Miracle-dz/UniFAR-FTUs huggingface dataset:
Excess Volumes and Excess Isentropic Compressibility of Binary Mixtures of N, N-Dimethyl for mamide with n-Alcohols at 303.15 K

Abstract Excess volumes and isentropic compressibility's for binary liquid mixtures of N,N-d-dimethyl-formamide with methanol, 1-propanol, 1-butanol, 1-pentanol, 1-hexanol and 1-heptanol have been measured at 303.15 K. Both the excess properties are negative in the systems with lower alcohols and become positive with increase in alkanet chain length of alcohols. The sign and magnitude of excess functions have been discussed in terms of the combination of the effects due to difference in size, shape and intermolecular interaction between unlike components.
El cultivo de alfalfa utilizando agua de perforación, agua residual urbana y precipitaciones

The objective of this study was to analyse the production of alfalfa biomass, the efficiency of water use and the nutritional value of forage, inside an irrigation structure of an experimental facility that uses treated urban wastewater, artesian well water and rainfall, at the campus of the Universidad National de Rio Cuarto (Cordoba-Argentina). The irrigation treatment had a positive effect on the production of biomass of alfalfa. On an average 24% increase in production was observed when compared to dry-land farming. Regarding the quality of the irrigation water, statistical differences in production were observed, the irrigation with urban wastewater produced 19% more than that of well water. The efficiency of the water use by the crop increased when the irrigation was done using urban wastewater. The alfalfa irrigated with wastewater surpasses the nutritional values of the crop in normal field conditions: 39% more proteins, 14% more digestibility and equal percentage of metabolic energy. It is concluded that the urban wastewater represents possible water source for the alfalfa crop.
Theoretical prediction of the potential curves for the lowest‐lying states of the isovalent diatomics CN+, Si2, SiC, CP+, and SiN+ using the abinitio MRD‐CI method

Large‐scale CI calculations are reported for the potential curves of the isovalent series of diatomic systems CN+, Si2, SiC, CP+, and SiN+ in their lowest electronic states. The standard AO basis sets employed are of double zeta plus polarization quality and the CI method used is of the multireference double‐excitation (MRD‐CI) variety including individualized configuration selection and energy extrapolation. By including up to 17 reference species to generate the MRD‐CI spaces (of orders up to 150 000) and by supplementing the AO basis with f functions it is found that the ground state of CN+ is the π4 1Σ+ species (as in isovalent C2) falling 0.1 eV below the σπ3 3Π state. This result is in significant disagreement with earlier theoretical predictions on this point, which have generally tended to place the 3Π state at least 0.3 eV below 1Σ+. The importance of using more than a single reference configuration in the CI calculations is underscored in this example. For Si2 a similar nearly isoenergetic relat.
The use of biodiesel as a green polymerization solvent at elevated temperatures

BACKGROUND: Many important polymers are produced via solution polymerization. The solvent maintains a low viscosity, which provides many practical advantages related to heat transfer, mixing and material handling. Despite these advantages, commonly used solvents often present health and environmental problems. In an effort to replace these toxic solvents, a ‘green’ polymerization solvent, namely canola-based FAME (fatty acid methyl ester or biodiesel), was used for solution polymerizations at an elevated temperature. RESULTS: Homopolymerizations of methyl methacrylate, styrene, butyl acrylate and vinyl acetate in FAME were studied at different solvent concentrations at 120 °C. Chain transfer to solvent rate constants (Cfs) were obtained for each polymer system and Arrhenius parameters for Cfs, i.e. Ea and A, were also calculated. These new solvent data were employed in a polymerization simulator to predict rate of polymerization and number- and weight-average molecular weights for these commercially important systems. Model predictions showed reasonable agreement with experimental data. CONCLUSION: FAME fulfills the demands as a polymerization solvent. From an ecological perspective, FAME provides an environmentally friendly alternative to common solvents. From an industrial perspective, using FAME as a high-boiling polymerization solvent can increase productivity by enabling polymerizations at elevated temperatures. Copyright © 2008 Society of Chemical Industry
Assessment of mineral nutrition of cork oak through foliar analysis

Abstract The changes in the mineral nutrient content of the leaves of an evergreen species, the cork oak (Quercus suber L.), were investigated to assess the possibilities of a diagnosis of the mineral nutrition of this forest species. A comprehensive pattern of change in the leaf contents of N, P, and Ca was then put forward from the data obtained. Among the time intervals that are most favorable to analyses, the end of the vegetative rest period, in January, was investigated more precisely. The variation coefficients of the leaf contents measured tree by tree were determined for a number of nutrients (N, P, K, Ca, Mg, Fe, Cu, Zn, Mn, B, Al, and Cl). The foliar analyses carried out on 7‐ to 10‐month old leaves in stands submitted to various forest management practices led to the characterization of significant differences in P, Ca and Mn leaf contents in relation to the treatments applied.
Admittance spectroscopy of impurity levels in Schottky barriers

Measurements of the complex admittance of Schottky‐barrier diodes as a function of temperature provide a spectroscopy of deep trapping levels. The measurement conditions are usually close to thermal equilibrium, thus assuring the validity of equilibrium occupation probabilities. An exact (i.e., to arbitrary accuracy) solution for the junction admittance is given. The problem is reduced to solution of a simple initial‐value problem, the final integration being carried out by computer. It is shown that the dispersion in capacitance due to slow trapping levels can lead to serious errors in estimates of junction doping concentrations and barrier height determinations. Examples are given for p‐type ZnTe where Shockley‐Read‐Hall (SRH) centers are dominant and for n‐type CdTe and Cd1−xZnTe where double‐acceptor centers are dominant. For junctions formed on CdTe : Ga it is shown that one of the steps in capacitance observed in a thermally stimulated capacitance survey is actually a high‐frequency response step an.
Second virial coefficient in one dimension as a function of asymptotic quantities

A result from Dodd and Gibbs (J. Math. Phys., 15, 41 (1974)) for the second virial coefficient of particles in one dimension, subject to delta-function interactions, has been obtained by direct integration of the wave functions. It is shown that this result can be obtained from a phase shift formalism, if one also includes the contribution of oscillating terms. The result is important in work to follow, for the third virial coefficient, for which a similar formalism is being developed. We examine a number of fine points in the quantum mechanical formalisms.
Spontaneous chirality in an octupolar discotic crystal

In the quest for organic second-order nonlinear materials, self-assembled structures based on octupolar molecules have shown to be promising candidates. The presented work focuses on an octupolar substituted 1,3,5-trisalkynylbenzene that forms crystals that show significant second-harmonic generation (SHG). Continuous polarization SHG measurements were performed to elucidate the tensorial nature of this response. Unfortunately the model at hand was unable to fit the polarization patterns due to depolarization of the second harmonic beam caused by multiple scattering in the sample. Although the chromophore is clearly achiral, these patterns revealed a different response for left and right circularly polarized light, also known as SHG circular difference. This implies that these molecules spontaneously assemble in chiral superstructures. These surprising results were confirmed by circular dichroism spectroscopy, revealing a monosignate CD band that must be attributed to a supramolecular chiral organization.
Crystal engineering of molecular NLO materials

The development of functional molecular materials with desirable physical properties such as nonlinear optical, (ferro-)electric, (ferro-)magnetic and (photo-)conducting properties for practical applications has become one of the fastgrowing multi-disciplinary research areas. In addition to the specific functionalities that a molecule needs to possess, the constituent molecules usually require a certain welldefined molecular orientation and arrangement in the solid state so that the corresponding physical properties can be used in the bulk. Examples of this are that the charge transfer complexes in organic conducting materials are required to arrange either in segregated stacks or in planar sheets in order to exhibit the anisotropic electrical conductivity in the crystalline state. "] On the other hand, for the second-order nonlinear optical materials, the constituent donor-acceptor chromophores need to crystallize non-centrosymmetrically in order to exhibit the desirable second-order effects such as second harmonic generation (SHG). Furthermore, to be an efficient second-order nonlinear optical material, the chromophoric orientation needs to be optimized so that the nonlinear susceptibilities are maximized in the bulk. For the linear electro-optic effect, the ideal orientation of the dipolar chromophores is in a parallel arrangement. For second harmonic generation and optical parametric oscillation, phase matching is necessary; otherwise, such materials will have no practical use. The optimal angle between the charge transfer axis of a dipolar chromophore and the polar direction of a crystal for non-critical phase matching is about 5.5" for the most favorable point groups. ['I Another attractive application of these highly efficient acentric crystals is their use for the enhancement of large third-order nonlinearities due to cascaded second-order n~nlinearities. '~. ~] This could provide a breakthrough for ultra-fast low-power all-optical switching.
OH radical generation by atmospheric pressure pulsed discharge plasma and its quantitative analysis by monitoring CO oxidation

OH radicals play a very important role in non-thermal plasma chemical reactions for decomposition of gaseous pollutants or synthesis of methanol from methane, etc. In this paper, the CO oxidation monitoring method, which has been used in atmospheric chemistry, was examined to measure the concentration of OH radicals produced by a pulsed discharge plasma. The concentration of OH radicals in the discharge plasma of H2O/Ar mixture gas was estimated by measuring the amount of CO2 produced through oxidation of CO by OH radicals. The experimental results and the calculated results showed that it is possible to measure OH radicals using this simple method. In this experimental work, the maximum concentration of OH radicals produced by the pulsed discharge plasma of H2O/Ar was measured to be 9.4×1014 molecules cm−3 pulse−1. Within the temperature range investigated in this study (50–150°C), the formation of OH radicals increased with increase in the specific input energy (discharge energy dissipated in unit volume of the gas; SIE) value and the content of H2O; in contrast, it decreased with increase in the gas temperature.
Methane oxidation kinetics differ in European beech and Norway spruce soils

Coniferous forest soils often consume less of the greenhouse gas methane (CH4) than deciduous forest soils. The reasons for this phenomenon have not been resolved. It might be caused by differences in the diffusive flux of CH4 through the organic layer, pH or different concentrations of potentially inhibitory compounds. Soil samples were investigated from three adjacent European beech (Fagus sylvatica) and Norway spruce (Picea abies) stands in Germany. Maximal CH4 oxidation velocities (Vmax(app)) and Michaelis Menten constants (KM(app)), retrieved from intact soil cores at constant CH4 concentrations, temperature and matric potential, were twice as great in beech as in spruce soils. Also atmospheric CH4 oxidation rates measured in homogenized soil samples displayed the same trend. Greatest atmospheric CH4 oxidation rates were detected in the Oa horizon or in the upper 5 cm of the mineral soil. In contrast to the beech soils, the Oa horizon of the spruce soils consumed no CH4. A differential effect due to divergent diffusive flux through the litter layer was not found. pH and ammonium concentration were similar in samples from both forest soil types. Ethylene accumulation in all soils was negligible under oxic conditions. These collective results suggest that the different atmospheric CH4 uptake by beech and spruce soils is caused by different CH4 oxidizing capacities of methanotrophic communities in the Oa horizon and top mineral soil.
Nonsingularity of Naphthalene Sorption in Soil

Realistic models for transport of organic chemicals in soil require accurate predictions of the adsorption-desorption kinetics. In this study, a physically based two-compartment one-rate (TCOR) sorption model was evaluated by comparison of model simulations to measured adsorption-desorption isotherms of naphthalene (C 10 H 8 ) for five different soils on a short-term (48 h) and a longer-term (504 h) time scale. Two soils exhibited minor adsorption-desorption nonsingularity (labeled Type I soils), two soils pronounced nonsingularity (Type II soils), and the fifth soil pronounced nonsingularity only on the longer-term time scale (Type I/II soil). The TCOR sorption model fitted, measured adsorption-desorption isotherms well on both short-term and longer-term time scales. However, the TCOR sorption model parameters varied for each soil between short-term and longer-term data, especially for Type II soils. The uniqueness of the TCOR model fit was tested by varying the number of desorption data used, resulting in markedly changed parameter values. The TCOR sorption model was evaluated by using model parameters obtained from short-term data to predict longer-term sorption results. The TCOR prediction of adsorption-desorption behavior was good for Type I soils, satisfactory for the Type I/II soil, and poor for Type II soils. Model parameters obtained from short-term and longer-term experiments were used to predict independently measured adsorption kinetics, showing decreasing prediction accuracy with increasing sorption nonsingularity. The results imply that the TCOR sorption model description of the diffusion process at the grain scale is oversimplified, and that sorption nonsingularity is not well explained by kinetic factors alone.
Molecular dynamics simulations of a sodium octanoate micelle in aqueous solution

Molecular dynamics simulations of a sodium octanoate micelle in aqueous solution are reported. Simple analytical expressions have been used for the interatomic interactions, including a Lennard‐Jones term and a Coulombic interaction betwen partial charges on each site. Two different interaction potentials have been investigated, and amphiphilic aggregation is shown to depend strongly on the electrostatic properties of the water model. For both potentials the micelle shows a broad transition region between the aqueous and hydrocarbon regions. The hydration of different carbon atoms in the chain is largest for the carboxylic atom, then decreases along the chain, reaching a minimum and then increases again at the end of the chain. The micellar translational and rotational diffusion are too fast, probably due to deficiencies in the water model. The rotational diffusion of the entire micelle is found to be an order of magnitude slower than that of the monomers. Reorientational time correlation functions and or.
The Effect of Nitric Acid Oxidization Treatment on the Interface of Carbon Fiber-Reinforced Thermoplastic Polystyrene Composite

The quality of interfacial interaction is dictated by the surface chemistry of the carbon fibers and the composition of the matrix. The composition of polystyrene was modified by the addition of maleic anhydride (MAH) grafted polystyrene. The surface properties of the various matrix formulations were characterised by contact angle. Carbon fibers were modified by oxidation in nitric acid. The surface composition of the carbon fibers was characterized. The interaction between modified polystyrene and the carbon fibers was studied by single fiber pull-out tests. The best adhesion behavior was achieved between polystyrene containing grafted MAH and nitric acid oxidation carbon fibers. The addition of MAH-grafted polystyrene to the unmodified polystyrene caused the interfacial shear strength to increase. The apparent interfacial shear strength of this fiber-matrix combination allowed for the utilisation of 100% of the yield tensile strength of polystyrene.
Analysis of cold temperature effect on stress wave velocity in green wood

Abstract The objective of this study was to investigate the effect of temperature on stress wave velocity (SWV) in green wood below zero degress centigrade (0°C). Both field and laboratory tests were conducted on standing Korean pine trees and small wood samples to study the effects of low temperature at various moisture content (MC) on SWV. As expected, SWV in wood increased with decreasing temperature. However, near 0°C, the SWV increment was not linear but showed disproportional high increments at MCs above 50%. To explain this phenomenon, differential scanning calorimeter (DSC) measurements were performed at various MCs and temperatures, i.e., the interrelation between the state of water aggregation and SWV was analyzed. The explanation of the irregular behavior of SWV as a function of temperature is straightforward: free water and a small portion of bound water in green wood are transformed from water to ice below zero degrees (0°C) centigrade. Thus the disproportional high SWV increment below 0°C reflects the aggregation change of water because the SWV in ice is higher than that in liquid water.
Carbon black-filled poly(ethylene-co-alkyl acrylate) composites: Calorimetric studies

The calorimetric characteristics of carbon black (CB)/poly(ethylene-co-alkyl acrylate) composites depend on both the CB and acrylate contents. An increase of the acrylate content in the pure copolymers tends to decrease all the crystalline characteristics: Tc,n, the nonisothermal crystallization temperature; Tm, the melting temperature, and ΔHm, the melting enthalpy. CB modifies the crystallization kinetics of poly(ethylene-co-ethyl acrylate) (EEA) alone and in blends with poly(ethylene-co-24% w/w methyl acrylate) (24EMA) and poly(ethylene-co-35% w/w methyl acrylate) (35EMA). In the presence of CB, Tc,n, the nonisothermal crystallization temperature of EEA, increases and t1/2, the half-crystallization time, decreases for a given isothermal crystallization temperature, Tc,i. The thermograms obtained during the melting of EEA after isothermal crystallization show multiple endotherms, suggesting that crystalline-phase segregation has occurred. The existence of different crystalline species can be explained by the presence of fractions of different acrylate content in the copolymers as shown by SEC. Therefore, CB does not seem to have much effect on the subsequent melting temperature of EEA, Tm,s. CB also induces a lower melting enthalpy, Δ Hm, in the blends. This decrease of ΔHm appears to be constant whatever the compound, but when reported to the melting enthalpy of the polymer without CB, δΔHm/ΔHm increases with the acrylate content. A slight increase of the amorphous phase stiffness after CB introduction is noticed: The Tg of EEA/24EMA and EEA/35EMA blends increases by several degrees. Therefore, plotting ΔHm versus ΔCp shows that for the same ΔHm the ΔCp is lower in CB-filled samples, suggesting there is some kind of rigid amorphous phase not contributing to the glass transition. We propose to explain the CB activity during the crystallization process by the existence of molecular interactions between CB and acrylate groups rather than by a pure nucleating effect. Thus, the increase of Tc,n and the decrease of ΔHm could be explained by the fact that CB separates acrylate-rich chains from the crystallization medium, accelerating the crystallization of the acrylate-poor chains. During such a crystallization process, CB may be preferentially localized in the more polar amorphous phase and scattered between the two crystalline phases of EEA and EXA. These blends of poly(ethylene-co-alkyl acrylate) copolymers with CB provide interesting materials with adjustable properties depending on the acrylate and CB contents and on the thermomechanical treatments. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 79: 779–793, 2001
Autotrophic Ammonia Removal Processes: Ecology to Technology

The last decade has witnessed rapid spur in technoeconomic autotrophic ammonia removal technologies for wastewater treatment such as SHARON, ANAMMOX, SNAD, CANON, OLAND, DEMON, and BABE. These technologies have the potential to remove high concentrations of ammonia in wastewaters. Despite their high removal efficiency, the quantum of full-scale applications of these processes is far from trivial. The issues that create a bottleneck in the application of such processes are often overlooked. Recent discoveries made in marine anaerobic niches provide some clues for resolving the problems faced while implementing these processes commercially. Some thoughts on the future research areas are also presented.
Stereochemistry of copper(I) complexes. Part II. The molecular structure of the 3 : 2 reaction product between copper iodide and bis(diphenylphosphino)methane: di-µ-[bis(diphenylphosphino)methane]-µ-iodo-di-µ3-iodo-triangulo-tricopper(I)–0.5 dichloromethane

The crystal structure of the title compound has been determined from three-dimensional X-ray data by the heavy-atom method and refined by anisotropic block-diagonal least-squares to R 0.056 for 3 504 independent reflections. Crystals are monoclinic, space group P21/c, with cell parameters a= 13.266(8), b= 22.667(9), c= 20.887(8)A, β= 121.94(7)°, Z= 4. The structure consists of a triangle of distorted tetrahedral copper atoms connected by a bridge of iodine atoms and the dpm ligand. Values of Cu–P and Cu–I bond lengths and the geometry of the halogen bridges are discussed on the basis of the structural results of similar compounds.
Radiation-induced grafting of styrene onto poly(tetrafluoroethylene) (PTFE) films. I. Effect of grafting conditions and properties of the grafted films

Radiation-induced grafting of styrene onto poly(tetrafluoroethylene) (PTFE) films was studied by a simultaneous irradiation technique. Grafting was carried out using g-radiation from a 60 Co source at dose rates of 1.32-15.0 kGy h ˇ1 at room temperature. The effects of type of diluent, dose rate, irradiation dose, and the initial monomer concentration in the grafting solution on the degree of grafting were investigated. The degree of grafting was found to be strongly dependent upon the grafting conditions. The dependence of the initial rate of grafting on the dose rate and the initial monomer concentration in the grafting solution was found to be in the order of 0.6 and 1.7, respectively. The chemical structure and the crystallinity of the grafted PTFE films were studied by means of Fourier- transform infrared, (FTIR), electron spectroscopy for chemical analysis (ESCA) and X-ray diffractometry (XRD). # 2000 Society of Chemical Industry