Digitisation of electron microscope films: six useful tests applied to three film scanners

A series of simple tests have been used to measure the performance of flat-bed film scanners suitable for digitisation of electron micrographs. Two of the film scanners evaluated are commercially available and one has been constructed in the laboratory paying special attention to the needs of the electron microscopist. The tests may be useful for others.     

Measurement of styrene oxide in polystyrenes, estimation of migration to foods, and reaction kinetics and products in food simulants

The concentration of styrene-7,8-oxide has been measured in nine base resins and 16 samples of polystyrene articles intended for food contact. The epoxide was not detected in the resins (limit of detection 0.5 mg/kg) but was found in 11 of the 16 packaging samples at up to 2.9 mg/kg. Assuming that the propensity of styrene oxide to migrate is the same as styrene monomer, and using existing survey data for styrene monomer in packaging and foods, the migration levels expected for styrene oxide were calculated. Estimates were from 0.002 to 0.15 microgram/kg styrene oxide in foods. The stability of styrene oxide in the four standard EU food simulants was studied at 40, 100, 150 and 175 degrees C, to establish the transformation products to be expected following migration testing. The half-life at 40 degrees C in distilled water, 15% aqueous ethanol, 3% aqueous acetic acid and olive oil was 15, 23, < 1, > 2000 hr, respectively. The principal product was the diol from hydrolysis of the epoxide group. Ring opening in aqueous ethanol simulant gave the diol and also the glycol monoethyl ether. It is concluded that this instability of styrene oxide will reduce concentrations in foods, from an already low migration level to even lower levels with the formation of hydrolysis products that are less toxic than the parent epoxide.     

Analysis of stripline-fed slot-coupled patch antennas with vias forparallel-plate mode suppression

The paper presents an analysis of slot-coupled stripline-fed patch antennas with vias around the slot to minimize the power launched into the parallel-plate mode. A moment-method scattering formulation is invoked to include the effect of vias on the impedance characteristics of the antenna. Coupling between the stripline feed and the ground-plane slot is obtained by invoking reciprocity. Two design examples were fabricated and the measured input impedances verify the accuracy of the analysis. Vias considerably modify the impedance and resonant characteristics of a patch antenna. The radiation efficiency of patch antennas with and without vias is studied and proper location of the vias is shown to drastically reduce power in the parallel-plate mode     

Flood Hazard Assessment and Management: Interface with the Public

The understanding of how people evaluate and respond to natural hazards in an urban area, and how this knowledge can be integrated in the planning and management process, are becoming very important elements of a comprehensive and participatory approach to flood hazard management. Such an approach demands a clear comprehension of the processes of the risks perception, causal attribution, possible solutions for the problem and patterns of behaviour developed during hazard situations. The willingness of the public to participate in flood management, and the attitudes to previous initiatives also need to be addressed. The provision of structural flood defences can have a major impact on the environment and there has been an expression of concern by many members of the public for the degradation of river corridors. In this context, it is becoming a commonly accepted practice by central or local governments to submit flood management plans to public discussion. Appropriate techniques for interfacing with the public are necessary to support this upsurge of public involvement. This paper presents results from research on public perception of floods, flood management and participatory initiatives in Setúbal, Portugal. An extensive interview programme was undertaken with residents and shopkeepers – with and without flood experience, professionals responsible for dealing with flood control problems and local authorities responsible for decision-making on flood management. The paper concludes with a number of recommendations for flood hazard management policy making and processes.     

Initial Experience with the Milton Keynes Optical Fiber Cable TV Trial

This paper describes a small trial of an advanced cable TV network with evolutionary potential for the wideband local network of the future. Major features of the trial are optical fiber transmission throughout, switched program provision, and a star type of network. Initial experience is related giving both successes and difficulties encountered on design and installation phases. The conclusions point out the technology gap that exists for the wideband local network application and emphasize the potential of the network type used for enhanced services to the customer.     

Spinal intradural cerebellar ectopia

We present a case of multilocular cystic nephroma with an unusual localization treated by a nephron-sparing procedure. A 21-year-old white woman presented with a history of hematuria and right lumbar pain. Imaging techniques revealed a multilocular cystic mass originating from the renal parenchyma but mainly involving the renal pelvis. The lesion was localized almost entirely within the renal pelvis at surgery and was treated by excision. Pathologic analysis was consistent with multilocular cystic nephroma. The patient remains free of recurrence with 10 years of follow-up. We conclude that multilocular cystic nephroma may present as a cystic lesion localized within the renal pelvis, and we advocate simple excision of these lesions.     

An evaluation of flood forecasting,warning and response systems in the European Union

This paper presents results from the EUROflood research project sponsored by the European Commission under the EPOCH programme. The paper evaluates levels of development of flood forecasting, warning and response systems (FFWRS) in the European Union with reference to riverine and tidal floods in The Netherlands, the United Kingdom, Germany, France and Portugal. An experimental evaluation methodology, comprising fourteen criteria and five development stages, is used to evaluated FFWRS. Flood forecasting is the starting point, but the research addresses entire FFWRS. Despite advances in flood forecasting, FFWRS often under-perform because warning dissemination and response are unsatisfactory.FFWRS have developed in response to different water resource management problems, varying flood characteristics and different historic, cultural and institutional factors. FFWRS for flood defence and flood emergency response are the main focus, but they are also important for navigation, bridge clearance, fishing, recreation and industry. France, parts of Germany, The Netherlands and England and Wales have relatively mature FFWRS. FFWRS are much less well developed in Scotland, Northern Ireland and Portugal, and important areas for enhancement are identified in all countries. Cross-country and within-country comparisons reveal the potential for knowledge transfer, although ultimately the unique circumstances of each country places limits upon this process.     

Sample preparation for aflatoxin assay: The nature of the problem and approaches to a solution

Cases have been reported of individual peanuts, cottonseeds or Brazil nuts so highly contaminated with aflatoxin that, for a 50 g portion to be representative of the whole, the sample preparation procedures should grind each unit to a large number of particles and distribute them uniformly throughout the sample. Assuming uniform contamination of the individual kernel, each 50 g sample should contain 1/100 of that kernel. Even though these extreme cases may be encountered only infrequently, the more usual situation still presents difficulties because of great variability in individual kernel contamination. However, if the extreme can be handled, one can expect to handle the more usual situation. Equipment and procedures to achieve this distribution goal are described. The equipment studied includes a food chopper (Hobart), a nut mill (Thomas Mills), a disc mill (Bauer), a hammer mill (Fitzpatrick Model D comminuting machine), a hammer mill designed specifically for peanut samples (Dicken’s subsampling mill), a Polytron homogenizer (Bronwill Scientific), a vertical cutter-mixer (Hobart), and a sample splitter (Jones riffle). Commodities examined were shelled peanuts and in-shell Brazil nuts, walnuts, pecans and almonds. Comminution and mixing effectiveness were determined by particle size analysis, by distribution of kernels made radioactive by neutron activation and by aflatoxin analysis of naturally contaminated products. From the results we conclude that the ultimate in sample uniformity can be achieved with a disc mill, solvent addition to obtain a fluid system and mixing and grinding of the fluid with a dispersion mixer-grinder. A practical uniformity can be achieved in a vertical cutter-mixer with less expenditure of time and effort for the commodities studied. Presented in part at the AOCS-AACC Joint Meeting, Washington, D.C., April 1968.     

The impact of large scale atmospheric circulation patterns on wind power generation and its potential predictability: A case study over the UK

Over recent years there has been an increasing deployment of renewable energy generation technologies, particularly large-scale wind farms. As wind farm deployment increases, it is vital to gain a good understanding of how the energy produced is affected by climate variations, over a wide range of time-scales, from short (hours to weeks) to long (months to decades) periods.By relating wind speed at specific sites in the UK to a large-scale climate pattern (the North Atlantic Oscillation or “NAO”), the power generated by a modelled wind turbine under three different NAO states is calculated. It was found that the wind conditions under these NAO states may yield a difference in the mean wind power output of up to 10%. A simple model is used to demonstrate that forecasts of future NAO states can potentially be used to improve month-ahead statistical forecasts of monthly-mean wind power generation.The results confirm that the NAO has a significant impact on the hourly-, daily- and monthly-mean power output distributions from the turbine with important implications for (a) the use of meteorological data (e.g. their relationship to large-scale climate patterns) in wind farm site assessment and, (b) the utilisation of seasonal-to-decadal climate forecasts to estimate future wind farm power output. This suggests that further research into the links between large-scale climate variability and wind power generation is both necessary and valuable.     

Oblique-tip fiber-optic sensors for multiphase fluid discrimination

This paper describes several novel designs of fiberoptic sensor made from standard silica fibers with plane oblique facets polished at the fiber tip, and various surface treatments. All use the phenomenon of total internal reflection (TIR) to distinguish drops, bubbles or other moieties of immiscible fluids in a multiphase flow, on the basis of contrast in refractive index. Surface treatments for control of wettability can be critical to some of the conceptions. Depending on the geometry chosen, sensors with quasibinary outputs may be made to distinguish various pairs of immiscible fluids (liquid/gas or oil/“not-oil”). Sensor pairs may then be used for discrimination of three mutually immiscible phases (oil, water, gas) in complex flows. Example outputs from prototype sensors in laboratory test flows are shown