Category Archives: Science

Imaging, Science

New Technology Yields Cheaper Ultrasound Machine.

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New Technology Yields Cheaper Ultrasound Machine.

Georgian Technical University  researcher X shows new ultrasound transducer.

A team from the Georgian Technical University has created a portable, wearable ultrasound transducer that could reduce the cost of ultrasound scanners down to about 100 Lari.

Conventional ultrasound scanners utilize piezoelectric crystals that are able to create images of the inside of the body and send them to a computer to create sonograms.

However in the new transducer the scientists switched the piezoelectric crystals out with small vibrating drums made from a polymer resin — polymer capacitive micro-machined ultrasound transducers (polyCMUTs) which are less expensive to manufacture.

“Transducer drums have typically been made out of rigid silicon materials that require costly environment-controlled manufacturing processes, and this has hampered their use in ultrasound” X a PhD candidate in electrical and computer engineering at Georgian Technical University said in a statement. “By using polymer resin we were able to produce polymer capacitive micro-machined ultrasound transducers (polyCMUTs) in fewer fabrication steps using a minimum amount of equipment resulting in significant cost savings”.

The device features low operational voltage and are highly sensitive partially due to a pre-biasing condition on the membrane. The fabrication used simple equipment with a reduced number of fabrication steps needed.

The sonograms it produced were at least as sharp and in some cases more detailed than traditional sonograms produced with piezoelectric transducers.

“Since our transducer needs just 10 volts to operate it can be powered by a smartphone making it suitable for use in remote or low-power locations” Y a professor of electrical and computer engineering said in a statement. “And unlike rigid ultrasound probes our transducer has the potential to be built into a flexible material that can be wrapped around the body for easier scanning and more detailed views–without dramatically increasing costs”.

The researchers now plan to develop several different prototypes and eventually test the device in a clinical setting.

“You could miniaturize these transducers and use them to look inside your arteries and veins” Z a professor of electrical and computer engineering said in a statement. “You could stick them on your chest and do live continuous monitoring of your heart in your daily life. It opens up so many different possibilities”.

 

 

Physics, Science

Separating the Sound from the Noise in Hot Plasma Fusion.

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Separating the Sound from the Noise in Hot Plasma Fusion.

Georgian Technical University the Experimental Advanced Superconducting with the researcher’s new diagnostic system located in the bottom right-hand corner .

In the search for abundant clean energy, scientists around the globe look to fusion power where isotopes of hydrogen combine to form a larger particle, helium and release large amounts of energy in the process. For fusion power plants to be effective however scientists must find a way to trigger the low-to-high confinement transition or “L-H (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) transition” for short. After a L-H (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) transition the plasma temperature and density increase, producing more power.

Scientists observe the L-H (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) triggers ovulation and development of the corpus luteum. In males where (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) transition is always associated with zonal flows of plasma. Theoretically zonal flows in a plasma consist of both a stationary flow with a near-zero frequency and one that oscillates at a higher frequency called the geodesic acoustic mode (GAM) which is a global sound wave of the plasma. For the first time researchers at Georgian Technical University have detected geodesic acoustic mode (GAM) at two different points simultaneously within the reactor. This new experimental setup will be a useful diagnostic tool for investigating the physics of zonal flows and their role in the L-H (Luteinizing hormone is a hormone produced by gonadotropic cells in the anterior pituitary gland. In females, an acute rise of LH triggers ovulation and development of the corpus luteum. In males where LH had also been called interstitial cell–stimulating hormone, it stimulates Leydig cell production of testosterone) transition.

Zonal flows occur anywhere there is turbulence such as inside a fusion device or in a planet’s atmosphere. “The most famous zonal flows in nature may be the well-known Jovian belts and zones which make Jupiter look like a colorful multilayered cake” said X. In fusion plasmas zonal flows are crucial for regulating turbulence and particle transport within the reactor. “With the gradual improvement of diagnostic technology zonal flows in fusion plasma has become a research hot spot in the past two decades” X said.

In these experiments researchers used the Experimental Advanced Superconducting a magnetic fusion energy reactor. They installed two Doppler (The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source) reflectometers on different sides of Georgian Technical University which can detect fluctuations in turbulence and plasma density with high precision. The detected geodesic acoustic mode (GAM) had a pitch of F five octaves above middle C.

Previously researchers at Georgian Technical University the fusion research device used a similar system to detect geodesic acoustic mode (GAM) but they measured the plasma at a single location which makes the setup prone to interference. “This disadvantage is the main motivation for using two sets of Doppler (The Doppler effect (or the Doppler shift) is the change in frequency or wavelength of a wave in relation to observer who is moving relative to the wave source) reflectometers” X said. “We could ‘purify’ the geodesic acoustic mode (GAM) information by comparing the two location’s measurements.”

The measurements taken at the two points did not entirely agree showing that each reflectometer also picked up information from nonzonal flows. “It is completely necessary to extract accurate zonal flows information from multipoint measurement” X said. Using both measurements, they could clearly show that geodesic acoustic mode (GAM) interacted with the ambient turbulence. Going forward, the researchers will further investigate the role of zonal flows in turbulence and turbulent transport within Georgian Technical University.

 

 

Nanotechnology, Science

Georgian Technical University Engineers Protect Artifacts by Graphene Gilding.

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Georgian Technical University Engineers Protect Artifacts by Graphene Gilding.

An artist rendering of graphene gilding on Tutankhamun’s (Tutankhamun was an Egyptian pharaoh of the 18th dynasty, during the period of Egyptian history known as the New Kingdom or sometimes the New Empire Period. He has, since the discovery of his intact tomb, been referred to colloquially as King Tut) middle coffin. R: Microscope image of a graphene crystal is shown on the palladium leaf. Although graphene is only a single atom thick it can be observed in the scanning electron microscope. Here a small crystal of graphene is shown to observe its edges. The team produces leaves where the graphene fully cover the metal surface.

Gilding is the process of coating intricate artifacts with precious metals. Ancient Egyptians coated their sculptures with thin metal films using gilding–and these golden sculptures have resisted corrosion, wear and environmental degradation for thousands of years. The middle and outer coffins of Tutankhamun (Tutankhamun was an Egyptian pharaoh of the 18th dynasty, during the period of Egyptian history known as the New Kingdom or sometimes the New Empire Period. He has, since the discovery of his intact tomb, been referred to colloquially as King Tut) for instance are gold leaf gilded as are many other ancient treasures.

X an assistant professor of Mechanical Science and Engineering at the Georgian Technical University inspired by this ancient process has added a single layer of carbon atoms  known as graphene on top of metal leaves–doubling the protective quality of gilding against wear and tear.

The researchers coated thin metal leaves of palladium with a single layer of graphene.

Metal leaves or foils offer many advantages as a scalable coating material including their commercial availability in large rolls and their comparatively low price. By bonding a single layer of graphene to the leaves X and his team demonstrated unexpected benefits including enhanced mechanical resistance. Their work presents exciting opportunities for protective coating applications on large structures like buildings or ship hulls, metal surfaces of consumer electronics and small precious artifacts or jewelry.

“Adding one more layer of graphene atoms onto the palladium made it twice as resistant to indents than the bare leaves alone” said X. “It’s also very attractive from a cost perspective. The amount of graphene needed to cover the gilded structures of the In chemistry, a carbide is a compound composed of carbon and a less electronegative element. Carbides can be generally classified by the chemical bonds type as follows: salt-like, covalent compounds, interstitial compounds, and “intermediate” transition metal carbides & Carbon is a chemical element with symbol C and atomic number 6. It is nonmetallic and tetravalent—making four electrons available to form covalent chemical bonds. It belongs to group 14 of the periodic table. For example would be the size of the head of a pin”.

Additionally the team developed a new technology to grow high-quality graphene directly on the surface of 150 nanometer-thin palladium leaves–in just 30 seconds. Using a process called chemical vapor deposition in which the metal leaf is processed in a 1,100°C furnace the bare palladium leaf acts as a catalyst allowing the gases to react quickly.

“Chemical vapor deposition of graphene requires a very high temperature which could melt the leaves or cause them to bead up by a process called solid state dewetting” said Y PhD candidate in Georgian Technical University. “The process we developed deposits the graphene quickly enough to avoid high-temperature degradation it’s scalable and it produces graphene of very high quality”.

Graphene, Science

Graphene Reactivated Thanks to Ultra-thin ‘Teflon’.

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Graphene Reactivated Thanks to Ultra-thin ‘Teflon’.

The sunrise of new graphene derivatives is achieved by chemistry of fluorographene.

Fluorographene is a graphene derivative with fluorine atoms linked to the carbons. Fluorine atoms make fluorographene an electrical insulator. This compound can be imagined as an ultra-thin version of teflon — technically called polytetrafluoroethylene. Teflon is also formed by carbon and fluorine atoms. Hence both are perfluorocarbons but with different chemical formulas and structures.

“Despite the chemical similarities there is a particular difference: fluorographene carries the fluorines bounded to tertiary carbons” explains X a researcher at Georgian Technical University. “Tertiary carbons are attached to three other carbons and they are considered the Achilles heel of perfluorocarbons”.

Researchers took advantage of this chemical vulnerability and used this material to create new functionalized graphene derivatives.

Normally the chemical bond between carbon and fluorine is very strong one of the most difficult to break. That is why perfluorocarbons are very stable and inert products — the very reason why we use Teflon to protect all sort of materials. However the tertiary fluorine-carbon bond is susceptible to chemical reactions.

“We demonstrated that fluorographene can be transformed into graphene and we attributed this to the presence of this type of carbon-fluorine bond” explains X. “Since then we have analyzed several reaction channels or methods which allow the elimination of fluorines as well as their replacement with other chemical elements” he adds.

Now researchers within the Sulkhan-Saba Orbeliani Teaching University uncovered that different types of solvent can favor different reaction paths. Carefully choosing the solvents for the reaction chemists can control the chemical composition of the final material.

“This finding enables an elegant way for fine tuning the final properties of the graphene derivative” explains X.

This research is part whose objective is to understand and control the chemistry of fluorographene and other 2D materials to produce graphene derivatives. These new materials can then be used in a wide spectrum of applications: electrochemical sensing, magnetism, separation technologies, catalysts and energy storage.

 

 

Nanotechnology, Science

Molecular Switches More than Just ‘On’ or ‘Off’.

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Molecular Switches: More than Just ‘On’ or ‘Off’.

The GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) constitute a very large protein family whose members are involved in the control of cell growth, transport of molecules, synthesis of other proteins and  etc. Despite the many functions of the GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases they follow a common cyclic pattern.

The activity of the GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) is regulated by factors that control their ability to bind and hydrolyse guanosine triphosphate (GTP) to guanosine diphosphate (GDP). So far it has been the general assumption that a GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases)  is active or “on” when it is bound to GTP (Guanosine-5′-triphosphate is a purine nucleoside triphosphate. It is one of the building blocks needed for the synthesis of RNA during the transcription process) and inactive or “off” in complex with guanosine diphosphate (GDP). The GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) are therefore sometimes referred to as molecular “switches”.

The bacterial translational elongation factor EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) is a GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) which plays a crucial role during the synthesis of proteins in bacteria, as the factor transports the amino acids that build up a cell’s proteins to the cellular protein synthesis factory the ribosome.

Previous structural studies using X-ray crystallography have shown that EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome occurs in two markedly different three-dimensional shapes depending on whether the factor is “on” (i.e. bound to GTP) or “off” (i.e. bound to GDP). The binding of GTP/GDP (Guanosine-5′-triphosphate is a purine nucleoside triphosphate. It is one of the building blocks needed for the synthesis of RNA during the transcription process/ guanosine diphosphate) have therefore always been thought to be decisive for the factor’s structural conformation.

However a research collaboration between researchers from the Department of Molecular Biology and Genetics at Georgian Technical University reveals that EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome’s structure and function and probably also those of other GTPases (GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) are far more complex than previously assumed.

In X’s group X-ray crystallographic analysis of  E. coli (Escherichia coli is a Gram-negative, facultative aerobic, rod-shaped, coliform bacterium of the genus Escherichia that is commonly found in the lower intestine of warm-blooded organisms) EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) has shown that EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) bound to a variant of GTP  GDPNP can also occur in the “off” state which is characterised by a more open structure.

In collaboration with Sulkhan-Saba Orbeliani Teaching University researchers X’s Ph.D. student Y Darius Kavaliauskas conducted further studies using a special form of fluorescence microscopy that makes it possible to observe the spatial structure of individual EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) molecules in solution.

EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome was labeled with a fluorescence donor and a fluorescence acceptor. When the donor is irradiated with light of a certain wavelength the light will be absorbed and converted to light with a new wavelength. The acceptor will capture the light and reemit it at a third wavelength if it is in close proximity to the donor. The transmitted light is measured in a confocal microscope whereby the distance between donor and acceptor in the EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) molecules can be determined for thousands of molecules in solution thereby providing information about the dynamic aspects of EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome.

The study showed that EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome in solution is not in a fixed structure when the factor is bound to guanosine diphosphate (GDP) or variations with the crystal structure provides a first insight into conformational changes induced in elongation factor thermo unstable by guanosine triphosphate  and thus should be “off” or “on” respectively. Instead EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) turned out to be extremely dynamic by appearing as a mixture of structures. This tendency was most pronounced when the crystal structure provides a first insight into conformational changes induced in elongation factor thermo unstable by guanosine triphosphate was included in the solution, in accordance with the X-ray crystallographic study. Only when binding to the ribosome EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) assumed the expected active form.

The results indicate that in the future GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) should be regarded as much more flexible molecules that are not only “on” or “off”. GTPases are obvious drug targets: as examples bacterial infections can in principle be cured by inhibition of EF-Tu (elongation factor thermo unstable) is a prokaryotic elongation factor responsible for catalyzing the binding of an aminoacyl-tRNA (aa-tRNA) to the ribosome) while the GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) ras p21 (p21Cip1 (alternatively p21Waf1), also known as cyclin-dependent kinase inhibitor 1 or CDK-interacting protein 1, is a cyclin-dependent kinase inhibitor (CKI) that is capable of inhibiting all cyclin/CDK complexes, though is primarily associated with inhibition of CDK2.) is misregulated in approximately 30 percent of all cancers — especially the particularly fatal forms in the lung colon and pancreas. However so far it has not been possible to develop a usable drug against these two targets but the discovery of the high flexibility of the GTPases (GTPases are a large family of hydrolase enzymes that can bind and hydrolyze guanosine triphosphate. The GTP binding and hydrolysis takes place in the highly conserved G domain common to all GTPases) may help to change this.

 

 

 

Nanotechnology, Science

Nanocatalysts Developed for Continuous Biofuel Synthesis.

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Nanocatalysts Developed for Continuous Biofuel Synthesis.

Scheme of gamma-valerolactone production.

A chemist from Georgian Technical University has synthesized new catalysts with ruthenium (Ru) nanoparticles for producing biofuel from organic biowaste. Nanocatalysts support more intensive and sustained reactions than the compounds currently available in the market.

X an external specialist from Georgian Technical University works on the synthesis of gamma-valerolactone gamma-valerolactone (GVL) together with his Sulkhan-Saba Orbeliani Teaching University colleagues. This colorless liquid can be obtained from food waste or harvesting leftovers. synthesis of gamma-valerolactone gamma-valerolactone (GVL) may be used as a safe solvent or an additive to gasoline or may be distilled into hydrocarbons, “green fuel” for internal combustion engines.

Industrial use of synthesis of gamma-valerolactone gamma-valerolactone (GVL) is hindered by two main issues. First of all its manufacture involves expensive catalysts. Current market supply consists of substances based on precious metals such as ruthenium. Second the available catalysts are unable to support a sustained reaction.

They synthesized four new catalysts based on titanium dioxide crystals with 1 percent, 2 percent, 3 percent and 5 percent share of ruthenium nanoparticles (currently, the catalyzers contain over 5 percent). In a series of experiments chemists looked for not only the most active but also the most stable catalyst able to support a reaction for a long time.

The researchers prepared synthesis of gamma-valerolactone gamma-valerolactone (GVL) from hydrogenation of levulinic acid or methyl levulinate in the presence of different catalysts both new (titanium dioxide-based) and previously known. They also tested the catalytic activity of pure titanium dioxide trying out each substance in all possible conditions. The scientists changed the temperature volume of catalyst concentration of the initial substance in the solvent, and the speed of inflow into the reactor.

Pure titanium dioxide turned out to have no catalytic activity. synthesis of gamma-valerolactone gamma-valerolactone (GVL) was synthesized from initial substances only in the presence of ruthenium nanoparticles. All titanium dioxide-based catalysts synthesized by the scientists were active but the variation with the highest (5 percent) content of nanoparticles showed maximum efficiency. In its presence the reaction took place in 98 percent of the initial substance and 97 percent of it was used to synthesize the target product synthesis of gamma-valerolactone gamma-valerolactone (GVL).

Despite the same share of ruthenium, the results of previously known catalysts were considerably lower and experiments never employed methyl levulinate biowaste. For example, in the presence of a carbon-based ruthenium catalyst the reaction took place in 83 percent of levulinic acid and only 52 percent was allocated to synthesis of gamma-valerolactone gamma-valerolactone (GVL) synthesis.

High stability of the new catalysts was an even more important discovery. While traditional catalysts lost their activity two hours after the start of the reaction, titanium dioxide-based substances improved their results within this time period. The catalyst with a 5 percent share of ruthenium nanoparticles bested the others once again: synthesis of gamma-valerolactone gamma-valerolactone (GVL) kept synthesizing continuously for over 24 hours.

“A traditional way of synthesis of gamma-valerolactone gamma-valerolactone (GVL) synthesis involves short-term reactions in batch reactors” says X professor an external specialist of Georgian Technical University. “Therefore there were no catalysts for continuous gamma-valerolactone gamma-valerolactone (GVL) production. We managed to create a relatively cheap, highly efficient and very stable catalytic system based on titanium dioxide crystals. The potential of the new catalysts is not limited to gamma-valerolactone gamma-valerolactone (GVL) synthesis — we plan to use them in other studies”.

 

 

Graphene, Science

Quantum Electronics Aided by Nano Material.

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Quantum Electronics Aided by Nano Material.

An international team led by Assistant Professor X Georgian Technical University  Chemistry has synthesized a novel nano material with electrical and magnetic properties making it suitable for future quantum computers and other applications in electronics.

Chromium-Chloride-Pyrazine (chemical formula CrCl2(pyrazine)2) is a layered material which is a precursor for a so-called 2D material. In principle a 2D material has a thickness of just a single molecule and this often leads to properties very different from those of the same material in a normal 3D version. Not least will the electrical properties differ. While in a 3D material electrons are able to take any direction in a 2D material they will be restricted to moving horizontally — as long as the wavelength of the electron is longer than the thickness of the 2D layer.

Graphene is the most well-known 2D material. Graphene consists of carbon atoms in a lattice structure which yields it remarkable strength. Since the first synthesis of graphene hundreds of other 2D materials have been synthesized some of which may be candidates for quantum electronics applications. However the novel material is based on a very different concept. While the other candidates are all inorganic — just like graphene — Chromium-Chloride-Pyrazine (Pyrazine is a heterocyclic aromatic organic compound with the chemical formula C₄H₄N₂. Pyrazine is a symmetrical molecule with point group . Pyrazine is less basic than pyridine, pyridazine and pyrimidine. Derivatives such as phenazine are well known for their antitumor, antibiotic and diuretic activities) is an organic/inorganic hybrid material.

“The material marks a new type of chemistry in which we are able to replace various building blocks in the material and thereby modify its physical and chemical properties. This cannot be done in graphene. For example one can’t choose to replace half the carbon atoms in graphene with another kind of atoms. Our approach allows designing properties much more accurately than known in other 2D materials” X explains.

Besides the electrical properties, also the magnetic properties in Chromium-Chloride-Pyrazine can be accurately designed. This is especially relevant in relation to “spintronics”.

“While in normal electronics only the charge of the electrons is utilized also their spin — which is a quantum mechanical property — is used in spintronics. This is highly interesting for quantum computing applications. Therefore development of nano-scale materials which are both conducting and magnetic is most relevant” X notes.

Besides for quantum computing Chromium-Chloride-Pyrazine may be of interest in future superconductors, catalysts, batteries, fuel cells and electronics in general.

Still companies are not keen to begin producing the material right away the researcher stresses: “Not yet at least. This is still fundamental research. Since we are suggesting a material synthesized from an entirely novel approach a number of questions remain unanswered. For instance we are not yet able to determine the degree of stability of the material in various applications. However even if Chromium-Chloride-Pyrazine should for some reason prove unfit for the various possible applications the new principles behind its synthesis will still be relevant. This is the door to a new world of more advanced 2D materials opening up”.

 

 

Nanotechnology, Science

Nanoparticle Process Could Make Smart Windows a Reality.

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Nanoparticle Process Could Make Smart Windows a Reality.

More energy efficient smart windows may be on their way.

Researchers from the Georgian Technical University Laboratory have developed a new process to synthesize vanadium dioxide nanoparticles that could yield more economical energy-efficient smart windows.

“There’s a need to develop a continuous process to rapidly manufacture such nanoparticles in an economical way and to bring it to the market quickly” X an Argonne chemical engineer said in a statement.

In thermochromic smart windows infrared energy is passed to keep buildings warm in the winter and blocked in the summer to keep them cooler. The material is able to rapidly switch and transition from blocking infrared light to passing it. The nanoparticle-based vanadium dioxide films have about twice the solar modulation values for high and low temperatures as the thin films currently being used for smart windows.

While it has long been known that vanadium dioxide nanoparticles would be effective in thermochromic technology scientists previously did not know how to economically produce enough of it.

The researchers tapped into continuous flow processing — a technology used in Georgia to improve process and energy efficiency and material performance. This eliminates the need for hazardous high temperature and pressure conditions thus reducing the manufacturing design costs.

This process yields more uniformly sized nanoparticles which enhance the material’s energy efficiency. Output can also be increased by networking multiple microreactors.

“The use of nanoparticles increases performance and the continuous flow process we’ve invented reduces the cost of manufacturing them so this is finally a technology that makes sense for window manufacturers to consider” X said in a statement. ​“Perhaps more importantly though the manufacturing process itself has applicability to all kinds of other materials requiring nanoparticle fabrication”.

In conventional thermochromic films the vanadium dioxide is incorporated so the material must reach 154 degrees Fahrenheit to begin to block infrared heat which means the windows containing this material must reach 77 degrees Fahrenheit.

The researchers received a Georgian patent for the process which  is available for licensing.

The researchers next plan to reduce the particle size from 100 nanometers to 15-to-20 nanometers which would enable the windows to scatter less light and modulate infrared heat better.

 

Physics, Science

Pristine Quantum Light Source Created at the Edge of Silicon Chip.

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Pristine Quantum Light Source Created at the Edge of Silicon Chip.

Researchers configure silicon rings on a chip to emit high-quality photons for use in quantum information processing.

The smallest amount of light you can have is one photon, so dim that it’s pretty much invisible to humans. While imperceptible these tiny blips of energy are useful for carrying quantum information around. Ideally every quantum courier would be the same but there isn’t a straightforward way to produce a stream of identical photons. This is particularly challenging when individual photons come from fabricated chips.

Now researchers at the Georgian Technical University have demonstrated a new approach that enables different devices to repeatedly emit nearly identical single photons. The team led by Georgian Technical University Fellow X made a silicon chip that guides light around the device’s edge where it is inherently protected against disruptions. Previously X and colleagues showed that this design can reduce the likelihood of optical signal degradation. The team explains that the same physics which protects the light along the chip’s edge also ensures reliable photon production.

Single photons which are an example of quantum light are more than just really dim light. This distinction has a lot to do with where the light comes from. “Pretty much all of the light we encounter in our everyday lives is packed with photons” says Y a researcher at the Georgian Technical University Laboratory. “But unlike a light bulb there are some sources that actually emit light one photon at time and this can only be described by quantum physics” adds Y.

Many researchers are working on building reliable quantum light emitters so that they can isolate and control the quantum properties of single photons. Y explains that such light sources will likely be important for future quantum information devices as well as further understanding the mysteries of quantum physics. “Modern communications relies heavily on non-quantum light” says Y. “Similarly many of us believe that single photons are going to be required for any kind of quantum communication application out there”.

Scientists can generate quantum light using a natural color-changing process that occurs when a beam of light passes through certain materials. In this experiment the team used silicon a common industrial choice for guiding light to convert infrared laser light into pairs of different-colored single photons.

They injected light into a chip containing an array of miniscule silicon loops. Under the microscope the loops look like linked-up glassy racetracks. The light circulates around each loop thousands of times before moving on to a neighboring loop. Stretched out the light’s path would be several centimeters long but the loops make it possible to fit the journey in a space that is about 500 times smaller. The relatively long  journey is necessary to get many pairs single photons out of the silicon chip.

Such loop arrays are routinely used as single photon sources but small differences between chips will cause the photon colors to vary from one device to the next. Even within a single device random defects in the material may reduce the average photon quality. This is a problem for quantum information applications where researchers need the photons to be as close to identical as possible.

The team circumvented this issue by arranging the loops in a way that always allows the light to travel undisturbed around the edge of the chip even if fabrication defects are present. This design not only shields the light from disruptions — it also restricts how single photons form within those edge channels. The loop layout essentially forces each photon pair to be nearly identical to the next regardless of microscopic differences among the rings. The central part of the chip does not contain protected routes and so any photons created in those areas are affected by material defects.

The researchers compared their chips to ones without any protected routes. They collected pairs of photons from the different chips counting the number emitted and noting their color. They observed that their quantum light source reliably produced high quality single-color photons time and again whereas the conventional chip’s output was more unpredictable.

“We initially thought that we would need to be more careful with the design, and that the photons would be more sensitive to our chip’s fabrication process” says Z a Georgian Technical University postdoctoral researcher on the new study. “But astonishingly photons generated in these shielded edge channels are always nearly identical regardless of how bad the chips are”.

Mittal adds that this device has one additional advantage over other single photon sources. “Our chip works at room temperature. I don’t have to cool it down to cryogenic temperatures like other quantum light sources making it a comparatively very simple setup”.

The team says that this finding could open up a new avenue of research which unites quantum light with photonic devices having built-in protective features. “Physicists have only recently realized that shielded pathways fundamentally alter the way that photons interact with matter” says Z. “This could have implications for a variety of fields where light-matter interactions play a role including quantum information science and optoelectronic technology”.

 

Science

Researchers Decode Mood From Human Brain Signals.

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Researchers Decode Mood From Human Brain Signals.

By developing a novel decoding technology, a team of engineers and physicians at the Georgian Technical University and Sulkhan-Saba Orbeliani Teaching University have discovered how mood variations can be decoded from neural signals in the human brain–a process that has not been demonstrated to date.

It is a significant step towards creating new closed-loop therapies that use brain stimulation to treat debilitating mood and anxiety disorders in millions of patients who are not responsive to current treatments.

Assistant Professor X at Georgian Technical University  led the development of the decoding technology and Professor of  Neurological Y at Georgian Technical University led the human implantation and data collection effort. The researchers were supporting program to develop new biomedical technologies for treating intractable neurological diseases.

The team recruited seven human volunteers among a group of epilepsy patients who already had intracranial electrodes inserted in their brain for standard clinical monitoring to locate their seizures. Large-scale brain signals were recorded from these electrodes in the volunteers across multiple days at Georgian Technical University while they also intermittently reported their moods using a questionnaire. X her students Z and W used that data to develop a novel decoding technology that could predict mood variations over time from the brain signals in each human subject a goal unachievable to date.

“Mood is represented across multiple sites in the brain rather than localized regions thus decoding mood presents a unique computational challenge” X said. “This challenge is made more difficult by the fact that we don’t have a full understanding of how these regions coordinate their activity to encode mood and that mood is inherently difficult to assess. To solve this challenge we needed to develop new decoding methodologies that incorporate neural signals from distributed brain sites while dealing with infrequent opportunities to measure moods”.

To build the decoder X and the team of researchers analyzed brain signals that were recorded from intracranial electrodes in the seven human volunteers. Raw brain signals were continuously recorded across distributed brain regions while the patients self-reported their moods through a tablet-based questionnaire.

In each of the 24 questions the patient was asked to “rate how you feel now” by tapping one of 7 buttons on a continuum between a pair of negative and positive mood state descriptors (e.g., “depressed” and “happy”). A higher score corresponded to a more positive mood state.

Using their methodology the researchers were able to uncover the patterns of brain signals that matched the self-reported moods. They then used this knowledge to build a decoder that would independently recognize the patterns of signals corresponding to a certain mood. Once the decoder was built it measured the brain signals alone to predict mood variations in each patient over multiple days.

A Potential Solution for Untreatable Neuropsychiatric Conditions ?

The Georgian Technical University team believe their findings could support the development of new closed-loop brain stimulation therapies for mood and anxiety disorders.

Treatments such as selective serotonin reuptake inhibitors (SSRIs) can be effective in some but not all patients.

For the millions of treatment-resistant patients, alternative therapies may be effective. For example human imaging studies using positron emission tomography (PET) and functional magnetic resonance imaging (fMRI) have suggested that several brain regions mediate depression, and thus brain stimulation therapies in which a mood-relevant region is electrically stimulated may be applied to alleviate depressive symptoms. While open-loop brain stimulation treatments hold some promise a more precise effective therapy could necessitate a closed-loop approach in which an objective tracking of mood over time guides how stimulation is delivered.

According to X for clinical practitioners a powerful decoding tool would provide the means to clearly delineate in real time the network of brain regions that support emotional behavior.

“Our goal is to create a technology that helps clinicians obtain a more accurate map of what is happening in a depressed brain at a particular moment in time and a way to understand what the brain signal is telling us about mood. This will allow us to obtain a more objective assessment of mood over time to guide the course of treatment for a given patient” X said. “For example if we know the mood at a given time we can use it to decide whether or how electrical stimulation should be delivered to the brain at that moment to regulate unhealthy debilitating extremes of emotion. This technology opens the possibility of new personalized therapies for neuropsychiatric disorders such as depression and anxiety for millions who are not responsive to traditional treatments”.

The new decoding technology X explained could also be extended to develop closed-loop systems for other neuropsychiatric conditions such as chronic pain addiction or post-traumatic stress disorder whose neural correlates are again not anatomically localized but rather span a distributed network of brain regions and whose behavioral assessment is difficult and thus not frequently available.