Wilton Park

Abstract Virtual Reality (VR) is increasingly recognised as a transformative tool for safety training, particularly in high-risk fields such as construction and electrical engineering. However, to successfully integrate this technology within established training practices, training outcomes ought to be rigorously validated. By investigating the effects of eXtended Reality (XR) technology upon the delivery of safety training for high-voltage operations, this paper proposes guidelines by which instructor adoption of XR tools may be assessed and seeks to establish a methodology to measure the effectiveness of training delivery. Factors influencing instructor adoption of XR tools and methods by which staff may be prepared to integrate new training methods are discussed. An exploration of relevant performance metrics, including trainee immersion and operational accuracy, informs the design of an experiment to compare the outcomes of different training sequences: participants are allocated into four experimental groups: (1) traditional training only, (2) VR training only, (3) traditional training followed by VR, and (4) VR training followed by traditional training. Immersive Tendencies Questionnaires (ITQs) assess trainee predispositions to immersion and Presence Questionnaires (PQs) assess perceived presence within the VTE. As well as detailing the collection of data, the experiment desgin also proposes statistical analyses to determine whether VR training complements traditional methods, enhances participant confidence, and improves knowledge retention.

Despite notable scientific and medical advances, broader political, socioeconomic and behavioural factors continue to undercut the response to the COVID-19 pandemic1,2. Here we convened, as part of this Delphi study, a diverse, multidisciplinary panel of 386 academic, health, non-governmental organization, government and other experts in COVID-19 response from 112 countries and territories to recommend specific actions to end this persistent global threat to public health. The panel developed a set of 41 consensus statements and 57 recommendations to governments, health systems, industry and other key stakeholders across six domains: communication; health systems; vaccination; prevention; treatment and care; and inequities. In the wake of nearly three years of fragmented global and national responses, it is instructive to note that three of the highest-ranked recommendations call for the adoption of whole-of-society and whole-of-government approaches1, while maintaining proven prevention measures using a vaccines-plus approach2 that employs a range of public health and financial support measures to complement vaccination. Other recommendations with at least 99% combined agreement advise governments and other stakeholders to improve communication, rebuild public trust and engage communities3 in the management of pandemic responses. The findings of the study, which have been further endorsed by 184 organizations globally, include points of unanimous agreement, as well as six recommendations with >5% disagreement, that provide health and social policy actions to address inadequacies in the pandemic response and help to bring this public health threat to an end.

Solution precursor thermal spray can become a breakthrough technology for the deposition of coatings with novel chemistries; however, the understanding of the process that the feedstock material undergoes is still lacking when compared to more traditional presentations (i.e. powder and suspension). In this paper, niobium-doped TiO2 coatings were deposited by solution precursor high velocity oxy-fuel thermal spraying, studying its microstructure and phase. It was reported that a lower flame temperature produced a highly porous coating, while the porosity was reduced at higher flame temperature. Investigation of the phase content showed that, contrary to our current understanding, a higher flame power implied an increase of the anatase phase content for solution precursor spray. Three methods were used: Rietveld refinement, peak height and peak area of the x-ray diffraction patterns. Additionally, single splats were analysed, showing that as the precursor travels through the flame, pyrolysis and sintering takes place to form the solid material. These results were used to derive a model of the physico-chemical transformation of the solution precursor. This work proves that solution precursor thermal spray is a promising technique for the deposition of doped ceramic coatings, being the microstructure and phase content controllable through the spraying parameters.

Recent years have seen increasing interest in incorporating resampling methods into introductory statistics courses and the high school mathematics curriculum. While the use of permutation tests for data from experiments is a step forward, the use of simple bootstrap methods for sampling situations is more problematical. This article demonstrates via counterexamples that many of the claims made for these simple methods are simply wrong. Their use with beginners can only be justified after their true properties have been fully researched, and their many limitations explained to students. Supplementary materials for this article are available online.

ABSTRACTThree commercial bis‐benzoxazine monomers based on the aniline derivatives of bisphenol A (BA‐a), bisphenol F (BF‐a), and 3,3′‐thiodiphenol (BT‐a) are examined using a variety of spectroscopic, chromatographic, and thermomechanical techniques. The kinetics of the polymerization of BA‐a were found to be well described using an autocatalytic model for which values of n = 1.39 and m = 2.49 were obtained for the early and later stages of reaction respectively (activation energy = 81–88 kJ/mol.). Following recrystallization the same monomer yielded values of n = 1.80, m = 0.92, and Ea = 94–97 kJ/mol. BF‐a and BT‐a were also found to be well described using an autocatalytic model for which values of n = m = 2.11 (BF‐a) and n = 2.10, m = 1.47 (BT‐a) were obtained for the early and later stages of reaction (activation energy = 80–84 kJ/mol. for BF‐a and 88–95 kJ/mol. for BT‐a). The kinetic data are compared with parallel studies involving chemically initiated benzoxazine monomers. Molecular simulation is used to examine the rotational freedom of the central bridging units and this is related to the degree of conversion achieved. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 2068–2081

A series of blends is prepared comprising 2,2-bis(3,4-dihydro-3-phenyl-2H-1,3-benzoxazine)propane (BA-a) with variously 5, 10, or 20 wt % of a selected oligomer represented by poly(arylsulfone) (PSU) or poly(arylethersulfone) (PES). The oligomers, comprising either chloro-, hydroxyl- or benzoxazinyl- (Bz) terminal functionality, are of low molecular weight (3000–12000 g mol–1). The introduction of the oligomers is shown to initiate the polymerization of a bisbenzoxazine monomer where the terminal functionality of the oligomer is coreactive (e.g., hydroxyl or benzoxazine) without having a detrimental effect on the polymerization kinetics (similar values for the activation energy and orders of reaction are obtained). The introduction of the nonreactive chloro-terminated oligomer appears to favor the formation of an interpenetrating network (IPN) with a higher energy of activation. The thermal stability of the blends is generally increased compared with the polybenzoxazine homopolymer, regardless of the molecular weight or thermoplastic loading. Aside from the aforementioned PSUCl-containing IPN, the nature of the resulting network is slightly modified by the addition of the thermoplastic with similar or slightly elevated cross-link densities recorded (compared with the polybenzoxazine homopolymer). The heterogeneity of the network increases with a broadening of the tan δ response, suggesting an improvement in the toughness of the resulting blend.

Three bis-benzoxazine monomers basedon the aniline derivatives of bisphenol A (BA-a), bisphenol F (BF-a),and 3,3′-thiodiphenol (BT-a) are examined using a variety ofspectroscopic, chromatographic, and thermomechanical techniques. Theeffect on the polymerization of the monomers is compared using twocommon compounds, 3,3′-thiodiphenol (TDP) and 3,3′-thiodipropionicacid (TDA), at a variety of loadings. It is found that the diacidhas a greater effect on reducing the onset of polymerization and increasingcross-link density and Tg for a givenbenzoxazine. However, the addition of >5 wt % of the diacid hada detrimental effect on the cross-link density, Tg, and thermal stability of the polymer. The kineticsof the polymerization of BA-a were found to be well described usingan autocatalytic model for which values of n = 1.64and m = 2.31 were obtained for the early and laterstages of reaction (activation energy = 81 kJ/mol). Following recrystallizationthe same monomer yielded values n = 1.89, m = 0.89, and Ea = 94 kJ/mol(confirming the influence of higher oligomers on reactivity). Thechoice of additive (in particular the magnitude of its pKa) appears to influence the nature of the network formationfrom a linear toward a more clusterlike growth mechanism.