29,120 research outputs found

    Analysis of secondary cells with lithium anodes and immobilized fused-salt electrolytes

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    Secondary cells with liquid lithium anodes, liquid bismuth or tellurium cathodes, and fused lithium halide electrolytes immobilized as rigid pastes operate between 380 and 485 degrees. Applications include power sources in space, military vehicle propulsion and special commercial vehicle propulsion

    On controllability and control laws for discrete linear repetitive processes

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    Repetitive processes are a distinct class of 2D systems (i.e. information propagation in two independent directions) of both systems theoretic and applications interest. They cannot be controlled by the direct extension of existing techniques from either standard (termed 1D here) or 2D systems theory. This article develops significant new results on the relationships between one physically motivated concept of controllability for the so-called discrete linear repetitive processes and the structure and design of control laws, including the case when disturbances are present

    Quasi-Chemical and Structural Analysis of Polarizable Anion Hydration

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    Quasi-chemical theory is utilized to analyze the roles of solute polarization and size in determining the structure and thermodynamics of bulk anion hydration for the Hofmeister series Cl−^-, Br−^-, and I−^-. Excellent agreement with experiment is obtained for whole salt hydration free energies using the polarizable AMOEBA force field. The quasi-chemical approach exactly partitions the solvation free energy into inner-shell, outer-shell packing, and outer-shell long-ranged contributions by means of a hard-sphere condition. Small conditioning radii, even well inside the first maximum of the ion-water(oxygen) radial distribution function, result in Gaussian behavior for the long-ranged contribution that dominates the ion hydration free energy. The spatial partitioning allows for a mean-field treatment of the long-ranged contribution, leading to a natural division into first-order electrostatic, induction, and van der Waals terms. The induction piece exhibits the strongest ion polarizability dependence, while the larger-magnitude first-order electrostatic piece yields an opposing but weaker polarizability dependence. In addition, a structural analysis is performed to examine the solvation anisotropy around the anions. As opposed to the hydration free energies, the solvation anisotropy depends more on ion polarizability than on ion size: increased polarizability leads to increased anisotropy. The water dipole moments near the ion are similar in magnitude to bulk water, while the ion dipole moments are found to be significantly larger than those observed in quantum mechanical studies. Possible impacts of the observed over-polarization of the ions on simulated anion surface segregation are discussed.Comment: slight revision, in press at J. Chem. Phy

    Highbrow Films Gather Dust: A Study of Dynamic Inconsistency and Online DVD Rentals

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    We report on a field study demonstrating systematic differences between the preferences people anticipate they will have over a series of options in the future and their subsequent revealed preferences over those options. Using a novel panel data set, we analyze the film rental and return patterns of a sample of online DVD rental customers over a period of four months. We predict and find that people are more likely to rent DVDs in one order and return them in the reverse order when should DVDs (e.g., documentaries) are rented before want DVDs (e.g., action films). This effect is sizeable in magnitude, with a 2% increase in the probability of a reversal in preferences (from a baseline rate of 12%) ensuing if the first of two sequentially rented movies has more should and fewer want characteristics than the second film. Similarly, we also predict and find that should DVDs are held significantly longer than want DVDs within-customer. Finally, we find that as the same customers gain more experience with online DVD rentals, their "dynamic inconsistency" is attenuated. We interpret our results as evidence that myopia has a meaningful impact on decisions in the field and that people learn about their myopia with experience, allowing them to curb its influence.want/should, intrapersonal conflict, dynamic inconsistency, myopia

    A finite element for thermal stress analysis of shells of revolution

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    A new finite element is described for performing detailed thermal stress analysis of thin orthotropic shells of revolution. The element provides for temperature loadings which may vary over the surface of the shell as well as through the thickness. In a number of sample calculations, results from the present method are compared with analytical solutions as well as with independent numerical analyses. Such calculations are carried out for two cylinders, a conical frustum, a truncated hemisphere, and an annular plate. Generally, the agreement between the present solution and the other solutions is excellent

    Computer mapping of turbidity and circulation patterns in Saginaw Bay, Michigan from LANDSAT data

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    The author has identified the following significant results. LANDSAT was used as a basis for producing geometrically-corrected, color-coded imagery of turbidity and circulation patterns in Saginaw Bay, Michigan (Lake Huron). This imagery shows nine discrete categories of turbidity, as indicated by nine Secchi depths between 0.3 and 3.3 meters. The categorized imagery provided an economical basis for extrapolating water quality parameters from point samples to unsample areas. LANDSAT furnished a synoptic view of water mass boundaries that no amount of ground sampling or monitoring could provide

    State Funded Marketing and Promotional Activities to Support a State's Winery Business; Are There Economic Returns?: A Case study using Texas Senate Bill 1370's support of the Texas Wine Industry

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    Texas wineries responded to a survey regarding their participation in wine marketing activities, annual changes in gross sales and level of sales growth they attribute to TDA’s support and if these funds create positive economic impacts to their winery. The response rate was 53 of the 93 registered wineries or a 57 percent response rate. Senate Bill 1370 funds allocate annually 725,000tomarketingandpromotionofTexaswine.Combiningthe725,000 to marketing and promotion of Texas wine. Combining the 725,000 and the normal funding of 250,000identifies250,000 identifies 975,000 in annual support to grow economic value. The most often utilized promotional activity is promotional materials and attending TDA supported wine events. Ninety-two percent of Texas wineries recognize an increase in awareness for the Texas wine industry and attribute 49 percent of the increase to state marketing efforts. A portion of TDA marketing funds were directed towards supporting wine events in Texas as they attract large numbers of consumers and allow promotional opportunities. One result found that 68 percent of consumers reported the event encouraged them to buy more Texas wine. Annual Economic Impact Results from supported marketing activities are estimated to create 8.42per8.42 per 1 of funding in direct sales increases, 15.33per15.33 per 1 of funding in economic impact of increases in sales and 1.54per1.54 per 1 of funding in value added impacts (based on IMPLAN Type II Economic Multiplier values). Annual Economic Impact Results from all funding activities are 2.16per2.16 per 1 of funding of total direct sales increases, 3.93per3.93 per 1 of funding in economic impacts of increases in sales and .40per.40 per 1 of funding in valued added impacts (based on IMPLAN Type II Economic Multiplier values). It is apparent that both direct and indirect economic results are positive returns to program funding and create economic growth in local economies.Texas Wine, Wine Economics, State Commodity Support, State Agricultural Marketing, State Commodity Marketing, Agribusiness, Agricultural and Food Policy, Marketing,

    Automated land-use mapping from spacecraft data

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    The author has identified the following significant results. In response to the need for a faster, more economical means of producing land use maps, this study evaluated the suitability of using ERTS-1 computer compatible tape (CCT) data as a basis for automatic mapping. Significant findings are: (1) automatic classification accuracy greater than 90% is achieved on categories of deep and shallow water, tended grass, rangeland, extractive (bare earth), urban, forest land, and nonforested wet lands; (2) computer-generated printouts by target class provide a quantitative measure of land use; and (3) the generation of map overlays showing land use from ERTS-1 CCTs offers a significant breakthrough in the rate at which land use maps are generated. Rather than uncorrected classified imagery or computer line printer outputs, the processing results in geometrically-corrected computer-driven pen drawing of land categories, drawn on a transparent material at a scale specified by the operator. These map overlays are economically produced and provide an efficient means of rapidly updating maps showing land use

    Classification and reduction of pilot error

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    Human error is a primary or contributing factor in about two-thirds of commercial aviation accidents worldwide. With the ultimate goal of reducing pilot error accidents, this contract effort is aimed at understanding the factors underlying error events and reducing the probability of certain types of errors by modifying underlying factors such as flight deck design and procedures. A review of the literature relevant to error classification was conducted. Classification includes categorizing types of errors, the information processing mechanisms and factors underlying them, and identifying factor-mechanism-error relationships. The classification scheme developed by Jens Rasmussen was adopted because it provided a comprehensive yet basic error classification shell or structure that could easily accommodate addition of details on domain-specific factors. For these purposes, factors specific to the aviation environment were incorporated. Hypotheses concerning the relationship of a small number of underlying factors, information processing mechanisms, and error types types identified in the classification scheme were formulated. ASRS data were reviewed and a simulation experiment was performed to evaluate and quantify the hypotheses

    Automatic mapping of strip mine operations from spacecraft data

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    The author has identified the following significant results. Computer techniques were applied to process ERTS tapes acquired over coal mining operations in southeastern Ohio on 21 August 1972 and 3 September 1973. ERTS products obtained included geometrically-correct map overlays, at scales from 1:24,000 to 1:250,000, showing stripped earth, partially reclaimed earth, water, and natural vegetation. Computer-generated tables listing the area covered by each land-water category in square kilometers were also produced. By comparing these mapping products, the study demonstrates the capability of ERTS to monitor changes in the extent of stripping and reclamation. NASA C-130 photography acquired on 7 September 1973 when compared with the ERTS products generated from the 3 September 1973 tape established the categorization accuracy to be better than 90%. It is estimated that the stripping and reclamation maps and data were produced from the ERTS CCTs at a tenth of the cost of conventional techniques
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