Transition from viscous to inertial regime in dense suspensions

Non-Brownian suspensions present a transition from Newtonian behavior in the zero-shear limit to a shear thickening behaviour at a large shear rate, none of which is clearly understood so far. Here, we carry out numerical simulations of such an athermal dense suspension under shear, at an imposed confining pressure. This set-up is conceptually identical to the recent experiments of Boyer and co-workers [Phys. Rev. Lett. 107,188301 (2011)]. Varying the interstitial fluid viscosities, we recover the Newtonian and Bagnoldian regimes and show that they correspond to a dissipation dominated by viscous and contact forces respectively. We show that the two rheological regimes can be unified as a function of a single dimensionless number, by adding the contributions to the dissipation at a given volume fraction.Comment: 4 pages, 3 figure

The ongoing contributions of spin-off research and practice to understanding corporate restructuring and wealth creation: $100 billion in 1 decade

AbstractSince the 1980s, analysis of spin-offs has become a key line of inquiry in corporate finance. This paper reviews the theory and empirical research papers about spin-off restructuring and measures the monetary value created by spin-offs. First, we document the valuation impact of spin-offs for the divesting firms and then examine such subtleties as the interesting (positive) ex-dividend day price impact and the myriad other details associated with these transactions. This study provides a review of the now extensive research into spin-off divestitures. It looks into equity price reactions around the announcements of 249 voluntary spin-offs undertaken by US public companies over the interval 2007–2017. The abnormal returns associated with recent spin-off divestitures are of the same order of magnitude as those from the earlier papers, showing the sustained statistical significance and new economic materiality measures. With more firms undertaking spin-offs and the positive abnormal returns continuing to be substantial, the clear implication is that the overall monetary value creation resulting from spin-offs has increased markedly. Finally, and in a first for spin-off research, this paper calibrates the monetary value created by spin-offs despite the voluminous research of the topic. It establishes that spin-offs create large monetary value increments for divesting a firm's stockholders—almost $100 billion in the interval 2007–2017

Lagrangian tracers on a surface flow: the role of time correlations

Finite time correlations of the velocity in a surface flow are found to be important for the formation of clusters of Lagrangian tracers. The degree of clustering characterized by the Lyapunov spectrum of the flow is numerically shown to be in qualitative agreement with the predictions for the white-in-time compressible Kraichnan flow, but to deviate quantitatively. For intermediate values of compressibility the clustering is surprisingly weakened by time correlations.Comment: 4 pages, 5 figures, to be published in PR

The extent of NGC 6822 revealed by its C stars population

Using the CFH12K camera, we apply the four band photometric technique to identify 904 carbon stars in an area 28' x 42' centered on NGC 6822. A few C stars, outside of this area were also discovered with the Las Campanas Swope Telescope. The NGC 6822 C star population has an average I of 19.26 mag leading to an average absolute I magnitude of -4.70 mag, a value essentially identical to the mean magnitude obtained for the C stars in IC 1613. Contrary to stars highlighting the optical image of NGC 6822, C stars are seen at large radial distances and trace a huge slightly elliptical halo which do not coincide with the huge HI cloud surrounding NGC6822. The previously unknown stellar component of NGC 6822 has a exponential scale length of 3.0' +/- 0.1' and can be traced to five scale lengths. The C/M ratio of NGC 6822 is evaluated to br 1.0 +/- 0.2.Comment: accepted, to be published in A

On non-L2L^2 solutions to the Seiberg-Witten equations

We show that a previous paper of Freund describing a solution to the Seiberg-Witten equations has a sign error rendering it a solution to a related but different set of equations. The non-$L^2$ nature of Freund's solution is discussed and clarified and we also construct a whole class of solutions to the Seiberg-Witten equations.Comment: 8 pages, Te

Exponential behavior of the interlayer exchange coupling across non-magnetic metallic superlattices

It is shown that the coupling between magnetic layers separated by non-magnetic metallic superlattices can decay exponentially as a function of the spacer thickness $N$, as opposed to the usual $N^{-2}$ decay. This effect is due to the lack of constructive contributions to the coupling from extended states across the spacer. The exponential behavior is obtained by properly choosing the distinct metals and the superlattice unit cell composition.Comment: To appear in Phys. Rev.

On-Farm Food Safety and Environmental Farm Plans: A Conceptual Framework for Identifying and Classifying Benefits and Costs

This series of six reports entitled: "On-Farm Food Safety and Environmental Farm Plans: Identifying and Classifying Benefits and Costs" was initiated soon after the launch of the Agricultural Policy Framework (APF) in 2002. The APF recognized the importance of food safety and environmental concerns for the future growth of the agriculture and Agri-food sector. For this reason, Agriculture and Agri-Food Canada (AAFC) commissioned this series of reports to develop a conceptual framework to strengthen our understanding of the potential benefit and cost implications of On-farm Food Safety (OFFS) and Environmental Farm Plans (EFP) that were key components of the APF. The reports were prepared by a group of academics with extensive knowledge of the agriculture and Agri-food sector and issues related to food safety, traceability and the environment. The first report presents a summary of the findings in the five main reports in the series. The second report presents the conceptual framework that was developed to help identify qualitatively the potential benefits and costs that the various players in the agriculture and agri-food supply chain would face in implementing OFFS and EFP programs. The third report applies this framework to pork, the fourth, to beef, the fifth, to grains and the sixth, to dairy. In general, benefits and costs are divided into both demand and supply side effects. In addition, both public and private costs and benefits are considered, especially since they help indicate where a role for government might be required and where markets are not working as well as they might. Based on these preliminary qualitative assessments, the beef and pork sector have more to gain from HACCP-based OFFS and EFP initiatives, due to their ability to gain market share from marketing their products internationally, while the grains sector already benefits internationally from its high quality reputation and the dairy sector is restricted to produce only for the domestic market. However, more work is required in these areas to validate and quantify costs and benefits.Agribusiness, Agricultural and Food Policy, Environmental Economics and Policy, Food Consumption/Nutrition/Food Safety, Production Economics, Resource /Energy Economics and Policy,