Miracle-dz/UniFAR-FTUs huggingface dataset:
Sphere-rod transition of micelles of tetradecyltrimethylammonium halides in aqueous sodium halide solutions and flexibility and entanglement of long rodlike micelles

Static light scattering from aqueous NaCl and NaBr solutions of tetradecyltrimethylammonium chloride (TTAC) and bromide (TTAB), respectively, has been measured at 25 °C. Spherical micelles are formed in water and in aqueous solutions with low salt concentrations. Rodlike micelles are formed above the threshold salt concentrations, which are 2.7 and 0.12 M for TTAC and TTAB, respectively, and their aggregation numbers markedly increase with an increase in salt concentration. With application of the wormlike chain model, the contour length and persistence length of long rodlike micelles of TTAB have been evaluated on the basis of simple geometrical assumptions. The same procedure has been applied for rodlike micelles of dodecyldimethylammonium chloride (DDAC) and bromide (DDAB) and cetyltrimethylammonium bromide (CTAB). Long rodlike micelles of these surfactants are flexible, but their persistence lengths for TTAB and CTAB, 51 and 47 nm, are slightly longer than those for DDAC and DDAB, 35 and 31 nm. The entanglement of long rodlike micelles at concentrations above overlap threshold micelle concentration is also discussed on the assumption that the blobs for the entangled network consisting of these micelles behave ideally. The radius of gyration of the blob of TTAB micelles is scaled for its molecular weight with the exponent, 0.54, the relation being in complete agreement with that with the exponent, 0.55, in the dilute
Reactions of aryl chlorothionoformates with quinuclidines. A kinetic study

The reactions of quinuclidines with phenyl, 4-chlorophenyl, 4-cyanophenyl, and 4-nitrophenyl chlorothionoformates (1, 2, 3, and 4, respectively) are subjected to a kinetic study in aqueous solution, at 25.0°C, and an ionic strength of 0.2 M (KCl). The reactions are studied by following spectrophotometrically the release of the corresponding phenoxide anion/phenol generated in the parallel hydrolysis of the substrates. Under amine excess, pseudo-first-order rate coefficients (kobs) are found. Plots of kobsversus [amine] are linear, with slope kN. The Bronsted-type plots (log kNvs. pKa of aminium ions) are linear, with slopes β = 0.26, 0.22, 0.19, and 0.28 for the reactions with 1, 2, 3, and 4, respectively. The magnitudes of the slopes indicate that these mechanisms are stepwise, with rate-determining formation of a zwitterionic tetrahedral intermediate (T±). A dual parametric equation with the pKa of the nucleophiles and non-leaving groups show βN = 0.26 and βnlg = −0.16, also in accordance with the proposed mechanism. On the other hand, the reactivity of these thiocarbonyl substrates and their carbonyl derivatives was studied using their hardness index and compared with their experimental parameters, confirming the proposed mechanisms. By comparison of the title reactions with similar aminolyses, the following conclusions arise: (i) The mechanism of the reactions under investigation is stepwise with rate-determining formation of T±. (ii) The reactivity of the substrates toward quinuclidines follows the order 4 > 3 > 2 > 1. (iii) Quinuclidines are more reactive than isobasic pyridines toward chlorothionoformates. (iv) Chlorothionoformates are less reactive than chloroformates towards quinuclidines in accordance with the HSAB principle. (v) The kN values for phenyl chloroformate and 4 can be correlated with the pKa of quinuclidines and also with the hardness values calculated by the HF/3-21G level of theory. Copyright © 2007 John Wiley & Sons, Ltd.
Ultrasonic Characterization of North Pacific Albacore (Thunnus alalunga)

Abstract This study examines the possibility of using a hand-held ultrasonic device to provideinformation about the composition of North Pacific albacore (Thunnus alalunga). The ultrasonic velocity and attenuation coefficient (1-6 MHz) of albacore samples of varying composition was measured over the temperature range 5 to 30EC. The lipid, protein, ash and moisture content of the same fish were measured using standard methods. Ultrasonic velocity versus temperature profiles were dependent on fish composition and could therefore be used to provide information about composition. Ultrasonic attenuation measurements were too variable to use as a means of providing information about fish composition. The availability of a hand-held ultrasonic device that is simple to use would be useful for grading albacore according to their composition.
Light‐induced migration of Ag in Xe films and generation of sites

Scattering losses and inhomogeneous broadening are reduced by an optimized cocondensation of laser evaporated Ag atoms with Xe gas allowing the determination of absolute quantum efficiencies in light‐induced processes. A jump probability per absorbed photon increasing from 10% to about unity for higher temperatures is observed for the migration of Ag atoms originating from electronic excitation. A model based on a concerted host–guest motion is proposed. A well defined metastable site with a strongly red shifted absorption band and a generation probability of 1.5% which decreases with temperature is attributed to an intermediate position in the migration process.
Identifying spatial structure in phytoplankton communities using multi‐wavelength fluorescence spectral data and principal component analysis

Rapid in situ measurements of some components of fluorescent spectra are now possible with submersible multi‐wavelength fluorometers, which implies that phytoplankton composition can be measured, at least implicitly, at a spatial resolution that allows many scales of patches to be resolved. We present a method for identifying the location of patches of distinct fluorescent groupings of phytoplankton by using principal component analysis (PCA) to process in situ spectral data. The processing method potentially allows retention of more information from the raw data than existing methods because it depends on fewer assumptions. Furthermore, it can be applied without the need for site‐specific calibration of the fluorometer. A series of idealized spectral data sets were used to explain the conceptual basis of the approach; the method was then applied to field spectral data sampled in Lake Victoria, Kenya. The results demonstrate that the main features of large sample sets of multi‐component spectral data can be summarized in a single graph that reveals the number of spectrally distinct groups of phytoplankton at the site, and allows information about the spatial structure of those different phytoplankton groups to be derived from subsequent analysis. In this way, fluorescent spectral data collected at high spatial resolution can be used to identify the locations of patches and facilitate targeted water sample collection from those locations to investigate the species diversity and distribution at a study site.
KINETICS OF THE THERMAL DECOMPOSITION OF ETHYL PROPIONATE

The pyrolysis of ethyl propionate has been studied in the temperature range 505–602 °C, yielding the Arrhenius equationBy the copyrolysis of this compound with ethyl-d5 acetate at 384 and 488 °C, and comparison of this temperature coefficient with that for the isotopic ethyl acetates, an activation energy difference between ethyl acetate and propionate of 20 ± 65 cal/mole was found, rather than 500 cal/mole as indicated in the individual studies. Since other evidence exists for an inductive effect in the decomposition due to the acid alkyl group, the lack of difference in activation energies is attributed to the change in effect being small and obscured by other effects.
Growth of Haematococcus lacustris: A Contribution to Kinetic Modelling

The results of studies with the microalga Haematococcus lacustris, grown under heterotrophic, autotrophic and mixotrophic conditions, were employed to fit kinetic parameters such as specific growth rate, linear growth rate and acetate consumption as a function of irradiance and acetate concentration. Growth was inhibited at the highest light intensities used, as was acetate uptake. The specific growth rate in mixotrophic conditions was obtained by the addition of autotrophic and heterotrophic components which were affected by a variable inhibition term depending on irradiance level and acetate concentration. © 1997 SCI.
Determination of paramagnetic lanthanide(III) concentrations from bulk magnetic susceptibility shifts in NMR spectra

The bulk magnetic susceptibility (BMS) shifts of 1H NMR resonance signals for inert reference compounds caused by the addition of paramagnetic lanthanide(III) compounds were exploited in order to determine lanthanide(III) concentrations in solution. The BMS shifts of an inert reference compound in the samples were measured by comparing the chemical shifts with those of an external reference. The concentration values obtained were in good agreement with results acquired from inductively coupled plasma analysis. Copyright © 2001 John Wiley & Sons, Ltd.
Kinetics and mechanism of hexachloroiridate(IV) oxidation of tellurium(IV) in aqueous solutions

The kinetics of oxidation of tellurium(IV) by [IrCl6]2− in aqueous perchlorate solutions at a constant ionic strength of 0.1 mol dm−3 have been investigated spectrophotometrically. The results showed a first-order dependence in [IrCl6]2−, fractional-first-order kinetics with respect to tellurium(IV) concentration and second-order overall kinetics. The increase in the [H+] was found to be accompanied by a decrease in the rate constants, i.e., the oxidation reaction was acid-inhibited. Kinetic evidence for the formation of a 1 : 1 intermediate binuclear complex between the two reactants has been obtained. The ionization constant of tellurium(IV) has been evaluated and found to be 1.69 × 10−3 dm3 mol−1 at 25 °C. The kinetic parameters have been calculated and a tentative reaction mechanism consistent with the kinetic data is suggested.
ADSORPTION, DESORPTION AND SOLUBILITY RELATIONSHIPS OF LEAD AND CADMIUM IN SOME ALKALINE SOILS

Summary In some alkaline soils of Punjab (India) the adsorption, desorption and solubility relationships of lead and cadmium were investigated and the results analysed by the Langmuir equation. Both the metals are retained in soils by adsorption on mineral interfaces and interaction with organic matter and calcium carbonate. At high concentrations, these probably precipitate as hydroxides. Sequential desorption of Pb and Cd with 1 MKCI and 0.05 MCu(CH3COO)2 provided a measure of their exchangeable and chelated form.
Fate of fertilizer nitrogen applied to grassland. II. Nitrogen-15 leaching results

SUMMARY Results are presented from a 3-year investigation into nitrate leaching from grassed monolith lysimeters treated with double (15NH415NO3) or single (15NH4NO3) labelled ammonium nitrate at three rates, 250, 500 and 900 kg N ha−1 a−1. Over the 3 years of the experiment, 0.14%, 3.1% and 18.1% of the applied fertilizer was recovered in the leachate at 250, 500 and 900kg N ha−1 respectively. This represented 9%, 39% and 75% of the overall nitrate leaching at the three application rates. A significant proportion of the fertilizer leached as nitrate at the three application rates was derived, via nitrification, from the fertilizer ammonium. Increasing fertilizer applications caused a rise in the leaching of both soil and fertilizer derived nitrogen, although whether the increase reflected a true priming effect was not clear.
A 140Nd/140Pr radionuclide generator based on physico-chemical transitions in 140Pr complexes after electron capture decay of 140Nd-DOTA

140Nd was produced by irradiations of CeO2 and Pr2O3 targets leading to natCe(3He,xn) 140Nd and 141Pr(p,2n) 140Nd nuclear reactions. The practical yield of 140Nd at EOB in the former reaction over the energy range of E3He = 33.5 → 0 MeV amounted to 3.5 MBq/μA h and in the latter reaction over the energy range of Ep = 18.6→16.2 MeV to 15.5 MBq/μA h. These values correspond to about 41% and 60% of the respective theoretical values. Successful separations of the radionuclide were performed by means of cation-exchange chromatography resulting in decontamination factors of ≥108 and ≥7×105 for the cerium and praseodymium target materials, respectively. With the no-carrier-added 140Nd obtained, an efficient 140Nd/140Pr radionuclide generator system was developed and evaluated. The principle of the radiochemical separation is based on physico-chemical transitions (hot-atom effects) of the daughter 140Pr following the electron decay process of 140Nd. The parent radionuclide 140Nd(III) is quantitatively adsorbed on a solid phase matrix in the form of 140Nd-DOTA-conjugated complexes. The daughter nuclide 140Pr is generated in an ionic species and is easily separated using low volumes of various aqueous eluents. The elution yield is at least 93%, if an optimized eluent, such as DTPA solution is applied. The system remains stable at least over three half-lives of 140Nd, with high radiolytic stability and low 140Nd breakthrough. This radionuclide generator system 140Nd (T1/2 = 3.37 d) provides the short-lived positron-emitting radiolanthanide 140Pr (T1/2 = 3.4 min) for molecular imaging using positron emission tomography (PET).
Thermally induced mixing in partially microphase segregated binary n-alkane crystals

In this study we have monitored the chain mixing and conformational disordering that occur as a partially microphase separated binary n-alkane mixture, 1:1 C 30 /C 36 , is transformed by stepwise heating into a randomly mixed solid solution. The partially demixed binary mixtures studied (1:1 C 30 H /C 36 H and C 30 H /C 36 D ) initially consist of small domains (percolation clusters) of average lateral dimensions of the order of 5-8 chains. The samples were prepared by rapid quenching of the melt to a room-temperature solid solution. This mixture, which is unstable, was then aged at room temperature to allow some degree of spontaneous demixing
Iron fertilization In relation to nodulation and nitrogen fixation in French bean (Phaseolus vulgaris L.)

Abstract Pot and field experiments were conducted to study the effects of three iron sources, viz., ferrous sulphate, Fe‐EDDHA and Fe‐EDTA on nodulation and nitrogen fixation in french bean (Phaseolus vulgaris L.). This plant, as a general, does neither harbour functional nodules nor enlodge the nitrogen‐fixing symbionts (rhizobia) when grown in and around Varanasi soils where natural availability of iron is 2–4 mg kg‐1 soil. Inorganic iron treatments were given to the soils without any exogenous inoculation with the Rhizobium germ plasm. Iron, in general, at a concentration of 5 to 10 mg kg‐1 soil stimulated the production of functional nodules and subsequently increased the dry weights of plants. Remarkably, the number of functional nodules and their leghaemoglobin content were more in the cases of plants treated with Fe‐EDDHA and Fe‐EDTA (@ 5 mg kg‐1 soil) than in the FeSO4 treated ones. Approachingly similar nodule initiations were recorded with the application of a double dose of FeSO4, i.e., @ 10 mg.
Heavy metal levels of pasture grasses in metropolitan area

Urban agriculture is becoming an important lucrative activity in Dar es Salaam City even though the city is subject to traffic and industrial pollution pressures. Poor planning has left only limited spaces, particularly road reserves, for cultivation and foraging animals. While there is increasing road traffic no study has been conducted determine levels of trace metals in pasture grasses. This study, therefore, reports on the levels of cadmium, manganese, lead and zinc of cynodon grasses in road vicinity in the city. Results show that the trace metal levels (ppm ± SDE) in Cynodon grass species were: Cd (0.24 ± 0.06 - 2.58 ± 0.15), Mn (41.5 ± 13.6 - 345.0 ± 124.3), Pb (1.15 ± 0.64 - 25.53 ± 1.29) and Zn (25.97 ± 3.69 - 95.36 ± 19.61). The mean levels of lead and zinc varied exponentially with distance off the road up to 15 m distance. Lead and zinc levels correlated with average daily traffic in the roads while cadmium and manganese did not. This suggests that lead and zinc in grasses owe their sources from the passing motor vehicles in agreement with other reported studies. It is recommended that pasture grasses in road vicinities must not be used for foraging dairy cattle and goats for public health reasons.
Removal of Trace Cd2+ Using Continuous Multistage Ion Foam Fractionation: Part II—The Effects of Operational Parameters

A multistage ion foam fractionation column with bubble-cap trays was employed to study the removal of cadmium ions from simulated wastewater having low Cd concentrations (10–30 mg/L), examining the effects of foam height, air flow rate, feed flow rate, and feed Cd concentration. Sodium dodecyl sulfate (SDS) was used to generate foam in this study. An increase in foam height, which reduces liquid hold-up in the generated foam, resulted in the enhancement of the enrichment ratios of both SDS and Cd while the removal and residual factor of Cd showed insignificant change. An increase in air flow rate increased the foam generation rate, foamate volumetric ratio, and the removal efficiency of Cd but decreased the enrichment ratios of both Cd and SDS. The separation factors of both Cd and SDS decreased with increasing feed flow rate, which is mainly attributable to both the effects of the enhancement of foamate volumetric ratio and the increases in both SDS and Cd input rates. An increase in feed Cd concentration was found to increase Cd effluent concentration and SDS removal but to decrease the enrichment ratios of both Cd and SDS because of the increasing liquid entrainment in the produced foam.
Determinação de compostos bioativos em amostras comerciais de café torrado

Coffee is a product consumed all around the world, Brazil being the biggest exporter. However, little is known about the difference in composition of the different brands in terms of bioactive substances. In the present study, ten of the most consumed brands of coffee in Rio de Janeiro were analyzed. Caffeine contents, trigonelline and total chlorogenic acid varied from 0.8 g/100g to 1.4 g/100g; 0.2 g/100g to 0.5 g/100g and from 3.5 g kg-1 to 15.9 g kg-1, respectively. The large heterogeneity observed in the amounts of the bioactive compounds can be attributed to different formulations of the various brands, as well as to different roasting conditions.
Water-in-Carbon Dioxide Microemulsions: An Environment for Hydrophiles Including Proteins

Carbon dioxide in the liquid and supercritical fluid states is useful as a replacement for toxic organic solvents. However, nonvolatile hydrophilic substances such as proteins, ions, and most catalysts are insoluble. This limitation was overcome by the formation of aqueous microemulsion droplets in a carbon dioxide-continuous phase with a nontoxic ammonium carboxylate perfluoropolyether surfactant. Several spectroscopic techniques consistently indicated that the properties of the droplets approach those of bulk water. The protein bovine serum albumin (BSA) with a molecular weight of 67,000 is soluble in this microemulsion and experiences an environment similar to that of native BSA in buffer.
Effect of an Orifice on Collection Efficiency and Wall Loss of a Slit Virtual Impactor

The effect of an orifice on the collection efficiency and wall loss of a slit virtual impactor was investigated both numerically and experimentally. The ratios of the collection nozzle width (Wc ), distance between acceleration nozzle and collection nozzle (S), length of acceleration nozzle (T), inlet width (D), and nozzle span (l) to the acceleration nozzle width (Wa ) were fixed at Wc /Wa = 1.4, S/Wa = 1.5, T/Wa = 1.1, D/Wa = 6, and l/Wa = 10, respectively. The minor-to-total flow ratio was set to 0.1 in laminar flow regime. The collection efficiency and wall loss of the slit virtual impactor were found to be characterized by the square root of the Stokes number. For the slit virtual impactor without an orifice, the square root of the Stokes number corresponding to the cut-off diameter was determined to be (Stk50)1/2 = 0.77 and the maximum wall loss at the collection nozzle reached 30% or 40%. When an orifice having the same width as the acceleration nozzle was placed upstream of the acceleration nozzle at a distance of 20Wa , the value of (Stk50)1/2 decreased to 0.68 and the wall loss at the collection nozzle decreased below 5%. Copyright 2014 American Association for Aerosol Research
Electrophoretic fabrication of highly robust, efficient, and benign heterojunction photoelectrocatalysts based on graphene-quantum-dot sensitized TiO2 nanotube arrays

We report the controllable electrophoretic fabrication of highly robust, efficient, and benign photoelectrocatalysts based on graphene-quantum-dot sensitized TiO2 nanotube arrays. Their catalytic activities under visible-light irradiation remain steady for continuous cycles (400 min) with a negligible decrease, whereas CdS and CdSe sensitized TiO2 nanotube arrays show a high cycling instability due to serious photooxidization.
Performance Optimization for Lithium–Oxygen Batteries

Lithium–oxygen coin cells without catalyst were assembled in argon atmosphere and tested in pure oxygen. Results showed that the first discharge performance of the batteries was strongly affected by the carbon loading, electrolyte amount and current density. At the carbon loading (0.4 mg/cm2), the electrolyte amount (160 μL/cell) and the current density (0.05 mA/cm2), a high capacity of 4586.5 mAh/g was obtained. The capacity decreased when the carbon loading or current density was increased. And the capacity would have a decrease when the amount of electrolyte was decreased. The highest capacity of 6010.2 mAh/g was obtained by optimizing the combination of carbon loading and electrolyte amount at current density of 0.01mA/cm2. However, the discharge capacity sharply decreased from the second cycle. It may be partly due to the fact that the pores of cathode surface were blocked by discharge products at the end of discharge.
Impacto da água residuária de suinocultura no solo e na produção de capim-elefante

ABSTRACT Intensive pig farming concentrates a great number of animals per area generating high volume ofwastewater, which requires correct disposal since it might cause environmental imbalance. Pig farmingwastewater (PFW) can be used as fertilizer due to its characteristics. This study aimed to evaluate the effectof applying pig farming wastewater on chemical properties of Dystric Nitosol and on elephant grass( Pennistum purpureum Schum) production. An experiment was carried out in field conditions consistedof five treatments plus control. T 0 = without PFW application (control), T 1 = 150 m 3 ha -1 , T 2 = 300 m 3 ha -1 ,T 3 = 450 m 3 ha -1 , T 4 = 600 m 3 ha -1 , T 5 = 750 m 3 ha -1 PFW applied during elephant grass crop cycle. P,K + , Mg +2 , Ca +2 concentrations were obtained in the soil before and after PFW application. Phosphorusconcentration in the soil increased as a function of PFW application rates increase. Al +3 concentrationdecreased. PFW application did not influence plant height and dry mass production of the grass.