16,952 research outputs found
Omnidirectional antennas transmit and receive over large bandwidth
For exchanging wideband signals between two distant ground stations, low-gain antennas with wide angular coverage and circular polarization are mounted on a single mast extending from a satellite. The transmitting antenna has two decoupled ports or inputs for eliminating switching problems when using two transmitters on different frequencies
A piecewise exponential model for three-dimensional analysis of sandwich panels with arbitrarily graded core
Open Access funded by Engineering and Physical Sciences Research Council Acknowledgements Financial support of this research by the EPSRC (Engineering and Physical Sciences Research Council) (EP/P503299/1, EP/P503930/1), United Kingdom, is gratefully acknowledged.Peer reviewedPublisher PD
Electron diffraction of tilted perovskites
Simulations of electron diffraction patterns for each of the
known perovskite tilt systems have been performed. The
conditions for the appearance of superlattice reflections
arising from rotations of the octahedra are modified to take
into account the effects of different tilt systems for kinematical
diffraction. The use of selected-area electron diffraction as a
tool for perovskite structure determination is reviewed and
examples are included
Integration of Poland into EU global industrial networks: the evidence and the main challenges
In this paper, we attempt to identify the achievements of one decade of transformation of the Polish economy in effecting the integration of its manufacturing sector with those of the broader European and global economy, using the automotive industry as an illustrative example. We begin with a broad picture of the current situation in Poland, looking particularly at the motivations of EU-based investors. We then discuss the automobile industry, again examining the motives of foreign investors and the effects of policy on their behavior. Next, we examine the chief public and private actors in the integration process, with a particular focus on their roles in trying to push Poland's integration in the direction of high value added and high innovation. Finally, we briefly discuss the impact of Poland's accession to the EU on industrial networking, and then summarize our conclusions and suggest a research framework for testing the hypothesis (formulated on the basis of our observations of the Polish case) that the market orientation of a given industry, measured by the ratio of the trade balance in that industry to its total domestic output, depends among other things on ownership structure, with the domestically-owned sector tending to use locally developed technologies and the foreign-owned sector tending to transfer in technology from abroad
Promoting and maintaining health of people with sight loss: A scoping study
This study was undertaken in response to a request by the Thomas Pocklington Trust to identify and explore the following issues: • The needs and concerns regarding immediate risks to health and safety related to sight loss; • Additional risks arising from sight loss for those who are also managing a long term disease; • The difficulties in maintaining and promoting health; • Whether or not health promotion activities and policies sufficiently address perceived needs. Findings pertaining to these objectives have been generated from data collected in Leeds, UK, a city where innovative programming for sight loss has either been planned or is being incorporated into health planning and a review of the literature. Findings related to the last two issues indicate that gaps exist in service provision for maintaining health and emphasise the need for more explicitly targeted health promotion initiatives that could address current weaknesses. - A review of the literature; - Focus group discussions with a range of people who had experienced sight loss; - Interviews with professional practitioners engaged in service provision to this population; - An expert hearing with four professional practitioners, one of whom had sight loss, and two service users with sight loss. Most participants were from the West Yorkshire region and the services described in the study are largely located in Leeds. Evidence from the literature review suggests that people with visual impairment have increased risk of accidents within the home and that ensuing consequences include injuries incurred and decreased confidence. Rates of depression among people who are blind or partially sighted are far higher than in the wider population and the likelihood of depression increases with age, although psycho-social interventions and technological assistance can be successfully implemented to improve quality of life. Sight loss together with other long term health conditions exacerbates the impact of other health conditions and has particularly severe impact on the wellbeing of older people insofar as it may affect their mobility, which in turn increases their risk of falls and depression. The nature and level of support available to people is variable but it is clear that access both to the right information at the right time and to appropriate services is a critical issue. Focus group discussions, interviews and the expert hearing corroborated and extended the themes noted in the literature and discuss the differential impact of different risks to health and the difficulties of coping with these at different times in a person’s life. A simple typology was defined using two dimensions of experience (‘stage of life’ and ‘early/late onset of sight loss’) as a means of organizing findings and providing a means of making further distinctions in interpreting the data. Potentially, this scheme can allow health promotion initiatives to be targeted more effectively to stages at which people with sight loss are more likely to encounter specific difficulties in managing and maintaining their health. There was a clear consensus throughout the study that interventions to meet the needs of people with sight loss must be tailored to meet the specific needs of individuals: people with sight loss are not a homogeneous group and the way in which each person experiences the challenges of sight loss and of managing their health will inevitably vary from person to person. Recommendations generated by this study include: • The scope for more pro-active services and need for closer collaboration between service providers; • The need for provision and promotion of targeted information; • The need for greater awareness of the needs of people with visual impairments among generic service providers; and • Further research that explores the usefulness of the typology with a larger sample more representative of population demographics such as BME communities that are more likely to slip through the cracks of service provision
Transport and Older People: Integrating Transport Planning Tools with User Needs
This study was funded through a pump-priming grant from the Strategic Promotion of Ageing Research Capacity (SPARC) programme. The purpose of the project was to bring together transport and public health research in order to demonstrate how the involvement of older people can help improve tools for transport planning. The study was unique in that it brought together public health and transport planning and engineering with older people to consider how services can be more responsive to older people’s transport needs. The project had five research objectives: 1. To investigate how accessibility problems impact on older people’s independence 2. To determine the extent to which currently available data sources and modelling tools reflect older people’s stated accessibility needs 3. To understand how the gap between expected and perceived accessibility problems varies across different categories of older people 4. To pilot techniques that could be applied to provide a more robust measure of accessibility for older people. 5. To build new research capacity across disciplines to develop a national focus on the interactions between ageing and transport planning. The methods were determined on the basis of ‘appropriate tools with maximum output’. Focus group interviews were selected as a useful tool for reaching a large number of older people within a limited time span, for providing an arena for discussion and debate about a topical subject and for generating ideas for improving transport planning. Following the interviews accompanied walks were undertaken with older people in a range of road environments and traffic situations. The purpose of these walks was to observe and explore the way older people interact with their environment. Data from the focus group interviews and the observations were compared with the outputs from an accessibility planning tool used by local authorities to plan accessible and acceptable transport routes (Accession™). The purpose of this exercise was to investigate whether or not such tools are able to take into account the varying needs of older people. The study was undertaken over eight months. Eighty one older people living in the Leeds district took part in the focus groups. They covered a broad range of mobility levels and used a variety of transport types, as such a reasonably rounded perspective on the issues concerned was offered. In addition six walks were undertaken with older people in their community
The UARS and open data concept and analysis study
Alternative concepts for a common design for the UARS and OPEN Central Data Handling Facility (CDHF) are offered. Costs for alternative implementations of the UARS designs are presented, showing that the system design does not restrict the implementation to a single manufacturer. Processing demands on the alternative UARS CDHF implementations are then discussed. With this information at hand together with estimates for OPEN processing demands, it is shown that any shortfall in system capability for OPEN support can be remedied by either component upgrades or array processing attachments rather than a system redesign. In addition to a common system design, it is shown that there is significant potential for common software design, especially in the areas of data management software and non-user-unique production software. Archiving the CDHF data are discussed. Following that, cost examples for several modes of communications between the CDHF and Remote User Facilities are presented. Technology application is discussed
Mode-locked dysprosium fiber laser: picosecond pulse generation from 2.97 to 3.30 {\mu}m
Mode-locked fiber laser technology to date has been limited to sub-3 {\mu}m
wavelengths, despite significant application-driven demand for compact
picosecond and femtosecond pulse sources at longer wavelengths. Erbium- and
holmium-doped fluoride fiber lasers incorporating a saturable absorber are
emerging as promising pulse sources for 2.7--2.9 {\mu}m, yet it remains a major
challenge to extend this coverage. Here, we propose a new approach using
dysprosium-doped fiber with frequency shifted feedback (FSF). Using a simple
linear cavity with an acousto-optic tunable filter, we generate 33 ps pulses
with up to 2.7 nJ energy and 330 nm tunability from 2.97 to 3.30 {\mu}m
(3000--3400 cm^-1)---the first mode-locked fiber laser to cover this spectral
region and the most broadly tunable pulsed fiber laser to date. Numerical
simulations show excellent agreement with experiments and also offer new
insights into the underlying dynamics of FSF pulse generation. This highlights
the remarkable potential of both dysprosium as a gain material and FSF for
versatile pulse generation, opening new opportunities for mid-IR laser
development and practical applications outside the laboratory.Comment: Accepted for APL Photonics, 22nd August 201
- …