heat conductors

Culinary Technology (Part 8): The Aristocracy

Petworth House (Sussex) is one of the grandest houses in England.  It belonged to the Egremonts from 1150 (it is now managed by the National Trust).  The current building is from the 1600′s.

Today, it has an enormous array of kitchen utensils, over 100 pieces in total.  There are rows of saucepans and stewpans, with matching lids, lined up on dressers.  There are stockpots with taps at the bottom (like tea-urns), sauté pans and omelette pans, a large braising pan with an indented lid to hold embers (so the food could be cooked from above at the same time).

The Petworth batterie de cuisine.

Copper braising pan (front); small steaming kettle with handle cover (back).

Particulary impressive is the wide variety of fish pans.  In the old days, fish came from the Sussex coast.  The kitchen has fish kettles, with pierced draining-plates inside, so that the fish could be lifted from the water it was being poached in, without falling to pieces. There is a fish fryer (a round, open pan with a wire drainer), and a specialist turbot pan (diamond-shaped, the same shape as the fish). There are several smaller pans for cooking mackerel.

Victorian copper fish kettles.

A tin fish kettle (cheaper than copper).

Modern fish kettle, with a better view.

The fish fryer probably looked like this.

Turbot pan.

Of course, not all of these items would have been in use during every era.

In 1624 (during the Stuart era), Petworth didn’t have any saucepans or stewpans.  For boiling/stewing, they had a large fixed “copper” (a giant vat of boiling water, which supplied hot water for the whole household as well as the kitchen); nine stockpots (cauldrons), an iron cockle pan, a few fish kettles, and five small brass skillets (3-legged, to stand in the fire).

Modern stockpots.

A brass skillet - not sure of the era.

The kitchen’s focus was on roasting, not boiling.  They had 21 spits, 6 dripping pans, 3 basting ladles, and 5 gridirons.

Medieval spit.

Gridiron (not sure of the era).

Basting ladle (1745).

But by 1764 (in the Georgian Era), things were different.  Only 9/21 spits were left.  Petworth now had 24 large stewpans, 12 small stewpans, and 9 bain-maries & saucepans.

Modern stewpans.

Georgian saucepans.

This increase in pans (both number & variety) was because of a new style of cooking.  The old heavy medieval cuisine was on its way out, and a fresher, more “buttery” cuisine was on its way in. There were many new foods in the Georgian Era that the Stuart Era did not have.  For example: frothy chocolate; crisp biscuits; sharp, citrusy sauces; the truffly ragouts of French nouvelle cuisine.  And all of these new dishes needed new equipment to cook them in.

Hannah Glasse (1708-70) was one of the most well-known cookery writers of the 1700’s.  She wrote that it was important to use the right pan when melting butter – a silver pan was best, she thought. (A type of thickened melted butter was beginning to be served as a universal sauce, to go with meat or fish.)

But by 1869 (in the Victorian Era), this was definitely not enough. The focus of the kitchen was finally moving away from spit-roasting – now the most important equipment was the copper pans, resting on steam-heated hotplates.

There were three steamers, for those foods that needed gentler cooking than boiling.  The number of stewpans & saucepans had risen from 45 to 96.  This was because of the huge variety of sauces, glazes and garnishes that were part of Victorian cuisine.

There isn’t much difference between a saucepan and stewpan.  In the 1700’s, saucepans were smaller (like the left-hand one further up), suitable for furiously whisking sauces and gravies, after they’d been made in a stewpan, and sieved.  Stewpans were bigger, and had lids.  They could hold a lot of food, and they were the main pan for cooking the meal.  However, the saucepan eventually overtook the stewpan.

In 1844, Thomas Webster wrote in An Encyclopaedia of Domestic Economy that saucepans were “smaller round vessels for boiling, made with a single handle”, and that stewpans were made with a double handle (one on the lid, and one on the pan).  The metal of stewpans was thicker, and they had a more rounded base, which made them easier to clean.

(Nowadays, we don’t use the term “stewpan” – we say “saucepan” for pretty much every pan.)

The idea of the batterie de cuisine came out of the 1700’s.  It was the opposite idea of the one-pot cooking – you should have a certain pan/vessel for each component of the meal.  You can’t sauté in a slope-sided frying pan; you can’t fry in a straight-side sauté pan.  You need a turbot kettle for poaching fish.  You need the right tool for every job. This was influenced by France, and by the new professionalism of cooking during the 1700’s.

William Verrall (1715-61) was the chef & landlord of the White Hart Inn (Lewes, Sussex).  He disparaged cooks that tried to make do with “one poor solitary stewpan” and one frying-pan “black as my hat”.  He said that “a good dinner cannot be got up to look neat and pretty without proper utensils to work it in, such as neat stew-pans of several sizes” and various other things.  He tells of “half of a very grand dinner” being completely spoiled “by misplacing only one stew pan.”

This obsession with pans was partially because of the English copper industry. Prior to the 1700’s, copper had been imported from Sweden.  But in 1689, their monopoly had ended, and England’s production of copper increased greatly (especially from Bristol).  And of course, now it cost less – so cooks could have many copper pans.  The French word batterie actually means copper that has been battered into shape.  By the 1800′s, batterie de cuisine had become the universal term to refer to cooking equipment (excluding fixed objects such as the oven).

The Victorian copper batterie was the apogee of the history of pots and pans.  They were well-crafted, and made from high-quality metal; they were tailored to the specific requirements of cooking; and wealthy Victorians had huge kitchens, with many cooks.

Some have criticized the Victorians for boiling vegetables for too long, and reducing everything to a soupy mush.  Victorian and Regency-era recipes say to boil asparagus for 15-18min; broccoli for 20min; carrots for 45min to an hour!  But this actually made sense for the time, and didn’t actually wreck the vegetables.

William Kitchiner (author of The Cook’s Oracle) says to boil asparagus for 20-30min, which seems far too long to us. He also says, “Great care must be taken to watch the exact time of their becoming tender; take them up just at that instant, and they will have their true flavour and colour: a minute or two more boiling destroys both.”  We tend to boil asparagus as individual stalks, whereas he says to tie it in a bundle – which takes longer to cook. But there is a lot more to the long boiling times than that.

Recipe-writers in the 1800’s were very keen on cooking scientifically.  And the most important thing about boiling, they said, was that no matter how long you boil water for, it’ll never go above 100°C. This was noted by Robert Buchanan (an expert on fuel economy) in 1815, and cookbook-writers often quoted him on this.  What was the point of boiling things hard, when it doesn’t raise the temperature any more?  It was just a waste of fuel/energy.

William Kitchiner experimented with putting a thermometer in water “in that state which cooks call gentle simmering”.  At simmering-level, the water was also 100°C – the same as if it was boiling.  Logically speaking, it would be better to cook at a simmer, rather than a boil – same temperature, less fuel.

In 1868, Pierre Blot (Professor of Gastronomy at the New York Cooking Academy) criticized cooks & housewives who boiled “fast instead of slowly”.  “Set a small ocean of water on a brisk fire and boil something in it as fast as you can, you make as much steam but do not cook faster; the degree of heat being the same as if you were boiling slowly.”

Simmering instead of boiling is good for meat.  Kitchiner said, “The slower it boils, the tenderer, the plumper and whiter it will be.”  But for vegetables (except for potatoes), it takes ages – especially because Victorian cooks liked to cook things in the smallest pan possible.

Kitchiner said that the size of the boiling-pot should be proportional to what it will contain.  The reason for that, he continued, was that the larger the pot, the more space it took up on the fire, and the more water & fire was needed.  This is true.

The Victorians were partially right, and partially wrong.  It is true that boiling water won’t go above 100°C (unless under higher pressure, such as in a pressure cooker).  But temperature isn’t the only important factor.  Another factor is ebullition – how much boiling water bubbles.  Heat transfer is determined by the temperature difference between the food and the heat source (water).  Boiling water moves more chaotically, and transfers heat to the foot several times faster than simmering.  Also, heat transfer is faster when there is more water in the pan (in proportion to the food).  So Kitchiner’s small, simmering pot will take ages longer to cook than a modern-day large, boiling pot.

Another reason for the long cooking times was that Victorian vegetables were different from now – less tender.  Their asparagus was stalkier, and their carrots & greens were tougher.

Victorian pots and pans, despite their craftmanship and variety, had a big problem – their material.  Copper is a great heat conductor, second only to silver.  But when it comes into contact with food (particularly acidic foods) pure copper is poisonous.

Tin is neutral, and their copper pans were thinly lined with it.  Of course it wore down over time, exposing the copper beneath. Therefore, 1700’s & 1800’s recipe books often give the advice to “Let your pans be frequently retinned.”

But cooks probably put off retinning their pans as long as possible.  In fact, cooks who didn’t realize that the copper was poisonous used its “greening” powers, using unlined copper pans to pickle green walnuts and green gherkins.

anonymous asked:

Would you be able to tell me how long someone could survive trapped very close to fire (say, in a wood-burning oven) before being rescued?

Not very long, dearest Hansel. There are a few problems with this situation. I’m going to start off with some warnings, because some readers are sensitive to various topics, and burns are one of those things that make even my veteran ass cringe. So here we are:

CW: BURNS . CW: GORE . No images, but some nasty descriptions.

First, the air in ovens gets really, really hot. I know that sounds like a really stupid thing to say, because that’s the point of an oven, right? They get hot. But the human airway is designed to inhale gas at anywhere from about 0*F to about 120*F, give or take. Anything higher than that and you start to get inhalation burns.

Now, the nose is a pretty good tool. It’s designed to temperature-moderate and humidify air as it enters the nasal cavity and before it goes down to the delicate tissue of the airway itself. But it can only do so much to cool air.

Freakishly enough, there was a computer modeling of human airway burns at temperature done by some Cornell students, because of course there was. The full paper is here ( https://ecommons.cornell.edu/bitstream/handle/1813/7903/group1.pdf?sequence=1 ), but their conclusion was as follows, with the Kelvin-to-Fahrenheit conversions courtesy of Dr. Google:

We concluded that significant burn starts at around an inhalation air temperature of 358K (85ºC) (185ºF) over a period of 20 seconds. A person can ideally inhale air under 358K  (185ºF) for 20 seconds without sustaining significant tracheal tissue damage. From 358K to 368K (185-203ºF) , the burn increases dramatically at 40.464 mol/K.  For every degree K increase, there is a 40.464 mol increase in the extent of burn of the tracheal tissue. A person inhaling temperatures over 358K  (185ºF) over a period of at least 20 seconds will sustain tracheal tissue damage 

For whatever reason, their model was limited to only 20 seconds, which means that even if they were only in the oven for 20s, a character set to bake at  350ºF would still incur inhalation burns.

Why is that important? Because when the airway burns, the airway swells, and it’s possible for the airway to swell so much that it actually swells shut, and your character could die from the edema rather than from the actual thermal burns themselves. Basically, they burn until they swell until they suffocate until they die.

It’s also worth noting that a lot of the actual thermal damage from hot air burns is because of steam, not because of direct hot air; a character in a steamy environment is going to suffer a lot more burns, a lot faster, than a character in a dry environment, because water at the same temperature as air carries a lot more thermal energy that it absorbed in its change from water to steam. So if your Wicked Not-A-Witch (hey, I know a bunch of witches, including @scriptwitchcraft, they’re nice people, don’t judge) has decided to roast them it’s one story, but if it’s a braise kind of a deal or there’s already some broth in there, it’s much, much worse.

Now, part 2: the burns to the rest of the body.

Your character got shoved into an oven, Hansel-style. Respect. Gotta love the gingerbread.

But he’s not gonna just go in there and float, basking in hot air. He’s still subject to that cruel master of us all, gravity. That sucker’s gonna sit on something. And that something is  likely to be metal.

Metal is a terrific conductor of heat, which means it’s also a terrific conductor of burns, because burns are nothing more than heat transferring from something (oven) to something (your character). Any exposed skin in that oven will start to sear, almost immediately.

Now, clothing can be a pretty good contact insulator, especially cotton based items or natural materials, like leather or wool. But synthetics do terrible, terrible things at temperature, like melt and stick to skin, and melt into skin. They also burn and cause toxic byproducts in the air, which get into the lungs and can cause toxicity, though I’m not sure if there’s enough toxic byproduct in a shirt or jacket to cause cardiac arrest from toxic byproducts.

Either way, thermal burns are absolutely awful, and they’ll be almost instant-onset. Consider crawling into a small box, and then think about all the places you would touch that box–with your head, with your hands, your feet, your back, your elbows, your knees. These are all the places your character is likely to suffer burns, or would if they were naked; these are the places synthetic clothing will melt to them.

So the ultimate answer to your question, Anon, is that I have no idea where the survivability curve lies. But I know that a character who’s been thrown into an oven will likely have trouble breathing, will likely have severe burns all over their body, will likely have singed hair, and will likely be in the most excruciating agony you can imagine and then some.

If you choose to go this route, don’t forget that this person has lots of burns in lots of places, including their eyes, their nose, their throat, and their lungs. Don’t forget that they will need a lot of time to recover and a LOT of whatever kind of pain relief can be found, and their lives will still be miserable, especially if this is in the same timeframe as the Hansel and Gretel myth.

All in all, I can’t give you a recipe for a character surviving getting tossed in an oven. I can tell you that inside of 20 seconds their airway will start to burn, and that their burns will be worse if the environment is moist (ie if there’s water or broth in the oven). I can tell you that they’ll have burns all over. But as to an actual survivability chart, dearest Anon, I’m glad to say it doesn’t exist.

Best of luck with your story.

xoxo, Aunt Scripty

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Properties of Metals and How They Relate to the Paladins

I was inspired by my previous post about the metal names and I wanted to think about how their Japanese names and the metals related to the characters. The amazing @zo-cola helped with this and offered her opinions as well.

Disclaimer: What I have here is pulled off the Internet and is a quick summary of the metals. If something is wrong, I apologize.

Shiro: Shiro’s full name, Shirogane, means “silver”. Silver is known for how reflective and shiny it is, but the thing about silver is it can tarnish easily (coughcough), so you have to keep up on taking care of anything silver if you want it to stay shiny. Silver is also the best conductor of heat and electricity known, and can withstand extreme temperature changes.

Keith: Keith’s name in the GoLions version, Kogane, means “gold”. Gold is known for its rarity on earth and for being used in valuable objects like crowns. Interestingly enough, gold is very malleable and soft, barely harder than fingernails. Gold beaten into a fine sheet can reflect infrared light and is used in heat-resistance in space suits. Gold is also resistant to corruption and a good conductor.

Lance: Lance’s name in the GoLion version, Kurogane, means “steel”. Steel is an alloy made from carbon and iron and is known for its ability to be durable and flexible under pressure and be able to revert back to its original shape. Like the others, steel is a good conductor. Stainless steel is also known for being resistant to corruption.

Pidge: Pidge’s name in the GoLion version, Suzuishi, means “tin”. Tin is a silvery-white metal that can resist corrosion from many things and can be used as a protective coat for other metals. Like the other metals, tin is malleable. Tin can also conduct electricity and becomes a superconductor in very low temperatures.

Hunk: Hunk’s name in the GoLion version, Seido, means “bronze”. Bronze has a long, long history and is an alloy between copper and other metals, commonly tin. Bronze can be corrupted but it is usually only on the surface and the metal underneath is protected. Bronze is very conductive and has lower boiling points than other metals, but it’s weaker than steel. Bronze has a huge variety of uses and has remained in use for thousands of years.

(This makes me wonder if the creators took into account this when they were designing the characters…)

Zo also suggested other metals that would be good examples of the paladins and their qualities:

Copper: Keith would probably be most relatable to copper. Copper is soft, has high thermal & electrical conductivity, and forms really weak metallic bonds. Yes, that last part is intentional.

Platinum: Hunk needs to be platinum because this boy deserves nothing but the best. Platinum is one of the rarer elements found in the earth, making it extremely valuable. It is also one of the least reactive elements and is extremely resistant to corruption (which classifies it as a “noble metal”). It is more ductile than gold, silver or copper but is less malleable than gold.

pujari-wei-ratio  asked:

Could you by any chance post screenshots of the new Synthesis ingredient lists? (Chaff, Heat Sinks, Life Support etc) I'm very interested in knowing how much they're gonna cost as the Heat Sink synthesis might actually make SCBs a bit more usable now.

Sure thing, recipes are as follows:

Limpets:
Basic - 10 Tin + 10 Iron = 4 Limpets

Chaff:
Basic - 1 Compact Composites + 1 Filament Composites = ½ Supply
Standard - 2 Compact Composites + 1 Filament Composites + 1 Thermic Alloy = Full Resupply.
Premium - Same as Standard (Probably a bug) = Bonus +2 Second Duration

Heat Sinks:
Basic - 2 Basic Conductors + 2 Heat Conduction Wiring =½ Supply
Standard - Same As Basic + 2 Heat Exchangers = Full Resupply + 15% Heat Dissipation
Premium - Same As Standard + 1 Proto Heat Radiators = +30% Heat Dissipation

Life Support:
Basic - 2 Iron + 1 Nickel = Full Oxygen Supply

coffeefalcon-deactivated2017073  asked:

I hope you don't mind me asking, but if Magcargo's body temperature was as hot or hotter than the surface of the sun, wouldn't the general vicinity be completely vaporized? How to people survive being so close?

Good question! Short answer: heat takes time to transfer. If you place a pot of water on the stove, it’s not going to instantaneously boil. It takes a few minutes for it to warm up, as the heat from the stove transfers into the water.

In fact, heat transfer is a lot more complicated than just temperature. Different materials can speed up or slow down the process. A metal can of soda, for example, feels a lot colder than the liquid inside it, even though they are both at the same temperature. This is because metal is a conductor, it is better at transferring energy than the liquid is: and heat is just energy. When you touch the metal, the heat can transfer quickly, making it feel cold. When you touch the soda, the heat won’t transfer as quickly, so it doesn’t feel as cold. Conductors transfer heat more quickly than insulators. It takes a lot less time to warm up a piece of metal than it does to warm up the soda.

You’re a human, with a body temperature of about 97 degrees F (36 C). And yet, when the temperature of the air outside is 90 degrees F (32 C), it feels really hot outside, not cold. This has to do with heat transfer: the human body is constantly releasing heat, sure, but the hotter the air is, the less easily the air will accept your body heat from you. Since the air is hotter, it behaves less like the cold metal can and more like an insulator, so the heat is trapped in your body, can’t leave, so you feel hotter.

So it just really has to do with what Magcargo is made out of. Sure, it’s body temperature is reportedly 18,000 F (10,000 C). But it’s body is also exceptionally good at holding that heat inside of itself: it doesn’t release body heat like humans do, or if it does, it releases the heat very, very slowly: not fast enough to make any real impact on the environment around it. It is a snail, after all.

Doesn’t mean I’d recommend this, though.

At the very least, you should probably keep the hugs short. Hope that helps!

-Professor Julie

anonymous asked:

how do you choose a person to spend your entire life with?

George Eliot’s Middlemarch has one of the most frightening passages in literature. Eliot (who did the equivalent of doctoral study on Spinoza) is trying to bring out a point about what it’s like to be a mind in the world. She describes the concave steel mirrors that used to be placed behind candle flames to magnify their light. These mirrors would easily tarnish and had to be polished frequently. This polishing tended to make tiny, random and densely crisscrossed scratches on the surface of the steel. When the mirror was fitted to the candlestick, however, the light of the flame picked out only those scratches that happened to form concentric circles.

Eliot says that the flame is you, and that the illusion of concentric scratches is what happens to that you when it goes out into the world.

Everyone’s had this realization, usually when looking down on a city from the window of a tall building: ‘Holy shit! All those people have their own lives and every one of them is going well or badly and each life seems just as important to each person as mine does to me.’ But her point is not really about our egotism & the way it tends to dull our sensitivity to lives of others. Her point is really about the people who are the opposite of strangers. The terror bubbles up when you realize it’s precisely the people whom we’re closest to that are most strongly distorted by the self. In this way the people we love the most are transformed into golems of the mind’s own silt: You can imagine the minds of most people as a column of flame on which are focused the gazes of concentric ranks of creatures risen from this.

Our talent for instantaneously rendering the world into monsters who speak only what we would prefer to hear is one of love’s greatest dangers. There is a fatal tendency to fall in love with people who are nothing to you except their adoration of your best loved qualities. This is what you call falling in love when it’s a solution to the problem of being a self. These are the people who secretly look at their own reflection and at nothing deeper when they look in the eyes of the person with whom they’re exchanging vows. Loneliness dines on this gaze. 

If you dive away from the thoroughly empty symbolism of marriage and peer deep inside the wedding ring, it’s possible see a way out of this nightmare.

Metals are metals because of sharing. Metals are ductile, conductors of heat and electricity, by turns flexible or malleable or springy because of how they share electrons. Imagine that you’re inside that ring and standing on the surface of an atomic nucleus. The space above you is filled with electrons. Those closer to you tend to orbit. But beyond these there is an ocean in the sky. The furthest electrons are shared. These wander throughout the ring. They belong to no atom but they are the source of every trait the ring has. They fill the voids between the atoms of gold like the water in a pool and it is these who slosh back and forth when an electric current is applied. They were the lubricant that allowed the atoms to slide past one another when the jeweler sized the ring. It was this ocean of electrons that kept the molten gold from evaporating when the ring was cast. These traits do not emerge from some solid self, do not come from some permanent identity, but rather from the communal flow of particles which are the property of no one.

You are your corporeal self, just as the nucleus beneath your feet has a quantity of protons and neutrons, the numbers of which assign it a fixed identity on the periodic table, but everything else about that metal, about you, about me, has been an emanation of flow.

It’s time to spend the rest of your life with someone when you are no particular either in a community of two.

Cheap Graphene Reported From Laser Fired At Plastic

Scientists have come up with a cheap and easy way to make electronics and energy storage components out of the supermaterial graphene.

Researchers can now make the amazingly strong material that is an excellent heat and electricity conductor by firing a laser at cheap plastic sheets. The laser burns patterns into the polyimide polymer, which create microscopic interconnected flakes of the single-atom-thick sheets of bound carbon atoms. 

One of the chemists behind the material says the laser actually creates a hard foam of graphene flakes that remain connected to the plastic from which they are burned. The process can be done at room temperature and pressure, another important manufacturing advance.

Keep reading

6

The Future of Displays: Glowing Graphene

Did you see the news last week about an international group of scientists who made the world’s thinnest lightbulb out of the supermaterial graphene? Here’s what it actually looks like when you send a current through the atom-thick sheet of linked carbon atoms. 

The light created from electrically excited graphene is actually quite bright, stable and tunable, and the researchers think the material could be used to make atomically thin, flexible and transparent displays.

Keep reading

most of my commutes look like this.

when i am lucky enough to sit, everyone wants to sit next to me… why, you ask?  because i take up less room so everyone else gets more.  it is not fun.  

also.  it ASTOUNDS and horrifies me when i think about how well the human thigh conducts heat… even when they don’t touch me, i can feel heat radiating off my fellow commutes. hot hot hot.