Miracle-dz/UniFAR-FTUs huggingface dataset:
Turbidity Removal from Wastewaters of Natural Stone Processing by Coagulation/Flocculation Methods

The effectiveness of coagulation (at pH values of 6, 7.5, and 9), flocculation (at pH 9), and coagulation plus flocculation (at pH 9) on turbidity removal from natural stone (travertine) processing wastewaters (NSPW) were examined by applying classical sedimentation tests. FeCl 3 ·6H 2 O, AlCl 3 , and Al 2 (SO 4 ) 3 ·16H 2 O were used as coagulants and a polyacrylamide based anionic polymer was used as the flocculant. In this way, it was found that the coagulation method alone was not sufficient to purify NSPW, whereas flocculation and coagulation plus flocculation methods provided superior purification. Among the coagulants used, AlCl 3 gave the best result in terms of turbidity removal by coagulation from NSPW at pH 6 and 9, whereas the turbidity removal performances of the three coagulants were almost identical at pH 7.5. In addition, relatively low pH (i.e., pH 6) improved the purification performance of all coagulants. During coagulation of NSPW at pH 6, a charge neutralization mechanism played a decisive role in turbidity removal. However, in neutral (pH 7.5) and slightly basic (pH 9) media, a sweep coagulation mechanism was predominant. For flocculation of NSPW, the basic mechanism comprised of polymer bridging.
Detecting orientational order in model systems by X-ray cross-correlation methods

The results of a computational X-ray cross-correlation analysis (XCCA) study on two-dimensional polygonal model structures are presented. This article shows how to detect and identify the orientational order of such systems, demonstrates how to eliminate the influence of the `computational box' on the XCCA results and develops new correlation functions that reflect the sample's orientational order only. For this purpose, the dependence of the correlation functions on the number of polygonal clusters and scattering vector magnitude q is studied for various types of polygons, including mixtures of polygons and randomly placed particles. An order parameter that describes the orientational order within the sample is defined. Finally, the influence of detector noise and nonplanar wavefronts on the XCCA data is determined, both of which appear to affect the results significantly and have thus to be considered in real experiments.
Pressure and temperature dependence of the self-diffusion of benzene

The self-diffusion coefficient of liquid benzene has been measured with a modified diaphragm cell. The cell incorporates a bellows in one compartment and the technique for its use makes allowance for bulk flow effects due to changes in pressure. Results have been obtained at 288, 298, 313 and 328 K over the pressure range 1–283, 1–645, 1–975 and 1–1496 bar, respectively and used to calculate activation energies and volumes. In contrast to earlier (less accurate) data the present results indicate a non-linear dependence of log D on pressure. The results are used to test a quasi-lattice model of the liquid. The Stokes-Einstein relation is obeyed over only a narrow density range.
Kinetics and mechanism of oxidation of Chitosan Polysaccharide by Permanganate Ion in Aqueous Perchlorate Solutions

The kinetics of oxidation of chitosan as polysaccharide by permanganate in aqueous perchlorate media at a constant ionic strength was found to have second-order overall kinetics and to be first-order in the concentration of both reactants, the results obtained showed that the reaction is acid catalysed.
Drying of Xanthan Gum Using a Two-Dimensional Spouted Fluidized Bed (2DSFB) with Inert Particles: Performance and Rheological Considerations

Xanthan commercial gum was dried using a two-dimensional spouted fluidized bed dryer (2DSFB) with inert particles under different conditions of temperature, suspension feed rate, and air flow in the spout and annulus. Performance characteristics of drying processing, flow characteristics of the bed, and influence of the drying variables on rheological behavior of product were evaluated. The results indicated that xanthan suspension can be dried out in a spout-fluidized bed without several damages in its rheological behavior. In addition, the lower feed rate was the main factor to decrease viscosity and elastic character of xanthan, which was associated to a depolimerization caused by shearing for an extended processing time.
MULTICOMPONENT POLYMER/SOLVENTS EQUILIBRIA: AN EVALUATION OF FLORY-HUGGINS THEORY FOR CROSSLINKED PDMS NETWORKS SWELLED BY BINARY MIXTURES

The prediction of equilibrium volume fractions of solvents mixtures in a polymer network is of utmost importance for processes dealing with polymeric materials (e.g. chromatographic and membrane processes). Up to now, few studies have studied the ability of existing theories to predict experimental multicomponent sorption data in polymers; this work intends to achieve that purpose on model liquid mixtures in contact with silicone rubber (polydimethylsiloxane). The equilibrium volume fractions of three liquid mixtures (chloroform/toluene; ethanol/toluene; ethanol/2-butanol) in crosslinked PDMS samples have been determined experimentally at 40°C. Results are compared to predictions by the Flory-Huggins theory applied to ternary mixtures (one polymer and two liquids) with constant interaction parameters and negligible elastic contribution. Solvent/polymer interaction parameters have been determined by swelling the crosslinked samples in pure liquids, while liquid/liquid interaction parameters have been estim.
Study on the Kinetics for Enzymatic Degradation of a Natural Polysaccharide, Konjac Glucomannan

The enzymatic degradation of konjac glucomannan (KGM) was conducted using β-mannanase from an alkalophilic Bacillus sp. in the aqueous medium (pH 9.0) at 30°C. The intrinsic viscosity ([η]), molecular weight (M w ) and molecular weight distribution (MWD) of the degraded KGM were measured. The mathematical relation between [η] and M w , [η] = 5.06×10 -4 M w 0.754 , was established. The kinetic analysis reveals a dependence of the rate constant (k) on the period of reaction and the initial substrate concentration (c 0 ) over the range of substrate concentration (1.0∼2.0%) used in this work. The results indicate that the enzymatic degradation of KGM is a complex reaction combining two reaction processes with different orders. In the initial phase of degradation k is inversely proportional to c 0 , which is characteristic of a zeroth-order reaction; while in the following phase k is independent of c 0 , implying the degradation follows a first-order reaction. The reactivity difference in breakable linkages of KGM, the action mechanism of an enzyme on KGM macromolecules, and the theory concerning the formation of an enzyme-substrate complex and 'substrate saturation' can be used to explain such a kinetic behavior. In addition, the enzymatic degradation of KGM was also carried out using the other enzymes like β-mannanase from a Norcardioform actinomycetes, β-glucanase Finizym and a compound enzyme Hemicell as a biocatalyst. By comparing and analyzing the degradation processes of KGM catalyzed by four different enzymes, it can be observed that there is a two-stage reaction with two distinct kinetic regimes over a certain range of degradation time for each of the degradation processes. These results are useful to realize controllable degradation of polysaccharides via an environmental benign process.
PERNOD - Ein Programm zur Verfeinerung von Kristallstrukturparametern aus Neutronenbeugungspulverdiagrammen

The program PERNOD described in this paper serves to refine crystal structure parameters from neutron powder diffraction data. The observed powder diagram is subdivided into groups of reflexions. The chosen boundaries of these groups are corrected by the program to obtain the best fit between a calculated line profile and the observed diagram. The observed intensities of reflexion groups obtained in this way are then split up into `observed' intensities of single reflexions using preliminary calculated reflexion intensities. The atomic parameters are refined using the ORFLS program, where the lattice constants are refined with the help of the line profile itself. As an example the atomic parameters of wolframite CuWO4 are refined.
LIPIDS FROM SAMPLES OF SKIN FROM SEVEN DUTCH BOG BODIES: PRELIMINARY REPORT

A combination of micro-analytical techniques including thin layer chromatography (TLC), gas chromatography (GC). and combined gas chromatography/mass spectrometry (GCIMS) have been employed to study the lipid compositions of samples of skin from seven Dutch bog bodies. TLC showed that, while phospholipids have been degraded, other acyl lipids, for example triacylglycerols and steryl esters, may remain intact. GC and GC/MS analyses, following treatment of the total lipid extracts with acidified methanol, showed the presence of abundant fatty carboxylic acids and sterols. Molecular analysis by GC/MS allowed distinctions to be drawn between components originating from the bog body and the surrounding peat. Additionally, substances derived from microbial alteration of endogenous skin lipids and from the lipids of the micro-organisms themselves can be distinguished.
Prediction of clay content from water vapour sorption isotherms considering hysteresis and soil organic matter content

Soil texture, in particular the clay fraction, governs numerous environmental, agricultural and engineering soil processes. Traditional measurement methods for clay content are laborious and impractical for large‐scale soil surveys. Consequently, clay prediction models that are based on water vapour sorption, which can be measured within a shorter period of time, have recently been developed. Such models are often based on single‐point measurements of water adsorption and do not account for sorption hysteresis or organic matter content. The present study introduces regression relationships for estimating clay content from hygroscopic water at different relative humidity (RH) levels while considering hysteresis and organic matter content. Continuous adsorption/desorption vapour sorption isotherm loops were measured for 150 differently textured soils with a state‐of‐the‐art vapour sorption analyser within a RH range from 3 to 93%. The clay contents, which ranged between 1 and 56%, were measured with a combination of sieving and sedimentation methods. Two regression models were developed for both adsorption and desorption at 10 RH levels (5, 10, 20, 30, 40, 50, 60, 70, 80 and 90%). While the first model encompasses all 150 soils regardless of organic carbon (OC) content, the second model considers only soils with OC<2.4%. Independent validation of the proposed regression models at 50, 60 and 90% RH using literature data for water vapour adsorption showed reasonably accurate (average RMSE = 5.0%, ME = 2.4%) prediction of clay contents. However, the model for soils with small OC contents showed only minor improvement when compared with recently published models. Three main sources of prediction errors, namely large OC and silt contents, and a prevalence of 1:1 clay minerals were identified for both the proposed and published models. To compensate for large OC content, an OC‐corrected model was developed and compared with the other models. The corrected model markedly improved clay prediction accuracy for OC‐rich soils when compared with all other models considered.
Growth of Aligned ZnO Nanorods Grown on Polyethylene Naphthalate Substrates: Effect of the Growth Duration

Aligned ZnO nanorods were synthesized on a polyethylene naphthalate (PEN) substrates using a chemical bath deposition method. The growth temperature and precursor concentration were 95 °C and 0.025 M, respectively. The effects of growth duration (2 h to 8 h) on the optical and structural properties of the obtained ZnO nanorods on seed layer ZnO/PEN substrate were then investigated using X-ray diffraction, field-emission scanning electron microscopy (FESEM), and photoluminescence (PL) spectroscopy at room temperature. The high intensity of (002) peak compared with (100) and (101) in the X-ray diffraction (XRD) pattern demonstrated that the ZnO nanorods grown for 6.5 h had more vertical higher crystal quality than the samples grown for other durations. The average diameter of ZnO nanorods grown on PEN substrates increased from 19 nm to 45 nm with increased growth duration from 2 h to 8 h, respectively.
Evidence for Enhanced Mineral Dissolution in Organic Acid‐Rich Shallow Ground Water

Total concentrations of formate, acetate, and isobutyrate varied from less than 5 to greater than 9,000 μmol/l over distances of < 3 m in ground water from a shallow hydrocarbon contaminated aquifer. Laboratory incubations of aquifer material indicate that organic acid concentrations were dependent on the amount of hydrocarbon loading in the sediment and the relative rates of microbial organic acid production and consumption. In heavily contaminated sediments, production greatly exceeded consumption and organic acid concentrations increased. In lightly contaminated sediments rates were essentially equal and organic acid concentrations remained low. Concentrations of dissolved calcium, magnesium, and iron generally were one to two orders of magnitude higher in organic acid-rich ground water than in ground water having low organic acid concentrations. Carbonate and Fe(III)-oxyhydroxide minerals were the likely sources of these elements. Similarly, concentrations of dissolved silica, derived from quartz and k-feldspar, were higher in organic acid-rich ground water than in other waters. The positive relation (r = 0.60, p < .05, n = 16) between concentrations of silica and organic acids suggests that the microbially mediated buildup of organic acids in ground water enhanced quartz/k-feldspar dissolution in the aquifer, although it was not the only factor influencing their dissolution. A model that included organic acid microequivalents normalized by cation microequivalents significantly strengthened the correlation (r = 0.79, p < .001, n = 16) between dissolved silica and organic acid concentrations, indicating that competition between silica and cations for complexation sites on organic acids also influenced quartz/k-feldspar dissolution. Physical evidence for enhanced mineral dissolution in organic acid-rich waters included scanning electron microscopy images of highly corroded quartz and k-feldspar grains from portions of the aquifer containing organic acid-rich ground water. Microporosity generated in hydrocarbon contaminated sediments may adversely affect remediation efforts that depend on the efficient injection of electron acceptors into an aquifer or on the recovery of solutes from an aquifer.
Soil Phosphorus Extracted By Iron-Aluminum-Oxide-Impregnated Filter Paper

The use of Fe-Al-oxide-impregnated paper strips may allow estimation of plant-available P contents of soils with widely differing properties. Little information is available on the forms of P extracted by paper strips (SP). Relationships between SP and Olsen, Bray I, Mehlich III, and P fractions were investigated for 203 surface soils representing all soil orders. Soils were divided into calcareous, slightly weathered, and highly weathered groups, based on taxonomy and weathering. Amounts of P extracted by paper strips were closely correlated (r2 of 0.89 to 0.93, P > 0.001) with soil-test P (Olsen, Bray I, and Mehlich III), for soils on which use of the test is recommended. It is suggested that the paper strips removed primarily physically bound extractable P from all soils (approximate 1:1 relationship), with little extraction of amorphous Al and Fe or Ca compounds indicated. A potential general applicability of Fe-Aloxide-impregnated paper strips to estimate plant-available soil P is
Calculation of Energy Levels for Internal Torsion and Over‐All Rotation. II. CH3CHO Type Molecules; Acetaldehyde Spectra

Methods are described for the calculation of energy levels for the over‐all rotation and internal torsion of molecules with a plane of symmetry and one symmetric internal rotor. Typical examples are CH3CHO, CH3SiH2D, and CH3OH. Analysis of the microwave spectra of CH3CHO, CD3CDO, CD3CHO, CH2DCHO, CHD2CHO, C13H3CHO, CH3C13HO, C13H3C13HO, and CH3CHO18 yields V 3=1162, 1151, 1143±30 cal, and V 6<100 cal, respectively, for the first three isotopic species, where the barrier to internal rotation is V=V 3(1—cos3α)/2+V 6(1—cos6α)/2. The aldehyde oxygen was found to be opposite one of the methyl hydrogens in the equilibrium orientation of the methyl group. The measured moments of inertia of the nine isotopic species lead to a structure with the parameters Methyl group: C–H=1.086 A C–D=1.088 H–C–H=108°16′ D–C–D=108°32′ C–C=1.501 Aldehyde: C–H=1.114 C=0=1.216 C–C–H=117°29′ C–C–O=123°55′ The Stark effect gave a dipole moment of 2.69 debyes.
Separation of cobalt and nickel from acidic sulfate solutions using mixtures of di(2‐ethylhexyl)phosphoric acid (DP‐8R) and hydroxyoxime (ACORGA M5640)

DP-8R and ACORGA M5640 extractants diluted in Exxsol D100 were used to co-extract cobalt and nickel from aqueous acidic sulfate media. The influences of equilibration time, temperature, equilibrium pH and reagent concentrations on the extraction of both metals have been studied. It was observed that both cobalt and nickel extraction are slightly sensitive to temperature but are pH dependent. Metal extraction equilibria are reached within about 5 min contact time. In addition, cobalt extraction depends on the extractant concentration in the organic phase. For a solution containing 0.5 g dm−3 each of cobalt and nickel and an initial pH of 4.1, conditions were established for the co-extraction of both metals and selective stripping (with H2SO4) of cobalt and nickel. Using the appropriate reagent concentrations the yield (extraction stage) for both metals exceeded 90%, and stripping of cobalt and nickel was almost quantitative. Copyright © 2004 Society of Chemical Industry
Plasma probe characteristics in low density hydrogen pulsed plasmas

Probe theories are only applicable in the regime where the probe’s perturbation of the plasma can be neglected. However, it is not always possible to know, a priori, that a particular probe theory can be successfully applied, especially in low density plasmas. This is especially difficult in the case of transient, low density plasmas. Here, we applied probe diagnostics in combination with a 2D particle-in-cell model, to an experiment with a pulsed low density hydrogen plasma. The calculations took into account the full chamber geometry, including the plasma probe as an electrode in the chamber. It was found that the simulations reproduce the time evolution of the probe IV characteristics with good accuracy. The disagreement between the simulated and probe measured plasma density is attributed to the limited applicability of probe theory to measurements of low density pulsed plasmas on a similarly short time scale as investigated here. Indeed, in the case studied here, probe measurements would lead to, either a large overestimate, or underestimate of the plasma density, depending on the chosen probe theory. In contrast, the simulations of the plasma evolution and the probe characteristics do not suffer from such strict applicability limits. These studies show that probe theory cannot be justified through probe measurements. However, limiting cases of probe theories can be used to estimate upper and lower bounds on plasma densities. These theories include and neglect orbital motion, respectively, with different collisional terms leading to intermediate estimates.
The crystal structure of tetragonal ZrO2

In the course of a high-temperature x-ray diffraction study of tetragonal ZrO/sub 2/, a number of previously unreported reflections, which are inconsistent with a body-centered lattice, hare been observed. The intensities of most of these reflections are rather low, but the strongest of these (the (102) reflection) was observed throughout the temperature range from 1200 to 1950 deg C. during heating and from 1950 to 900 deg C. during cooling, both in purified ZrO/sub 2/ as well as in specimens containing about 2% of hafnium. (R.J.S.)
The preparation and use of cells for the realization of the triple point of water

The Ninth General Conference of Weights and Measures(1,2) which met in October 1948 passed a resolution that the zero of the International Temperature Scale should be defined as being the temperature 0.0100° C below that of the triple point of water. The technique used at Teddington for preparing cells for the realization of the triple point of water is described and the results obtained by the use of these cells over an extended period are discussed.
Plasmonic properties of silver trimers with trigonal symmetry fabricated by electron-beam lithography

We investigate the dipolar plasmon modes of nanoparticle trimers formed by three equal silver disks of diameter D = 100 nm located on the vertexes of an equilateral triangle. Samples were fabricated by electron-beam lithography and studied experimentally by dark-field spectroscopy. The results are found to be in good agreement with electrodynamical simulations based on the discrete dipole approximation (DDA). Similar to nanoparticle dimers, the trimer system exhibits two hybridized dipole resonances to the red and to the blue of the single particle resonance. However, the far-field spectra are polarization-insensitive for light incident normal to the plane of the trimer, and the peak shifts, which occur as the edge-to-edge distance d between the particles decrease, are smaller than for dimers. Moreover, we find that the dipolar displacement patterns are well described by linear combinations of bonding and antibonding symmetry adapted coordinates obtained through symmetry analysis based on the ideal D-3h point-group.
Growth and Studies of Pure and Lithium Bromide-Doped Zinc Tris-Thiourea Sulphate (ZTS) Single Crystals

Single crystals of pure and lithium bromide-doped Zinc Tris-thiourea Sulphate (ZTS) were grown from aqueous solutions by slow evaporation technique. The grown crystals were subjected to various studies such as X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), atomic absorption, and Second Harmonic Generation (SHG) studies. The density, melting point, DC conductivity, AC conductivity, dielectric constant, and activation energy of the grown crystals were also measured. The various studies revealed the incorporation of the impurity (lithium bromide) into ZTS crystals, and the investigations indicated that the impurity played an important role in the changes of the spectral and structural properties of ZTS crystals.
X-ray Spectroscopic and Magnetic Investigation of C:Ni Nanocomposite Films Grown by Ion Beam Cosputtering

The nearest-neighbor coordination and electronic structure in C:Ni(∼30 at.%) nanocomposite films grown by ion beam cosputtering in the temperature range of room temperatue (RT) to 500 °C are investigated by the means of extended X-ray absorption fine structure (EXAFS), X-ray absorption near-edge spectroscopy (XANES) and X-ray photoelectron spectroscopy (XPS). The obtained results are correlated with the composite nanostructure published elsewhere and magnetic properties determined by the means of X-ray magnetic circular dichroism (XMCD) and superconducting quantum interference device (SQUID) magnetometry. A combined use of EXAFS, XANES, and XPS shows that a carbidic Ni phase exhibiting only local atomic ordering is formed at low growth temperatures (≤200 °C), while ordered carbidic Ni phase forms at ∼300 °C. Further increase in growth temperature results in the formation of face-centered cubic (fcc) Ni with a high degree of crystallinity. On the other hand, Ni incorporation strongly promotes the formation.