Sewing?

A lot of confusion here between charcoal and coal, which us understandable with their English etymology.

What you asked about is charcoal which is not at all the same as the combustible mineral called coal. Though coal does have a "charred coal" pure carbon corollary, confusingly known as coke

Charcoal is what is used for filtration and absorption, and is simply pure carbon produced by pyrolysis of (usually) woody material in the absence of oxygen. When this is done, all of the non carbonaceous volatile compounds are driven off, leaving pure charcoal.

If the pyrolysis is done completely, then the parent wood has no bearing on the properties of the charcoal, because all of its other components have been removed.

I have cooked quite a bit of charcoal from woods of all types for use in forging and metal casting. And regardless of the starting wood, the end product is the same. Indeed the only difference is the yield, which is simply because of conservation of mass - starting with denser hardwoods allows packing more material into the same space within the retort when compared to a light softwood.

Once cooked, it's all the same.

They do, and it is only just becoming understood. Nitrogen fixing bacteria live inside the plant on and in nodes on the roots, where they exchange nutrients for sugars.

There are also free living nitrogen fixing bacteria that associate with plants within the biofilm they secrete to coat their roots. Plants will also secrete other compounds to recruit bacteria and fungi partners who specialize in extracting certain nutrients the plant is deficient in.

But this process occurs on the surfaces, the tips, and intracellularly within the roots, as well as within special chambers within the roots that host symbiotic fungi.

Each plant species has preferences for the bacteria and fungi it associates with. But they definitely live within the plant, in ways we are just learning.

This does not sound hypothetical to me. There's several ways you can die doing this:

If this tube is iron and was sealed airtight, the rust that has occurred inside will consume the oxygen within. People have died entering pontoons, tanks, pipes etc for this reason.

If there's decaying material oxygen can be reduced in a similar way, and hydrogen sulfide can also be present, which can incapacitate you even if there's enough oxygen.

It might be okay, it might not. Mostly low oxygen conditions won't give you a warning, you will just pass out.

You should stay out of it. If you can't resist, then rent a gas sniffer to check O2, CO2 and hydrogen sulfide levels.

Reduced shank drill bit is what you want. Mcmaster Carr has them and everything else.

You can also chuck it backwards in a drill it does fit, and then spin it and grind the shank down, if you're careful to keep true it will work ok- a poor man's lathe.

Winter wheat does - it's in the name. It requires a certain amount of cold temperature exposure as a seedling (fall planted and overwinters) to vernalize or else it won't enter reproductive life stages, and remains a grass with no seeds.

Wouldn' friction with outer layers be a factor here?

Yes batteries can do this for a DC system like in your car. But that is mainly a voltage regulation function.

Power quality correction is a consideration in large industrial AC power networks. It helps with the problems that arise from running large amounts of electric motors where the power factor gets out of balance between inductive and reactive currents.

Since electricity essentially sees the coils within a motor as an inductor, it affects multi-phase power in a way that's detrimental to its ability to transfer power

So capacitor Bank systems are designed to correct the issue so that the overall AC power quality isn't effected for downstream users.

Others covered chemical vs field storage, but there's also differences in practical useage. Capacitors work better for shorter term, rapid cycles, and large fast energy discharges. They can also correct power quality in a way batteries can't.

Batteries work better for long term storage, shallower discharge, and sustained energy conversion over a long time.

This is the answer. Something is loose, OP needs to find that and tighten or secure

I mean the real reason it didn't pan out was the same group physchology behind all fads - were fidget spinners fun to play with? Sure, but nowhere near enough to justify 40 billion of them being made in 18 months. And the manufacturers who hopped on last didn't do real great I'm thinking.

The meat was all right, and there's a limited market for feathers and leather. If you can find it, and if you can find a butcher who will process them.

But it was, and is, a tiny market. Americans were in no way ready to drop beef for emu. It's hard to market lamb and goat, let alone ostrich.

The ostrich/emu and alpaca fads are very similar because neither is really about harvesting anything but instead about breeding to satisfy growing demand. Which makes it a bubble, a fad, a craze, like Dutch Tulip Mania hundreds of years ago.

Most of the people raising them never wanted to kill them, they were hobby farmers and these were their cute pets. But they thought they could make big bucks setting everyone else up to grow cute pets too.

And that inherently has an end to its profitability.

They were a fad for small farms for a while in the 90s. Everyone was going to get rich selling ostrich meat, it was healthier than beef yada yada. Fertilized eggs were selling for ridiculous prices.

And now? Nothing.

The fad has moved on to alpacas now. Everyone is going to get rich selling that alpaca wool.

There is no one model. And in many aquifers no one much knows where or how water moves. So long as it's there to be tapped it's ignored.

The aquifers that are better modeled are the ones that have problems affecting the people using them. Regionally here that's the Odessa - overtapped for irrigation. Several underlying the Hanford site - contaminated with radioactive and chemical waste threatening a city's wells. And in the 1000 springs aquifer in Idaho - where aquaculture, agriculture and river flow needs for salmon collide.

There is a pretty good idea of where a liter of water dumped onto the ground is going to go, how long it's going to take to get there in those places.

But each one has entirely unique hydrology and geology. Their models don't interchange.

Yes, there are upper limits, and things get difficult as you approach them. There are "softer" limits imposed by infrastructure capacities, "firmer" limits imposed by seaworthiness considerations, and finally hard limits due to material properties and the forces involved.

Others have covered infrastructure limits, so I'll begin with seaworthiness. Bigger ships are more fuel efficient due to the square cube law, and industry has pursued that advantage by increasing size dramatically. But bigger ships require more steerage way, and are less controllable at low speeds. They also need more power to overcome wind and current. They are hard to control in tight harbors and locations without sea room.

The final limit is materials. Humans approached the upper limits of wood ship size, and the biggest wood ships had considerable hull volume devoted to reinforcing frames, stringers, laterals etc. All necessary to deal with the unequal forces imposed on a ship's hull. Not only by wind and waves, propulsion, but by the inequal buoyancy inherent in making something pointy that will go through the water efficiently. There is less buoyancy at the thin ends than amidships, and over time and constant movement that causes wood (and metal) ships to "hogback", where the bow and sterm droop and the middle rises.

We never solved the issue with wood construction, we simply found stronger materials. First iron, then steel, and now higher strength steels.

But the bigger the ship, the bigger the forces, while the tensile strength of steel remains about the same. To prevent buckling under dynamic loads, more and more payload consuming reinforcement has to be added inside the hull, until like their wood forebears, it becomes impractical.

At that point, maybe we'll find a new material again, and start over with a brand new limit.

There's a lot to consider here. What's the body of water, a lake or a pipette? Is there a temperature difference?

Convection, capillary forces, diffusion, surface tension, vapor pressure, temperature and purity will all affect this.

They haven't followed their own advice very well, because they still seem to be colliding and near missing ships pretty regularly.

Just had two in San Diego bay a short time ago.

I agree the watchstanding needs an overhaul or at least get it back to it was in eras our ships didn't burn down pierside or collide with freighters regularly.

The answer is going to depend tremendously on the fuel used, the conditions of burn, and any stack scrubbing or recapture equipment present.

Internal combustion engines have a starting advantage in that they tend to burn "cleaner" fuels - especially in the past. But external combustion systems have the advantage of larger plants and (generally) more space and attention to efficiency and emissions.

Looking at coal alone, there's a lot of variation among coal fields, as well as categorical differences between soft brown coal and anthracite.

But in any case, a cleaner starting fuel gives less to mitigate at the stack.

It's just that - if you are unlucky enough to look at the source, the interaction of high intensity radiation with your eyes is perceived as blue. You wouldn't see it looking at objects within the shine without being in it yourself. You wouldn't see it with sufficient clear shielding, though that's not possible with any materials we know of, except water perhaps.

As a side note, high radiation levels degrade regular glass transparency quite quickly. When we used to specify remote cameras, everything had to be nuclear grade and have particularly pure glass so the lenses wouldn't cloud.

Both are useful nuggets for sci fi on radiation I would think.

It works quite well for sci fi that there's something called the blue beam of death. That unshielded shine directly from a high intensity radiological source, if one is unwise or unlucky enough to look at it, causes the human eye to perceive it as blue.

And when you see that blue - you're doomed.

I worked on nuclear waste remediation with some quite nasty tanks of stuff, and we considered shine from the tanks when they were opened. No worker or part of a worker could cross the shine from that opening.

If I recall the perception of blue came from some of the criticality accidents in the 40s and 50s, things involving the death of physicists, the demon core.

There's a lot to dive in to for sci fi in all that.

There are many parallels between drug resistant bacteria and herbicide resistant weeds, including population numbers and how resistance is gained and lost.

Since there isn't parallel gene flow in weeds, the answer hinges upon the question "does the resistance trait put the organism at a competitive disadvantage in the absence of the herbicide?"

If the answer is no, then the trait will persist for many generations, because there's no cost to keeping it, and plants like to keep many genetic pathways for handling threats - that's why their genome dwarfs ours.

If the answer is yes, then the trait will diminish at a rate dependent on how much a competitive disadvantage it puts them at relative to weeds without the trait.

So if it affects their water efficiency in a dry climate- it's going away quickly. But if the cost is minor, it will last longer.

It's not just that it's the best way, it's that it's the only way to practically extract a sizable portion of the energy produced.

The other capture options are generally effective on only a portion of the energy types released, and are often hindered by high heat.

Steam generation captures all the direct heat as well as any other energy forms such as light that resolve as heat. And convert that to electricity through one of mankind's most efficient machines, the turbine.

This is partially true. In recent years rain has become significantly less acidic, because the biggest contributor was sulfur from burning coal, and that's been reduced thru stack scrubbing and general replacement of coal.

It's not a minor effect. Sulfur is a necessary nutrient in plant growth, and quite a few farms that traditionally benefited from the contribution of acid rain now have to add it when fertilizing.

There was always a localized effect to it though. The UK had and has major problems with loss of peat in high moorland because of the steady deposition of acid rain on thin soils under a constant wind pattern. That land can only sustain peat and without it is subject to erosion.

For deeper soils on cropped agricultural land it's of benefit.

CO2 isn't nearly as significant at creating acid rain, since sulfuric acid is far more powerful than carbonic.

Not just trees. Grasslands as well. Which considering that includes both natural ones and man made ones via agriculture - that's a LOT of acres.

It's compounded by the seasonal cycles of tillage. Farmers tend to plow in the fall thru spring so that the old crops' plant matter will have decomposed by the time they need to plant again. That decomposition releases CO2.

But there's a cycle to it, and much will be reabsorbed once plant growth kicks back into high gear with spring's warmth.

A good question.

There's going to be a lot of variation in current vs pressure because there are 3 energy form changes (electric to mechanical to fluid flow) and many outside influences.

Starting with electrical- is the operating voltage 115V? Or is it 121V or only 109V because someone is running a toaster simultaneously on the same circuit? All those will effect current and yet have nothing to do with pressure.

Is the motor warmed up or in a cold room? The shaft and pump seals, how does temperature, mineral buildup etc effect them? How often does the operator clean the machine? Does the grind of the coffee or make of filter influence back pressure or temperature or something else? All this, and yet even if you figure all that out it will change as the parts wear over time.

So what you will run in to is that there are so many things that effect current that you will never be able to entirely trust it as a measurement for pressure.

So the best possible solution is the simplest - avoid all the guessing and go right to the thing you want to know. It also allows you to build a check into your system if you want - of actual known pressure.

That can be helpful for safeties, interlocks, warnings etc.

It's possible to calculate it, yes. But under most circumstances not with enough accuracy to use it as the control input. There's just too many variables.

What you really want to know is either flow or pressure, and measuring current is too far abstracted from that.

I can see wanting to use current in place of adding a flowmeter, but pressure transducers are cheap and super reliable, so if that's what you want to control for just measure it directly.