Miracle-dz/UniFAR-FTUs huggingface dataset:
Interaction of Inorganic Mercury(II) with Polyamines, Polycarboxylates, and Amino Acids

A study on chemical equilibria of different Hg2+−organic ligand systems is reported to establish the sequestration power of N/O donor groups versus metal. Ligand classes considered are: O-donors (succinate, 1,2,3,4-butanetetracarboxylate, 1,2,3,4,5,6-benzenehexacarboxylate, polymethacrylate, and polyacrylates); N-donors (ethylenediamine, diethylenetriamine, spermidine, triethylentetramine, tetraethylenpentamine, poly(allylamine), and poly(ethylenimine)); and amino acids (glycine, histidine, and aspartic acid). Equilibria were studied potentiometrically in NaNO3 at I = 0.1 mol·L−1 and t = 25 °C. For some systems, the dependence on ionic strength in the range (0 ≤ I ≤ 1) mol·L−1 (NaNO3) and the overall enthalpy changes, by calorimetric measurements, were also determined. The sequestering ability of ligands toward Hg2+ was evaluated, defining the amount of ligand necessary to sequester 50 % of the total metal cation concentration, pL50. The dependence on temperature and on ionic strength of pL50 was determin.
FTIR Study of Adsorption and Photoassisted Oxygen Isotopic Exchange of Carbon Monoxide, Carbon Dioxide, Carbonate, and Formate on TiO2

In-situ FTIR has been employed to investigate adsorption and photoassisted oxygen scrambling of CO, CO2, CO3, and HCOO on powdered TiO2 with 18O2. As clean TiO2 is exposed to CO at 35 °C, the IR frequencies of adsorbed CO shows that CO is bonded to Ti ions with an oxidation state +4 or less. The CO molecules that are bonded to two metal centers are more stable than those to only one center. In the case of CO2 adsorption, it produces adsorbed CO3 and CO2 with Ti−O−C−O bonding. Adsorbed CO does not exchange oxygen with 18O2, while adsorbed CO2, CO3, and HCOO do under UV irradiation. In the case of CO3 with bidentate configuration, only the oxygen bonded to the carbon with carbonyl character is involved in the exchange. Possible mechanisms for the oxygen scrambling of CO2, CO3, and HCOO are discussed.
Low-Noise YBa$_2$Cu$_3$O$_7$ NanoSQUIDs for Performing Magnetization-Reversal Measurements on Magnetic Nanoparticles

We fabricated YBa$_2$Cu$_3$O$_7$ (YBCO) direct current (dc) nano superconducting quantum interference devices (nanoSQUIDs) based on grain boundary Josephson junctions by focused ion beam patterning. Characterization of electric transport and noise properties at 4.2$\,$K in magnetically shielded environment yields a very small inductance $L$ of a few pH for an optimized device geometry. This in turn results in very low values of flux noise $<50\,{\rm n}\Phi_0/{\rm Hz}^{1/2}$ in the thermal white noise limit, which yields spin sensitivities of a few $\mu_{\rm B}/{\rm Hz}^{1/2}$ ($\Phi_0$ is the magnetic flux quantum and $\mu_{\rm B}$ is the Bohr magneton). We observe frequency-dependent excess noise up to 7$\,$MHz, which can only partially be eliminated by bias reversal readout. This indicates the presence of fluctuators of unknown origin, possibly related to defect-induced spins in the SrTiO$_3$ substrate. We demonstrate the potential of using YBCO nanoSQUIDs for the investigation of small spin systems, by placing a 39$\,$nm diameter Fe nanowire, encapsulated in a carbon nanotube, on top of a non-optimized YBCO nanoSQUID and by measuring the magnetization reversal of the Fe nanowire via the change of magnetic flux coupled to the nanoSQUID. The measured flux signals upon magnetization reversal of the Fe nanowire are in very good agreement with estimated values, and the determined switching fields indicate magnetization reversal of the nanowire via curling mode.
The crystal structure of perhamite

Abstract The crystal structure of perhamite, (Ca,Sr)3Al7.7Si3P4O23. 5(OH)14.1·8H2O, from the Emmons mine, Maine, USA, has been determined using single crystal X-ray data. The average structure has trigonal symmetry, P3̄m1, with cell parameters a = 7.021(1) Å and c = 20.218(1) Å. It was refined to R1 = 0.044 for 618 observed reflections. The structure comprises ordered blocks of crandallite-type structure, centred at z = 0, intergrown parallel to (001) with disordered aluminosilicate structure blocks centred at z = 1/2 to form a microporous structure containing large channels along [100]. These channels are bounded by 8-member rings of 6 tetrahedra (2 SiO4, 2 AlO4 and 2 PO4) and 2 AlO6 octahedra. Calcium atoms and water molecules are distributed in the [100] channels. A model was developed for the local ordering of silicon into the fractionally occupied sites in the (001) layer at z = 1/2 and this model was refined in space group P321 to R1 = 0.041 for 933 observed reflections. The dominant contributors to the local order are Si3O9 rings of corner-shared tetrahedra, together with Si2O7 pairs of tetrahedra. These units corner-link to (Al,Si)O4 tetrahedra above and below the plane at z = 1/2 to form 4-member rings, which in turn corner-share to PO4 tetrahedra in the crandallite blocks to give the 8-member rings. The analysis suggests that 5-coordinated Si may also be present in the (001) plane at z = 1/2.
Identification of Major Alkaloids in Rat Urine by HPLC/DAD/ESI-MS/MS Method Following Oral Administration of Cortex Phellodendri Decoction

A rapid, sensitive, and specific high-performance liquid chromatography (HPLC), diode-array detection, and mass-spectrometry techniques were developed for an identification of the constituents of Cortex Phellodendri and their metabolites in rat urine. The dose of 10 ml/kg of Cortex Phellodendri decoction was used for rats oral administration. 0-24-h Urine was purified using a C18 solid-phase extraction cartridge, and then analyzed by an on-line MS detector. A total of 13 characteristic HPLC peaks were detected in the urine samples. Nine of them, including five alkaloids and four of their metabolites, were tentatively elucidated as magnoflorine (1), the glucuronide conjugate of demethyleneberberine (2), menisperine (3), jatrorrhizine 3-O-glucuronide (4), berberubine 9-O-glucuronide (5), jatrorrhizine (6), the monomethyl and monohydroxy catabolite of berberubine (7), palmatine (8), and berberine (9). Identification and structural clucidation of the metabolites were performed by comparing their MS(n) spectra data with those reported.
High-field conduction and breakdown in polythene

Conduction currents in polythene have been measured at stresses of from 05 to 15 MV cm-1 and at several temperatures in the range 45-85°C. The current increased exponentially with stress and its temperature variation was consistent with an activation process. Differences in current densities and in activation energies were observed with aluminium and carbon electrodes. The possibility of thermal breakdown above 50°C, where the measured `intrinsic' electric strength varies with time until breakdown, is examined using Vermeer's method and the results show clearly that breakdown in polythene cannot be of a thermal nature. The most acceptable explanation of the time dependence of electric strength above 50°C is the existence of a plastic deformation caused by electrostatic attraction between the two charged surfaces of the polythene.
Application of Solid-Phase Microextraction for the Analysis of Aroma Compounds from Pineapple Fruit

An analytical method of solid-phase microextraction (SPME) was developed for pineapple aroma volatile compounds. Different sample preparation procedures involving SPME fibres, including the addition of sodium chloride, extraction time, and temperature, were evaluated to optimise the method. For the optimised method, 6.5 g of ground pineapple flesh was placed in a 20 mL headspace vial with 1 g of sodium chloride; a 65 μm polydimethylsiloxane/divinylbenzene fibre was used for extraction at 50°C for 40 min with continuous stirring. The method was validated by determining its repeatability and recovery. The relative standard deviations for the pineapple aroma compounds were 5.48-11.02%. The average method recovery was 99.13%. The results demonstrate that this SPME procedure is suitable as a simple, rapid, and solvent-free extraction technique for the analysis of pineapple aroma volatile compounds. Using this method, 15 volatile compounds were identified, and the amount was 1019.78 μg. kg−1 in pineapple cv. Shenwan, including seven esters, one terpene, two aldehydes, one ketone, two lactones, one alcohol, and one hydrocarbon. A tentative study to estimate the contribution of the identified compounds to the aroma of the pineapple variety based of their odour activity values indicated four compounds that were characteristic aroma compounds, including methyl hexanoate, δ-octalactone, decanal, and geranyl acetone.
Reduced chemistry for hydrogen and methanol premixed flames via RCCE

The method of Rate-Controlled Constrained Equilibrium (RCCE) provides a general and physically sound mathematical description of the dynamics of a chemical system, of which several species are assumed to be kinetically controlled and others equilibrated. In this paper we present an RCCE study of premixed hydrogen–air and methanol–air flames for a wide range of equivalence ratios, and burning velocity and detailed flame structure for both major and minor species are investigated. We also investigate the suitability of employing the species appearing in conventional reduced mechanisms as constraints, drawing an analogy between the constrained species in RCCE and the non-steady-state species in conventional reduced mechanisms. In particular, the RCCE mechanism is derived from a 63-species comprehensive mechanism of Lindstedt and co-workers and selection of constraints is carried out in accordance with the non-steady-state species employed in a systematically reduced mechanism for methanol derived from the same comprehensive mechanism. Most of the species are very well predicted both at stoichiometric and rich/lean limits.
Electrochemical nickel–phosphorus alloy formation

Abstract What is believed to be the first comprehensive review on electrochemical nickel-phosphorus alloy formation is presented. Nickel-phosphorus deposits are important surface finishes for industrial materials owing to their electrocatalytic activity for hydrogen evolution, special paramagnetic characteristics, excellent microhardness and corrosion resistance. Nickel- phosphorus is a relatively complex system and can form a number of stable compounds. Two mechanisms for the incorporation of phosphorus during electrodeposition of Ni-P have been proposed: a direct and an indirect mechanism. In the direct mechanism, the oxyacid in the bath, i.e. phosphorous acid (H3PO3), is reduced solely to the elemental state. In the indirect mechanism, phosphine (PH3) is an intermediate stage in the formation of the Ni-P alloy. Electrodeposition of nickel takes place in a fcc structure with co-deposition of phosphorus in octahedral interstitial sites. The pH of the plating solutions is an important consideration for the electrodeposition of phosphorus alloys. It is well known that above a critical phosphorus content, the Ni-P alloy becomes amorphous; amorphous alloys tend to be harder and have higher contact resistance than their crystalline counterparts. Amorphous alloys prepared by electrodeposition are generally brittle or of low ductility.
Solvent-free synthesis and stability of MgB12H12

MgB12H12 has been widely discussed as an intermediate in the hydrogen sorption cycles of Mg(BH4)2, but its properties such as stability and reactivity are still unknown. We achieved the synthesis of MgB12H12via the reaction between Mg(BH4)2 and B2H6 at 100 to 150 °C. When bulk Mg(BH4)2 was used as the starting material, a yield of 10.2 to 22.3 mol% was obtained, which was improved to 92.5 mol% by using Mg(BH4)2 nanoparticles. The as-synthesized MgB12H12 decomposed into boron between 400 and 600 °C, preceded by a possible polymerization process. The formation mechanism of MgB12H12 and its role in the decomposition process of Mg(BH4)2 are discussed.
Stormwater Quality Characteristics in Detention Basins

The use of stormwater detention basins for the dual purpose of flood control and mitigation of pollutant runoff loads has been promoted. However, only limited data and methods for analysis and prediction of pollutant removal in detention basins exist. This paper presents the results of a stormwater quality sampling program conducted to describe the particle size distribution and the time variable influent and effluent concentrations of chemical oxygen demand, total phosphorus, total kjeldahl nitrogen, and solids during various storm events. Concentrations in three separate particle size ranges for each of the four parameters was determined. The basin is shown to be generally effective in reducing solids, chemical oxygen demand, (COD), and total phosphorus. Total kjeldah nitrogen (TKN) concentrations and loadings were generally increased. The effectiveness of the detention basin in reducing pollutant loads appears to be related to two factors, namely, equalization and sedimentation. Dry weather water quality in the detention basin determines the importance of the former, whereas the particle size distribution for each pollutant determines the degree of sedimentation.
Toxicokinetics of chlorobenzenes in fish

In acute toxicity tests with guppies (Poecilia reticulata), lethal effects were found for 1,2,3-tri-, 1,2,3,4-tetra-, and pentachlorobenzene if the concentrations in the fish approached 2.0 to 2.5 μmol/g fish. The lethal concentrations were equal for the three test compounds and were independent of the exposure conditions. The lethal concentrations of chlorobenzenes in guppies were equal to those previously found for polychlorinated biphenyls in goldfish but approximately two times higher than those found for chlorinated phenols in goldfish. Combinations of the exposure times and exposure concentrations causing mortality can be described and readily predicted with a first-order bioconcentration model.
Safe levels of dustiness in cotton spinning mills

INTRODUCTION In the three years 1957--9, over 900 workers in the English cotton industry were awarded disability pensions for byssinosis1 • With some 14,000 at risk in the dusty processes, such a high incidence of disabling disease indicates that better dust control is needed. A survey was made in 5 mills with the main object of determining safe Ievels of dustiness2 • METHODS Clinical diagnosis The clinical history of respiratory symptoms was used to estimate the prevalence of byssinosis. The workers were graded by their histories as follows:Grade 0: no symptoms of ehest tightness or breathlessness on Mondays; Grade 1/2: occasional ehest tightness on Mondays, or mild symptoms such as irritation of the respiratory tract on Mondays; Grade 1: ehest tightness andjor breathlessness on Mondays only; Grade 2: ehest tightness andfor breathlessness on Mondays and other days. Detailed occupational histories were also recorded for each worker.
Plasma-surface interaction in heptane

The main processes related to discharges between pin and plate electrodes in hydrocarbon liquid (heptane) are modelled for micro-gap (from 10 to 100 μm) conditions. When a plasma channel hits the surface, a micro-crater is created. The different phenomena controlling the geometry (shape and dimension) of a single crater are described and included in a theoretical model developed for the specific case of pure aluminium. The influence of the most important parameters affecting the geometry of the crater is discussed. Among them, one finds the pressure exerted by the plasma on the liquid metal. It is found that the distribution of the pressure applied on the liquid pool changes significantly the way the plasma shapes the pool. It is assumed that at high charges, the pressure profile is tilted from the channel axis, leading to the formation of a central protrusion. On the other hand, we demonstrate that Thomson-Marangoni forces play an important role for crater diameters smaller than 5 μm. Then, the choice of.
EXPERIMENTAL STUDY OF THE EFFECTIVE SECONDARY EMISSION COEFFICIENT FOR RARE GASES AND COPPER ELECTRODES

Measurements are made for variations of the effective secondary emission coefficient γ with reduced field E/p. Plane-parallel copper electrodes (5 cm diameter) are sustained with a dc voltage (0<V<1 kV) and can be separated by a variable distance (2 mm<d<1 cm). Current–voltage characteristics, Paschen curves, and γ(E/p) variations are shown for various rare gases (neon, argon, krypton, and xenon). γ(E/p) values are deduced from Paschen curves and published α/p(E/p) variations by using the self-sustain condition. Comparisons are made with various experimental or calculated results taken from the literature.
The coupling of nitrification and denitrification in two estuarine sediments1,2

Nitrification and denitrification in estuarine sediments were measured by /sup 15/N isotopic tracer techniques at two stations in the Patuxent River estuary for April and August. A close coupling of the two processes was demonstrated directly from the evolution of labeled N/sub 2/ following /sup 15/NH/sub 4//sup +/ amendments during spring experiments. In contrast, this coupled nitrification-denitrification was decreased by two orders of magnitude in the summer, even though the capacity for denitrification remained similar to spring levels. This pattern of sharply seasonal nitrification was corroborated with measurements of bacterial relative abundance. Ambient rates of nitrification-denitrification were inferred from /sup 15/N experiments in these sediments.
A blue-LED-based device for selective photocoagulation of superficial abrasions: theoretical modeling and in vivo validation

The blue light (~400 nm) emitted by high power Light Emitting Diodes (LED) is selectively absorbed by the haemoglobin content of blood and then converted into heat. This is the basic concept in setting up a compact, low-cost, and easy-to-handle photohaemostasis device for the treatment of superficial skin abrasions. Its main application is in reducing bleeding from superficial capillary vessels during laser induced aesthetic treatments, such as skin resurfacing, thus reducing the treatment time and improving aesthetic results (reduction of scar formation). In this work we firstly present the preliminary modeling study: a Finite Element Model (FEM) of the LED induced photothermal process was set up, in order to estimate the optimal wavelength and treatment time, by studying the temperature dynamics in the tissue. Then, a compact, handheld illumination device has been designed: commercially available high power LEDs emitting in the blue region were mounted in a suitable and ergonomic case. The prototype was tested in the treatment of dorsal excoriations in rats. Thermal effects were monitored by an infrared thermocamera, experimentally evidencing the modest and confined heating effects and confirming the modeling predictions. Objective observations and histopathological analysis performed in a follow-up study showed no adverse reactions and no thermal damage in the treated areas and surrounding tissues. The device was then used in human patients, in order to stop bleeding during Erbium laser skin resurfacing procedure. By inducing LED-based photocoagulation, the overall treatment time was shortened and scar formation was reduced, thus enhancing esthetic effect of the laser procedure.
Development of an improved two-cycle process for recovering uranium from wet-process phosphoric acid

An improved two-cycle separation process for the recovery of uranium from wet-process phosphoric acid by extraction with bis(2-ethylhexyl)phosphoric acid (D2EHPA) plus dibutyl butylphosphonate (DBBP) in kerosene has been developed and demonstrated successfully in bench-scale, continuous mixer-settler tests. The sulfuric acid and water scrubbing steps for the recycled extraction in the second cycle solve the problems of the contamination and dilution of the phosphoric acid by the ammonium ion and water and also avoid the formation of undesirable phosphatic precipitates during the subsequent extraction of uranium by recycled organic extractant.
Compatibility of Ammonium Nitrate with Monomolecular Explosives. 2. Nitroarenes

Ammonium nitrate/fuel mixtures are widely used commercially; however, for military application it is often deemed necessary to enhance their performance by addition of conventional organic explosives. It is unreasonable to assume that such mixtures would retain the same thermal properties as the parent ammonium nitrate formulations. This paper presents a study of the thermal stability of such mixtures. Mixtures of ammonium nitrate and nitroaromatic compounds in various ratios have been decomposed isothermally in the temperature range 216-360 o C. The thermal decomposition kinetics of both ammonium nitrate and the nitroarenes have been followed by liquid chromatography. Markedly enhanced decomposition of both ammonium nitrate and the nitroarenes was observed
Ultimate Full Contact offensive efficiency analysed through styles and combat distances: a confluence of cognitive and ecological approaches

Background & Study Aim: Ultimate Full Contact is a hybrid combat sport where offensive efficiency takes on an important role during a fight. However, to the best of our knowledge, no study has investigated the impact of offensive efficiency based on combat style and distances. Thus, the study aimed is knowledge about the offensive efficiency related to distances, styles, skills and their interrelationships during combat. Materials & Methods: One hundred seventy fight DVDs were observed, integrating (n = 340) senior male athletes who participated in the WUFC World Championships. Technical-tactical attacks made and effective, between winners and losers, with different combat styles and distances were they used to analyse the difference between winners and losers and different combat styles, through the Kalina method for the combat dynamics analysis (only offensive efficiency index), Mann-Whitney U and Spearman’s bivariate correlation. Results: The results indicate that winners had significant advantage in all offensive skills regarding the different combat distances and styles. Generally, striking skills were more efficient than submission grappling. Higher correlations were shown between specific distances and specific styles. Conclusions: The winners attacked more and more effectively and showed greater efficiency, stability, versatility, adaptability and opportunity seizing. The biggest difference of winning or losing effect depends mainly on ground fighting (in horizontal posture), however it is supported by the efficiency of stand-up fighting (in vertical posture). It is not enough to react spontaneously according to the contextual opportunities without cognitively perceiving, interpreting and deciding on specific and certain actions at the right time, articulating styles with distances.
Molecular modeling of the core of Aβ amyloid fibrils

Amyloid fibrils, a key pathological feature of Alzheimer's disease (AD) and other amyloidosis implicated in neurodegeneration, have a characteristic cross‐β structure. Here we present a structural model for the core of amyloid fibrils formed by the Aβ peptide using computational approaches and experimental data. Aβ(15–36) was threaded against the parallel β‐helical proteins. Our multi‐layer model was constructed using the top scoring template 1lxa, a left‐handed parallel β‐helical protein. This six‐rung helical model has in‐register repeats of the Aβ(15–36) sequence. Each rung has three β‐strands separated by two turns. The model was tested using molecular dynamics simulations in explicit water, and is in good agreement with a number of experimental observations. In addition, a model based on right‐handed helical proteins is also described. The core structural model described here might serve as the building block of the Aβ(1–40) amyloid fibril as well as some other amyloid fibrils. Proteins 2004. © 2004 Wiley‐Liss, Inc.