Miracle-dz/UniFAR-FTUs huggingface dataset:
Recent Topics on Functionalization and Recognition Ability of Calixarenes: The ‘Third Host Molecule’

This review article covers recent topics of a calixarene family concerning their stereochemistry, complexation with metal ions and organic guests, and other topics. As stereochemistry of calixarenes, the restriction of flipping motions of the composed benzene units of calix[4]-, [5]-, [6]arenes is summarized. In Recognition of Calixarenes, the selective recognition of alkali metal cations utilizing calixcrowns is a main subject in metal cation recognition. Concerning with recognition of metal cations and organic molecules, the ‘reading-out’ systems of recognition phenomena are summarized. The complexation of calix[8]arene with fullerene, which was discovered as serendipity and will be very useful as a new fullerene purification method is also reported.
Relation between Crystallite Size and Dispersion on Supported Metal Catalysts

Universal mathematical relations between the mean relative size of metallic crystallites (drel(VS)) and their dispersion (FE) in supported metal catalysts have been developed. The relations are: drel(VS) = 5.01/FE for FE 0.2 the commonly used definition of dVS should be modified. The developed relations apply well to various thermodynamically probable crystallite shapes including fcc cubooctahedra of varying geometry, icosahedra, surface-reconstructed cubooctahedra, bcc rhombic dodecahedra, and hcp truncated bipyramids. The new relations are more precise than the commonly used equation dVS = a/FE, where a is a constant specific to a given metal.
Synthesis, characterization, and NO release study of the cis- and trans-[Ru(Bpy)2(SO3)(NO)]+ complexes

Aiming at the development of novel NO donors, the synthesis and reactivity of the trans-[Ru(bpy)2(SO3)(NO)](PF6) and cis-[Ru(bpy)2(L)(NO)](PF6)n complexes (L = imidazole, isonicotinamide, or sulfite ions) were investigated. The complexes were characterized and the NO release capabilities were evaluated. The rate constant for NO dissociation for the cis-[Ru(bpy)2(SO3)(NO)]+ complex is k = 2.0·10–3 s–1. The cis and trans- [Ru(bpy)2(SO3)(NO)]+ complexes showed promising physical-chemical properties towards nitric oxide generation, and great stability towards hydroxide attack in the 2.0–9.0 pH range. The reduction potential of the {RuNO}6/7 process of the cis and trans-[Ru(bpy)2(SO3)NO]+ complexes (E1/2 =–0.14 and –0.34 V vs. Ag/AgCl) is appropriated for reduction in vivo by biological reducing agents, with consequent NO release. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Synthesis and Electrical Properties of Tungsten-Doped Vanadium Dioxide Nanopowders by Thermolysis

Tungsten-doped vanadium dioxide (VO2) nanopowders were synthesized by thermolysis of (NH4)5[(VO)6(CO3)4(OH)9]·10H2O at low temperature with, to the best of our knowledge, active white powdery tungstic acid (WPTA) used as a substitutional dopant for the first time. The change in electrical resistance due to the semiconductor−metal transition was measured from −5 to 150 °C by the four-probe method. Differential scanning calorimetry and the resistance−temperature curve of the nanopowders indicated that the phase transition temperature of VO2 powders was 67.15 °C, but for W-doped VO2, the temperature was reduced to 26.46 °C. The results indicated that WPTA was found to be exceptionally effective as a dopant for reducing the transition temperature.
Charge Transfer Complex of TTF‐Carbon Nanotubes

Abstract The charge transfer complex of multi‐walled carbon nanotubes (MWNTs) and tetrathiafulvalene (TTF) was prepared and characterized by x‐ray photoelectron spectroscopy (XPS), and electron spin resonance (ESR) spectrometer. The results demonstrated that MWNTs could act as electron acceptors in the formation of charge transfer complex.
Spectroscopic Analysis of Pigments and Binding Media of Polychromes by the Combination of Optical Laser-Based and Vibrational Techniques

Four spectroscopic techniques, Fourier transform Raman (FTR), Fourier transform infrared (FT-IR), laser-induced breakdown spectroscopy (LIBS), and laser-induced fluorescence (LIF), are employed to characterize the pigment and binding media composition of polychromes. Raman spectra allow the assignment of the main pigments; these are α-HgS (vermilion), 2PbCO3·Pb(OH)2 (lead white), As2S3 (orpiment), Pb3O4 (lead red), and amorphous Carbon. The IR spectra can readily identify the pigment 2PbCO3·Pb(OH)2, the binder CaSO4·2H2O (gypsum) and, in combination with the Raman results, the presence of organic constituents of the binding media such as aliphatic esters, free acids, carbohydrates, and amides. The elemental analysis provided by LIBS corresponds to the pigments identified by the previous techniques and shows in addition the presence of some Hg, Fe, and Pb containing components. The presence of a Hg derivative in some of the sampled areas is supported by the LIF analysis; the fluorescence spectrum is mainly assigned to the binding media with the spectral intensity and shape modified to some extent by the contribution of pigments. In some of the samples studied, a peak assigned to α-HgS is observed. The effect of low intensity KrF laser irradiation of the samples is examined; the combined observations point toward a laser cleaning effect except in the areas that contain the pigment 2PbCO3·Pb(OH)2.
Rank annihilation factor analysis for multicomponent kinetic‐spectrophotometric determination using difference spectra

In this work rank annihilation factor analysis (RAFA) is used to analyze difference spectra of kinetic‐spectrophotometric data. Annihilation of the contribution of one chemical component from the original data matrix is a general method in RAFA. However, sometimes RAFA is not suitable for studying rank deficient data such as kinetic‐spectrophotometric measurements. On the other hand, in order to apply RAFA for the determination of an analyte in an unknown sample, a standard two‐way matrix of the analyte with rank one should generally be available. This is not usually attainable for kinetic‐spectrophotometric monitoring of complexation reactions. Processes monitored by difference spectroscopy always have the spectrum of the initial stage subtracted from each spectrum in the data matrix. In this work we show that, for kinetic‐spectrophotometric data of complexation reactions, the spectrum of ligand (reactant) itself can be used as initial spectrum for subtraction. The obtained difference matrix of sample and that of analyte of interest will be full‐rank and rank 1, respectively. Therefore the system can be analyzed by RAFA. The proposed method was investigated with simulated data at the first stage. The method was then applied in the analysis of experimental kinetic‐spectrophotometric data of a complexation reactions of Co(II) and Ni(II) with chromogenic reagent 1‐(2‐pyridylazo) 2‐naphthol in order to do multi‐component determination of these ions in various real samples. Copyright © 2009 John Wiley & Sons, Ltd.
Removal of 2-Chlorophenol from Aqueous Solution by Mg/Al Layered Double Hydroxide (LDH) and Modified LDH

Sorption is a common treatment for removing pollutants from natural environments. Layered double hydroxides (LDHs), which consist of brucite-like positive layers and sodium dodecyl sulfate intercalated with LDH (SDS−LDH), are considered to be potential organic pollutant sorbents. The objectives of this study were (1) to evaluate the impact of removing 2-chlorophenol (2-CP) using Mg3-Al-(NO3) LDH and SDS−LDH and (2) to investigate the removal efficiencies of these two compounds. All fitted sorption data reveal that the second-order model and the Langmuir model best describe the sorption kinetics and isotherms, respectively. By visual MinteqA2 (2000) calculation, the dissociation pKa of 2-CP is 8.56. The experimental results indicate that a high concentration of 2-CP is sorbed by the hydrophilic-hydrophilic physical interaction of LDH when the pH is >8.56; however, the hydrophobic−hydrophobic partition interaction of SDS−LDH is more vital when the pH is <8.56. LDH and SDS−LDH can be removed not only in the .
Fibrous-structured magnetic and mesoporous Fe3O4/silica microspheres: synthesis and intracellular doxorubicin delivery

A novel, fibrous-structured bifunctional (magnetic and mesoporous) Fe3O4/silica microsphere was successfully synthesized through a simple and economical self-assembled process in which hydrophobic 9 nm-Fe3O4nanocrystals were directly used without modifications. The obtained material is performed as a drug delivery carrier to investigate the in vitro and intracellular delivery properties of doxorubicin hydrochloride (DOX). X-Ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N2adsorption/desorption, Fourier transform infrared spectroscopy (FT-IR), and superconducting quantum interference device (SQUID) were employed to characterize the composite. The results reveal that the novel composite exhibits typical mesoporous structure, narrow size distribution, good monodispersity, and superparamagnetic features. Notably, confocal laser scanning microscopy (CLSM) images indicate that the DOX-loaded sample could deliver DOX into the nuclei of HeLa cells to kill cells. Also, MTT assay confirms that the DOX-loaded sample leads to pronounced and efficient cytotoxic effects to L929 fibroblast cells, even similar to that of free DOX at high concentrations, whereas the pure material is non-toxic. Therefore, the novel material is expected to have potential application for targeted cancer therapy.
Enhancing selectivity in photocatalytic formation of p-anisaldehyde in aqueous suspension under solar light irradiation via TiO2 N-doping

The photocatalytic partial oxidation of 4-methoxybenzyl alcohol to the corresponding aldehyde (p-anisaldehyde) was performed under simulated solar irradiation by using home prepared N-doped TiO2 catalysts. The photocatalysts were prepared by a sol–gel method, using TiCl4 as TiO2 precursor and NH4Cl, urea or NH4OH as N-doping sources. A commercial TiO2 (Degussa P25) was also used for comparison aims. The prepared catalysts were characterized by BET specific surface area, XRD, ESEM and UV-vis spectroscopy. The reactivity results show that (i) the doped catalysts are predominantly amorphous, and they show selectivity values far higher than those of the corresponding undoped ones and of well crystallized catalysts – even if the last ones show a higher activity – and (ii) exploitation of solar light significantly increases the reaction selectivity. In addition, different light sources were also used in order to investigate the effect of radiation wavelength ranges on the reactivity and selectivity to aldehyde.
Macrophyte Species Changes in the Everglades: Examination along a Eutrophication Gradient

Macrophyte species distribution in the marsh and slough areas of the northern Everglades were examined along a surface water and soil P gradient to characterize the effects of nutrient enrichment on the macrophyte community changes in the Everglades ecosystem. Macrophyte species distribution and frequency examined at 51 sites located in the Water Conservation Area (WCA-2A) revealed distinct trends in species changes with P enrichment. Marshes in the unenriched and enriched areas were dominated by Cladium jamaicense and Typha domingensis, respectively. Open water areas were characterized by Eleocharis sp. , Utricularia sp. , Chara zeylanica, and Nymphaea odorata in the unenriched areas and by floating plants and Polygonum sp. in the enriched areas. We compared the macrophyte species distribution with the soil P contour map of WCA-2A and derived six major categories of P enrichment (labeled 0-5) that may be used to adequately describe macrophyte species distribution in the WCA-2A. Soil and surface water P values that correspond to the different P-enrichment categories and the number of macrophyte species in each category have been estimated. Examination of the relative abundance of the macrophyte species in the six P-enrichment categories showed a decline in characteristic slough macrophyte species with P enrichment. Increase in P status of the system was also accompanied by the advent and gradual establishment of macrophytes such as Mikania scan dens, Sarcostemma clausum, Polygonum sp. , Acrostichum danaeifolium, and a variety of floating plants. Characteristic slough macrophyte species such as Utricularia purpurea, Eleocharis elongata, and Eleocharis cellulosa serve as indicators of the unenriched P conditions.
What Currently Limits Charge Carrier Mobility in Crystals of Molecular Semiconductors

Charge carrier mobility is a central property that characterizes the performances of organic semiconductors and is mostly measured in field-effect transistors. High mobility values are sought by many research teams. This article, that provides an overview of best performing molecular semiconductors is constructed on the question: What currently limits charge carrier mobility in crystals of molecular semiconductors? With this in mind, we confront, in a critical way, the current theoretical understanding to the most salient experimental results with the hope to reach a deeper understanding based on first principles and order of magnitudes of the main physical parameters.
Random‐field ising systems: A survey of current theoretical views

Abstract Ising or Ising-like models in random fields are good representations of a large number of impure materials. The main attempts of theoretical treatments of these models--as far as they are relevant from an experimental point of view--are reviewed. A domain argument invented by Imry and Ma shows that the long-range order is not destroyed by weak random-fields in more than D = 2 dimensions. This result is supported by considerations of the roughening of an isolated domain wall in such systems: domain walls turn out to be well defined objects for D > 2, but arbitrarily convoluted for D < 2. Different approaches for calculating the roughness exponent ζ yield ζ= (5 - D)/3 in random-field systems. The application of ζ in incommensurate-commensurate critical behaviour is discussed. Non-classical critical behaviour occurs in random-field systems below D = 6 dimensions which is determined in general by three independent exponents. The new exponent yJ = θ= D/2 - σ corresponds to random-field renormalization.
Storage of Methane in Resin Carbon Beads and Discs

Porous resin beads can be produced by the emulsion polycondensation of lignosulphonates with crosslinking agents. These resins can be converted into active carbon beads or pressed into discs that can be converted into active carbon monoliths. The stored methane volumetric capacity of the active carbon discs exceeded 150 v/v while the delivered capacity approached this value. The delivered capacity could be increased if steps were taken to release the large amount of methane retained in micropores after decompression. The volumetric methane capacities of the carbon beads were lower than those for the discs due to the presence of interparticulate voids.
Phase separation of co-evaporated ZnPc:C60 blend film for highly efficient organic photovoltaics

We demonstrate phase separation of co-evaporated zinc phthalocyanine (ZnPc) and fullerene (C60) for efficient organic photovoltaic cells. With introducing a poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) film and a crystalline copper iodide film on indium tin oxide, 20-nm-thick ZnPc film adopts a lying-down crystalline geometry with grain sizes of about 50 nm. This surface distributed with strong interaction areas and weak interaction areas enables the selective growth of ZnPc and C60 molecules during following co-evaporation, which not only results in a phase separation but also improve the crystalline growth of C60. This blend film greatly enhances the efficiencies in photocurrent generation and carrier transport, resulting in a high power conversion efficiency of 4.56% under 1 sun.
FDTD Method for Light Interaction with Liquid Crystals

Finite-difference time domain method(FDTD)for optical propagation through liquid crystal structures have been compared with analytical results. Conclusions about the accuracy of the FDTD method and possible sources of errors have been made. An algorithm that provides feedback between the change of the director distribution and the optical field has been proposed. We have demonstrated the effectiveness of our technique by considering the example of light propagation through a nematic liquid crystal cell with an applied electric field and photosensitive polymer on one of the substrates. The results give insight into the demands of the FDTD method for liquid crystal structures and demonstrate how it might be extended for more complex liquid crystal devices.
Measurement of thermal diffusion in thin films using a modulated laser technique: Application to chemical‐vapor‐deposited diamond films

A method to determine the thermal diffusivity in thin films, based on the measurement and analysis of thermal waves induced by a modulated infrared laser, is demonstrated. A nearly exact mathematical description, independent of the film geometry and including surface heat losses, is presented. It is shown that the in‐plane thermal diffusivity and the heat loss through the surface can be determined independently by analysis of both the phase and the amplitude of the thermal waves. The validity of the method has been verified using high‐purity copper sheets of varying thickness, for different modulation frequencies. Several polycrystalline, chemical‐vapor‐deposited (CVD) diamond films have been investigated. The measurements were performed both on free‐standing films and on two‐layer systems of CVD diamond and copper. Thermal diffusivities for polycrystalline diamond up to 6.2 cm2 s−1 were recorded.
An In Vitro Procedure for Estimation of Lead Relative Bioavailability: With Validation

ABSTRACT The relative bioaccessibility leaching procedure (RBALP) is a simple, reproducible, and rapid in vitro procedure for estimating the in vivo (juvenile swine) relative bioavailability (RBA) of lead in solid media. Control of pH, temperature, and agitation are the most critical parameters of this in vitro procedure. The performance of the method was evaluated by triplicate analyses of each of 19 different test substances by the author and three independent laboratories, and comparison of the results to relative bioavailability (RBA) values measured in vivo. The results indicate that the RBALP measurements are strongly correlated with the in vivo RBA values (r2 = 0.924, p < 0.0001), with an average absolute error of 10% and an average predictive error of 20%. Comparison of results within and between laboratories indicates that the procedure is highly reproducible, with inter-and intra-laboratory coefficients of variation of 4% and 6%, respectively, and within-sample precision of approximately 7%. Based on the results reported here, the RBALP can be effective in providing reliable estimates of lead RBA as predicted by the immature swine model. The method may also be valuable in evaluating site-specific differences in bioaccessibility, assessing remedial technologies intended to reduce lead RBA, providing a screening mechanism for futurein vivo studies, and providing insight into the chemical and physical factors that control lead bioavailability.
Determination of copper, iron and nickel in edible oils using emulsified solutions by ICP-AES

The determination of copper, iron and nickel in edible oils was carried out using emulsion sample preparation followed by analysis by ICP-AES. Response surface methodology was applied in order to find the optimum emulsion and surfactant concentrations. The optimum amount of oil in the emulsion was in the range ca. 2-35% in most of the surfactants studied, except for Triton X-100, which showed a maximum response above 35% oil. The surfactant concentration in the emulsion varied between 0.5 and 9%. Good agreement was found between calibration curves for emulsified aqueous standards solutions and oil-in-water emulsions for most elements studied with Tween 80, ethoxynonylphenol and Triton X-100. The best agreement for all elements was shown when Tween 80 was used. Hence emulsified aqueous standard solutions could be used for the determination of these elements in emulsified edible oil samples using ICP-AES. Recoveries ranged from 90 to 110% for most of the elements studied, with relative standard deviations lower than 8%.
Gas-phase reaction of ozone with trans-2-hexenal, trans-2-hexenyl acetate, ethylvinyl ketone, and 6-methyl-5-hepten-2-one

The gas-phase reaction of ozone with the unsaturated oxygenates trans-2-hexenal, trans-2-hexenyl acetate, ethylvinyl ketone, and 6-methyl-5-hepten-2-one, which are components of biogenic emissions and/or close structural homologues thereof, has been investigated at atmospheric pressure and ambient temperature (286–291 K) and humidity (RH = 55 ± 10%). Reaction rate constants, in units of 10−18 cm3 molecule−1 s−1, are 1.28 ± 0.28 for trans-2-hexenal, 21.8 ± 2.8 for trans-2-hexenyl acetate, and 394 ± 40 for 6-methyl-5-hepten-2-one. Carbonyl product formation yields, measured with sufficient cyclohexane added to scavenge the hydroxyl radical, are 0.53 ± 0.06 for n-butanal and 0.56 ± 0.04 for glyoxal from trans-2-hexenal, 0.47 ± 0.02 for n-butanal and 0.58 ± 0.14 for 1-oxoethyl acetate from trans-2-hexenyl acetate, 0.55 ± 0.07 for formaldehyde and 0.44 ± 0.03 for 2-oxobutanal from ethylvinyl ketone, and 0.28 ± 0.02 for acetone from 6-methyl-5-hepten-2-one. Reaction mechanisms are outlined and the atmospheric persistence of the compounds studied is briefly discussed. © 1996 John Wiley & Sons, Inc.
Liquid Chromatography‐Diode Array and Electrospray High‐Accuracy Mass Spectrometry of Iso‐α‐Acids in DCHA‐Iso Standard and Beer

ABSTRACT J. Inst. Brew. 113(1), 48–54, 2007 Excellent liquid chromatographic (LC) separation of cis / trans stereoisomers of iso- -acids has been achieved with reversed-phase sorbent XTerra MS C18. An isocratic alkaline mobile phase, consisting of a mixture of 5 mmol l –1 ammonium acetate (pH 8)-acetonitrile-methanol, 62:21:17 (v/v/v), was used. In the DCHA-Iso international calibration standard trans -isoposthumu-lone was identified combining photo diode array (PDA) spectra and electrospray high-accuracy mass spectrometric (MS) data. Moreover, the molecular mass of two degradation products re-sulting from the in-solution storage of the DCHA-Iso standard was determined. The presence of trans and cis isomers of iso-posthumulone, isocohumulone, isoadhumulone and iso-n-humu-lone in beer samples was confirmed. The trans isomers of iso- -acids showed characteristic and reproducibly slightly different ultraviolet absorbance spectra with respect to cis isomers. Key words: Beer, DCHA-Iso standard, electrospray, food analy-sis, high-accuracy mass spectrometry, isoadhumulone, isocohu-mulone, iso-n-humulone, isoposthumulone, UV spectra.
Simple Route to Grow High-Quality MgB2 Thin Films by Pyrolysis of Decaborane (B10H14) in Mg Vapor

We report the growth of MgB2 films by thermally decomposing decaborane (B10H14) in Mg vapor. B10H14, solid at ambient temperature and stable in air, is much more convenient to use as a boron source compared to highly explosive diborane (B2H6) which is commonly used in the hybrid physical–chemical vapor deposition of MgB2 films. MgB2 films were grown on c-cut sapphire substrates held at 400–450 °C by supplying vaporized B10H14 into a pocket heater with high Mg vapor pressure. The resultant films were phase-pure, c-axis oriented, and in-plane aligned, and had self-field critical current density of ∼3×107 A/cm2 at 20 K.