Conditioning of a metal surface in a high-voltage system is the progressive development of resistance to vacuum arcing over the operational life of the system. This is relevant for accelerator cavities, where high level of performance is only achievable after a long conditioning period. Beyond the accelerator research field, this is an important topic for any technology where breakdowns can cause device failure, either by directly disrupting device operation or by causing cumulative hardware damage.

We are developing a direct method to measure the surface resistivity of a metal surface that is being conditioned with a HV DC system by inducing a high frequency (GHz) radio-frequency current in the parallel-plate electrode system. If the system can function as a resonant cavity, the surface resistivity data would be encoded in its quality factor (Q-factor). The changes in the resistivity measured in cryogenic conditions would indicate a formation of dislocations under the surface, something that has been speculated as an important process behind the conditioning.

In this paper, we present two modified designs of the electrode system, which will act as a resonant cavity, the results of 3D EM simulations and experimental results regarding the characterization of this resonant system.

Since at least the colonial era, the Central African Republic (CAR) has been a hotbed of rural rebellion and protest. This article explores the political discourses of members of the Anti-Balaka, a diffuse protest movement and armed rebellion, comparing discourses to see how they vary in relation to demographic categories: urban and rural, elites and peasants. Lombard and Vlavonou find that rural peasants demand a moral economy of interpersonal respect, while elite (usually urban) adherents claim inclusion in a system of official recognition and patronage. Both are concerned with respect, but what is radical about the vision of the peasants is that they can enact it on their own.

We examine cultural and ideological barriers to gender equality in a young democracy, Indonesia, where women’s political representation has increased slowly since democratization, but where survey results point to declining support for women’s political leadership. In both country and comparative literature, the effect of ideological factors—including religion—on voter support for women candidates is contested. Using results of a nationally representative survey, we group respondents according to a “political patriarchy” index. We find that being a Muslim is a strong predictor of holding patriarchal attitudes; university education is associated with gender-egalitarian views. Patriarchal views, in turn, are associated with opposition to increasing Indonesia’s gender quota and with lower levels of self-reported voting for female candidates. Our findings suggest that patriarchal attitudes drive both policy preferences and voter behavior. We conclude that Indonesia’s recent conservative Islamic turn likely underpins widespread—and increasing—opposition to gender equality in politics.

We prove existence and unicity of slope-stable vector bundles on a general polarized hyperkähler (HK) variety of type $K3^{[n]}$ with certain discrete invariants, provided the rank and the first two Chern classes of the vector bundle satisfy certain equalities. The latter hypotheses at first glance appear to be quite restrictive, but, in fact, we might have listed almost all slope-stable rigid projectively hyperholomorphic vector bundles on polarized HK varieties of type $K3^{[n]}$ with $20$ moduli.

Let $\{b_n\}_{n=1}^{\infty }$ be a sequence of integers larger than 1. We will study the harmonic analysis of the equal-weighted Moran measures $\mu _{\{b_n\},\{{\mathcal D}_n\}}$ with ${\mathcal D}_n=\{0,1,2,\ldots ,q_n-1\}$, where $q_n$ divides $b_n$ for all $n\geq 1.$ In this paper, we first characterize all the maximal orthogonal sets of $L^2(\mu _{\{b_n\},\{{\mathcal D}_n\}})$ via a tree mapping. By this characterization, we give some sufficient conditions for the maximal orthogonal set to be an orthonormal basis.

In England, Bangladeshi men are amongst the lowest number of people referred to primary care NHS Talking Therapies services and amongst the most likely to have deteriorated (NHS Digital, 2020). Factors related to culture, religion and gender influence stigma and help-seeking (Robinson et al., 2011). Furthermore, a lack of knowledge from services and professionals on cultural understandings of mental distress facilitate a failure to fully understand the needs of individual populations (Faheem, 2023). The aim of this research study was to qualitatively explore stigma and help-seeking for mental health difficulties, within British-Bangladeshi Muslim men in London. Recruitment consisted of men aged 22–59 years, experiencing symptoms of anxiety and/or depression but not accessing formal support. Ethical approval was obtained from Royal Holloway, University of London. After an online screening questionnaire, individual semi-structured video interviews were completed between May and October 2020. Reflexive thematic analysis presented six over-arching themes: ‘different understanding of mental health’, ‘traditional cultural expectations’, ‘fear and loss’, ‘coping resources’, ‘barriers to access’ and ‘community outreach and collaboration’. Many factors were highlighted as barriers accessing support, such as stigma and trust in services. Key practice implications are highlighted for services and practitioners. Professionals must understand the factors which impact the wellbeing of Bangladeshi men, how to better meet the needs of the community, and remove barriers to help. Participants also suggested initiatives to raise mental health awareness and reduce stigma, as an inclusive approach is needed with greater listening to communities and partnerships with local authorities.

We prove that, given a finitely generated subgroup H of a free group F, the following questions are decidable: is H closed (dense) in F for the pro-(met)abelian topology? Is the closure of H in F for the pro-(met)abelian topology finitely generated? We show also that if the latter question has a positive answer, then we can effectively construct a basis for the closure, and the closure has decidable membership problem in any case. Moreover, it is decidable whether H is closed for the pro-$\mathbf {V}$ topology when $\mathbf {V}$ is an equational pseudovariety of finite groups, such as the pseudovariety $\mathbf {S}_k$ of all finite solvable groups with derived length $\leq k$. We also connect the pro-abelian topology with the topologies defined by abelian groups of bounded exponent.

Currently, most wheel-legged robots need to complete the switching of the wheel-and-leg modal in a stationary state, and the existing algorithms of statically switching the wheel-leg modal cannot meet the control requirements of multimodal switching dynamically for robots. In this paper, to achieve efficient switching of the wheel-and-leg modal for a quadruped robot, the novel transformable mechanism is designed. Then, a multimodal coordination operation control framework based on multiple algorithms is presented, incorporating the minimum foot force distribution method (algorithm No.1), the minimum joint torque distribution method (algorithm No.2), and the method of combining the single rigid body dynamic model with quadratic programming (algorithm No.3). In the process of switching wheel-leg modal dynamically, the existing algorithm No.3 is prone to produce the wrong optimal force due to the change of the whole-body rotational inertia. Therefore, an improved algorithm No.1 and algorithm No.2 are proposed, which do not consider the change in the body’s inertia. The control effects of the three algorithms are compared and analyzed by simulation. The results show that algorithm No.3 can maintain a small error in attitude angle and speed tracking regardless of whether the robot is under multilegged support or omnidirectional walking compared to the other two algorithms. However, proposed algorithms No.1 and No.2 can more accurately track the target speed when the robot is walking with wheels raising and falling. Finally, a multi-algorithm combination control scheme formulated based on the above control effects has been demonstrated to be effective for the dynamic switching of the wheel-and-leg modal.

The present study aimed to increase understanding of how singing activities may be initiated in primary school, and what support and assistance teachers require to conduct singing activities as an integrated part of the school day. Five music teachers participated in a focus group interview. The following main themes were identified: 1) pedagogical and methodological flexibility, 2) the role of routines and familiarity, 3) the embodied and multimodal dimensions of singing, 4) the importance of accompaniment and instruments, 5) the experience of insecurity and obstacles and 6) the perceived synergies between singing and other learning activities. This knowledge may be important to integrate within music teacher education in order to secure singing’s place in schools.

The Chinese Communist Party has been increasing its control over village elections since the early 2010s, yet this move has not triggered any widespread popular resistance. Drawing on ethnographic evidence from village elections held in 2017 in a county in Hunan province, I conceptualize a form of electoral manipulation I term “consensus elections,” in which the Party engineers a pre-electoral consensus with ordinary villagers on whom to select while deterring challenges from village elites. Consensus elections are rooted in the Chinese political elites’ ideal that favours electoral participation over competition. While participation increases regime legitimacy, competition threatens regime authority. Propaganda promoting this electoral ideal shapes the views of ordinary villagers, laying a basis of legitimacy on consensus elections. The villagers embraced voting as being oriented by a unitary common interest and developed a cynicism whereby campaigning was equated with corruption. Comparison of the processes involved in engineering consensus elections in five villages suggests popular support for such elections. Whereas popular resistance was mounted against the lack of participation, popular complicity helps the Party to deter challenges from village elites. Consensus elections have facilitated the fall of Chinese village elections without undermining the Party's legitimacy, but consensus elections will also encourage more political challenges from village elites through non-institutionalized channels.

In this article I analyze stories about the negotiation of European racialization ideologies in the Society Islands (Tahiti and its Islands) in the late eighteenth century. My focus is the disjunctures between European understandings of their encounters at Tahiti, and what Pacific scholars have come to understand of Polynesian understandings of themselves and various foreigners in that early period. In doing so, I draw out the ways sexuality and gender mediated, enabled, and were also constituted through such racialization processes in their cultural and historical specificity. A key point of departure for this analysis is that the embodiment of race is a negotiated social process. The comparative historical case study I offer up here follows current scholarly moves in seeking out the insights to be gained by tracking racialization as a contingent process, as open rather than closed, as variegated rather than singular, and as imperfectly and only tenuously wrought through ideologies that may be profoundly unanticipated from the vantage point of modernist logics of essentialism and foundationalism. The resulting analysis aims to create space for critically revisiting the ways in which racial normativities and racialized embodiment operate, and how they work, and fail to work, to promote naturalized racist hierarchies of privilege and subordination.

For societies transitioning from conflict to peace, the phenomenon of child soldiers poses significant challenges. These include quandaries associated with assisting in the reintegration of serving child soldiers, determining how to prevent future recruitment of child soldiers, and pursuing accountability of those who utilize child soldiers. In addition, questions are also raised as to whether and how child soldiers responsible for crimes committed during conflict are to be held to account. While no one mechanism or response can adequately and sufficiently address the multifaceted issues that arise, peace agreements, as foundational documents that serve as the blueprint for peacebuilding and the post-conflict State, can make a useful contribution to some or all of them. Drawing on all references to child soldiers in 77 peace agreements signed between 1990 and 2022, this article examines the ways in which peace agreements address the issue of child soldiers.