Stress fields of certain nonequilibrium dislocation aggregates. part 2. Dislocation ?walls,? bent with a constant radius of curvature

1981 ◽  
Vol 13 (5) ◽  
pp. 656-659
Author(s):  
E. �. Zasimchuk ◽  
S. I. Selitser ◽  
I. M. Fodchuk
Keyword(s):  
Stress Fields ◽  
Radius Of Curvature ◽  
Constant Radius ◽  
Dislocation Walls

Condensation on a Downward-facing Horizontal Rippled Surface

1972 ◽  
Vol 94 (3) ◽  
pp. 315-320 ◽  
Author(s):  
Avram Markowitz ◽  
B. B. Mikic ◽  
A. E. Bergles
Keyword(s):  
Experimental Data ◽  
Small Diameter ◽  
Horizontal Cylinder ◽  
Analytical Investigation ◽  
Film Condensation ◽  
Radius Of Curvature ◽  
Condensation Rate ◽  
Projected Area ◽  
Condensate Film ◽  
Constant Radius

An analytical investigation is presented for film condensation on a downward-facing horizontal doubly rippled surface. Small undulations having constant radius of curvature are combined with larger cylindrical grooves designed to aid condensate runoff. A direct expression for the condensate film thickness at the top of an undulation crest, as well as on a small-diameter horizontal cylinder, is derived. An upper-bound expression for the condensation rate on the rippled surface is then obtained which predicts that the condensation rate will be five times the rate attainable on a flat horizontal surface of the same projected area. This analytical expression is compared with experimental data.

Stress fields of tilted dislocation walls

1998 ◽  
Vol 11 (4) ◽  
pp. 270-276 ◽  
Author(s):  
R. Sedláček ◽  
M. Hecker
Keyword(s):  
Stress Fields ◽  
Dislocation Walls

Generalized LP_1m modes in an optical fiber with constant radius of curvature

1998 ◽  
Vol 37 (3) ◽  
pp. 463
Author(s):  
Kiyonobu Kusano ◽  
Adrian Ankiewicz
Keyword(s):  
Optical Fiber ◽  
Radius Of Curvature ◽  
Constant Radius

Kinematics and Control of the TowPlow: A Steerable Articulated Vehicle System

2014 ◽  
Author(s):  
Jaeyoung Kang ◽  
Steven A. Velinsky
Keyword(s):  
Kinematic Analysis ◽  
Radius Of Curvature ◽  
Steering Angle ◽  
Vehicle System ◽  
Kinematic Characteristics ◽  
Articulated Vehicle ◽  
Constant Radius ◽  
Simulation Results ◽  
And Control

The TowPlow is a novel type of snowplow that consists of a conventional snowplow vehicle and a steerable, plow-mounted trailer. The trailer is equipped with hydraulic-powered steerable axles so that it can be steered up to 30 degrees with respect to the tractor. The combination of the front plow of the towing snowplow and the trailer-equipped plow is able to clear a path up to approximately 24-ft wide, which is the width of two typical traffic lanes. In this paper, the kinematic characteristics of the TowPlow are derived using instantaneous centers of velocity. Based on the derived equations, the relation between the radius of curvature and the trailer wheel steering angle that allows the tractor-trailer to maintain its initial articulation angle is defined. Also, simulations of constant radius turning are performed with and without the trailer’s corrective steering, and the results are compared. Even though the kinematic analysis does not take forces and inertia into account, it is clearly demonstrated in the simulation results that appropriate steering of the trailer wheel is necessary to maintain the articulation angle of the TowPlow and to prevent the device from intruding into adjacent lanes.

scholarly journals The Equilibrium Condition of a Non-Thin Screw Wedge-Shaped Twin Located in the Distance from the Surface of an Undeformed Crystal

2018 ◽  
Vol 17 (6) ◽  
pp. 515-520
Author(s):  
Yu. V. Vasilevich ◽  
O. M. Ostrikov
Keyword(s):  
Shape Memory ◽  
Elasticity Theory ◽  
Equilibrium Condition ◽  
Continuous Distribution ◽  
Stress Fields ◽  
Twin Boundaries ◽  
Solution Of Equations ◽  
Shape Memory Materials ◽  
Twinning Direction ◽  
Dislocation Walls

The equilibrium condition for a non-thin helical wedge-shaped twin located far from the surface of the crystal is obtained. The case of an undeformed solid is considered. It is established that under such conditions a helical twin can not twin can not exist under such conditions. The result is in full conformity with generally known results for dislocation walls from helical dislocations. An approximation for continuous distribution of twinning dislocations at twin boundaries has been used in methodology for deriving an equilibrium condition. The shape of the twin boundaries has been described by functions that depend on density of the twinning dislocations at the twin boundaries. It has been assumed that the forces acting on the twin boundaries from the side of the twin dislocations are equal to zero. One degree of freedom along a twinning direction has been presupposed for twinning dislocations. Dislocation creeping effects have been excluded in the model. A calculation of stress fields for a twin has been carried out within the framework of an elasticity theory. In this case a superposition of stresses from each twin boundary has been considered. The solution of equations has been sought in the form of a polynomial. A linear approximation of such solution is considered in detail. The ем resulting equilibrium condition is satisfied for two values equal to zero that is a twin length and its width at the mouth. The result is important in the field of mechanics for twinning materials, shape memory materials, and in the development of techniques for predicting destruction and functioning of twinning materials.

Micropuncture measurement of alveolar liquid pressure in excised dog lung lobes

1987 ◽  
Vol 62 (2) ◽  
pp. 781-784 ◽  
Author(s):  
J. U. Raj ◽  
R. L. Conhaim ◽  
J. Bhattacharya
Keyword(s):  
Laplace Equation ◽  
Constant Pressure ◽  
Liquid Interface ◽  
Liquid Volume ◽  
Radius Of Curvature ◽  
Liquid Pressure ◽  
Constant Radius ◽  
Air Liquid Interface ◽  
Lung Lobes ◽  
Alveolar Liquid

We have investigated the mechanism of alveolar liquid filling in pulmonary edema. We excised, degassed, and intrabronchially filled 14 dog lung lobes from nine dogs with 75, 150, 225, or 350 ml of 5% albumin solution, and then air inflated the lobes to a constant airway pressure of 25 cmH2O. By use of micropipettes, we punctured subpleural alveoli to measure alveolar liquid pressure by the servo-null technique. Alveolar liquid pressure was constant in all lobes despite differences in lobe liquid volume and averaged 10.6 +/- 1.3 cmH2O. Thus, in all lobes a constant pressure drop of 14.4 cmH2O existed from airway to alveolar liquid across the air-liquid interface. We attribute this finding, on the basis of the Laplace equation, to an air-liquid interface of constant radius in all the lobes. In fact, we calculated from the Laplace equation an air-liquid interface radius which equalled morphological estimates of alveolar radius. We conclude that in the steady state, alveoli that contained liquid have a constant radius of curvature of the air-liquid interface possibly because they are always completely liquid filled.

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