Refrigerator

Scientists 3D Printed Cheese

These days, you can 3D print anything from a house to your breakfast. And as 3D-printed pizza becomes a thing, food scientists are examining what exactly happens when you print yourself some cheese.

A recent study in the Journal of Food Engineering explores how 3D printing affects the structure of processed cheese. How gross would 3D-printed Velveeta nachos be? A bevy of researchers from University College Cork in Ireland decided to find out.

They melted a commercially available processed cheese (think American cheese, not cheddar) and put it through a modified 3D printer that printed the cheese out at either a fast or a slow speed. The cheese was printed out into cylinders that were then cooled for 30 minutes and put in the refrigerator for a day. After that 24-hour refrigeration period, the researchers took the cheese out of the fridge to check its texture and chemical structure.

How to chill an object by sending its heat into space

solar panels
solar panels

When a refrigerator cools your food, it takes the heat away and dumps it into your kitchen. That adds to your home’s cooling bills. Likewise, when your air conditioner cools your home, it sends that heat outdoors. It also makes things warmer for everyone else in your neighborhood. The farther away you can send heat, the better. And there’s not much farther you can send it than outer space. Now, researchers have built a device to do just that. It cools down an object by radiating its heat directly into space.

For now, the device isn’t too practical. But its designers say that such cooling methods, combined with other techniques, might one day help people get rid of unwanted heat. The device would be especially well suited for arid regions, they add.

Radiation is the means by which electromagnetic waves carry energy from one place to another. This energy might be starlight traveling through space. Or it could be the heat of a campfire warming your hands.

The bigger the temperature difference between two objects, the quicker that heat energy can radiate between them. And not many things are colder than outer space, notes Zhen Chen. He’s a mechanical engineer at Stanford University in Palo Alto, Calif.

Outside of the envelope of gases surrounding Earth — our atmosphere — the average temperature of space is about –270° Celsius (–454° Fahrenheit). Chen and his team wondered if they could take advantage of this big temperature difference between Earth’s surface and outer space to cool an object on Earth, using radiation.

For an object on Earth to shed energy to space, radiation must travel through the atmosphere. The atmosphere doesn’t let all wavelengths of radiation through, Chen points out. But certain energy wavelengths can escape with little resistance.

One of the atmosphere’s clearest “windows” is for wavelengths between 8 and 13 micrometers. (At these wavelengths, electromagnetic radiation is invisible to the human eye. Because their energy is lower than that of red light, these wavelengths are called infrared.) Fortunately, says Chen, objects at about 27 °C (80.6 °F) radiate much of their energy in just that window.

Building a heat-emitting device

To study the new concept, Chen’s team built an object they would try to cool. They used mostly silicon. The basic ingredient in beach sand, silicon is both cheap and sturdy. It’s also the material computer chips are made from. That meant Chen’s team could use the same techniques used in making computer chips.

selective emitter
In a new cooling device, a shiny layer of aluminum (bright layer at bottom) and a coating of silicon nitride (top surface) help radiate heat from a layer of silicon (middle) into space.

The base of their object was a super-thin disk of silicon, about twice the thickness of a human hair. That layer was for structural support. To that, they added a thin layer of aluminum. It reflected light waves like the shiny layer on the back of a glass mirror. The aluminum layer would send the object’s heat upward, toward space.

Next, the researchers added the layer of material they wanted to cool. It, too, was made of silicon, but was much thinner than the base layer. It was just 700 nanometers — billionths of…

Get to Know Rose Totino, Patron Genius of Frozen Pizza

We don’t like to presume, but the chances are fairly good that you have a pizza in your freezer right now. After all, roughly two-thirds of all American households have at least one frozen pizza lurking in their freezer, according to industry reports, and sales of frozen and refrigerated pizza top more than $5.5 billion each year, shifting upwards of 350 million pies annually.

And you’ve really got one woman to thank for that: Rose Totino, the apple-cheeked second-generation Italian nonna with a serious head for business.

Rose Totino née Cruciani was born in 1915, the fourth of seven children; her parents had come to America from Italy just five years before, in 1910. She grew up in the Northeast neighborhood of Minneapolis, Minnesota, a lively European immigrant community, in a house with chickens and a sustenance garden in the backyard. Like other children in poor families, she started working at an early age, before leaving school at 16 to take a job cleaning houses for $2.50 a week. But even as a teenager, Rose had spirit: According to one story, retold in the Twin Cities Daily Planet, she took on Minneapolis Mayor George Leach to get her father’s city job back after he’d been fired for not being a “full-fledged citizen”.

Her life changed when she attended a dance party at the Viking Dance Hall in Minneapolis. It was there that Rose met Jim, a baker with, like Rose, no more than a 10th grade education. When they started courting, she was earning 37 cents an hour at a local candy factory, but Rose left work when the couple married in 1934. Two daughters soon followed and the Totinos settled into domestic life. Rose became a den mother to a Cub Scout troop, often treating the boys to little homemade pies topped with cinnamon and sugar, and volunteered at her daughters’ school, joining the PTA. Through the 1940s, she frequently attended PTA meetings armed with what soon became her famous pizzas, delicious pies topped with sausage, cheese and fresh sauces, the kinds of pies that she’d grown up eating herself.

Sugary pies for small boys and hearty Italian fare for PTA meetings soon turned into catering events for friends and acquaintances; as word got out about the Totinos’ fantastic cooking, more and more people told them that they really ought to open a restaurant. So they did. By the 1950s, when the Totinos began exploring the idea of starting their own restaurant, pizza had already been in American for at least 50 years, carried over with the waves of Italian immigrants. But it had also stayed largely in Italian communities and in cities such as New York and Chicago; for most of America, pizza was still new, exotic fare that appealed to an increasing interest in “ethnic” cuisine. And in Minnesota, people had barely even heard of pizza – the story goes that when the Totinos applied to the bank for a loan (using their car as collateral), the members of the loan committee had no idea what pizza was, let alone why you’d want to open a restaurant to serve it. So Rose baked them a pie – and got the $1,500 loan they needed to open Totino’s Italian Kitchen.

Rose and Jim opened the restaurant, then a take-out only establishment in 1951 at Central and East Hennepin Avenue, in the Northeast community they’d grown up in. Rose had figured that selling 25 pizzas per week would just about cover the rent, but within three weeks, the Totinos were making enough for Jim to quit his regular job as a baker and go into the pizza business full time. Jim made the crusts, Rose handled the toppings and sauce, and everything went into their custom brick ovens.

The Totinos sometimes worked as long as 18 hours a day, so exhausted at the end of the night that they barely had the energy to stuff their earned bills into…