Development of intermolecular potential models for electrolyte solutions using an electrolyte SAFT-VR Mie equation of state

We present a theoretical framework and parameterisation of intermolecular potentials for aqueous electrolyte solutions using the statistical associating fluid theory based on the Mie interaction potential (SAFT-VR Mie), coupled with the primitive, non-restricted mean-spherical approximation (MSA) for electrolytes. In common with other SAFT approaches, water is modelled as a spherical molecule with four off-centre association sites to represent the hydrogen-bonding interactions; the repulsive and dispersive interactions between the molecular cores are represented with a potential of the Mie (generalised Lennard-Jones) form. The ionic species are modelled as fully dissociated, and each ion is treated as spherical: Coulombic ion–ion interactions are included at the centre of a Mie core; the ion–water interactions are also modelled with a Mie potential without an explicit treatment of ion–dipole interaction. A Born contribution to the Helmholtz free energy of the system is included to account for the process of charging the ions in the aqueous dielectric medium. The parameterisation of the ion potential models is simplified by representing the ion–ion dispersive interaction energies with a modified version of the London theory for the unlike attractions. By combining the Shannon estimates of the size of the ionic species with the Born cavity size reported by Rashin and Honig, the parameterisation of the model is reduced to the determination of a single ion–solvent attractive interaction parameter. The resulting SAFT-VRE Mie parameter sets allow one to accurately reproduce the densities, vapour pressures, and osmotic coefficients for a broad variety of aqueous electrolyte solutions; the activity coefficients of the ions, which are not used in the parameterisation of the models, are also found to be in good agreement with the experimental data. The models are shown to be reliable beyond the molality range considered during parameter estimation. The inclusion of the Born free-energy contribution, together with appropriate estimates for the size of the ionic cavity, allows for accurate predictions of the Gibbs free energy of solvation of the ionic species considered. The solubility limits are also predicted for a number of salts; in cases where reliable reference data are available the predictions are in good agreement with experiment

Real space tests of the statistical isotropy and Gaussianity of the WMAP CMB data

ABRIDGED: We introduce and analyze a method for testing statistical isotropy and Gaussianity and apply it to the WMAP CMB foreground reduced, temperature maps, and cross-channel difference maps. We divide the sky into regions of varying size and shape and measure the first four moments of the one-point distribution within these regions, and using their simulated spatial distributions we test the statistical isotropy and Gaussianity hypotheses. By randomly varying orientations of these regions, we sample the underlying CMB field in a new manner, that offers a richer exploration of the data content, and avoids possible biasing due to a single choice of sky division. The statistical significance is assessed via comparison with realistic Monte-Carlo simulations. We find the three-year WMAP maps to agree well with the isotropic, Gaussian random field simulations as probed by regions corresponding to the angular scales ranging from 6 deg to 30 deg at 68% confidence level. We report a strong, anomalous (99.8% CL) dipole ``excess'' in the V band of the three-year WMAP data and also in the V band of the WMAP five-year data (99.3% CL). We notice the large scale hemispherical power asymmetry, and find that it is not highly statistically significant in the WMAP three-year data (<~ 97%) at scales l <= 40. The significance is even smaller if multipoles up to l=1024 are considered (~90% CL). We give constraints on the amplitude of the previously-proposed CMB dipole modulation field parameter. We easily detect the residual foregrounds in cross-band difference maps at rms level <~ 7 \mu K (at scales >~ 6 deg) and limit the systematical uncertainties to <~ 1.7 \mu K (at scales >~ 30 deg).Comment: 20 pages, 20 figures; more tests added; updated to match the version to be published in JCA

Systematic Distortion in Cosmic Microwave Background Maps

To minimize instrumentally induced systematic errors, cosmic microwave background (CMB) anisotropy experiments measure temperature differences across the sky using paires of horn antennas, temperature map is recovered from temperature differences obtained in sky survey through a map-making procedure. To inspect and calibrate residual systematic errors in recovered temperature maps is important as most previous studies of cosmology are based on these maps. By analyzing pixel-ring couping and latitude dependence of CMB temperatures, we find notable systematic deviation from CMB Gaussianity in released Wilkinson Microwave Anisotropy Probe (WMAP) maps. The detected deviation is hard to explain by any process in the early universe and can not be ignored for a precision cosmology study.Comment: accepted for publication in Sci China G-Phy Mech Astro

Mathematical modelling of the pathogenesis of multiple myeloma-induced bone disease

Multiple myeloma (MM) is the second most common haematological malignancy and results in destructive bone lesions. The interaction between MM cells and the bone microenvironment plays an important role in the development of the tumour cells and MM-induced bone disease and forms a 'vicious cycle' of tumour development and bone destruction, intensified by suppression of osteoblast activity and promotion of osteoclast activity. In this paper, a mathematical model is proposed to simulate how the interaction between MM cells and the bone microenvironment facilitates the development of the tumour cells and the resultant bone destruction. It includes both the roles of inhibited osteoblast activity and stimulated osteoclast activity. The model is able to mimic the temporal variation of bone cell concentrations and resultant bone volume after the invasion and then removal of the tumour cells and explains why MM-induced bone lesions rarely heal even after the complete removal of MM cells. The behaviour of the model compares well with published experimental data. The model serves as a first step to understand the development of MM-induced bone disease and could be applied further to evaluate the current therapies against MM-induced bone disease and even suggests new potential therapeutic targets

FRW Universe Models in Conformally Flat Spacetime Coordinates. III: Universe models with positive spatial curvature

We deduce general expressions for the line element of universe models with positive spatial curvature described by conformally flat spacetime coordinates. Models with dust, radiation and vacuum energy are exhibited. Discussing the existence of particle horizons we show that there is continual annihilation of space, matter and energy in a dust and radiation dominated universe, and continual creation in a LIVE domined universe when conformal time is used in Friedmann-Robertson-Walker models with positive spatial curvature. A general procedure is given for finding coordinates to be used in Penrose diagrams. We also calculate the age and the redshift of some universe models using conformal time.Comment: 22 pages, 9 figure

Impact of Galactic polarized emission on B-mode detection at low multipoles

We use a model of polarized Galactic emission developed by the the Planck collaboration to assess the impact of foregrounds on B-mode detection at low multipoles. Our main interest is to applications of noisy polarization data and in particular to assessing the feasibility of B-mode detection by Planck. This limits the complexity of foreground subtraction techniques that can be applied to the data. We analyze internal linear combination techniques and show that the offset caused by the dominant E-mode polarization pattern leads to a fundamental limit of r approximately 0.1 for the tensor-scalar ratio even in the absence of instrumental noise. We devise a simple, robust, template fitting technique using multi-frequency polarization maps. We show that template fitting using Planck data alone offers a feasible way of recovering primordial B-modes from dominant foreground contamination, even in the presence of noise on the data and templates. We implement and test a pixel-based scheme for computing the likelihood function of cosmological parameters at low multipoles that incorporates foreground subtraction of noisy data.Comment: 20 pages, 10 figure

FRW Universe Models in Conformally Flat Spacetime Coordinates. II: Universe models with negative and vanishing spatial curvature

We deduce general expressions for the line element of universe models with negative and vanishing spatial curvature described by conformally flat spacetime coordinates. The empty Milne universe model and models with dust, radiation and vacuum energy are exhibited. Discussing the existence of particle horizons we show that there is continual creation of space, matter and energy when conformal time is used in Friedmann-Robertson-Walker models with negative spatial curvature.Comment: 25 pages, 12 figure

Country of ownership influence on brand equity and loyalty

This study aims to investigate the impact of country of ownership on Norwegian consumers' brand attitudes, perceived quality, brand value, and loyalty. As companies increasingly internationalize, it becomes crucial to examine how this may influence brand equity and identify strategies to mitigate any potential negative effects. This knowledge would be beneficial for both national and international companies seeking to enter the Norwegian market. Despite the importance of this topic, there is limited research on the effects of country of ownership on brand equity and loyalty. Given the complexity of the subject and the scarcity of relevant literature, it was essential to incorporate a mediator and a moderator, namely pride and ethnocentrism, into our conceptual model to facilitate a comprehensive understanding of the study results. Our thesis statement is: "What effect does country of ownership have on brand equity and brand loyalty?" To test our conceptual model, we conducted a quantitative experiment using a 2x2 between- groups design, wherein each group was presented with a fictional news article. One article depicted the acquisition of the Norwegian company Tine by a foreign entity, while the other portrayed Tine maintaining its Norwegian ownership. This approach allowed us to explore different scenarios related to country of ownership. Our sample comprised 109 anonymous respondents, who were recruited through diverse social media platforms such as Facebook and LinkedIn. The data analysis was performed using the statistical program SPSS, along with Hayes PROCESS macro, enabling the simultaneous analysis of the entire conceptual model, including the direct and indirect effects of the moderator and mediator. The analysis consisted of exploratory factor analysis (EFA), probability analysis, linear regression analysis, and moderated mediation analysis, specifically Hayes' PROCESS Model 5. Our findings indicated that country of ownership did not exert a significant effect on brand equity or loyalty, leading to the rejection of all six of our hypotheses. Furthermore, ethnocentrism was not found to have a significant moderating effect on the relationship between country of ownership and brand equity or loyalty. The analysis also revealed that country of ownership did not impact the mediator, pride, while pride exhibited a slight positive mediating effect on the relationship between country of ownership and the dependent variable, brand equity, although this effect was not deemed significant. However, pride did exhibit a significant positive mediating effect on brand equity. Although our hypotheses were not supported by the data, our findings hold significance for the field of country of ownership and can guide future research on the subject. Notably, the discovery of pride's significant positive effect on brand equity presents a promising avenue for further investigation

Plane-mirroring anomaly in the cosmic microwave background maps

The plane-mirror symmetry previously noticed in the Cosmic Microwave Background (CMB) temperature anisotropy maps of Wilkinson Microwave Anisotropy Probe is shown to possess certain anomalous properties. The degree of the randomness determined by the Kolmogorov stochasticity parameter in the both symmetry regions appears to have identical values which, however, essentially differ from the corresponding values for other sky regions. If the mirroring were of cosmological origin, this would imply either additional randomizing properties in those directions of the Universe or their different line-of-sight depth. This analysis also provides a way to test the hypothesis of a link between the nature of dark energy and inhomogeneities.Comment: A & A (Lett.) in press; 3 pages, 2 fig

Reactivity difference between protolytic forms of some macrocyclic chromium(III) complexes in ligand substitution and electron transfer processes

The review provides insight into the mechanism of ligand substitution and electron transfer (from chromium( III) to iron(III)) by comparison of the reactivity of some tetraazamacrocyclic chromium(III) complexes in the conjugate acid-base forms. Use of two geometrical isomers made possible to estimate the influence of geometry and protolytic reactions in trans and cis position towards the leaving group on the rate enhancement. Studies on the reaction rates in different media demonstrated the role played by outer sphere interactions in a monodentate ligand substitution