This is neat: microbial fuel cells

Hello and welcome to the second installment of the cool stuff I saw at the National Association of Science Writers conference.

Dr. Bruce Logan of Penn State University is seeking to address two global problems at once.  One of these problems should be pretty familiar: we need new and better sources of energy.  The other problem is one that you probably don’t think about much.  The treatment of wastewater has a high energy cost.  In the United States, 1.5% of all our energy consumption goes to wastewater treatment alone.

Dr. Logan hopes to turn wastewater around into a potential energy source.  Wastewater is literally full of crap, but the cellulose and other organic molecules in it contain energy in their chemical bonds that bacteria can digest.  If we can get bacteria to digest organic matter in the right environment, we can harvest electricity from the chemical bonds at the same time that the water is being purified.

The self-contained units that Dr. Logan and his team build to house the bacteria are microbial fuel cells.

The basics of the microbial fuel cell

The microbial fuel cell contains two chambers that are each filled with water.  The membrane that separates the two chambers only allows ions to pass through.  This prevents charge from building up when electrical current is passing through the system.  A metal wire runs from one chamber into the other.

Step one:  Collect a sample of bacteria from a wastewater treatment plant.  Put the bacteria, along with some “fuel,” into one chamber.

Step two:  Seal the chamber with the bacteria off from the air.  When bacteria digest organic molecules, they strip electrons off of them.  Eventually, these electrons have to go somewhere.  Oxygen will take the electrons if oxygen is around, but if there is no oxygen in the chamber, the bacteria are forced to dump the electrons into the wire.

Step three:  At the other end of the wire, the electrons combine with oxygen and protons to form water.  Now electrons are continuously passing through the wire.  Current!  You can hook an electric-powered device up to the wire and it will run.

Benchtop versions of these microbial fuel cells already work.  Click here to watch a video of a microbial fuel cell running a fan.  And here, you can learn more about the Logan lab’s work.

The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making, by Catherynne M. Valente

Wow.

I first discovered Catherynne M. Valente through a short story on the Internet that I cannot, for the life of me, find anymore.  It was a story about a demonness who got kicked out of Hell and plopped into New England long before any European settlers arrived there.  Since she’d been Hell’s baker before, she plies her trade with the mortals as the continent industrializes around her.

The story was dark and complex, just the way I like them.  It’s kind of like Gormenghast, the original Grimm’s tales before they got bowdlerized, and Gothic horror.  So I decided to pick up Valente’s latest novel, The Girl Who Circumnavigated Fairyland in a Ship of Her Own Making.  It’s a quick read.

At first I thought, oh, okay, Valente’s taking a break from her dark stuff to write a fluffy book.  The story starts off with a girl named September, who grows bored with her life in Omaha, Nebraska and gets whisked off to Fairyland on a green wind.  Hijinks ensue as she makes friends with a Wyverary and a Marid and gets tasked with stealing a spoon from an evil Marquess.  But then the story gets darker, and darker, until you realize that it’s not a fluffy book at all.  I won’t tell you the kicker of an ending, but I’ll share with you my favorite passage from the book:

Of course not.  No one is chosen.  Not ever.  Not in the real world.  You chose to climb out of your window and ride on a Leopard.  You chose to trade your shadow for a child’s life.  You chose not to let the Marquess hurt your friends – you chose to smash her cages!  You chose to face your own death, not to balk at a great sea to cross and no ship to cross it in.  And twice now, you have chosen not to go home when you might have, if only you abandoned your friends.  You are not the chosen one, September.  Fairyland did not choose you – you chose yourself.  You could have had a lovely holiday in Fairyland and never met the Marquess, never worried yourself with local politics, had a romp with a few brownies and gone home with enough memories for a lifetime’s worth of novels.  But you didn’t.  You chose.  You chose it all.  Just like you chose your path on the beach: to lose your heart is not a path for the faint and fainting.

This is neat: 3D printing makes replacement bones

At the National Association of Science Writers conference last October, I got to listen to a number of scientists give talks about the coolest things that are going on in their fields today.  One of these cool, cool scientists is Dr. Ola Harrysson, an associate professor of industrial and systems engineering at North Carolina State University.  He’s teamed up with Dr. Denis Marcellin-Little of the veterinary school at NC State to engineer better bone prostheses for pets.

One of the reasons owners come to Harrysson and Marcellin-Little is when a beloved pet gets osteosarcoma, a cancer of the bone.  Veterinarians can receive the diseased bone and save the pet’s life, but the limb with the missing bone is now useless.

For example, this is Cyrano, a cat who lost part of his knee to osteosarcoma.  He received a knee replacement from the team in 2012.

Image taken by Allen Breed. Courtesy of Yahoo news.

First, the team takes a CT scan of the affected limb.  Using computer aided design, they create a 3D model of what a bone prosthetic to fill in the gap would look like.

In the old days, the metal alloy used to make the prosthetic would then have to be cast or wrought into the precise shape needed for the final product.  Metal casting and working are extremely expensive when the final product has a complex shape, such as a bone prosthetic, and only one of the product will ever be needed.

That’s where Harrysson’s engineering expertise comes into play.  Harrysson collaborates with the company Arcam AB, which developed a rapid-prototyping machine (commonly known as 3D printing) that can work with molten metal.  First, a layer of powdered metal alloy is spread out on a surface.  The rapid-prototyping machine uses the data from the computer aided design program to selectively fuse regions of the powdered metal with an electron beam.  Then another layer of powdered metal is spread on top of the surface and the process repeats.

The machine builds up layer after layer of fused-together metal until the bone prosthetic is complete.

Here’s what the machine looks like:

From Arcam AB’s website.

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Here’s a model of Cyrano’s new knee.  That’s Dr. Marcellin-Little in the foreground.

Image courtesy of NC State University website.

The prosthetic is then implanted into the pet.  Because the edges of the prosthetic are porous, bone cells grow into the gaps and the prosthetic ultimately fuses with the animal’s own bones.

Dr. Harrysson and Dr. Marcellin-Little have given bone prosthetics to eight animals so far.  Now that he has received the knee replacement, Cyrano’s prognosis is excellent.

Here’s a link to NC State’s page about the work.

Persimmon Refrigerator Jam

In honor of Thanksgiving, here’s a spicy, orangey-brown, autumnal recipe for you.

Like many new recipes, this one started with the question, “What do I do with all these x?”  Persimmons, in this case.  I’d happened on three Fuyu persimmons in a mixed bag of fruit and I had no idea what to do with them.  To me, they taste too sweet to eat fresh.  Jam, maybe?

Many people shy away from making jams and jellies because the canning process is difficult and requires specialized equipment.  But here’s the thing: making the jam itself is dead easy, and if you’re willing to keep the jam in the refrigerator and eat it up quickly, you don’t have to can it.  Really.  This recipe is easy.

Persimmon Refrigerator Jam

  • Three persimmons
  • Three overripe pears
  • Juice from 1/4 of a lemon
  • 1/3 cup of brown sugar
  • Cinnamon and clove to taste

Here’s what the fruits looked like.

Closeup of a persimmon’s insides.

Wash the persimmons and pears, then remove the stems from the persimmons and the cores from the pears.  Chop each fruit roughly into 5-6 pieces.  Put them into a slow cooker.

Add all the other ingredients, then not quite enough water to cover.  Cook on the slow cooker on low.  Stir every couple of hours and mash fruit down with a potato masher.

The jam should be done in about eight hours.  (Told you it was easy.)

The finished product.

The Eleventh Plague by Jeff Hirsch

Hello, everyone.  Today Carrie Slager from The Mad Reviewer is doing a guest post on The Eleventh Plague by Jeff Hirsch.

(Cover picture courtesy of Midnight Bloom Reads.)

Sometimes the only way to survive is to keep moving.  America is a vast, desolate landscape left ravaged after a brutal war.  Two-thirds of the population are dead from a vicious strain of influenza.  People called the sickness the eleventh plague.

Fifteen-year-old Stephen Quinn was born after the war and only knows the life of a salvager.  His family was among the few who survived and look to roaming the country in search of material to trade.  But when Stephen’s grandfather dies and his father falls into a coma after an accident, Stephen finds his way to Settler’s Landing, a community that seems too good to be true.  There Stephen meets Jenny, who refuses to accept things as they are.  When they play a prank that goes horribly wrong, chaos erupts, and they find themselves in the midst of a battle that will change Settler’s Landing—and their lives—forever.

I know what you’re thinking: male protagonist + mysterious plague = zombies.  That’s what I thought too, but I was mercifully wrong.  It’s not that I don’t like zombies, but they are definitely overused.

The Eleventh Plague is different from a lot of the speculative YA you see on the shelves right now.  The biggest difference is that there’s a male protagonist, but there are more subtle differences as well.  Jeff Hirsch has actually paid attention to world politics and invented a plausible scenario for how the plague started and why civilization in America is basically non-existent in his novel.  He shows us how some people adapt well to the new world where the only skills that matter are survival skills, but he also shows us people like Isherwood Williams from Earth Abides who try to keep civilization alive by educating the next generation.  It’s an interesting contrast and the main character Stephen is torn between both sides.  On one hand he loves reading, but on the other his grandfather told him repeatedly that it was useless and a waste of time.

Stephen is a great character readers can sympathize with.  He’s tough and goes through a lot during the course of the novel, but he also has a more tender side which we see when he falls in love with Jenny.  For those of you already cringing at the mention of yet another teenage romance, never fear!  It is not the focus of the novel and it certainly is unconventional.  Jenny is also an excellent character in her own right and although she may seem like the typical tough rebel at first, her backstory makes her personality a lot more believable.

I wouldn’t call the plot of The Eleventh Plague on-the-edge-of-your-seat thrilling, but it does move along quite nicely and Jeff Hirsch never got bogged down in excessive descriptions.  It has some great plot twists and the ending isn’t exactly happy, but it’s not tragic either.  Some say the ending isn’t satisfying at all but I liked it because it stayed true to the characters.  That, for me at least, is far more important than a fairytale ending.

I give this book 4.5/5 stars.

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Kale Chips

It’s November in Minnesota and it’s getting flipping cold outside.  (Highs in the 40’s Fahrenheit, that is.)  It makes me want to eat lots of hot soups, root vegetables … and kale.  Kale looks intimidating in the grocery store because the leaves feel like they’re as tough as a leather suitcase.  Not to fear!  If you bake kale in the oven, it will come out crispy and not tough at all.

You will need:

  • Two baking sheets.
  • One bunch of kale.
  • 3-4 tablespoons olive oil.
  • 3-4 teaspoons salt.
  • 1/2 cup Parmesan cheese.

Preheat the oven to 350°.  Grab the bunch of kale by the stem.

Rip pieces off of the leaves.  Keep going until you’re down to the midribs.

Rinse the kale pieces in a strainer and blot dry.  Add the oil, salt, and Parmesan and toss it like a salad.  Spread the mixture out evenly on the two baking sheets.

Bake the kale in the oven for 12 minutes.  They will come out looking like this:

The picture doesn’t really convey it, but these are delicious.  They taste like fresh, hot potato chips that happen to be green.

Back from NASW Trip

Traveling home from the National Association of Science Writers meeting today felt strange.  The airports were half-empty from all the cancelled flights into and out of New England.  I’m fortunate that I didn’t have to go anywhere near Hurricane Sandy to get to Minneapolis, but still.  Eugh.

As I’m sitting here fighting off sleep so I can get back onto Central time, I thought I’d share with you some pictures from the trip.

The first thing you see when you get out of the terminal at Raleigh-Durham Airport is a full-wall mosaic of various cereal crops.  The Triangle Park region, where the meeting was held, is home to a cluster of important ag-biotech companies.

Sir Walter Scott in a labcoat.  He’s standing outside the convention center where we held our meeting.

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National Association of Science Writers 2012

This week I’ll be traveling to the National Association of Science Writers’ annual conference in Research Triangle Park.

The National Association of Science Writers is a trade organization for science journalists, university public information officers, and scientists with an interest in communicating to the public.  The conference is going to run from October 26th to the 30th and will include workshops on writing craft and the latest developments in science.  Expect to see photos when I get back!