Fluid-solid phase-separation in hard-sphere mixtures is unrelated to bond-percolation

In a recent letter, Buhot proposes that entropy driven phase-separation in hard-core binary mixtures is directly related to a bond-percolation transition. However, at least for binary hard-sphere mixtures, calculations based on an accurate approximation to g_{ll}(r) demonstrate that n_b varies widely along the phase-boundaries calculated directly by simulations, implying that bond-percolation is unrelated to the phase-separation in these systems.Comment: Comment, 1 page, to appear in Phys. Rev. Let

Storing carbon in soil. Can we slow a revolving door?

There is no doubt that soils are a vast store of carbon and partially control the carbon dioxide content of the atmosphere. Maintaining soil organic matter is also crucial for production and environmental protection. Land-use change and management practices are central to maintaining soil carbon, because these can both increase and decrease soil carbon. Pasture systems can store large amounts of soil carbon and there may be an opportunity to store more in New Zealand dairy systems with multiple benefits. Active research is investigating approaches to achieve this goal through the New Zealand Agricultural Greenhouse Gas Research Centre

New collections and records for earwigflies and scorpionflies (Mecoptera: Meropeidae and Panorpidae) in Florida

I add new collection and phenological data on the North American earwigfly, Merope tuber Newman, and new county records for the red scorpionfly, Panorpa rufa Gray, and veined scorpionfly, Panorpa venosa Westwood, in Florida. Additionally, I report on a new Georgia county record for the extralimital species, Panorpa ferruginea Byers, the ferruginous scorpionfly, and speculate on its potential occurrence in Florida

Investigation of Techniques for Simulating Communications and Tracking Subsystems on Space Station Freedom

The need to reduce the costs of Space Station Freedom has resulted in a major redesign and downsizing of the Station in general, and its Communications and Tracking (C&T) components in particular. Earlier models and simulations of the C&T Space-to-Ground Subsystem (SGS) in particular are no longer valid. There thus exists a general need for updated, high fidelity simulations of C&T subsystems. This project explored simulation techniques and methods that might be used in developing new simulations of C&T subsystems, including the SGS. Three requirements were placed on the simulations to be developed: (1) they run on IBM PC/XT/AT compatible computers; (2) they be written in Ada as much as possible; and (3) since control and monitoring of the C&T subsystems will involve communication via a MIL-STD-1553B serial bus, that the possibility of commanding the simulator and monitoring its sensors via that bus be included in the design of the simulator. The result of the project is a prototype of a simulation of the Assembly/Contingency Transponder of the SGS, written in Ada, which can be controlled from another PC via a MIL-STD-1553B bus

Etymology of the earwigfly, Merope tuber Newman (Mecoptera: Meropeidae): Simply dull or just inscrutable?

The naturalist Edward Newman did not provide an etymology for the mecopteran Merope tuber when he described it in 1838. In 1872 Asa Fitch asserted that the genus was named after Merope one of the Pleiades sisters of Greek mythology; however, he provided no reason for his assumption. We researched several etymological alternatives. We concur with Fitch and conclude that Newman did indeed name the genus Merope after the dullest of the Pleiades sisters