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The gridded ion thruster is a common design for ion thrusters, a highly efficient low-thrust spacecraft propulsion method running on electrical power by using high-voltage grid electrodes to accelerate ions with electrostatic forces.
Grid erosion cannot be avoided and is the major lifetime-limiting factor. Thorough grid design and material selection enable lifetimes of 20,000 hours or more. A test of the NASA Solar Technology Application Readiness (NSTAR) electrostatic ion thruster resulted in 30,472 hours (roughly 3.5 years) of continuous thrust at maximum power.
The grid file contains the coordinates of the solution grid, while the solution file contains information typical of a CFD solution, flow density, flow momentum (a vector), and flow energy. [2] Data may be stored in either binary or ASCII text format and floating point values may be either single or double precision.
The data below tabulates standard electrode potentials (E°), in volts relative to the standard hydrogen electrode (SHE), at: Temperature 298.15 K (25.00 °C; 77.00 °F); Effective concentration (activity) 1 mol/L for each aqueous or amalgamated (mercury-alloyed) species; Unit activity for each solvent and pure solid or liquid species; and
Electrons hitting the grid produce X-rays that produce photoelectric noise in the ion collector. This limits the range of older hot-cathode gauges to 10 −8 Torr and the Bayard–Alpert gauges to about 10 −10 Torr. Additional wires at cathode potential in the line of sight between the ion collector and the grid prevent this effect.
From January 2008 to March 2011, if you bought shares in companies when Lucille S. Salhany joined the board, and sold them when she left, you would have a -16.7 percent return on your investment, compared to a -11.6 percent return from the S&P 500.
From January 2008 to December 2012, if you bought shares in companies when Michael J. Long joined the board, and sold them when he left, you would have a 94.1 percent return on your investment, compared to a -2.8 percent return from the S&P 500.
A pivot table field list is provided to the user which lists all the column headers present in the data. For instance, if a table represents sales data of a company, it might include Date of sale, Sales person, Item sold, Color of item, Units sold, Per unit price, and Total price. This makes the data more readily accessible.