This study recognizes and analyzes the basic main factors influencing demand and supply of petroleum; also in addition, with the use of analysis of supply surplus impact on global petroleum market, designs a model for simulation and prediction of oil price.In this model, through the use of modification method of Dynamic Disequilibrium Adjustment Model (DDAM), natural gas price variables, global gross domestic product (GDP), GDP of oil producing countries, production capacity of petroleum, oil supply surplus in market and global oil price, demand and supply of petroleum are being presented. The behavior of natural gas market is transferred meaningfully to the oil market and cause changes in oil price.In the dynamic simulations of model, the impacts of various shocks on supply and demand of oil prices are investigated and it will be predicted for the years 2008 till 2010. So, the designed model indicates that is has proved to have the ability to analyze political shocks and to predict oil prices and can be used in policy making and oil price prediction too.As a result, the model prediction shows that in the years 2008-2010 the oil price will partly go downward, frontier 100$, however this reduction will not reach to the price fall in the 1990 decade.

Simulation and analysis of two phase flow that crosses over tube bundles is crucial in safety analysis and design of kettle reboilers and steam generators. The geometry complexity of the tube bundle flow field increases the difficulty of the conventional numerical analysis. One of the methods to reduce the numerical calculations cost is to use the porous media theory instead of the complete tube bundle modeling. Drag and tube bundle resistance force equations have been used in the porous media analysis. Based on available experimental results, two tube bundle arrangements have been considered. Due to existence of symmetric geometry and uniform energy source over the tube bundle, the two dimensional symmetric models have been used as well. It was observed that the predicted pressure drop in this research has acceptable adaptation with the experimental results. Meanwhile, by considering different outlet boundary conditions, calculated void fraction is compared to the experimental results and showed better accuracy than similar CFD research. It was observed that the enhancement of the tube bundle thermal power increases the void fraction in the heating area of the reboiler.

Milling processes are becoming one of the common manufacturing methods in industry. One of the main goals in any manufacturing operation is to increase productivity. In high speed low immersion milling, the ratio of cutting edge engaging time to spindle period is a small value. For this kind of operations, two types of: Instability are proposed: classical Hopf and the Flip bifurcation, which are mainly due to impact effects of entering/exiting of the cutting edge into the cut. In order to increase productivity, it is essential to anticipate stable machining boundaries. In this research, the main goal is to derive and implement the improved TFEA method to include the effects of the helix angle variations for a 2-DOF vibratory system and accurately compute the stability lobe diagram. Results obtained by simulation witnesses that instability due to Flip bifurcation vanish completely from stability lobe diagram with increasing helix angle to 30°. Experimental tests are conducted in order to confirm the result obtained by the improved TFEA method showing good agreements.

Steels mechanical properties are related to chemical analysis and mainly to the heat treatment. Various thermal processes cause to wide range of properties in steels. Heat transfer and diffusion are two phenomena that determine the micro structure of heat treated steels. It is possible to predict the micro structure of continuous cooled steels with knowing cooling rate and CCT diagrams. Obtaining the cooling rate of internal point of part is difficult. In this research the cooling rate of internal point of cubic CK45 steel calculated in finite difference method. Then obtained diagrams plot on steel CCT diagram and the micro structure of each point and its hardness predicted. When steel heat treated, the part cut and the hardness of studied points measured. Results of hardness measurement validate the simulation calculation.

Researchers are interested in wind resource assessment studies for mountainous terrains using numerical weather prediction methods. In present study the wind over Martigny located in Switzerland has been simulated using weather research and forecasting model. Due to high resolution of the simulation (100 m), large eddy simulation is employed to perform turbulence modeling. The objective of this study is to assess the credibility of model in wind simulation and to examine the effect resolution and two different sub-grid scale turbulence models. The results reveal that model is able to properly generate the wind in comparison with the data obtained from wind measurement stations. The results also show a promising simulation for the region, located within a wide and flat valley. However, the discrepancies between the results and those obtained from the wind station are bold for regions at mountainous peaks. At the time at which the maximum wind speed occurs, it is found that the wind error decreases from 22m/s to 17m/s by changing the sub-grid scale model from Smagronisnky3D to turbulence kinetic energy 1.5 model. Also, the predicted wind speed declines from 17m/s to 7m/s by reducing the vertical size of the grid cells.

Groundwater modeling is widely used as a management tool to understand the behavior of aquifer systems under different hydrological stresses. Eyvanekey alluvial aquifer, which is 126 square kilometers flow budget boundaries, is one of the main aquifer in Semnan province. Indiscriminate exploitation of groundwater in recent years led to a water table shortage in this aquifer. In this study to acquire the aquifer hydraulic parameters, prediction the water table and the flow budget of the aquifer, the modeling approach was used by GMS interface. Model calibrated for steady state in a period of one month (Sep. 2008), and for a period of 12 months (2008-2009 water year) for the transient state, using a hydraulic load for the existing wells in plain view, and calibrating in this way, S, and K values were optimized. The verification process, confirms the validity of the results for unsteady conditions. After the model calibration and verification, water table of the pizometers to September 2013 was predicted. The results show that the current trend of declining aquifer will be continued and at the end of the forecast (Sep. 2013), the water level of the hydrograph represents nearly 898.5 m and in proportion to September 2008 will be decrease 8.3 m. The flow budget result shows that most with drawal is done by extraction wells in spring and summer. The aquifer reservoir deficit is about five million cubic meters during simulation period (87-88).

Introduction: Musculoskeletal problems are the common complaints of patients refer to internal medicine clinics and the pain is the most important of them. There are different physiotherapy methods for reduction of pain and action potential simulation therapy (APS therapy) is one of newest methods. The aim of this study was to determine reduction of pain with APS therapy. Materials & Methods: In 47 patients with different musculoskeletal pain APS therapy performed in 6 days each for 16 minutes and with current of 0.7-1.2 mA. Pain (VAS), Global functional status (ACR) and relief of pain (VAS) before and after study compared.Results: APS therapy reduced pain (p<0.001) and increased Global functional status (p<0.001) and increased relief of pain (p<0.005) but there was not any correlation between this reduction of pain with APS therapy and educational status and past history of physiotherapy and duration of illness in these patients.Conclusion: APS therapy is a useful physiotherapy modality for reduction of pain in musculoskeletal problems.

In industry, the phenomenon of cavitation erosion can reduce the lifetime of the components of hydraulic machines. In this article, we present a new numerical approach to predict the mechanical impact resulting from the implosion of a cloud of bubbles, based on an energy approach. The objective of this approach is to determine the main damage mechanisms and to estimate the intensity of the impact pressure near the surface. The large eddy simulation (LES) approach is coupled with a homogeneous cavitation model to assess the risk of erosion around the hydrofoil NACA0009. Indeed, three functions, namely the Pressure Intensity Function (PIF), the steam intensity function and the Erosive Power Function (EPF), are applied to assess the spatial distribution of eroded areas. The calculations show that the functions based on the pressure term are in good agreement with the experiments, namely: the PIF and EPF functions. On the other hand, we assume that the implosion of the cloud of bubbles produces a pressure wave, which in turn causes the implosion of small bubbles near the wall. Then the erosion will be the result of these secondary implosions and not of the cloud of bubbles. Therefore, we vary the degree of proximity of these micro-bubbles near the wall to choose either the shock wave or the micro-jet to extrapolate the pressure field. We can compare these estimates with the existing erosion measurements and we can conclude that the calculations respond more to the probability of the presence of a micro-jet than to the presence of a shock wave.