A thermodynamic assessment of the Co–Sn system

A critical evaluation and thermodynamic modeling of the phase diagram and thermodynamic properties have been presented for the Co–Sn system. More attention has been paid to reproduce the thermodynamic properties of the liquid Co–Sn, including the appreciable temperature dependence in the mixing enthalpy and the sign-variable activity with composition observed by experiments. A four-sublattice model has been used to describe the ordering phenomenon between $\beta {\mathrm{Co}}_3{\mathrm{Sn}}_2$ and $\alpha {\mathrm{Co}}_3{\mathrm{Sn}}_2$.     

A thermodynamic modeling of the Cu–Pd system

The phase equilibria and thermodynamic properties of the Cu–Pd system are optimized using the CALPHAD (CALculation of PHAse Diagram) technique. In the present work, the liquid and face-centered cubic (fcc) solution phases are modeled with the substitutional solution model. A two-sublattice model (Cu,Pd)_0.75(Cu,Pd)_0.25 is applied to describe the ordered Cu₃Pd phase, the one-dimensional long-period superlattice (1D-LPS) and two-dimensional long-period superlattice (2D-LPS) structures, in order to cope with the order–disorder transition between three intermetallic compounds (Cu₃Pd, 1D-LPS and 2D-LPS) and fcc solution (A1) in the Cu–Pd system. A two-sublattice model (Cu, Pd)(Cu, Pd) is used to describe the homogeneity range of CuPd phase. A set of self-consistent thermodynamic parameters is obtained and the calculated phase diagram and thermodynamic properties are presented and compared with the experimental data.     

Thermodynamic re-assessment of the Mg–Y binary system coupling with the precipitation sequence during aging process

The experimentally observed aging precipitation sequence of the Mg–Y alloys from literatures is α(Mg)_SS(supersaturated)→ β''(c-bco like GP zones)→ β′(c-bco, metastable coherent Mg₇Y)→ β(bcc, stable incoherent Mg₂₄Y₅). Compared with the equilibrium phase diagram, Mg₇Y is not a stable precipitate, but from the view point of the crystal structure, Mg₇Y is an ordering product of HCP_A3(Mg). The Mg–Y binary system has been thermodynamically re-assessed by means of CALPHAD technique in order to study its aging precipitation sequence in the present work. Three solution phases, HCP_A3, BCC_A2 and Liquid, are modeled with the Redlich-Kister polynomial. The intermetallic compounds Mg₂Y and Mg₂₄Y₅ have been described by the following formulas, (Mg, Y)_0.6667(Mg, Y)_0.3333 and Mg_0.8276(Mg, Y)_0.1379 Y_0.0345, respectively. Especially for order-disorder transitions, the following two-sublattice models (Mg, Y)_0.5(Mg, Y)_0.5 and (Mg, Y)_0.875(Mg, Y)_0.125 have been used to describe the stable MgY/BCC_A2 and the metastable Mg₇Y/HCP_A3, respectively. Based on the satisfied optimization of equilibrium phase diagram, the order-disorder transition between the metastable intermediate Mg₇Y and the stable phase HCP_A3 is assessed to ensure that Mg₇Y has a big enough driving force but not a lowest Gibbs free energy change to precipitate preferentially from the supersaturated α(Mg). Meanwhile, in order to match the aging precipitation sequence of the Mg–Y alloys, the effective nucleation driving forces for the precipitated phases are calculated by subtracting the interfacial energy and the elastic strain energy from the thermodynamic driving force. A set of self-consistent thermodynamic parameters has been obtained to agree satisfactorily with the reported experimental data from literatures, including the phase diagram, the thermochemical properties, and the aging precipitation sequence of the typical Mg–Y alloys with x(Y) = 0.0232 at 473 K.     

A benefit–cost perspective of the consumer adoption of the mobile banking system

The present research adopts a benefit–cost perspective to study consumer adoption of the mobile banking services. It is suggested that because of the specific product context of the mobile banking service, such as the difficulty to assess some experiential qualities like the ease of use due to a low trial rate of mobile banking and the inherent risk factor involved in a new financial service technology, models complementary to the technology adoption model may be needed to accommodate these product contexts. In the present research, the benefit–cost framework was employed as an example of the complementary framework to study consumers' adoption of the mobile banking system. The key benefit of mobile banking is convenience, while the key cost is security. A set of ability and risk factors were modelled via structural equation model (SEM) as the antecedents of the benefit and cost of adopting the mobile banking system. The results showed that the empirical data supported most hypothesised relationships among the factors. It is concluded that consumers' new technology adoption behaviour is a complicated phenomenon which may require different models in different product contexts. It is suggested that future research should address the issue of the preconditions and product contexts under which a certain class of models may be most suitable to explain the adoption behaviour.     

A thermodynamic evaluation of the FeMoC system

A new evaluation of the Fe-Mo-C system has been made using a sublattice model and including the magnetic effect. A set of parameter values describing the Gibbs energy of each individual phase was determined with a computerized optimization technique. It gives satisfactory agreement with the experimental information over a wide temperature range. Several diagrams and tables concerning phase equilibria are presented.     

A thermodynamic description of the Gd–Mg–Sm system

The Mg–Sm, Gd–Sm and Gd–Mg–Sm systems were thermodynamically optimized using the CALPHAD technique. The solution phases, liquid, bcc, hcp and rhombohedral, were described by the substitutional solution model. The isostructural compounds, MgGd in the Gd–Mg system and MgSm in the Mg–Sm system with a B2 structure was assumed to form a continuous range of solid solutions in the Gd–Mg–Sm system. The order–disorder transition between the bcc solution with an A2 structure and compound Mg(Gd, Sm) with a B2 structure in the system has been taken into account and thermodynamically modeled. The other isostructural compounds Mg₅Gd and Mg₅Sm, Mg₃Gd and Mg₃Sm, Mg₂Gd and Mg₂Sm in the Gd–Mg–Sm system were described according to the formulae Mg₅(Gd,Sm), Mg₃(Gd,Sm), and Mg₂(Gd,Sm), respectively. The compound Mg₄₁Sm₅ with a homogeneity range was treated as a line compound Mg₄₁(Gd,Sm)₅ in the Gd–Mg–Sm system. Based on the experimental data in the Mg-rich corner of the Gd–Mg–Sm system, a set of thermodynamic parameters describing the Gibbs energies of individual phases of the Gd–Mg–Sm system as functions of composition and temperature was obtained. In addition, the complete ternary phase diagram of the Gd–Mg–Sm system were predicted.     

On the cardinal number of complete sets of Boolean operations†

It is shown in the literature (using the Post—Yablonsky theorem) that a complete set of Boolean operations cannot have a cardinal number greater than four. It is the object of this paper to improve this bound and prove that a complete set can have a cardinal number of at most three or, in other words, there does not exist a complete (non–redundant) set of more than three Boolean operations. The proof given here is constructive, using the Post—Yablonsky theorem, truth tables and combinatorial set theory.     

Refinement of the thermodynamic modeling of the Nb–Ni system

The Nb–Ni system is reassessed on the basis of a critical literature review involving recent experimental data. These newly published experimental data include the phase relation associated with the NbNi₈ phase, phase transition temperatures resulting from selected alloys, all invariant reaction temperatures, and enthalpies of mixing of liquid, as well as the crystallographic data on the μ$\mu$ (Nb₇Ni₆) phase. A consistent thermodynamic data set for the Nb–Ni system is obtained by optimization of the selected experimental values. The calculated phase diagram, crystallographic properties and thermodynamic properties agree reasonably with the experimental data. Noticeable improvements have been made, compared with the previous thermodynamic optimizations.     

A new algorithm of bearings-only multi-target tracking of bistatic system

Much research mainly focuses on the batch processing method （e.g. maximum likelihood method） when bearings-only multiple targets tracking of bistatic sonar system is considered. In this paper, the idea of recursive processing method is presented and employed, and corresponding data association algorithms, i.e. a multi-objective ant-colony-based optimization algorithm and an easy fast assignment algorithm are developed to solve the measurements-to-measurements and measurements-to-tracks data association problems of bistatic sonar system, respectively. Monte-Carlo simulations are induced to evaluate the effectiveness of the proposed methods.     

Kilowhat? A multidisciplinary approach on the development of a home energy management system

To a consumer, knowing how much energy you use is often a question mark. We get our energy bills and more often than not, they are surprisingly high. The coming of the smart grid and more specifically smart metering provides opportunities to create a better awareness on energy use among consumers. This research presents the user-centric development of a home energy management system. The focus of the research is not specifically on the functionalities per se, rather it lies on the inclusion of the energy end-user in the development process. Throughout the development, end-user research provided valuable input for the development of the system. Large quantitative surveys were alternated with small scale in-depth qualitative research. Each step generated the input for the next step in the research process, resulting in a system with functionalities tailored to the end-users needs and wants.     

A thermodynamic assessment of Ni–Sb system

The Ni–Sb system was critically assessed by means of the CALculation of PHAse Diagram (CALPHAD) technique. The solution phases, Liq and (αNi), were modelled as the substitutional solutions with the Redlich–Kister equation. The intermediate phases, (γNiSb) and (βNi₃Sb), with homogeneity ranges were described respectively using three-sublattices (Sb)_1/3(Ni%,V a)_1/3(V a%,Ni)_1/3 and (Sb)_1/4(Ni%,V a)_1/2(Ni%,V a)_1/4 based on their structure features. Corresponding to the phase (βNi₃Sb), the two low-temperature phases of (δNi₃Sb) and (θNi₅Sb₂) with narrow homogeneity ranges were modelled as two-sublattice, (Ni)_3/4(Sb,Ni)_1/4 and (Ni)_5/7(Sb,Ni)_2/7. The intermetallic compound ζNiSb₂ with no homogeneity ranges was treated as stoichiometric compound. The phase ε$\epsilon$Sb was considered as pure Sb for the solubility of Ni in ε$\epsilon$Sb is very low. A set of self-consistent thermodynamic parameters of the Ni–Sb system was obtained. The optimized phase diagram and thermodynamic properties were presented and compared with experimental data.     

Thermodynamic description of the Ti–H system

Previous thermodynamic assessments of the Ti–H system are reviewed, and a new evaluation is carried out by taking into account the liquid phase in the system using the associate solution model. The sublattice model is utilized to depict the interstitial solution phases with various lattice ratios. The model parameters are optimized in the least square procedure by selecting most reported equilibrium solubility and thermochemical data of the Ti–H system. It is demonstrated that a credible set of thermodynamic parameters well describing the whole Ti–H system is obtained. With these parameters, the behavior of the Ti–H system was predicted at higher pressures of 10, 100 and 370 atm.     

Thermodynamic modeling of the ZrO system

In this study, the complete zirconium-oxygen system has been critically assessed at 1 at. from 300°C to liquidus temperatures. Thermochemical measurements and phase diagram data were used to model the Gibbs free energies of seven phases. Additionally, the ordered interstitial HCP-based solutions were included and considered as simple line compounds. By using the PARROT module in Thermo-Calc, it was possible to optimize the parameters of the models used to describe the Gibbs free energies of the HCP, BCC, Liquid, γ ZrO_2−x,β ZrO_2−x and α ZrO_2−x phases. The Gas phase was considered to behave ideally. Although phase diagrams including the stoichiometric zirconia phases have been assessed, this is the first time, to the best of our knowledge that a complete assessment of this system is published.     

Thermodynamic modeling of the C–Pu system

The thermodynamic modelling of the binary C–Pu system was performed in the framework of the development of a thermodynamic database for nuclear materials, for increasing the knowledge of the physico-chemical behaviour of the fuel and surrounding materials implicated in GFR (gas cooled fast reactor) systems. The critical assessment was carried out using the CALPHAD approach, based on available experimental data on phase diagram and thermodynamic properties of the solid phases.     

Thermodynamic assessment of the Ag–Ga system

The thermodynamics of the Ag–Ga system are assessed by the CALPHAD approach (calculation of phase diagram). The liquid phase, the solid solution phases of fcc (α$\alpha$-Ag) and hcp (ζ)$\left(\zeta \right)$, the solution compound Ag₂Ga (ζ^′)$\left({\zeta }^{\prime }\right)$, the stoichiometric compound Ag₃Ga₂, and the terminal phase of orthorhombic Ga are taken into consideration in this optimization. The liquid phase is described by the association model. The subregular solution model is used for the solid solution phases of fcc and hcp. The solution compound Ag₂Ga is described by the two-sublattice compound energy model (CEM). A set of self-consistent thermodynamic parameters is obtained and the calculated phase diagram and thermodynamic properties are presented and compared with the experimental data from literatures.