in this paper, penetration of high velocity impact of 4340 steel and tungsten carbide projectiles with specific shapes in to ceramic armor that includes 10 mm alumina (95%) is considered analytically and simulated with ls-dyna software. bernoulli equation used to consider the penetration velocity in ceramics, shows that the penetration is better and easier by increasing projectile density. the ...

in this study, the longitudinal shrinkage behavior of knitted fabrics during drying has been studied. in this context, a model is presented to predict the longitudinal shrinkage of plain knitted fabric during drying process. in order to model the shrinkage behavior, a 1dof model consists of a mass, a linear spring and a linear damper have been used. in presented model the time-varying mass is c...

This paper proposes a novel image denoising technique based on the normal inverse Gaussian (NIG) density model using an extended non-negative sparse coding (NNSC) algorithm. Here, we demonstrate that the NIG density provides a very good fitness to the non-negative sparse data. In denoising process, by exploiting a NIG-based maximum a posteriori estimator (MAP) of an image corrupted by additive ...

PURPOSE The purpose of this study was to compare the linear sintering behavior of presintered zirconia blocks of various densities. The mechanical properties of the resulting sintered zirconia blocks were then analyzed. MATERIALS AND METHODS Three experimental groups of dental zirconia blocks, with a different presintering density each, were designed in the present study. Kavo Everest® ZS bla...

In the current work, the properties of cement pastes doped with high amounts of ground granulated blast-furnace slag (HVS) were investigated. Portland cement (PC) was substituted with ground granulated blast-furnace slag (donated as slag) at very high amounts of 85%, 90%, 95% and 100%, by weight. PC paste without any content of slag was used as a reference. Some fresh and hardened properties su...

Changes in the tailing properties (increasing clay mineral content and fine particles) and poor operation of the dewatering systems have negative impacts on the Tailing Storage Facilities (TSF) of the Shahrbabak copper complex. The design solid concentration of the thickened tailings is 63 wt.% in the Shahrbabak paste plant but it is well below the design value right now (approx. 55 wt.%). The ...

Stein showed that the multivariate sample mean is outperformed by “shrinking” to a constant target vector. Ledoit and Wolf extended this approach to the sample covariance matrix and proposed a multiple of the identity as shrinkage target. In a general framework, independent of a specific estimator, we extend the shrinkage concept by allowing simultaneous shrinkage to a set of targets. Applicati...