Pull-out forces in shear connectors in composite beams with large web openings

Composite beams with large web openings are often used, and their design is controlled by Vierendeel bending at the four corners of each opening, which is assisted by local composite action with the floor slab. Development of this Vierendeel bending resistance may be limited by pull-out failure of the shear connectors. In this paper, a non-linear elasto-plastic finite element model of a composite beam with web openings was used to investigate this mode of pull-out failure. A test was performed on a typical composite slab in which the shear connectors were subject to pure tension and the failure load was 67 kN, which is approximately 70% of the longitudinal shear resistance. The results of the finite element model are compared against those obtained using the established design theory, that does not limit the vertical pull-out resistance of the shear connectors. It is shown that the local bending resistance due to composite action should be reduced when limited by pull-out of the shear connectors. A parametric study investigated the effect of openings of 600 to 1200 mm length. A simple model is developed to establish the Vierendeel bending resistance, when limited by pull-out of the shear connectors.

The Enemy of My Enemy is My Friend... The Dynamics of Self-Defense Forces in Irregular War: The Case of the Sons of Iraq

This article assesses the effect that leveraging civilian defense force militias has on the dynamics of violence in civil war. We argue that the delegation of security and combat roles to local civilians shifts the primary targets of insurgent violence toward civilians, in an attempt to deter future defections, and re-establish control over the local population. This argument is assessed through an analysis of the Sunni Awakening and ancillary Sons of Iraq paramilitary program. The results suggest that at least in the Al-Anbar province of Iraq, the utilization of the civilian population in counterinsurgent roles had significant implications for the targets of insurgent violence.

Current-induced forces: a simple derivation

We revisit the problem of forces on atoms under current in nanoscale conductors. We derive and discuss the five principal kinds of force under steady-state conditions from a simple standpoint that—with the help of background literature—should be accessible to physics undergraduates. The discussion aims at combining methodology with an emphasis on the underlying physics through examples. We discuss and compare two forces present only under current—the non-conservative electron wind force and a Lorentz-like velocity-dependent force. It is shown that in metallic nanowires both display significant features at the wire surface, making it a candidate for the nucleation of current-driven structural transformations and failure. Finally we discuss the problem of force noise and the limitations of Ehrenfest dynamics

Beyond Attribution: Responsibility of Armed Non-State Actors for Reparations in Northern Ireland, Colombia and Uganda

This chapter explores the responsibility of armed non-state actors for reparations to victims. Traditionally international law has focused on the responsibility of the state, and more recently the responsibility of convicted individuals before the International Criminal Court, to provide reparations for international crimes. Yet despite the prevalence of internal armed conflict over the past few decades, there responsibility of armed groups for reparations has been neglected in international law. Although there is a tentative emerging basis for armed groups to provide reparations under international law, such developments have not yet crystallized into hard law. However, when considering the more substantive practice of states in Northern Ireland, Colombia and Uganda, a greater effort can be discerned in ensuring that such organizations are responsible for reparations. This paper finds that not only can armed non-state actors be held collectively responsible for reparations, but due to the growing number of internal armed conflict they can play an important role in ensuring the effectiveness of reparations in remedying victims’ harm. Yet, finding armed groups responsible for reparations is no panacea for accountability, due to the nature of armed conflicts, responsibility may not be distinct, but overlapping and joint, and such groups may face difficulties in meeting their obligations, thus requiring a holistic approach and subsidiary role for the state.

Land wars in India: Contestations, social forces and evolving neoliberal urban transformation

Land wars in India: Contestations, social forces and evolving neoliberal urban transformation
The recent incidents of ‘land wars’ in India have highlighted the contradictions and challenges of the neoliberal urban transformation through a range of issues across governance, equity and empowerment in the development agenda. Simply put, a strong top down approach and corporate-political nexus have determined the modality of land acquisition, compensation and ultimately the nature of its consumption leaving out majority urban poor from its benefits. The paper focuses on the concept of neoliberalism as a modality of urban governance and emergence of the grassroots activism as a countermagnate to neoliberalist hegemony by examining the inequity and marginalization that embody these ‘land wars’ in India and the forms of resistance from the grassroots - their capacity, relationship and modus operandi. Emerging lessons suggest the potential for advancing governance from the bottoms up leading to more equitable distribution of resources. It is however argued that there is a need for a stronger conception of the ‘grassroots’ in both epistemological and empirical context. In particular, the preconditions for the ‘grassroots organisations’ to foster and play a more effective role requires a more inclusive notion of ‘institutionality and plurality’ within the current political economic context. The empirical focus of the paper is ‘land wars’ observed in Kolkata, West Bengal, however references to other examples across the country have also been made.

Psychological interventions for children and young people affected by armed conflict or political violence: a systematic literature review.

Youths exposed to armed conflict have a higher prevalence of mental health and psychosocial difficulties. Diverse interventions exist that aim to ameliorate the effect of armed conflict on the psychological and psychosocial wellbeing of conflict affected youths. However, the evidence base for the effectiveness of these interventions is limited. Using standard review methodology, this review aims to address the effectiveness of psychological interventions employed among this population. The search was performed across four databases and grey literature. Article quality was assessed using the Downs and Black Quality Checklist (1998). Where possible, studies were subjected to meta-analyses. The remaining studies were included in a narrative synthesis. Eight studies concerned non clinical populations, while nine concerned clinical populations. Review findings conclude that Group Trauma Focused-Cognitive Behavioural Therapy is effective for reducing symptoms of posttraumatic stress disorder, anxiety, depression and improving prosocial behaviour among clinical cohorts. The evidence does not suggest that interventions aimed at non clinical groups within this population are effective. Despite high quality studies, further robust trials are required to strengthen the evidence base, as a lack of replication has resulted in a limited evidence base to inform practice.