18,555 research outputs found

    Viscous to Inertial Crossover in Liquid Drop Coalescence

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    Using an electrical method and high-speed imaging we probe drop coalescence down to 10 ns after the drops touch. By varying the liquid viscosity over two decades, we conclude that at sufficiently low approach velocity where deformation is not present, the drops coalesce with an unexpectedly late crossover time between a regime dominated by viscous and one dominated by inertial effects. We argue that the late crossover, not accounted for in the theory, can be explained by an appropriate choice of length-scales present in the flow geometry.Comment: 4 pages, 4 figure

    Burton\u27s 50 rules for locating and preventing errors in trial balances with the check figure nine; 50 rules for locating and preventing errors in trial balances with the check figure nine

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    The average book-keeper is so disappointed, hurt and rattled, when he finds his Trial Balance is away out of sight, that he generally spends two days doing unnecessary checking before he begins to get an idea of what he ought to have done. The following fifty rules are intended as the book-keeper\u27s friend and guide, which will beneficently point out to him the path in which he should tread, and direct him steadfastly to the goal he desires to reach

    A Large Mass of H2 in the Brightest Cluster Galaxy in Zwicky 3146

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    We present the Spitzer/IRS mid-infrared spectrum of the infrared-luminous (L_{IR}=4e11 L_sun) brightest cluster galaxy (BCG) in the X-ray-luminous cluster Z3146 (z=0.29). The spectrum shows strong aromatic emission features, indicating that the dominant source of the infrared luminosity is star formation. The most striking feature of the spectrum, however, is the exceptionally strong molecular hydrogen (H2) emission lines, which seem to be shock-excited. The line luminosities and inferred warm H2 gas mass (~1e10 M_sun) are 6 times larger than those of NGC 6240, the most H2-luminous galaxy at z <~ 0.1. Together with the large amount of cold H2 detected previously (~1e11 M_sun), this indicates that the Z3146 BCG contains disproportionately large amounts of both warm and cold H2 gas for its infrared luminosity, which may be related to the intracluster gas cooling process in the cluster core.Comment: 13 pages, 3 figures, 1 table; Accepted for publication in ApJ

    Willingness to Pay for Emission Reductions with E85

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    This study examines consumers' WTP for reductions in greenhouse gas emissions from E85 as opposed to gasoline. Data were collected via a contingent choice exercise in a 2009 national online survey. As part of the fuel choice exercise, several fuel attributes were allowed to vary including emission reductions, import level, proximity of fuel availability, price, and fuel blend (E85 or regular gasoline). A random parameters model with demographics and attitudes interacted with emission reductions was estimated. The resulting estimates suggest that, overall the WTP for an emission reduction is not statistically significant. However, for some demographic and attitudinal profiles, the WTP is significant. An example profile includes younger age, female, concerned about climate change, not supportive of additional drilling, supportive of farmland being used for fuel, own or are likely to own a FlexFuel vehicle, and primary vehicle not an SUV.Willingness to Pay, Emission Reductions, E85, Consumer/Household Economics, Environmental Economics and Policy, Q41, Q51,

    The inexorable resistance of inertia determines the initial regime of drop coalescence

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    Drop coalescence is central to diverse processes involving dispersions of drops in industrial, engineering and scientific realms. During coalescence, two drops first touch and then merge as the liquid neck connecting them grows from initially microscopic scales to a size comparable to the drop diameters. The curvature of the interface is infinite at the point where the drops first make contact, and the flows that ensue as the two drops coalesce are intimately coupled to this singularity in the dynamics. Conventionally, this process has been thought to have just two dynamical regimes: a viscous and an inertial regime with a crossover region between them. We use experiments and simulations to reveal that a third regime, one that describes the initial dynamics of coalescence for all drop viscosities, has been missed. An argument based on force balance allows the construction of a new coalescence phase diagram


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    This study determines the likely effect of cost-share incentives on participation in the Tennessee Forest Stewardship Program and identifies other factors that may contribute to participation. A random utility model is used to determine the probability that a landowner will choose to participate in the program. A binary choice model is specified to represent the dichotomous decision and a logit procedure is used to fit the model. Data are obtained from mail surveys of 4,000 randomly selected landowners. Results indicate that attitudes and knowledge of forestry programs may be more influential in a landowner's decision to participate than monetary incentives.Cost-share incentive, Stewardship Incentive Program, Logit, Nonindustrial private forest, NIPF, Participation, Forestry, Trees, Resource /Energy Economics and Policy,

    Estimating the Impacts of Storage Dry Matter Losses on Switchgrass Production

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    This poster estimates dry matter losses as a function of harvest method, storage treatment, and time in storage. We then calculate the cost to store switchgrass bales under alternate harvest method and storage treatment scenarios; and determine the breakeven harvest method and storage treatment as a function of biomass price and time in storage.Biomass, bioenergy crops, function form, sustainable systems, Farm Management, Production Economics, Q10, Q42,