The Dual-Stage 4-Grid (DS4G) is an electrostatic ion thruster design developed by the European Space Agency, in collaboration with the Australian National University. The design was derived by D. Fern from Controlled Thermonuclear Reactor experiments that use a 4-grid mechanism to accelerate ion beams. A 4-grid ion thruster with only 0.2 m diameter is projected to absorb 250 kW power. With that energy input rate, the thruster could produce a thrust of 2.5 N. The specific impulse (a measure of fuel efficiency), could reach 19,300 s at an exhaust velocity of 210 km/s if xenon propellant was used. The potentially attainable power and thrust densities would substantially extend the power absorption of current ion thrusters to far more than 100 kW. These characteristics facilitate the development of ion thrusters that can result in extraordinary high-end velocities. Like with thruster concepts such as VASIMR, the dual-stage-4-grid ion thrusters are mainly limited by the necessary power supply for their operation. For example, if solar panels were to supply more than 250 kW, the size of the solar array would surpass the size of the solar panels of the International Space Station. To provide 250 kW with Stirling radioisotope generators would require roughly 17 tonnes of plutonium-238 (for which the US stockpile as of 2013 was no more than 20 kg), and so a nuclear thermal reactor would be needed. (Wikipedia).
Using a set of points determine if the figure is a parallelogram using the midpoint formula
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determining if a set of points makes a parallelogram or not
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determine if a set of points is a parallelogram using the distance formula
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determine if a set of points is a trapezoid or not
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Using the slope formula to determine if points make up a rectangle
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determine if a set of points is a parallelogram by using the slope formula
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determining if a set of points is a rhombus, square or rectangle
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Determine if a set of points makes up a rectangle using the distance formula
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
How to determine if a set of points makes up a rectangle using the distance formula
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Arduino Based Low Voltage Vacuum Tube Tester
In this episode we take a stab at building a vacuum tube tester that gives us some proper, usable data! Granted, itβs all at super low voltages, just 24V in this case, but that actually works out perfectly for the types of circuits that we commonly build. Most importantly though, this was
From playlist Vacuum Tube Logic
Water-boiling IEC fusion reactor (fusor) w/magnetic bottling
Here is a short video of our fusor running at full power. For those interested, here are the specs: Powered by: 25kVDC-30kVDC from a ~400W ZVS-driven flyback transformer. Current in excess of 20mA (estimated). Chamber/pressure: steel vacuum chamber from Amazon.com. Pumped down to below 100
From playlist LabCoatz Shorts
Percolation: a Mathematical Phase Transition
βββββSOURCESββββββββββββββββββββββββ Percolation β BΓ©la BollobΓ‘s and Oliver Riordan Cambridge University Press, New York, 2006. Sixty Years of Percolation β Hugo Duminil-Copin https://www.ihes.fr/~duminil/publi/2018ICM.pdf Percolation β Geoffrey Grimmett volume 321 of Grundlehren der Ma
From playlist Prob and Stats
Convex Set Disjointness, Distributed Learning of Halfspaces, and Linear Programming - Shay Moran
Computer Science/Discrete Mathematics Seminar II Topic: Convex Set Disjointness, Distributed Learning of Halfspaces, and Linear Programming Speaker: Shay Moran Affiliation: Member, School of Mathematics Date: May 12, 2020 For more video please visit http://video.ias.edu
From playlist Mathematics
Letβs Build a Low Voltage Vacuum Tube Audio Amplifier
In this episode, we step out of our comfort zone and see if we can build a functioning vacuum tube audio amplifier running at low and safe voltages. Spoiler alert, we do! Also, weβre now on Discord, Reddit and Twitter, so join us! Discord: https://discord.gg/p7UsfHD Reddit: https://www.
From playlist Audio Projects
Zhongyang Li: "XOR Ising model and constrained percolation"
Asymptotic Algebraic Combinatorics 2020 "XOR Ising model and constrained percolation" Zhongyang Li - University of Connecticut Abstract: I will discuss the percolation properties of the critical and non-critical XOR Ising models in the 2D Euclidean plane and in the hyperbolic plane, whos
From playlist Asymptotic Algebraic Combinatorics 2020
Choiceless Polynomial Time - Ben Rossman
Computer Science/Discrete Mathematics Seminar I Topic: Choiceless Polynomial Time Speaker: Ben Rossman Affiliation: University of Toronto Date: October 14, 2019 For more video please visit http://video.ias.edu
From playlist Mathematics
Red Plating Vacuum Tubes to Destruction!
In this episode we have a bit of a laugh and try to destroy some vacuum tubes. Red plating is when thereβs a problem in the circuit and too much current is trying to force its way through the tube. The electrons start to smash into the plate and it gets hot, ultimately glowing red. This ca
From playlist Vacuum Tube Logic
How to determine if points are a rhombus, square or rectangle
π Learn how to determine the figure given four points. A quadrilateral is a polygon with four sides. Some of the types of quadrilaterals are: parallelogram, square, rectangle, rhombus, kite, trapezoid, etc. Each of the types of quadrilateral has its properties. Given four points that repr
From playlist Quadrilaterals on a Coordinate Plane
Jean-Yves Welschinger: Expected topology of a random subcomplex in a simplicial complex
Abstract: I will explain how to bound from above and below the expected Betti numbers of a random subcomplex in a simplicial complex and get asymptotic results under infinitely many barycentric subdivisions. This is a joint work with Nermin Salepci. It complements previous joint works with
From playlist Probability and Statistics