Nuclear moments of neutron-rich aluminum isotopes

Ground-state magnetic-dipole moments (μ) of ^30-32Al and electric quadrupole moments (Q) of ^31,32Al have been measured with the β-NMR method using spin-polarized radioactive-isotope beams produced in projectile-fragmentation reactions. Beams of ^30-32Al were obtained by using RIKEN projectile-fragment separator RIPS after the fragmentation of ⁴⁰Ar projectiles at an energy of E = 95A MeV on a ⁹³Nb target. The obtained μ_exp[^30-32Al] and values agree well with shell-model calculations within the sd shell using the USD interaction. Also, Q_exp[³¹Al] was found to be small. Thus, we can conclude that these aluminum isotopes are located outside the island of inversion.     

Green-pumped high-power optical parametric oscillator based on periodically poled MgO-doped stoichiometric LiTaO3

A high-power 532 nm-pumped multikilohertz nanosecond optical parametric oscillator using a periodically poled 1.0 mol.% MgO-doped stoichiometric lithium tantalate crystal that could be operated from room temperature to 200 degrees C without damage is reported. A broad continuous tuning range from 855 to 1410 nm was achieved within a single domain period. Efficient operation of high peak power and watt level average power with a power conversion of 62.5% was measured. These results show that a high-resolution high average power visible tunable source can be realized.     

Investigation of non-acoustical parameters of compressed melamine foam materials

A series of careful non-acoustical parameters measurements using 5 ‘Illtec’ melamine foam and 10 ‘Basotect TG’ melamine foam samples have been made. Flow resistivity, tortuosity, porosity, viscous characteristic length and thermal characteristic length of two types of compressed melamine foam materials with different foam magnifications have been investigated. It has been found that a relationship between the flow resistivity, fibre equivalent diameter and bulk density exists for each of the compressed melamine foam materials.This paper also discusses relationships between the non-acoustical parameters and compression rates in the compressed melamine foam media.     

Global aspects of turbulence induced by heteroclinic cycles in competitive diffusion Lotka-Volterra equation

This paper presents detailed numerical results of the competitive diffusion Lotka-Volterra equation (May-Leonard type). First, we derive the global phase diagrams of attractors in the parameter space including the system size, where transition lines between simple attractors are clearly obtained in accordance with the results of linear stability analysis, but the transition borders become complex when multi-basin structures appear. The complex aspects of the transition borders are studied in the case when the system size decreases. Next, we show the statistical aspects of the turbulence with special attention to the onset of the supercritical Hopf bifurcation. Several characteristic quantities, such as correlation length, correlation time, Lyapunov spectra and Lyapunov dimension, are investigated in detail near the onset of turbulence. Our data show the critical scaling law near the onset only in the restricted parameter domain. However even when the critical indices are not determined accurately, it is shown that the empirical scaling relations are obtained in a wide parameter domain far from the onset point and those scaling indices satisfy several relations. These scaling relations are discussed in comparison with the result derived by the phase reduction method. Lastly, we make a conjecture about the stability of an ecosystem based on the bifurcation diagram: the ecosystem obeying the Lotka-Volterra equation in the case of May-Leonard type is stabilized more as the system size increases.     

Measurement of the magnetic field of resin-impregnated bulk superconductor annuli

Large single-grain bulk RE–Ba–Cu–O (RE: rare earth elements) superconductors can trap large fields exceeding several teslas and thus can function as very strong quasi-permanent magnets. We have found that the resin can penetrate into a bulk superconductor, when the sample was immersed in molten resin. Hence, resin impregnation was effective in improving mechanical properties. Three bulk superconductors‘ annuli with resin impregnation, each 50-mm i.d. and 80-mm o.d. was built and energized, by a field-cool method, to generate, in a bath of liquid nitrogen, a persistent trapped field of 1.62 T.     

Fe–Si core/Si-shell clusters prepared by double glow discharge sources

Journal of Nanoparticle Research - Using an improved plasma gas condensation cluster deposition system, Fe and Si clusters are prepared by a single glow discharge source and Fe/Si hybrid clusters...     

Quality control of PET radiopharmaceuticals by high‐performance liquid chromatography with tris(2,2′‐bipyridyl)ruthenium(II) electrogenerated chemiluminescence detection

A highly sensitive reversed‐phase liquid chromatographic (HPLC) method was investigated to analyze a range of positron emission tomography (PET) radiopharmaceuticals using electrogenerated chemiluminescence (ECL) detection. ECL is based on the reaction of PET molecules with tris(2,2′‐bipyridyl)ruthenium(III) [Ru(bpy)₃³⁺], which is generated through the on‐line electro‐oxidation of Ru(bpy)₃²⁺. In 21 different radiopharmaceuticals studied, 18 compounds could be detected with detection limits (signal‐to‐noise ratio = 3) of 0.12–72 ng/mL per 20 μL injection. Sufficient reproducibility and linearity were obtained for the quantitative determination of PET molecules in pharmaceutical fluid. This method could be successfully applied to quality control tests of PET radiopharmaceuticals with ultra‐high specific radioactivity. Copyright © 2009 John Wiley & Sons, Ltd.