BLOGS

Cool stuff: the diagram shows how the temperature of the caloric material was measured. The plot in the center shows the temperature change in the sample when exposed to a magnetic field. The plot on the right shows the change in temperature when the sample is strained. (Courtesy: Peng Wu et al/Acta Materialia 237 118154)

Topics: Global Warming, Green Tech, Materials Science, Solid-State Physics, Thermodynamics

Researchers in China have shown that applying strain to a composite material using an electric field induces a large and reversible caloric effect. This novel way of enhancing the caloric effect without a magnetic field could open new avenues of solid-state cooling and lead to more energy-efficient and lighter refrigerators.

The International Institute of Refrigeration estimates that 20% of all electricity used globally is expended on vapor-compression refrigeration – which is the technology used in conventional refrigerators and air conditioners. What is more, the refrigerants used in these systems are powerful greenhouse gases that contribute significantly to global warming. As a result, scientists are trying to develop more environmentally friendly refrigeration systems.

Cooling systems can also be made from completely solid-state systems, but these cannot currently compete with vapor compression for most mainstream applications. Today, most commercial solid-state cooling systems use the Peltier effect, which is a thermoelectric process that suffers from high cost and low efficiency.

Solid-state cooling is achieved via electric field-induced strain, Hardepinder Singh, Physics World

GIF Source: Sci-Tech Daily

Topics: Alternate Energy, Battery, Green Tech, Nanotechnology, Quantum Mechanics

Note: I'm in the semifinals of the 3-Minute Thesis competition, so I decided to focus on my presentation. Wish me luck. This does, however, relate to our need as a species to get off fossil fuels as soon as possible, so things like Ukraine, Crimea, and the dismemberment of Jamal Khashoggi are not facilitated by our need for energy and our tolerance for tyrants.

Whether it’s photovoltaics or fusion, sooner or later, human civilization must turn to renewable energies. This is deemed inevitable considering the ever-growing energy demands of humanity and the finite nature of fossil fuels. As such, much research has been pursued in order to develop alternative sources of energy, most of which utilize electricity as the main energy carrier. The extensive R&D in renewables has been accompanied by gradual societal changes as the world adopted new products and devices running on renewables. The most striking change as of recently is the rapid adoption of electric vehicles. While they were hardly seen on the roads even 10 years ago, now millions of electric cars are being sold annually. The electric car market is one of the most rapidly growing sectors, and it helped propel Elon Musk to become the wealthiest man in the world.

Unlike traditional cars which derive energy from the combustion of hydrocarbon fuels, electric vehicles rely on batteries as the storage medium for their energy. For a long time, batteries had far lower energy density than those offered by hydrocarbons, which resulted in very low ranges of early electric vehicles. However, gradual improvement in battery technologies eventually allowed the drive ranges of electric cars to be within acceptable levels in comparison to gasoline-burning cars. It is no understatement that the improvement in battery storage technology was one of the main technical bottlenecks which had to be solved in order to kickstart the current electric vehicle revolution.

New Quantum Technology To Make Charging Electric Cars As Fast as Pumping Gas, Institute for Basic Science, Sci-Tech Daily

Reference: “Quantum Charging Advantage Cannot Be Extensive Without Global Operations” 21 March 2022, Physical Review Letters.

Topics: Battery, Energy, Green Tech, Research, Solid-State Physics

Janus, in Roman religion, the animistic spirit of doorways (januae) and archways (Jani). Janus and the nymph Camasene were the parents of Tiberinus, whose death in or by the river Albula caused it to be renamed Tiber. Source: Encylopedia Britannica

Over the past decade, lithium-ion batteries have seen stunning improvements in their size, weight, cost, and overall performance. (See Physics Today, December 2019, page 20.) But they haven’t yet reached their full potential. One of the biggest remaining hurdles has to do with the electrolyte, the material that conducts Li⁺ ions from anode to cathode inside the battery to drive the equal and opposite flow of charge in the external circuit.

Most commercial lithium-ion batteries use organic liquid electrolytes. The liquids are excellent conductors of Li⁺ ions, but they’re volatile and flammable, and they offer no defense against the whisker-like Li-metal dendrites that can build up between the electrodes and eventually short-circuit the battery. Because safety comes first, battery designers must sacrifice some performance in favor of not having their batteries catch fire.

A solid-state electrolyte could solve those problems. But what kind of solid conducts ions? An ordered crystal won’t do—when every site is filled in a crystalline lattice, Li⁺ ions have nowhere to move to. A solid electrolyte, therefore, needs to have a disordered, defect-riddled structure. It must also provide a polar environment to welcome the Li⁺ ions, but with no negative charges so strong that the Li⁺ ions stick to them and don’t let go.

For several years, Jenny Pringle, Maria Forsyth, and colleagues at Deakin University in Australia have been exploring a class of materials, called organic ionic plastic crystals (OIPCs), that could fit the bill. As a mix of positive and negative ions, an OIPC offers the necessary polar environment for conducting Li⁺. And because the constituent ions are organic, the researchers have lots of chemical leeways to design their shapes so they can’t easily fit together into a regular lattice but are forced to adopt a disordered, Li⁺-permeable structure.

Two-faced ions form a promising battery material, Johanna L. Miller, Physics Today

An aerial view of peat fields in Elva, Estonia. September 30, 2021. REUTERS/Janis Laizans

Topics: Battery, Biofuels, Chemistry, Energy, Green Tech

TARTU, Estonia, Oct 11 (Reuters) - Peat, plentiful in bogs in northern Europe, could be used to make sodium-ion batteries cheaply for use in electric vehicles, scientists at an Estonian university say.

Sodium-ion batteries, which do not contain relatively costly lithium, cobalt, or nickel, are one of the new technologies that battery makers are looking at as they seek alternatives to the dominant lithium-ion model.

Scientists at Estonia's Tartu University say they have found a way to use peat in sodium-ion batteries, which reduces the overall cost, although the technology is still in its infancy.

"Peat is a very cheap raw material - it doesn't cost anything, really," says Enn Lust, head of the Institute of Chemistry at the university.

Energy from bogs: Estonian scientists use peat to make batteries, Janis Laizans and Andrius Sytas, Reuters Science

Australian metals mining wastes (top) and the metal hyperaccumulator plants Alyssum murale and Berkheya coddii (bottom). The former plant can take up 1–3% of its weight in nickel. It has demonstrated yields of up to 400 kg of nickel per hectare annually, worth around $7000 at current prices, excluding processing and production costs. (Images adapted from A. van der Ent, A. Parbhakar-Fox, P. D. Erskine, Sci. Total Environ. 758, 143673, 2021, doi:10.1016/j.scitotenv.2020.143673.)

Topics: Climate Change, Green Tech, Materials Science, Research

When it comes to making steel greener, “only the laws of physics limit our imagination,” says Christina Chang of the Advanced Research Projects Agency-Energy (ARPA–E). Chang, an ARPA–E fellow, is seeking public input on a potential new agency program titled Steel Made via Emissions-Less Technologies. During her two-year tenure, she will guide program creation, agency strategy, and outreach. Steelmaking currently accounts for about 7% of the world’s carbon dioxide emissions, and demand for steel is expected to double by 2050 as low-income countries’ economies grow, according to the International Energy Agency.

Founded in 2009, ARPA–E is a tiny, imaginative office within the Department of Energy. SMELT is one part of a three-pronged thrust by ARPA–E to green up processes involved in producing steel and nonferrous metals, from the mine through to the finished products. Another program seeks ways to make use of the vast volumes of wastes that accumulate from mining operations around the globe—and reduce the amounts generated in the future. The agency is also exploring the feasibility of deploying plants that suck up from soils elements such as cobalt, nickel, and rare earths. Despite being essential ingredients in electric vehicles, batteries, and wind turbines, the US has little or no domestic production of them. (See Physics Today, February 2021, page 20.)

Steelmaking

The first step in steelmaking is separating iron ore into oxygen and iron metal, which produces CO₂ through both the reduction process and the fossil-fuel burning necessary to create high heat. An ARPA–E solicitation for ideas to clean up that process closed on 14 June. The agency is looking to replace the centuries-old blast furnace with greener technology that can work at the scale of 2 gigatons of steel production annually. It may or may not follow up with a request for research proposals to fund.

ARPA–E explores paths to emissions-free metal making, Physics Today

Optimal size: wind farm efficiency drops as installations become bigger. (Courtesy: iStock/ssuaphoto)

Topics: Alternate Energy, Climate Change, Existentialism, Global Warming, Green Tech, Thermodynamics

Optimizing the placement of turbines within a wind farm can significantly increase energy extraction – but only until the installation reaches a certain size, researchers in the US conclude. This is just one finding of a computational study on wind turbines’ effects on the airflow around them, and consequently the ability of nearby turbines – and even nearby wind farms – to extract energy from that airflow.

Wind power could supply more than a third of global energy by 2050, so the researchers hope their analysis will assist in better designs of wind farms.

It is well known that the efficiencies of turbines in a wind farm can be significantly lower than that of a single turbine on its own. While small wind farms can achieve a power density of over 10 W/m², this can drop to a little as 1 W/m² in very large installations The first law of thermodynamics dictates that turbines must reduce the energy of the wind that has passed through them. However, turbines also inject turbulence into the flow, which can make it more difficult for downstream turbines to extract energy.

“People were already aware of these issues,” says Enrico Antonini of the Carnegie Institution for Science in California, “but no one had ever defined what controls these numbers.”

Optimal size for wind farms is revealed by computational study, Tim Wogan, Physics World

MIT engineers have developed self-cooling fabrics from polyethylene, commonly used in plastic bags. They estimate that the new fabric may be more sustainable than cotton and other common textiles. (Courtesy: Svetlana Boriskina)

Topics: Ecology, Environment, Green Tech, Materials Science

Polyethylene is one of the most common plastics in the world, but it is seldom found in clothing because it cannot absorb or carry away water. (Imagine wearing a plastic bag – you would feel very uncomfortable very quickly.) Now, however, researchers in the US have developed a new material spun from polyethylene that not only “breathes” better than cotton, nylon, or polyester, but also has a smaller ecological footprint due to the ease with which it can be manufactured, dyed, cleaned and used.

The textile industry produces about 62 million tons of fabric each year. In the process, it consumes huge quantities of water, generates millions of tons of waste, and accounts for 5–10% of global greenhouse gas emissions, making it one of the world’s most polluting industries. Later stages of the textile use cycle also contribute to the industry’s environmental impact. Textiles made from natural fibers such as wool, cotton, silk, or linen require considerable amounts of energy and water to recycle, while textiles that are colored or made of composite materials are hard to recycle at all.

Hydrophilic and wicking

Researchers led by Svetlana Boriskina of the Massachusetts Institute of Technology (MIT) set out to produce an alternative. They began by melting powdered low-density polyethylene and then extruding it into thin fibers roughly 18.5 μm in diameter (as measured using scanning electron microscopy and micro-computed tomography imaging techniques). This process slightly oxidizes the material’s surface so that it becomes hydrophilic – that is, it attracts water molecules – without the need for a separate chemical treatment.

Recycled plastic bags make sustainable fabrics, Isabelle Dumé, Physics World

(Image by Shutterstock/muratart.)

Topics: Climate Change, Energy, Environment, Existentialism, Global Warming, Green Tech

Thankfully, we're not. Hat tip to Marvel, and Rotten Tomatoes.

Scientists aren’t superheroes. Or are they? Superheroes defend the defenseless and save humanity from any number of disasters, both natural and unnatural, often using powers of logic and some really hip techno-gadgets.

The Earth is in crisis and while it has its own mechanisms to fight back, it could use a helping hand. Earth could use a superhero.

Scientists at the U.S. Department of Energy’s (DOE) Argonne National Laboratory are stepping up and applying decades of expertise and research to combat some of Earth’s toughest foes, from waste and pollution to climate change. And they’ve assembled a cache of some of the world’s coolest technology for this crusade.

So, this Earth Day, we take a look at just a few of the ways Argonne’s scientist-superheroes are swooping in to keep Earth healthy and its citizens safe.

Predicting Earth’s future

What better way to save the planet than knowing what the future holds? Argonne and DOE are leaders in modeling Earth’s complex natural systems to help us keep tabs on the planet’s health. The best of these models can simulate how changes in these systems and our own actions might influence climate and ecosystems many years into the future. They give us a better understanding of the roles played by tropical rain forests, ice sheets, permafrost, and oceans in maintaining carbon levels and help us devise strategies for protecting them — ultimately, identifying how much carbon dioxide (CO₂) we need to reduce from human activities and remove from the atmosphere to stabilize the planet’s temperature.

8 Things Argonne is Doing to Save the Earth, Argonne National Laboratory