Behavior of Petrie Lines in Certain Edge-Transitive Graphs

We survey the construction and classification of one-, two- and infinitely-ended members of a class of highly symmetric, highly connected infinite graphs. In addition, we pose a conjecture concerning the relationship between the Petrie lines and ends of some infinitely-ended members of this class

Electrical Generation for More-Electric Aircraft Using Solid Oxide Fuel Cells

This report examines the potential for Solid-Oxide Fuel Cells (SOFC) to provide electrical generation on-board commercial aircraft. Unlike a turbine-based auxiliary power unit (APU) a solid oxide fuel cell power unit (SOFCPU) would be more efficient than using the main engine generators to generate electricity and would operate continuously during flight. The focus of this study is on more-electric aircraft which minimize bleed air extraction from the engines and instead use electrical power obtained from generators driven by the main engines to satisfy all major loads. The increased electrical generation increases the potential fuel savings obtainable through more efficient electrical generation using a SOFCPU. However, the weight added to the aircraft by the SOFCPU impacts the main engine fuel consumption which reduces the potential fuel savings. To investigate these relationships the Boeing 787­8 was used as a case study. The potential performance of the SOFCPU was determined by coupling flowsheet modeling using ChemCAD software with a stack performance algorithm. For a given stack operating condition (cell voltage, anode utilization, stack pressure, target cell exit temperature), ChemCAD software was used to determine the cathode air rate to provide stack thermal balance, the heat exchanger duties, the gross power output for a given fuel rate, the parasitic power for the anode recycle blower and net power obtained from (or required by) the compressor/expander. The SOFC is based on the Gen4 Delphi planar SOFC with assumed modifications to tailor it to this application. The size of the stack needed to satisfy the specified condition was assessed using an empirically-based algorithm. The algorithm predicts stack power density based on the pressure, inlet temperature, cell voltage and anode and cathode inlet flows and compositions. The algorithm was developed by enhancing a model for a well-established material set operating at atmospheric pressure to reflect the effect of elevated pressure and to represent the expected enhancement obtained using a promising cell material set which has been tested in button cells but not yet used to produce full-scale stacks. The predictions for the effect of pressure on stack performance were based on literature. As part of this study, additional data were obtained on button cells at elevated pressure to confirm the validity of the predictions. The impact of adding weight to the 787-8 fuel consumption was determined as a function of flight distance using a PianoX model. A conceptual design for a SOFC power system for the Boeing 787 is developed and the weight estimated. The results indicate that the power density of the stacks must increase by at least a factor of 2 to begin saving fuel on the 787 aircraft. However, the conceptual design of the power system may still be useful for other applications which are less weight sensitive

Defining a set of common interprofessional learning competencies for health profession students

Introduction: Increasingly recognized as a core component of contemporary health profession education, interprofessional learning outcomes remain difficult to define and assess across disciplines. The aim of this study was to identify a single set of interprofessional learning competency statements with relevance to all health professions. Methods and results: Six national and international interprofessional competency frameworks were reviewed and combined to give a total of 165 competency statements. Following a process of mapping and grouping these statements into common content areas, duplicate content was removed. In addition, content deemed as a core competency for one or more individual health professions was removed. A round table of experts reviewed the remaining statements and agreed a final set of eight. Each statement was expressed as a specific learning outcome that could be assessed and which described behaviors and practices that students could routinely expect to engage with, and participate in, during the course of their study. Conclusion: Identifying specific interprofessional competencies that students of all health professions require will enable more effective implementation of interprofessional learning activities and assessment within the core curriculum.Maree O'Keefe, Amanda Henderson and Rebecca Chic

Modelling Wind Turbine Wakes at Middelgrunden Wind Farm

This is the author accepted manuscript. The final version is available from the publisher via the URL in this record.As part of the development of an offshore wind farm layout optimisation tool, this paper explores the accuracy and computational time of wake models applied to Middelgrunden Wind Farm outside of Copenhagen, Denmark. In this study, four years of data from 2001 to 2004 are used to test the applicability, accuracy, and computational time of the Jensen, Larsen, Ishihara, and a simplified version of the Ainslie Eddy-Viscosity wake models. This study has shown that the size of the directional sector used in the comparison and if that directional sector is applied to all turbines’ incoming wind velocities or just the northernmost greatly affects the results. From this it is found that the Larsen wake model provides the best balance between accuracy and computational time. It also shows that even a simplified version of a field model takes significantly longer to compute than an analytic model. This study has also shown that using directional sectors of ±15◦ these models perform similarly to previous studies at Nysted and Horns Rev indicating that the close spacing (2.4D) at Middelgrunden is not too close for the use of these models

The effect of nicotine on carrion feeding insects with considerations for use within forensic sciences

The presence of invertebrates on decomposing animal matter has been used extensively by forensic entomologists to estimate time of death for over 100 years. The presence of toxins such as drugs and pesticides on carrion can affect the behaviour and life cycle of such invertebrates. The aim of this thesis was to examine the effects of nicotine upon the colonisation of carrion by invertebrates; nicotine was used because of its historical use as an insecticide and its ubiquitous use in society. The investigations aimed to examine these possible effects both in situ in field-based testing and ex situ in a controlled laboratory environment and to work towards an empirically testable correction factor for the estimation of Postmortem interval estimates in the presence of nicotine. The field-based testing was done using Sus domestica (Linnaeus) carrion with a solution of nicotine injected into the cadaveric throat of the animal. The carrion was protected from feeding and removal by vertebrate scavengers. It was found that nicotine affected the time taken for Diptera to colonise the carrion as well as affecting the behaviour of feeding. Diptera larvae showed avoidance of the nicotine treated throat sites on the carrion, which is the normal site of oviposition. It was determined that the rove beetle Creophilus maxillosus (Linnaeus) was exclusively found on the higher dose nicotine carrion. The rare hoverfly Rhingia rostrata (Linnaeus) was discovered on the control animal; this is the first specimen reported in Nottinghamshire. The investigation also found the first record of the Soldierfly Sargus bipunctatus breeding in carrion; the late breeding period of this species and its significance to the forensic entomologist is considered. The experiments were conducted in the Autumn/Winter months and Spring/Summer months. Nicotine appeared to have a differing effect with the season as the autumnal fauna varied from that of the spring fauna. The presence of nicotine appeared to prevent the animal carcass from drying out, typified by mycophagus beetles in autumn and semi-liquid habitat breeding flies in the summer. The laboratory based investigation examined the effects of nicotine upon the life cycle of Calliphora vomitoria including the effects upon oviposition, rate of development and survivablity. It was found that nicotine significantly affects rate of development of this forensically important fly. This study has shown that a careful study of a single chemical compound and its interaction with carrion and entomology has profound effects upon the alteration of the normal activity of a range of forensically important invertebrates. It will assist in improving the evidential usefulness of entomology to the Forensic Science and Policing communities in criminal investigations

Hydrothermally Emplaced, Lower Mississippian, Tripolitic Chert and Its Possible Relationship to the Tri-State Lead-Zinc Mining District

Across the southern Ozark Region, northern Arkansas, southwestern Missouri, and northeastern Oklahoma, exposures of the Lower Mississippian Boone Formation and its equivalents exhibit well-developed tripolitic chert that has been mined, more or less continuously, for at least 80 years. The tripolitic chert is a replacement of an interval within the basal portion of the upper Boone Formation in Arkansas and Oklahoma, and equivalent to the Elsey Formation in Missouri. The movement of silica-rich, hydrothermal fluids appears to have been much like that of a confined aquifer. It followed the basal upper Boone Formation (Arkansas) = Elsey Formation (Missouri) and was bound below by an impermeable interval at the top of the lower Boone Formation (Arkansas) = Reeds Spring Formation (Missouri), and above by the base of the upper Boone Formation (Arkansas) = Burlington-Keokuk (Missouri). The first hydrothermal event incompletely silicified the basal upper Boone = Elsey Formation. After leaching of the remnant carbonate, thus forming the tripolitic chert, a second hydrothermal event deposited terminated and doubly terminated quartz crystals, and druse in the tripolitic chert voids. This hydrothermal event may have pro-duced the Mississippi Valley-Type (MVT) lead-zinc deposits in northeast Oklahoma and southwestern Missouri. The famous deposits at Picher, Oklahoma, and Joplin, Missouri, appear to be positioned in the apparent path of the hydrothermal fluid migration. While timing of these hydrothermal events is unclear, they may reflect lateral secretion produced by the Ouachita Orogeny in the Late Pennsylvanian

Using non-homogeneous point process statistics to find multi-species event clusters in an implanted semiconductor

The Poisson distribution of event-to-ith-nearest-event radial distances is well known for homogeneous processes that do not depend on location or time. Here we investigate the case of a non-homogeneous point process where the event probability (and hence the neighbour configuration) depends on location within the event space. The particular non-homogeneous scenario of interest to us is ion implantation into a semiconductor for the purposes of studying interactions between the implanted impurities. We calculate the probability of a simple cluster based on nearest neighbour distances, and specialise to a particular two-species cluster of interest for qubit gates. We show that if the two species are implanted at different depths there is a maximum in the cluster probability and an optimum density profile

Optimisation of Offshore Wind Farms Using a Genetic Algorithm

A modular framework for the optimisation of an offshore wind farm using a discrete genetic algorithm is presented. This approach uses a bespoke grid generation algorithm to define the discrete positions that turbines may occupy thereby implicitly satisfying navigational and search and rescue constraints through the wind farm. The presented methodology takes a holistic approach optimising both the turbine placement and inter-array cable network, while minimising the levelised cost of energy and satisfying real world constraints. This tool therefore integrates models for the assessment of the energy production including wake losses; the optimisation of the inter-array cables; and the estimation of costs of the project over the lifetime. This framework will allow alternate approaches to wake and cost modelling as well as optimisation to be benchmarked in the future