Universal collisionless transport of graphene

The impact of the electron-electron Coulomb interaction on the optical conductivity of graphene has led to a controversy that calls into question the universality of collisionless transport in this and other Dirac materials. Using a lattice calculation that avoids divergences present in previous nodal Dirac approaches, our work settles this controversy and obtains results in quantitative agreement with experiment over a wide frequency range. We also demonstrate that dimensional regularization methods agree, as long as the scaling properties of the conductivity and the regularization of the theory in modified dimension are correctly implemented. Tight-binding lattice and nodal Dirac theory calculations are shown to coincide at low energies even when the non-zero size of the atomic orbital wave function is included, conclusively demonstrating the universality of the optical conductivity of graphene.Comment: 4+ pages,4 figures; includes Supplemental Material (18 pages, 2 figures

COOPERATIVE SIGNALING BEHAVIOR: SIGNALS FOR OPEN SOURCE PROJECT HEALTH

The core contribution is a critique of signaling theory from investigating cooperative signaling behavior in the context of organizational engagement with open source projects. Open source projects display signals of project health which are used by organizations. Projects and organizations engage in cooperative signaling behavior when they work together to create signals. Signaling theory is critiqued in the cooperative context of organizational engagements with open source projects by describing how cooperative signaling behavior occurs in three processes: identifying, evaluating, and filtering new signals. The contribution is informed through engaged field research and interviews, which are presented as a thick description of the CHAOSS Diversity & Inclusion Working Group and of how its community members create D&I signals. A contribution to literature on open source is a description of how signals for open source project health are created

TREFF: Reflectometer and instrument component test beamline at MLZ

TREFF is a high resolution polarized neutron reflectometer and instrument component test beamline resulting in a highly modular instrument providing a flexible beam line for various applications

Virtual colonoscopy; real misses

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72356/1/j.1572-0241.2003.08448.x.pd

Using productivity and susceptibility indices to assess the vulnerability of United States fish stocks to overfishing

Assessing the vulnerability of stocks to fishing practices in U.S. federal waters was recently highlighted by the National Marine Fisheries Service (NMFS), National Oceanic and Atmospheric Administration, as an important factor to consider when 1) identifying stocks that should be managed and protected under a fishery management plan; 2) grouping data-poor stocks into relevant management complexes; and 3) developing precautionary harvest control rules. To assist the regional fishery management councils in determining vulnerability, NMFS elected to use a modified version of a productivity and susceptibility analysis (PSA) because it can be based on qualitative data, has a history of use in other fisheries, and is recommended by several organizations as a reasonable approach for evaluating risk. A number of productivity and susceptibility attributes for a stock are used in a PSA and from these attributes, index scores and measures of uncertainty are computed and graphically displayed. To demonstrate the utility of the resulting vulnerability evaluation, we evaluated six U.S. fisheries targeting 162 stocks that exhibited varying degrees of productivity and susceptibility, and for which data quality varied. Overall, the PSA was capable of differentiating the vulnerability of stocks along the gradient of susceptibility and productivity indices, although fixed thresholds separating low-, moderate-, and highly vulnerable species were not observed. The PSA can be used as a flexible tool that can incorporate regional-specific information on fishery and management activity

Unit Commitment for Systems With Significant Wind Penetration

The stochastic nature of wind alters the unit commitment and dispatch problem. By accounting for this uncertainty when scheduling the system, more robust schedules are produced, which should, on average, reduce expected costs. In this paper, the effects of stochastic wind and load on the unit commitment and dispatch of power systems with high levels of wind power are examined. By comparing the costs, planned operation and performance of the schedules produced, it is shown that stochastic optimization results in less costly, of the order of 0.25%, and better performing schedules than deterministic optimization. The impact of planning the system more frequently to account for updated wind and load forecasts is then examined. More frequent planning means more up to date forecasts are used, which reduces the need for reserve and increases performance of the schedules. It is shown that mid-merit and peaking units and the interconnection are the most affected parts of the system where uncertainty of wind is concerned.Science Foundation IrelandElectricity Research Centre (ERC) Industry Memberske SB. 26/7/1