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Effective charge mass for thin charges - a 60° cone. The basic Gurney equations for flat sheets assume that the sheet of material is a large diameter. Small explosive charges, where the explosive's diameter is not significantly larger than its thickness, have reduced effectiveness as gas and energy are lost to the sides. [1]
A partially disassembled Curta calculator, showing the digit slides and the stepped drum behind them Curta Type I calculator, top view Curta Type I calculator, bottom view. The Curta is a hand-held mechanical calculator designed by Curt Herzstark. [1] It is known for its extremely compact design: a small cylinder that fits in the palm of the hand.
Barring detailed mass determinations, [4] the mass can be estimated from the diameter and assumed density values worked out as below. = Besides these estimations, masses can be obtained for the larger asteroids by solving for the perturbations they cause in each other's orbits, [5] or when the asteroid has an orbiting companion of known orbital radius.
Mass flow rate is defined by the limit [3] [4] ˙ = =, i.e., the flow of mass through a surface per time .. The overdot on ˙ is Newton's notation for a time derivative.Since mass is a scalar quantity, the mass flow rate (the time derivative of mass) is also a scalar quantity.
For the thin-walled assumption to be valid, the vessel must have a wall thickness of no more than about one-tenth (often cited as Diameter / t > 20) of its radius. [4] This allows for treating the wall as a surface, and subsequently using the Young–Laplace equation for estimating the hoop stress created by an internal pressure on a thin-walled cylindrical pressure vessel:
Optimal packing fraction for hard spheres of diameter inside a cylinder of diameter . Columnar structures arise naturally in the context of dense hard sphere packings inside a cylinder. Mughal et al. studied such packings using simulated annealing up to the diameter ratio of D / d = 2.873 {\textstyle D/d=2.873} for cylinder diameter D ...
The definitions and results in this section are taken from the 1913 text Plane and Solid Geometry by George A. Wentworth and David Eugene Smith (Wentworth & Smith 1913).. A cylindrical surface is a surface consisting of all the points on all the lines which are parallel to a given line and which pass through a fixed plane curve in a plane not parallel to the given line.
In 1948 the cylindrical Curta calculator, which was compact enough to be held in one hand, was introduced after being developed by Curt Herzstark in 1938. This was an extreme development of the stepped-gear calculating mechanism. It subtracted by adding complements; between the teeth for addition were teeth for subtraction.