STAND FOR VEHICLES PASSIVE SAFETY RESEARCH

The issues concerning the research of vehicles passive safety are considered. The applied stand for on location tests is considered. The stand designed for investigations in the field of vehicles passive safety is offered

Alkaline electrochemical reduction of a magnesium ferrospinel into metallic iron for the valorisation of magnetite-based metallurgical waste

The electrochemical reduction of iron oxides in alkaline media arises as a novel approach for ironmaking and iron-rich waste valorisation. Strong advantages and attractive aspects of alkaline electroreduction include lower electric energy consumption, absence of CO2 emissions, and non-polluting valuable by-products such as H2 and O2. Another potential advantage originates from the compatibility of this concept with intermittent renewable energies. However, to bring this technology to a competitive level, especially compared to the traditional steelmaking, innovative approaches and developments in materials processing and their appropriate integration into the electrolysis process are required. This research work explores the prospects for electrochemical reduction of a magnesium-containing ferrospinel, as a potential component in iron-containing wastes. The experimental approach considers bulk cathode- and suspension-based electrolysis concepts, which allow reaching 55% and 20% Faradaic efficiencies of the reduction to metallic iron, respectively. The effects imposed by the magnesium presence on the electroreduction kinetics, phase composition and morphology of the electroreduction products are evaluated and discussed. The obtained results open new perspectives for the recovery of metallurgical residues with low magnesium impurities content.publishe

Prospects for electrical performance tuning in Ca3Co4O9 materials by metallic Fe and Ni particles additions

This work further explores the possibilities for designing the high-temperature electrical performance of the thermoelectric Ca3Co4O9 phase, by a composite approach involving separate metallic iron and nickel particles additions, and by employing two different sintering schemes, capable to promote the controlled interactions between the components, encouraged by our recent promising results obtained for similar cobalt additions. Iron and nickel were chosen because of their similarities with cobalt. The maximum power factor value of around 200 µWm−1K−2 at 925 K was achieved for the composite with the nominal nickel content of 3% vol., processed via the twostep sintering cycle, which provides the highest densification from this work. The effectiveness of the proposed approach was shown to be strongly dependent on the processing conditions and added amounts of metallic particles. Although the conventional one-step approach results in Feand Ni-containing composites with the major content of the thermoelectric Ca3Co4O9 phase, their electrical performance was found to be significantly lower than for the Co-containing analogue, due to the presence of less-conducting phases and excessive porosity. In contrast, the relatively high performance of the composite with a nominal nickel content of 3% vol. processed via a two-step approach is related to the specific microstructural features from this sample, including minimal porosity and the presence of the Ca2Co2O5 phase, which partially compensate the complete decomposition of the Ca3Co4O9 matrix. The obtained results demonstrate different pathways to tailor the phase composition of Ca3Co4O9 -based materials, with a corresponding impact on the thermoelectric performance, and highlight the necessity of more controllable approaches for the phase composition tuning, including lower amounts and different morphologies of the dispersed metallic phases.publishe

Photocatalytic removal of benzene over Ti3C2Tx MXene and TiO2–MXene composite materials under solar and NIR irradiation

MXenes, a family of two-dimensional (2D) transition metal carbides, nitrides and carbonitrides based on earth-abundant constituents, are prospective candidates for energy conversion applications, including photocatalysis. While the activity of individual MXenes towards various photocatalytic processes is still debatable, these materials were proved to be excellent co-catalysts, accelerating the charge separation and suppressing the exciton recombination. Titanium-containing MXenes are well compatible with the classical TiO2 photocatalyst. The TiO2 component can be directly grown on MXene sheets by in situ oxidation, representing a mainstream processing approach for such composites. In this study, an essentially different approach has been implemented: a series of TiO2-MXene composite materials with controlled composition and both reference end members were prepared, involving two different strategies for mixing sol-gel-derived TiO2 nanopowder with the Ti3C2Tx component, which was obtained by HF etching of self-propagating high-temperature synthesis products containing modified MAX phase Ti3C2Alz (z > 1) with nominal aluminium excess. The prospects of such composites for the degradation of organic pollutants under simulated solar light, using benzene as a model system, were demonstrated and analysed in combination with their structural, microstructural and optical properties. A notable photocatalytic activity of bare MXene under near infrared light was discovered, suggesting further prospects for light-to-energy harvesting spanning from UV-A to NIR and applications in biomedical imaging and sensors.publishe

MXene-containing composite electrodes for hydrogen evolution: material design aspects and approaches for electrode fabrication

This work explores the possibilities for the processing of Ni- and Ti3C2Tx (T = OH, O) MXene-containing composite electrodes, by co-pressing and plastic deformation or by etching of the electrodes prepared directly by self-propagation high-temperature synthesis (SHS). Various material design approaches were also explored. In order to tune the Ti3C2 interlayer distance in Ti3C2Al MAX phase, an introduction of additional Al to form Ti3C2Alz materials with z > 1 was attempted. Self-propagation high-temperature synthesis of powder mixtures with extra Ni and Al content (e.g. Ni:Ti:Al:C = 1:2:3:1) resulted in SHS products containing Ti3C2Alz z > 1 material and Ni–Al alloys. Further etching of these products in 10M NaOH allowed the direct formation of electrodes with active surface containing Ti3C2Tx (T = OH, O) MXene- and Raney nickel-containing composites. The electrochemical studies were focused on hydrogen evolution and showed the potential for boosting the electrochemical reaction in Ni and MXene-containing composite electrodes, especially at high current densities. The guidelines for the processing of such electrodes under fluorine-free conditions are proposed and discussed.publishe

Strontium titanate and zinc-oxide-based materials for high-temperature thermoelectric harvesting

Broad societal needs have focused increased attention to providing a sustainable energy supply to the population, based on technologies with minimal environmental impact and reduced fossil fuels usage. One solution is to improve energy conversion efficiency in key consuming sectors. Since most of the energy (60-70%) used worldwide is discharged as waste heat, ”green” thermoelectric (TE) conversion has received considerable attention due to its intrinsic simplicity, employing no moving parts, silent operation, excellent scalability and reliability, and self-sufficiency to enable mobile or remote applications. In some energy-conversion scenarios, the cost and thermal stability requirements may dominate over efficiency issues, making abundant, high-temperature-stable and low-toxic oxides an interesting alternative TE material. This talk will feature some oxide-specific approaches towards tuning the thermoelectric performance in strontium titanate and zincoxide-based materials, including defects engineering and in-situ induced nanostructuring.publishe

Quality of Graphite Target for Biological/Biomedical/Environmental Applications of 14C-Accelerator Mass Spectrometry

Catalytic graphitization for 14C-accelerator mass spectrometry (14C-AMS) produced various forms of elemental carbon. Our high-throughput Zn reduction method (C/Fe = 1:5, 500 °C, 3 h) produced the AMS target of graphite-coated iron powder (GCIP), a mix of nongraphitic carbon and Fe3C. Crystallinity of the AMS targets of GCIP (nongraphitic carbon) was increased to turbostratic carbon by raising the C/Fe ratio from 1:5 to 1:1 and the graphitization temperature from 500 to 585 °C. The AMS target of GCIP containing turbostratic carbon had a large isotopic fractionation and a low AMS ion current. The AMS target of GCIP containing turbostratic carbon also yielded less accurate/precise 14C-AMS measurements because of the lower graphitization yield and lower thermal conductivity that were caused by the higher C/Fe ratio of 1:1. On the other hand, the AMS target of GCIP containing nongraphitic carbon had higher graphitization yield and better thermal conductivity over the AMS target of GCIP containing turbostratic carbon due to optimal surface area provided by the iron powder. Finally, graphitization yield and thermal conductivity were stronger determinants (over graphite crystallinity) for accurate/precise/high-throughput biological, biomedical, and environmental14C-AMS applications such as absorption, distribution, metabolism, elimination (ADME), and physiologically based pharmacokinetics (PBPK) of nutrients, drugs, phytochemicals, and environmental chemicals

IMPROVING METHODS FOR MONITORING AND DIAGNOSING THE TECHNICAL CONDITION OF SELF-PROPELLED TRANSPORT AND TECHNOLOGICAL EQUIPMENT OF MINING ENTERPRISES

This article evaluates the current methods for monitoring the technical condition of imported self-propelled loading and delivery equipment, which is operated in real conditions of the mining industry. Comparative assessment of the performance of foreign self-propelled equipment should be evaluated by the indicator of Overall Equipment Effectiveness (OEE), which is evaluated depending on the availability, efficiency and quality of work of the LHD.The results of experimental and theoretical studies of the parameters of the interaction of the transport-technological system "self-propelled machine - mining environment" and bench tests of LHD parts allowed to state that the vast majority of downtime of self-propelled equipment due to equipment failures can be prevented by improving its system of maintenance and diagnosis. The components of the indicator of the overall effectiveness of self-propelled equipment are determined.Numerous failures of systems and parts are primarily due to the absence of monitoring schemes at mining enterprises that would allow operational control of the condition of self-propelled imported equipment. In this regard, it is necessary to obtain a database of the causes of failures of systems and parts, which can be considered as the basis for the development of methodological guidelines for the control and testing of the technical conditions of the LHD in real mining conditions.Based on the automated collection and processing of information about the technical condition of LHD and expert assessment of the resource indicators of units and parts according to the frequency of their failure, it has been established that currently diagnosing the technical condition of foreign-made self-propelled mining transport equipment is a complex integrated task requiring the development of relevant modern methods and measuring equipment with additional software

Feasibility study of the three-tether axisymmetric wave energy converter

There are numerous designs and concepts that have been offered to extract energy from ocean waves. A heaving buoy is distinguished as the most popular device which predominantly harnesses energy from the vertical motion in waves. One such device is the bottom-referenced submerged heaving buoy represented by the Carnegie Clean Energy CETO system. The total power absorption of this converter can be increased by replacing the single-tether power take-off system by a three-tether mooring configuration thereby making motion controllable in heave and surge. The current paper provides a comparative performance analysis of the generic submerged heaving buoy connected to one tether and the three-tether converter in terms of the buoy motion, and design of the power take-off and mooring systems. This is accompanied by a techno-economic analysis of two converters.N. Y. Sergiienko, A. Rafiee, B. S. Cazzolato, B. Dinga, M. Arjomandi

MODERN SYSTEMS OF ORGANIZATION OF DECISIONS ENFORCEMENT AND LEGAL STATUS OF EXECUTORS

The relevance of the study is as follows: if the substantive decision of a court or other jurisdiction (offi-cial) is subject to enforcement, the state must provide an effective mechanism for such kind of enforce-ment (otherwise, in case of non-compliance with the decision by the obligated person, protection of rights, freedoms, interests of the person will remain only on paper). An important component of such a mechanism is the system of enforcement of decisions. Therefore, each state faces the question of which system of enforcement of decisions to choose, and here we need the experience of other states that have already passed this path and can already clearly understand the results. The purpose of the article is to consider the experience of foreign states in reforming the system of enforcement of decisions and the legal status of executors in order to implement it in Ukraine. Methodological basis of the scientific arti-cle is general and special methods of scientific research (deductive, analytical, synthesis method, hermeneutic method, comparative, statistical, historical, dialectical and other methods), which were used to cover the topic of the scientific article. The results of the study contain a generalization of the experience of foreign countries in reforming the system of enforcement of decisions and the legal status of executors. The practical significance of the study is that the scientific article analyzes the application of different systems of organization of enforcement of court decisions, other bodies (officials), different approaches to the legal regulation of the legal status of executors. This can be useful for both legal scholars and legal practitioners, as well as anyone interested in reforming executive legislation