A quantum-mechanical simulation is carried out to investigate the charge distribution and electrostatic potential along a 1 microm long (5,5) single-walled carbon nanotube under realistic field-emission experimental conditions. A single layer of carbon atoms is found sufficient to shield most of the electric field except at the tip where strong field penetration occurs. The penetration leads to...

Thermal reactions of Co(200 A) /Si0,76Ge0,24( 1500 A) /Si and Co(200 A) /Si0,54Ge0,46( 1000 A) /Si systems in a vacuum of l2 X 10m6 Torr were studied. At temperatures above 200°C Ge segregation appeared even though no silicides and/or germanosilicides were formed. At a temperature of 225-550°C Co(Si, -vGe,) was formed, in which the Ge concentration was deficient. The formation temperatures of C...

The aim of this study was to investigate the feasibility of using layer-by-layer polymer coated gold nanoparticles (AuNP) as a carrier for topical iontophoretic delivery of imatinib mesylate (IM). AuNP were prepared by the Turkevich method and were stabilized and functionalized using polyvinylpyrrolidone and polyethylene imine. The functionalized AuNP were then sequentially coated with anionic ...

PURPOSE Potential causes of drug resistance in solid tumors include genetically determined factors expressed in individual cells and those related to the solid tumor environment. Important among the latter is the requirement for drugs to penetrate into tumor tissue and to achieve a lethal concentration in all of the tumor cells. The present study was designed to characterize further the multice...

The theory of delayed fluorescence produced in an organic material by singlet excitation through an absorbing layer is given. It is shown, that it will be reduced by a factor la.2/ ( la .+ ls) 2 due to the singlet energy transfer to such a layer, where /a the penetration depth of the exciting irradiation and Zs the diffusion lenght of the singlets. Further reduction of delayed fluorescence shou...

Light scattering, or the so-called Yule-Nielsen effect, and ink penetration into the substrate paper play important roles in tone reproduction. We develop a framework in which the influences of both of these effects on the reflectance and tristimulus values of a halftone sample are investigated. The properties of the paper and the ink and their bilateral interaction can be parameterized by the ...

We present a new method to measure the triplet exciton diffusion length in organic semiconductors. N,N'-di-[(1-naphthyl)-N,N'-diphenyl]-1,1'-biphenyl)-4,4'-diamine (NPD) has been used as a model system. Triplet excitons are injected into a thin film of NPD by a phosphorescent thin film, which is optically excited and forms a sharp interface with the NPD layer. The penetration profile of the tri...

Bulk niobium Superconducting Radio-Frequency cavities are a leading accelerator technology. Their performance is limited by the cavity loss and maximum acceleration gradient, which are negatively affected by vortex penetration into the superconductor when the peak magnetic field at the cavity wall surface exceeds the vortex penetration field (Hvp). It has been proposed that coating the inner wa...