14,876 research outputs found
Generalization of analytical tools for helicopter-rotor airfoils
A state-of-the-art finite difference boundary-layer program incorporated into the NYU Transonic Analysis Program is described. Some possible treatments for the trailing edge region were investigated. Findings indicate the trailing edge region, still within the scope of an iterative potential flow, boundary layer program, appears feasible
Geomagnetic modeling by optimal recursive filtering
The results of a preliminary study to determine the feasibility of using Kalman filter techniques for geomagnetic field modeling are given. Specifically, five separate field models were computed using observatory annual means, satellite, survey and airborne data for the years 1950 to 1976. Each of the individual field models used approximately five years of data. These five models were combined using a recursive information filter (a Kalman filter written in terms of information matrices rather than covariance matrices.) The resulting estimate of the geomagnetic field and its secular variation was propogated four years past the data to the time of the MAGSAT data. The accuracy with which this field model matched the MAGSAT data was evaluated by comparisons with predictions from other pre-MAGSAT field models. The field estimate obtained by recursive estimation was found to be superior to all other models
Clausewitiz on the Moral Forces in War
Clausewitz was deeply concerned with why men fight, what it is that makes wars emerge and develop as they do, and what general factors contribute to victory and defeat. However, the writing and discussion about Clausewitz \u27s book On War which have taken place during the past 30 years or so have concentrated largely on his argument that war is an extension of policy by other means. It is undoubtedly an argument basic to his whole concept of the nature of wars that actually occur as distinct from any theoretical concept of war: or, to use his own words, it is an argument which helps explain the contrast between real war on the one hand and absolute or ideal war on the other
Heritability And Selection On Clutch Size In Darwin’S Medium Ground Finches (Geospiza Fortis)
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137474/1/evo02493.pd
A study of some methods of concentrating uranium and radium in carnotite ore
Carnotite ore is a source of radium and it is the recovery of this element which is chiefly sought in its treatment. The radium results from the radioactive disintegration of uranium which is one of the constituents of the yellow mineral carnotite. The ores are largely low grade. Higher grade pockets occur scattered in the deposits and because of their irregular occurrence are not easily located. The larger low grade deposits which are more easily accessible contain considerable quantities of calcium carbonate and oxide minerals. These cause a high consumption of the acid used in the chemical treatment of the ore. The complexity of the treatment, the high acid loss, the small quantity of uranium and vanadium, and the extremely minute quantity of radium are factors which militate against a cheap and successful extraction. With these factors in mind the general characteristics of the ore were studied --Introduction, page 1
A study of liquid propellant autoignition
Data and theory pertinent to the autoignition of liquid oxygen/liquid hydrogen and liquid oxygen propellants were reviewed. Physical models of the processes supporting or contributing to autoignition were developed. Emphasis was placed on the description of the physical environment and its relationship to the autoignition phenomenon
The photon blockade effect in optomechanical systems
We analyze the photon statistics of a weakly driven optomechanical system and
discuss the effect of photon blockade under single photon strong coupling
conditions. We present an intuitive interpretation of this effect in terms of
displaced oscillator states and derive analytic expressions for the cavity
excitation spectrum and the two photon correlation function . Our
results predict the appearance of non-classical photon correlations in the
combined strong coupling and sideband resolved regime, and provide a first
detailed understanding of photon-photon interactions in strong coupling
optomechanics
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