Dielectric constant predictions for energetic materials using quantum calculations

The dielectric constant (DC) is one of the key properties for detection of threat materials such as Improvised Explosive Devices (IEDs). In the present paper, the density functional theory (DFT) as well as ab-initio approaches are used to explore effective methods to predict dielectric constants of a series of 12 energetic materials (EMs) for which experimental data needed to experimentally determine the dielectric constant (refractive indices) are available. These include military grades energetic materials, nitro and peroxide compounds, and the widely used nitroglycerin. Ab-initio and DFT calculations are conducted. In order to calculate dielectric constant values of materials, potential DFT functional combined with basis sets are considered for testing. Accuracy of the calculations are compared to experimental data listed in the scientific literature, and time required for calculations are both evaluated and discussed. The best functional/basis set combinations among those tested are CAM-B3LYP and AUG-cc-pVDZm, which provide great results, with accuracy deviations below 5% when calculated results are compared to experimental data.     

A periodic maintenance model with used equipment and random minimal repair

The maintenance strategy considered in this article is in the class of block replacement policies. The working unit is replaced by new ones at instants T,2T,3T,… independently of the age and state of the unit. If a failure occurs between these instants, the random repair cost is evaluated. If it is smaller than a predetermined control limit then a minimal repair is carried out. Otherwise the unit is replaced by a used unit. The performance of this maintenance strategy is evaluated in terms of average total cost per time unit over an infinite time span. The mathematical model is defined and several analytical results are obtained. A computer program has been written, which solves the mathematical problem, and some examples are given for the cases where the underlying life distribution is gamma, Weibull or truncated normal.     

Dynamic evacuation routes for personnel on a naval ship

We propose a dynamic escape route system for emergency evacuation of a naval ship. The system employs signals that adapt to the causative contingency and the crew's physical distribution about the ship. A mixed‐integer nonlinear programming model, with underlying network structure, optimizes the evacuation process. The network's nodes represent compartments, closures (e.g., doors and hatches) and intersections, while arcs represent various types of passageways. The objective function integrates two potentially conflicting factors: average evacuation time and the watertight and airtight integrity of the ship after evacuation. A heuristic solves the model approximately using a sequence of mixed‐integer linear approximating problems. Using data for a Spanish frigate, with standard static routes specified by the ship's designers, computational tests show that the dynamic system can reduce average evacuation times, nearly 23%, and can improve a combined measure of ship integrity by up to 50%. In addition, plausible design changes to the frigate yield further, substantial improvements. Published 2008 Wiley Periodicals, Inc. Naval Research Logistics 2008     

Between vigilantism and ethnocultural preservation: An investigation into the legitimacy of the non-state policing activities of the Ombatse group among the Eggon people of Nassarawa State,Nigeria

Postmodern contradictions in postcolonial Nigeria have led to the fetishisation of alternative local security measures often labelled as vigilante activities. The profiling of these groups as ethnic militia often undermines their essential bid to provide security while delimiting security needs to the physical. The fallouts of such profiling are frictions between federal security agents and ethnic-based security groups, often resulting in violence, as exemplified by the 7 May 2013 incident between the Nigerian federal security agents and the Ombatse. This study focuses on the emergence and activities of the Ombatse as an alternative security apparatus of the Eggon. It presents three years of field research which entailed the use of ethnography, key informant interviews and observation. The findings reveal that the Ombatse emerged to assert historical legitimacy for both the physical and spiritual securitisation of the Eggon through a return to the ancestral ways of social engineering. The study considers the security challenges in Nigeria, and also situates the Eggon historical context within political, religious, sociocultural and economic intersections of securitisation. It concludes that the Ombatse situates its legitimacy within the Eggon past and retains its relevance through the holistic focus of providing both physical and spiritual security.     

THE REAL STORY BEHIND THE MAKING OF THE FRENCH HYDROGEN BOMB

Based on the first-person account of coauthor Pierre Billaud, a prominent French participant, this article describes for the first time in such detail the history of the development of the French hydrogen bomb in the 1960s and the organization of military nuclear research in France. The authors illustrate the extent to which French defense and governmental authorities did not support research on thermonuclear weapons until 1966. Billaud, a project insider, relates the historical episodes that led to France's successful 1968 thermonuclear test, including the names of the individuals involved and how a timely tip from a foreign source hastened the success of the first H-bomb test.     

Peace as an international public good: An application to Southern Africa

This paper reviews the basic economic concepts relevant to international public goods production and applies them to the case of security and peace in southern Africa. To this end, it extracts from the literature a set of fundamental features that help determine the likelihood of success of any collective action and applies these features to the current southern African context.     

Justice empowered or justice hampered: The International Criminal Court in Darfur

It came as a surprise to many international observers when, on 31 March 2005, the United Nations Security Council passed resolution 1593, which referred the situation in Darfur to the jurisdiction of the International Criminal Court. Some celebrated this event as initiating a new era in which international criminal justice would prevail, but they might have done well to consider the objections immediately raised by the representatives of the Sudanese government, which was not a party to the ICC, a point that created a series of impediments to the implementation of the resolution. For all that the ICC has been charged with investigating crimes against humanity in Darfur, its investigators are being prevented from seeking the evidence on the ground essential to any successful prosecution. The Sudanese government has so far maintained its obstructive position, arguing that it is capable of handling such cases within its own sovereign jurisdiction. The imperative of excluding the ICC from Darfur has contributed to Khartoum's objections to the deployment of a UN force to replace the African Union mission there. In sum: the challenges faced by the ICC in Darfur demonstrate that international criminal justice does not operate in a political vacuum.     

Why Culture Matters: Revisiting the Sino-Indian Border War of 1962

This article examines the nuclear command and control (C²) system implemented in Pakistan since 1998, and discusses its potential consequences for the risk of inadvertent or unauthorised use of nuclear weapons. I argue that troubled civil-military relations and Pakistan's doctrine of ‘asymmetric escalation’ account for the creation of a command and control system with different characteristics during peacetime and military crises. Although the key characteristics of Pakistan's nuclear C² system allow relatively safe nuclear operations during peacetime, operational deployment of nuclear weapons during military standoffs is likely to include only rudimentary protections against inadvertent or unauthorised nuclear release. The implication of this study is that any shift from peacetime to wartime command and control procedures is likely to further destabilise Indo-Pakistani relations during the early stages of a diplomatic or military standoff, and introduce a non-trivial risk of accidental escalation to the nuclear level.