harlock

44 minutes ago, swansont said:

In what situations?

Where there is no space to land while a 'balloon' can be on top tied to the ground with a rope

1 hour ago, exchemist said:

Doubtful as a hoist, since the volume required to lift any significant weight is so large. 

Air weighs ~ 1.225 kg/m3 while h2 ~ 0.09 kg/m3, so 1 m3 H2 
gives an upward thrust of approximately 1.225-0.09(~1 with 2 bar H2) kg/m3 without considering the

On 10/1/2020 at 10:05 AM, Mnemonic said:

According to the bible Jesus Christ was a supernatural character who could walk on water, occasionally talked to Satan, and could turn water into wine, amongst many other marvels.

Can you be a scientist and still believe in this stuff? As far as I am concerned, you should not be called a scientist or be allowed anywhere near any scientific endeavour if you believe in fictitious myths.

Am I being too aggressive in my attitude? Probably, however science and the scientific approach to research application is a serious technical field that should not be sullied by ridiculous fairy tales.

 

>Please move to the Religion section..

Here the logic is this: I do 'impossible' things to make people believe that I come from God. It was really important because Jesus brings eternal life, that is, forgiveness from original sin. Jesus time is the last about Daniel 70 weeks to be forgiven from original sin. It's an incredible importance. I think it's logic. It's not a scientific question.  

For example an airship-hoist can be more useful than a helicopter. 

it's a kind of balloon in the drawing.

What do you think about a useful h2-aircraft in the future?

20 hours ago, Sensei said:

No. Not exactly.

Organisms that use photosynthesis to create food absorb photons in certain visible ranges and use them to break down CO₂ and H₂O molecules to produce the compounds they require.

https://en.wikipedia.org/wiki/Autotroph

Typically, energy flows from the source, which has a higher temperature, to the body, which has a lower temperature.

The human body temperature is about 36.6 C, and the ambient temperature is typically lower, so we warm the environment.

Green parts of the plants, which are designed to absorption of the photons (not green one range!), are absorbing photons, so they are not absorbed by something else.

The absorbed photons (by whatever) are re-emitted at lower frequencies, such as infrared, and absorbed by something else, and the energy is retained on Earth.

White rock reflects photons of visible light, while black rock absorbs photons of visible light.

Some of them are re-emitted into space. In this way, the Earth can be seen in the range of infrared and other photons.

Animals live on sun's energy through plant photosynthesis, all the energy they consume comes from solar energy.

It means that all the solar energy that the animals(decomposers... also) used goes back to the environment (as you also say).

The only 'solar fuel' of the plants that remains is trunk and branches, which store solar energy for millennia(removing it from the

environment). So the difference in the amount of trees between centuries ago and today is that there is less solar energy

in trunks and branches of trees. MAYBE the cycle of glaciations depends on it because there was an alternation between

glaciers and forests... I say MAYBE because it's only an idea for now...

Therefore neglecting this aspect is serious in the fight against global warming because we could grow more tree crops,

recover agricultural residues for steam engines..., raise livestock in symbiosis with forests (goats. They feed on leaves

and have the best milk), use palm oil as fuel ..., etc...

-the heat of wood burning in a fireplace comes from the sun

 because of Lavoisier quote('nothing is created and nothing is destroyed but everything is transformed')...  

The heat of the burning wood comes from solar energy.

So trees store solar energy by removing it from environment. 

The absence of trees causes a greater dispersion of solar energy

in the environment causing an increase in temperature(Global Warming regardless of CO2). 

All the wood mass we see is related to the solar energy stored by the

trees for many years. 

(I haven't considered the fruits of the trees etc, which in a year decompose and release solar energy and

CO2 again)

About it

1-Can there be a relationship between glaciations-forest decrease and forest increase-ice retreat(Glaciations cycles. Regardless of CO2)?

2-How much does it affect global warming? 

On 4/11/2022 at 9:16 PM, sethoflagos said:

In principle, it should be possible to incorporate a micro Combined Cycle Gas Turbine power plant into the design of a large tractor unit. Modern designs of CCGT are routinely specified at >50% thermal efficiency, so it should represent a major advance on your historic baseline.

Putting solid fuel through a GT is a bit problematic so you'd likely be looking at some version of liquid biofuel (biodiesel, ethanol etc) for base fuel as a practical proposition. 

Following combustion in the GT, the exhaust gas would pass to a HRSG (Heat Recovery Steam Generator) raising superheated mains steam to feed a condensing steam turbine, with condensate recovered from (perhaps) overhead air cooled condensers for return to the steam drum. The water circuit would therefore be closed cycle.

The split of power output between the cycles would be of order 2:1 (GT:ST) so I guess it wouldn't quite be pure steam punkery. 

Surely pellet(solid fuel) from agricultural residues would replace a liquid carburant(diesel especially...) where it'd be possible to use it(in agricultural machines for example). 

Please note

I read that one hectare of sugar cane produces 10 tonnes of dry bagasse and 10 of dry leaves left in the field(They aren't used to obtain sugar). 

It's an incredible resource to have solid fuels...  It's energetically equivalent to around 8E3 litres of diesel without considering efficiency etc... 

6 hours ago, exchemist said:

In short, run a generator and store the energy electrically in a battery. 

Surely it's a good option.

3 hours ago, exchemist said:

When you add in the exhaust control measures needed to prevent pollution from straw burning, not to mention the inconvenience of needing to store five times the volume of fuel, and the need for getting rid of considerable amounts of solid ash at intervals, it becomes fairly plain why this idea is not going to fly.

It isn't a problem for agricultural vehicles... However solid ash represents only 3% as regards the combustion of wheat straw. Also corn stove pellets are  interesting(especially in the U.S.). Infact corn stover left in the field after grain harvest represents an estimated yield of 8-10 tonnes of dry matter per hectare! In addition it seems to have a solid ash content about 5%. It doesn't seem a high value.  

2 hours ago, exchemist said:

The big snag, it seems to me, about an EC engine burning biomass for transport, is that the combustion can't be turned on and off in accordance with the variations of power demand. So you will intrinsically waste a huge amount of energy by keeping the heat source burning all the time, even though you only use the full heat output sporadically. 

I think some energy needs to be stored first of all. Energy can be stored by melting some salt...or by storing water under pressure in an insulated tank... For example I know that NaCl heat of fusion value is around 30 kj/mol ( 300 kwh/m3! ) so 1 m3 of NaCl can store 300 kwh of thermal energy. But it's a high fusion temp for straw combustion...  

I read that the most (however I'm not sure) efficient steam coal-fired train was 27% efficient in the past century 🙂

link: steam train thermal efficiency. (browse pages up to the Third Generation Steam(TGS)). 

So...I wonder if it's possible today to build biomass-fueled steam engines for bulky vehicles(agricultural etc...).

Energy content of 1 liter of diesel is equivalent to 2.5 kg of wheat straw pellet(An example). 

BUT 1 liter of diesel costs around 1.5 u.s. dollars while 2.5 kg of wheat straw pellet is around 0.25 u.s. dollars. 

Problems can be: 

1-wheat straw availability   2-power  3-volume

I'll try to give some answers to these three questions

1-Wheat straw yield is about 3-6 tonnes per hectare. It's energetically equivalent to more than 1 tonne of diesel...

Is there availability for agricultural vehicles and (maybe) trucks in general? We'he to consider efficiency also... 

2-Vapour pressure can produce a great power. We know that Force=Pressure*Surface so if vapour pressure is 100 bar(In the water state diagram T is around 300°C) and surface is only 1 cmq we have F= 100 * (1e5 Pa) * (1e-4 mq) = 1e3 Newton! It's the force applied to low-middle power cars... I think it's no comments... What about efficiency? It would've to be around 27%... Comments? 

3-Wheat straw pellet density is about 0.5 kg/dm3. So 5 'liters'(2.5 kg /(0.5 kg/dm3) ) of wheat straw pellet is energetically equivalent to 1 liter of diesel(So five to one about volume energy comparison). Would it be ok for bulky vehicles? 

In this istance dq >= e(electron charge) !...

Is there an error in the calculation 
of the energy stored in the capacitors?

The fact is that the charge doesn't tend to zero but to the electron charge...

We need calculus to manipolate its properties and experience to be able

to make a good job obviously!

Another question about sodium is:

-Can it power a submarine?... It seems it breathes underwater like a fish...

I don't understand why God justice had to modify his judgement in Heaven. 

So, is new heaven referring to new planets?

Example: a new Mars with delicious fruit and very good animals 

Obvious question: scientifically speaking, can a new Mars give us a great natural life?

It's incredible what's happening in Italy!!

The previous government stopped immigration. A political rebellion created a new  government(two monthes before covid-19 beginning) and reopened immigration. But now they stopped immigration because of covid-19!!  (It seems a real miracle!!!)

Is God against muslim immigration in Europe?

Is God against Bergoglio(the Pope) who prayed for immigration?

There is no animal serum against hiv even if bovines(for example)

produce Hiv antibodies...

On 11/12/2019 at 7:11 AM, jim bell said:

Sodium can also be prepared by electrolying a molten salt, sodium chloride might do, although this would involve very high temperatures to melt the salt.

 

Probably it's possible to use wind energy to heat(using Faucault currents, so inconstant wind power isn't a problem) the salt. The very good news is that this molten salt has a great heat of fusion(around 250-300 kwh/m3) value so it can work even if wind is not constant.

Fe --> more than 500 kwh/m3 (Tfus. 1538°C)

Si --> more than 1e3 kwh/m3 (Tfus. 1414°C)

NaCl --> more than 250 kwh/m3(Tfus. 801°C)

Do you think it's possible to store a large quantity of (renewable)energy when a matter changes from a solid to a liquid?…

21 minutes ago, Endy0816 said:

In many cases there would be increased cost or other issues with alternatives. They may not be as durable, require more volume to ship or increase the product weight.

There some alternatives that might work. Leaves, Kelp Alginate. Mainly going to depend on what is locally available or possible to ship far enough.

Howere if plastic products are banned, their alternatives'd fill the market.  

No project about it.

I'm suggesting it to everybody because humans probably need it to save Earth planet from pollution.

My idea is to use renewable energy to melt NaCl in order to store it. Then humans can use molten Sodium Chloride to have constant electrical energy from changeable renewable energy...

p.s.

Wind, Sea and hydro energy are largely availabe on the Earth and can directly be converted into thermal energy by Foucault currents without using electrical resistances...: I think it's the key to have cheap renewable energy. if it's cheap, it grows and replaces pollutant energy sources. 

The required thermal energy needed to liquefy 1 m3 of NaCl is about 300 kwh(at least), infact its heat of fusion value is about 30 kj/mol ---> 300 kwh/m3, consequently 1 m3 of molten NaCl stores about 300 kwh of thermal energy at the same temperature(about 800°C)..before becoming solid again. The working Temp is around 800°C(T.fus of NaCl), so thermal to electric energy conversion is  potentially efficient.

Take a look at a RAD(Rapid Application Devolopment) programming language. An example is Lazarus/Delphi.

It's good for personal use...