14,039 research outputs found
Passenger ride quality determined from commercial airline flights
The University of Virginia ride-quality research program is reviewed. Data from two flight programs, involving seven types of aircraft, are considered in detail. An apparatus for measuring physical variations in the flight environment and recording the subjective reactions of test subjects is described. Models are presented for predicting the comfort response of test subjects from the physical data, and predicting the overall comfort reaction of test subjects from their moment by moment responses. The correspondence of mean passenger comfort judgments and test subject response is shown. Finally, the models of comfort response based on data from the 5-point and 7-point comfort scales are shown to correspond
Application of ride quality technology to predict ride satisfaction for commuter-type aircraft
A method was developed to predict passenger satisfaction with the ride environment of a transportation vehicle. This method, a general approach, was applied to a commuter-type aircraft for illustrative purposes. The effect of terrain, altitude and seat location were examined. The method predicts the variation in passengers satisfied for any set of flight conditions. In addition several noncommuter aircraft were analyzed for comparison and other uses of the model described. The method has advantages for design, evaluation, and operating decisions
Transportation systems evaluation methodology development and applications, phase 3
Transportation systems or proposed changes in current systems are evaluated. Four principal evaluation criteria are incorporated in the process, operating performance characteristics as viewed by potential users, decisions based on the perceived impacts of the system, estimating what is required to reduce the system to practice; and predicting the ability of the concept to attract financial support. A series of matrix multiplications in which the various matrices represent evaluations in a logical sequence of the various discrete steps in a management decision process is used. One or more alternatives are compared with the current situation, and the result provides a numerical rating which determines the desirability of each alternative relative to the norm and to each other. The steps in the decision process are isolated so that contributions of each to the final result are readily analyzed. The ability to protect against bias on the part of the evaluators, and the fact that system parameters which are basically qualitative in nature can be easily included are advantageous
Data acquisition and reduction for the University of Virginia superconducting magnetic suspension and balance facility
The problems associated with data acquisition and reduction in the U. Va. superconducting magnetic suspension and balance facility are similar to those in free-flight ranges (or tunnels). The model undergoes a quasi-six-degree-of-freedom motion which must be monitored both in position and angular orientation from which the aerodynamics must be inferred. The data acquisition problem is made more difficult because geometric constraints prevent direct visual access to the model in the Mach 3 wind tunnel. The methods, accuracies, and problems associated with the acquisition of data are discussed
Relativistic Acoustic Geometry
Sound wave propagation in a relativistic perfect fluid with a non-homogeneous
isentropic flow is studied in terms of acoustic geometry. The sound wave
equation turns out to be equivalent to the equation of motion for a massless
scalar field propagating in a curved space-time geometry. The geometry is
described by the acoustic metric tensor that depends locally on the equation of
state and the four-velocity of the fluid. For a relativistic supersonic flow in
curved space-time the ergosphere and acoustic horizon may be defined in a way
analogous the non-relativistic case. A general-relativistic expression for the
acoustic analog of surface gravity has been found.Comment: 14 pages, LaTe
Black hole entropy: inside or out?
A trialogue. Ted, Don, and Carlo consider the nature of black hole entropy.
Ted and Carlo support the idea that this entropy measures in some sense ``the
number of black hole microstates that can communicate with the outside world.''
Don is critical of this approach, and discussion ensues, focusing on the
question of whether the first law of black hole thermodynamics can be
understood from a statistical mechanics point of view.Comment: 42 pages, contribution to proceedings of Peyresq
Effect of Massive Dosage of Vitamin A on the Blood Plasma Fat and Vitamin A Levels in Dairy Calves
Although the significance of vitamin A in the nutrition of the young dairy calf is well recognized, the effects of ingestion of large amounts of this vitamin, particularly as related to other blood constituents, have received comparatively little attention. Investigations with other species suggest that there may be a relationship between vitamin A intake and the level of the serum lipids. Josephs (1942) reported that the administration of large amounts of vitamin A increased total serum lipids in both normal and vitamin A-deficient rats, the effect being much greater and persisting longer in the latter. Similar results were observed in vitamin A-deficient infants (Josephs, 1945). Children with the nephrotic syndrome also displayed a marked rise in total plasma lipids following administration of vitamin A alcohol in aqueous dispersion (Kagan, Thomas, Jordan and Abt, 1950). The objective of the present study was to ascertain the effect of massive doses of vitamin A in oily and in aqueous dispersion on the blood plasma vitamin A and fat levels in dairy calves which were near the state of vitamin A deficiency
Financing Public Elementary and Secondary Education in New York State
The figures suggest that educational expenditures in New York State are not equalized on a per pupil basis and that the goal of providing equal opportunities for education, in terms of equal expenditures on education, is not even close to being achieved
Method for Treating Hair Growth Disorders, Such as Female Pattern Alopecia, and Compositions Useful Therefore
The invention relates to formulations useful in treating hair disorders, improving the health of hair, increasing hair growth, and in increasing the niacin content of hair follicles. Nicotinic acid alkyl esters having a straight chain alkyl group of from 1 to 22 methylene units, preferably from 6 to 16 methylene units, and most preferably from 8 to 14 methyl units, may be used, alone or in combinations for treating these conditions
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