We may be decades away from the flying warehouses Amazon wants to build, but the e-commerce giant is growing its shipping and distribution network in different ways. The company has just announced that it plans to build its first air cargo hub at Northern Kentucky Airport to house its current and future fleet of planes. It’s expected to cost Amazon over $1.5 billion in investment and might eventually have buildings and material-handling equipment. According to The Wall Street Journal, this move signifies that Amazon is "ramping up its expansion into transporting, sorting and delivering its own packages."
When the 2-million-square-foot hub opens, it will certainly reduce the e-retailer’s dependence on UPS and FedEx in the area. It will initially employ 2,000 people, but it could end up having more personnel. WSJ says Amazon’s end goal is to deliver packages for itself and other retailers — to ultimately become a legit courier and direct competitor to bigger companies like UPS. It helps that the cargo hub’s location is apparently within a couple of days’ drive from a densely populated area.
While Amazon doesn’t have a timeline for the air cargo hub yet, it has already begun working on its shipping freight endeavor. A WSJ report from a few days ago revealed that the company has been coordinating shipments of containers from China since October as a freight forwarder.
AT&T’s 5G wireless network just got much more tangible. The carrier has announced that its ultra-fast wireless will launch in two cities, Austin and Indianapolis, sometime later in 2017. And while it’s still early days, the company is confident enough to set some performance expectations. Initially, these 5G areas will deliver peak speeds of 400Mbps or better. And there’s definite room for it to grow — carrier aggregation and other techniques should push that to 1Gbps in "some areas" this year.
The rollout is part of a larger network platform upgrade, nicknamed Indigo, that promises to be more adaptable and responsive. It’ll put more of an emphasis on software-shaped networking (covering 75 percent of the network by 2020) and lean on technologies like machine learning. AT&T is even open-sourcing the code for its network’s orchestration platform, ECOMP.
Don’t expect to walk into a store and buy the 5G phone of your choosing once the service is ready. There’s still no 5G standard, for one thing. Also, new cellular wireless technology tends to launch with very limited hardware choices. Remember how Verizon launched LTE with a handful of bulky, compromised phones, and you were more likely to use it in modems and mobile routers? Expect a repeat. Until the technology has had time to mature, it’ll be more of a showcase for the network than a meaningful upgrade.
In today’s odd science news, researchers have shown that they can produce electricity by evaporating water from a chunk of soot. The research falls into the categoryÂ of systems that extract electricity from wasteenergy around usâ€”kind of like generating electricity from swaying buildings or powering your watch from your own movements. But this was a resultÂ that I did not expect.
The experiments that make up the new work are so simple that pretty much anyone can do themÂ themselves. Take a hydrocarbon of choice and set it on fire so that it burns with a yellow flame. Then hold a bit of glass in the flame so that it gets covered in soot. Afterward, expose the carbon to an atmospheric plasma. Tape some electrodes to the carbon and then lower it into some water.
The porous carbon drags water into itselfÂ through capillary forces, and whenÂ the water later evaporates from the carbon surface, electricity is generated. Not much, admittedly, at 53nW per square centimeter, but still enough to raise eyebrows.
It turns out that there is a commonly known mechanismÂ that could cause this effect. Water always has some ions in it, and as it flows, it drags these ions along.Â So you get an electric current associated with the flow of water. In this case, the flow is induced by evaporation, but you could get the same effect by making the water flow downward via gravity.
Oddly, however, that flowÂ isn’t generating most of the electricity. By controlling where the evaporation could take place and measuring the current due to flow only, the researchersÂ behind these experimentsÂ determined that the streaming water contributed about one-fifth of the total voltage.
Where doesÂ the rest come from?
It’sÂ pretty clear that the researchers themselves don’t really understand where the charge is coming from, but they’ve made every effort to eliminate possible systematic errors. They used a fan to change the rate of evaporation, which showed that the voltage varied with the evaporation rate. They opened and shut the container to start and stop evaporation, which switched the voltage on and off as well. They used deionized water for most experiments, but theyÂ performed some with varying amounts of salt to show that the current was not simply due to ion contamination.
The teamÂ ran the experiment for hours, showing that as long as there was water to evaporate, the carbon sheet produced a voltage. They also placed multiple electrodes at different heights in the carbon sheet, andÂ the voltage got progressively higher for electrodes higher on the carbon sheet. Current cut outÂ when electrodes were placedÂ beyond the height of the water column in the sheet.
So I’m pretty confident that the researchers are producing electricityâ€”they even powered a small LCD display. But I don’t understand why it works.
To explain the voltage, the researchers turned to the carbon surface. Carbon soot is pretty hydrophobic, meaning that it will repel water. So without modifying the surface, the water would not be drawn into the pores. By exposing the surface to a plasmaâ€”a plasma is a gas of ionized atoms and molecules, which are highly reactiveâ€”the researchers partially oxidize the surface, making it hydrophilic. The oxidized surface draws water in and provides a large surface from which itÂ can be evaporated.
The researchers computed how water sticks to the partially oxidized carbon surface. The surface, as it is produced in the experiment, is nearly impossible to model. Essentially, it’s a lot of tiny flakes of highly defective graphene, and the plasma produces a lot of partially oxidized carbon atoms in the graphene flakes. So the calculation was limited to a graphene sheet with a number of oxidized carbon atoms in the sheet, and the attachment of the water molecules to the carbon layer couldÂ thenÂ be modeled.
ThisÂ is all a bit artificial, but it provides a hint. It turns out that for every three water molecules, the graphene sheet donates two electrons. The presence of water definitely results in a charge imbalance across the water-carbon interface. AÂ charge separation across an interface sounds a bit like a fuel cell, where partial reactions are carried out on different electrodes, but this is not what is going on here. There are no reactions and nothing to drive a charge flow.
I wouldn’t expectÂ the water would carry its ill-gotten charges away when it evaporated, so I can’t see how that would induce a current flow either. Furthermore, evaporation removes energyâ€”the water absorbs energy to free itself from the surface and float awayâ€”so I’m a bit suspicious that it also generates energy in the form of a current.
The more I think about it, the stranger the results seem. The maximum current was measured to be 30nA per square centimeter. There are about 1015 carbon atoms per square centimeter (this is an underestimate because the surface is not flat). That comes in at about 100 carbon atoms per million that contribute an electron. You can also estimateÂ the charge generated per evaporated water molecule. At about room temperature, you can expect on the order of 1021 water molecules per square centimeter to leave the surface. So one charge is generated per billion or so water molecules.
The upshot is that if this result really is due to a surface reaction of some sort, then it is highly inefficient. But that doesn’t really matter at the moment (it may not even be a surface reaction, after all). What is important is that the researchers have confirmed electricity generation in a very simple system. The generationÂ may be due to some other effect like osmosis, a thermal gradient, or any number of other things. But it may also be possible to optimize this system to generate larger amounts of electricity. Even at low efficiencies, it might be enoughÂ to keep low-power devices chugging along in the background.