Moreno

You started off talking about a 'plasma cushion', now you are talking about a cloud of electrons so which is it?

 

And while you are at it please address my queries about traffic dynamics.

 

For instance you now say that the machine will have to be confined to special road.

 

So how would I get home, or are you proposing laying this system everywhere, replacing all the existing roads?

 

If you do this how will pedestrians, ladies with prams, dogwalker, cyclists, horseriders etc get about?

 

How much will it cost?

 

Can you have more than one vehicle an the track at a time (you can't with maglev or any train for that matter)?

Plasma cushion wasn't my idea, I provided a link to it. Because the author didn't provide enough explanations,

I started to engage in phantasies on how it may work. For now I don't have a precise idea, just very broad idea.

I thought if you have negatively charged bottom of a car (it can be a charge permanently embedded in a dielectric,

and the Earth has negative potential too, then under certain conditions negative charge cloud placed between Earth

and bottom of a car may work as a cushion. Under condition these charge will not create a lightning and will not electrocute someone. No, I didn't mean a special roads have to be build. It suppose to work on any surface.

Ultrasonic levitation may be another interesting (and probably less dangerous idea). It may work not only as a mean of levitation,

but a method of propulsion as well. You may direct acoustic waves under different angles under the bottom of car and thus manipulate with way of direction.

 

It's not going to be that simple - ever tried landing a light aircraft in a serious crosswind?

Light aircraft has only one drive propeller. According to my knowledge there is no additional stabilization drives to the back of its body.

Also I meant levitating car, not a flying car. It suppose to levitate just 30-50 cm over the ground. Therefore there should be much less problems with wind turbulence.

And they never, ever think of how it's going to handle side winds.

Either charge cloud suppose to create some kind of traction between a car and road (something similar to quantum

locking). Or some additional small reaction drives have to be installed to correct the car right-left position.

Can a car have electron emitters under its bottom and levitate on that charge cloud?

Some futurologist predicts that a vehicles may be designed to levitate on a plasma cushion:

Maglev trains have been around for decades. Levitating cars won’t use anti-gravity in my lifetime, so magnetic levitation is the only non-hovercraft means obvious. They don’t actually need metal roads to fly over, although that is one mechanism. It is possible to contain a cushion of plasma and ride on that. OK, it is a bit hovercrafty, since it uses a magnetic skirt to keep the plasma in place, but at least it won’t need big fans and drafts. The same technique could work for a skateboard too.

 

https://timeguide.wordpress.com/2014/10/10/the-future-of-levitation/

Does anyone can imagine how exactly it will work?

 

1)

Yes this is true of monovalent metals.

 

The monovalent metals enjoy a single electron in the outer s orbital in the free atom.

Thus the orbital is half full.

 

When N such atoms combine to form a metallic solid these combine to form the conduction band each original s orbital contributes 2 spaces to the band.

So the band has "N spaces and N electrons.

 

So it too is half full.

 

The next (empty band) is formed from the empty outer p orbitals. This has a definitely higher energy than the s conduction band.

 

So there is a definite gap between the upper half full band and the next empty band.

 

2)

So why does the resulting monovalent metal sold conduct?

Well the conduction band is half full.

This is ideal to accept an electron moving in from somewhere else.

If fact the maximum number of moving electrons that can flow is N.

N are moving in and N are moving out of a given zone.

To achieve this you need N filled and N vacant spaces.

 

 

An insulator has full band and cannot accept further electrons.

 

It is possible to develop this simplified explanation to cover pretty well all cases and consider the roles played by the various gaps, overlaps and abutments between bands.

So, valence band in monovalent metals is completely empty and therefore it can't conduct even a single hole?

 

Holes are formed when an electron is promoted into a higher level band, leaving behind a hole.

 

The electrons we are discussing are already in the band.

 

So there are no holes.

So, in this case monovalent metals suppose to show 0 hole conductivity and their Hall coefficient should be extremely

negative. But Hall coefficient of copper, for example is just (-0.5) in comparison to that of Bismuth (+5000).

Is there some examples of metals or metal alloys in which there is plenty of free electrons and holes, but they never recombine each other?

^ Does it mean free electrons and holes never recombine in monovalent metals? Under which conditions recombination can happen?

Some sources claim there is a substantial band gap between valence and conduction bands in monovalent metals. It might be associated with half-filled zone. Is it true or not? If it's true then why they are still metals and not a semiconductors?

Fig.2.2.10 Possible energy band diagrams containing one filled or partially filled band and one empty or partially empty band. Shown are a) a half filled band, b) two overlapping bands, c) an almost full band separated by a small bandgap from an almost empty band and d) a full band separated by a large bandgap from an empty band.

https://ecee.colorado.edu/~bart/book/eband3.htm

http://www.schoolphysics.co.uk/age16-19/Electronics/Semiconductors/text/Semiconductors_/index.html

In the monovalent metals the electronic band structure is strongly affected by the size of the band gap E _s-E _p at the Brillouin zone faces, a large gap implying a large distortion of the Fermi surface. Here E _s and E _p are the energies of the purely s-like and p-like states on the zone faces.

 

http://whitenoise.kinja.com/graphene-miracle-material-1575961841

 

Ingesting electrons (and holes) occurs with all foods, doesn’t it? Think about salt.

 

Supplementing the diet with medicinal charcoal should provide some graphene,

since the char is essentially like "inertinite" macerals, and thus contains graphene.

 

 

 

 

Fig. 7. Structure of biochar with different functional groups present on its surface

(Adapted and redrawn from Brennan et al., 2001; Lehmann and Joseph, 2009).

 

~

Recently scientists discovered by means of practical experiments (something that was predicted for a while ago) that

graphene may not be feed by electrons and holes for a months and still feel quite vigorously. And you care about

some salts... Well, I will take it to attention.

http://pubs.acs.org/doi/abs/10.1021/acssuschemeng.5b00771

 

Complicated stuff that doesn't matter much unless you're using it for something specific.. Unless I'm wrong. In which case someone will correct me.

So, this property shows up in quantum dots only, not in intrinsic graphene?

I wish to know what will happen if we will ingest the same amount electrons and holes in graphene?

Someone said me that electrons and holes in graphene are separated spatially.

What does it exactly mean?

The thing is with a flywheel, that the energy density isn't critical for all applications. So you don't always have to be using such high speeds, or expensive materials.

I don't think that flywheels will ever be suitable for road vehicles, because of the forces involved if you change direction.

What if you use two flywheels which rotate in opposite directions on car?

The problem with flywheel, however, it that if it's made of non magnetic material (similar to a diamond fiber) I wonder how they are going to use magnetic bearing with that.

Hmmm. I haven't done any flywheel calculations in a long time. Flywheels don't actually store energy by stretching bonds; the bond-stretching is a by-product of the stress created by the rotational motion. The first order storage is purely kinetic. But the bond strength would of course be one of the limiting factors.

 

I'm hitting the sack for the night - catch you again later. Maybe before I sleep I'll put in a pre-order for my very own De Beers flywheel.

Honestly, I have no trustworthy calculations for flywheels made of "supermaterials". For example, this one article mentions 1100 Wh/kg for a hypothetical carbon nanotube flywheel.

http://www.nanowerk.com/spotlight/spotid=22055.php

Yes, I meant that in both flywheels and capacitors atomic bond strength is a limiting factor. In capacitor you may play with some quantum effects furthermore, I assume. What do you mean under "bond stretching"?

Well, fuel cells still use fuel; it's not an all-electric technology that could use electricity sourced by nuclear power.

 

Can you recharge a fuel cell? By that I mean by inputting electrical power, as opposed to adding fresh fuel. If so, how fast is that process?

Aluminum is produced with help of electrolysis from aluminum oxides. You can use cheap electricity from remote sources, or electricity from nuclear or hydroelectric plants produced at night. This is how most of Aluminum is produced presently.

You can just fill a fuel cell with Aluminum powder or wire at the fueling station. It will take couple of minutes.

I think we've talked in another thread about capacitors vs. chemical energy storage. Humans have accomplished too many amazing things for me to say "never" very easily, but pure electric energy storage has a tough challenge to compete with chemical storage. I believe the point I made in the other forum was that the former stores energy via fields without breaking / forming chemical bonds, whereas the latter does have access to the full energy of those bonds. Like I said, I won't say never, but I have severe doubts.

 

It's predicted that a flywheel made of diamond wire would have 15 MJ/Kg energy density. Similar or even higher estimates are made for carbon nanotube wire, boron fiber or nitrogen fiber. Compare it to 3.5 MJ/kg for a hypothetical, yet to be created Li-air rechargeable battery, which suppose to have the largest energy density of all batteries.

I have suspicion that both flywheels and capacitors belong to a similar class of an energy storage devices which store their energy in atomic bonds deformations. Therefore it may give a clue about capacitors future limits.

I've never been very enthusiastic about electric vehicles. It's cool technology, and I was loosely connected with a couple of EV programs while I worked at UT Austin. But I've always felt that the battery technology available was limiting.

Fortunately, electrically rechargeable batteries is not the only technology which could make EVs to dominate. I even wouldn't expect it will be the batteries. With their dirty chemical reactions they don't look like a futuristic energy storage.

I propose you to regard supercapacitors, metal-air fuel cells and long-distance wireless energy transfer.

Also, EVs is not the only type of a vehicle worth of the inventive efforts. In this century hybrid vehicles may become dominant. If plug-in hybrid will allow to save 80-90% of organic fuel annually, we may say that problem of EV is almost solved and celebrate.

I'm an electrical engineer by training, but I don't claim familiarity with battery chemistries. I do have a good understanding of EM field theory and so forth, though. Within EE I'd say my specialties are digital electronics / computer architecture and also electromechanical energy conversion.

 

What's yours?

My undergraduate training and the largest part of my career relate to the digital electronics area. My PhD research and the smaller part of my career relate to the electromechanical conversion area.

I'm too modest to claim an expertise at something. I'm an amateur inventor and my interests presently are at the fields of energy storage and conversion devices.

Well, they mentioned that they can be charged much faster than Li-ion batteries. It's hard to see why power would go faster one way but slower the other way. I'm definitely not an expert, though.

What is a field of your expertise?

Maybe pressurize it in a container rated for pressure. (Or just put it in and let it pressurize itself). Not sure though.

At the moment I'm a theoretician.

Solid state electrolites (such as ion-conducting glasses) are nothing new. The problem is that conductivity of solid electrolytes (and especially that of glasses) is much lower than conductivity of liquid electrolytes. This is very difficult to change because it is based on physic's laws.

Li-ion batteries commonly use organic electrolytes. They may not be too cheap and are flammable, but at least they offer acceptable power densities (which are still not too exceptional). With glass electrolytes power may fell below acceptable level. The article doesn't mention this problem. I don't think its likely energy density will grow a few times with glass electrolyte. Why exactly?

Do they expect that glass electrolyte will take much smaller amount of space than a liquid one? If yes, why?

Some expressions from the article are difficult to comprehend of believe in them instantly. For example:

glass battery charges in “minutes rather than hours.” This, she says, is because the lithium- or sodium-doped glass endows the battery with a far greater capacity to store energy in the electric field. So, the battery can, in this sense, behave a little more like a lightning-fast supercapacitor. (In technical terms, the battery’s glass electrolyte endows it with a higher so-called dielectric constant than the volatile organic liquid electrolyte in a lithium-ion battery.)

 

Batteries and capacitors store energy in different ways. What is good for a one is hardly good for another. High dielectric constant can be barely useful for a battery or a supercapacitor. Only for a dielectric capacitor.

Insects practiced flight mode at least 300 mln. years ago, and therefore we know that relatively safe flight of a living being is a reality.

The problem is to suite it to modern civilization.

Which stimulants in difference from caffeine develop almost no tolerance and cause no problems with heart? They suppose to be available over the counter. I agree to regard some "overdose" substances under condition they cause no harm to health and only produce a strong stimulant effect.

Experimental results for methane adsorption on two high-surface area carbons (TE7-20 and AX-21) and one metal-organic framework (MIL-101(Cr)) are presented, with isotherms obtained at temperatures ranging from 250 to 350 K and at pressures up to 15 MPa. The isotherms were analysed to determine if these materials could be viable alternatives for on-board solid-state storage of methane. The results show a very high adsorbate density in the pores of all materials, which for some can even exceed liquid methane density.

http://opus.bath.ac.uk/43715/

These claims sound a bit unbelievable. Energy density of liquid methane comprises 2/3 from energy density of gasoline and if some materials allow the same or even higher density for adsorbed methane, why there is still no global efforts to replace all the gasoline and diesel with methane?

This one article mentions 500 v/v methane uptake at 400 bars, compared to 600 v/v of liquid methane.

http://onlinelibrary.wiley.com/doi/10.1002/ente.201600172/abstract

Sorry, maybe it is better if I refrain for commenting it further. I can easily be wrong as so many times before. (I was thinking on some folk tales, myths and legends spoken in Slavic culture where revenge is a common motivator,

Very interesting... Which exactly legends?