Miracle-dz/UniFAR-FTUs huggingface dataset:
Equation of state and miscibility behavior of compressible binary lattice polymers. A Monte Carlo study and comparison with partition function theories

In a continuing study on the properties of the compressible lattice model, the equation of state and miscibility behavior of binary mixtures of lattice chains is explored. Monte Carlo simulations are performed in the NpT and semi-grand-canonical μpT ensemble for varying compositions and several combinations of the three interactional parameters characterizing the binary mixture. In all simulations the chain lengths of both components are taken to be equal. In addition to the thermodynamic information, microscopic information on the number of different contacts and the mean square end-to-end distance is collected, too. The Monte Carlo results are used to examine the predictions of lattice model theories derived from statistical mechanics. To this purpose the nonrandom mixing theory for the binary compressible mixture, based on the quasi-chemical approximation of Guggenheim, is presented. The theory is compared in detail to the collected simulation data. Although the theory is completely general, the compar.
Potential for On-Site Analysis of Hog Manure Using a Visual and near Infrared Diode Array Reflectance Spectrometer

In this study, a diode array near infrared (NIR) spectrometer that can be mounted on a mobile agricultural machine was tested under lab conditions for its effectiveness as a rapid, on-site hog (Sus domesticus) manure composition sensor. One hundred and sixty nine diverse hog manures, collected from farms in the northern part of Belgium, were assayed by conventional wet chemical analysis and spectroscopy for the following constituents: dry matter content, organic matter content, pH, total Kjeldahl nitrogen, ammonium nitrogen, phosphorus, potash, calcium, sodium and magnesium. Samples were scanned (two fills, three measurements each) on a Zeiss Corona 1.7 VisNIR diode array instrument equipped with an OMK measuring head, ranging between 400 and 1700 nm (five scans per measurement) using a sample cell (50 mm diameter) for diffuse reflectance scanning from the bottom. Based on the absorbance–constituent and constituent–constituent correlations, the constituents were divided into two groups: one for those in the solids (dung) and one for those in the liquid (urine). The pH was not correlated to any other constituent and, therefore, treated separately. Partial least squares calibrations were developed for the constituent groups and for each of the constituents separately using leave-one-out cross-validation, showing a common spectral basis for each constituent group. To investigate the possibility of developing a cost-effective sensor, regression calibrations were developed using a few wavelengths selected based on the partial least squares regression and validated by leave-one-out cross-validation. Results demonstrated that: (1) approximate quantitative predictions can be made for total N, NH4–N and K, (2) a discrimination between high and low values can be made for DM, OM, P and Mg, (3) prediction of Ca, Na and pH are not possible (yet), (4) one measurement and one filling of the cup give a reliable measurement, (5) a cost-effective sensor measuring only a few appropriately selected wavelengths might be able to give comparable results, (6) further work will be necessary to optimise sample presentation and calibration procedures and (7) mounting a diode array instrument on a slurry tanker can make environmentally and economically sound nutrient management possible.
Diffusion of oxygen through a pulp and paper residue barrier

Acid mine drainage can be curbed or reduced significantly by covering tailings sites with an oxygen barrier. In this study, the ability of pulp and paper residues, more specifically deinking residues, to function as such a barrier was investigated. Field data from two sites show that O2 diffusion through the barriers can be greatly reduced. To better understand how oxygen migrates through deinking residues and to develop prediction tools for future design with deinking residues, one-dimensional effective diffusion coefficients (De) were determined by fitting laboratory experimental curves (O2 concentration versus time data) to curves obtained from computer simulations. The results obtained confirmed the behaviour observed in soil covers: the effective diffusion coefficients are highly dependent on the degree of saturation (Sr) of the compacted material. The De values obtained in this study compare well with those published in the literature for several materials compacted at similar Sr. The De values vari.
GAS ABSORPTION IN STIRRED GAS-LIQUID-LIQUID SYSTEMS: EFFECT OF TRANSFERRED SOLUTE SOLUBILITY AND OIL PHASE SPREADING CHARACTERISTICS

The effect on gas-liquid mass transfer of dispersing an oil phase in water in an aerated stirred tank is not predictable, because the mechanisms involved are not well understood. To try to elucidate these mechanisms, a set of experiments was carried out that included: (i) measurement of the effect of oil addition on gas dispersion properties, (ii) quantification of mass transfer of two solutes (heptane and oxygen) with very different solubilities in the liquid phases, and (iii) variation of the spreading characteristics of the oil phase, which consisted of mixtures of dodecane and heptane in varying concentrations. It was found that in the case of heptane mass transfer, when the oil spreading coefficient S changes from negative to positive, the outlet gas becomes practically saturated, corresponding to a several-fold increase in mass transfer coefficient. In the case of oxygen mass transfer, the effect of S is not as dramatic, but it is also quite significant. For a spreading oil phase (S > 0), the mass transfer coefficient decreases upon trace oil addition, going through a minimum as oil holdup increases, and then increasing steadily. In the case of a non-spreading oil phase, mass transfer coefficient initially increases with oil holdup increase, going through a maximum and then decreasing. Comparison between mass transfer coefficients for the two solutes indicates that kLa for heptane is larger than that of oxygen by a margin not explainable through the difference in diffusivities, which is evidence for a difference in transfer paths/mechanisms. A physical interpretation compatible with these results is offered.
Primary Clarification of Banana Juice Extract by Centrifugation and Microfiltration

Banana is a much appreciated tropical fruit due to its unique aroma, flavor, and also for its nutritional and energetic components. In this work, banana juice was extracted by pectinase treatment at room temperature. The resultant juice was clarified by two methods, namely, centrifugation and microfiltration. A comparative study was performed between these two primary clarification methods. Response surface methodology was used to optimize the parameters of centrifugation (speed and time) as well as microfiltration (transmembrane pressure and cross flow rate). The juice was characterized in terms of viscosity, clarity, alcohol insoluble solids (AIS), polyphenol, and protein content. Centrifuged juice contained high concentration of total polyphenol and protein. Juice obtained from microfiltration had lower viscosity, AIS, and higher clarity. Also, the energy consumption of the centrifuge is much higher than that of microfiltration.
Stability - Indicating Hplc Assay for Paracetamol, Guaiphenesin, Sodium Benzoate and Oxomemazine in Cough Syrup.

Abstract A stability-indicating, specific, sensitive and validated reversed-phase HPLC assay for paracetamol, guaiphenesin, sodium benzoate and oxomemazine in the presence of degradation products, i.e. 4-aminophenol and guaicol, as well, as the co-formulated adjuvants and 5-hydroxymethylfurfural, a commonly formed compound in syrups during formulation and/or storage of pharmaceutical syrups, has been developed to allow simultaneous determination of these compounds in a cough syrup. The HPLC method includes the use of a two-line solvent delivery system. The specificity, precision in term of both repeatability (i.e. intraday precision) and reproducibility (i.e. interday precision), limit of detection of the degradation products and ruggedness due to column to column batch and source variation have been discussed. The developed method has been applied for the determination of the main drugs and their degradation products in freshly prepared as well as in stored samples of cough syrup.
Postfrontal nanoparticles at Cape Grim: observations

Environmental context. Clouds and the factors controlling cloud properties are essential components in understanding and accurately predicting global climate change. This work examines nanometre-sized atmospheric particles, particularly bursts of enhanced particle concentrations following cold fronts over the Southern Ocean. The properties of these events have been established to enable modelling of their significance as a source of cloud-droplet-forming nuclei. Abstract. Nanoparticles (diameter <10 nm) were studied in clean maritime air at Cape Grim over a 2-year period. Concentrations were determined using a condensation nucleus counter (CNC) and an ultra-CNC (UCNC), requiring careful treatment of drifts in counter efficiency. This is the first extended examination of nanoparticles following cold fronts and shows that nanoparticle enhancements were present following 94% of 121 cold fronts studied. Typical enhancements were ~100 cm–3 with maxima ~300–500 cm–3, occur 9–11 h after the front and contain multiple peaks with peak-to-peak separation of 8–11 h. Most enhancements were associated with drier conditions, indicative of increased entrainment of free-tropospheric air after the front. The quasi-periodicity of the enhancements may be related to mesoscale structures in cloud fields following fronts but this requires testing. This quantification of event properties allows evaluation of the significance of these events for the cloud nucleating particle (CCN) population.
The crystal structure of ice at low temperatures

The use of X-ray in the study of the mechanism of crystal growth showed that if the vapour of a substance came in contact with a cold surface, it condensed to form a solid, the structure of which depended on the temperature of the condensing surface. The authors announced recently that ice formed by condensation at low temperatures and pressures also changed form with temperature. Details of the apparatus and the results follow in this paper. 2-Method and Preliminary Work Analysis was carried out by the Hull-Debye-scherrer method, using the Ka doublet of copper. With a camera of 5 cm radius, photographs were obtained in 4 to 6 hours, using a shearer tube operated at 30 KV (R. M. S.) and 10 mA. The Ks line was removed from the radiation by a filter of nickel foil.
Interaction between water and fluorine-doped silicon oxide films deposited by plasma-enhanced chemical vapor deposition

The interaction between water and fluorine-doped silicon oxide (SiOF) films has been studied using Fourier transform infrared spectroscopy and thermal desorption spectroscopy. The effects of the interaction on the relative dielectric constant of films were also studied using capacitance–voltage measurements. It was found that SiOF films with high fluorine concentration have three absorption bands attributable to Si–Fn stretching vibration, however, the SiOF films have only one absorption band after humidification. The residual band is assumed to be attributable to silicon monofluoride [Si(O–)3F] sites and the disappearing bands are attributable to silicon difluoride [Si(O–)2F2] sites. Si(O–)2F2 sites are hydrided during humidification and generate Si–OH bonds and HF in the film. In addition, Si(O–)2F2 sites increase the water absorbed in film. The relative dielectric constant of SiOF films capped by silicon nitride decreased steadily with increased fluorine concentration, from 4.5 (SiO2) to less than 2.8 [11.5 at. % (F)], however, that of uncapped SiOF films saturated the decrease at about 3.6 in films having 7.6 at. % (F) or more. This saturation is caused by the increase of Si(O–)2F2 sites in film because the ratio of Si(O–)2F2 sites to total fluorine bonding sites increases markedly at a fluorine concentration above 7.6 at. % (F). Si(O–)2F2 sites increase Si–OH bonds and water absorbed in film, and both, in turn, increase the film dielectric constant.The interaction between water and fluorine-doped silicon oxide (SiOF) films has been studied using Fourier transform infrared spectroscopy and thermal desorption spectroscopy. The effects of the interaction on the relative dielectric constant of films were also studied using capacitance–voltage measurements. It was found that SiOF films with high fluorine concentration have three absorption bands attributable to Si–Fn stretching vibration, however, the SiOF films have only one absorption band after humidification. The residual band is assumed to be attributable to silicon monofluoride [Si(O–)3F] sites and the disappearing bands are attributable to silicon difluoride [Si(O–)2F2] sites. Si(O–)2F2 sites are hydrided during humidification and generate Si–OH bonds and HF in the film. In addition, Si(O–)2F2 sites increase the water absorbed in film. The relative dielectric constant of SiOF films capped by silicon nitride decreased steadily with increased fluorine concentration, from 4.5 (SiO2) to less than 2.8 .
Removal of aqueous phenol and 2-chlorophenol with purified soybean peroxidase and raw soybean hulls

In this study, the removal of phenol and 2-chlorophenol using soybean seed-hulls in the presence of hydrogen peroxide is demonstrated. The performance of a stirred membrane reactor containing soluble purified SBP was compared with a batch stirred reactor containing raw soybean seed-hulls. The purified enzyme reactor proved to be ineffective while excellent results were obtained with the crude seed-hulls for the removal of phenol and 2-chlorophenol. Four sequential batch reactors containing raw seed-hulls achieved greater than 96% removal of phenol with a retention time of 20min in each reactor. A single batch reactor containing raw seed-hulls was effective in removing greater than 98.5% of 2-chlorophenol (initially at 1000 ppm) in less than 15 min. The performance of these reactors is comparable to existing HRP-based technology. The stability of the soybean peroxidase (SBP) enzyme was also examined in the presence of detergents (SDS, Tween 20 and Triton X-100). Low concentrations of the detergents significantly increased the enzyme activity and higher concentrations of detergents (up to 20% w/v) did not inactivate the SBP enzyme. These results demonstrate that SBP has good potential for the treatment of phenol contaminated solutions.
Application of various methods of nonisothermal kinetic analysis to magnesium hydroxide decomposition

In the present study the determination of the mechanism of the thermal decomposition of magnesium hydroxide from thermogravimetric experiments is attempted. For this purpose nonisothermal kinetic analysis of the dynamic experimental data is applied, using different methods, which are based on the best linearization of a functional form of the Arrhenius equation. The experiments were carried out under nonisothermal conditions in a thermogravimetric analyzer with nitrogen atmosphere, at five different heating rates, i.e., 3, 8, 15, 20, and 35 deg/min. The nonisothermal methods used for the kinetic analysis of the experimental data were the Coats-Redfern method, the Romero et al., the improved Coats-Redfern method, the differential method, the differential by Jerez et al., and a method using the heating rate as a variable. Applying each of these methods, the kinetic parameters and, in most cases, the form of the conversion function (kinetic model) which governs the dehydroxylation process of Mg(OH)2 were determined. From the comparative study of the results of the above methods and using criteria about the credibility of each method, it was concluded that the kinetic model which represents the mechanism of the dehydroxylation of magnesium hydroxide, is that corresponding to the two dimensions nucleation with a reference value of activation energy 117.67 kJ/mol. © 1993 John Wiley & Sons, Inc.
Modal analysis of pyroclastic rocks by combined Rietveld and RIR methods

The modal analysis of samples belonging to the zeolite-rich pyroclastic formation named “Neapolitan yellow tuff” (Central and Southern Italy) has been determined by full-profile refinement of X-ray powder diffraction (XRPD) data using a combined Rietveld–RIR method. The quantitative analysis and especially the zeolite content is a profitable source for geo-petrographic and genetic considerations and as well an essential source to assess the physical and chemical properties of the bulk material for a feasible use in industrial applications. Albeit a wealth of methods are used for the quantitative determination of zeolite content in pyroclastites they all fail for lack of accuracy as far as concerns the absolute standard deviation of the quantitative data. The outstanding outcomes achievable by using the Rietveld method make it as the most promising technique to fulfill this lack. The glass content in each sample is calculated by a combined Rietveld–RIR method in which a known amount of an internal standard is added to the mixture to rescale the Rietveld refined weight fractions into absolute values. Then, it is reasonable to designate this method as an external method according to the definition given by Hill and Howard (1987). Its counterpart is the internal method developed by Riello etal. (1995a,b). Other techniques such as the addition method and the background scattering volume calculation are developed to accomplish a further determination of the glass content. The results are compared to the values obtained from the Rietveld–RIR analysis. These experimental methods yield an over-estimation of the amorphous phase because the incoherent scattering contribution (air, absorption, sample holder, Compton scattering) is accounted for as the amorphous fraction itself. The glass content of each sample acquired from the Rietveld–RIR refinement on the “raw data” is compared to that accomplished from the refinement of incoherent scattering subtracted data. In addition, some largely used XRPD quantitative techniques such as the external standard and RIR (reference intensity ratio) and the influence of the sample loading method are accounted for in an internally consistent comparison among different procedures of analysis.
Effect of silica nanopowder on the properties of wood flour/polymer composite

Low-density polyethylene (LDPE), high-density polyethylene (HDPE), polypropylene (PP), and polyvinyl chloride (PVC) (1:1:1:0.5) were solution blended by using a mixture of solvents consisting of xylene and tetrahydrofuran (THF) (70:30). SiO2 nanoparticles were modified by cetyl trimethyl ammonium bromide (CTAB). Wood polymer composites (WPC) were prepared by using polymer mixture, polyethylene-co-glycidyl methacrylate (PE-co-GMA), wood flour, and modified SiO2. X-ray diffraction (XRD) studies showed that the intensity of the peaks of polymer mixture decreased due to incorporation of SiO2. The dispersion of SiO2 nanoparticles and morphological characteristics were examined by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The interaction between SiO2 nanoparticles, PE-co-GMA, polymer mixture, and wood was studied by Fourier transform infrared spectroscopy (FTIR). Tensile and flexural properties of the composites improved significantly due to the incorporation of SiO2 nanoparticles. Thermal stability, hardness, flame retardancy, and water resistance capacity were also found to enhance. Maximum improvement in properties was observed by the inclusion of 3 phr modified SiO2 in WPC. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers
Air Entrainment During Flame Aerosol Synthesis of Nanoparticles

Enclosed flames typically produce substantially larger particles than open flames under identical reactant flows and composition. The enclosure hinders air entrainment to the flame and reduces heat losses by radiation and convection, facilitating particle coagulation and coalescence. Here the effect of natural air entrainment on flame aerosol synthesis is investigated by lifting off the enclosing tube from the burner surface and utilizing tracer gas (Ne) analysis after calibration with forced air entrainment. That way the effect of air entrainment on product primary particle diameter and mobility size distribution dynamics is investigated by microscopy, scanning mobility particle sizing, and N2 adsorption, while temperature is measured by Fourier-transform infrared spectroscopy. So air entrainment during flame spray pyrolysis is examined here for its versatility in scalable manufacture of an array of material compositions, while copper oxide (CuO) is used for its electro-chemical applications (e.g., battery electrodes). It is shown that natural air entrainment facilitates rapid gas-to-particle conversion and high process yields by minimizing vortex recirculation and particle deposition on the enclosing tube walls and burner surface. For example, the average primary particle diameter of CuO can be controlled from 42 to 10 nm and the yield from 40 to 90% by gradually lifting off the enclosing tube, resulting in up to 250 L/min natural air entrainment at the present CuO synthesis conditions. Copyright 2014 American Association for Aerosol Research
Thermodynamic stability and negative thermal expansion of hexagonal and cubic ices

The free energies of two low pressure ice forms are calculated over a wide range of temperatures in order to explain relative stability and their negative thermal expansivities in the low temperature regime. One-hundred proton-disordered configurations for hexagonal and cubic ices are generated. The Helmholtz free energy is approximated to a sum of the minimum potential energy, the harmonic free energy and the configurational entropy arising from the disordered nature of protons. The Gibbs free energy at a given temperature is minimized with respect to the volume of the system. This enables us to evaluate the thermal expansivity at a fixed temperature and pressure from only intermolecular interaction potentials. The negative thermal expansivity of ices in low temperature is successfully reproduced. This arises mainly from the bending motion of hydrogen bonded molecules.
Solvation of Cu2+ in Water and Ammonia. Insight from Static and Dynamical Density Functional Theory

We have studied the solvation of divalent copper by water and ammonia through the optimization of the structures of [Cu(H2O)n]2+ and [Cu(NH3)n]2+, n = 3−8, by static density functional theory and ab initio molecular dynamics simulations. We found that as the number of solvent molecules increases to more than four, the additional ligands prefer to be hydrogen-bonded to the planar tetragonal primary hydration shell of [Cu(solvent)4]2+ instead of filling the vacant axial position. The energetic preference of water is about 20−35 kJ/mol for the hydrogen bond compared to the axial position, whereas ammonia shows preference of only a few kJ/mol. Dynamical simulations were successful in reaching the lowest energy conformations. Especially remarkable is the dynamics of [Cu(H2O)8]2+, which has evolved from an eight-coordinate structure to a planar structure with four primary and four secondary solvent molecules in a short 10 ps simulation. Both [Cu(H2O)8]2+ and [Cu(NH3)8]2+ prefer a quasi-planar structure with a t.