12 research outputs found

    Six-degree-of-freedom program to optimize simulated trajectories (6D POST). Volume 1: Formulation manual

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    The basic equations and models used in a computer program (6D POST) to optimize simulated trajectories with six degrees of freedom were documented. The 6D POST program was conceived as a direct extension of the program POST, which dealt with point masses, and considers the general motion of a rigid body with six degrees of freedom. It may be used to solve a wide variety of atmospheric flight mechanics and orbital transfer problems for powered or unpowered vehicles operating near a rotating oblate planet. Its principal features are: an easy to use NAMELIST type input procedure, an integrated set of Flight Control System (FCS) modules, and a general-purpose discrete parameter targeting and optimization capability. It was written in FORTRAN 4 for the CDC 6000 series computers

    Program to Optimize Simulated Trajectories (POST). Volume 1: Formulation manual

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    A general purpose FORTRAN program for simulating and optimizing point mass trajectories (POST) of aerospace vehicles is described. The equations and the numerical techniques used in the program are documented. Topics discussed include: coordinate systems, planet model, trajectory simulation, auxiliary calculations, and targeting and optimization

    Program to Optimize Simulated Trajectories (POST). Volume 3: Programmer's manual

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    Information pertinent to the programmer and relating to the program to optimize simulated trajectories (POST) is presented. Topics discussed include: program structure and logic, subroutine listings and flow charts, and internal FORTRAN symbols. The POST core requirements are summarized along with program macrologic

    Using a robot based instrument to measure the in-plane ultrasonic velocities of paper

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    "September, 1988.""Portions of this work were used by BMP as partial fulfillment of the requirements for the Master of Science degree at The Institute of Paper Chemistry. This paper has been submitted for consideration for publication in Tappi Journal.

    Status reports to the Paper Properties and Uses Project Advisory Committee

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    "October 21-22, 1986."Strength improvement and failure mechanisms: project 3469 / J. Waterhouse , W. Whitsitt ; Process, properties and product relationships: project 3467 ; G. A. Baum , C. C. Habeger ; Internal Strength enhancement: project 3526 / R. Stratton , J. Becher , K. Hardacker ; Board properties and performance: project 3571 ; W. J. Whitsitt , R. A. Halcomb ; On-line measurement of paper mechanical properties: project 3332 / C. Habeger , G. Baum -- Slide Material

    Straining and relaxation properties of wet paper during heating

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    The influence of increasing temperature on the strength and relaxation of wet press-dry paper was studied using a tensile tester equipped with a special heating chamber. The heating chamber made fast heating possible without detectable moisture loss. The results showed that temperature had a significant influence on the straining, relaxation and re-straining behavior of wet paper. The majority of observed changes due to increased temperature seem to originate from the softening of wet fibers. The observed short time scale phenomena in wet paper have practical significance for fiber webs dried under tension in paper machines. Straining–relaxation–de-straining cycles were used to analyze the effect of heating on the work of straining and apparent plastic and elastic work. Heating affected the amount of mechanical energy absorbed by the sample and the amount of elastic energy recoverable in a straining–relaxation–de-straining cycle. Increased temperature reduced the work of straining and both elastically and plastically absorbed energy. The hysteresis work of the examined wet papers was estimated to correspond to a 1–22 mK temperature change. This suggests that temperature changes in wet paper induced by straining play no role in practice. After mechanical conditioning, tensile stiffness in the re-straining of wet paper depended only marginally on temperature, whereas in initial straining the effect of temperature was clearly stronger. The linear thermal expansion coefficient of wet paper in the machine direction was estimated and the influence of moisture content on the linear thermal expansion coefficient of paper was found to be relatively small
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