572 research outputs found
A Fairer London: The Living Wage in London
This article describes the calculation of London’s first Living Wage, which was set in 2005. It reproduces, in citable form and, for scholarly purposes, the report of the same name produced by the authors for the Greater London Authority.Keywords: Labour Market; Minimum Wage; Living Wage
Modelling the effects of space weather at the Earth’s surface : a UK geoelectric field model
Geomagnetically Induced Currents (GIC), which can flow in technological systems such as power transmission grids, are a consequence of the geoelectric field induced at the surface of the Earth during geomagnetic storms. This poster describes the development of a new 3D 'Thin-Sheet' geoelectric field model which covers the whole of the UK and includes the influence of the surrounding shelf seas. The model can be used to compute the response of the geoelectric field to geomagnetic storms. In conjunction
with a power grid model this enables us to estimate GIC flow in power networks. As an example, we consider the major geomagnetic storm of October 2003. It is envisaged that the model will form one component of a near
real time GIC warning package which is currently being developed by the British Geological Survey (BGS) in conjunction with Scottish Power Plc. The magnetic field associated with the induced geoelectric field is easily calculated. Thus, the electric field model may also be of interest to those studying the effect of internal (induced) geomagnetic field signals on the total measured geomagnetic field
Computational study of the hydrodefluorination of fluoroarenes at [Ru(NHC)(PR<sub>3</sub>)<sub style="vertical-align: sub;">2</sub>(CO)(H)<sub style="vertical-align: sub;">2</sub>]: predicted scope and regioselectivities
Density functional theory calculations have been employed to investigate the scope and selectivity of the hydrodefluorination (HDF) of fluoroarenes, C6F6-nHn (n = 0-5), at catalysts of the type [Ru(NHC)(PR3)(2)(CO)(H)(2)]. Based on our previous study (Angew. Chem., Int. Ed., 2011, 50, 2783) two mechanisms featuring the nucleophilic attack of a hydride ligand at a fluoroarene substrate were considered: (i) a concerted process with Ru-H/C-F exchange occurring in one step; and (ii) a stepwise pathway in which the rate-determining transition state involves formation of HF and a Ru-sigma-fluoroaryl complex. The nature of the metal coordination environment and, in particular, the NHC ligand was found to play an important role in both promoting the HDF reaction and determining the regioselectivity of this process. Thus for the reaction of C6F5H, the full experimental system (NHC = IMes, R = Ph) promotes HDF through (i) more facile initial PR3/fluoroarene substitution and (ii) the ability of the NHC N-aryl substituents to stabilise the key C-F bond breaking transition state through F center dot center dot center dot HC interactions. This latter effect is maximised along the lower energy stepwise pathway when an ortho-H substituent is present and this accounts for the ortho-selectivity seen in the reaction of C6F5H to give 1,2,3,4-C6F4H2. Computed C-F bond dissociation energies (BDEs) for C6F6-nHn substrates show a general increase with larger n and are most sensitive to the number of ortho-F substituents present. However, HDF is always computed to remain significantly exothermic when a silane such as Me3SiH is included as terminal reductant. Computed barriers to HDF also generally increase with greater n, and for the concerted pathway a good correlation between C-F BDE and barrier height is seen. The two mechanisms were found to have complementary regioselectivities. For the concerted pathway the reaction is directed to sites with two ortho-F substituents, as these have the weakest C-F bonds. In contrast, reaction along the stepwise pathway is directed to sites with only one ortho-F substituent, due to difficulties in accommodating ortho-F substituents in the C-F bond cleavage transition state. Calculations predict that 1,2,3,5-C6F4H2 and 1,2,3,4-C6F4H2 are viable candidates for HDF at [Ru(IMes)(PPh3)(2)(CO)(H)(2)] and that this would proceed selectively to give 1,2,4-C6F3H3 and 1,2,3-C6F3H3, respectively.</p
Isomerisation of nido-[C<sub>2</sub>B<sub>10</sub>H<sub>12</sub>]<sup>2−</sup> dianions::Unprecedented rearrangements and new structural motifs in carborane cluster chemistry
We thank the EPSRC for support (DMcK funded by project EP/E02971X/1).Dianionic nido-[C2B10]2- species are key intermediates in the polyhedral expansion from 12- to 13-vertex carboranes and metallacarboranes, and the isomer adopted by these nido intermediates dictates the isomeric form of the 13-vertex product. Upon reduction and metallation of para-carborane up to five MC2B10 metallacarboranes can be produced (Angew. Chem., Int. Ed., 2007, 46, 6706), the structures of which imply the intermediacy of 1,7-, 3,7-, 4,7-, 7,9- and 7,10-isomers of the nido-[C2B10]2- species. In this paper we use density functional theory (DFT) calculations to characterise the reduction of closo-C2B10H12 carboranes and the subsequent isomerisations of the nido-[C2B10H12]2- dianions. Upon reduction para-carborane initially opens to [1,7-nido-C2B10H12]2- (abbreviated to 1,7) and [4,7-nido-C2B10H12]2- (4,7) and isomerisation pathways connecting 1,7 to 7,9, 4,7 to 7,10 and 1,7 to 3,7 have been characterised. For ortho- and meta-carborane the experimental reduction produces 7,9 in both cases and computed pathways for both processes are also defined; with ortho-carborane rearrangement occurs via 7,8, whereas with meta-carborane 7,9 is formed directly. The 7,9 isomer is the global minimum nido-structure. The characterisation of these isomerisation processes uncovers intermediates that adopt new structural motifs that we term basket and inverted nido. Basket intermediates feature a two-vertex basket handle bridging the remaining 10 vertices; inverted nido intermediates are related to known nido species, in that they have 5- and 6-membered belts, but where the latter, rather than the former, is capped, leaving a 5-membered open face. These new intermediates exhibit similar stability to the nido species, which is attributed to their relation to the 13-vertex docosahedron through the removal of 5-connected vertices. Isomerisation pathways starting from nido geometries are most often initiated by destabilisation of the cluster through a DSD process causing the 3-connected C7 vertex to move into a 4-connected site and a neighbouring B vertex to become 3-connected. The ensuing rearrangement of the cluster involves processes such as the pivoting of a 4-vertex diamond about its long diagonal, the pivoting of two 3-vertex triangles about a shared vertex and DSD processes. These processes are all ultimately driven by the preference for carbon to occupy low-connected vertices on the open 6-membered face of the resulting nido species.Publisher PDFPeer reviewe
Developing a ‘Clarity of Mind’: Exploring A Behaviour-Based Approach to Mental Toughness Development in International Youth Football
Mentally tough behaviours (MTbs) entail verbal or physical acts that allow athletes to engage their capacity to produce consistently high performances under pressure. However, researchers of mental toughness (MT) have typically focused on the characteristics that make an athlete mentally tough, rather than how these characteristics are developed through learning to, and reflecting on, the display of MTbs. Consequently, we explored the athlete MT development process within youth international football. Collaborating with a Union of European Football Associations (UEFA) National Association, age-group international players (n = 6), coaches (n = 6), support staff (n = 7), and parents (n = 6) were interviewed regarding MTbs, the specific contexts (e.g., training) that require MTbs, and how key personnel (e.g., coaches, parents, teammates) might help develop players’ MTbs in international youth football. Using thematic analysis, we found MT development to be a relational, multidimensional process, where players transacted with individuals (e.g., coaches) in their environment. These individuals’ behaviours (e.g., autonomy-supportive) influenced players’ propensity to engage in and reflect on contextually relevant MTbs, leading to MT understanding, development, and maintenance. We suggest organisations develop a common understanding of the MT development process and educate all relevant stakeholders regarding their role in supporting athletes to develop the capacity to perform consistently under pressure
Benzo[d][1,2,3]oxadithiole 2-oxide
Funding: A.G. thanks the Commissionerate of College Education, Government of Rajasthan for the generous support of a Foreign Training Program under its Teachers' Interface for Excellence Scheme.A simplified synthesis of the title compound is reported and its 1H and 13C NMR data are fully assigned including determination of H–H and C–H coupling constants. Its X-ray structure has been determined for the first time. NMR data are also presented for the oxygen analogue.Peer reviewe
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