Miracle-dz/UniFAR-FTUs huggingface dataset:
Defect induced optical bandgap narrowing in undoped SnO2 nanocrystals

Unusual optical bandgap narrowing is observed in undoped SnO2 nanoparticles synthesized by the solution combustion method. The estimated crystallite size is nearly 7 nm. Though the quantum confinement effect predicts a larger optical bandgap for materials with small crystallite size than the bulk, the optical bandgap in the as synthesized materials is found to be 2.9 eV compared to the reported value of 3.6 eV for bulk SnO2 particles. The yellow-green photoluminescence emissions and the observed narrowing of the bandgap can be attributed to the deep donor levels of oxygen vacancies, owing to the high exothermicity of the combustion reaction and the faster cooling rates involved in the process.
Dielectric constants of yttrium and rare‐earth garnets, the polarizability of gallium oxide, and the oxide additivity rule

The dielectric constants (kappa[script ']) and dielectric loss values of 10 rare-earth gallium garnets and 1 rare-earth aluminum garnet were measured at 1 MHz using a two-terminal method with empirically determined edge corrections. The results are: kappa[script '](Dy3Al5O12)=11.07±0.05; kappa[script '](Ho3Ga5O12) =12.38±0.05; kappa[script '](Dy3Ga5O12)=12.36±0.06; kappa[script '](Tb3Ga5O12) =12.40 ±0.03; kappa[script '](Gd3Ga5O12) =12.18±0.10; kappa[script '](Eu3Ga5O12) =12.46±0.05; kappa[script '](Sm3Ga5O12) =12.55±0.03; kappa[script '](Nd3Ga5O12) =12.59±0.12; kappa[script '](Y3Sc2Ga3O12) =12.94±0.03; kappa[script '](Sm3Sc2Ga3O12) =13.67±0.04; and kappa[script '](La2.66Lu2.66Ga2.66O12) =14.40±0.03. The dielectric polarizability of Ga2O3 derived from the dielectric constants of these and other Ga compounds is 8.80±0.14 A3. The agreement between measured dielectric polarizabilities as determined from the Clausius–Mosotti equation and those calculated from the sum of oxide polarizabilities according to alphaD(mineral) =SigmaalphaD (oxides) for six aluminum garnets and twelve gallium garnets is ~1%.
Effect of reciprocal pressurization on germination and killing of bacterial spores

We measured the germinating and inactivating effects of reciprocal pressurization (consisting of six cycles of 5 min compression and rapid decompression) (RP) on bacterial spores compared with the effects of continuous pressurization (CP) by using heat sensitivity (70 °C, 30 min) as a criterion for germination. There was no significant difference in the germination of spores by RP and CP, but there was a significant difference in spore inactivation by RP and CP except for 200 MPa-25 and 35 °C. The number of germinated spores was more than the number of inactivated spores following RP and CP. These results indicated that compression could initiate germination, whereas rapid decompression could not initiate germination, but could inactivate the germinated spores. Thus, RP was more effective than CP in inactivating spores.
Chemical Composition of the Essential Oils of Pistacia lentiscus L. from Algeria

Abstract The essential oils of Pistacia lentiscus L. from three regions of Algeria (Algiers, Tizi-Ouzou and Oran) were isolated from aerial parts by hydrodistillation and were investigated by GC and GC/MS. Longifolene was predominant in the oils from Algiers (12.8%) and Tizi-Ouzou (16.4%), while α-pinene (19.0%) was the major constituent of the Oran oil. The other compounds of oils were present in important amounts; Algiers oil: γ-cadinene (6.2%)s, trans-β-terpineol (5.0%) and α-acorneol (4.6%); Tizi-Ouzou oil: trans-β-terpineol (15.6%), terpinen-4-ol (7.0%) and γ-muurolene (5.7%); Oran oil: trans-β-terpineol (13.1%), sabinene (12.6%) and β-pinene (6.5%). A comparison with oils from P. lentiscus of other countries reported in literature shows both qualitative and quantitative differences.
Enantiospecific syntheses of pseudopterosin aglycones. Part 2. Synthesis of pseudopterosin K–L aglycone and pseudopterosin A–F aglycone via a B→BA→BAC annulation strategy

The enantiomeric aglycones of pseudopterosins K–L and A–F are synthesised from (−)- and (+)-isopulegol respectively. Key features are (a) the construction of the C3 stereogenic centre by a directed epoxidation–reduction sequence (K–L); (b) the creation of the C3 stereogenic centre by a Pfaltz asymmetric conjugate reduction (A–F); (c) benzannulation of a cyclic ketone starting with an α-oxoketene-S,S-acetal to give a tetrahydronaphthol ether; and (d) a diastereoselective intramolecular electrophilic aromatic substitution using an allylic sulfone as the electrophilic trigger to complete the hexahydro-1H-phenalene core. An X-ray structure of compound 50 was determined.
EVALUATION OF DI(2-ETHYLHEXYL)ISOBUTYRAMIDE (D2EHIBA) AS A PROCESS EXTRACTANT FOR THE RECOVERY OF 233U FROM IRRADIATED Th

ABSTRACT Extraction behaviour of U(VI) and Th(IV) has been studied employing 0.5 M D2EHIBA (di(2-ethylhexyl)isobutyramide) in n-dodecane as a function of nitric acid concentration. An improved separation of U from Th could be achieved in the presence of fluoride ion. Use of 1 M Al(NO3)3 in 2 M HNO3 has been suggested as the scrubbing solution. Various physico-chemical properties like density, viscosity, interfacial tension (IFT) and limiting organic concentration (LOC) of Th/U have been measured to evaluate the use of D2EHIBA as a process solvent. Degradation behaviour (acid hydrolysis as well as gamma radiolysis) of D2EHIBA under process conditions has been investigated using potentiometry as well as distribution studies.
Comparison of Basic Dye Crystal Violet Removal from Aqueous Solution by Low-Cost Biosorbents

Abstract The removal of basic dye crystal violet by low-cost biosorbents was investigated in this study using a batch experimental system. The adsorption of crystal violet onto various adsorbents was solution pH-dependent and the maximum removal occurred at basic pH 10.0. The kinetic experimental data were analyzed using pseudo-first-order and pseudo-second-order equations to examine the adsorption mechanism and the intraparticle diffusion model to identify the potential rate controlling step. These results suggested that the adsorption of crystal violet onto various adsorbents was best represented by the pseudo-second-order equation. The suitability of the Langmuir and Freundich adsorption isotherms to the equilibrium data was also investigated at various temperatures for all four sorbents and the adsorption isotherms exhibited Freundlich behavior. The Freundlich constant Kf was 1.55 for alligator weed, 2.33 for Laminaria japonica, 9.59 for rice bran and 5.38 (mg/g)/(mg/L)1/n for wheat bran, respectively at adsorbent concentration 5 g/L, pH 10.0 and 20°C. The thermodynamic parameters (ΔH, ΔG, and ΔS) were calculated and the results showed that the adsorption process for various adsorbents was spontaneous, endothermic, with an increased randomness, respectively. The particle size and the reaction temperature exhibited an insignificant impact on the adsorption equilibrium of crystal violet. The adsorbents investigated could serve as low-cost adsorbents for removing the crystal violet from aqueous solution.
EFFECTIVE COEFFICIENTS FOR TWO PHASE MAGNETO-ELECTROELASTIC FIBROUS COMPOSITE WITH SQUARE SYMMETRY CELL IN-PLANE MECHANICAL DISPLACEMENT AND OUT-OF-PLANE ELECTRIC AND MAGNETIC FIELD CASE

ABSTRACT The purpose of the present work is to determine the magneto-electroelastic effective properties of reinforced piezoelectric composite materials with unidirectional cylindrical fibers periodically distributed in a square array through the Asymptotic Homogenization Method (AHM). The case when mechanical displacement is in-plane and electric and magnetic fields are out-of-plane is studied. Each periodic cell of the medium is a binary composite wherein both constituents are homogeneous magneto-electroelastic materials with transversely isotropic properties. Closed-form expressions for the overall properties are obtained. Numerical calculations are carried out for the BaTiO3/CoFe2O4 composite. A good match is obtained between AHM and other calculations reported in the literature. These results may be considered as congruent with the experimental experience.
Preparation method for solid samples with low nitrogen content for spectrometric nitrogen-15 analysis

A new procedure for the conversion of bound nitrogen into nitrogen gas, applicable to solid material, is described. It embodies two main stages: the catalytic ammonification of the sample and the consecutive transformation of ammonium to molecular nitrogen by the modified Dumas method. The first step of the preparation is carried out in a quartz reactor, filled with granular nickel, at a temperature of 700 °C, the ammonia gas produced being trapped in sulphuric acid. In the second step, this solution is neutralised, dried and subjected to the Dumas combustion.The addition of reagents does not influence the results of the measurements. Spectrometric 15N percentage abundances are converted into mass spectrometric “true”15N percentage abundances by using two straight calibration lines, one over the lower range of abundances (0.36–2.4%15N) and the other over the range 2.4–11%15N. A relative error smaller than 2% for the recalculation of the standards substantiates the accuracy of the conversion.The method has been applied to the study of nutrient uptake by marine phytoplankton. The assimilation rate of the labelled compound was determined on samples of 2.5 mg of particulate matter with a maximum nitrogen content of 0.2 mg.
Conformational sampling with Poisson–Boltzmann forces and a stochastic dynamics/Monte Carlo method: Application to alanine dipeptide

We apply a combination of stochastic dynamics and Monte Carlo methods (MC/SD) to alanine dipeptide, with solvation forces derived from a Poisson–Boltzmann model supplemented with apolar terms. Our purpose is to study the effects of the model parameters, such as the friction constant and the size of the electrostatic finite difference grid, on the rate of conformational sampling and on the accuracy of the resulting free energy map. For dialanine, a converged Ramachandran map is produced in significantly less time than what is required by stochastic dynamics or Monte Carlo alone. MC/SD is also shown to be faster, per timestep, than explicit methods. © 1997 John Wiley & Sons, Inc. J Comput Chem 18: 1750–1759, 1997
Comprehensive Chemical and Isotopic Analyses of Basalt and Sediment Reference Materials

Geochemical studies of geological samples require the precise determination of their major and trace element contents and, when measured, of their isotopic compositions. It is now commonly accepted that the accuracy and precision of geochemical analyses are best estimated by the concomitant analysis of international reference materials run as unknown samples. Although the composition of a wide selection of basalts is relatively well constrained, this is far from being the case for sedimentary materials. We present here a comprehensive set of major and trace element data as well as Nd, Hf, Sr and Pb isotopic compositions for thirteen commonly used international reference materials – eight magmatic rocks (BHVO‐2, BR, BE‐N, BR 24, AGV‐1, BIR‐1, UB‐N, RGM‐1) and five sediments (JLk‐1, JSd‐1, JSd‐2, JSd‐3, LKSD‐1). We determined the concentrations of over forty elements in the magmatic rocks together with Sr, Nd, Hf and Pb isotopic compositions. Our trace element results were both accurate (difference ≤ 3%) and precise (reproducibility at 1s ≤ 3%) and the isotopic results were very similar to other published values. In contrast, we observed a significant chemical and isotopic variability in the sedimentary materials, which we attribute to mineral heterogeneities in the powders. Despite the limitation imposed by this heterogeneity, our work presents a complete set of data determined with a precision not yet achieved in the literature for sedimentary material. We also provide the first Nd, Hf and Pb isotopic measurements for the five sediments, which are commonly used by the geochemical community. Our study of both basalt and sediment reference materials represents a comprehensive and self‐consistent set of geochemical data and can therefore be considered as a reference database for the community.
Effect of repeated manure application on potassium, calcium and magnesium in soil and cereal crops in Saskatchewan

Increasing use of animal manures in Saskatchewan requires information on the effect of manure addition on the availability of soil K, Ca and Mg and their concentrations in plant tissue. To address these issues, we examined the effects of repeated application of liquid swine and solid cattle manure at low and high rates on extractable K, Ca and Mg in soils from three different long-term field trials in Saskatchewan, and on plant K, Ca and Mg concentrations in cereal straw grown on the soils. After 5 to 7 yr of manure application, extractable potassium in the soils was significantly increased, while extractable Ca and Mg tended to remain similar, or was decreased with swine manure addition. In the cereal straw, concentrations of K, Ca, and Mg were all increased by repeated swine manure application, such that there was no significant increase in the K/(Ca + Mg) ratio. However, the K/(Ca + Mg) ratio in the cereal straw grown on soil amended with the high rate of cattle manure was increased. These findings sug.
INTERMOLECULAR PROTON TRANSFER PROCESS IN SULFUR TAUTOMERIC HETEROCYCLES. I. A QUANTUM CHEMICAL APPROACH

Abstract Molecular structures of two tautomeric aromatic heterocycles, 2-mercaptobenzoxazole and 2-mercaptobenzothiazole, were analyzed from a quantum chemical approach by means of AM1 semiempirical molecular orbital calculations. Thiones are the preferential tautomeric structures of these compounds in solid phase and solutions, and the AM1 profiles of potential wells agree the experimental evidences. In spite of the good description of the thione and thiol structures by the AM1 approach, the experimental tautomerism observed at room temperature can not be explained by means of an intramolecular protonic transfer mechanism. The potential barrier AM1 calculations of both tautomers range from 40 to 50 kcal/mol, approximately. Therefore, we have postulated a tautomeric process through a geometrical model of co-planar dimers in these heterocyclic compounds. These dimers are more stable than the respective monomers and this model permit to assume a simultaneous intermolecular proton transfer process between su.
Growth and stress evolution of hafnium nitride films sputtered from a compound target

Hafnium nitride films were deposited on silicon substrates by direct sputtering a compound target in an Ar atmosphere using a radio-frequency magnetron sputtering system. X-ray diffraction, x-ray photoemission spectrum, and Rutherford backscattering spectrometry revealed the successful formation of cubic stoichiometric HfN films in a wide deposition condition range. The residual stress in stoichiometric HfN films is compressive, and depends strongly on Ar pressure and sputtering power. Unlike element metal deposition, a transition point of Ar pressure at which residual stress experiences from compressive to tensile state has not been found in stoichiometic HfN films. Although an increase in Ar pressure could lower the stress value, nitrogen enrichment was found at 2.0 Pa and much oxygen was incorporated in the film deposited at 3.0 Pa and above, which can lead to a dramatic increase in film resistivity. Shallow recoil implantation of HfN species receiving energy from fast Ar species reflected at the targe.
Ethyl 5‐(ethoxycarbonyl)‐3‐phenyl‐1H‐pyrazole‐1‐acetate

In the title compound, C16H18N2O4, all bond lengths and angles show normal values. The dihedral angle between the pyrazole ring and the benzene ring is 10.64 (9)°. The mol­ecules are linked into a parallel network by inter­molecular C—H⋯π inter­actions.
Arc attachment and fall voltage on the cathode of an ac high-pressure mercury discharge

By observation of arc attachment on the cathode of an ac high-pressure mercury discharge, a transition from a diffuse mode at low current to a spot mode at higher current was found. The transition was accompanied with a sudden decrease in the arc voltage of about 10 V. At decreasing current there is a reverse transition with a voltage increase. A recent cathode-fall model shows quite a similar behaviour. Further, the electrode sheath voltage (essentially the sum of anode and cathode fall) was measured and compared with the calculated cathode fall. The obvious differences especially during the current rise were ascribed to the anode fall which should attain highly negative values in the order of 10 V.
Biodegradation of tylosin residue in pharmaceutical solid waste by a novel Citrobacter amalonaticus strain

A large amount of pharmaceutical solid waste (PSW) has been generated in the process of tylosin production using fermentation. This PSW cannot been reused directly because of the existence of residual tylosin. The objective of this study was to investigate the method for biodegradation of tylosin antibiotic in PSW. The results showed that a novel tylosin‐degrading strain was isolated from the soil deposited by PSW and identified as Citrobacter amalonaticus. This strain was capable of degrading almost 100% of tylosin in PSW medium with an initial concentration of 50 mg/L after 72 h of incubation under conditions of the initial pH 6.0 and 30°C. The degradation kinetics for tylosin followed a first‐order model, and half‐lives were 16.16–16.82 h when the initial concentrations of tylosin ranged from 25 to 100 mg/L. These results indicate that the isolated strain has a relatively high ability to degrade tylosin and may be used for bioremediation of the environment contaminated by tylosin waste. © 2014 American Institute of Chemical Engineers Environ Prog, 34: 99–104, 2015
Proton transport properties at the grain boundary of barium zirconate based proton conductors for intermediate temperature operating SOFC

Proton transport properties across the grain boundary of barium zirconate based proton conductors were studied in accordance with the space charge concept. The analysis is performed at temperatures lower than 200 °C using a Mott-Schottky model. The barrier height of Y- and Gd-doped barium zirconate is in the range of 0.29 to 0.57 V, which higher than that of oxygen ionic conductors. The barrier height of the space charge layer shows a dependence on the dopant type and concentration. The dependence correlates with the enrichment of the dopant at the grain boundary. The results suggest that the enrichment of the dopant decreases the barrier height and is effective to improve proton transport properties across the grain boundary.
Recent Developments in Ion Mobility Spectrometry

Abstract The general principles and technical implementations of traditional time-of-flight ion mobility spectrometers and analyzers with field-dependent mobilities were reviewed in our last article in this journal. Recent advances in instrumentation and new applications since 2006 are highlighted in this review. In addition to traditional applications as military chemical-agent detectors, ion mobility techniques have become popular for different purposes. Though ion mobility spectrometry was solely used as vapor sensor in the past decades, further developments in ionization techniques (especially electrospray ionization) now permit its routine use for the analysis of liquid samples. The coupling of ion mobility spectrometry with selective sample preparation techniques such as molecular-imprinted polymers, coupling with chromatographic techniques, the use of dopants, and application of selective ionization sources has led to an expanded number of applications in industrial and environmental analysis with complex sample matrices due to an improved selectivity in comparison with traditional stand-alone spectrometers. Furthermore, new developments in hyphenated techniques, especially ion mobility–mass spectrometry couplings, has resulted in an increased number of new applications for the analysis of biomolecules and pharmaceutical samples and in clinical diagnostics.
Mode of action of fixed oils against eggs of Callosobruchus maculatus (F.).

Studies on the mode of action of fixed vegetable oils on Callosobruchus maculatus eggs revealed two possible mechanisms of action which may be complementary: (1) that the oils exert lethal action slowly by drastically reducing respiratory activity and elimination of toxic metabolites as a result of the oil ‘barrier effect’, and (2) direct toxic effects of oil or oil constituents that possibly penetrate the eggs. The slow lethal action of oil was demonstrated by the continuous low level respiratory activity (measured by carbon dioxide emission) of dying eggs over a six-day monitoring period, and the fact that a significantly higher proportion of the dead eggs found on groundnut or traditional coconut oiltreated grains developed up to the late embryonic stage (first instar larvae) when compared with the control. Furthermore, in an experiment carried out by trapping C. maculatus eggs on oil-treated and untreated artificial membrane (Sellotape), it was found that oiling did not affect egg development up to the late embryonic stage but prevented hatching of significantly higher numbers of developed first instar larvae. Eggs that successfully hatch on oily grain surfaces may find it more difficult to penetrate, since egg attachments on such surfaces were found to be significantly less secure than on the control. The proposed modes of action show that the complete spread of an oil film over the surfaces of a commodity is vital for the successful utilisation of fixed oils as stored-product protectants.
Epitaxially overgrown, stable W-GaAs Schottky contacts with sizes down to 50 nm

A processing scheme for the fabrication of embedded W-GaAs contacts has been established and the resulting contact characteristics have been evaluated. The main advantage of these contacts is that they are stable during high-temperature epitaxial overgrowth. The fabrication scheme is based on a liftoff process with electron beam evaporation of tungsten and subsequent epitaxial overgrowth using metalorganic vapor phase epitaxy. Various methods were used to characterize the buried contacts. First, the structural properties of GaAs surrounding embedded W features, with widths down to 50 nm, were characterized by high-resolution transmission electron microscopy. Measurements of the conductivity in individual, buried wires were performed in order to study the influence of the overgrowth process on the properties of the tungsten. We also evaluated the current-voltage characteristics for macroscopic contacts, which revealed a clear dependence on processing parameters. Optimized processing conditions could thus be established under which limited contact degradation occurred during overgrowth. Finally, we used the overgrowth technique to perform a detailed investigation of the electrical and optical properties of floating-potential embedded nano-Schottky contacts by space-charge spectroscopy.