Miracle-dz/UniFAR-FTUs huggingface dataset:
Interferometric Technique for Measuring Interdiffusion at High Pressures

Mach-Zehnder optical interferometry with phase shifting is applied to interdiffusion experiments in binary liquid mixtures. A new method of analysis is presented and applied to measurements on two test systems, NaCVwater and 1 -butanol/water at atmospheric pressure and room temperature, and to numerical solutions of the diffusion equation. The precision and accuracy of the technique is found to be 0.6% for the NaCV water system and 1.4% for the 1-butanoywater system. The analysis is based on the assumption of ideal boundary conditions and expansion in Hermite polynomials of the reduced phase of the light passing through the sample, (D(q), around the solution to the ideal diffusion equation. The numerical calculations show that an approximation, &H? , to the reduced second moment of the derivative (I)'(? ) is a better estimate for the diffusion coefficient than the reduced height area ratio, g ~ , obtainable by Rayleigh and Gouy interferometry. The analysis yields a measure of a single-experiment accuracy. The main source of error is not in the data acquisition or analysis but rather in the way the initial concentration profile is established. We also report new experimental interdiffusion coefficients of methaneln-decane, for mole fraction of methane 0.098, temperatures 30, 90, and 150 O C , and pressures 20, 40, and 60 MPa. These diffusion coefficients have an estimated accuracy of between 0.7 and 2%. An extension of the model of Assael et al. is fitted to the data to within experimental accuracy.
Temperature‐Dependent Photonic Bandgap in a Self‐Assembled Hydrogen‐Bonded Liquid‐Crystalline Diblock Copolymer

We take advantage of self‐assembly in a hierarchically structured, hybrid material to develop photonic bandgaps in the visible which may be systematically tuned by application of thermal or electric fields. Hydrogen bonding between a host polymer and a guest small molecule is used to augment the molecular weight of an appropriately selected coil–coil diblock copolymer to bring the microdomain structure onto the length scale needed for significant interaction with visible light. Further, the use of liquid‐crystal‐mesophase‐forming moieties as the guest hydrogen‐bonding units adds functionality to the system as the optical properties of the liquid‐crystalline domains can be modulated by external stimuli. We use hydrogen bonding to sequester varying amounts of imidazole terminated mesogens within the acid domains of a poly[styrene‐block‐poly‐(methacrylic acid)] (PS‐b‐MAA) diblock copolymer. The resulting PS‐b‐MAA/LC side‐group liquid‐crystalline diblock copolymer possesses a photonic bandgap in the green with the exact location and structure of the gap dependent on the composition of the system. Here, we discuss the structure and optical properties of these materials as a function of their composition and the response of the optical properties to temperature. Varying the order parameter of the LC domains by heating into the isotropic state changes the peak reflectivity by 40 nm, resulting in a color change from green to orange.
Color and Mass Transfer Kinetics During Air Drying of Pretreated Oyster Mushrooms (Pleurotus ostreatus spp.)

The color and mass transfer kinetics during air drying as well the desorption isotherms at 40, 50, and 60°C of Pleurotus ostreatus mushrooms were studied. Blanched and sulfated mushrooms were tested against untreated samples to study the browning development. The analysis of sorption isotherms based on the Blahovec-Yanniotis model provided insight into the sorption mechanisms, the shape of the sorption isotherms, and the diffusion coefficient decrease at the later stages of the drying. The mean thickness of the samples decreased by 50% during drying, which dictates the necessity to include shrinkage in the mass transfer analysis. The estimated diffusivities were 2.89 × 10−11–2.20 × 10−10 m2/s for sulfated mushrooms, 3.75 × 10−11–1.69 × 10−10 m2/s for blanched mushrooms, and 3.62 × 10−11–2.11 × 10−10 m2/s for untreated mushrooms. An analytical solution of Fick's second law employing a modified method of slopes and considering the shrinkage effect was used to estimate the nonlinear water diffusion. The statistical analysis showed that drying temperature and pretreatment significantly interaction affected water diffusivity. Color analysis was based on reduced lightness and Browning index (BI) change with time, temperature, and pretreatment. The difference in the of blanched mushrooms from sulfated and untreated samples was decreased as drying temperature increased. The BI change was modeled by a new first-order kinetics model. The estimated energy of activation (E a ) values were 44.8, 32.5, and 28.0 kJ/mol for untreated, blanched, and sulfated mushrooms, respectively. The E a values show that untreated mushrooms are more sensitive to temperature change than the pretreated mushrooms during thermal processing.
Effect of short–time variations of wind velocity on mass transfer rate between street canyons and the atmospheric boundary layer

Abstract 2D URANS CFD simulations were conducted to study the effect of short–time variations of wind velocity on mass transfer rate between street canyons and the atmospheric boundary layer (ABL). A street canyon with a height–to– width ratio (aspect ratio) of three was considered as a case study. The study is of practical interest since it illustrates a skimming flow regime, the regime where pollutants are less effectively exchanged between the canyon and the above atmosphere, typically found in many urban areas in Mediterranean countries. Short–time variations of wind velocity magnitude were simulated assuming a sinusoidal function with average magnitude = 4 m s −1 ; amplitude ±2 m s −1 and period from 1 to 40 s, and subsequently with short–time averaged (0.1 s, 1 s and 10 s) real world data measured with an ultrasonic anemometer (50 Hz). Mass transfer rate between the canyon and the ABL was evaluated as the rate of reduction of spatially averaged concentration of a passive pollutant, carbon monoxide (CO), in the street canyon. Results show that mass transfer rate increases with the frequency of short–time variations. In CFD studies pertaining to pollutant dispersion in street canyons, wind hourly average velocity is usually assumed as a reference value to simulate real world cases. Our results show that this input data must be completed with additional information about the extent of variation in wind intensity and its frequency in the hour.
Parameters influencing biotransformation rates of phenylurea herbicides by soil microorganisms

Abstract The biotransformation of phenylurea herbicides and some of their most prominent degradates by different soil microorganisms was investigated. Most soil fungi, but only some soil bacteria, were able to reduce the herbicide concentration in the culture medium. Biotransformation rates of the compounds were different. Identification of the products demonstrated that N-demethylation was the most common initial biotransformation step. Cleavage of the urea bridge was only observed by bacteria. Sorption of the compounds to the mycelium or cells was different among the microorganisms investigated, but studies with 14 C-labeled compounds revealed that the herbicides were not bound to any organic material such as cell walls or membranes. Mineralization of the phenyl ring did not occur. None of the microorganisms were able to use the herbicides as the sole carbon source, indicating that biotransformation was a cometabolic process. In some cases, the different biotransformation rates correlated with the lipophilicity of the compounds. Herbicides with high octanol-water partition coefficients were then transformed faster than compounds with a high water solubility. Some microorganisms, however, showed rapid biotransformation of certain, but different, herbicides. This indicates either additional biotransformation pathways or substrate specificities.
pH and Procaine Sensing Characteristics of Extended-Gate Field-Effect Transistor Based on Indium Tin Oxide Glass

The pH sensing properties of an extended-gate field-effect transistor (EGFET) based on indium tin oxide (ITO) glass are investigated in this study. The separating structures in the EGFET are examined using a current–voltage measurement system to measure I–V curves. A readout circuit is applied to measure the pH sensing EGFET output voltage, and nonideal factors (drift and hysteresis effects) are monitored in different buffer solutions (pH=1–11). It was found that separating structures for ITO glass sensors have a high pH sensitivity (∼55 mV/pH), a low drift rate and a small hysteresis width in the concentration range between pH=1 and 11 in buffer solutions. The EGFET was used in fabricating a drug-sensitive field-effect transistor (DrugFET) sensor for procaine hydrochloride. The DrugFET was prepared using a combination of the EGFET and a drug-sensitive membrane that measured the procaine concentration in the 1×10-2–1×10-6 mol/L range. The separating structure was used with a procaine DrugFET with a good response (∼200 s) at room temperature.
Phytochemical and Biological Studies of Averrhoa carambola

p-Anisaldehyde (1) and β-sitosterol were isolated from carbon tetrachloride and chloroform soluble portion of the methanol extract of stem bark of Averrhoa carambola. The structures of the isolated compounds were elucidated by spectroscopic studies and by comparison with published data. Different partitionates of the methanol extract exhibited significant antimicrobial activities and varying degrees of cytotoxicity.
Macro- and Micromorphology of Monoclinic Paracetamol Grown from Pure Aqueous Solution

The morphology of monoclinic paracetamol crystals has been investigated both theoretically and experimentally. Calculations using the computer program HABIT 95 with both DREIDING II and MOMANY force fields predict prismatic forms in which {100}, {001}, {110}, and {201} show approximately equivalent morphological importance. Whereas all of these faces are observed experimentally, the real crystals showed a {110} dominance at low supersaturations which gave way to an increasing {001} dominance as the supersaturation increased. This variation was accompanied by a change from a columnar to a platelike habit. Surface examinations using phase contrast microscopy showed the habit changes to be due principally to changes in the growth mechanism of the {110} faces. A slow growth process involving two-dimensional nucleation at a few growth sources occurred at low supersaturations. This gave way to dislocation growth and finally at high supersaturations, to a fast growing mixed mechanism combining two-dimensional g.
Effect of irradiation on the stability of minced cod, with and without hydrocolloids during frozen storage

Etude de la texture, de la capacite de retention d'eau, de la lipolyse et de la formation de dimethylamine de chair de cabillaud entreposee a l'etat congele (-10 o C), apres irradiation a faible dose et addition ou non de cryoprotecteurs (xanthane, carboxymethyl cellulose, carraghenane iota)
TLC Separation of Isomeric Diazinodithiins and Diazinyl Sulfides as the Smiles Rearrangement Products

Abstract The reactions of diazinodithiins 1, 5, and 9 with sodium methanethiolate in DMSO, followed by methylation with methyl iodide, proceed with or without the Smiles rearrangement to give isomeric diazinodithiins 4, 8, and 12 and diazinyl sulfides 2, 3, 6, 7, 10, and 11. The aim of this was to find TLC conditions to follow the rearrangement, to separate and identify thioazines 1–12. The retention parameter RF was measured and next calculated as separation factors ΔRF, RS, and α. The RF values were correlated with the dipole moments of thioazines 1–12 and the symmetry (C2h and C2v) of diazinodithiins 1, 4, 5, 8, 9, and 12.
Determination of total contents of bromine, iodine and several trace elements in soil by polarizing energy-dispersive X-ray fluorescence spectrometry

A non-destructive analysis method for total bromine (Br) and iodine (I) contents in soil was established using polarizing energy-dispersive X-ray fluorescence (EDXRF) spectrometry. The matrix-corrected intensity of Br and I Kα X-rays from pressed pellets of soil powder samples was calibrated with their contents measured by inductively coupled plasma (ICP)-mass spectrometry after pyrohydrolysis preparation. The calibration curves for Br and I were successfully obtained in the concentration ranges 3.8–223 mg kg−1 and 0.91–54 mg kg−1 respectively. Repeated analyses of the same sample with polarizing EDXRF spectrometry within one day and after approximately 1.5 years showed good reproducibility of the measurement results. The lower limits of detection for Br and I were 0.14 mg kg−1and 0.34 mg kg−1 respectively. The established analytical method for total Br and I contents in soil is non-destructive, simple and rapid, and is suitable for routine analysis. Trace elements such as rubidium (Rb), strontium (Sr), yttrium (Y), zirconium (Zr), niobium (Nb), cadmium (Cd), tin (Sn), antimony (Sb), caesium (Cs), barium (Ba), light rare earth elements and lead (Pb) were also measurable simultaneously under the identical operational conditions as those for Br and I measurements.
Flow Injection Continuous Liquid-Liquid Extraction Using a Hollow Fiber Membrane Separator for Determination of Copper in Water

ABSTRACT A simple flow injection photometric method for the determination of copper was developed based on the formation and liquid-liquid extraction of the analyte-bathocuproine-perchlorate ternary complex. The analytical reaction of complex formation is integrated with the continuous liquid-liquid extraction procedure. A hollow fiber-type membrane separator was specially constructed for the determination. The analytical properties like sensitivity, precision, accuracy and rapidity were evaluated. The sensitivity of the method depends on the injection volume. By using an injection volume of 0.6 ml, the detection limit (3σ) found was 15 ng ml−1 copper, with a determination range of 48 - 3000 ng/ml. The repeatability of the method, expressed as the relative standard deviation, was in all instances less than 3.0%. The sampling rate was of 20 h−1. The accuracy of the method was tested with certified reference materials, and the mean error was calculated to be less than 5%. The method was successfully applied.
SYNTHESIS OF A NOVEL POLYSACCHARIDE HYDROGEL

ABSTRACT A modified hyaluronic acid (HA) biopolymer was synthesized that can be photocrosslinked to form a stable hydrogel. The chemical and physical properties including the amount of modification of the polymer with methacrylate anhydride, the viscosity of the modified biopolymer, and the solute diffusion characteristics of the polymer have been determined.
Superabsorbent polymeric materials. II. Swelling behavior of crosslinked poly[sodium acrylate-co-3-dimethyl(methacryloyloxyethyl) ammonium propane sulfonate] in aqueous salt solution

A series of xerogels based on sodium acrylate (SA), 3-dimethyl (methacryloyloxyethyl) ammonium propane sulfonate (DMAPS), and N,N′-methylene-bis-acrylamide (NMBA) are prepared by inverse suspension polymerization. The water absorbencies or swelling behaviors for these xerogels in water or various saline solutions respectively exhibit a value of 1435 g H2O/g sample and 96 g H2O/g sample of deionized water and 0.9 wt % NaCl solution at a gel containing 1.88 × 10−3 molar ratio of DMAPS while the extent of 1.53 × 10−3 molar ratio (0.25 wt % based on total monomer) of NMBA was used in the polymerization. The absorbency in the chloride salt solutions decreases with an increase in the ionic strength of salt. For the same ionic strength of various salt solutions, the swelling amount has the following tendency: Na+ > Fe3+ > A13+ > Ca2+ for the higher ionic strength of 5 × 10−3 −2 × 10−2M and Na+ > Fe3+ > Ca2+ > A13+ for the lower ionic strength of < 2 × 10−4M. The bound water found by DSC investigation is approximately equal to 2 g H2O/g sample. The pH effect and thermal effect on the water absorbency for these xerogels are also investigated. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1701–1712, 1997
Stereoselective Desymmetrizations by Recombinant Whole Cells Expressing the Baeyer–Villiger Monooxygenase from Xanthobacter sp. ZL5: A New Biocatalyst Accepting Structurally Demanding Substrates

In this work the substrate profile and stereoselectivity of engineered whole cells overexpressing the Baeyer–Villiger monooxygenase from Xanthobacter sp. ZL5 with respect to biotransformations of prochiral substrates is characterized. This enzyme catalyzes the desymmetrization of cyclic ketones bearing different chemical features with stereoselectivity similar to that obtained with a related protein fromAcinetobacter as a prototype representative of the cyclohexanone monooxygenase enzyme cluster. Moreover, this biocatalyst is able to convert sterically demanding substrates previously not transformed by other enzymes with excellent enantioselectivities. These results expand the repertoire of optically pure lactones accessible by whole-cell biotransformation processes, which are useful intermediates for the synthesis of natural and bioactive products. In addition, we observed a remarkable epoxidation reaction of a non-activated C=C bond catalyzed by this monooxygenase. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Individually suspended single-walled carbon nanotubes in various surfactants

Individual single-walled carbon nanotubes (SWNTs) have been suspended in aqueous media using various anionic, cationic, nonionic surfactants and polymers. The surfactants are compared with respect to their ability to suspend individual SWNTs and the quality of the absorption and fluorescence spectra. For the ionic surfactants, sodium dodecylbenzene sulfonate (SDBS) gives the most well resolved spectral features. For the nonionic systems, surfactants with higher molecular weight suspend more SWNT material and have more pronounced spectral features.
Surface Photovoltage of Porphyrin Layers Using the Kelvin Probe Technique

The Fermi energy of spin-coated layers of pyridinium porphyrins on indium tin oxide (ITO) was determined by the Kelvin probe technique. The work function of zinc tetrakis(N-methyl-4-pyridinium)porphyrin (ZnTMPyP) was found to be 500 meV larger than the one of metal-free tetrakis(N-methyl-4-pyridinium)porphyrin (H2TMPyP), which indicates that the Fermi levels ascribed to these molecular layers do not lie in the middle of their energy gap but that the layers show a p-type and an n-type character, respectively. Furthermore, from the dependence of the work function on the layer thickness, we deduce that an electric field is present near the porphyrin/ITO interface. This field extends over 10−20 nm and is oriented such that the porphyrin layers are depleted from majority mobile carriers near the ITO interface. However, this field does not contribute significantly to the photovoltage, which indicates a high density of interface traps at the ITO interface. Surface photovoltage measurements under illumination of .
Analysis of the hazards for the molten cuprous chloride pouring operation in an industrial hydrogen production facility

An analysis is reported of a design for a local exhaust ventilation system for the molten cuprous chloride pouring station in an industrial plant. Heat recovery from molten cuprous chloride is a key process within the copper–chlorine (Cu–Cl) cycle of thermochemical water splitting for hydrogen production. Because of particulate matter, dust, and vapors emitted by the molten salt, an effective and safe design is crucial. The design process involves calculating duct diameters to provide the desired duct air velocity through the system. The static pressure is evaluated so that the fan size can be determined. An adequate supply of makeup air must be provided to replace the air exhausted through the ventilation system. The economics of the ventilation system and ways to protect employee health, as well as minimize the costs associated with exhaust ventilation, are also described. Copyright © 2011 John Wiley & Sons, Ltd.
Antibacterial activity of Tagetes minuta L. (Asteraceae) essential oil with different chemical composition

The essential oils from aerial parts of Tagetes minuta L. grown in Egypt, South Africa and the UK were obtained by hydrodistillation. Although they had similar constituents, the oils had different percentage compositions. Dihydrotagetone was the most abundant component of the oils from the UK (34.3 and 54.1%), while the oils from South Africa and Egypt were characterized by a high content of cis-β-ocimene (50.9 and 32.0%, respectively). The oils exhibited antibacterial activity, especially against Gram-positive bacteria. Antimicrobial activity was greater in oils from the UK than in oils from Egypt or South Africa, irrespective of whether the UK plants had been grown in a greenhouse or in the field. The minimum inhibitory concentrations (MIC) for the oil from UK greenhouse-grown plants were 6.25-25 μg/mL for Gram-positive bacteria and 25-50 μg/mL for Gram-negative bacteria, with the lowest MIC of 6.25 μg/mL against Streptococcus faecalis. Oil from plants from South Africa had MICs of 50-100 μg/mL against Gram-positive and Gram-negative bacteria. The MICs of oil from plants from Egypt against all tested bacteria except Pseudomonas aeruginosa and Salmonella typhi were half of the MICs of oil from plants from South Africa.
High Dose Ion Implantation into Photoresist

The characteristics of heavily ion‐implanted photoresist films were studied in relation to types of photoresist, ion species, accelerating energies, and dose levels. By high energy, high dose ion implantation it was observed that the optical transmission of the resist film was exceedingly decreased and the resist becomes more mechanically, thermally, and chemically resistant. Several experimental data indicated that these results are due to the change of photoresist to disordered graphite. As an application of this ion‐implanted resist, a new photomask fabrication process is developed.
Gas-permeation properties of poly(ethylene oxide) poly(butylene terephthalate block copolymers

This paper reports the gas-permeation properties of poly(ethylene oxide) (PEO) poly(butylene terephthalate) (PBT) segmented multiblock copolymers. These block copolymers allow a precise structural modification by the amount of PBT and the PEO segment length, enabling a systematic study of the relationship between polymer composition and morphology and gas-transport properties. The CO2 and N2 permeability strongly varies with the amount of PEO and the PEO segment length. The permeabilities are compared to predictions of the Maxwell model, which considers the PBT phase as impermeable. The difference between the experimental values and the Maxwell model are interpreted on the basis of chain flexibility of the PEO phase. The chain flexibility decreases with increasing amounts of PBT due to a less pronounced phase separation between the PEO and PBT phase. This is reflected in an increasing glass-transition temperature of the amorphous PEO phase. The increase of the permeability with an increasing PEO block length, at the same ratio PEO-PBT, can therefore be related to a larger chain flexibility for longer PEO segments. The permeability also depends on the degree of crystallinity and the melting temperature of the PEO phase, which increases with the amount and the PEO segment length. PEO-PBT block copolymers exhibit a high CO2/N2selectivity ( 60 at T = 35 C) due to the high solubility of CO2 in the PEO phase. However, this selectivity is structure-dependent and is higher for block copolymers with larger amounts of PBT. The CO2/He selectivity shows a different structure dependency since the permeation of CO2 occurs primarily through the PEO phase and the He permeation occurs through both the PEO and mixed PEO-PBT interphase. Therefore, block copolymers with a better phase separation between the PEO phase and the PBT phase show a higher CO2/He selectivity.