The journal is a book of abstracts of the international conference "Japan- Mediterranean XII International Workshop on Applied Electromagnetic Engineering in Magnetic, Superconducting, Multifunctional and Nano Materials".
EXPLOSION SYNTHESES OF HIGH ENTROPY ALLOYS IN FE-W-AL-TI-NI–B-C SYSTEM
Copyright (c) 2023 Book of Abstracts JAPMED
PREPARATION OF CORRUGATED TUBES FOR HIGH EFFICIENCY HEAT EXCHANGERS BY EXPLOSIVE TUBE FORMING
HIGH QUALITY SPLICES OF SUPERCONDUCTORS
ALGORITHMIC FOUNDATIONS OF OPTIMIZATION USING FINITE ELEMENT MODELING OF HIGH-SPEED GRINDING TECHNOLOGY IN APPLICATION TO 3D MICRO-LEVEL MODELS
Optimization consists in choosing the best of all possible options for implementing high-speed grinding technology. A complete enumeration of all options may turn out to be inefficient or practically impossible. Therefore, to solve such a problem, we should apply fundamental mathematical results and numerical methods of optimization theory, which allow choosing the best option without directly checking all possible solutions. Such a choice is realized by means of calculations carried out using special algorithms and is practically impossible without the use of computer technology.
COMPUTER SIMULATIONS OF STATIC STRESS-STRAIN STATES FOR LONG-LENGTH PRESSURISED PIPES WITH EXTERNAL PROTECTIVE THIN NANOENGINEERED COATING UNDER NONUNIFORM TEMPERATURE FIELDS
Influence of nonhomogeneous temperature fields on the stress-strain state of the pressurized pipes is due to temperature dependencies of the structural material properties like Young's module, Poisson's ratio and linear expansion coefficient, so that the nonuniform temperature fields leads to the inhomogeneous of the material properties. It is proposed to use the differential equations formulated through the displacement and the stresses to consider the stress-strain state for axisymmetric long-length pipes with external protective thin nanoengineered coating taking into account the nonuniform temperature fields. The finite differences are used to make the computer simulations of the pipes with the external protective thin nanoengineered coating, and the cladding of nuclear fuel rods made from the Zr-based alloy with the thin protective coating made from the stainless steel is considered as the example. It is shown that consideration of structural material properties temperature dependencies can have the noticeable influence on the stress-strain-state estimations for the pressurized pipes with external protective thin nanoengineered coating under nonuniform temperature fields.
ADVANCED MANUFACTURING: PRINCIPLES AND INDUSTRIAL SUSTAINABLE TRENDS
Some trends and developments in the important engineering topic from industrial, research and academic point of view: advanced manufacturing of advanced materials from macro- to nanoscale subjected to static, low speed / high speed / hypervelocity impact and shock loading, with sustainable industrial applications to net-shape manufacturing, bioengineering, transport, energy and environment, defense and safety, an outcome of the very extensive, over 55 years, work on these scientific and industrial areas performed by the author and his research international team, are briefly outlined in the present Plenary Lecture of the 12th Japanese / Mediterranean Joint Workshop on Applied Electromagnetic Engineering for Magnetic, Superconducting, Multifunctional and Nanomaterials, JAPMED’12, held in Batumi, Georgia on July 2023. The topics considered may be listed as: • Mechanics (Structural plasticity, Low / High speed impact loading, Hypervelocity impact, Shockwaves loading) • Precision / Ultraprecision manufacturing from macro-, micro- to nanoscale (Metal forming, Metal removal processing, Surface engineering / Wear, Non-conventional techniques) • Nanotechnology / Nanomaterials manufacturing • Ferrous and non-ferrous materials (Metals, Ceramics, Superhard, Polymers, Composites, Multifunctional), from macro- to nanoscale (Nanostructured materials, Nanoparticles, Nanocomposites) • Powder production and processing technologies (High strain-rate phenomena and treatment under shock: Explosives, Electromagnetics, High temperature / high pressure techniques) • Biomechanics / Biomedical engineering • Transport / Crashworthiness of Vehicles: Passive and active safety for passengers and cargo (Surface transport: Automotive, Railway; Aeronautics: Aircraft, Helicopters) • Energy (Superconductors, Semiconductors, Electromagnetics, Solar cells, Photovoltaics, Nuclear reactors) • Environmental aspects (Impact on climate change: Nanotechnology; Automotive industry; Aeronautics industry) • Safety (Detection of explosives and hazardous materials) • Defense (Ballistics, Projectiles hitting targets, Shock loading) • Industrial sustainability
INTEGRATING IOT INTO AGRICULTURAL OPERATIONS TOWARDS THE INDUSTRY 4.0 AND SUSTAINABILITY
Industry 4.0 is a trend that is expected to have major impact on the transformation of all industrial sectors. Since agriculture is probably the most essential sector of the primary industry, facing the challenge of ensuring food security with regard to sustainability, it is significant to integrate the technological advancements that emerged in the context of Industry 4.0 within the agricultural operations. This paper presents an approach of facilitating agricultural operations by employing an IoT based system, capable of delivering a variety of operational services.
DEVELOPMENT AND CHARACTERISTICS OF METAL-POLYMER LAMINATES
For the last 20 years, research about impact-resistant polymeric materials is going intensively. The issue is a modern actual scientific and technical problem. Such material includes Metal-Polymer laminates. Metal-Polymer laminates are hybrid composite materials that consist of conventional fiber reinforced plastics with the addition of a metal component, typically a foil or mesh layers. While a range of potential advantages and applications have been discussed for such materials, the primary application to date has been for aircraft structures. Nowadays, laminates find its use in construction. Aim of Research is developing of metal-polymer laminate type materials with improved mechanical properties which will have a wide range of applications. Such kind of materials were obtained by the scientists at the Grigol Tsulukidze Mining Institute. In terms of the development of polymer chemistry, it is possible to produce such composites with targeted properties and use of synthetic fiber reinforced materials, that would satisfy wide–specter exploitation conditions, namely, the conditions of dynamic loads on material. The advantage of the proposed technology for making metal-polymer laminate compared to other technologies are lower costs of electricity (30-40% less), the possibility of receiving large-sized products/details and 40-50% lower cost of labor.
ZrO2 NANOPOWDERS AS FILLERS OF EPOXY POLYMERS
ON THE CONVERGENCE OF THE SOLUTION OF SCHRODINGER EQUATION FOR FINITE DIFFERENCE METHOD
In the present paper we investigate the convergence of solution of the Schrodinger equation for potential energy of particular conditions. The issue is crucial for application of numerical techniques, such as finite difference method.
We developed the method of solving the Schrodinger equation for multi-step quantum well, with arbitrary step number. The solution very useful for modeling of semiconductor hetero-structures of varying composition.
MODELING AND OPTIMIZATION OF PROPERTIES OF GA2O3-BASED QUANTUM STRUCTURES IN ORDER TO ACHIEVE HOLE CONDUCTIVITY
In this project, we investigate the properties of Ga2O3-based quantum structure with the aim of improving hole conductivity in the oxide. Ga2O3 is a promising material for electronic and optoelectronic applications due to its ultra-wide band gap and high breakdown voltage. However, its low hole mobility and concentration limit its performance in some applications. Recent studies have shown that Ga2O3 thin films can exhibit surface p-type conductivity under certain growth conditions. In this work, we use the finite-element method to model the electronic properties of Ga2O3 quantum well with triangular potential barrier. Our results provide insights into the design and optimization of Ga2O3-based quantum structures for improved hole conductivity in the oxide.
PROPOSAL OF A 3-D STEREOLITHOGRAPHY SYSTEM INCORPORATING MAGNETIC LEVITATION TECHNIQUE
This paper proposes a novel stereolithography (SLA) system for forming designed models by photocuring and stacking magnetically levitated special fluid. A drawback of stereolithography, one of the 3-dimensional printing techniques, is the post-processing of burrs and wasted support materials. The proposed method repeats photocuring while magnetically levitating magnetic photocurable resin (mPCR) fluid. Therefore, burrs and support materials are unnecessary, saving both time and money. The system has two main structural requirements; one is to generate an upward attractive force so that the mPCR fluid and its formed object do not droop under gravity, and the other is to irradiate the laser beam while reliably tracking the apex of the mPCR fluid cone that is magnetically supported and manipulated. This paper briefly introduces the prototype machine, designed to align a laser beam path, the controlled electromagnet with a through-hole, and the apex of magnetically levitated mPCR fluid.
TO THE PROPERTIES OF LASER-INDUCED PLASMA
Laser-induced breakdown spectroscopy (LIBS) is an analytical technique that uses a laser-induced plasma to perform elemental analysis of a sample. It is a versatile and non-destructive method that can be applied to various materials, including solids, liquids, and gases.
CREATION 3D FLUORESCENCE SPECTRA OF WINE
Our research provides for the analysis of different types of Georgian wine based on 3D fluorescence spectroscopy (3DF) using the Black Comet (200-950 nm) spectrometer manufactured by StellarNet. In this method, the 3D fluorescence signal is divided into a fixed number of statistical components. For each type of wine, a 3D database is strictly defined, which we conventionally call references. The etalon describe the excitation/emission spectra in detail. The advantage of the 3DF method compared to other statistical methods, such as peak component analysis (PCA), lies in the uniqueness of the unfolding of the spectra. The fluorescence spectra of the wine will be further analyzed by peak component analysis (PCA). After performing the PCA analysis, in order to reduce the number of tolerant etalon, we used the tolerant etalon sample (TES) comparison analysis, thus determining how tolerant the researched wine sample is to this or that specific etalon.
STRUCTURAL PROPERTIES OF III-NITRIDES RECEIVED BY UV STIMULATED TECHNOLOGY
In terms of structural studies, X-ray diffraction (XRD) studies are discussed in this paper. Based on the experimental results, X-ray diffraction graphs of III nitrides obtained with and without UV irradiation are shown and is evaluated the role of UV stimulation in magnetron sputtering technology.
SMART ENERGY MANAGEMENT IN THE CONTEXT OF INDUSTRY 4.0
In view of the energy crisis, which is also strongly affected by recent geopolitical developments, energy security and sustainability are more significant than ever. To this end, the Industry 4.0 approach along with cutting-edge technological trends which advance in its context are expected to transform energy management for energy consumption in more efficient and sustainable ways. This paper overviews these Industry 4.0 technological trends which can enable smart energy management and identifies some of the corresponding challenges regarding this issue.
ON THE EFFECTIVE DIELECTRIC PERMITTIVITY OF NANOCOMPOSITE STRUCTURES
REDUCTION OF IRON LOSS ON LAMINATED STATOR CORES BY SECONDARY CURRENT HEATING METHOD
In this paper, the “secondary current heating method,” which has been proposed in the previous reports, was used to heat-treat the laminated stator cores of actual motors to reduce iron loss. To evaluate the magnetic properties of the laminated stator cores including the teeth, an inner core was installed inside the stator to form a closed magnetic path. The air gap between the stator and the inner core causes the B-H loops to be tilted compared to the one of the back yoke, though, it was found that the iron loss was reduced by about 30% in the laminated stator core after heat treatment.
MAGNETIC SHIELDING MATERIALS FOR ELECTRIC VEHICLES
In this paper, the classic low carbon steel used as structural part of the bottom part of the car is tested to additionally become operational part of the electric vehicles as the magnetic shielding material after magnetothermal annealing. The low carbon steels (LCS) were studied in their as-received form and after thermal annealing in 350oC for 1 hour in inert atmosphere with a consequent slow cooling for 24 hours, followed by magnetic annealing in 350oC for 1 hour in inert atmosphere under 0.1T field, followed by slow cooling for 24 hours under the presence of the applied field. A typical change in the differential magnetic permeability of LCS after the annealing process increased up to 200,000. In the meantime, hardness tests illustrated a negligible change (decrease) of mechanical stiffness. Apart from that, the magnetic anisotropy of welded samples has been determined by monitoring the permeability in different in-plane axes, since these steel sheets are to undergo a welding process during manufacturing. The study of the samples with TEM (JEOL operating at 220 kV) was done to monitor the disorder structures created in LCS before and after magneto-thermal treatment. Indeed, a remarkable decrease in dislocation density was observed, thus correlating the increase of permeability with the microstructure enhancement.
OPTIMIZING QE OF CCD BY MODIFYING BLACKCOMET DETECTOR
Charge-Coupled Device (CCD) is a type of image sensor technology used in digital cameras, video cameras, and various scientific and industrial applications to capture and convert light into electronic signals. Such sensors offer several advantages, including high sensitivity to light, low noise levels, and good image quality with high dynamic range. They are commonly used in applications that require precise and high-quality imaging, such as astronomy, microscopy, and spectroscopy. However, there are many ways to improve and optimize the role of CCD sensors in spectroscopy, and this could have a significant impact on the sensitivity, safety, and accuracy of measurements.
INFLUENCE OF SURFACE ROUGHNESS ON THE AMPLITUDE OF GIANT MAGNETORESISTANCE EFFECT IN MULTILAYERED THIN FILMS
BULK MGB2 AND MT-YBCO FOR SUPERCONDUCTING BEARINGS WORKING IN LIQUID HYDROGEN
PRODUCTION OF HOMOGENEOUS COMPOSITE PRESS-POWDERS BASED ON ZRB2 AND SIC FOR UHTCS
The aim of the research was to obtain superfine homogeneous composite powders, which, due to their unique composition and morphology, will be used to obtain ceramics with improved properties for the thermal protection of supersonic aircraft. The novelty of research was microstructure refining methods, selection of sintering additives/dopants and their combining action. As regards sintering additives and dopants, B4C and graphite powder, carbon black and graphene structures were used. The use of the latter individually and in combination sintering additives was one of the innovations of the research.
FUNCTIONAL SUPERCONDUCTOR-FERROMAGNET NANOSTRUCTURES FOR SUPERCONDUCTING ELECTRONICS
The work is devoted to the study of the processes of formation and analysis of the parameters of a functional nanostructure - a superconducting spin valve, which is a multilayer structure consisting of ferromagnetic cobalt nanofilms separated by niobium superconductor films. The studies were carried out using molecular dynamics simulations and vacuum deposition of the modelled nanostructures. The atomic structure of individual nanolayers of the system is considered. Particular attention is paid to the analysis of the atomic structure of the contact regions, since the quality of the interface between the layers plays a decisive role in creating of a microelectronic devices. The obtained results can be used both in the development and optimization of technologies for the formation of spin valves and other functional elements of spintronics.
THE CONCEPT OF OBTAINING SPINETRONIC NANOSTRUCTURES FOR QUANTUM DEVICES
The aim of the paper is elaboration of concept for obtaining spintronic nanostructures and quantum devices by Laser Plasma technology of 2D materials preparation.
BARIUM TITANATE BASED ACOUSTIC SENSING ELEMENTS
Materials with the ability to generate voltage when subjected to mechanical stress, such as PZT and BaTiO3 are used in various applications such as supercapacitors, dielectrics ceramics and catalysts. Barium titanate (BaTiO3) possesses various advantageous properties in terms of its structure, piezoelectricity and ferroelectricity. Yet, to further enhance these properties, barium was substituted with strontium using both sintering and sol-gel methods. Barium strontium titanate (BST) ferroelectric materials have attracted significant interest due to their chemical stability, high permittivity, excellent tunability and minimal dielectric losses. This study demonstrates the synthesis of perovskite BaxSr(1-x)TiO3 materials, with varying strontium content ranging from 0% to 50%, using the sintering and the sol-gel processes. In addition, the samples were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), differential thermal analysis (DTA) and thermogravimetry analysis (TGA).
EXPERIMENTAL DEVICE FOR 2D MATERIALS PREPARATION BY LASER-PLASMA METHOD
THERMAL CONDUCTION AND MAGNETIC PROPERTIES OF MAGNETORHEOLOGICAL ELASTOMERS DISPERSING SENDUST PARTICLES
A new magnetic functional material that is an elastomer dispersing micrometer-size sendust particles has been developed in this study. Sendust is a material which is the alloy composed of Fe, Si and Al, and has a high initial magnetic permeability and small hysteresis. Thermal conductivity of this new magnetic functional material was investigated by using the steady-state parallel-plate method while the magnetic properties of the materials were evaluated by using the BH analyzer.
RHEOLOGICAL PROPERTIES OF THIN-FILM PERMANENT MAGNET ELASTOMERS IN STRETCH DEFORMATION
Permanent magnet elastomers are three-dimensional deformable permanent magnets, which are novel functional materials in which the magnetic field around the elastomer changes during deformation. The detection of the magnetic field variation enables the realization of tactile sensors. Considering the application of tactile sensors, it is important to understand their viscoelastic properties. In the present study, the rheological properties of permanent magnet elastomers in stretch deformation were investigated. The results show that the viscoelasticity changes due to magnetization. Additionally, this variation due to magnetization was discussed by fitting it into a four-element mechanical model.
ALTERNATIVE DESIGN OF A HIGH TORQUE DENSITY TWO-PHASE BRUSHLESS DIRECT CURRENT MOTOR
This paper proposes a design of a high torque density dual-stator brushless direct current (BLDC) motor. BLDC motors are known for their high torque capacity and power density characteristics, and therefore, they have many applications. The proposed BLDC motor is a two-phase motor with two stators, and each stator excited by one phase. The duty cycle of inverter switches is complete and coils are continuously excited. So, due to the full and uninterrupted use of all coils and core, the motor has a higher torque density compared to other BLDCs. The mathematical model of the motor provides a better understanding of motor performance. The performance of the designed motor is analyzed using finite element analysis.
FUNDAMENTAL STUDY OF HAPTIC SENSOR UTILIZING MAGNETIC COMPOUND FLUID RUBBER SENSOR FOR INVESTIGATION OF NUCLEAR FACILITIES
Humanoid robots are expectable in a nuclear facility for their manipulation and operation in a nuclear power plant. Therefore, it is necessary to develop a haptic sensor can be adapted to radiation environment. Recently, we have been developed haptic sensor utilizing functional fluids involving MCF (Magnetic Compound Fluid) for artificial skin. Magnetic Compound Fluid (MCF) rubber is a new smart sensor obtained by mixing rubber with MCF. In this study, we clarify the adapatability of tactile function of MCF rubber for investigation of nuclear facilities.
EXPERIMENTAL STUDY ON SEALING PERFORMANCE AND FLOW CHARACTERISTICS OF MAGNETIC FLUID IN EXTREMELY TINY CLEARANCE UNDER MAGNETIC FIELD
Sealing performance and flow characteristics of magnetic fluid in extremely tiny clearance less than 30 μm under magnetic field are investigated experimentally. The extremely tiny clearance in the test section is set to 5, 10, 15, 20 and 30 μm, and magnetic field is applied to magnetic fluid flow at this clearance. The results show that maximum of 1.2 MPa of pressure resistance was obtained at 5 μm of tiny clearance from the sealing test and the relationship among frictional coefficient, magnetic field and Re is quite different between 5 and 30 μm of tiny clearance from the flow characteristic test.
EFFECT OF NANOADDITIVES ON THE PROPERTIES OF PARTIALLY STABILIZED ZIRCONIA
EFFECT OF CRB2 REINFORCEMENT ON THE MECHANICAL PROPERTIES OF CERAMIC MATRIX COMPOSITES (CMCS) AND METAL MATRIX COMPOSITES (MMCS)
PECULIARITIES OF OBTAINING NANOSTRUCTURED MATERIALS COMPACTED BY THE METHOD OF HOT PRESSING DUE TO THE PASSAGE OF DIRECT ELECTRIC CURRENT
The aim of this work was to study the regularities of structure formation in composites based on zirconium dioxide nanopowders in the process of hot pressing with direct alternating current. . It was found that the microstructure of the samples in which zirconium dioxide was obtained in different ways strongly depends on tetragonal-monoclinic transitions. Optimal composition of initial mixtures and sintering modes using alumina nano additives was established in order to improve the physical and mechanical properties of the material. To improve the mechanical properties of the samples, sintering temperature and holding time can be raised because alumina grain growth is less rapid at a 30 % content than at lower contents.
2D LAYERS OF MOS2 GROWN BY THE METHOD OF PULSED LASER DEPOSITION ON GLASS AND POLYIMIDE SUBSTRATES
We presents the results of the synthesis and studies of the properties of Mos2 monolayer and multilayer films deposited by pulsed laser deposition on glass and flexible polyimide substrates. Atomic force microscopy (AFM), X-ray diffractometry, Raman scattering spectroscopy, optical absorption, photoluminescence and Hall measurements used to characterize the structural, morphological, optical and electrical properties of the films confirm the correlation between the strain effects and properties of the films appearing due to the large mismatch between thermal expansion coefficients (TEC) of the substrate and ultrathin Mos2 layers.
AN INFORMATION-THEORETICAL ANALYSIS OF THE SPIRIT OF THE AGE
The expression "spirit of the age" first seems to have been used by Arndt in his book published in 1805. This was little more than a series of sketches of nations and personalities, a format more or less repeated in Hazlitt's work of the same title published in 1825. The concept acquired greater importance with the emergence of Tolstoy's theory of history, of which the main exposition is his work War and Peace (published in 1868), according to which events reflect the general "will of the people" rather than actions by prominent individuals. This "will of the people" would appear to correspond with the spirit of the age. It has also had a great bearing of the development of science. It has been aptly remarked by Lecky that the success of any opinion depends much less upon the force of its arguments, or upon the ability of its advocates, than upon the predisposition of society to receive it. The emergence of the theory of evolution provides a classic example of this phenomenon. The matter clearly merits deeper investigation. Although Tolstoy makes eloquent arguments in favour of his theory, it contains no real mechanism for understanding how the spirit develops — as it evidently does — and hence it is of little use for making predictions. Of particular value would be a prediction of whether a certain new theory would be received by society. This contribution attempts to use the method of physical analogies to better understand the spirit of the age. Furthermore, the very recent development of large language models provide an unprecedented ability to efficiently capture the spirit of our age in different cultural spheres, thereby providing data more amenable to calculation than what was previously available. The main idea developed in this contribution is that the "noise" of the almost infinitesimal array of actions of the individual denizens of Earth can, sometimes, be amplified up to macroscopic expression.
HEALTH HAZARDS AND POLLUTION RISK FROM LARGE BATTERY ENERGY STORAGE SYSTEMS
Energy storage systems are deployed to decrease the costs and improve the dependability of a power supply, especially electricity generation. Conventional generating stations (hydroelectric or powered by fossil fuels) tend to work continuously at the same rate, whereas demand fluctuates. On the other hand novel "renewable" sources such as wind turbines fluctuate more than demand. In both cases it is useful to store electricity when there is a surplus, and release it when there is a shortage. In the case of hydroelectricity, the same infrastructure can be used for this purpose — surplus power is used to pump water back up into the reservoir. Most other sources require special infrastructure. For example, surplus power can be used to split water into hydrogen and oxygen by electrolysis; the hydrogen is stored and can later be used as fuel to power a generating station. The drawback is not only the expense of the infrastructure but also the significant exergy losses during the process. Hence the attraction of "battery" storage, by which is meant electrochemical cells such as those based on nickel–manganese–cobalt, vanadium, sodium or lithium. The enormous worldwide increase in the number of electric automobiles has provided a strong impetus for developing such "batteries", especially the lithium ion type, and large batteries of such batteries can be used to store energy on a scale commensurate with the requirements of a countrywide electricity grid. Since intermittency of supply is of particular problem with the so-called "green" or renewable sources, governments have provided subsidies for energy storage, typically by selling surplus electricity very cheaply. This has encouraged the construction of battery energy storage systems (BESS), for which a business case can be made because of the price differential of electricity between times of surplus and scarcity, regardless of whether the surplus electricity actually comes from a renewable source. Nevertheless, these installations are not hazard-free. Those based on lithium ions, in particular, are susceptible to overheating ("thermal runaway"). In a dense array typical of BESS, fire can percolate from one battery to another and a major conflagration, possibly accompanied by explosions, can result. This in turn implies release of toxic contaminants to the air and to groundwater. This contribution assesses the hazards and risks of such incidents.
ANALYSIS OF POSSIBILITIES THE CURRENT SITUATION FOR USING AND ACCUMULATING GREEN ENERGIES IN GEORGIA
The present paper is dedicated to addressing the challenge of efficiently accumulating energy generated by solar modules and wind farms—a significant international issue that currently requires substantial financial investment. The paper emphasizes the feasibility of implementing this concept in countries equipped with operational hydroelectric power plants with dams. Such a strategy presents a cost-effective and efficient means of energy storage for these renewable sources. Furthermore, the paper delves into the potential for enhancing the energy efficiency of wind farms and solar panels through a comprehensive analysis of their structural design and component characteristics.
DISCOVERING THE CAUSE OF AEROTOXIC SYNDROME: A CAUSAL CALCULUS APPROACH
Aerotoxic syndrome (AS) is a collection of symptoms of ill health experienced by pilots, cabin crew and passengers, especially frequent flyers, after a journey in a jet airliner. The syndrome is especially, but not exclusively, associated with the occurrence of "fume events", in which cockpit and cabin are filled with smoke. The problem started to arise when large aircraft interiors began to be heated and pressurized using air bled off from the main engines. Some of the symptoms are consistent with inhalation neurotoxicity due to compounds either present in fresh lubricating oil or as decomposition products resulting from the harsh environment of the engine oil. The seals separating the oil from the air invariably leak to a greater or lesser extent, depending on design and maintenance history, and the idea that AS is due to contamination of cockpit and cabin air by traces of engine oil has emerged. The matter is currently much debated and there are increasing attempts to better understand the origin of AS. The classic Bradford Hill criteria of medical causation have been applied, but rather inconclusively. Very recently, however, significant advances in developing the calculus of causality have been made. This contribution makes use of these advances to gain deeper understanding of the origins of AS.
AN OVERVIEW OF LIFE CYCLE ASSESSMENT CRITERIA FOR TRANSPORTATION DECISION-MAKING
MAGNETIC FIELD BETWEEN POLAR HEMISPHERES: REMARKS ON THE DISLOCATION OF ZONES OF A CONSTANT GRADIENT AND FORCE FACTOR
Abstract:To create an inhomogeneous magnetic field, in which there would be zones with a practically constant value of the magnetic gradient (MG) and / or magnetic force factor (MFF), an original solution was indicated: the use of an electromagnetic system with spherical poles. In this case, the coordinate dependences of MG and MFF in the interpolar region are extreme and the zones localized in the domain of the extrema are practically stable, referred to as the MGConst and MFFConst zones, with individual coordinates xextr of their conditional centers and length Δx (with an allowable error changes in MG and MFF data within these zones). The data following from experimental studies is given on the dislocation of the indicated zones between the poles-hemispheres of diameter D, separated by different distances b; the values of xextr/D and Δx/D depend on b/D. It is shown that the dependencies xextr/D on b/D obtained separately for the MGConst and MFFConst zones, demonstrating, like the dependencies Δx/D on b/D, mutual similarity (up to a constant multiplier), obey power functions with exponents of 0.5 and 0.4, respectively. A closer (to the center-to-center line of pole-hemispheres) and more compact (in length) dislocation of the MFFConst zones compared to the MGConst zones was revealed: almost 1.3 times both in xextr/D and in Δx/D.
FEATURES OF MAGNETIZATION OF FERROMAGNETIC COMPOSITES: ROLE OF GRAIN CHAINS ON AN EXAMPLE OF GRANULATED MEDIA
The purpose of the article is to develop a model of chain-by-chain magnetization of granular media, in which chains of granules are basic elements. When a granular medium is magnetized, such as when consisting of ferromagnetic spheres, the chains of contacting granules (spheres) serve as self-sufficient conductors of the magnetic flux Φ. Each of these chains is characterized by a pronounced redistribution Φ in its cross section. If in the chain of spheres with radius R the conditional core with radius r is selected and for measurements Φ to surround its loop placed between the contacting spheres, then an increase in r decreases the thread density (magnetic induction B). According to Φ, detailed information on B in the cores and their magnetic permeability μ with the magnetization of the chains in the solenoid is obtained.
EXCITONS AND BIEXCITONS IN CYLINDRICAL NANOWIRES OF GROUP II-IV MATERIALS
A study of the trion and biexciton in a nanowire (NW) in the framework of the effective-mass model is presented. We consider the formation of trions and biexcitons under the action of both the lateral confinement and the localization potential. The analytical expressions for the binding energy and eigenfunctions of the trion and biexciton are obtained and expressed by means of matrix elements of the effective one-dimensional cusp-type Coulomb potentials whose parameters are determined self-consistently by employing eigenfunctions of the confined electron and hole states. Our calculations for the ZnO/ZnMgO, CdSe/ZnS and CdSe/CdS core/shell cylindrical shaped NWs show that the trion and biexciton binding energy in NWs are size-dependent and for the same input parameters the biexciton binding energyin NWs is always larger than the binding energy of the trion. The associative ionization of biexciton antibonding states into trion bonding states that leads to the formation of trions is studied. Based on the results for size dependence of biexciton binding energy and probability associative ionization an optimal radius for optoelectronic application NW is suggested.
CAN THE FORMATION OF COMPENSATING DONORS BE SUPPRESSED IN MODULATED P-DOPPED GALLIUM OXIDE QUANTUM WELLS?
The actual problem of obtaining hole conductivity in ultra-wide bandgap semiconductor Ga2O3 is considered. It is proposed to use Aa2O3/Ga2O3 quantum structures for increasing hole concentration, and their mobility. The dependence of theses parameters on system geometry and composition is studied.
MATERIALS AND DEVICES FOR SPIN-QUBIT QUANTUM COMPUTERS
The aim of the paper is elaboration of the concept for obtaining spintronic and spinqubit nanostructures applicable in quantum computing and quantum information technologies.