Some near-regular mechanical systems involve global deviations from their corresponding regular system. Despite extensive research on vibration analysis (eigensolution) of regular and local near-regular mechanical systems, the literature on vibration analysis of global near-regular mechanical systems is scant. In this paper, a method for vibration analysis of such systems was developed using Kr...

In recent years, TRIP/TWIP steels have been the focus of great attention thanks due to their excellent tensile strength-ductility combination. The compression tests were performed at different temperatures from 25 to1000°C to study the mechanical behavior of advanced austenitic steel with 21% manganese plus bearing Ti. The results indicated that the plastic deformation is controlled by deformat...

microstructural evolutions of twinning induced plasticity (twip) steel during tensile straining wereinvestigated by in situ sem observations. the results indicated that slip lines and mechanical twins aswell as surface relief were increased with increasing strain, resulting in a stepped surface. additionally,these deformation mechanisms could change the shape of each grain via shear and rotatio...

in this research, the high-energy planetary mill was employed to produce nanocrystalline ti-50al(γ)(at%) powders. initial powders were mechanically alloyed in 99.9999% and 90% purities of argon and also air atmosphere with alloying times up to 50h. the effect of impurity of argon atmosphere on the microstructure and the rate of phase transformation of ti-50al were investigated during mechanical...

epoxy – polysulfide copolymers without or with low amounts of epoxy in their structure have poor mechanical properties in oxidative curing system.to strengthen the mechanical properties of polysulfide elastomer inclusion of epoxy resin (epon828) as hard segment was studied. ft-ir spectroscopy and rheometry were used to verify the formation of epoxy-polysulfide copolymer.  results obtained from ...

the main purpose of this study is measuring and comparing of peanut harvesting loss in manual and mechanical methods in addition to economic analysis of them. hence, a field was selected in astaneh-ashrafiyeh and divided to three different plots. two plots were applied to measure mechanical harvesting loss and third one was applied for manual harvesting loss. according to test results, the lowe...

although cu and fe are immiscible under equilibrium conditions, they can form supersaturated solid solutions by mechanical alloying. in this paper, nano-structured of the metastable cu-fe phase containing 10, 15, 20 and 25% wt fe were synthesized by intensive ball milling for 15h, in order to achieve a solid solution of fe in cu. the phase composition, dissolution of the fe atoms into the cu ma...

conclusions the results of this study indicated that pmv predictors could be specific for each center and a good administration program is needed for each pediatric cardiac surgery center for the preoperative management of patients undergoing congenital heart surgeries. results a total of 300 patients, 56.7% male, were enrolled in this study. their mean age was 32 ± 40 months .the median durati...

results in the i-gel group, the success rate was 66.7% for placement on the first attempt, 16.7% for the second, and 3.33% for the third attempt. in the lma group, the success rates were 80.6% and 12.9% for the first and second attempts, respectively. failure in placement occurred in four cases in the i-gel and two cases in lma groups. the mean insertion time was not significantly different bet...