Structural Decomposition Research Articles

Decomposition of liquid-liquid extraction organic phase structure into critical and pre-peak contributions

Solution nanostructure induced by amphiphile self-association plays an important role in various chemical and physical processes, including liquid-liquid extraction (LLE). Small angle scattering techniques are an essential means of probing this structure, but, due to non-uniqueness of scattering patterns, their interpretation is not trivial. Here, we decompose small angle x-ray scattering (SAXS) patterns for a range of binary LLE organic phases into two components: Ornstein-Zernike and pre-peak contributions resulting from, respectively, critical concentration fluctuations and packing of the amphiphilic extractant molecules in the nonpolar aliphatic diluent. While we previously applied Ornstein-Zernike scattering models to similar organic phases, including the pre-peak explicitly in the fit allows us to measure weak fluctuations at high extractant concentration and simultaneously obtain information on the position and intensity of the correlation peak related to amphiphile packing. Scattering patterns and partial structure factors calculated from molecular dynamics simulations support this interpretation. We demonstrate how this minimal scattering model describes nanostructuring for a large number of extractant types over their entire extractant/diluent composition ranges, suggesting simple and universal behavior. The straightforward assignment of these structural contributions facilitates the comparison of these features between different classes of extractant molecules and will enable further studies of organic phase aggregation. Applicability to more complex, process-relevant organic phases is illustrated with post-contact organic phases containing significant quantities of extracted lanthanide nitrate salt, which we find are readily described by this model.

Analyzing long-term dynamics of agricultural greenhouse gas emissions in Austria, 1830–2018

Agriculture is an important contributor to greenhouse gas (GHG) emissions. While the development of agricultural GHG emissions on national and global scales is well studied for the last three to six decades, little is known about their trajectory and drivers over longer periods. In this article, we address this research gap by calculating and analyzing GHG emissions related to agriculture in Austria from 1830 to 2018. We calculate territorial emissions on an annual basis and include all GHG emissions from the processes directly involved in agricultural production. Based on this time series, we quantify the relative importance of major drivers of changes in GHG emissions across time and agricultural product categories, applying a structural decomposition analysis. We find that agricultural GHG emissions in Austria increased by 69 % over the total study period, from 4.6 Mt. CO2e/yr in 1830 to 7.7 Mt. CO2e/yr in 2018. While emissions increased only moderately from 1830 to 1945 (+22 % overall), with strong fluctuations between 1914 and 1945, they doubled from 1945 to 1985. In the most recent period from 1985 to 2018, emissions fell by one third, with decreases leveling off over time. Our decomposition analysis reveals that increases in agricultural production per capita most importantly contributed to the high growth in GHG emissions from 1945 to 1985. Conversely, decreasing emission intensities of products and a more climate friendly product mix were key drivers in the emissions reduction observed after 1985. We also contribute to the discussion around the global warming potential star (GWP*), by calculating GHG emissions based on this alternative metric, and contextualize our data within total socio-economic GHG emission trends. By providing insights into the historical trends and drivers of agricultural GHG emissions, our findings enhance the understanding of their long-term historical dynamics and adds to the knowledge base for future mitigation efforts.

From Herbert A. Simon’s legacy to the evolutionary artificial world with heterogeneous collective behaviors

This paper focuses on Herbert A. Simon’s visionary theory of the Artificial World. The artificial world evolves over time as a result of various actions, including interactions with the external world as well as interactions among its internal components. This paper proposes a mathematical theory of the conceptual framework of the artificial world. This goal requires the development of new mathematical tools, inspired in some way by statistical physics and stochastic game theory. The mathematical theory is applied in particular to the study of the dynamics of organizational learning, where cooperation and competition evolve through decomposition and recombination of organizational structures; the effectiveness of the evolutionary changes depends on the dynamic prevalence of cooperative over selfish behaviors, showing features common to the evolution of all living systems.

Twist decomposition of non-linear effects in Balitsky–Kovchegov evolution of proton structure functions

Effects of non-linear small-x evolution of the gluon distribution given by the Balitsky–Kovchegov equation are analyzed within the collinear approximation framework. We perform a twist decomposition of the proton structure functions F2\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$F_2$$\\end{document} and FL\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$F_{\ extrm{L}}$$\\end{document} obtained from the Balitsky–Kovchegov equation using the Mellin representation of the scattering cross-sections at high energies. In both the structure functions we find strong corrections coming from the non-linear effects in the gluon evolution at twist 2, and strongly suppressed higher twist effects. This implies that unitarization effects of high energy scattering amplitudes are mostly the leading twist effect. Furthermore we consider the double logarithmic limit of the Balitsky–Kovchegov equation for the collinear gluon distribution, and compare the result to the Gribov–Levin–Ryskin equation. We find that these two equations differ by two powers of the hard scale logarithm for the large scales.

Have consumption-based CO2 emissions in developed countries peaked?

This study innovatively divided consumption-based CO2 emissions of developed countries into domestic and foreign components using an environmentally extended multi-regional input–output model, and revealed their different driving factors using the structural decomposition analysis method. The results showed that the consumption-based emission peaked in 16 developed countries, with 14 countries peaking around 2008. Domestic emissions in all 16 developed countries had peaked, most of which accounted for 40–70% of the total consumption-based emissions. However, the foreign emissions driven by 9 peaking countries still kept increasing. Regarding domestic emissions, the decline of domestic carbon intensity was the main driving factor across 16 peaking countries. In terms of foreign emissions, carbon intensity decline, especially in main medium- and low-income countries, was the dominant factor in the CO2 emissions decrease. Significant improvements in production technology levels of medium-income countries played a key role in weakening the carbon-increasing effects of foreign emissions during the post-peak period. Thus, to further promote global carbon emissions to peak as soon as possible, peaking developed countries should provide more emission reduction funds and technologies to support the decline in carbon intensity and the improvement of production technology in medium- and low-income countries.

FEATURES OF THE DEVELOPMENT OF ADDITIVE MANUFACTURING METHODS IN APPLICATION TO LIQUID PROPELLANT ROCKET ENGINES

Abstract. Modern development of additive manufacturing methods makes it necessary to seriously consider an alternative type of production for the manufacture of liquid rocket engine structures. On the one hand, additive manufacturing has a number of undeniable advantages compared to classical methods traditionally used in the rocket and space industry. On the other hand, products obtained by this method have characteristic features that must be taken into account at the early stages of design: relatively high surface roughness, the need to adapt the geometry of existing technical solutions, material properties, etc. Moreover, a full-fledged quality control system for the resulting products is currently the moment is missing, and the standardization of the production class is just emerging. It is also important to understand the direction of development of additive manufacturing, which in the future can lead to a significant increase in the characteristics of the resulting products. This paper discusses options for classifying additive manufacturing methods, provides definitions and classification of metal 3D printing methods, according to the existing ISO/ASTM 52900 standard, as well as the main features of the technology. The main advantages and disadvantages of additive manufacturing methods are considered, and a structural decomposition of the typical design of a liquid propellant rocket engine chamber is carried out. The work aimed at manufacturing structural elements for further integration into the production cycle of liquid-propellant rocket engines is considered. The work is considered, the results of which were a combination of additive technology methods, which made it possible to apply the concept of bimetallic additive production. Such products were produced without the use of complex technological equipment and belong to the product of “evolving” additive manufacturing. Based on the results of the work, it was concluded that it is possible to use additive technologies to improve the performance of new liquid-propellant rocket engine designs.

Factors Driving China's Carbon Emissions after the COVID-19 Outbreak.

The outbreak of the coronavirus disease 2019 (COVID-19) may exert profound impacts on China's carbon emissions via structural changes. Due to a lack of data, previous studies have focused on quantifying the changes in carbon emissions but have failed to identify structural changes in the determinants of carbon emissions. Here, we use China's latest input-output table and apply structural decomposition analyses to understand the dynamic changes in the determinants of carbon emissions from 2012 to 2020, specifically the impact of COVID-19 on carbon emissions. We find that final demand per capita contributed to emissions growth at a slower pace, but production structure drove a greater carbon emissions increase than before the pandemic. Export-led emissions growth rebounded, and investment-led emissions were more concentrated in the construction sector. The carbon intensity of several heavy industries increased, e.g., the nonmetallic products sector, the metal products sector, and the petroleum, coking, and nuclear fuel sector. In addition, lower production efficiency and increased reliance on carbon-intensive inputs indicated a deterioration in production structure. For policy implications, efforts should be undertaken to increase investment in low-carbon industries and increase the proportion of consumption in GDP to shift investment-led growth to consumption-led growth for an inclusive and green recovery from the pandemic.

The effect of static stresses on the acceleration of the decomposition processes in the ferritic-martensitic steels in conditions of neutron irradiation to a dose of 85 dpa

Behavior of the corrosion-resistant EP823 steel (Fe-11Cr-Mn-Mo-Nb-V-W-Ni-Si-0.17C) and its ODS modification, hardened by yttrium, yttrium-titanium oxides (EP823-ODS) in conditions of static mechanical stress under high dose exposure in a fast-neutron reactor was studied using Mössbauer spectroscopy and electron microscopy. Mechanical stresses were revealed to result in a deformation of the fuel elements walls and the acceleration of the decomposition processes in steel structure with a release of chromium into the intermetallic χ phase and to the Me23C6 carbide formation. It was also shown that the key factor accelerating the structure decomposition upon neutron irradiation to a dose of 85 dpa at 505 °C is anisotropy of stresses between longitudinal and transverse directions of fuel cladding tube surface.

High-Voltage Instability of Vinylene Carbonate (VC): Impact of Formed Poly-VC on Interphases and Toxicity.

Full exhaustion in specific energy/energy density of state-of-the-art LiNix Coy Mnz O2 (NCM)-based Li-ion batteries (LIB) is currently limited for reasons of NCM stability by upper cut-off voltages (UCV) below 4.3 V. At higher UCV, structural decomposition triggers electrode crosstalk in the course of enhanced transition metal dissolution and leads to severe specific capacity/energy fade; in the worst case to a sudden death phenomenon (roll-over failure). The additive lithium difluorophosphate (LiDFP) is known to suppress this by scavenging dissolved metals, but at the cost of enhanced toxicity due to the formation of organofluorophosphates (OFPs). Addition of film-forming electrolyte additives like vinylene carbonate (VC) can intrinsically decrease OFP formation in thermally aged LiDFP-containing electrolytes, though the benefit of this dual-additive approach can be questioned at higher UCVs. In this work, VC is shown to decrease the formation of potentially toxic OFPs within the electrolyte during cycling at conventional UCVs but triggers OFP formation at higher UCVs. The electrolyte contains soluble VC-polymerization products. These products are formed at the cathode during VC oxidation (and are found within the cathode electrolyte interphase (CEI), suggesting an OFP electrode crosstalk of VC decomposition species, as the OFP-precursor molecules are shown to be formed at the anode.

A holistic analysis of China's consumption-based water footprint (2012–2017) from a multilevel perspective

As the world's second-largest economy, rapid socioeconomic development in China has exerted unprecedented pressure on water resources. However, there is still uncertainty regarding consumption-based water footprint (CWF) assessment across different spatiotemporal scales, especially those differentiated by green, blue, and grey water footprints. To address this knowledge gap, this study employed a multi-regional input–output (MRIO) model and structural decomposition analysis (SDA) to quantify the spatiotemporal dynamics and key drivers of consumption-based green (GCWF), blue (BCWF), and grey (HCWF) water footprints in mainland China during 2012–2017. The main findings of the study are as follows. (1) The HCWF is approximately 4.4 times greater than the sum of the GCWF and BCWF, with water consumption caused by pollution significantly exceeding direct consumption. However, there was a significant decrease in all three CWFs after 2015, particularly HCWF. (2) The spatial distribution pattern of the CWF shows high values in the east and south and low values in the west and north, while virtual water (VW) transfer through commodity trade occurs mainly from inland to coastal regions. (3) The three highest water-consuming sectors were agriculture, food and tobacco processing, and construction, accounting for over 70% of the total water consumption. (4) Water efficiency and consumption patterns are crucial factors in reducing CWF, while affluence levels have the greatest impact on increasing CWF, followed by changes in industrial structure after 2015. Overall, the results of this study contribute to a comprehensive understanding of China's regional and sectoral water consumption throughout the supply chain. In addition, our findings identified regions and sectors with high water consumption and their drivers, which can inform policy decisions and contribute to synergistic cross-regional regulation and sustainable water resources management.

Identifying the discs, bulges, and intra-halo light of simulated galaxies through structural decomposition

ABSTRACT We perform a structural decomposition of galaxies identified in three cosmological hydrodynamical simulations by applying Gaussian mixture models (GMMs) to the kinematics of their stellar particles. We study the resulting disc, bulge, and intra-halo light (IHL) components of galaxies whose host dark matter haloes have virial masses in the range M200 = 1011–$10^{15}\, {\rm M_\odot }$. Our decomposition technique isolates galactic discs whose mass fractions, fdisc, correlate strongly with common alternative morphology indicators; for example, fdisc is approximately equal to κco, the fraction of stellar kinetic energy in corotation. The primary aim of our study, however, is to characterize the IHL of galaxies in a consistent manner and over a broad mass range, and to analyse its properties from the scale of galactic stellar haloes up to the intra-cluster light. Our results imply that the IHL fraction, fIHL, has appreciable scatter and is strongly correlated with galaxy morphology: at fixed stellar mass, the IHL of disc galaxies is typically older and less massive than that of spheroids. Above $M_{200}\approx 10^{13}\, {\rm M_\odot }$, we find, on average, fIHL ≈ 0.37, albeit with considerable scatter. The transition radius beyond which the IHL dominates the stellar mass of a galaxy is roughly $30\, {\rm kpc}$ for disc galaxies, but depends strongly on halo mass for spheroids. However, we find that no alternative IHL definitions – whether based on the ex situ stellar mass, or the stellar mass outside a spherical aperture – reproduce our dynamically defined IHL masses.

Revealing the changes in water footprint at the provincial level and their drivers in the Yellow River Basin, China

Water scarcity has become the most significant limiting factor for sustainable economic and social development in the Yellow River Basin (YRB). Despite this, most current studies on water resources in the YRB from a water footprint (WF) perspective have focused on WF measurements and have explored the influencing factors of WF changes in certain industries, while the impact mechanisms driving regional WF changes remain unclear. To bridge this research gap, the WF of nine provinces in the YRB for 2012 and 2017 were quantified using an environmentally extended multi-regional input-output model (EE-MRIO), and the driving forces of regional WF changes were explored via structural decomposition analysis (SDA). The results showed that the WF of the YRB increased by 3.8% to 113.64 billion m3 between 2012 and 2017. With rapid economic development and enhanced inter-regional trade links, the external WF has played an important role in meeting local water demand. Technological advances and production structure adjustments contribute to the reduction of the WF, thus promoting the sustainable use and management of the YRB’s water resources. Both consumption patterns and final demand per capita have dominated the YRB’s WF growth, particularly in the economically developed middle and lower reaches, where urban household consumption drove the largest WF, accounting for over 40%. Therefore, in the future, continuous optimization of the consumption structure and guidance of green consumption awareness are expected to contribute more to the reduction in WF. The findings of this study reveal the primary causes of WF changes in the YRB and offer a theoretical justification for the formulation of water conservation and sustainable utilization policies.

Asymmetric effects of oil price shocks on EUR/USD exchange rate and structural shock decomposition in a BVAR model with sign restriction

We use a VAR model with two exogenous and eight endogenous variables to evaluate the asymmetric effect of oil price changes on the EUR/USD exchange rate. The parameters are estimated with the Bayesian technique using the U.S. and the Eurozone quarterly data from 2001 to 2021. The sign restriction methodology is employed to obtain the VAR model’s structural form from its reduced form. The suggested metrics show highly time-variant oil price effects on the EUR/USD exchange rate. Oil price variability accounts for about half of the exogenous variables shocks that account for about one-third of the deterministic part of the model, which explains about two-thirds of the EUR/USD exchange rate volatility. The structural shock and historical variance decomposition identify significant time-dependent endogenous variables shocks behind the EUR/USD exchange rate variability. The impulse–response function shows asymmetric direct and indirect effects of oil shocks on the EUR/USD exchange rate, whose reaction to a positive oil price shock is more intensive, less smooth, and takes longer than in a negative shock. The dollar appreciates within three quarters after oil price increases, which suggests the United States has a specific comparative advantage compared with the Eurozone in offsetting the effects of the oil shocks.

Revisiting the Role of Imported Inputs in Asian Economies

Purpose - Global production chains and their impacts on economic growth have drawn extensive attention from researchers. Close relationships among global production chains, export and economic growth have been illuminated, as evidenced by the fast and stable economic growth of East Asian economies. These economies perform various roles within global production chains using offshoring, in which the impact of import on domestic gross output is as strong as that of export. The impact of import on economic growth would depend on whether imported inputs substitute or complement domestic inputs production, which is likely to vary according to individual countries' functions within global production chains. The economic growth of concerned countries would also be diverse. However, little attention has been paid to the impact brought by imports compared to its significance.
 Design/methodology - The principal methodology used in this paper is structural decomposition analysis (SDA), widely chosen to elucidate the impact of various factors on domestic gross output using input-output tables. This paper extracts trade data of six Asian economies from the World Input-Output Database (WIOD) 2016 release that covers 43 countries for the period 2000-2014. The extracted data is then categorised into 37 sectors. First, this paper calculates the Feenstra-Hanson Offshoring Index (OSI) of each country. It then applies SDA to measure the changes in each economy's gross output, export, import input coefficients, and domestic input coefficients. Finally, after taking the first difference from pooled time-series data, it estimates the correlations between imported input coefficients and OSI using the ordinary least square (OLS) method.
 Findings - The main findings of this paper can be summarised as follows. Firstly, all six countries have increasingly engaged in global production chains, as evidenced by the growing size of OSI. Secondly, there are negative correlations in five countries except Japan, with sectoral differences. Thirdly, changes in import input coefficients are not negative in all six countries, indicating that offshoring does not necessarily substitute for domestic inputs production but does complement it and, therefore, fosters their economic growth. This is observed in China, Indonesia, Korea and Taiwan. Offshoring has led to an increase in the use of imported inputs, which has, in turn, stimulated domestic inputs production in these countries.
 Originality/value - While existing studies focus on the role of export in evaluating the impact of participating global production chains, this paper explicitly examines the unexplored impact of import on domestic gross output by considering both the substitution and the complementary effect, using the WIOD. The findings of this paper suggest that Asian economies have achieved fast and stable economic growth not only through successful export management but also through effective import management within global production chains. This paper recommends that the Korean government and enterprises carefully choose offshoring strategies to minimise disruption to domestic production chains or foster them.

Dietary shifts drive the slowdown of declining methylmercury related health risk in China

Chinese population suffers severe health risk from dietary methylmercury (MeHg) exposure. However, the temporal change of such risk and socioeconomic driving factors remain unknown. This study investigates this issue by compiling time-series inventory of China's MeHg-related health risk at the provincial scale and revealing critical socioeconomic influencing factors through structural decomposition analysis. Results show that the per-fetus IQ decrements from dietary MeHg exposure have declined by 60% nationally during 2004–2019. Such decline results from the joint effects of dietary shifts (contributing 44%) and the decrease of MeHg concentrations in foods consumed (contributing 56%). However, the declining trend has slowed down since 2014 and even leveled off after 2016, which is mainly affected by dietary pattern changes. Especially, the increased intake level and proportion of fishes in underdeveloped provinces of China have dominated the slowdown of declining trend after 2016. Moreover, the affluence and education levels have significantly negative associations with per-fetus IQ decrements. Rich and well-educated people have higher ability of risk perception, which indicates the importance of rational consumption patterns. Our findings can help develop socioeconomic regulatory policies on reducing per-fetus IQ decrements from dietary MeHg exposure in China.

Lignin with enhanced photothermal performance for the preparation of a sustainable solar-driven double-layer biomass evaporator

The undesirable photothermal conversion performance of lignin limits the potential for directing use as a photothermal conversion material, and no strategies have been found to enhance the photothermal conversion efficiency of lignin. Herein, three modified lignin of corn stover alkali lignin (DEHL), pine alkali lignin (DAL) and birch alkali lignin (DTAL) with excellent photothermal conversion efficiency and fast temperature response was prepared by a one-step iodocyclohexane (ICH) activation strategy. The maximum temperature of the DEHL, DAL and DTAL can reach to 138 °C, 157 °C, and 172 °C in 12 min under 0.15 W/cm2 compared to the native lignin. Moreover, the photothermal conversion efficiency of the DEHL, DAL and DTAL was calculated to be 36.52 %, 36.19 % and 43.19 % by ICH modification. The photothermal enhancement mechanism of the modified lignin was determined by various characterizations and simulation calculations, which can be summarized that the activation of lignin by ICH breaks the molecular structure and reduces the methoxy content of the lignin, which enhances the intermolecular bonding, and the hydrogen bonding between the phenolic hydroxyl groups strengthens the π-π intermolecular interactions between the benzene rings. In addition, a double-layer biomass aerogel evaporator (DAGS) with cost-friendly and superior evaporation performance was synthesized by chemical cross-linking using DTAL as the photothermal agent. The evaporation rate of 4DAGS can be as high as 2.063, 2.024, 2.259 and 2.447 kg/(m2∙h) in water, 3.5 wt% seawater, and 200 mg/L of MG or MB wastewater under 1sun. And no salt was observed on the surface of the 4DAGS after a long period of 36 h of operation in 3.5 wt% seawater, suggesting the outstanding salt-reject performance of the aerogel. Furthermore, there is no structural damage and chemical decomposition found on 4DAGS after 24 h immersion in NaOH and HCl solutions, demonstrating the excellent acid and alkali resistance of the synthesized aerogels. This work may offer a novel strategy for the photothermal performance enhancement of lignin and expand the potential application in solar-driven evaporation materials.

A multidimensional factorial enviro-economic model: Approaches of retrospective decomposition and prospective projection for energy systems

Understanding the patterns of energy usage through simulation and prediction from multiple perspectives is crucial for alleviating energy-environmental conflicts and achieving sustainable energy system development. Despite their importance, multidimensional interactions among the production, demand, and supply sides have not been systematically characterized, thus representing a significant research gap. This paper aims to address this gap by developing a a multidimensional factorial enviro-economic (MFEE) model, which offers an in-depth investigation of Guangdong's energy system. This model, designed for retrospective decomposition (1997–2017) and prospective projections (2035), uniquely links historical and future analysis from systematic and sectoral perspectives through structural decomposition analysis, sectoral evolution analysis, and the Biproportional Scaling RAS method. Our findings reveal that the final demand level and Research & development (R & D) are the principal drivers of increased energy usage. We also found that the wholesale and retail sector have the most significant impact on demand and input sides, accounting for over 70 %. Furthermore, the interaction of key sectors from the production-based perspective notably influences system symbiosis. To effectively manage these dynamics, our study recommends regulating and controlling measures for the circulation sector that consider the benefits of both the energy sector and the accommodation and catering sector. This comprehensive analysis, therefore, offers scientifically-supported guidance for sustainable energy system development.

First-principles study of structural, hydrogen bonds and mechanical properties of α-RDX under hydrostatic compression

The mechanical response of cyclotrimethylene trinitramine (RDX) under pressure loading is closely correlated with the structural deformation and chemical decomposition. The structural, hydrogen bonds (HBs) and mechanical properties of α-RDX under hydrostatic compression between 0 and 4 GPa have been studied using dispersion corrected density functional theory (DFT-D). The oxygen atoms in the E branch (AAE configuration) form important intermolecular HBs with pressure increasing, wherein the bond order of the HB marked as O3∙∙∙H5-C3 reaches up to 0.0716 (∼1.8 times of the intramolecular bonds) at 4 GPa. This HB directly prompts the pressure-dependent increase of Young’s modulus in y direction. α-RDX keeps mechanically stable below 4 GPa, while it shows a pressure-induced ductility owing to deformation tendency in (010) plane (i.e., ac plane). Finally, the pressure-dependent anisotropy, sound velocities and Debye temperature are also discussed based on the calculated mechanical moduli.

Investigating the structure, bonding, and energy decomposition analysis of group 10 transition metal carbonyls with substituted terminal germanium chalcogenides [M(CO)3GeX] (M = Ni, Pd, and Pt; X = O, S, Se, and Te) complexes: insight from first-principles calculations.

This research focused on the theoretical investigation of transition metal carbonyls [M(CO)4] coordinated with terminal germanium chalcogenides complexes [M(CO)3GeX], where M represents Ni, Pd, and Pt and X represents O, S, Se, and Te labeled 1-15. While the notable complexes M(CO)4 (where M = Ni, Pd, Pt) numbered 1, 6, and 11 are of significance, substituting one of the CO ligands in 1, 6, and 11 with a GeX ligand (where X = O, S, Se, or Te) result in substituted complexes (2-5, 7-10, and 11-15). Substituting of the CO ligand slightly alters these bond angles. Specifically, the ∠CMC bond angles for [Ni] complexes range from 111.9° to 112.2°, for [Pd] complexes from 111.4° to 111.7°, and for [Pt] complexes from 112.4° to 112.8°. These findings indicate a minor deviation from the tetrahedral geometry due to the influence of the new GeX ligand. Similarly, there is a slight change in the geometry of the metal complexes, where the ∠GeMC angles for [Ni] complexes are between 106.7° and 106.9°, for [Pd] complexes between 107.2° and 107.5°, and for [Pt] complexes between 105.9° and 106.4°. Comparing among the substituted GeX complexes, those containing GeTe exhibit a higher natural bond orbital (NBO) contribution from the Ge atom compared to the M atom. Consequently, based on the above observations, it can be inferred that GeX acts as an effective sigma donor in contrast to carbonyl compounds. Results of energy decomposition analysis (EDA) for the M-CO bond in 1, 6, and 11 and for the M-GeX bond in the other [M(CO)3(GeX)] complexes where M = Ni, Pd and Pt. The percentage contribution of ΔEelstat and ΔEorb shows a relatively identical behavior for all ligands in case of each metal complexes. Density functional theory (DFT) calculations were conducted using the B3LYP/gen/6-31G*/LanL2DZ level of theory to examine transition metal carbonyls [M(CO)4] coordinated with terminal germanium chalcogenides complexes [M(CO)3GeX], where M represents Ni, Pd, and Pt, and X represents O, S, Se, and Te labeled 1-15 utilized through the use of Gaussian 09W and GaussView 6.0.16 software packages. Post-processing computational code such as multi-wave function was employed for results analysis and visualization.

RESESRCH OF THE KINETIC CHARACTERISTICS OF THE SOLID-STATE TRANSFORMATION OF Kh30N60M9 and Kh23N65M13 ALLOYS IN THE TEMPERATURE RANGE OF 500-650 °C, ACCORDING TO THERMOGRAVIMETRIC ANALYSIS

The results of the study of the structural states of single-phase alloys Kh30N60M9 and Kh23N65M13 for the conditions of heating samples at a rate of 1.0 °C/min are presented. The structural states of the alloy samples were obtained by water quenching; the alloy quenching temperature was 1107 and 1135 °C, respectively. The article presents the results of thermal analysis of samples of the considered alloys in the conditions of an inert gas - argon, without carrying out its additional purification from oxygen, the volume fraction of which was up to 0.003 %. As a characteristic of the structure state, an indicator of the rate of weight gain is proposed. According to the experimental results of weight gain, an original method for calculating this kinetic indicator as the rate of solid-state transformation, then the conversion coefficient (k) is proposed. The true values of weight gain considered are referred to the true values of temperatures in the temperature range of 500-650 °C, when the scales of variables and values of variables are proposed in the range of true values (0..1). As a result of the work, confirmation of the improved thermophysical characteristics for the Kh30N60M9 alloy in the considered temperature range was found, in comparison with the Kh23N65M13 alloy. The calculated indicators of the conversion coefficients of the alloy samples were confirmed by experimental data on the amount of enthalpy in the considered gradations of the temperature range, for which the areas under the DTA graphs of the Kh30N60M9 and Kh23N65M13 alloy samples were calculated for the conditions of heating the samples at a rate of 1.0 °C/min. It was found in the work that the decomposition of the solid solution structure is more inherent and essential for the structure of the Kh23N65M13 alloy in the temperature range of 500–650 °C.