Mitigation of Fatigue Damage in Self-Healing Vascular Materials

The fatigue response of an epoxy matrix containing vasculature for the delivery of liquid healing agents is investigated. The release of a rapidly curing, two-part epoxy healing chemistry into the wake of a propagating crack reduces the rate of crack extension by shielding the crack tip from the full range of applied stress intensity factor. Crack propagation is studied for a variety of loading conditions, with the maximum applied stress intensity factor ranging from 62 to 84% of the quasi-static fracture toughness of the material. At the highest level of applied load, the rate of mechanical damage is so fast that the healing agents do not fully mix and polymerize, and the effect of healing is minimal. The self-healing response is most effective at impeding the slower propagating cracks, with complete crack arrest occurring at the lowest level of applied load, and reductions of 79–84% in the rate of crack extension at intermediate loads.

Arsenic as a food chain contaminant:mechanisms of plant uptake and metabolism and mitigation strategies

Arsenic (As) is an environmental and food chain contaminant. Excessive accumulation of As, particularly inorganic arsenic (As(i)), in rice (Oryza sativa) poses a potential health risk to populations with high rice consumption. Rice is efficient at As accumulation owing to flooded paddy cultivation that leads to arsenite mobilization, and the inadvertent yet efficient uptake of arsenite through the silicon transport pathway. Iron, phosphorus, sulfur, and silicon interact strongly with As during its route from soil to plants. Plants take up arsenate through the phosphate transporters, and arsenite and undissociated methylated As species through the nodulin 26-like intrinsic (NIP) aquaporin channels. Arsenate is readily reduced to arsenite in planta, which is detoxified by complexation with thiol-rich peptides such as phytochelatins and/or vacuolar sequestration. A range of mitigation methods, from agronomic measures and plant breeding to genetic modification, may be employed to reduce As uptake by food crops.

Climate Change Mitigation and Intergenerational Justice

Existing climate change mitigation policies are particularly concerned with the reconciliation of two seemingly conflicting aims: environmental protection and economic efficiency. The normative principles underlying these policies meanwhile focus on two central ideas: fair burden-sharing and agents' responsibility. However, both existing policy instruments and their supporting philosophical principles are highly problematic in terms of intergenerational justice and truly effective climate change mitigation. Three competing conceptions for allocating and distributing the burdens of climate change mitigation (cap-and-trade schemes, carbon emission taxes, and personal ecological space quotas) and their compatibility with principles of intra- and intergenerational justice are analysed and evaluated. None of the proposed instruments is able to satisfy the demands of effective mitigation and egalitarian justice on its own, which suggests that existing proposals for the distribution of emission rights and climate change-related costs need to be supported by a thicker account of intergenerational justice.

Body shadowing mitigation using differentiated LOS/NLOS channel models for RSSI-based Monte Carlo personnel localization

Research into localization has produced a wealth of algorithms and techniques to estimate the location of wireless network nodes, however the majority of these schemes do not explicitly account for non-line of sight conditions. Disregarding this common situation reduces their accuracy and their potential for exploitation in real world applications. This is a particular problem for personnel tracking where the user's body itself will inherently cause time-varying blocking according to their movements. Using empirical data, this paper demonstrates that, by accounting for non-line of sight conditions and using received signal strength based Monte Carlo localization, meter scale accuracy can be achieved for a wrist-worn personnel tracking tag in a 120 m indoor office environment. © 2012 IEEE.

They’re not racist…’ Prejudice denial, mitigation and suppression in dialogue

Social scientific work on the suppression, mitigation or denial of prejudiced attitudes has tended to focus on the strategic self-presentation and self-monitoring undertaken by individual social actors on their own behalf. In this paper, we argue that existing perspectives might usefully be extended to incorporate three additional considerations. First, that social actors may, on some occasions, act to defend not only themselves, but also others from charges of prejudice. Second, that over the course of any social encounter, interactants may take joint responsibility for policing conversation and for correcting and suppressing the articulation of prejudiced talk. Third, that a focus on the dialogic character of conversation affords an appreciation of the ways in which the status of any particular utterance, action or event as 'racist' or 'prejudiced' may constitute a social accomplishment. Finally, we note the logical corollary of these observations - that in everyday life, the occurrence of 'racist discourse' is likely to represent a collaborative accomplishment, the responsibility for which is shared jointly between the person of the speaker and those other co-present individuals who occasion, reinforce or simply fail to suppress it.

The European Union funded NEOShield project: A global approach to near-Earth object impact threat mitigation

Although discussions are underway within the Action Team 14 of the United Nations COPUOS, there is currently no concerted international plan addressing the impact threat from near-Earth objects (NEOs) and how to organize, prepare and implement mitigation measures. We report on a new international project to address impact hazard mitigation issues, being the subject of a proposal submitted to the European Commission in response to the 2011 FP7 Call "Prevention of impacts from near-Earth objects on our planet". Our consortium consists of 13 research institutes, universities, and industrial partners from 6 countries and includes leading US and Russian space organizations. The primary aim of the project, NEOShield, is to investigate in detail the three most promising mitigation techniques: the kinetic impactor, blast deflection,and the gravity tractor, and devise feasible demonstration missions. Furthermore, we will investigate options for an international strategy for implementation when an actual impact threat arises. The NEOShield project was formally accepted by the European Commission on 17 November 2011 and funded with a total of 5.8 million Euros for a period of 3.5 years. The kick-off meeting took place at the DLR Institute of Planetary Research, Berlin, in January 2012. In this paper we present a brief overview of the planned scope of the project.

NEOShield: An European Project to Address Impact Hazard Mitigation Issues

The European Union NEOShield project is desribed.The primary aim of the project is to investigate in detail the three most promising mitigation techniques: the kinetic impactor, blast deflection, and the gravity tractor, and devise feasible demonstration missions.