Reference material for radionuclides in sediment IAEA-384 (Fangataufa Lagoon sediment)

A reference material designed for the determination of anthropogenic and natural radionuclides in sediment, IAEA-384 (Fangataufa Lagoon sediment), is described and the results of certification are presented. The material has been certified for 8 radionuclides (⁴⁰K, ⁶⁰Co, ¹⁵⁵Eu, ²³⁰Th, ²³⁸U, ²³⁸Pu, ^239+240Pu and ²⁴¹Am). Information values are given for 12 radionuclides (⁹⁰Sr, ¹³⁷Cs, ²¹⁰Pb (²¹⁰Po), ²²⁶Ra, ²²⁸Ra, ²³²Th, ²³⁴U, ²³⁵U, ²³⁹Pu, ²⁴⁰Pu and ²⁴¹Pu). Less reported radionuclides include ²²⁸Th, ²³⁶U, ²³⁹Np and ²⁴²Pu. The reference material may be used for quality management of radioanalytical laboratories engaged in the analysis of radionuclides in the environment, as well as for the development and validation of analytical methods and for training purposes. The material is available from IAEA in 100 g units. Retired from IAEA in 2003.     

Fluid membranes exchanging material with external reservoirs

We investigate the dynamics of a single component fluid bilayer, which exchanges material with the surrounding fluid. We derive covariant equations of motion taking into account solvent permeation, exchange of lipids between solvent and the membrane and discuss the sources of noise in these equations. Different lipid concentrations on both sides of the membrane lead to a non-equilibrium state. We discuss steady states as well as shape instabilities which occur at a critical osmotic-pressure difference.Received: 30 March 2004, Published online: 31 August 2004PACS: 05.40.-a Fluctuation phenomena, random processes, noise, and Brownian motion - 87.16.Ac Theory and modelling; computer simulation - 87.16.Dg Membranes, bilayers, and vesicles     

Socioeconomic implications of donation distributions

Individual donation depends on personal wealth and individual willingness to donate. On the basis of a donation model proposed in our previous study, a simplified version of an individual donation model is derived by relaxing the restrictions of the maximum wealth in the economy. Thus, the whole distribution is determined by only two parameters. One of them relates to the exponent of the distribution of society wealth and the other refers to the donation amount of the kindest poorest person. The parameters reflect the degree of wealth inequality and the charitable enthusiasm of society, respectively. Using actual donation data, we develop a specific parameter estimation method combining linear regression and the Kolmogorov–Smirnov (KS) statistic to get the value of two socioeconomic indicators. Applications to Chinese individual donations in response to the 2004 Indian Ocean tsunami and the 2008 Wenchuan earthquake indicate a rising inequality in social wealth distribution in China. Also, more charitable enthusiasm is observed in the response to the 2008 Wenchuan earthquake.     

Noise reduction using three-step gain factor and iterative-directional-median filter

Musical residual noise is a major problem for a speech enhancement system. This noise is very annoying to the human ear and can significantly deteriorate the perception quality of enhanced speech. In this study, we aim at reducing the quantity of musical residual noise by a two-stage speech enhancement approach. In the first stage a preprocessor enhances noisy speech using an algorithm which combines the two-step-decision-directed and the Virag methods. In the second stage the enhanced speech signal is post-processed by an iterative-directional-median filter to significantly reduce the quantity of residual noise, while maintaining the harmonic spectra. Experimental results show that the proposed approach can significantly improve the performance of a speech enhancement system by reducing the quantity of residual noise.     

On the single-root approach within the framework of coupled-cluster theory in Fock space

A thorough formulation of Fock Space Brillouin–Wigner Coupled Cluster method is presented following previous developments [N.D.K. Petraco, Ľ. Horný, H.F. Schaefer, I. Hubač, J. Chem. Phys. 117 (2002) 9580]. The new method is designed to avoid the intruder states problem, and introduces the single-root solution feature which has not been considered yet within valence-universal methods. The explicit equations for the (0,1) sector of the Fock space are introduced.     

Uncertainties on the measurements of the top mass at a future e+e- collider

The uncertainties due to limited knowledge of the multi-hadron final state on the measurements of the top mass at future linear colliders are discussed. This study is performed for annihilation events at the center-of-mass energy of s ^1/2 =500 GeV using Monte Carlo models tuned to LEP experiments. The uncertainties are determined for the all-hadronic top-decay mode as well as for the lepton-plus-jets channel.     

Iron(III) chloride and its coordination chemistry

Abstract

The coordination chemistry of FeCl₃ is distinctly different to that of the other 3d metal halides. It has a distinct preference for O-donor ligands. Although it primarily forms six-coordinate complexes, it has some distinctive features that set it apart from metals like Mn(II), Co(II), and Ni(II), such as the self-ionized complexes [FeL₄Cl₂]⁺ [FeCl₄]^?. There are a number of examples where very small changes in the coordination sphere tilt the balance between isomeric structures. Chloride has a significant steric effect in the coordination sphere as well as a greater trans-influence than water.     

Determination of the number of J/ψ events with J/ψ → inclusive decays

The number of J/ψ events collected with the BES0 detector at the BEPC/ from June 12 to July 28, 2009 is determined to be (225:3±2:8)×10⁶ using J/ψ → inclusive events, where the uncertainty is the systematic error and the statistical one is negligible.     

Colour reconnection in e+e– → W+W–at {\sqrt s } =180–209 GeV

The effects of the final state interaction phenomenon known as colour reconnection are investigated at centre-of-mass energies in the range ≃ 189–209 using the OPAL detector at LEP. Colour reconnection is expected to affect observables based on charged particles in hadronic decays of . Measurements of inclusive charged particle multiplicities, and of their angular distribution with respect to the four jet axes of the events, are used to test models of colour reconnection. The data are found to exclude extreme scenarios of the Sj?strand-Khoze Type I () model and are compatible with other models, both with and without colour reconnection effects. In the context of the model, the best agreement with data is obtained for a reconnection probability of 37%. Assuming no colour reconnection, the charged particle multiplicity in hadronically decaying W bosons is measured to be =19.38±0.05(stat.)±0.08(syst.). Arrival of the final proofs: 28 November 2005