Miracle-dz/UniFAR-FTUs huggingface dataset:
Kinetics of HO2 Uptake in Levoglucosan and Polystyrene Latex Particles

The uptake coefficient(γ) of HO2 for submicrometer aerosol particles of levoglucosan and polystyrene latex (PSL) under ambient conditions (760 Torr and 296 ± 2 K) have been investigated using an aerosol flow tube (AFT) coupled with a chemical conversion/laser-induced fluorescence (CC/LIF) technique. Determined γ values for levoglucosan particles were <0.01, 0.01 ± 0.01, 0.05 ± 0.01, 0.09 ± 0.02, and 0.13 ± 0.03, at relative humidities (RHs) of 20, 40, 55, 75, and 92%, respectively, while the γ values for PSL particles were 0.01 ± 0.01, 0.02 ± 0.01, and 0.03 ± 0.01 at RHs of 22, 58, and 92%, respectively. The dependence of HO2 uptake on RH by levoglucosan and PSL particles is discussed.
Molecular alignment of polymer liquid crystals in shear flows. 2. Transient flow behavior in poly(benzyl glutamate) solutions

Flow birefringence experiments are confined to the low shear rate regime in which it is known that such solutions exhibit director tumbling. The optical results exhibit characteristics common to poly(benzyl glutamate) solutions, including oscillatory responses that scale with shear strain and relaxation process that scale inversely with the previously applied shear rate. The measured degree of orientation is compared with the transient predictions of the linear Larson and Doi tumbling polydomain model. The results reveal some shortcomings of the model regarding its predictions of molecular orientation
Rapid and high-density covalent immobilization of Rhizomucor miehei lipase using a multi component reaction: application in biodiesel production

Aldehyde-functionalized silica and silica nanoparticles (SBA-15) were prepared as a matrix system for enzyme immobilization. Immobilization of Rhizomucor miehei lipase (RML) on these supports was performed via a multicomponent reaction under extremely mild conditions (25 °C, pH 7). Investigation on the mechanism of this reaction confirmed the Ugi four-component immobilization approach. The loading capacity of the supports and specific activity of the immobilized derivatives were interestingly improved. The results revealed very rapid immobilization of 10 and 60 mg of RML on 1 g of aldehyde-functionalized silica and SBA-15 after 10 and 30 minutes, respectively. Leaching experiments were performed by incubation of the immobilized derivatives in 1 M NaCl solution. The lack of the free lipase in the solution confirmed the covalent nature of the linkage. The thermal stability and co-solvent stability of the derivatives in the presence of three polar organic solvents (1-propanol, 2-propanol and dioxane) were greatly improved compared to the soluble enzyme. Both the derivatives were also used to catalyze the transesterification of colza oil with methanol to produce fatty acid methyl esters (FAMEs). In the case of RML immobilized on SBA-15 (SBA-RML), the presence of 40% of tert-butanol (v/v) as solvent in the reaction medium largely improved the conversion yield.
Size- and Shape-Controlled Magnetic (Cr, Mn, Fe, Co, Ni) Oxide Nanocrystals via a Simple and General Approach

A general, reproducible, and simple strategy using generic chemicals is introduced for controlling the size, shape, and size distribution of oxide nanocrystals. The reaction system was generally composed of the metal fatty acid salts, the corresponding fatty acids, and a hydrocarbon solvent. The method is based on the pyrolysis of metal fatty acid salts, the most common metal compounds compatible with nonaqueous solutions. Synthesis of nearly monodisperse Fe3O4 nanocrystals in a large size range (3−50 nm) was developed as the model system. The method was further applied for the growth of oxide nanocrystals of the other magnetic metals in the fourth rowCr2O3, MnO, Co3O4, and NiO nanocrystals. The size and shape control of the nanocrystals were achieved by varying the reactivity and concentration of the precursors. The reactivity was tuned by changing the chain length and concentration of the ligands, the fatty acids. Alcohols or primary amines could be used as the activation reagents when a given metal fat.
Estimation of shortwave solar radiations in the Arabian Peninsula: a new approach

AbstractIdentifying the shortwave solar radiation, Rs, is very important in various fields of science which is calculated by mathematical models if not measured experimentally. These models depend on the coastality factor, kr. Several equations are developed to calculate kr but with errors of estimation. The aim of this paper was to develop a local formula to calculate kr from temperature range. Based on the 30-year climate data for 29 weather stations throughout the Kingdom of Saudi Arabia (KSA), monthly temperature ranges were calculated. The hyperbolic equation was derived based on the best-fit analysis and the resulted errors of four statistical parameters were compared with any other established formula. The average of the absolute percent error was estimated as 2.1% as compared with 6–11% of the various published models. Results show that kr is inversely proportional to the distance from the coast and the altitude. In addition, it was found that urbanization has a considerable effect on kr and the n.
Ornstein–Zernike Relation and Percus–Yevick Approximation for Fluid Mixtures

A transformation of the Ornstein–Zernike relation for fluid mixtures is derived which involves the direct and indirect correlation functions only over the ranges within which the former are nonzero. Also, two closed expressions for the compressibility pressure in the Percus–Yevick (PY) approximation for mixtures are presented. The analytic solution of the PY approximation for mixtures of hard spheres follows immediately, and it is expected that the results should be of use in numerical calculations for systems with short‐range forces, where the direct correlation functions normally tend rapidly to zero with increasing particle separation.
Synthesis and Crystal Structure of Lanthanide Orthoniobates Studied by Vibrational Spectroscopy

RENbO4 (RE = La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu) materials were synthesized by solid-state reactions and then systematically investigated by vibrational spectroscopy. Single-phase materials were obtained at optimized temperature and time conditions, which were probed by X-ray diffraction and Raman scattering. Vibrational spectroscopy was employed to investigate the crystal structure of the lanthanide orthoniobate series by using different excitation lines in the visible region and also infrared techniques. All RENbO4 ceramics exhibited a monoclinic structure, space group C2/c = C2h6 (No. 15), with Z = 4. Raman spectroscopy evidenced 18 modes whose symmetries could be discerned by using polarized scattering, in perfect agreement with group theoretical calculations. The wavenumbers of the active-bands presented generally a decreasing tendency for increasing RE ionic radii, as a consequence of the lanthanide-induced lattice expansion. Fourier-transform infrared spectroscopy was employed t.
Catalytic modification of pyrolysis products of nitrogen-containing polymers over Y zeolites

Pyrolysis products of nitrogen-containing polymers have been transformed at 500 °C over NaY and ultra stable HY (HUSY) zeolite on-line and analysed by gas chromatography/mass spectrometry. HUSY was found to be an effective catalyst converting nitrogen-containing compounds into a series of well-defined aromatic hydrocarbons. Almost all nitrogen-content of the pyrolysis oils including amines, amides and nitriles have been successfully eliminated over HUSY; only traces of aliphatic nitriles in the range of 3–8 carbon atoms still remained in some of the pyrolysis oils. The uniform composition of the converted pyrolysis oil offers the possibility to gain pure aromatic feedstock from plastics waste. NaY proved to be an effective catalyst for cracking the heavy oil components of polymer pyrolysates to gases and to compounds of gasoline volatility, nevertheless it was not active for denitrogenation. Thermal treatment of deactivated zeolite has been carried out to study catalysts regeneration. By means of regeneration at 500 °C in air flow for 8 hours the activity of NaY has been completely recovered, while in the case of HUSY a slight decrease of activity was observed after the same treatment.
Gas adsorption in single-walled carbon nanotubes studied by NMR

Adsorption isotherms of methane and ethane in single-walled carbon nanotubes (SWNTs) were measured by 1 H nuclear magnetic resonance (NMR) at room temperature. It is shown that the interior of SWNTs becomes available formethane and ethane adsorption after cutting of SWNTs. Such endohedral adsorption dominates methane and ethane adsorption in SWNTs, at least below 1 MPa. The average exchange time between molecules adsorbed inside SWNTs and free gas molecules outside was estimated to be on the order of 80 ms. It is shown that exposure to oxygen has no effect on methane and ethane endohedral adsorption in SWNTs, suggesting that the adsorption energy of oxygen molecules inside SWNTs is small compared to that of methane. 1 3 C NMR indicates that under atmospheric pressure and room temperature helium atoms could access the interstitial sites of SWNT bundles whereas H 2 , CO 2 , and N 2 molecules could not.
Partitioning of Substituted Phenols in Liposome−Water, Biomembrane−Water, and Octanol−Water Systems

The effect of pH, ionic strength, and compound concentration on the liposome−water distribution ratio has been investigated for 20 chloro- and nitrophenols covering a wide range of acidities and hydrophobicities. A comparison with membrane vesicles from Rhodobacter sphaeroides shows that liposomes composed of zwitterionic phosphatidylcholine are appropriate model systems for mimicking the biomembrane−water partitioning behavior of all phenol species, i.e., neutral phenol, charged phenoxide, and ion pair. At high phenoxide concentrations, the simple partition model includes an electrostatic term for the buildup of a surface potential on the liposomes due to sorbed phenoxide. The distribution ratios of the neutral phenol species are very similar in the octanol− and the liposome−water system, but the charged phenol species partition significantly better into the anisotropic lipid bilayer than into the bulk phase octanol. The liposome−water distribution ratio is a more suitable descriptor for the uptake of a .
Phosphate absorption of intact komatsuna plants as influenced by phosphite

Abstract Phosphite (PO4 3-; Pi) uptake in cell suspension culture, information on how Phi affects the Pi uptake of intact plants remains to be determined. The present study was conducted to investigate the effect of Phi on Pi absorption of intact komatsuna plants (Brassica rapa var. peruviridis cv. Ajisai) in hydroponic culture. Phosphite markedly decreased Pi absorption of the intact komatsuna plants under both low (0.05 mmol L−1) and high (0.5 mmol L−1) Pi supply, although the growth (both shoots and roots) and water uptake of the high Pi-supplied plants was not affected by Phi. The inhibiting effect of Phi was small at 0.2 mmol L−1, but became large at 2 mmol L−1. Using relatively large seedlings (28 days old) to better assess the influence of Phi on Pi absorption early in the treatment, the results indicated that there was an immediate decrease in Pi absorption within the first 2-day period of Phi treatment when the water absorption of the plants was not affected. Taken together, the results suggested that there was a strong inhibiting effect of Phi on Pi uptake of intact komatsuna plants and this effect is exerted most likely by competition between Phi and Pi at uptake level. We speculate that the application of Phi to plant roots in an environment that is unfavorable for Phi-to-Pi conversion (e.g. hydroponic culture) may need to increase the amount of required Pi fertilization of plants to compensate for the reduction in Pi uptake by Phi. Further research is needed to confirm our results.
Open Photoacoustic Cell: Applications in Plant Photosynthesis Studies

Abstract In this article, we review the applications of the open photoacoustic cell (OPC) technique in studies of photosynthetic activity in plant leaves. The ability to perform in vivo and in situ measurements makes this technique particularly suitable for monitoring photosynthesis of plants subjected to specific treatments. Therefore, our objective in the present article is to describe, in more detail, the principles of the OPC technique and to follow the historical path of its applications related to the study of plants and photosynthesis, including recent results. It will be shown that the technique has been used to observe spectroscopic responses to herbicide application and to soil toxicity, in the study of photosynthesis induction, gas exchange, photochemical loss, photoinhibition, photosynthesis saturation, and photosynthetic responses to changes in parameters such as temperature, atmospheric conditions, and nutrient availability. Recent results have demonstrated its usefulness in the determination of the action spectrum directly from oxygen evolution measurements.
Self consistent Ornstein–Zernike approximation compared with exact results for lattice gases in one and two dimensions

We evaluate numerically results for the self consistent Ornstein–Zernike approximation (SCOZA) for the Ising model or the lattice gas in one and two dimensions where exact results are known. The cases we consider thus include the Ising model with nearest-neighbor interaction in two dimensions, and in one dimension the cases with a Kac interaction or exponential potential in the infinite range limit and the one with nearest- and next-nearest neighbor interactions. As earlier found for the three-dimensional Ising model, results with high general accuracy are found, although the phase transition of the two-dimensional Ising model is smeared out a bit, as SCOZA at least in its present form, does not yield a phase transition in two dimensions. In the two-dimensional case more long- range interactions are also considered to see to what extent SCOZA approximates the expected universal critical behavior. By extrapolation we find our numerical results quite consistent with a value near the exact one γ=1.75 for the.
Screening of antimicrobial activity and phytochemical analysis of Caesalpinia sappan L.

Present study deals with the antimicrobial activity and phytochemical analysis of CaesalpiniasappanL. Antimicrobial activity of C. sappanwas analyzed by using Well Diffusion (WD) and Disc Diffusion (DD) methods. Antimicrobial activity was analyzed using crude extract of C. sappanprepared by using various solvents such as methanol, ethanol, acetone, chloroform and petroleum ether against various microorganism such as Escherichia coli, Bacillus cereus, Enterococcus faecalis, Bacillus subtilis, Klebsiella pneumonia. Phytochemical analyses were carried out for most potent methanol, ethanol and acetone extract of C. sappanusing standard assays. Out of the various selected extracts, methanol, ethanol and acetone extracts showed effective antimicrobial activity against the bacteria. Petroleum ether extract of the plant showed no significant zone of inhibition against the bacteria. The phytochemical analysis of C. sappan showed the presence of flavonoids, phenolic compounds, tannins, saponin, protein, oxalic acid, carbonate, oil and fat which also exhibited the presence of antimicrobial activity. These results were confirmed using the Thin Layer Chromatography (TLC).
Compilation of the Static Dielectric Constant of Inorganic Solids

This compilation contains values of the static dielectric constant of more than 300 inorganic solids. The temperature and frequency of the measurements are listed and the magnitude of the loss tangent is indicated if known. For ninety materials — including most ferroelectrics and antiferroelectrics and several oxides and halides — additional information is presented in the form of graphs depicting the temperature dependence of the dielectric constant. In a few cases the frequency and pressure dependences are also shown. The basic principles and formulas pertinent to the field of dielectrics are reviewed in a short introduction. This part also mentions several measuring techniques and indicates the criteria used for data selection.
Influence of plasma treatment on the molar mass of poly(ethylene terephthalate) investigated by different chromatographic and spectroscopic methods

The influence of different types of low and atmospheric pressure plasma on poly( ethylene terephthalate) (PET) has been studied in terms of changes in molar mass and molar mass distribution. Apart from a variation of plasma gases (oxygen, helium) different types of plasma ( microwave, radio frequency, corona discharge ) were used for the plasma surface modification. The changes in molar mass and types of functional end groups of lower molar mass products were investigated by means of matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOFMS), whereas the high-molar mass fraction was analyzed by means of size-exclusion chromatography (SEC). The formation of crosslinked products during exposure to a helium plasma, which emits preponderately energy-rich and intense ultraviolet radiation, was proved by means of thermal field-flow fractionation (ThFFF). This method combined with a multiangle laser light scattering (MALLS) detector allows detection of weakly crosslinked polymers and microgels.
Naturally occurring, optically driven, cellular rotor

We report the conversion of optical energy into mechanical energy by naturally occurring red blood cells (RBCs) placed in an optical trap. A trapped RBC undergoes folding due to the elastic nature of its cell membrane. On use of circularly polarized light in the trap, the folded RBCs rotate, indicating their birefringence. The cellular rotation speed depends on the size of the blood cells and on laser power. Rotating RBCs have implications for naturally occurring, optically driven, rotary micromachines.
Exploring the Effects of Nanostructured Particles on Liquid Nitromethane Combustion

Monopropellants consisting of liquid nitromethane and high-surface-area particles of silicon- and aluminum-based oxides were examined to determine the effects of low concentrations of nanostructured materials on deflagration processes. The combustion rates were characterized by measuring linear burning rates in a large pressure vessel filled with argon. Results showed that nitromethane burning rates may be increased at lower pressures with dilute additions of particles. Increases in nitromethane burning rates of greater than 50 % were found with less than 1.0 wt% of particle addition at a nominal pressure of 5.24 MPa. The particle additions were estimated to have only small effects on the equilibrium flame temperatures, density, viscosity, and specific heat. Nitromethane with particle additives displayed a lower burning-rate equation pressure exponent (i.e., reduced pressure sensitivity), which was inversely proportional to particle concentration. Above a pressure of approximately 9 MPa, up to the maximum test pressure (∼14 MPa), the particle additives did not affect the nitromethane burning rate. Condensed-phase temperature profiles of the deflagrating fluid, surface tension, and fluid thermal conductivities were measured in order to elucidate some of the mechanisms causing enhanced burning rates at lower pressures.
EFFECT OF PETUNIA STOCK PLANT NUTRITIONAL STATUS ON FERTILIZER RESPONSE DURING PROPAGATION

Fertilization strategies during stock plant and cutting production are linked in terms of cutting nutrient levels and quality. Objectives were to evaluate (1) the effect of stock plant nutrition on tissue nutrient concentration and growth during vegetative propagation and (2) response to fertilizer during propagation for cuttings with 4 different initial tissue nutrient concentrations. ‘Supertunia Royal Velvet’ petunia stock plants were grown under constant fertigation of 0, 50, 100 or 200 mg nitrogen (N). L−1 for 21 days. The 200 mg N.L−1 solution contained 150 nitrate (NO3-N), 50 ammonium (NH4-N), 24 phosphorus (P), 166 potassium (K), 40 calcium (Ca), 20 magnesium (Mg), 0.7 sulfur (S), 1.0 iron (Fe), 0.5 manganese (Mn), 0.5 zinc (Zn), 0.24 copper (Cu), 0.24 boron (B), and 0.1 molybdenum (Mo). Providing a complete fertilizer during propagation of petunia, beginning immediately after sticking of cuttings, reduces the risk of nutrient deficiency. Particularly in situations where fertilizer is not applied early during propagation, stock plants should be managed to ensure unrooted cuttings have adequate nutrient reserves.
Influence of humidity on current waveform and light emission of a low-frequency discharge controlled by a dielectric barrier

The aim of this work is to determine the effect of humidity on a silent discharge in air. A point to plane configuration has been used. Current and emission spectra of the discharge have been recorded in dry and humid air for short and long inter-electrode gaps and with the plane electrode coated by a silicone rubber plate alone or under a polypropylene film. Results show the typical corona discharge regimes. For a long gap, humidity decreases the number of breakdown streamer pulses. For a short gap, the behavior observed depends on the surface conduction of the dielectric in contact with the discharge. These results show that the presence of humidity in the discharge cell not only modifies the gas but also the surface states of the dielectrics coating the electrodes. The surface charge decay appears as a major parameter, since it is related to the local field value which results from the applied field and the reverse field induced by charge accumulation during previous discharges.
Uptake of polonium and sulfur by bacteria

Elevated concentrations of polonium‐210, the last radioactive member of the 238U decay series, have been reported for groundwater in a number of shallow wells from the Central Florida Phosphate District. The 210Po must originate either directly from the naturally occurring phosphate rock of the area or from phosphogypsum, a byproduct of the wet‐process manufacture of phosphoric acid. Phosphate rock is characterized by relatively high levels of uranium and daughter products, while phosphogypsum contains high 226Ra, 210Pb, and 210Po. We assessed the potential of a bacterial isolate to remove and incorporate dissolved polonium from solution by conducting comparative radiotracer experiments using 35SO4 and 208Po. Since the observed chemical concentration of Po in these wells is too low to serve in any direct metabolic function, it was suspected that it might be cometabolized as a sulfur analogue. Our experiments were designed to (1) evaluate the rate of 33SO4 and 208Po uptake as a function of bacterial growth.
The Corrosion Resistance of Worn Tin‐Nickel and Gold‐Coated Tin‐Nickel Alloy Electrodeposits

The corrosion resistance of electrodeposited tin‐nickel alloy is due to a thin passive film, believed to be mainly tin oxide with some tin and nickel hydroxides. Thin electrodeposited gold on tin‐nickel also is corrosion resistant and is of interest as an electric contact material. Presumably, a similar protective film forms on the tin‐nickel layer exposed at pores in the gold. These observations have been made with deposits of both single phase and multiphase mixtures of , , and . The protective film can be removed by mechanical wear but will spontaneously reform, taking approximately 1500 hr in air at room temperature to reach a limiting thickness. However, the resistance of tin‐nickel to many corrodents is restored in less time, after only a few days of aging. Similar observations of the development of passivity were made with freshly plated tin‐nickel deposits on copper, with aged deposits on copper that were chemically etched immediately before exposure, and with newly fractured edges of tin‐nickel electroforms. If the substrate is exposed by wear‐through or by brittle fracture of tin‐nickel the corrosion resistance of the material is determined by the substrate, and may not be restored by aging.