Dec 17

Seminar notes: Is Hydrodynamics Relevant to the Origin of Life?

We are attending at least 8 seminars for every semester. Here is a short summary of the most interesting one!

This was an interesting talk mostly focused on the bubbles formed in ocean and relating those
with the origin of life. The speaker mentioned the mechanical forces created by waves in
ocean and pointed out that his group is solving a kind of hydrodynamics problem in a tube.
This tube can be any organic material can be found in ocean. They chose DNA nanotubes
because these are easy to obtain in lab. Then, they studied hydrodynamic shear on bursting
bubbles after breaking of the waves. His group measured and calculated shear and flow rate
inside DNA nanotubes in bubble foams and they found due to the high flow rates inside these
tubes, elongation of the tubes can cause fragmentation which can drive the production of new
molecules.

Speaker: Rizal Hariadi 

Oct 21

I didn’t know graphene is so newly discovered!

Ok, it’s my ignorance. History time ! Year: 2004 Location: The University of Manchester Nobel Physics: 2010

Here is the whole story and information from ‘the home of graphene‘, Manchester.

Scotch Tape

Sep 01

Science policy is giving rise to open science or a new form of capitalism?

Here is a provocative paper recently published. I will add my thoughts when I’m done with reading.

 

http://journals.sagepub.com/doi/abs/10.1177/0306312718772086

Aug 29

Notes from iPlasmaNano 2018

It was a really dense conference. Mostly, the professors gave talks about the latest updates of their research. The discussions were at high level. I tried to keep my eyes open to follow almost every talk 🙂 But, it’s worth it 🙂 Here are the topics attracting my attention.

 

 

Nano particle synthesis: https://scholar.google.com/citations?user=ni1mqkEAAAAJ&hl=en

–>in-situ FTIR:plasma-nano particle interaction

Graphite (anode–>mix with catalyst), BN nanotube synthesis by arc: https://scholar.google.com/citations?user=-PkzDBQAAAAJ&hl=en

–>B mix with metal (Ni, Co)

Computational plasma: http://faculty.ucmerced.edu/vayyaswamy/research.html

–>plasmaFOAM, Ti=Tg+((m_i/3k_b)mu_i^2E^2), non-Maxwellian ion number density 10^19 #/m^3

–>sheath oscillation: in low pressure-stochastic heating (can’t apply LFA,local field approx), in high pressure-ohmic heating

Space charge limited emission: https://aip.scitation.org/doi/10.1063/1.5004654

–>in high pressure-Matt-Gurney, in low pressure-Child-Langmuir, further Schrödinger

–>Rougher surfaces have lower breakdown voltage

Social impact: https://www.linkedin.com/in/sung-jin-park-b2a5b510/

Plasma-surface interactions: https://www.researchgate.net/profile/Carles_Corbella

Hall thruster, BN self heating, catalyst with carbon nanotube: https://www.researchgate.net/profile/Carles_Corbella 

Tensile stress btw atoms, quantum dots with thermomechanical stress: https://scholar.google.com/citations?user=wSJ6cxcAAAAJ&hl=en

–>larger atoms are collected in one dot

10kW, IEDF affects selectivity: https://scholar.google.com/citations?user=cRanOQUAAAAJ&hl=en

–>by lowering Q-factor under mismatch, more lossy matching –>e energy increases, equilvalent circuit mdelling by M.Kushner

Plasma-based tuning, lower resonance freq–sheath diminishes  https://scholar.google.com/citations?user=Qjw1ACoAAAAJ&hl=en

–>negative permittivity (meta material) — more number of electrons, conductivity increases

–>DC abnormal glow: i increases, res freq decreases

–>applied freq<< plasma freq (sqrt (e^2 n_e / m Epsilon_0))

–>alpha discharge –> walls are protected by ion bombardment

Double negative meta material (Epsilon<0, Mu<0): https://scholar.google.com/citations?user=LknRjyEAAAAJ&hl=en

–>1 W, low pressure, dielectric resonator

RF manipulations: https://scholar.google.com/citations?user=PKxNAt0AAAAJ&hl=en

–>tuning number of electrons (n_e), Epsilon(V)=1-n_e/(w^2+v_m^2) where v_m^2=collision resonance freq which is a func of pressure

–>define ‘effective secondary emission coefficient’, i increases, cathode sheath diminishes for gamma mode of RF disch–>it is like DC with switching polarity (AC?)

–>P_noise / delta f = 4kT_e / (1+w^2/v_m^2) , power noise, in metal just  P_noise / delta f = 4kT_e but as noise reduces, conductivity decreases.

–>if purpose is to produce high number of electrons, HV, high pulsing rate –>low Te, high n_e

–>Add H2O vapor to reduce T_e

–>pd – 0.0001 Torr cm , field ionization, 20 ps ignition time (e time of flight) n_e – 10^10 cm^-3

CNT growth on substrates, energy storage applications, super capacitor: https://scholar.google.com/citations?user=N2yMgt8AAAAJ&hl=en https://engineering.ucsb.edu/~mjgordon/research/index.html

In-situ plasma catalysis: https://www.research.manchester.ac.uk/portal/en/researchers/chris-hardacre(c10c2a33-9679-4501-b20f-272a2460b25c)/publications.html

–>NOx with HC, CO2 selectivity increased with Al2O3+Pd

–>Temp in plasma 100 C (?)

–>plasma jet in DRIFT, plastic dome,

–>EXAFS data

–>SEI: 2.637 kJ/L

Carbon arc discharge: http://pdml.tamu.edu/

–>600 Torr, 2mm, e, He, C+, C*,C2…

–>55-60 A, low ablation-low deposit if anode diameter is decreased

–>T_e-1 eV

Laser produced plasma: http://www.inrs.ca/mohamed-chaker?f=publications

–>0.8 THz

–>VO2 for microsatellites

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, allowing the design of new catalysts. This will have huge implications for industries, such as the production of fertilizers.”

If you spend a little time with chemical reactions and bonds, you should notice that we’re just saying reactants turn into some products. The intermediate mechanism is tried to be explained by collision theory and density functional theory. There are many other interpretations in the literature, but there are millions of different possibilities for the reaction paths which are all simplified to understand the process. I wish I can comprehend more about quantum chemistry because after all, the microscopic behaviors are driving a reaction resulting in macroscopic properties. For now, simulations are valuable tool to observe the possible pathways and quantum computing is a promising approach for quantum chemistry.

World-first quantum computer simulation of chemical bonds using trapped ions

 

 

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, how many stars should be covered with spheres? 100, 1000, 100000000 ?! I don’t think the only possibility to use this idea is just for the stars lost in the horizon. The expelled radiation can give enough thrust to spacecrafts, only if that radiation is collected and transmitted to the busters. Agh! We’re so little for the universe!

An advanced civilization could resist the accelerating expansion of the universe

 

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 plasmas are free of sawtooth gyrations thanks to a mechanism that has long puzzled physicists.”

For the large scale fusion plasmas, it seems like a real challenge!

No more zigzags: Scientists uncover mechanism that stabilizes fusion plasmas

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 version:

Hard version:

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