the first zagreb index $m_1$ of a graph $g$ is equal to the sum of squaresof degrees of the vertices of $g$. goubko proved that for trees with $n_1$pendent vertices, $m_1 geq 9,n_1-16$. we show how this result can beextended to hold for any connected graph with cyclomatic number $gamma geq 0$.in addition, graphs with $n$ vertices, $n_1$ pendent vertices, cyclomaticnumber $gamma$, and minimal $m...

to assess the environmental radioactivity levels and hence to determine the population exposure in kutubdia island, bangladesh the sediment samples were analyzed by using gamma ray spectrometry. in those sediment samples the average activity concentration of natural radionuclides 238u, 232th and 40k were found 15.39±1.67, 38.35±0.76 and 475.51±21.15 bq/kg respectively. the activity concentratio...

Background: Natural radionuclides in rock samples, primarily 238U (uranium), 232Th (thorium) and 40K (potassium), are the main source of radiation exposure to workers and general public and their measurement is of paramount importance from radiation protection point of view. Materials and Methods: Gamma spectrometry using HPGe detector was used to measure the radioactivity and assess the radiol...

abstract spi is based on fitting a gamma distribution to precipitation amounts in selected periods. based on current research, the gamma distribution may not be fitted to annual precipitation of some regions. in order to evaluate this subject, annual precipitation have been used during 1958- 2007 at 11 synoptic stations in iran. in first step, values of spi and frequency of different classes of...

Background: Periodontitis is an inflammatory disease of tooth-supporting tissues. The present study was conducted to evaluate Interleukin-10 (IL-10) and Interferon gamma (IFN-γ) levels in gingival crevicular fluid (GCF) of patients with chronic periodontitis. Materials and Methods: This case-control study was carried out on 60 men including 30 smokers and 30 age-matched non-smokers. The ...

the aim of this study is to provide a control software system, based on monte carlo simulation, and calculations of dosimetric parameters of standard and wedge radiation fi elds, using a monte carlo method. gate version 6.1 (opengate collaboration), was used to simulate a compact 6 mv linear accelerator system. in order to accelerate the calculations, the phase-space technique and cluster compu...