It is known that the directed cycle of order $n$ uniquely achieves the minimum spectral radius among all strongly connected digraphs of order $nge 3$. In this paper, among others, we determine the digraphs which achieve the second, the third and the fourth minimum spectral radii respectively among strongly connected digraphs of order $nge 4$.  

In this paper some upper and lower bounds for the greatest eigenvalues of the PI and vertex PI matrices of a graph G are obtained. Those graphs for which these bounds are best possible are characterized.

Potassium Channels allow potassium flux and are essential for the generation of electric current acrossexcitable membranes. Potassium Channels are also the targets of various intracellular controlmechanisms; such that the suboptimal regulation of channel function might be related to pathologicalconditions. Realistic studies of ion current in biologic channels present a major challenge for compu...

in this work we simulated the representative volume element (rve) of carbon nanotube (cnt) which is surrounded by high temperature superconductor (ybco) by using ansys finite element software. first we considered perfect model (for ybco and cnt) and investigated the effect of radius, length, and the number of nanotube in young’s modulus of the ybco by applying force on rve. then, a third region...

Abstract Estimation of the radius maximum wind (RMW) tropical cyclone (TC) is helpful for disaster prevention and mitigation. If RMWs are estimated from infrared (IR) imagery taken by geostationary meteorological satellites, their estimation available densely in time, regardless ocean basin. Kossin et al. showed that when TCs have clear eyes, eye radii IR images a high correlation with RMW airc...

introduction: this study investigated the fatigue and fracture modes of race and protaper rotary instruments. materials & methods: fatigue resistance was evaluated by rotating the files 30 ° or 60 ° and with 2 or 5mm radius of curvature. race taper 06 size 25 and protaper f1 files (n=40) were used. the number of rotations to failure was analyzed by two-way anova and independent sample     t-tes...