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 work, we consider each normal alkane as a hypothetical mixtureof methyland methylene groups, in which the interaction potential of each pair is assumed to be the average effective pair potential. then, the lir equation of state (eos) is extended for such a hypothetical mixture. also, three basic compounds, namely, propane, n-butane and cyclohexane, are used to obtain the contribution of...

drought indices are commonly used to quantify and assess drought characteristics. the standardized precipitation index (spi), and recently introduced standardized precipitation-evapotranspiration index (spei) are considered as universal meteorological drought indices which allow comparisons of drought conditions across different climate regions. the spi captures anomalies in precipitation, wher...

volume estimation of most agricultural products using mathematical methods is not accurate because of their irregular shape. an alternative method is image processing, which can be used in continuous sorting machines. the objective of this study is to find a practical method for volume estimation of potatoes using image processing. fifty potatoes (marfona variety) were selected as experimental ...

abstract one of the losses decrease's ways in fields, is the proper irrigation management, which its base is the accurate estimation of crop water requirement. equations which are used to calculate the reference evapotranspiration (eto), do not use the same climatic parameters and due to their empirical base, are not match to all climatic situations. so it is needed to clarify proper methods fo...

background when a primary radiation interacts with a medium, the secondary radiations are produced, that the contribution of these secondary radiation should considered in the calculation of dose. build-up factor is a dosimetric correction factor to assume effect of secondary radiation in calculation of dose. calculation of this factor is very difficult and time consuming. due to significance o...