A methane-air turbulent premixed flame is simulated via probability density function (PDF) and Reynolds averaged Navier-Stokes (RANS) methods. In the PDF approach, molecular mixing is modelled through the modified Curl’s model. A Monte Carlo method is used to solve the PDF transport equation. Also, the run time averaging and local time stepping procedures are incorporated to increase the accuracy and reduce the computational time of the PDF simulation. In the RANS approach, the averaged chemical reaction rate term is modeled by the eddy breakup-finite rate model. A finite difference discretization on a staggered grid is utilized to obtain the numerical solution for the RANS equations. The characteristics and differences of the two above mentioned methods, including computational time and predicted mean fields, are investigated in detail for premixed flames. It is observed that the discrepancy of the predicted mean fields between the two methods is large especially in regions near the flame. In addition, the predicted flame length by the PDF method is approximately half the flame length predicted by the RANS method.

In this study, a new method for producing initial conditions that are required for the Brownian dynamics simulation of dilute polymer suspension flows is proposed. For this purpose, the equilibrium probability distribution function is employed to generate an equilibrium ensemble of polymers. This approach is programmed and by using it, a polymer suspension in the inception of a simple shear flow is simulated. Also, the results of simulations in a similar flow configuration based on the conventional approach of generating initial conditions are presented. The excellent agreement between the results demonstrates the high accuracy of the proposed method for generating initial conditions. The main advantage of the proposed method is its low computational cost.

This paper introduces a new model for predicting the tropospheric scintillation path loss with respect to Iranian climate. Tile variance, probability density function (PDF), and attenuation scintillation are predicted based on the new model and using measurement data obtained from Iranian metrological department for different parts of Iran. Applying this model and corresponding data, the variance of scintillation, scintillation pathl loss and scintillation ,standard deviation predicted for different Iranian cities. The results reveal that scintillation variance PDF shows a long normal behaviour in Iran. Moreover, the path loss due to scintillation phenomenon in satellite- ground communication links cannot be ignored particularly in microwave and higher frequency ranges. Therefore, it is necessary to take into account these effects when designing satellite- ground and microwaves communicational links.

Background and Objectives: Marital satisfaction and compatibility of spouses are axis and focus of family foundation, which are influenced by different factors. One of these factors is occupational status of each spouse The current study was carried out with the aim of evaluating the marital satisfaction in female nurses of Khalkhal city.Methods: This research was conducted as a descriptive cross-sectional study on 120 female nurses of Khalkhal city in 2014. The sampling method was non-probabilistic convenience sampling. Data were analyzed using Kolmogorov-Smirnov, Spearman correlation coefficient, independent t-, one-way ANOVA, Friedman, and multiple liner regression tests at the significance level of p<0.05.Results: The total study population was 120 female nurses with the mean age of 34.03±6.52 years. Ninety-nine subjects (82.5%) had very high satisfaction, 14 subjects (11.7%) high satisfaction, and 7 nurse (5.8%) moderate satisfaction. There was a significant relationship between marital satisfaction and number of sex (p<0.001) and occupation of spouse (p<0.04). The predictor variables effective in marital satisfaction are related to baby number (Beta=2.64, p>0.01) and working experience (Beta=1.85, p>0.04).Conclusion: In this study, the level of marital satisfaction was reported to be high among nurses of Khalkhal. Perhaps more complete and extensive investigation could show the cause of high satisfaction among nurses. Also, identification of the factors promoting marital satisfaction could be used as a strategy to teach spouses of other trade and professional groups, in whom satisfaction level is low.

This paper proposes a novel two step modeling and analysis on the continuous random variable of electricity price. At the first step, the continuous optimal control theory is used to model and solve the maximum entropy problem for a continuous random variable. The maximum entropy principle provides a method to obtain least-biased Probability Density Function (pdf) estimation. In this paper, to find a closed form solution for the maximum entropy problem with any number of moment constraints, the entropy is considered as a functional measure and the moment constraints are considered as the state equations. Therefore, the pdf estimation problem can be reformulated as the optimal control problem. At the second step, the proposed unbiased pdf estimator is used to estimate the pdf of electricity price. Moreover, the statistical indices and the distributional characteristics of electricity price are analyzed at each load level. The simulation results on the electricity price data of New England, Ontario and Nord Pool electricity markets show the efficiency of the proposed pdf estimator. In addition, the obtained results show that by decreasing the load, the statistical and distributional characteristics of the electricity price inclined toward the statistical properties of the normal distribution.

As one of the most destructive earthquakes in the world and threatening the destruction of human life-the environment is. And damage caused by its dimensions (physical, social, etc. ) realize that modern urban living style and the most vulnerable in the world to be. But this natural phenomenon itself and the potential damage in any location cannot be. Preparation and careful planning, but also to determine the degree of damage control can determine the degree of reduction of the earthquake disaster is an undesirable outcome. The physical and social dimensions of the issue is about double the damage of the earthquake will be necessary. The study of the nature of "development-applied" research "descriptive-analytical" The city has investigated the matter. And the only means of determining damages arising from the information and quantitative methods-is significant, this study using 117 variables and uses techniques SMART-Entropy, PDF, KS and GIS, and Software Excel and SPSS software to zoning and earthquake damage assessment studies. The general index of the 117 in the urban area of Yazd region 2 SMART-Entropy, 578/0 of the region's most vulnerable city against earthquake risk is. And the risk model, the one with the PDF has the lowest rate of 39% in the three cities of Yazd and KS incidence rate due to having a concrete and metal building materials, by far the lowest mortality rate man in the city when the earthquake. concrete and metal building materials, by far the lowest mortality rate man in the city when the earthquake.

Magnetic resonance imaging (MRI) is one of the most powerful techniques to study the internal structure of the body. MRI image quality is affected by various noises. Noises in MRI are usually thermal and mainly due to the motion of charged particles in the coil. Noise in MRI images also cause a limitation in the study of visual images as well as computer analysis of the images. In this paper, first, it is proved that probability density function (PDF) of MRI images is rician because of the process of image capturing and MRI hardware. Based on the review of later works in this area, it is determined that rician denoising in wavelet domain is better. Then, it is concluded that the remaining noise in the final output of the conventional methods in wavelet domain, is Gaussian and can be greatly reduced with a Gaussian adaptive filter. Based on this estimation, a Gaussian filter designed and the output image was filtered again. The results showed that the final image quality will improve considerably. As a conclusion, in similar situations, our proposed algorithm is always better than the others.