Zaqaria Buachidze

The vapor growth of ZnO microcrystals was studied using the Scanning Electron Microscopy and Energy Dispersive Spectroscopy. The microcrystals were grown by annealing ZnO, CuO and ammonium chloride powders. As a result, the ZnCl2, ZnO and CuCl vapor was formed and condensed on Si substrate, which was gradually heated up to 350oC. It was established that the growth proceeded in two stages. Beginning from 240oC, the CuCl-ZnCl2 eutectic droplet with a low melting point was formed. With time, the droplet was oversaturated with ZnO, and ZnO's solid nuclei were precipitating from it. They served as seeds for the formation of hexagonal ZnO microrods, which were growing along the c-axis ([0001] direction) by the slow, thermodynamically driven Vapor–Solid mechanism. As a result, the rod-like ZnO microstructures were produced on Si substrate. The second stage of growth started when the substrate temperature reached 300oC. At this temperature, the secondary nucleation took place on the prism surfaces of ZnO microrods, causing brunched structures. The ZnO brunches were growing again along the c-axes, forming elongated 1D type microcrystals. In contrast to the slow growth of primer ZnO microrods, at elevated temperatures the ZnO brunches were growing significantly faster. This kinetically driven process caused the vanishing of the fast growing (0001) plains, resulting in the tapering of ZnO microcrystal tips.

In April 2020 the researchers of the Institute for problems of Engineering Physics of the Georgian Technical University started a project on developing the high-grade active personal protective equipment based on HEPA filters with impregnated nanoparticles of zinc and copper oxides, which not only filtered the air, but also deactivated viruses that entered the filter. Presently it was found that in fact the infectious virus is mainly airborne, and people can be infected when they inhale aerosols produced by other persons who are at a considerable distance. Hence, reducing transmission of SARS-CoV-2 requires measures to avoid inhalation of in-fectious aerosols, including ventilation, air filtration and disinfection, and higher-grade protection for health-care staff and front-line workers. Port-able HEPA purifiers were recognized as  the most suitable remedy for eliminating airborne SARS-CoV-2 from indoor environments. The presented research reports microwave enhanced synthesis of quasi-spherical CuO nanoparticles [4] and ZnO nano-sized tetrapods, the ultrasound enhanced impregnation and acute toxicity testing of the synthesized na-noparticles to white rats and bird embryos and the preliminary testing of the antibacterial and antiviral efficacy of the developed filters.

Proton therapy is widely used in more than 110 medical centers around the world. The localized combined therapy using radiotherapy, mild hyperthermia, chemotherapy, photodynamic therapy ROS therapy a prospective tool to increase the biological effectiveness and safety of can-cer therapy while the most advanced kind of the hyperthermia is the Curie temperature controlled localized hyperthermia (CTCLH) A principally new approach is the usage of  the isotopic enriched 10B and 11B containing na-nomaterials (both in the form of pure boron and boron nitride) nanopar-ticles and boron-neutron and boron-proton capture nuclear reaction products Novel microwave enhanced methods of synthesis magnetic metal nanoparticles, isotopic enriched hexagonal boron nitride (hBN) nanosheets and boron nitride encapsulated magnetic metal nanoparticles for the (CTCLH) and localized boron-neutron and boron-proton capture therapy were developed and their magnetic properties were tested. A novel ovoscopy method of testing the acute toxicity of the synthesized nanomaterials to avian embryos excluding the use of mammals and other living animals for drug testing was examined

Use of nano-materials as synergistic components of pesticides can provide a novel approach for coming closer to a more sustainable balance between the sharp increase in agricultural production and conservation of nature, although they can pose a considerable threat to environment. The presented study reports the results of laboratory and field testing of the insecticidal combinations containing pyrethroid, syn-thetic substances, essential oils, mineral), a 100% biodegradable emulsi-fier, hydroxyethylcelluslose (HEC) and environmentally compatible sol-vents. The laboratory tests, field trials and acute toxicity testing on white rats clearly showed that all the tested combinations are characterized with the high synergy of components, sharply increased biological effec-tiveness of synergystic and reduced acute toxicity in comparison with the widely used highly effective insecticidal pyrethroid/organophodphorus combination “Prostore 420 EC”. The biological effectivity, synergy rate of the alumina nano-powder based combinations were for about 12-15 % higher than of the diatomite and kaolin based micro-powers, while the environmental safety was within the experimental accuracy of testing.

It has been previously shown, that that the Ni-Cu nanoparticles synthsized at lower than usual temperatures using microwave enhanced synthesizes and annealing can be successfully used for local hyperthermia revealing high magnetic properties. Mixtures of Nanoparticles with liquid crystals can play an important role as effective and non-toxic material for modalities of the Curie point controlled strongly localized magnetic hyperthermia with a precisely tuned prolonged release of nanoparticles into tissue cells. It has also been shown that coating, encapsulating or modifying of nanoparticle surface can help to overcome the problems related to corrosion and agglomeration in a medium and strong magnetic field and reduce the acute toxicity of combinations to white rats tested using a long-term monitoring of their behavioral characteristics and physiological parameters. However, taking into account the growing restrictions on the use of laboratory animals and enhancing of measures for providing increased safety of use of manufactured nanoparticles, new methods of testing of acute toxicity should be developed and applied. The reported research deals with deals with preparation of mixtures of liquid crystal compositions with uncoated, coated, surface modified, phosphatized and encapsulated nanoparticles and testing their acute toxicity to chick embryos using visible light ovoscopy. Experiments showed that the acute toxicity of  the mixtures is maximally reduced through encapsulating in boron nitride. Additional experiments using behavioral monitoring of exposed white rats and chick embryos is necessary to assess the correlation between the results achieved using these two different methods of toxicity testing. 

A vast amount of nanoparticles has been developed and proposed for the local hyperthermia of cancer during the last decades, but only a few of them correspond to the mandatory requirements of having therapeutic range Curie temperature (T_C= 41-45⁰C), high-rate crystallinity and “strong” magnetic properties, strictly controlled homogeneity and dispersion of the nanoparticles, good biocompatibility and harmless decomposition products. Among them are the nickel-copper (Ni-Cu) and silver doped lanthanum manganite (AgxLa1-xMnO3) nanoparticles. The developed research showed that the materials obtained at lower than usual temperatures using microwave enhanced synthesizes and annealing can be successfully used for local hyperthermia revealing high magnetic properties. Mixtures of Nanoparticles with liquid crystals can play an important role as effective and non-toxic material for modalities of the Curie point controlled strongly localized magnetic hyperthermia with a precisely tunned prolonged release of nanoparticles into tissue cells.Therefore, the preparation of mixtures of liquid crystals with a transition temperature from the nematic to the dispersed phase in the range of 41-45⁰C, and their comprehensive study is an important practical task. This problem is complicated by the fact that the transition temperature to the dispersed phase depends essentially on the concentration of nanoparticles in the mixture. The reported research deals with preparation of mixtures of Ni-Cu and AgxLa1-xMnO3 nanoparticles and compositions of 12 commercially available liquid crystals.

The formation of crystalline nitride materials is a complicated task, which usually needs

the high temperature processes and the application of active nitriding precursors. Previously,

we have developed the hydrazine-based technology for producing such nitride nanomaterials as

germanium and indium nitrides. The purpose of this work was to further improve this

technology by adding the ammonium chloride (NH4Cl) to hydrazine (N2H4), and to investigate

the formation of Ge and boron nitrides using this technology.

The germanium nitride was chosen as a model material, because its formation in a poor

hydrazine was studied in details, allowing for the comparative study of differences between the

hydrazine-assisted and hydrazine+ammonium chloride-based processes. The interest for the

growth of BN nanomaterials was caused by its unique physical properties and the ability of hBN to form the layered 2D nanostructures.

The grown nanomaterials were characterized by scanning electron microscope (SEM),

X-ray diffraction (XRD), energy dispersive spectroscopy (EDS).

The analysis of thermochemical reactions that involved the precursor existing in the

reactor revealed that in the case of Ge and B sources the reactions that lead to the formation of

Ge3N4 and BN are thermodynamically most favorable.

The nanostructures containing BN layers were synthesized on Si substrate during 20

hours at 700°C. They were also subjected to Rapid Thermal Annealing. The formation of h-BN

was confirmed by XRD and EDS analysis. The thickness of BN layers was well below 100 nm.

As for germanium nitride, the α-Ge3N4 nanowires were synthesized on Ge substrate at 440 °C.

This synthetic temperature is by 60 and 410 °C lower than the growth temperature of the same

material using hydrazine or ammonia.

The obtained results clearly demonstrated that in the vapor of a mixture of NH4Cl+ N2H4

the active nitriding precursors are formed, which enable the low temperature growth of nitride

nanomaterials. 

Among the pressing problems of our time, a special place belongs to the problem of “combating” cancer. Disappointing is the fact that cancer is growing all over the world. Today, powerful cancer control methods are applied, such as surgical treatment, chemotherapy and radiation therapy (radiotherapy). The latter two methods are characterized by high efficiency, but are aggressive with a number of side effects that negatively affect the normal functioning of the body, and the quality of life in general. Use of Hyperthermia as a treatment modality has been significantly increased in duration of last decades, especially in cancer clinics.. Hyperthermia is almost always used with other forms of cancer therapy, such as radiation therapy and chemotherapy. Hyper-thermal exposure can make some cancer cells more sensitive to radiation or harm other cancer cells that radiation cannot damage. Hyperthermia can also enhance the effects of certain anticancer drugs, which is mutually strengthening and makes healing more likely–the so-called synergistic effect of hyperthermia. It was revealed that cytostatic drugs (chemotherapy substances) clearly act more aggressively at temperatures over 40 C than within the range of normal body temperature. By many researchers Hyperthermia is considered as one of the promising methods of preventing and treating cancer. However, when the body is under thermal impact of different level and duration, this definitely will lead to appropriate metabolic and functional changes not just in tumor tissue, but in normal one also. That is why, low toxic magnetic nanoparticles with regulated Curie temperature in the so called therapeuthic range is of great importance. This report gives a detailed description of the high capacity microwave enhanced synthesis of the Carbon coated Ag doped lanthanum manganite nanocomposites for magnetic hyperthermia and its main physical cgarachteristics

The InP based nanowires were produced by direct annealing of crystalline InP sources in hydrazine (N_2H_4) vapor and subsequent condensation of volatile spices onto the substrates. The morphology and sizes of nanowires showed strong dependence on the growth temperature. In the temperature range of 440 – 540 °C the morphology of InP nanostructures were changed from true nanowires with minimum diameters of ca. 25 nm formed at 440 °C, to faceted, several micrometer size large crystalline blocks of InP growing at 540 °C simultaneously with the rhombus decorated zigzag shaped InP nanowires with extended surfaces. The nanowires growth mechanism also varied with the temperature. In the range of 440 – 500 °C they were growing through the Vapor–Solid mechanism. At 540 °C the Vapor–Solid and Vapor–Liquid–Solid mechanisms coexisted forming large elongated blocks of indium phosphide together with zigzag shaped InP nanowires.

As is known, modern steel and non’ferrousmetallurgy would be impossible without a variety of manganeseand copperbearing doping and master alloys. Along with the depletion of deposits of high-grade manganese ore and its corresponding rise in price, the development and application of methods for processing low-grade ores and tailings of high-grade ores, as well as new methods for obtaining new reducing and doping alloys and master alloys containing manganese are becoming increasingly important.A master alloy is a combination of base metals such as copper, aluminum, manganese or nickel, and one or two other elements of relatively higher percentage. They are designed to improve metallurgy processes by refining the final properties of different metals. Master alloys are chiefly used in the metal industry. The two main applications are composition adjustment and structure control. These alloys are preferred over pure metals as they are more economical, and save production time and energy as they melt faster in lower temperatures. Copper-manganese master alloy has the features of manganese and copper, which is a soft, conductive, non-ferrous metal. Georgia has a big amounted manganese and copper bearing wastes and low grade ores which makes the local production of copper-manganese master alloys especially relevant. This report gives a detailed description of the innovative processing methods developed in the Ferdinand Tavadze Institute of Metallurgy and Materials Science, Georgian Technical University, as well as the characteristics of the obtained materials

Approximately 125-130 thousand tons of toxic arsenic bearing waste materials are disposed in Racha-Lower Svaneti districts of Georgia. This poorly managed or abandoned waste contains about 7.5-8 thousand tons of arsenic. Due to the partially destroyed non-sarcophagi, dams, sedimentation tanks and other protective structures freely permeable to water arsenic freely spreads freely with storm and river flows throughout the region and causes persistent and growing pollution of river bottom sediments and soils. Given that the soils of this region of Georgia are very rich in arsenic, such pollution poses a serious danger to the population and wildlife of this mountainous region of the country. Soil pollution mainly occurs by the transfer of waste along the flow along the gorges of the rivers Tslhenistskali, Lukhuni and Rioni for tens of kilometers along and up to ten kilometers across the flow, that is, in the months of concentration of the local population and agricultural production. The main aim of the study was thr development of the detailed maps showing the main directions of pollution spread, to determine the dynamics of contamination growth and elaborate a preliminary list of preventive measures urgently needed to mitigate the pollution of soils and food which causes a high-level morbidity prevalence in the region.

Georgia could serve as a unique natural testing ground for the development of green industry using advanced technologies for industrial processing of hazardous waste. The goal of the reported work was to improve on the current methods of reprocessing waste by using a combination of a microwave enhanced method of processing used tyres and plastic residues with the microwave enhanced processing of manganese bearing waste and low-grade ores into manganese oxide concentrate. The manganese concentrate could be processed into high-grade manganese alloys (metallic manganese, low-carbon ferromanganese, and composite manganese alloys). Microwave heating required lower energy and resulted in a two-fold increase in yield

Managers of and researchers several levels urgently need indicators for target setting, performance assessment, monitoring, management and decision-making purposes. The choice of the most suitable indicator framework is crucial, but difficult, as it requires expert knowledge. To help them in their choice, this report compares seven recently published indicator standards for Smart sustainablesystems. A taxonomy was developed to evaluate each of their 413 indicators against five conceptual urban focuses (types of urban sustainability and smartness), ten sectoral application domains (energy, transport, ICT, economy, etc.) and five indicator types (input, process, output, outcome, impact). The results clearly discriminate between indicator standards suited for evaluating the implementation of predominantly smart city approaches versus standards more focused on sustainability assessment. A further distinction is possible in standards almost fully oriented towards impacts reached, and standards that allow for progress evaluation according to steps in the implementation process. Some standards provide a narrow focus on output indicators evaluating the progress in implementing smart urban ICT solutions (e.g. number of smart meters installed). Managers are encouraged to complement such evaluations with impact indicators that demonstrate the effects of those solutions. This report provides guidance for city managers and policy makers to select the indicators and standard that best correspond to their assessment need and goals, and align with their stage in Smart sustainable city implementation.This report gives the principles for simple and rapid calculation of the SDI (Sustainable Development Index) and the K-index (Knowledge Society Index) and analyses their correlation to characterize the accuracy and reliability of both indicators.

The most serious ecological problem is the accumulation of 130 thousand tons of toxic arsenic waste accumulated in the industrial region of Racha and KvemoSvaneti, to which was added over the years hundreds of tons of arsenic-containing waste imported from Russia. Due to their good bioaccumulation ability, arsenic residue accumulates in seabed sediments and soils, which gradually causes changes in soil geochemical soil composition and composition as a result of environmental conditions.Therefore, it is important to determine the direction of pollutant sources of arsenic industrial arsenic and the spread of arsenic industrial waste. The aim and purpose of the scientific research of the monograph is to determine the content of arsenic in the soil of Racha and Kvemo Svaneti industrial region, water of Lukhuni and Tskhenistskali rivers and water sediments, to study their ecochemical condition and to take environmental preventive measures.The spread of arsenic waste pollution is mainly related to the leakage of sarcophagi, storage facilities, treatment plants, and the precipitation of wastewater dumped in the open air on the premises of industrial facilities and the discharge of toxic effluents into the water and the release of toxic substances. Naturally, the valleys of the river Tskhenistskli, Lukhuni and Rioni are mostly polluted, along which the spread of anthropogenic pollution is tens of kilometers long, and a few kilometers - in the direction of the valley.The Rioni River and Tskhenistskali are one of the main sources of drinking water in western Georgia, as well as they are intensively used for cultivating agricultural lands and for industrial purposes. Protecting the quality of Rioni and Tskhenistskali waters is a topical environmental problem.

Despite the fact that the Racha Mining and Processing Plant ceased to function in the nineties of the last century, in the village. The arsenic content in the soil of Uravi and its environs is significantly higher than the maximum allowable concentration and upper limit of phytotoxicity (2-7 mg / kg and 15-30 mg / kg). Studies have shown a particularly high incidence of ischemic heart disease and arterial hypertension. Which was confirmed by large-scale repeated studies. A detailed analysis of the epidemiological study material revealed that the situation was particularly dire for the population of the region contaminated with arsenic industrial waste. Excess arsenic content in soil, drinking and irrigation waters is especially dangerous for human health. Exposure to arsenic causes many skin diseases such as melanoma, keratosis, as well as oncological diseases of the gallbladder, kidneys, lungs, vascular damage of the lower extremities (legs), diabetes, hypertension, infertility and mental retardation in children. Signs of arsenic poisoning and the diseases caused by it usually appear after a long period (5-20 years). Because some of the effects of arsenic are irreversible (untreatable), the only way to combat them is to take preventative measures to mitigate the harmful effects of arsenic on the human body. This report gives a dateyled description of the the data of soil and food contamination and the correlation of contamination and the results of the case’control epidemiological studies

Millions of thousands tons of manganese ore enrichment waste containing about from 5 to 20 % manganese are disposed in Ggurghumela landfill and hundreds of thousands tons of manganese bearing waste are added to Ghurghumela and other landfills or directly spilled to Khvirila river and groundwater in Chiatura municipality of western Georgia. According to our estimation based on the official dsata the proportion of damage caused to nature as a result of economic activities in the municipality of Chiatura, in relation to the whole of Georgia, has been approaching 50 percent in recent years and is steadily growing. Our estimates show that in the coming years it may rise to a value of 70%. The main causes of enormously high damage to the water quality and the environment in whole are the uncontrolled mining in open deposits and spills of the used and untreated water to river Khvirila from the mining and enrichment facilities and poorly monitored and managed (or totally abandoned) landfills. The only way to mitigate the enormous contamination of water and the environment in whole is to enhance the restrictions for the open mining, improve the monitoring and control of enrichment facilities and start the industrial processing of the disposed waste.This report gives a detailed assessment of the sources of the environment contamination with manganese and a brief characterization of the environment friendly technologies developed in the Georgian Technical University. 

Tis report mainly deals with the experiences in CBRN Experts redirection to non-prohibited activities conducted under the STCU Non-Proliferation and Conversion Program over a period of 17 years in Georgia.It analyzes the various opportunities to learn of experiences and challenges in the same fields from other countries and regions. It also discusses what effective practices could be of interest for activities to prevent the non-state actors from gaining access to nuclear, chemical and biological weapons and their means of delivery. The need to impede access to sensitive weapons technology, materiel, and expertise by proliferant states and terrorist networks worldwide is an objective of the current U.S. National Security Strategy, National Strategy to Combat Weapons of Mass Destruction, and National Strategy for Combating Terrorism. The growing global threat to national security globally from available WMD-relevant expertise prompts the international siciety to broaden to countries of the Former Soviet Union, especially to Russian Federation, Ukraine, Georgia and Armenia, which have a considerable experience in technologieas concerning CBRN research and technologies. Several approaches and local programs are proposed to provide steady, effective, and cost-efficient platforms for the regional and global nonproliferation/threat reduction programs

The article discusses issues of the use of the electromagnetic field to solve the tasks of controlling different types of dynamic objects. These include: Periodically changing three-positional information contactless control indicator; Wide-range controllable large DC power supply; Three-coordinate interinductive measuring converter; Control system for constructing adjustable synchronous collector-free electric generator; Compatible and adjustable multi-channel receiver-transfer antenna.

More than hundred thousand tons of highly-hazardous arsenic bearing waste is disposed on poorly managed landfills in the highland of Georgia, causing a significant morbidity prevalence in children and adults, including cancer and mental disorders. The measures taken by the Georgian Government and a number of international organizations aimed to renovation and reconstruction of the sarcophagi, waste sumps and abandoned landfills cannot solve the problem due the extremely high arsenic contamination of soils, which, in turn, leads to pollution of food causing morbidity of population. The only realistic approach of solving the problem is the phytoremediation of soils which can last many decades without selecting and propagating of plants providing a high uptake of arsenic. The report deals with the criteria for selection of and propagation of plants, includingperennial conifers and agricultural crops, which can be processed to alcohol, fuel and biomass for gas production. Intensive and extensive phytoremediation should be accompanied by physical, chemical and biological recycling and remediation of the dumped and landfilled arsenic bearing waste.

Doctoral Thesis Referee

Master Theses Supervisor

Doctoral Thesis Supervisor/Co-supervisor

Scientific editor of monographs in foreign languages

Scientific editor of a monograph in Georgian

Editor-in-Chief of a peer-reviewed or professional journal / proceedings

Review of a scientific professional journal / proceedings

Member of the editorial board of a peer-reviewed scientific or professional journal / proceedings

Participation in a project / grant funded by an international organization

Participation in a project / grant funded from the state budget

Patent authorship

Membership of the Georgian National Academy of Science or Georgian Academy of Agricultural Sciences

Membership of an international professional organization

Membership of the Conference Organizing / Program Committee

National Award / Sectoral Award, Order, Medal, etc.

Honorary title

Monograph

Handbook

Research articles in high impact factor and local Scientific Journals

Publication in Scientific Conference Proceedings Indexed in Web of Science and Scopus