Inkjet Printing

Posted by PITHOCRATES - March 5th, 2014

Technology 101

A Sunday Afternoon on the Island of La Grande Jatte is similar to Ink Jet Printing

Stephen Sondheim and James Lapine created a musical based on the painting A Sunday Afternoon on the Island of La Grande Jatte by Georges Seurat.  Giving us Sunday in the Park with George.  Seurat used a technique called pointillism.  Where he painted dots of color.  Points.  Up close the eye saw only a mass of different colored dots.  But when you moved back from the painting the brain blended those dots together into an image.

This is the same technique our televisions use to recreate an image on the screen.  Using only the 3 primary colors of light.  Red, blue and green.  Different colors of phosphor are energized to glow.  Causing a combination of these three dots of phosphor to glow creates a pixel of color.  A screen full of different colored pixels creates an image.  It’s similar to inkjet printing.  Where a print head places dots of different colors on a piece of paper.  Much like George did in Sunday in the park with George.  Although an inkjet printer can do it faster.  And without destroying a relationship.

George painted one dot at a time.  So it took him a very long time to create an image.  —SPOILER ALERT—   So much time that Dot left him and had a baby with Louis the baker.  Leaving George alone.  A true suffering artist.  Who died young.  Never realizing that Dot’s baby was his.  Which gave us a second act.  A great musical.  With some of Sondheim’s best music and lyrics.  The original Broadway recording with Mandy Patinkin and Bernadette Peters should be in everyone’s collection.  Do yourself a favor and buy it.  Support the arts.  But I digress.

Droplets of Ink are shot out of the Print Head onto the Paper without any Physical Contact with the Paper

If you have a large art museum near where you live you can probably see a work of art done in the pointilism technique up close.  And if you do you’ll probably notice that the dots are rather big.  Unlike they are with an inkjet printer.  Where the dots are much smaller.  It’s the same technique.  Pointillism.  But it is much harder to see that with inkjet printing.  Why?

George painted with a paint brush.  And even when the bristles are smoothed into a point it’s still pretty thick.  And makes large dots.  An inkjet, on the other hand, doesn’t ‘brush’ on the ink.  It spits it on.  Droplets of ink are shot out of the print head, across an air-gap and onto the paper.  Without any physical contact.  The only physical contact with the paper is the roller that loads a sheet.  And the roller that advances the sheet.  While the print head glides above the paper.  Spitting droplets of ink.

Well, it doesn’t actually spit ink.  It boils it.  In the ink cartridge.  Which is a marvel of engineering.  For the ink cartridge not only contains the ink.  But it also contains the print head.  A few hundred holes where droplets of ink jet out of.  As well as a lot of copper etched circuits.  To take the information from the computer when printing a document.  And transferring it to the proper ink port.  Which are very, very tiny holes.  So tiny that the droplets they produce make for near photo-like quality compared to a pointillism painting.

The Ideal Gas Law tells us if we incrase the Temperature while holding the Volume Constant the Pressure Increases

The ideal gas law is PV = nRT.  Which can be solved such that P = nRT/V.  Where pressure (P) equals the chemical amount in moles (n) times the universal gas constant (R) times the temperature (T) divided by the volume (V).  A lot of information there.  But the only things we want to focus on are pressure, temperature and volume.  The ideal gas law tells us if we incrase the temperature while holding the volume constant the pressure increases.  Which is how inkjet printing works.

Each ink port has ink in it.  But the hole is so tiny that the ink in its normal state will not flow through it.  Because it’s too thick.  However, when you heat the ink to boil it into a vapor the pressure is so great that it pushes a droplet of ink out of the print head onto the paper to releive the pressure.  All of this happens in a fraction of a second in all of those hundreds of ink ports.  An electric circuit turns on.  Boils ink.  Forces out a droplet.  The electric circuit shusts off.  And the ink just used to print with is replaced with fresh ink.  Waiting for the next electric current to boil it.

Complex software and hardware to advance the paper and move the print head over the paper are all coordinated to place thousands of droplets of ink with each pass of the print head.  A black ink cartridge is used for text documents.  And a color ink cartridge (red, blue and yellow) is used to add color to a text document.  Or to print color images.  Doing the work of a thousand Georges.  Faster.  And with tinier dots.  So tiny that they are impossible to detect with the naked eye.  Unlike Seurat’s A Sunday Afternoon on the Island of La Grande Jatte.  But few printed items will look as good.

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Heat Transfer, Conduction, Convection, Radiation and Microwave Cooking

Posted by PITHOCRATES - September 4th, 2013

Technology 101

At the Atomic Level Vibrating Atoms create Heat

We make life comfortable and livable by transferring heat.  And by preventing the transfer of heat.  In fact, once we discovered how to make fire our understanding of heat transfer began and led to the modern life we know today.

At the atomic level heat is energy.  Vibrating atoms.  With electrons swirling around and jumping from one atom to another.  The more these atoms do this the hotter something is.  There is little atomic motion in ice.  And ice is very cold.  While there is a lot of motion in a pot of boiling water.  Which is why boiling water is very hot.

How do we get a pot of water to boil?  By transferring heat from a heat source.  A gas or electric burner.  This heat source is in contract with the pot.  The heat source agitates the atoms in the pot.  They begin to vibrate.  Causing the pot to heat up.  The water is in contact with the pot.  The agitated atoms in the pot agitate the atoms in the water.  Heating them up.  Giving us boiling water to cook with.  Or to make a winter’s day pleasant indoor.

Fin-Tube Heaters create a Rising Convection Current of Warm Air to Counter a Falling Cold Draft

If you touch a single-pane window in the winter in your house it feels very cold.  Cold outside air is in contact with the glass of the window.  Which slows the movement of the atoms.  Bringing the temperature down.  This cold temperature doesn’t conduct into the house.  The heat conducts out of the house.  Because there is no such thing as cold.  As cold is just the absence of heat.

The warm air inside the house comes in contact with the cold window.  Transferring heat from the air to the window.  The atoms in the air slow down.  The air cools down.  And falls.  This is the draft you feel at a closed window.  Cold air is heavier than warm air.  Which is why hot air rises.  And cold air falls.  As the cold air falls it pulls warmer air down in a draft.  Cooling it off.  Creating a convection current.

To keep buildings comfortable in the winter engineers design hot-water fin-tube heaters under each exterior window.  Gas burners heat up water piping inside a boiler.  The heat from the fire transfers heat to the boiler tubes.  Which transfers it to the water inside the tubes.  We then pump this heating hot water throughout the building.  As it enters a fin-tube heater under a window the hot water transfers heat to the heating hot water piping.  Attached to this piping are fins.  The heat transfers from the pipe to the fins.  Which heats the air in contact with these fins.  Hot air rises up and ‘washes’ the cold windows with warm air.  As it rises it pulls colder air up from the floor and through the heated fins.  Creating a convection current of warm air rising up to counter the falling cold draft.

Microwave Cooking won’t Sear Beef or Caramelize Onions like Conductive or Radiation Cooking

If you’ve ever waited for a ride outside an airport terminal on a cold winter’s day you’ve probably appreciated another type of heat transfer.  Radiation.  Outdoor curbside is open to the elements.  So you can’t heat the space.  Because there is no space.  Just a whole lot of outdoors.  But if you stand underneath a heater you feel toasty warm.  These are radiators.  A gas-fired or electric heating element that gets very, very hot.  So hot that energy radiates off of it.  Warming anything underneath it.  But if you step out from underneath you will feel cold.  It’s the same sitting around a campfire.  If you’re cold and wet you can sit by the fire and warm up in the fire’s radiation.  Move away from the fire, though, and you’re just cold and wet.

We use all these methods of heat transfer to cook our food.  Making life livable.  And enjoyable.  When we pan-fry we use conduction heating.  Transferring the heat from the burner to the pan to the food.  When we bake we use convection heating.  Transferring the heat from the burner to heat the air in the oven.  Which heats our food.  When we use the broiler we use radiation heating.  Using electric heating elements that glow red-hot, radiating energy into the food underneath them.  A convection oven adds a fan to an oven.  To blow heated air around our food.  Decreasing cooking time.

There’s one other cooking method.  One that is very common in many restaurants.  And in most homes.  But real chefs rarely use this method.  Microwaving.  With a microwave oven.  They’re great, convenient and fast but fine cooking isn’t about speed.  It’s about layering flavors and seasoning.  Which takes time.  Which you don’t get a lot of when a microwave begins vibrating the atoms in the water molecules in your food.   Which is how microwaves cook.  Cooking by vibrating atoms in your food brings temperatures up to serving temperatures.  Unlike conduction heating such as in pan-frying where we bring much higher temperatures into contact with our food.  Allowing us to sear beef and caramelize onions.  Something you can’t do in a microwave oven.  Which is why real chefs don’t use them.

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Carbon, Carbon Cycle, Crude Oil, Petroleum, Hydrocarbons, Oil Refinery, Cracking, Sweet Crude, Sour Crude, Gasoline and Diesel Engines

Posted by PITHOCRATES - April 25th, 2012

Technology 101

Crude Oil is made from Long Chains of Carbon Atoms Bonded Together with a lot of Hydrogen Atoms Attached Along the Way

Carbon.  It’s everywhere.  And in everything.  Like all matter it cannot be created.  Or destroyed.  It just changes.  As it creates the circle of life.  The carbon cycle.  Plants and trees absorb carbon out of the atmosphere.  And converts it into biomass.  Into wood.  And into animal food.  Where the digestive system converts it into carbon-based living flesh and blood.  That exhales carbon.  Plants absorb carbon and release oxygen.  Plants can’t grow without carbon.  And we can’t breathe without plants growing.  Carbon is constantly changing.  But never created.  Or destroyed.  From diamonds to pencils.  From sugar to carbonated soda.  From plastics to human beings.  It’s everywhere.  And everything.  Why, it’s life itself.

Carbon is a time traveler.  Carbon that once traveled through the atmosphere disappeared millions of years ago.  Buried underneath the surface of the earth.  Under intense heat and pressure.  Plankton and algae and other biomasses decayed until there was almost nothing left but carbon atoms.  Long chains of carbon atoms.  Forming great, restless pools of black goo beneath the surface.   Waiting for the modern world to arrive.  Waiting for the internal combustion engine.  The jet engine.  And plastics.  When they could be reborn.  And see the light of day again.

Crude oil.  Petroleum.  Black gold.  Texas tea.  Hydrocarbons.  Long chains of carbon atoms bonded together with a lot of hydrogen atoms attached along the way.  In the ground they’re mostly long chains.  When we get them above ground we can break those chains into different lengths.  And create many different things.  C16H34 (hexadecane).  C9H20 (nonane).  C8H18 (octane).  C7H16 (heptane).  C5H12 (pentane).  C4H10 (butane).  C6H6 (benzene).  CH4 (methane).  Some of these you may be familiar with.  Some you may not.  Methane is a flammable gas.  Hydrocarbon chains from pentane to octane make gasoline.  Hydrocarbon chains from nonane to hexadecane make diesel fuel, kerosene and jet fuel.  Chains with more carbon atoms make lubricants.  Chains with even more carbon atoms make asphalt.  While chains with 4 carbon atoms or less make gases.  All these things made from the same black goo.  A true marvel of Mother Nature.  Or God.  Depending on your inclination.

Older Coastal Refineries make more Expensive Gasoline than the Newer Refineries due to the Availability of Sweet versus Sour Crude

Another great carbon-based product it bourbon.  Made from a corn sour mash.  We heat this and the alcohol in it boils off.  That is, we distill it.  We run this gas through a coiling coil and it condenses back into a liquid.  And after a few more steps we get delicious bourbon whiskey.  Distilleries give tours.  If you get a chance you should take one.  You won’t get to sample any of the distilled spirits (insurance reasons).  But you will get a feel for what an oil refinery is.

An oil refinery works on the same principles.  Boil and condense.  And cracking.  Cracking those long hydrocarbon chains apart into all those different chains.  Long and small.  Into liquids and gases.  Even solid lubricants and asphalt.  All made possible because of their different boiling points.  The gases having lower boiling points.  The solids having higher boiling points.  And the liquids having boiling points somewhere in between.

Refineries are complex processing plants.  Not only because of all those different hydrocarbon chains.  But because of the crude oil introduced to these plants.  For there is light sweet crude.  And heavier sour crude.  The difference being the additional stuff that we need to remove.  Such as sulfur.  An environmental problem.  So we have to remove as much of it as possible during the refining process to meet EPA standards.  The sweet crudes are lower in sulfur.  Making them the crude of choice.  But this has also been the most popular crude through the years.  So its resources are dwindling.  Making it more expensive.  As are all the products refined from it.  Especially gasoline.  The more sour crudes have higher sulfur content.  And require more refining steps to remove that sulfur.  Which means additional refinery equipment.  So the older refineries that were refining the light sweet crude can’t refine the heavier sour crudes.  Which is why the refineries along the coasts make more expensive gasoline than the newer ones in the interior refining the heavier sour crudes.  Due to the availability of sweet crude versus sour crude.

The Modern World is brought to us by a Complex Economy which is brought to us by Petroleum

One of the main uses of refined crude oil is fuel for internal combustion engines.  In particular, gasoline engines and diesel engines.  Which are very similar.  The difference being the mode of ignition.  And, of course, the fuel.  Gasoline engines compress an air-fuel mixture in the cylinder.  At the top of the compression stroke a spark plug ignites this highly compressed and heated mixture.  Sending the piston down.  If the combustion occurs too early it could place undo stresses on the piston connecting rods and the crank shaft.  By trying to send the piston down when it was coming up.  Causing a knocking sound.  Which is a bad sound to hear.  And if you hear it you should probably make sure you’re using the right gasoline.  If you are you need to have you car serviced.  Because continued knocking may break something.  And if it does your engine will work no more.  So this is where octane comes in the blending of gasoline.  It’s expensive.  But the more of it in gasoline the higher the compression you can have.  And the less knocking.  Which is its only purpose.  It doesn’t give you any more power.  The higher compression does.  Which the higher octane allows.  Using the higher octane gas in a standard compression engine won’t do anything but waste your hard earned money.

And speaking of higher compression engines, that brings us to diesel engines.  Which are similar to gasoline engines only they operate under a higher compression.  And don’t use spark plugs.  These engines compress air only.  Which allows the higher compression without pre-ignition.  At the top of their compression stroke a fuel injector squirts diesel fuel into the hot compressed air where it combusts on contact.  Diesel fuel has a higher energy content than gasoline.  Meaning for the same volume of fuel diesel can take you further than gasoline.  Which is why trucks, locomotives and ships use diesel.  But diesel tends to pollute more.  The smell and the soot kept diesel out of our cars for a long time.  As well as the difficulty of starting in cold climates.  Advanced computer controlled systems have helped, though, and we’re seeing more diesel used in cars now.

The modern world is brought to us by a complex economy.  Where goods and raw materials traverse the globe.  To feed our industries.  And to ship our finished goods.  Which we put on trucks, trains, ships and airplanes.  None of which would be possible without a portable, stable, energy-dense fuel.  That only refined petroleum can give us.  It’s better than animal power.  Water power.  Wind power.  Or steam power.  For there is nothing that we can use in our trucks, trains, ships and airplanes other than refined petroleum products today that wouldn’t be a step backwards in our modern world.  Nothing.  Making petroleum truly a marvel of Mother Nature.  Or God.  Depending on your inclination.

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