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Most phase change materials employed in latent heat thermal energy storage suffer from poor thermal conductivity both in liquid and solid phases, leading to low heat transfer effectiveness. To overcome this limitation, multiple PCMs and gradient copper foam have been used to accelerate the melting of phase change materials and improve the heat transfer effectiveness. The heat transfer performance of shell-and-tube thermal energy storage unit consisting of radial multiple PCMs and single PCM was numerically investigated. The utilization of single PCM showed better heat transfer effectiveness compared to that using radial multiple PCMs. The time saving for complete melting was up to 87.5%. The results implied that the radial multiple PCMs have no advantage in thermal storage compared to single PCM. Based on single PCM system, three types of gradients of copper foam, named positive gradient, non-gradient and negative gradient were designed in this study. The results indicated that the negative gradient type offers better heat transfer effectiveness than the non-gradient and positive gradient types. However, the temperature distribution of non-gradient type was more uniform compared to positive and negative types. Besides, an optimal configuration 0.99–0.97-0.89 of negative gradient was recommended to further reduce the complete melting time by 23.7%.

Metal–organic frameworks (MOFs) have attracted a special attention due to outstanding porosity, adjustable pore sizes, and huge opportunities in varying organic–inorganic compositions. Enormous studies conducted so far on MOFs indicate their high potential in catalysis, gas adsorption, drug delivery, water treatment, energy storage, among others. However, mass production of MOFs is still limited mainly due to the non-economic, non-green and complex synthesis methods. Mechanochemistry is an alternative solution for efficient and environmentally friendly syntheses of various MOFs. Fast and solvent-free or solvent-less mechanosynthesis seems to be a very powerful versatile method for obtaining these advanced porous materials. The mechanochemical concept was used for the preparation of various MOFs including the most popular structures: MOF-5, ZIF-8, HKUST-1, MIL-101, UiO-66. These MOFs feature high specific surface areas, comparable to those prepared by conventional solvent-based methods. Furthermore, mechanochemistry was successfully used for the synthesis of non-conventional multimetallic MOFs and previously unreported solid phases. This review shows the recent developments, challenges and perspectives of green synthesis of diverse MOF structures using mechanochemistry. Besides describing the mechanochemical synthesis of MOFs, some achievements in green applications are also summarized. Importantly, current trends in research suggests for further development of these fields i.e., harmful gas adsorption, water treatment, and energy storage.

Thermocline storage performance is studied using a numerical model with three phases (fluid, solid, wall) and one dimension, which is then validated by comparison with experimental results. The impact of the interstitial fluid velocity on storage performance is presented and numerical simulations show the existence of an optimal velocity of 4 ⋅ 10−4 m s−1 that maximises the storage utilisation rate (80.6%) for ideal charges between 293 °C and 393 °C. This optimal velocity remains identical when the temperature level of the storage is shifted down and slightly increases to 4.8 ⋅ 10−4 m s−1 when the temperature difference is decreased by half (343°C–393 °C). A numerical sensitivity analysis is presented on the impact of heat losses, of thermal diffusion and of the convective heat transfer between the fluid and the solid phases, providing a physical interpretation of the location of the optimum depending on operating conditions. Experimentally, the impact of fluid velocity is too moderate to observe an optimal velocity, especially because of non-ideal inlet temperature conditions, but a deterioration of storage performance is observed at the lowest and highest velocities, with respectively −2.8% and −3.8% compared to the maximal utilisation rate. This moderate influence of both fluid velocity and temperature shows that thermocline storage presents good robustness of its performance to variations in operating conditions.

In this article, an acid-responsive luminescent material, 1,4-di(quinoline-6-yl)buta-1,3-diyne (DQBD) is designed and synthesized. Upon different pH values, gradual changes of fluorescence colors for DQBD in both solution and solid phases are demonstrated due to the protonation effect. Moreover, such responsive characteristics can also be reversible, suggesting DQBD as a promising fluorescent material with great potential for reusable- and accurate-pH sensors in the future.

The poor sintering performance of limonitic laterite hinders its utilization. Hot exhaust-gas recirculation sintering was conducted to improve its sintering performance and intensification mechanism was revealed. Evaluating sinter indices in systematical sinter pot tests were substantially improved with tumble index and productivity increased by 18.01% and 7.22% respectively and solid fuel rate lowered by 13.71%, further proved by extensive industrial application. Effective CO2 emissions reduction and huge economic benefits were realized. The improvement of thermodynamic conditions converted sinter microstructure from large thin-wall pores into small thin-wall or large thick-wall pores. The amount of silico-ferrite of calcium and alumina in sinter pot tests and industrial application was increased from 8.78% to 18.61% and 21.25% respectively. Grains aggregation and growth of hercynite and close adhesion between solid phases and liquid bonding phases were achieved. Hot exhaust-gas recirculation sintering of limonitic laterite contributed to dramatically improving sinter performance and reducing CO2 emission.

Shear thickening electrolytes and magneto-rheological electrolytes can reversibly switch between liquid and semisolid or even solid phases at specific conditions. They afford the advantages of both liquid and solid electrolytes and have the potential to enhance impact resistance of electronic devices. This review presents the recent progress of such electrolytes. It aims to provide insights into the properties and performance. We also present the challenges in producing high-performance electrolytes and the future perspectives.

Selective Laser Melting (SLM) – as one of a number of additive manufacturing techniques – is a promising method for the manufacturing of complex structures and may bring about significant improvements in the context of custom-made designs and lightweight constructions. However, the complex multiphysical processes occurring during SLM necessitates the establishment of appropriate constitutive and process models in order to quantitatively predict the properties of the final workpiece. In particular, the accurate determination of process-induced eigenstresses is a challenging yet important task. In this work, a constitutive modelling framework stemming from phase transformations in shape memory alloys is adopted to the modelling of the changes of state during SLM. This model is based on energy densities and energy minimisation in general and specifically serves as a basis for further enhancements such as the consideration of multiple solid phases of the underlying material. This is particularly considered important due to the fact that the cooling rates during SLM are heterogeneously distributed and that thus different solid phases may form out of the molten material pool. As a first step, the present overall model comprises three phases of the material, namely powder, molten, and re-solidified material. The thermomechanically fully coupled Finite-Element-based process model incorporates approaches for, e.g., the laser beam impact zone and the layer construction model.

Silver dimetal chalcogenides ternary semiconductors are commonly obtained by complex and difficult synthetic process, such as high temperatures (~1100 K), long reaction times and mixture heterogeneity involving solid phases. Here, we present a facile aqueous synthesis route for the preparation of AgBiSe2 nanoparticles at low temperature (~373 K). The as-synthesized AgBiSe2 nanoparticles possess narrow size distribution (ca. 80 nm) and excellent light absorbance across the entire UV/Vis region. More important, AgBiSe2-based devices exhibit a reduced resistance of 0.53 ​Ω*m and markedly 50% improved absorption efficiency under monochromatic light after heating treatment. These results may potentially be extended for the preparation of other ternary semiconductors.

The phase diagrams of the Mg(NO3)2–Ln(NO3)3 (Ln = Nd, Sm, Eu, Tb)–HNO3–H2O systems in the (∼20%) HNO3 regions at T = 298.15 K were determined by using an isothermal solution saturation method. The Schreinemaker’s wet residues method was used to determine the compositions of solid-phases. Both Mg(NO3)2–Nd(NO3)3–HNO3–H2O and Mg(NO3)2–Sm(NO3)3–HNO3–H2O systems are complicated with three equilibrium solid phases Mg(NO3)2·6H2O, Mg3Ln2(NO3)12·24H2O and Ln(NO3)3·6H2O (Ln = Nd, Sm). But the systems Mg(NO3)2–Eu(NO3)3–HNO3–H2O and Mg(NO3)2–Tb(NO3)3Tb–HNO3–H2O are simple eutonic type. The two new solid-phase compounds Mg3Nd2(NO3)12·24H2O and Mg3Sm2(NO3)12·24H2O are congruently soluble in an average medium of ∼20 mass % HNO3, and they were identified and characterized by the methods of powder X-ray diffraction, X–ray diffraction single crystal structure analysis, and thermogravimetric/differential thermogravimetric. The XRD diffraction patterns for the two new solid-phase compounds are identical due to their isomorphic structure. They belong to hexagonal systems, with space group R3. For Mg3Nd2(NO3)12·24H2O, a = b = (1.0993 ± 0.0005) nm, c = (1.7211 ± 0.0007) nm, V = (1.8012 ± 0.0013) nm3, Dc = (4.2532 ± 0.0024) g·cm−3, Z = 3; for Mg3Sm2(NO3)12·24H2O, (a = b = 1.1198 ± 0.0004) nm, c = (1.7257 ± 0.0006) nm, V = (1.8742 ± 0.0011) nm3, Dc = (4.1201 ± 0.0012) g cm−3, Z = 3. The standard molar enthalpies of solution of the compounds Mg3Nd2(NO3)12·24H2O and Mg3Sm2(NO3)12·24H2O in water (aq) were measured to be (101.26 ± 0.77) kJ mol−1 and (80.27 ± 0.81) kJ mol−1, and their standard molar enthalpies of formation were calculated to be – (12214.13 ± 2.5) kJ mol−1 and – (12183.6 ± 2.5) kJ mol−1, respectively.

Algorithms for solid-liquid equilibrium (SLE) calculations are essential tools for describing physical properties of food systems and for developing formulations of new food products. In this work, SLE was applied to describe the melting behavior of edible fats of relevance to the food industry. The original UNIFAC method and a predictive version of the UNIQUAC model [Coutinho, Ind. Eng. Chem. Res., 37 (1998) p. 4870–4875] were used to calculate compounds’ activity coefficients for both liquid and solid phases. Equilibrium and mass balance equations were solved using a solid-liquid version of the well-known isoenthalpic flash algorithm and the predictive ability of the method was tested for describing solid fat content (SFC) curves of selected fats. In the case of the UNIQUAC model, global structural parameters were also fitted in order to best represent triacylglycerol (TAG) molecules in the solid phase, allowing a general discussion about the use of experimental data for improving the modeling approach. Reasonable quantitative agreement between predictions and experimental data were achieved revealing the necessity of considering the nonideality of both liquid and solid phases in the subject of oils and fats cristallization. The modeling approach presented here is particularly interesting for developing new fat-based product formulations, being a valuable alternative to costly and time consuming experimental approaches.

International audience; This study evaluates binding discs based on 3-mercaptopropyl-functionalized silica gel for the selective sampling of selenite (Sew) using Diffusive Gradients in Thin films sampler (DGT). Selv accumulation was quantitative and selective over Sew and followed the theoretical linear accumulation with the exposure time up to 0.7 pg. The sampling was not affected by ionic strength variations down to 10-2 mol L-1 (as NaNO3) but Sew accumulation was found to decrease significantly for pH greater than 5 and was nearly zero at pH 9. Both the limited accumulation range and the pH dependence were unexpected because they have not been reported in the literature related to the Se"' trapping by thiol-based solid phases. Our experiments showed that after Sew was bound to thiol functional groups, a further pH-dependent reaction occurred with free thiols, resulting in the reduction of Sew into elemental selenium (Se) followed by its release and back-diffusion through the DGT sampler. Unfortunately, such a reversible accumulation is incompatible with the implementation of the mercapto-functionalized silica binding phase in DGT devices for Sew selective sampling.

The Al2O3-MgO-TiO2 system has been assessed with the CALPHAD approach, taking into account the recent experimental data and its compatibility with the available descriptions of the Al2O3-TiO2, Al2O3-MgO, and MgO-TiO2 systems. Two of the solid phases, spinel and pseudobrookite, form continuous solid solutions at high temperatures and have been modelled using the compound energy formalism. The cation disordering in both spinel and pseudobrookite have been considered. For the liquid phase, the two-sublattice partially ionic model has been applied. The thermodynamic parameters have been evaluated to describe the experimental data in the whole compositional range of the system.

Most research into the formation of the lamellar eutectics has focused on the growth patterns. However, those growth patterns can be attributed to the behavior of the triple junction, at which the solute distribution determines the long-range spatial periodicity of patterns. From both theoretical validation and phase-field simulations, we characterize the solute concentration at the triple point and demonstrate the existence of abnormal solute distribution. The solute concentration at the triple point equals the eutectic concentration only when the coexisting solid phases are evenly distributed, which is essential to balance the concentration gradient and maintain the interfacial thermodynamic equilibrium.

In this paper, a three dimensional Eulerian–Eulerian simulation, for the vertical heater wall to bed heat transfer in a cylindrical fluidized bed, was conducted numerically with the results compared to the experimental ones. In this process, the understanding of the heat transfer mechanism of gas-solid flow in the fluidized bed is deepened, which provides a reference for the design and operation of practical fluidized bed burner equipment. Gidaspow's drag correlation was adopted to describe the interaction between the gas and the solid phases in the fluidized bed. Moreover, a user-defined function (UDF) of the gas-solid inter-phase exchange coefficient was derived obtain the temperature and heat transfer characteristics in the fluid area, with different particle shapes. Temperature and heat transfer coefficient were numerically analyzed under different operating conditions that are consistent with the experimental setups. The effects of initial solid packing height onto the heat transfer characteristic, together with the average total and convective heat transfer coefficient, were investigated, where the average temperature was compared with the experimental data in the literature. The simulation results showed that the average temperature and heat transfer coefficient well agree with the experimental data, and the average heat transfer coefficient is increased by about 60% with the increasing initial solid packing height. Therefore, it is essential to obtain the distribution of temperature in annular horizontal cross-section as well as solid flow characteristics with the varying time for comprehensive understanding of the heat transfer process. The instantaneous variations between the local heat transfer coefficient and the solid volume fraction were analyzed under different gas inlet velocity.

High Entropy Alloys (HEAs) are an increasingly dominant alloy design paradigm. The premise of entropic stabilization of single-phase alloys has motivated much of the research on HEAs. Chemical complexity may indeed help stabilize single alloy phases relative to other lower-entropy competing solid phases. Paradoxically, this complexity may de-stabilize these alloys against the liquid, potentially limiting the application space of HEAs at elevated temperatures. In this work, we carry out a comprehensive investigation of the phase stability in the fcc CoCrFeMnNiVAl HEA space using a state of the art CALPHAD database. By using modern

A procedure combining supercritical CO2 and ultrasound-assisted (USC-CO2) extraction was developed to obtain rosmarinic acid (RA)-rich extracts from Perilla frutescens. Based on extraction yields and efficiencies, USC-CO2 was considered the best extraction method among the methods studied for obtaining RA from P. frutescens. The constant extraction rate period and the falling extraction rate period for USC-CO2 extraction of P. frutescens were 45 and 96 min long, respectively, and they were significantly shorter than those of traditional SC-CO2 (TSC-CO2) extraction. Furthermore, mass transfer coefficients were derived using the Sovova model for the fluid and solid phases from USC-CO2 extraction, with values of 9.752 × 10−3 and 4.203 × 10−3 min−1, respectively, which were obviously higher than those for TSC-CO2 extraction. Consequently, the theoretical solubilities of RA in the supercritical solvents used in dynamic USC-CO2 and TSC-CO2 extractions were estimated and found to be well correlated using three density-based models.

High Entropy Alloys (HEAs) are an increasingly dominant alloy design paradigm. The premise of entropic stabilization of single-phase alloys has motivated much of the research on HEAs. Chemical complexity may indeed help stabilize single alloy phases relative to other lower-entropy competing solid phases. Paradoxically, this complexity may de-stabilize these alloys against the liquid phase, potentially limiting the application space of HEAs at elevated temperatures. In this work, we carry out a comprehensive investigation of the phase stability in the fcc CoCrFeMnNiV-Al HEA space using a state of the art CALPHAD database. By using modern visualization techniques and statistical analysis we examine the trade-off between chemical complexity and stability against the liquid state and identify a potentially difficult to overcome barrier for development of high temperature alloys, at least within the conventional fcc HEA space. Limited experimental data seem to be consistent with this analysis.

A new high-pressure equilibrium cell to obtain data for systems containing fluids and solids is presented. By using the static synthetic method, an experimental unit was commissioned to obtain phase transition data at pressures up to 1000 bar, and temperatures ranging from 253 to 473 K. Measured phase transition data include new data for liquid-vapor, liquid-liquid, liquid-liquid-vapor, solid-liquid, and solid-liquid-liquid of CO2 + n-hexadecane, CO2 + n-eicosane, and CO2 + n-tetracosane binary systems. Results are compared to those from literature and show that the new experimental cell setup presents a good performance and allows to explore regions where traditionally, accurate experimental data are scarce.

Steeply inclined settler technology has been long used to separate liquid and solid phases in dilute streams in various industries. In the present paper, a new model to account for the capacity of this kind of settler, in the particular case of those consisting of a set of inclined conduits, is proposed. The model combines a mass balance similar to that leading to the Ponder, Nakamura and Kuroda theory of inclined settlers and a particle trajectory approach to derive a simple relation between settling element length, particle settling-mean flow velocity ratio and geometric characteristics. Two new dimensionless parameters are derived to account for shape effects in the mass balance and when comparing settler capacity at equal conduit cross sectional area. Good agreement with previous experimental results and less conservative results than previous models have been found.

The emerging occurrence of thallium (Tl) in environments arouses the imposition of effective technology for its remediation. Due to the low solubility of Tl(III), the oxidation-precipitation of Tl(I) is considered as an promising removal method. Here, we recycled Al beverage can powder (AlCP) as the substitute for zero-valent Al to conduct the Fenton-like reaction for Tl(I) oxidation and subsequently induced the Tl(III) precipitation via the alkalinization at pH 9.5. The Tl(I) removal mechanisms in AlCP systems with amendments of Fe(III) or Fe(II) were determined in relation to its speciation for both dissolved and solid phases. Results showed that although additions of Fe(III)/Fe(II) prompted the Tl(I) oxidation as compared with the pure AlCP system, they were detrimental to the Tl removal upon the alkalinization. While the greatest removal efficiency was ~ 92% in AlCP/Fe(III)/Fe(II) systems, up to 99.8% of total Tl could be removed from the pure AlCP system. The Tl-XANES data indicated that although Tl(III) dominated the Tl inventory (92 – 95%) on all solids collected upon the alkalinization, it preferred to precipitate as stable Tl2O3 in pure AlCP system but as labile Tl(III) in AlCP/Fe(III)/Fe(II) systems, which might sorb on precipitated Al (hydr)oxides. Such sorbed Tl(III) is subject to reduction and the further dissolution, accounting for the lower removal efficiency for Tl in the presence of Fe(III)/Fe(II). This study corroborated the comparable Tl(I) removal efficiency of AlCP to that of state-of-the-art (nano)composites, providing a niche opportunity to give consideration to both interests in hazard remediation and the waste reduction/reuse.

Diffusive gradient in thin films (DGT) for organics has received considerable attention for studying the chemical dynamics of various organic pollutants in the environment. This review investigates current limitations of DGT for organics and identifies several research gaps for future studies. The application of a protective outer filter membrane has been recommended for most DGT applications, however, important questions regarding longer lag times due to significant interaction or adsorption of specific groups of compounds on the outer membrane remain. A modified DGT configuration has been developed that uses the diffusive gel as the outer membrane without the use of an extra filter membrane, however use of this configuration, while largely successful, remains limited. Biofouling has been a concern when using DGT for metals; however, effect on the performance of DGT for organics needs to be systemically studied. Storage stability of compounds on intact DGT samplers has been assessed in select studies and that data is synthesized here. DGT has been used to describe the kinetic desorption of antibiotics from soils and biosolids based on the soil/biosolid physical-chemical characteristics, yet applications remain limited and requires further research before wide-scale adoption is recommended. Finally, DGT for organics has been rarely, albeit successfully, combined with bioassays as well as in vivo bioaccumulation studies in zebrafish. Studies using DGT combined with bioassays to predict the adverse effects of environmental mixtures on aquatic or terrestrial biota are discussed here and should be considered for future research.

The thermal conductivity of even carbon number n-alkanes from n-dodecane to n-dotriacontane (C22H46 to C32H66) was measured in both the liquid and solid phases, in the temperature range from 297.15 to 353.15 K at 0.1 MPa. To assure the purity and map the solid phase of the different samples during the thermal conductivity measurements of the solid samples, the melting point, solid-solid transition temperature and their respective enthalpies were also evaluated. The thermal conductivity measurements for the liquid and solid samples were obtained within uncertainty levels better than 3% and 5%, respectively. To the best of our knowledge, this is the first report on the thermal conductivity of liquid n-hexacontane, n-octacontane, n-triacontane and n-dotriacontane, and, for solid samples, from n-docosane to n-dotriacontane.

The redox behaviour of uranium was investigated in 0.1 and 5.0 M NaCl solutions at 2 ≤ pHm ≤ 14.5 (pHm = –log [H+]) in the presence of different reducing chemical systems (Sn(II), Na2S2O4, Sn(II) + TiO2, Sn(II) + Fe(0), Sn(II) + Fe3O4). All experiments were performed under Ar atmosphere at T = (22 ± 2) °C. Uranium was added to independent batch samples as U(VI) (with [U]0 = 3.0⋅10−5 or 4.2⋅10−4 M), and the evolution of uranium concentration monitored for t ≤ 635 days. After attaining equilibrium conditions, [U] was found in all cases clearly below the solubility of U(VI) solid phases (UO3⋅2H2O(cr) or Na2U2O7⋅H2O(cr)) and in good agreement with the solubility of tetravalent UO2(am, hyd) as calculated with available thermodynamic data. This observation is in line with (pe + pHm) measurements, which in all cases fell in the stability field of U(IV). Solvent extraction and XANES confirmed also that uranium is predominantly found as U(IV) in the aqueous and solid phases investigated. No evidence on the formation of anionic hydrolysis species of U(IV) was obtained up to pHm = 14.5. Based on our long-term redox study, we conclude that previous investigations reporting the formation of U(OH)5– and U(OH)62− are possibly flawed by insufficient equilibration time, which prevented the complete reduction of U(VI) to U(IV). Our results further confirm that experimental pHm and Eh values measured in buffered systems can be considered as reliable parameters to predict the redox behaviour of U in dilute to concentrated NaCl systems.

Long-term storage of Fe(III)-As(V) co-precipitate wastes derived from the industrial As removal process poses the risk of secondary arsenic pollution to the local environment. However, its stability in only iron-reducing environment remains unclear. The effect of iron reduction by hydroquinone (QH2) on the stability of co-precipitate at Fe/As molar ratio of 5 was investigated in this study. The results showed that 16.5–93% of Fe(III) reduction in NaOH-neutralized co-precipitate caused 0.1–11% (0.1–8.5 mg L-1) As release and 0.9–46% (2.6–130 mg L-1) Fe(II) release at pH 4 and 6. Most of the As(V) and more than half of the Fe(II) generated by the reductive decomposition of Fe(III)-As(V) co-precipitate were retained in solid phases. Solid characterization and thermodynamic calculation indicated that amorphous Fe3(AsO4)2 was probably the major secondary mineral for As immobilization. At pH 8, 11–39% As and less than 4% Fe(II) were released into solution after 3.6–87% Fe(III) was reduced to Fe(II). Both amorphous Fe3(AsO4)2 and Fe(II,III) (hydr)oxides were responsible for As retention. The solubility of NaOH-neutralized co-precipitates in terms of dissolved As concentration upon Fe(III) reduction at pH 4, 6 and 8 with QH2/Fe(III) mol of 1 was lower than that in oxic environment. It was also lower than the solubility of Ca(OH)2-neutralized co-precipitate after Fe(III) reduction at pH 4 and 6.

Bioleaching of heavy metals from sewage sludge is an effective method for decontamination of sewage sludge. The process is currently under active investigation for its improvement of sewage sludge dewatering. The bioleaching with recirculation of the liquid and solid phases of sewage sludge is of considerable interest for the development of the bioleaching method itself, and for deeper investigation of its influence on the sludge dewatering. This work presents and verifies a mass balance model of elements for bioleaching of heavy metals from sewage sludge by indigenous iron-oxidizing bacteria with recirculation of the liquid phase of the treated sludge. Good correspondence between the model predictions and the performed experiments gives ground for further development of the model to describe substances that are not conserved during the bioleaching, especially extracellular polymeric substances that impede sewage sludge dewatering. The mass balance model is presented in a form that also describes recirculation of the solid phase of sewage sludge during the bioleaching. Recirculation of the liquid and solid phases of sewage sludge during the bioleaching, together with the mass balance model, give useful tools for future investigation and development of dewatering of sewage sludge with the use of the bioleaching process.

The phase relationships in silica rich area in the SiO2–SrO–Al2O3 system were determined experimentally at 1723 K (1450 °C), 1823 K (1550 °C) and 1873 K (1600 °C) using quenching technique. Phases of the quenched samples were examined and identified using light optical microscopy (LOM), scanning electron microscope (SEM) and energy dispersive x-ray spectroscopy (EDS). X-ray Diffraction (XRD) was used to confirm the presence of solid phases. Based on the experimental results, the liquidus projections in the silica rich area for the studied temperatures were constructed.

The purpose of this work was to theoretically and experimentally study the reactions that occur during low-pressure nitriding. A series of specimens made of 42CrMo4 and 41CrAlMo7 and C22 steels were low-pressure nitrided. The structure of the materials, the hardness and the thickness of the nitride layers, as well as any reactions that occurred in the gas and solid phases were tested. The process kinetics were discussed. The findings showed that a build-up of the nitrided layer from a low-pressure process depends on the kinetics of surface processes. However, a characterization of the process with nitriding potential is not justified and should be replaced with a rate of ammonia dissociation in low-pressure processes.

A coupled experimental investigation and thermodynamic study of the yttrium-hydrogen (Y-H) binary system were carried out to provide more comprehensive and quantitative insights into the key thermodynamic properties of this system. Y-H system in the full range of H/Y = 0–3.0 was investigated by accurate pressure composition isotherm (PCI) measurement to provide credible phase equilibria information and thermodynamic data. The phase boundaries obtained were in agreement with previous experimental data but with improved accuracy. With the guide of the crystal structures, all the solid phases were modelled using the three sublattice model. The Y-H phase diagram and thermodynamic parameters were calculated and assessed with the CALPHAD technique. The obtained results are in very good agreement with our experimental data and the published data reported in literature. The obtained thermodynamic database of Y-H system can be used to predict the hydrogenation behavior and decomposition temperatures of hydrides.

Ternary blends are currently used to improve the properties of Portland cement (PC). In this paper, thermodynamic modelling has been used to analyze the influence of the PC composition on the hydrates formed, in binary and ternary blends with blast furnace slag (BFS), and limestone filler (LF) or fly ash (FA) in order to complement experimental results. Thermodynamic modelling shows that contents of 40–50% of BFS can be optimal in ternary blends with low LF or FA content, and modelling also shows the significant effect of the composition of the PC used in the hydration process of the blends., Authors gratefully acknowledge the Spanish MICINN for the financial support given to this research in BIA2011-22760 project.

Titan's lower atmosphere has condensed phases in equilibrium with it. It is well known that there is a liquid phase in lakes and liquid condensates in the lower troposphere that are part of the liquid cycle in Titan's system. This work analyzes further the phase equilibria using CRYOCHEM equation of state by accounting for solid phases that can exist at the extremely cold conditions on Titan, as well as the possibility of a second liquid phase in the deep lakes, all within the ternary system nitrogen-methane-ethane. Titan's fluid exhibits rich variation of phases that allow us to show multiphase equilibria in full action. The multiphase equilibria covered in this work are two-phase (vapor-liquid, liquid-liquid, solid-liquid, solid-vapor, solid-solid), three-phase (vapor-liquid-liquid, vapor-liquid-solid, vapor-solid-solid, liquid-liquid-solid), and four-phase equilibria (solid-liquid-liquid-vapor); issues associated with the unphysical phases in the calculations are also discussed. The results of multiphase-equilibria analysis describe new understandings about Titan's surface, troposphere, and subsurface lake liquids, as described in the conclusions.

Co-based alloys are key materials for several high temperature applications where high corrosion and wear resistance are required. Main alloying elements, in addition to Co, are Cr, Ni, Ta, Mo, W, Ti, Al, etc. and C. In order to simulate these materials a new thermodynamic database has been implemented which includes the six most important alloying elements: Co, Cr, Ni,Ta, W and C. The liquid and 30 solid phases have been modelled by means of the Compound Energy Formalism (CEF) with particular attention to the consistency between thermodynamic and crystallographic sublattices. Interaction parameters for all the binary and ternary sub-systems are included. When possible they have been taken from the literature but, for several systems, partial or complete reassessment was needed, due to inconsistency of the phase models or incompatibility between assessments of different authors. As a result phase equilibria in selected commercial alloys are calculated.

To prove the feasibility of pyrometallurgical recovery of the rare earth elements, it is necessary to understand the thermodynamic properties of related rare earth oxides containing systems. Based on the experimental data as well as thermodynamic modelling of the silicate subsystems, a thermodynamic description of CaO-Gd2O3–SiO2 ternary system is constructed. The Gibbs energy of the liquid phase is modeled by the Modified Quasichemical Model. The solid phases are modeled by the polynomial expansions of the excess Gibbs energy. The present modelling ternary phase equilibria are in good agreement with the experimental data in the literature.

The isothermal section in the Mg–Cu rich region of Mg–Cu–Ca ternary system at 300 °C was investigated in the present work. Two ternary compounds named as P1 and Mg25-xCu75Cax were observed. The solid solubility limit of the compound Mg25-xCu75Cax was found to be 8.29 ≤ xCa ≤ 15.71 with a constant value of about 75 at. % Cu at 300 °C. A narrow solid homogeneity range of the compound P1 was found to be Mg19Cu40Ca41 to Mg21Cu42Ca37 (in at. %). The maximum solid solubility of Ca in the terminal compound MgCu2 (C15) was determined to be 10.20 at. % at 300 °C. The maximum ternary solid solubility of binary terminal compounds Mg2Ca, Mg2Cu, Cu5Ca and CuCa were determined to be less than 2 at. %. For the more, thermodynamic modeling of the Cu–Ca binary and Mg–Cu–Ca ternary systems have been carried out by calculation of phase diagram (CALPHAD) method. The liquid solution was described using the modified quasi-chemical model (MQM). The compound energy formalism (CEF) was used for the solid phases. A self-consistent thermodynamic database of the Mg–Cu–Ca ternary system have been constructed in the present work.

Studying liquid transition to other states of matter encounters certain challenges. The phase transition containing a liquid phase embodies energetic change that can be quantitatively correlated to the equilibrium conditions. The challenges can be more complex if the liquid is geometrically confined in a narrow space in which the energetic interaction between the confinement and confined liquid might become more pronounced. Therefore, it is of great essence to probe the enthalpic perspective of an equilibrium in which at least one liquid phase exists. However, the challenges can be used as opportunities to characterize both the confined liquid as well as the confinement material in terms of phase transition, intermolecular interaction, and pore size distribution. In this article, enthalpic studies of liquid phase equilibrium are carefully discussed. The majority of the discussions address the confined thermodynamic equilibrium that includes a liquid phase, especially the liquid phase transition under confinement to and from vapor and solid phases is elaborated in great details. In addition, enthalpic overviews of bulk equilibrium of liquids are briefed where challenges and opportunities to calorimetrically study these equilibrium states are remarked. An integrative and instructive approach is closely followed in order establish a network of information that can be used not only for comprehensively reviewing the existing state-of-the-art, but also for providing invaluable insight and constructive inputs for future studies to bridge the gaps in the field.

To meet the requirements of minimally invasive surgical treatments for osteoporotic vertebral compression fracture, various strategies have been proposed to enhance the properties of calcium phosphate cement (CPC). Here, a new strategy was developed by incorporating poly (γ-glutamic acid) (γ-PGA) and its strontium salt into the formulation of alpha tricalcium phosphate (α-TCP)-based CPC. Effects of γ-PGA on the injectability, cohesion, setting times, mechanical compressive strengths and cytocompatibility were systematically studied. Results showed that the injectability, cohesion and setting times were considerably improved by introducing γ-PGA into the CPC. Moreover, after setting for 7 days, the compressive strengths increased from 14.6 ± 1.4 MPa for pure CPC to 35.3 ± 1.7 MPa for CPC with 8.9 wt% γ-PGA and further to 61.2 ± 5.4 MPa for CPC with 8.9 wt% γ-PGA combined with its strontium salt. In vitro osteoblast proliferation tests showed that the group of CPC modified by γ-PGA and its strontium salt had better cytocompatibility than the pure CPC group. All results suggest that optimal properties were obtained for the cement with 8.9 wt% γ-PGA added to its solid phases and using strontium salt as the reactive liquid phase, making it as a promising candidate for application in kyphoplasty.

International audience; This paper presents the ongoing R&D research activities at IRSN related to the improvement of the properties of dust solid phases. It is illustrated by an ASTEC simulation of a wet-bypass scenario in the ITER facility. Special attention has been paid to the thermodynamic properties of beryllium hydride. The simulation of the selected accidental scenario highlights the potential formation of beryllium hydride dust as well as its tritiated form. © 2017 Elsevier B.V.

The study of temperature dependent thermodynamic parameters; Gibb’s free energy difference (ΔG), entropy difference (ΔS) and enthalpy difference (ΔH) between the undercooled liquid and the corresponding equilibrium solid phases has been proved to be extremely advantageous in the study of the thermodynamic behaviour of Metallic glass (MG) forming melts. In last two decades, Au- and Mg-based alloys were found to form glass phases. In present study, the three thermodynamic parameters viz., ΔG, ΔS and ΔH are calculated theoretically in the entire temperature range T m (melting temperature) to T g (glass transition temperature) for both Au- and Mg-based five samples of MGs; Au 77 Ge 13.6 Si 9.4 , Au 53.2 Pb 27.5 Sb 19.3 , Au 81.4 Si 18.6 , Mg 85.5 Cu 14.5 and Mg 81.6 Ga 18.4 on the basis of Taylor’s series expansion. A relative study is also made between the present result and the result obtained experimentally as well as on the basis of expressions projected by the earlier researchers. An attempt is also been made to narrate the reduced glass transition temperature with glass forming ability for all five MGs.

During long-term space missions, astronauts generate wet trash, including food containers with uneaten portions, moist hygiene wipes and wet paper towels. This waste produces two problems: the loss of water and the generation of odors and health hazards by microbial growth. These problems are solved by a closed-loop, forced-convection, heat-pump drying system which stops microbial activity by both pasteurization and desiccation, and recovers water in a gravity-independent porous media condensing heat exchanger. A transient, pseudo-homogeneous continuum model for the drying of wet ersatz trash was formulated for this system. The model is based on the conservation equations for energy and moisture applied to the air and solid phases and includes the unique trash characteristic of having both dry and wet solids. Experimentally determined heat and mass transfer coefficients, together with the moisture sorption equilibrium relationship for the wet material are used in the model. The resulting system of differential equations is solved by the finite-volume method as implemented by the commercial software COMSOL. Model simulations agreed well with experimental data under certain conditions. The validated model will be used in the optimization of the entire closed-loop system consisting of fan, air heater, dryer vessel, heat-pump condenser, and heat-recovery modules.

An algorithm to predict the composition of n -paraffin mixtures from calorimetry is proposed and applied for two thermodynamic approaches: one considering the formation of solid solutions and the other, known as multisolid phase model, assuming the presence of several independent pure solid phases. This methodology compares modeled calorimetric curves with DSC results through Particle Swarm Optimization. In order to better predict the mixtures compositions an appropriate proposal of the objective function was necessary. The present paper elucidates the process of defining an enhanced objective function aiming to improve the quality of predictions allowing the employment of calorimetric curves without information about sample’s mass. The deviations in calculated compositions are related to a difference of up to 1 K in the location of calorimetric peaks for solid solution approach.

Peritectic alloys form a variety of solidification morphologies of which peritectic coupled growth (PCG) is the most peculiar. Because the conditions that lead to PCG are still under discussion, in-situ investigations of the evolution from lateral bands to PCG were carried out by using binary organic TRIS-NPG model alloys at concentrations in the peritectic region. The experiments were done vertically with relatively large rectangle glass tubings. For a hyper-peritectic alloy at growth rates below the morphological stability limits of both solid phases, we found that first the properitectic phase grew while lateral bands of the peritectic phase formed between the glass walls and the properitectic phase. Then, the peritectic phase dominated the growth until lateral bands of the now properitectic phase occurred, again close to the glass walls. Now both phases grew side-by-side as two layers at different depths in the sample. However, the properitectic phase spread locally onto the peritectic/liquid interface, so that patches of peritectic phase surrounded by a properitectic matrix developed. This resulted in creating an unstable PCG mode with cycles of increasing and decreasing phase amounts, which from a side-on view resemble tulip- and onion-like structures respectively.

The article presents the method of production of foam concrete, as a geonoiseprotective material. Its ability to absorb acoustic energy due to porous structure, composition and thickness of foam films is taken into account. Besides that the energy-absorbing ability of the solid phases of the stone frame is taken into consideration. The possibility of using this foam concrete as a material for reducing noise from the railway transport movement is shown. Also, the method takes into account geoprotective properties of the material concerning the pollution from railway transport.

International audience; The solidification of binary eutectic alloys produces two-phase composite materials in which the microstructure, that is, the geometrical distribution of the two solid phases, results from complex pattern-formation processes at the moving solid-liquid interface. Since the volume fraction of the two solids depends on the local composition, solidification dynamics can be strongly influenced by thermosolutal convection in the liquid. In this contribution, we review our experimental and numerical work devoted to the understanding of eutectic solidification under purely diffusive conditions, which will soon be tested and extended during the microgravity experiment.; La solidification des alliages eutectiques binaires produit des matériaux composites biphasés, dont la microstructure, c'est-` a-dire l'arrangement géométrique des deux phases cristallines dans le solide, résulte d'un processus complexe d'auto-organisation à l'interface solide-liquide en cours de croissance. Puisque la fraction volumique des phases solides est une fonction de la composition locale, la dynamique de solidification peut être fortement influencée par des mouvements de convection thermo-solutale dans le liquide. Dans cet article, nous faisons le point sur nos travaux expérimentaux et numériques dédiés à la compréhension de la croissance eutectique en conditions de transport purement diffusif. Ces résultats seront bientôt testés et étendus dans une expérience en micropesanteur

The near-eutectic Al-12 wt.% Ce alloy has been alloyed with 0.4 wt.% Sc to improve its creep resistance. A bidirectional influence between Sc and Ce has been identified: (i) the Ce element suppresses the Sc partition between the liquid and solid phases during solidification, as implied by the reduction of Sc microsegregation in the as-cast ingot; (ii) the Sc atoms migrate towards the Al11Ce3 interface to form Al3Sc thin layer or particles upon aging. The former effect promotes the spatial uniformity of Al3Sc precipitate distribution in the Al matrix and the latter one introduces additional lattice misfit strain to the Al11Ce3/Al α phase boundary inhibiting matrix dislocations to climb over the Al11Ce3 lamellae. Both effects can improve the creep resistance of the aged Al-12Ce-0.4Sc alloy showing a high tensile stress threshold for dislocation creep of ∼ 60 MPa at 300 ∘ C.

Literature review, critical assessment and thermodynamic modeling of the liquid and solid phases in the As–S system are presented. A set of optimized model parameters was obtained to reproduce previously published experimental data. The literature data included enthalpies of formation, heat capacity, vapor pressure and phase equilibrium data. A significant discrepancy among different sets of literature data was revealed. The model for the liquid phase was developed within the framework of the Modified Quasichemical Model (MQM) in pair approximation. The resulting set of model parameters was merged and tested within a larger multicomponent thermodynamic database for pyrometallurgical copper, lead and recycling industrial operations.

Matrix acidizing is one of the most effective stimulation techniques to achieve industrial development of carbonate reservoirs. In this work, a two-scale continuum model is modified to consider mass conversion between liquid and solid phases. The results show that the mass conversion between liquid and solid phases is very important and nonnegligible. Compared to modified model, original model overestimates amount of acid required for core breakthrough. A series of numerical cases based on modified model are presented for sensitivity studies on acid injection conditions, core geometries, acid, and rock properties. The modified model can well capture optimum acid injection velocity and typical dissolution patterns observed in experimental studies. Pore volume to breakthrough (PVBT) is very sensitive to acid injection concentration and acid surface reaction rate. Increasing injected acid concentration substantially reduces the amount of solute required but acid injection mass does not change significantly. Strong acid can effectively reduce least pore volume to breakthrough (PVBT) but meanwhile optimum acid injection velocity obviously increases. The simulation results are compared with available experimental and numerical data and found to attain a consistent match.

In indoor environments, humans ingest chemicals present as surface residues and bound to settled particles (dust), through mouthing hands (hand-to-mouth transfer) and objects (object-to-mouth transfer). Here, we introduce a novel modeling approach in support of systematic investigation into the mouthing-mediated ingestion of chemicals present in indoor environments. This model explicitly considers the indoor dynamics of dust and chemicals, building on mechanistic links with physicochemical properties of chemicals, features of the indoor environment, and human activity patterns. The evaluation of this model demonstrates that it satisfactorily reproduces chemical hand loadings and exposure data reported in the literature. We then use the evaluated model to investigate the response of mouthing-mediated ingestion to chemical partitioning between the gas phase and solid phases, expressed as the octanol–air partition coefficient (KOA). Assuming a unit emission rate to the indoor environment, we find that low-volatility chemicals (with a KOA greater than 109) are more efficiently enriched in hand skin, resulting in higher mouthing-mediated ingestion than other compounds. For individuals living in a room with a typical level of dustiness, more than half of the chemical mass found in their hands comes from dust transfer, whereas more than half of the chemical mass ingested is the fraction present as residues on hands. We also use the new model to explore how the mouthing-mediated ingestion of chemicals is dependent on factors describing the indoor environment and human behavior. The model predicts that less frequent cleaning leads to higher accumulation of dust on indoor surfaces, thereby transferring more chemicals to hands and mouth in each contact. Introducing more dust into the room, but maintaining the same cleanup frequency, increases the dustiness of indoor surfaces, which promotes the transfer of relatively volatile chemicals (with a KOA lower than 109) to hands and mouth but decreases the transfer of chemicals with low volatility. More frequent hand contact with indoor surfaces increases both the hand loading and mouthing-mediated ingestion of chemicals, but the increases are more remarkable for adults than children because the higher surface contact frequency of children “saturates” hand loadings. An increase in handwashing frequency lowers the hand loading and mouthing-mediated ingestion of chemicals and this mitigating process is more prominent for relatively volatile chemicals. The new evaluated modeling approach can facilitate the prediction of mouthing-mediated ingestion for various age groups and the model predictions can be used to aid future fate and (bio)monitoring studies focusing on indoor contamination.

Liquid crystal physical gels were (thermally) prepared with cholesteryl stearate as a gelator in nematic liquid crystal, 4-cyano-4′-pentylbiphenyl. The electro-optical performance of liquid crystal physical gels is almost entirely dependent on the gels' inherent morphology. This study involved an empirical investigation of the relationships among all of the gelation temperature, morphology, and electro-optical properties. Besides continuous cooling at room temperature, isothermal cooling was also performed at both 18 and 0 °C, corresponding to near-solid and solid phases of 4-cyano-4′-pentylbiphenyl respectively. Nevertheless, the liquid crystal physical gel was also isothermally rapidly cooled using liquid nitrogen. Polarizing optical microscopy showed that the gel structure became thinner when isothermal cooling was carried out. These thinner gel aggregates then interconnected to form larger liquid crystal domains. Moreover, it was also revealed that the gel networks were randomized. Electron spin resonance results showed that the liquid crystal director orientation was severely randomized in the presence of gel networks. Conversely, isothermal cooling using liquid nitrogen generated a higher liquid crystal director orientation order. The 6.0 wt% cholesteryl stearate/4-cyano-4′-pentylbiphenyl physical gel that was isothermally cooled using liquid nitrogen showed the lowest response time in a twisted nematic mode optical cell.

Recently, a novel antimonite layered Na-ion cathode material, Na 3 Ni 2 SbO 6 , exhibited promising electrochemical performance. However, there has been no research whether this framework allows structural variations that could further enhance its electrochemical performance. Here we have tested Na 3 Ni 2−x Mg x SbO 6 (x=0, 0.25, and 0.5) solid phases. Having slightly decreased specific capacities, Mg-doped Na 3 Ni 2 SbO 6 shows enhanced rate performance due to better structural integrity and slightly lowered unit cell volume changes upon desodiation.

The article analyses the influence of technological factors on variations in the stress and strain state during the production of prestressed concrete sleepers. The paper focuses on technological damage to the anchorage zone and its influence on concrete and the pretensioned reinforcement of the last prestressed concrete sleepers located by abutments. The article presents the calculation principles of stresses caused by thermal and humidity deformations, compares theoretical and experimental results and specifies the nature of damages. The paper deals with concrete structure and an interface between reinforcement and concrete of new and three years old prestressed concrete sleepers, explores the results of laboratory tests on deteriorating the ends of new prestressed concrete sleepers under freezing and thawing cycles, looks at changes in concrete structure and the interface between reinforcement and concrete at the ends and in the middle of prestressed concrete sleepers applying a scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS). Secondary ettringite formation (DEF) in concrete micro-cracks and at the interface between reinforcement and concrete and elemental composition of the formed crystals have been determined. Significant difference in concrete structure and new solid phases at the ends of used and new sleepers has been defined. Concrete structure in the middle of the three years old railway sleeper has remained almost unchanged. The obtained results show that technological factors are affecting the deterioration nature of the ends of prestressed concrete sleepers., Authors are grateful to Civil Engineering Scientific Research Centre of Vilnius Gediminas Technical University and Laboratory of Building Products Technology in the Scientific Institute of Thermal Insulation, Vilnius Gediminas Technical University for equipment and infrastructure, which were employed for investigation

Coefficient of thermal expansion (CTE) test procedures use saturated concrete samples to (ostensibly) avoid the effect of moisture content. Concrete is a porous material, and internal water pressure develops in saturated concrete when subjected to temperature change due to the difference in CTE between liquid and solid phases. The measured CTE is affected by the internal water pressure development in saturated concrete samples. This paper represents an analytical model that was developed based on the poromechanical phenomenon of concrete to determine the time dependent internal water pressure and axial strain development. Material properties including, CTE, moduli of liquid and solid phase of concrete, as well as porosity and permeability of concrete samples have influence on the internal water pressure development. The predicted axial strain from the proposed numerical model for saturated concrete samples subjected to temperature changes were consistent with the experimental results. Predicted internal water pressure of the hardened concrete cylinder was as high as 700 psi (4.8 MPa), which is sufficiently high to potentially induce microcracking.