The cosmic-ray method for measuring soil moisture, used in the Cosmic-Ray Soil Moisture Observing System (COSMOS), relies on the exceptional ability of hydrogen to moderate fast neutrons. Sources of hydrogen near the ground, other than soil moisture, affect the neutron measurement and therefore must be quantified. This study investigates the effect of atmospheric water vapor on the cosmic-ray p...

introduction: osteoporosis is a bone disease in which there is a reduction in the amount of bone mineral content leading to an increase in the risk of bone fractures. the affected individuals not only have to go through lots of pain and suffering but this disease also results in high economic costs to the society due to a large number of fractures.  a timely and accurate diagnosis of this disea...

Anthropometric and anthropomorphic phantoms have been used extensively for characterizing in-vivo measurement systems that determines internally deposited radionuclides. The accuracy in activity determination relies critically on system design, calibration routine, and reproducbility in material composition, geometry configuration, and physical dimensions of the phantoms respect to the actual o...

background: iodine brachytherapy sources with low photon energies have been widely used in treating cancerous tumors. dosimetric parameters of brachytherapy sources should be determined according to aapm tg-43u1 recommendations before clinical use. monte carlo codes are reliable tools in calculation of these parameters for brachytherapy sources. materials and methods: dosimetric parameters (dos...

In this paper, the pricing of a European call option on the underlying asset is performed by using a Monte Carlo method, one of the powerful simulation methods, where the price development of the asset is simulated and value of the claim is computed in terms of an expected value. The proposed approach, applied in Monte Carlo simulation, is based on the Black-Scholes equation which generally def...

Introduction: Nowadays new radiochromic films have an essential role in radiotherapy dosimetry. Properties such as high sensitivity, good reproducibility, high spatial resolution, easy readout and portability have made them attractive for dosimetry, especially in high-dose-gradient regions. Material and Methods: In this study, electron-beam dose distributions in homogenous and heterogeneous pha...

Introduction Pterygium is a wing-shaped, vascular, fleshy growth that originates from the conjunctiva and can spread into the corneal limbus and beyond. Beta irradiation after bare sclera surgery of primary pterygium is a simple, effective, and safe treatment, which reduces the risk of local recurrence. Materials and Methods Dosimetric components of strontium-90 (90Sr), phosphorous-32 (32P), an...

as a result of being hydrogenous moderators, several landmine detection methods based onnuclear techniques have been suggested in recent years. because of elastic scattering and moderating neutrons from hydrogen atoms in landmines, detection of backscattered neutron shows an anomaly in the reflected thermal neutrons count when a detector scans over a mine. on landmine detection using neutron so...

background: recently, different investigators have studied the possibility of radiation therapy in restenosis prevention and have shown promising results. in this study a unique radioactive source for intra vascular brachytherapy (ivbt) was investigated. the two-dimensional dose distribution in water for a 32p ivbt stent has been calculated. the pure beta emitter source 32p has been coated on p...