581 research outputs found

    Dynamic and tribological analysis of a toroidal CVT

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    The continuously variable transmission investigated in this paper works with contacts in the elastohydrodynamic regime of lubrication, thus the tangential forces are transmitted between elements through the shearing the lubricant film. The behavior of the lubricant film when subjected to shear depends of the nature of the lubricant and the relative motion between the contacting surfaces. In this paper a non-Newtonian behavior is assumed for the lubricant while the relative motion is determined for every point on the contact area by kinematic methods. The net tractive force in the sliding direction, and the spin torque are evaluated and from these the power losses in the contacts are calculated. The dynamic behavior of the device is evaluated taking into account the rheological behavior of the lubricant

    Experimental Concrete Pavement Containing Fly-Ash Admixtures [1971]

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    The report enclosed is somewhat routine inasmuch as it documents a repeat of a portion of an earlier experimental project. The previous project was on Poplar Level Road; our final report was dated July 1966 (KYHPR-64-1). Special Provision No. 70 was used also on the Jefferson Freeway project. However, there was no control section involved in the current project. The Jefferson Freeway project was authorized by the BPR under P.P.M. 60-2 only (now PPM 20-6.3). The most significant findings from both projects concern the water requirements the concrete containing the fly-ash admixture. Whereas laboratory tests indicated reasonable expectations of a reduction in water demand in the fly-ash concrete -- in comparison to normal concrete -- these expectations were not realized during construction of either project; and so that peculiar phenomenon persists and remains unexplainable

    The 1994 Federal Crime Bill: An Evaluation of the Past, Present, and Future of its Impact on the Criminal Justice System

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    The 1994 Violent Crime Control and Law Enforcement Act was signed into law in response to the crack cocaine and crime epidemic of the 1980s. In this thesis I address the major elements of this bill, the racial, financial, and ethical conflicts that arose thereafter, and the reforms that should be implemented today to correct said conflicts

    ECONOMIC EVALUATION OF INCOME PROTECTION CHOICES FOR WEST TENNESSEE CORN PRODUCERS

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    Farmers need information about the expected value and variability of net revenues for alternative crop insurance and futures hedging strategies to manage risk. Specifically, the model will determine which risk management strategies are most desirable under various levels of risk aversion. The unstable futures basis relation in the data used in the simulation model contributed to increased variability of net revenues. In general, none of the crop insurance or hedging strategies markedly reduced variability of net revenue and relative riskiness when compared with the cash strategy. Revenue Assurance strategies were the most effective at setting a floor on net revenues. As a result, Revenue Assurance products may perform well for extremely risk averse producers.Marketing, Risk and Uncertainty,

    The off-specular peak and polarisation effects of an undulating underwater suface

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    http://www.hydrooptics.spb.ru/onw2005/index.phpPeriodic undulations are used to describe underwater bottom roughness. An expression of the bi-directional reflectance distribution function (BRDF) is given that is dependent on the given roughness metric. Highlights include an off-specular peak and polarisation effects. For an undulating underwater surface, we have shown through geometric optics that reflectance from a rough diffuse surface increases as the viewing direction approaches the backward direction even in the absence of shadowing and/or self-shading (Clavano & Philpot (2003), see also Cox & Munk (1956)). The effects of shadowing and self-shading are equivalent to applying a geometrical attenuation factor to specular reflectance, which is similar to an analysis of morphological effects using triangular waves by Zaneveld & Boss (2003). We show that a reflectance peak displaced away from the specular direction occurs at large angles of incidence (relative to the global normal) as the surface gets rougher (part of work in Clavano & Philpot (2004)). Similar results have been shown for oil films on ocean surfaces using Monte Carlo methods by Otremba & Piskozub (2004) and Otremba (2004). As a general result, an expression of the full bi-directional reflectance distribution function (BRDF) is given. While geometrical effects play a significant role in the reflectance distribution, we consider polarisation effects (as in Mullamaa (1962, 1964)) to gain more insight into real-world reflectances and compare with empirical distributions described by Cox & Munk (1956).Cornell University Graduate Schoo

    Replication of Eye-Bars and Measurement of Losses in Cross Section Due to Corrosion

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    Recent availability of high pressure water blasters made it possible to remove rust accumulated between the eye-bars near pin connections on the Central Bridge (Figure 1) over the Ohio River at Newport. Previously, they had never been thoroughly cleaned. Cleaning of two connections on a trial basis enabled an inspection between the bars. It was apparent then that the deterioration was critical enough to necessitate examination of the several bar groups and to accurately measure their least cross sections. The Research Division undertook the task of replicating and measuring the bars. Figures 2 and 3 show one set of bars before and after cleaning. Considerable difficulty was encountered in making moldings or impressions because the space between the two center bars, referred to here as 1, 2, 3 and 4 (Figure 4), varied between one-quarter and one-half inch. Thin sheet metal forms (Figure 5) were used to fit around each section. These forms were then tied in place (Figure 6) and sealed around the edges with paraffin to prevent liquid leakage. A two-component compound, referred to as Sika-Flex, was used to rill these forms and provide a negative molding. Sika-Flex is a liquid joint filler which hardens into a rubbery type of material after mixing --- thereby retaining the exact shape of the bar sections after removal. Wire mesh was used inside the forms around the bars to prevent stretching or deformation of the Sika-Flex mold. Figures 7 and 8 show the forms installed. The forms were removed after several hours of curing and taken to the laboratory where hydrostone was used to make an exact positive casting of the bar sections (Figure 9). Thereafter, each of these replicates was measured at three or four places where the least section was thought to be. A contour gauge was used to transfer these cross sections onto paper and then the area was measured with a planimeter. This method is believed to be reasonably accurate. The percent loss of section in each bar was calculated in reference to the original section taken from calculations made previously by the Maintenance Division. A key for identifying the bars as listed is provided in Figure 10. Attached are copies of the measured sections of the respective bars listed in Table 1

    SOIL PROPERTIES AND LANDTYPES--CLASSIFICATION AND IDENTIFICATION WITH DISCRIMINANT ANALYSIS

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    Intensive land use is requiring more detailed information about patterns and magnitudes of soil variability than can be acquired through traditional soil survey techniques. Discriminant analysis is a mathematical method of numerical classification which could be used to identify discrete populations of soils in their natural settings. The hypothesis of this study was that discriminant analysis could be used to group soils on landtypes on the Mid-Cumberland Plateau. A large data set (132 observations of 29 soil variables) was collected from three landtypes at two Cumberland Plateau locations. Discriminant analysis was used to classify the soil observations into landtypes. Canonical correlation was used to identify soil properties most responsible for separating soils into groups related to landtypes. Not all of the collected soil properties were important discriminators, so variables with low canonical loading scores were eliminated. A total of 13 soil variables representing three genetic soil horizons was required to correctly classify all 132 observations into correct landtypes. Canonical correlations were 0.979 and 0.970 with 29 variables and 0.968 and 0.941 with 13 variables on canonical variates one and two, respectively. Soil variables from Bt horizons alone did not classify all observations into correct landtypes. Discriminant analysis, in conjunction with canonical correlation, shows promise for identifying key variables for numerically classifying soils into related populations

    Application of LANDSAT to the management of Delaware's marine and wetland resources

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    The author has identified the following significant results. LANDSAT data were found to be the best source of synoptic information on the distribution of horizontal water mass discontinuities (fronts) at different portions of the tidal cycle. Distributions observed were used to improve an oil slick movement prediction model for the Delaware Bay. LANDSAT data were used to monitor the movement and dispersion of industrial acid waste material dumped over the continental shelf. A technique for assessing aqueous sediment concentration with limited ground truth was proposed

    Skylab/EREP application to ecological, geological, and oceanographic investigations of Delaware Bay

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    Skylab/EREP S190A and S190B film products were optically enhanced and visually interpreted to extract data suitable for; (1) mapping coastal land use; (2) inventorying wetlands vegetation; (3) monitoring tidal conditions; (4) observing suspended sediment patterns; (5) charting surface currents; (6) locating coastal fronts and water mass boundaries; (7) monitoring industrial and municipal waste dumps in the ocean; (8) determining the size and flow direction of river, bay and man-made discharge plumes; and (9) observing ship traffic. Film products were visually analyzed to identify and map ten land-use and vegetation categories at a scale of 1:125,000. Digital tapes from the multispectral scanner were used to prepare thematic maps of land use. Classification accuracies obtained by comparison of derived thematic maps of land-use with USGS-CARETS land-use maps in southern Delaware ranged from 44 percent to 100 percent
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