Miracle-dz/UniFAR-FTUs huggingface dataset:
Variation of Properties of Micrococcus glutamicus Glutamine Synthetase Brought about by Divalent Cations

The optimum pH of glutamine synthetase varied with the type and concentration of divalent cation present: pH 7.0~8.0 with 30mM Mg2+, 6.0~7.0 with 30 mM Mn2+ and 7.0~8.0 with 4mM Mn2+. The activity with 4 mM Mn2+ at pH 7.0~8.0 was almost the same as that with 30 mM Mg2+. Changes in Km values for substrates and in susceptibility to inhibition by certain metabolites were observed when 30 mM Mg2+ was replaced by 4 mM Mn2+. Addition of a small amount of Co2+ greatly stimulated the reaction rate in the presence of a suboptimal level of Mg2+. Optimum pH, Km values for substrates and the inhibitory effect of metabolites were also changed in the mixture of Mg2+ and Co2+. Glutamine synthetase was reactive toward hydroxylamine, methylamine and ethylamine under the standard conditions as well as toward ammonia, and similarly the kinetics of these reactions were altered by divalent cations. The reaction products, γ-glutamyl derivatives, were identified.
Influence of film casting method on block copolymer ordering in thin films

We study the orientation of the cylinder phase of the block copolymer (BCP) poly(styrene-block-methylmethacrylate) (PS-b-PMMA) in thin spun-cast films having a range of film thicknesses and temperatures and compare to our earlier observations on flow-coated films of the same BCP under similar thermodynamic conditions. As in our former measurements on flow-coated films, morphology maps of our spun-cast BCP films reveal distinct ordering regimes where the cylinders orient predominantly perpendicular or parallel to the interface and an ‘intermediate’ regime where these morphologies are mixed. However, we find that the locations of these morphology lines in the temperature–film thickness plane are greatly influenced by the method of film formation. We hypothesize that the slow solvent evaporation of the flow-coated films leads to films having higher residual stresses than spun-cast films because of a relatively inhibited transport of the solvent out of the film during drying, and annealing measurements on both types of cast films provide supporting evidence that the BCP surface morphology change is associated with residual stresses within the films. Contrary to our initial expectations, spun-cast films showed little sensitivity to film casting speed so that residual stress effects associated with the comparatively violent fluid flow conditions of spin-casting appear to be small. Instead, residual stresses arising from slow film evaporation appear to be implicated. Residual stress effects arising during the course of film casting and drying are relevant to other fabrications involving cast polymer films, such as in organic photovoltaic devices where flow-coating or similar industrial film casting method is normally employed for film formation.
Effect of Thermal and Hydro-Catalytic Treatment on the Molecular Chemistry of Narrow Fractions of Athabasca Bitumen Pitch

As much as 50 w/w % of bitumen derived from Athabasca oil sands consists of a residuum that cannot be easily upgraded. A better understanding of the chemistry of this material is the key to achieving optimal yields of commercially useful products. In recent years, the application of supercritical fluid extraction (SCFE) with pentane has been successful in separating the residuum into a number of narrow fractions based on their solubility parameters. An important corollary to this separation is that the molecular weight of each fraction increases with the severity of conditions needed to extract the progressively heavier components in each residua. In combination with advanced characterization techniques this approach has proved to be useful in elucidating the complexity of bitumen chemistry. For the work described here, this approach has been applied to residua from commercial operations at the Syncrude Canada Ltd. plant in Northern Alberta. Base samples included virgin bitumen pitch (P) together with residua from the catalytic hydro-cracking (HC) unit and a once-through fluid-coking (CK) test.The SCFE insoluble, heavy subfractions in the pitch contain core structures, comprising condensed polyaromatic rings, associated with heteroatoms and trace metals. In the catalytic hydro-cracking process the cleavage of C-S side chains and the breakage of inter-unit bonds are the prevailing reactions. A comparison between the lighter, SCFE-soluble fractions from catalytic hydro-cracking and thermal cracking shows the latter to have lower unit molecular weights, higher sulfide contents, and shorter alkyl substituents. The highly aromatic, SCFE-insoluble molecules from the CK process are likely formed from condensation reactions involving various fragments of toluene-soluble and -insoluble material. Condensation reactions between heavy core molecules from the SCFE insolubles in pitch lead to formation of coke. In the catalytic hydro-cracking process single unit, highly aromatic, polar cores from pitch SCFE insolubles appear to remain toluene-soluble and thus constitute most of the HC residue. These coke precursors will be converted to coke, or pseudo-solid species, if subjected to the thermal treatment applied in coking or severe hydro-cracking.
The Surface Tension of Debye‐Hückel Electrolytes

As has been shown by Wagner, the increase of the surface tension caused by the addition of a strong electrolyte to water is mainly due to the repulsion of ions from the surface by the electrostatic image force. Due to the shielding action of the ``ionic atmospheres,'' of radius 1/κ, the image force is appreciable only within distances of the order 1/κ from the surface. The computations become very complicated if, as Wagner did, one attempts to allow for the variation of κ with the depth in accordance with the decreased concentration of ions in the surface layers. Fortunately, a detailed analysis of the problem shows that this refinement may be dispensed with as a first approximation, and that the formulas thus derived will be accurate for not too high concentrations. The same analysis tends to show that Wagner's procedure supplies only a part of the intended correction, so that the results will be applicable only over a slightly wider range of concentrations than the convenient explicit formulas which are.
An NMR study of the oxidative degradation of Cp *ir catalysts for water oxidation: Evidence for a preliminary attack on the quaternary carbon atom of the -C-CH3 moiety

The reaction between H2O2 and two water oxidation catalysts {[Cp*Ir(H2O)3](NO3)2 (1, Cp* = pentamethylcyclopentadienyl) and [Cp*Ir(bzpy)(NO3)] (2, bzpy = 2-benzoylpyridine)} was studied by means of in situ 1D- and 2D-NMR experiments in order to elucidate if catalyst degradation proceeds through the initial functionalization of a quaternary carbon atom (C-attack) or by hydrogen abstraction (H-attack) of the Cp* –C–CH3 moiety. It was shown that 1 underwent double functionalization of the –C–CH3 moiety of Cp* leading to the formation of –C(OR)–CH2OR (R = H or OH) in a strictly analogous manner to that previously observed for the reaction of 1 with Ce4+. On the contrary, two new intermediates associated with the oxidative degradation of 2, which are functionalized only at the quaternary carbon atom(s) of the –C–CH3 moiety [–C(OR)–CH3], were intercepted and characterized by NMR spectroscopy. This indicates that the oxidative degradation of water oxidation catalysts, featuring the –Cp* ancillary ligand, likely starts with preferential C-attack.
Extraction and separation of Cd and Te from cadmium telluride photovoltaic manufacturing scrap

The extraction and separation of cadmium, tellurium, and copper from CdTe PV module scrap was investigated. Several leaching technologies were assessed and the extraction of CdTe from samples of PV modules was optimized for maximum efficiency and minimum cost. A dilute aqueous solution of hydrogen peroxide and sulfuric acid was sufficient to completely leach out cadmium and tellurium from these samples. The same method successfully removed cadmium and tellurium from actual manufacturing scrap; copper was partially extracted. Subsequently, cation‐exchange resins were used to separate cadmium and copper from tellurium. Complete separation (i.e., 99·99%) of Cd from Te was accomplished. The estimated costs of these processes for 10 MW/year processing are about 2 cents per W. Copyright © 2006 John Wiley & Sons, Ltd.
Solubilities and partition coefficients of semi-synthetic antibiotics in water + 1-butanol systems

In this contribution, experimental data are presented on the solubilities and partition coefficients of two semi-synthetic antibiotics (amoxicillin, ampicillin) and their precursors (d-phenylglycine, d-(p-hydroxy)phenylglycine, 6-aminopenicillanic acid) in water + 1-butanol mixtures at a constant temperature of 298 K. In the aqueous phase, the solubility of amoxicillin and ampicillin increases with increasing butanol concentration. For the other components, the solubility decreases. In the organic phase, the solubility of all components is less than that in the aqueous phase. The partition coefficients are approximately constant for all components and less than unity, indicating the higher solubility in the aqueous phase. No influence of the solutes on the phase behavior of the solvent system is detected. The phase behavior is described with the gex model, as suggested by Gude et al. (Gude, M. T. ; Meeuwissen, H. H. J.; Van der Wielen, L. A. M. ; Luyben, K. Ch. A. M. Ind. Eng. Chem. Res. 1996, 35, 4700. Gud.
Potential energy surface of 4-hexyl-4′-cyanobiphenyl (6CB) on graphite surface: a DFT study with van der Waals corrections

The potential energy surface (PES) between a 4-hexyl-4′-cyanobiphenyl (6CB) molecule and a graphite surface was calculated by the first-principles method based on the density functional theory with empirical van der Waals (vdW) corrections. The parameters of the empirical vdW corrections were derived by fitting the PESs for the benzene–methane, benzene dimer and benzene–benzonitrile molecules to high-level ab initio calculations. The obtained potential energy minimum between 6CB and graphite surface for a configuration was ca. − 27.8 kcal/mol. Based on this PES, we determined the force-field parameters between 6CB and graphite surface to be used in classical molecular simulations in the future work.
Effect of Sex on Quality Grade Factors, Physicochemical and Sensory Traits of Longissimus Dorsi in Hanwoo

The effect of cattle sex (cow, bull, and steer) on carcass traits of quality grade factors, physicochemical, and sensory traits of Longissimus Dorsi in Hanwoo was evaluated. Carcass traits of 42,113 heads were collected nation-wide and 257 heads were slaughtered to analyze beef quality. Sex affected significantly marbling score, meat color, fat color, texture, maturity, and quality grade of Hanwoo (p<0.05). Hanwoo steer carcasses had the highest marbling score (5.02), maturity (2.17), and texture (1.31) than those of cows and heifers. Crude fat of steers was higher than that of other cows and bulls. Steers showed the highest L (39.01), Warner-Bratzler shear force (4.03 kg), and water holding capacity (57.08%), however, there was no significant differences between those of cows and bulls. Ultimate pH was shown difference among sex (5.58-5.69), however, the values remained within normal range. In sensory evaluation analyses, sex affected significantly tenderness, juiciness, and flavor (p<0.05). Also, the overall acceptability of steer beef was significantly higher than that of cow and bull beef. These results could be used as fundamental data set for further research activities to elevate Hanwoo beef qualities (p<0.05).
FRACTIONATION AND SORPTION OF INORGANIC PHOSPHORUS IN LOUISIANA CALCAREOUS SOILS

Understanding phosphorus-soil interactions is necessary for environmentally sound management of P. The focus of this study was to characterize the P forms and sorption properties of Louisiana calcareous soils and to investigate relationships between these variables and soil matrix properties. Five mildly calcareous soils (calcium carbonate equivalent [CCE] ranged from 8.9 to 48.3 g/kg) of different geological origins at two depths were evaluated. Soil P forms were sequentially fractionated by sodium bicarbonate, sodium hydroxide, citrate bicarbonate (CB), citrate bicarbonate dithionate (CBD), and HCl. Direct extractable P by Olsen, Bray II, and Mehlich III and ammonium oxalate were also determined. Phosphorus sorption was carried out with a 1:10 soil/solution ratio, and sorption parameters were derived from best-fit Langmuir and Freundlich models to the experimental data. Norwood (Red River alluvium) and Jeanerette (loess-derived) soils were dominated at both depths by HCl-P, presumably stable Ca/Mg phosphates, whereas the Commerce (Mississippi River alluvium) and Mer Rouge (Quachita River alluvium) surface soils also contained large percentages of [NaOH+CB]-P, primarily Fe phosphates. All chemically defined sequential P fractions, except for the HCl-P, were significantly (R2 = 0.42-0.85; P = 0.03-0.0002) correlated with different Fe fractions, especially amorphous and labile Fe. The HCl-P did not correlate with carbonate content or with any other major soil matrix component. Both the Langmuir sorption maximum (b) and the Freundlich distribution coefficient (Kd) were significantly correlated with ammonium oxalate-extractable Al, clay content, and labile Ca (R2 = 0.47-0.79; P = 0.02-0.003). Overall, this study indicates a strong influence of Fe in P chemistry of mildly calcareous soils. It also reveals the importance of labile Ca and surface Al (at exposed edges of aluminosilicate clays) for further P sorption, possibly after available sites of Fe oxides in the calcareous soils are saturated.
Comparative Study on Structural and Ferroelectric Properties of Dual-Site Rare-Earth Ions Substituted Multiferroelectric BiFeO3

We report a comparative study of dual-site rare-earth ions substituted BiFeO3 (BFO) crystal for the first time. BFO, Bi0.95Nd0. 05Fe0.95Nb0. 05O3 (BNFNO), Bi0.95Nd0. 05 Fe0.95Mn0. 05O3 (BNFMO), and Bi0.95La0. 05Fe0.95Nb0. 05O3 (BLFNO) thin films are prepared by sol-gel process. X-ray diffraction and Raman scattering analysis reveals a crystal transformation from rhombohedral to tetragonal upon substitution. The mean grain size decreases from 150 (BFO) to 10 nm (BNFNO) with dual-site substitution. Significant leakage current density enhancement from 1.8×10−3 (BFO) to 6.9×10−7 A/cm2 (BNFNO) at an applied electrical field of 0.1 MV/cm is observed, indicating that dual-site substitution is an effective method to modify BFO material.
Response of bell pepper grown inside plastic houses to nitrogen fertigation

Abstract Two field experiments were conducted for two consecutive seasons inside plastic houses to evaluate bell pepper (Capsicum annuum) response to nitrogen fertigation. Nitrogen fertilizers were applied through irrigation water at rates of zero, 150, 250, and 350 N kg ha‐1. The crops were irrigated in weekly bases with the amount of water equivalent to 80% of the E Pan reading. All treatments were replicated four times in a randomized complete block design. Five plants were sampled from each experimental unit at 30, 60, 90, 120, 150, and 180 days after planting. Growth rate, nutrient uptake and yield were determined. The results indicate that the yield and marketable number of fruits in both seasons increased with the addition of nitrogen. The highest yield was obtained with the addition of 150 kg N ha‐1. The maximum growth rate and the maximum rate of accumulation of dry matter in the fruits occurred during the period of 90 to 150 days after planting. This may indicate that the peak of the pepper N re.
Effects of fiber diameter and CO2 activation temperature on the pore characteristics of polyacrylonitrile based activated carbon nanofibers

The effects of fiber diameter and activation temperature on the pore characteristics of polyacrylonitrile based activated carbon nanofibers are investigated. It was found that lower fiber diameters as well as higher activation temperatures lead to a higher weight loss, specific surface area and total pore volume. The nitrogen adsorption capacity of activated carbon nanofibers is almost three times that of activated carbon fiber with a diameter of 10 µm. As far as the size of pores in activated carbon nanofibers is concerned, it is basically the micropores that dominate the scene. Moreover, tailoring the pore characteristics by adjusting the activation temperature and fiber diameter is plausible. Copyright © 2009 John Wiley & Sons, Ltd.
Changes in Structure, Morphology, Porosity, and Surface Activity of Mesoporous Halloysite Nanotubes Under Heating

The objective of the present study was to investigate changes in the structural, textural, and surface properties of tubular halloysite under heating, which are significant in the applications of halloysite as functional materials but have received scant attention in comparison with kaolinite. Samples of a purified halloysite were heated at various temperatures up to 1400°C, and then characterized by X-ray diffraction, electron microscopy, Fourier-transform infrared spectroscopy, thermal analysis, and nitrogen adsorption. The thermal decomposition of halloysite involved three major steps. During dehydroxylation at 500–900°C, the silica and alumina originally in the tetrahedral and octahedral sheets, respectively, were increasingly separated, resulting in a loss of long-range order. Nanosized (5–40 nm) γ-Al2O3 was formed in the second step at 1000–1100°C. The third step was the formation of a mullite-like phase from 1200 to 1400°C and cristobalite at 1400°C. The rough tubular morphology and the mesoporosity of halloysite remained largely intact as long as the heating temperature was <900°C. Calcination at 1000°C led to distortion of the tubular nanoparticles. Calcination at higher temperatures caused further distortion and then destruction of the tubular structure. The formation of hydroxyl groups on the outer surfaces of the tubes during the disconnection and disordering of the original tetrahedral and octahedral sheets was revealed for the first time. These hydroxyl groups were active for grafting modification by an organosilane (γ-aminopropyltriethoxysilane), pointing to some very promising potential uses of halloysite for ceramic materials or as fillers for novel clay-polymer nanocomposites.
A simplified modelling approach for quantifying tillage effects on soil carbon stocks

Soil tillage has been shown to affect long‐term changes in soil organic carbon (SOC) content in a number of field experiments. This paper presents a simplified approach for including effects of tillage in models of soil C turnover in the tilled‐soil layer. We used an existing soil organic matter (SOM) model (CN‐SIM) with standard SOC data for a homogeneous tilled layer from four long‐term field experiments with conventionally tilled (CT) and no‐till (NT) treatments. The SOM model was tested on data from long‐term (>10 years) field trials differing in climatic conditions, soil properties, residue management and crop rotations in Australia, Brazil, the USA and Switzerland. The C input for the treatments was estimated using data on crop rotation and residue management. The SOM model was applied for both CT and NT trials without recalibration, but incorporated a ‘tillage factor’ (TF) to scale all decomposition and maintenance parameters in the model. An initial value of TF = 0.57 (parameter uncertainty, PU = 0.15) for NT (with TF set to 1.0 for CT) was used on the basis of a previous study with observations of soil CO2 respiration. The simulated and observed changes in SOC were then compared using slopes of linear regressions of SOC changes over time. Results showed that the SOM model captured observed changes in SOC content from differences in rotations, N application and crop residue management for conventional tillage. On the basis of SOC change data a mean TF of 0.48 (standard deviation, SD = 0.12) was estimated for NT. The results indicate that (i) the estimated uncertainty of tillage effects on SOC turnover may be smaller than previously thought and (ii) simple scaling of SOM model parameters may be sufficient to capture the effects of soil tillage on SOM turnover in the tilled layer. Scenario analyses showed that the average extra C input needed to compensate for soil tillage was 762 (SD = 351) kg C ha−1 year−1. Climatic conditions (temperature and precipitation) also affected how much extra C was needed, with substantially larger inputs being required for wetter and warmer climates.
Salt and fat contents influence the microstructure of model cheeses, chewing/swallowing and in vivo aroma release

The effects of the lipid/protein ratio (20/28, 24/24, 28/20) and salt content of model cheeses were investigated simultaneously with respect to chewing behaviour, swallowing events and in vivo aroma release. Chewing parameters were measured by electromyography. Swallowing events were recorded manually. In vivo aroma release was investigated using nose-space on-line atmospheric pressure chemical ionisation-mass spectrometry. The values for chewing activity and time before swallowing were higher with lower lipid/protein ratios and lower salt contents, due to the greater mechanical resistance of the model cheeses. The corresponding microstructure was made up of smaller and more circular fat droplets in a stronger protein network. Furthermore, the maximum intensity and in-mouth release rate of aroma decreased as the lipid/protein ratio fell. This could be explained by a retention effect of the proteins, which was stronger than the chewing effect. A rise in salt content triggered more rapid aroma release from the protein phase of the model cheese to the oral cavity, and thence to the nasal cavity. The larger fat droplet size in salt-supplemented model cheeses slowed down the transfer of aroma release and the levels of aroma release after swallowing were higher. A more rapid swallowing was observed for model cheeses containing added salt and with a higher L/P ratio. It is suggested that this was due to greater salivation and lubrication. Moreover, the number of swallows was positively correlated to the total amount of aroma release.
Copper ion removal by almond shell carbons and commercial carbons: batch and column studies

Phosphoric acid-activated/oxidized, and steam-activated and steam-activated/oxidized almond shell granular activated carbons (GACs) were investigated for their utility in removing copper ion (Cu2+) from solution in both batch and column applications compared to commercially available GACs. Adsorption isotherms were developed and found to best fit the Freundlich model. Experimental and commercial carbons were packed into columns and exposed to two different empty bed contact times using a solution of 3 mM CuCl2 buffered at pH 4.8. The most effective GACs for removal of copper ions in batch mode were the phosphoric acid-activated/oxidized and steam-activated/oxidized experimental carbons. The most effective carbon in column mode appeared to be the phosphoric acid-activated/oxidized sample. A column packed with this carbon showed higher breakthrough volumes and greater estimated hours of operation than other experimental carbons and commercial carbons evaluated. This carbon could function as an effective metal ion adsorbent in water and wastewater treatment.
2,3‐Diphenylmaleic Anhydride, an Analogue of cis‐Stilbene

The asymmetric unit of the title structure, C 16 H 10 O 3 , consists of two molecules which have similar conformations. Each of the two pentagonal rings is planar, while the average dihedral angle between the two phenyl rings within each molecule is 57.4°. The molecules are held together by van der Waals forces, with the shortest intermolecular distance being 2.914 (11)A for O(3'). C(4)(1/2-x, -y,1/2 + z).