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Institution

University of Bath

EducationBath, Bath and North East Somerset, United Kingdom
About: University of Bath is a education organization based out in Bath, Bath and North East Somerset, United Kingdom. It is known for research contribution in the topics: Population & Photonic-crystal fiber. The organization has 15830 authors who have published 39608 publications receiving 1358769 citations. The organization is also known as: Bath University.


Papers
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Journal ArticleDOI
16 Nov 2007-Science
TL;DR: Generation and guidance of a three-octave spectral comb, spanning wavelengths from 325 to 2300 nanometers, in a hydrogen-filled hollow-core photonic crystal fiber, is demonstrated, opening up a robust and much simplified route to synthesizing attosecond pulses.
Abstract: Ultrabroad coherent comb-like optical spectra spanning several octaves are a chief ingredient in the emerging field of attoscience. We demonstrate generation and guidance of a three-octave spectral comb, spanning wavelengths from 325 to 2300 nanometers, in a hydrogen-filled hollow-core photonic crystal fiber. The waveguidance results not from a photonic band gap but from the inhibited coupling between the core and cladding modes. The spectrum consists of up to 45 high-order Stokes and anti-Stokes lines and is generated by driving the confined gas with a single, moderately powerful (10-kilowatt) infrared laser, producing 12-nanosecond-duration pulses. This represents a reduction by six orders of magnitude in the required laser powers over previous equivalent techniques and opens up a robust and much simplified route to synthesizing attosecond pulses.

505 citations

Journal ArticleDOI
TL;DR: The current study proposes the potential of the pharmaceuticals carbamazepine, naproxen, diclofenac and ibuprofen to be regarded as priority ECs for environmental monitoring due to their regular detection and persistence in environmental waters and their possible contribution towards adverse health effects in humans and wildlife.

505 citations

Journal ArticleDOI
24 Mar 2005-Nature
TL;DR: All-fibre gas cells based on gas-filled hollow-core photonic crystal fibres are reported, which exhibit high performance, excellent long-term pressure stability and ease of use, and could permit gas-phase laser devices incorporated in a ‘credit card’ or even in a laser pointer.
Abstract: Gas-phase materials are used in a variety of laser-based applications--for example, in high-precision frequency measurement, quantum optics and nonlinear optics Their full potential has however not been realized because of the lack of a suitable technology for creating gas cells that can guide light over long lengths in a single transverse mode while still offering a high level of integration in a practical and compact set-up or device As a result, solid-phase materials are still often favoured, even when their performance compares unfavourably with gas-phase systems Here we report the development of all-fibre gas cells that meet these challenges Our structures are based on gas-filled hollow-core photonic crystal fibres, in which we have recently demonstrated substantially enhanced stimulated Raman scattering, and which exhibit high performance, excellent long-term pressure stability and ease of use To illustrate the practical potential of these structures, we report two different devices: a hydrogen-filled cell for efficient generation of rotational Raman scattering using only quasi-continuous-wave laser pulses; and acetylene-filled cells, which we use for absolute frequency-locking of diode lasers with very high signal-to-noise ratios The stable performance of these compact gas-phase devices could permit, for example, gas-phase laser devices incorporated in a 'credit card' or even in a laser pointer

505 citations

Journal ArticleDOI
TL;DR: In this article, sustainable procurement in the UK public sector is investigated using a questionnaire that draws on established scales for "purchasing social responsibility" and 106 responses were received from procurement officers.
Abstract: Purpose – This study aims to investigate sustainable procurement in the UK public sector.Design/methodology/approach – Sustainable procurement is investigated using a questionnaire that draws on established scales for “purchasing social responsibility”. The survey was administered across the UK public sector, and 106 responses were received from procurement officers.Findings – Analysis of quantitative and qualitative survey data reveal there is significant variation across public sector agencies in the nature of sustainable procurement practice. Local authorities have a particularly strong emphasis on buying from local and small suppliers relative to other sectors, health looks generally lower in many categories, and education appears to have something of an emphasis on environmental aspects of sustainable procurement. Cost has been found to be the leading barrier to sustainable procurement, and top management support the leading facilitator.Research limitations/implications – There is likely to be select...

504 citations

Journal ArticleDOI
02 Nov 2006-Nature
TL;DR: The results indicate that ‘silver-bullet’ conservation strategies alone will not deliver efficient conservation solutions, and priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa.
Abstract: 'Silver bullet' conservation strategies assume that the distribution of extinction-prone species in one well studied taxonomic group will predict the distribution of comparable species in other groups. This has been hard to test, but the availability of new databases on the global distribution of birds, mammals and amphibians means that a test is now possible. The three groups show similar patterns in terms of overall species richness, but the distribution of threatened and rare species is different in each group. Silver bullet strategies alone, it seems, miss the target. Instead, priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa. 'Silver-bullet' approaches to conservation assume that conservation strategy can be based on the distribution of species in one or two well known taxonomic groups, as there is high cross-taxon congruence in large-scale patterns of biodiversity. Although birds, mammals and amphibians show similar patterns in terms of overall species richness, the distribution of threatened and rare species is found to be different in each group. Global conservation strategies commonly assume that different taxonomic groups show congruent geographical patterns of diversity, and that the distribution of extinction-prone species in one group can therefore act as a surrogate for vulnerable species in other groups when conservation decisions are being made1,2,3,4. The validity of these assumptions remains unclear, however, because previous tests have been limited in both geographical and taxonomic extent5,6,7,8,9,10,11,12. Here we use a database on the global distribution of 19,349 living bird, mammal and amphibian species to show that, although the distribution of overall species richness is very similar among these groups, congruence in the distribution of rare and threatened species is markedly lower. Congruence is especially low among the very rarest species. Cross-taxon congruence is also highly scale dependent, being particularly low at the finer spatial resolutions relevant to real protected areas. ‘Hotspots’ of rarity and threat are therefore largely non-overlapping across groups, as are areas chosen to maximize species complementarity. Overall, our results indicate that ‘silver-bullet’ conservation strategies alone will not deliver efficient conservation solutions. Instead, priority areas for biodiversity conservation must be based on high-resolution data from multiple taxa.

504 citations


Authors

Showing all 16056 results

NameH-indexPapersCitations
Michael Grätzel2481423303599
Brenda W.J.H. Penninx1701139119082
Amartya Sen149689141907
Gilbert Laporte12873062608
Andre K. Geim125445206833
Matthew Jones125116196909
Benoît Roux12049362215
Stephen Mann12066955008
Bruno S. Frey11990065368
Raymond A. Dwek11860352259
David Cutts11477864215
John Campbell107115056067
David Chandler10742452396
Peter H.R. Green10684360113
Huajian Gao10566746748
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202386
2022404
20212,474
20202,371
20192,144
20181,972