How It Works: The Highest-Efficiency Solar Cell

 Solar cells typically convert no more than 20 percent of incoming energy into electricity, in part because they capture only certain wavelengths of light. Researchers at Germany’s Fraunhofer Institute for Solar Energy Systems have developed a solar cell that converts 44.7 percent—a new record. It consists of a lens that concentrates sunlight onto four stacked subcells, each designed to absorb a distinct portion of the spectrum. The team estimates it will take them another two to three years to scale up the 5.2-millimeter prototype for use in solar-power plants.

1. Sunlight passes through a multifaceted lens known as a Fresnel. The lens focuses direct sunlight, delivering the power equivalent of 297 suns to the solar cell below.
2. The first subcell, made from gallium indium phosphide, captures photons from the shortest wavelengths of light. The subcells beneath it contain elements capable of capturing progressively longer wavelengths.
3. Each subcell consists of several semiconductor layers, which create an electric field. As photons enter, they excite electrons, freeing them from the subcell.
4. Once the freed electrons reach the top of the stack, a metal contact funnels them toward an output terminal as a direct current.

Read More

Blackmagic Introduces New Ultra HD Film and Studio Cameras

A digital film camera, a studio camera, new mini converters and switchers and a film scanner are among the new products that are available from Blackmagic Design this year.

In the usual Blackmagic Design fashion, the slew of new products all hit bright and early and drawing the most attention was the Blackmagic URSA camera. A high end digital film camera, the URSA was designed in response to Blackmagic's observation that people were using their cinema cameras in a way they hadn't expected.

"Over the last few years it's been really amazing to watch some of the work being done on our cinema camera and some of the rigs that have been built around it. But when we designed it we never really thought it would be used on such large jobs," said Grant Petty, CEO of Blackmagic Design. Seeing how users were tricking out their small intimate cameras with loads of gear to get them to do the jobs they wanted to use the camera on, they decided to incorporate it into a full camera -- no need to rig it up the same way. "People don't want lego for adults," Petty said of the URSA. People add to the camera because they want to use it for the picture quality first, but within their needs.

The URSA includes an upgradable Super 35 4K image sensor with global shutter, 12G-SDI connections, XLR audio inputs with phantom power and dual CFast based RAW and ProRes recorders. The camera runs at 60 fps, but the cooling and processing can allow it to run beyond 100 fps when faster sensors are available.

The camera was designed so that multiple crew members can work around the aluminum body in separate workstation areas for DP, camera assist, and audio engineers. On the DP station is a ten inch fold out on set monitor, along with a 5 inch screen for settings and built-in scopes. The camera assist station features another LCD for camera settings, status, and scopes, and the audio station has audio meters, controls, and connections. Altogether, there are three LCDs in the camera.

The sensor and lens mount can unbolt from the front and be remove or replaced altogether. In the future when new sensors are available, they can be swapped out.

There are three models available initially, one with an EF lens mount and the other with a PL mount. An URSA is also available without a lens and sensor, with threaded holes and an HDMI input where the sensor would normally be so you can put any camera on the front and get all the benefits of the body.

Another addition to the Blackmagic Design camera family is a Studio Camera. Fitting into a need for the live production world, Petty called it "the world's smallest workhorse camera with the world's largest viewfinder." With the bright ten inch screen (bright enough for outside -- "we kept running outside to check it in sunlight," Petty added), the Studio camera also has a 4 hour battery, talkback, tally indicators, balanced XLR phantom powered microphone connections and built in optical fiber and SDI connections that allow you to connect to a live production switcher with one cable.

The Studio Camera has an active Micro Four Thirds mount that is compatible with a wide range of lenses and adapters, so you can use photo lenses or broadcast ENG lenses depending on your needs. It also has a color corrector built into the camera. DaVinci Resolve's primary color corrector can be used remotely from an ATEM switcher.

DaVinci Resolve 11 added some major updates to the free and full versions of the software, including over 70 new editing features like dynamic JKL trimming, audio crossfades, and customizable keyboard shortcuts. The new spline curve keyframe editor is integrated into the edit timeline. And with collaborative timelines in Resolve, editors and colorists can work on the same timeline from multiple workstations. There are color correction updates too -- new color grading controls that are designed for photographers who are moving into cinematography.

The most curious addition to Blackmagic product line is the Cintel Film Scanner. Blackmagic's reason for purchasing Cintel: content can be created by shooting it or through live productions, but it also already exists in the millions of hours of 35mm film in vaults. For decades, the film and television industry has generated Ultra HD without even thinking about it since film is essentially 4K.

Joking a bit about the nerd quotient of adding such a scanner to the product line, Dan May, president of Blackmagic Design North America, said "We have lots of 35 mm film out there, and that's Ultra HD, natively. How do I get all my Seinfeld episodes into Ultra HD?"

The very thin film scanner (which can be wall mounted!) scans 35mm and 16mm negate and positive film in real time over Thunderbolt 2. It was designed in mind to keep engineers out of the picture, so it can be plugged in and run from a Mac.

In addition to these products, the ATEM camera control got a free update to allow full control of the new Blackmagic Studio Camera from any ATEM production switcher; the ATEM 2 M/E Production Studio 4K replaces the older switcher with a smaller size and more inputs and processing features; the Smart Videohub 12 x 12 and Smart Videohub 20 x 20 are the latest routers, based on 6G-SDI technology; several new Mini Converters now have 6G-SDI and Ultra HD abilities; and the Teranex Express includes the first 12G-SDI connections so you can up and down convert between SD, HD, and Ultra HD video standards.

Blackmagic Design continues to bring price points down and introduce new products that were previously new within reach for many people. May added that "It's the spirit of, 'I want to make this product, I want to empower people, I want to get it out there', this is not the elite club....We work hard to make these products affordable, easy to use, and accessible to people."

Read More

How It Works: An Electronic Cigarette

Since electronic cigarettes hit the market in 2007, yearly sales have reached $1 billion in the U.S. Although they’re popular, it’s still unclear how safe they are. Last year, a study from an international group of scientists showed that the toxins in e-cigarette vapor are 9 to 450 times lower than in tobacco smoke. The Food and Drug Administration is still determining its regulatory stance. It’s sponsoring more research while sorting out its position.

A. LED

When the e-cigarette is active, an indicator light glows like a tobacco ember.

B. Sensor

Some versions have a pressure sensor that detects the airflow of an inhalation. The sensor then turns on the battery, which triggers the heating element. Other e-cigarettes are turned on and off with a button.

C. Battery

A slim lithium-ion battery, usually rechargeable, provides the power. An average e-cigarette has about 300 puffs per charge.

D. Heating Element

Electricity passes through a resistant material—usually metal or ceramic—which produces heat. Once the heating element reaches approximately 150°F, it vaporizes about 0.005 milliliters of the nicotine liquid into a mist. Each hit has roughly 90 percent of the nicotine found in a tobacco-cigarette puff.

E. Nicotine Liquid

A viscous fluid made from propylene glycol, vegetable glycerin, or a mixture of both, contains about 1 percent nicotine and flavoring such as menthol, fruit, or classic tobacco.

F. Mouthpiece

A flexible tip, sometimes made of silicone, evokes the feel of a real cigarette.

Read More

A one-wheeled electric motorcycle

A one-wheeled electric motorcycle

 

 

The future has arrived – and it's on one wheel. Check out the video above of the Ryno bike: a one-wheeled, electric-powered motorcycle created by Chris Hoffmann. The Ryno was based off a sketch by Hoffmann's daughter who saw something like the vehicle in a video game. With 15 years of auto industry engineering experience, Hoffmann got busy building the very first Ryno.
Six years and three prototypes later, the Ryno travels at speeds up to 10 MPH and can travel up to 10 miles on a fully charged battery. The bike weights 160 pounds and can carry up to 260 pounds with its custom steel frame. LED headlights ensure riders can see where they're going and others in cars or on bikes can see the rider.
Last week, Hoffmann came into the Popular Science office and brought with him the Ryno. A couple of us rode it around the halls of our floor, people pulling off their headphones and peeking behind corners to see what was going on. It felt a little weird getting on the Ryno at first – there's no gas pedal or normal brake. You propel it by leaning forward and go reverse by leaning back. To steer, it's more about rotating the hips than twisting the handlebars. Hoffmann guided me on my first couple of rides down the hallways, kind of like learning how to ride a bike. But once I got the hang of it, I pretty much felt like I was riding a motorcycle owned by the Red Power Ranger.
Hoffmann's first-year plan is to have a limited amount of bikes sold by five dealers, and begin shipping on April 16. The Ryno bike will be priced at about $5,300. Check out more details about the motorcycle on its website. 

Read More