The synthesis and characterization of gas phase oxygen- and nitrogen-functionalized multi-walled carbon nanotubes (OMWCNTs and NMWCNTs) and the dispersibility of these tubes in organic solvents were investigated. Recently, carbon nanotubes have shown supreme capacity to effectively enhance the efficiency of organic solar cells (OSCs). A critical challenge is to individualize tubes from their bu...

Nowadays, functionally graded materials (FGM) are widely used in many industrial, aerospace and military fields. On the other hand, the interest in the use of shrink-fitted assemblies is increasing for designing composite tubes, high-pressure vessels, rectors and tanks. Although extensive researches exist on thick-walled cylindrical shells, not many researches have been done on shrink-fitted th...

Experiments were carried out in FY04 on detonation wave structure, detonation wave diffraction, and the fracture of thin-walled tubes by detonation waves. Computations were performed on detonation wave propagation and the elastic response of tubes to detonation loading. One new effort was initiated on the diffraction of detonation waves, and the other activities were a continuation of previous ...

The process of freezing of water and blockage of pipes are summarized. Current research on freezing and its applications are briefly reviewed. Design concepts are introduced for doing work by utilizing pressures caused by ice blockage. Several conceptual designs are presented for experimental setups for the isostatic pressurization of thin walled tubes. Potential practical uses of pressures gen...

A correlation is observed between the diameters (d) of single-walled carbon nanotubes and the percentages of metallic and semiconducting tubes synthesized at 600 degrees C by plasma-assisted chemical vapor deposition. Small tubes (d approximately 1.1 nm) show semiconductor percentages that are much higher than expected for a random chirality distribution. Density functional theory calculations ...

We model diffusion in white matter fascicles as a problem of diffusion in an array of identical thick-walled cylindrical tubes immersed in an outer medium and arranged periodically in a regular lattice. The diffusing molecules have different diffusion coefficients and concentrations (or densities) within the tubes' inner core, membrane, myelin sheath, and within the outer medium. For an imperme...

The crush behaviors of steel tubes filled with nanoporous-materials-functionalized liquids are experimentally investigated under quasi-static and dynamic conditions. Results show that the nanoporous-materials-functionalized liquid can enhance the load-carrying and the energy absorption capacities of thin-walled tubes, as the buckling mode is affected. The effective buckling stress increases wit...

The role of loading rate and fluid properties in the fracture of piping under internal explosions is an important issue for designers and accident analysis. This was examined by fracture experiments on thin-walled and preflawed aluminum 6061-T6 tubes. The tubes were 1) statically loaded with oil, 2) statically loaded with nitrogen, and 3) dynamically loaded with gaseous detonations traveling at...

Cylindrical thin-walled tubes due to construction and easy installation, high energy absorption capacity are used in the automotive industry as an impact energy absorber. However, the main weakness of cylindrical tubes is in the high initial peak load. Therefore, in this paper, to overcome this weakness, a buckling initiator is used at the top of the tube. This buckling initiator is a steel rod...

This study investigates the effects of nanostructure size and surface area on the rheological properties of un-cross-linked poly(propylene fumarate) (PPF) nanocomposites and the mechanical properties of cross-linked nanocomposites as a function of the nanostructure loading. Three model carbon nanostructures were examined, C(60) fullerenes, ultra-short single-walled carbon nanotubes (US-tubes) a...