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Prentice's rule, named so after the optician Charles F. Prentice, is a formula used to determine the amount of induced prism in a lens: = where: P is the amount of prism correction (in prism dioptres) c is decentration (the distance between the pupil centre and the lens's optical centre, in millimetres)
Maddox wing. The Maddox Wing is an instrument utilized by ophthalmologists, orthoptists and optometrists in the measurement of strabismus (misalignment of the eyes; commonly referred to as a squint or lazy eye by the lay person). It is a quantitative and subjective method of measuring the size of a strabismic deviation by dissociation of the ...
The small-disturbance potential equation then transforms to the Laplace equation, ϕ ¯ x ¯ x ¯ + ϕ ¯ y ¯ y ¯ + ϕ ¯ z ¯ z ¯ = 0 (in flow field) {\displaystyle {\bar {\phi }}_{{\bar {x}}{\bar {x}}}+{\bar {\phi }}_{{\bar {y}}{\bar {y}}}+{\bar {\phi }}_{{\bar {z}}{\bar {z}}}=0\quad {\mbox{(in flow field)}}}
Description. Mathematically, such a calculation can be expressed: The bolometric correction for a range of stars with different spectral types and groups is shown in the following table: [1] [2] [3] The bolometric correction is large and negative both for early type (hot) stars and for late type (cool) stars.
The Prentice position is an orientation of a prism, used in optics, optometry and ophthalmology. In this position, named after the optician Charles F. Prentice, the prism is oriented such that light enters it at an angle of 90° to the first surface, so that the beam does not refract at that surface. All the deviation caused by the prism takes ...
Pressure-correction method is a class of methods used in computational fluid dynamics for numerically solving the Navier-Stokes equations normally for incompressible flows. Common properties [ edit ] The equations solved in this approach arise from the implicit time integration of the incompressible Navier–Stokes equations .
Esophoria is an eye condition involving inward deviation of the eye, usually due to extra-ocular muscle imbalance. It is a type of heterophoria. Cause. Causes include: Refractive errors; Divergence insufficiency; Convergence excess; this can be due to nerve, muscle, congenital or mechanical anomalies.
Most charts or tables indicate the type of friction factor, or at least provide the formula for the friction factor with laminar flow. If the formula for laminar flow is f = 16 / Re, it is the Fanning factor f, and if the formula for laminar flow is f D = 64 / Re, it is the Darcy–Weisbach factor f D.
The free air correction is calculated from Newton's Law, as a rate of change of gravity with distance: g = G M R 2 d g d R = − 2 G M R 3 = − 2 g R {\displaystyle {\begin{aligned}g&={\frac {GM}{R^{2}}}\\{\frac {dg}{dR}}&=-{\frac {2GM}{R^{3}}}=-{\frac {2g}{R}}\end{aligned}}}
For a flat, horizontal reflector, the traveltime equation is: t 2 = t 0 2 + x 2 v 2 {\displaystyle t^{2}=t_{0}^{2}+{\frac {x^{2}}{v^{2}}}} where x = offset; v = velocity of the medium above the reflecting interface; t 0 {\displaystyle t_{0}} = travel time at zero offset, when the source and receiver are in the same place.