A series of pyridinium-based cationic surfactants has been synthesised and their amphiphilic properties have been studied by conductivity and surface tension measurements. The modification of the substitution pattern on the pyridinium ring by hydrophobic moieties (methyl vs. hydrogen and presence or not of condensed benzene ring) gave the opportunity to investigate structure-activity relationsh...

SKD 11 tool steel is among the most popular metals in mold industries for making different kinds of cold work molds and dies with high accuracy and long service life. The demand for higher quality, lower manufacturing costs, particularly the environmentally friendly characteristics, have provided the stimuli for manufacturers and researchers to find alternative solutions. An excellent media is ...

Post growth annealing of solution grown ZnO nanowire array is performed under controlled oxygen ambience. The role of annealing over surface defects and their consequence on dark/photo-conductivity and photosensitivity of nanowire array is investigated. Surface defect properties are explored using various measurement tools such as contact angle, photoluminescence, Raman spectroscopy and XPS mea...

The effect of surface bond-order loss on the electronic thermal conductivity of metallic polycrystalline films is examined using Boltzmann transport theory. A modification of the grain boundary potential barrier has been made by adding depressed potential wells of intra-atomic trapping C. Q. Sun, Phys. Rev. B 69, 045105 2004 to both sides of the grain boundaries. Electron scattering by film sur...

The optical properties of superconductors, in particular the real parts of the conductivity and the dielectric function, may be used to calculate the strength of the condensate. In systems where all the free carriers collapse into the condensate, this approach works well. However, in gapless systems, and in unconventional systems in which the superconducting energy gap is observed to have zeros...

The 5×5, 6√3×6√3-R30°, and graphene-covered 6√3×6√3-R30° reconstructions of the SiC(0001) surface are studied by scanning tunneling microscopy and spectroscopy. For the 5×5 structure a rich spectrum of surface states is obtained, with one state in particular found to be localized on top of structural protrusions (adatoms) observed on the surface. Similar spectra are observed on the bare 6√3×6√3...

In the past few years, different models and analytical approximations have been developed facing the problem of the electrical conductivity of a concentrated colloidal suspension, according to the cell-model concept. Most of them make use of the Kuwabara cell model to account for hydrodynamic particle-particle interactions, but they differ in the choice of electrostatic boundary conditions at t...

Silicon carbide nanofibers grew on the surface of carbon fibers of a unidirectional carbon preform by CCVD and then chemical vapor infiltration was used to densify the preform to get the SiCNF-C/C composite. The effects of silicon carbide nanofibers on the microstructure of the pyrolytic carbon and the thermal conductivity of the SiCNF-C/C composite were investigated. Results show that silicon ...

A temporary increase in the conductivity of aluminum oxide sputter deposited on the surface of aluminum wafers was made by exposure to vacuum ultraviolet ~VUV! radiation produced by a synchrotron light source. The oxide was charged, either positively or negatively, by exposure to a nonreactive inductively coupled plasma, under typical plasma processing conditions. We show the dependence of the ...