Temporal evolution of oscillating coronal loops

Context. Transverse oscillations of coronal structures are currently intensively studied to explore the associated magnetohydrodynamic wave physics and perform seismology of the local medium. Aims. We make a first attempt to measure the thermodynamic evolution of a sample of coronal loops that undergo decaying kink oscillations in response to an eruption in the corresponding active region. Methods. Using data from the six coronal wavelengths of SDO/AIA, we performed a differential emission measure (DEM) analysis of 15 coronal loops before, during, and after the eruption and oscillation. Results. We find that the emission measure, temperature, and width of the DEM distribution undergo significant variations on time scales relevant for the study of transverse oscillations. There are no clear collective trends of increases or decreases for the parameters we analysed. The strongest variations of the parameters occur during the initial perturbation of the loops, and the influence of background structures may also account for much of this variation. Conclusions. The DEM analysis of oscillating coronal loops in erupting active regions shows evidence of evolution on time scales important for the study of the oscillations. Further work is needed to separate the various observational and physical mechanisms that may be responsible for the variations in temperature, DEM distribution width, and total emission measure.Comment: Accepted in A&

Study of surfaces and interfaces using quantum chemistry techniques

There are a number of difficulties in elucidating the microscopic details of the electronic states at surfaces and interfaces. The first step should be to determine the structure at the surface or interface, but this is difficult experimentally even for the clean, ordered surface and extremely difficult for cases with impurity atoms (e.g., nonordered oxide layers). The theoretical study of such geometries and energy surfaces is the subject of quantum chemistry. We present a review of some of the theoretical techniques from quantum chemistry that are being applied to surfaces. The procedure consists of treating a finite piece of the surface or interface as a molecule. Ab initio calculations are then carried out on the molecule using the generalized valence bond (GVB) method (with additional configuration interaction), thereby incorporating the dominant many‐body effects. The reliability of these techniques is discussed by giving some examples from molecular chemistry and the surfaces of solids. The strengths and weaknesses of this approach are compared with more traditional band theory related methods and are illustrated with various examples

'Behind Enemy Lines' Menzies, Evatt and Passports for Peking

This article focuses primarily on Australian government responses to the 1952 Peace Conference for Asia and the Pacific Regions. Because the conference was to be held in Peking, it was the subject of immense controversy: Chinese communists were fighting Australian soldiers in Korea and Australian peace activists, most communist or 'fellow travellers', sought to travel behind the 'bamboo curtain'. In this context, the Menzies government's policies on passports were sharply silhouetted. Although this conference has been overlooked in the literature, we can infer from the trajectory of relevant Cold War historiography that Prime Minister Menzies would adopt restrictive, even draconian, policies. This article argues otherwise. It suggests that it was that consistent champion of civil liberties, former deputy prime minister, attorney-general and secretary of the General Assembly of the United Nations and now, in 1952, Leader of the Opposition, Dr Evatt, who favoured more repressive action towards prospective delegates. In contrast, Menzies and his Cabinet were more lenient and shifted towards a harsher policy belatedly and reluctantly. This episode, therefore, challenges some comfortable assumptions about how the early Cold War was fought in Australia

Ab Initio Calculations on the H_(2)+D_(2)=2HD Four‐Center Exchange Reaction. I. Elements of the Reaction Surface

We present the results of ab initio calculations on some interesting regions of the reaction surface for the four‐center exchange reaction H_(2)+D_(2)=2HD. These calculations, which use a minimum basis set of Slater orbitals, indicate that for all geometries appropriate to the transition state of the reaction, a barrier height of at least 148 kcal/mole is present. This is far greater than the energy required to produce free radicals and more than three times the experimental energy of activation, 42 kcal/mole. Considering the sources and magnitudes for errors due to correlation and basis set restrictions, we estimate the barrier height for this exchange reaction to be 132 ± 20 kcal/mole exclusive of zero‐point energies. In this paper we discuss the surface as determined by configuration interaction techniques. We find that the most favorable geometries for the exchange reactions are the square, rhombus, and kite configurations. However, all of these states are unstable with respect to H_(2) + 2H. In addition we find no evidence of collision complexes for any of the likely transition state geometries. In the following paper we will examine the G1 wavefunctions for this system in order to obtain an understanding of the factors responsible for the shape of the surface

Introduction: Trans TV as Intervention into Contemporary Television, Trans TV Dossier 1: Platform Television, Netflix and Industrial Transformations

This dossier is the first of two to emerge out of the Trans TV conference held at the University of Westminster in September 2017. The focus of this specific dossier is in tracking the latest developments and emergent trends affecting contemporary television production, especially as delivered via new online streaming services such as Netflix and Amazon. The article and series of interventions within this dossier set out to challenge both popular and scholarly discourse around these contemporary transformations, pointing not only to technological shifts in television but also to changes in terms of branding, regional and transnational delivery of content, viewing practices, mobile consumption and ‘transfandom’, amongst other factors. The dossier poses the key questions that if television is undergoing a process of transformation as the title 'Trans TV' suggests, what is 'television' becoming and to what extent and in what aspects can we still recognise it as 'television'? While there are a variety of answers to these questions within the dossier, there is a consensus that in the light of these multiple transformations of television, many of the key concepts and assumptions of Television Studies now require thorough reconsideration

The incentive effects of payment by results

Recently the English NHS has introduced an activity-based payment scheme for secondary care - the Payment by Results (PbR) policy. In this paper we discuss, from an economic perspective, the main intended and unintended incentives created by this policy. We also outline the role of different NHS institutions in monitoring and analysing the impact of PbR and consider the information and data requirements for such tasks.

Public services: are composite measures a robust reflection of performance in the public sector?

A composite indicator is an aggregated index comprising individual performance indicators. Composite indicators integrate a large amount of information in a format that is easily understood and are therefore a valuable tool for conveying a summary assessment of performance in priority areas. This research investigates the degree to which composite measures are an appropriate metric for evaluating performance in the public sector. Do they reflect accurately the performance of organisations? To what degree are they influenced by the uncertainty surrounding underlying indicators on which they are based? Are they robust and stable over time? The construction of composite measures creates specific methodological challenges that make such questions especially pertinent. We address these through a series of quantitative analyses of panel data relating to healthcare (Star ratings of NHS acute Trusts) and local government (Comprehensive Performance Assessment (CPA) ratings of authorities) in England where composites have been widely used. The creation of a composite comprises a number of important steps, each of which requires careful judgement. These include the specification of the choice of indicators, the transformation of measured performance on individual indicators, the specification of a set of weights on individual indicators, and combining the indicators using aggregation methods or decision rules. We use Monte Carlo simulations to examine the robustness of performance judgements to these different technical choices. We show the extent to which composites provide stable performance rankings of organisations over time and assess whether variations are due to genuine performance improvement or merely the result of random statistical variation. The analysis suggests that the judgements that have to be made in the construction of the composite can have a significant impact on the resulting score. Technical and analytical issues in the design of composite indicators have important policy implications. We highlight the issues which need to be considered in the construction of robust composite indicators so that they can be designed in ways which will minimise the potential for producing misleading performance information which may fail to deliver the expected improvements or even induce unwanted side-effects.performance measurement, performance indicators, composite indicators

Introduction: Trans TV dossier, III: Trans TV re-evaluated, part 2

This is the second more substantial part of the introduction to the final Trans TV special issue, distributed across issues 15.2 and 15.3 of this journal. As well as introducing the contents of this issue, we reflect in this introduction on the Trans TV project as it has developed since 2017, via an engagement with two key televisual texts namely Transparent (2014–2019) and Pose (2018–). We argue that this certainly reflects positive developments in terms of transgender representation and authorship but this progress is more complex when considered in terms of television aesthetics and politics. We also propose, drawing on the work of Koch-Rein et al (2020), a shift form representation towards the concept of ‘transing’ as a reading strategy, and argue that this has been at the heart of the Trans TV project all along

Streaming intersectionality: Queer and trans television aesthetics in post-medium transformation

Following on from the first Trans TV dossier, this dossier shifts the focus from transformations of television industries, institutions, fans and audiences, to questions of queer and trans* aesthetics and representation on contemporary television. This entails a necessarily intersectional approach, but one that looks at what happens to intersectional genealogies in the era of streaming, Internet-distributed television: do the post-network or even post-medium transformations examined in the first dossier facilitate the opening of queer and trans spaces in the contemporary television landscape? Or is the evolution of television more cyclical than linear, offering both moments of transgression and emergence, as well as reaction, in relation to new technological and institutional configurations. While the focus of most of the work contained within this dossier is on the level of representation and aesthetics, the questions raised are pertinent for understanding the new configurations of technologies, production, distribution and consumption that characterise Internet-distributed television, which in turn need to be seen in relation to the complex intersectional genealogies of televisual content presented here