نتایج جستجو برای: attenuation relation
تعداد نتایج: 342633 فیلتر نتایج به سال:
Background: Lead glass has a wide variety of applications in radiation protection. This study aims to investigate some characteristics of lead glass such as the γ-ray energy-dependent mass and linear attenuation coefficients, the half-value layer thickness, and the absorbed dose distribution for specific energy. Materials and Methods: The attenuation parameters of different lead glass types aga...
background: photon attenuation as an inevitable physical phenomenon influences on the diagnostic information of spect images and results to errors in accuracy of quantitative measurements. this can be corrected via different physical or mathematical approaches. as the correction equation in mathematical approaches is nonlinear, in this study a new method of linearization called ‘piece wise line...
Background and aims: X-band microwave with 8-12.5 frequency range has various applications such as air control traffic, navy communication and etc. Uncontrolled exposure with microwave can lead to adverse effect on workers. Application of the shielding is superior control for prevention of microwave exposure.The aim of this study is production a new electromagnetic shielding for exposure contr...
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 stu...
Edge illumination (EI) x-ray phase contrast computed tomography (CT) can provide threedimensional distributions of the real and imaginary parts of the complex refractive index ( δ β = − + n 1 i ) of the sample. Phase retrieval, i.e. the separation of attenuation and refraction data from projections that contain a combination of both, is a key step in the image reconstruction process. In EI-base...
Raindrop size distribution (DSD) retrieval from remote radar measurements or from in situ disdrometer measurements is an important area of research. If the shape ( ) and slope ( ) of a three-parameter gamma distribution n(D) N0D exp( D ) are related to one another, as recent disdrometer measurements suggest, the gamma DSD model is simplified to a two-parameter DSD, that is, a constrained gamma ...
Polyphenols represent a group of secondary metabolites plants which have been analyzed as potent regulators multiple biological processes, including cell proliferation, apoptosis, and autophagy, among others. These natural compounds exhibit beneficial effects protection against inflammation, oxidative stress, related injuries metabolic diseases, such cardiovascular damage, obesity diabetes, neu...
under the contemporary scenario of global climate change and increasing coastal eutrophication, baseline studies of phytoplankton diversity and distribution in relation to habitat conditions constitute the first approach to evaluate potential shifts at the base of the food webs. here we present data of phytoplankton species composition and environmental variables in winter 2006 in a temperate e...
The attenuation ability of composites containing micro and nano-sized WO3 was measured and compared with the attenuation ability of composites containing micro-size and nano-sized PbO for X-rays in diagnostic energy range. For the purpose, after synthesizing nano and micro-scaled particles, different percentages of them were imbedded in poly vinyl chloride (EPVC) emulsion and prepared as shield...
in a recent paper, de baets et al. have characterized the fuzzytolerance and fuzzy equivalence relations that a given strict order relation iscompatible with. in this paper, we generalize this characterization by consideringan arbitrary (crisp) relation instead of a strict order relation, while payingattention to the particular cases of a reflexive or irreflexive relation. the reasoninglargely ...
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