Miracle-dz/UniFAR-FTUs huggingface dataset:
Extractability of Fluoride into Black Tea Liquors, Kenya

Fluoride in food is currently a subject of immense interest globally as it is directly related to health and disease. Tea leaves are rich in fluoride, part of which is released into the tea liquor during the tea making process. Therefore, the main objective of this study was to determine the levels of fluoride in tea liquors prepared from different grades of black Cut, Tear and Curl (CTC) tea sourced from various tea growing regions in Kenya as well as other tea producing countries in East Africa (Rwanda, Uganda and Tanzania). The fluoride levels in tea liquors (1 g of black tea + 100 ml of boiling distilled water agitated on a mechanical shaker for 10 minutes) were quantified to be in the range between 0.11 and 1.35 µg/ml using a simple, reliable and cheap potentiometric method by a Fluoride Ion Selective Electrode (FISE). These results confirm that tea consumption is indeed an important dietary source of fluoride. Also, these data demonstrate regional variations in the fluoride contents as tea liquors of the black CTC tea samples from different regions varied widely in terms of their fluoride contents.
Synthesis of selectively 15N-labeled 2"-O-{[(triisopropylsilyl)oxy]methyl}(=tom)-protected ribonucleoside phosphoramidites and their incorporation into a bistable 32mer RNA sequence

We present optimized reaction conditions for the conversion of 2'-O-{[(triisopropylsilyl)oxy]methyl}(tom) protected uridine and adenosine nucleosides into the corresponding protected (3-15N)-labeled uridine and cytidine and (1-15N)-labeled adenosine and guanosine nucleosides. On a DNA synthesizer, the resulting 15N-labeled 2'-O-tom-protected phosphoramidite building blocks were efficiently incorporated into five selected positions of a hairpin bi-stable 32mer RNA sequence. By 2D-HSQC and HNN-COSY expts. in H2O/D2O 9:1, the 15N-signals of all base-paired 15N-labeled nucleotides could be identified and attributed to one of the two coexisting structures of 32mer RNA sequence. [on SciFinder (R)]
Photoconductive bismuth sulphide thin films by chemical deposition

A chemical bath deposition technique for obtaining photoconductive grade bismuth sulphide (Bi2S3) thin films of thickness approximately=0.05 to 0.3 mu m is described. These films show a photo-current to dark-current ratio of 100-500 and photoconductivity of approximately=1 Omega -1 cm-1 at 25 degrees C, under 1200 W m-2 tungsten-halogen illumination. Air annealing in the 100-250 degrees C range can drastically affect the photocurrent response of these films. The dark conductivity of the films can be increased by a factor of approximately=107 during such an annealing process. This suggests the possibility of post-deposition processing of the films for specific optical and optoelectronic applications.
Output Flow Determination of Reverse Flow Diverters in Reverse Flow Mode Based on Pressure Data

The key fluidic component of a pneumatic pulse jet pump is a reverse flow diverter (RFD), which consists of a driving nozzle and diffuser, with a suction gap separating the two. Because the suction gap is open to the storage tank, the mass flow through a RFD is not constant, and it is difficult to determine its pumping capacity in the reverse flow mode. For symmetrical RFDs, we experimentally investigated the effects of the driving nozzle exit diameter d0, suction gap length dc, liquid viscosity μ, and pipeline load impedance on the RFDs’ performance in the reverse flow mode. A dimensionless performance curve insensitive to d0, dc, μ, and the pipeline load impedance was found based on these experimental data. The output flows of RFDs with suction factors higher than 0.9 could be determined using this dimensionless performance curve.
A delayed nonlinear stochastic model for cocaine consumption: Stability analysis and simulation using real data

In this paper we propose a stochastic mathematical model with distributed delay in order to describe the transmission dynamics of cocaine consumption in Spain. We investigate conditions to guarantee the stability in probability of the equilibrium points under stochastic perturbations via the white noise processes. The results are applied to the model cocaine consumption using data retrieved from the Spanish Drug National Plan, http://www.pnsd. mscbs.gob. es/ . The obtained results may be useful for policy health authorities in order to improve the strategies against the drug consumption in the long-run.
Viscosity, Density, and Speed of Sound for the Binary Mixtures of Formamide with 2-Methoxyethanol, Acetophenone, Acetonitrile, 1,2-Dimethoxyethane, and Dimethylsulfoxide at Different Temperatures

Densities and viscosities of binary liquid mixtures of formamide with 2-methoxyethanol, acetophenone, acetonitrile, 1,2-dimethoxyethane, and dimethylsulfoxide have been measured at (298.15, 308.15, and 318.15) K and over the entire composition range at p = 0.1 MPa. Ultrasonic speeds of these binary liquid mixtures have also been measured at 298.15 K and the same pressure. From the experimental data, values of excess molar volume , viscosity deviation Δη, and deviation in isentropic compressibility ΔKS have been determined. These results were fitted to the Redlich−Kister-type polynomial equation. The density and viscosity data have been analyzed in terms of some semiempirical viscosity models.
An investigation of the electron irradiation of carbon blacks in various gas atmospheres using a modified electron microscope

The behaviour of carbon black particles immersed in a variety of gases and simultaneously irradiated with an electron beam has been investigated. Because this treatment was performed in a modified high‐resolution transmission electron microscope, the remarkable morphological and microstructural changes that occurred could be observed directly. In addition to the physical damage to the specimens, believed to be caused by a high flux of low energy ions generated by the electron beam, the use of reactive gases in this study exposed additional chemical sputtering effects that will be of importance for future controlled‐environment microscopy.
Doping profiles characterization in GaAs semi‐insulating substrates using capacitance–voltage, conductance–voltage, and current–voltage measurements

An accurate doping profile extraction in devices fabricated in semi‐insulating GaAs substrates is difficult. The conventional Schottky barrier diode C–V technique is prone to large errors caused by bias dependent series resistance, gate current conduction, deep‐level traps, and breakdown of the depletion approximation. It is shown that using both ac admittance (G–V and C–V) and dc (I–V) measurements of Schottky barrier diode the doping profile can be extracted more accurately and the range of accurate measurements can be clearly established. The characterization procedure has been verified experimentally using devices fabricated in a commercial 1 μm GaAs process.
Spray-Drying Synthesis and Electrochemical Performance of Lithium Vanadates as Positive Electrode Materials for Lithium Batteries

Three lithium vanadate materials with the nominal composition Li 1.1 V 3 O 8 have been prepared by a spray-drying technique with subsequent heat-treatment (A) at 320°C, (B) at 585°C, and (C) at 585°C with carbon. They have been analyzed by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, electronic conductivity, Brunauer-Emmett-Teller surface-area characterization, and electrochemical charge-discharge tests in lithium cells. The best material had a spherical aggregate morphology and exhibited, at 25°C in a narrow potential range of 2.0-3.3 V vs Li/Li + , at 116 mA/g (C/3) a high discharge capacity of 260 mAh/g in the 2nd cycle and 220 mAh/g in the 60th cycle, respectively, which is to the best of our knowledge the best electrochemical performance reported so far for Li 1.1 V 3 O 8 . The rate capability of these positive-electrode materials was found to be limited mainly by the lithium diffusion length in the primary particles.
Simple Inductance Measurement Method Using a Commercial LCR Meter

A simple measurement method, which determines inductance from the capacitance standards, is presented. This method is cost effective because no special instrument other than a commercially available LCR meter is used. The measurement principle is the compensation method using the LC series circuit. At the frequency near its resonating condition, the reactance of the inductor is offset by that of the capacitor. The reactance of the capacitor was precisely calibrated beforehand, and the LCR meter measures the reactance value of the residual difference much smaller than the total reactance of the inductor itself. This means that the accuracy of LCR meter affects the measurement uncertainty of inductance less than the uncertainty of direct deflection measurement of inductance. Two 10 mH standard inductors and a 100 mH standard inductor were measured at 1592 Hz (angular frequency of ω = 104 rad/s). The relative combined standard uncertainties of measurement were estimated to be 9.2 parts per million (ppm), 9.8 ppm and 12.0 ppm, respectively. These values are small enough for the industrial use.
220 GHz low‐noise amplifier MMICs and modules based on a high performance 50 nm metamorphic HEMT technology

A metamorphic composite-channel InAlAs/InGaAs based high electron mobility transistor (MHEMT) technology has been developed for active and passive high-resolution imaging applications. The technology features 50 nm gate length in combination with an In content of 80% in the main channel and 53% in the second channel. An extrinsic transit frequency ft of 400 GHz and an extrinsic maximum transconductance gm,max of 1800 mS/mm were measured at a drain voltage of 1 V. Based on this advanced MHEMT technology, coplanar G-band low-noise amplifier (LNA) MMICs were realized, achieving a small-signal gain of more than 15 dB between 192 and 230 GHz together with an average noise figure of 8 dB. Furthermore, mounting and packaging of the monolithic amplifier chips into G-band waveguide modules was accomplished with only minor reduction in circuit performance. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Determination of the Local Temperature at a Sample during Raman Experiments Using Stokes and Anti-Stokes Raman Bands

Sample heating due to high incident laser power in Raman experiments on (industrial) polymers and catalysts can easily lead to unwanted changes in morphology or desorption of surface species. Therefore temperature of the sample at the laser spot was studied by determining Stokes and anti-Stokes Raman intensities. Temperature can normally be determined within an accuracy of about 5 K, although for samples having nothing but Raman bands above 1000 cm−1, the anti-Stokes lines are very weak and accuracy of temperature determination decreased drastically. For most of the samples studied in the macro-Raman setup, powers up to 250 m\V could be used without measurable heating. In the micro-Raman setup heating started earlier due to higher focusing.
Enantioselective extraction of mandelic acid enantiomers by L-dipentyl tartrate and β-cyclodextrin as binary chiral selectors

A new binary chiral selector system effective for the enantioselective extraction of racemic mandelic acid is presented. While L-dipentyl tartrate and β-cyclodextrin had a very low enantioselectivity as single selectors, a preferential extraction of D-mandelic acid to the organic phase was found in the binary selector system. Using decanol as organic solvent and pH of a phoshate buffer equal to 2.3, the distribution coefficients of D-and L-mandelic acids as high as 14.9 and 7.0, respectively, and the enantioselectivity value of 2.1 were found at optimum concentration of β-cyclodextrin.
Discontinuous spectrocolorimetric titration method for determining stability constants of fulvic acid{iron complexes

The stability constants for the complexes formed between iron species existing in ambient soil environment and fulvic acids (FA) extracted from organic wastes like sewage sludge, farm yard manure (FYM), poultry manure, and press mud were determined in aqueous media of pH 5·0 and 8·5 by discontinuous spectrocolorimetric titration method. The values of stability constant (log K) of Fe–FA complexes estimated at pH 5·0 were 6·026, 6·212, 6·270, and 6·342 for FYM, sludge, poultry manure, and press mud, respectively. The respective values at pH 8·5 were 6·145, 6·276, 6·350, and 6·940. The order of the values of log K for different preparations of fulvic acids was press mud > poultry manure > sludge > FYM. The functional group contents, their pH of neutralisation, and electrostatic properties of the FA such as pKINT, pKm, and 0·868 nW, were found to be the determining factors for maximum binding ability of FA for metal cations and the stability constant of Fe–FA for different FA preparations. The basic assumptions and the limitations of the discontinuous spectrocolorimetric estimation of stability constants for Fe–FA are discussed.
Effects of Particulate Matter of Various Sizes Derived from Suburban Farmland, Woodland and Grassland on Air Quality of the Central District in Tianjin, China

Poor air quality directly affects human health and has become an increasingly important environmental issue in Tianjin, China. The suspension of particulate matter (PM) in the atmosphere is not only from industrial pollutants, but also soil wind erosion; however, the contributions from farmland, woodland, and grassland have rarely been considered in this region. We conducted an assessment of PM sources through wind erosion, dust emission, and dust transportation from urban and rural areas to the central district in Tianjin, and our results demonstrated that the spatial variability of wind erosion and dust emission strongly depends on land use, particle size distribution and meteorological conditions. The equations in this study were empirical, and soil properties such as aggregation and crusting, as well as surface characteristics such as canopy height and residue cover, were not considered. The dust emission capacity of woodland and grassland was the lowest because of vegetation coverage. The values obtained in this study may overestimate emissions, because soil aggregation was not considered. The yearly dust amounts of PM15–20 (particles with aerodynamic diameter from 15 µm to 20 µm), PM10–15 (particles with aerodynamic diameter from 10 µm to 15 µm), and PM10 (particles with aerodynamic diameter less than 10 µm) from wind erosion in 2009 from the urban area in Tianjin were estimated as 5,400 t, 5700 t and 17,300 t, respectively, while those from the rural area were 14,000 t, 15,300 t and 40,700 t, respectively. The dust emission contributed from farmland accounted for 99.5%, and that from woodland and grassland only accounted for 0.5%. The PM10 transported to the central district and PM10 concentrations in the days with the 20% highest PM10 concentrations in the central district in 2009 were compared. The R 2 was 0.74, which meant the two variables were highly correlated.
Quantification of Fentanyl in Human Serum by Column-Switching Liquid Chromatography and Tandem Mass Spectrometry

Analytical methods for pharmacokinetic studies with quantification of the highly potent anaesthetic drug fentanyl in serum must be rugged, sensitive, precise and accurate. To address these analytical demands and facilitate an automated approach to sample clean-up, a new method was developed for human serum using back-flush columnswitching and high-performance liquid chromatography/tandem mass spectrometry (LC-MS/MS). Prior to injection, protein precipitation in trichloroacetic acid was performed in each sample. Samples were diluted with internal standard (D5-fentanyl) in 10% (w/v) trichloroacetic acid, kept at 4oC for 20 min and centrifuged followed by injection of 40μL supernatant onto a BioTrap 500 MS extraction column. Using a time programmed six-port valve switch, the extracted drug was back-flushed onto a Zorbax SB-Aq analytical column, gradient eluted and finally detected after electrospray ionisation with multiple reaction monitoring (MRM) of the transitions m/z 337 → m/z 188 and m/z 342 → m/z 188 for fentanyl and D5-fentanyl, respectively. Mean inter-assay accuracy (n=5) ranged from 93 to 101 % and inter-assay precision (n=5) ranged from 3.7 to 9.4% (C.V.). The method was used in a preliminary study of 4 patients after application of transdermal patches and found fully applicable for future pharmacokinetic studies. This is the first on-line, column-switching LC-MS/MS method validated and demonstrated suitable for quantification of fentanyl in human serum.
A Comparative X-ray Diffraction Study and Ab Initio Calculation on RU60358, a New Pyrethroid

The crystal structure of RU60358, C20H21NO3, has been determined using X-raydiffraction to establish the configuration and stereochemistry of the molecule around theC15-C16 triple bond. The compound crystallises in the orthorhombic space group P212121, a= 7.7575, b = 11.3182, c = 21.3529a, V = 1874.80a3 and Z = 4. The structure has beenrefined to a final R = 0.068 for the observed structure factors with I ≥ 3σ (I). The refinedstructure was found to be significantly non planar. A comparative study, using the ab initiocalculations of the structure at B3LYP/6-31G** levels of theory, shows good geometricalagreement with the X-ray diffraction data. Standard deviations between the calculated andexperimental bond values have been shown to be 0.01 a and 0.5° for bond angles.Vibrational wavenumbers were obtained from a normal mode analysis using the ab initiocalculations.
Mechanisms of interaction between very high-frequency photoacoustic waves and the skin

The aim of this work is to improve the understanding of the interaction between photoacoustic waves and skin. We employ photoacoustic waves with 1 MPa amplitude and center frequencies of 100 MHz to transiently perturb model lipid membranes and the stratum corneum of mini pigs. The lipid structure transient perturbation observed is tentatively attributed to a temperature rise mechanism. We also try to show that the dynamic acoustic radiation force mechanism can explain the perturbation induced by photoacoustic waves in skin. Indeed, 15 bar pressure gradients across 5 corneocytes (approx. 5 μm wide) are shown to transiently perturb the skin structure.
Vibrational constants and force field of sulfur hexafluoride

The infrared-active combination bands of SF/sub 6/ gas were remeasured and the band origins estimated. These data were combined with the Raman frequencies of Bosworth et al., and with the spectrum of SF/sub 6/ in cryogenic liquid oxygen solutions reported by Bertsev et al., to obtain estimates for the 21 anharmonicity constants X/sub ij/. The resulting harmonic vibrational frequencies were used in a calculation of the general quadratic harmonic force field of SF/sub 6/. The most useful constraint in the F/sub 1//sub u/ symmetry block was the Coriolis constant zeta/sub 3/ = 0.693 +- 0.004 obtained from an analysis of . nu. /sub 3/ resolved with tunable diode lasers; but zeta/sub 4/ estimated from a similar analysis of . nu. /sub 4/, and the /sup 32/S--/sup 34/S isotope frequency shifts reported by Brunet and Perez for these fundamentals, are all in general agreement. The more important valence force constants are f/sub r/ = 5.45 +- 0.03, f/sub rr/(cis interaction) = 0.36 +- 0.01, f/sub rr'/ (trans interaction) = -0.02 +- 0.03, and f/sub . cap alpha. / approximately 0.83, all in mdyn/A. From the absolute band intensities of Schatz and Hornig and the present force field, the S--F bond moment and its derivative are estimated tomore » be . mu. /sub 0/ = 2.44 +- 0.12 D and delta . mu. /delta r = 4.2 +- 0.3 D/A. « less
Oil Palm Ash/Ca(OH)2/CaSO4 Absorbent for Flue Gas Desulfurization

The preparation, optimization and activity of active absorbent prepared from oil palm ash for the removal of SO2 in flue gas from combustion systems were investigated. The absorbent was prepared from oil palm ash, calcium hydroxide and calcium sulfate using a water hydration process. A Central Composite Design (CCD) was used to study the influence of various absorbent preparation variables – hydration period, amount of oil palm ash, and amount of CaSO4 – on the BET (Brunauer-Emmett-Teller) specific surface area of the resulting absorbent. The surface areas of the absorbents obtained were in the range of 18.7–147.2 m2/g. It was found that all three absorbent preparation variables studied have a significant positive influence on the BET surface area of the resulting absorbent. An empirical model was then developed to correlate the three absorbent preparation variables to the BET surface area of the resulting absorbent. The model showed significance at a confidence level of 95 % using Analysis of Variance (ANOVA). Based on the empirical model, a maximum specific surface area of 128.6 m2/g exists within the range of the experimental variables investigated. The hydration conditions that result in the maximum surface area are a hydration period of 10 h, amount of oil palm ash 15.0 g, and amount of CaSO4 2.7 g. Experimental validations of these predicted optimum hydration conditions gave surface areas in the range of 125.9–129.5 m2/g. These results are in excellent agreement with the predicted value. In addition, desulfurization activity tests showed that the absorbent derived from oil palm ash/Ca(OH)2/CaSO4 exhibited a higher desulfurization capacity compared to its starting materials.
Application of Clay Minerals and Polymeric Resins to Remove Dissolved Microcystin-LR from Water

This study aimed to develop techniques for purification of cyanotoxins dissolved in water - particularly those produced by Microcystis aeruginosa species - using natural clay, chemically modified natural clay, commercial clay and ion exchange and adsorbent resins. Except for natural clay, chemical pre- treatment was required to increase the adsorption capacity of the treatment materials. All the clays were exposed to microcystin solutions of 0.5x10 -3 , 1.0x10 -3 and 10.0x10 -3 ? g/mL in batch purification processes. The same solutions were used in purification processes with polymeric resins packed in columns. The microcystin- LR samples were quantified using ELISA immunoassay and removal capabilities and saturation of the treatment materials were evaluated. The modified clays showed a microcystin-LR removal efficiency rate between 82.90% and 99.86%, while the resins a rate between 87.6% and 99.74%. This study shows that the materials have technologically and economically promising properties for the removal of microcystins from water.
Spectrophotometric determination of aluminium in soil extracts with xylenol orange

A spectrophotometric method for determining aluminium in soil extracts with xylenol orange at pH 3·8 is described. Various extraction reagents can be used. Interference of iron(III) and iron(II) is eliminated with EDTA. Rectilinear calibration covers a range of 0 to 60 µg of aluminium. Typical results are shown for an iron-humus podzol. Recovery of added aluminium and levels of interference of anions and cations relevant to soil analysis are shown. The practicability of the method in contrast with “lake” methods is emphasised.
Systematic Optimization of a Force Field for Classical Simulations of TiO2-Water Interfaces

Atomistic force field parameters were developed for the TiO2–water interface by systematic optimization with respect to experimentally determined crystal structures (lattice parameters) and surface thermodynamics (water adsorption enthalpy). Optimized force field parameters were determined for the two cases where TiO2 was modeled with or without covalent bonding. The nonbonded TiO2 model can be used to simulate different TiO2 phases, while the bonded TiO2 model is particularly useful for simulations of nanosized TiO2 and biomatter, including protein–surface and nanoparticle–biomembrane simulations. The procedure is easily generalized to parametrize interactions between other inorganic surfaces and biomolecules.