Electromechanical systems with transient high power response operating from a resonant AC link

The combination of an inherently robust asynchronous (induction) electrical machine with the rapid control of energy provided by a high frequency resonant AC link enables the efficient management of higher power levels with greater versatility. This could have a variety of applications from launch vehicles to all-electric automobiles. These types of systems utilize a machine which is operated by independent control of both the voltage and frequency. This is made possible by using an indirect field-oriented control method which allows instantaneous torque control in all four operating quadrants. Incorporating the AC link allows the converter in these systems to switch at the zero crossing of every half cycle of the AC waveform. This zero loss switching of the link allows rapid energy variations to be achieved without the usual frequency proportional switching loss. Several field-oriented control systems were developed by LeRC and General Dynamics Space Systems Division under contract to NASA. A description of a single motor, electromechanical actuation system is presented. Then, focus is on a conceptual design for an AC electric vehicle. This design incorporates an induction motor/generator together with a flywheel for peak energy storage. System operation and implications along with the associated circuitry are addressed. Such a system would greatly improve all-electric vehicle ranges over the Federal Urban Driving Cycle (FUD)

Field oriented control of induction motors

Induction motors have always been known for their simple rugged construction, but until lately were not suitable for variable speed or servo drives due to the inherent complexity of the controls. With the advent of field oriented control (FOC), however, the induction motor has become an attractive option for these types of drive systems. An FOC system which utilizes the pulse population modulation method to synthesize the motor drive frequencies is examined. This system allows for a variable voltage to frequency ratio and enables the user to have independent control of both the speed and torque of an induction motor. A second generation of the control boards were developed and tested with the next point of focus being the minimization of the size and complexity of these controls. Many options were considered with the best approach being the use of a digital signal processor (DSP) due to its inherent ability to quickly evaluate control algorithms. The present test results of the system and the status of the optimization process using a DSP are discussed

Keystone XL Pipeline Project: Key Issues

This report describes the Keystone XL pipeline proposal and the process required for federal approval. It summarizes key arguments for and against the pipeline put forth by the pipeline's developers, federal agencies, environmental groups, and other stakeholders

'This isn't what mine looked like': a qualitative study of symptom appraisal and help seeking in people recently diagnosed with melanoma.

OBJECTIVE: To explore symptom appraisal and help-seeking decisions among patients recently diagnosed with melanomas, and to compare experiences of people with 'thinner' (2 mm) melanomas, as thickness at diagnosis is an important prognostic feature. METHODS: In-depth interviews with patients within 10 weeks of melanoma diagnosis explored the factors impacting on their pathways to diagnosis. Framework analysis, underpinned by the Model of Pathways to Treatment, was used to explore the data with particular focus on patients' beliefs and experiences, disease factors, and healthcare professional (HCP) influences. RESULTS: 63 patients were interviewed (29-93 years, 31 women, 30 thicker melanomas). All described their skin changes using rich lay vocabulary. Many included unassuming features such as 'just a little spot' as well as common features of changes in size, colour and shape. There appeared to be subtly different patterns of symptoms: descriptions of vertical growth, bleeding, oozing and itch were features of thicker melanomas irrespective of pathological type. Appraisal was influenced by explanations such as normal life changes, prior beliefs and whether skin changes matched known melanoma descriptions. Most decisions to seek help were triggered by common factors such as advice from family and friends. 11 patients reported previous reassurance about their skin changes by a HCP, with little guidance on monitoring change or when it would be appropriate to re-consult. CONCLUSIONS: Patients diagnosed with both thinner and thicker melanomas often did not initially recognise or interpret their skin changes as warning signs or prompts to seek timely medical attention. The findings provide guidance for melanoma awareness campaigns on more appropriate images, helpful descriptive language and the need to stress the often apparently innocuous nature of potentially serious skin changes. The importance of appropriate advice, monitoring and safety-netting procedures by HCPs for people presenting with skin changes is also highlighted.Thanks to our funding organisation the National Awareness and Early Diagnosis Initiative (NAEDI), and to their funding partners: Cancer Research UK; Department of Health, England; Economic and Social Research Council; Health and Social Care Research and Development Division; Public Health Agency, Northern Ireland, National Institute for Social Care and Health Research, Wales and the Scottish Government. All researchers were independent of the funding body and the study sponsors and funder had no role in study design; data collection, analysis and interpretation of data; in the writing of the report; or decision to submit the article for publication. FW was supported by an NIHR Clinical Lectureship followed by a NIHR Clinician Scientist award at the time of this study. The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health.This is the final published version. It's also available from BMJ Open at http://bmjopen.bmj.com/content/4/7/e005566.abstract

Spatial scales of variance in abundance of intertidal species: effects of region, dispersal mode, and trophic level

Determination of the pattern of variation in population abundance among spatial scales offers much insight into the potential regulating factors. Here we offer a method of quantifying spatial variance on a range of scales derived by sampling of irregularly spaced sites along complex coastlines. We use it to determine whether the nature of spatial variance depends on the trophic level or the mode of dispersal of the species involved and the role of the complexity of the underlying habitat. A least-cost distance model was used to determine distances by sea between all pairs of sites. Ordination of this distance matrix using multidimensional scaling allowed estimation of variance components with hierarchical ANOVA at nested spatial scales using spatial windows. By repeatedly moving these spatial windows and using a second set of spatial scales, average variance scale functions were derived for 50+ species in the UK rocky intertidal. Variance spectra for most species were well described by the inverse power law (1/f?) for noise spectra, with values for the exponent ranging from 0 to 1.1. At higher trophic levels (herbivores and carnivores), those species with planktonic dispersal had significantly higher ? values, indicating greater large- than small-scale variability, as did those on simpler coastlines (southwestern England and Wales vs. western Scotland). Average abundance and proportional incidence of species had the strongest influence on ? values, with those of intermediate abundance and incidence having much greater large-scale variance (? ? 0.5) than rare or ubiquitous species (? ? 0)

Social Use of Facial Expressions in Hylobatids

Abstract Non-human primates use various communicative means in interactions with others. While primate gestures are commonly considered to be intentionally and flexibly used signals, facial expressions are often referred to as inflexible, automatic expressions of affective internal states. To explore whether and how non-human primates use facial expressions in specific communicative interactions, we studied five species of small apes (gibbons) by employing a newly established Facial Action Coding System for hylobatid species (Gibbon-FACS). We found that, despite individuals often being in close proximity to each other, in social (as opposed to non-social contexts) the duration of facial expressions was significantly longer when gibbons were facing another individual compared to non-facing situations. Social contexts included grooming, agonistic interactions and play, whereas nonsocial contexts included resting and self-grooming. Additionally, gibbons used facial expressions while facing another individual more often in social contexts than non-social contexts where facial expressions were produced regardless of the attentional state of the partner. Also, facial expressions were more likely 'responded to' by the partner's facial expressions when facing another individual than non-facing. Taken together, our results indicate that gibbons use their facial expressions differentially depending on the social context and are able to use them in a directed way in communicative interactions with other conspecifics

Effects of a museum-based social-prescription intervention on quantitative measures of psychological wellbeing in older adults

Aims: To assess psychological wellbeing in a novel social prescription intervention for older adults called Museums on Prescription, and to explore the extent of change over time in six self-rated emotions (‘absorbed, ‘active’, ‘cheerful’, ‘encouraged’, ‘enlightened’ and ‘inspired’). Methods: Participants (n=115) aged 65-94 were referred to museum-based programmes comprising 10, weekly sessions, by healthcare and third sector organisations using inclusion criteria (e.g. socially isolated; able to give informed consent; not in employment; not regularly attending social or cultural activities) and exclusion criteria (e.g. unable to travel to the museum; unable to function in a group situation; unlikely to be able to attend all sessions; unable to take part in interviews and complete questionnaires). In a within-participants design, the Museum Wellbeing Measure for Older Adults (MWM-OA) was administered pre-post session at start- mid- and end-programme. Twelve programmes, facilitated by museum staff and volunteers, were conducted in seven museums in central London and across Kent. In addition to the quantitative measures, participants, carers where present, museum staff and researchers kept weekly diaries following guideline questions, and took part in end programme in-depth interviews. Results: Multivariate analyses of variance showed significant participant improvements in all six MWM-OA emotions, pre-post session at start- mid- and end-programme. Two emotions, ‘absorbed’ and ‘enlightened’, increased pre-post session disproportionately to the others; ‘cheerful’ attained the highest pre-post session scores whereas ‘active’ was consistently lowest. Conclusions: Museums can be instrumental in offering museum-based programmes for older adults to improve psychological wellbeing over time. Participants in the study experienced a sense of privilege, valued the opportunity to liaise with curators, visit parts of the museum closed to the public, and handle objects normally behind glass. Participants appreciated opportunities afforded by creative and co-productive activities to acquire learning and skills, and get to know new people in a different context