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In end milling operation, cutting forces induce vibration on tool, workpiece and clamping devices which affects surface integrity and quality of the product. In this process, to select the optimum end mill and machine tool, the prediction of exact cutting forces is of prime importance. In the present work, modeling and simulation of cutting forces in end milling operation are performed. Instantaneous chip geometry is predicted using a 3D simulation software, the effect of cutting depth and feed rate are calculated and cutting conditions are predicted before any machining operation.

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In certain applications, it is improtant to measure the mechanical properties of steel with high accuracy. These properties are usually measured by destructive methods. However, the small changes made during heat treatment processes are not usually detectable by destructive methods. Ultrasonic non destructive testing is an alternative method that can be used for measuring the mechanical properties of steels. In this paper, the ultrasonic method has been used for measurement of meachanical properties of AISI D6 steel samples processed by various heat treatment processes. Each sample has a differnet micro stucture and hardness due to its specific heat treatment. To find the meachanical properties, the velocity of longitudinal and shear ultrasonic waves were measured for each sample. Comparison of the results obtained from ultrasonic measurements with those available in reference tables shows that the ultrasonic non destructive method can measure the elastic properties of AISI D6 samples with high accuracy.

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Objective: This study was designed to investigate the antinociceptive effect of chronic administration of the flavonoid hesperetin in streptozotocin-diabetic rats using formalin and hot tail immersion tests. Materials and Methods: Rats were divided into 5 control groups, hesperetin-treated control, diabetic, sodium salicylate (SS)-treated diabetic, and hesperetin- and glibenclamide-treated diabetic groups. Hesperetin (10 mg/kg) was administered i.p. one other day 1 week after diabetes induction for 6 weeks. Finally, thermal pain tolerance and nociception were evaluated using hot water tail immersion and formalin tests respectively. Results: Diabetic rats exhibited a higher score of pain at both phases of the formalin test (P<0.05) and hesperetin-treated diabetic rats exhibited a lower nociceptive score at both phases of the test (P<0.05). Regarding thermal pain tolerance, diabetes significantly reduced tail immersion latency (P<0.01) and hesperetin treatment did produce a significant change in this respect (P<0.05). Conclusion: Chronic treatment with hesperetin for 6 weeks does mildly increase thermal pain tolerance and reduces chemical nociception in an experimental model of diabetes mellitus and this may be considered as an auxiliary treatment for diabetic hyperalgesia.

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In this research, the effects of cutting parameters on material removal rate and surface roughness, are investigated. Therefore, after that the comprehensive model of low-immersion milling is developed, the optimum cutting conditions has to be found for optimizing all of them. The stability criterion is considered as the optimization constraint which is calculated by TFEA. On the other hand, instead of using explicit equation for calculating surface roughness, such as previous works, surface roughness is calculated by TFEA for all of the cases that are needed. Finally, the ability of Genetic algorithm, Particle Swarm Optimization and Imperialist Competitive Algorithm for searching optimum cutting parameters are compared and the results are reported. By comparing the results of the three algorithms it is shown that the ICA is more powerful to deal with nonlinearity aspects of the problem and to tackle sticking in local minimums. Also it is demonstrated that the convergence rate of the ICA is faster than the other two methods. Finally, experiments to confirm the changes of the objective function toward optimal point are done and error percentage of objective function at obtained optimal point compared with experimental result is determined.

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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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ََAbstract Recognition of the dynamical behavior and vibrations of marine structures, submerged in vicinity of the water free surface, is one of the most important issues in design of the marine structures. It is obvious that physical properties of the ambient fluid have some influences on vibrational frequencies of the structures. For the structures that have exposed under the influences of asymmetric environmental conditions, prediction of their dynamical behaviors is more complicated. In this paper the effects of immersion depth on first natural frequency of a bounded circular plate that was placed parallel in vicinity of the water surface, are studied numerically and experimentally. Based on the author’s knowledge, the techniques used for exciting the plate and measurements of natural frequencies are innovations of this research. Numerical solutions are done by using of the ABAQUS software. Comparisons of the numerical and experimental results show a good consistency. The investigations showed by increasing of the immersion depth, so the ratio of the depth to plate diameter reached to a certain value, the natural frequencies were also decreased. After that it remained constant while the immersion depths of plate were increased.

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The use of chemical compounds to prevent corruption and increase the shelf life of agricultural products, including grapes, has many applications. Due to the harmful effects of these compounds on human health and also the tendency of people to use organic products, today the use of low-risk and alternative methods has increased. The use of antimicrobial, antibacterial and antifungal compounds, such as natural essential oils, can be a good way to increase the shelf life of crops. In this study, the effect of thyme essential oil on increasing the shelf life of Fakhri cultivar grapes by two methods of immersion (direct contact) and fumigant (indirect contact) in concentrations (0, 150, 300 and 450 μl / l) In the cold storage with a temperature of 1±2° C and a relative humidity of 90% was tested for 60 days. Traits such as percentage of changes in fruit weight, titratable acidity, total soluble solids, sensory evaluation including fruit texture firmness, Smell and flavor, antioxidant capacity and browning of cluster wood were evaluated. The least percentage of changes in fruit weight and titratable acidity were observed at a concentration of 450 μl /l of thyme essential oil. The control treatment had the highest amount of total soluble solids in fruits (25.2 degrees Brix). Also, the results of sensory evaluation of fruit texture firmness showed that the fumigant method was better than the immersion method with gradual release of essential oil to maintain the firmness of fruit texture better. Sensory evaluation of grape fruit Smell and flavor and taste showed that at high concentrations of essential oil, the sensory evaluation index was lower. Antioxidant capacity was declining in the whole process and fumigant and immersion methods were not significantly different from each other.

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Slurry casting method is a novel process to produce metal forms, which makes it possible to produce a porous structure with open cell. In the present study, the microstructure and compressive behavior of aluminum foams produced by slurry casting method, under different number of immersion times were investigated. For the production of aluminum foams with different cell sizes, polyurethane preforms with characteristics of 45, 55 and 65 ppi were selected, and after immersing in a slurry having a solid mass of 88% and removing the excess semiliquid mixture, the samples were sintered at 630˚C. The size of polyurethane perform cell as well as the number of immersion times control the microstructure and compression performance of porous structures. The results of the study showed that the portability of porous aluminum increases by decreasing the size of preform cell or increasing the number of immersion times, which leads to thicker strut. In addition, the probability of crack existence, exactly at the corner of structures, decrease via enhancing the thickness of strut. Meanwhile, excessive increase in the number of immersion, i.e. third times, was associated with some closed-cells which results in strain localization and stress concentration. Therefore, the maximum plateau stress as well as the superior energy absorption capacity was observed in the sample having the minimum preform pore sizes which was immersed for two times in the aluminum slurry.

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In this paper, the non-linear dynamic behavior of immersed AFM micro cantilever in liquid has been modeled. To increase the accuracy of the theoretical model, all necessary details for cantilever and sample surface have been taken into account. As for the theoretical model, the Timoshenko beam theory which takes the rotatory inertia and shear deformation effects into consideration has been adopted. For modeling the vibrational system, cantilever thickness, cantilever length and breadth, the angle between cantilever and sample surface, normal contact stiffness, lateral contact stiffness, tip height, breadth taper ratio, height taper ratio, time parameter and viscosity of the liquids have been considered. Differential quadrature method (DQM) has been used for solving the differential equations. During the investigation, the softening behavior was observed for all cases. Here, water, methanol, acetone and carbon tetrachloride has been supposed as immersion environments. Results show that increasing the liquid density reduces the resonant frequency. Time variable does not have any considerable effect on the non-linear resonant frequency. Theoretical modeling has been compared for a rectangular AFM cantilever with experimental works in both of the contact and non-contact modes in air and water environments. Results show good agreement.