On weak shock diffraction in real gases

Asymptotic solutions are obtained for the two-dimensional Euler system for real gases with appropriate boundary conditions which describe the diffraction of a weak shock at a right-angled wedge; the real gas effects are characterized by a van der Waals type equation of state. The behavior of the flow configuration influenced by the real gas effects, that includes the local structure near a singular point, is studied in detail.Comment: 14 pages, 1 figure. arXiv admin note: substantial text overlap with arXiv:1405.066

Magnetization in electron- and Mn- doped SrTiO3

Mn-doped SrTiO_3.0, when synthesized free of impurities, is a paramagnetic insulator with interesting dielectric properties. Since delocalized charge carriers are known to promote ferromagnetism in a large number of systems via diverse mechanisms, we have looked for the possibility of any intrinsic, spontaneous magnetization by simultaneous doping of Mn ions and electrons into SrTiO_3 via oxygen vacancies, thereby forming SrTi_(1-x)Mn_xO_(3-d), to the extent of making the doped system metallic. We find an absence of any enhancement of the magnetization in the metallic sample when compared with a similarly prepared Mn doped, however, insulating sample. Our results, thus, are not in agreement with a recent observation of a weak ferromagnetism in metallic Mn doped SrTiO_3 system.Comment: 10 pages and 4 figure

Environmental Initiatives and Earnings Management

Purpose – The purpose of this paper is to provide initial evidence on the association between environmental initiatives and earnings management. Prior literature documents firms participating in environmental initiatives to report relatively stronger financial performance. Moreover, firms with superior performance have been shown to engage in greater levels of earnings management. A natural question that arises is to what extent do firms with environmental initiatives engage in earnings management to report better financial performance? Design/methodology/approach – The study draws on two theoretical frameworks, external monitoring and internal corporate culture, to predict an inverse association between environmental initiatives and earnings management. The authors test this prediction using an earnings management regression model, estimating discretionary accruals using the modified-Jones approach. Findings – The study finds that firms with environmental initiatives exhibit lower earnings management proxied by absolute and income-increasing total discretionary accruals. The authors further find pollution prevention and climate related initiatives to help explain this inverse association. The results imply that firms practising environmental responsibility report better financial performance, with the most likely reason being due to real economic performance rather than through earnings management techniques. Originality/value – This study provides initial evidence on the association between environmental initiatives and earnings management, an area of importance to all stakeholders in a market with increasing interest in corporate environmental performance and its implications

Anomalies at finite density and chiral fermions

Using perturbation theory in the Euclidean (imaginary time) formalism as well as the non-perturbative Fujikawa method, we verify that the chiral anomaly equation remains unaffected in the presence of nonzero chemical potential, $\mu$. We extend our considerations to fermions with exact chiral symmetry on the lattice and discuss the consequences for the recent Bloch-Wettig proposal for the Dirac operator at finite chemical potential. We propose a new simpler method of incorporating $\mu$ and compare it with the Bloch-Wettig idea.Comment: 12 pages, 3 figures,some typos corrected, a better proof for the \mu independence of anomaly is given in section IIB, v4: the published versio

An Application of Distributional Two Dimensional Fourier-Mellin Transform

Integral transforms are linear continuous operators with their inverses, transforming a class of functions to another class of functions or sequences. They provide powerful operational methods for solving initial value problems and initial-boundary value problems for linear differential and integral equations. With ever greater demand for mathematical methods to provide a both theory and applications for science and engineering, the utility and interest of integral transforms seems more clearly established than ever. In spite of the fact that integral transforms have many mathematical and physical applications, their use is still predominant in advanced study and research. Keeping these features in mind in this paper we provide the solution of differential equation for the distributional two dimensional Fourier-Mellin transform of the type P(⋀_(t,l,x,y)^* ) u(t,l,x,y)=f(t,l,x,y) and P(D_(t,l,x,y) )u(t,l,x,y)=f(t,l,x,y) using the differential operator ⋀_(t,l,x,y) and ⋀_(t,l,x,y)^*