Watt’s bath and pulse reverse (PR) electrodeposition is used to produce spherical nickelmultiwall carbon nanotubes (Ni-MWCNT) of 2.00, 0.93, 1.63 and 6.71 μm diameter and a variety ofsize distributions. For 60 cycles, an absolute electrodeposition current of 18 A/dm2 is applied atcurrent ratios of ii = idissolution/ideposition = 0, 0.077, 0.200 and 0.368. A simple exponential equation isfitted ...

The effect of multiple shallow corrosion pits on the strength a spherical vessel subjected to internal pressure is studied. are considered both randomly and evenly distributed along equator outer surface vessel. dependencies stress concentration factor number compared for linearly elastic elastic-plastic material with hardening. behavior vessels made elastoplastic materials turned out be qualit...

The objective of the research is to study and compare response surface designs: Central composite designs (CCD), BoxBehnken designs (BBD), Small composite designs (SCD), Hybrid designs, and Uniform shell designs (USD) over sets of reduced models when the design is in a spherical region for 3 and 4 design variables. The two optimality criteria ( D and G ) are considered which larger values imply...

Shielding radiation from both x-rays and gamma-rays is important for personnel in medical fields e.g. interventional radiology, nuclear power stations, and other inspection facilities where radiation is involved. Lead is known for its effective shielding property against these high energy radiations, however heaviness and toxicity are its main drawback. In this study effectiveness of non-lead p...

Spherical shell structures are the most suitable shape for deep-sea pressure hulls because they have ideal mechanical properties handling symmetrical pressure. However, accuracy requirement a hull in spherical structure subjected to is extremely high. Even minor asymmetry can significantly degrade its properties. In this study, new type of and integral hydro-bulge-forming (IHBF) method proposed...

One main feature of metamaterials is the occurrence of a negative dynamic mass density that is produced when an inner local resonance is present. The inner resonance can be obtained in composite materials containing composite inclusions. For suitable ratios of the physical properties of the constituting materials, the composite inclusions act as spring-mass systems. The scaling of physical prop...

An analytical investigation for the creeping motion of a spherically symmetric fluid-permeable composite sphere composed by a uniform porous core and a uniformly surrounded porous shell located at the center of a spherical cavity filled with an incompressible Newtonian fluid is presented here. In the limit of small Reynolds number, the Stokes and Brinkman equations are solved for the flow field...

Macroscopic constitutive relations based on the mean-field theory and the Mori–Tanaka method are derived for a 3-phase composite consisting of a polymer matrix and shape memory alloy (SMA) and piezoceramic (PZT) inclusions. Effective moduli are computed for likewise oriented spherical and cylindrical inclusions. Results are also computed for cylindrical PZT and ellipsoidal SMA inclusions. Even ...