Reliability and Reliability-based Sensitivity Analyses of Steel Moment-Resisting Frame Structure subjected to Extreme Actions

The ground external columns of buildings are vulnerable to the extreme actions such as a vehicle collision. This event is a common scenario of buildings' damages. In this study, a nonlinear model of 2-story steel moment-resisting frame (SMRF) is made in OpenSees software. This paper aims investigating the reliability analysis of aforementioned structure under heavy vehicle impact loadings by Monte Carlo Simulation (MCS) in MATLAB software. To reduce computational costs, meta-model techniques such as Kriging, Polynomial Response Surface Methodology (PRSM) and Artificial Neural Network (ANN) are applied and their efficiency is assessed. At first, the random variables are defined. Then, the sensitivity analyses are performed using MCS and Sobol's methods. Finally, the failure probabilities and reliability indices of studied frame are presented under impact loadings with various collision velocities at different performance levels and thus, the behavior of selected SMRF is compared by using fragility curves. The results showed that the random variables such as mass and velocity of vehicle and yield strength of used materials were the most effective parameters in the failure probability computation. Among the meta-models, Kriging can estimate the failure probability with the least error, sample number with minimum computer processing time, in comparison with MCS

Exploring accuracy of statistical characterization of gravel beds using Kinect device in the laboratory scale

Mountainous river beds-generally consist of gravel particles that the precise description of such bed is not only important hydraulically, but also it has great environmental significance. The accurate estimation of bed roughness gives us valuable information to make reliable hydraulic models of flow in river with rigorous bed form. This study discuses about the accuracy of the Kinect device in determining the digital elevation model (DEM) of the gravel-bed. In this regard, the DEMs of the two beds include-hemispheres and two beds with artificial gravel beds have been -used and their statistical characteristics have been analyzed. The results show that while the error in the area among the particles is quite high, themethod can accurately conduct these in general. The comparison of the bed elevation histograms shows that although the artificial gravel beds histograms have higher accuracy compared to the histograms of the beds with hemispheres form, the gravel bed with distance elevations histogram shows the best fit among the four explored beds. Furthermore, exploring the statistical characteristics of these four beds shows that the Kinect device is able to obtain reasonable error rate in statistical parameters except the skewness quantity which has the highest rate of relative error. The variogram analysis of artificial gravel beds emphasis that the Kinect and scanner variograms reasonably close to each other and the longitudinal and transversal particles length scales are exactlythe same. According to the results of this investigation, application ofthe Kinect device in statistical analysis of the gravel beds can be suggested

Corresponding Author Study of effects Aloe vera extract supplemented feed on hematological and immunological indices of rainbow trout (Oncorhynchus mykiss)

ABSTRACT The aim of this study was to evaluate the effects of Aloe vera extract (AE) on the immunity responses and hematological parameters in rainbow trout (Oncorhynchus mykiss) fry to develop alternative drug to chemotherapeutics and antibiotics in aquaculture. 1200 rainbow trout (Oncorynchus mykiss) fry weighing 2±0.2 gram were randomly allocated into two treatment groups including: 1) placebo-treated group (control), 2) Aloe vera extract-treated group, each of three replicates. The fishes were hand-fed once a day with diet medicated AE or placebo at a rate of 1% of feed weight in the first feeding for 8 weeks. At the end of every two weeks 24 hrs after feeding, some of hematological and immunological parameters were analyzed. The results showed that serum total protein, albumin and globulin, respiratory burst activity, phagocytic activity and serum lysozyme activity vary among the two treatment groups which were found to be higher in AE-treated group (p<0.05). However there were no significant differences in hematological parameters between two groups. It was concluded that supplementation of AE at a rate of 1% registered higher immunological responses in compared to placebo group. Therefore, supplementation of AE in fish diets would enhance the nonspecific immunity responses and would be use particularly at time of outbreaks