which are described by model with two Vlasov-Pasternak bed coefficients. coefficients considered as stationary random normally distributed functions x coordinate. Strength concrete: cube strength and tensile assumed to be variables Gaussian probability density distributions. conc...

Electron powder bed fusion (E-PBF) is an additive manufacturing technology used to produce parts layer-wise for advanced aerospace, biomedical, and other applications. Precise control over the energy transferred by electron beam key further process improvements. Here, we tunable diode laser absorption spectroscopy characterize evaporated titanium atoms above molten area of a TA6V alloy, and, th...

A packed bed thermal storage has several desirable characteristics to be used for energy storage. The behavior of packed bed is predicted by set of differential equations. A numerical solution is developed for packed bed storage tank accounting to the secondary phenomena of thermal losses and conduction effect. The effect of heat loss to surrounding (K1), conduction effect (K2) and air capacita...