Te Mixtures Research Articles

Biological activity of the mixture trinexapac ethyl and prohexadione calcium used with adjuvants in the winter wheat crops

Field experiments were conducted in 2019–2020 in the cultivation of winter wheat of the KWS Ozon variety. The growth retardant trinexapac ethyl + prohexadione calcium (TE + Pca) and its mixtures with adjuvants and citric acid were used in the BBCH 32/33 phase of winter wheat. The effectiveness of the growth retardant depended on the dose of the preparation, the type of adjuvant, and weather conditions. Lower average daily air temperatures favored the effectiveness of the full dose of the preparation. Different relationships were noted in variants in which TE + Pca was used at a reduced dose together with adjuvants and citric acid. Among the tested variants, the greatest shortening of the canopy was achieved after the use of a mixture of the retardant and the AS (ammonium salts of polybasic acids) adjuvant compared to the control and plots treated with a lower dose of the preparation. The method of application of the tested agent in most combinations did not have a significant impact on the yield and quality of the obtained grain in both years of the study. In the case of the mixture of TE + Pca retardant with AS adjuvant, inconclusive results were obtained. In 2019, a significant reduction in the weight of one thousand seeds was recorded compared to the control variant.

Crystal Structure and Magnetism of Fe1−xTe (x=0.31)

AbstractReaction of iron‐tellurium mixtures in the composition range from Fe0.41Te0.59 to Fe0.43Te0.57 followed by quenching to ambient temperature yields the high‐temperature δ phase Fe1−xTe (0.25<x<0.31). Single crystals of δ phase Fe1−xTe, with x=0.31(1), are obtained by reacting Fe−Te mixtures with nominal composition Fe0.43Te0.57 in closed ampoules at 973 K for 15 days before quenching to ambient temperature. In accordance with the chemical transport behavior of other phases in the iron‐tellurium system, the refined composition of the single crystals Fe1−xTe with x=0.31(1) suggests that crystallization and growth preferably occur in the tellurium‐rich part of the homogeneity range.The resulting crystals adopt a monoclinic crystal structure with unit cell parameters a=6.645(2) Å, b=3.8409(6) Å, c=11.314(3) Å, β=90.47(1)°, Z=4 (space group I2/m, non‐standard setting of C2/m). Single crystal structure refinement reveals a NiAs motif with partial occupation in every second iron layer along [001]. Magnetic susceptibility measurements indicate antiferromagnetic order below 400 K.

Chemical Reactions and Phase Stabilities in the Si-Te System at High Pressures and High Temperatures.

Chemical reactions and phase stabilities in the Si-Te system at high pressures were explored using in situ angle-dispersive synchrotron powder diffraction in a large-volume multianvil press together with density functional theory-based calculations. Cubic and rhombohedrally distorted clathrates, with the general formula Te8@(Si38Te8) and wide compositional range, preceded by a hexagonal phase with the composition Si0.14Te, are formed for different mixtures of Si and Te as starting materials. Si0.14Te, with the structural formula Te2(Te0.74Si0.26)3(Te0.94Si0.06)3, is the very first chalcogenide with the Mn5Si3-type structure. Silicon sesquitelluride α-Si2Te3 decomposes into a mixture of phases that includes the clathrate and hexagonal phases at high pressures and high temperatures. The higher the pressure, the lower the temperature for the two phases to occur. Regardless of the starting compositions, only the clathrate is quenched to atmospheric conditions, while the hexagonal phase amorphizes on decompression. The rhombohedral clathrates Te8@(Si38Te8) form on quenching of the cubic phases to ambient conditions. There is a high degree of interchangeability of Si and Te not only in the clathrates but also in the Mn5Si3-type structure. The theoretical calculations of enthalpies indicate that the reported decomposition of α-Si2Te3 is energetically favorable over its transformation to another polymorph of the A2X3 type at extreme conditions.

Thermoelectric properties of medium-entropy PbSbTeSe alloy prepared by reactive spark plasma sintering

Reactive spark plasma sintering combining the synthesis and densification stages has been at the first time applied to prepare medium-entropy grained PbSbTeSe alloy. This alloy is prospect medium-temperature p-type thermoelectric. Self-propagating high-temperature synthesis in initial mixture of elemental Pb, Sb, Te and Se powders, resulting in synthesis of single-phased PbSbTeSe, was stage of synthesis. Lattice thermal conductivity of the alloy is very low (∼0.7 at ∼ 755 K). Owing to this low lattice thermal conductivity, thermoelectric performance of PbSbTeSe alloy is promising . Highest thermoelectric figure-of-merit equal to ∼ 0.43 is observed at ∼ 720 K. Anomalies of thermoelectric properties were found at ∼ 490 K. These anomalies can be related to specific features of energy bands, consisting of two valence bands, which are close in energy.

Synthesis and Thermodynamic Investigation of Energy Materials in the Ag-Te-Cl System by the Solid-State Galvanic Cells

Discoveries of new energy materials with unique properties and wider thermal stability ranges enable sustainable developments toward a low-carbon society. In this work, phase stabilities and thermodynamic properties of selected compounds in the Ag-Te-Cl system with potential application as energy materials have been critically reviewed and experimentally investigated. Based on the literature data on phase formations in the AgCl-Ag2Te-Te part of the Ag-Te-Cl system and the results of electromotive force (EMF) measurements in this work, formations of the Ag19Te6Cl7, Ag10Te4Cl3, Ag5Te2Cl, and Ag23Te12Cl compounds below 500 K were established. The EMF measurements were performed in carefully built galvanic cells with positive electrodes prepared from finely ground mixtures of pure substances Ag, Te, and AgCl. Based on the temperature dependences of the EMF of the cells, the standard thermodynamic quantities of the ternary compounds of the Ag-Te-Cl system were experimentally determined for the first time.

DC Glow Discharge Plasma Characteristics in Ar/O2 Gas Mixture

In this article, the effects of the O2 ratio on the electrical characteristics, including the I-V characteristic curve, Panchen’s curve, and I-P curve, were tested in a sample of O2/Ar gaseous mixture . The sample was produced by plasma-based DC magnetron sputtering with niobium metal as a target material. The inter-electrode spacing value was 4 cm. Plasma diagnosis via the Optical Emission Spectroscopy (OES) method was used to achieve Te and Ne mixture values of 20 %, 30 %, 50%, and 70% in the Ar/O2 system. The results showed that the discharge is operating in the abnormal glow region and the discharge current was decreased by increasing O2 percentage. In addition, the experimental results showed that the discharge is optimal at 30% gas ratio. It was found that the electron temperature was decreased with increasing working pressure and increased with increasing the O2 percentage, while electron density was increased with increasing both working gas pressure and O2 percentage.

Non-activation synthesis and thermodynamic properties of ternary compounds of the Ag–Te–Br system

Based on the literature data on the phase formation of the Ag–Te–Br system in the part AgBr–Ag2Te–Te (I) and the results of the electromotive force (EMF) measurements of the electrochemical cells (ECCs) the alleged scheme division of (I) into 10 three-phase regions was analyzed. The overall potential-forming reactions were expressed for the phase regions AgBr–Ag19Te6Br7–Te, Ag19Te6Br7–Ag3TeBr–Te, Ag3TeBr–Ag10Te4Br3–Te, Ag3TeBr–Ag5Te2Br–Ag10Te4Br3, Ag5Te2Br–Ag2Te–Ag23Te12Br, and Ag10Te4Br3–Ag23Te12Br–Te. Reactions were performed by applying ECCs of the type (−) IE | Ag | Solid-state electrolyte | R(Ag+) | PE | IE (+), where IE is the inert electrode (graphite), Ag is the negative (left) electrode, PE is the positive (right) electrode, R(Ag+) is the region of Ag+ diffusion into PE. PEs of ECCs were prepared from finely ground non-equilibrium mixtures of pure components Ag, Te, and AgBr. The component ratios were determined from the equations of the potential-forming reactions in respective phase regions. Non-activation synthesis of the equilibrium set of phases was performed in the R(Ag+) region of ECCs. The Ag+ ions displaced from the left to the right electrode for thermodynamic reasons, act as the nucleation centers for stable compounds and as the catalysts for the low-temperature synthesis of an equilibrium set of phases. The synthesis duration of the initial mixture of phases with a particle size ∼5 μm and T = 500 K is under ≤5 h. Linear dependences ЕMF vs T of ECCs between T=(440 and 500) K were used for calculations of the standard values of the Gibbs energies, enthalpies, and entropies of equilibrium compounds in (I) consisting of Ag19Te6Br7, Ag3TeBr, Ag10Te4Br3, Ag5Te2Br, and Ag23Te12Br. The agreement calculated values of the Gibbs energy of the Ag23Te12Br compound in two different three-phase regions Ag5Te2Br–Ag2Te–Ag23Te12Br and Ag10Te4Br3–Ag23Te12Br–Te confirms the correctness of the alleged scheme division of (I).

Experimental observation of density fluctuations in liquid metals associated with liquid–liquid, liquid–gas and metal–nonmetal transitions

We have developed a special technique and succeeded to carry out small-angle x-ray scattering measurements for some liquid metal systems. The purpose is to investigate effects of transitions such as liquid–liquid (LLT), liquid–gas (LGT) and metal–nonmetal (MNMT) transitions on mesoscopic density fluctuations in liquids. In liquid Te systems (Se–Te and Ge–Te mixtures), which show continuous LLT accompanying MNMT, parameters of density fluctuations show maxima almost in the middle of the transition, both in strength and spatial size. This work (and Kajihara et al 2012 Phys. Rev. B86 214202) was the first direct observation that density fluctuations exhibit maximum corresponding to LLT. However in this study, we could not clearly separate the effects of LLT and MNMT on the observed density fluctuations. Thus, we also investigated fluid Hg under high pressure and high temperature conditions, which shows MNMT near a critical point of LGT, to investigate how MNMT affects them. We observed distinct density fluctuations; a strength and a correlation length of them show maxima at around a critical isochore of LGT, and the former is basically consistent with a phase diagram (compressibility) of LGT; they do not show any peaks at MNMT region. Precise analysis revealed that MNMT only affects a shift of another parameter, a short-range correlation length. These results in fluid Hg indicate that the density fluctuations are mainly derived from a critical phenomena of LGT and MNMT does not play any critical role on them. We believe that the latter conclusion also holds true for liquid Te systems; MNMT plays no important role on the density fluctuations in liquid Te systems and LLT is the main origin of them.

Gaseous toluene, ethylbenzene, and xylene mixture removal in a microbial fuel cell: Performance, biofilm characteristics, and mechanisms

Microbial fuel cells (MFCs) are regarded as promising alternatives to anaerobic benzene, toluene, ethylbenzene, and xylene (BTEX) mineralization due to the enhancement of microbial degradation rate caused by bioanodes. In this research, a dual-chambered MFC was employed to evaluate the removal efficiency and power generation of single TE(o-X) or of dual or ternary TE(o-X) mixtures. Individually, TE(o-X) was readily biodegradable with a removal efficiency of 94.8%, 86.3%, and 71.6%, respectively, but the presence of toluene and o-xylene exhibited an adverse influence on the degradation of other mixed components. The o-xylene has the greatest inhibitory effect on microbial activity, as evidenced by laser scanning confocal microscope images. Microbial community analysis revealed that exoelectrogens prevailed in the absence of the o-xylene. Shifting the feeding gas from toluene to another individual gas or mixture caused the quantities of the exoelectrogens to gradually decrease. Moreover, the o-xylene degrader of Alicycliphilus sp. were prevailed from ~17.7% to ~60.3% in presence of the o-xylene. In addition, the observation of the nanowire/pili using scanning electron microscope images and cyclic voltammetry analysis revealed that the electrons produced were transferred to the anode directly.

Phase Transition Mechanism of Fe1.1Se0.5Te0.5 Fabricated by High-Energy Ball Milling Aided Sintering Method

We report the phase transition mechanism of Fe1.1Se0.5Te0.5 fabricated by the high-energy ball milling (HEBM) aided sintering method, which was achieved by multistep quenching heat treatment process. The precursor powders, composed of Fe and (Se, Te)ss, were synthesized via an HEBM method for 2 h using Fe, Se, and Te mixture powders. Under the sintering temperature of 400 °C, the two compositions began to diffuse into each other and Fe(Se, Te)2 phase with uniform Se and Te distribution was formed directly. With further increasing temperature to 500 °C, tetragonal β-Fe(Se, Te) phase was obtained owing to the elemental diffusion of Fe into Fe(Se, Te)2. Due to the effective shortened length of diffusion paths, the superconducting phase formation temperature was ∼100 °C lower during our HEBM aided sintering method than that in the traditional solid state sintering method. Finally, a critical temperature of 14.2 K was observed in the final treatment sample, which was sintered for 12 h at 700 °C with a slow cooling rate followed by an annealing process under oxygen atmosphere for 24 h. This Tc value could demonstrate a good superconducting phase obtained by the HEBM aided sintering method.

Tellurium Distribution and Speciation in Contaminated Soils from Abandoned Mine Tailings: Comparison with Selenium.

The distribution and chemical species of tellurium (Te) in contaminated soil were determined by a combination of microfocused X-ray fluorescence (μ-XRF), X-ray diffraction (μ-XRD), and X-ray absorption fine structure (μ-XAFS) techniques. Results showed that Te was present as a mixture of Te(VI) and Te(IV) species, while selenium (Se) was predominantly present in the form of Se(IV) in the soil contaminated by abandoned mine tailings. In the contaminated soil, Fe(III) hydroxides were the host phases for Se(IV), Te(IV), and Te(VI), but Te(IV) could be also retained by illite. The difference in speciation and solubility of Se and Te in soil can result from different structures of surface complexes for Se and Te onto Fe(III) hydroxides. Furthermore, our results suggest that the retention of Te(IV) in soil could be relatively weaker than that of Te(VI) due to structural incorporation of Te(VI) into Fe(III) hydroxides. These findings are of geochemical and environmental significance for better understanding the solubility, mobility, and bioavailability of Te in the surface environment. To the best of our knowledge, this is the first study reporting the speciation and host phases of Te in field soil by the μ-XRF-XRD-XAFS techniques.

Combined effects of dietary malic acid andBacillus subtilison growth, gut microbiota and blood parameters of Nile tilapia (Oreochromis niloticus)

The study investigated effect of dietary supplementation with malic acid, Bacillus subtilis and a mixture of the two (3 × 2 factorial trial) on Nile tilapia (Oreochromis niloticus) health. Treatment groups (T1–T6) were fed diets containing three levels of malic acid (0.0, 5.0 and 10.0 g/kg), each of which was supplemented with 0 and 1.1 × 105 cfu/g B. subtilis, respectively. Each treatment group was assigned randomly to triplicate groups of 35 fish (5.26 ± 0.06 g) in 18 tanks for 84 days. The results indicated that survival was higher in all dietary treatments as compared to the control fed fish. The highest values of FBW, WG and SGR (%), PER, PPV and ER were recorded in groups T4 and T6, which were fed diets supplemented with 5 g malic acid/kg and 1.1 × 105 cfu/g B. subtilis and 10 g malic acid/kg and 1.1 × 105 cfu/g B. subtilis, respectively. The best value of FCR was obtained in groups T4 and T6. The lowest total bacterial count in the gut and faeces was detected in fish from group T6. The values of haematocrit, haemoglobin, red blood cells, white blood cells, total protein, albumin and globulin were significantly higher (p < .05) in fish from groups T4 and T6 (diets supplemented with malic acid and B. subtilis). As compared to the control fed fish, te mixture of these substances are promising as immune enhancher in aquacultured fish.

ChemInform Abstract: Concerted Rattling in CsAg5Te3 Leading to Ultralow Thermal Conductivity and High Thermoelectric Performance.

AbstractPure samples of the title p‐type material are obtained from stoichiometric mixtures of Ag, Te, and Cs2Te3 (silica tubes, 1073 K, 2 h).

ChemInform Abstract: Synthesis and Characterization of Kesterite Cu2ZnSnTe4 via Ball‐Milling of Elemental Powder Precursors.

AbstractThe title compound is synthesized by ball‐milling of powder mixtures of Cu, Zn, Sn, and Te (planetary ball mill, 450 rpm, 30 h).

Active Mg Estimation Using Thermal Analysis: A Rapid Method to Control Nodularity in Ductile Cast Iron Production

Appropriate nodularity in ductile iron castings is strongly associated with the presence of high enough not combined Mg dissolved in the melt to cast. However, the residual Mg which is commonly measured for production control accounts for both dissolved Mg and Mg combined as oxides and sulfides. To account for the uncertainties associated with such a control, it is quite usual to over treat the melt with the risk of porosity appearance. A new methodology based on thermal analysis has been developed in the present work so as to estimate the amount of free Mg dissolved in the melt ready for pouring. A combination of Te mixture and a new “reactive mixture” composed of sulfur plus a commercial inoculant has been prepared for this purpose. This reactive mixture is able to transform the magnesium remaining dissolved in the melt to combined forms of this element. Experiments performed both during start of production (when Mg overtreatment is usual) and during normal mass production indicate that important variations of free Mg occur without relevant changes in residual Mg content as determined by spectrometry. The method developed in the present work has shown to be highly effective to detect those melt batches where active Mg content is not high enough for guaranteeing a correct nodularity of castings. Selection of proper active Mg thresholds and a correct inoculation process are critical to avoid “false”-negative results when using this new method.

Observation of an intermediate phase in tungsten doped Sb2Te phase change thin films by temperature dependent measurements of structural, optical, and electronic properties

The optical properties, electronic structure, and microstructure of Sb2Te (ST) phase change films as functions of temperature and tungsten (W) concentration have been investigated by means of temperature dependent x-ray diffraction (XRD), Raman scattering, and spectroscopic ellipsometry. Based on the variations of the diffraction peaks, phonon modes, and dielectric functions during the temperature elevation process, the intermediate (INT) crystalline state of W doped Sb2Te (WST) films between amorphous (AM) and hexagonal (HEX) phases can be readily proposed, which is a mixture of crystalline Sb and Te. The anomalous behaviors of dielectric functions and partial spectral weight integral for crystalline films elucidate the existence of INT state. Furthermore, the good agreement between experimental and calculated dielectric functions reveals that the first-principles calculation method can be used to make qualitative analysis in the materials with similar multilayered structures.

Structural investigations and phase identification in (Cd, Cr)Te alloys

Polycrystalline (Cd,Cr)Te ingots with 2.5, 5, and 25 at.% of nominal chromium content were prepared by alloying the mixture of elemental Cd, Te, and Cr2Te3 salt. The alloys were studied by means of scanning electron microscopy, X-ray diffraction, and energy dispersive X-ray spectroscopy methods in order to determine their crystallinity and phase composition. It was found that the ingots of the lowest doped material are composed of continuous CdTe:Cr host matrix with embedded Cr-related second-phase particles. With the exception of zinc-blende type Cd1−x Cr x Te, the grains of Cr–Te intermetallic compounds with μm-sized particles of pure Cr are solidified from the higher-doped melt. The mechanism of their formation was examined on the basis of the phase diagram for the Cr–Te system. Chromium solubility limit in the cadmium telluride lattice was estimated to be about 1.5 at.%.

Formation Phases and Electrical Properties of Ge-Bi-Te Compounds with Homologous Structures

We prepared polycrystalline samples of GeBi6−xInxTe10 (x = 0, 0.06, 0.18, 0.3, and 0.6) by melting a stoichiometric mixture of Ge, Bi, In, and Te, followed by quenching in water and annealing at 723 K for 1 week. Under these preparation conditions and irrespective of the degree of In-substitution, the samples contained two different periodic structures: GeBi6Te10 and GeBi4Te7 structures. The relationship between the Seebeck coefficient, electrical resistivity, and phase fraction of the two structures was investigated at room temperature. We concluded that changes in the transport properties for all samples may reflect a mixture effect of the phase fraction of the two structures and the amounts of In-substitution in the framework of the assumed structure model in this study. The thermoelectric properties of the samples with x = 0 and 0.18 were determined from 300 K to 723 K from the measured electrical properties and the reported lattice thermal conductivity. The sample with x = 0.18 had the highest dimensionless figure of merit: ZTmax = 0.11 at 466 K, which was 1.8 times larger than that of the sample with x = 0.

ChemInform Abstract: Synthesis, Characterization and Thermoelectric Properties of the Oxytelluride Bi2O2Te.

AbstractBi2O2Te is prepared by solid state reaction of a stoichiometric mixture of Bi, Bi2O3, and Te (evacuated silica tubes, 873 K, 10 h; complex heating schedule).

Synthesis, characterisation and thermoelectric properties of the oxytelluride Bi2O2Te

Bi2O2Te was synthesised from a stoichiometric mixture of Bi, Bi2O3 and Te by a solid state reaction. Analysis of powder X-ray diffraction data indicates that this material crystallises in the anti-ThCr2Si2 structure type (space group I4/mmm), with lattice parameters a=3.98025(4) and c=12.70391(16)Å. The electrical and thermal transport properties of Bi2O2Te were investigated as a function of temperature over the temperature range 300≤T (K)≤665. These measurements indicate that Bi2O2Te is an n-type semiconductor, with a band gap of 0.23eV. The thermal conductivity of Bi2O2Te is remarkably low for a crystalline material, with a value of only 0.91Wm−1K−1 at room temperature.