NDB uses graphite nuclear reactor parts that have absorbed radiation from nuclear fuel rods and have themselves become radioactive

Thursday, September 10th, 2020

Nano-diamond self-charging batteries could disrupt energy as we know it;

NDB uses graphite nuclear reactor parts that have absorbed radiation from nuclear fuel rods and have themselves become radioactive. Untreated, it’s high-grade nuclear waste: dangerous, difficult and expensive to store, with a very long half-life.

This graphite is rich in the carbon-14 radioisotope, which undergoes beta decay into nitrogen, releasing an anti-neutrino and a beta decay electron in the process. NDB takes this graphite, purifies it and uses it to create tiny carbon-14 diamonds. The diamond structure acts as a semiconductor and heat sink, collecting the charge and transporting it out. Completely encasing the radioactive carbon-14 diamond is a layer of cheap, non-radioactive, lab-created carbon-12 diamond, which contains the energetic particles, prevents radiation leaks and acts as a super-hard protective and tamper-proof layer.

To create a battery cell, several layers of this nano-diamond material are stacked up and stored with a tiny integrated circuit board and a small supercapacitor to collect, store and instantly distribute the charge. NDB says it’ll conform to any shape or standard, including AA, AAA, 18650, 2170 or all manner of custom sizes.

(Hat tip to Hans G. Schantz.)

You used to be able to fly into a country on one name and have meetings in another

Monday, August 31st, 2020

Modern technology is putting an end to traditional spying:

The beginning of the CIA’s cover and tradecraft crisis dates back to at least February 2003, when a Muslim cleric known as Abu Omar disappeared off the street in Milan. He didn’t resurface until 2004, when he called his wife from Cairo to tell her about his kidnapping, detention and torture at the hands of the CIA.

Italian investigators, eager to get to the bottom of the audacious abduction on their streets, were later able to track a web of cellphones communicating only with each other in close proximity to the disappearance, leading them to a series of hotel bills, credit card statements and other identifying indicators, according to a 2007 investigation unveiled at an annual hacker conference in 2013. Italian authorities charged 23 Americans, including the CIA’s former Milan station chief, for their roles in the scheme — most in absentia.

While Omar was just one target of the CIA’s aggressive post-9/11 antiterrorism campaign, several former intelligence officials described the Milan operation’s aftermath as a “come to Jesus” moment that revealed just how vulnerable the agency’s operators were to technology. At the time, some undercover officials naively believed that methods like using potato chip bags would mask cellphone signals, and operatives were generally “freewheeling,” according to one former senior intelligence official. In the space of a few short years, the rapid advance of technology, including nascent international surveillance systems, increasingly endangered the CIA’s traditional human intelligence gathering.

Singapore was one example, recall three former intelligence officials. By the early 2000s, the agency ceased running certain types of operations in the Southeast Asian city-state, because of the sweeping digital surveillance there. The Singaporeans had developed a database that incorporated real-time flight, customs, hotel and taxicab data. If it took too long for a traveler to get from the airport to a hotel in a taxi, the anomaly would trigger an alert in Singaporean security systems. “If there was a gap, they’d go to the hotel, they could flip on the TVs and phones and monitor what was going on” in the room of the suspicious traveler, says the same former senior intelligence official. “They had everything so wired.”

“You used to be able to fly into a country on one name and have meetings in another,” recalls this person. “It limited a lot of capabilities.”

Those concerns spread to other places, like London, where CCTV cameras are omnipresent, and the United Arab Emirates, where facial recognition is ubiquitous at the airport. Today there are “about 30 countries” where CIA officers are no longer followed on the way to meetings because local governments no longer see the need, given that surveillance in those countries is so pervasive, said Dawn Meyerriecks, the CIA’s deputy director for science and technology, in a 2018 speech.

In the 2000s, the explosion in biometrics — such as fingerprints, facial recognition and iris scans — propelled the conversation forward, according to multiple former intelligence officials. U.S. intelligence agencies concluded that in many parts of the world, within a short time, all alias work would likely become impossible.

These fears were largely borne out, say former CIA officials — especially in “hard target” countries like China and Iran. But this trend also affected CIA operations in friendlier countries. By 2012, recalls one former official, some officers were temporarily forbidden to travel for missions in the European Union over fear of exposure, due to widespread sharing of airport biometric data between EU member states. “Facial recognition and biometrics make it very difficult to travel in alias,” says Mike Morell, former acting CIA director and host of the “Intelligence Matters” podcast.

The rise in popularity of consumer DNA kits, which allow people to send in samples of their own DNA, is a growing part of the biometrics problem. Even if an undercover operative hasn’t used a consumer DNA kit, it’s highly likely, say experts, that one of their close relatives has. The Pentagon’s Dec. 20 warning to members of the military not to use these kits appears to be partly in response to that threat.

Greg Hampikian, a biologist at Boise State University and a leading DNA expert, says that with the advent of commercial genetic databases, exposing a spy or other covert operative could be as easy as taking a saliva sample from a cigarette butt or a drinking cup. A suspicious foreign government could send the sample in and potentially find out if the person has been operating under an assumed name.

“It’s right out of a spy novel,” he says.

For spy services, biometric data has become a highly valued currency — leading to a widespread and ongoing campaign by the U.S. and its allies, as well as hostile states, to hack into biometric databases from important airports worldwide. The U.S. has spearheaded breaches of its own, successfully hacking biometric data from the Dubai and Abu Dhabi airports, says a former official. Stealing biometric databases is an attractive strategy for other countries as well. In one case, Chinese intelligence successfully hacked into the biometric data from Bangkok’s airport. “The Chinese have consistently extracted data from all the major transit hubs in the world,” says another former senior official.

Disabling location services on a mobile device does not turn off GPS, and does not significantly reduce the risk of location exposure

Thursday, August 27th, 2020

Location data can be extremely valuable, the National Security Agency notes, and must be protected:

Using a mobile device—even powering it on—exposes location data. Mobile devices inherently trust cellular networks and providers, and the cellular provider receives real-time location information for a mobile device every time it connects to the network. This means a provider can track users across a wide area. In some scenarios, such as 911 calls, this capability saves lives, whereas for personnel with location sensitivities, it may incur risks. If an adversary can influence or control the provider in some way, this location data may be compromised. Public news articles have reported that providers have been known to sell data, including near-real time location data, to third-parties [1].

Location data from a mobile device can be obtained even without provider cooperation. These devices transmit identifying information when connecting to cellular networks. Commercially available rogue base stations allow anyone in the local area to inexpensively and easily obtain real-time location data and track targets. This equipment is difficult to distinguish from legitimate equipment, and devices will automatically try to connect to it, if it is the strongest signal present [2].

Additionally, location data is stored on the mobile device. Past location information can be used to forecast future locations [3]. Other examples of risk exist: websites use browser fingerprinting to harvest location information [4], and WiFi access points and Bluetooth sensors can reveal location information [5].

A mobile device provides geolocation data as a service to apps. This is known as location services, and users can disable them in the settings of a device. Perhaps the most important thing to remember is that disabling location services on a mobile device does not turn off GPS, and does not significantly reduce the risk of location exposure. Disabling location services only limits access to GPS and location data by apps. It does not prevent the operating system from using location data or communicating that data to the network.

Also important to remember is that GPS is not the same as location services. Even if GPS and cellular data are unavailable, a mobile device calculates location using Wi-Fi and/or BT. Apps and websites can also use other sensor data (that does not require user permission) and web browser information to obtain or infer location information [6].

Even if cellular service is turned off on a mobile device, Wi-Fi and BT can be used to determine a user’s location. Inconspicuous equipment (e.g., wireless sniffers) can determine signal strength and calculate location, even when the user is not actively using the wireless services. Even if all wireless radios are disabled, numerous sensors on the device provide sufficient data to calculate location. Disabling BT completely may not be possible on some devices, even when a setting to disable BT exists. When communication is restored, saved information may be transmitted.

If a mobile device has been compromised, the user may no longer be able to trust the setting indicators. Detecting compromised mobile devices can be difficult or impossible; such devices may store or transmit location data even when location settings or all wireless capabilities have been disabled.

Magnetometer readings are much less easy to jam than GPS signaling

Tuesday, August 25th, 2020

The U.S. Air Force is looking into using Earth’s magnetic field as an alternative to GPS:

Magnetic fields emanating from the earth’s surface vary in intensity, just like topography, and so-called magnetic anomaly maps of those fields have existed for years. Back in 2017, Aaron Canciani, an assistant professor of electrical engineering at the Air Force Institute of Technology, set out to see if magnetic sensors (magnetometers) affixed to aircraft could measure the intensity of those magnetic fields and, thus, locate the plane based on where it was in relation to those “landmarks.” His paper (and this video) shows how to outfit a Cessna plane with magnetometers in the rear and the front. Forty flight-hours worth of data and a lot of work reducing noise from the readings proved the idea viable.

But swapping magnetic fields for GPS isn’t easy. Unlike a crisp clear signal from space, factors such as the electrical operations of the plane itself can interfere with a sensor’s ability to detect the strength of the field. This is where artificial intelligence comes in, canceling out the noise from the sensor readings to allow for a better signal and more accuracy.

Researchers in the Air Force’s-MIT Artificial Intelligence Accelerator. community, working with scientists at MIT, continued to work on the problem, publishing their own paper in July. They showed that magnetic field readings can be accurate to ten meters, only slightly inferior to GPS, which is accurate down to three meters. But magnetometer readings are much less easy to jam than GPS signaling. GPS readings rely on a signal sent along a specific wavelength across vast distances. Magnometers just have to read the magnetic environment around the vehicle.

We must be strong there just as we are on earth

Friday, August 21st, 2020

In June 1965, the Directorate of R&D of the Future Weapons Office in Rock Island, Illinois published The Meanderings of a Weapon Oriented Mind When Applied in a Vacuum Such as the Moon:

The purpose of this brochure is to stimulate the thinking of weapon people all the way from those who are responsible for the establishment of requirements, through those who are responsible for funding, to the weapon designer himself.

“If space is truly for peace,” it reads, “we must be strong there just as we are on earth.”

It presents early thoughts and then corrected thinking, like this:

Although the widely advertised temperature of from –250° to +250° F. are actualities on the moon, they are the approximate extremes reached on the surface at midday and midnight. (Days and nights are two weeks long.) The surface of the moon is a poor conductor of heat, consequently a little shade during the day and earth light during the night, plus  a reversible white and black umbrella may be sufficient to keep the temperature in the vicinity of the space suit within limits of from –65° to +125 to +160° F. Assuming a direct proportion to the reflecting area, earth light on the moon will be sixteen times greater than moonlight on the earth.

The discussion involves some calculations. A “5 to 95 percentile” man has an unrestricted maximum line of sight of from 1.4 to 1.6 miles on the moon, with its mean radius of 1080 miles:

Any object propelled horizontally from the shoulder of a man six feet tall (shoulder approximately 5 feet above the surface) would impact the surface after an uninterrupted flight of 2.73 times its velocity. For a velocity of 3000 ft/sec the impact point would be 8190 feet or about 2500 meters. [...] Therefore, the maximum range of a projected object at a velocity of 3000 ft/sec is about 320 miles when propelled at an angle of 45 degrees with the lunar surface. Its maximum ordinate is approximately 80 miles above the surface.

Orbital velocity at the moon’s surface is 5,600 feet per second — totally doable.

Pages 10–16 could have come from an early 1980s sci-fi roleplaying game:

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p14-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p15-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p16-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p17-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p18-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p19-normal

The-Meanderings-of-a-Weapon-Oriented-Mind-When-p20-normal

The flesh-head bolt cuts more than flesh

Friday, July 24th, 2020

Tod Cutler of Tod’s Workshop shot a medieval crossbow (350-lb draw weight) using three different bolt heads (needle bodkin, flesh head, plate-cutter), against three types of flexible medieval armor (gambeson, aketon, and mail):

(Tod and his friends previously showed that medieval longbow arrows explode on impact with a breastplate.)

Amazon is discontinuing the Kindle Cloud Reader

Monday, July 13th, 2020

If it’s true that Amazon is discontinuing the Kindle Cloud Reader, I will be sorely disappointed:

Over the course of the past week, Amazon has been pulling features away from it and it looks like it is on the verge of being discontinued.

We conducted a review a couple of weeks ago on the Kindle Cloud Reader, and since then, the navigation tabs to download ebooks from the Cloud have been removed. The only books you can read, are ones that have been previously downloaded, no new titles can be accessed. Ebooks from certain publishers with DRM cannot be opened anymore, even if you had previously downloaded them. There is a popup window that appears, notifying readers to download the Kindle app for iOS or Android. Amazon also pulled the ability to read books offline, you need a dedicated internet connection to read.

The Damascus-like sample was significantly stronger

Friday, June 26th, 2020

Damascus steel is practically synonymous with artisanal forgework, but a new study led by Philipp Kürnsteiner of the Max Planck Institute for Iron Research shows that it is possible to do something very similar with laser additive manufacturing:

Traditional folded steels combined two steels that varied by carbon content and in their microscale structure, which is controlled by how quickly it cools (by quenching). In this case, the researchers were using a nickel-titanium-iron alloy steel that works well with these 3D printing techniques, in which metal powder is fed onto the work surface and heated with a laser.

Rapid cooling of this steel also produces a crystalline form as in quenched high-carbon steels. But further heat treatment leads to the precipitation of microscopic nickel-titanium particles within the steel that greatly increase its hardness—a pricey material called “maraging steel.”

The team’s idea was to use the layer-by-layer printing process to manipulate the temperatures each layer experienced, alternating softer, more flexible layers with layers hardened by that precipitation process. While printing a cubic chunk of steel, they did this simply by turning the laser off for a couple minutes or so every few layers. The top layer would rapidly cool, converting to the desired crystalline form. Then, as additional layers were added on top, temperatures in the crystalline layer would cycle back up, inducing the precipitation of the nickel-titanium particles.

The first test piece was thrown under the microscope for an incredibly detailed analysis, including a close-enough look at the hard layers to see the precipitated particles. The researchers even atom mapped the layers to verify their composition. So the researchers were able to confirm that the process definitely accomplished what they were aiming for.

[...]

For comparison, they printed another block continuously, producing no hardened layers at all. Both were stretched until they fractured and failed.

The Damascus-like sample was significantly stronger, holding up to about 20 percent more stretching force. It didn’t reach the strength of a typical, traditionally made maraging steel, but the researchers note that this requires “a time-consuming and costly post-process ageing heat treatment.”

No man-made vehicle has ever presented such an awe-inspiring spectacle

Tuesday, June 16th, 2020

When Eisenhower’s Atoms for Peace program was considering a nuclear-powered cargo-passenger ship, Mechanix Illustrated suggested something even better, an Atoms-For-Peace dirigible. What could go wrong?

Unlike a ship, the dirigible moves in an aerial ocean that completely envelops our globe. Hence, it can display its wares anywhere on the face of the earth. Seas, mountains and deserts present no barrier. Neither, considering its mission of peaceful education, should national frontiers.

atoms_dirigible_0

A modern dirigible would be unique, the cynosure of all eyes. Unlike the ship, one-third of whose bulk is hidden by the water in which it rides, the dirigible discloses every inch of its dramatic size as it coasts along against the clear backdrop of the sky. The lower it flies, the more majestic it appears, as anyone who saw the Akron, Macon or Hindenburg will testify. No man-made vehicle has ever presented such an awe-inspiring spectacle as a giant airship breaking through a low-hanging cloud or cruising above the rooftops of a darkened city.

atoms_dirigible_1

Its effect upon the peoples of the world would be many times more potent than that of an ordinary-looking, seaborne freighter. The fact that the dirigible, traveling at relatively low speeds and altitudes, a silvery giant by day and dramatically illuminated at night, will be visible to practically everyone en route, makes it the perfect Atoms-For-Peace transport. It can show our flag in every nook and corner of the globe, scattering as it goes messages of good will in every literate dialect.

atoms_dirigible_3

I suppose that part’s true. What did they propose?

Magnesium, titanium and strong, lightweight Fiberglas promise greater ruggedness and durability with less poundage. This improved weight-strength ratio opens new possibilities to the dirigible engineer. For instance, the single, bottom-keel structure, an outgrowth of age-old surface ship design, might be augmented by external side and top “keels,” containing additional passenger accommodations. These extra stiffeners would vastly strengthen the airship longitudinally without too great a weight penalty.

atoms_dirigible_4

In place of the Akron and Macon pickup gear and airplane hangar, a modern helicopter landing pad and internal hangar deck might be installed atop the hull’s center section. Built in the form of a shock-absorbing elevator, the pad could lift the copter clear of the hull for take-off and after landing, lower it to the level of the protected hangar deck for the safe, comfortable unloading of passengers. This is merely a reversal of the earlier airplane setup with the added safety advantage that both copter and airship travel at the same speed. The copter could provide a ferry service en route and at points where it is inadvisable or impractical to land the airship.

atoms_dirigible_5

Another possibility is the development of water landing gear. A seagoing dirigible, embodying a water-tight hull and lower gas bag, was recently publicized in Germany. MI feels, however, that retractable pontoons of inflated rubber would prove lighter and more efficient. They need not be large, as airships can be trimmed so as to be almost weightless. Water, pumped up from the surface — using the hose gear long since perfected — would provide ballast to hold the ship down when anchored.

Due to the horsepower limitations of the early internal-combustion engines, dirigible designers have always had to install multiple power plants, scattered along the length of the ship. This has not proven too good an arrangement. In addition to difficulties in coordination, the propeller slip-streams have added to the skin friction of the hull with a consequent increase in drag. Modern research indicates that some form of dragless stern propulsion would better the airship’s efficiency and speed by as much as 15 per cent.

With this in mind, MI weighed the various power plant possibilities.

The final solution proved to be the easiest to apply and the one that offers the maximum advantages weight wise. This is a midship atomic steam plant using turbines to generate electricity. Comparatively lightweight wiring car ries the juice to the stern of the ship where an electric motor drives a huge, four-bladed, reversible propeller. To assist in landing and take-off maneuvers, ducted fans are mounted in gimbals in the forward and after stabilizers. These enable the skipper to move his ship up, down or at sidewise angles.

The fission plant is of the latest type, consisting of a central reactor contained within the core of a cylindrical heat-exchanger, the whole being enclosed in lightweight, laminated shielding. Its operation is simple. Steam, generated in the exchanger by the heat of fission, is ducted to twin turbine-generator installations set on either side of the reactor. Passing successively through high and low pressure turbines, the used steam is condensed and routed back to the heat exchanger in a closed system. The turbines drive twin generators and the electricity thus produced, passes into storage batteries. While heavier than a single installation, the duplicate turbine generators provide a safety factor, one being always available in the event of mechanical failure or repair work on the other.

This compact arrangement is mounted on a reinforced deck within the hull and may be readily reached from the exhibition hall directly below it. Galleries around the engine room permit visitors to inspect the unique plant without interference or danger to themselves. If the public exhibition is considered sufficiently important, a water shielded “fishbowl” type of reactor might be used. While heavier and less compact, it would provide a more impressive show.

The power plant used in the atomic submarine Nautilus weighed roughly three times as much as the entire Hindenburg. That seems like a stumbling block.

The flash of a circular mirror is visible to the naked eye for 10 miles for each inch of mirror diameter

Monday, June 15th, 2020

In a recent Jocko Podcast on the Boer War, he and Echo wondered aloud about how big a signal mirror would have to be to be seen at 40 miles. Not that big, it turns out:

Most heliographs were variants of the British Army Mance Mark V version (Fig.1). It used a mirror with a small unsilvered spot in the centre. The sender aligned the heliograph to the target by looking at the reflected target in the mirror and moving their head until the target was hidden by the unsilvered spot. Keeping their head still, they then adjusted the aiming rod so its cross wires bisected the target. They then turned up the sighting vane, which covered the cross wires with a diagram of a cross, and aligned the mirror with the tangent and elevation screws so the small shadow that was the reflection of the unsilvered spot hole was on the cross target. This indicated that the sunbeam was pointing at the target. The flashes were produced by a keying mechanism that tilted the mirror up a few degrees at the push of a lever at the back of the instrument. If the sun was in front of the sender, its rays were reflected directly from this mirror to the receiving station. If the sun was behind the sender, the sighting rod was replaced by a second mirror, to capture the sunlight from the main mirror and reflect it to the receiving station. The U. S. Signal Corps heliograph mirror did not tilt. This type produced flashes by a shutter mounted on a second tripod (Fig 4).

Heliograph

The heliograph had some great advantages. It allowed long distance communication without a fixed infrastructure, though it could also be linked to make a fixed network extending for hundreds of miles, as in the fort-to-fort network used for the Geronimo campaign. It was very portable, did not require any power source, and was relatively secure since it was invisible to those not near the axis of operation, and the beam was very narrow, spreading only 50 feet per mile of range. However, anyone in the beam with the correct knowledge could intercept signals without being detected. In the Boer War, where both sides used heliographs, tubes were sometimes used to decrease the dispersion of the beam. In some other circumstances, though, a narrow beam made it difficult to stay aligned with a moving target, as when communicating from shore to a moving ship, so the British issued a dispersing lens to broaden the heliograph beam from its natural diameter of 0.5 degrees to 15 degrees.

The range of a heliograph depends on the opacity of the air and the effective collecting area of the mirrors. Heliograph mirrors ranged from 1.5 inches to 12 inches or more. Stations at higher altitudes benefit from thinner, clearer air, and are required in any event for great ranges, to clear the curvature of the earth. A good approximation for ranges of 20–50 miles is that the flash of a circular mirror is visible to the naked eye for 10 miles for each inch of mirror diameter, and farther with a telescope. The world record distance was established by a detachment of U.S. signal sergeants by the inter-operation of stations on Mount Ellen, Utah, and Mount Uncompahgre, Colorado, 183 miles (295 km) apart on September 17, 1894, with Signal Corps heliographs carrying mirrors only 8 inches square.

A hot air balloon is almost entirely hot air

Tuesday, June 9th, 2020

hot air balloon is almost entirely hot air — even by mass:

Component Pounds Mass Fraction
Envelope 250
3.3%
Basket 140
1.9%
Burner 50
0.7%
Fuel Tanks 405
5.4%
Passengers 750
10.0%
Sub Total 1595
21.2%
Heated Air 5922
78.8%
Total 7517
100.0%

The air transport market requires both high specific power and high energy density

Sunday, June 7th, 2020

Existing lithium batteries have a low energy density, while existing fuel cells have low specific power. The air transport market requires both high specific power and high energy density:

Forecasting that suitable lithium battery technology might be as much as 15 years away, the HyPoint team began focusing its efforts on a fuel cell design specifically targeted at eVTOLs. To keep things lightweight, it would have to be an air-cooled design; liquid-cooled fuel cells, says Ivanenko, work well in the automotive world, but the associated coolant tanks and pumps add parasitic mass that literally isn’t going to fly in the aviation world.

But today’s available air-cooled fuel cells, he says, have limited power capacity and lifespan, and they only work in temperatures between -5 and 30 °C (23 and 86 °F). So the HyPoint team set out to develop something faster and hardier, and came up with what they call the “turbo air-cooled fuel cell.”

“We boost the power of the fuel cell stack by placing it inside an air duct, where pressurized, humidified and thermally stabilized air is circulated by fans,” says Ivanenko. “The compression of air is maintained about 3 bars inside by a compression system, and the air with reduced oxygen content is charged through a control valve, and replaced with fresh compressed air with normal oxygen content.”

The extra oxygen on the cathode side of the fuel cell stack, in conjunction with a new High Temperature Proton Exchange Membrane (HTPEM) technology HyPoint has developed, allows you to force three times as much hydrogen through the fuel cell as a traditional design, tripling its specific power output without adding any parasitic cooling mass that might weigh a VTOL aircraft down.

With the entire system taken into account, the HyPoint system delivers 2,000 watts of power per kilogram of mass. The best of the liquid-cooled fuel cells deliver between 150-800 W/kg, and other air-cooled fuel cells sit at about 800 W/kg.

The energy density of the full system comes in at around 960 Wh/kg, where lithium batteries typically sit at about a third of that figure and other air- and liquid-cooled fuel cell systems come in a little over half – all according to HyPoint’s own figures.

The system has some other huge benefits as well, says Ivanenko; it accepts “dirty” hydrogen that’s only 99 percent pure, which is a fraction of the cost of the 99.999 percent purified hydrogen you need for an LPTEM system. “That’s a huge decrease in a significant operational parameter for a commercial eVTOL operation,” he adds.

It works at more or less any real-world temperature, from -50 to +50 °C (-58 to 122 °F) and beyond. And while it’s still in the lab at this stage, the team projects these fuel cells will last some 20,000 hours without maintenance, where LTPEM systems typically last around 5,000 hours – another very significant factor for a commercial operator.

California trash-to-hydrogen plant promises dirt-cheap, super-green H2

Monday, June 1st, 2020

Lancaster, California will be home to a “greener than green” trash-to-hydrogen production plant three times the size of any other green H2 facility:

SGH2 says its process is the cleanest of all on the market, while matching the price of the cheapest producers — and pulling tens of thousands of tons of garbage out of landfills.

[...]

According to a recent memorandum of understanding, the city of Lancaster will host and co-own the SGH2 Lancaster plant, which will be capable of producing up to 11,000 kg of H2 per day, or 3.8 million kg per year, while processing up to 42,000 tons of recycled waste per year. Garbage to clean fuel, with a US$2.1 to $3.2 million saving on landfill costs per year as a sweetener.

[...]

The process, developed by SGH2′s parent company Solena, uses high-temperature plasma torches putting out temperatures between 3,500 and 4,000 °C (6,332 to 7,232 °F). This ionic heat, with oxygen-enriched gas fed in, catalyzes a “complete molecular dissociation of all hydrocarbons” in whatever fuel you’ve fed in, and as it rises and begins to cool, it forms “a very high quality, hydrogen-rich bio-syngas free of tar, soot and heavy metals.”

The process accepts a wide variety of waste sources, including paper, old tires, textiles, and notably plastics, which it can handle very efficiently without toxic by-products. The bio-syngas exits the top of a plenum chamber, and is sent to a cooling chamber, followed by a pair of acid scrubbers to remove particulate matter.

A centrifugal compressor further cleans the gas stream, leaving a mixture of hydrogen, carbon monoxide and carbon dioxide. This is run through a water-gas shift reactor that adds water vapor and converts the carbon monoxide to carbon dioxide and more hydrogen gas. The two are separated, neatly capturing all the CO2 as hydrogen comes out the other end.

A Berkeley Lab lifecycle carbon analysis concluded, says SGH2, that each ton of hydrogen produced by this process reduces emissions by between 23 and 31 tons of CO2 equivalent — presumably counting emissions that would be created if the garbage was burned instead of converted into hydrogen. That would be between 13–19 tons more carbon dioxide avoided than any other green hydrogen production process.

What’s more, while electrolysis requires some 62 kWh of energy to produce one kilogram of hydrogen, the Solena process is energy-positive, generating 1.8 kWh per kg of hydrogen, meaning the plant generates its own electricity and doesn’t require external power input.

The 5-acre facility, in a heavy industrial zone of Lancaster, will employ 35 people full-time and create some 600 jobs in construction. SGH2 is hoping to break ground in Q1 2021 and achieve full operational status by 2023. The company is in negotiations with “California’s largest owners and operators of hydrogen refueling stations” to buy the plant’s entire output for a 10-year period.

Heaviside can take advantage of slim and low-drag aerodynamic forms that are just not practical on cars

Thursday, May 28th, 2020

Electric vertical takeoff and landing (eVTOL) aircraft can be surprisingly energy-efficient:

Under the EPA’s standard freeway driving test, a 2020 Nissan Leaf Plus uses about 275 Watt-hours per mile when it averages 50 miles per hour. It can comfortably seat four, but its average occupancy is somewhere around 1.6. Thus, the Leaf’s energy consumption is about 171Wh per passenger mile across all trips.

Our current Heaviside prototype uses about 120Wh per passenger mile, and does so at twice the speed of the Leaf: 100 miles per hour (of course, we can fly much faster, if we choose). We can save another 15% of energy because while roads are not straight, flight paths usually are. All together, Heaviside requires 61% as much energy to go a mile.

Why is Heaviside this efficient — doesn’t it take more energy to go faster? Yes, and it makes the high efficiency we’ve achieved even more dramatic. The answer is that Heaviside can take advantage of slim and low-drag aerodynamic forms that are just not practical on cars.

Detonation is chaotic and much harder to control

Wednesday, May 27th, 2020

A type of rocket engine once thought impossible has just been fired up in the lab:

Engineers have built and successfully tested what is known as a rotating detonation engine, which generates thrust via a self-sustaining wave of detonations that travel around a circular channel.

As this engine requires far less fuel than the combustion engines currently used to power rockets, it could eventually mean a more efficient and much lighter means of getting our ships into space.

“The study presents, for the first time, experimental evidence of a safe and functioning hydrogen and oxygen propellant detonation in a rotating detonation rocket engine,” said aerospace engineer Kareem Ahmed of the University of Central Florida.

The idea of the rotating detonation engine goes back to the 1950s. It consists of a ring-shaped — annular — thrust chamber created by two cylinders of different diameters stacked inside one another, creating a gap in between.

Gas fuel and oxidiser are then injected into this chamber through small holes and ignited. This creates the first detonation, which produces a supersonic shockwave that bounces around the chamber. That shockwave ignites the next detonation, which ignites the next, and so forth, producing an ongoing supersonic shockwave to generate thrust.

This should produce more energy for less fuel compared to combustion, which is why the US Military is investigating and funding it; this new research was funded by the US Air Force, and it’s not the only such project the military are looking into.

In practice, however, there’s a reason rockets are generally powered by internal combustion instead, in which the fuel and oxidiser are mixed to produce a slower, controlled reaction to generate thrust.

Detonation is chaotic and much harder to control. In order for the whole thing to not blow up — very literally — in your face, everything needs to be precisely calibrated.

(Hat tip to Hans Schantz.)