in this research, softening and ratcheting behaviors of ck20 alloy steel cylindrical shells were studied under displacement-control and force-control cyclic axial loading and the behavior of hysteresis curves of specimens was also investigated. experimental tests were performed by a servo-hydraulic instron 8802 machine. the mechanical properties of specimens were determined according to astm e8...

background: recently, some new nanobiosensors using different nanoparticles or microarray systems for detection of mycotoxins have been designed . however, rapid, sensitive and early detection of aflatoxicosis would be very helpful to distinguish high-risk persons.objectives: we report a highly sensitive competitive immunoassay using magnetic/silica core shell as a signal intensifier for the de...

in this study, a specific ch4 sensor is fabricated based on interdigitated electrode that modified with core-shell of tungsten carbide/tin oxide (wc/sno2) nanoparticles by wet chemical method in different percents of carbon and tungsten. the morphology of wet chemical-synthesized wc/sno2 core-shell was evaluated by different methods such as patterned x-ray diffraction (xrd), and particle size a...

the natural frequencies and mode shapes of pneumatic tires are predicted using a geometrically accurate, three-dimensional finite element modeling. tire rubber materials and cord layers are represented independently using “shell element” available in cosmos. the effects of some physical parameters such as the inflation pressure tread pattern, thickness of belts and ply angles to the natural fre...

Shell of the adult hermit crab has some important roles for its fitness. In the same time, the shell size often limits the body growth of its owner. To grow the body size larger, the individual must change the shell to another larger shell. If the individual cannot get another larger one, the individual has to suppress the body size growth as the occupied shell size allows. Growth suppression w...

We presented in Ko et al. (2016) an MITC4+ shell element that shows a much improved convergence behavior when compared to the widely used MITC4 (Dvorkin and Bathe, 1984) shell element. However, the element does still not show optimal convergence behavior when used in distorted meshes in the analysis of some shell problems. In the present paper, we establish a new MITC4+ shell element which show...

The objective of this paper is to gain insight into finite element discretizations of shells using the basic shell mathematical model and, in particular, regarding the sources of ‘‘locking’’. We briefly review the ‘‘basic shell mathematical model’’ and present a formulation of shell finite elements based on this model. These shell finite elements are equivalent to the widely-used continuum mech...

This study examined localization of positive versus negative motivational functions mediated by GABA circuits within the accumbens shell. Microinjections of a GABA(A) agonist (0, 25, 75, and 225 ng/0.5 microl muscimol) in rostral shell sites elicited appetitive increases in eating behavior. In contrast, microinjections in caudal shell sites elicited defensive burying or paw-treading behavior. R...

to investigate the genetic diversity of persian walnut (juglans regia), 608 different walnut genotypes of neyriz region were evaluated for 30 morphological characteristics including kernel color, fruit shape, shell seal, shell texture and kernel plumpness, kernel weight, percentage of kernel as well as thickness of shell. the correlation between was traits in most cases significant at either 1 ...

in this study, the free vibration of partially fluid-filled laminated composite circular cylindrical shell with arbitrary boundary conditions has been investigated by using rayleigh-ritz method. the analysis has been carried out with strain-displacement relations based on love’s thin shell theory and the contained fluid is assumed irrotational, incompressible and inviscid. after determining the...