A moving boundary problem arising from the diffusion of oxygen in absorbing tissue

Approximate analytical and numerical solutions of a partial differential equation are obtained which describe the diffusion of oxygen in an absorbing medium. Essential mathematical difficulties are associated with the presence of a moving boundary which marks the furthest penetration of oxygen into the medium and also with the need to allow for an initial distribution of oxygen through the medium

A method for solving moving boundary problems in heat flow Part I: Using cubic splines

A new approach to a heat-flow problem involving a moving boundary makes use of a grid system which moves with the boundary. The necessary interpolations are performed by using cubic splines. The method smooths out irregularities in the motion of the boundary which were evident in previous calculations based on a fixed grid system

A method for solving moving boundary problems in heat flow part ii: Using cubic polynomials

A moving grid system has been used to get the solution of the moving boundary problem discussed earlier in Part I, but basing the necessary interpolations on ordinary cubic polynomials rather than splines. The computations are much more economical and the results obtained are also found to he more satiafactory

Weighted Density Approximation Description of Insulating YH3_3 and LaH3_3

Density functional calculations within the weighted density approximation (WDA) are presented for YH$_3$ and LaH$_3$. We investigate some commonly used pair-distribution functions G. These calculations show that within a consistent density functional framework a substantial insulating gap can be obtained while at the same time retaining structural properties in accord with experimental data. Our WDA band structures agree with those of $GW$ approximation very well, but the calculated band gaps are still 1.0-2.0 eV smaller than experimental findings.Comment: 6 Pages, 3 figure

Dynamical cluster-decay model for hot and rotating light-mass nuclear systems, applied to low-energy 32^{32}S + 24^{24}Mg →56\to ^{56}Ni reaction

The dynamical cluster-decay model (DCM) is developed further for the decay of hot and rotating compound nuclei (CN) formed in light heavy-ion reactions. The model is worked out in terms of only one parameter, namely the neck-length parameter, which is related to the total kinetic energy TKE(T) or effective Q-value $Q_{eff}(T)$ at temperature T of the hot CN, defined in terms of the both the light-particles (LP), with $A \leq$ 4, Z $\leq$ 2, as well as the complex intermediate mass fragments (IMF), with $4 2$, is considered as the dynamical collective mass motion of preformed clusters through the barrier. Within the same dynamical model treatment, the LPs are shown to have different characteristics as compared to the IMFs. The systematic variation of the LP emission cross section $\sigma_{LP}$, and IMF emission cross section $\sigma_{IMF}$, calculated on the present DCM match exactly the statistical fission model predictions. It is for the first time that a non-statistical dynamical description is developed for the emission of light-particles from the hot and rotating CN. The model is applied to the decay of $^{56}$Ni formed in the $^{32}$S + $^{24}$Mg reaction at two incident energies E$_{c.m.}$ = 51.6 and 60.5 MeV. Both the IMFs and average $\bar{TKE}$ spectra are found to compare reasonably nicely with the experimental data, favoring asymmetric mass distributions. The LPs emission cross section is shown to depend strongly on the type of emitted particles and their multiplicities

Subsidiary capability upgrading and parent-subsidiary relationship: insights from a Chinese acquisition in the UK

Purpose: - This study aims to explore capability upgrading of EMNE’s subsidiaries in developed countries and how the parent-subsidiary relationship influences such upgrading. Design/methodology/approach: - The study adopts an interdisciplinary approach to capability upgrading of EMNEs subsidiaries in developed countries. It employs a single case study to explore this under-research area. Finding: - the analysis challenges the orthodox view and suggests broad based capability upgrading has taken place in the EMNE acquired subsidiaries ranging from product, process, functional to intersectoral. In addition, the capability upgrading was contingent on the degree of subsidiary autonomy and subsidiary mandates. Originality/value: - This study represents one of the first to examine capability upgrading and parent-subsidiary relationship in the context of EMNEs’ internationalisation activities

Topological Density and Instantons on a Lattice

We present an update on the study of topological structure of QCD. Issues addressed include a comparison between the plaquette and the geometric methods of calculating the topological density. We show that the improved gauge action based on sqrt(3) blocking transformation suppresses the formation of topologically charged dislocations with low action. Using a cooling method we identify the instantons' location, estimate their size and density, and calculate the renormalization constant Z_Q for the plaquette method.Comment: 3 Pages, submitted to Proceedings of XII International Symposium on Lattice Field Theory (Lattice 94, Bielefeld). uuencoded tar file includes figures as TeXDraw (.tex) file

Emission of intermediate mass fragments from hot 116^{116}Ba∗^* formed in low-energy 58^{58}Ni+58^{58}Ni reaction

The complex fragments (or intermediate mass fragments) observed in the low-energy $^{58}$Ni+$^{58}$Ni$\to ^{116}$Ba$^*$ reaction, are studied within the dynamical cluster decay model for s-wave with the use of the temperature-dependent liquid drop, Coulomb and proximity energies. The important result is that, due to the temperature effects in liquid drop energy, the explicit preference for $\alpha$-like fragments is washed out, though the $^{12}$C (or the complementary $^{104}$Sn) decay is still predicted to be one of the most probable $\alpha$-nucleus decay for this reaction. The production rates for non-$\alpha$ like intermediate mass fragments (IMFs) are now higher and the light particle production is shown to accompany the IMFs at all incident energies, without involving any statistical evaporation process in the model. The comparisons between the experimental data and the (s-wave) calculations for IMFs production cross sections are rather satisfactory and the contributions from other $\ell$-waves need to be added for a further improvement of these comparisons and for calculations of the total kinetic energies of fragments.Comment: 22 pages, 15 figure

Pulsed radiolysis of model aromatic polymers and epoxy based matrix materials

Models of primary processes leading to deactivation of energy deposited by a pulse of high energy electrons were derived for epoxy matrix materials and polyl-vinyl naphthalene. The basic conclusion is that recombination of initially formed charged states is complete within 1 nanosecond, and subsequent degradation chemistry is controlled by the reactivity of these excited states. Excited states in both systems form complexes with ground state molecules. These excimers or exciplexes have their characteristics emissive and absorptive properties and may decay to form separated pairs of ground state molecules, cross over to the triplet manifold or emit fluorescence. ESR studies and chemical analyses subsequent to pulse radiolysis were performed in order to estimate bond cleavage probabilities and net reaction rates. The energy deactivation models which were proposed to interpret these data have led to the development of radiation stabilization criteria for these systems