29 research outputs found

    NMR Experiments on a Three-Dimensional Vibrofluidized Granular Medium

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    A three-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient (PFG) NMR coupled with one-dimensional magnetic resonance imaging (MRI). The system consisted of mustard seeds vibrated vertically at 50 Hz, and the number of layers N_ell <= 4 was sufficiently low to achieve a nearly time-independent granular fluid. Using NMR, the vertical profiles of density and granular temperature were directly measured, along with the distributions of vertical and horizontal grain velocities. The velocity distributions showed modest deviations from Maxwell-Boltzmann statistics, except for the vertical velocity distribution near the sample bottom which was highly skewed and non-Gaussian. Data taken for three values of N_ell and two dimensionless accelerations Gamma=15,18 were fit to a hydrodynamic theory, which successfully models the density and temperature profiles including a temperature inversion near the free upper surface.Comment: 14 pages, 15 figure

    Advances in MASELTOV – Serious Games in a Mobile Ecology of Services for Social Inclusion and Empowerment of Recent Immigrants

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    Immigration imposes a range of challenges with the risk of social exclusion from the information society (Halfman 1998), such as, getting into communication with the local society and understanding the culture of their host nation. Failure to address these challenges can lead to difficulties in the frame of integrating into the society of the host country, leading to fragmented communities and a range of social issues. As part of a comprehensive suite of services for immigrants, the European project seeks to provide both practical tools and learning services via mobile devices, providing a readily usable resource for immigrants. We introduce recent results, such as the game-based learning aspect of the MASELTOV project is introduced, with the rationale behind its design presented. In doing so, the benefits and implications of mobile platforms and emergent data capture techniques for game-based learning are discussed, as are methods for putting engaging gameplay at the forefront of the experience whilst relying on rich data capture and analysis to provide an effective learning solution

    Ground conditions in central Manchester and Salford : the use of the 3D geoscientific model as a basis for decision support in the built environment

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    In the urban environment, site investigation studies provide a wealth of information about the ground conditions of the shallow subsurface. However, from the developers’ perspective, there is generally little incentive to integrate this information beyond the boundaries of the development site. By taking a more holistic view and combining knowledge of the near-surface geology with information on former land use and the groundwater regime across a wider area, it is possible to predict geological scenarios that may better inform ground investigation and reclamation strategies. As part of its urban research programme, the British Geological Survey has integrated its data holdings across 75 km2 of central Manchester and Salford. The information has been used to develop an integrated 3D model of the shallow subsurface. By exporting the elements of the model to a Geographical Information System (GIS), there is the capability to produce on demand bespoke maps, crosssections and other visualisation aids, relevant to regional planning and site appraisal. The value of such a system is illustrated by reference to five topic areas (geology, geotechnical engineering, hydrogeology, geochemistry and land use). A series of thematic maps illustrates the range of outputs. The approach provides a means of identifying potential problems and opportunities at an early stage in any proposed development and, if implemented over a wider area, it could assist in designing site investigation strategies and reduce costs by ensuring a more focused approach to development planning

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    3-D geoscience models and their application to hydrogeological domains mapping

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    The sustainable management of groundwater resources is increasingly important as part of the development and implementation of European Union (EU) legislation and directives. 3-D geoscience models are becoming used not only as visualisation tools but also as a basis for assessments of aquifer recharge and vulnerability in order to allow regulators to satisfy legislative requirements. The British Geological Survey has developed attributed, 3-D geoscience models of the shallow-subsurface in order to derive hydrogeological domains for the assessment of aquifer recharge and vulnerability. 3-D geoscience models of complex areas of natural and artificial superficial deposits have been built for UK environmental regulators, the Environment Agency, in areas underlain by Permo-Triassic rocks of the Sherwood Sandstone Group. The Sherwood Sandstone Group constitutes one of the major aquifers in the UK. In the Manchester – Salford area in north-west England, detailed GIS analysis of the attributed 3-D geological model was used to derive hydrogeological domains to assess the vulnerability of the underlying aquifer to pollution in one of the major population centres of the UK. In the Doncaster – Retford area of north-eastern England, hydrogeological domains were produced to assess the extent to which recharge was likely to occur into the underlying aquifer and its potential effect on near-by ecological receptors. Just as important as the models themselves is the way in which the 3-D information is presented. The British Geological Survey has implemented the use of the SUBSURFACE VIEWER (© INSIGHT GmbH) enabling specialist and non-specialist users to fully analyse attributed 3-D ground information. Visualisation of 3-D ground information in this way enables effective and sustainable decisions about land use and groundwater management to be made

    Choice of grazed herbage or maize silage by lactating dairy cows: influence of sward height and concentrate level Preferência por pastagem ou silagem de milho por vacas leiteiras em lactação: influência da altura do pasto e do nível de concentrado

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    The preference of lactating dairy cows for grazed herbage or maize silage (MS), simultaneously offered ad libitum in the field, was examined at two sward heights (SH 4-6 and 8-10cm) and two concentrate levels (CL 0 and 6kg day-1) in a 2x2 factorial arrangement within a completely randomised experimental design. The experiment lasted 35 days and was carried out in spring using 24 multiparous Holstein Friesian cows. On average, the cows proportionately spent more time grazing than eating MS (0.85:0.15) and even though the higher rate of intake (RI) of dry matter (DM) of MS compared with grazed herbage (76 versus 26g DM min-1), the proportion of total DM intake as herbage was higher compared to that of MS (0.56:0.44). The higher crude protein and low fibre content of grazed herbage appeared to have a higher priority of choice than RI, as the cows chose to graze for longer (grazing time 385 min, MS feeding time 67min) despite the lower RI of herbage. The low proportion MS intake indicated that RI was a secondary factor of choice. Concentrate supplementation had a greater depressing effect on herbage intake than on MS intake. These results suggest that the animals reduce the intake of feed with lower RI when the labor associated to eat is decreased. The factors influencing the choice for herbage over maize silage remain unclear.<br>A preferência de vacas leiteiras em lactação por pasto ou silagem de milho (SM) oferecidas ad libitum simultaneamente no pasto foi avaliada quanto a duas alturas de pastagem (4-6 e 8-10cm) e dois níveis de concentrado (0 e 6kg dia-1), em um arranjo fatorial 2x2 dentro de um delineamento inteiramente ao acaso. O experimento, com duração de 35 dias, foi executado na primavera utilizando 24 vacas multíparas da raça Holandesa. As vacas passaram, em média, proporcionalmente mais tempo pastando do que comendo SM (0,85:0,15) e, mesmo considerando a maior taxa de consumo (TC) de matéria seca (MS) de SM comparada com a da pastagem (76 versus 26g MS min-1), a proporção do total do consumo de MS como pastagem foi mais alta comparada com aquela da SM (0,56:0,44). A proteína crua mais alta e o menor conteúdo de fibra da pastagem pareceram ter prioridade na escolha pelos animais do que a TC, pois as vacas preferiram pastar por mais tempo (tempo de pastejo = 385min, tempo para comer SM = 67min), não obstante ter havido menor TC na pastagem. A baixa proporção de consumo de SM indicou que a TC foi um fator secundário na preferência dos animais. A suplementação concentrada teve maior efeito depressor no consumo de pastagem que o consumo de SM. Estes resultados sugerem que a prioridade dos animais, quando o trabalho associado com o comer é reduzido, é o de diminuir o consumo de alimento com menor TC. Os fatores que influenciaram a preferência por pastagem sobre silagem de milho ainda não são totalmente claros
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