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Aims: Inefficient outdoor airflow of residential complexes is one of the most important issues that has greatly reduced thermal comfort and, consequently, the tendency to be present in these spaces. The present study aims to investigate the effect of the arrangement of blocks in a residential complex in Tehran on the outdoor wind flow and received natural light by the buildings.
Methods: The research method is descriptive-analytical with the application of Design builder 6.1.2.009 and CFD (Ansys Airpak 16.0.3) software, respectively, to simulate and investigate the effect of changing the arrangement of residential blocks on wind flow pattern and airflow potential. It is used around the buildings and the amount of natural light received by the building.
Findings: The analysis of the simulations indicated that the modification of distance and arrangement along the X axis (in the best case caused) caused a %7.10 increase in wind speed, and a %2.35 increase in the amount of daylight received by buildings compared to the base model. Moving the blocks along Y axis, in the optimal state caused a %3.55 increase in wind speed and %2.48 increase in the amount of received natural light compared to the base model.
Conclusion: The results of the study indicated that uniaxial displacement of blocks may have positive or negative effects on outdoor airflow, while combined displacement patterns decrease air velocity. Uniaxial and hybrid displacement increases received daylight in comparison to the base mode.

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Aims: The educational system is one of the key areas affected by the COVID-19 pandemic. Due to their sensitive nature, medical schools and health-related disciplines have been more significantly impacted by COVID-19. Therefore, aggregation and integration of educational policies applied in medical schools worldwide are essential for evidence-based decision-making by educational policymakers—the present study aimed to identify virtual learning policies in medical schools during COVID-19.
Information & Methods: This systematic review of all published articles on virtual education policies in medical schools during COVID-19 until January 20, 2022, collected from five databases and the Google Scholar search engine. Overall, 38 articles are identified and analyzed using content analysis in MAXQDA 10.
Findings: The results are classified into three domains: Challenges, solutions, and advantages of virtual learning of medical sciences during COVID-19. Thirty-four challenges, 62 solutions, and 27 advantages are identified. Each domain is divided into five categories: learner, teaching-learning process, technical infrastructure, instructor, and evaluation.
Conclusion: Distance education policies need to identify the challenges of this type of education and apply a systemic model of interventions that include virtual clinical workshops, clinical simulation laboratories, flexible online resources, a gradual e-learning process, a system for sharing the virtual materials of instructors, and ways of improving students’ and instructors’ computer skills.

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Egyptian broomrape Phelipanche aegyptiaca is a parasitic weed that infests its hosts and feeds on the sap, significantly impacting crop yields. This experiment aims to control the Egyptian broomrape in its seed germination stage and reduce the damage to tomatoes. Fertilizer treatments included urea, ammonium sulfate, and ammonium nitrate at the rate of 150, 250, and 300 kg h^-1 respectively, which were applied in three divided stages. Organic herbicide, before transplanting at the rate of six per thousand, and the humic acid plus phosphorus at the rate of two and 60 kg ha^-1 in two stages were used in wet soil using calibrated backpack sprayers equipped with a nozzle. Also, four applications of sulfosulfuron (Apiros^®, 75% WG) at the rate of 35 g ha^-1 at intervals of 30, 40, 50, and 60 days after planting seedlings, and not weeding the Egyptian broomrape (broomrape-infested tomato) were among the other treatments in the experiment. The results revealed that the effect of experimental treatments on the studied traits of tomato and Egyptian broomrape was significant. Application of four stages of sulfosulfuron increased fruit number per plant and yield by 41% and 77%, respectively, compared to the weed-infested control. Herbicide application reduced Egyptian broomrape density by 89% per tomato plant compared to the weed-infested control. Applying sulfosulfuron and humic acid plus phosphorus reduced the dry weight of Egyptian broomrape by 78% and 69%, respectively, compared to the weed-infested control. Also, the relationship between the studied traits in Egyptian broomrape and tomatoes was inconsistent and significant. Based on our results, four applications of sulfosulfuron was recognized as the most effective in reducing the morphological characteristics of Egyptian broomrape and increasing tomato yield in the field. Also, applying two stages of humic acid plus phosphorus effectively reduced broomrape’s adverse effects and increased tomato yield.

 

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Correct place and order of adjectives is one of the important factors affecting the correct translation of a word or a phrase. Not paying attention to the adjective order can completely change the meaning of a sentence or a phrase. In this study, based on 320 examples collected from Russian-Persian dictionaries and the Russian National Corpus, The authors attempt to consider and compare the order of adjectives in Russian and Persian languages. In the present study, we are trying to answer the following  questions : how is it possible to explain and describe the rule for adjective order in Russian language and is there a certain and constant model for their translation from Russian to Persian. The results of this study can be efficient for the improvement of the translation process as well as the training of translation from Russian to Persian and vice versa. The analysis of the collected examples indicates that only in half of the cases the order of adjectives in Russian and Persian languages is fully compatible, and in the other cases their translation from Russian to Persian does not follow a constant model.
Paying attention to the rules of word order is one of the important issues when learning Russian language. Having a rich vocabulary by itself cannot be effective in correctly expressing of sentences. In many cases, when you change the place of words in a sentence, the meaning is changed completely as well.
 The position of various adjectives in relation to each other and in relation to the modified word in a sentence or phrase, as well as the preservation and transfer of this order when translating into Persian, is one of the main problems of non-native students and translators.
In this study, based on 320 examples collected from Russian-Persian dictionaries Voskanyan, G. A., Ovchinnikova, I. K. Mirzabeigyan Zh. M. and the Russian National Corpus, the authors attempt to consider and compare the order of adjectives with focus on the modified word in Russian language and the way of their translation and transfer to Persian language. So far, no study has examined the order of adjectives in Russian and Persian language in a comparative manner.
The aim of the present study is to provide a specific rule for the order of adjectives in Russian, as well as to study and compare the degree of correspondence or inconsistency of this order when translating into Persian.
The analysis of the collected materials shows that in the Russian language adjectives come before a noun, pronominal adjectives are used before qualitative and relative adjectives and qualitative adjective comes before relative adjective. In cases where a phrase consists of two relative adjectives or two qualitative adjectives, the closest adjective to the noun expresses the attribute of the noun more than the others.  Also, the analysis of the collected translation examples indicates that only in half of the cases the order of adjectives in Russian and Persian languages is fully compatible, and in the other cases their translation from Russian to Persian does not follow a constant model. The results of this research can be effective in improving the process of translation and teaching it from Russian to Persian and vice versa.

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     This article examines the poverty rates for urban and rural areas of Kermanshah and the entire country using a Linear Expenditure System (LES) and Iterative Seemingly Unrelated Regression (ISUR) method during 1995-2007. Results indicate that poverty in rural and urban areas over the years in this province has an upturn trend. The findings also suggest that in rural and urban areas of Kermanshah, the group "foods" have biggest share of the poverty line. In rural areas of the country group "foods" have also the biggest share of the poverty line, but the largest share in country's urban areas belongs to group of "Housing and fuel". About elasticity the results show that in both urban and rural areas the group "other" and "appliances and furniture" are luxury.

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Aims: The purpose of this study is to investigate the role of vegetation in reducing nuisance wind speed on the Imam Street sidewalk. Imam Street is one of the main arteries in Tabriz, and the nuisance wind speed on its sidewalks disturbs the climate comfort for pedestrians, especially during the cold season.

Methods: A descriptive-analytical method is used in this study, and numerical simulations are performed using Dlubal RWIND 2.02 to evaluate the wind flow for the current condition and the proposed alternatives. In this context, the effect of vegetation height, spacing and arrangement (with tree bench) as independent variables on wind speed at pedestrian height as dependent variable was investigated. Spearman correlation test is used to evaluate the relationship between variables.

Findings: The studies have shown that trees with a height of 4 meters, distributed at a distance of 5 meters according to the pattern 1, can reduce the flow velocity on the pedestrian level by 52%.

Conclusion: The results show that the implementation of vegetation in appropriate spacing and pattern can significantly reduce wind speed. Placing tree benches on the sidewalk changes the airflow toward the street and reduces wind speed at the pedestrian level.
 

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The experiment was conducted to determine α-amylase activity and the effect of seven plant species extracts including Punica granatum L. (Punicaceae), Rheum officinale B. (Polygonaceae), Rhus coriaria L. (Anacardiaceae), Artemisia sieberi B. ( Compositae), Peganum harmala L. (Nitrariaceae) , Datura stramonium L. (Solanaceae) and Thymus vulgaris L. (Lamiaceae) on α-amylase activity of four stored insect pests including Callosobruchus maculatus F. (Coleoptera: Bruchidae), Rhyzopertha dominica F. (Coleoptera: Bostrichidae), Sitophilus granarius L. (Coleoptera: Curculionidae), and Trogoderma granarium E. (Coleoptera : Dermestidae). Also, gut pH and optimum temperature for α-amylase activity of these insects were determined. It was found that α -amylases midgut pH of all four insect species was acidic and optimum temperature was between 30 and 40 °C. Beyond these temperatures, the α-amylases activities sharply decreased. Plant extracts caused inhibitory activity on insect α-amylases varying from nearly 4% to 95% inhibition. D. stramonium and R. officinali extracts had the highest amylase inhibitory activity among the tested extracts, while methanolic extracts of P. harmala, and T. vulgaris (except for S. granaries α-amylase) showed the lowest inhibitory activity. Gel assays revealed that more than one isoform of α -amylase detected in midgut crude extracts of the four insect pests examined could be inhibited by the plant extracts.

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Gastric cancer is one of the most common cancers in the world. Its treatments are costly and can cause severe side effects. As a result, treatments with natural compounds, well-established therapeutics, or combinations of both groups may be effective alternatives. p-Coumaric acid (pCA) and metformin (Met) are among such anticancer treatments. Epithelial-mesenchymal transition (EMT) is a multi-purpose process that plays a critical role in gastric cancer. This process involves a complex network of biological markers participating in gastric cancer initiation and metastasis. Subsequently, the agents downregulating the expression of EMT markers may be potential anti-gastric cancer therapeutics. Because the effects of pCA, Met, and their combination on the expression of EMT markers ZEB1, Snail2, Vimentin, and VEGFA have not been inspected, the present study aimed at assessing these effects. MTT assay determined the cytotoxicity of pCA and Met on the AGS cells for 48 hours. Real-time PCR was used to evaluate the changes in the expression levels of these EMT genes after 48 hours. A combination of pCA and Met downregulated the expression of ZEB1 and Vimentin genes at low, non-cytotoxic concentrations. Therefore, they may be potential candidates for further investigations in fighting against gastric cancer.
 

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AISI 4340 steel is a low alloy steel with high tensile strength that has numerous applications in industry. Machinability of this alloy steel has difficulties due to its low heat conduction and high heat concentration in cutting zone. Therefore, use of cutting fluids in machining of this steel is inevitable. On the other hand, environmental problems of using mineral lubricants lead industries into use of biodegradable oils such as Vegetable based cutting fluids. The aim of this study is to investigate the drilling of AISI4340 alloy steel in presence of semi-dry lubricant and using soybean vegetable-based oil. For this purpose, drilling parameters including feed rate and cutting speed at three levels and workpiece hardness at two levels were chosen. Totally 18 experiments were carried out using coated carbide drill. Results revealed that vegetable-based oil can effectively be used in drilling using a semi-dry lubrication method. In addition, feed rate was the most effective parameter on cutting force and surface roughness and by increasing it, the cutting force increased, and the surface quality deteriorated. Also, workpiece hardness showed significant effect on surface roughness.

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AISI4340 hardened steel have a vast functionality in industries. Hard machining of this steel have several benefits such as, higher productivity, lower production cost and improved workpiece properties. In machining operation, ultimate surface roughness is the most important characteristic of machined surface and plays an important role in workpiece life. One of the effective factors on surface integrity is cutting fluid used in machining operation, which have health and environmental problems is spite of positive effects. As a result, using minimum quantity lubrication is considered as an alternative method. In present study, relations between milling parameters and final surface quality in milling of AISI4340 hardened steel, in the presence of lubrication systems including; dry, wet and minimum quantity lubrication have been investigated. Cutting speed, feed rate, axial and radial depth of cut have been considered as main parameters of milling operation. Totally, 90 experiments have been done using response surface method to analyze the effects of process parameters on surface roughness. Results revealed that feed rate and cutting speed have the most Influences on surface roughness. Also higher values of cutting speed and lower values of feed rate are necessary to reduce surface roughness. In addition, compared to other lubrication methods, minimum quantity lubrication have the best performance in surface quality, especially in high cutting speed and depth of cut.

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The productivity of a part is assessed based on factors such as dimensional and geometrical tolerances. In fact, tolerance features are the most important factors in shop drawing of an industrial part. The aim of present study is to empirically investigate the precision of holes created by helical milling method on AISI 4340 alloyed steel. This method refers to create the hole using milling tool, which moves along a helical path. By using helical milling, a high quality hole has been produced and there is no need for boring. Taguchi design of experiment was used to study the effects of process parameters including; cutting speed, feed rate, axial depth of cut and workpiece hardness on dimensional and geometrical tolerances of created hole. In addition, effect of minimum quantity lubrication method with two different oils and dry milling methods was studied. Results showed that the helical milling can be a suitable replacement for conventional drilling. In addition, cutting speed as the main parameter had significant effect on quality improvement of the created hole. On the other hand, in the helical milling, minimum quantity lubrication method using vegetable-based oil showed the best performance compared to mineral oil or dry cutting.

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Helical milling has been known as an innovative method for making high quality holes. In this method, milling tool generates efficiently a high quality hole by moving along a helical path. The hole diameter can be adjusted through the diameter of this helical path. Regarding accuracy of hole in industrial parts, it is necessary to compare this method with conventional hole drilling. Therefore, in this study helical milling and conventional drilling, have been compared with each other. Eight experiments were conducted considering two levels of cutting speed and feed rate on the samples made of AISI 4340 steel at 45 HRC. Minimum quantity lubricant system with two nozzles was used. 100 ml/h of Behran-11 mineral oil at air pressure of 4 bar was employed in this system. Machining forces, surface roughness, nominal diameter, roundness, and cylindricity were output parameters. According to the obtained results, cutting speed was the only one with positive effect on all qualitative parameters of the machined holes. On the other hand, independency of cutting parameters, helical milling lessened machining forces, surface roughness, and geometrical tolerances in compare with conventional drilling.

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This article investigates energy absorption capacity and plastic deformation of lateral flattening process on an aluminum profile with special cross-section under the lateral compressive loading in the quasi-static condition by experimental method. The profile section is a circular tube with two symmetric longitudinal grooves. Different samples with various lengths and outer diameters in three different filling conditions consist of empty, core-filled and full-filled by polyurethane foam were prepared. Some specimens with the same geometry and filling condition but, with different loading angles of 0, 30, 45, 60 and 90o respect to symmetric line of two longitudinal grooves, were laterally compressed. Effects of various parameters such as profile length, outer diameter, three different filling conditions, and loading angle are investigated on lateral loading and specific absorbed energy. Experimental results show that specific absorbed energy is independent of specimen length. At the same displacement, when diameter of samples increases compressive loading decreases. Also, in zero loading angle, presence of the filler enhances lateral load; and consequently, increases specific absorbed energy by the structure. In viewpoint of the design of an energy absorber design, optimum specimen is full-filled profile under a loading angle equal to zero. However, if due to some design limitations, assembling the special profile with loading angle of zero is impossible, assembling the structure in empty condition with loading angle of 90o can be the next suggestion. Experiments show that the highest specific absorbed energy occurs in the profile with different diameters under loading angles of zero and 90o.

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Nowadays, using the double skin facades has attracted the attention of many engineers because of its significant effects on the buildings’ energy consumption. The previous researches have shown that the double skin facades have an appropriate thermal performance in the cold season. However, using double skin façade may lead to increase the building’s energy demand in the warm season. Therefore, in the recent years, the idea of using double skin facades with phase change materials (PCM) has been proposed in order to decrease the summer energy consumption of buildings. In this study, a thermal performance analysis has been performed by considering a high-rise building with the phase change material double skin façade in Tehran climatic conditions. The results indicate that although using the ordinary double skin façades can decrease the building’s energy consumption up to 20% in cold months of the year; it can lead to increase the summer cooling load about 4.6%. However, by using double skin façades with the phase change material glazing, the building’s energy consumption in cold and warm seasons may decrease about 40% and 26%, respectively.

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Vortex combustion chamber is the new generation of liquid propellant engines chamber, where with the help of different arrangement of injectors, an inner combustion chamber vortex flow is created. This vortex can extremely help cooling and increasing the amount of propellant components mixing in the combustion chamber so it makes it possible to create a complete combustion in a low- capacity chamber. In this research, a vortex chamber has been designed and manufactured for carrying out cold tests with water as its working fluid, in order to study impact of different parameters, including pressure drop, injector quantity and input angle, chamber diameter and the thickness of the supporting step, on the performance of this type of chambers. The designed chamber, has a great deal of capabilities such as replacement ease, change in pressure drop and injectors’ input angle and studying different supporting step’s thickness to create vortex flow. Since practical investigation of all parameters is not cost-effective, cold test has been conducted for some samples and both simulation and validation have been done for it. The simulation results and chamber performance in the tests could match very well; therefore as a result of simulation assurance, the processes and other parameters in the chamber could be studied. By doing these tests we can move toward design, manufacture and test of the main vortex combustion chamber.

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In recent years, many studies have been done to fabricate superhydrophobic surfaces. These surfaces have slip condition which cause self-cleaning property and also drag reduction. The hierarchical micro/nanostructures which are coated with a low surface energy material are needed to fabricate high static contact angle superhydrophobic surfaces. In order to have thermal stability, chemical resistance and low surface energy Polytetrafluoroethylene (Teflon) is used in this research. To produce the superhydrophobic surface, an appropriate layer of Teflon is coated on the aluminum substrate and the micron sized aluminum particles are deposited on the Teflon layer by fluidizing method. Then to reduce surface energy, the second Teflon layer is sprayed on the top of the aluminum particles. At the end using sprayed method the hydrophobic nano-particles of silica are deposited on the surface as a final hydrophobic layer. The effect of Teflon thickness, size of micro-particles and adding hydrophobic nano-particles are investigated. The scanning electron microscopy (SEM) images of the cured surfaces show that application of micro-particles, prevent surface to be smooth after curing, create appropriate micro-scale structures and also cause micro-scale cracks compared to smooth Teflon surfaces. The creation of these micro-structures leads to increasing in static contact angle and decreasing in dynamic angle of surfaces. By modifying the surface structures with aluminum micro-particles, Teflon layer coat and subsequent deposition of hydrophobic silica nano-particles, static contact angle of 165±3° and dynamic angle of less than 7 degrees are achieved.

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This article presents a numerical investigation of fluid flow in one of the centrifugal pumps of pump-Iran Corporation. A computational fluid dynamics (CFD) analysis is performed by using the CFX software for a wide range of volumetric flow rates for two different rotor speeds of 1450 rpm and 2900 rpm and the numerical results of water are validated against measured values of head and total efficiency with an overall acceptable agreement. The obtained results have been obtained for crude oil as diagrams of head and total efficiency as the function of volumetric flow rate and other variables and compared with results of water. Numerical results show that the absolute pressure on blade surfaces for crude oil is 705 kpa less than when using water. The absolute pressure difference between inlet and outlet of impeller and spiral volute for crude oil is comparatively less than those amounts in comparison with water. Also by increasing the angular velocity of rotor, it was observed that high levels of turbulence intensity are transmitted from outlet pipe bending to the impeller outlet at volumetric flow rate of 30 m3/h that causes the efficiency reduction and high levels of turbulence intensity for crude oil are less than those amounts in comparison with water within impeller area. Finally, to represent an impeller pump head curve for crude oil over the overall operation range of the pump, a second order polynomial equation was fit to numerical data.

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Superhydrophobic surfaces are the surfaces with self-cleaning behavior due to surface slip condition. This property is applicable to produce drag reducing, anti-corrosive, and anti-fouling surfaces. Superhydrophobic coatings have been vigorously researched through numerous physical and chemical approaches, including lithography, self-assembly, electrospinning, chemical vapor deposition, plasma or chemical etching, and sol−gel techniques, and so forth. The large-scale fabrication of these surfaces is a challenging issue that restricts employment of these surfaces in industrial applications. Hydrophobic coating of micro/nano particles and deposition of the particles on the surface is a solution that facilitates large-scale fabrication of superhydrophobic surfaces. In this study, rotational vapor phase deposition and immersion method are used to fabricate hydrophobic aluminum flakes. Two reaction times are investigated and the results of two coating method and two particle sizes are presented. The results show that vapor phase deposition method is efficient as well as the immersion method while the latter is not cost effective. Stability test of the prepared samples showed that particle sizes are important in the vapor phase coating and the reaction time of 6 h is better than the 12 h.

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Vibration due to train movement has been concerned since the advent of rail transportation systems. Nowadays this subject is more important by increasing the speed of trains and wagon weight and development rail way in urban area. Different methods and techniques have been proposed to reduce these vibrations by researchers. In this study, geotechnical modeling of trench barrier isolators to reduce train vibrations are investigated by numerical modeling. Trench barrier according to location are divided into two categories: active and passive. Active trench is located near the source load but passive trench is located near the structure that needs protections. The main focus of this research is the effects of trench depth on efficiency of passive trench barrier. In advance by considering the wagon weight and distance between the wheels, the load in terms of time domain by calculating Fourier spectra and considered effective frequency range, the load-time function is determined. Then, a series of nonlinear finite-element analyses were carried out to study effect of trench depth. The depths of trench are considered 0 to eight meters in analysis. Viscous damping was considered by means of Rayleigh methods. The coefficient of mass and stiffness matrices are defined by modal analysis. Then, modeling of rail, sleeper, ballast, sub-ballast and soil layers is conducted to analyze wave vibration propagation due to train movement and evaluation of amplitude reduction due to trench barrier. Mohr Coulomb failure criterion is supposed for soil, ballast and sub-ballast layer and a linear elastic behavior was assumed for sleeper. Infinite element boundaries were used at the lateral sides of the finite element mesh for prevention of wave reflection. The dynamic response analysis was based on input time historical wagon load which determined in previous section applied at the sleeper.Thereby the studying of deformations and displacement and particle velocity of the elements of the model, the effects of the trench barrier on before and after trench, are considered. Results indicate that increase in trench depth is effective on vibration reduction. This means that by increasing the depth of the trench, amplitude of deformation becomes more reduced. It also increases the depth of the trench, reduces the dominant wave frequency vibrations. On the other hand, by increasing the depth of the trench, amplitude reduction ratio has a significant decreasing that means increase efficiency trenches. The relationship between depth and amplitude reduction ratio (Arr) was introduced as a quadratic function. For validation of modeling, theory equation of amplitude decreasing is compared with numerical modeling. The result showed that there is a good accordance between numerical model and theory equation at different distance.The minimum depth of the trench should be selected based on different parameters. To define depth of trench should be note that the reduction due to trench should be significantly greater than the decreasing wave amplitude due geometric and material damping. Reducing the required to mitigate the potential damage of protected structures and economic and implementation considerations are important factor in determination of final depth of the trench barrier isolator.

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In this paper the methodology of reliability analysis in aerial structures has been developed. This methodology has been carried out on a special specimen. The selected specimen is a cylinder strut of the landing gear system of a training airplane. This specimen is one of the most important part of the landing gear system. Because of it’s special shape, there is no analytical solution for calculation of stress in it. Therefore, by means of the surface response method and Box-Behnken tables, a deterministic equation for calculating the stresses in critical points of the specimen has been produced. Then in order to obtain the reliability of this part via probabilistic method, Monte Carlo simulation has been used. The applied loads have been modeled whit one pressure, one bending moment and one concentrated force. These loads have been assumed to be independent random variables. Also, the probability distribution function of the pressure and the bending moment have been assumed to be normal and the probability distribution function of the concentrated force has been assumed to be lognormal. The dimensions of the specimen is deterministic and the mechanical properties of the material is a normal distribution with standard deviation equals to be 10 percent of its mean value. The results showed that the minimum reliability of this specimen is 99.9997 percent. So, the design of the cylinder strut is safe for aerial applications in reliability viewpoint.