نتایج جستجو برای: density and attenuation
تعداد نتایج: 16878946 فیلتر نتایج به سال:
in this thesis, structural, electronical, and optical properties of inverse pervskite(ca3pbo) in cubic phase have been investigated.the calculation have been done based on density functional theory and according to generalized gradiant approximate (gga) as correlating potential. in order to calculate the configurations, implementing in the wien2k code have been used from 2013 version. first of ...
abstract chickpea is weak in competition of weeds that damages to it at between 40 t0 60 percent. kermanshah province is one of the most important region for chickpea fields in iran. for these reosons, weed management is necessary in this crop. in order to evaluate of herbicides and stubble control on broad leave weeds control in chickpea. experiment was conducted in agricultural research stat...
in this study, the effects of oleothermal modification on physical and mechanical peroperties of fir wood (abeis sp.) blocks were examined. at first, some blocks of fir wood with 5 × 20 × 120 cm dimensions were prepared. the blocks were treated in soybean oil. the effects of 3 factors such as treatments temperature (180and 200 °c), holding time (12 and 15 h) and initial moisture content of wood...
in this investigation the effect of external field on the electron density of nanostructures of cds, cdse, cdte, gaas and polymeric structure of three, four, five and six units of cds as a kind of nanosolar cells has been studied theoretically. as modeling this system in nanodimension, molecular structures has used. specific properties of molecular structures permit us to consider different sym...
this research was conducted in two protect and destroy region in the middle zagros, in illam province. in order to identification of ecological species group and evaluate density of regeneration, effect of many factors such as protection, vegetation, physiographic factors, physical and chemical properties of soil in study locations were studied. to achieve these purpose number of 54 plots using...
introduction: globally, the need for radiotherapy as a part of cancer management increases every year. thus, the shielding for megavoltage radiotherapy rooms is of great importance. materials and methods: in the present study, 14 types of developed high-density concrete with densities ranging from 2.45 to 5.11 were simulated by using monte carlo method. the linear attenuation coefficient and th...
among the low–dimensional allotropes of carbon, nanotubes and graphene have attracted very much attention from nano–science and nanotechnology specialists. they have been proposed as building blocks in nanometer device engineering. however, these structures are not defect–free. in this thesis, we focused on defective carbon nanotubes and graphene, and studied the effect of couple of very common...
Introduction: Globally, the need for radiotherapy as a part of cancer management increases every year. Thus, the shielding for megavoltage radiotherapy rooms is of great importance. Materials and Methods: In the present study, 14 types of developed high-density concrete with densities ranging from 2.45 to 5.11 were simulated by using Monte Carlo method. The linear attenuation coefficient and t...
simplification universal as a universal feature of translation means translated texts tend to use simpler language than original texts in the same language and it can be critically investigated through common concepts: type/token ratio, lexical density, and mean sentence length. although steps have been taken to test this hypothesis in various text types in different linguistic communities, in ...
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...
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