749 research outputs found

    ORBIT: The Oregon Road Base Information Team, A Draft Summary Report

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    It is clear that transportation organizations across the nation are integrating GIS into operations at many different levels—from day to day use for data display, to full-scale enterprise level integration for operations, inventory management, research and a variety of other purposes. The cost of building and maintaining a current and accurate GIS database can be substantial within any given organization. For some smaller level organizations—small counties, cities or special districts, the cost of gathering data, organizing it and implementing systems within expensive software on an expensive operating platform can be downright discouraging. Also, as more complex data structures are accumulated a window for more comprehensive modeling and analysis of regional issues is opened. Each of these trends alone provide ample incentive to develop data standards that can be applied to all systems to facilitate data sharing between organizations for system development, system update, or project specific purposes. Taken together these trends provide an imperative to develop data-sharing standards

    EC88-2305 Six Steps to Mushroom Farming

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    Extension circular 88-2305 is six steps to mushroom farming

    Model for predicting the UHPFRC tensile hardening response

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    Ultra High Performances Fibre Reinforced Concretes (UHPFRC) are characterised by an ex-tremely low permeability and outstanding mechanical properties. These characteristics make UHPFRC suitable for locally “harden” reinforced concrete structures subjected to aggressive environments and/or mechanical stresses. Results from uni-axial tensile tests on different UHPFRC materials and cast in different directions have shown a variety of mechanical behav-iour. In particular, the hardening behaviour ranges from 0.1-0.4 % but is, in some cases, not existent. A meso-mechanical model is developed to predict the UHPFRC tensile response as a function of the volume, aspect-ratio, distribution and orientation of the fibres and the mechanical properties of the matrix. The model allows determining the effect of two parameters, the coeffi-cient of orientation and the volume of fibre, on the hardening behaviour

    Global patterns of β-diversity along the phylogenetic time-scale : the role of climate and plate tectonics

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    Aim: We aimed to assess the relative influence of the historical and contemporary processes determining global patterns of current \u3b2-diversity. Specifically, we quantified the relative effects of contemporary climate and historical plate tectonics on \u3b2-diversity at different phylogenetic scales. Location: Global. Time Period: Contemporaneous. Major taxa studied: Mammals and birds. Methods: We analysed the current \u3b2-diversity patterns of birds and mammal assemblages at sequential depths in the phylogeny, that is, from the tips to deeper branches. This was done by slicing bird and mammal phylogenetic trees into 66 time slices of 1 Ma (from 0 to 65 Ma) and recording the branches within each slice. Using global distribution data, we defined the branches\u2019 geographical distribution as the union of the corresponding downstream species distributions. For each time slice, we (a) computed pairwise \u3b2-diversity across all the grid cells for the whole world and (b) estimated the correlation between this \u3b2-diversity matrix and contemporary climatic and geographical distances, and past geological distances, a proxy for plate tectonics. Results: Contemporary climate best explained the \u3b2-diversity of shallow branches (i.e., species). For mammals, the geographical isolation of landmasses generated by plate tectonics best explained the \u3b2-diversity of deeper branches, whereas the effect of past isolation was weaker for birds. Main conclusions: Our study shows that the relative influence of contemporary climate and plate tectonics on the \u3b2-diversity of bird and mammal assemblages varies along the phylogenetic time-scale. Our phylogenetic time-scale approach is general and flexible enough to be applied to a broad spectrum of study systems and spatial scales
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