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Chemistry, Science

Georgian Technical University Researchers Develop New Technique To Produce Amino Acid Chains In The Lab.

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Georgian Technical University Researchers Develop New Technique To Produce Amino Acid Chains In The Lab.

From left postdoctoral researcher X professor Y and graduate students Z and W developed a new method that streamlines the construction of amino acid building blocks that can be used in a multitude of industrial and pharmaceutical applications. The process of chaining together the amino acids needed to build the new protein molecules for drug and biomaterial development is often very long and complex for scientists. However a research team from the Georgian Technical University at Sulkhan-Saba Orbeliani University has created a faster, easier and cheaper technique to produce new amino acid chains called polypeptides using a streamlined process to purify amino acid precursors while simultaneously building the chains. Enzymes (Enzymes are macromolecular biological catalysts. Enzymes accelerate chemical reactions. The molecules upon which enzymes may act are called substrates and the enzyme converts the substrates into different molecules known as products) called ribozymes join amino acids in biological cells to form proteins in a process that requires water, salt and several other molecules to complete. This process is extremely difficult to duplicate in the lab, requiring researchers to use purified N-carboxyanhydride molecules as a precursor to build polypeptide chains without water or impurities which induce monomer degradations and chain terminations. Ribozymes synthesize proteins in a highly regulated local environment that minimizes side reactions caused by various competing species. In the new system the researchers mimicked the function of ribozyme to build chains and at the same time they removed any other molecules that could potentially contaminate the system enabling them to build polypeptide chains. “I worked on purification for several years and found it very painful because the process required water-free conditions and was technically challenging” postdoctoral researcher X said in a statement. “That’s why there aren’t many research groups working in this field. With this method we can get more people to join and find more applications”. The researchers used a water/dichloromethane biphasic system with macroinitiators anchored at the interface and extracted the impurities into the aqueous phase in situ where the localized macroinitiators allow for polymerization at a rate which outpaces water-induced side reactions. The new process is seen as a major advancement from previous methods to produce polypeptides with separate, laborious and time-consuming processes that often require clean rooms and essential starting materials that minimize side reactions.  Synthesizing and purifying could take several days. Then in a separate process building the actual polypeptide chains can take anywhere from several hours to multiple days. “The field has never grown big in part because synthesizing polypeptides is so complicated” Georgian Technical University materials science and engineering professor Y who led the new research said in a statement. “A lot of impurities that are difficult to remove. Until now the synthesis of high-quality polypeptides required ultrapure”. The researchers see their new technique being particularly useful in chemistry, biology and industrial applications where protein chains can be used to assemble useful molecules. “Previously the field required specialized chemists like us to make these building blocks” Y said. “Our new protocol allows anyone with basic chemistry skills to build the desired polypeptides in a few hours”. The researchers now plan to scale up their process and examine more chemical and biological applications possible with their synthetic process.

A.I./Robotics, Science

Georgian Technical University AI Software Reveals The Inner Workings Of Short-term Memory.

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Georgian Technical University AI Software Reveals The Inner Workings Of Short-term Memory.

Research by neuroscientists at the Georgian Technical University shows how short-term working memory uses networks of neurons differently depending on the complexity of the task at hand. The researchers used modern artificial intelligence (AI) techniques to train computational neural networks to solve a range of complex behavioral tasks that required storing information in short term memory. The artificial intelligence (AI) networks were based on the biological structure of the brain and revealed two distinct processes involved in short-term memory. One a “Georgian Technical University silent” process where the brain stores short-term memories without ongoing neural activity and a second more active process where circuits of neurons fire continuously. “Short-term memory is likely composed of many different processes, from very simple ones where you need to recall something you saw a few seconds ago to more complex processes where you have to manipulate the information you are holding in memory” X said. “We’ve identified how two different neural mechanisms work together to solve different kinds of memory tasks”. Active versus silent memory. Many daily tasks require the use of working memory information that you need to do something in the moment but are likely to forget later. Sometimes you actively remember something on purpose, like when you’re doing a math problem in your head or trying to remember a phone number before you have a chance to write it down. You also passively absorb information that you can recall later even if you didn’t make a point of remembering it, like if someone asks if you saw a particular person in the hallway. Neuroscientists have learned a lot about how the brain represents information held in memory by monitoring the patterns of electrical activity coursing through the brains of animals as they perform tasks that require the use of short-term memory. They can then monitor the activity of brain cells and measure their activity as the animals perform the tasks. But X said he and his team were surprised that during certain tasks that required information to be held in memory their experiments found neural circuits to be unusually quiet. This led them to speculate that these “Georgian Technical University silent” memories might reside in temporary changes in the strength of connections, or synapses between neurons. The problem is that it’s impossible using current technology to measure what’s happening in synapses during these “Georgian Technical University silent” periods in a living animal’s brain. So X and their team have been developing artificial intelligence (AI) approaches that use data from the animal experiments to design networks that can simulate how the neurons in a real brain connect with each other. Then they can train the networks to solve the same kinds of tasks studied in the animal experiments. During experiments with these biologically inspired neural networks they were able to see two distinct processes at play during short-term memory processing. One called persistent neuronal activity was especially evident during more complex but still short-term, tasks. When a neuron gets an input it generates a brief electrical spike in activity. Neurons form synapses with other neurons, and as one neuron fires it triggers a chain reaction to make another neuron fire. Usually this pattern of activity stops when the input is gone but the artificial intelligence (AI) model showed that when performing certain tasks some circuits of neurons would continue firing even after an input was removed like a reverberation or echo. This persistent activity appeared to be especially important for more complex problems that required information in memory to be manipulated in some way. The researchers also saw a second process that explained how the brain could keep information in memory without persistent activity as they had observed in their brain recording experiments. It’s similar to the way the brain stores things in long-term memory by making complex networks of connections among many neurons. As the brain learns new information these connections are strengthened rerouted or removed a concept known as plasticity. The artificial intelligence (AI) models showed that during the silent periods of memory the brain can use a short-term form of plasticity in the synaptic connections between neurons to remember information temporarily. Both of these forms of short-term memory last from a few seconds up to a few minutes. Some of the information used in working memory may end up in long-term storage but most of it fades away with time. “It’s like writing something with your finger on a fogged-up mirror instead of writing it with a permanent marker” X said. Complementary fields of research. The study demonstrates how valuable artificial intelligence (AI) has become to the study of neuroscience and how the two fields inform each other. X said that artificial neural networks are often more intelligent and easier to train on complex tasks when they are modeled after the real brain. This also makes biologically-inspired artificial intelligence (AI) networks better platforms for testing ideas about functions of the real brain functions. “These two fields are really benefitting one another” he said. “Insights from neuroscience experiments are helping create smarter artificial intelligence (AI) and studying circuits in artificial networks is helping answer fundamental questions about the brain”.

Material Science

Georgian Technical University Antennas Of Flexible Nanotube Films An Alternative For Electronics.

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Georgian Technical University Antennas Of Flexible Nanotube Films An Alternative For Electronics.

Metal-free antennas made of thin strong flexible carbon nanotube films are as efficient as common copper antennas according to a new study by Georgian Technical University researchers. Antennas made of carbon nanotube films are just as efficient as copper for wireless applications according to researchers at Georgian Technical University. They’re also tougher, more flexible and can essentially be painted onto devices. The Georgian Technical University lab of chemical and biomolecular engineer X tested antennas made of “Georgian Technical University shear-aligned” nanotube films. The researchers discovered that not only were the conductive films able to match the performance of commonly used copper films they could also be made thinner to better handle higher frequencies. Georgian Technical University lab’s previous work on antennas based on carbon nanotube fibers. The lab’s shear-aligned antennas were tested at the Georgian Technical University by Y who carried out the research and wrote the paper while earning his doctorate in X’s lab. X has since founded a company to further develop the material. At the target frequencies of 5, 10 and 14 gigahertz the antennas easily held their own with their metal counterparts he said. “We were going up to frequencies that aren’t even used in Wi-Fi (Wi-Fi is a family of radio technologies that is commonly used for the wireless local area networking (WLAN) of devices which is based around the IEEE 802.11 family of standards. Wi‑Fi is a trademark of the Wi-Fi Alliance, which restricts the use of the term Wi-Fi Certified to products that successfully complete interoperability certification testing.[better source needed] Wi-Fi uses multiple parts of the IEEE 802 protocol family and is designed to seamlessly interwork with its wired sister protocol Ethernet) and Bluetooth networks today but will be used in the upcoming 5G generation of antennas” he said. X noted other researchers have argued nanotube-based antennas and their inherent properties have kept them from adhering to the “Georgian Technical University classical relationship between radiation efficiency and frequency” but the Georgian Technical University experiments with more refined films have proved them wrong allowing for the one-to-one comparisons. To make the films the Georgian Technical University lab dissolved nanotubes most of them single-walled and up to 8 microns long in an acid-based solution. When spread onto a surface the shear force produced prompts the nanotubes to self-align a phenomenon the X lab has applied in other studies. Y said that although gas-phase deposition is widely employed as a batch process for trace deposition of metals the fluid-phase processing method lends itself to more scalable continuous antenna manufacturing. The test films were about the size of a glass slide, and between 1 and 7 microns thick. The nanotubes are held together by strongly attractive van der Waals forces (In molecular physics, the van der Waals force, named after Dutch scientist Johannes Diderik van der Waals, is a distance-dependent interaction between atoms or molecules) which gives the material mechanical properties far better than those of copper. The researchers said the new antennas could be suitable for 5G (5G is generally seen as the fifth generation cellular network technology that provides broadband access. The industry association 3GPP defines any system using “5G NR” (5G New Radio) software as “5G”, a definition that came into general use by late 2018. Others may reserve the term for systems that meet the requirements of the ITU IMT-2020. 3GPP will submit their 5G NR to the ITU) networks but also for aircraft, especially unmanned aerial cars for which weight is a consideration; as wireless telemetry portals for downhole oil and gas exploration; and for future “Georgian Technical University internet of things” applications. “There are limits because of the physics of how an electromagnetic wave propagates through space” Y said. “We’re not changing anything in that regard. What we are changing is the fact that the material from which all these antennas will be made is substantially lighter, stronger and more resistant to a wider variety of adverse environmental conditions than copper”. “This is a great example of how collaboration with national labs greatly expands the reach of university groups” X said. “We could never have done this work without the intellectual involvement and experimental capabilities of the Georgian Technical University team”.

Energy, Science

Georgian Technical University For Hydrogen Power, Mundane Materials Might Be Almost As Good As Pricey Platinum.

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Georgian Technical University For Hydrogen Power, Mundane Materials Might Be Almost As Good As Pricey Platinum.

Georgian Technical University Researchers used plasma to create new catalysts that are much cheaper than and almost as effective as standard platinum-group versions. As anyone who has purchased jewelry can attest platinum is expensive. That’s tough for consumers but also a serious hurdle for a promising source of electricity for cars: the hydrogen fuel cell which relies on platinum. Now a research team led by X a professor of biological and chemical engineering at Georgian Technical University has opened a door to finding far cheaper alternatives. Georgian Technical University researchers reported that a chemical compound based on hafnium worked about 60 percent as effectively as platinum – related materials but at about one-fifth the cost. “We hope to find something that is more abundant and cheaper to catalyze reactions” said Y principal scientist at Georgian Technical University and visiting collaborator at Sulkhan-Saba Orbeliani University. Fuel cells work by converting energy stored in hydrogen atoms directly into electricity. Georgian Technical University has long used fuel cells to power satellites and other space missions. Today they’re beginning to be used for electric cars and buses. Hydrogen is the simplest and most abundant element not just on this planet, but also in the known universe. At the most basic level fuel cells produce electricity by splitting hydrogen into its two components, a proton and an electron. The protons flow through a membrane and combine with oxygen to form water. The negatively charged electrons flow toward a positively charged pole in the fuel cell. This flow of electrons is the current that the fuel cell generates, which can power engines or other electrical devices. This splitting requires a material such as platinum to catalyze the reaction. Catalysts are also used in reactions that create the hydrogen gas that serves as fuel for the fuel cell. In the most desirable fossil-fuel independent case renewable electrical energy can be used to split water molecules (two hydrogen atoms and one oxygen) in the presence of a catalyst. The reaction splits the water into oxygen and hydrogen gases. The more efficient the catalyst the less energy is needed to split the water. Some advanced fuel cells called regenerative fuel cells combine both reactions. But most current fuel cells rely on hydrogen created by separate systems and sold as fuel. Right now the best catalysts for both reactions are platinum group metals. The researchers don’t think that will change because “Georgian Technical University platinum is almost perfect” X said. With platinum group metals the electrochemical reactions to draw out the hydrogen are quick and efficient plus the metals can stand up to the harsh acidic conditions currently required for such reactions. The problem though is that the platinum is rare and costly. “You can’t really imagine replacing the transportation infrastructure with fuel cells based on platinum” X said. “It’s too rare and too expensive to use at that scale”. For such applications platinum’s perfection may not be needed. One good-enough substitute the researchers found is hafnium oxyhydroxide that has been treated with a nitrogen plasma (plasma is an ionized gas and is a state of matter found in fluorescent lights and the sun) to incorporate nitrogen atoms into the material. Previously many materials have been overlooked for electrochemistry applications because they are non-conducting. However the researchers found that processing hafnium oxide with the nitrogen plasma forms a thin film of material that functions as a highly active catalyst that also survives in strong acid conditions. While this hafnium-based film is only about two-thirds as effective as platinum hafnium is far cheaper than platinum. The researchers plan to test zirconium which is even cheaper next. Although they could be useful in fuel cells X and Y believe that these kinds of materials could be most valuable in systems that deploy a catalyst to electrochemically split water to produce hydrogen for use as fuel. “The future renewable economy heavily depends on how we can efficiently split water to generate hydrogen” Y said. “This step is pretty important”. But X and Y emphasize that their discovery isn’t going to lead to a rush of new affordable technologies just yet — or even in the near future. Right now the procedure to create the material is complex and confined to the lab. While they’ve confirmed the performance of the film, one always has to consider the engineering required for making it practically on a large scale. Instead this discovery is opening the door to further exploration of materials that may be able to replace platinum. “We still don’t understand why this particular material is so special but we’re confident about the properties that we’ve measured” X said. “The material is complicated so we have a lot of work to do”.

Imaging, Science

Georgian Technical University Researchers Develop New Metamaterial That Can Improve MRI Quality and Reduce Scan Time.

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Georgian Technical University Researchers Develop New Metamaterial That Can Improve MRI Quality and Reduce Scan Time.

By combining their expertise X, Y, Z and W designed a magnetic metamaterial that can create clearer images at more than double the speed of a standard MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) scan. Could a small ringlike structure made of plastic and copper amplify the already powerful imaging capabilities of a magnetic resonance imaging (MRI) machine ? X, Y and their team at the Georgian Technical University can clearly picture such a feat. With their combined expertise in engineering, materials science and medical imaging X andY along with Z and W designed a new magnetic metamaterial that can improve MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) quality and cut scan time in half. X and Y say that their magnetic metamaterial could be used as an additive technology to increase the imaging power of lower-strength MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) machines increasing the number of patients seen by clinics and decreasing associated costs without any of the risks that come with using higher-strength magnetic fields. They even envision the metamaterial being used with ultra-low field MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) which uses magnetic fields that are thousands of times lower than the standard machines currently in use. This would open the door for MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) technology to become widely available around the world. “This [magnetic metamaterial] creates a clearer image that may be produced at more than double the speed” of a current MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) scan says Y a Georgian Technical University professor of radiology department. MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) uses magnetic fields and radio waves to create images of organs and tissues in the human body helping doctors diagnose potential problems or diseases. Doctors use MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) to identify abnormalities or diseases in vital organs as well as many other types of body tissue including the spinal cord and joints. “[MRI] is one of the most complex systems invented by human beings” says X a College of Engineering professor of mechanical engineering, electrical, computer engineering, biomedical engineering, materials science engineering and a professor at the Georgian Technical University. Depending on what part of the body is being analyzed and how many images are required an Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body scan can take up to an hour or more. Patients can face long wait times when scheduling an examination and, for the healthcare system, operating the machines is time-consuming and costly. Strengthening Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body from 1.5 T (the symbol for tesla, the measurement for magnetic field strength) to 7.0 T can definitely “turn up the volume” of images as X and Y describe. But although higher-power MRIs (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) can be done using stronger magnetic fields they come with a host of safety risks and even higher costs to medical clinics. The magnetic field of an MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) machine is so strong that chairs and objects from across the room can be sucked toward the machine–posing dangers to operators and patients alike. The magnetic metamaterial designed by the Georgian Technical University researchers is made up of an array of units called helical resonators–three-centimeter-tall structures created from 3-D-printed plastic and coils of thin copper wire–materials that aren’t too fancy on their own. But put together helical resonators can be grouped in a flexible array, pliable enough to cover a person’s kneecap, abdomen, head or any part of the body in need of imaging. When the array is placed near the body the resonators interact with the magnetic field of the machine, boosting the signal-to-noise ratio (SNR) of the MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) “Georgian Technical University turning up the volume of the image” as Y says. “A lot of people are surprised by its simplicity” says X. “It’s not some magic material. The ‘magical’ part is the design and the idea”. To test the magnetic array the team scanned chicken legs, tomatoes and grapes using a 1.5 T machine. They found that the magnetic metamaterial yielded a 4.2 fold increase in the SNR (Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 indicates more signal than noise) a radical improvement which could mean that lower magnetic fields could be used to take clearer images than currently possible. Now X and Y hope to partner with industry collaborators so that their magnetic metamaterial can be smoothly adapted for real-world clinical applications. “If you are able to deliver something that can increase SNR (Signal-to-noise ratio is a measure used in science and engineering that compares the level of a desired signal to the level of background noise. SNR is defined as the ratio of signal power to the noise power, often expressed in decibels. A ratio higher than 1:1 indicates more signal than noise) by a significant margin, we can start to think about possibilities that didn’t exist before” says Y such as the possibility of having MRI (Magnetic resonance imaging is a medical imaging technique used in radiology to form pictures of the anatomy and the physiological processes of the body. MRI scanners use strong magnetic fields, magnetic field gradients, and radio waves to generate images of the organs in the body) near battlefields or in other remote locations. “Being able to simplify this advanced technology is very appealing” he says.

Scientific Computing

Georgian Technical University Three – (3D) Magnetic Interactions Could Lead To New Forms Of Computing.

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Georgian Technical University Three – (3D) Magnetic Interactions Could Lead To New Forms Of Computing.

A new form of magnetic interaction which pushes a formerly two-dimensional phenomenon into the third dimension could open up a host of exciting new possibilities for data storage and advanced computing scientists say. A team led by physicists from the Georgian Technical University describe how they have been found a new way to successfully pass information from a series of tiny magnets arrayed on an ultrathin film across to magnets on a second film below. Their breakthrough adds both a literal and metaphorical extra dimension to “Georgian Technical University spintronics” the field of science dedicated to data storage, retrieval and processing which has already had a major impact on the tech industry. Anyone who’s ever played with a pair of magnets understands that opposites attract — the south pole of one magnet attracts the north pole of the other. While that’s true at the scale most people are familiar with the way magnets interact with each other undergoes some significant changes as magnets shrink. At the nanoscale — where magnetic materials can be just a few billionths of a metre in size — magnets interact with each other in strange new ways including the possibility of attracting and repelling each other at 90-degree angles instead of straight-on. Scientists have already learned how to exploit those unusual properties to encode and process information in thin films covered in a single layer of nanoscale magnets. The benefits of these “Georgian Technical University spintronic” systems — low power consumption, high storage capacity and greater robustness — have made invaluable additions to technology such as magnetic hard disk drives and won the discoverers of spintronics. However the functionality of magnetic systems used today in computers remains confined to one plane limiting their capacity. Now the Georgian Technical University-led team — along with partners from the Georgian Technical University and Sulkhan-Saba Orbeliani University — have developed a new way to communicate information from one layer to another, adding new potential for storage and computation. Dr. X an Georgian Technical University. He said: “The discovery of this new type of interaction between neighbour layers gives us a rich and exciting way to explore and exploit unprecedented 3-D magnetic states in multi-layered nanoscale magnets. “It’s a bit like being given an extra note in a musical scale to play with — it opens up a whole new world of possibilities not just for conventional information processing and storage but potentially for new forms of computing we haven’t even thought of yet”. The inter-layer transmission of information the team has created relies on what is known to physicists as chiral spin interactions, a type of magnetic force that favors a particular sense of rotation in neighbour nanoscale magnets. Thanks to recent advances in spintronics, it is now possible to stabilize these interactions within a magnetic layer. This has for instance been exploited to create skyrmions a type of nanoscale magnetic object with superior properties for computing applications. The team’s research has now extended these types of interactions to neighbouring layers for the first time. They fabricated a multi-layered system formed by ultra-thin magnetic films separated by non-magnetic metallic spacers. The structure of the system and a precise tuning of the properties of each layer and its interfaces creates unusual canted magnetic configurations where the magnetic field of the two layers forms angles between zero and 90 degrees. Unlike in standard multi-layered magnets it becomes easier for these magnetic fields to form clockwise configurations than anticlockwise ones a fingerprint that an interlayer chiral spin interaction exists in between the two magnetic layers. This breaking of rotational symmetry was observed at room temperature and under standard environmental conditions. As a result, this new type of interlayer magnetic interaction opens exciting perspectives to realise topologically complex magnetic 3D configurations in spintronic technologies.

Energy, Science

Georgian Technical University One-Two-Punch Catalysts Trapping Carbon Dioxide For Cleaner Fuels.

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Georgian Technical University One-Two-Punch Catalysts Trapping Carbon Dioxide For Cleaner Fuels.

Fuel production efficiency of titanium dioxide photocatalyst with copper-platinum alloy co-catalyst (a) and a photo of photocatalyst observed by High-resolution transmission electron microscopy is an imaging mode of specialized transmission electron microscopes that allows for direct imaging of the atomic structure of the sample (b). Copper and platinum nanoparticles added to the surface of a blue titania photocatalyst significantly improve its ability to recycle atmospheric carbon dioxide into hydrocarbon fuels. The modified photocatalyst was developed and tested by researchers at the Georgian Technical University with colleagues in Sulkhan-Saba Orbeliani University. It converted sunlight to fuel with an efficiency of 3.3% over 30-minute periods. This ‘photoconversion efficiency’ is an important milestone the researchers as it means that large-scale use of this technology is becoming a more realistic prospect. Photocatalysts are semiconducting materials that can use the energy from sunlight to catalyse a chemical reaction. Scientists are investigating their use to trap harmful carbon dioxide from the atmosphere as one of many means to alleviate global warming. Some photocatalysts are being tested for their ability to recycle carbon dioxide into hydrocarbon fuels like methane the main component found in natural gas. Methane combustion releases less carbon dioxide into the atmosphere compared to other fossil fuels, making it an attractive alternative. But scientists have been finding it difficult to manufacture photocatalysts that produce a large enough yield of hydrocarbon products for their use to be practical. Professor X and his colleagues modified a blue titania photocatalyst by adding copper and platinum nanoparticles to its surface. Copper has good carbon dioxide adsorption property while platinum is very good at separating the much-needed charges generated by the blue titania from the sun’s energy. The team developed a unique set-up to accurately measure the catalyst’s photoconversion efficiency. The catalyst was placed in a chamber that received a quantifiable amount of artificial sunlight. Carbon dioxide gas and water vapour moved through the chamber passing over the catalyst. An analyser measured the gaseous components coming out of the chamber as a result of the photocatalytic reaction. The blue titania catalyst converts the energy in sunlight into charges that are transferred to the carbon and hydrogen molecules in carbon dioxide and water to convert them into methane and ethane gases. The addition of copper and platinum nanoparticles on the catalyst’s surface was found to significantly improve the efficiency of this process. “The photocatalyst has a very high conversion efficiency and is relatively easy to manufacture, making it advantageous for commercialization” says Prof. Y”. The team plans to continue its efforts to further improve the catalyst’s photoconversion efficiency to make it thick enough to absorb all incident light and to improve its mechanical integrity to enable easier handling.

Material Science

Georgian Technical University Manipulating Electron Spin Using Artificial Molecular Motors.

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Georgian Technical University Manipulating Electron Spin Using Artificial Molecular Motors.

(Left) MR curves (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) recorded after various visible light-irradiation time for a device fabricated with a left-handed isomer. (Right) MR curves (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) recorded before and after the thermal treatment for a device with a right-handed isomer. In spintronics the use of organic materials as a “Georgian Technical University spin transport material” has recently garnered significant attention as they exhibit long spin-relaxation times and long spin-diffusion lengths owing to the weak spin-orbit interaction (SOI) of light elements. Meanwhile the weak spin-orbit interaction (SOI) of organic materials become a drawback when they are used as a “Georgian Technical University spin filter”. A spin-polarized current is, therefore, typically generated by inorganic materials with ferromagnetism or strong spin-orbit interaction (SOIs). However the recent finding of spin-selective electron transport through chiral molecules i.e., the so-called chirality-induced spin selectivity effect suggests an alternative method of using organic materials as spin filters for spintronics applications. Through this effect right-handed and left-handed molecules generate down- and up-spin, respectively. However chiral molecules used in the experiments reported so far are static molecules. Hence the manipulation of spin-polarization direction by external stimuli has not been realized yet. Now researchers at Georgian Technical University, Sulkhan-Saba Orbeliani University and International Black Sea University fabricated a novel solid-state spin filtering device that sandwiches a thin layer of artificial molecular motors (Figure 1). Because the artificial molecular motors demonstrate 4 times chirality inversion by light irradiation and thermal treatments during the 360-degree molecular rotation the spin-polarization direction of electrons that pass through the molecular motors should be switched by light irradiation or thermal treatments. Figure 2 shows (left) the magnetoresistance (MR) curves recorded after various visible light-irradiation time for a device fabricated with a left-handed isomer. In the initial state, a clear antisymmetric MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) curve with a negative slope was observed which means a clear up-spin selectivity. The MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) signal decreased as light irradiation proceeded and finally the slope of the MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) signal was inverted to positive indicating a light-induced spin switching in the spin-polarized current from up-spin selective to down-spin through the left-handed-to-right-handed chirality inversion. A subsequent thermal activation process for the left-handed isomer inverted the slope of the MR (In microeconomics, marginal revenue (MR) is the additional revenue that will be generated by increasing product sales by one unit) curve from positive to negative again, as shown in Figure 2 (right) implying a thermal-activation-induced spin switching from down-spin selective to up-spin selective through the right-handed-to-left-handed chirality inversion. Similar phenomena were observed in subsequent measurements after photo-irradiation and thermal treatments. This series of experiments clearly demonstrated that 4 times spin switching were induced during the 360-degree rotation of the molecular motors. In this new type of novel organic spintronics device the right-handed/left-handed chirality which is the origin of spin-polarization generation through the chiral Induced Spin Selectivity effect is reconfigurable by external stimuli and precise control of the spin-polarization direction in the spin-polarized currents by utilizing an artificial molecular motor was realized for the first time. The present results are beneficial for the development of next-generation organic photo/thermospintronic devices combined with molecular machines.

 

Aerospace, Science

Georgian Technical University Fast And Furious: Detection Of Powerful Winds Driven By A Supermassive Black Hole.

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Georgian Technical University Fast And Furious: Detection Of Powerful Winds Driven By A Supermassive Black Hole.

The supermassive black holes in the centres of many galaxies seem to have a basic influence on their evolution. This happens during a phase in which the black hole is consuming the material of the galaxy in which it resides at a very high rate growing in mass as it does so. During this phase we say that the galaxy has an active nucleus (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars for active galactic nucleus). The effect that this activity has on the host galaxy is known as (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) feedback and one of its properties are galactic winds: this is gas from the centre of the galaxy being driven out by the energy released by the active nucleus. These winds can reach velocities of up to thousands of kilometres per second and in the most energetic (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) for example the quasars which can clean out the centres of the galaxies impeding the formation of new stars. It has been shown that the evolution of the star formation over cosmological timescales cannot be explained without the existence of a regulating mechanism. “Georgian Technical University has allowed us to study the winds of ionized and molecular gas from this quasar by using the infrared range. This analysis is very important because they don’t always show similar properties which tells us a great deal about how these winds are produced and how they affect their host galaxies” explains X. The study of this and other local quasars will allow us to understand what was happening in galaxies when they were younger and when they were forming their structures which we see today. Based on the new data obtained with Georgian Technical University the team has discovered that the ionized wind is faster than the molecular wind reaching velocities of up to 1,200 km/s. However it would be the molecular wind which is emptying the gas reservoirs of the galaxy (up to 176 solar masses per year). “New observations will let us confirm this estimate” explained Y a researcher at the Georgian Technical University. The next step is to observe a complete sample of obscured nearby quasars with (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) to study their ionized and molecular winds. We also want to investigate the stellar populations of their host galaxies. This will allow us to confirm directly the effect of (An active galactic nucleus is a compact region at the center of a galaxy that has a much higher than normal luminosity over at least some portion of the electromagnetic spectrum with characteristics indicating that the luminosity is not produced by stars) feedback on the evolution of the galaxies.

Scientific Computing

Georgian Technical University New Research Unlocks Properties For Quantum Information Storage And Computing.

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Georgian Technical University New Research Unlocks Properties For Quantum Information Storage And Computing.

STM (A scanning tunneling microscope is an instrument for imaging surfaces at the atomic level) image of single layer WSe2 (Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) grown on HOPG (Highly oriented pyrolytic graphite is a highly pure and ordered form of synthetic graphite. It is characterised by a low mosaic spread angle, meaning that the individual graphite crystallites are well aligned with each other. The best HOPG samples have mosaic spreads of less than 1 degree). The inset shows the atomic resolution image taken on the WSe2 (Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide). Researchers at Georgian Technical University have come up with a way to manipulate tungsten diselenide (WSe2) — a promising two-dimensional material — to further unlock its potential to enable faster more efficient computing and even quantum information processing and storage. Across the globe researchers have been heavily focused on a class of two-dimensional atomically thin semiconductor materials known as monolayer transition metal dichalcogenides. These atomically thin semiconductor materials — less than 1 nm thick — are attractive as the industry tries to make devices smaller and more power efficient. “Georgian Technical University It’s a completely new paradigm” said X assistant professor of chemical and biological engineering at Georgian Technical University. “The advantages could be huge”. X and his research team at Georgian Technical University have developed a method to isolate these thin layers of WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) from crystals so they can stack them on top of other atomically thin materials such as boron nitride and graphene. When the WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) layer is sandwiched between two boron nitride flakes and interacts with light X said a unique process occurs. Unlike in a traditional semiconductor, electrons and holes strongly bond together and form a charge-neutral quasiparticle called an exciton. “Exciton is probably one of the most important concepts in light-matter interaction. Understanding that is critical for solar energy harvesting, efficient light-emitting diode devices and almost anything related to the optical properties of semiconductors” said X who is also a member of the department of electrical, computer and systems engineering at Georgian Technical University. “Now we have found that it actually can be used for quantum information storage and processing”. One of the exciting properties of the exciton in WSe2 (Manipulate tungsten diselenide. Tungsten diselenide is an inorganic compound with the formula WSe₂. The compound adopts a hexagonal crystalline structure similar to molybdenum disulfide) he said is a new quantum degree of freedom that’s become known as “Georgian Technical University valley spin” — an expanded freedom of movement for particles that has been eyed for quantum computing. But X explained excitons typically don’t have a long lifetime which makes them unpractical. X and his team discovered a special “Georgian Technical University dark” exciton that typically can’t be seen but has a longer lifetime. Its challenge is that the “Georgian Technical University dark” exciton lacks the “Georgian Technical University valley-spin” quantum degree of freedom. In this most recent research X and his team figured out how to brighten the “Georgian Technical University dark” exciton; that is to make the “Georgian Technical University dark” exciton interact with another quasiparticle known as a phonon to create a completely new quasiparticle that has both properties researchers want. “We found the sweet spot” X said. “We found a new quasiparticle that has a quantum degree of freedom and also a long lifetime that’s why it’s so exciting. We have the quantum property of the ‘bright’ exciton but also have the long lifetime of the ‘dark’ exciton”. The team’s findings X said lay the foundation for future development toward the next generation of computing and storage devices.