Miracle-dz/UniFAR-FTUs huggingface dataset:
Studies of Niobium Electrocrystallization Phenomena in Molten Fluorides

The electrodeposition of niobium from NbCl{sub 5} or K{sub 2}NbF{sub 7}, dissolved in molten alkaline fluorides (LiF/NaF), in the 700--800 C temperature range has been studied by using cyclic voltammetry, chronopotentiometry, and chronoamperometry. A linear relationship between the Nb{sup IV} diffusion coefficient and the temperature was found in the cyclic voltammograms and chronopotentiograms. Scanning electron micrography shows that the shape of the nuclei is hemispherical. Chronoamperometric results show that the deposition process involves instantaneous nucleation with diffusion-controlled growth of the nuclei. The influence of temperature, overpotential, and substrate (copper, stainless steel, vitreous carbon) on the nuclear site densities is also considered.
Electrochemically derived gradients of the extracellular matrix protein fibronectin on gold

Surface composition gradients of extracellular matrix proteins show great promise as tools in understanding cellular adhesion and motility. The formation of a surface coverage gradient of the protein fibronectin (FN) is described. FN is covalently bound to a counterpropagating two-component gradient formed from thiols with carboxylic acid and hydroxyl terminal functional groups using carbodiimide coupling chemistry. Areas of the surface with initial −COOH termination react with amine groups on the FN, while protein adsorption is resisted on the −OH terminated regions. The −COOH/−OH gradient is generated by applying a linear potential profile to a thin Au gold film on which an 11-mercaptoundecanol (MUD) monolayer is present. A gradient in surface coverage of MUD results, which is then backfilled with 11-mercaptoundecanoic acid (MUA). The −COOH/−OH gradient is characterized by tagging with 200 nm diameter, fluorescently doped, amine-modified nanospheres using the same carbodiimide coupling chemistry and ima.
Peculiarities of reoriented bands formation in crystals

The peculiarities of the formation and the development of reorientated bands in crystals are considered. Reorientated bands are investigated experimentally in MgO single crystals under the compression testing. It is shown that the misorientation between the material in the band interior and the surrounding volume can reach some degrees. The data of electron microscopy investigations of dislocation structure of such bands are performed. The disclination model is proposed for the propogation of the reorientated bands. This model permits to explain the laws of the band development, for example, the formation of discrete areas with reoriented crystal lattice ahead the terminated band. [Russian Text Ignored].
Roles of Repulsive and Attractive Forces in Liquids: The Optimized Random Phase Approximation

The optimized random phase approximation (ORPA) is applied to the calculation of the thermodynamic properties and pair correlation function of simple liquids. General formulas are presented, together with results for the Lennard‐Jones fluid, which are compared with Monte Carlo and molecular dynamic results. Excellent agreement is obtained for the entire single phase fluid region of the phase diagram, except for the critical region and the very low temperature vapor. The theory converges especially rapidly at high densities or at high temperatures. The importance of separating the intermolecular potential in the proper way to obtain most rapid convergence of perturbation theories is discussed. It is concluded that the structure of simple liquids is determined mostly by the rapidly varying parts of the potential. Further, the ORPA provides an accurate theory for calculating the contributions from different forces to the structure and thermodynamics of liquids.
Solubility of CO2 in Water + Diethanolamine + 2-Amino-2-methyl-1-propanol

This work presents new experimental results for the CO2 solubility in aqueous blends of diethanolamine (DEA) + 2-amino-2-methyl-1-propanol (AMP) in the temperature range of (303 to 323) K and CO2 partial pressure of (1 to 100) kPa. The mass fractions of the aqueous amine blends were 1.5 % DEA + 28.5 % AMP, 3 % DEA + 27 % AMP, 4.5 % DEA + 25.5 % AMP, and 6 % DEA + 24 % AMP. A rigorous thermodynamic model is developed to correlate and predict the vapor−liquid equilibrium (VLE) of CO2 in aqueous blends of DEA and AMP. The modified Clegg−Pitzer equations have been used to develop a model for the quaternary system (CO2 + AMP + DEA + H2O) using the interaction parameters derived from the VLE data of the corresponding ternary systems (CO2 + AMP + H2O) and (CO2 + DEA + H2O). Simulated annealing has been used for parameter estimation and for the determination of equilibrium composition of various species present in the liquid phase. The model predictions are in good agreement with the experimental data of CO2 solu.
A facile procedure to fabricate nano calcium carbonate–polymer-based superhydrophobic surfaces

A facile procedure to fabricate superhydrophobic surfaces based on nano calcium carbonate–polymer composites has been described. The hydrophobicity of the resulting surfaces can be tuned by varying the weight ratio of nano calcium carbonate–polymer composites. The simple and robust strategy can facilitate the fabrication of superhydrophobic surfaces on general substrates.
The Limits of Fine and Coarse Particle Flotation

The flotation behaviour of quartz particles was studied over the particle size range from 0.5 µm to 1000 µm and for advancing water contact angles between 0° and 83°. Flotation was performed in a column and in a Rushton turbine cell. Particle contact angle threshold values, below which the particles could not be floated, were identified for the particle size range 0.5–1000 µm, under different hydrodynamic conditions. The flotation response of the particles, either in a column or in a mechanically agitated cell with a similar bubble size, was comparable. Turbulence plays a role, as does bubble-particle aggregate velocity and bubble size. The stability of the bubble-particle aggregate controls the maximum floatable particle size of coarse particles. For fine particles, the flotation limit is dictated by the energy required to rupture the intervening liquid film between the particle and bubble. Flotation of very fine and large particles is facilitated with small bubbles and high contact angles. These results greatly extend our earlier observations and theoretical predictions. On a etudie le comportement de flottation de particules de quartz pour des tailles de particules comprises entre 0,5 µm et 1000 µm et des angles de contact de l'eau de 0o et 83o. La flottation a ete realisee dans une colonne et dans une cellule munie d'une turbine Rushton. Les valeurs de seuils des angles de contact, en dessous desquels les particules ne pouvaient pas flotter, ont ete identifiees pour une gamme de particules de 0,5-1000 µm, dans differentes conditions hydrodynamiques. La reponse de flottation, dans une colonne ou dans une cellule agitee mecaniquement avec une taille de bulles similaire, est comparable. La turbulence exerce une influence, tout comme la vitesse des agregats de bulles et de particules et la taille des bulles. La flottation des particules tres fines et des particules larges est facilitee avec des bulles petites et des angles de contact eleves. Ces resultats elargissent de facon importante nos observations et predictions theoriques anterieures.
Intercalation Binding of 4‐Butylaminopyrimido[4′,5′:4,5]selenolo(2,3‐b)quinoline to DNA: Relationship with In Vitro Cytotoxicity

Abstract The interaction between double‐stranded (ds) DNA and the 4‐butylamino pyrimido[4′,5′:4,5]selenolo(2,3‐b)quinoline (BPSQ) has been studied with spectral luminescence methods. Binding constant values determined by absorption and fluorescence titration indicated a binding constant of 4.24 × 104 and 5.9 × 104 M−1, respectively. The interaction was markedly suppressed by increasing the salt concentration. BPSQ exhibited a strong specificity for the guanine–cytosine (GC) sequence in total DNA at an ionic strength of 0.01 (5.54 × 106 M−1). BPSQ increased the viscosity of sonicated rod‐like DNA fragments, producing a calculated increment in length of 2.4 Å per bound drug molecule. A circular dichroism experiment showed that BPSQ might interact with DNA according to two possible binding modes depending on its structure and concentration. The first mode concerned intercalation of BPSQ with its long axis perpendicular to the long axis of the DNA helix. The same drug was able to bind to external sites, second mode, once the intercalation sites were saturated at high concentration. The results from cytotoxicity assays indicate that BPSQ was found to be toxic to all cell lines tested with IC50 values ranging from 2.8 to ≥ 20 µM. It was concluded that the binding of BPSQ to DNA occurs by a mechanism of intercalation, which probably accounts for its reported antitumor activity.
Syntrophic Effects in a Subsurface Clostridial Consortium on Fe(III)-(Oxyhydr)oxide Reduction and Secondary Mineralization

In this study, we cultivated from subsurface sediments an anaerobic clostridial consortium that was composed of a fermentative Fe-reducer Clostridium species (designated as strain FGH) and a novel sulfate-reducing bacterium belonging to the clostridia family Vellionellaceae (designated as strain RU4). In pure culture, Clostridium sp. strain FGH mediated the reductive dissolution/transformation of iron oxides during growth on peptone. When Clostridium sp. FGH was grown with strain RU4 on peptone, the rates of iron oxide reduction were significantly higher. Iron reduction by the consortium was mediated by multiple mechanisms, including biotic reduction by Clostridium sp. FGH and biotic/abiotic reactions involving biogenic sulfide formed by strain RU4. The Clostridium sp. FGH produced hydrogen during fermentation, and the presence of hydrogen inhibited growth and iron reduction activity. The sulfate-reducing partner strain RU4 was stimulated by the presence of H2and generated reactive sulfide which promoted the chemical reduction of the iron oxides. Characterization of Fe(II) mineral products showed the formation of nanoparticulate magnetite during ferrihydrite reduction, and the precipitation of iron sulfides during goethite and hematite reduction. The results suggest an important pathway for iron reduction and secondary mineralization by fermentative sulfate-reducing microbial consortia through syntrophy-driven biotic/abiotic reactions with biogenic sulfide. Supplemental materials are available for this article. Go to the publisher's online edition of Geomicrobiology Journal to view the supplemental file.
Application of near Infrared Spectroscopy On-Combine in Corn Grain Breeding

Improving maize (Zea mays L.) grain yield and agronomic properties are major goals for corn breeders in northern Europe. In order to facilitate field grain yield determination we measured corn grain moisture content with near infrared (NIR) spectroscopy directly on a harvesting machine. NIR spectroscopy, in combination with harvesting, significantly improved quality and speed of yield determination within the very narrow harvest time window. Moisture calibrations were developed with 2117 samples from the 2001 to 2003 crop seasons using six diode array spectrometers mounted on combines. These models were derived from databases containing spectra from all instruments. Spectrometer-specific calibrations cannot be used to predict samples measured on other instruments of the same type. Standard error of cross-validation (SECV) and coefficient of determination (R2) were 0.56 and 0.99%, respectively. Moisture standard errors of prediction (SEPs) for the six instruments, using varying independent sample sets from the 2004 harvest, ranged between 0.59% and 0.99% with R2 values between 0.92 to 0.98. The six instruments produced the same dry matter predictions on a common sample set as indicated by high R2 and low biases among them, hence there was no need to apply specific standardisation algorithms. Moisture NIR spectroscopy determinations were significantly more precise than those obtained using the reference method. Analysis of variance revealed low least significant differences and high heritabilities. High precision and heritability demonstrate successful implementation of on-combine NIR spectroscopy for routine dry matter (yield) measurements.
Modeling transport in gas chromatography columns for the Micro-ChemLab

The gas chromatography (GC) column is a critical component in the microsystem for chemical detection ((mu) ChemLabTM) being developed at Sandia. The goal is to etch a `meter-long' GC column onto a 1-cm2 silicon chip while maintaining good chromatographic performance. Our design strategy is to use modeling and simulation approach. We have developed an analytical tool that models the transport and surface interaction process to achieve an optimized design of the GC column. This analytical tool has a flow module and a separation module. The flow module considers both the compressibility and slip flow effects that may significantly influence the gas transport in a long and narrow column. The separation module models analyte transport and physico-chemical interaction with the coated surface in the GC column. It predicts the column efficiency and performance. Results of our analysis will be presented in this paper.
Determination of exchangeable acidity, carbonate ions and change of buffer in triethanolamine‐buffered solutions percolated through soil samples containing carbonates

Abstract The content of dissolved carbonates and exchanged acidity in triethanolamine‐buffered BaCl2‐solutions which were percolated through soil samples containing carbonates is determined by two titration‐procedures to pH 4.0 and 10.25. because a single titration value gives no information of the amounts of both ionic species in solution. The amount of dissolved carbonates calculated on the bases of these titration‐procedures, however, is smaller than that determined by measuring the content of inorganic carbon in solution. The difference is attributed to the sorption of protonized triethanolamine‐buffer during percolation, which leads to an underestimation of CEC when measured by re‐exchanged Ba++, whereas the amount of exchangeable bases is overestimated due to dissolution of carbonates. The amount of exchanged acidity calculated from the data obtained is surprisingly high and is at least partly attributed to the existence of HCO3 ‐ ‐sorbed on the surface of (wet) soils.
Measurement of iron isotopes (54Fe, 56Fe, 57Fe, and 58Fe) in submicrogram quantities of iron

Iron isotopes offer an excellent opportunity for detailed tracing of natural processes because of the range of stable isotopes (54, 56, 57, 58) and the importance of iron redox transitions in biochemical and inorganic processes. In this paper, we describe a significantly improved mass spectrometric technique for iron isotopic analysis that utilizes ion pulse counting detection and is calibrated with an absolute iron isotope abundance standard. All four stable iron isotopes are quantified in a single analysis to approximately 0.1% precision and accuracy using a low-temperature (1200[degrees]C) silica gel/boric acid technique on an improved source filament assembly composed of platinum and ceramic. Filament loads of 100-1000 ng can be utilized through implementation of an ultraclean work environment, improved chemistry, and a source designed specifically to minimize isobaric interference in the mass 50-60 region. 30 refs., 5 figs., 4 tabs.
The Synthesis of Some New Mono and bis(Crown Ether)s and Their Sodium Complexes. Tautomerism in o‐Hydroxybenzo‐15‐crown‐5 Schiff Bases as Studied by UV‐VIS Spectrophotometry

Abstract New mono‐ and bis(crown ether) ligands have been synthesized by the condensation of the appropriate formylbenzo‐15‐crown‐5 [(2) and (4)] with ethanolamine and 1,2‐bis[(4‐aminophenoxy)methyl]benzene (6), respectively. The diamine (6), was prepared by the reaction of 1,2‐bis(bromomethyl)benzene and p‐nitrophenol in the presence of NaOH forming the dinitro compound (5) which is subsequently reduced to compound (6) using hydrazine hydrate and Pd/C. Homonuclear sodium complexes of the mono‐ and bis(crown ether) ligands have been prepared with sodium perchlorate. The UV‐VIS spectra of o‐hydroxycrown ether Schiff bases (7), (8), (7a), and (8a) have been studied in various solvents. The results indicate that bands observed at higher values than 400 nm to be the result of the keto‐amine form of the ligands and complexes. All of the crown ether ligands and their complexes have been characterized by elemental analyses, IR, UV, and NMR spectra.
Impact of pH on Anaerobic Substrate Uptake by PAOs and GAOs in an EBPR Activated Sludge Process Analyzed by MAR-FISH

The acetate uptake by polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) were compared under different pH conditions. These two microorganisms are known to play key roles in the enhanced biological phosphorus removal (EBPR) processes. In this study, micro-autoradiography (MAR) with acetate as the radio-labeled substrate and fluorescence in situ hybridization (FISH) with PAOmix probe and GB probe were applied. Activated sludge samples taken at a wastewater treatment plant were subjected to anaerobic batch incubation with radio-labeled acetate at different initial pH conditions. The relative amount of carbon uptake by each cell was estimated based on the silver granule area around the cell. The results showed that anaerobic acetate uptake by PAOmix-positive and GB-positive cells were affected by the initial pH. Both PAOs and GAOs were found to have a weak tendency to take up less acetate under higher initial pH conditions.
Molecular dynamics with multiple time scales: The selection of efficient reference system propagators

Several heuristic rules are developed to assist in the implementation of the reversible reference system propagator algorithm (rRESPA). This is done through the use of examples, illustrating the use of properly chosen rRESPA splits of various types, as well as the dangers associated with improperly chosen ones. It is concluded that a particle‐based rRESPA split should be used only when there is a great disparity in particle masses, and that a force‐based split should be used only when there is no persisting opposition between forces in the system which are integrated with different time steps.
Stretchable wavy metal interconnects

Buckled, wavy metal stripes are promising candidates for interconnects in flexible and stretchable electronics. To obtain wavy metal films, 5 nm of Cr (for adhesion) and 20 nm of Au were evaporated on polydimethyl siloxane (PDMS) prestretched by 25%. The metals buckle to a wave upon release of the PDMS from the prestretched position. The electrical resistance of the Au was measured as a function of applied tensile strain. Results show the metal remains electrically conductive up to 100% strain and maintains electrical continuity under repeated mechanical deformation. Presented are the sample fabrication, surface topography, and results of experiments conducted on these stretchable wavy metals.
Heterogeneous Interactions of OH and HO2 Radicals with Surfaces Characteristic of Atmospheric Particulate Matter

The heterogeneous interactions of OH and HO2 radicals with a number of surfaces characteristic of atmospheric particulate matter have been studied by using a low-temperature flow tube coupled to a resonance fluorescence detector. In particular, the mass accommodation coefficients (α) of both OH and HO2 on supercooled sulfuric acid solutions have been measured: for OH, α > 0.2 for 45−96 wt % solutions from 220 to 295 K, and for HO2, α > 0.2 on 55 wt % solutions doped with 0.1 M CuSO4 at 223 K. Radical uptake coefficients (γ) were also measured on a variety of solid surfaces prevalent in the atmosphere: water ice, NH4HSO4 and (NH4)2SO4. On water ice, although it was found that the uptake coefficients of both OH and HO2 were relatively small on conditioned surfaces (γOH = 0.03 ± 0.02 from 205 to 230 K, γHO2 = 0.025 ± 0.005 at 223 K), it was observed that the OH uptake coefficient could be significantly increased by either adsorbing HNO3 to the surface or melting the ice surface by exposure to relatively hi.
Reaction field effects on nitrogen shielding

Solvation effects on nuclear magnetic shielding at nitrogen in the CH3CN, CH3NO2, CH3NCS, and CH3ONO2 molecules are studied using electronic structure calculations. Reaction field theory together with a dielectric continuum is invoked to describe solute-solvent electrostatic interactions, using a solute electronic isodensity contour to define the cavity surface. With the common approach that treats only surface polarization effects, it is found that the nitrogen shielding is very sensitive to the cavity size and usually provides results in reasonable agreement with experiment only for rather large cavity sizes corresponding to contour values of ∼0.000 25–0.0005 a.u. With a more complete treatment that also includes volume polarization effects arising from penetration of the solute charge density outside the cavity, the nitrogen shielding becomes much less sensitive to the cavity size and reasonable agreement with experiment can be obtained with contour values ∼0.001–0.003 a.u. , which is more consistent wi.
Palladium–magnesium nitrate as a chemical modifier for the determination of lead in mussel slurries by electrothermal atomic absorption spectrometry

A method for the determination of lead in mussel slurries by atomic absorption spectrometry with electrothermal atomization using Pd–Mg(NO3)2 as a chemical modifier is proposed. The drying, ashing and atomization temperatures were optimized. Calibration and standard additions graphs, sensitivity, precision, accuracy and the effects of different slurry stabilization agents were also studied. The method was applied to the determination of lead in mussel samples from the Galician coast and the results obtained were compared with those achieved by means of a wet digestion procedure.
γ-Alkylsulfide phosphonates through the thia-Michael strategy

The formation of γ-alkylsulfide phosphonates is described from allylphosphonates under mild conditions using thiols through the thia-Michael strategy. A series of new phosphonates, bisphosphonates were cleanly prepared in high yields. The methodology developed allowed further preparing γ-alkylsulfide phosphonates bearing valuable esters groups in β and δ positions with respect to the phosphonate moiety. GRAPHICAL ABSTRACT
Development and validation of a sandwich ELISA for quantification of peanut agglutinin (PNA) in foods

Abstract In this study, two anti-peanut agglutinin (PNA) polyclonal antibodies were successfully prepared. Using mouse anti-PNA polyclonal antibody as the capture antibody and rabbit anti-PNA polyclonal antibody as the detection antibody, a novel sandwich enzyme-linked immunosorbent assay (ELISA) was developed to quantify PNA. The detection limit of the ELISA method was low (0.49 ng/mL), and the linear dynamic range was between 0.78 and 100 ng/mL. The recovery ranged from 93.86% to 139.3%, whereas the intra- and inter-assay coefficients of variation were less than 10.25% and 12.06%, respectively. Sample analysis verified this method as a reliable tool for the detection of PNA in processed foods.