Can You Store Renewable Energy In A Big Pile Of Gravel?

December 4, 2019 by Lewin Day 117 Comments

As the world grapples with transitioning away from fossil fuels, engineers are hard at work to integrate new types of generation into the power grid. There’s plenty of challenges, particularly around the intermittent nature of many renewable energy sources. Energy storage projects are key to keeping the lights on round the clock, even when the wind isn’t blowing and the sun isn’t shining.

Conventional grid-level energy storage has long made use of pumped hydro installations where water is pumped uphill to a storage reservoir where it can later be used to run a generator. More recently, batteries are being used to do the job. When you consider the cost of these installations and their storage capacities, there is a gap between batteries and pumped hydro. A recently published whitepaper proposes Mountain Gravity Energy Storage — gravity-based energy storage using sand or gravel in mountainous areas — is the technology that can bridge the gap.

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Jonas Salk, Virologist And Vaccination Vanguard

December 3, 2019 by Kristina Panos 21 Comments

In the early 1950s, the only thing scarier than the threat of nuclear war was the annual return of polio — an easily-spread, incurable disease that causes nerve damage, paralysis, and sometimes death. At the first sign of an outbreak, public hot spots like theaters and swimming pools would close up immediately.

One of the worst polio epidemics in the United States struck in 1952, a few years into the postwar baby boom. Polio is more likely to infect children than adults, so the race to create a vaccine reached a fever pitch.

Most researchers were looking into live-virus vaccines, which had worked nicely for smallpox and rabies and become the standard approach. But Jonas Salk, a medical researcher and budding virologist, was keen on the idea of safer, killed-virus vaccines. He believed the same principle would work for polio, and he was right. Within a few years of developing his vaccine, the number of polio cases in the United States dropped from ~29,000 in 1955 to less than 6,000 in 1957. By 1979, polio had been eradicated in the US.

Jonas Salk is one of science’s folk heroes. The polio vaccine was actually his sophomore effort — he and Thomas Francis developed the first influenza vaccine in the 1940s. And he didn’t stop with polio, either. Toward the end of his life, Salk was working on an AIDS vaccine.

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How To Get Into Cars: Choosing Your First Project Car

December 2, 2019 by Lewin Day 75 Comments

The automobile is a wonderous invention, perhaps one of the most transformative of the 20th century. They’re machines that often inspire an all-consuming passion, capturing the heart with sights, sounds, and smells. However, for those who grew up isolated from car culture, it can be difficult to know how to approach cars as a hobby. If this sounds like you, fear not – this article is a crash course into getting your feet wet in the world of horsepower.

So You Like Cars, Eh?

Project cars let you do things that you’d never dare attempt in a daily.

The first step to becoming a true gearhead is identifying your specific passion. Car culture is a broad church, and what excites one enthusiast can be boring or even repulsive to another. Oftentimes, the interest can be spawned by a fond memory of a family member’s special ride, or a trip to a motor race during childhood.

Knowing what kind of cars you like is key to your journey. You might fall in love with classic American muscle and drag racing, or always fancied yourself in the seat of a tweaked-out tuner car a la The Fast And The Furious. Movies, posters, magazines, and your local car shows are a great way to figure out what excites you about cars. Once you’ve got an idea of what you like, it’s time to start thinking about picking out your first project car. Continue reading “How To Get Into Cars: Choosing Your First Project Car” →

The Young Engineers Guide To University Capstone Projects

November 26, 2019 by Lewin Day 8 Comments

Engineering degrees are as wide and varied as the potential careers on offer out in the real world. There’s plenty of maths to learn, and a cavalcade of tough topics, from thermodynamics to fluid mechanics. However, the real challenge is the capstone project. Generally taking place in the senior year of a four-year degree, it’s a chance for students to apply everything they’ve learned on a real-world engineering project.

Known for endless late nights and the gruelling effort required, it’s an challenge that is revered beforehand, and boasted about after the fact. During the project, everyone is usually far too busy to talk about it. My experience was very much along these lines, when I undertook the Submarine That Can Fly project back in 2012. The project taught me a lot about engineering, in a way that solving problems out of textbooks never could. What follows are some of the lessons I picked up along the way. Continue reading “The Young Engineers Guide To University Capstone Projects” →

The Strain Of Flu Shot Logistics

November 26, 2019 by Kristina Panos 43 Comments

Did you get a flu shot this year? How about last year? In a world of next-day delivery and instant downloads, making the yearly pilgrimage to the doctor or the minute clinic feels like an outdated concept. Even if you get your shots free at the office, it’s still a pain to have to get vaccinated every year.

Unfortunately, there’s really no other way to deal with the annual threat of influenza. There’s no single vaccine for the flu because there are multiple strains that are always mutating. Unlike other viruses with one-and-done vaccinations, influenza is a moving target. Developing, producing, and distributing millions of vaccines every year is a massive operation that never stops, or even slows down a little bit. It’s basically Santa Claus territory — if Santa Claus delivered us all from mass epidemics.

The numbers are staggering. For the 2018-19 season, as in last year, there were 169.1 million doses distributed in the United States, up from 155.3 million doses the year before. How do they do it? We’re gonna roll up our sleeves and take a stab at it.

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Tales From The Sysadmin: Dumped Into The Grub Command Line

November 25, 2019 by Jonathan Bennett 53 Comments

Today I have a tale of mystery, of horror, and of hope. The allure of a newer kernel and packages was too much to resist, so I found myself upgrading to Fedora 30. All the packages had downloaded, all that was left was to let DNF reboot the machine and install all the new packages. I started the process and meandered off to find a cup of coffee: black, and darker than the stain this line of work leaves on the soul. After enough time had elapsed, I returned, expecting the warming light of a newly upgraded desktop. Instead, all that greeted me was the harsh darkness of a grub command line. Something was amiss, and it was bad.

(An aside to the reader, I had this experience on two different machines, stemming from two different root problems. One was a wayward setting, and the other an unusual permissions problem.)

How does the fledgling Linux sysadmin recover from such a problem? The grub command line is an inscrutable mystery to the uninitiated, but once you understand the basics, it’s not terribly difficult to boot your system and try to restore the normal boot process. This depends on what has broken, of course. If the disk containing your root partition has crashed, then sorry, this article won’t help.

In order to get a system booting, what exactly needs to happen? How does booting Linux work, even? Two components need to be loaded into memory: the kernel, and the initramfs. Once these two elements are loaded into memory, grub performs a jump into the kernel code, which takes over and finishes the machine’s boot. There is one more important detail that we care about — the kernel needs to know where to find the root partition. This is typically part of the kernel parameters, specified on the kernel boot line.

When working with an unfamiliar shell, the help command is a good starting point. grub runs in a very limited environment, and running the help command scrolls most of the text off the screen. There is an environment variable that helps out here, enabling output paging:set pager=1.
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Ask Hackaday: Is Anyone Sad Phone VR Is Dead?

November 13, 2019 by Donald Papp 92 Comments

It’s official: smartphone-based VR is dead. The two big players in this space were Samsung Gear VR (powered by Oculus, which is owned by Facebook) and Google Daydream. Both have called it quits, with Google omitting support from their newer phones and Oculus confirming that the Gear VR has reached the end of its road. Things aren’t entirely shut down quite yet, but when it does it will sure leave a lot of empty headsets laying around. These things exist in the millions, but did anyone really use phone-based VR? Are any of you sad to see it go?

Google Cardboard, lowering cost and barrier to entry about as low as it could go.

In case you’re unfamiliar with phone-based VR, this is how it works: the user drops their smartphone into a headset, puts it on their head, and optionally uses a wireless controller to interact with things. The smartphone takes care of tracking motion and displaying 3D content while the headset itself takes care of the optics and holds everything in front of the user’s eyeballs. On the low end was Google Cardboard and on the higher end was Daydream and Gear VR. It works, and is both cheap and portable, so what happened?

In short, phone-based VR had constraints that limited just how far it could go when it came to delivering a VR experience, and these constraints kept it from being viable in the long run. Here are some of the reasons smartphone-based VR hit the end of the road: Continue reading “Ask Hackaday: Is Anyone Sad Phone VR Is Dead?” →