The microstructure and interfacial transition zone characteristics of Portland cement mortars prepared with a polynaphthalene sulfate (PNS) superplasticizer at relatively high dosages (0.8%, 1.5% by mass of cement) and varying sand-to-cement ratios (0.5, 1.0, 1.5) were investigated, using AC impedance spectroscopy, mercury intrusion porosimetry, helium pycnometry and two electrical conductance ...

Understanding the electrical properties of semiconducting quantum dot devices have been limited due to the variability of their size/composition and the chemistry of ligand/electrode binding. Furthermore, to probe their electrical conduction properties and its dependence on ligand/electrode binding, measurements must be carried out at the single dot/cluster level. Herein we report scanning tunn...

This paper reports on the influence of laser irradiation onto the electrical conductance of gold nanocontacts established with the mechanically controllable breakjunction technique. We concentrate here on the study of reversible conductance changes which can be as high as 200%. We investigate the dependence on the initial conductance of the contacts, the wavelength, the intensity and position o...

Transport in an ideal two-dimensional quantum spin Hall device is dominated by the counterpropagating edge states of electrons with opposite spins, giving the universal value of the conductance, 2e(2)/h. We study the effect on the conductance of a magnetic impurity, which can backscatter an electron from one edge state to the other. In the case of isotropic Kondo exchange we find that the corre...

This Letter reports on the influence of laser irradiation onto the electrical conductance of gold nanocontacts established with the mechanically controllable break-junction technique. We concentrate on the study of reversible conductance changes which can be as high as 200%. We investigate the dependence on the initial conductance of the contacts, and on the wavelength, the intensity, and the p...

The conductance of electrical synapses is usually estimated from voltage recordings at the neuronal somata under the assumption that each cell is isopotential. This approach neglects effects of intervening neurites. For a cell pair with unbranched neurites and an electrical synapse at their ends, we used cable theory to derive an analytical expression that relates the synaptic conductance to vo...

The conductance of electrical synapses is usually estimated from voltage recordings at the neuronal somata under the assumption that each cell is isopotential. This approach neglects effects of intervening neurites. For a cell pair with unbranched neurites and an electrical synapse at their ends, we used cable theory to derive an analytical expression that relates the synaptic conductance to vo...

A method is developed for placing bounds on the electrical contact conductance between contacting elastic bodies with rough surfaces. An analogy is ­ rst established between contact conductance and the incremental sti¬ness in the mechanical contact problem. Results from contact mechanics and the reciprocal theorem are then used to bracket the mechanical load{displacement curve between those for...

We investigate classical anomalous electrical transport in a driven, resistively, and capacitively shunted Josephson junction device. Intriguing transport phenomena are identified in chaotic regimes when the junction is subjected to both a time-periodic ac and a constant biasing dc current. The dependence of the voltage across the junction on the dc exhibits a rich diversity of anomalous transp...

We study the electrical conductance of gold nanoconstrictions by controlling the electrochemical potential. At positive potentials, the conductance is quantized near integer multiples of G0(2e(2)/h) as shown by well-defined peaks in the conductance histogram. Below a certain potential, however, additional peaks near 0.5G(0) and 1. 5G(0) appear in the histogram. The fractional conductance steps ...