4 resultados para theoretical investigation


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Background
There is a growing impetus across the research, policy and practice communities for children and young people to participate in decisions that affect their lives. Furthermore, there is a dearth of general instruments that measure children and young people’s views on their participation in decision making. This paper presents the reliability and validity of the Child and Adolescent Participation in Decision Making Questionnaire (CAP-DMQ) and specifically looks at a population of looked-after children where a lack of participation in decision making is an acute issue.
Methods
The participants were 151 looked after children and adolescents between 10-23 years of age who completed the 10 item CAP-DMQ. Of the participants 113 were in receipt of an advocacy service that had an aim of increasing participation in decision-making with the remaining participants not having received this service.
Results
The results showed that the CAP-DMQ had good reliability (Cronbach’s alpha = .94) and showed promising uni-dimensional construct validity through an exploratory factor analysis. The items in the CAP-DMQ also demonstrated good content validity by overlapping with prominent models of child and adolescent participation (Lundy 2007) and decision making (Halpern 2014). A regression analysis showed that age and gender were not significant predictors of CAP-DMQ scores but receipt of advocacy was a significant predictor of scores (effect size d=.88), thus showing appropriate discriminant criterion validity.
Conclusion
Overall, the CAP-DMQ showed good reliability and validity. Therefore, the measure has excellent promise for theoretical investigation in the area of child and adolescent participation in decision making and equally shows empirical promise for use as a measure in evaluating services which have increasing the participation of children and adolescents in decision making as an intended outcome.

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Extremely broad emission wings at Hβ and Hα have been found in VLT-FLAMES Tarantula Survey data for five very luminous BA supergiants in or near 30 Doradus in the Large Magellanic Cloud. The profiles of both lines are extremely asymmetrical, which we have found to be caused by very broad diffuse interstellar bands (DIBs) in the longward wing of Hβ and the shortward wing of Hα. These DIBs are well known to interstellar but not to many stellar specialists, so that the asymmetries may be mistaken for intrinsic features. The broad emission wings are generally ascribed to electron scattering, although we note difficulties for that interpretation in some objects. Such profiles are known in some Galactic hyper/supergiants and are also seen in both active and quiescent Luminous Blue Variables (LBVs). No prior or current LBV activity is known in these 30 Dor stars, although a generic relationship to LBVs is not excluded; subject to further observational and theoretical investigation, it is possible that these very luminous supergiants are approaching the LBV stage for the first time. Their locations in the HRD and presumed evolutionary tracks are consistent with that possibility. The available evidence for spectroscopic variations of these objects is reviewed, while recent photometric monitoring does not reveal variability. A search for circumstellar nebulae has been conducted, with an indeterminate result for one of them.

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A selected ion flow tube study of the reactions of a series of gas-phase atomic cations (S+, Xe+, O+, Kr+, N+, Ar+ and Ne+) and molecular ions (SF n+ (n = 1-5), CFn+ (n = 1-3), CF2Cl+, H3O+, NO+, N 2O+, CO2+, CO+, and N2+) spanning a large range of recombination energies (6.3-21.6 eV), with acetone, 1,1,1-trifluoroacetone, and hexafluoroacetone has been undertaken with the objective of exploring the nature of the reaction ion chemistry as the methyl groups in acetone are substituted for CF3. The reaction rate coefficients and product ion branching ratios for all 66 reactions, measured at 298 K, are reported. The experimental reaction rate coefficients are compared to theoretically calculated collisional values. Several distinct reaction processes were observed among the large number of reactions studied, including charge transfer (non-dissociative and dissociative), abstraction, ion-molecule associations and, in the case of the reactions involving the reagent ion H3O+, proton transfer. 

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Graphene with heteroatom doping has found increasing applications in a broad range of catalytic reactions. However, the doping effects accounting for the enhanced catalytic activity still remain elusive. In this work, taking the triiodide electroreduction reaction as an example, we study systematically the intrinsic activity of graphene and explore the origin of doping-induced activity variation using first-principles calculations, in which two typical N and S dopants are tested. The most common graphene structures, basal plane, armchair edge, and zigzag edge, are considered, and it is found that the former two structures show a weak adsorption ability for the iodine atom (the key intermediate in the triiodide electroreduction reaction), corresponding to a low catalytic activity. Doping either N or S can strengthen the adsorption and thus increase the activity, and the codoping of N and S (NS-G) exhibits a synergistic effect. A detailed investigation into the whole process of the triiodide electroreduction reaction at the CH3CN/NS-G interface is also carried out to verify these activity trends. It is found that the zigzag edges which contain spin electrons show a relatively stronger adsorption strength compared with the basal plane and armchair edge, and initial doping would result in the spin disappearance that evidently weakens the adsorption; with the disappearance of spin, however, further doping can increase the adsorption again, suggesting that the spin electrons may play a preliminary role in affecting the intrinsic activity of graphene. We also analyzed extensively the origin of doping-induced adsorption enhancement of graphene in the absence of spin; it can be rationalized from the electronic and geometric factors. Specifically, N doping can result in a more delocalized “electron-donating area” to enhance I adsorption, while S doping provides a localized structural distortion, which activates the nearest sp2-C into coordinatively unsaturated sp3-C. These results explain well the improved activity of the doping and the synergistic effect of the codoping. The understandings are generalized to provide insight into the enhanced activity of the oxygen reduction reaction on heteroatom doped graphene. This work may be of importance toward the design of high-activity graphene based material.