The electronic behavior of metallic carbon nanotubes under the influence of atomistic vacancy defects present in the channel is theoretically investigated using non-equilibrium Green’s function method self-consistently coupled with three-dimensional electrostatics. A nearest neighbor tight binding model based on a single pz orbital is used for the device Hamiltonian. A single vacancy defect in ...

A typical MCP consists of about 10,000,000 closely packed channels of common diameter which are formed by drawing, etching, or firing in hydrogen, a lead glass matrix. Typically, the diameter of each channel is ~ 10 microns. Each channel acts as an independent, continuous dinode photomultiplier. In astronomy, and in the many other fields that use MCPs, the detectors are generally used for disto...

The effect of catalyst particle size on dehydration of methanol to dimethyl ether is investigated using fixed bed and micro-channel reactors at different temperatures and weight hourly space velocities. The experiments were carried out at 290 and 320oC. The space velocities were changed from 10 up to 90h-1 and from 1.22 to 3.65h-1 for fixed bed and micro-channel reactors, respectively. Consider...

The influence of the sample size (diameter while keeping the length constant) in equal channel angular pressing (ECAP) of pure aluminum is examined using finite element method (FEM) and experiment. Different sized aluminum rods were processed via ECAP and the effect of sample size on the strain homogeneity, process load, and the ratio of the friction to the total force were evaluated. The resul...

Ion transport from one aqueous (W1) to another (W2) across bilayer lipid membranes (BLM) containing gramicidin A (GA) was investigated by recording current fluctuations, when various alkali metal chlorides and potassium salts were used as supporting electrolytes. The magnitude of the single-channel current at a given membrane potential depended on not only the cationic species, but also on the ...

Introduction: Intracellular pH (pHi) regulates essentially all aspects of cellular activities. However, it is unknown how endoplasmic reticulum (ER) potassium channels sense pHi. In this study, we investigate the direct effects of pHi on ER potassium channels. Methods: We used channel incorporation into the bilayer lipid membrane method. L-α-phosphatidylcholine, a membrane lipid, was extrac...

BACKGROUND Channel proteins like FhuA can be an alternative to artificial chemically synthesized nanopores. To reach such goals, channel proteins must be flexible enough to be modified in their geometry, i.e. length and diameter. As continuation of a previous study in which we addressed the lengthening of the channel, here we report the increasing of the channel diameter by genetic engineering....

Two-dimensional Poisson-Boltzmann and momentum equations are solved simultaneously to study the transient characteristics of electro-osmotic pumping in a rectangular microchannel. A finite difference scheme with variable grid spacing is used to calculate electric potential distribution. Time variations of velocity profiles are obtained by using a combined ADI-TDMA technique. Numerical solutions...