Background: Marine pollution is a global environmental problem that its monitoring by ideal biomonitors is of great importance. Marine organisms, especially mussels, have the ability to accumulate metals from the environment they can be considered as a biomonitoring agent. Methods: In this study, concentrations of heavy metals were measured in Saccostrea cucullata collected from seven sites on...

A parametric study was carried out in order to investigate the buckling capacity of the vertically stiffened cylindrical shells. To this end ANSYS software was used. Cylindrical steel shells with different yield stresses, diameter-to-thickness ratios (D/t) and number of stiffeners were modeled and their buckling capacities were calculated by displacement control nonlinear static analysis.  Radi...

This research was conducted to evaluate the possibility using peanut shells compost as a suitable medium in cultivating ornamental plants. Effect of peanut shells composts on the growth of Viola tricolor and marigold was investigated during seven months. Peat + perlite (with a ratio of 2:1) used as control treatment and peat replaced by 25, 50, 75 and 100 % v/v of peanut shells compost. Plant g...

This study aimed to investigate the effects of stiffeners on buckling of thin cylindrical shells under uniform axial compression. To this end, more than 300 finite element models of stiffened cylindrical shells were prepared. The variables considered are shell thickness, number, dimension and the location of the vertical and horizontal stiffeners as well as circular symmetrical imperfections. R...

Time-dependent creep analysis is presented for the calculation of stresses and displacements of axisymmetric thick-walled cylindrical pressure vessels made of functionally graded material (FGM). For the purpose of time-dependent stress analysis in an FGM pressure vessel, material creep behavior and the solutions of the stresses at a time equal to zero (i.e. the initial stress state) are needed....

In various fields of engineering, such structural elements are widely used that, from the point view their strength calculation, can be referred to thin shells (tanks, reservoirs, cylinders, etc.). When calculating thin-walled shells, a number hypotheses adopted simplify solution problem. The problem is most simply solved within framework momentless theory according which only force normal sect...

Abstract The NMR relaxivities of the decatungstolanthanoate core‐shell nanoparticles, prepared by encapsulating [Ln(W 5 O 18 ) 2 ] 9− polyoxometalates (LnPOM) within amorphous silica shells (K 9 ]@SiO ), were studied along Ln series. relaxivity GdPOM is slightly higher than for Gd‐DTPA due to second‐sphere relaxation effects, but values other paramagnetic LnPOMs are much smaller short T 1e thei...

http://dx.doi.org/10.1016/j.anbehav.2014.10.004 0003-3472/© 2014 The Association for the Study of A In resource defence polygyny, where males defend resources that females use for reproduction, the resource characteristics preferred by the two sexes are expected to match. We tested this expectation by comparing the shell characteristics preferred by males and females in the shell-brooding cichl...