A New Method to Improve the Sensitivity of Leak Detection in Self-Contained Fluid-filled Cables

A method of real-time detection of leaks for self-contained fluid-filled cables without taking them out of service has been assessed and a novel machine learning technique, i.e. support vector regression (SVR) analysis has been investigated to improve the detection sensitivity of the self-contained fluid-filled (FF) cable leaks. The condition of a 400 kV underground FF cable route within the National Grid transmission network has been monitored by Drallim pressure, temperature and load current measurement system. These three measured variables are used as parameters to describe the condition of the cable system. In the regression analysis the temperature and load current of the cable circuit are used as independent variables and the pressure within cables is the dependent variable to be predicted. As a supervised learning algorithm, the SVR requires data with known attributes as training samples in the learning process and can be used to identify unknown data or predict future trends. The load current is an independent variable to the fluid-filled system itself. The temperature, namely the tank temperature is determined by both the load current and the weather condition i.e. ambient temperature. The pressure is directly relevant to the temperature and therefore also correlated to the load current. The Gaussian-RBF kernel has been used in this investigation as it has a good performance in general application. The SVR algorithm was trained using 4 days data, as shown in Figure 1, and the optimized SVR is used to predict the pressure using the given load current and temperature information

Technology and benefits of aircraft counter rotation propellers

Results are reported of a NASA sponsored analytical investigation into the merits of advanced counter rotation propellers for Mach 0.80 commercial transport application. Propeller and gearbox performance, acoustics, vibration characteristics, weight, cost and maintenance requirements for a variety of design parameters and special features were considered. Fuel savings in the neighborhood of 8 percent relative to single rotation configurations are feasible through swirl recovery and lighter gearboxes. This is the net gain which includes a 5 percent acoustic treatment weight penalty to offset the broader frequency spectrum noise produced by counter rotation blading

The medicalisation of disabled children and young people in child sexual abuse: impacts on prevention, identification, response and recovery in the United Kingdom

Understandings of disability are situated within social, political and economic circumstances. Internationally, medical conceptualisations of disability prevail, influencing policy and practice, creating a discourse which encourages categorisation, diagnosis and prescribed ways of understanding behaviour. This body of knowledge has a profound influence, providing powerful explanatory models of disability. Such discourse excludes other ways of knowing, with little attention paid to competences and the construction of worlds especially from the perspectives of disabled children themselves. This article draws upon a small number of UK qualitative studies which have examined disabled child abuse and included the experiences of disabled children. These studies have highlighted how medicalised notions of disability have led to both medicalised and psychiatrised responses to abuse, which have ill-served disabled children. It could be argued that medicalisation has led to disabled children being labelled as either ‘too disabled’ to be abused or ‘not disabled enough’ to receive an appropriate response which meets their needs; they are also sometimes regarded as showing signs of mental ill health when such signs are more likely to be an understandable manifestation of the trauma of abuse. Evidence collected indicate that much can be learnt from understanding the construction of disabled childhoods and how our current limited exploration of this affects how society prevents, identifies and responds to disabled child abuse and associated trauma. Drawing upon disabled children’s recommendations to ‘see me, hear me and understand me’, this article will argue that in order to protect disabled children and support them to recover from abuse, we need to move away from a tick-box culture of medicalising, categorising, psychiatrising and ‘othering’ to a greater understanding of disabled children’s worlds, and to a rights-based model of disabled child protection whereby we challenge the increased barriers to support faced by disabled children who have experienced abuse

Art in the Age of Contractual Negotiation

This paper explores the function and purpose of the Artist’s Contrast as a legal document—but not from the perspective of legal enforceability, which is how legal effectiveness is traditionally measured. Rather this paper tells the story of a document that relies upon hallmarks of law (legal language, formality, specificity, and so on) in order to express and attempt to consolidate particular views on artists, artworks, the collectors to whom they sell, and the markets in which they sell. This powerful connection inevitably continues past the moment of sale, and the Artist’s Contract can be read as an attempt to rearrange this connection, to intervene and alter it, to adjust the perspectives of all those participating in it or observing it—all by means of a particular, peculiar legal document. By our account, the goal of the document was to rearrange relationships of creators and buyers of art not just in particular transactions but on a much broader scale: to reshape norms of the marketplace and conceptions of the relevant rights and responsibilities of market participants. It is in the context of these complex social, cultural, and economic webs that the legal document in question can be best understood

The quadrupole moment of slowly rotating fluid balls

In this paper we use the second order formalism of Hartle to study slowly and rigidly rotating stars with focus on the quadrupole moment of the object. The second order field equations for the interior fluid are solved numerically for different classes of possible equations of state and these solutions are then matched to a vacuum solution that includes the general asymptotically flat axisymmetric metric to second order, using the Darmois-Israel procedure. For these solutions we find that the quadrupole moment differs from that of the Kerr metric, as has also been found for some equations of state in other studies. Further we consider the post-Minkowskian limit analytically. In the paper we also illustrate how the relativistic multipole moments can be calculated from a complex gravitational potential.Comment: 13 pages, 5 figure

Existence and topological stability of Fermi points in multilayered graphene

We study the existence and topological stability of Fermi points in a graphene layer and stacks with many layers. We show that the discrete symmetries (spacetime inversion) stabilize the Fermi points in monolayer, bilayer and multilayer graphene with orthorhombic stacking. The bands near $k=0$ and $\epsilon=0$ in multilayers with the Bernal stacking depend on the parity of the number of layers, and Fermi points are unstable when the number of layers is odd. The low energy changes in the electronic structure induced by commensurate perturbations which mix the two Dirac points are also investigated.Comment: 6 pages, 6 figures. Expanded version as will appear in PR

Animal domestication in the era of ancient genomics

The domestication of animals led to a major shift in human subsistence patterns, from a hunter–gatherer to a sedentary agricultural lifestyle, which ultimately resulted in the development of complex societies. Over the past 15,000 years, the phenotype and genotype of multiple animal species, such as dogs, pigs, sheep, goats, cattle and horses, have been substantially altered during their adaptation to the human niche. Recent methodological innovations, such as improved ancient DNA extraction methods and next-generation sequencing, have enabled the sequencing of whole ancient genomes. These genomes have helped reconstruct the process by which animals entered into domestic relationships with humans and were subjected to novel selection pressures. Here, we discuss and update key concepts in animal domestication in light of recent contributions from ancient genomics

How Does a Dipolar Bose-Einstein Condensate Collapse?

We emphasize that the macroscopic collapse of a dipolar Bose-Einstein condensate in a pancake-shaped trap occurs through local density fluctuations, rather than through a global collapse to the trap center. This hypothesis is supported by a recent experiment in a chromium condensate.Comment: Proceedings of 17th International Laser Physics Worksho

Symmetry-based approach to electron-phonon interactions in graphene

We use the symmetries of monolayer graphene to write a set of constraints that must be satisfied by any electron-phonon interaction hamiltonian. The explicit solution as a series expansion in the momenta gives the most general, model-independent couplings between electrons and long wavelength acoustic and optical phonons. As an application, the possibility of describing elastic strains in terms of effective electromagnetic fields is considered in detail, with an emphasis on group theory conditions and the role of time reversal symmetry.Comment: 11 pages, 1 figure. Treatment of ripples in suspended graphene sheets included. Revised journal version with improved presentation and two new appendice