5,196 research outputs found
Magnetism of Covalently Functionalized Carbon Nanotubes
We investigate the electronic structure of carbon nanotubes functionalized by
adsorbates anchored with single C-C covalent bonds. We find that, despite the
particular adsorbate, a spin moment with a universal value of 1.0 per
molecule is induced at low coverage. Therefore, we propose a mechanism of
bonding-induced magnetism at the carbon surface. The adsorption of a single
molecule creates a dispersionless defect state at the Fermi energy, which is
mainly localized in the carbon wall and presents a small contribution from the
adsorbate. This universal spin moment is fairly independent of the coverage as
long as all the molecules occupy the same graphenic sublattice. The magnetic
coupling between adsorbates is also studied and reveals a key dependence on the
graphenic sublattice adsorption site.Comment: final version, improved discussion about calculations and defect
concentratio
On Consumers' Attitudes and Willingness to Pay for Improved Drinking Water Quality and Infrastructure
Replaced with revised version of paper 07/23/09.willingness to pay, risk perceptions, water infrastructure, simultaneous equation model, Environmental Economics and Policy,
Iterated function systems with a given continuous stationary distribution
For any continuous probability measure on we construct an
IFS with probabilities having as its unique measure-attractor.Comment: 7 pages, 3 figure
The impact on a primary school community in England of failed inspection and subsequent academisation
© 2015 Taylor & Francis. This research reports upon the impact of two concurrent processes of Special Measures and academisation applied to a primary school in the north of England as a result of an unsatisfactory inspection by the Office for Standards in Education (Ofsted). The aim of the study is to describe how the process of being placed in special measures, coupled with subsequent academisation, affected key school facing stakeholders. Data collection commenced from when the school received the judgement about its performance from Ofsted. This paper will examine the emerging themes during the first phase of the process of school transformation
Optimum Centralized Portfolio Construction with Decentralized Portfolio Management
Many financial institutions employ outside portfolio managers to manage part or all of their investable assets. These institutions include pension funds, private endowments (e.g., colleges and charities), and private trusts. Pension funds are the largest and most likely organizations to employ several outside managers, each of whom manages a part of the overall portfolio. In this paper we will use the pension fund manager as the prototype of the centralized decision-maker trying to optimally manage a set of decentralized decision-makers but the analysts is general. If the centralized decision-maker (CDM) is a mean variance maximizer, the CDM could construct a portfolio using standard portfolio theory and estimates of mean return, variances, and covariances between the portfolios constructed by a group of decentralized managers. However, this overall portfolio is unlikely to be optimum since the individually managed portfolios themselves were constructed without taking into account the portfolios of the other managers. The purpose of this article is to set up a structure that leads to the optimum portfolio from the viewpoint of the CDM when there are multiple managers and their portfolios are constructed without reference to each other
OPTIMUM CENTRALIZED PORTFOLIO CONSTRUCTION WITH DECENTRALIZED PORTFOLIO MANAGEMENT
Many financial institutions employ outside portfolio managers to manage part or all of their investable assets. These institutions include pension funds, private endowments (e.g., colleges and charities), and private trusts. Pension funds are the largest and most likely organizations to employ several outside managers, each of whom manages a part of the overall portfolio. In this paper we will use the pension fund manager as the prototype of the centralized decision-maker trying to optimally manage a set of decentralized decision-makers but the analysts is general. If the centralized decision-maker (CDM) is a mean variance maximizer, the CDM could construct a portfolio using standard portfolio theory and estimates of mean return, variances, and covariances between the portfolios constructed by a group of decentralized managers. However, this overall portfolio is unlikely to be optimum since the individually managed portfolios themselves were constructed without taking into account the portfolios of the other managers. The purpose of this article is to set up a structure that leads to the optimum portfolio from the viewpoint of the CDM when there are multiple managers and their portfolios are constructed without reference to each other
Macaques at the margins: the biogeography and extinction of Macaca sylvanus in Europe
The genus Macaca (Primates: Cercopithecidae) originated in Africa, dispersed into Europe in the Late Miocene and resided there until the Late Pleistocene. In this contribution, we provide an overview of the evolutionary history of Macaca in Europe, putting it into context with the wider late Miocene, Pliocene and Pleistocene European monkey fossil record (also comprising Mesopithecus, Paradolichopithecus, Dolichopithecus and Theropithecus). The Pliocene and Pleistocene European Macaca fossil material is largely regarded as Macaca sylvanus, the same species as the extant Barbary macaque in North Africa. The M. sylvanus specimens found at West Runton in Norfolk (53°N) during the Middle Pleistocene are among the most northerly euprimates ever discovered. Our simple time-budget model indicates that short winter day lengths would have imposed a significant constraint on activity at such relatively high latitudes, so macaque populations in Britain may have been at the limit of their ecological tolerance. Two basic models using climatic and topographic data for the Last Interglacial and the Last Glacial Maximum alongside Middle and Late Pleistocene fossil distributions indicate that much of Europe may have been suitable habitat for macaques. The models also indicate that areas of southern Europe in the present day have a climate that could support macaque populations. However, M. sylvanus became locally extinct in the Late Pleistocene, possibly at a similar time as the straight-tusked elephant, Palaeoloxodon antiquus, and narrow-nosed rhinoceros, Stephanorhinus hemitoechus. Its extinction may be related to vegetation change or increased predation from Homo, although other factors (such as stochastic factors occurring as a result of small population sizes) cannot be ruled out. Notwithstanding the cause of extinction, the European macaque may thus be a previously overlooked member of the Late Pleistocene faunal turnover
The longitudinal thickness of air-shower fronts
Linsely (1983) has proposed a technique for the detection and analysis of air showers at large distances from the shower axis based on a measurement of the shower front thickness and the assumption that this thickness is closely related to the core distance. Some of the problems involved with realizing such a technique were investigated, and some related observations are reported. The practical problems of how consistent the measurements of the shower front would be, how one would use the measurement, and how the rate of triggered events would depend on the minimum pulse width required are studied
Cauliflower, a New Recessive Mutation in Tomato
Author Institution: Department of Botany and Plant Pathology, The Ohio State University, Columbus 10, and The Ohio Agricultural Experiment Station, Wooste
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