Vibration Simulation of the cylindrical reservoir shell containing fluid vortex with the help of Vib-Shape software

This paper addresses the simulation of the vibrational behavior of a flat-bottomed cylindrical reservoir in different levels of fluid vortex with the help of Vib-Shape software. The reservoir is equipped with a mixer, which creates fluid vortex and required loading. The compliance of the shell vibration mode shape of the mentioned model obtained from the collected data and simulation in the aforementioned software is compared with the mode shapes derived from the Donnell‘s theory. The results are in the good agreement with the governing theories of the problem

SiC and ZrO2 Weigh Percentage Effects on Microstructure of Al Based Matrix Composite Fabricated by Spark Plasma Sintering Method

SiC and ZrO2 particle are succesfully reaction synthesized from powder of Al, ZrO2 and SiC using spark plasma sintering method. The XRD of sintered composite and microstructure of the aas-sintered products. With the ZrO2 content increasing, the grains are remarkably refined and the and the ZrO2 and nano SiC particles are dispersing more uniformly in Al matrix, forming a homogeneous structure with the least porosity

Measurement the effects of temperature and fiber orientation on vibration of functionally graded beam

This paper concerned with analytical approach to study the thermal vibration of fiber orientation functionally graded (FOFG) beam, that fibers`oriented angles are variable and graded in the thickness direction of the beam. Uniform thermal distribution considered in the entire beam and properties of fiber orientation functionally graded (FOFG) beam considered as the temperature-dependent element. Symmetrical, asymmetrical, and classical distribution types for the mode of fiber angle presented in the thickness direction of the beam continuously. Equilibrium Equations derived from first- order shear deformation theory and Hamilton principle. Simply supported boundary condition is considered for both edges of the beam.Eneralized differential quadrature method usedto solve the system of coupled differential Equations. To study accuracy of the present analysis, a compression carried out with a known data. The results shows that different parameters such as thickness to radius ratio, effect of temperature variations, model of fibers angle variations and power-law index affected on the natural frequencies

Measurement the effects of temperature and fiber orientation on vibration of functionally graded beam

This paper concerned with analytical approach to study the thermal vibration of fiber orientation functionally graded (FOFG) beam, that fibers`oriented angles are variable and graded in the thickness direction of the beam. Uniform thermal distribution considered in the entire beam and properties of fiber orientation functionally graded (FOFG) beam considered as the temperature-dependent element. Symmetrical, asymmetrical, and classical distribution types for the mode of fiber angle presented in the thickness direction of the beam continuously. Equilibrium Equations derived from first- order shear deformation theory and Hamilton principle. Simply supported boundary condition is considered for both edges of the beam.Eneralized differential quadrature method usedto solve the system of coupled differential Equations. To study accuracy of the present analysis, a compression carried out with a known data. The results shows that different parameters such as thickness to radius ratio, effect of temperature variations, model of fibers angle variations and power-law index affected on the natural frequencies

Rhegmatogenous retinal detachment: an analysis of 2315 eyes over a six-year period

Background: Rhegmatogenous retinal detachment (RRD) is a form of retinal detachment caused by passage of fluid from the vitreous cavity into the space between the neurosensory retina and the retinal pigment epithelium via a retinal break or full-thickness defect. At our tertiary referral center, we evaluated the clinical and epidemiological features of RRD, and we herein report the frequency of related risk factors. Methods: In this retrospective study, we reviewed the records of patients with a final diagnosis of RRD at an academic ophthalmological referral center in Isfahan, Iran, over a six-year period. We retrieved and reviewed data from the medical records of all eligible participants, including sex, age, laterality, lens status, macular status, type of RRD, location and number of breaks, type of surgery, rate of re-operation during the first year after initial surgery, and documented clinical risk factors for RRD. Clinical risk factors were categorized as the presence of myopic refractive error, ocular trauma, history of cataract surgery, history of other ocular surgeries, history of uveitis, or undetermined. Results: We included 2315 eyes of 2229 patients with a mean (standard deviation [SD]) age of 51.1 (16.9) years and a male-to-female ratio of 1.8:1. The most common quadrants containing retinal breaks were the superotemporal quadrant (34.1%), inferotemporal quadrant (23.4%), and superonasal quadrant (10.7%). Macula-involved RRD was seen in 90% of eyes (n=2083 eyes). The most frequently identified risk factors were cataract surgery (32.9%) and myopia (22.3%) in adults, and myopia (35.0%) and ocular trauma (27.4%) in the pediatric group. Most eyes underwent pars plana vitrectomy (51.3%), whereas pneumatic retinopexy (0.7%) was the least commonly selected. Conclusions: Our results indicate that cataract surgery and myopia are the most common risk factors for RRD in adults. Myopia and ocular trauma are the most common risk factors in pediatric patients. As observed in many studies, the characteristics of the study population, including middle age, male sex, myopia, and ocular trauma, may be associated with RRD at different rates. Further population-based longitudinal studies with larger sample sizes are required to verify these preliminary observations

Novel AM60-SiO2 Nanocomposite Produced via Ultrasound-Assisted Casting; Production and Characterization

There has been growing interest in developing new materials with higher strength-to-weight ratios. Therefore, AM60 magnesium alloy reinforced with SiO2 nanoparticles was synthesized using ultrasound-casting method for the first time, in this study. We introduced 1 and 2 wt.% of SiO2 nanoparticles into the samples. Introduction of nanoparticles led to the grain size drop in MS2 (AM60 + 2 wt.% SiO2) samples. In addition, this increased the hardness of samples from 34.8 Vickers hardness (HV) in M (AM60) to 51.5 HV in MS2, and increased the compressive strength of MS2. Improvement of the mechanical properties can be attributed to a combination of Orowan, Hall-Petch and load-bearing mechanisms. However, ductility of the composites decreased with fracture strains being 0.41, 0.39 and 0.37, respectively, for samples M, MS1 and MS2. Fracture surfaces showed shear fracture in both composite samples with microcracks and a more brittle fracture in MS2

Feed Forward Artificial Neural Network Model to Estimate the TPH Removal Efficiency in Soil Washing Process

Background & Aims of the Study: A feed forward artificial neural network (FFANN) was developed to predict the efficiency of total petroleum hydrocarbon (TPH) removal from a contaminated soil, using soil washing process with Tween 80. The main objective of this study was to assess the performance of developed FFANN model for the estimation of   TPH removal. Materials and Methods: Several independent repressors including pH, shaking speed, surfactant concentration and contact time were used to describe the removal of TPH as a dependent variable in a FFANN model. 85% of data set observations were used for training the model and remaining 15% were used for model testing, approximately. The performance of the model was compared with linear regression and assessed, using Root of Mean Square Error (RMSE) as goodness-of-fit measure Results: For the prediction of TPH removal efficiency, a FANN model with a three-hidden-layer structure of 4-3-1 and a learning rate of 0.01 showed the best predictive results. The RMSE and R2 for the training and testing steps of the model were obtained to be 2.596, 0.966, 10.70 and 0.78, respectively. Conclusion: For about 80% of the TPH removal efficiency can be described by the assessed regressors the developed model. Thus, focusing on the optimization of soil washing process regarding to shaking speed, contact time, surfactant concentration and pH can improve the TPH removal performance from polluted soils. The results of this study could be the basis for the application of FANN for the assessment of soil washing process and the control of petroleum hydrocarbon emission into the environments