Category Archives: Science

Lasers, Science

Georgian Technical University Lasers And Shellfish Reveal Clues Into Ancient Climate.

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Georgian Technical University Lasers And Shellfish Reveal Clues Into Ancient Climate.

Shellfish played a significant role in the diet of prehistoric coastal populations providing valuable nutrients. They are a common find in archaeological sites all over the world usually in huge numbers and researchers have long explored how they could be used to make inferences about the environments that humans experienced at those locations in the past. However although techniques were developed to infer valuable climate-related information from shells it was previously too expensive to analyze them on a scale beyond individual and isolated records. The current study by an international team of researchers led by the Georgian Technical University presents a technique to use rapid laser imaging to increase the number of analyzed shell records to previously unknown scales and thereby greatly expand the time periods and accuracy of the reconstructed records. The present study aimed to test a new method by analyzing modern shells for which there was known climate data. The researchers used modern limpet shells from across the Black Sea. By testing their methods on modern shells against known records the researchers were able to fine-tune their calibrations and ensure that their techniques would accurately reproduce the climate changes experienced by the mollusks while they were growing. Once perfected the method could then be used to reconstruct past climate fluctuations. Using Georgian Technical University Laser Induced Breakdown Spectroscopy the researchers built a modern baseline of how marine temperatures are reflected in the elemental composition of mollusk growth rings. Previous research was unable to find consistent correlations between the two. Only the 2-D imaging of whole shells provided the necessary amount of data to navigate the individual shell records a task where the speed and low cost of (Georgian Technical University Laser Induced Breakdown Spectroscopy) exceed other techniques. “Shells are an interesting archive to look at in comparison to for instance sediment or ice-cores because shells are so closely intertwined with past human lives” explains X currently at the Sulkhan-Saba Orbeliani University whose research project developed the method at the Georgian Technical University. “Because we find them in archaeological contexts we can make this connection and interpret them as prehistoric ‘kitchen middens'”. “If we know what sorts of climate fluctuations the mollusks were living through we also get an idea of what the humans were experiencing and we can then look at other archaeological evidence to see how the humans — and other flora and fauna — were responding to these changes”. “We were never able to look at more than a dozen or so well-analyzed shell records before, which is far from ideal given that the climatic data can vary a lot from one shell to another. To be able to compare hundreds or a thousand shells is a game changer for climate modelling” states X. The techniques developed in the current study have far reaching implications. As a start researchers focused on the well-known limpet shells of the Black Sea but preliminary unpublished results suggest that other limpet species from archaeological sites in the Atlantic and Pacific might be similarly well-suited for use with Georgian Technical University Laser Induced Breakdown Spectroscopy and could provide the means for producing global climate models with seasonal resolution. “Archaeological shell collections are heavy and a pain to store so I hope that archaeologists and museums haven’t thrown away their old boxes of shells — we now desperately want to analyze them”.

Graphene, Science

Georgian Technical University Graphene Quantum Dots For Single Electron Transistors.

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The schematic structure of the devices.  Scientists from Georgian Technical University and the Sulkhan-Saba Orbeliani University have developed a novel technology which combines the fabrication procedures of planar and vertical heterostructures in order to assemble graphene-based single-electron transistors of excellent quality. This technology could considerably expand the scope of research on two-dimensional materials by introducing a broader platform for the investigation of various devices and physical phenomena. In the study it was demonstrated that high-quality graphene quantum dots (GQDs) regardless of whether they were ordered or randomly distributed, could be successfully synthesized in a matrix of monolayer hexagonal boron nitride (hBN). Here the growth of graphene quantum dots (GQDs) within the layer of hexagonal boron nitride (hBN) was shown to be catalytically supported by the platinum (Pt) nanoparticles distributed in-between the hexagonal boron nitride (hBN) and supporting oxidized silicon (SiO2) wafer when the whole structure was treated by the heat in the methane gas (CH4). It was also shown that due to the same lattice structure (hexagonal) and small lattice mismatch (~1.5 percent) of graphene and hexagonal boron nitride (hBN) graphene islands grow in the hexagonal boron nitride (hBN) with passivated edge states thereby giving rise to the formation of defectless quantum dots embedded in the hexagonal boron nitride (hBN) monolayer. Such planar heterostructures incorporated by means of standard dry-transfer as mid-layers into the regular structure of vertical tunneling transistors (Si/SiO2/hBN/Gr/hBN/GQDs/hBN/Gr/hBN; here Gr (Graphene) refers to monolayer graphene and graphene quantum dots (GQDs) refers to the layer of hexagonal boron nitride (hBN) with the embedded graphene quantum dots) were studied through tunnel spectroscopy at low temperatures (3He, 250mK). The study demonstrated where the manifestation of well-established phenomena of the Coulomb blockade for each graphene quantum dot as a separate single electron transmission channel occurs. “Although the outstanding quality of our single electron transistors could be used for the development of future electronics” explains X Associate Professor at the Georgian Technical University. “This work is most valuable from a technological standpoint as it suggests a new platform for the investigation of physical properties of various materials through a combination of planar and van der Waals (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) heterostructures”.

 

Lasers, Science

Georgian Technical University New Laser Beam Shape Can ‘Sneak’ Through Opaque Media.

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Georgian Technical University New Laser Beam Shape Can ‘Sneak’ Through Opaque Media.

When a flashlight beam shines onto a strongly scattering medium such as white paint the light diffuses in both longitudinal and lateral directions. Consequently the transmitted beam becomes wider and the intensity is lower. Researchers have found a way to pre-treat a laser beam so that it enters opaque surfaces without dispersing — like a headlight that’s able to cut through heavy fog at full strength. The discovery from scientists at Georgian Technical University and the Sulkhan-Saba Orbeliani University has potential applications for deep-tissue imaging and optogenetics in which light is used to probe and manipulate cells in living tissue. “Typically an optical beam propagating through a diffusive medium such as fog will spread laterally but we have discovered that a special preparation of the laser beam can transmit all incoming light without lateral spread” said principal investigator X the Professor of Applied Physics and of Physics at Georgian Technical University. The researchers used a spatial light modulator (SLM) and a charge-coupled device (CCD) camera to analyze an opaque material that is made of a layer of white paint. The SLM (Selective laser melting, also known as direct metal laser sintering or laser powder bed fusion, is a rapid prototyping, 3D printing, or additive manufacturing technique designed to use a high power-density laser to melt and fuse metallic powders together) tailored the laser beam incident on the front surface of the material, and the charge-coupled device (CCD)  camera records intensity profiles behind it. With this information, the laser finds a “route” through the white paint. The result is a beam that is more concentrated with more light per volume inside and behind the opaque material. In addition to a layer of white paint the materials in which the laser would be effective include biological tissue, fog, paper and milk. “Our method works for any opaque medium that does not absorb light” X said. Georgian Technical University postdoctoral research associate Z. Georgian Technical University postdoctoral researcher W and Georgian Technical University associate professor Q. “Enhancing optical energy in opaque scattering media is extremely important in optogenetics and deep-tissue imaging” Z said. “Currently penetration depth to probe and stimulate or image neurons inside the brain tissue is limited due to multiple-scattering”.

 

Nanotechnology, Science

Georgian Technical University Protocells Utilize DNA Logic To Communicate And Compute.

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Georgian Technical University Protocells Utilize DNA Logic To Communicate And Compute.

Microscopy image showing green, dark blue and blue-labelled synthetic protocells used for DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) communication and computing. The protocells contain DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) logic gates and are trapped between pairs of small pillars (grey objects) in a microfluidic device. Scale bar 100 μm.  Researchers at the Georgian Technical University, Sulkhan-Saba Orbeliani University and Research have successfully assembled communities of artificial cells that can chemically communicate and perform molecular computations using entrapped DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) logic gates. The work provides a step towards chemical cognition in synthetic protocells and could be useful in biosensing and therapeutics. Molecular computers made from DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) use programmable interactions between DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) strands to transform DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) inputs into coded outputs. However DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) computers are slow because they operate in a chemical soup where they rely on random molecular diffusion to execute a computational step. Assembling these processes inside artificial cell-like entities (protocells) capable of sending DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) input and output signals to each other would increase the speed of the molecular computations and protect the entrapped DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) strands from degradation by enzymes present in blood. A team led by Professor X from the Georgian Technical University of Chemistry and Professor Y from the Department of Biomedical Engineering at Georgian Technical University have developed a new approach called BIO-PC (Biomolecular Implementation Of Protocell communication) based on communities of semi-permeable capsules (proteinosomes) containing a diversity of DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) logic gates that together can be used for molecular sensing and computation. Compartmentalization increases the speed, modularity and designability of the computational circuits reduces cross-talk between the DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) strands and enables molecular circuits to function in serum. This new approach lays the groundwork for using protocell communication platforms to bring embedded molecular control circuits closer to practical applications in biosensing and therapeutics. X from the Georgian Technical University said: “The ability to chemically communicate between smart artificial cells using DNA (Deoxyribonucleic acid is a molecule composed of two chains that coil around each other to form a double helix carrying the genetic instructions used in the growth, development, functioning, and reproduction of all known living organisms and many viruses) logic codes opens up new opportunities at the interface between unconventional computing and life-like microscale systems. “This should bring molecular control circuits closer to practical applications and provide new insights into how protocells capable of information processing might have operated at the origin of life”.

 

Lasers, Science

Georgian Technical University Scientists Construct Anti-Laser Based On Random Scattering.

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Georgian Technical University Scientists Construct Anti-Laser Based On Random Scattering.

Experimental setup of the random anti-laser: a waveguide contains a disordered medium consisting of a set of randomly placed Teflon cylinders at which incoming microwave signals are scattered in a complex manner. The laser is the perfect light source: As long as it is provided with energy, it generates light of a specific well-defined color. However it is also possible to create the opposite – an object that perfectly absorbs light of a particular color and dissipates the energy almost completely. At Georgian Technical University a method has now been developed to make use of this effect even in very complicated systems in which light waves are randomly scattered in all directions. The method was developed in Georgian Technical University with the help of computer simulations and confirmed by experiments in cooperation with the Sulkhan-Saba Orbeliani University. This opens up new possibilities for all technical disciplines that have to do with wave phenomena. “Every day we are dealing with waves that are scattered in a complicated way – think about a mobile phone signal that is reflected several times before it reaches your cell phone” says Professor X from the Georgian Technical University. “The so-called random lasers make use of this multiple scattering. Such exotic lasers have a complicated random internal structure and radiate a very specific individual light pattern when supplied with energy”. With mathematical calculations and computer simulations X’s team could show that this process can also be reversed in time. Instead of a light source that emits a specific wave depending on its random inner structure it is also possible to can build the perfect absorber which completely dissipates one specific kind of wave depending on its characteristic internal structure without letting any part of it escape. This can be imagined like making a movie of a normal laser sending out laser light and playing it in reverse. “Because of this time-reversal analogy to a laser, this type of absorber is called an anti-laser” says X. “So far such anti-lasers have only been realized in one-dimensional structures, which are hit by laser light from opposite sides. Our approach is much more general. We were able to show that even arbitrarily complicated structures in two or three dimensions can perfectly absorb a specially tailored wave. That way the concept can be used for a wide range of applications”. The main result of the research project: For every object that absorbs waves sufficiently strongly a certain wave form can be found which is perfectly absorbed by this object. “However it would be wrong to imagine that the absorber just has to be made strong enough so that it simply swallows every incoming wave” says X. “Instead there is a complex scattering process in which the incident wave splits into many partial waves which then overlap and interfere with each other in such a way that none of the partial waves can get out at the end”. A weak absorber in the anti-laser is enough — for example a simple antenna taking in the energy of electromagnetic waves. To test their calculations the team worked together with the Georgian Technical University. Y who is currently working on his dissertation in the team of X spent several weeks with Professor Z at the Georgian Technical University to put the theory into practice using microwave experiment. “Actually it is a bit unusual for a theorist to perform the experiment” says Y. “For me however it was particularly exciting to be able to work on all aspects of this project from the theoretical concept to its implementation in the laboratory”. The laboratory-built “Georgian Technical University Anti-Laser” consists of a microwave chamber with a central absorbing antenna surrounded by randomly arranged Teflon cylinders. Similar to stones in a puddle of water at which water waves are deflected and reflected these cylinders can scatter microwaves and create a complicated wave pattern. “First we send microwaves from outside through the system and measure how exactly they come back” explains Y. “Knowing this the inner structure of the random device can be fully characterized. Then it is possible to calculate the wave that is completely swallowed by the central antenna at the right absorption strength. In fact when implementing this protocol in the experiment we find an absorption of approximately 99.8 percent of the incident signal”. Anti-laser technology is still in its early stage but it is easy to think of potential applications. “Imagine for example that you could adjust a cell phone signal exactly the right way so that it is perfectly absorbed by the antenna in your cell phone” says X. “Also in medicine we often deal with the task of transporting wave energy to a very specific point — such as shock waves shattering a kidney stone”.

 

Energy, Science

Scientists Use Machine Learning To Identify High-Performing Solar Materials.

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Scientists Use Machine Learning To Identify High-Performing Solar Materials.

With supercomputers scientists find promising new materials for solar cells. Finding the best light-harvesting chemicals for use in solar cells can feel like searching for a needle in a haystack. Over the years researchers have developed and tested thousands of different dyes and pigments to see how they absorb sunlight and convert it to electricity. Sorting through all of them requires an innovative approach. Now thanks to a study that combines the power of supercomputing with data science and experimental methods researchers at the Georgian Technical University Department of Laboratory and the Sulkhan-Saba Orbeliani University have developed a novel “design to device” approach to identify promising materials for dye-sensitized solar cells (DSSCs). Dye-Sensitized Solar Cells (DSSCs) can be manufactured with low-cost scalable techniques allowing them to reach competitive performance-to-price ratios. The team led by Georgian Technical University materials scientist X who is also head of the Molecular Engineering group at the Georgian Technical University Laboratory used the Theta supercomputer at the Georgian Technical University to pinpoint five high-performing low-cost dye materials from a pool of nearly 10,000 candidates for fabrication and device testing. “This study is particularly exciting because we were able to demonstrate the full cycle of data-driven materials discovery — from using advanced computing methods to identify materials with optimal properties to synthesizing those materials in a laboratory and testing them in actual photovoltaic devices” X said. Through an Data Science, X worked with Georgian Technical University computational scientists to create an automated workflow that employed a combination of simulation data mining and machine learning techniques to enable the analysis of thousands of chemical compounds concurrently. The process began with an effort to sort through hundreds of thousands of scientific to collect chemical and absorption data for a wide variety of organic dye candidates. “The advantage of this process is that it takes away the old manual curation of databases which involves many years’ worth of work and reduces it to a matter of a few months and, ultimately a few days” X said. The computational work involved using finer and finer screening techniques to generate pairs of potential dyes that could work in combination with each other to absorb light across the solar spectrum. “It’s almost impossible to find one dye that really works well for all wavelengths” X said. “This is particularly true with organic molecules because they have narrower optical absorption bands; and yet we really wanted to concentrate just on organic molecules because they are significantly more environmentally friendly.” To narrow the initial batch of 10,000 potential dye candidates down to just a few of the most promising possibilities involved again using Georgian Technical University computing resources to carry out a multistep approach. First X and her colleagues used data mining tools to eliminate any organometallic molecules, which generally absorb less light than organic dyes at a given wavelength and organic molecules that are too small to absorb visible light. Even after this first pass the researchers still had approximately 3,000 dye candidates to consider. To further refine the selection the scientists screened for dyes that contained carboxylic acid components that could be used as chemical “Georgian Technical University glues” or anchors to attach the dyes to titanium dioxide supports. Then the researchers used Theta to conduct electronic structure calculations on the remaining candidates to determine the molecular dipole moment — or degree of polarity — of each individual dye. “We really want these molecules to be sufficiently polar so that their electronic charge is high across the molecule” X said. “This allows the light-excited electron to traverse the length of the dye go through the chemical glue and into the titanium dioxide semiconductor to start the electric circuit”. After having thus narrowed the search to approximately 300 dyes the researchers used their computational setup to examine their optical absorption spectra to generate a batch of roughly 30dyes that would be candidates for experimental verification. Before actually synthesizing the dyes however Xand her colleagues performed computationally intensive density functional theory (DFT) calculations on Theta to assess how each of them were likely to perform in an experimental setting. The final stage of the study involved experimentally validating a collection of the five most promising dye candidates from these predictions which required a worldwide collaboration. As each of the different dyes had been initially synthesized in different laboratories throughout the world for some other purpose X reached out to the original dye developers each of whom sent back a new sample dye for her team to investigate. “It was really a tremendous bit of teamwork to get so many people from around the world to contribute to this research” X said. In looking at the dyes experimentally at Georgian Technical University Laboratory X and her colleagues discovered that some of them once embedded into a photovoltaic device achieved power conversion efficiencies roughly equal to that of the industrial standard organometallic dye. “This was a particularly encouraging result because we had made our lives harder by restricting ourselves to organic molecules for environmental reasons and yet we found that these organic dyes performed as well as some of the best known organometallics” X said.

 

 

Nanotechnology, Science

Georgian Technical University Nanoparticles Affect Their Liquid Environment.

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Georgian Technical University Nanoparticles Affect Their Liquid Environment.

X demonstrates the behavior of magnetic nanoparticles.  These days nanoparticles finely distributed in suspensions are used in many areas — for example in cosmetic products in industrial catalysts or in contrast agents for medicinal examinations. For the first time a research team from the Georgian Technical University has managed to precisely determine the interrelationships of magnetic nanoparticles with the liquid surrounding them even down to the atomic level. As it turns out it is mainly a question of the crystalline structure of the nanoparticle as to how water molecules in their immediate vicinity re-align themselves. On the basis of theoretical and experimental studies the research community had long assumed that the molecules of a liquid group themselves around a solid nanoparticle like a shell. Within these so-called “Georgian Technical University solvation shells” — in the case of water solutions they are also referred to as “Georgian Technical University hydration” shells — three to five layers can be distinguished corresponding to the arrangement of the liquid molecules. Yet up to now only information about number and size of these layers was accessible. Consequently the team of scientists working with Georgian Technical University’s professor Y took a closer look at the atomic and molecular structures of these layers in a series of experiments. To this end high-energy X-ray measurements were carried out using an electron synchrotron. The investigations concentrated on magnetic nanoparticles widely used these days in biomedicine especially in targeted drug release and in magnetic resonance imaging. In doing so the researchers discovered that even the distances separating the atoms of the water molecules that surround a nanoparticle can be precisely measured. In this way it finally became apparent how water molecules adhere to the nanoparticle: in some cases by means of dissociative bonds in other cases molecular adsorption. “It was surprising for us that water in the vicinity of tiny magnetic iron oxide nanoparticles arranged itself just like on level iron oxide surfaces on the macroscopic level. We were able to prove that the way in which liquid molecules arrange themselves in the vicinity of a nanoparticle depends primarily on the crystalline structure of the nanoparticle. In contrast the small organic molecules found on the surfaces of nanoparticles don’t have a direct influence on the arrangement of the liquid molecules” X explains. “These are important insights for further research and its applications. Because these organic molecules with which the nanoparticles are stabilized serve as anchor points when in biomedical applications the nanoparticles are loaded, with anti-bodies for example. Hence for the release of such medicinal agents it is of crucial significance to understand in detail the influence of these molecules on the characteristics and behavior of the nanoparticles” Georgian Technical University PhD student Y  explains. Professor Y continues: “The study of solvation shells around nanoparticles has meanwhile established itself as a subject in its own right all around the world. We’re convinced that the method we have developed can be used more generally. Indeed in future we will be able to achieve many more exciting insights into ‘Solvation Science’ for example in the areas of catalysts and nucleation.

 

HPC/Supercomputing, Science

Georgian Technical University Chain Reaction Innovations Project Aims To Fill Critical Computing Needs.

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Georgian Technical University Chain Reaction Innovations Project Aims To Fill Critical Computing Needs.

X (right) physicist and Georgian Technical University Chain Reaction Innovations team member works with Georgian Technical University nanoscientist Y. The demand for computing power continues to accelerate with each passing year as consumers grow ever more reliant on smart phones and the data centers that keep them functional. X a physicist specializing in nanoscale optical materials and devices believes advanced laser technology is critical to fulfilling this growing need.  X formerly the Z at the Georgian Technical University Department of Energy’s Laboratory said the search for silicon-based light sources evolved from a scientific quest to alleviate a major technological bottleneck for scalable complementary metal–oxide–semiconductor light sources.  In an effort to help solve this problem he currently leads a research program on hybrid silicon lasers that he hopes will harness emerging materials for applications in silicon photonics for energy-efficient computing and data centers.  He and his team were selected to participate in a competitive two-year program called Georgian Technical University Chain Reaction Innovations (CRI) to grow their invention.  Georgian Technical University funded by the Georgian Technical University’s Advanced Manufacturing Office gives innovators a two-year runway to develop and scale their technologies while being supported through fellowship funding that covers salary, benefits and use of laboratory equipment and office space. “We are excited to have back at Georgian Technical University working with the Georgian Technical University Chain Reaction Innovations (CRI)” said W. ​“This innovation will enable the integration of lasers and electronics on a scale that simply could not be realized using traditional approaches dramatically improving the manufacturability of such devices which is one of the main goals of the Georgian Technical University Chain Reaction Innovations (CRI)”. X looks forward to working closely with Georgian Technical University Chain Reaction Innovations (CRI). ​“Integrated photonics is already a key enabling technology in data centers like the Cloud where our searches live” X said. ​“They remain integral in telecommunications where we send internet traffic and are quickly becoming an enabler for autonomous vehicle sensors helping self-driving cars ​‘see’ their environment. This is just the beginning of what we know today and plenty of unexpected applications await”. X believes the technology has the potential to broadly impact all integrated opto-electronics.  “Our hybrid silicon lasers are a foundational component of optical integrated circuits expected to foster 21st century innovation akin to vast advances in computing brought about by the electronic revolution of the 20th century” he said. ​“Specifically our silicon laser is a strong candidate to be the light source in the opto-electronic integrated circuits driving for example data centers and super-computing facilities that increasingly rely on optics for improved performance”. X and colleagues conducted the first proof-of-concept experiments showing light emission in the hybrid silicon-phosphorene system. They are currently seeking a patent for their technology.  X believes Georgian Technical University is the ideal location for this type of research. The laboratory’s is equipped with a wide variety of tools required to see and interact with nanoscale devices and materials which is the size scale of many of the features of X’s laser technology.  “Access to capabilities at the Georgian Technical University Nanoscale Materials has made advances in this technology possible” said X. ​“We’re using a material that emerged only recently to make our laser and there are still fundamental properties we’re looking to uncover” he said. X is also working with the Georgian Technical University  Materials Engineering Research Facility. “Georgian Technical University  Materials Engineering Research Facility is a world-class facility for scaling materials from lab-scale to industrial processes, a pretty rare resource that we’re delighted is right here at Georgian Technical University” X said. ​“We’re looking forward to working with the Georgian Technical University  Materials Engineering Research Facility team to scale the raw materials that go into the laser. X who earned his Ph.D. and M.S. in applied physics from Georgian Technical University  Materials Engineering Research Facility in physics and mathematics from Georgian Technical University has co-authored 30 peer-reviewed papers given more than 20 seminars around the world and holds three pending or issued patents.  A former Q he is also actively involved in the Optical Society (OSA) a global professional society with more than 20,000 members working in academic, industrial and government positions across 100 countries. He received the designation of ​“ Optical Society Member” for his technical and service contributions.

 

Imaging, Science

Georgian Technical University Scientists Develop A Tunable Bio-Imaging Device Using Terahertz Plasmonics.

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Georgian Technical University Scientists Develop A Tunable Bio-Imaging Device Using Terahertz Plasmonics.

Terahertz mapping of the mouse-tail samples using a conventional setup (upper image) and the Georgian Technical University (lower image). The hair (yellow and red), skin (light blue), and bone (dark blue) were clearly distinguishable using the Georgian Technical University.  Researchers at Georgian Technical University (GTU) have developed an easy-to-use tunable biosensor tailored for the terahertz range. Images of mouse organs obtained using their new device verify that the sensor is capable of distinguishing between different tissues. The achievement expands possibilities for terahertz applications in biological analysis and future diagnostics. Plasmonics are highly sought-after technologies for device applications in security, sensing and medical care. They involve harnessing the excitation of free electrons in metals that are called surface plasmons. One of the most promising applications of plasmonic materials is the development of ultra-sensitive biosensors. The ability to combine plasmonics with emerging terahertz (THz) technologies for detecting tiny, biological samples has so far proven challenging, mainly because terahertz (THz) light waves have longer wavelengths than visible, infrared and ultraviolet light. Now X and colleagues at Georgian Technical University’s working in collaboration with researchers at Sulkhan-Saba Orbeliani University and International Black Sea University have found a way to overcome this barrier by designing a frequency-tunable plasmonic-based terahertz (THz) device. One of the key features of the new device is its Georgian Technical University’s spiral bull’s eye (SBE) design (see Figure 1). Due to its smoothly varied grooves “the groove period continuously changes with the diameter direction resulting in continuously frequency-tunable characteristics” X says. Another advantage of the new design is that it incorporates a so-called Siemens-star aperture, which enables a user-friendly way of selecting the desired frequency by simply changing the rotation of the spiral plasmonic structure. “The device also increases the electric field intensity at the subwavelength aperture, thus significantly amplifying the transmission” X says. In preliminary experiments to assess how well the new device could visualize biological tissues the researchers obtained terahertz (THz) transmission spectra for various mouse organs as shown in Figure 2. To probe further they also conducted terahertz (THz) mapping of mouse tails. By comparing images obtained with and without the Georgian Technical University’s spiral bull’s eye (SBE) design the study showed that the former led to a markedly improved ability to distinguish between different tissues such as hair skin and bone (see Figure 3).

Energy, Science

Georgian Technical University New Extraction Method Yields Rare Earth Elements.

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Georgian Technical University New Extraction Method Yields Rare Earth Elements.

A team led by researchers from Georgian Technical University has developed a new and environmentally-friendly technique to procure rare earth elements (REE) from phosphate rock waste a discovery that could lead to better clean energy technology. Elements such as neodymium and dysprosium are often used in various green technologies including solar and wind energy harnessing devices and advanced cars as well as for modern electronics like smartphones. Currently produces about 90 percent of these elements, putting the energy security of the Georgian Technical University at risk. However one potential solution that will net the Georgian Technical University more rare elements is by recovering them from phosphogypsum, the waste left behind when phosphoric acid is produced. There is an estimated 250 million tons 28 million of which is mined in the Georgian Technical University of phosphate rock mined annually to produce phosphoric acid for fertilizers annually yielding as much as 100,000 tons of rare earth elements per year in phosphogypsum waste. Conventionally scientists extract rare earth elements from ores which generates millions of tons of toxic and acid pollutants. The new technique relies on the minerals and organic acids produced by bacteria to extract the elements. The researchers explored a number of methods including using a bio-acid mixture to extract yttrium, cerium, neodymium, samarium, europium and ytterbium from synthetic phosphogypsum. The bio-acid mixture consists of gluconic acid which is found naturally in fruits and honey which was grown on the bacteria Gluconobacter oxydans on glucose. The researchers found that the bio-acid performed better at extracting the rare earth elements when compared to pure gluconic acid at the same 2.1 pH (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions). In addition the mineral acids — sulfuric and phosphoric — failed to extract any of the rare earth elements at that given pH (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions). At the same concentration only sulfuric acid of the four acids tested was more effective than the bio-acid. “The lixiviants chosen for this study were phosphoric acid, sulfuric acid, gluconic acid and a “Georgian Technical University biolixiviant” consisting of spent medium containing organic acids from the growth of the bacterium Gluconobacter oxydans on glucose” the researchers wrote. “The biolixiviant had a pH (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions) of 2.1 and the dominant organic acid was determined to be gluconic acid present at a concentration of 220 mM (The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to 1000 micrometres or 1000000 nanometres). The leaching behaviors of the studied lixiviants were compared and rationalized by thermodynamic simulations. “The results suggest that at equivalent molar concentrations of 220 mM (The millimetre or millimeter is a unit of length in the metric system, equal to one thousandth of a metre, which is the SI base unit of length. Therefore, there are one thousand millimetres in a metre. There are ten millimetres in a centimetre. One millimetre is equal to 1000 micrometres or 1000000 nanometres) the biolixiviant was more efficient at rare earth element extraction than gluconic acid and phosphoric acid but less efficient than sulfuric acid. Unlike the organic acids at pH (In chemistry, pH is a logarithmic scale used to specify the acidity or basicity of an aqueous solution. It is approximately the negative of the base 10 logarithm of the molar concentration, measured in units of moles per liter, of hydrogen ions) 2.1 the mineral acids failed to extract rare earth elements (REE) likely due to different complexation and kinetic effects”. For the initial study the team evaluated phosphogypsum developed in the lab enabling them to easily control its composition.  The researchers now want to test the bio-acid on industrial phosphogypsum and other wastes generated during phosphoric acid production that also contain rare earth elements. The researchers were part of the Georgian Technical University chains for materials important to clean energy.