Miracle-dz/UniFAR-FTUs huggingface dataset:
Simultaneous Determination of Dipyrone and Papaverine in Pharmaceutical Formulation using PLS Regression and UV Spectrophotometry

Abstract A combination of sodium dipyrone and papaverine hydrochloride is used as an analgesic and antispasmodic drug. A simple and rapid procedure is proposed for simultaneous determination of these drugs in commercial formulations (Melpaz®) based on partial least squares (PLS) regression and UV spectrophotometric measurements in the range of 218–300 nm. The calibration set was built with 25 solutions in concentrations ranging from 15.0–35.0 mg ml−1 for dipyrone and from 0.5–1.5 mg ml−1 for papaverine in methanol. The relative standard deviation (RSD) was 1.05% for dipyrone and 1.55% for papaverine in pharmaceutical formulations. The percent of relative recovery was 95.9% for dipyrone and 95.2% for papaverine. Figures of merit, such as accuracy, precision, sensitivity and adjust were also determined. The methodology was validated by using an independent method, based on high performance liquid chromatography (HPLC).
Molecular dynamics of homogeneous nucleation in the vapor phase. I. Lennard-Jones fluid

Molecular dynamics computer simulation was carried out to investigate the dynamics of vapor phase homogeneous nucleation at the triple point temperature under supersaturation ratio 6.8 for a Lennard-Jones fluid. To control the system temperature, the 5000 target particles were mixed with 5000 soft-core carrier gas particles. The observed nucleation rate is seven orders of magnitude larger than prediction of a classical nucleation theory. The kinetically defined critical nucleus size, at which the growth and decay rates are balanced, is 30–40, as large as the thermodynamically defined value of 25.4 estimated with the classical theory. From the cluster size distribution in the steady state region, the free energy of cluster formation is estimated, which diminishes the difference between the theoretical prediction and the simulational result concerning the nucleation rate.
Lanthanide‐doped TiO2 nanoparticles–modified electrode for photoelectrocatalytic degradation of dye

Lanthanide‐doped TiO2 nanoparticles (La‐TiO2NP)‐modified electrode was successfully prepared by the sol–gel and dip‐coating methods on the indium tin oxide electrode. Scanning electron microscopy, X‐ray photoelectron spectroscopy, X‐ray diffraction, and photoluminescence spectra were used to characterize its structure and composition. The degradation efficiency of methyl orange could be increased by 26.17% with the La‐TiO2NP‐modified electrode compared with that using the pure TiO2NP‐modified electrode under applied voltage of 0.3 V with illumination. The as‐prepared electrode also exhibited good repeatability and reproducibility. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 302‐306, 2013
Sum rules and the photoabsorption cross sections of C60

The absolute photoabsorption spectrum of C60 is constructed from experimental data, by linking relative measurements to some recent absolute determinations. Sum rule analysis supports these recent determinations over earlier ones, but substantially better agreement is achieved with ∼20% reduction in the cross-sections. Attention is focused on the 11–40 eV region, where discrepancies exist in both pseudophotoabsorption and photoionization data. Some inferences are drawn regarding the propensity of large molecules such as C60 toward multiple ionization, rather than photodissociative ionization. Problems encountered with prior application of quasi-equilibrium theory to the dissociative ionization of C60 are discussed.
Compact multilaser TDLAS for trace gas flux measurements based on a micrometeorological technique

A novel Tunable Diode Laser Absorption Spectrometer has been developed for trace gas flux measurements based on micrometeorological techniques. Up to 2 different species can be measured simultaneously with high temporal resolution (< 1 sec) using individual lead-salt diode lasers. The instruments response time is ultimately determined by the gas exchange time through the compact multi-reflection cell (Aerodyne Model AMAC-36 Astigmatic Herriott Cell, 0.3 l volume, total path 36 m). The lasers are operated in a time multiplexed mode using a novel modulation scheme, which combines laser operation in a pulsed-current mode with a combination of rapid scanning and two-tone frequency modulation. The latter has the potential to improve the signal-to-noise ratio of phase-sensitive detection when compared to standard lock-in techniques because of the reduction of instrument noise at higher detection frequencies. The stability and the detection limit of the instrument will be characterized. It has been used to measure CH4 and N2O fluxes via the eddy covariance technique from rice paddies and tropical ecosystems during two recent field campaigns.
Synthesis and characterization of nanoscale biomimetic polymer vesicles and polymer membranes for bioelectronic applications

An amphiphilic ABA triblock copolymer was synthesized using poly(2-ethyl-2-oxazoline) (PEtOz) as hydrophilic block [A] and poly(dimethylsiloxane) (PDMS) as hydrophobic block [B]. The cationic ring-opening polymerization of 2-ethyl-2-oxazoline was initiated by benzyl chloride in the presence of NaI. PEtOz–PDMS–PEtOz was characterized in aqueous solution using transmission electron microscopy (TEM). The block copolymers formed vesicles with a [B] block hydrophobic component thickness of 4 nm, which is thin enough for successful reconstitution of proteins. The mean diameters of the vesicles were measured to be in the range of 150–250 nm, with a narrow distribution. The electrochemical properties of planar PEtOz–PDMS–PEtOz membrane films spread across a Teflon aperture were investigated by electrochemical impedance spectroscopy (EIS). The impedance data showed an increase of planar membrane capacitance (CMEM) from 2.58 × 10−7 to 2.71 × 10−7 F cm−2 and a decrease of membrane resistance (RMEM) from 12 to 10.8 Ω cm2. The increase of CMEM over time in buffer solution can be explained by an increase of the dielectric constant as a result of membrane electrolyte incorporation and/or by the formation and growth of defect in the free-standing films. In contrast to the formation of thin-walled vesicles, the spread triblock copolymer formed a free-standing membrane with a 9 nm thickness. Based on the two possible conformations (bridge midblock conformation and loop midblock conformation) that the triblock copolymer can have, we can conclude that PEtOz–PDMS–PEtOz formed 4 nm thick polymer vesicles with intercalated loop midblock structure in aqueous solution, while 9 nm thick free-standing polymer films with bilayer loop midblock conformation or with bridge midblock conformation were formed by aperture spreading.
Direct Partial Oxidation of Natural Gas to Liquid Chemicals : Chemical Kinetic Modeling and Global Optimization

The direct homogeneous partial oxidation of methane to methanol is investigated through modeling and a limited set of experiments. The experiments are conducted in a laminar flow quartz reactor at 100 bar and 598−763 K under undiluted conditions. The modeling is performed with a detailed chemical kinetic model, previously validated against a range of high-pressure data on oxidation of CO/H2 and small hydrocarbons. Modeling predictions compare well also with the experimental data obtained in the present study. On the basis of the chemical kinetic modeling, the effect of the main process parameters is discussed and the process is optimized, using a numerical global optimization methodology based on interval analysis. The experimental data, as well as the optimization results, indicate yields of methanol in the upper range of those reported in literature. However, the values are well below the commercial target.
Recent Development in Clay Based Functional Coating for Corrosion Protection

There is a large variety of techniques available to protect metals from various types of corrosion. Till date chromate containing metal coatings is one of the most commonly used methods. Layered clays are basically of two types depending on the type of ion exchange capacity. In the recent years different researchers demonstrated the use of such cation/ anionic clays as potential nanocontainers for the inhibitors. These nanocontainers can be used in the coating to induce self-repairing capacity when the coating surface is damaged. Due to the disturbance in the pH and availability of chloride ions clay based nanocontainers can release the inhibitor to protect the surface. In the recent year use of anionic clay like hydrotalcites or layered double hydroxides are much studied in comparison to cationic clay like montmorillonite. This review critically analysed the potential of these clay in the future development of self-healing coating.
Review of the use of mesoporous silicas for removing dye from textile wastewater

The textile industry is a major user of dyes and hence an important source of water pollution, which poses a threat to aquatic as well as human life. Adsorption is a widely used technique for separating and removing dye from wastewater. Recently the use of mesoporous silica (MPSs) as an adsorbent in wastewater treatment has received considerable attention. MPSs are emerging as potential adsorbents because of their surface area, tunable and uniform pore structure, high pore volume, ordered pore structure, thermal and mechanical stability, and extraordinarily wide possibilities for functionalization to increase their adsorption capacity. In this paper the ability of MPSs to absorb dyes from aqueous solutions is reviewed. This article provides information on adsorption studies carried out under different operational conditions such as contact time, solution pH, temperature, agitation speed, etc. This review also summarizes and attempts to compare the equilibrium isotherm and kinetic models, and the thermodynamic studies that report the adsorption of dyes onto MPSs. The literature reviewed, indicate that SBA-MPSs have a higher adsorption capacity than MCM-MPSs and functionalized MPSs a better adsorption capacity than MPSs. It is evident from the literature that the potential of MPS based nano-sorbents being used for removing dyes from aqueous solution is very high. However, still more research work is needed on developing cost effective and more efficient MPS based nano-sorbents for use commercially.
Molecular dynamics analysis of diffusion of point defects in GaAs

Molecular dynamics simulation was carried out to estimate the diffusion coefficient and the mechanism of diffusion with a constant pressure and temperature algorithm. The following results were obtained: (i) there is little diffusion of a vacancy in solid GaAs, even near the melting point. (ii) the diffusion coefficient of an interstitial arsenic atom is larger than that of an interstitial gallium atom, (iii) after formation of a dumbbell pair in the [110] direction, an interstitial arsenic atom migrates in the [110] direction, while an interstitial gallium atom migrates in either the [110] or [-110] direction, and (iv) an interstitial arsenic atom pushes out a substitutional arsenic atom and then diffuses by an interstitialcy mechanism, while an interstitial gallium atom pushes out either a substitutional arsenic or gallium atom. Finally, all of migrating interstitial atoms in solid GaAs switch to interstitial arsenic atoms at the final stage of diffusion.
Rapid Quantification of Valsartan in Human Plasma by Liquid Chromatography using a Monolithic Column and a Fluorescence Detection: Application for Pharmacokinetic Studies

A rapid high-performance liquid chromatographic (HPLC) method using a monolithic column has been developed for determination of valsartan in human plasma. The assay is based on protein precipitation using acetonitrile and fluorescence detection. The assay enables the measurement of valsartan for therapeutic drug monitoring with a minimum quantification limit of 20 ngml-1. The method involves simple, one-step extraction procedure and analytical recovery was nearly complete. The separation was carried out in reversed-phase conditions using a Chromolith Performance (RP-18e, 100×4.6 mm) column with an isocratic mobile phase consisting of 0.01 M disodium hydrogen phosphate buffer-acetonitrile (60:40 v/v) adjusted to pH 3.5 with diluted phosphoric acid. The excitation and emission wavelengths were set at 230 and 295 nm, respectively. The calibration curve was linear over the concentration range 20-2000 ngml-1. The coefficients of variation for inter-day and intra-day assay were found to be less than 6%. The assay was applied for the analysis of blood samples from a pharmacokinetic study.
Trigol based reduction of graphite oxide to graphene with enhanced charge storage activity

A triethylene glycol (trigol) based simple approach is reported for the reduction of graphite oxide (GO). This protocol produces high quality graphene which we term as trigol reduced graphene (TRG) and its relevant properties including electrical conductivity and energy storage capacity are comparable to those of graphene obtained by the conventional hydrazine based approach. The achieved specific capacitance for TRG is 130 F g−1 with an energy density value of 18 W h kg−1. This work opens up a new promising synthetic route for the development of graphene and graphene based nanocomposites for various energy related applications.
High-speed multilayer film assembly by alternate adsorption of silica nanoparticles and linear polycation

QCM showed that SiO2/poly(diallyldimethylammonium chloride) (PDDA) film assembly could be achieved in 2 s for 45 nm silica nanoparticle monolayers and 20 s for PDDA monolayers, with film integrity demonstrated by SEM and spectroscopic ellipsometry.
A simple model of oxygen diffusion out of the retinal artery

The purpose of this study is to explore the possibility that oxygen (O2) diffusion out of the retinal artery (RA) can explain the observed significant (P<0.001) decrease of oxygen saturation (O2Sat) in RA as intraocular pressure (IOP) is raised from 10 to 55 mmHg. Hyperspectral image data from normal monkeys' optic nerve head (ONH) and overlying retinal blood vessels were recorded at IOP settings of 10, 30, 45 and 55 mmHg. Average percent O2Sat values of the RAs were found from the recorded blood spectra by comparing to reference spectra from saturated and desaturated red cell suspensions. Percent O2Sat of the RAs was 78.9% at IOP of 10 mmHg. This decreased to 74.1% at 45 mmHg (P=0.01); and further decreased to 51.5% at IOP = 55 mmHg (P<0.0001). To interpret these results, we developed a simple diffusion model assuming that the RA is surrounded by tissues in equilibrium with venous oxygen tension (PO2). O2 flux across the arterial wall was calculated by Fick's law. The percentage of O2 diffusing out of the RA were 0.6% at IOP of 10 mmHg, and 38% at IOP of 55 mmHg. Confirmation still requires measurement of blood velocity.
Principal Components Analysis as a Tool to Summarise Biotransformation Data: Influence on Cells of Solvent Type and Phase Ratio

The effect of some solvents, present in different amounts, upon whole cells of Rhodococcus erythropolis DCL14 carrying out the biotransformation of (−)-carveol to (−)-carvone was studied. The solvents tested were ethyl butyrate, n-hexane, cyclohexane, iso-octane, n-dodecane, dimethyl sulfoxide, bis(2-ethylhexyl) phthalate and FC-70. The volumes of each solvent corresponded to organic:aqueous phase ratios of 0.0005, 0.0025, 0.005, 0.025 and 0.2. To assess any potential solvent protection towards substrate toxicity, assays were carried out at two initial carveol concentrations (15 and 50 mM). Carvone accumulation was followed by gas chromatography. Cell viability, several aspects of cell morphology and the ability to form clusters were monitored by fluorescence microscopy. Principal components analysis (PCA) was used as a tool to explain the differences in the observations of the multidimensional data set obtained from the multiple conditions. PCA using the different volumes of each solvent as variable suggests that the variability of the observations can be summarised in six components which represent 79.4% of the variance of the data. Conversely, using cell and solvent data to perform the PCA, 97.1% of the variance of the data can be summarised in three components, the first two capturing 91.0% of the information. These components seem to represent solvent toxicity and a protective effect of the solvent from carveol toxicity.
Composting of Green Waste Shredded by a Crush/Cut Roller Versus a Low Speed Counter-Rotating Shear Shredder

Green waste was shredded at a commercial composting site by a conventional commercial low speed counter-rotating shear type shredder and an alternative shredder, a crush/cut roller mounted on and powered by a tracked excavator. Material from both shredding systems showed similar dry weight and dry bulk density patterns across a broad particle size distribution range. The crush/cut roller produced significantly different (p < 0.05) quantities of material in the 10-25 mm and 75-100 mm particle size ranges, whilst dry bulk density values were significantly different in the 16-25 mm range only. Over a three month windrow composting period, dry weight percentage and dry bulk density values from both systems tended to increase toward the lower end of the particle size range and decrease toward the higher end of the particle size range and were, with one exception, not significantly different. These values were similar in magnitude to those for material from commercial green waste composting windrows. Temperature profiles were comparable in both systems and indicated the existence of thermophilic conditions within each windrow for over 50 days, whilst product stability, as indicated by specific oxygen uptake rates, was the same for both treatments. It was concluded that any differences in particle size distribution between the two shredding systems were not important in relation to the biological aspects of the composting process. Development of a simple compost maturity test based on particle size profiling is suggested. It is proposed that the alternative, crush/cut roller, approach to green waste shredding could potentially reduce the economic threshold for organic recycling and allow many smaller communities to benefit from this environmentally sound waste management practice.
Density Functional Theory Study of Vibrational Spectra of Fluorene

Ab initio Hartree−Fock and density functional theory calculations using the 6-31G* basis set were carried out to study the molecular structure and vibrational spectrum of fluorene (FR). Two density functionals were employed: the (1) Becke−Lee−Yang−Parr (BLYP) functional and (2) the Becke 3-Lee−Yang−Parr (B3LYP) functional. Comparison of the calculated and experimental vibrational spectra reveals that the B3LYP calculations are quite accurate in predicting the vibrational frequencies and modes. We report the results of new assignments of the fundamental vibrational frequencies obtained on the basis of the calculations. The new assignments show a one-to-one correspondence between the observed and calculated fundamentals.
Electrospinning of polyvinyl butyral in different solvents

Abstract In this study we aimed at finding different solvents for PVB and determine the effect of concentration and solvents on electrospun polyvinyl butyral (PVB) nanofibers. Firstly, we solved PVB in isopropanol, n-butanol, dimethylformamide, ethanol and acetic acid in various concentrations. Later, we compared fiber characteristics for each solvent. We observed that with increasing concentration, the fiber diameter increased. Bead formation occurred in low concentrations and low viscosity of polymer solution. Each solvent has a different effect on nanofiber morphology. It is observed that fiber diameter and morphology is one of the parameters that can be controlled by solvent.
Speciation of antimony(III) and antimony(V) in seawater by flow injection solid phase extraction coupled with online hydride generation inductively coupled plasma mass spectrometry

An automated low pressure flow analysis method with online columns pre-concentration/hydride generation (HG) inductively coupled plasma mass spectrometry (ICP-MS) was developed for the simultaneous determination of Sb(III) and Sb(V) in aqueous environmental samples. For this purpose a chelating resin [1,5-bis(2-pyridyl)-3-sulfophenyl methylene] thiocarbonohydrazide immobilised on aminopropyl-controlled pore glass (550 A, PSTH-cpg) and an anion exchanger (Amberlite IRA-910) were used. A three column system was accordingly designed, using the two adsorbents in tandem, for the separation and preconcentration of the antimony species. The method was developed on the basis of selective sorption of Sb(III) on PSTH-cpg resin. After removal of Sb(III) by PSTH-cpg, Sb(V) was collected on Amberlite. The effects of chemicals and flow variables were investigated. The optimized operating conditions were: sample pH 8.4, a sample flow rate of 1.1 mL min−1, an eluent flow rate of 1.3 mL min−1, and an eluent 0.04% thiourea in 5% HNO3. The relative standard deviations (n = 10) were 4.6% for Sb(III) and 3.0% for Sb(V), demonstrating a good precision for the analysis. The enrichment factors for Sb(III) and Sb(V) were 5.5 and 3.9, respectively. Detection limits (2 min sample loading time) were 0.013 µg L−1 for Sb(III) and 0.021 µg L−1 for Sb(V). The accuracy of the proposed method was checked with two certified reference materials (CRMs): SLRS-5 River Water and TMDA-54.4 Fortified Lake Water. Values obtained were in accordance with those reported for the certified materials. Recovery was found to be in the range of 97–105% for a suite of seawater samples collected in Malaga, Spain.
Nitrogen‐use efficiency traits of mini‐watermelon in response to grafting and nitrogen‐fertilization doses

Two experiments were conducted to study the effect of grafting on nitrogen-use efficiency (NUE) in mini-watermelon plants. In the first study, mini-watermelon plants (Citrullus lanatus [Thumb.] Matsum. and Nakai cv. Minirossa) either ungrafted or grafted onto Macis, Vita (Lagenaria siceraria [Mol.] Standl.), PS1313, and RP15 (Cucurbita maxima Duchesne × Cucurbita moschata Duchesne) rootstocks grown in hydroponics were compared in terms of shoot dry biomass, leaf area, root-to-shoot ratio, SPAD index, shoot N uptake, and nitrate reductase (NR) activity 40 d after transplantation in response to nitrate concentration in the nutrient solution (0.5, 2.5, 5, 10, 15, or 20 mM of NO 3 ). In the second experiment, the suitability of a selected rootstock with high NUE (Vita) to improve crop performance and NUE of grafted mini-watermelon plants was evaluated under field conditions. In the hydroponic experiment mini-watermelon grafted onto Vita rootstock needed the lowest nitrate concentration (1.31 mM of NO3) in the nutrient solution to reach half maximum shoot dry weight. Total leaf area, SPAD index, and shoot N uptake increased in response to an increase of N concentration in the nutrient solution. At 2.5 mM NO 3 , mini-watermelon grafted on either Vita or RP15 had the highest NR activity whereas no significant difference was observed at 10 mM NO 3 . The open-field study indicated that increasing N-fertilization rates from 0 to 100kg ha–1 improved total and marketable yields of mini-watermelon plants while decreasing NUE. When averaged over N levels, the marketable yield, NUE, N-uptake efficiency, and N-utilization efficiency were significantly higher by 39%, 38%, 21%, and 17%, respectively, in Minirossa grafted onto Vita compared to ungrafted Minirossa plants. Therefore, grafting miniwatermelon plants onto selected rootstocks can be used as a quick and effective method for improving productivity and NUE.
Relative humidity, EMC, and collapse shrinkage in wood

Etude des relations entre l'humidite relative, la teneur en humidite a l'equilibre et le retrait par collapsus aux premiers stades du sechage du bois (a 40°C et 50°C). L'etude a porte sur l'aubier et le bois de cœur de Quercus, Liquidambar styraciflua, Liriodendron tulipifera, Pinus taeda et Sequoia sempervirens, pour de tres fortes valeurs d'humidite relative (90 a 100%)