Cylinder Hole Research Articles

Open orbits in Hg3-δAsF6

Open orbits in the linear-chain mercury compound Hg3- delta AsF6 were investigated by the induced torque method at a temperature of 1.3K with magnetic fields up to 8.5 T. There is a primary open orbit in the (001) direction for all field directions in the (001) plane. It runs along electron and hole Fermi surface cylinders directed parallel to the direction kc. There are also open orbits in (01n) directions where n>or=2. They result from magnetic breakthrough with a breakdown field of approximately 6.6 T between electron and hole cylinders. The results confirm the Fermi surface model formed from one-dimensional bands and show that there is a variation in the separation of electron and hole cylinders along the direction kc.

Stresses at offset-oblique holes in thick-walled cylinders subjected to torsional loading

The paper describes a three-dimensional photoelastic analysis of a series of Araldite models, each containing five or six different offset-oblique holes positioned in such a way that there were no ‘interaction’ effects between neighbouring holes. The geometric parameters defining a hole were varied systematically and the elastic stress distribution around the outer edge of each hole was obtained. The stress data are presented in non-dimensional form in terms of the shear stress in a plain cylinder. The dependence of the maximum stress on the geometric variables is discussed and it is shown that the stress concentrations for a wide range of hole/cylinder parameters can be reasonably well predicted from flat plate data. In some cases the predictions are unconservative.

A procedure for producing smooth bore holes in copper cylinders

An extremely simple and inexpensive technique by which holes of uniform bore can be produced in copper is described. Measured uniformity may exceed 2500 Å on a bore diameter of 6.35 mm.

Deformation of a Laminated Cylindrical Rotor

This paper describes the behavior of slip, force transmission mechanism and deformation of a laminated cylindrical rotor composed of segmental sheets under circumferential tensile force caused by centrifugal force. Experimental and theoretical investigations have been made and the results of experiments on slip between the sheets and deformation of cylinder have been consistent with the theory. Dimensions and arrangement of the segmental sheets, tightening pressure of the laminated cylinder and tightening-bolt holes in the sheets have effects on the behavior of slip and deformation of the laminated cylinder, and these effects are herein discussed.

INFLUENCE OF YIELD ON CALCIUM CONTENT OF MECHANICALLY DEBONED LAMB AND MUTTON

Mutton carcasses and lamb carcass cuts were mechanically deboned at different settings to give variable yields of mechanically deboned meat. Higher yields of mechanically deboned meat were related to higher calcium and fat percentages. Lamb breasts had the lowest bone percentage of any of the cuts and the mechanically deboned meat from breasts had the lowest calcium content when compared to deboned meat from other lamb cuts or mutton carcasses. Necks had the highest bone percentage and the highest calcium content in the mechanically deboned meat. Data are presented which show that mechanically deboned meat is not homogenous as it is extruded from the cylinder. Palatability of bologna made with mechanically deboned meat increased as the size of cylinder holes through which the meat was extruded decreased.

Sur les observations de maree clinometrique dans un long tunnel

Two clinometric stations, 30 meters apart, have been established, belowa coverage of 600 meters, in a rectilinear gallery (unfinished railway tunnel, azimuth N 70°E, 4 kilometers length, nearly cylindrical section, 10 meters diameter) bored in the southern part of the crystalline Vosges (France). The reconstitution of the vertical deflections gives, at both stations, for the principal waves, exceptionally flattened ellipses whose great axis lie very near the direction of the tunnel. One obtains, for example, for λ(M2), 0,920 in the axis of the tunnel and 0.485 in the perpendicular direction. An interpretation of this phenomena is tried by considering the geometrical deformations near the hole cylinder constituted by the gallery under the influence of the tide-generating potential. The computation on a twodimensional model shows that the effect of the tunnel is negligible.

Energetic Stability of Persistent Currents in a Long Hollow Cylinder

This paper represents an extension of the work of Schafroth in which the carriers of electricity in a superconductor are assumed to constitute an ideal Bose gas. The long-range electromagnetic interactions are fully taken into account by the method of the self-consistent field. The corresponding general equations are obtained from a variational principle applied to the total energy of the system, and the change of the total energy due to individual particle transitions is considered. Axially symmetric solutions are found for the geometry of a long hollow cylinder and for the case in which all particles are in the same lowest single-particle level compatible with the angular momentum ${l}^{\ensuremath{'}}\ensuremath{\hbar}$ around the cylinder axis. This case represents a state of the system in which ${l}^{\ensuremath{'}}$ flux quanta are trapped in the cylinder. Assuming the lattice to be at $T=0$, such a state will be stable against single-particle transitions if the corresponding energy change of the system is positive. This state need not be the state of lowest energy, but it would have a practically infinite lifetime if the stability criterion against single-particle transitions is satisfied. Indeed, its energy could only be lowered by a simultaneous transition of a number of particles comparable to their total number, which would be an extremely rare event. It is shown that stability depends on the fields ${H}_{1}$ and ${H}_{2}$ in the cylinder hole and outside the cylinder, respectively. For ${H}_{1}={H}_{2}$, stability requires that these fields be less than ${H}^{*}=4\ensuremath{\pi}n{\ensuremath{\mu}}_{0}$, where $n$ is the density of the bosons and ${\ensuremath{\mu}}_{0}$ is the Bohr magneton. For ${H}_{2}=0$, it requires that ${H}_{1}<{({H}_{c})}_{T}$ where ${({H}_{c})}_{T}$ depends upon the hole radius ${r}_{1}$ and the wall thickness $d$. For $d\ensuremath{\gg}{r}_{1}$, one finds ${({H}_{c})}_{T}={H}^{*}$, while for $d\ensuremath{\ll}{r}_{1}$, one has ${({H}_{c})}_{T}=(\frac{d}{{r}_{1}}){H}^{*}$. The difference between ${({H}_{c})}_{T}$ and ${H}^{*}$ for $d\ensuremath{\ll}{r}_{1}$ is further investigated, and it is shown that the case for which ${H}^{*}>{H}_{1}>{({H}_{c})}_{T}$ may nevertheless experimentally appear to be stable since the stability conditions are strongly modified considering that the transfer of very small but finite amounts of energy to the lattice may not occur during the time of a measurement.

Stress Concentration in Heavy-Walled Cylindrical Pressure Vessels - Effect of Elliptic and Circular Side Holes

This work was done to establish realistic stress concentration factors for side holes in cylinders. Contrary to intuitive reasoning, the circumferential stress at the cylinder bore-circular side hole interface is intensified by a factor less than 3.0. These factors for both elliptic and circular side holes approach a maximum with increasing ratio of outside to inside diameter of the cylinder and with decreasing size of the side hole; elliptic holes give rise to stress concentrations at the critical location, less than those induced by the presence of circular holes. The practical significance of the results lies in the fact that realistic stress concentration factors can be determined, so that overdesign is avoided. Some vessels heretofore considered impractical can be used with elliptic rather than circular side holes. (auth)

On the inductance of iron-cored coils

The magnetic field in the neighbourhood of coils threaded through holes in iron cylinders is calculated. The results are relevant to the estimation of the self-inductance of rotating machines and transformers and form the basis for an examination of the soundness of approximate formulae used in the design of such apparatus.