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Class cohesion, understood as the degree of how tightly are bound or related its internal elements to one another, is often a critically important for quality assurance (QA) of object-oriented software. Typically, a low cohesive class contains disparate and/or isolated members; therefore, cohesion level is useful for detecting of poorly designed classes and ensuring faster and better system reconfiguration. There are over thirty different metrics to measure cohesion, based on class member analysis in terms of number and structure of attributes and methods. Utilizing class cohesion metrics can promote Java code static analysis quality, improve object-oriented programming practices, and suggest advanced and efficient ones. The jPeek tool with its library for inspecting objects in Java was developed by Huawei Technologies Co. Ltd. to achieve these goals [1]. The idea of code quality assessment is well known for a long time; class connectivity metrics were proposed by community several years ago and have not become generally applicable practice in industrial programming. The main goal of this study is to make a methodology for using cohesion metrics to analyze code that allows users to estimate their projects in the most appropriate way. During the study, each of the metrics was studied in detail, the influence of programming patterns on the result of the metrics was evaluated, and as a result a methodology for using the metrics to obtain the most reliable estimate was formulated.

A more accurate characterization of the sources and sinks of methane (CH4) and carbon dioxide (CO2) in the vulnerable Arctic environment is required to better predict climate change. A large-scale aircraft campaign took place in September 2020 focusing on Siberian coast. CH4 and CO2 were measured in situ during the campaign and form the core of the study. Measured ozone (O3) and carbon monoxide (CO) are used here as tracers. Compared to the reference (i.e., the seasonal value at Mauna Loa, Hawaii, US), median CH4 mixing ratios are fairly higher (1890-1969 ppb vs 1887 ppb) while CO2 mixing ratios from all flights are lower (408.09-411.50 ppm vs 411.52 ppm). We also report on 3 case studies. Our analysis suggests that during the campaign the European part of Russia’s Arctic and Western Siberia were subject to long-range transport of polluted air masses, while the East mainly was under the influence of local emission of greenhouse gases. The relative contributions of anthropogenic and natural sources of CH4 in Siberia are simulated using the Lagrangian model FLEXPART in order to identify dominant sources in the boundary layer and in the free troposphere. In western terrestrial flights, air masses composition is influenced by from wetlands and anthropogenic activities (waste management, the fossil fuel industry and to a lesser extent the agricultural sector), while in the East, emissions are dominated by freshwaters, wetlands, and the oceans, with an ambiguous contribution from likely anthropogenic sources related to fossil fuels. Our results generally highlight the importance of the contribution form freshwater and oceans emissions and, combined with the large uncertainties associated with them, suggest that the emission from these aquatic sources should receive more attention in Siberia.

The stratosphere and troposphere are the main layers that define a significant part of the atmospheric processes of our planet. They are demarcated by the tropopause - a layer that has a stable stratification and makes it difficult to exchange air between them. As a consequence, the composition of the air differs slightly in the stratosphere and troposphere. However, the tropopause is not a fully material impermeable surface and therefore the exchange of impurities between both layers occurs. Under the conditions of a changing climate, the composition of the air in the troposphere has also noticeably changed. Therefore, it is important to study the processes of air exchange between the troposphere and stratosphere in a warming climate, especially if we take into account that one of the proposed geoengineering methods assumes to affect climate-forming factors by means of spraying sulphate particles into the stratosphere.Here, we present the results of airborne measurements of the size distribution and chemical composition of aerosols carried out at the tropopause level and in the upper troposphere and lower stratosphere (UTLS) using the 'Optik' Tu-134 aircraft laboratory as a research platform. For the analysis, we have chosen 14 flight segments when the aircraft crossed the tropopause, which level was determined by the temperature gradient (up to 2°C/ km). All the selected profiles of atmospheric constituents were measured over the Russian Arctic seas or coastal areas, since the tropopause in the northern latitudes is much lower than in the middle ones.Significant differences in the elemental composition of aerosol particles were revealed in the UTLS. Si was dominated in the composition of stratospheric particles, and Fe or Al in the tropospheric ones. The ionic composition of the LS aerosols was predominantly represented by sulfates (SO42-), while tropospheric ones by a group of different ions.The particle number size distributions (PNSD) in both UT and LS were dominated by the Aitken mode (20-50 nm). At the same time, there were some differences in PNSD – in the stratosphere, the distribution curve was shifted towards larger sizes that suggests the older age of particles measured there. It is also important to note that the nucleation mode particles (3–20 nm) were also detected during some flights in the lower stratosphere. This indicates that, despite the low humidity and the very low content of ammonia here, the processes of the new particle formation (NPF) in the stratosphere were taking place. Taking into account the dominance of SO42- in the ionic composition, one can be assumed that sulfuric acid played a dominant role in the lower stratospheric NPF.This work was supported by the grant of the Ministry of Science and Higher Education of the Russian Federation (Agreement No 075-15-2021-934).

Aerosols play an important role in radiation processes in the atmosphere, as well as they have a significant impact on global and regional air quality. The process of the atmospheric nanoparticle formation starts from in situ conversion of condensable vapors. Then, the freshly formed nanometer-size clusters begin to grow due to the condensation of nucleating vapours on them and a self-coagulation as well, thus reaching the optically active size ranges. The relative contribution of the above mechanisms can be estimated by the chemical composition of size-segregated particles. Here, we present preliminary results of the analysis of aerosol samples characterizing the inorganic chemical composition of particles ranging from a few nm to 10 mm. The sampling was performed at Fonovaya Observatory (West Siberia) in October 2021 by means of the Model 125R Nano-MOUDI Impactor.The analysis showed that in the lowest size range (42-, Cl-, K+, Na+, H+. The growth of the nucleation mode particles to the size range of 60-100 nm was accompanied by increasing content of SO42-, Na+, H+ ions to 50, 37 and 13%, respectively, suggesting the condensation of H2SO4 vapours or the coagulation of particles contained mainly Na2SO4. A content of ammonium ions (NH4+) appeared to be significant only in the accumulation mode size range (0.1-1.0 mm). Nitrates (NO3-) were detected mainly in the Aitken mode particles and then their contribution increases in accumulation and coarse mode ranges.This work was supported by the RFBR grant No. 19-05-50024 (Microparticles in the atmosphere: formation and transformation in the atmospheric surface layer and in the free troposphere, radiation effects and impact on public health).

The idea of code quality assessment is well known for a long time; class connectivity metrics were proposed by community several years ago and have not become generally applicable practice in industrial programming. The objective of the study, part of which we present in this paper, is to critically analyze the metrics available for today: Are they completely unusable, or considering their specifics can be useful helpers for software specialists. Specifically, we try to answer the questions: Are there any connection between design patterns and cohesion metrics, and how these patterns affect metrics if they do.

The continuous ground-based measurements of greenhouse gases carried out in Siberia in the past two decades allowed the long-term trends, as well as the diurnal and seasonal cycles of CO2 and CH4 to be derived for this poorly studied region (Belikov et al., 2019). To date, these in-situ observations are made at the joint Japan-Russia Siberian Tall Tower Inland Observation Network (JR-STATION) consisted of 6 automated stations that should be maintained several times per year. In late October to early November 2018, we have undertaken the first mobile campaign to derive a distribution of CO2 and CH4 concentrations at high spatial resolution while traveling to the sites of the above network. For that, we used a commercially available GHG CRDS analyzer (G4301, Picarro Inc., Santa Clara, CA, USA) installed in an off-road vehicle (Arshinov et al., 2019). Over one trip, the instrument were driven over 7000 km throughout the study area.In March, June, August, and October 2019 we have performed four more campaigns along the same route. This enabled the seasonal pattern of CO2 and CH4 concentrations to be obtained over a huge area of West Siberia between 54.5° and 63.2° north latitude and between 62.3° and 85.0° east longitude, as well as to reveal a large- and small-scale spatial heterogeneity in CH4 mixing ratios particularly over wetland regions. We plan to continue mobile campaigns to cover interannual variations. This work was supported by the Ministry of Science and Higher Education of the Russian Federation under State Contract No. 14.616.21.0104 (ID No RFMEFI61618X0104).Belikov, D.; Arshinov, M.; Belan, B.; Davydov, D.; Fofonov, A.; Sasakawa, M.; Machida, T. Analysis of the Diurnal, Weekly, and Seasonal Cycles and Annual Trends in Atmospheric CO2 and CH4 at Tower Network in Siberia from 2005 to 2016. Atmosphere 2019, 10, 689.Arshinov, M.Yu.; Belan B.D.; Davydov D.K.; Kozlov A.V., Fofonov A.V., and Arshinova V. Heterogeneity of the spatial distribution of CO2 and CH4 concentrations in the atmospheric surface layer over West Siberia: October-November 2018, Proc. SPIE 11208, 25th International Symposium on Atmospheric and Ocean Optics: Atmospheric Physics, 1120831 (18 December 2019);https://doi.org/10.1117/12.2539205

Some published experimental results on the thermodynamic data of pure solid CaO and MgO significantly contradict the widely used data in review books or tables, such as JANAF data. We scrutinized all the original experimental data forming the basis in review books and tables in order to establish a more realistic uncertainty range. The two Gibbs energy functions of CaO and MgO are combined with those of all other relevant phases to develop a thermodynamic database for the Mg–Ca–O system. The first systematic study of the calculated Mg–Ca–O phase diagram is presented. This phase diagram is validated by recently obtained dedicated experimental data using in-situ synchrotron radiation diffraction to study phase formation and reactions during melting and solidification of Mg and Mg–Ca alloys with CaO-additions below 1050 K. Intricacies in the solidification path of Mg-rich ternary alloys are revealed by the present thermodynamic calculations. Mg-rich alloys are categorized in four groups according to their participation in different invariant four-phase reactions. The development of non-equilibrium constitution of four phases, (Mg) + Mg2Ca + MgO + CaO, in the fully solidified sample is explained.

First results on the constitution of the ternary systems Li-Sn-C and Li-Sn-Si are presented. Extrapolation calculations from the binary boundary systems allow identifying three alloys with key compositions that yield substantial information about the ternary phase diagrams. These alloys were characterized after long-term annealing using X-ray diffraction (XRD) and differential scanning calorimetry (DSC). The XRD and DSC measurements suggest the formation of a solid solution of the isostructural phases Li5Sn2 and Li7Si3 instead of predicted three phase equilibrium in the Li-Sn-Si system. Ternary phases are not observed.

Investigations on the thermodynamics of alloy-type anode materials have been carried out for the quaternary Li–C–Si–Sn system. Phase equilibria and phase stabilities were characterized in the binary subsystems Li–C, Li–Si, Li–Sn. The Calphad method was first used to optimize or completely re-establish all binary subsystems containing Li. For reasons of consistency, the binary subsystem Si–C had to be revisited and its Calphad description was modified. The ternary phase diagrams were then tentatively calculated by extrapolation from the binary subsystems and confirmed by key experiments. No ternary compounds were found. In order to verify the applicability of the anode materials in real batteries, some of the materials were nanostructured by ball milling and spark plasma sintering, the corresponding nanostructures were characterized. Theoretical predictions that nanograined Li2C2 can also be used as cathode material were verified experimentally. The methodologies worked out in the present project (e. g. nanoscale structure transmission electron microscopy analysis, glow discharge optical emission spectroscopy) were also employed in other projects and led to publications concerning other materials such as Mg alloys, carbon nanofibers and an Mn-based antiperovskite.

An interlaboratory study was performed to determine the heat capacity of an active material for lithium-ion batteries with layered structure and nominal composition LiNi1/3 · Mn1/3Co1/3O2 (NMC111). The commercial sample, which was characterized using powder X-ray diffraction and inductively coupled plasma–optical emission spectroscopy, is single phase (α-NaFeO2 crystal structure) with a composition of Li1.02Ni0.32Mn0.31Co0.30O2. Heat capacity measurements of the homogeneous sample were performed at five laboratories using different operators, methods, devices, temperature ranges, gas atmospheres and crucible materials. The experimental procedures from each laboratory are presented and the results of the individual laboratories are analyzed. Based on a comprehensive evaluation of the data from each laboratory, the heat capacity of the NMC111 sample from 315 K to 1 020 K is obtained with an expanded reproducibility uncertainty of less than 1.22 %.

The phase equilibria and thermodynamic properties of the ternary Li-Si-C system are crucial for developing new anode materials containing Si and/or C for Li-ion batteries. We carried out the long time annealing experiments and confirmed the key three-phase equilibrium of βLi 2 C 2 +SiC + Li 7 Si 3 at 630 °C–650 °C. A consistent thermodynamic description of the Li-Si-C ternary system has been constructed based on the recently published Li-Si system, and the Li-C and Si-C binary systems that we revised in this work. The revision requires a more negative Gibbs energy for the αLi 2 C 2 and βLi 2 C 2 phases in the Li-C system, and a more positive Gibbs energy for the SiC phase in the Si-C system. The more negative Gibbs energy of the βLi 2 C 2 phase requires an associate solution model to be introduced for the liquid phase. Calculated partial pressures from the revised thermodynamic description of the Li-C binary system show better agreement with the experimental data. The calculated phase diagram sections of the Li-Si-C ternary system are not only in good agreement with the key annealing experiment results, but also with differential scanning calorimetry results.

A consistent thermodynamic description of the Li-Si system and its extension to the Li-Si-H system is developed based on comprehensive Calphad-type assessment of all pertinent thermodynamic and phase equilibrium data. Key experiments were performed by measuring the equilibrium pressure for the hydrogenation of the lithium silicides at 773 K, 748 K and 723 K. The Gibbs energy functions of the Li-Si compounds developed in this work are validated by direct comparison of the predicted hydrogen pressure with experimental data. The interrelation of the hydrogen absorption pressure with the calculated Li-Si-H ternary phase diagram is also elucidated. The calculated Li-Si phase diagram, both on chemical potential and composition scale, is well supported by the entity of experimental data. In addition to the stable intermetallics Li17Si4, Li16.42Si4 (Li4.11Si), Li13Si4, Li7Si3, Li12Si7, LiSi also metastable Li15Si4 and an approximate for amorphous Si(Li) is included in the thermodynamic modeling. Qualitative prediction of open-circuit voltage curves during metastable lithiation/delithiation of Si as advanced anode material for Li-ion batteries at room temperature is made.

A first study on the ternary phase diagram Li–Si–C is presented. On the basis of extrapolation calculations of the binary boundary systems, two alloys with key compositions were examined using DSC measurements, long-term annealing experiments and X-ray diffraction analysis. Stable phases were determined for the two key compositions. A three-phase equilibrium consisting of α-Li2C2, SiC and Li7Si3 was identified. Stable Li7Si3 was observed independently of the initial alloys used for the annealing experiments. Ternary phases were not observed.

Vector embedding models have recently become popular for encoding both structured and unstructured data. In the context of knowledge graphs such models often serve as additional evidence supporting various tasks related to the knowledge base population: e.g., information extraction or link prediction to expand the original dataset. However, the embedding models themselves are often not used directly alongside structured data: they merely serve as additional evidence for structured knowledge extraction. In the metaphactory knowledge graph management platform, we use federated hybrid SPARQL queries for combining explicit information stated in the graph, implicit information from the associated embedding models, and information extracted using vector embeddings in a transparent way for the end user. In this paper we show how we integrated RDF data with vector space models to construct an augmented knowledge graph to be used in customer applications.

Phase equilibria and transformations in ternary Mg–Gd–Zn alloys were studied experimentally by investigating 22 samples with up to 40 at.% Gd and 60 at.% Zn. These results, combined with a critical review of literature data, were used to develop thermodynamic descriptions of the Gd–Zn and the Mg–Gd–Zn systems and to calculate the Mg–Gd–Zn phase diagram in the entire composition range. In the ternary system the hexagonal long-period stacking ordered structure 14H, the hexagonal phase H1, Gd11Mg24Zn64, and five solid solution phases with ternary compositions, GdMg5, GdMg3, GdMg2, Gd(Mg,Zn), and W are found to be stable, whereas the icosahedral phase I, GdMg3Zn6, and other hexagonal phases are metastable. In addition, a new stable phase Gd20Mg19Zn81 with a face-centered cubic structure is identified in the Mg–Gd–Zn system. Based on the thermodynamic description obtained in this work, the microstructures and phase transformations previously observed in the as-cast, solution heat treated and aged conditions are discussed. It is shown that the current thermodynamic predictions are in good accord with the experimental findings, suggesting the viability of such an approach for the microstructure design of Mg–Gd–Zn alloys.

Knowledge graph management use cases often require addressing hybrid information needs that involve multitude of data sources, multitude of data modalities (e.g., structured, keyword, geospatial search), and availability of computation services (e.g., machine learning and graph analytics algorithms). Although SPARQL queries provide a convenient way of expressing data requests over RDF knowledge graphs, the level of support for hybrid information needs is limited: existing query engines usually focus on retrieving RDF data and only support a set of hard-coded built-in services. In this paper we describe representative use cases of metaphacts in the cultural heritage and pharmacy domains and the hybrid information needs arising in them. To address these needs, we present Ephedra: a SPARQL federation engine aimed at processing hybrid queries. Ephedra provides a flexible declarative mechanism for including hybrid services into a SPARQL federation and implements a number of static and runtime query optimization techniques for improving the hybrid SPARQL queries performance. We validate Ephedra in the use case scenarios and discuss practical implications of hybrid query processing.

Thermodynamic descriptions are developed for the ternary Mg-Ce-Sn and the quaternary Mg-Ca-Ce-Sn systems by combining the Calphad method with experimental investigations on selected key samples. Ten ternary and six quaternary alloy samples were prepared from the elements in sealed Ta-capsules and studied by differential thermal, microstructural and x-ray diffraction analyses. These data were used together with the scarce literature data to develop and/or validate the thermodynamic descriptions and the calculated phase diagrams in the Mg-rich regions. Phase formation and microstructure development is also compared with solidification simulations under equilibrium and Scheil conditions. The ternary MgSnCe compound is found to be extremely stable. In the quaternary Mg-Ca-Ce-Sn system it exhibits very large solid solubility of Ca and exists as a single solid phase up to the known intermetallic solution phase range MgSnCa-Ca2Sn, all exhibiting the same crystal structure. These features result in significant complexity of phase equilibria in quaternary Mg-rich alloys.

Thermodynamic and constitutional data of the Li–Si system were critically reviewed and the importance of using original experimental data is highlighted, as opposed to a previous thermodynamic modeling of this system. The C p -functions of all Li–Si compounds were experimentally determined for 2–900 K and those for pure solid Li and Si from 0 to 298 K from experimental literature data. The reliability of solubility data for the dilute solution of Si in liquid Li was assessed by thermodynamic considerations. A consistent thermodynamic description of all solid phases in the Li–Si system from 0 K to high temperature is developed, jointly with that for the liquid phase, using the Calphad method. The first calculated and validated Li–Si phase diagram from 0 K to liquidus temperatures is presented. Experimental liquidus data are found to be inconsistent with well established experimental thermodynamic data and further research is required.

Information about the thermodynamic stability of LiC 6 in the literature is ambiguous at present. The thermodynamic stability of LiC 6 and Li 2 C 2 is investigated by an approach combining differential scanning calorimetry (DSC), X-ray diffraction (XRD) and long-time annealing experiments. It is found that LiC 6 is thermodynamically unstable above 330 °C, where in the corresponding composition range Li 2 C 2 and graphite are in thermodynamic equilibrium. During heating, a de-intercalation process is observed in LiC 6 , and eventually a transformation to Li 2 C 2 and graphite. The enthalpy of formation of LiC 6 is below zero as it forms from the pure components, the limits of the enthalpy of formation are set by the tangents to the enthalpies of formation of Li 2 C 2 and graphite. An order–disorder transition in LiC 6 was not observed.

Multi-component magnesium alloys exhibit a complex constitution, requiring computational thermodynamics for a quantitative treatment that goes beyond “just” phase diagrams. The basis for this approach is a thermodynamic Mg alloy database, which is developed in an ongoing long-term project in our group since many years. Three distinctive features of this database are highlighted in this report: (i) Combination of own key experimental work with theoretical modeling to generate consistent data, (ii) Systematic quality control of the database using a variety of elaborated cross-checks, and (iii) Complete and entire composition range descriptions for all pertinent binary or ternary subsystems whenever possible. The latter point is decisive for the capability to use this tool for new alloys, far beyond the composition limits of conventional Mg alloys. It is demonstrated by correctly predicting the phase formation in aluminum-rich six component alloys. Also, new Mg-solder alloys can be tackled that are essentially Zn-rich.

The long-period stacking ordered structures 18R and 14H formed in Mg–Y–X (X = Zn, Cu, Ni) systems have received considerable interest over the past decade, but their thermal stability and relationships with other intermetallic phases in the Mg–Y–X systems remain to be unambiguously established. In this study, the occurrence and transformations of long-period stacking ordered structures 18R and 14H are clarified in as-cast and heat-treated Mg–Y–Zn alloys. The 18R structure is a stable equilibrium phase that forms directly from the melt whereas the 14H cannot form directly from the melt but forms in a solid-state transformation. That explains the absence of 14H in the as-cast microstructures of the alloys. These findings are embedded in the complete description of Mg–Y–Zn phase equilibria, generated by Calphad-type thermodynamic calculations and verified for a range of Mg-rich alloys by electron microscopy and thermal analysis. It is found that the 18R is a stable equilibrium phase that exists in the high temperature range from 753 to 483 °C, and that the 14H is an equilibrium phase below 537 °C. In the small temperature range between 537 and 483 °C, the 18R and 14H can co-exist in equilibrium in some special alloy compositions.

The growth restriction factor Q is the key quantity in current descriptions of the solutal effect on grain growth and grain refinement during solidification of alloys. A rigorous treatment for the evaluation of Q in multicomponent alloys based on consistent thermodynamic descriptions of the alloy phase equilibria is presented. On closer inspection the conventional approach to calculate Q in multicomponent alloys from liquidus gradient mi and partition coefficient ki must fail for a wide range of common alloys exhibiting minute amounts of primary crystallizing intermetallic phase, exemplified for Mg–Al–Mn and Al–Si–Ti alloys. The rigorous approach provides an extension of the applicability range of the concept of Q. The qualitative similarity of inoculant particles and primary intermetallic phases is verified by calculations for Al–Si–Ti–B alloys.

Evaluation concepts for theGrowth Restriction Factor, Q, in multicomponent alloys are discussed and illustrated for ternary Al-Si-Ti alloys involving precipitation of primary intermetallic phases.

Experimental work is done and combined with the Calphad method to generate a consistent thermodynamic description of the Mg–Ca–Si–Sn quaternary system, validated for Mg-rich alloys. The viability of a procedure for the selection of multicomponent key samples is demonstrated for this multicomponent system. Dedicated thermal analysis with DTA/DSC on sealed samples is performed and the microstructure of slowly solidified alloys is analyzed using SEM/EDX. The thermodynamic description and phase diagram of the ternary Mg–Si–Sn system, developed in detail also in this work, deviates significantly from a previous literature proposal. The phase formation in ternary and quaternary alloys is analyzed using the tool of thermodynamic equilibrium and Scheil calculations for the solidification paths and compared with present experimental data. The significant ternary/quaternary solid solubilities of pertinent intermetallic phases are quantitatively introduced in the quaternary Mg–Ca–Si–Sn phase diagram and validated by experimental data.

The phase relationships in the Mg-rich corner of the Mg-Ce-Nd system have been investigated through the evaluation of selected compositions in the as-cast and heat-treated condition. Consistent thermodynamic CALPHAD-type assessments have also been generated for the Mg-Ce-Nd system [1].

The Mg-rich part of the ternary Mg–Zn–Ce system was investigated by key samples to determine the solubilities, primary crystallization and invariant reactions. Ten alloys were prepared from pure elements and investigated by DTA/DSC and SEM/EDS. A consistent thermodynamic model of the ternary Mg–Zn–Ce system is developed for the first time by using the Calphad method. Phase diagram sections at constant 300 °C, at constant 85 at.% Mg and the liquidus projection of the Mg–Zn–Ce ternary system were calculated and compared with all available experimental data. The thermodynamic description is reasonably well supported by experimental data, especially in the Mg-rich region.

In this paper an overview of the most relevant phase diagrams is given comprising the unconventional alloying elements Sn, Ca, and Sr, in reasonable combinations with Al and Mn in Mg alloys as a basis for advanced applications. The focus is on magnesium-rich partial projections of the liquidus surface of five ternary systems, relevant to technological applications for lightweight materials. All phase diagrams are calculated from a coherent thermodynamic multicomponent database for magnesium alloys. These calculations are validated by key samples in the pertinent subsystems, including extensive ternary assessments and also quaternary work. Isothermal sections of magnesium-rich phase diagrams of alloys with constant aluminum and manganese content at 500°C and 550°C are given for the two five-component systems: Mg-Al-Mn-Ca-Sr and Mg-Al-Mn-Ca-Sn.

The phase equilibria of the Mg–Sn–Ca system for the entire composition and temperature ranges have been clarified based on the Calphad method. To obtain a reliable thermodynamic description, we performed key experiments for the phase boundary data and also utilized the first-principle results of the finite-temperature properties for the binary and ternary compounds. Experimental works for the phase equilibria, which consist of thermal, crystallographic and microstructural analyses, and the thermodynamic modeling combined with finite-temperature first-principle calculations are reported. The satisfying agreements between the experimental and calculated results support the reliability of the proposed thermodynamic description. The phase diagram for overall composition and temperature ranges of the ternary system based on the thermodynamic calculations is presented. In a second study this result is applied to obtain details of the phase formation during solidification for practically important Mg-rich as-cast alloys.

Experimental work using differential scanning calorimetry, differential thermal analysis, X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray analysis was conducted on key samples with more than 33 at.% Mg in the Mg-Al-Sn system. In addition to the thermal analysis and study of the solidification microstructure, an equilibration at 400 °C was performed. The results were used together with all available phase equilibria and thermodynamic data from earlier experimentation to create a consistent thermodynamic description of the Mg-Al-Sn alloy system. No ternary stable phase was discovered, and no ternary solubilities of the binary intermetallic phases were found. With the addition of a single Gibbs energy parameter describing the interaction between Al and the associate Mg2Sn in the liquid phase, the thermodynamic model of the system could be made to describe all pertinent experimental data throughout the ternary system. The phase precipitation sequence during slow solidification of all present samples is reflected by the thermodynamic calculations as well. Intricate details of the liquid miscibility gap, occurring in ternary alloys only, are also highlighted.

Thixomolding, as a semisolid processing approach, offers a unique opportunity to produce new Mg-alloys by mixing different feedstock chips at room temperature. This way of blending or mixing two or more commercially available standard Mg alloys will produce a new alloy with different melting range, solidification path, phase distribution and metallurgical and mechanical properties. This paper demonstrates the applicability of thermodynamic modeling to generate detailed information about phase formation in thixomolding process. For this purpose the process is pictured by appropriate thermodynamic calculations using a multicomponent Mg alloy database.

New ternary intermetallic compounds Sm2Ga7� xGex (x ¼ 5:226:1) and Sm4Ga11� xGex (x ¼ 5:7628:75) were synthesized and their crystal structures were determined by X-ray powder diffraction at compositions Sm2Ga1.8Ge5.2 and Sm4Ga5.24Ge5.76 .S m 2Ga1.8Ge5.2 crystallizes with the Ce2(Ga0.1Ge0.9)7 type of structure (space group Cmce, Pearson code oS80–8.00, a ¼ 8:46216ð13Þ, b ¼ 8:15343ð13Þ, c ¼ 21:1243ð3Þ ˚

Experimentally validated thermodynamic descriptions have been developed for the ternary Mg-La-Ce, Mg-La-Nd, and Mg-Ce-Nd systems by selecting key alloys in both systems and analyzing the phase formation in both the as-cast and heat treated state by SEM/EDS and DSC. These results were combined to form the validated thermodynamic Calphad-type description for quaternary Mg-La-Ce-Nd alloys. It is shown that for these light rare earth elements (La, Ce, Nd) the intermetallic phases with Mg exhibit significant mutual solid solubility in the ternary systems, extending into the quaternary alloy system. This is reflected by considering the shared crystal structures in the thermodynamic modeling. Simulated solidification paths of three Mg-La-Ce-Nd alloys with different La:Ce:Nd ratios and a common total content of 5 wt.% rare earth (RE) metals are evaluated using computational thermodynamics. Unexpected and distinctly different solidification behavior of these three alloys is revealed. The sequence La→Ce→Nd in the periodic table is not at all reflected in a monotonous solidification behavior. The demonstrated individual impact of each of these elements forbids treating the RE additions as a mere wt.% sum of RE elements.

The Mo-Nb binary system, as accepted from [Mas2], shows complete solubility in the liquid and solid states which relates to the same bcc structure of the pure elements. The Nb-Si and Mo-Si systems were accepted from [Mas2], based on the reviews by [1991Gok] and [1993Sch], taking into account one adaptation of the latter. Since it appears from revision of MoSi 2 -TiSi 2 and MoSi 2 -TaSi 2 phase diagrams by [1992Boe] that $MoSi 2 is metastable, the polymorphic transformation from "MoSi 2 to $MoSi 2 was rejected. The stability region of "MoSi 2 is thus extended up to 2020°C. [2000Liu] and [2002Fer] thermodynamically modeled respectively the Mo-Si and the Nb-Si systems. Solid Phases No ternary compounds have been reported in the literature. Crystallographic data on all solid phases is given in Table 2. The solubility of Nb and Mo in the binary phases of the complementary binary system have been investigated, focusing mainly on the quasibinary sections NbSi 2 -MoSi 2 and Nb 5 Si 3 -Mo 5 Si 3 which are treated in subsequent section. For (Nb x Mo 3–x )Si [2000Ma] measured a solubility of 23.6 at.% Nb at 1700°C which is in line with the investigation by [1975Wat]. Quasibinary Systems Two quasibinary sections have been identified in the Mo-Nb-Si system, respectively NbSi 2 -MoSi 2 and Nb 5 Si 3 -Mo 5 Si 3 . In the former [1964Gla] determined with XRD a solubility of 22 at.% Mo in " 2 (Nb 1–x Mo x )Si 2 and 4 at.% Nb in " 1 (Nb x Mo 1–x )Si 2 for samples which had been annealed for 1500 h at 800°C. Later measurements yielded a smaller Nb solubility of about 1.3 at.% [1994Har, 1994Yos, 2001Wei, 2005Yan2] and a larger Mo solubility of 27 at.% at 1200°C [1994Yos, 2005Yan2]. An even smaller Nb solubility was measured by [1998Yi] though he analyzed as-cast alloys without further treatment. The original proposed diagram by [1965Sav] exhibits an invariant eutectic reaction which was also claimed to take place by [1964Gla] without giving any further evidence. On the other hand [1998Nak] expected a peritectic reaction based on the similarity between the NbSi 2 -MoSi 2 and the MoSi 2 -TaSi 2 systems, which was supported by [2001Wei] and confirmed by [2005Yan2] who observed a typical peritectic like microstructure in arc-melted (Mo 1–x Nb x )Si 2 alloys. The proposed peritectic NbSi 2 -MoSi 2 section conform the solubility data of the more recent investigations with limited Nb solubility in " 1 (Nb x Mo 1–x )Si 2 is shown in Fig. 1. The top of the diagram is tentative as [2001Wei] could only perform DTA measurements up to 1650°C.

The basis of this work is a detailed investigation of phase equilibria of the Mg–Sn–Ca system for wide ranges of composition and temperature by means of a combined approach of our own key experiments, first-principles calculations of finite-temperature properties of the compounds and Calphad-type modeling. In this report, the generated thermodynamic description is applied to predict the phase formation and discuss the solidification behavior of practically important Mg-rich alloys. Solidification calculations, based on computational thermochemistry and the present dataset, are successfully applied to the analysis of experimentally observed as-cast microstructures and thermal analysis data for the Mg-rich alloy samples.