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Ultra-thin Layers of Rust Generate Electricity from Flowing Water

Ultra-thin Layers of Rust Generate Electricity from Flowing Water

There are many ways to generate electricity—batteries, solar panels, wind turbines, and hydroelectric dams, to name a few examples. …. And now there’s rust.

New research conducted by scientists at Caltech and Northwestern University shows that thin films of rust—iron oxide—can generate electricity when saltwater flows over them. These films represent an entirely new way of generating electricity and could be used to develop new forms of sustainable power production.

Interactions between metal compounds and saltwater often generate electricity, but this is usually the result of a chemical reaction in which one or more compounds are converted to new compounds. Reactions like these are what is at work inside batteries.

In contrast, the phenomenon discovered by Tom Miller, Caltech professor of chemistry, and Franz Geiger, Dow Professor of Chemistry at Northwestern, does not involve chemical reactions, but rather converts the kinetic energy of flowing saltwater into electricity.

The phenomenon, the electrokinetic effect, has been observed before in thin films of graphene—sheets of carbon atoms arranged in a hexagonal lattice—and it is remarkably efficient. The effect is around 30 percent efficient at converting kinetic energy into electricity. For reference, the best solar panels are only about 20 percent efficient.

“A similar effect has been seen in some other materials. You can take a drop of saltwater and drag it across graphene and see some electricity generated,” Miller says.

However, it is difficult to fabricate graphene films and scale them up to usable sizes. The iron oxide films discovered by Miller and Geiger are relatively easy to produce and scalable to larger sizes, Miller says.

“It’s basically just rust on iron, so it’s pretty easy to make in large areas,” Miller says. “This is a more robust implementation of the thing seen in graphene.”

Though rust will form on iron alloys on its own, the team needed to ensure it formed in a consistently thin layer. To do that, they used a process called physical vapor deposition (PVD), which turns normally solid materials, in this case iron oxide, into a vapor that condenses on a desired surface. PVD allowed them to create an iron oxide layer 10 nanometers thick, about 10 thousand times thinner than a human hair.

When they took that rust-coated iron and flowed saltwater solutions of varying concentrations over it, they found that it generated several tens of millivolts and several microamps per cm-2.

“For perspective, plates having an area of 10 square meters each would generate a few kilowatts per hour—enough for a standard US home,” Miller says. “Of course, less demanding applications, including low-power devices in remote locations, are more promising in the near term.”

The mechanism behind the electricity generation is complex, involving ion adsorption and desorption, but it essentially works like this: The ions present in saltwater attract electrons in the iron beneath the layer of rust. As the saltwater flows, so do those ions, and through that attractive force, they drag the electrons in the iron along with them, generating an electrical current.

Miller says this effect could be useful in specific scenarios where there are moving saline solutions, like in the ocean or the human body.

“For example, tidal energy, or things bobbing in the ocean, like buoys, could be used for passive electrical energy conversion,” he says. “You have saltwater flowing in your veins in periodic pulses. That could be used to generate electricity for powering implants.”

The paper describing their findings, titled “Energy Conversion via Metal Nanolayers,” appears in the July 29 issue of the Proceedings of the National Academy of Sciences. Other co-authors include Mavis D. Boamah, Emilie H. Lozier, Paul E. Ohno, and Catherine E. Walker of Northwestern, and Jeongmin Kim, a graduate student in chemistry at Caltech.

Materials provided by the California Institute of Technology

These Tiny, Weird Worms Make One of The Loudest Sounds Ever Recorded in The Ocean

Researchers detect tiny worm making one of the loudest sounds ever recorded in ocean

We generally imagine that very loud sounds are usually generated by screams or booms which make the entire body vibrate. It is not always that we guess an abrupt pop from a marine worm can produce a sound of such intensity. It has been observed that a tiny 29-millimeter marine worm makes one of the loudest sounds ever recorded in the ocean. The worm species is named Leocratides kimuraorum.

Marine biologist Ryutaro Goto from Kyoto University and his colleagues measured the sounds made by these polychaete worms to be around 157 decibels. The human ear can hear sounds as low as 10 decibels but the sound above 130 decibels can be painful and damaging for our ears. The study has been published in the journal Current Biology.

Several aquatic creatures including fishes, mammals, and insects produce very loud sounds underwater. It is highly unlikely for a soft-bodied worm to produce a loud snap because brief, intense sounds of such nature usually need quite extreme movements and very sophisticated energy storage mechanisms in their body.

Goto and his fellow colleagues were surprised by the racket this creature can create and also initially thought that these creatures were silent. The researchers thought that these soft-bodied animals were not known to produce large sounds until the team took these polychaetes into the lab and witnessed the popping noises which they were able to generate with their mouth. Scientists predict that the loud pop may be a byproduct of the rapid mouth attack but it can also be an aid for the interspecific communication between the species.

These worms produce this loud noise by opening their thick pharyngeal muscles which in turn further create a cavity bubble before exploding it open forcefully. These worms stake out holes in the sea sponges along the Pacific coast of Japan where they wait for the prey to attack and fiercely defend their area from the rivals. Thus this biomechanical puzzle hints at a different sort of extreme biology and making it very clear that marine invertebrates having soft bodies can also generate very loud sounds underwater.

Journal: https://www.sciencedirect.com/science/article/abs/pii/S0960982219306177

Experiments show dramatic increase in solar cell output

Experiments show dramatic increase in solar cell output

In any conventional silicon-based solar cell, there is an absolute limit on overall efficiency, based partly on the fact that each photon of light can only knock loose a single electron, even if that photon carried twice the energy needed to do so. But now, researchers have demonstrated a method for getting high-energy photons striking silicon to kick out two electrons instead of one, opening the door for a new kind of solar cell with greater efficiency than was thought possible.

While conventional silicon cells have an absolute theoretical maximum efficiency of about 29.1 percent conversion of solar energy, the new approach, developed over the last several years by researchers at MIT and elsewhere, could bust through that limit, potentially adding several percentage points to that maximum output. The results are described today in the journal Nature, in a paper by graduate student Markus Einzinger, professor of chemistry Moungi Bawendi, professor of electrical engineering and computer science Marc Baldo, and eight others at MIT and at Princeton University.

The basic concept behind this new technology has been known for decades, and the first demonstration that the principle could work was carried out by some members of this team six years ago. But actually translating the method into a full, operational silicon solar cell took years of hard work, Baldo says.

That initial demonstration “was a good test platform” to show that the idea could work, explains Daniel Congreve PhD ’15, an alumnus now at the Rowland Institute at Harvard, who was the lead author in that prior report and is a co-author of the new paper. Now, with the new results, “we’ve done what we set out to do” in that project, he says.

The original study demonstrated the production of two electrons from one photon, but it did so in an organic photovoltaic cell, which is less efficient than a silicon solar cell. It turned out that transferring the two electrons from a top collecting layer made of tetracene into the silicon cell “was not straightforward,” Baldo says. Troy Van Voorhis, a professor of chemistry at MIT who was part of that original team, points out that the concept was first proposed back in the 1970s, and says wryly that turning that idea into a practical device “only took 40 years.”

The key to splitting the energy of one photon into two electrons lies in a class of materials that possess “excited states” called excitons, Baldo says: In these excitonic materials, “these packets of energy propagate around like the electrons in a circuit,” but with quite different properties than electrons. “You can use them to change energy — you can cut them in half, you can combine them.” In this case, they were going through a process called singlet exciton fission, which is how the light’s energy gets split into two separate, independently moving packets of energy. The material first absorbs a photon, forming an exciton that rapidly undergoes fission into two excited states, each with half the energy of the original state.

But the tricky part was then coupling that energy over into the silicon, a material that is not excitonic. This coupling had never been accomplished before.

As an intermediate step, the team tried coupling the energy from the excitonic layer into a material called quantum dots. “They’re still excitonic, but they’re inorganic,” Baldo says. “That worked; it worked like a charm,” he says. By understanding the mechanism taking place in that material, he says, “we had no reason to think that silicon wouldn’t work.”

What that work showed, Van Voorhis says, is that the key to these energy transfers lies in the very surface of the material, not in its bulk. “So it was clear that the surface chemistry on silicon was going to be important. That was what was going to determine what kinds of surface states there were.” That focus on the surface chemistry may have been what allowed this team to succeed where others had not, he suggests.

The key was in a thin intermediate layer. “It turns out this tiny, tiny strip of material at the interface between these two systems [the silicon solar cell and the tetracene layer with its excitonic properties] ended up defining everything. It’s why other researchers couldn’t get this process to work, and why we finally did.” It was Einzinger “who finally cracked that nut,” he says, by using a layer of a material called hafnium oxynitride.

The layer is only a few atoms thick, or just 8 angstroms (ten-billionths of a meter), but it acted as a “nice bridge” for the excited states, Baldo says. That finally made it possible for the single high-energy photons to trigger the release of two electrons inside the silicon cell. That produces a doubling of the amount of energy produced by a given amount of sunlight in the blue and green part of the spectrum. Overall, that could produce an increase in the power produced by the solar cell — from a theoretical maximum of 29.1 percent, up to a maximum of about 35 percent.

Actual silicon cells are not yet at their maximum, and neither is the new material, so more development needs to be done, but the crucial step of coupling the two materials efficiently has now been proven. “We still need to optimize the silicon cells for this process,” Baldo says. For one thing, with the new system those cells can be thinner than current versions. Work also needs to be done on stabilizing the materials for durability. Overall, commercial applications are probably still a few years off, the team says.

Other approaches to improving the efficiency of solar cells tend to involve adding another kind of cell, such as a perovskite layer, over the silicon. Baldo says “they’re building one cell on top of another. Fundamentally, we’re making one cell — we’re kind of turbocharging the silicon cell. We’re adding more current into the silicon, as opposed to making two cells.”

The researchers have measured one special property of hafnium oxynitride that helps it transfer the excitonic energy. “We know that hafnium oxynitride generates additional charge at the interface, which reduces losses by a process called electric field passivation. If we can establish better control over this phenomenon, efficiencies may climb even higher.” Einzinger says. So far, no other material they’ve tested can match its properties.

Materials provided by Massachusetts Institute of Technology

Magnificent CME Solar eruption of plasma

Researchers discover mystery of exotic material in Sun’s atmosphere

A group of researchers from Ireland and France have declared an important finding on the behaviour of matter in the highly extreme conditions of the atmosphere of Sun. They used radio telescopes and UV cameras on a spacecraft of NASA for knowing about the exotic “fourth state of matter” about which very less is known. This state of matter called plasma may be significant in the development of safe, green and environment-friendly nuclear generator. The results of the study have been published in the Nature Communications journal.

Although the matter we encounter in our daily lives can be differentiated to either solid, liquid or gas, the Universe is majorly made of plasma. It is an extremely unstable fluid which is also highly electrical in nature. Even the Sun is composed of plasma. However, the irony lies in the fact that although the plasma is the most common state of matter in the Universe, human beings have a vague idea of it. Reason being its scarcity on Earth, which makes it difficult to understand.

Laboratories on Earth try to simulate the conditions of space however the Sun is the natural laboratory in which the behaviour of plasma can be understood, which is not possible for the ones attempted on Earth.

Dr Eoin Carley, a Postdoc researcher at the Trinity College Dublin who led the joint collaboration said that the sun’s atmosphere has very extreme conditions with the temperatures of plasma soaring to excess of one million degrees Celsius and particles travelling very close to the speed of light. These particles shine very brightly at the radio wavelengths, hence the behaviour of the plasma can be monitored with the aid of large radio telescopes.

Scientists worked with the researchers at the Paris Observatory and the observations of the Sun were performed by a radio telescope situated in Nançay, central France. These observations were combined with the UV cameras mounted on the Solar Dynamics Observatory spacecraft. It was then seen that plasma on the Sun can eject pulses resembling those from the light house. Scientists were aware of this for many years but could observe it directly for the first time with the help of these highly advanced equipments.

The problem with nuclear fusion plasmas is that they are highly unstable. When the plasma starts producing energy, the reaction is switched off by natural processes. This indicates that it is difficult to produce energy while keeping the plasma stable. By learning about the instability of plasma on the Sun, scientists can learn how to control plasma.

Baltic Servers data center

Scientists set to replace electricity with light pulses for superfast computing

The 21st century is the century which is at the peak of technological revolution. This age revolves around the need for data and analyzing data for the fields of artificial intelligence and machine learning. Multinational companies around the globe are building data centres across continents which have the ability to store and transfer the huge amount of data which the companies receive every day.

Traditionally, data was transferred using electricity but a new method is created by scientists which enable data to be transferred using light pulses. Data centres require a lot of electricity and are hungry for more power, however, the scientists have now developed a technique that uses magnets to control and record computer data which consumes no electricity.

Data centres account for 2-5% of the global power consumption as they need to be maintained at an optimum temperature. Microsoft has already submerged its data centres below in the sea in efforts to reduce power consumption. Originally in hard drives, the data is encoded in 1s and 0s, by the spin of the magnetic hard drives. The magnetic head uses electricity to decode it back which uses a lot of electricity.

An international team have published in Nature that they have replaced electricity by short pulses of light, the duration of these pulses are close to one trillionth of a second. The new method is super efficient and at the same time reduces power consumption to very little. It involves pulsing a magnet at ultra short light bursts at frequencies in the infrared range. It is called the tetra hertz but even the strongest source of tetra hertz light did not provide strong enough pulses to switch the orientation of light. It was made possible due to the coupling between the spins and the tetra hertz electric field.

Scientists put up antennas on top of the magnets to concentrate and enhance the effect of light, a strong electric field was applied which navigated the magnetization in one trillionth of a second to the new orientation which is optimum. This process does not lead to an increase in temperature and thus saves a lot of energy that is spent on the cooling of data centres.

Lancaster University intends to carry out more research using the new ultrafast laser and accelerators which are able to generate intense pulses of light to allow switching magnets. The main significance of this method is the drastic reduction in the cost of operation due to lower energy consumption. It is expected that future energy storage devices are predicted to heavily use and depend on this remarkable breakthrough in technology.

colliding neutron stars

Neutron star collision identified as a major source for many elements on Earth

Space is a vast and boundary-less area full of mystery and unknown. The stars, planets and heavenly bodies exert gravitational forces on each other and which often leads to a collision between two or more planetary objects. The formation and existence of our solar system are always under question. There are many small collisions happening every minute across the universe but are unheard and unnoticed by us.

However, astrophysicists Szabolcs Marka at the University of Columbia and Imre Bartos from the University of Florida have identified a massive and violent collision of 2 neutron stars which happened 4.6 billion years ago and it may be a source of the most coveted matter which we find on Earth. The report has been published in the Nature journal.

This historic event is believed to be the source behind 0.3% of the Earth’s heaviest metals including gold, platinum etc. It also means that whatever we are today or the precious metals that we buy are somewhere or the other linked to the cosmic event which dates back 4.6 billion years. Meteors which have fallen to Earth have metals with radioactive nature. The level of radioactivity at the present instant can determine the age of the meteor; it can be calculated by knowing the decay of the radioactive element.

Scientists predict that the collision could have happened about 100 million years ago before the Earth was formed and that which led to the formation of a gas ball which later formed the milky way galaxy and our planets. Scientists predict that if any kind of similar event would have happened today the vast amount of radioactivity would completely outshine the entire night sky.

This event might just be a uniquely consequential event in our history and the study of the universe. It throws light upon the formation, processes involved, the origin and the composition of the solar system. This collision could be a part of a big cosmic puzzle which lays ahead of us and we need to employ traditional concepts of biology, geology, physics and chemistry to understand this piece of the puzzle and complete the puzzle.

Humans were always curious about where did they come from and where are they heading to. Our past, as well as our future, is a matter of curiosity and concern as we try to justify our place in the universe. More events and collisions like these need to be studied and mapped in order to gauge its effects on our humanity and our future. Space exploration and its understanding is a task which requires lots of hard work and years of patience and experience.


Dark Matter Cloud

Scientists confirm presence of Dark Matter, removing the existing doubts

The universe as we all know is a big and vast collection of planets, stars and galaxies which is spread across a diameter of 10 billion light years. However, the universe at the same time is a huge area full of mystery and dilemma which is constantly being observed and studied by our scientists in search of a clue to solve the puzzle of this great universe which we all a small part of. A curious mind often wonders what this entire universe is made of. This question has been bothering astrophysicists for a long time until lately a term called Dark Matter was termed.

Dark Matter is thought to account for 90-95% of the mass of the universe. The rest 5% mass is believed to be from the stars, galaxies and planets that are in the universe. It is believed to consist of non-luminous material that is thought about as existing in space. It is unlike normal matter as it cannot interact with electromagnetic force and cannot absorb light nor is able to reflect light that falls on it, thus making it harder to spot. Matter when exits exert a gravitational effect around it. Recently though, the existence of dark matter has been brought into question.

Chiara Di Paolo, a doctoral student of astrophysics at SISSA, has said that three years ago, a few colleagues of the Case Western Reserve University strongly questioned the understanding of the universe and therefore the in-depth work of the many researchers, casting doubt on the existence of matter within the galaxies. The reports have been published in The Astrophysical Journal.

After analysis of the rotation curves of 153 curves, an empirical relationship between the total gravitational acceleration of stars was obtained, observed and the component which would be observed in absence of dark matter and presence of ordinary matter as considered in the classical Newtonian theory.

Later Paolo Salucci, a professor of astrophysics at SISSA has stated that they had studied the relationship between total acceleration and its ordinary component in 106 galaxies, obtaining different results from those that had been previously observed from the case of ordinary matter. Thus the variation in results obtained by considering the presence of ordinary matter and the results obtained practically in space which is dark matter is different. He further stated in his statement that the recent developments not only demonstrates the inexactness of the empirical relationship previously described but removes doubts on the existence of dark matter in the galaxies.

Topics such as these continuously being explored and questioned by curious minds all across the world. These theories are constantly questioned in pursuit to prove it, we keep discovering newer things in the ever-changing and mysterious world of physics and astrophysics.

tokamak vaccum vessel

China makes progress in its quest for generating fusion power

Fusion energy has a great capacity of curing humanity’s energy woes forever but still, it has yet to reach the milestone of creating more energy in actual than it is needed to reach to keep the process continuing.

This project has an outcome of billion dollars and the International Thermonuclear Experimental Reactor project is held in the part of the eastern side which is said to be useful for fusion power. This multi-billion-dollar project’s centerpiece will be built using tokamak which is a giant cylindrical fusion device and it is sponsored and run by the European Union, China, Japan, India, Russia, South Kore, and the United States. The parts of the machine will be assimilated which was already progressed at the Experimental Advanced Superconducting Tokamak (EAST) and many different sites and they will draw a conclusion on their findings of the research and about the project which is now under construction in Provence in southern France.

Fusion is thought to be a treasure filled with energy and this is the energy which gives the strength to our sun. It is seen that the fusion mixes the atomic nuclei to create a huge amount of energy and the exact opposite of the process known as fission process is used in nuclear power plants and many atomic weapons which instead of mixing the nuclei separates them into fragments. Fusion does not release any type of gases like greenhouse gases and has a low chance of risk of accidents or the thievery of the atomic material whereas in the case of fission it’s totally opposite.

The total cost of creating the project of ITER is approximately calculated as at 20 billion euros that is A$32.5 billion but in this project the strength of tolerating the high temperature and other conditions which are unstable is very important  and both the necessities are very tough to achieve and they are very expensive as we can see the cost.

Wu Songtao who is a renowned Chinese engineer with ITER gave a conclusion that China’s technical capabilities on the fusion are still lagging behind the other developed countries and other countries like the USA and Japan’s tokamaks have attained more valuable global results. The Anhui test reactor emphasizes that China is improving very quickly towards its scientific advancement and it has a lot more to achieve.

Wu said that the ability of China has improved a lot in this last 20 years and it has improved more after staring the ITER express train project. So it can be concluded that fusion needs to be worked on and achieved together and any one country can’t work on it alone.

Smoke over the river Volga

UN releases Sixth Global Environment Outlook with both good and bad news for us

The Sixth Global Environment Outlook, which is the most comprehensive assessment of the environmental system which is produced by the United Nations in five years has both good and bad news in the store for us.

There has been continuous deterioration of the environment since the first report of GEO-6 was published in 1997 with almost irreversible impacts on the environment if the issues are not addressed. But all hopes are not lost as there are routes to create positive changes and thus a sustainable future can be ensured.

It was launched in the month of March, in the fourth session of the United Nations Environment Assembly which took place in Nairobi. The report is the result of the collaborative work of about 200 experts for 18 months. It covers a wide range of topics such as biodiversity, quality of air, oceans, freshwater, energy and human health.

The state of our environment was assessed and possible courses of action for achieving the goals for the 2030 Agenda of Sustainable Development were also discussed.

There is a fair amount of good news in the GEO-6 amidst all the negative things which reflect the state of the environment in the whole world. There are some pathways to cause a wide scale positive impact which have to be carried out with utmost sincerity and a great rate for creating sustainable futures. The policies which are most likely to make a big impact are related to entire systems such as food, waste management and energy.

For example, if we reduce the consumption of fossil fuels, it leads to better health benefits by reducing the outdoor air pollution which is responsible for causing premature deaths. Also, efforts directed towards reducing worldwide hunger rates can help us to fight many issues such as climate change, land degradation and chemical loss. But all of this has to be done in a short amount of time because, with the increasing rate of change of environmental conditions, the scope for positive action is continuously reducing.

But the GEO-6 also informs us of the condition of the environment which has been deteriorated mainly due to factors such as population growth, climate change and urbanisation. Not to mention, the unprecedented rates of change in technology have also hurt the environment. Currently, we are dealing with issues such as

  • Air pollution causing premature deaths of around 6-7 million annually
  • The sixth largest mass extinction in the history of the planet
  • Disposal of around 8 million tonnes of plastic in the oceans
  • 1.4 million annual deaths due to polluted drinking water and lack of sanitation

Under these circumstances, the various goals under Sustainable Development Goals and Paris Agreement are unlikely to be completed. The GEO-6 has called for sustained and urgent efforts by the governments and business leaders for achieving it.