Phonons in potassium doped graphene: the effects of electron-phonon interactions, dimensionality and ad-atom ordering

Graphene phonons are measured as a function of electron doping via the addition of potassium adatoms. In the low doping regime, the in-plane carbon G-peak hardens and narrows with increasing doping, analogous to the trend seen in graphene doped via the field-effect. At high dopings, beyond those accessible by the field-effect, the G-peak strongly softens and broadens. This is interpreted as a dynamic, non-adiabatic renormalization of the phonon self-energy. At dopings between the light and heavily doped regimes, we find a robust inhomogeneous phase where the potassium coverage is segregated into regions of high and low density. The phonon energies, linewidths and tunability are remarkably similar for 1-4 layer graphene, but significantly different to doped bulk graphite.Comment: Accepted in Phys. Rev. B as a Rapid Communication. 5 pages, 3 figures, revised text with additional dat

Consent v. Closure

Claimants, defendants, courts, and counsel are understandably frustrated by the difficulty of resolving mass tort cases. Defendants demand closure, but class certification has proved elusive and non-class settlements require individual consent. Lawyers and scholars have been drawn to strategies that solve the problem by empowering plaintiffs’ counsel to negotiate package deals that effectively sidestep individual consent. In the massive Vioxx settlement, the parties achieved closure by including terms that made it unrealistic for any claimant to decline. The American Law Institute’s Principles of the Law of Aggregate Litigation offers another path to closure: it proposes to permit clients to consent in advance to be bound by a settlement with a supermajority vote. This article argues that, despite their appeal, both of these strategies must be rejected. Lawyer empowerment strategies render settlements illegitimate when they rely on inauthentic consent or place lawyers in the untenable position of allocating funds among bound clients. Consent, not closure, is the touchstone of legitimacy in mass tort settlements

Consent v. Closure

Claimants, defendants, courts, and counsel are understandably frustrated by the difficulty of resolving mass tort cases. Defendants demand closure, but class certification has proved elusive and non-class settlements require individual consent. Lawyers and scholars have been drawn to strategies that solve the problem by empowering plaintiffs’ counsel to negotiate package deals that effectively sidestep individual consent. In the massive Vioxx settlement, the parties achieved closure by including terms that made it unrealistic for any claimant to decline. The American Law Institute’s Principles of the Law of Aggregate Litigation offers another path to closure: it proposes to permit clients to consent in advance to be bound by a settlement with a supermajority vote. This article argues that, despite their appeal, both of these strategies must be rejected. Lawyer empowerment strategies render settlements illegitimate when they rely on inauthentic consent or place lawyers in the untenable position of allocating funds among bound clients. Consent, not closure, is the touchstone of legitimacy in mass tort settlements

Synthetic Mechanochemical Molecular Swimmer

A minimal design for a molecular swimmer is proposed that is a based on a mechanochemical propulsion mechanism. Conformational changes are induced by electrostatic actuation when specific parts of the molecule temporarily acquire net charges through catalyzed chemical reactions involving ionic components. The mechanochemical cycle is designed such that the resulting conformational changes would be sufficient for achieving low Reynolds number propulsion. The system is analyzed within the recently developed framework of stochastic swimmers to take account of the noisy environment at the molecular scale. The swimming velocity of the device is found to depend on the concentration of the fuel molecule according to the Michaelis-Menten rule in enzymatic reactions.Comment: 4 pages, 3 figure

Integrated structure electromagnetic optimization of large space antenna reflectors

The requirements for extremely precise and powerful large space antenna reflectors have motivated the development of a procedure for shape control of the reflector surface. A mathematical optimization procedure has been developed which improves antenna performance while minimizing necessary shape correction effort. In contrast to previous work which proposed controlling the rms distortion error of the surface thereby indirectly improving antenna performance, the current work includes electromagnetic (EM) performance calculations as an integral of the control procedure. The application of the procedure to a radiometer design with a tetrahedral truss backup structure demonstrates the potential for significant improvement. The results indicate the benefit of including EM performance calculations in procedures for shape control of large space antenna reflectors

Improved efficiency of nutrient and water use for high quality field vegetable production using fertigation

Drip-based fertigation may improve the application efficiency of water and nutrients while maintaining or improving marketable yield and quality at harvest and post-harvest. Two plantings of lettuce (Lactuca sativa) were grown in the UK, with six N treatments and two methods of irrigation and N application. The conventional overhead irrigated treatments had all N applied in the base dressing with irrigation scheduled from SMD calculations. The closed loop treatments had nitrogen and irrigation delivered via drip automatically controlled by a sensor and logger system. The work established that water content in the root zone can be monitored in real time using horizontally oriented soil moisture sensors linked to data logging and telemetry, and that these data can be used to automatically trigger drip irrigation for commercially grown field vegetables. When the closed loop irrigation control was combined with fertigation treatments, lettuce crops were grown with savings of up to 60% and 75% of water and nitrogen respectively, compared to standard UK production systems. However, excess supply of N through fertigation rather than solid fertiliser was more detrimental to marketable yield and post harvest quality highlighting that care is needed when selecting N rates for fertigation

High-Speed Projects in the United States: Identifying the Elements for Success-Part 1, MTI Report 05-01

For almost half a century, high-speed ground transportation (HSGT) has held the promise of fast, convenient, and environmentally sound travel for distances between 40 and 600 miles. While a number of HSGT systems have been developed and deployed in Asia and Europe, none has come close to being implemented in the United States. Yet this is not for lack of trying. There have been several efforts around the country, most of which have failed, some of which are still in the early stages, and a few of which might come to pass. The goal of this study was to identify lessons learned for successfully developing and implementing high-speed rail (HSR) in the United States. Through a broad literature review, interviews, and three specific case studies—Florida, California, and the Pacific Northwest—this study articulates those lessons and presents themes for future consideration