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This investigation was aimed at finding the optimum replacement level of waste brick powder (WBP) as a partial replacement of cement. For this purpose, three groups of tests are made: fresh, mechanical, and permeation properties. Eight mixes with different percentages of replacing ratios are as follows: 10, 15, 20, 25, 30, 35, 40, and 50%. In addition to the reference mix without powder replacements, the experimental programs include three groups of tests: fresh properties (flow test and fresh density), mechanical properties (dry density, compressive strength, and flexural strength), and transport properties (water absorption ratio, rate of water absorption, i.e., sorptivity, and permeable void ratio). Also, an ultrasonic velocity impulse test was made. The flowability and density of fresh mixes are decreased linearly as the amount of WBP increases for the constant water/binder ratio. However, the density of the in-hardened state was found to be slightly higher than the reference mix for mixes with a brick powder content of up to 20%. Results indicate that strengths for mixes containing WBP are higher than those for the control mix. The highest strength was examined in the mix with 15% WBP for both compressive and tensile strengths of specimens. Generally, the brick powder reduced the ability of mortar to transfer liquid, as was clear from the results of the permeability test results. Empirical relations were proposed according to experimental results.

The distribution of fiber diameters plays a crucial role in the transport and sound absorbing properties of a three-dimensional random fibrous (3D-RF) medium. Conventionally, volume-weighted averaging of fiber diameters has been utilized as an appropriate microstructural descriptor to predict the static viscous permeability of 3D-RF media. However, the long wavelength acoustical properties of a 3D-RF medium are also sensitive to the smallest fibers, this is particularly true in the high-frequency regime. In our recent research, we demonstrated that an inverse volume-weighted averaging of fiber diameters can effectively serve as a complementary microstructural descriptor to capture the high-frequency behavior of polydisperse fibrous media. In the present work, we reexamine the identification of two representative volume elements (RVEs) which relies on the reconstruction of 3D-RF microstructures having volume-weighted and inverse-volume weighted averaged fiber diameters, respectively in the low-frequency and high frequency regimes. We investigate the implication of such a weighting procedure on the transport and sound absorbing properties of polydisperse fibrous media, highlighting their potential advantages. Furthermore, we discuss the challenges associated with this research field. Finally, we provide a brief perspective of the future directions and opportunities for advancing this area of study.

Due to its large hole mobility, organic rubrene (C42H28) has attracted research questions regarding its applications in electronic devices. In this work, extensive first-principles calculations are performed to predict some temperature- and doping-dependent properties of organic semiconductor rubrene. We use density functional theory (DFT) to investigate the electronic structure, elastic and transport properties of the orthorhombic phase of the rubrene compound. The calculated band structure shows that the orthorhombic phase has a direct bandgap of 1.26 eV. From the Vickers hardness (1.080 GPa), our calculations show that orthorhombic rubrene is not a super hard material and can find useful application as a flexible semiconductor. The calculated transport inverse effective mass and electronic fitness function show that the orthorhombic rubrene crystal structure is a p-type thermoelectric material at high temperatures.

Influence mechanism of various ion chelators on the mechanical, transport, and microstructure properties of cement-based materials was explored. The ion chelators included pentasodium diethylenetriamine pentaacetate, tetrasodium ethylenediaminetetraacetate, sodium hexametaphosphate and tetrasodium glutamate diacetate, with a dosage of 1 % of the cement mass. The effect of ion chelators on the mechanical, transport, and pore structure properties was evaluated by compressive, sorptivity, and mercury intrusion porosimetry (MIP) tests. The composition and microstructure of hydration products were studied by scanning electron microscope (SEM) and X-ray diffractometer (XRD). Test results indicated that four ion chelators reduced the mechanical and transport properties, and increased the porosity of specimens at 3 d and 7 d. And four ion chelators improved the mechanical and transport properties, and reduced porosity at 28 d and 56 d. The fundamental reason for the differences in the basic properties of cement-based materials caused by the types of ion chelators is that different ion chelators possess various calcium chelating capacities and stability of calcium complexes, which leads to different impact on the complexation substitution reaction process. Moreover, compared to the stability of calcium complexes, the influence of calcium chelating ability on the basic properties of specimens is more significant in the early curing ages.

The gas diffusion layer (GDL), as the bridge to reactants and electrons in PEMFC, is a carbon-based porous component and would be deformed under compression to induce changes in the distributions of reactants and the corresponding performances of PEMFC; therefore, unmasking the impacts of assembly pressure on the distribution of the reactants in GDL is significant to improve the performance of PEMFC. In the present article, the structural response of GDL to assembly pressure was first studied; the variations in transport properties of GDL and the reactant distributions induced by assembly pressure were then discussed; the impacts on the dynamic performances of PEMFC were finally investigated. From the results, assembly pressure was found to have different effects on the regions of GDL under the rib and channel, significant gaps in GDL porosity and/or GDL permeability existed near the rib/channel transition region to worsen the inhomogeneity of reactants. Suffering assembly pressure, the distribution of current density became uneven, and the current density near the rib-channel border seriously rose to the aggravated risk of MEA thermal damage. Furthermore, the power density at specific efficiencies was raised under certain assembly pressures, which meant suitable assembly pressure(s) existed for better output performances of PEMFC.

The thermodynamic and transport properties of high-temperature chloride molten salt systems are of great significance for spent fuel reprocessing in the field of nuclear energy engineering. Here, by using machine learning based deep potential (DP) method, we train a high-precision force field model for the LiCl-KCl-LiF system. During force field training, adding new dataset through multiple iterations improves the accuracy of the force field model and its applicability to more configurations. The comparison of density functional theory (DFT) and DP results for the test dataset indicates that our trained DP model has the same accuracy as DFT. Then, we comprehensively investigate the local structure, thermophysical properties, and transport properties of the LiCl-KCl and LiCl-KCl-LiF molten salt systems using the trained DP model. The effects of temperature and LiF concentration on the above properties are analyzed. This work provides guidance for the training of machine learning force fields in molten salt systems and the study of basic physical properties of high-temperature chloride molten salt systems.

This study investigates the links between the non-steady-state chloride migration coefficient, the bulk electrical conductivity and the formation factor of blended cement paste specimens. 18 different binders were tested: two Portland cements (low- and high-alkali) in combination with limestone filler, fly ash, calcined clay, two biomass ashes, sewage sludge ash and crushed brick, as well as two Portland composite cements. In addition, the latter and the low-alkali Portland cement were tested in concrete as well for comparison.

Hybrid carbon nanotube (CNT) sheets were fabricated by mixing CNTs with silver nanowires (AgNWs) and MXene to study their electromagnetic-interference (EMI)-shielding properties. CNT/AgNW and CNT/MXene hybrid sheets were produced by ultrasonic homogenization and vacuum filtration, resulting in free-standing CNT sheets. Three different weight ratios of AgNW and MXene were added to the CNT dispersions to produce hybrid CNT sheets. Microstructure characterization was performed using scanning electron microscopy, and the Wiedemann–Franz law was used to characterize transport properties. The resulting hybrid sheets exhibited improved electrical conductivity, thermal conductivity, and EMI-shielding effectiveness compared to pristine CNT sheets. X-band EMI-shielding effectiveness improved by over 200%, while electrical conductivity improved by more than 1500% in the hybrid sheets due to a higher charge-carrier density and synergistic effects between nanomaterials. The addition of AgNW to CNT sheets resulted in a large improvement in electrical conductivity and EMI shielding; however, this may also result in increased weight and sample thickness. Similarly, the addition of MXene to CNT sheets may result in an increase in weight due to the presence of the denser MXene flakes.

The main objective of this work was to analyze the transport by diffusion of salts containing some metal ions (that is, CoCl2, CrCl3, HgCl2, and PbCl2), at 25.0 °C, in two different aqueous solutions with varying pH levels, namely, sodium chloride and hydrochloric chloride, by using Nernst–Hartley model equations. To analyze the applicability of this model, experimental data for two aqueous systems (CoCl2 + NaCl) and (CoCl2 + HCl), were obtained by using the Taylor technique and compared with the predicted values. The Nernst–Hartley model equations were used in this study to estimate the mutual diffusion coefficients of the eight ternary systems, which included (CoCl2 + NaCl), (HgCl2 + NaCl), (PbCl2 + NaCl), (CrCl3 + NaCl), and (CoCl2 + HCl), (HgCl2 + HCl), (PbCl2 + HCl), and (CrCl3 + HCl). By using the limiting equations of Nernst–Hartley coefficients, we were able to understand the composition dependence of the mutual diffusion coefficients of these mixed electrolyte solutions and the electrostatic mechanism for the strongly coupled diffusion of these components.

Electrical and thermal transport measurements on quenched NaCl-type Ag1/3Pb1/3Sb1/3Se reveal an n-type semiconductor with a Seebeck coefficient up to −140 μVK−1 and a thermal conductivity as low as 0.52 WmK−1. Short-range order is indicated by disorder diffuse scattering in electron diffraction patterns. In contrast, 4L-Ag0.61Pb1.79Sb2.61Se6 (space group Cmcm with a = 4.2129(1) Å, b = 13.852(1) Å, and c = 20.866(1) Å, Z = 4) features the first lillianite-type structure in the system Ag/Pb/Sb/Se. It consists of slab-like NaCl-type building blocks that are interconnected via trigonal [PbSe6] prisms. As such structures typically do not form with Te as an anion, the first “sulfosalt-like” compound, Ag0.38Pb0.25Sb2.38Te4, in the system Ag/Pb/Sb/Te forms a layered tetradymite-like structure (space group R3-m with a = 4.2887(1) Å, c = 41.544(1) Å, Z = 3). Its slabs, which are separated by van der Waals gaps, are built up from three layers of distorted [MTe6] octahedra. Crystals of Ag0.38Pb0.25Sb2.38Te4 were grown by chemical transport.

In the current work we studied the structural, elastics, electrical, optical, thermoelectric, as well as spectroscopic limited maximum efficiency (SLME) of oxide based Ba2AsBO6 (BNb, Ta) materials. All the calculations were performed using first-principles calculation by employing the WIEN2k code. We checked the stability in diverse forms such as optimization, phonon dispersion, mechanical, formation energy, cohesive energy, and thermal stability is computed. The semiconducting nature of these Ba2AsBO6 (BNb, Ta) systems is revealed by calculating the direct band gap values are 1.97 eV and 1.49 eV respectively. Additionally, we determined the optical properties which analyze the utmost absorption and transition of carriers versus photon energy (eV). Moreover, Ba2AsNbO6 has an estimated SLME of 32 %, making it an encouraging alternative for single-junction solar cells. Lastly, we studied the transport properties against temperature, the chemical potential for p-type and n-type charge carriers at various temperatures. At 300 K, the zT values are found to be 0.757 and 0.751 for Ba2AsBO6 (BNb, Ta) compounds respectively. Both materials were examined as having strong absorption patterns and an excellent figure of merit (ZT), indicating that materials are appropriate for daily life applications.

Two-dimensional (2D) semiconductors have attracted much attention regarding their use in flexible electronic and optoelectronic devices, but the inherent poor electron mobility in conventional 2D materials severely restricts their applications. Using first-principles calculations in conjunction with Boltzmann transport theory, we systematically investigated the Si-doped 2D β-Ga2O3 structure mediated by biaxial strain, where the structural stabilities were determined by formation energy, phonon spectrum, and ab initio molecular dynamic simulation. Initially, the band gap values of Si-doped 2D β-Ga2O3 increased slightly, followed by a rapid decrease from 2.46 eV to 1.38 eV accompanied by strain modulations from −8% compressive to +8% tensile, which can be ascribed to the bigger energy elevation of the σ* anti-bonding in the conduction band minimum than that of the π bonding in the valence band maximum. Additionally, band structure calculations resolved a direct-to-indirect transition under the tensile strains. Furthermore, a significantly high electron mobility up to 4911.18 cm2 V−1 s−1 was discovered in Si-doped 2D β-Ga2O3 as the biaxial tensile strain approached 8%, which originated mainly from the decreased quantum confinement effect on the surface. The electrical conductivity was elevated with the increase in tensile strain and the enhancement of temperature from 300 K to 800 K. Our studies demonstrate the tunable electron mobilities and band structures of Si-doped 2D β-Ga2O3 using biaxial strain and shed light on its great potential in nanoscale electronics.

The mechanical properties, electronic structure, electric transport and optoelectronic properties of a recently predicted wide bandgap semiconductor β-HfNCl monolayer are systematically studied by means of first-principles calculations. β-HfNCl monolayer is isotropic in mechanical properties, whose calculated Young’s modulus, shear modulus, and layer modulus of β-HfNCl monolayer are 128.9–129.2, 44.28, and 119.46 N m−1, respectively. An appropriate tensile strain (i.e., beyond 3 %) can induce a transition from indirect bandgap to direct bandgap. In addition, we construct several conceptual nanodevice structures based on β-HfNCl monolayer, such as pn-junction diodes, pin-junction field-effect transistors (FETs) and phototransistors. The electronic transport results reveal that the pn-junction diodes have obvious rectification effect and strong electric anisotropy. Their rectification ratios and electric anisotropy ratio (η) can reach up to 106 and 3.69, respectively. The FETs have an obvious field-effect behavior with a slightly lower rectification ratio (105). Moreover, we investigate the photoelectric response of the phototransistors of β-HfNCl monolayer under the illumination of light. They have a strong response to the light whose energy is larger than the violet light, indicating that the β-HfNCl monolayer can be a platform to detect the ultraviolet light. These findings provide crucial insights into the potential applications of β-HfNCl monolayer in electronic and optoelectronic devices.

Low temperature belite cements are produced using techniques that stabilize the more reactive high temperature polymorphs of dicalcium silicate (C2S) to improve early strength, but the effect of curing conditions on them is not well studied. The focus of this work is to assess the improvement of their early strength in different curing conditions. During the synthesis of the cements at 1000 ºC, the more reactive polymorphs, -C2S and ?-C2S, were stabilized using gypsum and hydrothermal treatment with potassium hydroxide. The phase composition of the synthesized cements was analysed using X-ray powder diffraction. The morphology and elemental composition of the C2S crystals and hydrated pastes was determined using a scanning electron microscope equipped with an energy-dispersive X-ray system. Mortar samples were cured in different conditions that include hot air and hot water curing at 60 ºC and 90 ºC. The 28-day strength development, capillary water porosity, water absorption, and ultrasonic pulse velocity were tested. The formation of hydration products and strength was dependent on the type of C2S polymorph. Curing at elevated temperatures improved the transport properties of mortars. Samples cured at 90 ºC in hot air obtained the highest early strength. The presence of -C2S and elevated curing temperatures significantly improve the early strength of the mortar samples. ABSTRAK: Simen belite suhu rendah dihasilkan melalui teknik menstabilkan reaktif polimof dikalsium silikat (C2S) bersuhu tinggi bagi meningkatkan kekuatan awal, tetapi kesan keadaan pengawetan ke atasnya tidak dikaji dengan baik. Fokus kerja ini adalah bagi menilai peningkatan kekuatan awal pada keadaan pengawetan berbeza. Sintesis simen pada suhu 1000 ºC, iaitu pada polimof lebih reaktif, -C2S dan ?-C2S, telah distabilkan menggunakan rawatan gipsum dan hidroterma dengan kalium hidroksida. Fasa komposisi simen tersintesis dianalisa menggunakan pembelauan serbuk sinar-X. Komposisi morfologi dan unsur kristal C2S dan pes terhidrat ditentukan menggunakan pengimbas mikroskop elektron yang dilengkapi sistem sinar-X penyebar tenaga. Sampel mortar telah diawetkan dalam keadaan berbeza termasuk pengawetan udara panas dan air panas pada suhu 60 ºC dan 90 ºC. Perkembangan kekuatan keliangan kapilari air, penyerapan air, dan halaju nadi ultrasonik telah diuji pada hari ke 28. Pembentukan produk penghidratan dan kekuatan adalah bergantung kepada jenis polimof C2S. Pengawetan pada suhu tinggi meningkatkan sifat pengangkutan mortar. Sampel yang diawet pada 90 ºC dalam udara panas memperoleh kekuatan awal tertinggi. Kehadiran -C2S dan suhu pengawetan tinggi dengan ketara meningkatkan kekuatan awal sampel mortar.

ABSTRACTTopological insulators and semimetals are an interesting class of materials for new electronic and optical applications owing to their characteristic electromagnetic responses originating from the spin-orbit coupled band structures. However, topological electronic structures are rare in oxide materials despite their chemical stability being preferable for applications. In this study, given the theoretical prediction of Dirac bands in CaPd3O4, we investigate the fabrication and transport properties of SrPd3O4 and CaPd3O4 thin films as candidates of oxide Dirac semimetals. We have found that these materials are epitaxially grown on MgO (100) substrate under limited growth conditions by pulsed laser deposition. The transport properties show a weak temperature dependence, suggestive of narrow-gap properties, although unintentionally doped holes hinder us from revealing the presence of the Dirac band. Our study establishes the basic thermodynamics of thin-film fabrication of these materials and will lead to interesting properties characteristic of topological band structure by modulating the electronic structure by, for example, chemical substitutions or pressure.

This research aims to study the effect of adding nanosilica (NS) on the properties of sustainable high-strength concrete (SHSC). The SHSC was produced using recycled aggregates from concrete debris as a 100% alternative to coarse aggregate, and industrial waste was used as supplementary cementitious materials at 50% and 75% of Ordinary Portland cement (OPC) weight. A total of 25 mixes, including control mix (The first mix was made as the reference by using only cement without replacement materals), binary mixes (OPC and fly ash (FA)), ternary mixes (OPC, FA and ground-granulated blast-furnace slag (GGBS)) and quaternary mixes (OPC, FA, GBFS and silica fume (SF)) were developed. The dosage of NS was 0%, 1%, 3% and 5% by binder ratio. The fresh properties of SHSC were evaluated by slump test, and the mechanical properties were assessed by testing the compressive strength, splitting tensile strength, flexural strength and modulus of elasticity. The transport properties were evaluated by water permeability, water sorptivity and chloride permeability tests. Results showed that compared with the reference mixture, the SHSC containing 75% of the quaternary blends with 3% NS achieved enhanced mechanical properties at 28 and 91 days, indicating that this mixture can achieve the highest sustainability performance. The SHSC mixture containing 3% NS and 50% quaternary mixtures achieved the highest performance of 80.7, 6.46 and 10.09 MPa for compressive strength, split tensile strength and flexural strength, respectively, at 28 days. This SHSC mixture also achieved water permeability; chloride permeability was 2.54 × 10−11 (cm/sec) and 1370 coulombs at 28 days.

Agricultural countries suffer from growth problems of agricultural waste ash (AWA). This research paper studies the use of AWA as a partial substitute for cement to produce ultra-high-strength concrete (UHSC). This paper also investigates the effect of using sugarcane bagasse ash (SBA) and corn stalk ash (CSA) on the properties of UHSC. Residues from the combustion process of agricultural wastes are utilized as a pozzolanic material inserted as a partial substitute for cement for UHSC production. The replacement rates of cement by the SBA were 10%, 20%, and 30% of the mass, whilst those of cement by the CSA were 2%, 4%, 6%, and 8% of the mass. The effects of SBA and CSA on workability, compressive strength, splitting tensile strength, flexural strength, and modulus of elasticity on UHSC properties were investigated. In addition, the effects of SBA and CSA on resistance to chloride ion penetration and water sorptivity and permeability in UHSC were investigated. The investigations showed impressive results. That is, producing UHSC with respective compressive and flexural strengths of more than 205 and 27 MPa is possible when 24% of cement mass replacement by AWA (SBA 20% + CSA 4%) is conducted at the test age of 28 days. The lowest permeability is achieved with 38% of cement mass replacement by AWA (SBA 30% + CSA 8%) of 140 coulombs and 0.95 (cm/sec) for chloride and water permeability, respectively.

This scientific study employs the Taylor dispersion technique for diffusion measurements to investigate the interaction between sulfamerazine (NaSMR) and macromolecular cyclodextrins (β-CD and HP-β-CD). The results reveal that the presence of β-CD influences the diffusion of the solution component, NaSMR, indicating a counterflow of this drug due to solute interaction. However, diffusion data indicate no inclusion of NaSMR within the sterically hindered HP-β-CD cavity. Additionally, toxicity tests were conducted, including pollen germination (Actinidia deliciosa) and growth curve assays in BY-2 cells. The pollen germination tests demonstrate a reduction in sulfamerazine toxicity, suggesting potential applications for this antimicrobial agent with diminished adverse effects. This comprehensive investigation contributes to a deeper understanding of sulfamerazine–cyclodextrin interactions and their implications for pharmaceutical and biological systems.

In this work, we propose a comprehensive experimental study of the diffusion of nickel ions in combination with different cyclodextrins as carrier molecules for enhanced solubility and facilitated transport. For this, ternary mutual diffusion coefficients measured by Taylor dispersion method are reported for aqueous solutions containing nickel salts and different cyclodextrins (that is, α-CD, β-CD, and γ-CD) at 298.15 K. A combination of Taylor dispersion and other methods, such as UV-vis spectroscopy, will be used to obtain complementary information on these systems. The determination of the physicochemical properties of these salts with CDs in aqueous solution provides information that allows us to understand solute–solvent interactions, and gives a significant contribution to understanding the mechanisms underlying diffusional transport in aqueous solutions, and, consequently, to mitigating the potential toxicity associated with these metal ions. For example, using mutual diffusion data, it is possible to estimate the number of moles of each ion transported per mole of the cyclodextrin driven by its own concentration gradient.

As a highly regarded superconducting material with a concise layered structure, MgB2 has attracted significant scientific attention and holds vast potential for applications. However, its limited current-carrying capacity under high magnetic fields has greatly hindered its practical use. To address this issue, we have enhanced the superconducting performance of MgB2 by incorporating inhomogeneous phase nanostructures of p-n junctions with electroluminescent properties. Through temperature-dependent measurements of magnetization, electronic specific heat, and Hall coefficient under various magnetic fields, we have confirmed the crucial role of inhomogeneous phase electroluminescent nanostructures in improving the properties of MgB2. Experimental results demonstrate that the introduction of electroluminescent inhomogeneous phases effectively enhances the superconducting performance of MgB2. Moreover, by controlling the size of the electroluminescent inhomogeneous phases and optimizing grain connectivity, density, and microstructural uniformity, we can further improve the critical temperature (TC) and flux-pinning capability of MgB2 superconducting materials. Comprehensive studies on the physical properties of MgB2 superconducting structures added with p-n junction electroluminescent inhomogeneous phases also confirm the general effectiveness of electroluminescent inhomogeneous phases in enhancing the performance of superconducting materials.

Ground Granulated Blast-Furnace Slag (GGBS) and silica fume (SF) are frequently utilized in gel materials to produce environmentally sustainable concrete. The blend of the two components contributes to an enhancement in the pore structure, which, in turn, increases the mechanical strength of the material and the compactness of the pore structure and decreases the permeability, thereby improving the durability of the concrete. In this study, the pore structures of GGBS and SF blends are assessed using Nuclear Magnetic Resonance (NMR) and Mercury Intrusion Porosimetry (MIP) tests. These methodologies provide a comprehensive evaluation of the effect of GGBS and SF on the pore structure of cementitious materials. Results showed that the addition of SF and GGBS reduces the amount of micro-capillary pores (10 < d < 100 nm) and the total pore volume. The results indicate that the transport properties are related to the pore structure. The incorporation of SF reduced the permeability of the concrete by an order of magnitude. The pore distribution and pore composition had a significant effect on the gas permeability. The difference in porosity obtained using the MIP and NMR tests was large due to differences in testing techniques.

The goal of this article is to introduce the quantum Hall effect (QHE) from its classical roots to the quantum integer and fractional versions. This is a robust phenomenon with topological nature. Regarding the fractional quantum Hall effect, its phenomenology and the possibility of vortices with fractional charges are also discussed. The lattice structure of graphene, one of the possible planar matter samples in which quantum Hall effects can occur, is also analyzed. The calculation of the Landau levels occurring in this specific substrate is carefully performed. For completeness, a field description for a whole class of these systems, the ones related to the fractional quantum Hall effect, is also reviewed.

Half-Heusler (HH) thermoelectric (TE) composites have been extensively inspected due to their excellent TE properties in the medium- to high-temperature range. First-principle calculations make it easier to discover or improve more HH compounds. This article presents an ab initio theoretical evaluation of TE properties of Half-Heusler alloy, when doped with Nickel (Ni), using FP-LAPW and the semi classic Boltzmann theory. Thermoelectric parameters were calculated using BoltzTraP code, like Seebeck coefficient ( ), electrical conductivity to relaxation time ratio ( ), electronic thermal conductivity to relaxation time ratio ( ), thermoelectric power factor to relaxation time ratio ( ), and the dimensionless figure-of-merit ( ) in a temperature range of . Calculated Seebeck coefficient reveals that the studied alloys show a tendency to conduct as p-type with balanced TE performance between both charge carriers (holes and electrons). A high electronic thermal conductivity value is found, which predicts a potential use in heat sink applications for the investigated alloys. Obtained results, such as a high thermoelectric power factor and , postulate that alloys could have potential thermoelectric applications.

Polyimides are a polymer class that has been extensively investigated as a membrane material for gas separation owing to its interesting permselective properties in a wide range of operation temperatures and pressures. In order to improve their properties, the addition of different filler types is currently studied. p-tert-Butylcalix[n]arene macrocycles (PTBCs) with different cavity sizes (PTBC4, PTBC6, PTBC8) were used as fillers in a commercial thermoplastic polyimide, with a concentration in the range 1–9 wt%, to develop nanocomposite membranes for gas separation. The selected macrocycles are attractive organic compounds owing to their porous structure and affinity with organic polymers. The nanocomposite membranes were prepared in the form of films in which the polymeric matrix is a continuous phase incorporating the dispersed additives. The preparation was carried out according to a pre-mixing approach in a mutual solvent, and the solution casting was followed by a controlled solvent evaporation. The films were characterized by investigating their miscibility, morphology, thermal and spectral properties. The gas transport through these films was examined as a function of the temperature and also time. The results evidenced that the incorporation of the chosen nanoporous fillers can be exploited to enhance molecular transport, offering additional pathways and promoting rearrangements of the polymeric chains.

The influence of various energetic particles and electron injection on the transport of minority carriers and non-equilibrium carrier recombination in Ga2O3 is summarized in this review. In Ga2O3 semiconductors, if robust p-type material and bipolar structures become available, the diffusion lengths of minority carriers will be of critical significance. The diffusion length of minority carriers dictates the functionality of electronic devices such as diodes, transistors, and detectors. One of the problems in ultrawide-bandgap materials technology is the short carrier diffusion length caused by the scattering on extended defects. Electron injection in n- and p-type gallium oxide results in a significant increase in the diffusion length, even after its deterioration, due to exposure to alpha and proton irradiation. Furthermore, post electron injection, the diffusion length of an irradiated material exceeds that of Ga2O3 prior to irradiation and injection. The root cause of the electron injection-induced effect is attributed to the increase in the minority carrier lifetime in the material due to the trapping of non-equilibrium electrons on native point defects. It is therefore concluded that electron injection is capable of “healing” the adverse impact of radiation in Ga2O3 and can be used for the control of minority carrier transport and, therefore, device performance.

Four decades have elapsed since the first quasiperiodic crystal was discovered in the Al–Mn alloy system, and much progress has been made during this time on the science of quasicrystals (QCs). Notwithstanding this, a significant number of open questions still remain regarding both fundamental and technological aspects. For instance: What are QCs good for? How can we improve the current provisional QC definition? What is the role of the underlying quasiperiodic order and the characteristic inflation symmetry of these compounds in the emergence of their unusual physicochemical properties? What is the nature of chemical bonding in QCs formed in different sorts of materials such as alloys, oxides, or organic polymers? Herein these and other closely related issues are discussed from an interdisciplinary perspective as well as prospective future work in the field in the years to come.

The current study aims to investigate influence of w/cm ratio, cementitious materials content and supplementary cementitious materials on the transport properties of concrete and chloride-induced corrosion rate of reinforcement. To do this, several mixes are designed with and without silica fume and natural zeolite as supplementary cementitious materials, w/cm of 0.4 and 0.5, and cementitious materials contents of 325 and 400 kg/m3. These mixes are subjected to evaluation of compressive strength, transport properties (i.e. absorption, water penetration depth and rapid chloride penetration test), and corrosion rate measurement through Potentiodynamic test and electrochemical measurements. The results of this study reveal that there is not strong correlation between corrosion rate of reinforcement and the measured strength and transport properties. The corrosion rate of reinforcement significantly decreased through reduction of water-to-cementitious materials ratio and use of supplementary cementitious materials; of which w/cm showed a more considerable influence. Increase in cement content, however, increased the transportation of water and chloride into the concrete and thus increased the corrosion rate of reinforcement.

Prior to intrusion, magma migrates through the crustal plumbing system that likely contains layers or columns of crystal mush. To better understand the behavior of the crustal magmatic system during magmatic unrest, it is important to examine the process of melt migration within the crystal mush and the associated evolution in pressure and temperature. In this study I use an analytical model to explore the characteristics of transport of melt, pressure, and heat through an idealized crystal mush layer/column under uniaxial strain condition. The model invokes a thermo-poro-viscoelastic rheology and uses a frequency-domain method to explore two scenarios of magmatic unrest: harmonic perturbation of fluid pressure, and step-rise in fluid pressure at a source location. Several factors influence the transport of melt, pressure and heat, including the thermal-mechanical coupling arising from the mush rheology, the advection of heat by melt flows, the competition between thermal diffusivity and poroelastic diffusivity, and the viscoelastic relaxation of the crystalline framework. One key finding is the development of transport asymmetry: when a background temperature gradient exists, the transport properties become different for propagation along the background thermal gradient and propagation against the background thermal gradient. Analysis on an endmember case shows that the transport asymmetry is associated to the competition between the diffusion and advection of pore pressure, which determines a Peclet number that depends on the temperature difference across the mush and the thermal expansion coefficients. Because the temperature in magma mushes in the crust likely increase with depth, the observed propagation asymmetry suggests some intrinsic difference between a bottom-up vs. a top-down triggering mechanism for magmatic unrest. The results from this study highlight the importance for further exploration for a more complete description of the transport properties in the crystal mush.

The synergy effect of O2 content in dielectric strength of CO2+N2+O2 ternary mixtures with constant N2 ratio is investigated from microscopic properties of the component gases. AC Breakdown voltage measurements in the ternary mixtures subjected to uniform electric fields verify the two term Boltzmann equation solutions carried out with the Bolsig + program in the ternary mixtures. The dielectric strength of the ternary mixture increases as the O2 content is increased and the effect is pronounced at certain fixed N2 component ratios in the mixtures. The experimental results are valid in the range of 1 cm-bar where the Paschen’s Law apply. For the uniform field gap, lightning impulse (LI) voltage breakdown voltages are also measured in the ternary mixtures, however the synergy effect is not significant under the present experimental parameters.

A fascinating novelclass of double perovskites materials with interesting optoelectronic and transport features have been discovered. In the current study, optoelectronics and the transport properties of Rb2LiTlX6 (X = Cl, Br) were comprehensively examined. Structure stability was confirmed by calculating tolerance factor value and Born stability criteria. At the Γ-symmetry point, direct band gaps of 2.90 eV and 1.66 eV are observed, ensuring spectral response throughout ultra-violet to visible areas and used as potential candidates for solar cell applications. These are excellent compounds for optoelectronic applications because of their low scattering of light, refractive index range approximately from 1.5 to 2, and wide absorption band in visible areas. Furthermore, thermal properties with the name electrical conductivity, thermal conductivity, Seebeck coefficient, power factor, and figure of merits of double perovskites were studied. The figure of merits (ZT) values of both compounds are 0.43, and 0.51 at room temperature, which confirms that these materials are suitable for use in thermal devices.

By virtue of the excellent plasticity and tunable transport properties, Ag2S-based materials demonstrate an intriguing prospect for flexible or hetero-shaped thermoelectric applications. Among them, Ag2S1-xTex exhibits rich and interesting variations in crystal structure, mechanical and thermoelectric transport properties. However, Te alloying obviously introduces extremely large order-disorder distributions of cations and anions, leading to quite complicated crystal structures and thermoelectric properties. Detailed composition-structure-performance correlation of Ag2S1-xTex still remains to be established. In this work, we designed and prepared a series of Ag2S1-xTex (x = 0–0.3) materials with low Te content. We discovered that the monoclinic-to-cubic phase transition occurs around x = 0.16 at room temperature. Te alloying plays a similar role as heating in facilitating this monoclinic-to-cubic phase transition, which is analyzed based on the thermodynamic principles. Compared with the monoclinic counterparts, the cubic-structured phases are more ductile and softer in mechanical properties. In addition, the cubic phases show a degenerately semiconducting behavior with higher thermoelectric performance. A maximum zT = 0.8 at 600 K and bending strain larger than 20% at room temperature were obtained in Ag2S0.7Te0.3. This work provides a useful guidance for designing Ag2S-based alloys with enhanced plasticity and high thermoelectric performance.

A full potential all-electron density functional method within generalized gradient approximation is used herein to investigate correlations of the electronic, elastic and thermo-electric transport properties of cubic copper sulphide and copper selenide. The electronic band structure and density of states suggest a metallic behaviour with a zero-energy band gap for both materials. Elastic property calculations suggest stiff materials, with bulk to shear modulus ratios of 0.35 and 0.44 for Cu2S and Cu2Se, respectively. Thermo-electric transport properties were estimated using the Boltzmann transport approach. The Seebeck coefficient, electrical conductivity, thermal conductivity and power factor all suggest a potential p-type conductivity for α-Cu2S and n-type conductivity for α-Cu2Se.

The double perovskites are promising for solar cells and other optoelectronic applications. In this article, the optoelectronic, transport characteristics of new double perovskites Ga2PdCl6, Ga2PdBr6, and Ga2PdI6 are addressed. The structural and thermodynamic stabilities have been addressed by tolerance factor, and positive frequency of phonon dispersion. The reported band gaps are 2.05 eV, 1.60 eV and 0.80 eV which increases their performance for solar cells. The Ga2PdBr6 is ideal for visible light solar cells with absorption band 400 nm–620 nm. The optical properties analyzed by dielectric constants, polarization, absorption of light, and optical losses. Thermoelectric characteristics has been explained by figure of merit (ZT) in terms of chemical potential, and kelvin temperature. The room temperature ZT (0.77, 0.76, 0.75) for Ga2PdX6 (X = Cl, Br, I) make them potential for thermoelectric applications.

Bismuth films are interesting objects for research because of the many effects occurring when the film thickness is less than 70 nm. The electronic band structure changes significantly depending on the film thickness. Consequently, by changing the film thickness, it is possible to control the physical properties of the material. The purpose of this paper is to give a brief description of the basic structural and physical properties of bismuth films. The structural properties, namely, morphology, roughness, nanoparticle size, and texture, are discussed first, followed by a description of the transport properties and the band structure. The transport properties are described using the semi-metal–semiconductor transition, which is associated with the quantum size effect. In addition, an important characteristic is a two-channel model, which allows describing the change in resistivity with temperature. The band structure of bismuth films is the most interesting part due to the anomalous effects for which there is still no unambiguous explanation. These effects include anomalous spin polarization, nontrivial topology, and zone changes near the edge of the film.

Various strategies for thermoelectric material optimization have been widely studied and used for promoting electrical transport and suppressing thermal transport. As a nontraditional method, pressure has shown great potential, as it has been applied to obtain a high thermoelectric figure of merit, but the microscopic mechanisms involved have yet to be fully explored. In this study, we focus on r-GeTe, a low-temperature phase of GeTe, and investigate the pressure effects on the electronic structure, electrical transport properties and anharmonic lattice dynamics based on density functional theory (DFT), the Boltzmann transport equations (BTEs) and perturbation theory. Electronic relaxation times are obtained based on the electron-phonon interaction and the constant relaxation time approximation. The corresponding electrical transport properties are compared with those obtained from previous experiments. Hydrostatic pressure is shown to increase valley degeneracy, decrease the band effective mass and enhance the electrical transport property. At the same time, the increase in the low-frequency phonon lifetime and phonon group velocity leads to an increase in lattice thermal conductivity under pressure. This study provides insight into r-GeTe under hydrostatic pressure and paves the way for a high-pressure strategy to optimize transport properties.

In this study, we experimentally measure the viscosity, η, and ionic conductivity, σ, of 1 mol kg−1 LiPF6 dissolved in a binary solvent of ethylene carbonate (EC) and propylene carbonate (PC) by varying the EC content from 0 to 60 vol%. Replacing EC with PC does not significantly influence on the mechanism of flow and ionic conduction. The state of solvent solvating to Li+ is analyzed using Raman spectra and 13C-NMR; the quantitative analysis suggests that the preference of EC in the Li+ solvation shell is almost similar to that of PC. The diffusion coefficient, D, of each species, Li+, PF6−, EC, and PC, is determined by pulse-gradient spin-echo NMR. In the electrolyte system dealt in this study, the molar conductivity is dominated by only the D of the charge carriers. The hydrodynamic Stokes radius of all constituent species is expressed in terms of D and η using the Stokes–Einstein relation. As for coordinated-Li+, a comparison between the Stokes radius and the van der Waals radius or the radius considering the free volume suggests that Li+ diffuses while dragging not only a coordination shell that can be spectroscopically detected but also an outer shell that binds loosely to Li+.

The new phase Ba5In2Al2Zr0.9Nb0.1O13.05 with hexagonal perovskite structure was obtained. The substitution of Zr4+ by smaller Nb5+ was accompanied by the incorporation of the oxygen interstitials and did not lead to a significant change in the lattice parameters. It was established that the investigated sample was capable for water incorporation from the gas phase, the hydration degree value was 0.24 mol H2O. IR-spectroscopy analysis defined the presence of OH−-groups with different thermal stability, which participate in different hydrogen bonds. The new phase Ba5In2Al2Zr0.9Nb0.1O13.05 demonstrates the predominant protonic conductivity at pH2O = 2·10−2 atm and Т600 °C.

Structural, vibrational and transport properties of liquid alumina at 2500 K and amorphous alumina at 300 K were studied by molecular dynamics simulations using an empirical Born-Mayer-Huggins potential with the recently optimized parameters. The investigations were conducted for the predicted densities at almost zero pressure, as well as the experimentally reported densities of 2.81 g/cm3 and 3.175 g/cm3. A detailed examination of the interatomic correlations showed that for both liquid and amorphous alumina, the short-range order was dominated by the slightly distorted (AlO4)5− tetrahedra. Vibrational density of states (VDOS) was obtained from the Fourier transform of the velocity autocorrelation functions (VACF), which exhibited broader ranges for the liquid phases compared with those for the amorphous phases. Each VDOS spectrum was divided into two primary frequency bands for both liquid and amorphous alumina. Thermal conductivities (κ) and viscosities (η) were estimated respectively through the heat-current autocorrelation functions (HCACFs) and stress autocorrelation functions (SACF) by the equilibrium molecular dynamics (EMD) simulations using the Green-Kubo relation. And the results were shown to be consistent with the experimental data, especially that κ was equal to 2.341 ± 0.039 Wm−1K−1 for amorphous alumina at 2.81 g/cm3 and 300 K, η was equal to 0.0261 ± 0.0017 Pa·s and 0.0272 ± 0.0018 Pa·s for the liquid phases at 2500 K with densities of 2.81 g/cm3 and 2.863 g/cm3, respectively. Mean squared displacements (MSDs) were employed for the self-diffusion coefficients (D) estimation.

Researching the aluminum molten salt system has always been challenging because of the high temperature and significant corrosion seen in the aluminum electrolysis industry. This paper employs ab initio molecular dynamics simulations to investigate the ionic structure and transport features of the K3AlF6-2.2NaF-AlF3 molten system. The findings indicate that the primary Al-F complex ion species present in K-rich molten salts are [AlF4]−, [AlF5]2−, and [AlF6]3−. The fluorine atom located at the bridge site constitutes around 3% of the overall composition, suggesting a rather modest degree of polymerization for the ionic structure. The relative diffusion rates of the ions in the system are as follows: sodium (Na) has the highest diffusion ability, followed by potassium (K), fluoride (F), and aluminum (Al). With the increase in K3AlF6 concentration, the distribution and diffusion coefficient of complex ions in the melt change, resulting in a decrease in the transport performance of the entire system. These fundamental research findings can contribute to the optimization of the aluminum electrolysis industry in the future.

editorial

This work presents a report on the preparation of plasticized polyvinyl alcohol PVA-based polymer electrolytes using solution cast technique and their characteristics using a number of electrochemical techniques. Electrical impedance spectroscopy (EIS), linear sweep voltammetry (LSV), and transfer number measurement (TNM) techniques were examined on the prepared films to determine the conductivity, decomposition voltage and ion transference number, respectively. The cyclic voltammetry (CV) and charge-discharging measurements were implemented on an assembled EDLC device to estimate the charge storage process and evaluate the device performance, respectively. The EIS was employed for measuring the direct current (DC) electrical conductivity of the films and calculating the ion transport parameters. The CV and charge-discharging responses were used to estimate the capacitance and stability, respectively. The influence of plasticization on the polymer electrolytes was investigated in terms of electrochemical properties. The TNM measurements were used to determine te and tion respectively. The obtained ionic transference number, tion for the electrolytes incorporated with 40 wt.% and 50 wt.% of glycerol content were found to be 0.969 and 0.944, respectively. The LSV study was used to identify the decomposition voltage of the sample. The absence of redox peaks was proved via CV technique, indicating the mechanism of the charge storing process that comprised ion accumulation at the interfacial region. The initial specific capacitance (Cs) of the fabricated EDLC displayed the value of 152.4 F/g.

For the rapid charge-discharge performance of Li-ion batteries (LIBs), ionic conductivity (σ) and Li ion transference number (t+) are important parameters of electrolytes. Electrolytes with high t+ alleviate the concentration polarization upon fast charge-discharge, and prevent the diffusion-limited mass transfer of Li+ ions. Recent studies have suggested that certain highly concentrated electrolytes exhibit better rate performances than conventional organic electrolytes despite their lower σ. However, the relationship between the transport properties (t+ and σ) of highly concentrated electrolytes and the enhanced rate performance of LIBs is yet to be elucidated. To evaluate the rate performance of LIBs with highly concentrated electrolytes in terms of transport properties, we investigated the discharge rate capability of LiCoO2 (LCO) half-cells using highly concentrated lithium bis(fluorosulfonyl)amide (Li[FSA]) electrolyte in γ-butyrolactone (GBL), acetonitrile (AN), dimethyl carbonate (DMC), and 1,2-dimethoxyethane (DME) solvents. There was a remarkable solvent dependence of t+, and the highest tLi+current of 0.67 was observed for GBL-based electrolyte measured using the very-low-frequency impedance spectroscopy (VLF–IS) method. The LCO half-cell with GBL-based electrolyte delivered higher discharge capacities than the cells with DMC- and DME-based electrolytes at high current densities. The improved rate performance in GBL-based electrolytes was attributable to enhanced Li+ ion mass transfer derived from the high tLi+current. We demonstrated the importance of tLi+current on the rate capability of LCO half-cells with highly concentrated electrolytes for high-rate battery performance.

We have investigated the Fano factor and shot noise theoretically in the confined region of the potential well of zigzag graphene nanoribbon (ZGNR). We have found that the Fano factor is approximately 1, corresponding to the minimum conductivity (σ) for both symmetrical and asymmetrical potential wells. The conductivity plot with respect to Fermi energy appears as symmetrical plateaus on both sides of zero Fermi energy. Moreover, a peak observed at zero Fermi energy in the local density of states (LDOS) confirms the edge states in the system. The transmission properties of ZGNR in the confined region of the potential well are examined using the standard tight-binding Green’s function approach. The perfect transmission observed in the confined region of the potential well shows that pnp type transistors can be made with ZGNR. We have discussed the Fano factor, shot noise, conductivity, and nanohub results in the continuation of previous results. Our results show that the presence of van-Hove singularities in the density of states (DOS) matters in the presence of edge states. The existence of these edge states is sensitive to the number of atoms considered and the nature of the potential wells. We have compared our numerical results with the results obtained from the nanohub software (CNTbands) of Purdue University.

The paper reports a sustainable, fast and efficient methodology to treat natural hemp fibers (HF) using a mechanochemical approach. Mechanical milling was used to carry out an alkaline attack on HFs for 30 min at ambient temperature. Composites HF/pectins were prepared by varying the fiber weight fraction (3%; 7.5%; 10%; 20% w/w by weight). The improvement in thermal degradation, mechanical and barrier properties to water vapor was correlated with the fiber volume fraction and mainly due to the improved fiber-matrix adhesion. The fibers–matrix interaction was then evaluated by analyzing and modeling the mechanical properties using several mathematical models: a modified Nielsen and Pukànszky and Smith models. Sorption isotherms to water vapor were analyzed through a modified Guggenheim, Anderson, de Boer (GAB) model where a new parameter, α, was introduced to consider the heterogeneity of the system. Finally, a modified Burgemman model was used to fit the experimental data and support the improvement in water diffusion with fiber loading.

One-dimensional (1D) novel pentagonal materials have gained significant attention as a new class of materials with unique properties that could influence future technologies. In this report, we studied the structural, electronic, and transport properties of 1D pentagonal PdSe2 nanotubes (p-PdSe2 NTs). The stability and electronic properties of p-PdSe2 NTs with different tube sizes and under uniaxial strain were investigated using density functional theory (DFT). The studied structures showed an indirect-to-direct bandgap transition with slight variation in the bandgap as the tube diameter increased. Specifically, (5 × 5) p-PdSe2 NT, (6 × 6) p-PdSe2 NT, (7 × 7) p-PdSe2 NT, and (8 × 8) p-PdSe2 NT are indirect bandgap semiconductors, while (9 × 9) p-PdSe2 NT exhibits a direct bandgap. In addition, under low uniaxial strain, the surveyed structures were stable and maintained the pentagonal ring structure. The structures were fragmented under tensile strain of 24%, and compression of −18% for sample (5 × 5) and −20% for sample (9 × 9). The electronic band structure and bandgap were strongly affected by uniaxial strain. The evolution of the bandgap vs. the strain was linear. The bandgap of p-PdSe2 NT experienced an indirect–direct–indirect or a direct–indirect–direct transition when axial strain was applied. A deformability effect in the current modulation was observed when the bias voltage ranged from about 1.4 to 2.0 V or from −1.2 to −2.0 V. Calculation of the field effect I–V characteristic showed that the on/off ratio was large with bias potentials from 1.5 to 2.0 V. This ratio increased when the inside of the nanotube contained a dielectric. The results of this investigation provide a better understanding of p-PdSe2 NTs, and open up potential applications in next-generation electronic devices and electromechanical sensors.

The paper addresses the problem of geomechanical effects in the vicinity of production/injection wells and their impacts on the processes of enhanced oil recovery by CO2 injection and CO2 sequestration in a partially depleted oil reservoir. In particular, it focuses on natural fracture systems and their dynamics caused by variations in the rock geomechanical state due to reservoir pressure changes during production/injection processes. The comprehensive approach to the problem requires the combined modeling of both geomechanical and flow phenomena associated with effective coupling simulations of their evolution. The paper applies such an approach to a real, partially depleted oil reservoir in Poland. An effective method of coupled geomechanical and dynamic simulations was used together with the natural boundary and initial conditions for both simulation types. In addition, typical operating conditions were applied in analyzing the processes of enhanced oil recovery by CO2 injection and CO2 sequestration. The detailed results of relevant modeling and simulations are presented and discussed focusing on various scale consequences, including the reservoir, well, and completion ones. Both general conclusions as well as the ones specific to the analyzed geological structure are drawn; they confirm the significant dependence of well performance on geomechanical effects and point out several key factors for this dependence. The conclusions specific to the analyzed structure concern fracture reactivation in tensile/hybrid failure mode caused by pressure build-up during CO2 injection and the importance of the fracture-induced aperture changes resulting from the normal stress, while the shear stress is found to be negligible.

Transport properties are one of the most crucial assets of hydrogel samples, influencing their main application potential, i.e., as drug carriers. Depending on the type of drug or the application itself, it is very important to be able to control these transport properties in an appropriate manner. This study seeks to modify these properties by adding amphiphiles, specifically lecithin. Through its self-assembly, lecithin modifies the inner structure of the hydrogel, which affects its properties, especially the transport ones. In the proposed paper, these properties are studied mainly using various probes (organic dyes) to effectively simulate drugs in simple release diffusion experiments controlled by UV-Vis spectrophotometry. Scanning electron microscopy was used to help characterize the diffusion systems. The effects of lecithin and its concentrations, as well as the effects of variously charged model drugs, were discussed. Lecithin decreases the values of the diffusion coefficient independently of the dye used and the type of crosslinking. The ability to influence transport properties is better observed in xerogel samples. The results, complementing previously published conclusions, showed that lecithin can alter a hydrogel’s structure and therefore its transport properties.

The development of solid oxide fuel cells operating at medium temperatures (500–700 °C and even lower) requires the search for proton conductors based on complex oxides that would have a wide range of required properties. This task stimulates the search for new promising phases with proton conductivity. The new hexagonal perovskite-related compound Ba7In6Al2O19 was synthesized by the solid-state method. The phase was characterized by powder X-ray diffraction, thermogravimetric analysis, FT-IR spectroscopy, and impedance spectroscopy (in a wide range of temperatures, and partial pressures of oxygen at various atmospheric humidities). The investigated phase had a hexagonal structure with a space group of P63/mmc; the lattice parameters for Ba7In6Al2O19 are a = 5.921(2) Å, c = 37.717(4) Å. The phase is capable of reversible hydration and incorporates up to 0.15 mol H2O. IR-data confirmed that protons in the hydrated compound are presented in the form of OH–-groups. Electrical conductivity data showed that the sample exhibited dominant oxygen-ion conductivity below 500 °C in dry air and dominant proton conductivity below 600 °C in wet air.

Si1–xGex alloys are among the most used materials for power electronics and quantum technology. In most engineering models the parameters used to simulate the material and its electronic transport properties are derived from experimental results using simple semiempirical approaches. In this paper, we present a high-throughput study of the electron transport properties in Si1–xGex alloys, based on the combination of atomistic first principles calculations and statistical analysis. Our results clarify the effects of the Ge concentration and of disorder on the properties of the Si1–xGex alloy. We discuss the results in comparison with existing semiempirical methods and we provide a Ge-dependent set of transport parameters that can be used in device modeling.

The Density Functional Theory (DFT) with an approximation of generalised gradient is used for the study of elastic, thermodynamic and transport properties and for that of structural stability of ternary Half-Heuslers compounds X(X=Co, Rh and Ir)MnAs. This first predictive study of this compounds determines the mechanical properties such that the compression, shearing, Young modulla and Poisson coefficient without omitting the checking parameters of the nature of these compounds such that hardness, Zener anisotropic facto rand Cauchy pressure. The Pugh ratio and Poisson coefficient have allowed the identification of ductile nature of these compounds. The speed of sound and Debye temperature of these compounds has also been estimated from the elastic constants. The thermodynamic properties have been calculated as well for a pressure interval from zero to 25 GPa. The effect of chemical potential variation on Seebeck coefficient, electric, thermal and electronic conductivities, the power and merit factors have also been studied for different temperatures (300, 600, 900°K), so that these alloys can be better potential candidates for thermoelectric applications.