311 research outputs found
Three dimensional flow computations in a turbine scroll
The compressible three dimensional inviscid flow in the scroll and vaneless nozzle of radial inflow turbines is analyzed. A FORTRAN computer program for the numerical solution of this complex flow field using the finite element method is presented. The program input consists of the mass flow rate and stagnation conditions at the scroll inlet and of the finite element discretization parameters and nodal coordinates. The output includes the pressure, Mach number and velocity magnitude and direction at all the nodal points
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Cranberry Research Report 2019: Defining new approaches to weed management in cranberry
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Moss as an emerging weed problem in cranberry
Abstract:
Moss is an emerging weed issue in Massachusetts and other cranberry growing regions. Although present in cranberry for decades as a minor weed, growers have recently begun to perceive it as becoming more widespread and difficult to control despite practices, such as improved drainage and water management, that should discourage moss growth. Of growers surveyed at the 2016 UMass Cranberry Management Update Meeting, 67% reported having moss on their farms (n=100), 41 % said they felt it was more common than it was 5 years ago (n=85), and 41% said they considered moss to be a problematic weed (n=96). Although the most commonly recognized and prevalent cranberry weed mosses are haircap (Polytrichum commune) and sphagnum (Sphagnum spp.), a recent sampling made in June of 2017 of State Bog in East Wareham found at least three additional moss species present (Aulacomnium palustre, Ceratodon purpureus, and Entodon seductrix).
Traditional control measures, such as spot treatment of moss patches with high rates of iron sulfate, are not adequate for managing large infestations. Recent work supported by Hatch funding has confirmed that currently registered herbicides, such as Casoron (60 lb/A), Evital (80 lb/A), Devrinol 2-XT (18 qt/A), QuinStar (8.4 oz/A x 2), or Callisto (8 oz/A x2), provided little to no control of moss. Aim (carfentrazone), a recently registered herbicide was not effective at controlling moss when applied before cranberry budbreak or in the fall after the onset of cranberry dormancy.
Over the past four years, we screened several products including acetic acid (20% horticultural vinegar), an herbicidal soap (22% ammoniated soap of fatty acids), “Product Y” (22% potassium salts of fatty acids), Impede (an insecticide with 49% potassium salts of fatty acids), and “Product X” (5.34% hydrogen peroxide). Iron sulfate products were also tested and included a feed-grade powdered form of 92% ferrous sulfate with 30% elemental iron, “Liquid turf product A” (a 35% ferric sulfate with 9.75% elemental iron product), “Liquid turf product B” (liquid turf product 15% Urea Nitrogen, 3% Combined Sulfur, 6% Iron), and “Granular turf product” (17.5% ferrous sulfate). Of these products, the only ones that injured moss and were not injurious to cranberry vines were the powdered iron sulfate (both applied as a powder and also dissolved in water), “Granular turf product”, and “Product Y” (22% potassium salts of fatty acids).
Several herbicides not currently registered for use on cranberry were screened between 2015 and 2017 for possible efficacy against moss: flumioxazin, aminocyclopyrachlor, fomesafen, halosulfuron, sulfentrazone, and pyroxasulfone. Flumioxazin and sulfentrazone both demonstrated good crop safety and moss control
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