Lattice Distortions Around a Tl+ Impurity in NaI:Tl+ and CsI:Tl+ Scintillators. An Ab Initio Study Involving Large Active Clusters

Ab initio Perturbed Ion cluster-in-the-lattice calculations of the impurity centers NaI:Tl+ and CsI:Tl+ are pressented. We study several active clusters of increasing complexity and show that the lattice relaxation around the Tl+ impurity implies the concerted movement of several shells of neighbors. The results also reveal the importance of considering a set of ions that can respond to the geometrical displacements of the inner shells by adapting selfconsistently their wave functions. Comparison with other calculations involving comparatively small active clusters serves to assert the significance of our conclusions. Contact with experiment is made by calculating absorption energies. These are in excellent agreement with the experimental data for the most realistic active clusters considered.Comment: 7 pages plus 6 postscript figures, LaTeX. Submmited to Phys, Rev.

Water-Soluble Mo3S4 Clusters Bearing Hydroxypropyl Diphosphine Ligands: Synthesis, Crystal Structure, Aqueous Speciation, and Kinetics of Substitution Reactions

The [Mo3S4Cl3(dhprpe)3]+ (1+) cluster cation has been prepared by reaction between Mo3S4Cl4(PPh3)3 (solvent)2 and the watersoluble 1,2-bis(bis(hydroxypropyl)phosphino)ethane (dhprpe, L) ligand. The crystal structure of [1]2[Mo6Cl14] has been determined by X-ray diffraction methods and shows the typical incomplete cuboidal structure with a capping and three bridging sulfides. The octahedral coordination around each metal center is completed with a chlorine and two phosphorus atoms of the diphosphine ligand. Depending on the pH, the hydroxo group of the functionalized diphosphine can substitute the chloride ligands and coordinate to the cluster core to give new clusters with tridentate deprotonated dhprpe ligands of formula [Mo3S4(dhprpe-H)3]+ (2+). A detailed study based on stopped-flow, 31P{1H} NMR, and electrospray ionization mass spectrometry techniques has been carried out to understand the behavior of acid−base equilibria and the kinetics of interconversion between the 1+ and the 2+ forms. Both conversion of 1+ to 2+ and its reverse process occur in a single kinetic step, so that reactions proceed at the three metal centers with statistically controlled kinetics. The values of the rate constants under different conditions are used to discuss on the mechanisms of opening and closing of the chelate rings with coordination or dissociation of chloride

Synthesis and Structure of Trinuclear W3S4 Clusters Bearing Aminophosphine Ligands and Their Reactivity toward Halides and Pseudohalides

The aminophosphine ligand (2-aminoethyl)- diphenylphosphine (edpp) has been coordinated to the W3(μ- S)(μ-S)3 cluster unit to afford trimetallic complex [W3S4Br3(edpp)3]+ (1+) in a one-step synthesis process with high yields. Related [W3S4X3(edpp)3]+ clusters (X = F−, Cl−, NCS−; 2+−4+) have been isolated by treating 1+ with the corresponding halide or pseudohalide salt. The structure of complexes 1+ to 4+ contains an incomplete W3S4 cubane-type cluster unit, and only one of the possible isomers is formed: the one with the phosphorus atoms trans to the capping sulfur and the amino groups trans to the bridging sulphurs. The remaining coordination position on each metal is occupied by X. Detailed studies using stopped-flow, 31P{1H} NMR, and ESI-MS have been carried out in order to understand the solution behavior and the kinetics of interconversion among species 1+, 2+, 3+, and 4+ in solution. Density functional theory (DFT) calculations have been also carried out on the reactions of cluster 1+ with the different anions. The whole set of experimental and theoretical data indicate that the actual mechanism of substitutions in these clusters is strongly dependent on the nature of the leaving and entering anions. The interaction between an entering F− and the amino group coordinated to the adjacent metal have also been found to be especially relevant to the kinetics of these reactions

The composition of the protosolar disk and the formation conditions for comets

Conditions in the protosolar nebula have left their mark in the composition of cometary volatiles, thought to be some of the most pristine material in the solar system. Cometary compositions represent the end point of processing that began in the parent molecular cloud core and continued through the collapse of that core to form the protosun and the solar nebula, and finally during the evolution of the solar nebula itself as the cometary bodies were accreting. Disentangling the effects of the various epochs on the final composition of a comet is complicated. But comets are not the only source of information about the solar nebula. Protostellar disks around young stars similar to the protosun provide a way of investigating the evolution of disks similar to the solar nebula while they are in the process of evolving to form their own solar systems. In this way we can learn about the physical and chemical conditions under which comets formed, and about the types of dynamical processing that shaped the solar system we see today. This paper summarizes some recent contributions to our understanding of both cometary volatiles and the composition, structure and evolution of protostellar disks.Comment: To appear in Space Science Reviews. The final publication is available at Springer via http://dx.doi.org/10.1007/s11214-015-0167-

Antisymmetric Magnetic Interactions in Oxo-Bridged Copper(II) Bimetallic Systems

The antisymmetric magnetic interaction is studied using correlated wave-function-based calculations in oxo-bridged copper bimetallic complexes. All of the anisotropic multispin Hamiltonian parameters are extracted using spin-orbit state interaction and effective Hamiltonian theory. It is shown that the methodology is accurate enough to calculate the antisymmetric terms, while the small symmetric anisotropic interactions require more sophisticated calculations. The origin of the antisymmetric anisotropy is analyzed, and the effect of geometrical deformations is addressed.

Business excellence model: an overarching framework for managing and aligning multiple organisational improvement initiatives

Business Excellence Models (BEMs) are used by organisations to assess and improve their work practices and performance. The authors’ research identified that there are currently 94 national Quality/Business Excellence (BE) Awards used in 83 countries. While the use of BEMs is widespread, it was identified that many organisations wanted guidance in terms of which improvement initiatives to implement to assist them on their BE journey. This paper discusses how the BEM can be used as an overarching framework for managing and/or aligning multiple improvement initiatives within the organisation. A new model is developed showing some of the main improvement initiatives that can be adopted towards achieving BE, which are arranged according to the common enabling criteria of BEMs and levels of BE maturity. This proposed model can be used as a pathway/roadmap to BE. In developing this model, a literature review, a document review and several semi-structured interviews were conducted. Sixteen quality and BE experts were interviewed in New Zealand, Singapore, and Malaysia

Heterogeneity of pollen food allergy syndrome in seven Southern European countries: The @IT.2020 multicenter study

Background Pollen food allergy syndrome (PFAS) is a frequently underdiagnosed disease due to diverse triggers, clinical presentations, and test results. This is especially relevant in geographic areas with a broad spectrum of pollen sensitization, such as Southern Europe. Objectives To elucidate similarities and differences of PFAS in nine Southern European centers and identify associated characteristics and unique markers of PFAS. Methods As part of the @IT.2020 Multicenter Study, 815 patients with seasonal allergic rhinitis (SAR), aged 10-60 years, were recruited in seven countries. They completed questionnaires regarding SAR, comorbidities, family history, and PFAS, and underwent skin prick testing (SPT) and serum IgE testing. Results Of the 815 patients, 167 (20.5%) reported PFAS reactions. Most commonly, eliciting foods were kiwi (58, 34.7%), peach (43, 25.7%), and melon (26, 15.6%). Reported reactions were mostly local (216/319, 67.7%), occurring within 5 min of contact with elicitors (209/319, 65.5%). Associated characteristics included positive IgE to at least one panallergen (profilin, PR-10, or nsLTP) (p = 0.007), maternal PFAS (OR: 3.716, p = 0.026), and asthma (OR: 1.752, p = 0.073). Between centers, heterogeneity in prevalence (Marseille: 7.5% vs. Rome: 41.4%, p < 0.001) and of clinical characteristics was apparent. Cypress played a limited role, with only 1/22 SPT mono-sensitized patients reporting a food reaction (p < 0.073). Conclusions PFAS is a frequent comorbidity in Southern European SAR patients. Significant heterogeneity of clinical characteristics in PFAS patients among the centers was observed and may be related to the different pollen sensitization patterns in each geographic area. IgE to panallergen(s), maternal PFAS, and asthma could be PFAS-associated characteristics

Seeking organisational excellence by using the information coming from the EFQM excellence model as starting point: application to a real case

This paper describes how to use the information coming from applying the EFQM excellence model to analyse the perception that the members of an organisation have of it regarding their business vision. Such an analysis is made on the basis of the EFQM excellence model criteria and by applying statistical data analysis techniques. With this study, besides detecting both the strong and weak areas of actuation on which an organisation should focus and act, it is also possible to detect the relationships between the personal characteristics of members of the organisation and their business vision. The main goal is that organisations are able to reach excellence by jointly using an assessment method (the EFQM excellence model) and posterior statistical data analysis techniques (uni-variant and multi-variant). These techniques enable one to complement and enlarge the potential of the EFQM excellence model. Finally, the procedure is illustrated by presenting the main results of applying it to a real case of the Permanent Training Centre of the Polytechnic University of Valencia in Spain. © 2011 Taylor & Francis.Alfaro Saiz, JJ.; Carot Sierra, JM.; Rodríguez Rodríguez, R.; Jabaloyes Vivas, JM. (2011). Seeking organisational excellence by using the information coming from the EFQM excellence model as starting point: application to a real case. Total Quality Management and Business Excellence. 22(8):853-868. doi:10.1080/14783363.2011.597595S853868228Carlos Bou‐Llusar, J., Escrig‐Tena, A. B., Roca‐Puig, V., & Beltrán‐Martín, I. (2005). To what extent do enablers explain results in the EFQM excellence model? International Journal of Quality & Reliability Management, 22(4), 337-353. doi:10.1108/02656710510591192Calvo‐Mora, A., Leal, A., & Roldán, J. L. (2006). Using enablers of the EFQM model to manage institutions of higher education. Quality Assurance in Education, 14(2), 99-122. doi:10.1108/09684880610662006Dale, B. G., Zairi, M., Van der Wiele, A., & Williams, A. R. T. (2000). Quality is dead in Europe – long live excellence ‐ true or false? Measuring Business Excellence, 4(3), 4-10. doi:10.1108/13683040010377737Eskildsen, J. K., Kristensen, K., & Jørn Juhl, H. (2001). The criterion weights of the EFQM excellence model. International Journal of Quality & Reliability Management, 18(8), 783-795. doi:10.1108/eum0000000006033Farrar, M. (2000). Structuring success: A case study in the use of the EFQM Excellence Model in school improvement. Total Quality Management, 11(4-6), 691-696. doi:10.1080/09544120050008084Hides, M. T., Davies, J., & Jackson, S. (2004). Implementation of EFQM excellence model self‐assessment in the UK higher education sector – lessons learned from other sectors. The TQM Magazine, 16(3), 194-201. doi:10.1108/09544780410532936Li, M., & Yang, J. B. (2003). A decision model for self‐assessment of business process based on the EFQM excellence model. International Journal of Quality & Reliability Management, 20(2), 164-188. doi:10.1108/02656710310456608Martín‐Castilla, J. I., & Rodríguez‐Ruiz, Ó. (2008). EFQM model: knowledge governance and competitive advantage. Journal of Intellectual Capital, 9(1), 133-156. doi:10.1108/14691930810845858McAdam, R., & Welsh, W. (2000). A critical review of the business excellence quality model applied to further education colleges. Quality Assurance in Education, 8(3), 120-130. doi:10.1108/09684880010372716Ruiz-Carrillo, J. I. C., & Fernández-Ortiz, R. (2005). Theoretical foundation of the EFQM model: the resource-based view. Total Quality Management & Business Excellence, 16(1), 31-55. doi:10.1080/1478336042000309857Rusjan, B. (2005). Usefulness of the EFQM excellence model: Theoretical explanation of some conceptual and methodological issues. Total Quality Management & Business Excellence, 16(3), 363-380. doi:10.1080/14783360500053972José Tarí, J. (2006). An EFQM model self‐assessment exercise at a Spanish university. Journal of Educational Administration, 44(2), 170-188. doi:10.1108/09578230610652051Wongrassamee, S., Simmons, J. E. L., & Gardiner, P. D. (2003). Performance measurement tools: the Balanced Scorecard and the EFQM Excellence Model. Measuring Business Excellence, 7(1), 14-29. doi:10.1108/13683040310466690Yang, J. B., Dale, B. G., & Siow, C. H. R. (2001). Self-assessment of excellence: An application of the evidential reasoning approach. International Journal of Production Research, 39(16), 3789-3812. doi:10.1080/0020754011006907

Kinetic and DFT Studies on the Mechanism of C−S Bond Formation by Alkyne Addition to the [Mo3S4(H2O)9]4+ Cluster

Reaction of [Mo3(μ3-S)(μ-S)3] clusters with alkynes usually leads to formation of two C−S bonds between the alkyne and two of the bridging sulfides. The resulting compounds contain a bridging alkenedithiolate ligand, and the metal centers appear to play a passive role despite reactions at those sites being well illustrated for this kind of cluster. A detailed study including kinetic measurements and DFT calculations has been carried out to understand the mechanism of reaction of the [Mo3(μ3-S)(μ-S)3(H2O)9]4+ (1) cluster with two different alkynes, 2-butyne-1,4-diol and acetylenedicarboxylic acid. Stoppedflow experiments indicate that the reaction involves the appearance in a single kinetic step of a band at 855 or 875 nm, depending on the alkyne used, a position typical of clusters with two C−S bonds. The effects of the concentrations of the reagents, the acidity, and the reaction medium on the rate of reaction have been analyzed. DFT and TD-DFT calculations provide information on the nature of the product formed, its electronic spectrum and the energy profile for the reaction. The structure of the transition state indicates that the alkyne approaches the cluster in a lateral way and both C−S bonds are formed simultaneously