Letters from Emma J. Mcbecker and Milton Bennion

Letters of recommendation for Frank R. Arnold

Feasibility study for reliable magnetic connection switch, phase I Final report

Feasibility of magnetic circuits for high reliability computer switche

Investigation of ultrafast laser photonic material interactions: challenges for directly written glass photonics

Currently, direct-write waveguide fabrication is probably the most widely studied application of femtosecond laser micromachining in transparent dielectrics. Devices such as buried waveguides, power splitters, couplers, gratings and optical amplifiers have all been demonstrated. Waveguide properties depend critically on the sample material properties and writing laser characteristics. In this paper we discuss the challenges facing researchers using the femtosecond laser direct-write technique with specific emphasis being placed on the suitability of fused silica and phosphate glass as device hosts for different applications.Comment: 11 pages, 87 references, 11 figures. Article in revie

Open-canopy ponds benefit diurnal pollinator communities in an agricultural landscape: implications for farmland pond management

1. Declines in pollinating invertebrates across intensively cultivated landscapes linked to reductions in flower-rich habitats constitute a key threat to biodiversity conservation and the provision of ecosystem services. Over recent decades, many ponds in agricultural landscapes have become overgrown with woody vegetation, resulting in heavily shaded, flower-poor pond basins and margins. Restoration of farmland ponds through removal of sediment and encroaching woody vegetation (canopy management) from pond margins greatly enhances freshwater biodiversity. Nevertheless, the consequences of pond management for pond-margin plants and pollinating insects remain poorly understood. Here, we studied these effects for ponds in Norfolk, eastern England. 2. We compared richness, abundance and composition of pollinating insects (hymenopterans and syrphids) and insect-pollinated plant communities between open-canopy pond systems subjected to either (i) long-term regular management of woody vegetation or (ii) recent restoration by woody vegetation and sediment removal with those communities at (iii) ponds dominated by woody vegetation. 3. Canopy management increased the richness and abundance of pollinators and insect-pollinated plants. Pollinator richness and abundance was best explained by improvements in flower resources at open-canopy ponds. Management most strongly influenced hymenopteran communities. 4. Ponds represent important semi-natural habitats for insect-pollinated plant and pollinator communities in farmland. To enhance food resources, diversity and abundance of diurnal pollinators, conservation management at ponds should aim for mosaics of ponds at different successional stages with a high proportion of early successional open-canopy ponds. Agricultural ponds are emerging as important habitats not only for aquatic biodiversity, but also for terrestrial species, thus warranting their prioritisation in future agri-environment schemes

Nocturnal pollinators strongly contribute to pollen transport of wild flowers in an agricultural landscape

Dramatic declines in diurnal pollinators have created great scientific interest in plant–pollinator relationships and associated pollination services. Existing literature, however, is generally focused on diurnal pollinating insect taxa, especially on Apidae (Hymenoptera) and Syrphidae (Diptera) pollinators, while nocturnal macro-moths that comprise extremely species-rich flower-visiting families have been largely neglected. Here, we report that in agricultural landscapes, macro-moths can provide unique, highly complex pollen transport links, making them vital components of overall wild plant–pollinator networks in agro-ecosystems. Pollen transport occurred more frequently on the moths' ventral thorax rather than on their mouthparts that have been traditionally targeted for pollen swabbing. Pollen transport loads suggest that nocturnal moths contribute key pollination services for several wild plant families in agricultural landscapes, in addition to providing functional resilience to diurnal networks. Severe declines in richness and abundance of settling moth populations highlight the urgent need to include them in future management and conservation strategies within agricultural landscapes

Palaeolimnological investigation of English Lake SSSIs

This is the final report to the Environment Agency and English Nature under an extension to project no.13063, ‘Lake Monitoring to support Environment Agency Water Framework Directive intercalibration exercise and classification tool development, and CCW Site Condition Assessment - Phase 2’, funded by the Environment Agency and English Nature. This project forms part of the UK strategy for the implementation of the European Council Water Framework Directive (WFD) which requires reference conditions to be determined for all water body types including lakes. The project is also expected to produce data of relevance to the Habitats Directive. This study aims to use palaeoecological techniques, principally diatom analysis, to describe reference conditions and assess ecological change for a set of lakes in Sites of Special Scientific Interest (SSSIs) in England. The project builds on existing palaeoecological work in the UK, in particular the ‘Identification of reference lakes and evaluation of palaeoecological approaches to define reference conditions for UK (England, Wales, Scotland & Northern Ireland) ecotypes, WFD08’ (Bennion, 2004), and aims to enhance the low resolution (core top and bottom) diatom analysis being carried out in the ongoing project ‘Development of a phytobenthos classification tool for lakes and lochs, DALES’. A further objective is to employ spheroidal carbonaceous particle analysis to estimate the time period represented by cores from selected key sites

The application of a long period grating sensors to human respiratory plethysmography

A series of nine in-line curvature sensors on a garment are used to monitor the thoracic and abdominal movements of a human during respiration for application to Human Respiratory Plethysmography. These results are used to obtain volumetric tidal changes of the human torso which show agreement with data from a spirometer used simultaneously to recorded the inspired and expired volume at the mouth during both rhythmic and transient breathing patterns. The curvature sensors are based upon long period gratings which are written in a progressive three layered fibre to render them insensitive to refractive index changes. The sensor consists of the long period grating laid upon a carbon fibre ribbon, with this then encapsulated in a low temperature curing silicone rubber. The sensing array is multiplexed and interrogated using a derivative spectroscopy based technique to monitor the response of the LPGs' attenuation bands to curvature. The versatility of this scheme is demonstrated by applying the same garment and sensors to various human body types and sizes. It was also found from statistical analysis of the sensing array data, in conjunction with the measurements taken with a spirometer, that 11 to 12 sensors should be required to obtain an absolute volumetric error of 5%

The bending and temperature characteristics of long period gratings written in elliptical core step-index fibre

We describe the characterisation of long period gratings written in elliptical core fibre, which yield a discriminatory sensor for curvature and temperature with a resolution ±0.05m-1 for curvature and ±0.9 °C for temperature

Advances in fiber grating technology for sensor applications

Sensing techniques employing UV-inscribed fibre Bragg gratings and long period fibre gratings continue to make significant advances. A number of recently established concepts are described offering improved sensor performance, multiplex capacity, and simplicity, and results from new application areas presented

Side-detection of out-coupled core light from a microfluidic fiber microslit

The interactions of the core-propagating light with an intersecting microslit within a conventional single-mode fiber are investigated. Orientation-dependent out-coupling of core light was utilized to create side-detection, miniature fiber rotation sensors