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In the last decade there has been growing interest in the possibility of characterizing breast cancer using differences in the coherent x-ray-scattering profiles of normal and malignant tissues. To a great extent, characterization has depended on the differences in the peak positions of both tissues in addition to the overall profile which exhibits a distinctive sharp adipose peak in the case of a normal breast. In many excised tissue samples, breast cancer samples may be mixed with a variable percentage of other tissues which affect the shape of the x-ray-scattering profile and consequently the ability to characterize the tissue. Moreover, fibroglandular tissue produces a scattering profile showing an extent of similarity to breast cancer. The present study introduces a Monte Carlo simulation code capable of tracing photon transport inside a mixed two-component sample. The code is utilized to simulate and best fit x-ray-scattering profiles of the measured samples. This provides reliable breast tissue characterization in addition to a quantitative estimate of the percentage of each component in a given sample. It is expected that the present simulation would potentially enhance the characterization of breast cancer using the x-ray-scattering technique.

Films of cellulose acetate (CA) have been prepared by casting method using tetrahydrofuran (THF). CA films are γ-irradiated with varying radiation doses of 10, 20, 30, 40, 50 and 60 kGy using cobalt-60 ( 60 Co) source. Global thermally stimulated depolarization current (TSDC) of non-irradiated and irradiated CA samples has been investigated under the effect of various poling electric field (Ep) in a temperature range from 300 K to 440 K. It is observed that, global TSDC spectra of non-irradiated and irradiated CA samples are characterized by two relaxation peaks. One in the low temperature range ~321 K and the other in the high temperature range ~ 376-383 K are observed for non-irradiated sample. On the other hand, these temperatures are shifted towards lower temperature for irradiated samples to be located at 317 K and ~371 K. These relaxations are assigned as  and -relaxation and attributed to molecular motion of the polar acetate groups, C2H3O2 and polarization of the space charges, respectively. TStechnique has been carried out to decompose global TSDC spectra of all samples into its elementary peaks and the molecular parameters such as, activation energy and pre-exponential factor are calculated for each TS peak. Relaxation map (RM) of all samples has been analyzed using Eyring transformation and thermodynamic parameters such as, enthalpy activation (H), entropy activation (S) and Gibbs free energy (G) are estimated. The compensation phenomenon was verified by the linear relationship between both enthalpy and entropy.

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Poly (Vinyl Alcohol)/Copper Chloride (PVA/CuCl and 20 wt% of CuCl 2 . UV-Vis spectrum of these composites is investigated in the range of 200 spectrum of PVA showed an absorption band at 278.18 nm and a small shoulder at 313.09 nm and are assigned to  * transition, respectively. On the other hand, the spectra of the PVA/CuCl resonance (SPR) band in the visible band at 778.07 nm. Moreover, it is observed that, the absorption edge of composite samples is red shifted. Also, pure PVA showed an which decreased to 3.48 and 3.92 eV after CuCl also observed that nonlinear optical parameters such as thi refractive index (n 2 ) are influenced by CuCl These results are very encouraging for possible applications constant ( ' ), dielectric loss ( '' ) and photoconductivity have been investigated

Iodine-doped Poly (Ethyl Methacrylate) composites have been prepared using casting method. Global TSDC of the composite samples has been investigated using TSDC-TS technique. It is found that, global TSDC spectra of pure PEMA are characterized by two relaxations. The first relaxation which is observed as a shoulder in the temperature range 324-333 K is attributed to the motion of side group and named -relaxation. Whereas, the second relaxation is observed in the glass temperature range of PEMA at Tm= 347 K and named as dipolar relaxation, i.e., -relaxation. On doping with iodine, a new relaxation peak has been obtained at high temperatures ~ 397-409 K, and named as space charge relaxation, i.e., -relaxation. Complex TSDC spectra of PEMA-Iodine composites have been resolved into its elementary peaks using TS technique. These elementary peaks have been used to construct relaxation map (RM) of all samples using Eyring transformation. The existence of compensation phenomenon for all samples is also verified and the coordinates of each compensation point have been estimated. These coordinates are used to calculate the density of disorder (DOD) and thermal expansion coefficient of the samples. The thermodynamic parameters of the samples, such as, enthalpy, entropy and Gibbs free energy have been calculated at different poling temperatures.

Dielectric measurements of chitosan/PVA polymer blends were performed at various temperatures in a wide frequency range.Higher values of  ' and '' at higher temperatures and lower frequencies are correlated to interfacial polarization (IP) and DC conduction, respectively. Isochronal behavior of // against temperature revealed that chitosan and PVA is characterized by a dipolar relaxation peak at T= 393 K and 348 K, respectively. The activation energy (Ea) values of conduction have been estimated for all samples. Cole-Cole behavior revealed that, with increasing the temperature the semicircles area of the samples increased and the semicircle intercept are shifted towards higher value of / indicating that, the capacitance is increased. Complex electric modulus (M*) of all samples is investigated and it is found that, real part (M/) of the complex electric modulus showed nonlinear behavior with frequency, whereas, (M//), i.e., the imaginary part, is characterized by a relaxation peaks for all samples. The scaling behavior has been carried out at T= 333 K, as a representative temperature and it is found that, all the curves are overlapped leading to a master curve indicating that, dynamic process is temperature independent.

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