Miracle-dz/UniFAR-FTUs huggingface dataset:
Determination of Internally Consistent Thermodynamic Data from Phase Equilibrium Experiments

A technique has been devised for evaluating the internal consistency of experimental data in any particular chemical system. The sequence of steps is: (1) Each experimental point is expressed as an inequality in terms of the free energy change of the reaction to which it applies. For example, in a solid-solid reaction, the sum $${\Delta}G_{R}^{\circ} - (T - 298) {\Delta}S_{R}^{\circ} + (p - 1){\Delta}V_{R}^{\circ}$$ is greater than zero if the reactants are stable, or less than zero if the products are stable. (2) Linear relationships between the standard state free energies and entropies of different reactions are expressed as linear equations. (3) The resulting system of inequalities and equations is solved by the techniques of linear programming, maximizing and minimizing the standard state free energy and entropy of each reaction in turn. (4) If the experimental data are internally consistent, the limits of each of the thermochemical constants for each reaction are obtained. If the experiments are inconsistent, the offending experiments may be identified. Application of the technique to the results of experimental investigations of 18 reactions in the system CaO-Al₂O₃-SiO₂-H₂O-CO₂ indicates that the data tested are all consistent. The procedure may be extended to determine thermodynamic properties of individual phases.
Application of UV-Vis and resonance Raman spectroscopy to study bleaching and photoyellowing of thermomechanical pulps

Abstract The chemistry of thermomechanical pulp bleaching and brightness reversion was studied. First, UV-Vis reflectance spectroscopy was used to obtain information on the reactive structures in pulp. Based on these data, a Raman excitation wavelength was chosen close to the absorption bands of the chromophores formed to take advantage of the resonance enhancement (resonance Raman spectroscopy). Fluorescence was rejected with a picosecond Kerr gate. The results revealed that coniferyl aldehyde structures were partly removed by alkaline peroxide bleaching and these structures were further degraded during light exposure. However, this reaction was obviously not responsible for chromophore formation in the pulp. On the other hand, based on the resonance Raman spectra, formation of quinonoid structures, possibly para-quinones, was a more prominent explanation for the brightness reversion.
Determination of uranium isotopic ratio (235U/238U) using extractive electrospray ionization tandem mass spectrometry

Extractive electrospray ionization (EESI) mass spectrometry (MS), a typical MS platform for detection of organic compounds, has been used for quantitative detection of uranium isotopic ratio (235U/238U) in uranyl nitrate solution samples, which were prepared from various samples including natural water samples, uranium ore samples and soil samples using nitric acid. This method requires minimal sample pretreatment and no high resolution instruments. The typical time for analysis of a single liquid sample was about 5 min since the prepared sample solutions were directly infused into the EESI source without separation or preconcentration. The relative errors for uranium isotope measurements were in the range of 0.21%–0.25% and the corresponding relative standard deviation (RSD) values were 1.54%–1.81% for the ore samples. The results obtained by EESI-MS for direct analysis of 5 soil samples were validated by using ICP-MS. These findings confirmed that EESI-MS can be employed for quantitative measurement inorganic compounds present in a complex matrix. The fast detection of uranium isotopes shows potential applications of EESI-MS in nuclear research laboratories and the nuclear energy industry.
Spectral Studies on the Supramolecular Assembly of 1H2NA: β-CD Complex and its Analytical Application as Chemosensor for the Selective Sensing of Cr3+

The supramolecular assembly of 1-hydroxy-2-naphthoic acid (1H2NA) with β-CD has been investigated by UV-visible and fluorescence spectroscopy. The stoichiometry and binding constant of inclusion complex was estimated using the Benesi–Hildebrand plot derived from the excitation and emission spectral data at 303 K. The estimated ΔG indicated that the inclusion is an exergonic and spontaneous process. The mechanism of complexation was investigated and confirmed by FTIR spectroscopy, semiempirical, and molecular docking studies. During the investigation of complexation, significant increase in the fluorescence intensity for the variation of β-CD concentration was observed. Based on this phenomena the chemosensory power of 1H2NA: β-CD complex was investigated thoroughly for various metal ions and we found the emission of complex showed a drastic increase in the intensity for Cr3+ and the fluorescence intensity enhanced to >50 out of all the metal ions studied. The order of change of fluorescence intensities found to be, Cr3+ > Se4+ > Ni2+ > K+ > Th4+ > Ca2+, Ti4+ > Al3+ > Ce4+ > Mg2+ > Ag+ > Na+ > Fe3+. Selectivity and sensitivity analysis showed remarkable selectivity in sensing Cr3+ with the LOD of 0.3 × 10−4 M and LOQ of 0.9 × 10−4 M.
Temperature-dependent activation energy and variable range hopping in semi-insulating GaAs

We measured resistivity in the range of 30–390 K on four semi-insulating low-temperature grown molecular-beam epitaxy GaAs samples. The growth temperature range was from 215 °C to 315 °C. Arrhenius fittings with T−1 and hopping fitting with T−1/4 do not permit us the definition of the temperature ranges controlled by band and hopping conduction, respectively. This leads to major errors in the calculation of both activation energies and hopping parameters. We have used the differential activation energy in order to clearly identify the temperature range for the different transport mechanisms. Hopping dominates at low temperatures and band conduction at high temperatures. In-between, a mixed conduction regime is observed. We introduce a criterion to clearly define the temperature range of hopping, band and mixed conduction. The lower temperature at which mixed conduction is identified decreases for samples with increasing growth temperature. Only the sample grown at 215 °C presents both forms of hopping conduction before entering the mixed conduction regime. Hopping parameters were obtained from the fittings of the differential activation energy and the values are in good agreement with the usual method of calculating them if the correct temperature range is used.
Mixed-Salt Effects on the Ionic Conductivity of Lithium-Doped PEO-Containing Block Copolymers

We demonstrate a simple, yet effective, mixed-salt method to increase the room temperature ionic conductivity of lithium-doped block copolymer electrolyte membranes by suppressing the crystalline phases in the conducting block. We examined a mixed-salt system of LiClO4 and LiN(SO2CF3)2 (LiTFSI) doped into a lamellae-forming poly(styrene-b-ethylene oxide) (PS–PEO) diblock copolymer. The domain spacings, morphologies, thermal behavior, and crystalline phases of salt-doped PS–PEO samples were characterized, and the ionic conductivities of block copolymer electrolytes were obtained through ac impedance measurements. Comparing the ionic conductivity profiles of salt-doped PS–PEO samples at different mixed-salt ratios and total salt concentrations, we found that the ionic conductivity at room temperature can be improved by more than an order of magnitude when coinhibition of crystallite growth is promoted by the concerted behavior of the PEO:LiClO4 and PEO:LiTFSI phases. Additionally, we examined the influence .
A mixed quantum mechanics/molecular mechanics (QM/MM) method for large‐scale modeling of chemistry in protein environments

A QM–MM method, using our previously developed frozen orbital QM–MM interface methodolgy, is presented as a general, accurate, and computationally efficient model for studying chemical problems in a protein environment. The method, its parametrization, and a preliminary application to modeling cytochrome P‐450 chemistry are presented. © 2000 John Wiley & Sons, Inc. J Comput Chem 21: 1442–1457, 2000
Composting Unamended Chicken Manure

Normally, manures are composted with amendments. However, a large commercial egg producer in Ohio is composting unamended chicken manure. Studies were done to characterize this composting, both in situ and in pilot-scale vessels. While overly wet material can hamper initial operation, the general progression dries the material and produces a granular output that is below 20 percent (wet basis) moisture and can be bagged and/or sold commercially. A rewetting study on the present output material indicated it is incompletely composted. Further studies of initial and partially composted materials characterized heating, reaction rates, oxygen demand and ammonia output during composting. Very high ammonia production relative to more conventional manure composting operations is the most important result from this work. Retention and recapture of ammonia is the focus of research to be reported elsewhere.
The Adsorption of Cr(VI) on Sulphuric Acid-Treated Wheat Bran

Wheat bran, a by-product of wheat milling industries, was converted into a cheap and efficient material by treating with sulphuric acid and used for the adsorption of Cr(VI) from aqueous solution. Effects of various parameters such as initial pH of solution, contact time, initial Cr(VI) concentration and temperature were studied. The sulphuric acid-treated wheat bran (STWB) gave the highest adsorption efficiency at pH 1.5. The equilibrium data were fitted better to Langmuir isotherm model compared to Freundlich model at all the temperatures studied. The adsorption capacity increased from 91 to 133 mg g-1 with an increase in temperature from 20 °C to 50 °C. The adsorption process was found to be endothermic and Langmuir isotherm data were evaluated to determine the thermodynamic parameters for the process. Thermodynamic parameters showed that the process was feasible. The results indicated that the chromium removal process by STWB followed first-order rate expression and adsorption rate constants increased with increasing temperature.
Degradation of Pesticides in Subsurface Soils, Unsaturated Zone—a Review Of Methods and Results

Abstract Methods and results from degradation studies in subsoils, unsaturated zone, were reviewed for mecoprop, 2,4-D, atrazine, alachlor, aldicarb, carbofuran, linuron, oxamyl, methomyl, MCPA, dichlorprop, monochlorprop, dichlorphenol, TCA, parathion, metribuzin, metolachlor and fenamiphos. Most of the investigations were laboratory studies where small soil samples were sieved and pesticides were added in concentrations from 0.5-5 μg. g−1. A few of the studies mentioned the importance of working with undisturbed samples; another few studies used isotope-labelled pesticides which made it possible to work with concentrations as low as 0.02 μg. g−1. Subsoil samples were characterized according to factors as microbial activity, soil temperature, water content, oxygen content, concentration of pesticide, pretreatment of the soil and soil type, factors considered to have influence on degradation of pesticides. Chemical hydrolysis was considered to be the most dominant pathway in the degradation of aldicarb in s.
Comparison of arsenic and phosphorus diffusion behavior in silicon-germanium alloys

The diffusion behavior of ion-implanted arsenic and phosphorus in relaxed Si0.8Ge0. 2 has been investigated. Under equilibrium, extrinsic conditions, both dopants are observed to diffuse faster in SiGe than in Si. Simulations of the measured profiles suggest that the ratio of the effective diffusivity in Si0.8Ge0. 2 compared to that in Si is roughly seven for arsenic, and roughly two for phosphorus. Under transient diffusion conditions, the arsenic diffusivity in SiGe is retarded, and the magnitude of the diffusion is roughly the same as that in Si. This result suggests that it is possible to optimize the diffusion conditions to achieve n+ source/drain junctions that are as shallow in SiGe as in Si.
Promotive effects of phosphorus on crop productivity, enzyme activities, anthraquinone and sennoside content in Cassia tora L. – a medicinal herb

Abstract The plants of Cassia tora L. were grown in pots containing soil, supplied with five levels of phosphorus: 0 (Control), 0.1, 0.2, 0.3 and 0.4 g P per kg soil. The fresh and dry weights, number of leaves and leaf-area per plant were recorded. The leaves were analyzed for inorganic elements, such as nitrogen, phosphorus, potassium and calcium. Physiological and biochemical attributes including chlorophyll and carotenoid content, nitrate reductase activity, carbonic anhydrase activity, net photosynthetic rate, stomatal conductance and transpiration rate were determined. Yield attributes including number of pods, number of seeds per pod, 100-seed weight, and seed-yield per plant were recorded. In addition, protein, total anthraquinone glycosides (in seeds) and total sennoside content (in pods) were also estimated. The results showed that phosphorus at the level of 0.3 g per kg soil proved optimum and significantly enhanced most of the attributes studied.
Spin ordering in three-dimensional crystals with strong competing exchange interactions

In this paper we discuss magnetic ordering in three-dimensional crystals in which Heisenberg exchange interactions appear to dominate. Particular emphasis is placed on systems with strong competing exchange interactions, called frustrated spin systems. In the absence of such competition, one finds collinear spin ordering. However, strong competing interactions lead to non-collinear structures, often spirals and many variations thereof. The problem of understanding the origin and physical properties of such spin states within the classical Heisenberg model has been intensively addressed by a large community of researchers over the last 2–3 decades. The study of such problems actually began about five decades ago, and led to a large body of literature that has been overlooked in the publications of the last 2–3 decades (with two very recent exceptions). The early work established important fundamental concepts, including an unconventional theoretical approach, the generalized Luttinger–Tisza method and the idea of forced degeneracy. This resulted in the spin state called a ferrimagnetic spiral (FS), which enabled understanding of puzzling neutron diffraction data, plus NMR and ESR measurements, on the spinels XCr2O4, X = Mn, Co. Additional new aspects of this magnetic ordering have been uncovered in two very recent experimental works, indicating a partial spin-liquid-like behaviour and production of ferroelectricity by the pure spiral component of the FS. This exciting relevance of the early work to these modern results and the general lack of awareness of the early work has provided a source of motivation for this review, which covers that early body of work, both theoretical and experimental, and which also connects to the recent studies. A thorough discussion of the calculations, and comparison with experiments is presented. It will be seen that fundamental puzzles remain for these systems.
Controlled remodeling of a protein-polysaccharide mixed gel: examples of gelatin-hyaluronic acid mixtures

The gelation of gelatin was studied in the presence of a polysaccharide, hyaluronic acid through rheology measurements. The influence of the polysaccharide on the obtaining of two different gel networks was evaluated: a chemical gel due to enzyme-catalyzed covalent bonding and of a physical gel due to triple helix formation induced by a temperature decrease were both formed in presence of hyaluronic acid. At the liquid state, the rheological properties (shear thinning/viscoelasticity) of the protein-polysaccharide mixture are dictated by the polysaccharide while gelatin modifies viscosity only from a quantitative point of view. Hyaluronic acid does not modify the gelation mechanism of gelatin. It is mainly present in the sol phase of the protein gel where it induces an entangled state which influences the overall viscoelasticity of the system. The impact of the polysaccharide enzymatic degradation on the mechanical properties of the mixture has been evaluated. Hyaluronidase allows a controlled modification of the loss modulus without affecting the storage modulus of gelatin gels. These experiments demonstrate that the mechanical properties of a mixed hydrogel can be a controlled through enzymatic remodeling.
The influence of water vapor on thermal transformation of boehmite

Boehmite compacts and boehmite gels (seeded and unseeded) were annealed at various temperatures in nitrogen and 1 atm water vapor to determine the influence of water vapor on boehmite transformation to new phases, changes in porosity, and morphology. Water vapor was found to accelerate the phase transformations markedly compared to dry N_2 treatment. The catalyzing effect of water vapor may be due to its interactions on grain surfaces and generation of fast diffusion paths, resulting in nucleation and growth of new phases. This result shows that control of the furnace atmosphere is a useful variable in thermally activated processes.
Keeping-Quality Assessment of Pasteurized Milk by Multivariate Analysis of Dynamic Headspace Gas Chromatographic Data. 1. Shelf-Life Prediction by Principal Components Regression

An objective and rapid analytical system for milk shelf-life prediction was established. Volatiles as determined by dynamic headspace capillary gas chromatography (DH-GC), psychrotrophic bacterial counts, and sensory evaluation were monitored during refrigerated storage of pasteurized milk. High correlation between flavor-related shelf life and volatiles indicated that a good proportion of the total variation was explained by the mathematical model obtained by principal component regression (PCR). The resulting standard error of the estimate of less than 2 days was an excellent approximation in shelf-life studies. Using DH-GC, results are available in 20 h (18 h of preliminary incubation +2 h of detection and data processing)
A Comparative Study of Lattice Dynamics of Three- and Two-Dimensional MoS2

This paper presents a comparative study of the lattice dynamics of three-dimensional layered MoS2 and two-dimensional single layer MoS2 based on the density functional theory. A comprehensive analysis of energetics and optimized structure parameters is performed using different methods. It is found that the van der Waals attraction between layers of three-dimensional (3D) layered MoS2 is weak but is essential to hold the layers together with the equilibrium interlayer spacing. Cohesive energy, phonon dispersion curves, and corresponding density of states and related properties, such as Born-effective charges, dielectric constants, Raman and infrared active modes are calculated for 3D layered as well as 2D single layer MoS2 using their optimized structures. These calculated values are compared with the experimental data to reveal interesting dimensionality effects. The absence of a weak interlayer interaction in 2D single layer MoS2 results in the softening of some of Raman active modes.
Cholinesterase inhibitory activity of Morinda lucida

Morinda lucida was found common in recipes given by Traditional Medical Practitioners in South Western Nigeria either as memory enhancer or anti-ageing. The oven dried leaves were extracted with 80% methanol and screened for both acetyl (AChE) and buteryl (BuChE) cholinesterase inhibitory activities. Fractionation of the crude extracts, followed by ethyl acetate bulk extraction, precipitation studies, phytochemical screening and anti-cholinesterase activity of the extracts and fractions are hereby reported. Both the precipitate and supernatant showed different coloured spots with vanillin in H2SO4 and were positive for terpenoids, anthraquinones and flavonoids while negative for alkaloids. The methanolic extract inhibited both AChE (40.15% ± 2.5) and BuChE (34.09% ± 1.93), and the activity resided more in the supernatant of the ethyl acetate fraction (82.35% AChE). This correlates with ethno medical claims and thus provides for the first time, the pharmacological basis for the folkloric use of M. lucida in the management of memory dysfunction in South Western Nigeria. Key words: Morinda lucida, cholinesterase, acetyl (AChE), buteryl (BuChE).
Time‐resolved phenomena in cements, clays and porous rocks

Small-angle neutron scattering (SANS) provides a powerful tool in the non-destructive characterization of statistically representative microstructures in technologically important disordered materials. While qualitative microstructural models must be provided by other methods such as transmission electron microscopy (TEM), SANS quantifies the microstructural parameters and can characterize scale-invariant (fractal) disordered materials such as cements, clays and porous rocks. H2O/D2O contrast-variation methods have proved particularly useful for investigating the accessibility of different parts of the pore structure and in differentiating between pore-volume access (measured by other methods) and pore-surface accessibility (likely to control sorption and leaching processes). This paper describes SANS studies of disordered porous materials, particularly the hydration of cement and the real-time permeation of water in clay minerals. Other microstructural effects are also considered.
Selective Reduction of Nitro Compounds Using CeY Zeolite Under Microwaves

ABSTRACT. Aliphatic and aromatic nitro compounds were selectively reduced to their corresponding amino derivatives in good yieldsusing formic acid and CeY zeolite under monomode reactor. This system is found to be compatible with several sensitive function alities.Beside the recycling result showed it had a long catalyst lifetime and could maintain activity even after being used for 20 cycles. Keywords: CeY zeolite, Monomode reactor, Microwaves, Reduction, Nitro compounds # Paper presented in10th International Electronic Conference on Synthetic Organic Chemistry (ECSOC-10). 1-30 November 2006. http:/www.mdpi. org/ecsoc-10/e004 마이크로웨이브와 CeY Zeolite 를 이용한 니트로화합물의 선택적인 환원반응 # Kapil Arya * and Anshu Dandia † Department of Applied science, D. C. R. University, Murthal, Sonepat, Haryana, India-131039 † Department of Chemistry, University of Rajasthan, Jaipur, India-302004 (접수 2009. 12. 14; 수정 2010. 1. 19; 게재확정 2010. 1. 21) Selective Reduction of Nitro Compounds Using CeY Zeolite Under Microwaves
Sous vide cook‐chill technology

Summary Cook-chilled products are increasingly produced in the catering and food processing industries. It is claimed that the application of vacuum packaging followed by processing in-pack (sous vide technology) improves both shelf life and eating quality, but in doing so presents an increased public health risk. This paper reviews the literature relating to the scientific basis of these claims. It demonstrates that, although they have some theoretical foundation, in practice they are unsubstantiated by research.
Removal of Cr(VI) Ions by Spent Tea and Coffee Dusts : Reduction to Cr(III) and Biosorption

The potential use of spent tea and coffee dusts was investigated for the removal of Cr(VI) from aqueous solution. The removal mechanism was identified as the reduction reaction of Cr(VI) to Cr(III), followed by Cr(III) sorption to the biomass. The phenolic compounds in tea and coffee dusts serve as electron-donor groups for rapid reduction of Cr(VI). The pH edge experiments revealed that Cr(VI) reduction by both tea and coffee dusts was independent of pH whereas reduced Cr(III) adsorption onto biomass was strongly dependent on pH. Isotherm experiments revealed that tea and coffee dusts possess maximum chromium uptakes of 44.9 and 39.0 mg/g, respectively, at pH 4. Among the two isotherm models (Langmuir and Toth), the Toth model better described the chromium biosorption isotherms with high correlation coefficients and low percent error values. A kinetic model based on the redox reaction between Cr(VI) and biomass successfully described the kinetic data. A comparison of these kinetic data with those from Sa.