The aim of this paper is to determine the best optical-probe
geometry that would help to detect neoplastic lesions in oral
epithelial tissue. Two Geometrical configurations are investigated.
The first one implements different distances between the
illumination and collection fibers, and the second one implements
different fiber diameters.
Both of these geometries are evaluated for their collection efficiency
and depth resolution. The effect of numerical aperture (NA) and
tissue optical properties on the fluorescence signal are also studied.
Optical properties of dysplastic tongue epithelial multi-layered
tissue were used as an input for Monte Carlo simulation. The results
show that the sensitivity to superficial layers can be achieved using
small fiber diameters. On the contrary, the sensitivity to deeper
layers can be achieved using larger distances between illumination
and collection fibers.
The aim of current work is to develop a mathematical model designed by Rabl for
compound parabolic collector (CPC) using tubular receiver instead of the flat receiver. The
simulation was carried out for reflection of direct and indirect solar radia
tion incident on
the compound parabolic collector.
The equations were evaluated using analytical geometry for calculating the Cartesian
coordinates of the reflecting surface, then the falling and reflected rays on the detector
were calculated. A MATLAB program was developed to generate the data and print the
reflected rays through the use of 10000 rays at random position according to the random
Monte Carlo simulation for each angle of the rays. We found that the optimum value of
half acceptance angle is 35.
This investigation showed that the efficiency of compound parabolic collector
decreases with increasing the radius and length of receiver at the same inlet temperature of
working fluid. Also showed that the efficiency of compound parabolic collector with
tubular receiver is higher than collector with flat receiver at the same conditions.
To calculate the dose distributions of 6 MeV photon beam at variable depth
in 3D water phantom the MCNP4C2 code was used, and the simulated dose
profile was compared with that of the treatment planning computer system
(TPS), and a good agreement w
as found between them.
In conclusion, the MCNP4C2 code package presents a good tool adaptable
to get dose distributions for the 6MeV photon beam and it can be considered as
confirmed method for patient dose calculations.
