Miracle-dz/UniFAR-FTUs huggingface dataset:
Remediation of Cr(VI) and Pb(II) aqueous solutions using supported, nanoscale zero-valent iron

Borohydride reduction of an aqueous iron salt in the presence of a support material gives supported zero-valent iron nanoparticles that are 10−30 nm in diameter. The material is stable in air once it has dried and contains 22.6% iron by weight. The supported zero-valent iron nanoparticles (“Ferragels”) rapidly separate and immobilize Cr(VI) and Pb(II) from aqueous solution, reducing the chromium to Cr(III) and the Pb to Pb(0) while oxidizing the Fe to goethite (α-FeOOH). The kinetics of the reduction reactions are complex and include an adsorption phase. About 10% of the iron in the material appears to be located at active surface sites. Once these sites have been saturated, the reduction process continues but at a much lower rate, which is likely limited by mass transfer. Rates of remediation of Cr(VI) and Pb(II) are up to 30 times higher for Ferragels than for iron filings or iron powder on a (Fe) molar basis. Over 2 months, reduction of Cr(VI) was 4.8 times greater for Ferragels than for an equal weigh.
Preparation and Electrochemical Performance of CNT Electrode with Deposited Titanium Dioxide for Electrochemical Capacitor

To reduce polarization of electrochemical capacitor based on carbon nanotube, titanium oxide nanoparticles were deposited by ultrasound. The pore distribution of TiO2/CNT nanoparticle exhibited surface area of 341 m 2 g -1 when TiO2 content was 4 wt %, which was better than that of pristine CNT with surface area of 188 m 2 g -1 . The analyses indicated that titanium oxide (particle diameter < 20 nm) was deposited on the CNT surface. The electrochemical performance was evaluated by using cyclic voltammetry (CV), impedance measurement, and constant-current charge/discharge cycling techniques. The TiO2/CNT composite electrode showed relatively better electrochemical behaviors than CNT electrode by increasing the specific capacitance from 22 Fg -1 to 37 Fg -1 in 1 M H2SO4 solution. A symmetric cell assembled with the composite electrodes showed the specific capacitance value of 11 Fg -1 at a current loading of 0.5 mAcm -2 during initial cycling.
Vacuum Drying of Common Date Pulp Cubes

Drying ability of date (Phoenix dactylifera L.) pulp cubes from three Algerian common varieties (Mech-Degla, Degla-Beida, and Frezza) were investigated. Drying process was carried out under partial vacuum (200 mbar) at 60, 80, and 100°C. Compared to the Newton model, the Henderson and Pabis model better described drying kinetic of Mech-Degla and Frezza pulps at 60 and 80°C with a mean relative error (MRE) not higher than 6.07%. The same model fits experimental data at 60°C for Degla-Beida (R 2 = 0.988; MRE = 6.07) as well as at 100°C for only Mech-Degla (R 2 > 0.98, MRE = 8.61%).
Core–shell structure and segregation effects in composite droplet polymer blends

Core–shell morphology formation within the dispersed phase was studied for composite droplet polymer-blend systems comprising a high-density polyethylene matrix, polystyrene shell and different molecular weights of poly(methyl methacrylate) core material. The blends were prepared in the melt using an internal mixer, and the morphology was analyzed by electron microscopy. Changing the viscoelastic properties of the core in the dispersed phase dramatically affects PS-PMMA segregation within the dispersed composite droplet itself. A high-molecular-weight-PMMA core contains a large quantity of occluded PS inclusions, while the low-molecular-weight PMMA results in a perfectly segregated PS shell and PMMA core. These phenomena were attributed to the viscosity of the PMMA. Using the latter system, a direct microscopic study of the shell formation process demonstrates unambiguously that under conditions of perfect segregation, the onset of complete shell formation corresponds to a shell thickness that is close to two times the radius of gyration of polystyrene. Thus, the thinnest possible shell in such a system possesses a molecular-scale thickness. The system with the high-molecular-weight-PMMA core demonstrates an onset of complete shell formation that is displaced to higher concentrations due to the poor segregation effect. By counterbalancing the effects of viscosity ratio and interfacial effects on the composite droplet size, it is possible to generate perfectly segregated core–shell dispersed-phase morphologies of almost identical size with a controlled shell thickness ranging from 40 to 300 nm.
Gelation of Methylcellulose Hydrogels Under Isothermal Conditions

The current work deals with the gelation of methylcellulose (MC) in aqueous solutions under isothermal conditions. The isothermal gelation was monitored during two consecutive heating and cooling cycles. The gelation was observed to occur early during the second cycle and progress at a higher rate. Micelle-like structures were found to form in MC solutions during the first gelation cycle. These were largely responsible for the accelerated gelation during the second heating cycle. The influence from the state of water was examined by studying the gelation phenomenon for MC using either cold or hot DI water as solvent. The possible mechanism involved is discussed. A gel indexing method was established to provide a quantitative measure for the state of gelation achievable using different MC concentrations with either cold or hot water solvent. Stabilization kinetics for the gel under isothermal conditions was described using the Malkin and Kulichikhin model. The kinetics parameters were determined. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008
Occurrence of biflavones in leaves of Caesalpinia pyramidalis specimens

The chloroform partition of methanol extract of leaves of Caesalpinia pyramidalis was submitted to different chromatographic procedures which afforded besides agathisflavone and taxifolin, the minor biflavones loniflavone, amentoflavone, 5'- hydroxyamentoflavone and podocarpusflavone A. The structures of the compounds were established on the basis of NMR and MS data analysis. Besides, the content of biflavones of different specimens of C. pyramidalis, which are collected in different habitats of the Brazilian semi-arid region, was determinated by LC-APCI-MS analysis. These analysis demonstrated that only the specimens harvested in Bahia state showed collectively the presence of agathisflavone, amentoflavone, sequoiaflavone and podocarpusflavone A.
One‐pot New Barbituric Acid Derivatives Derived from the Reaction of Barbituric Acids with BrCN and Ketones

Reaction of cyclic β-dicarbonyl compounds such as pyrimidine-(1H,3H,5H)-2,4,6-trione (BA), 1,3-dimethyl pyrimidine-(1H,3H,5H)-2,4,6-trione (DMBA) and 2-thioxo-pyrimidine-(1H,3H,5H)-4,6-dione (TBA) with cyanogen bromide in acetone and 2-butanone in the presence of triethylamine afforded a new class of stable heterocyclic spiro[furo[2,3-d]pyrimidine-6,5′-pyrimidine]2,2′,4,4′,6′(3H,3′H,5H)-pentaones (dimeric forms of barbiturate) at 0 °C and ambient temperature. Structure elucidation was carried out by X-ray crystallographic, 1H NMR, 13C NMR, two dimensional NMR, FT-IR spectra, mass spectrometry and elemental analysis. The mechanism of product formation is discussed. The reaction of DMBA with cyanogen bromide in the presence of triethylamine also afforded trimeric form of barbiturate of uracil derivatives in good yield. The reaction of selected acyclic β-dicarbonyl compounds with cyanogen bromide in the presence of triethylamine in acetone and/or diethyl ether has also been investigated under the same condition. Diethyl malonate and ethyl cyanoacetate brominated and also ethyl acetocetate both brominated and cyanated on active methylene via cyanogen bromide.
Relationship between microwave and lattice vibration properties in Ba(Zn1/3Nb2/3)O3-based microwave dielectric ceramics

The dielectric properties of (1 − x)Ba(Zn1/3Nb2/3)O3–xBa (Ga1/2Ta1/2)O3 (BZN–xBGT) microwave (MW) ceramics, with x between 0 and 0.2, and those of 0.9Ba(Zn0.6Co0.4)1/3Nb2/3O3–0.1Ba(Ga0.5Ta0.5)O3 (BZCN–BGT) were studied at MW, terahertz (THz) and infrared (IR) frequencies at temperatures from 10 to 300 K. At room temperature, the temperature coefficient of resonance frequency (τf) near 3 GHz decreases from 28 ppm K−1 in undoped BZN to 2 ppm K−1 in BZN–0.2BGT and reduces to zero in BZCN–BGT. The addition of BGT to BZN depresses the dielectric Q value, but incorporation of Co improves the Q values, yielding Q ~ 30 000 at 3 GHZ in BZCN–BGT. The relative permittivity (e') exhibits only limited variation with composition (e' values in the range 34.4–36.0). IR and THz spectra as well as the low-temperature MW dielectric measurements revealed a weak dielectric relaxation below phonon frequencies, possibly arising from charges caused by inhomogeneous distribution of the B-site ions with differing valences. The IR reflectivity spectrum of BZN–0.2BGT is significantly different (smeared) compared with other compositions, which may be caused by disorder on the B sites and by an amorphous phase at the grain boundaries.
Disasters Aggravate Present Bias Causing Depression: Evidence from the Great East Japan Earthquake

Disasters affect livelihoods and preferences. We investigate the relationship between damage caused by a disaster and individual hyperbolic discounting, adopting sui generis data from two communities hit by the Great East Japan Earthquake of 2011: Iwanuma and Futaba, where exposure to a disaster aggravates an individual's present bias captured in elementary or junior high school. This causal relationship is a key mechanism behind the disaster and depression nexus. Our results suggest the need to provide commitment devices to mitigate harmful outcomes induced by aggravated hyperbolic discounting resulting from disaster exposure, thus shedding new light on disaster rehabilitation policies.
Water Permeation Through Catalyst-Coated Membranes

Water permeabilities, driven by concentration or pressure gradients, through NRE211 and catalyst-coated membranes are reported, and the effect of the catalyst layer (∼ 18 μm thick, 30 wt % Nafion ionomer, carbon-supported Pt, 0.4 mg Pt cm ―2 ) on membrane water permeation is deconvoluted. For the system studied, water permeation is limited by the bulk membrane; the effect of the catalyst layer was insignificant and, despite catalyst layers being deposited on the membrane's surface, it does not influence the rates of sorption or desorption at membrane interfaces.
High-pressure phase relation of MnSiO3 up to 85 GPa: Existence of MnSiO3 perovskite

Abstract The high-pressure phase relation of MnSiO3 was examined up to 85 GPa and 2600 K using a laserheated diamond-anvil cell combined with synchrotron radiation. MnSiO3 garnet decomposes into a mixture of MnO with a rock-salt structure (B1) + SiO2 stishovite at pressures higher than ~20 GPa and temperatures higher than ~1200 K. However, MnO (B1) + SiO2 stishovite further transforms to a perovskite structure with increasing pressure. The phase boundary between these structures is positive in the pressure-temperature diagram. The triple point of garnet, MnO + SiO2 and perovskite in the pressure-temperature diagram is ~20 GPa and 1200 K. MnSiO3 perovskite is orthorhombic, and consistent with space group Pbnm, both at high pressure and high temperature and at high pressure and room temperature, but becomes amorphous during decompression. The refined cell parameters of MnSiO3 perovskite at 85 GPa and 2600 K are a = 4.616(2) Å, b = 4.653(2) Å, c = 6.574(3) Å, and V = 141.2(2) Å3. The a/b ratio increases (approaches 1) with pressure and temperature, while the √2a/c ratio remains nearly constant (<1). This indicates that the orthorhombic distortion decreases and the structure tends toward a tetragonal perovskite with increasing pressure and temperature.
Effect of frying variables on French fry properties

Summary This work focuses on the effect of frying variables (repeated frying, potato-to-oil ratio, potato distribution in the fryer, oil type and potato variety) on French fry properties (water content, oil content, crust thickness and shrinkage). Furthermore, the rate of change in French fry properties during a frying batch is investigated. The temperature was acquired in several positions within the oil and the potato. It was found that when repeated frying was conducted up to regulation limits for frying oil use, the examined French fry properties were not significantly affected. On the contrary, the potato-to-oil ratio, potato distribution and potato variety significantly affected the water content of French fries. The most significant changes occurred during the first 1–2 min of a frying batch. According to the temperature measurements, the crust-core front continued to advance after this first frying period. However, there was no observable crust thickness increase; this was attributed to crust shrinkage.
Digital Commons @ Michigan Tech Digital Commons @ Michigan Tech Aerosols-cloud microphysics-thermodynamics-turbulence: Aerosols-cloud microphysics-thermodynamics-turbulence: Evaluating supersaturation in a marine stratocumulus cloud Evaluating supersaturation in a marine stratocumulus cloud

This work presents a unique combination of aerosol, cloud microphysical, thermodynamic and turbulence variables to characterize supersaturation ﬂuctuations in a turbulent marine stratocumulus (SC) layer. The analysis is based on observations with the helicopter-borne measurement platform ACTOS and a detailed cloud microphysical parcel model following three different approaches: (1) From the comparison of aerosol number size distributions inside and below the SC layer, the number of activated particles is calculated as 435 ± 87 cm − 3 and compares well with the observed median droplet number concentration of N d = 464 cm − 3 . Furthermore, a 50 % activation diameter of D p50 ≈ 115 nm was derived, which was linked to a critical supersaturation S crit of 0.16 % via K ¨ ohler theory. From the shape of the fraction of activated particles, we estimated a standard deviation of supersaturation ﬂuctuations of σ S 0 = 0.09 %. (2) These estimates are compared to more direct thermodynamic observations at cloud base. There-fore, supersaturation ﬂuctuations ( S 0 ) are calculated based on highly-resolved thermodynamic data showing a standard deviation of S 0 ranging within 0.1 % ≤ σ S 0 ≤ 0 . 3 %. (3) The sensitivity of the supersaturation on observed vertical wind velocity ﬂuctuations is investigated with the help of a detailed cloud microphysical model. These results show highest ﬂuctuations of S 0 with σ S 0 = 0 . 1 % at cloud base and a de-creasing σ S 0 with increasing liquid water content and droplet number concentration. All three approaches are independent of each other and vary only within a factor of about two.
Nuclear Resonance Absorption in Hydrated Crystals: Fine Structure of the Proton Line

Fine structure has been observed in the nuclear paramagnetic resonance absorption line for protons in crystalline hydrates. The magnetic field of 6820 gauss was provided by a permanent magnet, the inherent stability of which facilitated detailed study of line shape. Measurements on a single crystal of CaSO4·2H2O show a splitting into four component lines with maximum separation varying from zero to 22 gauss, depending upon the direction of the externally applied magnetic field in the crystal. Both the number of component lines and the dependence of their spacing on field direction are calculated by treating the magnetic dipole‐dipole interaction as a perturbation of the proton two‐spin system within the water molecule; the effect of the more distant protons, neglected in this calculation, gives a finite width to the component lines. Variation of the splitting with field direction determines the orientation of the line joining protons in the water molecule, which is found to be consistent with positions ascribed to hydrogen nuclei in the lattice through simple considerations of chemical bonding. The distance between protons in the water molecule is measured by the splitting to be 1.58A for CaSO4·2H2O; if one assumes an H–O–H bond angle of 108°, the O–H distance is 0.98A. Powdered hydrates show a characteristic fine structure arising from isotropic distribution in solid angle of single crystal granules. This type of fine structure determines the proton‐proton distance somewhat less accurately than does the single crystal experiment.
Effect of dielectric medium on angiotensin converting enzyme inhibitors binding to Zn2+

The Becke3LYP density functional was used to study structural and thermodynamic parameters of bivalent zinc cation complexes with selected substrates and ACE inhibitors (H2O/OH−, neutral forms of captopril, zofenoprilat, omapatrilat, CH3CONHCH3, and N-terminal anions of captopril, zofenoprilat, omapatrilat, enalaprilat, perindoprilat, trandolaprilat, and fosinoprilat). The combination of DFT and the conductor-like polarizable continuum model (CPCM) were employed to compute the Gibbs interaction energies (ΔG) between Zn2+ and the selected ACE inhibitors for dielectric media with ɛ = 5 (to simulate the protein environment) and for water media (ɛ = 78.39) for comparison purposes. The results show that ΔG is sensitive to the dielectric constant of the environment and that lower dielectric medium favors the binding of inhibitors to the zinc cation.
Simultaneous Measurement of Three Tocopherols, All-trans-retinol, and Eight Carotenoids in Human Plasma by Isocratic Liquid Chromatography

We describe a simplified isocratic HPLC method for the simultaneous determination of all-trans-retinol, 3 tocopherols (α-, δ-, and γ- tocopherol), and 8 carotenoids (lutein, zeaxanthin, canthaxanthin, β-cryptoxanthin, all-trans-lycopene, 5-cis-lycopne, α-carotene, and β-carotene) in human plasma, which uses a single C18 reversed-phase column (4.6 × 250 mm, 3 µm). A photodiode array detector was used to measure the UV‐vis wavelength absorbance of retinol and the eight carotenoids, and fluorescence detection was used for the tocopherols. The linear ranges of the calibration curves for the calibration solutions injected into the HPLC column are 0.02‐6.0 µg/mL for all-trans-retinol, β-cryptoxanthin and α-carotene; 0.01‐3.0 µg/mL for δ-tocopherol, lutein, and lycopene; 0.08‐24.0 µg/mL for γ-tocopherol; 0.3‐90.0 µg/mL for α-tocopherol; 0.005‐1.5 µg/mL for zeaxanthin and canthaxanthin; and 0.04‐12.0 µg/mL for β-carotene.
Methanol carbonylation revisited: thirty years on.

Monsanto initiated development of its rhodium- and iodide-catalysed process for the carbonylation of methanol to acetic acid in 1966. Ownership of the technology was acquired in 1986 by BP Chemicals who have further extended it. The work of the Sheffield group, in developing a deeper understanding of the mechanism of the process, is reviewed. The rate-determining step in the rhodium–iodide catalysed reaction is the oxidative addition of methyl iodide to [Rh(CO)2I2]–1a: the product from this reaction, the reactive intermediate [MeRh(CO)2I3]–2a has been detected and fully characterised spectroscopically. The rates of the reversible reactions linking 1a, 2a and the acetyl complex [(MeCO)Rh(CO)I3]–3a, as well as activation parameters for several of the processes involved, have been measured. The efficiency of methanol carbonylation arises primarily from rapid conversion of 2a into 3a, leading to a low standing concentration of 2a, and minimising side reactions such as methane formation. By contrast, in the iridium-catalysed carbonylation, for which similar cycles can be written, the reaction of [MeIr(CO)2I3]–2b with CO to give [(MeCO)Ir(CO)2I3]–4b is rate determining. Model studies show that while kRh/kIr is ca. 1 : 150 for the oxidative addition, it is ca. 105–106 : 1 for migratory CO insertion. The migratory insertion for iridium can be substantially accelerated by adding either methanol or a Lewis acid (SnI2); both appear to facilitate substitution of an iodide ligand by CO, resulting in easier methyl migration. The carbonylation of higher alcohols (ROH) has also been successfully modelled; the corresponding alkyl iodides (RI) react much more slowly than MeI with [M(CO)2I2]–, but again give the acyls [(RCO)M(CO)I3]– for M = Rh and the alkyls [RM(CO)2I3]– for M = Ir. The greater stability of [MeIr(CO)2I3]– compared with [MeRh(CO)2I3]– accounts for the very different characters of the reactions catalysed by the two metals. It is suggested that the broad features of the Rh/Ir reactivities can be rationalised since the M–C bond to a 5d metal is generally stronger than that to the corresponding 4d metal; thus if metal–ligand bond making plays a key role in a step, then the 5d metal is more likely to react faster (e.g. in the oxidative addition), but if a metal–ligand bond-weakening or -breaking step plays a key role in a process (e.g. in the migration), it is likely that the 4d metal will be faster.
Treatment of dairy industry wastewater by EC and EF processes using hybrid FeAl plate electrodes

BACKGROUND: In this study electrochemical treatment of dairy industry wastewater (DW) was investigated using a combined electrode system consisting of iron and aluminum as sacrificial electrodes. The dairy industry generates strong wastewaters characterized by high biological oxygen demand and chemical oxygen demand concentrations. Dairy industry waste effluents are concentrated in nature, and the main contributors of organic load to these effluents are carbohydrates, proteins and fats originating from the milk. Since dairy waste streams contain high concentrations of organic matter, these effluents may cause serious environmental problems. RESULTS: A pole changer device was employed to change polarization in given time intervals to generate iron and aluminum based coagulants respectively. The effects of current density, initial pH, sodium sulfate (Na2SO4 )a nd H 2O2 concentrations on the removal efficiency were investigated. The best experimental conditions obtained in electrochemical studies were as follows: current density = 15 mA cm −2 , natural pH, without supporting electrolyte addition, H2O2 concentration = 3 × 1000 mg L −1 . Under these conditions, 79.2% COD removal from DW was achieved. CONCLUSION: According to the results, 20 min electrolysis is enough, since insignificant variations in COD removal were observed after this time. These methods were found to be successful for the treatment of DW. c � 2011 Society of Chemical Industry
Drastic Phase Transition in Ionic Liquid [Dmim][Cl] Confined Between Graphite Walls : New Phase Formation

Confinement can induce unusual behavior in the properties of matter. Using atomistic molecular dynamics simulations, we report here a liquid-to-solid transition of a bilayer of ionic liquid 1,3-dimethylimidazolium chloride ([Dmim][CI]) confined between graphite walls in order to mimic the phase transition of an ionic liquid confined to hydrophobic nanospace. It was found that the ionic liquid bilayer undergoes a clear and drastic phase transition at a wall distance of about 1.1 nm, forming a new high-melting-point solid phase with different hydrogen bonding networks. In the new phase, each cation is surrounded by the three nearest-neighbor anions, and each anion is also encircled by the three nearest-neighbor cations. Strong pi-pi stacking interactions are found between the cations of the bilayer solid. The anions can be formed into a hexagonal ring around the cations. The new bilayer solid is a high-melting-point crystal possessing a melting point of 825-850 K, which is higher than that of the bulk crystal by more than 400 K.