6TH INTL. SYMP. ON NEW AND ADVANCED MATERIALS AND TECHNOLOGIES FOR ENERGY, ENVIRONMENT AND SUSTAINABLE DEVELOPMENT

The oxygen demand for medical and industrial needs grows over 6% annually from 2015, and it is estimated that the oxygen market will grow from $27.7 billion in 2019 to even $ 36.5 billion in 2030 [1]. According to The Business Research Company, this growth will be also driven by COVID-19 and the medical needs it imposes [1].

Today, most of the oxygen produced for large-scale industry needs is obtained by cryogenic distillation, which due to the high energy consumption of the liquefaction of gases from the air, is an expensive method [2]. A promising alternative to the cryogenic oxygen production technology is air separation by temperature-swing adsorption (TSA) where so-called oxygen storage materials (OSM) are used. OSMs can reversibly exchange a significant amount of oxygen between their structure and atmosphere.

In the last 2 decades, renewed interest in RMnO_3+δ oxides appeared, in terms of their application as OSMs. Their main advantage (contrary to other groups of OSMs, [3]) is the ability to work in the temperature-swing mode at temperatures as low as 200-300 °C, which is promising from both, economical and construction points of view. However, until now most of those materials operated effectively only in pure O₂ atmosphere, which is not applicable for oxygen production.

A significant breakthrough has come with the results of the recent research, as it was possible to design RMnO_3+δ materials able to operate in air practically as effectively as in O₂ atmosphere [4]. Also, some general rules were established in terms of designing such air-operating OSMs, like dependence of oxygen storage capacity (OSC) on ionic radius of R.

Nd-substituted Y_1-xNd_xMnO_3+δ materials described in this work were synthesized via sol-gel auto-combustion method followed by several variations of annealing at elevated temperatures in different atmospheres. Crystal structure and phase composition of prepared powders were examined by means of X-ray diffractometry (XRD). Oxygen storage performance was evaluated using thermogravimetry. Structure and composition of oxidized samples were also investigated by XRD. Morphology of powders was examined by scanning electron microscopy.

It was established that proper modification of the preparation route of the Nd-substituted Y_1-xNd_xMnO_3+δ can increase the OSC more than twice and greatly improve the rate of redox reactions. The laboratory-scale apparatus for oxygen separation from air via TSA was designed and constructed. Equipment was tested using the YMnO3+δ-based materials developed in this work.

The developed lightweight dodecaboride - and boron carbide-based ceramic composites hold great potential for a wide range of applications in extreme conditions: personal protection or for armored defense of ground military equipment and vehicles for the manufacture of abrasive nozzles, friction pairs for pumping oil and other aggressive liquids, constructional ceramics for nuclear power plants, etc. The correlations between structures and mechanical characteristics of alpha-AlB¹²-, AlB₁₂C2-, B₄C-based lightweight ceramics and composites synthesized or sintered by hot pressing (at 30 MPa). The effect of C, TiC and SiC additions on the properties of the resultant composites and the particularities of the ceramics destruction under shock loading are discussed. Computer modeling of the influence of construction parameters of ceramic-composite barrier on ballistic steel rod of the B-32 armor-piercing bullet (hardness HRC = 67 and 5,32 g weight of the steel core) into a two-layer ceramic-composite barrier was performed. Ballistic tests performed on 10 mm thick plates fabricated from the developed ceramics showed that the materials could withstand shot using a bullet with initial kinetic energy of 3.7 kJ.

The golden mussel (Limnoperna fortunei) is a species of bivalve mollusc introduced in Brazil via ballast water in the 1990s. Given the biological and ecological characteristics of the species, as well as the favorable environment in the country for its proliferation, the golden mussel has become an exotic invasive species that has caused several problems in the aquatic environment because of its ability to form colonies in structures. The species adheres on the surfaces by protein filaments, causing serious environmental, social and economic damages, provoking structural and functional alterations in the ecosystems and damages to the human activities.
The challenge presented consists of biological fouling combat through treating underwater surfaces with freshwater natural products, in particular those from red algae. Fouling control tends to arouse the interest of shipbuilders, marine vessel operators, fish farming in tanks and hydroelectric power plants. In Brazil, the chemical treatment against the incrustation of the golden mussel, for example, made only in three hydroelectric power plants in Minas Gerais, has annual cost of R$ 1,494,000.00 [1].
With the worldwide ban of TBT-based antifouling paints since 2008, alternative, environmentally safe treatments gain more appeal, considering the risk associated with the alternative products currently in use. Natural marine products have since been recognized as a promising alternative for the replacement of commercially used antifouling until the moment [2].
A selection of natural seaweed products with antifouling activity may provide effective results with little or no environmental impact compared to currently used products [3], while contributing to the understanding of ecological functions and mechanisms of metabolic production secondary. At least 18 different regulatory biocides are currently being used as an alternative to tributyltin free antifouling paints, but these also pose some threat to the aquatic environment. In fact, even biocide-free antifouling paints are toxic to marine organisms over a broad spectrum [4]. For this reason there is still an urgent demand for new low-impact anti-fouling products.
This article aims to disseminate this broad line of research and consolidate information about the potential of marine organisms as producers of secondary metabolites (natural products) with antifouling activity, in the light of scientific production.
Key words: Golden Mussel; red algae; anti-fouling products; secondary metabolites; tributyltin.

Solid electrolytes are generating considerable interest for solid-state batteries to address safety and performance issues. It is clear that a complete understanding of such materials requires greater fundamental knowledge of their underlying ion transport and interfacial properties. In particular, grain boundary effects on ion transport are not fully understood at the atomic scale. This presentation will highlight recent studies in this area, including the influence of grain boundaries on Li-ion transport in the Li-rich anti-perovskite Li3OCl and the different effects of grain boundaries in a sulphide (Na3PS4) solid electrolyte compared to an oxide (Na3PO4) solid electrolyte. A combination of advanced materials modelling techniques has been utilised to gain new insights into these complex materials, which are valuable in developing strategies to optimise their electrolyte properties.

The MATUROLIFE project aims to couple design with advanced material innovation to produce smart furniture, clothing and footwear with assistive functionality. MATUROLIFE products will provide older adults with assistance in their day to day lives to help them remain independent for longer. With an ageing population, there is a need for assistive technology that is acceptable to the user, it should be desirable and discreet. MATUROLIFE aims to achieve this through use of smart textiles. To make textiles smart and enable them to perform an assistive function, they require the integration of electronic components such as sensors. Rather than have such sensors as separate wearable devices, MATUROLIFE aims to integrate them into textiles for application in the design of clothing, footwear and furniture.

The project combines expertise from the creative industries and manufacturing with cutting-edge advances in electrochemistry and nanotechnology. Highly innovative, conductive, multifunctional smart textiles will be developed, as well as a collection of assistive products. The collaboration will enable competitive and sustainable development of the partners involved.
The project has seen significant advancements in terms of both design and scientific development. The materials team have been considering methods for introducing electronic connectivity to a textile, in particular an additive process to coat the fibers within the textile with a thin layer of copper.
There has also been extensive involvement of older adults in the design process through interviews and co-creation workshops in the 9 partner countries. Co-creation activity has involved partners working with older people to develop smart and assistive clothing, footwear and furniture concepts that build on scientific developments whilst being desirable and simple to understand and use.
Building on this co-creation approach, the teams are combining their skills and expertise to progress the most promising emerging technologies, and develop prototypes which will be tested and refined in the coming months.
The project has already been recently awarded in Boston by the Design Management Institute with a Design Value Award for 2019.

A highly efficient black TiO₂ photocatalysts for wastewater treatment were prepared. The synthesis of promising black TiO₂ has been focused on optimizing different reductant photocatalytic materials, active under both UV and visible light illumination was synthesized by sol-gel method followed by the chemical reduction of pristine white TiO₂. Pristine titanium oxide nanoparticles have been synthesized using the sol-gel method from precursors of titanium isopropoxide, ethanol and nitric acid following by annealing at different temperatures between 400 and 800°C, in air and argon atmospheres. At high temperature, larger particles grow at the smaller particles leading to more nucleation of the nano-clusters and more growth centres. Heat treatment in the synthesis process affects anatase-rutile ratio, crystalline nature of the particles, morphology, and porosity. Colour change of pristine TiO₂ powder has been monitored under chemical reduction targeting a higher photocatalytic activity for pesticides, phenolic compounds and drugs degradation under UV and solar irradiation. The narrower bandgap of black TiO₂ extends the photoresponse to the visible light region. The black titanium oxide nanoparticles show excellent visible-light photocatalytic activity for pollutants degradation.

Carbonaceous materials are considered as one of the most effective adsorbents for pollutant removal and wastewater treatment. Due to their high surface area and distinct chemical and physical properties of the carbonaceous materials, these are emerging as one of the most effective adsorbents. Carbonaceous materials have a large number of applications, mainly in environmental protection (eg, adsorption of volatile organic compounds (VOCs) and CO2 as well as purification of wastewater by removing heavy metal ions or phenols, chemical industry and electrochemistry [1]. These materials can be obtained by the pyrolysis process.
Pyrolysis represents a thermal decomposition process conducted in an inert atmosphere. Through this process, a large variety of useful materials can be obtained, ranging from fuels (char, oils, syngas) to functional materials with a wide dimension pallet (micro to nanoscale). As raw materials for pyrolysis, secondary raw materials can be used, such as polymeric wastes, making this process a useful one in converting end life products into new materials. The polymer waste used strictly determines the structural, textural and surface properties of the final carbon adsorbent. Many different raw materials are used for the fabrication of activated carbon, for example, coal, biomass [2, 3, 4].
This article aims to the development of carbonaceous materials by pyrolysis of polymeric wastes (such as plastic wastes, biomass) as functional adsorption media in wastewater treatment for the degradation of organic pollutants and heavy metals.

KEYWORDS: Asbestos, Powdered-cosmetic talc, SEM-EDS, SR SAXS, SR IR

It is well-known that asbestos is a fiber causing lung diseases, such as asbestosis and mesothelioma. Talc is used for commercial applications such as paints, plastics, papers, ceramics, construction materials, and cosmetics. It is found that the cosmetic talc powder is used for preventing diaper rash, as a deodorant. Samples of cosmetic talc powder are selected from the various markets in Thailand. A scanning electron microscope coupled with an energy dispersive X-ray spectrometer (SEM-EDS) is used to characterize the microstructure and elemental composition. The facilities of synchrotron radiation such as small-angle X-ray scattering (SR SAXS) and infrared spectroscopy (SR IR) are also carried out to determine their phase composition and functional groups. It is found that some samples showed like-asbestos structures. Their compositions are mainly contained with silica and magnesium. The various constituents of the composition are in the form of the functional groups along with wavenumber.

Stellite 6B superalloy is widely used in the harsh industrial environment, because of excellent wear characteristics, hot hardness, good corrosion resistance, and superior mechanical properties [1-8]. Dynamic recrystallization (DRX) is considered as one of the most important microstructural evolution mechanisms, which is beneficial to obtain fine metallurgical structures, eliminate defects and improve mechanical properties of products [9-14].Hot compression tests were performed on Stellite 6B alloy to study high temperature dynamic recrystallization behavior during thermal deformation. The tests were performed in the temperature 1000 °C, 1050 °C, 1100 °C, 1150 °C and 1200 °C and at the strain rates of 0.001 s−1, 0.01 s−1, 0.1 s−1, 1 s −1 and 10 s−1. Stress-strain curves, constitutive relationship, and the DRX model of the Stellite 6B alloy were investigated. The results showed that the dynamic recrystallization was easily beginning, the dynamic recovery process is inhibited, and the softening effect by dynamic recrystallization is more significant.

Reversible solid oxide cells (rSOC), which can act as an electricity and heat generator converting the chemical energy of fuel, as well as an electrolyzer generating hydrogen in the reversed mode operation (exploiting surplus electrical energy), are considered as unique energy conversion devices [1, 2]. Their application seems to be especially suitable in the dispersed power systems, possibly enabling to address unresolved problems of power grid balancing. For their effective work, electrochemical reactions taking place at the electrodes must be sufficiently fast and reversible, which requires for the electrode materials to possess a number of specific properties, including high electrocatalytic activity and suitable thermomechanical properties. Nowadays, Co-based perovskite-type oxides are most widely-used compounds for the air electrodes, however, political and environmental factors indicate a need to replace Co with other 3d transition metal elements. In various proposed materials Co was successfully replaced by e.g. Fe or Mn [3, 4], there are not so many papers available on the possible introduction of Cu. However, several already published works show that Cu-based perovskite-type oxides can work effectively when used in the SOCs [5].
In this work, different issues related to the development of Cu-containing air electrode compounds are discussed, focused on the proposed RE_1-xA_xCu_xO_3-δ (RE: selected rare-earth elements, A: selected alkaline-earth metals) perovskite-type oxides. The considered materials were explored concerning their crystal lattice, thermal expansion behavior, oxygen content, as well as mixed ionic-electronic transport properties. For the exemplary La_1.5Ba_1.5Cu₃O_7±δ, two synthesis routes, sol-gel and solid-state, allowed to successfully obtain pure material. The synthesized perovskite exhibits favorable physicochemical characteristics, including layered crystal structure, and mixed Cu²⁺/Cu³⁺ states, which can be linked with the enhanced activity of the oxygen reduction/oxygen evolution reactions. The stabilized layered crystal structure with P4/mmm symmetry is beneficial to the enhanced electrical conductivity, at the same time allowing to keep moderate thermal expansion coefficient (ca. 15.5·10^-6 K^-1 at 50-900 °C). Additionally, laboratory-scale button-type cells (in the electrolyte-supported and the anode-supported configurations) could be manufactured and tested in terms of their electrochemical performance, confirming applicability of the developed material.

Li-Ion batteries are the technology of choice for most of today’s applications, especially those demanding high energy densities. Large part of this success is due to intercalation electrodes, like graphite in the negative electrode and lamellar oxides in the positive electrode, which constitute a limit in term of energy density and power. Renewable energy and especially electric mobility demand a considerably higher energy density, which is unlikely to be met with the current technology. Therefore, investigating new materials to overcome these limits is fundamental. In this presentation, both cathode and anode developments will be considered. In the first part, we will concentrate on overlithiated rock salts that are promising cathode materials for Li ion high energy applications. Despite the earlier results, these materials can offer much higher capacities (>250 mAh/g) than the stoichiometric compositions. This high capacity is associated to Li rich content that forms a good percolation network along the Li diffusion channels [1]. Lithium titanium sulfide (Li2TiS3), which has been reported by Sakuda et al. [2], demonstrated excellent capacity owing to the multielectron redox reactions. Upon cycling, more than two lithium ions were reversibly intercalated through the structure and the capacity reached 425 mAh/g. Besides these promising results, low electronic conductivity as well as poor cycling stability were also reported. To eliminate such disadvantages, doping or substitution can be an effective solution. Here, we propose new patented selenium substituted lithium titanium sulfide materials [3-4], which have been prepared by high energy ball milling. New materials showed better cycling stability than the current material. For a comparison, we will also provide a comprehensive study of these materials through fine characterization tools (XRD, SEM, EDX, voltammetry, XPS, ex situ and in situ XRD) in order to examine electrochemical and structural properties as well as the degradation mechanism. In the second part, we will focus on Lithium metal that represents the ultimate candidate for the negative electrode, due to its high energy density and low potential. The major drawback of this technology is the formation of dendrites, which are structures that are formed on the surface of the metal electrode during the cycles of dissolution/precipitation. They cause loss of cyclable lithium, therefore they are responsible for the limited lifetime of this technology and may cause short-circuit and thus battery failures. Therefore, it is fundamental to understand the formation of these structures. The proposed model lies on the solid theoretical basis provided by Newman and Monroe [5], in which they proposed a steady-state model that considers the effect of the mechanical properties on the lithium deposition. On the other hand, the presented model is time-dependent and it adds the study of a pseudo-2D Solid Electrolyte Interface (SEI) component, starting from the work of Liu and Lu [6] in which both SEI creation, due to side reactions, and SEI fractures, due to change in geometry, are considered. Different from it, the effect of the mechanical properties of the SEI on the reaction kinetics is taken into account in this work. The surface of the electrode changes in shape due the electrodeposition of the lithium, which is proportional to the current on the surface, modeled with a modified Butler-Volmer kinetics. The model, with an example of results given in figure 2, is designed to be integrated with parameters that are found with a consistent set of experiments. Electrochemical Impedance Spectroscopy (EIS) and Atomic Force Microscopy (AFM) are conducted to find electrochemical and mechanical properties of the SEI. The proposed model has the goal of guiding the experiment in finding ways to avoid or curtail dendrites formation, being able to simulate the effect on dendrites growth depending on operative condition, SEI and electrolyte composition, electrode surface defect and coating.

The development of structural materials for plasma facing components such as divertors in thermonuclear fusion reactors, which are being researched for practical application around 2050, is urgently needed. When metallic zirconium is used for the plasma facing surface and blanket of a divertor for thermonuclear fusion reactor using liquid metal [1][2], zirconium oxide film is coated as a corrosion resistant film and has excellent compatibility with liquid metal during operation. To give the film high fracture resistance, it is necessary to make it densely. The self-oxidation, in which the metal surface is kept under a controlled oxygen atmosphere at high-temperature, is one of the promising method to prepare oxide films.
The purpose of this study is to elucidate the effect of atmospheric gas species on the film formation mechanism and microstructure by forming oxide films by self-oxidation in dry oxygen gas or a mixed gas of water vapor and nitrogen.
The rate of temperature increase/decrease, holding temperature, and holding time for film forming conditions were 5 °C/h, 500 °C, and 10-100 h, respectively. The atmosphere was controlled by flowing an enough 3% H₂O/97% N₂ or dry O₂. The prepared samples were analyzed by SEM/EDS or XRD analysis.
In the oxide film prepared in a dry oxygen atmosphere, only a short crack with a width of about 0.2 µⅿ was generated in the film in the direction parallel to the interface between the oxide film and the metal. On the other hand, in the case of the mixed gas of water vapor and nitrogen, in addition to short cracks, long cracks with a width of about 0.4 µⅿ also generated. In the XRD analysis, the diffraction peak of the oxide film prepared in the mixed gas of water vapor and nitrogen was shifted to the lower angle side than that of the oxide film prepared in the dry oxygen atmosphere.
When zirconium is oxidized in an atmosphere containing steam vapor, hydrogen is generated in addition to zirconium oxide. Therefore, it was suggested that the elongation of the crystal lattice is due to solidification of hydrogen as interstitial atoms and that the resulting strain is the cause of large cracks.

The demand for high-purity lithium for lithium-ion batteries will continue to grow rapidly. It is necessary to establish a technology to recover lithium from spent lithium-ion batteries with low cost and environmental impact. Electrodialysis using lithium-ion solid electrolytes is a promising candidate technology. However, the recovery rate and energy efficiency are still small, although it has been reported that lithium can be recovered in high purity [1-3]. In the electrodialysis technology, it is generally predicted that the lithium recovery rate will increase according with the applied voltage according to Ohm's law. However, in electrodialysis using La_0.57Li_0.29TiO₃ (LLTO) as an electrolyte, the increase in lithium recovery rate due to increase applied voltage exceeded this prediction. The purpose of this study is to determine the cause of this phenomenon.
An anode (primary solution side) and a cathode (secondary solution side) were formed on both front and back surfaces of LLTO. Reference electrodes were also formed on both surfaces. DC voltage of different magnitude was applied between the anode and the cathode, and the dependence of the applied voltage on the electrolyte resistance was investigated by two-probe AC impedance spectroscopy. The applied voltage dependence on the electrode reaction resistances of the anode and the cathode was investigated by three-probe AC impedance spectroscopy using a reference electrode. Lithium recovery was measured by inductively coupled plasma optical emission spectroscopy.
The electrolyte resistance of LLTO and the anode electrode reaction resistance were constant at all applied voltages. On the other hand, as the applied voltage increased, the cathode electrode reaction resistance decreased in a quadratic manner. The increase in lithium recovery rate, contrary to Ohm's law, is attributed to this decrease in the cathode reaction resistance.

The energy storage systems market was dominated by Li-ion batteries (LIBs) almost as soon as they were commercialized in 1991. Demand for this technology is forecasted to grow further, especially with the growing use of renewable energy sources, which need reliable, high efficiency and high capacity energy storage system [1]. However, limited lithium abundance in the earth’s crust intensifies the search for an alternative technology. Na-ion batteries is a proposed solution, because of similar to the LIBs operation mechanism and abundance of sodium on earth. Nevertheless, the lack of appropriate anode materials is one of the major hindrances in the development of that technology. The most common anode material for Li-ion batteries – graphite, intercalate Na⁺ ions only in a limited range. Researchers' attention is drawn to elements from the 14 and 15 groups of the periodic table, working in Na-ions via alloying materials. Among them, antimony stands out because of its high electrical conductivity (2,56·10⁶ S m^-1) and also the high theoretical capacity of 660 mAh g^-1 [2]. However, the volume change related to alloying/dealloying process is approximate 293% which causes severe microstructure degradation and as a result impeded reaction kinetics and poor cycling stability [3]. The prospective strategy to overcome obstacles is synthesizing the nano-sized Sb.
The aim is to elucidate the relationship between physicochemical properties, size, and morphology of Sb-particles. The work presents a comparison of structural and electrochemical properties of nano-sized antimony synthesized via hydrothermal reaction [4] and bulk micrometric Sb. The X-ray diffraction and scanning electron microscopy were conducted to specify the structural properties of materials. The electrochemical properties of the materials were verified by means of the standard charge/discharge cycles, rate capability tests, XRD in situ measurements, CV voltammetry, and electrochemical impedance spectroscopy.
The voltage profiles confirm that during the alloying the Na₃Sb phase was formatted. The nanosized materials decreased stress-strain and as a result, improved cycle stability of cells.

Photocatalytic hydrogen production through water splitting based on semiconductor catalysts has been the subject of intense research since it delivers an alternative to substitute fossil fuels with clean and renewable energy [1]. In the pioneering work, in 1972, Honda and Fujishima [2] successfully demonstrated photocatalytic H2 generation by water splitting using semiconductor photo-catalysts. Photocatalytic water splitting by utilizing broadband spectral response from UV to near-infrared (NIR) region is a big challenge and yet a prime target. 50% of the solar spectrum constituted by NIR light, and in this work, our objective is to increase absorption range from UV-visible to NIR by using (UCNPs)-Pt@MOF/Au composites. In this context, lanthanide-doped upconversion nanoparticles (UCNPs) can convert NIR to UV and visible, which are then harvested by the metal-organic framework (MOF) and Au. MOF and plasmonic Au nanoparticles (NPs) broaden the absorption of UV light to a visible region as well as speed up the transfer of charges considerably [3]. For this experiment, we used MIL-125 as a MOF because it is a wide-bandgap semiconductor [4]. The spatial separation of Pt and Au particles by the MOF further steers the charge migration and also provides access to active Pt sites for the catalytic product; as a result, the optimized composite exhibits high photocatalytic H2 production rate under UV, visible and NIR regions.

An analysis of the scientific literature of recent years shows that in the world practice of gold mining, the main method for extracting gold from ores and concentrates is the cyanide method, which, when applied to refractory sulfide ores, does not give economically feasible indicators and is highly toxic [1]. The electrochemical technology developed by us for leaching gold-bearing sulfide ores allows us to solve the problem of increasing the completeness of the use of natural resources while reducing the environmental load on the environment [2]. To implement this method, we designed and tested an open execution electrochemical reactor, which greatly simplifies its maintenance compared to the existing one [3].The process of opening a sulfide mineral is carried out in the anode space of the reactor and, using the selective complexing agent of noble metals present in the solution, the gold from the mineral passes into the solution in the form of a cation exchange complex, which migrates into the cathode space through a perchlorovinyl diaphragm and is discharged at the cathode with the release of metallic gold. The first two operations take place in the anode space, and the third in the cathodic. A carbon fiber material with a highly developed surface is used as a cathode, increasing the intensification of the cathode process. The anode and cathode spaces are separated by heat-treated perchovinyl fabric, which is a good filtering material that protects the cathode space from the penetration the anode space of even the smallest particles from. The design of the electrochemical reactor allowslead an ongoing process of leaching oreand the release of metallic gold at the cathode. KEYVORDS : Sulfide ores, electrochemical processing, electrochemical reactor

Nowadays, Li-ion batteries are dominating electrical energy storage systems for portable electronics, and become widespread in the fast developing electric vehicles market. Their further development is also essential for the so-called large-scale energy storage, enabling effective balancing of power grid. Consequently, there is a growing worldwide demand for the next generation of Li-ion cells, having higher energy density, higher power, improved safety, and extended lifespan. Up to date, many novel alternative materials have been proposed as substitution for those currently used in the commercial Li-ion cells, which are usually based on lithium metal oxide cathodes and graphite anodes [1,2]. Among new candidate anode materials, those working on a basis of different reaction mechanisms with lithium have been proposed, including conversion-type and alloying-type reactivity, as compared with intercalation-based electrochemical reaction occurring for commonly used graphite. While high capacity could be obtained for various studied compositions, there are still many unresolved issues, with the main one including fast capacity fading during charge-discharge cycles [2].
Most recently it has been found that application of the novel group of compounds, the multi-component high-entropy oxides, allows significantly improving stability during cycling, which is thanks to synergistic effects [3]. In the literature there is an ongoing debate about electrochemical mechanisms occurring for the high-entropy electrodes, which have not been fully understood yet [3,4,5].
This work is focused on the exploration of the high-entropy oxides as anode materials in Li-ion cells. The presented studies were aimed on finding the correlation between chemical composition, crystal structure and electrochemical performance. Different, at least five-component oxides from Li-Co-Cu-Cr-Fe-Mn-Ni-Mg-Sn-Zn-O system were successfully synthesized, with their crystal structure characterized through X-ray diffraction method, to be cubic Fm-3m for MO, and Fd-3m for M₃O₄ materials, respectively. Homogeneity of the compounds was confirmed with scanning electron microscopy, combined with elemental analysis. In order to test electrochemical performance in Li-ion batteries, galvanostatic charge/discharge, cyclic voltammetry and impedance spectroscopy techniques were used. Interesting results, with high and reversible capacity observed for both groups of the studied high-entropy oxides were obtained. For example, for (Co,Cr,Fe,Mn,Ni)₃O₄-based anode discharge capacity exceeding 400 mAhg^-1 was measured in the first 20 cycles. Based on operando structural investigations, the respective models of the electrochemical reactions could be postulated. The performed studies proved applicability of the high-entropy approach to design novel Li-ion anode materials having improved electrochemical characteristics.

Research objects used herein are chemical and holistic test methods for spring barley and ozonated grain. The aim of this research project is to (1) analyze the influence of ozone-saturated water spray on chemical and electrochemical parameters of spring barley grain, (2) determine the electrochemical characteristics of barley grain grown by spraying with ozone and water by seasonality, (3) evaluate the electrochemical parameters of barley grain according to the applied technologies, and (4) analyze the possibilities of applying the method of biocrystallization for the quality of spring barley grain. Methods used include identification of chemical and electrochemical parameters, biocrystallization, and analysis of numerical values of independent evaluators. After the evaluation of spring barley cultivated using ozone-sprayed water, no statistically reliable effect of ozonated water on grain quality was established. Spraying with more water (plain and ozonized) shows a downward trend in numerical values of absolute redox potential. The lowest energy P numerical values were calculated for barley grain, which was sprayed with water 4 times. Biocrystallization method for barley grain quality requires further preparation of the methodology.

The Limnoperna fortunei – golden mussel is a mollusk of the bivalve class [1], which in this exploratory study has the complex microarchitecture of its shell as the target of our investigation. The objectives of this research are: to identify the mineral phases present in the shell using X-ray diffraction, to determine the hardness by the ultramicrohardness test and with the scanning electron microscope to visualize the existing layers. The mineral phases: calcite and aragonite were identified. The ultramicrohardness test was carried out on the innermost layer of the shell, the prismatic layer of aragonite, and the results found are consistent with the literature. Visualization of the periostracus, calcite layer, nacreous layer and prismatic layer was performed successfully. The results obtained allowed a better understanding of the analyzed material, which motivated us to deepen and advance in our studies.

The author of this work based on her own investigations of LixMO2 cathode materials (M=Ni, Co, Mn, Cu) has demonstrated that the chemical disorder influenced on electronic structure of these materials plays an important role in the electrochemical intercalation process [1].
The paper reveals correlation between chemical disorder, crystal and electronic structure, transport and electrochemical properties of layered LixCoO2, LixNi1-y-zCoyCuzMn0.1O2 and NaxCoO2-y cathode materials and explains of apparently different character of the discharge/charge curve in those systems. Comprehensive experimental studies of physicochemical properties of LixNi1-y-zCoyCuzMn0.1O2, NaxCoO2-y and NaNi1/5Co1/5Fe1/5Mn1/5Ti1/5O2 cathode materials (XRD, electrical conductivity, thermoelectric power) are supported by electronic structure calculations performed using the Korringa-Kohn-Rostoker method with the coherent potential approximation (KKR-CPA) to account for chemical disorder. It is found that even small O defects (~1%) may significantly modify DOS characteristics via formation of extra broad peaks inside the former gap leading to its substantial reduction. Moreover, these DOS peaks of “defects” strongly evolve with Li and Na contents, actually leading to the overall reduction of the gap and even to the pseudogap.
The battery on the base of the developed high entropy oxides NaNi1/5Co1/5Fe1/5Mn1/5Ti1/5O2 cathode materials are characterized by high potential, high capacity and high rate capability guaranteeing high energy and power densities.
Acknowledgements
This work was funded by the National Science Centre Poland (NCN) under the “OPUS 17 programme on the basis of the decision number 2019/33/B/ST8/00196.

Eduard Akim¹, Aleksandr Pekaretz¹, Michael Akim², Svetlana Rogovina³, Alersandr Berlin^3
1St. Petersburg State University of Industrial Technologies and Design, St. Petersburg, 191186 Russia
²HSE University, Moscow, 119049, Russia
³Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, Moscow, 119991 Russia
Key words: solid biofuels, relaxation state, torrefied briquettes
Forests are the main natural sink of greenhouse gases in terrestrial ecosystems in the world while providing the main reproducible resource – wood, which is increasingly used for the production of fuels, according to the international classification, with a zero carbon footprint. In 2020 the global production of solid biofuels (SBF) of the second generation – pellets and briquettes exceeded 50 million tons. Russia exported 2.3 million tons of pellets and briquettes in 2020, while a number of Russian Forestry Companies are implementing ESG programs.
The development and widespread use of biofuels is one of the main sustainability trends, particularly in energy sector, but not without criticisms, therefore an effectiveness of biofuel production, logistics and usage is crucial. For instance, excessive cultivation of plants used for biofuel production could exacerbate climate change and destroy the sensitive ecosystems, might contribute to world hunger because land is being used to grow trees, oil palms, soybeans, and sugarcane rather than food. In the context of shrinking global resources with a growing population of the planet, improving the efficiency of wood use, in particular, in the production of SBF of the second generation, is critical.
We have developed and implemented a new technology of producing of HDSBF - cellulose composites for energy purposes - wood briquettes with a density of up to 1300-1320 kg/m3. The technology is based on a directed change of relaxation state of polymeric components of wood at the principal stages of HDSBF production [1-3].
The transition to energy-saving technology is carried out at the expense of the brittle destruction of sawdust dried in aerodynamic conditions to practically zero moisture content, and their dispersion - transformation into a powder material. The extrudability of the powder is ensured by subsequent steam humidification. An anomaly of the apparent viscosity of the wood system in the extruder due to the joint action of water vapor, gaseous pyrolysis products, as well as temperature and shear stresses was found. As a result of extrusion wood briquettes with a density up to 1300-1320 kg/m3 are obtained.
Having a high density, these briquettes during production can be subjected to torrefication and carbonization with the formation of high-calorie hydrophobic products - torrefied briquettes (TB) and carbonized briquettes (CB), suitable for both combustion and sequestration of carbon [2-5]. At the same time, pellets can be torrefied together with briquettes. TB and pellets are especially in demand for co-firing at coal-fired power plants.
Five technological lines have been launched in Russia based on this technology [2-4]. A similar bio-fuel production facility has been established in Riga (Latvia), where a machine-building production according to the EU standard has also been created.
The specific features of this technology and arising changes in the polymer structure allows one to use it not only for processing of sawdust, but also for utilization of plastic waste and hydrolytic lignin from dumps. In the latter case HDSBFs with properties corresponding to TB are directly obtained.

Even though they are considered as a symbol of the green revolution, Li-ion batteries are mostly made of components that consist of difficult to obtain, toxic and expensive raw materials. From this point of view, Na-ion batteries, based on available and non-toxic elements, seem to be a better solution for the future [1–3]. The working mechanism of both Li-ion and Na-ion batteries based on intercalation is similar. Since cathode material’s properties have the most significant impact on cell performance, numerous systems are investigated in this role. Among layered oxides, especially Na_xMnO₂-based cathode material (NMO) is under consideration due to its high capacity and low-cost elements [4].
Since NMO has several drawbacks, such as relatively low stability upon cycling, Mg substitution was applied to stabilize its crystal structure. The presented work shows the substitution influence on structural and electrochemical properties.
Investigated materials were obtained via a sol-gel method. Their structural properties were then analyzed by X-ray diffractometry, whichconfirmed the single-phase hexagonal structure with P6₃/mmc space group. The morphology of the samples, performed by Scanning Electron Microscopy, showed grains of few micrometers in size. Electrochemical impedance spectroscopy was used to investigate the conductivity and revealed that the Mg-substituted sample indicates the conductivity higher by an order of magnitude than NMO. The ionic process's activation energy was 0.19 eV for NMO and 0.33 eV for the Mg-substituted sample. The samples were used to prepare coin cells, which have undergone electrochemical tests. Na/Na⁺/Na_xMg_0.2Mn_0.8O₂ cell retains specific capacity exceeding 100 mAh/g after over 120 cycles at 200 mA/g (1C) current rate with the undistorted crystal structure.
The conducted research allowed to obtain cheap and environmentally friendly cathode material for Na-ion batteries. Mg substitution resulted in increasing structural stability upon cycling.

There are great interest on hydrogen as an environmentally friendly sustainable energy source and carrier for automotive and fuel cell applications as well as in many industrial processes. Hydrogen gas is colorless, odorless, and extremely reactive with oxygen, and has very low ignition energy. Therefore, hydrogen gas sensing systems are essential in various hydrogen related applications including water splitting, hydrogen storage, and fuel cell vehicle. β phase Ga2O3 (β-Ga2O3) has recently gained a lot of interest for applications in high power devices, solar-blind photodetectors, and gas sensors [1]. The interest stems from its intrinsic material properties, such as wide bandgap nature of 4.9 eV and high breakdown electric field of 8 MV cm−1, leading to making its devices more efficient with small size dimensions for high power device and harsh environmental sensor [1-3]. The wide bandgap nature also enables Ga2O3 based electronic devices to operate at high temperatures due to its low intrinsic carrier concentration. Among the various polymorphs of Ga2O3, β-Ga2O3 is the most stable crystal structure over the whole temperature range up to its high melting temperature of 1700°C [1]. The other polymorphs are metastable and they transform into β-Ga2O3 at temperatures above 750- 900°C [1,2]. In this study, the fabrication of 2 dimensional β-Ga2O3 flake base field effect transistor and its hydrogen sensing characteristics for hydrogen sensor application will be discussed.

The quest for improved energy storage to counter our dependence on fossil fuels and for the electrification of transport and large-scale storage is one of the greatest scientific challenges of the 21st century. This quest has strongly evolved into priority areas in global research strategies. Countries are investing heavily in renewable energy technologies with the aim of achieving net-zero emissions by 2050. To achieve this ambitious target, transformative advances in the understanding, design and development of materials are critical. Interfaces and ion transport are central to the performance of energy materials and devices, particularly batteries. The materials that support practical ion conduction in batteries exhibit stunning heterogeneity and complicated ion diffusion mechanisms and interfacial processes, which determine their functionality, performance and longevity. Transforming our comprehension of interfaces and ion transport in energy materials will therefore directly contribute to combatting the global energy crisis, as well as delivering key fundamental research advances in materials science, chemistry, physics and engineering.
In this presentation, the recent advances made by my research group in the atomistic simulation of ion transport and interfaces at the nanoscale in solid electrolytes for solid-state batteries will be disseminated. The solid-state battery represents a prime example of a next-generation battery technology with the potential to revolutionise energy storage. Nevertheless, the solid-state battery maybe the battery technology of the 2030s but it remains the research challenge of the 2020s and faces several fundamental challenges that must be overcome for its true commercialisation.

The development of new proton exchange membranes (PEMs) has gained growing attention in the last few years for their use in electrochemical devices [1]. Fuel cell, FC, technology is among the most relevant applications of PEMs. FCs directly convert chemical energy into electricity. A wide range of materials has been tested as membranes in fuel cells. Perfluorinated polymeric sulfonic acids (commonly known as Nafion^®), however, are considered the standard PEM membrane type due to their advantageous properties, which include high proton conductivity, good mechanical strength and long lifetime. These advantages are counterbalanced by the high cost and the operational limitations under non-humidified and high-temperature conditions. On their part, polymeric ionic liquids (PILs) are attracting growing research interest as fuel cell membrane electrolytes because of their numerous advantages since they combine the unique properties of ionic liquids (ILs) and the intrinsic properties of polymers [2].
Several strategies to promote PIL membranes have been reported to date, based on (i) the incorporation of ILs into a polymer network by mixing both phases, typically by casting techniques, (ii) formation of solid membranes through conventional polymerization of IL monomers and (iii) a new attractive alternative consisting of IL photopolymerization, since this technique provides short synthesis times at room working temperatures and easy control [1].
This works focuses on the development of new PEMs through the photopolymerization of protic ILs such as 1-(4-sulphobutyl)-3-vinylimidazolium trifluoromethanesulphonate, ([HSO₃-BVIm][TfO]). Several strategies have been followed to assess the performance of IL-based membranes: (i) photopolymerization of the IL in the absence of other monomers; (ii) photocopolymerization of the IL with methyl methacrylate (MMA) and iii) photocopolymerization of the IL with perfluoro-3,6-dioxa-4-methyl-7-octene sulfonyl fluoride in its hydrolyzed form (hPFSVE). The results show higher values of conductivity for the copolymerized membranes, within the range 10^-3 - 10^-2 S.cm^-1, both in dry and wet conditions and even at room temperature. Thus, the new PEMs offer promising prospects for their application as PEMs in fuel cell devices.

The discovery of WC-Co metal-ceramic composites, cemented carbides, was one of the most important technological revolutions of the last century [1, 2]. Such functional hard materials possess a unique combination of strength and fracture toughness on the one hand, and hardness and wear-resistance on the other hand as a result of combining a hard ceramic phase, tungsten carbide, with a ductile and tough cobalt binder [3]. Nevertheless, presently, for many applications there is a need for hard materials with a significantly improved combination of hardness, toughness and wear-resistance. However, traditional wisdom indicates that hardness and wear-resistance are contradictory and incompatible material properties when compared to toughness, so that in conventional hard materials an increase of hardness and wear-resistance can be achieved only at the expense of fracture toughness [3, 4].
A number of new approaches to the fabrication of novel hard materials with improved combinations of hardness, fracture toughness and wear-resistance were elaborated and implemented in industry.
One of these approaches is based on creating functionally graded WC-Co materials, known as ‘Gradient Carbides’, with a tailored gradient of Co contents from a near-surface layer towards a core region. The novel hard materials comprise a hard surface layer containing much WC phase and a tough core containing lots of Co, which results in an exceptionally high combination of hardness and fracture toughness of the surface layer.
The second approach ensuring the hardness/toughness/wear-resistance trade-off to be overcome is based on employing nanotechnology. A range of novel hard materials with nano/micro hierarchical structure were developed and are presently widely employed in the mining and construction industry. An unusual combination of the ultra-coarse-grain microstructure structured on the µm-level and the binder phase structured on the nm-level provides an extraordinarily high combination of both transverse rupture strength/fracture toughness and hardness/wear-resistance.
The third approach comprises the development and implementation of nanostructured cemented carbides also known as ‘near-nano carbides’ with a WC mean grain size of about 150 nm. These hard materials are characterized by a significantly improved combination of hardness, wear-resistance and fracture toughness, which ensures their dramatically prolonged lifetime in different applications.

A number of studies have shown that modern LED light sources have a noticeable negative effect on human health, affecting the retina of the eye. The harm is caused by short-wave blue and violet light, which in the spectrum of such light sources has in some cases an intensity increased up to 30% compared to ordinary incandescent lamps. For example, in [1] summarized data on the sensitivity to the spectral distribution of light perceived by the eye, showing the dependences of acute UV-blue phototoxicity, spectral sensitivity of melanopsin with a maximum at 479-483 nm, and sensitivity to suppression of the generation of melatonin with a maximum at 459-464 nm, more dependent on blue light than visual functions mediated by rods (rhodopsin).
In order to overcome this drawback of LED light sources, including those used in display backlight systems, the authors of [2] first proposed and developed the concept of LED light sources with a biologically adequate radiation spectrum (BALEDS) [3]. For the production of BALEDS, a technology has been developed for the production of composite photoluminescent films (PLP) from a suspension of a two-component silicone compound OE 6636 (Dow Corning) and photoluminophores based on aluminum-gallium garnets of rare-earth elements activated by cerium with a composition described by the stoichiometric formula Y3-y-zLuyCezAl5-xGaxO12, where 1.8 The PLP containing the photoluminophore (Y2.79Ce0.12Lu0.09Al3.1Ga1.9O12) and excited by an LED with a maximum radiation at a wavelength of 480 nm is used for LED backlight of the augmented reality area of a LCD for projection on a windshield [4].
This work was carried out with the partial support of the RFBR grant (project No. 20-07-01063_a).

Trends that characterize the food industry today include food waste and overproduction in rich countries, as well as malnutrition and hunger among the population of underdeveloped regions. The largest part of food waste is fresh products, including fruit and vegetables, which are prone to spoilage, which makes them short-lived. At the same time, many sectors of the food industry do not manage full-value waste, whose processing potential is possible to use in terms of structure-building, nutritional and nutritional aspects in newly created, innovative products that fit into the strategy of sustainable development by utilizing raw materials, which are unfortunately wasted [1]. The activities undertaken by scientists in the fight against the problem are aimed at seeking the possibility of using available raw materials to produce easy-to-distribute food with an extended shelf life and developing innovative production techniques whose introduction will result in an improvement in the economic situation in the face of the described trends [2,3].
The purpose of the work was to develop a recipe composition and technology for the production of freeze-dried vegetable products formed in the form of bars. The research used full-fledged industrial output from the production of frozen vegetables, i.e. green and yellow-green string beans, carrots and potatoes, and dried apple pomace. As part of the work, selected properties of raw materials and obtained products were also examined. Presented research are the stage of the project BIOSTRATEG 3/343817/17/NCBR/2018 “Development of healthy food production technologies taking into consideration nutritious food waste management and carbon footprint calculation methodology”.
Tests of the properties of finished products have shown that they are characterized by very low water activity, in the range of 0.01 - 0.02 and humidity not exceeding 2%. The obtained freeze-dried vegetable bars were characterized by high porosity at the level of 86.8-89.5% depending on the composition of the vegetable input. The high porosity and low content and activity of the finished products obtained determine their hygroscopicity, which has a significant impact on the need to select optimal storage conditions in terms of the type of packaging due to its barrier, temperature and humidity of the surrounding environment.
It was shown that the shrinkage of freeze-dried vegetable products formed in the form of bars resulting from the freeze-drying process was at the level of several percentage points, and its size was dependent on the composition of the processed vegetable feed, in accordance with the developed innovative technology. It was observed that the more the material volume decreased, the higher the density and lower porosity of the finished products.

Concern about the energy crisis and the environmental contamination resulting from the burning of fossil fuels has motivated scientists to look for sustainable and environmentally friendly alternative energy sources. Photocatalytic dissociation of water for the production of hydrogen under solar irradiation is seen as a promising strategy for solving energy and environmental problems, as hydrogen is a clean and renewable energy source. Hydrogen is associated with fuel cells, an alternative technology to the internal combustion engine, and could replace the conventional hydrocarbon/combustion engine option since the reaction involved produces only water and electrical energy. Since the pioneering results obtained by Fujishima and Honda in 1972[1] on the production of hydrogen by photoelectrochemical dissociation of water using a TiO2 photo-anode and a Pt cathode, much work has been done on the photocatalytic dissociation of water using semiconductors. Among potential semiconductors, TiO2 remains the most suitable photocatalyst in terms of chemical inertness, low cost, non-toxicity, availability and long-term stability against photochemical corrosion. However, the efficiency of TiO2 for photocatalytic dissociation of water is limited due to the high probability of recombination of photo-induced electron holes and its limited photoactivity to UV radiation. In order to overcome these drawbacks, numerous studies have been conducted to improve the photoactivity of TiO2[2][3], including the synthesis of nanostructured TiO2 and the doping of TiO2 by noble metals, in particular by Ag. This research is a continuation of this work and aims to develop photocatalysts based on silver-doped mesoporous oxides and to evaluate them in the production of H2 by dissociation of water under UV and visible light irradiation.

While large-size switching processes triggered by light are abundant in the chemical literature, such processes ignited by redox activation are rather scarce, in particular concerning the recent developments of molecular machines. Very recently, though, various advancements in the field of molecular machines have been reported by Stoddart, Nobel laureate of chemistry 2016 [1].
Here we will report about the bright prospects of redox-triggered self-sorting [2] that has been exploited in our group for nanomechanical switching, toggling ON/OFF catalysis, cargo transport and molecular communication. From a design point of view, the switching requires highly dynamic self-sorting protocols involving often 6-12 distinct components and a rich tool box of orthogonal binding motifs. Due to the fact that one-electron oxidation/reduction is orthogonal to many chemical trigger events, we have amply utilized redox activation within molecular networks and elaborated on the arena of molecular cybernetics.
The high-speed network [3] of two communicating switches can be set up to bind (catalysis OFF) and release a catalyst (catalysis ON) via redox inputs and translocation of copper(I) ions as a second messenger. In the ON state, the released catalyst promotes an organocatalytic reaction. Both the field of switchable catalysis and the present work represent distinct advancements on the road to fully regulated, networked catalytic machinery [4].

Ceramic membranes, due to their high permeability, ability to work in the aggressive environment, including high temperature and high pressure, chemical and mechanical stability seem to be promising substitution compared to the commonly used polymeric membranes. Despite their higher investment cost, in relation to the organic membranes, ceramic gas separators are more economically favourable in long term perspective (slower degradation) [1,2] Similarly to Solid Oxide Fuel Cells (SOFCs) and Solid Oxide Electrolyzer Cells (SOECs), membrane technologies are considered as one of the basic solution in so-called Grand Energy Transmission [3-5].
Ruddlesden-Popper-type (RP) oxides usually possess mixed ionic-electronic conductivity, which is a crucial requirement for the effectively-working ceramic membranes. Ionic transport in the considered group of materials might be realized by the vacancy mechanism (in the perovskite-type layer) or by rather unusual interstitial mechanism employing interstitial oxygen. In this work RP Nd_2-xNi_0.75Cu_0.2M_0.05O_4±δ (x = 0 and 0.1; M = Ga, Sc and In) oxides were obtained by a sol-gel route and characterized concerning phase composition and crystal structure. Among the materials, Nd_2-xNi_0.75Cu_0.2Ga_0.05O_4±δ (x = 0; 0.1) were selected, with systematic characterization of the crystal structure at high temperatures, oxygen content, as well as transport properties measured. It is shown that the Nd-site deficiency causes decrease of the oxygen content, which at high temperatures leads to a change of the dominant type of defects from the oxygen interstitials to the vacancies. Importantly, both examined Ga-containing materials exhibit full chemical stability in CO₂ atmosphere, which makes them good candidates for air separation technology. Ceramic membranes manufactured using Nd₂Ni_0.75Cu_0.2Ga_0.05O_4±δ and Nd_1.9Ni_0.75Cu_0.2Ga_0.05O_4±δ fine powders allowed to obtain very high oxygen fluxes equal to 0.69 mL cm^-2 min^-1 and 0.78 mL cm^-2 min^-1 at ca. 880 °C, respectively for 0.9 mm thick pellets. Moreover, it is shown for Nd₂Ni_0.75Cu_0.2Ga_0.05O_4±δ-based pellet that infiltration of the grains with the higher order RP oxide (e.g. La₄Ni₃O₁₀) combined with reduced thickness of the membrane allows to maximize oxygen flux values, with one of the highest reported oxygen fluxes measured for CO₂-stable RP-based ceramic membrane, i.e. 0.94 mL cm^-2 min^-1 at ca. 880 °C for 0.6 mm thick dense membrane.

In Georgia (Bolnisi region) along with major sulfide ores, containing colored and noble metals, there are low-quality, hard-enriched gold-containing copper oxidized ores and secondary quartzites, the interest in which is steadily growing. The segregation method is effective for the complex processing of this ores. The segregation method was discovered in the 1920s and found practical use 30 years later by the Anglo-American group as a "TORCO" process (Treatment Of Refractory Copper Ores). The segregation method has found application in countries: Peru, Mauritania, USA, Canada, South Africa, Kazakhstan, etc. This method ensures high quality and ecological safety of the extraction of non-ferrous and noble metals. The segregation method on the first stage implies high temperature (750-9000 C) burning of ores in neutral or weak-reduced area in the presence of coal and sodium chloride. Copper and noble metals obtained after the burning chlorides are reduced on the surface of carbon with hydrogen, which is formed by the interaction of water vapor with carbon. Metallic copper and noble metals particles are collected around the carbon. The second stage of processing is carried out by flotation enrichment of the segregation product. As a result of flotation, copper and noble metals are extracted together with coal in a concentrate, the content of which is much higher than in the conventional flotation concentrate. We have conducted work experience using the segregation method. The segregation roasting process was carried out in a tubular rotary kiln. Subsequently, there are conducted the flotation enrichment experiments of the product received after segregation roasting. Segregation roasting was used to extract gold, silver and residual copper from residues of hydro-metallurgical treatment of Madneuli (Bolnisi region) chalcopyrite concentrate. On the basis of technological research, the optimal parameters of segregation roasting of residues after their preliminary oxidative firing were determined: temperature 8500С, consumption of sodium chloride and coal respectively 1% and 1.5% by weight of residue, the duration of the process is 30-60 minutes. Under these conditions, from residues containing 1.1-1.3% copper, 38-40 g/t silver and 3.8 g/t gold, the flotation concentrate with a copper content of 8-9%, silver 232-300 g/t and gold 18-24g/t is obtained. The total recovery to the first and second flotation concentrates is 88-92% copper, 85-87% silver and 88.3-93% gold. A sharp improvement in the quality of the concentrate can be achieved by introducing the cleaning operation into the usual flotation mode (pulp pH 8-11, potassium butyl xanthate consumption 100 g/t and pine oil 50 g/t). The copper content in the first flotation concentrate increases to 42%, gold - 40g/t, silver - 1381g/t. Its yield is 2.3% by weight of the product of segregation roasting. Their extraction is about 80%, and the copper content in the flotation tailings is 0.16%. The results show that the process of segregation of the gold-containing copper oxidized ores and secondary quartzites has a positive effect on the process of further flotation enrichment of the segregation product. The degree of gold extraction in concentrate as a result of flotation of segregated product obtained by roasting of secondary quartzites (Au - 2 g/t, Cu - 0.021%) is 80%, and that of copper- 77%. Although concentrates with a gold content of 14-24 g/t have been obtained, studies are still ongoing to determine the optimal mode. Segregation was also carried out on copper oxide ore (Cu - 3.5%, Au - 0.5 g / t). The results of experiments conducted on both ores indicate the effectiveness of the segregation process in both cases. Currently, we are pointed on the determination of conditions for the optimal proceeding of the process.

Hydrothermal treatment (10≤P≤200 bar and 150≤T≤325°C) has been proven to be efficient for the synthesis of materials with advanced properties [1]. Power ultrasound is also applied for similar purposes [2]. We have developed an innovative reactor providing simultaneous ultrasonic and hydrothermal treatment, called sonohydrothermal (SHT) reactor, which allows to benefit from the advantages of both techniques. Physical and chemical effects of power ultrasound derive from acoustic cavitation, that is, formation, growth, and implosive collapse of gas-filled microbubbles in a liquid subjected to ultrasonic waves (f>16 kHz). Acoustic noise spectra (ANS) revealed that the effects of 20 kHz ultrasound in hydrothermal water are mostly driven by stable cavitation. In the entire range of studied conditions the ANS exhibit several harmonics (nf₀, f₀=20 kHz) indicating nonlinear bubble oscillations synchronized with the fundamental frequency f₀. However, the spectra at 200°C and pressure of 14 bar are more specific and characterized by strong subharmonic (f₀/2) and multiple ultraharmonic (nf₀/2) bands. In addition, these spectra exhibit numerous stochastic oscillations in the vicinity of principal lines indicating strong contribution of chaotic bubble behavior. Addition of TiO₂ nanopowder to SHT reactor heated at 200°C causes the disappearance of subharmonics, ultraharmonics and stochastic oscillations, which can be explained by the stabilization of oscillating bubbles due to the Pickering-like effect.
SHT treatment (T=150-200°C, P=6-14 bar) of titanium metal nanoparticles in pure water provides a facile synthetic route to prepare core-shell Ti@TiO₂ nanoparticles composed of quasi-spherical metallic Ti core (20-80 nm) coated by 5-15 nm crystals of defect-free anatase with small amounts of rutile [3]. Ti@TiO₂ NPs exhibit strong photothermal effect in H₂ production from aqueous solutions of glycerol and pure water as well [4]. The apparent activation energy (E_a=32±2 kJ·mol^-1) assumes that photothermal effect arises from diffusion of intermediates or from water dynamics at the surface of catalyst.

A gel-based cellular structure should be characterized by appropriate physical and sorption properties according to its intended use [1]. Both the method of preparation and storage of ingredients, semi-finished and finished products are of great importance in shaping the quality and health safety of prepared meals. It is during storage that a number of processes, e.g. microbiological, biological, chemical, biochemical or physical, occur that cause qualitative changes in them. Researchers were investigating the effect of drying methods and conditions, different equipment solutions and the storage conditions on the quality of final product [2, 3].
The aim of this work was to investigate physical properties of three-layer freeze-dried vegetable snacks in the form of bar stored in different relative humidity conditions. Bars were obtained based on waste unused during proper production of frozen vegetables. Presented research are the stage of the project BIOSTRATEG 3/343817/17/NCBR/2018 “Development of healthy food production technologies taking into consideration nutritious food waste management and carbon footprint calculation methodology”.
Sodium alginate, and a mixture of xanthan gum and locust bean gum were used for the formulation of vegetable gels with cauliflower, broccoli, carrot, potato, green and yellow bean, corn, chives, pepper, dill. Vegetable gels were frozen (–40 °C/2) and freeze-dried (30 °C/63 Pa/72 h). The physical properties of freeze–dried bars included determination of: sorption isotherms, water activity, porosity and shrinkage.
The studies showed that the type of hydrocolloids and vegetables influence the sorption properties of freeze-dried vegetable snacks based on frozen vegetables not used during the proper production of frozen foods. Samples obtained on the base on xanthan gum and locust bean gum mixture were characterized by lower sorption properties than bars obtained with the sodium alginate, especially when water activity in desiccators were above 0,529). Also, vegetable types influence the sorption properties of freeze-dried gels stored in different relative humidity conditions. Such storage conditions (water activity in desiccator 0-093) changed structure which influenced the shrinkage and porosity of freeze-dried vegetable bars after storage during 5 months.

Affiliation: Department of Physics, University of Central Florida, Orlando, FL 32816
Keywords: Graphene Oxide, Biomimetic, nanopores, water purification
Recent advances in synthetic membranes allow their use in fields as diverse as food and agriculture, industrial water treatment, potable water production and biotechnology. Among the newly developed technologies, nanofiltration for liquids and more particularly for desalination of seawater or saline aquifers is the most recent one. However, current solid-state membranes are limited, which calls for the development of novel formulations for new membranes offering both high permeability (ion and water flux) and ion differentiation (selectivity) that are usually considered antagonist features. We report on the strategic development of hybrid nanoporous membranes made of a solid-state track-etched polymeric thin film and graphene oxide as supports in which biological ion channel such as Gramicidin A, alpha-hemolysin and ion selective binding peptide motifs are confined, respectively. These bioinspired and biomimetic solid-state membranes are attracting widespread attention since they offer several advantages including mechanical robustness, scalable, controlled pore dimension and shape, modifiable surfaces for desired function and energy-efficiency, for water sustainability. The permeability and selective ion transport will be evaluated via ion diffusion kinetics, UV-Vis absorption spectroscopy and nanofiltration while gaining insights into the role of key performance parameters including track-etch pore size, surface chemistry, and ion binding through nanochannels for water purification. The proposed activity positively impacts the environment by integrating ecofriendly materials design, development and deployment.

The ZrB₂ and HfB₂ materials are promising for application in hypersonic aerospace, cutting tools, metallurgy, microelectronics and refractory industries. The structure and properties of sintered under high pressure (4GPa) - high temperature (1800 ^oC) or HP-HT conditions ZrB₂, HfB₂, ZrB₂+30%TiB₂ and ZrB₂-20% SiC refractory materials are under consideration. HP-HT sintered HfB₂ (a=0.3141, c=0.3473 nm γ=10.42 g/cm³) demonstrated hardness HV(9.8 N)=21.27±0.84 GPa, HV(49 N)=19.29±1.34 GPa, and HV(98 N)=19.17±0.5 GPa and fracture toughness K1C(9.8 N)=6.47 MN×m0.5. High pressure sintered ZrB₂ (a=0.3167 , c=0.3528 nm, γ=6.1 g/cm³) demonstrated HV(9.8N)= 17.66±0.60 GPa, HV(49 N)= 15.25±1.22 GPa, and HV(98 N)= 15.32±0.36 GPa and K1C(9.8 N)=3.64 MN×m0.5. Addition of 30 wt.% of TiB₂ to ZrB₂ did not allow to increase hardness of the material essentially (HV(9.8 N)=17.75±2.36 GPa, γ=5.29 g/cm³ ). Addition of 20 wt.% of SiC to ZrB₂ and sintering under high pressure allowed essential increase of hardness to HV(9.8 N)=24.18±0.7 GPa, HV(49 N)=16.68±0.5 GPa, and HV(98 N)=17.59±0.4 GPa and fracture toughness (K1C(9.8 N)=6.49 ± 0.25 MN×m^0.5, K1C(49 N)=7.06± 1.55 MN×m^0.5 , K1C(98 N)=6.18± 1.24 MN×m^0.5) of composite ZrB₂- SiC material (γ=5.03 g/cm³).

Nickel based single crystal superalloys have been widely used for blades and vanes of the aeroengine hardware [1, 2, 3]. The main goal of these alloys is to provide high temperature strength owing to its γ-Ni/γ’-Ni3Al structure under aggressive working environment [1, 2, 3]. However, alloying elements used do not provide desired oxidation resistance to the components [1]. In order to provide optimum oxidation resistance and improve engine working efficiency, a system of the coating is applied which is commonly known as thermal barrier coating (TBC) system [1, 2, 3]. In general, TBC system comprises of two layers i.e. ceramic topcoat (TC) and an underlying metallic layer as a bond coat (BC). However, there is one additional layer between BC and TC grown either during service or manufacturing is known as thermally grown oxide (TGO) i.e., Al2O3. One of the crucial parts of the TBC system is the nickel aluminides (βNiAl) layer that is used as BC material [4, 5]. Most often, such a layer governs the TC life in the absence of foreign object damage [2]. For example, various modes of the failures are reported in literature such rumpling, stress and interdiffusion [1,2,5]. In this work, bond coat and associated trends are highlighted in the light of experimental observations.

Sustainable development is a comprehensive and complex system of systems requiring multidisciplinary and interdisciplinary science and technology inputs with economic, environment and social objectives. The trade space is very wide, and the multitude of trade-offs generate considerable challenges and make it often difficult to achieve an effective balance. During the last sixty years the planet’s population has grown exponentially, from 2.5 to 7.5 billion people, and the technological progress achieved has been tremendous, especially in the industrialized countries. These trends are expected to continue, even at faster rates. All these associated technological activities in the pursuit of better living standards have created a considerable depletion of resources and pollution of land, water and air. Thus, and because most of our resources are limited, it is imperative that we achieve more with less. In broad terms, sustainable development is achieved when the present needs and challenges are met without placing in jeopardy the ability of future generations to meet their own needs and challenges. The global energy demand is expected to increase exponentially, associated with the increase in the global population. The three main reserves of fossil fuels: oil, natural gas and coal are decreasing very rapidly and will not always be available to meet the global demands soon. The continuation of fossil fuel emissions will be environmentally deleterious, and there is already a need to remediate some of the deleterious effects already sustained by the environment. Energy security has become a major and critical issue as fossil fuels are confined to a few areas in the world and their availability is controlled by political, economic and ecological factors. This means that in a short term, considerable energy efficiencies and savings must be achieved, and alternative and renewable sources of energy must be developed. To enable all these technologies considerable advances in energy storage and conversion materials and technologies such as batteries, super capacitors and fuel cells must be achieved. The transportation industry has by far the largest share of global oil consumption and is now the major producer of global greenhouse gas emissions in most industrialized countries. Mobility projections show that it is expected to triple by 2050 with associated energy use and environmental impact. Considerable achievements have recently been obtained in the development of new and advanced materials such as light weight metallic alloys, metal matrix composites, intermetallic and carbon fiber composites and hybrid materials. Nano, nano-structured and nano-hybrid materials systems and nanotechnologies have also been deployed with significant impact. In addition, component redesign using a materials and functional systems integration approach is being used resulting in considerable system improvements and energy efficiency. This resulted in their introduction in the energy, transportation and manufacturing industries in a wide variety of devices and components with considerable technological, economic, environment and social impact:
Key Words: Transformative materials and technologies, nano, nanostructured and nanohybrid material systems, energy systems and challenges, environment degradation, sustainability domains and systems..

The structural, electronic and mechanical properties of RuB_x(x=1,2,3) are investigated by performing first principles calculations using density functional theory (DFT). The calculated lattice constants agree well with the available results. The chemical bonding is interpreted by calculating the electron localization function (ELF). The covalent Ru-B bond and B-B bond become stronger with the increase of boron’s concentrations, which can help improve the hardness of RuB_x system. Moreover, RuB has the highest bulk modulus, which means more prominent volume-compression resistance. RuB₂ has a certain elastic anisotropy and RuB₃ has the best toughness.

The demand for lithium is rapidly increasing with the production of lithium-ion batteries. Today’s lithium is produced from brine or ore [1]. The challenges of the former are long process time and large environmental burdens. The latter challenge is the high cost for high purity [2-3]. We have investigated lithium recovery by electrodialysis using a lithium ion conductive solid electrolyte La_0.57Li_0.29TiO₃ (LLTO). When this recovery is performed in a batch system, the lithium ion concentration of the solution changes as the recovery of lithium proceeds. To increase the energy efficiency of recovery, the effects of various factors should be elucidated and optimized. In this study, we investigated the effect of lithium ion concentration in the secondary solution on lithium recovery rate by electrodialysis using LLTO.
An anode (primary side) and a cathode (secondary side) electrodes were prepared on the surface of LLTO using a platinum paste. A reference electrode was also formed on each surface. Electrodialysis was performed by applying a DC voltage of 2.0 V between the anode and the cathode. The electrochemical impedance was measured by a 2-terminal method and a 3-terminal method using a reference electrode. The primary side solution was a 1.0 M aqueous lithium hydroxide solution. The secondary side solution was pure water or an aqueous lithium hydroxide solution having a concentration of 10^-3-1.0 M. The amount of transferred lithium was estimated by Faraday's law using the current value.
The lithium transfer rate reached a maximum when the lithium concentration in the secondary solution was 10^-2M. It was confirmed that the electrolyte impedance near the secondary surface of the electrolyte decreased with increasing lithium concentration. Beacause the same impedance was obtained in the OCV state and at 2 V, the decrease in the electrolyte resistance can be attributed to the increase in the pH of the solution.

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