models can be used to predict crop yield and inputs levels such as fertilizer, in order to conduct programming for the management of probable future crisis. in this study, based on the model, the effect of nitrogen fertilizer on dry matter partitioning in shoot and root of sugar beet was predicted. for model construction, data were collected from an experiment conducted in karaj city in 2001. i...

introduction: ordered subset expectation maximization (osem), is an effective iterative method for spect image reconstruction. the aim of this study is the evaluation of the role of system matrix in osem image reconstruction method using four different physical beam radiation models with three detection configurations. methods: spect was done with an arc of 180 degree in 32 projections after i...

solar radiation data play an important role in solar energy relevant researches. these data are not available for some locations due to the absence of the meteorological stations. therefore, solar radiation data have to be predicted by using solar radiation estimation models. this study presents an integrated artificial neural network (ann) approach for estimating solar radiation potential over...

today, nuclear medicine has rapidly been developed so that in some cases, plays a unique role in diagnosis but unfortunalty in spite of diagnostic and therapeutic advantages, the term “nuclear” can induce worries in patients and society. in this article, base on new documents, we intend to show that this worries has no scientific basis. to produce a realistic view, regarding to radiation protec...

during the past years, special emphasis was put on medical preparedness in the event of radiological or nuclear emergencies. novin medical radiation institute (nmri) encouraged and supported the national authorities to enhance their cooperation in improving medical response to radiation accident. nmri in cooperation with international atomic energy agency (iaea) and atomic energy organization o...

the main driving force of the earth atmospheric system is solar radiation. radiation flux determines the surface temperature and impacts life on the earth through photosynthesis. a quantitative knowledge of the earth radiation field is important to evaluate the atmosphere–surface interactions and the global hydrological cycle. various atmospheric radiative transfer models have been proposed in ...

introduction: solar net radiation (rn) is one of the most important component which influences soil heat flux, evapotranspiration rate and hydrological cycle. this parameter (rn) is measured based on the difference between downward and upward shortwave (sw) and longwave (lw) irradiances reaching the earth’s surface. field measurements of rn are scarce, expensive and difficult due to the instrum...

Introduction: The purpose in this study is to analyze of DVH parameters as predictors of radiation pneumonitis and investigation on the relationship between dosimetric and clinical parameters based on PFTs as response in NTCP model and therefore achieve to lung dose- response relation in breast cancer patients. Prescribed dose to treatment volumes was 50 Gy in 2.0 Gy/fractions ...

This paper presents an approach to modeling of field penetration and gives contribution to understanding the real effects of the fields and the sensitivity of human model to electromagnetic radiation generated by mobile antenna. When a human body is exposed to the electromagnetic radiation, because human body contain 70% of liquid, and it contain more liquid near of head, heart, abdomen (near o...