In this article, an attempt has been made to estimate the amount of sound transmission loss in a flat oval channel by applying the approach of statistical energy analysis. Correct estimation of sound transmission loss in an air conditioning channel is of great importance due to the harmful effects of noise pollution in the environment on human health. Simulation with the statistical energy analysis method is a powerful approach to estimate sound and vibration in problems in which we deal with complex and multi-part systems; is considered. In this method, first, a system is divided into several subsystems, and then by writing a matrix equation that includes the energy exchanges between subsystems and energy loss coefficients; It is investigated from the perspective of vibration and sound estimation.On average, the model presented in this research is able to estimate the sound transmission loss in different dimensions of the air conditioning channels according to the experimental results in the accuracy range of ± 2.5 dB. Considering that it seems that the results obtained from modeling with this method are in good agreement with the experimental data; The results of this research can be used as an efficient approach to estimate noise in oval shaped channels stretched in different lengths.

Purpose: To report visual and anatomical outcome of flap loss after LASIK surgery for correction of high myopia. Materials & Methods: Retrospective evaluation of flap loss in two eyes of two patients, a rare complication of LASIK Surgery. Case No. 1: 27 y/o woman with Ref. OD -9.75; 2.75*177 VA. CC: 20/60 KR OD: 41.86*77 39.86 * 168 & partial amblyopia due to anisometropia. Case No. 2: 38 y/o woman with Ref OD. -9.50 1.0*177 VA CC: 20/30 KR OD: 42.06*77 40.99 * 167. Results: In both patients during LASIK surgery free cap complication occurred and after Laser therapy free cap positioned over the stromal bed, but the next day after operation flaps were lost. For case NO.1only medical management performed and after 4.5 years F/U cornea has 2° central haziness. For case NO.2 another corneal flap from donor globe cut and sutured with Nylon 10/0 and after 18 months F/U cornea is clear. Conclusion: In patients with flat keratometry less than 41.0 Diopter rate of free cap are high and after laser therapy for high myopia the keratometry became more flat. If surgeon doesn't suture flap the rate of flap loss increase so for prevent of corneal haziness and corneal ectazia this evaluation suppose to perform donor corneal flap graft.      

In this paper, an attempt has been made to introduce a new control strategy including Plug-in Hybrid Electric Vehicle (PHEV) and Diesel engine generator to control the voltage and frequency of autonomous microgrids. The proposed control strategy has multiple advantages over the recent control methods in microgrids. The proposed method applies the primary and secondary frequency control strategy, simultaneously. However the secondary voltage control scheme is obligatory. In present study, Artificial Neural Networks (ANN) has been implemented for training and validating the advanced droop control (ADC). After ADC unit training, the inverter based DG can be installed in complex microgrids consist of several DGs and loads. Simulation results indicate the effectiveness and applicability of proposed method in controlling the voltage and frequency in autonomous microgrids.

A ‘ spillway’ is a structure used to provide the controlled release of flood water from upstream into downstream area of a dam. As an important component of every dam, a spillway should be constructed strongly, reliably and efficiently to be used at any moment. Labyrinth and stepped spillways are presented as appropriate modifications to those spillways hardly capable of managing the maximum potential discharge. Owing to their nonlinear crests for a given width, labyrinth and stepped spillways have a larger discharge rate than linear-crest spillways at an identical height. Compared to other energy dissipaters, the combination of stepped and labyrinth spillways is known as a very strong energy dissipater. In the following part, the combination of these two structures and their dimensional change for increasing the water-energy dissipation are addressed. To conduct this study, an experimental flume with a 90-degree bend in the Islamic Azad University of Ahwaz was used. In total, 90 experiments were conducted on three different labyrinth-shape stepped spillway models with two different lengths, three different widths, and five different discharges. Analysis of the results showed a greater energy loss reduction in triangular rather than rectangular or trapezoidal labyrinth-shape stepped spillways. In addition, energy loss was greater in labyrinth spillways with two cycles than those with one cycle. Energy loss was increased by raising the Froude number from 0. 05 to 0. 1; in contrast, energy loss was decreased with increasing the Froude number from 0. 1 to 1. 0, which was due to the submergence of steps, a decrease in the roughness of steps and an increase in the intensity of aeration.

Owing to current status of global energy consumption and greenhouse gases emission, investigation of energy demand in different sectors seems to be necessary. Meanwhile, International Energy Agency  reports imply that a considerable share of global energy use is consumed in transport sector. Thus, conducting the vehicle energy demand and influential parameters has become a demanding topic, especially in recent years. The current study investigates the vehicle energy demand considering the power losses due to tire slip. To achieve this, vehicle resistant powers are rewritten by taking the modified tire power loss into account and after that, two different passenger vehicles are chosen and simulations are performed in three well-known driving cycles. Energy demand of the selected vehicles significantly increases in a more aggressive driving cycle which comprises higher levels of longitudinal acceleration and speed. According to the results, considering the power loss due to tire slip would improve the calculation accuracy of tire losses up to 6 percent and in case of a more aggressive driving cycle and/or increased resistant forces, energy loss due to tire slip would be increased.

This research focuses on the effect of passive methods in the field of energy storage, produce energy by using renewable energies, and also to achieve the construction patterns of residential buildings in the climate conditions of Shiraz, with the aim reducing energy consumption. Statistics show that in Iran, fuel consumption in residential and commercial buildings with an average annual growth of 7. It is about 2.37% of the country's total fuel consumption. One way to minimize energy consumption in this sector is to increase the role of zero-energy buildings. Zero-energy buildings provide technical ways to consume less energy in buildings. These buildings are designed and built so that all or a large part of these provide the energy they need through the combination of energy saving and the use of renewable energy technology. In this research, after studying the climate condition of the city of Shiraz, a building in the Energy Plus software, the simulation and climatic data of the Shiraz station was introduced to the software. To achieve the most optimal conditions of energy consumption in the climatic conditions of Shiraz, each of the building elements Residential was optimized. The simulation shows that it is possible to reduce the energy consumption of the building by using passive building materials and designs, including double-glazed glass, Wall insulation, etc. On the other hand, by using solar energy, using pvsyst software, you can supply the energy needed by the building.

Excessive consumption of energy and the production of various pollutants in the last century has caused global warming. Also, due to the increase in fossil fuel prices in recent decades and non-renewable sources, the country's annual energy consumption has become a fundamental challenge for developing countries. In Iran, energy consumption in various sectors is several times higher than global consumption, and the -building sector has the highest energy consumption. In the building sector, despite the emphasis on insulation, traditional insulation is rarely used due to its problems. A new generation of water-based paints containing silica aerogels is thermal insulators that can be used in various parts of the buildings. These insulation paints with their unique properties are a good option for insulating buildings and preventing excessive energy loss. This research investigates the effect of these paints on energy loss at different thicknesses and environmental conditions.

In the present paper, the dechanneling and the energy loss of protons at the energy interval of 1400 to 2200 keV along the {100} and the {110} planar directions of Si were studied by the simulation of the measured channeling Rutherford back-scattering spectra based on the exponential dechanneling function with a parameter λ. This parameter is proportional to the dechanneling rate and represents the mean distance that ions travel along the channel before escaping from the channel. The Levenberg-Marquardt algorithm was used to set the best values of the channeling to random energy loss ratio, and the mean channeling distance. The experimental results are well reproduced by this simulation. The data analyzed in this energy range did not show any particular trend with regard to energy dependence of the parameters. The differences between both the planar channels in the Si crystal and their influence on the energy loss ratio and dechanneling of proton ions are described.

Introduction: Due to the simplicity of construction, vertical drops are widely used to reduce the steep slope of the canal and the volume of earthworks in irrigation and drainage canals. The upstream regime of flow in structures can be subcritical or supercritical. Stilling basins are usually used to dissipate the energy and prevent the bed erosion. Due to the fact that concrete materials are used in the construction of the stilling basin, hydraulic engineers are always looking for a way to minimize the construction cost of downstream stilling basin and increase downstream energy loss of these structures. The dimensions of the downstream stilling basin depend on the geometry and hydraulic parameters of vertical drop. In the present study, the effect of serrated drop edge on energy dissipation is investigated numerically using Flow3D software. Methodology: Computational fluid dynamics is a branch of fluid mechanics that uses computers to analyze and simulate complex fluid problems. Flow-3D software is one of the most widely used software in the field of computational fluid dynamics. One of the prominent features of this software is the ability to simulate free-surface flow by Volume of Fluid (VOF) method. The governing equations of fluid flow are continuity and momentum equations. In Flow 3D software, several turbulence models are implemented. In the present study, k-ε and RNG turbulence models were used to perform the simulation. An experimental vertical drop set up with a height of 25 cm, width of 46 cm and a relative critical depth ranging from 0. 2 to 0. 35 was used for simulation. Total relative energy loss was used to validate the numerical results. Afterwards, different arrangements of dented (serrated) edge were used to simulate the flow on a vertical drop. The squared shapes in plan were used. The dimensions of dented edges which distributed symmetrically along the width were 6. 9 and 4. 6 cm (0. 15 and 0. 1 times the width of the flume) and their thicknesses were 2 cm. So, the number of dented edges was 3 and 4, respectively. In present study simulations, the total number of meshes was considered to be 1237500. According to the dimensional analysis, the relative energy loss can be expressed as equation (1): c (, , ) (1) yE T n E    = = h B u where, yc/h is the relative critical depth, n is the number of serrated edge and α is the relative Results and Discussion: The RNG turbulence model showed a better agreement with laboratory values compared to the k-ε turbulence model. The results showed that use of dented vertical drop increases the energy loss for the same relative depth in downstream, length of falling jet and the turbulence intensity compared to the simple vertical drop. In the dented model, irregularities in the streamlines of downstream increased significantly. Increasing in dimensions of the dented edges and decreasing their number caused more irregularity in streamline and augmentation of the turbulence. So, the model with 3 dented edges (relative dimension of 0. 15) performed the most turbulence and irregularity in the downstream streamlines. Energy losses in the vertical drop with 3 and 4 dented edges and ordinary vertical drop are compared. The average energy losses were 26, 38, 15 and 25 percent, respectively. Although the use of dented edges increases the length of falling jet, the stilling basin length for energy loss in the models with dented edges is less than the ordinary model. Conclusion: According to the results of the present study, the vertical drop with 3 dented edges and relative dimension of 0. 15 performs the highest energy loss as compared with the ordinary vertical drop and other models of the present study. In this study, the Froude number ranged from 3. 7 to 4. 5 in the ordinary vertical drop to 2. 7 to 2. 9. Since a stilling basin is usually constructed at the downstream of the vertical drop to dissipate the destructive kinetic energy of the flow and the dimensions of the stilling basin depends on the Froude number, so the use of dented edges in the vertical drop has such advantages as reduction in basin dimensions, augmentation in the energy loss and lower depth for tail-water to form the hydraulic jump. Therefore, considering the hydraulic and economic conditions of the design, it is possible to use the dented edges in practice to reduce the dimensions of the stilling basins and increasing the energy loss of flow in the downstream of vertical drops. Some other features and conditions are not considered in this study. So, it is suggested that the effect of angle of dented edges on energy loss and other hydraulic parameters would be investigated in future studies.