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Krafla geothermal power station

Researchers develop technique to exploit geothermal energy in a sustainable manner

The way we fuel our power production has been significantly changed by the demand to limit emissions and ascent of renewables, from wind to solar to biomass. Those technologies are the world’s most appealing, energizing and emerging technologies which aim at producing energy. However, there is a massive, permanent and unused energy resource which is existing literally under our noses. We are referring to geothermal energy. Generation of geothermal energy is possible through the devices to make use of heat inside the Earth’s crust.

Researchers from Tokyo Tech have made major progress in understanding and advancement of sensitized thermal cells (STCs) which is a type of battery that can produce electric power at 100-degree Celsius or less. The study has been published in the Journal of Materials Chemistry A.

Before this, they have proposed the use of STCs as a new method for converting heat directly into electric power using dye-sensitized solar cells. They likewise replaced the dye with a semiconductor to enable the system to work using heat rather than light.

In the new cell, an electron transport layer (ETM), a semiconductor layer (germanium), and a solid electrolyte layer (copper ions) are sandwiched between the electrodes of the battery where electrons get thermally excited while going from a low-energy state to a high-energy state in the semiconductor and finally shifting naturally to the ETM.

Oxidation and reduction reaction involving copper ions take place at the interconnection of both electrolytes while electrons travel from the electrode through an external circuit, pass through the counter electrode, and then reach the electrolyte. This completes an electric circuit shifting low-energy electrons to the semiconductor layer. Scientists during the experiment found out that after a certain time, the electricity stopped flowing instead of working as a perpetual machine. This is due to the completion of redox reactions at the electrolyte end owing to the shifting of different types of copper ions.

Existence of heat simply opens up the external circuit for a short time reverting the situation. Dr Sachiko Matsushita, study leader said that heat which is considered as low-grade energy, would become a great renewable energy source with such design. Scientists are excited about the model as it is nature-friendly and has the possibility to solve the global energy crisis.

Moreover, he added that there is no fear of costly oil, radiation or instability of power generation when done with the help of sun or wind. The goal of future research will be the enhancement of battery with the belief of solving mankind energy needs without harming the earth.

Journal Reference: Journal of Materials Chemistry A

Electron-behaving nanoparticles rock current understanding of matter

Electron-behaving nanoparticles rock current understanding of matter

It’s not an electron. But it sure does act like one.

Northwestern University researchers have made a strange and startling discovery that nanoparticles engineered with DNA in colloidal crystals — when extremely small — behave just like electrons. Not only has this finding upended the current, accepted notion of matter, it also opens the door for new possibilities in materials design.

“We have never seen anything like this before,” said Northwestern’s Monica Olvera de la Cruz, who made the initial observation through computational work. “In our simulations, the particles look just like orbiting electrons.”

With this discovery, the researchers introduced a new term called “metallicity,” which refers to the mobility of electrons in a metal. In colloidal crystals, tiny nanoparticles roam similarly to electrons and act as a glue that holds the material together.

“This is going to get people to think about matter in a new way,” said Northwestern’s Chad Mirkin, who led the experimental work. “It’s going to lead to all sorts of materials that have potentially spectacular properties that have never been observed before. Properties that could lead to a variety of new technologies in the fields of optics, electronics and even catalysis.”

The paper will be published on Friday, June 21 in the journal Science.

Olvera de la Cruz is the Lawyer Taylor Professor of Materials Science and Engineering in Northwestern’s McCormick School of Engineering. Mirkin is the George B. Rathmann Professor of Chemistry in Northwestern’s Weinberg College of Arts and Sciences.

Mirkin’s group previously invented the chemistry for engineering colloidal crystals with DNA, which has forged new possibilities for materials design. In these structures, DNA strands act as a sort of smart glue to link together nanoparticles in a lattice pattern

“Over the past two decades, we have figured out how to make all sorts of crystalline structures where the DNA effectively takes the particles and places them exactly where they are supposed to go in a lattice,” said Mirkin, founding director of the International Institute for Nanotechnology.

In these previous studies, the particles’ diameters are on the tens of nanometers length scale. Particles in these structures are static, fixed in place by DNA. In the current study, however, Mirkin and Olvera de la Cruz shrunk the particles down to 1.4 nanometers in diameter in computational simulations. This is where the magic happened.

“The bigger particles have hundreds of DNA strands linking them together,” said Olvera de la Cruz. “The small ones only have four to eight linkers. When those links break, the particles roll and migrate through the lattice holding together the crystal of bigger particles.”

When Mirkin’s team performed the experiments to image the small particles, they found that Olvera de la Cruz’s team’s computational observations proved true. Because this behaviour is reminiscent of how electrons behave in metals, the researchers call it “metallicity.”

“A sea of electrons migrates throughout metals, acting as a glue, holding everything together,” Mirkin explained. “That’s what these nanoparticles become. The tiny particles become the mobile glue that holds everything together.”

Olvera de la Cruz and Mirkin next plan to explore how to exploit these electron-like particles in order to design new materials with useful properties. Although their research used gold nanoparticles, Olvera de la Cruz said “metallicity” applies to other classes of particles in colloidal crystals.

“In science, it’s really rare to discover a new property, but that’s what happened here,” Mirkin said. “It challenges the whole way we think about building matter. It’s a foundational piece of work that will have a lasting impact.”

Materials provided by Northwestern University

Shield Cryostat XENON 100

Scientists successfully observe radioactive decay of xenon isotope, the slowest process ever detected

The research team of XENON Collaboration built an instrument which captures the processes that take time longer than the formation of the universe. The researchers have reported that they have noticed the radioactive decay of Xenon-124 which has a half-life of 1.8 * 1022 years. The results have been published in the Nature journal.

In this situation, researchers managed to study a special case known as double electron capture in which two protons present in a xenon atom at the same time absorb two electrons which lead to the formation of two neutrons and they also explained that this is the rarest thing which is multiplied by another which makes it ultra rare. Ethan Brown a co-author of the study and an assistant professor of physics at Rensselaer Polytechnic Institute said that they saw the decay happening and it was the slowest process ever and that their dark matter detector can very quick to measure the rarest thing recorded.

The instrument is invented to identify the interactions of hypothetical dark matter particles which have atoms weighing 1,300kg in Xenon isotope which is packed inside the tank of the device. But in this situation the censors instead of recording the particles it recorded the decaying of the isotope in itself which lead to a rare survey of a different kind. The decaying of the xenon isotope was never noticed by scientists directly even if there was a theory behind this since 1955 and it’s the proof of something they have been examining since decades.

XENON1T detects the signals sent by the electron in atoms by reordering themselves to fit for the two that were arrested in the nucleus. Brown said that a room is created in the shell when the electrons in double capture are removed from the innermost shell around the nucleus and the rest collapses in the ground state and this process was observed by them. XENON1T can also be a cause of finding important things and that the recent study can teach us more about neutrinos which are large but very difficult to detect the particles which scientists are looking for decades now.

Here the researchers noticed two-neutrino double electron capture which is due to the reordering of electrons which means two electrons were discharged by the atomic nucleus. Curt Breneman from RPI said that this is a fantastic discovery which helps in gaining more knowledge on the basic features of the matter. Scientists are currently working on upgrading the equipment for XENONnT in which the active mass detector will be thrice larger than XENON1T. It will have an improved sensitivity as compared to XENON1T.