Day-night asymmetries of low-energy electrons in Saturn's inner magnetosphere

We examine the day-night asymmetry of near-equatorial low energy (12-100 eV) electron fluxes measured by Cassini from July 1, 2004 through April 1, 2010. This energy range is also known to be associated with interchange injections. The electrons are separated into field-aligned (0 degrees to 20 degrees and 160 degrees to 180 degrees) pitch angles and trapped (70 degrees to 110 degrees) pitch angles. There is a stronger day-night asymmetry for the trapped than the field-aligned electrons, but both show enhanced energy fluxes on the nightside relative to the dayside. The dayside electron fluxes decrease sharply at an L-shell of 8, while the nightside electrons exhibit a slow decline in to L = 5. Our finding, along with previous research of high energy electrons, shows that this asymmetry is energy independent. This suggests that interchange injections are stronger, and therefore penetrate deeper into the magnetosphere, on the nightside

CFD analyses for advanced pump design

As one of the activities of the NASA/MSFC Pump Stage Technology Team, the present effort was focused on using CFD in the design and analysis of high performance rocket engine pumps. Under this effort, a three-dimensional Navier-Stokes code was used for various inducer and impeller flow field calculations. An existing algebraic grid generation procedure was-extended to allow for nonzero blade thickness, splitter blades, and hub/shroud cavities upstream or downstream of the (main) blades. This resulted in a fast, robust inducer/impeller geometry/grid generation package. Problems associated with running a compressible flow code to simulate an incompressible flow were resolved; related aspects of the numerical algorithm (viz., the matrix preconditioning, the artificial dissipation, and the treatment of low Mach number flows) were addressed. As shown by the calculations performed under the present effort, the resulting code, in conjunction with the grid generation package, is an effective tool for the rapid solution of three-dimensional viscous inducer and impeller flows

A combined Eulerian-Lagrangian two-phase analysis of the SSME HPOTP nozzle plug trajectories

As a result of high cycle fatigue, hydrogen embrittlement, and extended engine use, it was observed in testing that the trailing edge on the first stage nozzle plug in the High Pressure Oxygen Turbopump (HPOTP) could detach. The objective was to predict the trajectories followed by particles exiting the turbine. Experiments had shown that the heat exchanger soils, which lie downstream of the turbine, would be ruptured by particles traveling in the order of 360 ft/sec. An axisymmetric solution of the flow was obtained from the work of Lin et. al., who used INS3D to obtain the solution. The particle trajectories were obtained using the method of de Jong et. al., which employs Lagrangian tracking of the particle through the Eulerian flow field. The collision parameters were obtained from experiments conducted by Rocketdyne using problem specific alloys, speeds, and projectile geometries. A complete 3-D analysis using the most likely collision parameters shows maximum particle velocities of 200 ft/sec. in the heat exchanger region. Subsequent to this analysis, an engine level test was conducted in which seven particles passed through the turbine but no damage was observed on the heat exchanger coils

Super-resolution provided by the arbitrarily strong superlinearity of the blackbody radiation

Blackbody radiation is a fundamental phenomenon in nature, and its explanation by Planck marks a cornerstone in the history of Physics. In this theoretical work, we show that the spectral radiance given by Planck's law is strongly superlinear with temperature, with an arbitrarily large local exponent for decreasing wavelengths. From that scaling analysis, we propose a new concept of super-resolved detection and imaging: if a focused beam of energy is scanned over an object that absorbs and linearly converts that energy into heat, a highly nonlinear thermal radiation response is generated, and its point spread function can be made arbitrarily smaller than the excitation beam focus. Based on a few practical scenarios, we propose to extend the notion of super-resolution beyond its current niche in microscopy to various kinds of excitation beams, a wide range of spatial scales, and a broader diversity of target objects

Protocol study: Sexual and reproductive health knowledge, information-seeking behaviour and attitudes among Saudi women: A questionnaire survey of university students

Copyright © 2014 Farih et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.Background - Sexual and reproductive health (SRH), a basic right for women worldwide, is infrequently researched in countries in the Middle East and North Africa (MENA). No empirical studies of SRH among Saudi women exist. This protocol describes a study to explore the SRH knowledge, information-seeking behaviour and attitudes of Saudi female university students. Methods/Design - This study will administer a questionnaire survey to female students at 13 universities in Riyadh, Saudi Arabia. The questionnaire was developed following a literature search to identify relevant content, with psychometrically tested tools used when available. The content layout and the wording and order of the questions were designed to minimize the risk of bias. The questionnaire has been translated into Arabic and piloted in preparation for administration to the study sample. Ethical approval for the study has been granted (reference no. QMREC2012/54). After questionnaire administration, the data will be collated, analysed and reported anonymously. The findings will be published in compliance with reporting guidelines for survey research. Discussion - This study will be the first to provide fundamental information concerning Saudi females university students SRH knowledge and information needs.King Abdullah Scholarship Program, Saudi Arabi

Fibre optic sensing of ageing railway infrastructure enhanced with statistical shape analysis

Funder: Aston UniversityAbstract: Developing early-warning sensor-based maintenance systems for ageing railway infrastructure, such as masonry arch bridges, can be a challenging task due to the difficulty of identifying degradation/damage as the source of small, gradual changes in sensor data, as opposed to other environmental and loading effects. This paper offers a new method of applying statistical modelling and machine learning to enhance the interpretation of fibre optic sensing data, and, therefore, improve deterioration monitoring of railway infrastructure. Dynamic strain and temperature monitoring data between 2016 and 2019 from a fibre Bragg grating (FBG) network installed in a Victorian railway viaduct are first presented. The statistical shape analysis adopted in this study is modified to track changes in the shape of FBG signals directly linked to train speed and dynamic strain amplitudes. The method is complemented by a support vector machine, which is trained to identify different classes of trains. After distinguishing train types, dynamic strain was found to be clearly correlated to temperature, verifying previous findings. No correlation with train speed was observed. The integrated system is then able to compensate for changes in the structural performance due to variations in train loading and ambient temperature, and identify changes in dynamic deformation caused by degradation, in an order comparable to the signal noise (± 2 micro-strain). As a result, the new procedure is shown to be capable of detecting small magnitudes of local degradation well before this degradation manifests itself in typical global measures of response

Schema Acquisition from One Example: Psychological Evidence for Explanation-Based Learning

Coordinated Science Laboratory was formerly known as Control Systems LaboratoryOffice of Naval Research / N00014-86-K-0309University of Illinois Cognitive Science/AI fellowship

An exploratory cluster randomised trial of a university halls of residence based social norms marketing campaign to reduce alcohol consumption among 1st year students

<p>Aims: This exploratory trial examines the feasibility of implementing a social norms marketing campaign to reduce student drinking in universities in Wales, and evaluating it using cluster randomised trial methodology.</p> <p>Methods: Fifty residence halls in 4 universities in Wales were randomly assigned to intervention or control arms. Web and paper surveys were distributed to students within these halls (n = 3800), assessing exposure/contamination, recall of and evaluative responses to intervention messages, perceived drinking norms and personal drinking behaviour. Measures included the Drinking Norms Rating Form, the Daily Drinking Questionnaire and AUDIT-C.</p> <p>Results: A response rate of 15% (n = 554) was achieved, varying substantially between sites. Intervention posters were seen by 80% and 43% of students in intervention and control halls respectively, with most remaining materials seen by a minority in both groups. Intervention messages were rated as credible and relevant by little more than half of students, though fewer felt they would influence their behaviour, with lighter drinkers more likely to perceive messages as credible. No differences in perceived norms were observed between intervention and control groups. Students reporting having seen intervention materials reported lower descriptive and injunctive norms than those who did not.</p> <p>Conclusions: Attention is needed to enhancing exposure, credibility and perceived relevance of intervention messages, particularly among heavier drinkers, before definitive evaluation can be recommended. A definitive evaluation would need to consider how it would achieve sufficient response rates, whilst hall-level cluster randomisation appears subject to a significant degree of contamination.</p&gt

Exploring the relation between preoperative physical functioning and the impact of major complications in patients following pancreatic resection

BACKGROUND: This study aimed to evaluate the association between preoperative level of physical functioning and time to recovery of physical functioning, postoperative complications, and the impact of postoperative major complications in patients undergoing elective pancreatic resection. Additionally, prediction models to identify high-risk patients for developing a major complication were externally validated. METHODS: Perioperative data of patients who underwent pancreatic resection were analysed. Primary outcomes were time to recovery of physical functioning and postoperative major complications. Impact of a major complication was explored by evaluating its effect on time to recovery of physical functioning. Risk-prediction models were retrieved following a systematic review. RESULTS: Multivariable analysis (n = 63) showed that ASA grade III (OR 3.498) and preoperative platelet count (OR 1.005) were associated with major complications, whereas aerobic capacity (OR 0.347) was associated with time to recovery of physical functioning. Age, preoperative aerobic capacity, functional mobility, and perceived level of functional capacity were associated with the impact of a major complication. The AUC of two risk prediction models were 0.556 and 0.701. CONCLUSION: Preoperative parameters of physical function were associated with postoperative outcomes and may be useful in outcome prediction, although future approaches should not only register the incidence of major complications but also take the impact of a complication on a patient's physical functioning into account