133 research outputs found
Investigation of the role of neutron transfer in the fusion of 32,34S with 197Au,208Pb using quasi-elastic scattering
Excitation functions for quasi-elastic scattering have been measured at
backward angles for the systems 32,34S+197Au and 32,34S+208Pb for energies
spanning the Coulomb barrier. Representative distributions, sensitive to the
low energy part of the fusion barrier distribution, have been extracted from
the data. For the fusion reactions of 32,34S with 197Au couplings related to
the nuclear structure of 197Au appear to be dominant in shaping the low energy
part of the barrier distibution. For the system 32S+208Pb the barrier
distribution is broader and extends further to lower energies, than in the case
of 34S+208Pb. This is consistent with the interpretation that the neutron
pick-up channels are energetically more favoured in the 32S induced reaction
and therefore couple more strongly to the relative motion. It may also be due
to the increased collectivity of 32S, when compared with 34S.Comment: 11 pages, 5 figure
Impact of board independence on the quality of community disclosures in annual reports
This study investigates the link between board independence and the quality of community disclosures in annual reports. Using content analysis and a panel dataset from UK FTSE350 companies the results indicate a statistically significant relationship between board independence, as measured by the proportion of nonexecutive directors, and the quality of community disclosures, while holding constant other corporate governance and firm specific variables. The study indicates that companies with more non-executive directors are likely to disclose higher quality information on their community activities than others. This finding offers important insights to policy makers who are interested in achieving optimal board composition and furthers our understanding of the firm’s interaction with its corporate and extended environment through high-quality disclosures. The originality of this paper lies in the fact that it is the first to specifically examine the relationship between outside directors and community disclosures in annual reports. The paper contributes both to the corporate governance and community disclosure literature
Online Stakeholder Interactions in the Early Stage of a Megaproject
The purpose of this paper is to examine the network structure of online stakeholder discussions in the planning stage of a UK public mega project, High Speed Rail. By providing new rail connections between London, Birmingham and Manchester, this project is highly complex as it is embedded in a network of stakeholder relationships that may support or oppose the project. Data drawn from Twitter was analyzed using Social Network Analysis and inductive analysis of user profiles and content. Findings indicate that the majority of online stakeholders oppose the project and form stable clusters. Larger clusters within this network may attempt to deploy power directly in the form of a manipulation strategy while smaller clusters may seek to ally themselves with more powerful groups, a pathway strategy. Overall, the methodology is a useful complement to existing methods and may provide real time insights into the complex, evolving discussions around mega projects
The Sudbury Neutrino Observatory
The Sudbury Neutrino Observatory is a second generation water Cherenkov
detector designed to determine whether the currently observed solar neutrino
deficit is a result of neutrino oscillations. The detector is unique in its use
of D2O as a detection medium, permitting it to make a solar model-independent
test of the neutrino oscillation hypothesis by comparison of the charged- and
neutral-current interaction rates. In this paper the physical properties,
construction, and preliminary operation of the Sudbury Neutrino Observatory are
described. Data and predicted operating parameters are provided whenever
possible.Comment: 58 pages, 12 figures, submitted to Nucl. Inst. Meth. Uses elsart and
epsf style files. For additional information about SNO see
http://www.sno.phy.queensu.ca . This version has some new reference
On the mechanisms governing gas penetration into a tokamak plasma during a massive gas injection
A new 1D radial fluid code, IMAGINE, is used to simulate the penetration of gas into a tokamak plasma during a massive gas injection (MGI). The main result is that the gas is in general strongly braked as it reaches the plasma, due to mechanisms related to charge exchange and (to a smaller extent) recombination. As a result, only a fraction of the gas penetrates into the plasma. Also, a shock wave is created in the gas which propagates away from the plasma, braking and compressing the incoming gas. Simulation results are quantitatively consistent, at least in terms of orders of magnitude, with experimental data for a D 2 MGI into a JET Ohmic plasma. Simulations of MGI into the background plasma surrounding a runaway electron beam show that if the background electron density is too high, the gas may not penetrate, suggesting a possible explanation for the recent results of Reux et al in JET (2015 Nucl. Fusion 55 093013)
Neighboring group participation of the indole nucleus : An unusual DAST-mediated rearrangerment reaction
Copyright 2004 Elsevier Science B.V., Amsterdam. All rights reserved.A rearrangement reaction involving the indole nucleus was investigated using stereochemical markers and low-temperature NMR experiments. Treatment of(3S,4S)-3-hydroxy-4-(2-phenyl-1H-indol-3-yl)-piperidine-1-carboxylic acid benzyl ester (> 90% ee) with diethylaminosulfur trifluoride gave stereospecifically (3S,4S)-4-fluoro-3-(2-phenyl-1H-indol-3-yl)-piperidine-1-carboxylic acid benzyl ester (> 90% ee) with complete regioselectivity. The initial formation of a reactive spirocyclopropyl-3H-indole intermediate is believed to be responsible for the stereo- and regiochemical outcome of the reaction.Peer reviewe
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