Wear and Friction Modeling on Lifeboat Launch Systems

The RNLI provides search and rescue cover along the UK and RoI coast using a variety of lifeboats and launch techniques. In locations where there is no natural harbour it is necessary to use a slipway to launch the lifeboat into the sea. Lifeboat slipway stations consist of an initial section where the boat is held on rollers followed by an inclined keelway lined with low friction composite materials, the lifeboat is released from the top of the slipway and proceeds under its own weight into the water. The lifeboat is later recovered using a winch line. It is common to manually apply grease to the composite slipway lining before each launch and recovery in order to ensure sufficiently low friction for successful operation. With the introduction of the Tamar class lifeboat it is necessary to upgrade existing boathouses and standardise slipway operational procedures to ensure consistent operation. The higher contact pressures associated with the new lifeboat have led to issues of high friction and wear on the composite slipway linings and the manual application of grease to reduce friction is to be restricted due to environmental impact and cost factors. This paper presents a multidisciplinary approach to modelling slipway panel wear and friction using tribometer testing in conjunction with finite element analysis and slipway condition surveys to incorporate common real-world effects such as panel misalignments. Finally, it is shown that a freshwater lubrication system is effective, reducing cost and environmental impacts while maintaining good friction and wear performance

Motivating a volunteer workforce in the criminal justice system

The Optional Protocol to the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment (OPCAT) requires that police detention processes are monitored and inspected. The United Kingdom is partially ensuring this provision through the use of an existing independent volunteer workforce. This research explores the conditions required for the effective use of this volunteer workforce through 12 semi-structured interviews. An Interpretative Phenomenological Analysis was used that initially generated 46 motivator codes that were clustered into six themes of volunteer motivation consisting of: personal affect, personal growth, social goals, altruistic, activity and values. Ten demotivators were also revealed through the interviews. The implications of these findings for volunteer motivation and how organisations may capitalise on this are discusse

High-Dimensional Diffusive Growth

We consider a model of aggregation, both diffusion-limited and ballistic, based on the Cayley tree. Growth is from the leaves of the tree towards the root, leading to non-trivial screening and branch competition effects. The model exhibits a phase transition between ballistic and diffusion-controlled growth, with non-trivial corrections to cluster size at the critical point. Even in the ballistic regime, cluster scaling is controlled by extremal statistics due to the branching structure of the Cayley tree; it is the extremal nature of the fluctuations that enables us to solve the model.Comment: 5 pages, 3 figures; reference adde

Motivating a volunteer workforce in the criminal justice system

The Optional Protocol to the Convention against Torture and Other Cruel, Inhuman or Degrading Treatment or Punishment (OPCAT) requires that police detention processes are monitored and inspected. The United Kingdom is partially ensuring this provision through the use of an existing independent volunteer workforce. This research explores the conditions required for the effective use of this volunteer workforce through 12 semi-structured interviews. An Interpretative Phenomenological Analysis was used that initially generated 46 motivator codes that were clustered into six themes of volunteer motivation consisting of: personal affect, personal growth, social goals, altruistic, activity and values. Ten demotivators were also revealed through the interviews. The implications of these findings for volunteer motivation and how organisations may capitalise on this are discusse

The role of active galactic nuclei in galaxy formation

We use Monte-Carlo Markov chain techniques to constrain acceptable parameter regions for the Munich L-Galaxies semi-analytic galaxy formation model. Feedback from active galactic nuclei (AGN) is required to limit star-formation in the most massive galaxies. However, we show that the introduction of tidal stripping of dwarf galaxies as they fall into and merge with their host systems can lead to a reduction in the required degree of AGN feedback. In addition, the new model correctly reproduces both the metallicity of large galaxies and the fraction of intracluster light.Comment: Monster's Fiery Breath Conference Proceedings, 4 page

Clock Synchronization based on Second-Order Quantum Coherence of Entangled Photons

We present an algorithm for synchronizing two clocks based on second-order quantum interference between entangled photons generated by parametric down-conversion. The procedure is distinct from the standard Einstein two-way clock synchronization method in that photon correlations are used to define simultaneous events in the frame of reference of a Hong-Ou-Mandel (HOM) interferometer. Once the HOM interferometer is balanced, by use of an adjustable optical delay in one arm, arrival times of simultaneously generated photons are recorded by each clock. Classical information on the arrival times is sent from one clock to the other, and a correlation of arrival times is done to determine the clock offset.Comment: 5 pages, 2 figures. ReVTeX

Rapid Determination of Multiple Reaction Pathways in Molecular Systems: The Soft-Ratcheting Algorithm

We discuss the ``soft-ratcheting'' algorithm which generates targeted stochastic trajectories in molecular systems with scores corresponding to their probabilities. The procedure, which requires no initial pathway guess, is capable of rapidly determining multiple pathways between known states. Monotonic progress toward the target state is not required. The soft-ratcheting algorithm is applied to an all-atom model of alanine dipeptide, whose unbiased trajectories are assumed to follow overdamped Langevin dynamics. All possible pathways on the two-dimensional dihedral surface are determined. The associated probability scores, though not optimally distributed at present, may provide a mechanism for estimating reaction rates