Profile Determination of Plate Cams with Oscillating Convex Arbitrary-Shaped Followers

Author(s):  
G S Hwang ◽  
D M Tsay ◽  
M H Huang

A universal form of profile equation for a plate cam whose follower has an oscillating motion and a convex arbitrary shape is derived in this study. The applied concept is the theory of envelopes in a parametric form. The derived results can be used to determine the profile of the cam with any kind of convex shape of the followers. It is also shown that the traditional followers, such as flat-faced and roller followers, are special cases of the universal form.

1953 ◽  
Vol 20 (2) ◽  
pp. 279-285
Author(s):  
S. R. Heller

Abstract The object of this paper is the determination of the effect of the reinforcement of circular holes on the stress distribution in the webs of beams subjected to bending with shear. A theoretical solution for a bead-type reinforcement, i.e., small radial thickness, is developed. The stress distribution in the web for arbitrary shape reinforcement is based on the work of Reissner and Morduchow (1). The theory developed is valid provided the diameter of the hole does not exceed one fourth of the depth of the beam.


1947 ◽  
Vol 14 (2) ◽  
pp. A113-A118
Author(s):  
C. Concordia ◽  
G. K. Carter

Abstract The objects of this paper are, first, to describe an electrical method of determining the flow pattern for the flow of an incompressible ideal fluid through a two-dimensional centrifugal impeller, and second, to present the results obtained for a particular impeller. The method can be and has been applied to impellers with blades of arbitrary shape, as distinguished from analytical methods which can be applied directly only to blades of special shape (1).


1963 ◽  
Vol 14 (2) ◽  
pp. 105-124 ◽  
Author(s):  
Derek F. Lawden

SummaryThe development during the last two decades of analytical techniques for the solution of problems relating to the optimisation of rocket trajectories is outlined and the present position in this field of research is summarised. It is shown that the determination of optimal trajectories in a general gravitational field can be expressed as a Mayer problem from the calculus of variations. The known solution to such a problem is stated and applied, first to the special case of the launching of an artificial satellite into a circular orbit with minimum expenditure of propellant and, secondly, to the general astronautical problem of the economical transfer of a rocket between two terminals in a gravitational field. The special cases when the field is uniform and when it obeys an inverse square law of attraction to a point are then considered, and the paper concludes with some remarks concerning areas in which further investigations are necessary.


1988 ◽  
Vol 41 (3) ◽  
pp. 469
Author(s):  
HJ Juretschke ◽  
HK Wagenfeld

Unless special precautions are taken, the experimental determination of two-beam structure factors to better than 1 % may include contributions from neighbouring n-beam interactions. In any particular experimental configuration, corrections for such contributions are easily carried out using the modified two-beam structure factor formalism developed recently (Juretschke 1984), once the full indexing of the pertinent n-beam interactions is known. The method is illustrated for both weak and strong primary reflections and its applicability in special cases, as well as for less than perfect crystals, is discussed.


1984 ◽  
Vol 80 ◽  
pp. 199-227
Author(s):  
C. De Loore

AbstractComparison of the characteristics of groups of stars in various evolutionary phases and the study of individual systems allow to make estimates of the parameters governing mass loss and mass transfer. Observations enable us in a few cases to determine geometric models for binaries during or after the mass transfer phase (disks, rings, common envelopes, symbiotics, interacting binaries, compact components).From spectra taken at different phases, radial velocity curves can be derived and masses and radii can be determined. In special cases spectra in different spectral ranges (visual, UV, X-ray) are required for the determination of the radial velocities of the two components (for X-ray binaries, for systems with hot and cool components). Information on parameters related to the mass transfer process enables us to consider non conservative evolution - i.e. the computation of evolutionary sequences with the assumption that mass and angular momentum not only are transferred from one of the components towards the other one, but that also mass and angular momentum can leave the system. Careful and detailed analysis of the observations allows in certain cases to determine the parameters governing this mass and angular momentum loss, and for contact phases, to determine the degree of contact.


In previous papers of this series the problem of energy interchange between a gas atom and a solid has been discussed for the case when the gas atom makes a transition between two adsorbed states or between an adsorbed state and a free state. In this paper we shall discuss the case of a transition between two free states and apply the results to the determination of the thermal accommodation coefficient. In recent years a number of theoretical papers on this subject have appeared, following the new and accurate experimental work of Roberts, who worked with helium and neon on tungsten. The authors, however, neglect, or only roughly take into account, the attractive field which is known to exist between the solid and the gas; the fact that atoms become adsorbed on the surface is clear evidence of the existence of such a field. In this paper we shall suppose that the interaction potentials between solid and gas atom can be represented by a Morse potential function, for it has the right characteristics; in that it is attractive at large distances and repulsive at small ones, and has a minimum in between. The formulae of this paper are accordingly more general than previous ones and contain them as special cases. They are applicable to experimental results such as those of neon on tungsten for which earlier theories would not be adequate.


1975 ◽  
Vol 30 (1-2) ◽  
pp. 88-90 ◽  
Author(s):  
Kuno Kirschfeld ◽  
M. Lindauer ◽  
H. Martin

Abstract It is shown that the knowledge of the E-vector direction of the linearly polarized light at any point of the sky alone is insufficient for the determination of the position of the sun. If the E-vector direction of a second point is not known the knowledge of at least one other parameter is necessary. This parameter might be the height of the sun over the horizon. With the knowledge of the height the infinite number of solutions for the sun’s position becomes reduced to two, or in special cases to one. These cases are derived.


2020 ◽  
Vol 66 (257) ◽  
pp. 447-456 ◽  
Author(s):  
Heinz W. Gäggeler ◽  
Leonhard Tobler ◽  
Margit Schwikowski ◽  
Theo M. Jenk

Abstract210Pb is an environmental radionuclide with a half-life of 22.3 years, formed in the atmosphere via radioactive decay of radon (222Rn). 222Rn itself is a noble gas with a half-life of 3.8 days and is formed via radioactive decay of uranium (238U) contained in the Earth crust from where it constantly emanates into the atmosphere. 210Pb atoms attach to aerosol particles, which are then deposited on glaciers via scavenging with fresh snow. Due to its half-life, ice cores can be dated with this radionuclide over roughly one century, depending on the initial 210Pb activity concentration. Optimum 210Pb dating is achieved for cold glaciers with no – or little – influence by percolating meltwater. This paper presents an overview which not only includes dating of cold glaciers but also some special cases of 210Pb applications in glaciology addressing temperate glaciers, glaciers with negative mass balance, sublimation processes on glaciers in arid regions, determination of annual net snow accumulation as well as glacier flow rates.


1991 ◽  
Vol 70 (3) ◽  
pp. 221-224
Author(s):  
L. Ya. Grona ◽  
V. M. Gul'ko ◽  
N. F. Kolomiets ◽  
A. E. Shikanov
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