Miracle-dz/UniFAR-FTUs huggingface dataset:
Comparison of digestion methods for total elemental analysis of peat and separation of its organic and inorganic components

In order to find the most efficient digestion method for the total elemental recovery in peat, ten samples were subjected to different techniques and analysed for Ca, Mg, Fe, Al, Na, K, Mn, P, Zn, Cu, Li, Cd, Co, Ni, Pb and Si using atomic-absorption spectrophotometry. The most satisfactory procedures were dry ashing followed by hydrofluoric acid treatment and wet digestion using a mixture of hot nitric, perchloric and hydrofluoric acids. The wet digestion offers the advantage of a single decomposition method for the determination of Ca, Mg, Fe, Al, K, Na, Mn, Cu, Li, Zn and P. An alkaline fusion technique was required for the determination of Si. Hydrogen peroxide was used to separate the peat into its organic and inorganic components, leading to the total recovery of the elements for both fractions.
Prediction of the critical reduced electric field strength for carbon dioxide and its mixtures with 50% O2 and 50% H2 from Boltzmann analysis for gas temperatures up to 3500 K at atmospheric pressure

This paper provides theoretical calculations that predict the dielectric breakdown properties of carbon dioxide (CO2) and its mixtures with 50% O2 and 50% H2 for a gas temperature range of 300–3500 K at 0.1 MPa. CO2 is one of the most likely candidates for an environment-friendly arc-quenching medium to replace SF6 in high-voltage circuit breakers. Initially, the electron energy distribution function (EEDF) is derived by solving the Boltzmann equation under the zero-dimensional two-term spherical harmonic approximation. Then the reduced ionization and attachment coefficients are obtained, based on the calculated EEDF. Finally, the critical reduced electric field strength (E/N)cr, which is defined as the value for which total ionization reactions are equal to total attachment reactions, is obtained and analysed. The results demonstrate the superior breakdown properties of a 50% CO2–50% O2 mixture to those of both pure CO2 and 50% CO2–50% H2. Nearly no deviation in (E/N)cr is found in a 50% CO2–50% O2 mixture for gas temperatures up to 2500 K, and although there is clear reduction as the gas temperature is increased further to 3500 K, the value remains higher than that of pure CO2.
Thermodynamics of binary solutions. Part 2.—Vapour pressures and excess free energies of aniline solutions

Using a Swietoslawski ebulliometer, isothermal vapour pressures have been determined for the solutions of aniline in benzene, carbon tetrachloride and chlorobenzene in the temperature range 25–50°C. The activity coefficients and the excess free energies of these systems are evaluated at 25, 35 and 45°C over the entire range of concentrations. The results when compared with Balescu's theory show a reasonable agreement for the systems aniline + benzene and aniline + carbon tetrachloride, while the system aniline + chlorobenzene shows considerable deviations.
Crystal structure of phosphonium carboxylate complexes. The role of the metal coordination geometry, ligand conformation and hydrogen bonding

A series of new mononuclear and heteronuclear complexes of carboxylate phosphonium betaines with biologically important metals (Zn(II), Cd(II), Hg(II) and Cu(II)) were obtained in aqueous media at ambient temperature. X-ray single crystal diffraction showed that carboxylate phosphonium betaines exhibit versatile complexation abilities, producing monomeric, dimeric and tetrameric homonuclear and mixed metal complexes. The binding mode was found to change in the series of Zn(II), Cd(II) and Hg(II) complexes with an increase of the cation radius. Water and chlorine atoms, bound to the metal, play an important role in crystal formation. In the case of α- and β-substituted phosphabetaines, the crystallization of various stereoisomers was observed including a rare case of co-crystallization of two diastereomers in one crystal.
Application of multivariate data analysis techniques in modeling structure-property relationships of some superconductive cuprates

Abstract Multivariate analysis methods are used for the examination of the fine structure and superconductivity properties of the 1212-type superconductive copper oxides with the stoichiometry of MA 2 Q Cu 2 O 6+ z ( M =Cu, Hg, Tl/Pb; A =Ba, Sr; Q =rare-earth element, Ca; z =0–1). PCA (principal component analysis) is used for the qualitative evaluation of relations between structural variables such as the cation–oxygen bond lengths, bond angles, and oxygen content z , and the superconductivity transition temperature T C , adopted from a number of neutron diffraction studies published for MA 2 Q Cu 2 O 6+ z samples with various compositions. The different ways of doping positive holes in the superconductive CuO 2 plane are discussed on the basis of the PCA results. Quantitative modeling of the value of T C in the Cu A 2 Q Cu 2 O 6+ z system is successfully performed by PLS (projections to latent structures by means of partial least squares), resulting in a model with predictive power of ∼93%. The present study demonstrates the potential of multivariate analysis methods in studying structure–property relations of inorganic materials with ionic structure.
Preparation of mutton sausages.

Sausages were prepared from emulsions containing various proportions of mutton and fillers such as carrots, onions, green curry stuff and spices. The total cooking loss of sausages cooked in water at 80 degree C for 20 min increased as the proportion of meat in the sausage emulsion increased from 30 to 36% or the ratio of meat to added fat increased from 2.0 to 8.3. Addition of 3% dried bread decreased these losses. Cooking in dry heat resulted in more flavourful sausages than those cooked in water. Total cooking losses were greatest for dry cooked sausages, but the loss was mainly confined to water lost by evaporation; during cooking in water, losses consisted of soluble ingredients. The optimum level of lean mutton, composited from a whole carcass, for good firmness and texture after cooking the sausages was 43-45%. [See also FSTA (1971) 3 3S273. ]
In vivo non-invasive multiphoton tomography of human skin

High resolution non-invasive 3D imaging devices are required to detect pathogenic microorganisms such as Anthrax spores, bacteria, viruses, fungi and chemical agents entering biological tissues such as the epidermis. Due to the low light penetration depth and the biodamage potential, ultraviolet light sources can not be employed to realize intratissue imaging of bio- and chemohazards. We report on the novel near infrared laser technology multiphoton tomography and the high resolution 4D imaging tool DermaInspect for non-invasive detection of intratissue agents and their influence on cellular metabolism based on multiphoton autofluorescence imaging (MAI) and second harmonic generation (SHG). Femtosecond laser pulses in the spectral range of 750 nm to 850 nm have been used to image in vivo human skin with subcellular spatial and picosecond temporal resolution. The non-linear induced autofluorescence of both, skin tissues and microorganisms, originates mainly from naturally endogenous fluorophores/protein structures like NAD(P)H, flavins, keratin, collagen, elastin, porphyrins and melanin. Bacteria emit in the blue/green spectral range due to NAD(P)H and flavoproteins and, in certain cases, in the red spectral range due to the biosynthesis of Zn-porphyrins, coproporphyrin and protoporphyrin. Collagen and exogenous non-centrosymmetric molecules can be detected by SHG signals. The system DermaInspect consists of a wavelength-tunable compact 80/90 MHz Ti:sapphire laser, a scan module with galvo scan mirrors, piezo-driven objective, fast photon detector and time-resolved single photon counting unit. It can be used to perform optical sectioning and 3D autofluorescence lifetime imaging (τ-mapping) with 1 μm spatial resolution and 270 ps temporal resolution. The parameter fluorescence lifetime depends on the type of fluorophore and its microenvironment and can be used to distinguish bio- and chemohazards from cellular background and to gain information for pathogen identification. The novel in vivo non-invasive imaging system offers the possibility to detect and to localize CB agents in tissues and to gain information on their impact on respiratory chain activity, cell division and metabolism. The system DermaInspect can also be used to detect food and water contamination.
Kinetics of the decolourization of a dyehouse effluent by Providencia rettgeri ODO

The potential of an organism isolated from a mixture of azo dyes to decolourize textile wastewater was investigated. The organism identified by 16S rDNA as a strain of Providencia rettgeri was able to remove 94 ± 0.56% of the colour in a dyehouse effluent within 24 h in batch experiments. P. rettgeri strain ODO was able to use the effluent as sole carbon and nitrogen source. The optimum pH and temperature for colour removal ranged between 7–8 and 30–35 °C, respectively. Analysis of the data showed that the decolourization process exhibited first order kinetics with respect to the colour intensity and biomass concentration. The rate constant k = 5.6 × 10−3 L/gDCMh at 37 °C. The specific growth rate, μ, of the organism was 0.013 h−1 while the mean doubling time was 52.9 h. The results indicated that P. rettgeri strain ODO has the potential for colour removal from textile effluent.
Smooth and self-similar SiO2-like films on polymers synthesized in roll-to-roll atmospheric pressure-PECVD for gas diffusion barrier applications

SiO2-like layers deposited by means of the developed atmospheric pressure glow-like DBD assisted CVD technology exhibit remarkable film properties, reported for the first time. The films synthesized in a roll-to-roll mode on polymeric webs, are as smooth as the substrate, irrespectively of the precursors (TEOS or HMDSO) and reactive gases (N2 or air) employed. Detailed AFM investigation on film morphology, surface roughness and auto correlation length (ξ) show that they are negligibly influenced with thickness and are similar to that of the polymeric substrate, indicating the self-similar growth of the SiO2-like layers in AP-PECVD. The films are uniform with no defects or particle being incorporated during the deposition process. The produced single layers on polymeric substrate show excellent gas barrier performances towards O2 and H2O permeation (OTR: <5 × 10−3 cm3·m−2·day−1 and WVTR: <5 × 10−3 g·m−2·day−1).
Theoretical design study on multifunctional triphenyl amino‐based derivatives for OLEDs

The use of triphenyl amino-based derivatives in organic light-emitting diodes (OLEDs) can significantly improve their efficiency and stability and especially their electroluminescence characteristics – most of the new hole-transport materials have this feature. In this study, a series of triphenyl amino-based compounds were computed, including two newly designed molecules. They can function as charge transport materials and emitters with high efficiency and stability. To reveal the relationship between the properties and structures of these bifunctional and multifunctional electroluminescent materials, the ground and excited state geometries were optimized at the B3LYP/6-31G(d), HF/6-31G(d), TD-B3LYP/6-31G(d), and CIS/6-31G(d) levels, respectively. The ionization potentials (IPs) and electron affinities (EAs) were computed. The lowest excitation energies, the maximum absorption, and emission wavelengths of these compounds were calculated by employing the time-dependent density functional theory (TD-DFT) method. Also, the mobilities of holes and electrons were studied computationally based on the Marcus electron transfer theory. The CH2Cl2 solvent effect on the absorption spectra of N,N′-di-1-naphthyl-N,N′-diphenylbenzidine (NPB) was considered by polarizable continuum model (PCM). The results obtained for these compounds are in good agreement with the experimental values. These data show that the proposed compounds 1 and 2 (N,B-di-1-naphthyl-N,B-diphenylbenzidine and Mes2N[p-4,4′-biphenyl-NPh(1-naphthyl)]), are multifunctional and bifunctional materials similar to Mes2B[p-4,4′-biphenyl-NPh(1-naphthyl)] (BNPB) and NPB, respectively. Copyright © 2009 John Wiley & Sons, Ltd.
Microbial and oxidative effects in degradation of polyethene

Biodegradative conversion of 14C present in high-density (linear) polyethene (HDPE) film to respiratory 14CO2 during a two-year aerated cultivation with soil or with Fusarium redolens dropped from 0.36% by weight to less than 0.16% by weight when the HDPE film was deprived from most of its low molecular components by extraction with cyclohexane. Decrease of 14CO2 production after extraction could be observed in different abiotic aging cultures. This is direct evidence for a primary utilization of the short-chain oligomeric fraction of the main crystalline materials. The extractable oligomeric fraction of HDPE was analyzed by gel permeation chromatography (GPC), and Mn 1049, 1088, and 1297 were found in untreated, aged, and biodegraded materials, respectively, indicating that microbes can oxidize somewhat longer polyolefin chains than aboitic forces do during aging. The limited degradation of HDPE confined to extractable material is comparable to the degradation of straight-chain n-alkanes and presumably proceeds according to similar mechanism. Such material (n-alkanes) can exit in the interstitial spaces between the crystalline lamellae as fringed micelles which infiltrate these cavities as amorphous clusters but are also produced to some extent during aging and weathering. Protection of HDPE by antioxidant (a sterically hindered phenol) resulted in an inhibition of microbiological catabolism of 14C to 14CO2. Aging was also suppressed in this way, indicating that although remnants of the supported CrCO3 polymerization catalyst are responsible for a slight but cumulative abiotic oxidation of the unprotected polymer, this effect will be counteracted too by the antioxidative additive. As biological degradation is superimposed on the chemistry of aging, a mutual synergism between the two effects is feasible.
Thick UV-patternable hybrid sol-gel films prepared by spin coating

We report on the fabrication and characterization of thick UV-patternable hybrid sol-gel films by spin coating using a modified sol-gel process. Thick coatings of 25 microns with crack-free surfaces can be produced by one spin coating step. Characterization using different techniques including atomic force microscopy, scanning electron microscopy and profilometry show both a smooth surface of optical quality and precise patterning with sharp vertical walls. Refractive index measurements by prism coupling and using a spectroscopic ellipsometer indicate high reproducibility of coating optical properties prepared by this procedure. Large refractive differences can be obtained by varying the process conditions, allowing the preparation of channel waveguide structures.
Optical quantum confinement in low dimensional hematite

Hematite is considered to be a promising material for various applications, including for example photo-electrochemical cells for solar hydrogen production. Due to limitations in the charge transport properties hematite needs to be in the form of low-dimensional particles or thin films in several of these applications. This may however affect the optical properties, introducing additional complications for efficient design of photo-active devices. In this paper the optical absorption is analyzed in detail as a function of film thickness for 35 thin films of hematite ranging between 2 and 70 nm. Hematite was deposited by atomic layer deposition on FTO-substrates using Fe(CO)5 and O2 as precursors. It was found that for film thicknesses below 20 nm the optical properties are severely affected as a consequence of quantum confinement. One of the more marked effects is a blue shift of up to 0.3 eV for thinner films of both the indirect and direct transitions, as well as a 0.2 eV shift of the absorption maximum. The data show a difference in quantum confinement for the indirect and the direct transitions, where the probability for the indirect transition decreases markedly and essentially disappears for the thinnest films. Raman measurements showed no peak shift or change in relative intensity for vibrations for the thinnest films indicating that the decrease in indirect transition probability could not be assigned to depression of any specific phonon but instead seems to be a consequence of isotropic phonon confinement. The onset of the indirect transition is found at 1.75 eV for the thickest films and shifted to 2.0 eV for the thinner films. Two direct transitions are found at 2.15 eV and 2.45 eV, which are blue shifted 0.3 and 0.45 eV respectively, when decreasing the film thickness from 20 to 4 nm. Low dimensional hematite, with dimensions small enough for efficient charge transport, thus has a substantially lower absorption in the visible region than expected from bulk values. This knowledge of the intrinsic optical behavior of low dimensional hematite will be of importance in the design of efficient photo-active devices.
Measurement of Phosphorus in Soils by Near Infrared Reflectance Spectroscopy: Effect of Reference Method on Calibration

Abstract The use of ultraviolet (UV), visible (VIS), near infrared reflectance (NIR), and midinfrared (MIR) spectroscopy techniques have been found to be successful in determining the concentration of several chemical properties in soils. The aim of this study was to evaluate the effect of two reference methods, namely Bray and Resins, on the VIS and NIR calibrations to predict phosphorus in soil samples. Two hundred (n=200) soil samples were taken in different years from different locations across Uruguay with different physical and chemical characteristics due to different soil types and management. Soil samples were analyzed by two reference methods (Bray and Resins) and scanned using an NIR spectrophotometer (NIRSystems 6500). Partial least square (PLS) calibration models between reference data and NIR data were developed using cross‐validation. The coefficient of determination in calibration (R2) and the root mean square of the cross validation (RMSECV) were 0.58 (RMSECV: 3.78 mg kg−1) and 0.61 (RMSECV: 2.01 mg kg−1) for phosphorus (P) analyzed by Bray and Resins methods, respectively, using the VIS and NIR regions. The R2 and RMSECV for P using the NIR region were 0.50 (RMSECV: 3.78 mg kg−1) and 0.58 (RMSECV: 2.01 mg kg−1). This study suggested that differences in accuracy and prediction depend on the method of reference used to develop an NIR calibration for the measurement of P in soil.
Determination of atomic hydrogen density in non-thermal hydrogen plasmas via emission actinometry

Atomic hydrogen plays an important role in the chemical vapour deposition of diamond and other functional materials. This paper reports the experimental determinations of atomic hydrogen density in dielectric barrier discharge hydrogen plasmas via optical emission spectrometry using Ar as an actinometer. At certain discharge conditions (ac 24 kHz, 28 kV of peak-to-peak voltage), the approximate hydrogen dissociation fractions calculated from the emission intensities with respect to electron temperatures obtained with the Langmuir probe, are decreased from 0.099 to 0.01 as the gas pressure increases from 2 to 4 Torr. The relative H atom mole fractions as a function of discharge parameters (spatial position and gas flow rate) have been investigated. It is shown that the discharge characteristics strongly depend on the spatial position but not on the gas flow rate. The influences of the above operating parameters on the emission intensities have been discussed.
Cationized nylon as adsorbent for anionic residual dyes

For use as an ion exchanger, a cationized nylon (EPTMAC–nylon) was prepared by reacting nylon-6,6 with epoxy propyl trimethyl ammonium chloride (EPTMAC), using anhydrous tin chloride (SnCl2) as catalyst in a nonaqueous medium. Evidence of grafting was provided by atomic force microscopy and the exchange capacity of EPTMAC–nylon was evaluated by potentiometric titration. The adsorption of four dyes (Acid Blue 25, Acid Yellow 99, Reactive Yellow 23, and Acid Blue 74) from aqueous solutions using a batch process was studied according to the adsorption capacity of the cationized support. The effect of experimental parameters such as dye concentration and adsorption temperature were analyzed. The adsorption isotherms were determined at different temperatures and modeled using Langmuir, Freundlich, and Jossens equations. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 2513–2522, 2004
Modeling and Control of Gas Ebullition in Capped Sediments

A major concern in sediment capping effectiveness is gas ebullition from organic matter biodegradation in sediments. Gases may open advective channels that can result in substantial pollution release. The aim of this study was to determine the gas ebullition rate in sediments in preparation for construction of an active capping technology demonstration at the Collateral Channel site in the Chicago River. Sediment samples were collected from five sites along a transection of Collateral Channel from the combined sewer outfall at the Channel terminus. Biogenic gas production was measured in samples incubated at 5° to 35° C. Gas production followed a first order reaction trend and Arrhenius plots were obtained to determine the temperature dependence of the kinetic rate. These allowed us to predict gas ebullition for the annual temperature variation in the sediments. CO2/CH4 ratios change with temperature, with lower ratios at lower temperatures suggesting dominance by acetoclastic methanogens. These data were used to select adequate active capping remedial alternatives for the Channel. We conclude that wide variations in gas production occur, necessitating gas capture/control during the elevated temperatures of summer. To achieve this, an innovative geo-mesh material with an overlying highly permeable layer will be employed.
Industrial high‐rate (∼5 nm/s) deposited silicon nitride yielding high‐quality bulk and surface passivation under optimum anti‐reflection coating conditions

High‐quality surface and bulk passivation of crystalline silicon solar cells has been obtained under optimum anti‐reflection coating properties by silicon nitride (a‐SiNx:H) deposited at very high deposition rates of ∼5 nm/s. These a‐SiNx:H films were deposited using the expanding thermal plasma (ETP) technology under regular processing conditions in an inline industrial‐type reactor with a nominal throughput of 960 solar cells/hour. The low surface recombination velocities (50–70 cm/s) were obtained on p‐type silicon substrates (8·4 Ω cm resistivity) for as‐deposited and annealed films within the broad refractive index range of 1·9–2·4, which covers the optimum bulk passivation and anti‐reflection coating performance reached at a refractive index of ∼2·1. Copyright © 2005 John Wiley & Sons, Ltd.
Reactivity of HO2/O−2 Radicals in Aqueous Solution

Kinetic data for the superoxide radical (HO2⇄O−2 +H+, pK=4.8) in aqueous solution have been critically assessed. Rate constants for reactions of O−2 and HO2 with more than 300 organic and inorganic ions, molecules and other transient species have been tabulated.