36,388 research outputs found

    Photographic technology development project: Timber typing in the Tahoe Basin using high altitude panoramic photography

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    Procedures were developed and tested for using KA-80A optical bar camera panoramic photography for timber typing forest land and classifying nonforest land. The study area was the south half of the Lake Tahoe Basin Management Unit. Final products from this study include four timber type map overlays on 1:24,000 orthophoto maps. The following conclusions can be drawn from this study: (1) established conventional timber typing procedures can be used on panoramic photography if the necessary equipment is available, (2) The classification and consistency results warrant further study in using panoramic photography for timber typing; and (3) timber type mapping can be done as fast or faster with panoramic photography than with resource photography while maintaining comparable accuracy

    Nationwide forestry applications program. Ten-Ecosystem Study (TES) site 6, Fort Yukon, Alaska

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    The author has identified the following significant results. Analysis of the processing results has led to the following conclusions: (1) LANDSAT imagery was a reliable resource for the stratification of level 2 forest features (softwood, hardwood, tundra, and water). These features can be classified with an accuracy of 72.4 percent + or - 5.9 percent at the 90 percent confidence level. (2) Training fields selected for signature development from only 10 percent of the area did not adequately and efficiently cover the class variability for the entire area. (3) Derived regression transformations were ineffective in recovering the loss of level 1 forest proportions and level 2 softwood and hardwood proportions

    Aggregates : is there a need for indigenous production in England?

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    Quality of life in a modern society depends on having the right infrastructure, of the right quality, in the right places – housing, schools, hospitals, transport links, workplaces and recreation facilities. All these elements of the built environment require aggregates in their construction. However many people today fail to make the connection between their standard of living and the quarries that are required to provide that standard. With the opposition to mineral extraction becoming more vociferous and with increasing competition for land uses, this research project, funded through the Aggregates Levy, examined England’s true ‘need’ for aggregates together with the costs and benefits to society and the economy of indigenous supply. It also considered whether it is physically possible to import large quantities of aggregates and assessed the likely implications of doing so. The research found that the demand for aggregates is created by society’s desire for a high standard of living and that the true ‘need’ is to meet that demand. It determined that aggregates extraction directly contributes £810 million to the English economy and this outweighs the estimated environmental cost of indigenous extraction of approximately £445 million. England’s current aggregates requirement is more than double the existing port capacity for dry bulk cargoes and importing large quantities of aggregates would likely double the cost of this material, with serious consequences for downstream industries. There will continue to be a need to meet demand for aggregates and this will have to be provided mainly from indigenous sources for the foreseeable future

    On the Running of the Cosmological Constant in Quantum General Relativity

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    We present arguments that show what the running of the cosmological constant means when quantum general relativity is formulated following the prescription developed by Feynman.Comment: 5 page

    On the horseshoe drag of a low-mass planet. I - Migration in isothermal disks

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    We investigate the unsaturated horseshoe drag exerted on a low-mass planet by an isothermal gaseous disk. In the globally isothermal case, we use a formal- ism, based on the use of a Bernoulli invariant, that takes into account pressure effects, and that extends the torque estimate to a region wider than the horse- shoe region. We find a result that is strictly identical to the standard horseshoe drag. This shows that the horseshoe drag accounts for the torque of the whole corotation region, and not only of the horseshoe region, thereby deserving to be called corotation torque. We find that evanescent waves launched downstream of the horseshoe U-turns by the perturbations of vortensity exert a feed-back on the upstream region, that render the horseshoe region asymmetric. This asymmetry scales with the vortensity gradient and with the disk's aspect ratio. It does not depend on the planetary mass, and it does not have any impact on the horseshoe drag. Since the horseshoe drag has a steep dependence on the width of the horseshoe region, we provide an adequate definition of the width that needs to be used in horseshoe drag estimates. We then consider the case of locally isothermal disks, in which the tempera- ture is constant in time but depends on the distance to the star. The horseshoe drag appears to be different from the case of a globally isothermal disk. The difference, which is due to the driving of vortensity in the vicinity of the planet, is intimately linked to the topology of the flow. We provide a descriptive inter- pretation of these effects, as well as a crude estimate of the dependency of the excess on the temperature gradient.Comment: Accepted for publication in Ap

    Estimates of Radiation by Superluminal Neutrinos

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    We show that the more energetic superluminal neutrinos with quadratically dispersed superluminalities \delta=\beta^2-1, for \beta=v/c where v is the neutrino velocity, also lose significant energy to radiation to the \nu+e^-+e^+ final state in travelling from CERN to Gran Sasso as has been shown to occur for those with constant superluminality by Cohen and Glashow if indeed \delta \simeq 5\times 10^{-5}. In addition, we clarify the dependence of such radiative processes on the size of the superluminality.Comment: 6 pages, no figures; text re-arranged for journal purposes; improved references; published version(title changed by Editors
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