490 research outputs found
SAMPLING AND MODELING OF SEDIMENT TRANSPORT AND RESERVOIR EROSION FOLLOWING DAM REMOVAL: MILLTOWN DAM, MONTANA
Measurements of bedload transport in combination with suspended sediment and discharge data collected by the USGS illustrate the rates, magnitudes and processes by which reservoir sediment evacuated the Milltown Reservoir after the 2008 removal of Milltown Dam from just downstream of the confluence of the Blackfoot and Clark Fork Rivers, Montana. Mobilized sediments transported as a series of distinct waves and the speed at which the waves moved downstream was dependent upon the grain size of the sediment. Sand and smaller sized particles were transported out of the reservoir rapidly both as bedload and in suspension with different thresholds for incipient motion between the confined Blackfoot and unconfined alluvial Clark Fork Arms of the reservoir. Bedload sediments, gravel and larger sized, transported downstream as a dispersing and translating wave. Sediment budget calculations, both volumetric and transport derived, illustrate the one-dimensional HEC-6 and DREAM-1 modelâs inaccuracy in predicting sediment transport in unconfined alluvial deposits while both models predicted accurately confined channel geometry transport settings. Results from sampling and modeling demonstrate that the most important factors in reservoir sediment transport are the channel geometry, hydrology, and grain size and location of the reservoir sediment; which in turn determine distance, processes and timing of transport
Study to Determine the Effect of Word Frequency on Copy Difficulty for Shorthand Dictation Material
Business Educatio
Rooting Responses of Selected Ornamental Plants as Influenced by Various Nutrient Mists and Sprays
Ornamental Horticultur
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Measuring Capacity of the New England Otter Trawl Fleet
Measurement of capacity in marine fisheries is an important activity. An economic definition of capacity is the output level corresponding to the tangency between the long-run and short-run average cost curves. A technological-engineering definition is the maximum output per unit of time provided variable inputs are unrestricted. Although cost data to support an economic measurement of capacity in fisheries are not routinely available, data are typically available to support the technological-engineering measure of capacity. Our paper provides an assessment of the technological-engineering concept of capacity in the New England multispecies otter trawl fishing fleet. Based on FĂ€re et al. (1994), we calculate capacity using Data Envelopment Analysis (DEA), a non-parametric technique which utilizes linear programming methods to evaluate the performance of individual firms. DEA is ideally suited to assess capacity in fisheries because it easily accommodates multiple output-multiple input technologies. The New England otter trawl fleet was used as a study fleet because it has a multi-product nature, and is comprised of a wide variety of vessel types and sizes.
Keywords: Capacity, Data Envelopment Analysis, New England Otter Trawl Flee
Itâs in the Fine Print: Erasable Three-Dimensional Laser-Printed Micro- and Nanostructures
3D printing, on all scales, is currently a vibrant topic in scientific and industrial research as it has enormous potential to radically change manufacturing. Owing to the inherent nature of the manufacturing process, 3D printed structures may require additional material to structurally support complex features. Such support material must be removed after printingâsometimes termed subtractive manufacturingâwithout adversely affecting the remaining structure. An elegant solution is the use of photoresists containing labile bonds that allow for controlled cleavage with specific triggers. Herein, we explore stateâofâtheâart cleavable photoresists for 3D direct laser writing, as well as their potential to combine additive and subtractive manufacturing in a hybrid technology. We discuss photoresist design, feature resolution, cleavage properties, and current limitations of selected examples. Furthermore, we share our perspective on possible labile bonds, and their corresponding cleavage trigger, which we believe will have a critical impact on future applications and expand the toolbox of available cleavable photoresists
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