LAB COFFEE TIME AND SWOP-SHOP

What kind of scale that should reach now ?

Microwave sintering?

But, does it produce SAVs?

Quote from Alan Smith

Just giving this a clean and a few tweaks - nice Nikon Epiphot metallurgy scope from a University lab.

Good for you! How did you get this? Did they sell it to you at a discount? Did they throw it out, and you retrieved it from the trash? Break and entry?

Quote from JedRothwell

Break and entry?

He went in through the skylight on a rope, utterly balletic in his avoiding laser trip wires and roaming security guards.

This video is from a tinkerer channel I follow for some years now, and this one features a very robust and surprisingly powerful design and build of Tesla Turbines that I think is very good to be aware of for our shared interest in heat to energy transformations systems. The good news is that one can buy one of these and are customizable.

Quote from Curbina

this one features a very robust and surprisingly powerful design and build of Tesla Turbines

Thanks Curbina - it is an interesting video.

I've been seeing builds and strip-downs of Tesla turbines for decades - with variable results.

As the design relies on viscous drag (together with the Coriolis force), it does tend to work well on a small scale. And, as shown, a bunch of thin flexible discs is easier to build (and balance) than a typical bladed impulse or reaction turbine.

The main problems I've seen on older builds - used with steam - have been related to creep and distortion of the discs. It is possible that these could be overcome with the right materials - but having to resort to exotic (and costly) creep-resistant metals loses the advantage of cheapness. Note that on this video they were driving the turbine with compressed air - which does get around some of the problems encountered with steam - but requires someone to run an engine (or an electric motor) to power a compressor. So, historically, as the prime mover of a heat engine, the Tesla turbine hasn't been proven to have any real advantages.

But maybe it just hasn't found its proper niche yet.

Quote from Frogfall

Thanks Curbina - it is an interesting video.

I've been seeing builds and strip-downs of Tesla turbines for decades - with variable results.

As the design relies on viscous drag (together with the Coriolis force), it does tend to work well on a small scale. And, as shown, a bunch of thin flexible discs is easier to build (and balance) than a typical bladed impulse or reaction turbine.

The main problems I've seen on older builds - used with steam - have been related to creep and distortion of the discs. It is possible that these could be overcome with the right materials - but having to resort to exotic (and costly) creep-resistant metals loses the advantage of cheapness. Note that on this video they were driving the turbine with compressed air - which does get around some of the problems encountered with steam - but requires someone to run an engine (or an electric motor) to power a compressor. So, historically, as the prime mover of a heat engine, the Tesla turbine hasn't been proven to have any real advantages.

But maybe it just hasn't found its proper niche yet.

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I think I am quite well aware of what is widely said about Tesla Turbines, yet they are of interest for me because they can help get better efficiency in the kind of waste to energy system I am focused. The ones shown by this maker are surprisingly efficient for the material

of the elements (thin aluminium sheet), and they work fine with steam, there are several videos in the channel linked in the video I posted.

Quote from Curbina

I think I am quite well aware of what is widely said about Tesla Turbines, yet they are of interest for me because they can help get better efficiency in the kind of waste to energy system I am focused. The ones shown by this maker are surprisingly efficient for the material

of the elements (thin aluminium sheet), and they work fine with steam, there are several videos in the channel linked in the video I posted.

The turbines I was talking about were used as HP stages on Rankine Reheat Cycle plants - so the superheated steam regime was quite arduous. I've also seen them proposed for Rankine Topping Cycles, with even more agressive fluids. In both situations you can sometimes struggle to get a sensible life out of any type of turbine technology.

As I've said about Stirling Engines, the Tesla Turbine seems to have suffered from being proposed for use in situations where it was doomed to failure - as if it was some kind of magic technology that could overcome known problems. Conventional turbines work well, having have had many years of development, and so present few surprises. Even the erosion problems with Wet Cycle turbines, as used on nuclear plants, have been largely ameliorated.

But maybe you will find that application niche.

Quote from Alan Smith

Just upgraded my scope in anticipation of testing the Egely device. My current Rigol 1052 is limited to 50MHz - this one can handle 150 (they claim). I would like better, but the budget isn't infinite.

https://www.ebay.co.uk/itm/385077468967

So how well has this instrument worked out for testing Egely Devices, Alan?

Quote from Alan Smith

Just bought a couple of these

I've got a bunch of these things.

They only operate in PWM or pulse modes (no sine or sawtooth), but (like your's Alan) are fully controllable up to 150kHz.

These have the advantage of containing their own mosfet, which can switch up to 30V and 8A. (They are usually sold as motor controllers.)

The signal from them is nice and sharp. If/when I need to switch more power they could easily drive an external device.

Before this great and interesting time and to remain a little bit still sticked on the current ground, does anyone know a way to obtain around twenty grams of pure lithium without being defrauded by a Chinese website, or European , or an US one ?

The truth life of experimenter in fact, need help to be able to believe a day in a world as Jed described

Quote from JedRothwell

People have expressed concerns that cold fusion might clobber the economy if it lowers the cost of energy dramatically over a short time. I have been thinking about that. No doubt it will clobber the energy industry itself, including oil companies, electric power companies, wind turbine manufacturers and so on. But will it harm other industries? Will it harm the economy as a whole?

To address this, I looked for an energy intensive industry. One that has experienced dramatic cost reductions in the past. Air transportation is a good candidate. Two aspects of it stand out:

1. For domestic flights within the U.S., energy costs 20 to 30% of airfare. That is a larger energy cost than most goods and services.
2. Since 1950, airfare costs have fallen 85% in inflation adjusted dollars.

Here are some graphs of these trends.



https://www.slideserve.com/kat…werpoint-ppt-presentation p. 36



https://www.iata.org/en/iata-r…raffic-growth---monterey/ p. 22

The axes labels in the second graph are confusing. I think the blue line is the cost per ton-kilometer the airlines pay, and the red line is what they charge passengers.

(Note that passenger traffic is measured in ton-kilometers, estimated at roughly 0.1 ton per passenger, including baggage. In the U.S. this is generally measured in passenger miles.)

As I said, costs and fares declined 85%, an average of 1.2% per year. Most of the declines occurred soon after two dramatic changes: the introduction of jet aircraft in 1960, and deregulation in 1980. The wide-bodied Boeing 747 that carries 490 passengers was introduced in 1969, but it did not have such an immediate effect as the Boeing 707. The largest sustained cost reduction occurred from 1960 to 1972: 60% over 12 years, or 5% per year. We can expect that cold fusion will produce a similar decline in costs. I expect it will be less abrupt: ~30% over 20 years; ~1.5% per year.

The effect will begin immediately after it becomes generally known that cold fusion will replace oil, even though it will take decades to develop cold fusion aerospace engines. It will begin immediately because the announcement of cold fusion will lower the cost of oil. The oil companies will rush to sell their reserves while the oil still has value. They will stop drilling and making new oil tankers and pipelines, reducing their expenses. In other words, they will hold a 20-year-long bankruptcy sale. Oil will be cheaper, but it will never compete with cold fusion. Cold fusion fuel costs nothing. Oil will always cost something, because you have to extract it, ship it, refine it, and distribute it from gas stations.

When cold fusion aerospace engines are introduced, the cost of using them per passenger mile will be far cheaper than kerosene jet engines, because the fuel costs nothing. Even after introduction, the cost will continue to decline. Because equipment manufacturing and maintenance will be cheaper. I base this on predictions for upcoming battery powered electric aircraft engines. They are expected to cost less per kilowatt of capacity, and less to maintain, because they are simpler and cleaner. This is also the case with electric vehicles (EV) compared to gasoline automobiles. This continued decline will happen gradually over decades after the introduction of cold fusion engines.

After cold fusion technology matures and takes over all energy markets, oil will still be needed for chemical feedstock for plastics and other products. However, this demand will be met with synthetic hydrocarbons made with cold fusion. It will be synthesized on site at factories that make plastics, using local sources of water (hydrogen) and carbon (such as wood, coal or garbage). That will be cheaper, easier and safer than drilling and shipping oil.

The 60% rapid fall in airfare in the 1960s was more than offset by the increase in passenger traffic. With cold fusion, airlines and other energy intensive industries will save a lot of money, and with competition they will charge customers less. As long as there is a growing demand for their products, this will not reduce their profits. To be sure, there is a limit to demand for air travel. We would not all want to take a trip by airplane every week.

With cold fusion we will make our own energy instead of paying the oil companies and electric power companies. Some people fear this will bring much of commerce to a halt. It is true we will make our own energy, but we will not make our own airplanes, or fly our own airplanes. We will not make our own automobiles, hot tubs, or any other goods or services that consume a lot of energy. Airfare may fall by ~30% with cold fusion, but it will not fall to zero.

The energy industry is one of the largest in the world, similar to agriculture, weapons production, and war. “In 2021, the U.S. spent $1.3 trillion on energy, or 5.7% of Gross Domestic Product (GDP). On a per capita basis, annual energy costs were $3,967 per person.” (https://css.umich.edu/publicat…s-energy-system-factsheet) Per capita costs include children. A family of 4 will save $16,000 a year. That does not mean the family gets $16,000 directly. This includes money spent by corporations to make products the family buys, and the family's share of energy used by the government, the military and others. Still, the family would save a lot by not buying gasoline, and as the cost of food and manufactured goods falls. The family will spend this money on something other than energy. A better apartment, or college education without student debt. The money will not disappear. It will not be wire transferred to Alpha Centauri.

Military expenditures are $2.2 trillion per year worldwide. (https://www.sipri.org/media/pr…-european-spending-surges) If war were to cease, and spending on weapons reduced to zero, we would not worry about the effect on the economy. We would not fret that this might reduce overall economic activity and leave many people without jobs.

It is difficult to find estimates of worldwide energy costs, but they are approximately $6 or $7 trillion per year. “More than US$6,000 bn -- 10% of the world Gross Domestic Product (GDP) -- is spent each year in the world for energy purposes. This places energy second to health care expenditures in many countries; and in some cases first.” (https://www.enerdata.net/publi…-energy-expenditures.html) Oil is the largest portion, at ~$4 trillion. It will decline rapidly in the next 20 years as EVs replace gasoline vehicles.

There is no reason to fear the gradual decline of the energy industry, as long as it does not happen overnight. It will take 10 or 20 years after the introduction of cold fusion. Machinery cannot be replaced any faster than this. Worldwide GDP is estimated between $86 and $97 trillion. The gradual loss of $7 trillion would make little difference. Other industries will be enhanced by cold fusion, and they will grow more than $7 trillion.

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