Introduction: The photoelectric attenuation coefficient of substances is known to depend upon the energy E of the photon and the effective atomic number of substances (Zeff) as (Zeffx/Ey).  No definitive values about these indices x, y are given in the literature. The index x is said to lie between, 3.0 and 4.0, while for ‘y’ different values have been assigned, between 3.0 and 4.0. Method...

introduction lead-based shields are the most widely used attenuators in x-ray and gamma ray fields. the heavy weight, toxicity and corrosion of lead have led researchers towards the development of non-lead shields. materials and methods the purpose of this study was to design multi-layered shields for protection against x-rays and gamma rays in diagnostic radiology and nuclear medicine. in this...

Introduction Lead-based shields are the most widely used attenuators in X-ray and gamma ray fields. The heavy weight, toxicity and corrosion of lead have led researchers towards the development of non-lead shields. Materials and Methods The purpose of this study was to design multi-layered shields for protection against X-rays and gamma rays in diagnostic radiology and nuclear medicine. In this...

introduction superficial x-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (up to 300 kvp). quality of the x-ray beam that can be expressed by half-value layer (hvl), are important indices for this type of treatment effective energy of photon and homogeneity coefficient (hc). materials and methods the hc of the s...

Non-destructive techniques with X-ray, such as tomography, radiography and X-ray fluorescence are sensitive to the attenuation coefficient and have a large field of applications in medical as well as industrial area [1,2]. In the case of X-ray fluorescence analysis the knowledge of photon X-ray attenuation coefficients provides important information to obtain the elemental concentration. On the...

Introduction Superficial X-ray therapy is one of the most important treatment methods in radiotherapy especially in the treatment of superficial skin lesions (Up to 300 kVp). Quality of the X-ray beam that can be expressed by Half-Value Layer (HVL), are important indices for this type of treatment effective energy of photon and Homogeneity Coefficient (HC). Materials and Methods The HC of the s...

We review theoretical models to show that contrast reduction at a specific wavelength in the horizontal direction depends directly on the beam attenuation coefficient at that wavelength. If a black target is used, the inherent contrast is always negative unity, so that the visibility of a black target in the horizontal direction depends on a single parameter only. That is not the case for any o...

introduction:  the use of radioactive iodine (131i) has become an important adjunct to the treatment of thyroid cancer and hyperthyroidism. salivary gland has the ability to concentrate radioactive iodine under normal circumstances. salivary gland dysfunction and dry mouth are the common side effectsof high-dose radioiodine therapy. the purposeof this study was to determine the absorbed dose of...