Crystalline order and disorder in dusty plasmas investigated by nonequilibrium molecular dynamics simulations

The particle structure of a complex system has been explored through a unique Evans' s homogenous nonequilibrium molecular dynamics(HNEMD) simulation technique. The crystalline order–disorder structures(OD-structures) and the corresponding energies of three-dimensional(3 D) nonideal complex systems(NICSs) have been measured over a wide range of plasma states(■, κ) for a body-centered cubic(BCC) structure. The projected technique provides accurate ODstructures with fast convergence and applicable to very small size effect for different temperatures(≡ 1/■) and constant force field(F~*) values. The OD-structure obtained through HNEMD approach is found to be reasonable agreement and more reliable than those earlier identified by simulation approaches and experimental data of NICSs. New simulations of OD-structures show that dusty plasma remains in crystalline(strongly coupled) state at lower temperature and constant F*values, for the whole simulation runs. Our investigations show that the crystalline structure is changed and the particle structure switches from intermediate to disorder(nonideal gaseous) state with an increase of the system's temperature. It has been shown that the long range order shifts toward lower temperature with increasing κ. The presented technique exhibits that the potential energy has a maximum value when the dusty plasma remains in crystalline states(low temperatures),which confirms earlier 3 D simulation results.

Uniform and Homogeneous Growth of Copper Nanoparticles on Electrophoretically Deposited Carbon Nanotubes Electrode for Nonenzymatic Glucose Sensor

The multiwalled carbon nanotubes thin-film-based electrode was fabricated by electrophoretic deposition and modified with copper （Cu） nanoparticles to fabricate Cu/CNTs nanocomposite sensor for nonenzymatic glucose detection. The expensive glassy carbon electrode was replaced by fluorine-doped tin oxide glass containing CNTs film to confine the Cu nanoparticles growth by electrodeposition through cyclic voltammetry （CV）. The ultraviolet visible and X-ray diffraction analysis revealed the successful deposition of Cu nanoparticles on the CNTs-modified electrode. The atomic force microscopy images confirrqed the morphology of electrodeposited Cu on CNTs film as uniformly dispersed particles. The electrocatalytic activity of electrode to the glucose oxidation was investigated in alkaline medium by CV and amperometric measurements. The fabricated sensor exhibited a fast response time of less than 5 s and the sensitivity of 314 μA rnM^-1 cm^-2 with linear concentration range （0.02-3.0 mM） having detection limit 10.0 μM. Due to simple preparation of sensor, Cu/CNTs nanocomposite electrodes are a suitable candidate for reliable determination of glucose with good stability.

Antibacterial Behavior of Laser-Ablated Copper Nanoparticles

Copper nanoparticles（Cu NPs） have been synthesized by using laser ablation method,using deionized water as main solvent.The formation of Cu NPs is confirmed by UV-visible spectrophotometer（UV-Vis）,atomic force microscopy（AFM） and X-ray diffraction（XRD）.Cu NPs fabricated by laser ablation have diameter in the range from 14 to 55 nm.Structural analysis revealed the face-centered cubic（fcc） crystal structure of Cu NPs.The antibacterial activity of Cu NPs has been evaluated in vitro against strains of Escherichia coli（E.coli） and Staphylococcus aureus（5.aureus）.The fabricated Cu NPs show considerable antibacterial activity against both bacterial strains.The bacterial activity of Cu NPs was found to depend on the microbial species.