The structure of sheared turbulence near a plane boundary

An analysis is presented of how a plane boundary affects the structure of turbulence in a sheared free stream. A uniform-shear boundary layer (USBL) is formulated with slip velocity condition at the surface, and inhomogeneous rapid distortion theory is applied. The effects of blocking by the surface on the turbulence structure in USBL is compared with those in the shear-free boundary layer (SFBL). Shear produces highly anisotropic eddies elongated in the flow direction. The vertical velocity variance is reduced with shear at all heights, roughly in proportion to the reduction in the homogeneous value, but the shape of the profile remains unchanged only near the surface. The streamwise integral scales increase with shear, indicating elongation of the streamwise extent of eddies

The role of universities in the provision of corporate social responsibility and ethics teaching in the agricultural sector

Few industries have as direct a link between economics and the environment as the agricultural industry (Diebel, 2008) and as such this paper analyses the CSR and ethics teaching in agricultural schools in four English speaking countries. The four countries have distinct policy and cultural differences with regards to areas such as environmental protection, animal welfare and the use of biotechnology. The study analyses the differences between agricultural schools by means of a content analysis of syllabuses for institutions in each of the countries. The analysis finds significant differences in the provision of CSR and ethics teaching as a result of geographical location of the institution although interestingly the analysis failed to yield expected difference in CSR and ethics teaching provision as a result of institutional ranking. Among the most interesting areas for future research as suggested by this review is the analysis of the antecedents of the public’s ethical standing with regard to the agricultural industry. Recent events have seen an increased focus on the role of business schools in the provision of corporate social responsibility (hereinafter CSR) and ethics teaching (Cornelius, Wallace, & Tassabehji, 2007). There has been comparatively little analysis of CSR and ethics teaching provision in other sectors. The subject is of considerable interest to businesses as research has shown that the CSR and ethics which a company displays affects its financial performance (Zairi & Peters 2002; Fombrun & Shanley, 1990). The public increasingly sees businesses as the cause of environmental degradation, (Porter & Kramer, 2011) consumers have as a result become increasingly eco-aware and ethically conscious with regard to their purchasing habits (Wilson, 200). This paper looks at implications for teaching sustainable agriculture

Notes on Spinoptics in a Stationary Spacetime

In arXiv:1105.5629, equations of the modified geometrical optics for circularly polarized photon trajectories in a stationary spacetime are derived by using a (1+3)-decomposed form of Maxwell's equations. We derive the same results by using a four-dimensional covariant description. In our procedure, the null nature of the modified photon trajectory naturally appears and the energy flux is apparently null. We find that, in contrast to the standard geometrical optics, the inner product of the stationary Killing vector and the tangent null vector to the modified photon trajectory is no longer a conserved quantity along light paths. This quantity is furthermore different for left and right handed photon. A similar analysis is performed for gravitational waves and an additional factor of 2 appears in the modification due to the spin-2 nature of gravitational waves.Comment: 15 pages, to appear in PR

Optical propagation through a homogeneous turbulent shear flow

Effects of organized turbulent structures on the propagation of an optical beam in a homogeneous shear flow were studied. A passive-scalar field in a computed turbulent shear flow is used to represent index-of-refraction fluctuations, and phase errors induced in a coherent optical beam by turbulent fluctuations are computed. The organized vortical structures produce a scalar distribution with elongated regions of intense fluctuations which have an inclination with respect to the mean flow similar to that of the characteristic hairpin eddies. It is found that r.m.s. phase error is minimized by propagating approximately normal to the inclined vortical structures. Two-point correlations of vorticity and scalar fluctuation suggest that the regions of intense scalar fluctuation are produced primarily by the hairpin eddies