A method is developed for computing the direct current and alternating current conductance of molecular wires at small bias. The basic ingredients are: linear response theory, time-dependent density functional theory, imaginary potentials, and a jellium model for the metallic leads. The theory is capable of incorporating the effect of realistic charge distributions in the system and electron–el...

We discuss the conductance of a molecular bridge between mesoscopic electrodes supporting low-dimensional transport and bearing an internal structure. As an example for such nanoelectrodes we assume semi-infinite (carbon) nanotubes. In the Landauer scattering matrix approach, we show that the conductance of this hybrid is very sensitive to the geometry of the contact, unlike the usual behavior ...

Many phenomena in molecular transport junctions involve transitions between electronic states of the molecular wire, and, therefore, cannot be described adequately using the Landauer picture. We present a model for cotunneling processes in molecular wires. These are coherent second-order processes that can be observed at low temperatures. As an example, we consider the STM-induced dissociation ...

A conducting atomic force microscope was used to measure the electrical properties of carotenoid molecules attached to a gold electrode. The thiolated carotene molecules were embedded in insulating n-alkanethiol self-assembled monolayers. At a contact force of a few nanoNewtons, a carotenoid molecule behaves ohmically with a resistance of approximately 4.2 ( 0.7 GΩ, over a million times more co...

Stephanie A. Getty,1 Chaiwat Engtrakul,2,* Lixin Wang,2 Rui Liu,3 San-Huang Ke,3,4 Harold U. Baranger,4 Weitao Yang,3 Michael S. Fuhrer,1,† and Lawrence R. Sita2,‡ 1Department of Physics and Center for Superconductivity Research, University of Maryland, College Park, Maryland 20742, USA 2Department of Chemistry and Biochemistry, University of Maryland, College Park, Maryland 20742, USA 3Departm...

Human carbonic anhydrase II (HCA II), among the fastest enzymes known, catalyzes the reversible hydration of CO 2 to HCO 3 (-). The rate-limiting step of this reaction is believed to be the formation of an intramolecular water wire and transfer of a proton across the active site cavity from a zinc-bound solvent to a proton shuttling residue (His64). X-ray crystallographic studies have shown thi...

The wire drawing process is extensively used in manufacturing components such as rivet, screw, welding wire, etc. In this work, an analytical of the wire drawing process has been considered for two-stage operation. ABAQUS commercial Finite Element code has been used to obtained the drawing force. Then, The analytical and experimental results been compared. The results show a good agreement for...

  Objective: Corrosion resistance is among the most important properties of metal alloys used in the oral cavity. Consumption of acidic foods reduces the salivary pH and intensifies the corrosion of brackets and orthodontic wires. This study aimed to compare electro galvanic corrosion of different orthodontic brackets and wires and determine the amount of ions released into acidic artifici...

in this paper, scattering of a plane and monochromatic electromagnetic wave from a nano-wire is simulated using surface integral equations. first, integral equationsgoverning unknown fields on the surface is obtained based on stratton-cho surface integral equations. then, the interaction of the wave with a non-plasmonic as well as a palsmonic nano-wire is considered. it is shown that in scatter...

An ultrafine grain surface layer with average crystallite size of 28 nm was produced on annealed mild steel through a wire brushing process. The effects of grain size reduction on the inhibition performance of sodium phosphate were investigated using polarization and electrochemical impedance spectroscopy (EIS) measurements. The crystal grain size of wire brushed surface was analyzed by X-ray d...