CRITERIA EVALUATION OF THE LIMIT DEPTH OF HORIZONTAL PRODUCTION

The paper presents the results of a study to determine the technological contours of horizontal underground workings and the maximum safe depth of their laying. The criterion for determining the limiting depth can be the condition that there are no points on the output circuit at which the stresses the tangential normal stress exceeds the tensile and compressive strengths of the host rock. The results of solving the problem of finding fracture zones on a circular cross-section working circuit are in satisfactory qualitative agreement with the result obtained independently of the authors.

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The hydrodynamics of non-Newtonian fluids. II

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004100000463 ◽

1949 ◽

Vol 45 (1) ◽

pp. 88-91 ◽

Cited By ~ 25

Author(s):

R. S. Rivlin

Keyword(s):

Normal Stress ◽

Cross Section ◽

Pressure Difference ◽

Circular Cross Section ◽

Newtonian Fluids ◽

Hydrodynamic Theory ◽

Stress Components ◽

The Absolute

In this paper, the general hydrodynamic theory of visco-inelastic, incompressible, non-Newtonian fluids, developed in a previous paper (l), is applied to the problem of the flow of such a fluid through a tube of circular cross-section. It is found that the absolute values of the normal stress components are no longer uniform over a cross-section of the tube normal to its axis, as in the case of Newtonian fluids obeying the laws of classical hydrodynamics.However, the pressure difference, between points at equal radii on two planes normal to the axis, is independent of the position of these points on the planes.

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SAF file: It's really three dimensional file

Mustansiria Dental Journal ◽

10.32828/mdj.v14i1.744 ◽

2018 ◽

Vol 14 (1) ◽

pp. 1

Author(s):

Prof. Dr. Jamal Aziz Mehdi

Keyword(s):

Cross Section ◽

Root Canal ◽

Three Dimensional ◽

Circular Cross Section ◽

Circular Motion ◽

Root Canal Treatment ◽

Metal Core ◽

Rotating Blade

The biological objectives of root canal treatment have not changed over the recentdecades, but the methods to attain these goals have been greatly modified. Theintroduction of NiTi rotary files represents a major leap in the development ofendodontic instruments, with a wide variety of sophisticated instruments presentlyavailable (1, 2).Whatever their modification or improvement, all of these instruments have onething in common: they consist of a metal core with some type of rotating blade thatmachines the canal with a circular motion using flutes to carry the dentin chips anddebris coronally. Consequently, all rotary NiTi files will machine the root canal to acylindrical bore with a circular cross-section if the clinician applies them in a strictboring manner

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