1,249 research outputs found

    ECONOMIC MODELING & OPTIMIZATION OF A REGION SPECIFIC MULTI-FEEDSTOCK BIOREFINERY SUPPLY CHAIN

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    The objective of this thesis is to include strategic and tactical level decisions into the biorefinery supply chain design for a specific region while comparing multiple conversion technologies and biomass feedstocks. The allocation of biomass feedstocks, products, and the respective supply chain configuration locations are determined while ensuring the regions monthly biomass availability and product market demand constraints are met. This research considers all actions required to bring the bio-based products to market from harvesting, storing, and processing the biomass to market distribution. Two different conversion technologies are chosen for comparison: one advanced conversion technology and one conventional technology. Potential investors and policy makers will be able to use this region specific tool by maximizing annual profitability to evaluate potential lignocellulosic biomass feedstocks and conversion technologies for the production of energy, fuels, and chemicals. The tool utilizes ILOG OPL software for optimization while interfacing with Microsoft Excel for parameter inputs and results output. From the sensitivity analysis, further insight is gained to what key drivers greatly influence the performance of each supply chain. The results demonstrate the practicality of this tool, which then can be further analyzed through other models such as discrete event simulation

    Vol. 2, No. 1 (1982)

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    Vol. 9, No. 3 (1989)

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    The cost of noise reduction for departure and arrival operations of commercial tilt rotor aircraft

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    February 1976Includes bibliographical references (p. 50-51)The relationship between direct operating cost (DOC) and noise annoyance due to a departure and an arrival operation was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various noise goals at minimum DOC. These vehicles ranged across the spectrum of possible noise levels from completely unconstrained to the quietest vehicles that could be designed within the study ground rules. Optimization parameters were varied to find the minimum DOC. This basic variation was then extended to different aircraft sizes and technology time frames. It was concluded that reducing noise annoyance by designing for lower rotor tip speeds is a very promising avenue for future research and development. It appears that the cost of halving the annoyance compared to an unconstrained design is insignificant and the cost of halving the annoyance again is small.Prepared under contract for Ames Research Center, National Aeronautics and Space Administratio

    Motor control for a brushless DC motor

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    This invention relates to a motor control system for a brushless DC motor having an inverter responsively coupled to the motor control system and in power transmitting relationship to the motor. The motor control system includes a motor rotor speed detecting unit that provides a pulsed waveform signal proportional to rotor speed. This pulsed waveform signal is delivered to the inverter to thereby cause an inverter fundamental current waveform output to the motor to be switched at a rate proportional to said rotor speed. In addition, the fundamental current waveform is also pulse width modulated at a rate proportional to the rotor speed. A fundamental current waveform phase advance circuit is controllingly coupled to the inverter. The phase advance circuit is coupled to receive the pulsed waveform signal from the motor rotor speed detecting unit and phase advance the pulsed waveform signal as a predetermined function of motor speed to thereby cause the fundamental current waveform to be advanced and thereby compensate for fundamental current waveform lag due to motor winding reactance which allows the motor to operate at higher speeds than the motor is rated while providing optimal torque and therefore increased efficiency

    A Rose for Emily

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    Edited by Beatriz Ribeir

    The Faulkner Newsletter Collected Issues

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    Introductory material to accompany the 1994 publication of The Faulkner Newsletter Collected Issues by Yoknapatawpha Press (ISBN 0916242668). The volume reprinted the first 54 issues of the publication along with an index compiled by the publishers. Includes a Letter from the Publishers , their bios, and an introduction by William Boozer

    Vol. 1, No. 1 (1981)

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    The effects of corneal eccentricity on the supplemental power effect of Bausch and Lomb Soflens contact lenses

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    The effects of corneal eccentricity on the supplemental power effect of Bausch and Lomb Soflens contact lense
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