The interaction of thruster plumes with satellite components can have undesirable effects, such as disturbance force/torque, thermal loading, and species deposition in the surfaces. The purpose of this paper is to use the Direct SIMULATION MONTE Carlo (DSMC) method to analyze the 3D plume impingement flows and investigate its effects. Two impingement problems are computed. The impact of a jet of nitrogen on an inclined flat plate is considered. Good agreement is found between surface quantities calculated by DSMC and experimental data. The plume of a hydrazine control thruster firing in a model satellite configuration is simulated. Surface quantities and net impingement effects are calculated. The effects of partial displacement of the thruster locations on the results have also been investigated. The results show that a 20% displacement of the thruster location can change the disturbance force/torque by up to 15% of the initial values.

With use of the Trotter's technique SIMULATION for one - dimensional XYZ Heisenberg systems of spin -1/2 have been performed. It is shown that the one- dimensional quantum systems can be transformed to the two- dimensional classical systyems by Trotter's technique. The extra dimension found to be like an imaginary time which has been related to the temperature of the system. Several chanis of one - dimensional spin systems are simulated by MONTE carlo method and the thermodynamic quantities of these are calculated at low temperature by means of this technique. Comparison is made with Bonner &Fisher's exact data which is found tobe in good agreement with their results.

Pulse oximetry and oxygen saturation monitoring improve the medical care methods such as anesthesia and infants’ intensive care. Pulse oximetry method is basically more efficient than monitoring the fetal heartbeat since direct oxygen saturation measurement from fetal blood would be possible. The designing of device, including choice of an appropriate wavelength and space for monitoring, plays a significant role in improving its sensitivity to the depth and arterial pulse rate. This study simulates the interaction between light and tissue based on MONTE Carlo’s method and uses the results to construct the pulse oximeter.Method: For this purpose, a 10-layered tissue model, with different sizes of thickness, including artery pulses of systole and diastole phases, has been considered. Also, this study focuses on the separation of information related to mother and fetus.Result: According to the best location of detectors and trial and error method, the optimal wavelengths of 675 and 800 nanometers have been achieved. Studying only the single effect of each one of (shot and electronic noises) on the model shows the significant difference between the percent of input oxygen saturation and outcome results. However, considering these noises simultaneously causes less difference. The SIMULATION results are obtained in different wavelengths, using 106 photons and 49 detectors. The percentage of oxygen saturation, in comparison with the input database, has exhibited 2% error deviation from zero.

Studying stock options is still a pristine area of research in the Iranian capital market. This is due to the lack of data as well as the complexity of valu-ation methodologies. In the present paper, using the MONTE-Carlo SIMULATION, we have estimated the value of stock options traded on Tehran Stock Exchange and examined whether the use of a control variate or antithetic variate augmented methods can lower the standard error of estimates. Furthermore, the estimated values of the three models under consideration, including of crude MONTE-Carlo, control variates augmented MONTE-Carlo, and antithetic variates augmented Mon-teCarlo are compared with each other and with options market prices. The results show that the standard error of the antithetic variate method is less than the crude method and control variate method. However, control variate augmented MONTECarlo model is more powerful than the crude MONTE-Carlo and antithetic variate augmented MONTE-Carlo method. Therefore, we can conclude that the control variate augmented MONTE-Carlo model has a better performance in estimating the value of trading stock options and its estimated values are closer to the market prices.

Background and Aim: Liposuction is one of the most popular procedures for removing unwanted body fat deposits now. The conventional methods for liposuction however have many drawbacks; among them is long recovery time, scars, bruising, skin flaccidity and excessive blood loss. Considering the increasing demand for body sculpting, the need to improve these techniques is of vital importance. One of these newly proposed techniques is laser assisted lipolysis. Laser lipolysis is now widely used for body contouring and sculpting. Less trauma, bleeding and pain is among the main advantages of this method.Methods: Photons propagation and scattering within the biological tissues can effectively investigated by using numerical methods. In this study we used the MONTE Carlo SIMULATION method to simulate photons directions, absorption and scattering inside the tissue. This method uses a random number generator for photons creation, moving inside the tissue and termination. In this SIMULATION we considered both the wavelength and fluence variations effects on the photon absorption rate and penetration depth inside the fat tissue.Results: Our study showed the increasing of penetration depth with decreasing of absorption coefficient. We observed that deepest penetration depth for 920 nm wavelength as it has lowest absorption coefficient. We also concluded that increasing the laser power (increase in fluence of laser) resulted in increasing the penetration depth of laser radiation.Increasing the radius of laser beam (decreasing the fluence) on the other hand resulted in reduction in penetration depth.Conclusion: MONTE Carlo SIMULATION of radiation propagation within the biological tissue has proved to be an efficient method. This method effectively simulates the physical components of laser radiation. Our findings indicate that to have laser lipolysis more efficient and safe, it is essential to choose suitable wavelength.