Miracle-dz/UniFAR-FTUs huggingface dataset:
Evaluations of Phases and Vacancy Formation Energies in KNbO3 by First-Principles Calculation

In order to clarify thermodynamic relationships of the various phases of KNbO3, enthalpies of formation for cubic (Pm3m), tetragonal (P4mm), orthorhombic (Bmm2) and rhombohedral (R3m) phases of KNbO3 were calculated using a plane-wave pseudopotential method within a density functional formalism. The KNbO3 phase with the lowest symmetry was found to have the lowest enthalpy of formation. Moreover, we quantitatively evaluated the formation energies of neutral vacancies in KNbO3 as functions of the atomic chemical potentials of the constituent elements by the use of the same procedure. Relaxation of the first- and the second-neighbor atoms around the vacancy was considered in a 40-atom supercell. The formation energy of a K vacancy was found to be the lowest under an oxidizing atmosphere and that of an O vacancy was found to be the lowest under a reducing atmosphere. The formation energy of a Nb vacancy was the highest under both oxygen-rich and -poor conditions. These results are in agreement with the empirical rule that B site defects in perovskite-type oxide do not exist. These results are discussed on the basis of the band structure of KNbO3.
Structural and electronic properties of Xe

Using different density-functional methods, dimers, chains, monolayers, and crystals of Xe are studied. In contrast to most of the earlier studies on crystalline Xe, this one concentrates on structures with expanded lattices compared with equilibrium. In order to make a comparison with experimental photoelectron information, the variation of the band structures and density of states with distance is analysed in detail. Here, the calculations give results that are mutually consistent and in agreement with some other theoretical works, but which show some differences from other theoretical and some experimental studies. The differences that are observed for chains and monolayers, which experimentally are produced on some substrate, may be due to substrate-Xe interactions. In addition, we explore how spin-orbit couplings influence the results, and the differences between using a local-density and a generalized-gradient approximation are studied. For those systems where other information on the optimized bond length exists it is found that the density-functional calculations are inaccurate. When a comparison is possible, the bonds are found to be too short. Moreover, the calculations predict in all cases the existence of stable structures.
The axial dispersed plug flow model for continuous counter‐current adsorbers

On a etabli l'expression theorique de la hauteur equivalente a un plateau theorique, et on l'a compare a l'expression analogue pour un systeme de chromatographie. Le rapport de ces grandeurs est generalement 0,5 dans les conditions pratiques de fonctionnement, mais la relation precise depend des nombres de Peclet et de Stanton ainsi que du rapport des debits a contre-courant
Mass and Energy Balances of Wet Torrefaction of Lignocellulosic Biomass

Solid handling of diverse lignocellulosic biomass feedstock is very challenging for thermochemical conversion to renewable fuels. Wet torrefaction is a pretreatment process to convert biomass to energy-dense solid fuel, with relatively uniform handling characteristics. The fuel value of the produced solid may be as much as 36% higher than that of the original biomass. In the process, biomass is reacted with hot compressed water at the temperature of 200−260 °C. The mass and energy balance in wet torrefaction were established for these conditions. Products include pretreated solid, precipitates (simple sugars and sugar derivatives), volatile acids, and gases (carbon dioxide). With increasing temperature, the mass of the solid decreases, the fuel value of the solid increases, and the quantity of gas increases. The heat of reaction for each temperature was estimated from an energy balance. The uncertainty analysis also showed that the temperature slightly affected the heat of reaction, which is very close to.
High-pressure phase transitions in tetrakis(trimethylsilyl)silane Si[Si(CH3)3]4

The compound tetrakis(trimethylsilyl)silane Si[Si(CH 3)3]4 (TSi) has been studied at room temperature for pressures up to 21.5(1) GPa, using X-ray powder diffraction with synchrotron radiation. Three different phases are reported in the investigated pressure range. The c.c. p.-type structure is stable up to a pressure of 0.19(1) GPa ( , a = 13.5211(1) Å, V = 2471.95(1) Å3, Z = 4 at 0.02(1) GPa). It shows a severe orientational disorder of the molecules. At pressures 0.19(1)–0.71(1) GPa a monoclinic phase (HP1) is found with space group P 21/n and Z = 8 (a = 17.746(1) Å, b = 16.098(1) Å, c = 16.871(1) Å, γ = 111.437(5)ˆ and V = 4486.3(8) Å3 at 0.24(1) GPa). Another monoclinic phase (HP2) exists at pressures 0.52(1)–8.67(5) GPa. This phase has a smaller unit cell than the HP1 phase with Z = 2 (a = 8.3778(8) Å, b = 9.1050(7) Å, c = 13.3024(8) Å, γ = 111.63(1)ˆ and V = 943.22(6) Å3 at 1.73(2) GPa). The pressure dependencies of the unit-cell volumes are successfully described by Murnaghan or Vinet-type equations of state. The structures at different pressures and temperatures of TSi and related compounds are described as distorted superstructures of the c.c. p. arrangement. The occurrence of different superstructures is rationalized as the result of an optimized packing of ordered molecules of various shapes.
Mass Transfer in the Mobile and Stationary Phases in Micellar Liquid Chromatography

The retention behaviors of a series of solutes having a wide range of polarity were evaluated for normal retention behavior in micellar chromatography and then used to measure column efficiencies as a function of the concentration of sodium dodecyl sulfate (0-0.3 mol L -1 ), both in the presence and absence of small concentrations of 1-propanol (0-0.8 mol L -1 )
Adsorption of fluoride on Mg/Fe layered double hydroxides material prepared via hydrothermal process

A nitrate containing Mg/Fe layered double hydroxides (Mg/Fe-LDHs) material was prepared via hydrothermal process and the calcination product (Mg/Fe-LDHO) was used as adsorbent to remove fluoride from aqueous solution. Scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform-infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA) and pHpzc analysis were used to characterize the samples. Inductively coupled plasma-atomic emission spectrometry (ICP-AES) was employed to analyse the dissolution of the metal ions from the synthesized adsorbent and commercial activated alumina respectively. Compared with commercial activated alumina, the synthesized adsorbent entirely avoided the potential risk of alumina and had a lower leakage of metal ions. A series of batch experiments were performed to investigate the effects of various experimental parameters, such as calcination temperature, adsorbent dosage, fluoride concentration, initial pH, contact time, adsorption temperature and co-existing anions. The results showed that 270 °C was the optimal calcination temperature. The adsorption rapidly occurred in the initial 45 min and adsorption equilibrium was established within 2.5 h. Maximum desorption of 97.2% was achieved in the fluoride desorption studies at different pH. The adsorption data were well described by the pseudo-second-order kinetics model and the Langmuir isotherm model, and the adsorption capacity calculated by Langmuir equation was 28.65 mg g−1. In addition, the effects of co-existing anions on the adsorption capacity declined with the following order: PO43− > CO32− > SO42− > NO3− > Cl−. It can be concluded that the synthetic adsorbent in this study is a promising material for fluoride removal from solutions.
Reactions of sodium oxide with the oxides VO2, V2O3, VO, and vanadium metal

The reactions of sodium oxide with vanadium metal and its lower oxides are described for different molar ratios of reactants. All reaction products are identified by powder X-ray crystallography and the reaction temperature determined by differential thermal analysis.No ternary oxides containing vanadium in the 4+ state were formed in the reactions of sodium oxide with vanadium dioxide; an equimolar mixture gave NaVO2 and Na3VO4. The ternary oxide NaVO2 was prepared by the reaction of vanadium(III) oxide with sodium oxide in equimolar proportions, but sodium orthovanadate Na3VO4 was formed at higher sodium oxide concentrations. This product was also formed from reactions of the monoxide and vanadium metal with sodium oxide.
Molecular Motion in Free-Standing Thin Films of Poly(methyl methacrylate), Poly(4-tert-butylstyrene), Poly(α-methylstyrene), and Poly(2-vinylpyridine)

A photobleaching technique has been used to measure the reorientation of dilute fluorescent probes in free-standing polymer films from 7 nm to 20 μm thick. Similar to our previous report on free-standing polystyrene films, two subsets of probes with distinct dynamics were observed in free-standing poly(methyl methacrylate) films. The more mobile subset of probes is consistently interpreted in terms of a surface layer, and the thickness of the mobile surface layer is shown to increase with temperature. Poly(methyl methacrylate) has a mobile surface layer thickness of 4 nm at the bulk Tg. Similar measurements on free-standing poly(2-vinylpyridine) and poly(4-tert-butylstyrene) films indicate mobile surface layer thicknesses from 7 to 10 nm at their bulk Tg values, similar to the 7 nm value previously reported for polystyrene. In contrast to the other four polymers, free-standing poly(α-methylstyrene) films show no evidence of a mobile surface layer. We interpret these results in terms of contributions from .
Specific Heat and ac Susceptibility Studies on Ruthenium Pyrochlores R2Ru2O7 (R=Rare Earths)

Abstract Specific heat and ac susceptibility measurements were performed for R2Ru2O7 (R=Y, Pr, Nd, Sm, Eu, and Lu). For Y2Ru2O7 and Lu2Ru2O7, a λ-type specific heat anomaly has been observed at 77 and 78 K, respectively, which is consistent with the magnetic transition found in their magnetic susceptibility vs temperature curves. In the real part of the ac susceptibilities, small cusps are observed at 78 K for Y2Ru2O7 and at 80 K for Lu2Ru2O7. Both the real part and the imaginary part of the ac susceptibilities are independent of frequency, indicating that these compounds are not in the ordinary spin-glass. Similar large jumps of specific heat are observed at 162, 143, 124, and 118 K for R2Ru2O7 (R=Pr, Nd, Sm, and Eu). For Sm2Ru2O7 and Eu2Ru2O7, no specific heat anomaly has been found at lower temperatures, although magnetic anomaly was observed at ca. 20 K in their dc susceptibility vs temperature curves. ac susceptibility measurements show that both the real and the imaginary susceptibilities show anomaly at ca. 20 K and this temperature decreases with decreasing frequency. These results strongly indicate that the transition observed at ca. 20 K is the spin-glass one. The experimental results on Nd2Ru2O7 show that magnetic properties of this compound are complicated.
Pressure-volume equation of state for chromite and magnesiochromite: A single-crystal X-ray diffraction investigation

Abstract The pressure-volume equation of state for the two spinel end-member compositions chromite Fe- Cr2O4 and magnesiochromite MgCr2O4 was determined for flux-grown synthetic single crystals at room temperature up to 8.2 and 9.2 GPa, respectively, by single-crystal X-ray diffraction using a diamondanvil cell. The pressure-volume data show that the linear volume compressibility (here used only for purpose of comparison), calculated as βV = |[(ΔV/V0)/ΔP]|, is 0.00468 and 0.00470 GPa-1, for chromite and magnesiochromite, respectively, with a negligible difference below 0.5%. The experimental data were fitted to a third-order Birch-Murnaghan equation of state (BM3) allowing a simultaneous refining of the following coefficients: V0 = 588.47(4) Å3, KT0 = 184.8(1.7) GPa, and K′ = 6.1(5) for chromite and V0 = 579.30(4) Å3, KT0 = 182.5(1.4) GPa, and K′ = 5.8(4) for magnesiochromite. The difference in KT0 is reduced to <1.5% going from Fe to Mg end-member composition, whereas the first pressure derivative seems not to be affected by the chemical variability. The limited difference in the equation of state coefficients recorded for FeCr2O4 and MgCr2O4 allowed us to fit the pressurevolume data of both to a single BM3 equation, resulting in a KT0 = 184.4(2.2) GPa and K′ = 5.7(6).
PISTACHIO RESPONSES TO SALT STRESS AT VARIED LEVELS OF MAGNESIUM

Crop production in many parts of the world is increasingly affected by soil salinization, especially in the irrigated fields of arid and semi-arid regions. The effects of four magnesium levels [0, 0.5, 1, and 22 millliMolar (mM) magnesium as magnesium sulfate (MgSO4.5H2O)], and three salinity levels [0, 45 and 90 mM sodium chloride (NaCl)] on growth and the chemical composition of pistachio seedlings (Pistacia vera L.) cv. ‘Badami-e-Zarand’ was studied in sand culture under greenhouse conditions. The experiment was set up as a completely randomized design (CRD) with four replications. After 28 weeks the growth parameters of biomass, leaf number, leaf area and stem height were measured. The results demonstrated that salinity decreased biomass, leaf area and stem height; the application of 2 mM magnesium (Mg) significantly reduced biomass, leaf number, leaf area and stem height; salinity stress increased concentrations of sodium (Na) and potassium (K) in shoot as well as Na concentration in root; however, it decreased Mg and calcium (Ca) concentrations in shoot, as well as Mg, Ca, and K concentrations in root. The application of 2 mM Mg reduced K and Ca concentrations in shoot and Na and K concentrations in root.
Kinetics of the Oxidation of 5-Vinyl-2-norbornene under Two-Phase-Transfer Catalysis Conditions

The phase-transfer catalytic epoxidation of 5-vinyl-2-norbornene under the presence of cocatalyst and oxidant agent in an organic/aqueous two-phase medium was investigated. Quaternary ammonium salts, sodium tungstate and phosphoric acid, and hydrogen peroxide were used as the phase-transfer catalyst, cocatalysts, and oxidant agent, respectively. The purpose of this work is to examine the oxidation of the two double bonds of 5-vinyl-2-norbornene and the reaction mechanism and to confirm the reaction steps. The roles of quaternary ammonium salt, sodium tungstate and phosphoric acid and hydrogen peroxide in the formation of the complex, which acts as the active intermediate, were identified from the experimental observation. Only a 2,3-epoxy-5-vinylnorbornane single product was produced from the reaction. Based on the experimental results, a rational mechanism of the catalytic epoxidation is proposed. The kinetics of the catalytic epoxidation in the two-phase solution are studied in order to obtain a rate ex.
Turbulence Intensity of Mixing in Relation to Flocculation

An assessment has been made of fluid turbulence intensities and local velocities throughout a 1‐L square reactor in relation to flocculation efficiency. Measurements have been taken using laser‐Doppler anemometry for three types of stirrer, and aluminum sulphate has been used as the coagulant for a synthetic raw water based on kaolin as suspension with controlled alkalinity. Stirrer speeds ranging from 16 to 100 rpm were adopted, and the torque applied to the fluid was measured directly. Turbulence intensity is shown to be an alternative measure of flocculation efficiency to velocity gradient or power input. The power input required for minimum turbidities is much the same for all stirrers, but where optimum conditions cannot be predetermined, a stirrer that extends throughout the volume of the reactor and has sharp‐edged blades is shown to be more versatile than the other types.
What Price Quality? An Investigation into the Prediction of Wine-quality Ratings

The paper uses the wine-quality ratings devised by James Halliday in his book Australia and New Zealand Wine Companion 2000 as the dependent variable in a regression-based analysis. Equations are developed for eight different wine varieties in Australia: Chardonnay, Riesling, Semillon, Sauvignon Blanc, Cabernet, Shiraz, Merlot and Pinot Noir. The independent variables having the greatest correlation with the quality rating include price range, winery rating, vintage, size of winery and region. The importance of these independent variables varies with the variety and some traditional indicators of quality, such as region, do not seem to have as great a correlation with quality as might be expected.
Defect-related vibrational and photoluminescence spectroscopy of a codoped ZnO : Al : N film

Fourier transform infrared absorption and photoluminescence (PL) spectroscopy were used to investigate the defects in a codoped ZnO : Al : N film grown on a Si (111) substrate. Two broad vibrational modes around 3000 and 3120 cm−1 were found, which may be attributed to the formation of N–H bonds in different configurations. The room temperature PL spectrum of the ZnO : Al : N film exhibited two dominant emissions centred at 3.04 and 2.77 eV. PL decay and x-ray photoelectron spectroscopy results suggested that the 3.04 eV emission is not likely due to zinc vacancy. We assumed that it might correlate with the N-related defect. The 2.77 eV emission was tentatively assigned to recombination involving an unknown deep localized defect.
Ordering and the nature of the spin flop phase transition in MnPS3

Powder diffraction patterns were measured on a high quality sample of manganese thiophosphate, MnPS3 , at temperatures between 2 and 120 K and magnetic fields between 0 and 60 kOe. In zero field, the magnetic moments in MnPS3 are collinear and normal to the ab planes. On applying a sufficiently large magnetic field along the normal to the ab plane, it was found that the moments flop towards the b axis, in agreement with a dipole-dipole interaction model for the anisotropy. The width of this transition was found to be greater than 20 kOe. No evidence for critical fluctuations was seen during the spin flop phase transition.
On sheath energization and Ohmic heating in sputtering magnetrons

In most models of sputtering magnetrons, the mechanism for energizing the electrons in the discharge is assumed to be sheath energization. In this process, secondary emitted electrons from the cathode surface are accelerated across the cathode sheath into the plasma, where they either ionize directly or transfer energy to the local lower energy electron population that subsequently ionizes the gas. In this work, we present new modeling results in support of an alternative electron energization mechanism. A model is experimentally constrained, by a fitting procedure, to match a set of experimental data taken over a large range in discharge powers in a high-power impulse magnetron sputtering (HiPIMS) device. When the model is matched to real data in this way, one finding is that the discharge can run with high power and large gas rarefaction without involving the mechanism of secondary electron emission by twice-ionized sputtered metal. The reason for this is that direct Ohmic heating of the plasma electrons is found to dominate over sheath energization by typically an order of magnitude. This holds from low power densities, as typical for dc magnetrons, to so high powers that the discharge is close to self-sputtering, i.e. dominated by the ionized vapor of the sputtered gas. The location of Ohmic heating is identified as an extended presheath with a potential drop of typically 100–150 V. Such a feature, here indirectly derived from modeling, is in agreement with probe measurements of the potential profiles in other HiPIMS experiments, as well as in conventional dc magnetrons.
Ordered Mesoporous Carbon Composite Films Containing Cobalt Oxide and Vanadia for Electrochemical Applications

Mesoporous carbon composite thin films (<500 nm) containing cobalt and vanadium oxide were synthesized by triconstituent self-assembly using Pluronic F127 as template, phenol-formaldehyde oligomer (resol) as carbonizable precursor, and cobalt (or vanadyl) acetylacetonate (acac) for the metal source. The ordered mesostructure of the composite films was confirmed by both X-ray diffraction (XRD) and transmission electron microscopy (TEM). During pyrolysis at 800 °C to carbonize the film, the d-spacing decreases significantly because of uniaxial contraction; however addition of Co/V content leads to a decrease in the contraction from approximately 68% to 50%, which indicates the Co/V mechanically strengthens the framework. The decrease in contraction also leads to an increase in the average pore size by as much as 60%. Nanoparticles are found to be dispersed within the continuous carbon framework from both high resolution (HR)-TEM and scanning transmission electron microscopy (STEM); small sub-2 nm particles .
Topotaxial Formation of Mg4Nb2O9 and MgNb2O6 Thin Films on MgO (001) Single Crystals by Vapor–Solid Reaction

Thin-film solid-state reactions in the system MgO–Nb2O5 are experimentally investigated. MgO (001) substrates are subjected to Nb-O vapor at different temperatures in high vacuum. Thin films containing the phases Mg4Nb2O9 and MgNb2O6 are formed by a vapor–solid reaction between the Nb-O vapor and the substrate. The crystallographic orientations of these phases are studied by X-ray diffractometry including pole figure analysis. Mg4Nb2O9 grows (11.4)-, (11.6)-, and (11.9)-oriented, whereas MgNb2O6 grows with a preferential (241) orientation. The crystallographic relationships and their origins are discussed.
Superprotonic high temperature phase and refinement of the low temperature structure of CsHSeO4

Abstract The crystal structure of the high temperature superprotonic phase of CsHSeO4-I (tI28) has been investigated by single crystal X-ray diffraction at 408 K. It crystallizes tetragonal, a = 5.880(1), c = 14.415(3) Å, V = 498.4(2) Å3, Z = 4, space group I41/amd. In the SeO4 tetrahedron, the Se-O distance is 1.66 Å after correction for libration. A layer-like hydrogen bonding system is suggested. The low temperature structure, CsHSeO4-II(mP28), was refined from X-ray diffraction data with an accuracy which made it possible to localize the H atom. Crystallographic relations between the two phases during the phase transition are discussed.
Availability of soil boron fractions to M.26 apple rootstock

Abstract The availability of various boron (B) fractions in soil to M.26 apple (Malus spp.) rootstock was examined. The study was carried out in a greenhouse on soils with diverse chemical and physical properties. The following B fractions were determined: (i) B in soil solution, (ii) B non‐specifically adsorbed on soil surface, (iii) B specifically adsorbed on soil colloid surfaces, (iv) B occluded in Mn oxyhydroxides, (v) B occluded in noncrystalline aluminum (Al) and iron (Fe) oxides, (vi) B occluded in crystalline Al and Fe oxides, (vii) B fixed with soil silicates, and (viii) total soil B. In the studied soils there were: 0.07–0.17 mg kg‐1 B in soil solution, 0.01–0.03 mg kg‐1 B non‐specifically adsorbed on soil surface, 0.04–0.08 mg kg‐1 B specifically adsorbed on soil colloid surfaces, 0.28–0.67 mg kg‐1 B occluded in manganese (Mn) oxides, 4.03–17.22 mg kg‐1 B occluded in noncrystalline Al and Fe oxides, 8.93–50.62 mg kg‐1 B occluded in crystalline Al and Fe oxides, 12.2–42.5 mg kg‐1 B fixed with soil silicate, and 52.9–82.2 mg kg‐1 total B. Simple correlation analysis showed positive correlation between B contents in M.26 apple rootstocks and amounts of B in soil solution (r=0.77), B non‐specifically adsorbed on soil colloid surfaces (r=0.65), B specifically adsorbed on soil surface (r=0.76) and B occluded in Mn oxyhydroxides (r=0.77). No relation was found between plant B contents and amounts of B occluded in non‐crystalline and crystalline Al and Fe oxides, B fixed with soil silicates and total B. The results indicated that extraction of B by 0.1 M NH2OH HCl solution adequately represented amounts of B in soil solution, B non‐specifically and specifically adsorbed on soil compound surfaces and B occluded in Mn oxyhydroxides to assess availability of B to apple trees.