Modeling magnetic core loss for sinusoidal waveforms

Thesis (Nav. E.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering; and, (S.M.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 2008.Includes bibliographical references (leaves 90-91).Among the challenging unsolved technical problems that have plagued the minds of scientist and engineers throughout the 20th and 21st century is the development of a quantifiable model to accurately estimate or explain Core Power Losses (CPL). Theoretical advances in magnets led to many model proposals, but as these models where experimentally examined, they quickly lost their validation. Many of the current models use manufacturer's material estimates to form limited curve fitted equations. These equations are only valid for a specific waveform over a specified range. Unless the designers use the same conditions used to determine the manufacturer's fitted equations, the models quickly lose their precision. The scope of this thesis is to explain and compare several of the current models and evaluate them using experiment data. The validity of some of the term component used in many of these models will also be investigated.by Colin J. Dunlop.S.M.Nav.E

The imaging properties of large reflecting astronomical telescopes

This thesis is concerned with some of the limitations concerned with the imaging properties of astronomical telescopes of large apertures. These arise from the atmosphere, the diffracting aperture, the residual errors in the optically worked surfaces and the characteristics of the detection devices. Methods of Fourier optics are used to determine modulation transfer functions and associated point spread function. They are applied to three problems. The first of these is a comparison of the diffraction patterns that are expected from the multi-mirror telescopes. These are made either of separated individual mirrors or of segmented mirrors shaped to an overall parabolic shape. The effect of the dilution of the aperture in the former and the effect of misalignment in the latter is investigated. In the second study, the factors contributing to the imaging of the UK Schmidt telescope are considered and design studies of this and other two variants are examined. In particular the limiting effect of the atmosphere and of the detecting photographic emulsion is noted. Thirdly the overall limitation of the atmospheric seeing is considered experimentally. The Durham Polaris seeing monitor has been designed and built with a shear interferometer. It has been tested at local ground level where local measurements of seeing have been made. In the near future it will be taken and used at La Palma

Alternative and Augmentative Communication Technologies for Supporting Adults With Mild Intellectual Disabilities During Clinical Consultations:Scoping Review

Background: People with intellectual disabilities (IDs) face significant communication barriers when accessing health care services; they find it difficult to identify and describe conditions clearly enough to support practitioners in making an accurate diagnosis. In addition, medical professionals generally have little knowledge and understanding of the needs of people with ID, which may result in the use of consultation techniques that do not cater to their patients' skills. Objective: This review aims to identify and synthesize the literature on alternative and augmentative communication technologies that are used to support adults with mild ID during the exchange of information with medical practitioners. Methods: We performed a scoping review of studies published in English that describe the technologies that are used to promote communication with patients with mild ID during medical consultations. The databases searched were PubMed, ACM Digital Library, and Google Scholar. A qualitative framework-based approach was used to synthesize the data and discern key recurring themes across the identified literature. Results: Of the 1557 articles screened, 15 (0.96%) met our inclusion criteria. The bulk of the communication aids used focused on low-tech solutions, including patient passports, note-based prompts, Talking Mats, health diaries, and easy-read information sheets. Their influence on current practice ranged from advancing medical professionals' knowledge of the health and communication needs of people with ID to increasing interagency collaboration, patient advocacy skills, and health promotion activities. The major barriers to the implementation of low-tech aids were a lack of portability and increased maintenance efforts. Only 3 studies explored the use of mobile apps to promote communication. Their findings indicated that high-tech solutions offer greater customization with regard to the accessibility and health care needs of people with ID. Conclusions: Alternative and augmentative communication technologies have the potential to increase the quality of care provided to patients with mild ID; however, little work has been carried out in this area. Greater emphasis must be placed on (high-tech) two-way communication aids that empower patients to become involved in decisions regarding their care. Quantitative evaluation methods should be used to discern the true benefits of such aids, and researchers should describe their study protocols in depth to promote replication and generalizability

Evaluating the usability of a tablet application to support adults with mild intellectual disabilities during primary care consultations

Patients with mild intellectual disabilities (ID) face significant communication barriers when attending primary care consultations. Yet there is a lack of two-way communication aids available to support them in conveying medical symptoms to General Practitioners (GPs). Based on a multi-stakeholder co-design process including GPs, domain experts, people with mild ID and carers, our previous work developed prototype technology to support people with mild ID in GP consultations. This paper discusses the findings of a usability study performed on the resulting prototype. Five experts in ID/usability, four caregivers, and five GPs participated in cognitive and post-task walkthroughs. They found that the application has the potential to increase communication, reduce time constraints, and overcome diagnostic overshadowing. Nevertheless, the participants also identified accessibility barriers relating to: medical imagery; the abstract nature of certain conditions; the use of adaptive questionnaires; and the overloading of information. Potential solutions to overcome these barriers were also discussed

A SCUBA Scanmap of the HDF: Measuring the bright end of the sub-mm source counts

Using the 850 micron SCUBA camera on the JCMT and a scanning technique different from other sub-mm surveys, we have obtained a 125 square arcminute map centered on the Hubble Deep Field. The one-sigma sensitivity to point sources is roughly 3 mJy and thus our map probes the brighter end of the sub-mm source counts. We find 6 sources with a flux greater than about 12 mJy (>4 sigma) and, after a careful accounting of incompleteness and flux bias, estimate the integrated density of bright sources N(>12 mJy)= 164 (+77/-58) per square degree (68 per cent confidence bounds).Comment: 5 pages, 2 figures, Accepted for publication in MNRA

Impact of robotics-led organisational change on the pharmacy workforce - preliminary findings : report for the pharmacy & prescribing support unit, NHS Greater Glasgow & Clyde

This report looks at the preliminary findings on the impact of robotics-led organisational change on the pharmacy workforc

Experts Views on the Use of Mobile Devices to Support Patients with Mild Learning Disabilities During Clinical Consultations

Due to several factors including time and budget constraints, General Practitioners (GPs) are often under-trained on the communication needs of patients with learning disabilities (LDs). As such, they may find it difficult to extract accurate information from these patients. Digital technologies have the potential to alleviate communication barriers, yet their use in this context remains vastly unexplored. Hence, we conducted 2 focus groups with 12 experts in LDs to investigate how tablet applications may be used to promote the information exchange process between GPs and patients with mild LDs. The experts identified an initial set of design criteria for the future implementation of these technologies and were enthusiastic about the potential impact they may have on primary care. In addition, they also discussed a potential model for extracting medical information from this population, which focused on breaking the overall consultation down into smaller, less cognitively challenging segments

Chromatin structure and evolution in the human genome

<p>Abstract</p> <p>Background</p> <p>Evolutionary rates are not constant across the human genome but genes in close proximity have been shown to experience similar levels of divergence and selection. The higher-order organisation of chromosomes has often been invoked to explain such phenomena but previously there has been insufficient data on chromosome structure to investigate this rigorously. Using the results of a recent genome-wide analysis of open and closed human chromatin structures we have investigated the global association between divergence, selection and chromatin structure for the first time.</p> <p>Results</p> <p>In this study we have shown that, paradoxically, synonymous site divergence (dS) at non-CpG sites is highest in regions of open chromatin, primarily as a result of an increased number of transitions, while the rates of other traditional measures of mutation (intergenic, intronic and ancient repeat divergence as well as SNP density) are highest in closed regions of the genome. Analysis of human-chimpanzee divergence across intron-exon boundaries indicates that although genes in relatively open chromatin generally display little selection at their synonymous sites, those in closed regions show markedly lower divergence at their fourfold degenerate sites than in neighbouring introns and intergenic regions. Exclusion of known Exonic Splice Enhancer hexamers has little affect on the divergence observed at fourfold degenerate sites across chromatin categories; however, we show that closed chromatin is enriched with certain classes of ncRNA genes whose RNA secondary structure may be particularly important.</p> <p>Conclusion</p> <p>We conclude that, overall, non-CpG mutation rates are lowest in open regions of the genome and that regions of the genome with a closed chromatin structure have the highest background mutation rate. This might reflect lower rates of DNA damage or enhanced DNA repair processes in regions of open chromatin. Our results also indicate that dS is a poor measure of mutation rates, particularly when used in closed regions of the genome, as genes in closed regions generally display relatively strong levels of selection at their synonymous sites.</p

Impact of large-scale automation on healthcare staff

New technological advancements are often a driver for change in the redesign of services. More research is needed to better understand the impact of socio-technical dimensions on the implementation of new technological systems in hospital pharmacy. This paper aims to analyse the experiences arising from the large-scale automation of medicines distribution. The introduction of new technology may not only lead to unintended first-order consequences, but can also generate potentially serious adverse feedback loops between the social and technical dimensions. In addition, the longer-term impact of new technology may be quite different for different groups of healthcare staff

Innovation in healthcare systems : a socio-technical perspective

We have investigated the large-scale automation of medicines distribution in NHS Greater Glasgow & Clyde, which is the largest regional health organisation in the UK. The pharmacy service is delivered on 14 hospital sites, involving approximately 530 pharmacy staff and an annual expenditure on medicines of around €138 million.The empirical evidence on the success of technological innovations in healthcare systems is decidedly mixed. There is considerable evidence on both theoretical and empirical grounds that the severity of implementation problems is likely to increase disproportionately with the scale and complexity of a healthcare technology installation. A key finding from the initial stage of our research was that the introduction of new technology in healthcare may not only lead to unintended first-order consequences such as initial staff resistance, but can also generate potentially serious adverse feedback loops between the social and technical dimensions of the new system. A key finding from the second stage of the research is that the longer-term impact of new technology may be quite different for different groups of healthcare staff. New automated systems may free front-stage staff from more routine administrative activities, enabling them to spend more time directly with patients. On the other hand, back-stage staff may well find that their learning opportunities and promotion possibilities are curtailed as a result