Miracle-dz/UniFAR-FTUs huggingface dataset:
Synthesis and Molecular Structures of Nickel(II) and Cobalt(III) Complexes with 2‐(Arylimino)‐3‐(hydroxyimino)butane

We report new series of NiII and CoIII complexes with nitrogen-donor chelating ligands of the (E,E)-2-(arylimino)-3-(hydroxyimino)butane type (Ar−N∩N−OH). These ligands are characterized by a hydrophilic (OH group) and a hydrophobic region (aryl group). NiII derivatives were obtained either as trimers of formula [Ni3(Ar−N∩N−OH)3Br4(OH)][Br], with the hydrophobic groups oriented on the same side, or as bis(chelated) derivatives with cis geometry, depending on the steric hindrance of the aryl groups. CoIII complexes were obtained only as bis(chelated) derivatives, with the two ligands coplanar. The “iso-oriented” arrangement of ligands in bis(chelated) CoIII complexes is favored by weak interactions between the two ligands, namely O−H···O hydrogen bond and stacking interactions between the aryl groups. CoIII complexes might find application as catalysts for living or controlled radical polymerization of polar olefins, and preliminary results are reported. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003)
Phosphorus Retention in Streams and Wetlands: A Review

Wetlands and streams buffer the interactions among uplands and adjacent aquatic systems. Phosphorus (P) is often the key nutrient found to be limiting in both estuarine and freshwater ecosystems. As such, the ability of wetlands and streams to retain P is key to determining downstream water quality. This article reviews the processes and factors regulating P retention in streams and wetlands and evaluates selected methodologies used to estimate P retention in these systems. Phosphorus retention mechanisms reviewed include uptake and release by vegetation, periphyton and microorganisms; sorption and exchange reactions with soils and sediments; chemical precipitation in the water column; and sedimentation and entrainment. These mechanisms exemplify the combined biological, physical, and chemical nature of P retention in wetlands and streams. Methodologies used to estimate P retention include empirical input-output analysis and mass balances, and process kinetics applied at various scales, including micro- a.
Mechanical and structural characterization of atomic layer deposition-based ZnO films

Zinc oxide thin films were deposited by atomic layer deposition (ALD). The structural and mechanical properties of the thin films were investigated by x-ray diffraction, transmission electron microscopy, atomic force microscopy, and nanoindentation. Diethyl zinc was used as the chemical precursor for zinc and water vapor was used as the oxidation agent. The samples were deposited at 150 °C and at a pressure of 2.1 × 10−1 Torr in the ALD reactor. A growth rate of 2 Å per cycle was calculated in the ALD process window. The Nano Indenter XP was used in conjunction with the continuous stiffness method in depth control mode in order to measure and to analyze the mechanical properties of hardness and modulus of ALD ZnO thin film samples. For comparison, we benchmarked the mechanical properties of single crystal bulk ZnO samples against those of our ALD ZnO thin films.
Characterizations of Blend Gels of Carboxymethylated Polysaccharides and their Use for the Controlled Release of Herbicide

Polysaccharide-derived polymers are good carriers for encapsulating bioactive compounds for their controlled delivery. Aiming at extending the release of herbicide metolachlor in water, the novel gel beads were prepared by crosslinking the blend solutions of carboxymethyl cellulose (CM-cell) and carboxymethyl chitosan (CM-chit), and then used as the carrier in controlled release formulations (CRFs). SEM observation showed the formation of micro-aggregates in blend gel beads, and FT-IR analysis confirmed strong interactions between the two polymers. DSC analysis indicated stronger bonding of water by blend gels than that by pure CM-cell gel. The higher encapsulation efficiency and slower release of herbicide metolachlor were obtained by using the blend gel beads as the carrier of CRFs instead of the commercial emulsible oil formulation. The release of herbicide from the blend gels was dominated by a mechanism of Fickian diffusion, and related to their rapid and low swelling in water.
In situ synthesis of copper nanoparticles within ionic liquid-in-vegetable oil microemulsions and their direct use as high efficient nanolubricants

The current study highlighted a simple, efficient and environmentally friendly preparation method of a new type of nanolubricant. Herein, copper nanoparticles were successfully in situ synthesized within ionic liquid-in-vegetable oil microemulsions, and the as-prepared systems could be used as high-performance nanolubricants directly. Ascorbic acid and copper chloride were used as the raw materials for the synthesis of copper nanoparticles, whereas the castor oil, 1-butyl-3-methylimidazolium tetrafluoroborate and Triton X-100 were employed for the formulation of ionic liquid microemulsions. The copper-based ionic liquid-in-vegetable oil nanolubricants were characterized by dynamic light scattering, UV-visible spectra and a four-ball tribological tester, which confirmed the formation of copper nanoparticles and the improvement of the friction performance. The SEM micrographs and EDX chemical analysis were carried out to analyze the friction surface after sliding. The results showed that the designed nanolubricants presented an enhanced lubricating property compared to the neat ionic liquid microemulsion. In addition, the mechanism of the in situ synthesis of nanoparticles within nonaqueous ionic liquid microemulsions was discussed.
Elevated CO2 Improves Growth and Phosphorus Utilization Efficiency in Cereal Species Under Sub-Optimal Phosphorus Supply

Cultivars of Triticum aestivum, T. durum, and Secale cereale were grown at low (2 μM) and sufficient (500 μM) phosphorus (P) under ambient carbon dioxide (380 μmol mol−1; aCO2) and elevated CO2 (700 μmol mol−1, eCO2) to study responses of cereal species in terms of growth and P utilization efficiency (PUE) under P x CO2 interaction. Dry matter accumulation increased under eCO2 with sufficient P. Nevertheless, dry matter accumulated at eCO2 with low-P was similar to that obtained at aCO2 with sufficient P. Leaf area was 43% higher under eCO2 with sufficient P. Significant increase in lateral root density, length and surface area were noted at low-P under eCO2. Phosphorus use efficience (PUE) increased by 59% in response to eCO2 in low-P plants. Thus, eCO2 can partly compensate effect of low-P supply because of improved utilization efficiency. Among cereals, durum wheat was more suitable in terms of PUE under high CO2 and limiting P supply.
Surface Free Radical Activity of PM10 and Ultrafine Titanium Dioxide: A Unifying Factor in Their Toxicity?

Epidemiological evidence has been accumulating showing a strong relationship between particulate environmental air pollution (PM10) and end-points of respiratory ill health such as attacks of asthma, COPD, diminished lung function and cardio-vascular deaths (Pope et al., 1995). To date there has been no plausible biological hypothesis to explain this relationship at the very low airborne mass concentrations of particulate air pollution that are found (< 50 \ig ml"). We recently hypothesised (Seaton et al., 1995) that an ultrafine (< 100 nm diameter) component of PM10 is responsible for its adverse effects. This is based on the initial studies of Oberdorster and colleagues (Feirin et al., 1992) who demonstrated that titanium dioxide in the ultrafine form (20 nm diameter) was highly inflammogenic to the lungs of rats compared to fine (200 nm diameter) TiO2 particles at the same airborne mass concentration. We now hypothesise that the adverse effects of PM10 on the lung result from free radical activity at the surface of an ultrafine fraction. We further hypothesise that the interstitialisation that was seen with UFTiO2 (Ferin et al., 1992) could similarly occur with the ultrafine component of PM10. If the ultrafine material has free radical activity then the increased surface area that is presented to the epithelial surface by a relatively small mass of ultrafine particles could compromise epithelial integrity leading to interstitialisation. We demonstrate here that ultrafine TiO2 and PM10 both have hydroxyl radical activity and that UFTiO2 is capable of causing hydroxyl radical-mediated membrane damage to erythrocytes; fine TiO2 has much less of these properties. Additionally PM10 hydroxyl radical activity is either in the ultrafine fraction or is released in soluble form.
Adsorption and Flotation Characteristics of the Different Types of Frothers

This article investigates the adsorption of different frothers onto talc particles. The adsorption and flotation characteristisc of tallow amine acetate (TAA) + frothers (MIBC and pine oil) was studied for talc mineral. In this study, we analyzed some parameters affecting froth flotation performance and it was determined that adsorption capacity in particular, had an important role in froth flotation enrichment. The effect of pH and adsorption time on adsorption capacity was also studied. Analyses were carried out using ultraviolet spectrometry. The results showed that MIBC had the lowest frother adsorption capacity and it improved recovery during froth flotation of on the talc. It can be said that MIBC was adsorbed on the talc surface less and provided the best conditions to generate bubbles in flotation cell.
Compressibility of zinc sulfide nanoparticles

We describe a high-pressure x-ray diffraction (XRD) study of the compressibility of several samples of ZnS nanoparticles. The nanoparticles were synthesized with a range of sizes and surface chemical treatments in order to identify the factors that determine nanoparticle compressibility. Refinement of the XRD data revealed that all ZnS nanoparticles in the nominally cubic (sphalerite) phase exhibited a previously unobserved structural distortion under ambient conditions that exhibited, in addition, a dependence on pressure. Our results show that the compressibility of ZnS nanoparticles increases substantially as the particle size decreases, and we propose an interpretation based upon the available mechanisms of structural compliance in nanoscale vs bulk materials.
Magnetic ordering and dynamics in the XY pyrochlore antiferromagnet: a muon-spin relaxation study of Er2Ti2O7 and Er2Sn2O7

Spin dynamics in Er2Ti2O7 and Er2Sn2O7 have been probed by means of muon-spin relaxation (μ+SR) in the temperature range K. Both compounds are thought to constitute experimental realizations of the highly frustrated XY antiferromagnet on the pyrochlore lattice, for which theory predicts fluctuation-induced magnetic order. Our results for Er2Ti2O7 are consistent with a transition into an ordered state at K, in agreement with previous neutron measurements. Below this temperature, the muon relaxation rate λ(T) remains large ( MHz) and temperature independent, in contrast to the behaviour in conventional magnets. The thermal evolution of λ(T) for Er2Sn2O7 is somewhat similar to that of the Ti material. However, the depolarization curves remain exponential over the entire temperature range, suggesting a dense distribution of rapidly fluctuating magnetic moments, and, thus, are compatible with the absence of long-range order at least for T>0.02 K.
Direct measurement of the electric polarizability of isolated C60 molecules

We present the first direct measurement of the electric polarizability of isolated C60 molecules by molecular beam deflection technique. We have obtained a value of 76.5±8.0 A3 which is consistent with most of the recent calculations and slightly lower than the value of the polarizability of C60 measured in fullerite crystals.
Optochemical Sensor for Ammonia Based on a Lipophilized pH Indicator in a Hydrophobic Matrix

Abstract An optical sensor for the determination of ammonia in water based on ion pairing has been investigated. A pH-sensitive dye is immobilized as an ion pair in a silicone matrix. The colour of the dye changes from yellow to blue depending on the concentration of ammonia in the sample solution. This change is reversible. The concentration of ammonia can be determined by measuring the transmittance at a given wavelength. All measurements were performed with a dual-beam optical meter. The measurement range was from 5.9 × 10−7 to 1 × 10−3 M (0.01 to 17 mg/l) in 0.1 M phosphate buffer of pH 8. The detection limit was 10 μg/l. The response times at a flow rate of 2.5 ml/min were 4 min for t90 and 10 min for t100 at a change from 41.9 to 82.5 μM ammonia and 12 min for t90 and 48 min for t100 at a change from 160 to 0 μM ammonia. The operational lifetime of the ammonia sensor was limited to a period of a few days only. A continuous decrease in baseline signal and relative signal change was observed over the .
Benzolignanoid and Polyphenols from Origanum vulgare

A new dihydrobenzodioxane derivative, origalignanol (10), together with nine polyphenolic compounds, salvianolic acid A (1), salvianolic acid C (2), lithospermic acid (3), apigenin 7-O-β-D-glucuronide (4), apigenin 7-O-β-D-(6"-methyl)glucuronide (5), luteolin, (6), luteolin 7-O-β-D-glucopyranoside (7), luteolin 7-O-β-D-glucuronide (8), and luteolin 7-O-β-D-xylopyranoside (9), were isolated from the aqueous ethanolic extract ofthe aerial parts of Origanum vulgare for the first time. The structure of new compound 10 was determined on the basis of spectroscopic methods. Compound 5 is probably an artifact formed during the isolation. Compounds 1, 2 and 3 showed strong DPPH radical scavenging activity with an EC 5 0 of 7.2 ′ 0.4, 9.6 ′ 0.9, and 9.5 ′ 0.7 μM, respectively, and protected rat hepatocytes from CCl 4 -damage at 100 μM.
Vacuum Deposition by High-Energy Laser with Emphasis on Barium Titanate Films

A laser beam capable of energy outputs up to 500 Joule was directed through a glass window into a vacuum system onto fine grain powder of Cr, W, Ti, C, Sb2S3, ZnS, SrTiO3, and BaTiO3. A neodymium-doped glass laser of 1.06-μ wavelength was mostly used without Q spoiling. Sometimes the beam was focused. Films up to 2000 A were achieved on glass with one laser burst only, which corresponds to deposition rates of up to 106 A/sec. The substrate was positioned between the vapor source and laser so that the laser beam passed through it, and therefore, also served as a shield. Electron micrographs were taken. From electron transmission diffraction patterns it appeared as if BaTiO3 had not been decomposed. In order to evaluate electrical properties of the films, platinum-rhodium films were sputtered or “laser-deposited” onto glass slides to serve as base electrode. Then a barium titanate film was evaporated with a laser. On top of this, an array of thin aluminum dots were evaporated through a mask, so that it was .
Viscozulenic Acid: A Novel Sesquiterpene Acid from Polygonum viscosum

High-performance liquid chromatographic analysis of a methanol extract of Polygonum viscosum has yielded a novel sesquiterpene acid, 6-hydroxy-4-methoxycarbonyl-7-(1-methylethyl)-3,3a,6,7,8,8a-hexahydroazulene-1-carboxylic acid (named viscozulenic acid) [1], the structure of which was unambiguously elucidated by UV, HR-EIMS, and a series of 1D and 2D NMR experiments.
Nonlinear Optical Bioinspired Peptide Nanostructures

A nonlinear optical effect of a second harmonic generation (SHG) was first observed in quartz and then found in many inorganic materials that have an asymmetric crystalline structure. Second‐order nonlinear responses were also found in organic and biomaterials and are exploited for fundamental studies of helical and chiral biological molecules, such as proteins and amyloid fibrils. Another class of biomaterials is man‐made bioinspired nanostructures, which are composed of chemically synthesized biomolecules and are self‐assembled into supramolecular nanofibrils. Most of these materials have an asymmetric crystalline structure and possess ferroelectric and related phenomena. Here, the SHG effect is studied in bio‐organic peptide nanostructures of different morphologies and symmetries. These nanostructures are self‐assembled in different solvents from peptide precursors with a variable number of phenylalanine (F) amino acid units. A pronounced SHG response is detected in FFF‐nanobelts, FF‐nanotubes, and FFF‐nanospheres. SHG and Raman spectroscopy studies during phase transformation in FF‐nanotubes allow the definition of the intermolecular bonds responsible for SHG. Using two‐photon optical microscopy, orientational molecular ordering in aligned peptide supramolecular structures is found by adapting a generic model developed earlier for diverse biological protein fibrils. Efficient optical frequency conversion from NIR to green and blue light is demonstrated, as well as an effect of nonlinear optical waveguiding. These results suggest these bioinspired nanostructures as promising for a new generation of nonlinear optical nanomaterias, which can be integrated into nanophotonic devices.
Antifungal activity of polymer-based copper nanocomposite coatings

Eukaryotes, such as fungi, can be harmful pathogen agents, and the control of their bioactivity is critical as humans are eukaryote organisms, too. Here, copper∕polymer nanocomposites are proposed as antifungal spinnable coatings with controlled copper-releasing properties. The tests of the bioactivity show that fungal growth is inhibited on the nanocomposite-coated plates, and the antifungal activity can be modulated by controlling the Cu nanoparticle loading.
Model for partial discharges associated with treeing breakdown: III. PD extinction and re-growth of tree

When the electrode separation is long or the applied voltage is low, the tree cannot directly grow to the plane electrode, and extinction of partial discharge (PD) with the re-growth of new channels can be observed after a long time. Before PD extinction, the light emission of the PD changes from the whole tree structure to only the region near the needle tip, and the PD pattern also changes from wing-like to turtle-like. These phenomena are considered to be related to the increase of channel conductivity by PDs. Assuming the channel conductivity is higher in the region at tree tips or in the tree channels than near the needle tip, the simulation results coincide with the experimental results.
Separation of Carbon Dioxide and Sulfur Dioxide Using Room-Temperature Ionic Liquid [bmim][MeSO4]

A ternary equation of state (EOS) model for the CO2/SO2/1-butyl-3-methylimidazolium methyl sulfate ([bmim][MeSO4]) system has been developed in order to gain further our understanding of capturing and enhanced gaseous selectivity of industrial flue gases containing CO2 and SO2 using room-temperature ionic liquids. The present model is based on a generic Redlich−Kwong (RK) EOS. The empirical binary interaction parameters have been determined using our measured vapor−liquid-equilibrium (VLE) data for SO2/[bmim][MeSO4] and literature data for CO2/[bmim][MeSO4] and CO2/SO2. The validity of the present EOS has been checked by conducting ternary VLE experiments for the present system. With this EOS, an isothermal ternary phase diagram and solubility (VLE) behaviors have been calculated for various (T, P, and feed compositions) conditions. The addition of the [bmim][MeSO4] for small and equimolar CO2/SO2 mole ratios significantly increased the selectivity. For large CO2/SO2 mole ratios, the selectivity was high .
Enhanced Charge‐Carrier Injection and Collection Via Lamination of Doped Polymer Layers p‐Doped with a Solution‐Processible Molybdenum Complex

Poly(3‐hexylthiophene) (P3HT) is p‐doped by the new soluble dopant molybdenum tris[1‐(methoxycarbonyl)‐2‐(trifluoromethyl)‐ethane‐1,2‐dithiolene] and investigated via photoemission spectroscopy and transport measurements. Soft‐contact transfer lamination of thin layers of the doped P3HT on undoped polymer layers is used to create spatially‐confined doped regions, which serve as hole‐injection contacts on P3HT diodes. This strategy is then used to create efficient hole‐collecting contacts on solution‐processed inverted polymer solar cells.
The case for Auger recombination in In1−xGaxAsyP1−y

The possible Auger recombination mechanisms in direct‐gap semiconductors are investigated. These include band‐to‐band processes, phonon‐assisted processes, and Auger recombination via shallow traps. The band‐to‐band Auger rates are calculated including Fermi statistics, nonparabolic bands, and screening effects both for n‐type and p‐type semiconductors. The nonparabolicity is calculated using the Kane‐band model. The band‐to‐band Auger processes are characterized by a strong temperature dependence, the Auger rate decreasing rapidly with decreasing temperature. The phonon‐assisted and the trap processes do not exhibit such a strong temperature dependence. This is because the additional momentum conservation for the four‐particle states in band‐to‐band processes gives rise to a ’’threshold energy’’ for the process. For the same reason, the band‐to‐band Auger rate decreases rapidly with increasing band gap. In large‐band‐gap semiconductors the weakly temperature‐dependent phonon‐assisted processes are expect.
Graph colourings using structured colour sets

A natural generalisation of Æ-tuple colourings are (/? , ̂ -overlap colourings where p distinct colours are assigned to each vertex such that adjacent vertices share exactly q colours. The (p,#)-chromatic number is the smallest number of colours needed for a (/? ,^-overlap colouring. Inequalities of the (p,#)-chromatic number are obtained together with analogues of the Attainment and Periodicity theorems of Hilton, Rado & Scott [9]. Classes of subgraphs of the Kneser graphs are introduced, by identifying the underlying «-set with Zn, giving it a circular metric, and considering subgraphs induced by vertices whose k colours are pairwise at least a given distance, d apart. These Schrijver graphs are investigated and their fractional chromatic number is computed. A conjecture that generalises the Erdos-Ko-Rado Theorem [4] in the context of Schrijver graphs is given. The conjecture is proved to be true for the Schrijver graphs d S l with d = k = 2 and for d = where n < {k+\)d. The concept of displacement sequence is introduced together with the graphs they induce, the rotation subgraphs. Their independence and fractional chromatic numbers are found. In particular where the colours at each vertex are as far apart as possible and evenly distributed, the resulting rotation subgraph of G f , which has — 7— —vertices, is shown gcd(«, k) to have the same fractional chromatic number as G £. It is also shown to be star extremal and vertex critical with respect to both the fractional and circular chromatic numbers. Circular chromatic numbers of the Kneser graphs G £ for n = 2k+\ and for n = 2£+2 is computed. The relation between «-chromatic number for Z n -colouring (introduced by Vince [17]) and the chromatic number for Æ-tuple colouring (discussed by Stahl and by Hilton, Rado and Scott) is investigated. These two types of colouring are combined into a single colouring (Z„ £-colouring). Inequalities of its respective chromatic number are obtained and a generalisation of Theorem 1 of [17] is given. The circular distance graph is considered and shown to be isomorphic to a family of rotation subgraphs of G£ . Its chromatic number is derived. CONTENTS Chapter 1 Definitions & Introduction 1 Chapter 2 Overlap Colourings 8 2.1 General Properties of Overlap Colourings 8 2.2 The Attainment and Periodicity Theorems 12 Chapter 3 The Schrijver Graphs and the Theorem of Erdos-Ko-Rado 18 3.1 The Theorem of Erdds-Ko-Rado 18 3.2 Displacement Sequences 20 3.3 The Graphs 2 £ * 24 3.4 Linear Programming and Duality 26 3.5 Rotation Graphs 29