Miracle-dz/UniFAR-FTUs huggingface dataset:
Study of the oxygen effect on mechanical pulp lignin using an improved lignin isolation method

Abstract Lignins from kraft and mechanical pulps were isolated before and after oxygen treatment with conventional methods (acidolysis and enzymatic isolation) and with a novel two-step method combining an enzymatic treatment and acidolysis. Results showed that the combined enzymatic hydrolysis-acidolysis made it possible to extract lignin from pulp with a better yield than acidolysis alone and with a higher degree of purity than after enzymatic hydrolysis alone. The lignin samples isolated with the two-step method were analysed by 13C NMR, 19F NMR and by gel permeation chromatography. It was shown that the behaviour of mechanical pulp lignin during oxygen treatment was different from that of kraft pulp lignin. Most of these differences could be explained by the lower phenolic content and larger molecular size of the mechanical pulp lignin. As a consequence, oxygen had a poor delignifying effect. Finally, 19F NMR spectroscopy showed that oxygen could destroy some quinones induced by the alkaline conditions of the O stage.
Theory of ion solvation dynamics in mixed dipolar solvents

Time dependent density functional theory in its “extended linear” or “surrogate” form is used to investigate the dynamics of selective ion solvation in binary dipolar solvents. It is shown that simple analytical approximations that trap the basic physics of the solvation process can be obtained. In particular, it is found that the relaxation of the solvent number densities about a charged solute is governed by two distinct modes clearly associated with electrostriction and redistribution processes. This is consistent with the physical picture suggested by molecular dynamics (MD) simulations. The solvent polarization relaxation is also dominated by two modes associated with the two rotational diffusion constants of the binary solvent. In addition to the analytical approximations, full numerical solutions of the extended linear theory are obtained and the dependence of the relaxation on solvent density and solute charge is discussed. Detailed comparisons of the theory with MD simulations for a closely related model indicate that the theory is qualitatively correct, but quantitatively poor generally predicting relaxation rates which are too fast. This is due mainly to the neglect of inertial or non-Markovian effects in the theoretical approach.Time dependent density functional theory in its “extended linear” or “surrogate” form is used to investigate the dynamics of selective ion solvation in binary dipolar solvents. It is shown that simple analytical approximations that trap the basic physics of the solvation process can be obtained. In particular, it is found that the relaxation of the solvent number densities about a charged solute is governed by two distinct modes clearly associated with electrostriction and redistribution processes. This is consistent with the physical picture suggested by molecular dynamics (MD) simulations. The solvent polarization relaxation is also dominated by two modes associated with the two rotational diffusion constants of the binary solvent. In addition to the analytical approximations, full numerical solutions of the extended linear theory are obtained and the dependence of the relaxation on solvent density and solute charge is discussed. Detailed comparisons of the theory with MD simulations for a closely relat.
Airborne Polycyclic Aromatic Hydrocarbons in Suspended Particulates from the Urban Atmosphere of Rijeka, Croatia

Besides earlier occasional campaigns, the systematic measurements of polynuclear aromatic hydrocarbons (PAHs) in total suspended particulates (TSP) started only in 2001, while in 2006 the analyses were switched to PAHs in PM10. The annual concentrations of PAHs are following the general declining trend with other combustion pollutants as SO2. Although PM10 formed approximately 44% of TSP for the 2006 year and multi-year periods (2001–2005 and 2007–2010), the fraction of PAHs in PM10 /TSP ratio was in the range between 17% for Phe to 80% to BbF + BkF (66% for BaP). The winter to summer ratio (W/S) of individual PAH concentration is almost doubled in TSP (range: 5.2 for Phe to 21.2 for BaP) relative to PM10 (range: 2.7 for Phe to 13.5 for BaP). PAHs profiles indicate diesel vehicles as principal sources of PAHs, with the occasional contribution of metal smelters and wood combustion in winter.
Analyses of Passiflora Compounds by Chromatographic and Electrophoretic Techniques

Passiflora is one of the 27 genera of the Passifloraceae family. Some Passiflora species are known by their edible fruits, which have a distinct flavor and aroma that favor their in natura consumption and their applicability in the food industry. Also, Passiflora leaves have therapeutical properties, such as the widely known anxiolytic and sedative effects. The quality control and the assessment of the compounds responsible for the Passiflora properties can be done by several chromatographic and electrophoretic techniques, such as planar chromatography (TLC and HTPLC), liquid chromatography (HPLC and UHPLC), gas chromatography (GC), and capillary electrophoresis (CE). The aim of this article is to review the analytical techniques used for the evaluation of the different compounds present in each part of a Passiflora plant, exploring the leaves, the fruits with their rinds and seeds, and other Passiflora parts, such as nectar and callus culture compositions, as well as to compare stability tests on several Passiflora products.
Die Struktur von Cimetidin (N″-Cyan-N-Methyl-N′-[2-[(5-methyl-1H-imidazol-4-yl)methylthio]ethyl]guanidin), einem Histamin H2-Rezeptor-Antagonist

Cimetidin Kristallisiert monoklin (Raumgruppe P21/c). Seine Struktur wurde rontgenographisch bestimmt und bis R = 0.035 verfeinert. Im Einzelmolekul entsteht durch eine intramolekulare N…HN-Wasserstoffbruckenbindung zwischen Imidazolring und Guanidingruppe ein stabiler zehngliedriger Ring. Intermolekulare Wasserstoffbruckenbindungen, die von der Cyanguanidingruppe ausgehen, verbinden zwei Nachbarmolekule paarweise in einer Kopf-Schwanz-Anordnung zu einem Zwolfring. Diese Molekulpaare verknupfen sich uber Wasserstoffbrucken zwischen Imidazolring und Cyangruppe zu gewellten Schichten. The Structure of Cimetidine (N′-Cyano-N-methyl-N′-[2-[(5-methyl-1H-imidazol-4-yl)-methylthio]ethyl]guanidine), a Histamine H2-Receptor Antagonist Cimetidine forms monoclinic crystals (space group P21/c). Its structure has been determined by X-ray analysis and refined to R = 0.035 The single molecule is internally hydrogen bonded by an N…HN bond between the imidazole and guanidine residue, forming a stable ten-membered ring system. Two neighbouring molecules are linked together in a head to tail arrangement by intermolecular hydrogen bonds of the cyanoguanidine grope to a twelve-membered ring. These pairs of molecules are agglomerated by hydrogen bonds between the imidazole and cyano residues forming waved layers.
Ag2V4O11 nanostructures for highly ethanol sensitive performance

Ag2V4O11 brush-like nanostructures with a large specific surface area have been synthesized by a unique electrochemistry assisted laser ablation in liquids without any template or surfactant in an ambient environment. Considering the large surface-to-volume ratio of the as-synthesized nanostructures, an Ag2V4O11 brush-like nanostructured gas sensor was fabricated and exhibited an excellent performance in sensor response to ethanol concentrations in the range of 10 to 600 ppm under low working temperature. This high response was attributed to the highly crystalline and brush-like surface, which leads to the effective adsorption and desorption, and provides more active sites for gas molecules reacting. These findings show our desire to encourage the synthesis of new nanomaterials, e.g. ternary transition metal oxides, as gas sensors prepared by novel means.
Artifacts in the Determination of Trace Metal Binding Forms in Anoxic Sediments by Sequential Extraction

Abstract The binding forms of Co, Cd, Cu, Pb, and Zn in an anoxic, sulfide-bearing sediment were investigated by performing both thermodynamic equilibrium calculations and sequential extractions. Care was taken to maintain oxygen-free conditions during the whole experiment. The calculations suggested that trace metals were bound to sulfidic minerals. Sequential extraction results, however, showed increased importance of exchangeable and reducible fractions in the order Cu < Cd < Pb < Zn < Co. Thermodynamic equilibrium calculations of the chemical reactions during extraction showed that Cd, Co, Pb, and Zn sulfides are to a significant extent soluble in the acetate-exchangeable (step 1 + 2) and oxalate-reducible (step 3) fractions. Neglecting the dissolution of sulfide minerals would lead to a misinterpretation of the experimental results.
Catalytic regeneration of chloroorganics-saturated activated carbon using hydrodechlorination

A new two-step catalytic process is suggested as viable means for exhaustive regeneration of spent granular activated carbon (AC) saturated with chloroorganic compounds: it incorporates hydrodechlorination (HDC) by hydrogen or by hydrazine followed by oxidation in air. Complete dechlorination of p-chlorophenol (4-CP) was achieved with hydrogen over an AC/Pd catalyst at temperatures in excess of 200 °C. Complete recovery of the adsorption capacity was achieved in three tested cycles of adsorption of 4-CP and regeneration in batch and column studies. Pd is the most suitable catalyst for both HDC and oxidation steps, but the limiting factor of Pd is the possible oxidation of the carbon support and there is a need to increase the oxidation resistance of AC. Dechlorination of 4-CP with an equimolar solution of hydrazine sulfate and ammonium hydroxide is possible over AC/Pd, but the process is much slower.
Toxicity factors in acidic forest soils: attempts to evaluate separately the toxic effects of excessive Al3+ and H+ and insufficient Ca2+ and Mg2+ upon root elongation

The acidic soils of temperate forests and some pastures on former forest land characteristically contain large amounts of aluminium and hydrogen ions and small amounts of calcium and magnesium ions. The relative importance of these potential toxicity factors are assessed from published data from soils collected in the United States and Europe. Activities of ions in the soil solutions and at the surfaces of root‐cell plasma membranes were computed with electrostatic models. Activities of Al3+ in soil solutions ({Al3+}) peaked at pH 4.1, and Al3+ activities at the surface of the plasma membrane ({Al3+}0) achieved a broad maximum between pH 4.1 and 4.8; thus, Al3+ intoxication is likely to be more severe in soils at pH 4.1 than in more acidic ones. Intoxication (assessed by root elongation) correlated somewhat ambiguously with ion activities, but Al3+‐ and H+‐induced depletion of Ca2+ and Mg2+, or both, from the cell surface appears to play a role in toxicity. By contrast, experiments in solution culture, where intercorrelation among {Al3+}, {H+}, and {Ca2+} could be avoided, clearly demonstrated the following extrinsic and intrinsic effects.
Quantitation of microgram amounts of protein in two‐dimensional polyacrylamide gel electrophoresis sample buffer

The concentration of protein actually solubilized in sample buffer in preparation for analysis by two‐dimensional polyacrylamide gel electrophoresis cannot be directly determined by the Lowry, Biuret, or Bradford protein methods due to interference by the combinational effect of presence of urea, detergents, carrier ampholytes, and thiol compounds in sample solubilization buffers. Determinations of the actual amount of protein solubilized and applied to gels is required to accurately quantitatively and qualitatively evaluate second‐dimension polypeptide maps. It was found that when sample buffer consisting of 9 M urea, 4 % Nonidet P‐40, 2 % Ampholines, and 2 % 2‐mercaptoethanol containing solubilized sample(s) was acidified prior to dilution, protein concentrations over a range of 0.5 to 50 μg could be reproducibly determined utilizing a modified Bradford assay. The modified assay generates two near‐linear segments, one over the range < 0.5 to 5 μg total protein that permits the application of Beer's law and a second linear response encompassing 5 to 50 μg total protein. The assay did not tolerate presence of greater than 0.1 % sodium dodecyl sulfate but addition of sodium chloride and protamine sulfate did not adversely affect protein quantitation. The modified assay allows direct quantitation of protein solubilized in sample buffers containing urea, carrier ampholytes, nonionic detergents, and thiol compounds.
Evaluation of certain Ni soil tests for an initial estimation of Ni sufficiency critical levels

Although Ni is officially recognized as an essential micronutrient for all higher plants, the majority of the published research on soil availability of Ni focuses on its hazardous role as a heavy metal. The objective of the study was to evaluate certain Ni soil tests in uncontaminated soils for an initial estimation of its sufficiency critical levels. Nickel was extracted from 30 cultivated soils employing the following extraction methods: DTPA, AB-DTPA, AAAc-EDTA, Mehlich-3, 0.1 M HCl, and 0.1 M HNO3. Ryegrass (Lolium perenne L.) was grown in pots containing the soils, harvested five times, certain plant parameters were determined, and the Cate–Nelson procedures were used for Ni critical levels determination. Among the six methods, HCl was the least reliable extractant for the evaluation of soil available Ni, whereas the most significant (p ≤ 5%) relationships between Ni concentration or Ni uptake by ryegrass and Ni soil tests were consistently obtained for AAAc-EDTA or Mehlich-3 extractable Ni. In many cases, > 80% of the variability of Ni concentration or uptake by ryegrass was explained by these two soil tests without the inclusion of other soil properties that affect Ni bioavailability. Sufficiency critical levels of Ni in soil were ≈ 2 mg kg–1 for both methods. Consequently, as an initial approach, concentrations of AAAc-EDTA or Mehlich-3 extractable Ni < 2 mg kg–1 are probably a good guide to indicate soils that will respond to Ni fertilization.
The Use of Pollutant and Biogenic Markers as Source Discriminants of Organic Inputs to Estuarine Sediments

Abstract The estuarine distributions of a variety of molecular organic markers are described and discussed in relation to sources, transport mechanisms and fates of anthropogenic and biogenic inputs to the Tamar Estuary, U.K. Components selected for study include hydrocarbons (saturated and polycyclic aromatics), sterols, lignins and photosynthetic pigments. Techniques used in the analyses of markers include preparative TLC and HPLC; quantification by HPLC-UV/fluorescence and capillary GC-FID with identification by HPLC-rapid scanning diode array spectrophotometry and computerised capillary GC-MS. Non-parametric cluster analysis and multi-dimensional scaling are employed to resolve co-variability between members of different compound classes to investigate sources and processes affecting fates of the compounds in estuarine environments.
GaAs metal-semiconductor-metal photodetectors with low dark current and high responsivity at 850 nm

In this paper, we report on the fabrication a GaAs metal–semiconductor–metal photodetector with both low dark current and high responsivity at 850 nm. By using the Schottky contacts modified by a thin, n+-doped layer on the surface of the devices, the lowest dark current density of about 4.5 × 10−7 cm−2 was achieved. Besides, in the same devices, the responsivity resulting from a newly designed resonant-cavity-enhanced structure with a superlattice distributed Bragg reflector was about 0.34 A W−1 at 850 nm. The equivalent external quantum efficiency of the devices with equal finger spacing and finger width was about 48%. Our design is relatively easy and reproducible for both the sample growth and the device process.
The Research of Light Pulses on the Inactivation of Escherichia Coli

In this paper, E. coli as experimental subjects ，by changing the input voltage, bacterial concentration, turbidity and pH to study the impact that the use intense white light on the inactivation of E. coli in medium surface. The results showed that: light pulses had a strong effect on lethal E. coli, with the input voltage increasing, the inactivation rate increased. The input voltage is 2500v as an appropriate experimental condition, that satisfy both conservation of energy and a better inactivation . The inactivation rate and the logarithm of livability of E. coli rising with the bacterial concentration increasing, when the light flashes six times, the medium surface almost be killed. Turbidity affect to the inactivation of E. coli, with the turbidity increasing, the effect of the inactivation gradually weakened. When ph was changed, the impact of pulsed light on E. coli inactivation was less . The effect of inactivation achieve the best level when pH was 6.
Phase Diagram of the System KF–AlF3

The system KF–AlF3 was reinvestigated precisely by differential thermal analysis, X-ray diffractometry, and visual observation. All of the samples for the present investigation were prepared by solution synthesis. The results verified the existence of 2KF·AlF3 (K2AlF5) and KF·4AlF3 in the phase diagram; both compounds were orthorhombic. The cell parameters of the compounds were, respectively, a= 10.87 ± 0.03 A, b= 10.36 ± 0.01 A, c= 7.83 ± 0.03 A, and a= 7.89 ± 0.01 A, b= 7.57 ± 0.01 A, c= 6.94 ± 0.01 A. KAlF4 was confirmed to melt congruently at 575°± 2°C by careful examination.
Indirect spectrophotometric determination of phytic acid with zinc chloranilate

The indirect spectrophotometric determination of phytic acid with zinc chloranilate has been studied. The method, based on the measurement of chloranilate released by the replacement reaction of phytic acid and zinc chloranilate, could be used to determine phytic acid in the range of 0.3 to 3.0 × 10−5M. The method showed high reproducibility for measuring phytate in foods, and was more rapid than conventional methods.
Effect of one monolayer of surface gold atoms on the epitaxial growth of InAs nanowhiskers

This letter shows that selective heteroepitaxy of nanometer‐scale InAs whiskers on SiO2‐patterned GaAs substrates [Yazawa, Koguchi, and Hiruma, Appl. Phys. Lett. 58, 1080 (1991)] is induced by surface contamination with Au resulting from the fluorocarbon plasma etching process used to etch the SiO2 mask. We demonstrate that high densities (≂1010/cm2) of InAs nanowhiskers 20–30 nm in diameter can be epitaxially grown on InAs(111)B substrates onto which 1 monolayer of Au atoms had been deposited. This wirelike growth appears to be induced by ultrafine alloy droplets generated by the reactions between Au‐clusters and InAs substrates.
GAS-PARTICLE HEAT TRANSFER IN A DISPERSED BED

Wet activated alumina particles were dried in the constant drying rate period in a dispersed bed. The heat transfer coefficients between the particles and gas were measured. The Nusselt number for gas-particle heat transfer in the dispersed bed was affected by the particle Reynolds number and the void fraction. The empirical equation for gas-particle heat transfer in the dispersed bed was obtained.
Adsorption of Carboxylic Acids on Submicrocrystalline Aluminum Hydroxides in Aqueous Solution. Part I: Qualitative Study by Infrared and Raman Spectroscopy

Adsorption of acetic, oleic, benzoic, and salicylic acids on submicrocrystalline aluminum hydroxide samples is investigated in aqueous solutions. Experimental infrared and Raman spectroscopic data are analyzed to determine the reactivity of the monocoordinated hydroxyl groups located on the edge faces of bayerite or gibbsite crystals. Two key parameters were (1) the effect of concentration of aqueous solutions of the acids, and (2) the variation in specific surface areas of different samples of bayerite and gibbsite powders. Strong preferential adsorption to bayerite was observed over the whole pH range. No adsorption to gibbsite was detected. Data from the literature indicate that acetate, oleate, and benzoate form bidentate complexes on bayerite while salicylate forms a monodentate complex. The infrared spectra show that only monocoordinated hydroxyl groups are reactive, in the bayerite samples, and the band at 1020 cm−1 corresponds to the deformation mode of the monocoordinated hydroxyl groups whose stretching vibration was at 3465 cm−1. It is suggested that the specific surface areas given by the adsorption isotherms is a condition necessary for adsorption, but not sufficient in itself. Adsorption requires the presence of Al-OH2+1/2 species as well as the presence of steps or of a packaging sequence ABABABA rather than a packaging sequence ABBAABBA of the hydroxyl planes. The gibbsite impurity present in the bayerite sample reacted completely, while the lateral OH in the gibbsite sample did not, reflecting the lower reactivity in gibbsite relative to extended domains of bayerite.
A new optical method and apparatus `HAUP' for measuring simultaneously optical activity and birefringence of crystals. I. Principles and construction

A new and accurate method has been developed by which all the components of the anisotropy of the optical susceptibilities can be determined. The apparatus based on this method has been constructed, and named as HAUP (High-Accuracy Universal Polarimeter). The basic principle is to measure the intensity of the light beam, which is propagated successively through a polarizer, a specimen, and an analyser, as functions of azimuth and deflecting angle from the crossed-Nicols condition. Thus the method is characterized by its extreme simplicity, which prevents systematic errors. Considerations and tests of inevitable systematic errors are made. The systematic errors originating in the parasitic ellipticities of the polarizer and analyser are found to be serious for the measurements of optical activity; appropriate solutions to remove them are devised here. Sensitivities of measurements of optical activity and birefringence by the HAUP method reach 4.8 × 10−8 and 2.2 × 10−6 respectively, the accuracy being 4.2 × 10−3 and 2.2 × 10−3 respectively. By using HAUP it has become possible to measure simultaneously all the components of optical activity, birefringence and rotation of optical indicatrix of any crystals, including those belonging to the monoclinic and triclinic systems. These measurements can be made from about 400 K down to 10 K. Also, simultaneous determinations of electrogyration and electrooptic coefficients have become feasible by applying electric fields to crystals.
Calibration of the automated z‐axis of a microscope using focus functions

Applications in automated microscopy and three‐dimensional microscopy require careful calibration of the microscope system. This paper presents methods for calibration of the motorized z‐axis (focus or optical axis) of an automated microscope. Apart from the automated microscope the procedures require a CCD camera and a test slide containing a simple bar pattern. The calibration embraces the following characteristics of the z‐axis: (a) measuring the motor step size in nanometres; (b) measuring the mechani‐cal backlash in the focus mechanism of the microscope and (c) measuring the reproducibility and the stability of the focus position over time. The measurements employ focus functions to determine the z‐position of the microscope stage.