The dynamics of the classical two-body Coulomb problem in a uniform magnetic field are explored numerically in order to determine when chaos can occur. The analysis is restricted to the configuration of planar particles with an orthogonal magnetic field, for which there is a four-dimensional phase space. Parameters of mass and charge are chosen to represent physically motivated systems. To chec...

Vortex-antivortex pairs are spontaneously created in magnetic elements. In the case of opposite vortex polarities the pair has a nonzero topological charge, and it behaves as a rotating vortex dipole. We find theoretically and confirm numerically its energy as a function of angular momentum and the associated rotation frequencies. The annihilation process of the pair changes the topological cha...

The behavior of rings of four small-capacitance tunnel junctions that are charged with two extra electrons is examined. Single electron charging effects result in quantization of charge on the metal electrode islands. To minimize the total electrostatic energy, the electrons localize on opposite electrodes, leading to a charge alignment in one of two configurations. We consider such rings as ce...

The lifetimes of B + and B 0 mesons have been measured using a sample of 400,000 hadronic Z 0 decays collected by the SLD experiment at the SLC between 1993 and 1998. This inclusive topological measurement includes 250,000 hadronic Z 0 decays collected since 1996 with the SLD upgrade vertex detector. A high statistics sample of 30028 19636 charged neutral vertices with good charge purity is obt...

In a nanographene ring with zigzag edges, the spin-polarized state and the charge-polarized state are stabilized by the on-site and the nearest neighbor Coulomb repulsions, U and V , respectively, within the extended Hubbard model under the mean field approximation. In a Möbius strip of the nanographene with a zigzag edge, U stabilizes two magnetic states, the domain wall state and the helical ...

Singlet-triplet spin blockade in a few-electron lateral double quantum dot is investigated using simultaneous transport and charge-sensing measurements. Transport from the 1,1 to the 0,2 electron occupancy states is strongly suppressed relative to the opposite bias 0,2 – 1,1 . At large bias, spin blockade ceases as the 0,2 triplet state enters the transport window, giving a direct measure of ex...

Electrospinning has been recognized as an efficient technique for the fabrication of polymernanofibers. Recently, various polymers have successfully been electrospun into ultrafine fibers.Electrospinning is an extremely promising method for the preparation of tissue engineering scaffolds.In this study, nanofibers gelatin was electrospun at 20% v/v optimized content. To produce...

Effect of nonsolvent in the polymer (polyvinyl butyral) solution in ethanol on the electrospinning performance and nanofiber properties was investigated. Water as the nonsolvent was added in various amounts to the polymer solution. Addition of water did influence neither surface tension nor conductivity of polymer solution significantly. On the other hand, it increased its viscosity. The perfor...

ZnO nanowires were produced using an electrospinning method and used in gas sensors for the detection of ethanol at 220 °C. This electrospinning technique allows the direct placement of ZnO nanowires during their synthesis to bridge the sensor electrodes. An excellent sensitivity of nearly 90% was obtained at a low ethanol concentration of 10 ppm, and the rest obtained at higher ethanol concent...