Observation of nonhexagonal superlattices in high-stage cesium intercalated graphite

Using a scanning transmission electron microscope with an electron beam size of ∼800 Å, we have found that unsaturated cesium intercalated graphite at 98±2 K exhibits multiple structural phases with a typical domain size of ∼1 μm. Electron diffraction patterns from individual structural islands were studied, and the p(2×2), p(3√×2), and p(3√×13−−√) in-plane superlattices were identified

Nonlinear fiber element modeling of RC bridge piers considering inelastic buckling of reinforcement

An advanced modelling technique is developed to model the nonlinear cyclic response of circular RC columns using fibre-based section discretisation method. A comparison between different reinforcing steel models is made. Through a comprehensive parametric study the influence of inelastic buckling of vertical reinforcement on the cyclic response of circular RC columns is investigated. The results have been compared and validated against a set of experimental datasets. The proposed calibrated model accounts for the influence of inelastic buckling of vertical reinforcement and interaction of stiffness of horizontal ties reinforcement with vertical reinforcement. The model also accounts for the fracture of vertical bars due to low-cycle high-amplitude fatigue degradation. Therefore, this model is able to predict the nonlinear cyclic response of circular RC columns up to complete collapse. The results show that the existing uniaxial material models of reinforcing bars that are calibrated using stress-strain behaviour of isolated bars cannot represent the behaviour of reinforcing bars inside RC columns. Moreover, it is found that the buckling length of vertical reinforcement has a significant influence on the pinching response of RC columns and also reduces the low-cycle fatigue life of buckled reinforcemen

Computational Modelling Strategies for Nonlinear Response Prediction of Corroded Circular RC Bridge Piers

A numerical model is presented that enables simulation of the nonlinear flexural response of corroded reinforced concrete (RC) components. The model employs a force-based nonlinear fibre beam-column element. A new phenomenological uniaxial material model for corroded reinforcing steel is used. This model accounts for the impact of corrosion on buckling strength, post-buckling behaviour and low-cycle fatigue degradation of vertical reinforcement under cyclic loading. The basic material model is validated through comparison of simulated and observed response for uncorroded RC columns. The model is used to explore the impact of corrosion on the inelastic response of corroded RC columns

A more representative chamber: representation and the House of Lords

Since 1997 there has been substantive reform of the House of Lords in an effort to make the chamber ‘more democratic and more representative’. Whilst the Labour government failed to press ahead with any of the proposed plans for further reform following the removal of the bulk of the hereditary peers in 1999, it remained committed to the notion that such reform must make the second chamber ‘more representative’. The coalition government's programme advocates a long-term aspiration for a House wholly or mainly elected on the basis of proportional representation, and a short-term approach based on additional appointments to ensure a balance of the parties. What is clear in all of these proposals for reform is a desire for the House of Lords to become more representative than it is at present. However, what is less clear is what is meant by ‘representative’ – who the House of Lords is supposed to represent, and what form representation will take. Moreover, in proposing to make the chamber more representative, either through appointment or election, little attention has been paid to how the current House of Lords provides representation. This article examines these questions in the context of Pitkin's classic conceptions of representation and peers' attitudes towards their own representative rol

Anniversary of a beekeeper’s discovery of thelytoky in Cape honey bees

Significance: The laying workers of the Cape honey bee continue to negatively affect the South African beekeeping industry, with more losses suffered in the northern regions of the country. The reproductive parasites enter susceptible host colonies, activate their ovaries, and lay diploid eggs, leading to colony dwindling and collapse. Diploidy in eggs produced by unmated laying workers arises from thelytokous parthenogenesis, first discovered in honey bees by a hobbyist beekeeper. We examine the consequences of thelytokous parthenogenesis and outline what is being done to understand and limit the spread of the laying workers of the Cape honey bee

Comparison of urine with urethral swabs for the detection of Chlamydia trachomatis in men attending an STD clinic

Urethral swabs and first-catch urine specimens for the detection of Chlamydia trachomatis were collected from 370 black men with urethritis who attended a sexually transmitted disease (STD) clinic in Pretoria. An enzyme immunoassay (EIA) for C. trachomatis was carried out on all urethral swabs and urine specimens. Chlamydial culture and a direct immunofluorescent antibody (DFA) test (Imagen, Dako, UK) were also carried out on urethral swabs; DFA was used for confirmation of urine EIA positives.Based on culture and/or DFA, C. trachomatis was detected in 96 (26%) urethral swab specimens. The sensitivity of urine EIA investigation was 94% and the specificity 99%, compared with those of urethral swab EIA which. were 97% and 99% respectively. The positive and negative predictive values for urine were 96% and 98% compared with 96% and 99% respectively for urethral swabs. Urine examination was therefore sensitive and specific compared with urethral swab examination in these STD patients. In view of this, the advantage of urine as an alternative to urethral swabs for C. trachomatis detection is that sampling is non-invasive and non-traumatic

Flagships and tumbleweed: A history of the politics of gender justice work in Oxfam GB 1986–2015

This article contributes to scholarship on the political nature of feminists’ work in international development NGOs. The case study of Oxfam GB (OGB) is contemporary history, based on compiling a brief history of gender justice work between 1986 and 2014 and 18 months of part-time participant-observation fieldwork during 2014–15. I describe funding pressures and imperatives, contestations of meaning and power struggles within OGB and argue that gender justice becomes entangled in both internal and the external politics of international development. This is part of a wider research programme about how ideas on gender equality norms travel between and around development organizations, so I finally draw conclusions about how norms are contested and embodied. The shapeshifting political nature of feminist work challenges prevailing theories about how norms and ideas travel and take hold within organizations

Nonlinear dynamic analysis and seismic fragility assessment of a corrosion damaged integral bridge

Purpose In this paper the impact of corrosion of reinforcing steel in RC columns on the seismic performance of a multi-span concrete integral bridge is explored. A new constitutive model for corroded reinforcing steel is used. This model simulates the buckling of longitudinal reinforcement under cyclic loading and the impact of corrosion on buckling strength. Cover concrete strength is adjusted to account for corrosion induced damage and core concrete strength and ductility is adjusted to account for corrosion induced damage to transverse reinforcement. This study evaluates the impact which chloride induced corrosion of the reinforced concrete columns on the seismic fragility of the bridge. Fragility curves are developed at a various time intervals over the lifetime. The results of this study show that the bridge fragility increases significantly with corrosion. Design/methodology/approach This paper firstly evaluates the impact which chloride induced corrosion of the columns has on bridge fragility. Finally, fragility curves are developed at various time intervals over the lifetime of the bridge. The results of this study show that the bridge fragility increases significantly with corrosion. Findings 1) It was found that columns dominate the system fragility at all levels of deterioration. Therefore, it highlights the importance of good column design in terms of both seismic detailing and durability for this integral bridge type. 2) In terms of foundation settlement coupled with corrosion, it was found that settlements on the order of the discrete levels adopted for this study increased the system fragility at the slight, moderate and extensive damage states but their impact at the complete damage states is negligible. 3) Ageing considerations are currently neglected in widespread regional risk assessment and loss estimation packages for transport infrastructure. The result of this study provides a methodology that enables bridge managers and owners to employ in seismic risk assessment of existing aging bridges. Originality/value The modelling technician developed in this paper considers the impact of detailed corrosion damaged of RC column on nonlinear dynamic response and fragility of a corroded integral bridge under earthquake loading. The current modelling technique is the most comprehensive 3D fibre element model for seismic analysis and risk assessment of corroded bridges. </jats:sec

The significance of 'the visit' in an English category-B prison: Views from prisoners, prisoners' families and prison staff

A number of claims have been made regarding the importance of prisoners staying in touch with their family through prison visits, firstly from a humanitarian perspective of enabling family members to see each other, but also regarding the impact of maintaining family ties for successful rehabilitation, reintegration into society and reduced re-offending. This growing evidence base has resulted in increased support by the Prison Service for encouraging the family unit to remain intact during a prisoner’s incarceration. Despite its importance however, there has been a distinct lack of research examining the dynamics of families visiting relatives in prison. This paper explores perceptions of the same event – the visit – from the families’, prisoners’ and prison staffs' viewpoints in a category-B local prison in England. Qualitative data was collected with 30 prisoners’ families, 16 prisoners and 14 prison staff, as part of a broader evaluation of the visitors’ centre. The findings suggest that the three parties frame their perspective of visiting very differently. Prisoners’ families often see visits as an emotional minefield fraught with practical difficulties. Prisoners can view the visit as the highlight of their time in prison and often have many complaints about how visits are handled. Finally, prison staff see visits as potential security breaches and a major organisational operation. The paper addresses the current gap in our understanding of the prison visit and has implications for the Prison Service and wider social policy