Journal of Mechanical Research and Application: 5 (3)

Open Access Article

1 - Rice Straw Ash-A Novel Source of SilicaNanoparticles
حمید خورسند نسیم کیایی امیرحسین معصوم پرست

In this study chemical method of dissolution-Precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (RSA), the waste material of rice cultivation. The morphology, particle size, structure and area of specific surface of synthesized amorp More

In this study chemical method of dissolution-Precipitation was applied to produce amorphous silica nanoparticles from rice straw ash (RSA), the waste material of rice cultivation. The morphology, particle size, structure and area of specific surface of synthesized amorphous silica nanoparticles were evaluated using transmission electron microscopy (TEM), X-ray diffraction analysis (XRD) and BET method. In addition, chemical composition of RSA used and the synthesized silica nanoparticles was studied by X-ray fluorescence (XRF) spectroscopy. The effects of sodium hydroxide concentration, precipitation reaction temperature and precipitation reaction duration on the area of specific surface were determined through Design of Experiments (DOE) technique. Results depicted that silica nanoparticles with particle size of 10-15 nanometers were successfully synthesized. Average area of specific surface and purity were 327 m2/gr and 99.5% respectively. The interactive influence of temperature and duration having the highest effect on the average area of specific surface. Manuscript profile

Open Access Article

2 - Nonlinear Vibration Analysis of a cantilever beam with nonlinear geometry
محمود مهدی ماشینچی ح. جوانیان جویباری د. گنجی

Analyzing the nonlinear vibration of beams is one of the important issues in structural engineering. According to this, an impressive analytical method which is called Modified Iteration Perturbation Method (MIPM) is used to obtain the behavior and frequency of a cantil More

Analyzing the nonlinear vibration of beams is one of the important issues in structural engineering. According to this, an impressive analytical method which is called Modified Iteration Perturbation Method (MIPM) is used to obtain the behavior and frequency of a cantilever beam with geometric nonlinear. This new method is combined by the Mickens and Iteration methods. Moreover, this method don’t require small parameter in the equation which is difficult to be found for nonlinear oscillation. The accuracy of the solution that is obtained by using of MIPM has been shown graphically and compared with exact solution. Comparison shows that good adaptation is obtained and MIPM is a powerful method for solving the vibrational behavior of structures analytically. Manuscript profile

Open Access Article

3 - Design and Experimental Analysis of Aircraft Air Distribution Systems
محمدرضا افقری محمد ابوالحسنی مقدم علی ضیایی

In this paper, the methodology of aircraft air distribution system has been analyzed theoretically and experimentally. To achieve that, ducting pressure loss and air flow throw gaspers calculations has been done for cabin ducts in according to exact location of individu More

In this paper, the methodology of aircraft air distribution system has been analyzed theoretically and experimentally. To achieve that, ducting pressure loss and air flow throw gaspers calculations has been done for cabin ducts in according to exact location of individual air distribution system in the cabin. The length of gasper air flow was compared with the distance between gasper outlet and passengers seats and the velocity of the gaspers has been measured with velocity gage on the mockup. Finally design results show good agreement between air flow throw gaspers and gasper to passenger distance that make comfortable air feeling conditions. Also the experimental analysis on the mockup validates results of outlet velocity of gaspers and perforations calculations. Therefore the validity and feasibility of design methodology of installation gasper system to a cabin air distribution system for least modifications, suitable location and efficient air flow throw gaspers is confirmed. Manuscript profile

Open Access Article

4 - Heat Conduction in Spherical Composite Vessels
م. نوروزی ا. امیری دلویی م. سلیسپور

This paper presents an exact analytical solution for two-dimensional conductive heat transfer in spherical composite pressure vessels .The vessels are in spherical shape and fibers are winded in circumferential direction. The analytical solution is obtained under the ge More

This paper presents an exact analytical solution for two-dimensional conductive heat transfer in spherical composite pressure vessels .The vessels are in spherical shape and fibers are winded in circumferential direction. The analytical solution is obtained under the general boundary conditions which consist of convection, conduction and radiation inside/outside of vessel. The heat transfer equation for orthotropic conduction in spherical coordinates is derived and solved using separation of variables method based on the Legendre and Euler functions. Here, the effect of fiber's angle on heat diffusion in orthotropic spherical pressure vessels is investigated in detail. These results can be used extensively for analyzing the thermal stress in this kind of vessels. Manuscript profile

Open Access Article

5 - Evaluation of Acoustic Emission Inspection of Oil Tank Floor via Tank Bottom Plates Thickness Measurement
ا. هدایی م. جوادی ا. برومندنیا ح. صادقی

This paper deals with an inspection of defects including corrosion and leakage by Acoustic Emission (AE) in an oil tank floor. In contrast to intrusive methods such as magnetic flux leakage, eddy current or ultrasonic, there is no need to emptying and entering the tank More

This paper deals with an inspection of defects including corrosion and leakage by Acoustic Emission (AE) in an oil tank floor. In contrast to intrusive methods such as magnetic flux leakage, eddy current or ultrasonic, there is no need to emptying and entering the tank in AE method in order to inspection. In this research AE investigation and AE source location is presented in detail. The result of AE test in the studied oil tank verifies the presence of corrosion in some areas of the tank floor. After AE test, the tank emptied and inspected using ultrasonic thickness meter. The result of thickness measurement reconciles in an acceptable manner with AE test. Manuscript profile

Open Access Article

6 - Effect of surface roughness on steel-steel dry friction coefficient
ح. چارستاد س.م خورسندی جو

The influence of surface roughness magnitude and direction on dry static friction coefficient between two similar steel samples has been studied through an experiment. A testing apparatus has been designed and fabricated to measure the friction coefficient for a few for More

The influence of surface roughness magnitude and direction on dry static friction coefficient between two similar steel samples has been studied through an experiment. A testing apparatus has been designed and fabricated to measure the friction coefficient for a few forms of surface asperity. According to the results of the experiments, dry friction coefficient is affected by both magnitude and direction of surface roughness. Manuscript profile

Open Access Article

7 - Using Gray Relational Analysis and Taguchi Technique in Solving Multi-objective Problems for Turning Operation of Austenitic Stainless Steel
م. آزادی مقدم ف. کلاهان م. حسینی دوغ آبادی

In this study, the application of gray relational analysis (GRA) and Taguchi method in multi-criteria process parameters selection of turning operation has been investigated. The process responses under study are material removal rate (MRR) and surface roughness (SR); i More

In this study, the application of gray relational analysis (GRA) and Taguchi method in multi-criteria process parameters selection of turning operation has been investigated. The process responses under study are material removal rate (MRR) and surface roughness (SR); in turn, the input parameters include cutting speed, feed rate, depth of cut and nose radius of the cutting tool. The proposed approach employs GRA to convert the values of process outputs, obtained from Taguchi method, into a single objective used to determine the best set of process parameters for turning operation of AISI 202 austenitic stainless steel. Analytical results reveal that the combination of higher levels of cutting speed, depth of cut, and nose radius and lower level of feed rate is essential to achieve simultaneous maximization of material removal rate and minimization of surface roughness. Using verification test, these settings would result in more than 14% improvement over those for initial settings. The analysis of variance (ANOVA) and F-tests showed that nose radius is the major factor affecting the gray relational grade (GRG) with 41% contribution. In general, the proposed procedure is quite efficient in determining the effects of process parameters and finding the best set of process parameters. Manuscript profile

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