Visualization of flapping wing of the drone beetle

Investigation of flapping wings of insect are focused on low Reynolds number effect and the unsteady aerodynamic properties. Interaction between flapping wing of insects and the air flow became one of important and fundamental research topics in micro air vehicle. The present work is aim to investigate the flow behavior of flapping wings of tethered scarab beetle. The generation mechanisms of velocity field and vortex formation are visualized with smoke-wire method. Tethered flight of the drone beetle shows the motion with elastic deformation of flapping wing. Measured flapping frequency is about 71 Hz and its frequency is higher than for dragonfly and butterfly. Beetle decreases negative lift by feathering motion in the upstroke process and increase positive lift by effect of wake capture in the downstroke process.     

Optimized perturbation theory in quantum electrodynamics

The optimized perturbation expansions, Grunberg's fastest apparent convergence and Stevenson's principle of minimal sensitivity, are applied to some low-energy QED quantities. The optimization does not disturb the experimentally established values, and, at higher orders, its effects are in the direction of reducing small differences between theoretical and experimental values.     

Corrections to νe−νμ universality in neutral current interactions

We examine the effects of higher-order corrections on the universality between ν_μ and ν_e in the Weinberg-Salam model. The leading correction to neutral current amplitudes is an apparent difference in the values of sin²θ as measured by ν_μ and ν_e beams. The difference is .     

High field magnetization of europium-graphite intercalation compound C6Eu

The whole magnetization curve of the first stage compound C₆Eu has been measured by using pulsed fields up to 400 kG below 40 K. For H ⊥ c, c being the crystal c-axis, four regions are observed in the magnetization curve; I) the initial magnetization region with an apparent moment of ～ 0.6micro_B per Eu ion (H < 12 kG), II) the intermediate region with nearly constant moment of 2.2 – 2.7 micro_B, which corresponds to $\text{1}\text{3}$ the full moment of Eu²⁺ ion (22 < H < 82 kG), III) the region of a linear field dependence (82 < H < 205 kG), and IV) the saturation region above 205 kG, where the saturation moment is found as 6.2 micro_B. For H//c, the magnetization increases monotonically and approaches to a saturation value corresponding to 6 micro_B above 240 kG.     

Two-dimensional diffraction study of ice crystallisation in polymer gels

Ice crystallisation in crosslinked dextran (Sephadex) gels was studied by the method of two-dimensional X-ray diffraction (XRD) in combination with the simultaneous measurement of differential scanning calorimetry (DSC). With a Sephadex G25 gel where an exotherm due to ice crystallisation is observed in the DSC rewarming trace, it was indicated by the XRD pattern that small ice crystals less than approximately 10 microns in diameter are readily formed during freezing, and that the endothermic trend prior to the exotherm is not due to the glass transition but due to the melting of the small ice crystals. Moreover, the diffraction pattern observed with frozen Sephadex gels depended on the density of crosslink indicating that ice crystals of different size and dimension are formed in the gels.     

Observation of a liquid-gas-type transition in the pyrochlore spin ice compound Dy2Ti2O7 in a magnetic field

Low temperature magnetization measurements on the pyrochlore spin ice compound Dy2Ti2O7 reveal that the ice-rule breaking spin flip, appearing at H approximately 0.9 T applied parallel to the [111] direction, turns into a novel first-order transition for T<0.36 K which is most probably of a liquid-gas type. T-linear variation of the critical field observed down to 0.03 K suggests the unusual situation that the entropy release across the transition remains finite [approximately 0.5 (J/K) x mol-Dy] as T-->0, in accordance with a breaking of the macroscopic degeneracy in the intermediate "kagomé ice" state.     

Regio-controlled ring-opening polymerization of perfluoroalkyl-substituted epoxides

Highly fluorinated epoxides were polymerized under mild conditions regioregularly, which gave easy access to isotactic polymers by using optically pure epoxides.     

On the functional properties of the confluent hypergeometric zeta-function

A zeta-function associated with Kummer’s confluent hypergeometric function is introduced as a classical Dirichlet series. An integral representation, a transformation formula, and relation formulas between contiguous functions and one generalization of Ramanujan’s formula are given. The inverse Laplace transform of confluent hypergeometric functions is essentially used to derive the integral representation.     

Influence of nonionic emulsifier included inside carboxylated polymer particles on the formation of multihollow structure by the alkali/cooling method

The influence of nonionic emulsifier, included inside styrene-methacrylic acid copolymer [P(S-MAA)] particles during emulsion copolymerization, on the formation of multihollow structure inside the particles via the alkali/cooling method (proposed by the authors) was examined in comparison to emulsifier-free particles. It was clarified that the nonionic emulsifier included inside the P(S-MAA) particles eased the formation of multihollow structure.Part CCL of the series studies on suspension and emulsion