Physical characterization of uranium oxide pellets and powder applied in the Nuclear Forensics International Technical Working Group Collaborative Materials Exercise 4

Journal of Radioanalytical and Nuclear Chemistry - Physical characterization is one of the most broad and important categories of techniques to apply in a nuclear forensic examination. Physical...     

Measurement of force components for ink detachment of newsprints

Ink detachment tests were carried out using a Couette device. During the test, the energy supplied to the operation of the device partially dissipated as heat. The fraction of energy dissipated increased with pulp consistency. The fraction of energy for peeling and pulling the ink from the printed samples were calculated. At 4% consistency, the energy for pulling was much higher than for peeling, while at higher consistencies, the peeling effect became more significant. The ink detachment was highly dependant on how the pulp interacted with the printed surface. This interaction was influenced by pulp consistency and the energy applied to the rotor of the Couette device. Copyright © 2008 John Wiley & Sons, Ltd.     

Bio-organism detection in one-dimensional photonic crystals using electromagnetically induced transparency

We propose an optical sensor that allows site-selective detection of a refractive index change occurring due to any infiltration such as a bio-organism in a porous one-dimensional photonic crystal (PC). We use the electromagnetically induced transparency (EIT) to detect and locate the infiltration. With a localized change in the refractive index, the maximum of the peak EIT transmission shifts, which is determined by tuning the control field frequency. The strong dispersion and the narrowing of the absorption free response associated with EIT within the PC form the basis of such enhanced sensitivity.     

Determination of the quenching rates of N2+(B2Σu+, ν = 0,1) By N2 using laser-induced fluorescence

Time-resolved fluorescence laser-induced spectroscopy was used to examine the quenching of the vibrational levels ν = 0 and ν = 1 of N₂⁺(B²Σ_u⁺) by N₂. The rate coefficients of the quenching reactions are found to be constant over the temperature range 300–500 K. The quenching constant for the ν = 1 state was found to be approximately twice the value of the quenching constant of the ν = 0 state.     

The correlation of core replacement energies with nonbonding s electron density

Core replacement energies are calculated for nitrogen and oxygen in various gaseous cations from accurate core binding energies and thermodynamic data. The values for a given element differ in some cases by much more than the experimental errors. These chemical shifts in core replacement energy can be rationalized by recognizing that they are equal to the shifts in the energy of transfering an electron from a core level to a nucleus. As expected, relatively endothermic core replacement energies are found for atoms which have a high density of nonbonding valence s electrons.     

High critical currents for dendrite penetration and voiding in potassium metal anode solid-state batteries

Journal of Solid State Electrochemistry - Potassium metal anode solid-state cells with a K-beta”-alumina ceramic electrolyte are found to have relatively high critical currents for dendrite...     

Diversification and selection mechanisms for the production of protein repertoires: lessons from the immune system

The physiological mechanism for producing antigen-specific antibodies is based on a two-phase neo-Darwinian process: the first phase consists of diversity generation (formation of the repertoire), and the second phase is antigen-mediated selection. In this article, we consider how the natural immunoglobulin gene-diversification processes can be exploited both in vivo and in vitro in order to allow the generation of novel antibody (and heterologous protein) repertoires.     

Simulation microscopic chemical processes. IV. Temperature dependence of deactivation and dissociation of bromide in argon

Previous molecular dynamics simulations of the deactivation or dissociation of a bromine molecule at an energy just above the minimum required for dissociation and surrounded by an argon medium in canonical equilibrium has been extended from 1500 K to 160 and 295 K. The aim is to observe the extent to which temperature determines the qualitative as well as quantitative features of the process. Despite an observed sensitivity to the initial state of the medium which required introduction of a Monte Carlo selection procedure the final results indicate that the deactivation—dissociation mechanism is insensitive to temperature changes in the range presently explored. We conclude that a properly constructed independent binary collision theory would have a wide range of applicability.