Monthly Archive: July 2018

Jul 25

Chemical bonds simulated with quantum computers!

“Quantum chemistry is the science of understanding the complicated bonds and reactions of molecules using quantum mechanics. The ‘moving parts’ of anything but the most-simple chemical processes are beyond the capacity of the biggest and fastest supercomputers. By modelling and understanding these processes using quantum computers, scientists expect to unlock lower-energy pathways for chemical reactions, …

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Jul 22

Acceleration with stars

His idea is that an advanced civilization could build a sphere that emits waste radiation in a specific direction. This radiation would accelerate the sphere—and the star it contains—in the opposite direction.” I’m not sure about the process of building a sphere around ‘stars’, but the idea is very exciting. However, comparing the whole universe, …

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Jul 19

Family tree :)

Here is my collage of powerpuffs with acrylic paints. This is a gift for my family 🙂 I’ve used this website: https://powerpuffyourself.com/#!/en

Jul 19

Stabilizing fusion plasmas

Sawtooth swings—up-and-down ripples found in everything from stock prices on Wall Street to ocean waves—occur periodically in the temperature and density of the plasma that fuels fusion reactions in doughnut-shaped facilities called tokamaks. These swings can sometimes combine with other instabilities in the plasma to produce a perfect storm that halts the reactions. However, some …

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Jul 15

Surface-bound hydrogen: diffusion > desorption

Wait! What? “The first step in hydrogen storage is chemisorption, wherein gaseous H2 collides with Pd and adsorbs (sticks) to the surface. Secondly, the chemisorbed H atoms diffuse into the sub-surface, several nanometers deep.” Why gold-palladium alloys are better than palladium for hydrogen storage

Jul 14

Improvizing a history

If you’re willing to listen some Turkish music, here we go! This song means a lot to me but also it is hard to explain. To me, it is about the changes happening without our intervention or will. I’ve played this song many times so I have tons of versions of the same song. Soft …

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Jul 14

Review: UNIQUE SOLUTIONS TO BOUNDARY VALUE PROBLEMS IN THE COLD PLASMA MODEL

In this article, Otway provides a solution to the closed Dirichlet problem which is a mixed eliptic-hyperbolic equation. This type of equations are encountered in electromagnetic wave propagation in cold plasmas. The equation in the model for electromagnetic wave propagation in zero-temperature plasma is: (x-y^2)u_{xx}+u_{yy}+\kappa u_{x}=0 where u(x,y) is twice-continuously differentiable function. This is a …

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Jul 14

Experimental Study of the Effects of the Cathode Position and the Electrical Circuit Configuration on the Operation of HK40 Hall Thruster and BUSTLab Hollow Cathode

HK40 Hall thruster, designed and developed at the Bogazici University Space Technologies Laboratory (BUSTLab), is an SPT type Hall thruster with a 40 mm discharge channel. HK40 was initially designed to operate with SmCo permanent magnets. To optimize the magnetic field topology, the permanent magnets were replaced with iron-core electromagnets. The thruster is operated with …

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Jul 14

Experimental Investigation of the Effects of Cathode Current on HK40 Hall Thruster Operation

Hall effect thrusters utilize electric and magnetic fields to extract ions from a plasma discharge. The cathode is responsible for the ionization of the propellant and the neutralization of the ion beam by emitting an equal number of electrons to prevent spacecraft charging. Hollow cathode electrons are extracted from LaB6 insert surface by thermionic emission. …

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Jul 14

Investigation of the Effect of Hollow Cathode Neutralizer Location on Hall Effect Thruster Efficiency

Neutralization of ions is important for all electric thruster types when considering thruster efficiency and life. Hollow cathode is responsible for both creating plasma discharge and neutralization of the beam ions for Hall Effect Thruster (HET). In this study, appropriate placement of the cathode is investigated by taking into account that the decrease in cathode …

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