Science

1440 Articles

Better Battery Management Through Chemistry

October 7, 2019 by 33 Comments

The lead-acid rechargeable battery is a not-quite-modern marvel. Super reliable and easy to use, charging it is just a matter of applying a fixed voltage to it and waiting a while; eventually the battery is charged and stays topped off, and that’s it. Their ease is countered by their size, weight, energy density, and toxic materials.

The lithium battery is the new hotness, but their high energy density means a pretty small package that can get very angry and dangerous when mishandled. Academics have been searching for safer batteries, better charge management systems, and longer lasting battery formulations that can be recharged thousands of times, and a recent publication is generating a lot of excitement about it.

Consider the requirements for a battery cell in an electric car:

  • High energy density (Lots of power stored in a small size)
  • Quick charge ability
  • High discharge ability
  • MANY recharge cycles
  • Low self-discharge
  • Safe

Lithium ion batteries are the best option we have right now, but there are a variety of Li-ion chemistries, and depending on the expected use and balancing and charging, different chemistries can be optimized for different performance characteristics. There’s no perfect battery yet, and conflicting requirements mean that the battery market will likely always have some options.

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Darwin Approves: Berkeley Evolves Analog Design

September 27, 2019 by 6 Comments

Digital design is hard. But in the right environment, digital circuits are more forgiving than analog. That 3.3V signal coming out of the chip has to drop a lot along the way to not be a logic level at the destination. If you are trying to push the boundary then digital design has much of analog design, but mostly you get a bit of a pass on many things that plague analog designers. Berkeley’s AI research group has been experimenting with using deep learning to evolve analog IC design.

Analog ICs are plagued with noise sources and often don’t have the margins that digital circuit designers enjoy. According to the post by [Kourosh Hakhamaneshi], designers often build a few blocks and attempt to lay them out in a way that should work and meet other requirements. Then they employ simulation, make changes as required, and simulate again. Accurate simulations can be very time intensive. You can read the actual paper, too, should you want to dig into the details.

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Dealing With Invasive Species Through Robotics

September 24, 2019 by 23 Comments

Throughout its history, humankind’s travels have often brought unwelcome guests along for the ride, and sometimes introduced species into a new environment for a variety of reasons. These so-called invasive species are all too often responsible for widespread devastation in ecosystems, wiping out entire species and disrupting the natural balance. Now researchers are testing the use of robots for population control of these invasive species.

The mosquitofish is the target of current research by NYU Tandon School of Engineering and the University of Western Australia. Originally from parts of the US and Mexico, it was introduced elsewhere for mosquito control, including in Australia. There it has become a massive problem, destroying native species that used to eat mosquitoes. As a result the mosquito problem has actually worsened.

As the main issue with these invasive species is that they do not have any natural predators that might control their numbers, the researchers created robots which mimic the look and motion of natural predators. In the case of the mosquitofish the largemouth bass is its primary predator. The theory was that by exposing the mosquitofish to something that looks and moves just like one of these predator fish, they would exhibit the same kind of stress response.

So far laboratory tests under controlled condition have confirmed these expectations, with the mosquitofish displaying clear signs of stress upon exposure to the robotic largemouth bass. Even better, they displayed decreasing weight and were found to avoid potentially dangerous areas, indicating that instead of focusing on foraging, they were in survival mode. This should limit their environmental impact, including their ability to procreate.

Who knows, before long the surface waters of Australia may be home to the first robotic species of fish.

(Thanks, [Qes])

Moon Elevator Could Be Sooner Than You Think

September 19, 2019 by 56 Comments

The big expense in getting people to orbit or the moon or any other space destination is the cost of escaping the Earth’s gravity. One often-proposed solution involves building a giant space elevator from some point on the Earth to orbit. That sounds great, but the reality is the materials needed to make a giant stalk reaching from the ground to orbit don’t exist today. Cables or other structures for such an elevator would have to be so impossibly thick as to break under their own weight. However, a recent paper from a researcher at Cambridge and another at Columbia suggest that while you can’t build an elevator from the Earth’s surface to orbit, we may have the technology to build a tunnel that anchors on the moon and lets out in Earth’s orbit.

Before you dismiss the idea out of hand, have a look at the paper. A classic space elevator proposal has one point on Earth and the far end balanced with a counterweight keeping the cables under tension. The proposed lunar elevator would minimize these problems by having most of the bulk in space and on the moon.

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Black Hole Imaging Scientists Win 2020 Breakthrough Prize

September 15, 2019 by 6 Comments

Making a monumental scientific breakthrough is really kind of its own reward. Even so, it’s always nice to get extra recognition in the form of unexpected money. For the 347 scientists around the world who made history when they captured the first image of a black hole, the event itself is pretty sweet. The cake of notoriety recently gained some icing, because the group has been awarded a $3 million Breakthrough Prize.

The prize, known as “the Oscars of science”, was created eight years ago with the goal of furthering scientific advancements in the areas of physical science, mathematics, and life science. Created by tech investor Yuri Milner, the Breakthrough Prize is funded by other deep-pocketed notables like Sergey Brin and the Zuckerbergs. This year’s theme is “seeing the invisible”. Prizes will also be awarded for discoveries toward non-opioid pain relievers and the study of neuro-degenerative disorders.

Each of the black hole imaging scientists will receive $8,645.53 when the prize is awarded in a televised ceremony on November 3rd, which is going down at NASA’s Ames Research Center in Mountain View, CA. In lieu of parading all 347 scientists across the stage, [Shep Doeleman] of the Harvard-Smithsonian Center for Astrophysics and Director of the Event Horizon Telescope project, will accept the award on their behalf.

What exactly are black holes, and how did they come about? Explore their origins with [Will Sweatman] in this feature from 2018.

Black hole wire frame CC0 Public Domain via Phys.org

Black hole image via NASA

Building A Full-Fat Air Quality Monitor

September 3, 2019 by 13 Comments

Over the years many people have made an air quality monitor station, usually of some configuration which measures particulates (PM2.5 & PM10). Some will also measure ozone (O3), but very few will meet the requirements that will allow one to calculate the Air Quality Index (AQI) as used by the EPA and other organizations. [Ryan Kinnett]’s project is one of those AQI-capable stations.

The AQI requires the measurement of the aforementioned PM2.5 (µg/m3), PM10 (µg/m3) and O3 (ppb), but also CO (ppm), SO2 (ppb) and NO2 (ppb), all of which has to be done with specific sensitivities and tolerances. This means getting sensitive enough sensors that are also calibrated. [Ryan] found a company called Spec Sensors who sell sensors which are pretty much perfect for this goal.

Using Spec Sensor’s Ultra-Low Power Sensor Modules (ULPSM) for ozone, nitrogen-dioxide, carbon monoxide and sulfur dioxide, a BME280 for air temperature, pressure and relative humidity, as well as a Plantower PMS5003 laser particle counter and an ADS1115 ADC, a package was created that fit nicely alongside an ESP8266-based NodeMCU board, making for a convenient way to read out these sensors. The total one-off BOM cost is about $250.

The resulting data can be read out and the AQI calculated from them, giving the desired results. Originally [Ryan] had planned to take this sensor package along for a ride around Los Angeles, to get more AQI data than the EPA currently provides, but with the time it takes for the sensors to stabilize and average readings (1 hour) it would take a very long time to get the readings across a large area.

Ideally many of such nodes should be installed in the area, but this would be fairly costly, which raises for [Ryan] the question of how one could take this to the level of the Air Quality Citizen Science project in the LA area. Please leave your thoughts and any tips in the comments.

Stack Of Plant Saucers, Transformed Into Low Cost Solar Shield

September 1, 2019 by 12 Comments

For serious data collection with weather sensors, a solar shield is crucial. The shield protects temperature and humidity sensors from direct sunlight, as well as rain and other inclement weather, without interfering with their operation. [Mare] managed to create an economical and effective shield for under three euros in materials.

It began with a stack of plastic saucers intended for the bottom of plant pots. Each of these is a lot like a small plate, but with high sides that made them perfect for this application. [Mare] cut the bottom of each saucer out with a small CNC machine, but the cut isn’t critical and a hand tool could also be used.

Three threaded rods, nuts, and some plastic spacers between each saucer yields the assembly you see here. When mounted correctly, the sensors on the inside are protected from direct exposure to the elements while still allowing airflow. As a result, the readings are more accurate and stable, and the sensors last longer.

The top of the shield is the perfect place to mount a UV and ambient light sensor board, and [Mare] has a low-cost DIY solution for that too. The sensor board is covered by a clear glass dish on top that protects the board without interfering with readings, and an o-ring seals the gap.

3D printing is fantastic for creating useful components, and has been instrumental in past weather station builds, but projects like these show not everything needs to be (nor should be) 3D printed.